FN Thomson Reuters Web of Science™ VR 1.0 PT S AU Garrison, MB Nguyen, DH AF Garrison, Matthew B. Nguyen, Daniel H. BE ElGenk, MS TI Thermal considerations for designing the next lunar lander SO Space Technology and Applications International Forum - STAIF 2007 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE exploration; thermal; lander; lunar AB The Vision for Space Exploration calls for NASA to develop a lunar lander that is capable of delivering humans anywhere on the moon's surface at any time. This presents a significant challenge for thermal engineers, as the lander must be able to survive both the freezing 14-day long lunar night as well as the harsh lunar noon. These problems and potential solutions are presented for each stage of the proposed mission that will return American astronauts to the moon. C1 NASA, Goddard Space Flight Ctr, Thermal Engn Branch, Greenbelt, MD 20771 USA. RP Garrison, MB (reprint author), NASA, Goddard Space Flight Ctr, Thermal Engn Branch, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 35 EP 42 PG 8 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500005 ER PT S AU Farrar, D Douglas, DM Swanson, T Collins, C Darrin, A Osiander, R AF Farrar, Dawnielle Douglas, Donya M. Swanson, Ted Collins, Christine Darrin, Ann Osiander, Robert BE ElGenk, MS TI MEMS shutters for thermal control - Flight validation and lessons learned SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE space technology-5; emerging technology; low-power; micro-satellites; thermal control AB Mechanical thermal louvers are active thermal control devices that have been used to regulate the area of a radiator in response to its temperature. Shutters and louvers were suggested as a means of thermal control using MEMS for nano and pico satellites. JHU/APL, together with NASA/GSFC and Sandia National Laboratory, developed a MEMS shutter design which was flown on NASA/GSFC's Space Technology 5 (ST-5) technology demonstration mission as a variable emittance coating. Fabricated with Sandia's SUMMIT 5 process, six electrostatic comb drives, using Sandia's high performance design, will move an array of shutters, each 150 pm long and 6 mu m wide, to expose either a gold surface (emissivity < 0.1) or the silicon substrate (emissivity < 0.6). To qualify the MEMS louver, several environmental tests were conducted on the fmal flight articles. The device needed to pass various performance tests (i.e. vibration, thermal vacuum, EMI/EMC, and magnetics) to verify its survival. In addition, component-level life cycling tests, performance measurements (both effective IR emissivity and solar absorptivity), and cycling in vacuum (over 1000 times) were conducted. All tests were passed, and ST5 was launched successfully in March 2006. This paper will show the validation results of the flight and discuss lessons learned from MEMS systems in space. C1 [Farrar, Dawnielle; Darrin, Ann; Osiander, Robert] Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. [Douglas, Donya M.; Swanson, Ted; Collins, Christine] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Farrar, D (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM Dawnielle.Farrar@jhuapl.edu RI Darrin, Margaret/H-4305-2011; Osiander, Robert/J-5781-2015 OI Osiander, Robert/0000-0001-9672-5513 FU NASA GSFC Thermal Control Branch [ST-5] FX APL is the principal investigator of the Variable Emittance (MEMS) Electronic Control Unit and the MSA Radiator. The MEMS wafers were fabricated at Sandia National Laboratories. Funding provided by the NASA GSFC Thermal Control Branch and ST-5 Project Team. NR 3 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 73 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500010 ER PT S AU Naumann, RJ Barth, J Marris, JM Adcock, LE Banish, RM Ellis, JM AF Naumann, R. J. Barth, Jim Marris, James M. Adcock, Leonard E. Banish, R. Michael Ellis, Joel M. BE ElGenk, MS TI Optimized design and testing of a graphite-fiber reinforced composite heat pipe radiator with tapered fins SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE space radiator; finned heat pipe; optimization; graphite fiber reinforced composite; GRPC AB An algorithm for optimizing the fin geometry of a heat pipe/fin radiator with tapered fins has been developed and a test article has been fabricated from graphite reinforced fiber composite (GRFC) to test the model. The algorithm determines the width and thickness of the fins in order to provide the maximum heat radiated per elements mass given the linear density of the heat pipe, the thermal conductivity and density of the fin material, the emissivity of the surface, and the operating temperature. In order to take advantage of the new high conductivity of the graphite fibers, the fins must be wide and extremely thin (similar to 1 mm) at the root and taper to a knife-edge. The issues are: 1. Can a radiator/fin of this geometry be fabricated? 2. Will it perform as expected? 3. Can it withstand thermal cycling and extreme cold? 4. Will it survive launch environment? A test article has been fabricated to the specifications required by the optimized model. Thermal tests have been carried out in a vacuum chamber with LN2 walls and the results are presented. The issue of mechanical ability to withstand launch environment awaits further testing. C1 [Naumann, R. J.; Banish, R. Michael; Ellis, Joel M.] Univ Alabama, Ctr Mat Sci, Huntsville, AL 35899 USA. [Adcock, Leonard E.] Univ Alabama, Rotor Craft Syst Engn & Simulat Ctr, Huntsville, AL 35899 USA. [Barth, Jim] ATK Mission Syst Grp, Space Syst & Sensors, San Diego, CA 92121 USA. [Marris, James M.] Marshall Space Flight Ctr, Environm Test Facil, ED26, Huntsville, AL 35812 USA. RP Naumann, RJ (reprint author), Univ Alabama, Ctr Mat Sci, Huntsville, AL 35899 USA. FU Cooperative Agreement [NNM05AA2A]; National Space Science and Technology Center; Twila Schneider; AME Task Coordinator at Marshall; COTR; MSFC FX The authors wish to thank Mary Beth Cook, the Deputy Project Manager, New Projects and Partnerships Development at the Marshall Space Flight Center, who funded this work through Cooperative Agreement NNM05AA2A, National Space Science and Technology Center and to Twila Schneider, AME Task Coordinator at Marshall, who served as the COTR, for their support of this effort. We are especially grateful to Randy Powers and other member of the Environmental Test Facility, ED26 at MSFC for their supporting effort during the thermal vacuum testing. NR 5 TC 0 Z9 1 U1 2 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 81 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500011 ER PT S AU Selvam, RP Hamilton, M Silk, EA AF Selvam, R. Panneer Hamilton, Matthew Silk, Eric A. BE ElGenk, MS TI Spray cooling modeling: Liquid film thickness effect on heat transfer SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE spray cooling; modeling; high heat flux; thick film; thin film ID FLUX; SIMULATION AB Spray cooling is a novel solution for high heat flux applications, whose need is becoming apparent with the advance of high power density electronic systems (lasers, radars, etc). The aim of this investigation is to explore thermal management solutions for space-based systems and the effects of varying gravity on heat transfer. Previous modeling done by Selvam, Lin, and Ponnappan (2006) used a liquid film thickness of approximate to 40 mu m on the heater wall. The two-phase flow modeling is done using the level set method to identify the interface of vapor and liquid as explained in Selvam, Lin, and Ponnappan (2005; 2006). Modifications to the incompressible Navier-Stokes equations for surface tension, viscosity, gravity and phase change are discussed in detail. The equations are solved using finite difference method. The computed heat flux in thick layers is compared with previous thin layer heat flux. The computed liquid and vapor interface and temperature distributions are also visualized for better understanding of the heat removal process. To understand the heat transfer mechanisms in thick liquid layer, droplet impact on a growing vapor bubble is used to study heat transfer in the liquid layer. The thickness has been varied from 100 pin to 200 pin. Also the impact of initial temperature distribution on heat flux is investigated. This will help us to know how to improve the heat transfer in spray cooling. C1 [Selvam, R. Panneer; Hamilton, Matthew] Power Elect Leveling Solut LLC, 700 Res Ctr Blvd, Fayetteville, AR 72701 USA. [Selvam, R. Panneer; Hamilton, Matthew] Univ Arkansas, Bell 4190, Fayetteville, AR 72701 USA. [Silk, Eric A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Selvam, RP (reprint author), Power Elect Leveling Solut LLC, 700 Res Ctr Blvd, Fayetteville, AR 72701 USA. EM rps@uark.edu RI selvam, Rathinam/H-7849-2013 FU NASA Goddard Space Flight Center; SBIR FX This work was performed at the University of Arkansas Computational Mechanics Laboratory. The funding for this work came from the NASA Goddard Space Flight Center, funded through an SBIR grant awarded to Power Electronic Leveling Solutions, L.L.C. NR 15 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 110 EP + PG 3 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500014 ER PT S AU Tarau, C Sarraf, DB Locci, IE Anderson, WG AF Tarau, Calin Sarraf, David B. Locci, Ivan E. Anderson, William G. BE ElGenk, MS TI Intermediate temperature fluids life tests - Theory SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE heat pipe life tests; intermediate temperature heat pipes; halide working fluids; space radiator systems; high temperature electronics cooling AB There are a number of different applications that could use heat pipes or loop heat pipes (LHPs) in the intermediate temperature range of 450 to 750 K, including space nuclear power system radiators, and high temperature electronics cooling. Potential working fluids include organic fluids, elements, and halides, with halides being the least understood, with only a few life tests conducted. Potential envelope materials for halide working fluids include pure aluminum, aluminum alloys, commercially pure (CP) titanium, titanium alloys, and corrosion resistant superalloys. Life tests were conducted with three halides (AlBr3, SbBr3, and TiCl4) and water in three different envelopes: two aluminum alloys (Al-5052, Al-6061) and CP-2 titanium. The AlBr3 attacked the grain boundaries in the aluminum envelopes, and formed TiAl compounds in the titanium. The SbBr3 was incompatible with the only envelope material that it was tested with, Al-6061. TiCl4 and water were both compatible with CP2-titanium. A theoretical model was developed that uses electromotive force differences to predict the compatibility of halide working fluids with envelope materials. This theory predicts that iron, nickel, and molybdenum are good envelope materials, while aluminum and titanium halides are good working fluids. The model is in good agreement with results from previous life tests, as well as the current life tests. C1 [Tarau, Calin; Sarraf, David B.; Anderson, William G.] Adv Cooling Technol Inc, Lancaster, PA 17601 USA. [Locci, Ivan E.] NASA, Gleen Res Ctr, Cleveland, OH 44135 USA. RP Tarau, C (reprint author), Adv Cooling Technol Inc, Lancaster, PA 17601 USA. EM BilLAnderson@1-ACT.com FU NASA Glenn Research Center [NNCO6CA74C] FX Portions of this research was sponsored by NASA Glenn Research Center under Contract NNCO6CA74C. We would like to thank Cheryl Bowman and David Ellis of NASA Glenn Research Center for helpful discussions about the fluids and materials. One the authors (EL) would like to acknowledge the excellent technical assistance of Eric Sockel. John Juhas, Adrienne Veverka and joy Buehler at the NASA Glenn Research Center. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 137 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500017 ER PT S AU Gold, RE McNutt, RL Napolillo, DH Schaefer, ED Tanzman, JR Fiehler, DI Hartka, TJ Mehoke, DS Ostdiek, PH Persons, DF Prockter, LM Vernon, SR AF Gold, Robert E. McNutt, Ralph L., Jr. Napolillo, David H. Schaefer, Edward D. Tanzman, Jennifer R. Fiehler, Douglas I. Hartka, Theodore J. Mehoke, Douglas S. Ostdiek, Paul H. Persons, David F. Prockter, Louise M. Vernon, Steven R. BE ElGenk, MS TI PARIS to Hektor: A concept for a mission to the Jovian Trojan asteroids SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE Asteroids; Jupiter; ion propulsion AB This paper presents an example of a new class of planetary exploration missions that is been enabled by the combination of the three technologies of advanced radioisotope power systems, electric propulsion, and expendable launch vehicles. These PARIS (Planetary Access with Radioisotope Ion-drive System) missions are optimized for rendezvous with outer solar system bodies in shallow gravity wells. They are low-thrust missions that are launched to a high C-3 and use their electric propulsion systems to slow them to enable orbit insertion or landing on the target body. The PARIS spacecraft can be powered by traditional Radioisotope Thermoelectric Generators (RTGs), but win benefit greatly from the improved power-to-mass ratio of Stirling radioisotope generators (SRGs) that results from their high conversion efficiency. These New-Frontiers class missions can carry a significant science payload to the Jovian Trojan asteroids. The Trojans are very primitive bodies located near the Jovian L4 and L5 Lagrange points. The PARIS to Hektor mission can reach the asteroids in less than 5 years, orbit 624 Hektor, the largest of the Jovian Trojans, and go on to orbit at least one other nearby object. There are estimated to be more than 10(5) Jovian Trojans greater than 1 km in diameter. The PARIS to Hektor spacecraft has a candidate payload that includes wide-field and narrow-field cameras, a UV-Vis-IR spectrograph, gamma-ray and neutron spectrometers, and plasma and energetic particle spectrometers. The power system generates about 900 W and the launch mass is slightly less than 1000 kg. The trip time is 5 years if "classic" GPHS RTGs are used for power. Next generation Stirling radioisotope generators (SRGs), with a demonstrated thermal conversion efficiency of > 30% and an estimated specific power of > 8W/kg would reduce the travel time to about,4 years. C1 [Gold, Robert E.; McNutt, Ralph L., Jr.; Napolillo, David H.; Schaefer, Edward D.; Tanzman, Jennifer R.; Hartka, Theodore J.; Mehoke, Douglas S.; Ostdiek, Paul H.; Persons, David F.; Prockter, Louise M.; Vernon, Steven R.] Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. [Fiehler, Douglas I.] NASA, Gleen Res Ctr, ASRC Aerosp, Cleveland, OH 44135 USA. RP Gold, RE (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM robert.gold@jhuapl.edu RI McNutt, Ralph/E-8006-2010 OI McNutt, Ralph/0000-0002-4722-9166 NR 10 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 217 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500025 ER PT S AU Clough, JA Starkey, RP Lewis, MJ Lavelle, TM AF Clough, Joshua A. Starkey, Ryan P. Lewis, Mark J. Lavelle, Thomas M. BE ElGenk, MS TI Tie tube heat transfer modeling for bimodal nuclear thermal rockets SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE bimodal nuclear thermal rocket; reactor modeling; tie tubes; heat transfer; conduction ID PROPULSION; MISSION; SYSTEM AB Bimodal nuclear thermal rocket systems have been shown to reduce the weight and cost of space vehicles to Mars and beyond by utilizing the reactor for power generation in the relatively long duration between bums in an interplanetary trajectory. No information, however, is available regarding engine and reactor-level operation of such bimodal systems. The purpose of this project is to generate engine and reactor models with sufficient fidelity and flexibility to accurately study the component-level effects of operating a propulsion-designed reactor at power generation levels. Previous development of a I-D reactor and tie tube model found that ignoring heat generation inside of the tie tube leads to under-prediction of the temperature change and over-prediction of pressure change across the tie tube. This paper will present the development and results of a tie tube model that has been extended to account for heat generation, specifically in the moderator layer. This model is based on a I-D distribution of power in the fuel elements and tie tubes, as a precursor to an eventual neutron-driven reactor model. C1 [Clough, Joshua A.; Starkey, Ryan P.; Lewis, Mark J.] Univ Maryland, Dept Aerosp Engn, College Pk, MD 20742 USA. [Lavelle, Thomas M.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Clough, JA (reprint author), Univ Maryland, Dept Aerosp Engn, College Pk, MD 20742 USA. EM cloughja@umd.edu NR 10 TC 0 Z9 0 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 281 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500033 ER PT S AU Krause, DL Kalluri, S Bowman, RR AF Krause, David L. Kalluri, Sreeramesh Bowman, Randy R. BE ElGenk, MS TI Structural benchmark testing for Stirling convertor heater heads SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE Stirling heater head creep deformation life cascade test Inconel 718 MarM 247 superalloy precipitate grain AB The National Aeronautics and Space Administration (NASA) has identified high efficiency Stirling technology for potential use on long duration Space Science missions such as Mars rovers, deep space missions, and lunar applications. For the long life times required, a structurally significant design limit for the Stirling convertor heater head is creep deformation induced even under relatively low stress levels at high material temperatures. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and much creep data is available for the proposed Inconel-718 (IN-718) and MarM-247 nickel-based superalloy materials of construction. However, very little experimental creep information is available that directly applies to the atypical thin walls, the specific microstructures, and the low stress levels. In addition, the geometry and loading conditions apply multiaxial stress states on the heater head components, far from the conditions of uniaxial testing. For these reasons, experimental benchmark testing is underway to aid in accurately assessing the durability of Stirling heater heads. The investigation supplements uniaxial creep testing with pneumatic testing of heater head test articles at elevated temperatures and with stress levels ranging from one to seven times design stresses. This paper presents experimental methods, results, post-test microstiuctural analyses, and conclusions for both accelerated and non-accelerated tests. The Stirling projects use the results to calibrate deterministic and probabilistic analytical creep models of the heater heads to predict their life times. C1 [Krause, David L.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Kalluri, Sreeramesh] NASA, Ohio Aerosp, Brookpark, OH 44135 USA. [Bowman, Randy R.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Krause, DL (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM krause@nasa.gov FU The Science Mission Directorate at NASA Headquarters FX The Science Mission Directorate at NASA Headquarters provided funding to complete the work described herein. The authors thank the Glenn technical leadership and management, especially Dick Shaltens, Jeff Schreiber, Lanny Thieme, David J. Anderson, and John Sankovic, for their inspiring support and assistance. The authors also thank Drs. Gary Halford, Vinod Arya, and Ashwin Shah for their beneficial technical collaboration, and Frank Bremenour, Ralph Pawlik, and John Zima for their able laboratory support. NR 9 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 297 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500035 ER PT S AU Schreiber, JG Thieme, LG AF Schreiber, Jeffrey G. Thieme, Lanny G. BE ElGenk, MS TI Final results for the GRC supporting technology development project for the 110-watt Stirling radioisotope generator (SRG110) SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE Stirling; radioisotope; space power; reliability; organics; magnets; EMI/EMC; structural dynamics AB From 1999-2006, the NASA Glenn Research Center (GRC) supported the development of a high-efficiency, nominal 110-We Stirling Radioisotope Generator (SRG110) for potential use on NASA missions, including deep space missions, Mars rovers, and lunar applications. Lockheed Martin (LM) was the system integrator for the SRG110, under contract to the Department of Energy (DOE). Infinia Corporation (fonnerly Stirling Technology Company) developed the Stirling convertor, first as a contractor to DOE and then under subcontract to LM. The SRG110 development has been redirected, and recent program changes have been made to significantly increase the specific power of the generator. System development of an Advanced Stirling Radioisotope Generator (ASRG) has now begun, using a lightweight, advanced convertor from Sunpower, Inc. This paper summarizes the results of the supporting technology effort that GRC completed for the SRG110. GRC tasks included convertor extended-duration testing in air and thermal vacuum environments, heater head life assessment materials studies, permanent magnet aging characterization, linear alternator evaluations, structural dynamics testing, electromagnetic interference (EMI) and electromagnetic compatibility (EMC) characterization, organic materials evaluations, reliability studies, and development of an end-to-end system dynamic model. Related efforts are now continuing in many of these areas to support ASRG development. C1 [Schreiber, Jeffrey G.; Thieme, Lanny G.] NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Schreiber, JG (reprint author), NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. EM Jeffrey.G.Schreiber@nasa.gov NR 23 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 325 EP + PG 3 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500038 ER PT S AU Abelson, RD Clark, KB AF Abelson, Robert D. Clark, Karla B. BE ElGenk, MS TI The europa explorer - A fresh look at exploring Europa with an RIPS-powered spacecraft SO Space Technology and Applications International Forum - STAIF 2007 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE Europa; Europa Explorer; ARTG; ASRG; MMRTG; GPHS-RTG; RPS AB An orbital mission to Europa has been identified as a high priority by the science community for several years. The difficulty of this type of mission, primarily due to the propulsive requirements and Jupiter's trapped radiation, led to many studies which investigated various approaches to meeting the science goals. A flagship-class Europa orbiting mission, which performs a multi-year study of the Jupiter system, can now be envisioned relying on existing technologies, having significantly more capability and returning considerably more science data than previous conventional propulsion mission concepts. This study resulted in several mission concept designs ranging significantly in capability and commensurate cost. The concept discussed herein returns three year's worth of Cassini data (similar to 3 Tbit) in approximately 90 days around Europa. During its 3 month (90 day) Europa Prime Mission, the spacecraft would orbit Europa over 1000 times and provide three orders of magnitude more close (< 5000 km altitude) Europa observing time than Galileo. A., science group was formed to verify that the science objectives and goals were being adequately met by the mission design concept. The mission concept consists of a single orbiter which would traverse to Jupiter by means of a gravity assist trajectory and reach Jupiter similar to 6 years after launch, followed by an similar to 1 1/2 year tour of the Galilean satellites before entering Europa orbit. The Europa Prime Mission would be 90 days with high expectations of being operational for upwards of a year. Due to the significant power requirements, tight pointing requirements and intense radiation levels, this mission would be enabled by radioisotope power systems (RPSs). RPSs would be used for all onboard electrical power, with the excess heat used for thermal control of the spacecraft's subsystems. While the mission baselines the use of eight Multi-mission Radioisotope Thermoelectric Generators (MMRTGs), trade studies were also performed to assess the benefits of using the General Purpose Heat Source - Radioisotope Thermoelectric Generator (GPHS-RTG), an Advanced Stirling Radioisotope Generator (ASRG), and an Advanced Radioisotope Thermoelectric Generator (ARTG). The results of the study show that a comprehensive Europa orbit mission is feasible using existing RTG technology, and that significant savings in mass and plutonium-238 usage can be realized using advanced RPS technologies expected to come on line as early as similar to 2016. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Abelson, RD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 355 EP 363 PG 9 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500041 ER PT S AU Elliott, JO Reh, K Spilker, T AF Elliott, John O. Reh, Kim Spilker, Tom BE ElGenk, MS TI Titan exploration using a radioisotopically-heated Montgolfiere balloon SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE titan; aerocapture; radioisotope power system; Montgolfiere AB This paper describes results of a recent Titan exploration mission study; one which includes an aerial vehicle in the form of a hot air balloon, or montgolfiere. Unlike terrestrial montgolfieres which require burning fuel, the dual use of MMRTGs to provide a continuous source of heat as well as electrical power would give the balloon an inherent ability to float for a very long time in the atmosphere of Titan. It would ride with the easterly winds at a cruising altitude of about 10,000 km, occasionally changing altitude to take advantage of possible reverse wind directions and even descending to the surface to physically sample sites of interest. Seasonal and tidal north-south winds would allow the mission to explore different latitudes, which Cassini data have shown to be amazingly diverse in geologic nature. Communication from the aerial vehicle would be relayed through an accompanying orbiter spacecraft, as well as transmitted directly to Earth, providing the potential for data return from Titan's surface equivalent to that provided by many comparable orbiter missions at much closer destinations. C1 [Elliott, John O.; Reh, Kim; Spilker, Tom] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RP Elliott, JO (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jelliott@jpl.nasa.gov NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 372 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500043 ER PT S AU Clark, PE Calle, CI Curtis, SA Keller, JF Minetto, F Mantovani, JG AF Clark, P. E. Calle, C. I. Curtis, S. A. Keller, J. F. Minetto, F. Mantovani, J. G. BE ElGenk, MS TI Electrostatic dust control on planetary surfaces SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE dust control; electrostatic; mechanical; lunar surface; exploration ID LUNAR DUST; SPACECRAFT; WAKE AB Successful operation for exploration of planetary regoliths will depend on the capability to keep surfaces free of dust which could compromise performance and to collect dust for characterization. Such study is essential in order to resolve issues in dealing with regolith fines identified during the Apollo missions where dust behaved like abrasive Velcro before returning to the Moon. During Moon landings, locally-induced stirring of the regolith caused dust to be suspended long enough to come into contact with conducting surfaces. Lunar fines, because of their electrostatic charging, were difficult to collect and sparsely sampled: bag seals were broken, samples contaminated and lost. Our objectives here are to describe a multi-faceted electrostatically-based approach and methodology for addressing this issue, as well as to present our preliminary results which confirm the view that the successful strategy will deal with dust dynamics resulting from interaction between mechanical and electrostatic forces. Our device concept combines electron or ion beams, acting as a plasma dust sweeper to control the flow of dust by systematic scanning of the surface with an electrostatically controlled potential. A plate of the opposite potential used to induce dust migration in the presence of an electrical field. Our goal is a compact device of < 5 kg mass and using < 5 watts of power to be operational in < 5 years with heritage from ionic sweepers for active spacecraft potential control (e.g., on POLAR). Rovers, human or robotic, wheeled, legged, or tetrahedral, could be fitted with devices that could harness the removal of dust for sampling as part of the extended exploration process on extensive areas of exposed impact-generated regolith, on Mercury, Mars, asteroids or outer solar system satellites, as well as the Moon. C1 [Clark, P. E.] Catholic Univ Amer, Washington, DC 20064 USA. [Clark, P. E.; Curtis, S. A.; Keller, J. F.; Minetto, F.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Calle, C. I.; Mantovani, J. G.] NASA, KSC, Kennedy Space Ctr, FL 32899 USA. RP Clark, PE (reprint author), Catholic Univ Amer, Washington, DC 20064 USA. EM pamela.clark@gsfc.nasa.gov RI Keller, John/I-5097-2013 FU NASA/KSC [695]; NASA/GSFC DDF [544]; GSFC [588] FX We would like to acknowledge the important discussion pertaining to this work we have had with our colleague William Farrell, David Carrier, and Otto Berg. We thank NASA/KSC, NASA/GSFC DDF, GSFC Codes 695, 544, and 588 for their support. NR 30 TC 1 Z9 1 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 400 EP + PG 3 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500046 ER PT S AU Pauken, M Emis, N Watkins, B AF Pauken, Mike Emis, Nick Watkins, Brenda BE ElGenk, MS TI Thermal energy storage technology developments SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE spacecraft thermal control; heat transfer; phase change materials; thermal energy storage AB This paper describes recent technology developments in thermal energy storage devices for use on spacecraft for thermal control of electronic components requiring thermal stability. A thermal energy storage module has been designed, built and tested using lithium nitrate as the melt material and carbon foam as the conductive filler. For this unit the observed melt temperature was around 30 degrees C. The supercooling property of lithium nitrate was reduced by adding zinc nitrate as a catalyst. The hydrophobic nature of the carbon foam was overcome by adding a surfactant to the lithium nitrate. The resulting energy storage capacity of the prototype module during the melt was 40 W-hr/kg. There was very good thermal conductivity through the module resulting in very low temperature gradients even at high power levels. C1 [Pauken, Mike; Emis, Nick; Watkins, Brenda] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RP Pauken, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Michael.T.Pauken@jpl.nasa.gov NR 3 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 412 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500048 ER PT S AU Miller, WO Wang, M Shih, W Ramirez, R Beach, D Youchison, D Lenard, R Liguori, J Liguori, E AF Miller, W. O. Wang, Mike Shih, Wei Ramirez, Rogelio Beach, Duane Youchison, Dennis Lenard, Roger Liguori, Justin Liguori, Ed BE ElGenk, MS TI An ultra-lightweight, high performance carbon-carbon space radiators SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE carbon-carbon material; carbonizing carbon-carbon to metal; titanium heat pipe; metal to carbon foam brazing; space radiator; carbon-carbon radiator sandwich panels AB Propulsion systems for deep space exploration that rely on nuclear energy require innovative advancements in radiator technology, both materials and construction technique, to meet the demands associated with high rejection temperatures. A five fold reduction in radiator specific mass is achievable and will be needed to meet the demanding challenge of space exploration. Our development of a carbon-carbon (C-C) based radiator design unaffected by long term exposure to high temperature and radiation has wide ranging application, for both small and large power conversion systems. Our results stem from a NASA SBIR program focused on demonstrating thermal performance in a high temperature carbon-carbon (C-C) radiator configured with titanium water-heat pipes, using approximately 500 K water for the working fluid. However, joining strategy and material choices employed are appropriate for very high temperature alkali fluids. Distinct design advantages of carbon-carbon material are its low density, unlimited life, and ability to tailor its physical properties through fiber selection, fiber orientation, and special processing. We will report on our experience in joining of titanium to carbonized materials through direct carbonization and brazing. Results of thermal tests at Sandia National Laboratories on a I kW thermal radiator will be presented, along with construction progress and testing of a 2.6 m(2) sandwich radiator for NASA Glenn. C1 [Miller, W. O.; Wang, Mike; Shih, Wei; Ramirez, Rogelio] Allcomp Corp, City Of Industry, CA 91746 USA. [Beach, Duane] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Youchison, Dennis; Lenard, Roger] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Liguori, Justin; Liguori, Ed] Scarrott Metallurgical Corp, Los Angeles, CA 90045 USA. RP Miller, WO (reprint author), Allcomp Corp, City Of Industry, CA 91746 USA. EM bill.miller@allcomp.net OI Youchison, Dennis/0000-0002-7366-1710 FU NASA Glenn Research Center [NNC04CA03C] FX This program was sponsored by NASA Glenn Research Center under Contract NNC04CA03C. Duane Beach technically monitored our Phase I and Phase II program efforts, in addition to providing valuable guidance.; Dennis Youchison and Roger Lenard provided much needed technical and facility resources during the test and evaluation phase of our program, for which we are extremely grateful. Our appreciation is also extended to their staff, J.M. McDonald, T.J. Lutz, F.J. Bauer, and K.P. Troncosa who were responsible for test assembly, testing, and data monitoring and recording.; Technical issues associated with brazing dissimilar materials were very effectively dealt with through the expertise of Ed and Justin Liguor NR 3 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 421 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500049 ER PT S AU Pearson, JB Stewart, ET Reid, RS AF Pearson, J. Boise Stewart, Eric T. Reid, Robert S. BE ElGenk, MS TI Experimental evaluation of the thermal performance of a water shield for a surface power reactor SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE fission; reactor; structural; shield; material ID DESIGN AB Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as-compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 degrees C. The CFD model with 1/6-g predicts a maximum water temperature of 88 degrees C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield. C1 [Pearson, J. Boise; Stewart, Eric T.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Reid, Robert S.] Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Pearson, JB (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM j.boise.pearson@nasa.gov FU NASA through the Prometheus Program in support of the Vision for Space Exploration FX The authors wish to recognize the contributions of the following members of the Marshall Space Flight Center EFFTF team: Kenny Webster, Roger Harper, Gene Fant, Jason Berry, and Stan MacDonald. This work was funded by NASA through the Prometheus Program in support of the Vision for Space Exploration. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 430 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500050 ER PT S AU Amiri, BW Kapernick, RJ Sims, BT Simpson, SP AF Amiri, Benjamin W. Kapernick, Richard J. Sims, Bryan T. Simpson, Steven P. BE ElGenk, MS TI A new capability for nuclear thermal propulsion design SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE Nuclear Thermal Propulsion; NTP; core nuclear; mechanical and thermal design AB This paper describes a new capability for Nuclear Thermal Propulsion (NTP) design that has been developed, and presents the results of some analyses performed with this design tool. The purpose of the tool is to design to specified mission and material limits, while maximizing system thrust to weight. The head end of the design tool utilizes the ROCket Engine Transient Simulation (ROCETS) code to generate a system design and system design requirements as inputs to the core analysis. ROCETS is a modular system level code which has been used extensively in the liquid rocket engine industry for many years. The core design tool performs high-fidelity reactor core nuclear and thermal-hydraulic; design analysis. At the heart of this process are two codes TMSS-NTP and NTPgen, which together greatly automate the analysis, providing the capability to rapidly produce designs that meet all specified requirements while minimizing mass. A PERL based command script, called CORE DESIGNER controls the execution of these two codes, and checks for convergence throughout the process. TMSS-NTP is executed first, to produce a suite of core designs that meet the specified reactor core mechanical, thermal-hydraulic and structural requirements. The suite of designs consists of a set of core layouts and, for each core layout specific designs that span a range of core fuel volumes. NTPgen generates MCNPX models for each of the core designs from TMSS-NTP. Iterative analyses are performed in NTPgen until a reactor design (fuel volume) is identified for each core layout that meets cold and hot operation reactivity requirements and that is zoned to meet a radial core power distribution requirement. C1 [Amiri, Benjamin W.; Kapernick, Richard J.; Sims, Bryan T.] Los Alamos Natl Lab, Nucl Syst Design Grp, Los Alamos, NM 87545 USA. [Amiri, Benjamin W.] Univ Florida, Nucl & Radiol Engn Dept, Gainesville, FL 32611 USA. [Sims, Bryan T.] Purdue Univ, Sch Nucl Engn, W Lafayette, IN 47907 USA. [Simpson, Steven P.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Amiri, BW (reprint author), Los Alamos Natl Lab, Nucl Syst Design Grp, Los Alamos, NM 87545 USA. EM bwamiri@lanl.gov FU NASA Marshall Space Flight Center FX The development of the design process described in this paper was funded by NASA Marshall Space Flight Center. The authors wish to give thanks to Dr. Karl Nelson and Mr. Wayne Bordelon at NASA Marshall Space Flight Center for their support in this effort. NR 10 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 438 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500051 ER PT S AU Bragg-Sitton, SM Dickens, R Dixon, D Kapernick, R Adams, M Davis, J AF Bragg-Sitton, Shannon M. Dickens, Ricky Dixon, David Kapernick, Richard Adams, Mike Davis, Joe BE ElGenk, MS TI Development of high fidelity, fuel-like thermal simulators for non-nuclear testing SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE non-nuclear testing; thermal simulators; electrical heaters ID DESIGN AB Non-nuclear testing can be a valuable tool in the development of a space nuclear power or propulsion system. In a non-nuclear test bed, electric heaters are used to simulate the heat from nuclear fuel. Work at the NASA Marshall Space Flight Center seeks to develop high fidelity thermal simulators that not only match the static power profile that would be observed in an operating, fueled nuclear reactor, but also match the dynamic fuel pin performance during feasible transients. Comparison between the fuel pins and thermal simulators is made at the outer fuel clad surface, which corresponds to the outer sheath surface in the thermal simulator. The thermal simulators that are currently being developed are designed to meet the geometric and power requirements of a proposed surface power reactor design, accommodate testing of various axial power profiles, and incorporate imbedded instrumentation. Static and dynamic fuel pin performances for a proposed reactor design have been determined using SINDA/FLUINT thermal analysis software, and initial comparison has been made between the expected nuclear performance and the performance of conceptual thermal simulator designs. Through a series of iterative analysis, a conceptual high fidelity design will be developed, followed by engineering design, fabrication, and testing to validate the overall design process. Although the resulting thermal simulator will be designed for a specific reactor concept, establishing this rigorous design process will assist in streamlining the thermal simulator development for other reactor concepts. This paper presents the current status of high fidelity thermal simulator design relative to a SNAP derivative reactor design that could be applied for Lunar surface power. C1 [Bragg-Sitton, Shannon M.; Dickens, Ricky; Adams, Mike; Davis, Joe] NASA, Marshall Space Flight Ctr, Nucl Syst Branch ER24, Huntsville, AL 35812 USA. [Dixon, David; Kapernick, Richard] Los Alamos Natl Lab, Decis Applicat Div, Los Alamos, NM 87545 USA. [Dixon, David] North Carolina State Univ, Raleigh, NC USA. RP Bragg-Sitton, SM (reprint author), NASA, Marshall Space Flight Ctr, Nucl Syst Branch ER24, Huntsville, AL 35812 USA. EM Shannon.M.Bragg-Sitton@nasa.gov NR 11 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 605 EP + PG 3 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500066 ER PT S AU Determan, WR Otting, W Frye, P Abelson, R Ewell, R Miyake, B Synder, J AF Determan, William R. Otting, William Frye, Patrick Abelson, Robert Ewell, Richard Miyake, Bob Synder, Jeff BE ElGenk, MS TI Multi-watt small radioisotope thermoelectric generator conceptual design study SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE Radioisotope Thermoelectric Generator; small RTG; multi-watt RTG AB A need has been identified for a small, light-weight, reliable power source using a radioisotope heat source, to power the next generation of NASA's small surface rovers and exploration probes. Unit performance, development costs, and technical risk are key criteria to be used to select the best design approach. Because safety can be a major program cost and schedule driver, RTG designs should utilize the DOE radioisotope safety program's data base to the maximum extent possible. Other aspects important to the conceptual design include: 1) a multi-mission capable design for atmospheric and vacuum environments, 2) a module size based on one GPHS Step 2 module, 3) use of flight proven thermoelectric converter technologies, 4) a long service lifetime of up to 14 years, 5) maximize unit specific power consistent with all other requirements, and 6) be ready by 2013. Another critical aspect of the design is the thermal integration of the RTG with the rover or probe's heat rejection subsystem and the descent vehicle's heat rejection subsystem. This paper describes two multi-watt RTG design concepts and their integration with a MER-class rover. C1 [Determan, William R.; Otting, William; Frye, Patrick] Hamilton Sundstrand Rocketdyne, Space Land & Sea, 6633 Camoga Ave, Canoga Pk, CA 91309 USA. [Abelson, Robert; Ewell, Richard; Miyake, Bob; Synder, Jeff] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Determan, WR (reprint author), Hamilton Sundstrand Rocketdyne, Space Land & Sea, 6633 Camoga Ave, Canoga Pk, CA 91309 USA. EM william.determan@pwr.utc.com FU Department of Energy Office of Space and Defense Power Systems; DOE [DE-FG07-06ID14758-01.] FX The authors are pleased to acknowledge the Department of Energy Office of Space and Defense Power Systems for sponsoring this study; DOE Contract Number DE-FG07-06ID14758-01. NR 4 TC 1 Z9 1 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 624 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500068 ER PT S AU Balint, TS AF Balint, Tibor S. BE ElGenk, MS TI NASA'S RPS design reference mission set for Solar System Exploration SO Space Technology and Applications International Forum - STAIF 2007 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE RPS; Design Reference Mission Set; Solar System Exploration; NASA AB NASA's 2006 Solar System Exploration (SSE) Strategic Roadmap identified a set of proposed large Flagship, medium New Frontiers and small Discovery class missions, addressing key exploration objectives. These objectives respond to the recommendations by the National Research Council (NRC), reported in the SSE Decadal Survey. The SSE Roadmap is down-selected from an over-subscribed set of missions, called the SSE Design Reference Mission (DRM) set. Missions in the Flagship and New Frontiers classes can consider Radioisotope Power Systems (RPSs), while small Discovery class missions are not permitted to use them, due to cost constraints. In line with the SSE DRM set and the SSE Roadmap missions, the RPS DRM set represents a set of missions, which can be enabled or enhanced by RPS technologies. At present NASA has proposed the development of two new types of RPSs. These are the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), with static power conversion; and the Stirling Radioisotope Generator (SRG), with dynamic conversion. Advanced RPSs, under consideration for possible development aim to increase specific power levels. In effect, this would either increase electric power generation for the same amount of fuel, or reduce fuel requirements for the same power output compared to the proposed MMRTG or SRG. Operating environments could also influence the design, such that an RPS on the proposed Titan Explorer would use smaller fins to minimize heat rejection in the extreme cold environment; while the Venus Mobile Explorer long-lived in-situ mission would require the development of a new RPS, in order to tolerate the extreme hot environment and to simultaneously provide active cooling to the payload and other electric components. This paper discusses NASA's SSE RPS DRM set, in line with the SSE DRM set. It gives a qualitative assessment regarding the impact of various RPS technology and configuration options on potential mission architectures, which could support NASA's RPS technology development planning, and provide an understanding of fuel need trades over the next three decades. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Balint, TS (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 631 EP 639 PG 9 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500069 ER PT S AU Gabb, TP Gayda, J Garg, A AF Gabb, Timothy P. Gayda, John Garg, Anita BE ElGenk, MS TI Creep property characterization of potential Brayton cycle impeller and duct materials SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE superalloy; creep AB Cast superalloys have potential applications in space as impellers within closed-loop Brayton cycle nuclear power generation systems. Likewise wrought superalloys are good candidates for ducts and heat exchangers transporting the inert working gas in a Brayton-based power plant. Two cast superalloys, Mar-M247LC and IN792, and a NASA GRC powder metallurgy superalloy, LSHR, have been screened to compare their respective capabilities for impeller applications. Mar-M247LC has been selected for additional long term evaluations. Initial tests in helium indicate this inert environment may debit long term creep resistance of this alloy. Several wrought superalloys including Hastelloy (R) X, Inconel (R) 617, Inconel (R) 740, Nimonic (R) 263, Incoloy (R) MA956, and Haynes 230 are also being screened to compare their capabilities for duct applications. Haynes 230 has been selected for additional long term evaluations. Initial tests in helium are just underway for this alloy. These proposed applications would require sufficient strength and creep resistance for long term service at temperatures up to 1200 K, with service times to 100,000 h or more. Therefore, long term microstructural stability is also being screened. C1 [Gabb, Timothy P.; Gayda, John] NASA, Glenn Res Ctr, Mat & Struct Div, Cleveland, OH 44135 USA. [Garg, Anita] Univ Toledo, Cleveland, OH 44135 USA. RP Gabb, TP (reprint author), NASA, Glenn Res Ctr, Mat & Struct Div, Cleveland, OH 44135 USA. EM tim.gabb@grc.nasa.gov FU Prometheus Power and Propulsion Program under NASA's Exploration Systems Mission Directorate FX This research was supported through the Prometheus Power and Propulsion Program under NASAs Exploration Systems Mission Directorate. NR 19 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 640 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500070 ER PT S AU Bowman, CL Jaworske, DA Stanford, MK Persinger, JA Khorsandi, B Blue, TE AF Bowman, Cheryl L. Jaworske, Donald A. Stanford, Malcolm K. Persinger, Justin A. Khorsandi, Behrooz Blue, Thomas E. BE ElGenk, MS TI Post irradiation evaluation of thermal control coatings and solid lubricants to support fission surface power systems SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE heat rejection systems; thermal control surfaces AB The development of a nuclear power system for space missions, such as the Jupiter Icy Moons Orbiter or a lunar outpost, requires substantially more compact reactor design than conventional terrestrial systems. In order to minimize shielding requirements and hence system weight, the radiation tolerance of component materials within the power conversion and heat rejection systems must be defined. Two classes of coatings, thermal control paints and solid lubricants, were identified as material systems for which limited radiation hardness information was available. Screening studies were designed to explore candidate coatings under a predominately fast neutron spectrum. The Ohio State Research Reactor Facility staff performed irradiation in a well characterized, mixed energy spectrum and performed post irradiation analysis of representative coatings for thermal control and solid lubricant applications. Thermal control paints were evaluated for 1 MeV equivalent fluences from 10(13) to 10(15) n/cm(2). No optical degradation was noted although some adhesive degradation was found at higher fluence levels. Solid lubricant coatings were evaluated for 1 MeV equivalent fluences from 10(15) to 10(16) n/cm(2) with coating adhesion and flexibility used for post irradiation evaluation screening. The exposures studied did not lead to obvious property degradation indicating the coatings would have survived the radiation environment for the previously proposed Jupiter mission. The results are also applicable to space power development programs such as fission surface power for future lunar and Mars missions. C1 [Bowman, Cheryl L.; Jaworske, Donald A.; Stanford, Malcolm K.] NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. [Persinger, Justin A.; Khorsandi, Behrooz; Blue, Thomas E.] Ohio State Univ, Nucl Engr Program, Dept Mech Engr, Columbus, OH 43210 USA. RP Bowman, CL (reprint author), NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. EM Cheryl.L.Bowman@nasa.gov FU Victor Lukaszewicz at NASA GRC; David Hawn; Jeremy Chenkovich and Viji Krishnan at OSU; Prometheus Power and Propulsion Program under NASA's Exploration Systems Mission Directorate FX The authors appreciate research support provided by Victor Lukaszewicz at NASA GRC and David Hawn, Jeremy Chenkovich and Viji Krishnan at OSU. This research was supported through the Prometheus Power and Propulsion Program under NASAs Exploration Systems Mission Directorate. Any opinions expressed are those of the authors and do not necessarily reflect the views of NASA, the Department of Energy, or the Prometheus Program NR 11 TC 0 Z9 0 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 652 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500071 ER PT S AU Locci, IE Nesbitt, JA Ritzert, FJ Bowman, CL AF Locci, Ivan E. Nesbitt, James A. Ritzert, Frank J. Bowman, Cheryl L. BE ElGenk, MS TI High temperature stability of dissimilar metal joints in fission surface power systems SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE superalloys; refractory alloys; joining; diffusion bond; microstructure; interlayers; interface AB Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying material requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples. C1 [Locci, Ivan E.] Univ Toledo, NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. [Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.] NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Locci, IE (reprint author), Univ Toledo, NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. EM ivan.e.locci@nasa.gov FU Prometheus Power and Propulsion Program under NASA's Exploration Systems Mission Directorate FX This research was supported through the Prometheus Power and Propulsion Program under NASAs Exploration Systems Mission Directorate. NR 4 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 660 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500072 ER PT S AU Howard, SA Bruckner, RJ DellaCorte, C Radil, KC AF Howard, Sainuel A. Bruckner, Robert J. DellaCorte, Christopher Radil, Kevin C. BE ElGenk, MS TI Gas foil bearing technology advancements for Closed Brayton Cycle turbines SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE nuclear power; Brayton; turbine; foil gas bearings ID DESIGN AB Closed Brayton Cycle (CBC) turbine systems are under consideration for future space electric power generation. CBC turbines convert thermal energy from a nuclear reactor, or other heat source, to electrical power using a closed-loop cycle. The operating fluid in the closed-loop is commonly a high pressure inert gas mixture that cannot tolerate contamination. One source of potential contamination in a system such as this is the lubricant used in the turbomachine bearings. Gas Foil Bearings (GFB) represent a bearing technology that eliminates the possibility of contamination by using the working fluid as the lubricant. Thus, foil bearings are well suited to application in space power CBC turbine systems. NASA Glenn Research Center is actively researching GIB technology for use in these CBC power turbines. A power loss model has been developed, and the effects of very high ambient pressure, start-up torque, and misalignment, have been observed and are reported here. C1 [Howard, Sainuel A.; Bruckner, Robert J.; DellaCorte, Christopher] NASA, Glenn Res Ctr, MS 23-2,21000 Brookpk Rd, Cleveland, OH 44135 USA. [Radil, Kevin C.] NASA, Glenn Res Ctr, US Army Vehicle Propuls Directorate, Cleveland, OH 44135 USA. RP Howard, SA (reprint author), NASA, Glenn Res Ctr, MS 23-2,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM howard@nasa.gov NR 20 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 668 EP + PG 3 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500073 ER PT S AU Birchenough, A Hervol, D AF Birchenough, Arthur Hervol, David BE ElGenk, MS TI Operational results from a high power alternator test bed SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE energy conversion; high-current and high-voltage technology; conductors and resistors; inductors and coils; wiring AB The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, OH was used to simulate the operating conditions and evaluate the performance of the ATU and its interaction with various LPSF components in accordance with the current Fission Surface Power System (FSPS) requirements. The testing was carried out at the breadboard development level. These results successfully demonstrated excellent ATU power bus characteristics and rectified user load power quality during steady state and transient conditions. Information gained from this work could be used to assist the design and primary power quality considerations for a possible future FSPS. This paper describes the LPSF components and some preliminary test results. C1 [Birchenough, Arthur] NASA, Glenn Res Ctr, Power & Elect Propuls Div, Adv Elect Syst Branch, Cleveland, OH 44135 USA. [Hervol, David] Analex Corp, NASA, Glenn Engn & Sci Support Org, Mech Syst Branch, Cleveland, OH USA. RP Birchenough, A (reprint author), NASA, Glenn Res Ctr, Power & Elect Propuls Div, Adv Elect Syst Branch, Cleveland, OH 44135 USA. EM David.S.Hervol@nasa.gov NR 3 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 692 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500075 ER PT S AU Lewis, R Micheels, K Dankewicz, C AF Lewis, Ruthan Micheels, Kurt Dankewicz, Cathy BE ElGenk, MS TI The making of a lunar outpost- Exploring a future case study SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE lunar outpost; lunar base; lunar habitation; lunar architecture; space architecture; inflatable AB Buildup and development of a lunar outpost / base will be an incremental and alternated process of crew, logistics, hardware, and science payload deliveries. To better plan the resources and technological objectives for each increment, one may examine the operational and technological requirements for a "midterm" phase and project backwards to derive and strategize requirements and resources for each stage of the development. This comprehensive characterization of the midterm phase will ultimately provide the waypoint by which later development phases can be more effectively planned. A unique and critical engineering and architectural view of a midterm waypoint and the roadmap to achieve the goals and capabilities at that milestone was generated. Data to derive the process and midterm outpost design was acquired during a recent comprehensive National Aeronautics and Space Administration (NASA) research project. Current and soon to be state-of-the-art, viable, proven technologies to support an effective and resourceful outpost design including rigidizable, inflatable structures, hybridized in-situ and imported materials utilization, and environmentally-responsive structures considering thermal, radiation, topographical, low-gravity, crew and transport mobility, habitability, and logistics aspects were investigated and applied. Adjacency analyses were performed to optimize the arrangement of spaces. Additionally, an inventive, internal, organizational architectural system that maps and coordinates lunar and Earth contingency planning configurations and activities, and assists fabrication and layout processes and techniques was derived. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lewis, R (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM ruthan.lewis@nasa.gov NR 7 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 703 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500076 ER PT S AU McLemore, CA Kennedy, JP Rose, FA Evans, BW AF McLemore, Carole A. Kennedy, James P. Rose, Frederick A. Evans, Brian W. BE ElGenk, MS TI Exploration challenges: Transferring ground repair techniques to space flight application SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE technology development; repair technologies; maintainability; design for maintainability; repairability; Vision for Space Exploration. AB Fulfilling NASA's Vision for Space Exploration will demand an extended presence in space at distances from our home planet that exceed our current experience in space logistics and maintenance. The ability to perform repairs in lieu of the customary Orbital Replacement Unit (ORU) process where a faulty part is replaced will be elevated from contingency to routine to sustain operations. The use and cost effectiveness of field repairs for ground based operations in industry and the military have advanced with the development of technology in new materials, new repair techniques and new equipment. The unique enviromnents, accessibility constraints and Extra Vehicular Activity (EVA) issues of space operations will require extensive assessment and evolution of these technologies to provide an equivalent and expected level of assurance to mission success. Challenges include the necessity of changes in design philosophy and policy, extremes in thermal cycling, disruptive forces (such as static charge and wind entrainment) on developed methods for control of materials, dramatically increased volatility of chemicals for cleaning and other compounds due to extremely low pressures, the limits imposed on dexterity and maneuverability by current EVA equipment and practices, and the necessity of unique verification methodology. This paper describes these challenges in and discusses the effects on the established ground techniques for repair. The paper also describes the leading repair methodology candidates and their beneficial attributes for resolving these issues with the evolution of technology. C1 NASA, George C Marshall Space Flight Ctr, Explorat Syst Dev Off, VP33, Huntsville, AL 35812 USA. RP McLemore, CA (reprint author), NASA, George C Marshall Space Flight Ctr, Explorat Syst Dev Off, VP33, Huntsville, AL 35812 USA. EM carole.a.mclemore@nasa.gov FU Marshall Space Flight Center under the Microgravity Science; Applications Department (MSAD) Systems Development and Operations Support (SDOS) [NAS8-02060] FX Portions of this work were performed in support of the Marshall Space Flight Center under the Microgravity Science and Applications Department (MSAD) Systems Development and Operations Support (SDOS) Contract (No. NAS8-02060). NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 719 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500078 ER PT S AU Cooper, KG Good, JE Gilley, SD AF Cooper, Kenneth G. Good, James E. Gilley, Scott D. BE ElGenk, MS TI Layered metals fabrication technology development for support of lunar exploration at NASA/MSFC SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE layered fabrication; solid freeform fabrication; rapid manufacturing; additive fabrication AB NASA's human exploration initiative poses great opportunity and risk for missions to the Moon and beyond. In support of these missions, engineers and scientists at the Marshall Space Flight Center are developing technologies for ground-based and in-situ fabrication capabilities utilizing provisioned and locally-refined materials. Development efforts are pushing state-of-the art fabrication technologies to support habitat structure development tools and mechanical part fabrication, as well as repair and replacement of ground support and space mission hardware such as life support items, launch vehicle components and crew exercise equipment. This paper addresses current fabrication technologies relative to meeting targeted capabilities, near term advancement goals, and process certification of fabrication methods. C1 NASA, George C Marshall Space Flight Ctr, Technol & Capabil Dev Projects Off, SY10, Huntsville, AL 35812 USA. RP Cooper, KG (reprint author), NASA, George C Marshall Space Flight Ctr, Technol & Capabil Dev Projects Off, SY10, Huntsville, AL 35812 USA. EM Kenneth.G.Cooper@nasa.gov NR 5 TC 1 Z9 2 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 728 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500079 ER PT S AU Mueller, J Goldberg, H Alkalai, L AF Mueller, Juergen Goldberg, Hannah Alkalai, Leon BE ElGenk, MS TI Micro-inspector spacecraft testbed: Breadboard subsystem demonstrations SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE micro-inspector; microspacecraft; space exploration missions AB Micro-inspector is a 5-kg inspection platform designed to operate autonomously following operator up-linked command sequences around a host spacecraft to perform safety inspections, anomaly inspections, or imaging of large in-space assemblies as envisioned for future NASA exploration missions. Similarly, such an inspection platform may be adapted to military space missions. Micro-inspector relies on solar power and using celestial sensors for navigation, giving the system large flexibility in the missions and applications it may serve, including those beyond Earth orbit. Micro-Inspector, through its small size and low weight poses minimal design impacts to the host. Its small size and weight also affords micro-inspector to be disposable, allowing multiple inspectors to be used by a single host for different inspection routines or as emergency back-up. Its low-pressure butane propulsion system combines safety and compactness through liquid propellant storage with an adequate performance of up to 30 m/s for inspection maneuvers around the host. Micro-inspector, since power limited through a body mounted solar array, thus avoiding the complexities of deployable structures, relies on many advanced, ultra-low power micro-technologies, such as a novel microvalve by VACCO Industries in its propulsion system, electrochromic surface modulating heat transfer from the spacecraft using no moving parts, low power dual processor and FPGA-based reconfigurable and SEU mitigating avionics, a low power RF telecom link based on the Mars Micro Transceiver, and micro attitude control sensors, such as commercial micro IMUs and a JPL developed micro sun sensor. Host safety is a key concern, and multiple safety features are employed by micro-inspector to prevent any accidental impact onto the host. Among these is an active, laser-based range-finding collision avoidance system, which constantly monitors the distance to the host and via the micro-inspector's control system maintains a safe distance. Micro-Inspector design, through funding from the NASA Explorations Systems Mission Directorate, has significantly advanced over the past year and is currently at PDR level and beyond. Special emphasis was placed on retiring risk in various subsystem areas through the use of advanced technologies. To this end, a micro-inspector test bed was set up to critically assess the readiness of component technologies and subsystems. Breadboard subsystem demonstrations and system integration were performed to place future design efforts on a solid basis. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mueller, J (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM juergen.mueller@jpl.nasa.gov FU NASA Exploration Systems Research & Technology's (ESR&T) Advanced Space Operations (ASO) Technology Maturation Program FX The effort described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. We gratefully acknowledge support for this project through the NASA Exploration Systems Research & Technologys (ESR&T) Advanced Space Operations (ASO) Technology Maturation Program, managed by Chris Moore and Nantel Suzuki. The authors would like to acknowledge the entire Micro-Inspectorproject team at JPL including Brad Swenson, David Bame, Tony Paris, Gary Bolotin, Mohammad Ashtijou, Yutao He, Ian Ferguson, George Wells, Hemali Vyas, Sal DiStefano, Vatche Vorperian, Jim Alexander, Sohrab Mobasser, Curtis Padgett, and Christian Liebe, and our collaborating partners specifically Dan Harrison and Dennis Wells at Johnson Space Center, Scott MacGillivray and Al Tsuda at the Boeing Company, Joe Cardin and Mike Khodorovsky at VACCO Industries, and Prasanna Chandrasekher at Ashwin-Ushas. We would also like to gratefully acknowledge the support by our students, serving under the Caltech Summer Undergraduate Research Fellowship (SURF) program at JPL, namely Ashley Smetana ofthe University of Michigan, Jason Kephardt and Christopher Schantz of Caltech, and Jesse Way of Montana State University. Their dedication and motivation is helping micro-inspector to move through challenging fiscal times. Finally, we are greatly indebted to those at JPL who contributed to the success of the pre-cursor project, the Low Cost Adjunct Microspacecraft (LCAM) testbed activity, and especially would like to thank David Collins for hispioneering efforts and vision, which have advanced microspacecraft designs significantly over the many years of his career dedicated to this task, and which live on in micro-inspector even after his retirement from JPL. NR 12 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 742 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500081 ER PT S AU Woytach, JM Linne, DL Chambers, JA Willis, BP Carek, GA AF Woytach, Jeffrey M. Linne, Diane L. Chambers, Jeffrey A. Willis, Brian P. Carek, Gerald A. BE ElGenk, MS TI Where space comes down to earth: Test facilities for exploration systems SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE plum brook; space power facility; spacecraft propulsion research facility; cryogenic testing complex; cryogenic propellant tank facility; cryogenic components laboratory; exploration; moon; regolith AB The NASA Glenn Research Center's (GRC's) Plum Brook Station has a complement of unique, highly capable facilities that can test space flight hardware ranging from development testing at the component subsystem and system levels up to environmental qualification of very large spacecraft and extraterrestrial surface systems. The facilities can simulate the conditions of free space or the surfaces of the Moon or Mars, including atmospheric pressure and content, temperature and day/night cycles. This paper presents information on the facilities at the Plum Brook Station as they apply to the development of space systems that support the Vision for Space Exploration, and cites specific examples of testing to illustrate those capabilities. C1 NASA, Glenn Res Ctr, Plum Brook Stn, 6100 Columbus Ave, Sandusky, OH 44870 USA. RP Woytach, JM (reprint author), NASA, Glenn Res Ctr, Plum Brook Stn, 6100 Columbus Ave, Sandusky, OH 44870 USA. EM Jeffrey.M.Woytach@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 769 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500083 ER PT S AU Sherwood, B AF Sherwood, Brent BE ElGenk, MS TI What will we actually do on the Moon? SO Space Technology and Applications International Forum - STAIF 2007 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE lunar exploration; lunar operations; Moon base; public engagement; settlement; Mars; port authority; astrophysics; robotics; human space flight AB Descriptions are provided for eleven specific, representative lunar activity scenarios selected from among hundreds that arose in 2006 from the NASA-sponsored development of a "global lunar strategy." The scenarios are: pave for dust control; establish a colony of continuously active robots; kitchen science, designer biology; tend the machinery; search for pieces of ancient Earth; build simple observatories that open new wavelength regimes; establish a virtual real-time network to enable public engagement institute a public-private lunar development corporation; rehearse planetary protection protocols for Mars; and expand life and intelligence beyond Earth through settlement of the Moon. Evocative scenarios such as these are proposed as a communications tool to help win public understanding and support of the Vision for Space Exploration. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sherwood, B (reprint author), CALTECH, Jet Prop Lab, M-S 301-355, Pasadena, CA 91109 USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 814 EP 822 PG 9 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500088 ER PT S AU Captain, J Lueck, D Kolody, M Whitten, M AF Captain, Janine Lueck, Dale Kolody, Mark Whitten, Mary BE ElGenk, MS TI Development of an integrated RVC-LWRD system for RESOLVE SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE ISRU; RESOLVE; hydrogen; lunar surface AB Resource investigation in the lunar poles is important to the potential impact of in-situ resource utilization (ISRU). The Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE) project aims to develop a payload that will investigate the permanently shadowed areas of the lunar poles and demonstrate ISRU technology. As a part of the RESOLVE project, the regolith volatile characterization (RVC) subsystem will examine the release of volatiles from sample cores. The volatile sample will be introduced into the lunar water resource demonstration (LWRD) subsystem where the released hydrogen and water will be selectively captured. The water will be condensed to form a droplet and electrolyzed to produce hydrogen and oxygen. This process will demonstrate small scale ISRU techniques. This paper will present the challenges, characteristics, and development of the RVC and LWRD. The experiments performed to evaluate adsorption methods will be discussed. Based on these experiments, it has been decided that a salt hydride will be used to capture water vapor and a metal hydride will be used to capture hydrogen from the sample. C1 NASA, Appl Technol Directorate, KT D, Kennedy Space Ctr, FL 32899 USA. RP Captain, J (reprint author), NASA, Appl Technol Directorate, KT D, Kennedy Space Ctr, FL 32899 USA. EM Janine.E.Captain@nasa.gov NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 823 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500089 ER PT S AU Ethridge, E Kaukler, W AF Ethridge, Edwin Kaukler, William BE ElGenk, MS TI Microwave extraction of water from lunar regolith simulant SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE lunar water; lunar regolith simulant; microwave processing; lunar experiments AB Nearly a decade ago the DOD Clementine lunar orbital mission obtained data indicating that the permanently shaded regions at the lunar poles may have permanently frozen water in the lunar soil or 'permafrost'. Currently a Lunar Lander Exploration Program is expected to land at the lunar pole to determine if water is present. The detection of water from the permafrost is an important goal for NASA. Extraction of water from lunar permafrost would be a valuable In-Situ Resource for Utilization (ISRU) in human life support and as a fuel. The use of microwave processing could permit the extraction of water without the need to dig, drill, or excavate the lunar surface. Microwave heating of regolith is potentially faster and more efficient than any other heating methods due to the very low thermal conductivity of the lunar regolith. Also, microwaves can penetrate into the soil permitting water removal from deep below the lunar surface. A cryogenic vacuum test facility was developed for evaluating the use of microwave heating and water extraction from a lunar regolith simulant. Water was collected in a cryogenic cold trap even with soil temperature well below 0 degrees C. The results of microwave extraction of water experiments will be presented. C1 NASA, George C Marshall Space Flight Ctr, EM40, Huntsville, AL 35812 USA. RP Ethridge, E (reprint author), NASA, George C Marshall Space Flight Ctr, EM40, Huntsville, AL 35812 USA. EM Ed.Ethrige@nasa.gov; William.Kaukler@msfc.nasa.gov OI Kaukler, William/0000-0002-7758-269X FU In-Space Fabrication and Repair group at the Marshall Space Flight Center FX The authors would like to thank Carole McLemore VP33 in the In-Situ Resource Utilization and In-Space Fabrication and Repair group at the Marshall Space Flight Center for support and funding of this research project. NR 5 TC 1 Z9 1 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 830 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500090 ER PT S AU Zacny, K Glaser, D Bartlett, P Davis, K Gorevan, S AF Zacny, Kris Glaser, David Bartlett, Paul Davis, Kiel Gorevan, Stephan BE ElGenk, MS TI Drilling results in ice-bound simulated lunar regolith SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE drilling; In Situ Resource Utilization; lunar simulant AB Reaching the cold traps at the lunar poles and directly sensing the subsurface regolith is a primary goal of lunar exploration, especially as a means of prospecting for future In Situ Resource Utilization (ISRU) efforts. The Construction and Resource Utilization Explorer project (CRUX) addressed technology development associated with a modular, drilling-based payload to achieve this goal. As part of the development of a lunar drill capable of reaching a depth of two meters, a preliminary drilling study was performed using custom designed drill bits and augers in simulated ice-bound lunar regolith. Lunar regolith is known to be very abrasive, but the mechanical properties and "drillability" of the purported ice-bound material in the lunar cold traps is unknown. Preliminary drilling experiments were performed in the frozen samples, to determine the effectiveness of the drilling hardware and to point the way towards optimized drilling strategies. Additionally, a preliminary experiment was performed to demonstrate the utility of converting drilling energy per volume (Specific Energy) to the Unconfined Compressive Strength (UCS) of the simulated frozen regolith. The results showed that the drilling hardware was capable of penetrating into the samples and that this was most effectively done at slow rotational speeds (< 60 RPM) and with a low axial force (weight-on-bit). The results also indicate that the specific energy of drilling is correlated to the UCS of the material tested. C1 [Zacny, Kris; Glaser, David] NASA, Honeybee Robot, Moffett Field, CA 94035 USA. [Bartlett, Paul; Davis, Kiel; Gorevan, Stephan] Honeybee Robot, New York, NY 10001 USA. RP Zacny, K (reprint author), NASA, Honeybee Robot, Moffett Field, CA 94035 USA. EM zacny@honeybeerobotics.com FU National Aeronautical and Space Administration FX This work was supported by the National Aeronautical and Space Administration. We would also like to thank Dave Cole of Cold Regions Research and Engineering Laboratory for performing the UCS tests. NR 13 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 838 EP + PG 3 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500091 ER PT S AU Cardiff, EH Pomeroy, BR Banks, IS Benz, A AF Cardiff, Eric H. Pomeroy, Brian R. Banks, Ian S. Benz, Alexis BE ElGenk, MS TI Vacuum pyrolysis and related ISRU techniques SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE vacuum pyrolysis; In Situ Resource Utilization AB A number of ISRU-related techniques have been developed at NASA Goddard Space Flight Center. The focus of the team has been on development of the vacuum pyrolysis technique for the production of oxygen from the lunar regolith. However, a number of related techniques have also been developed, including solar concentration, solar heating of regolith, resistive heating of regolith, sintering, regolith boiling, and instrumentation development. An initial prototype system was developed to vaporize regolith simulants using a similar to 1m(2) Fresnel lens. This system was successfully used to vaporize quantities of similar to 1g, and both mass spectroscopy of the gasses produced and Scanning Electron Microscopy (SEM) of the slag were done to show that oxygen was produced. Subsequent tests have demonstrated the use of a larger system with a 3.8m diameter reflective mirror to vaporize the regolith. These results and modeling of the vacuum pyrolysis reaction have indicated that the vaporization of the oxides in the regolith will occur at lower temperature for stronger vacuums. The chemical modeling was validated by testing of a resistive heating system that vaporized quantities of similar to 10g of MLS-1A. This system was also used to demonstrate the sintering of regolith simulants at reduced temperatures in high vacuum. This reduction in the required temperature prompted the development of a small-scale resistive heating system for application as a scientific instrument as well as a proof-of principle experiment for oxygen production. C1 [Cardiff, Eric H.; Pomeroy, Brian R.; Banks, Ian S.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Benz, Alexis] Univ Michigan, Ann Arbor, MI 48104 USA. RP Cardiff, EH (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Eric.H.Cardiff@nasa.gov NR 6 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 846 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500092 ER PT S AU Iacomini, C MacCallum, T Morin, T Straub-Lopez, K Paul, H AF Iacomini, Christine MacCallum, Taber Morin, Tom Straub-Lopez, Kathrine Paul, Heather BE ElGenk, MS TI Martian liquid CO2 and metabolic heat regenerated temperature swing adsorption for portable life support systems SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE carbon dioxide; portable life support system; Mars; carbon dioxide removal; carbon dioxide condensation AB Two of the fundamental problems facing the development of a Portable Life Support System (PLSS) for use on Mars, are (i) heat rejection (because traditional technologies use sublimation of water, which wastes a scarce resource and contaminates the premises), and (ii) rejection of CO2 in an environment with a ppCO(2) of 0.4-0.9 kPa. This paper presents a conceptual system for CO2 collection, compression, and cooling to produce sub-critical (liquid) CO2. A first order estimate of the system mass and energy to condense and store liquid CO2 outside at Mars ambient temperature at 600 kPa is discussed. No serious technical hurdles were identified and it is likely that better overall performance would be achieved if the system were part of an integrated ISRU strategy rather than a standalone system. Patent-pending Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology for CO2 removal from a PLSS vent loop, where the Martian liquid CO2 is used as the heat sink is developed to utilize the readily available liquid CO2. This paper will describe the technology and present data in support of its design. C1 [Iacomini, Christine; MacCallum, Taber; Morin, Tom; Straub-Lopez, Kathrine] Paragon Space Dev Corp, Tucson, AZ USA. [Paul, Heather] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Iacomini, C (reprint author), Paragon Space Dev Corp, Tucson, AZ USA. EM ciacomini@paragonsdc.com FU NASA Johnson Space Center for MTSA technology development under NASA [NNJ06HA98C] FX The authors would like to acknowledge that a portion of this work was performed for The Charles Stark Draper Laboratory, Inc. in support of Draper / MIT Innovative Architectures for Human Lunar Exploration, Option 1 NASA Concept Exploration & Refinement Concept Area 1 and 2. The authors would also like to acknowledge recent funding by NASA Johnson Space Center for MTSA technology development under NASA contract NNJ06HA98C. NR 11 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 863 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500094 ER PT S AU Curreri, PA AF Curreri, Peter A. BE ElGenk, MS TI A minimized technological approach towards human self sufficiency off Earth SO Space Technology and Applications International Forum - STAIF 2007 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE space resource utilization; space settlement; space habitats AB Since the early 1970's it has been known that it is technically feasible to build large habitats in space where many people could live, more or less, independently off Earth. These large habitats would require decades of Apollo level expenditures to build. The objective of this paper is to begin the study of the minimum technological system that will enable the historic shift from the state where all of humanity is dependent on Earth to the state where an independent human community can exist off Earth. It is suggested that such a system is more on the order of a homestead than a city. A minimum technical system is described that could support one human reproductive unit (family) in free space or on a planetary or lunar surface. The system consists of life support, materials extraction, mobility, and power production. Once the technology is developed for the single unit, many could be deployed. They could reproduce themselves at an exponential rate using space resources and energy. One would imagine cooperation of these units to build any combination of towns, cities and nations in space to extend human life beyond Earth. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Curreri, PA (reprint author), NASA, George C Marshall Space Flight Ctr, Mail Code EM30, Huntsville, AL 35812 USA. NR 9 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 904 EP 910 PG 7 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500099 ER PT S AU Hegde, U Balasubramaniam, R Gokoglu, S AF Hegde, U. Balasubramaniam, R. Gokoglu, S. BE ElGenk, MS TI Development of a reactor model for chemical conversion of lunar regolith SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE hydrogen reduction; ilmenite; lunar regolith; shrinking core ID OXYGEN AB Lunar regolith will be used for a variety of purposes such as oxygen and propellant production and manufacture of various materials. The design and development of chemical conversion reactors for processing lunar regolith will require an understanding of the coupling among the chemical, mass and energy transport processes occurring at the length and time scales of the overall reactor with those occurring at the corresponding scales of the regolith particles. To this end, a coupled transport model is developed using, as an example, the reduction of ilmenite-containing regolith by a continuous flow of hydrogen in a flow-through reactor. The ilmenite conversion occurs on the surface and within the regolith particles. As the ilmenite reduction proceeds, the hydrogen in the reactor is consumed, and this, in turn, affects the conversion rate of the ilmenite in the particles. Several important quantities are identified as a result of the analysis. Reactor scale parameters include the void fraction (i.e., the fraction of the reactor volume not occupied by the regolith particles) and the residence time of hydrogen in the reactor. Particle scale quantities include the time for hydrogen to diffuse into the pores of the regolith particles and the chemical reaction time. The paper investigates the relationships between these quantities and their impact on the regolith conversion. Application of the model to various chemical reactor types, such as fluidized-bed, packed-bed, and rotary-bed configurations, are discussed. C1 [Hegde, U.; Balasubramaniam, R.] Natl Ctr Space Explorat Res, Cleveland, OH 44135 USA. [Gokoglu, S.] NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Hegde, U (reprint author), Natl Ctr Space Explorat Res, Cleveland, OH 44135 USA. EM uday.hegde@grc.nasa.gov FU NASA [NCC3-975]; National Center for Space Exploration Research FX U. Hegde and R. Balasubramaniam were supported under NASA Cooperative Agreement NCC3-975 with the National Center for Space Exploration Research. The authors greatly appreciate the encouragement and insights offered by K. Sacksteder and D. Linne of NASA Glenn Research Center, and useful discussions with E. Santiago-Maldonado of NASA Kennedy Space Center during the course of this work. NR 11 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 941 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500104 ER PT S AU Captain, J Trigwell, S Arens, E Biris, A Captain, J Quinn, J Calle, C AF Captain, James Trigwell, Steve Arens, Ellen Biris, Alex Captain, Janine Quinn, Jacqueline Calle, Carlos BE ElGenk, MS TI Tribocharging lunar simulant in vacuum for electrostatic beneficiation SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE triboelectrification; beneficiation; lunar simulant AB Electrostatic beneficiation of lunar regolith has potential application for separating minerals for material processing on the moon. This paper describes the use of tribocharging lunar simulant prior to mineral grain separation. The lunar simulant JSC-1 was sieved into five size fractions: < 25 mu m, 25-50 mu m, 50-75 mu m, 75-100 mu m, > 100 mu m for characterization, however only the 50-75 mu m fraction was passed through aluminum, copper and polytetrafluoroethylene (PTFE) inclined plane chargers. The amount of charge acquired by the simulant is dependant upon the difference in the work function of the charging material and the mineral grain composition of the simulant itself Various charge-to-mass ratios (Q/M) for the different tribocharging materials were obtained for JSC-1 in vacuum as well as in air. XPS, SEM and Raman spectroscopy were used to evaluate the JSC-1 simulant before and after beneficiation. Results indicate notable changes in mineral composition between pre- and post-beneficiation samples after only a single pass through the aluminum inclined plane charger. C1 [Captain, James] Univ Cent Florida, Mail Stop ASRC-15, Kennedy Space Ctr, FL 32899 USA. [Trigwell, Steve] ASRC Aerosp, Kennedy Space Ctr, FL 32899 USA. [Arens, Ellen; Captain, Janine; Quinn, Jacqueline; Calle, Carlos] NASA, Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. [Biris, Alex] Univ Arkansas, Little Rock, AR 72204 USA. RP Captain, J (reprint author), Univ Cent Florida, Mail Stop ASRC-15, Kennedy Space Ctr, FL 32899 USA. EM James.Captain-1@ksc.nasa.gov FU NASA Kennedy Space Center Spaceport Engineering and Technology Directorate for Center Director Discretionary FX The authors would like to thank the NASA Kennedy Space Center Spaceport Engineering and Technology Directorate for Center Director Discretionary Funding for this research. NR 11 TC 4 Z9 4 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 951 EP + PG 3 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500105 ER PT S AU Rickman, D Hoelzer, H Carpenter, P Sibille, L Howard, R Owens, C AF Rickman, Doug Hoelzer, Hans Carpenter, Paul Sibille, Laurent Howard, Rick Owens, Charles BE ElGenk, MS TI A quantitative method for evaluating regolith simulants SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2007 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2007) CY FEB 11-15, 2007 CL Albuquerque, NM SP Boeing Co, Idaho Natl Lab, Lockheed Martin, Los Alamos Natl Lab, Oak Ridge Natl Lab, Northrop Grumman Space Technol, Sandia Natl Lab, US DOE, Off Sci, Amer Astronaut Soc, AIAA, Amer Inst Chem Engineers, ASME, NASA Natl Space Grant Coll & Fellowship Program, Profess Aerospace Contract Assoc, Inst Space & Nucl Power Studies DE moon; regolith; simulant; quantitative; evaluation AB The surface of rocky planets, moons and some other astronomical bodies have significant amounts of broken geologic materials. In the absence of more specific, applicable terminology, such material is generically termed regolith. Even on relatively simple bodies, like the Moon, the nature of the regolith is fairly complex. For mission development a regolith needs to be simulated; and many have been created for the Moon and Mars. But there is no generally accepted method to express the quality of a simulant. This paper proposes a method for ascertaining the quality of a simulant through the use of Figures-of-Merit. In support of NASA's exploration mission this method has been implemented. MSFC has creating a suite of simulants whose compositions cover the samples returned by the Apollo missions. These are termed Standard Lunar Regolith Simulant (SLRS) materials. The approach is adaptable, extensible and evolutionary. It is considered highly applicable to other regoliths of interest. C1 [Rickman, Doug] NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. [Hoelzer, Hans; Howard, Rick; Owens, Charles] Teledyne Brown Engn Inc, Huntsville, AL 35807 USA. [Carpenter, Paul] NASA, George C Marshall Space Flight Ctr, BAE Syst Analyt & Ordnance Soluti, Huntsville, AL 35812 USA. [Sibille, Laurent] NASA, ASRC Aerosp Corp, Kennedy Space Ctr, FL 32899 USA. RP Rickman, D (reprint author), NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. EM doug.rickman@nasa.gov OI Rickman, Doug/0000-0003-3409-2882 NR 14 TC 1 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0386-4 J9 AIP CONF PROC PY 2007 VL 880 BP 957 EP + PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Physics, Multidisciplinary SC Engineering; Physics GA BFX19 UT WOS:000245240500106 ER PT J AU Vassiliadis, D AF Vassiliadis, Dimitris BA Bothmer, V Daglis, IA BF Bothmer, V Daglis, IA TI Forecasting space weather SO SPACE WEATHER - PHYSICS AND EFFECTS SE Springer Praxis Books LA English DT Article; Book Chapter ID INTERPLANETARY MAGNETIC-FIELD; SOLAR-WIND DATA; NEURAL-NETWORKS; GEOMAGNETIC STORMS; ELECTRIC POTENTIALS; IMPULSE-RESPONSE; SUBSTORM EVENTS; MHD SIMULATION; MODEL; MAGNETOSPHERE AB Forecasting space weather events presents the ultimate challenge to a space physics model. Not only should physical constraints be satisfied, but also practical issues such as timeliness, accuracy and reliability must be adequately addressed. Modern space weather forecasters and users rely on a great variety of space environment forecast systems, ranging from simple non-linear regressions and ending with fairly complex information-based (empirical), physical and hybrid models. Over the last two decades, model-based predictions of space environments have become increasingly sophisticated. Especially since the early 1990s when real-time data began to be available online, time-dependent inputs, and later data assimilation and related techniques such as Kalman filtering, have significantly improved prediction accuracy. Model verification is an important step in evaluating a space weather model's spectrum of forecast capabilities. Case studies are used to illustrate the above concepts. The chapter concludes with a summary of recent developments and future prospects. C1 NASA, Goddard Space Flight Ctr, ST, Greenbelt, MD 20771 USA. RP Vassiliadis, D (reprint author), NASA, Goddard Space Flight Ctr, ST, Bldg 21,Room 265B,Mailstop 612-2, Greenbelt, MD 20771 USA. EM vassi@electra.gsfc.nasa.gov NR 71 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 978-3-540-34578-7 J9 SPRINGER-PRAX BOOKS PY 2007 BP 403 EP + DI 10.1007/978-3-540-34578-7_14 D2 10.1007/978-3-540-34578-7 PG 29 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BLQ83 UT WOS:000270820300015 ER PT B AU Pulkkinen, A AF Pulkkinen, A. BE Lilensten, J TI Spatiotemporal characteristics of the ground electromagnetic field fluctuations in the auroral region and implications on the predictability of geomagnetically induced currents SO Space Weather: Research Towards Applications In Europe SE ASTROPHYSICS AND SPACE SCIENCE LIBRARY LA English DT Proceedings Paper CT 2nd European Space Weather Week CY NOV 14-19, 2005 CL Noordwijk, NETHERLANDS SP European Space Agcy ID GEOELECTROMAGNETIC DISTURBANCES; PREDICTIONS; QUEBEC C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pulkkinen, A (reprint author), NASA, Goddard Space Flight Ctr, Code 6122, Greenbelt, MD 20771 USA. NR 35 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 978-1-4020-5445-7 J9 ASTROPHYS SPACE SC L PY 2007 VL 344 BP 299 EP 310 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGB42 UT WOS:000245916100026 ER PT B AU Scargle, JD AF Scargle, J. D. BE Babu, GJ Feigelson, ED TI Discussion on "Multiscale Analysis of Photon-Limited Astronomical Images" by R. Willett SO STATISTICAL CHALLENGES IN MODERN ASTRONOMY IV SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 4th Statistical Challenges in Modern Astronomy Conference CY JUN 12-15, 2006 CL Penn State Univ, University Pk, PA HO Penn State Univ C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Scargle, JD (reprint author), NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-240-2 J9 ASTR SOC P PY 2007 VL 371 BP 265 EP 267 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields; Statistics & Probability SC Astronomy & Astrophysics; Physics; Mathematics GA BHB12 UT WOS:000252032000025 ER PT B AU Scargle, JD AF Scargle, J. D. BE Babu, GJ Feigelson, ED TI Discussion on "Detecting Periodicities in Astronomical Point Processes" by P. Bickel, B. Kleijn and J. Rice SO STATISTICAL CHALLENGES IN MODERN ASTRONOMY IV SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 4th Statistical Challenges in Modern Astronomy Conference CY JUN 12-15, 2006 CL Penn State Univ, University Pk, PA HO Penn State Univ C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Scargle, JD (reprint author), NASA, Ames Res Ctr, Div Space Sci, Moffett Field, Moffett Field, CA 94035 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-58381-240-2 J9 ASTR SOC P PY 2007 VL 371 BP 321 EP 323 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields; Statistics & Probability SC Astronomy & Astrophysics; Physics; Mathematics GA BHB12 UT WOS:000252032000031 ER PT S AU Dwek, E Arendt, RG AF Dwek, Eli Arendt, Richard G. BE Immler, S Weiler, K McCray, R TI Dust-gas interaction in SNR 1987A SO SUPERNOVA 1987A: 20 YEARS AFTER: SUPERNOVAE AND GAMMA-RAY BURSTERS SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on Supernova 1987A - 20 Years After CY FEB 19-23, 2007 CL Aspen, CO SP Natl Sci Fdn, NASA Goddard Space Flight Ctr, Swift Sci Ctr, XMM Newton Guest Observ Cac, Spitzer Sci Ctr, Chandra X Ray Ctr, Naval Res Lab, Univ Colorado DE supernovae; SN 1987A; supernova remnants; atomic; molecular; and chemical and grain processes; infrared emission; X-ray emission ID SUPERNOVA-REMNANTS; INFRARED-EMISSION; SN 1987A; SN-1987A; RING AB Multiwavelength observations of SNR 1987A show that its morphology is rapidly changing at X-ray, radio, and optical wavelengths as the blast wave from the explosion expands into the circumstellar equatorial ring. Infrared emission arises from the interaction of dust grains with the hot X-ray emitting gas. We show that the IR emission provides important complementary information on the interaction of the SN blast wave with the circumstellar equatorial ring that cannot be obtained at any other wavelength. C1 [Dwek, Eli] NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. [Arendt, Richard G.] NASA, Goddard Space Flight Ctr, CRESST UMBC, Greenbelt, MD 20771 USA. RP Dwek, E (reprint author), NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. EM eli.dwek@nasa.gov FU HST [GO-9114]; Supernova INtensive Survey; NASA [OSS LTSA-2003-0065]; Spitzer Cycle 3 [30067] FX E.D. thanks Dick McCray, Stefan Immler, and Kurt W. Weiler for organizing this stimulating conference in the wonderful surrounding of Aspen, CO, in celebration of the 20th birthday of SN 1987A. This work is based in part on observ ations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Lab oratory, California Institute of Technology, under a contract with NASA. E.D. acknowledges partial support from HST grant GO-9114 for the Supernova INtensive Survey (SInS: Robert Kirshner,PI), and by NASA OSS LTSA-2003-0065. The work of R.G.A. was supported by a grant awarded to Spitzer Cycle 3 proposal ID 30067 NR 10 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0448-9 J9 AIP CONF PROC PY 2007 VL 937 BP 58 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGX54 UT WOS:000251154500007 ER PT S AU Danziger, IJ Bouchet, P DeBuizer, JM Dwek, E Arendt, R AF Danziger, I. J. Bouchet, P. DeBuizer, J. M. Dwek, E. Arendt, R. BE Immler, S Weiler, K McCray, R TI IR imaging of SN1987A SO SUPERNOVA 1987A: 20 YEARS AFTER: SUPERNOVAE AND GAMMA-RAY BURSTERS SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on Supernova 1987A - 20 Years After CY FEB 19-23, 2007 CL Aspen, CO SP Natl Sci Fdn, NASA Goddard Space Flight Ctr, Swift Sci Ctr, XMM Newton Guest Observ Cac, Spitzer Sci Ctr, Chandra X Ray Ctr, Naval Res Lab, Univ Colorado DE infrared; imaging; dust; light curves; interaction AB We present IR imaging observations obtained at various phases in the evolution of SN1987A. They have been obtained with ground-based telescopes in Chile. Some of the early and late ones have not been shown before. Particular emphasis is placed on the recently resolved mid-IR images showing dust in the inner ring being heated by the interaction with the ejecta. Some of its properties are elaborated as well as the importance of such observations now and in the future. Attention is also drawn to the IR emission from the central ejecta and its behaviour. Temporal variations are highlighted. C1 [Danziger, I. J.] Osserv Astron Trieste, INAF, I-34131 Trieste, Italy. [Bouchet, P.] GEPI Observat Paris, Serv Astrophys, DAPNIA, Gif Sur Yvette, France. [DeBuizer, J. M.] Southern Operat Ctr, Gemini Observ, AURA Inc, Laseren, Chile. [Dwek, E.] NASA Goddard Space Flight Ctr, Observat Cosmol Lab Code 665, Greenbelt, MD USA. [Arendt, R.] NASA Goddard Space Flight Ctr, Sci Syst & Appl Inc Code 665, Greenbelt, MD USA. RP Danziger, IJ (reprint author), Osserv Astron Trieste, INAF, I-34131 Trieste, Italy. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0448-9 J9 AIP CONF PROC PY 2007 VL 937 BP 66 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGX54 UT WOS:000251154500008 ER PT S AU Polomski, E Woodward, CE Gehrz, RD Wooden, DH Sugerman, BEK AF Polomski, Elisha Woodward, C. E. Gehrz, R. D. Wooden, D. H. Sugerman, B. E. K. BE Immler, S Weiler, K McCray, R TI Multi-epoch Spitzer spectroscopy of SN 1987A SO SUPERNOVA 1987A: 20 YEARS AFTER: SUPERNOVAE AND GAMMA-RAY BURSTERS SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on Supernova 1987A - 20 Years After CY FEB 19-23, 2007 CL Aspen, CO SP Natl Sci Fdn, NASA Goddard Space Flight Ctr, Swift Sci Ctr, XMM Newton Guest Observ Cac, Spitzer Sci Ctr, Chandra X Ray Ctr, Naval Res Lab, Univ Colorado DE infrared; supernova; spectroscopy; dust ID SN 1987A; PHOTOMETRY AB We present multi-epoch Spitzer spectra of the well known supernova remnant, SN 1987A. SN 1987A was the first supernova observed by naked eye in almost 400 years and has been intensely studied at all wavelengths with a wide array of telescopes and instrumentation. HST imaging has shown an equatorial ring (ER) spanning 1.6x1.2 '' in diameter [1]. This ring is believed to be material originating in an earlier stellar wind and mass-loss phase of the progenitor star and is now being heated by the supernova shock wave and is slowly increasing in brightness. Our two epochs of Spitzer observations trace the brightness evolution of the ER and reveal the composition of the ring material and the surrounding local interstellar medium. C1 [Polomski, Elisha; Woodward, C. E.; Gehrz, R. D.] Univ Minnesota, Dept Astron, 116 Church St SE, Minneapolis, MN 55455 USA. [Wooden, D. H.] NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. [Sugerman, B. E. K.] Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Polomski, E (reprint author), Univ Minnesota, Dept Astron, 116 Church St SE, Minneapolis, MN 55455 USA. FU Jet Propulsion Laboratory, California Institute of Technology, under NASA [1407]; JPL/Caltech [1275837] FX This work is based on observations made with the 'Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under NASA contract 1407. The authors were Supported in part through contract 1275837 issued by JPL/Caltech to the University of Minnesota. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0448-9 J9 AIP CONF PROC PY 2007 VL 937 BP 176 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGX54 UT WOS:000251154500023 ER PT S AU Immler, S AF Immler, Stefan BE Immler, S Weiler, K McCray, R TI X-ray emission from supernovae SO SUPERNOVA 1987A: 20 YEARS AFTER: SUPERNOVAE AND GAMMA-RAY BURSTERS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Supernova 1987A - 20 Years After CY FEB 19-23, 2007 CL Aspen, CO SP Natl Sci Fdn, NASA Goddard Space Flight Ctr, Swift Sci Ctr, XMM Newton Guest Observ Cac, Spitzer Sci Ctr, Chandra X Ray Ctr, Naval Res Lab, Univ Colorado DE X-ray; supernovae ID OUTBURST; EVOLUTION; UV AB By observing the X-ray emission from young supernovae (SNe), key physical parameters such as the circumstellar matter density in the environment of each SN, the mass lost in the progenitor's stellar winds, and the temperature of the outgoing and reverse shock can be measured. As such, X-ray observations provide a unique tool to probe the environments and explosion physics of SNe. In this article I present a brief review of all X-ray observations of SNe obtained over the past three decades, with emphasis on recent observations, and discuss implications on our understanding of the physical processes giving rise to X-rays. Using the complete sample of all SNe detected in X-rays, a coherent picture emerges that shows a dependence of the progenitors mass loss rate and environment on the Type of SN. C1 NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. RP Immler, S (reprint author), NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. NR 15 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0448-9 J9 AIP CONF PROC PY 2007 VL 937 BP 246 EP 255 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGX54 UT WOS:000251154500034 ER PT S AU Milne, PA Brown, PJ Holland, ST Roming, PWA Vanden Berk, D Immler, S AF Milne, Peter A. Brown, Peter J. Holland, Stephen T. Roming, Peter W. A. Vanden Berk, Dan Immler, Stefan BE Immler, S Weiler, K McCray, R TI Swift UVOT observations of type Ia supernovae SO SUPERNOVA 1987A: 20 YEARS AFTER: SUPERNOVAE AND GAMMA-RAY BURSTERS SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on Supernova 1987A - 20 Years After CY FEB 19-23, 2007 CL Aspen, CO SP Natl Sci Fdn, NASA Goddard Space Flight Ctr, Swift Sci Ctr, XMM Newton Guest Observ Cac, Spitzer Sci Ctr, Chandra X Ray Ctr, Naval Res Lab, Univ Colorado DE ultraviolet; supernovae ID ULTRAVIOLET; TELESCOPE AB We review recent UV observations of thermonuclear supernovae (SNe Ida) performed with the Swift Ultraviolet/Optical Telescope (UVOT) during its first two years. The UV light curves are found to have highly homogeneous light curve shapes, with peak dates that are similar to the peak dates in the U band (which is similar to 2 days earlier than in the B band). Optically-bright SNe Ia are found to be UV bright, as optically-faint SNe la are found to be UV faint. These findings are of interest for the cosmological utilization of SNe Ia as standard candles, and they afford insight into the thermonuclear explosion. The SN 2005ke was observed to feature a UV excess at late times presumably due to the SN shock encountering the circumstellar emission from a red giant donor star in the progenitor system. Collectively, Swift UV/X-ray observations of SNe la bear the promise of dramatically improving the understanding of type Ia SNe over the course of the upcoming years. C1 [Milne, Peter A.] Univ Arizona, Tucson, AZ 85721 USA. [Brown, Peter J.; Roming, Peter W. A.; Vanden Berk, Dan] Penn State Univ, Collegeville, PA 16801 USA. [Holland, Stephen T.; Immler, Stefan] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Milne, PA (reprint author), Univ Arizona, Tucson, AZ 85721 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0448-9 J9 AIP CONF PROC PY 2007 VL 937 BP 303 EP + PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGX54 UT WOS:000251154500045 ER PT S AU Brown, PJ Roming, PWA Berk, DEV Holland, ST Immler, S Milne, P AF Brown, Peter J. Roming, Peter W. A. Berk, Daniel E. Vanden Holland, Stephen T. Immler, Stefan Milne, Peter BE Immler, S Weiler, K McCray, R TI Swift UVOT observations of core-collapse SNe SO SUPERNOVA 1987A: 20 YEARS AFTER: SUPERNOVAE AND GAMMA-RAY BURSTERS SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on Supernova 1987A - 20 Years After CY FEB 19-23, 2007 CL Aspen, CO SP Natl Sci Fdn, NASA Goddard Space Flight Ctr, Swift Sci Ctr, XMM Newton Guest Observ Cac, Spitzer Sci Ctr, Chandra X Ray Ctr, Naval Res Lab, Univ Colorado DE ultraviolet; supernovae ID X-RAY OBSERVATIONS; SUPERNOVA; ULTRAVIOLET AB We review recent UV observations of core-collapse supernovae (SNe) with the Swift Ultra-violet/Optical Telescope (UVOT) during its first two years. Rest-frame UV photometry is useful for differentiating SN types by exploiting the UV-optical spectral shape and more subtle UV features. This is useful for the real-time classification of local and high-redshift SNe using only photometry. Two remarkable SNe Ib/c were observed with UVOT - SN2006jc was a UV bright SN Ib. Swift observations of GRB060218/SN2006aj began shortly after the explosion and show a UV-bright peak followed by a UV-faint SN bump. UV observations arc also useful for constraining the temperature and ionization structure of SNe IIP. Rest-frame UV observations of all hypes are important for understanding the extinction, temperature, and bolometric luminosity of SNe and to interpret the observations of high redshift SNe observed at optical wavelengths. C1 [Brown, Peter J.; Roming, Peter W. A.; Berk, Daniel E. Vanden] Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. [Holland, Stephen T.; Immler, Stefan] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. [Holland, Stephen T.; Immler, Stefan] Univ Space Res Assoc, Columbia, MD 21044 USA. [Milne, Peter] Univ Arizona, Dept Astron & Steward Observ, Tucson, AZ 85721 USA. RP Brown, PJ (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. NR 18 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0448-9 J9 AIP CONF PROC PY 2007 VL 937 BP 386 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGX54 UT WOS:000251154500057 ER PT S AU Holland, ST Immler, S Brown, PJ Roming, PWA Berk, DV Milne, PA AF Holland, Stephen T. Immler, Stefan Brown, Peter J. Roming, Peter W. A. Berk, Dan Vanden Milne, Peter A. BE Immler, S Weiler, K McCray, R TI Swift/UVOT observations of type Ib/c supernovae SO SUPERNOVA 1987A: 20 YEARS AFTER: SUPERNOVAE AND GAMMA-RAY BURSTERS SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on Supernova 1987A - 20 Years After CY FEB 19-23, 2007 CL Aspen, CO SP Natl Sci Fdn, NASA Goddard Space Flight Ctr, Swift Sci Ctr, XMM Newton Guest Observ Cac, Spitzer Sci Ctr, Chandra X Ray Ctr, Naval Res Lab, Univ Colorado DE supernova; gamma-my bursts AB Swift is an ideal observatory for studying Type Ib/c supernovae. It is able to respond rapidly to newly discovered supernovae and it is able to obtain unique near-ultraviolet photometry and spectra. To date Swift has observed 11 SNe Ib/c with long-term follow-up on two of them. SN2006aj, which is associated with GRB 060218, was observed starting a few minutes after the explosion, making it the earliest detection of a SN. SN2006jc was followed from near maximum light until it faded into its host galaxy. Mg II emission lines are seen in the UV spectrum, which are intepreted as evidence for circumstellar interaction. C1 [Holland, Stephen T.; Immler, Stefan] NASA, Goddard Space Flight Ctr, Code 660-1, Greenbelt, MD USA. [Brown, Peter J.; Roming, Peter W. A.; Berk, Dan Vanden] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. [Holland, Stephen T.; Immler, Stefan] Univ Space Res Assoc, Columbia, MD 21044 USA. [Milne, Peter A.] Univ Arizona, Dept Astron & Steward Observ, Tucson, AZ 85721 USA. RP Holland, ST (reprint author), NASA, Goddard Space Flight Ctr, Code 660-1, Greenbelt, MD USA. NR 4 TC 3 Z9 3 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0448-9 J9 AIP CONF PROC PY 2007 VL 937 BP 391 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGX54 UT WOS:000251154500058 ER PT S AU Bauer, FE Smartt, S Immler, S Brandt, WN Weiler, KW AF Bauer, F. E. Smartt, S. Immler, S. Brandt, W. N. Weiler, K. W. BE Immler, S Weiler, K McCray, R TI SN 1996cr: Confirmation of a luminous type IIn supernova in the Circinus Galaxy SO SUPERNOVA 1987A: 20 YEARS AFTER: SUPERNOVAE AND GAMMA-RAY BURSTERS SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on Supernova 1987A - 20 Years After CY FEB 19-23, 2007 CL Aspen, CO SP Natl Sci Fdn, NASA Goddard Space Flight Ctr, Swift Sci Ctr, XMM Newton Guest Observ Cac, Spitzer Sci Ctr, Chandra X Ray Ctr, Naval Res Lab, Univ Colorado DE SNe; SN 1996cr; X-ray; radio; optical; gamma-ray ID RAY BURST CONNECTION; EMISSION; CHANDRA AB We have recently confirmed SN 1996cr as a late-time type IIn supernova (SN) via VLT spectroscopy and isolated its explosion date to similar to 1 yr using archival optical imaging. We briefly touch upon here the wealth of optical, X-ray, and radio archival observations available for this enigmatic source. Due to its relative proximity (3.8 +/- 0.6 Mpc), SN 1996cr ranks among the brightest X-ray and radio SNe ever detected and, as such, may offer powerful insights into the structure and composition of type IIn SNe. We also find that SN 1996cr is matched to GRB 4B 960202 at a 2-3 sigma confidence level, making it perhaps the third GRB to be significantly associated with a type II SN. We speculate on whether SN 1996cr could be an off-axis or "failed" GRB. C1 [Bauer, F. E.] Columbia Univ, Columbia Astrophys Lab, 550 W 120th St, New York, NY 10027 USA. [Smartt, S.] Queens Univ Belfast, Dept Phys & Astron, Belfast BT7 1NN, Antrim, North Ireland. [Immler, S.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Brandt, W. N.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. [Weiler, K. W.] Naval Res Lab, Washington, DC 20375 USA. RP Bauer, FE (reprint author), Columbia Univ, Columbia Astrophys Lab, 550 W 120th St, New York, NY 10027 USA. RI Brandt, William/N-2844-2015 OI Brandt, William/0000-0002-0167-2453 NR 13 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0448-9 J9 AIP CONF PROC PY 2007 VL 937 BP 427 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGX54 UT WOS:000251154500063 ER PT S AU Gehrels, N Cannizzo, JK AF Gehrels, Neil Cannizzo, John K. BE Immler, S Weiler, K McCray, R TI Swift observations of gamma-ray bursts and supernovae SO SUPERNOVA 1987A: 20 YEARS AFTER: SUPERNOVAE AND GAMMA-RAY BURSTERS SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on Supernova 1987A - 20 Years After CY FEB 19-23, 2007 CL Aspen, CO SP Natl Sci Fdn, NASA Goddard Space Flight Ctr, Swift Sci Ctr, XMM Newton Guest Observ Cac, Spitzer Sci Ctr, Chandra X Ray Ctr, Naval Res Lab, Univ Colorado DE gamma-ray bursts; supernovae ID 28 FEBRUARY 1997; HOST GALAXY; AFTERGLOW; GRB-050709; TELESCOPE; GRB-060614; DISCOVERY; EMISSION; MISSION AB Swift is a NASA MIDEX mission with primary objective to study GRBs and use them to study the Universe. The mission was launched on 20 November 2004 and is detecting similar to 100 gamma-ray bursts (GRBs) each year. For almost every burst there is a prompt (within similar to 90 s) spacecraft repointing to give X-ray and UV/optical observations of the afterglow. Swift has already collected an impressive database including prompt emission to higher sensitivities than BATSE, uniform monitoring of afterglows, and rapid follow-up by other observatories notified through the GCN. In addition to providing extensive information on the traditional long GRBs, Swift has provided the first precise localizations of short GRBs, and has also demonstrated that supernova GRBs may comprise a yet third subset in a Venn diagram of isotropic energy versus intrinsic burst duration. The energies of these SN/GRBs are comensurate with short GRBs, while their durations are significantly longer. The acquisition of more short GRBS and of SN/GRBs over the coming years of the Swift mission will further enhance and delineate the statistical relationships among the different GRB types. C1 [Gehrels, Neil; Cannizzo, John K.] NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. [Cannizzo, John K.] Univ Maryland, Joint Ctr Astrophys, Baltimore, MD 21250 USA. RP Gehrels, N (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM gehrels@milkyway.gsfc.nasa.gov RI Gehrels, Neil/D-2971-2012 NR 34 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0448-9 J9 AIP CONF PROC PY 2007 VL 937 BP 451 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGX54 UT WOS:000251154500068 ER PT S AU Luning, K Pianetta, P Yun, WB Almeida, E van der Meulen, M AF Luening, Katharina Pianetta, Piero Yun, Wenbing Almeida, Eduardo van der Meulen, Marjolein BE Choi, JY Rah, S TI A high resolution full field transmission X-ray microscope at SSRL SO SYNCHROTRON RADIATION INSTRUMENTATION, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT 9th International Conference on Synchrotron Radiation Instrumentation (SRI 2006) CY MAY 28-JUN 02, 2006 CL Daegu, SOUTH KOREA SP Pohang Accelerator Lab, Japan Synchrotron Radiat Res Inst, Korea Minist Sci & Technol, Korea Synchrotron Radiat Users Assoc, Japanese Soc Synchrotron Radiat Res, Daegu Metropolitan City, Daegu Convent & Visitors Bur, Korea Tourism Org, Korean Phys Soc DE hard X-ray mcroscopy; TXM AB The Stanford Synchrotron Radiation Laboratory (SSRL) in collaboration with Xradia Inc., the NASA Ames Research Center and Cornell University is implementing a commercial hard x-ray full field imaging microscope based on zone plate optics on a wiggler beam line on SPEAR3. This facility will provide unprecedented analytical capabilities for a broad range of scientific areas and will enable research on nanoscale phenomena and structures in biology as well as materials science and environmental science. This instrument will provide high resolution x-ray microscopy, tomography, and spectromicroscopy capabilities in a photon energy range between 5-14 keV. The spatial resolution of the TXM microscope is specified as 20 nm exploiting imaging in third diffraction order. This imaging facility will optimally combine the latest imaging technology developed by Xradia Inc. with the wiggler source characteristics at beam line 6-2 at SSRL. This will result in an instrument capable of high speed and high resolution imaging with spectral tunability for spectromicroscopy, element specific and Zernike phase contrast imaging. Furthermore, a scanning microprobe capability will be integral to the system thus allowing elemental mapping and fluorescence yield XANES to be performed with a spatial resolution of about I pm without introducing any changes to the optical configuration of the instrument. C1 [Luening, Katharina; Pianetta, Piero] Stanford Synchrotron Radiat Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94065 USA. [Yun, Wenbing] Xradia Inc, Concord, CA 94520 USA. [Almeida, Eduardo] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [van der Meulen, Marjolein] Cornell Univ, Ithaca, NY 14853 USA. RP Luning, K (reprint author), Stanford Synchrotron Radiat Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94065 USA. FU Department of Energy; Office of Biological and Environmental Research; National Institutes of Health; National Center for Research Resources, Biomedical Technology Program FX This program is supported by the National Institutes of Health, National Institute for Biomedical Imaging and Bioengineering, grant number EB004321. Portions of this research were carried out at the Stanford Synchrotron Radiation Laboratory, a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences. The SSRL Structural Molecular Biology Program is supported by the Department of Energy, Office of Biological and Environmental Research, and by the National Institutes of Health, National Center for Research Resources, Biomedical Technology Program. NR 8 TC 2 Z9 2 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0373-4 J9 AIP CONF PROC PY 2007 VL 879 BP 1333 EP + PG 2 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Multidisciplinary SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA BFU31 UT WOS:000244647900318 ER PT S AU Hurst, J Hull, D Gorican, D AF Hurst, Janet Hull, David Gorican, Daniel BE Mullins, WM TI SYNTHESIS OF BORON NITRIDE NANOTUBES FOR ENGINEERING APPLICATIONS SO SYNTHESIS AND PROCESSING OF NANOSTRUCTURED MATERIALS SE Ceramic Engineering and Science Proceedings LA English DT Proceedings Paper CT 29th International Conference on Advanced Ceramics and Composites CT 30th International Conference and Exposition on Advanced Ceramics and Composites CY JAN 23-28, 2005 CY JAN 22-27, 2006 CL Cocoa Beach, FL CL Cocoa Beach, FL SP Amer Ceram Soc SP Amer Ceram Soc (ACerS), Engn Ceram Div (ECD) AB Boron nitride nanotubes (BNNT) are of significant interest to the scientific and technical communities for many of the same reasons that carbon nanotubes (CNT) have attracted wide attention. Both materials have potentially unique and important properties for structural and electronic applications. However of even more consequence than their similarities may be the complementary differences between carbon and boron nitride nanotubes. While BNNT possess a very high modulus similar to CNT, they also possess superior chemical and thermal stability. Additionally, BNNT have more uniform electronic properties, with a uniform band gap of 5.5 eV while CNT vary from semi-conductive to highly conductive behavior. Boron nitride nanotubes have been synthesized both in the literature and at NASA Glenn Research Center, by a variety of methods such as chemical vapor deposition, arc discharge and reactive milling. Consistent large scale production of a reliable product has proven to be difficult. Progress in the reproducible synthesis of 1-2 gram sized batches of boron nitride nanotubes will be discussed as well as potential uses for this unique material. C1 [Hurst, Janet; Hull, David] NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. [Gorican, Daniel] QSS Grp, Cleveland, OH 44135 USA. RP Hurst, J (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. FU Alternate Fuel Foundation Technologies (AFFT); Low Emissions Alternative Power (LEAP); NASA Glenn Research Center FX This work was sponsored by the Alternate Fuel Foundation Technologies (AFFT) Subproject of the Low Emissions Alternative Power (LEAP) Project at the NASA Glenn Research Center. NR 15 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 BN 978-0-470-08051-1 J9 CERAM ENG SCI PROC PY 2007 VL 27 IS 8 BP 95 EP + PG 3 WC Nanoscience & Nanotechnology; Materials Science, Ceramics SC Science & Technology - Other Topics; Materials Science GA BSM86 UT WOS:000284976400012 ER PT S AU Hunyadi, SL Lo, AS Shaklan, SB AF Hunyadi, Sarah L. Lo, Amy S. Shaklan, Stuart B. BE Coulter, DR TI The dark side of TPF - detecting and characterizing extra-solar Earth-like planets with one or two external occulters - art. no. 669303 SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE ID OBSCURATIONAL COMPLETENESS AB One of the major goals in astronomy today is the detection and characterization of extra-solar planets. There are currently many exciting new concepts on the horizon that have the capability to vastly increase our knowledge of extrasolar planets, particularly, planets like our own. The Terrestrial Planet Finder (TPF) program spans several different mission concepts that are all capable of detecting and characterizing Earth-like planets. One such concept under study consists of a telescope spacecraft and separate occulter spacecraft. The external occulters (EO) will be tens of meters in diameter and will be located thousands of kilometers away. This arrangement allows the mission to observe companion planets with a similar to 4 m telescope by extinguishing on-axis starlight. The operational efficiency of external occulters is constrained by the large separation between the telescope and the occulter spacecraft. Stewing between target stars will consume maneuvering fuel and time. Thus, the efficiency of any single EO mission may be greatly improved by using two or more occulters and optimizing the mission scenario. We explore the design of different size occulters for different objectives in the TPF mission. In one approach, a smaller occulter performs a "survey" function, while a large occulter performs follow-up searches on prospective planets and fainter celestial objects. The small occulter would have more maneuverability, but have a large inner working angle. The optimized combination of two such occulters may provide the best compromise in the mission's ability to search and characterize extra-solar planets. This paper discusses several potential TPF mission scenarios involving two occulters (one large, one small) and explores the optimization of different scenarios for detection and characterization of Earth-like planets. C1 [Hunyadi, Sarah L.; Shaklan, Stuart B.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hunyadi, SL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 171-113, Pasadena, CA 91109 USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP 69303 EP 69303 DI 10.1117/12.734321 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500002 ER PT S AU Scharf, DP Hadaegh, FY Keim, JA Benowitz, EG Lawson, PR AF Scharf, Daniel P. Hadaegh, Fred Y. Keim, Jason A. Benowitz, Edward G. Lawson, Peter R. BE Coulter, DR TI Flight-like ground demonstration of precision formation flying spacecraft - art. no. 669307 SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE precision formation flying; robotic testbed; ground demonstration; formation infrastructure ID GUIDANCE; NAVIGATION; MISSION; DESIGN AB Initial high-fidelity, flight-like ground demonstrations of precision formation flying spacecraft are presented. In these demonstrations, maneuvers required for distributed spacecraft interferometry, such as for the Terrestrial Planet Finder Interferometer, were performed to near-flight precision. Synchronized formation rotations for "on-the-fly" observations require the highest precision. For this maneuver, ground demonstration performance requirements are 5 cm in relative position and 6 arc minutes in attitude. These requirements have been met for initial demonstrations of formation-keeping and synchronized formation rotations. The maneuvers were demonstrated in the Formation Control Testbed (FCT). The FCT currently consists of two, five degree-of-freedom, air bearing-levitated robots. The final sixth degree-of-freedom is being added in August 2007. Each robot has a suite of flight-like avionics and actuators, including a star tracker, fiber-optic gyroscopes, reaction wheels, cold-gas thrusters, inter-robot communication, and on-board computers that run the Formation and Attitude Control System (FACS) software. The FCT robots and testbed environment are described in detail. Then several initial demonstrations results are presented, including (i) a sub-millimeter formation sensor, (ii) an algorithm for synchronizing control cycles across multiple vehicles, (iii) formation keeping, (iv) reactive collision avoidance, and (iv) synchronized formation rotations. C1 [Scharf, Daniel P.; Hadaegh, Fred Y.; Keim, Jason A.; Benowitz, Edward G.; Lawson, Peter R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Scharf, DP (reprint author), CALTECH, Jet Prop Lab, MS 198-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 23 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP 69307 EP 69307 DI 10.1117/12.735125 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500006 ER PT S AU Lawson, PR Lay, OP Martin, SR Beichman, CA Johnston, KJ Danchi, WC Gappinger, RO Hunyadi, SL Ksendzov, A Mennesson, B Peters, RD Scharf, DP Serabyn, E Unwin, SC AF Lawson, P. R. Lay, O. P. Martin, S. R. Beichman, C. A. Johnston, K. J. Danchi, W. C. Gappinger, R. O. Hunyadi, S. L. Ksendzov, A. Mennesson, B. Peters, R. D. Scharf, D. P. Serabyn, E. Unwin, S. C. BE Coulter, DR TI Terrestrial planet finder interferometer 2006-2007 progress and plans - art. no. 669308 SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE interferometry; astronomy; extrasolar planets; nulling; formation flying ID EARTH-LIKE PLANETS; LIFE AB This paper provides an overview of technology development for the Terrestrial Planet Finder Interferometer (TPF-I). TPF-I is a mid-infrared space interferometer being designed with the capability of detecting Earth-like planets in the habitable zones around nearby stars. The overall technology roadmap, is presented and progress with each of the testbeds is summarized. The current interferometer architecture, design trades, and the viability of possible reduced-scope mission concepts are also presented. C1 [Lawson, P. R.; Lay, O. P.; Martin, S. R.; Gappinger, R. O.; Hunyadi, S. L.; Ksendzov, A.; Mennesson, B.; Peters, R. D.; Scharf, D. P.; Serabyn, E.; Unwin, S. C.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lawson, PR (reprint author), CALTECH, Jet Prop Lab, MS 301-451,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP 69308 EP 69308 DI 10.1117/12.734914 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500007 ER PT S AU Martin, SR Scharf, D Wirz, R Lay, O McKinstry, D Mennesson, B Purcell, G Rodriguez, J Scherr, L Smith, JR Wayne, L AF Martin, Stefan R. Scharf, Daniel Wirz, Richard Lay, Oliver McKinstry, David Mennesson, Bertrand Purcell, George Rodriguez, Jose Scherr, Laurence Smith, James R. Wayne, Leonard BE Coulter, DR TI TPF-Emma: concept study of a planet finding space interferometer - art. no. 669309 SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE TPF; stellar interferometry; exoplanets AB A novel space interferometer design originating in Europe has been studied. The interferometer uses the technique of starlight nulling to enable detection of earth-like planets orbiting nearby stars. A set of four telescope spacecraft flying in formation with a fifth, beam-combiner spacecraft forms the interferometer. Ibis particular concept shows potential for reducing the mission cost when compared with previous concepts by greatly reducing the complexity of the telescope spacecraft. These spacecraft have no major deployable systems, have simplified propulsion and a more rugged construction. The formation flying geometry provides for greater average separation between the spacecraft with commensurate risk reduction. Key aspects of the design have been studied at the Jet Propulsion Laboratory with a view to collaborations between NASA and the European Space Agency. An overview of the design study is presented with some comparisons with the TPF-FFI concept. C1 [Martin, Stefan R.; Scharf, Daniel; Wirz, Richard; Lay, Oliver; McKinstry, David; Mennesson, Bertrand; Purcell, George; Rodriguez, Jose; Scherr, Laurence; Smith, James R.; Wayne, Leonard] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Martin, SR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP 69309 EP 69309 DI 10.1117/12.734835 PG 9 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500008 ER PT S AU Peters, RD Lay, OP Hirai, A Jeganathan, M AF Peters, Robert D. Lay, Oliver P. Hirai, Akiko Jeganathan, Muthu BE Coulter, DR TI Adaptive nulling in the mid-IR for the terrestrial planet finder interferometer - art. no. 669315 SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE nulling interferometry; planet detection; deformable mirror; dispersion compensator; nulling; amplitude and phase correction; adaptive nuller AB Deep,, stable starlight nulls are needed for the direct detection of Earth-like planets and require careful control of the intensity and phase of the beams that are being combined. We have tested a novel compensator based on a deformable mirror to correct the intensity and phase at each wavelength across the bandwidth of 8 to 12 microns wavelength. This paper will cover the results of the adaptive nuller tests performed in the mid-IR. C1 [Peters, Robert D.; Lay, Oliver P.; Hirai, Akiko; Jeganathan, Muthu] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Peters, RD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP 69315 EP 69315 DI 10.1117/12.734775 PG 8 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500033 ER PT S AU Gappinger, RO Diaz, RT Martin, SR Loya, FM Lawson, PR AF Gappinger, Robert O. Diaz, Rosemary T. Martin, Stefan R. Loya, Frank M. Lawson, Peter R. BE Coulter, DR TI Current progress on TPF-I mid-infrared achromatic nulling at the Jet Propulsion Laboratory - art. no. 669318 SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE exoplanet detection; nulling interferometry; terrestrial planet finder AB Infrared interferometric nulling is a promising technology for exoplanet detection. Nulling research for the Terrestrial Planet Finder Interferometer has explored several interferometer architectures at the Jet Propulsion Laboratory (JPL). The most recent efforts have focused on an architecture which employs a geometric field flip to achieve the necessary pi phase delay in the interferometer. The periscope design currently in use allows for a completely achromatic phase flip. Deep interferometric nulling requires optical path stability, precision optical alignment, intensity balancing, and dispersion correction. This paper will discuss recent efforts to implement a precision optical alignment, stabilize the interferometer environment, implement optical path metrology, control intensity balance, and compensate for dispersion introduced by beamsplitter mismatch. C1 [Gappinger, Robert O.; Diaz, Rosemary T.; Martin, Stefan R.; Loya, Frank M.; Lawson, Peter R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gappinger, RO (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP 69318 EP 69318 DI 10.1117/12.736023 PG 8 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500036 ER PT S AU Lay, OP Martin, SR Hunyadi, SL AF Lay, Oliver P. Martin, Stefan R. Hunyadi, Sarah L. BE Coulter, DR TI Planet-finding performance of the TPF-I Emma architecture - art. no. 66930A SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE optical interferometry; nulling; planet detection ID INTERFEROMETERS AB The NASA Terrestrial Planet Finder Interferometer (TPF-I) and ESA Darwin missions are designed to directly detect mid-infrared photons from earth-like planets around nearby stars. Until recently, the baseline TPF-I design was the planar stretched X-Array, in which the four collectors spacecraft lie on the corners of a rectangle with the combiner spacecraft at the center, all in the plane normal to the direction to the target star. The stretched X-Array has two major advantages over other configurations: the angular resolution is very high, and the ability to eliminate instability noise. A direct consequence of the latter is that the null depth requirement is relaxed from 10(-6) to 10(-5). Implementation of the planar configuration requires a significant number of deployments, however, including large sunshades and secondary mirror supports. ESA had been pursuing a non-planar configuration with 3 collector telescopes. Dubbed the 'Emma' architecture (after the wife of Charles Darwin), this approach brings the combiner spacecraft up out of the plane of the collectors, and offers significant simplifications in the collector design with minimal deployments. The Emma X-Array combines the best aspects of each design, bringing together the 4-collector stretched X-Array collector configuration with the out-of-plane combiner of the Emma geometry. Both the TPF-I and Darwin missions have now adopted the Emma X-Array as the baseline design, moving a step closer to a single, joint TPF/Darwin mission. In this paper we assess the planet-finding performance of the Emma X-Array. An optimized completeness algorithm is used to estimate the number of Earths that can be found as a function of collector diameter. Other key parameters - the inner and outer working angles and the angular resolution - are also addressed. C1 [Lay, Oliver P.; Martin, Stefan R.; Hunyadi, Sarah L.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lay, OP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP A6930 EP A6930 DI 10.1117/12.732230 PG 9 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500009 ER PT S AU Sidick, E Kern, B Kuhnert, AC AF Sidick, Erkin Kern, Brian Kuhnert, Andreas C. BE Coulter, DR TI Optimizing the broadband performance of TPF's high-contrast imaging testbed through modeling and simulations - art. no. 66931B SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE TPF; integrated modeling; speckle-nulling; high-contrast coronagraph AB We have carried out some investigation to optimize the broadband performance of the high-contrast imaging testbed (HCIT) at JPL through optical modeling and simulations. The analytical tool is an optical simulation algorithm developed by combining the HCIT's optical model with a speckle-nulling algorithm that operates directly on coronagraphic images, an algorithm very similar to the one that has been used on the HCIT. We have experimented in our simulations with different designs for the occulting mask and the Lyot Stop, and also tried several different speckle-nulling approaches. Some results predicted by our simulations agree well with the results measured on the HCIT. In this paper we describe the details of our simulations and present our results. C1 [Sidick, Erkin; Kern, Brian; Kuhnert, Andreas C.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sidick, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP B6931 EP B6931 DI 10.1117/12.731676 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500038 ER PT S AU Shao, M Unwin, SC Beichman, C Catanzarite, J Edberg, SJ Marr, JC Marcy, G AF Shao, Michael Unwin, Stephen C. Beichman, Charles Catanzarite, Joseph Edberg, Stephen J. Marr, James C. Marcy, Geoffrey BE Coulter, DR TI Finding Earth clones with SIM: The most promising near-term technique to detect, find masses for, and determine three-dimensional orbits of nearby habitable planets - art. no. 66930C SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE ID GIANT PLANETS; MODEL; COMPANION; STARS; GAS AB SIM is a space astrometric interferometer capable of better than one-microarcsecond (mu as) single measurement accuracy, providing the capability to detect stellar "wobble" resulting from planets in orbit around nearby stars. While a search for exoplanets can be optimized in a variety of ways, a SIM five-year search optimized to detect Earth analogs (0.3 to 10 Earth masses) in the middle of the habitable zone (HZ) of nearby stars would yield the masses, without M*sin(i) ambiguity, and three-dimensional orbital parameters for planets around similar to 70 stars, including those in the HZ and further away from those same stars. With >200 known planets outside our solar system, astrophysical theorists have built numerical models of planet formation that match the distribution of Jovian planets discovered to date and those models predict that the number of terrestrial planets (< 10 M-circle plus) would far exceed the number of more massive Jovian planets. Even so, not every star will have an Earth analog in the middle of its HZ. This paper describes the relationship between SIM and other planet detection methods, the SIM planet observing program, expected results, and the state of technical readiness for the SIM mission. C1 [Shao, Michael; Unwin, Stephen C.; Catanzarite, Joseph; Edberg, Stephen J.; Marr, James C.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shao, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP C6930 EP C6930 DI 10.1117/12.734671 PG 8 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500011 ER PT S AU Sidick, E Balasubranianian, K AF Sidick, Erkin Balasubranianian, Kunjithapatham BE Coulter, DR TI Effects of optical-density and phase dispersion of an imperfect band-limited occulting mask on the broadband performance of a TPF coronagraph - art. no. 66931C SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE TPF; integrated modeling; speckle-nulling; high-contrast coronagraph AB Practical image-plane occulting masks required by high-contrast imaging systems such as the TPF-Coronagraph introduce phase errors into the transmitting beam, or, equivalently, diffract the residual starlight into the area of the final image plane used for detecting exo-planets. Our group at JPL has recently proposed spatially profiled metal masks that can be designed to have zero parasitic phases at the center wavelength of the incoming broadband light with small amounts of OD and phase dispersions at other wavelengths. Work is currently underway to design, fabricate and characterize such image-plane masks. In order to gain some understanding on the behaviors of these new imperfect band-limited occulting masks and clarify how such masks utilizing different metals or alloys compare with each other, we carried out some modeling and simulations on the contrast performance of the high-contrast imaging testbed (HCIT) at JPL. In this paper we describe the details of our simulations and present our results. C1 [Sidick, Erkin; Balasubranianian, Kunjithapatham] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sidick, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP C6931 EP C6931 DI 10.1117/12.731678 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500039 ER PT S AU Edberg, SJ Laskin, RA Marr, JC Unwin, SC Shao, M AF Edberg, Stephen J. Laskin, Robert A. Marr, James C. Unwin, Stephen C. Shao, Michael BE Coulter, DR TI SIM PlanetQuest Science & Technology: A status report - art. no. 66930D SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE optical inteferometry; astrometry; astrophysics; planet search AB Optical interferometry will open new vistas for astronomy over the next decade. The Space Interferometry Mission (SIM-PlanetQuest), operating unfettered by the Earth's atmosphere, will offer unprecedented astrometric precision that promises the discovery of Earth-analog extra-solar planets as well as a wealth of important astrophysics. Results from SIM will permit the determination of stellar masses to accuracies of 2% or better for objects ranging from brown dwarfs through main sequence stars to evolved white dwarfs, neutron stars, and black holes. Studies of star clusters will yield age determinations and internal dynamics. Microlensing measurements will present the mass spectrum of the Milky Way internal to the Sun while proper motion surveys will show the Sun's orbital radius and speed. Studies of the Galaxy's halo component and companion dwarf galaxies permit the determination of the Milky Way's mass distribution, including its Dark Matter component and the mass distribution and Dark Matter component of the Local Group. Cosmology benefits from precision (1-2%) determination of distances to Cepheid and RR Lyrae standard candles. The emission mechanism of supermassive black holes will be investigated. Finally, radio and optical celestial reference frames will be tied together by an improvement of two orders of magnitude. Optical interferometers present severe technological challenges. The Jet Propulsion Laboratory, with the support of Lockheed Martin Advanced Technology Center (LM ATC) and Northrop Grumman Space Technology (NGST), has addressed these challenges with a technology development program that is now complete. The requirements for SIM have been satisfied, based on outside peer review, using a series of laboratory tests and appropriate computer simulations: laser metrology systems perform with 10 picometer precision; mechanical vibrations have been controlled to nanometers, demonstrating orders of magnitude disturbance rejection; and knowledge of component positions throughout the whole test assembly has been demonstrated to the required picometer level. Technology transfer to the SIM flight team is now well along. C1 [Edberg, Stephen J.; Laskin, Robert A.; Marr, James C.; Unwin, Stephen C.; Shao, Michael] NASA, CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Edberg, SJ (reprint author), NASA, CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP D6930 EP D6930 DI 10.1117/12.732728 PG 17 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500012 ER PT S AU Milman, MH Regehr, M Zhai, CX AF Milman, Mark H. Regehr, Martin Zhai, Chengxing BE Coulter, DR TI SIM PlanetQuest precision white light interferometry - art. no. 66930E SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE white light interferometry; vibration; polarization ID PHASE-SHIFTING INTERFEROMETRY; ERROR AB Precision white light interferometry performed at the picometer class level is an extremely challenging endeavor. Over the past several years a combination of analysis, experiment, and reconciliation of the two has yielded continued improvements and refinements of the process to bring this technology to fruition. This paper provides an overview of several of the refinements of the interference models and algorithms developed for calibration and fringe estimation that have evolved over this period. C1 [Milman, Mark H.; Regehr, Martin; Zhai, Chengxing] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Milman, MH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP E6930 EP E6930 DI 10.1117/12.732530 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500013 ER PT S AU Kern, B Wilson, DW AF Kern, Brian Wilson, Daniel W. BE Coulter, DR TI Wavelength-dependent complex transmission profiles of band-limited coronagraph occulting masks measured in-situ - art. no. 66931F SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE terrestrial planet finder; coronagraph; band-limited mask AB Practical band-limited occulting masks used in visible-light Lyot coronagraphs, such as those proposed for the Terrestrial Planet Finder Coronagraph (TPF-C), will exhibit some non-band-limited transmission errors that may limit their observing contrast ratios to unacceptable levels. The complex (both phase and amplitude) transmission profiles of these masks exhibit large dynamic ranges over small spatial scales, which are difficult to probe using ordinary optical microscopes and interferometers. We describe here a technique for making these complex transmission measurements with the mask in-place in a Lyot coronagraph, using point-source images taken in the focal and pupil planes, with the Lyot stop removed. We also present measurements taken from the High-Contrast Imaging Testbed (HCIT) at JPL. C1 [Kern, Brian; Wilson, Daniel W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kern, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP F6931 EP F6931 DI 10.1117/12.733949 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500042 ER PT S AU Greene, T Beichman, C Eisenstein, D Horner, S Kelly, D Mao, Y Meyer, M Rieke, M Shi, F AF Greene, Thomas Beichman, Charles Eisenstein, Daniel Horner, Scott Kelly, Douglas Mao, Yalan Meyer, Michael Rieke, Marcia Shi, Fang BE Coulter, DR TI Observing exoplanets with the JWST NIRCam grisms - art. no. 66930G SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE NIRCam; grisms; JWST; near-infrared; exoplanets; spectroscopy ID SPACE-TELESCOPE AB The near-infrared camera (NIRCam) on the James Webb Space Telescope (JWST) will incorporate 2 identical grisms in each of its 2 long wavelength channels. These transmission gratings have been added to assist with the coarse phasing of the JWST telescope, but they will also be used for slitless wide-field scientific observations over selectable regions of the lambda = 2.4 - 5.0 mu m wavelength range at spectroscopic resolution R equivalent to lambda/delta lambda similar or equal to 2000. We describe the grism design details and their expected performance in NIRCam. The grisms will provide point-source continuum sensitivity of approximately AB = 23 mag in 10,000 s exposures with S/N = 5 when binned to R = 1000. This is approximately a factor of 3 worse than expected for the JWST NIRSpec instrument, but the NIRCam grisms provide better spatial resolution, better spectrophotometric precision, and complete field coverage. The grisms will be especially useful for high precision spectrophotometric observations of transiting exoplanets. We expect that R = 500 spectra of the primary transits and secondary eclipses of Jupiter-sized exoplanets can be acquired at moderate or high signal-to-noise for stars as faint as M = 10 - 12 mag in 1000 s of integration time, and even bright stars (V = 5 mag) should be observable without saturation. We also discuss briefly how these observations will open up new areas of exoplanet science and suggest other unique scientific applications of the grisms. C1 [Greene, Thomas] NASA, Ames Res Ctr, Moffett Field, CA 94062 USA. RP Greene, T (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94062 USA. NR 14 TC 6 Z9 6 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP G6930 EP G6930 DI 10.1117/12.732506 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500014 ER PT S AU Krist, JE Beichman, CA Trauger, JT Rieke, MJ Somerstein, S Green, JJ Horner, SD Stansberry, JA Shi, F Meyer, MR Stapelfeldt, KR Roellig, TL AF Krist, John E. Beichman, Charles A. Trauger, John T. Rieke, Marcia J. Somerstein, Steve Green, Joseph J. Horner, Scott D. Stansberry, John A. Shi, Fang Meyer, Michael R. Stapelfeldt, Karl R. Roellig, Thomas L. BE Coulter, DR TI Hunting planets and observing disks with the JWST NIRCam coronagraph - art. no. 66930H SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE James Webb Space Telescope; NIRCam; coronagraph; extrasolar planets; circumstellar disks ID SPACE-TELESCOPE AB The expected stable point spread function, wide field of view, and sensitivity of the NIRCam instrument on the James Webb Space Telescope (JWST) will allow a simple, classical Lyot coronagraph to detect warm Jovian-mass companions orbiting young stars within 150 pc as well as cool Jupiters around the nearest low-mass stars. The coronagraph can also be used to study protostellar and debris disks. At lambda = 4.5 mu m, where young planets are particularly bright relative to their stars, and at separations beyond similar to 0.5 arcseconds, the low space background gives JWST significant advantages over ground-based telescopes equipped with adaptive optics. We discuss the scientific capabilities of the NIRCam coronagraph, describe the technical features of the instrument, and present end-to-end simulations of coronagraphic observations of planets and circumstellar disks. C1 [Krist, John E.; Beichman, Charles A.; Trauger, John T.; Green, Joseph J.; Shi, Fang; Stapelfeldt, Karl R.] NASA, Jet Prop Lab, Pasadena, CA 91109 USA. RP Krist, JE (reprint author), NASA, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Stapelfeldt, Karl/D-2721-2012 NR 8 TC 13 Z9 13 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP H6930 EP H6930 DI 10.1117/12.734873 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500015 ER PT S AU Moody, DC Trauger, JT AF Moody, D. C. Trauger, J. T. BE Coulter, DR TI Hybrid Lyot coronagraph masks and wavefront control for improved spectral bandwidth and throughput - art. no. 66931I SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE coronagraphs; high contrast; active optics; space astronomy ID PLANET; IMAGE AB Coronagraph focal-plane occulting masks have generally been described as attenuation profiles free of any phase shift. However, phase shifts are expected and observed in physical occulting masks, and they can impose significant limitations on coronagraph contrast at the billion-to-one level in spectrally broad light, as required for the direct imaging of planetary systems orbiting the nearby stars. Here we explore design options for a physically realizable occulting mask composed of a metallic and a dielectric thin film, each profiled in thickness and superimposed on a glass substrate. We show that such hybrid masks, together with a deformable mirror for control of wavefront phase, offer contrast performance better than 10(-9) over spectral bandwidths up to 30% with Lyot coronagraph throughput efficiencies of 66% or more. C1 [Moody, D. C.; Trauger, J. T.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Moody, DC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP I6931 EP I6931 DI 10.1117/12.735070 PG 9 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500045 ER PT S AU Hunyadi, SL Shaklan, SB Brown, RA AF Hunyadi, Sarah L. Shaklan, Stuart B. Brown, Robert A. BE Coulter, DR TI The lighter side of TPF-C - Evaluating the scientific gain from a smaller mission concept - art. no. 66930Q SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE ID OBSCURATIONAL COMPLETENESS AB For the past several years NASA has been developing the Terrestrial Planet Finder Coronagraph (TPF-C), a space based telescope mission to look for Earth-like extra-solar planets. By evaluating the cumulative number of habitable zones observable with a given observation sequence (completeness) we test the relative merits of the baseline 8-m telescope design and smaller (2.5 - 4 m), less capable TPF-C designs based on various coronagraph technologies as well as external occulters. C1 [Hunyadi, Sarah L.; Shaklan, Stuart B.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hunyadi, SL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 171-113, Pasadena, CA 91109 USA. NR 8 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP Q6930 EP Q6930 DI 10.1117/12.733454 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500021 ER PT S AU Shaklan, SB Give'on, A Belikov, R Pueyo, L AF Shaklan, Stuart B. Give'on, Arnir Belikov, Ruslan Pueyo, Laurent BE Coulter, DR TI Broadband wavefront control in a pupil mapping coronagraph - art. no. 66930R SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE coronagraph; high-contrast imaging; PIAA; pupil mapping; telescope requirements ID INDUCED AMPLITUDE APODIZATION; PHASE AB Pupil mapping (a.k.a. Phase-Induced Amplitude Apodization, or PIAA) is a promising technique in high-dynamic range stellar coronagraphy that obtains higher throughput and better inner working angle than any other known approach. As with any coronagraph, the optical surface requirements and the diameter of the controllable region in the image plane are tied to the wavefront control system and optical bandpass. For example, in a monochromatic bandpass, a single ideal deformable mirror (DM) can create a dark hole with a diameter limited by its Nyquist frequency, even for highly aberrated optics. In broadband light, the depth of the dark hole is linked to the wavelength dependence of aberrations, their spatial frequency content, and their propagation through the system. We derive requirements on the surface height and reflectivity power spectral densities for optics in the PIAA system and describe a sequential-DM architecture that will achieve high-contrast over a large optical bandwidth. C1 [Shaklan, Stuart B.; Give'on, Arnir] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shaklan, SB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 14 TC 2 Z9 2 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP R6930 EP R6930 DI 10.1117/12.734943 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500022 ER PT S AU Trauger, J Give'on, A Gordon, B Kern, B Kuhnert, A Moody, D Niessner, A Shi, F Wilson, D Burrows, C AF Trauger, John Give'on, Amir Gordon, Brian Kern, Brian Kuhnert, Andreas Moody, Dwight Niessner, Albert Shi, Fang Wilson, Daniel Burrows, Chris BE Coulter, DR TI Laboratory demonstrations of high-contrast imaging for space coronagraphy - art. no. 66930X SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE active optics; coronagraphs; space astronomy ID PLANET AB Space coronagraphy is a promising method for direct imaging of planetary systems orbiting the nearby stars. The High Contrast Imaging Testbed is a laboratory facility at JPL that integrates the essential hardware and control algorithms needed for suppression of diffracted and scattered light near a target star that would otherwise obscure an associated exo-planetary system. Stable suppression of starlight by a factor of 5x10(-10) has been demonstrated consistently in narrowband light over fields of view as close as four Airy radii from the star. Recent progress includes the extension of spectral bandwidths to 10% at contrast levels of 2x10(-9), with work in progress to further improve contrast levels, bandwidth, and instrument throughput. We summarize recent laboratory results and outline future directions. This laboratory experience is used to refine computational models, leading to performance and tolerance predictions for future space mission architectures. C1 [Trauger, John; Give'on, Amir; Gordon, Brian; Kern, Brian; Kuhnert, Andreas; Moody, Dwight; Niessner, Albert; Shi, Fang; Wilson, Daniel] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Trauger, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 17 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP X6930 EP X6930 DI 10.1117/12.735004 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500026 ER PT S AU Balasubramanian, K Wilson, DW Muller, RE Kern, BD Sidick, E AF Balasubramanian, Kunjithapatham Wilson, Daniel W. Muller, Richard E. Kern, Brian D. Sidick, Erkin BE Coulter, DR TI Thickness-dependent optical properties of metals and alloys applicable to TPF coronagraph image masks - art. no. 66930Z SO TECHNIQUES AND INSTUMENTATION FOR DETECTION OF EXOPLANETS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets III CY AUG 28-30, 2007 CL San Diego, CA SP SPIE DE optical properties; Ni; Pt; Inconel; thin films; TPF; coronagraph AB Some common metals and alloys have been identified as potential candidates with optical properties applicable to image plane masks for terrestrial planet finder (TPF) coronagraph especially for broad band performance in the visible spectrum. Thin films of these materials exhibit thickness dependence of refractive index and extinction coefficient which vary with wavelength and consequently the intensity and phase of transmitted light. We report on the fabrication and measurement of thickness-dependent optical properties of thin films of Ni, Pt and Inconel alloys to enable optimum design of image plane masks for Lyot coronagraphs to operate in the 500 to 800 run band. We discuss the potential and limitations of practical masks with such materials. C1 [Balasubramanian, Kunjithapatham; Wilson, Daniel W.; Muller, Richard E.; Kern, Brian D.; Sidick, Erkin] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Balasubramanian, K (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6841-3 J9 P SOC PHOTO-OPT INS PY 2007 VL 6693 BP Z6930 EP Z6930 DI 10.1117/12.732721 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHD80 UT WOS:000252361500028 ER PT J AU Conway, EM AF Conway, Erik M. TI Realizing the dream of flight: Biographical essays in honor of the centennial of flight, 1903-2003. SO TECHNOLOGY AND CULTURE LA English DT Book Review C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Conway, EM (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4363 USA SN 0040-165X J9 TECHNOL CULT JI Technol. Cult. PD JAN PY 2007 VL 48 IS 1 BP 232 EP 234 DI 10.1353/tech.2007.0009 PG 3 WC History & Philosophy Of Science SC History & Philosophy of Science GA 132NQ UT WOS:000243949900045 ER PT S AU Chubb, DL AF Chubb, Donald L. BE Algora, C Corregidor, V TI Light pipe thermophotovoltaics (LTPV) SO Thermophotovoltaic Generation of Electricity SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th World Conference on Thermophotovoltaic Generation of Electricity CY SEP 25-27, 2006 CL Madrid, SPAIN SP Univ Politecn Madrid, Univ Autonoma Madrid, FULLSPECTRUM European Integrated Project, Aixtron AG, Epichem Grp, Prorinnovabili, IEEE, IEEE Electron Devices Soc DE thermophotovoltaics; light pipe; energy conversion AB In a conventional thermophotovoltaic (TPV) energy converter the radiation from the emitter to the photovoltaic (PV) array is transmitted in a vacuum or air where the index of refraction, n = 1. The intensity of the radiation is proportional to n(2). Therefore, die incident intensity on the PV array could be greatly increase if the medium between the emitter and the PV array had n > 1. This light pipe TPV (LTPV) concept was introduced by The Quantum Group [1] at the Third National Renewable Energy Laboratory (NREL) TPV Conference in 1997. This paper presents a theoretical analysis of the LTPV concept. The solution of the one-dimensional energy equation that includes both thermal conduction and radiation yields the temperature distribution through the light pipe. Applying the analysis to a zinc selenide (ZnSe) light pipe yielded the following result. For an emitter temperature of 1000K the convertible radiation(photon energy >PV bandgap energy) that reaches the photovoltaic(PV) cell is 1 W/cm(2). At the same emitter temperature, a conventional TPV converter would have 1/8 W/cm(2) of convertible radiation. Thus, the LTPV concept makes possible lower temperature operation than current TPV converters. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Chubb, DL (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS302-1, Cleveland, OH 44135 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0392-5 J9 AIP CONF PROC PY 2007 VL 890 BP 297 EP 316 PG 20 WC Energy & Fuels; Engineering, Electrical & Electronic; Physics, Multidisciplinary SC Energy & Fuels; Engineering; Physics GA BGA46 UT WOS:000245806800034 ER PT S AU Wilt, D Chubb, D Wolford, D Magari, P Crowley, C AF Wilt, David Chubb, Donald Wolford, David Magari, Patrick Crowley, Chris BE Algora, C Corregidor, V TI Thermophotovoltaics for space power applications SO Thermophotovoltaic Generation of Electricity SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th World Conference on Thermophotovoltaic Generation of Electricity CY SEP 25-27, 2006 CL Madrid, SPAIN SP Univ Politecn Madrid, Univ Autonoma Madrid, FULLSPECTRUM European Integrated Project, Aixtron AG, Epichem Grp, Prorinnovabili, IEEE, IEEE Electron Devices Soc DE thermophotovoltaic; energy conversion; space power AB Thermophotovoltaic (TPV) energy conversion has long been considered a potential replacement for thermoelectrics in radioisotope powered deep space power systems. In this application, TPV offers significant potential improvements in both efficiency and mass specific power (W/kg), performance which is considered mission enabling for a variety of mission concepts. TPV systems powered by concentrated solar energy have also been proposed for inner planetary solar system missions. This concept takes advantage of TPV's ability to store energy for shadow periods in the form of heat energy rather than as electrical energy (batteries), as is commonly done for photovoltaic power systems. The simplicity and large number of power cycles offered by the thermal energy storage offers potential system benefits compared to a photovoltaic / battery system. Recent efforts in the development of radioisotope TPV (RTPV) at Creare have resulted in the demonstration of converter efficiencies in excess of 19%. Several independent system mass analyses have been performed for the Creare RTPV system and they predict specific powers above 10W/kg at the system level. Trades have suggested increasing the rejection temperature can result in a 50% reduction in radiator area while only suffering a 15% reduction in mass specific power. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Creare, D-03755 Hannover, Germany. RP Wilt, D (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 7 TC 6 Z9 6 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0392-5 J9 AIP CONF PROC PY 2007 VL 890 BP 335 EP 345 PG 11 WC Energy & Fuels; Engineering, Electrical & Electronic; Physics, Multidisciplinary SC Energy & Fuels; Engineering; Physics GA BGA46 UT WOS:000245806800037 ER PT B AU Wang, C Newman, TS Gallagher, D AF Wang, Cuilan Newman, Timothy S. Gallagher, Dennis BE Pollefeys, M Daniilidis, K TI Synthesis of 3D model of a magnetic field-influenced body from a single image SO THIRD INTERNATIONAL SYMPOSIUM ON 3D DATA PROCESSING, VISUALIZATION, AND TRANSMISSION, PROCEEDINGS LA English DT Proceedings Paper CT 3rd International Symposium on 3D Data Processing, Visualization and Transmission CY JUN 14-16, 2006 CL Univ North Carolina, Chapel Hill, NC HO Univ North Carolina ID RECONSTRUCTION AB A method for recovery of a 3D model of a planet-sized cloud-like structure that is in motion and deforming but approximately governed by magnetic field properties is described. The method allows recovery of the model from a single intensity image in which the structure's silhouette can be observed. The method exploits envelope theory and a magnetic field model. Given one intensity image and the segmented silhouette in the image, the method proceeds without human intervention to produce the 3D model. In addition to allowing 3D model synthesis, the method's capability to yield a very compact description offers further utility. Application of the method to real-world data is also demonstrated. C1 [Wang, Cuilan; Newman, Timothy S.] Univ Alabama, Dept Comp Sci, Huntsville, AL 35899 USA. [Gallagher, Dennis] NASA Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL USA. RP Wang, C (reprint author), Univ Alabama, Dept Comp Sci, Huntsville, AL 35899 USA. FU NASA Science Mission Directorate [NAG5-12109] FX The work described here was partially supported by the NASA Science Mission Directorate under grant NAG5-12109 NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 978-0-7695-2825-0 PY 2007 BP 1018 EP 1025 PG 8 WC Computer Science, Software Engineering; Imaging Science & Photographic Technology; Telecommunications SC Computer Science; Imaging Science & Photographic Technology; Telecommunications GA BGN52 UT WOS:000248621700130 ER PT S AU Prestage, JD Chung, SK Lim, L Le, T AF Prestage, John D. Chung, Sang K. Lim, Lawrence Le, Thanh BE Jones, RJ TI Hg ion atomic clock for deep space navigation and science - art. no. 667306 SO Time and Frequency Metrology SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Time and Frequency Metrology CY AUG 29-30, 2007 CL San Diego, CA DE atomic clock; space clock; mercury ion clock AB We have recently completed a breadboard ion-clock physics package based on Hg ions shuttled between a quadrupole and a 16-pole rf trap. With this architecture we have demonstrated short-term stability similar to 1-2x10(-13) at 1 second, averaging to 10(-15) at 1 day. This development shows that H-maser quality stabilities can be produced in a small clock package, comparable in size to an ultra-stable quartz oscillator required for holding 1-2x10(-13) at I second. This performance was obtained in a sealed vacuum configuration where only a getter pump was used to maintain vacuum. The vacuum tube containing the traps has now been under sealed vacuum conditions for nearly two years with no measurable degradation of ion trapping lifetimes or clock short-term performance. We have fabricated the vacuum tube, ion trap and UV windows from materials that will allow a similar to 400 degrees C tube bake-out to prepare for tube seal-off. This approach to the vacuum follows the methods used in flight vacuum tube electronics, such as flight TWTA's where tube operation lifetime and shelf life of up to 15 years is achieved. We use neon as a buffer gas with 2-3 times less pressure induced frequency pulling than helium and, being heavier, negligible diffusion losses will occur over the operation lifetime. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Prestage, JD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6821-5 J9 P SOC PHOTO-OPT INS PY 2007 VL 6673 BP 67306 EP 67306 AR 667306 DI 10.1117/12.734725 PG 8 WC Instruments & Instrumentation; Optics; Spectroscopy SC Instruments & Instrumentation; Optics; Spectroscopy GA BGX08 UT WOS:000251051000003 ER PT S AU Anand, S Pasareanu, CS Visser, W AF Anand, Saswat Pasareanu, Corina S. Visser, Willem BE Grumberg, O Huth, M TI JPF-SE: A symbolic execution extension to Java PathFinder SO TOOLS AND ALGORITHMS FOR THE CONSTRUCTION AND ANALYSIS OF SYSTEMS, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Proceedings Paper CT 13th International Conference on Tools and Algorithms for the Construction and Analysis of Systems CY MAR 24-APR 01, 2007 CL Braga, PORTUGAL AB We present JPF-SE, an extension to the Java PathFinder Model Checking framework (JPF) that enables the symbolic execution of Java programs. JPF-SE uses JPF to generate and explore symbolic execution paths and it uses off-the-shelf decision procedures to manipulate numeric constraints. C1 [Anand, Saswat] Georgia Inst Technol, Coll Comp, Atlanta, GA 30332 USA. [Pasareanu, Corina S.; Visser, Willem] NASA, Ames Res Ctr, QSS, Moffett Field, CA 94035 USA. [Pasareanu, Corina S.; Visser, Willem] NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. RP Anand, S (reprint author), Georgia Inst Technol, Coll Comp, Atlanta, GA 30332 USA. EM saswat@cc.gatech.edu; pcorina@email.arc.nasa.gov; wvisser@email.arc.nasa.gov NR 9 TC 41 Z9 42 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 978-3-540-71208-4 J9 LECT NOTES COMPUT SC PY 2007 VL 4424 BP 134 EP + PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BGC46 UT WOS:000246019900010 ER PT S AU Gheorghiu, M Giannakopoulou, D Pasareanu, CS AF Gheorghiu, Mihaela Giannakopoulou, Dimitra Pasareanu, Corina S. BE Grumberg, O Huth, M TI y Refining interface alphabets for compositional verification SO TOOLS AND ALGORITHMS FOR THE CONSTRUCTION AND ANALYSIS OF SYSTEMS, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Proceedings Paper CT 13th International Conference on Tools and Algorithms for the Construction and Analysis of Systems CY MAR 24-APR 01, 2007 CL Braga, PORTUGAL ID CHECKING AB Techniques for learning automata have been adapted to automatically infer assumptions in assume-guarantee compositional verification. Learning, in this context, produces assumptions and modifies them using counterexamples obtained by model checking components separately. In this process, the interface alphabets between components, that constitute the alphabets of the assumption automata, are fixed: they include all actions through which the components communicate. This paper introduces alphabet refinement, a novel technique that extends the assumption learning process to also infer interface alphabets. The technique starts with only a subset of the interface alphabet and adds actions to it as necessary until a given property is shown to hold or to be violated in the system. Actions to be added are discovered by counterexample analysis. We show experimentally that alphabet refinement improves the current learning algorithms and makes compositional verification by learning assumptions more scalable than non-compositional verification. C1 [Gheorghiu, Mihaela] Univ Toronto, Dept Comp Sci, 100 Coll St, Toronto, ON, Canada. [Giannakopoulou, Dimitra; Pasareanu, Corina S.] NASA, Ames Res Ctr, RIACS, QSS, Moffett Field, CA 94035 USA. RP Gheorghiu, M (reprint author), Univ Toronto, Dept Comp Sci, 100 Coll St, Toronto, ON, Canada. EM mg@cs.toronto.edu; dimitra@email.arc.nasa.gov; pcorina@email.arc.nasa.gov FU MCT/Nasa Ames for a Summer Research Internship; Graduate Award from the University of Toronto FX We thank Jamie Cobleigh for providing the models Gas station and Chiron and their decompositions. Mihaela Gheorghiu acknowledges the financial support from MCT/Nasa Ames for a Summer Research Internship, and a Graduate Award from the University of Toronto. NR 25 TC 16 Z9 16 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 978-3-540-71208-4 J9 LECT NOTES COMPUT SC PY 2007 VL 4424 BP 292 EP + PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BGC46 UT WOS:000246019900021 ER PT B AU Evans, AT Park, JM Nellis, GF Klein, SA Feller, JR Salerno, L Gianchandani, YB AF Evans, Allan T. Park, Jong M. Nellis, Gregory F. Klein, Sanford A. Feller, Jeffrey R. Salerno, Louis Gianchandani, Yogesh B. GP IEEE TI A low power, microvalve-regulated drug delivery system using a si micro-spring pressurized balloon reservoir SO TRANSDUCERS '07 & EUROSENSORS XXI, DIGEST OF TECHNICAL PAPERS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 14th International Conference on Solid-State Sensors, Actuators and Microsystems/21st European Conference on Solid-State Transducers CY JUN 10-14, 2007 CL Lyon, FRANCE SP CEA, Leti, Minatec, IEEE, IEEE Electron Devices Soc, Elsevier DE drug delivery; piezoelectric; microvalve; torsion springs ID FLOW-CONTROL AB This paper reports on a drug delivery system that provides modulated delivery of liquid-phase chemicals. The device uses silicon torsion springs on a 2 x 3 cm(2) chip to pressurize a soft polymeric reservoir and regulate flow with a piezoelectricaly actuated silicon microvalve that is 1.5 x 1.5 x 1 cm(3). Using the finished device, regulated diffusion of a fluorescent dye into agar gel was demonstrated. Fluid flow out of the 500 mu L reservoir could be regulated from 10-500 mu L/min with up to 80 KPa of delivery pressure. Typical regulation consumes 0. 136 mu W of power. Analysis of the valve, reservoir springs, and a model based on pressure-enhanced diffusion are presented and are validated by experimental data. C1 [Evans, Allan T.; Park, Jong M.; Gianchandani, Yogesh B.] Univ Michigan, Dept Elect Engn & Comp Sci, Ann Arbor, MI 48109 USA. [Nellis, Gregory F.; Klein, Sanford A.] Univ Wisconsin, Dept Mech Engn, Madison, WI 53706 USA. [Feller, Jeffrey R.; Salerno, Louis] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Evans, AT (reprint author), Univ Michigan, Dept Elect Engn & Comp Sci, Ann Arbor, MI 48109 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0841-2 PY 2007 PG 2 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA BGP86 UT WOS:000249603700085 ER PT B AU Okojie, RS Tacina, R Wey, C Blaha, C AF Okojie, R. S. Tacina, R. Wey, C. Blaha, C. GP IEEE TI Micro fabrication of sic mesoscale lean direct injector array: Toward active combustion control SO TRANSDUCERS '07 & EUROSENSORS XXI, DIGEST OF TECHNICAL PAPERS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 14th International Conference on Solid-State Sensors, Actuators and Microsystems/21st European Conference on Solid-State Transducers CY JUN 10-14, 2007 CL Lyon, FRANCE SP CEA, Leti, Minatec, IEEE, IEEE Electron Devices Soc, Elsevier DE silicon carbide; injectors; MEMS AB We report the first utilization of microelectromechanical systems (MEMS) fabrication technology to implement a mesoscale fuel injector array in silicon carbide (SiC substrate material. A combination of deep reactive ion etching (DRIE), ultrasonic micromachining, silicon loss-molding, and diffusion bonding of multiple SiC substrates was applied to fabricate the first generation 7x7-4 array injector platform. Arrayed spray patterns were demonstrated in water to determine the degree of atomization prior to fuel spray and combustion analyses. The primary objectives of this effort are: a) develop the foundational SiC platform injector array technology for use in gas turbine engines, b) use such technology to decrease combustion instabilities by active control of combustion processes. C1 [Okojie, R. S.; Tacina, R.] NASA, Glenn Res Ctr, Cleveland, OH USA. [Wey, C.] ASRC Aerosp Corp, NASA Glenn Res Ctr, Cleveland, OH 44135 USA. [Blaha, C.] Jacobs Technol Inc, NASA Glenn Res Ctr, Cleveland, OH 44135 USA. RP Okojie, RS (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. EM robert.s.okojie@nasa.gov NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0841-2 PY 2007 PG 2 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA BGP86 UT WOS:000249603700605 ER PT B AU Gautier, TN Borucki, WJ Caldwell, DA Koch, DG AF Gautier, T. N. Borucki, W. J. Caldwell, D. A. Koch, D. G. BE Afonso, C Weldrake, D Henning, T TI The Kepler follow-up observation program SO Transiting Extrasolar Planets Workshop SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Transiting Extrasolar Planets Workshop CY SEP 25-28, 2006 CL Max Planck Inst Astron, Heidelberg, GERMANY HO Max Planck Inst Astron ID EXTRA-SOLAR PLANETS; SEARCH AB The Kepler mission will use a space based, 95-cm Schmidt telescope to survey 100,000 late type dwarf stars for transiting Earth-sized planets over a period of 4 years. Up to similar to 2000 such planets might be detected along with a hundred or more transiting giant planets. About 1,000 false positive planet detections, due mainly to eclipsing binary stars, will also be found. A ground based follow-up program is planned to observe all of the planet candidates found by Kepler to weed out these false positives and produce a final catalog with a reliability greater than 95%. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gautier, TN (reprint author), CALTECH, Jet Prop Lab, MS 301-450,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Caldwell, Douglas/L-7911-2014 OI Caldwell, Douglas/0000-0003-1963-9616 NR 5 TC 3 Z9 3 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-583812-34-1 J9 ASTR SOC P PY 2007 VL 366 BP 219 EP 224 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGJ12 UT WOS:000247385200039 ER PT B AU Knutson, HA Charbonneau, D Deming, D Richardson, LJ AF Knutson, H. A. Charbonneau, D. Deming, D. Richardson, L. J. BE Afonso, C Weldrake, D Henning, T TI A ground-based search for L band thermal emission from TrES-1 SO TRANSITING EXTRASOLAR PLANETS WORKSHOP SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT Transiting Extrasolar Planets Workshop CY SEP 25-28, 2006 CL Max Planck Inst Astron, Heidelberg, GERMANY HO Max Planck Inst Astron ID EXTRASOLAR PLANET; ATMOSPHERES AB Recent observations using the Spitzer Space Telescope have detected the thermal emission from several transiting planets, including TrES-1. Charbonneau et al. (2005) found that the 4.5 mu m eclipse depth for TrES-1 was smaller than expected; theoretical models predict that hot Jupiters like TrES-1 should have a strong peak in their emission at 4 mu m. We followed up this initial Spitzer measurement with spectral observations of the secondary eclipse of TrES-1 in L band using NIRI on Gemini North, which allowed us to create a bandpass centered on the predicted 4 gm peak. The simultaneous observation of a second star allows us to calibrate out time-dependent variations in the common-mode terrestrial atmospheric absorption and seeing effects. We obtained a, series of 758 spectra spanning g two secondary eclipses of TrES-1 and present the preliminary results of our analysis in this poster. C1 [Knutson, H. A.; Charbonneau, D.] Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. [Deming, D.] Goddard Space Flight Ctr, Planetary Syst Lab, Greenbelt, MD USA. [Richardson, L. J.] Goddard Space Flight Ctr, Exoplanet & Stellar Astrophys Lab, Greenbelt, MD USA. RP Knutson, HA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. FU Gemini Observatory [GN-2006A-Q-3]; National Science Foundation; NASA Postdoctoral Fellowship at NASA Goddard FX This work is based on observations obtained as part of program GN-2006A-Q-3 at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil) and CONICET (Argentina). We are grateful to Chad Trujillo and the entire Gemini team for their assistance throughout this process. H. A. K. was supported by a National Science Foundation Graduate Research Fellowship. L. J. R. was supported by a NASA Postdoctoral Fellowship at NASA Goddard. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-583812-34-1 J9 ASTR SOC P PY 2007 VL 366 BP 259 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGJ12 UT WOS:000247385200047 ER PT B AU Fortney, JJ AF Fortney, J. J. BE Afonso, C Weldrake, D Henning, T TI Hot Jupiter model atmospheres and spectra SO Transiting Extrasolar Planets Workshop SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Transiting Extrasolar Planets Workshop CY SEP 25-28, 2006 CL Max Planck Inst Astron, Heidelberg, GERMANY HO Max Planck Inst Astron ID EXTRASOLAR PLANET; HD 209458B; THERMAL STRUCTURE; GIANT PLANETS; DWARF; CHEMISTRY; EMISSION; DYNAMICS; CARBON AB The Spitzer Space Telescope has allowed observers to detect thermal flux from the atmospheres of hot Jupiters. We present model atmospheres of several of these planets and compare our computed infrared spectra to recent space-based and ground-based infrared observations. One-dimensional radiative-equilibrium models yield infrared planet-to-star flux ratios that are in general a good match with the Spitzer data published to date. We also explore spectra as a function of orbital phase for a three-dimensional dynamical atmosphere model of planet HD 209458b. The day-side temperature structure and spectra of the dynamical model is quite different than other models. Observed flux as a function of orbital phase should be very sensitive to departures from equilibrium CO/CH4 chemistry. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Fortney, JJ (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-583812-34-1 J9 ASTR SOC P PY 2007 VL 366 BP 297 EP 302 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGJ12 UT WOS:000247385200054 ER PT B AU Borucki, WJ Koch, DG Lissauer, J Basri, G Brown, T Caldwell, DA Jenkins, JM Caldwell, JJ Christensen-Dalsgaard, J Cochran, WD Dunham, EW Gautier, TN Geary, JC Latham, D Sasselov, D Gilliland, RL Howell, S Monet, DG Batalha, N AF Borucki, W. J. Koch, D. G. Lissauer, J. Basri, G. Brown, T. Caldwell, D. A. Jenkins, J. M. Caldwell, J. J. Christensen-Dalsgaard, J. Cochran, W. D. Dunham, E. W. Gautier, T. N. Geary, J. C. Latham, D. Sasselov, D. Gilliland, R. L. Howell, S. Monet, D. G. Batalha, N. BE Afonso, C Weldrake, D Henning, T TI KEPLER mission status SO Transiting Extrasolar Planets Workshop SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Transiting Extrasolar Planets Workshop CY SEP 25-28, 2006 CL Max Planck Inst Astron, Heidelberg, GERMANY HO Max Planck Inst Astron ID PLANETARY SYSTEMS AB Kepler is a Discovery-class mission designed to determine the frequency of Earth-size and smaller planets in and near the habitable zone (HZ) of dwarf stars. The instrument consists of a 0.95-m aperture photometer capable of doing high precision photometry of more than 100,000 late-type main sequence stars to search for patterns of transits. 'Multi-band ground-based observation of over 2 million stars is currently underway to estimate the stellar parameters and to choose appropriate targets. The association of planet size and occurrence frequency with stellar mass and metallicity will be investigated. At the end of the four year mission, several hundred terrestrial planets (i.e., planets up to twice the diameter of the Earth) should be discovered with periods between one day and 400 days if such planets are common. As many as 100 Earth-size planets in the HZ could be discovered. A null result would imply that terrestrial planets are rare. The scientific community is invited to participate through the Participating Scientist, Guest Observer and Data Analysis programs. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Borucki, WJ (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Caldwell, Douglas/L-7911-2014 OI Caldwell, Douglas/0000-0003-1963-9616 NR 12 TC 31 Z9 31 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 978-1-583812-34-1 J9 ASTR SOC P PY 2007 VL 366 BP 309 EP 319 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGJ12 UT WOS:000247385200056 ER PT S AU Liu, Y Cukic, B Schumann, J Jiang, M AF Liu, Yan Cukic, Bojan Schumann, Johann Jiang, Michael BE Chen, K Wang, L TI Performance analysis of Dynamic Cell Structures SO TRENDS IN NEURAL COMPUTATION SE Studies in Computational Intelligence LA English DT Proceedings Paper CT 1st International Conference on Natural Computation (ICNC 2005) CY AUG 27-29, 2005 CL Changsha, PEOPLES R CHINA SP Xiangtang Univ, IEEE Circuits & Syst Soc, IEEE Computat Intelligence Soc, IEEE Control Syst Soc, Int Neural Network Soc, European Neural Network Soc, Chinese Assoc Artificial Intelligence, Japanese Neural Network Soc, Int Fuzzy Syst Assoc, Asia Pacific Neural Network Assembly, Fuzzy Math & Syst Assoc China, Hunan Comp Federat DE Dynamic Cell Structures; validity index; sensitivity analysis; performance estimation; confidence measures; neural networks ID NOVELTY DETECTION; NETWORKS; MAP AB As a special type of Self-Organizing Maps (SOM), the Dynamic Cell Structures (DCS) network has topology-preserving adaptive learning capabilities that can, in theory; respond and learn to abstract from a wide variety of complex data manifolds. However, the highly complex learning algorithm and non-linearity behind the dynamic learning pose serious challenge to validating the performance of DCS and impede its spread in control applications; safety-critical systems in particular. In this paper, we analyze the performance of DCS network by providing sensitivity analysis on its structure and confidence measures on its predictions. We evaluate how the quality of each parameter of the network (e.g., weight) influences the output of the network by defining a metric for parameter sensitivity for DCS network. We present the validity index (VI), an estimated confidence associated with each DCS output, as a reliability-like measure of the network's prediction performance. Our experiments using artificial data and a case study oil a flight control application demonstrate that our analysis effectively measures the network performance and provides validation inferences in a real-time manner. C1 [Liu, Yan; Jiang, Michael] Motorola Inc, Motorola Labs, Schaumburg, IL 60196 USA. [Cukic, Bojan] West Virginia Univ, Lane Dept Comp Sci & Elect Engn, Morgantown, WV 26505 USA. [Schumann, Johann] NASA Ames, RIACS, Moffett Field, CA 94035 USA. RP Liu, Y (reprint author), Motorola Inc, Motorola Labs, Schaumburg, IL 60196 USA. EM yanliu@motorola.com; cukic@csee.wvu.edu; schumann@email.arc.nasa.gov; Michael.Jiang@motorola.com NR 38 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 1860-949X BN 3-540-36121-9 J9 STUD COMPUT INTELL PY 2007 VL 35 BP 367 EP + PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BFN80 UT WOS:000243355000015 ER PT J AU DellaCorte, C AF DellaCorte, Christopher TI New year brings positive changes SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM cdellacorte@stle.org NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1545-858X J9 TRIBOL LUBR TECHNOL JI Tribol. Lubr. Technol. PD JAN PY 2007 VL 63 IS 1 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 123BM UT WOS:000243271300002 ER PT S AU Smith, EJ Zhou, X AF Smith, Edward. J. Zhou, Xiaoyan BE Shaikh, D Zank, GP TI Slow mode waves in the heliospheric plasma sheet SO TURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 6th Annual International Astrophysics Conference CY MAR 16-22, 2007 CL Oahu, HI SP IGPP UCR, Los Alamos Natl Lab, UCLA IGPP, Solana Sci DE slow mode waves; Heliospheric plasma sheet ID SOLAR-WIND; CORONAL STREAMERS AB We report the results of a search for waves/turbulence in the Heliospheric Plasma Sheet (HPS) surrounding the Heliospheric Current Sheet (HCS). The HPS is treated as a distinctive heliospheric structure distinguished by relatively high Beta, slow speed plasma. The data used in the investigation are from a previously published study of the thicknesses of the HPS and HCS that were obtained in January to May 2004 when Ulysses was near aphelion at 5 AU. The advantage of using these data is that the HPS is thicker at large radial distances and the spacecraft spends longer intervals inside the plasma sheet. From the study of the magnetic field and solar wind velocity components, we conclude that, if Alfven waves are present, they are weak and are dominated by variations in the field magnitude, B, and solar wind density, N-p, that are anti-correlated. To distinguish between slow mode waves, Pressure Balance Structures (PBS) and Mirror Modes, correlations between magnetic, kinetic and total static pressures (p(B), p(K) and p(T)) are studied. The slopes of the P-B - P-K, and p(K) - p(T) regression lines are qualitatively consistent with slow mode waves and rule out the other possibilities. In principle, the slopes are measures of the wave speed relative to the Alfven and sound speeds and imply the direction of propagation with respect to the ambient field. C1 [Smith, Edward. J.; Zhou, Xiaoyan] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RP Smith, EJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0443-4 J9 AIP CONF PROC PY 2007 VL 932 BP 144 EP + PG 3 WC Astronomy & Astrophysics; Physics, Fluids & Plasmas SC Astronomy & Astrophysics; Physics GA BGX51 UT WOS:000251152400020 ER PT S AU Shebalin, JV AF Shebalin, John V. BE Shaikh, D Zank, GP TI Symmetry, statistics and structure in MHD turbulence SO TURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 6th Annual International Astrophysics Conference CY MAR 16-22, 2007 CL Oahu, HI SP IGPP UCR, Los Alamos Natl Lab, UCLA IGPP, Solana Sci DE MHD; turbulence; statistical mechanics; magnetic dynamo ID IDEAL MAGNETOHYDRODYNAMIC TURBULENCE; MEAN MAGNETIC-FIELD; HOMOGENEOUS TURBULENCE; ISOTROPIC TURBULENCE; BROKEN ERGODICITY AB It is known that symmetries inherent in the statistical theory of ideal (i.e., non-dissipative) magnetohydrodynamic (MHD) turbulence are broken dynamically to produce coherent structure. Previous numerical investigations are extended to study decaying MHD turbulence. Here, we find that coherent structure also arises and persists in the presence of dissipation. Thus, the magnetic dynamo may be due to a dynamically broken symmetry that is inherent to MHD turbulence. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Shebalin, JV (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0443-4 J9 AIP CONF PROC PY 2007 VL 932 BP 209 EP 214 PG 6 WC Astronomy & Astrophysics; Physics, Fluids & Plasmas SC Astronomy & Astrophysics; Physics GA BGX51 UT WOS:000251152400029 ER PT S AU Narita, Y Glassmeier, KH Goldstein, ML Treumann, RA AF Narita, Yasuhito Glassmeier, Karl-Heinz Goldstein, Melvyn L. Treumann, Rudolf A. BE Shaikh, D Zank, GP TI Cluster observations of shock-turbulence interactions SO TURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 6th Annual International Astrophysics Conference CY MAR 16-22, 2007 CL Oahu, HI SP IGPP UCR, Los Alamos Natl Lab, UCLA IGPP, Solana Sci DE wave number spectra; collisionless shock ID SOLAR-WIND; FLUCTUATIONS AB Measurements of wave number spectra for two-dimensional, Alfvenic, and compressible fluctuations are presented in the solar wind and the regions related to the collisionless shocks. The spectra are determined from the four-point magnetometer data recorded by the Cluster spacecraft. The solar wind exhibits spectral curves characteristic of the inertial and the dissipation ranges of turbulence and appears to be dominated by two-dimensional turbulence. The fluctuations become more intense and the spectra are modified as the solar wind interacts with the bow shock, suggesting that the plasma instabilities are operating in the foreshock and the magnetosheath. C1 [Narita, Yasuhito] Tech Univ Carolo Wilhelmina Braunschweig, Inst Geophys & Extraterr Phys, Mendelssohnstr 3, D-38106 Braunschweig, Germany. [Glassmeier, Karl-Heinz] Inst Geophys & Extraterr Phys, D-38106 Braunschweig, Germany. [Goldstein, Melvyn L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Treumann, Rudolf A.] Univ Munich, Dept Geosci Geophy Sect, D-80333 Munich, Germany. RP Narita, Y (reprint author), Tech Univ Carolo Wilhelmina Braunschweig, Inst Geophys & Extraterr Phys, Mendelssohnstr 3, D-38106 Braunschweig, Germany. RI Goldstein, Melvyn/B-1724-2008 FU Federal Ministry for Education and Research; German Aerospace Center [50OC0103] FX This work was financially supported by the Federal Ministry for Education and Research (Bundesministerium fiir Bildung und Forschung) and the German Aerospace Center (Deutsches Zentrum fiir Luft- und Raumfahrt) under contract 50OC0103. We thank H. Reme and I. Dandouras for providing ion data of Cluster. NR 10 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0443-4 J9 AIP CONF PROC PY 2007 VL 932 BP 215 EP + PG 2 WC Astronomy & Astrophysics; Physics, Fluids & Plasmas SC Astronomy & Astrophysics; Physics GA BGX51 UT WOS:000251152400030 ER PT S AU Ng, CK AF Ng, Chee K. BE Shaikh, D Zank, GP TI Turbulence evolution and shock acceleration of solar energetic particles SO TURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 6th Annual International Astrophysics Conference CY MAR 16-22, 2007 CL Oahu, HI SP IGPP UCR, Los Alamos Natl Lab, UCLA IGPP, Solana Sci DE coronal shock acceleration; solar energetic particles; self-excited plasma wave ID HYDROMAGNETIC WAVE EXCITATION; EARTHS BOW SHOCK; ION-ACCELERATION; ALFVEN WAVES; TRANSMISSION; FRONTS; MODEL AB We model the effects of self-excitation/damping and shock transmission of Alfven waves on solar-energetic-particle (SEP) acceleration at a coronal-mass-ejection (CME) driven parallel shock. SEP-excited outward upstream waves speedily bootstrap acceleration. Shock transmission further raises the SEP-excited wave intensities at high wavenumbers but lowers them at low wavenumbers through wavenumber shift. Downstream, SEP excitation of inward waves and damping of outward waves tend to slow acceleration. Nevertheless, > 2000 km/s parallel shocks at similar to 3.5 solar radii can accelerate SEPs to 100 MeV in < 5 minutes. C1 NASA, Goddard Space Flight Ctr, Washington, DC 20546 USA. RP Ng, CK (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Washington, DC 20546 USA. NR 16 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0443-4 J9 AIP CONF PROC PY 2007 VL 932 BP 271 EP 276 PG 6 WC Astronomy & Astrophysics; Physics, Fluids & Plasmas SC Astronomy & Astrophysics; Physics GA BGX51 UT WOS:000251152400037 ER PT S AU Mewaldt, RA Cohen, CMS Haggerty, DK Mason, GM Looper, ML von Rosenvinge, TT Wiedenbeck, ME AF Mewaldt, R. A. Cohen, C. M. S. Haggerty, D. K. Mason, G. M. Looper, M. L. von Rosenvinge, T. T. Wiedenbeck, M. E. BE Shaikh, D Zank, GP TI Radiation risks from large solar energetic particle events SO TURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 6th Annual International Astrophysics Conference CY MAR 16-22, 2007 CL Oahu, HI SP IGPP UCR, Los Alamos Natl Lab, UCLA IGPP, Solana Sci DE solar energetic particles; particle acceleration; coronal mass ejections; radiation risks ID CORONAL MASS EJECTIONS; COSMIC-RAY EVENTS; ACCELERATION; INTENSITIES AB Solar energetic particles (SEPs) constitute a radiation hazard to both humans and hardware in space. Over the past few years there have been significant advances in our knowledge of the composition and energy spectra of SEP events, leading to new insights into the conditions that contribute to the largest events. This paper summarizes the energy spectra and frequency of large SEP events, and discusses the interplanetary conditions that affect the intensity of the largest events. C1 [Mewaldt, R. A.; Cohen, C. M. S.] CALTECH, Pasadena, CA 91125 USA. [Haggerty, D. K.; Mason, G. M.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. [Looper, M. L.] Aerosp Corp, Los Angeles, CA 90009 USA. [von Rosenvinge, T. T.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Wiedenbeck, M. E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mewaldt, RA (reprint author), CALTECH, Pasadena, CA 91125 USA. FU NASA [NAS5-0313I, NAG5-12929, NNG04GB55G, NNX06AC2IG] FX This work was supported by NASA under NAS5-0313I ,NAG5-12929, NNG04GB55G and NNX06AC2IG. We appreciate the use of GOES data provided by NOAA and thank the organizers for an excellent conference. NR 28 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0443-4 J9 AIP CONF PROC PY 2007 VL 932 BP 277 EP + PG 2 WC Astronomy & Astrophysics; Physics, Fluids & Plasmas SC Astronomy & Astrophysics; Physics GA BGX51 UT WOS:000251152400038 ER PT S AU Rappazzo, AF Velli, M Einaudi, G AF Rappazzo, A. F. Velli, M. Einaudi, G. BE Shaikh, D Zank, GP TI Heating of coronal loops: weak MHD turbulence and scaling laws SO TURBULENCE AND NONLINEAR PROCESSES IN ASTROPHYSICAL PLASMAS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 6th Annual International Astrophysics Conference CY MAR 16-22, 2007 CL Oahu, HI SP IGPP UCR, Los Alamos Natl Lab, UCLA IGPP, Solana Sci DE MHD; sun : corona; sun : magnetic fields; turbulence ID MAGNETOHYDRODYNAMIC TURBULENCE; SOLAR CORONA; STATISTICS; NANOFLARES AB To understand the nonlinear dynamics of the Parker scenario for coronal heating, longtime high-resolution simulations of the dynamics of a coronal loop in cartesian geometry are carried out. A loop is modeled as a box extended along the direction of the strong magnetic field B-0 in which the system is embedded. At the top and bottom plates, which represent the photosphere, velocity fields mimicking photospheric motions are imposed. We show that the nonlinear dynamics is described by different regimes of MHD anisotropic turbulence, with spectra characterized by intertial range power laws whose indexes range from Kolmogorov-like values (similar to 5/3) up to similar to 3. We briefly describe the beating for coronal heating rates. C1 [Rappazzo, A. F.; Velli, M.] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. [Velli, M.] Univ Florence, Dipartimento Astron & Sci Spazio, I-50125 Florence, Italy. [Einaudi, G.] Univ Pisa, Dipartimento Fis E Fermi, I-56127 Pisa, Italy. RP Rappazzo, AF (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. FU NASA Postdoctoral Program; NASA LWS TRT; SRT FX A.F.R. and M.V. thank the IPAM program "Grand Challenge Problems in Computationa lAstrophysics "at UCLA. A.F.R. is supported by the NASA Postdoctoral Program,M.V.is supported by NASA LWS TR&T and SR&T. NR 21 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0443-4 J9 AIP CONF PROC PY 2007 VL 932 BP 342 EP + PG 2 WC Astronomy & Astrophysics; Physics, Fluids & Plasmas SC Astronomy & Astrophysics; Physics GA BGX51 UT WOS:000251152400047 ER PT S AU Rankin, AL Huertas, A Matthies, LH AF Rankin, Arturo L. Huertas, Andres Matthies, Larry H. BE Gerhart, GR Gage, DW Shoemaker, CM TI Nighttime negative obstacle detection for off-road autonomous navigation - art. no. 656103 SO Unmanned Systems Technology IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unmanned Systems Technology IX CY APR 09-12, 2007 CL Orlando, FL SP SPIE DE negative obstacle detection; stereo vision; perception; autonomous navigation; thermal infrared AB Detecting negative obstacles (ditches, holes, wadis, and other depressions) is one of the most difficult problems in perception for unmanned ground vehicle (UGV) off-road autonomous navigation. One reason for this is that the width of the visible portion of a negative obstacle may only span a few pixels at the stopping distance for vehicle speeds UGV programs aspire to operate at (up to 50kph). The problem can be further compounded when negative obstacles are obscured by vegetation or when negative obstacles are embedded in undulating terrain. Because of the variety of appearances of negative obstacles, a multi-cue detection approach is desired. In previous nighttime negative obstacle detection work, we have described combining geometry based cues from stereo range data and a thermal signature based cue from thermal infrared imagery. Thermal signature is a powerful cue during the night since the interiors of negative obstacles generally remain warmer than surrounding terrain throughout the night. In this paper, we further couple the thermal signature based cue and geometry based cues from stereo range data for nighttime negative obstacle detection. Edge detection is used to generate closed contour candidate negative obstacle regions that are geometrically filtered to determine if they lie within the ground plane. Cues for negative obstacles from thermal signature, geometry-based analysis of range images, and geometry-based analysis of terrain maps are fused. The focus of this work is to increase the range at which UGVs can reliably detect negative obstacles on cross-country terrain, thereby increasing the speed at which UGVs can safely operate. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Rankin, AL (reprint author), CALTECH, Jet Propuls Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 14 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6683-9 J9 P SOC PHOTO-OPT INS PY 2007 VL 6561 BP 56103 EP 56103 AR 656103 DI 10.1117/12.720513 PG 12 WC Robotics; Remote Sensing; Imaging Science & Photographic Technology SC Robotics; Remote Sensing; Imaging Science & Photographic Technology GA BGL74 UT WOS:000248227700002 ER PT S AU Feinberg, LD Dean, BH Aronstein, DL Bowers, CW Hayden, W Lyon, RG Shiri, R Smith, JS Acton, DS Carey, L Contos, A Sabatke, E Schwenker, J Shields, D Towell, T Shi, F Meza, L AF Feinberg, Lee D. Dean, Bruce H. Aronstein, David L. Bowers, Charles W. Hayden, William Lyon, Richard G. Shiri, Ron Smith, J. Scott Acton, D. Scott Carey, Larkin Contos, Adam Sabatke, Erin Schwenker, John Shields, Duncan Towell, Tim Shi, Fang Meza, Luis BE MacEwen, HA Breckinridge, JB TI TRL-6 for JWST wavefront sensing and control - art. no. 668708 SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE technology readiness level; TRL-6; wave front sensing control; active optics; JWST; space telescope; segmented mirror; phase retrieval ID GENERATION SPACE TELESCOPE; PHASE-RETRIEVAL ALGORITHMS; DIFFRACTION PLANE PICTURES; EXPERIMENTAL-VERIFICATION; IMAGE-RECONSTRUCTION; OPTICAL DESIGN; KECK-TELESCOPE; ERROR; BATC; PERFORMANCE AB NASA's Technology Readiness Level (TRL)-6 is documented for the James Webb Space Telescope (JWST) Wavefront Sensing and Control (WFSC) subsystem. The WFSC subsystem is needed to align the Optical Telescope Element (OTE) after all deployments have occurred, and achieves that requirement through a robust commissioning sequence consisting of unique commissioning algorithms, all of which are part of the WFSC algorithm suite. This paper identifies the technology need, algorithm heritage, describes the finished TRL-6 design platform, and summarizes the TRL-6 test results and compliance. Additionally, the performance requirements needed to satisfy JWST science goals as well as the criterion that relate to the TRL-6 Testbed Telescope (TBT) performance requirements are discussed. C1 [Feinberg, Lee D.; Dean, Bruce H.; Aronstein, David L.; Bowers, Charles W.; Hayden, William; Lyon, Richard G.; Shiri, Ron; Smith, J. Scott] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Feinberg, LD (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 62 TC 8 Z9 8 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP 68708 EP 68708 DI 10.1117/12.736059 PG 24 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000006 ER PT S AU Li, MJ Adachi, T Allen, CA Babu, SR Bajikar, S Beamesderfer, MA Bradley, R Costen, NP Denis, K Ewin, AJ Franz, D Hess, L Hu, R Jackson, K Jhabvala, MD Kelly, D King, T Kletetschka, G Kutyrev, AS Lynch, BA Meyer, SE Miller, T Moseley, SH Mikula, V Mott, B Oh, L Pontius, JT Rapchun, DA Ray, C Schwinger, S Shu, PK Silverberg, R Smith, WW Snodgrass, S Sohl, D Sparr, L Steptoe-Jackson, R Thate, RJ Wang, F Wang, L Zheng, Y Zincke, C AF Li, M. J. Adachi, T. Allen, C. A. Babu, S. R. Bajikar, S. Beamesderfer, M. A. Bradley, R. Costen, N. P. Denis, Kevin Ewin, A. J. Franz, D. Hess, L. Hu, R. Jackson, K. Jhabvala, M. D. Kelly, D. King, T. Kletetschka, G. Kutyrev, A. S. Lynch, B. A. Meyer, S. E. Miller, T. Moseley, S. H. Mikula, V. Mott, B. Oh, L. Pontius, J. T. Rapchun, D. A. Ray, C. Schwinger, S. Shu, P. K. Silverberg, R. Smith, W. W. Snodgrass, S. Sohl, D. Sparr, L. Steptoe-Jackson, R. Thate, R. J. Wang, F. Wang, L. Zheng, Y. Zincke, C. BE MacEwen, HA Breckinridge, JB TI Microshutter array system for James Webb Space Telescope - art. no. 668709 SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE micro-optics; near infrared; space telescope; indium bump bonding; packaging; microshutter; MEMS; DRIE AB We have developed microshutter array systems at NASA Goddard Space Flight Center for use as multi-object aperture arrays for a Near-Infrared Spectrometer (NIRSpec) instrument. The instrument will be carried on the James Webb Space Telescope (JWST), the next generation of space telescope, after the Hubble Space Telescope retires. The microshutter arrays (MSAs) are designed for the selective transmission of light from objected galaxies in space with high efficiency and high contrast. Arrays are close-packed silicon nitride membranes with a pixel size close to 100x200 mu m. Individual shutters are patterned with a torsion flexure permitting shutters to open 90 degrees with minimized stress concentration. In order to enhance optical contrast, light shields are made on each shutter to prevent light leak. Shutters are actuated magnetically, latched and addressed electrostatically. The shutter arrays are fabricated using MEMS bulk-micromachining and packaged utilizing a novel single-sided indium flip-chip bonding technology. The MSA flight system consists of a mosaic of 2 x 2 format of four fully addressable 365 x 171 arrays. The system will be placed in the JWST optical path at the focal plane of NIRSpec detectors. MSAs that we fabricated passed a series of qualification tests for flight capabilities. We are in the process of making final flight-qualified MSA systems for the JWST mission. C1 [Li, M. J.; Allen, C. A.; Babu, S. R.; Beamesderfer, M. A.; Ewin, A. J.; Jhabvala, M. D.; King, T.; Meyer, S. E.; Moseley, S. H.; Mott, B.; Pontius, J. T.; Schwinger, S.; Shu, P. K.; Silverberg, R.; Sohl, D.; Sparr, L.; Steptoe-Jackson, R.; Thate, R. J.; Zheng, Y.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Li, MJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Kletetschka, Gunther/C-9996-2011 OI Kletetschka, Gunther/0000-0002-0645-9037 NR 15 TC 5 Z9 5 U1 0 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP 68709 EP 68709 DI 10.1117/12.734152 PG 13 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000007 ER PT S AU Sidick, E Morgan, RM Green, JJ Ohara, CM Redding, DC AF Sidick, Erkin Morgan, Rhonda M. Green, Joseph J. Ohara, Catherine M. Redding, David C. BE MacEwen, HA Breckinridge, JB TI Adaptive cross-correlation algorithm and experiment of extended scene Shack-Hartmann wavefront sensing - art. no. 668710 SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE adaptive optics; Shack-Hartmann sensor; extended scene; remote imaging; wave-front sensing and control AB We have developed a new, adaptive cross-correlation (ACC) algorithm to estimate with high accuracy the shift as large as several pixels in two extended-scene images captured by a Shack-Hartmann wavefront sensor (SH-WFS). It determines the positions of all extended-scene image cells relative to a reference cell using an FFT-based iterative image-shifting algorithm. It works with both point-source spot images as well as extended scene images. We have also set up a testbed for extended-scene SH-WFS, and tested the ACC algorithm with the measured data of both point-source and extended-scene images. In this paper we describe our algorithm and present our experimental results. C1 [Sidick, Erkin; Morgan, Rhonda M.; Green, Joseph J.; Ohara, Catherine M.; Redding, David C.] CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Sidick, E (reprint author), CALTECH, Jet Propuls Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 2 Z9 2 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP 68710 EP 68710 DI 10.1117/12.735030 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000032 ER PT S AU Smith, JS Aronstein, DL Dean, BH Acton, DS AF Smith, J. Scott Aronstein, David L. Dean, Bruce H. Acton, D. Scott BE MacEwen, HA Breckinridge, JB TI Co-adding techniques for image-based wavefront sensing for segmented-mirror telescopes - art. no. 668711 SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE phase retrieval; James Webb Space Telescope (JWST); wavefront sensing; segmented ID DIFFRACTION PLANE PICTURES; PHASE AB Image-based wavefront sensing algorithms are being used to characterize the optical performance for a variety of current and planned astronomical telescopes. Phase retrieval recovers the optical wavefront that correlates to a series of diversity-defocused point-spread functions (PSFs), where multiple frames can be acquired at each defocus setting. Multiple frames of data can be co-added in different ways; two extremes are in "image-plane space," to average the frames for each defocused PSF and use phase retrieval once on the averaged images, or in "pupil-plane space," to use phase retrieval on each PSF frame individually and average the resulting wavefronts. The choice of co-add methodology is particularly noteworthy for segmented-mirror telescopes that are subject to noise that causes uncorrelated motions between groups of segments. Using models and data from the James Webb Space Telescope (JWST) Testbed Telescope (TBT), we show how different sources of noise (uncorrelated segment jitter, turbulence, and common-mode noise) and different parts of the optical wavefront, segment and global aberrations, contribute to choosing the co-add method. Of particular interest, segment piston is more accurately recovered in "image-plane space" co-adding, while segment tip/tilt is recovered in "pupil-plane space" co-adding. C1 [Smith, J. Scott; Aronstein, David L.; Dean, Bruce H.] NASA, Goddard Space Flight Ctr, Wavefront Sensing & Control Grp, Opt Branch, Greenbelt, MD 20771 USA. RP Smith, JS (reprint author), NASA, Goddard Space Flight Ctr, Wavefront Sensing & Control Grp, Opt Branch, Code 551, Greenbelt, MD 20771 USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP 68711 EP 68711 DI 10.1117/12.736401 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000033 ER PT S AU Heap, SR AF Heap, Sara R. BE MacEwen, HA Breckinridge, JB TI The terrestrial planet finder-occulter (TPF-O) science program - art. no. 668713 SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE terrestrial planet finder; TPF-O; occulter; science program; exoplanet spectra AB We describe the TPF-O science program composed of interleaved imagery and spectroscopy of planets in the habitable zones of nearby stars. We give the rationale for the science program and argue that TPF-O offers the best approach to achieving the original goals set for the Terrestrial Planet Finder. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Heap, SR (reprint author), NASA, Goddard Space Flight Ctr, Code 667, Greenbelt, MD 20771 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP 68713 EP 68713 DI 10.1117/12.734078 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000035 ER PT S AU Purves, LR AF Purves, Lloyd R. BE MacEwen, HA Breckinridge, JB TI Conceptual design of the TPF-O SC buses - art. no. 668718 SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE terrestrial planet finder; TPF-O; occulter; space telescope; spacecraft bus AB The Terrestrial Planet Finder - Occulter (TPF-O) mission has two Spacecraft (SC) buses, one for a formation-flying occulter and the other for a space telescope. These buses supply the utilities (support structures, propulsion, attitude control, power, communications, etc) required by the payloads: a deployable shade for the occulter and a telescope with instruments for the space telescope. Significant requirements for the occulter SC bus are to provide the large delta V required for the slewing maneuvers of the occulter and communications for formation flying. The TPF-O telescope SC bus shares some key features of the one for the Hubble Space Telescope (HST) in that both support space telescopes designed to observe in the visible to near infrared range of wavelengths with comparable primary mirror apertures (2.4 in for HST, 2.4 - 4.0 in for TPF-O). Significant differences from HST are that 1) the TPF-O telescope is expected to have a Wide Field Camera (WFC) that will have a Field of View (FOV) large enough to provide fine guidance, 2) TPF-O is designed to operate in an orbit around the Suri-Earth Lagrange 2 (SEL2) point which requires TPF-O (unlike HST) to have a propulsion system, and 3) the velocity required for reaching SEL2 and the limited capabilities of affordable launch vehicles require both TPF-O elements to have compact, low-mass designs. Additionally, it is possible that TPF-O may utilize a modular design derived from that of HST to allow robotic servicing in the SEL2 orbit. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Purves, LR (reprint author), NASA, Goddard Space Flight Ctr, Code 592, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP 68718 EP 68718 DI 10.1117/12.732597 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000039 ER PT S AU Lyon, RG Heap, S Lo, A Cash, W Starkman, GD Vanderbei, RJ Kasdin, NJ Copi, CJ AF Lyon, Richard G. Heap, Sally Lo, Amy Cash, Webster Starkman, Glenn D. Vanderbei, Robert J. Kasdin, N. Jeremy Copi, Craig J. BE MacEwen, HA Breckinridge, JB TI Externally occulted terrestrial planet finder coronagraph: Simulations and sensitivities - art. no. 668719 SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE terrestrial planets; coronagraphy; occulters; starshade; exo-solar; Fourier optics; beam propagation ID SPACE TELESCOPE; STARS AB A multitude of coronagraphic techniques for the space-based direct detection and characterization of exo-solar terrestrial planets are actively being pursued by the astronomical community. Typical coronagraphs have internal shaped focal plane and/or pupil plane occulting masks which block and/or diffract starlight thereby increasing the planet's contrast with respect to its parent star. Past studies have shown that any internal technique is limited by the ability to sense and control amplitude, phase (wavefront) and polarization to exquisite levels - necessitating stressing optical requirements. An alternative and promising technique is to place a starshade, i.e. external occulter, at some distance in front of the telescope. This starshade suppresses most of the starlight before entering the telescope - relaxing optical requirements to that of a more conventional telescope. While an old technique it has been recently been advanced by the recognition that circularly symmetric graded apodizers can be well approximated by shaped binary occulting masks. Indeed optimal shapes have been designed that can achieve smaller inner working angles than conventional coronagraphs and yet have high effective throughput allowing smaller aperture telescopes to achieve the same coronagraphic resolution and similar sensitivity as larger ones. Herein we report on our ongoing modeling, simulation and optimization of external occulters and show sensitivity results with respect to number and shape errors of petals, spectral passband, accuracy of Fresnel propagation, and show results for both filled and segmented aperture telescopes and discuss acquisition and sensing of the occulter's location relative to the telescope. C1 [Lyon, Richard G.; Heap, Sally] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lyon, RG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 12 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP 68719 EP 68719 DI 10.1117/12.731755 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000040 ER PT S AU Hyde, TT Leisawitz, DT Di Pietro, DA Rinehart, SA AF Hyde, T. Tupper Leisawitz, David T. Di Pietro, David A. Rinehart, Stephen A. BE MacEwen, HA Breckinridge, JB TI System engineering the Space Infrared Interferometric Telescope (SPIRIT) - art. no. 66870A SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE SPIRIT; infrared/IR; interferometry; telescope; system engineering; error budget AB The Space Infrared Interferometric Telescope (SPIRIT) was designed to accomplish three scientific objectives: (1) learn how planetary systems form from protostellar disks and how they acquire their inhomogeneous chemical composition; (2) characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of different types form; and (3) learn how high-redshift galaxies formed and merged to form the present-day population of galaxies. SPIRIT will accomplish these objectives through infrared observations with a two aperture interferometric instrument. This paper gives an overview of SPIRIT design and operation, and how the three design cycle concept study was completed. The error budget for several key performance values allocates tolerances to all contributing factors, and a performance model of the spacecraft plus instrument system demonstrates meeting those allocations with margin. C1 [Hyde, T. Tupper; Leisawitz, David T.; Di Pietro, David A.; Rinehart, Stephen A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hyde, TT (reprint author), NASA, Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP A6870 EP A6870 DI 10.1117/12.735143 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000008 ER PT S AU Leviton, DB Cash, WC Gleason, B Kaiser, MJ Levine, SA Lo, AS Schindhelm, E Shipley, AF AF Leviton, Douglas B. Cash, Webster C. Gleason, Brian Kaiser, Michael J. Levine, Sarah A. Lo, Amy S. Schindhelm, Eric Shipley, Ann F. BE MacEwen, HA Breckinridge, JB TI White light demonstration of one hundred parts per billion irradiance suppression in air by new starshade occulters - art. no. 66871B SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE starshade; occulter; irradiance suppression; New Worlds Observer; extra-solar planets; exo-planets AB A new mission concept for direct imaging of exo-solar planets called New Worlds Observer (NWO) has been proposed. It involves flying a meter-class space telescope in formation with a newly-conceived, specially-shaped, deployable star-occulting shade several meters across at a separation of some tens of thousands of kilometers. The telescope would make its observations from behind the starshade in a volume of high suppression of incident irradiance from the star around which planets orbit. For an efficacious mission, the required level of irradiance suppression by the starshade is of order 0.1 to 10 parts per billion in broadband light. We discuss an experiment to accurately measure the irradiance suppression ratio at the null position behind candidate starshade forms to these levels. We also present results of broadband measurements which demonstrated suppression levels of less than 100 parts per billion in air using the Sun as a light source. A simulated spatial irradiance distribution surrounding the null from an analytical model developed for starshades is compared with a photograph of actual irradiance captured in situ behind a candidate starshade. C1 [Leviton, Douglas B.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leviton, DB (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 TC 7 Z9 7 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP B6871 EP B6871 DI 10.1117/12.742927 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000042 ER PT S AU Wilson, ME Leisawitz, D Martino, AJ Rinehart, S Crooke, J Tveekrem, J Budinoff, J Hyde, T AF Wilson, Mark E. Leisawitz, David Martino, Anthony J. Rinehart, Stephen Crooke, Julie Tveekrem, June Budinoff, Jason Hyde, Tupper BE MacEwen, HA Breckinridge, JB TI The Space Infrared Interferometric Telescope (SPIRIT): Optical system design considerations - art. no. 66870B SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE SPIRIT; infrared/IR; interferometry; telescope; optical design AB The Space Infrared Interferometric Telescope (SPIRIT) was designed to accomplish three scientific objectives: (1) learn how planetary systems form from protostellar disks and how they acquire their inhomogeneous chemical composition; (2) characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of different types form; and (3) learn how high-redshift galaxies formed and merged to form the present-day population of galaxies. SPIRIT will accomplish these objectives through infrared observations with a two aperture interferometric instrument. This paper gives an overview into the optical system design, including the design form, the metrology systems used for control, stray light, and optical testing. C1 [Wilson, Mark E.; Leisawitz, David; Martino, Anthony J.; Rinehart, Stephen; Crooke, Julie; Tveekrem, June; Budinoff, Jason; Hyde, Tupper] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wilson, ME (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt Rd, Greenbelt, MD 20771 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP B6870 EP B6870 DI 10.1117/12.738562 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000009 ER PT S AU Budinoff, JG Leisawitz, D Taylor, B Jones, D AF Budinoff, Jason G. Leisawitz, David Taylor, Buddy Jones, Drew BE MacEwen, HA Breckinridge, JB TI Mechanical design of the Space Infrared Interferometric Telescope (SPIRIT) - art. no. 66870C SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE SPIRIT; instrument structures; mechanisms; optomechanics AB The Space Infrared Interferometric Telescope (SPIRIT), a candidate NASA Origins Probe mission, is a cryogenic 6-36m variable-baseline imaging interferometer operating at 25 - 400 mu m. SPIRIT utilizes dual, meter-class, telescopes which translate along opposed deployable booms. The collimated beams from the telescopes are combined in a central instrument module operating at 4K and lower. Mission-enabling mechanisms include the large, optical delay line scan mechanism, the afocal collector telescope trolley drives, and the boom deployment mechanisms. This paper provides an over-view of the mechanical aspects of the conceptual design created to meet the challenging instrument requirements. C1 [Budinoff, Jason G.; Leisawitz, David; Taylor, Buddy; Jones, Drew] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Budinoff, JG (reprint author), NASA, Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP C6870 EP C6870 DI 10.1117/12.735924 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000010 ER PT S AU DiPirro, M Cottingham, C Boyle, R Ollendorf, S Leisawitz, D AF DiPirro, M. Cottingham, C. Boyle, R. Ollendorf, S. Leisawitz, D. BE MacEwen, HA Breckinridge, JB TI The SPIRIT thermal system - art. no. 66870D SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE thermal modeling; cryogenic; space telescopes ID ADR AB The Space Infrared Interferometric Telescope (SPIRIT) is envisioned to be a pair of one meter diameter primary light collectors on either side of a beam combiner, all cooled to 4 K or lower. During an observation, the collectors are required to move toward and away from the beam combiner to obtain information at various baselines to simulate a filled aperture. The thermal design of this mission as presented in this paper provides each light collector and the beam combiner with separate cryogenic systems. This allows the boom that attaches the combiner and collectors, the motors and many of the mechanisms to operate at room temperature, thus simplifying ground testing and reducing mission cost and complexity. Furthermore, the cryogenic systems consist of passive radiators and mechanical coolers - a cryogen-free approach. This paper gives a description of the requirements and resulting design for this architecture and some of the benefits and difficulties of this approach. A subscale thermal vacuum test of one of the collector thermal systems was performed. The thermal model and test agreed very well showing the viability of the thermal design and subscale cryo-thermal test approach. C1 [DiPirro, M.; Boyle, R.; Ollendorf, S.; Leisawitz, D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP DiPirro, M (reprint author), NASA, Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP D6870 EP D6870 DI 10.1117/12.734140 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000011 ER PT S AU Leitner, J AF Leitner, Jesse BE MacEwen, HA Breckinridge, JB TI Formation flying system design for a planet-finding telescope-occulter system - art. no. 66871D SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE formation flying; space telescope; occulter; planet-finding; spacecraft GN&C AB The concept of flying an occulting shade in formation with an orbiting space telescope to enable astronomical imaging of faint targets while blocking out background noise primarily from starlight near distant Earth-like planets has been studied in various forms over the past decade. Recent analysis has shown that this approach may offer comparable performance to that provided by a space-based coronagraph with reduced engineering and technological challenges as well as overall mission and development costs. This paper will present a design of the formation flying architecture (FFA) for such a collection system that has potential to meet the scientific requirements of the National Aeronautics and Space Administration's (NASA's) Terrestrial Planet Finder mission. The elements of the FFA include the relative navigation, intersatellite communication, formation control, and the spacecraft guidance, navigation, and control (GN&C) systems. The relative navigation system consists of the sensors and algorithms to provide necessary range, bearing or line-of-sight, and relative attitude between the telescope and occulter. Various sensor and filtering (estimation) approaches will be introduced. A formation control and GN&C approach will be defined that provides the proper alignment and range between the spacecraft, occulter, and target to meet scientific objectives. The state of technology will be defined and related to several formation flying and rendezvous spacecraft demonstration missions that have flown. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leitner, J (reprint author), NASA, Goddard Space Flight Ctr, Code 591, Greenbelt, MD 20771 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP D6871 EP D6871 DI 10.1117/12.731626 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000043 ER PT S AU Benford, DJ Rinehart, SA Leisawitz, DT Hyde, TT AF Benford, Dominic J. Rinehart, Stephen A. Leisawitz, David T. Hyde, T. Tupper BE MacEwen, HA Breckinridge, JB TI Cryogenic far-infrared detectors for the Space Infrared Interferometric Telescope (SPIRIT) - art. no. 66870E SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE infrared interferometer; far-infrared astronomy; superconducting bolometer array; transition edge sensor; SQUID multiplexer ID MULTIPLEXER AB SPIRIT is a spatial and spectral interferometer with an operating wavelength range 25 mu m - 400 mu m. As a double-Fourierinterferometer, SPIRIT features sub-arcsecond spatial resolution and R equivalent to lambda/Delta lambda = 3000 spectral resolution over a 1 arcmin field of view. Its three primary scientific objectives are to: (1) Learn how planetary systems form from protostellar disks, and how they acquire their chemical organization; (2) Characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets form, and why some planets are ice giants and others are rocky; and (3) Learn how high-redshift galaxies formed and merged to form the present-day population of galaxies. The detector subsystem provides a set of far-infrared detector arrays in the SPIRIT instrument. These arrays are used for science purposes by detecting the faint interferometric signal. The resulting technology requirement is for a set of eight arrays operating at wavelengths of 25 mu m - 400 mu m, divided into two arrays (one for each interferometer output port) per octave of wavelength. At the short wavelength end, the arrays are 14x14 pixels, shrinking to 2x2 at the longest band. The per-pixel sensitivity requirement of 10-19 W/root Hz, coupled with speed of tau(effective)similar to 150 mu s make these relatively small arrays challenging. The operating temperature necessary to provide this sensitivity is around 50 mK. Over the majority of the SPIRIT wavelength range and sensitivity requirement, there are no commercial vendors of such detector arrays, and thus they will require a separate NASA-supported development. C1 [Benford, Dominic J.; Rinehart, Stephen A.; Leisawitz, David T.; Hyde, T. Tupper] NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. RP Benford, DJ (reprint author), NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012 OI Benford, Dominic/0000-0002-9884-4206 NR 12 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP E6870 EP E6870 DI 10.1117/12.734751 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000012 ER PT S AU Rinehart, SA Armstrong, T Frey, BJ Jung, J Kirk, J Leisawitz, DT Leviton, DB Lyon, R Maher, S Martino, AJ Pauls, T AF Rinehart, S. A. Armstrong, T. Frey, Bradley J. Jung, J. Kirk, J. Leisawitz, David T. Leviton, Douglas B. Lyon, R. Maher, Stephen Martino, Anthony J. Pauls, T. BE MacEwen, HA Breckinridge, JB TI The wide-field imaging interferometry testbed: Enabling techniques for high angular resolution astronomy - art. no. 66870F SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE interferometry; Michelson interferometer; wide-field imaging; synthesis imaging; testbed AB The Wide-Field Imaging Interferometry Testbed (WIIT) was designed to develop techniques for wide-field of view imaging interferometry, using "double-Fourier" methods. These techniques will be important for a wide range of future space-based interferometry missions. We have provided simple demonstrations of the methodology already, and continuing development of the testbed will lead to higher data rates, improved data quality, and refined algorithms for image reconstruction. At present, the testbed effort includes five lines of development; automation of the testbed, operation in an improved environment, acquisition of large high-quality datasets, development of image reconstruction algorithms, and analytical modeling of the testbed. We discuss the progress made towards the first four of these goals; the analytical modeling is discussed in a separate paper within this conference. C1 [Rinehart, S. A.; Frey, Bradley J.; Jung, J.; Leisawitz, David T.; Leviton, Douglas B.; Lyon, R.; Martino, Anthony J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Rinehart, SA (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 665, Greenbelt, MD 20771 USA. RI Lyon, Richard/D-5022-2012 NR 16 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP F6870 EP F6870 DI 10.1117/12.734437 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000013 ER PT S AU Carpenter, KG Lyon, RG Schrijver, C Karovska, M Mozurkewich, D AF Carpenter, Kenneth G. Lyon, Richard G. Schrijver, Carolus Karovska, Margarita Mozurkewich, David BE MacEwen, HA Breckinridge, JB TI Direct UV/optical imaging of stellar surfaces: The Stellar Imager (SI) Vision Mission - art. no. 66870G SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE stars; stellar surfaces; magnetic activity; dynamos; interferometry; high resolution imaging; exo-planets; habitability AB The Stellar Imager (SI) is a UV/optical, space-based interferometer designed to enable 0.1 milli-arcsecond (mas) spectral imaging of stellar surfaces and, via asteroseismology, stellar interiors and of the Universe in general. SI's science focuses on the role of magnetism in the Universe, particularly on magnetic activity on the surfaces of stars like the Sun. SI's prime goal is to enable long-term forecasting of solar activity and the space weather that it drives, in support of the Living with a Star program in the Exploration Era. SI will also revolutionize our understanding of the formation of planetary systems, of the habitability and climatology of distant planets, and of many magneto-hydrodynamically controlled processes in the Universe. SI is a "Flagship and Landmark Discovery Mission" in the 2005 Sun Solar System Connection (SSSC) Roadmap and a candidate for a "Pathways to Life Observatory" in the Exploration of the Universe Division (EUD) Roadmap (May, 2005). We discuss herein the science goals of the SI Mission, a mission architecture that could meet those goals, and the technologies needed to enable this mission. Additional information on SI can be found at: http://hires.gsfe.nasa.gov/si/. C1 [Carpenter, Kenneth G.; Lyon, Richard G.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Carpenter, KG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Carpenter, Kenneth/D-4740-2012 NR 4 TC 5 Z9 5 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP G6870 EP G6870 DI 10.1117/12.732440 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000014 ER PT S AU Lyon, RG Carpenter, KG Liu, A Petrone, P Dogoda, P Reed, D Mozurkewich, D AF Lyon, Richard G. Carpenter, Kenneth G. Liu, Alice Petrone, Peter Dogoda, Peter Reed, Daniel Mozurkewich, David BE MacEwen, HA Breckinridge, JB TI Wavefront sensing and closed-loop control for the Fizeau interferometry testbed - art. no. 66870H SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE imaging interferometry; wavefront sensing; wavefront control; phase retrieval; phase diversity; active optics; adaptive optics ID PHASE RETRIEVAL AB Stellar Imager (SI) is a proposed NASA space-based UV imaging interferometer to resolve the stellar disks of nearby stars. SI would consist of 20 - 30 separate spacecraft flying in formation at the Earth-Sun L2 libration point. Onboard wavefront sensing and control is required to maintain alignment during science observations and after array reconfigurations. The Fizeau Interferometry Testbed (FIT), developed at the NASA/Goddard Space Flight Center, is being used to study wavefront sensing and control methodologies for Stellar Imager and other large, sparse aperture telescope systems. FIT initially consists of 7 articulated spherical mirrors in a Golay pattern, and is currently undergoing expansion to 18 elements. FIT currently uses in-focus whitelight sparse aperture PSFs and a direct solve phase retrieval algorithm to sense and control its wavefront. Ultimately it will use extended scene wavelength, with a sequential diversity algorithm that modulates a subset of aperture pistons to jointly estimate the wavefront and the reconstructed image from extended scenes. The recovered wavefront is decomposed into the eigenmodes of the control matrix and actuators are moved to minimize the wavefront piston, tip and tilt in closed-loop. We discuss the testbed, wavefront control methodology and ongoing work to increase its bandwidth from 1 per 11 seconds to a few 10's of Hertz and show ongoing results. C1 [Lyon, Richard G.; Carpenter, Kenneth G.; Liu, Alice] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lyon, RG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Carpenter, Kenneth/D-4740-2012 NR 15 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP H6870 EP H6870 DI 10.1117/12.731761 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000015 ER PT S AU Leisawitz, D Martino, AJ Thompson, AK Rinehart, SA Frey, BJ AF Leisawitz, David Martino, Anthony J. Thompson, Anita K. Rinehart, Stephen A. Frey, Bradley J. BE MacEwen, HA Breckinridge, JB TI An optical model of the wide-field imaging interferometry testbed - art. no. 66870J SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE interferometry; wide-field imaging; double Fourier interferometry; optical modeling; WIIT; SPIRIT; SPECS AB This paper describes computational results obtained with a high-fidelity optical model of the Wide-Field Imaging Interferometry Testbed (WIIT). The WIIT model includes imperfections inherent in the hardware testbed, such as deviations of the mirrors from their ideal shapes. Model interferograms (brightness in a detector pixel as a function of optical delay) are presented here for several representative test scenes "observed" with multiple interferometric baselines. The results match theoretical expectations and can be compared with real WIIT measurements to identify and characterize instrumental and environmental artifacts in our laboratory data, and to aid in the interpretation of those data. C1 [Leisawitz, David] NASA, Goddard Space Flight Ctr, Sci & Explorat Directorate, Greenbelt, MD 20771 USA. RP Leisawitz, D (reprint author), NASA, Goddard Space Flight Ctr, Sci & Explorat Directorate, Code 605, Greenbelt, MD 20771 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP J6870 EP J6870 DI 10.1117/12.735145 PG 9 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000017 ER PT S AU Stahl, HP AF Stahl, H. Philip BE MacEwen, HA Breckinridge, JB TI Ares V launch capability enables future space telescopes - art. no. 66870L SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE astronomy; large space telescopes; Ares V launch vehicle AB NASA's Ares V cargo launch vehicle offers the potential to completely change the paradigm of future space science mission architectures. A major finding of the NASA Advanced Telescope and Observatory Capability Roadmap Study was that current launch vehicle mass and volume constraints severely limit future space science missions. And thus, that significant technology development is required to package increasingly larger collecting apertures into existing launch shrouds. The Ares V greatly relaxes these constraints. For example, while a Delta IV has the ability to launch approximate a 4.5 meter diameter payload with a mass of 13,000 kg to L2, the Ares V is projected to have the ability to launch an 8 to 12 meter diameter payload with a mass of 60,000 kg to L2 and 130,000 kg to Low Earth Orbit. This paper summarizes the Ares V payload launch capability and introduces how it might enable new classes of future space telescopes such as 6 to 8 meter class monolithic primary mirror observatories, 15 meter class segmented telescopes, 6 to 8 meter class x-ray telescopes or high-energy particle calorimeters. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Stahl, HP (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP L6870 EP L6870 DI 10.1117/12.730853 PG 7 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000019 ER PT S AU Goldsmith, PF Bradford, CM Dragovan, M Khayatian, B Huffenberger, K O'Dwyer, IJ Gorski, K Yorke, HW Zmuidzinas, J Paine, C Satter, C Lee, R AF Goldsmith, P. F. Bradford, C. M. Dragovan, M. Khayatian, B. Huffenberger, K. O'Dwyer, I. J. Gorski, K. Yorke, H. W. Zmuidzinas, J. Paine, C. Satter, C. Lee, R. BE MacEwen, HA Breckinridge, JB TI CALISTO: A cryogenic far-infrared/submillimeter observatory - art. no. 66870P SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE far-infrared; submillimeter; space observatory; crogenic telescope; background-limited sensitivity AB We present a design for a cryogenically cooled large aperture telescope for far-infrared astronomy in the wavength range 30 mu m to 300 mu m. The Cryogenic Aperture Large Infrared Space Telescope Observatory, or CALISTO, is based on an off-axis Gregorian telesocope having a 4 m by 6 m primary reflector. This can be launched using an Atlas V 511, with the only optical deployment required being a simple hinged rotation of the secondary reflector. The off-axis design, which includes a cold stop, offers exceptionally good performance in terms of high efficiency and minimum coupling of radiation incident from angles far off the direction of maximum response. This means that strong astronomical sources, such as the Milky Way and zodiacal dust in the plane of the solar system, add very little to the background. The entire optical system is cooled to 4 K to make its emission less than even this low level of astronomical emission. Assuming that detector technology can be improved to the point where detector noise is less than that of the astronomical background, we anticipate unprecedented low values of system noise equivalent power, in the vicinity of 10(-19) WHz(-0.5), through CALISTO's operating range. This will enable a variety of new astronomical investigations ranging from studies of objects in the outer solar system to tracing the evolution of galaxies in the universe throughout cosmic time. C1 [Goldsmith, P. F.; Bradford, C. M.; Dragovan, M.; Khayatian, B.; Huffenberger, K.; O'Dwyer, I. J.; Gorski, K.; Yorke, H. W.; Zmuidzinas, J.; Paine, C.; Satter, C.; Lee, R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Goldsmith, PF (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP P6870 EP P6870 DI 10.1117/12.731049 PG 13 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000023 ER PT S AU Pasquale, BA Woodruff, RA Lauer, TR Benford, DJ AF Pasquale, Bert A. Woodruff, Robert A. Lauer, Tod R. Benford, Dominic J. BE MacEwen, HA Breckinridge, JB TI DESTINY: The dark energy space telescope - art. no. 66870Q SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE dark energy; space telescope; supernovae; Type Ia; three mirror anastigmat; weak lensing; near-infrared AB We have proposed the development of a low-cost space telescope, Destiny, as a concept for the NASA/DOE Joint Dark Energy Mission. Destiny is a 1.65m space telescope, featuring a near-infrared (0.85-1.7m) survey camera/spectrometer with a large flat-field Field Of View (FOV). Destiny will probe the properties of dark energy by obtaining a Hubble diagram based on Type la supernovae (SN) and a large-scale mass power spectrum derived from weak lensing distortions of field galaxies as a function of redshift. C1 [Pasquale, Bert A.; Benford, Dominic J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pasquale, BA (reprint author), NASA, Goddard Space Flight Ctr, Code 551, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012 OI Benford, Dominic/0000-0002-9884-4206 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 P SOC PHOTO-OPT INS PY 2007 VL 6687 BP Q6870 EP Q6870 DI 10.1117/12.735180 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000024 ER PT S AU Bradford, CM Goldsmith, PF Dragovan, M Kenyon, M Holmes, W Yorke, H AF Bradford, C. Matt Goldsmith, Paul F. Dragovan, Mark Kenyon, Matt Holmes, Warren Yorke, Harold BE MacEwen, HA Breckinridge, JB TI Instrumentation for the next-generation cryogenic space-borne far-IR observatories SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS III SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts III CY AUG 26-29, 2007 CL San Diego, CA SP SPIE DE SPICA; far-infrared; bolometers; spectroscopy; SAFIR; CALISTO ID BROAD-BAND; GALAXIES; SPITZER; SUBMILLIMETER; SPECTROMETER; TELESCOPE; EMISSION; COUNTS AB We present scientific rationale, concepts and technologies for far-IR (lambda=35-600 mu m) instrumentation for the cryogenic single-dish space telescopes envisioned for the next two decades. With the tremendous success of Spitzer, the stage is set for larger (3-10 meter) actively-cooled telescopes and several are under consideration including SPICA in Japan, and CALISTO/SAFIR in the US. The cold platforms offer the potential for far-IR observations limited only by the zodiacal dust emission and other diffuse astrophysical foregrounds. Optimal instrumentation for these missions includes large-format direct-detector arrays with sensitivity matched to the low photon backgrounds. This will require major improvements relative to the current state of the art, especially for wavelengths beyond the 38-micron silicon BIB cutoff, We review options and present progress with one approach: superconducting bolometers. We highlight in particular the scientific potential for moderate-resolution broadband spectroscopy. The large cold telescopes can provide line sensitivities below 10(-20) W m(-2), enabling the first routine survey spectroscopy of the redshift 0.5 to 5 galaxies that produced the cosmic far-IR backo-round. These far-IR-bright dusty galaxies account for half of the photon energy released since stars and galaxies began forming, and the new far-IR spectroscopic capability will reveal their energy sources and chart their history. We describe concepts for the background-limited IR-Submillimeter Spectrograph (BLISS) designed for this purpose. BLISS is a suite of R similar to 1000 spectrometer modules spanning the far-IR range, and is under study for SPICA; a similar but more capable instrument can be scaled for CALISTO/SAFIR. C1 [Bradford, C. Matt; Yorke, Harold] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bradford, CM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM bradford@caltech.edu NR 19 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6835-2 J9 PROC SPIE PY 2007 VL 6687 AR 66870O DI 10.1117/12.732657 PG 13 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BHM68 UT WOS:000254292000022 ER PT S AU O'Dell, SL Aldcroft, TL Blackwell, WC Bucher, SL Chappell, JH DePasquale, JM Grant, CE Juda, M Martin, ER Minow, JI Murray, SS Plucinsky, PP Schwartz, DA Shropshire, DP Spitzbart, BJ Viens, PR Wolk, SJ AF O'Dell, Stephen L. Aldcroft, Thomas L. Blackwell, William C. Bucher, Sabina L. Chappell, Jon H. DePasquale, Joseph M. Grant, Catherine E. Juda, Michael Martin, Eric R. Minow, Joseph I. Murray, Stephen S. Plucinsky, Paul P. Schwartz, Daniel A. Shropshire, Daniel P. Spitzbart, Bradley J. Viens, Paul R. Wolk, Scott J. BE Siegmund, OHW TI anaging radiation degradation of CCDs on the Chandra x-ray Observatory - III - art. no. 668603 SO UV, X-RAY, AND GAMMA-RAY SPACE INSTRUMENTATION FOR ASTRONOMY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV, X-Ray and Gamma-Ray Space Instrumentation for Astronomy XV CY AUG 26-27, 2007 CL San Diego, CA SP SPIE DE X-ray astronomy; CCDs; radiation damage; radiation environment; spacecraft operations ID ADVANCED COMPOSITION EXPLORER; CHARGE-TRANSFER INEFFICIENCY; IMAGING SPECTROMETER; ACIS INSTRUMENT; ALPHA MONITOR; PERFORMANCE; MODEL; ENVIRONMENT; ELECTRON; PROTON AB Soon after the start of science operations of the Chandra X-ray Observatory, it became apparent that weakly penetrating (0.1-0.5 MeV) protons in the Earth's radiation belt were causing an unexpectedly rapid increase in the charge-transfer inefficiency of Chandra's front-illuminated CCDs. Fortunately, the Chandra team developed, implemented, and maintains a radiation-protection program that successfully reduced the rate of degradation of the CCDs' performance to acceptable levels. Since implementing this program, the average rate of increase of the charge-transfer inefficiency has slowed to 3.2x10(-6)/y (2.3%/y) for the front-illuminated CCDs and 1.0x10(-6)/y (5.8%/y) for the back-illuminated CCDs. This paper reviews the Chandra radiation-management program, reports the current status, and describes changes planned or implemented since the previous paper on this topic. C1 [O'Dell, Stephen L.] NASA, George C Marshall Space Flight Ctr, NSSTC VP62, Huntsville, AL 35805 USA. RP O'Dell, SL (reprint author), NASA, George C Marshall Space Flight Ctr, NSSTC VP62, 320 Sparkman Dr, Huntsville, AL 35805 USA. OI Juda, Michael/0000-0002-4375-9688; Wolk, Scott/0000-0002-0826-9261; O'Dell, Stephen/0000-0002-1868-8056 NR 29 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6834-5 J9 P SOC PHOTO-OPT INS PY 2007 VL 6686 BP 68603 EP 68603 DI 10.1117/12.734594 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BGZ45 UT WOS:000251497500002 ER PT S AU Petre, R White, NE Tananbaum, H Hornschemeier, A Bookbinder, J Garcia, M Grady, J Kilbourne, C AF Petre, Robert White, Nicholas E. Tananbaum, Harvey Hornschemeier, Ann Bookbinder, Jay Garcia, Michael Grady, Jean Kilbourne, Caroline BE Siegmund, OHW TI The status of the Constellation-X mission - art. no. 66860B SO UV, X-RAY, AND GAMMA-RAY SPACE INSTRUMENTATION FOR ASTRONOMY XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV, X-Ray and Gamma-Ray Space Instrumentation for Astronomy XV CY AUG 26-27, 2007 CL San Diego, CA SP SPIE DE Constellation-X; X-rays; black holes; dark energy AB The Constellation-X mission will address questions central to the NASA Beyond Einstein Program, using high throughput X-ray spectroscopy to measure the effects of strong gravity close to the event horizon of black holes, study the formation and evolution of clusters of galaxies to precisely determine cosmological parameter values, measure the properties of the Warm-Hot Intergalactic Medium, and determine the equation of state of neutron stars. Achieving these science goals requires a factor of similar to 100 increase in sensitivity for high resolution spectroscopy over current X-ray observatories. This paper briefly describes the Constellation-X mission, summarizes its basic performance parameters such as effective area and spectral resolution, and gives a general update on the mission. The details of the updated mission configuration, compatible with a single Atlas-V 551 launch vehicle, are presented. C1 [Petre, Robert; Hornschemeier, Ann; Kilbourne, Caroline] NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. RP Petre, R (reprint author), NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Code 662, Greenbelt, MD 20771 USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 6 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6834-5 J9 P SOC PHOTO-OPT INS PY 2007 VL 6686 BP B6860 EP B6860 DI 10.1117/12.734379 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BGZ45 UT WOS:000251497500010 ER PT S AU Kilbourne, CA Bandler, SR Brown, AD Chervenak, JA Figueroa-Feliciano, E Finkbeiner, FM Iyomoto, N Kelley, RL Porter, FS Smith, SJ AF Kilbourne, Caroline A. Bandler, Simon R. Brown, Ari-D. Chervenak, James A. Figueroa-Feliciano, Enectali Finkbeiner, Fred M. Iyomoto, Naoko Kelley, Richard L. Porter, F. Scott Smith, Stephen J. BE Siegmund, OHW TI Uniform high spectral resolution demonstrated in arrays of TES x-ray microcalorimeters SO UV, X-RAY, AND GAMMA-RAY SPACE INSTRUMENTATION FOR ASTRONOMY XV SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on UV, X-Ray and Gamma-Ray Space Instrumentation for Astronomy XV CY AUG 26-27, 2007 CL San Diego, CA SP SPIE DE microcalorimeters; transition-edge sensors; Constellation-X ID TRANSITION-EDGE SENSORS AB Individual x-ray calorimeters based on superconducting transition-edge sensors (TES) have already demonstrated the spectral resolution, speed, and quantum efficiency needed for astrophysical x-ray spectroscopy. We are now beginning to realize this capability on the array scale for the first time. We have developed a new design for the x-ray absorber that has connections to the TES engineered to allow contact only in regions that do not serve as the active thermometer. We have further constrained the design so that a low-resistance absorber will not electrically short the TES, permitting the use of high-conductivity electroplated gold for the x-ray absorber. With such a well-behaved material for the absorber; we now achieve energy resolution at 6 keV in the range 2.4 - 3.1 eV FWHM in all the pixels of the same design tested in a close-packed array. We have achieved somewhat higher resolution and faster response by eliminating some of the gold and electroplating bismuth in its place. These are important steps towards the high-resolution, high-fill-factor, microcalorimeter arrays needed for x-ray astrophysics observatories such as Constellation-X. C1 [Kilbourne, Caroline A.; Bandler, Simon R.; Brown, Ari-D.; Chervenak, James A.; Figueroa-Feliciano, Enectali; Finkbeiner, Fred M.; Iyomoto, Naoko; Kelley, Richard L.; Porter, F. Scott; Smith, Stephen J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kilbourne, CA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Caroline.A.Kilbourne@nasa.gov RI Kelley, Richard/K-4474-2012; Smith, Stephen/B-1256-2008; Bandler, Simon/A-6258-2010; Porter, Frederick/D-3501-2012 OI Smith, Stephen/0000-0003-4096-4675; Bandler, Simon/0000-0002-5112-8106; Porter, Frederick/0000-0002-6374-1119 NR 17 TC 0 Z9 0 U1 1 U2 5 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 978-0-8194-6834-5 J9 PROC SPIE PY 2007 VL 6686 AR 668606 DI 10.1117/12.734830 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BGZ45 UT WOS:000251497500005 ER PT S AU Lee, K Wilson, T Zapp, N Pinsky, L AF Lee, Kerry Wilson, Thomas Zapp, Neal Pinsky, Lawrence CA FLUKA collaboration BE Civitarese, O Dorso, C Bermudez, GG Kreiner, AJ Pacheco, AJ Scoccola, NN TI Space applications of the FLUKA Monte-Carlo Code: Lunar and planetary exploration SO VI LATIN AMERICAN SYMPOSIUM ON NUCLEAR PHYSICS AND APPLICATIONS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 6th Latin American Symposium on Nuclear Physics and Applications CY OCT 03-07, 2005 CL Iguazu, ARGENTINA SP Agencia Nacl Promoc Cient Tecnol, Ctr Latinoamer Fis, Consejo Nacl Invest Cient Tecn Argentina, Int Ctr Theoret Phys, Fdn Antorchas DE heavy-ion collisions; cosmic rays; particle albedos AB NASA has recognized the need for making additional heavy-ion collision measurements at the U.S. Brookhaven National Laboratory in order to support further improvement of several particle physics transport-code models for space exploration applications. FLUKA has been identified as one of these codes and we will review the nature and status of this investigation as it relates to high-energy heavy-ion physics. C1 [Lee, Kerry; Wilson, Thomas; Zapp, Neal] NASA, Lyndon B Johnson Space Ctr, 2101 NASA Pkwy,Code KR, Houston, TX 77058 USA. [Pinsky, Lawrence] Univ Houston, Houston, TX 77204 USA. RP Lee, K (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Pkwy,Code KR, Houston, TX 77058 USA. FU INFN,NASA [NAG8-1901] FX FLUKA development as discussed here has been partially funded by financial support from INFN as well as NASA under Grant NAG8-1901. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0388-8 J9 AIP CONF PROC PY 2007 VL 884 BP 243 EP + PG 3 WC Physics, Multidisciplinary; Physics, Nuclear SC Physics GA BGA65 UT WOS:000245812000035 ER PT J AU Ludwig, CJH Eckstein, MP Beutter, BR AF Ludwig, Casimir J. H. Eckstein, Miguel P. Beutter, Brent R. TI Limited flexibility in the filter underlying saccadic targeting SO VISION RESEARCH LA English DT Article DE saccadic eye movements; spatial vision; decision-making; template-matching; contrast ID CONTRAST SENSITIVITY; VISUAL-SEARCH; NOISE; DISCRIMINATION; SIGNAL; PERFORMANCE; FIELD; CUES AB The choice of where to look in a visual scene depends on visual processing of information from potential target locations. We examined to what extent the sampling window, or filter, underlying saccadic eye movements is under flexible control and adjusted to the behavioural task demands. Observers performed a contrast discrimination task with systematic variations in the spatial scale and location of the visual signals: small (sigma = 0.175 degrees) or large (sigma = 0.8 degrees) Gaussian signals were presented 4.5 degrees, 6 degrees, or 9 degrees away from central fixation. In experiment 1, we measured the accuracy of the first saccade as a function of target contrast. The efficiency of saccadic targeting decreased with increases in both scale and eccentricity. In experiment 2, the filter underlying saccadic targeting was estimated with the classification image method. We found that the filter (1) had a center-surround organisation, even though the signal was Gaussian; (2) was much too small for the large scale items; (3) remained constant up to the largest measured eccentricity of 9 degrees. The filter underlying the decision of where to look is not fixed, and can be adjusted to the task demands. However, there are clear limits to this flexibility. These limits reflect the coding of visual information by early mechanisms, and the extent to which the neural circuitry involved in programming saccadic eye movements is able to appropriately weigh and combine the outputs from these mechanisms. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Bristol, Dept Expt Psychol, Bristol BS8 1TU, Avon, England. Univ Calif Santa Barbara, Dept Psychol, Santa Barbara, CA 93106 USA. NASA, Ames Res Ctr, Human Performance Div, Moffett Field, CA 94035 USA. RP Ludwig, CJH (reprint author), Univ Bristol, Dept Expt Psychol, 12A Priory Rd, Bristol BS8 1TU, Avon, England. EM c.ludwig@bristol.ac.uk; eckstein@psych.ucsb.edu; bbeuter@mail.arc.nasa.gov OI Ludwig, Casimir/0000-0003-4656-0751 NR 29 TC 9 Z9 9 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0042-6989 J9 VISION RES JI Vision Res. PD JAN PY 2007 VL 47 IS 2 BP 280 EP 288 DI 10.1016/j.visres.2006.09.009 PG 9 WC Neurosciences; Ophthalmology SC Neurosciences & Neurology; Ophthalmology GA 134BH UT WOS:000244057100014 PM 17070887 ER PT B AU Brenner, MJ Kukreja, SL Prazenica, RJ AF Brenner, Martin J. Kukreja, Sunil L. Prazenica, Richard J. BE Tao, Q Mang, V Xu, Y TI Signal-adaptive aeroelastic flight data analysis with HHT SO WAVELET ANALYSIS AND APPLICATIONS SE Applied and Numerical Harmonic Analysis LA English DT Proceedings Paper CT Conference on Wavelet Analysis and Applications CY NOV 29-DEC 02, 2005 CL Univ Macau, MACAO HO Univ Macau DE aeroelasticity; adaptive signal decomposition; Hilbert-Huang; empirical mode decomposition; time-frequency analysis ID EMPIRICAL MODE DECOMPOSITION; HUANG SPECTRAL-ANALYSIS; SYSTEM-IDENTIFICATION; HILBERT SPECTRUM; FREQUENCY AB This paper investigates the utility of the Hilbert-Huang transform for the analysis of aeroelastic flight data. The recently-developed Hilbert-Huang algorithm addresses the limitations of the classical Hilbert transform through a process known as empirical mode decomposition. Using this approach, the data is filtered into a series of intrinsic mode functions, each of which admits a well-behaved Hilbert transform. In this manner, the Hilbert-Huang algorithm affords time-frequency analysis of a large class of signals. The purpose of this paper is to demonstrate the potential applications of the Hilbert-Huang algorithm for the analysis of aeroelastic systems. Applications for correlations between system input and output, and amongst output sensors, are discussed to characterize the time-varying amplitude and frequency correlations present in the various components of multiple data channels. Examples are given using aeroelastic flight test data from the F/A-18 Active Aeroelastic Wing aircraft and Aerostructures Test Wing. C1 [Brenner, Martin J.; Kukreja, Sunil L.] NASA Dryden Flight Res Ctr, Aerostruct Branch, Aerosp Engn, Edwards AFB, CA 93523 USA. [Prazenica, Richard J.] Univ Florida, UF Res Engn Educ Fac REEF, Gainesville, FL 32611 USA. RP Brenner, MJ (reprint author), NASA Dryden Flight Res Ctr, Aerostruct Branch, Aerosp Engn, Edwards AFB, CA 93523 USA. EM Martin.J.Brenner@nasa.gov; Sunil.Kukreja@nasa.gov; prazenic@ufl.edu NR 32 TC 0 Z9 0 U1 0 U2 4 PU BIRKHAUSER BOSTON PI CAMBRIDGE PA 675 MASSACHUSETTS AVE, CAMBRIDGE, MA 02139-2333 USA BN 978-3-7643-7777-9 J9 APPL NUMER HARMON AN PY 2007 BP 321 EP + DI 10.1007/978-3-7643-7778-6_24 PG 5 WC Mathematics, Applied; Mathematics SC Mathematics GA BFX80 UT WOS:000245342000024 ER PT J AU Flom, Y AF Flom, Yury TI Electron beam brazing for in-space construction SO WELDING JOURNAL LA English DT Editorial Material C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RP Flom, Y (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. EM yury.a.flom@nasa.gov NR 9 TC 2 Z9 4 U1 0 U2 0 PU AMER WELDING SOC PI MIAMI PA 550 N W LEJEUNE RD, MIAMI, FL 33126 USA SN 0043-2296 J9 WELD J JI Weld. J. PD JAN PY 2007 VL 86 IS 1 BP 33 EP 37 PG 5 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 123QE UT WOS:000243309600007 ER PT S AU Altobelli, N Kempf, S Roy, M Srama, R Helfert, S Moragas-Klostermeyer, G Grun, E AF Altobelli, N. Kempf, S. Roy, M. Srama, R. Helfert, S. Moragas-Klostermeyer, G. Gruen, E. GP ESA TI Preliminary results on analysis of the cosmic dust analyzer data between Jupiter and Saturn SO Workshop on Dust in Planetary Systems SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Workshop on Dust in Planetary Systems CY SEP 26-30, 2005 CL Kauai, HI SP NASA, ESA, Lunar & Planetary Inst, Hawaii Inst Geophys & Planetol, Univ Hawaii Manoa ID GALILEO; DETECTOR; STREAMS AB We present the Cosmic Dust Analyzer (CDA) data obtained by the Cassini spacecraft during the interplanetary cruise phase between the Jupiter fly-by and the Saturn orbit insertion (SOI). Prior to the Cassini mission, the only in-situ dust detectors ever flown between Jupiter and Saturn were the Pioneer 10 and Pioneer 11 dust experiments. However, owing to the sensitivity of these instruments, only big particles (larger than 10 pm for Pioneer 10 and larger than 25 pm for Pioneer 11) could be detected. In contrast, CDA allows the detection of smaller grains. In particular, hundreds of high-velocity tiny dust particles, so-called stream particles, originating from both the Jovian and Saturnian systems were detected even at great distances from their source. In addition, we identified 17 interplanetary dust particles (IDPs), most probably of cometary origin, on moderate to high eccentric orbits. Furthermore, an impact cluster was identified, relying on both directional and temporal criteria, suggesting an encounter with a cometary trail. The shape of the impact charge signals suggests porous material for those particles. C1 NASA, JPL, Pasadena, CA 91109 USA. RP Altobelli, N (reprint author), NASA, JPL, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI KEMPF, SASCHA/0000-0001-5236-3004 NR 23 TC 0 Z9 0 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 978-92-9092-207-0 J9 ESA SP PUBL PY 2007 VL 643 BP 65 EP 68 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGB26 UT WOS:000245892600011 ER PT S AU Abbas, MM Tankosic, D Craven, PD Hoover, RB Taylor, LA Spann, JF LeClair, A West, EA AF Abbas, M. M. Tankosic, D. Craven, P. D. Hoover, R. B. Taylor, L. A. Spann, J. F. LeClair, A. West, E. A. GP ESA TI Measurements of photoelectric yields of individual lunar dust grains SO Workshop on Dust in Planetary Systems SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Workshop on Dust in Planetary Systems CY SEP 26-30, 2005 CL Kauai, HI SP NASA, ESA, Lunar & Planetary Inst, Hawaii Inst Geophys & Planetol, Univ Hawaii Manoa ID ELECTROSTATIC CHARGING PROPERTIES; IONIZATION-POTENTIALS; METAL-CLUSTERS; WORK FUNCTION; PARTICLES; PHOTOEMISSION; RADIATION; ENERGY; MODEL AB It is well known since the Apollo missions that just above the lunar regolith is a layer of levitated dust that is electrostatically charged by the incident solar UV radiation and by interaction with the solar wind. Photoelectric. emissions induced by the UV radiation at photon energies higher than the work function of the grain materials, however, are recognized to be the dominant process for charging of the lunar dust in the sunlight. This requires measurement of the photoelectric yield of individual dust grains to determine their charge and equilibrium potentials. In this paper, we present the first laboratory measurements of the photoelectric yields of individual micron/sub-micron size dust grains selected from soil samples from the Soviet Luna-24 Mission. The experimental results on photoelectric emissions indicate that the yields are dust size dependent. The yields increase with the grain size by an order of magnitude from the sub-micron size to grains of several microns radii, at which they reach asymptotic values. The yields for large-size grains were determined to be more than an order of magnitude higher than the bulk measurements reported in the literature. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35801 USA. RP Abbas, MM (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35801 USA. NR 34 TC 1 Z9 1 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 978-92-9092-207-0 J9 ESA SP PUBL PY 2007 VL 643 BP 165 EP 170 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGB26 UT WOS:000245892600029 ER PT S AU Stubbs, TJ HalekaS, JS Farrell, WM Vondrak, RR AF Stubbs, Timothy J. HalekaS, Jasper S. Farrell, William M. Vondrak, Richard R. GP ESA TI Lunar surface charging: A global perspective using lunar prospector data SO Workshop on Dust in Planetary Systems SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Workshop on Dust in Planetary Systems CY SEP 26-30, 2005 CL Kauai, HI SP NASA, ESA, Lunar & Planetary Inst, Hawaii Inst Geophys & Planetol, Univ Hawaii Manoa ID PLASMA; DUST; SPACE; WAKE AB The electrostatic charging of the lunar surface is caused by its interaction with the local plasma environment and solar UV and X-ray induced photoemission of electrons. Probe equations are used here to calculate electrostatic lunar surface potentials as a function of angle from the subsolar point, thus giving a global perspective on charging processes. Since the Moon is in the solar wind plasma flow for most of its orbit, surface potentials are first determined for typical fast and slow stream conditions. They are then calculated using data from the Electron Reflectometer aboard Lunar Prospector. The latter reveals how the hot tenuous plasma of the lunar wake drives large negative surface potentials (up to -200 V) on the nightside of the Moon. Lunar surface charging in the Earth's magnetosphere is also discussed, with initial predictions indicating that the nightside charges to similar to -600 V in the plasma sheet. The ability to predict surface potentials is vital for understanding the lunar environment; in particular, processes such as ion sputtering and electrically-driven dust transport. The latter is especially important since dust significantly interfered with Apollo exploration activities. C1 NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP Stubbs, TJ (reprint author), NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RI Stubbs, Timothy/I-5139-2013; Farrell, William/I-4865-2013 OI Stubbs, Timothy/0000-0002-5524-645X; NR 22 TC 8 Z9 8 U1 1 U2 2 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 978-92-9092-207-0 J9 ESA SP PUBL PY 2007 VL 643 BP 181 EP 184 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGB26 UT WOS:000245892600032 ER PT S AU Stubbs, TJ Vondrak, RR Farrell, WM AF Stubbs, Timothy J. Vondrak, Richard R. Farrell, William M. GP ESA TI A dynamic fountain model for dust in the lunar exosphere SO Workshop on Dust in Planetary Systems SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Workshop on Dust in Planetary Systems CY SEP 26-30, 2005 CL Kauai, HI SP NASA, ESA, Lunar & Planetary Inst, Hawaii Inst Geophys & Planetol, Univ Hawaii Manoa ID LEVITATION; TRANSPORT; SURFACES; SHEATH; PLASMA; SPACE AB From the Apollo era there is much evidence to show that the lunar "horizon glow" and "streamers" observed at the terminator are caused by sunlight scattered by dust grains originating from the Moon's surface. A simple dynamic dust "fountain" model has previously been proposed to explain observations of submicron dust "lofted" to altitudes of similar to 100 km. In this model charged dust grains follow ballistic trajectories, subsequent to being accelerated upwards through a narrow sheath region by the surface electric field. Described here are the effects of including a more realistic exponentially decaying electric field (consistent with Debye shielding of a charged surface in a plasma). Also discussed are the different mechanisms by which highly charged dust grains can be generated at the lunar surface; in particular, the possible effects of triboelectric charging are considered. Dust in the exosphere will affect the optical quality of the lunar environment for astronomical observations, as well as interfere with future robotic and human exploration activities. C1 NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP Stubbs, TJ (reprint author), NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RI Stubbs, Timothy/I-5139-2013; Farrell, William/I-4865-2013 OI Stubbs, Timothy/0000-0002-5524-645X; NR 17 TC 7 Z9 7 U1 1 U2 4 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 978-92-9092-207-0 J9 ESA SP PUBL PY 2007 VL 643 BP 185 EP 189 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGB26 UT WOS:000245892600033 ER PT S AU Tsou, P Giovane, F Liou, JC Corsaro, R AF Tsou, P. Giovane, F. Liou, J-C. Corsaro, R. GP ESA TI LARGE AREA DUST COLLECTION - on the International Space Station SO Workshop on Dust in Planetary Systems SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Workshop on Dust in Planetary Systems CY SEP 26-30, 2005 CL Kauai, HI SP NASA, ESA, Lunar & Planetary Inst, Hawaii Inst Geophys & Planetol, Univ Hawaii Manoa ID PARTICLES; CAPTURE; AEROGEL; RETURN AB The Large Area Dust Collection (LADC), > 10 m(2) of instrumented silica aerogel mounted externally on the International Space Station, will capture and return large dust particles intercepted in Earth orbit. The uniqueness of LADC is that it carries a self-contained acoustic impact recording and locationing system to offer the opportunity to determine the particles' trajectories nondestructively and, for the first time, an opportunity to ascertain the particles' parent sources. Another uniqueness of LADC is that the flight cost for space deployment, integration and Earth return will be provided by the Department of Defense (DoD) Space Test Program (STP). LAD-C flight will also provide statistical significant samples of similar to thirty 100 mu m large extraterrestrial particles and the retrieval of samples themselves for detailed Earth based laboratory analysis to determine the chemical and physical nature of the particles. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tsou, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 32 TC 0 Z9 0 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 978-92-9092-207-0 J9 ESA SP PUBL PY 2007 VL 643 BP 219 EP 226 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGB26 UT WOS:000245892600040 ER PT S AU Stubbs, TJ Vondrak, RR Farrell, WM AF Stubbs, Timothy J. Vondrak, Richard R. Farrell, William M. GP ESA TI Impact of dust on lunar exploration SO Workshop on Dust in Planetary Systems SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Workshop on Dust in Planetary Systems CY SEP 26-30, 2005 CL Kauai, HI SP NASA, ESA, Lunar & Planetary Inst, Hawaii Inst Geophys & Planetol, Univ Hawaii Manoa AB All astronauts who walked on the Moon reported difficulties with lunar dust. These problems were likely worsened by the fact that the dust was electrically charged, which enhanced its adhesive properties. In order to develop strategies to tackle these issues it will be necessary to advance our theoretical understanding of the lunar dust-plasma environment, as well as comprehensively characterize it with in-situ measurements. Summarized here are the relevant properties of lunar dust and its impact on astronauts, together with a discussion of the three main problem areas: (1) Dust Adhesion and Abrasion, (2) Surface Electric Fields and (3) Dust Transport. Also discussed are recent calculations relating to some of the Apolloera observations, together with necessary future in-situ measurements and suggested mission strategies. C1 NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP Stubbs, TJ (reprint author), NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RI Stubbs, Timothy/I-5139-2013; Farrell, William/I-4865-2013 OI Stubbs, Timothy/0000-0002-5524-645X; NR 20 TC 9 Z9 9 U1 1 U2 3 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 978-92-9092-207-0 J9 ESA SP PUBL PY 2007 VL 643 BP 239 EP 243 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BGB26 UT WOS:000245892600044 ER PT B AU Kocsis, M Tan, HZ Adelstein, BD AF Kocsis, Matthew Tan, Hong Z. Adelstein, Bernard D. TI Discriminability of real and virtual surfaces with triangular gratings SO WORLD HAPTICS 2007: SECOND JOINT EUROHAPTICS CONFERENCE AND SYMPOSIUM ON HAPTIC INTERFACES FOR VIRTUAL ENVIRONMENT AND TELEOPERATOR SYSTEMS, PROCEEDINGS LA English DT Proceedings Paper CT 2nd Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems CY MAR 22-24, 2007 CL Tsukuba, JAPAN SP Virtual Real Soc Japan, IEEE, IEEE Robot & Automat Soc, IEEE TCVG ID ROUGHNESS AB Human sensitivity to height differences in textured surfaces is on the order of microns. Research on human texture perception requires texture samples with precisely controlled micro-geometry. This can be achieved I with an electrical discharge machining (EDM) procedure, but the process is time consuming and labor intensive. An alternative approach is to simulate textured surfaces with a haptic interface with high position resolution. The present study measured the amplitude discrimination thresholds for surfaces with triangular gratings using real EDM textured samples and virtual textures rendered with a high-precision force-feedback device called the ministick. The results indicated that the just noticeable differences for real and virtual textures, respectively 3.69 +/- 0.65 and 4.94 +/- 40.96 mu m, were of similar magnitude. Therefore, we propose that this device is suitable for the study human perception of surface micro-geometry with features on the scale of human perceptual resolution. C1 [Kocsis, Matthew; Tan, Hong Z.] Purdue Univ, Hapt Interface Res Lab, W Lafayette, IN 47907 USA. [Adelstein, Bernard D.] NASA, Ames Res Ctr, Human Syst Integrat Div, Washington, DC 20546 USA. RP Kocsis, M (reprint author), Purdue Univ, Hapt Interface Res Lab, W Lafayette, IN 47907 USA. EM mkocsis@purdue.edu; hongtan@purdue.edu; Bernard.D.Adelstein@nasa.gov FU National Science Foundation Award [0098443-IIS]; NASA [NCC 2- 1363]; School of Electrical and Computer Engineering at Purdue University; NASAs Space Human Factors Engineering Program FX This work was supported in part by a National Science Foundation Award under Grant No. 0098443-IIS, and in part by NASA under award no. NCC 2- 1363. MK was also supported by a Fellowship from the School of Electrical and Computer Engineering at Purdue University. BDA was supported by NASAs Space Human Factors Engineering Program. NR 8 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 978-0-7695-2738-3 PY 2007 BP 348 EP + PG 3 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BGD12 UT WOS:000246105200058 ER PT S AU Johnson, PV Malone, CP Khakoo, MA McConkey, JW Kanik, I AF Johnson, P. V. Malone, C. P. Khakoo, M. A. McConkey, J. W. Kanik, I. BE Becker, U Moshammer, R Mokler, P Ullrich, J TI Electron collisions with constituents of planetary atmospheres SO XXV INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC AND ATOMIC COLLISIONS SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 25th International Conference on Photonic, Electronic and Atomic Collisions CY JUL 25-31, 2007 CL Freiburg, GERMANY SP Max Planck Gesell, Max Planck Inst Kernphys, Deutsche Forschungsgemein, IUPAP, Gesell Schwerionenforsch mbH, Land Baden Wurttemberg, Coherent, RoentDek Handels GmbH, Albert Ludwigs Univ Freiburg, Linde Kryotech GmbH, Kapteyn Murnane Lab, SAES Getters, iseg high voltage, IOP Electron Journals, Univ Kassels, Agilent Technologies, FEMTOLASERS GmbH ID EXTREME ULTRAVIOLET OBSERVATIONS; VIBRATIONAL-EXCITATION; VOYAGER-1 ENCOUNTER; HYDROGEN MOLECULES; STATES; RECOMBINATION; THERMOSPHERE; SPECTROSCOPY; SPECTRUM; JUPITER AB Collisions between electrons and neutral species play an important role in the energy balance of upper atmospheres throughout the Solar System. These processes, and the subsequent photon emissions produced, provide one of the primary means for probing, diagnosing and understanding the dynamics of these environments. Modelling of these plasmas and interpretation of optical observations requires accurate knowledge of atomic/molecular parameters such as oscillator strengths and predissociation. yields along with cross sections for electron impact excitation (and emission) with the constituent species of these atmospheres. In this paper, our recent work involving electron collisions with two of the most important atmospheric species in our Solar System, namely N-2 and H-2, will be reviewed. Preliminary differential cross sections for excitation of the B (1)Sigma(+)(u) and C (1)Pi(u) states out of the X (1)Sigma(+)(g) (v ''=1) ground state level of H-2 are presented. C1 [Johnson, P. V.; Malone, C. P.; McConkey, J. W.; Kanik, I.] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. [Khakoo, M. A.] Calif State Univ, Dept Phys, Fullerton, CA 92834 USA. RP Johnson, PV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Paul.V.Johnson@jpl.nasa.gov NR 32 TC 9 Z9 10 U1 1 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2007 VL 88 AR UNSP 012069 DI 10.1088/1742-6596/88/1/012069 PG 8 WC Optics; Physics, Applied SC Optics; Physics GA BHR28 UT WOS:000255634300069 ER PT J AU Stelmakh, S Grzanka, E Wojdyr, M Proffen, T Vogel, SC Zerda, TW Palosz, W Palosz, B AF Stelmakh, Svitlana Grzanka, Ewa Wojdyr, Marcin Proffen, Thomas Vogel, Sven C. Zerda, T. Waldek Palosz, Witold Palosz, Bogdan TI Neutron diffraction studies of the atomic thermal vibrations in complex materials: application of the Wilson method to examination of micro- and nano-crystalline SiC SO ZEITSCHRIFT FUR KRISTALLOGRAPHIE LA English DT Article DE neutron diffraction; atomic vibrations; silicon carbide; Wilson method ID NANOCRYSTALS; HEAT AB The Wilson method was applied for determination of the thermal atomic motions in micro- and nanocrystalline SiC. Limitations of application of this method to examination of complex materials with atoms vibrating with more that one amplitude were discussed. It is shown that a unique interpretation of Wilson plots for crystals with more than one type of atoms and weak vibration component(s) requires measurements performed up to a very large diffraction vector Q (> 25 angstrom(-1)). Atomic vibrations in microcrystalline SiC were evaluated based on the diffractograms calculated for models built assuming different mean square atomic displacements (vibration amplitudes) of the component atoms. For nanocrystalline SiC two different temperature atomic factors which describe vibrations of the atoms in the grain interior (B-core) and at its surface (B-shell) were determined. C1 UNIPRESS, Inst High Pressure Phys, PL-01142 Warsaw, Poland. Los Alamos Neutron Sci Ctr, Los Alamos, NM 87545 USA. Texas Christian Univ, Ft Worth, TX 76129 USA. NASA, Marshall Space Flight Ctr, BAE Syst, Huntsville, AL 35812 USA. RP Stelmakh, S (reprint author), UNIPRESS, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland. EM svrit@unipress.waw.pl RI Lujan Center, LANL/G-4896-2012; Wojdyr, Marcin/N-5686-2015; Proffen, Thomas/B-3585-2009; OI Wojdyr, Marcin/0000-0003-3980-4092; Proffen, Thomas/0000-0002-1408-6031; Vogel, Sven C./0000-0003-2049-0361 NR 22 TC 2 Z9 2 U1 0 U2 1 PU WALTER DE GRUYTER GMBH PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0044-2968 J9 Z KRISTALLOGR JI Z. Kristall. PY 2007 VL 222 IS 3-4 BP 174 EP 185 DI 10.1524/zkri.2007.222.3-4.174 PG 12 WC Crystallography SC Crystallography GA 150DD UT WOS:000245194900008 ER PT J AU Johnson, JR Grundy, WM Lemmon, MT Bell, JF Johnson, MJ Deen, R Arvidson, RE Farrand, WH Guinness, E Hayes, AG Herkenhoff, KE Seelos, F Soderblom, J Squyres, S AF Johnson, Jeffrey R. Grundy, William M. Lemmon, Mark T. Bell, James F., III Johnson, Miles J. Deen, Robert Arvidson, R. E. Farrand, W. H. Guinness, E. Hayes, Alexander G. Herkenhoff, K. E. Seelos, F. Soderblom, J. Squyres, S. TI Spectrophotometric properties of materials observed by Pancam on the Mars Exploration Rovers: 2. Opportunity SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MERIDIANI-PLANUM; PHOTOMETRIC PROPERTIES; MARTIAN ATMOSPHERE; LIGHT-SCATTERING; BURNS FORMATION; SURFACE; DUST; SOIL; PATHFINDER; PARTICLES AB The Panoramic Camera (Pancam) on the Mars Exploration Rover Opportunity acquired visible/near-infrared multispectral observations of soils and rocks under varying viewing and illumination geometries that were modeled using radiative transfer theory to improve interpretations of the microphysical and surface scattering nature of materials in Meridiani Planum. Nearly 25,000 individual measurements were collected of rock and soil units identified by their color and morphologic properties over a wide range of phase angles (0-150 degrees) at Eagle crater, in the surrounding plains, in Endurance crater, and in the plains between Endurance and Erebus craters through Sol 492. Corrections for diffuse skylight incorporated sky models based on observations of atmospheric opacity throughout the mission. Disparity maps created from Pancam stereo images allowed inclusion of local facet orientation estimates. Outcrop rocks overall exhibited the highest single scattering albedos (<= 0.9 at 753 nm), and most spherule-rich soils exhibited the lowest (<= 0.6 at 753 nm). Macroscopic roughness among outcrop rocks varied but was typically larger than spherule-rich soils. Data sets with sufficient phase angle coverage (resulting in well-constrained Hapke parameters) suggested that models using single-term and two-term Henyey-Greenstein phase functions exhibit a dominantly broad backscattering trend for most undisturbed spherule-rich soils. Rover tracks and other compressed soils exhibited forward scattering, while outcrop rocks were intermediate in their scattering behaviors. Some phase functions exhibited wavelength-dependent trends that may result from variations in thin deposits of airfall dust that occurred during the mission. C1 US Geol Survey, Astrogeol Team, Flagstaff, AZ 86004 USA. Lowell Observ, Flagstaff, AZ 86001 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Space Sci Inst, Boulder, CO 80301 USA. MIT, Lincoln Lab, Boston, MA 02139 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 21218 USA. RP Johnson, JR (reprint author), US Geol Survey, Astrogeol Team, 2255 N Gemini Dr, Flagstaff, AZ 86004 USA. EM jrjohnson@usgs.gov RI Lemmon, Mark/E-9983-2010; Hayes, Alexander/P-2024-2014; Johnson, Jeffrey/F-3972-2015; Seelos, Frank/C-7875-2016; OI Lemmon, Mark/0000-0002-4504-5136; Hayes, Alexander/0000-0001-6397-2630; Seelos, Frank/0000-0001-9721-941X; Soderblom, Jason/0000-0003-3715-6407 NR 44 TC 17 Z9 17 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 30 PY 2006 VL 111 IS E12 AR E12S16 DI 10.1029/2006JE002762 PG 39 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 124DE UT WOS:000243346700002 ER PT J AU Morris, RV Klingelhofer, G Schroder, C Rodionov, DS Yen, A Ming, DW de Souza, PA Wdowiak, T Fleischer, I Gellert, R Bernhardt, B Bonnes, U Cohen, BA Evlanov, EN Foh, J Gutlich, P Kankeleit, E McCoy, T Mittlefehldt, DW Renz, F Schmidt, ME Zubkov, B Squyres, SW Arvidson, RE AF Morris, R. V. Klingelhoefer, G. Schroeder, C. Rodionov, D. S. Yen, A. Ming, D. W. de Souza, P. A., Jr. Wdowiak, T. Fleischer, I. Gellert, R. Bernhardt, B. Bonnes, U. Cohen, B. A. Evlanov, E. N. Foh, J. Guetlich, P. Kankeleit, E. McCoy, T. Mittlefehldt, D. W. Renz, F. Schmidt, M. E. Zubkov, B. Squyres, S. W. Arvidson, R. E. TI Mossbauer mineralogy of rock, soil, and dust at Meridiani Planum, Mars: Opportunity's journey across sulfate-rich outcrop, basaltic sand and dust, and hematite lag deposits SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MINI-TES EXPERIMENT; X-RAY SPECTROMETER; EXPLORATION ROVERS; ATMOSPHERIC DUST; 1ST SHERGOTTITE; SPIRIT ROVER; GUSEV CRATER; BOUNCE ROCK; JAROSITE; SURFACE AB The Mossbauer (MB) spectrometer on Opportunity measured the Fe oxidation state, identified Fe-bearing phases, and measured relative abundances of Fe among those phases at Meridiani Planum, Mars. Eight Fe-bearing phases were identified: jarosite (K,Na,H3O)(Fe,Al)(OH)(6)(SO4)(2), hematite, olivine, pyroxene, magnetite, nanophase ferric oxides (npOx), an unassigned ferric phase, and metallic Fe (kamacite). Burns Formation outcrop rocks consist of hematite-rich spherules dispersed throughout S-rich rock that has nearly constant proportions of Fe3+ from jarosite, hematite, and npOx (29%, 36%, and 20% of total Fe). The high oxidation state of the S-rich rock (Fe3+/Fe-T similar to 0.9) implies that S is present as the sulfate anion. Jarosite is mineralogical evidence for aqueous processes under acid-sulfate conditions because it has structural hydroxide and sulfate and it forms at low pH. Hematite-rich spherules, eroded from the outcrop, and their fragments are concentrated as hematite-rich soils (lag deposits) on ripple crests (up to 68% of total Fe from hematite). Olivine, pyroxene, and magnetite are primarily associated with basaltic soils and are present as thin and locally discontinuous cover over outcrop rocks, commonly forming aeolian bedforms. Basaltic soils are more reduced (Fe3+/Fe-T similar to 0.2-0.4), with the fine-grained and bright aeolian deposits being the most oxidized. Average proportions of total Fe from olivine, pyroxene, npOx, magnetite, and hematite are similar to 33%, 38%, 18%, 6%, and 4%, respectively. The MB parameters of outcrop npOx and basaltic-soil npOx are different, but it is not possible to infer mineralogical information beyond octahedrally coordinated Fe3+. Basaltic soils at Meridiani Planum and Gusev crater have similar Fe-mineralogical compositions. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Johannes Gutenberg Univ Mainz, Inst Anorgan & Analyt Chem, D-55099 Mainz, Germany. Space Res Inst IKI, Moscow 117997, Russia. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CVRD Grp, Rio De Janeiro, Brazil. Univ Alabama Birmingham, Dept Phys, Birmingham, AL 35294 USA. Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. Tech Univ Darmstadt, D-64289 Darmstadt, Germany. Univ New Mexico, Inst Meteorit, Albuquerque, NM 87131 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. RP Morris, RV (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code KR, Houston, TX 77058 USA. EM richard.v.morris@nasa.gov RI de Souza, Paulo/B-8961-2008; Schroder, Christian/B-3870-2009 OI de Souza, Paulo/0000-0002-0091-8925; Schroder, Christian/0000-0002-7935-6039 NR 75 TC 105 Z9 105 U1 2 U2 41 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 30 PY 2006 VL 111 IS E12 AR E12S15 DI 10.1029/2006JE002791 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 124DE UT WOS:000243346700004 ER PT J AU Ruff, SW Christensen, PR Blaney, DL Farrand, WH Johnson, JR Michalski, JR Moersch, JE Wright, SP Squyres, SW AF Ruff, S. W. Christensen, P. R. Blaney, D. L. Farrand, W. H. Johnson, J. R. Michalski, J. R. Moersch, J. E. Wright, S. P. Squyres, S. W. TI The rocks of Gusev Crater as viewed by the Mini-TES instrument SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID THERMAL EMISSION-SPECTROSCOPY; MARS EXPLORATION ROVERS; SPIRIT ROVER; MERIDIANI-PLANUM; MARTIAN SURFACE; BASALTIC ROCKS; MOSSBAUER SPECTROMETER; INFRARED-SPECTROSCOPY; PARTICLE-SIZE; MGS-TES AB The Miniature Thermal Emission Spectrometer (Mini-TES) on board the Mars Exploration Rover Spirit is part of a payload designed to investigate whether a lake once existed in Gusev Crater. Mini-TES has observed hundreds of rocks along the rover's traverse into the Columbia Hills, yielding information on their distribution, bulk mineralogy, and the potential role of water at the site. Although dust in various forms produces contributions to the spectra, we have established techniques for dealing with it. All of the rocks encountered on the plains traverse from the lander to the base of the Columbia Hills share common spectral features consistent with an olivine-rich basaltic rock known as Adirondack Class. Beginning at the base of the West Spur of the Columbia Hills and across its length, the rocks are spectrally distinct from the plains but can be grouped into a common type called Clovis Class. These rocks, some of which appear as in-place outcrop, are dominated by a component whose spectral character is consistent with unaltered basaltic glass despite evidence from other rover instruments for significant alteration. The northwest flank of Husband Hill is covered in float rocks known as Wishstone Class with spectral features that can be attributed uniquely to plagioclase feldspar, a phase that represents more than half of the bulk mineralogy. Rare exceptions are three classes of basaltic "exotics" found scattered across Husband Hill that may represent impact ejecta and/or float derived from local intrusions within the hills. The rare outcrops observed on Husband Hill display distinctive spectral characteristics. The outcrop called Peace shows a feature attributable to molecular bound water, and the outcrop that hosts the rock called Watchtower displays a dominant basaltic glass component. Despite evidence from the rover's payload for significant alteration of some of the rocks, no unambiguous detection of crystalline phyllosilicates or other secondary silicates has been observed by Mini-TES. The mineralogical results supplied by Mini-TES provide no clear evidence that a lake once existed in Gusev Crater. C1 Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Space Sci Inst, Boulder, CO 80301 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. Cornell Univ, Dept Astron, Ithaca, NY USA. RP Ruff, SW (reprint author), Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. EM steve.ruff@asu.edu RI Moersch, Jeffrey/F-7189-2010; Johnson, Jeffrey/F-3972-2015 NR 73 TC 74 Z9 74 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 30 PY 2006 VL 111 IS E12 AR E12S18 DI 10.1029/2006JE002747 PG 36 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 124DE UT WOS:000243346700001 ER PT J AU Wolff, MJ Smith, MD Clancy, RT Spanovich, N Whitney, BA Lemmon, MT Bandfield, JL Banfield, D Ghosh, A Landis, G Christensen, PR Bell, JF Squyres, SW AF Wolff, M. J. Smith, M. D. Clancy, R. T. Spanovich, N. Whitney, B. A. Lemmon, M. T. Bandfield, J. L. Banfield, D. Ghosh, A. Landis, G. Christensen, P. R. Bell, J. F., III Squyres, S. W. TI Constraints on dust aerosols from the Mars Exploration Rovers using MGS overflights and Mini-TES SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID THERMAL EMISSION SPECTROMETER; MARTIAN ATMOSPHERE; WATER-VAPOR; SURFACE; SCATTERING; VIKING; OPPORTUNITY; PATHFINDER; MINERALOGY; MERIDIANI AB Overflights of the Mars Exploration Rovers (MER) by the Mars Global Surveyor (MGS) provide a unique opportunity to examine some of the basic properties of dust aerosols, starting with one of the most fundamental, the indices of refraction (m = n + ik) in the infrared. The upward-viewing geometry of the Miniature Thermal Emission Spectrometer (Mini-TES) and the combined contemporaneous observations from both MER and MGS are powerful tools. Their use allows atmospheric retrievals to directly determine n and k while offering constraints for the menagerie of other radiative transfer input parameters. We exploit these coordinated observing campaigns, along additional data sources, to carry out series of radiative transfer analyses that ultimately return the set of refractive indices. We apply the resulting m to a larger sample of Mini-TES data to both further validate our approach and retrieve several other aerosol properties, including dust optical depth, dust size, and a measure of the vertical mixing profile. We find good agreement with the empirical approach of Smith et al. (2006), in terms of both the optical depths themselves and the frequency dependence of their extinction cross section and single scattering albedo. The retrieved dust sizes vary from near 1.3 mu m to 1.8 mu m within the selected sample, with a precision estimated to be similar or equal to 0.1-0.2 mu m. The vertical mixing profile evolves from well-mixed to appreciably confined by L-S similar to 30 degrees. For Spirit (MER-A), there is an abrupt transition back to a more well- mixed vertical profile with the onset of regional dust activity at L-S similar to 140 degrees. We discuss the lack of a definitive detection of water ice clouds in Mini-TES observations and the potential effects of vertical gradients in particle size distribution. Finally, as part of coordinated overflight analyses, an atmospherically corrected TES Lambert albedo map is derived and presented in Appendix A. C1 Space Sci Inst, Boulder, CO 80301 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN USA. NASA, Photovoltaics & Space Environm Branch, John Glenn Res Ctr, Cleveland, OH 44135 USA. RP Wolff, MJ (reprint author), Space Sci Inst, 4750 Walnut St,Suite 205,UCB 564, Boulder, CO 80301 USA. EM wolff@spacescience.org RI Lemmon, Mark/E-9983-2010; Smith, Michael/C-8875-2012; OI Lemmon, Mark/0000-0002-4504-5136; Banfield, Don/0000-0003-2664-0164 NR 51 TC 76 Z9 77 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 30 PY 2006 VL 111 IS E12 AR E12S17 DI 10.1029/2006JE002786 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 124DE UT WOS:000243346700003 ER PT J AU Garrigues, S Allard, D Baret, F Weiss, M AF Garrigues, S. Allard, D. Baret, F. Weiss, M. TI Influence of landscape spatial heterogeneity on the non-linear estimation of leaf area index from moderate spatial resolution remote sensing data SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE scaling bias; spatial heterogeneity; non-linearity; leaf area index; moderate resolution remote sensing data; transfer function; variogram; dispersion variance ID CANOPY BIOPHYSICAL VARIABLES; VEGETATION INDEXES; SATELLITE DATA; MODELS; REFLECTANCE; SCALE; VALIDATION; UNCERTAINTY; ALGORITHMS; FLUXES AB The monitoring of earth surface dynamic processes requires global observations of the structure and the functioning of vegetation. Moderate resolution sensors (with pixel size ranging from 250 in to 7 km) provide frequent estimates of biophysical variables to characterize vegetation such as the leaf area index (LAI). However, the computation of LAI from moderate resolution remote sensing data induces a scaling bias on the LAI estimate if the moderate resolution pixel is heterogeneous and if the transfer function that relates remote sensing data to LAI is non-linear. This study provides a model to evaluate and correct the scaling bias. The model is built first for a univariate semi-empirical transfer function relating LAI directly to NDVI. The scaling bias is a function of (i) the degree of non-linearity of the transfer function quantified by its second derivative and (ii) the spatial heterogeneity of the moderate resolution pixel quantified by the variogram of the high spatial resolution (20 in) NDVI image. Then, the model is extended to a bivariate transfer function where LAI is related to red and near infrared reflectances. The scaling bias depends on (i) the Hessian matrix of the transfer function and (ii) the variograms and cross variogram of the red and near infrared reflectances. The scaling bias is investigated on several distinct landscapes from the VALERI database. Adjusting for scaling bias is critical on crop sites which are the most heterogeneous sites at the landscape level. Regarding the univariate transfer function, the magnitude of the scaling bias increases rapidly with pixel size until this size is larger than the typical spatial scale of the data. For the bivariate transfer function, it results from the addition of several components that may add up or cancel each other out. It is thus more difficult to analyze. The accuracy of the model to estimate the scaling bias is discussed. It depends mainly on the ability of the variograms and cross variogram to represent the local dispersion variances and covariance within the moderate resolution pixel. The model is generally highly accurate at 1000 in spatial resolution for the univariate transfer function and less accurate for the bivariate transfer function. (c) 2006 Elsevier Inc. All rights reserved. C1 Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. INRA, Avignon, France. Noveltis, Toulouse, France. RP Garrigues, S (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM Sebastien.ganigues@gsfc.nasa.gov RI Baret, Fred/C-4135-2011; OI Baret, Fred/0000-0002-7655-8997; Weiss, Marie/0000-0002-2341-667X NR 36 TC 68 Z9 82 U1 4 U2 21 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD DEC 30 PY 2006 VL 105 IS 4 BP 286 EP 298 DI 10.1016/j.rse.2006.07.013 PG 13 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 114XP UT WOS:000242699200002 ER PT J AU Yeh, PJF Swenson, SC Famiglietti, JS Rodell, M AF Yeh, Pat J. -F. Swenson, S. C. Famiglietti, J. S. Rodell, M. TI Remote sensing of groundwater storage changes in Illinois using the Gravity Recovery and Climate Experiment (GRACE) SO WATER RESOURCES RESEARCH LA English DT Article ID CONTINENTAL WATER STORAGE; SOIL-MOISTURE; BALANCE; EVAPOTRANSPIRATION; VARIABILITY; AQUIFER; SYSTEM; FIELD AB Regional groundwater storage changes in Illinois are estimated from monthly GRACE total water storage change (TWSC) data and in situ measurements of soil moisture for the period 2002-2005. Groundwater storage change estimates are compared to those derived from the soil moisture and available well level data. The seasonal pattern and amplitude of GRACE-estimated groundwater storage changes track those of the in situ measurements reasonably well, although substantial differences exist in month-to-month variations. The seasonal cycle of GRACE TWSC agrees well with observations (correlation coefficient = 0.83), while the seasonal cycle of GRACE-based estimates of groundwater storage changes beneath 2 m depth agrees with observations with a correlation coefficient of 0.63. We conclude that the GRACE-based method of estimating monthly to seasonal groundwater storage changes performs reasonably well at the 200,000 km(2) scale of Illinois. C1 Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Yeh, PJF (reprint author), Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. EM jfamigli@uci.edu RI YEH, Pat/B-2758-2011; Rodell, Matthew/E-4946-2012 OI YEH, Pat/0000-0001-7629-3362; Rodell, Matthew/0000-0003-0106-7437 NR 29 TC 109 Z9 109 U1 4 U2 41 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 EI 1944-7973 J9 WATER RESOUR RES JI Water Resour. Res. PD DEC 29 PY 2006 VL 42 IS 12 AR W12203 DI 10.1029/2006WR005374 PG 7 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 124EG UT WOS:000243349700002 ER PT J AU Jacobson, MZ Kaufman, YJ AF Jacobson, Mark Z. Kaufman, Yoram J. TI Wind reduction by aerosol particles SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AIR-POLLUTION; BOUNDARY-LAYER; FOSSIL-FUEL; SEA-ICE; URBAN; SNOW; SUPPRESSION; DISTRIBUTIONS; MODEL AB Aerosol particles are known to affect radiation, temperatures, stability, clouds, and precipitation, but their effects on spatially-distributed wind speed have not been examined to date. Here, it is found that aerosol particles, directly and through their enhancement of clouds, may reduce near-surface wind speeds below them by up to 8% locally. This reduction may explain a portion of observed "disappearing winds'' in China, and it decreases the energy available for wind-turbine electricity. In California, slower winds reduce emissions of wind-driven soil dust and sea spray. Slower winds and cooler surface temperatures also reduce moisture advection and evaporation. These factors, along with the second indirect aerosol effect, may reduce California precipitation by 2 - 5%, contributing to a strain on water supply. C1 Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Jacobson, MZ (reprint author), Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. EM jacobson@stanford.edu NR 28 TC 52 Z9 57 U1 2 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 27 PY 2006 VL 33 IS 24 AR L24814 DI 10.1029/2006GL027838 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 124CA UT WOS:000243343500003 ER PT J AU Shindell, DT Faluvegi, G Miller, RL Schmidt, GA Hansen, JE Sun, S AF Shindell, Drew T. Faluvegi, Greg Miller, Ron L. Schmidt, Gavin A. Hansen, James E. Sun, Shan TI Solar and anthropogenic forcing of tropical hydrology SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAUNDER MINIMUM; CLIMATE-CHANGE; HOLOCENE; MONSOON; VARIABILITY; PACIFIC; CYCLE; SIMULATIONS; CIRCULATION; IRRADIANCE AB Holocene climate proxies suggest substantial correlations between tropical meteorology and solar variations, but these have thus far not been explained. Using a coupled ocean-atmosphere-composition model forced by sustained multi-decadal irradiance increases, we show that greater tropical temperatures alter the hydrologic cycle, enhancing the climatological precipitation maxima in the tropics while drying the subtropical subsidence regions. The shift is enhanced by tropopause region ozone increases, and the model captures the pattern inferred from paleoclimate records. The physical process we describe likely affected past civilizations, including the Maya, Moche, and Ancestral Puebloans who experienced drought coincident with increased irradiance during the late medieval ( similar to 900 - 1250). Similarly, decreased irradiance may have affected cultures via a weakened monsoon during the Little Ice Age ( similar to 1400 - 1750). Projections of 21st-century climate change yield hydrologic cycle changes via similar processes, suggesting a strong likelihood of increased subtropical drought as climate warms. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Earth Inst, New York, NY USA. RP Shindell, DT (reprint author), NASA, Goddard Inst Space Studies, 288 Broadway, New York, NY 10025 USA. EM dshindell@giss.nasa.gov RI Shindell, Drew/D-4636-2012; Schmidt, Gavin/D-4427-2012; Miller, Ron/E-1902-2012; Sun, Shan/H-2318-2015 OI Schmidt, Gavin/0000-0002-2258-0486; NR 33 TC 65 Z9 67 U1 1 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 27 PY 2006 VL 33 IS 24 AR L24706 DI 10.1029/2006GL027468 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 124CA UT WOS:000243343500001 ER PT J AU Kuzmic, M Janekovic, I Book, JW Martin, PJ Doyle, JD AF Kuzmic, Milivoj Janekovic, Ivica Book, Jeffrey W. Martin, Paul J. Doyle, James D. TI Modeling the northern Adriatic double-gyre response to intense bora wind: A revisit SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA; CIRCULATION; HYDRODYNAMICS; SIMULATION; PREDICTION; BOTTOM; WATER; GULF; BURA AB [ 1] A combination of recent intensive observations and simulations with two numerical models is used to revisit the issue of the northern Adriatic response to strong bora episodes. New observed and simulated data reinforce the view that an episode of strong bora wind provokes a double-gyre ( cyclonic, Trieste, and anticyclonic, Rovinj) response north of the Po Delta - Pula line. During an intense bora episode, both measured and modeled statistics picture a downwind, highly polarized, and almost depth-independent flow within the Trieste gyre NW arm. Its NE arm maintains a sharp polarization and strong depth dependence while exhibiting lower speeds, with models in good accord with observations. The current statistics for Rovinj gyre provide lower maximum and average speed values and less polarized but still rather depth-independent flow, while exhibiting clockwise rotation. The north arm of the Senj gyre ( positioned south of the Po Delta - Pula line) enjoys more lateral freedom, and exhibits less rectilinear flow. Our review reinforces the notion that modeling studies based on ECMWF wind forcing fail to properly take into account the orographic control of the Dinaric Alps, and to produce correct bora-induced gyral pattern. The COAMPS 1 model successfully simulated the onset, duration, and decay of the wind peaks, but exhibited a tendency to overpredict the strength of the bora wind. Our simulations have identified the shallow NW coastal strip as an important source of colder water observed in a sequence of remotely sensed SST fields derived from AVHRR data. C1 Rudjer Boskovic Inst, Ctr Marine & Environm Res, Zagreb 10002, Croatia. USN, Res Lab, Stennis Space Ctr, Div Oceanog, Stennis Space Ctr, MS 39529 USA. USN, Res Lab, Marine Meteorol Div, Monterey, CA 93943 USA. RP Kuzmic, M (reprint author), Rudjer Boskovic Inst, Ctr Marine & Environm Res, POB 180, Zagreb 10002, Croatia. EM kuzmic@rudjer.irb.hr RI Janekovic, Ivica/N-7639-2013 NR 56 TC 37 Z9 37 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 27 PY 2006 VL 111 IS C3 AR C03S13 DI 10.1029/2005JC003377 PG 27 WC Oceanography SC Oceanography GA 133UY UT WOS:000244040600001 ER PT J AU Ominami, Y Ngo, Q Suzuki, M Austin, AJ Yang, CY Cassell, AM Li, J AF Ominami, Yusuke Ngo, Quoc Suzuki, Makoto Austin, Alexander J. Yang, Cary Y. Cassell, Alan M. Li, Jun TI Interface characteristics of vertically aligned carbon nanofibers for interconnect applications SO APPLIED PHYSICS LETTERS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; NANOTUBES; GROWTH; TRANSPORT; ARRAYS AB The authors characterize the detailed interface structure of Ni-catalyzed vertically aligned carbon nanofibers (CNFs) prepared by plasma-enhanced chemical vapor deposition for interconnect applications. Stacked graphitic layers and cup-shape structures of CNFs around the interface region have been observed using high-resolution scanning transmission electron microscopy. The interaction between the Ni catalyst and Ti layer dramatically affects the CNF structure during initial growth. The effect of interface nanostructures on contact resistance is also discussed. (c) 2006 American Institute of Physics. C1 Santa Clara Univ, Ctr Nanostruct, Santa Clara, CA 95053 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Yang, CY (reprint author), Santa Clara Univ, Ctr Nanostruct, 500 El Camino Real, Santa Clara, CA 95053 USA. EM cyang@scu.edu RI Li, Jun/H-7771-2013 OI Li, Jun/0000-0002-3689-8946 NR 17 TC 8 Z9 8 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 25 PY 2006 VL 89 IS 26 AR 263114 DI 10.1063/1.2423241 PG 3 WC Physics, Applied SC Physics GA 121KX UT WOS:000243157600095 ER PT J AU Verronen, PT Seppala, A Kyrola, E Tamminen, J Pickett, HM Turunen, E AF Verronen, Pekka T. Seppala, Annika Kyrola, Erkki Tamminen, Johanna Pickett, Herbert M. Turunen, Esa TI Production of odd hydrogen in the mesosphere during the January 2005 solar proton event SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Using measurements from the MLS/Aura and GOMOS/Envisat instruments together with a 1-D ion and neutral chemistry model we study the changes in odd hydrogen and ozone in the mesosphere during the January 2005 solar proton event. The unique observational data allow us for the first time to directly test the HOx production theory which involves complex ion chemistry. MLS measurements from the northern polar region show increases of OH concentrations by over 100% around the stratopause, and by up to one order of magnitude in the middle mesosphere after the onset of the SPE. GOMOS measurements indicate decreases in O-3 concentration throughout the lower and middle mesosphere, by up to 90%. The model predictions are in reasonable agreement with the observations. We point out that models using the so-called P-HOx/Q parameterization to include the effects of ion chemistry could underestimate the HOx production and the resulting ozone depletion. C1 Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Oulu, Sodankyla Geophys Observ, FIN-99600 Sodankyla, Finland. RP Verronen, PT (reprint author), Finnish Meteorol Inst, POB 503,Erik Palmenin Aukio 1, FIN-00101 Helsinki, Finland. EM pekka.verronen@fmi.fi; herbert.m.pickett@jpl.nasa.gov; esa.turunen@sgo.fi RI Seppala, Annika/C-8031-2014; Tamminen, Johanna/D-7959-2014; Kyrola, Erkki/E-1835-2014; Verronen, Pekka/G-6658-2014 OI Seppala, Annika/0000-0002-5028-8220; Tamminen, Johanna/0000-0003-3095-0069; Verronen, Pekka/0000-0002-3479-9071 NR 14 TC 51 Z9 51 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 22 PY 2006 VL 33 IS 24 AR L24811 DI 10.1029/2006GL028115 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 120SM UT WOS:000243106200007 ER PT J AU Kulawik, SS Worden, J Eldering, A Bowman, K Gunson, M Osterman, GB Zhang, L Clough, SA Shephard, MW Beer, R AF Kulawik, Susan S. Worden, John Eldering, Annmarie Bowman, Kevin Gunson, Michael Osterman, Gregory B. Zhang, Lin Clough, Shepard A. Shephard, Mark W. Beer, Reinhard TI Implementation of cloud retrievals for Tropospheric Emission Spectrometer (TES) atmospheric retrievals: part 1. Description and characterization of errors on trace gas retrievals SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR; MODIS; MODEL; AIRS/AMSU/HSB; TEMPERATURE; OBJECTIVES; PROFILES; PRODUCTS; AEROSOL; MISSION AB We develop an approach to estimate and characterize trace gas retrievals in the presence of clouds in high spectral measurements of upwelling radiance in the infrared spectral region (650-2260 cm(-1)). The radiance contribution of clouds is parameterized in terms of a set of frequency-dependent nonscattering optical depths and a cloud height. These cloud parameters are retrieved jointly with surface temperature, emissivity, atmospheric temperature, and trace gases such as ozone from spectral data. We demonstrate the application of this approach using data from the Tropospheric Emission Spectrometer (TES) and test data simulated with a scattering radiative transfer model. We show the value of this approach in that it results in accurate estimates of errors for trace gas retrievals, and the retrieved values improve over the initial guess for a wide range of cloud conditions. Comparisons are made between TES retrievals of ozone, temperature, and water to model fields from the Global Modeling and Assimilation Office (GMAO), temperature retrievals from the Atmospheric Infrared Sounder (AIRS), tropospheric ozone columns from the Goddard Earth Observing System (GEOS) GEOS-Chem, and ozone retrievals from the Total Ozone Mapping Spectrometer (TOMS). In each of these cases, this cloud retrieval approach does not introduce observable biases into TES retrievals. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Atmospher & Environm Res Inc, Lexington, MA 02421 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. RP Kulawik, SS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM susan.s.kulawik@jpl.nasa.gov RI Zhang, Lin/A-6729-2008; Zhang, Lin/H-9801-2014; Chem, GEOS/C-5595-2014 OI Zhang, Lin/0000-0003-2383-8431; NR 25 TC 63 Z9 63 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 22 PY 2006 VL 111 IS D24 AR D24204 DI 10.1029/2005JD006733 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120SW UT WOS:000243107300002 ER PT J AU Cohen, MB Inan, US Fishman, G AF Cohen, M. B. Inan, U. S. Fishman, G. TI Terrestrial gamma ray flashes observed aboard the compton gamma ray observatory/burst and transient source experiment and ELF/VLF radio atmospherics SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SFERIC MEASUREMENTS; THUNDERCLOUD; SPRITES; BURSTS; JETS AB [1] During its 9-year lifetime in orbit, the Burst and Transient Source Experiment (BATSE) detector, aboard the Compton Gamma Ray Observatory (CGRO) spacecraft, observed a total of 76 terrestrial gamma ray flashes (TGFs). Of these, simultaneous broadband ELF/VLF data from Palmer Station, Antarctica, were found to be available for six new TGF cases in addition to two previously reported cases (Inan et al., 1996). Analysis of temporal and directional association between radio atmospherics and TGFs reveals solid evidence of an associated radio atmospheric in three of the six events. In one of the three cases with associated radio atmospherics, three consecutive TGFs are apparently linked to three consecutive radio atmospherics. A fourth case exhibits possible evidence of geomagnetically conjugate source lightning. Statistical analyses indicate that when TGFs occur in association with a lightning discharge, they occur similar to 1 - 3 ms after the causative lightning event. C1 Stanford Univ, Space Telecommun & Radiosci Lab, Stanford, CA 94305 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Cohen, MB (reprint author), Stanford Univ, Space Telecommun & Radiosci Lab, 350 Serra Hall, Stanford, CA 94305 USA. EM mcohen@stanford.edu RI Cohen, Morris/A-3684-2012 OI Cohen, Morris/0000-0002-7920-5759 NR 19 TC 37 Z9 38 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 21 PY 2006 VL 111 IS D24 AR D24109 DI 10.1029/2005JD006987 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120SV UT WOS:000243107100001 ER PT J AU Gehrels, N Norris, JP Barthelmy, SD Granot, J Kaneko, Y Kouveliotou, C Markwardt, CB Meszaros, P Nakar, E Nousek, JA O'Brien, PT Page, M Palmer, DM Parsons, AM Roming, PWA Sakamoto, T Sarazin, CL Schady, P Stamatikos, M Woosley, SE AF Gehrels, N. Norris, J. P. Barthelmy, S. D. Granot, J. Kaneko, Y. Kouveliotou, C. Markwardt, C. B. Meszaros, P. Nakar, E. Nousek, J. A. O'Brien, P. T. Page, M. Palmer, D. M. Parsons, A. M. Roming, P. W. A. Sakamoto, T. Sarazin, C. L. Schady, P. Stamatikos, M. Woosley, S. E. TI A new gamma-ray burst classification scheme from GRB 060614 SO NATURE LA English DT Article ID HOST GALAXY; GRB-050709; AFTERGLOW AB Gamma-ray bursts (GRBs) are known to come in two duration classes(1), separated at similar to 2 s. Long-duration bursts originate from star-forming regions in galaxies(2), have accompanying supernovae when these are near enough to observe and are probably caused by massive-star collapsars(3). Recent observations(4-10) show that short-duration bursts originate in regions within their host galaxies that have lower star-formation rates, consistent with binary neutron star or neutron star - black hole mergers(11,12). Moreover, although their hosts are predominantly nearby galaxies, no supernovae have been so far associated with short-duration GRBs. Here we report that the bright, nearby GRB 060614 does not fit into either class. Its similar to 102-s duration groups it with long-duration GRBs, while its temporal lag and peak luminosity fall entirely within the short-duration GRB subclass. Moreover, very deep optical observations exclude an accompanying supernova(13-15), similar to short-duration GRBs. This combination of a long-duration event without an accompanying supernova poses a challenge to both the collapsar and the merging-neutron-star interpretations and opens the door to a new GRB classification scheme that straddles both long- and short-duration bursts. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Stanford Univ, KIPAC, Stanford, CA 94309 USA. NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. NSSTC, USRA, Huntsville, AL 35805 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. CALTECH, Pasadena, CA 91125 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Oak Ridge Associated Univ, Oak Ridge, TN 37831 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22904 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. RP Gehrels, N (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM gehrels@milkyway.gsfc.nasa.gov RI Barthelmy, Scott/D-2943-2012; Gehrels, Neil/D-2971-2012; Parsons, Ann/I-6604-2012 NR 27 TC 293 Z9 298 U1 1 U2 7 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 21 PY 2006 VL 444 IS 7122 BP 1044 EP 1046 DI 10.1038/nature05376 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 118VH UT WOS:000242971100048 PM 17183315 ER PT J AU Singal, J Fixsen, DJ Kogut, A Levin, S Limon, M Lubin, P Mirel, P Seiffert, M Wollack, EJ AF Singal, J. Fixsen, D. J. Kogut, A. Levin, S. Limon, M. Lubin, P. Mirel, P. Seiffert, M. Wollack, E. J. TI The cosmic microwave background temperature and galactic emission at 8.0 and 8.3 GHz SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; Galaxy : general; instrumentation : detectors ID RADIO-CONTINUUM SURVEY; 1420 MHZ; SKY; SPECTRUM; UNIVERSE AB We report balloon-borne measurements at 8.0 and 8.3 GHz of Galactic emission and of the radiometric temperature of the cosmic microwave background, the results from the first flight of the ARCADE 2 (Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission) instrument. We find the Galactic free-free emission intensity in the plane to be two-thirds as high as that predicted by a naive extrapolation of 2003 WMAP K-band data, a result consistent with 2006 WMAP findings, and find the Galactic synchrotron emission intensity to be approximately as high as that predicted by a naive interpolation of Haslam all-sky survey and WMAP K-band data. We find T-CMB to be 2.90 +/- 0.12 K at 8.0 GHz and 2.77 +/- 0.16 K at 8.3 GHz. C1 Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Singal, J (reprint author), NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Code 665, Greenbelt, MD 20771 USA. RI Kogut, Alan/D-6293-2012; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Limon, Michele/0000-0002-5900-2698 NR 23 TC 8 Z9 8 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2006 VL 653 IS 2 BP 835 EP 842 DI 10.1086/508804 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118PW UT WOS:000242955200002 ER PT J AU Evans, DA Lee, JC Kamenetska, M Gallagher, SC Kraft, RP Hardcastle, MJ Weaver, KA AF Evans, Daniel A. Lee, Julia C. Kamenetska, Maria Gallagher, Sarah C. Kraft, Ralph P. Hardcastle, Martin J. Weaver, Kimberly A. TI The Chandra, Hubble Space Telescope, and VLA view of the circumnuclear extended emission in the narrow emission line galaxy NGC 2110 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 2110); galaxies : jets; galaxies : Seyfert ID X-RAY-EMISSION; ACTIVE GALACTIC NUCLEI; SEYFERT-GALAXIES; XMM-NEWTON; IONIZED-GAS; NGC 2110; NGC-1068; SPECTROSCOPY; SPECTRUM; IONIZATION AB present results from new Chandra, archival Hubble Space Telescope (HST), and VLA imaging observations of the circumnuclear extended emission in the nearby Type 2 Seyfert galaxy NGC 2110. We find resolved soft-band X-ray emission similar to 400" (similar to 160 pc) north of the nucleus, which is spatially coincident with [O III] emission, but lies just beyond the northern edge of the radio jet in the source. We find that shock heating of multiphase gas clouds can successfully account for this extended emission, although we cannot rule out alternative models, such as the scattering of nuclear radiation by ionized material, or pure photoionization from the nucleus. In addition, we detect kiloparsec-scale (similar to 30") extended soft-band X-ray emission south of the nucleus. Finally, we compare our results for NGC 2110 with the prototypical type 2 Seyfert galaxy NGC 1068, and suggest that different physical processes could produce extended circumnuclear X-ray emission in Seyfert galaxies. C1 Harvard Univ, Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. Univ Calif Los Angeles, Div Astron & Astrophys, Los Angeles, CA 90095 USA. Univ Hertfordshire, Sch Phys Astron & Math, Hatfield AL10 9AB, Herts, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Evans, DA (reprint author), Harvard Univ, Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Hardcastle, Martin/E-2264-2012; Lee, Julia/G-2381-2015 OI Hardcastle, Martin/0000-0003-4223-1117; Lee, Julia/0000-0002-7336-3588 NR 33 TC 24 Z9 24 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2006 VL 653 IS 2 BP 1121 EP 1128 DI 10.1086/508680 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118PW UT WOS:000242955200023 ER PT J AU Stanimirovic, S Putman, M Heiles, C Peek, JEG Goldsmith, PF Koo, BC Krco, M Lee, JJ Mock, J Muller, E Pandian, JD Parsons, A Tang, Y Werthimer, D AF Stanimirovic, Snezana Putman, Mary Heiles, Carl Peek, Joshua E. G. Goldsmith, Paul F. Koo, Bon-Chul Krco, Marko Lee, Jae-Joon Mock, Jeff Muller, Erik Pandian, Jagadheep D. Parsons, Aaron Tang, Yvonne Werthimer, Dan TI First results from the Arecibo Galactic H I survey: The disk/halo interface region in the outer Galaxy SO ASTROPHYSICAL JOURNAL LA English DT Article DE Galaxy : formation; Galaxy : halo; intergalactic medium; ISM : clouds; ISM : structure ID HIGH-VELOCITY CLOUDS; ABSORPTION-LINE SURVEY; FINAL DATA RELEASE; MILKY-WAY HALO; INTERSTELLAR-MEDIUM; ATOMIC-HYDROGEN; SPIRAL GALAXIES; PLANE SURVEY; GAS; COMPACT AB The consortium for Galactic studies with the Arecibo L-band Feed Array (ALFA) is conducting a neutral hydrogen (HI) survey of the whole Arecibo sky (declination range from -1 degrees to 38 degrees), with high angular (3.'5) and velocity resolution (0.2 km s(-1)). The precursor observations with ALFA of a region in the Galactic anticenter reveal numerous isolated, small (a few parsecs in size), and cold (T(k) < 400 K) H I clouds at low negative velocities, distinctly separated from the H I disk emission ('low-velocity clouds'' [ LVCs]). These clouds are most likely located in the transition region between the Galactic disk and halo (at scale heights of 60-900 pc), yet they have properties of typical cold neutral clouds. LVCs are colder and, most likely, smaller and less massive than Lockman's clouds in the disk/halo interface region of the inner Galaxy. Our observations demonstrate that the cloudy structure of the interface region is most likely a general phenomenon, not restricted to the inner Galaxy. LVCs have sizes and radial velocities in agreement with the expectations for clouds formed in low-temperature fountain flows, although we measure a factor of 10 higher H I column densities. Alternatively, LVCs could represent the final stages of the infalling intergalactic material in the ongoing construction of the Galaxy. In the same data set at higher negative velocities, we have discovered a "companion'' H I cloud located 50' southwest of HVC186+19-114. HVC 186+19-114 is a typical compact high-velocity cloud (HVC) with a well-defined core/envelope structure. The companion cloud has a diameter of only 70; 90 and is one of the smallest HVCs known, most likely stripped from the main cloud through the interactions with the halo medium. C1 Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Seoul Natl Univ, Dept Phys & Astron, Seoul 151742, South Korea. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. CSIRO, Australia Telescope Natl Facil, Epping, NSW 1710, Australia. RP Stanimirovic, S (reprint author), Univ Calif Berkeley, Radio Astron Lab, 601 Campbell Hall, Berkeley, CA 94720 USA. EM sstanimi@astro.berkeley.edu; mputman@umich.edu RI Goldsmith, Paul/H-3159-2016 NR 75 TC 49 Z9 49 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2006 VL 653 IS 2 BP 1210 EP 1225 DI 10.1086/508800 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118PW UT WOS:000242955200030 ER PT J AU Sahai, R Young, K Patel, NA Contreras, CS Morris, M AF Sahai, R. Young, K. Patel, N. A. Sanchez Contreras, C. Morris, M. TI A massive bipolar outflow and a dusty torus with large grains in the preplanetary nebula IRAS 22036+5306 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary nebulae : individual (IRAS 22036+5306) reflection nebulae; stars : AGB and post-AGB; stars : mass loss; stars : winds, outflows ID PLANETARY-NEBULAE; PROTOPLANETARY NEBULAE; GIANT BRANCH; MOLECULAR ENVELOPE; RED RECTANGLE; FROSTY-LEO; AGB STARS; JET; EMISSION; STELLAR AB We report high angular resolution (similar to 1") CO = 3-2 interferometric mapping using the Submillimeter Array (SMA) of IRAS 22036+5306 (I22036), a bipolar preplanetary nebula (PPN) with knotty jets discovered in our HST snapshot survey of young PPNs. In addition, we have obtained supporting lower resolution (similar to 10") CO and (CO)-C-13 J = 1-0 observations with the Owens Valley Radio Observatory (OVRO) interferometer, as well as optical long-slit echelle spectra at the Palomar Observatory. The CO J 3-2 observations show the presence of a very fast (similar to 220 km s(-1)), highly collimated, massive (0.03 M-circle dot) bipolar outflow with a very large scalar momentum (about 1039 g cm s(-1)), and the characteristic spatiokinematic structure of bow shocks at the tips of this outflow. The H alpha line shows an absorption feature blueshifted from the systemic velocity by similar to 100 km s(-1), which most likely arises in neutral interface material between the fast outflow and the dense walls of the bipolar lobes at low latitudes. The fast outflow in I22036, as in most PPNs, cannot be driven by radiation pressure. We find an unresolved source of submillimeter (and millimeterwave) continuum emission in I22036, implying a very substantial mass (0.02-0.04M(circle dot)) of large (radius greater than or similar to 1 mm), cold (less than or similar to 50 K) dust grains associated with I22036' s toroidal waist. We also find that the C-13/C-12 ratio in I22036 is very high (0.16), close to the maximum value achieved in equilibrium CNO nucleosynthesis (0.33). The combination of the high circumstellar mass (i.e.,in the extended dust shell and the torus) and the high C-13/12C ratio in I22036 provides strong support for this object having evolved from a massive (greater than or similar to 4 M-circle dot) progenitor in which hot- bottom- burning has occurred. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Phys & Astrophys, Div Astron, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sahai, R (reprint author), CSIC, Inst Estructura Mat, Dept Astrofis Mol & Infrarroja, Serrano 121, Madrid 28006, Spain. RI Sanchez-Contreras, Carmen/N-3718-2015 OI Sanchez-Contreras, Carmen/0000-0002-6341-592X NR 45 TC 24 Z9 24 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2006 VL 653 IS 2 BP 1241 EP 1252 DI 10.1086/508507 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118PW UT WOS:000242955200032 ER PT J AU Vijh, UP Witt, AN York, DG Dwarkadas, VV Woodgate, BE Palunas, P AF Vijh, Uma P. Witt, Adolf N. York, Donald G. Dwarkadas, Vikram V. Woodgate, Bruce E. Palunas, Povilas TI Optical emission band morphologies of the Red Rectangle SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; ISM : individual (Red Rectangle); ISM : molecules; radiation mechanisms : general; stars : individual (HD 44179) ID POLYCYCLIC AROMATIC-HYDROCARBONS; ORBITING GAS DISK; MOLECULAR-EMISSION; INFRARED-EMISSION; HD-44179; BINARY; NEBULA; SPECTROSCOPY; VARIABILITY; DISCOVERY AB We present narrowband images of the Red Rectangle (RR) Nebula that reveal the distinct morphologies of this intriguing nebula in different optical emission bands. The morphology of the RR nebula in blue luminescence (BL) and extended red emission (ERE) are almost mutually exclusive. We also present the optical detection of the circumbinary disk of the RR in the light of the BL. The total intensities from the two optical band emissions (BL and ERE) when summed over the nebula are of comparable magnitude. Their spatial distributions with respect to the embedded illumination sources lead us to suggest that they may be attributed to different ionization stages of the same family of carriers. C1 Univ Toledo, Ritter Astrophys Res Ctr, Toledo, OH 43606 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Texas, McDonald Observ, Austin, TX 78712 USA. RP Vijh, UP (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM vijh@stsci.edu; awitt@dusty.astro.utoledo.edu; don@oddjob.uchicago.edu; vikram@oddjob.uchicago.edu; woodgate@uit.gsfc.nasa.gov; palunas@astro.as.utexas.edu RI Woodgate, Bruce/D-2970-2012; OI Witt, Adolf/0000-0003-0760-4483 NR 28 TC 14 Z9 14 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2006 VL 653 IS 2 BP 1336 EP 1341 DI 10.1086/509061 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118PW UT WOS:000242955200039 ER PT J AU Morales-Calderon, M Stauffer, JR Kirkpatrick, JD Carey, S Gelino, CR Navascues, DBY Rebull, L Lowrance, P Marley, MS Charbonneau, D Patten, BM Megeath, ST Buzasi, D AF Morales-Calderon, M. Stauffer, J. R. Kirkpatrick, J. Davy Carey, S. Gelino, C. R. Navascues, D. Barrado y Rebull, L. Lowrance, P. Marley, M. S. Charbonneau, D. Patten, B. M. Megeath, S. T. Buzasi, D. TI A sensitive search for variability in late L dwarfs: The quest for weather SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : individual (DENIS-P J0255-4700, 2MASS J0908+5032; 2MASS J2244+2043); stars : low-mass, brown dwarfs; stars : variables : other ID TIME-SERIES OBSERVATIONS; SPITZER-SPACE-TELESCOPE; INFRARED ARRAY CAMERA; ULTRACOOL DWARFS; BROWN DWARFS; T-DWARFS; PHOTOMETRIC VARIABILITY; BAND VARIABILITY; COOL DWARFS; TRANSITION AB We have conducted a photometric monitoring program of three field late L brown dwarfs (DENIS-P J0255-4700, 2MASS J0908+5032, and 2MASS J2244+2043) looking for evidence of nonaxisymmetric structure or temporal variability in their photospheres. The observations were performed using Spitzer IRAC 4.5 and 8 mu m bandpasses and were designed to cover at least one rotational period of each object; 1 sigma rms uncertainties of less than 3 mmag at 4.5 mu m and around 9 mmag at 8 mu m were achieved. Two out of the three objects studied exhibit some modulation in their light curves at 4.5 mu m-but not 8 mu m-with periods of 7.4 hr (DENIS 0255) and 4.6 hr (2MA 2244) and peak-to-peak amplitudes of 10 and 8 mmag. Although the lack of detectable 8 mu m variation suggests an instrumental origin for the detected variations, the data may nevertheless still be consistent with intrinsic variability, since the shorter wavelength IRAC bandpasses probe more deeply into late L dwarf atmospheres than the longer wavelengths. A cloud feature occupying a small percentage (1%-2%) of the visible hemisphere could account for the observed amplitude of variation. If, instead, the variability is indeed instrumental in origin, then our nonvariable L dwarfs could be either completely covered with clouds or objects whose clouds are smaller and uniformly distributed. Such scenarios would lead to very small photometric variations. Follow-up IRAC photometry at 3.6 and 5.8 mu m bandpasses should distinguish between the two cases. In any event, the present observations provide the most sensitive search to date for structure in the photospheres of late L dwarfs at mid-IR wavelengths, and our photometry provides stringent upper limits to the extent to which the photospheres of these transition L dwarfs are structured. C1 INTA, LAEFF, E-28080 Madrid, Spain. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. USAF Acad, Colorado Springs, CO 80840 USA. RP Morales-Calderon, M (reprint author), INTA, LAEFF, POB 50727, E-28080 Madrid, Spain. EM mariamc@laeff.inta.es RI Marley, Mark/I-4704-2013; Barrado Navascues, David/C-1439-2017; Morales-Calderon, Maria/C-8384-2017; OI Barrado Navascues, David/0000-0002-5971-9242; Morales-Calderon, Maria/0000-0001-9526-9499; Rebull, Luisa/0000-0001-6381-515X NR 36 TC 63 Z9 63 U1 1 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2006 VL 653 IS 2 BP 1454 EP 1463 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118PW UT WOS:000242955200052 ER PT J AU Muterspaugh, MW Lane, BF Kulkarni, SR Burke, BF Colavita, MM Shao, M AF Muterspaugh, Matthew W. Lane, Benjamin F. Kulkarni, S. R. Burke, Bernard F. Colavita, M. M. Shao, M. TI Limits to tertiary astrometric companions in binary systems SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrometry; binaries : close; binaries : visual; methods : data analysis; planetary systems : formation ID PALOMAR TESTBED INTERFEROMETER; BETA-CORONAE BOREALIS; TRIPLE-STAR SYSTEM; DIFFERENTIAL ASTROMETRY; PLANET FORMATION; SPECKLE INTERFEROMETRY; GIANT PLANET; ORBITS; HD-188753 AB The Palomar High-precision Astrometric Search for Exoplanet Systems ( PHASES) has monitored 37 subarcsecond binary systems to determine whether their Keplerian orbits are perturbed by faint astrometric companions to either star. Software has been developed to evaluate the regions in a companion mass-period phase space in which the PHASES observations can exclude the possibility of face-on orbit perturbations. We present results for eight systems for which astrometric companions with masses as small as those of giant planets can be excluded. C1 CALTECH, Dept Geol & Planetary Sci, Pasadena, CA 91125 USA. MIT, Dept Phys, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Muterspaugh, MW (reprint author), CALTECH, Dept Geol & Planetary Sci, Pasadena, CA 91125 USA. NR 29 TC 13 Z9 13 U1 1 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2006 VL 653 IS 2 BP 1469 EP 1479 DI 10.1086/508743 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118PW UT WOS:000242955200054 ER PT J AU Baker, JG Centrella, J Choi, DI Koppitz, M van Meter, JR Miller, MC AF Baker, John G. Centrella, Joan Choi, Dae-Il Koppitz, Michael van Meter, James R. Miller, M. Coleman TI Getting a kick out of numerical relativity SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; cosmology : theory; gravitational waves; relativity ID MASS BLACK-HOLES; GRAVITATIONAL-RADIATION RECOIL; GLOBULAR-CLUSTERS; CIRCULAR ORBITS; BINARY-SYSTEMS; STAR-CLUSTERS; INITIAL DATA; DARK HALOES; EVOLUTION; GROWTH AB Recent developments in numerical relativity have made it possible to reliably follow the coalescence of two black holes from near the innermost stable circular orbit to final ringdown. This opens up a wide variety of exciting astrophysical applications of these simulations. Chief among these is the net kick received when two unequal mass or spinning black holes merge. The magnitude of this kick has bearing on the production and growth of supermassive black holes during the epoch of structure formation, and on the retention of black holes in stellar clusters. Here we report the first accurate numerical calculation of this kick, for two nonspinning black holes in a 1.5:1 mass ratio, which is expected on the basis of analytic considerations to give a significant fraction of the maximum possible recoil. We have performed multiple runs with different initial separations, orbital angular momenta, resolutions, extraction radii, and gauges. The full range of our kick speeds is 86-116 km s(-1), and the most reliable runs give kicks between 86 and 97 km s(-1). This is intermediate between the estimates from two recent post-Newtonian analyses and suggests that at redshifts z greater than or similar to 10, halos with masses <= 10(9) M-circle dot will have difficulty retaining coalesced black holes after major mergers. C1 NASA, Goddard Space Flight Ctr, Lab Gravitat Astrophys, Greenbelt, MD 20771 USA. RP Baker, JG (reprint author), NASA, Goddard Space Flight Ctr, Lab Gravitat Astrophys, Code 661, Greenbelt, MD 20771 USA. RI van meter, james/E-7893-2011 NR 51 TC 162 Z9 162 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2006 VL 653 IS 2 BP L93 EP L96 DI 10.1086/510448 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118PZ UT WOS:000242955500005 ER PT J AU Liang, EW Zhang, BB Stamatikos, M Zhang, B Norris, J Gehrels, N Zhang, J Dai, ZG AF Liang, En-Wei Zhang, Bin-Bin Stamatikos, Mike Zhang, Bing Norris, Jay Gehrels, Neil Zhang, Jin Dai, Z. G. TI Temporal profiles and spectral lags of XRF 060218 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; methods : statistical ID GAMMA-RAY BURSTS; 25 APRIL 1998; UNUSUAL SUPERNOVA; PEAK LUMINOSITY; FLASHES; LONG; GRB-060218; PULSES; ENERGY; ENERGETICS AB The spectral and temporal properties of the nonthermal emission of the nearby XRF 060218 in the 0.3-150 keV band are studied. We show that both the spectral energy distribution and the light-curve properties suggest the same origin of the nonthermal emission detected by Swift BAT and XRT. This event has the longest pulse duration and spectral lag observed to date among the known GRBs. The pulse structure and its energy dependence are analogous to typical GRBs. By extrapolating the observed spectral lag to the Compton Gamma Ray Observatory (CGRO) BATSE bands we find that the hypothesis that this event complies with the same luminosity-lag relation with bright GRBs cannot be ruled out at 2 sigma significance level. These intriguing facts, along with its compliance with the Amati relation, indicate that XRF 060218 shares the similar radiation physics as typical GRBs. C1 Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. Guangxi Univ, Dept Phys, Nanning 530004, Peoples R China. Chinese Acad Sci, Yunnan Observ, Natl Astron Observ, Kunming 650011, Peoples R China. Chinese Acad Sci, Grad Sch, Beijing 100039, Peoples R China. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Nanjing Univ, Dept Astron, Nanjing 210093, Peoples R China. RP Zhang, BB (reprint author), Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. EM lew@physics.unlv.edu RI Gehrels, Neil/D-2971-2012; Zhang, Binbin/C-9035-2013 OI Zhang, Binbin/0000-0003-2002-116X NR 55 TC 50 Z9 51 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2006 VL 653 IS 2 BP L81 EP L84 DI 10.1086/510516 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118PZ UT WOS:000242955500002 ER PT J AU Kanevsky, A Carpenter, MH Hesthaven, JS AF Kanevsky, Alex Carpenter, Mark H. Hesthaven, Jan S. TI Idempotent filtering in spectral and spectral element methods SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE idempotent; modal filters; spectral methods; implicit-explicit (IMEX) Runge-Kutta ID GIBBS PHENOMENON; FOURIER METHOD; EQUATIONS; RESOLUTION AB The comparison of numerical results for implicit-explicit and fully explicit Runge-Kutta time integration methods for a nozzle flow problem shows that filtering can significantly degrade the accuracy of the numerical solution for long-time integration problems. We demonstrate analytically and numerically that filtering-in-time errors become additive for parallel to u(N)(x, t + k Delta t) - u(N)(x, t)parallel to << parallel to u(N)(x, t)parallel to when nonidempotent filters are used, and suggest the development and implementation of idempotent filters. (c) 2006 Elsevier Inc. All rights reserved. C1 Brown Univ, Div Appl Math, Providence, RI 02912 USA. NASA, Langley Res Ctr, Aeronaut & Aeroacoust Methods Branch, Hampton, VA 23681 USA. RP Kanevsky, A (reprint author), Brown Univ, Div Appl Math, Box F, Providence, RI 02912 USA. EM kanevsky@dam.brown.edu; Mark.H.Carpenter@nasa.gov; Jan.Hesthaven@Brown.edu RI Hesthaven, Jan/A-7602-2009 OI Hesthaven, Jan/0000-0001-8074-1586 NR 23 TC 10 Z9 10 U1 0 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD DEC 20 PY 2006 VL 220 IS 1 BP 41 EP 58 DI 10.1016/j.jcp.2006.05.014 PG 18 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 120IZ UT WOS:000243079600004 ER PT J AU Zeng, W Horwitz, JL Elliott, HA Moore, TE AF Zeng, W. Horwitz, J. L. Elliott, H. A. Moore, T. E. TI Simulation of the POLAR-observed geomagnetic ion energy spectrometer SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOFT-ELECTRON-PRECIPITATION; AURORAL REGION; F-REGION; ENERGIZATION MECHANISMS; CYCLOTRON RESONANCE; DAYSIDE CUSP/CLEFT; IONOSPHERIC PLASMA; MASS-SPECTROMETER; MAGNETIC ACTIVITY; R-E AB Observations by polar-orbiting spacecraft of outward streaming ionospheric O(+) ions in the polar cap magnetosphere often show decreasing field-aligned streaming energy with antisunward distance from their apparent dayside source, the Cleft Ion Fountain (CIF). In this paper we use the UT Arlington Dynamic Fluid- Kinetic (DyFK) ionospheric plasma transport model to simulate the transport of CIF generated ions along convecting magnetic flux tubes. We compare these simulations to observations by the Thermal Ion Dynamics Experiments ( TIDE) on board the Polar spacecraft, for periods when the Polar orbit was aligned parallel to the noon-midnight direction. When the Polar spacecraft traversed from high altitudes on the dayside to lower altitudes on the nightside, the peak O(+) streaming energy decreased from above 100 eV to below 5 eV. For the case in which the Polar satellite traveled from the nightside higher altitude to the dayside lower altitude, the O(+) energy remained relatively stable, ranging between 20 eV and about 50 eV. Using the DyFK model, we simulate the ionospheric plasma transport and, in particular, the energy spectrometer effects under the geophysical circumstances of the observations, and compare the simulated and observed streaming energies. The results show that the simulated O(+)- streaming energy variations in the noon-midnight direction were in reasonable agreement with those of the Polar/TIDE observations, independent of whether Polar was moving sunward or antisunward, for realistic choices of geophysical parameters. The altitude and the distance to the CIF are the two primary O(+) parameters influencing the O(+) energy spectrometer variations, with the antisunward distance from the CIF being the principal controlling parameter. C1 Univ Texas, Dept Phys, Arlington, TX 76019 USA. SW Res Inst, San Antonio, TX 78238 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Zeng, W (reprint author), Univ Texas, Dept Phys, Arlington, TX 76019 USA. EM zengw@uta.edu RI Moore, Thomas/D-4675-2012 OI Moore, Thomas/0000-0002-3150-1137 NR 51 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 20 PY 2006 VL 111 IS A12 AR A12215 DI 10.1029/2006JA011927 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 120TS UT WOS:000243109600008 ER PT J AU Eldridge, JI Bencic, TJ AF Eldridge, Jeffrey I. Bencic, Timothy J. TI Monitoring delamination of plasma-sprayed thermal barrier coatings by reflectance-enhanced luminescence SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 33rd International Conference on Metallurgical Coatings and Thin Films CY MAY 01-05, 2006 CL San Diego, CA SP Amer Vacuum Soc, Adv Surface Engn Div DE thermal barrier coatings; luminescence; nondestructive evaluation; plasma-spray AB Plasma-sprayed thermal barrier coatings (TBCs) present a challenge for optical diagnostic methods to monitor TBC delamination, because the strong scattering exhibited by plasma-sprayed TBCs severely attenuates light transmitted through the TBC. This paper presents a new approach that indicates delamination in plasma-sprayed TBCs by utilizing a luminescent sublayer that produces significantly greater luminescence intensity from delaminated regions of the TBC. Freestanding coatings were produced with either a Eu-doped or Er-doped yttria-stabilized zirconia (YSZ) luminescent layer below a plasma-sprayed undoped YSZ layer. A NiCr backing layer was added to represent an attached substrate in some sections. For specimens with a Eu-doped YSZ luminescent sublayer, luminescence intensity maps showed excellent contrast between unbacked and NiCr-backed sections. Discernable contrast between unbacked and NiCr-backed sections was not observed for specimens with a Er-doped YSZ luminescent sublayer, because luminescence from Er impurities in the undoped YSZ layer overwhelmed luminescence originating from the Er-doped YSZ sublayer. (c) 2006 Elsevier B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Eldridge, JI (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM jeffrey.i.eldridge@nasa.gov NR 11 TC 23 Z9 25 U1 2 U2 12 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 20 PY 2006 VL 201 IS 7 BP 3926 EP 3930 DI 10.1016/j.surfcoat.2006.08.008 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 121HW UT WOS:000243149700021 ER PT J AU Gentleman, MM Eldridge, JI Zhu, DM Murphy, KS Clarke, DR AF Gentleman, M. M. Eldridge, J. I. Zhu, D. M. Murphy, K. S. Clarke, D. R. TI Non-contact sensing of TBC/BC interface temperature in a thermal gradient SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 33rd International Conference on Metallurgical Coatings and Thin Films CY MAY 01-05, 2006 CL San Diego, CA SP Amer Vacuum Soc, Adv Surface Engn Div DE thermal barrier coatings; luminescence; sensors; thermal gradient ID BARRIER COATINGS AB Luminescence lifetimes of rare-earth ions in yttria-stabilized zirconia, have been shown to exhibit temperature sensitivity from 500-1150 degrees C [Gentleman, M.M. and Clarke, D.R. (2005) Surface and Coatings Technology 200, 1264; Gentleman, M.M. and Clarke, D.R. (2004) Surface and Coatings Technology 188-189, 93.]. These doped zirconias can be deposited along with standard thermal barrier coatings to create thin temperature sensing layers within the coating. Of particular interest is the temperature at the coating/bond coat interface as the oxidation life of a TBC system is exponentially dependent on this temperature. In this study, thin (similar to 10 mu m) layers of europia-doped yttria-stabilized zirconia were deposited by EB-PVD onto bond-coated CMSX-4 superalloy buttons to achieve sensor layers located next to the TBC/BC interface. These coatings were then used to measure the interface temperature in a thermal gradient. Combined with pyrometric measurements of the coating-surface temperature and metal-surface temperature, the thermal conductivity of the coating (1.5 W/mK) and heat flux (similar to 1 MW/m(2)) in the tests were calculated. (c) 2006 Elsevier B.V. All rights reserved. C1 Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Howmet Res Ctr, Whitehall, MI 49461 USA. RP Gentleman, MM (reprint author), Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. EM gentmol@engineering.ucsb.edu RI Clarke, David/D-2616-2009; Albe, Karsten/F-1139-2011 NR 11 TC 25 Z9 25 U1 1 U2 29 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 20 PY 2006 VL 201 IS 7 BP 3937 EP 3941 DI 10.1016/j.surfcoat.2006.08.102 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 121HW UT WOS:000243149700023 ER PT J AU Matlik, JF Farris, TN Haake, FK Swanson, GR Duke, GC AF Matlik, J. F. Farris, T. N. Haake, F. K. Swanson, G. R. Duke, G. C. TI High-frequency, high-temperature fretting-fatigue experiments SO WEAR LA English DT Article DE fretting; fretting fatigue; single crystal nickel; high frequency; contact AB Fretting fatigue is a structural damage mechanism observed when two contacting bodies are subjected to an oscillatory loading. A critical location for fretting fatigue induced damage has been identified at the blade/disk and blade/damper interfaces of gas turbine engine turbomachinery and space propulsion components. The high-temperature, high-frequency loading environment associated with such turbomachinery components can accelerate the fretting fatigue damage at these contact interfaces. The severe stress peaks and stress gradients that develop at the edge-of-contact can drive crack nucleation and propagation. These contact stresses are sensitive to the geometry of the contacting bodies, the contact loads, materials, temperature, and contact surface tribology (friction). To diagnose the threat that small and relatively undetectable fretting cracks pose to damage tolerance and structural integrity of in-service components, the objective of this work is to develop a well-characterized experimental fretting rig capable of investigating fretting behavior of advanced aerospace alloys subjected to load and temperature conditions representative of such turbomachinery components. (c) 2006 Elsevier B.V. All rights reserved. C1 Rolls Royce Corp, Indianapolis, IN 46206 USA. Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. United Technol Corp, Pratt & Whitney Space Propuls, Jupiter, FL 33478 USA. NASA, George C Marshall Space Flight Ctr, Damage Tolerance Assessment Branch, Huntsville, AL 35812 USA. Sverdrup Technol Inc, MSFC Grp, Huntsville, AL 35806 USA. RP Matlik, JF (reprint author), Rolls Royce Corp, Box 420, Indianapolis, IN 46206 USA. EM John.F.Matlik@rolls-royce.com NR 14 TC 13 Z9 13 U1 4 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD DEC 20 PY 2006 VL 261 IS 11-12 BP 1367 EP 1382 DI 10.1016/j.wear.2006.03.048 PG 16 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 116HO UT WOS:000242793300022 ER PT J AU Pfister, GG Emmons, LK Hess, PG Honrath, R Lamarque, JF Martin, MV Owen, RC Avery, MA Browell, EV Holloway, JS Nedelec, P Purvis, R Ryerson, TB Sachse, GW Schlager, H AF Pfister, G. G. Emmons, L. K. Hess, P. G. Honrath, R. Lamarque, J. -F. Martin, M. Val Owen, R. C. Avery, M. A. Browell, E. V. Holloway, J. S. Nedelec, P. Purvis, R. Ryerson, T. B. Sachse, G. W. Schlager, H. TI Ozone production from the 2004 North American boreal fires SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INFRARED-SPECTROSCOPY AFTIR; TROPICAL SOUTH-ATLANTIC; BIOMASS BURNING PLUMES; CARBON-MONOXIDE; TROPOSPHERIC OZONE; FAST-RESPONSE; ATMOSPHERIC CHEMISTRY; MEASUREMENTS ABOARD; EMISSIONS; TRANSPORT AB [1] We examine the ozone production from boreal forest fires based on a case study of wildfires in Alaska and Canada in summer 2004. The model simulations were performed with the chemistry transport model, MOZART-4, and were evaluated by comparison with a comprehensive set of aircraft measurements. In the analysis we use measurements and model simulations of carbon monoxide (CO) and ozone (O-3) at the PICO-NARE station located in the Azores within the pathway of North American outflow. The modeled mixing ratios were used to test the robustness of the enhancement ratio Delta O-3/Delta CO (defined as the excess O-3 mixing ratio normalized by the increase in (CO) and the feasibility for using this ratio in estimating the O3 production from the wildfires. Modeled and observed enhancement ratios are about 0.25 ppbv/ppbv which is in the range of values found in the literature and results in a global net O-3 production of 12.9 +/- 2 Tg O-3 during summer 2004. This matches the net O-3 production calculated in the model for a region extending from Alaska to the east Atlantic (9-11 Tg O-3) indicating that observations at PICO-NARE representing photochemically well aged plumes provide a good measure of the O-3 production of North American boreal fires. However, net chemical loss of fire-related O-3 dominates in regions far downwind from the fires (e.g., Europe and Asia) resulting in a global net O-3 production of 6 Tg O3 during the same time period. On average, the fires increased the O-3 burden ( surface -300 mbar) over Alaska and Canada during summer 2004 by about 7-9% and over Europe by about 2-3%. C1 Natl Ctr Atmospher Res, Boulder, CO 80302 USA. Michigan Technol Univ, Dept Civil & Environm Engn, Houghton, MI 49931 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Natl Ocean & Atmospher Adm, Aeron Lab, Boulder, CO 80305 USA. CNRS, Lab Aerol, F-31400 Toulouse, France. Cranfield Univ, Facil Airborne Atmospher Measurement, Cranfield MK443 0AL, Beds, England. German Aerosp Ctr, Inst Atmospher Phys, D-82234 Oberpfaffenhofen, Germany. RP Pfister, GG (reprint author), Natl Ctr Atmospher Res, 3350 Mitchell Lane, Boulder, CO 80302 USA. EM pfister@ucar.edu; emmons@ucar.edu; hess@ucar.edu; reh@mtu.edu; lamar@ucar.edu; mvalmart@mtu.edu; rcowen@mtu.edu; m.a.avery@larc.nasa.gov; edward.v.browell@.nasa.gov; nedp@aero.obs-mip.fr; rupu@faam.ac.uk; thomas.b.ryerson@noaa.gov; g.w.sachse@larc.nasa.gov; hans.schlager@dlr.de RI Hess, Peter/M-3145-2015; Emmons, Louisa/R-8922-2016; Manager, CSD Publications/B-2789-2015; Pfister, Gabriele/A-9349-2008; Val Martin, Maria/D-6955-2011; Holloway, John/F-9911-2012; Ryerson, Tom/C-9611-2009; Lamarque, Jean-Francois/L-2313-2014 OI Hess, Peter/0000-0003-2439-3796; Emmons, Louisa/0000-0003-2325-6212; Holloway, John/0000-0002-4585-9594; Lamarque, Jean-Francois/0000-0002-4225-5074 NR 44 TC 68 Z9 69 U1 1 U2 21 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 16 PY 2006 VL 111 IS D24 AR D24S07 DI 10.1029/2006JD007695 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 118LG UT WOS:000242943200008 ER PT J AU Singh, HB Brune, WH Crawford, JH Jacob, DJ Russell, PB AF Singh, H. B. Brune, W. H. Crawford, J. H. Jacob, D. J. Russell, P. B. TI Overview of the summer 2004 intercontinental chemical transport experiment - North America (INTEX-A) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PACIFIC EXPLORATORY MISSION; INCREASING BACKGROUND OZONE; UNITED-STATES; AIR-POLLUTION; SURFACE OZONE; TROPOSPHERIC OZONE; TROPICAL PACIFIC; MACE-HEAD; EUROPE; PLUME AB [1] The INTEX-A field mission was conducted in the summer of 2004 ( 1 July to 15 August 2004) over North America (NA) and the Atlantic in cooperation with multiple national and international partners as part of a consortium called ICARTT. The main goals of INTEX-A were to (1) characterize the composition of the troposphere over NA, (2) characterize the outflow of pollution from NA and determine its chemical evolution during transatlantic transport, (3) validate satellite observations of tropospheric composition, (4) quantitatively relate atmospheric concentrations of gases and aerosols with their sources and sinks, and (5) investigate aerosol properties and their radiative effects. INTEX-A primarily relied on instrumented DC-8 and J-31 aircraft platforms to achieve its objectives. The DC-8 was equipped to measure detailed gas and aerosol composition and provided sufficient range and altitude capability to coordinate activities with distant partners and to sample the entire midlatitude troposphere. The J-31 was specifically focused on radiative effects of clouds and aerosols and operated largely in the Gulf of Maine. Satellite products along with meteorological and 3-D chemical transport model forecasts were integrated into the flight planning process. Intercomparisons were performed to quantify the accuracy of data and to create a unified data set. Satellite validation activities principally focused on Terra (MOPITT, MODIS, and MISR), Aqua (AIRS and MODIS) and Envisat (SCIAMACHY) to validate observations of CO, NO2, HCHO, H2O, and aerosol. Persistent fires in Alaska and NW Canada offered opportunities to quantify emissions from fires and study the transport and evolution of biomass burning plumes. Contrary to expectations, several pollution plumes of Asian origin, frequently mixed with stratospheric air, were sampled over NA. Quasi-Lagrangian sampling was successfully carried out to study chemical aging of plumes during transport over the Atlantic. Lightning NOx source was found to be far larger than anticipated and provided a major source of error in model simulations. The composition of the upper troposphere was significantly perturbed by influences from surface pollution and lightning. Drawdown of CO2 was characterized over NA and its atmospheric abundance related to terrestrial sources and sinks. INTEX-A observations provide a comprehensive data set to test models and evaluate major pathways of pollution transport over NA and the Atlantic. This overview provides a context within which the present and future INTEX-A/ICARTT publications can be understood. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16902 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Harvard Univ, Div Appl Sci, Cambridge, MA 02138 USA. RP Singh, HB (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM hanwant.b.singh@nasa.gov RI Crawford, James/L-6632-2013 OI Crawford, James/0000-0002-6982-0934 NR 59 TC 141 Z9 141 U1 4 U2 21 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 16 PY 2006 VL 111 IS D24 AR D24S01 DI 10.1029/2006JD007905 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 118LG UT WOS:000242943200009 ER PT J AU Smith, MD Wolff, MJ Spanovich, N Ghosh, A Banfield, D Christensen, PR Landis, GA Squyres, SW AF Smith, Michael D. Wolff, Michael J. Spanovich, Nicole Ghosh, Amitabha Banfield, Don Christensen, Philip R. Landis, Geoffrey A. Squyres, Steven W. TI One Martian year of atmospheric observations using MER Mini-TES SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID THERMAL EMISSION SPECTROMETER; MARS GLOBAL SURVEYOR; RADIO OCCULTATION MEASUREMENTS; IMAGING-SYSTEM THEMIS; ART. NO. 5115; MERIDIANI-PLANUM; GUSEV CRATER; INTERANNUAL VARIABILITY; EXPLORATION ROVERS; OPPORTUNITY ROVER AB The Spirit and Opportunity Mars Exploration Rovers (MER) landed on the surface of Mars in January 2004. Thermal infrared spectra taken by the Miniature Thermal Emission Spectrometer (Mini-TES) instrument on board each rover, collected in both the upward-looking and downward-looking geometries, has allowed for the retrieval of atmospheric temperatures between 1 and 2000 m above the surface, the column optical depth of dust, and the column abundance of water vapor for more than one full Martian year. During this period, Mini-TES has observed the annual cycle of temperature variations, the diurnal growth and decay of a near-surface highly superadiabatic layer, and random temperature fluctuations on a timescale of less than a minute. Mini-TES observations also record the timing, duration, and intensity of several local-scale and regional-scale dust storms and the annual variation of water vapor abundance at the two rover locations. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Space Sci Inst, Boulder, CO USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Tharsis Inc, Gaithersburg, MD USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Smith, MD (reprint author), NASA, Goddard Space Flight Ctr, Code 693, Greenbelt, MD 20771 USA. EM michael.d.smith@nasa.gov RI Smith, Michael/C-8875-2012; OI Banfield, Don/0000-0003-2664-0164 NR 53 TC 65 Z9 65 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 16 PY 2006 VL 111 IS E12 AR E12S13 DI 10.1029/2006JE002770 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 118MB UT WOS:000242945300002 ER PT J AU Nyquist, L Bogard, D Yamaguchi, A Shih, CY Karouji, Y Ebihara, M Reese, Y Garrison, D McKay, G Takeda, H AF Nyquist, L. Bogard, D. Yamaguchi, A. Shih, C. -Y. Karouji, Y. Ebihara, M. Reese, Y. Garrison, D. McKay, G. Takeda, H. TI Feldspathic clasts in Yamato-86032: Remnants of the lunar crust with implications for its formation and impact history SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID NORITIC ANORTHOSITE CLAST; NEUTRON-CAPTURE; METEORITES; EVOLUTION; SM; PETROLOGY; SURFACE; MOON; AGE; BRECCIA-15445 AB Low concentrations of Th and Fe in the Yamato (Y)-86032 bulk meteorite support earlier suggestions that Y-86032 comes from a region of the moon far distant from the Procellarum KREEP Terrain (PKT), probably from the lunar farside. Ar-39-Ar-40, Rb-Sr, Sm-Nd, and Sm-isotopic studies characterize the chronology of Y-86032 and its precursors in the mega regolith. One of the rock types present in a light gray breccia lithology is an anorthosite characterized by plagioclase with An similar to 93, i.e., more sodic than lunar FANs, but with very low Rb-87/Sr-86 and Sr-87/Sr-86 similar to those of FANs. (FAN stands for Ferroan Anorthosite). This "An93 anorthosite" has Nd-isotopic systematics similar to those of nearside norites. A FAN-like "An97 anorthosite" is present in a second light-colored feldspathic breccia clast and has a more negative epsilon(Nd) value consistent with residence in a LREE-enriched environment as would be provided by an early plagioclase flotation crust on the Lunar Magma Ocean (LMO). This result contrasts with generally positive values of epsilon(Nd) for Apollo 16 FANs suggesting the possibility of assymetric development of the LMO. Other possible explanations for the dichotomy in epsilon(Nd) values are advanced in the text. The Y-86032 protolith formed at least 4.43 +/- 0.03 Ga ago as determined from a Sm-Nd isochron for mineral fragments from the breccia, clast composed predominantly of An93 anorthosite and a second clast of more varied composition. We interpret the mineral fragments as being predominatly from a cogenetic rock suite. An Ar-39-Ar-40 age of 4.36-4.41 +/- 0.035 Ga for a third clast composed predominantly of An97 anorthosite supports an old age for the protolith. Initial Nd-143/Nd-144 in that clast was -0.64 +/- +/- 0.13 epsilon-units below Nd-143/Nd-144 in reservoirs having chondritic Sm/Nd ratios, consistent with prior fractionation of mafic cumulates from the LMO. A maximum in the Ar-39-Ar-40 age spectrum of 4.23 +/- 0.03 Ga for a second sample of the same feldspathic breccia clast probably reflects some diffusive Ar-40 loss. Lack of solar wind and lunar atmosphere implanted Ar in the light gray breccia clast allows determination of an Ar-39/Ar-40 age of 4.10 +/- 0.02 Ga, which is interpreted as the time of initial brecciation of this litholgy. After correction for implanted lunar atmosphere 40Ar, impact melt and dark regolith clasts give Ar ages of 3.8 +/- 0.1 Ga implying melt formation and final breccia assembly similar to 3.8 Ga ago. Some breccia lithologies were exposed to thermal neutron fluences of similar to 2 x 10(15) n/cm(2), only about 1% of the fluence experienced by some other lunar highlands meteorites. Other lithologies experienced neutron fluences of similar to 1 X 10(15) n/cm(2). Thus, Y-86032 spent most of the time following final brecciation deeply buried in the megaregolith. The neutron fluence data are consistent with cosmogenic Ar-38(cos) cosmic ray exposure ages of similar to 10 Ma. Variations among differing lithologies in the amount of several regolith exposure indicators, including cosmogenic noble gas abundances, neutron capture induced variations in Sm isotopic abundances, and Ir contents, are consistent with a period of early (greater than or similar to 3. 8 Ga ago) lunar regolith exposure, subsequent deep burial at greater than or similar to 5 m depth, an ejection from the moon similar to 7-10 Ma ago. (c) 2006 Elsevier Inc. All rights reserved. C1 NASA, Lyndon B Johnson Space Ctr, ARES, Houston, TX 77058 USA. Natl Inst Polar Res, Tokyo 1738515, Japan. Grad Univ Adv Studies, Sch Multidisciplinary Sci, Dept Polar Sci, Tokyo 1738515, Japan. ESCG Sverdrup, Houston, TX 77058 USA. Tokyo Metropolitan Univ, Dept Chem, Tokyo 1920397, Japan. ESCG Muniz Engn, Houston, TX 77058 USA. Chiba Inst Technol, Res Inst, Narashino, Chiba 2570016, Japan. RP Nyquist, L (reprint author), NASA, Lyndon B Johnson Space Ctr, ARES, Mail Code KR, Houston, TX 77058 USA. EM laurence.e.nyquist@nasa.gov NR 76 TC 49 Z9 49 U1 1 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC 15 PY 2006 VL 70 IS 24 BP 5990 EP 6015 DI 10.1016/j.gca.2006.07.042 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 121OF UT WOS:000243166200006 ER PT J AU Stopar, JD Taylor, GJ Hamilton, VE Browning, L AF Stopar, Julie D. Taylor, G. Jeffrey Hamilton, Victoria E. Browning, Lauren TI Kinetic model of olivine dissolution and extent of aqueous alteration on Mars SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID THERMAL EMISSION SPECTROMETER; MINI-TES EXPERIMENT; MERIDIANI-PLANUM; GUSEV CRATER; SPIRIT ROVER; FORSTERITE DISSOLUTION; NEAR-SURFACE; MOSSBAUER SPECTROMETER; MARTIAN METEORITES; MICROSCOPIC IMAGER AB If water was ever present on Mars, as suggested by geomorphological features, then much of the surface and subsurface may have experienced chemical weathering. Among those materials most readily altered is olivine, which has been identified on the Martian surface with IR spectroscopy and Mossbauer techniques and occurs in Martian meteorites. We use geochemical models of olivine dissolution kinetics to constrain the residence time of olivine on the surface of Mars in the presence of liquid water. From these models, we have calculated maximum dissolution rates and minimum residence times for olivine as a function of temperature, pH, Fe-composition, and particle size. In general, the most favorable conditions for olivine dissolution are fayalite-rich compositions, small particle sizes, high temperatures, and acidic solutions that are far from equilibrium. The least favorable conditions for olivine dissolution are forsterite-rich compositions, large particle sizes, ultra-low temperatures, and a neutral pH solution near equilibrium. By using kinetic models of olivine dissolution to bound dissolution rates and residence times, we can make inferences about the temporal extent of aqueous alteration on the surface of Mars. Under favorable conditions (pH 2, 5 degrees C, and far from equilibrium) a relatively large 0.1 cm (radius) particle of Fo(65) composition can completely dissolve in 370 years. Particles may last 10(2)-10(4) times longer under less favorable conditions. However, residence times of a few million years or less are small compared to the age of most of the Martian surface. The survival of olivine on the surface of Mars, especially in older terrains, implies that contact with aqueous solutions has been limited and wet periods on Mars have been short-lived. (c) 2006 Elsevier Inc. All rights reserved. C1 Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Univ Hawaii, NASA, Astrobiol Inst, Honolulu, HI 96822 USA. Browning Res, San Antonio, TX 78255 USA. RP Stopar, JD (reprint author), Univ Hawaii, Hawaii Inst Geophys & Planetol, 1680 East West Rd, Honolulu, HI 96822 USA. EM jstopar@higp.hawaii.edu OI Stopar, Julie/0000-0003-1578-3688 NR 83 TC 38 Z9 38 U1 3 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC 15 PY 2006 VL 70 IS 24 BP 6136 EP 6152 DI 10.1016/j.gca.2006.07.039 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 121OF UT WOS:000243166200014 ER PT J AU Applegarth, MT Stefanov, WL AF Applegarth, Michael T. Stefanov, William L. TI Use of Thermal Infrared Multispectral Scanner (TIMS) imagery to investigate upslope particle size controls on and piedmont morphology SO GEOMORPHOLOGY LA English DT Article DE Thermal Infrared Multispectral Scanner (TIMS); pediment; piedmont; Arizona ID EMISSION-SPECTROSCOPY; SPECTRAL CONTRAST; DEATH-VALLEY; ALLUVIAL FANS; MINERALS; CALIFORNIA; ROCKS; SURFACES; BEHAVIOR; FIELD AB Geomorphic differences between slopes backing two distinct desert piedmont types provide a proxy indicator for the kind of landform developed at the corresponding mountain base. Here, the term 'bedrock pediment' describes subaerial bedrock platforms that emanate from a mountain base while 'alluvial slope' describes suballuvial bedrock platforms that extend from the mountain. Mountain slopes backing bedrock pediments have been demonstrated to be mantled by larger clast sizes than corresponding slopes backing alluvial slopes in the Phoenix region, Arizona, USA. The present research focuses on using the disparate particle sizes between slopes backing bedrock pediments and alluvial slopes as an indicator for the piedmont form developed at the mountain base, and uses high-resolution remotely sensed digital data as a medium for quantitative landform assessments. A gravel+bedrock versus soil index developed from airborne midinfrared multispectral imagery acquired by the Thermal Infrared Multispectral Scanner (TIMS) indicates the presence of slopes mantled with larger particle sizes versus slopes mantled with smaller particle sizes and greater soil coverage. Two test areas confirm the applicability of this method and further demonstrate the usefulness of high-resolution midinfrared multispectral imagery as a geomorphic tool in and regions. (c) 2006 Elsevier B.V. All rights reserved. C1 Shippensburg Univ, Dept Geog & Earth Sci, Shippensburg, PA 17257 USA. NASA, Lyndon B Johnson Space Ctr, Image Sci & Anal Lab, Houston, TX 77058 USA. RP Applegarth, MT (reprint author), Shippensburg Univ, Dept Geog & Earth Sci, Shippensburg, PA 17257 USA. EM mtappl@ship.edu NR 45 TC 3 Z9 3 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD DEC 15 PY 2006 VL 82 IS 3-4 BP 388 EP 397 DI 10.1016/j.geomorph.2006.06.002 PG 10 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 121NB UT WOS:000243163200014 ER PT J AU Sherwood, SC Kursinski, ER Read, WG AF Sherwood, Steven C. Kursinski, E. Robert Read, William G. TI A distribution law for free-tropospheric relative humidity SO JOURNAL OF CLIMATE LA English DT Article ID RADIO OCCULTATION DATA; LARGE-SCALE ADVECTION; TROPICAL WATER-VAPOR; LOWER STRATOSPHERE; SUBTROPICAL HUMIDITY; AURA SATELLITE; EOS MLS; VALIDATION; SIMULATIONS; TROPOPAUSE AB The probability distribution of local relative humidity R in the free troposphere is explored by comparing a simple theoretical calculation with observations from the global positioning system (GPS) and the Microwave Limb Sounder (MLS). The calculation is based on a parcel of air that conserves its composition during diabatic subsidence, until it is resaturated by randomly entering a convective system. This simple "advection-condensation" model of relative humidity predicts a probability density for R proportional to Rr-1, where r is the ratio of time scales associated with subsidence drying and random moistening. The observations obey this distribution remarkably well from 600 to 200 hPa in the Tropics and midlatitudes; possible reasons for this are discussed. The lowest values of R are predicted, and observed, to be the most probable. The observed vertical variation of R is well explained by that of the subsidence time scale, which is set by large-scale dynamics and radiation. These results imply that cloud microphysics exerts little control on water vapor's greenhouse effect, but that relatively subtle dynamical changes have the potential to alter the strength of its feedback on climate change. C1 Yale Univ, New Haven, CT 06520 USA. Univ Arizona, Tucson, AZ USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Sherwood, SC (reprint author), Yale Univ, New Haven, CT 06520 USA. EM ssherwood@alum.mit.edu RI Sherwood, Steven/B-5673-2008 OI Sherwood, Steven/0000-0001-7420-8216 NR 41 TC 28 Z9 28 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PD DEC 15 PY 2006 VL 19 IS 24 BP 6267 EP 6277 DI 10.1175/JCLI3978.1 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 119IH UT WOS:000243005500001 ER PT J AU Curtis, S Adler, RF Huffman, GJ Gu, GJ Bolvin, DT Nelkin, EJ AF Curtis, Scott Adler, Robert F. Huffman, George J. Gu, Guojun Bolvin, David T. Nelkin, Eric J. TI Comments on "El Nino: Catastrophe or opportunity" SO JOURNAL OF CLIMATE LA English DT Editorial Material ID PRECIPITATION C1 E Carolina Univ, Dept Geog, Atmospher Sci Lab, Greenville, NC 27858 USA. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. RP Curtis, S (reprint author), E Carolina Univ, Dept Geog, Atmospher Sci Lab, Brewster A 232, Greenville, NC 27858 USA. EM curtisw@ecu.edu RI Curtis, Scott/C-1115-2013; Huffman, George/F-4494-2014; OI Huffman, George/0000-0003-3858-8308; Curtis, Scott/0000-0001-9065-8639 NR 8 TC 3 Z9 3 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC 15 PY 2006 VL 19 IS 24 BP 6439 EP 6442 DI 10.1175/JCLI4009.1 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 119IH UT WOS:000243005500013 ER PT J AU Squyres, SW Arvidson, RE Bollen, D Bell, JF Bruckner, J Cabrol, NA Calvin, WM Carr, MH Christensen, PR Clark, BC Crumpler, L Des Marais, DJ d'Uston, C Economou, T Farmer, J Farrand, WH Folkner, W Gellert, R Glotch, TD Golombek, M Gorevan, S Grant, JA Greeley, R Grotzinger, J Herkenhoff, KE Hviid, S Johnson, JR Klingelhofer, G Knoll, AH Landis, G Lemmon, M Li, R Madsen, MB Malin, MC McLennan, SM McSween, HY Ming, DW Moersch, J Morris, RV Parker, T Rice, JW Richter, L Rieder, R Schroder, C Sims, M Smith, M Smith, P Soderblom, LA Sullivan, R Tosca, NJ Wanke, H Wdowiak, T Wolff, M Yen, A AF Squyres, S. W. Arvidson, R. E. Bollen, D. Bell, J. F., III Brueckner, J. Cabrol, N. A. Calvin, W. M. Carr, M. H. Christensen, P. R. Clark, B. C. Crumpler, L. Des Marais, D. J. d'Uston, C. Economou, T. Farmer, J. Farrand, W. H. Folkner, W. Gellert, R. Glotch, T. D. Golombek, M. Gorevan, S. Grant, J. A. Greeley, R. Grotzinger, J. Herkenhoff, K. E. Hviid, S. Johnson, J. R. Klingelhoefer, G. Knoll, A. H. Landis, G. Lemmon, M. Li, R. Madsen, M. B. Malin, M. C. McLennan, S. M. McSween, H. Y. Ming, D. W. Moersch, J. Morris, R. V. Parker, T. Rice, J. W., Jr. Richter, L. Rieder, R. Schroeder, C. Sims, M. Smith, M. Smith, P. Soderblom, L. A. Sullivan, R. Tosca, N. J. Waenke, H. Wdowiak, T. Wolff, M. Yen, A. TI Overview of the Opportunity Mars Exploration Rover mission to Meridiani Planum: Eagle crater to Purgatory ripple SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID HEMATITE MINERALIZATION; LANDING SITE; MINERALOGY; SPECTROMETER; ROCKS; WATER; CHEMISTRY; JAROSITE; STREAKS; SOILS AB The Mars Exploration Rover Opportunity touched down at Meridiani Planum in January 2004 and since then has been conducting observations with the Athena science payload. The rover has traversed more than 5 km, carrying out the first outcrop-scale investigation of sedimentary rocks on Mars. The rocks of Meridiani Planum are sandstones formed by eolian and aqueous reworking of sand grains that are composed of mixed fine-grained siliciclastics and sulfates. The siliciclastic fraction was produced by chemical alteration of a precursor basalt. The sulfates are dominantly Mg-sulfates and also include Ca-sulfates and jarosite. The stratigraphic section observed to date is dominated by eolian bedforms, with subaqueous current ripples exposed near the top of the section. After deposition, interaction with groundwater produced a range of diagenetic features, notably the hematite-rich concretions known as "blueberries." The bedrock at Meridiani is highly friable and has undergone substantial erosion by wind-transported basaltic sand. This sand, along with concretions and concretion fragments eroded from the rock, makes up a soil cover that thinly and discontinuously buries the bedrock. The soil surface exhibits both ancient and active wind ripples that record past and present wind directions. Loose rocks on the soil surface are rare and include both impact ejecta and meteorites. While Opportunity's results show that liquid water was once present at Meridiani Planum below and occasionally at the surface, the environmental conditions recorded were dominantly arid, acidic, and oxidizing and would have posed some significant challenges to the origin of life. C1 Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Max Planck Inst Chem, D-55020 Mainz, Germany. NASA Ames SETI Inst, Moffett Field, CA 94035 USA. Univ Nevada, Dept Geol Sci, Reno, NV 89557 USA. US Geol Survey, Menlo Pk, CA 94025 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Lockheed Martin Corp, Littleton, CO 80127 USA. New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Space Sci Inst, Boulder, CO 80301 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. Honeybee Robot, New York, NY 10001 USA. Smithsonian Inst, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Max Planck Inst Sonnensyst Forsch, Katlenburg Lindau, Germany. Johannes Gutenberg Univ Mainz, Inst Anorgan & Analyt Chem, D-55099 Mainz, Germany. Harvard Univ, Bot Museum, Cambridge, MA 02138 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA. Niels Bohr Inst, Orsted Lab, DK-2100 Copenhagen, Denmark. Malin Space Sci Syst, San Diego, CA 92191 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. DLR Inst Space Simulat, D-51170 Cologne, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Alabama Birmingham, Dept Phys, Birmingham, AL 35294 USA. Space Sci Inst, Martinez, GA 30907 USA. RP Squyres, SW (reprint author), Cornell Univ, Dept Astron, 428 Space Sci Bldg, Ithaca, NY 14853 USA. EM squyres@astrosun.tn.cornell.edu RI Glotch, Timothy/B-6829-2008; Lemmon, Mark/E-9983-2010; Schroder, Christian/B-3870-2009; Moersch, Jeffrey/F-7189-2010; Smith, Michael/C-8875-2012; Madsen, Morten/D-2082-2011; Johnson, Jeffrey/F-3972-2015 OI Lemmon, Mark/0000-0002-4504-5136; Schroder, Christian/0000-0002-7935-6039; Madsen, Morten/0000-0001-8909-5111; NR 48 TC 79 Z9 82 U1 2 U2 29 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 15 PY 2006 VL 111 IS E12 AR E12S12 DI 10.1029/2006JE002771 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 118LY UT WOS:000242945000001 ER PT J AU Yen, AS Mittlefehldt, DW McLennan, SM Gellert, R Bell, JF McSween, HY Ming, DW McCoy, TJ Morris, RV Golombek, M Economou, T Madsen, MB Wdowiak, T Clark, BC Jolliff, BL Schroder, C Bruckner, J Zipfel, J Squyres, SW AF Yen, A. S. Mittlefehldt, D. W. McLennan, S. M. Gellert, R. Bell, J. F., III McSween, H. Y., Jr. Ming, D. W. McCoy, T. J. Morris, R. V. Golombek, M. Economou, T. Madsen, M. B. Wdowiak, T. Clark, B. C. Jolliff, B. L. Schroeder, C. Brueckner, J. Zipfel, J. Squyres, S. W. TI Nickel on Mars: Constraints on meteoritic material at the surface SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MAGNETIC-PROPERTIES EXPERIMENTS; MERIDIANI-PLANUM; MARTIAN ATMOSPHERE; GUSEV CRATER; INTERPLANETARY DUST; CHEMISTRY; SOILS; ROCKS; MINERALOGY; HEMATITE AB Impact craters and the discovery of meteorites on Mars indicate clearly that there is meteoritic material at the Martian surface. The Alpha Particle X-ray Spectrometers (APXS) on board the Mars Exploration Rovers measure the elemental chemistry of Martian samples, enabling an assessment of the magnitude of the meteoritic contribution. Nickel, an element that is greatly enhanced in meteoritic material relative to samples of the Martian crust, is directly detected by the APXS and is observed to be geochemically mobile at the Martian surface. Correlations between nickel and other measured elements are used to constrain the quantity of meteoritic material present in Martian soil and sedimentary rock samples. Results indicate that analyzed soils samples and certain sedimentary rocks contain an average of 1% to 3% contamination from meteoritic debris. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Univ Alabama Birmingham, Dept Phys, Birmingham, AL 35294 USA. Lockheed Martin Corp, Littleton, CO 80127 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Johannes Gutenberg Univ Mainz, D-6500 Mainz, Germany. Max Planck Inst Chem, D-55020 Mainz, Germany. Forschungsinst & Nat Museum Senckenberg, Frankfurt, Germany. RP Yen, AS (reprint author), CALTECH, Jet Prop Lab, Mail Code 183-501,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM albert.yen@jpl.nasa.gov RI Schroder, Christian/B-3870-2009; Madsen, Morten/D-2082-2011 OI Schroder, Christian/0000-0002-7935-6039; Madsen, Morten/0000-0001-8909-5111 NR 93 TC 31 Z9 31 U1 3 U2 20 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 15 PY 2006 VL 111 IS E12 AR E12S11 DI 10.1029/2006JE002797 PG 25 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 118LY UT WOS:000242945000002 ER PT J AU Zhang, QY Xiao, XM Braswell, B Linder, E Ollinger, S Smith, ML Jenkins, JP Baret, F Richardson, AD Moore, B Minocha, R AF Zhang, Qingyuan Xiao, Xiangming Braswell, Bobby Linder, Ernst Ollinger, Scott Smith, Marie-Louise Jenkins, Julian P. Baret, Fred Richardson, Andrew D. Moore, Berrien, III Minocha, Rakesh TI Characterization of seasonal variation of forest canopy in a temperate deciduous broadleaf forest, using daily MODIS data SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE Bartlett Experimental Forest; MODIS; snow; atmosphere contamination; phenology; PROSPECT; SAIL-2; FAPAR; Markov Chain Monte Carlo; (MCMC) method ID LEAF-AREA INDEX; PHOTOSYNTHETICALLY ACTIVE RADIATION; GROSS PRIMARY PRODUCTION; GLOBAL PRIMARY PRODUCTION; SUGAR-BEET CANOPIES; SAIL MODEL; REFLECTANCE MODELS; BIDIRECTIONAL REFLECTANCE; TERRESTRIAL ECOSYSTEMS; SATELLITE-OBSERVATIONS AB In this paper, we present an improved procedure for collecting no or little atmosphere- and snow-contaminated observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The resultant time series of daily MODIS data of a temperate deciduous broadleaf forest (the Bartlett Experimental Forest) in 2004 show strong seasonal dynamics of surface reflectance of green, near infrared and shortwave infrared bands, and clearly delineate leaf phenology and length of plant growing season. We also estimate the fractions of photosynthetically active radiation (PAR) absorbed by vegetation canopy (FAPAR(canopy)), leaf (FAPAR(leaf)), and chlorophyll (FAPAR(chl)), respectively, using a coupled leaf-canopy radiative transfer model (PROSAIL-2) and daily MODIS data. The Markov Chain Monte Carlo (MCMC) method (the Metropolis algorithm) is used for model inversion, which provides probability distributions of the retrieved variables. A two-step procedure is used to estimate the fractions of absorbed PAR: (1) to retrieve biophysical and biochemical variables from MODIS images using the PROSAIL-2 model; and (2) to calculate the fractions with the estimated model variables from the first step. Inversion and forward simulations of the PROSAIL-2 model are carried out for the temperate deciduous broadleaf forest during day of year (DOY) 184 to 201 in 2005. The reproduced reflectance values from the PROSAIL-2 model agree well with the observed MODIS reflectance for the five spectral bands (green, red, NIR1, NIR2, and SWIR1]). The estimated leaf area index, leaf dry matter, leaf chlorophyll content and FAPAR(canopy) values are close to field measurements at the site. The results also showed significant differences between FAPAR(canopy) and FAPAR(chl) at the site. Our results show that MODIS imagery provides important information on biophysical and biochemical variables at both leaf and canopy levels. (c) 2006 Elsevier Inc. All rights reserved. C1 Univ New Hampshire, Inst Study Earth Oceans & Space, Complex Syst Res Ctr, Durham, NH 03824 USA. Univ New Hampshire, Dept Math & Stat, Durham, NH 03824 USA. US Forest Serv, NE Res Stn, USDA, Durham, NH 03824 USA. Inst Natl Rech Agron, F-84914 Avignon, France. RP Zhang, QY (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. EM qyz72@yahoo.com RI Richardson, Andrew/F-5691-2011; Ollinger, Scott/N-3380-2014; Braswell, Bobby/D-6411-2016; Baret, Fred/C-4135-2011 OI Richardson, Andrew/0000-0002-0148-6714; Ollinger, Scott/0000-0001-6226-1431; Braswell, Bobby/0000-0002-4061-9516; Baret, Fred/0000-0002-7655-8997 NR 74 TC 45 Z9 47 U1 4 U2 27 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD DEC 15 PY 2006 VL 105 IS 3 BP 189 EP 203 DI 10.1016/j.rse.2006.06.013 PG 15 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 111RZ UT WOS:000242473300002 ER PT J AU Vermote, EF Saleous, NZ AF Vermote, E. F. Saleous, N. Z. TI Calibration of NOAA16 AVHRR over a desert site using MODIS data SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE calibration; AVFIRR; MODIS ID HIGH-RESOLUTION RADIOMETER; NEAR-INFRARED CHANNELS; IMAGING SPECTRORADIOMETER; WATER-VAPOR AB This paper presents a new approach to AVHRR-sensors cross-calibration in the visible to shortwave-infrared spectral domain using an a-priori, well calibrated sensor (MODIS). The approach has been tested over a stable Sahara desert site and was initially applied to compare the absolute calibration coefficients of three different bands of the Terra and Aqua MODIS instruments. The observed agreement was better than 1% for bands 1 (0.67 mu m), 2 (0.87 mu m) and 7 (2.13 mu m). The approach was then applied to cross-calibrate the AVHRR sensor onboard NOAA16. The absolute calibration coefficients derived for bands 1 and 2, using the Terra MODIS as a reference, were compared to the vicarious coefficients derived using the ocean and clouds method [Vermote E.F. and Kaufman Y.J. (1995). Absolute calibration of AVHRR visible and near-infrared channels using ocean and cloud views, International Journal of Remote Sensing, 16, 13, 2317-2340.]. The coefficients were consistent within less than 1%. (c) 2006 Elsevier Inc. All rights reserved. C1 Univ Maryland, Dept Geog, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Washington, DC 20546 USA. SAIC, San Diego, CA 92121 USA. RP Vermote, EF (reprint author), Univ Maryland, Dept Geog, College Pk, MD 20742 USA. EM eric@ltdri.org RI Vermote, Eric/K-3733-2012 NR 11 TC 62 Z9 65 U1 1 U2 14 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD DEC 15 PY 2006 VL 105 IS 3 BP 214 EP 220 DI 10.1016/j.rse.2006.06.015 PG 7 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 111RZ UT WOS:000242473300004 ER PT J AU Anderson, J Martin, ME Smith, ML Dubayah, RO Hofton, MA Hyde, P Peterson, BE Blair, JB Knox, RG AF Anderson, Jeanne Martin, M. E. Smith, M-L. Dubayah, R. O. Hofton, M. A. Hyde, P. Peterson, B. E. Blair, J. B. Knox, R. G. TI The use of waveform lidar to measure northern temperate mixed conifer and deciduous forest structure in New Hampshire SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE LVIS; laser altimetry; structure; height; biomass; quadratic mean stem diameter ID LASER ALTIMETER; AIRBORNE LIDAR; BIOPHYSICAL PROPERTIES; FOOTPRINT LIDAR; TROPICAL FOREST; CANOPY; VALIDATION; BIOMASS; STAND; TOPOGRAPHY AB The direct retrieval of canopy height and the estimation of aboveground biomass are two important measures of forest structure that can be quantified by airborne laser scanning at landscape scales. These and other metrics are central to studies attempting to quantify global carbon cycles and to improve understanding of the spatial variation in forest structure evident within differing biomes. Data acquired using NASA's Laser Vegetation Imaging Sensor (LVIS) over the Bartlett Experimental Forest (BEF) in central New Hampshire (USA) was used to assess the performance of waveform lidar in a northern temperate mixed conifer and deciduous forest. Using coincident plots established for this study, we found strong agreement between field and lidar measurements of height (r(2)=0.80, 2 p < 0.000) at the footprint level. Allometric calculations of aboveground biomass (AGBM) and LVIS metrics (AGBM: r(2)=0.61, PRESS RMSE=58.0 Mg ha(-1), p < 0.000) and quadratic mean stem diameter (QMSD) and LVIS metrics (r(2) = 0.54, p = 0.002) also showed good agreement at the footprint level. Application of a generalized equation for determining AGBM proposed by Lefsky et a]. (2002a) to footprint-level field data from Bartlett resulted in a coefficient of determination of 0.55; RMSE = 64.4 Mg ha(-1); p 0.002. This is slightly weaker than the strongest relationship found with the best-fit single term regression model. Relationships between a permanent grid of USDA Forest Service inventory plots and the mean values of aggregated LVIS metrics, however, were not as strong. This discrepancy suggests that validation efforts must be cautious in using pre-existing field data networks as a sole means of calibrating and verifying such remote sensing data. Stratification based on land-use or species composition, however, did provide the means to improve regression relationships at this scale. Regression models established at the footprint level for AGBM and QMSD were applied to LVIS data to generate predicted values for the whole of Bartlett. The accuracy of these models was assessed using varying subsets of the USFS NERS plot data. Coefficient of determinations ranged from fair to strong with aspects of land-use history and species composition influencing both the fit and the level of error seen in the predicted relationships. (c) 2006 Elsevier Inc. All rights reserved. C1 Univ New Hampshire, Complex Syst Res Ctr, Durham, NH 03824 USA. US Forest Serv, NE Res Stn, USDA, Durham, NH 03824 USA. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Anderson, J (reprint author), Univ New Hampshire, Complex Syst Res Ctr, Durham, NH 03824 USA. EM jeanne.anderson@alumni.unh.edu RI Knox, Robert/E-9657-2011; Khachadourian, Diana/C-8513-2012; Blair, James/D-3881-2013; Beckley, Matthew/D-4547-2013 NR 47 TC 64 Z9 68 U1 3 U2 20 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD DEC 15 PY 2006 VL 105 IS 3 BP 248 EP 261 DI 10.1016/j.rse.2006.07.001 PG 14 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 111RZ UT WOS:000242473300007 ER PT J AU Brownlee, D Tsou, P Aleon, J Alexander, CMO Araki, T Bajt, S Baratta, GA Bastien, R Bland, P Bleuet, P Borg, J Bradley, JP Brearley, A Brenker, F Brennan, S Bridges, JC Browning, ND Brucato, JR Bullock, E Burchell, MJ Busemann, H Butterworth, A Chaussidon, M Cheuvront, A Chi, MF Cintala, MJ Clark, BC Clemett, SJ Cody, G Colangeli, L Cooper, G Cordier, P Daghlian, C Dai, ZR D'Hendecourt, L Djouadi, Z Dominguez, G Duxbury, T Dworkin, JP Ebel, DS Economou, TE Fakra, S Fairey, SAJ Fallon, S Ferrini, G Ferroir, T Fleckenstein, H Floss, C Flynn, G Franchi, IA Fries, M Gainsforth, Z Gallien, JP Genge, M Gilles, MK Gillet, P Gilmour, J Glavin, DP Gounelle, M Grady, MM Graham, GA Grant, PG Green, SF Grossemy, F Grossman, L Grossman, JN Guan, Y Hagiya, K Harvey, R Heck, P Herzog, GF Hoppe, P Horz, F Huth, J Hutcheon, ID Ignatyev, K Ishii, H Ito, M Jacob, D Jacobsen, C Jacobsen, S Jones, S Joswiak, D Jurewicz, A Kearsley, AT Keller, LP Khodja, H Kilcoyne, ALD Kissel, J Krot, A Langenhorst, F Lanzirotti, A Le, L Leshin, LA Leitner, J Lemelle, L Leroux, H Liu, MC Luening, K Lyon, I MacPherson, G Marcus, MA Marhas, K Marty, B Matrajt, G McKeegan, K Meibom, A Mennella, V Messenger, K Messenger, S Mikouchi, T Mostefaoui, S Nakamura, T Nakano, T Newville, M Nittler, LR Ohnishi, I Ohsumi, K Okudaira, K Papanastassiou, DA Palma, R Palumbo, ME Pepin, RO Perkins, D Perronnet, M Pianetta, P Rao, W Rietmeijer, FJM Robert, F Rost, D Rotundi, A Ryan, R Sandford, SA Schwandt, CS See, TH Schlutter, D Sheffield-Parker, J Simionovici, A Simon, S Sitnitsky, I Snead, CJ Spencer, MK Stadermann, FJ Steele, A Stephan, T Stroud, R Susini, J Sutton, SR Suzuki, Y Taheri, M Taylor, S Teslich, N Tomeoka, K Tomioka, N Toppani, A Trigo-Rodriguez, JM Troadec, D Tsuchiyama, A Tuzzolino, AJ Tyliszczak, T Uesugi, K Velbel, M Vellenga, J Vicenzi, E Vincze, L Warren, J Weber, I Weisberg, M Westphal, AJ Wirick, S Wooden, D Wopenka, B Wozniakiewicz, P Wright, I Yabuta, H Yano, H Young, ED Zare, RN Zega, T Ziegler, K Zimmerman, L Zinner, E Zolensky, M AF Brownlee, Don Tsou, Peter Aleon, Jerome Alexander, Conel M. O'D. Araki, Tohru Bajt, Sasa Baratta, Giuseppe A. Bastien, Ron Bland, Phil Bleuet, Pierre Borg, Janet Bradley, John P. Brearley, Adrian Brenker, F. Brennan, Sean Bridges, John C. Browning, Nigel D. Brucato, John R. Bullock, E. Burchell, Mark J. Busemann, Henner Butterworth, Anna Chaussidon, Marc Cheuvront, Allan Chi, Miaofang Cintala, Mark J. Clark, B. C. Clemett, Simon J. Cody, George Colangeli, Luigi Cooper, George Cordier, Patrick Daghlian, C. Dai, Zurong D'Hendecourt, Louis Djouadi, Zahia Dominguez, Gerardo Duxbury, Tom Dworkin, Jason P. Ebel, Denton S. Economou, Thanasis E. Fakra, Sirine Fairey, Sam A. J. Fallon, Stewart Ferrini, Gianluca Ferroir, T. Fleckenstein, Holger Floss, Christine Flynn, George Franchi, Ian A. Fries, Marc Gainsforth, Z. Gallien, J. -P. Genge, Matt Gilles, Mary K. Gillet, Philipe Gilmour, Jamie Glavin, Daniel P. Gounelle, Matthieu Grady, Monica M. Graham, Giles A. Grant, P. G. Green, Simon F. Grossemy, Faustine Grossman, Lawrence Grossman, Jeffrey N. Guan, Yunbin Hagiya, Kenji Harvey, Ralph Heck, Philipp Herzog, Gregory F. Hoppe, Peter Hoerz, Friedrich Huth, Joachim Hutcheon, Ian D. Ignatyev, Konstantin Ishii, Hope Ito, Motoo Jacob, Damien Jacobsen, Chris Jacobsen, Stein Jones, Steven Joswiak, David Jurewicz, Amy Kearsley, Anton T. Keller, Lindsay P. Khodja, H. Kilcoyne, A. L. David Kissel, Jochen Krot, Alexander Langenhorst, Falko Lanzirotti, Antonio Le, Loan Leshin, Laurie A. Leitner, J. Lemelle, L. Leroux, Hugues Liu, Ming-Chang Luening, K. Lyon, Ian MacPherson, Glen Marcus, Matthew A. Marhas, Kuljeet Marty, Bernard Matrajt, Graciela McKeegan, Kevin Meibom, Anders Mennella, Vito Messenger, Keiko Messenger, Scott Mikouchi, Takashi Mostefaoui, Smail Nakamura, Tomoki Nakano, T. Newville, M. Nittler, Larry R. Ohnishi, Ichiro Ohsumi, Kazumasa Okudaira, Kyoko Papanastassiou, Dimitri A. Palma, Russ Palumbo, Maria E. Pepin, Robert O. Perkins, David Perronnet, Murielle Pianetta, P. Rao, William Rietmeijer, Frans J. M. Robert, Francois Rost, D. Rotundi, Alessandra Ryan, Robert Sandford, Scott A. Schwandt, Craig S. See, Thomas H. Schlutter, Dennis Sheffield-Parker, J. Simionovici, Alexandre Simon, Steven Sitnitsky, I. Snead, Christopher J. Spencer, Maegan K. Stadermann, Frank J. Steele, Andrew Stephan, Thomas Stroud, Rhonda Susini, Jean Sutton, S. R. Suzuki, Y. Taheri, Mitra Taylor, Susan Teslich, Nick Tomeoka, Kazu Tomioka, Naotaka Toppani, Alice Trigo-Rodriguez, Josep M. Troadec, David Tsuchiyama, Akira Tuzzolino, Anthony J. Tyliszczak, Tolek Uesugi, K. Velbel, Michael Vellenga, Joe Vicenzi, E. Vincze, L. Warren, Jack Weber, Iris Weisberg, Mike Westphal, Andrew J. Wirick, Sue Wooden, Diane Wopenka, Brigitte Wozniakiewicz, Penelope Wright, Ian Yabuta, Hikaru Yano, Hajime Young, Edward D. Zare, Richard N. Zega, Thomas Ziegler, Karen Zimmerman, Laurent Zinner, Ernst Zolensky, Michael TI Comet 81P/Wild 2 under a microscope SO SCIENCE LA English DT Article ID CRYSTALLINE SILICATES; REFRACTORY INCLUSIONS; SOLAR NEBULA; KUIPER BELT; P/WILD 2; GRAINS; MINERALOGY; NUCLEUS; ORIGIN AB The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales. C1 Univ Washington, Dept Astron, Seattle, WA 98195 USA. 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Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Michigan State Univ, Dept Geol Sci, E Lansing, MI 48824 USA. Univ Ghent, B-9000 Ghent, Belgium. CUNY, Kingsborough Community Coll, Brooklyn, NY 11235 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. RP Brownlee, D (reprint author), Univ Washington, Dept Astron, Seattle, WA 98195 USA. EM brownlee@astro.washington.edu RI Leitner, Jan/A-7391-2015; Hoppe, Peter/B-3032-2015; Jacobsen, Chris/E-2827-2015; Tomioka, Naotaka/B-1888-2011; Chi, Miaofang/Q-2489-2015; Khodja, Hicham/A-1869-2016; Yabuta, Hikaru/M-9041-2014; Kilcoyne, David/I-1465-2013; Stroud, Rhonda/C-5503-2008; UCLA, SIMS/A-1459-2011; Liu, Ming-Chang/D-1885-2010; Dworkin, Jason/C-9417-2012; Chaussidon, Marc/E-7067-2017; Zare, Richard/A-8410-2009; Jacobsen, Stein/B-1759-2013; Glavin, Daniel/D-6194-2012; Green, Simon/C-7408-2009; Appourchaux, Thierry/F-4692-2010; McKeegan, Kevin/A-4107-2008; Dai, Zurong/E-6732-2010; Bajt, Sasa/G-2228-2010; Gilmour, Jamie/G-7515-2011; Fallon, Stewart/G-6645-2011; Heck, Philipp/C-6092-2012; Cordier, Patrick/D-2357-2012; Taheri, Mitra/F-1321-2011; Alexander, Conel/N-7533-2013 OI Burchell, Mark/0000-0002-2680-8943; Ignatyev, Konstantin/0000-0002-8937-5655; Palumbo, MariaElisabetta/0000-0002-9122-491X; Busemann, Henner/0000-0002-0867-6908; Baratta, Giuseppe/0000-0002-3688-160X; Grady, Monica/0000-0002-4055-533X; Gilmour, Jamie/0000-0003-1990-8636; Brucato, John Robert/0000-0002-4738-5521; Rotundi, Alessandra/0000-0001-5467-157X; Browning, Nigel/0000-0003-0491-251X; Leitner, Jan/0000-0003-3655-6273; Hoppe, Peter/0000-0003-3681-050X; Jacobsen, Chris/0000-0001-8562-0353; Tomioka, Naotaka/0000-0001-5725-9513; Chi, Miaofang/0000-0003-0764-1567; Yabuta, Hikaru/0000-0002-4625-5362; Stroud, Rhonda/0000-0001-5242-8015; Dworkin, Jason/0000-0002-3961-8997; Glavin, Daniel/0000-0001-7779-7765; McKeegan, Kevin/0000-0002-1827-729X; Fallon, Stewart/0000-0002-8064-5903; Cordier, Patrick/0000-0002-1883-2994; Alexander, Conel/0000-0002-8558-1427 NR 26 TC 552 Z9 554 U1 13 U2 137 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD DEC 15 PY 2006 VL 314 IS 5806 BP 1711 EP 1716 DI 10.1126/science.1135840 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 116WD UT WOS:000242833600041 PM 17170289 ER PT J AU Horz, F Bastien, R Borg, J Bradley, JP Bridges, JC Brownlee, DE Burchell, MJ Chi, MF Cintala, MJ Dai, ZR Djouadi, Z Dominguez, G Economou, TE Fairey, SAJ Floss, C Franchi, IA Graham, GA Green, SF Heck, P Hoppe, P Huth, J Ishii, H Kearsley, AT Kissel, J Leitner, J Leroux, H Marhas, K Messenger, K Schwandt, CS See, TH Snead, C Stadermann, FJ Stephan, T Stroud, R Teslich, N Trigo-Rodriguez, JM Tuzzolino, AJ Troadec, D Tsou, P Warren, J Westphal, A Wozniakiewicz, P Wright, I Zinner, E AF Hoerz, Friedrich Bastien, Ron Borg, Janet Bradley, John P. Bridges, John C. Brownlee, Donald E. Burchell, Mark J. Chi, Miaofang Cintala, Mark J. Dai, Zu Rong Djouadi, Zahia Dominguez, Gerardo Economou, Thanasis E. Fairey, Sam A. J. Floss, Christine Franchi, Ian A. Graham, Giles A. Green, Simon F. Heck, Philipp Hoppe, Peter Huth, Joachim Ishii, Hope Kearsley, Anton T. Kissel, Jochen Leitner, Jan Leroux, Hugues Marhas, Kuljeet Messenger, Keiko Schwandt, Craig S. See, Thomas H. Snead, Christopher Stadermann, Frank J. Stephan, Thomas Stroud, Rhonda Teslich, Nick Trigo-Rodriguez, Josep M. Tuzzolino, A. J. Troadec, David Tsou, Peter Warren, Jack Westphal, Andrew Wozniakiewicz, Penelope Wright, Ian Zinner, Ernst TI Impact features on Stardust: Implications for comet 81P/Wild 2 dust SO SCIENCE LA English DT Article ID SPACECRAFT; AEROGEL AB Particles emanating from comet 81P/ Wild 2 collided with the Stardust spacecraft at 6.1 kilometers per second, producing hypervelocity impact features on the collector surfaces that were returned to Earth. The morphologies of these surprisingly diverse features were created by particles varying from dense mineral grains to loosely bound, polymineralic aggregates ranging from tens of nanometers to hundreds of micrometers in size. The cumulative size distribution of Wild 2 dust is shallower than that of comet Halley, yet steeper than that of comet Grigg-Skjellerup. C1 NASA, Lyndon B Johnson Space Ctr, Engn Sci Contract Grp, Houston, TX 77058 USA. Inst Astrophys Spatiale, F-91405 Orsay, France. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Kent, Ctr Astrophys & Planetary Sci, Canterbury CT2 7NH, Kent, England. Univ Calif San Diego, Dept Chem & Biochem, La Jolla, CA 92093 USA. Univ Chicago, Enrico Fermi Inst, Lab Astrophys & Space Res, Chicago, IL 60637 USA. Washington Univ, Space Sci Lab, St Louis, MO 63160 USA. Max Planck Inst Chem, Particle Chem Dept, D-55020 Mainz, Germany. Nat Hist Museum, Dept Mineral, London SW7 5BD, England. Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau, Germany. Univ Munster, Inst Planetol, D-48149 Munster, Germany. Univ Lille, Lab Struct & Proprietes Etat Solide, F-59655 Villeneuve Dascq, France. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. USN, Res Lab, Washington, DC 20375 USA. CSIC, Inst Estudis Espacials Catalunya, Inst Space Sci, Barcelona 08193, Spain. Inst Estudis Espacials Catalunya, Barcelona 08034, Spain. Univ Lille, Inst Electron Microelectron & Nanotechnol, F-59655 Villeneuve Dascq, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Horz, F (reprint author), NASA, Lyndon B Johnson Space Ctr, Engn Sci Contract Grp, Houston, TX 77058 USA. EM friedrich.p.horz@jsc.nasa.gov RI Green, Simon/C-7408-2009; Dai, Zurong/E-6732-2010; Heck, Philipp/C-6092-2012; Leitner, Jan/A-7391-2015; Hoppe, Peter/B-3032-2015; Stroud, Rhonda/C-5503-2008; OI Leitner, Jan/0000-0003-3655-6273; Hoppe, Peter/0000-0003-3681-050X; Stroud, Rhonda/0000-0001-5242-8015; Burchell, Mark/0000-0002-2680-8943 NR 19 TC 192 Z9 193 U1 6 U2 35 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 15 PY 2006 VL 314 IS 5806 BP 1716 EP 1719 DI 10.1126/science.1135705 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 116WD UT WOS:000242833600042 PM 17170290 ER PT J AU Sandford, SA Aleon, J Alexander, CMO Araki, T Bajt, S Baratta, GA Borg, J Bradley, JP Brownlee, DE Brucato, JR Burchell, MJ Busemann, H Butterworth, A Clemett, SJ Cody, G Colangeli, L Cooper, G D'Hendecourt, L Djouadi, Z Dworkin, JP Ferrini, G Fleckenstein, H Flynn, GJ Franchi, IA Fries, M Gilles, MK Glavin, DP Gounelle, M Grossemy, F Jacobsen, C Keller, LP Kilcoyne, ALD Leitner, J Matrajt, G Meibom, A Mennella, V Mostefaoui, S Nittler, LR Palumbo, ME Papanastassiou, DA Robert, F Rotundi, A Snead, CJ Spencer, MK Stadermann, FJ Steele, A Stephan, T Tsou, P Tyliszczak, T Westphal, AJ Wirick, S Wopenka, B Yabuta, H Zare, RN Zolensky, ME AF Sandford, Scott A. Aleon, Jerome Alexander, Conel M. O'D. Araki, Tohru Bajt, Sasa Baratta, Giuseppe A. Borg, Janet Bradley, John P. Brownlee, Donald E. Brucato, John R. Burchell, Mark J. Busemann, Henner Butterworth, Anna Clemett, Simon J. Cody, George Colangeli, Luigi Cooper, George D'Hendecourt, Louis Djouadi, Zahia Dworkin, Jason P. Ferrini, Gianluca Fleckenstein, Holger Flynn, George J. Franchi, Ian A. Fries, Marc Gilles, Mary K. Glavin, Daniel P. Gounelle, Matthieu Grossemy, Faustine Jacobsen, Chris Keller, Lindsay P. Kilcoyne, A. L. David Leitner, Jan Matrajt, Graciela Meibom, Anders Mennella, Vito Mostefaoui, Smail Nittler, Larry R. Palumbo, Maria E. Papanastassiou, Dimitri A. Robert, Francois Rotundi, Alessandra Snead, Christopher J. Spencer, Maegan K. Stadermann, Frank J. Steele, Andrew Stephan, Thomas Tsou, Peter Tyliszczak, Tolek Westphal, Andrew J. Wirick, Sue Wopenka, Brigitte Yabuta, Hikaru Zare, Richard N. Zolensky, Michael E. TI Organics captured from comet 81P/Wild 2 by the Stardust spacecraft SO SCIENCE LA English DT Article ID INTERPLANETARY DUST PARTICLES; DIFFUSE INTERSTELLAR-MEDIUM; RAMAN-SPECTROSCOPY; ICE ANALOGS; MOLECULES; MATTER; IDENTIFICATION; CONSTRAINTS; CHONDRITES; METEORITES AB Organics found in comet 81P/ Wild 2 samples show a heterogeneous and unequilibrated distribution in abundance and composition. Some organics are similar, but not identical, to those in interplanetary dust particles and carbonaceous meteorites. A class of aromatic-poor organic material is also present. The organics are rich in oxygen and nitrogen compared with meteoritic organics. Aromatic compounds are present, but the samples tend to be relatively poorer in aromatics than are meteorites and interplanetary dust particles. The presence of deuterium and nitrogen-15 excesses suggest that some organics have an interstellar/ protostellar heritage. Although the variable extent of modification of these materials by impact capture is not yet fully constrained, a diverse suite of organic compounds is present and identifiable within the returned samples. C1 NASA, Ames Res Ctr, Astrophys Branch, Moffett Field, CA 94035 USA. Lawrence Livermore Natl Lab, Glenn I Seaborg Inst, Livermore, CA 94550 USA. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. Ctr Rech Petrog & Geochim, F-54501 Vandoeuvre Les Nancy, France. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Inst Astrophys Spatiale, F-91405 Orsay, France. Osserv Astrofis Catania, Ist Nazl Astrofis, I-95123 Catania, Italy. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Osserv Astron Capodimonte, INAF, I-80131 Naples, Italy. Univ Kent, Sch Phys Sci, Canterbury CT2 7NH, Kent, England. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Lyndon B Johnson Space Ctr, Expense Reduct Consulting Inc, Houston, TX 77058 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. NASA, Goddard Space Flight Ctr, Goddard Ctr Astrobiol, Greenbelt, MD 20771 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. SUNY Coll Plattsburgh, Dept Phys, Plattsburgh, NY 12901 USA. Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. Univ Calif Berkeley, Div Chem Sci, Berkeley, CA 94720 USA. Museum Natl Hist Nat, Lab Etud Mat Extraterr, Paris, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Munster, Inst Planetol, D-48149 Munster, Germany. CALTECH, Jet Prop Lab, Div Sci, Pasadena, CA 91109 USA. Univ Naples Parthenope, Dipartimento Sci Applicate, I-80133 Naples, Italy. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Washington Univ, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. RP Sandford, SA (reprint author), NASA, Ames Res Ctr, Astrophys Branch, Moffett Field, CA 94035 USA. EM ssandford@mail.arc.nasa.gov RI Zare, Richard/A-8410-2009; Appourchaux, Thierry/F-4692-2010; Bajt, Sasa/G-2228-2010; Glavin, Daniel/D-6194-2012; Alexander, Conel/N-7533-2013; Leitner, Jan/A-7391-2015; Jacobsen, Chris/E-2827-2015; Yabuta, Hikaru/M-9041-2014; Kilcoyne, David/I-1465-2013; Dworkin, Jason/C-9417-2012; OI Brucato, John Robert/0000-0002-4738-5521; Rotundi, Alessandra/0000-0001-5467-157X; Burchell, Mark/0000-0002-2680-8943; Glavin, Daniel/0000-0001-7779-7765; Alexander, Conel/0000-0002-8558-1427; Leitner, Jan/0000-0003-3655-6273; Jacobsen, Chris/0000-0001-8562-0353; Yabuta, Hikaru/0000-0002-4625-5362; Dworkin, Jason/0000-0002-3961-8997; Palumbo, MariaElisabetta/0000-0002-9122-491X; Busemann, Henner/0000-0002-0867-6908; Baratta, Giuseppe/0000-0002-3688-160X NR 29 TC 312 Z9 319 U1 8 U2 91 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 15 PY 2006 VL 314 IS 5806 BP 1720 EP 1724 DI 10.1126/science.1135841 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 116WD UT WOS:000242833600043 PM 17170291 ER PT J AU McKeegan, KD Aleon, J Bradley, J Brownlee, D Busemann, H Butterworth, A Chaussidon, M Fallon, S Floss, C Gilmour, J Gounelle, M Graham, G Guan, YB Heck, PR Hoppe, P Hutcheon, ID Huth, J Ishii, H Ito, M Jacobsen, SB Kearsley, A Leshin, LA Liu, MC Lyon, I Marhas, K Marty, B Matrajt, G Meibom, A Messenger, S Mostefaoui, S Mukhopadhyay, S Nakamura-Messenger, K Nittler, L Palma, R Pepin, RO Papanastassiou, DA Robert, F Schlutter, D Snead, CJ Stadermann, FJ Stroud, R Tsou, P Westphal, A Young, ED Ziegler, K Zimmermann, L Zinner, E AF McKeegan, Kevin D. Aleon, Jerome Bradley, John Brownlee, Donald Busemann, Henner Butterworth, Anna Chaussidon, Marc Fallon, Stewart Floss, Christine Gilmour, Jamie Gounelle, Matthieu Graham, Giles Guan, Yunbin Heck, Philipp R. Hoppe, Peter Hutcheon, Ian D. Huth, Joachim Ishii, Hope Ito, Motoo Jacobsen, Stein B. Kearsley, Anton Leshin, Laurie A. Liu, Ming-Chang Lyon, Ian Marhas, Kuljeet Marty, Bernard Matrajt, Graciela Meibom, Anders Messenger, Scott Mostefaoui, Smail Mukhopadhyay, Sujoy Nakamura-Messenger, Keiko Nittler, Larry Palma, Russ Pepin, Robert O. Papanastassiou, Dimitri A. Robert, Francois Schlutter, Dennis Snead, Christopher J. Stadermann, Frank J. Stroud, Rhonda Tsou, Peter Westphal, Andrew Young, Edward D. Ziegler, Karen Zimmermann, Laurent Zinner, Ernst TI Isotopic compositions of cometary matter returned by Stardust SO SCIENCE LA English DT Article ID INTERPLANETARY DUST PARTICLES; CRYSTALLINE SILICATES; HALE-BOPP; OXYGEN ISOTOPES; ORGANIC-MATTER; METEORITES; NITROGEN; PRESOLAR; ORIGIN; RATIOS AB Hydrogen, carbon, nitrogen, and oxygen isotopic compositions are heterogeneous among comet 81P/Wild 2 particle fragments; however, extreme isotopic anomalies are rare, indicating that the comet is not a pristine aggregate of presolar materials. Nonterrestrial nitrogen and neon isotope ratios suggest that indigenous organic matter and highly volatile materials were successfully collected. Except for a single O-17-enriched circumstellar stardust grain, silicate and oxide minerals have oxygen isotopic compositions consistent with solar system origin. One refractory grain is O-16-enriched, like refractory inclusions in meteorites, suggesting that Wild 2 contains material formed at high temperature in the inner solar system and transported to the Kuiper belt before comet accretion. C1 Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Ctr Spectrometrie Nucl & Spectrometrie Masse, F-91405 Orsay, France. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Glenn T Seaborg Inst, Livermore, CA 94550 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Carnegie Inst Sci, Dept Terr Magnetism, Washington, DC 20015 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Ctr Rech Petrog & Geochim, F-54501 Vandoeuvre Les Nancy, France. Washington Univ, Dept Phys, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. Univ Manchester, Sch Earth Atmospher & Environm Sci, Manchester M13 9PL, Lancs, England. Museum Natl Hist Nat, Lab Etud Mat Extraterr, F-75005 Paris, France. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Max Planck Inst Chem, Particle Chem Dept, D-55128 Mainz, Germany. NASA, Lyndon B Johnson Space Ctr, Robert M Walker Lab Space Sci, Astromat Res Explorat Sci Directorate, Houston, TX 77058 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Nat Hist Museum, Dept Mineral, Impacts & Astromat Res Ctr, London SW7 5BD, England. NASA, Goddard Space Flight Ctr, Sci & Explorat Directorate, Greenbelt, MD 20771 USA. Jacobs Sverdrup, Houston, TX 77058 USA. Minnesota State Univ, Dept Phys & Astron, Mankato, MN 56001 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. CALTECH, Jet Prop Lab, Div Sci, Pasadena, CA 91109 USA. USN, Res Lab, Washington, DC 20375 USA. RP McKeegan, KD (reprint author), Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. EM mckeegan@ess.ucla.edu RI McKeegan, Kevin/A-4107-2008; Gilmour, Jamie/G-7515-2011; Fallon, Stewart/G-6645-2011; Heck, Philipp/C-6092-2012; Jacobsen, Stein/B-1759-2013; Hoppe, Peter/B-3032-2015; Stroud, Rhonda/C-5503-2008; UCLA, SIMS/A-1459-2011; Liu, Ming-Chang/D-1885-2010; Chaussidon, Marc/E-7067-2017; OI McKeegan, Kevin/0000-0002-1827-729X; Fallon, Stewart/0000-0002-8064-5903; Hoppe, Peter/0000-0003-3681-050X; Stroud, Rhonda/0000-0001-5242-8015; Gilmour, Jamie/0000-0003-1990-8636; Busemann, Henner/0000-0002-0867-6908 NR 33 TC 249 Z9 250 U1 4 U2 48 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD DEC 15 PY 2006 VL 314 IS 5806 BP 1724 EP 1728 DI 10.1126/science.1135992 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 116WD UT WOS:000242833600044 PM 17170292 ER PT J AU Keller, LP Bajt, S Baratta, GA Borg, J Bradley, JP Brownlee, DE Busemann, H Brucato, JR Burchell, M Colangeli, L d'Hendecourt, L Djouadi, Z Ferrini, G Flynn, G Franchi, IA Fries, M Grady, MM Graham, GA Grossemy, F Kearsley, A Matrajt, G Nakamura-Messenger, K Mennella, V Nittler, L Palumbo, ME Stadermann, FJ Tsou, P Rotundi, A Sandford, SA Snead, C Steele, A Wooden, D Zolensky, M AF Keller, Lindsay P. Bajt, Sasa Baratta, Giuseppe A. Borg, Janet Bradley, John P. Brownlee, Don E. Busemann, Henner Brucato, John R. Burchell, Mark Colangeli, Luigi d'Hendecourt, Louis Djouadi, Zahia Ferrini, Gianluca Flynn, George Franchi, Ian A. Fries, Marc Grady, Monica M. Graham, Giles A. Grossemy, Faustine Kearsley, Anton Matrajt, Graciela Nakamura-Messenger, Keiko Mennella, Vito Nittler, Larry Palumbo, Maria E. Stadermann, Frank J. Tsou, Peter Rotundi, Alessandra Sandford, Scott A. Snead, Christopher Steele, Andrew Wooden, Diane Zolensky, Mike TI Infrared spectroscopy of comet 81P/Wild 2 samples returned by Stardust SO SCIENCE LA English DT Article ID DIFFUSE INTERSTELLAR-MEDIUM; ORGANIC-MATTER; HALE-BOPP; INTERPLANETARY DUST; GALACTIC-CENTER; MU-M; SPECTROPHOTOMETRY; CONSTRAINTS; SILICATES; GRAINS AB Infrared spectra of material captured from comet 81P/Wild 2 by the Stardust spacecraft reveal indigenous aliphatic hydrocarbons similar to those in interplanetary dust particles thought to be derived from comets, but with longer chain lengths than those observed in the diffuse interstellar medium. Similarly, the Stardust samples contain abundant amorphous silicates in addition to crystalline silicates such as olivine and pyroxene. The presence of crystalline silicates in Wild 2 is consistent with mixing of solar system and interstellar matter. No hydrous silicates or carbonate minerals were detected, which suggests a lack of aqueous processing of Wild 2 dust. C1 NASA, Lyndon B Johnson Space Ctr, Astromat Res & Explorat Sci Directorate, Houston, TX 77058 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Osserv Astrofis Catania, INAF, I-95123 Catania, Italy. Inst Astrophys Spatiale, F-91405 Orsay, France. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. Osserv Astron Capodimonte, INAF, I-80131 Naples, Italy. Univ Kent, Sch Phys Sci, Canterbury CT2 7NR, Kent, England. Novaetech SRL, I-80125 Naples, Italy. SUNY Coll Plattsburgh, Dept Phys, Plattsburgh, NY 12901 USA. Open Univ, Milton Keynes MK7 6AA, Bucks, England. Nat Hist Museum, Dept Mineral, London SW7 5BD, England. NASA, Lyndon B Johnson Space Ctr, Engn Sci Contract Grp, Houston, TX 77058 USA. Washington Univ, Space Sci Lab, St Louis, MO 63160 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Napoli Parthenope, Dipartimento Sci Applicate, I-80133 Naples, Italy. NASA, Ames Res Ctr, Astrophys Branch, Moffett Field, CA 94035 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Keller, LP (reprint author), NASA, Lyndon B Johnson Space Ctr, Astromat Res & Explorat Sci Directorate, Mail Code KR, Houston, TX 77058 USA. EM lindsay.p.keller@nasa.gov RI Appourchaux, Thierry/F-4692-2010; Bajt, Sasa/G-2228-2010; OI Grady, Monica/0000-0002-4055-533X; Palumbo, MariaElisabetta/0000-0002-9122-491X; Busemann, Henner/0000-0002-0867-6908; Baratta, Giuseppe/0000-0002-3688-160X; Brucato, John Robert/0000-0002-4738-5521; Rotundi, Alessandra/0000-0001-5467-157X; Burchell, Mark/0000-0002-2680-8943 NR 33 TC 117 Z9 118 U1 6 U2 24 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 15 PY 2006 VL 314 IS 5806 BP 1728 EP 1731 DI 10.1126/science.1135796 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 116WD UT WOS:000242833600045 PM 17170293 ER PT J AU Flynn, GJ Bleuet, P Borg, J Bradley, JP Brenker, FE Brennan, S Bridges, J Brownlee, DE Bullock, ES Burghammer, M Clark, BC Dai, ZR Daghlian, CP Djouadi, Z Fakra, S Ferroir, T Floss, C Franchi, IA Gainsforth, Z Gallien, JP Gillet, P Grant, PG Graham, GA Green, SF Grossemy, F Heck, PR Herzog, GF Hoppe, P Horz, F Huth, J Ignatyev, K Ishii, HA Janssens, K Joswiak, D Kearsley, AT Khodja, H Lanzirotti, A Leitner, J Lemelle, L Leroux, H Luening, K MacPherson, GJ Marhas, KK Marcus, MA Matrajt, G Nakamura, T Nakamura-Messenger, K Nakano, T Newville, M Papanastassiou, DA Pianetta, P Rao, W Riekel, C Rietmeijer, FJM Rost, D Schwandt, CS See, TH Sheffield-Parker, J Simionovici, A Sitnitsky, I Snead, CJ Stadermann, FJ Stephan, T Stroud, RM Susini, J Suzuki, Y Sutton, SR Taylor, S Teslich, N Troadec, D Tsou, P Tsuchiyama, A Uesugi, K Vekemans, B Vicenzi, EP Vincze, L Westphal, AJ Wozniakiewicz, P Zinner, E Zolensky, ME AF Flynn, George J. Bleuet, Pierre Borg, Janet Bradley, John P. Brenker, Frank E. Brennan, Sean Bridges, John Brownlee, Don E. Bullock, Emma S. Burghammer, Manfred Clark, Benton C. Dai, Zu Rong Daghlian, Charles P. Djouadi, Zahia Fakra, Sirine Ferroir, Tristan Floss, Christine Franchi, Ian A. Gainsforth, Zack Gallien, Jean-Paul Gillet, Philippe Grant, Patrick G. Graham, Giles A. Green, Simon F. Grossemy, Faustine Heck, Philipp R. Herzog, Gregory F. Hoppe, Peter Hoerz, Friedrich Huth, Joachim Ignatyev, Konstantin Ishii, Hope A. Janssens, Koen Joswiak, David Kearsley, Anton T. Khodja, Hicham Lanzirotti, Antonio Leitner, Jan Lemelle, Laurence Leroux, Hugues Luening, Katharina MacPherson, Glenn J. Marhas, Kuljeet K. Marcus, Matthew A. Matrajt, Graciela Nakamura, Tomoki Nakamura-Messenger, Keiko Nakano, Tsukasa Newville, Matthew Papanastassiou, Dimitri A. Pianetta, Piero Rao, William Riekel, Christian Rietmeijer, Frans J. M. Rost, Detlef Schwandt, Craig S. See, Thomas H. Sheffield-Parker, Julie Simionovici, Alexandre Sitnitsky, Ilona Snead, Christopher J. Stadermann, Frank J. Stephan, Thomas Stroud, Rhonda M. Susini, Jean Suzuki, Yoshio Sutton, Stephen R. Taylor, Susan Teslich, Nick Troadec, D. Tsou, Peter Tsuchiyama, Akira Uesugi, Kentaro Vekemans, Bart Vicenzi, Edward P. Vincze, Laszlo Westphal, Andrew J. Wozniakiewicz, Penelope Zinner, Ernst Zolensky, Michael E. TI Elemental compositions of comet 81P/Wild 2 samples collected by Stardust SO SCIENCE LA English DT Article ID SPACECRAFT; ABUNDANCES; SOLAR; DUST AB We measured the elemental compositions of material from 23 particles in aerogel and from residue in seven craters in aluminum foil that was collected during passage of the Stardust spacecraft through the coma of comet 81P/Wild 2. These particles are chemically heterogeneous at the largest size scale analyzed (similar to 180 ng). The mean elemental composition of this Wild 2 material is consistent with the CI meteorite composition, which is thought to represent the bulk composition of the solar system, for the elements Mg, Si, Mn, Fe, and Ni to 35%, and for Ca and Ti to 60%. The elements Cu, Zn, and Ga appear enriched in this Wild 2 material, which suggests that the CI meteorites may not represent the solar system composition for these moderately volatile minor elements. C1 SUNY Coll Plattsburgh, Dept Phys, Plattsburgh, NY 12901 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Inst Astrophys Spatiale, Orsay, France. Goethe Univ Frankfurt, Inst Mineral, D-6000 Frankfurt, Germany. Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Open Univ, Milton Keynes MK7 6AA, Bucks, England. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. Lockheed Martin, Denver, CO 80201 USA. Dartmouth Coll, Hanover, NH 03755 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Ecole Normale Super Lyon, F-69364 Lyon, France. Washington Univ, St Louis, MO 63130 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. CNRS, CEA, Lab Pierre Sue, Saclay, France. Max Planck Inst Chem, D-55128 Mainz, Germany. Rutgers State Univ, Dept Chem & Biol Chem, Piscataway, NJ 08854 USA. NASA, Lyndon B Johnson Space Ctr, Engn & Sci Contract Grp Jacobs Sverdrup, Houston, TX 77058 USA. Univ Antwerp, Dept Chem, B-2020 Antwerp, Belgium. Nat Hist Museum, Dept Mineral, London SW7 5BD, England. Univ Chicago, Chicago, IL 60637 USA. Univ Munster, Inst Planetol, D-48149 Munster, Germany. Univ Lille, Lille, France. Kyushu Univ, Fukuoka 812, Japan. Geol Survey Japan, Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 305, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Georgia, Athens, GA 30602 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. XRT Ltd, Port Melbourne, Vic, Australia. USN, Res Lab, Washington, DC 20375 USA. Japan Synchrotron Radiat Res Inst SPring8, Hyogo, Japan. Cold Reg Res & Engn Lab, Engn Res & Dev Ctr, Hanover, NH 03755 USA. Univ Ghent, B-9000 Ghent, Belgium. Osaka Univ, Toyonaka, Osaka 560, Japan. RP Flynn, GJ (reprint author), SUNY Coll Plattsburgh, Dept Phys, 101 Broad St, Plattsburgh, NY 12901 USA. EM george.flynn@plattsburgh.edu RI Stroud, Rhonda/C-5503-2008; Green, Simon/C-7408-2009; Dai, Zurong/E-6732-2010; Heck, Philipp/C-6092-2012; Leitner, Jan/A-7391-2015; Hoppe, Peter/B-3032-2015; Khodja, Hicham/A-1869-2016; Janssens, Koen/B-8049-2011; OI Stroud, Rhonda/0000-0001-5242-8015; Leitner, Jan/0000-0003-3655-6273; Hoppe, Peter/0000-0003-3681-050X; Janssens, Koen/0000-0002-6752-6408; Ignatyev, Konstantin/0000-0002-8937-5655 NR 17 TC 154 Z9 154 U1 2 U2 36 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 15 PY 2006 VL 314 IS 5806 BP 1731 EP 1735 DI 10.1126/science.1136141 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 116WD UT WOS:000242833600046 PM 17170294 ER PT J AU Zolensky, ME Zega, TJ Yano, H Wirick, S Westphal, AJ Weisberg, MK Weber, I Warren, JL Velbel, MA Tsuchiyama, A Tsou, P Toppani, A Tomioka, N Tomeoka, K Teslich, N Taheri, M Susini, J Stroud, R Stephan, T Stadermann, FJ Snead, CJ Simon, SB Simionovici, A See, TH Robert, F Rietmeijer, FJM Rao, W Perronnet, MC Papanastassiou, DA Okudaira, K Ohsumi, K Ohnishi, I Nakamura-Messenger, K Nakamura, T Mostefaoui, S Mikouchi, T Meibom, A Matrajt, G Marcus, MA Leroux, H Lemelle, L Le, L Lanzirotti, A Langenhorst, F Krot, AN Keller, LP Kearsley, AT Joswiak, D Jacob, D Ishii, H Harvey, R Hagiya, K Grossman, L Grossman, JN Graham, GA Gounelle, M Gillet, P Genge, MJ Flynn, G Ferroir, T Fallon, S Ebel, DS Dai, ZR Cordier, P Clark, B Chi, MF Butterworth, AL Brownlee, DE Bridges, JC Brennan, S Brearley, A Bradley, JP Bleuet, P Bland, PA Bastien, R AF Zolensky, Michael E. Zega, Thomas J. Yano, Hajime Wirick, Sue Westphal, Andrew J. Weisberg, Mike K. Weber, Iris Warren, Jack L. Velbel, Michael A. Tsuchiyama, Akira Tsou, Peter Toppani, Alice Tomioka, Naotaka Tomeoka, Kazushige Teslich, Nick Taheri, Mitra Susini, Jean Stroud, Rhonda Stephan, Thomas Stadermann, Frank J. Snead, Christopher J. Simon, Steven B. Simionovici, Alexandre See, Thomas H. Robert, Francois Rietmeijer, Frans J. M. Rao, William Perronnet, Murielle C. Papanastassiou, Dimitri A. Okudaira, Kyoko Ohsumi, Kazumasa Ohnishi, Ichiro Nakamura-Messenger, Keiko Nakamura, Tomoki Mostefaoui, Smail Mikouchi, Takashi Meibom, Anders Matrajt, Graciela Marcus, Matthew A. Leroux, Hugues Lemelle, Laurence Le, Loan Lanzirotti, Antonio Langenhorst, Falko Krot, Alexander N. Keller, Lindsay P. Kearsley, Anton T. Joswiak, David Jacob, Damien Ishii, Hope Harvey, Ralph Hagiya, Kenji Grossman, Lawrence Grossman, Jeffrey N. Graham, Giles A. Gounelle, Matthieu Gillet, Philippe Genge, Matthew J. Flynn, George Ferroir, Tristan Fallon, Stewart Ebel, Denton S. Dai, Zu Rong Cordier, Patrick Clark, Benton Chi, Miaofang Butterworth, Anna L. Brownlee, Donald E. Bridges, John C. Brennan, Sean Brearley, Adrian Bradley, John P. Bleuet, Pierre Bland, Phil A. Bastien, Ron TI Report - Mineralogy and petrology of comet 81P/Wild 2 nucleus samples SO SCIENCE LA English DT Article ID INTERPLANETARY DUST PARTICLES; CARBONACEOUS CHONDRITE; SOLAR-SYSTEM; COMPONENTS; PYROXENE; OLIVINE; MATRIX; GRAINS; ORIGIN; HALLEY AB The bulk of the comet 81P/Wild 2 ( hereafter Wild 2) samples returned to Earth by the Stardust spacecraft appear to be weakly constructed mixtures of nanometer-scale grains, with occasional much larger ( over 1 micrometer) ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal, and accessory phases. The very wide range of olivine and low-Ca pyroxene compositions in comet Wild 2 requires a wide range of formation conditions, probably reflecting very different formation locations in the protoplanetary disk. The restricted compositional ranges of Fe-Ni sulfides, the wide range for silicates, and the absence of hydrous phases indicate that comet Wild 2 experienced little or no aqueous alteration. Less abundant Wild 2 materials include a refractory particle, whose presence appears to require radial transport in the early protoplanetary disk. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. USN, Res Lab, Washington, DC 20375 USA. JAXA ISAS, Kanagawa 2298510, Japan. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. CUNY, Kingsborough Community Coll, Dept Phys Sci, Brooklyn, NY 11235 USA. Univ Munster, Inst Planetol, D-48149 Munster, Germany. JAcobs Scerdrup, Engn Sci Contract Grp, Houston, TX 77058 USA. Michigan State Univ, Dept Geol Sci, E Lansing, MI 48824 USA. Osaka Univ, Dept Earth & Space Sci, Toyonaka, Osaka 5600043, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Ctr Spectrometrie Nucl & Spectrometrie Masse, F-91405 Orsay, France. Kobe Univ, Fac Sci, Dept Earth & Planetary Sci, Nada Ku, Kobe, Hyogo 6578501, Japan. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Ecole Normale Super Lyon, Lab Sci Terre, F-69007 Lyon, France. ARES JSC, Engn Sci Contract Barrios Technol, Houston, TX 77258 USA. Museum Natl Hist Nat, Lab Etude Mat Extraterr, LEME, F-75005 Paris, France. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Savannah River Ecol Lab, Aiken, SC 29801 USA. CALTECH, Jet Prop Lab, Div Sci, Pasadena, CA 91109 USA. Inst Mat Struct Sci, Tsukuba, Ibaraki 305, Japan. Kyushu Univ, Fac Sci, Dept Earth & Planetary Sci, Fukuoka 8128581, Japan. Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Sci & Tech Lille, Lab Struct & Proprietes Etat Solide, F-59655 Villeneuve Dascq, France. Univ Chicago, Consortium Adv Radiat Source, Chicago, IL 60637 USA. Univ Jena, Inst Geosci, D-07749 Jena, Germany. Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Nat Hist Museum, Impact & Astromat Res Ctr, Dept Mineral, London SW7 5BD, England. Case Western Reserve Univ, Dept Geol, Cleveland, OH 44106 USA. Univ Hyogo, Grad Sch Life Sci, Kamigori, Hyogo 6781297, Japan. Univ Jena, Inst Geosci, D-07749 Jena, Germany. Nat Hist Museum, Impact & Astromat Res Ctr, Dept Mineral, London SW7 5BD, England. Case Western Reserve Univ, Dept Geol, Cleveland, OH 44106 USA. Univ Hyogo, Grad Sch Life Sci, Kamigori, Hyogo 6781297, Japan. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. US Geol Survey, Reston, VA 20192 USA. Univ London Imperial Coll Sci Technol & Med, Impact & Astromat Res Ctr, Dept Earth Sci & Engn, London SW7 2AZ, England. SUNY Coll Plattsburgh, Dept Phys, Plattsburgh, NY 12901 USA. Amer Museum Nat Hist, Dept Earth & Planetary Sci, New York, NY 10024 USA. Lockheed Martin Astronaut, Denver, CO 80201 USA. Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Zolensky, ME (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM michael.e.zolensky@nasa.gov RI Dai, Zurong/E-6732-2010; Fallon, Stewart/G-6645-2011; Cordier, Patrick/D-2357-2012; Taheri, Mitra/F-1321-2011; Tomioka, Naotaka/B-1888-2011; U-ID, Kyushu/C-5291-2016; Stroud, Rhonda/C-5503-2008 OI Fallon, Stewart/0000-0002-8064-5903; Cordier, Patrick/0000-0002-1883-2994; Tomioka, Naotaka/0000-0001-5725-9513; Stroud, Rhonda/0000-0001-5242-8015 NR 35 TC 436 Z9 438 U1 9 U2 58 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 15 PY 2006 VL 314 IS 5806 BP 1735 EP 1739 DI 10.1126/science.1135842 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 116WD UT WOS:000242833600047 PM 17170295 ER PT J AU Sibert, J Hampton, J Kleiber, P Maunder, M AF Sibert, John Hampton, John Kleiber, Pierre Maunder, Mark TI Biomass, size, and trophic status of top predators in the Pacific Ocean SO SCIENCE LA English DT Article AB Fisheries have removed at least 50 million tons of tuna and other top-level predators from the Pacific Ocean pelagic ecosystem since 1950, leading to concerns about a catastrophic reduction in population biomass and the collapse of oceanic food chains. We analyzed all available data from Pacific tuna fisheries for 1950-2004 to provide comprehensive estimates of fishery impacts on population biomass and size structure. Current biomass ranges among species from 36 to 91% of the biomass predicted in the absence of fishing, a level consistent with or higher than standard fisheries management targets. Fish larger than 175 centimeters fork length have decreased from 5% to approximately 1% of the total population. The trophic level of the catch has decreased slightly, but there is no detectable decrease in the trophic level of the population. These results indicate substantial, though not catastrophic, impacts of fisheries on these top-level predators and minor impacts on the ecosystem in the Pacific Ocean. C1 Univ Hawaii, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. Secretariat Pacific Community, Ocean Fisheries Programme, Noumea 98848, New Caledonia. NOAA, Pacific Isl Fisheries Sci Ctr, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA. Interamer Trop Tuna Commiss, La Jolla, CA 92037 USA. RP Sibert, J (reprint author), Univ Hawaii, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. EM sibert@hawaii.edu NR 1 TC 137 Z9 141 U1 5 U2 40 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 15 PY 2006 VL 314 IS 5806 BP 1773 EP 1776 DI 10.1126/science.1135347 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 116WD UT WOS:000242833600058 PM 17170304 ER PT J AU Froidevaux, L Livesey, NJ Read, WG Salawitch, RJ Waters, JW Drouin, B MacKenzie, IA Pumphrey, HC Bernath, P Boone, C Nassar, R Montzka, S Elkins, J Cunnold, D Waugh, D AF Froidevaux, L. Livesey, N. J. Read, W. G. Salawitch, R. J. Waters, J. W. Drouin, B. MacKenzie, I. A. Pumphrey, H. C. Bernath, P. Boone, C. Nassar, R. Montzka, S. Elkins, J. Cunnold, D. Waugh, D. TI Temporal decrease in upper atmospheric chlorine SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; AURA SATELLITE; EOS MLS; AGE; AIR AB We report a steady decrease in the upper stratospheric and lower mesospheric abundances of hydrogen chloride (HCl) from August 2004 through January 2006, as measured by the Microwave Limb Sounder (MLS) aboard the Aura satellite. For 60 degrees S to 60 degrees N zonal means, the average yearly change in the 0.7 to 0.1 hPa (similar to 50 to 65 km) region is similar to 27 +/- 3 pptv/year, or similar to 0.78 +/- 0.08 percent/year. This is consistent with surface abundance decrease rates (about 6 to 7 years earlier) in chlorine source gases. The MLS data confirm that international agreements to reduce global emissions of ozone-depleting industrial gases are leading to global decreases in the total gaseous chlorine burden. Tracking stratospheric HCl variations on a seasonal basis is now possible with MLS data. Inferred stratospheric total chlorine (Cl-TOT) has a value of 3.60 ppbv at the beginning of 2006, with a (2-sigma) accuracy estimate of 7%; the stratospheric chlorine loading has decreased by about 43 pptv in the 18-month period studied here. We discuss the MLS HCl measurements in the context of other satellite-based HCl data, as well as expectations from surface chlorine data. A mean age of air of similar to 5.5 years and an age spectrum width of 2 years or less provide a fairly good fit to the ensemble of measurements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Edinburgh, Sch Geosci, Edinburgh EH9 3JN, Midlothian, Scotland. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. NOAA, Off Ocean & Atmospher Res, Boulder, CO 80305 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. RP Froidevaux, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM lucien@mls.jpl.nasa.gov RI Salawitch, Ross/B-4605-2009; Bernath, Peter/B-6567-2012; mackenzie, ian/E-9320-2013; OI Salawitch, Ross/0000-0001-8597-5832; Bernath, Peter/0000-0002-1255-396X; Montzka, Stephen/0000-0002-9396-0400; Nassar, Ray/0000-0001-6282-1611 NR 20 TC 39 Z9 39 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 14 PY 2006 VL 33 IS 23 AR L23812 DI 10.1029/2006GL027600 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 118KX UT WOS:000242942300003 ER PT J AU Fehsenfeld, FC Ancellet, G Bates, TS Goldstein, AH Hardesty, RM Honrath, R Law, KS Lewis, AC Leaitch, R McKeen, S Meagher, J Parrish, DD Pszenny, AAP Russell, PB Schlager, H Seinfeld, J Talbot, R Zbinden, R AF Fehsenfeld, F. C. Ancellet, G. Bates, T. S. Goldstein, A. H. Hardesty, R. M. Honrath, R. Law, K. S. Lewis, A. C. Leaitch, R. McKeen, S. Meagher, J. Parrish, D. D. Pszenny, A. A. P. Russell, P. B. Schlager, H. Seinfeld, J. Talbot, R. Zbinden, R. TI International Consortium for Atmospheric Research on Transport and Transformation (ICARTT): North America to Europe - Overview of the 2004 summer field study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID MARINE BOUNDARY-LAYER; LONG-RANGE TRANSPORT; NORTHEASTERN UNITED-STATES; AEROSOL MASS-SPECTROMETER; ATLANTIC FLIGHT CORRIDOR; AIRCRAFT EXHAUST PLUMES; IN-SITU MEASUREMENTS; LIQUID SAMPLER PILS; NONMETHANE HYDROCARBONS; AIRBORNE MEASUREMENTS AB [1] In the summer of 2004 several separate field programs intensively studied the photochemical, heterogeneous chemical and radiative environment of the troposphere over North America, the North Atlantic Ocean, and western Europe. Previous studies have indicated that the transport of continental emissions, particularly from North America, influences the concentrations of trace species in the troposphere over the North Atlantic and Europe. An international team of scientists, representing over 100 laboratories, collaborated under the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) umbrella to coordinate the separate field programs in order to maximize the resulting advances in our understanding of regional air quality, the transport, chemical transformation and removal of aerosols, ozone, and their precursors during intercontinental transport, and the radiation balance of the troposphere. Participants utilized nine aircraft, one research vessel, several ground-based sites in North America and the Azores, a network of aerosol-ozone lidars in Europe, satellites, balloon borne sondes, and routine commercial aircraft measurements. In this special section, the results from a major fraction of those platforms are presented. This overview is aimed at providing operational and logistical information for those platforms, summarizing the principal findings and conclusions that have been drawn from the results, and directing readers to specific papers for further details. C1 NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA. Univ Paris 06, Serv Aeron, CNRS, Inst Pierre Simon Laplace, F-75252 Paris, France. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA. Michigan Technol Univ, Dept Civil & Environm Engn, Houghton, MI 49931 USA. Environm Canada, Sci & Technol Branch, Toronto, ON M3H 5T4, Canada. Univ York, Dept Chem, York YO10 5DD, N Yorkshire, England. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Deutsch Zentrum Luft & Raumfahrt, D-82230 Wessling, Germany. CALTECH, Dept Environm Sci & Engn, Pasadena, CA 91125 USA. CALTECH, Dept Chem Engn, Pasadena, CA 91125 USA. Univ Toulouse 3, Lab Aerol, UMR 5560 CNRS, Observ Midi Pyrenees, F-31400 Toulouse, France. RP Fehsenfeld, FC (reprint author), NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA. EM david.d.parrish@noaa.gov RI McKeen, Stuart/H-9516-2013; Parrish, David/E-8957-2010; Lewis, Alastair/A-6721-2008; Goldstein, Allen/A-6857-2011; Fehsenfeld, Frederick/I-4876-2013; Hardesty, Robert/H-9844-2013; Bates, Timothy/L-6080-2016; Manager, CSD Publications/B-2789-2015 OI Parrish, David/0000-0001-6312-2724; Lewis, Alastair/0000-0002-4075-3651; Goldstein, Allen/0000-0003-4014-4896; NR 204 TC 118 Z9 121 U1 0 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 14 PY 2006 VL 111 IS D23 AR D23S01 DI 10.1029/2006JD007829 PG 36 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 118LC UT WOS:000242942800006 ER PT J AU Folkins, I Bernath, P Boone, C Donner, LJ Eldering, A Lesins, G Martin, RV Sinnhuber, BM Walker, K AF Folkins, Ian Bernath, P. Boone, C. Donner, L. J. Eldering, A. Lesins, Glen Martin, R. V. Sinnhuber, B. -M. Walker, K. TI Testing convective parameterizations with tropical measurements of HNO3, CO, H2O, and O-3: Implications for the water vapor budget SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHEMICAL-TRANSPORT MODELS; IN-SITU OBSERVATIONS; CUMULUS CONVECTION; UPPER TROPOSPHERE; STRATOSPHERIC OZONE; VERTICAL STRUCTURE; CROSS-TROPOPAUSE; DEEP CONVECTION; MASS FLUXES; CLOUD AB [1] The updraft and downdraft mass flux profiles generated by convective parameterizations differ significantly from each other. Most convective parameterizations are tested against temperature and relative humidity profiles from radiosondes. Chemical tracers provide important additional constraints on the vertical redistribution of mass by convective parameterizations. We compile tropical climatologies of water vapor (H2O), ozone (O-3), carbon monoxide (CO), and nitric acid (HNO3) from a variety of satellite, aircraft, and balloon-based measurement platforms. These climatologies are compared with the profiles predicted by a variant of the Emanuel convective parameterization, a two-column model of the tropical atmosphere, and by the implementations of the Relaxed Arakawa Schubert (RAS) and Zhang and McFarlane (ZM) parameterizations in a three-dimensional global forecast model. In general, the models with more pronounced convective outflow in the upper troposphere compare more favorably with observations. These models are associated with increased evaporative moistening in the middle and lower troposphere. C1 Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS B3H 3J5, Canada. Univ Bremen, Inst Environm Phys, D-28359 Bremen, Germany. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Princeton Univ, Geophys Fluid Dynam Lab, NOAA, Princeton, NJ 08540 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Folkins, I (reprint author), Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS B3H 3J5, Canada. EM ian.folkins@dal.ca RI Martin, Randall/A-2051-2008; Bernath, Peter/B-6567-2012; Sinnhuber, Bjorn-Martin/A-7007-2013; Martin, Randall/C-1205-2014 OI Bernath, Peter/0000-0002-1255-396X; Sinnhuber, Bjorn-Martin/0000-0001-9608-7320; Martin, Randall/0000-0003-2632-8402 NR 54 TC 36 Z9 36 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 14 PY 2006 VL 111 IS D23 AR D23304 DI 10.1029/2006JD007325 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 118LC UT WOS:000242942800005 ER PT J AU Gove, JM Merrifield, MA Brainard, RE AF Gove, Jamison M. Merrifield, Mark A. Brainard, Russell E. TI Temporal variability of current-driven upwelling at Jarvis Island SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID TAHITI SHUTTLE EXPERIMENT; PACIFIC; HAWAII; OCEAN; WATER; FLOW; REEF AB The temporal variability of upwelling on the western side of Jarvis Island, caused by the island blocking of free stream currents, is investigated using in situ and shipboard observations. Variations in upwelling are related to changes in the strength and depth of the Equatorial Undercurrent (EUC) caused by wind-forcing at different timescales. Seasonally, the strongest upwelling at Jarvis occurs in boreal spring when a weakening of the trade winds in the eastern and central Pacific coincides with a locally shallow thermocline and shallow and strong EUC. Year to year differences in springtime upwelling are associated with the strength of the trade winds in the western Pacific; intensified trade winds associated with La Nina conditions favor the shoaling of the thermocline and the EUC at Jarvis. On intraseasonal timescales, upwelling events at Jarvis are linked to local trade wind bursts, which cause a regional upwelling that also enhances EUC-driven upwelling. Strong (>1.00 m s(-1)) near-surface eastward currents measured at Jarvis, associated with trade wind relaxations in the central Pacific, are downwelling favorable. During periods of EUC-driven upwelling, interactions of the semidiurnal tide with Jarvis result in abrupt cold spikes (1-4 degrees C) that tend to occur at similar to 12 hour period. Tidal currents and temperature fluctuate 180 degrees out of phase, such that minimum temperatures coincide with maximum eastward current. The high-frequency upwelling appears to be most consistent with the presence of internal tides. C1 Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. NOAA, Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Coral Reef Ecosyst Div, Honolulu, HI USA. RP Gove, JM (reprint author), Univ Hawaii Manoa, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. EM jamison.gove@noaa.gov NR 21 TC 16 Z9 17 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 14 PY 2006 VL 111 IS C12 AR C12011 DI 10.1029/2005JC003161 PG 10 WC Oceanography SC Oceanography GA 118LQ UT WOS:000242944200001 ER PT J AU Bahcivan, H Hysell, DL Lummerzheim, D Larsen, MF Pfaff, RF AF Bahcivan, H. Hysell, D. L. Lummerzheim, D. Larsen, M. F. Pfaff, R. F. TI Observations of colocated optical and radar aurora SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID E-REGION; ELECTRIC-FIELDS; EVENING SECTOR; ARC; IRREGULARITIES; MAGNETOSPHERE; IONOSPHERE; SIMULATION; REFRACTION; CURRENTS AB This article presents case studies of common volume observations of the E region radar aurora obtained with a 30 MHz imaging radar and the optical aurora ( green line emissions) recorded by an all sky camera. In addition, in situ rocket electric field measurements in the vicinity of an auroral arc are presented in a separate case study. As inferred from the measurements, the radar aurora in the vicinity of a stable evening auroral arc arises because of the arc's polarization electric fields, which excite the two stream instability and generate electron density irregularities at meter scales. The radar aurora is the backscattering of radar waves from these irregularities. C1 SRI Int, Ctr Geospace Studies, Menlo Pk, CA 94025 USA. Cornell Univ, Dept Earth & Atmospher Sci, Ithaca, NY 14853 USA. Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK 99775 USA. Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bahcivan, H (reprint author), SRI Int, Ctr Geospace Studies, 333 Ravenswood Ave,G287, Menlo Pk, CA 94025 USA. EM hasan.bahcivan@sri.com; daveh@geology.cornell.edu RI Larsen, Miguel/A-1079-2013; Pfaff, Robert/F-5703-2012 OI Pfaff, Robert/0000-0002-4881-9715 NR 22 TC 6 Z9 6 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 14 PY 2006 VL 111 IS A12 AR A12308 DI 10.1029/JA011923 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118NN UT WOS:000242949100004 ER PT J AU Robertson, IP Collier, MR Cravens, TE Fok, MC AF Robertson, I. P. Collier, M. R. Cravens, T. E. Fok, M. -C. TI X-ray emission from the terrestrial magnetosheath including the cusps SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND INTERACTION; CHARGE-TRANSFER; CHANDRA OBSERVATIONS; MAGNETOPAUSE MOTION; TEMPORAL VARIATIONS; COMET HYAKUTAKE; HEAVY-IONS; TEMPERATURES; MAGNETOSPHERE; SIMULATION AB X rays are produced throughout the terrestrial magnetosheath as a consequence of charge transfer collisions between heavy solar wind ions and exospheric neutrals. The solar wind ions resulting from these collisions are left in highly excited states and emit extreme ultraviolet or soft X-ray photons. We previously simulated X-ray images of the magnetosheath as seen from an observation point outside the geocorona for average solar wind conditions. The locations of the bow shock and magnetopause were evident in these images, but the cusps were not taken into account. For the current paper we used dynamic three-dimensional MHD simulations of the solar wind, magnetosheath, and magnetosphere for the 31 March 2001 geomagnetic storm. A sky map was generated of the expected X-ray emissions as seen by a hypothetical X-ray detector on the IMAGE spacecraft. Modeled images as seen from an observation point well outside the geocorona were also created. The cusps can clearly be detected in both types of simulated images. Images of the magnetosheath in energy neutral atoms (ENA) also show the cusps. X-ray imaging of the magnetosheath, revealing the structure of the magnetopause and the bow shock, if carried out, could potentially make a valuable contribution to our understanding of the solar wind interaction with the magnetosheath. C1 Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Robertson, IP (reprint author), Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. EM robertin@ku.edu RI Fok, Mei-Ching/D-1626-2012; Collier, Michael/I-4864-2013 OI Collier, Michael/0000-0001-9658-6605 NR 37 TC 24 Z9 24 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 14 PY 2006 VL 111 IS A12 AR A12105 DI 10.1029/2006JA011672 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118NN UT WOS:000242949100002 ER PT J AU Watters, TR Leuschen, CJ Plaut, JJ Picardi, G Safaeinili, A Clifford, SM Farrell, WM Ivanov, AB Phillips, RJ Stofan, ER AF Watters, Thomas R. Leuschen, Carl J. Plaut, Jeffrey J. Picardi, Giovanni Safaeinili, Ali Clifford, Stephen M. Farrell, William M. Ivanov, Anton B. Phillips, Roger J. Stofan, Ellen R. TI MARSIS radar sounder evidence of buried basins in the northern lowlands of Mars SO NATURE LA English DT Article ID CRUSTAL DICHOTOMY; GIANT IMPACT; MANTLE; ORIGIN AB A hemispheric dichotomy on Mars is marked by the sharp contrast between the sparsely cratered northern lowland plains and the heavily cratered southern highlands. Mechanisms proposed to remove ancient crust or form younger lowland crust include one or more giant impacts, subcrustal transport by mantle convection, the generation of thinner crust by plate tectonics, and mantle overturn following solidification of an early magma ocean(1-7). The age of the northern lowland crust is a significant constraint on these models. The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument on the European Space Agency's Mars Express spacecraft is providing new constraints on the martian subsurface(8). Here we show evidence of buried impact basins ranging in diameter from about 130 km to 470 km found over 14 per cent of the northern lowlands. The number of detected buried basins >200 km in diameter indicates that the lowland crust is ancient, dating back to the Early Noachian epoch. This crater density is a lower limit because of the likelihood that not all buried basins in the area surveyed by MARSIS have been detected. An Early Noachian age for the lowland crust has been previously suggested on the basis of a large number of quasi-circular topographic depressions interpreted to be evidence of buried basins(9-11). Only a few of these depressions in the area surveyed by MARSIS, however, correlate with the detected subsurface echoes. On the basis of the MARSIS data, we conclude that the northern lowland crust is at least as old as the oldest exposed highland crust. This suggests that the crustal dichotomy formed early in the geologic evolution of Mars. C1 Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. Univ Kansas, Ctr Remote Sensing Ice Sheets, Lawrence, KS 66045 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Roma La Sapienza, Infocom Dept, I-00184 Rome, Italy. Lunar & Planetary Inst, Houston, TX 77058 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Proxemy Res, Laytonville, MD 20882 USA. RP Watters, TR (reprint author), Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. EM watterst@si.edu RI Farrell, William/I-4865-2013; Ivanov, Anton/C-8944-2014 OI Ivanov, Anton/0000-0001-8376-8581 NR 22 TC 30 Z9 30 U1 1 U2 5 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD DEC 14 PY 2006 VL 444 IS 7121 BP 905 EP 908 DI 10.1038/nature05356 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 116LW UT WOS:000242805400050 PM 17167480 ER PT J AU Sun, WB Loeb, NG Davies, R Loukachine, K Miller, WF AF Sun, Wenbo Loeb, Norman G. Davies, Roger Loukachine, Konstantin Miller, Walter F. TI Comparison of MISR and CERES top-of-atmosphere albedo SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EARTH RADIATION BUDGET; ENERGY SYSTEM CERES; ALGORITHM; CLOUDS; INSTRUMENT; SATELLITE; ERBE AB The Clouds and the Earth's Radiant Energy System (CERES) and the Multi-angle Imaging SpectroRadiometer (MISR) on Terra satellite measure the Earth's top-of-atmosphere (TOA) albedo in broadband and narrowband, respectively. This study presents the first direct comparison of the CERES and MISR albedos. An algorithm for converting the MISR spectral albedos to broadband is derived. The MISR and CERES albedos for overcast ocean scenes are compared between 75 degrees S-75 degrees N for solar zenith angles <= 75 degrees. For overcast 1 degrees x 1 degrees ocean regions, the relative differences and the relative root-mean-square (RMS) differences between the MISR and CERES albedos are similar to 0.8% and similar to 4.3%, respectively. Accounting for a similar to 2.0% error in the MISR albedos due to narrow-to-broadband albedo conversion errors, the RMS difference between the MISR and CERES albedos due to angular distribution model (ADM) differences is estimated to be similar to 3.8%. The remarkable consistency between the CERES and MISR albedos for overcast oceans suggests that both instrument teams have derived accurate corrections for the radiance anisotropy of cloud scenes. This consistency will strongly enhance the confidence in the temporal trends of cloud albedo measured by the CERES and have significant impact on climate studies. C1 Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Auckland, Dept Phys, Auckland 1020, New Zealand. Sci Applicat Int Corp, Hampton, VA 23666 USA. RP Sun, WB (reprint author), Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. EM w.sun@larc.nasa.gov RI Davies, Roger/D-4296-2009 OI Davies, Roger/0000-0002-2991-0409 NR 18 TC 9 Z9 9 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 13 PY 2006 VL 33 IS 23 AR L23810 DI 10.1029/2006GL027958 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 118KW UT WOS:000242942200004 ER PT J AU Kelly, NJ Boynton, WV Kerry, K Hamara, D Janes, D Reedy, RC Kim, KJ Haberle, RM AF Kelly, N. J. Boynton, W. V. Kerry, K. Hamara, D. Janes, D. Reedy, R. C. Kim, K. J. Haberle, R. M. TI Seasonal polar carbon dioxide frost on Mars: CO2 mass and columnar thickness distribution SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article AB [ 1] Conclusions are drawn about the column density (g/cm(2)), spatial extent, and mass of the seasonal carbon dioxide frost on the poles of Mars as a function of time utilizing data from the 2001 Mars Odyssey Gamma Ray Spectrometer (GRS). Quantification of these CO2 values is achieved by observing attenuation effects of the surface-emitted hydrogen gamma ray flux as the frost condenses and sublimates in a seasonal exchange of CO2 between the ground and the atmosphere. Columnar thickness and mass results are discussed and plotted for latitudes including +/- 60 degrees and poleward. GRS observations are compared to predictions from the NASA Ames Research Center General Circulation Model and to similar experimental results from the Mars Odyssey High Energy Neutron Detector and Neutron Spectrometer. Models for north and south polar atmosphere and regolith distributions are incorporated, and our results indicate that the assumption of a 100% H2O-ice residual cap underlying the seasonal frost in the north is accurate. The GRS CO2 frost observations are in good agreement with the other studies mentioned, in particular for the timing of the beginning of frost deposition to the complete sublimation of surface CO2 back into the atmosphere. The total amount of condensed carbon dioxide mass seen by the GRS is on the order of 6.0 x 10(15) kg and verifies previous reports that nearly 25% of the Martian CO2 reservoir participates in the ground-atmosphere exchange cycle. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ New Mexico, Inst Meteorit, Albuquerque, NM 87131 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Kelly, NJ (reprint author), Univ Arizona, Lunar & Planetary Lab, 1629 E Univ Blvd, Tucson, AZ 85721 USA. EM nkelly@lpl.arizona.edu; wboynton@lpl.arizona.edu; krisk@lpl.arizona.edu; daveh@lpl.arizona.edu; buck@lpl.arizona.edu; rreedy@unm.edu; kkim@lpl.arizona.edu; robert.m.haberle@nasa.gov OI Kim, Kyeong J/0000-0001-6220-8411 NR 19 TC 33 Z9 33 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 13 PY 2006 VL 111 IS E3 AR E03S07 DI 10.1029/2006JE002678 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 133UR UT WOS:000244039900004 ER PT J AU Richardson, JD Liu, Y Wang, C McComas, DJ Stone, EC Cummings, AC Burlaga, LF Acuna, MH Ness, NF AF Richardson, J. D. Liu, Y. Wang, C. McComas, D. J. Stone, E. C. Cummings, A. C. Burlaga, L. F. Acuna, M. H. Ness, N. F. TI Source and consequences of a large shock near 79 AU SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TERMINATION SHOCK; OUTER HELIOSPHERE; VOYAGER-1; HELIOSHEATH AB In March 2006, Voyager 2 (V2) observed a large interplanetary (IP) shock near 79 AU followed by a merged interaction region (MIR). This shock is comparable to the shock observed by V2 at 65 AU in October 2001; these two shocks are the largest observed by V2 since 1991 when V2 was at 35 AU. This shock provides the first opportunity to compare the plasma structure in an IP shock and MIR with the energetic particle fluxes in the termination shock (TS) foreshock region. The flux of >0.5 MeV particles observed by V2 decreased after the shock; the shock and MIR probably pushed the TS outward so that the foreshock region moved outside the distance of V2. The >70 MeV cosmic ray ions decreased in the MIR, probably due to the reduced inward transport caused by the enhanced magnetic field. We model two possible sources of this shock, fast streams from polar coronal holes and coronal mass ejections (CMEs); these sources, when combined, provide a reasonable match to the V2 data. C1 MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. Chinese Acad Sci, Ctr Space Sci & Appl Res, State Key Lab Space Weather, Beijing 100080, Peoples R China. SW Res Inst, San Antonio, TX 78228 USA. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Lab Geospace Phys, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. RP Richardson, JD (reprint author), MIT, Kavli Inst Astrophys & Space Res, 37-655, Cambridge, MA 02139 USA. EM jdr@space.mit.edu; liuxying@space.mit.edu; cw@spaceweather.ac.cn; dmccomas@swri.edu; ecs@srl.caltech.edu; ace@srl.caltech.edu; leonard.f.burlaga@nasa.gov; mario.acuna@nasa.gov; nfnudel@yahoo.com OI Liu, Ying/0000-0002-3483-5909 NR 18 TC 26 Z9 26 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 12 PY 2006 VL 33 IS 23 AR L23107 DI 10.1029/2006GL027983 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 118KV UT WOS:000242942100007 ER PT J AU Cooper, OR Stohl, A Trainer, M Thompson, AM Witte, JC Oltmans, SJ Morris, G Pickering, KE Crawford, JH Chen, G Cohen, RC Bertram, TH Wooldridge, P Perring, A Brune, WH Merrill, J Moody, JL Tarasick, D Nedelec, P Forbes, G Newchurch, MJ Schmidlin, FJ Johnson, BJ Turquety, S Baughcum, SL Ren, X Fehsenfeld, FC Meagher, JF Spichtinger, N Brown, CC McKeen, SA McDermid, IS Leblanc, T AF Cooper, O. R. Stohl, A. Trainer, M. Thompson, A. M. Witte, J. C. Oltmans, S. J. Morris, G. Pickering, K. E. Crawford, J. H. Chen, G. Cohen, R. C. Bertram, T. H. Wooldridge, P. Perring, A. Brune, W. H. Merrill, J. Moody, J. L. Tarasick, D. Nedelec, P. Forbes, G. Newchurch, M. J. Schmidlin, F. J. Johnson, B. J. Turquety, S. Baughcum, S. L. Ren, X. Fehsenfeld, F. C. Meagher, J. F. Spichtinger, N. Brown, C. C. McKeen, S. A. McDermid, I. S. Leblanc, T. TI Large upper tropospheric ozone enhancements above midlatitude North America during summer: In situ evidence from the IONS and MOZAIC ozone measurement network SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INDUCED FLUORESCENCE DETECTION; DISPERSION MODEL FLEXPART; UNITED-STATES; NITROGEN-OXIDES; ATLANTIC-OCEAN; REACTIVE NITROGEN; TRANSPORT MODELS; ATMOSPHERIC NO2; BOUNDARY-LAYER; ART. AB The most extensive set of free tropospheric ozone measurements ever compiled across midlatitude North America was measured with daily ozonesondes, commercial aircraft and a lidar at 14 sites during July-August 2004. The model estimated stratospheric ozone was subtracted from all profiles, leaving a tropospheric residual ozone. On average the upper troposphere above midlatitude eastern North America contained 15 ppbv more tropospheric residual ozone than the more polluted layer between the surface and 2 km above sea level. Lowest ozone values in the upper troposphere were found above the two upwind sites in California. The upper troposphere above midlatitude eastern North America contained 16 ppbv more tropospheric residual ozone than the upper troposphere above three upwind sites, with the greatest enhancement above Houston, Texas, at 24 ppbv. Upper tropospheric CO measurements above east Texas show no statistically significant enhancement compared to west coast measurements, arguing against a strong influence from fresh surface anthropogenic emissions to the upper troposphere above Texas where the ozone enhancement is greatest. Vertical mixing of ozone from the boundary layer to the upper troposphere can only account for 2 ppbv of the 16 ppbv ozone enhancement above eastern North America; therefore the remaining 14 ppbv must be the result of in situ ozone production. The transport of NOx tracers from North American anthropogenic, biogenic, biomass burning, and lightning emissions was simulated for the upper troposphere of North America with a particle dispersion model. Additional box model calculations suggest the 24 ppbv ozone enhancement above Houston can be produced over a 10 day period from oxidation reactions of lightning NOx and background mixing ratios of CO and CH4. Overall, we estimate that 69-84% (11-13 ppbv) of the 16 ppbv ozone enhancement above eastern North America is due to in situ ozone production from lightning NOx with the remainder due to transport of ozone from the surface or in situ ozone production from other sources of NOx. C1 NOAA, Earth Syst Res Lab, Div Chem Sci, Theoret Aeron Branch, Boulder, CO 80305 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Boeing Co, Seattle, WA 98124 USA. Meteorol Serv Canada, Sable Isl, NS B3J 2L4, Canada. CALTECH, Jet Prop Lab, Wrightwood, CA 92397 USA. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA. Observ Midi Pyrenees, Lab Aerol, CNRS, F-31400 Toulouse, France. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Wallops Isl, VA 23337 USA. Tech Univ Munich, Dept Ecol, D-80333 Freising Weihenstephan, Germany. Norwegian Inst Air Res, N-2027 Kjeller, Norway. Environm Canada, Meteorol Serv Canada, Expt Studies Res Div, Toronto, ON M3H 5T4, Canada. Univ Paris 06, Inst Pierre Simon Laplace, Serv Aeron, F-75005 Paris, France. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20770 USA. RP Cooper, OR (reprint author), NOAA, Earth Syst Res Lab, Div Chem Sci, Theoret Aeron Branch, CSD04,325 Broadway, Boulder, CO 80305 USA. EM owen.r.cooper@noaa.gov RI Thompson, Anne /C-3649-2014; Manager, CSD Publications/B-2789-2015; Stohl, Andreas/A-7535-2008; Cohen, Ronald/A-8842-2011; Ren, Xinrong/B-2229-2010; Pickering, Kenneth/E-6274-2012; Perring, Anne/G-4597-2013; Cooper, Owen/H-4875-2013; Trainer, Michael/H-5168-2013; McKeen, Stuart/H-9516-2013; Fehsenfeld, Frederick/I-4876-2013; Crawford, James/L-6632-2013; Ren, Xinrong/E-7838-2015; OI Thompson, Anne /0000-0002-7829-0920; Stohl, Andreas/0000-0002-2524-5755; Cohen, Ronald/0000-0001-6617-7691; Perring, Anne/0000-0003-2231-7503; Crawford, James/0000-0002-6982-0934; Ren, Xinrong/0000-0001-9974-1666; Tarasick, David/0000-0001-9869-0692 NR 57 TC 67 Z9 69 U1 3 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 12 PY 2006 VL 111 IS D24 AR D24S05 DI 10.1029/2006JD007306 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 118LE UT WOS:000242943000001 ER PT J AU Casares, J Cornelisse, R Steeghs, D Charles, PA Hynes, RI O'Brien, K Strohmayer, TE AF Casares, J. Cornelisse, R. Steeghs, D. Charles, P. A. Hynes, R. I. O'Brien, K. Strohmayer, T. E. TI Detection of the irradiated donor in the LMXBs 4U 1636-536 (=V801 Ara) and 4U 1735-444 (=V926 Sco) SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion; accretion discs; binaries : close; stars : individual : V801 Ara; stars : individual : V926 Sco; X-rays : binaries ID X-RAY BINARIES; ORBITAL PERIOD; BOWEN FLUORESCENCE; NEUTRON-STAR; SCORPIUS X-1; MASS; EMISSION; SPECTROSCOPY; PHOTOMETRY; X1735-444 AB Phase-resolved VLT spectroscopy of the bursting low-mass X-ray binaries 4U 1636-536/V801 Ara and 4U 1735-444/V926 Sco is presented. Doppler images of the N-III lambda 4640 Bowen transition reveal compact spots which we attribute to fluorescent emission from the donor star and enable us to define a new set of spectroscopic ephemerides. We measure K-em = 277 +/- 22 and 226 +/- 22 km s(-1) from the N III spots in V801 Ara and V926 Sco, respectively, which represent strict lower limits to the radial velocity semi-amplitude of the donor stars. Our new ephemerides provide confirmation that light-curve maxima in V801 Ara and likely V926 Sco occur at superior conjunction of the donor star and hence photometric modulation is caused by the visibility of the X-ray heated donor. The velocities of He it lambda 4686 and the broad Bowen blend are strongly modulated with the orbital period, with phasing supporting emission dominated by the disc bulge. In addition, a reanalysis of burst oscillations in V801 Ara, using our spectroscopic T-0, leads to K-1 = 90-113 km s(-1). We also estimate the K-corrections for all possible disc flaring angles and present the first dynamical constraints on the masses of these X-ray bursters. These are K-2 = 360 +/- 74 km s(-1),f (M) = 0.76 +/- 0.47 M-circle dot and q = 0.21-0.34 for V801 Ara and K-2 = 298 +/- 83 km s(-1) ,f(M) = 0.53 +/- 0.44 M-circle dot and q = 0.05-0.41 for V926 Sco. Disc flaring angles alpha >= 12 degrees and q similar or equal to 0.26-0.34 are favoured for V801 Ara whereas the lack of K, constraint for V926 Sco prevents tight constraints on this system. Although both binaries seem to have intermediate inclinations, the larger equivalent width of the narrow N III line in V801 Ara at phase 0.5 relative to phase 0 suggests that it has the higher inclination of the two. C1 Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Tenerife, Spain. Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. S African Astron Observ, ZA-7935 Cape Town, South Africa. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. European So Observ, Santiago 19, Chile. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Casares, J (reprint author), Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Tenerife, Spain. EM jcv@iac.es; comelis@astro.soton.ac.uk; dsteeghs@head.cfa.harvard.edu; pac@saao.ac.za; rih@phys.lsu.edu; kobrien@eso.org; stroh@clarence.gsfc.nasa.gov RI Steeghs, Danny/C-5468-2009 OI Steeghs, Danny/0000-0003-0771-4746 NR 40 TC 49 Z9 49 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 11 PY 2006 VL 373 IS 3 BP 1235 EP 1244 DI 10.1111/j.1365-2966.2006.11106.x PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 121JC UT WOS:000243152900024 ER PT J AU Shi, Y Rieke, GH Hines, DC Gorjian, V Werner, MW Cleary, K Low, FJ Smith, PS Bouwman, J AF Shi, Y. Rieke, G. H. Hines, D. C. Gorjian, V. Werner, M. W. Cleary, K. Low, F. J. Smith, P. S. Bouwman, J. TI 9.7 mu m Silicate features in active galactic nuclei: New insights into unification models SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : nuclei ID SPITZER-SPACE-TELESCOPE; QUASI-STELLAR OBJECTS; II RADIO GALAXIES; XMM-NEWTON OBSERVATIONS; OBSCURING DUST TORI; X-RAY-PROPERTIES; INFRARED SPECTROGRAPH; MIDINFRARED SPECTRA; THICK TORI; EMISSION AB We describe observations of 9.7 mu m silicate features in 97 AGNs, exhibiting a wide range of AGN types and of X-ray extinction toward the central nuclei. We find that the strength of the silicate feature correlates with the H I column density estimated from fitting the X-ray data, such that low H I columns correspond to silicate emission, while high columns correspond to silicate absorption. The behavior is generally consistent with unification models in which the large diversity in AGN properties is caused by viewing-angle-dependent obscuration of the nucleus. Radio-loud AGNs and radio-quiet quasars follow roughly the correlation between H I columns and the strength of the silicate feature defined by Seyfert galaxies. The agreement among AGN types suggests a high-level unification with similar characteristics for the structure of the obscuring material. We demonstrate the implications for unification models qualitatively with a conceptual disk model. The model includes an inner accretion disk (< 0.1 pc in radius), a middle disk (0.1-10 pc in radius) with a dense diffuse component and with embedded denser clouds, and an outer clumpy disk (10-300 pc in radius). C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Space Sci Inst, Boulder, CO 80301 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. RP Shi, Y (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA. NR 47 TC 114 Z9 115 U1 0 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP 127 EP 136 DI 10.1086/508737 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AG UT WOS:000242913800009 ER PT J AU Grupe, D Burrows, DN Patel, SK Kouveliotou, C Zhang, B Meszaros, P Wijers, RAM Gehrels, N AF Grupe, Dirk Burrows, David N. Patel, Sandeep K. Kouveliotou, Chryssa Zhang, Bing Meszaros, Peter Wijers, Ralph A. M. Gehrels, Neil TI Jet breaks in short gamma-ray bursts. I. The uncollimated afterglow of GRB 050724 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; X-rays : individual (GRB 050724) ID HOST GALAXY; ENGINE ACTIVITY; LIGHT CURVES; BLACK-HOLES; TELESCOPE; ENERGETICS; FLARES; ORIGIN; DISCOVERY; MISSION AB We report the results of the Chandra observations of the Swift-discovered short gamma-ray burst GRB 050724. Chandra observed this burst twice, about 2 days after the burst and a second time 3 weeks later. The first Chandra pointing occurred at the end of a strong late-time flare. About 150 photons were detected during this 49.3 ks observation in the 0.4-10.0 keV range. The spectral fit is in good agreement with spectral analysis of earlier Swift XRT data. In the second Chandra pointing the afterglow was clearly detected with eight background-subtracted photons in 44.6 ks. From the combined Swift XRT and Chandra-ACIS-S light curve we find significant flaring superposed on an underlying power-law decay slope of alpha = 0.98(-0.09)(+0.11). There is no evidence for a break between about 1 ks after the burst and the last Chandra pointing about 3 weeks afterthe burst. The tiondetection of ajet break places a lower limit of 25 degrees on the jet opening angle, indicating that the outflow is less strongly collimated than most previously reported long GRBs. This implies that the beaming corrected energy of GRB 050724 is at least 4 x 1049 ergs. C1 Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. NASA, George C Marshall Space Flight Ctr, Natl Space Sci Technol Ctr, Huntsville, AL 35805 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Grupe, D (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. RI Gehrels, Neil/D-2971-2012 NR 52 TC 78 Z9 78 U1 0 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP 462 EP 467 DI 10.1086/508739 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AG UT WOS:000242913800036 ER PT J AU Burrows, DN Grupe, D Capalbi, M Panaitescu, A Patel, SK Kouveliotou, C Zhang, B Meszaros, P Chincarini, G Gehrels, N Wijers, RAM AF Burrows, David N. Grupe, Dirk Capalbi, Milvia Panaitescu, Alin Patel, Sandeep K. Kouveliotou, Chryssa Zhang, Bing Meszaros, Peter Chincarini, Guido Gehrels, Neil Wijers, Ralph A. M. TI Jet breaks in short gamma-ray bursts. II. The collimated afterglow of GRB 051221A SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts ID NEUTRON-STARS; HOST GALAXY; TELESCOPE; GRB-050709; ENERGETICS; NUCLEOSYNTHESIS; CONSTRAINTS; EMISSION; BINARIES; OUTFLOWS AB We report the best evidence to date of a jet break in a short gamma-ray burst (GRB) afterglow, using Chandra and Swift XRT observations of the X-ray afterglow of GRB 051221A. The combined X-ray light curve, which has three breaks, is similar to those commonly observed in Swift observations of long GRBs. A flat segment of the light curve at similar to 0.1 days after the burst represents the first clear case of strong energy injection in the external shock of a short GRB afterglow. The last break in the light curve occurs at similar to 4 days postburst and breaks to a power-law decay index of similar to 2. We interpret this as a jet break, with important implications for models of short GRBs, since it requires collimation of the afterglow into a jet with an initial opening angle theta(0) similar to 4 degrees-8 degrees and implies a total jet kinetic energy of E-jet similar to (1-5) x 10(49) ergs. Combined with the lack of a jet break in GRB 050724, this suggests a wide range in jet collimation in short GRBs, with at least some having collimation similar to that found in long GRBs, although with significantly lower jet energies. C1 Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. ASI, Sci Data Ctr, I-00044 Frascati, Italy. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. NASA, Natl Space Sci Technol Ctr, Marshall Space Flight Ctr, Huntsville, AL 35805 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Osserv Astron Brera, INAF, Merate 23807, Italy. Univ Milan, Dipartimento Fis, I-20126 Milan, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. RP Burrows, DN (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. EM burrows@astro.psu.edu RI Gehrels, Neil/D-2971-2012 NR 38 TC 98 Z9 99 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP 468 EP 473 DI 10.1086/508740 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AG UT WOS:000242913800037 ER PT J AU Strohmayer, TE Watts, AL AF Strohmayer, Tod E. Watts, Anna L. TI The 2004 hyperflare from SGR 1806-20: Further evidence for global torsional vibrations SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : individual (SGR 1806-20); stars : magnetic fields; stars : neutron; stars : oscillations; stars : rotation; X-rays : stars ID X-RAY OSCILLATIONS; ROTATING SPHERICAL-SHELLS; SOFT GAMMA-REPEATERS; NEUTRON-STAR; GIANT-FLARE; RADIATIVE MECHANISM; SGR 1806-20; CONSTRAINTS; DISCOVERY; STABILITY AB We report an analysis of archival RXTE data from the 2004 December hyperflare from SGR 1806-20. In addition to the approximate to 90 Hz QPO first discovered by Israel et al., we report the detection of higher frequency oscillations at approximate to 150, 625, and 1840 Hz. We also find evidence of oscillations at; 720, and 2384 Hz, but with lower significances. The 150 Hz QPO has a width (FWHM) of about 17 Hz, an average amplitude (rms) of 6.8% and is associated with the strongest peak in the pulse profile. The 625 Hz oscillation was detected in an average power spectrum from nine Successive cycles beginning approximately 180 s after the initial hard spike. It has a width (FWHM) of approximate to 2 Hz and an average amplitude (rms) during this interval of 8.5%. We find a strong detection of the 625 Hz oscillation in a pair of successive rotation cycles beginning about 230 s after the start of the flare. In these cycles we also detect the 1840 Hz QPO. When the 625 Hz QPO is detected we also confirm the simultaneous presence of 30 and 92 Hz QPOs. The centroid frequency of the 625 Hz QPO detected with RXTE is within 1 Hz of the 626 Hz oscillation recently found in RHESSI data by Watts & Strohmayer. We argue that these new findings provide further evidence for a connection of these oscillations with global oscillation modes of neutron stars, in particular, the high-frequency signals may represent toroidal modes with at least one radial node in the crust. We discuss their implications in the context of this model and for the depth of neutron star crusts. C1 NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. Max Planck Inst Astrophys, D-85741 Garching, Germany. RP Strohmayer, TE (reprint author), NASA, Goddard Space Flight Ctr, Explorat Universe Div, Code 661, Greenbelt, MD 20771 USA. EM stroh@milkyway.gsfc.nasa.gov; anna@mpa-garching.mpg.de NR 22 TC 106 Z9 106 U1 1 U2 7 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP 593 EP 601 DI 10.1086/508703 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AG UT WOS:000242913800050 ER PT J AU Liu, JF Di Stefano, R McClintock, J Kong, A Bregman, J Kuntz, K AF Liu, Jifeng Di Stefano, Rosanne McClintock, Jeffrey Kong, Albert Bregman, Joel Kuntz, Kip TI Discovery of an eclipsing X-ray binary with a 32.69 hr period in M101: An analog of Her X-1 or LMC X-4? SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (M101); X-rays : binaries ID SOURCE POPULATION; SPACED DATA; CHANDRA; GALAXIES; REMNANTS; UHURU; M31 AB We report the discovery of an eclipsing X-ray binary in M 101, the first such system to be discovered outside the Local Group. Based on a sequence of 25 Chandra observations that sample a wide range of orbital phases, we find a period of 32.688 +/- 0.002 hr, which we interpret as an orbital period. The folded light curve exhibits an eclipse lasting about 8 hr, suggesting a compact orbit in a nearly edge-on configuration. The X-ray binary has an average luminosity of L-X(0.3-8 keV) approximate to 1.3 x 10(38) ergs s(-1), with only 1 out of the 25 observations significantly lower in flux than the average light curve. The presence of the eclipse and the similar to 1.4 day orbital period suggests that this source is an analog of the well-studied eclipsing X-ray binary pulsars Her X-1 or LMC X-4. Combining the Chandra data and the HST ACS/WFC images, we have identified several possible optical counterparts, including an O5-O3 star with V = 25.0 mag. Follow-up optical monitoring observations should be able to identify the donor and further constrain the orbital properties. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Cambridge, MA 02139 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Johns Hopkins Univ, Goddard Space Flight Ctr, Baltimore, MD USA. RP Liu, JF (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 33 TC 4 Z9 4 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP 602 EP 612 DI 10.1086/508447 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AG UT WOS:000242913800051 ER PT J AU Su, KYL Rieke, GH Stansberry, JA Bryden, G Stapelfeldt, KR Trilling, DE Muzerolle, J Beichman, CA Moro-Martin, A Hines, DC Werner, MW AF Su, K. Y. L. Rieke, G. H. Stansberry, J. A. Bryden, G. Stapelfeldt, K. R. Trilling, D. E. Muzerolle, J. Beichman, C. A. Moro-Martin, A. Hines, D. C. Werner, M. W. TI Debris disk evolution around a stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; planetary systems : formation ID MAIN-SEQUENCE STARS; INNER SOLAR-SYSTEM; VEGA-LIKE STARS; OPEN CLUSTERS; TERRESTRIAL PLANETS; AGE-DEPENDENCE; MOVING GROUP; ORIGIN; SPITZER; SPECTROSCOPY AB We report 24 and/or 70 mu m measurements of similar to 160 A-type main-sequence stars using the Multiband Imaging Photometer for Spitzer (MIPS). Their ages range from 5 to 850 Myr, based on estimates from the literature (cluster or moving group associations) or from the H-R diagram and isochrones. The thermal infrared excess is identified by comparing the deviation (similar to 3% and similar to 15% at the 1 sigma or level at 24 and 70 mu m, respectively) between the measurements and the synthetic Kurucz photospheric predictions. Stars showing excess infrared emission due to strong emission lines or extended nebulosity seen at 24 mu m are excluded from our sample; therefore, the remaining infrared excesses are likely to arise from circumstellar debris disks. At the 3 sigma, confidence level, the excess rate at 24 and 70 mu m is 32% and >= 33% (with an uncertainty of 5%), considerably higher than what has been found for old solar analogs and M dwarfs. Our measurements place constraints on the fractional dust luminosities and temperatures in the disks. We find that older stars tend to have lower fractional dust luminosity than younger ones. While the fractional luminosity from the excess infrared emission follows a general 1/t relationship, the values at a given stellar age vary by at least 2 orders of magnitude. We also find that (1) older stars possess a narrow range of temperature distribution peaking at colder temperatures, and (2) the disk emission at 70 mu m persists longer than that at 24 pm. Both results suggest that the debris disk clearing process is more effective in the inner regions. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Michelson Sci Ct, Pasadena, CA 91125 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08540 USA. Space Sci Inst, Boulder, CO 80301 USA. RP Su, KYL (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA. EM ksu@as.arizona.edu RI Stapelfeldt, Karl/D-2721-2012; OI Su, Kate/0000-0002-3532-5580 NR 45 TC 229 Z9 230 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP 675 EP 689 DI 10.1086/508649 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AG UT WOS:000242913800057 ER PT J AU Bonev, BP Mumma, MJ DiSanti, MA Dello Russo, N Magee-Sauer, K Ellis, RS Stark, DP AF Bonev, Boncho P. Mumma, Michael J. DiSanti, Michael A. Dello Russo, Neil Magee-Sauer, Karen Ellis, Richard S. Stark, Daniel P. TI A comprehensive study of infrared OH prompt emission in two comets. I. Observations and effective g-factors SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; comets : individual (C/2000 WM1 LINEAR], C/2004 Q2 [Machholz]); infrared : solar system; molecular data ID O1 HALE-BOPP; C/1995 O1; WATER PRODUCTION; ULTRAVIOLET BANDS; CARBON-MONOXIDE; SPECTRUM; LEE; PHOTODISSOCIATION; FLUORESCENCE; TEMPERATURE AB We present high-dispersion infrared spectra of hydroxyl (OH) in comets C/2000 WM1 (LINEAR) and C/2004 Q2 (Machholz), acquired with the Near Infrared Echelle Spectrograph at the Keck Observatory atop Mauna Kea, Hawaii. Most of these rovibrational transitions result from photodissociative excitation of H2O giving rise to OH "prompt" emission. We present calibrated emission efficiencies (equivalent g-factors, measured in OH photons s(-1) [H2O molecule](-1)) for more than 20 OH lines sampled in these two comets. The OH transitions analyzed cover a broad range of rotational excitation. This infrared database for OH can be used in two principal ways: (1) as an indirect tool for obtaining water production in comets simultaneously with the production of other parent volatiles, even when direct detections of H2O are not available; and (2) as an observational constraint to models predicting the rotational distribution of rovibrationally excited OH produced by water photolysis. C1 NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. Univ Toledo, Dept Phys & Astron, Ritter Astrophys Res Ctr, Toledo, OH 43606 USA. Johns Hopkins Univ, Appl Phys Lab, Space Dept, Planetary Explorat Grp, Laurel, MD 20723 USA. Rowan Coll, Dept Phys & Astron, Glassboro, NJ 08028 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. RP Bonev, BP (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. EM bbonev@ssedmail.gsfc.nasa.gov RI mumma, michael/I-2764-2013; Magee-Sauer, Karen/K-6061-2015; Dello Russo, Neil/G-2727-2015 OI Magee-Sauer, Karen/0000-0002-4979-9875; Dello Russo, Neil/0000-0002-8379-7304 NR 52 TC 41 Z9 41 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP 774 EP 787 DI 10.1086/508452 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AG UT WOS:000242913800067 ER PT J AU Bonev, BP Mumma, MJ AF Bonev, Boncho P. Mumma, Michael J. TI A comprehensive study of infrared OH prompt emission in two comets. II. Implications for unimolecular dissociation of H2O SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; comets : individual (C/2000 WM1 [LINEAR], C/2004 Q2 [Machholz]); molecular data ID 1ST ABSORPTION-BAND; C/1999 H1 LEE; WATER PRODUCTION; LAMBDA-DOUBLET; PHOTODISSOCIATION; DYNAMICS; PHOTOFRAGMENTATION; C/2001-A2; MULTIPLET; NUCLEAR AB Infrared emission from hydroxyl has been observed in several comets via high-resolution infrared spectroscopy. The principal excitation mechanism for this emission is single-step photolysis of H2O, terminating in OH fragments that are both vibrationally and rotationally excited. Recently reported comet data provide quantitative measures of the rotational distribution of OH* [X-2 Pi; v' = 1] for J' < 17.5. The measured distributions of relative g-factors for OH "prompt" emission, and especially the ratios of the Pi(A") and Pi(A') Lambda-doubling components, are remarkably similar for comets C/2000 WM1 (LINEAR) and C/2004 Q2 (Machholz). We discuss how these results complement ab initio theoretical studies of water dissociation and those done in terrestrial laboratories. C1 NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP Bonev, BP (reprint author), Catholic Univ Amer, Washington, DC 20064 USA. EM bbonev@ssedmail.gsfc.nasa.gov RI mumma, michael/I-2764-2013 NR 29 TC 17 Z9 17 U1 0 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP 788 EP 791 DI 10.1086/508450 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AG UT WOS:000242913800068 ER PT J AU Georganopoulos, M Perlman, ES Kazanas, D McEnery, J AF Georganopoulos, Markos Perlman, Eric S. Kazanas, Demosthenes McEnery, Julie TI Quasar X-ray jets: Gamma-ray diagnostics of the synchrotron and inverse Compton hypotheses: The case of 3C 273 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : general; quasars : individual (3C 273); radiation mechanisms : nonthermal; X-rays : galaxies ID LARGE-SCALE JETS; ACTIVE GALACTIC NUCLEI; RADIO JETS; 3C 273; CHANDRA OBSERVATIONS; EXTRAGALACTIC JETS; SPACE-TELESCOPE; EMISSION; SPECTRA; BLAZARS AB The process responsible for the Chandra-detected X-ray emission from the large-scale jets of powerful quasars is a matter of ongoing debate. The two main contenders are external Compton scattering off the cosmic microwave background photons (EC/CMB) and synchrotron emission from a population of electrons separate from those producing the radio-IR emission. So far, no clear diagnostics have been presented to distinguish which of the two, if any, is the actual X-ray emission mechanism. Here we present such diagnostics based on a fundamental difference between these two models: the production of synchrotron X-rays requires multi-TeV electrons, while the EC/CMB model requires a cutoff in the electron energy distribution below TeV energies. This has significant implications for the gamma-ray emission predicted by these two models, which can be tested through GeV and TeV observations of the nearby bright quasar 3C 273. We show how existing and future GeV and TeV observations can confirm or refute one or both of the above hypotheses. C1 Univ Maryland, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Georganopoulos, M (reprint author), Univ Maryland, Dept Phys, Joint Ctr Astrophys, 1000 Hilltop Circle, Baltimore, MD 21250 USA. RI McEnery, Julie/D-6612-2012; OI Perlman, Eric/0000-0002-3099-1664 NR 35 TC 23 Z9 23 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP L5 EP L8 DI 10.1086/510452 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AI UT WOS:000242914000002 ER PT J AU Gezari, S Martin, DC Milliard, B Basa, S Halpern, JP Forster, K Friedman, PG Morrissey, P Neff, SG Schiminovich, D Seibert, M Small, T Wyder, TK AF Gezari, S. Martin, D. C. Milliard, B. Basa, S. Halpern, J. P. Forster, K. Friedman, P. G. Morrissey, P. Neff, S. G. Schiminovich, D. Seibert, M. Small, T. Wyder, T. K. TI Ultraviolet detection of the tidal disruption of a star by a supermassive black hole SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : nuclei; ultraviolet : galaxies ID ACTIVE GALACTIC NUCLEI; X-RAY; GALAXIES; EMISSION; SPECTRUM; CHANDRA; EVENTS; FLARE; RATES AB A supermassive black hole in the nucleus of a galaxy will be revealed when a star passes close enough to be torn apart by tidal forces and a flare of radiation is emitted by the stream of stellar debris that plunges into the black hole. Since common active galactic nuclei have accreting black holes that can also produce flares, a convincing demonstration that a stellar tidal disruption has occurred generally begins with a "normal" galaxy that has no evidence of prior nuclear activity. Here we,report a luminous UV flare from an elliptical galaxy at z=0.37 in the Groth field of the GALEX Deep Imaging Survey that has no evidence of a Seyfert nucleus from optical spectroscopy and X-ray imaging obtained during the flare. Multiwavelength data collected at the time of the event, and for 2 years following, allow us to constrain, for the first time, the spectral energy distribution of a candidate tidal disruption flare from optical through X-rays. The luminosity and temperature of the radiation and the decay curve of the flare are in excellent agreement with theoretical predictions for the tidal disruption of a star, and provide the strongest empirical evidence for a stellar disruption event to date. C1 CALTECH, Pasadena, CA 91125 USA. Astrophys Lab, F-13376 Marseille 12, France. Columbia Univ, Dept Astron, New York, NY 10027 USA. NASA, Goddard Space Flight Ctr, Lab Astron & Solar Phys, Greenbelt, MD 20771 USA. RP Gezari, S (reprint author), CALTECH, MC 405-47,1200 E Calif Blvd, Pasadena, CA 91125 USA. EM suvi@srl.caltech.edu NR 30 TC 88 Z9 88 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP L25 EP L28 DI 10.1086/509918 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AI UT WOS:000242914000007 ER PT J AU Stothers, RB AF Stothers, Richard B. TI A virial theorem investigation of magnetic variations in the Sun SO ASTROPHYSICAL JOURNAL LA English DT Article DE magnetic fields; Sun : interior ID SOLAR-CYCLE DEPENDENCE; APPARENT RADIUS; DISK SEXTANT; DIAMETER; LUMINOSITY; VARIABILITY; FIELDS; TEMPERATURE; CONSTANCY; OBLATENESS AB The magnetic virial theorem is applied here to a long-standing astrophysical problem, namely, the sign of the Sun's radius change during the solar activity cycle. The solar radius is theoretically found to decrease around the time of maximum magnetic field strength, in agreement with the best available observational evidence. This theoretical prediction, although simply based, instills some confidence by explicitly satisfying the conservation of total energy. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Stothers, RB (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. NR 47 TC 8 Z9 8 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2006 VL 653 IS 1 BP L73 EP L75 DI 10.1086/510406 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 118AI UT WOS:000242914000019 ER PT J AU Taylor, M Peltzer, G AF Taylor, Michael Peltzer, Gilles TI Current slip rates on conjugate strike-slip faults in central Tibet using synthetic aperture radar interferometry SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ALTYN-TAGH FAULT; SOUTHERN TIBET; CRUSTAL DEFORMATION; TECTONIC EVOLUTION; ACTIVE TECTONICS; METAMORPHIC BELT; GPS MEASUREMENTS; PLANE SOLUTIONS; SHEAR ZONE; PLATEAU AB [ 1] We estimate the current slip rates on active conjugate strike-slip faults in central Tibet using repeat-pass synthetic aperture radar interferometry (InSAR). The conjugate fault systems are centered along the east trending Late Jurassic - Early Cretaceous Bangong-Nujiang suture zone and are composed of NE striking left-slip faults to the north and NW striking right-slip faults to the south. The surface displacement field obtained from InSAR data show 30- to 60-km-wide zones of concentrated shear that coincide with active fault traces observed in the field. The radar data indicate that, within a 200- to 300-km-wide belt, the deformation regime defined by the conjugate strike-slip faults is accommodating similar to 5 mm yr(-1) of pure shear contraction oriented in the N10 degrees E direction and similar to 6 mm yr(-1) of right-lateral simple shear in the N110 degrees E direction. The observation of localized strain along faults indicates that faulting is the dominant mode of deformation in central Tibet with seismogenic depths extending down to similar to 25 km. Furthermore, extrapolating the current slip rates estimated for the central Tibet faults, the total magnitude of fault slip based on geological observations would only require the faults to have initiated sometime in the past 2 - 3 Myr. This appears to contradict the few geochronologic constraints on fault initiation at 8 Ma or even earlier. This discrepancy suggests that the fault slip rates may not have remained constant through time but have accelerated in the recent period. With the exception of the slip rate on the Gyaring Co fault, the slip rates that we determined on the conjugate strike-slip faults in central Tibet are significantly slower than the rates on faults that bound the Tibetan Plateau, such as the left-slip Altyn Tagh fault to the north. This observation suggests that although deformation is active within central Tibet, plateau-bounding structures are dominant in absorbing Indo-Asian convergence. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. RP Taylor, M (reprint author), Univ Kansas, Dept Geol, 1475 Jayhawk Blvd,120 Lindley Hall, Lawrence, KS 66045 USA. EM mht@ku.edu RI Taylor, Michael/D-9939-2011 NR 52 TC 36 Z9 36 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 9 PY 2006 VL 111 IS B12 AR B12402 DI 10.1029/2005JB004014 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 115TT UT WOS:000242757400002 ER PT J AU Rex, M Salawitch, RJ Deckelmann, H von der Gathen, P Harris, NRP Chipperfield, MP Naujokat, B Reimer, E Allaart, M Andersen, SB Bevilacqua, R Braathen, GO Claude, H Davies, J De Backer, H Dier, H Dorokhov, V Fast, H Gerding, M Godin-Beekmann, S Hoppel, K Johnson, B Kyro, E Litynska, Z Moore, D Nakane, H Parrondo, MC Risley, AD Skrivankova, P Stubi, R Viatte, P Yushkov, V Zerefos, C AF Rex, M. Salawitch, R. J. Deckelmann, H. von der Gathen, P. Harris, N. R. P. Chipperfield, M. P. Naujokat, B. Reimer, E. Allaart, M. Andersen, S. B. Bevilacqua, R. Braathen, G. O. Claude, H. Davies, J. De Backer, H. Dier, H. Dorokhov, V. Fast, H. Gerding, M. Godin-Beekmann, S. Hoppel, K. Johnson, B. Kyroe, E. Litynska, Z. Moore, D. Nakane, H. Parrondo, M. C. Risley, A. D., Jr. Skrivankova, P. Stuebi, R. Viatte, P. Yushkov, V. Zerefos, C. TI Arctic winter 2005: Implications for stratospheric ozone loss and climate change SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DEPLETION AB [1] The Arctic polar vortex exhibited widespread regions of low temperatures during the winter of 2005, resulting in significant ozone depletion by chlorine and bromine species. We show that chemical loss of column ozone (Delta O(3)) and the volume of Arctic vortex air cold enough to support the existence of polar stratospheric clouds (V(PSC)) both exceed levels found for any other Arctic winter during the past 40 years. Cold conditions and ozone loss in the lowermost Arctic stratosphere (e.g., between potential temperatures of 360 to 400 K) were particularly unusual compared to previous years. Measurements indicate Delta O(3) = 121 +/- 20 DU and that Delta O(3) versus V(PSC) lies along an extension of the compact, near linear relation observed for previous Arctic winters. The maximum value of V(PSC) during five to ten year intervals exhibits a steady, monotonic increase over the past four decades, indicating that the coldest Arctic winters have become significantly colder, and hence are more conducive to ozone depletion by anthropogenic halogens. C1 Alfred Wegener Inst Polar & Marine Res, Res Unit Potsdam, D-14401 Potsdam, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Cambridge, European Ozone Res Coordinating Unit, Cambridge CB2 1EW, England. Univ Leeds, Sch Earth & Environm, Leeds LS2 9JT, W Yorkshire, England. Free Univ Berlin, Inst Meteorol, D-12165 Berlin, Germany. Royal Netherlands Meteorol Inst, NL-3730 AE De Bilt, Netherlands. Danish Meteorol Inst, DK-20100 Copenhagen, Denmark. USN, Res Lab, Washington, DC 20375 USA. Norwegian Inst Air Res, Kjeller, Norway. German Weather Serv, Meteorol Observ Hohenpeissenberg, D-82383 Hohenpeissenberg, Germany. Meteorol Serv Canada, Toronto, ON M3H 5T4, Canada. Royal Meteorol Inst Belgium, B-01180 Brussels, Belgium. Meteorol Observ Lindenberg, Lindenberg, Germany. Cent Aerol Observ, Moscow, Russia. Leibniz Inst Atmospharenphys, D-18225 Kuhlungsborn, Germany. CNRS, Inst Pierre Simon Laplace, Serv Aeron, F-75252 Paris 05, France. NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA. Sodankyla Meteorol Observ, Sodankyla, Finland. Ctr Aerol, Inst Meteorol & Water Management, PL-05119 Legionowo, Poland. Met Off, Exeter EX1 3PB, Devon, England. Natl Inst Environm Studies, Asian Environm Res Grp, Tsukuba, Ibaraki 3058506, Japan. Inst Nacl Tecn Aerospacial, E-28850 Madrid, Spain. Sci Applicat Int Corp, Hampton, VA 23666 USA. Czech Hydrometeorol Inst, Prague 14306 4, Czech Republic. Swiss Meteorol Aerol Stn, CH-1530 Payerne, Switzerland. MeteoSwiss, Fed Off Meteorol & Climatol, CH-1530 Payerne, Switzerland. Univ Athens, Lab Climatol & Atmospher Environm, GR-15784 Athens, Greece. RP Rex, M (reprint author), Alfred Wegener Inst Polar & Marine Res, Res Unit Potsdam, POB 600149, D-14401 Potsdam, Germany. EM mrex@awi-potsdam.de RI andersen, signe/C-4809-2013; Chipperfield, Martyn/H-6359-2013; Rex, Markus/A-6054-2009; Salawitch, Ross/B-4605-2009; von der Gathen, Peter/B-8515-2009; OI andersen, signe/0000-0002-8216-0141; Chipperfield, Martyn/0000-0002-6803-4149; Rex, Markus/0000-0001-7847-8221; Salawitch, Ross/0000-0001-8597-5832; von der Gathen, Peter/0000-0001-7409-1556; Nakane, Hideaki/0000-0002-9032-6105; Harris, Neil/0000-0003-1256-3006 NR 13 TC 98 Z9 99 U1 0 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 8 PY 2006 VL 33 IS 23 AR L23808 DI 10.1029/2006GL026731 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 115RW UT WOS:000242752500001 ER PT J AU Golombek, MP Grant, JA Crumpler, LS Greeley, R Arvidson, RE Bell, JF Weitz, CM Sullivan, R Christensen, PR Soderblom, LA Squyres, SW AF Golombek, M. P. Grant, J. A. Crumpler, L. S. Greeley, R. Arvidson, R. E. Bell, J. F., III Weitz, C. M. Sullivan, R. Christensen, P. R. Soderblom, L. A. Squyres, S. W. TI Erosion rates at the Mars Exploration Rover landing sites and long-term climate change on Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MINI-TES EXPERIMENT; MERIDIANI-PLANUM; GUSEV CRATER; SPIRIT ROVER; OPPORTUNITY ROVER; MARTIAN HIGHLANDS; ATMOSPHERIC DUST; IMPACT CRATERS; MAADIM-VALLIS; EVOLUTION AB [1] Erosion rates derived from the Gusev cratered plains and the erosion of weak sulfates by saltating sand at Meridiani Planum are so slow that they argue that the present dry and desiccating environment has persisted since the Early Hesperian. In contrast, sedimentary rocks at Meridiani formed in the presence of groundwater and occasional surface water, and many Columbia Hills rocks at Gusev underwent aqueous alteration during the Late Noachian, approximately coeval with a wide variety of geomorphic indicators that indicate a wetter and likely warmer environment. Two-toned rocks, elevated ventifacts, and perched and undercut rocks indicate localized deflation of the Gusev plains and deposition of an equivalent amount of sediment into craters to form hollows, suggesting average erosion rates of similar to 0.03 nm/yr. Erosion of Hesperian craters, modification of Late Amazonian craters, and the concentration of hematite concretions in the soils of Meridiani yield slightly higher average erosion rates of 1-10 nm/yr in the Amazonian. These erosion rates are 2-5 orders of magnitude lower than the slowest continental denudation rates on Earth, indicating that liquid water was not an active erosional agent. Erosion rates for Meridiani just before deposition of the sulfate-rich sediments and other eroded Noachian areas are comparable with slow denudation rates on Earth that are dominated by liquid water. Available data suggest the climate change at the landing sites from wet and likely warm to dry and desiccating occurred sometime between the Late Noachian and the beginning of the Late Hesperian (3.7-3.5 Ga). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. New Mexico Museum Nat hist & Sci, Albuquerque, NM 87104 USA. Smithsonian Inst, Ctr Earth & Planetary Studies, Natl Air & Space Museum, Washington, DC 20560 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Planetary Sci Inst, Tucson, AZ 85719 USA. RP Golombek, MP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mgolombek@jpl.nasa.gov NR 90 TC 93 Z9 93 U1 2 U2 28 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 8 PY 2006 VL 111 IS E12 AR E12S10 DI 10.1029/2006JE002754 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 115TI UT WOS:000242756300004 ER PT J AU Temma, T Baines, KH Butler, RAH Brown, LR Sagui, L Kleiner, I AF Temma, T. Baines, K. H. Butler, R. A. H. Brown, L. R. Sagui, L. Kleiner, I. TI Exponential sum absorption coefficients of phosphine from 2750 to 3550 cm(-1) for application to radiative transfer analyses on Jupiter and Saturn SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID NORTH EQUATORIAL BELT; MOLECULAR SPECTROSCOPIC DATABASE; TROPOSPHERIC GAS-COMPOSITION; D/H ISOTOPIC RATIO; CLOUD STRUCTURE; MU-M; ATMOSPHERIC COMPOSITION; PLANETARY MEASUREMENTS; VERTICAL STRUCTURE; LOW-TEMPERATURE AB [1] PH3 exponential sum k coefficients were computed between 2750 and 3550 cm(-1) (2.82-3.64 mu m), in view of future application to radiative transfer analyses of Jupiter and Saturn in a phosphine absorption band near 3 mu m. The temperature and pressure of this data set cover the ranges from 80 to 350 K and from 10(-3) to 10(1) bars, respectively. Transmission uncertainty incurred by the use of the k coefficients is smaller than a few percent as long as the radiation is confined above an altitude of a few bars in the giant planets. In spectral regions of weak absorption at high pressures close to 10 bars, contributions from far wings of strong absorption lines must be carefully taken into account. Our data set helps map the three-dimensional distribution of PH3 on the giant planets, revealing their global atmospheric dynamics extending down to the deep interior. The complete k coefficient data set of this work is available at the Web site of the NASA Planetary Data System Atmospheres Node. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Paris 07, Lab Interuniv Syst Atmospher, CNRS, F-94010 Creteil, France. Univ Paris 12, Lab Interuniv Syst Atmospher, CNRS, F-94010 Creteil, France. Pittsburg State Univ, Pittsburg, KS 66762 USA. RP Temma, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ttemma@scn.jpl.nasa.gov NR 55 TC 3 Z9 3 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 8 PY 2006 VL 111 IS E12 AR E12003 DI 10.1029/2006JE002720 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 115TI UT WOS:000242756300001 ER PT J AU Wahr, JM Zuber, MT Smith, DE Lunine, JI AF Wahr, J. M. Zuber, M. T. Smith, D. E. Lunine, J. I. TI Tides on Europa, and the thickness of Europa's icy shell SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MARS GLOBAL SURVEYOR; ORBITER LASER ALTIMETER; GRAVITY-FIELD; GALILEAN SATELLITES; TIDAL FLEXURE; OCEAN; MODEL; EARTH; CONSTRAINTS; MARGINS AB [1] It has been shown previously that measurements of tides on Jupiter's moon Europa can be used to determine whether there is a liquid ocean beneath this moon's icy outer shell. In this paper we examine the further possibility of constraining the thickness of the icy shell in the case where a liquid ocean exists, by combining measurements of tidal gravity obtained from tracking an orbiting spacecraft with measurements of vertical tidal surface displacements obtained from a precise onboard altimeter. By simulating a 1-month Europa mapping mission we demonstrate that this combination of tidal measurements would provide a much better estimate of ice thickness than could be obtained using either tracking or altimeter measurements alone. The thickness value inferred from the combined data would also require an estimate of the shear modulus of Europa's icy shell. This introduces an additional uncertainty in the thickness estimate that is approximately proportional to the uncertainty in the inverse of the shear modulus. C1 Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Ist Fis Spazio Interplanetario, I-00133 Rome, Italy. NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RP Wahr, JM (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. EM wahr@lemond.colorado.edu; mtz@mit.edu; david.e.smith@nasa.gov; jlunine@lpl.arizona.edu NR 45 TC 27 Z9 27 U1 4 U2 26 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 8 PY 2006 VL 111 IS E12 AR E12005 DI 10.1029/2006JE002729 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 115TI UT WOS:000242756300002 ER PT J AU Holliday, JR Rundle, JB Turcotte, DL Klein, W Tiampo, KF Donnellan, A AF Holliday, James R. Rundle, John B. Turcotte, Donald L. Klein, William Tiampo, Kristy F. Donnellan, Andrea TI Space-time clustering and correlations of major earthquakes SO PHYSICAL REVIEW LETTERS LA English DT Article ID MODELS; DYNAMICS; FAULTS; SEISMICITY; STATISTICS AB Earthquake occurrence in nature is thought to result from correlated elastic stresses, leading to clustering in space and time. We show that the occurrence of major earthquakes in California correlates with time intervals when fluctuations in small earthquakes are suppressed relative to the long term average. We estimate a probability of less than 1% that this coincidence is due to random clustering. C1 Univ Calif Davis, Ctr Computat Sci & Engn, Davis, CA 95616 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Davis, Dept Geol, Davis, CA 95616 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Univ Western Ontario, Dept Earth Sci, London, ON N6A 5B8, Canada. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. RP Holliday, JR (reprint author), Univ Calif Davis, Ctr Computat Sci & Engn, Davis, CA 95616 USA. EM holliday@cse.ucdavis.edu; jbrundle@ucdavis.edu; turcotte@geology.ucdavis.edu; klein@physics.bu.edu; ktiampo@seis.es.uwo.ca; andrea.donnellan@jpl.nasa.gov RI Tiampo, Kristy/I-1355-2015 OI Tiampo, Kristy/0000-0002-5500-7600 NR 20 TC 38 Z9 38 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 8 PY 2006 VL 97 IS 23 AR 238501 DI 10.1103/PhysRevLett.97.238501 PG 4 WC Physics, Multidisciplinary SC Physics GA 115BG UT WOS:000242708900073 PM 17280253 ER PT J AU Jordan, PM Straughan, B AF Jordan, P. M. Straughan, B. TI Acoustic acceleration waves in homentropic Green and Naghdi gases SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE acceleration waves; Green and Naghdi gases; nonlinear acoustics; temperature rate waves ID SONIC DISCONTINUITIES; GROWTH; DECAY; FLUID; MEDIA AB Acceleration and temperature rate waves in lossless Green and Naghdi gases are investigated. The exact equations of motion are also derived and then simplified under the finite-amplitude approximation. Bounds are established for the theory-specific coupling parameter, as well as several other quantities, and results are compared/contrasted with those for classical perfect gases. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Univ Durham, Dept Math Sci, Durham DH1 3LE, England. RP Jordan, PM (reprint author), USN, Res Lab, Stennis Space Ctr, Code 7181, Stennis Space Ctr, MS 39529 USA. EM pjordan@nrlssc.navy.mil NR 31 TC 16 Z9 16 U1 1 U2 1 PU ROYAL SOCIETY PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 J9 P R SOC A JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD DEC 8 PY 2006 VL 462 IS 2076 BP 3601 EP 3611 DI 10.1098/rspa.2006.1739 PG 11 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 114RY UT WOS:000242684500006 ER PT J AU Buchman, LT Sarbach, OCA AF Buchman, Luisa T. Sarbach, Olivier C. A. TI Towards absorbing outer boundaries in general relativity SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID EINSTEINS FIELD-EQUATIONS; DOMAIN WAVE-PROPAGATION; REST-MASS FIELDS; GRAVITATIONAL-RADIATION; NUMERICAL RELATIVITY; NONSPHERICAL PERTURBATIONS; RAPID EVALUATION; BLACK-HOLES; SIMULATION; STABILITY AB We construct exact solutions to the Bianchi equations on a flat spacetime background. When the constraints are satisfied, these solutions represent in- and outgoing linearized gravitational radiation. We then consider the Bianchi equations on a subset of flat spacetime of the form [ 0, T] x BR, where BR is a ball of radius R, and analyse different kinds of boundary conditions on aBR. Our main results are as follows. (i) We give an explicit analytic example showing that boundary conditions obtained from freezing the incoming characteristic fields to their initial values are not compatible with the constraints. (ii) With the help of the exact solutions constructed, we determine the amount of artificial reflection of gravitational radiation from constraint-preserving boundary conditions which freeze the Weyl scalar psi(0) to its initial value. For monochromatic radiation with wave number k and arbitrary angular momentum number l >= 2, the amount of reflection decays as (kR)(-4) for large kR. (iii) For each L >= 2, we construct new local constraint-preserving boundary conditions which perfectly absorb linearized radiation with l <= L. (iv) We generalize our analysis to a weakly curved background of mass M and compute first-order corrections in M/R to the reflection coefficients for quadrupolar odd-parity radiation. For our new boundary condition with L=2, the reflection coefficient is smaller than that for the freezing psi(0) boundary condition by a factor of M/R for kR > 1.04. Implications of these results for numerical simulations of binary black holes on finite domains are discussed. C1 Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, Dept Math, La Jolla, CA 92093 USA. Univ Michoacana, Inst Fis & Matemat, Morelia, Michoacan, Mexico. RP Buchman, LT (reprint author), Jet Prop Lab, Relativist Astrophys 169-327,4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Sarbach, Olivier/0000-0002-0753-4449 NR 79 TC 39 Z9 39 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD DEC 7 PY 2006 VL 23 IS 23 BP 6709 EP 6744 DI 10.1088/0264-9381/23/23/007 PG 36 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 108DQ UT WOS:000242220900008 ER PT J AU Behrenfeld, MJ O'Malley, RT Siegel, DA McClain, CR Sarmiento, JL Feldman, GC Milligan, AJ Falkowski, PG Letelier, RM Boss, ES AF Behrenfeld, Michael J. O'Malley, Robert T. Siegel, David A. McClain, Charles R. Sarmiento, Jorge L. Feldman, Gene C. Milligan, Allen J. Falkowski, Paul G. Letelier, Ricardo M. Boss, Emmanuel S. TI Climate-driven trends in contemporary ocean productivity SO NATURE LA English DT Article ID EL-NINO; EQUATORIAL PACIFIC; EXPORT PRODUCTION; WORLDS OCEANS; PERIOD AB Contributing roughly half of the biosphere's net primary production (NPP)(1,2), photosynthesis by oceanic phytoplankton is a vital link in the cycling of carbon between living and inorganic stocks. Each day, more than a hundred million tons of carbon in the form of CO(2) are fixed into organic material by these ubiquitous, microscopic plants of the upper ocean, and each day a similar amount of organic carbon is transferred into marine ecosystems by sinking and grazing. The distribution of phytoplankton biomass and NPP is defined by the availability of light and nutrients ( nitrogen, phosphate, iron). These growth-limiting factors are in turn regulated by physical processes of ocean circulation, mixed-layer dynamics, upwelling, atmospheric dust deposition, and the solar cycle. Satellite measurements of ocean colour provide a means of quantifying ocean productivity on a global scale and linking its variability to environmental factors. Here we describe global ocean NPP changes detected from space over the past decade. The period is dominated by an initial increase in NPP of 1,930 teragrams of carbon a year (Tg C yr(-1)), followed by a prolonged decrease averaging 190 Tg C yr(-1). These trends are driven by changes occurring in the expansive stratified low-latitude oceans and are tightly coupled to coincident climate variability. This link between the physical environment and ocean biology functions through changes in upper-ocean temperature and stratification, which influence the availability of nutrients for phytoplankton growth. The observed reductions in ocean productivity during the recent post-1999 warming period provide insight on how future climate change can alter marine food webs. C1 Oregon State Univ, Dept Bot & Plant Pathol, Corvallis, OR 97331 USA. Oregon State Univ, Coll Oceanog & Atmospher Sci, Corvallis, OR 97331 USA. Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. Rutgers State Univ, Dept Geol Sci, New Brunswick, NJ 08901 USA. Rutgers State Univ, Inst Marine & Coastal Sci, Environm Biophys & Mol Ecol Program, New Brunswick, NJ 08901 USA. Univ Maine, Sch Marine Sci, Orono, ME 04469 USA. RP Behrenfeld, MJ (reprint author), Oregon State Univ, Dept Bot & Plant Pathol, 2082 Cordley Hall, Corvallis, OR 97331 USA. EM mjb@science.oregonstate.edu RI Letelier, Ricardo/A-6953-2009; Boss, Emmanuel/C-5765-2009; Siegel, David/C-5587-2008; Smith, Christa/G-3187-2010 OI Letelier, Ricardo/0000-0003-3376-4026; Boss, Emmanuel/0000-0002-8334-9595; NR 26 TC 829 Z9 862 U1 97 U2 592 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 7 PY 2006 VL 444 IS 7120 BP 752 EP 755 DI 10.1038/nature05317 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 113EL UT WOS:000242581100059 PM 17151666 ER PT J AU Bosch, H Toon, GC Sen, B Washenfelder, RA Wennberg, PO Buchwitz, M de Beek, R Burrows, JP Crisp, D Christi, M Connor, BJ Natraj, V Yung, YL AF Boesch, H. Toon, G. C. Sen, B. Washenfelder, R. A. Wennberg, P. O. Buchwitz, M. de Beek, R. Burrows, J. P. Crisp, D. Christi, M. Connor, B. J. Natraj, V. Yung, Y. L. TI Space-based near-infrared CO2 measurements: Testing the Orbiting Carbon Observatory retrieval algorithm and validation concept using SCIAMACHY observations over Park Falls, Wisconsin SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOLAR ABSORPTION-SPECTRA; TOTAL COLUMN AMOUNTS; O-2 A-BAND; ATMOSPHERIC CO2; REFLECTED SUNLIGHT; WFM-DOAS; TRANSPORT MODELS; ONBOARD ENVISAT; DIOXIDE FLUXES; SATELLITE DATA AB Space-based measurements of reflected sunlight in the near-infrared (NIR) region promise to yield accurate and precise observations of the global distribution of atmospheric CO2. The Orbiting Carbon Observatory (OCO) is a future NASA mission, which will use this technique to measure the column-averaged dry air mole fraction of CO2 (X-CO2) with the precision and accuracy needed to quantify CO2 sources and sinks on regional scales (similar to 1000 x 1000 km(2)) and to characterize their variability on seasonal timescales. Here, we have used the OCO retrieval algorithm to retrieve X-CO2 and surface pressure from space-based Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) measurements and from coincident ground-based Fourier transform spectrometer (FTS) measurements of the O-2 A band at 0.76 mu m and the 1.58 mu m CO2 band for Park Falls, Wisconsin. Even after accounting for a systematic error in our representation of the O-2 absorption cross sections, we still obtained a positive bias between SCIAMACHY and FTS X-CO2 retrievals of similar to 3.5%. Additionally, the retrieved surface pressures from SCIAMACHY systematically underestimate measurements of a calibrated pressure sensor at the FTS site. These findings lead us to speculate about inadequacies in the forward model of our retrieval algorithm. By assuming a 1% intensity offset in the O-2 A band region for the SCIAMACHY X-CO2 retrieval, we significantly improved the spectral fit and achieved better consistency between SCIAMACHY and FTS X-CO2 retrievals. We compared the seasonal cycle of X-CO2 at Park Falls from SCIAMACHY and FTS retrievals with calculations of the Model of Atmospheric Transport and Chemistry/Carnegie-Ames-Stanford Approach (MATCH/CASA) and found a good qualitative agreement but with MATCH/CASA underestimating the measured seasonal amplitude. Furthermore, since SCIAMACHY observations are similar in viewing geometry and spectral range to those of OCO, this study represents an important test of the OCO retrieval algorithm and validation concept using NIR spectra measured from space. Finally, we argue that significant improvements in precision and accuracy could be obtained from a dedicated CO2 instrument such as OCO, which has much higher spectral and spatial resolutions than SCIAMACHY. These measurements would then provide critical data for improving our understanding of the carbon cycle and carbon sources and sinks. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Bremen, Inst Environm Phys, D-28359 Bremen, Germany. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Natl Inst Water & Atmospher Res, Lauder 9182, Otago, New Zealand. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Bosch, H (reprint author), CALTECH, Jet Prop Lab, MS 183-601,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM hartmut.boesch@jpl.nasa.gov RI Buchwitz, Michael/G-1510-2011; Washenfelder, Rebecca/E-7169-2010; Wennberg, Paul/A-5460-2012; Boesch, Hartmut/G-6021-2012; Burrows, John/B-6199-2014 OI Washenfelder, Rebecca/0000-0002-8106-3702; Burrows, John/0000-0002-6821-5580 NR 66 TC 72 Z9 73 U1 3 U2 18 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 6 PY 2006 VL 111 IS D23 AR D23302 DI 10.1029/2006JD007080 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 115SG UT WOS:000242753500003 ER PT J AU Duru, F Gurnett, DA Averkamp, TF Kirchner, DL Huff, RL Persoon, AM Plaut, JJ Picardi, G AF Duru, F. Gurnett, D. A. Averkamp, T. F. Kirchner, D. L. Huff, R. L. Persoon, A. M. Plaut, J. J. Picardi, G. TI Magnetically controlled structures in the ionosphere of Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND INTERACTION; GLOBAL SURVEYOR; ELECTRON REFLECTOMETER; CRUSTAL MAGNETIZATION; RADAR SOUNDINGS; RADIO SCIENCE; FIELD AB The ionospheric sounding data obtained by the MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding) instrument on the Mars Express spacecraft show that the dayside ionosphere has considerable structure over regions of strong crustal magnetic fields. This structure is typically seen as a hyperbola-shaped trace in a display of echo intensity versus apparent altitude and time. The hyperbola shapes are consistent with oblique reflections from regions of enhanced electron density that are fixed with respect to Mars. Comparisons with the Cain et al. (2003) model for the crustal magnetic field of Mars show that the apexes of the hyperbolas, which identify the closest approach to the regions of enhanced electron density, usually coincide with regions where the crustal magnetic field is strong and nearly vertical. The electron density enhancements, which extend as much as 50 km above the surrounding ionosphere, are believed to arise from increases in the scale height of the ionosphere, possibly due to heating of the ionosphere by solar wind electrons that reach the base of the ionosphere along the nearly vertical ( open) magnetic field lines. Statistical analyses of the apparent altitudes of the apexes of the hyperbolas, as well as analyses of repeated passes over the same region, indicate that the electron density enhancements usually consist of horizontal cylinder-like structures rather than isolated hemispherical structures. In many cases the axes of the cylindrical density structures are aligned with the symmetry axes of adjacent cylindrical magnetic field structures with opposite polarity. C1 Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Univ Roma La Sapienza, Infocom Dept, I-00184 Rome, Italy. Jet Prop Lab, Pasadena, CA 91109 USA. RP Duru, F (reprint author), Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. EM firdevs-duru@uiowa.edu NR 17 TC 43 Z9 44 U1 4 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 6 PY 2006 VL 111 IS A12 AR A12204 DI 10.1029/2006JA011975 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 115TU UT WOS:000242757500002 ER PT J AU Sun, XH Yu, B Ng, G Nguyen, TD Meyyappan, M AF Sun, Xuhui Yu, Bin Ng, Garrick Nguyen, Thuc Dinh Meyyappan, M. TI III-VI compound semiconductor indium selenide (In2Se3) nanowires: Synthesis and characterization SO APPLIED PHYSICS LETTERS LA English DT Article ID PHASE-CHANGE MEMORY; THIN-FILMS; NANOTUBES; MECHANISM; BEHAVIOR; GROWTH AB The authors report the synthesis of one-dimensional indium selenide nanowire, a III-VI group compound semiconductor nanostructure with potential applications in data storage, solar cells, and optoelectronics. Nanoscale gold particles were used as catalysts and growth was also demonstrated using indium as self-catalyst. The growth mechanism is confirmed to be vapor-liquid-solid process by in situ heating experiments in which In and Se were found to diffuse back into the gold catalyst bead forming a Au-In-Se alloy that was molten at elevated temperatures. The morphology, composition, and crystal structure of the In2Se3 nanowires (NWs) were analyzed by scanning electron microscopy, energy dispersive x-ray spectroscopy, and high-resolution transmission electron microscopy. (c) 2006 American Institute of Physics. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Yu, B (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM byu@mail.arc.nasa.gov RI Sun, Xuhui /K-5689-2012 NR 17 TC 59 Z9 59 U1 3 U2 41 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 4 PY 2006 VL 89 IS 23 AR 233121 DI 10.1063/1.2388890 PG 3 WC Physics, Applied SC Physics GA 115BJ UT WOS:000242709200112 ER PT J AU Chen, CH Huang, MQ Foster, JE Monnette, G Middleton, J Higgins, A Liu, S AF Chen, C. H. Huang, M. Q. Foster, John E. Monnette, G. Middleton, J. Higgins, A. Liu, S. TI Effect of surface modification on mechanical properties and thermal stability of Sm-Co high temperature magnetic materials SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE high temperature rare earth magnets; surface modification; Ni plating from sulfamate electrolyte; fracture toughness; thermal stability; adhesive bond strength AB The effects of different surface modifications on the mechanical properties and thermal stability of Sm-Co high temperature magnets are reported in this paper. The fracture toughness was increased by 76% for the specimens modified with the Ni plating from sulfamate electrolyte. Compared to the uncoated magnets, the thermal stability of the modified magnets was improved by 143% in high vacuum condition for aging at 500 degrees C up to 3000 h and by 761% in air for aging at 500 degrees C up to 2700 h. Microstructures of the specimens with and without surface modifications were studied using scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS), showing different fracture patterns. The improvements in mechanical properties were made by closing the infinite crack-origin sites on the surface of the magnets with ductile metal. The striking improvement in thermal stability was achieved by sealing the magnet body with corrosion resistive metal to limit oxidation. The adhesive bond strength between the magnet and the modified surface plays an important role in these improvements. The nickel plating from sulfamate electrolyte provides epitaxial growth of Ni from the surface of the Sm-Co magnet, which results in a stronger bond strength in between the Ni and the base material than that of the Sm-Co base material itself. Improved mechanical properties and thermal stability will benefit the development of compact, high power density electric propulsion devices for NASA's space missions. (c) 2006 Elsevier B.V. All rights reserved. C1 Univ Dayton, Magnet Lab, Dayton, OH 45469 USA. UES Inc, Wright Patterson Air Force Base Lab, Dayton, OH 45431 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Hohman Plating & Mfg Inc, Dayton, OH 45404 USA. RP Chen, CH (reprint author), Univ Dayton, Magnet Lab, 300 Coll Pk, Dayton, OH 45469 USA. EM Christina.chen@udri.udayton.edu NR 22 TC 12 Z9 15 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 4 PY 2006 VL 201 IS 6 BP 3430 EP 3437 DI 10.1016/j.surfcoat.2006.07.233 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 144YF UT WOS:000244831800176 ER PT J AU Rinsland, CP Boone, CD Bernath, PF Mahieu, E Zander, R Dufour, G Clerbaux, C Turquety, S Chiou, L McConnell, JC Neary, L Kaminski, JW AF Rinsland, Curtis P. Boone, Chris D. Bernath, Peter F. Mahieu, Emmanuel Zander, Rodolphe Dufour, Gaelle Clerbaux, Cathy Turquety, Solene Chiou, Linda McConnell, John C. Neary, Lori Kaminski, Jacek W. TI First space-based observations of formic acid (HCOOH): Atmospheric Chemistry Experiment austral spring 2004 and 2005 Southern Hemisphere tropical-mid-latitude upper tropospheric measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RETRIEVALS; EMISSIONS AB The first space-based measurements of upper tropospheric ( 110 - 300 hPa) formic acid (HCOOH) are reported from 0.02 cm(-1) resolution Atmospheric Chemistry Experiment (ACE) Fourier transform spectrometer solar occultation measurements at 16 degrees S - 43 degrees S latitude during late September to early October in 2004 and 2005. A maximum upper tropospheric HCOOH mixing ratio of 3.13 +/- 0.02 ppbv ( 1 ppbv = 10(-9) per unit volume), 1 sigma, at 10.5 km altitude was measured during 2004 at 29.97 degrees S latitude and a lower maximum HCOOH mixing ratio of 2.03 +/- 0.28 ppbv, at 9.5 km altitude was measured during 2005. Fire counts, back trajectories, and correlations of HCOOH mixing ratios with ACE simultaneous measurements of other fire products confirm the elevated HCOOH mixing ratios originated primarily from tropical fire emissions. A HCOOH emission factor relative to CO of 1.99 +/- 1.34 g kg(-1) during 2004 in upper tropospheric plumes is inferred from a comparison with lower mixing ratios measured during the same time period assuming HITRAN 2004 spectroscopic parameters. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Sci Applicat Int Corp, Hampton, VA 23666 USA. IPSL, Serv Aeron, F-75005 Paris, France. Meteorol Dynam Lab, F-91128 Palaiseau, France. Univ Liege, Inst Astrophys & Geophys, B-4000 Cointe Ougree, Belgium. York Univ, Dept Earth & Atmospher Sci, N York, ON M3J 1P3, Canada. RP Rinsland, CP (reprint author), NASA, Langley Res Ctr, Mail Stop 401A, Hampton, VA 23681 USA. EM c.p.rinsland@larc.nasa.gov RI Bernath, Peter/B-6567-2012; clerbaux, cathy/I-5478-2013; OI Bernath, Peter/0000-0002-1255-396X; Mahieu, Emmanuel/0000-0002-5251-0286 NR 26 TC 23 Z9 23 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 2 PY 2006 VL 33 IS 23 AR L23804 DI 10.1029/2006GL027128 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 115MY UT WOS:000242739600001 ER PT J AU Methven, J Arnold, SR Stohl, A Evans, MJ Avery, M Law, K Lewis, AC Monks, PS Parrish, DD Reeves, CE Schlager, H Atlas, E Blake, DR Coe, H Crosier, J Flocke, FM Holloway, JS Hopkins, JR McQuaid, J Purvis, R Rappengluck, B Singh, HB Watson, NM Whalley, LK Williams, PI AF Methven, J. Arnold, S. R. Stohl, A. Evans, M. J. Avery, M. Law, K. Lewis, A. C. Monks, P. S. Parrish, D. D. Reeves, C. E. Schlager, H. Atlas, E. Blake, D. R. Coe, H. Crosier, J. Flocke, F. M. Holloway, J. S. Hopkins, J. R. McQuaid, J. Purvis, R. Rappengluck, B. Singh, H. B. Watson, N. M. Whalley, L. K. Williams, P. I. TI Establishing Lagrangian connections between observations within air masses crossing the Atlantic during the International Consortium for Atmospheric Research on Transport and Transformation experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHARACTERIZATION EXPERIMENT ACE-2; MARINE BOUNDARY-LAYER; AEROSOL EVOLUTION; CARBON-MONOXIDE; OZONE; MODEL; ADVECTION; LIFETIME; TRACERS; RATES AB The ITCT-Lagrangian-2K4 (Intercontinental Transport and Chemical Transformation) experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of air masses in the free troposphere away from emissions. To this end, attempts were made to intercept and sample air masses several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts from two Lagrangian models that were used to direct the aircraft into target air masses. A novel technique then identifies Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole air samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these "coincident matches'' is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown, and the downwind minus upwind differences in tracers are discussed. C1 Univ Reading, Dept Meteorol, Reading RG6 6BB, Berks, England. Univ Leeds, Sch Earth & Environm, Leeds LS2 9JT, W Yorkshire, England. Norwegian Inst Air Res, N-2027 Kjeller, Norway. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Paris 06, CNRS, Serv Aeron, F-75252 Paris, France. Univ York, Dept Chem, York YO10 5DD, N Yorkshire, England. Univ Leicester, Dept Chem, Leicester LE1 7RH, Leics, England. NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA. Univ E Anglia, Sch Environm Sci, Norwich NR4 7TJ, Norfolk, England. Deutsch Zentrum Luft & Raumfahrt, D-82230 Oberpfaffenhofen, Germany. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Univ Manchester, Sch Earth Atmospher & Environm Sci, Manchester M13 9PL, Lancs, England. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80305 USA. Facil Airborne Atmospher Measurements, Cranfield MK43 0AL, Beds, England. Forschungszentrum, Inst Meteorol & Climate Res, D-82467 Garmisch Partenkirchen, Germany. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Leeds, Sch Chem, Leeds LS2 9JT, W Yorkshire, England. RP Methven, J (reprint author), Univ Reading, Dept Meteorol, POB 243,Earley Gate, Reading RG6 6BB, Berks, England. EM j.methven@reading.ac.uk RI Lewis, Alastair/A-6721-2008; Stohl, Andreas/A-7535-2008; Parrish, David/E-8957-2010; Manager, CSD Publications/B-2789-2015; Crosier, Jonathan/G-8952-2011; McQuaid, Jim/C-7450-2011; Evans, Mathew/A-3886-2012; Holloway, John/F-9911-2012; Coe, Hugh/C-8733-2013; Arnold, Steve/B-8856-2014; Garmisch-Pa, Ifu/H-9902-2014; Atlas, Elliot/J-8171-2015; Monks, Paul/H-6468-2016 OI Crosier, Jonathan/0000-0002-3086-4729; Arnold, Steve/0000-0002-4881-5685; Coe, Hugh/0000-0002-3264-1713; Lewis, Alastair/0000-0002-4075-3651; Stohl, Andreas/0000-0002-2524-5755; Parrish, David/0000-0001-6312-2724; McQuaid, Jim/0000-0001-8702-0415; Evans, Mathew/0000-0003-4775-032X; Holloway, John/0000-0002-4585-9594; Monks, Paul/0000-0001-9984-4390 NR 34 TC 37 Z9 38 U1 0 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 2 PY 2006 VL 111 IS D23 AR D23S62 DI 10.1029/2006JD007540 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 115NV UT WOS:000242741900005 ER PT J AU Nihashi, S Cavalieri, DJ AF Nihashi, Sohey Cavalieri, Donald J. TI Observational evidence of a hemispheric-wide ice-ocean albedo feedback effect on Antarctic sea-ice decay SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WEDDELL SEA; PHYTOPLANKTON BIOMASS; MIXED-LAYER; VARIABILITY; ATMOSPHERE; MOTION; MODEL; WIND; REDUCTION; REGION AB [ 1] The effect of ice - ocean albedo feedback ( a kind of ice-albedo feedback) on sea-ice decay is demonstrated over the Antarctic sea-ice zone from an analysis of satellite-derived hemispheric sea ice concentration and European Centre for Medium-Range Weather Forecasts (ERA-40) atmospheric data for the period 1979 - 2001. Sea ice concentration in December ( time of most active melt) correlates better with the meridional component of the wind-forced ice drift ( MID) in November ( beginning of the melt season) than the MID in December. This 1 month lagged correlation is observed in most of the Antarctic sea-ice covered ocean. Daily time series of ice concentration show that the ice concentration anomaly increases toward the time of maximum sea-ice melt. These findings can be explained by the following positive feedback effect: once ice concentration decreases ( increases) at the beginning of the melt season, solar heating of the upper ocean through the increased ( decreased) open water fraction is enhanced ( reduced), leading to ( suppressing) a further decrease in ice concentration by the oceanic heat. Results obtained from a simple ice - ocean coupled model also support our interpretation of the observational results. This positive feedback mechanism explains in part the large interannual variability of the sea-ice cover in summer. C1 Hokkaido Univ, Inst Low Temp Sci, Sapporo, Hokkaido 0600819, Japan. NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA. RP Nihashi, S (reprint author), Hokkaido Univ, Inst Low Temp Sci, Sapporo, Hokkaido 0600819, Japan. EM sohey@lowtem.hokudai.ac.jp NR 44 TC 5 Z9 6 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 2 PY 2006 VL 111 IS C12 AR C12001 DI 10.1029/2005JC003447 PG 11 WC Oceanography SC Oceanography GA 115OS UT WOS:000242744200002 ER PT J AU Jordan, NC Saleh, JH Newman, DJ AF Jordan, Nicole C. Saleh, Joseph H. Newman, Dava J. TI The extravehicular mobility unit: A review of environment, requirements, and design changes in the US spacesuit SO ACTA ASTRONAUTICA LA English DT Review DE extravehicular mobility unit; requirements evolution; design changes; flexibility ID PRODUCT MODULARITY; STATION; EMU AB Requirements are rarely static, and are ever more likely to evolve as the development time of a system stretches out and its service life increases. In this paper, we discuss the evolution of requirements for the US spacesuit, the extravehicular mobility unit (EMU), as a case study to highlight the need for flexibility in system design. We explore one fundamental environmental change, using the Space Shuttle EMU aboard the International Space Station, and the resulting EMU requirement and design changes. The EMU, like other complex systems, faces considerable uncertainty during its service life. Changes in the technical, political, or economic environment cause changes in requirements, which in turn necessitate design modifications or upgrades. We make the case that flexibility is a key attribute that needs to be embedded in the design of long-lived, complex systems to enable them to efficiently meet the inevitability of changing requirements after they have been fielded. (c) 2006 Elsevier Ltd. All rights reserved. C1 MIT, Dept Aeronaut & Astronaut, Cambridge, MA 02139 USA. RP Jordan, NC (reprint author), 2101 NASA Pkwy,Mailcode EC5, Houston, TX 77058 USA. EM nicole.c.jordan@nasa.gov NR 22 TC 14 Z9 15 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD DEC PY 2006 VL 59 IS 12 BP 1135 EP 1145 DI 10.1016/j.actaastro.2006.04.014 PG 11 WC Engineering, Aerospace SC Engineering GA 094GY UT WOS:000241229100004 ER PT J AU Rummel, JD Race, MS AF Rummel, J. D. Race, M. S. TI Got life? Hours of boredom followed by moments of sheer terror (and that's just with the press) SO ACTA ASTRONAUTICA LA English DT Article AB It may be hoped that an initial discovery of extraterrestrial life and its disclosure will be done by accident. An event of that kind would have its own dynamic, and while communications about the discovery might be strained at times, there would be less likelihood that lines of inquiry and discourse would have already been taken by the participants and the press. In an ideal world (or worlds), the discovery would come ready-made with a picture or pictures that would be useful as an immediate verification of its reality. But such is not the way of the real world (or worlds, apparently). Lessons learned from the publication of the ALH84001 results in Science magazine are indicative of what may be a more likely scenario. Nonetheless, even that publication was held in confidence for much of the time leading up to NASA's press conference, and the science team doing the work was accordingly insulated from press inquiry while the work was underway. Envisioning a Mars sample return mission, or other, similar sort of endeavor that may involve a dedicated team of scientists-working under continual public scrutiny-it is clear that the circumstances that surround any fundamental discovery about life in the sample would be quite different. Planning for a communications strategy to support the operations of a Mars sample receiving facility (or facilities) must take those circumstances into account. An optimization of the time spent communicating the results of the facility's work should acknowledge the time and effort required, and make provisions for the work to proceed without extensive interruptions-and without being influenced by the expectations of the press or the public. This paper will discuss some of the initial planning associated with the communications strategy surrounding such a facility. Published by Elsevier Ltd. C1 NASA Headquarters, Sci Miss Directorate, Washington, DC 20546 USA. SETI Inst, Mountain View, CA 94303 USA. RP Rummel, JD (reprint author), NASA Headquarters, Sci Miss Directorate, 300 E St,SW, Washington, DC 20546 USA. EM jrummel@hq.nasa.gov; mracemom@aol.com NR 3 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD DEC PY 2006 VL 59 IS 12 BP 1160 EP 1162 DI 10.1016/j.actaastro.2006.04.017 PG 3 WC Engineering, Aerospace SC Engineering GA 094GY UT WOS:000241229100007 ER PT J AU Matta, JL AF Matta, Jaime L. TI Levels of environmental ultraviolet light associated with apoptosis and necrosis in human fibroblasts SO ACTA BIOQUIMICA CLINICA LATINOAMERICANA LA Spanish DT Article ID SOLAR-SIMULATING RADIATION; SKIN-CANCER; B RADIATION; DNA-REPAIR; CUTANEOUS MELANOMA; P53; EXPRESSION; IRRADIATION; INDUCTION; EXPOSURE C1 Ponce Sch Med, Dept Pharmacol & Toxicol, Ponce, PR USA. Univ Puerto Rico, Dept Marine Sci, Mayaguez, PR 00709 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Matta, JL (reprint author), Ponce Sch Med, Dept Pharmacol & Toxicol, Ponce, PR USA. NR 47 TC 0 Z9 0 U1 0 U2 0 PU FEDERACION BIOQUIMICA PROVINCIA BUENOS AIRES PI LA PLATA, BUENOS AIRES PA CALLE 6, NO. 1344, 1900 LA PLATA, BUENOS AIRES, ARGENTINA SN 0325-2957 J9 ACTA BIOQUIM CLIN L JI Acta Bioquim. Clin. Latinoam. PD DEC PY 2006 VL 40 IS 4 BP 553 EP 560 PG 8 WC Medical Laboratory Technology SC Medical Laboratory Technology GA 174QX UT WOS:000246958700015 ER PT J AU Wolpert, DH Strauss, CEM Rajnarayan, D AF Wolpert, David H. Strauss, Charlie E. M. Rajnarayan, Dev TI Advances in distributed optimization using probability collectives SO ADVANCES IN COMPLEX SYSTEMS LA English DT Article DE distributed optimization; distributed control; probability collectives ID INTELLIGENCE AB Recent work has shown how information theory extends conventional full-rationality game theory to allow bounded rational agents. The associated mathematical framework can be used to solve distributed optimization and control problems. This is done by translating the distributed problem into an iterated game, where each agent's mixed strategy (i.e. its stochastically determined move) sets a different variable of the problem. So the expected value of the objective function of the distributed problem is determined by the joint probability distribution across the moves of the agents. The mixed strategies of the agents are updated from one game iteration to the next so as to converge on a joint distribution that optimizes that expected value of the objective function. Here, a set of new techniques for this updating is presented. These and older techniques are then extended to apply to uncountable move spaces. We also present an extension of the approach to include (in)equality constraints over the underlying variables. Another contribution is that we show how to extend the Monte Carlo version of the approach to cases where some agents have no Monte Carlo samples for some of their moves, and derive an "automatic annealing schedule." C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87544 USA. Stanford Univ, Dept Aeronaut & Astronaut, Stanford, CA 94305 USA. RP Wolpert, DH (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM cems@lanl.gov; dgorur@stanford.edu NR 37 TC 12 Z9 15 U1 0 U2 4 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0219-5259 J9 ADV COMPLEX SYST JI Adv. Complex Syst. PD DEC PY 2006 VL 9 IS 4 BP 383 EP 436 DI 10.1142/S0219525906000884 PG 54 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA 140ZB UT WOS:000244544300007 ER PT J AU Morris, R AF Morris, Robert TI Review of thinking about android epistemology SO AI MAGAZINE LA English DT Review AB This article is a review of Thinking about Android Epistemology by Kenneth Ford, Patrick Hayes, and Clark Glymour. Cambridge, MA: AAAI Press/The MIT Press. C1 NASA, Ames Res Ctr, Intelligent Syst Div, Planning & Scheduling Grp, Moffett Field, CA 94035 USA. RP Morris, R (reprint author), NASA, Ames Res Ctr, Intelligent Syst Div, Planning & Scheduling Grp, Moffett Field, CA 94035 USA. NR 7 TC 0 Z9 0 U1 2 U2 2 PU AMER ASSOC ARTIFICIAL INTELL PI MENLO PK PA 445 BURGESS DRIVE, MENLO PK, CA 94025-3496 USA SN 0738-4602 J9 AI MAG JI AI Mag. PD WIN PY 2006 VL 27 IS 4 BP 83 EP 86 PG 4 WC Computer Science, Artificial Intelligence SC Computer Science GA 120ZZ UT WOS:000243127100009 ER PT J AU Greenblatt, D Paschal, KB Yao, CS Harris, J Schaeffler, NNW Washburn, AE AF Greenblatt, David Paschal, Keith B. Yao, Chung-Sheng Harris, Jerome Schaeffler, Non-Nan W. Washburn, Anthony E. TI Experimental investigation of separation control - Part 1: Baseline and steady suction SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 2nd Flow Control Conference CY JUN 28-JUL 01, 2004 CL Portland, OR SP Amer Inst Aeronaut & Astronaut ID TURBULENT BOUNDARY-LAYER; REATTACHING FLOW; MODEL AB Low-speed flow separation over a wall-mounted hump, and its control using steady suction, were studied experimentally in order to generate a data set for the development and evaluation of computational methods. The baseline and controlled data sets comprised time-mean and unsteady surface pressure measurements, flowfield measurements using particle image velocimetry, and wall shear stress obtained via oil-film interferometry. In addition to the specific test cases studied, surface pressures for a wide variety of conditions were acquired for different Reynolds numbers and suction rates. Stereoscopic particle image velocimetry and oil-film flow visualization indicated that the baseline time-averaged separated flowfield was two-dimensional. With the application of control, mild three-dimensionality was evident in the spanwise variation of pressure recovery, reattachment location, and spanwise pressure fluctuations. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Greenblatt, D (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM david.greenblatt@pi.tu-berlin.de NR 30 TC 23 Z9 24 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2006 VL 44 IS 12 BP 2820 EP 2830 DI 10.2514/1.13817 PG 11 WC Engineering, Aerospace SC Engineering GA 119BP UT WOS:000242987500002 ER PT J AU Greenblatt, D Paschal, KB Yao, CS Harris, J AF Greenblatt, David Paschal, Keith B. Yao, Chung-Sheng Harris, Jerome TI Experimental investigation of separation control - Part 2: Zero mass-flux oscillatory blowing SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 43rd Aerospace Sciences Meeting and Exhibit CY JAN 10-13, 2005 CL Reno, NV SP AIAA ID HIGH REYNOLDS-NUMBERS; TURBULENT SHEAR-FLOW; PERIODIC EXCITATION; ORGANIZED WAVE; MECHANICS AB The control of a separated flow over a wall-mounted hump, by means of two-dimensional zero mass-flux perturbations, was studied experimentally to generate a, data set for the development and evaluation of computational methods. The companion paper (Part 1) considered details of the baseline (uncontrolled) case and a steady-suction control case. The data set for a specific zero mass-flux control case comprised static surface pressures together with phase-averaged unsteady surface pressures and particle image velocimetry flowfield measurements. Additional surface pressures were acquired for a variety of control frequencies, control amplitudes and Reynolds numbers. Due consideration was given to characterizing the flow in the vicinity of the control slot, with and without external flow, and to perturbation two-dimensionality. Triple-decomposition of the fluctuating velocity and pressure fields was employed for presenting and analyzing the experimental data. This facilitated an assessment of the mechanism of separation control and the quantification of the coherent and turbulent surface pressures, Reynolds stresses, and energy fluxes. Spanwise surface pressures and phase-averaged stereoscopic particle image velocimetry data revealed an effectively two-dimensional flowfield despite highly three-dimensional instantaneous flow structures. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Tech Univ Berlin, Hermann Foettinger Inst Fluid Mech, D-10623 Berlin, Germany. RP Greenblatt, D (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM david.greenblatt@pi.tu-berlin.de NR 18 TC 26 Z9 28 U1 1 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2006 VL 44 IS 12 BP 2831 EP 2845 DI 10.2514/1.19324 PG 15 WC Engineering, Aerospace SC Engineering GA 119BP UT WOS:000242987500003 ER PT J AU Schaeffler, NW Jenkins, LN AF Schaeffler, Nonnan W. Jenkins, Luther N. TI Isolated synthetic jet in crossflow: Experimental protocols for a validation dataset SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 2nd Flow Control Conference CY JUN 28-JUL 01, 2004 CL Portland, OR SP Amer Inst Aeronaut & Astronaut ID TURBULENCE STATISTICS; PENETRATION AB An overview of the data acquisition, reduction, and uncertainty estimates of experimental measurements made of the flowfield created by the interaction of an isolated synthetic jet and a turbulent boundary layer is presented. The experimental measurements were undertaken to serve as the second of three computational fluid dynamics validation databases for active flow control. The validation databases were first presented at the NASA Langley Research Center Workshop on CFD Validation of Synthetic Jets and Turbulent Separation Control (CFDVAL2004) in March 2004. Detailed measurements were made to document the boundary conditions for the How and also for the phase-averaged flowfield itself. Three component laser-Doppler velocimetry, 2-D particle image velocimetry, and stereo particle image velocimetry were used to document the phase-averaged velocity field and the turbulent stresses. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Schaeffler, NW (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 43 TC 13 Z9 13 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2006 VL 44 IS 12 BP 2846 EP 2856 DI 10.2514/1.13743 PG 11 WC Engineering, Aerospace SC Engineering GA 119BP UT WOS:000242987500004 ER PT J AU Georgiadis, NJ Yoder, DA Engblom, WA AF Georgiadis, Nicholas J. Yoder, Dennis A. Engblom, William A. TI Evaluation of modified two-equation turbulence models for jet flow predictions SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 43rd Aerospace Sciences Meeting and Exhibit CY JAN 10-13, 2005 CL Reno, NV SP AIAA ID NOISE; LAYER AB Three two-equation turbulence models developed specifically to improve prediction of jet flowfields are investigated. These models are the Tam-Ganesan k-epsilon formulation, a standard k-epsilon model with modification for heated jets referred to as the PAB temperature correction, and a standard k-epsilon model employing variable diffusion for the k and 8 equations. Two standard two-equation models are also investigated for comparison with the modified formulations. The standard models are the Chien k-epsilon and Menter shear stress transport formulations. All of the models were investigated for a reference nozzle producing heated and unheated jets at a low acoustic Mach number of 0.5 to avoid complications of large compressibility effects. The primary deficiency of the standard models was the delayed initial jet mixing rate. All of the modified turbulence model formulations provided improved mean flow predictions relative to the standard models. The improved mixing rate enabled by the Tam-Ganesan model and the variable diffusion correction resulted from increased turbulent diffusion enabled by both models. The Tam-Ganesan model and PAB temperature correction improved predictions of mean axial velocities for the heated jet, but did not improve prediction of the calculated turbulent kinetic energy fields. C1 NASA, John H Glenn Res Ctr, Prop Syst Div, Cleveland, OH 44135 USA. Embry Riddle Aeronaut Univ, Daytona Beach, FL 32114 USA. RP Georgiadis, NJ (reprint author), NASA, John H Glenn Res Ctr, Prop Syst Div, Mail Stop 86-7, Cleveland, OH 44135 USA. NR 29 TC 11 Z9 12 U1 0 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2006 VL 44 IS 12 BP 3107 EP 3114 DI 10.2514/1.22650 PG 8 WC Engineering, Aerospace SC Engineering GA 119BP UT WOS:000242987500031 ER PT J AU Goldstein, ME AF Goldstein, M. E. TI Hybrid Reynolds-averaged Navier-Stokes/large eddy simulation approach for predicting jet noise SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT 12th AIAA/CEAS Aeroacoustics Conference CY MAY 08-10, 2006 CL Cambridge, MA SP AIAA ID TURBULENCE; NUMBER; SOUND AB Hybrid acoustic prediction methods have an important advantage over the current Reynolds-averaged Navier-Stokes based methods in that they only involve modeling of the relatively universal subscale motion and not the configuration-dependent larger-scale turbulence. Unfortunately, they are unable to account for the high-frequency sound generated by the turbulence in the initial mixing layers. This paper introduces an alternative approach that directly calculates the sound from a hybrid Reynolds-averaged Navier-Stokes/large eddy simulation flow model (which can resolve the steep gradients in the initial mixing layers near the nozzle lip) and adopts modeling techniques similar to those used in current Reynolds-averaged Navier-Stokes based noise prediction methods to determine the unknown sources in the equations for the remaining unresolved components of the sound field. The resulting prediction method would then be intermediate between the current noise prediction codes and previously proposed hybrid noise prediction methods. C1 NASA, John H Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Goldstein, ME (reprint author), NASA, John H Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. NR 24 TC 5 Z9 5 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2006 VL 44 IS 12 BP 3136 EP 3142 DI 10.2514/1.22852 PG 7 WC Engineering, Aerospace SC Engineering GA 119BP UT WOS:000242987500034 ER PT J AU Yao, CS Chen, FJ Neuhart, D AF Yao, Chungsheng Chen, Fang Jenq Neuhart, Dan TI Synthetic jet flowfield database for computational fluid dynamics validation SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 2nd Flow Control Conference CY JUN 28-JUL 01, 2004 CL Portland, OR SP Amer Inst Aeronaut & Astronaut C1 NASA, Langley Res Ctr, Flow Phys & Control Branch, Hampton, VA 23681 USA. RP Yao, CS (reprint author), NASA, Langley Res Ctr, Flow Phys & Control Branch, MS 170, Hampton, VA 23681 USA. NR 8 TC 10 Z9 10 U1 0 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2006 VL 44 IS 12 BP 3153 EP 3157 DI 10.2514/1.13819 PG 5 WC Engineering, Aerospace SC Engineering GA 119BP UT WOS:000242987500038 ER PT J AU Greenblatt, D AF Greenblatt, David TI Managing flap vortices via separation control (vol 44, pg 2755, 2006) SO AIAA JOURNAL LA English DT Correction C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Greenblatt, D (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2006 VL 44 IS 12 BP 3165 EP 3165 DI 10.2514/1.28836 PG 1 WC Engineering, Aerospace SC Engineering GA 119BP UT WOS:000242987500041 ER PT J AU Guise, JM Deering, S Kanki, B Osterweil, P Li, H Stanford, S Lowe, N AF Guise, Jeanne-Marie Deering, Shad Kanki, Barbara Osterweil, Patricia Li, Hong Stanford, Susan Lowe, Nancy TI Storc OB safety initiative: Validating a tool to evaluate team performance SO AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY LA English DT Meeting Abstract CT 27th Annual Meeting of the Society-of-Maternal-Fetal-Medicine CY FEB 05-10, 2007 CL San Francisco, CA SP Soc Maternal Fetal Med C1 Oregon Hlth Sci Univ, Div Maternal Fetal Med, Portland, OR 97201 USA. Madigan Army Med Ctr, Div Maternal Fetal Med, Tacoma, WA 98431 USA. NASA, Ames Res Ctr, Human Factors Res & Technol Div, Moffett Field, CA 94035 USA. Oregon Hlth Sci Univ, Portland, OR 97201 USA. Oregon Hlth Sci Univ, SON Primary Care, Portland, OR 97201 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MOSBY-ELSEVIER PI NEW YORK PA 360 PARK AVENUE SOUTH, NEW YORK, NY 10010-1710 USA SN 0002-9378 J9 AM J OBSTET GYNECOL JI Am. J. Obstet. Gynecol. PD DEC PY 2006 VL 195 IS 6 SU S MA 722 BP S216 EP S216 DI 10.1016/j.ajog.2006.10.783 PG 1 WC Obstetrics & Gynecology SC Obstetrics & Gynecology GA 116WM UT WOS:000242834500719 ER PT J AU Korendyke, CM Brown, CM Thomas, RJ Keyser, C Davila, J Hagood, R Hara, H Heidemann, K James, AM Lang, J Mariska, JT Moser, J Moye, R Myers, S Probyn, BJ Seely, JF Shea, J Shepler, E Tandy, J AF Korendyke, Clarence M. Brown, Charles M. Thomas, Roger J. Keyser, Christian Davila, Joseph Hagood, Robert Hara, Hirohisa Heidemann, Klaus James, Adrian M. Lang, James Mariska, John T. Moser, John Moye, Robert Myers, Steven Probyn, Brian J. Seely, John F. Shea, John Shepler, Ed Tandy, Jason TI Optics and mechanisms for the Extreme-Ultraviolet Imaging Spectrometer on the Solar-B satellite SO APPLIED OPTICS LA English DT Article ID CORRECTED CONCAVE GRATINGS; CALIBRATION; LINES AB The Extreme-Ultraviolet Imaging Spectrometer (EIS) is the first of a new generation of normal-incidence, two-optical-element spectroscopic instruments developed for space solar extreme-ultraviolet astronomy. The instrument is currently mounted on the Solar-B satellite for a planned launch in late 2006. The instrument observes in two spectral bands, 170-210 angstrom and 250-290 angstrom. The spectrograph geometry and grating prescription were optimized to obtain excellent imaging while still maintaining readily achievable physical and fabrication tolerances. A refined technique using low ruling density surrogate gratings and optical metrology was developed to align the instrument with visible light. Slit rasters of the solar surface are obtained by mechanically tilting the mirror. A slit exchange mechanism allows selection among four slits at the telescope focal plane. Each slit is precisely located at the focal plane. The spectrograph imaging performance was optically characterized in the laboratory. The resolution was measured using the Mg III and Ne III lines in the range of 171-200 angstrom. The He II line at 256 angstrom and Ne III lines were used in the range of 251-284 angstrom. The measurements demonstrate an equivalent resolution of similar to 2 are see on the solar surface, in good agreement with the predicted performance. We describe the EIS optics, mechanisms, and measured performance. (c) 2006 Optical Society of America. C1 USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Solar Phys Lab, Greenbelt, MD 20771 USA. Swales Aerosp, Beltsville, MD 20705 USA. Natl Astron Observ, Mitaka, Tokyo 1818588, Japan. Carl Zeiss Laser Opt GmbH, D-73447 Oberkochen, Germany. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Birmingham, Sch Phys & Space Res, Birmingham B15 2TT, W Midlands, England. Perdix Corp, Wilton, NH 03086 USA. RP Korendyke, CM (reprint author), USN, Res Lab, Div Space Sci, 4555 Overlook Ave SW, Washington, DC 20375 USA. EM cbrown@ssd5.nrl.navy.mil OI James, Adrian/0000-0002-0023-4363 NR 23 TC 64 Z9 64 U1 0 U2 12 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD DEC 1 PY 2006 VL 45 IS 34 BP 8674 EP 8688 DI 10.1364/AO.45.008674 PG 15 WC Optics SC Optics GA 111SC UT WOS:000242473800013 PM 17119564 ER PT J AU Hollingsworth, DK Witte, LC Hinke, J Hurlbert, K AF Hollingsworth, D. Keith Witte, Larry C. Hinke, Jaime Hurlbert, Kathryn TI Reduction in emittance of thermal radiator coatings caused by the accumulation of a Martian dust simulant SO APPLIED THERMAL ENGINEERING LA English DT Article DE thermal radiators; emittance measurement; Martian dust AB Measurements were made of the effective emittance of three types of radiator coatings as a Martian dust simulant was added to the radiator surfaces. The apparatus consisted of multiple radiator coupons on which Carbondale Red Clay dust was deposited. The coupon design employed guard heating to achieve the accuracy required for acceptable emittance calculations. The apparatus was contained in a vacuum chamber that featured a liquid-nitrogen cooled shroud that simulated the Martian sky temperature. Three high-emittance radiator coatings were tested: two while silicate paints, Z-93P and NS-43G, and a silver Teflon film. Radiator temperatures ranged from 250 to 350 K with sky temperatures from 185 to 248 K. As dust was added to the radiator surfaces, the effective emittance of all three coatings decreased from initial values near 0.9 to a value near 0.4. A low-emittance control surface, polished aluminum, demonstrated a rise in effective emittance for thin dust layers, and then a decline as the dust layer thickened. This behavior is attributed to the conductive resistance caused by the dust layer. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Houston, Dept Mech Engn, Houston, TX 77204 USA. NASA, Lyndon B Johnson Space Ctr, Washington, DC 20546 USA. RP Hollingsworth, DK (reprint author), Univ Houston, Dept Mech Engn, Houston, TX 77204 USA. EM hollingsworth@uh.edu NR 5 TC 5 Z9 5 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD DEC PY 2006 VL 26 IS 17-18 BP 2383 EP 2392 DI 10.1016/j.applthermaleng.2006.02.034 PG 10 WC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics SC Thermodynamics; Energy & Fuels; Engineering; Mechanics GA 076UV UT WOS:000239984400039 ER PT J AU Oehler, DZ Robert, F Mostefaoui, S Meibom, A Selo, M McKay, DS AF Oehler, Dorothy Z. Robert, Francois Mostefaoui, Smail Meibom, Anders Selo, Madeleine McKay, David S. TI Chemical mapping of proterozoic organic matter at submicron spatial resolution SO ASTROBIOLOGY LA English DT Article DE biosignatures; chemical fossils; precambrian fossils; proterozoic; microbial mats ID LASER-RAMAN IMAGERY; BLUE-GREEN-ALGAE; WESTERN-AUSTRALIA; IN-SITU; CARBON; MICROFOSSILS; NITROGEN; FOSSILS; SILICA; SILICIFICATION AB A NanoSIMS ion microprobe was used to map the submicron-scale distributions of carbon, nitrogen, sulfur, silicon, and oxygen in organic microfossils and laminae in a thin section of the similar to 0.85 billion year old Bitter Springs Formation of Australia. The data provide clues about the original chemistry of the microfossils, the silicification process, and the biosignatures of specific microorganisms and microbial communities. Chemical maps of fossil unicells and filaments revealed distinct wall- and sheath-like structures enriched in C, N, and S, consistent with their accepted biological origin. Surprisingly, organic laminae, previously considered to be amorphous, also exhibited filamentous and apparently compressed spheroidal structures defined by strong enrichments in C, N, and S. By analogy to NanoSIMS data from the well-preserved microfossils, these structures were interpreted as being of biological origin, most likely representing densely packed remnants of microbial mats. Given that the preponderance of organic matter in Precambrian sediments is similarly "amorphous," our findings indicate that a re-evaluation of ancient specimens via in situ structural, chemical, and isotopic study is warranted. Our analyses have led us to propose new criteria for assessing the biogenicity of problematic kerogenous materials, and, thus, these criteria can be applied to assessments of poorly preserved or fragmentary organic residues in early Archean sediments and any that might occur in meteorites or other extraterrestrial samples. C1 NASA, Johnson Space Ctr, ARES, Astrobiol Grp, Houston, TX 77058 USA. Museum Nat Hist Naturelle, Lab Etud Matiere Extraterr, Paris, France. RP Oehler, DZ (reprint author), NASA, Johnson Space Ctr, ARES, Astrobiol Grp, Mail Code KA, Houston, TX 77058 USA. EM dorothy.z.oehler@nasa.gov NR 42 TC 31 Z9 33 U1 4 U2 17 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD DEC PY 2006 VL 6 IS 6 BP 838 EP 850 DI 10.1089/ast.2006.6.838 PG 13 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 116YI UT WOS:000242839300004 PM 17155884 ER PT J AU Tinetti, G Meadows, VS Crisp, D Kiang, NY Kahn, BH Bosc, E Fishbein, E Velusamy, T Turnbull, M AF Tinetti, Giovanna Meadows, Victoria S. Crisp, David Kiang, Nancy Y. Kahn, Brian H. Bosc, Emmanuel Fishbein, Evan Velusamy, Thangasamy Turnbull, Margaret TI Detectability of planetary characteristics in disk-averaged spectra II: Synthetic spectra and light-curves of earth SO ASTROBIOLOGY LA English DT Article DE radiative transfer; remote sensing; spectroscopy; earth; extrasolar terrestrial planets; planetary science ID TERRESTRIAL PLANETS; RED-EDGE; VEGETATION; CLIMATE; BANDS; MODEL; AIRS AB Spatially and spectrally resolved models were used to explore the observational sensitivity to changes in atmospheric and surface properties and the detectability of surface biosignatures in the globally averaged spectra and light-curves of the Earth. Compared with previous efforts to characterize the Earth using disk-averaged models, a more comprehensive and realistic treatment of the surface and atmosphere was taken into account here. Our results are presented as a function of viewing geometry and phases at both visible/near-infrared (0.5-1.7 M,m) and mid-infrared (5-25 mu m) wavelength ranges, applicable to the proposed NASA-Terrestrial Planet Finder visible coronagraph and mid-infrared interferometer and to the ESA-Darwin mission architectures. Clouds can change the thermal emission by as much as 50% compared with the cloud-free case and increase the visible albedo by up to 500% for completely overcast cases at the dichotomy phase. Depending on the observed phase and their distribution and type, clouds can also significantly alter the spectral shape. Moreover, clouds impact the detectability of surface biosignatures in the visible wavelength range. Modeling the disk-averaged sensitivity to the "red-edge," a distinctive spectral signature of vegetation, showed that Earth's land vegetation could be seen in disk-averaged spectra, even with cloud cover, when the signal was averaged over the daily time scale. We found that vegetation is more readily discriminated from clouds at dichotomy (50% illumination) rather than at full phase. The detectability of phytoplankton was also explored, but was found to be more difficult to detect in the disk-average than land vegetation. C1 Inst Astrophys Paris, F-75014 Paris, France. NASA Astrobiol Inst, Pasadena, CA USA. Spitzer Space Ctr, Pasadena, CA USA. CALTECH, Jet Propuls Lab, Pasadena, CA USA. NASA Goddard Inst Space Studies, New York, NY USA. Carnegie Inst Washington, Washington, DC 20005 USA. RP Tinetti, G (reprint author), Inst Astrophys Paris, 98bis Blvd Arago, F-75014 Paris, France. EM tinetti@iap.fr OI Tinetti, Giovanna/0000-0001-6058-6654 NR 22 TC 59 Z9 59 U1 1 U2 9 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD DEC PY 2006 VL 6 IS 6 BP 881 EP 900 DI 10.1089/ast.2006.6.881 PG 20 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 116YI UT WOS:000242839300007 PM 17155887 ER PT J AU Geller, MJ Kenyon, SJ Barton, EJ Jarrett, TH Kewley, LJ AF Geller, Margaret J. Kenyon, Scott J. Barton, Elizabeth J. Jarrett, Thomas H. Kewley, Lisa J. TI Infrared properties of close pairs of galaxies SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : interactions; galaxies : photometry; galaxies : starburst ID PISCES-PERSEUS SUPERCLUSTER; STAR-FORMATION RATES; CFA REDSHIFT SURVEY; NEARBY FIELD GALAXIES; DIGITAL SKY SURVEY; 21 CM SURVEY; INTERACTING GALAXIES; MERGING GALAXIES; SPIRAL GALAXIES; STELLAR POPULATIONS AB We discuss spectroscopy and IR photometry for a complete sample of similar to 800 galaxies in close pairs objectively selected from the second Center for Astrophysics redshift survey. We use the Two Micron All Sky Survey to compare near-IR color-color diagrams for our sample with the Nearby Field Galaxy Sample and with a set of IRAS flux-limited pairs from Surace and coworkers. We construct a basic statistical model to explore the physical sources of the substantial differences among these samples. The model explains the spread of near-IR colors and is consistent with a picture in which central star formation is triggered by the galaxy-galaxy interaction before a merger occurs. For 160 galaxies we report new, deep JHK photometry within our spectroscopic aperture, and we use the combined spectroscopic and photometric data to explore the physical conditions in the central bursts. We find a set of objects with H-K >= 0: 45 and with a large F-FIR/F-H. We interpret the very red H-K colors as evidence for 600-1000 K dust within compact star-forming regions, perhaps similar to super star clusters identified in individual well-studied interacting galaxies. The galaxies in our sample are candidate "hidden'' bursts or, possibly, "hidden'' active galactic nuclei. Over the entire pair sample, both spectroscopic and photometric data show that the specific star formation rate decreases with the projected separation of the pair. The data suggest that the near-IR color-color diagram is also a function of the projected separation; all of the objects with central near-IR colors indicative of bursts of star formation lie at small projected separation. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. CALTECH, Jet Propuls Lab, Spitzer Sci Ctr, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Geller, MJ (reprint author), Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. EM mgeller@cfa.harvard.edu; skenyon@cfa.harvard.edu; ebarton@uci.edu; jarrett@ipac.caltech.edu; kewley@ifa.hawaii.edu OI Kenyon, Scott/0000-0003-0214-609X NR 93 TC 27 Z9 27 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 2006 VL 132 IS 6 BP 2243 EP 2259 DI 10.1086/508258 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MC UT WOS:000242529100003 ER PT J AU Meixner, M Gordon, KD Indebetouw, R Hora, JL Whitney, B Blum, R Reach, W Bernard, JP Meade, M Babler, B Engelbracht, CW For, BQ Misselt, K Vijh, U Leitherer, C Cohen, M Churchwell, EB Boulanger, F Frogel, JA Fukui, Y Gallagher, J Gorjian, V Harris, J Kelly, D Kawamura, A Kim, S Latter, WB Madden, S Markwick-Kemper, C Mizuno, A Mizuno, N Mould, J Nota, A Oey, MS Olsen, K Onishi, T Paladini, R Panagia, N Perez-Gonzalez, P Shibai, H Sato, S Smith, L Staveley-Smith, L Tielens, AGGM Ueta, T Van Dyk, S Volk, K Werner, M Zaritsky, D AF Meixner, Margaret Gordon, Karl D. Indebetouw, Remy Hora, Joseph L. Whitney, Barbara Blum, Robert Reach, William Bernard, Jean-Philippe Meade, Marilyn Babler, Brian Engelbracht, Charles W. For, Bi-Qing Misselt, Karl Vijh, Uma Leitherer, Claus Cohen, Martin Churchwell, Ed B. Boulanger, Francois Frogel, Jay A. Fukui, Yasuo Gallagher, Jay Gorjian, Varoujan Harris, Jason Kelly, Douglas Kawamura, Akiko Kim, SoYoung Latter, William B. Madden, Suzanne Markwick-Kemper, Ciska Mizuno, Akira Mizuno, Norikazu Mould, Jeremy Nota, Antonella Oey, M. S. Olsen, Knut Onishi, Toshikazu Paladini, Roberta Panagia, Nino Perez-Gonzalez, Pablo Shibai, Hiroshi Sato, Shuji Smith, Linda Staveley-Smith, Lister Tielens, A. G. G. M. Ueta, Toshiya Van Dyk, Schuyler Volk, Kevin Werner, Michael Zaritsky, Dennis TI Spitzer survey of the Large Magellanic Cloud: Surveying the agents of a galaxy's evolution (sage). I. Overview and initial results SO ASTRONOMICAL JOURNAL LA English DT Article DE dust; extinction; ISM : general; Magellanic Clouds; stars : AGB and post-AGB; stars : formation; stars : mass loss; supergiants; surveys ID STAR-FORMATION HISTORY; INFRARED ARRAY CAMERA; COLOR-MAGNITUDE DIAGRAMS; GIANT MOLECULAR CLOUDS; SPACE-TELESCOPE; DWARF GALAXIES; CO SURVEY; ABSOLUTE CALIBRATION; STELLAR POPULATIONS; INTERSTELLAR DUST AB We are performing a uniform and unbiased imaging survey of the Large Magellanic Cloud (LMC; similar to 7 degrees x 7 degrees) using the IRAC (3.6, 4.5, 5.8, and 8 mu m) and MIPS (24, 70, and 160 mu m) instruments on board the Spitzer Space Telescope in the Surveying the Agents of a Galaxy's Evolution (SAGE) survey, these agents being the interstellar medium (ISM) and stars in the LMC. This paper provides an overview of the SAGE Legacy project, including observing strategy, data processing, and initial results. Three key science goals determined the coverage and depth of the survey. The detection of diffuse ISM with column densities > 1: 2; 1021 H cm(-2) permits detailed studies of dust processes in the ISM. SAGE's point-source sensitivity enables a complete census of newly formed stars with masses > 3 M-circle dot that will determine the current star formation rate in the LMC. SAGE's detection of evolved stars with mass-loss rates > 1 x 10(-8) M-circle dot yr(-1) will quantify the rate at which evolved stars inject mass into the ISM of the LMC. The observing strategy includes two epochs in 2005, separated by 3 months, that both mitigate instrumental artifacts and constrain source variability. The SAGE data are nonproprietary. The data processing includes IRAC and MIPS pipelines and a database for mining the point-source catalogs, which will be released to the community in support of Spitzer proposal cycles 4 and 5. We present initial results on the epoch 1 data for a region near N79 and N83. The MIPS 70 and 160 mu m images of the diffuse dust emission of the N79/N83 region reveal a similar distribution to the gas emissions, especially the H I 21 cm emission. The measured point-source sensitivity for the epoch 1 data is consistent with expectations for the survey. The point-source counts are highest for the IRAC 3.6 mu m band and decrease dramatically toward longer wavelengths, consistent with the fact that stars dominate the point-source catalogs and the dusty objects detected at the longer wavelengths are rare in comparison. The SAGE epoch 1 point-source catalog has similar to 4 x 10(6) sources, and more are anticipated when the epoch 1 and 2 data are combined. Using Milky Way ( MW) templates as a guide, we adopt a simplified point-source classification to identify three candidate groups-stars without dust, dusty evolved stars, and young stellar objects-that offer a starting point for this work. We outline a strategy for identifying foreground MW stars, which may comprise as much as 18% of the source list, and background galaxies, which may comprise similar to 12% of the source list. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Space Sci Inst, Boulder, CO 80301 USA. Cerro Tololo Interamer Observ, La Serena, Chile. CALTECH, Jet Prop Lab, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Ctr Etud Spatiale Rayonnements, Direct Rech, F-31055 Toulouse, France. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. CNRS, Inst Astrophys Paris, UPR 341, F-75014 Paris, France. Assoc Univ Res Astron Inc, Washington, DC 20005 USA. Nagoya Univ, Dept Astrophys, Chikusa Ku, Nagoya, Aichi 46401, Japan. Jet Prop Lab, Pasadena, CA 91109 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Commissart Energie Atom Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. CSIRO, Head Off, Melbourne, Vic 3001, Australia. NASA, Ames Res Ctr, SOFIA Off, Moffett Field, CA 94035 USA. Gemini Observ, No Operat Ctr, Hilo, HI 96720 USA. RP Meixner, M (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM meixner@stsci.edu; kgordon@as.arizona.edu; remy@virginia.edu; jhora@cfa.harvard.edu; bwhitney@spacescience.org; rblum@ctio.noao.edu; reach@ipac.caltech.edu; jean-philippe.bernard@cesr.fr; meade@sal.wisc.edu; brian@sal.wisc.edu; cengelbracht@as.arizona.edu; biqing@email.arizona.edu; kmisselt@as.arizona.edu; vijh@stsci.edu; leitherer@stsci.edu; mcohen@astro.berkeley.edu; ebc@astro.wisc.edu; francois.boulanger@ias.u-psud.fr; jfrogel@aura-astronomy.org; fukui@a.phys.nagoya-u.ac.jp; jsg@astro.wisc.edu; varoujan.gorjian@jpl.nasa.gov; jharris@as.arizona.edu; dkelly@as.arizona.edu; kawamura@a.phys.nagoya-u.ac.jp; sykim@pha.jhu.edu; smadden@cea.fr; fk2n@virginia.edu; mizuno@a.phys.nagoya-u.ac.jp; mizuno@a.phys.nagoya-u.ac.jp; jmould@noao.edu; nota@stsci.edu; msoey@umich.edu; kolsen@ctio.noao.edu; ohnishi@a.phys.nagoya-u.ac.jp; paladini@ipac.caltech.edu; panagia@stsci.edu; pgperez@as.arizona.edu; shibai@nagoya-u.jp; ssato@z.phys.nagoya-u.ac.jp; ljs@zuaxp0.star.ucl.ac.uk; lister.staveley-smith@csiro.au; tielens@astro.rug.nl; tueta@mail.sofia.usra.edu; vandyk@ipac.caltech.edu; kvolk@gemini.edu; mwerner@sirtfweb.jpl.nasa.gov; dennis@fishingholes.as.arizona.edu RI Reach, William/C-4710-2008; Staveley-Smith, Lister/A-1683-2011; Kemper, Francisca/D-8688-2011; Perez-Gonzalez, Pablo/J-2871-2016; OI Staveley-Smith, Lister/0000-0002-8057-0294; Kemper, Francisca/0000-0003-2743-8240; Perez-Gonzalez, Pablo/0000-0003-4528-5639; Babler, Brian/0000-0002-6984-5752; Hora, Joseph/0000-0002-5599-4650; Reach, William/0000-0001-8362-4094; Van Dyk, Schuyler/0000-0001-9038-9950 NR 77 TC 402 Z9 402 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD DEC PY 2006 VL 132 IS 6 BP 2268 EP 2288 DI 10.1086/508185 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MC UT WOS:000242529100005 ER PT J AU Jacobson, RA Antreasian, PG Bordi, JJ Criddle, KE Ionasescu, R Jones, JB Mackenzie, RA Meek, MC Parcher, D Pelletier, FJ Owen, WM Roth, DC Roundhill, IM Stauch, JR AF Jacobson, R. A. Antreasian, P. G. Bordi, J. J. Criddle, K. E. Ionasescu, R. Jones, J. B. Mackenzie, R. A. Meek, M. C. Parcher, D. Pelletier, F. J. Owen, W. M., Jr. Roth, D. C. Roundhill, I. M. Stauch, J. R. TI The gravity field of the Saturnian system from satellite observations and spacecraft tracking data SO ASTRONOMICAL JOURNAL LA English DT Article DE gravitation; planets and satellites : general; planets and satellites : individual (Saturn) ID RADIO OCCULTATION MEASUREMENTS; CASSINI IMAGING SCIENCE; VOYAGER OBSERVATIONS; ATMOSPHERE; MASSES; IAPETUS; ORBITS; TETHYS; VALUES; MIMAS AB We present values for the masses of Saturn and its major satellites, the zonal harmonics in the spherical harmonic expansion of Saturn's gravitational potential, and the orientation of the pole of Saturn. We determined these values using an extensive data set: satellite astrometry from Earth-based observatories and the Hubble Space Telescope; Earth-based, Voyager 1, and Voyager 2 ring occultation measurements; Doppler tracking data from Pioneer 11; and Doppler tracking, radiometric range, and imaging data from Voyager 1, Voyager 2, and Cassini. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jacobson, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM robert.jacobson@jpl.nasa.gov NR 54 TC 122 Z9 123 U1 1 U2 8 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 2006 VL 132 IS 6 BP 2520 EP 2526 DI 10.1086/508812 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MC UT WOS:000242529100028 ER PT J AU de Gregorio-Monsalvo, I Gomez, JF Suarez, O Kuiper, TBH Anglada, G Patel, NA Torrelles, JM AF de Gregorio-Monsalvo, Itziar Gomez, Jose F. Suarez, Olga Kuiper, Thomas B. H. Anglada, Guillem Patel, Nimesh A. Torrelles, Jose M. TI High-resolution observations of water masers in Bok globules SO ASTRONOMICAL JOURNAL LA English DT Article DE ISM : globules; ISM : jets and outflows; ISM : molecules; masers; radio continuum : ISM; stars : pre-main-sequence ID YOUNG STELLAR OBJECTS; STAR-FORMING REGIONS; RADIO-CONTINUUM EMISSION; SOUTH-GALACTIC-CAP; H2O MASERS; DARK CLOUDS; MOLECULAR CLOUDS; CARBON-MONOXIDE; SUBMILLIMETER MAPS; BIPOLAR OUTFLOW AB We present Very Large Array observations at 1.3 cm of several water maser detections obtained by previous single-dish studies of Bok globules in the 1988 Clemens and Barvainis (CB) catalog. We report water maser emission in CB 3 (CB 3-mm), CB 54 (IRAS 07020-1618), CB 101 (IRAS 17503-0833), and CB 232 (IRAS 21352+4307) and non-detection toward CB 65 (IRAS 16277-2332) and CB 205 (IRAS 19433+2743). These are the first reported interferometric observations of water masers in Bok globules of the CB catalog. We also present single-dish observations of millimeter and centimeter spectral lines toward CB 101 (IRAS 17503-0833) and CB 65 (IRAS 16277-2332). All the maser emission seems to be associated with star-forming regions hosting bipolar molecular outflows, except IRAS 17503-0833 in CB 101, which we suggest to be a possible Mira evolved star, and IRAS 16277-2332 in CB 65, which is of unknown nature. We have used the precise position of the maser emission to derive information about the powering source of the masers. By analyzing the spatio-kinematical distribution of the water masers, we confirm the millimeter source CB 3-mm as the most likely powering source of the CB 3 masers. We propose the near-IR source CB 232 YC1-I as the best candidate for pumping the maser emission observed in CB 232, while in CB 54 we suggest that the pumping source of the masers could be located at the position of an elongated feature observed in near-IRmaps. C1 INTA, Lab Astrofis Espacial & Fis Fundamental, E-28080 Madrid, Spain. CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CSIC, Inst Ciencias Espacio, E-08028 Barcelona, Spain. Univ Barcelona, Fac Fis, Inst estudis Espacials Catalunya, E-08028 Barcelona, Spain. RP de Gregorio-Monsalvo, I (reprint author), INTA, Lab Astrofis Espacial & Fis Fundamental, Apartado 50727, E-28080 Madrid, Spain. EM idegrego@eso.org; jfg@iaa.es; olga@laeff.inta.es; kuiper@jpl.nasa.gov; guillem@iaa.es; npatel@cfa.harvard.edu; torrelles@ieec.fcr.es RI Gomez, Jose Francisco/D-8392-2016; OI Gomez, Jose Francisco/0000-0002-7065-542X; Torrelles, Jose Maria/0000-0002-6896-6085 NR 79 TC 5 Z9 5 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 2006 VL 132 IS 6 BP 2584 EP 2595 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MC UT WOS:000242529100033 ER PT J AU Haisch, KE Barsony, M Ressler, ME Greene, TP AF Haisch, Karl E., Jr. Barsony, Mary Ressler, Michael E. Greene, Thomas P. TI Mid-infrared observations of Class I/flat-spectrum systems in six nearby molecular clouds SO ASTRONOMICAL JOURNAL LA English DT Article DE binaries : close; stars : formation; stars : pre-main-sequence ID YOUNG STELLAR OBJECTS; T-TAURI STARS; MAIN-SEQUENCE STARS; RHO-OPHIUCHI CLOUD; 2-DIMENSIONAL RADIATIVE-TRANSFER; INFRARED MULTIPLICITY SURVEY; SOLAR-TYPE STARS; CLASS-I; FORMING REGIONS; IMAGING SURVEY AB We have obtained new mid-infrared observations of 65 Class I/flat-spectrum (FS) objects in the Perseus, Taurus, Chamaeleon I and II, rho Ophiuchi, and Serpens dark clouds. These objects represent a subset of the young stellar objects (YSOs) from our previous near-infrared multiplicity surveys. We detected 45 out of 48 (94%) of the single sources, 16 out of 16 (100%) of the primary components, and 12 out of 16 (75%) of the secondary/triple components of the binary/multiple objects surveyed. One target, IRS 34, a 0 ''.31 separation FS binary, remains unresolved at near-infrared wavelengths. The composite spectral energy distributions for all of our sample YSOs are either Class I or FS, and in 15 out of 16 multiple systems at least one of the individual components displays a Class I or FS spectral index. However, the occurrence of mixed pairings, such as FS with Class I, FS with Class II, and, in one case, an FS with a Class III (Cha I T33B), is suprisingly frequent. Such behavior is not consistent with that of multiple systems among T Tauri stars (TTSs), where the companion of a classical TTS also tends to be a classical TTS, although other mixed pairings have been previously observed among Class II YSOs. Based on an analysis of the spectral indices of the individual binary components, there appears to be a higher proportion of mixed Class I/FS systems (65%-80%) than that of mixed classical and weak-lined TTSs (25%-40%), demonstrating that the envelopes of Class I/FS systems are rapidly evolving during this evolutionary phase. In general, the individual binary/multiple components suffer very similar extinctions, A(v), suggesting that most of the line-of-sight material is either in the foreground of the molecular cloud or circumbinary. We report the discovery of a steep spectral index secondary companion to ISO-Cha I 97, detected for the first time via our mid-infrared observations. In our previous near-infrared imaging survey of binary/ multiple Class I and FS YSOs, ISO-Cha I 97 appeared to be single. With a spectral index of alpha >= +3.9, the secondary component of this system is a member of a rare class of very steep spectral index YSOs, those with alpha > +3. Only three such objects have previously been reported, all of which are either Class 0 or Class I. C1 Utah Valley State Coll, Dept Phys, Orem, UT 84058 USA. San Francisco State Univ, Dept Phys & Astron, San Francisco, CA 94132 USA. Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Haisch, KE (reprint author), Utah Valley State Coll, Dept Phys, 800 W Univ Pkwy, Orem, UT 84058 USA. EM haischka@uvsc.edu; mbarsony@stars.sfsu.edu; michael.e.ressler@jpl.nasa.gov; tgreene@mail.arc.nasa.gov NR 67 TC 13 Z9 13 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 2006 VL 132 IS 6 BP 2675 EP 2684 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MC UT WOS:000242529100039 ER PT J AU Jaffe, TR Banday, AJ Eriksen, HK Gorski, KM Hansen, FK AF Jaffe, T. R. Banday, A. J. Eriksen, H. K. Gorski, K. M. Hansen, F. K. TI Bianchi type VIIh models and the WMAP 3-year data SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE cosmic microwave background; cosmology : observations ID ANISOTROPY-PROBE DATA; MICROWAVE; TEMPLATE; ISOTROPY; SPHERE AB Context. A specific example of Bianchi type VIIh models, i.e. those including universal rotation (vorticity) and differential expansion (shear), has been shown in Jaffe et al. (2005, ApJ, 629, L1) to correlate unexpectedly with the WMAP first-year data. Aims. We re-assess the signature of this model in the WMAP 3-year data. Methods. The cross-correlation methods are described in Jaffe et al. (2006a, ApJ, 643, 616). We use the WMAP 3-year data release, including maps for individual years, and perform additional comparisons to assess the influence of both noise and residual foregrounds and eliminate potential non-cosmological sources for the correlation. Results. We confirm that the signal is detected in both the combined 3-year data and the individual yearly sky maps at a level consistent with our original analysis. The significance of the correlation is not affected by either noise or foreground residuals. Conclusions. The results of our previous study are unchanged. C1 Max Planck Inst Astrophys, D-85741 Garching, Germany. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Univ Oslo, Ctr Math Applicat, N-0316 Oslo, Norway. CALTECH, Pasadena, CA 91125 USA. Univ Warsaw Observ, PL-00478 Warsaw, Poland. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jaffe, TR (reprint author), Max Planck Inst Astrophys, Karl Schwarzschild Str 1,Postfach 1317, D-85741 Garching, Germany. EM tjaffe@mpa-garching.mpg.de; banday@mpa-garching.mpg.de; h.k.k.eriksen@astro.uio.no; Krzysztof.M.Gorski@jpl.nasa.gov; f.k.hansen@astro.uio.no NR 21 TC 42 Z9 43 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2006 VL 460 IS 2 BP 393 EP 396 DI 10.1051/0004-6361:20065748 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 110HW UT WOS:000242370100015 ER PT J AU Gruszecki, M Murawski, K Selwa, M Ofman, L AF Gruszecki, M. Murawski, K. Selwa, M. Ofman, L. TI Numerical simulations of vertical oscillations of a multi-stranded coronal loop SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE magnetohydrodynamics (MHD); Sun : corona; methods : numerical ID FAST MAGNETOHYDRODYNAMIC OSCILLATIONS; FAST MAGNETOACOUSTIC WAVES; TRANSVERSE OSCILLATIONS; TRANSITION-REGION; ARCADE; TRACE; PROPAGATION; ELEMENTARY; EXPLORER; MODES AB Aims. We consider impulsively generated oscillations in a 2D model of a curved solar coronal arcade loop that consists of up to 5 strands of dense plasma. Methods. First we do a simulation for a loop which consists of two curved strands. We evaluate by means of numerical simulations the influence of the distance between the strands and their number on wave period, attenuation time, and amplitudes of standing kink waves. Results. The results of the numerical simulations reveal that only strands which are very close to each other (distance comparable to the strand width) considerably change the collective behavior of kink oscillations. More distant strands also exhibit weak coupling of the oscillations. However, their behavior can essentially be explained in terms of separate oscillating loops. We compare the numerical results with recent TRACE observational findings, and find qualitative agreement. C1 Marie Curie Sklodowska Univ, Inst Phys, Grp Astrophys & Grav Theory, PL-20031 Lublin, Poland. NASA, Goddard Space Flight Ctr, Catholic Univ Amer, Greenbelt, MD 20771 USA. RP Gruszecki, M (reprint author), Marie Curie Sklodowska Univ, Inst Phys, Grp Astrophys & Grav Theory, Ul Radziszewskiego 10, PL-20031 Lublin, Poland. EM marcingruszecki@wp.pl NR 38 TC 21 Z9 21 U1 0 U2 3 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2006 VL 460 IS 3 BP 887 EP 892 DI 10.1051/0004-6361:20065426 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 114GX UT WOS:000242655800028 ER PT J AU Muller, DAN Schlichenmaier, R Fritz, G Beck, C AF Muller, D. A. N. Schlichenmaier, R. Fritz, G. Beck, C. TI The multi-component field topology of sunspot penumbrae - A diagnostic tool for spectropolarimetric measurements SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE Sun : sunspots; Sun : photosphere; Sun : magnetic fields; Sun : atmosphere; Sun : infrared ID BAND CIRCULAR-POLARIZATION; MAGNETIC-FLUX TUBES; FINE-STRUCTURE; SPECTRAL SIGNATURE; VELOCITY; LINES; CALIBRATION; MODEL AB Context. Sunspot penumbrae harbor highly structured magnetic fields and flows. The moving flux tube model offers an explanation for several observed phenomena, e.g. the Evershed effect and bright penumbral grains. Aims. A wealth of information can be extracted from spectropolarimetric observations. In order to deduce the structure of the magnetic field in sunspot penumbrae, detailed forward modeling is necessary. On the one hand, it gives insight into the sensitivity of various spectral lines to different physical scenarios. On the other hand, it is a very useful tool to guide inversion techniques. In this work, we present a generalized 3D geometrical model that embeds an arbitrarily shaped flux tube in a stratified magnetized atmosphere. Methods. The new semi-analytical geometric model serves as a frontend for a polarized radiative transfer code. The advantage of this model is that it preserves the discontinuities of the physical parameters across the flux tube boundaries. This is important for the detailed shape of the emerging Stokes Profiles and the resulting net circular polarization (NCP). Results. (a) The inclination of downflows in the outer penumbra must be shallower than approximately 15 degrees; (b) observing the limbside NCP of sunspots in the Fe I 1564.8 nm line offers a promising way to identify a reduced magnetic field strength in flow channels; (c) the choice of the background atmosphere can significantly influence the shape of the Stokes profiles, but does not change the global characteristics of the resulting NCP curves for the tested atmospheric models. C1 NASA, Goddard Space Flight Ctr, European Space Agcy, Res & Sci Support Dept, Greenbelt, MD 20771 USA. Kiepenheuer Inst Sonnenphys, D-79104 Freiburg, Germany. Arnold Sommerfeld Ctr Theoret Phys, D-80333 Munich, Germany. RP Muller, DAN (reprint author), NASA, Goddard Space Flight Ctr, European Space Agcy, Res & Sci Support Dept, Mail Code 612-5, Greenbelt, MD 20771 USA. EM dmueller@esa.nascom.nasa.gov; schliche@kis.uni-freiburg.de; derfritz@gmx.net; cbeck@kis.uni-freiburg.de RI Fritz, Georg/F-3910-2010 OI Fritz, Georg/0000-0002-1503-9165 NR 23 TC 17 Z9 17 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2006 VL 460 IS 3 BP 925 EP U167 DI 10.1051/0004-6361:20066062 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 114GX UT WOS:000242655800032 ER PT J AU Raiteri, CM Villata, M Kadler, M Ibrahimov, MA Kurtanidze, OM Larionov, VM Tornikoski, M Boltwood, P Lee, CU Aller, MF Romero, GE Aller, HD Araudo, AT Arkharov, AA Bach, U Barnaby, D Berdyugin, A Buemi, CS Carini, MT Carosati, D Cellone, SA Cool, R Dolci, M Efimova, NV Fuhrmann, L Hagen-Thorn, VA Holcomb, M Ilyin, I Impellizzeri, V Ivanidze, RZ Kapanadze, BZ Kerp, J Konstantinova, TS Kovalev, YY Kovalev, YA Kraus, A Krichbaum, TP Lahteenmaki, A Lanteri, L Leto, P Lindfors, E Mattox, JR Napoleone, N Nikolashvili, MG Nilsson, K Ohlert, J Papadakis, IE Pasanen, M Poteet, C Pursimo, T Ros, E Sigua, LA Smith, S Takalo, LO Trigilio, C Troller, M Umana, G Ungerechts, H Walters, R Witzel, A Xilouris, E AF Raiteri, C. M. Villata, M. Kadler, M. Ibrahimov, M. A. Kurtanidze, O. M. Larionov, V. M. Tornikoski, M. Boltwood, P. Lee, C. -U. Aller, M. F. Romero, G. E. Aller, H. D. Araudo, A. T. Arkharov, A. A. Bach, U. Barnaby, D. Berdyugin, A. Buemi, C. S. Carini, M. T. Carosati, D. Cellone, S. A. Cool, R. Dolci, M. Efimova, N. V. Fuhrmann, L. Hagen-Thorn, V. A. Holcomb, M. Ilyin, I. Impellizzeri, V. Ivanidze, R. Z. Kapanadze, B. Z. Kerp, J. Konstantinova, T. S. Kovalev, Y. Y. Kovalev, Yu. A. Kraus, A. Krichbaum, T. P. Lahteenmaki, A. Lanteri, L. Leto, P. Lindfors, E. Mattox, J. R. Napoleone, N. Nikolashvili, M. G. Nilsson, K. Ohlert, J. Papadakis, I. E. Pasanen, M. Poteet, C. Pursimo, T. Ros, E. Sigua, L. A. Smith, S. Takalo, L. O. Trigilio, C. Troller, M. Umana, G. Ungerechts, H. Walters, R. Witzel, A. Xilouris, E. TI Multifrequency variability of the blazar AO 0235+164 - The WEBT campaign in 2004-2005 and long-term SED analysis SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; galaxies : BL Lacertae objects : general; galaxies : BL Lacertae objects : individual : AO 0235+164; galaxies : jets; galaxies : quasars : general ID ACTIVE GALACTIC NUCLEI; BL-LACERTAE OBJECTS; EXTRAGALACTIC RADIO-SOURCES; XMM-NEWTON OBSERVATIONS; SOFT-X-RAY; RELATIVISTIC JETS; LIGHT CURVES; HELICAL JETS; QUASARS; AO-0235+164 AB Aims. A huge multiwavelength campaign targeting the blazar AO0235+164 was organized by the Whole Earth Blazar Telescope (WEBT) in 2003 - 2005 to study the variability properties of the source. Methods. Monitoring observations were carried out at cm and mm wavelengths, and in the near-IR and optical bands, while three pointings by the XMM-Newton satellite provided information on the X-ray and UV emission. Results. We present the data acquired during the second observing season, 2004 - 2005, by 27 radio-to-optical telescopes. The similar to 2600 data points collected allow us to trace the low-energy behaviour of the source in detail, revealing an increased near-IR and optical activity with respect to the previous season. Increased variability is also found at the higher radio frequencies, down to similar to 15 GHz, but not at the lower ones. While the X-ray (and optical) light curves obtained during the XMM-Newton pointings reveal no significant short-term variability, the simultaneous intraday radio observations with the 100 m telescope at Effelsberg show flux-density changes at 10.5 GHz, which are more likely due to a combination of intrinsic and extrinsic processes. Conclusions. The radio ( and optical) outburst predicted to peak around February - March 2004 on the basis of the previously observed 5 - 6 yr quasi-periodicity did not occur. The analysis of the optical light curves reveals now a longer characteristic time scale of variability of similar to 8 yr, which is also present in the radio data. The spectral energy distributions corresponding to the XMM-Newton observations performed during the WEBT campaign are compared with those pertaining to previous pointings of X-ray satellites. Bright, soft X-ray spectra can be described in terms of an extra component, which appears also when the source is faint through a hard UV spectrum and a curvature of the X-ray spectrum. Finally, there might be a correlation between the X-ray and optical bright states with a long time delay of about 5 yr, which would require a geometrical interpretation. C1 Osserv Astron Torino, INAF, I-10025 Pino Torinese, Italy. Max Planck Inst Radioastron, D-53121 Bonn, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Uzbek Acad Sci, Ulugh Beg Astron Inst, Tashkent 700052, Uzbekistan. Abastumani Observ, GE-383762 Abastumani, Rep of Georgia. St Petersburg State Univ, Astron Inst, St Petersburg 198504, Russia. Helsinki Univ Technol, Metsahovi Radio Observ, FIN-02540 Kylmala, Finland. Korea Astron & Space Sci Inst, Seoul, South Korea. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Inst Argentino Radioastron, RA-1894 Villa Elisa, Argentina. UNLP, Fac Ciencias Astron & Geofis, La Plata, Buenos Aires, Argentina. Pulkovo Observ, St Petersburg, Russia. Western Kentucky Univ, Dept Phys & Astron, Bowling Green, KY USA. Tourla Observ, Piikkio 21500, Finland. Osserv Astrofis Catania, INAF, I-95123 Catania, Italy. Armenzano Astron Observ, Assisi, Italy. Steward Observ, Tucson, AZ 85721 USA. Osservatorio Astron Collurania, INAF, I-64100 Teramo, Italy. Univ Perugia, Dipartimento Fis, I-06100 Perugia, Italy. Univ Perugia, Osservatorio Astron, I-06100 Perugia, Italy. AStrophys Inst Potsdam, D-14482 Potsdam, Germany. Univ Bonn, Argelander Inst Astron, D-53121 Bonn, Germany. Natl Radio Astron Observ, Green Bank, WV 24944 USA. Astro Space Ctr Lebedev Phys Inst, Moscow 117997, Russia. Ist Radioastron, INAF, I-96017 Noto, Italy. Fayetteville State Univ, Dept Nat Sci, Fayetteville, NC 28301 USA. Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. Michael Adrian Observ, D-65468 Trebur, Germany. FORTH, IESL, GR-71110 Iraklion, Greece. Univ Crete, Dept Phys, GR-71003 Iraklion, Greece. Nord Opt Telescope, Santa Cruz de La Palma 38700, Spain. Tbilisi State Univ, Akhaltsikhe Branch, GE-380086 Tbilisi, Rep of Georgia. IRAM, E-18012 Granada, Spain. Natl Observ Athens, Inst Astron & Astrophys, GR-11810 Athens, Greece. RP Raiteri, CM (reprint author), Osserv Astron Torino, INAF, I-10025 Pino Torinese, Italy. EM villata@to.astro.it RI Papadakis, Iossif/C-3235-2011; Larionov, Valeri/H-1349-2013; Efimova, Natalia/I-2196-2013; Xilouris, Emmanuel/K-9459-2013; Kovalev, Yuri/J-5671-2013; Lahteenmaki, Anne/L-5987-2013; Kurtanidze, Omar/J-6237-2014; Kovalev, Yuri/N-1053-2015; Grishina, Tatiana/H-6873-2013; Hagen-Thorn, Vladimir/H-3983-2013; OI Larionov, Valeri/0000-0002-4640-4356; Efimova, Natalia/0000-0002-8071-4753; Kovalev, Yuri/0000-0001-9303-3263; Grishina, Tatiana/0000-0002-3953-6676; Hagen-Thorn, Vladimir/0000-0002-6431-8590; Leto, Paolo/0000-0003-4864-2806; Villata, Massimo/0000-0003-1743-6946; Raiteri, Claudia Maria/0000-0003-1784-2784 NR 50 TC 49 Z9 51 U1 0 U2 2 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2006 VL 459 IS 3 BP 731 EP 743 DI 10.1051/0004-6361:20065744 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 108YW UT WOS:000242276100006 ER PT J AU Ederoclite, A Mason, E Della Valle, M Gilmozzi, R Williams, RE Germany, L Saviane, I Matteucci, F Schaefer, BE Walter, F Rudy, RJ Lynch, D Mazuk, S Venturini, CC Puetter, RC Perry, RB Liller, W Rotter, A AF Ederoclite, A. Mason, E. Della Valle, M. Gilmozzi, R. Williams, R. E. Germany, L. Saviane, I. Matteucci, F. Schaefer, B. E. Walter, F. Rudy, R. J. Lynch, D. Mazuk, S. Venturini, C. C. Puetter, R. C. Perry, R. B. Liller, W. Rotter, A. TI Early spectral evolution of nova sagittarii 2004 (V5114 Sagittarii) SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : novae, cataclysmic variables; stars : individual : V5114 Sgr ID INFRARED-EMISSION; SPECTROSCOPY; DISTANCE; LINES AB Aims. We present optical and near-infrared spectral evolution of the Galactic nova V5114 Sgr (2004) during few months after the outburst. Methods. We use multi-band photometry and line intensities derived from spectroscopy to put constrains on the distance and the physical conditions of the ejecta of V5114 Sgr. Results. The nova showed a fast decline (t(2) similar or equal to 11 days) and spectral features of Fe II spectroscopic class. It reached M-V = -8.7 +/- 0.2 mag at maximum light, from which we derive a distance of 7700 +/- 700 kpc and a distance from the galactic plane of about 800 pc. Hydrogen and oxygen mass of the ejecta are measured from emission lines, leading to similar to 10(-6) and 10(-7) M-circle dot, respectively. We compute the filling factor of the ejecta to be in the range 0.1-10(-3). We found the value of the filling factor to decrease with time. The same is also observed in other novae, then giving support to the idea that nova shells are not homogeneously filled in, rather being the material clumped in relatively higher density blobs less affected by the general expanding motion of the ejecta. C1 Vrije Univ Brussel, Brussels, Belgium. ESO, Santiago 91001, Chile. Univ Trieste, Dept Astron, Trieste, Italy. Osserv Astrofis Arcetri, INAF, I-50125 Florence, Italy. Univ Calif Santa Barbara, Kavli Inst Theoret Phys, Santa Barbara, CA 93106 USA. Space Telescope Sci Inst, Baltimore, MD USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Aerosp Corp, Los Angeles, CA 90009 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Isaac Newton Inst, Santiago, Chile. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. RP Ederoclite, A (reprint author), Vrije Univ Brussel, 2 Pleinlaan, Brussels, Belgium. EM aederocl@vub.ac.be OI mason, elena/0000-0003-3877-0484; Della Valle, Massimo/0000-0003-3142-5020 NR 35 TC 21 Z9 21 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 EI 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2006 VL 459 IS 3 BP 875 EP U39 DI 10.1051/0004-6361:20065741 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 108YW UT WOS:000242276100022 ER PT J AU Werner, M AF Werner, Michael TI Spitzer: the first 30 months SO ASTRONOMY & GEOPHYSICS LA English DT Article ID SPACE-TELESCOPE; BROWN DWARF; PERFORMANCE; DISKS AB Decades of work with ground-based and airborne telescopes, together with the results from the highly successful Infrared Astronomy Satellite (IRAS) and Infrared Space Observatory (ISO), have demonstrated the importance of infrared studies for advancing our understanding of astrophysics. Objects ranging from the chilly fringes of our solar system to the dust-enshrouded nuclei of distant galaxies radiate entirely or predominantly in the infrared band. At the same time, advances in astronomical techniques all across the electromagnetic spectrum have highlighted the importance of multi-spectral approaches in unravelling many astrophysical problems. The launch of the National Aeronautics and Space Administration's Spitzer Space Telescope (Spitzer) in 2003 provided the scientific community with the most powerful tool yet available for astronomical explorations between 3.6 and 160 mu m. Spitzer combines the intrinsic sensitivity of a cryogenic telescope in space with the tremendous imaging and spectroscopic capabilities of the new generation of infrared detector arrays. This paper provides an overview of the unique design and of the Spitzer observatory and discusses several particularly striking scientific results selected to demonstrate the range of Spitzer's capabilities. C1 CALTECH, Astron & Phys Directorate, JPL, Pasadena, CA 91125 USA. RP Werner, M (reprint author), CALTECH, Astron & Phys Directorate, JPL, Pasadena, CA 91125 USA. EM mwerner@sirtfweb.jpl.nasa.gov NR 15 TC 0 Z9 0 U1 0 U2 1 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1366-8781 J9 ASTRON GEOPHYS JI Astron. Geophys. PD DEC PY 2006 VL 47 IS 6 BP 11 EP 16 DI 10.1111/j.1468-4004.2006.47611.x PG 6 WC Astronomy & Astrophysics; Geochemistry & Geophysics SC Astronomy & Astrophysics; Geochemistry & Geophysics GA 107VL UT WOS:000242199000029 ER PT J AU Sephton, MA Howard, LE Bland, PA James, RH Russell, SS Prior, DJ Zolensky, ME AF Sephton, Mark A. Howard, Lauren E. Bland, Phil A. James, Rachael H. Russell, Sara S. Prior, Dave J. Zolensky, Mark E. TI Delving into Allende's dark secrets SO ASTRONOMY & GEOPHYSICS LA English DT Article ID LITHIUM ISOTOPES; INCLUSIONS; VIGARANO; RECORD AB Meteorites such as Allende - type III carbonaceous chondrites - contain strange dark clasts that would have been formed as part of early planet-forming processes in the early solar system. Opinion has been divided for years on the provenance of these components. Formation of source materials in the protoplanetary disc, impact-induced fragmentation of the parent asteroid or complex aqueous and thermal histories have all been suggested. We describe new analytical approaches that have cast light on these dark objects and their origins. C1 Univ London Imperial Coll Sci Technol & Med, Impacts & Astromat Res Ctr, Dept Earth Sci & Engn, London, England. Open Univ, Dept Earth Sci, Milton Keynes MK7 6AA, Bucks, England. Nat Hist Museum, Impacts & Astromat Res Ctr, London SW7 5BD, England. Univ Liverpool, Dept Earth & Ocean Sci, Liverpool L69 3BX, Merseyside, England. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Sephton, MA (reprint author), Univ London Imperial Coll Sci Technol & Med, Impacts & Astromat Res Ctr, Dept Earth Sci & Engn, London, England. RI James, Rachael/G-8613-2011; OI Sephton, Mark/0000-0002-2190-5402 NR 12 TC 0 Z9 0 U1 0 U2 3 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1366-8781 J9 ASTRON GEOPHYS JI Astron. Geophys. PD DEC PY 2006 VL 47 IS 6 BP 37 EP 38 DI 10.1111/j.1468-4004.2006.47637.x PG 2 WC Astronomy & Astrophysics; Geochemistry & Geophysics SC Astronomy & Astrophysics; Geochemistry & Geophysics GA 107VL UT WOS:000242199000036 ER PT J AU LaRoque, SJ Bonamente, M Carlstrom, JE Joy, MK Nagai, D Reese, ED Dawson, KS AF LaRoque, Samuel J. Bonamente, Massimiliano Carlstrom, John E. Joy, Marshall K. Nagai, Daisuke Reese, Erik D. Dawson, Kyle S. TI X-ray and Sunyaev-Zel'dovich effect measurements of the gas mass fraction in galaxy clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmological parameters; cosmology : observations; X-rays : galaxies : clusters ID MEDIUM-SENSITIVITY SURVEY; COSMIC DISTANCE SCALE; INTRACLUSTER MEDIUM; HUBBLE CONSTANT; CHANDRA OBSERVATIONS; HOT PLASMA; CONSTRAINTS; REDSHIFT; TEMPERATURE; COSMOLOGY AB We present gas mass fractions of 38 massive galaxy clusters at redshifts 0.14 <= z <= 0.89, derived from Chandra X-ray and OVRO/BIMA interferometric Sunyaev-Zel'dovich effect (SZE) measurements. We use three models for the gas distribution: (1) an isothermal beta-model fit jointly to the X-ray data at radii beyond 100 kpc and to all of the SZE data, (2) a nonisothermal double beta-model in hydrostatic equilibrium with a Navarro-Frenk-White (NFW) dark matter distribution, fit jointly to all of the X-ray and SZE data, and (3) an isothermal beta-model fit only to the SZE spatial data. We show that the isothermal model well characterizes the intracluster medium outside the cluster core and provides good fits to clusters with a range of morphological properties. X-ray and SZE mean gas mass fractions for model 1 are f(gas)(X-ray) = 0.110 +/- 0.003(-0:018)(+0.006) and f(gas)(SZE) = 0.116 +/- 0.005(-0.026)(+0.009) assuming (Omega(M); Omega(Lambda); h) = (0.3; 0.7; 0.7); uncertainties are statistical followed by systematic at 68% confidence. For model 2, f(gas)(X-ray) 0.119 +/- 0.003(-0.014)(+0.007) and f(gas)(SZE) = 0.121 +/- 0.005(-0.016)(+0.009). For model 3, f(gas)(SZE) 0.120 +/- 0.009(-0.027)(+0.009). The agreement in the results shows that the core can be accounted for satisfactorily by either excluding it from fits to the X-ray data or modeling the intracluster gas with a nonisothermal double beta-model. We find that the SZE is largely insensitive to core structure. Our results indicate that the ratio of gas mass fraction within r(2500) to the cosmic baryon fraction, f(gas)/(Omega(B)/Omega(M)) , is 0.68(-0.16)(+0.10) , where statistical and systematic uncertainties are included at 68% confidence. By assuming that cluster gas mass fractions are independent of redshift, we find that the results agree with standard Lambda CDM cosmology and are inconsistent with a flat matter-dominated (Omega(M) = 1) universe. C1 Univ Chicago, Dept Astron & Astrophys, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA. Univ Alabama, Dept Phys, Huntsville, AL 35812 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Chicago, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP LaRoque, SJ (reprint author), Univ Chicago, Dept Astron & Astrophys, Kavli Inst Cosmol Phys, 5640 S Ellis Ave, Chicago, IL 60637 USA. NR 97 TC 133 Z9 133 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 917 EP 936 DI 10.1086/508139 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100008 ER PT J AU Watson, D Fynbo, JPU Ledoux, C Vreeswijk, P Hjorth, J Smette, A Andersen, AC Aoki, K Augusteijn, T Beardmore, AP Bersier, D Ceron, JMC D'Avanzo, P Diaz-Fraile, D Gorosabel, J Hirst, P Jakobsson, P Jensen, BL Kawai, N Kosugi, G Laursen, P Levan, A Masegosa, J Naranen, J Page, KL Pedersen, K Pozanenko, A Reeves, JN Rumyantsev, V Shahbaz, T Sharapov, D Sollerman, J Starling, RLC Tanvir, N Torstensson, K Wiersema, K AF Watson, D. Fynbo, J. P. U. Ledoux, C. Vreeswijk, P. Hjorth, J. Smette, A. Andersen, A. C. Aoki, K. Augusteijn, T. Beardmore, A. P. Bersier, D. Ceron, J. M. Castro D'Avanzo, P. Diaz-Fraile, D. Gorosabel, J. Hirst, P. Jakobsson, P. Jensen, B. L. Kawai, N. Kosugi, G. Laursen, P. Levan, A. Masegosa, J. Naranen, J. Page, K. L. Pedersen, K. Pozanenko, A. Reeves, J. N. Rumyantsev, V. Shahbaz, T. Sharapov, D. Sollerman, J. Starling, R. L. C. Tanvir, N. Torstensson, K. Wiersema, K. TI A log N-HI=22.6 damped Ly alpha absorber in a dark gamma-ray burst: The environment of GRB 050401 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; galaxies : high-redshift; galaxies : ISM; gamma rays : bursts; quasars : absorption lines; X-rays : general ID HIGH COLUMN DENSITY; HOST GALAXIES; LYMAN-ALPHA; LOW METALLICITY; INTERSTELLAR-MEDIUM; ABSORPTION SYSTEMS; DUST PROPERTIES; STAR-FORMATION; LOW-REDSHIFT; NEUTRAL GAS AB The optical afterglow spectrum of GRB 050401 (at z = 2.8992 +/- 0.0004) shows the presence of a damped Ly alpha absorber (DLA), with log N-Hi 22.6 +/- 0.3. This is the highest column density ever observed in a DLA and is about 5 times larger than the strongest DLA detected so far in any QSO spectrum. From the optical spectrum, we also find a very large Zn column density, implying an abundance of [Zn/H] = -1.0 +/- 0.4. These large columns are supported by the early X-ray spectrum from Swift XRT, which shows a column density (in excess of Galactic) of log N-H = 22.21(-0.08)(+0.06) assuming solar abundances (at z = 2.9). The comparison of this X-ray column density, which is dominated by absorption due to alpha-chain elements, and the H I column density derived from the Ly alpha absorption line allows us to derive a metallicity for the absorbing matter of [alpha/H] = -0.4 +/- 0.3. The optical spectrum is reddened and can be well reproduced with a power law with SMC extinction, where A(V) = 0.62 +/- 0.06. But the total optical extinction can also be constrained independent of the shape of the extinction curve: from the optical to X-ray spectral energy distribution, we find 0.5 less than or similar to A(V) less than or similar to 4.5. However, even this upper limit, independent of the shape of the extinction curve, is still well below the dust column that is inferred from the X-ray column density, i.e., A(V) = 9.1(-1.5)(+1.4). This discrepancy might be explained by a small dust content with high metallicity (low dust-to-metals ratio). "Gray" extinction cannot explain the discrepancy, since we are comparing the metallicity to a measurement of the total extinction (without reference to the reddening). Little dust with high metallicity may be produced by sublimation of dust grains or may naturally exist in systems younger than a few hundred megayears. C1 Univ Copenhagen, Niels Bohr Inst, Dark Cosmol Ctr, DK-2100 Copenhagen O, Denmark. European So Observ, Santiago 19, Chile. Natl Astron Observ, Subaru Telescope, Hilo, HI 96720 USA. Nord Opt Telescope, La Palma, Spain. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. Osserv Astron Brera, INAF, I-23807 Merate, LC, Italy. Univ Insubria, Dipartimento Matemat & Fis, I-22100 Como, Italy. CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain. Joint Astron Ctr, Hilo, HI 96720 USA. Tokyo Inst Technol, Dept Phys, Tokyo 1528551, Japan. ALMA Project Off, Natl Astron Observ, Mitaka, Tokyo 1818588, Japan. Univ Hertfordshire, Ctr Astrophys Res, Hatfield AL10 9AB, Herts, England. IKI, Inst Space Res, Moscow 117997, Russia. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Spain. Ulugh Beg Astron Inst, Tashkent 700052, Uzbekistan. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. RP Watson, D (reprint author), Univ Copenhagen, Niels Bohr Inst, Dark Cosmol Ctr, Juliane Maries Vej 30, DK-2100 Copenhagen O, Denmark. EM darach@astro.ku.dk RI Fynbo, Johan/L-8496-2014; Hjorth, Jens/M-5787-2014; Watson, Darach/E-4521-2015; Jensen, Brian Lindgren/E-1275-2015; Jakobsson, Pall/L-9950-2015; OI Fynbo, Johan/0000-0002-8149-8298; Hjorth, Jens/0000-0002-4571-2306; Watson, Darach/0000-0002-4465-8264; Jensen, Brian Lindgren/0000-0002-0906-9771; Jakobsson, Pall/0000-0002-9404-5650; Masegosa, J./0000-0002-3170-4137 NR 66 TC 99 Z9 100 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1011 EP 1019 DI 10.1086/508049 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100015 ER PT J AU Kim, DW Fabbiano, G Kalogera, V King, AR Pellegrini, S Trinchieri, G Zepf, SE Zezas, A Angelini, L Davies, RL Gallagher, JS AF Kim, D. -W. Fabbiano, G. Kalogera, V. King, A. R. Pellegrini, S. Trinchieri, G. Zepf, S. E. Zezas, A. Angelini, L. Davies, R. L. Gallagher, J. S. TI Probing the low-luminosity X-ray luminosity function in normal elliptical galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : elliptical and lenticular, cD; X-rays : binaries; X-rays : galaxies ID CHANDRA MULTIWAVELENGTH PROJECT; GLOBULAR CLUSTER CONNECTION; LOW-MASS; POINT-SOURCE; CENTAURUS-A; ULTRACOMPACT BINARIES; POPULATION; FIELD; M31; NGC-4472 AB We present the first low-luminosity [L-X > (5-10) x 10(36) ergs s(-1)] X-ray luminosity functions (XLFs) of low-mass X-ray binaries (LMXBs) determined for two typical old elliptical galaxies, NGC 3379 and NGC 4278. Because both galaxies contain little diffuse emission from hot ISM and no recent significant star formation (hence no high-mass X-ray binary contamination), they provide two of the best homogeneous sample of LMXBs. With 110 and 140 ks Chandra ACIS S3 exposures, we detect 59 and 112 LMXBs within the D-25 ellipses of NGC 3379 and NGC 4278, respectively. The resulting XLFs are well represented by a single power law with a slope (in a differential form) of 1.9 +/- 0.1. In NGC 4278, we can exclude the break at L-X similar to 5 x 10(37) ergs s(-1) that was recently suggested as being a general feature of LMXB XLFs. In NGC 3379, on the other hand, we find a localized excess over the power-law XLF at similar to 4 x 10(37) ergs s(-1), but with a marginal significance of similar to 1.6 sigma. Because of the small number of luminous sources, we cannot constrain the high-luminosity break (at 5 x 10(38) ergs s(-1)) found in a large sample of early- type galaxies. For our two galaxies, the ratios of the integrated LMXB X-ray luminosities to the optical luminosities differ by a factor of 4, but are consistent with the general trend of a positive correlation between the X-ray-to-optical luminosity ratio and the globular cluster specific frequency. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. Univ Leicester, Leicester LE1 7RH, Leics, England. Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy. Osserv Astron Brera, INAF, I-20121 Milan, Italy. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Oxford, Oxford OX1 3RH, England. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. RP Kim, DW (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM kim@cfa.harvard.edu; gfabbiano@cfa.harvard.edu; vicky@northwestern.edu; ark@star.le.ac.uk; silvia.pellegrini@unibo.it; ginevra.trinchieri@brera.inaf.it; zepf@pa.msu.edu; azezas@cfa.harvard.edu; angelini@davide.gsfc.nasa.gov; rld@astro.ox.ac.uk; jsg@astro.wisc.edu RI Zezas, Andreas/C-7543-2011 OI Zezas, Andreas/0000-0001-8952-676X NR 45 TC 26 Z9 26 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1090 EP 1096 DI 10.1086/508415 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100024 ER PT J AU Regan, MW Thornley, MD Vogel, SN Sheth, K Draine, BT Hollenbach, DJ Meyer, M Dale, DA Engelbracht, CW Kennicutt, RC Armus, L Buckalew, B Calzetti, D Gordon, KD Helou, G Leitherer, C Malhotra, S Murphy, E Rieke, GH Rieke, MJ Smith, JD AF Regan, Michael W. Thornley, Michele D. Vogel, Stuart N. Sheth, Kartik Draine, Bruce T. Hollenbach, David J. Meyer, Martin Dale, Daniel A. Engelbracht, Charles W. Kennicutt, Robert C. Armus, Lee Buckalew, Brent Calzetti, Daniela Gordon, Karl D. Helou, George Leitherer, Claus Malhotra, Sangeeta Murphy, Eric Rieke, George H. Rieke, Marcia J. Smith, J. D. TI The radial distribution of the interstellar medium in disk galaxies: Evidence for secular evolution SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; galaxies : individual (NGC 628, NGC 3351, NGC 3521, NGC 3627, NGC 4321, NGC 4736, NGC 4826, NGC 5055, NGC 5194, NGC 6946, NGC 7331); galaxies : ISM; galaxies : structure; infrared : galaxies ID HUBBLE-SPACE-TELESCOPE; SCALE KEY PROJECT; NEARBY GALAXIES; STAR-FORMATION; MOLECULAR GAS; SPIRAL GALAXIES; GALACTIC DISKS; BIMA SURVEY; CO; DISTANCE AB One possible way for spiral galaxies to internally evolve would be for gas to flow to the center and form stars in a central disk (pseudo-bulge). If the inflow rate is faster than the rate of star formation, a central concentration of gas will form. In this paper we present radial profiles of stellar and 8 mu m emission from polycyclic aromatic hydrocarbons (PAHs) for 11 spiral galaxies to investigate whether the interstellar medium in these galaxies contains a central concentration above that expected from the exponential disk. In general, we find that the two-dimensional CO and PAH emission morphologies are similar, and that they exhibit similar radial profiles. We find that in 6 of the 11 galaxies there is a central excess in the 8 mu m and CO emission above the inward extrapolation of an exponential disk. In particular, all four barred galaxies in the sample have strong central excesses in both 8 mu m and CO emission. These correlations suggest that the excess seen in the CO profiles is, in general, not simply due to a radial increase in the CO emissivity. In the inner disk, the ratio of the stellar to the 8 mu m radial surface brightness is similar for 9 of the 11 galaxies, suggesting a physical connection between the average stellar surface brightness and the average gas surface brightness at a given radius. We also find that the ratio of the CO to 8 mu m PAH surface brightness is consistent over the sample, implying that the 8 mu m PAH surface brightness can be used as an approximate tracer of the interstellar medium. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Bucknell Univ, Dept Phys & Astron, Lewisburg, PA 17837 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. CALTECH, Ctr Space Sci, Pasadena, CA 91125 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Pasadena, CA 91101 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. RP Regan, MW (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM mregan@stsci.edu OI Draine, Bruce/0000-0002-0846-936X NR 36 TC 40 Z9 40 U1 0 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1112 EP 1121 DI 10.1086/505382 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100026 ER PT J AU Cannon, JM Walter, F Armus, L Bendo, GJ Calzetti, D Draine, BT Engelbracht, CW Helou, G Kennicutt, RC Leitherer, C Roussel, H Bot, C Buckalew, BA Dale, DA de Blok, WJG Gordon, KD Hollenbach, DJ Jarrett, TH Meyer, MJ Murphy, EJ Sheth, K Thornley, MD AF Cannon, John M. Walter, Fabian Armus, Lee Bendo, George J. Calzetti, Daniela Draine, Bruce T. Engelbracht, Charles W. Helou, George Kennicutt, Robert C., Jr. Leitherer, Claus Roussel, Helene Bot, Caroline Buckalew, Brent A. Dale, Daniel A. de Blok, W. J. G. Gordon, Karl D. Hollenbach, David J. Jarrett, Thomas H. Meyer, Martin J. Murphy, Eric J. Sheth, Kartik Thornley, Michele D. TI The nature of infrared emission in the Local Group dwarf galaxy NGC 6822 as revealed by Spitzer SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : dwarf; galaxies : individual ( NGC 6822); galaxies : irregular; galaxies : ISM; infrared : galaxies ID STAR-FORMING GALAXIES; SPECTRAL ENERGY-DISTRIBUTION; H-II-REGIONS; MULTIBAND IMAGING PHOTOMETER; SMALL-MAGELLANIC-CLOUD; FAINT BLUE GALAXIES; IRREGULAR GALAXIES; NEARBY GALAXIES; INTERSTELLAR-MEDIUM; SPACE-TELESCOPE AB We present Spitzer imaging of the metal-deficient (Z similar or equal to 30% Z circle dot) Local Group dwarf galaxy NGC 6822. On spatial scales of similar to 130 pc, we study the nature of IR, H alpha, H-I, and radio continuum emission. Nebular emission strength correlates with IR surface brightness; however, roughly half of the IR emission is associated with diffuse regions not luminous at H alpha (as found in previous studies). The global ratio of dust to H-I gas in the ISM, while uncertain at the actor of similar to 2 level, is similar to 25 times lower than the global values derived for spiral galaxies using similar modeling techniques; localized ratios of dust to H-I gas are about a factor of 5 higher than the global value in NGC 6822. There are strong variations (factors of similar to 10) in the relative ratios of H alpha and IR flux throughout the central disk; the low dust content of NGC 6822 is likely responsible for the different H alpha/IR ratios compared to those found in more metal-rich environments. The H alpha and IR emission is associated with high column density (greater than or similar to 10(21) cm(-2)) neutral gas. Increases in IR surface brightness appear to be affected by both increased radiation field strength and increased local gas density. Individual regions and the galaxy as a whole fall within the observed scatter of recent high-resolution studies of the radio - far-IR correlation in nearby spiral galaxies; this is likely the result of depleted radio and far-IR emission strengths in the ISM of this dwarf galaxy. C1 Wesleyan Univ, Dept Astron, Middletown, CT 06457 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. CALTECH, Pasadena, CA 91101 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2AZ, England. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Mt Stromlo & Siding Spring Observ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. Bucknell Univ, Dept Phys & Astron, Lewisburg, PA 17837 USA. RP Cannon, JM (reprint author), Wesleyan Univ, Dept Astron, Middletown, CT 06457 USA. EM cannon@astro.wesleyan.edu; walter@mpia.de; lee@ipac.caltech.edu; g.bendo@imperial.ac.uk; calzetti@stsci.edu; draine@astro.princeton.edu; chad@as.arizona.edu; gxh@ipac.caltech.edu; robk@ast.cam.ac.uk; leitherer@stsci.edu; roussel@mpia.de; bot@caltech.edu; brentb@ipac.caltech.edu; ddale@uwyo.edu; edeblok@mso.anu.edu.au; kgordon@as.arizona.edu; hollenba@ism.arc.nasa.gov; jarrett@ipac.caltech.edu; martinm@stsci.edu; murphy@astro.yale.edu; kartik@astro.caltech.edu; mthornle@bucknell.edu OI Draine, Bruce/0000-0002-0846-936X NR 79 TC 33 Z9 33 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1170 EP 1187 DI 10.1086/508341 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100031 ER PT J AU Ryde, F Bjornsson, CI Kaneko, Y Meszaros, P Preece, R Battelino, M AF Ryde, Felix Bjornsson, Claes-Ingvar Kaneko, Yuki Meszaros, Peter Preece, Robert Battelino, Milan TI Gamma-ray burst spectral correlations: Photospheric and injection effects SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; gamma rays : observations; radiation mechanisms : nonthermal ID SYNCHROTRON SHOCK MODEL; PROMPT EMISSION; HIGH-ENERGY; EVOLUTION; PULSES; RADIATION; ACCELERATION; MECHANISMS; ENERGETICS; BEPPOSAX AB We present a physical framework that can account for most of the observed spectral properties of prompt gamma- ray burst emission. This includes the variety of spectral shapes and shape evolutions, and spectral correlations between flux and spectral peaks within bursts, described by Borgonovo & Ryde, and among bursts described by Amati and Ghirlanda. In our proposed model the spectral peak is given by the photospheric emission from a relativistic outflow for which the horizon length is much smaller that the radial width. The observed duration of the thermal flash is given by the radial light- crossing time. This then gives the typical emission site at similar to 10(11) cm with a Lorentz factor of similar to 300. This emission is accompanied by nonthermal emission from dissipation locations outside the photosphere. The relative strengths of these two components depend on injection effects at the central engine, leading to varying relative locations of the saturation and photospheric radii. The total emission can then reproduce the observed variety. The spectral correlations are found by assuming that the amount of energy dissipated depends nonlinearly on the averaged particle density. Besides the spectral correlations, this also gives a description of how the relative strength of the thermal component varies with temperature within a burst. C1 AlbaNova, Stockholm Observ, SE-10691 Stockholm, Sweden. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. NASA, Univ Space Res Assoc, Huntsville, AL 35805 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Alabama, Dept Phys, Natl Space Sci & Technol Ctr, Huntsville, AL 35899 USA. RP Ryde, F (reprint author), AlbaNova, Stockholm Observ, SE-10691 Stockholm, Sweden. OI Preece, Robert/0000-0003-1626-7335 NR 58 TC 43 Z9 43 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1400 EP 1415 DI 10.1086/508410 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100050 ER PT J AU Roming, PWA Schady, P Fox, DB Zhang, B Liang, EW Mason, KO Rol, E Burrows, DN Blustin, AJ Boyd, PT Brown, P Holland, ST McGowan, K Landsman, WB Page, KL Rhoads, JE Rosen, SR Vanden Berk, D Barthelmy, SD Breeveld, AA Cucchiara, A De Pasquale, M Fenimore, EE Gehrels, N Gronwall, C Grupe, D Goad, MR Ivanushkina, M James, C Kennea, JA Kobayashi, S Mangano, V Meszaros, P Morgan, AN Nousek, JA Osborne, JP Palmer, DM Poole, T Still, MD Tagliaferri, G Zane, S AF Roming, Peter W. A. Schady, Patricia Fox, Derek B. Zhang, Bing Liang, Enwei Mason, Keith O. Rol, Evert Burrows, David N. Blustin, Alex J. Boyd, Patricia T. Brown, Peter Holland, Stephen T. McGowan, Katherine Landsman, Wayne B. Page, Kim L. Rhoads, James E. Rosen, Simon R. Vanden Berk, Daniel Barthelmy, Scott D. Breeveld, Alice A. Cucchiara, Antonino De Pasquale, Massimiliano Fenimore, Edward E. Gehrels, Neil Gronwall, Caryl Grupe, Dirk Goad, Michael R. Ivanushkina, Mariya James, Cynthia Kennea, Jamie A. Kobayashi, Shiho Mangano, Vanessa Meszaros, Peter Morgan, Adam N. Nousek, John A. Osborne, Julian P. Palmer, David M. Poole, Tracey Still, Martin D. Tagliaferri, Gianpiero Zane, Silvia TI Very early optical afterglows of gamma-ray bursts: Evidence for relative paucity of detection SO ASTROPHYSICAL JOURNAL LA English DT Review DE gamma rays : bursts ID 28 FEBRUARY 1997; REVERSE SHOCK; RADIO AFTERGLOW; LIGHT-CURVE; SWIFT UVOT; THEORETICAL IMPLICATIONS; ENERGY RESERVOIR; MAGNETIC-FIELDS; DIAGNOSTIC-TOOL; KINETIC-ENERGY AB Very early observations with the Swift satellite of gamma-ray burst (GRB) afterglows reveal that the optical component is not detected in a large number of cases. This is in contrast to the bright optical flashes previously discovered in some GRBs (e. g., GRB 990123 and GRB 021211). Comparisons of the X-ray afterglow flux to the optical afterglow flux and prompt gamma-ray fluence is used to quantify the seemingly deficient optical, and in some cases X-ray, light at these early epochs. This comparison reveals that some of these bursts appear to have higher than normal gamma-ray efficiencies. We discuss possible mechanisms and their feasibility for explaining the apparent lack of early optical emission. The mechanisms considered include, foreground extinction, circumburst absorption, Ly alpha blanketing and absorption due to high-redshift, low-density environments, rapid temporal decay, and intrinsic weakness of the reverse shock. Of these, foreground extinction, circumburst absorption, and high redshift provide the best explanations for most of the nondetections in our sample. There is tentative evidence of suppression of the strong reverse shock emission. This could be because of a Poynting flux-dominated flow or a pure nonrelativistic hydrodynamic reverse shock. C1 Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Brigham Young Univ, Dept Phys & Astron, Provo, UT 84602 USA. Inst Astrofis Spaziale & Fis Cosm, Sez Palermo, INAF, I-90146 Palermo, Italy. Osserv Astron Brera, INAF, I-23807 Merate, Italy. RP Roming, PWA (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. EM roming@astro.psu.edu RI Boyd, Patricia/D-3274-2012; Gehrels, Neil/D-2971-2012; Barthelmy, Scott/D-2943-2012; Lujan Center, LANL/G-4896-2012 OI Tagliaferri, Gianpiero/0000-0003-0121-0723; NR 139 TC 80 Z9 81 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1416 EP 1422 DI 10.1086/508481 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100051 ER PT J AU Contopoulos, I Kazanas, D Christodoulou, DM AF Contopoulos, Ioannis Kazanas, Demosthenes Christodoulou, Dimitris M. TI The cosmic battery revisited SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; MHD; plasmas; stars : magnetic fields ID MAGNETIC-FIELDS; ACCRETION DISKS AB We reinvestigate the generation and accumulation of magnetic flux in optically thin accretion flows around active gravitating objects. The source of the magnetic field is the azimuthal electric current associated with the Poynting-Robertson drag on the electrons of the accreting plasma. This current generates magnetic field loops that open up because of the differential rotation of the flow. We show through simple numerical simulations that what regulates the generation and accumulation of magnetic flux near the center is the value of the plasma conductivity. Although the conductivity is usually considered to be effectively infinite for the fully ionized plasmas expected near the inner edge of accretion disks, the turbulence of those plasmas may actually render them much less conducting due to the presence of anomalous resistivity. We have discovered that if the resistivity is sufficiently high throughout the turbulent disk while it is suppressed inside its inner edge, an interesting steady state process is established: accretion carries and accumulates magnetic flux of one polarity inside the inner edge of the disk, whereas magnetic diffusion releases magnetic flux of the opposite polarity to large distances. In this scenario, magnetic flux of one polarity grows and accumulates at a steady rate in the region inside the inner edge and up to the point of equipartition when it becomes dynamically important. We argue that this inward growth and outward expulsion of oppositely directed magnetic fields that we propose could account for the similar to 30 minute cyclic variability observed in the Galactic microquasar GRS 1915+105. C1 Acad Athens, Res Ctr Astron, GR-11527 Athens, Greece. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Math Methods, Bedford, MA 01730 USA. RP Contopoulos, I (reprint author), Acad Athens, Res Ctr Astron, GR-11527 Athens, Greece. NR 15 TC 19 Z9 19 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1451 EP 1456 DI 10.1086/507600 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100054 ER PT J AU Middleditch, J Marshall, FE Wang, QD Gotthelf, EV Zhang, W AF Middleditch, J. Marshall, F. E. Wang, Q. D. Gotthelf, E. V. Zhang, W. TI Predicting the starquakes in PSR J0537-6910 SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : individual (PSR J0537-6910); stars : neutron; X-rays : stars ID X-RAY PULSAR; LARGE-MAGELLANIC-CLOUD; CRUSTAL PLATE-TECTONICS; RAPIDLY SPINNING PULSARS; POST-GLITCH RELAXATION; NEUTRON-STAR CRUST; VELA PULSAR; CRAB PULSAR; POSTGLITCH RELAXATION; TIMING OBSERVATIONS AB We report on more than 7 yr of monitoring of PSR J0537-6910, the 16 ms pulsar in the LMC, using data acquired with RXTE. During this campaign the pulsar experienced 23 sudden increases in frequency ("glitches") amounting to a total gain of over 6 ppm of rotation frequency superposed on its gradual spin-down of v = -2 x 10(-10) Hz s(-1). The time interval from one glitch to the next obeys a strong linear correlation to the amplitude of the first glitch, with a mean slope of about 400 days ppm(-1) (6.5 days mu Hz(-1)), such that these intervals can be predicted to within a few days, an accuracy that has never before been seen in any other pulsar. There appears to be an upper limit of similar to 40 mu Hz for the size of glitches in all pulsars, with the 1999 April glitch of PSR J0537-6910 the largest so far. The change of its spin-down across the glitches, Delta v, appears to have the same hard lower limit, -1.5 x 10(-13) Hz s(-1), as that observed in all other pulsars. The spin-down continues to increase in the long term, v = -10(-21) Hz s(-2), and thus the timing age of PSR J0537-6910 (-0.5vv(-1)) continues to decrease at a rate of nearly 1 yr every year, consistent with movement of its magnetic moment away from its rotational axis by 1 rad every 10,000 yr, or about 1 m yr(-1). PSR J0537-6910 was likely to have been born as a nearly aligned rotator spinning at 75-80 Hz, with a vertical bar v vertical bar considerably smaller than its current value of 2 x 10(-10) Hz s(-1). Its pulse profile consists of a single pulse that is found to be flat at its peak for at least 0.02 cycles. C1 Los Alamos Natl Lab, Comp Computat & Stat Sci Div, Los Alamos, NM 87545 USA. Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. RP Middleditch, J (reprint author), Los Alamos Natl Lab, Comp Computat & Stat Sci Div, CCS-3,MS B265, Los Alamos, NM 87545 USA. EM jon@lanl.gov; frank.marshall@gsfc.nasa.gov; wqd@astro.umass.edu; eric@astro.columbia.edu; william.w.zhang@nasa.gov NR 100 TC 60 Z9 61 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1531 EP 1546 DI 10.1086/508736 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100062 ER PT J AU Beichman, CA Bryden, G Stapelfeldt, KR Gautier, TN Grogan, K Shao, M Velusamy, T Lawler, SM Blaylock, M Rieke, GH Lunine, JI Fischer, DA Marcy, GW Greaves, JS Wyatt, MC Holland, WS Dent, WRF AF Beichman, C. A. Bryden, G. Stapelfeldt, K. R. Gautier, T. N. Grogan, K. Shao, M. Velusamy, T. Lawler, S. M. Blaylock, M. Rieke, G. H. Lunine, J. I. Fischer, D. A. Marcy, G. W. Greaves, J. S. Wyatt, M. C. Holland, W. S. Dent, W. R. F. TI New debris disks around nearby main-sequence stars: Impact on the direct detection of planets SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; Kuiper Belt ID MULTIBAND IMAGING PHOTOMETER; SOLAR-TYPE STARS; SPITZER-SPACE-TELESCOPE; REDUCTION ALGORITHMS; INFRARED EXCESSES; VEGA PHENOMENON; AGE-DEPENDENCE; KUIPER-BELT; G-DWARFS; F-DWARF AB Using the MIPS instrument on Spitzer, we have searched for infrared excesses around a sample of 82 stars, mostly F, G, and K main-sequence field stars, along with a small number of nearby M stars. These stars were selected for their suitability for future observations by a variety of planet-finding techniques. These observations provide information on the asteroidal and cometary material orbiting these stars, data that can be correlated with any planets that may eventually be found. We have found significant excess 70 mu m emission toward 12 stars. Combined with an earlier study, we find an overall 70 mu m excess detection rate of 13% +/- 3% for mature cool stars. Unlike the trend for planets to be found preferentially toward stars with high metallicity, the incidence of debris disks is uncorrelated with metallicity. By newly identifying four of these stars as having weak 24 mu m excesses (fluxes similar to 10% above the stellar photosphere), we confirm a trend found in earlier studies wherein a weak 24 mu m excess is associated with a strong 70 mu m excess. Interestingly, we find no evidence for debris disks around 23 stars cooler than K1, a result that is bolstered by a lack of excess around any of the 38 K1-M6 stars in two companion surveys. One motivation for this study is the fact that strong zodiacal emission can make it hard or impossible to detect planets directly with future observatories such as the Terrestrial Planet Finder (TPF). The observations reported here exclude a few stars with very high levels of emission, > 1000 times the emission of our zodiacal cloud, from direct planet searches. For the remainder of the sample, we set relatively high limits on dust emission from asteroid belt counterparts. C1 CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. San Francisco State Univ, Dept Phys & Astron, San Francisco, CA 94132 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife, Scotland. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Royal Observ, UK Astron Technol Ctr, Edinburgh EH9 3HJ, Midlothian, Scotland. RP Beichman, CA (reprint author), CALTECH, Michelson Sci Ctr, 770 S Wilson Ave, Pasadena, CA 91125 USA. RI Stapelfeldt, Karl/D-2721-2012; OI Fischer, Debra/0000-0003-2221-0861 NR 84 TC 126 Z9 126 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1674 EP 1693 DI 10.1086/508449 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100072 ER PT J AU D'Angelo, G Lubow, SH Bate, MR AF D'Angelo, Gennaro Lubow, Stephen H. Bate, Matthew R. TI Evolution of giant planets in eccentric disks SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; hydrodynamics; methods : numerical planetary; systems : formation ID FORMING JOVIAN PLANETS; DYNAMICAL INSTABILITIES; PROTOPLANET MIGRATION; ORBITAL ECCENTRICITY; TIDAL INTERACTION; ACCRETION DISCS; MHD TURBULENCE; BINARY-SYSTEMS; DENSITY WAVES; MASS PLANETS AB We investigate the interaction between a giant planet and a viscous circumstellar disk by means of high-resolution, two-dimensional hydrodynamic simulations. We consider planetary masses that range from 1 to 3 Jupiter masses (M-J) and initial orbital eccentricities that range from 0 to 0.4. We find that a planet can cause eccentricity growth in a disk region adjacent to the planet's orbit, even if the planet's orbit is circular. Disk-planet interactions lead to growth in a planet's orbital eccentricity. The orbital eccentricities of a 2M(J) and a 3M(J) planet increase from 0 to 0.11 within about 3000 orbits. Over a similar time period, the orbital eccentricity of a 1M(J) planet grows from 0 to 0.02. For a case of a 1MJ planet with an initial eccentricity of 0.01, the orbital eccentricity grows to 0.09 over 4000 orbits. Radial migration is directed inward but slows considerably as a planet's orbit becomes eccentric. If a planet's orbital eccentricity becomes sufficiently large, e greater than or similar to 0.2, migration can reverse and so be directed outward. The accretion rate toward a planet depends on both the disk and the planetary orbital eccentricity and is pulsed over the orbital period. Planetary mass growth rates increase with planetary orbital eccentricity. For e similar to 0.2, the mass growth rate of a planet increases by similar to 30% above the value for e = 0. For e greater than or similar to 0.1, most of the accretion within the planet's Roche lobe occurs when the planet is near the apocenter. Similar accretion modulation occurs for flow at the inner disk boundary, which represents accretion toward the star. C1 Univ Exeter, Sch Phys, Exeter EX4 4QL, Devon, England. NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Moffett Field, CA 94035 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP D'Angelo, G (reprint author), Univ Exeter, Sch Phys, Stocker Rd, Exeter EX4 4QL, Devon, England. EM gdangelo@arc.nasa.gov; lubow@stsci.edu; mbate@astro.ex.ac.uk RI D'Angelo, Gennaro/L-7676-2014 OI D'Angelo, Gennaro/0000-0002-2064-0801 NR 56 TC 70 Z9 71 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1698 EP 1714 DI 10.1086/508451 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100074 ER PT J AU Krall, J St Cyr, OC AF Krall, J. St. Cyr, O. C. TI Flux-rope coronal mass ejection geometry and its relation to observed morphology SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : coronal mass ejections (CMEs) ID ERUPTIVE PROMINENCE; LASCO; EVENT; SUN; STREAMER; MODEL; SOHO; EIT AB A simple parameterization of a three-dimensional flux rope is used to determine a "typical flux-rope geometry" that corresponds to observed flux-rope coronal mass ejection (CME) morphologies (average apparent angular widths) at a leading-edge height of about 5.5 R-circle dot. The parameterized flux rope, the curved axis of which is assumed to trace out an ellipse, is described in terms of the eccentricity of the ellipse, the width (minor diameter d) of the flux rope at the apex, and the height of the apex above the solar surface 2R(1). Assuming self-similar expansion, there are only two geometrical parameters to be determined: the eccentricity is an element of and the axial aspect ratio Lambda(a) equivalent to 2R(1)/d. For each pair of geometrical parameters, an ensemble of 72 orientations is considered, with each being specified in terms of a latitude angle, a longitude angle, and a rotation about the direction of motion. The resulting ensemble of synthetic coronagraph images is used to produce statistical measures of the morphology for comparison to corresponding observational measures from St. Cyr et al. (2004). We find that a typical flux-rope CME has is an element of = 0.7 +/- 0.2 and Lambda(a) 1.1 +/- 0.3. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Solar Phys Branch, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Krall, J (reprint author), USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. NR 30 TC 30 Z9 30 U1 0 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP 1740 EP 1746 DI 10.1086/508337 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MM UT WOS:000242530100079 ER PT J AU Kallivayalil, N Patten, BM Marengo, M Alcock, C Werner, MW Fazio, GG AF Kallivayalil, Nitya Patten, Brian M. Marengo, Massimo Alcock, Charles Werner, Michael W. Fazio, Giovanni G. TI Identification of the microlens in event MACHO-LMC-20 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxy : structure; gravitational lensing; stars : late type ID LARGE-MAGELLANIC-CLOUD; MASSIVE VARIABILITY SURVEYS; LIGHT-CURVE CLASSIFICATION; SPITZER-SPACE-TELESCOPE; ALL-SKY SURVEY; MACHO PROJECT; GALACTIC HALO; MILKY-WAY; PHOTOMETRY; COLORS AB We report on the identification of the lens responsible for microlensing event MACHO-LMC-20. As part of a Spitzer IRAC program conducting mid-infrared follow-up of the MACHO Large Magellanic Cloud microlensing fields, we discovered a significant flux excess at the position of the source star for this event. These data, in combination with high-resolution near-infrared Magellan PANIC data, have allowed us to classify the lens as an early M dwarf in the thick disk of the Milky Way, at a distance of similar to 2 kpc. This is only the second microlens to have been identified, the first also being a M dwarf star in the disk. Together, these two events are still consistent with the expected frequency of nearby stars in the Milky Way thin and thick disks acting as lenses. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91107 USA. RP Kallivayalil, N (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 44 TC 8 Z9 8 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP L97 EP L100 DI 10.1086/510293 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MS UT WOS:000242530700007 ER PT J AU Okajima, T Ebisawa, K Kawaguchi, T AF Okajima, Takashi Ebisawa, Ken Kawaguchi, Toshihiro TI A stellar-mass black hole in the ultraluminous X-ray source M82 X-1? SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; X-rays : individual (M82 X-1) ID NEARBY SPIRAL GALAXIES; HIGH-RESOLUTION CAMERA; ACCRETION DISKS; BINARIES; SPECTRA; CANDIDATES; DISCOVERY; MODEL AB We have analyzed the archival XMM-Newton data of the bright ultraluminous X-ray source M82 X-1 with a 105 ks exposure when the source was in the steady state. Thanks to the high photon statistics from the large effective area and long exposure, we were able to discriminate different X-ray continuum spectral models. Neither the standard accretion disk model [where the radial dependency of the disk effective temperature is T(r) proportional to r(-3/4)] nor a power-law model gives a satisfactory fit. In fact, observed curvature of the M82 X-1 spectrum was just between those of the two models. When the exponent of the radial dependence [p in T(r) proportional to r(-p)] of the disk temperature is allowed to be free, we obtained p = 0.61(-0.02)(+0.03). Such a reduction of p from the standard value 3/4 under extremely high mass accretion rates is predicted from the accretion disk theory as a consequence of the radial energy advection. Thus, the accretion disk in M82 X-1 is considered to be in the slim-disk state, where an optically thick advection-dominated accretion flow is taking place. We have applied a theoretical slim-disk spectral model to M82 X-1 and estimated the black hole mass approximate to 19-32(circle dot). We propose that M82 X-1 is a relatively massive stellar black hole that has been produced through evolution of an extremely massive star, shining at a super-Eddington luminosity by several times the Eddington limit. C1 NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. Aoyama Gakuin Univ, Dept Phys & Math, Sagamihara, Kanagawa 2298558, Japan. RP Okajima, T (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NR 33 TC 24 Z9 24 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2006 VL 652 IS 2 BP L105 EP L108 DI 10.1086/510153 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MS UT WOS:000242530700009 ER PT J AU Kraemer, SB Crenshaw, DM Gabel, JR Kriss, GA Netzer, H Peterson, BM George, IM Gull, TR Hutchings, JB Mushotzky, RF Turner, TJ AF Kraemer, S. B. Crenshaw, D. M. Gabel, J. R. Kriss, G. A. Netzer, H. Peterson, B. M. George, I. M. Gull, T. R. Hutchings, J. B. Mushotzky, R. F. Turner, T. J. TI Simultaneous ultraviolet and X-ray observations of the Seyfert galaxy NGC 4151. II. Physical conditions in the UV absorbers SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : individual (NGC 4151); galaxies : Seyfert; ultraviolet : galaxies ID ACTIVE GALACTIC NUCLEI; NARROW-LINE REGION; SPECTROGRAPH ECHELLE OBSERVATIONS; HUBBLE-SPACE-TELESCOPE; NGC 4151; ABSORPTION-LINES; WARM ABSORBERS; IONIZED-GAS; SPECTRA; VARIABILITY AB We present a detailed analysis, including photoionization modeling, of the intrinsic absorption in the Seyfert 1 galaxy NGC 4151 using ultraviolet (UV) spectra from the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Far Ultraviolet Spectrographic Explorer obtained 2002 May as part of a set of contemporaneous observations that included Chandra High Energy Transmission Grating Spectrometer spectra. In our analysis of the Chandra spectra, we determined that the X-ray absorption was dominated by two components: a high-ionization absorber, revealed by the presence of H-like and He-like lines of Mg, Si, and S, and a lower ionization absorber, in which inner shell absorption lines from lower ionization species of these elements formed. We identified the latter as the source of the saturated UV lines of O VI, C IV, and N V associated with the absorption feature at a radial velocity of similar to-500 km s(-1), which we referred to as component D+E. In the present work, we have derived tighter constrains on the line-of-sight covering factors, densities, and radial distances of the absorbers. We confirm the presence of the three subcomponents of D+E described in our previous paper, with line-of-sight covering factors (C-los) ranging from similar to 0.5 to 0.9, and find evidence for a fourth component, D+Ed, characterized by low ionization and a C-los similar to 0.2. The complexity of the UV absorption in NGC 4151 may be a consequence of the fact that we are viewing the black hole/accretion disk system at a relatively high inclination and, therefore, may be detecting the densest part of the flow. Our deconvolution of the underlying C IV emission indicates that D+E must lie outside the intermediate line region (ILR), hence at a radial distance of similar to 0.1 pc. We find that the equivalent widths (EWs) of the low-ionization lines associated with D+E varied over the period from 1999 July to 2002 May. Although over part of this time, the variations were correlated with changes in the UV continuum, the drop in the EWs of these lines between 2001 April and 2002 May are suggestive of bulk motion of gas out of our line of sight. Over this period, Clos for the low-ionization absorption lines dropped from similar to 0.7 to similar to 0.2. If these lines from these two epochs arose in the same subcomponent, the transverse velocity of the gas is similar to 2100 km s(-1). This is similar to the constraint on transverse velocity derived from the drop in the X-ray absorbing column between 2000 March and 2002 May. Transverse velocities of this order are consistent with an origin in a rotating disk, at the roughly radial distance we derived for D+E. As we suggested in our previous study, it is likely that the absorption arises in a disk-driven wind. C1 Catholic Univ Amer, Inst Astrophys & Computat Sci, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. Univ Colorado, CASA, UCB 389, Boulder, CO 80309 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Tel Aviv Univ, Sch Phys & Astron, Raymond & Beverly Sackler Fac Exact Sci, IL-69978 Tel Aviv, Israel. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Univ Maryland, Dept Phys, Baltimore, MD 21250 USA. Natl Res Council Canada, Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada. RP Kraemer, SB (reprint author), Catholic Univ Amer, Inst Astrophys & Computat Sci, Dept Phys, Washington, DC 20064 USA. EM kraemer@yancey.gsfc.nasa.gov RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 48 TC 34 Z9 34 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2006 VL 167 IS 2 BP 161 EP 176 DI 10.1086/508629 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 112MH UT WOS:000242529600003 ER PT J AU Smith, RK AF Smith, Randall K. TI The chandra X-ray observatory: An astronomical facility available to the world SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 12th United Nations/European-Space-Agency Workshop on Basic Space Science CY MAY 24-28, 2004 CL Beijing, PEOPLES R CHINA SP European Space Agcy DE scientific operations; scientific analysis; science data distribution; X-ray astronomy ID SPECTROMETER; PERFORMANCE AB The Chandra X-ray observatory, one of NASA's "Great Observatories," provides high angular and spectral resolution X-ray data which is freely available to all. In this review I describe the instruments on Chandra along with their current calibration, as well as the Chandra proposal system, the freely-available Chandra analysis software package CIAO, and the Chandra archive. As Chandra is in its 6th year of operation, the archive already contains calibrated observations of a large range of X-ray sources. The Chandra X-ray Center is committed to assisting astronomers from any country who wish to use data from the archive or propose for observations. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. RP Smith, RK (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM rsmith@milkyway.gsfc.nasa.gov NR 6 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0004-640X J9 ASTROPHYS SPACE SCI JI Astrophys. Space Sci. PD DEC PY 2006 VL 305 IS 3 BP 321 EP 324 DI 10.1007/s10509-006-9193-x PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 113NQ UT WOS:000242605000016 ER PT J AU Engel-Cox, JA Hoff, RM Rogers, R Dimmick, F Rush, AC Szykman, JJ Al-Saadi, J Chu, DA Zell, ER AF Engel-Cox, Jill A. Hoff, Raymond M. Rogers, Raymond Dimmick, Fred Rush, Alan C. Szykman, James J. Al-Saadi, Jassim Chu, D. Allen Zell, Erica R. TI Integrating lidar and satellite optical depth with ambient monitoring for 3-dimensional particulate characterization SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE air quality; satellite; MODIS; lidar; particulate matter; policy ID REMOTE-SENSING DATA; AIR-QUALITY; AEROSOL; POLLUTION AB A combination of in-situ PM(2.5), sunphotometers, upward pointing lidar and satellite aerosol optical depth (AOD) instruments have been employed to better understand variability in the correlation between AOD and PM(2.5) at the surface. Previous studies have shown good correlation between these measures, especially in the US east, and encouraged the use of satellite data for spatially interpolating between ground sensors. This work shows that cases of weak correlation can be better understood with knowledge of whether the aerosol is confined to the surface planetary boundary layer (PBL) or aloft. Lidar apportionment of the fraction of aerosol optical depth that is within the PBL can be scaled to give better agreement with surface PM(2.5) than does the total column amount. The study has shown that lidar combined with surface and remotely sensed data might be strategically used to improve our understanding of long-range or regionally transported pollutants in multiple dimensions. (c) 2006 Elsevier Ltd. All rights reserved. C1 Battelle Mem Inst, Arlington, VA 22201 USA. UMBC CREST, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. Univ Maryland, Dept Phys, Baltimore, MD 21250 USA. US EPA, Off Air Qual Planning & Standards, Washington, DC 20460 USA. US EPA, Off Res & Dev, Natl Exposure Res Lab, Res Triangle Pk, NC 27711 USA. US Natl Aeronaut & Space Adm, Langley Res Ctr, Hampton, VA 23681 USA. RP Engel-Cox, JA (reprint author), Battelle Mem Inst, 2101 Wilson Blvd,Suite 800, Arlington, VA 22201 USA. EM engelcoxj@battelle.org RI Hoff, Raymond/C-6747-2012 NR 12 TC 88 Z9 94 U1 4 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD DEC PY 2006 VL 40 IS 40 BP 8056 EP 8067 DI 10.1016/j.atmosenv.2006.02.039 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 120AL UT WOS:000243055600032 ER PT J AU Mukai, S Sano, I Satoh, M Holben, BN AF Mukai, Sonoyo Sano, Itaru Satoh, Mutsumi Holben, Brent N. TI Aerosol properties and air pollutants over an urban area SO ATMOSPHERIC RESEARCH LA English DT Article; Proceedings Paper CT 16th International Conference on Nucleation and Atmospheric Aerosols CY JUL 26-30, 2004 CL Kyoto Univ, Grad Sch Energy Sci, Kyoto, JAPAN SP Japan Assoc Aerosol Sci & Technol, Minist Educ, Culture, Sports, Sci & Technol, Commemorat Org Japan World Exposit 70 HO Kyoto Univ, Grad Sch Energy Sci DE atmospheric aerosols; air pollutants; PM2.5; SPM; OBC ID SKY RADIANCE MEASUREMENTS; OPTICAL-PROPERTIES; THICKNESS; AERONET; NETWORK; DEPTH; SUN AB For a better understanding of urban aerosols, sun/sky photometry has been undertaken at the Kinki University campus in Higashi-Osaka as a NASA/AERONET station since 2002. A new instrument, the SPM-613D (Kimoto Electric), has been taking measurements at the same site since March 15, 2004. The relationship between aerosol properties obtained from radiometry with AERONET and the SPM measurements is examined. It is found that there is a linear correlation between SPM concentrations and aerosol properties, which indicates that aerosol characteristics can be estimated from SPM data, and vice versa. It is also shown that the air quality of the Higashi-Osaka site is poor due to not only the anthropogenic particles by local emissions, such as diesel vehicles and chemical industries, but also due to the dust particles coming from continental desert areas by large scale climatic conditions. (c) 2006 Elsevier B.V. All rights reserved. C1 Kinki Univ, Fac Sci & Technol, Higashiosaka, Osaka 5778502, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mukai, S (reprint author), Kinki Univ, Fac Sci & Technol, Higashiosaka, Osaka 5778502, Japan. EM mukai@info.kindai.ac.jp NR 16 TC 21 Z9 22 U1 1 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 J9 ATMOS RES JI Atmos. Res. PD DEC PY 2006 VL 82 IS 3-4 SI SI BP 643 EP 651 DI 10.1016/j.atmosres.2006.02.020 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 118FA UT WOS:000242926500018 ER PT J AU Decker, KLM Boerner, REJ AF Decker, Kelly L. M. Boerner, Ralph E. J. TI Mass loss and nutrient release from decomposing evergreen and deciduous Nothofagus litters from the Chilean Andes SO AUSTRAL ECOLOGY LA English DT Article DE Chilean Nothofagus; leaf lifespan; litter decomposition; nitrogen; phosphorus ID TIERRA-DEL-FUEGO; LEAF-LITTER; MICROCOSM EXPERIMENT; PHOSPHORUS DYNAMICS; PUMILIO FORESTS; LIGNIN CONTROL; DOUGLAS-FIR; WIDE-RANGE; NITROGEN; RATES AB Leaf litter decomposition experiments were conducted on two deciduous (Nothofagus obliqua (roble)) and Nothofagus pumilio (lenga)) and one evergreen (Nothofagus dombeyi) Nothofagus (Nothofagaceae) species from a single Chilean forest in order to understand how congeneric trees with differing leaf lifespans impact the soil in which they grow. Single-species litter samples were decomposed in a mixed hardwood forest in Ohio and in a deciduous-evergreen Nothofagus forest in Chile. In the Ohio forest, the two deciduous species' litters decomposed at k approximate to 1.00 per year and the evergreen at k approximate to 0.75 per year. In Chile k ranged from k approximate to 0.06 (N. obliqua) to k approximate to 0.23 (N. pumilio) per year. In both experiments, N and P were released faster from the deciduous litters than from evergreen litter. In Ohio, evergreen litter immobilized more N and P for a longer time period than did deciduous litter. As N. dombeyi stands tend to have lower available soil N and P in this particular mixed Nothofagus forest, the increased time of N and P immobilization by N. dombeyi litter suggests a feedback role of the tree itself in perpetuating low N and P soil conditions. C1 NASA, Calif State Univ Monterey Bay, Ames Res Ctr, Moffett Field, CA 94035 USA. Ohio State Univ, Dept Evol Ecol & Organismal Biol, Columbus, OH 43210 USA. RP Decker, KLM (reprint author), NASA, Calif State Univ Monterey Bay, Ames Res Ctr, Mail Stop 242-4, Moffett Field, CA 94035 USA. EM kdecker@mail.arc.nasa.gov RI Decker, Kelly/J-1831-2012 NR 47 TC 11 Z9 12 U1 0 U2 7 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1442-9985 J9 AUSTRAL ECOL JI Austral Ecol. PD DEC PY 2006 VL 31 IS 8 BP 1005 EP 1015 DI 10.1111/j.1442-9993.2006.01670.x PG 11 WC Ecology SC Environmental Sciences & Ecology GA 104JP UT WOS:000241955000010 ER PT J AU Lu, CH Jalbout, AF Adamowicz, L Wang, Y Yin, CS AF Lu, C. H. Jalbout, A. F. Adamowicz, L. Wang, Y. Yin, C. S. TI Prediction of gas chromatographic retention indices of benzene dicarboxylic diesters using novel topological indices SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID PHTHALATE-ESTERS C1 Shanghai Jiao Tong Univ, Sch Environm Sci & Engn, Shanghai 200030, Peoples R China. Univ Arizona, NASA, Astrobiol Inst, Tucson, AZ 85721 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Natl Autonomous Univ Mexico, Inst Chem, Mexico City 04510, DF, Mexico. RP Yin, CS (reprint author), Shanghai Jiao Tong Univ, Sch Environm Sci & Engn, Shanghai 200030, Peoples R China. NR 12 TC 6 Z9 6 U1 1 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0007-4861 J9 B ENVIRON CONTAM TOX JI Bull. Environ. Contam. Toxicol. PD DEC PY 2006 VL 77 IS 6 BP 793 EP 798 DI 10.1007/s00128-006-1213-6 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 122LA UT WOS:000243227300002 PM 17219296 ER PT J AU Laurel, BJ Bradbury, IR AF Laurel, Benjamin J. Bradbury, Ian R. TI "Big" concerns with high latitude marine protected areas (MPAs): trends in connectivity and MPA size SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID RESERVES; DISPERSAL; IMPACT AB The success of marine protected areas (MPAs) as fisheries management tools in tropical latitudes has generated interest in their applicability and potential elsewhere. Here we suggest that dispersal and gene flow in marine fish populations (a primary biological consideration for marine reserve design) increases with latitude. For example, north temperate fish species at latitudes between 40 degrees and 45 degrees had about three times greater dispersal potential (planktonic larval duration (PLD), n = 96 species) and genetic homogeneity (F-ST, n = 100 species) than fish species near equatorial regions. Using the PLD and FST relationships, dispersal increases at a rate of similar to 8% per degree of latitude north or south of the equator. Therefore tropical MPAs should not serve as direct scalar templates in other regions, but rather should be used as a basis against which higher-latitude MPAs should be scaled. However, a review of 429 existing MPAs indicates that no such changes in reserve size have been implemented with respect to latitude. Fisheries managers must be prepared and willing to implement MPAs at large scales in high latitudes, either as single reserves or in a network, or else we lose the legitimacy of a new and promising management tool for conserving marine biodiversity in cold ocean regions. C1 Fisheries & Oceans Canada, Environm & Ecosyst Sci Sect, St John, NF A1C 5X1, Canada. Dalhousie Univ, Dept Biol, Marine Gene Probe Lab, Halifax, NS B3H 4R2, Canada. RP Laurel, BJ (reprint author), NOAA, Alaska Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA. EM ben.laurel@noaa.gov NR 12 TC 33 Z9 33 U1 3 U2 20 PU NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS PI OTTAWA PA BUILDING M 55, OTTAWA, ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD DEC PY 2006 VL 63 IS 12 BP 2603 EP 2607 DI 10.1139/F06-151 PG 5 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 132LV UT WOS:000243945200001 ER PT J AU Toth, VT Turyshev, SG AF Toth, Viktor T. Turyshev, Slava G. TI The Pioneer anomaly: seeking an explanation in newly recovered data SO CANADIAN JOURNAL OF PHYSICS LA English DT Article AB The Pioneer 10 and 11 spacecraft yielded very accurate navigation in deep space that was, however, limited by a small, anomalous frequency drift of their carrier signals received by the radio-tracking stations of the NASA Deep Space Network (DSN). This drift signifies a discrepancy between the frequency of the Doppler signals observed by the DSN and that frequency modeled using modern-day deep space navigational codes. This discrepancy, evident in the data for both spacecraft, was interpreted as an approximately constant acceleration. This acceleration has become known as the Pioneer anomaly. The origin of this anomaly is yet unknown. Recent efforts to explain the effect included a search for independent confirmation, analyses of conventional mechanisms, even ideas rooted in new physics, and proposals for a dedicated mission. We assert that to determine the origin of the Pioneer anomaly, and especially before any discussion of new physics and (or) a dedicated mission can take place, one must analyze the entire set of radiometric Doppler data received from Pioneer 10 and 11. In this paper, we report on our efforts to recover and utilize the complete set of radio Doppler and telemetry records of the Pioneer 10 and I I spacecraft. The collection of radio Doppler data for both missions is now complete; we are ready to begin its evaluation. We also make progress utilizing the recently recovered Pioneer telemetry data in the development of a complete engineering profile of the spacecraft. We present a strategy for studying the effect of on-board-generated small forces with this newly recovered information on the performance of thermal, electrical, power, communication, and other subsystems, in conjunction with the analysis of the entire set of the Pioneer Doppler data. We report on the preparation, for the upcoming analysis of the newly recovered data with the ultimate goal of determining the origin of the Pioneer anomaly. Finally, we discuss implications Of Our ongoing research of the Pioneer anomaly for other missions, most notably for New Horizons, NASA's recently launched mission to Pluto. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM vttoth@vttoth.com RI Toth, Viktor/D-3502-2009 OI Toth, Viktor/0000-0003-3651-9843 NR 27 TC 12 Z9 12 U1 0 U2 1 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0008-4204 J9 CAN J PHYS JI Can. J. Phys. PD DEC PY 2006 VL 84 IS 12 BP 1063 EP 1087 DI 10.1139/P07-005 PG 25 WC Physics, Multidisciplinary SC Physics GA 164VZ UT WOS:000246264200003 ER PT J AU Swimmer, JY AF Swimmer, J. Yonat TI Relationship Between Basking and Fibropapillomatosis in Captive Green Turtles (Chelonia mydas) SO CHELONIAN CONSERVATION AND BIOLOGY LA English DT Article AB This research was conducted to determine a potential relationship between fibropapillomatosis (FP) and basking behavior in green turtles (Chelonia mydas) in Hawaii. Only turtles with FP were observed basking, and basking resulted in increased body temperature of 2.9 degrees C above ambient. C1 Pacific Isl Fisheries Sci Ctr, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA. RP Swimmer, JY (reprint author), Pacific Isl Fisheries Sci Ctr, Natl Marine Fisheries Serv, 2570 Dole St, Honolulu, HI 96822 USA. EM Yonat.Swimmer@noaa.gov FU National Marine Fisheries Service; Lerner Grey Fund for Marine Research (American Museum Of Natural History); University of Michigan FX I Would like to thank G. Balazs, R. Brill, T. Root, and G.C. Whitlow for invaluable assistance throughout the Course of this research Lis well Lis writing of the manuscript. I thank A. Southwood and M. Musyl for editorial comments. This research was Supported in parts by the National Marine Fisheries Service. Sigma-Xi Grants-in-Aid of Research, Lerner Grey Fund for Marine Research (American Museum Of Natural History). and the University of Michigan. Animal maintenance and experimental protocols were approved by the University of Michigan Institutional Animal Care and Use Committee. Collecting permits were obtained from the National Marine Fisheries Service. Southwest Fisheries Science Center Honolulu Laboratory. NR 30 TC 6 Z9 6 U1 1 U2 9 PU CHELONIAN RESEARCH FOUNDATION PI LUNENBURG PA 168 GOODRICH ST., LUNENBURG, MA USA SN 1071-8443 J9 CHELONIAN CONSERV BI JI Chelonian Conserv. Biol. PD DEC PY 2006 VL 5 IS 2 BP 305 EP 309 DI 10.2744/1071-8443(2006)5[305:RBBAFI]2.0.CO;2 PG 5 WC Zoology SC Zoology GA V77VR UT WOS:000205261500021 ER PT J AU Ibrahim, M El-Haes, H Jalbout, AF AF Ibrahim, Medhat El-Haes, Hanan Jalbout, Abraham F. TI Semiempirical molecular modelling study of C-60 doped with silicon, germanium, and aluminium SO CHINESE JOURNAL OF PHYSICS LA English DT Article ID FIRST PRINCIPLES; SUPERCONDUCTIVITY; SUSCEPTIBILITY; OPTIMIZATION; FULLERENES; PARAMETERS; DYNAMICS; CLUSTERS; STATE AB Fullerene derivatives have been shown to make contributions in many types of applications. The structure and vibrational spectra Of C-60 doped with Si, Ge, and Al were investigated by the PM3 molecular modeling technique. The doping effect is discussed in terms of the change in the C-C bond lengths, net atomic charge distribution, total dipole moment, and final heat of formation. The obtained results indicate that the C-C distances are enlarged as a result of doping. Furthermore, there is a complete change in the net atomic charge distribution, as well as a corresponding increase in the value of the total dipole moment. Four characteristic bands of C-60 were seen in the vibrational spectra as well as a new band appearing as a result of the doping process. C1 Natl Res Ctr, Dept Spect, Cairo, Egypt. Ain Shams Univ, Fac Women Arts Sci & Educ, Cairo, Egypt. Univ Arizona, NASA, Astrobiol Inst, Dept Chem, Tucson, AZ 85721 USA. Univ Nacl Autonoma Mexico, Inst Chem, Mexico City 04510, DF, Mexico. RP Ibrahim, M (reprint author), Natl Res Ctr, Dept Spect, Cairo, Egypt. OI IBRAHIM, Medhat/0000-0002-9698-0837 NR 30 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0577-9073 J9 CHINESE J PHYS JI Chin. J. Phys. PD DEC PY 2006 VL 44 IS 6 BP 432 EP 439 PG 8 WC Physics, Multidisciplinary SC Physics GA 120AB UT WOS:000243054500003 ER PT J AU Butchart, N Scaife, AA Bourqui, M de Grandpre, J Hare, SHE Kettleborough, J Langematz, U Manzini, E Sassi, F Shibata, K Shindell, D Sigmond, M AF Butchart, N. Scaife, A. A. Bourqui, M. de Grandpre, J. Hare, S. H. E. Kettleborough, J. Langematz, U. Manzini, E. Sassi, F. Shibata, K. Shindell, D. Sigmond, M. TI Simulations of anthropogenic change in the strength of the Brewer-Dobson circulation SO CLIMATE DYNAMICS LA English DT Article ID GRAVITY-WAVE PARAMETERIZATION; CHEMISTRY-CLIMATE MODEL; GENERALIZED ELIASSEN-PALM; MIDDLE ATMOSPHERE; INTERACTIVE CHEMISTRY; STRATOSPHERIC TEMPERATURE; GREENHOUSE GASES; OZONE DEPLETION; DOUBLED CO2; TROPOSPHERE AB The effect of climate change on the Brewer-Dobson circulation and, in particular, the large-scale seasonal-mean transport between the troposphere and stratosphere is compared in a number of middle atmosphere general circulation models. All the models reproduce the observed upwelling across the tropical tropopause balanced by downwelling in the extra tropics, though the seasonal cycle in upwelling in some models is more semi-annual than annual. All the models also consistently predict an increase in the mass exchange rate in response to growing greenhouse gas concentrations, irrespective of whether or not the model includes interactive ozone chemistry. The mean trend is 11 kt s(-1) year(-1) or about 2% per decade but varies considerably between models. In all but one of the models the increase in mass exchange occurs throughout the year though, generally, the trend is larger during the boreal winter. On average, more than 60% of the mean mass fluxes can be explained by the EP-flux divergence using the downward control principle. Trends in the annual mean mass fluxes derived from the EP-flux divergence also explain about 60% of the trend in the troposphere-to-stratosphere mass exchange rate when averaged over all the models. Apart from two models the interannual variability in the downward control derived and actual mass fluxes were generally well correlated, for the annual mean. C1 Met Off, Hadley Ctr, Exeter EX1 3PB, Devon, England. Univ Reading, Dept Meteorol, Reading, Berks, England. McGill Univ, Montreal, PQ, Canada. British Atmospher Data Ctr, Rutherford Lab, Didcot, Oxon, England. Free Univ Berlin, D-1000 Berlin, Germany. Natl Inst Geophys & Volcanol, Bologna, Italy. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Meteorol Res Inst, Tsukuba, Ibaraki 305, Japan. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Univ Toronto, Toronto, ON, Canada. RP Butchart, N (reprint author), Met Off, Hadley Ctr, FitzRoy Rd, Exeter EX1 3PB, Devon, England. EM neal.butchart@metoffice.gov.uk RI Manzini, Elisa/H-5760-2011; Shindell, Drew/D-4636-2012; Sigmond, Michael /K-3169-2012; OI Sigmond, Michael /0000-0003-2191-9756; Sassi, Fabrizio/0000-0002-9492-7434 NR 54 TC 217 Z9 223 U1 4 U2 40 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD DEC PY 2006 VL 27 IS 7-8 BP 727 EP 741 DI 10.1007/s00382-006-0162-4 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 094SB UT WOS:000241258200005 ER PT J AU Armstrong, JB Olson, SL T'ien, JS AF Armstrong, J. B. Olson, S. L. T'ien, J. S. TI Transient model and experimental validation of low-stretch solid-fuel flame extinction and stabilization in response to a step change in gravity SO COMBUSTION AND FLAME LA English DT Article DE low-stretch flame; solid fuel; transient response; extinction; gravity; heat loss ID DIFFUSION FLAME; MICROGRAVITY; FLOW; COMBUSTION AB A transient stagnation point numerical model was developed that includes gas-phase and solid-phase radiation and solid-phase coupling to describe the dynamic transition from a flame at higher stretch to a flame at lower stretch. To validate the model, low-stretch experiments using PMMA samples were performed in NASA Glenn's Zero Gravity Facility. When the final stretch rate is sufficiently low, the flame transitions to extinction. Above the critical stretch rate, the flame reaches a new steady state with larger flame standoff distance. But the transient process is very dynamic. The model captures the transient behavior of the experimental flame. A parametric study of the surface temperature and standoff distance demonstrates that the flame standoff overshoot at the beginning of the drop is the result of the faster response of the gas phase and the slower response of the solid layer immediate beneath the surface sample. The predicted surface energy balance shows that as the feedback from the flame decreases, the importance of the ongoing heat losses becomes greater, and extinction is observed when these losses represent 80% or more of the flame feedback. Extinction is attributable to insufficient heat feedback to the surface to compensate for existing heat losses under these low-stretch conditions. There is good agreement between the model and both the drop tower and previous buoyant low-stretch experiments in terms of a limiting stretch rate. This work supports the hypothesis that buoyant experiments with large burners can be used to evaluate the low-gravity, low-stretch flammability limits of a material. Published by Elsevier Inc. on behalf of The Combustion Institute. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. RP Olson, SL (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM sandra.olson@grc.nasa.gov NR 16 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD DEC PY 2006 VL 147 IS 4 BP 262 EP 277 DI 10.1016/j.combustflame.2006.09.007 PG 16 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 117LQ UT WOS:000242875100002 ER PT J AU Yungster, S Radhakrishnan, K Breisacher, K AF Yungster, S. Radhakrishnan, K. Breisacher, K. TI Computational study of NOx formation in hydrogen-fuelled pulse detonation engines SO COMBUSTION THEORY AND MODELLING LA English DT Article DE pulse detonation engine; oxides of nitrogen; gaseous detonation; unsteady combustion ID AIR MIXTURES; COMBUSTION AB The formation of NOx in hydrogen-fuelled pulse detonation engines (PDE) is investigated numerically. The computations are based on the axisymmetric Enter equations and a detailed combustion model consisting of 12 species and 27 reactions. A multi-level, dynamically adaptive grid is utilized, in order to resolve the structure of the detonation front. Computed NO concentrations are in good agreement with experimental measurements obtained at two operating frequencies and two equivalence ratios. Additional computations examine the effects of equivalence ratio and residence time on NOx formation at ambient conditions. The results indicate that NOx formation in PDEs is very high for near stoichiometric mixtures. NOx reduction requires use of lean or rich mixtures and the shortest possible detonation tube. NOx emissions for very lean or very rich mixtures are, however, fairly insensitive to residence time. C1 NASA, Glenn Res Ctr, Inst Computat Mech Propuls, Cleveland, OH 44135 USA. RP Yungster, S (reprint author), NASA, Glenn Res Ctr, Inst Computat Mech Propuls, Cleveland, OH 44135 USA. EM shaye.yungster@grc.nasa.gov NR 25 TC 2 Z9 2 U1 0 U2 5 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1364-7830 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD DEC PY 2006 VL 10 IS 6 BP 981 EP 1002 DI 10.1080/13647830600876629 PG 22 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA 115ZK UT WOS:000242772100006 ER PT J AU Pena, J Hinchey, MG Ruiz-Cortes, A AF Pena, Joaquin Hinchey, Michael G. Ruiz-Cortes, Antonio TI Multi-agent system product lines: challenges and benefits SO COMMUNICATIONS OF THE ACM LA English DT Article C1 Univ Seville, Dept Comp Sci Languages & Syst, Seville, Spain. NASA, Goddard Space Flight Ctr, Software Engn Lab, Greenbelt, MD 20771 USA. RP Pena, J (reprint author), Univ Seville, Dept Comp Sci Languages & Syst, Seville, Spain. EM joaquinp@us.es; Michael.G.Hinchey@nasa.gov; aruiz@us.es RI Ruiz-Cortes, Antonio/B-9056-2008; Pena, Joaquin /K-8217-2012 OI Ruiz-Cortes, Antonio/0000-0001-9827-1834; Pena, Joaquin /0000-0001-9216-9695 NR 12 TC 10 Z9 10 U1 0 U2 2 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 2 PENN PLAZA, STE 701, NEW YORK, NY 10121-0701 USA SN 0001-0782 EI 1557-7317 J9 COMMUN ACM JI Commun. ACM PD DEC PY 2006 VL 49 IS 12 BP 82 EP 84 DI 10.1145/1183236.1183272 PG 3 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 115YR UT WOS:000242770200025 ER PT J AU Morscher, GN AF Morscher, Gregory N. TI Modeling the elastic modulus of 2D woven CVISiC composites SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE ceramic matrix composites; elastic modulus ID NONLINEAR MECHANICAL-BEHAVIOR; SIC/SIC COMPOSITE; MATRIX COMPOSITES; BRITTLE-MATRIX; DAMAGE AB The use of fiber, interphase, CVI SiC minicomposites as structural elements for 2D-woven SiC fiber-reinforced chemically vapor infiltrated (CVI) SiC matrix composites is demonstrated to be a viable approach to model the elastic modulus of these composite systems when tensile loaded in an orthogonal direction. The 0 degrees (loading direction) and 90 degrees (perpendicular to loading direction) oriented minicomposites as well as the open porosity and excess SiC associated with CVI SiC composites were all modeled as parallel elements using simple Rule of Mixtures techniques. Excellent agreement for a variety of 2D woven Hi-Nicalon (TM) fiber-reinforced and Sylramic-iBN reinforced CVI SiC matrix composites that differed in numbers of plies, constituent content, thickness, density, and number of woven tows in either direction (i.e, balanced weaves versus unbalanced weaves) was achieved. It was found that elastic modulus was not only dependent on constituent content, but also the degree to which 90 degrees minicomposites carried load. This depended on the degree of interaction between 90 degrees and 0 degrees minicomposites which was quantified to some extent by composite density. The relationships developed here for elastic modulus only necessitated the knowledge of the fractional contents of fiber, interphase and CVI SiC as well as the tow size and shape. It was concluded that such relationships are fairly robust for orthogonally loaded 2D woven CVI SiC composite system and can be implemented by ceramic matrix composite component modelers and designers for modeling the local stiffness in simple or complex parts fabricated with variable constituent contents. (c) 2006 Elsevier Ltd. All rights reserved. C1 NASA, Glenn Res Ctr, Ohio Aerosp Inst, Ceram Branch, Cleveland, OH 44224 USA. RP Morscher, GN (reprint author), NASA, Glenn Res Ctr, Ohio Aerosp Inst, Ceram Branch, MS 106-5,Brookpk, Cleveland, OH 44224 USA. EM Gregory.N.Morscher@grc.nasa.gov NR 22 TC 15 Z9 18 U1 1 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PD DEC PY 2006 VL 66 IS 15 BP 2804 EP 2814 DI 10.1016/j.compscitech.2006.02.030 PG 11 WC Materials Science, Composites SC Materials Science GA 100FW UT WOS:000241654500022 ER PT J AU Teague, WJ Jarosz, E Carnes, MR Mitchell, DA Hogan, PJ AF Teague, W. J. Jarosz, E. Carnes, M. R. Mitchell, D. A. Hogan, P. J. TI Low-frequency current variability observed at the shelfbreak in the northeastern Gulf of Mexico: May-October, 2004 SO CONTINENTAL SHELF RESEARCH LA English DT Article DE coastal currents; continental shelf; continental slope; barotropic field; baroclinic field; Gulf of Mexico; (28-31N, 86-90W) ID WEST FLORIDA SHELF; CONTINENTAL-SHELF; HURRICANE-IVAN; CIRCULATION; BOUNDARY; PATTERNS; SATELLITE; MODEL; WATER; CYCLE AB High-resolution current measurements were made in the Northeastern Gulf of Mexico by the Naval Research Laboratory (NRL) as part of its Slope to Shelf Energetics and Exchange Dynamics (SEED) project. The major goal of SEED is to understand the mechanisms that transfer properties across the shelf slope. Fourteen acoustic Doppler current profilers (ADCPs) were deployed just west of the Desoto Canyon on the shelf and down the slope from May to November, 2004 to measure nearly full water column current profiles. Currents were found more variable on the shelf than on the slope but in the mean strongly tended to follow bathymetry, particularly on the slope. During the SEED time period currents were driven by both local and remote winds, by cyclonic eddies associated with the Loop Current extension and Loop Current rings.. by smaller eddies associated with the cyclonic eddies, by frontal meanders or streamers associated with the eddies, and by tropical storms. Currents were highly barotropic, accounting for more than 80% of the eddy kinetic energy (EKE). Current magnitudes generally increased from west to east, towards the Desoto Canyon. Tropical storms had a relatively minor short-term effect upon mass transports. Cross-shelf transports were much smaller than the along-shelf transports. Onshore transports were stronger on the western side of the array while offshore transports were stronger on the eastern side of the array near the Desoto Canyon. Offshore transports generally occurred during eastward flow periods, onshore transports during westward flow periods, and both during eddy periods. Mesoscale eddies also provided contributions to cross-shelf exchange. Large scale circulation features could be determined from the first two empirical-orthogonal function (EOF) modes which accounted for 83% of the variance and were strongly related to the integrated wind stress. Published by Elsevier Ltd. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. RP Teague, WJ (reprint author), USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. EM teague@nrlssc.navy.mil NR 41 TC 17 Z9 17 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD DEC PY 2006 VL 26 IS 20 BP 2559 EP 2582 DI 10.1016/j.csr.2006.08.002 PG 24 WC Oceanography SC Oceanography GA 115XH UT WOS:000242766600004 ER PT J AU Cartinella, JL Cath, TY Flynn, MT Miller, GC Hunter, KW Childress, AE AF Cartinella, Joshua L. Cath, Tzahi Y. Flynn, Michael T. Miller, Glenn C. Hunter, Kenneth W., Jr. Childress, Amy E. TI Removal of natural steroid hormones from wastewater using membrane contactor processes SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ENDOCRINE DISRUPTING COMPOUNDS; REVERSE-OSMOSIS; NANOFILTRATION MEMBRANES; ACTIVE COMPOUNDS; NF/RO MEMBRANES; PRETREATMENT; REJECTION; EFFLUENT; DISTILLATION; CONTAMINANTS AB Growing demands for potable water have strained water resources and increased interest in wastewater reclamation for potable reuse. This interest has brought increased attention to endocrine-disrupting chemicals (EDCs) as emerging water contaminants. The effect of EDCs, and in particular natural steroid hormones, on humans is of heightened interest in the study of wastewater reuse in advanced life support systems (e.g., space missions) because they are excreted in urine and have high endocrine-disrupting potencies. Direct contact membrane distillation (DCMD) and forward osmosis (FO) are being investigated for wastewater treatment in space. Retention of two natural steroid hormones, estrone and 17 beta-estradiol, by these two processes was evaluated in the current investigation. DCMD provided greater than 99.5% hormone rejection; DCMD also provided constant flux, greater than 99.9% urea and ammonia rejection, and high water recovery. FO provided from 77 to 99% hormone rejection depending on experiment duration and feed solution chemistry. C1 Colorado Sch Mines, Div Environm Sci & Engn, Golden, CO 80401 USA. Univ Nevada, Dept Civil & Environm Engn, Reno, NV 89557 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Nevada, Dept Nat Resources & Environm Sci, Reno, NV 89557 USA. Univ Nevada, Dept Microbiol & Immunol, Reno, NV 89557 USA. RP Cath, TY (reprint author), Colorado Sch Mines, Div Environm Sci & Engn, Golden, CO 80401 USA. EM tcath@mines.edu RI Cath, Tzahi/H-6458-2011 NR 24 TC 87 Z9 95 U1 4 U2 70 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD DEC 1 PY 2006 VL 40 IS 23 BP 7381 EP 7386 DI 10.1021/es060550i PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 110GT UT WOS:000242367100045 PM 17180992 ER PT J AU Sallenger, AH Stockdon, HF Fauver, L Hansen, M Thompson, D Wright, CW Lillycrop, J AF Sallenger, Asbury H. Stockdon, Hilary F. Fauver, Laura Hansen, Mark Thompson, David Wright, C. Wayne Lillycrop, Jeff TI Hurricanes 2004: An overview of their characteristics and coastal change SO ESTUARIES AND COASTS LA English DT Article ID AIRBORNE TOPOGRAPHIC LIDAR; BEACH CHANGES AB Four hurricanes battered the state of Florida during 2004, the most affecting any state since Texas endured four in 1884. Each of the storms changed the coast differently. Average shoreline change within the right front quadrant of hurricane force winds varied from I in of shoreline advance to 20 in of retreat, whereas average sand volume change varied from 11 to 66 m(3) m(-1) of net loss (erosion). These changes did not scale simply with hurricane intensity as described by the Saffir-Simpson Hurricane Scale. The strongest storm of the season, category 4 Hurricane Charley, had the least shoreline retreat. This was likely because of other factors like the storm's rapid forward speed and small size that generated a lower storm surge than expected. Two of the storms, Hurricanes Frances and Jeanne, affected nearly the same area on the Florida east coast just 3 wk apart. The first storm, Frances, although weaker than the second, caused greater shoreline retreat and sand volume erosion. As a consequence, Hurricane Frances may have stripped away protective beach and exposed dunes to direct wave attack during Jeanne, although there was significant dune erosion during both storms. The maximum shoreline change for all four hurricanes occurred during Ivan on the coasts of eastern Alabama and the Florida Panhandle. The net volume change across a barrier island within the Ivan impact zone approached zero because of massive overwash that approximately balanced erosion of the beach. These data from the 2004 hurricane season will prove useful in developing new ways to scale and predict coastal-change effects during hurricanes. C1 US Geol Survey, Ctr Coastal & Watershed Studies, St Petersburg, FL 33701 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. USA, Engineer Dist Mobile, Joint Airborne Lidar Bathymetry Tech Ctr Expertis, Mobile, AL 36602 USA. RP Stockdon, HF (reprint author), US Geol Survey, Ctr Coastal & Watershed Studies, 600 4th St S, St Petersburg, FL 33701 USA. EM hstockdon@usgs.gov OI Stockdon, Hilary/0000-0003-0791-4676 NR 25 TC 45 Z9 50 U1 2 U2 22 PU ESTUARINE RESEARCH FEDERATION PI PORT REPUBLIC PA 2018 DAFFODIL, PO BOX 510, PORT REPUBLIC, MD 20676 USA SN 1559-2723 J9 ESTUARIES COASTS JI Estuaries Coasts PD DEC PY 2006 VL 29 IS 6A BP 880 EP 888 PG 9 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 133JS UT WOS:000244009800002 ER PT J AU Zhang, SN Clowers, KG Powell, D AF Zhang, Songning Clowers, Kurt G. Powell, Douglas TI Ground reaction force and 3D biomechanical characteristics of walking in short-leg walkers SO GAIT & POSTURE LA English DT Article DE short-leg walker; walking boot; gait; 3D biomechanics; walking ID TOTAL-CONTACT CAST; TIBIAL TENDON DYSFUNCTION; FOOT; PRESSURES; BOOT; IMMOBILIZATION; TENDINOPATHY; MANAGEMENT; EFFICACY; DESIGN AB Short-leg walking boots offer several advantages over traditional casts. However, their effects on ground reaction forces (GRF) and three-dimensional (3D) bionnechanics are not fully understood. The purpose of the study was to examine 3D lower extremity kinematics and joint dynamics during walking in two different short-leg walking boots. Eleven (five females and six males) healthy subjects performed five level walking trials in each of three conditions: two testing boot conditions, Gait Walker (DeRoyal Industries, Inc.) and Equalizer (Royce Medical Co.), and one pair of laboratory shoes (Noveto, Adidas). A force platform and a 6-camera Vicon motion analysis system were used to collect GRFs and 3D kinematic data during the testing session. A one-way repeated measures analysis of variance (ANOVA) was used to evaluate selected kinematic, GRF, and joint kinetic variables (p < 0.05). The results revealed that both short-leg walking boots were effective in minimizing ankle eversion and hip adduction. Neither walker increased the bimodal vertical GRF peaks typically observed in normal walking. However, they did impose a small initial peak (< 1 BW) earlier in the stance phase. The Gait Walker also exhibited a slightly increased vertical GRF during midstance. These characteristics may be related to the sole materials/design, the restriction of ankle movements, and/or the elevated heel heights of the tested walkers. Both walkers appeared to increase the demand on the knee extensors while they decreased the demand of the knee and hip abductors based on the joint kinetic results. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Tennessee, Biomech Sports Med Lab, Knoxville, TN 37996 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Shanghai Univ Sport, Shanghai, Peoples R China. RP Zhang, SN (reprint author), Univ Tennessee, Biomech Sports Med Lab, 1914 Andy Holt Ave, Knoxville, TN 37996 USA. EM szhang@utk.edu OI Zhang, Songning/0000-0002-3712-9129 NR 17 TC 12 Z9 13 U1 1 U2 7 PU ELSEVIER IRELAND LTD PI CLARE PA ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND SN 0966-6362 J9 GAIT POSTURE JI Gait Posture PD DEC PY 2006 VL 24 IS 4 BP 487 EP 492 DI 10.1016/j.gaitpost.2005.12.003 PG 6 WC Neurosciences; Orthopedics; Sport Sciences SC Neurosciences & Neurology; Orthopedics; Sport Sciences GA 114KZ UT WOS:000242666400015 PM 16414263 ER PT J AU Claire, MW Catling, DC Zahnle, KJ AF Claire, M. W. Catling, D. C. Zahnle, K. J. TI Biogeochemical modelling of the rise in atmospheric oxygen SO GEOBIOLOGY LA English DT Article AB Understanding the evolution of atmospheric molecular oxygen levels is a fundamental unsolved problem in Earth's history. We develop a quantitative biogeochemical model that simulates the Palaeoproterozoic transition of the Earth's atmosphere from a weakly reducing state to an O-2-rich state. The purpose is to gain an insight into factors that plausibly control the timing and rapidity of the oxic transition. The model uses a simplified atmospheric chemistry (parameterized from complex photochemical models) and evolving redox fluxes in the Earth system. We consider time-dependent fluxes that include organic carbon burial and associated oxygen production, reducing gases from metamorphic and volcanic sources, oxidative weathering, and the escape of hydrogen to space. We find that the oxic transition occurs in a geologically short time when the O-2-consuming flux of reducing gases falls below the flux of organic carbon burial that produces O-2. A short timescale for the oxic transition is enhanced by a positive feedback due to decreasing destruction of O-2 as stratospheric ozone forms, which is captured in our atmospheric chemistry parameterization. We show that one numerically self-consistent solution for the rise of O-2 involves a decline in flux of reducing gases driven by irreversible secular oxidation of the crust caused by time-integrated hydrogen escape to space in the preoxic atmosphere, and that this is compatible with constraints from the geological record. In this model, the timing of the oxic transition is strongly affected by buffers of reduced materials, particularly iron, in the continental crust. An alternative version of the model, where greater fluxes of reduced hydrothermal cations from the Archean seafloor consume O-2, produces a similar history of O-2 and CH4. When climate and biosphere feedbacks are included in our model of the oxic transition, we find that multiple 'Snowball Earth' events are simulated under certain circumstances, as methane collapses and rises repeatedly before reaching a new steady-state. C1 [Claire, M. W.] Univ Washington, Dept Astron, Seattle, WA 98195 USA. [Catling, D. C.] Univ Bristol, Dept Earth Sci, Bristol BS8 1RJ, Avon, England. [Catling, D. C.] Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. [Zahnle, K. J.] NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Claire, MW (reprint author), Univ Washington, Dept Astron, Box 351580, Seattle, WA 98195 USA. EM mclaire@astro.washington.edu RI Catling, David/D-2082-2009; OI Catling, David/0000-0001-5646-120X NR 176 TC 73 Z9 75 U1 5 U2 53 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1472-4677 EI 1472-4669 J9 GEOBIOLOGY JI Geobiology PD DEC PY 2006 VL 4 IS 4 BP 239 EP 269 DI 10.1111/j.1472-4669.2006.00084.x PG 31 WC Biology; Environmental Sciences; Geosciences, Multidisciplinary SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Geology GA V06CT UT WOS:000207172400003 ER PT J AU Zahnle, K Claire, M Catling, D AF Zahnle, K. Claire, M. Catling, D. TI The loss of mass-independent fractionation in sulfur due to a Palaeoproterozoic collapse of atmospheric methane SO GEOBIOLOGY LA English DT Article ID EARTHS EARLY ATMOSPHERE; ARCHEAN ATMOSPHERE; MOLECULAR FOSSILS; HAMERSLEY BASIN; ANCIENT EARTH; EARLY HISTORY; EVOLUTION; CARBON; OXYGEN; OXIDATION AB We use a 1-D numerical model to study the atmospheric photochemistry of oxygen, methane, and sulfur after the advent of oxygenic photosynthesis. We assume that mass-independent fractionation (MIF) of sulfur isotopes - characteristic of the Archean - was best preserved in sediments when insoluble elemental sulfur (S-8) was an important product of atmospheric photochemistry. Efficient S-8 production requires three things: (i) very low levels of tropospheric O-2; (ii) a source of sulfur gases to the atmosphere at least as large as the volcanic SO2 source today; and (iii) a sufficiently high abundance of methane or other reduced gas. All three requirements must be met. We suggest that the disappearance of a strong MIF sulfur signature at the beginning of the Proterozoic is better explained by the collapse of atmospheric methane, rather than by a failure of volcanism or the rise of oxygen. The photochemical models are consistent in demanding that methane decline before O-2 can rise (although they are silent as to how quickly), and the collapse of a methane greenhouse effect is consistent with the onset of major ice ages immediately following the disappearance of MIF sulfur. We attribute the decline of methane to the growth of the oceanic sulfate pool as indicated by the widening envelope of mass- dependent sulfur fractionation through the Archean. We find that a given level of biological forcing can support either oxic or anoxic atmospheres, and that the transition between the anoxic state and the oxic state is inhibited by high levels of atmospheric methane. Transition from an oxygen-poor to an oxygen- rich atmosphere occurs most easily when methane levels are low, which suggests that the collapse of methane not only caused the end of MIF S and major ice ages, but it may also have enabled the rise of O-2. In this story the early Proterozoic ice ages were ended by the establishment of a stable oxic atmosphere, which protected a renewed methane greenhouse with an ozone shield. C1 [Zahnle, K.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Claire, M.; Catling, D.] Univ Washington, Astrobiol Program, Seattle, WA 98195 USA. [Claire, M.; Catling, D.] Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. [Catling, D.] Univ Bristol, Dept Earth Sci, Bristol BS8 1RJ, Avon, England. RP Zahnle, K (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. EM kevin.j.zahnle@nasa.gov RI Catling, David/D-2082-2009; OI Catling, David/0000-0001-5646-120X NR 52 TC 101 Z9 104 U1 3 U2 29 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1472-4677 EI 1472-4669 J9 GEOBIOLOGY JI Geobiology PD DEC PY 2006 VL 4 IS 4 BP 271 EP 283 DI 10.1111/j.1472-4669.2006.00085.x PG 13 WC Biology; Environmental Sciences; Geosciences, Multidisciplinary SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Geology GA V06CT UT WOS:000207172400004 ER PT J AU Riccardi, AL Arthur, MA Kump, LR AF Riccardi, Anthony L. Arthur, Michael A. Kump, Lee R. TI Sulfur isotopic evidence for chemocline upward excursions during the end-Permian mass extinction SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID TRIASSIC SUPERANOXIC EVENT; PHANEROZOIC SEAWATER; HYDROGEN-SULFIDE; OCEANIC ANOXIA; IMPACT CRATER; BOUNDARY; OXYGEN; EVOLUTION; SULFATE; CARBON AB The latest Permian was a time of major change in ocean chemistry, accompanying the greatest mass extinction of the Phanerozoic. To examine the nature of these changes, samples from two well-studied marine sections that span the Permian-Triassic boundary have been analyzed: the Meishan and Shangsi sections located in Southern China. Isotopic analysis of the carbonate-associated sulfate in these samples provides a detailed record of several isotopic shifts in delta S-34(CAS) approaching and across the PTB, ranging from +30 to -15 parts per thousand (VCDT), with repeated asynchronous fluctuations at the two locations. We interpret the patterns of isotopic shifts, in conjunction with other data, to indicate a shallow unstable chemocline overlying euxinic deep-water which periodically upwelled into the photic zone. These chemocline upward excursion events introduced sulfide to the photic zone stimulating a bloom of phototrophic sulfur oxidizing bacteria. We hypothesize that elemental sulfur globules produced by these organisms and 34 S-depleted pyrite produced in the euxinic water column were deposited in the sediment; later oxidation led to incorporation as CAS. This created the large changes to the delta S-34(CAS) observed in the latest Permian at these locations. (c) 2006 Elsevier Inc. All rights reserved. C1 Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA. RP Riccardi, AL (reprint author), Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. EM ariccard@geosc.psu.edu RI Kump, Lee/H-8287-2012; Arthur, Michael/E-2872-2014 OI Arthur, Michael/0000-0002-3028-6279 NR 55 TC 94 Z9 101 U1 4 U2 29 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC 1 PY 2006 VL 70 IS 23 BP 5740 EP 5752 DI 10.1016/j.gca.2006.08.005 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 108LK UT WOS:000242241100008 ER PT J AU Grotzinger, J Bell, J Herkenhoff, K Johnson, J Knoll, A McCartney, E McLennan, S Metz, J Moore, J Squyres, S Sullivan, R Ahronson, O ArvIdson, R Joliff, B Golombek, M Lewis, K Parker, T Soclerblom, J AF Grotzinger, J. Bell, J., III Herkenhoff, K. Johnson, J. Knoll, A. McCartney, E. McLennan, S. Metz, J. Moore, J. Squyres, S. Sullivan, R. Ahronson, O. ArvIdson, R. Joliff, B. Golombek, M. Lewis, K. Parker, T. Soclerblom, J. TI Sedimentary textures formed by aqueous processes, Erebus crater, Meridiani Planum, Mars SO GEOLOGY LA English DT Article DE Mars; water; cross-lamination; shrinkage cracks; sedimentary structures ID BURNS FORMATION; ENVIRONMENT; DIAGENESIS; OUTCROPS; ORIGIN; FLOWS; SAND AB New observations at Erebus crater (Olympia outcrop) by the Mars Exploration Rover Opportunity between sols 671 and 735 (a sol is a martian day) indicate that a diverse suite of primary and penecontemporaneous sedimentary structures is preserved in sulfate-rich bedrock. Centimeter-scale trough (festoon) cross-lamination is abundant, and is better expressed and thicker than previously described examples. Postdepositional shrinkage cracks in the same outcrop are interpreted to have formed in response to desiccation. Considered collectively, this suite of sedimentary structures provides strong support for the involvement of liquid water during accumulation of sedimentary rocks at Meridiani Planum. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Harvard Univ, Bot Museum, Cambridge, MA 02138 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Grotzinger, J (reprint author), CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RI Lewis, Kevin/E-5557-2012; OI Soderblom, Jason/0000-0003-3715-6407 NR 18 TC 47 Z9 47 U1 1 U2 6 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD DEC PY 2006 VL 34 IS 12 BP 1085 EP 1088 DI 10.1130/G22985A.1 PG 4 WC Geology SC Geology GA 113WZ UT WOS:000242630000024 ER PT J AU Ray, RD Luthcke, SB AF Ray, R. D. Luthcke, S. B. TI Tide model errors and GRACE gravimetry: towards a more realistic assessment SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE GRACE; satellite gravity; tides ID INTERSATELLITE TRACKING; PERTURBATION-THEORY; GRAVITY-FIELD AB The manner in which errors in tide models affect monthly gravity solutions from GRACE satellite data is re-examined. We perform a complete simulation of GRACE gravity estimation, including allowance for accelerometer calibrations and satellite state-vector adjustment. Errors in monthly geoid estimates are for most regions of a order of 0.5 mm, or roughly 1 cm of equivalent water height when smoothed over radii of 600 km. In polar regions where ocean tide models are suspect, errors can grow significantly larger: over 2 mm in geoid height, although over very localized regions. Errors from diurnal tides tend to cancel, but they are not completely eliminated, inducing geoid errors of the order of 0.3 mm. The currently accepted GRACE total error budget is roughly an order of magnitude larger than the component arising from tide modelling errors. C1 NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD USA. RP Ray, RD (reprint author), NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD USA. EM richard.ray@nasa.gov RI Ray, Richard/D-1034-2012; Luthcke, Scott/D-6283-2012 NR 18 TC 58 Z9 62 U1 2 U2 10 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X EI 1365-246X J9 GEOPHYS J INT JI Geophys. J. Int. PD DEC PY 2006 VL 167 IS 3 BP 1055 EP 1059 DI 10.1111/j.1365-246X.2006.03229.x PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 114JD UT WOS:000242661600001 ER PT J AU Hoffman, LF Ross, MD Varelas, J Jones, SM Jones, TA AF Hoffman, Larry F. Ross, Muriel D. Varelas, Joseph Jones, Sherri M. Jones, Timothy A. TI Afferent synapses are present in utricular hair cells from otoconia-deficient mice SO HEARING RESEARCH LA English DT Article DE head-tilt; synaptic ribbon; labyrinth; gravity orientation; vestibular ID MORPHOLOGICAL-CHANGES; RIBBON SYNAPSES; FINE-STRUCTURE; MUTANT MICE; GUINEA-PIG; MOUSE; ORGAN; CORTI; CAT; WEIGHTLESSNESS AB The head tilt mouse (het/het, abbr. het) is a naturally occurring mutant whose salient phenotypic traits include the complete absence of otocoina in both the utricle and saccule. Cursory histologic evaluation has indicated that the neuroepithelia exhibit a normal appearance. Though evidence exists indicating that utricular function is severely if not completely compromised in these animals, it is not yet known whether afferent synapses exist within utricular hair cells of otoconia-deficient mutants. The absence of synapses would be suggestive of a trophic relationship between stimulus-evoked hair cell activation and the afferent synapse. To address this question, we have conducted an ultrastructural survey of utricular sensory epithelia from confirmed het mice. The specific objective was to determine whether utricular hair Cells Made Synaptic contact with afferent neurons. We found that both type I and 11 hair cells from utricles of het mice exhibited afferent synapses that were found at numerous sites distributed throughout the Utricle. These results indicate that afferent synapses within vestibular hair cells do not critically depend upon stimulus-evoked activity. (c) 2006 Elsevier B.V. All rights reserved. C1 Univ Calif Los Angeles, David Geffen Sch Med, Div Head & Neck Surg, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, David Geffen Sch Med, Brain Res Inst, Los Angeles, CA 90095 USA. Univ New Mexico, Hlth Sci Ctr, Dept Neurosci, Albuquerque, NM 87131 USA. NASA, Ames Res Ctr, BioVIS Technol Ctr, Moffett Field, CA 94035 USA. E Carolina Univ, Dept Commun Sci & Disorders, Sch Allied Hlth Sci, Greenville, NC 27858 USA. RP Hoffman, LF (reprint author), Univ Calif Los Angeles, David Geffen Sch Med, Div Head & Neck Surg, Box 951624, Los Angeles, CA 90095 USA. EM lfh@ucla.edu FU NIDCD NIH HHS [DC04477-01, DC05579, R01 DC005776] NR 35 TC 6 Z9 6 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-5955 J9 HEARING RES JI Hear. Res. PD DEC PY 2006 VL 222 IS 1-2 BP 35 EP 42 DI 10.1016/j.heares.2006.05.013 PG 8 WC Audiology & Speech-Language Pathology; Neurosciences; Otorhinolaryngology SC Audiology & Speech-Language Pathology; Neurosciences & Neurology; Otorhinolaryngology GA 117YN UT WOS:000242909300004 PM 17023128 ER PT J AU Ghose, S Working, DC Connell, JW Smith, JG Watson, KA Delozier, DM Sun, YP Lin, Y AF Ghose, S. Working, D. C. Connell, J. W. Smith, J. G., Jr. Watson, K. A. Delozier, D. M. Sun, Y. P. Lin, Y. TI Thermal conductivity of Ultem (TM)/carbon nanofiller blends SO HIGH PERFORMANCE POLYMERS LA English DT Article DE Ultem 1000 (TM); thermal conductivity; extrusion; functionalization of carbon nanotubes ID CARBON-NANOTUBE COMPOSITES; IN-SITU POLYMERIZATION; MATRIX COMPOSITES; NANOCOMPOSITES; NANOFIBERS; POLYETHYLENE; ENHANCEMENT; FABRICATION; FIBERS AB In an effort to improve polymer thermal conductivity (TC), Ultem(TM) 1000 was compounded with nano-fillers of carbon allotropes. As-received and modified multiwalled carbon nanotubes (MWC-NTs), vapor-grown carbon nanofibers (CNF) and expanded graphite (EG) were investigated. Functionalization of MWCNTs was performed to improve the TC compatibility between the resin and MWCNTs. It was postulated that this may provide an improved interface between the MWCNT and the polymer which would result in enhanced TC. The nano-fillers were mixed with Ultem(TM) 1000 in the melt and in solution at concentrations ranging from 5 to 40 wt.%. Ribbons were extruded from the blends to form samples where the nano-fillers were aligned to some degree in the extrusion direction. Samples were also fabricated by compression molding resulting in random orientation of the nano-fillers. Thermal properties of the samples were evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analyzer (TGA). Tensile properties of aligned samples were determined at room temperature. As expected, increased filler loading led to increased modulus and decreased elongation with respect to the neat polymer. The degree of dispersion and alignment of the nano-fillers was determined by high-resolution scanning electron microscopy (HRSEM). The HRSEM of the ribbons revealed that the MWCNTs and CNFs were predominantly aligned in the flow direction. The TC of the samples was measured using a Nanoflash(TM) instrument. Since the MWCNTs and CNF are anisotropic, the TC was expected to be different in the longitudinal (parallel to the nanotube and fiber axis) and transverse (perpendicular to the nanotube and fiber axis) directions. The largest TC improvement was achieved for aligned samples when the measurement was performed in the direction of MWCNT and CNF alignment (i.e. longitudinal axis). Unaligned samples also showed a significant improvement in TC and may be potentially useful in applications when it is not possible to align the nano-filler. The results of this study will be presented. C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Clemson Univ, Dept Chem, Clemson, SC 29634 USA. RP Delozier, DM (reprint author), Natl Inst Aerosp, Hampton, VA 23666 USA. EM john.w.connell@nasa.gov NR 36 TC 30 Z9 31 U1 2 U2 28 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0954-0083 J9 HIGH PERFORM POLYM JI High Perform. Polym. PD DEC PY 2006 VL 18 IS 6 BP 961 EP 977 DI 10.1177/0954008306069133 PG 17 WC Polymer Science SC Polymer Science GA 109EZ UT WOS:000242292000009 ER PT J AU Li, LM Ingersoll, AP Vasavada, AR Simon-Miller, AA Achterberg, RK Ewald, SP Dyudina, UA Porco, CC West, RA Flasar, FM AF Li, Liming Ingersoll, Andrew P. Vasavada, Ashwin R. Simon-Miller, Amy A. Achterberg, Richard K. Ewald, Shawn P. Dyudina, Ulyana A. Porco, Carolyn C. West, Robert A. Flasar, F. Michael TI Waves in Jupiter's atmosphere observed by the Cassini ISS and CIRS instruments SO ICARUS LA English DT Article DE atmospheres; dynamics; Jupiter; atmosphere; planetary dynamics ID SPATIAL-ORGANIZATION; PLANETARY-WAVES; IMAGING SCIENCE; TIME-DEPENDENCE; THERMAL WAVES; GRAVITY-WAVES; HOT-SPOTS; GALILEO; SYSTEM; PROBE AB The Cassini Imaging Science Subsystem (ISS) and Composite Infrared Spectrometer (CIRS) reported a North Equatorial Belt (NEB) wave in Jupiter's atmosphere from optical images [Porco, C.C., and 23 colleagues, 2003. Science 299, 1541-1547] and thermal maps [Flasar, F.M., and 39 colleagues, 2004. Nature 427, 132-135], respectively. The connection between the two waves remained uncertain because the two observations were not simultaneous. Here we report on simultaneous ISS images and CIRS thermal maps that confirm that the NEB wave shown in the ISS ultraviolet (UV1) and strong methane band (MT3) images is correlated with the thermal wave in the CIRS temperature maps, with low temperatures in the CIRS maps (upwelling) corresponding to dark regions in the UV1 images (UV-absorbing particles) and bright regions in the MT3 images (high clouds and haze). The long period of the NEB wave suggests that it is a planetary (Rossby) wave. The combined observations from the ISS and CIRS are utilized to discuss the vertical and meridional propagation of the NEB wave, which offers a possible explanation for why the NEB wave is confined to specific latitudes and altitudes. Further, the ISS UV1 images reveal a circumpolar wave centered at 48.5 degrees S (planetocentric) and probably located in the stratosphere, as suggested by the ISS and CIRS observations. The simultaneous comparison between the ISS and CIRS also implies that the large dark oval in the polar stratosphere of Jupiter discovered in the ISS UV1 images [Porco, C.C., and 23 colleagues, 2003. Science 299, 1541-1547] is the same feature as the warm regions at high northern latitudes in the CIRS 1-mbar temperature maps [Flasar, F.M., and 39. colleagues, 2004. Nature 427, 132-135]. This comparison supports a previous suggestion that the dark oval in the ISS UV1 images is linked to auroral precipitation and heating [Porco, C.C., and 23 colleagues, 2003. Science 299, 1541-1547]. (c) 2006 Elsevier Inc. All rights reserved. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. CICLOPS Space Sci Inst, Boulder, CO USA. RP Li, LM (reprint author), CALTECH, Div Geol & Planetary Sci, Mail Stop 150-21, Pasadena, CA 91125 USA. EM liming@gps.caltech.edu RI Flasar, F Michael/C-8509-2012; Simon, Amy/C-8020-2012 OI Simon, Amy/0000-0003-4641-6186 NR 43 TC 15 Z9 15 U1 0 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 2006 VL 185 IS 2 BP 416 EP 429 DI 10.1016/j.icarus.2006.08.005 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 125MP UT WOS:000243446300008 ER PT J AU Salyk, C Ingersoll, AP Lorre, J Vasavada, A Del Genio, AD AF Salyk, Colette Ingersoll, Andrew P. Lorre, Jean Vasavada, Ashwin Del Genio, Anthony D. TI Interaction between eddies and mean flow in Jupiter's atmosphere: Analysis of Cassini imaging data SO ICARUS LA English DT Article DE Jupiter, atmosphere; atmospheres, dynamics ID ZONAL FLOW; IMAGES; VOYAGER-2 AB Beebe et al. [Beebe, R.F., et al., 1980. Geophys. Res. Lett. 17, 1-4] and Ingersoll et al. [Ingersoll, A.P., et al., 1981. J. Geophys. Res. 86, 8733-8743] used images from Voyagers 1 and 2 to analyze the interaction between zonal winds and eddies in Jupiter's atmosphere. They reported high positive correlation between Jupiter's eddy momentum flux, p (u ' v ') over bar, and the variation of zonal velocity with latitude, d (u) over bar /dy. This correlation a value more than 10% of Jupiter's thermal implied a surprisingly high rate of conversion of energy from eddies to zonal flow: similar to 1.5-3.0 W m(-2), flux emission. However, Sromovsky et al. [Sromovsky, L.A., et al., 1982. J. Atmos. Sci. 39, 1413-1432] argued that possible biases in the analysis could have caused an artificially high correlation. In addition, significant differences in the derived eddy flux between datasets put into question the robustness of any one result. We return to this long-standing puzzle using images of Jupiter from the Cassini flyby of December 2000. Our method is similar to previous analyses, but utilizes an automatic feature tracker instead of the human eye. The number of velocity vectors used in this analysis is over 200,000, compared to the 14,000 vectors used by Ingersoll et al. We also find a positive correlation between (u ' v ') over bar and d (u) over bar /dy and derive a global average power per unit mass, (u ' v ') over bar d (u) over bar /dy, ranging from (7.1-12.3) x 10(-5) W ka(-1). Utilizing Ingersoll et al.'s estimate of the mass per unit area involved in the transport, this would imply a rate of energy conversion of similar to 0.7-1.2 W m(-2). We discuss the implications of this result and employ several tests to demonstrate its robustness. (c) 2006 Elsevier Inc. All rights reserved. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Salyk, C (reprint author), CALTECH, Div Geol & Planetary Sci, MC 150-21, Pasadena, CA 91125 USA. EM csalyk@gps.caltech.edu RI Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 18 TC 48 Z9 48 U1 2 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 2006 VL 185 IS 2 BP 430 EP 442 DI 10.1016/j.icarus.2006.08.007 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 125MP UT WOS:000243446300009 ER PT J AU Stofan, ER Lunine, JI Lopes, R Paganelli, F Lorenz, RD Wood, CA Kirk, R Wall, S Elachi, C Soderblom, LA Ostro, S Janssen, M Radebaugh, J Wye, L Zebker, H Anderson, Y Allison, M Boehmer, R Callahan, P Encrenaz, P Flamini, E Francescetti, G Girn, Y Hamilton, G Hensley, S Johnson, WTK Kelleher, K Muhleman, D Picardi, G Posa, F Roth, L Seu, R Shaffer, S Stiles, B Vetrella, S West, R AF Stofan, E. R. Lunine, J. I. Lopes, R. Paganelli, F. Lorenz, R. D. Wood, C. A. Kirk, R. Wall, S. Elachi, C. Soderblom, L. A. Ostro, S. Janssen, M. Radebaugh, J. Wye, L. Zebker, H. Anderson, Y. Allison, M. Boehmer, R. Callahan, P. Encrenaz, P. Flamini, E. Francescetti, G. Girn, Y. Hamilton, G. Hensley, S. Johnson, W. T. K. Kelleher, K. Muhleman, D. Picardi, G. Posa, F. Roth, L. Seu, R. Shaffer, S. Stiles, B. Vetrella, S. West, R. TI Mapping of Titan: Results from the first Titan radar passes SO ICARUS LA English DT Article DE titan; geological processes; Saturn, satellites; satellites, surfaces ID CASSINI; SURFACE; METHANE; ORIGIN; MAPPER AB The first two swaths collected by Cassini's Titan Radar Mapper were obtained in October of 2004 (Ta) and February of 2005 (T3). The Ta swath provides evidence for cryovolcanic processes, the possible occurrence of fluvial channels and lakes, and some tectonic activity. The T3 swath has extensive areas of dunes and two large impact craters. We interpret the brightness variations in much of the swaths to result from roughness variations caused by fracturing and erosion of Titan's icy surface, with additional contributions from a combination of volume scattering and compositional variations. Despite the small amount of Titan mapped to date, the significant differences between the terrains of the two swaths suggest that Titan is geologically complex. The overall scarcity of impact craters provides evidence that the surface imaged to date is relatively young, with resurfacing by cryovolcanism, fluvial erosion, aeolian erosion, and likely atmospheric deposition of materials. Future radar swaths will help to further define the nature of and extent to which internal and external processes have shaped Titan's surface. (c) 2006 Elsevier Inc. All rights reserved. C1 Proxemy Res, Rectortown, VA 20140 USA. Ist Fis Spazio Interplanetario, I-00133 Rome, Italy. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Planetary Sci Inst, Tucson, AZ 85719 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Stanford Univ, Dept Geophys, Stanford, CA 94305 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Observ Paris, DEMIRM, F-75014 Paris, France. Agenzia Spaziale Italiana, I-00198 Rome, Italy. Univ Naples, Dept Elect Engn, I-80125 Naples, Italy. CALTECH, Pasadena, CA 91125 USA. Univ Roma La Sapienza, Info Com Dept, I-00184 Rome, Italy. Politecn Bari, INFM, I-70126 Bari, Italy. Politecn Bari, Dipartimento Interateneo Fis, I-70126 Bari, Italy. Politecn Bari, INFM, I-70126 Bari, Italy. RP Stofan, ER (reprint author), Proxemy Res, POB 338, Rectortown, VA 20140 USA. EM ellen@proxemy.com RI Lorenz, Ralph/B-8759-2016; Lopes, Rosaly/D-1608-2016 OI Lorenz, Ralph/0000-0001-8528-4644; Lopes, Rosaly/0000-0002-7928-3167 NR 42 TC 35 Z9 35 U1 2 U2 7 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 2006 VL 185 IS 2 BP 443 EP 456 DI 10.1016/j.icarus.2006.07.015 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 125MP UT WOS:000243446300010 ER PT J AU Teanby, NA Fletcher, LN Irwin, PGJ Fouchet, T Orton, GS AF Teanby, N. A. Fletcher, L. N. Irwin, P. G. J. Fouchet, T. Orton, G. S. TI New upper limits for hydrogen halides on Saturn derived from Cassini-CIRS data SO ICARUS LA English DT Article DE Saturn; atmospheres; composition ID ROTOTRANSLATIONAL ABSORPTION-SPECTRA; PROBE MASS-SPECTROMETER; ISO-SWS OBSERVATIONS; LINE PARAMETERS; GIANT PLANETS; JUPITER; TEMPERATURES; PAIRS; HITRAN; ATMOSPHERE AB Far infrared spectra (10-600 cm(-1)) from Cassini's Composite InfraRed Spectrometer (CIRS) were used to determine improved upper limits of hydrogen halides HF, HCl, HBr, and HI in Saturn's atmosphere. Three observations, comprising a total of 3088 spectra, gave 3 sigma upper limits on HF, HCI, HBr, and HI volume mole fractions of 8.0 x 10(-12), 6.7 x 10(-11), 1.3 x 10(-10), and 1.4 x 10(-9), respectively, at the 500 mbar pressure level. These upper limits confirm sub-solar abundances of halide species for HF, HCI, and HBr in Saturn's upper atmosphere-consistent with predictions from thermochemical models and influx of material from meteoroids. Our upper limit for HCI is 16 times lower than the tentative detection at 1.1 x 10(-9) reported by Weisstein and Serabyn [Weisstein, E.W., Serabyn, E., 1996. Icarus 123, 23-36]. These observations are not sensitive to the deep halide abundance, which is expected to be enriched relative to the solar composition. (c) 2006 Elsevier Inc. All rights reserved. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Observ Paris, LESIA, F-92195 Meudon, France. Univ Paris 06, UMR 8109, F-75005 Paris, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Teanby, NA (reprint author), Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. EM teanby@atm.ox.ac.uk RI Fletcher, Leigh/D-6093-2011; Fouchet, Thierry/C-6374-2017; OI Fletcher, Leigh/0000-0001-5834-9588; Fouchet, Thierry/0000-0001-9040-8285; Teanby, Nicholas/0000-0003-3108-5775; Irwin, Patrick/0000-0002-6772-384X NR 41 TC 8 Z9 8 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 2006 VL 185 IS 2 BP 466 EP 475 DI 10.1016/j.icarus.2006.07.011 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 125MP UT WOS:000243446300012 ER PT J AU Kim, JH Kim, SJ Geballe, TR Kim, SS Brown, LR AF Kim, Joo Hyeon Kim, Sang J. Geballe, Thomas R. Kim, Sungsoo S. Brown, Linda R. TI High-resolution spectroscopy of Saturn at 3 microns: CH4, CH3D, C2H2, C2H6, PH3, clouds, and haze SO ICARUS LA English DT Article DE Saturn; atmosphere; infrared observations ID MU-M; VIBRATIONAL RELAXATION; ATMOSPHERE; SPECTRUM; ETHANE; TEMPERATURE; ASSIGNMENTS; TROPOSPHERE; PHOSPHINE; ABUNDANCE AB We report observation and analysis of a high-resolution 2.87-3.54 mu m spectrum of the southern temperate region of Saturn obtained with NIRSPEC at Keck II. The spectrum reveals absorption and emission lines of five molecular species as well as spectral features of haze particles. The v(2) + v(3) band of CH3D is detected in absorption between 2.87 and 2.92 mu m; and we derived from it a mixing ratio approximately consistent with the Infrared Space Observatory result. The v(3) band of C2H2 also is detected in absorption between 2.95 and 3.05 mu m; analysis indicates a sudden drop in the C2H2 mixing ratio at 15 mbar (130 km above the 1 bar level), probably due to condensation in the low stratosphere. The presence of the v(3) + v(9) + v(11) band of C2H6 near 3.07 mu m, first reported by Bjoraker et al. [Bjoraker, G.L., Larson, H.P., Fink, U., 1981. Astrophys. J. 248, 856-862], is confirmed, and a C2H6 condensation altitude of 10 mbar (140 km) in the low stratosphere is determined. We assign weak emission lines within the 3.3 mu m band of CH4 to the v(7) band Of C2H6, and derive a mixing ratio of 9 +/- 4 x 10(-6) for this species. Most of the C2H6 3.3 mu m line emission arises in the altitude range 460-620 km (at similar to mu bar pressure levels), much higher than the 160-370 km range where the 12 mu m thermal molecular line emission of this species arises. At 2.87-2.90 mu m the major absorber is tropospheric PH3. The cloud level determined here and at 3.22-3.54 is 390-460 mbar (similar to 30 km), somewhat higher than found by Kim and Geballe [Kim, S.J., Geballe, T.R., 2005. Icarus 179, 449-458] from analysis of a low resolution spectrum. A broad absorption feature at 2.96 mu m, which might be due to NH3 ice particles in saturnian clouds, is also present. The effect of a haze layer at about 125 km (similar to 12 mbar level) on the 3.20-3.54 mu m spectrum, which was not apparent in the low resolution spectrum, is clearly evident in the high resolution data, and the spectral properties of the haze particles suggest that they are composed of hydrocarbons. (c) 2006 Elsevier Inc. All rights reserved. C1 Kyung Hee Univ, Dept Astron & Space Sci, Yongin 446701, South Korea. Gemini Observ, Hilo, HI 96720 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kim, JH (reprint author), Kyung Hee Univ, Dept Astron & Space Sci, Yongin 446701, South Korea. EM sjkim1@khu.ac.kr RI Kim, Sungsoo/A-8601-2011; Kim, Sang Joon/E-2383-2013 OI Kim, Sungsoo/0000-0002-5570-2160; NR 37 TC 24 Z9 24 U1 1 U2 7 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 EI 1090-2643 J9 ICARUS JI Icarus PD DEC PY 2006 VL 185 IS 2 BP 476 EP 486 DI 10.1016/j.icarus.2006.07.004 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 125MP UT WOS:000243446300013 ER PT J AU Simon-Miller, AA Chanover, NJ Orton, GS Sussman, M Tsavaris, IG Karkoschka, E AF Simon-Miller, Amy A. Chanover, Nancy J. Orton, Glenn S. Sussman, Michael Tsavaris, Irene G. Karkoschka, Erich TI Jupiter's White Oval turns red SO ICARUS LA English DT Article DE Jupiter, atmosphere; atmospheres, dynamics ID ATMOSPHERE; SPOT; VOYAGER-1; FLOW; BC AB Jupiter's remaining White Oval changed color in late 2005 and became noticeably red in early 2006, as reported by amateur observers. We present wind and color analyses from high spatial resolution images taken with the Hubble Space Telescope Advanced Camera for Surveys in April 2006. These images suggest that the recent color change was tied to a strengthening of this storm, as implied by increased vorticity, causing it to become more like the Great Red Spot. From a historical perspective, the current activity may be consistent with the generation of new anticyclones at this latitude in the coming months and years. (c) 2006 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. New Mexico State Univ, Las Cruces, NM 88003 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RP Simon-Miller, AA (reprint author), NASA, Goddard Space Flight Ctr, Code 693-0, Greenbelt, MD 20771 USA. EM amy.simon@nasa.gov RI Simon, Amy/C-8020-2012 OI Simon, Amy/0000-0003-4641-6186 NR 19 TC 19 Z9 19 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 2006 VL 185 IS 2 BP 558 EP 562 DI 10.1016/j.icarus.2006.08.002 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 125MP UT WOS:000243446300019 ER PT J AU Rahmat-Samii, Y Kona, KS Manteghi, M Yueh, S Wilson, WJ Dinard, S Hunter, D AF Rahmat-Samii, Yahya Kona, Keerti S. Manteghi, Majid Yueh, Simon Wilson, William J. Dinard, Steve Hunter, Don TI A novel lightweight dual-frequency dual-polarized sixteen-element stacked patch microstrip array antenna for soil-moisture and sea-surface-salinity missions SO IEEE ANTENNAS AND PROPAGATION MAGAZINE LA English DT Article DE radar polarimetry; polarization; FDTD; microstrip antennas; microstrip arrays; remote sensing ID SAR APPLICATIONS; OCEAN SALINITY; MICROWAVE; BAND AB The main motivation for this paper is to discuss the development of a novel compact and light-weight dual-frequency, dual linearly polarized, high-efficiency, stacked-patch microstrip-array antenna for use in standalone aircraft-based remote sensing applications. Results from simulation, fabrication, and testing of a sixteen-element stacked-patch array antenna, optimized for an L-band frequency of operation, are presented. The design center frequencies were 1.26 GHz and 1.413 GHz with 10 MHz and 25 MHz bandwidths in each band, respectively. Due to the large number of design parameters and demanding design requirements of beam-efficiency, sidelobe levels, and polarization characteristics, particle-swarm optimization (PSO) and Finite-Difference Time-Domain (FDTD) simulations were used for synthesis and analysis. Cancellation techniques, based on symmetry, were applied to the antenna ports, with a custom-built feed network to reduce cross polarization. Simulations and measurement results from a spherical near-field test facility confirmed excellent performance of the array configuration, with a beam efficiency of greater than 90%, isolation better than -35 dB, and cross polarization in the main beam of the array better than -40 dB. From the sixteen-element array simulations and experimental verifications, one of the objectives of the present study is to suggest the possibility of using customized dual-frequency, dual-polarized arrays as potential feeds for reflectors to replace the traditionally used conical horns for future soil-moisture and sea-salinity missions. C1 Univ Calif Los Angeles, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rahmat-Samii, Y (reprint author), Univ Calif Los Angeles, Los Angeles, CA 90095 USA. EM rahmat@ee.ucla.edu; Simon.Yueh@jpl.nasa.gov RI Manteghi, Majid/A-1034-2009 OI Manteghi, Majid/0000-0002-1870-6082 NR 18 TC 9 Z9 9 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1045-9243 EI 1558-4143 J9 IEEE ANTENN PROPAG M JI IEEE Antennas Propag. Mag. PD DEC PY 2006 VL 48 IS 6 BP 33 EP 46 DI 10.1109/MAP.2006.323342 PG 14 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 143TO UT WOS:000244748200007 ER PT J AU Kirkham, H AF Kirkham, Harold TI Dust devils and dust fountains: The measurement challenges SO IEEE INSTRUMENTATION & MEASUREMENT MAGAZINE LA English DT Article ID ELECTRIC-FIELD C1 CALTECH, JPL, Reliabil Technol Off, Pasadena, CA USA. RP Kirkham, H (reprint author), CALTECH, JPL, Reliabil Technol Off, Pasadena, CA USA. EM Harold.Kirkham@jpl.nasa.gov OI Kirkham, Harold/0000-0003-2893-7586 NR 8 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1094-6969 J9 IEEE INSTRU MEAS MAG JI IEEE Instrum. Meas. Mag. PD DEC PY 2006 VL 9 IS 6 BP 48 EP 52 DI 10.1109/MIM.2006.250642 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 110YS UT WOS:000242417800008 ER PT J AU Pandian, JD Baker, L Cortes, G Goldsmith, PF Deshpande, AA Ganesan, R Hagen, J Locke, L Wadefalk, N Weinreb, S AF Pandian, Jagadheep D. Baker, Lynn Cortes, German Goldsmith, Paul F. Deshpande, Avinash A. Ganesan, Rajagopalan Hagen, Jon Locke, Lisa Wadefalk, Niklas Weinreb, Sander TI Low-noise 6-8 GHz receiver SO IEEE MICROWAVE MAGAZINE LA English DT Article C1 Cornell Univ, NAIC, Ithaca, NY 14853 USA. Cornell Univ, Jet Prop Lab, Ithaca, NY 14853 USA. Raman Res Inst, Arecibo Observ, Bangalore, Karnataka, India. NRAO, Arecibo Observ, Socorro, NM USA. Chalmers, Jet Prop Lab, Gothenburg, Sweden. RP Pandian, JD (reprint author), Cornell Univ, NAIC, Ithaca, NY 14853 USA. EM jagadheep@astro.cornell.edu RI Deshpande, Avinash/D-4868-2012; Astronomy & Astrophysics Group, Raman Res Institute/D-4046-2012; Goldsmith, Paul/H-3159-2016 NR 6 TC 21 Z9 21 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1527-3342 J9 IEEE MICROW MAG JI IEEE Microw. Mag. PD DEC PY 2006 VL 7 IS 6 BP 74 EP 84 DI 10.1109/MW-M.2006.250316 PG 11 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 108RA UT WOS:000242255700011 ER PT J AU Kennedy, TF Fasenfest, KD Long, SA Williams, JT AF Kennedy, Timothy F. Fasenfest, Kathleen D. Long, Stuart A. Williams, Jeffery T. TI Modification and control of currents on electrically large wire structures using composite dielectric bead elements SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE current control; cylindrical antennas; dielectric loaded antennas; linear antennas; loaded antennas; monopole antennas; wire antennas ID ANTENNAS AB Increasing the number of antennas for wireless communications, while concealing them within their environment, is an area of great importance as demand for wireless devices increases. One method to achieve this goal is to use the existing conducting objects in an environment as antennas. This requires altering the natural current distribution on conducting objects such that optimal radiation properties can be obtained. In this paper, a composite dielectric bead element is introduced for this purpose on electrically large wire structures. The operation of the bead element is described using transmission line theory, and a wire model of the element is given. Using the wire model, the loading for several electrically large wire structures is designed such that they resonate and radiate similarly to a half-wavelength dipole. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Houston, Dept Elect & Comp Engn, Houston, TX USA. RP Kennedy, TF (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM long@uh.edu; long@uh.edu NR 15 TC 3 Z9 3 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD DEC PY 2006 VL 54 IS 12 BP 3608 EP 3613 DI 10.1109/TAP.2006.886487 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 116PM UT WOS:000242814800011 ER PT J AU Champagne, NJ Wilton, DR Rockway, JD AF Champagne, Nathan J. Wilton, Donald R. Rockway, John D. TI The analysis of thin wires using higher order elements and basis functions SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE higher order elements; higher order basis functions; method of moments (MoM); wire ID CYLINDRICAL-ANTENNA; EXACT FORMULATION; EXACT KERNEL; SINGULARITY AB A method of moments procedure for accurately resolving the currents on arbitrarily-shaped wire structures using higher order basis functions and higher order (curved) wire segments is presented. An advanced integration scheme for straight wires is modified for use on higher order wire segments. The results demonstrate that fewer higher order bases than the usual ten per wavelength may be used. This approach is expected to facilitate efforts to create algorithms for mesh (h-adaptive) and basis function (p-adaptive) adaptive schemes for arbitrarily-shaped wire structures. C1 NASA, Lyndon B Johnson Space Ctr, ESCG, Houston, TX 77258 USA. Univ Houston, Dept Elect & Comp Engn, Houston, TX 77204 USA. Univ Washington, Dept Elect Engn, Seattle, WA 98195 USA. RP Champagne, NJ (reprint author), NASA, Lyndon B Johnson Space Ctr, ESCG, Houston, TX 77258 USA. EM champagn@latech.edu; wilton@uh.edu; john.rockway@gmail.com NR 15 TC 7 Z9 7 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD DEC PY 2006 VL 54 IS 12 BP 3815 EP 3821 DI 10.1109/TAP.2006.886538 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 116PM UT WOS:000242814800035 ER PT J AU Tedesco, M Kim, EJ England, AW De Roo, RD Hardy, JP AF Tedesco, Marco Kim, Edward J. England, Anthony W. De Roo, Roger D. Hardy, Janet P. TI Brightness temperatures of snow melting/refreezing cycles: Observations and modeling using a multilayer dense medium theory-based model SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE Cold Land Processes Experiment (CLPX); dense medium theory; microwave emission; microwave radiometry; remote sensing; snow; wet snow ID DEPTH AB The ability of electromagnetic models to accurately predict microwave emission of a snowpack is complicated by the need to account for, among other things, nonindependent scattering by closely packed snow grains, stratigraphic variations, and the occurrence of wet snow. A multilayer dense medium model can account for the first two effects. While microwave remote sensing is well known to be capable of binary wet/dry discrimination, the ability to model brightness as a function of wetness opens up the possibility of ultimately retrieving a percentage wetness value during such hydrologically significant melting conditions. In this paper, the first application of a multilayer dense medium radiative transfer theory (DMRT) model is proposed to simulate emission from both wet and dry snow during melting and refreezing cycles. Wet snow is modeled as a mixture of ice particles surrounded by a thin film of water embedded in an air background. Melting/ refreezing cycles are studied by means of brightness temperatures at 6.7, 19, and 37 GHz recorded by the University of Michigan Truck-Mounted Radiometer System at the Local Scale Observation Site during the Cold Land Processes Experiment-1 in March 2003. Input parameters to the DMRT model are obtained from snow pit measurements carried out in conjunction with the microwave observations. The comparisons between simulated and measured brightness temperatures show that the electromagnetic model is able to reproduce the brightness temperatures with an average percentage error of 3% (similar to 8 K) and a maximum relative percentage error of around 8% (similar to 20 K). C1 Univ Maryland, NASA, Goddard Space Flight Ctr, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Cold Reg Res & Engn Lab, Hanover, NH 03755 USA. RP Tedesco, M (reprint author), Univ Maryland, NASA, Goddard Space Flight Ctr, Goddard Earth Sci & Technol Ctr, Code 661, Greenbelt, MD 20771 USA. EM mtedesco@umbc.edu RI De Roo, Roger/J-2208-2012; Tedesco, Marco/F-7986-2015 OI De Roo, Roger/0000-0001-8391-2950; NR 20 TC 21 Z9 23 U1 2 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD DEC PY 2006 VL 44 IS 12 BP 3563 EP 3573 DI 10.1109/TGRS.2006.881759 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 110PL UT WOS:000242390700010 ER PT J AU Jain, R Mohan, N Ayyanar, R Button, R AF Jain, Rinkle Mohan, Ned Ayyanar, Rajpandian Button, Robert TI A comprehensive analysis of hybrid phase-modulated converter with current-doubler rectifier and comparison with its center-tapped counterpart SO IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS LA English DT Article; Proceedings Paper CT 34th Annual IEEE Power Electronics Specialists Conference CY JUN 15-19, 2003 CL ACAPULCO, MEXICO SP IEEE, IEEE PELS DE current doubler; phase-modulated converter (PNIC); zero-voltage switching (ZVS) ID DC-DC CONVERTER; REDUCED FILTER REQUIREMENT; FULL ZVS-RANGE; OUTPUT APPLICATIONS AB A hybrid phase-modulated converter (HPMC) is a recent innovation in the family of soft-switching converters. It is a promising solution to most soft-switching issues. The principal bottleneck in achieving higher efficiency with this topology is the secondary side loss-mainly the losses in the transformer and the rectifier. For low-voltage high-current power supplies, the current-doubler rectification of HPMC addresses both the transformer conduction losses and the rectifier losses. The presence of an additional path for quiescent current in this scheme gives rise to a third mode of operation.-There is also the possibility of magnetic integration of all the magnetic components into one, which can cause substantial reduction in magnetic requirements. These facts make the analysis of current doubler important. In this paper, all the operating modes are identified and corresponding equations and equivalent circuits that aid in filter and control design are derived. The zero-voltage-switching (ZVS) characteristics, filter requirement, small-signal transfer characteristics, device ratings, and magnetics size requirement are considered to compare this configuration with its center-tapped counterpart. The current-doubler scheme is found to have superior soft-switching characteristics in that it can achieve ZVS at lighter loads with a much lower peak magnetizing current in the transformer and leakage inductance. Also, a judicious choice of output current ripple can give an overall reduced magnetics requirement. The analyses are verified by simulation and hardware implementation. HPMC is found to be most advantageous for applications with input voltages essentially constant, but the output voltage widely varying, for example in battery chargers and converters with power factor correction front end. C1 Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. Arizona State Univ, Dept Elect Engn, Tempe, AZ 85287 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Jain, R (reprint author), Intel Corp, Hillsboro, OR 97124 USA. EM rinkle.jain@intel.com; mohan@umn.edu; rayyanar@asu.edu; robert.button@grc.nasa.gov NR 14 TC 12 Z9 12 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0278-0046 J9 IEEE T IND ELECTRON JI IEEE Trans. Ind. Electron. PD DEC PY 2006 VL 53 IS 6 BP 1870 EP 1880 DI 10.1109/TIE.2006.885159 PG 11 WC Automation & Control Systems; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Automation & Control Systems; Engineering; Instruments & Instrumentation GA 113ZK UT WOS:000242636300012 ER PT J AU Fung, A Dawson, D Samoska, L Lee, K Gaier, T Kangaslahti, P Oleson, C Denning, A Lau, Y Boll, G AF Fung, Andy Dawson, Douglas Samoska, Lorene Lee, Karen Gaier, Todd Kangaslahti, Pekka Oleson, Charles Denning, Anthony Lau, Yuenie Boll, Greg TI Two-port vector network analyzer measurements in the 218-344- and 356-500-GHz frequency bands SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE coplanar transmission lines; coplanar waveguides (CPWs); measurement; monolithic-microwave integrated-circuit (MMIC) amplifiers ID GHZ; F(T) AB We discuss methods for full two-port vector network analyzer measurements in the 218-344- (using WR3) and 356-500-GHz (using WR2.2) frequency bands. Waveguide test sets (WR3 and WR2.2) utilize Oleson Microwave Laboratories Inc. frequency extenders with the Agilent 8510C network analyzer. On-wafer measurements in the 220-325-GHz band are demonstrated with GGB Industries Inc. coplanar-waveguide probes. This paper primarily reviews the performance capabilities of the WR3 test set and introduces initial calibration results of the WR2.2 test set. For WR3, calibration methods are compared, and dynamic range and frequency extender output power data are presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Oleson Microwave Labs Inc, Morgan Hill, CA 95037 USA. GGB Ind Inc, Naples, FL 34101 USA. RP Fung, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM andy.k.fung@jpl.nasa.gov NR 14 TC 17 Z9 18 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9480 EI 1557-9670 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD DEC PY 2006 VL 54 IS 12 BP 4507 EP 4512 DI 10.1109/TMTT.2006.885919 PN 2 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA 118NM UT WOS:000242949000026 ER PT J AU Barth, JL AF Barth, Janet L. TI Conference comments by the general chairwoman SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Editorial Material C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Barth, JL (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Cester, Andrea/H-1683-2015 OI Cester, Andrea/0000-0001-6583-1735 NR 0 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3066 EP 3068 DI 10.1109/TNS.2006.886817 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400001 ER PT J AU Ladbury, R LaBel, K AF Ladbury, Ray LaBel, Ken TI Scott Kniffin - In memoriam SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Biographical-Item C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ladbury, R (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3077 EP 3077 DI 10.1109/TNS.2006.886821 PN 1 PG 1 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400005 ER PT J AU Layton, P Kniffin, S Guertin, S Swift, G Buchner, S AF Layton, Phil Kniffin, Scott Guertin, Steven Swift, Gary Buchner, Stephen TI SEL induced latent damage, testing, and evaluation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE characterization; latent damage; SEL AB We describe a methodology for evaluating and screening SEL susceptible devices for latent damage. Experimental data and modeling are presented to demonstrate the approach on actual devices. C1 Maxwell Labs Inc, San Diego, CA 92123 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Layton, P (reprint author), Maxwell Labs Inc, San Diego, CA 92123 USA. EM playton@maxwell.com NR 8 TC 2 Z9 2 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3153 EP 3157 DI 10.1109/TNS.2006.886235 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400013 ER PT J AU Sutton, AK Prakash, APG Jun, BG Zhao, EH Bellini, M Pellish, J Diestelhorst, RM Carts, MA Phan, A Ladbury, R Cressler, JD Marshall, PW Marshall, CJ Reed, RA Schrimpf, RD Fleetwood, DM AF Sutton, Akil K. Prakash, A. P. Gnana Jun, Bongim Zhao, Enhai Bellini, Marco Pellish, Jonathan Diestelhorst, Ryan M. Carts, Martin A. Phan, Anthony Ladbury, Ray Cressler, John D. Marshall, Paul. W. Marshall, Cheryl J. Reed, Robert A. Schrimpf, Ronald D. Fleetwood, Daniel M. TI An investigation of dose rate and source dependent effects in 200 GHz SiGe HBTs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE dose enhancement; hardness assurance; low-frequency noise; silicon-germanium (SiGe); hetero-junction bipolar transistor; total ionizing dose ID 1/F NOISE; HARDNESS-ASSURANCE; MOS DEVICES; RADIATION; TRANSISTORS; BUILDUP; OXIDES AB We present an investigation of the observed variations in the total dose tolerance of the emitter-base spacer and shallow trench isolation oxides in a commercial 200 GHz SiGe HBT technology. Proton, gamma, and X-ray irradiations at varying dose rates are found to produce drastically different degradation signatures at the various oxide interfaces. Extraction and analysis of the radiation-induced excess base current, as well as low-frequency noise, are used to probe the underlying physical mechanisms. Two-dimensional calibrated device simulations are employed to correlate the observed results to the spatial distributions of carrier recombination in forward- and inverse-mode operation for both pre- and post-irradiation levels. Possible explanations of our observations are offered and the implications for hardness, assurance testing are discussed. C1 Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Muniz Engn Inc, Houston, TX 77058 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sutton, AK (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. EM asutton@ece.gatech.edu RI Pellish, Jonathan/A-8591-2008; A P, Gnana Prakash/G-8054-2012; Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 22 TC 24 Z9 24 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3166 EP 3174 DI 10.1109/TNS.2006.885382 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400015 ER PT J AU Prakash, APG Sutton, AK Diestelhorst, RM Espinel, G Andrews, J Jun, BG Cressler, JD Marshall, PW Marshall, CJ AF Prakash, A. P. Gnana Sutton, Akil K. Diestelhorst, Ryan M. Espinel, Gustavo Andrews, Joel Jun, Bongim Cressler, John D. Marshall, Paul W. Marshall, Cheryl J. TI The effects of irradiation temperature on the proton response of SiGeHBTs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE interface trapped charge; irradiation; low temperature; proton irradiation; SiGeHBT ID CRYOGENIC TEMPERATURES; INTERFACE TRAPS; GHZ SIGEHBTS; TOLERANCE; TECHNOLOGY; RADIATION; MOSFETS; GAMMA AB We compare, for the first time, the effects of 63 MeV protons on 1st generation and 3rd generation SiGe HBTs irradiated at both liquid nitrogen temperature (77 K) and at room temperature (300 K). The 1st generation SiGe HBTs irradiated at 77 K show less degradation than when irradiated at 300 K. Conversely, the 3rd generation SiGe HBTs exhibits an opposite trend, and the devices irradiated at 77 K show enhanced degradation compared to those irradiated at 300 K. The emitter-base spacer regions for these two SiGe technologies are fundamentally different in construction, and apparently are responsible for the observed differences in temperature-dependent radiation response. At practical circuit biases, both SiGe technology generations show only minimal degradation, for both at 77 K and 300 K exposure, to Mrad dose levels, and are thus potentially useful for electronics applications requiring simultaneous cryogenic temperature operation and significant total dose radiation exposure. C1 Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Prakash, APG (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. EM gprakash@ece.gatech.edu RI A P, Gnana Prakash/G-8054-2012 NR 16 TC 26 Z9 26 U1 2 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3175 EP 3181 DI 10.1109/TNS.2006.886229 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400016 ER PT J AU Bellini, M Jun, BB Chen, TB Cressler, JD Marshall, PW Chen, DK Schrimpf, RD Fleetwood, DM Cai, J AF Bellini, Marco Jun, Bongim Chen, Tianbing Cressler, John D. Marshall, Paul W. Chen, Dakai Schrimpf, Ronald D. Fleetwood, Daniel M. Cai, Jin TI X-ray irradiation and bias effects in fully-depleted and partially-depleted SiGeHBTs fabricated on CMOs-compatible SOI SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE heterojunction bipolar transistors; radiation effects; SiGeHBT; silicon-on-insulator technology; SOI; TCAD ID BIPOLAR-TRANSISTORS AB X-ray total ionizing dose effects in both fully-depleted and partially-depleted SiGe HBT-on-SOI transistors are investigated at room and at cryogenic temperatures for the first time. Devices irradiated in grounded and forward-active mode configurations exhibit a different behavior depending on the collector doping of the device. The degradation produced by 10 keV x-rays is compared to previously reported 63 MeV proton results on the same fully-depleted SiGe HBT-on-SOI devices, showing decreased degradation for proton irradiation. Both collector and substrate bias are shown to affect the two-dimensional nature of the current flow in these devices, resulting in significant differences in the avalanche multiplication characteristics (hence, breakdown voltage) across temperature. C1 Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37232 USA. IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. RP Bellini, M (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. EM bellini@ece.gatech.edu RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 18 TC 9 Z9 10 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3182 EP 3186 DI 10.1109/TNS.2006.885795 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400017 ER PT J AU Najafizadeh, L Bellini, M Prakash, APG Espinel, GA Cressler, JD Marshall, PW Marshall, CJ AF Najafizadeh, Laleh Bellini, Marco Prakash, A. P. Gnana Espinel, Gustavo A. Cressler, John D. Marshall, Paul W. Marshall, Cheryl J. TI Proton tolerance of SiGe precision voltage references for extreme temperature range electronics SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE BiCMOS analog integrated circuits; heterojuction bipolar transistors; proton radiation effects ID 3RD-GENERATION; TRANSISTORS; TECHNOLOGY AB A comprehensive investigation of the effects of proton irradiation on the performance of SiGe BiCMOS precision voltage references intended for extreme environment operational conditions is presented. The voltage reference circuits were designed in two distinct SiGe BiCMOS technology platforms (first generation (50 GHz) and third generation (200 GHz)) in order to investigate the effect of technology scaling. The circuits were irradiated at both room temperature and at 77 K. Measurement results from the experiments indicate that the proton-induced changes in the SiGe bandgap references are minor, even down to cryogenic temperatures, clearly good news for the potential application of SiGe mixed-signal circuits in emerging extreme environments. C1 Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Najafizadeh, L (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. EM laleh@ece.gatech.edu RI A P, Gnana Prakash/G-8054-2012 NR 16 TC 14 Z9 14 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3210 EP 3216 DI 10.1109/TNS.2006.885381 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400021 ER PT J AU Oldham, TR Ladbury, RL Friendlich, M Kim, HS Berg, MD Irwin, TL Seidleck, C LaBel, KA AF Oldham, T. R. Ladbury, R. L. Friendlich, M. Kim, H. S. Berg, M. D. Irwin, T. L. Seidleck, C. LaBel, K. A. TI SEE and TID characterization of an advanced commercial 2Gbit NAND flash nonvolatile memory SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE CMOS; electronics; nonvolatile memory; radiation effects; single event effects; total ionizing dose ID THIN GATE OXIDES; INDUCED LEAKAGE CURRENT; SINGLE HARD ERRORS; ION; BREAKDOWN; CELLS; SRAMS AB An advanced commercial 2Gbit NAND flash memory (90 nm technology, one bit/cell) has been characterized for TID and heavy ion SEE. Results are qualitatively similar to previous flash results in most respects, but we also detected a new dynamic failure mode. C1 QSS Grp Inc, Seabrook, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Muniz Engn Inc, Lanham, MD 20706 USA. RP Oldham, TR (reprint author), QSS Grp Inc, Seabrook, MD 20706 USA. EM Timothy.R.Oldham.1@gsfc.nasa.gov; Raymond.L.Ladbury@nasa.gov; Mark.R.Friendlich.1@gsfc.nasa.gov; hak.kim@gsfc.nasa.gov; Melanie.D.Berg.1@gsfc.nasa.gov; Timothy.L.Irwin.1@gsfc.nasa.gov; Christina.M.Seidleck.1@gsfc.nasa.gov; Ken.Label@nasa.gov NR 25 TC 55 Z9 57 U1 1 U2 11 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3217 EP 3222 DI 10.1109/TNS.2006.885843 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400022 ER PT J AU Tipton, AD Pellish, JA Reed, RA Schrimpf, RD Weller, RA Mendenhall, MH Sierawski, B Sutton, AK Diestelhorst, RM Espinel, G Cressler, JD Marshall, PW Vizkelethy, G AF Tipton, Alan D. Pellish, Jonathan A. Reed, Robert A. Schrimpf, Ronald D. Weller, Robert A. Mendenhall, Marcus H. Sierawski, Brian Sutton, Akil K. Diestelhorst, Ryan M. Espinel, Gustavo Cressler, John D. Marshall, Paul W. Vizkelethy, Gyorgy TI Multiple-bit upset in 130 nm CMOS technology SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE energy deposition cross section; multiple-bit upset (MBU); MRED; single event upset (SEU); SRAM; proton effects ID SINGLE-EVENT UPSETS; NUCLEAR-REACTIONS; ANGULAR-DEPENDENCE; SRAM; SEU AB The probability of proton-induced multiple-bit upset (MBU) has increased in highly-scaled technologies because device dimensions are small relative to particle event track size. Both proton-induced single event upset (SEU) and MBU responses have been shown to vary with angle and energy for certain technologies. This work analyzes SEU and MBU in a 130 nm CMOS SRAM in which the single-event response shows a strong dependence on the angle of proton incidence. Current proton testing methods do not account for device orientation relative to the proton beam and, subsequently, error rate prediction assumes no angular dependencies. Proton-induced MBU is expected to increase as integrated circuits continue to scale into the deep sub-micron regime. Consequently, the application of current testing methods will lead to an incorrect prediction of error rates. C1 Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. Vanderbilt Univ, Inst Space & Def Elect, Nashville, TN 37235 USA. Keck Free Electron Laser Ctr, Nashville, TN 37235 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tipton, AD (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, 221 Kirkland Hall, Nashville, TN 37235 USA. EM alan.tipton@vanderbilt.edu RI Pellish, Jonathan/A-8591-2008; Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 20 TC 53 Z9 58 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3259 EP 3264 DI 10.1109/TNS.2006.884789 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400028 ER PT J AU Sutton, AK Krithivasan, R Marshall, PW Carts, MA Seidleck, C Ladbury, R Cressler, JD Marshall, CJ Currie, S Reed, RA Niu, GF Randall, B Fritz, K McMorrow, D Gilbert, B AF Sutton, Akil K. Krithivasan, Ramkumar Marshall, Paul W. Carts, Martin A. Seidleck, Christina Ladbury, Ray Cressler, John D. Marshall, Cheryl J. Currie, Steve Reed, Robert A. Niu, Guofu Randall, Barbara Fritz, Karl McMorrow, Dale Gilbert, Barry TI SEU error signature analysis of Gbit/s SiGe logic circuits using a pulsed laser microprobe SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE built-in self-test; circuit level hardening; high-speed bit-error rate testing; pulsed laser testing; silicon-germanium (SiGe); single-event effects (SEU) ID SHIFT REGISTERS; HEAVY-ION; TRANSISTORS; RATES AB We present, for the first time, an analysis of the error signatures captured during pulsed laser microprobe testing of high-speed digital SiGe logic circuits. 127-bit shift. registers, configured using various circuit level latch hardening schemes and incorporated into the circuit for radiation effects self test serve as the primary test vehicle. Our results indicate significant variations in the observed upset rate as a function of strike location and latch architecture. Error information gathered on the sensitive transistor nodes within the latches and characteristic upset durations agree well with recently reported heavy-ion microprobe data. These results support the growing credibility in using pulsed laser testing as a lower-cost alternative to heavy-ion microprobe analysis of sensitive device and circuit nodes, as well as demonstrate the efficiency of the autonomous detection and error approach for high speed bit-error rate testing. Implications for SEU hardening in SiGe are addressed and circuit-level and device-level Radiation Hardening By Design recommendations are made. C1 Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. Muniz Engn Inc, Houston, TX 77058 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Mayo Clin, Rochester, MN 55905 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Auburn Univ, Auburn, AL 36849 USA. USN, Res Lab, Washington, DC 20375 USA. RP Sutton, AK (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA. EM asutton@ece.gatech.edu RI Krithivasan, Ramkumar/D-3549-2011 NR 21 TC 10 Z9 10 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3277 EP 3284 DI 10.1109/TNS.2006.886232 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400031 ER PT J AU Laird, JS Hirao, T Onoda, S Itoh, H Johnston, A AF Laird, Jamie S. Hirao, Toshio Onoda, Shinobu Itoh, Hisayoshi Johnston, Allan TI Comparison of above bandgap laesr and MeV ion induced single event transients in high-speed Si photonic devices SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID CHARGE-COLLECTION; HEAVY-ION; GAAS-MESFETS; PULSED-LASER; SILICON; PHOTODETECTORS; MICROBEAM; CIRCUITS; DYNAMICS; ELECTRON AB We illustrate inherent subtle differences between Single Event Transients generated by above bandgap picosecond lasers and MeV heavy ions in a Si junction by comparing transient currents collected on a p-i-n structure using an MeV ion microbeam and picosecond laser with variable spot size. Differences between the ion and laser results are discussed and Synopsis Technology CAD simulations are employed to examine differences in plasma dynamics leading to the observed transient current dependence on initial track conditions. C1 CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. Japan Atom Energy Agcy, Takasaki, Gumma, Japan. RP Laird, JS (reprint author), CALTECH, Jet Prop Lab, NASA, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jamie.s.laird@jpl.nasa.gov RI Laird, Jamie/A-7683-2011 NR 49 TC 12 Z9 12 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3312 EP 3320 DI 10.1109/TNS.2006.886007 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400036 ER PT J AU Krithivasan, R Marshall, PW Nayeem, M Sutton, AK Kuo, WM Haugerud, BM Najafizadeh, L Cressler, JD Carts, MA Marshall, CJ Hansen, DL Jobe, KCM McKay, AL Niu, GF Reed, R Randall, BA Burfield, CA Lindberg, MD Gilbert, BK Daniel, ES AF Krithivasan, Ramkumar Marshall, Paul W. Nayeem, Mustayeen Sutton, Akil K. Kuo, Wei-Min Haugerud, Becca M. Najafizadeh, Laleh Cressler, John D. Carts, Martin A. Marshall, Cheryl J. Hansen, David L. Jobe, Kay-Carol M. McKay, Anthony L. Niu, Guofu Reed, Robert Randall, Barbara A. Burfield, Charles A. Lindberg, Mary Daun Gilbert, Barry K. Daniel, Erik S. TI Application of RHBD techniques to SEU hardening of third-generation SiGe HBT logic circuits SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE current mode logic (CML); heavy ion; heterojunction bipolar transistor (HBT); radiation hardening by design (RHBD); shift register; silicon-germanium (SiGe); single-event upset (SEU); triple-module redundancy (TMR) ID SHIFT REGISTERS; DIGITAL LOGIC; HEAVY-ION; SPEED; TRANSISTORS; TECHNOLOGY; F(T) AB Shift registers featuring radiation-hardening-by-design (RHBD) techniques are realized in IBM 8HP SiGe BiCMOS technology. Both circuit and device-level RHBD techniques are employed to improve the overall SEU immunity of the shift registers. Circuit-level RHBD techniques include dual-interleaving and gated-feedback that achieve SEU mitigation through local latch-level redundancy and correction. In addition, register-level RHBD based on triple-module redundancy (TMR) versions of dual-interleaved and gated-feedback cell shift registers is also realized to gauge the performance improvement offered by TMR. At the device-level, RHBD C-B-E SiGe HBTs with single collector and base contacts and significantly smaller deep trench-enclosed area than standard C-B-E-B-C devices with dual collector and base contacts are used to reduce the upset sensitive area. The SEU performance of these shift registers was then tested using heavy ions and standard bit-error testing methods. The results obtained are compared to the unhardened standard shift register designed with CBEBC SiGe HBTs. The RHBD-enhanced shift registers perform significantly better than the unhardened circuit, with the TMR technique proving very effective in achieving significant SEU immunity. C1 Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. NASA, NRL, Brookneal, VA 24528 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Boeing Space & Intelligence Syst, Los Angeles, CA 90009 USA. Auburn Univ, Auburn, AL 36849 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Mayo Clin & Mayo Fdn, Rochester, MN 55901 USA. RP Krithivasan, R (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. EM ramkumar@ece.gatech.edu RI Krithivasan, Ramkumar/D-3549-2011 NR 14 TC 26 Z9 27 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3400 EP 3407 DI 10.1109/TNS.2006.885379 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400048 ER PT J AU Johnston, AH Miyahira, TF Irom, F Laird, JS AF Johnston, A. H. Miyahira, T. F. Irom, F. Laird, J. S. TI Single-event transients in voltage regulators SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE radiation testing; single-event transient; voltage regulator ID BIPOLAR LINEAR CIRCUITS; SETS AB Single-event transients are investigated for two voltage regulator circuits that are widely used in, space. A circuit-level model is developed that can be used to determine how transients are affected by different circuit application conditions. Internal protection circuits-which are affected by load as well as internal thermal effects-can also be triggered from heavy ions, causing dropouts or shutdown ranging from milliseconds to seconds. Although conventional output transients can be reduced by adding load capacitance, that approach is ineffective for dropouts from protection circuitry. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnston, AH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM allan.h.johnston@jpl.nasa.gov; tetsuo.f.miyahira@jpl.nasa.gov; farokh.irom@jpl.nasa.gov; jamie.laird@jpl.nasa.gov RI Laird, Jamie/A-7683-2011 NR 11 TC 10 Z9 10 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3455 EP 3461 DI 10.1109/TNS.2006.886215 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400056 ER PT J AU Gadlage, MJ Eaton, PH Benedetto, JM Carts, M Zhu, V Turflinger, TL AF Gadlage, Matthew J. Eaton, Paul H. Benedetto, Joseph M. Carts, Marty Zhu, Vivian Turflinger, Thomas L. TI Digital device error rate trends in advanced CMOS technologies SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE heavy ion; ion radiation effects; single-event upset (SEU) ID SINGLE-EVENT TRANSIENTS; HEAVY-ION; LOGIC; MICROELECTRONICS AB In this paper, data are presented from test chips in four technology nodes. With this data, the trends in single event effects as feature sizes shrink are studied. Some of the trends discussed include upset thresholds, shrinking cross sections, multiple bit upsets, and per bit error rate trends. Also included in this paper is some of the first ever heavy ion data from a 65 nm CMOS technology. With data from the 250 nm, 180 run, 90 nm, and 65 nm technology nodes, the past, present, and future of what the radiation effects community has dealt with and will be dealing with when it comes to single event effects is presented. C1 NAVSEA Crane, Crane, IN 47522 USA. Microelect Res & Dev Corp, Albuquerque, NM 87110 USA. ATK Mission Res, Colorado Springs, CO 80919 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Texas Instruments Inc, Dallas, TX 75266 USA. RP Gadlage, MJ (reprint author), NAVSEA Crane, Crane, IN 47522 USA. EM gadlage_m@atd.crane.navy.mil; paul.eaton@micro-rdc.com; joeb@atk.com; mcarts@pop500.gsfc.nasa.gov; vivi@ti.com NR 13 TC 18 Z9 19 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3466 EP 3471 DI 10.1109/TNS.2006.886212 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400058 ER PT J AU Foster, CC O'Neill, PM Kouba, CK AF Foster, Charles C. O'Neill, Patrick M. Kouba, Coy K. TI Monte Carlo simulation of proton upsets in Xilinx Virtex-II FPGA using a position dependent Q(crit) with PROPSET SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE heavy ions; Monte Carlo methods; nuclear radiation effects; proton radiation effects ID SINGLE EVENT UPSET; HEAVY-IONS; SEU; MODEL AB Proton upsets, predicted by the software code, PROPSET, for,the Xilinx Virtex-II FPGA and other devices are presented. PROPSET uses heavy-ion upset data to determine the upset energy threshold at each position within the device's sensitive volume. Sensitivity to the shape and thickness of the sensitive volume, to the choice of Weibull parameters and to model physics are explored. C1 LLC, Foster Consulting Serv, University Pl, WA 98466 USA. Indiana Univ, Cyclotron Facil, Bloomington, IN 47408 USA. NASA, Lyndon B Johnson Space Ctr, Avion Syst Div EV5, Houston, TX 77058 USA. RP Foster, CC (reprint author), LLC, Foster Consulting Serv, University Pl, WA 98466 USA. EM fosterchc@nventure.com; patrick.m.oneill@nasa.gov; coy.kouba-1@nasa.gov NR 28 TC 6 Z9 6 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3494 EP 3501 DI 10.1109/TNS.2006.886233 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400062 ER PT J AU Guertin, SM Nguyen, DN Patterson, JD AF Guertin, Steven M. Nguyen, Duc N. Patterson, Jeffrey D. TI Microdose induced data loss on floating gate memories SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE flash; floating gate; microdose; SEU ID FLASH MEMORIES; CHARGE LOSS; CELLS; IRRADIATION; ION AB Heavy ion irradiation of Hash memories shows loss of stored data. The fluence dependence is indicative of microdose effects. Other qualitative factors identifying the effect as microdose are discussed. The data is presented, and compared to statistical results of a microdose target-based model. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Guertin, SM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM steven.m.guertin@jpl.nasa.gov NR 12 TC 29 Z9 31 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3518 EP 3524 DI 10.1109/TNS.2006.885861 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400066 ER PT J AU Irom, F Farmanesh, F Kouba, CK AF Irom, Farokh Farmanesh, Farhad Kouba, Coy K. TI Single-event upset and scaling trends in new generation of the commercial SOI PowerPC microprocessors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE cyclotron; heavy ion; microprocessors; silicon on insulator ID CHARGE COLLECTION; TECHNOLOGIES; IRRADIATION AB Single-event upset effects from heavy ions are measured for Motorola silicon-on-insulator (SOI) microprocessor with 90 nm feature sizes. The results are compared with previous results for SOI microprocessors with feature sizes of 130 and 180 nm. The cross section of the 90 nm SOI processors is smaller than results for 130 and 180 nm counterparts, but the threshold is about the same. The scaling of the cross section with reduction of feature size and core voltage for SOI microprocessors is discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Irom, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM farokh.irom@jpl.nasa.gov; farhad.f.farmanesh@jpl.nasa.gov; coy.kouba-1@nasa.gov NR 17 TC 6 Z9 6 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3563 EP 3568 DI 10.1109/TNS.2006.884383 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400073 ER PT J AU Berg, M Wang, JJ Ladbury, R Buchner, S Kim, H Howard, J Label, K Phan, A Irwin, T Friendlich, M AF Berg, Melanie Wang, Jih-Jong Ladbury, Ray Buchner, Steve Kim, Hak Howard, Jim LaBel, Ken Phan, Anthony Irwin, Tim Friendlich, Mark TI An analysis of Single Event Upset dependencies on high frequency and architectural implementations within Actel RTAX-S family field programmable gate arrays SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID SEQUENTIAL LOGIC; ERROR RATES; HEAVY-ION AB In order to investigate frequency and -architectural effects on Single Event Upset cross sections within RTAX-S FPGA devices, a novel approach to high speed testing is implemented. Testing was performed at variable speeds ranging from 15 MHz to 150 MHz. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Actel Corp, Actel Technol Dev, Mountain View, CA 94043 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. RP Berg, M (reprint author), NASA, Goddard Space Flight Ctr, Room 052, Greenbelt, MD 20771 USA. EM mdberg@pop500.gsfc.nasa.gov; Jih-Jong.wang@actel.com; rladbury@pop500.gsfc.nasa.gov; sbuchner@pop500.gsfc.nasa.gov; hak.kim@gsfc.nasa.gov; jihoward@pop500.gsfc.nasa.gov; Kenneth.A.LaBel@nasa.gov; aphan@pop400.gsfc.nasa.gov; tirwin@pop500.gsfc.nasa.gov; Mark.R.Friendlich.1@gsfc.nasa.gov NR 10 TC 21 Z9 21 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3569 EP 3574 DI 10.1109/TNS.2006.886043 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400074 ER PT J AU Likar, JJ Bogorad, AL Malko, TR Goodzeit, NE Galofaro, JT Mandell, MJ AF Likar, Justin J. Bogorad, Alexander L. Malko, Thomas R. Goodzeit, Neil E. Galofaro, Joel T. Mandell, Myron J. TI Interaction of charged spacecraft with electric propulsion plume: On orbit data and ground test results SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE electrostatic discharges; photovoltaic space power systems; space vehicle propulsion; surface charging ID ARCJET THRUSTER AB On-orbit observations and ground tests demonstrate interaction between charged spacecraft and electrothermal thruster-generated plasma. On-orbit measurements and test results are presented for plasma diagnostics and solar array performance during long-term exposure of flight solar panel. The long-term performance of a flight 70V 2m x 4 m GEO solar array exposed to a 2 kW arcjet plasma environment was studied. C1 Lockheed Martin Commercial Space Syst, Newtown, PA 18940 USA. Lockheed Martin Commercial Space Syst, Sunnyvale, CA 94089 USA. NASA, Cleveland, OH 44135 USA. Sci Applicat Int Corp, San Diego, CA 92121 USA. RP Likar, JJ (reprint author), Lockheed Martin Commercial Space Syst, Newtown, PA 18940 USA. EM justin.j.likar@lmco.com; alexander.l.bogorad@lmco.com; thomas.r.malko@lmco.com; neil.e.goodzeit1@lmco.com; joel.t.galofaro@nasa.gov; myron.j.mandell@saic.com NR 16 TC 4 Z9 4 U1 2 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3602 EP 3606 DI 10.1109/TNS.2006.885107 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400079 ER PT J AU Onoda, S Hirao, T Laird, JS Mishima, K Kawano, K Itoh, H AF Onoda, S. Hirao, T. Laird, J. S. Mishima, K. Kawano, K. Itoh, H. TI Transient currents generated by heavy ions with hundreds of MeV SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE collimated beam; single event transient (SET); current; transient ion beam induced current (TIBIC) ID CHARGE COLLECTION; ENERGY DEPOSITION; SYSTEM; MICROBEAM; SILICON; DEVICES; TRACKS; DIODES; UPSET AB Single Event Transient (SET) current is one of the most interesting issues for understanding and predicting Single Event Effects (SEEs) in real space environments. Since space radiation consists of high energy heavy ions, estimation of the energy dependence of SET currents is required. In order to estimate this effect, we have developed the Transient Ion Beam Induced Current (TIBIC) system combined with collimated high energy ion beams accelerated by AVF Cyclotron. We have demonstrated the function of TIBIC developed here. Using the newly developed TIBIC system and the Technology Computer Aided Design (TCAD) simulator, the influence of ion energy on SET currents is estimated. C1 Japan Atom Energy Agcy, Takasaki, Gumma 3701292, Japan. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. Univ Electrocommun, Chofu, Tokyo 1828585, Japan. RP Onoda, S (reprint author), Japan Atom Energy Agcy, Takasaki, Gumma 3701292, Japan. EM onoda.shinobu@jaea.go.jp NR 21 TC 13 Z9 14 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3731 EP 3737 DI 10.1109/TNS.2006.885384 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400099 ER PT J AU Becker, HN Elliott, T Alexander, JW AF Becker, Heidi N. Elliott, Tom Alexander, James W. TI Electron-induced displacement damage effects in CCDs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE annealing; CCD; displacement damage; electrons ID DARK CURRENT; TEMPERATURE-DEPENDENCE; SILICON DEVICES; MICROVOLUMES; IRRADIATION; RADIATION; SI AB We compare differences in parametric degradation for CCDs irradiated to the same displacement damage dose with 2-MeV, 10-MeV, and 50-MeV electrons. Charge transfer efficiency degradation was observed to not scale well with non-ionizing energy loss (NIEL) for small signals. Short term annealing of mean dark current in a CCD sample irradiated with 2-MeV electrons at -85C is discussed, as well as additional annealing achieved by warming to temperatures up to and including room temperature. In contrast, charge transfer inefficiency was not observed to anneal following room temperature cycling for the sample irradiated at -85C. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Becker, HN (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Heidi.N.Becker@jpl.nasa.gov; stythe.t.elliott@jpl.nasa.gov; James.W.Alexander@jpl.nasa.gov NR 22 TC 3 Z9 4 U1 2 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3764 EP 3770 DI 10.1109/TNS.2006.886208 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400104 ER PT J AU Laird, JS Onoda, S Hirao, T Becker, H Johnston, A Itoh, H AF Laird, Jamie S. Onoda, Shinobu Hirao, Toshio Becker, Heidi Johnston, Allan Itoh, Hisayoshi TI Effects of gamma and heavy ion damage on the impulse response and pulsed gain of a low breakdown voltage Si avalanche photodiode SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID PROTON IRRADIATION; SILICON DETECTORS; RADIATION-DAMAGE; DEGRADATION; DEPENDENCE; APD AB Effects of displacement and ionization damage on the impulse response of a high-bandwidth low breakdown voltage Si Avalanche Photodiode was investigated using a picosecond laser system. Damage was generated using either Co-60 gamma-irradiation or by scanning the device with an MeV ion microbeam. No shift in the impulse response characteristics and gain was observed for gamma doses as high as 100 kGy(Si). However, dark current measurements for irradiations with biases close to typical operating levels, exhibited enhanced ionization damage orders of magnitude higher than for no bias. Displacement damage introduced by the microbeam was used to differentiate between ionization damage in the guard ring isolation oxide and bulk damage. The absence of any marked change in the impulse response is discussed, as are possible mechanisms for the enhanced ionization damage. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Japan Atom Energy Agcy, Takasaki, Gumma, Japan. RP Laird, JS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jamie.s.laird@jpl.nasa.gov NR 40 TC 9 Z9 9 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2006 VL 53 IS 6 BP 3786 EP 3793 DI 10.1109/TNS.2006.886042 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 121RJ UT WOS:000243174400107 ER PT J AU Kuo, SP Rubinraut, M Popovic, S Bivolaru, D AF Kuo, Spencer P. Rubinraut, Maurice Popovic, Svetozar Bivolaru, Daniel TI Characteristic study of a portable arc microwave plasma torch SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE fuel injector; ignition aide; microwave plasmatorch module; nonequilibrium plasma at atmospheric pressure; scramjet; supersonic combustor ID BIOLOGICAL WARFARE; DECONTAMINATION; IGNITER; AGENTS AB The development of a plasma torch, which carries desirable features to be an ignition aide within a supersonic combustor, is studied. The desirable features include: 1) a microwave adaptor arrangement to couple additional power (from microwave as well as arc discharge) to the plasma torch; 2) an additional port for fuel injection; and 3) compactness (including the power supply), portability, and light weight. The plasma jet generated by this torch is described by the cycle energy of the discharge and by the imaging of its plume under various conditions, supply air pressures, and microwave (on or off) to the torch. This torch system, with its high-voltage discharge, is operated in periodic, (60-Hz) mode. The capacitors in the circuit of the power supply are charged at a line frequency of 60 Hz, resulting in a cyclical discharge. The cycle energy reaches up to 12 J. The microwave electric field has a profound effect on the arc discharge. It intensifies the emission and increases the volume of the arc loop region. It also enhances the electron temperature significantly, as shown by the emission spectroscopy of the torch. The spatial distribution of the microwave electric field outside the nozzle of the torch module is not affected by the supersonic crossfiow, which is a favorable feature for increasing the penetration depth of the torch plume into the supersonic crossfiow in the combustor. C1 Polytech Univ, Dept Elect & Comp Engn, Brooklyn, NY 11201 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Kuo, SP (reprint author), Polytech Univ, Dept Elect & Comp Engn, 6 Metrotech Ctr, Brooklyn, NY 11201 USA. EM skuo@duke.poly.edu; mrubinraut@gmail.com; popovic@physics.odu.edu; d.bivolaru@larc.nasa.gov NR 25 TC 4 Z9 4 U1 0 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2006 VL 34 IS 6 BP 2537 EP 2544 DI 10.1109/TPS.2006.884792 PN 1 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 118DR UT WOS:000242922800010 ER PT J AU Heard, A Pensky, M AF Heard, Astrid Pensky, Marianna TI Confidence intervals for reliability and quantile functions with application to NASA space flight data SO IEEE TRANSACTIONS ON RELIABILITY LA English DT Article DE confidence intervals; generalized gamma distribution; Jeffreys non-informative prior ID GENERALIZED GAMMA-DISTRIBUTION; BINOMIAL PROPORTION; DISTRIBUTIONS AB This paper considers the construction of confidence intervals for a cumulative distribution function F(z), and its inverse quantile function F-1(u), at some fixed points z, and u on the basis of an i.i.d. sample (X) under bar = {X-i}(i=1)(n), where n is relatively small. The sample is modeled as having a flexible, generalized gamma distribution with all three parameters being unknown. Hence, the technique can be considered as an alternative,to non-parametric confidence intervals, when X is a continuous random variable. The confidence intervals are constructed on the basis of Jeffreys noninformative prior. Performance of the resulting confidence intervals is studied via Monte Carlo simulations, and compared to the performance of nonparametric confidence intervals based on binomial proportion. It is demonstrated that the confidence intervals are robust; when data comes from Poisson or geometric distributions, confidence intervals based on a generalized gamma distribution outperform nonparametric confidence intervals. The theory is applied to the assessment of the reliability of the Pad Hypergol Servicing System of the Shuttle Orbiter. C1 Univ Cent Florida, Dept Math, Orlando, FL 32816 USA. NASA, Kennedy Space Ctr, FL USA. RP Heard, A (reprint author), Univ Cent Florida, Dept Math, Orlando, FL 32816 USA. NR 20 TC 3 Z9 3 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9529 J9 IEEE T RELIAB JI IEEE Trans. Reliab. PD DEC PY 2006 VL 55 IS 4 BP 591 EP 601 DI 10.1109/TR.2006.884590 PG 11 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 112SM UT WOS:000242547400004 ER PT J AU Zardus, JD Balazs, GH AF Zardus, J. D. Balazs, G. H. TI Form follows function in mode of attachment for barnacles commensal with sea turtles SO INTEGRATIVE AND COMPARATIVE BIOLOGY LA English DT Meeting Abstract C1 Citadel, Charleston, SC USA. NOAA, Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Honolulu, HI USA. EM john.zardus@citadel.edu NR 0 TC 0 Z9 0 U1 1 U2 3 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1540-7063 J9 INTEGR COMP BIOL JI Integr. Comp. Biol. PD DEC PY 2006 VL 46 SU 1 BP E161 EP E161 PG 1 WC Zoology SC Zoology GA V43YJ UT WOS:000202970100642 ER PT J AU Betts, BJ Binsted, K Jorgensen, C AF Betts, Bradley J. Binsted, Kim Jorgensen, Charles TI Small-vocabulary speech recognition using surface electromyography SO INTERACTING WITH COMPUTERS LA English DT Article DE electromyography; EMG; bioelectric; EMG speech recognition; first responder; pattern recognition; SCBA ID MYOELECTRIC SIGNALS; PROSTHESIS AB We present results of electromyographic (EMG) speech recognition on a small vocabulary of 15 English words. EMG speech recognition holds promise for mitigating the effects of high acoustic noise on speech intelligibility in communication systems, including those used by first responders (a focus of this work). We collected 150 examples per word of single-channel EMG data from a male subject, speaking normally while wearing a firefighter's self-contained breathing apparatus. The signal processing consisted of an activity detector, a feature extractor, and a neural network classifier. Testing produced an overall average correct classification rate on the 15 words of 74% with a 95% confidence interval of (71%, 77%). Once trained, the subject used a classifier as part of a real-time system to communicate to a cellular phone and to control a robotic device. These tasks were performed under an ambient noise level of approximately 95 decibels. We also describe ongoing work on phoneme-level EMG speech recognition. Crown Copyright (c) 2006 Published by Elsevier B.V. All rights reserved. C1 NASA, UH, Astrobiol Inst, Dept Informat & Comp Sci, Honolulu, HI 96744 USA. NASA, Ames Res Ctr, QSS Grp Inc, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Neuro Engn Lab, Moffett Field, CA 94035 USA. RP Binsted, K (reprint author), NASA, UH, Astrobiol Inst, Dept Informat & Comp Sci, Post 317,1680 East West Rd, Honolulu, HI 96744 USA. EM bradley.betts@stanfordalumni.org; binsted@hawaii.edu; cjorgensen@mail.arc.nasa.gov NR 44 TC 12 Z9 12 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0953-5438 J9 INTERACT COMPUT JI Interact. Comput. PD DEC PY 2006 VL 18 IS 6 BP 1242 EP 1259 DI 10.1016/j.intcom.2006.08.012 PG 18 WC Computer Science, Cybernetics; Ergonomics SC Computer Science; Engineering GA 115XF UT WOS:000242766400005 ER PT J AU Hernandez, JL Srikishen, J Erickson, DJ Oglesby, R Irwin, D AF Hernandez, Jose L. Srikishen, Jayanthi Erickson, David J., III Oglesby, Robert Irwin, Daniel TI Regional climate study of Central America using the MM5 modeling system: Results and comparison to observations SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE climate; regional modeling; Central America; diagnostic analysis; land use ID SURFACE-HYDROLOGY MODEL; LAND-SURFACE; GLOBAL PRECIPITATION; ETA-MODEL; PROJECT; IMPLEMENTATION; DROUGHT AB The Mesoscale Modeling system, version 3.6 (MM5) regional modeling system has been applied to Central America and has been evaluated against National Oceanic and Atmospheric Administration/National Climatic Data Center (NOAA/NCDC) daily observations and the Global Precipitation Climatology Project (GPCP) precipitation data. We compare model results and observations for 1997 and evaluate various climate parameters (temperature, wind speed, precipitation and water vapor mixing ratio), emphasizing the differences within the context of the station dependent Geographical features and the land use (LU) categories. At 9 of the 16 analyzed stations the modeled temperature, wind speed and vapor mixing ratio are in agreement with observations with average model-observation differences consistently lower than 25%. MM5 has better performance at stations strongly impacted by monsoon systems, regions typified by low topography in coastal areas and areas characterized by evergreen, broad-leaf and shrub land vegetation types. At four stations the model precipitation is about a factor of 3-5 higher than the observations, while the simulated wind is roughly twice what is observed. These stations include two inland stations characterized by croplands close to water bodied. one coastal station in El Salvador adjacent to a mountain-based cropland area and one station at sea-level. This suggests that the model does not adequately represent the influence of topographic features and water bodies close to these stations. In General, the model agrees reasonably well with measurements and therefore provides an acceptable description of regional climate. The simulations in this study use only two seasonal maps of land cover. The main model discrepancies are likely attributable to the actual annual cycle of land-atmosphere vapor and energy exchange that has a temporal scale of days to weeks. These fluxes are impacted by surface moisture availability, albedo and thermal inertia parameters. Copyright (C) 2006 Royal Meteorological Society. C1 Oak Ridge Natl Lab, Natl Ctr Computat Sci, Climate & Carbon Res Inst, Oak Ridge, TN 37830 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Erickson, DJ (reprint author), Oak Ridge Natl Lab, Natl Ctr Computat Sci, Climate & Carbon Res Inst, Oak Ridge, TN 37831 USA. EM ericksondj@ornl.com NR 33 TC 10 Z9 13 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD DEC PY 2006 VL 26 IS 15 BP 2161 EP 2179 DI 10.1002/joc.1361 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 120LL UT WOS:000243086100003 ER PT J AU Silk, EA Kim, J Kiger, K AF Silk, Eric A. Kim, Jungho Kiger, Ken TI Spray cooling of enhanced surfaces: Impact of structured surface geometry and spray axis inclination SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article DE enhancement; spray cooling; finned surfaces; heat transfer ID CRITICAL HEAT-FLUX; TRANSFER MECHANISM; ROUGHNESS; FC-72 AB Experiments were conducted to study the effects of enhanced surfaces and spray inclination angle (the angle between the surface normal and the axis of symmetry of the spray) on heat transfer during spray cooling. The surface enhancements consisted of cubic pin fins, pyramids, and straight fins. These structures were machined on the top surface of heated copper blocks with 2.0 cm(2) cross-sectional areas. Measurements were also obtained on a heated flat surface to provide baseline data. PF-5060 was used as the working fluid. The spray was produced using a 2 x 2 nozzle array under nominally degassed conditions (chamber pressure of 41.4 kPa) with a volume flux of 0.016 m(3)/m(2) s and a nozzle height of 17 mm. The spray temperature was 20.5 degrees C. For the geometries tested, the straight fins had the largest heat flux enhancement relative to the flat surface, followed by the cubic pin fins and the pyramid surface. Each of these surfaces also indicated an increase in evaporation efficiency at CHF compared to the flat surface. Inclination of the spray axis between 0 degrees and 45 degrees relative to the heater surface normal created a noticeable increase in heat flux compared to the normal position (0 degrees case). A maximum heat flux enhancement of 23% was attained for the flat surface. The straight finned surface had a maximum heat flux enhancement of 75% at an inclination angle of 30 degrees relative to the flat surface in the normal position. However, only a marginal increase (similar to 11%) was observed in comparison to the straight finned surface in the normal position (0 degrees case). (c) 2006 Elsevier Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Thermal Engn Technol Dev Grp, Greenbelt, MD 20771 USA. Univ Maryland, Phase Change Heat Transfer & Multiphase Transport, College Pk, MD 20742 USA. RP Silk, EA (reprint author), NASA, Goddard Space Flight Ctr, Thermal Engn Technol Dev Grp, Code 661, Greenbelt, MD 20771 USA. EM Eric.A.Silk@nasa.gov NR 27 TC 86 Z9 101 U1 5 U2 23 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD DEC PY 2006 VL 49 IS 25-26 BP 4910 EP 4920 DI 10.1016/j.ijheatmasstransfer.2006.05.031 PG 11 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 110RX UT WOS:000242397800020 ER PT J AU Bergeron, NP Hollerman, WA Goedeke, SM Hovater, M Hubbs, W Finchum, A Moore, RJ Allison, SW Edwards, DL AF Bergeron, N. P. Hollerman, W. A. Goedeke, S. M. Hovater, M. Hubbs, W. Finchum, A. Moore, R. J. Allison, S. W. Edwards, D. L. TI Experimental evidence of triboluminescence induced by hypervelocity impact SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article; Proceedings Paper CT 9th Hypervelocity Impact Symposium (HVIS 2005) CY OCT 09-13, 2005 CL Lake Tahoe, CA DE hypervelocity; impact; triboluminescence; luminescence; phosphor AB The emission of light due to crystal fracture, or triboluminescence (TL), is a phenomenon that has been known for centuries. One of the most common examples of TL is the flash created from chewing wintergreen Lifesavers(R). For the last couple of years, the authors have been measuring fluorescence properties of phosphors like zinc sulfide doped with manganese (ZnS:Mn). Preliminary results indicate that impact energies greater than 16 mJ produced measurable TL from ZnS:Mn. Light was generated from the interaction of a dropped mass and a small number of luminescence centers in the ZnS:Mn powder. To extend this research, a two-stage hypervelocity light gas gun located at NASA's Marshall Space Flight Center (MSFC) was used to evaluate equipment and settings that show promise for hypervelocity TL detection. In these experiments, a projectile was accelerated to approximately 5-6 km/s before striking a ZnS:Mn phosphor-coated aluminum plate. This paper will provide an overview into the first experimental evidence of TL emission from ZnS:Mn due to hypervelocity impact. It is hoped that these results will generate interest in future hypervelocity research. (C) 2006 Published by Elsevier Ltd. C1 Univ SW Louisiana, Dept Phys, Lafayette, LA 70504 USA. Oak Ridge Natl Lab, Engn Sci & Technol Div, Oak Ridge, TN 37831 USA. NASA, George C Marshall Space Flight Ctr, Engn Directorate, Huntsville, AL 35812 USA. RP Hollerman, WA (reprint author), Univ SW Louisiana, Dept Phys, Lafayette, LA 70504 USA. EM hollerman@louisiana.edu RI Hollerman, William/F-5943-2011; OI Allison, Stephen/0000-0002-5887-5403 NR 10 TC 30 Z9 30 U1 1 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD DEC PY 2006 VL 33 IS 1-12 BP 91 EP 99 DI 10.1016/j.ijimpeng.2006.09.079 PG 9 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 128PF UT WOS:000243669400013 ER PT J AU Williamsen, JE Evans, SW AF Williamsen, J. E. Evans, S. W. TI Predicting orbital debris shape and orientation effects on spacecraft shield ballistic limits based on characteristic length SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article; Proceedings Paper CT 9th Hypervelocity Impact Symposium (HVIS 2005) CY OCT 09-13, 2005 CL Lake Tahoe, CA DE orbital debris; shape effects; ballistic limits; smooth particle hydrodynamics AB We propose the use of "characteristic length," based on radar cross section, as a metric for comparing the performance of orbital debris impactors of differing shapes, and the use of NASA's standard breakup model (SBM) "flake" shape as the representative particle for predicting orbital debris penetration effects. We also propose the use of a 26-view methodology for examining non-spherical particles such as cylinders, rectangular prisms, octahedrons, etc., with the intent to describe their potential impact orientations while minimizing the number of hydrocode runs needed to develop orientation-dependent ballistic limit curves. Using this methodology and the smooth particle hydrodynamic code (SPHC), we predict the ballistic limit for SBM-based particles against a typical spacecraft dual-wall shield at normal obliquity and velocities of 7, 8, and 12 km/s. Finally, we compare these results with ballistic limits produced by spherical impactors of the same characteristic length as the SBM-based particles. (C) 2006 Elsevier Ltd. All rights reserved. C1 Inst Def Anal, Alexandria, VA 22311 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Williamsen, JE (reprint author), Inst Def Anal, 4850 Mark Ctr Dr, Alexandria, VA 22311 USA. EM jwilliam@ida.org NR 10 TC 4 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD DEC PY 2006 VL 33 IS 1-12 BP 862 EP 871 DI 10.1016/j.ijimpeng.2006.09.084 PG 10 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 128PF UT WOS:000243669400083 ER PT J AU Hong, Y Chiang, YM Liu, Y Hsu, KL Sorooshian, S AF Hong, Y. Chiang, Y. -M. Liu, Y. Hsu, K. -L. Sorooshian, S. TI Satellite-based precipitation estimation using watershed segmentation and growing hierarchical self-organizing map SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID NEURAL-NETWORK; RAINFALL ESTIMATION; PASSIVE MICROWAVE; INFRARED DATA; RESOLUTION; CLOUD; ALGORITHMS; SYSTEM AB This paper outlines the development of a multi-satellite precipitation estimation methodology that draws on techniques from machine learning and morphology to produce high-resolution, short-duration rainfall estimates in an automated fashion. First, cloud systems are identified from geostationary infrared imagery using morphology based watershed segmentation algorithm. Second, a novel pattern recognition technique, growing hierarchical self-organizing map (GHSOM), is used to classify clouds into a number of clusters with hierarchical architecture. Finally, each cloud cluster is associated with co-registered passive microwave rainfall observations through a cumulative histogram matching approach. The network was initially trained using remotely sensed geostationary infrared satellite imagery and hourly ground-radar data in lieu of a dense constellation of polar-orbiting spacecraft such as the proposed global precipitation measurement (GPM) mission. Ground-radar and gauge rainfall measurements were used to evaluate this technique for both warm (June 2004) and cold seasons (December 2004-February 2005) at various temporal (daily and monthly) and spatial (0.04 degrees and 0.25 degrees) scales. Significant improvements of estimation accuracy are found classifying the clouds into hierarchical sub-layers rather than a single layer. Furthermore, 2-year (2003-2004) satellite rainfall estimates generated by the current algorithm were compared with gauge-corrected Stage IV radar rainfall at various time scales over continental United States. This study demonstrates the usefulness of the watershed segmentation and the GHSOM in satellite-based rainfall estimations. C1 Univ Calif Irvine, Dept Civil & Environm Engn, Ctr Hydrometeorol & Remote Sensing, Irvine, CA 92697 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. Natl Taiwan Univ, Dept Bioenvironm Syst Engn, Taipei 10764, Taiwan. Univ S Florida, Coll Marine Sci, St Petersburg, FL 33701 USA. RP Hong, Y (reprint author), Univ Calif Irvine, Dept Civil & Environm Engn, Ctr Hydrometeorol & Remote Sensing, Irvine, CA 92697 USA. EM yanghong@agnes.gsfc.nasa.gov RI Hong, Yang/D-5132-2009; sorooshian, soroosh/B-3753-2008 OI Hong, Yang/0000-0001-8720-242X; sorooshian, soroosh/0000-0001-7774-5113 NR 35 TC 14 Z9 14 U1 1 U2 8 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0143-1161 EI 1366-5901 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD DEC PY 2006 VL 27 IS 23-24 BP 5165 EP 5184 DI 10.1080/01431160600763428 PG 20 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 135VP UT WOS:000244182300003 ER PT J AU Howard, A AF Howard, Andrew TI Multi-robot simultaneous localization and mapping using particle filters SO INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH LA English DT Article; Proceedings Paper CT Conference on Robotics - Science and Systems CY JUN, 2005 CL Cambridge, MA DE multi-robot systems; particle filters; simultaneous localization and mapping ID MOBILE ROBOTS; EXPLORATION; SLAM AB This paper describes an on-line algorith for multi-robot simultaneous localization and mapping (SLAM). The starting point is the single-robot Rao-Blackwellized particle filter described by Hahnel et al., and three key generalizations are made. First, the particle filter is extended to handle multi-robot SLAM problems in which the initial pose of the robots is known (such as occurs when all robots start from the same location). Second, an approximation is introduced to solve the more general problem in which the initial pose of robots is not known a priori (such as occurs when the robots start from widely separated locations). In this latter case, it is assumed that pairs of robots will eventually encounter one another, thereby determining their relative pose. This relative attitude is used to initialize the filter and subsequent observations from both robots are combined into a common map. Third and finally, a method is introduced to integrate observations collected prior to the first robot encounter, using the notion of a virtual robot travelling backwards in time. This novel approach allows one to integrate all data from all robots into a single common map. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Howard, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM abhoward@robotics.jpl.nasa.gov NR 24 TC 122 Z9 127 U1 4 U2 31 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0278-3649 J9 INT J ROBOT RES JI Int. J. Robot. Res. PD DEC PY 2006 VL 25 IS 12 BP 1243 EP 1256 DI 10.1177/0278364906072250 PG 14 WC Robotics SC Robotics GA 116KW UT WOS:000242802800006 ER PT J AU Carney, KS Benson, DJ DuBois, P Lee, R AF Carney, Kelly S. Benson, David J. DuBois, Paul Lee, Ryan TI A phenomenological high strain rate model with failure for ice SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article DE finite element; eulerian; impact; ice; plasticity ID FRICTION; IMPACTS AB Modeling the high velocity impact of ice was a requirement in the safety calculations for the return-to-flight of the Space Shuttle on July 26, 2005. Ice, however, is not a common structural material and commercial finite element programs did not have any appropriate models. A phenomenological model with failure was developed to match experimental ballistic tests. The model has a relatively small number of material constants, most of which have been measured experimentally. A description of the model and comparisons of calculations to experiments are presented. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Calif San Diego, Dept Mech & Aerosp Engn, La Jolla, CA 92093 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Boeing Co, Rotorcraft Div, Ridley Pk, PA 19078 USA. RP Benson, DJ (reprint author), Univ Calif San Diego, Dept Mech & Aerosp Engn, Mail Stop 0411,9500 Gilman Dr, La Jolla, CA 92093 USA. EM dbenson@ucsd.edu NR 27 TC 17 Z9 18 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD DEC PY 2006 VL 43 IS 25-26 BP 7820 EP 7839 DI 10.1016/j.ijsolstr.2006.04.005 PG 20 WC Mechanics SC Mechanics GA 111BM UT WOS:000242425800023 ER PT J AU Rukhovets, LV AF Rukhovets, L. V. TI A posteriori correction of variances of forecast and observation errors SO IZVESTIYA ATMOSPHERIC AND OCEANIC PHYSICS LA English DT Article ID QUALITY-CONTROL C1 NASA, Goddard Space Flight Ctr, SAIC, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD USA. RP Rukhovets, LV (reprint author), NASA, Goddard Space Flight Ctr, SAIC, Greenbelt, MD 20771 USA. EM lrukhovets@gmao.gsfc.nasa.gov NR 8 TC 0 Z9 0 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0001-4338 J9 IZV ATMOS OCEAN PHY+ JI Izv. Atmos. Ocean. Phys. PD DEC PY 2006 VL 42 IS 6 BP 785 EP 790 DI 10.1134/S0001433806060132 PG 6 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 157GB UT WOS:000245705600013 ER PT J AU Stroud, KJ Klaus, DM AF Stroud, Kenneth J. Klaus, David M. TI Spacecraft design considerations for piloted reentry and landing SO JBIS-JOURNAL OF THE BRITISH INTERPLANETARY SOCIETY LA English DT Article DE spacecraft; vestibular; reentry; landing; design; spatial disorientation ID ORTHOSTATIC INTOLERANCE; COUNTERMEASURE; SPACEFLIGHT; PRESSURE; FLIGHT AB With the end of the Space Shuttle era anticipated in this decade and the requirements for the Crew Exploration Vehicle (CEV) now being defined, an opportune window exists for incorporating 'lessons learned' from relevant aircraft and space flight experience into the early stages of designing the next generation of human spacecraft. This includes addressing not only the technological and overall mission challenges, but also taking into account the comprehensive effects that space flight has on the pilot, all of which must be balanced to ensure the safety of the crew. This manuscript presents a unique and timely overview of a multitude of competing, often unrelated, requirements and constraints governing spacecraft design that must be collectively considered in order to ensure the success of future space exploration missions. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Colorado, Boulder, CO 80309 USA. RP Stroud, KJ (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code SF3, Houston, TX 77058 USA. EM kenneth.stroud-l@nasa.gov; klaus@colorado.edu NR 54 TC 0 Z9 0 U1 0 U2 0 PU BRITISH INTERPLANETARY SOC PI LONDON PA 27-29 S LAMBETH RD, LONDON SW8 1SZ, ENGLAND SN 0007-084X J9 JBIS-J BRIT INTERPLA JI JBIS-J. Br. Interplanet. Soc. PD DEC PY 2006 VL 59 IS 12 BP 426 EP 442 PG 17 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Engineering; Astronomy & Astrophysics; Geology GA 103YY UT WOS:000241924300001 ER PT J AU Girerd, AR Meshkat, L Edwards, CD Lee, CH AF Girerd, Andre R. Meshkat, Leila Edwards, Charles D., Jr. Lee, Charles H. TI A model to assess the mars telecommunications network relay robustness SO JBIS-JOURNAL OF THE BRITISH INTERPLANETARY SOCIETY LA English DT Article; Proceedings Paper CT 56th International Astronautical Congress CY OCT 17-21, 2005 CL Fukuoka, JAPAN SP Int Astronaut Federat DE Mars network; telecommunications robustness; proximity link service AB The relatively long mission durations and compatible radio protocols of current and projected Mars orbiters have enabled the gradual development of a heterogeneous constellation providing proximity communication services for surface assets. The current and forecasted capability of this evolving network has reached the point that designers of future surface missions consider complete dependence on it. Such designers, along with those architecting network requirements, have a need to understand the robustness of projected communication service. A model has been created to identify the robustness of the Mars Network as a function of surface location and time. Due to the decade-plus time horizon considered, the network will evolve, with emerging productive nodes and nodes that cease or fail to contribute. The model is a flexible framework to holistically process node information into measures of capability robustness that can be visualized for maximum understanding. Outputs from JPL's Telecom Orbit Analysis Simulation Tool (TOAST) provide global telecom performance parameters for current and projected orbiters. Probabilistic estimates of orbiter fuel life are derived from orbit keeping burn rates, forecasted maneuver tasking, and anomaly resolution budgets. Orbiter reliability is estimated probabilistically. A flexible scheduling framework accommodates the projected mission queue as well as potential alterations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Girerd, AR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM andre.r.girerd@jpl.nasa.gov NR 4 TC 0 Z9 0 U1 1 U2 1 PU BRITISH INTERPLANETARY SOC PI LONDON PA 27-29 S LAMBETH RD, LONDON SW8 1SZ, ENGLAND SN 0007-084X J9 JBIS-J BRIT INTERPLA JI JBIS-J. Br. Interplanet. Soc. PD DEC PY 2006 VL 59 IS 12 BP 443 EP 449 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Engineering; Astronomy & Astrophysics; Geology GA 103YY UT WOS:000241924300002 ER PT J AU Prigent, C Pardo, JR Rossow, WB AF Prigent, Catherine Pardo, Juan R. Rossow, William B. TI Comparisons of the millimeter and submillimeter bands for atmospheric temperature and water vapor soundings for clear and cloudy skies SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY LA English DT Article ID AXIALLY-SYMMETRICAL PARTICLES; RADIATIVE-TRANSFER; SSM/I OBSERVATIONS; LIGHT-SCATTERING; ISCCP; MICROWAVE; SATELLITE; SURFACE; ICE; TRANSMISSION AB Geostationary satellites provide revisiting times that are desirable for nowcasting and observations of severe weather. To overcome the problem of spatial resolution from a geostationary orbit, millimeter to submillimeter wave sounders have been suggested. This study compares the capabilities of various oxygen and water vapor millimeter and submillimeter bands for temperature and water vapor atmospheric profiling at nadir in cloudy situations. It shows the impact of different cloud types on the received signal for the different frequency bands. High frequencies are very sensitive to the cloud ice phase, with potential applications to cirrus characterization. C1 Observ Paris, Lab Etud Rayonnement & Mat Astrophys, CNRS, F-75014 Paris, France. CSIC, Inst Estructura Mat, Dept Astrofis Mol & Infrarroja, E-28006 Madrid, Spain. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Prigent, C (reprint author), Observ Paris, Lab Etud Rayonnement & Mat Astrophys, CNRS, 61,Ave Observ, F-75014 Paris, France. EM catherine.prigent@obspm.fr RI Rossow, William/F-3138-2015 NR 49 TC 13 Z9 13 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1558-8424 J9 J APPL METEOROL CLIM JI J. Appl. Meteorol. Climatol. PD DEC PY 2006 VL 45 IS 12 BP 1622 EP 1633 DI 10.1175/JAM2438.1 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 122WQ UT WOS:000243258600003 ER PT J AU Anantram, MP Svizhenko, A Martinez, A AF Anantram, M. P. Svizhenko, A. Martinez, A. TI Two-dimensional quantum mechanical modeling of nanotransistors (vol 91, pg 2343, 2002) SO JOURNAL OF APPLIED PHYSICS LA English DT Correction C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EEE Dept, Glasgow G12 8LT, Lanark, Scotland. RP Anantram, MP (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 1 TC 9 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2006 VL 100 IS 11 AR 119903 DI 10.1063/1.2393002 PG 1 WC Physics, Applied SC Physics GA 117QG UT WOS:000242887400208 ER PT J AU Cress, CD Landi, BJ Raffaelle, RP Wilt, DM AF Cress, Cory D. Landi, Brian J. Raffaelle, Ryne P. Wilt, David M. TI InGaP alpha voltaic batteries: Synthesis, modeling, and radiation tolerance SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SOLAR-CELLS; DEVICES AB The viability of InGaP diodes coupled with alpha-particle sources as radioisotope power supplies is investigated both theoretically and experimentally. The electrical power output of epitaxially grown InGaP p-type/n-type (p/n) junction diodes coupled with Am-241 and Po-210 alpha-particle sources was measured. A theoretical model was developed that determines the alpha-particle energy deposition profile within an InGaP diode when irradiated by an omnidirectional alpha-particle source. The results of the model illustrate the dramatic influence the radiation source/diode configuration has on the alpha-particle energy deposition profile within a device. Progress has been shown towards increasing the radiation tolerance of the InGaP devices, which included utilizing an intrinsic region and reducing the junction thickness. Introduction of the intrinsic region within a conventional n/p diode to form a n-type/intrinsic/p-type diode enabled the device to withstand a ten times greater fluence of 4.2 MeV alpha particles before decreasing to 50% of its original power output under simulated air mass zero illumination, when compared to an abrupt junction device with the same active region thickness. (c) 2006 American Institute of Physics. C1 Rochester Inst Technol, NanoPower Res Labs, Rochester, NY 14623 USA. Rochester Inst Technol, Microsyst Engn Dept, Rochester, NY 14623 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raffaelle, RP (reprint author), Rochester Inst Technol, NanoPower Res Labs, 85 Lomb Mem Dr, Rochester, NY 14623 USA. EM rprsps@rit.edu RI Cress, Cory/A-8673-2009; OI Cress, Cory/0000-0001-7563-6693 NR 21 TC 11 Z9 16 U1 0 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2006 VL 100 IS 11 AR 114519 DI 10.1063/1.2390623 PG 5 WC Physics, Applied SC Physics GA 117QG UT WOS:000242887400181 ER PT J AU Arkoosh, MR Kagley, AN Anulacion, BF Boylen, DA Sandford, BP Loge, FJ Johnson, LL Collier, TK AF Arkoosh, Mary R. Kagley, Anna N. Anulacion, Bernadita F. Boylen, Deborah A. Sandford, Benjamin P. Loge, Frank J. Johnson, Lyndal L. Collier, Tracy K. TI Disease susceptibility of hatchery Snake River spring-summer Chinook salmon with different juvenile migration histories in the Columbia River SO JOURNAL OF AQUATIC ANIMAL HEALTH LA English DT Article ID VIBRIO-ANGUILLARUM; STEELHEAD; BASIN AB Various methods have been developed to mitigate the effects of dams on juvenile Pacific salmon Oncorhynchus spp. migrating to the Pacific Ocean through the Columbia River basin. In this study, we examined the health of hatchery Snake River spring and summer Chinook salmon relative to two mitigating strategies: dam bypass and transportation (e.g., barging). The health of out-migrants was assessed in terms of the difference in the incidence of mortality among fish, categorically grouped into no-bypass, bypass, and transponation life histories, in response to challenge with the marine pathogen Listonella anguillarum during seawater holding. These three life histories were defined as follows: (1) fish that were not detected at any of the juvenile bypass systems above Bonneville Dam were classified as having a no-bypass life history; (2) fish that were detected at one or more juvenile bypass systems above Bonneville Dam were classified as having a bypass life history; and (3) fish that were barged were classified as having the transportation life history. Barged fish were found to be less susceptible to L. anguillarum than in-river fish-whether bypassed or not-which suggests that transportation may help mitigate the adverse health effects of the hydropower system of the Columbia River basin on Snake River spring-summer Chinook salmon. The findings of this study are not necessarily transferable to other out-migrant stocks in the Columbia River basin, given that only one evolutionarily significant unit, that is, Snake River spring-summer Chinook salmon, was used in this study. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Newport, OR 97365 USA. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Pasco, WA 99301 USA. Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Arkoosh, MR (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, 2030 S Marine Sci Dr, Newport, OR 97365 USA. EM mary.arkoosh@noaa.gov NR 25 TC 9 Z9 9 U1 2 U2 6 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0899-7659 J9 J AQUAT ANIM HEALTH JI J. Aquat. Anim. Health PD DEC PY 2006 VL 18 IS 4 BP 223 EP 231 DI 10.1577/H05-051.1 PG 9 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 131HP UT WOS:000243860000002 PM 26599158 ER PT J AU Gettelman, A Fetzer, EJ Eldering, A Irion, FW AF Gettelman, Andrew Fetzer, Eric J. Eldering, Annmarie Irion, Fredrick W. TI The global distribution of supersaturation in the upper troposphere from the Atmospheric Infrared Sounder SO JOURNAL OF CLIMATE LA English DT Article ID MICROWAVE LIMB SOUNDER; RELATIVE-HUMIDITY; WATER-VAPOR; TROPICAL TROPOPAUSE; ICE SUPERSATURATION; LOWER STRATOSPHERE; SUBVISIBLE CIRRUS; DISTRIBUTION LAW; REGIONS; AIRS/AMSU/HSB AB Satellite data from the Atmospheric Infrared Sounder (AIRS) is analyzed to examine regions of the upper troposphere that are supersaturated: where the relative humidity (RH) is greater than 100%. AIRS data compare well to other in situ and satellite observations of RH and provide daily global coverage up to 200 hPa, though satellite observations of supersaturation are highly uncertain. The climatology of supersaturation is analyzed statistically to understand where supersaturation occurs and how frequently. Supersaturation occurs in humid regions of the upper tropical tropopause near convection 10%-20% of the time at 200 hPa. Supersaturation is very frequent in the extratropical upper troposphere, occurring 20%-40% of the time, and over 50% of the time in storm track regions below the tropopause. The annual cycle of supersaturation is consistent for the similar to 2.5 yr of data analyzed. More supersaturation is seen in the Southern Hemisphere midlatitudes, which may be attributed to higher temperature variance. C1 Natl Ctr Atmospher Res, Boulder, CO 80305 USA. CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. RP Gettelman, A (reprint author), Natl Ctr Atmospher Res, 1850 Table Mesa Dr, Boulder, CO 80305 USA. EM andrew@ucar.edu NR 38 TC 59 Z9 59 U1 2 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PD DEC 1 PY 2006 VL 19 IS 23 BP 6089 EP 6103 DI 10.1175/JCLI3955.1 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 118IB UT WOS:000242934600010 ER PT J AU Gettelman, A Collins, WD Fetzer, EJ Eldering, A Irion, FW Duffy, PB Bala, G AF Gettelman, Andrew Collins, William D. Fetzer, Eric J. Eldering, Annmarie Irion, Fredrick W. Duffy, Phillip B. Bala, Govindasamy TI Climatology of upper-tropospheric relative humidity from the Atmospheric Infrared Sounder and implications for climate SO JOURNAL OF CLIMATE LA English DT Article ID TROPICAL UPPER TROPOSPHERE; WATER-VAPOR; INTRASEASONAL VARIATIONS; AIRS/AMSU/HSB; VALIDATION; CLOUD; SATELLITE; SYSTEMS; MODEL; ICE AB Recently available satellite observations from the Atmospheric Infrared Sounder ( AIRS) are used to calculate relative humidity in the troposphere. The observations illustrate many scales of variability in the atmosphere from the seasonal overturning Hadley-Walker circulation to high-frequency transient variability associated with baroclinic storms with high vertical resolution. The Asian monsoon circulation has a strong impact on upper-tropospheric humidity, with large humidity gradients to the west of the monsoon. The vertical structure of humidity is generally bimodal, with high humidity in the upper and lower troposphere, and a dry middle troposphere. The highest variances in humidity are seen around the midlatitude tropopause. AIRS data are compared to a simulation from a state-of-the-art climate model. The model does a good job of reproducing the mean humidity distribution but is slightly moister than the observations in the middle and upper troposphere. The model has difficultly reproducing many scales of observed variability, particularly in the Tropics. Differences in humidity imply global differences in the top of atmosphere fluxes of similar to 1 W m(-2). C1 CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. Natl Ctr Atmospher Res, Boulder, CO 80305 USA. RP Gettelman, A (reprint author), Natl Ctr Atmospher Res, 1850 Table Mesa Dr, Boulder, CO 80305 USA. EM andrew@ucar.edu RI Collins, William/J-3147-2014 OI Collins, William/0000-0002-4463-9848 NR 32 TC 49 Z9 50 U1 0 U2 12 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PD DEC 1 PY 2006 VL 19 IS 23 BP 6104 EP 6121 DI 10.1175/JCLI3956.1 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 118IB UT WOS:000242934600011 ER PT J AU Yu, B Sun, XH Calebotta, GA Dholakia, GR Meyyappan, M AF Yu, B. Sun, X. H. Calebotta, G. A. Dholakia, G. R. Meyyappan, M. TI One-dimensional germanium nanowires for future electronics SO JOURNAL OF CLUSTER SCIENCE LA English DT Article DE nanowire; germanium; nanoelectronics; nanotechnology ID CHEMICAL-VAPOR-DEPOSITION; SILICON NANOWIRES; ELECTRICAL-TRANSPORT; BUILDING-BLOCKS; CRYSTAL-GROWTH; GE NANOWIRES; CORE-SHELL; FABRICATION; MOSFETS; ARRAYS AB Field- and quantum-effect nanoelectronic devices built on one-dimensional (1-D) chemically synthesized nanostructures are likely among those immediate "successors" of the contemporary top-down silicon CMOS technology for future computing, preserving the spirit of Moore's Law in the post-CMOS era. The nanotechnology-embedded chip technology would emerge in the foreseeable future. However, there exists a large gap between scientific research and semiconductor electronics. Many of the critical issues need to be addressed before nanotechnology becomes truly impacting. Application-driven nanotechnology research becomes more and more important. In this article, with 1-D germanium nanowire as an example, we discuss research efforts at NASA Ames Center for Nanotechnology in directing nanomaterial synthesis and device integration towards implementation in the next-generation miniaturized and intelligent chip systems. The technology goals include (i) low-temperature, low-defect, high-yield Ge nanowire synthesis, (ii) self-assembly of Ge nanowires-on-insulator (GeNOI), (iii) non-contaminating metal catalysts, and (iv) Ge quantum-wire synthesis. The potential applications of 1-D Ge nanowires are very low power, high performance logic FETs that deeply extend CMOS scaling into nanometer regime and extremely low power, fast speed, room-temperatureoperating quantum-wire computing. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Sun, XH (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM xsun@arc.nasa.gov RI Sun, Xuhui /K-5689-2012 NR 43 TC 51 Z9 54 U1 3 U2 18 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1040-7278 J9 J CLUST SCI JI J. Clust. Sci. PD DEC PY 2006 VL 17 IS 4 BP 579 EP 597 DI 10.1007/s10876-006-0081-x PG 19 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 114IE UT WOS:000242659100005 ER PT J AU Nguyen, N Ardema, M AF Nguyen, Nhan Ardema, Mark TI Optimality of hyperbolic partial differential equations with dynamically constrained periodic boundary control - A flow control application SO JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME LA English DT Article ID SYSTEMS AB This paper is concerned with optimal control of a class of distributed-parameter systems governed by first-order quasilinear hyperbolic partial differential equations that arise in optimal control problems of many physical systems such as fluids dynamics and elasto-dynamics. The distributed system is controlled via a forced nonlinear periodic boundary condition that describes a boundary control action. Further the periodic boundary control is subject to a dynamic constraint imposed by a lumped-parameter system governed by ordinary differential equations that model actuator dynamics. The partial differential equations are thus coupled with the ordinary differential equations via the periodic boundary condition. Optimality of this coupled system is investigated using variational principles to seek an adjoint formulation of the optimal control problem. The results are then applied to solve a feedback control problem of the Mach number in a wind tunnel. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Santa Clara Univ, Santa Clara, CA 95053 USA. RP Nguyen, N (reprint author), NASA, Ames Res Ctr, Mail Stop 269-1, Moffett Field, CA 94035 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-0434 J9 J DYN SYST-T ASME JI J. Dyn. Syst. Meas. Control-Trans. ASME PD DEC PY 2006 VL 128 IS 4 BP 946 EP 959 DI 10.1115/1.2362814 PG 14 WC Automation & Control Systems; Instruments & Instrumentation SC Automation & Control Systems; Instruments & Instrumentation GA 112ZH UT WOS:000242566300021 ER PT J AU Mathew, S Das, D Osterman, M Pecht, M Ferebee, R AF Mathew, Sony Das, Diganta Osterman, Michael Pecht, Michael Ferebee, Robin TI Prognostics assessment of aluminum support structure on a printed circuit board SO JOURNAL OF ELECTRONIC PACKAGING LA English DT Article AB This paper presents an analysis of an unexpected failure during vibration and shock life test of an electronic circuit board that has been in use for more than 15 years. During testing, an aluminum bracket used to mount a transistor and provide a path for heat transfer was damaged. Prognostic methods were employed to determine whether the bracket failure could have been predicted prior to the life test. Details of the analytical calculations and modeling results are described in this paper Results show that the failure could have been predicted before actual testing. C1 Univ Maryland, Dept Mech Engn, LCE Elect Prod & Syst Ctr, College Pk, MD 20742 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Mathew, S (reprint author), Univ Maryland, Dept Mech Engn, LCE Elect Prod & Syst Ctr, College Pk, MD 20742 USA. OI Pecht, Michael/0000-0003-1126-8662 NR 8 TC 4 Z9 4 U1 0 U2 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 1043-7398 J9 J ELECTRON PACKAGING JI J. Electron. Packag. PD DEC PY 2006 VL 128 IS 4 BP 339 EP 345 DI 10.1115/1.2351897 PG 7 WC Engineering, Electrical & Electronic; Engineering, Mechanical SC Engineering GA 126GP UT WOS:000243501000006 ER PT J AU Dirmeyer, PA Koster, RD Guo, ZC AF Dirmeyer, Paul A. Koster, Randal D. Guo, Zhichang TI Do global models properly represent the feedback between land and atmosphere? SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID BOUNDARY LAYER INTERACTIONS; SOIL-MOISTURE; COUPLING EXPERIMENT; UNITED-STATES; PART II; PRECIPITATION; SURFACE; IMPACT; VARIABILITY; SIMULATIONS AB The Global Energy and Water Cycle Experiment/Climate Variability and Predictability (GEWEX/ CLIVAR) Global Land-Atmosphere Coupling Experiment (GLACE) has provided an estimate of the global distribution of land-atmosphere coupling strength during boreal summer based on the results from a dozen weather and climate models. However, there is a great deal of variation among models, attributable to a range of sensitivities in the simulation of both the terrestrial and atmospheric branches of the hydrologic cycle. It remains an open question whether any of the models, or the multimodel estimate, reflects the actual pattern and strength of land-atmosphere coupling in the earth's hydrologic cycle. The authors attempt to diagnose this by examining the local covariability of key atmospheric and land surface variables both in models and in those few locations where comparable, relatively complete, long-term measurements exist. Most models do not encompass well the observed relationships between surface and atmospheric state variables and fluxes, suggesting that these models do not represent land - atmosphere coupling correctly. Specifically, there is evidence that systematic biases in near-surface temperature and humidity among all models may contribute to incorrect surface flux sensitivities. However, the multimodel mean generally validates better than most or all of the individual models. Regional precipitation behavior (lagged autocorrelation and predisposition toward maintenance of extremes) between models and observations is also compared. Again a great deal of variation is found among the participating models, but remarkably accurate behavior of the multimodel mean. C1 Ctr Ocean Land Atmosphere Studies, Calverton, MD 20705 USA. NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RP Dirmeyer, PA (reprint author), Ctr Ocean Land Atmosphere Studies, 4041 Powder Mill Rd,Suite 302, Calverton, MD 20705 USA. EM dirmeyer@cola.iges.org RI Koster, Randal/F-5881-2012; Dirmeyer, Paul/B-6553-2016 OI Koster, Randal/0000-0001-6418-6383; Dirmeyer, Paul/0000-0003-3158-1752 NR 30 TC 109 Z9 109 U1 2 U2 35 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X EI 1525-7541 J9 J HYDROMETEOROL JI J. Hydrometeorol. PD DEC PY 2006 VL 7 IS 6 BP 1177 EP 1198 DI 10.1175/JHM532.1 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 125IU UT WOS:000243436400001 ER PT J AU Drouin, BJ Pearson, JC Walters, A Lattanzi, V AF Drouin, Brian J. Pearson, John C. Walters, Adam Lattanzi, Valerio TI THz measurements of propane SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE propane; rotational spectroscopy; submillimeter; THz; internal rotation; planetary atmospheres ID INTERNAL-ROTATION; MICROWAVE SPECTRUM; METHANE; MOLECULES; TITAN AB Propane is present in many planetary atmospheres, as confirmed by vibrational spectroscopy in the infrared wavelengths. As the simplest alkane with a permanent dipole moment, propane has a rotational spectrum. The relatively light atom framework causes the strongest rotational transitions to appear in the submillimeter wavelength range. This fact, as well as the small dipole moment, have prevented the molecule from being observed in the interstellar medium. Telescopes with high sensitivity at high altitude such as the Atacama Large Millimeter Array or above the Earth's atmosphere like the Herschel Space Observatory are likely to be sensitive enough for detection of this species in the interstellar medium, planetary nebulae, hot cores and/or planetary atmospheres. We present the rotational spectra of propane in its ground and first two excited vibrational states, measured through 1.6 THz. The ground state submillimeter spectrum is approximated well by semi-rigid rotor. The submillimeter data has been combined with high resolution centimeter wavelength data to enable analysis of the equivalent dual-hindered rotor torsional substates using a simplified version of a symmetric two-top Hamiltonian. The same model has been applied to the torsionally excited states that experience more large-amplitude motion and require additional tunnelling parameters. (c) 2006 Published by Elsevier Inc. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. Univ Roma La Sapienza, Dept Phys, Rome, Italy. RP Drouin, BJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM brian.j.drouin@jpl.nasa.gov NR 31 TC 16 Z9 17 U1 1 U2 11 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 2006 VL 240 IS 2 BP 227 EP 237 DI 10.1016/j.jms.2006.10.007 PG 11 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 116XZ UT WOS:000242838400008 ER PT J AU Walsh, BM Barnes, NP Reichle, DJ Jiang, SB AF Walsh, Brian M. Barnes, Norman P. Reichle, Donald J. Jiang, Shibin TI Optical properties of Tm(3+) ions in alkali germanate glass SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article DE optical fibers; optical spectroscopy; absorption; lasers; luminescence; upconversion; germanates; rare-earths in glasses; thulium ID RARE-EARTH IONS; ABSORPTION INTENSITIES; SPECTROSCOPY; OPERATION; LIFETIMES; EMISSION; CRYSTALS; ENERGY; LASER; HO3+ AB Tm-doped alkali germanate glass is investigated for use as a laser material. Spectroscopic investigations of bulk Tm-doped germanate glass are reported for the absorption, emission and luminescence decay. Tm:germanate shows promise as a fiber laser when pumped with 0.792 mu m diodes because of low phonon energies. Spectroscopic analysis indicates low non-radiative quenching and pulsed laser performance studies confirm this prediction by showing a quantum efficiency of 1.69. Published by Elsevier B.V. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NP Photon, Tucson, AZ 85747 USA. RP Walsh, BM (reprint author), NASA, Langley Res Ctr, 5 N Dryden St,Mail Stop 468, Hampton, VA 23681 USA. EM b.m.walsh@larc.nasa.gov NR 22 TC 62 Z9 66 U1 2 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD DEC 1 PY 2006 VL 352 IS 50-51 BP 5344 EP 5352 DI 10.1016/j.jnoncrysol.2006.08.029 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 112YW UT WOS:000242565100015 ER PT J AU Yee, HC Sjogreen, B AF Yee, H. C. Sjoegreen, B. TI Nonlinear filtering in compact high-order schemes SO JOURNAL OF PLASMA PHYSICS LA English DT Article; Proceedings Paper CT 19th International Conference on Numerical Simulation of Plasmas/7th Asia Pacific Plasma Theory Conference CY JUL 12-15, 2005 CL Nara, JAPAN SP Natl Inst Fus Sci, Japan Soc Promot Sci AB The adaptive nonlinear filtering approach for shock/turbulence gas dynamics and magnetohydrodynamics (MHD) flows adopted in our previous world is employed in conjunction with compact high-order methods as the spatial base scheme. The objective is to compare the performance of nonlinear filtering in compact high-order schemes with nonlinear filtering in standard central (non-compact) schemes for multiseale problems containing shock waves. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Royal Inst Technol, S-10044 Stockholm, Sweden. RP Yee, HC (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 5 TC 2 Z9 2 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-3778 EI 1469-7807 J9 J PLASMA PHYS JI J. Plasma Phys. PD DEC PY 2006 VL 72 BP 833 EP 836 DI 10.1017/S0022377806004971 PN 6 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 128QO UT WOS:000243673400015 ER PT J AU Hase, F Demoulin, P Sauval, AJ Toon, GC Bernath, PF Goldman, A Hannigan, JW Rinsland, CP AF Hase, F. Demoulin, P. Sauval, A. J. Toon, G. C. Bernath, P. F. Goldman, A. Hannigan, J. W. Rinsland, C. P. TI An empirical line-by-line model for the infrared solar transmittance spectrum from 700 to 5000 cm(-1) SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE infrared spectroscopy; atmospheric trace gases; solar spectrum; radiative transfer; retrieval algorithms ID 5 MU-M; HIGH-RESOLUTION; ATMOS EXPERIMENT; CARBON-MONOXIDE; ABSORPTION; SPACE; SPECTROSCOPY; ABUNDANCE; BALLOON AB An empirical line-by-line model for the infrared solar transmittance spectrum is presented. The model can be incorporated into radiative transfer codes to allow fast calculation of all relevant emission and absorption features in the solar spectrum in the mid-infrared region from 700 to 5000 cm(-1). The transmittance is modelled as a function of the diameter of the field-of-view centered on the solar disk: the line broadening due to solar rotation as well as center-to-limb variations in strength and width are taken into account for stronger lines. Applications of the model presented here are in the fields of terrestrial remote sensing in the mid-infrared spectral region when the sun is used as radiation source or scattered solar radiation contributes to the measured signal and in the fields of atmospheric radiative transfer algorithms which compute the propagation of infrared solar radiation in the terrestrial atmosphere. (c) 2006 Elsevier Ltd. All rights reserved. C1 Forschungszentrum Karlsruhe, Inst Meteorol & Klimaforsch, D-76021 Karlsruhe, Germany. Inst Astrophys & Geophys, B-4000 Liege, Belgium. Observ Royal Belgique, B-1180 Brussels, Belgium. Jet Propuls Lab, Pasadena, CA 91109 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Univ Denver, Dept Phys, Denver, CO 80208 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Hase, F (reprint author), Forschungszentrum Karlsruhe, Inst Meteorol & Klimaforsch, Postfach 3640, D-76021 Karlsruhe, Germany. EM frank.hase@imk.fzk.de RI Bernath, Peter/B-6567-2012; Hase, Frank/A-7497-2013 OI Bernath, Peter/0000-0002-1255-396X; NR 39 TC 37 Z9 38 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 EI 1879-1352 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD DEC PY 2006 VL 102 IS 3 BP 450 EP 463 DI 10.1016/j.jqsrt.2006.02.026 PG 14 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 089JC UT WOS:000240875600012 ER PT J AU Mackenzie, CL Pikanowski, R Mcmillan, DG AF Mackenzie, Clyde L., Jr. Pikanowski, Robert Mcmillan, Donald G. TI Ampelisca amphipod tube mats may enhance abundance of northern quahogs Mercenaria mercenaria in muddy sediments SO JOURNAL OF SHELLFISH RESEARCH LA English DT Article DE Mercenaria; Ampelisca; habitat; pellets; sand; tube mats; predators ID ZOOPLANKTON FECAL PELLETS; COMMUNITY; CLAM; SETTLEMENT; PREDATION; ABDITA; SEA; BAY; ORGANISMS; PATTERNS AB Field surveys in southeastern Raritan Bay and laboratory studies from 1999 to 2005 were conducted to compare the characteristics of mud and sand habitats in relation to the abundance of the northern quahog (Mercenaria mercenaria). In 2000, the population density of quahogs was about 15 times higher in the mud habitat than in the sand habitat. In addition, the mud habitat also had a dense population of the amphipod Ampelisca abdita (about 24,000 m(-2)) associated with it. This species produces mats of tubes over the bottom. The sediment surface of the mud was comprised mostly of fecal pellets, the majority of which was produced by A. abdita. In contrast, the sand habitat did not have A. abdita tubes or much erect surface structure; its sediments were comprised of medium grain sand (phi = 1.17-1.4). In southeastern Raritan Bay, the principal quahog predators are the longwrist hermit crab (Pagurus longicarpus), Atlantic oyster drill (Urosalpinx cinerea), and xanthid mud crabs. Collectively, they were > 7 times more abundant in the sand habitat than in the mud habitat. We suggest that quahogs are abundant in the mud habitat because the presence of the tube mats probably reduces water siltation, encourages settlement of larval quahogs and deters predation on the quahogs. C1 NOAA, James J Howard Marine Sci Lab, NE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Highlands, NJ 07732 USA. RP Mackenzie, CL (reprint author), NOAA, James J Howard Marine Sci Lab, NE Fisheries Sci Ctr, Natl Marine Fisheries Serv, 74 Magruder Rd, Highlands, NJ 07732 USA. EM Clyde.Mackenzie@noaa.gov NR 48 TC 9 Z9 9 U1 1 U2 12 PU NATL SHELLFISHERIES ASSOC PI GROTON PA C/O DR. SANDRA E. SHUMWAY, UNIV CONNECTICUT, 1080 SHENNECOSSETT RD, GROTON, CT 06340 USA SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD DEC PY 2006 VL 25 IS 3 BP 841 EP 847 PG 7 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 116YM UT WOS:000242839700006 ER PT J AU Jones, SM AF Jones, Steven M. TI Aerogel: Space exploration applications SO JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th International Workshop on Sol-Gel Science and Technology (Sol-Gel 2005) CY AUG 21-26, 2005 CL Los Angeles, CA DE aerogel; aerogel applications; space exploration ID SOL-GEL PROCESS; SILICA AEROGEL; CHEMISTRY AB The unique physical properties of aerogel have proven to be enabling to a variety of both flight and proposed space exploration missions. The extremely low density and highly porous nature of aerogel makes it suitable for stopping high velocity particles, as a highly efficient thermal barrier, and as a porous medium for the containment of cryogenic fluids. The use of silica aerogel as a hypervelocity particle capture and return media for the Stardust Mission has drawn the attention of many in the space exploration community. Aerogel is currently being used as the thermal insulation material in the 2003 Mars Exploration Rovers. The SCIM (Sample Collection for the Investigation of Mars) and the STEP (Satellite Test of the Equivalence Principle) Missions are both proposed space exploration missions, in which, the use of aerogel is critical to their overall design and success. Composite materials comprised of silica aerogel and oxide powders are under development for use in a new generation of thermoelectric devices that are planned for use in many future space exploration mission designs. Work is currently ongoing in the development and production of non-silicate and composite aerogels to extend the range of useful applications envisioned for aerogel in future space exploration projects. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jones, SM (reprint author), CALTECH, Jet Prop Lab, MS125-109,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Steven.M.Jones@jpl.nasa.gov NR 24 TC 75 Z9 85 U1 10 U2 73 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0928-0707 J9 J SOL-GEL SCI TECHN JI J. Sol-Gel Sci. Technol. PD DEC PY 2006 VL 40 IS 2-3 BP 351 EP 357 DI 10.1007/s10971-006-7762-7 PG 7 WC Materials Science, Ceramics SC Materials Science GA 089SN UT WOS:000240901100026 ER PT J AU Bacmeister, JT Suarez, MJ Robertson, FR AF Bacmeister, Julio T. Suarez, Max J. Robertson, Franklin R. TI Rain reevaporation, boundary layer-convection interactions, and Pacific rainfall patterns in an AGCM SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INTERTROPICAL CONVERGENCE ZONES; SYNOPTIC-SCALE DISTURBANCES; RELAXED ARAKAWA-SCHUBERT; PART I; MODEL; ITCZ; CLOUDS; PARAMETERIZATION; PRECIPITATION; SIMULATIONS AB Sensitivity experiments with an atmospheric general circulation model (AGCM) show that parameterized rain reevaporation has a large impact on simulated precipitation patterns in the tropical Pacific, especially on the configuration of the model's intertropical convergence zone (ITCZ). Weak reevaporation leads to the formation of a "double ITCZ" during the northern warm season. The double ITCZ is accompanied by strong correlation between precipitation and high-frequency vertical motion in the planetary boundary layer (PBL). Strong reevaporation leads to a better overall agreement of simulated precipitation with observations. The model's double ITCZ bias is reduced. At the same time, correlation between high-frequency (periods < 15 days) vertical motion in the PBL and precipitation is reduced. Experiments with modified physics indicate that evaporative cooling by rain near the PBL top weakens the coupling between precipitation-related heating and vertical motion in high-frequency motions. The strength of high-frequency vertical motions in the PBL was also reduced directly through the introduction of a diffusive cumulus momentum transport (DCMT) parameterization. The DCMT had a visible impact on simulated precipitation in the Tropics but did not reduce the model's double ITCZ bias in all cases. Further analyses of mass and water vapor budgets, as well as vertical motion statistics, in the ITCZ complex, show that time-mean moisture convergence in the southern ITCZ is largely dominated by high-frequency modes, while in the northern ITCZ time-mean moisture convergence contains large contributions from slower modes. This may explain why the simulated southern ITCZ is more susceptible to parameterization changes that alter high-frequency coupling between moist heating and PBL convergence. C1 NASA, GSFC, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, MSFC, Huntsville, AL USA. RP Bacmeister, JT (reprint author), NASA, GSFC, Global Modeling & Assimilat Off, Code 900-2, Greenbelt, MD 20771 USA. EM julio.bacmeister@gsfc.nasa.gov NR 39 TC 64 Z9 66 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC PY 2006 VL 63 IS 12 BP 3383 EP 3403 DI 10.1175/JAS3791.1 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 121CN UT WOS:000243135800016 ER PT J AU Greenfield, DI Marin, R Jensen, S Massion, E Roman, B Feldman, J Scholin, CA AF Greenfield, Dianne I. Marin, Roman, III Jensen, Scott Massion, Eugene Roman, Brent Feldman, Jason Scholin, Christopher A. TI Application of environmental sample processor (ESP) methodology for quantifying Pseudo-nitzschia australis using ribosomal RNA-targeted probes in sandwich and fluorescent in situ hybridization formats SO LIMNOLOGY AND OCEANOGRAPHY-METHODS LA English DT Article ID WHOLE-CELL HYBRIDIZATION; BACILLARIOPHYCEAE; IDENTIFICATION; PHYTOPLANKTON; OLIGONUCLEOTIDE; ENUMERATION; DINOPHYCEAE; DIATOMS; GULF AB In this contribution, we assess the application of methodology used in a novel in situ remote sampling platform, the environmental sample processor ( ESP), for the identification and enumeration of a harmful algal species, the domoic acid - producing diatom Pseudo-nitzschia australis, using 2 molecular assays: a sandwich hybridization assay (SHA) and fluorescent in situ hybridization ( FISH). Both the SHA and FISH assays were initially designed as laboratory-based methods that are now emulated in the ESP. Response of the SHA to a range of concentrations of P. australis using the laboratory (96-well plate) and ESP ( DNA probe array) formats showed that the two were highly correlated. Enumeration of cells filtered and archived for FISH using a manifold designed for laboratory applications agreed well with counts of cells filtered and archived in the ESP at >= 2.5 x 10(4) cells L-1. At lower concentrations, it becomes statistically unlikely to derive a reliable abundance estimate, suggesting that FISH is better suited for qualitative analyses unless the target organism is very abundant. We also assessed the suitability of an oligonucleotide as synthetic target sequence to act as a SHA reagent quality control and internal standard for the plate assay. This was successful, but the probe and/or associated reagents were stable for only similar to 60 days. Our results show that the ESP is capable of detecting P. australis in near real-time and also supports whole-cell archival samples, making it a potentially useful tool for future research and monitoring initiatives. C1 Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. NASA, Jet Prop Lab, Pasadena, CA USA. RP Greenfield, DI (reprint author), Monterey Bay Aquarium Res Inst, 7700 Sandholdt Rd, Moss Landing, CA 95039 USA. NR 44 TC 52 Z9 54 U1 0 U2 15 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA J9 LIMNOL OCEANOGR-METH JI Limnol. Oceanogr. Meth. PD DEC PY 2006 VL 4 BP 426 EP 435 PG 10 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 135KW UT WOS:000244153500002 ER PT J AU Landi, BJ Evans, CM Worman, JJ Castro, SL Bailey, SG Raffaelle, RP AF Landi, Brian J. Evans, Chris M. Worman, James J. Castro, Stephanie L. Bailey, Sheila G. Raffaelle, Ryne P. TI Noncovalent attachment of CdSe quantum dots to single wall carbon nanotubes SO MATERIALS LETTERS LA English DT Article DE carbon nanotube; quantum dot; nanomaterials; solar energy materials ID RAMAN-SCATTERING; SOLAR-CELLS; NANOCRYSTALS; FUNCTIONALIZATION; NANOPARTICLES; CHEMISTRY; PYRENE; CDTE AB Noncovalent attachment of Use quantum dots (QDs) to single wall carbon nanotubes (SWNTs) through an intermediary I-pyrenebutyric acid N-hydroxy-succinimide ester (PBASE) molecule has been performed. The ligand exchange process from trioctylphosphine oxide (TOPO)-capped CdSe to the 4-aminothiophenol (ATP) ligand is supported by solvent solubility, NMR spectroscopy, and IR spectroscopy, with an estimated molecular efficiency > 50:1. Noncovalent coupling of the PBASE molecule causes a redshift in the SWNT interband electronic transitions, consistent with a pi-pi interaction that promotes electron delocalization. TEM analysis after chemical coupling of the CdSe-ATP QDs to the PBASE-SWNTs shows an abundant coverage of QDs along the SWNT bundles. Raman spectra (1.96 eV excitation) of PBASE-SWNTs and the noncovalent product demonstrate that each of the major Raman modes (RBM, D-, G-, or G'-bands) is unaltered by the noncovalent interaction with PBASE or attachment of CdSe QDs, indicating that the structural integrity of the SWNTs is maintained. However, upshifts in the Raman modes are observed, the largest being for the G-band, indicating charge transfer between the SWNTs and attached CdSe QDs. (c) 2006 Elsevier B.V. All rights reserved. C1 Rochester Inst Technol, NanoPower Res Labs, Rochester, NY 14623 USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raffaelle, RP (reprint author), Rochester Inst Technol, NanoPower Res Labs, Rochester, NY 14623 USA. EM rprsps@rit.edu NR 27 TC 30 Z9 30 U1 2 U2 28 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD DEC PY 2006 VL 60 IS 29-30 BP 3502 EP 3506 DI 10.1016/j.matlet.2006.03.057 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 111QN UT WOS:000242469000014 ER PT J AU Ghaffarian, R AF Ghaffarian, Reza TI CCGA packages for space applications SO MICROELECTRONICS RELIABILITY LA English DT Article AB Commercial-off-the-shelf (COTS) area array packaging technologies in high reliability versions are now being considered for applications, including use in a number of NASA electronic systems being utilized for both the Space Shuttle and Mars Rover missions. Indeed, recently a ceramic package version specifically tailored for high reliability applications was used to provide the processing power required for the Spirit and Opportunity Mars Rovers built by NASA-JPL. Both Rovers successfully completed their 3-months mission requirements and continued exploring the Martian surface for many more moths, providing amazing new information on previous environmental conditions of Mars and strong evidence that water exists on Mars. Understanding process, reliability, and quality assurance (QA) indicators for reliability are important for low risk insertion of these newly available packages in high reliability applications. In a previous investigation, thermal cycle test results for a non-functional daisy-chained peripheral ceramic column grid array (CCGA) and its plastic ball grid array (PBGA) version, both having 560 I/Os, were gathered and are presented here. Test results included environmental data for three different thermal cycle regimes (-55/125 degrees C, -55/100 degrees C, and -50/75 degrees C). Detailed information on these-especially failure type for assemblies with high and low solder volumes-are presented. The thermal cycle test procedure followed those recommended by IPC-9701 for tin-lead solder joint assemblies. Its revision A covers guideline thermal cycle requirements for Pb-free solder joints. Key points on this specification are also discussed. In a recent investigation a fully populated CCGA with 717 I/Os was considered for assembly reliability evaluation. The functional package is a field-programmable gate array that has much higher processing power than its previous version. This new package is smaller in dimension, has no interposer, and has a thinner column wrapped with copper for reliability improvement. This paper will also present thermal cycle test results for assemblies of this and its plastic package version with 728 I/Os, both of which were exposed to four different cycle regimes. Two of these cycle profiles are specified by IPC-9701A for tin-lead, namely, -55 to 100 degrees C and -55 to 125 degrees C. One is a cycle profile specified by Mil-Std-883, namely, -65/150 degrees C, generally used for ceramic hybrid packages screening and qualification. The last cycle is in the range of -120 to 85 degrees C, a representative of electronic systems directly exposed to the Martian environment without use in a thermal control enclosure. Per IPC-9701A, test vehicles were built using daisy chain packages and were continuously monitored and/or manually checked for opens at intervals. The effects of many process and assembly variables-including corner staking commonly used for improving resistance to mechanical loading such as drop and vibration loads-were also considered as part of the test matrix. Optical photomicrographs were taken at various thermal cycle intervals to document damage progress and behavior. Representative samples of these are presented along with cross-sectional photomicrographs at higher magnification taken by scanning electron microscopy (SEM) to determine crack propagation and failure analyses for packages. (c) 2006 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91099 USA. RP Ghaffarian, R (reprint author), CALTECH, Jet Propuls Lab, 4800 Oak Grove Dr,MS 125-152, Pasadena, CA 91099 USA. EM Reza.Ghaffrian@JPL.NASA.Gov NR 22 TC 35 Z9 39 U1 0 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0026-2714 J9 MICROELECTRON RELIAB JI Microelectron. Reliab. PD DEC PY 2006 VL 46 IS 12 BP 2006 EP 2024 DI 10.1016/j.microrel.2006.07.094 PG 19 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 097RG UT WOS:000241465400004 ER PT J AU Watts, AL Strohmayer, TE AF Watts, Anna L. Strohmayer, Tod E. TI The energy dependence of burst oscillations from the accreting millisecond pulsar XTE J1814-338 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE binaries : general; stars : individual; XTE J1814-338; stars : neutron; stars : rotation; X-rays : binaries; X-rays : bursts ID X-RAY-BURSTS; NEUTRON-STARS; R-MODES; THERMONUCLEAR FLAMES; RELATIVISTIC STARS; HARMONIC CONTENT; SURFACE-MODES; XTE J1814-338; PHASE LAGS; EMISSION AB The nature of the asymmetry that gives rise to Type I X-ray burst oscillations on accreting neutron stars remains a matter of debate. Of particular interest is whether the burst oscillation mechanism differs between the bursting millisecond pulsars and the non-pulsing systems. One means to diagnose this is to study the energy dependence of the burst oscillations: here we present an analysis of oscillations from 28 bursts observed during the 2003 outburst of the accreting millisecond pulsar XTE J1814-338. We find that the fractional amplitude of the burst oscillations falls with energy, in contrast to the behaviour found by Muno et al. in the burst oscillations from a set of non-pulsing systems. The drop with energy mirrors that seen in the accretion-powered pulsations; in this respect XTE J1814-338 behaves like the other accreting millisecond pulsars. The burst oscillations show no evidence for either hard or soft lags, in contrast to the persistent pulsations, which show soft lags of up to 50 mu s. The fall in amplitude with energy is inconsistent with current surface-mode and simple hotspot models of burst oscillations. We discuss improvements to the models and uncertainties in the physics that might resolve these issues. C1 Max Planck Inst Astrophys, D-85741 Garching, Germany. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. RP Watts, AL (reprint author), Max Planck Inst Astrophys, Karl Schwarzschild Str 1, D-85741 Garching, Germany. EM anna@mpa-garching.mpg.de; stroh@milkyway.gsfc.nasa.gov NR 49 TC 18 Z9 18 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 1 PY 2006 VL 373 IS 2 BP 769 EP 780 DI 10.1111/j.1365-2966.2006.11072.x PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106PT UT WOS:000242113900030 ER PT J AU Rodgers, JR Cebon, D AF Rodgers, John R. Cebon, David TI Materials informatics SO MRS BULLETIN LA English DT Article DE combinatorial materials science; informatics; performance; properties; simulation; structure; theory ID DESIGN AB Global markets are pressuring the materials industries to reduce the time span between materials research and materials development. In particular, current approaches to the development and insertion (deployment) of advanced materials in military systems are too time-intensive and expensive. Despite the large investments in defense systems, insertion is not certain, since materials development is often not linked to the system designer needs, with the results frequently being that the materials do not meet their requirements. There is potentially a high payoff for developing methodologies that will accelerate the insertion of materials, thereby saving millions of investment dollars. All industries engaged in developing advanced materials are searching for new methodologies to solve these problems. Once a new material has been developed, it must be characterized and modeled. Otherwise, components using it cannot be analyzed, and consequently, it cannot be used in engineering products. Therefore, exploiting the full benefits of new (and existing) engineering materials requires specialized informatics tools for data capture, management, analysis, and dissemination. Advances in computing power, coupled with computational modeling and simulation and materials properties databases, will enable materials scientists and engineers to meet these challenges. The articles in this issue of MRS Bulletin show a variety of applications of the methodologies that are employed in using materials informatics approaches to materials and engineering product development. C1 Innovat Mat Technol Inc, Gatineau, PQ J8X 4E1, Canada. Univ Cambridge, Dept Engn, Cambridge CB2 1PZ, England. Tech Univ Denmark, Dept Phys, CAMD, DK-2800 Lyngby, Denmark. NASA, Glenn Res Ctr, Mat & Struct Div, Mech & Lifing Branch, Cleveland, OH 44135 USA. MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Tech Univ Denmark, Dept Chem, DK-2800 Lyngby, Denmark. Duke Univ, Durham, NC 27708 USA. Inst Chem Proc & Environm Technol, Ottawa, ON K1A 0R6, Canada. Univ Tokyo, Inst Solid State Phys, Chiba 2778581, Japan. Tokyo Inst Technol, Midori Ku, Yokohama, Kanagawa 2268503, Japan. Univ Maryland, Dept Mat Sci & Engn, College Pk, MD 20742 USA. IHPC, Singapore 117528, Singapore. RP Rodgers, JR (reprint author), Innovat Mat Technol Inc, 12-B Charles Bagot St, Gatineau, PQ J8X 4E1, Canada. EM jrodgers@innovativematerials.com; dc@eng.cam.ac.uk NR 21 TC 16 Z9 18 U1 2 U2 22 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD DEC PY 2006 VL 31 IS 12 BP 975 EP 980 DI 10.1557/mrs2006.223 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 121MW UT WOS:000243162700014 ER PT J AU Conyers, JL Moore, VC Lackey, M Partha, R Cherukuri, P Hudson, JL Leonard, A Tour, JM Huff, J AF Conyers, J. L. Moore, V. C. Lackey, M. Partha, R. Cherukuri, P. Hudson, J. L. Leonard, A. Tour, J. M. Huff, J. TI Biocompatibility of carbon nanostructures for therapeutic and diagnostic applications SO NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE LA English DT Meeting Abstract C1 Univ Texas, Ctr Hlth Sci, Houston, TX USA. Rice Univ, Houston, TX 77251 USA. NASA, Johnson Space Ctr, Houston, TX USA. OI Tour, James/0000-0002-8479-9328 NR 0 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1549-9634 EI 1549-9642 J9 NANOMED-NANOTECHNOL JI Nanomed.-Nanotechnol. Biol. Med. PD DEC PY 2006 VL 2 IS 4 BP 304 EP 304 DI 10.1016/j.nano.2006.10.111 PG 1 WC Nanoscience & Nanotechnology; Medicine, Research & Experimental SC Science & Technology - Other Topics; Research & Experimental Medicine GA 120VR UT WOS:000243115000110 ER PT J AU Davies, MB Amaro-Seoane, P Bassa, C Dale, J De Angeli, F Freitag, M Kroupa, P Mackey, D Miller, MC Portegies Zwart, S AF Davies, Melvyn B. Amaro-Seoane, Pau Bassa, Cees Dale, Jim De Angeli, Francesca Freitag, Marc Kroupa, Pavel Mackey, Dougal Miller, M. Coleman Portegies Zwart, Simon TI The MODEST questions: Challenges and future directions in stellar cluster research SO NEW ASTRONOMY LA English DT Review DE open clusters and associations : general; globular clusters : general; galaxy : centre; methods : numerical ID SUPERMASSIVE BLACK-HOLES; X-RAY SOURCES; SPACE-TELESCOPE OBSERVATIONS; MAIN-SEQUENCE STARS; SUBDWARF-B-STARS; SURFACE BRIGHTNESS PROFILES; HORIZONTAL-BRANCH STARS; RESIDUAL-GAS EXPULSION; ACTIVE GALACTIC NUCLEI; LARGE-MAGELLANIC-CLOUD AB We present a review of some of the current major challenges in stellar cluster research, including young clusters, globular clusters, and galactic nuclei. Topics considered include: primordial mass segregation and runaway mergers, expulsion of gas from clusters, the production of stellar exotica seen in some clusters (e.g., blue stragglers and extreme horizontal-branch stars), binary populations within clusters, the black-hole population within stellar clusters, the final parsec problem, stellar dynamics around a massive black hole, and stellar collisions. The Modest Questions posed here are the outcome of discussions which took place at the Modest-6A workshop held in Lund, Sweden, in December, 2005. Modest-6A was organised as part of the activities of the Modest Collaboration (see www.manybody.org for further details). (c) 2006 Elsevier B.V. All rights reserved. C1 Lund Univ, Lund Observ, SE-22100 Lund, Sweden. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Potsdam, Germany. Univ Utrecht, Inst Astron, NL-3508 TC Utrecht, Netherlands. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Bonn, Argelander Inst Astron Sternwarte, D-53121 Bonn, Germany. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Lab Gravitat Astrophys, Greenbelt, MD 20771 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1012 WX Amsterdam, Netherlands. Univ Amsterdam, Sect Computat Sci, NL-1012 WX Amsterdam, Netherlands. RP Davies, MB (reprint author), Lund Univ, Lund Observ, Box 43, SE-22100 Lund, Sweden. EM mbd@astro.lu.se NR 170 TC 11 Z9 11 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1076 EI 1384-1092 J9 NEW ASTRON JI New Astron. PD DEC PY 2006 VL 12 IS 3 BP 201 EP 214 DI 10.1016/j.newast.2006.09.004 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 121RY UT WOS:000243175900006 ER PT J AU Eriksen, HK Dickinson, C Lawrence, CR Baccigalupi, C Banday, AJ Gorski, KM Hansen, FK Pierpaoli, E Seiffert, MD AF Eriksen, H. K. Dickinson, C. Lawrence, C. R. Baccigalupi, C. Banday, A. J. Gorski, K. M. Hansen, F. K. Pierpaoli, E. Seiffert, M. D. TI Bayesian foreground analysis with CMB data SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT Workshop on Fundamental Physics with Cosmic Microwave Background Radiation CY MAR 23-25, 2006 CL Arnold & Nable Beckman Ctr, Natl Acad Sci & Engn, Irvine, CA HO Arnold & Nable Beckman Ctr, Natl Acad Sci & Engn DE cosmic microwave background; cosmology : observations; methods : numerical ID ASTROPHYSICAL COMPONENT SEPARATION; MICROWAVE BACKGROUND COMPONENT; PROBE WMAP OBSERVATIONS; POWER SPECTRUM; EMISSION; FASTICA; MAPS; RADIATION; TEMPLATE AB The quality of CMB observations has improved dramatically in the last few years, and will continue to do so in the coming decade. Over a wide range of angular scales, the uncertainty due to instrumental noise is now small compared to the cosmic variance. One may claim with some justification that we have entered the era of precision CMB cosmology. However, some caution is still warranted: The errors due to residual foreground contamination in the CMB power spectrum and cosmological parameters remain largely unquantified, and the effect of these errors on important cosmological parameters such as the optical depth tau and spectral index n(s) is not obvious. A major goal for current CMB analysis efforts must therefore be to develop methods that allow us to propagate such uncertainties from the raw data through to the final products. Here we review a recently proposed method that may be a first step towards that goal: (c) 2006 Elsevier B.V. All rights reserved. C1 Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Univ Oslo, Ctr Math Applicat, N-0316 Oslo, Norway. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. SISSA, ISAS, Astrophys Sector, I-34014 Trieste, Italy. Ist Nazl Fis Nucl, Sez Trieste, I-34014 Trieste, Italy. Univ Heidelberg, Inst Theoret Astrophys, D-69120 Heidelberg, Germany. Max Planck Inst Astrophys, D-85741 Garching, Germany. RP Eriksen, HK (reprint author), Univ Oslo, Inst Theoret Astrophys, POB 1029, N-0315 Oslo, Norway. EM h.k.k.eriksen@astro.uio.no OI Pierpaoli, Elena/0000-0002-7957-8993 NR 27 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD DEC PY 2006 VL 50 IS 11-12 BP 861 EP 867 DI 10.1016/j.newar.2006.09.027 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 122PW UT WOS:000243239900005 ER PT J AU Kogut, A Fixsen, D Fixsen, S Levin, S Limon, M Lowe, L Mirel, P Seiffert, M Singal, J Lubin, P Wollack, E AF Kogut, A. Fixsen, D. Fixsen, S. Levin, S. Limon, M. Lowe, L. Mirel, P. Seiffert, M. Singal, J. Lubin, P. Wollack, E. TI ARCADE: Absolute radiometer for cosmology, astrophysics, and diffuse emission SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT Workshop on Fundamental Physics with Cosmic Microwave Background Radiation CY MAR 23-25, 2006 CL Arnold & Nable Beckman Ctr, Natl Acad Sci & Engn, Irvine, CA HO Arnold & Nable Beckman Ctr, Natl Acad Sci & Engn DE cosmology; cosmic microwave background; instrumentation ID CENTIMETER WAVELENGTHS; BACKGROUND-RADIATION; HOT-MODEL; UNIVERSE; SIGNATURES; MATTER; REIONIZATION; TEMPERATURE; DISTORTIONS; INSTRUMENT AB The absolute radiometer for cosmology, astrophysics, and diffuse emission (ARCADE) is a balloon-borne instrument designed to measure the temperature of the cosmic microwave background at centimeter wavelengths. ARCADE searches for deviations from a blackbody spectrum resulting from energy releases in the early universe. Long-wavelength distortions in the CMB spectrum are expected in all viable cosmological models. Detecting these distortions or showing that they do not exist is an important step for understanding the early universe. We describe the ARCADE instrument design, current status, and future plans. (c) 2006 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. RP Kogut, A (reprint author), NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA. EM alanj.kogut@nasa.gov RI Kogut, Alan/D-6293-2012; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Limon, Michele/0000-0002-5900-2698 NR 24 TC 16 Z9 16 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD DEC PY 2006 VL 50 IS 11-12 BP 925 EP 931 DI 10.1016/j.newar.2006.09.023 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 122PW UT WOS:000243239900015 ER PT J AU Jones, WC Ade, PAR Bock, JJ Bond, JR Borrill, J Boscaleri, A Cabella, P Contaldi, CR Crill, BP de Bernardis, P De Gasperis, G de Oliveira-Costa, A De Troia, G Di Stefano, G Hivon, E Jaffe, AH Kisner, TS Lange, AE MacTavish, CJ Masi, S Mauskopf, PD Melchiorri, A Montroy, TE Natoli, P Netterfield, CB Pascale, E Piacentini, F Pogosyan, D Polenta, G Prunet, S Ricciardi, S Romeo, G Ruhl, JE Santini, P Tegmark, M Veneziani, M Vittorio, N AF Jones, W. C. Ade, P. A. R. Bock, J. J. Bond, J. R. Borrill, J. Boscaleri, A. Cabella, P. Contaldi, C. R. Crill, B. P. de Bernardis, P. De Gasperis, G. de Oliveira-Costa, A. De Troia, G. Di Stefano, G. Hivon, E. Jaffe, A. H. Kisner, T. S. Lange, A. E. MacTavish, C. J. Masi, S. Mauskopf, P. D. Melchiorri, A. Montroy, T. E. Natoli, P. Netterfield, C. B. Pascale, E. Piacentini, F. Pogosyan, D. Polenta, G. Prunet, S. Ricciardi, S. Romeo, G. Ruhl, J. E. Santini, P. Tegmark, M. Veneziani, M. Vittorio, N. TI Observations of the temperature and polarization anisotropies with BOOMERANG 2003 SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT Workshop on Fundamental Physics with Cosmic Microwave Background Radiation CY MAR 23-25, 2006 CL Arnold & Nable Beckman Ctr, Natl Acad Sci & Engn, Irvine, CA HO Arnold & Nable Beckman Ctr, Natl Acad Sci & Engn DE cosmology; observations; cosmic microwave background; polarization ID ANGULAR POWER SPECTRUM; MICROWAVE; FLIGHT; MAPS AB The BOOMERANG experiment completed its final long duration balloon (LDB) flight over Antarctica in January 2003. The focal plane was upgraded to accommodate four sets of 145 GHz polarization sensitive bolometers (PSBs), identical to those to be flown on the Planck HFI instrument. Approximately, 195 hours of science observations were obtained during this flight, including 75 hours distributed over 1.84% of the sky and an additional 120 hours concentrated on a region covering 0.22% of the sky. We derive the angular power spectra of the cosmic microwave background (emu) temperature and polarization anisotropies from these data. The temperature anisotropies are detected with high signal to noise on angular scales ranging from several degrees to similar to 10 arcminutes. The curl-free (EE) component is detected at similar to 4.8 sigma, and a two-sigma upper limit on the curl (BB) component of 8.6 mu K-2 is obtained on scales corresponding to similar to 0.5 degrees. Both the temperature and polarization anisotropies are found to be consistent with a concordance Lambda CDM cosmology that is seeded by adiabatic density perturbations. In addition to the CMB observations, BOOMERANG03 surveyed a similar to 300 square degree region centered on the Galactic plane. These observations represent the first light for polarization sensitive bolometers, which are currently operational in two South-Pole based polarimeters, as well as Planck HFI, at frequencies ranging from 100 to 350 GHz (3 mm to 850 pm). (c) 2006 Elsevier B.V. All rights reserved. C1 CALTECH, Dept Phys, Pasadena, CA 91125 USA. Univ Cardiff Wales, Sch Phys & Astron, Cardiff, Wales. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 1A1, Canada. LBNL, Computat Res Div, Berkeley, CA USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. CNR, IFAC, Florence, Italy. Univ Roma Tor Vergata, Dipartimento Fis, I-00173 Rome, Italy. Univ London Imperial Coll Sci & Technol, Theoret Phys Grp, London, England. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. MIT, Dept Phys, Cambridge, MA 02139 USA. Inst Nazl Geofis & Vulcanol, Rome, Italy. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA. Univ Toronto, Dept Phys, Toronto, ON, Canada. Ist Nazl Fis Nucl, Sez Roma 1, Rome, Italy. Ist Nazl Fis Nucl, Sez Roma 2, Rome, Italy. Univ Toronto, Dept Astron & Astrophys, Toronto, ON, Canada. Univ Alberta, Dept Phys, Edmonton, AB, Canada. Inst Astrophys, F-75014 Paris, France. RP Jones, WC (reprint author), CALTECH, Dept Phys, Pasadena, CA 91125 USA. EM wcj@astro.caltech.edu RI Jaffe, Andrew/D-3526-2009; de Gasperis, Giancarlo/C-8534-2012; OI Piacentini, Francesco/0000-0002-5444-9327; de Gasperis, Giancarlo/0000-0003-2899-2171; Masi, Silvia/0000-0001-5105-1439; de Bernardis, Paolo/0000-0001-6547-6446; Hivon, Eric/0000-0003-1880-2733; ROMEO, Giovanni/0000-0002-5535-7803; Polenta, Gianluca/0000-0003-4067-9196; Ricciardi, Sara/0000-0002-3807-4043; Santini, Paola/0000-0002-9334-8705 NR 14 TC 6 Z9 6 U1 2 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD DEC PY 2006 VL 50 IS 11-12 BP 945 EP 950 DI 10.1016/j.newar.2006.09.014 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 122PW UT WOS:000243239900018 ER PT J AU Kogut, A Chuss, DT Fixsen, D Hinshaw, GF Limon, M Moseley, SH Phillips, N Sharp, E Wollack, EJ U-Yen, K Cao, N Stevenson, T Hsieh, W Devlin, M Dicker, S Semisch, C Irwin, K AF Kogut, A. Chuss, D. T. Fixsen, D. Hinshaw, G. F. Limon, M. Moseley, S. H. Phillips, N. Sharp, E. Wollack, E. J. U-Yen, K. Cao, N. Stevenson, T. Hsieh, W. Devlin, M. Dicker, S. Semisch, C. Irwin, K. TI PAPPA: Primordial anisotropy polarization pathfinder array SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT Workshop on Fundamental Physics with Cosmic Microwave Background Radiation CY MAR 23-25, 2006 CL Arnold & Nable Beckman Ctr, Natl Acad Sci & Engn, Irvine, CA HO Arnold & Nable Beckman Ctr, Natl Acad Sci & Engn DE cosmology; cosmic microwave background; polarization; instrumentation AB The primordial anisotropy polarization pathfinder array (PAPPA) is a balloon-based instrument to measure the polarization of the cosmic microwave background and search for the signal from gravity waves excited during an inflationary epoch in the early universe. PAPPA will survey a 20 x 20 patch at the North Celestial Pole using 32 pixels in 3 passbands centered at 89, 212, and 302 GHz. Each pixel uses MEMS switches in a superconducting microstrip transmission line to combine the phase modulation techniques used in radio astronomy with the sensitivity of transition-edge superconducting bolometers. Each switched circuit modulates the incident polarization on a single detector, allowing nearly instantaneous characterization of the Stokes I, Q, and U parameters. We describe the instrument design and status. (c) 2006 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Global Sci & Technol, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MEI Technol, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Penn, Philadelphia, PA 19104 USA. Natl Inst Stand & Technol, Boulder, CO USA. RP Kogut, A (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM alan.j.kogut@nasa.gov RI Moseley, Harvey/D-5069-2012; Kogut, Alan/D-6293-2012; Chuss, David/D-8281-2012; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Limon, Michele/0000-0002-5900-2698 NR 7 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD DEC PY 2006 VL 50 IS 11-12 BP 1009 EP 1014 DI 10.1016/j.newar.2006.09.024 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 122PW UT WOS:000243239900026 ER PT J AU Ghrist, M Ellis, M Bean, D Kurwitz, C Best, F AF Ghrist, Melissa Ellis, Mike Bean, David Kurwitz, Cable Best, Frederick TI Microgravity phase separation for the Rankine cycle SO NUCLEAR TECHNOLOGY LA English DT Article DE phase separation; microgravity; Rankine cycle AB Phase separation in reduced gravity continues to be an obstacle for the National Aeronautics and Space Administrations' power programs. Phase separation would be necessary for the use of a Rankine power conversion cycle in microgravity. The vortex phase separator invented by Texas A&M University may be implemented in a microgravity Rankine cycle for successful phase separation. With the known characteristics of the separator/ inventory control system, the Texas A&M University vortex phase separator can be operated successfully for a wide variety of uses in microgravity. The separator operating principle and envelope, test performance data, and inventory monitoring system are described. C1 Texas A&M Univ, Dept Nucl Engn, College Stn, TX 77843 USA. Texas A&M Univ, NASA, Ctr Space Power, College Stn, TX 77843 USA. RP Ghrist, M (reprint author), Texas A&M Univ, Dept Nucl Engn, College Stn, TX 77843 USA. EM melissa.ghrist@gmail.com; fbest@tamu.edu NR 6 TC 0 Z9 0 U1 1 U2 5 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD DEC PY 2006 VL 156 IS 3 BP 282 EP 288 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 110AF UT WOS:000242350000004 ER PT J AU DeGuzman, VS Lee, CC Deamer, DW Vercoutere, WA AF DeGuzman, Veronica S. Lee, Clarence C. Deamer, David W. Vercoutere, Wenonah A. TI Sequence-dependent gating of an ion channel by DNA hairpin molecules SO NUCLEIC ACIDS RESEARCH LA English DT Article ID SOLID-STATE NANOPORE; ALPHA-HEMOLYSIN; POLYMER TRANSLOCATION; BROWNIAN DYNAMICS; SINGLE; ACID; PORE; DISCRIMINATION; KINETICS; ELECTROPHORESIS AB DNA hairpins produce ionic current signatures when captured by the alpha-hemolysin nano-scale pore under conditions of single molecule electrophoresis. Gating patterns produced by individual DNA hairpins when captured can be used to distinguish differences of a single base pair or even a single nucleotide [Vercoutere,W.A. et al. (2003) Nucleic Acids Res., 31, 1311-1318]. Here we investigate the mechanism(s) that may account for the ionic current gating signatures. The ionic current resistance profile of conductance states produced by DNA hairpin molecules with 3-12 bp stems showed a plateau in resistance between 10 and 12 bp, suggesting that hairpins with 10-12 bp stems span the pore vestibule. DNA hairpins with 9-12 bp stems produced gating signatures with the same relative conductance states. Systematic comparison of the conductance state dwell times and apparent activation energies for a series of 9-10 bp DNA hairpins suggest that the 3' and 5' ends interact at or near the limiting aperture within the vestibule of the alpha-hemolysin pore. The model presented may be useful in predicting and interpreting DNA detection using nanopore detectors. In addition, this well-defined molecular system may prove useful for investigating models of ligand-gated channels in biological membranes. C1 NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA USA. MAP Pharmaceut, Palo Alto, CA USA. US Genom, Woburn, MA USA. Univ Calif Santa Cruz, Ctr Biomol Sci & Engn, Santa Cruz, CA 95064 USA. RP Vercoutere, WA (reprint author), NASA, Ames Res Ctr, Div Life Sci, Mail Stop 236-7, Moffett Field, CA USA. EM wvercoutere@mail.arc.nasa.gov FU NHGRI NIH HHS [R01 HG003703] NR 59 TC 32 Z9 32 U1 0 U2 10 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD DEC PY 2006 VL 34 IS 22 BP 6425 EP 6437 DI 10.1093/nar/gkl754 PG 13 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 121XY UT WOS:000243191500010 PM 17130164 ER PT J AU De Pasquale, M Oates, S Beardmore, A Page, K Blustin, A Zane, S Page, M O'Mason, K Burrows, D Palmer, D Gehrels, N Nousek, J Roming, P Price, P Zhang, B Barthelmy, S Boyd, P Fink, R Kobayashi, S McNought, R Peterson, B Rich, J Rosen, S Sakamoto, T Schmidt, B Tueller, J Wells, A Ziaeepour, H McGowan, K Poole, T Falcone, A Blustin, AJ AF De Pasquale, M. Oates, S. Beardmore, A. Page, K. Blustin, A. Zane, S. Page, M. O'Mason, K. Burrows, D. Palmer, D. Gehrels, N. Nousek, J. Roming, P. Price, P. Zhang, B. Barthelmy, S. Boyd, P. Fink, R. Kobayashi, S. McNought, R. Peterson, B. Rich, J. Rosen, S. Sakamoto, T. Schmidt, B. Tueller, J. Wells, A. Ziaeepour, H. McGowan, K. Poole, T. Falcone, A. Blustin, A. J. TI Energy injection in GRB afterglows: The case of Swift GRBs 050401, 050801 and 050802 SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-BASIC TOPICS IN PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY AB Swift unprecedented fast follow-up observations of gamma-ray bursts have allowed us to discover a new feature of GRB afterglows: a phase of shallow decay, usually attributed to energy injection in the burst ejecta, which can last for several thousands of seconds both in the X-ray and optical bands. Here I discuss this phase in the case of Swift GRBs 050401, 050801 and 050802. C1 UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Univ Leicester, Leicester, Leics, England. Penn State Univ, Davey Lab, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Nevada, Las Vegas, NV 89154 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. RP De Pasquale, M (reprint author), UCL, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England. RI Barthelmy, Scott/D-2943-2012; Boyd, Patricia/D-3274-2012; Gehrels, Neil/D-2971-2012; Tueller, Jack/D-5334-2012; OI Schmidt, Brian/0000-0001-6589-1287 NR 3 TC 0 Z9 0 U1 0 U2 1 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 2037-4895 J9 NUOVO CIM B JI Nouvo Cimento Soc. Ital. Fis. B-Basic Top. Phys. PD DEC PY 2006 VL 121 IS 12 BP 1471 EP 1473 DI 10.1393/neb/i2007-10292-y PG 3 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900018 ER PT J AU Poole, TS De Pasquale, M Grupe, D Breeveld, AA Zane, S Rosen, SR Page, MJ Mason, KO Burrows, DN Krimm, HA Gehrels, N Nousek, JA Roming, PWA Kobayashi, S Zhang, B AF Poole, T. S. De Pasquale, M. Grupe, D. Breeveld, A. A. Zane, S. Rosen, S. R. Page, M. J. Mason, K. O. Burrows, D. N. Krimm, H. A. Gehrels, N. Nousek, J. A. Roming, P. W. A. Kobayashi, S. Zhang, B. TI Swift observations of GRB050712 SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-BASIC TOPICS IN PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY AB Swift observations of GRB050712 show that the X-ray light curve of this burst exhibits flaring activity in the first 500 s. We find that the initial flares can be due to "inner engine" activity, where the later flare may be explained in terms of the interaction of the ejecta with the surrounding medium. An optical counterpart was detected in the U and V band of UVOT up to 15000 s after the trigger. C1 UCL Homburg St Mary, MSSL, Dorking RH6 6NT, Surrey, England. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. Liverpool John Moores Univ, Astrophys Res Ist, Birkenhead CH4 1LD, Merseyside, England. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. RP Poole, TS (reprint author), UCL Homburg St Mary, MSSL, Dorking RH6 6NT, Surrey, England. RI Gehrels, Neil/D-2971-2012 NR 4 TC 0 Z9 0 U1 0 U2 1 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 2037-4895 J9 NUOVO CIM B JI Nouvo Cimento Soc. Ital. Fis. B-Basic Top. Phys. PD DEC PY 2006 VL 121 IS 12 BP 1567 EP 1568 DI 10.1393/ncb/i2007-10321-y PG 2 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900055 ER PT J AU Tashiro, MS Murakami, T Yoshida, A Kawai, N Nousek, J Angelini, L Kaluzienski, JL Kelley, LR Kinugasa, K Nakazawa, K Reeves, NJ Ricker, G Suzuki, M Takahashi, T Tamagawa, T Torii, K Ueda, Y Urata, Y Yamaoka, K Yamauchi, M Yonetoku, D AF Tashiro, M. S. Murakami, T. Yoshida, A. Kawai, N. Nousek, J. Angelini, L. Kaluzienski, J. L. Kelley, L. R. Kinugasa, K. Nakazawa, K. Reeves, N. J. Ricker, G. Suzuki, M. Takahashi, T. Tamagawa, T. Torii, K. Ueda, Y. Urata, Y. Yamaoka, K. Yamauchi, M. Yonetoku, D. CA Suzaku Team TI Capability and strategy of the X-ray afterglow observation with Suzaku SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-BASIC TOPICS IN PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY AB The Japanese X-ray astronomical satellite Suzaku launched in July 2005 is equipped with two kinds of X-ray instruments for the wide-band spectroscopy. The X-ray CCD cameras (XIS) cover 0.3 to 12 keV with the energy resolution of 120eV at 6keV. The Hard X-ray Detector (HXD) consisting of well-type phoswitch counters covers 40-600keV. With these instruments, we organized a team for quick follow-up observations of gamma-ray bursts, aiming to observe the afterglow phase transition and to search for spectral features with the wide band X-ray instruments. C1 Saitama Univ, Sakura, Saitama 3388570, Japan. Kanazawa Univ, Kanazawa, Ishikawa 9201192, Japan. Aoyama Gakuin Univ, Kanagawa 2298558, Japan. Tokyo Inst Technol, Meguro Ku, Tokyo 1528558, Japan. Penn State Univ, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Gunma Astron Observ, Gunma 3770702, Japan. Inst Space & Astronaut Sci, JAXA, Sagamihara, Kanagawa 2298510, Japan. MIT, CSR, Cambridge, MA 02139 USA. Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Osaka Univ, Osaka 5600043, Japan. Kyoto Univ, Sakyo Ku, Kyoto 6068502, Japan. Miyazaki Univ, Miyazaki 8892192, Japan. RP Tashiro, MS (reprint author), Saitama Univ, Sakura, Saitama 3388570, Japan. RI Tashiro, Makoto/J-4562-2012; XRAY, SUZAKU/A-1808-2009 NR 16 TC 0 Z9 0 U1 0 U2 0 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 2037-4895 EI 1594-9982 J9 NUOVO CIM B JI Nouvo Cimento Soc. Ital. Fis. B-Basic Top. Phys. PD DEC PY 2006 VL 121 IS 12 BP 1597 EP 1598 DI 10.1393/neb/i2007-10323-9 PG 2 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900066 ER PT J AU Marshall, F Mineo, T Troja, E AF Marshall, F. Mineo, T. Troja, E. TI Swift observations of GRB 051109A(*) SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY AB We report Swift observations of GRB 051109A, a bright, long burst detected with the Burst Alert Telescope (BAT). A bright afterglow was quickly detected with the X-Ray Telescope (XRT) and UltraViolet and Optical Telescope (UVOT), and observations continued for more than 10 days. The X-ray light curve is complex with a rapid initial decay followed by a more gradual decay. UVOT observations with the V, B, and U filters are consistent with a power law decay for the first 30 ks. The observations are used to constrain the jet opening angle and estimate the electron spectral index. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ist Astrofis Spaziale & Fis Cosm Palermo, INAF, Palermo, Italy. RP Marshall, F (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. OI Mineo, Teresa/0000-0002-4931-8445 NR 5 TC 0 Z9 0 U1 0 U2 0 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1594-9982 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD DEC PY 2006 VL 121 IS 12 BP 1517 EP 1518 DI 10.1393/ncb/i2007-10329-3 PG 2 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900037 ER PT J AU Nakagawa, Y Tashiro, M Abe, K Yoshida, A Yamaoka, K Nakazawa, K Murakami, T Yonetoku, D Kawai, N Nousek, J Ishikawa, N Urata, Y Onda, K Tamagawa, T Suzuki, M Kuwahara, M Takahashi, T Yamauchi, M Sonoda, E Maeno, S Kinugasa, K Kohmura, T Torii, K Ueda, Y Kubota, K Sugiyasu, K Kodaira, H Okuno, S Yoshinari, S Shimokawabe, T Ishimura, T Ricker, G Reeves, J Angelini, L Kaluzienski, L Kelley, R AF Nakagawa, Y. E. Tashiro, M. Abe, K. Yoshida, A. Yamaoka, K. Nakazawa, K. Murakami, T. Yonetoku, D. Kawai, N. Nousek, J. Ishikawa, N. Urata, Y. Onda, K. Tamagawa, T. Suzuki, M. Kuwahara, M. Takahashi, T. Yamauchi, M. Sonoda, E. Maeno, S. Kinugasa, K. Kohmura, T. Torii, K. Ueda, Y. Kubota, K. Sugiyasu, K. Kodaira, H. Okuno, S. Yoshinari, S. Shimokawabe, T. Ishimura, T. Ricker, G. R. Reeves, J. N. Angelini, L. Kaluzienski, L. J. Kelley, R. L. TI Detailed analyses of GRB 060105 X-ray afterglow observed by Suzaku SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY ID BURST AB GRB 060105 was detected with the BAT instrument on-board Swift. The Suzaku follow-up observation started just 5.3 hours after the trigger with the XIS and HXD instruments. The XIS detected an uncatalogued fading source and its position was consistent with that previously reported by Swift XRT. We performed the spectral analyses using the data derived from Suzaku XIS and Swift XRT, and found that the spectrum of X-ray afterglow was well reproduced by the absorbed power law model. C1 Aoyama Gakuin Univ, Dept Math & Phys, Kanagawa, Japan. Saitama Univ, High Energy Astrophys Lab, Saitama, Japan. Inst Phys & Chem Res, Saitama, Japan. ISAS JAXA, Sagamihara, Kanagawa, Japan. Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan. Penn State Univ, University Pk, PA 16802 USA. Miyazaki Univ, Fac Engn, Miyazaki 88921, Japan. Gunma Astron Observ, Gunma, Japan. Kogakuin Univ, Tokyo, Japan. Osaka Univ, Osaka, Japan. Kyoto Univ, Kyoto, Japan. MIT, Ctr Space Res, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Kanazawa Univ, Kanazawa, Ishikawa 920, Japan. RP Nakagawa, Y (reprint author), Aoyama Gakuin Univ, Dept Math & Phys, Kanagawa, Japan. RI Tashiro, Makoto/J-4562-2012; Kelley, Richard/K-4474-2012; XRAY, SUZAKU/A-1808-2009 NR 9 TC 0 Z9 0 U1 0 U2 0 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1594-9982 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD DEC PY 2006 VL 121 IS 12 BP 1531 EP 1533 DI 10.1393/ncb/i2007-10316-8 PG 3 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900044 ER PT J AU Nakagawa, YE Yoshida, A Sugita, S Tanaka, K Ishikawa, N Tamagawa, T Suzuki, M Shirasaki, Y Kawai, N Matsuoka, M Atteia, JL Pelangeon, A Vanderspek, R Crew, GB Villasenor, JS Butler, N Doty, J Ricker, GR Pizzichini, G Donaghy, TQ Lamb, DQ Graziani, C Jernigan, JG Sakamoto, T Olive, JF Boer, M Fenimore, EE Galassi, M Woosley, SE Yamauchi, M Takagishi, K Hatsukade, I AF Nakagawa, Y. E. Yoshida, A. Sugita, S. Tanaka, K. Ishikawa, N. Tamagawa, T. Suzuki, M. Shirasaki, Y. Kawai, N. Matsuoka, M. Atteia, J.-L. Pelangeon, A. Vanderspek, R. Crew, G. B. Villasenor, J. S. Butler, N. Doty, J. Ricker, G. R. Pizzichini, G. Donaghy, T. Q. Lamb, D. Q. Graziani, C. Jernigan, J. G. Sakamoto, T. Olive, J.-F. Boer, M. Fenimore, E. E. Galassi, M. Woosley, S. E. Yamauchi, M. Takagishi, K. Hatsukade, I. TI Observation of GRB 051022 detected by HETE-2 SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY ID SPECTRA AB An "optically dark" burst GRB051022 was detected by HETE-2. The detections of candidate X-ray and radio afterglows were reported, whereas no optical afterglow was found in spite of quick follow-up observations. The optical spectroscopic observations of the host galaxy revealed the redshift z = 0.8. Using the data derived by HETE-2 observation of the prompt emission, we found the constant absorption N-H = 8.8(+3.1) x 10(22) cm(-2) and the visual extinction A(v) = 49(-16)(+17) mag in the host galaxy. C1 Aoyama Gakuin Univ, Dept Math & Phys, Kanagawa, Japan. Inst Phys & Chem Res, Saitama, Japan. Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan. Natl Astron Observ, Tokyo 181, Japan. JAXA, Tsukuba Space Ctr, Ibaraki, Japan. Observ Midi Pyrenees, LAT, F-31400 Toulouse, France. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. INAF IASF Bologna, Bologna, Italy. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Observ Midi Pyrenees, CESR, F-31400 Toulouse, France. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Miyazaki Univ, Fac Engn, Miyazaki 88921, Japan. RP Nakagawa, Y (reprint author), Aoyama Gakuin Univ, Dept Math & Phys, Kanagawa, Japan. NR 8 TC 0 Z9 0 U1 0 U2 0 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1594-9982 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD DEC PY 2006 VL 121 IS 12 BP 1535 EP 1537 DI 10.1393/ncb/i2007-10315-9 PG 3 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900045 ER PT J AU Nishikawa, KI Ramirez-Ruiz, E Hededal, CB Hardee, P Mizuno, Y Fishman, GJ AF Nishikawa, K.-I. Ramirez-Ruiz, E. Hededal, C. B. Hardee, P. Mizuno, Y. Fishman, G. J. TI Simulation study of jitter radiation associated with afterglows observed with Swift(*) SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY ID MAGNETIC-FIELD GENERATION; RAY BURST SOURCES; PARTICLE-ACCELERATION; RELATIVISTIC SHOCKS; WEIBEL INSTABILITY; PLASMA AB Using a 3D Relativistic Particle-In-Cell (RPIC) code, we have investigated particle acceleration associated with a relativistic electron-positron jet front propagating into an ambient electron-positron plasma without initial magnetic fields in order to investigate the nonlinear stage of the Weibel instability. The growth time and nonlinear saturation levels depend on the initial jet parallel velocity distributions. Simulations show that the Weibel instability created in the collision-less shocks accelerates jet and ambient particles both perpendicular and parallel to the jet propagation direction. The nonlinear fluctuation amplitude of densities, currents, electric, and magnetic fields in the electron-positron shocks are larger for smaller jet Lorentz factor. This comes from the fact that the growth time of the Weibel instability is proportional to the square of the jet Lorentz factor. We have performed simulations with broad Lorentz factor distribution of jet electrons and positrons, which are assumed to be created by the photon annihilation. Simulation results show that the Weibel instability is responsible for generating and amplifying nonuniform, magnetic fields perpendicular to the jet propagation direction and contribute to the electron's (positron's) transverse deflection behind the jet head. This small-scale magnetic-field structure is appropriate to the generation of "jitter" radiation from deflected electrons (positrons) as opposed to synchrotron radiation. The jitter radiation resulting from small-scale magnetic-field structures may be important for understanding the complex time structure and spectral evolution observed in gamma-ray bursts or other astrophysical sources containing relativistic jets and relativistic collisionless shocks. C1 NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. Inst Adv Study, Princeton, NJ 08540 USA. Niels Bohr Inst, Dark Cosmol Ctr, DK-2100 Copenhagen, Denmark. Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. RP Nishikawa, KI (reprint author), NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. OI Mizuno, Yosuke/0000-0002-8131-6730 NR 12 TC 0 Z9 0 U1 0 U2 0 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1594-9982 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD DEC PY 2006 VL 121 IS 12 BP 1543 EP 1546 DI 10.1393/ncb/i2007-10307-9 PG 4 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900048 ER PT J AU Perri, M Guetta, D Antonelli, LA Cucchiara, A Mangano, V Reeves, J Burrows, DN Campana, S Capalbi, M Chincarini, G Cusumano, G Giommi, P La Parola, V Mineo, T Moretti, A Romano, P Tagliaferri, G Troja, E Vetere, L AF Perri, M. Guetta, D. Antonelli, L. A. Cucchiara, A. Mangano, V. Reeves, J. Burrows, D. N. Campana, S. Capalbi, M. Chincarini, G. Cusumano, G. Giommi, P. La Parola, V. Mineo, T. Moretti, A. Romano, P. Tagliaferri, G. Troja, E. Vetere, L. TI The flaring afterglow of GRB 050730 SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY AB We present a detailed spectral and temporal analysis of Swift and XMM-Newton observations of GRB 050730. The X-ray afterglow of GRB 050730 was found to decline with time with intense flaring activity superimposed. Evidence of flaring activity in the early UVOT optical afterglow, simultaneous with that observed in the X-ray band, was found. Strong spectral evolution in the X-ray energy band during the flaring activity was present. C1 ASI Sci Data Ctr, Frascati, Italy. Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Ist Astrofis Spaziale & Fis Cosm, INAF, Palermo, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Osserv Astron Brera, INAF, Merate, LC, Italy. Univ Milano Bicocca, Dipartimento Fis, Milan, Italy. RP Perri, M (reprint author), ASI Sci Data Ctr, Frascati, Italy. OI Mineo, Teresa/0000-0002-4931-8445; guetta, dafne/0000-0002-7349-1109; giommi, paolo/0000-0002-2265-5003; Cusumano, Giancarlo/0000-0002-8151-1990; Perri, Matteo/0000-0003-3613-4409; La Parola, Valentina/0000-0002-8087-6488; Tagliaferri, Gianpiero/0000-0003-0121-0723 NR 3 TC 0 Z9 0 U1 0 U2 0 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1594-9982 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD DEC PY 2006 VL 121 IS 12 BP 1557 EP 1559 DI 10.1393/ncb/i2007-10308-8 PG 3 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900052 ER PT J AU Piron, F McEnery, JE AF Piron, F. McEnery, J. E. CA GRB LAT Science Team TI GRB observations with GLAST and TeV experiments SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY ID GAMMA-RAY BURST; HIGH-ENERGY AB The Gamma-Ray Large Area Space Telescope (GLAST) is scheduled to be launched in 2008, with the capability of observing GRBs from 10 keV to more than 300 GeV. Since the spectral and temporal properties of GRBs above a few GeV are still almost unknown, extending these detections to higher energies would have a large impact on the knowledge of the particle acceleration and emission processes occuring within these sources. It would also allow their use as probes of the distant Universe and to study its transparency to high-energy gamma-rays. Here we review the requirements for a good coordination of GLAST with ground-based telescopes operating above a few tens of GeV, and examine the potential of such simultaneous observations in terms of expected rates of alerts and sensitivity. C1 CNRS, IN2P3, LPTA, F-34095 Montpellier, France. Univ Montpellier 2, F-34095 Montpellier, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Piron, F (reprint author), CNRS, IN2P3, LPTA, F-34095 Montpellier, France. RI McEnery, Julie/D-6612-2012 NR 4 TC 0 Z9 0 U1 0 U2 0 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1594-9982 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD DEC PY 2006 VL 121 IS 12 BP 1563 EP 1565 DI 10.1393/ncb/i2007-10341-7 PG 3 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900054 ER PT J AU Suzuki, M Arimoto, M Ishikawa, N Kobayashi, A Kotoku, J Maetou, M Nakagawa, Y Sakamoto, T Sato, R Shimokawabe, T Shirasaki, Y Sugita, S Tamagawa, T Tanaka, K Kawai, N Yoshida, A Matsuoka, M Butler, N Crew, GB Vanderspek, R Graziani, C Donaghy, TQ Doty, J Fenimore, EE Galassi, M AF Suzuki, M. Arimoto, M. Ishikawa, N. Kobayashi, A. Kotoku, J. Maetou, M. Nakagawa, Y. Sakamoto, T. Sato, R. Shimokawabe, T. Shirasaki, Y. Sugita, S. Tamagawa, T. Tanaka, K. Kawai, N. Yoshida, A. Matsuoka, M. Butler, N. Crew, G. B. Vanderspek, R. Graziani, C. Donaghy, T. Q. Doty, J. Fenimore, E. E. Galassi, M. CA Hete Science Team TI X-ray bursts observed by HETE-2 SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY AB The High Energy Transient Explorer II (HETE-2) observed more than 500 X-Ray Bursts (XRBs) since its launch. Most of them are from similar to 20 known X-ray sources. We investigated the observation coverage for each source and studied the frequency of the bursts from each source from 2001 to 2005. C1 Tokyo Inst Technol, Dept Phys, Tokyo, Japan. MIT, Kavli Inst, Cambridge, MA 02139 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Noqsi Aerosp Ltd, Pine, CO USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Aoyama Gakuin Univ, Dept Math & Phys, Tokyo 150, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 TC 2 Z9 2 U1 0 U2 1 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1594-9982 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD DEC PY 2006 VL 121 IS 12 BP 1593 EP 1594 DI 10.1393/neb/i2007-10306-x PG 2 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900064 ER PT J AU Van der Horst, AJ Kamble, A Wijer, RAMJ Resmi, L Bhattacharya, D Rol, E Strom, R Kouveliotou, C Oosterloo, T Ishwara-Chandra, CH AF Van der Horst, A. J. Kamble, A. Wijer, R. A. M. J. Resmi, L. Bhattacharya, D. Rol, E. Strom, R. Kouveliotou, C. Oosterloo, T. Ishwara-Chandra, C. H. TI GRB 030329: Three years of radio afterglow monitoring SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article; Proceedings Paper CT Workshop on Swift and GRBs - Unveiling the Relativistic University CY JUN 05-09, 2006 CL Venice, ITALY ID CALORIMETRY; JET AB Radio observations of Gamma-Ray Burst (GRB) afterglows are essential for our understanding of the physics of relativistic blast waves, as they enable us to follow the evolution of GRB explosions much longer than the afterglows in any other wave band. We have performed a three-year monitoring campaign of GRB030329 with the Westerbork Synthesis Radio Telescopes (WSRT) and the Giant Metrewave Radio Telescope (GMRT). Our observations, combined with observations at other wavelengths, have allowed its to determine the GR13 blast wave physical parameters, such as the total burst energy and the ambient medium density, as well as investigate the jet nature of the relativistic outflow. Further, by modeling the late-time radio light curve of GRB 030329, we predict that the Low Frequency Array (LOFAR, 30-240 MHz) will be able to observe afterglows of similar GRBs, and constrain the physics of the blast wave during its non-relativistic phase. C1 Univ Amsterdam, Astron Inst, NL-1098 SJ Amsterdam, Netherlands. Raman Res Inst, Bangalore 560080, Karnataka, India. Indian Inst Sci, Joint Astron Programme, Bangalore 560012, Karnataka, India. Univ Leicester, Dept Phys & Astron, Leicester LE2 7RH, Leics, England. ASTRON, NL-7990 AA Dwingeloo, Netherlands. NASA, MSFC, NSSTC, Huntsville, AL 35805 USA. Natl Ctr Radio Astrophys, Pune 411007, Maharashtra, India. RP Van der Horst, AJ (reprint author), Univ Amsterdam, Astron Inst, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. RI Bhattacharya, Dipankar/J-6927-2015; OI Bhattacharya, Dipankar/0000-0003-3352-3142; Wijers, Ralph/0000-0002-3101-1808 NR 5 TC 1 Z9 1 U1 0 U2 0 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1594-9982 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD DEC PY 2006 VL 121 IS 12 BP 1605 EP 1606 DI 10.1393/ncb/i2007-10327-5 PG 2 WC Physics, Multidisciplinary SC Physics GA 225VS UT WOS:000250546900069 ER PT J AU Barnier, B Du Penhoat, Y Fu, LL Morrow, R Verron, J Woodworth, P AF Barnier, Bernard Du Penhoat, Yves Fu, Lee-Lueng Morrow, Rosemary Verron, Jacques Woodworth, Phil TI Untitled SO OCEAN DYNAMICS LA English DT Editorial Material C1 LEGI, Grenoble, France. LEGOS, Toulouse, France. JPL, Pasadena, CA USA. POL, Liverpool, Merseyside, England. RP Barnier, B (reprint author), LEGI, Grenoble, France. EM Bernard.Barnier@hmg.inpg.fr RI Barnier, Bernard/F-2400-2016 OI Barnier, Bernard/0000-0002-7539-2542 NR 0 TC 6 Z9 6 U1 0 U2 1 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 1616-7341 J9 OCEAN DYNAM JI Ocean Dyn. PD DEC PY 2006 VL 56 IS 5-6 BP 377 EP 378 DI 10.1007/s10236-006-0090-1 PG 2 WC Oceanography SC Oceanography GA 121XI UT WOS:000243189900001 ER PT J AU Andersen, OB Egbert, GD Erofeeva, SY Ray, RD AF Andersen, Ole B. Egbert, Gary D. Erofeeva, Svetlana Y. Ray, Richard D. TI Mapping nonlinear shallow-water tides: a look at the past and future SO OCEAN DYNAMICS LA English DT Article DE tides; nonlinear tides; overtides; satellite altimetry ID EUROPEAN CONTINENTAL-SHELF; 3-DIMENSIONAL MODEL; ENGLISH-CHANNEL; SPECTRAL DECOMPOSITION; TIDAL SPECTROSCOPY; SEMIDIURNAL TIDE; LITTORAL TIDES; QUADRATIC TERM; OCEAN TIDES; NORTH AB Overtides and compound tides are generated by nonlinear mechanisms operative primarily in shallow waters. Their presence complicates tidal analysis owing to the multitude of new constituents and their possible frequency overlap with astronomical tides. The science of nonlinear tides was greatly advanced by the pioneering researches of Christian Le Provost who employed analytical theory, physical modeling, and numerical modeling in many extensive studies, especially of the tides of the English Channel. Le Provost's complementary work with satellite altimetry motivates our attempts to merge these two interests. After a brief review, we describe initial steps toward the assimilation of altimetry into models of nonlinear tides via generalized inverse methods. A series of barotropic inverse solutions is computed for the M(4) tide over the northwest European Shelf. Future applications of altimetry to regions with fewer in situ measurements will require improved understanding of error covariance models because these control the tradeoffs between fitting hydrodynamics and data, a delicate issue in coastal regions. While M(4) can now be robustly determined along the Topex/Poseidon satellite ground tracks, many other compound tides face serious aliasing problems. C1 Danish Natl Space Ctr, DK-2100 Copenhagen, Denmark. Oregon State Univ, COAS, Corvallis, OR 97331 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Andersen, OB (reprint author), Danish Natl Space Ctr, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark. EM oa@spacecenter.dk; egbert@coas.oregonstate.edu; serofeev@coas.oregonstate.edu; richard.ray@nasa.gov RI Ray, Richard/D-1034-2012; Andersen, Ole /H-7481-2016; OI Andersen, Ole /0000-0002-6685-3415; Egbert, Gary/0000-0003-1276-8538 NR 48 TC 17 Z9 17 U1 2 U2 6 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 1616-7341 J9 OCEAN DYNAM JI Ocean Dyn. PD DEC PY 2006 VL 56 IS 5-6 BP 416 EP 429 DI 10.1007/s10236-006-0060-7 PG 14 WC Oceanography SC Oceanography GA 121XI UT WOS:000243189900004 ER PT J AU Lombard, A Cazenave, A Le Traon, PY Guinehut, S Cabanes, C AF Lombard, Alix Cazenave, Anny Le Traon, Pierre-Yves Guinehut, Stephanie Cabanes, Cecile TI Perspectives on present-day sea level change: a tribute to Christian le Provost SO OCEAN DYNAMICS LA English DT Article DE sea level; thermal expansion; climate change; ocean warming ID RISE; OCEAN; TEMPERATURE; EXPANSION; MASS AB In this paper, we first discuss the controversial result of the work by Cabanes et al. (Science 294:840-842, 2001), who suggested that the rate of past century sea level rise may have been overestimated, considering the limited and heterogeneous location of historical tide gauges and the high regional variability of thermal expansion which was supposed to dominate the observed sea level. If correct, this conclusion would have solved the problem raised by the IPCC third assessment report [Church et al, Cambridge University Press, Cambridge, pp 881, 2001], namely, the factor two difference between the 20th century observed sea level rise and the computed climatic contributions. However, recent investigations based on new ocean temperature data sets indicate that thermal expansion only explains part (about 0.4 mm/year) of the 1.8 mm/year observed sea level rise of the past few decades. In fact, the Cabanes et al.'s conclusion was incorrect due to a contamination of abnormally high ocean temperature data in the Gulf Stream area that led to an overestimate of thermal expansion in this region. In this paper, we also estimate thermal expansion over the last decade (1993-2003), using a new ocean temperature and salinity database. We compare our result with three other estimates, two being based on global gridded data sets, and one based on an approach similar to that developed here. It is found that the mean rate of thermosteric sea level rise over the past decade is 1.5 +/- 0.3 mm/year, i.e. 50% of the observed 3 mm/year by satellite altimetry. For both time spans, past few decades and last decade, a contribution of 1.4 mm/year is not explained by thermal expansion, thus needs to be of water mass origin. Direct estimates of land ice melt for the recent years account for about 1 mm/year sea level rise. Thus, at least for the last decade, we have moved closer to explaining the observed rate of sea level rise than the IPCC third assessment report. C1 CNES, LEGOS, F-31401 Toulouse 9, France. IFREMER, Plouzane, France. JPL, Pasadena, CA USA. RP Lombard, A (reprint author), CNES, LEGOS, 18 Ave E Belin, F-31401 Toulouse 9, France. EM lombard@notos.cst.cnes.fr NR 30 TC 16 Z9 16 U1 0 U2 2 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 1616-7341 EI 1616-7228 J9 OCEAN DYNAM JI Ocean Dyn. PD DEC PY 2006 VL 56 IS 5-6 BP 445 EP 451 DI 10.1007/s10236-005-0046-x PG 7 WC Oceanography SC Oceanography GA 121XI UT WOS:000243189900006 ER PT J AU Nerger, L Danilov, S Hiller, W Schroter, J AF Nerger, Lars Danilov, Sergey Hiller, Wolfgang Schroeter, Jens TI Using sea-level data to constrain a finite-element primitive-equation ocean model with a local SEIK filter SO OCEAN DYNAMICS LA English DT Article DE data assimilation; finite elements; SEIK filter; local filter ID ENSEMBLE KALMAN FILTER; ATMOSPHERIC DATA ASSIMILATION; SEQUENTIAL DATA ASSIMILATION; OCEANOGRAPHY; TEMPERATURE; ATLANTIC; SYSTEMS AB Inspired by the pioneering work of Christian Le Provost on finite element ocean modeling, a new ocean circulation model was developed over the last few years. It applies a surface triangulation and finite elements for an accurate description of coasts and bathymetry and their steering effect on the ocean circulation. A novel feature is the mesh design, which allows a vertical structure in geopotential (z) coordinates without loss of flexibility and avoids pressure gradient errors everywhere except for the lowest layer of abyssal ocean. The model is combined with sea-level measurements and data assimilation, another major research topic of Christian Le Provost. We apply the SEIK filter that was developed in Grenoble while Christian was teaching there. The addition of a local analysis scheme improves the filter performance, first of all, in its variance estimates and also in its mean solution. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Alfred Wegener Inst Polar & Marine Res, D-27515 Bremerhaven, Germany. RP Nerger, L (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM lnerger@gmao.gsfc.nasa.gov RI Nerger, Lars/G-4845-2013; Danilov, Sergey/S-6184-2016 OI Nerger, Lars/0000-0002-1908-1010; NR 26 TC 26 Z9 26 U1 1 U2 1 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 1616-7341 J9 OCEAN DYNAM JI Ocean Dyn. PD DEC PY 2006 VL 56 IS 5-6 BP 634 EP 649 DI 10.1007/s10236-006-0083-0 PG 16 WC Oceanography SC Oceanography GA 121XI UT WOS:000243189900020 ER PT J AU Fedele, F AF Fedele, Francesco TI On wave groups in a Gaussian sea SO OCEAN ENGINEERING LA English DT Article DE successive wave crests; Gaussian sea; quasi-determinism; wave group; conditional probability; extreme event; nonlinear evolution ID EXPECTED STRUCTURE; EXTREME WAVES; RANDOM-FIELDS; WIND-WAVES; HEIGHTS; MAXIMA AB In the context of Gaussian waves, if two successive wave crests of amplitude h(1) and h(2), respectively, are recorded in time at a fixed point x(0) then in the limit of h(1) -> infinity and h(2) -> 00, with probability approaching 1, a wave group has passed closed by the point x(0) at the apex of its development stage, giving rise to an isolated extreme crest. The two large successive wave crests occur at x(0) during the initial phase of decay of the wave group and they are lagged in time by T-2* + O(h(1)(-1),h(2)(-1)), T-2* being the abscissa of the second absolute maximum of the time covariance function psi(T) of the surface displacement. Thus, either an isolated extreme crest event or two consecutive extreme crest events are particular realizations of the space-time evolution of a wave group, in agreement with the theory of quasi determinism of Boccotti [2000. Wave Mechanics for Ocean Engineering. Elsevier, Oxford]. This result is of relevant interest for offshore engineering. Firstly, the design of offshore structures resisting to a double wave impact can be based on the wave forces generated by the mechanics of a single wave group. On the other hand, in the context of nonlinear water waves, extreme events and their probability of occurrence can be investigated by studying the nonlinear evolution of a wave group. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Global Atmospher Modeling Off, Greenbelt, MD 20771 USA. RP Fedele, F (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci Technol Ctr, Baltimore, MD 21228 USA. EM fedele@gmao.gsfc.nasa.gov RI Fedele, Francesco/J-7651-2012 OI Fedele, Francesco/0000-0001-6403-4224 NR 28 TC 6 Z9 7 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0029-8018 J9 OCEAN ENG JI Ocean Eng. PD DEC PY 2006 VL 33 IS 17-18 BP 2225 EP 2239 DI 10.1016/j.oceaneng.2006.01.001 PG 15 WC Engineering, Marine; Engineering, Civil; Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 107UV UT WOS:000242197400001 ER PT J AU Wynne, RH Nelson, RF AF Wynne, Randolph H. Nelson, Ross F. TI SilviScan special issue - Lidar applications in forest assessment and inventory - Foreword SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Editorial Material C1 Virginia Polytech Inst & State Univ, Ctr Environm Applicat Remote Sensing, Coll Nat Resources, Blacksburg, VA 24061 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wynne, RH (reprint author), Virginia Polytech Inst & State Univ, Ctr Environm Applicat Remote Sensing, Coll Nat Resources, Blacksburg, VA 24061 USA. RI Nelson, Ross/H-8266-2014 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD DEC PY 2006 VL 72 IS 12 BP 1337 EP 1338 PG 2 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 113YR UT WOS:000242634400003 ER PT J AU Nayegandhi, A Brock, JC Wright, CW O'Connell, MJ AF Nayegandhi, Amar Brock, John C. Wright, C. Wayne O'Connell, Michael J. TI Evaluating a small footprint, waveform-resolving lidar over coastal vegetation communities SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article; Proceedings Paper CT Silviscan 2005 Conference on Lidar Applications in Forest Assessment and Inventory CY SEP 29-OCT 01, 2005 CL Blacksburg, VA ID LASER ALTIMETER; CANOPY STRUCTURE; FOREST; DENSITY; BIOMASS; VOLUME AB NASA's Experimental Advanced Airborne Research Lidar (EAARL) is a raster-scanning, waveform-resolving, green-wavelength (532 nm) lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor records the time history of the return waveform within a small footprint (20 cm diameter) for each laser pulse, enabling characterization of vegetation canopy structure and "bare earth" topography under a variety of vegetation types. A collection of individual waveforms combined within a synthesized large footprint was used to define three metrics: canopy height (CH), canopy reflection ratio (CRR), and height of median energy (HOME). Bare Earth Elevation (BEE) metric was derived using the individual small-footprint waveforms, All four metrics were tested for reproducibility, which resulted in an average of 95 percent correspondence within two standard deviations of the mean. CH and BEE values were also tested for accuracy using ground-truth data. The results presented in this paper show that combining several individual small-footprint laser pulses to define a composite "large-footprint" waveform is a possible method to depict the vertical structure of a vegetation canopy. C1 US Geol Survey, ETI Profess Inc, Florida Integrated Sci Ctr, St Petersburg, FL 33701 USA. NASA, Goddard Space Flight Ctr, Instrumentat Sci Branch, Wallops Isl, VA 23337 USA. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22904 USA. RP Nayegandhi, A (reprint author), US Geol Survey, ETI Profess Inc, Florida Integrated Sci Ctr, St Petersburg, FL 33701 USA. EM anayegandhi@usgs.gov NR 32 TC 27 Z9 27 U1 0 U2 6 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD DEC PY 2006 VL 72 IS 12 BP 1407 EP 1417 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 113YR UT WOS:000242634400011 ER PT J AU Birnbaum, KM Parkins, AS Kimble, HJ AF Birnbaum, K. M. Parkins, A. S. Kimble, H. J. TI Cavity QED with multiple hyperfine levels SO PHYSICAL REVIEW A LA English DT Article ID SINGLE QUANTUM-DOT; ATOMS AB We calculate the weak-driving transmission of a linearly polarized cavity mode strongly coupled to the D2 transition of a single cesium atom. Results are relevant to future experiments with microtoroid cavities, where the single-photon Rabi frequency g exceeds the excited-state hyperfine splittings, and photonic band-gap resonators, where g is greater than both the excited- and ground-state splitting. C1 CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Auckland, Dept Phys, Auckland, New Zealand. RP Birnbaum, KM (reprint author), CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. NR 14 TC 8 Z9 8 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2006 VL 74 IS 6 AR 063802 DI 10.1103/PhysRevA.74.063802 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 121OK UT WOS:000243166700142 ER PT J AU Florescu, L AF Florescu, Lucia TI Spectrum of a one-atom laser in photonic crystals SO PHYSICAL REVIEW A LA English DT Article ID BAND-GAP; SPONTANEOUS EMISSION; QUANTUM ELECTRODYNAMICS; CAVITY; EDGE AB The emission spectrum of a single-emitter laser in a photonic crystal is presented. We consider a coherently pumped two-level emitter strongly coupled to a high-quality microcavity engineered within a photonic crystal. We show that the cavity spectrum consists of both elastic and inelastic components, for which we derive analytical expressions. Our study reveals enhanced, spectrally narrower emission resulting from the radiation reservoir of the photonic crystal. The cavity field spectral characteristics are fundamentally distinct from those of a corresponding microcavity in ordinary vacuum. At high pump intensities and for large discontinuities in the photon density of states between Mollow spectral components of atomic resonance fluorescence, the emitted intensity originating from the elastic spectral component increases with the intensity of the pump and the elastic component dominates the spectrum. In the case of a vanishing photon density of states in the spectral range surrounding the lower Mollow sideband and no dipolar dephasing, the cavity spectrum is elastic. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Florescu, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 126-347, Pasadena, CA 91109 USA. NR 28 TC 15 Z9 15 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2006 VL 74 IS 6 AR 063828 DI 10.1103/PhysRevA.74.063828 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 121OK UT WOS:000243166700168 ER PT J AU Grudinin, IS Ilchenko, VS Maleki, L AF Grudinin, Ivan S. Ilchenko, Vladimir S. Maleki, Lute TI Ultrahigh optical Q factors of crystalline resonators in the linear regime SO PHYSICAL REVIEW A LA English DT Article ID MICROSPHERES; TRANSMISSION; ULTRAVIOLET; SCATTERING AB Experimental demonstration of record optical quality factor of (6.3 +/- 0.8)x10(10) corresponding to cavity ring-down time of tau similar or equal to 36 mu s is made possible by avoiding nonlinear effects in a crystalline whispering gallery mode resonator. We discuss various loss mechanisms in CaF2 cavities and ways of achieving higher quality factors. Possible applications in quantum optics and photonics are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Grudinin, IS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM grudinin@caltech.edu NR 29 TC 82 Z9 83 U1 4 U2 18 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2006 VL 74 IS 6 AR 063806 DI 10.1103/PhysRevA.74.063806 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 121OK UT WOS:000243166700146 ER PT J AU Durgun, E Senger, RT Sevincli, H Mehrez, H Ciraci, S AF Durgun, E. Senger, R. T. Sevincli, H. Mehrez, H. Ciraci, S. TI Spintronic properties of carbon-based one-dimensional molecular structures SO PHYSICAL REVIEW B LA English DT Article ID TOTAL-ENERGY CALCULATIONS; INTERLAYER EXCHANGE; MAGNETIC-PROPERTIES; ATOMIC WIRES; ELECTRON-GAS; MAGNETORESISTANCE; RESISTANCE; SUPERLATTICES; OSCILLATIONS; CONDUCTANCE AB In this paper we present an extensive study of the electronic, magnetic, and transport properties of finite and infinite periodic atomic chains composed of carbon atoms and 3d transition metal (TM) atoms using first-principles methods. Finite-size, linear molecules made of carbon atomic chains caped with TM atoms, i.e., TM-C-n-TM structures are stable and exhibit interesting magnetoresistive properties. The indirect exchange interaction of the two TM atoms through a spacer of n carbon atoms determines the type of the magnetic ground state of these structures. The n-dependent (n=1 to 7) variations of the ground state between ferromagnetic and antiferromagnetic spin configurations exhibit several distinct forms, including regular alternations for Ti, V, Mn, Cr, Fe, and Co, and irregular forms for Sc and Ni cases. We present a simple analytical model that can successfully simulate these variations, and the induced magnetic moments on the carbon atoms. Depending on the relative strengths of the carbon s, p and TM d orbital spin-dependent coupling and on the on-site energies of the TM atoms there induces long-range spin polarizations on the carbon atoms which mediate the exchange interaction. While periodically repeated TM-C-n atomic chains exhibit half-metallic properties with perfect spin polarization at the Fermi level, finite but asymmetric chains comprising single, double, and triple TM atoms display interesting spin-dependent features. These properties may be altered when these structures are coupled to electrodes. However, when connected to appropriate electrodes the TM-C-n-TM atomic chains act as molecular spin valves in their ferromagnetic states due to the large ratios of the conductance values for each spin type. C1 Bilkent Univ, Dept Phys, TR-06800 Ankara, Turkey. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Adv Supercomp Div, Moffett Field, CA 94035 USA. RP Durgun, E (reprint author), Bilkent Univ, Dept Phys, TR-06800 Ankara, Turkey. EM ciraci@fen.bilkent.edu.tr RI Senger, Tugrul/B-8207-2009; Sevincli, Haldun/E-5771-2010 OI Senger, Tugrul/0000-0003-0800-1924; Sevincli, Haldun/0000-0002-1896-2588 NR 72 TC 14 Z9 15 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC PY 2006 VL 74 IS 23 AR 235413 DI 10.1103/PhysRevB.74.235413 PG 13 WC Physics, Condensed Matter SC Physics GA 121ZO UT WOS:000243195700101 ER PT J AU Lee, S von Allmen, P AF Lee, Seungwon von Allmen, Paul TI Magnetic-field dependence of valley splitting in Si quantum wells grown on tilted SiGe substrates SO PHYSICAL REVIEW B LA English DT Article ID EFFECTIVE MASS; INVERSION LAYER; SPIN AB The valley splitting of the first few Landau levels is calculated as a function of the magnetic field for electrons confined in a strained silicon quantum well grown on a tilted SiGe substrate, using a parametrized tight-binding method. More specifically, the valley splitting arising from the effect of misorientation between the crystal axis and the confinement direction of the quantum well is investigated. In the absence of misorientation (zero substrate tilt angle), the valley splitting slightly decreases with increasing magnetic field. In contrast, the valley splitting for a finite substrate tilt angle exhibits a strong and nonmonotonic dependence on the magnetic-field strength. The valley splitting of the first Landau level shows an exponential increase followed by a slow saturation as the magnetic-field strength increases. The valley splitting of the second and third Landau levels shows an oscillatory behavior. The nonmonotonic dependence is explained by the phase variation of the Landau-level wave function along the washboardlike interface between the tilted quantum well and the buffer material. The phase variation is a direct consequence of the misorientation. This result suggests that when the misorientation effect is dominant, the magnitude of the valley splitting can be easily tuned by controlling the Landau-level filling factor through the magnetic field and the doping concentration. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lee, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 23 TC 9 Z9 9 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD DEC PY 2006 VL 74 IS 24 AR 245302 DI 10.1103/PhysRevB.74.245302 PG 5 WC Physics, Condensed Matter SC Physics GA 121ZP UT WOS:000243195800064 ER PT J AU Savchenkov, AA Matsko, AB Strekalov, D Ilchenko, VS Maleki, L AF Savchenkov, Anatoliy A. Matsko, Andrey B. Strekalov, Dmitry Ilchenko, Vladimir S. Maleki, Lute TI Enhancement of photorefraction in whispering gallery mode resonators SO PHYSICAL REVIEW B LA English DT Article ID LINBO3; STORAGE; POLARONS AB We report on the study of photorefractive properties of as-grown nominally pure lithium niobate and tantalate crystals using whispering gallery mode (WGM) resonators. The photorefractive effect manifests itself as a dynamic modification of the spectrum of the resonator, which includes the relative motion of various families of WGMs in the frequency space. We have observed the effect in near (780 nm) as well as in the far (1550 nm) infrared. Our experiments support the conclusion that the photorefractivity does not have a distinct red boundary. We show that the maximum saturated refractive index change in the infrared is of the same order of magnitude as in the visible light. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Savchenkov, AA (reprint author), CALTECH, Jet Propuls Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Matsko, Andrey/A-1272-2007 NR 17 TC 13 Z9 13 U1 2 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD DEC PY 2006 VL 74 IS 24 AR 245119 DI 10.1103/PhysRevB.74.245119 PG 4 WC Physics, Condensed Matter SC Physics GA 121ZP UT WOS:000243195800034 ER PT J AU Akutsu, T Akutsu, T Ando, M Arai, K Araya, A Asada, H Aso, Y Barton, MA Beyersdorf, P Fujiki, Y Fujimoto, MK Fujita, R Fukushima, M Futamase, T Hamuro, Y Haruyama, T Hayakawa, H Hayama, K Heinzel, G Horikoshi, G Iguchi, H Iida, Y Ioka, K Ishitsuka, H Kamikubota, N Kanda, N Kaneyama, T Karasawa, Y Kasahara, K Kasai, T Katsuki, M Kawabe, K Kawamura, M Kawamura, S Kawashima, N Kawazoe, F Kojima, Y Kokeyama, K Kondo, K Kozai, Y Kudoh, H Kuroda, K Kuwabara, T Matsuda, N Mio, N Miura, K Miyakawa, O Miyama, S Miyoki, S Mizusawa, H Moriwaki, S Musha, M Nagano, S Nagayama, Y Nakagawa, K Nakamura, T Nakano, H Nakao, K Nishi, Y Numata, K Ogawa, Y Ohashi, M Ohishi, N Okutomi, A Oohara, K Otsuka, S Sago, N Saito, Y Sakata, S Sasaki, M Sato, K Sato, N Sato, S Sato, Y Seki, H Sekido, A Seto, N Shibata, M Shinkai, H Shintomi, T Soida, K Somiya, K Suzuki, T Tagoshi, H Takahashi, H Takahashi, R Takamori, A Takemoto, S Takeno, K Tanaka, T Taniguchi, K Taniguchi, S Tanji, T Tatsumi, D Taylor, CT Telada, S Tochikubo, K Tokunari, M Tomaru, T Tsubono, K Tsuda, N Tsunesada, Y Uchiyama, T Ueda, A Ueda, K Usui, F Waseda, K Watanabe, Y Yakura, H Yamamoto, A Yamamoto, K Yamazaki, T Yanagi, Y Yoda, T Yokoyama, J Yoshida, T Zhu, ZH AF Akutsu, Tomomi Akutsu, Tomotada Ando, Masaki Arai, Koji Araya, Akito Asada, Hideki Aso, Youichi Barton, Mark A. Beyersdorf, Peter Fujiki, Youhei Fujimoto, Masa-Katsu Fujita, Ryuichi Fukushima, Mitsuhiro Futamase, Toshifumi Hamuro, Yusaku Haruyama, Tomiyoshi Hayakawa, Hideaki Hayama, Kazuhiro Heinzel, Gerhard Horikoshi, Gen'ichi Iguchi, Hideo Iida, Yukiyoshi Ioka, Kunihito Ishitsuka, Hideki Kamikubota, Norihiko Kanda, Nobuyuki Kaneyama, Takaharu Karasawa, Yoshikazu Kasahara, Kunihiko Kasai, Taketoshi Katsuki, Mayu Kawabe, Keita Kawamura, Mari Kawamura, Seiji Kawashima, Nobuki Kawazoe, Fumiko Kojima, Yasufumi Kokeyama, Keiko Kondo, Kazuhiro Kozai, Yoshihide Kudoh, Hideaki Kuroda, Kazuaki Kuwabara, Takashi Matsuda, Namio Mio, Norikatsu Miura, Kazuyuki Miyakawa, Osamu Miyama, Shoken Miyoki, Shinji Mizusawa, Hiromi Moriwaki, Shigenori Musha, Mitsuru Nagano, Shigeo Nagayama, Yoshitaka Nakagawa, Ken'ichi Nakamura, Takashi Nakano, Hiroyuki Nakao, Ken-ichi Nishi, Yuhiko Numata, Kenji Ogawa, Yujiro Ohashi, Masatake Ohishi, Naoko Okutomi, Akira Oohara, Ken-ichi Otsuka, Shigemi Sago, Norichika Saito, Yoshio Sakata, Shihori Sasaki, Misao Sato, Kouichi Sato, Nobuaki Sato, Shuichi Sato, Youhei Seki, Hidetsugu Sekido, Aya Seto, Naoki Shibata, Masaru Shinkai, Hisaaki Shintomi, Takakazu Soida, Kenji Somiya, Kentaro Suzuki, Toshikazu Tagoshi, Hideyuki Takahashi, Hirotaka Takahashi, Ryutaro Takamori, Akiteru Takemoto, Shuzo Takeno, Kohei Tanaka, Takahiro Taniguchi, Keisuke Taniguchi, Shinsuke Tanji, Toru Tatsumi, Daisuke Taylor, C. T. Telada, Souichi Tochikubo, Kuniharu Tokunari, Masao Tomaru, Takayuki Tsubono, Kimio Tsuda, Nobuhiro Tsunesada, Yoshiki Uchiyama, Takashi Ueda, Akitoshi Ueda, Ken-ichi Usui, Fumihiko Waseda, Koichi Watanabe, Yuko Yakura, Hiromi Yamamoto, Akira Yamamoto, Kazuhiro Yamazaki, Toshitaka Yanagi, Yuriko Yoda, Tatsuo Yokoyama, Jun'ichi Yoshida, Tatsuru Zhu, Zong-Hong CA TAMA Collaboration TI Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004 SO PHYSICAL REVIEW D LA English DT Article ID GRAVITATIONAL-WAVES; TEMPLATES; DETECTOR; GALAXY; VIRGO; FORMS; LIGO AB We analyze the data of the TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1M-3M. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtain a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effects of various systematic errors such as the uncertainty of the background estimation and the calibration of the detector's sensitivity are included. C1 Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. Univ Tokyo, Dept Astron, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Dept Phys, Tokyo 1130033, Japan. Natl Astron Observ, Mitaka, Tokyo 1818588, Japan. Univ Tokyo, Earthquake Res Inst, Bunkyo Ku, Tokyo 1130032, Japan. Hirosaki Univ, Fac Sci & Technol, Hirosaki, Aomori 0368561, Japan. Niigata Univ, Fac Sci, Niigata 9502102, Japan. Osaka Univ, Grad Sch Sci, Toyonaka, Osaka 5600043, Japan. Tohoku Univ, Grad Sch Sci, Sendai, Miyagi 9808578, Japan. High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. Max Planck Inst Gravitat Phys, D-30167 Hannover, Germany. Tokyo Inst Technol, Meguro Ku, Tokyo 1528551, Japan. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Osaka City Univ, Grad Sch Sci, Sumiyoshi Ku, Osaka 5588585, Japan. LIGO Hanford Observ, Richland, WA 99352 USA. Kyoto Univ, Fac Sci, Sakyo Ku, Kyoto 6068502, Japan. Kinki Univ, Higashiosaka, Osaka 5778502, Japan. Ochanomizu Univ, Bunkyo Ku, Tokyo 1128610, Japan. Hiroshima Univ, Dept Phys, Hiroshima 7398526, Japan. Univ Tokyo, Dept Phys, Theoret Astrophys Grp, Bunkyo Ku, Tokyo 1130033, Japan. Tokyo Denki Univ, Chiyoda Ku, Tokyo 1018457, Japan. Univ Tokyo, Dept Adv Mat Sci, Kashiwa, Chiba 2778561, Japan. Miyagi Univ Educ, Dept Phys, Sendai, Miyagi 9800845, Japan. CALTECH, Pasadena, CA 91125 USA. Univ Electrocommun, Inst Laser Sci, Chofu, Tokyo 1828585, Japan. Natl Inst Informat & Commun Technol, Koganei, Tokyo 1848795, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Kyoto Univ, Yukawa Inst Theoret Phys, Sakyo Ku, Kyoto 6068502, Japan. Tokai Univ, Fac Engn, Div Precis Engn, Hiratsuka, Kanagawa 2591292, Japan. Waseda Univ, Shinjyuku Ku, Tokyo 1698555, Japan. Univ Tokyo, Grad Sch Arts & Sci, Meguro Ku, Tokyo 1538902, Japan. Osaka Inst Technol, Dept Informat Sci, Hirakata, Osaka 5730196, Japan. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Potsdam, Germany. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058563, Japan. JAXA, ISAS, Sagamihara, Kanagawa 2298510, Japan. Univ Tokyo, Grad Sch Sci, Res Ctr Early Universe, Tokyo 1130033, Japan. RP Akutsu, T (reprint author), Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. RI Kawazoe, Fumiko/F-7700-2011; Kawabe, Keita/G-9840-2011; Taniguchi, Keisuke/G-2694-2011; ANDO, MASAKI/G-4989-2014; MIYAMA, Shoken/A-3598-2015; OI ANDO, MASAKI/0000-0002-8865-9998; Nakano, Hiroyuki/0000-0001-7665-0796 NR 30 TC 10 Z9 10 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC PY 2006 VL 74 IS 12 AR 122002 DI 10.1103/PhysRevD.74.122002 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 121QJ UT WOS:000243171800009 ER PT J AU Kristiansen, JR Eriksen, HK Elgaroy, O AF Kristiansen, Jostein R. Eriksen, Hans Kristian Elgaroy, Oystein TI Revised WMAP constraints on neutrino masses and other extensions of the minimal Lambda CDM model SO PHYSICAL REVIEW D LA English DT Article ID POWER SPECTRUM; 2003 FLIGHT; BOOMERANG; GALAXIES AB Recently, two issues concerning the three-year Wilkinson Microwave Anisotropy Probe (WMAP) likelihood code were pointed out. On large angular scales (l less than or similar to 30), a suboptimal likelihood approximation resulted in a small power excess. On small angular scales (l greater than or similar to 300), over-subtraction of unresolved point sources produced a small power deficit. For a minimal six-parameter cosmological model, these two effects conspired to decrease the value of n(s) by similar to 0.7 sigma. In this paper, we study the change in preferred parameter ranges for extended cosmological models, including running of n(s), massive neutrinos, curvature, and the equation of state for dark energy. We also include large-scale structure and supernova data in our analysis. We find that the parameter ranges for alpha(s), Omega(k) and w are not much altered by the modified analysis. For massive neutrinos the upper limit on the sum of the neutrino masses decreases from M-nu < 1.90 eV to M-nu < 1.57 eV when using the modified WMAP code and WMAP data only. We also find that the shift of n(s) to higher values is quite robust to these extensions of the minimal cosmological model. C1 Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Univ Oslo, Ctr Math Appl, N-0315 Oslo, Norway. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. RP Kristiansen, JR (reprint author), Univ Oslo, Inst Theoret Astrophys, Box 1029, N-0315 Oslo, Norway. EM j.r.kristiansen@astro.uio.no; h.k.k.eriksen@astro.uio.no; oelgaroy@astro.uio.no NR 24 TC 17 Z9 17 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC PY 2006 VL 74 IS 12 AR 123005 DI 10.1103/PhysRevD.74.123005 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 121QJ UT WOS:000243171800016 ER PT J AU Tegmark, M Eisenstein, DJ Strauss, MA Weinberg, DH Blanton, MR Frieman, JA Fukugita, M Gunn, JE Hamilton, AJS Knapp, GR Nichol, RC Ostriker, JP Padmanabhan, N Percival, WJ Schlegel, DJ Schneider, DP Scoccimarro, R Seljak, U Seo, HJ Swanson, M Szalay, AS Vogeley, MS Yoo, J Zehavi, I Abazajian, K Anderson, SF Annis, J Bahcall, NA Bassett, B Berlind, A Brinkmann, J Budavari, T Castander, F Connolly, A Csabai, I Doi, M Finkbeiner, DP Gillespie, B Glazebrook, K Hennessy, GS Hogg, DW Ivezic, Z Jain, B Johnston, D Kent, S Lamb, DQ Lee, BC Lin, H Loveday, J Lupton, RH Munn, JA Pan, K Park, C Peoples, J Pier, JR Pope, A Richmond, M Rockosi, C Scranton, R Sheth, RK Stebbins, A Stoughton, C Szapudi, I Tucker, DL Vanden Berk, DE Yanny, B York, DG AF Tegmark, Max Eisenstein, Daniel J. Strauss, Michael A. Weinberg, David H. Blanton, Michael R. Frieman, Joshua A. Fukugita, Masataka Gunn, James E. Hamilton, Andrew J. S. Knapp, Gillian R. Nichol, Robert C. Ostriker, Jeremiah P. Padmanabhan, Nikhil Percival, Will J. Schlegel, David J. Schneider, Donald P. Scoccimarro, Roman Seljak, Uros Seo, Hee-Jong Swanson, Molly Szalay, Alexander S. Vogeley, Michael S. Yoo, Jaiyul Zehavi, Idit Abazajian, Kevork Anderson, Scott F. Annis, James Bahcall, Neta A. Bassett, Bruce Berlind, Andreas Brinkmann, Jon Budavari, Tamas Castander, Francisco Connolly, Andrew Csabai, Istvan Doi, Mamoru Finkbeiner, Douglas P. Gillespie, Bruce Glazebrook, Karl Hennessy, Gregory S. Hogg, David W. Ivezic, Zeljko Jain, Bhuvnesh Johnston, David Kent, Stephen Lamb, Donald Q. Lee, Brian C. Lin, Huan Loveday, Jon Lupton, Robert H. Munn, Jeffrey A. Pan, Kaike Park, Changbom Peoples, John Pier, Jeffrey R. Pope, Adrian Richmond, Michael Rockosi, Constance Scranton, Ryan Sheth, Ravi K. Stebbins, Albert Stoughton, Christopher Szapudi, Istvan Tucker, Douglas L. Vanden Berk, Daniel E. Yanny, Brian York, Donald G. TI Cosmological constraints from the SDSS luminous red galaxies SO PHYSICAL REVIEW D LA English DT Review ID DIGITAL SKY SURVEY; SPECTROSCOPIC TARGET SELECTION; POWER-SPECTRUM ANALYSIS; CFA REDSHIFT SURVEY; MICROWAVE BACKGROUND ANISOTROPIES; PARAMETER-ESTIMATION; COSMIC COMPLEMENTARITY; ACOUSTIC-OSCILLATIONS; INFLATIONARY UNIVERSE; EIGENMODE ANALYSIS AB We measure the large-scale real-space power spectrum P(k) using luminous red galaxies (LRGs) in the Sloan Digital Sky Survey (SDSS) and use this measurement to sharpen constraints on cosmological parameters from the Wilkinson Microwave Anisotropy Probe (WMAP). We employ a matrix-based power spectrum estimation method using Pseudo-Karhunen-Loeve eigenmodes, producing uncorrelated minimum-variance measurements in 20 k-bands of both the clustering power and its anisotropy due to redshift-space distortions, with narrow and well-behaved window functions in the range 0.01h/Mpc < k < 0.2h/Mpc. Results from the LRG and main galaxy samples are consistent, with the former providing higher signal-to-noise. Our results are robust to omitting angular and radial density fluctuations and are consistent between different parts of the sky. They provide a striking confirmation of the predicted large-scale Lambda CDM power spectrum. Combining only SDSS LRG and WMAP data places robust constraints on many cosmological parameters that complement prior analyses of multiple data sets. The LRGs provide independent cross-checks on Omega(m) and the baryon fraction in good agreement with WMAP. Within the context of flat Lambda CDM models, our LRG measurements complement WMAP by sharpening the constraints on the matter density, the neutrino density and the tensor amplitude by about a factor of 2, giving Omega(m)=0.24 +/- 0.02 (1 sigma), (95%) and r < 0.3 (95%). Baryon oscillations are clearly detected and provide a robust measurement of the comoving distance to the median survey redshift z=0.35 independent of curvature and dark energy properties. Within the Lambda CDM framework, our power spectrum measurement improves the evidence for spatial flatness, sharpening the curvature constraint Omega(tot)=1.05 +/- 0.05 from WMAP alone to Omega(tot)=1.003 +/- 0.010. Assuming Omega(tot)=1, the equation of state parameter is constrained to w=-0.94 +/- 0.09, indicating the potential for more ambitious future LRG measurements to provide precision tests of the nature of dark energy. All these constraints are essentially independent of scales k > 0.1h/Mpc and associated nonlinear complications, yet agree well with more aggressive published analyses where nonlinear modeling is crucial. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. NYU, Dept Phys, Ctr Cosmol & Particle Phys, New York, NY 10003 USA. Univ Chicago, Ctr Cosmol Phys, Chicago, IL 60637 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Astrophys & Planetry Sci, Boulder, CO 80309 USA. Univ Portsmouth, Inst Cosmol & Gravitat, Portsmouth P01 2EG, Hants, England. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Abdus Salaam Int Ctr Theoret Phys, I-34014 Trieste, Italy. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. Case Western Reserve Univ, Dept Astron, Cleveland, OH 44106 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. S African Astron Observ, ZA-7935 Cape Town, South Africa. Univ Cape Town, Dept Appl Math, ZA-7925 Cape Town, South Africa. Apache Point Observ, Sunspot, NM 88349 USA. CSIC, Inst Estudis Espacials Catalunya, ES-08034 Barcelona, Spain. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Univ Tokyo, Inst Astron, Tokyo 1810015, Japan. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. US Geol Survey, Flagstaff Stn, Flagstaff, AZ 86001 USA. Univ Penn, Dept Phys, Philadelphia, PA 19104 USA. Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Gatan Inc, Pleasanton, CA 94588 USA. Univ Sussex, Sussex Astron Ctr, Brighton BN1 9QJ, E Sussex, England. Seoul Natl Univ, Dept Astron, Seoul 151742, South Korea. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Tegmark, M (reprint author), MIT, Dept Phys, Cambridge, MA 02139 USA. RI Padmanabhan, Nikhil/A-2094-2012; Csabai, Istvan/F-2455-2012; Glazebrook, Karl/N-3488-2015; OI Glazebrook, Karl/0000-0002-3254-9044; Csabai, Istvan/0000-0001-9232-9898; Hogg, David/0000-0003-2866-9403; Tucker, Douglas/0000-0001-7211-5729 NR 184 TC 956 Z9 963 U1 1 U2 19 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC PY 2006 VL 74 IS 12 AR 123507 DI 10.1103/PhysRevD.74.123507 PG 34 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 121QJ UT WOS:000243171800028 ER PT J AU Buldyrev, SV Ferrante, J Zypman, FR AF Buldyrev, Sergey V. Ferrante, John Zypman, Fredy R. TI Dry friction avalanches: Experiment and theory SO PHYSICAL REVIEW E LA English DT Article ID SELF-ORGANIZED CRITICALITY; MOLECULAR-DYNAMICS SIMULATIONS; ATOMIC-SCALE FRICTION; ENERGY-DISSIPATION; ELASTIC MEDIA; 1/F NOISE; EVOLUTION; SURFACES; MODELS AB Experimental evidence and theoretical models are presented supporting the conjecture that dry friction stick-slip is described by self-organized criticality. We use the data, obtained with a pin-on-disk tribometer set to measure lateral force, to examine the variation of the friction force as a function of time. We study nominally flat surfaces of matching aluminum and steel. The probability distribution of force drops follows a negative power law with exponents mu in the range 3.2-3.5. The frequency power spectrum follows a 1/f(alpha) pattern with alpha in the range 1-1.8. We first compare these experimental results with the well-known Robin Hood model of self-organized criticality. We find good agreement between theory and experiment for the force-drop distribution but not for the power spectrum. We explain this on a physical basis and propose a model which takes explicitly into account the stiffness and inertia of the tribometer. Specifically, we numerically solve the equation of motion of a block on a friction surface pulled by a spring and show that for certain spring constants the motion is characterized by the same power law spectrum as in experiments. We propose a physical picture relating the fluctuations of the force drops to the microscopic geometry of the surface. C1 Yeshiva Univ, Dept Phys, New York, NY 10033 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Buldyrev, SV (reprint author), Yeshiva Univ, Dept Phys, 2495 Amsterdam Ave, New York, NY 10033 USA. RI Buldyrev, Sergey/I-3933-2015 NR 45 TC 13 Z9 13 U1 0 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD DEC PY 2006 VL 74 IS 6 AR 066110 DI 10.1103/PhysRevE.74.066110 PN 2 PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 121OC UT WOS:000243165900015 PM 17280124 ER PT J AU Hesse, M AF Hesse, Michael TI Dissipation in magnetic reconnection with a guide magnetic field SO PHYSICS OF PLASMAS LA English DT Article ID PARALLEL ELECTRIC-FIELDS; THIN CURRENT SHEETS; SIMULATIONS; CHALLENGE; ANTIPARALLEL; ONSET; FLUX AB A combination of numerical simulation results and analytical theory is applied to the problem of magnetic reconnection in a guide magnetic field. An investigation of electron distribution functions within the electron diffusion region leads to a picture of mixing of particles with different acceleration histories on electron Larmor scales. Based on an apparent average loss of accelerated particles by field-aligned and ExB transport, it is proposed that the role of the reconnection electric field is to replenish this loss by acceleration of particles that enter the electron diffusion region. Analytic theory is employed to verify this model, and an equation is derived, which balances the average electric field force density by a diffusion term applied to the electron momentum density. The diffusion coefficient contains explicitly the electron Larmor spatial scale and a poloidal transport time scale. (c) 2006 American Institute of Physics. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hesse, M (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Hesse, Michael/D-2031-2012; NASA MMS, Science Team/J-5393-2013 OI NASA MMS, Science Team/0000-0002-9504-5214 NR 18 TC 28 Z9 28 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2006 VL 13 IS 12 AR 122107 DI 10.1063/1.2403784 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 121LJ UT WOS:000243158800010 ER PT J AU Buratti, BJ Sotin, C Brown, RH Hicks, MD Clark, RN Mosher, JA McCord, TB Jaumann, R Baines, KH Nicholson, PD Momary, T Simonelli, DP Sicardy, B AF Buratti, B. J. Sotin, C. Brown, R. H. Hicks, M. D. Clark, R. N. Mosher, J. A. McCord, T. B. Jaumann, R. Baines, K. H. Nicholson, P. D. Momary, T. Simonelli, D. P. Sicardy, B. TI Titan: Preliminary results on surface properties and photometry from VIMS observations of the early flybys SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Titan; Saturnian satellites; Cassini mission ID MULTIPLE-SCATTERING; ROUGHNESS; SATELLITES; CURVE; LIGHT AB Cassini observations of the surface of Titan offer unprecedented views of its surface through atmospheric windows in the 1-5 mu m region. Images obtained in windows for which the haze opacity is low can be used to derive quantitative photometric parameters such as albedo and albedo distribution, and physical properties such as roughness and particle characteristics. Images from the early Titan flybys, particularly TO, Ta, and T5 have been analyzed to create albedo maps in the 2.01 and 2.73 mu m windows. We find the average normal reflectance at these two wavelengths to be 0.15 +/- 0.02 and 0.035 +/- 0.003, respectively. Titan's surface is bifurcated into two albedo regimes, particularly at 2.01 mu m. Analysis of these two regimes to understand the physical character of the surface was accomplished with a macroscopic roughness model. We find that the two types of surface have substantially different roughness, with the low-albedo surface exhibiting mean slope angles of similar to 18 degrees, and the high-albedo terrain having a much more substantial roughness with a mean slope angle of similar to 34 degrees. A single-scattering phase function approximated by a one-term Henyey-Greenstein equation was also fit to each unit. Titan's surface is back-scattering (g similar to 0.3-0.4), and does not exhibit substantially different backscattering behavior between the two terrains. Our results suggest that two distinct geophysical domains exist on Titan: a bright region cut by deep drainage channels and a relatively smooth surface. The two terrains are covered by a film or a coating of particles perhaps precipitated from the satellite's haze layer and transported by eolian processes. Our results are preliminary: more accurate values for the surface albedo and physical parameters will be derived as more data is gathered by the Cassini spacecraft and as a more complete radiative transfer model is developed from both Cassini orbiter and Huygens Lander measurements. (c) 2006 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Nantes, F-44072 Nantes 3, France. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Univ Arizona, LPL, Tucson, AZ 85721 USA. US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA. Space Sci Inst, Winthrop, WA 98862 USA. DLR, Inst Planet Expl, D-12489 Berlin, Germany. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Observ Paris, F-92195 Meudon, France. RP Buratti, BJ (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-501, Pasadena, CA 91109 USA. EM bonnie.buratti@jpl.nasa.gov NR 29 TC 12 Z9 12 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2006 VL 54 IS 15 BP 1498 EP 1509 DI 10.1016/j.pss.2006.06.015 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 117YF UT WOS:000242908500002 ER PT J AU Rodriguez, S Le Mouelic, S Sotin, C Clenet, H Clark, RN Buratti, B Brown, RH McCord, TB Nicholson, PD Baines, KH AF Rodriguez, S. Le Mouelic, S. Sotin, C. Clenet, H. Clark, R. N. Buratti, B. Brown, R. H. McCord, T. B. Nicholson, P. D. Baines, K. H. CA VIMS Science Team TI Cassini/VIMS hyperspectral observations of the HUYGENS landing site on Titan SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Titan; satellites; near-infrared; spectro-imaging; VIMS ID VERTICAL-DISTRIBUTION; ATMOSPHERE; SURFACE; SPECTROSCOPY; AEROSOLS; DESCENT AB Titan is one of the primary scientific objectives of the NASA-ESA-ASI Cassini-Huygens mission. Scattering by haze particles in Titan's atmosphere and numerous methane absorptions dramatically veil Titan's surface in the visible range, though it can be studied more easily in some narrow infrared windows. The Visual and Infrared Mapping Spectrometer (VIMS) instrument onboard the Cassini spacecraft successfully imaged its surface in the atmospheric windows, taking hyperspectral images in the range 0.4-5.2 mu m. On 26 October (TA flyby) and 13 December 2004 (TB flyby), the Cassini-Huygens mission flew over Titan at an altitude lower than 1200 km at closest approach. We report here on the analysis of VIMS images of the Huygens landing site acquired at TA and TB, with a spatial resolution ranging from 16 to 14.4 km/pixel. The pure atmospheric backscattering component is corrected by using both an empirical method and a first-order theoretical model. Both approaches provide consistent results. After the removal of scattering, ratio images reveal subtle surface heterogeneities. A particularly contrasted structure appears in ratio images involving the 1.59 and 2.03 mu m images north of the Huygens landing site. Although pure water ice cannot be the only component exposed at Titan's surface, this area is consistent with a local enrichment in exposed water ice and seems to be consistent with DISR/Huygens images and spectra interpretations. The images show also a morphological structure that can be interpreted as a 150 km diameter impact crater with a central peak. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Nantes, UMR CNRS 6112, Lab Planetol & Geodynam, F-44322 Nantes 3, France. US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA. CALTECH, JPL, Pasadena, CA 91125 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. RP Rodriguez, S (reprint author), Univ Nantes, UMR CNRS 6112, Lab Planetol & Geodynam, 2 Rue Houssinier,BP 92208, F-44322 Nantes 3, France. EM Sebastien.Rodriguez@univ-nantes.fr RI Clenet, Harold/B-7621-2016; Rodriguez, Sebastien/H-5902-2016 OI Clenet, Harold/0000-0002-6743-7798; Rodriguez, Sebastien/0000-0003-1219-0641 NR 28 TC 53 Z9 53 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2006 VL 54 IS 15 BP 1510 EP 1523 DI 10.1016/j.pss.2006.06.016 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 117YF UT WOS:000242908500003 ER PT J AU McCord, TB Hansen, GB Buratti, BJ Clark, RN Cruikshank, DP D'Aversa, E Griffith, CA Baines, EH Brown, RH Ore, CMD Filacchione, G Formisano, V Hibbitts, CA Jaumann, R Lunine, JI Nelson, RM Sotin, C AF McCord, T. B. Hansen, G. B. Buratti, B. J. Clark, R. N. Cruikshank, D. P. D'Aversa, E. Griffith, C. A. Baines, Ex. H. Brown, R. H. Ore, C. M. Dalle Filacchione, G. Formisano, V. Hibbitts, C. A. Jaumann, R. Lunine, J. I. Nelson, R. M. Sotin, C. CA VIMS Team TI Composition of Titan's surface from Cassini VIMS SO PLANETARY AND SPACE SCIENCE LA English DT Article DE satellites; Titan; surface; composition; Cassini; spectroscopy ID GALILEAN SATELLITES; ATMOSPHERE; IMAGES; MODEL; HAZE; SPECTROSCOPY; THOLINS; SPECTRA; OCEAN; WINDS AB Titan's bulk density along with Solar System formation models indicates considerable water as well as silicates as its major constituents. This satellite's dense atmosphere of nitrogen with methane is unique. Deposits or even oceans of organic compounds have been suggested to exist on Titan's solid surface due to Uv-induced photochemistry in the atmosphere. Thus, the composition of the surface is a major piece of evidence needed to determine Titan's history. However, studies of the surface are hindered by the thick, absorbing, hazy and in some places cloudy atmosphere. Ground-based telescope investigations of the integral disk of Titan attempted to observe the surface albedo in spectral windows between methane absorptions by calculating and removing the haze effects. Their results were reported to be consistent with water ice on the surface that is contaminated with a small amount of dark material, perhaps organic material like tholin. We analyze here the recent Cassini Mission's visual and infrared mapping spectrometer (VIMS) observations that resolve regions on Titan. VIMS is able to see surface features and shows that there are spectral and therefore likely compositional units. By several methods, spectral albedo estimates within methane absorption windows between 0.75 and 5 mu m were obtained for different surface units using VIMS image cubes from the Cassini-Huygens Titan T. encounter. Of the spots studied, there appears to be two compositional classes present that are associated with the lower albedo and the higher albedo materials, with some variety among the brighter regions. These were compared with spectra of several different candidate materials. Our results show that the spectrum of water ice contaminated with a darker material matches the reflectance of the lower albedo Titan regions if the spectral slope from 2.71 to 2.79 mu m in the poorly understood 2.8-mu m methane window is ignored. The spectra for brighter regions are not matched by the spectrum of water ice or unoxidized tholin, in pure form or in mixtures with sufficient ice or tholin present to allow the water ice or tholin spectral features to be discerned. We find that the 2.8-mu m methane absorption window is complex and seems to consist of two weak subwindows at 2.7 and 2.8 mu m that have unknown opacities. A ratio image at these two wavelengths reveals an anomalous region on Titan that has a reflectance unlike any material so far identified, but it is unclear how much the reflectances in these two subwindows pertain to the surface. (c) 2006 Elsevier Ltd. All rights reserved. C1 Space Sci Inst NW, Winthrop, WA 98862 USA. Univ Washington, Dept E&Sp Sci, Seattle, WA 98195 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA. NASA, Ames Res Ctr, Astrophys Branch, Moffett Field, CA 94035 USA. CNR, Inst Fis Spazio Interplanterio, Rome, Italy. Univ Arizona, Dept Pl Sci & LPL, Tucson, AZ 85721 USA. SETI Inst, Mountain View, CA 94043 USA. Johns Hopkins Univ, Appl Phys Lab, Baltimore, MD 21218 USA. DLR, Inst Planet, D-12489 Berlin, Germany. Univ Nantes, F-44072 Nantes 3, France. RP McCord, TB (reprint author), Space Sci Inst NW, 22 Fiddler Rd, Winthrop, WA 98862 USA. EM mccordtb@aol.com RI Hibbitts, Charles/B-7787-2016; OI Hibbitts, Charles/0000-0001-9089-4391; Filacchione, Gianrico/0000-0001-9567-0055; D'Aversa, Emiliano/0000-0002-5842-5867 NR 37 TC 60 Z9 61 U1 1 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2006 VL 54 IS 15 BP 1524 EP 1539 DI 10.1016/j.pss.2006.06.007 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 117YF UT WOS:000242908500004 ER PT J AU Nelson, RM Brown, RH Hapke, BW Smythe, WD Kamp, L Boryta, MD Leader, F Baines, KH Bellucci, G Bibring, JP Buratti, BJ Capaccioni, F Cerroni, P Clark, RN Combes, M Coradini, A Cruikshank, DP Drossart, P Formisano, V Jaumann, R Langevin, Y Matson, DL McCord, TB Mennella, V Nicholson, PD Sicardy, B Sotin, C AF Nelson, R. M. Brown, R. H. Hapke, B. W. Smythe, W. D. Kamp, L. Boryta, M. D. Leader, F. Baines, K. H. Bellucci, G. Bibring, J. -P. Buratti, B. J. Capaccioni, F. Cerroni, P. Clark, R. N. Combes, M. Coradini, A. Cruikshank, D. P. Drossart, P. Formisano, V. Jaumann, R. Langevin, Y. Matson, D. L. McCord, T. B. Mennella, V. Nicholson, P. D. Sicardy, B. Sotin, C. TI Photometric properties of Titan's surface from Cassini VIMS: Relevance to titan's hemispherical albedo dichotomy and surface stability SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Titan; Cassini; Satrunian satellites ID ATMOSPHERE; EMISSION; ORGANICS; IMAGES; EJECTA; MELT AB The Visual and Infrared Mapping Spectrometer (VIMS) instrument on the Cassini Saturn Orbiter returned spectral imaging data as the spacecraft undertook six close encounters with Titan beginning 7 July, 2004. Three of these flybys each produced overlapping coverage of two distinct regions of Titan's surface. Twenty-four points were selected on approximately opposite hemispheres to serve as photometric controls. Six points were selected in each of four reflectance classes. On one hemisphere each control point was observed at three distinct phase angles. From the derived phase coefficients, preliminary normal reflectances were derived for each reflectance class. The normal reflectance of Titan's surface units at 2.0178 mu m ranged from 0.079 to 0.185 for the most absorbing to the most reflective units assuming no contribution from absorbing haze. When a modest haze contribution of tau = 0.1 is considered these numbers increase to 0.089-0.215. We find that the lowest three reflectance classes have comparable normal reflectance on either hemisphere. However, for the highest brightness class the normal reflectance is higher on the hemisphere encompassing longitude 14-65 degrees compared to the same high brightness class for the hemisphere encompassing 122-156 degrees longitude. We conclude that an albedo dichotomy observed in continental sized units on Titan is due not only to one unit having more areal coverage of reflective material than the other but the material on the brighter unit is intrinsically more reflective than the most reflective material on the other unit. This suggests that surface renewal processes are more widespread on Titan's more reflective units than on its less reflective units. We note that one of our photometric control points has increased in reflectance by 12% relative to the surrounding terrain from July of 2004 to April and May of 2005. Possible causes of this effect include atmospheric processes such as ground fog or orographic clouds; the suggestion of active volcanism cannot be ruled out. Several interesting circular features which resembled impact craters were identified on Titan's surface at the time of the initial Titan flyby in July of 2004. We traced photometric profiles through two of these candidate craters and attempted to fit these profiles to the photometric properties expected from model depressions. We find that the best-fit attempt to model these features as craters requires that they be unrealistically deep, approximately 70 km deep. We conclude that despite their appearance, these circular features are not craters, however, the possibility that they are palimpsests cannot be ruled out. We used two methods to test for the presence of vast expanses of liquids on Titan's surface that had been suggested to resemble oceans. Specular reflection of sunlight would be indicative of widespread liquids on the surface; we found no evidence of this. A large liquid body should also show uniformity in photometric profile; we found the profiles to be highly variable. The lack of specular reflection and the high photometric variability in the profiles across candidate oceans is inconsistent with the presence of vast expanses of flat-lying liquids on Titan's surface. While liquid accumulation may be present as small, sub-pixel-sized bodies, or in areas of the surface which still remain to be observed by VIMS, the presence of large ocean-sized accumulations of liquids can be ruled out. The Cassini orbital tour offers the opportunity for VIMS to image the same parts of Titan's surface repeatedly at many different illumination and observation geometries. This creates the possibility of understanding the properties of Titan's atmosphere and haze by iteratively adapting models to create a best fit to the surface reflectance properties. (c) 2006 Elsevier Ltd. All rights reserved. C1 NASA, JPL, Pasadena, CA USA. Univ Arizona, Tucson, AZ 85721 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Mt San Antonio Coll, Walnut, CA USA. Univ Paris 11, Orsay, France. USGS, Denver, CO USA. Observ Paris, Meudon, France. NASA, AMES, Mountain View, CA USA. DLR, Inst Planetary Explorat, Berlin, Germany. Univ Hawaii, Honolulu, HI 96822 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Nantes, F-44035 Nantes, France. RP Nelson, RM (reprint author), NASA, JPL, Pasadena, CA USA. EM robert.m.nelson@jpl.nasa.gov OI Capaccioni, Fabrizio/0000-0003-1631-4314; Cerroni, Priscilla/0000-0003-0239-2741; Bellucci, Giancarlo/0000-0003-0867-8679 NR 28 TC 6 Z9 6 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2006 VL 54 IS 15 BP 1540 EP 1551 DI 10.1016/j.pss.2006.06.014 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 117YF UT WOS:000242908500005 ER PT J AU Baines, KH Drossart, P Lopez-Valverde, MA Atreya, SK Sotin, C Momary, TW Brown, RH Buratti, BJ Clark, RN Nicholson, PD AF Baines, Kevin H. Drossart, Pierre Lopez-Valverde, Miguel A. Atreya, Sushil K. Sotin, Christophe Momary, Thomas W. Brown, Robert H. Buratti, Bonnie J. Clark, Roger N. Nicholson, Philip D. TI On the discovery of CO nighttime emissions on Titan by Cassini/VIMS: Derived stratospheric abundances and geological implications SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Cassini; VIMS; Titan; CO; volcanism ID VOYAGER INFRARED OBSERVATIONS; SUBMILLIMETER HETERODYNE OBSERVATIONS; MIXED VERTICAL PROFILE; CARBON-MONOXIDE; ATMOSPHERE; PHOTOCHEMISTRY; SURFACE; CONSTITUENTS; HYDROCARBONS; MILLIMETER AB We present a quantitative analysis of CO thermal emissions discovered on the nightside of Titan by Baines et al. [2005. The atmospheres of Saturn and Titan in the near-infrared: First results of Cassini/VIMS. Earth, Moon, and Planets, 96, 119-147]. in Cassini/VIMS spectral imagery. We identify these emission features as the P and R branches of the 1-0 vibrational band of carbon monoxide (CO) near 4.65 mu m. For CH3D, the prominent Q branch of the nu(2) fundamental band of CH3D near 4.55 mu m is apparent. CO2 emissions from the strong nu(3) vibrational band are virtually absent, indicating a CO2 abundance several orders of magnitude less than CO, in agreement with previous investigations. Analysis of CO emission spectra obtained over a variety of altitudes on Titan's nightside limb indicates that the stratospheric abundance of CO is 32 +/- 15 ppm, and together with other recent determinations, suggests a vertical distribution of CO nearly constant at this value from the surface throughout the troposphere to at least the stratopause near 300 kin altitude. The corresponding total atmospheric content of CO in Titan is similar to 2.9 +/- 1.5 x 10(14) kg. Given the long lifetime of CO in the oxygen-poor Titan atmosphere (similar to 0.5-1.0 Gyr), we find a mean CO atmospheric production rate of 6 +/- 3 x 105 kg yr(-1). Given the lack of primordial heavy noble gases observed by Huygens [Niemann et al., 2005. The abundances of constituents of Titan's atmosphere from the GCMS on the Huygens probe. Nature, 438, 779-784], the primary source of atmospheric CO is likely surface emissions. The implied CO/CH4 mixing ratio of near-surface material is 1.8 +/- 0.9 X 10(-4), based on an average methane surface emission rate over the past 0.5Gyr of 1.3 x 10(-13) gm cm(-2) s(-1) as required to balance hydrocarbon haze production via methane photolysis [Wilson and Atreya, 2004. Current state of modeling the photochemistry of Titan's mutually dependent atmosphere and ionosphere. J. Geophys. Res. 109, E06002 Doi: 10.1029/2003JE002181]. This low CO/CH4 ratio is much lower than expected for the sub-nebular formation region of Titan and supports the hypothesis [e.g., Atreya et al., 2005. Methane on Titan: photochemical-meteorological-hydrogeochemical cycle. Bull. Am. Astron. Soc. 37, 735] that the conversion of primordial CO and other carbon-bearing materials into CH4-enriched clathrate-hydrates occurs within the deep interior of Titan via the release of hydrogen through the serpentinization process followed by Fischer-Tropsch catalysis. The time-averaged predicted emission rate of methane-rich surface materials is similar to 0.02km(3) yr(-1), a value significantly lower than the rate of silicate lava production for the Earth and Venus, but nonetheless indicative of significant active geological processes reshaping the surface of Titan. (c) 2006 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Observ Paris, CNRS UMR 8109, LESIA, Meudon, France. Inst Astrofis Andalucia, E-18080 Granada, Spain. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Univ Nantes, UMR CNRS 6112, Fac Sci, Lab Planetol & Geodynam, F-44072 Nantes 03, France. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. US Geol Survey, Fed Ctr, Lakewood, CO 80225 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. RP Baines, KH (reprint author), CALTECH, Jet Prop Lab, M-S 183-601,183-601,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM kbaines@aloha.jpl.nasa.gov; Pierre.Drossart@obspm.fr; valverde@iaa.es; atreya@umich.edu; sotin@chimie.univ-nantes.fr; momary@mail1.jpl.nasa.gov; rhb@lpl.arizona.edu; bonnie.buratti@jpl.nasa.gov; rclark@usgs.gov; nicholso@astro.cornell.edu OI Lopez-Valverde, M. A./0000-0002-7989-4267 NR 43 TC 26 Z9 26 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2006 VL 54 IS 15 BP 1552 EP 1562 DI 10.1016/j.pss.2006.06.020 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 117YF UT WOS:000242908500006 ER PT J AU Glavin, DP Cleaves, HJ Buch, A Schubert, M Aubrey, A Bada, JL Mahaffy, PR AF Glavin, D. P. Cleaves, H. J. Buch, A. Schubert, M. Aubrey, A. Bada, J. L. Mahaffy, P. R. TI Sublimation extraction coupled with gas chromatography-mass spectrometry: A new technique for future in situ analyses of purines and pyrimidines on Mars SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 14th Annual V M Goldschmidt Conference CY JUN 05-11, 2004 CL Univ Copenhagen, Copenhagen, DENMARK SP European Assoc Geochem, Geochem Soc, Geochem Soc Japan, Mineralog Soc Amer HO Univ Copenhagen DE gas chromatography-mass spectrometry (GC-MS); Mars; nucleobases; sublimation; bacteria; Atacama ID AMINO-ACIDS; MURCHISON METEORITE; ORGANIC-COMPOUNDS; NATURAL SAMPLES; MICROBIAL LIFE; ATACAMA DESERT; BACTERIA; SEDIMENTS; SEARCH AB We have developed a sublimation technique coupled with chemical derivatization and gas chromatography mass spectrometry (GC-MS) to detect nucleobases and other volatile organic compounds derived from bacteria in Mars analog materials. To demonstrate this technique, a sample of serpentine inoculated with Escherichia coli (E coli) cells was heated to 500 degrees C for several seconds under Martian ambient pressure. The sublimate was collected on a cold finger, then derivatized and analyzed by GC-MS. We found that adenine, cytosine, thymine and uracil were the most abundant molecules detected in the sublimed E coli extract by GC-MS. In addition, nucleobases were also detected in sublimed extracts of a deep-sea sediment sample, seawater, and soil collected from the Atacama Desert in Chile after heating the samples under the same conditions. Our results indicate that nucleobases can be easily isolated directly from natural samples using sublimation and then detected by GC-MS after chemical derivatization. The sublimation-based extraction technique is one approach that should be considered for use by future in situ instruments designed to detect organic compounds relevant to life in the Martian regolith. (c) 2006 Elsevier Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Lab Interuniv Syst Atmospher, CNRS UMR7583, F-94010 Creteil, France. Ecole Normale Super Lyon, CNRS UMR5161, F-69364 Lyon 07, France. RP Glavin, DP (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM daniel.p.glavin@nasa.gov RI Mahaffy, Paul/E-4609-2012; Glavin, Daniel/D-6194-2012; OI Glavin, Daniel/0000-0001-7779-7765; Cleaves, Henderson/0000-0003-4101-0654 NR 30 TC 8 Z9 8 U1 2 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2006 VL 54 IS 15 BP 1584 EP 1591 DI 10.1016/j.pss.2005.12.023 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 117YF UT WOS:000242908500011 ER PT J AU Buch, A Glavin, DP Sternberg, R Szopa, C Rodier, C Navarro-Gonzalez, R Raulin, F Cabane, M Mahaffy, PR AF Buch, A. Glavin, D. P. Sternberg, R. Szopa, C. Rodier, C. Navarro-Gonzalez, R. Raulin, F. Cabane, M. Mahaffy, P. R. TI A new extraction technique for in situ analyses of amino and carboxylic acids on Mars by gas chromatography mass spectrometry SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 14th Annual V M Goldschmidt Conference CY JUN 05-11, 2004 CL Univ Copenhagen, Copenhagen, DENMARK SP European Assoc Geochem, Geochem Soc, Geochem Soc Japan, Mineralog Soc Amer HO Univ Copenhagen DE derivatization; extraction solid-liquid; GC-MS; amino acids; carboxylic acids; ultrasound; Mars; isopropanol; water; Atacama ID SAMPLE PREPARATION METHOD; SOLVENT-EXTRACTION; ASSISTED EXTRACTION; ORGANIC-MOLECULES; ACTIVE COMPOUNDS; MARTIAN SOIL; ULTRASOUND; SEDIMENTS; LIFE AB In order to target key organic compounds in the Martian regolith using gas chromatography mass spectrometry (GC-MS), we have developed a new extraction procedure coupled with chemical derivatization. This new technique was tested on a Mars analog soil sample collected from the Atacama Desert in Chile. We found that amino and carboxylic acids can be extracted from the Atacama soil in a 1:1 mixture of isopropanol and water after ultrasonic treatment for 30 min. The extracted organic compounds were then derivatized in a single-step reaction using N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA) as the silylating agent in order to transform these compounds into volatile species that can then be detected by GC-MS. We are currently developing a miniaturized reaction cell suited for spaceflight, where both organic extraction and chemical derivatization processes can take place in a single step. (c) 2006 Elsevier Ltd. All rights reserved. C1 Ecole Cent Paris, Lab Chim & Gen Procedes, F-92295 Chatenay Malabry, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Paris 7 12, UMR 7583 CNRS, Lab Interuniv Syst Atmospher, F-94010 Creteil, France. IPSL, SA, F-91371 Verrieres Le Buisson, France. Lab Synth & React Subst Nat, F-86022 Poitiers, France. Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Lab Quim Plasmas & Estudios Planetarios, Mexico City 04510, DF, Mexico. RP Buch, A (reprint author), Ecole Cent Paris, LGPM, Grande Voie Vignes, F-92295 Chatenay Malabry, France. EM arnaud.buch@ecp.fr RI Gonzalez, Rafael/D-1748-2009; Mahaffy, Paul/E-4609-2012; Glavin, Daniel/D-6194-2012; szopa, cyril/C-6865-2015 OI Glavin, Daniel/0000-0001-7779-7765; szopa, cyril/0000-0002-0090-4056 NR 36 TC 28 Z9 31 U1 2 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2006 VL 54 IS 15 BP 1592 EP 1599 DI 10.1016/j.pss.2006.05.041 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 117YF UT WOS:000242908500012 ER PT J AU Hall, JA Felnagle, E Fries, M Spearing, S Monaco, L Steele, A AF Hall, J. A. Felnagle, E. Fries, M. Spearing, S. Monaco, L. Steele, A. TI Evaluation of cell lysis procedures and use of a micro fluidic system for an automated DNA-based cell identification in interplanetary missions SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 14th Annual V M Goldschmidt Conference CY JUN 05-11, 2004 CL Univ Copenhagen, Copenhagen, DENMARK SP European Assoc Geochem, Geochem Soc, Geochem Soc Japan, Mineralog Soc Amer HO Univ Copenhagen DE life detection; cell lysis; FTA paper; microfluidic ID MARTIAN METEORITE ALH84001; MICROFLUIDIC DEVICES; TEMPLATE PREPARATION; LAKE VOSTOK; MICROORGANISMS; EXTRACTION; TRANSPORT; BACTERIA; MARS; LIFE AB A Modular Assay System for Solar System Exploration (MASSE) is being developed to include sample handling, pre-treatment, separation and analysis of biological target compounds by both DNA and protein microarrays. To better design sensitive and accurate initial upstream sample handling of the MASSE instrument, experiments investigating the sensitivity and potential extraction bias of commercially available DNA extraction kits between classes of environmentally relevant prokaryotes such as gram-negative bacteria (Escherichia coli), gram-positive bacteria (Bacillus megatarium), and Archaea (Haloarcula marismortui) were performed. For extractions of both planktonic cultures and spiked Mars simulated regolith, FTA (R) paper demonstrated the highest sensitivity, with detection as low as similar to 1 x 10(1) cells and similar to 3.3 x 10(2) cells, respectively. In addition to the highest sensitivity, custom modified application of FTA (R) paper extraction protocol is the simplest in terms of incorporation into MASSE and displayed little bias in sensitivity with respect to prokaryotic cell type. The implementation of FTA paper for environmental microbiology investigations appears to be a viable and effective option potentially negating the need for other pre-concentration steps such as filtration and negating concerns regarding extraction efficiency of cells. In addition to investigations on useful technology for upstream sample handling in MASSE, we have also evaluated the potential for mu TAS to be employed in the MASSE instrument by employing proprietary lab-on-a-chip development technology to investigate the potential for microfluidic cell lysis of different prokaryotic cells employing both chemical and biological lysis agents. Real-time bright-field microscopy and quantitative PMT detection indicated that that gram positive, gram negative and archaeal cells were effectively lyzed in a few seconds using the microfluidic chip protocol developed. This included employing a lysis buffer with components including lysozyme, Protease, Proteinase K, Tween-20 and TritonX-100. The effectiveness of antibiotics and other chemical lysis agents were also screened and demonstrated partial effectiveness on all three cell types. This work demonstrates a step wise approach to evaluating the efficacy and sensitivity of commercial macro-scale technology and state-of-the-art developmental microfluidic technology under consideration for incorporation into the remotely operated MASSE instrument currently under development at the Carnegie Institution of Washington. (c) 2006 Published by Elsevier Ltd. C1 Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. CALTECH, Pasadena, CA 91125 USA. NASA, George C Marshall Space Flight Ctr, LOCAD, Huntsville, AL 35812 USA. RP Steele, A (reprint author), Carnegie Inst Washington, Geophys Lab, 5251 Broad Branch Rd NW, Washington, DC 20015 USA. EM a.steele@gl.ciw.edu NR 37 TC 12 Z9 12 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2006 VL 54 IS 15 BP 1600 EP 1611 DI 10.1016/j.pss.2006.06.021 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 117YF UT WOS:000242908500013 ER PT J AU Johnston, JC Kuczmarski, MA AF Johnston, James C. Kuczmarski, Maria A. TI N-15 NMR spectroscopy as a method for comparing the rates of imidization of several diamines SO POLYMER COMPOSITES LA English DT Article ID POLYIMIDES AB The relative rates of the conversion of amide-acid to imide were measured for a series or aromatic diamines that have been identified as potential replacements for 4,4'-methylene dianiline (MDA) in high-temperature polyimides and polymer composites. These rates were compared with the N-15 NMR resonances of the unreacted amines. The initial rates of imidization track with the difference in chemical shift between the amine nitrogens in MDA and those in the subject diamines. This comparison demonstrated that N-15 NMR spectroscopy is appropriate for the rapid screening of candidate diamines to determine their reactivity relative to MDA, and can serve to provide guidance to the process of creating the time-temperature profiles used in processing these materials into polymer matrix composites. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Johnston, JC (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM James.C.Johnston1@nasa.gov NR 12 TC 2 Z9 2 U1 0 U2 2 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0272-8397 J9 POLYM COMPOSITE JI Polym. Compos. PD DEC PY 2006 VL 27 IS 6 BP 723 EP 729 DI 10.1002/pc.20261 PG 7 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 112BO UT WOS:000242500300016 ER PT J AU Meyer, MR Hillenbrand, LA Backman, D Beckwith, S Bouwman, J Brooke, T Carpenter, J Cohen, M Cortes, S Crockett, N Gorti, U Henning, T Hines, D Hollenbach, D Kim, JS Lunine, J Malhotra, R Mamajek, E Metchev, S Moro-Martin, A Morris, P Najita, J Padgett, D Pascucci, I Rodmann, J Schlingman, W Silverstone, M Soderblom, D Stauffer, J Stobie, E Strom, S Watson, D Weidenschilling, S Wolf, S Young, E AF Meyer, Michael R. Hillenbrand, Lynne A. Backman, Dana Beckwith, Steve Bouwman, Jeroen Brooke, Tim Carpenter, John Cohen, Martin Cortes, Stephanie Crockett, Nathan Gorti, Uma Henning, Thomas Hines, Dean Hollenbach, David Kim, Jinyoung Serena Lunine, Jonathan Malhotra, Renu Mamajek, Eric Metchev, Stanimir Moro-Martin, Amaya Morris, Pat Najita, Joan Padgett, Deborah Pascucci, Ilaria Rodmann, Jens Schlingman, Wayne Silverstone, Murray Soderblom, David Stauffer, John Stobie, Elizabeth Strom, Steve Watson, Dan Weidenschilling, Stuart Wolf, Sebastian Young, Erick TI The formation and evolution of planetary systems: Placing our solar system in context with Spitzer SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID SUN-LIKE STARS; T-TAURI STARS; SPECTRAL ENERGY-DISTRIBUTIONS; MULTIBAND IMAGING PHOTOMETER; CIRCUMSTELLAR DEBRIS DISKS; INFRARED ARRAY CAMERA; SPACE-TELESCOPE; UPPER LIMITS; KUIPER-BELT; YOUNG STARS AB We provide an overview of the Spitzer Legacy Program, Formation and Evolution of Planetary Systems, that was proposed in 2000, begun in 2001, and executed aboard the Spitzer Space Telescope between 2003 and 2006. This program exploits the sensitivity of Spitzer to carry out mid-infrared spectrophotometric observations of solar-type stars. With a sample of similar to 328 stars ranging in age from similar to 3 Myr to similar to 3 Gyr, we trace the evolution of circumstellar gas and dust from primordial planet-building stages in young circumstellar disks through to older collisionally generated debris disks. When completed, our program will help define the timescales over which terrestrial and gas giant planets are built, constrain the frequency of planetesimal collisions as a function of time, and establish the diversity of mature planetary architectures. In addition to the observational program, we have coordinated a concomitant theoretical effort aimed at understanding the dynamics of circumstellar dust with and without the effects of embedded planets, dust spectral energy distributions, and atomic and molecular gas line emission. Together with the observations, these efforts will provide an astronomical context for understanding whether our solar system - and its habitable planet - is a common or a rare circumstance. Additional information about the FEPS project can be found on the team Web site. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Pasadena, CA 91125 USA. Stratospher Observ Infrared Astron, Mountain View, CA USA. SETI Inst, Mountain View, CA USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. NASA, Ames Res Ctr, Theory Branch, Moffett Field, CA 94035 USA. Space Sci Inst, Boulder, CO 80301 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif Los Angeles, Los Angeles, CA USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. CALTECH, Herschel Sci Ctr, IPAC, Pasadena, CA 91125 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. Planetary Sci Inst, Tucson, AZ USA. RP Meyer, MR (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA. EM mmeyer@as.arizona.edu OI Malhotra, Renu/0000-0002-1226-3305 NR 64 TC 70 Z9 70 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD DEC PY 2006 VL 118 IS 850 BP 1690 EP 1710 DI 10.1086/510099 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 127DQ UT WOS:000243565900009 ER PT J AU Yin, XC Mora, P Donnellan, A Matsu'ura, M AF Yin, Xiang-Chu Mora, Peter Donnellan, Andrea Matsu'ura, Mitsuhiro TI Computational earthquake physics - PART II: Introduction SO PURE AND APPLIED GEOPHYSICS LA English DT Editorial Material C1 Chinese Earthquake Adm, Inst Earthquake Sci, Beijing, Peoples R China. Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100080, Peoples R China. Univ Queensland, Earth Syst Sci Computat Ctr, Brisbane, Qld 4072, Australia. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Tokyo, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. RP Yin, XC (reprint author), Chinese Earthquake Adm, Inst Earthquake Sci, Beijing, Peoples R China. EM xcyin@public.bta.net.cn; director@esscc.uq.edu.au; andrea.donnellan@jpl.nasa.gov; matsuura@eps.s.u-tokyo.ac.jp NR 6 TC 0 Z9 0 U1 0 U2 0 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD DEC PY 2006 VL 163 IS 11-12 BP 2259 EP 2261 DI 10.1007/s00024-006-0138-7 PG 3 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 127ZI UT WOS:000243624700001 ER PT J AU Donnellan, A Rundle, J Fox, G McLeod, D Grant, L Tullis, T Pierce, M Parker, J Lyzenga, G Granat, R Glasscoe, M AF Donnellan, Andrea Rundle, John Fox, Geoffrey McLeod, Dennis Grant, Lisa Tullis, Terry Pierce, Marlon Parker, Jay Lyzenga, Greg Granat, Robert Glasscoe, Margaret TI QuakeSim and the Solid Earth Research Virtual Observatory SO PURE AND APPLIED GEOPHYSICS LA English DT Article; Proceedings Paper CT 4th ACES Workshop 2004 CY JUL 09-14, 2004 CL Beijing, PEOPLES R CHINA DE Earthquake; simulation; deformation; GPS; QuakeSim; web services ID THRESHOLD SYSTEMS; CALIFORNIA; DYNAMICS; FAULT; MODEL; RECOGNITION; SIMULATIONS; EARTHQUAKES; ALGORITHM AB We are developing simulation and analysis tools in order to develop a solid Earth Science framework for understanding and studying active tectonic and earthquake processes. The goal of QuakeSim and its extension, the Solid Earth Research Virtual Observatory (SERVO), is to study the physics of earthquakes using state-of-the-art modeling, data manipulation, and pattern recognition technologies. We are developing clearly defined accessible data formats and code protocols as inputs to simulations, which are adapted to high-performance computers. The solid Earth system is extremely complex and nonlinear, resulting in computationally intensive problems with millions of unknowns. With these tools it will be possible to construct the more complex models and simulations necessary to develop hazard assessment systems critical for reducing future losses from major earthquakes. We are using Web (Grid) service technology to demonstrate the assimilation of multiple distributed data sources (a typical data grid problem) into a major parallel high-performance computing earthquake forecasting code. Such a linkage of Geoinformatics with Geocomplexity demonstrates the value of the Solid Earth Research Virtual Observatory (SERVO) Grid concept, and advances Grid technology by building the first real-time large-scale data assimilation grid. C1 CALTECH, Jet Prop Lab, Div Sci, Pasadena, CA 91109 USA. Univ Calif Davis, Ctr Computat Sci & Engn, Davis, CA 95616 USA. Indiana Univ, Community Grid Comp Lab, Bloomington, IN 47404 USA. Univ So Calif, Dept Comp Sci, Los Angeles, CA 90089 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Brown Univ, Providence, RI 02912 USA. RP Donnellan, A (reprint author), CALTECH, Jet Prop Lab, Div Sci, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM donnellan@jpl.nasa.gov; rundle@geology.ucdavis.edu; gcf@indiana.edu; mcleod@usc.edu; lgrant@uci.edu; terry_tullis@brown.edu RI Ludwig, Lisa Grant/G-6442-2012; OI Ludwig, Lisa Grant/0000-0001-6538-8067; Pierce, Marlon/0000-0002-9582-5712 NR 31 TC 1 Z9 1 U1 0 U2 1 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD DEC PY 2006 VL 163 IS 11-12 BP 2263 EP 2279 DI 10.1007/s00024-006-0126-y PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 127ZI UT WOS:000243624700002 ER PT J AU Aktas, M Aydin, G Donnellan, A Fox, G Granat, R Grant, L Lyzenga, G McLeod, D Pallickara, S Parker, J Pierce, M Rundle, J Sayar, A Tullis, T AF Aktas, Mehmet Aydin, Galip Donnellan, Andrea Fox, Geoffrey Granat, Robert Grant, Lisa Lyzenga, Greg McLeod, Dennis Pallickara, Shrideep Parker, Jay Pierce, Marlon Rundle, John Sayar, Ahmet Tullis, Terry TI ISERVO: Implementing the International Solid Earth Research Virtual Observatory by integrating computational grid and geographical information Web Services SO PURE AND APPLIED GEOPHYSICS LA English DT Article; Proceedings Paper CT 4th ACES Workshop 2004 CY JUL 09-14, 2004 CL Beijing, PEOPLES R CHINA DE Web Services; computing web portals; computational grids; grid computing; earthquake simulation AB We describe the goals and initial implementation of the International Solid Earth Virtual Observatory (iSERVO). This system is built using a Web Services approach to Grid computing infrastructure and is accessed via a component-based Web portal user interface. We describe our implementations of services used by this system, including Geographical Information System (GIS)-based data grid services for accessing remote data repositories and job management services for controlling multiple execution steps. iSERVO is an example of a larger trend to build globally scalable scientific computing infrastructures using the Service Oriented Architecture approach. Adoption of this approach raises a number of research challenges in millisecond-latency message systems suitable for internet-enabled scientific applications. We review our research in these areas. C1 Indiana Univ, Dept Comp Sci, Community Grids Lab, Bloomington, IN 47404 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Indiana Univ, Dept Phys, Bloomington, IN 47404 USA. Indiana Univ, Sch Informat, Bloomington, IN 47404 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ So Calif, Los Angeles, CA 90089 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. RP Aktas, M (reprint author), Indiana Univ, Dept Comp Sci, Community Grids Lab, Bloomington, IN 47404 USA. EM Donnellan@jpl.nasa.gov; gcf@indiana.edu; Robert.Granat@jpl.nasa.gov; lgrant@uci.edu; Gregory.Lyzenga@jpl.nasa.gov; mcleod@pollux.usc.edu; jay.w.parker@jpl.nasa.gov; mpierce@cs.indiana.edu; rundle@physics.ucdavis.edu; Terry_Tullis@brown.edu RI Ludwig, Lisa Grant/G-6442-2012; OI Ludwig, Lisa Grant/0000-0001-6538-8067; Pierce, Marlon/0000-0002-9582-5712 NR 24 TC 6 Z9 6 U1 0 U2 1 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD DEC PY 2006 VL 163 IS 11-12 BP 2281 EP 2296 DI 10.1007/s00024-006-0137-8 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 127ZI UT WOS:000243624700003 ER PT J AU Holliday, JR Rundle, JB Tiampo, KF Klein, W Donnellan, A AF Holliday, J. R. Rundle, J. B. Tiampo, K. F. Klein, W. Donnellan, A. TI Systematic procedural and sensitivity analysis of the Pattern Informatics method for forecasting large (M > 5) earthquake events in Southern California SO PURE AND APPLIED GEOPHYSICS LA English DT Article; Proceedings Paper CT 4th ACES Workshop 2004 CY JUL 09-14, 2004 CL Beijing, PEOPLES R CHINA DE Pattern Informatics; earthquake forecasting ID THRESHOLD SYSTEMS; FAULT SYSTEMS; DYNAMICS; PREDICTION AB Recent studies in the literature have introduced a new approach to earthquake forecasting based on representing the space-time patterns of localized seismicity by a time-dependent system state vector in a real-valued Hilbert space and deducing information about future space-time fluctuations from the phase angle of the state vector. While the success rate of this Pattern Informatics (PI) method has been encouraging, the method is still in its infancy. Procedural analysis, statistical testing, parameter sensitivity investigation and optimization all still need to be performed. In this paper, we attempt to optimize the PI approach by developing quantitative values for "predictive goodness" and analyzing possible variations in the proposed procedure. In addition, we attempt to quantify the systematic dependence on the quality of the input catalog of historic data and develop methods for combining catalogs from regions of different seismic rates. C1 Univ Calif Davis, Ctr Computat Sci & Engn, Davis, CA 95616 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Western Ontario, Dept Earth Sci, London, ON N6A 5B7, Canada. Boston Univ, Dept Phys, Boston, MA 02215 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. RP Holliday, JR (reprint author), Univ Calif Davis, Ctr Computat Sci & Engn, 1 Shields Ave, Davis, CA 95616 USA. EM holliday@cse.ucdavis.edu; jbrundle@ucdavis.edu; ktiampo@uwo.ca; klein@buphyc.bu.edu; donnellan@jpl.nasa.gov RI Tiampo, Kristy/I-1355-2015 OI Tiampo, Kristy/0000-0002-5500-7600 NR 37 TC 12 Z9 13 U1 0 U2 0 PU SPRINGER BASEL AG PI BASEL PA PICASSOPLATZ 4, BASEL, 4052, SWITZERLAND SN 0033-4553 EI 1420-9136 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD DEC PY 2006 VL 163 IS 11-12 BP 2433 EP 2454 DI 10.1007/s00024-006-0131-1 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 127ZI UT WOS:000243624700013 ER PT J AU Granat, R AF Granat, Robert TI Detecting regional events via statistical analysis of geodetic networks SO PURE AND APPLIED GEOPHYSICS LA English DT Article; Proceedings Paper CT 4th ACES Workshop 2004 CY JUL 09-14, 2004 CL Beijing, PEOPLES R CHINA DE hidden Markov models; annealing; geodesy; segmentation ID HIDDEN MARKOV-MODELS; CONTINUOUS SPEECH RECOGNITION; CASCADIA SUBDUCTION ZONE; EM ALGORITHM; PROBABILISTIC FUNCTIONS; OPTIMIZATION; SILENT; SLOW; SLIP; EARTHQUAKES AB We present an application of hidden Markov models (HMMs) to analysis of geodetic time series in Southern California. Our model-fitting method uses a regularized version of the deterministic annealing expectation-maximization algorithm to ensure that model solutions are both robust and of high quality. Using the fitted models, we segment the daily displacement time series collected by 127 stations of the Southern California Integrated Geodetic Network (SCIGN) over a two-year period. Segmentations of the series are based on statistical changes as identified by the trained HMMs. We look for correlations in state changes across multiple stations that indicate region-wide activity. We find that although in one case a strong seismic event was associated with a spike in station correlations, in all other cases in the study, time period strong correlations were not associated with any seismic event. This indicates that the method was able to identify more subtle signals associated with aseismic events or long-range interactions between smaller events. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Granat, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM granat@jpl.nasa.gov NR 44 TC 4 Z9 4 U1 0 U2 2 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD DEC PY 2006 VL 163 IS 11-12 BP 2497 EP 2512 DI 10.1007/s00024-006-0142-y PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 127ZI UT WOS:000243624700017 ER PT J AU Svensson, A Andersen, KK Bigler, M Clausen, HB Dahl-Jensen, D Davies, SM Johnsen, SJ Muscheler, R Rasmussen, SO Rothlisberger, R Steffensen, JP Vinther, BM AF Svensson, Anders Andersen, Katr'ne K. Bigler, Matthias Clausen, Henrik B. Dahl-Jensen, Dorthe Davies, Siwan M. Johnsen, Sigfus J. Muscheler, Raimund Rasmussen, Sune O. Rothlisberger, Regine Steffensen, Jorgen Peder Vinther, Bo M. TI The Greenland Ice Core Chronology 2005, 15-42 ka. Part 2: comparison to other records SO QUATERNARY SCIENCE REVIEWS LA English DT Article ID CAL KYR BP; LAST DEGLACIATION; NORTH-ATLANTIC; C-14 RECORDS; ASH LAYERS; RADIOCARBON; CALIBRATION; AGE; EVENT; GISP2 AB A new Greenland Ice Core Chronology (GICC05) based on multi-parameter counting of annual layers has been obtained for the last 42 ka. Here we compare the glacial part of the new time scale, which is based entirely on records from the NorthGRIP ice core, to existing time scales and reference horizons covering the same period. These include the GRIP and NorthGRIP modelled time scales, the Meese-Sowers GISP2 counted time scale, the Shackleton-Fairbanks GRIP time scale (SFCP04) based on C-14 calibration of a marine core, the Hulu Cave record, three volcanic reference horizons, and the Laschamp geomagnetic excursion event occurring around Greenland Interstadial 10. GICC05 is generally in good long-term agreement with the existing Greenland ice core chronologies and with the Hulu Cave record, but on shorter time scales there are significant discrepancies. Around the Last Glacial Maximum there is a more than I ka age difference between GICC05 and SFCP04 and a more than 0.5 ka discrepancy in the same direction between GICC05 and the age of a recently identified tephra layer in the NorthGRIP ice core. Both SFCP04 and the tephra age are based on 14 C-dated marine cores and fixed marine reservoir ages. For the Laschamp event, GICC05 agrees with a recent independent dating within the uncertainties. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Univ Coll Swansea, Dept Geog, Swansea SA2 8PP, W Glam, Wales. NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. British Antarctic Survey, Cambridge CB3 0ET, England. RP Svensson, A (reprint author), Univ Copenhagen, Niels Bohr Inst, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark. EM as@gfy.ku.dk RI Rasmussen, Sune/B-5560-2008; Svensson, Anders/A-2643-2010; Davies, Siwan/E-6915-2011; Andersen, Katrine/B-4082-2016; Dahl-Jensen, Dorthe/N-4401-2016 OI Rasmussen, Sune/0000-0002-4177-3611; Svensson, Anders/0000-0002-4364-6085; Davies, Siwan/0000-0003-0999-7233; Andersen, Katrine/0000-0003-4178-2195; Dahl-Jensen, Dorthe/0000-0002-1474-1948 NR 33 TC 217 Z9 226 U1 0 U2 26 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-3791 J9 QUATERNARY SCI REV JI Quat. Sci. Rev. PD DEC PY 2006 VL 25 IS 23-24 BP 3258 EP 3267 DI 10.1016/j.quascirev.2006.08.003 PG 10 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 146FZ UT WOS:000244921200013 ER PT J AU Cherubini, R Cucinotta, FA Gerardi, S Menzel, HG O'Neill, P Ottolenghi, A AF Cherubini, R. Cucinotta, F. A. Gerardi, S. Menzel, H. G. O'Neill, P. Ottolenghi, A. TI Fourteenth international symposium on microdosimetry SO RADIATION PROTECTION DOSIMETRY LA English DT Editorial Material C1 Ist Nazl Fis Nucl, Lab Nazl Legarno, I-35020 Legnaro, Italy. NASA, Johnson Space Ctr, Houston, TX 77058 USA. CERN, CH-1211 Geneva, Switzerland. MRC, Radiat & Genome Stabil Unit, Didcot OX11 0RD, Oxon, England. RP Cherubini, R (reprint author), Ist Nazl Fis Nucl, Lab Nazl Legarno, Viale Univ 2, I-35020 Legnaro, Italy. NR 0 TC 0 Z9 0 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC PY 2006 VL 122 IS 1-4 BP 1 EP 2 PG 2 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 162YR UT WOS:000246125900001 PM 17339233 ER PT J AU Pszona, S Bantsar, A Nikjoo, H AF Pszona, S. Bantsar, A. Nikjoo, H. TI Ionization cluster size distribution for alpha particles: Experiment, modelling SO RADIATION PROTECTION DOSIMETRY LA English DT Article; Proceedings Paper CT 14th International Symposium on Microdosimetry CY NOV 13-18, 2005 CL Venezia-Isola di San Servo, ITALY SP INFN Lab Nazl Legnaro, Legnaro Padova, INFN Sezione Pavia, Univ Pavia Dipartimento Fis Nucl Teor, NASA Johnson Space Ctr, CERN, Med Res Council AB The paper presents data for measured ionization cluster size distributions by alpha particles in tissue equivalent media and comparison with the simulated data for liquid water. The experiments were carried out with a beam of 4.6 MeV alpha particles performed in a setup called the JET Counter. The theoretically derived cluster size distributions for alphas particles were obtained using the K-means algorithm. The simulation was carried out by Monte Carlo track structure calculations using cross sections for liquid water. The first moments of cluster size distributions, derived from K-means algorithm as a function of diameter of cluster centroid, were compared with the corresponding moments derived from the experiments for nitrogen and propane targets. It was found that the ratio of the first moments for water to gas targets correlates well with the corresponding ratio of the mean free paths for primary ionization by alpha particles in the two media. It is shown that the cluster size distributions for alpha particles in water, obtained from K-means algorithm, are in agreement with the corresponding distributions measured experimentally in nitrogen or propane gas targets of nanometer sizes. C1 Soltan Inst Nucl Studies, PL-05400 Otwock, Poland. NASA, Johnson Space Ctr, USRA, Houston, TX 77058 USA. RP Pszona, S (reprint author), Soltan Inst Nucl Studies, PL-05400 Otwock, Poland. EM pszona@ipj.gov.pl NR 8 TC 4 Z9 4 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC PY 2006 VL 122 IS 1-4 BP 28 EP 31 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 162YR UT WOS:000246125900006 PM 17251255 ER PT J AU Emfietzoglou, D Nikjoo, H Pathak, A AF Emfietzoglou, D. Nikjoo, H. Pathak, A. TI A comparative study of dielectric response function models for liquid water SO RADIATION PROTECTION DOSIMETRY LA English DT Article; Proceedings Paper CT 14th International Symposium on Microdosimetry CY NOV 13-18, 2005 CL Venice, ITALY SP INFN Lab Nazl Legnaro, INFN Sezione Pavia, Univ Pavia Dipartimento Fis Nucl Teor, NASA Johnson Space Ctr, CERN, Med Res Council ID X-RAY-SCATTERING; LOW-ENERGY ELECTRONS; INELASTIC-SCATTERING; CHARGED PARTICLES; CONDENSED MATTER; CROSS-SECTIONS; BETHE SURFACE; OPTICAL-DATA AB Various methodologies that aim at an analytic representation of the dielectric response function (DRF) of liquid water with emphasis on the Bethe ridge region are compared. The use of optical data is a common feature to all models presented providing an empirical ground for modelling the valence energy losses where many-body (and phase) effects are expected to be most prevalent. The dispersion models used for describing the momentum dependence of the DRF are evaluated against the recent inelastic X-ray scattering (IXS) spectroscopy data. Recent developments along the tines of Ritchie's extended-Drude scheme for an improved representation of the experimental Bethe ridge are presented. C1 Univ Ioannina, Sch Med, Med Phys Lab, GR-45110 Ioannina, Greece. NASA, Johnson Space Ctr, USRA, Houston, TX 77058 USA. Univ Hyderabad, Sch Phys, Hyderabad 500046, Andhra Pradesh, India. RP Emfietzoglou, D (reprint author), Univ Ioannina, Sch Med, Med Phys Lab, GR-45110 Ioannina, Greece. EM demfietz@cc.uoi.gr RI Emfietzoglou, Dimitris/G-7168-2012 NR 20 TC 3 Z9 3 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC PY 2006 VL 122 IS 1-4 BP 61 EP 65 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 162YR UT WOS:000246125900013 PM 17251250 ER PT J AU Nikjoo, H Girard, P Charlton, DE Hofer, KG Laughton, CA AF Nikjoo, H. Girard, P. Charlton, D. E. Hofer, K. G. Laughton, C. A. TI Auger electrons - A nanoprobe for structural, molecular and cellular processes SO RADIATION PROTECTION DOSIMETRY LA English DT Article; Proceedings Paper CT 14th International Symposium on Microdosimetry CY NOV 13-18, 2005 CL Venezia-Isola di San Servo, ITALY SP INFN Lab Nazl Legnaro, Legnaro Padova, INFN Sezione Pavia, Univ Pavia Dipartimento Fis Nucl Teor, NASA Johnson Space Ctr, CERN, Med Res Council ID FORMING OLIGONUCLEOTIDES; BIOPHYSICAL ASPECTS; HUMAN-CELLS; DNA-DAMAGE; I-125; DECAY; BREAKAGE AB This paper provides a brief review of recently published work on biophysical and biological aspects of Auger processes. Three specific questions have been considered. (1) Does charge neutralisation contribute to molecular damage such as DNA strand breaks? (2) How many DNA double strand breaks are produced by a single decay of DNA bound I-125? (3) What is the correlation between number of gamma H2AX foci and number of double strand breaks (DSB)? The paper also gives preliminary reports on two new calculations: (a) calculation of the spectrum of Auger electrons released during decay of 1241 and (b) the use of Auger electrons in the decay of I-125 as a probing agent of novel DNA structures. C1 NASA, Johnson Space Ctr, USRA, Houston, TX 77058 USA. Univ Nottingham, Sch Pharm, Nottingham NG7 2RD, England. Concordia Univ, Dept Phys, Montreal, PQ H3G 1M8, Canada. Florida State Univ, Dept Biol Sci, Tallahassee, FL 32306 USA. RP Nikjoo, H (reprint author), NASA, Johnson Space Ctr, USRA, Houston, TX 77058 USA. EM Hooshang.nikjoo@jsc.nasa.gov RI Laughton, Charles/E-5667-2010 OI Laughton, Charles/0000-0003-4090-3960 NR 29 TC 11 Z9 11 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC PY 2006 VL 122 IS 1-4 BP 72 EP 79 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 162YR UT WOS:000246125900015 PM 17132671 ER PT J AU Schimmerling, W Cucinotta, FA AF Schimmerling, W. Cucinotta, F. A. TI Dose and dose rate effectiveness of space radiation SO RADIATION PROTECTION DOSIMETRY LA English DT Article; Proceedings Paper CT 14th International Symposium on Microdosimetry CY NOV 13-18, 2005 CL Venezia-Isola di San Servo, ITALY SP INFN Lab Nazl Legnaro, Legnaro Padova, INFN Sezione Pavia, Univ Pavia Dipartimento Fis Nucl Teor, NASA Johnson Space Ctr, CERN, Med Res Council ID CARCINOGENESIS AB Dose and dose rate effectiveness factors (DDREF), in conjunction with other weighting factors, are commonly used to scale atomic bomb survivor data in order to establish limits for occupational radiation exposure, including radiation exposure in space. We use some well-known facts about the microscopic pattern of energy deposition of high-energy heavy ions, and about the dose rate dependence of chemical reactions initiated by radiation, to show that DDREF are likely to vary significantly as a function of particle type and energy, cell, tissue, and organ type, and biological end point. As a consequence, we argue that validation of DDREF by conventional methods, e.g. irradiating animal colonies and compiling statistics of cancer mortality, is not appropriate. However, the use of approaches derived from information theory and thermodynamics is a very wide field, and the present work can only be understood as a contribution to an ongoing discussion. C1 NASA, Headquarters, Washington, DC 20546 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Schimmerling, W (reprint author), NASA, Headquarters, Washington, DC 20546 USA. EM walter2205@mac.com NR 14 TC 12 Z9 13 U1 0 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC PY 2006 VL 122 IS 1-4 BP 349 EP 353 DI 10.1093/rpd/ncl464 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 162YR UT WOS:000246125900074 PM 17169950 ER PT J AU Ponomarev, AL Cucinotta, FA AF Ponomarev, A. L. Cucinotta, F. A. TI Nuclear fragmentation and the number of particle tracks in tissue SO RADIATION PROTECTION DOSIMETRY LA English DT Article; Proceedings Paper CT 14th International Symposium on Microdosimetry CY NOV 13-18, 2005 CL Venezia-Isola di San Servo, ITALY SP INFN Lab Nazl Legnaro, Legnaro Padova, INFN Sezione Pavia, Univ Pavia Dipartimento Fis Nucl Teor, NASA Johnson Space Ctr, CERN, Med Res Council ID RISKS; RAYS AB For high energy nuclei, the number of particle tracks per cell is modified by local nuclear reactions that occur, with large fluctuations expected for heavy ion tracks. Cells near the interaction site of a reaction will experience a much higher number of tracks than estimated by the average fluence. Two types of reaction products are possible and occur in coincidence; projectile fragments, which generally have smaller charge and similar velocity to that of the projectile, and target fragments, which are produced from the fragmentation of the nuclei of water atoms or other cellular constituents with low velocity. In order to understand the role of fragmentation in biological damage a new model of human tissue irradiated by heavy ions was developed. A box of the tissue is modelled with periodic boundary conditions imposed, which extrapolates the technique to macroscopic volumes of tissue. The cross sections for projectile and target fragmentation products are taken from the quantum multiple scattering fragmentation code previously developed at NASA Johnson Space Center. Statistics of fragmentation pathways occurring in a cell monolayer, as well as in a small volume of 10 x 10 x 10 cells are given. A discussion on approaches to extend the model to describe spatial distributions of inactivated or other cell damage types, as well as highly organised tissues of multiple cell types, is presented. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. USRA, Div & Life Space Sci, Houston, TX 77058 USA. RP Ponomarev, AL (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM aponomar@ems.jsc.nasa.gov NR 11 TC 5 Z9 5 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0144-8420 J9 RADIAT PROT DOSIM JI Radiat. Prot. Dosim. PD DEC PY 2006 VL 122 IS 1-4 BP 354 EP 361 DI 10.1093/rpd/ncl465 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 162YR UT WOS:000246125900075 PM 17261538 ER PT J AU Ponomarev, AL Belli, M Hahnfeldt, PJ Hlatky, L Sachs, RK Cucinotta, FA AF Ponomarev, Artem L. Belli, Mauro Hahnfeldt, Philip J. Hlatky, Lynn Sachs, Rainer K. Cucinotta, Francis A. TI A robust procedure for removing background damage in assays of radiation-induced DNA fragment distributions SO RADIATION RESEARCH LA English DT Article ID DOUBLE-STRAND BREAKS; FIELD GEL-ELECTROPHORESIS; LINEAR-ENERGY-TRANSFER; IONIZING-RADIATION; V79 CELLS; SIZE-DISTRIBUTION; HUMAN FIBROBLASTS; MAMMALIAN-CELLS; LIGHT-IONS; MODEL AB The non-random distribution of DNA breakage in PFGE (pulsed-field gel electrophoresis) experiments poses a problem of proper subtraction of the background DNA damage to obtain a fragment-size distribution due to radiation only. A naive bin-to-bin subtraction of the background signal will not result in the right DNA mass distribution histogram. This problem could become more pronounced for high-LET (linear energy transfer) radiation, because the fragment-size distribution manifests a higher frequency of smaller fragments. Previous systematic subtraction methods have been based on random breakage, appropriate for low-LET radiation. Moreover, an investigation is needed to determine whether the background breakage is itself random or non-random. We consider two limiting cases: (1) the background damage is present in all cells, and (2) it is present in only a small subset of cells, while other cells are not contributing to the background DNA fragmentation. We give a generalized formalism based on stochastic processes for the subtraction of the background damage in PFGE experiments for any LET and apply it to two sets of PFGE data for iron ions. (c) 2006 by Radiation Research Society. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. USRA, Houston, TX 77058 USA. Ist Super Sanita, Technol & Hlth Dept, I-00161 Rome, Italy. Tufts Univ, Sch Med, Ctr Canc Syst Biol, St Elizabeths Med Ctr, Boston, MA 02135 USA. Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Ponomarev, AL (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code SK211,Bldg 37,Room 119, Houston, TX 77058 USA. EM aponomar@ems.jsc.nasa.gov FU NIGMS NIH HHS [GM68423] NR 29 TC 6 Z9 6 U1 0 U2 2 PU RADIATION RESEARCH SOC PI LAWRENCE PA 810 E TENTH STREET, LAWRENCE, KS 66044 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD DEC PY 2006 VL 166 IS 6 BP 908 EP 916 DI 10.1667/RR0663.1 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 116ZP UT WOS:000242842600011 PM 17149980 ER PT J AU Li, J Lu, Y Meyyappan, M AF Li, Jing Lu, Y. Meyyappan, M. TI Carbon nanotube based chemical sensors SO RARE METAL MATERIALS AND ENGINEERING LA English DT Article; Proceedings Paper CT 6th East Asian Conference on Chemical Sensors (EACCS-6) CY NOV 06-09, 2005 CL Guillin, PEOPLES R CHINA SP Minist Educ China, Natl Nat Sci Fdn China, Tsinghua Univ C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Meyyappan, M (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Mailstop 229-3, Moffett Field, CA 94035 USA. EM meyya@orbit.arc.nasa.gov NR 0 TC 1 Z9 1 U1 2 U2 2 PU NORTHWEST INST NONFERROUS METAL RESEARCH PI SHAANXI PA C/O RARE METAL MATERIAL ENGINEERING PRESS, PO BOX 51, XIAN, SHAANXI 710016, PEOPLES R CHINA SN 1002-185X J9 RARE METAL MAT ENG JI Rare Metal Mat. Eng. PD DEC PY 2006 VL 35 SU 3 BP 7 EP 8 PG 2 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 139UB UT WOS:000244457000004 ER PT J AU Nakamura-Messenger, K Messenger, S Keller, LP Clemett, SJ Zolensky, ME AF Nakamura-Messenger, Keiko Messenger, Scott Keller, Lindsay P. Clemett, Simon J. Zolensky, Michael E. TI Organic globules in the Tagish Lake meteorite: Remnants of the protosolar disk SO SCIENCE LA English DT Article ID DENSE INTERSTELLAR CLOUDS; INTERPLANETARY DUST; DEUTERIUM FRACTIONATION; CARBONACEOUS CHONDRITES; NITROGEN; MATTER; ABUNDANCES; CHEMISTRY; ICE AB Coordinated transmission electron microscopy and isotopic measurements of organic globules in the Tagish Lake meteorite shows that they have elevated ratios of nitrogen-15 to nitrogen-14 (1.2 to 2 times terrestrial) and of deuterium to hydrogen (2.5 to 9 times terrestrial). These isotopic anomalies are indicative of mass fractionation during chemical reactions at extremely low temperatures ( 10 to 20 kelvin), characteristic of cold molecular clouds and the outer protosolar disk. The globules probably originated as organic ice coatings on preexisting grains that were photochemically processed into refractory organic matter. The globules resemble cometary carbon, hydrogen, oxygen, and nitrogen (CHON) particles, suggesting that such grains were important constituents of the solar system starting materials. C1 NASA, Lyndon B Johnson Space Ctr, Robert M Walker Lab Space Sci, Astromat Res & Explorat Sci Directorate, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, ESC Grp Jacobs Sverdrup, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, ESC Grp ERC Inc, Houston, TX 77058 USA. RP Nakamura-Messenger, K (reprint author), NASA, Lyndon B Johnson Space Ctr, Robert M Walker Lab Space Sci, Astromat Res & Explorat Sci Directorate, Houston, TX 77058 USA. EM keiko.nakamura-1@nasa.gov NR 29 TC 128 Z9 129 U1 2 U2 11 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 1 PY 2006 VL 314 IS 5804 BP 1439 EP 1442 DI 10.1126/science.1132175 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 110UF UT WOS:000242406100037 PM 17138898 ER PT J AU Xu, JH Wu, NQ Jiang, CB Zhao, MH Li, J Wei, YG Mao, SX AF Xu, Jianhui Wu, Nianqiang Jiang, Chuanbin Zhao, Minhua Li, Jing Wei, Yueguang Mao, Scott X. TI Impedance characterization of ZnO nanobett/Pd Schottky contacts in ammonia SO SMALL LA English DT Article DE chemical sensors; nanobelts; nanowires; Schottky contacts; zinc oxide ID ROOM-TEMPERATURE; IN2O3 NANOWIRES; SENSORS; SURFACE; OXIDE; NANOCRYSTALS; NANOBELT; GROWTH; CO C1 W Virginia Univ, Dept Mech & Aerosp Engn, Morgantown, WV 26506 USA. Univ Pittsburgh, Dept Mech Engn, Pittsburgh, PA 15261 USA. Inst Met Sci & Technol, Shenyang 110016, Peoples R China. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Inst Mech, Beijing, Peoples R China. RP Wu, NQ (reprint author), W Virginia Univ, Dept Mech & Aerosp Engn, Morgantown, WV 26506 USA. EM nick.wu@mail.wvu.edu; smao@engr.pitt.edu RI Zhao, Minhua/A-6678-2009; Wu, Nianqiang/B-9798-2015 OI Zhao, Minhua/0000-0003-4880-1010; Wu, Nianqiang/0000-0002-8888-2444 NR 21 TC 16 Z9 16 U1 2 U2 11 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1613-6810 J9 SMALL JI Small PD DEC PY 2006 VL 2 IS 12 BP 1458 EP 1461 DI 10.1002/smll.200600309 PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 108YT UT WOS:000242275800013 PM 17193006 ER PT J AU Mossi, K Mouhli, M Smith, BF Mane, PP Bryant, RG AF Mossi, K. Mouhli, M. Smith, B. F. Mane, P. P. Bryant, R. G. TI Shape modeling and validation of stress-biased piezoelectric actuators SO SMART MATERIALS & STRUCTURES LA English DT Article ID ROOM-TEMPERATURE SHAPES; STRAIN SOLID ELEMENT; PIEZOCERAMIC ACTUATORS; RAINBOW ACTUATORS; DESIGN; BEAM; DISPLACEMENT; UNIMORPHS; SENSORS; PLATES AB Piezoelectric composites with a characteristic initial curvature and accompanying residual stresses are capable of enhanced performance, relative to flat actuators. This paper utilizes Rayleigh-Ritz techniques with revisions regarding the effective in-plane resultant force and the effective bending moment. The Rayleigh-Ritz technique is based on the assumption that the stable geometric configuration developed in the actuator after manufacturing is the configuration that minimizes the total potential energy. This energy is a function of the displacement field which can be approximated by either a four-term model or a 23-term model. In this case, Thunder((R)), a composite of steel, polyimide adhesive, PZT, and aluminum is constructed with varying geometries so that three-dimensional surface topology maps are measured. Numerically, the four-coefficient model produces results that are not comparable to experimental data. The 23-coefficient model generally shows good agreement with the data for all studied actuators. In the case of actuators with a length to width ratio of one, simulations are close to experimental results. In the case of length to width ratios different to unity, the model accurately predicts the devices' shape. It is further demonstrated that the curvature of the devices seems to follow the rolling direction of the stainless steel layer, challenging the isotropy assumption. C1 Virginia Commonwealth Univ, Richmond, VA 23284 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Mossi, K (reprint author), Virginia Commonwealth Univ, 601 W Main St,Box 843015, Richmond, VA 23284 USA. EM kmmossi@vcu.edu NR 46 TC 10 Z9 12 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 2006 VL 15 IS 6 BP 1785 EP 1793 DI 10.1088/0964-1726/15/6/033 PG 9 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 113LD UT WOS:000242598500033 ER PT J AU Harlan, SL Brazel, AJ Prashad, L Stefanov, WL Larsen, L AF Harlan, Sharon L. Brazel, Anthony J. Prashad, Lela Stefanov, William L. Larsen, Larissa TI Neighborhood microclimates and vulnerability to heat stress SO SOCIAL SCIENCE & MEDICINE LA English DT Article DE USA; health inequalities; climate; neighborhood environment; environmental justice ID UNITED-STATES; CLIMATE-CHANGE; US CITIES; MORTALITY; TEMPERATURE; HEALTH; IMPACTS; WEATHER; MITIGATION; ISLANDS AB Human exposure to excessively warm weather, especially in cities, is an increasingly important public health problem. This study examined heat-related health inequalities within one city in order to understand the relationships between the microclimates of urban neighborhoods, population characteristics, thermal environments that regulate microclimates, and the resources people possess to cope with climatic conditions. A simulation model was used to estimate an outdoor human thermal comfort index (HTCI) as a function of local climate variables collected in 8 diverse city neighborhoods during the summer of 2003 in Phoenix, USA. HTCI is an indicator of heat stress, a condition that can cause illness and death. There were statistically significant differences in temperatures and HTCI between the neighborhoods during the entire summer, which increased during a heat wave period. Lower socioeconomic and ethnic minority groups were more likely to live in warmer neighborhoods with greater exposure to heat stress. High settlement density, sparse vegetation, and having no open space in the neighborhood were significantly correlated with higher temperatures and HTCI. People in warmer neighborhoods were more vulnerable to heat exposure because they had fewer social and material resources to cope with extreme heat. Urban heat island reduction policies should specifically target vulnerable residential areas and take into account equitable distribution and preservation of environmental resources. (c) 2006 Elsevier Ltd. All rights reserved. C1 Arizona State Univ, Tempe, AZ 85287 USA. NASA, Lyndon B Johnson Space Ctr, Image Sci & Anal Lab, Houston, TX 77058 USA. Univ Michigan, Ann Arbor, MI 48109 USA. RP Harlan, SL (reprint author), Arizona State Univ, Tempe, AZ 85287 USA. EM sharon.harlan@asu.edu; abrazel@asu.edu; lela.prashad@asu.edu; william.l.stefanov@nasa.gov; larissal@umich.edu NR 67 TC 265 Z9 277 U1 15 U2 152 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-9536 J9 SOC SCI MED JI Soc. Sci. Med. PD DEC PY 2006 VL 63 IS 11 BP 2847 EP 2863 DI 10.1016/j.socscimed.2006.07.030 PG 17 WC Public, Environmental & Occupational Health; Social Sciences, Biomedical SC Public, Environmental & Occupational Health; Biomedical Social Sciences GA 112HG UT WOS:000242515900009 PM 16996668 ER PT J AU Wu, CC Lepping, RP Gopalswamy, N AF Wu, C. C. Lepping, R. P. Gopalswamy, N. TI Relationships among magnetic clouds, CMEs, and geomagnetic storms SO SOLAR PHYSICS LA English DT Article ID 1 AU; IDENTIFICATION; SOLAR-CYCLE-23; HELIOS; WIND AB During solar cycle 23, 82 interplanetary magnetic clouds (MCs) were identified by the Magnetic Field Investigation (MFI) team using Wind (1995-2003)solar wind plasma and magnetic field data from solar minimum through the maximum of cycle 23. The average occurrence rate is 9.5 MCs per year for the overall period. It is found that some of the anomalies in the frequency of occurrence were during the early part of solar cycle 23: (i) only four MCs were observed in 1999, and (ii) an unusually large number of MCs (17 events) were observed in 1997, just after solar minimum. We also discuss the relationship between MCs, coronal mass ejections (CMEs), and geomagnetic storms. During the period 1996-2003, almost 8000 CMEs were observed by SOHO-LASCO. The occurrence frequency of MCs appears to be related neither to the occurrence of CMEs as observed by SOHO LASCO nor to the sunspot number. When we included "magnetic cloud-like structures" (MCLs, defined by Lepping, Wu, and Berdichevsky, 2005), we found that the occurrence of the joint set (MCs+MCLs) is correlated with both sunspot number and the occurrence rate of CMEs. The average duration of the MCL structures is similar to 40% shorter than that of the MCs. The MCs are typically more geoeffective than the MCLs, because the average southward field component is generally stronger and longer lasting in MCs than in MCLs. In addition, most severe storms caused by MCs/MCLs with Dst(min) <=-100 nT occurred in the active solar period. C1 Univ Alabama, CSPAR, Huntsville, AL 35899 USA. NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Greenbelt, MD 20771 USA. Chinese Acad Sci, Lab Space Weather, Beijing, Peoples R China. NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP Wu, CC (reprint author), Univ Alabama, CSPAR, Huntsville, AL 35899 USA. EM wuc@cspar.uah.edu RI Gopalswamy, Nat/D-3659-2012 NR 16 TC 30 Z9 32 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 2006 VL 239 IS 1-2 BP 449 EP 460 DI 10.1007/s11207-006-0037-1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 115AJ UT WOS:000242706500020 ER PT J AU DellaCorte, C AF DellaCorte, Christopher TI Winter's tribology challenges SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH USA. RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. EM cdellacorte@stle.org NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1545-858X J9 TRIBOL LUBR TECHNOL JI Tribol. Lubr. Technol. PD DEC PY 2006 VL 62 IS 12 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 121SR UT WOS:000243177800002 ER PT J AU Alouini, MS Simon, MK AF Alouini, Mohamed-Slim Simon, Marvin K. TI Performance of generalized selection combining over Weibull fading channels SO WIRELESS COMMUNICATIONS & MOBILE COMPUTING LA English DT Article DE fading channel; diversity techniques; selection combining; performance analysis ID DIVERSITY RECEIVERS; RATIO AB The literature is relatively sparse in performance analysis of diversity combining schemes over Weibull fading channels, despite the fact that the Weibull distribution is often found to be suitably fit for empirical fading channel measurements. In this paper, we capitalize on some interesting results due to Lieblein on the order statistics of Weibull random variables to derive exact closed-form expressions for the combined average signal-to-noise ratio (SNR) as well as amount of fading (AF) at a generalized selection combining (GSC) output over Weibull fading channels. We also use some simple AF-based mappings between the fading parameters of the Weibull distribution and those of the Nakagami, Rice, and Hoyt distributions to obtain the approximate but accurate average SNR and AF of GSC over these types of channels. The mathematical equations are validated and illustrated by some numerical examples for scenarios of practical interest. Copyright (C) 2006 John Wiley & Sons, Ltd. C1 Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Alouini, MS (reprint author), Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. EM alouini@ece.umn.edu NR 17 TC 4 Z9 4 U1 1 U2 3 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1530-8669 J9 WIREL COMMUN MOB COM JI Wirel. Commun. Mob. Comput. PD DEC PY 2006 VL 6 IS 8 BP 1077 EP 1084 DI 10.1002/wcm.294 PG 8 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 119CD UT WOS:000242988900004 ER PT J AU Creasey, JE Forbes, JM Keating, GM AF Creasey, John E. Forbes, Jeffrey M. Keating, Gerald M. TI Density variability at scales typical of gravity waves observed in Mars' thermosphere by the MGS accelerometer SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GENERAL-CIRCULATION MODELS; MARTIAN UPPER-ATMOSPHERE; SHUTTLE REENTRY DATA; GLOBAL SURVEYOR; MIDDLE ATMOSPHERE; VENUS; AEROBRAKING; TIDES; TES AB Examination of the small-scale density perturbations in Mars' thermosphere inferred from Mars Global Surveyor (MGS) accelerometer data reveals wave-like structures consistent with gravity waves. The structures are interpreted to be horizontal with dominant wavelengths of 100 - 300 km observed along the orbital path. Density perturbations are significantly stronger in winter versus spring/summer, suggesting that the zonal mean winds play a major role in filtering these waves. There is also evidence of possible modulation by the mean winds due to local time differences. No correlation is found with the underlying topography, a source region on Earth for gravity waves. In fact, density perturbations in the northern hemisphere are observed to be greater than those in the southern hemisphere, which has a higher orographic variance. Over the Martian tropics, an observed source region for gravity waves, density perturbations are again not elevated, leaving questions on how gravity waves observed in the lower atmosphere are related to those observed in the thermosphere. C1 Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA. George Washington Univ, NASA, Langley Res Ctr, Joint Inst Adv Flight Sci, Hampton, VA 23681 USA. RP Creasey, JE (reprint author), Univ Colorado, Dept Aerosp Engn Sci, Campus Box 429, Boulder, CO 80309 USA. EM john.creasey@colorado.edu; forbes@colorado.edu; g.m.keating@larc.nasa.gov OI FORBES, JEFFREY/0000-0001-6937-0796 NR 24 TC 23 Z9 23 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 30 PY 2006 VL 33 IS 22 AR L22814 DI 10.1029/2006GL027583 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 115MS UT WOS:000242739000003 ER PT J AU Bozzolo, G Mosca, HO Noebe, RD AF Bozzolo, Guillermo Mosca, Hugo O. Noebe, Ronald D. TI Site preference of ternary alloying additions to AuTi SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE computer simulations; gold; titanium; shape memory; semi-empirical methods ID SHAPE-MEMORY ALLOYS; MARTENSITIC TRANSFORMATIONS; AL; FE AB Atomistic modeling of the site substitution behavior of several alloying additions, namely, Na, Mg, Al, Si, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb. Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, and Pt in B2 TiAu is reported. The 30 elements can be grouped according to their absolute preference for a specific site, regardless of concentration, or preference for available sites in the deficient sublattice. Results of large scale simulations are also presented, distinguishing between additions that remain in solution from those that precipitate a second phase. (c) 2006 Elsevier B.V. All rights reserved. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. UAM, Comis Nacl Energia Atom, San Martin, Argentina. RP Bozzolo, G (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. EM guille_bozzolo@yahoo.com NR 20 TC 6 Z9 6 U1 2 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD NOV 30 PY 2006 VL 425 IS 1-2 BP 239 EP 244 DI 10.1016/j.jallcom.2006.04.022 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 114BK UT WOS:000242641500042 ER PT J AU Hall, FG de Colstoun, EB Collatz, GJ Landis, D Dirmeyer, P Betts, A Huffman, GJ Bounoua, L Meeson, B AF Hall, Forrest G. de Colstoun, Eric Brown Collatz, George J. Landis, David Dirmeyer, Paul Betts, Alan Huffman, George J. Bounoua, Lahouari Meeson, Blanche TI ISLSCP Initiative II global data sets: Surface boundary conditions and atmospheric forcings for land-atmosphere studies SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SPACE-TIME CLIMATE; PARAMETERIZATION SIB2; AVHRR DATA; SPATIAL-RESOLUTION; HILBERT SPECTRUM; BIOSPHERE MODEL; SATELLITE DATA; CARBON-CYCLE; NCEP-NCAR; ALBEDO AB [1] We report herein the publication and evaluation of the International Satellite Land Surface Climatology Project (ISLSCP) Initiative II global interdisciplinary data record. The record consists of 52 data sets, with a common series in the 10-year period 1985 to 1996. Selected data series extend well beyond this period. All series are coregistered to a common grid and gap-filled for continuity using uniform procedures. We describe briefly the individual data sets within the collection; provide user guidance; and contrast, compare and evaluate those data sets containing similar parameters (land cover, NDVI, albedo, precipitation and near-surface meteorology). We also describe the process used to develop the Initiative II collection which involved a broad international scientific community focused on addressing a well-defined set of carbon, water and energy cycle questions within the context of a specific set of analysis tools. The communities that drove the definition of the Initiative II collection were investigators within the international scientific communities of the Global Energy and Water cycle Experiment, GEWEX, program (http://www.gewex.org/); the International Geosphere/Biosphere Program IGBP (http://www.igbp.kva.se); and the U.S. Global Change Research Program, USGCRP (http://www.usgcrp.gov/). Finally, we report usage statistics based on access and download of files from the ISLSCP Initiative II collection available at http://www.daac.ornl.gov. C1 Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. Ctr Ocean Land Atmosphere Studies, Calverton, MD USA. Atmospher Res, Pittsford, VT USA. Ocean US, Arlington, VA USA. RP Hall, FG (reprint author), Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. EM fghall@ltpmail.gsfc.nasa.gov; ericbdc@ltpmail.gsfc.nasa.gov; jcollatz@ltpmail.gsfc.nasa.gov; dirmeyer@cola.iges.org; akbetts@aol.com; huffman@agnes.gsfc.nasa.gov; bounoua@ltpmail.gsfc.nasa.gov RI collatz, george/D-5381-2012; Huffman, George/F-4494-2014; Dirmeyer, Paul/B-6553-2016 OI Huffman, George/0000-0003-3858-8308; Dirmeyer, Paul/0000-0003-3158-1752 NR 72 TC 36 Z9 37 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 30 PY 2006 VL 111 IS D22 AR D22S01 DI 10.1029/2006JD007366 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 115NL UT WOS:000242740900004 ER PT J AU Nassar, R Bernath, PF Boone, CD McLeod, SD Skelton, R Walker, KA Rinsland, CP Duchatelet, P AF Nassar, R. Bernath, P. F. Boone, C. D. McLeod, S. D. Skelton, R. Walker, K. A. Rinsland, C. P. Duchatelet, P. TI A global inventory of stratospheric fluorine in 2004 based on Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; CROSS-SECTIONS; CHLORINE; HYDROHALOCARBONS; LIFETIMES; BUDGET; MODEL AB [1] Total fluorine (F-TOT) in the stratosphere has been determined using Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) measurements of HF, COF2, COClF, CF4, CCl3F (CFC-11), CCl2F2 (CFC-12), CHClF2 (HCFC-22), CCl2FCClF2 (CFC-113), CH3CClF2 (HCFC-142b), CH2FCF3 (HFC-134a), and SF6. The retrieval of HFC-134a (CH2FCF3) from spaceborne measurements had not been carried out prior to this work. Measurements of these species have been supplemented by data from models to extend the altitude range of the profiles and have also been complemented by estimates of 15 minor fluorine species. Using these data, separate fluorine budgets were determined in five latitude zones (60 degrees - 82 degrees N, 30 degrees - 60 degrees N, 30 degrees S - 30 degrees N, 30 degrees - 60 degrees S, and 60 degrees - 82 degrees S) by averaging over the period of February 2004 to January 2005 inclusive, when possible. Stratospheric FTOT profiles in each latitude zone are nearly linear, with mean stratospheric FTOT values ranging from 2.50 to 2.59 ppbv (with a 1 sigma precision of 0.04 - 0.07 ppbv and an estimated accuracy of 0.15 ppbv) for each zone. The highest mean F-TOT value occurred in the tropics, which is qualitatively consistent with increasing levels of stratospheric fluorine and the mean stratospheric circulation pattern. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Univ Liege, Inst Astrophys & Geophys, Liege, Belgium. RP Nassar, R (reprint author), Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. EM ray@io.as.harvard.edu RI Bernath, Peter/B-6567-2012; OI Bernath, Peter/0000-0002-1255-396X; Nassar, Ray/0000-0001-6282-1611 NR 33 TC 16 Z9 16 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 30 PY 2006 VL 111 IS D22 AR D22313 DI 10.1029/2006JD007395 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 115NL UT WOS:000242740900005 ER PT J AU Nassar, R Bernath, PF Boone, CD Clerbaux, C Coheur, PF Dufour, G Froidevaux, L Mahieu, E McConnell, JC McLeod, SD Murtagh, DP Rinsland, CP Semeniuk, K Skelton, R Walker, KA Zander, R AF Nassar, R. Bernath, P. F. Boone, C. D. Clerbaux, C. Coheur, P. F. Dufour, G. Froidevaux, L. Mahieu, E. McConnell, J. C. McLeod, S. D. Murtagh, D. P. Rinsland, C. P. Semeniuk, K. Skelton, R. Walker, K. A. Zander, R. TI A global inventory of stratospheric chlorine in 2004 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; OZONE DEPLETION; SELF-REACTION; BUDGET; VALIDATION; SATELLITE; CLO; CONFIRMATION; TEMPERATURE; HALOCARBONS AB [1] Total chlorine (Cl-TOT) in the stratosphere has been determined using the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) measurements of HCl, ClONO2, CH3Cl, CCl4, CCl3F (CFC-11), CCl2F2 (CFC-12), CHClF2 (HCFC-22), CCl2FCClF2 (CFC-113), CH3CClF2 (HCFC-142b), COClF, and ClO supplemented by data from several other sources, including both measurements and models. Separate chlorine inventories were carried out in five latitude zones (60 degrees - 82 degrees N, 30 degrees - 60 degrees N, 30 degrees S - 30 degrees N, 30 degrees - 60 degrees S, and 60 degrees - 82 degrees S), averaging the period of February 2004 to January 2005 inclusive, when possible, to deal with seasonal variations. The effect of diurnal variation was avoided by only using measurements taken at local sunset. Mean stratospheric Cl-TOT values of 3.65 ppbv were determined for both the northern and southern midlatitudes (with an estimated 1 sigma accuracy of +/- 0.13 ppbv and a precision of +/- 0.09 ppbv), accompanied by a slightly lower value in the tropics and slightly higher values at high latitudes. Stratospheric Cl-TOT profiles in all five latitude zones are nearly linear with a slight positive slope in ppbv/km. Both the observed slopes and pattern of latitudinal variation can be interpreted as evidence of the beginning of a decline in global stratospheric chlorine, which is qualitatively consistent with the mean stratospheric circulation pattern and time lag necessary for transport. C1 Univ Paris 06, Inst Pierre Simon Laplace, Serv Aeronomie, Paris, France. Univ Libre Bruxelles, Serv Chim Quant & Photophys, Brussels, Belgium. Inst Pierre Simon Laplace, Ecole Polytech, Lab Meteorol Dynam, Palaiseau, France. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. Univ Liege, Inst Astrophys & Geophys, Liege, Belgium. Univ York, Dept Earth & Space Sci & Engn, Toronto, ON, Canada. Chalmers, Dept Radio & Space Sci, S-41296 Gothenburg, Sweden. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. RP Nassar, R (reprint author), Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. EM ray@io.as.harvard.edu RI Bernath, Peter/B-6567-2012; Murtagh, Donal/F-8694-2011; clerbaux, cathy/I-5478-2013; OI Bernath, Peter/0000-0002-1255-396X; Murtagh, Donal/0000-0003-1539-3559; Nassar, Ray/0000-0001-6282-1611; Mahieu, Emmanuel/0000-0002-5251-0286 NR 55 TC 33 Z9 33 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 30 PY 2006 VL 111 IS D22 AR D22312 DI 10.1029/2006JD007073 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 115NL UT WOS:000242740900002 ER PT J AU Israel, G Szopa, C Raulin, F Cabane, M Niemann, HB Atreya, SK Bauer, SJ Brun, JF Chassefiere, E Coll, P Conde, E Coscia, D Hauchecorne, A Millian, P Nguyen, MJ Owen, T Riedler, W Samuelson, RE Siguier, JM Steller, M Sternberg, R Vidal-Madjar, C AF Israel, G. Szopa, C. Raulin, F. Cabane, M. Niemann, H. B. Atreya, S. K. Bauer, S. J. Brun, J. -F. Chassefiere, E. Coll, P. Conde, E. Coscia, D. Hauchecorne, A. Millian, P. Nguyen, M. J. Owen, T. Riedler, W. Samuelson, R. E. Siguier, J. -M. Steller, M. Sternberg, R. Vidal-Madjar, C. TI Complex organic matter in Titan's aerosols? Reply SO NATURE LA English DT Letter ID THOLINS; ATMOSPHERE C1 Univ Paris 06, ISPL, Serv Aeron, CNRS,UMR 7620, F-91371 Verrieres Le Buisson, France. Univ Versailles, ISPL, Serv Aeron, CNRS,UMR 7620, F-91371 Verrieres Le Buisson, France. Univ Paris 12, Lab Interuniv Syst Atmospher, CNRS, UMR 7583, F-94010 Creteil, France. Univ Paris 07, Lab Interuniv Syst Atmospher, CNRS, UMR 7583, F-94010 Creteil, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Graz Univ, Inst Meteorol & Geophys, A-8010 Graz, Austria. Ctr Natl Etud Spatiales, F-31401 Toulouse, France. Off Natl Etud & Rech Aerosp, F-31055 Toulouse, France. Univ Hawaii Manoa, Inst Astron, Honolulu, HI 96822 USA. Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Austrian Acad Sci, Inst Weltraumforsch, A-8042 Graz, Austria. Lab Rech Polymeres, CNRS, UMR 7581, F-94320 Thiais, France. RP Israel, G (reprint author), Univ Paris 06, ISPL, Serv Aeron, CNRS,UMR 7620, F-91371 Verrieres Le Buisson, France. RI Hauchecorne, Alain/A-8489-2013; szopa, cyril/C-6865-2015 OI szopa, cyril/0000-0002-0090-4056 NR 9 TC 0 Z9 0 U1 0 U2 4 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 30 PY 2006 VL 444 IS 7119 BP E6 EP E7 DI 10.1038/nature05418 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 110KK UT WOS:000242377600035 ER PT J AU Tan, B Woodcock, CE Hu, J Zhang, P Ozdogan, M Huang, D Yang, W Knyazikhin, Y Myneni, RB AF Tan, B. Woodcock, C. E. Hu, J. Zhang, P. Ozdogan, M. Huang, D. Yang, W. Knyazikhin, Y. Myneni, R. B. TI The impact of gridding artifacts on the local spatial properties of MODIS data: Implications for validation, compositing, and band-to-band registration across resolutions SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE moderate resolution imaging spectroradiometer (MODIS); gridding artifacts; geolocation; view zenith angle; triangular Point Spread Function (PSF); band-to-band registration; compositing; validation ID LAI PRODUCT; LAND; NDVI; CLASSIFICATION; FOREST AB Gridding artifacts between observations and predefined grid cells strongly influence the local spatial properties of MODIS images. The sensor observation in any grid cell is only partially derived from the location of the cell, with the average overlap between observations and their grid cells being less than 30%. This mismatch between grid cells and observations has strong implications for the use of reference data for the validation of MODIS products or the training of MODIS algorithms. When generating multidate composites, gridding artifacts introduce bias when spectral compositing criteria are used. Also, results indicate that the ability to generate consistent long-term remote sensing records is dependent on both consistent sensing scenarios (spectral bands, view angle distributions, geolocation error) as well as consistent compositing approaches. The band-to-band registration for the different spatial resolutions of gridded MODIS data can be poor if the different resolutions of data are gridded before aggregation. In all cases it is imprecise to characterize the subpixel properties of the coarser resolution bands using the finer resolution bands due to poor correspondence in the areas from which the observations are derived. All of the band-to-band registration problems are minimized when the MODIS data are aggregated to coarser resolutions. When validating algorithm accuracy, available data on the observation dimensions and the offsets between the grid cell and the observation should be included to ensure the quality of validation results. If this information is not available, MODIS data should be aggregated to coarser resolutions to improve the correspondence between the location of observations and grid cells. (c) 2006 Elsevier Inc. All rights reserved. C1 Boston Univ, Dept Geog & Environm, Boston, MA 02215 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Tan, B (reprint author), Boston Univ, Dept Geog & Environm, 675 Commonwealth Ave, Boston, MA 02215 USA. EM tanbin@crsa.bu.edu RI Yang, Wenze/B-8356-2012; Zhang, Ping/D-7257-2012; Tan, Bin/G-1331-2012; Huang, Dong/H-7318-2014; Myneni, Ranga/F-5129-2012; OI Yang, Wenze/0000-0001-8514-2742; Huang, Dong/0000-0001-9715-6922; Ozdogan, Mutlu/0000-0002-1707-3375 NR 25 TC 153 Z9 155 U1 4 U2 39 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 EI 1879-0704 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD NOV 30 PY 2006 VL 105 IS 2 BP 98 EP 114 DI 10.1016/j.rse.2006.06.008 PG 17 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 108HA UT WOS:000242229700002 ER PT J AU Bourke, MC Balme, M Beyer, RA Williams, KK Zimbelman, J AF Bourke, M. C. Balme, M. Beyer, R. A. Williams, K. K. Zimbelman, J. TI A comparison of methods used to estimate the height of sand dunes on Mars SO GEOMORPHOLOGY LA English DT Article DE aeolian; dune; Mars; morphometry; methods; remote sensing; planetary geology ID GENERAL-CIRCULATION MODEL; ORBITER LASER ALTIMETER; NORTH POLAR-REGION; SOUTHERN PERU; BARCHAN DUNES; TOPOGRAPHY; EVOLUTION; DEPOSITS; RIDGES; ROVER AB The collection of morphometric data on small-scale landforms from other planetary bodies is difficult. We assess four methods that can be used to estimate the height of aeolian dunes on Mars. These are (1) stereography, (2) slip face length, (3) profiling photoclinometry, and (4) Mars Orbiter Laser Altimeter (MOLA). Results show that there is good agreement among the methods when conditions are ideal. However, limitations inherent to each method inhibited their accurate application to all sites. Collectively, these techniques provide data on a range of morphometric parameters, some of which were not previously available for dunes on Mars. They include dune height, width, length, surface area, volume, and longitudinal and transverse profiles. The utilization of these methods will facilitate a more accurate analysis of aeolian dunes on Mars and enable comparison with dunes on other planetary surfaces. (c) 2006 Elsevier B.V. All rights reserved. C1 Planetary Sci Inst, Tucson, AZ 85719 USA. Univ Oxford, Ctr Environm, Oxford OX1 3QY, England. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Smithsonian Inst, Ctr Earth & Planetary Studies, Natl Air & Space Museum, Washington, DC 20013 USA. RP Bourke, MC (reprint author), Planetary Sci Inst, 1700 E Ft Lowell, Tucson, AZ 85719 USA. EM mbourke@psi.edu; mbalms@psi.edu; rbeyer@arc.nasa.gov; williamskk@si.edu; zimbelmanj@si.edu RI Bourke, Mary/I-4387-2012; OI Bourke, Mary/0000-0002-0424-0322; Beyer, Ross/0000-0003-4503-3335; Balme, Matthew/0000-0001-5871-7475 NR 70 TC 28 Z9 28 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X EI 1872-695X J9 GEOMORPHOLOGY JI Geomorphology PD NOV 29 PY 2006 VL 81 IS 3-4 BP 440 EP 452 DI 10.1016/j.geomorph.2006.04.023 PG 13 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 117NJ UT WOS:000242879700015 ER PT J AU Yang, K Koike, T Stackhouse, P Mikovitz, C Cox, SJ AF Yang, Kun Koike, Toshio Stackhouse, Paul Mikovitz, Colleen Cox, Stephen J. TI An assessment of satellite surface radiation products for highlands with Tibet instrumental data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DATA SETS; SOLAR-RADIATION; IRRADIANCE; ATMOSPHERE; ISCCP AB This study presents results of comparisons between instrumental radiation data in Tibet and two satellite products: the Global Energy and Water cycle Experiment Surface Radiation Budget (GEWEX-SRB) and International Satellite Cloud Climatology Project - Flux Data (ISCCP-FD). Severe and systematic errors were found in monthly-mean SRB shortwave radiation (SW) and FD longwave radiation (LW). Errors in diurnal variations are even larger than the monthly mean errors. Though the LW errors can be reduced nearly 10 W m(-2) after an altitudinal correction, the remaining errors are still higher than that for other regions. The large errors in SRB SW were caused by neglecting elevation effects, but the errors in FD LW were mainly due to significant errors in input data. We suggest reanalyzing all ancillary data and reprocessing these satellite surface radiation data, at least for highland areas like Tibet. C1 Univ Tokyo, Dept Civil Engn, Bunkyo Ku, Tokyo 1138656, Japan. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Analyt Serv & Mat Inc, Hampton, VA 23666 USA. RP Yang, K (reprint author), Univ Tokyo, Dept Civil Engn, Bunkyo Ku, Hongo 7-3-1, Tokyo 1138656, Japan. EM yangk@hydra.t.u-tokyo.ac.jp RI Yang, Kun/G-8390-2011 OI Yang, Kun/0000-0002-0809-2371 NR 17 TC 29 Z9 29 U1 0 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 29 PY 2006 VL 33 IS 22 AR L22403 DI 10.1029/2006GL027640 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 115MP UT WOS:000242738700002 ER PT J AU Hong, Y Adler, R Huffman, G AF Hong, Yang Adler, Robert Huffman, George TI Evaluation of the potential of NASA multi-satellite precipitation analysis in global landslide hazard assessment SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RAINFALL INTENSITY; ALPS AB Intense storms with high-intensity, long-duration rainfall have great potential to trigger rapidly moving landslides, resulting in casualties and property damage across the world. In recent years, through the availability of remotely sensed datasets, it has become possible to conduct global-scale landslide hazard assessment. This paper evaluates the potential of the real-time NASA TRMM-based Multi-satellite Precipitation Analysis ( TMPA) system to advance our understanding of, and predictive ability for, rainfall-triggered landslides. Early results show that the landslide occurrences are closely associated with the spatial patterns and temporal distribution of rainfall characteristics. Particularly, the number of landslide occurrences and the relative importance of rainfall in triggering landslides rely on the influence of rainfall attributes ( e. g. rainfall climatology, antecedent rainfall accumulation, and intensity-duration of rainstorms). TMPA precipitation data are available in both real-time and post-real-time versions, which are useful to assess the location and timing of rainfall-triggered landslide hazards by monitoring landslide-prone areas while receiving heavy rainfall. For the purpose of identifying rainfall-triggered landslides, an empirical global rainfall intensity-duration threshold is developed by examining a number of landslide occurrences and their corresponding TMPA precipitation characteristics across the world. These early results, in combination with TRMM real-time precipitation estimation system, may form a starting point for developing an operational early warning system for rainfall-triggered landslides around the globe. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hong, Y (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 613-1, Greenbelt, MD 20771 USA. EM yanghong@agnes.gsfc.nasa.gov RI Hong, Yang/D-5132-2009; Huffman, George/F-4494-2014 OI Hong, Yang/0000-0001-8720-242X; Huffman, George/0000-0003-3858-8308 NR 29 TC 60 Z9 61 U1 1 U2 20 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 28 PY 2006 VL 33 IS 22 AR L22402 DI 10.1029/2006GL028010 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 115MN UT WOS:000242738500008 ER PT J AU Trainer, MG Pavlov, AA DeWitt, HL Jimenez, JL McKay, CP Toon, OB Tolbert, MA AF Trainer, Melissa G. Pavlov, Alexander A. DeWitt, H. Langley Jimenez, Jose L. McKay, Christopher P. Toon, Owen B. Tolbert, Margaret A. TI Organic haze on Titan and the early Earth SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE planetary atmospheres; tholins; atmospheric aerosol; Archaen; astrobiology ID AEROSOL MASS-SPECTROMETER; PHOTOCHEMICAL FORMATION; CHEMICAL EVOLUTION; OPTICAL-CONSTANTS; EARLY ATMOSPHERE; X-RAY; PARTICLES; SIMULATION; DIAMETER; THOLINS AB Recent exploration by the Cassini/Huygens mission has stimulated a great deal of interest in Saturn's moon, Titan. One of Titan's most captivating features is the thick organic haze layer surrounding the moon, believed to be formed from photochemistry high in the CH4/N-2 atmosphere. It has been suggested that a similar haze layer may have formed on the early Earth. Here we report laboratory experiments that demonstrate the properties of haze likely to form through photochemistry on Titan and early Earth. We have used a deuterium lamp to initiate particle production in these simulated atmospheres from UV photolysis. Using a unique analysis technique, the aerosol mass spectrometer, we have studied the chemical composition, size, and shape of the particles produced as a function of initial trace gas composition. Our results show that the aerosols produced in the laboratory can serve as analogs for the observed haze in Titan's atmosphere. Experiments performed under possible conditions for early Earth suggest a significant optical depth of haze may have dominated the early Earth's atmosphere. Aerosol size measurements are presented, and implications for the haze layer properties are discussed. We estimate that aerosol production on the early Earth may have been on the order of 10(14) g(.)year(-1) and thus could have served as a primary source of organic material to the surface. C1 Univ Colorado, Cooperat Inst Res Environm Sci, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Univ Arizona, Dept Planetary Sci Lunar & Planetary Lab, Tucson, AZ 85721 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. RP Tolbert, MA (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Dept Chem & Biochem, UCB 216, Boulder, CO 80309 USA. EM tolbert@cires.colorado.edu RI Jimenez, Jose/A-5294-2008; Trainer, Melissa/E-1477-2012; Pavlov, Alexander/F-3779-2012 OI Jimenez, Jose/0000-0001-6203-1847; Pavlov, Alexander/0000-0001-8771-1646 NR 53 TC 73 Z9 73 U1 1 U2 27 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 28 PY 2006 VL 103 IS 48 BP 18035 EP 18042 DI 10.1073/pnas.0608561103 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 111PJ UT WOS:000242465200004 PM 17101962 ER PT J AU Mazin, BA Bumble, B Day, PK Eckart, ME Golwala, S Zmuidzinas, J Harrison, FA AF Mazin, Benjamin A. Bumble, Bruce Day, Peter K. Eckart, Megan E. Golwala, Sunil Zmuidzinas, Jonas Harrison, Fiona A. TI Position sensitive x-ray spectrophotometer using microwave kinetic inductance detectors SO APPLIED PHYSICS LETTERS LA English DT Article ID TRANSITION EDGE SENSORS; HIGH-RESOLUTION; MICROCALORIMETER; ARRAYS; SPECTROMETER; MULTIPLEXER; DYNAMICS; ENERGY AB The surface impedance of a superconductor changes when energy is absorbed and Cooper pairs are broken to produce single electron (quasiparticle) excitations. This change may be sensitively measured using a thin-film resonant circuit called a microwave kinetic inductance detector (MKID). The practical application of MKIDs for photon detection requires a method of efficiently coupling the photon energy to the MKID. The authors present results on position sensitive x-ray detectors made by using two aluminum MKIDs on either side of a tantalum photon absorber strip. Diffusion constants, recombination times, and energy resolution are reported. MKIDs can easily be scaled into large arrays. (c) 2006 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Dept Phys, Pasadena, CA 91125 USA. RP Mazin, BA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 169-506, Pasadena, CA 91109 USA. EM benjamin.mazin@jpl.nasa.gov RI Mazin, Ben/B-8704-2011 OI Mazin, Ben/0000-0003-0526-1114 NR 22 TC 55 Z9 55 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 27 PY 2006 VL 89 IS 22 AR 222507 DI 10.1063/1.2390664 PG 3 WC Physics, Applied SC Physics GA 112PJ UT WOS:000242538500067 ER PT J AU Das, M Barut, A Madenci, E Ambur, DR AF Das, M. Barut, A. Madenci, E. Ambur, D. R. TI A triangular plate element for thermo-elastic analysis of sandwich panels with a functionally graded core SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE sandwich construction; FGM; single-layer theory; finite element; hybrid formulation ID NONUNIFORM TEMPERATURE DISTRIBUTION; THERMAL POSTBUCKLING BEHAVIOR; LAMINATED COMPOSITE PLATES; COMPLETE STRESS-FIELD; SINGLE-LAYER THEORY; FINITE-ELEMENT; ELASTICITY SOLUTION; SHEAR DEFORMATION AB A sandwich construction is commonly composed of a single soft isotropic core with relatively stiff orthotropic face sheets. The stiffness of the core may be functionally graded through the thickness in order to reduce the interfacial shear stresses. In analysing sandwich panels with a functionally gradient core, the three-dimensional conventional finite elements or elements based on the layerwise (zig-zag) theory can be used. Although these elements accurately model a sandwich panel, they are computationally costly when the core is modelled as composed of several layers due to its grading material properties. An alternative to these elements is an element based on a single-layer plate theory in which the weighted-average field variables capture the panel deformation in the thickness direction. This study presents a new triangular finite element based on {3, 2}-order single-layer theory for modelling thick sandwich panels with or without a functionally graded core subjected to thermo-mechanical loading. A hybrid energy functional is employed in the derivation of the element because of a C-1 interelement continuity requirement. The variations of temperature and distributed loading acting on the top and bottom surfaces are non-uniform. The temperature also varies arbitrarily through the thickness. Copyright (c) 2006 John Wiley & Sons, Ltd. C1 Univ Arizona, Dept Aerosp & Mech Engn, Tucson, AZ 85721 USA. NASA, Glenn Res Ctr, Mat & Struct Div, Cleveland, OH 44135 USA. RP Madenci, E (reprint author), Univ Arizona, Dept Aerosp & Mech Engn, POB 210119, Tucson, AZ 85721 USA. EM mdas@email.arizona.edu; atila@u.arizona.edu; madenci@email.arizona.edu; Damodar.R.Ambur@nasa.gov NR 19 TC 19 Z9 22 U1 0 U2 6 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD NOV 26 PY 2006 VL 68 IS 9 BP 940 EP 966 DI 10.1002/nme.1724 PG 27 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 112EI UT WOS:000242507900002 ER PT J AU Noh, YJ Liu, GS Seo, EK Wang, JR Aonashi, K AF Noh, Yoo-Jeong Liu, Guosheng Seo, Eun-Kyoung Wang, James R. Aonashi, Kazumasa TI Development of a snowfall retrieval algorithm at high microwave frequencies SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SINGLE SCATTERING PROPERTIES; WAVE IMAGING RADIOMETER; ICE; CLOUD; PRECIPITATION; RADAR; PARAMETERS; MODEL; APPROXIMATION; SENSITIVITY AB A snowfall retrieval algorithm based on Bayes' theorem is developed using high-frequency microwave satellite data. In this algorithm, observational data from both airborne and surface-based radars are used to construct an a priori database of snowfall profiles. These profiles are then used as input to a forward radiative transfer model to obtain brightness temperatures at high microwave frequencies. In the radiative transfer calculations, two size distributions for snowflakes and ten observed atmospheric sounding profiles are used with snowfall profiles from observations. In addition, the scattering properties of the snowflakes are calculated on the basis of realistic nonspherical shapes using discrete dipole approximation. The algorithm is first verified by airborne microwave and radar observations and then applied to the Advanced Microwave Sounding Unit-B (AMSU-B) satellite data. The retrieved snowfall rates using AMSU-B data from three snowfall cases in the vicinity of Japan show reasonable agreement with surface radar observations with correlation coefficients of about 0.8, 0.6, and 0.96 for the three cases, respectively. The comparison results also suggest the algorithm performs better for dry and heavy snow cases, but is less accurate for wet and weak snow cases. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL USA. NASA Goddard Space Flight Ctr, Greenbelt, MD USA. Japan Meteorol Agcy, Meteorol Res Inst, Tsukuba, Ibaraki, Japan. RP Noh, YJ (reprint author), Colorado State Univ, Cooperat Inst Res Atmsophos, Ft Collins, CO USA. EM noh@cira.colostate.edu RI Liu, Guosheng/D-3479-2011; Measurement, Global/C-4698-2015; PMM, JAXA/K-8537-2016 OI Liu, Guosheng/0000-0001-7899-6125; NR 42 TC 29 Z9 29 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 25 PY 2006 VL 111 IS D22 AR D22216 DI 10.1029/2005JD006826 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 110HI UT WOS:000242368700001 ER PT J AU Paillou, P Crapeau, M Elachi, C Wall, S Encrenaz, P AF Paillou, Philippe Crapeau, Marc Elachi, Charles Wall, Stephen Encrenaz, Pierre TI Models of synthetic aperture radar backscattering for bright flows and dark spots on Titan SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID CASSINI RADAR; SURFACE AB The synthetic aperture radar (SAR) imaging mode of the Cassini RADAR instrument enables us to map the surface of Titan through its thick atmosphere. The first Cassini close flyby, acquired on 26 October 2004, revealed a complex surface, with areas of low relief and dome-like volcanic constructs, flows, and sinuous channels. In particular, fan-like features with strong radar backscattering were observed. Such structures, extending from tens of kilometers to more than 200 km in length, could be the result of cryovolcanism. Several radar dark spots, up to 30 km across, were also observed; they may correspond to smooth hydrocarbon deposits. We present here a first modeling of these radar-bright and radar-dark features on the basis of classical radar backscattering models. We considered two main materials which could constitute the surface of Titan, tholins and water-ammonia ice, and modeled both single- and two-layer cases, taking into account volume and subsurface scattering. Our results show that SAR-bright regions could better be explained by the effect of a thin layer of water-ammonia ice covering a tholin substratum. Radar-dark spots can be modeled in two ways: a rough tholin surface or a smooth one with some volume scattering. We show that multi-incidence SAR data could help discriminate between the various scenarios proposed. C1 Observ Aquitain Sci Univers, UMR 5804, F-33270 Floirac, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Observ Paris, Lab Etud Rayonnement & Mat Astrophys, F-75014 Paris, France. RP Paillou, P (reprint author), Observ Aquitain Sci Univers, UMR 5804, F-33270 Floirac, France. EM philippe.paillou@obs.u-bordeaux1.fr NR 20 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 25 PY 2006 VL 111 IS E11 AR E11011 DI 10.1029/2006JE002724 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 110HT UT WOS:000242369800001 ER PT J AU Ostro, SJ Margot, JL Benner, LAM Giorgini, JD Scheeres, DJ Fahnestock, EG Broschart, SB Bellerose, J Nolan, MC Magri, C Pravec, P Scheirich, P Rose, R Jurgens, RF De Jong, EM Suzuki, S AF Ostro, Steven. J. Margot, Jean-Luc Benner, Lance A. M. Giorgini, Jon D. Scheeres, Daniel J. Fahnestock, Eugene G. Broschart, Stephen B. Bellerose, Julie Nolan, Michael C. Magri, Christopher Pravec, Petr Scheirich, Petr Rose, Randy Jurgens, Raymond F. De Jong, Eric M. Suzuki, Shigeru TI Radar Imaging of binary near-Earth asteroid (66391) 1999 KW4 SO SCIENCE LA English DT Article ID CROSSING ASTEROIDS; POPULATION; DENSITY; MASS AB High-resolution radar images reveal near-Earth asteroid ( 66391) 1999 KW4 to be a binary system. The similar to 1.5-kilometer-diameter primary ( Alpha) is an unconsolidated gravitational aggregate with a spin period similar to 2.8 hours, bulk density similar to 2 grams per cubic centimeter, porosity similar to 50%, and an oblate shape dominated by an equatorial ridge at the object's potential-energy minimum. The similar to 0.5-kilometer secondary ( Beta) is elongated and probably is denser than Alpha. Its average orbit about Alpha is circular with a radius similar to 2.5 kilometers and period similar to 17.4 hours, and its average rotation is synchronous with the long axis pointed toward Alpha, but librational departures from that orientation are evident. Exotic physical and dynamical properties may be common among near-Earth binaries. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. Arecibo Observ, Arecibo, PR 00612 USA. Univ Maine, Farmington, ME 04938 USA. Acad Sci Czech Republ, Astron Inst, CZ-25165 Ondrejov, Czech Republic. RP Ostro, SJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ostro@reason.jpl.nasa.gov RI Margot, Jean-Luc/A-6154-2012; Nolan, Michael/H-4980-2012; Pravec, Petr/G-9037-2014; Scheirich, Peter/H-4331-2014 OI Margot, Jean-Luc/0000-0001-9798-1797; Nolan, Michael/0000-0001-8316-0680; Scheirich, Peter/0000-0001-8518-9532 NR 23 TC 127 Z9 128 U1 0 U2 5 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD NOV 24 PY 2006 VL 314 IS 5803 BP 1276 EP 1280 DI 10.1126/science.1133622 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 108BR UT WOS:000242215800036 PM 17038586 ER PT J AU Scheeres, DJ Fahnestock, EG Ostro, SJ Margot, JL Benner, LAM Broschart, SB Bellerose, J Giorgini, JD Nolan, MC Magri, C Pravec, P Scheirich, P Rose, R Jurgens, RF De Jong, EM Suzuki, S AF Scheeres, D. J. Fahnestock, E. G. Ostro, S. J. Margot, J. -L. Benner, L. A. M. Broschart, S. B. Bellerose, J. Giorgini, J. D. Nolan, M. C. Magri, C. Pravec, P. Scheirich, P. Rose, R. Jurgens, R. F. De Jong, E. M. Suzuki, S. TI Dynamical configuration of binary near-Earth asteroid (66391) 1999 KW4 SO SCIENCE LA English DT Article ID RIGID BODIES; ASTEROIDS; MOTION; MODEL AB Dynamical simulations of the coupled rotational and orbital dynamics of binary near-Earth asteroid 66391 ( 1999 KW4) suggest that it is excited as a result of perturbations from the Sun during perihelion passages. Excitation of the mutual orbit will stimulate complex fluctuations in the orbit and rotation of both components, inducing the attitude of the smaller component to have large variation within some orbits and to hardly vary within others. The primary's proximity to its rotational stability limit suggests an origin from spin-up and disruption of a loosely bound precursor within the past million years. C1 Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Arecibo Observ, Arecibo, PR 00612 USA. Univ Maine, Dept Nat Sci, Farmington, ME 04938 USA. Acad Sci Czech Republ, Astron Inst, CZ-25165 Ondrejov, Czech Republic. RP Scheeres, DJ (reprint author), Univ Michigan, Dept Aerosp Engn, 1320 Beal Ave, Ann Arbor, MI 48109 USA. EM scheeres@umich.edu RI Margot, Jean-Luc/A-6154-2012; Nolan, Michael/H-4980-2012; Pravec, Petr/G-9037-2014; Scheirich, Peter/H-4331-2014 OI Margot, Jean-Luc/0000-0001-9798-1797; Nolan, Michael/0000-0001-8316-0680; Scheirich, Peter/0000-0001-8518-9532 NR 25 TC 61 Z9 61 U1 0 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD NOV 24 PY 2006 VL 314 IS 5803 BP 1280 EP 1283 DI 10.1126/science.1133599 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 108BR UT WOS:000242215800037 PM 17038588 ER PT J AU Luthcke, SB Zwally, HJ Abdalati, W Rowlands, DD Ray, RD Nerem, RS Lemoine, FG McCarthy, JJ Chinn, DS AF Luthcke, S. B. Zwally, H. J. Abdalati, W. Rowlands, D. D. Ray, R. D. Nerem, R. S. Lemoine, F. G. McCarthy, J. J. Chinn, D. S. TI Recent Greenland ice mass loss by drainage system from satellite gravity observations SO SCIENCE LA English DT Article ID SHEET; SURFACE; BALANCE; VARIABILITY; GRACE; EARTH AB Mass changes of the Greenland Ice Sheet resolved by drainage system regions were derived from a local mass concentration analysis of NASA - Deutsches Zentrum fur Luft- und Raumfahrt Gravity Recovery and Climate Experiment ( GRACE mission) observations. From 2003 to 2005, the ice sheet lost 101 +/- 16 gigaton/year, with a gain of 54 gigaton/year above 2000 meters and a loss of 155 gigaton/year at lower elevations. The lower elevations show a large seasonal cycle, with mass losses during summer melting followed by gains from fall through spring. The overall rate of loss reflects a considerable change in trend ( - 113 +/- 17 gigaton/ year) from a near balance during the 1990s but is smaller than some other recent estimates. C1 NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Cryospher Sci Branch, Greenbelt, MD 20771 USA. Univ Colorado, Dept Aerosp Engn Sci, Cooperat Inst Res Environm Sci, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA. SGT Inc, Div Sci, Greenbelt, MD 20770 USA. RP Luthcke, SB (reprint author), NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Code 698, Greenbelt, MD 20771 USA. EM Scott.B.Luthcke@nasa.gov RI Ray, Richard/D-1034-2012; Rowlands, David/D-2751-2012; Luthcke, Scott/D-6283-2012; Lemoine, Frank/D-1215-2013 NR 20 TC 231 Z9 242 U1 6 U2 45 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD NOV 24 PY 2006 VL 314 IS 5803 BP 1286 EP 1289 DI 10.1126/science.1130776 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 108BR UT WOS:000242215800039 PM 17053112 ER PT J AU Eyring, V Butchart, N Waugh, DW Akiyoshi, H Austin, J Bekki, S Bodeker, GE Boville, BA Bruhl, C Chipperfield, MP Cordero, E Dameris, M Deushi, M Fioletov, VE Frith, SM Garcia, RR Gettelman, A Giorgetta, MA Grewe, V Jourdain, L Kinnison, DE Mancini, E Manzini, E Marchand, M Marsh, DR Nagashima, T Newman, PA Nielsen, JE Pawson, S Pitari, G Plummer, DA Rozanov, E Schraner, M Shepherd, TG Shibata, K Stolarski, RS Struthers, H Tian, W Yoshiki, M AF Eyring, V. Butchart, N. Waugh, D. W. Akiyoshi, H. Austin, J. Bekki, S. Bodeker, G. E. Boville, B. A. Bruehl, C. Chipperfield, M. P. Cordero, E. Dameris, M. Deushi, M. Fioletov, V. E. Frith, S. M. Garcia, R. R. Gettelman, A. Giorgetta, M. A. Grewe, V. Jourdain, L. Kinnison, D. E. Mancini, E. Manzini, E. Marchand, M. Marsh, D. R. Nagashima, T. Newman, P. A. Nielsen, J. E. Pawson, S. Pitari, G. Plummer, D. A. Rozanov, E. Schraner, M. Shepherd, T. G. Shibata, K. Stolarski, R. S. Struthers, H. Tian, W. Yoshiki, M. TI Assessment of temperature, trace species, and ozone in chemistry-climate model simulations of the recent past SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID HALOGEN OCCULTATION EXPERIMENT; GRAVITY-WAVE-DRAG; GENERAL-CIRCULATION MODEL; TROPICAL TROPOPAUSE TEMPERATURES; DOPPLER-SPREAD PARAMETERIZATION; QUASI-BIENNIAL OSCILLATION; STRATOSPHERIC WATER-VAPOR; MIDDLE ATMOSPHERE MODEL; OFFICE UNIFIED MODEL; INTERACTIVE CHEMISTRY AB Simulations of the stratosphere from thirteen coupled chemistry-climate models (CCMs) are evaluated to provide guidance for the interpretation of ozone predictions made by the same CCMs. The focus of the evaluation is on how well the fields and processes that are important for determining the ozone distribution are represented in the simulations of the recent past. The core period of the evaluation is from 1980 to 1999 but long-term trends are compared for an extended period (1960-2004). Comparisons of polar high-latitude temperatures show that most CCMs have only small biases in the Northern Hemisphere in winter and spring, but still have cold biases in the Southern Hemisphere spring below 10 hPa. Most CCMs display the correct stratospheric response of polar temperatures to wave forcing in the Northern, but not in the Southern Hemisphere. Global long-term stratospheric temperature trends are in reasonable agreement with satellite and radiosonde observations. Comparisons of simulations of methane, mean age of air, and propagation of the annual cycle in water vapor show a wide spread in the results, indicating differences in transport. However, for around half the models there is reasonable agreement with observations. In these models the mean age of air and the water vapor tape recorder signal are generally better than reported in previous model intercomparisons. Comparisons of the water vapor and inorganic chlorine (Cl-y) fields also show a large intermodel spread. Differences in tropical water vapor mixing ratios in the lower stratosphere are primarily related to biases in the simulated tropical tropopause temperatures and not transport. The spread in Cly, which is largest in the polar lower stratosphere, appears to be primarily related to transport differences. In general the amplitude and phase of the annual cycle in total ozone is well simulated apart from the southern high latitudes. Most CCMs show reasonable agreement with observed total ozone trends and variability on a global scale, but a greater spread in the ozone trends in polar regions in spring, especially in the Arctic. In conclusion, despite the wide range of skills in representing different processes assessed here, there is sufficient agreement between the majority of the CCMs and the observations that some confidence can be placed in their predictions. C1 Deutsch Zentrum Luft & Raumfahrt, Inst Phys Atmosphare, D-82234 Wessling, Germany. Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. CNRS, Serv Aeron, F-75252 Paris, France. Natl Inst Water & Atmospher Res, Lauder, New Zealand. Met Off, Climate Res Div, Exeter EX1 3PB, Devon, England. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Max Planck Inst Chem, D-55128 Mainz, Germany. Univ Leeds, Inst Atmospher Sci, Leeds LS2 9JT, W Yorkshire, England. San Jose State Univ, Dept Meteorol, San Jose, CA 95192 USA. Deutsch Zentrum Luft & Raumfahrt, Inst Phys Atmospher, D-82234 Wessling, Germany. Meteorol Res Inst, Tsukuba, Ibaraki 3050052, Japan. Environm Canada, Toronto, ON M3H 5T4, Canada. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. Univ Aquila, Dipartimento Fis, I-67010 Laquila, Italy. Ist Nazl Geofis & Vulcanol, I-40128 Bologna, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ouranos Consortium, Montreal, PQ H3A 1B9, Canada. Observ World Radiat Ctr, Phys Meteorol Observ, CH-7260 Davos, Switzerland. ETH, Inst Atmospher & Climate Sci, CH-8092 Zurich, Switzerland. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. RP Eyring, V (reprint author), Deutsch Zentrum Luft & Raumfahrt, Inst Phys Atmosphare, Oberpfaffenhofen, D-82234 Wessling, Germany. EM veronika.eyring@dlr.de RI Marsh, Daniel/A-8406-2008; Rozanov, Eugene/A-9857-2012; Grewe, Volker/A-6147-2011; Manzini, Elisa/H-5760-2011; Newman, Paul/D-6208-2012; Stolarski, Richard/B-8499-2013; Chipperfield, Martyn/H-6359-2013; bekki, slimane/J-7221-2015; Pawson, Steven/I-1865-2014; Waugh, Darryn/K-3688-2016; Pitari, Giovanni/O-7458-2016; Eyring, Veronika/O-9999-2016 OI Mancini, Eva/0000-0001-7071-0292; Fioletov, Vitali/0000-0002-2731-5956; Marsh, Daniel/0000-0001-6699-494X; Rozanov, Eugene/0000-0003-0479-4488; Grewe, Volker/0000-0002-8012-6783; Newman, Paul/0000-0003-1139-2508; Stolarski, Richard/0000-0001-8722-4012; Chipperfield, Martyn/0000-0002-6803-4149; bekki, slimane/0000-0002-5538-0800; Pawson, Steven/0000-0003-0200-717X; Waugh, Darryn/0000-0001-7692-2798; Pitari, Giovanni/0000-0001-7051-9578; Eyring, Veronika/0000-0002-6887-4885 NR 124 TC 289 Z9 297 U1 10 U2 45 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 23 PY 2006 VL 111 IS D22 AR D22308 DI 10.1029/2006JD007327 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 110HH UT WOS:000242368600008 ER PT J AU Hall, F Masek, JG Collatz, GJ AF Hall, Forrest Masek, Jeffrey G. Collatz, G. James TI Evaluation of ISLSCP Initiative IIFASIR and GIMMS NDVI products and implications for carbon cycle science SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HIGH-RESOLUTION RADIOMETER; DIFFERENCE VEGETATION INDEX; LEAF-AREA INDEX; ATMOSPHERIC CO2; AVHRR DATA; ECOSYSTEM PRODUCTION; SURFACE-TEMPERATURE; CLIMATE VARIABILITY; HILBERT SPECTRUM; SEASONAL CYCLE AB Integration of NDVI data into ecological and biogeochemical modeling has placed more stringent requirements on the accuracy and stability of the measurement. We compare two recent AVHRR NDVI data sets included as part of ISLSCP Initiative II: (1) the Fourier-Adjusted, Sensor and Solar zenith angle corrected, Interpolated, Reconstructed (FASIR) monthly time series and (2) the Global Inventory Modeling and Mapping Studies (GIMMS) monthly time series. Although both started with nearly identical composited AVHRR GAC data sets, each data set has been processed differently to reduce sensor, atmospheric, and illumination effects that vary over time. We find that the resulting absolute NDVI data records differ substantially and consistently for large parts of the globe. These differences also propagate into the NDVI anomaly record (e.g., deviations from monthly or annual means) particularly in the 1984-1985, 1994 periods. To assess the effect of these differences on predictions of land surface CO2 fluxes, the fraction of absorbed photosynthetically active radiation (fPAR) was calculated from each record, and used to drive a biogeochemical model (CASA). On a global basis, calculated net ecosystem exchange shows large variability inherited from the NDVI records. However, these variations do not match global CO2 fluxes derived from atmospheric inversion of CO2 concentration measurements. We conclude that other processes (burning, physiologic response to stress) are likely responsible for major anomalies in the observed global land net carbon fluxes to the atmosphere during the period 1982-1998. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hall, F (reprint author), NASA, Goddard Space Flight Ctr, Code 614-4, Greenbelt, MD 20771 USA. EM fghall@ltpmail.gsfc.nasa.gov RI collatz, george/D-5381-2012; Masek, Jeffrey/D-7673-2012 NR 62 TC 17 Z9 18 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 23 PY 2006 VL 111 IS D22 AR D22S08 DI 10.1029/2006JD007438 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 110HH UT WOS:000242368600010 ER PT J AU Koster, RD Fekete, BM Huffman, GJ Stackhouse, PW AF Koster, Randal D. Fekete, Balazs M. Huffman, George J. Stackhouse, Paul W., Jr. TI Revisiting a hydrological analysis framework with International Satellite Land Surface Climatology Project Initiative 2 rainfall, net radiation, and runoff fields SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SPACE-TIME CLIMATE; INTERANNUAL VARIABILITY; SOLAR-RADIATION; PRECIPITATION; FLUXES; WATER; ATMOSPHERE AB The International Satellite Land Surface Climatology Project Initiative 2 (ISLSCP-2) data set provides the data needed to characterize the surface water budget across much of the globe in terms of energy availability (net radiation) and water availability (precipitation) controls. The data, on average, are shown to be consistent with Budyko's decades-old framework, thereby demonstrating the continuing relevance of Budyko's semiempirical relationships. This consistency, however, appears only when a small subset of the data with hydrologically suspicious behavior is removed from the analysis. In general, the precipitation, net radiation, and runoff data also appear consistent in their interannual variability and in the phasing of their seasonal cycles. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Univ New Hampshire, Water Syst Anal Grp, Complex Syst Res Ctr, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Koster, RD (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM randal.d.koster@nasa.gov RI Koster, Randal/F-5881-2012; Huffman, George/F-4494-2014 OI Koster, Randal/0000-0001-6418-6383; Huffman, George/0000-0003-3858-8308 NR 31 TC 14 Z9 14 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 23 PY 2006 VL 111 IS D22 AR D22S05 DI 10.1029/2006JD007182 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 110HH UT WOS:000242368600006 ER PT J AU Israel, G Szopa, C Raulin, F Cabane, M Niemann, HB Atreya, SK Bauer, SJ Brun, JF Chassefiere, E Coll, P Conde, E Coscia, D Hauchecorne, A Millian, P Nguyen, MJ Owen, T Riedler, W Samuelson, RE Siguier, JM Steller, M Sternberg, R Vidal-Madjar, C AF Israel, G. Szopa, C. Raulin, F. Cabane, M. Niemann, H. B. Atreya, S. K. Bauer, S. J. Brun, J. -F. Chassefiere, E. Coll, P. Conde, E. Coscia, D. Hauchecorne, A. Millian, P. Nguyen, M. J. Owen, T. Riedler, W. Samuelson, R. E. Siguier, J. -M. Steller, M. Sternberg, R. Vidal-Madjar, C. TI Astrochemistry - Complex organic matter in Titan's aerosols? Reply SO NATURE LA English DT Letter ID THOLINS; ATMOSPHERE C1 Univ Paris 06, ISPL, Serv Aeron, CNRS,UMR 7620, F-91371 Verrieres Le Buisson, France. Univ Versailles, ISPL, Serv Aeron, CNRS,UMR 7620, F-91371 Verrieres Le Buisson, France. Univ Paris 12, Lab Interuniv Syst Atmospher, CNRS, UMR 7583, F-94010 Creteil, France. Univ Paris 07, Lab Interuniv Syst Atmospher, CNRS, UMR 7583, F-94010 Creteil, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Graz Univ, Inst Meteorol & Geophys, A-8010 Graz, Austria. Ctr Natl Etud Spatiales, F-31401 Toulouse, France. Off Natl Etud & Rech Aerosp, F-31055 Toulouse, France. Univ Hawaii Manoa, Inst Astron, Honolulu, HI 96822 USA. Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Austrian Acad Sci, Inst Weltraumforsch, A-8042 Graz, Austria. Lab Rech Polymeres, CNRS, UMR 7581, F-94320 Thiais, France. RP Israel, G (reprint author), Univ Paris 06, ISPL, Serv Aeron, CNRS,UMR 7620, F-91371 Verrieres Le Buisson, France. RI Hauchecorne, Alain/A-8489-2013; szopa, cyril/C-6865-2015; OI szopa, cyril/0000-0002-0090-4056; Bauer, Siegfried/0000-0003-4213-2047; Siguier, Jean-Michel/0000-0003-3568-9816; Hauchecorne, Alain/0000-0001-9888-6994 NR 9 TC 0 Z9 0 U1 0 U2 5 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 23 PY 2006 VL 444 IS 7118 BP E6 EP E7 DI 10.1038/nature05418 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 108BQ UT WOS:000242215700035 ER PT J AU Moore, L Nagy, AF Kliore, AJ Muller-Wodarg, I Richardson, JD Mendillo, M AF Moore, Luke Nagy, Andrew F. Kliore, Arvydas J. Mueller-Wodarg, Ingo Richardson, John D. Mendillo, Michael TI Cassini radio occultations of Saturn's ionosphere: Model comparisons using a constant water flux SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERE; PLASMA; PHOTOCHEMISTRY; ENCELADUS; JUPITER; PLANETS; INFLUX; OXYGEN; RINGS AB Recent radio occultations of Saturn's equatorial ionosphere by the Cassini spacecraft provide important insight into this poorly constrained region. Twelve new electron density profiles identify a clear dawn/dusk asymmetry as well as two apparently separate electron density peaks. This study uses a 3D general circulation model along with 1D water diffusion calculations to examine the possibility that a topside flux of neutral water into Saturn's atmosphere may provide a loss mechanism - via charge exchange with protons - that is sufficient to reproduce the ionosphere observed by Cassini. Results indicate that a constant influx of water of (0.5 - 1.0) x 10(7) H(2)O cm(-2) sec(-1) is adequate for reproducing Cassini measurements, providing a good match to the main electron density peak at dawn and dusk. In addition, these calculations use a reduced rate for the reaction H(+) + H(2)(nu >= 4) --> H(2)(+) + H, significantly diminishing its importance in Saturn's ionospheric photochemistry. C1 Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Imperial Coll, Dept Phys & Astron, London W1P 7PP, England. MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. RP Moore, L (reprint author), Boston Univ, Ctr Space Phys, 725 Commonwealth Ave, Boston, MA 02215 USA. EM moore@bu.edu RI Mendillo, Michael /H-4397-2014; Mueller-Wodarg, Ingo/M-9945-2014; OI Mueller-Wodarg, Ingo/0000-0001-6308-7826; Moore, Luke/0000-0003-4481-9862 NR 29 TC 29 Z9 29 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 22 PY 2006 VL 33 IS 22 AR L22202 DI 10.1029/2006GL027375 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 110HB UT WOS:000242367900002 ER PT J AU Rinsland, CP Luo, M Logan, JA Beer, R Worden, H Kulawik, SS Rider, D Osterman, G Gunson, M Eldering, A Goldman, A Shephard, M Clough, SA Rodgers, C Lampel, M Chiou, L AF Rinsland, Curtis P. Luo, Ming Logan, Jennifer A. Beer, Reinhard Worden, Helen Kulawik, Susan S. Rider, David Osterman, Greg Gunson, Michael Eldering, Annmarie Goldman, Aaron Shephard, Mark Clough, Shepard A. Rodgers, Clive Lampel, Michael Chiou, Linda TI Nadir measurements of carbon monoxide distributions by the Tropospheric Emission Spectrometer instrument onboard the Aura Spacecraft: Overview of analysis approach and examples of initial results SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MOLECULAR SPECTROSCOPIC DATABASE; RETRIEVALS; ATMOSPHERE; CHEMISTRY; SYSTEMS; MOPITT; MODEL; CO AB We provide an overview of the nadir measurements of carbon monoxide ( CO) obtained thus far by the Tropospheric Emission Spectrometer (TES). The instrument is a high resolution array Fourier transform spectrometer designed to measure infrared spectral radiances from low Earth orbit. It is one of four instruments successfully launched onboard the Aura platform into a sun synchronous orbit at an altitude of 705 km on July 15, 2004 from Vandenberg Air Force Base, California. Nadir spectra are recorded at 0.06-cm(-1) spectral resolution with a nadir footprint of 5 x 8 km. We describe the TES retrieval approach for the analysis of the nadir measurements, report averaging kernels for typical tropical and polar ocean locations, characterize random and systematic errors for those locations, and describe instrument performance changes in the CO spectral region as a function of time. Sample maps of retrieved CO for the middle and upper troposphere from global surveys during December 2005 and April 2006 highlight the potential of the results for measurement and tracking of global pollution and determining air quality from space. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Univ Denver, Dept Phys, Denver, CO 80208 USA. Atmospher & Environm Res Inc, Lexington, MA 02421 USA. Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. Raytheon Co, Pasadena, CA 91101 USA. Sci Applicat Int Corp, Hampton, VA 23666 USA. RP Rinsland, CP (reprint author), NASA, Langley Res Ctr, Mail Stop 401A, Hampton, VA 23681 USA. EM c.p.rinsland@larc.nasa.gov NR 26 TC 50 Z9 50 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 22 PY 2006 VL 33 IS 22 AR L22806 DI 10.1029/2006GL027000 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 110HB UT WOS:000242367900001 ER PT J AU Imhoff, ML Bounoua, L AF Imhoff, Marc L. Bounoua, Lahouari TI Exploring global patterns of net primary production carbon supply and demand using satellite observations and statistical data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SURFACE PARAMETERIZATION SIB2; HUMAN APPROPRIATION; ATMOSPHERIC GCMS; CLIMATE; PHOTOSYNTHESIS; ECOSYSTEMS; INDICATOR AB A unique combination of satellite and socioeconomic data were used to explore the relationship between human consumption and the carbon cycle. The amount of Earth's net primary production (NPP) required to support human activities is a powerful measure of the aggregate impact on the biosphere and indicator of societal vulnerability to climate change. Biophysical models were applied to consumption data to estimate the annual amount of Earth's terrestrial net primary production humans require for food, fiber (including fabrication) and fuel using the same modeling architecture as satellite-supported NPP measurements. The amount of NPP required was calculated on a per capita basis and projected onto a global map of population to create a spatially explicit map of NPP-carbon "demand'' in units of elemental carbon. NPP demand was compared to a map of Earth's average annual net primary production or "supply'' created using 17 years (1982-1998) of AVHRR vegetation index to produce a geographically accurate balance sheet of NPP-carbon "supply'' and "demand'' for the globe. Globally, humans consume 20% of Earth's total net primary production on land. Regionally, the NPP-carbon balance percentage varies from 6% to over 70% and locally from near 0% to over 30,000% in major urban areas. Scenarios modeling the impact of per capita consumption, population growth, and technology suggest that NPP demand is likely to increase substantially in the next 40 years despite better harvesting and processing efficiencies. C1 NASA Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD USA. RP Imhoff, ML (reprint author), NASA Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD USA. EM marc.l.imhoff@nasa.gov NR 54 TC 25 Z9 25 U1 2 U2 18 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 22 PY 2006 VL 111 IS D22 AR D22S12 DI 10.1029/2006JD007377 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 110HG UT WOS:000242368500002 ER PT J AU Kelley, CA Prufert-Bebout, LE Bebout, BM AF Kelley, Cheryl A. Prufert-Bebout, Leslie E. Bebout, Brad M. TI Changes in carbon cycling ascertained by stable isotopic analyses in a hypersaline microbial mat SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES LA English DT Article ID DISSOLVED ORGANIC-CARBON; DIFFUSION-COEFFICIENTS; MERIDIANI-PLANUM; MARINE-SEDIMENTS; GUERRERO-NEGRO; METHANE; WATER; BIOGEOCHEMISTRY; FRACTIONATION; ENVIRONMENTS AB Modern microbial mats have been used as analogs for early life because of the longevity of microbial life on Earth. Mats collected from hypersaline salterns in Baja California were maintained for over a year and a half under both normal (85 ppt salinity, 50 mM SO42-) and reduced salinity (35 ppt salinity; near modern seawater) and sulfate concentrations (20 mM, <= 1 mM SO42-) to assess carbon processing under sulfate conditions more similar to the Archean oceans. As sulfate was removed from the mats by diffusion out into the overlying water, methane concentrations within the mats increased. Highest methane concentrations occurred in mats with reduced salinity and little sulfate. The delta C-13 values of bulk particulate organic matter in all of the mats averaged -11 parts per thousand, similar to what had been observed previously for these Microcoleus mats. In mats with sulfate, pore water concentrations of dissolved inorganic carbon (DIC) delta(13) C values averaged about -3 parts per thousand. However, in the mats with <= 1 mM sulfate concentrations, the DIC delta C-13 values increased substantially with depth, from about -1 parts per thousand in the overlying water to +10 parts per thousand by 20 mm depth. Rates of methanogenesis, calculated from pore water dissolved methane concentration profiles, were too low to account for the total increase in DIC delta C-13 values. These positive isotopic signatures, however, are also consistent with the occurrence of acetogenesis, as are the higher acetate concentrations in the low-sulfate mats. Acetogens may be poised to become successful competitors for substrates in these mats, given the right environmental conditions. C1 Univ Missouri, Dept Geol Sci, Columbia, MO 65211 USA. NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. RP Kelley, CA (reprint author), Univ Missouri, Dept Geol Sci, Columbia, MO 65211 USA. EM kelleyc@missouri.edu RI Kelley, Cheryl/K-9392-2015 NR 51 TC 7 Z9 7 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-BIOGEO JI J. Geophys. Res.-Biogeosci. PD NOV 22 PY 2006 VL 111 IS G4 AR G04012 DI 10.1029/2006JG000212 PG 8 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 110HM UT WOS:000242369100002 ER PT J AU Arvidson, RE Poulet, F Morris, RV Bibring, JP Bell, JF Squyres, SW Christensen, PR Bellucci, G Gondet, B Ehlmann, BL Farrand, WH Fergason, RL Golombek, M Griffes, JL Grotzinger, J Guinness, EA Herkenhoff, KE Johnson, JR Klingelhofer, G Langevin, Y Ming, D Seelos, K Sullivan, RJ Ward, JG Wiseman, SM Wolff, M AF Arvidson, R. E. Poulet, F. Morris, R. V. Bibring, J. -P. Bell, J. F., III Squyres, S. W. Christensen, P. R. Bellucci, G. Gondet, B. Ehlmann, B. L. Farrand, W. H. Fergason, R. L. Golombek, M. Griffes, J. L. Grotzinger, J. Guinness, E. A. Herkenhoff, K. E. Johnson, J. R. Klingelhoefer, G. Langevin, Y. Ming, D. Seelos, K. Sullivan, R. J. Ward, J. G. Wiseman, S. M. Wolff, M. TI Nature and origin of the hematite-bearing plains of Terra Meridiani based on analyses of orbital and Mars Exploration rover data sets SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID THERMAL EMISSION SPECTROMETER; OPPORTUNITY ROVER; MOSSBAUER SPECTROMETER; SPECTRAL REFLECTANCE; SURFACE-COMPOSITION; MINERAL MIXTURES; ODYSSEY MISSION; BURNS FORMATION; LANDING SITE; MINI-TES AB The similar to 5 km of traverses and observations completed by the Opportunity rover from Endurance crater to the Fruitbasket outcrop show that the Meridiani plains consist of sulfate-rich sedimentary rocks that are largely covered by poorly-sorted basaltic aeolian sands and a lag of granule-sized hematitic concretions. Orbital reflectance spectra obtained by Mars Express OMEGA over this region are dominated by pyroxene, plagioclase feldspar, crystalline hematite (i.e., concretions), and nano-phase iron oxide dust signatures, consistent with Pancam and Mini-TES observations. Mossbauer Spectrometer observations indicate more olivine than observed with the other instruments, consistent with preferential optical obscuration of olivine features in mixtures with pyroxene and dust. Orbital data covering bright plains located several kilometers to the south of the landing site expose a smaller areal abundance of hematite, more dust, and a larger areal extent of outcrop compared to plains proximal to the landing site. Low-albedo, low-thermal-inertia, windswept plains located several hundred kilometers to the south of the landing site are predicted from OMEGA data to have more hematite and fine-grained olivine grains exposed as compared to the landing site. Low calcium pyroxene dominates spectral signatures from the cratered highlands to the south of Opportunity. A regional-scale model is presented for the formation of the plains explored by Opportunity, based on a rising ground water table late in the Noachian Era that trapped and altered local materials and aeolian basaltic sands. Cessation of this aqueous process led to dominance of aeolian processes and formation of the current configuration of the plains. C1 Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Ist Nazl Astrofis, Ist Fis Spazio Interplanetario, I-00133 Rome, Italy. Univ Oxford, Sch Geog & Environm, Oxford OX1 3QY, England. Space Sci Inst, Boulder, CO 80301 USA. Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Johannes Gutenberg Univ Mainz, Inst Anorgan & Analyt Chem, D-55128 Mainz, Germany. RP Arvidson, RE (reprint author), Washington Univ, Dept Earth & Planetary Sci, Campus Box 1167,1 Brookngs Dr, St Louis, MO 63130 USA. EM arvidson@wunder.wustl.edu RI Seelos, Kimberly/F-4647-2015; Johnson, Jeffrey/F-3972-2015; OI Seelos, Kimberly/0000-0001-7236-0580; Bellucci, Giancarlo/0000-0003-0867-8679 NR 65 TC 99 Z9 100 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 22 PY 2006 VL 111 IS E12 AR E12S08 DI 10.1029/2006JE002728 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 110HU UT WOS:000242369900001 ER PT J AU Noble, SK Pieters, CM Hiroi, T Taylor, LA AF Noble, Sarah K. Pieters, Carle M. Hiroi, Takahiro Taylor, Lawrence A. TI Using the modified Gaussian model to extract quantitative data from lunar soils SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID REFLECTANCE SPECTRA; FINEST FRACTION; SPACE; SPECTROSCOPY AB [ 1] The Lunar Soil Characterization Consortium (LSCC) has examined and characterized a suite of lunar soils with a wide range of compositions and maturities. The purpose of this study is to compare the Vis/NIR spectral properties of these lunar soils with their petrologic and chemical compositions using the modified Gaussian model (MGM) to obtain quantitative data about the character of relatively weak near-infrared absorption bands. Useful compositional information can be extracted from high-quality soil spectra using the MGM. The model had some difficulty fitting absorption bands in the 2 mu m region of the lunar spectrum, but bands in the 1 and 1.2 mu m regions provided physically realistic results. The model was able to distinguish high-Ca and low-Ca pyroxenes in the LSCC suite of lunar soils in the appropriate relative abundance. In addition, unexpected insights into the nature and causes of absorption bands in lunar soils were identified. For example, at least two distinct absorption bands are required in the 1.2 mu m region of the spectrum, and neither of these bands can be attributed to plagioclase or agglutinates, but are found instead to be largely due to pyroxene. C1 Brown Univ, Providence, RI 02912 USA. Univ Tennessee, Knoxville, TN 37996 USA. RP Noble, SK (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM sarah.k.noble@nasa.gov RI Noble, Sarah/D-7614-2012 NR 36 TC 23 Z9 24 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 22 PY 2006 VL 111 IS E11 AR E11009 DI 10.1029/2006JE002721 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 110HS UT WOS:000242369700004 ER PT J AU Szwast, MA Richardson, MI Vasavada, AR AF Szwast, Mark A. Richardson, Mark I. Vasavada, Ashwin R. TI Surface dust redistribution on Mars as observed by the Mars Global Surveyor and Viking orbiters SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID THERMAL EMISSION SPECTROMETER; HUBBLE-SPACE-TELESCOPE; VARIABLE FEATURES; INTERANNUAL VARIABILITY; CAMERA; STORMS; ALBEDO; CLIMATE; TES; TEMPERATURES AB [ 1] The variation of surface dust coverage on Mars is mapped using Mars Global Surveyor (MGS) and Viking albedo data. Albedo is shown to correlate well with spectrally derived measurements of surface dust abundance and is subsequently used to gauge dust coverage. Atmospheric aerosols modify the albedo observed from orbit, complicating this analysis. However, opacity cycles are highly repeatable, and simultaneous, independent records of aerosol opacities are available to isolate their impact. The MGS albedo and imaging data contain global coverage on a daily basis, allowing the relationship between dust cover and specific meteorological events to be elucidated. The 2001 global dust storm produced the largest changes in surface dust coverage during the MGS mission. Other processes yielding significant changes include seasonal cap-edge winds, seasonally varying regional winds, local/regional dust storms, and extratropical cyclones. Dust devils and ongoing, small-scale dust lifting do not appear to significantly modify the global patterns of dust cover. Finally, we show that the apparent long-term darkening of the southern mid and high latitudes between the Viking and MGS eras is largely a consequence of the timing of image acquisition relative to global dust storms and surface dust "cleaning'' by the seasonal ice cap; it does not represent a steady decadal-scale, secular change. In fact, following the 2001 global dust storm, in late southern spring, the southern hemisphere was brighter in MGS than in Viking data. This study reveals albedo to be a dynamic, climatological variable for Mars, similar to sea-surface temperature for terrestrial meteorology and climate. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Szwast, MA (reprint author), CALTECH, Div Geol & Planetary Sci, MS 150-21, Pasadena, CA 91125 USA. EM mir@gps.caltech.edu NR 52 TC 26 Z9 26 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 22 PY 2006 VL 111 IS E11 AR E11008 DI 10.1029/2005JE002485 PG 36 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 110HS UT WOS:000242369700001 ER PT J AU Voorhies, CV AF Voorhies, C. V. TI A geomagnetic estimate of mean paleointensity SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EARTHS MAGNETIC-FIELD; CORE-MANTLE BOUNDARY; LONG-TERM VARIATIONS; SECULAR VARIATION; INTENSITY; MODEL; TIME; STATISTICS; REVERSALS; SPECTRA AB A statistical hypothesis about Earth's magnetic field is tested against paleomagnetism by combining it with the present field to estimate mean paleointensity. The estimate uses the satellite era geomagnetic multipole power spectrum R-n, which gives the mean square magnetic induction represented by spherical harmonics of degree n averaged over the sphere of radius a = 6371.2 km. The hypothesis asserts that low-degree multipole powers of the core source field, R-n(c), are distributed as chi-square with 2n + 1 degrees of freedom and theoretical expectation values {R-n(c)} = K(n + 1/2)[n(n + 1)](-1)(c/a)(2n + 4), where c is the 3480 km radius of Earth's core. The implied field is usually mainly dipolar and can be primarily axial. Amplitude K is estimated by fitting theoretical to observational spectra of degrees 1-12. The resulting calibrated expectation spectrum is summed through degree 12 to estimate expected square intensity {F-2}. This sum also estimates mean square paleointensity, averaged over geologic time as well as the sphere, in so far as the present field spectrum is a fair sample of that generated in the past by core geodynamic processes. Previously, we excluded dominant degrees 1 and 2 from the fit, but not the sum, to "predict'' mean paleointensity from the 1980 Magsat nondipole field. The new estimate fits all R-n of degrees 1-12 self-consistently and yields {F-2} = (37.3 +/- 4.3 mu T)(2). Expected paleointensity {F} is about 34.4 +/- 4.9 mu T; expected virtual axial dipole moment is about (6.51 +/- 0.94) x 10(22) Am-2. These estimates are within the range of published paleomagnetic determinations of mean paleointensity; therefore the statistical hypothesis passes this test. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Voorhies, CV (reprint author), NASA, Goddard Space Flight Ctr, Code 698, Greenbelt, MD 20771 USA. EM coerte.v.voorhies@nasa.gov RI Voorhies, Coerte/D-4672-2012 NR 38 TC 1 Z9 1 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD NOV 22 PY 2006 VL 111 IS B11 AR B11105 DI 10.1029/2005JB003874 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 110HX UT WOS:000242370200001 ER PT J AU Bhardwaj, A Elsner, RF Gladstone, GR Waite, JH Branduardi-Raymont, G Cravens, TE Ford, PG AF Bhardwaj, Anil Elsner, Ronald F. Gladstone, G. Randall Waite, J. Hunter, Jr. Branduardi-Raymont, Graziella Cravens, Thomas E. Ford, Peter G. TI Low- to middle-latitude X-ray emission from Jupiter SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID JOVIAN AURORAL ELECTRONS; IO PLASMA TORUS; ROSAT OBSERVATIONS; ATOMIC DATABASE; XMM-NEWTON; PRECIPITATION; TEMPERATURE; ATMOSPHERE; SPECTRA; PLANETS AB [1] The Chandra X-ray Observatory (CXO) observed Jupiter during the period 24-26 February 2003 for similar to 40 hours (4 Jupiter rotations), using both the spectroscopy array of the Advanced CCD Imaging Spectrometer (ACIS-S) and the imaging array of the High-Resolution Camera (HRC-I). Two ACIS-S exposures, each similar to 8.5 hours long, were separated by an HRC-I exposure of similar to 20 hours. The low- to middle- latitude nonauroral disk X-ray emission is much more spatially uniform than the auroral emission. However, the low- to middle-latitude X-ray count rate shows a small but statistically significant hour angle dependence and depends on surface magnetic field strength. In addition, the X-ray spectra from regions corresponding to 3-5 gauss and 5-7 gauss surface fields show significant differences in the energy band 1.26-1.38 keV, perhaps partly due to line emission occurring in the 3-5 gauss region but not the 5-7 gauss region. A similar correlation of surface magnetic field strength with count rate is found for the 18 December 2000 HRC-I data, at a time when solar activity was high. The low- to middle-latitude disk X-ray count rate observed by the HRC-I in the February 2003 observation is about 50% of that observed in December 2000, roughly consistent with a decrease in the solar activity index (F10.7 cm flux) by a similar amount over the same time period. The low- to middle- latitude X-ray emission does not show any oscillations similar to the similar to 45 min oscillations sometimes seen from the northern auroral zone. The temporal variation in Jupiter's nonauroral X-ray emission exhibits similarities to variations in solar X-ray flux observed by GOES and TIMED/SEE. The two ACIS-S 0.3-2.0 keV low- to middle- latitude X-ray spectra are harder than the auroral spectrum and are different from each other at energies above 0.7 keV, showing variability in Jupiter's nonauroral X-ray emission on a timescale of a day. The 0.3-2.0 keV X-ray power emitted at low to middle latitudes is 0.21 GW and 0.39 GW for the first and second ACIS-S exposures, respectively. We suggest that X-ray emission from Jupiter's disk may be largely generated by the scattering and fluorescence of solar X rays in its upper atmosphere, especially at times of high incident solar X-ray flux. However, the dependence of count rate on surface magnetic-field strength may indicate the presence of some secondary component, possibly ion precipitation from radiation belts close to the planet. C1 Vikram Sarabhai Space Ctr, Space Phys Lab, Trivandrum 695022, Kerala, India. NASA, Marshall Space Flight Ctr, Space Sci Branch, Huntsville, AL USA. SW Res Inst, San Antonio, TX USA. UCL, Mullard Space Sci Lab, Surrey, England. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. RP Bhardwaj, A (reprint author), Vikram Sarabhai Space Ctr, Space Phys Lab, Trivandrum 695022, Kerala, India. EM anil_bhardwaj@vssc.gov.in; ron.elsner@nasa.gov; randy.gladstone@swri.org; gbr@mssl.ucl.ac.uk; cravens@ku.edu; pgf@space.mit.edu OI Bhardwaj, Anil/0000-0003-1693-453X NR 43 TC 19 Z9 19 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 22 PY 2006 VL 111 IS A11 AR A11225 DI 10.1029/2006JA011792 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 110IB UT WOS:000242370600001 ER PT J AU Gutsev, GL Mochena, MD Johnson, E Bauschlicher, CW AF Gutsev, G. L. Mochena, M. D. Johnson, E. Bauschlicher, C. W., Jr. TI Dissociative and associative attachment of NO to iron clusters SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY-FUNCTIONAL CALCULATIONS; CLOSE-PACKED TRANSITION; NOBLE-METAL SURFACES; NITRIC-OXIDE; INFRARED-SPECTRA; GAS-PHASE; AB-INITIO; PHOTOELECTRON-SPECTROSCOPY; ELECTRONIC-STRUCTURE; IONIZATION ENERGIES AB Electronic and geometrical structures of iron clusters with associative (FeNO, Fe2NO, Fe3NO, Fe4NO, Fe5NO, and Fe6NO) and dissociative (OFeN, OFe2N, OFe3N, OFe4N, OFe5N, and OFe6N) attachments of NO, as well as the corresponding singly negatively and positively charged ions, are computed using density functional theory with generalized gradient corrections. Both types of isomers are found to be stable and no spontaneous dissociation was observed during the geometry optimizations. The ground states correspond to dissociative attachment of NO for all iron clusters Fe-n, except for Fe and Fe+. All of the OFenN clusters have ferrimagnetic ground states, except for OFe2N, OFe2N-, OFe4N, and OFe4N-, which prefer the ferromagnetic coupling. In the ferrimagnetic states, the excess spin density at one iron atom couples antiferromagnetically to the excess spin densities of all other iron atoms. Relative to the high-spin Fe-n ground state, the lowest energy ferrimagnetic state quenches the total magnetic moments of iron clusters by 7, which is to be compared with a reduction in the magnetic moment of one in the lowest energy ferromagnetic states. Dissociation of NO on the iron clusters has a pronounced impact on the energetics of reactions; the FenNO+CO -> FenN+CO2 channels are exothermic while the OFe6N+CO -> Fe6N+CO2 channels are nearly thermoneutral. (c) 2006 American Institute of Physics. C1 Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA. Florida A&M Univ, Inst Environm Sci, Tallahassee, FL 32307 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gutsev, GL (reprint author), Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA. EM gennady.gutsev@famu.edu NR 55 TC 22 Z9 25 U1 0 U2 13 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 21 PY 2006 VL 125 IS 19 AR 194312 DI 10.1063/1.2378831 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 107OV UT WOS:000242181800028 PM 17129108 ER PT J AU Ginoux, P Horowitz, LW Ramaswamy, V Geogdzhayev, IV Holben, BN Stenchikov, G Tie, X AF Ginoux, Paul Horowitz, Larry W. Ramaswamy, V. Geogdzhayev, Igor V. Holben, Brent N. Stenchikov, Georgiy Tie, Xuexi TI Evaluation of aerosol distribution and optical depth in the Geophysical Fluid Dynamics Laboratory coupled model CM2.1 for present climate SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; PINATUBO VOLCANIC-ERUPTION; GLOBAL 3-DIMENSIONAL MODEL; CARBONACEOUS AEROSOLS; TROPOSPHERIC AEROSOL; ATMOSPHERIC AEROSOL; RELATIVE-HUMIDITY; SAHARAN DUST; ANTHROPOGENIC SULFATE; GODDARD-INSTITUTE AB This study evaluates the strengths and weaknesses of aerosol distributions and optical depths that are used to force the GFDL coupled climate model CM2.1. The concentrations of sulfate, organic carbon, black carbon, and dust are simulated using the MOZART model (Horowitz, 2006), while sea-salt concentrations are obtained from a previous study by Haywood et al. (1999). These aerosol distributions and precalculated relative-humidity-dependent specific extinction are utilized in the CM2.1 radiative scheme to calculate the aerosol optical depth. Our evaluation of the mean values (1996-2000) of simulated aerosols is based on comparisons with long-term mean climatological data from ground-based and remote sensing observations as well as previous modeling studies. Overall, the predicted concentrations of aerosol are within a factor 2 of the observed values and have a tendency to be overestimated. Comparison with satellite data shows an agreement within 10% of global mean optical depth. This agreement masks regional differences of opposite signs in the optical depth. Essentially, the excessive optical depth from sulfate aerosols compensates for the underestimated contribution from organic and sea-salt aerosols. The largest discrepancies are over the northeastern United States (predicted optical depths are too high) and over biomass burning regions and southern oceans (predicted optical depths are too low). This analysis indicates that the aerosol properties are very sensitive to humidity, and major improvements could be achieved by properly taking into account their hygroscopic growth together with corresponding modifications of their optical properties. C1 NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Columbia Univ, NASA, GISS, New York, NY 10025 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Rutgers State Univ, Dept Environm Sci, New Brunswick, NJ 08901 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. RP Ginoux, P (reprint author), NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. EM paul.ginoux@noaa.gov; larry.horowitz@noaa.gov; v.ramaswamy@noaa.gov; igor@giss.nasa.gov; brent.n.holben@gsfc.nasa.gov; gera@envsci.rutgers.edu; xxtie@ucar.edu RI Ginoux, Paul/C-2326-2008; Georgiy, Stenchikov/J-8569-2013; Horowitz, Larry/D-8048-2014 OI Ginoux, Paul/0000-0003-3642-2988; Horowitz, Larry/0000-0002-5886-3314 NR 70 TC 48 Z9 51 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 21 PY 2006 VL 111 IS D22 AR D22210 DI 10.1029/2005JD006707 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 110HF UT WOS:000242368400001 ER PT J AU Zheng, QN Fang, GH Song, YT AF Zheng, Quanan Fang, Guohong Song, Y. Tony TI Introduction to special section: Dynamics and circulation of the Yellow, East, and South China Seas SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Editorial Material ID INDONESIAN THROUGHFLOW; SURFACE CIRCULATION; OCEAN CIRCULATION; CONTINENTAL-SHELF; NUMERICAL-MODEL; KUROSHIO; COAST; NORTHEAST; TRANSPORT; CURRENTS C1 Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. State Ocean Adm, Inst Oceanog 1, Key Lab Marine Sci & Numer Modeling, Qingdao 266061, Shandong, Peoples R China. RP Zheng, QN (reprint author), Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. EM quanan@atmos.umd.edu RI Zheng, Quanan/F-9025-2010 NR 66 TC 11 Z9 11 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD NOV 21 PY 2006 VL 111 IS C11 AR C11S01 DI 10.1029/2005JC003261 PG 5 WC Oceanography SC Oceanography GA 110HP UT WOS:000242369400002 ER PT J AU Trujillo, I Feulner, G Goranova, Y Hopp, U Longhetti, M Saracco, P Bender, R Braito, V Della Ceca, R Drory, N Mannucci, F Severgnini, P AF Trujillo, I. Feulner, G. Goranova, Y. Hopp, U. Longhetti, M. Saracco, P. Bender, R. Braito, V. Della Ceca, R. Drory, N. Mannucci, F. Severgnini, P. TI Extremely compact massive galaxies at z similar to 1.4 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : elliptical and lenticular, cD; galaxies : evolution; galaxies : formation; galaxies : fundamental parameters; galaxies : high-redshift; galaxies : structure ID INFRARED CLUSTER SURVEY; DIGITAL SKY SURVEY; ELLIPTIC GALAXIES; LUMINOSITY-SIZE; DEEP-FIELD; STELLAR POPULATIONS; FORMATION HISTORY; EVOLVED GALAXIES; FORS DEEP; K-BAND AB The optical rest-frame sizes of 10 of the most massive (similar to 5 x 10(11) h(70)(-2) M circle dot) galaxies found in the near-infrared MUNICS survey at 1.2 < z < 1.7 are analysed. Sizes are estimated in both the J and K' filters. These massive galaxies are at least a factor of 4(-)(1.0)(+)(1.9) (+/- 1 alpha) smaller in the rest-frame V-band than local counterparts of the same stellar mass. Consequently, the stellar mass density of these objects is ( at least) 60 times larger than that of massive ellipticals today. Although the stellar populations of these objects are passively fading, their structural properties are rapidly changing since that redshift. This observational fact disagrees with a scenario where the more massive and passive galaxies are fully assembled at z similar to 1.4 (i.e. a monolithic scenario) and points towards a dry merger scenario as the responsible mechanism for the subsequent evolution of these galaxies. C1 Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England. Univ Sternwarte Munchen, D-81679 Munich, Germany. Max Planck Inst Extraterr Phys, D-85748 Garching, Germany. Potsdam Inst Klimafolgenforsch, D-14412 Potsdam, Germany. Osserv Astron Brera, INAF, I-20121 Milan, Italy. NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. Univ Texas, Austin, TX 78712 USA. CNR, Ist Radioastron, I-50125 Florence, Italy. RP Trujillo, I (reprint author), Univ Nottingham, Sch Phys & Astron, Univ Pk, Nottingham NG7 2RD, England. EM ignacio.trujillo@nottingham.ac.uk RI Feulner, Georg/A-1933-2011; OI Feulner, Georg/0000-0001-9215-5517; mannucci, filippo/0000-0002-4803-2381; Severgnini, Paola/0000-0001-5619-5896; Della Ceca, Roberto/0000-0001-7551-2252; Longhetti, Marcella/0000-0002-6142-4822; Saracco, Paolo/0000-0003-3959-2595; Braito, Valentina/0000-0002-2629-4989 NR 50 TC 151 Z9 151 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD NOV 21 PY 2006 VL 373 IS 1 BP L36 EP L40 DI 10.1111/j.1745-3933.2006.00238.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 103MV UT WOS:000241891700008 ER PT J AU Beckmann, V Soldi, S Shrader, CR Gehrels, N Produit, N AF Beckmann, V. Soldi, S. Shrader, C. R. Gehrels, N. Produit, N. TI The hard X-ray 20-40 keV AGN luminosity function SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : Seyfert; gamma rays : observations; surveys; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; ROSAT DEEP SURVEY; XMM-NEWTON; INTEGRAL OBSERVATIONS; COSMOLOGICAL EVOLUTION; BEPPOSAX OBSERVATIONS; OPTICAL SPECTROSCOPY; LOCKMAN FIELD; SPECTRUM; CHANDRA AB We have compiled a complete extragalactic sample based on similar to 25,000 deg(2) to a limiting flux of 3; 10(-11) ergs cm(-2) s(-1) (similar to 7000 deg(2) to a flux limit of 10(-11) ergs cm(-2) s(-1)) in the 20-40 keV band with INTEGRAL. We have constructed a detailed exposure map to compensate for effects of nonuniform exposure. The flux-number relation is best described by a power law with a slope of alpha = 1.66 +/- 0.11. The integration of the cumulative flux per unit area leads to f(20-40) (keV) = 2.6 x 10(-10) ergs cm(-2) s(-1) sr(-1), which is about 1% of the known 20-40 keV X-ray background. We present the first luminosity function of AGNs in the 20-40 keV energy range, based on 38 extragalactic objects detected by the imager IBIS-ISGRI on board INTEGRAL. The luminosity function shows a smoothly connected double-power-law form with an index of gamma(1) = 0.8 below and gamma(2) = 2.1 above the turnover luminosity of L-* = 2.4 x 10(43) ergs s(-1). The emissivity of all INTEGRAL AGNs per unit volume is W20-40 (keV)(> 10(41) ergs s(-1)) = 2.8 x 10(38) ergs s(-1) h(70)(3) Mpc(-3). These results are consistent with those derived in the 2-20 keV energy band and do not show a significant contribution by Compton-thick objects. Because the sample used in this study is truly local (z = 0.022), only limited conclusions can be drawn for the evolution of AGNs in this energy band. C1 NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland. Observ Geneva, CH-1290 Sauverny, Switzerland. Univ Space Res Assoc, Columbia, MD 21044 USA. RP Beckmann, V (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Code 661, Greenbelt, MD 20771 USA. EM beckmann@milkyway.gsfc.nasa.gova RI Gehrels, Neil/D-2971-2012; OI Produit, Nicolas/0000-0001-7138-7677 NR 58 TC 40 Z9 40 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 126 EP 135 DI 10.1086/507510 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700012 ER PT J AU Sambruna, RM Gliozzi, M Tavecchio, F Maraschi, L Foschini, L AF Sambruna, Rita M. Gliozzi, Mario Tavecchio, F. Maraschi, L. Foschini, Luigi TI The jet-disk connection in AGNs: Chandra and XMM-Newton observations of three powerful radio-loud quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : jets; quasars : individual (0723+679,1136-135,1150+497) ID ACTIVE GALACTIC NUCLEI; SPECTRAL ENERGY-DISTRIBUTIONS; HUBBLE-SPACE-TELESCOPE; X-RAY-SPECTRA; TIMING-EXPLORER; CENTRAL-ENGINE; EMISSION; GALAXIES; BLAZARS; LUMINOSITY AB The connection between the accretion process that powers AGNs and the formation of jets is still poorly understood. Here we tackle this issue using new, deep Chandra and XMM-Newton observations of the cores of three powerful radio-loud quasars, 1136-135, 1150+497 (Chandra), and 0723+679 (XMM-Newton), in the redshift range z = 0.3-0.8. These sources are known from our previous Chandra snapshot survey to have kiloparsec-scale X-ray jets. In 1136-135 and 1150+ 497, evidence is found for the presence of diffuse thermal X-ray emission around the cores, on scales of 40-50 kpc and with luminosity L(0.3-2 keV) similar to 10(43) ergs s(-1), suggesting thermal emission from the host galaxy or a galaxy group. The X-ray continua of the cores in the three sources are described by an upwardcurved (concave) broken power law, with photon indices Gamma(soft) similar to 1.8-2.1 and Gamma(hard) similar to 1: 7 below and above approximate to 2 keV, respectively. There is evidence for an unresolved Fe K alpha line with EW similar to 70 eV in the three quasars. The spectral energy distributions of the sources can be well described by a mix of jet and disk emission, with the jet dominating the radio and hard X-rays (via synchrotron and external Compton radiation) and the disk dominating the optical/UV through soft X-rays. A comparison of the kiloparsec- scale with the parsec-scale jet powers shows that the two agree within a factor of 2, confirming previous findings for gamma-ray blazars. This suggests that the power channeled into the jet is stable on timescales of the order of 10(4)-10(5) yr and that a negligible fraction of the kinetic power of the jet is dissipiated along its path from the innermost regions of the AGN to the hundreds of kiloparsec scales. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. George Mason Univ, Dept Phys & Astron, Fairfax, VA 22030 USA. Sch Computat Sci, Fairfax, VA 22030 USA. OAB, INAF, I-20121 Milan, Italy. IASF Bologna, INAF, I-40129 Bologna, Italy. RP Sambruna, RM (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Foschini, Luigi/H-3833-2012 OI Foschini, Luigi/0000-0001-8678-0324 NR 56 TC 41 Z9 41 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 146 EP 156 DI 10.1086/507420 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700014 ER PT J AU Bendo, GJ Dale, DA Draine, BT Engelbracht, CW Kennicutt, RC Calzetti, D Gordon, KD Helou, G Hollenbach, D Li, AG Murphy, EJ Prescott, MKM Smith, JDT AF Bendo, George J. Dale, Daniel A. Draine, Bruce T. Engelbracht, Charles W. Kennicutt, Robert C., Jr. Calzetti, Daniela Gordon, Karl D. Helou, George Hollenbach, David Li, Aigen Murphy, Eric J. Prescott, Moire K. M. Smith, John-David T. TI The spectral energy distribution of dust emission in the edge-on spiral galaxy NGC 4631 as seen with Spitzer and the James Clerk Maxwell telescope SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 4631); galaxies : ISM; infrared : galaxies ID MULTIBAND IMAGING PHOTOMETER; LOW-METALLICITY ENVIRONMENTS; CLERK-MAXWELL-TELESCOPE; INFRARED ARRAY CAMERA; STAR-FORMING GALAXIES; NEARBY GALAXIES; COLD DUST; SPACE-TELESCOPE; PANCHROMATIC VIEW; ISM PROPERTIES AB We explore variations in dust emission within the edge- on Sd spiral galaxy NGC 4631 using 3.6Y160 mu m Spitzer Space Telescope data and 450Y850 mu m JCMT data with the goals of understanding the relation between PAHs and dust emission, studying the variations in the colors of the dust emission, and searching for possible excess submillimeter emission compared to what is expected from dust models extrapolated from far- infrared wavelengths. The 8 mu m PAH emission correlates best with 24 mu m hot dust emission on 1.7 kpc scales, but the relation breaks down on 650 pc scales, possibly because of differences in the mean free paths between photons that excite the PAHs and photons that heat the dust and possibly because the PAHs are destroyed by the hard radiation fields within some star formation regions. The ratio of 8 mu m PAH emission to 160 mu m cool dust emission appears to vary as a function of radius. The 70 mu m/ 160 mu m and 160 mu m/ 450 mu m flux density ratios are remarkably constant even though the surface brightnesses vary by factors of 25, which suggests that the emission is from dust heated by a nearly uniform radiation field. Globally, we find an excess of 850Y1230 mu m emission relative to what would be predicted by dust models. The 850 mu m excess is highest in regions with low 160 mu m surface brightnesses, although the magnitude depends on the model fit to the data. We rule out variable emissivity functions or similar to 4 K dust as the possible origins of this 850 mu m emission, but we do discuss the other possible mechanisms that could produce the emission. C1 Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2AZ, England. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Natl Res Council Canada, Herzberg Inst Astrophys, Canadian Astron Data Ctr, Ottawa, ON K1A 0R6, Canada. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Space Telescope Sci Inst, Baltimore, MD 21218 USA. CALTECH, Pasadena, CA 91101 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. RP Bendo, GJ (reprint author), Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, Prince Consort Rd, London SW7 2AZ, England. EM g.bendo@imperial.ac.uk OI Draine, Bruce/0000-0002-0846-936X NR 51 TC 65 Z9 65 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 283 EP 305 DI 10.1086/508057 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700027 ER PT J AU Brown, TM Smith, E Ferguson, HC Rich, RM Guhathakurta, P Renzini, A Sweigart, AV Kimble, RA AF Brown, Thomas M. Smith, Ed Ferguson, Henry C. Rich, R. Michael Guhathakurta, Puragra Renzini, Alvio Sweigart, Allen V. Kimble, Randy A. TI The detailed star formation history in the spheroid, outer disk, and tidal stream of the Andromeda galaxy SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : evolution; galaxies : halos; galaxies : individual (M31); galaxies : spiral; galaxies : stellar content ID HUBBLE-SPACE-TELESCOPE; COLD DARK-MATTER; GLOBULAR-CLUSTER SYSTEM; GIANT SOUTHERN STREAM; MAIN-SEQUENCE PHOTOMETRY; I-BAND OBSERVATIONS; METAL-POOR STARS; RR LYRAE STARS; METALLICITY DISTRIBUTION; MILKY-WAY AB Using HSTACS, we have obtained deep optical images reaching stars well below the oldest main-sequence turnoff in the spheroid, tidal stream, and outer disk of Andromeda. We have reconstructed the star formation history in these fields by comparing their color-magnitude diagrams to a grid of isochrones calibrated to Galactic globular clusters observed in the same bands. Each field exhibits an extended star formation history, with many stars younger than 10 Gyr but few younger than 4 Gyr. Considered together, the star counts, kinematics, and population characteristics of the spheroid argue against some explanations for its intermediate-age, metal-rich population, such as a significant contribution from stars residing in the disk or a chance intersection with the stream's orbit. Instead, it is likely that this population is intrinsic to the inner spheroid, whose highly disturbed structure is clearly distinct from the pressure-supported metal-poor halo that dominates farther from the galaxy's center. The stream and spheroid populations are similar, but not identical, with the stream's mean age being similar to 1 Gyr younger; this similarity suggests that the inner spheroid is largely polluted by material stripped from either the stream's progenitor or similar objects. The disk population is considerably younger and more metal-rich than the stream and spheroid populations, but not as young as the thin-disk population of the solar neighborhood; instead, the outer disk of Andromeda is dominated by stars of age 4-8 Gyr, resembling the Milky Way's thick disk. The disk data are inconsistent with a population dominated by ages older than 10 Gyr and in fact do not require any stars older than 10 Gyr. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Calif Los Angeles, Div Astron, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Osserv Astron Padova, I-35122 Padua, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Brown, TM (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM tbrown@stsci.edu; edsmith@stsci.edu; ferguson@stsci.edu; rmr@astro.ucla.edu; raja@ucolick.org; arenzini@pd.astro.it; allen.v.sweigart@nasa.gov; randy.a.kimble@nasa.gov RI Kimble, Randy/D-5317-2012 NR 126 TC 108 Z9 108 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 323 EP 353 DI 10.1086/508015 PN 1 PG 31 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700030 ER PT J AU Weisskopf, MC Swartz, DA Carraminana, A Carrasco, L Kaplan, DL Becker, W Elsner, RF Kanbach, G O'Dell, SL Tennant, AF AF Weisskopf, Martin C. Swartz, Douglas A. Carraminana, Alberto Carrasco, Luis Kaplan, David L. Becker, Werner Elsner, Ronald F. Kanbach, Gottfried O'Dell, Stephen L. Tennant, Allyn F. TI A search for the X-ray counterpart of the unidentified gamma-ray source 3EG J2020+4017 (2CG078+2) SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (SNR 78.2+2.1=gamma-Cygni SNR); supernova remnants; X-rays : individual (3EG J2020+4017) ID CYGNI SUPERNOVA REMNANT; MEDIUM-SENSITIVITY SURVEY; HIGH-ENERGY; EGRET SOURCES; COSMIC-RAY; GALACTIC PLANE; GEMINGA PULSAR; COMPTON EMISSION; MILKY-WAY; RADIATION AB We report observations with the Chandra X-Ray Observatory of a field in the alpha-Cygni supernova remnant (SNR 78.2+2.1) centered on the cataloged location of the unidentified, bright gamma-ray source 3EG J2020+4017. In this search for an X-ray counterpart to the gamma-ray source, we detected 30 X-ray sources. Of these, we found 17 strong-candidate counterparts in optical (visible through near-infrared) cataloged and an additional three through our optical observations. Based on colors and (for several objects) optical spectra, nearly all the optically identified objects appear to be reddened main-sequence stars: none of the X-ray sources with an optical counterpart is a plausible X-ray counterpart to 3EG J2020+4017-if that gamma-ray source is a spin-powered pulsar. Many of the 10 X-ray sources lacking optical counterparts are likely (extragalactic) active galactic nuclei, based on the sky density of such sources. Although one of the 10 optically unidentified X-ray sources could be the gamma-ray source, there is no auxiliary evidence supporting such an identification. C1 NASA, George C Marshall Space Flight Ctr, Space Sci Off, Huntsville, AL 35812 USA. NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Space Sci Off, Huntsville, AL 35812 USA. Inst Nacl Astrofis Opt & Electr, Puebla 72840, Mexico. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. RP Weisskopf, MC (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Off, VP62, Huntsville, AL 35812 USA. NR 71 TC 10 Z9 10 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 387 EP 400 DI 10.1086/508339 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700035 ER PT J AU Hora, JL Latter, WB Smith, HA Marengo, M AF Hora, Joseph L. Latter, William B. Smith, Howard A. Marengo, Massimo TI Infrared observations of the Helix planetary nebula SO ASTROPHYSICAL JOURNAL LA English DT Article DE planetary nebulae : general; planetary nebulae : individual (Helix nebula, NGC 7293) ID SPITZER-SPACE-TELESCOPE; ARRAY CAMERA IRAC; YOUNG STELLAR OBJECTS; EMISSION; KNOTS; REGIONS; CALIBRATION; NGC-7293; GLOBULES; DUST AB We have mapped the Helix (NGC 7293) planetary nebula (PN) with the IRAC instrument on the Spitzer Space Telescope. The Helix is one of the closest bright PNs and therefore provides an opportunity to resolve the small-scale structure in the nebula. The emission from this PN in the 5.8 and 8 mu m IRAC bands is dominated by the pure rotational lines of molecular hydrogen, with a smaller contribution from forbidden line emission such as [Ar III] in the ionized region. The IRAC images resolve the "cometary knots,'' which have been previously studied in this PN. The "tails'' of the knots and the radial rays extending into the outer regions of the PN are seen in emission in the IRAC bands. IRS spectra on the main ring and the emission in the IRAC bands are consistent with shock-excited H-2 models, with a small (similar to 10%) component from photodissociation regions. In the northeast arc, the H-2 emission is located in a shell outside the H-2 emission. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, NASA, Herschel Sci Ctr, Pasadena, CA 91125 USA. RP Hora, JL (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS 65, Cambridge, MA 02138 USA. OI Hora, Joseph/0000-0002-5599-4650 NR 37 TC 39 Z9 39 U1 0 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 426 EP 441 DI 10.1086/507944 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700037 ER PT J AU Wisniewski, JP Bjorkman, KS AF Wisniewski, J. P. Bjorkman, K. S. TI The role of evolutionary age and metallicity in the formation of classical be circumstellar disks. I. New candidate be stars in the LMC, SMC, and milky way SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter galaxies : clusters : individual (Bruck 60, Bruck 107, HW 43, LH 72, NGC 371, NGC 456, NGC 458, NGC 460, NGC 465, NGC 1850, NGC 1858, NGC 1955, NGC 2027, NGC 2186, NGC 2383, NGC 2439); Magellanic Clouds; stars : emission-line, Be; techniques : photometric ID LARGE-MAGELLANIC-CLOUD; CLUSTER NGC 330; COLOR-MAGNITUDE DIAGRAMS; INITIAL MASS FUNCTION; MAIN-SEQUENCE STARS; STELLAR EVOLUTION; CCD PHOTOMETRY; OB ASSOCIATIONS; YOUNG CLUSTERS; UBV PHOTOMETRY AB We present B, V, R, and H alpha photometry of eight clusters in the Small Magellanic Cloud, five in the Large Magellanic Cloud, and three Galactic clusters and use two-color diagrams (2-CDs) to identify candidate Be star populations in these clusters. We find evidence that the Be phenomenon is enhanced in low-metallicity environments, based on the observed fractional early-type candidate Be star content of clusters of age 10-25 Myr. Numerous candidate Be stars of spectral types B0-B5 were identified in clusters of age 5-8 Myr, challenging the suggestion of Fabregat & Torrejon that classical Be stars should only be found in clusters at least 10Myr old. These results suggest that a significant number of B-type stars must emerge onto the zero-age main sequence as rapid rotators. We also detect an enhancement in the fractional content of early-type candidate Be stars in clusters of age 10-25 Myr, suggesting that the Be phenomenon does become more prevalent with evolutionary age. We briefly discuss the mechanisms that might contribute to such an evolutionary effect. A discussion of the limitations of using the 2-CD technique to investigate the role evolutionary age and/or metallicity play in the development of the Be phenomenon is offered, and we provide evidence that other B-type objects of very different nature, such as candidate Herbig Ae/Be stars, may contaminate the claimed detections of Be stars via 2-CDs. C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Univ Toledo, Ritter Observ, Toledo, OH 43606 USA. Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. RP Wisniewski, JP (reprint author), NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Code 667,Bldg 21, Greenbelt, MD 20771 USA. EM jwisnie@milkyway.gsfc.nasa.gov; karen@physics.utoledo.edu NR 75 TC 57 Z9 57 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 458 EP 471 DI 10.1086/507260 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700039 ER PT J AU Cenko, SB Kasliwal, M Harrison, FA Pal'shin, V Frail, DA Cameron, PB Berger, E Fox, DB Gal-Yam, A Kulkarni, SR Moon, DS Nakar, E Ofek, EO Penprase, BE Price, PA Sari, R Schmidt, BP Soderberg, AM Aptekar, R Frederiks, D Golenetskii, S Burrows, DN Chevalier, RA Gehrels, N McCarthy, PJ Nousek, JA Piran, T AF Cenko, S. B. Kasliwal, M. Harrison, F. A. Pal'shin, V. Frail, D. A. Cameron, P. B. Berger, E. Fox, D. B. Gal-Yam, A. Kulkarni, S. R. Moon, D. -S. Nakar, E. Ofek, E. O. Penprase, B. E. Price, P. A. Sari, R. Schmidt, B. P. Soderberg, A. M. Aptekar, R. Frederiks, D. Golenetskii, S. Burrows, D. N. Chevalier, R. A. Gehrels, N. McCarthy, P. J. Nousek, J. A. Piran, T. TI Multiwavelength observations of GRB 050820A: An exceptionally energetic event followed from start to finish SO ASTROPHYSICAL JOURNAL LA English DT Review DE gamma rays : bursts; X-rays : individual (GRB 050820A) ID GAMMA-RAY-BURST; EARLY OPTICAL AFTERGLOW; LIGHT CURVES; THEORETICAL IMPLICATIONS; BATSE OBSERVATIONS; FIREBALL MODEL; PEAK ENERGY; EMISSION; BRIGHT; TELESCOPE AB We present observations of the unusually bright and long gamma-ray burst GRB 050820A, one of the best sampled broadband data sets in the Swift era. The gamma-ray light curve is marked by a soft precursor pulse some 200 s before the main event; the lack of any intervening emission suggests that it is due to a physical mechanism distinct from the GRB itself. The large time lag between the precursor and the main emission enabled simultaneous observations in the gamma-ray, X-ray, and optical bandpasses, something only achieved for a handful of events to date. While the contemporaneous X-rays are the low-energy tail of the prompt emission, the optical does not directly track the gamma-ray flux. Instead, the early-time optical data appear consistent with the forward shock synchrotron peak passing through the optical and are therefore likely the beginning of the afterglow. On hour timescales after the burst, the X-ray and optical light curves are inconsistent with an adiabatic expansion of the shock into the surrounding region, but rather indicate that there is a period of energy injection. Observations at late times allow us to constrain the collimation angle of the relativistic outflow to 6.degrees 8 less than or similar to theta less than or similar to 9.degrees 3. Our estimates of both the kinetic energy of the afterglow (E-KE = 5.2(-4.1)(+7.9) x 10(51) ergs) and the prompt gamma-ray energy release (E-KE = 7.5(-4.1)(+7.9) x 10(51) ergs) make GRB 050820A one of the most energetic events for which such values could be determined. C1 CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Natl Radio Astron Observ, Socorro, NM 87801 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Pomona Coll, Dept Phys & Astron, Claremont, CA 91711 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. RP Cenko, SB (reprint author), CALTECH, Space Radiat Lab, MS 220-47, Pasadena, CA 91125 USA. RI Gehrels, Neil/D-2971-2012; Frederiks, Dmitry/C-7612-2014; Pal'shin, Valentin/F-3973-2014; Aptekar, Raphail/B-3456-2015; Golenetskii, Sergey/B-3818-2015; OI Frederiks, Dmitry/0000-0002-1153-6340; Schmidt, Brian/0000-0001-6589-1287; Schmidt, Brian/0000-0002-8538-9195 NR 112 TC 76 Z9 76 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 490 EP 506 DI 10.1086/508149 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700042 ER PT J AU Bhattacharyya, S Strohmayer, TE Swank, JH Markwardt, CB AF Bhattacharyya, Sudip Strohmayer, Tod E. Swank, Jean H. Markwardt, Craig B. TI RXTE observations of 1A 1744-361: Correlated spectral and timing behavior SO ASTROPHYSICAL JOURNAL LA English DT Article DE methods : data analysis; stars : neutron; techniques : miscellaneous; techniques : spectroscopic; X-rays : binaries; X-rays : individual (1A 1744-361) ID X-RAY BINARIES; QUASI-PERIODIC OSCILLATION; NEUTRON-STAR; ABSORPTION FEATURES; SPIN FREQUENCY; GALACTIC BULGE; XMM-NEWTON; DISCOVERY; EMISSION; HZ AB We analyze Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) data of the transient low-mass X-ray binary (LMXB) system 1A 1744-361. We explore the X-ray intensity and spectral evolution of the source, perform timing analysis, and find that 1A 1744-361 shows "atoll'' behavior during the outbursts. The color-color diagram indicates that this LMXB was observed in a low-intensity, spectrally hard (low-hard) state and in a high-intensity "banana'' state. The low-hard state shows a horizontal pattern in the color-color diagram, and the previously reported "dipper QPO'' appears only during this state. We also perform energy spectral analyses, and report the first detection of a broad iron emission line and an iron absorption edge from 1A 1744-361. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Explorat Universe Div, Greenbelt, MD 20771 USA. RP Bhattacharyya, S (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM sudip@milkyway.gsfc.nasa.gov; stroh@clarence.gsfc.nasa.gov; swank@milkyway.gsfc.nasa.gov; craigm@milkyway.gsfc.nasa.gov RI Swank, Jean/F-2693-2012 NR 38 TC 8 Z9 8 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 603 EP 609 DI 10.1086/507786 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700054 ER PT J AU Bode, MF O'Brien, TJ Osborne, JP Page, KL Senziani, F Skinner, GK Starrfield, S Ness, JU Drake, JJ Schwarz, G Beardmore, AP Darnley, MJ Eyres, SPS Evans, A Gehrels, N Goad, MR Jean, P Krautter, J Novara, G AF Bode, M. F. O'Brien, T. J. Osborne, J. P. Page, K. L. Senziani, F. Skinner, G. K. Starrfield, S. Ness, J. -U. Drake, J. J. Schwarz, G. Beardmore, A. P. Darnley, M. J. Eyres, S. P. S. Evans, A. Gehrels, N. Goad, M. R. Jean, P. Krautter, J. Novara, G. TI Swift observations of the 2006 outburst of the recurrent nova RS Ophiuchi. I. Early X-ray emission from the shocked ejecta and red giant wind SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; binaries : symbiotic; novae, cataclysmic variables; stars : individual (RS Ophiuchi); supernovae : general; white dwarfs ID SYMBIOTIC STARS; AM-HERCULIS; MODELS; SPECTROSCOPY; TELESCOPE; REMNANTS; SPECTRA; MISSION; SYSTEMS; WAVE AB RS Ophiuchi began its latest outburst on 2006 February 12. Previous outbursts have indicated that high-velocity ejecta interact with a preexisting red giant wind, setting up shock systems analogous to those seen in supernova remnants. However, in the previous outburst in 1985, X-ray observations did not commence until 55 days after the initial explosion. Here we report on Swift observations covering the first month of the 2006 outburst with the Burst Alert Telescope (BAT) and X-Ray Telescope (XRT) instruments. RS Oph was clearly detected in the BAT 14-25 keV band from t = 0 to t similar to 6 days. XRT observations from 0.3 to 10 keV started 3.17 days after outburst. The rapidly evolving XRT spectra clearly show the presence of both line and continuum emission, which can be fitted by thermal emission from hot gas whose characteristic temperature, overlying absorbing column (N-H)(W), and resulting unabsorbed total flux decline monotonically after the first few days. Derived shock velocities are in good agreement with those found from observations at other wavelengths. Similarly, (N-H)(W) is in accord with that expected from the red giant wind ahead of the forward shock. We confirm the basic models of the 1985 outburst and conclude that standard phase I remnant evolution terminated by t similar to 6 days and the remnant then rapidly evolved to display behavior characteristic of phase III. Around t = 26 days, however, a new, luminous, and highly variable soft X-ray source began to appear, whose origin will be explored in a subsequent paper. C1 Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. Univ Manchester, Jodrell Bank Observ, Sch Phys & Astron, Macclesfield SK11 9DL, Cheshire, England. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Ist Astrofis Spaziale & Fis Cosm, INAF, I-20133 Milan, Italy. Univ Toulouse 3, F-31062 Toulouse, France. Univ Pavia, Dipartimento Fis Nucl & Teor, I-27100 Pavia, Italy. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. W Chester Univ, Dept Geol & Astron, Chester, PA 19383 USA. Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England. Univ Keele, Astron Grp, Sch Phys & Geog Sci, Keele ST5 5BG, Staffs, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Konigstuhl, Landessternwarte, D-69117 Heidelberg, Germany. RP Bode, MF (reprint author), Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. EM mfb@astro.livjm.ac.uk; tob@jb.man.ac.uk; julo@star.le.ac.uk; kpa@star.le.ac.uk; senziani@lambrate.inaf.it; skinner@cesr.fr; sumner.starrfield@asu.edu; jan-uwe.ness@asu.edu; jdrake@cfa.harvard.edu; gschwarz@as.arizona.edu; apb@star.le.ac.uk; mjd@astro.livjm.ac.uk; spseyres@uclan.ac.uk; ae@astro.keele.ac.uk; gehrels@milkyway.gsfc.nasa.gov; mrg@star.le.ac.uk; jean@cesr.fr; jkrautte@lsw.uni-heidelberg.de; novara@iasf-milano.inaf.it RI Gehrels, Neil/D-2971-2012 NR 38 TC 116 Z9 116 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 629 EP 635 DI 10.1086/507980 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700056 ER PT J AU Stothers, RB AF Stothers, Richard B. TI A new explanation of the Blazhko effect in RR Lyrae stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : interiors; stars : magnetic fields; stars : oscillations; stars : variables : other; turbulence ID PERIOD CHANGES; MAGNETIC-FIELDS; PULSATING STARS; MACHO PROJECT; FREQUENCY-ANALYSIS; HORIZONTAL-BRANCH; GLOBULAR-CLUSTERS; CONVECTIVE MODEL; NONRADIAL MODES; DYNAMO ACTION AB An interpretation of the modulating Blazhko effect in RR Lyrae stars is presented here, in which turbulent convection inside the hydrogen and helium ionization zones becomes cyclically weakened and strengthened owing to the presence of a transient magnetic field that is generated in situ by either a turbulent or a rotational dynamo mechanism. Successful predictions, both qualitative and quantitative, are made for the small changes of the primary pulsation period, the fluctuations of light and velocity amplitudes, the slow periodicity and irregularity of the Blazhko cycles, the restricted ranges of effective temperature for the RRab and RRc Blazhko variables, and the complex correlations between the primary period change, amplitude change, and mean effective temperature. Characteristic features of the predicted light and velocity curves at high and low amplitudes, even though they are based on radiative stellar models, agree well with the observed features, for the most part. The present theory of the Blazhko effect is simple enough that it does not require any basic change in our current understanding of RRab and RRc stars as being purely fundamental-mode and first-overtone radial pulsators. It also accounts naturally for the observed fact that hotter and cooler classes of periodic variable stars do not exhibit the Blazhko effect. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Stothers, RB (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. NR 88 TC 52 Z9 53 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 643 EP 649 DI 10.1086/508135 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700058 ER PT J AU Ragland, S Traub, WA Berger, JP Danchi, WC Monnier, JD Willson, LA Carleton, NP Lacasse, MG Millan-Gabet, R Pedretti, E Schloerb, FP Cotton, WD Townes, CH Brewer, M Haguenauer, P Kern, P Labeye, P Malbet, F Malin, D Pearlman, M Perraut, K Souccar, K Wallace, G AF Ragland, S. Traub, W. A. Berger, J. -P. Danchi, W. C. Monnier, J. D. Willson, L. A. Carleton, N. P. Lacasse, M. G. Millan-Gabet, R. Pedretti, E. Schloerb, F. P. Cotton, W. D. Townes, C. H. Brewer, M. Haguenauer, P. Kern, P. Labeye, P. Malbet, F. Malin, D. Pearlman, M. Perraut, K. Souccar, K. Wallace, G. TI First surface-resolved results with the infrared optical telescope array imaging interferometer: Detection of asymmetries in asymptotic giant branch stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; stars : AGB and post-AGB; stars : imaging; stars : spots; surveys; techniques : interferometric ID ANGULAR SIZE MEASUREMENTS; MIRA VARIABLE-STARS; BIPOLAR PREPLANETARY NEBULAE; HUBBLE-SPACE-TELESCOPE; MASS-LOSS RATES; EFFECTIVE TEMPERATURES; SIO MASERS; SPECKLE-MASKING; RESOLUTION OBSERVATIONS; OBSERVATIONAL EVIDENCE AB We have measured nonzero closure phases for about 29% of our sample of 56 nearby asymptotic giant branch (AGB) stars, using the three-telescope Infrared Optical Telescope Array (IOTA) interferometer at near-infrared wavelengths (H band) and with angular resolutions in the range 5-10 mas. These nonzero closure phases can only be generated by asymmetric brightness distributions of the target stars or their surroundings. We discuss how these results were obtained and how they might be interpreted in terms of structures on or near the target stars. We also report measured angular sizes and hypothesize that most Mira stars would show detectable asymmetry if observed with adequate angular resolution. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Jet Prop Lab, Pasadena, CA 91109 USA. Lab Astrophys Grenoble, F-38400 St Martin Dheres, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50014 USA. CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94725 USA. ALCATEL Space Ind, F-06322 Cannes, France. CEA Grenoble, LETI, F-38054 Grenoble 9, France. RP Ragland, S (reprint author), Calif Assoc Res Astron, 65-1120 Mamalahoa Highway, Kamuela, HI 96743 USA. EM sragland@keck.hawaii.edu NR 82 TC 54 Z9 54 U1 0 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 650 EP 660 DI 10.1086/507453 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700059 ER PT J AU Masset, FS D'Angelo, G Kley, W AF Masset, F. S. D'Angelo, G. Kley, W. TI On the migration of protogiant solid cores SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; hydrodynamics; methods : numerical; planetary systems : formation; planetary systems : protoplanetary disks ID DIFFERENTIALLY ROTATING-DISKS; EULERIAN TRANSPORT ALGORITHM; ORBITAL COROTATION TORQUE; FORMING JOVIAN PLANETS; LOW-MASS PROTOPLANETS; GIANT PLANETS; SOLAR NEBULA; LAYERED ACCRETION; TIDAL INTERACTION; MAGNETIZED DISKS AB The increase of computational resources has recently allowed high-resolution, three-dimensional calculations of planets embedded in gaseous protoplanetary disks. They provide estimates of the planet migration timescale that can be compared to analytical predictions. While these predictions can result in extremely short migration timescales for cores of a few Earth masses, recent numerical calculations have given an unexpected outcome: the torque acting on planets with masses between 5 and 20 M-circle plus is considerably smaller than the analytic, linear estimate. These findings motivated the present work, which investigates existence and origin of this discrepancy or "offset,'' as we shall call it, by means of two- and three-dimensional numerical calculations. We show that the offset is indeed physical and arises from the co-orbital corotation torque, since (1) it scales with the disk vortensity gradient, (2) its asymptotic value depends on the disk viscosity, (3) it is associated to an excess of the horseshoe zone width. We show that the offset corresponds to the onset of nonlinearities of the flow around the planet, which alter the streamline topology as the planet mass increases: at low mass the flow nonlinearities are confined to the planet's Bondi sphere, whereas at larger mass the streamlines display a classical picture reminiscent of the restricted three-body problem, with a prograde circumplanetary disk inside a "Roche lobe.'' This behavior is of particular importance for the subcritical solid cores (M <= 15 M-circle plus) in thin (H/r less than or similar to 0.06) protoplanetary disks. Their migration could be significantly slowed down, or reversed, in disks with shallow surface density profiles. C1 Univ Paris 07, CNRS, CEA, AIM UMR 7158,DSM,DAPNIA,SAp,CE Saclay, F-91191 Gif Sur Yvette, France. NASA, Ames Res Ctr, Div Space Sci & Astrobiol, Moffett Field, CA 94035 USA. Univ Tubingen, Inst Astron & Astrophys, Abt Computat Phys, D-72076 Tubingen, Germany. Univ Nacl Autonoma Mexico, IA, Ciudad Univ, Mexico City 04510, DF, Mexico. RP Masset, FS (reprint author), Univ Paris 07, CNRS, CEA, AIM UMR 7158,DSM,DAPNIA,SAp,CE Saclay, F-91191 Gif Sur Yvette, France. EM fmasset@cea.fr; gdangelo@arc.nasa.gov; wilhelm.kley@uni-tuebingen.de RI Kley, Wilhelm/A-4921-2012; D'Angelo, Gennaro/L-7676-2014 OI D'Angelo, Gennaro/0000-0002-2064-0801 NR 47 TC 111 Z9 112 U1 1 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 730 EP 745 DI 10.1086/507515 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700066 ER PT J AU Fortney, JJ Cooper, CS Showman, AP Marley, MS Freedman, RS AF Fortney, J. J. Cooper, C. S. Showman, A. P. Marley, M. S. Freedman, R. S. TI The influence of atmospheric dynamics on the infrared spectra and light curves of hot Jupiters SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : eclipsing; planetary systems; radiative transfer; stars : individual (HD 209458) ID EXTRASOLAR GIANT PLANETS; MASS DWARF STARS; HD 209458B; SECONDARY ECLIPSE; CARBON-MONOXIDE; TRANSITING PLANET; THERMAL EMISSION; BROWN DWARFS; SOLAR-SYSTEM; GLIESE 229B AB We explore the infrared spectrum of a three-dimensional dynamical model of planet HD 209458b as a function of orbital phase. The dynamical model predicts dayside atmospheric pressure-temperature profiles that are much more isothermal at pressures less than 1 bar than one-dimensional radiative-convective models have found. The resulting dayside thermal spectra are very similar to a blackbody, and only weak water absorption features are seen at short wavelengths. The dayside emission is consequently in better agreement with ground-based and space-based secondary eclipse data than any previous models, which predict strong flux peaks and deep absorption features. At other orbital phases, absorption due to carbon monoxide and methane is also predicted. We compute the spectra under two treatments of atmospheric chemistry: one uses the predictions of equilibrium chemistry, and the other uses non-equilibrium chemistry, which ties the timescales of methane and carbon monoxide chemistry to dynamical timescales. As a function of orbital phase, we predict planet-to-star flux ratios for standard infrared bands and all Spitzer Space Telescope bands. In Spitzer bands, we predict two- to fifteenfold variation in planetary flux as a function of orbital phase with equilibrium chemistry, and two- to fourfold variation with nonequilibrium chemistry. Variation is generally more pronounced in bands from 3 to 10 mu m than at longer wavelengths. The orbital phase of maximum thermal emission in infrared bands is 15-45 orbital degrees before the time of secondary eclipse. Changes in flux as a function of orbital phase for HD 209458b should be observable with Spitzer, given the previously achieved observational error bars. C1 NASA, Ames Res Ctr, Div Space Sci & Astrobiol, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94043 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. RP Fortney, JJ (reprint author), NASA, Ames Res Ctr, Div Space Sci & Astrobiol, MS 245-3, Moffett Field, CA 94035 USA. EM jfortney@arc.nasa.go; curtis@lpl.arizona.edu; showman@lpl.arizona.edu; mark.s.marley@nasa.gov; freedman@darkstar.arc.nasa.gov OI Fortney, Jonathan/0000-0002-9843-4354 NR 58 TC 108 Z9 108 U1 0 U2 7 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 746 EP 757 DI 10.1086/508442 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700067 ER PT J AU Bloomfield, DS McAteer, RTJ Mathioudakis, M Keenan, FP AF Bloomfield, D. Shaun McAteer, R. T. James Mathioudakis, Mihalis Keenan, Francis P. TI The influence of magnetic field on oscillations in the solar chromosphere SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : chromosphere; Sun : magnetic fields; Sun : oscillations; Sun : UV radiation ID FREQUENCY ACOUSTIC-WAVES; QUIET SUN; CORONAL LOOPS; K-LINE; ATMOSPHERE; DYNAMICS; NETWORK; TRACE; SUNSPOT; FLUX AB Two sequences of solar images obtained by the Transition Region and Coronal Explorer in three UV passbands are studied using wavelet and Fourier analysis and compared to the photospheric magnetic flux measured by the Michelson Doppler Interferometer on the Solar Heliospheric Observatory to study wave behavior in differing magnetic environments. Wavelet periods show deviations from the theoretical cutoff value and are interpreted in terms of inclined fields. The variation of wave speeds indicates that a transition from dominant fast-magnetoacoustic waves to slow modes is observed when moving from network into plages and umbrae. This implies preferential transmission of slow modes into the upper atmosphere, where they may lead to heating or be detected in coronal loops and plumes. C1 Queens Univ Belfast, Dept Phys & Astron, Belfast BT7 1NN, Antrim, North Ireland. NASA, Goddard Space Flight Ctr, Solar Phys Branch, Greenbelt, MD 20771 USA. RP Bloomfield, DS (reprint author), Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. RI McAteer, R. T. James/D-3736-2011; Bloomfield, Shaun/G-5809-2011 OI Bloomfield, Shaun/0000-0002-4183-9895 NR 40 TC 22 Z9 22 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP 812 EP 819 DI 10.1086/508409 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TX UT WOS:000242125700073 ER PT J AU Egami, E Rieke, GH Fadda, D Hines, DC AF Egami, E. Rieke, G. H. Fadda, D. Hines, D. C. TI A large mass of H(2) in the brightest cluster galaxy in Zwicky 3146 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cooling flows; galaxies : active; galaxies : clusters : general; galaxies : elliptical and lenticular, cD; infrared : galaxies ID SPITZER-SPACE-TELESCOPE; WARM MOLECULAR-HYDROGEN; COOLING FLOW CLUSTERS; X-RAY SOURCES; STAR-FORMATION; INFRARED SPECTROGRAPH; STARBURST GALAXIES; SHOCK-WAVES; ISO-SWS; SPECTROSCOPY AB We present the Spitzer/IRS mid-infrared spectrum of the infrared-luminous (L(IR) = 4 x 10(11) L(circle dot)) brightest cluster galaxy (BCG) in the X-ray-luminous cluster Zwicky 3146 (Z3146; z = 0.29). The spectrum shows strong aromatic emission features, indicating that the dominant source of the infrared luminosity is star formation. The most striking feature of the spectrum, however, is the exceptionally strong molecular hydrogen (H(2)) emission lines, which seem to be shock-excited. The line luminosities and inferred warm H(2) gas mass (similar to 10(10) M(circle dot)) are 6 times larger than those of NGC 6240, the most H(2)-luminous galaxy at z <= 0.05. Together with the large amount of cold H(2) detected previously (similar to 10(11) M(circle dot)), this indicates that the Z3146 BCG contains disproportionately large amounts of both warm and cold H(2) gas for its infrared luminosity, which may be related to the intracluster gas cooling process in the cluster core. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. NASA, CALTECH, Herschel Sci Ctr, Pasadena, CA 91125 USA. Space Sci Inst, Boulder, CO 80301 USA. RP Egami, E (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA. NR 37 TC 44 Z9 44 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP L21 EP L24 DI 10.1086/509886 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TZ UT WOS:000242125900006 ER PT J AU Reynolds, SP Borkowski, KJ Hwang, U Harrus, I Petre, R Dubner, G AF Reynolds, Stephen P. Borkowski, Kazimierz J. Hwang, Una Harrus, Ilana Petre, Robert Dubner, Gloria TI A new young galactic supernova remnant containing a compact object: g15.9+0.2 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (G15.9+0.2); stars : neutron; supernova remnants; X-rays : general; X-rays : ISM ID NEUTRON-STAR; RAY; GLIMPSE AB We identify the radio-emitting shell-type supernova remnant G15.9 + 0.2 as a relatively young remnant containing an X-ray point source that may be its associated neutron star. The integrated spectrum of the remnant shell obtained from our 30 ks exploratory Chandra observation shows very strong lines that require elevated element abundances from ejecta, in particular of sulfur. A plane-shock model fit gives a temperature kT = 0.9 (0.8, 1.0) keV, an ionization timescale n(e)t = 6 (4, 9) x 10(10) cm(-3) s, and a sulfur abundance of 2.1 (1.7, 2.7) times solar (90% confidence e limits). Two-component models with one solar and one enriched component are also plausible, but they are not well constrained by the data. Various estimates give a remnant age of order 10(3) yr, which would make G15.9 + 0.2 among the dozen or so youngest remnants in the Galaxy. The sparse point-source spectrum is consistent with either a steep Gamma similar to 4 power law or a kT similar to 0.4 keV blackbody. The spectrum is absorbed by a H column density N-H similar to 4 x 10(22) cm(-2) similar to that required for the remnant shell. The implied 2-9.5 keV source luminosity is about 10(33) ergs s(-1) for an assumed distance of 8.5 kpc consistent with the high absorption column. We suggest that the point source is either a rotation-powered pulsar or a compact central object. C1 N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Astron & Fis Espacio, RA-1428 Buenos Aires, DF, Argentina. RP Reynolds, SP (reprint author), N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. EM stephen_reynolds@ncsu.edu NR 20 TC 20 Z9 20 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP L45 EP L48 DI 10.1086/510066 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TZ UT WOS:000242125900012 ER PT J AU Stecker, FW Scully, ST AF Stecker, F. W. Scully, S. T. TI A simple analytic treatment of the intergalactic absorption effect in blazar gamma-ray spectra SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : general; gamma rays : theory ID SPITZER VIEW; DISCOVERY; EMISSION AB We derive a new and user-friendly simple analytic approximation for determining the effect of intergalactic absorption on the gamma-ray spectra of TeV blazars in the energy range and in the redshift 0.2 TeV < E-gamma < 2 TeV g range 0.05 < z < 0.4. In these ranges, the form of the absorption coefficient tau(E-gamma) is approximately logarithmic. g The effect of this energy dependence is to steepen intrinsic source spectra such that a source with an approximate power-law spectral index Gamma(s) is converted to one with an observed spectral index Gamma(o) similar or equal to Gamma(s) + Delta Gamma(z), where Delta Gamma(z) is a linear function of z in the redshift range 0.05-0.4. We apply this approximation to the spectra of seven TeV blazars. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. James Madison Univ, Dept Phys, Harrisonburg, VA 22807 USA. RP Stecker, FW (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM stecker@milkyway.gsfc.nasa.gov; scullyst@jmu.edu RI Stecker, Floyd/D-3169-2012 NR 14 TC 30 Z9 30 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2006 VL 652 IS 1 BP L9 EP L11 DI 10.1086/509885 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 106TZ UT WOS:000242125900003 ER PT J AU Marshak, A Martins, JV Zubko, V Kaufman, YJ AF Marshak, A. Martins, J. V. Zubko, V. Kaufman, Y. J. TI What does reflection from cloud sides tell us about vertical distribution of cloud droplet sizes? SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID DISCRETE-ORDINATE-METHOD; OPTICAL-THICKNESS; RADIATIVE-TRANSFER; CONVECTIVE CLOUDS; EFFECTIVE RADIUS; LIQUID WATER; PRECIPITATION; ALGORITHM; RAIN; SCATTERING AB Cloud development, the onset of precipitation and the effect of aerosol on clouds depend on the structure of the cloud profiles of droplet size and phase. Aircraft measurements of cloud profiles are limited in their temporal and spatial extent. Satellites were used to observe cloud tops not cloud profiles with vertical profiles of precipitation-sized droplets anticipated from CloudSat. The recently proposed CLAIM-3D satellite mission (cloud aerosol interaction mission in 3-D) suggests to measure profiles of cloud microphysical properties by retrieving them from the solar and infrared radiation reflected or emitted from cloud sides. Inversion of measurements from the cloud sides requires rigorous understanding of the 3-dimensional (3-D) properties of clouds. Here we discuss the reflected sunlight from the cloud sides and top at two wavelengths: one nonabsorbing to solar radiation (0.67 mu m) and one with liquid water efficient absorption of solar radiation (2.1 mu m). In contrast to the plane-parallel approximation, a conventional approach to all current operational retrievals, 3-D radiative transfer is used for interpreting the observed reflectances. General properties of the radiation reflected from the sides of an isolated cloud are discussed. As a proof of concept, the paper shows a few examples of radiation reflected from cloud fields generated by a simple stochastic cloud model with the prescribed vertically resolved microphysics. To retrieve the information about droplet sizes, we propose to use the probability density function of the droplet size distribution and its first two moments instead of the assumption about fixed values of the droplet effective radius. The retrieval algorithm is based on the Bayesian theorem that combines prior information about cloud structure and microphysics with radiative transfer calculations. C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. RS Informat Syst Inc, Greenbelt, MD USA. NASA, Goddard Space Flight Ctr, Goddard Earth Sci Data Informat Serv Ctr, Greenbelt, MD USA. RP Marshak, A (reprint author), NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. EM alexander.marshak@nasa.gov RI Marshak, Alexander/D-5671-2012 NR 33 TC 12 Z9 12 U1 1 U2 12 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7316 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD NOV 20 PY 2006 VL 6 BP 5295 EP 5305 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 106KL UT WOS:000242099300002 ER PT J AU Mackas, DL Peterson, WT Ohman, MD Lavaniegos, BE AF Mackas, D. L. Peterson, W. T. Ohman, M. D. Lavaniegos, B. E. TI Zooplankton anomalies in the California Current system before and during the warm ocean conditions of 2005 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOUTHERN CALIFORNIA; NORTHEAST PACIFIC; BRITISH-COLUMBIA; VARIABILITY; COMMUNITY; COPEPODS; REGIME; OREGON AB Zooplankton in the California Current had large anomalies in biomass and composition in 2005. The zone most strongly affected extended from northern California to southern British Columbia, where zooplankton biomass was low from spring through autumn, community composition showed reduced dominance by northern origin taxa, and life cycles of some species shifted to earlier in the year. Although similar anomalies have previously been observed over the entire California Current system during strong El Nino events, the 2005 zooplankton anomalies were more localized, initiated by a combination of very warm temperatures ( since early 2003), plus weak and late upwelling, and low phytoplankton productivity in spring and early summer of 2005. However, the zooplankton anomalies persisted longer: through the remainder of 2005 and into 2006. C1 Fisheries & Oceans Canada, Inst Ocean Sci, Sidney, BC V8L 4B2, Canada. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, NOAA, Newport, OR 97365 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Ctr Invest Cient & Educ Super Ensenada, Dept Oceanog Biol, Ensenada, Baja California, Mexico. RP Mackas, DL (reprint author), Fisheries & Oceans Canada, Inst Ocean Sci, Sidney, BC V8L 4B2, Canada. EM mackasd@pac.dfo-mpo.gc.ca RI Ohman, Mark/C-8763-2009 NR 19 TC 49 Z9 49 U1 2 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 18 PY 2006 VL 33 IS 22 AR L22S07 DI 10.1029/2006GL027930 PG 7 WC Geosciences, Multidisciplinary SC Geology GA 107MK UT WOS:000242175500005 ER PT J AU Su, H Waliser, DE Jiang, JH Li, JL Read, WG Waters, JW Tompkins, AM AF Su, Hui Waliser, Duane E. Jiang, Jonathan H. Li, Jui-lin Read, William G. Waters, Joe W. Tompkins, Adrian M. TI Relationships of upper tropospheric water vapor, clouds and SST: MLS observations, ECMWF analyses and GCM simulations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEA-SURFACE TEMPERATURE; TROPICAL CONVECTION; DEEP CONVECTION; EOS MLS; SATELLITE; HUMIDITY AB The relationships of upper tropospheric water vapor (UTWV), cloud ice and sea surface temperature (SST) are examined in the annual cycles of ECMWF analyses and simulations from 15 atmosphere-ocean coupled models which were contributed to the IPCC AR4. The results are compared with the observed relationships based on UTWV and cloud ice measurements from MLS on Aura. It is shown that the ECMWF analyses produce positive correlations between UTWV, cloud ice and SST, similar to the MLS data. The rate of the increase of cloud ice and UTWV with SST is about 30% larger than that for MLS. For the IPCC simulations, the relationships between UTWV, cloud ice and SST are qualitatively captured. However, the magnitudes of the simulated cloud ice show a considerable disagreement between models, by nearly a factor of 10. The amplitudes of the approximate linear relations between UTWV, cloud ice and SST vary by a factor up to 4. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. European Ctr Medium Range Weather Forecasts, Reading RG1 1NT, Berks, England. RP Su, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM hui.su@jpl.nasa.gov RI Tompkins, Adrian/N-6472-2013 OI Tompkins, Adrian/0000-0003-0975-6691 NR 15 TC 16 Z9 17 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 18 PY 2006 VL 33 IS 22 AR L22802 DI 10.1029/2006GL027582 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 107MK UT WOS:000242175500002 ER PT J AU Ejiri, MK Terao, Y Sugita, T Nakajima, H Yokota, T Toon, GC Sen, B Wetzel, G Oelhaf, H Urban, J Murtagh, D Irie, H Saitoh, N Tanaka, T Kanzawa, H Shiotani, M Aoki, S Hashida, G Machida, T Nakazawa, T Kobayashi, H Sasano, Y AF Ejiri, M. K. Terao, Y. Sugita, T. Nakajima, H. Yokota, T. Toon, G. C. Sen, B. Wetzel, G. Oelhaf, H. Urban, J. Murtagh, D. Irie, H. Saitoh, N. Tanaka, T. Kanzawa, H. Shiotani, M. Aoki, S. Hashida, G. Machida, T. Nakazawa, T. Kobayashi, H. Sasano, Y. TI Validation of the improved limb atmospheric spectrometer-II (ILAS-II) version 1.4 nitrous oxide and methane profiles SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SATELLITE; N2O; CH4; STRATOSPHERE; RETRIEVAL; ALGORITHM; PRODUCTS; SAMS AB This study assesses polar stratospheric nitrous oxide (N2O) and methane (CH4) data from the Improved Limb Atmospheric Spectrometer-II (ILAS-II) on board the Advanced Earth Observing Satellite-II (ADEOS-II) retrieved by the Version 1.4 retrieval algorithm. The data were measured between January and October 2003. Vertical profiles of ILAS-II volume mixing ratio (VMR) data are compared with data from two balloon-borne instruments, the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS-B) and the MkIV instrument, as well as with two satellite sensors, the Odin Sub-Millimetre Radiometer (SMR) for N2O and the Halogen Occultation Experiment (HALOE) for CH4. Relative percentage differences between the ILAS-II and balloon/satellite data and their median values are calculated in 10-ppbv-wide bins for N2O (from 0 to 400 ppbv) and in 0.05-ppmv-wide bins for CH4 (from 0 to 2 ppmv) in order to assess systematic differences between the ILAS-II and balloon/satellite data. According to this study, the characteristics of the ILAS-II Version 1.4 N2O and CH4 data differ between hemispheres. For ILAS-II N2O VMR larger than 250 ppbv, the ILAS-II N2O agrees with the balloon/SMR N2O within +/- 20% in both hemispheres. The ILAS-II N2O in the VMR range from 30-50 to 250 ppbv (corresponding to altitudes of similar to 17-30 km in the Northern Hemisphere (NH, mainly outside the polar vortex) and similar to 13-21 km in the Southern Hemisphere (SH, mainly inside the polar vortex) is smaller by similar to 10-30% than the balloon/SMR N2O. For ILAS-II N2O VMR smaller than 30 ppbv (>similar to 21 km) in the SH, the differences between the ILAS-II and SMR N2O are within +/- 10 ppbv. For ILAS-II CH4 VMR larger than 1 ppmv (similar to 30 km) and the ILAS-II CH4 for its VMR smaller than 1 ppmv (>similar to 25 km) only in the NH, are abnormally small compared to the balloon/satellite data. C1 Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan. Tohoku Univ, Dept Geophys, Grad Sch Sci, Aoba Ku, Sendai, Miyagi 9808578, Japan. Utah State Univ, Ctr Atmospher & Space Sci, Logan, UT 84322 USA. Natl Inst Polar Res, Itabashi Ku, Tokyo, Japan. Japan Agcy Marine Earth Sci & Technol, Frontier Res Ctr Global Change, Kanagawa Ku, Yokohama, Kanagawa 2360001, Japan. Nagoya Univ, Grad Sch Environm Studies, Dept Earth & Environm Sci, Chikusa Ku, Nagoya, Aichi 4648601, Japan. Cent Res Inst Elect Power Ind, Tokyo 2018511, Japan. Chalmers, Dept Radio & Space Sci, SE-41296 Gothenburg, Sweden. Inst Meteorol & Klimaforsch, D-76021 Karlsruhe, Germany. Univ Tokyo, Ctr Climate Syst Res, Kashiwa, Chiba 2778568, Japan. Kyoto Univ, Res Inst Sustainable Humanosphere, Uji, Kyoto 6110011, Japan. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ejiri, MK (reprint author), Natl Inst Environm Studies, 16-2 Onogawa, Tsukuba, Ibaraki 3058506, Japan. EM mitsumu@cc.usu.edu RI Sasano, Yasuhiro/C-2927-2009; Terao, Yukio/A-2099-2008; Wetzel, Gerald/A-7065-2013; Oelhaf, Hermann/A-7895-2013; Urban, Jo/F-9172-2010; Murtagh, Donal/F-8694-2011; OI Sasano, Yasuhiro/0000-0001-7470-5642; Terao, Yukio/0000-0003-2345-7073; Urban, Jo/0000-0001-7026-793X; Murtagh, Donal/0000-0003-1539-3559; Sugita, Takafumi/0000-0002-0508-7040 NR 23 TC 15 Z9 15 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 18 PY 2006 VL 111 IS D22 AR D22S90 DI 10.1029/2005JD006449 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 107MR UT WOS:000242176200001 ER PT J AU Washenfelder, RA Toon, GC Blavier, JF Yang, Z Allen, NT Wennberg, PO Vay, SA Matross, DM Daube, BC AF Washenfelder, R. A. Toon, G. C. Blavier, J. -F. Yang, Z. Allen, N. T. Wennberg, P. O. Vay, S. A. Matross, D. M. Daube, B. C. TI Carbon dioxide column abundances at the Wisconsin Tall Tower site SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INTEGRATED ABSORPTION INTENSITIES; ATMOSPHERIC CO2; MOLECULAR-OXYGEN; 0,0 TRANSITION; O-2; PRESSURE; SURFACE; MODEL; COEFFICIENTS; STRENGTHS AB We have developed an automated observatory for measuring atmospheric column abundances of CO2 and O-2 using near-infrared spectra of the Sun obtained with a high spectral resolution Fourier Transform Spectrometer (FTS). This is the first dedicated laboratory in a new network of ground-based observatories named the Total Carbon Column Observing Network. This network will be used for carbon cycle studies and validation of spaceborne column measurements of greenhouse gases. The observatory was assembled in Pasadena, California, and then permanently deployed to northern Wisconsin during May 2004. It is located in the heavily forested Chequamegon National Forest at the WLEF Tall Tower site, 12 km east of Park Falls, Wisconsin. Under clear sky conditions, similar to 0.1% measurement precision is demonstrated for the retrieved column CO2 abundances. During the Intercontinental Chemical Transport Experiment-North America and CO2 Boundary Layer Regional Airborne Experiment campaigns in summer 2004, the DC-8 and King Air aircraft recorded eight in situ CO2 profiles over the WLEF site. Comparison of the integrated aircraft profiles and CO2 column abundances shows a small bias (similar to 2%) but an excellent correlation. C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Washenfelder, RA (reprint author), NOAA, Div Chem Sci, Boulder, CO 80305 USA. EM rebecca.washenfelder@noaa.gov RI Washenfelder, Rebecca/E-7169-2010; Wennberg, Paul/A-5460-2012 OI Washenfelder, Rebecca/0000-0002-8106-3702; NR 31 TC 129 Z9 130 U1 2 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 18 PY 2006 VL 111 IS D22 AR D22305 DI 10.1029/2006JD007154 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 107MR UT WOS:000242176200012 ER PT J AU Broks, P Knoll, A Wilczek, F Miller, G McKay, C Brooks, R Krauss, L Loftus, E AF Broks, Paul Knoll, Andrew Wilczek, Frank Miller, Geoffrey McKay, Chris Brooks, Rodney Krauss, Lawrence Loftus, Elizabeth TI What is consciousness? SO NEW SCIENTIST LA English DT Editorial Material C1 Harvard Univ, Cambridge, MA 02138 USA. MIT, Comp Sci & Artificial Intelligence Lab, Cambridge, MA 02139 USA. Univ New Mexico, Albuquerque, NM 87131 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. Univ Calif Irvine, Irvine, CA USA. Univ Plymouth, Plymouth PL4 8AA, Devon, England. RP Broks, P (reprint author), Univ Plymouth, Plymouth PL4 8AA, Devon, England. NR 0 TC 0 Z9 0 U1 1 U2 7 PU REED BUSINESS INFORMATION LTD PI SUTTON PA QUADRANT HOUSE THE QUADRANT, SUTTON SM2 5AS, SURREY, ENGLAND SN 0262-4079 J9 NEW SCI JI New Sci. PD NOV 18 PY 2006 VL 192 IS 2578 BP 56 EP 61 DI 10.1016/S0262-4079(06)61127-5 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 110DH UT WOS:000242358000029 ER PT J AU Castillo-Rogez, J AF Castillo-Rogez, Julie TI Internal structure of Rhea SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MASS-RADIUS RELATIONSHIPS; SMALL ICY SATELLITES; INTERIOR STRUCTURE; GRAVITY-FIELD; EVOLUTION; MODELS; SATURN; CONVECTION; WATER; DIFFERENTIATION AB [1] We model the interior of Rhea on the basis of observational constraints and the results from geodynamical models available in the literature. Ten main types of models are defined, depending on the presence or absence of a high-pressure ice layer ( ice II), and the extent of separation of the rock component from the volatiles. The degree-two gravity coefficients are computed for each of these models in order to assess which properties of the interior are likely to be inferred from Cassini radio science measurements scheduled on 26 November 2005. C-22 greater than 2.5 x 10(-4) indicates that the satellite is undifferentiated, except for a slight increase in density with depth resulting from material self-compression. C-22 between 1.67 x 10(-4) (lower bound) and 1.90 x 10(-4) indicates the presence of a rocky core, whose radius can be determined from the satellite's mass and ices densities, for a given temperature profile. For other values, most of the ten models cannot be distinguished from each other. However, assumptions on the density of the rock phase, presence or absence of ice II, and the degree of differentiation could allow a unique model to be determined in many cases. While the calculation presented in this work assumes that Rhea is in hydrostatic equilibrium, it is likely that Rhea' gravity field is partly affected by nonhydrostatic anomalies. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Castillo-Rogez, J (reprint author), CALTECH, Jet Prop Lab, M-S 230-260V,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM julie.c.castillo@jpl.nasa.gov NR 45 TC 22 Z9 22 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 17 PY 2006 VL 111 IS E11 AR E11005 DI 10.1029/2004JE002379 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 107NF UT WOS:000242177600001 ER PT J AU Farrell, WM Marshall, JR Cummer, SA Delory, GT Desch, MD AF Farrell, W. M. Marshall, J. R. Cummer, S. A. Delory, G. T. Desch, M. D. TI A model of the ULF magnetic and electric field generated from a dust devil SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MARS AB [1] It has been demonstrated that terrestrial dust devils emit ULF magnetic radiation. On Mars, dust devils may also generate such magnetic emissions, which might be used as a hazard alert for manned missions. Specifically, grains in dust devils become charged via contact electrification, and it has been proposed that the cyclonic motion of these charged grains in the vortex wind fields accounts for the magnetic emission. To test this hypothesis in general and the possible Mars application, a computer simulation of the contact electrification/wind blowing phenomena was created, with the charge distribution and resulting magnetic fields monitored as a function of time. The results indicate that indeed a fluctuating charge distribution in a vortex wind can account for the ULF magnetic fields measured from a dust devil. The contact electrification process is a function of composition, and we demonstrate that the various compositions will give rise to different magnetic field responses from the dust devil. We also demonstrate that this system of swirling charged grains develops vertical currents and associated electric fields, as suggested in preceding works. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. SETI Inst, Mountain View, CA 94043 USA. Duke Univ, Dept Elect & Comp Engn, Durham, NC 27708 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Farrell, WM (reprint author), NASA, Goddard Space Flight Ctr, Code 695, Greenbelt, MD 20771 USA. EM william.farrell@gsfc.nasa.gov RI Cummer, Steven/A-6118-2008; Farrell, William/I-4865-2013 OI Cummer, Steven/0000-0002-0002-0613; NR 20 TC 11 Z9 11 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 17 PY 2006 VL 111 IS E11 AR E11004 DI 10.1029/2006JE002689 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 107NF UT WOS:000242177600003 ER PT J AU Livengood, TA Kostiuk, T Sonnabend, G Annen, JN Fast, KE Tokunaga, A Murakawa, K Hewagama, T Schmulling, F Schieder, R AF Livengood, T. A. Kostiuk, T. Sonnabend, G. Annen, J. N. Fast, K. E. Tokunaga, A. Murakawa, K. Hewagama, T. Schmuelling, F. Schieder, R. TI High-resolution infrared spectroscopy of ethane in Titan's stratosphere in the Huygens epoch SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID WAVE-ASTRONOMY-SATELLITE; ATMOSPHERE; ABUNDANCE; WINDS; INSTRUMENT; DATABASE; PROBE; LINES AB [ 1] High-resolution infrared spectroscopy of ethane (C2H6) emission features formed in the stratosphere of Titan was collected on disc center at 11.74 mu m wavelength (851 cm(-1)) on 15 January 2005 UT. The observations were obtained at the Subaru 8.2 m telescope of the National Astronomical Observatory of Japan on Mauna Kea, Hawaii, using the NASA Goddard Space Flight Center Heterodyne Instrument for Planetary Winds and Composition (HIPWAC). Fully resolved rotational-vibrational transitions of C2H6 were measured with resolving power lambda/Delta lambda >= 10(6) by infrared heterodyne spectroscopy (IRHS). The spectrum is reproduced most effectively by vertical profiles of ethane abundance that are uniform through the stratosphere and enhanced within the mesosphere. Profiles in which there is a significant gradient within the stratosphere are not favored. The retrieved stratospheric ethane mole fraction depends weakly on the form invoked for the mesospheric enhancement. Two forms of the ethane mole fraction profile are found to reproduce the observed spectrum effectively: the best fitting results are obtained with a profile in which the mesospheric ethane concentration increases logarithmically versus decreasing pressure, retrieving a stratospheric ethane concentration of 8.2 +/- 2.1 x 10(-6) (1 sigma), increasing proportional to p(-1.2) from the stratopause through the mesosphere ( p is pressure). A second form of profile, in which the mesospheric ethane concentration is enhanced uniformly by a factor of 9.5, retrieves a stratospheric concentration of 9.7 +/- 4.9 x 10(-6) (1 sigma), with the enhancement discontinuity at about one scale height above the stratopause. The retrieved stratospheric mole fraction is consistent with earlier retrievals from IRHS and is somewhat less than contemporaneous retrievals from infrared spectroscopy at lower resolution by the Cassini spacecraft. The retrieved mesospheric concentration is consistent with in situ measurements in Titan's thermosphere made by the Cassini Ion Neutral Mass Spectrometer instrument during the Titan flyby ( Waite et al., 2005). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Ctr Earth & Space Sci Educ, Washington, DC USA. Univ Cologne, Inst Phys, D-50937 Cologne, Germany. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Max Planck Inst Radioastron, D-53121 Bonn, Germany. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Livengood, TA (reprint author), NASA, Goddard Space Flight Ctr, Code 693,Bldg 2,Room 166, Greenbelt, MD 20771 USA. EM timothy.a.livengood@gsfc.nasa.gov RI Livengood, Timothy/C-8512-2012; Hewagama, T/C-8488-2012; Kostiuk, Theodor/A-3077-2014 NR 33 TC 4 Z9 4 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 17 PY 2006 VL 111 IS E11 AR E11S90 DI 10.1029/2005JE002669 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 107NF UT WOS:000242177600002 ER PT J AU Grimberg, A Baur, H Bochsler, P Buhler, F Burnett, DS Hays, CC Heber, VS Jurewicz, AJG Wieler, R AF Grimberg, Ansgar Baur, Heinrich Bochsler, Peter Buehler, Fritz Burnett, Donald S. Hays, Charles C. Heber, Veronika S. Jurewicz, Amy J. G. Wieler, Rainer TI Solar wind neon from Genesis: Implications for the lunar noble gas record SO SCIENCE LA English DT Article ID ENERGETIC PARTICLES; METEORITES; ISOTOPES; NUCLEI; ORIGIN; MANTLE; ARGON; SOIL AB Lunar soils have been thought to contain two solar noble gas components with distinct isotopic composition. One has been identified as implanted solar wind, the other as higher-energy solar particles. The latter was puzzling because its relative amounts were much too large compared with present-day fluxes, suggesting periodic, very high solar activity in the past. Here we show that the depth-dependent isotopic composition of neon in a metallic glass exposed on NASA's Genesis mission agrees with the expected depth profile for solar wind neon with uniform isotopic composition. Our results strongly indicate that no extra high-energy component is required and that the solar neon isotope composition of lunar samples can be explained as implantation-fractionated solar wind. C1 ETH Zurich NW, CH-8092 Zurich, Switzerland. Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. CALTECH, Dept Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Arizona State Univ, Ctr Meteorite Studies, Tempe, AZ 85287 USA. RP Grimberg, A (reprint author), ETH Zurich NW, Clausiusstr 25, CH-8092 Zurich, Switzerland. EM grimberg@erdw.ethz.ch RI Wieler, Rainer/A-1355-2010 OI Wieler, Rainer/0000-0001-5666-7494 NR 28 TC 66 Z9 68 U1 9 U2 46 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD NOV 17 PY 2006 VL 314 IS 5802 BP 1133 EP 1135 DI 10.1126/science.1133568 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 105PW UT WOS:000242045800041 PM 17110575 ER PT J AU Farrugia, CJ Jordanova, VK Thomsen, MF Lu, G Cowley, SWH Ogilvie, KW AF Farrugia, C. J. Jordanova, V. K. Thomsen, M. F. Lu, G. Cowley, S. W. H. Ogilvie, K. W. TI A two-ejecta event associated with a two-step geomagnetic storm SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; PERIODIC MAGNETOSPHERIC SUBSTORMS; RING CURRENT DYNAMICS; SOLAR-WIND; MAGNETIC STORMS; COMPLEX EJECTA; PLASMA SHEET; FIELD; CLOUDS; EARTH AB A new view on how large disturbances in the magnetosphere may be prolonged and intensified further emerges from a recently discovered interplanetary process: the collision/ merger of interplanetary (IP) coronal mass ejections (ICMEs; ejecta) within 1 AU. As shown in a recent pilot study, the merging process changes IP parameters dramatically with respect to values in isolated ejecta. The resulting geoeffects of the coalesced ("complex'') ejecta reflect a superposition of IP triggers which may result in, for example, two-step, major geomagnetic storms. In a case study, we isolate the effects on ring current enhancement when two coalescing ejecta reached Earth on 31 March 2001. The magnetosphere "senses'' the presence of the two ejecta and responds with a reactivation of the ring current soon after it started to recover from the passage of the first ejection, giving rise to a double-dip (DD) great storm ( each min Dst < -250 nT). A drift-loss global kinetic model of ring current buildup shows that in this case the major factor determining the intensity of the storm activity is the very high ( up to similar to 10 cm(-3)) plasma sheet density. The plasma sheet density, in turn, is found to correlate well with the very high solar wind density, suggesting the compression of the leading ejecta as the source of the hot, superdense plasma sheet in this case. This correlation is similar to that obtained in a previous investigation extending over several years, but the present case study extends the range of plasma sheet densities from similar to 2 to similar to 10 cm(-3). Since the features of the ejecta interaction in this example are fairly general, we propose that interacting ejecta are a new, important IP source of DD major storms. Peculiarities in the behavior of the magnetopause current during these extreme events are briefly discussed in the light of recent work. In a brief discussion of a second example (21 - 23 October 2001), we suggest that by strengthening the leading shock, the ejecta merger may have added to the "shock-driver gas'' origin of DD geomagnetic storms by increasing the ability of the shock to compress preexisting B(z) < 0 magnetic fields. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Los Alamos Natl Lab, Los Alamos, NM USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Farrugia, CJ (reprint author), Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England. EM charlie.farrugia@unh.edu; mthomsen@lanl.gov; ganglu@hao.ucar.edu; swhc1@ion.le.ac.uk; keith.w.ogilvie@nasa.gov RI Lu, Gang/A-6669-2011; OI Jordanova, Vania/0000-0003-0475-8743 NR 69 TC 35 Z9 36 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 16 PY 2006 VL 111 IS A11 AR A11104 DI 10.1029/2006JA011893 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 107NV UT WOS:000242179200011 ER PT J AU Guhathakurta, M Sittler, EC Ofman, L AF Guhathakurta, M. Sittler, E. C., Jr. Ofman, L. TI Semiempirically derived heating function of the corona heliosphere during the Whole Sun Month SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID FAST SOLAR-WIND; INTERPLANETARY DISCONTINUITIES; MAGNETIC-FIELD; ALFVEN WAVES; HELIOGRAPHIC LATITUDES; ULYSSES OBSERVATIONS; PLASMA OBSERVATIONS; PHYSICAL-PROPERTIES; THEORETICAL-MODEL; DENSITY STRUCTURE AB In spite of many recent developments in observations and models of the solar corona, the exact form of the heating function of the solar wind plasma is unknown. Here we attempt to make some progress on that problem by applying a previously developed simplified magnetohydrodynamic model to a unique synthesis of remote sensing coronal observations from SOHO and Spartan 201, and in-situ data from Ulysses spacecraft during the quiescent phase of solar cycle 23 ( 1995 - 1997) which also included the Whole Sun Month (August/September 1996) study period. Our analysis provides for the first time an empirically derived estimate of the heat flux and temperature profile of the corona and interplanetary medium over the solar polar regions as a function of latitude and radial distance for this data set. The latitudinal and radial variation is extended to include the equatorial regions but with less fidelity given the significant structure associated with the streamer belt. Our results suggest that both thermal and nonthermal heating terms contribute to the temperature and heat flux in the low corona, particularly above the poles, with the non-thermal component possibly providing as much as half of the total heat input. C1 NASA Headquarters, Sci Miss Directorate, Washington, DC 20564 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Guhathakurta, M (reprint author), NASA Headquarters, Sci Miss Directorate, Washington, DC 20564 USA. EM madhulika.guhathakurta@nasa.gov; Edward.C.Sittler@nasa.gov; leon.ofman@gsfc.nasa.gov NR 48 TC 12 Z9 13 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 16 PY 2006 VL 111 IS A11 AR A11215 DI 10.1029/2006JA011931 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 107NV UT WOS:000242179200012 ER PT J AU Kaneko, H Bey, KS Hou, GJW AF Kaneko, Hideaki Bey, Kim S. Hou, Gene J. W. TI A discontinuous Galerkin Method for parabolic problems with modified hp-finite element approximation technique SO APPLIED MATHEMATICS AND COMPUTATION LA English DT Article DE discontinuous Galerkin method; parabolic equations; modified hp-finite element method ID P-VERSION; 1-DIMENSION AB A recent paper [Hideaki Kaneko, Kim S. Bey, Gene J.W. Hou, Discontinuous Galerkin finite element method for parabolic problems, preprint November 2000, NASA] is generalized to a case where the spatial region is taken in R-3. The region is assumed to be a thin body, such as a panel on the wing or fuselage of an aerospace vehicle. The traditional h- as well as hp-finite element methods are applied to the surface defined in the x-y variables, while, through the thickness, the technique of the p-element is employed. Time and spatial discretization scheme developed in Kaneko et al. (2000), based upon an assumption of certain weak singularity of parallel to u(t)parallel to(2), is used to derive an optimal a priori error estimate for the current method. (c) 2006 Elsevier Inc. All rights reserved. C1 Old Dominion Univ, Dept Math & Stat, Norfolk, VA 23529 USA. NASA, Langley Res Ctr, Thermal Struct Branch, Hampton, VA 23681 USA. Old Dominion Univ, Dept Engn Mech, Norfolk, VA 23529 USA. RP Kaneko, H (reprint author), Old Dominion Univ, Dept Math & Stat, Norfolk, VA 23529 USA. EM hkaneko@odu.edu NR 19 TC 2 Z9 2 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0096-3003 J9 APPL MATH COMPUT JI Appl. Math. Comput. PD NOV 15 PY 2006 VL 182 IS 2 BP 1405 EP 1417 DI 10.1016/j.amc.2006.05.028 PG 13 WC Mathematics, Applied SC Mathematics GA 122CE UT WOS:000243202500045 ER PT J AU Wal, RLV AF Wal, Randy L. Vander TI Initial investigation of effects of fuel oxygenation on nanostructure of soot from a direct-injection diesel engine SO ENERGY & FUELS LA English DT Article ID MICROSCOPY AB The oxidation rate of a soot sample is related to its nanostructure, that is, to the curvature and relative orientations of its constituent molecular layers. Soot with curved or disorganized layers generally will have a higher reactivity than soot with planar, graphitic layers. This study used high-resolution transmission electron microscopy to analyze the soot produced by the combustion of three different fuels, two of which contain oxygen bonded within the fuel molecule, in a modern diesel engine. Results show that increasing fuel oxygenation produces lower in-cylinder and engine-out soot levels, consistent with existing studies of the effects of fuel oxygenation on soot emissions from diesel engines. The intriguing new information is that increasing the level of fuel oxygenation produced soot with less graphitic structure and correspondingly higher reactivity. Hence, diesel fuel oxygenation may help curtail soot emissions by enhancing soot reactivity and oxidation rates as well as by preventing certain fuel carbon atoms from participating in reactions that form soot. C1 NASA Glenn Res Ctr, Natl Ctr Space Explorat Res, Cleveland, OH 44135 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. RP Wal, RLV (reprint author), NASA Glenn Res Ctr, Natl Ctr Space Explorat Res, 21000 Brookpark Rd, Cleveland, OH 44135 USA. EM Randall.L.VanderWal@grc.nasa.gov NR 16 TC 3 Z9 3 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD NOV 15 PY 2006 VL 20 IS 6 BP 2364 EP 2369 DI 10.1021/ef060201+ PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 105HZ UT WOS:000242022300012 ER PT J AU Suzuki, M Ominami, Y Ngo, Q Yang, CY Yamada, T Cassell, AM Li, J AF Suzuki, Makoto Ominami, Yusuke Ngo, Quoc Yang, Cary Y. Yamada, Toshishige Cassell, Alan M. Li, Jun TI Bright contrast imaging of carbon nanofiber-substrate interface SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SCANNING-ELECTRON-MICROSCOPE; MONTE-CARLO SIMULATION; NANOTUBES AB We present the contrast mechanisms of scanning electron microscopy (SEM) for visualizing the interface between carbon nanofibers (CNFs) and the underlying substrate. SEM imaging with electron beam energies higher than a certain threshold provides different image contrasts depending on whether CNFs are in contact with the substrate or suspended above the substrate. CNFs with diameters ranging from 25 to 250 nm are examined with various electron beam energies. It is found that the threshold energy corresponds to the energy required to penetrate the CNF and its dependence on CNF diameter can be understood using the theory of electron range. This knowledge will be quite useful for interface imaging of all nanostructure devices. (c) 2006 American Institute of Physics. C1 Santa Clara Univ, Ctr Nanostruct, Santa Clara, CA 95053 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Suzuki, M (reprint author), Santa Clara Univ, Ctr Nanostruct, 500 El Camino Real, Santa Clara, CA 95053 USA. EM m1suzuki@scu.edu RI Yamada, Toshishige/E-7834-2012; Li, Jun/H-7771-2013 OI Yamada, Toshishige/0000-0001-7145-9212; Li, Jun/0000-0002-3689-8946 NR 19 TC 10 Z9 10 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 15 PY 2006 VL 100 IS 10 AR 104305 DI 10.1063/1.2382718 PG 5 WC Physics, Applied SC Physics GA 110UY UT WOS:000242408000078 ER PT J AU Bhargava, P Chuang, KC Chen, K Zehnder, A AF Bhargava, Peeyush Chuang, Kathy C. Chen, Kenway Zehnder, Alan TI Moisture diffusion properties of HFPE-II-52 polyimide SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article DE polyimides; diffusion; swelling; glass transition; activation energy ID WATER-VAPOR; GLASSY POLYMER; TRANSPORT; SORPTION AB Moisture diffusion properties of the polyimide HFPE-II-52 were determined using weight gain, weight loss, and swelling experiments over a temperature range of 25-200 degrees C. Below 100 degrees C, diffusivity was measured using standard weight loss and weight gain methods. Above 100 degrees C, diffusivity is found by weight loss experiments performed by placing moisture saturated samples in an oven and recording weight loss dynamically. The diffusivity of the polyimide was found to obey the Arrhenius relation over the entire range of temperature. Weight gain experiments were performed to determine the equilibrium level of moisture absorbed by the polyimide as a function of relative humidity. Swelling experiments were performed to measure swelling strain as a function of moisture absorption. (c) 2006 Wiley Periodicals, Inc. C1 Cornell Univ, Dept Theoret & Appl Mech, Ithaca, NY 14853 USA. NASA, Glenn Res Ctr, Div Mat, Cleveland, OH USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. RP Zehnder, A (reprint author), Cornell Univ, Dept Theoret & Appl Mech, Ithaca, NY 14853 USA. EM p683@cornell.edu NR 39 TC 9 Z9 9 U1 0 U2 2 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD NOV 15 PY 2006 VL 102 IS 4 BP 3471 EP 3479 DI 10.1002/app.24549 PG 9 WC Polymer Science SC Polymer Science GA 091CP UT WOS:000241004000050 ER EF