FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Reale, O Terry, J Masutani, M Andersson, E Riishojgaard, LP Jusem, JC AF Reale, O. Terry, J. Masutani, M. Andersson, E. Riishojgaard, L. P. Jusem, J. C. TI Preliminary evaluation of the European Centre for Medium-Range Weather Forecasts' (ECMWF) Nature Run over the tropical Atlantic and African monsoon region SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DATA ASSIMILATION; EASTERLY WAVES; JET AB Meteorological observing systems are continuously being developed to improve our knowledge of the atmosphere and our forecasting capabilities. Observing System Simulation Experiments (OSSEs) are a general technique to assess a priori the potential impact of future instruments, which is particularly important in the case of spaceborne systems. One crucial component of OSSEs is the Nature Run (NR), representing a virtual atmosphere from which observations can be simulated so that the impact of future instruments can be assessed. A community-based, 13-month T511 NR was designed in an international collaborative effort and was produced by the European Centre for Medium-Range Weather Forecasts (ECMWF) to build a next-generation OSSE capability. This new Joint OSSE NR is being analyzed with emphasis on tropical development over the western African monsoon region and the tropical Atlantic. The NR representation of the African Easterly Jet and the characteristics of African Easterly Waves including their propagation and development in tropical-cyclone like vortices are investigated. This is the first NR that encompasses one entire Atlantic tropical cyclone season producing realistic tropical cyclone activity. As such it is a valuable tool to perform OSSEs to assess the possible impact of future instruments targeting hurricanes. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. European Ctr Medium Range Weather Forecasts, Data Assimilat Sect, Reading RG2 9AX, Berks, England. NOAA, Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. NASA, Goddard Space Flight Ctr, Sci Lab & Visualizat Off, Greenbelt, MD 20771 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. Sci Applicat Int Corp, Beltsville, MD USA. RS Informat Syst, Mclean, VA USA. Joint Ctr Satellite Data Assimilat, Camp Springs, MD USA. NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RP Reale, O (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 613, Greenbelt, MD 20771 USA. EM oreste.reale-1@nasa.gov NR 14 TC 27 Z9 27 U1 0 U2 4 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 24 PY 2007 VL 34 IS 22 AR L22810 DI 10.1029/2007GL031640 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 235TP UT WOS:000251257500003 ER PT J AU Sergienko, OV MacAyeal, DR Bindschadler, RA AF Sergienko, O. V. MacAyeal, D. R. Bindschadler, R. A. TI Causes of sudden, short-term changes in ice-stream surface elevation SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTICA AB Recent satellite-borne observations of Antarctica's ice streams show sudden, spatially confined surface-elevation changes that are interpreted as caused by subglacial water movement. Using a numerical model of idealized ice-stream flow coupled to various simple treatments of subglacial bed conditions, we demonstrate that ice-stream flow dynamics significantly modulates the surface-elevation expression of processes taking place at the ice-stream bed. This modulation means that observed surface-elevation changes do not directly translate to basal-elevation changes, e. g. inflation or deflation of subglacial water pockets, of equal magnitude and shape. Thus, subglacial water volume change is not directly proportional to the area integral of surface-elevation changes. Model results show that ambiguities in interpretation of surface elevation changes can be overcome with additional measurements, such as of surface velocity change, and through development of methodology designed to understand transfer of basal change to surface change. C1 NASA, Oak Ridge Associated Univ, Goddard Space Flight Ctr, Biospher & Hydrospher Res Lab, Greenbelt, MD 20771 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sergienko, OV (reprint author), NASA, Oak Ridge Associated Univ, Goddard Space Flight Ctr, Biospher & Hydrospher Res Lab, Code 614,Bldg 33,Room A109, Greenbelt, MD 20771 USA. EM olga@neptune.gsfc.nasa.gov OI MacAyeal, Douglas/0000-0003-0647-6176 NR 8 TC 25 Z9 25 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 NOV 24 PY 2007 VL 34 IS 22 AR L22503 DI 10.1029/2007GL031775 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 235TP UT WOS:000251257500005 ER PT J AU Boyd, IS Parrish, AD Froidevaux, L von Clarmann, T Kyrola, E Russell, JM Zawodny, JM AF Boyd, Ian S. Parrish, Alan D. Froidevaux, Lucien von Clarmann, Thomas Kyrola, Erkki Russell, James M., III Zawodny, Joseph M. TI Ground-based microwave ozone radiometer measurements compared with Aura-MLS v2.2 and other instruments at two Network for Detection of Atmospheric Composition Change sites SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; STRATOSPHERIC OZONE; TRACE CONSTITUENTS; NEW-ZEALAND; VALIDATION; RETRIEVAL; PROFILES; TEMPERATURE; MESOSPHERE; SATELLITE AB [1] Ozone measurements made by the Microwave Limb Sounder (MLS) on board the Earth Observing System (EOS) Aura Satellite are compared with measurements made by ground-based microwave radiometers (MWR) in the Network for Detection of Atmospheric Composition Change (NDACC) stations at Lauder, New Zealand (45 degrees S, 169 degrees E) and Mauna Loa, Hawaii (20 degrees N, 204 degrees E). The latter instruments measure ozone over the pressure range 56 to 0.03 hPa ( about 20 to 72 km), allowing validation of ozone to the upper range of the MLS profiles. In addition, because they operate continuously, separate daytime and nighttime comparisons with MLS can be made to account for the large diurnal variations of ozone in the upper stratosphere and mesosphere. MLS-MWR comparisons show agreement generally within 5% between 24 and 0.04 hPa ( about 26 to 70 km) and 5 to 13% elsewhere. To more thoroughly investigate ozone in the stratosphere and mesosphere and establish a consensus between different sets of measurements, comparisons, and analyses with other satellite-borne instruments, including the Stratospheric Aerosol and Gas Experiment II (SAGE-II), Halogen Occultation Experiment (HALOE), Global Ozone Monitoring by Occultation of Stars (GOMOS), and Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), are also made, using the ground-based microwave measurements as a reference. The resulting MLS-consensus difference profiles remove some of the features present in the MLS-MWR comparisons and indicate that the overall agreement between MLS and the correlative data, between 56 and 0.04 hPa, is mostly within 5% at both sites. C1 Univ Massachusetts, NIWA Environm Res Inst, Amherst, MA 01003 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Forschungszentrum Karlsruhe, Inst Meteorol & Klimaforsch, D-76021 Karlsruhe, Germany. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. NASA Langley Res Ctr, Hampton, VA USA. RP Boyd, IS (reprint author), Univ Massachusetts, NIWA Environm Res Inst, 710 N Pleasant St, Amherst, MA 01003 USA. EM boyd@fcrao1.astro.umass.edu; parrish@astro.umass.edu; lucien.froidevaux@jpl.nasa.gov; thomas.clarmann@imk.fzk.de; erkki.kyrola@fmi.fi; james.russell@hamptonu.edu; joseph.m.zawodny@nasa.gov RI von Clarmann, Thomas/A-7287-2013; Kyrola, Erkki/E-1835-2014 OI von Clarmann, Thomas/0000-0003-2219-3379; NR 30 TC 22 Z9 23 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 24 PY 2007 VL 112 IS D24 AR D24S33 DI 10.1029/2007JD008720 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 235UR UT WOS:000251260300001 ER PT J AU Li, T She, CY Liu, HL Leblanc, T McDermid, IS AF Li, Tao She, C. -Y. Liu, Han-Li Leblanc, Thierry McDermid, I. Stuart TI Sodium lidar - observed strong inertia-gravity wave activities in the mesopause region over Fort Collins, Colorado ( 41 degrees N, 105 degrees W) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RADIOSONDE OBSERVATIONS; SPACED DATA; MU RADAR; STRATOSPHERE; TEMPERATURE; FLUCTUATIONS; VARIABILITY; MESOSPHERE; ATMOSPHERE; TURBULENCE AB In December 2004, the Colorado State University sodium lidar system at Fort Collins, Colorado ( 41 degrees N, 105 degrees W), conducted an similar to 80-hour continuous campaign for the simultaneous observations of mesopause region sodium density, temperature, and zonal and meridional winds. This data set reveals the significant inertia-gravity wave activities with a period of similar to 18 hours, which are strong in both wind components since UT day 338 ( second day of the campaign), and weak in temperature and sodium density. The considerable variability of wave activities was observed with both wind amplitudes growing up to similar to 40 m/s at 95 - 100 km in day 339 and then decreasing dramatically in day 340. We also found that the sodium density wave perturbation is correlated in phase with temperature perturbation below 90 km, and similar to 180 degrees out of phase above. Applying the linear wave theory, we estimated the wave horizontal propagation direction, horizontal wavelength, and apparent horizontal phase speed to be similar to 25 degrees south of west, similar to 1800 +/- 150 km, and similar to 28 +/- 2 m/s, respectively. The vertical profiles of wave intrinsic period, intrinsic phase speed, and vertical wavelength were also estimated. While the onset of enhanced inertia-gravity wave amplitude in the night of 338 was observed to be in coincidence with short-period gravity wave breaking via convective instability, the decrease of inertia-gravity wave amplitude after noon of day 339 was also observed to coincide with the development of atmospheric dynamical instability layers with downward phase progression clearly correlated with the 18-hour inertia-gravity wave, suggesting likely breaking of this inertia-gravity wave via dynamical ( shear) instability. C1 CALTECH, Jet Prop Lab, Table Mt Facil, Wrightwood, CA 92397 USA. Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. RP Li, T (reprint author), CALTECH, Jet Prop Lab, Table Mt Facil, 24490 Table Mt Rd,POB 367, Wrightwood, CA 92397 USA. EM taoli@tmf.jpl.nasa.gov RI Liu, Han-Li/A-9549-2008; Li, Tao/J-8950-2014 OI Liu, Han-Li/0000-0002-6370-0704; Li, Tao/0000-0002-5100-4429 NR 40 TC 10 Z9 10 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 24 PY 2007 VL 112 IS D22 AR D22104 DI 10.1029/2007JD008681 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 235UH UT WOS:000251259300002 ER PT J AU Laurel, J Stoner, AW Ryer, CH Hurst, TP Abookire, AA AF Laurel, J. Stoner, A. W. Ryer, C. H. Hurst, T. P. Abookire, A. A. TI Comparative habitat associations in juvenile Pacific cod and other gadids using seines, baited cameras and laboratory techniques SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE habitat selection; Kodiak island; predator risk; seagrass; spatial ecology ID ATLANTIC COD; GADUS-MORHUA; COMMUNITY REORGANIZATION; SUBSTRATE SELECTION; FISH COMMUNITIES; TEMPERATURE; ALASKA; SETTLEMENT; NEWFOUNDLAND; COMPLEXITY AB Pacific cod are commercially and ecologically important in the North Pacific, currently ranking 2nd in tonnage and value landed in the Alaskan groundfish fishery. To date, few studies have focused on the habitat requirements of Pacific cod, and as a result, our understanding of their ecology has largely been borrowed from better-studied gadid species, especially Atlantic cod. In July-Aug 2006, we used field and laboratory techniques to explicitly examine habitat associations of Pacific cod and two co-occurring gadids, saffron cod (Eleginus gracilis) and walleye Pollock (Theragra chalcogramma), in coastal areas around Kodiak Island, AK. Pacific cod were the most abundant gadid in seine collections, followed by saffron cod and walleye pollock respectively. Small Pacific cod (3.5-7.5 cm TL) were most highly associated with Laminaria and eelgrass beds but moved into open habitats at larger sizes i.e., >8.0 cm TL. Baited cameras indicated that the majority of juvenile Pacific cod were nearshore in August (i.e., <= 4.5 m), but schools were also seen in deeper (6.0-13.5 m), unstructured habitats. In contrast., age-0 saffron cod were almost exclusively restricted to eelgrass beds (Zostera marina) (3.5-13.0 cm) as were later year-classes i.e., 18-50 cm. Pollock were highly variable in their distribution, and were almost absent from the nearshore in late August. In 2 in experimental aquaria, Pacific and saffron cod chose macrophyte habitats under increased predation risk but also associated with these habitats at larger scales (i.e., c. 10 m tank) in the absence of a predator. Our results indicate both distinct differences and parallels between Pacific and Atlantic cod that will guide future process-oriented habitat research in both species. Published by Elsevier B.V. C1 NOAA, Hatfield Marine Sci Ctr, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv,Fisheries Behavior Eco, Newport, OR 97365 USA. NOAA, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Kodiak Lab, Kodiak, AK 99615 USA. RP Laurel, J (reprint author), NOAA, Hatfield Marine Sci Ctr, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv,Fisheries Behavior Eco, Newport, OR 97365 USA. EM ben.laurel@noaa.gov RI Bizzarro, Joseph/A-2988-2012; Hurst, Thomas/N-1401-2013 NR 54 TC 13 Z9 13 U1 3 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD NOV 23 PY 2007 VL 351 IS 1-2 BP 42 EP 55 DI 10.1016/j.jembe.2007.06.005 PG 14 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 220JG UT WOS:000250152400005 ER PT J AU Fabrizio, MC Pessutti, JP AF Fabrizio, Mary C. Pessutti, Jeffrey P. TI Long-term effects and recovery from surgical implantation of dummy transmitters in two marine fishes SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE acoustic transmitters; black sea bass; clove oil; growth; summer flounder; surgical implantation ID CLOVE OIL; TELEMETRY TRANSMITTERS; RAINBOW-TROUT; TRANSINTESTINAL EXPULSION; CHANNEL CATFISH; STRIPED BASS; HOME-RANGE; SEA-BASS; GROWTH; MORTALITY AB We surgically implanted black sea bass and summer flounder with dummy transmitters and monitored recovery, survival, and growth during an 11-month post-operative period. We also examined transmitter retention rates as neither species had been previously implanted with transmitters. Recovery time from surgery and anesthesia was significantly greater than recovery time from anesthesia alone for black sea bass, but this relation was not observed for summer flounder. Summer flounder recovery times were highly variable, but in general, smaller fish had longer recovery times. All black sea bass and summer flounder retained their surgically implanted transmitter at least 11 months and had high survival rates in laboratory trials (black sea bass survival, 97.9%; summer flounder survival, 94.6%). Nonparametric analyses of covariance using initial size as the covariate indicated that black sea bass exhibited no significant detrimental growth effects after 11 months, but significantly slower growth was observed for summer flounder (this was especially pronounced in the larger [>800 g] fish). Surgical implantation of acoustic transmitters in these species can be used to conduct long-term field studies of habitat use and movements because fish exhibited high survival rates and 100% retention of transmitters. (C) 2007 Elsevier B.V. All rights reserved. C1 NOAA, NE Fisheries Ctr, Natl Marine Fisheries Serv, Highlands, NJ 07732 USA. RP Fabrizio, MC (reprint author), NOAA, NE Fisheries Ctr, Natl Marine Fisheries Serv, 74 Magruder Rd, Highlands, NJ 07732 USA. EM mfabrizio@vims.edu OI Fabrizio, Mary/0000-0002-6115-5490 NR 43 TC 18 Z9 18 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD NOV 23 PY 2007 VL 351 IS 1-2 BP 243 EP 254 DI 10.1016/j.jembe.2007.06.031 PG 12 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 220JG UT WOS:000250152400023 ER PT J AU Aslam, S Miko, L Stahle, C Franz, D Pugel, D Guan, B Zhang, JP Gaska, R AF Aslam, S. Miko, L. Stahle, C. Franz, D. Pugel, D. Guan, B. Zhang, J. P. Gaska, R. TI Dua-band deep ultraviolet AlGaN photodetectors SO ELECTRONICS LETTERS LA English DT Article ID FOCAL-PLANE ARRAYS AB The design, fabrication and characterisation of a back-illuminated voltage bias selectable dual-band AlGaN UV photodetector are reported. The photodetector can separate UV-A and UV-B band radiation by bias switching a two-terminal n-p-n homejunction structure that is fabricated in the same pixel. When a forward bias is applied between the top and bottom electrodes, the detector can sense UV-A (315-400 nm) and reject UV-B (280-315 nm) band radiation. Alternatively, under reverse bias, the photodetector can sense UV-B and reject UV-A band radiation. C1 [Aslam, S.; Miko, L.; Stahle, C.; Franz, D.; Pugel, D.; Guan, B.] NASA, Goddard Space Flight Ctr, Detector Syst Branch, Greenbelt, MD 20771 USA. [Zhang, J. P.; Gaska, R.] Sensor Elect Technol Inc, Columbia, SC 29209 USA. RP Aslam, S (reprint author), NASA, Goddard Space Flight Ctr, Detector Syst Branch, Code 553, Greenbelt, MD 20771 USA. EM saslam@pop200.gsfc.nasa.gov RI Aslam, Shahid/D-1099-2012 NR 7 TC 0 Z9 1 U1 3 U2 8 PU INST ENGINEERING TECHNOLOGY-IET PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD NOV 22 PY 2007 VL 43 IS 24 BP 1382 EP 1384 DI 10.1049/el:20072579 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 248VJ UT WOS:000252184800039 ER PT J AU Cable, TL Sofie, SW AF Cable, Thomas L. Sofie, Stephen W. TI A symmetrical, planar SOFC design for NASN ' s high specific power density requirements SO JOURNAL OF POWER SOURCES LA English DT Article DE SOFC; electrode supported; symmetrical; electrode infiltration ID FUEL-CELLS AB Solid oxide fuel cell (SOFC) systems for aircraft applications require an order of magnitude increase in specific power density (1.0 kW kg(-1)) and long life. While significant research is underway to develop anode supported cells which operate at temperatures in the range of 650-800 degrees C, concerns about Cr-contamination from the metal interconnect may drive the operating temperature down further, to 750 degrees C and lower. Higher temperatures, 850-1000 degrees C, are more favorable in order to achieve specific power densities of 1.0 kWkg(-1). Since metal interconnects are not practical at these high temperatures and can account for up to 75% of the weight of the stack, NASA is pursuing a design that uses a thin, LaCrO3-based ceramic interconnect that incorporates gas channels into the electrodes. The bi-electrode supported cell (BSC) uses porous YSZ scaffolds, on either side of a 10-20 mu m electrolyte. The porous Support regions are fabricated with graded porosity using the freeze-tape casting process which can be tailored for fuel and air flow. Removing gas channels from the interconnect simplifies the stack design and allows the ceramic interconnect to be kept thin, on the order of 50-100 mu m. The YSZ electrode scaffolds are infiltrated with active electrode materials following the high-temperature sintering step. The NASA-BSC is symmetrical and CTE matched, providing balanced stresses and favorable mechanical properties for vibration and thermal cycling. (C) 2007 Elsevier B.V. All rights reserved. C1 [Cable, Thomas L.] Univ Toledo, Cleveland, OH 44135 USA. [Sofie, Stephen W.] NASA, Glenn Res Ctr, QSS, Cleveland, OH 44135 USA. RP Cable, TL (reprint author), Univ Toledo, 21000 Brookpk Rd,MS106-1, Cleveland, OH 44135 USA. EM Thomas.L.Cible@nasa.gov NR 13 TC 50 Z9 50 U1 5 U2 28 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD NOV 22 PY 2007 VL 174 IS 1 BP 221 EP 227 DI 10.1016/j.jpowsour.2007.08.110 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 240MF UT WOS:000251591000027 ER PT J AU Debaille, V Brandon, AD Yin, QZ Jacobsen, B AF Debaille, V. Brandon, A. D. Yin, Q. Z. Jacobsen, B. TI Coupled Nd-142-Nd-143 evidence for a protracted magma ocean in Mars SO NATURE LA English DT Article ID ND ISOTOPIC SYSTEMATICS; MARTIAN METEORITES; EARLY DIFFERENTIATION; SNC METEORITES; SM-ND; CORE FORMATION; EARTHS MANTLE; RB-SR; CONSTRAINTS; EVOLUTION AB Resolving early silicate differentiation timescales is crucial for understanding the chemical evolution and thermal histories of terrestrial planets(1). Planetary-scale magma oceans are thought to have formed during early stages of differentiation, but the longevity of such magma oceans is poorly constrained. In Mars, the absence of vigorous convection and plate tectonics has limited the scale of compositional mixing within its interior(2), thus preserving the early stages of planetary differentiation. The SNC ( Shergotty-Nakhla-Chassigny) meteorites from Mars retain 'memory' of these events(3-5). Here we apply the short-lived Sm-146-Nd-142 and the long-lived Sm-147-Nd-143 chronometers to a suite of shergottites to unravel the history of early silicate differentiation in Mars. Our data are best explained by progressive crystallization of a magma ocean with a duration of similar to 100 million years after core formation. This prolonged solidification requires the existence of a primitive thick atmosphere on Mars that reduces the cooling rate of the interior(6) . C1 Lunar & Planetary Inst, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Calif Davis, Dept Geol, Davis, CA 95616 USA. RP Debaille, V (reprint author), Lunar & Planetary Inst, 3600 Bay Area Blvd, Houston, TX 77058 USA. EM debaille@lpi.usra.edu RI Yin, Qing-Zhu/B-8198-2009 OI Yin, Qing-Zhu/0000-0002-4445-5096 NR 32 TC 96 Z9 98 U1 1 U2 20 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 22 PY 2007 VL 450 IS 7169 BP 525 EP 528 DI 10.1038/nature06317 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 234JW UT WOS:000251158500041 PM 18033291 ER PT J AU Qin, Z Denton, RE Tsyganenko, NA Wolf, S AF Qin, Z. Denton, R. E. Tsyganenko, N. A. Wolf, S. TI Solar wind parameters for magnetospheric magnetic field modeling SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS LA English DT Article ID DAWN-DUSK ASYMMETRY; INNER MAGNETOSPHERE; ART. AB Magnetospheric magnetic field models are crucial for many space weather applications. However, the latest empirical models require solar wind and IMF data, which are not always available. Data gaps are especially common for times before the launch of the WIND spacecraft at the end of 1994, but even after then there are data gaps. We present a method to interpolate the solar wind characteristics across data gaps and to evaluate the W parameters needed for the TS05 model (Tsyganenko and Sitnov, 2005). Within some distance from the edge of a data gap, the solar wind parameters from our method yield a better estimate of the observed magnetic field than that which could be found using average values of the parameters. Deep within data gaps (far from measured values), the interpolated parameters are reasonable, or typical values, no better or worse than average values. We have created a database of hourly data with solar wind characteristics, G, and W parameters from 1963 to 31 May 2007, which is sufficient for use in all the Tsyganenko models, including the latest TS05 model. Our comparisons of the model and observed magnetic field at geosynchronous orbit give an estimate of the error in the model field as a function of status parameters defined by the interpolation scheme. We also show that the model field is on average just as accurate using the hourly data as that based on 5 min data (at least at geosynchronous orbit). C1 [Qin, Z.; Denton, R. E.] Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA. [Tsyganenko, N. A.] NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. [Wolf, S.] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. RP Qin, Z (reprint author), Dartmouth Coll, Dept Phys & Astron, 6127 Wilder Lab, Hanover, NH 03755 USA. EM zhengrui.qin@dartmouth.edu; richard.e.denton@dartmouth.edu RI Tsyganenko, Nikolai/J-7377-2012 OI Tsyganenko, Nikolai/0000-0002-5938-1579 NR 11 TC 29 Z9 29 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1542-7390 J9 SPACE WEATHER JI Space Weather PD NOV 22 PY 2007 VL 5 IS 11 AR S11003 DI 10.1029/2006SW000296 PG 11 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 261JX UT WOS:000253076000001 ER PT J AU Abbott, B Abbott, R Adhikari, R Agresti, J Ajith, P Allen, B Amin, R Anderson, SB Anderson, WG Arain, M Araya, M Armandula, H Ashley, M Aston, S Aufmuth, P Aulbert, C Babak, S Ballmer, S Bantilan, H Barish, BC Barker, C Barker, D Barr, B Barriga, P Barton, MA Bayer, K Belczynski, K Betzwieser, J Beyersdorf, PT Bhawal, B Bilenko, IA Billingsley, G Biswas, R Black, E Blackburn, K Blackburn, L Blair, D Bland, B Bogenstahl, J Bogue, L Bork, R Boschi, V Bose, S Brady, PR Braginsky, VB Brau, JE Brinkmann, M Brooks, A Brown, DA Bullington, A Bunkowski, A Buonanno, A Burmeister, O Busby, D Byer, RL Cadonati, L Cagnoli, G Camp, JB Cannizzo, J Cannon, K Cantley, CA Cao, J Cardenas, L Casey, MM Castaldi, G Cepeda, C Chalkey, E Charlton, P Chatterji, S Chelkowski, S Chen, Y Chiadini, F Chin, D Chin, E Chow, J Christensen, N Clark, J Cochrane, P Cokelaer, T Colacino, CN Coldwell, R Conte, R Cook, D Corbitt, T Coward, D Coyne, D Creighton, JDE Creighton, TD Croce, RP Crooks, DRM Cruise, AM Cumming, A Dalrymple, J D'Ambrosio, E Danzmann, K Davies, G Debra, D Degallaix, J Degree, M Demma, T Dergachev, V Desai, S DeSalvo, R Dhurandhar, S Diaz, M Dickson, J Di Credico, A Diederichs, G Dietz, A Doomes, EE Drever, RWP Dumas, JC Dupuis, RJ Dwyer, JG Ehrens, P Espinoza, E Etzel, T Evans, M Evans, T Fairhurst, S Fan, Y Fazi, D Fejer, MM Finn, LS Fiumara, V Fotopoulos, N Franzen, A Franzen, KY Freise, A Frey, R Fricke, T Fritschel, P Frolov, VV Fyffe, M Galdi, V Garofoli, J Gholami, I Giaime, JA Giampanis, S Giardina, KD Goda, K Goetz, E Goggin, LM Gonzalez, G Gossler, S Grant, A Gras, S Gray, C Gray, M Greenhalgh, J Gretarsson, AM Grosso, R Grote, H Grunewald, S Guenther, M Gustafson, R Hage, B Hammer, D Hanna, C Hanson, J Harms, J Harry, G Harstad, E Hayler, T Heefner, J Heng, IS Heptonstall, A Heurs, M Hewitson, M Hild, S Hirose, E Hoak, D Hosken, D Hough, J Howell, E Hoyland, D Huttner, SH Ingram, D Innerhofer, E Ito, M Itoh, Y Ivanov, A Jackrel, D Johnson, B WJohnson, W Jones, DI Jones, G Jones, R Ju, L Kalmus, P Kalogera, V Kasprzyk, D Katsavounidis, E Kawabe, K Kawamura, S Kawazoe, F Kells, W Keppel, DG Khalili, FY Kim, C King, P Kissel, JS Klimenko, S Kokeyama, K Kondrashov, V Kopparapu, RK Kozak, D Krishnan, B Kwee, P Lam, PK Landry, M Lantz, B Lazzarini, A Lee, B Lei, M Leiner, J Leonhardt, V Leonor, I Libbrecht, K Lindquist, P Lockerbie, NA Longo, M Lormand, M Lubinski, M Luck, H Machenschalk, B MacInnis, M Mageswaran, M Mailand, K Malec, M Mandic, V Marano, S Marka, S Markowitz, J Maros, E Martin, I Marx, JN Mason, K Matone, L Matta, V Mavalvala, N McCarthy, R McClelland, DE McGuire, SC McHugh, M McKenzie, K McNabb, JWC McWilliams, S Meier, T Melissinos, A Mendell, G Mercer, RA Meshkov, S Messaritaki, E Messenger, CJ Meyers, D Mikhailov, E Mitra, S Mitrofanov, VP Mitselmakher, G Mittleman, R Miyakawa, O Mohanty, S Moreno, G Mossavi, K MowLowry, C Moylan, A Mudge, D Mueller, G Mukherjee, S Muller-Ebhardt, H Munch, J Murray, P Myers, E Myers, J Nash, T Newton, G Nishizawa, A Numata, K O'Reilly, B O'Shaughnessy, R Ottaway, DJ Overmier, H Owen, BJ Pan, Y Papa, MA Parameshwaraiah, V Patel, P Pedraza, M Pelc, J Penn, S Pierro, V Pinto, IM Pitkin, M Pletsch, H Plissi, MV Postiglione, F Prix, R Quetschke, V Raab, F Rabeling, D Radkins, H Rahkola, R Rainer, N Rakhmanov, M Ramsunder, M Rawlins, K Ray-Majumder, S Re, V Rehbein, H Reid, S Reitze, DH Ribichini, L Riesen, R Riles, K Rivera, B Robertson, NA Robinson, C Robinson, EL Roddy, S Rodriguez, A Rogan, AM Rollins, J Romano, JD Romie, J Route, R Rowan, S Rudiger, A Ruet, L Russell, P Ryan, K Sakata, S Samidi, M de la Jordana, LS Sandberg, V Sannibale, V Saraf, S Sarin, P Sathyaprakash, BS Sato, S Saulson, PR Savage, R Savov, P Schediwy, S Schilling, R Schnabel, R Schofield, R Schutz, BF Schwinberg, P Scott, SM Searle, AC Sears, B Seifert, F Sellers, D Sengupta, AS Shawhan, P Shoemaker, DH Sibley, A Sidles, JA Siemens, X Sigg, D Sinha, S Sintes, AM Slagmolen, BJJ Slutsky, J Smith, JR Smith, MR Somiya, K Strain, KA Strom, DM Stuver, A Summerscales, TZ Sun, KX Sung, M Sutton, PJ Takahashi, H Tanner, DB Tarallo, M Taylor, R Taylor, R Thacker, J Thorne, KA Thorne, KS Thuring, A Tinto, M Tokmakov, KV Torres, C Torrie, C Traylor, G Trias, M Tyler, W Ugolini, D Ungarelli, C Urbanek, K Vahlbruch, H Vallisneri, M Van Den Broeck, C Varvella, M Vass, S Vecchio, A Veitch, J Veitch, P Villar, A Vorvick, C Vyachanin, SP Waldman, SJ Wallace, L Ward, H Ward, R Watts, K Webber, D Weidner, A Weinert, M Weinstein, A Weiss, R Wen, S Wette, K Whelan, JT Whitbeck, DM EWhitcomb, S FWhiting, B Wilkinson, C Willems, PA Willems, L Williams, L Willke, B Wilmut, I Winkler, W Wipf, CC Wise, S Wiseman, AG Woan, G Woods, D Wooley, R Worden, J Wu, W Yakushin, I Yamamoto, H Yan, Z Yoshida, S Yunes, N Zanolin, M Zhang, J Zhang, L Zhao, C Zotov, N Zucker, M zur Muhlen, H Zweizig, J AF Abbott, B. Abbott, R. Adhikari, R. Agresti, J. Ajith, P. Allen, B. Amin, R. Anderson, S. B. Anderson, W. G. Arain, M. Araya, M. Armandula, H. Ashley, M. Aston, S. Aufmuth, P. Aulbert, C. Babak, S. Ballmer, S. Bantilan, H. Barish, B. C. Barker, C. Barker, D. Barr, B. Barriga, P. Barton, M. A. Bayer, K. Belczynski, K. Betzwieser, J. Beyersdorf, P. T. Bhawal, B. Bilenko, I. A. Billingsley, G. Biswas, R. Black, E. Blackburn, K. Blackburn, L. Blair, D. Bland, B. Bogenstahl, J. Bogue, L. Bork, R. Boschi, V. Bose, S. Brady, P. R. Braginsky, V. B. Brau, J. E. Brinkmann, M. Brooks, A. Brown, D. A. Bullington, A. Bunkowski, A. Buonanno, A. Burmeister, O. Busby, D. Byer, R. L. Cadonati, L. Cagnoli, G. Camp, J. B. Cannizzo, J. Cannon, K. Cantley, C. A. Cao, J. Cardenas, L. Casey, M. M. Castaldi, G. Cepeda, C. Chalkey, E. Charlton, P. Chatterji, S. Chelkowski, S. Chen, Y. Chiadini, F. Chin, D. Chin, E. Chow, J. Christensen, N. Clark, J. Cochrane, P. Cokelaer, T. Colacino, C. N. Coldwell, R. Conte, R. Cook, D. Corbitt, T. Coward, D. Coyne, D. Creighton, J. D. E. Creighton, T. D. Croce, R. P. Crooks, D. R. M. Cruise, A. M. Cumming, A. Dalrymple, J. D'Ambrosio, E. Danzmann, K. Davies, G. Debra, D. Degallaix, J. Degree, M. Demma, T. Dergachev, V. Desai, S. DeSalvo, R. Dhurandhar, S. Diaz, M. Dickson, J. Di Credico, A. Diederichs, G. Dietz, A. Doomes, E. E. Drever, R. W. P. Dumas, J-C Dupuis, R. J. Dwyer, J. G. Ehrens, P. Espinoza, E. Etzel, T. Evans, M. Evans, T. Fairhurst, S. Fan, Y. Fazi, D. Fejer, M. M. Finn, L. S. Fiumara, V. Fotopoulos, N. Franzen, A. Franzen, K. Y. Freise, A. Frey, R. Fricke, T. Fritschel, P. Frolov, V. V. Fyffe, M. Galdi, V. Garofoli, J. Gholami, I. Giaime, J. A. Giampanis, S. Giardina, K. D. Goda, K. Goetz, E. Goggin, L. M. Gonzalez, G. Gossler, S. Grant, A. Gras, S. Gray, C. Gray, M. Greenhalgh, J. Gretarsson, A. M. Grosso, R. Grote, H. Grunewald, S. Guenther, M. Gustafson, R. Hage, B. Hammer, D. Hanna, C. Hanson, J. Harms, J. Harry, G. Harstad, E. Hayler, T. Heefner, J. Heng, I. S. Heptonstall, A. Heurs, M. Hewitson, M. Hild, S. Hirose, E. Hoak, D. Hosken, D. Hough, J. Howell, E. Hoyland, D. Huttner, S. H. Ingram, D. Innerhofer, E. Ito, M. Itoh, Y. Ivanov, A. Jackrel, D. Johnson, B. WJohnson, W. Jones, D. I. Jones, G. Jones, R. Ju, L. Kalmus, P. Kalogera, V. Kasprzyk, D. Katsavounidis, E. Kawabe, K. Kawamura, S. Kawazoe, F. Kells, W. Keppel, D. G. Khalili, F. Ya Kim, C. King, P. Kissel, J. S. Klimenko, S. Kokeyama, K. Kondrashov, V. Kopparapu, R. K. Kozak, D. Krishnan, B. Kwee, P. Lam, P. K. Landry, M. Lantz, B. Lazzarini, A. Lee, B. Lei, M. Leiner, J. Leonhardt, V. Leonor, I. Libbrecht, K. Lindquist, P. Lockerbie, N. A. Longo, M. Lormand, M. Lubinski, M. Luck, H. Machenschalk, B. MacInnis, M. Mageswaran, M. Mailand, K. Malec, M. Mandic, V. Marano, S. Marka, S. Markowitz, J. Maros, E. Martin, I. Marx, J. N. Mason, K. Matone, L. Matta, V. Mavalvala, N. McCarthy, R. McClelland, D. E. McGuire, S. C. McHugh, M. McKenzie, K. McNabb, J. W. C. McWilliams, S. Meier, T. Melissinos, A. Mendell, G. Mercer, R. A. Meshkov, S. Messaritaki, E. Messenger, C. J. Meyers, D. Mikhailov, E. Mitra, S. Mitrofanov, V. P. Mitselmakher, G. Mittleman, R. Miyakawa, O. Mohanty, S. Moreno, G. Mossavi, K. MowLowry, C. Moylan, A. Mudge, D. Mueller, G. Mukherjee, S. Muller-Ebhardt, H. Munch, J. Murray, P. Myers, E. Myers, J. Nash, T. Newton, G. Nishizawa, A. Numata, K. O'Reilly, B. O'Shaughnessy, R. Ottaway, D. J. Overmier, H. Owen, B. J. Pan, Y. Papa, M. A. Parameshwaraiah, V. Patel, P. Pedraza, M. Pelc, J. Penn, S. Pierro, V. Pinto, I. M. Pitkin, M. Pletsch, H. Plissi, M. V. Postiglione, F. Prix, R. Quetschke, V. Raab, F. Rabeling, D. Radkins, H. Rahkola, R. Rainer, N. Rakhmanov, M. Ramsunder, M. Rawlins, K. Ray-Majumder, S. Re, V. Rehbein, H. Reid, S. Reitze, D. H. Ribichini, L. Riesen, R. Riles, K. Rivera, B. Robertson, N. A. Robinson, C. Robinson, E. L. Roddy, S. Rodriguez, A. Rogan, A. M. Rollins, J. Romano, J. D. Romie, J. Route, R. Rowan, S. Rudiger, A. Ruet, L. Russell, P. Ryan, K. Sakata, S. Samidi, M. de la Jordana, L. Sancho Sandberg, V. Sannibale, V. Saraf, S. Sarin, P. Sathyaprakash, B. S. Sato, S. Saulson, P. R. Savage, R. Savov, P. Schediwy, S. Schilling, R. Schnabel, R. Schofield, R. Schutz, B. F. Schwinberg, P. Scott, S. M. Searle, A. C. Sears, B. Seifert, F. Sellers, D. Sengupta, A. S. Shawhan, P. Shoemaker, D. H. Sibley, A. Sidles, J. A. Siemens, X. Sigg, D. Sinha, S. Sintes, A. M. Slagmolen, B. J. J. Slutsky, J. Smith, J. R. Smith, M. R. Somiya, K. Strain, K. A. Strom, D. M. Stuver, A. Summerscales, T. Z. Sun, K-X Sung, M. Sutton, P. J. Takahashi, H. Tanner, D. B. Tarallo, M. Taylor, R. Taylor, R. Thacker, J. Thorne, K. A. Thorne, K. S. Thuring, A. Tinto, M. Tokmakov, K. V. Torres, C. Torrie, C. Traylor, G. Trias, M. Tyler, W. Ugolini, D. Ungarelli, C. Urbanek, K. Vahlbruch, H. Vallisneri, M. Van Den Broeck, C. Varvella, M. Vass, S. Vecchio, A. Veitch, J. Veitch, P. Villar, A. Vorvick, C. Vyachanin, S. P. Waldman, S. J. Wallace, L. Ward, H. Ward, R. Watts, K. Webber, D. Weidner, A. Weinert, M. Weinstein, A. Weiss, R. Wen, S. Wette, K. Whelan, J. T. Whitbeck, D. M. EWhitcomb, S. FWhiting, B. Wilkinson, C. Willems, P. A. Willems, L. Williams, L. Willke, B. Wilmut, I. Winkler, W. Wipf, C. C. Wise, S. Wiseman, A. G. Woan, G. Woods, D. Wooley, R. Worden, J. Wu, W. Yakushin, I. Yamamoto, H. Yan, Z. Yoshida, S. Yunes, N. Zanolin, M. Zhang, J. Zhang, L. Zhao, C. Zotov, N. Zucker, M. zur Muehlen, H. Zweizig, J. TI Search for gravitational-wave bursts in LIGO data from the fourth science run SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID CORE-COLLAPSE; DETECTORS; EXPLORER; NAUTILUS; VIRGO AB The fourth science run of the LIGO and GEO 600 gravitational-wave detectors, carried out in early 2005, collected data with significantly lower noise than previous science runs. We report on a search for short-duration gravitational-wave bursts with arbitrary waveform in the 64-1600 Hz frequency range appearing in all three LIGO interferometers. Signal consistency tests, data quality cuts and auxiliary-channel vetoes are applied to reduce the rate of spurious triggers. No gravitational-wave signals are detected in 15.5 days of live observation time; we set a frequentist upper limit of 0.15 day(-1) ( at 90% confidence level) on the rate of bursts with large enough amplitudes to be detected reliably. The amplitude sensitivity of the search, characterized using Monte Carlo simulations, is several times better than that of previous searches. We also provide rough estimates of the distances at which representative supernova and binary black hole merger signals could be detected with 50% efficiency by this analysis. C1 CALTECH, LIGO, Pasadena, CA 91125 USA. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-30167 Hannover, Germany. Univ Wisconsin, Milwaukee, WI 53201 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Univ Florida, Gainesville, FL 32611 USA. Australian Natl Univ, Canberra, ACT 0200, Australia. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Leibniz Univ Hannover, D-30167 Hannover, Germany. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. Carleton Coll, Northfield, MN 55057 USA. Hanford Observ, LIGO, Richland, WA 99352 USA. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Univ Western Australia, Nedlands, WA 6009, Australia. MIT, LIGO, Cambridge, MA 02139 USA. Northwestern Univ, Evanston, IL 60208 USA. San Jose State Univ, San Jose, CA 95192 USA. Moscow MV Lomonosov State Univ, Moscow 119992, Russia. Livingston Observ, LIGO, Livingston, LA 70754 USA. Washington State Univ, Pullman, WA 99164 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Adelaide, Adelaide, SA 5005, Australia. Caltech CaRT, Pasadena, CA 91125 USA. Stanford Univ, Stanford, CA 94305 USA. Univ Maryland, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Sanniio Benevento, I-82100 Benevento, Italy. Charles Sturt Univ, Wagga Wagga, NSW 2678, Australia. Univ Salerno, I-84084 Salerno, Italy. Univ Michigan, Ann Arbor, MI 48109 USA. Cardiff Univ, Cardiff CF24 3AA, Wales. Syracuse Univ, Syracuse, NY 13244 USA. Penn State Univ, University Pk, PA 16802 USA. Inter Univ Ctr Astron & Astrophys, Pune 41007, Maharashtra, India. Univ Texas Brownsville, Texas Southmost Coll, Brownsville, TX 78520 USA. So Univ A&M Coll, Baton Rouge, LA 70813 USA. CALTECH, Pasadena, CA 91125 USA. Columbia Univ, New York, NY 10027 USA. Univ Rochester, Rochester, NY 14627 USA. Rutherford Appleton Lab, Chilton OX11 0QX, England. Embry Riddle Aeronaut Univ, Prescott, AZ 86301 USA. Univ Southampton, Southampton SO17 1BJ, Hants, England. Natl Astron Observ, Tokyo 1818588, Japan. Univ Strathclyde, Glasgow G1 1XQ, Lanark, Scotland. Loyola Univ, New Orleans, LA 70118 USA. Hobart & William Smith Coll, Geneva, NY 14456 USA. Univ Illes Balears, Dept Fis, E-07122 Palma de Mallorca, Spain. Rochester Inst Technol, Rochester, NY 14623 USA. Univ Washington, Seattle, WA 98195 USA. Andrews Univ, Berrien Springs, MI 49104 USA. Trinity Univ, San Antonio, TX 78212 USA. SE Louisiana Univ, Hammond, LA 70402 USA. Louisiana State Univ, Ruston, LA 71272 USA. RP Abbott, B (reprint author), CALTECH, LIGO, Pasadena, CA 91125 USA. RI Freise, Andreas/F-8892-2011; Kawabe, Keita/G-9840-2011; Finn, Lee Samuel/A-3452-2009; Pelc, Jason/F-3258-2012; Agresti, Juri/G-8168-2012; Mitrofanov, Valery/D-8501-2012; Bilenko, Igor/D-5172-2012; Allen, Bruce/K-2327-2012; Chen, Yanbei/A-2604-2013; Barker, David/A-5671-2013; Ju, Li/C-2623-2013; Pitkin, Matthew/I-3802-2013; Vyatchanin, Sergey/J-2238-2012; Lueck, Harald/F-7100-2011; Kawazoe, Fumiko/F-7700-2011; Barriga, Pablo/A-3929-2008; Lam, Ping Koy/A-5276-2008; Galdi, Vincenzo/B-1670-2008; McClelland, David/E-6765-2010; Martin, Iain/A-2445-2010; Hild, Stefan/A-3864-2010; Schutz, Bernard/B-1504-2010; Casey, Morag/C-9703-2010; Rowan, Sheila/E-3032-2010; Strain, Kenneth/D-5236-2011; Raab, Frederick/E-2222-2011; Chow, Jong/A-3183-2008; Frey, Raymond/E-2830-2016; Ward, Robert/I-8032-2014; Khalili, Farit/D-8113-2012; Chiadini, Francesco/E-1812-2015; Vecchio, Alberto/F-8310-2015; Mow-Lowry, Conor/F-8843-2015; Ottaway, David/J-5908-2015; Postiglione, Fabio/O-4744-2015; Howell, Eric/H-5072-2014; Messaritaki, Eirini/D-7393-2016; Biswas, Rahul/H-7474-2016; Tarallo, Marco/B-2096-2012; Sigg, Daniel/I-4308-2015; Pinto, Innocenzo/L-3520-2016; Harms, Jan/J-4359-2012; OI Boschi, Valerio/0000-0001-8665-2293; Pinto, Innocenzo M./0000-0002-2679-4457; Nishizawa, Atsushi/0000-0003-3562-0990; Zweizig, John/0000-0002-1521-3397; O'Shaughnessy, Richard/0000-0001-5832-8517; Finn, Lee Samuel/0000-0002-3937-0688; Agresti, Juri/0000-0001-6119-2470; Allen, Bruce/0000-0003-4285-6256; Pitkin, Matthew/0000-0003-4548-526X; Lueck, Harald/0000-0001-9350-4846; Lam, Ping Koy/0000-0002-4421-601X; Galdi, Vincenzo/0000-0002-4796-3600; McClelland, David/0000-0001-6210-5842; Strain, Kenneth/0000-0002-2066-5355; Chow, Jong/0000-0002-2414-5402; Frey, Raymond/0000-0003-0341-2636; LONGO, Maurizio/0000-0001-8325-4003; Pierro, Vincenzo/0000-0002-6020-5521; Ward, Robert/0000-0001-5503-5241; Whelan, John/0000-0001-5710-6576; Fairhurst, Stephen/0000-0001-8480-1961; Chiadini, Francesco/0000-0002-9339-8622; Vecchio, Alberto/0000-0002-6254-1617; Postiglione, Fabio/0000-0003-0628-3796; Howell, Eric/0000-0001-7891-2817; Biswas, Rahul/0000-0002-0774-8906; Tarallo, Marco/0000-0001-5169-4987; Sigg, Daniel/0000-0003-4606-6526; Aulbert, Carsten/0000-0002-1481-8319; Freise, Andreas/0000-0001-6586-9901; MATTA, VINCENZO/0000-0002-2046-4027; MARANO, Stefano/0000-0002-5307-0980; Whiting, Bernard F/0000-0002-8501-8669; Veitch, John/0000-0002-6508-0713; Papa, M.Alessandra/0000-0002-1007-5298 NR 39 TC 70 Z9 70 U1 2 U2 14 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 NOV 21 PY 2007 VL 24 IS 22 BP 5343 EP 5369 DI 10.1088/0264-9381/24/22/002 PG 27 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 238DV UT WOS:000251428400002 ER PT J AU Xia, XG Li, ZQ Holben, B Wang, P Eck, T Chen, HB Cribb, M Zhao, YX AF Xia, Xiangao Li, Zhanqing Holben, Brent Wang, Pucai Eck, Tom Chen, Hongbin Cribb, Maureen Zhao, Yanxia TI Aerosol optical properties and radiative effects in the Yangtze Delta region of China SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTHERN CHINA; CLIMATE; NETWORK; AERONET; INSTRUMENTATION; VARIABILITY; ASSESSMENTS; ABSORPTION; ATMOSPHERE; PRODUCTS AB One year's worth of aerosol and surface irradiance data from September 2005 to August 2006 were obtained at Taihu, the second supersite for the East Asian Study of Tropospheric Aerosols: An International Regional Experiment (EAST-AIRE). Aerosol optical properties derived from measurements by a Sun photometer were analyzed. The aerosol data were used together with surface irradiance data to quantitatively estimate aerosol effects on surface shortwave radiation (SWR) and photosynthetically active radiation ( PAR). The annual mean aerosol optical depth at 500 nm is 0.77, and mean Angstrom wavelength exponent is 1.17. The annual mean aerosol single scattering albedo and mean aerosol asymmetry factor at 440 nm are 0.90 and 0.72, respectively. Both parameters show a weak seasonal variation, with small values occurring during the winter and larger values during the summer. Clear positive relationships between relative humidity and aerosol properties suggest aerosol hygroscopic growth greatly modifies aerosol properties. The annual mean aerosol direct radiative forcing at the surface (ADRF) is -38.4 W m(-2) and -17.8 W m(-2) for SWR and PAR, respectively. Because of moderate absorption, the instantaneous ADRF at the top of the atmosphere derived from CERES SSF data is close to zero. Heavy aerosol loading in this region leads to -112.6 W m(-2) and -45.5 W m(-2) reduction in direct and global SWR, but 67.1 W m(-2) more diffuse SWR reaching the surface. With regard to PAR, the annual mean differences in global, direct and diffuse irradiance are -23.1 W m(-2), -65.2 W m(-2) and 42.1 W m(-2) with and without the presence of aerosol, respectively. C1 Chinese Acad Sci, Lab Middle Atmosphere & Global Environm Observat, Inst Atmospher Phys, Beijing 100021, Peoples R China. Univ Maryland, Dept Atomospher & Ocean Sci, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Chinese Meteorol Adm, Chinese Acad Meteorol Sci, Beijing, Peoples R China. RP Chen, HB (reprint author), Chinese Acad Sci, Lab Middle Atmosphere & Global Environm Observat, Inst Atmospher Phys, Beijing 100021, Peoples R China. EM xiaxiangao2000@yahoo.com RI Xia, Xiangao/G-5545-2011; ECK, THOMAS/D-7407-2012; Cribb, Maureen/K-1341-2013; Li, Zhanqing/F-4424-2010 OI Xia, Xiangao/0000-0002-4187-6311; Cribb, Maureen/0000-0002-9745-3676; Li, Zhanqing/0000-0001-6737-382X NR 51 TC 51 Z9 66 U1 0 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 NOV 21 PY 2007 VL 112 IS D22 AR D22S12 DI 10.1029/2007JD008859 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 235UG UT WOS:000251259200002 ER PT J AU Greve, TR Stern, D Ivison, RJ De Breuck, C Kovacs, A Bertoldi, F AF Greve, T. R. Stern, D. Ivison, R. J. De Breuck, C. Kovacs, A. Bertoldi, F. TI Wide-field mid-infrared and millimetre imaging of the high-redshift radio galaxy, 4C 41.17 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : formation; galaxies : individual : 4C 41.17; galaxies : starburst; cosmology : observations; early Universe ID OPTICALLY SELECTED QUASARS; DEGREE EXTRAGALACTIC SURVEY; LYMAN-BREAK GALAXIES; LY-ALPHA EMISSION; SUBMILLIMETER GALAXIES; STAR-FORMATION; PROTO-CLUSTER; NUMBER COUNTS; DEEP-FIELD; SKY SURVEY AB (z = 3.792) and luminous known radio galaxies - obtained with the Submillimeter High Angular Resolution Camera (SHARC-II) and the Max Planck Millimeter Bolometer Array (MAMBO). The radio galaxy is robustly detected at 350 and 1200 mu m, as are two nearby 850-mu m- selected galaxies; a third 850-mu m source is detected at 350 mu m and coincides with a similar to 2 sigma s feature in the 1200-mu m map. Farther away from the radio galaxy additional nine sources are detected at 1200 mu m, bringing the total number of detected (sub) millimetre-selected galaxies (SMGs) in this field to 14. Using radio images from the Very Large Array and Spitzer mid-infrared data, we find statistically robust radio and/or 24-mu m counterparts to eight out of the 14 SMGs in the field around 4C 41.17. Follow-up spectroscopy with Keck/Low-Resolution and Imaging Spectrograph (LRIS) has yielded redshifts for three out of the eight robustly identified SMGs, placing them in the redshift range 0.5 less than or similar to z less than or similar to 2.7 that is well below that of 4C 41.17. We infer photometric redshifts for a further four sources using their 1.6-mu m (rest-frame) stellar feature as probed by the IRAC bands; only one of them is likely to be at the same redshift as 4C 41.17. Thus at least four, and as many as seven, of the SMGs within the 4C 41.17 field are physically unrelated to the radio galaxy. With the redshift information at hand, we are able to constrain the observed overdensities of SMGs within radial bins stretching to R = 50 and 100 arcsec (similar to 0.4 and similar to 0.8 Mpc at z similar or equal to 3.8) from the radio galaxy to approximately five times and two times that of the field, dropping off to the background value at R = 150 arcsec. We thus confirm that 4C 41.17 resides in an overdense region of the Universe, but we have only been able to identify SMGs along the line of sight to the radio galaxy, typical of the blank-field SMG population. Finally, we report on the discovery of an extremely extended (similar to 110 kpc) Ly alpha blob at z = 2.672 associated with the brightest 1200-mu m source in the field. C1 CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Royal Observ, UK Astron Technol Ctr, Edinburgh EH9 3HJ, Midlothian, Scotland. Univ Edinburgh, Inst Astron, Edinburgh EH9 3HJ, Midlothian, Scotland. European So Observ, D-85748 Garching, Germany. Max Planck Inst Radioastron, D-53121 Bonn, Germany. Univ Bonn, Argelander Inst Astron, D-53121 Bonn, Germany. RP Greve, TR (reprint author), CALTECH, Pasadena, CA 91125 USA. EM tgreve@submm.caltech.edu RI Kovacs, Attila/C-1171-2010; Ivison, R./G-4450-2011 OI Kovacs, Attila/0000-0001-8991-9088; Ivison, R./0000-0001-5118-1313 NR 87 TC 28 Z9 28 U1 0 U2 1 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 NOV 21 PY 2007 VL 382 IS 1 BP 48 EP 66 DI 10.1111/j.1365-2966.2007.12292.x PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 229RN UT WOS:000250822000022 ER PT J AU Trujillo, I Conselice, CJ Bundy, K Cooper, MC Eisenhardt, P Ellis, RS AF Trujillo, Ignacio Conselice, C. J. Bundy, Kevin Cooper, M. C. Eisenhardt, P. Ellis, Richard S. TI Strong size evolution of the most massive galaxies since z similar to 2 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 DIGITAL SKY SURVEY; ELLIPTIC GALAXIES; STAR-FORMATION; DISK GALAXIES; DISSIPATIONLESS COLLAPSE; POPULATION SYNTHESIS; DYNAMICAL EVOLUTION; STELLAR POPULATIONS; VIOLENT RELAXATION; FUNDAMENTAL PLANE AB Using the combined capabilities of the large near-infrared Palomar/DEEP-2 survey, and the superb resolution of the Advanced Camera for Surveys HST camera, we explore the size evolution of 831 very massive galaxies (M-star >= 10(11)h(70)(-2)M(circle dot)) since z similar to 2. We split our sample according to their light concentration using the Sersic index n. At a given stellar mass, both low (n < 2.5) and high (n > 2.5) concentrated objects were much smaller in the past than their local massive counterparts. This evolution is particularly strong for the highly concentrated (spheroid like) objects. At z similar to 1.5, massive spheroid-like objects were a factor of 4 (+/- 0.4) smaller (i.e. almost two orders of magnitudes denser) than those we see today. These small sized, high-mass galaxies do not exist in the nearby Universe, suggesting that this population merged with other galaxies over several billion years to form the largest galaxies we see today. C1 Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England. Univ Toronto, Dept Astron & Astrophys, Toronto, ON M5S 3H4, Canada. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Caltech MC 105 24, Pasadena, CA 91125 USA. RP Trujillo, I (reprint author), Inst Astrofis Canarias, Via Lactea S-N, Tenerife 38200, Spain. EM trujillo@iac.es RI Conselice, Christopher/B-4348-2013 NR 79 TC 275 Z9 278 U1 0 U2 5 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 2007 VL 382 IS 1 BP 109 EP 120 DI 10.1111/j.1365-2966.2007.12388.x PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 229RN UT WOS:000250822000026 ER PT J AU Nandra, K O'Neill, PM George, IM Reeves, JN AF Nandra, K. O'Neill, P. M. George, I. M. Reeves, J. N. TI An XMM-Newton survey of broad iron lines in Seyfert galaxies SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Review DE galaxies; active; galaxies; nuclei; galaxies; Seyfert; X-rays; galaxies ID ACTIVE GALACTIC NUCLEI; X-RAY-SPECTRUM; K-ALPHA LINE; BLACK-HOLE MASS; FOURIER-RESOLVED SPECTROSCOPY; ACCRETION DISKS; EMISSION-LINE; ASCA OBSERVATIONS; IONIZED OUTFLOW; COLD MATTER AB We present an analysis of the X-ray spectra of a sample of 37 observations of 26 Seyfert galaxies observed by XMM-Newton in order to characterize their iron K alpha emission. All objects show evidence for iron line emission in the 6-7 keV band. A narrow 'core' at 6.4 keV is seen almost universally in the spectra, and we model this using a neutral Compton reflection component, assumed to be associated with distant, optically thick material such as the molecular torus. Once this, and absorption by a zone of ionized gas in the line of sight is accounted for, less than half of the sample observations show an acceptable fit. Approximately two-thirds of the sample shows evidence for further, broadened emission in the iron K band. When modelled with a Gaussian, the inferred energy is close to that expected for neutral iron, with a slight redshift, and an average velocity width of similar to 0.1c. The mean parameters are consistent with previous ASCA results and support the idea that the broad components can be associated with the accretion disc. Before proceeding to that conclusion, we test an alternative model comprising a blend of three to four narrow, unshifted emission lines (including the 6.4-keV core), together with one to two zones of highly ionized gas in the line of sight. Around one- third of the objects are not adequately fitted by this model, and in general better fits are obtained with a relativistic disc line model, which has fewer free parameters. None the less we find that absorption by ionized gas affects the spectrum above 2.5 keV in approximately half the sample. There is evidence for multiple ionized zones in at least three objects, but in all those cases a blurred reflector is required in addition to the complex absorption. We also identify a number of narrow emission and absorption features around the Fe complex, and the significance and interpretation of these lines is discussed. After accounting for these additional complexities, we determine the typical parameters for the broad reflection. The emission is found to come, on average, from a characteristic radius similar to 15 r(g) and the average disc inclination is similar to 40 degrees. The broad reflection is on average significantly weaker, by a factor of similar to 2, than that expected from a flat disc illuminated by a point source. Notwithstanding these average properties, the objects exhibit a significant and wide range of reflection parameters. We find that 30 per cent of the sample observations can be explained solely with narrow- line components, with no evidence for broadened emission at all. A further 25 per cent show evidence for significant broad emission, but at a characteristic radius relatively far from the black hole. The remaining similar to 45 per cent are best fitted with a relativistically blurred reflection model. In 12/ 37 observations the characteristic emission radius is constrained to be < 50 r(g), where the gravitational redshift is measurable. For at least this subsample, our observations verify the potential for X-ray spectroscopy to diagnose the strong-gravity regime of supermassive black holes. C1 Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2AZ, England. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP Nandra, K (reprint author), Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, Prince Consort Rd, London SW7 2AZ, England. EM k.nandra@imperial.ac.uk NR 167 TC 290 Z9 290 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 2007 VL 382 IS 1 BP 194 EP 228 DI 10.1111/j.1365-2966.2007.12331.x PG 35 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 229RN UT WOS:000250822000032 ER PT J AU Prinja, RK Hodges, SE Massa, DL Fullerton, AW Burnley, AW AF Prinja, R. K. Hodges, S. E. Massa, D. L. Fullerton, A. W. Burnley, A. W. TI Structure and clumping in the fast wind of NGC 6543 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars; evolution; stars; individual; NGC 6543; stars; winds; outflows ID O-TYPE STARS; IUE MEGA CAMPAIGN; PLANETARY-NEBULAE; STELLAR WIND; TIME-SERIES; MASS-LOSS; B-SUPERGIANTS; VARIABILITY; SIMULATIONS; EVOLUTION AB Far-ultraviolet spectroscopy from the FUSE satellite is analysed to uniquely probe spatial structure and clumping in the fast wind of the central star of the H- rich planetary nebula NGC 6543 (HD 164963). Time-series data of the unsaturated Pv lambda lambda 1118, 1128 resonance line P Cygni profiles provide a very sensitive diagnostic of variable wind conditions in the outflow. We report on the discovery of episodic and recurrent optical depth enhancements in the Pv absorption troughs, with some evidence for a similar to 0.17-d modulation time-scale. Empirical line-synthesis modelling is used to derive physical properties, including the optical depth evolution of individual 'events'. The characteristics of these features are essentially identical to the ` discrete absorption components' (DACs) commonly seen in the ultraviolet lines of massive OB stars. We have also employed the unified model atmosphere code CMFGEN to explore spectroscopic signatures of clumping, and report, in particular, on the clear sensitivity of the Pv lines to the clump volume filling factor. The results presented here have implications for the downward revision of mass-loss rates in planetary nebula central stars. We conclude that the temporal structures seen in the Pv lines of NGC 6543 likely have a physical origin that is similar to that operating in massive, luminous stars, and may be related to near-surface perturbations caused by stellar pulsation and/or magnetic fields. C1 UCL, Dept Phys & Astron, London WC1E 6BT, England. NASA, Goddard Space Flight Ctr, SGT Inc, Greenbelt, MD 20771 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Prinja, RK (reprint author), UCL, Dept Phys & Astron, Gower St, London WC1E 6BT, England. EM rkp@star.ucl.ac.uk; seh@star.ucl.ac.uk; massa@taotaomona.gsfc.nasa.gov; fullerton@stsci.edu; awxb@star.ucl.ac.uk NR 49 TC 13 Z9 13 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD NOV 21 PY 2007 VL 382 IS 1 BP 299 EP 307 DI 10.1111/j.1365-2966.2007.12360.x PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 229RN UT WOS:000250822000040 ER PT J AU Alexandrov, MD Kiedron, P Michalsky, JJ Hodges, G Flynn, CJ Lacis, AA AF Alexandrov, Mikhail D. Kiedron, Peter Michalsky, Joseph J. Hodges, Gary Flynn, Connor J. Lacis, Andrew A. TI Optical depth measurements by shadow-band radiometers and their uncertainties SO APPLIED OPTICS LA English DT Article ID ATMOSPHERIC RADIATION MEASUREMENT; NETWORK; INSTRUMENT; RETRIEVAL; PROGRAM AB Shadow-band radiometers in general, and especially the Multi-Filter Rotating Shadow-band Radiometer (MFRSR), are widely used for atmospheric optical depth measurements. The major programs running MFRSR networks in the United States include the Department of Energy Atmospheric Radiation Measurement (ARM) Program, U.S. Department of Agriculture UV-B Monitoring and Research Program, National Oceanic and Atmospheric Administration Surface Radiation (SURFRAD) Network, and NASA Solar Irradiance Research Network (SIRN). We discuss a number of technical issues specific to shadow-band radiometers and their impact on the optical depth measurements. These problems include instrument tilt and misalignment, as well as some data processing artifacts. Techniques for data evaluation and automatic detection of some of these problems are described. (C) 2007 Optical Society of America. C1 [Alexandrov, Mikhail D.] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA. [Alexandrov, Mikhail D.; Lacis, Andrew A.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Kiedron, Peter; Hodges, Gary] NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA. [Flynn, Connor J.] Pacif Northwest Natl Lab, Richland, WA 99352 USA. RP Alexandrov, MD (reprint author), Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA. EM malexandrov@giss.nasa.gov RI Lacis, Andrew/D-4658-2012 NR 21 TC 15 Z9 15 U1 0 U2 6 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 NOV 20 PY 2007 VL 46 IS 33 BP 8027 EP 8038 DI 10.1364/AO.46.008027 PG 12 WC Optics SC Optics GA 243XK UT WOS:000251830400009 PM 18026540 ER PT J AU Wysocki, G Bakhirkin, Y So, S Tittel, FK Hill, CJ Yang, RQ Fraser, MP AF Wysocki, Gerard Bakhirkin, Yury So, Stephen Tittel, Frank K. Hill, Cory J. Yang, Rui Q. Fraser, Matthew P. TI Dual interband cascade laser based trace-gas sensor for environmental monitoring SO APPLIED OPTICS LA English DT Article ID SPECTROSCOPY; SPECTROMETER; SYSTEMS AB The development of an interband cascade laser (ICL) based spectroscopic trace-gas sensor for the simultaneous detection of two atmospheric trace gases is reported. The sensor performance was evaluated using two ICLs capable of targeting formaldehyde (H2CO) and ethane (C2H6). Minimum detection limits of 3.5 ppbV for H2CO and 150 pptV for C2H6 was demonstrated with a 1 s integration time. The sensor was deployed for field measurements of H2CO, and laboratory quantification of both formaldehyde and ethane are reported. A cross comparison of the atmospheric concentration data for H2CO with data collected by a collocated commercial H2CO sensor employing Hantzsch reaction based fluorometric detection was performed. These results show excellent agreement between these two different approaches for trace-gas quantification. In addition, laboratory experiments for dual gas quantification show accurate, fast response with no crosstalk between the two gas channels. (c) 2007 Optical Society of America. C1 [Wysocki, Gerard; Bakhirkin, Yury; So, Stephen; Tittel, Frank K.] Rice Univ, Dept Elect & Comp Engn, Houston, TX 77251 USA. [Hill, Cory J.; Yang, Rui Q.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Fraser, Matthew P.] Rice Univ, Dept Civil & Environm Engn, Houston, TX 77251 USA. RP Wysocki, G (reprint author), Rice Univ, Dept Elect & Comp Engn, 6100 Main Str, Houston, TX 77251 USA. EM gerardw@rice.edu RI fraser, matthew/G-6355-2012 OI fraser, matthew/0000-0002-6239-9104 NR 21 TC 37 Z9 40 U1 2 U2 13 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 NOV 20 PY 2007 VL 46 IS 33 BP 8202 EP 8210 DI 10.1364/AO.46.008202 PG 9 WC Optics SC Optics GA 243XK UT WOS:000251830400029 PM 18026560 ER PT J AU Sambruna, RM Donato, D Tavecchio, F Maraschi, L Cheung, CC Urry, CM AF Sambruna, Rita M. Donato, Davide Tavecchio, F. Maraschi, L. Cheung, C. C. Urry, C. Megan TI Deep Chandra and multicolor HST observations of the jets of 3C 371 and PKS 2201+044 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : jets; X-rays : galaxies ID BL LACERTAE OBJECTS; ACTIVE GALACTIC NUCLEI; HUBBLE-SPACE-TELESCOPE; X-RAY JET; POWER RADIO GALAXIES; LARGE-SCALE JETS; PARENT POPULATION; VLBI OBSERVATIONS; PKS 0521-365; QUASAR JETS AB This paper presents multiwavelength imaging and broadband spectroscopy of the relativistic jets in the two nearby radio galaxies 3C 371 and PKS 2201+044, acquired with Chandra, HST, VLA, and MERLIN. Radio polarization is also presented for 3C 371. The two sources stand out as "intermediate'' between FR I and FR II type galaxies; their cores are classified as BL Lacertae objects, although broad and narrow optical emission lines were detected at times. The multiwavelength images show jet morphologies with the X-ray emission peaking closer to the nucleus than the longer wavelengths. The jets are resolved at all wavelengths in a direction perpendicular to the jet axis. The jets SEDs are consistent with a single spectral component from radio to X-rays, interpreted as synchrotron emission. The SEDs show a progressive softening from the inner to the outer regions of the jet, indicating that the electron break energy moves to lower energies with distance from the core. Overall, the X-ray and multiwavelength properties of the jets of 3C 371 and PKS 2201+044 appear intermediate between those of FR I and FR II galaxies. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Osserv Astron Brera, I-20121 Milan, Italy. Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Yale Univ, New Haven, CT 06520 USA. RP Sambruna, RM (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM rita.m.sambruna@nasa.gov RI Urry, Claudia/G-7381-2011 OI Urry, Claudia/0000-0002-0745-9792 NR 58 TC 23 Z9 23 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 2007 VL 670 IS 1 BP 74 EP 91 DI 10.1086/521972 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231QZ UT WOS:000250965400005 ER PT J AU Marshall, JA Herter, TL Armus, L Charmandaris, V Spoon, HWW Bernard-Salas, J Houck, JR AF Marshall, J. A. Herter, T. L. Armus, L. Charmandaris, V. Spoon, H. W. W. Bernard-Salas, J. Houck, J. R. TI Decomposing dusty galaxies. I. Multicomponent spectral energy distribution fitting SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : Seyfert; galaxies : starburst; infrared : galaxies; methods : numerical ID ULTRALUMINOUS INFRARED GALAXIES; ACTIVE GALACTIC NUCLEI; SPITZER-SPACE-TELESCOPE; STAR-FORMING GALAXIES; POLYCYCLIC AROMATIC-HYDROCARBON; SMALL-MAGELLANIC-CLOUD; STARBURST GALAXIES; INTERSTELLAR DUST; SPECTROGRAPH IRS; MIDINFRARED SPECTROSCOPY AB We present a new multicomponent SED decomposition method and use it to analyze the UV to millimeter wavelength SEDs of a sample of dusty infrared-luminous galaxies. Each SED is decomposed into emission from populations of stars, an AGN accretion disk, PAHs, atomic and molecular lines, and distributions of graphite and silicate grains. Decompositions of the SEDs of template starburst galaxies and AGNs provide baseline properties to aid in quantifying the strength of star formation and accretion in the composite systems NGC 6240 and Mrk 1014. We find that obscured radiation from stars is capable of powering the total dust emission from NGC 6240. The presence of a small quantity of 1260 K dust in this source suggests a similar to 2% AGN contribution, although we cannot rule out a larger contribution from a deeply embedded AGN visible only in X-rays. The decomposition of Mrk 1014 is consistent with similar to 65% of its power emerging from an AGN and similar to 35% from star formation. We suggest that many of the variations in our template starburst SEDs may be explained in terms of the different mean optical depths through the clouds of dust surrounding the young stars within each galaxy. Prompted by the divergent far-IR properties of our template AGNs, we suggest that variations in the relative orientation of their AGN accretion disks with respect to the disks of the galaxies hosting them may result in different amounts of AGN-heated cold dust emission emerging from their host galaxies. We estimate that 30%-50% of the far-IR and PAH emission from Mrk 1014 may originate from such AGN-heated material in its host galaxy disk. C1 Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. CALTECH, Pasadena, CA 91125 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. Spitzer Sci Ctr, CALTECH, Pasadena, CA 91125 USA. Univ Crete, Dept Phys, GR-71003 Iraklion, Greece. IESL, FORTH, GR-71110 Iraklion, Greece. Observ Paris, Chercheur Assoc, F-75014 Paris, France. RP Marshall, JA (reprint author), Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. EM jason.marshall@caltech.edu RI Charmandaris, Vassilis/A-7196-2008 OI Charmandaris, Vassilis/0000-0002-2688-1956 NR 100 TC 38 Z9 38 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 2007 VL 670 IS 1 BP 129 EP 155 DI 10.1086/521588 PN 1 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231QZ UT WOS:000250965400009 ER PT J AU Groppi, CE Hunter, TR Blundell, R Sandell, G AF Groppi, Christopher E. Hunter, Todd R. Blundell, Raymond Sandell, Goeran TI High spatial resolution observations of two young protostars in the R corona australis region SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : clouds; ISM : individual (R Corona Australis); ISM : jets and outflows; ISM : kinematics and dynamics; ISM : molecules; radio lines : ISM; stars : formation ID HERBIG-HARO OBJECTS; STELLAR OBJECTS; X-RAY; MOLECULAR CLOUD; STAR-FORMATION; RADIO-EMISSION; CLUSTER; CORE; TELESCOPE; OUTFLOWS AB We present multiwavelength, high spatial resolution imaging of the IRS 7 region in the R Corona Australis molecular cloud. Our observations include 1.1 mm continuum and HCO+ J = 3 -> 2 images from the Submillimeter Array (SMA), (CO)-C-12 J = 3 -> 2 outflow maps from the DesertStar heterodyne array receiver on the Heinrich Hertz Telescope (HHT), 450 and 850 mu m continuum images from SCUBA, and archival Spitzer IRAC and MIPS 24 mu m images. The accurate astrometry of the IRAC images allow us to identify IRS 7 with the centimeter source VLA 10W (IRS 7A) and the X-ray source X-W. The SMA 1.1 mm image reveals two compact continuum sources that are also distinguishable at 450 mu m. SMA1 coincides with X-ray source CXOUJ190156.4-365728 and VLA centimeter source 10E (IRS 7B) and is seen in the IRAC and MIPS images. SMA 2 has no infrared counterpart but coincides with centimeter source VLA 9. Spectral energy distributions constructed from SMA, SCUBA, and Spitzer data yield bolometric temperatures of 83 K for SMA 1 and <= 70 K for SMA 2. These temperatures along with the submillimeter to total luminosity ratios indicate that SMA 2 is a Class 0 protostar, while SMA1 is a Class 0/Class I transitional object (L = 17 +/- 6L circle dot). The (12)COJ = 3 -> 2 outflow map shows one major and possibly several smaller outflows centered on the IRS 7 region, with masses and energetics consistent with previous work. We identify the Class 0 source SMA 2/VLA 9 as the main driver of this outflow. The complex and clumpy spatial and velocity distribution of the HCO+ J = 3 -> 2 emission is not consistent with either bulk rotation, or any known molecular outflow activity. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. NASA, Ames Res Ctr, SOFIA USRA, Moffett Field, CA 94035 USA. RP Groppi, CE (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. EM cgroppi@as.arizona.edu RI Blundell, Richard/C-1552-2008; Groppi, Christopher/L-5284-2013 OI Blundell, Richard/0000-0003-1588-2299; Groppi, Christopher/0000-0002-2021-1628 NR 46 TC 21 Z9 21 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 2007 VL 670 IS 1 BP 489 EP 498 DI 10.1086/521875 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231QZ UT WOS:000250965400036 ER PT J AU Winkler, PF Petre, R AF Winkler, P. Frank Petre, Robert TI Direct measurement of neutron star recoil in the oxygen-rich supernova remnant Puppis A SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrometry; ISM : individual (Puppis A); stars : neutron; supernova remnants; supernovae : general; X-rays : individual (RX J0822-4300) ID LARGE MAGELLANIC CLOUD; CASSIOPEIA-A; PROPER-MOTION; RX J0822-4300; PULSAR; EXPLOSIONS; COLLAPSE; DISCOVERY; CHANDRA; NEBULA AB A sequence of three Chandra X-Ray Observatory High Resolution Camera images taken over a span of five years reveals arcsecond-scale displacement of RX J0822-4300, the stellar remnant ( presumably a neutron star) near the center of the Puppis A supernova remnant. We measure its proper motion to be 0.165" +/- 0.025" yr(-1) toward the west-southwest. At a distance of 2 kpc, this corresponds to a transverse space velocity of similar to 1600 km s(-1). The space velocity is consistent with the explosion center inferred from proper motions of the oxygen-rich optical filaments and confirms the idea that Puppis A resulted from an asymmetric explosion accompanied by a kick that imparted roughly 3 x 10(49) ergs of kinetic energy (some 3% of the kinetic energy for a typical supernova) to the stellar remnant. We discuss constraints on core-collapse supernova models that have been proposed to explain neutron star kick velocities. C1 Middlebury Coll, Dept Phys, Middlebury, VT 05753 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Winkler, PF (reprint author), Middlebury Coll, Dept Phys, Middlebury, VT 05753 USA. EM winkler@middlebury.edu; robert.petre-1@nasa.gov NR 49 TC 33 Z9 33 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 NOV 20 PY 2007 VL 670 IS 1 BP 635 EP 642 DI 10.1086/522101 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231QZ UT WOS:000250965400048 ER PT J AU Zenitani, S Hoshino, M AF Zenitani, S. Hoshino, M. TI Particle acceleration and magnetic dissipation in relativistic current sheet of pair plasmas SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; magnetic fields; plasmas; pulsars : individual (Crab Pulsar) relativity; stars : winds; outflows ID DRIFT KINK INSTABILITY; ACTIVE GALACTIC NUCLEI; TEARING INSTABILITY; PULSAR WIND; RECONNECTION; FIELD; SIMULATIONS; MECHANISM; MAGNETOTAIL; MODEL AB We study linear and nonlinear development of relativistic and ultrarelativistic current sheets of pair (e(+/-)) plasmas with antiparallel magnetic fields. Two types of two-dimensional problems are investigated by particle-in-cell simulations. First, we present the development of relativistic magnetic reconnection, whose outflow speed is on the order of the light speed c. It is demonstrated that particles are strongly accelerated in and around the reconnection region and that most of the magnetic energy is converted into a "nonthermal'' part of plasma kinetic energy. Second, we present another two-dimensional problem of a current sheet in a cross field plane. In this case, the relativistic drift kink instability (RDKI) occurs. Particle acceleration also takes place, but the RDKI quickly dissipates the magnetic energy into plasma heat. We discuss the mechanism of particle acceleration and the theory of the RDKI in detail. It is important that properties of these two processes are similar in the relativistic regime of T greater than or similar to mc(2), as long as we consider the kinetics. Comparison of the two processes indicates that magnetic dissipation by the RDKI is a more favorable process in the relativistic current sheet. Therefore, the striped pulsar wind scenario should be reconsidered by the RDKI. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. RP Zenitani, S (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM zenitani@lssp-mail.gsfc.nasa.gov RI Zenitani, Seiji/D-7988-2013 OI Zenitani, Seiji/0000-0002-0945-1815 NR 53 TC 92 Z9 92 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2007 VL 670 IS 1 BP 702 EP 726 DI 10.1086/522226 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231QZ UT WOS:000250965400054 ER PT J AU Sui, LH Holman, GD Dennis, BR AF Sui, Linhui Holman, Gordon D. Dennis, Brian R. TI Nonthermal X-ray spectral flattening toward low energies in early impulsive flares SO ASTROPHYSICAL JOURNAL LA English DT Article DE sun : flares; sun : X-rays; gamma rays ID SOLAR-FLARES; PHOTOSPHERIC ALBEDO; ELECTRON-SPECTRA; RHESSI; CUTOFF; BREMSSTRAHLUNG; POLARIZATION; SPECTROSCOPY; DIRECTIVITY; IONIZATION AB The determination of the low-energy cutoff to nonthermal electron distributions is critical to the calculation of the nonthermal energy in solar flares. The most direct evidence for low-energy cutoffs is flattening of the power-law, nonthermal X-ray spectra at low energies. However, because of the plasma preheating often seen in flares, the thermal emissions at low energies may hide such spectral flattening of the nonthermal component. We select a category of flares, which we call "early impulsive flares,'' in which the >25 keV hard X-ray (HXR) flux increase is delayed by less than 30 s after the flux increase at lower energies. Thus, the plasma preheating in these flares is minimal, so the nonthermal spectrum can be determined to lower energies than in flares with significant preheating. Out of a sample of 33 early impulsive flares observed by the Ramaty High Energy Solar Spectroscopy Imager (RHESSI), nine showed spectral flattening toward low energies. In these events, the break energy of the double power-law fit to the HXR spectra lies in the range 10-50 keV, significantly lower than the value we have seen for other flares that do not show such early impulsive emissions. In particular, it correlates with the HXR flux. After correcting the spatially integrated spectra for albedo from isotropically emitted X-rays and using RHESSI imaging spectroscopy to exclude the extended albedo halo, we find that albedo associated with isotropic or nearly isotropic electrons can only account for the spectral flattening in three flares near Sun center. The spectral flattening in the remaining six flares is found to be consistent with the existence of a low-energy cutoff in the electron spectrum, falling in the range 15-50 keV, which also correlates with the HXR flux. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Solar Phys Lab, Greenbelt, MD 20771 USA. RP Sui, LH (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RI Dennis, Brian/C-9511-2012; Holman, Gordon/C-9548-2012 NR 39 TC 35 Z9 36 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 NOV 20 PY 2007 VL 670 IS 1 BP 862 EP 871 DI 10.1086/522198 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231QZ UT WOS:000250965400068 ER PT J AU Kong, AKH Miller, JM Mendez, M Cottam, J Lewin, WHG Paerels, F Kuulkers, E Wijnands, R Van der Klis, M AF Kong, Albert K. H. Miller, Jon M. Mendez, Mariano Cottam, Jean Lewin, Walter H. G. Paerels, Frederik Kuulkers, Erik Wijnands, Rudy Van der Klis, Michiel TI Nondetection of gravitationally redshifted absorption lines in the X-ray burst spectra of gs 1826-24 SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; stars : individual (GS 1826-24); stars : neutron; X-rays : binaries; X-rays : bursts ID ROTATING NEUTRON-STARS; THERMONUCLEAR FLASHES; ATOMIC LINES; GS 1826-24; EXO-0748-676; DISCOVERY; ACCRETION; FEATURES AB During a 200 ks observation with the XMM-Newton Reflection Grating Spectrometer, we detected 16 type I X-ray bursts from GS 1826-24. We combined the burst spectra in an attempt to measure the gravitational redshifts from the surface of the neutron star. We divided the composite GS 1826-24 burst spectrum into three groups based on the blackbody temperature during the bursts. The spectra do not show any obvious discrete absorption lines. We compare our observations with those of EXO 0748-676. C1 MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. Natl Tsing Hua Univ, Inst Astron, Dept Phys, Hsinchu, Taiwan. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. SRON, Netherlands Inst Space Res, NL-3584 CA Utrecht, CA, Netherlands. NASA, Goddard Space Flight Ctr, Explorat Univ Div, Greenbelt, MD 20771 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. ESA, ESAC, ISOC, Madrid 28080, Spain. Univ Amsterdam, Astron Inst Anton Pannekoek, Amsterdam, Netherlands. RP Kong, AKH (reprint author), MIT, Kavli Inst Astrophys & Space Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM akong@phys.nthu.edu.tw RI Mendez, Mariano/C-8011-2012 OI Mendez, Mariano/0000-0003-2187-2708 NR 23 TC 12 Z9 12 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 2007 VL 670 IS 1 BP L17 EP L20 DI 10.1086/524137 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 231RC UT WOS:000250965700005 ER PT J AU D'Antoni, H Rothschild, L Schultz, C Burgess, S Skiles, JW AF D'Antoni, Hector Rothschild, Lynn Schultz, Cynthia Burgess, Seth Skiles, J. W. TI Extreme environments in the forests of Ushuaia, Argentina SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NOTHOFAGUS-PUMILIO FORESTS; TIERRA-DEL-FUEGO; ALTITUDINAL GRADIENT; ACTION SPECTRA; NEW-ZEALAND; GROWTH; RANGE; ANDES AB A survey over two mountain slopes ( Glaciar Martial and Cerro Guanaco) in the vicinity of Ushuaia ( Tierra del Fuego, Argentina) showed normal results for the region in terms of chlorophyll concentration in the leaves of the dominant tree species Nothofagus antarctica, N. pumilio and N. betuloides, and soil variables such as temperature, moisture, pH, and concentration of nitrogen, sodium and potassium. Solar radiation, on the other hand, showed high values of ultraviolet over the 200-400 nm range, suggesting that the environment is extreme in terms of incoming solar radiation. The forest canopy absorbs and/ or reflects a significant amount of that radiation. In separate analyses we showed that these tree species contain UV-absorbing pigments ( cyanidin, delphidin, and flavonol glycosides). We submit that the rippled and glossy surface of leaves serves as a reflection/ backscattering mechanism that protects their inner structure and function. The presence of krummholz (= twisted, dwarf trees) in the upper end of the forest shows the effects of an extreme environment. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. San Jose State Univ, Dept Geol, San Jose, CA 95192 USA. RP D'Antoni, H (reprint author), NASA, Ames Res Ctr, MS 239-20, Moffett Field, CA 94035 USA. EM hector.l.dantoni@nasa.gov NR 31 TC 3 Z9 3 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 20 PY 2007 VL 34 IS 22 AR L22704 DI 10.1029/2007GL031096 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 235TK UT WOS:000251257000002 ER PT J AU Sobel, AH Bellon, G Bacmeister, J AF Sobel, A. H. Bellon, G. Bacmeister, J. TI Multiple equilibria in a single-column model of the tropical atmosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CIRCULATION MODEL; CUMULUS CONVECTION; RESOLVING MODEL; PRECIPITATION; SIMULATION; SHALLOW AB A single-column model run under the weak temperature gradient approximation, a parameterization of large-scale dynamics appropriate for the tropical atmosphere, is shown to have multiple stable equilibria. Under conditions permitting persistent deep convection, the model has a statistically steady state in which such convection occurs, as well as an extremely dry state in which convection does not occur. Which state is reached depends on the initial moisture profile. C1 Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. Columbia Univ, Dept Earth & Environm Sci, New York, NY USA. RP Sobel, AH (reprint author), Columbia Univ, Dept Appl Phys & Appl Math, 500 W 120th St,Room 202, New York, NY 10027 USA. EM ahs129@columbia.edu RI Sobel, Adam/K-4014-2015; OI Sobel, Adam/0000-0003-3602-0567; Bellon, Gilles/0000-0003-3981-1225 NR 19 TC 39 Z9 39 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 20 PY 2007 VL 34 IS 22 AR L22804 DI 10.1029/2007GL031320 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 235TK UT WOS:000251257000005 ER PT J AU Barnes, JW Radebaugh, J Brown, RH Wall, S Soderblom, L Lunine, J Burr, D Sotin, C Le Mouelic, S Rodriguez, S Buratti, BJ Clark, R Baines, KH Jaumann, R Nicholson, PD Kirk, RL Lopes, R Lorenz, RD Mitchell, K Wood, CA AF Barnes, Jason W. Radebaugh, Jani Brown, Robert H. Wall, Steve Soderblom, Laurence Lunine, Jonathan Burr, Devon Sotin, Christophe Le Mouelic, Stephane Rodriguez, Sebastien Buratti, Bonnie J. Clark, Roger Baines, Kevin H. Jaumann, Ralf Nicholson, Phillip D. Kirk, Randolph L. Lopes, Rosaly Lorenz, Ralph D. Mitchell, Karl Wood, Charles A. TI Near-infrared spectral mapping of Titan's mountains and channels SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID RADAR MAPPER; SURFACE; VIMS; ACETYLENE; ALBEDO; WINDS AB We investigate the spectral reflectance properties of channels and mountain ranges on Titan using data from Cassini's Visual and Infrared Mapping Spectrometer (VIMS) obtained during the T9 encounter (26 December 2005). We identify the location of channels and mountains using synthetic aperture radar maps obtained from Cassini's RADAR instrument during the T13 ( 30 April 2006) flyby. Channels are evident even in VIMS imaging with spatial resolution coarser than the channel size. The channels share spectral characteristics with Titan's dark blue terrain (e. g., the Huygens landing site) that is consistent with an enhancement in water ice content relative to the rest of Titan. We use this fact to measure widths of similar to 1 km for the largest channels. Comparison of the data sets shows that in our study area within the equatorial bright spectral unit east of Xanadu, mountains are darker and bluer than surrounding smooth terrain. These results are consistent with the equatorial bright terrain possessing a veneer of material that is thinner in the regions where there are mountains and streambeds that have likely undergone more recent and extensive erosion. We suggest a model for the geographic relationship of the dark blue, dark brown, and equatorial bright spectral units based on our findings. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. SETI Inst, Carl Sagan Ctr, Mountain View, CA 94043 USA. US Geol Survey, Denver, CO 80225 USA. DLR, Inst Planetary Res, D-12489 Berlin, Germany. US Geol Survey, Flagstaff, AZ 86001 USA. Univ Nantes, CNRS, UMR, Lab Planetol & Geodynam, Nantes, France. Johns Hopkins Univ, Appl Phys Lab, Dept Space, Laurel, MD 20723 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Brigham Young Univ, Dept Geol Sci, Provo, UT 84502 USA. Ctr Orme Merisiers, DAPNIA Sap, Ctr Etud Saclay, Lab AIM, F-91191 Gif Sur Yvette, France. Planetary Sci Inst, Tucson, AZ 85719 USA. RP Barnes, JW (reprint author), Univ Arizona, Lunar & Planetary Lab, 1629 E Univ Blvd, Tucson, AZ 85721 USA. EM jbarnes@lpl.arizona.edu RI Barnes, Jason/B-1284-2009; Lorenz, Ralph/B-8759-2016; Lopes, Rosaly/D-1608-2016; Rodriguez, Sebastien/H-5902-2016 OI Barnes, Jason/0000-0002-7755-3530; Lorenz, Ralph/0000-0001-8528-4644; Lopes, Rosaly/0000-0002-7928-3167; Rodriguez, Sebastien/0000-0003-1219-0641 NR 42 TC 56 Z9 56 U1 0 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 NOV 20 PY 2007 VL 112 IS E11 AR E11006 DI 10.1029/2007JE002932 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 235VQ UT WOS:000251262800002 ER PT J AU Hayward, RK Mullins, KF Fenton, LK Hare, TM Titus, TN Bourke, MC Colaprete, A Christensen, PR AF Hayward, Rosalyn K. Mullins, Kevin F. Fenton, Lori K. Hare, Trent M. Titus, Timothy N. Bourke, Mary C. Colaprete, Anthony Christensen, Philip R. TI Mars global digital dune database and initial science results SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GENERAL-CIRCULATION MODEL; AEOLIAN PROCESSES; MARTIAN SURFACE; PROCTOR CRATER; ORBITER CAMERA; SAND; FEATURES; SIMULATIONS; SEDIMENT; MORPHOLOGY AB A new Mars Global Digital Dune Database (MGD(3)) constructed using Thermal Emission Imaging System (THEMIS) infrared (IR) images provides a comprehensive and quantitative view of the geographic distribution of moderate- to large-size dune fields ( area > 1 km 2) that will help researchers to understand global climatic and sedimentary processes that have shaped the surface of Mars. MGD(3) extends from 65 degrees N to 65 degrees S latitude and includes similar to 550 dune fields, covering similar to 70,000 km(2), with an estimated total volume of similar to 3,600 km(3). This area, when combined with polar dune estimates, suggests moderate- to large-size dune field coverage on Mars may total similar to 800,000 km(2), similar to 6 times less than the total areal estimate of similar to 5,000,000 km(2) for terrestrial dunes. Where availability and quality of THEMIS visible (VIS) or Mars Orbiter Camera narrow-angle (MOC NA) images allow, we classify dunes and include dune slipface measurements, which are derived from gross dune morphology and represent the prevailing wind direction at the last time of significant dune modification. For dunes located within craters, the azimuth from crater centroid to dune field centroid (referred to as dune centroid azimuth) is calculated and can provide an accurate method for tracking dune migration within smooth-floored craters. These indicators of wind direction are compared to output from a general circulation model (GCM). Dune centroid azimuth values generally correlate to regional wind patterns. Slipface orientations are less well correlated, suggesting that local topographic effects may play a larger role in dune orientation than regional winds. C1 US Geol Survey, Dept Astrogeol, Flagstaff, AZ 86001 USA. Planetary Sci Inst, Tucson, AZ 85719 USA. Arizona State Univ, Dept Geol Sci, Mars Space Flight Facil, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. NASA, Ames Res Ctr, Carl Sagan Ctr, Moffett Field, CA 94035 USA. Coconino Community Coll, Dept Sci, Flagstaff, AZ 86001 USA. RP Hayward, RK (reprint author), US Geol Survey, Dept Astrogeol, 2255 N Gemini Dr, Flagstaff, AZ 86001 USA. RI Bourke, Mary/I-4387-2012; OI Bourke, Mary/0000-0002-0424-0322; Hare, Trent/0000-0001-8842-389X NR 52 TC 57 Z9 59 U1 1 U2 16 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 20 PY 2007 VL 112 IS E11 AR E11007 DI 10.1029/2007JE002943 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 235VQ UT WOS:000251262800003 ER PT J AU Lew, JS Horta, LG AF Lew, Jiann-Shiun Horta, Lucas G. TI Uncertainty quantification using interval modeling with performance sensitivity SO JOURNAL OF SOUND AND VIBRATION LA English DT Article AB In this paper an interval modeling approach for uncertainty quantification of a structure with significant parameter variation is presented. Model uncertainty can be categorized as dominant uncertainty due to structural variation, such as joint uncertainty and temperature change, and minor uncertainty associated with other factors. In this paper, a singular value decomposition (SVD) technique is used to decompose parameter variations into principal components that are weighted based on the sensitivity of the performance metric to parameter variations. From this process, parameter bounds in the form of an interval model are generated and each interval corresponds to one identified bounded uncertainty parameter with its associated principal direction. The proposed approach can be used to differentiate between dominant and minor uncertainties. A beam structure with an attached subsystem proposed by Sandia National Laboratories is used to demonstrate this approach. (c) 2007 Elsevier Ltd. All rights reserved. C1 Tennessee State Univ, Ctr Excellence Informat Syst, Nashville, TN 37209 USA. NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. RP Lew, JS (reprint author), Tennessee State Univ, Ctr Excellence Informat Syst, Nashville, TN 37209 USA. EM lew@coe.tsuniv.edu NR 7 TC 8 Z9 8 U1 0 U2 2 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD NOV 20 PY 2007 VL 308 IS 1-2 BP 330 EP 336 DI 10.1016/j.jsv.2007.06.074 PG 7 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 220DR UT WOS:000250137600019 ER PT J AU Roland, A AF Roland, Alex TI von Braun - Dreamer of space, engineer of war SO NEW YORK TIMES BOOK REVIEW LA English DT Book Review C1 Duke Univ, Durham, NC 27706 USA. NASA, Washington, DC 20546 USA. RP Roland, A (reprint author), Duke Univ, Durham, NC 27706 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU NEW YORK TIMES PI NEW YORK PA 229 W 43RD ST, NEW YORK, NY 10036-3959 USA SN 0028-7806 J9 NY TIMES BK REV JI N. Y. Times Book Rev. PD NOV 18 PY 2007 BP 17 EP 17 PG 1 WC Humanities, Multidisciplinary SC Arts & Humanities - Other Topics GA 233BZ UT WOS:000251066700017 ER PT J AU Chen, JL Wilson, CR Tapley, BD Blankenship, DD Ivins, ER AF Chen, J. L. Wilson, C. R. Tapley, B. D. Blankenship, D. D. Ivins, E. R. TI Patagonia icefield melting observed by gravity recovery and climate experiment (GRACE) SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TIME-VARIABLE GRAVITY; SOUTH-AMERICA; ANTARCTICA; GLACIER AB Using recently released reprocessed gravity solutions from the Gravity Recovery and Climate Experiment (GRACE), we estimate the ice loss rate for the Patagonia Icefield (PIF) of South America, for the period April 2002 through December 2006. After postglacial rebound and hydrological effects are corrected, the estimated rate is -27.9 +/- 11 km(3)/year, equivalent to an average loss of similar to-1.6 m/year ice thickness change if evenly distributed over the entire PIF area. The estimated contribution to global sea level rise is 0.078 +/- 0.031 mm/year. This is an independent confirmation of relatively large melting rate estimates from earlier studies employing topographic and cartographic data. C1 Univ Texas Austin, Ctr Space Res, Austin, TX 78712 USA. Univ Texas Austin, Dept Geol Sci, Austin, TX USA. Univ Texas Austin, Inst Geophys, Austin, TX USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Chen, JL (reprint author), Univ Texas Austin, Ctr Space Res, Austin, TX 78712 USA. EM chen@csr.utexas.edu NR 23 TC 58 Z9 60 U1 1 U2 10 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 17 PY 2007 VL 34 IS 22 AR L22501 DI 10.1029/2007GL031871 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 232ZJ UT WOS:000251059900006 ER PT J AU Duncan, BN Logan, JA Bey, I Megretskaia, IA Yantosca, RM Novelli, PC Jones, NB Rinsland, CP AF Duncan, B. N. Logan, J. A. Bey, I. Megretskaia, I. A. Yantosca, R. M. Novelli, P. C. Jones, N. B. Rinsland, C. P. TI Global budget of CO, 1988-1997: Source estimates and validation with a global model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID ATMOSPHERIC CARBON-MONOXIDE; ORGANIC-COMPOUND EMISSIONS; BIOMASS BURNING EMISSIONS; FREE TROPOSPHERIC CO; ART. NO. 4100; SEASONAL-VARIATIONS; TRANSPORT MODEL; SPECTROSCOPIC MEASUREMENTS; CHEMICAL CHARACTERISTICS; INTERANNUAL VARIABILITY AB [1] We present a model study of carbon monoxide for 1988-1997 using the GEOS-Chem 3-D model driven by assimilated meteorological data, with time-varying emissions from biomass burning and from fossil fuel and industry, overhead ozone columns, and methane. The hydroxyl radical is calculated interactively using a chemical parameterization to capture chemical feedbacks. We document the inventory for fossil fuels/industry and discuss major uncertainties and the causes of differences with other inventories that give significantly lower emissions. We find that emissions hardly change from 1988 to 1997, as increases in Asia are offset by decreases elsewhere. The model reproduces the 20% decrease in CO at high northern latitudes and the 10% decrease in the North Pacific, caused primarily by the decrease in European emissions. The model compares well with observations at sites impacted by fossil fuel emissions from North America, Europe, and east Asia suggesting that the emissions from this source are reliable to 25%, and we argue that bottom-up emission estimates are likely to be too low rather than too high. The model is too low at the seasonal maximum in spring in the southern tropics, except for locations in the Atlantic Ocean. This problem may be caused by an overestimate of the frequency of tropical deep convection, a common problem in models that use assimilated meteorological data. We argue that the yield of CO from methane oxidation is near unity, contrary to some other studies, based on removal rates of intermediate species. C1 Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 02138 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Duncan, BN (reprint author), Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 02138 USA. EM bryan.n.duncan@nasa.gov RI Duncan, Bryan/A-5962-2011; Jones, Nicholas/G-5575-2011; Yantosca, Robert/F-7920-2014; Chem, GEOS/C-5595-2014 OI Jones, Nicholas/0000-0002-0111-2368; Yantosca, Robert/0000-0003-3781-1870; NR 177 TC 150 Z9 152 U1 3 U2 31 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 17 PY 2007 VL 112 IS D22 AR D22301 DI 10.1029/2007JD008459 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 232ZS UT WOS:000251060800005 ER PT J AU Li, ZQ Chen, H Cribb, M Dickerson, R Holben, B Li, C Lu, D Luo, Y Maring, H Shi, G Tsay, SC Wang, P Wang, Y Xia, X Zheng, Y Yuan, T Zhao, F AF Li, Zhanqing Chen, H. Cribb, M. Dickerson, R. Holben, B. Li, C. Lu, D. Luo, Y. Maring, H. Shi, G. Tsay, S. -C. Wang, P. Wang, Y. Xia, X. Zheng, Y. Yuan, T. Zhao, F. TI Preface to special section on east Asian studies of tropospheric aerosols: An international regional experiment (EAST-AIRE) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material ID CROP YIELDS; ACE-ASIA; OPTICAL-PROPERTIES; SOLAR-RADIATION; CHINA; CLIMATE; POLLUTION; PACIFIC; TRANSPORT; CARBON AB [1] Papers published in this special section report findings from the East Asian Study of Tropospheric Aerosols: An International Regional Experiment (EAST-AIRE). They are concerned with (1) the temporal and spatial distributions of aerosol loading and precursor gases, (2) aerosol single scattering albedo (SSA), (3) aerosol direct radiative effects, (4) validation of satellite products, (5) transport mechanisms, and (6) the effects of air pollution on ecosystems. Aerosol loading is heaviest in mideastern China with a mean aerosol optical depth (AOD) of 0.5 and increasing to 0.7 around major cities that reduced daily mean surface solar radiation by similar to 30-40 W m(-2), but barely changed solar reflection at the top of the atmosphere. Aerosol loading, particle size and composition vary considerably with location and season. The MODIS AOD data from Collection 5 (C5) agree much better with ground data than earlier releases, but considerable discrepancies still exist because of treatments of aerosol SSA and surface albedo. Four methods are proposed/adopted to derive the SSA by means of remote sensing and in situ observation, which varies drastically with time and space. The nationwide means of AOD, angstrom ngstrom exponent, and SSA (0.5 mu m) in China are 0.69 +/- 0.17, 1.06 +/- 0.26, and 0.89 +/- 0.04, respectively. Measurements of trace gases reveal substantial uncertainties in emission inventories. An analysis of aircraft measurements revealed that dry convection is an important mechanism uplifting pollutants over northern China. Model simulations of nitrogen deposition and impact of ozone pollution on net primary productivity indicate an increasing threat of air pollution on the ecosystem. C1 Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China. Nanjing Univ Informat Sci & Technol, Sch Environm Sci & Engn, Nanjing, Peoples R China. NASA, Goddard Space Flight Ctr, Lab Atmosphere, Greenbelt, MD 20771 USA. Natl Sci Fdn, Div Earth Sci, Beijing, Peoples R China. NASA Headquarters, Washington, DC USA. Natl Satellite Meteorolog Ctr, China Meteorolog Adm, Beijing, Peoples R China. RP Li, ZQ (reprint author), Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. EM zli@atmos.umd.edu RI Xia, Xiangao/G-5545-2011; LUO, Yong/I-6132-2013; Dickerson, Russell/F-2857-2010; Yuan, Tianle/D-3323-2011; Li, Can/F-6867-2011; Cribb, Maureen/K-1341-2013; Li, Zhanqing/F-4424-2010; Tsay, Si-Chee/J-1147-2014 OI Xia, Xiangao/0000-0002-4187-6311; Dickerson, Russell/0000-0003-0206-3083; Cribb, Maureen/0000-0002-9745-3676; Li, Zhanqing/0000-0001-6737-382X; NR 87 TC 110 Z9 123 U1 2 U2 29 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 17 PY 2007 VL 112 IS D22 AR D22S00 DI 10.1029/2007JD008853 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 232ZS UT WOS:000251060800007 ER PT J AU Zhang, YC Rossow, WB Stackhouse, P Romanou, A Wielicki, BA AF Zhang, Yuanchong Rossow, William B. Stackhouse, Paul, Jr. Romanou, Anastasia Wielicki, Bruce A. TI Decadal variations of global energy and ocean heat budget and meridional energy transports inferred from recent global data sets SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID FLUX; VARIABILITY; LATENT; ATMOSPHERE; SURFACE; ISCCP AB [1] We use the most recent global, decades-long data sets, consisting of two satellite-derived top-of-atmosphere (TOA) and surface radiative flux data sets from the International Satellite Cloud Climatology Project Flux product (ISCCP-FD) and the Global Energy and Water Cycle Experiment Surface Radiation Budget project (GEWEXSRB), three ocean surface turbulent flux data sets from Goddard Satellite-based Surface Turbulent Fluxes (GSSTF), Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite data ( HOAPS) and Woods Hole Oceanographic Institution Objectively Analyzed air-sea Fluxes (WHOI) and one ocean heat content (or energy storage rate) data set from Willis et al. to investigate what can be learned about how decadal-scale variations of the global energy budget at TOA are partitioned between the atmosphere and ocean and their mean meridional heat transports. Although the mean differences among the TOA radiative flux data sets are large enough that direct measurements of planetary energy imbalances are still unreliable, comparison of the interannual anomalies of the ocean heat content with the two (satellite-derived) planetary energy imbalances converted to accumulated ocean heat content (or equivalently comparison of the anomalies of ocean heat content converted to ocean heat storage rate with the planetary energy imbalances) show excellent quantitative agreement. These data sets essentially show a heating of the upper ocean since the 1990s but different "trends'' at the beginning of this century that need further investigation. The comparison of interannual anomalies of total ocean surface energy fluxes converted to accumulated ocean heat content do not show such good agreement, the former generally indicating a cooling over the past decade. The fact that the anomalies in surface net radiative heating are slightly too large suggests that the latent heat flux anomalies are also too large (causing an overall cooling). The interannual anomalies of the mean meridional heat transport by the atmosphere-ocean system inferred from the two TOA radiative flux data sets all show similar patterns of weakened poleward transport associated with El Nino events. Each event is different in character. The most interesting difference suggested by the latitudinal patterns is that some heat transport anomalies appear in the atmosphere and some in the ocean, but the current quality of the surface turbulent energy flux data sets precludes confirmation. Although not completely successful, we believe that this analysis indicates that these products are somewhat better than might have been expected and that the goal of further work should now be to reduce their uncertainties enough to diagnose the variations of the coupling of the atmosphere and ocean heat exchanges and transports over decadal timescales. C1 Columbia Univ, NASA, Goddard Inst Space Studies, Dept Appl Phys & Appl Math, New York, NY 10025 USA. CUNY City Coll, Cooperat Remote Sensing Sci & Technol, New York, NY 10031 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Zhang, YC (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, Dept Appl Phys & Appl Math, New York, NY 10025 USA. EM yzhang@giss.nasa.gov RI Rossow, William/F-3138-2015 NR 28 TC 14 Z9 14 U1 1 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 17 PY 2007 VL 112 IS D22 AR D22101 DI 10.1029/2007JD008435 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 232ZS UT WOS:000251060800004 ER PT J AU Bailey, AE Poon, WCK Christianson, RJ Schofield, AB Gasser, U Prasad, V Manley, S Segre, PN Cipelletti, L Meyer, WV Doherty, MP Sankaran, S Jankovsky, AL Shiley, WL Bowen, JP Eggers, JC Kurta, C Lorik, T Pusey, PN Weitz, DA AF Bailey, A. E. Poon, W. C. K. Christianson, R. J. Schofield, A. B. Gasser, U. Prasad, V. Manley, S. Segre, P. N. Cipelletti, L. Meyer, W. V. Doherty, M. P. Sankaran, S. Jankovsky, A. L. Shiley, W. L. Bowen, J. P. Eggers, J. C. Kurta, C. Lorik, T., Jr. Pusey, P. N. Weitz, D. A. TI Spinodal decomposition in a model colloid-polymer mixture in microgravity SO PHYSICAL REVIEW LETTERS LA English DT Article ID LIGHT-SCATTERING; PHASE-SEPARATION; BINARY-FLUID; MICROSCOPY; PHYSICS AB We study phase separation in a deeply quenched colloid-polymer mixture in microgravity on the International Space Station using small-angle light scattering and direct imaging. We observe a clear crossover from early-stage spinodal decomposition to late-stage, interfacial-tension-driven coarsening. Data acquired over 5 orders of magnitude in time show more than 3 orders of magnitude increase in domain size, following nearly the same evolution as that in binary liquid mixtures. The late-stage growth approaches the expected linear growth rate quite slowly. C1 Harvard Univ, Dept Phys, SEAS, Cambridge, MA 02138 USA. Univ Edinburgh, Sch Phys, Edinburgh EH9 3JZ, Midlothian, Scotland. NASA, Glenn Res Ctr, Natl Ctr Microgravity Res, Cleveland, OH 44135 USA. Zin Technol Inc, Brookpark, OH 44142 USA. RP Bailey, AE (reprint author), Harvard Univ, Dept Phys, SEAS, Cambridge, MA 02138 USA. RI Manley, Suliana/D-3818-2012; Poon, Wilson/B-5960-2013; Sankaran, Subramanian/L-8416-2013 OI Manley, Suliana/0000-0002-4755-4778; Poon, Wilson/0000-0003-0760-7940; Sankaran, Subramanian/0000-0002-8990-4107 NR 27 TC 50 Z9 50 U1 3 U2 23 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 16 PY 2007 VL 99 IS 20 AR 205701 DI 10.1103/PhysRevLett.99.205701 PG 4 WC Physics, Multidisciplinary SC Physics GA 232FL UT WOS:000251003600039 PM 18233160 ER PT J AU Bakunov, MI Maslov, AV Bodrov, SB AF Bakunov, M. I. Maslov, A. V. Bodrov, S. B. TI Fresnel formulas for the forced electromagnetic pulses and their application for optical-to-terahertz conversion in nonlinear crystals SO PHYSICAL REVIEW LETTERS LA English DT Article ID GENERATION; RECTIFICATION; BEAM AB We show that the usual Fresnel formulas for a free-propagating pulse are not applicable for a forced terahertz electromagnetic pulse supported by an optical pulse at the end of a nonlinear crystal. The correct linear reflection and transmission coefficients that we derive show that such pulses can experience a gain or loss at the boundary. This energy change depends on linear dielectric constants only. We also predict a regime where a complete disappearance of the forced pulse under oblique incidence occurs, an effect that has no counterpart for free-propagating pulses. C1 Univ Nizhny Novgorod, Dept Radio Phys, Nizhnii Novgorod 603950, Russia. Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603600, Russia. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bakunov, MI (reprint author), Univ Nizhny Novgorod, Dept Radio Phys, Nizhnii Novgorod 603950, Russia. RI Maslov, Alexey/E-5158-2011; Bodrov, Sergey/D-1962-2012; Bakunov, Michael/E-2875-2017 OI Maslov, Alexey/0000-0002-7835-2474; Bakunov, Michael/0000-0002-4209-1372 NR 9 TC 10 Z9 10 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 16 PY 2007 VL 99 IS 20 AR 203904 DI 10.1103/PhysRevLett.99.203904 PG 4 WC Physics, Multidisciplinary SC Physics GA 232FL UT WOS:000251003600021 PM 18233142 ER PT J AU Watters, TR Campbell, B Carter, L Leuschen, CJ Plaut, JJ Picardi, G Orosei, R Safaeinili, A Clifford, SM Farrell, WM Ivanov, AB Phillips, RJ Stofan, ER AF Watters, Thomas R. Campbell, Bruce Carter, Lynn Leuschen, Carl J. Plaut, Jeffrey J. Picardi, Giovanni Orosei, Roberto Safaeinili, Ali Clifford, Stephen M. Farrell, William M. Ivanov, Anton B. Phillips, Roger J. Stofan, Ellen R. TI Radar sounding of the Medusae Fossae Formation Mars: Equatorial ice or dry, low-density deposits? SO SCIENCE LA English DT Article ID GLOBAL SURVEYOR; ORBITER CAMERA; THARSIS; REGION; SUBSURFACE; RECORD AB The equatorial Medusae Fossae Formation (MFF) is enigmatic and perhaps among the youngest geologic deposits on Mars. They are thought to be composed of volcanic ash, eolian sediments, or an ice-rich material analogous to polar layered deposits. The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument aboard the Mars Express Spacecraft has detected nadir echoes offset in time-delay from the surface return in orbits over MFF material. These echoes are interpreted to be from the subsurface interface between the MFF material and the underlying terrain. The delay time between the MFF surface and subsurface echoes is consistent with massive deposits emplaced on generally planar lowlands materials with a real dielectric constant of similar to 2.9 +/- 0.4. The real dielectric constant and the estimated dielectric losses are consistent with a substantial component of water ice. However, an anomalously low-density, ice-poor material cannot be ruled out. If ice-rich, the MFF must have a higher percentage of dust and sand than polar layered deposits. The volume of water in an ice-rich MFF deposit would be comparable to that of the south polar layered deposits. 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 Carter, Lynn/D-2937-2012; Farrell, William/I-4865-2013; Ivanov, Anton/C-8944-2014 OI Ivanov, Anton/0000-0001-8376-8581 NR 24 TC 70 Z9 71 U1 1 U2 8 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 16 PY 2007 VL 318 IS 5853 BP 1125 EP 1128 DI 10.1126/science.1148112 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 231OC UT WOS:000250957900042 PM 17975034 ER PT J AU Hakami, A Henze, DK Seinfeld, JH Singh, K Sandu, A Kim, ST Byun, DW Li, QB AF Hakami, Amir Henze, Daven K. Seinfeld, John H. Singh, Kumaresh Sandu, Adrian Kim, Soontae Byun, Daewon Li, Qinbin TI The adjoint of CMAQ SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID VARIATIONAL DATA ASSIMILATION; 3-DIMENSIONAL PHOTOCHEMICAL MODEL; CHEMISTRY DATA ASSIMILATION; DIRECT SENSITIVITY-ANALYSIS; CHEMICAL KINETIC SYSTEMS; DECOUPLED DIRECT METHOD; AIR-QUALITY MODELS; NON-LINEAR SYSTEMS; METEOROLOGICAL OBSERVATIONS; ATMOSPHERIC MODELS AB An adjoint model for the internationally used Community Multiscale Air Quality (CMAQ) modeling platform of the U.S. EPA is developed. The adjoint version for CMAG (CMAQ-ADJ) provides the user community with forward (decoupled direct method or DDM) and backward (adjoint) sensitivity analysis capabilities. Current implementation is for gasphase processes. Discrete adjoints are implemented for all processes with the exception of horizontal advection, for which, because of inherent discontinuities in the advection scheme, the continuous approach is superior. The adjoint of chemistry is. constructed by interfacing CMAG with the kinetic pre-processor, which provides for increased flexibility in the choice of chemical solver and facilitates the implementation of new chemical mechanisms. The adjoint implementation is evaluated both on a process-by-process basis and for the full model. In general, adjoint results show good agreement with brute-force and DDM sensitivities, As expected for a continuous adjoint implementation in a nonlinear scheme, the agreement is not perfect for horizontal transport. Sensitivities of various air quality, public health, and environmental metrics with respect to emissions are calculated using the adjoint method In order to show applicability to regional climate studies, as an example, the sensitivities of these metrics with respect to local temperatures are calculated. C1 CALTECH, Dept Chem Engn, Pasadena, CA 91125 USA. Virginia Polytech Inst & State Univ, Dept Comp Sci, Blacksburg, VA 24061 USA. Univ Houston, Dept Geosci, Houston, TX 77204 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Seinfeld, JH (reprint author), CALTECH, Dept Chem Engn, 1200 E Calif Blvd, Pasadena, CA 91125 USA. EM seinfeld@caltech.edu RI Singh, Kumaresh/P-4857-2016; Henze, Daven/A-1920-2012 NR 66 TC 46 Z9 46 U1 1 U2 31 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X EI 1520-5851 J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD NOV 15 PY 2007 VL 41 IS 22 BP 7807 EP 7817 DI 10.1021/es070944p PG 11 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 231UM UT WOS:000250974700035 PM 18075092 ER PT J AU Warren, A Chappell, A Todd, MC Bristow, C Drake, N Engelstaedter, S Martins, V M'bainayel, S Washington, R AF Warren, Andrew Chappell, Adrian Todd, Martin C. Bristow, Charlie Drake, Nick Engelstaedter, Sebastian Martins, Vanderlei M'bainayel, Samuel Washington, Richard TI Dust-raising in the dustiest place on earth SO GEOMORPHOLOGY LA English DT Article DE low level jet; transport-limitation; self-abrasion; dune-included turbulence; Bodele; Chad ID WIND EROSION; OPTICAL-PROPERTIES; BODELE DEPRESSION; WEST-AFRICA; AEROSOL; EMISSION; SURFACE; LAKE; PARTICLES; AUSTRALIA AB The Bodele in northern Chad is the dustiest place on earth. It is dusty because of the co-location of strong near-surface winds and a large exposure of low-density, friable diatomite. Data are reported from three kinds of observation on dust generation in the Bodele: (a) two automatic weather stations and pilot balloon tracking, complemented with reanalysis data, measuring and estimating wind velocities; (b) sun-photometers, measuring atmospheric dust concentrations; (c) a vacuum-pump dust sampler and an array of MWAC sediment samplers, measuring in-situ sediment transport. With these data, we develop four hypotheses about dust generation: (1) the pulsing of dust output from the Bodele depends primarily on the varying strength of a Low Level Jet (LLJ); i.e., at this scale, dust production is transport-limited; (2) the most prolific mechanism of dust production is the breakdown of saltating diatomite flakes as they collide with each other and with the surface; (3) disturbance of flow around the large barchans, particularly turbulence and convergence on their "horns", is a major contributor to dust production, i.e., the dunes are "dust-mills"; (4) in consequence, dust production is localised within the main exposure of diatomite to places where there are the most dunes, as on the eastern and northern fringes of the exposure. (c) 2007 Elsevier B.V. All rights reserved. C1 [Warren, Andrew; Todd, Martin C.] UCL, Dept Geog, London WC1E 6BT, England. [Chappell, Adrian] Univ Salford, Sch Environm & Life Sci, Salford M5 4WT, Lancs, England. [Bristow, Charlie] Univ London Birkbeck Coll, Sch Earth Sci, London WC1E 7HX, England. [Drake, Nick] Kings Coll London, Dept Geog, London WC2R 2LS, England. [Engelstaedter, Sebastian; Washington, Richard] Univ Oxford, Oxford Univ Ctr Environm, Climate Res Lab, Oxford X1 3QY, England. [Martins, Vanderlei] Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [M'bainayel, Samuel] DREM, Ndjamena, Chad. RP Warren, A (reprint author), UCL, Dept Geog, Gower St, London WC1E 6BT, England. EM a.warren@ucl.ac.uk RI Engelstaedter, Sebastian/A-9599-2009; Bristow, Charlie/F-1979-2011; Chappell, Adrian/A-7058-2011; todd, martin/I-4143-2015; OI Chappell, Adrian/0000-0002-0694-7348; Engelstaedter, Sebastian/0000-0001-9315-580X NR 43 TC 44 Z9 44 U1 0 U2 7 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 15 PY 2007 VL 92 IS 1-2 BP 25 EP 37 DI 10.1016/j.geomorph.2007.02.007 PG 13 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 244VB UT WOS:000251892300003 ER PT J AU Thomson, BJ Schultz, PH AF Thomson, Bradley J. Schultz, Peter H. TI The geology of the Viking Lander 2 site revisited SO ICARUS LA English DT Review DE Mars; Mars, surface; geological processes; cratering ID THERMAL EMISSION SPECTROMETER; MARTIAN NORTHERN PLAINS; PATHFINDER LANDING SITE; MARS PATHFINDER; WIND EROSION; PHYSICAL-PROPERTIES; PLANETARY SURFACES; PEDESTAL CRATERS; CLIMATE-CHANGE; ISIDIS BASIN AB Reevaluating the geologic history of the prior Mars landing sites provides important ground truth for recent and ongoing orbital missions. At the Viking 2 Lander (VL2) site, topographic measurements of relict landforms indicate that at least 100 m of sedimentary mantle material has been stripped away. The observed paucity of impact craters < 100 m in diameter suggests that resurfacing processes (likely in the form of the recent deposition and removal of thin 1-10 m mantle layers) continue up to the present. A dearth of craters in the 100-500 m diameter range, however, also necessitates erosion of a thicker mantle layer. Partially inverted chains of secondary craters from nearby Mie Crater indicate that the mantle was already in place when the impact occurred. The density of craters superposed on Mie ejecta is consistent with a Late Hesperian age and provides a minimum age constraint for the mantle's emplacement. The thermophysical properties of the surface around VL2 as observed with Thermal Emission Imaging System (THEMIS) data indicate that the landing site occurs in an intracrater region that may typify mid to high northern latitude sites. Elevated thermal inertias of a pedestal crater superposed atop a larger pedestal crater suggest that rocky or indurated material can be created by impacts into sedimentary targets. Rock abundances at VL2 are consistent with the addition of impact-emplaced material from the missing small impact crater population documented in this study. Thus, the VL2 site may be a reasonable proxy for the landscape expected at the upcoming Phoenix Lander site. (C) 2007 Elsevier Inc. All rights reserved. C1 [Thomson, Bradley J.] CALTECH, NASA, Jet Propuls Lab, Pasadena, CA 91109 USA. [Schultz, Peter H.] Brown Univ, Dept Geosci, Providence, RI 02912 USA. RP Thomson, BJ (reprint author), CALTECH, NASA, Jet Propuls Lab, Mail Stop 183-501,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM bradley.j.thomson@jpl.nasa.gov OI Thomson, Bradley/0000-0001-8635-8932 NR 108 TC 5 Z9 5 U1 1 U2 5 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 NOV 15 PY 2007 VL 191 IS 2 BP 505 EP 523 DI 10.1016/j.icarus.2007.05.011 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 240LQ UT WOS:000251589500008 ER PT J AU Altobelli, N Spilker, L Pilorz, S Brooks, S Edgington, S Wallis, B Flasar, M AF Altobelli, N. Spilker, L. Pilorz, S. Brooks, S. Edgington, S. Wallis, B. Flasar, M. TI C ring fine structures revealed in the thermal infrared SO ICARUS LA English DT Article DE planetary rings; Saturn, rings; spectroscopy ID SATURNS RINGS; PLANETARY REGOLITHS; ATMOSPHERELESS BODIES; STELLAR OCCULTATION; RADIATIVE-TRANSFER; ENERGY-TRANSFER; MODEL; ASTEROIDS; SURFACES; PHYSICS AB We analyze data sets obtained with the Composite Infrared Spectrometer (CIRS) onboard the Cussini spacecraft after the Saturn Orbit Insertion (SOI), Using the mid-IR interferometer's FP3 channel (600-1100 cm(-1)), we derive radial temperature profiles for the C ring with a spatial resolution never achieved before, For the first time, the C ring's plateaus and ringlets can be clearly separated from the optically thinner background and their thermal behavior is studied separately for different viewing geometries, In particular, thermal phase curves derived for the plateaus reveal tin interesting surge near 0 degrees phase, not observed in the background, We show that mutual shadowing in the plateaus can explain the existence of the surge but is not sufficient to model the phase curves in detail. By analogy with thermal emission of asteroid surfaces we discuss the possible influence of small scale and large scale roughness of the ring structure itself, Because infrared emissivity cannot be derived without being deconvolved from the 'structural' filling factor, we examine temperature and filling factors measurements at opposition where the tilling factor is most constrained, The occurrence of higher temperatures in the plateaus than in the background near opposition likely arises from enhanced mutual heating between particles, multiple scattering and surface roughness combined with a higher albedo. Published by Elsevier Inc. C1 [Altobelli, N.; Spilker, L.; Pilorz, S.; Brooks, S.; Edgington, S.; Wallis, B.] NASA, JPL, Pasadena, CA 91109 USA. [Flasar, M.] Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Altobelli, N (reprint author), NASA, JPL, 4800 Oak Grove Dr,Mail Stop 230-205, Pasadena, CA 91109 USA. EM nleolas.altobelli@jpl.nasa.gov RI Flasar, F Michael/C-8509-2012 NR 35 TC 14 Z9 14 U1 0 U2 1 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 NOV 15 PY 2007 VL 191 IS 2 BP 691 EP 701 DI 10.1016/j.icarus.2007.06.014 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 240LQ UT WOS:000251589500020 ER PT J AU Cassidy, TA Johnson, RE McGrath, MA Wong, MC Cooper, JE AF Cassidy, T. A. Johnson, R. E. McGrath, M. A. Wong, M. C. Cooper, J. E. TI The spatial morphology of Europa's near-surface O-2 atmosphere SO ICARUS LA English DT Article DE Europa; regoliths; satellites; atmospheres; satellites; surfaces ID ICY GALILEAN SATELLITES; OXYGEN ATMOSPHERE; ION; REDISTRIBUTION; BOMBARDMENT; EROSION AB Results from a three-dimensional ballistic model of Europa's O-2 atmosphere are presented. Hubble Space Telescope (HST) ultraviolet observations show spatially non-uniform O-2 airglow from Europa. One explanation for this is that the O-2 atmosphere is spatially non-uniform. We show that non-uniform ejection Of O-2 alone cannot reproduce the required morphology, but that a non-uniform distribution of reactive species in Europa's porous regolith can result in a non-uniform O-2 atmosphere. By allowing O-2 molecules to react with Europa's visibly dark surface material, we produced a spatially non-uniform atmosphere which, assuming uniform electron excitation of O-2 over the trailing hemisphere, compares favorably with the morphology suggested by the HST observations. This model, which requires a larger source of O-2 than has previously been estimated, can in principal be tested by the New Horizons observations of Europa's O-2 atmosphere. (c) 2007 Elsevier Inc. All rights reserved. C1 [Cassidy, T. A.; Johnson, R. E.] Univ Virginia, Engn Phys Program, Charlottesville, VA 22904 USA. [Cassidy, T. A.; Johnson, R. E.] Univ Virginia, Dept Astron, Charlottesville, VA 22904 USA. [McGrath, M. A.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Wong, M. C.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Cooper, J. E.] NASA, Goddard Space Flight Ctr, Heliospher Phys Lab, Greenbelt, MD 20771 USA. RP Cassidy, TA (reprint author), Univ Virginia, Engn Phys Program, POB 400325, Charlottesville, VA 22904 USA. EM tae2z@virginia.edu RI Cooper, John/D-4709-2012 NR 38 TC 31 Z9 31 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 J9 ICARUS JI Icarus PD NOV 15 PY 2007 VL 191 IS 2 BP 755 EP 764 DI 10.1016/j.icarus.2007.04.033 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 240LQ UT WOS:000251589500026 ER PT J AU Heinrich, MN Khare, BN Mckay, CP AF Heinrich, Michael N. Khare, Bishun N. Mckay, Christopher P. TI Prebiotic organic synthesis in early Earth and Mars atmospheres: Laboratory experiments with quantitative determination of products formed in a cold plasma flow reactor SO ICARUS LA English DT Article DE astrobiology; atmospheres; chemistry; Earth; exobiology; Mars; organic chemistry; prebiotic chemistry; prebiotic environments; triton ID CHEMICAL EVOLUTION; HYDROGEN-CYANIDE; AMINO-ACIDS; ARCHEAN ATMOSPHERE; PRIMITIVE EARTH; TITAN; HCN; CONDENSATION; CO2; PHOTOCHEMISTRY AB The goal of this study was to explore prebiotic chemistry in a range of plausible early Earth and Mars atmospheres. To achieve this laboratory continuous flow plasma irradiation experiments were performed on N-2/H-2/CO/CO2 gas mixtures chosen to represent mildly reducing early Earth and Mars atmospheres derived from a secondary volcanic outgassing of volatiles in chemical equilibrium with magmas near present day oxidation state. Under mildly reducing conditions (91.79% N-2, 5.89% H-2, 2.21 % CO, and 0. 11% CO2), simple nitriles are produced in the gas phase with yield (G in molecules per 100 eV), for the key prebiotic marker molecule HCN at G similar to 1 x 10(-3) (0.1 nmol J(-1)). In this atmosphere localized HCN concentrations possibly could approach the 10(-2) M needed for HCN oligomerization. Yields under mildly oxidizing conditions (45.5% N-2, 0.1 % H-2, 27.2% CO, 27.2% CO2) are significantly less as expected, with HCN at G similar to 3 x 10(-5) (3 x 10(-3) nmol J(-1)). Yields in a Triton atmosphere which can be plausibly extrapolated to represent what might be produced in trace CH4 conditions (99.9% N-2, 0.1% CH4) are significant with HCN at G similar to 1 x 10(-2) (1 nmol J(-1)) and tholins produced. Recently higher methane abundance atmospheres have been examined for their greenhouse warming potential, and higher abundance hydrogen atmospheres have been proposed based on a low early Earth exosphere temperature. A reducing (64.04% N-2, 28.8% H-2, 3.60% CO2, and 3.56% CH4), representing a high CH4 and H-2 abundance early Earth atmosphere had HCN yields of G similar to 5 x 10(-3) (0.5 nmol J(-1)). Tholins generated in high methane hydrogen gas mixtures is much less than in a similar mixture without hydrogen. The same mixture with the oxidizing component CO2 removed (66.43% N-2, 29.88% H-2, 0% CO2, and 3.69% CH4) had HCN yields of G - 1 X 10(-3) (0.1 nmol J(-1)) but more significant tholin yields. Published by Elsevier Inc. C1 [Heinrich, Michael N.] Geomet Consulting, Excelsior, MN USA. [Khare, Bishun N.; Mckay, Christopher P.] NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. RP Heinrich, MN (reprint author), Geomet Consulting, 10 Lakeview Ave, Excelsior, MN USA. EM mheinrich@geometricconsulting.com NR 59 TC 6 Z9 6 U1 2 U2 15 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 NOV 15 PY 2007 VL 191 IS 2 BP 765 EP 778 DI 10.1016/j.icarus.2007.05.017 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 240LQ UT WOS:000251589500027 ER PT J AU Shaddock, DA AF Shaddock, Daniel A. TI Digitally enhanced heterodyne interferometry SO OPTICS LETTERS LA English DT Article ID DETECTORS AB Combining conventional interferometry with digital modulation allows interferometric signals to be isolated based on their delay. This isolation capability can be exploited in two ways. First, it can improve measurement sensitivity by reducing contamination by spurious interference. Second, it allows multiple optical components to be measured using a single metrology system. Digitally enhanced interferometry employs a pseudorandom noise (PRN) code phase modulated onto the light source. Individual reflections are isolated based on their respective delays by demodulation with the PRN code with a matching delay. The properties of the PRN code determine the degree of isolation while preserving the full interferometric sensitivity determined by the optical wavelength. Analysis and simulation indicate that errors caused by spurious interference can be reduced by a factor inversely proportional to the PRN code length. (c) 2007 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shaddock, DA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Daniel.Shaddock@jpl.naso.gov RI Shaddock, Daniel/A-7534-2011 OI Shaddock, Daniel/0000-0002-6885-3494 NR 11 TC 33 Z9 33 U1 1 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 15 PY 2007 VL 32 IS 22 BP 3355 EP 3357 DI 10.1364/OL.32.003355 PG 3 WC Optics SC Optics GA 242SZ UT WOS:000251747600045 PM 18026306 ER PT J AU Shindell, D AF Shindell, Drew TI Estimating the potential for twenty-first century sudden climate change SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT Climate Change and Urban Areas Conference CY APR 03, 2006 CL Univ Coll London, London, ENGLAND HO Univ Coll London DE rapid climate change; water cycle; solar variability; ice sheets; abrupt climate change; sea-level rise ID GREENLAND ICE-SHEET; NORTH-ATLANTIC; EAST-AFRICA; THERMOHALINE CIRCULATION; METHANE EMISSIONS; LATE PLEISTOCENE; UNITED-STATES; LATE HOLOCENE; ART.; SURFACE AB I investigate the potential for sudden climate change during the current century. This investigation takes into account evidence from the Earth's history, from climate models and our understanding of the physical processes governing climate shifts. Sudden alterations to climate forcing seem to be improbable, with sudden changes instead most likely to arise from climate feedbacks. Based on projections from models validated against historical events, dramatic changes in ocean circulation appear unlikely. Ecosystem climate feedbacks clearly have the potential to induce sudden change, but are relatively poorly understood at present. More probable sudden changes are large increases in the frequency of summer heatwaves and changes resulting from feedbacks involving hydrology. These include ice sheet decay, which may be set in motion this century. The most devastating consequences are likely to occur further in the future, however. Reductions in subtropical precipitation are likely to be the most severe hydrologic effects this century, with rapid changes due to the feedbacks of relatively well-understood large-scale circulation patterns. Water stress may become particularly acute in the Southwest US and Mexico, and in the Mediterranean and Middle East, where rainfall decreases of 10 25% (regionally) and up to 40% (locally) are projected. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Shindell, D (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM dshindell@giss.nasa.gov RI Shindell, Drew/D-4636-2012 NR 73 TC 16 Z9 16 U1 1 U2 11 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X EI 1471-2962 J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD NOV 15 PY 2007 VL 365 IS 1860 BP 2675 EP 2694 DI 10.1098/rsta.2007.2088 PG 20 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 214RZ UT WOS:000249757100005 PM 17666384 ER PT J AU Gregg, WW Casey, NW AF Gregg, Watson W. Casey, Nancy W. TI Sampling biases in MODIS and SeaWiFS ocean chlorophyll data SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE ocean color; sampling; data assimilation; ocean chlorophyll ID IN-SITU; COLOR; PHYTOPLANKTON; CLIMATOLOGIES; CLIMATE; TRENDS; ERA AB Although modern ocean color sensors, such as MODIS and SeaWiFS, are often considered global missions, in reality it takes many days, even months, to sample the ocean surface enough to provide complete global coverage. The irregular temporal sampling of ocean color sensors can produce biases in monthly and annual mean chlorophyll estimates. We quantified the biases due to sampling using data assimilation to create a "truth field", which we then sub-sampled using the observational patterns of MODIS and SeaWiFS. Monthly and annual mean chlorophyll estimates from these sub-sampled, incomplete daily fields were constructed and compared to monthly and annual means from the complete daily fields of the assimilation model, at a spatial resolution of 1.25 degrees longitude by 0.67 degrees latitude. The results showed that global annual mean biases were positive, reaching nearly 8% (MODIS) and > 5% (SeaWiFS). For perspective the maximum interannual variability in the SeaWiFS chlorophyll record was about 3%. Annual mean sampling biases were low (< 3%) in the mid-latitudes (between -40 degrees and 40). Low interannual variability in the global annual mean sampling biases suggested that global scale trend analyses were valid. High latitude biases were much higher than the global annual means, up to 20% as a basin annual mean, and over 80% in some months. This was the result of the high solar zenith angle exclusion in the processing algorithms. Only data where the solar angle is < 75 degrees are permitted, in contrast to the assimilation which samples regularly over the entire area and month. High solar zenith angles do not facilitate phytoplankton photosynthesis and low chlorophyll concentrations occurring here are missed by the data sets. Ocean color sensors selectively sample in locations and times of favorable phytoplankton growth, producing overestimates of chlorophyll. The biases derived from lack of sampling in the high latitudes varied monthly, leading to artifacts in the apparent seasonal cycle from ocean color sensors. A false secondary peak in chlorophyll occurred in May-August, which resulted from lack of sampling in the Antarctic. Persistent clouds, characteristic in the North Pacific, also produced overestimates, again by selectively sampling only the high growth periods. In contrast, areas characterized by thick aerosols showed chlorophyll underestimates to nearly -30% in basin monthly means. This was the result of selective sampling in lower aerosol thickness periods, which corresponded with lower phytoplankton growth periods. A combination of MODIS and SeaWiFS sampling was most effective at reducing mid-latitude biases due to inter-orbit gaps, sun glint, and sensor tilt changes. But these biases were low using a single sensor, suggesting multiple sensors had little effect in reducing global and regional monthly and annual mean biases. Ocean color data are an invaluable source of information about global biological processes. However, these results suggest that sampling errors need to be considered in applications involving global and regional mean chlorophyll biomasses as well as seasonal variability and regional trend analysis. (c) 2007 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Gregg, WW (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. EM nancy.casey@gsfc.nasa.gov NR 22 TC 33 Z9 33 U1 4 U2 12 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 NOV 15 PY 2007 VL 111 IS 1 BP 25 EP 35 DI 10.1016/j.rse.2007.03.008 PG 11 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 221QX UT WOS:000250243500003 ER PT J AU Morel, A Huot, Y Gentili, B Werdell, PJ Hooker, SB Franz, BA AF Morel, Andre Huot, Yannick Gentili, Bernard Werdell, P. Jeremy Hooker, Stanford B. Franz, Bryan A. TI Examining the consistency of products derived from various ocean color sensors in open ocean (Case 1) waters in the perspective of a multi-sensor approach SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE ocean color sensors; chlorophyll; attenuation coefficient; multi-sensor products; products consistency; heated layer; euphoric layer; secchi disk; merging ID CLEAREST NATURAL-WATERS; OPTICAL-PROPERTIES; BIOOPTICAL PROPERTIES; LEAVING RADIANCE; GLOBAL OCEAN; LIGHT; MODEL; REFLECTANCE; TRANSPARENCY; ABSORPTION AB During its lifetime, a space-borne ocean color sensor provides world-wide information about important biogeochemical properties of the upper ocean every 2 to 4 days in cloudless regions. Merging simultaneous or complementary data from such sensors to obtain better spatial and temporal coverage is a recurring objective, but it can only be reached if the consistency of the sensor-specific products, as delivered by the various Space Agencies, has first been carefully examined. The goal of the present study is to provide a procedure for establishing a coherency of open ocean (Case-1 waters) data products, for which the various data processing methods are sufficiently similar. The development of the procedure includes a detailed comparison of the marine algorithms used (after atmospheric corrections) by space agencies for the production of standard products, such as the chlorophyll concentration, [Ch1], and the diffuse attenuation coefficient, K-d. The MODIS-Aqua, SeaWiFS and MERIS [Ch1] products agree over a wide range, between similar to 0.1 and 3 mg m(-3), whereas increasing divergences occur for oligotrophic waters ([Ch1] (from 0.02 to 0.09 mg m(-3)). For the K-d(490) coefficient, different algorithms are in use, with differing results. Based on a semi-analytical reflectance model and hyperspectral approach, the present work proposes a harmonization of the algorithms allowing the products of the various sensors to be comparable, and ultimately, meaningfully merged (the merging procedures themselves are not examined). Additional potential products, obtained by using [Ch1] as an intermediate tool, are also examined and proposed. These products include the thickness of the layer heated by the sun, the depth of the euphotic zone, and the Secchi disk depth. The physical limitations in the predictive skill of such downward extrapolations, made from information concerning only the upper layer, are stressed. (c) 2007 Elsevier Inc. All rights reserved. C1 CNRS, Oceanog Lab, F-06238 Villefranche Sur Mer, France. Univ Paris 06, F-06238 Villefranche Sur Mer, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Morel, A (reprint author), CNRS, Oceanog Lab, BP 08, F-06238 Villefranche Sur Mer, France. EM morel@obs-vlfr.fr RI Franz, Bryan/D-6284-2012; Werdell, Jeremy/D-8265-2012; Hooker, Stanford/E-2162-2012; Huot, Yannick/B-4497-2008 OI Franz, Bryan/0000-0003-0293-2082; Huot, Yannick/0000-0003-1793-761X NR 69 TC 194 Z9 207 U1 6 U2 30 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 NOV 15 PY 2007 VL 111 IS 1 BP 69 EP 88 DI 10.1016/j.rse.2007.03.012 PG 20 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 221QX UT WOS:000250243500006 ER PT J AU Coon, M Kwok, R Levy, G Pruis, M Schreyer, H Sulsky, D AF Coon, Max Kwok, Ron Levy, Gad Pruis, Matthew Schreyer, Howard Sulsky, Deborah TI Arctic ice dynamics joint experiment (AIDJEX) assumptions revisited and found inadequate SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA-ICE; CONCENTRATION FIELDS; PREDICTION SYSTEM; MODEL AB [1] This paper revisits the Arctic Ice Dynamics Joint Experiment (AIDJEX) assumptions about pack ice behavior with an eye to modeling sea ice dynamics. The AIDJEX assumptions were that (1) enough leads were present in a 100 km by 100 km region to make the ice isotropic on that scale; (2) the ice had no tensile strength; and (3) the ice behavior could be approximated by an isotropic yield surface. These assumptions were made during the development of the AIDJEX model in the 1970s, and are now found inadequate. The assumptions were made in part because of insufficient large-scale (10 km) deformation and stress data, and in part because of computer capability limitations. Upon reviewing deformation and stress data, it is clear that a model including deformation on discontinuities and an anisotropic failure surface with tension would better describe the behavior of pack ice. A model based on these assumptions is needed to represent the deformation and stress in pack ice on scales from 10 to 100 km, and would need to explicitly resolve discontinuities. Such a model would require a different class of metrics to validate discontinuities against observations. C1 NW Res Associates, Redmond, WA USA. Jet Propuls Lab, Pasadena, CA USA. Univ New Mexico, Dept Engn, Albuquerque, NM USA. Univ New Mexico, Dept Math & Stat, Albuquerque, NM USA. RP Coon, M (reprint author), NW Res Associates, Redmond, WA USA. RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 28 TC 33 Z9 33 U1 0 U2 7 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 NOV 14 PY 2007 VL 112 IS C11 AR C11S90 DI 10.1029/2005JC003393 PG 11 WC Oceanography SC Oceanography GA 233AB UT WOS:000251061700001 ER PT J AU Kim, TH Lee, GW Gangopadhyay, AK Hyers, RW Rogers, JR Goldman, AI Kelton, KF AF Kim, T. H. Lee, G. W. Gangopadhyay, A. K. Hyers, R. W. Rogers, J. R. Goldman, A. I. Kelton, K. F. TI Structural studies of a Ti-Zr-Ni quasicrystal-forming liquid SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT International Conference on Nanoscale Order in Amorphous and Partially Ordered Solids CY JUL 09-11, 2007 CL Trinity Coll, Cambridge, ENGLAND SP FEI Co, US Natl Sci Fdn HO Trinity Coll ID INITIO MOLECULAR-DYNAMICS; BOND-ORIENTATIONAL ORDER; ELECTROSTATIC LEVITATOR; SUPERCOOLED LIQUIDS; X-RAY; PHASE; GLASSES; ALLOYS; MELTS AB Employing the technique of electrostatic levitation coupled with high-energy x-ray diffraction, Ti39.5Zr39.5Ni21 liquids were shown previously to develop significant short-range icosahedral order with supercooling. However, that conclusion was based on the assumption of a single dominant cluster type in the liquid and the observed evolution of the high-q shoulder on the second peak in the structure factor, S(q). Here, new diffraction data that were obtained using more rapid data acquisition methods are presented. These allow structural studies to be made down to and through recalescence to the icosahedral quasicrystal. The liquid structures obtained from a Reverse Monte Carlo analysis of these data are characterized by their bond-angle distributions, Honeycutt and Andersen indices and bond orientational order parameters. These analyses indicate that while there are several different types of local order, the icosahedral short-range order is dominant and increases gradually with supercooling. C1 Washington Univ, Dept Phys, Ctr Mat Innovat, St Louis, MO 63130 USA. Korea Res Inst Standards & Sci, Taejon, South Korea. Univ Massachusetts, Amherst, MA 01003 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Iowa State Univ, Ames Natl Lab, USDOE, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Kim, TH (reprint author), Washington Univ, Dept Phys, Ctr Mat Innovat, St Louis, MO 63130 USA. RI Hyers, Robert/G-3755-2010 NR 32 TC 10 Z9 10 U1 1 U2 11 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD NOV 14 PY 2007 VL 19 IS 45 AR 455212 DI 10.1088/0953-8984/19/45/455212 PG 10 WC Physics, Condensed Matter SC Physics GA 227WO UT WOS:000250688700014 ER PT J AU Li, Y Paavola, CD Kagawa, H Chan, SL Trent, JD AF Li, Y. Paavola, C. D. Kagawa, H. Chan, S. L. Trent, J. D. TI Mutant chaperonin proteins: new tools for nanotechnology SO NANOTECHNOLOGY LA English DT Article ID GROUP-II CHAPERONIN; CRYSTAL-STRUCTURE; SULFOLOBUS-SHIBATAE; NANOPARTICLE ARRAYS; ARCHAEAL CHAPERONIN; APICAL DOMAIN; NANOSTRUCTURES; THERMOSOME; TEMPLATES; FILAMENTS AB Much effort has gone into finding peptides that bind potentially useful nanoparticles, but relatively little effort has focused on the scaffolds that organize these peptides into useful nanostructures. Chaperonins are protein complexes with 14 - 18 protein subunits that self-assemble into double-ring complexes and function as scaffolds for peptides or amino acids that bind metallic and semiconductor quantum dots. The utility of chaperonins as scaffolds depends on their structure and their ability to self-assemble into double-rings and higher-order structures, such as filaments and two-dimensional arrays. To better understand the structure of chaperonins, we constructed a model of a group II chaperonin and, based on this model, genetically constructed five mutant subunits with significant deletions. We expressed these mutants as recombinant proteins and observed by native polyacrylamide gel electrophoresis (PAGE) and transmission electron microscopy (TEM) that they all self-assembled into double rings. Our model predicted and TEM confirmed that these deletions did not significantly change the 17 nm diameter of the wild-type double rings, but decreased their height and opened their central cavities. Four of the five mutants formed higher-order structures: chains of rings, bundles of chains or filaments, and two-dimensional arrays, which we suggest can be useful nanostructures. C1 SETI Inst, Mountain View, CA 94043 USA. NASA, Ames Res Ctr, Bioengn Branch, Moffett Field, CA 94035 USA. RP Li, Y (reprint author), SETI Inst, 515 N Whisman Rd, Mountain View, CA 94043 USA. EM Jonathan.D.Trent@nasa.gov NR 34 TC 7 Z9 7 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD NOV 14 PY 2007 VL 18 IS 45 AR 455101 DI 10.1088/0957-4484/18/45/455101 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 220EJ UT WOS:000250139400001 ER PT J AU Tchoul, MN Ford, WT Lolli, G Resasco, DE Arepalli, S AF Tchoul, Maxim N. Ford, Warren T. Lolli, Giulio Resasco, Daniel E. Arepalli, Sivaram TI Effect of mild nitric acid oxidation on dispersability, size, and structure of single-walled carbon nanotubes SO CHEMISTRY OF MATERIALS LA English DT Article ID PURIFICATION; FUNCTIONALIZATION; DISPERSION; DISSOLUTION; POLYMERIZATION; POLYSTYRENE; COMPOSITES; CATALYST AB Oxidation of single-walled carbon nanotubes, (SWNTs) with nitric acid increases their dispersability in water, methanol, and N,N-dimethylformamide. Two oxidation protocols, sonication in 8 M HNO3 at 40 degrees C and reflux in 2.6 M HNO3, have been examined using SWNTs produced by the CoMoCat, HiPco, and pulsed laser vaporization (PLV) methods. The dispersability of all types of nanotubes increased substantially after I h of sonication and after 2-4 h of reflux. Longer treatments resulted in little further improvement in dispersability and at reflux degraded the SWNTs. Stable dispersions of CoMoCat SWNTs in DMF at concentrations as high as 0.4 g/L were achieved without the use of surfactants or polymers. Raman spectroscopy showed greater covalent functionalization of the SWNTs by the reflux procedure that! by the sonication procedure. Concurrent with improved dispersability, oxidation resulted in smaller diameters and shorter lengths as determined from AFM images, which show mostly bundles rather than individual tubes. The lengths of SWNTs after oxidation decreased in the order PLV > HiPco > CoMoCat. Recommendations for the method of conditioning of the various types of SWNTs depend on their intended use. C1 Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA. Univ Oklahoma, Sch Chem Biol & Mat Engn, Norman, OK 73019 USA. ERC Inc, NASA, Johnson Space Ctr, Houston, TX 77058 USA. RP Ford, WT (reprint author), Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA. EM warren.ford@okstate.edu RI Arepalli, Sivaram/A-5372-2010 NR 47 TC 145 Z9 145 U1 4 U2 38 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 EI 1520-5002 J9 CHEM MATER JI Chem. Mat. PD NOV 13 PY 2007 VL 19 IS 23 BP 5765 EP 5772 DI 10.1021/cm071758l PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 229LG UT WOS:000250803900041 ER PT J AU Dalton, JB AF Dalton, J. Brad, III TI Linear mixture modeling of Europa's non-ice material based on cryogenic laboratory spectroscopy SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INFRARED MAPPING SPECTROMETER; GALILEAN SATELLITES; OPTICAL-CONSTANTS; WATER ICE; MU-M; SPECTRA; SALTS; MINERALS; CALLISTO; SURFACE AB Linear mixture modeling has been applied to Galileo Near Infrared Mapping Spectrometer (NIMS) spectra of Europa's dark, non-water-ice terrain using cryogenic laboratory spectra of hydrated compounds. Water ice alone could not account for the distorted and asymmetric spectral features attributed to water of hydration in the Europa spectrum. The modeling was conducted using cryogenic reference spectra of hexahydrite, epsomite, bloedite, sodium sulfide nonahydrate, mirabilite, magnesium sulfate dodecahydrate, sulfuric acid hydrate, and saturated brines of magnesium sulfate, sodium carbonate, and sodium sulfate. All were measured between 77 and 130K. The best model fit was attained using abundances of 14% hexahydrite, 11% bloedite, 12% mirabilite, and 62% sulfuric acid hydrate. Results indicate that sulfuric acid hydrate and hydrated sulfate salts, taken together, produce a better spectral match than either class of compound considered alone. C1 NASA, Ames Res Ctr, SETI Inst, Casl Sagan Ctr, Moffett Field, CA USA. RP Dalton, JB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 37 TC 35 Z9 35 U1 1 U2 6 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 13 PY 2007 VL 34 IS 21 AR L21205 DI 10.1029/2007GL031497 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 232ZB UT WOS:000251059100005 ER PT J AU Lary, DJ Waugh, DW Douglass, AR Stolarski, RS Newman, PA Mussa, H AF Lary, D. J. Waugh, D. W. Douglass, A. R. Stolarski, R. S. Newman, P. A. Mussa, H. TI Variations in stratospheric inorganic chlorine between 1991 and 2006 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; VALIDATION; UARS; ER-2; RECONSTRUCTION; LATITUDE; FIELDS AB A consistent time series of stratospheric inorganic chlorine Cl-y from 1991 to present is formed using space-borne observations together with neural networks. A neural network is first used to account for inter-instrument biases in HCl observations. A second neural network is used to learn the abundance of Cly as a function of HCl and CH4, and to form a time series using available HCl and CH4 measurements. The estimates of Cl-y are broadly consistent with calculations based on tracer fractional releases and previous estimates of stratospheric age of air. These new estimates of Cl-y provide a critical test for global models, which exhibit significant differences in predicted Cl-y and ozone recovery. C1 Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore Cty, Baltimore, MD 21210 USA. NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD USA. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. Univ Cambridge, Dept Chem, Cambridge, England. RP Lary, DJ (reprint author), Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore Cty, Baltimore, MD 21210 USA. RI Lary, David/A-6163-2010; Newman, Paul/D-6208-2012; Douglass, Anne/D-4655-2012; Stolarski, Richard/B-8499-2013; Waugh, Darryn/K-3688-2016 OI Newman, Paul/0000-0003-1139-2508; Stolarski, Richard/0000-0001-8722-4012; Waugh, Darryn/0000-0001-7692-2798 NR 27 TC 9 Z9 9 U1 0 U2 1 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 13 PY 2007 VL 34 IS 21 AR L21811 DI 10.1029/2007GL030053 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 232ZB UT WOS:000251059100001 ER PT J AU Murata, Y Taguchi, S Hosokawa, K Nakao, A Collier, MR Moore, TE Sato, N Yamagishi, H Yukimatu, AS AF Murata, Y. Taguchi, S. Hosokawa, K. Nakao, A. Collier, M. R. Moore, T. E. Sato, N. Yamagishi, H. Yukimatu, A. S. TI Correlative variations of the neutral atom emission in the high-altitude cusp and the fast anti-sunward convection in the low-altitude cusp SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; HIGH-LATITUDE CONVECTION; HF-RADAR OBSERVATIONS; SOLAR-WIND; SUPERDARN RADARS; PLASMA INJECTION; PROTON AURORA; POLAR CUSP; MAGNETOSHEATH PLASMA; SPECTRAL WIDTH AB [1] Recent studies have shown that the Low Energy Neutral Atom (LENA) imager on the IMAGE spacecraft in the magnetosphere detects neutral atoms coming from the direction of the high-altitude cusp. The primary source of the neutral atoms has been reported to be the entry of the ions in the cusp, but the evidence for this remains limited. Therefore we herein report the correlative variations of the neutral atom signal in the direction of the high-altitude cusp and the fast anti-sunward convection in the ionospheric cusp from an event of simultaneous observations from IMAGE/LENA and SuperDARN radar. During a period of IMF B-Z of -40 to -10 nT on 11 April 2001, LENA on IMAGE at (X-GSM, Y-GSM, Z(GSM)) similar to (4 R-E, 0 R-E, 4 R-E) observed significant enhancements of neutral atom signals in the direction of the high-altitude cusp. In concurrence with these enhancements, SuperDARN radars observed an increase in anti-sunward flow accompanied by equatorward shift of the polar cap boundary. Detailed analyses of the SuperDARN velocity data reveal that the fast anti- sunward flow region widens and shrinks longitudinally in correlation with the increase and decrease of the LENA signal, respectively. This correlation shows that the neutral atom emission in the direction of the high-altitude cusp for southward IMF is due to the ion entry caused by enhanced reconnection on the dayside magnetopause. Hence the present study provides evidence of the cusp ion injection being the primary source of the LENA high-altitude cusp signal for the southward IMF. C1 Univ Electrocommun, Sugadaira Space Radio Observatory, Tokyo, Japan. Univ Electrocommun, Dept Informat & Commun Engn, Tokyo, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. Natl Inst Polar Res, Tokyo, Japan. RP Murata, Y (reprint author), Univ Electrocommun, Sugadaira Space Radio Observatory, Tokyo, Japan. EM ymurata@ice.uec.ac.jp; taguchi@ice.uec.ac.jp RI Moore, Thomas/D-4675-2012; Collier, Michael/I-4864-2013 OI Moore, Thomas/0000-0002-3150-1137; Collier, Michael/0000-0001-9658-6605 NR 50 TC 4 Z9 4 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 13 PY 2007 VL 112 IS A11 AR A11208 DI 10.1029/2007JA012404 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 233AM UT WOS:000251062800003 ER PT J AU Kinney, AL AF Kinney, A. L. TI National scientific facilities and their science impact on nonbiomedical research SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE federally funded facilities; physical sciences; science metrics AB The "h index" proposed by Hirsch [Hirsch JE (2005) Proc Natl Acad Sci USA 102:16569-16573] is a good indicator of the impact of a scientist's research and has the advantage of being objective. When evaluating departments, institutions, or laboratories, the importance of the h index can be further enhanced when it is properly calibrated for the size of the group. Particularly acute is the issue of federally funded facilities whose number of actively publishing scientists frequently dwarfs that of academic departments. Recently, Molinari and Molinari [Molinari JF, Molinari A (2008) Scientometrics, in press] developed a methodology that shows that the h index has a universal growth rate for large numbers of papers, allowing for meaningful comparisons between institutions. An additional challenge when comparing large institutions is that fields have distinct internal cultures, with different typical rates of publication and citation; biology is more highly cited than physics, for example. For this reason, the present study has focused on the physical sciences, engineering, and technology and has excluded biomedical research. Comparisons between individual disciplines are reported here to provide a framework. Generally, it was found that the universal growth rate of Molinari and Molinari holds well across the categories considered, testifying to the robustness of both their growth law and our results. The goal here is to set the highest standard of comparison for federal investment in science. Comparisons are made of the nation's preeminent private and public institutions. We find that many among the national science facilities compare favorably in research impact with the nation's leading universities. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kinney, AL (reprint author), NASA, Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. EM anne.l.kinney@nasa.gov NR 2 TC 41 Z9 42 U1 1 U2 13 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 13 PY 2007 VL 104 IS 46 BP 17943 EP 17947 DI 10.1073/pnas.0704416104 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 233FY UT WOS:000251077000011 PM 17991781 ER PT J AU Schurch, MPE Coe, MJ McGowan, KE McBride, VA Buckley, DAH Galache, JL Corbet, RHD Still, M Vaisanen, P Kniazev, A Nordsieck, K AF Schurch, M. P. E. Coe, M. J. McGowan, K. E. McBride, V. A. Buckley, D. A. H. Galache, J. L. Corbet, R. H. D. Still, M. Vaisanen, P. Kniazev, A. Nordsieck, K. TI Optical follow-up of new small magellanic cloud wing Be/X-ray binaries SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars; emission-line; Be; Magellanic Clouds; X-rays; binaries ID STARS; CATALOG; DISC; SMC; OB AB We investigate the optical counterparts of recently discovered Be/X-ray binaries in the Small Magellanic Cloud (SMC). In total four sources, SXP101, SXP700, SXP348 and SXP65.8 were detected during the Chandra survey of the wing of the SMC. SXP700 and SXP65.8 were previously unknown. Many optical ground-based telescopes have been utilized in the optical follow-up, providing coverage in both the red and blue bands. This has led to the classification of all of the counterparts as Be stars and confirms that three lie within the Galactic spectral distribution of known Be/X-ray binaries. SXP101 lies outside this distribution and is the latest spectral type known. Monitoring of the H alpha emission line suggests that all the sources barring SXP700 have highly variable circumstellar discs, possibly a result of their comparatively short orbital periods. Phase-resolved X-ray spectroscopy has also been performed on SXP65.8, revealing that the emission is indeed harder during the passage of the X-ray beam through the line of sight. C1 Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. S African Astron Observ, ZA-7935 Cape Town, South Africa. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RP Schurch, MPE (reprint author), Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. EM mpes@astro.soton.ac.uk NR 26 TC 9 Z9 9 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD NOV 11 PY 2007 VL 381 IS 4 BP 1561 EP 1568 DI 10.1111/j.1365-2966.2007.12315.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 227HO UT WOS:000250648000021 ER PT J AU Georgiev, GT Butler, JJ AF Georgiev, Georgi T. Butler, James J. TI Long-term calibration monitoring of Spectralon diffusers BRDF in the air-ultraviolet SO APPLIED OPTICS LA English DT Article AB Long-term calibration monitoring of the bidirectional reflectance distribution function (BRDF) of Spectralon diffusers in the air-ultraviolet is presented. Four Spectralon diffusers were monitored in this study. Three of the diffusers, designated as H1, H2, and H3, were used in the prelaunch radiance calibration of the Solar Backscatter Ultraviolet/2 (SBUV/2) satellite instruments on National Oceanic and Atmospheric Administration (NOAA) 14 and 16. A fourth diffuser, designated as the 400 diffuser, was used in the prelaunch calibration of the Ozone Mapping and Profiler Suite (OMPS) instrument scheduled for initial flight in 2009 on the National Polar Orbiting Environmental Satellite System Preparatory Project. The BRDF data of this study were obtained between 1994 and 2005 using the scatterometer located in the National Aeronautics and Space Administration Goddard Space Flight Center Diffuser Calibration Laboratory. The diffusers were measured at 13 wavelengths between 230 and 425 nm at the incident and scatter angles used in the prelaunch calibrations of SBUV/2 and OMPS. Spectral features in the BRDF of Spectralon are also discussed. The comparison shows how the air-ultraviolet BRDF of these Spectralon samples changed over time under clean room deployment conditions. (C) 2007 Optical Society of America. C1 [Georgiev, Georgi T.] Sci Syst & Applicat Inc, Lanham, MD 20706 USA. [Butler, James J.] NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Georgiev, GT (reprint author), Sci Syst & Applicat Inc, Lanham, MD 20706 USA. EM ggeorgi@pop900.gsfc.nasa.gov RI Butler, James/D-4188-2013 NR 14 TC 25 Z9 26 U1 0 U2 2 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 NOV 10 PY 2007 VL 46 IS 32 BP 7892 EP 7899 DI 10.1364/AO.46.007892 PG 8 WC Optics SC Optics GA 242PZ UT WOS:000251739200016 PM 17994141 ER PT J AU Zhai, CX Milman, MH Regehr, MW Best, PK AF Zhai, Chengxing Milman, Mark H. Regehr, Martin W. Best, Paul K. TI White-light interferometry using a channeled spectrum. 2. Calibration methods, numerical and experimental results SO APPLIED OPTICS LA English DT Article ID PHASE CORRECTION; MISSION; SIM AB In the companion paper, [Appl. Opt. 46,5853 (2007)] a highly accurate white light interference model was developed from just a few key parameters characterized in terms of various moments of the source and instrument transmission function. We develop and implement the end-to-end process of calibrating these moment parameters together with the differential dispersion of the instrument and applying them to the algorithms developed in the companion paper. The calibration procedure developed herein is based on first obtaining the standard monochromatic parameters at the pixel level: wavenumber, phase, intensity, and visibility parameters via a nonlinear least-squares procedure that exploits the structure of the model. The pixel level parameters are then combined to obtain the required "global" moment and dispersion parameters. The process is applied to both simulated scenarios of astrometric observations and to data from the microarcsecond metrology testbed (MAM), an interferometer testbed that has played a prominent role in the development of this technology. (C) 2007 Optical Society of America. C1 [Zhai, Chengxing; Milman, Mark H.; Regehr, Martin W.; Best, Paul K.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Zhai, CX (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Chengxing.Zhai@jpl.nasa.gov NR 18 TC 3 Z9 3 U1 0 U2 0 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 NOV 10 PY 2007 VL 46 IS 32 BP 7906 EP 7923 DI 10.1364/AO.46.007906 PG 18 WC Optics SC Optics GA 242PZ UT WOS:000251739200018 PM 17994143 ER PT J AU Ksendzov, A Lay, O Martin, S Sanghera, JS Busse, LE Kim, WH Pureza, PC Nguyen, VQ Aggarwal, ID AF Ksendzov, A. Lay, O. Martin, S. Sanghera, J. S. Busse, L. E. Kim, W. H. Pureza, P. C. Nguyen, V. Q. Aggarwal, I. D. TI Characterization of mid-infrared single mode fibers as modal filters SO APPLIED OPTICS LA English DT Article ID PLANETS AB We present a technique for measuring the modal filtering ability of single mode fibers. The ideal modal filter rejects all input field components that have no overlap with the fundamental mode of the filter and does not attenuate the fundamental mode. We define the quality of a nonideal modal filter Q(f) as the ratio of transmittance for the fundamental mode to the transmittance for an input field that has no overlap with the fundamental mode. We demonstrate the technique on a 20 cm long mid-infrared fiber that was produced by the U.S. Naval Research Laboratory. The filter quality Q(f) for this fiber at 10.5 mu m wavelength is 1000 +/- 300. The absorption and scattering losses in the fundamental mode are approximately 8 dB/m. The total transmittance for the fundamental mode, including Fresnel reflections, is 0.428 +/- 0.002. The application of interest is the search for extrasolar Earthlike planets using nulling interferometry. It requires high rejection ratios to suppress the light of a bright star, so that the faint planet becomes visible. The use of modal filters increases the rejection ratio (or, equivalently, relaxes requirements on the wavefront quality) by reducing the sensitivity to small wavefront errors. We show theoretically that, exclusive of coupling losses, the use of a modal filter leads to the improvement of the rejection ratio in a two-beam interferometer by a factor of Q(f). (C) 2007 Optical Society of America. C1 [Ksendzov, A.; Lay, O.; Martin, S.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Sanghera, J. S.; Busse, L. E.; Kim, W. H.; Pureza, P. C.; Nguyen, V. Q.; Aggarwal, I. D.] USN, Res Lab, Washington, DC 20375 USA. RP Ksendzov, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM alexander.ksendzov@jpl.nasa.gov NR 10 TC 28 Z9 28 U1 0 U2 4 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 NOV 10 PY 2007 VL 46 IS 32 BP 7957 EP 7962 DI 10.1364/AO.46.007957 PG 6 WC Optics SC Optics GA 242PZ UT WOS:000251739200022 PM 17994147 ER PT J AU Sambruna, RM Tavecchio, F Ghisellini, G Donato, D Holland, ST Markwardt, CB Tueller, J Mushotzky, RF AF Sambruna, R. M. Tavecchio, F. Ghisellini, G. Donato, D. Holland, S. T. Markwardt, C. B. Tueller, J. Mushotzky, R. F. TI Swift observations of high-redshift radio-loud quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : jets; quasars : general; X-rays : galaxies ID X-RAY-SPECTRA; ACTIVE GALACTIC NUCLEI; BURST ALERT TELESCOPE; JET-DISK CONNECTION; BL LACERTAE OBJECTS; BLAZARS; EMISSION; COMPTONIZATION; RADIATION; GALAXIES AB We report on Swift observations of four z > 2 radio-loud quasars (0212+735, 0537-286, 0836+710, and 2149-307), classified as blazars. The sources, well-known emitters at soft-to-medium X-rays, were detected at > 5 sigma with the BAT experiment in 15-150 keV. No flux variability was detected within the XRT and BAT exposures, with the exception of 0836+710, which shows an increase by a factor of 4 in the 15-150 keV flux on a timescale of 1 month. The 0.3-10 keV spectra are well fitted by power-law models, with rather hard continua ( photon indices Gamma(XRT) similar to 1.3-1.5); similarly, the 15-150 keV spectra are described by power laws with Gamma(BAT) similar to 1.3-1.8. The XRT data exhibit spectral curvature, which can be modeled in terms of either excess absorption along the line of sight or a downward-curved broken power law. In the former case, if the excess NH is at the rest frame of the source, columns of N-H(z) (0.3-6)X10(22) cm(-2) are measured. Modeling of the SEDs of the four quasars shows that the emission at the higher frequencies, greater than or similar to 10(16) Hz, is dominated by the jet, while the steep optical-to-UV continua, observed with the UVOT, can be attributed to thermal emission from the accretion disk. The disk luminosity is between 1% and 10% of the jet power, similar to other powerful blazars. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Osserv Astron Brera, I-20121 Milan, Italy. RP Sambruna, RM (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Tueller, Jack/D-5334-2012; OI Ghisellini, Gabriele/0000-0002-0037-1974 NR 41 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 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 2007 VL 669 IS 2 BP 884 EP 892 DI 10.1086/521694 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500018 ER PT J AU Becker, MR McKay, TA Koester, B Wechsler, RH Rozo, E Evrard, A Johnston, D Sheldon, E Annis, J Lau, E Nichol, R Miller, C AF Becker, M. R. McKay, T. A. Koester, B. Wechsler, R. H. Rozo, E. Evrard, A. Johnston, D. Sheldon, E. Annis, J. Lau, E. Nichol, R. Miller, C. TI The mean and scatter of the velocity dispersion-optical richness relation for maxBCG galaxy clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : clusters : general; methods : data analysis ID DIGITAL SKY SURVEY; SPECTROSCOPIC TARGET SELECTION; DARK-MATTER HALOES; LUMINOSITY FUNCTION; REDSHIFT SURVEY; MASS FUNCTION; COSMOLOGICAL CONSTRAINTS; PECULIAR VELOCITIES; ELLIPTIC GALAXIES; DENSITY PROFILE AB The distribution of galaxies in position and velocity around the centers of galaxy clusters encodes important information about cluster mass and structure. Using the maxBCG galaxy cluster catalog identified from imaging data obtained in the Sloan Digital Sky Survey, we study the BCG-galaxy velocity correlation function. By modeling its non-Gaussianity, we measure the mean and scatter in velocity dispersion at fixed richness. The mean velocity dispersion increases from 202 +/- 10 km s(-1) for small groups to more than 854 +/- 102 km s(-1) for large clusters. We show the scatter to be at most 40.5% +/- 3.5%, declining to 14.9% +/- 9.4% in the richest bins. We test our methods in the C4 cluster catalog, a spectroscopic cluster catalog produced from the Sloan Digital Sky Survey DR2 spectroscopic sample, and in mock galaxy catalogs constructed from N-body simulations. Our methods are robust, measuring the scatter to well within 1 sigma of the true value, and the mean to within 10%, in the mock catalogs. By convolving the scatter in velocity dispersion at fixed richness with the observed richness space density function, we measure the velocity dispersion function of the maxBCG galaxy clusters. Although velocity dispersion and richness do not form a true mass- observable relation, the relationship between velocity dispersion and mass is theoretically well characterized and has low scatter. Thus, our results provide a key link between theory and observations up to the velocity bias between dark matter and galaxies. C1 Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. Ohio State Univ, CCAPP, Columbus, OH 43210 USA. Univ Michigan, Michigan Ctr Theoret Phys, Ann Arbor, MI 48109 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NYU, Dept Phys, New York, NY 10003 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Portsmouth, Portsmouth, Hants, England. RP Becker, MR (reprint author), Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. RI McKay, Timothy/C-1501-2009; OI McKay, Timothy/0000-0001-9036-6150; Evrard, August/0000-0002-4876-956X; Becker, Matthew/0000-0001-7774-2246 NR 98 TC 82 Z9 82 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 10 PY 2007 VL 669 IS 2 BP 905 EP 928 DI 10.1086/521920 PN 1 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500020 ER PT J AU Roussel, H Helou, G Hollenbach, DJ Draine, BT Smith, JD Armus, L Schinnerer, E Walter, F Engelbracht, CW Thornley, MD Kennicutt, RC Calzetti, D Dale, DA Murphy, EJ Bot, C AF Roussel, H. Helou, G. Hollenbach, D. J. Draine, B. T. Smith, J. D. Armus, L. Schinnerer, E. Walter, F. Engelbracht, C. W. Thornley, M. D. Kennicutt, R. C. Calzetti, D. Dale, D. A. Murphy, E. J. Bot, C. TI Warm molecular hydrogen in the Spitzer SINGS galaxy sample SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : ISM; infrared : galaxies; infrared : ISM; ISM : lines and bands; ISM : molecules; surveys ID NEARBY SPIRAL-GALAXIES; POLYCYCLIC AROMATIC-HYDROCARBONS; MAGNETOHYDRODYNAMIC SHOCK-WAVES; ULTRALUMINOUS INFRARED GALAXIES; DIFFUSE INTERSTELLAR-MEDIUM; PURE ROTATIONAL LINES; RESOLUTION CO SURVEY; NGC-1316 FORNAX-A; X-RAY SOURCES; STAR-FORMATION AB Results on the properties of warm molecular hydrogen in 57 normal galaxies are derived from measurements of H-2 rotational transitions, obtained as part of SINGS. This study extends previous extragalactic surveys of emission lines of H-2 to fainter and more common systems (L-FIR = 10(7)-6 X 10(10) L-circle dot). The 17 mu m S(1) transition is securely detected in the nuclear regions of 86% of galaxies with stellar masses above 10(9.5) M-circle dot. The derived column densities of warm H-2 (T >= 100 K), although averaged over kiloparsec-scale areas, are commensurate with values observed in resolved photodissociation regions. They amount to between 1% and > 30% of the total H-2. The power emitted in the three lowest energy transitions is on average 30% of the power of the bright [Si II] cooling line (34.8 mu m) and about 4 X 10(-4) of the total infrared power for star-forming galaxies, which is consistent with excitation in PDRs. The fact that the H2 line intensities scale tightly with the aromatic band emission, even though the average radiation field intensity varies by a factor of 10, can also be understood if both tracers originate predominantly in PDRs, either dense or diffuse. Many of the 25 LINER/Seyfert targets strongly depart from the rest of the sample, in having warmer excited H-2 and excess H-2 rotational power with respect to the dust emission. We propose a threshold in H-2-to-aromatic band power ratios, allowing the identification of low-luminosity AGNs by an excess H-2 excitation. A dominant contribution from shock heating is favored in these objects. Finally, we detect in nearly half the star-forming targets nonequilibrium orthotopara ratios, consistent with the effects of FUV pumping combined with incomplete ortho-para thermalization, or possibly nonequilibrium photodissociation fronts. C1 Max Planck Inst Astron, D-69117 Heidelberg, Germany. CALTECH, Pasadena, CA 91125 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Bucknell Univ, Lewisburg, PA 17837 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Massachusetts, Amherst, MA 01003 USA. Univ Wyoming, Laramie, WY 82071 USA. Yale Univ, New Haven, CT 06520 USA. RP Roussel, H (reprint author), Max Planck Inst Astron, D-69117 Heidelberg, Germany. EM roussel@mpia-hd.mpg.de OI Draine, Bruce/0000-0002-0846-936X NR 155 TC 91 Z9 91 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 10 PY 2007 VL 669 IS 2 BP 959 EP 981 DI 10.1086/521667 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500024 ER PT J AU Rol, E Van der Horst, A Wiersema, K Patel, SK Levan, A Nysewander, M Kouveliotou, C Wijers, RAMJ Tanvir, N Reichart, D Fruchter, AS Graham, J Ovaldsen, JE Jaunsen, AO Jonker, P Van Ham, W Hjorth, J Starling, RLC O'Brien, PT Fynbo, J Burrows, DN Strom, R AF Rol, Evert Van der Horst, Alexander Wiersema, Klaas Patel, Sandeep K. Levan, Andrew Nysewander, Melissa Kouveliotou, Chryssa Wijers, Ralph A. M. J. Tanvir, Nial Reichart, Dan Fruchter, Andrew S. Graham, John Ovaldsen, Jan-Erik Jaunsen, Andreas O. Jonker, Peter Van Ham, Wilbert Hjorth, Jens Starling, Rhaana L. C. O'Brien, Paul T. Fynbo, Johan Burrows, David N. Strom, Richard TI Grb 051022: Physical parameters and extinction of a prototype dark burst SO ASTROPHYSICAL JOURNAL LA English DT Article ID GAMMA-RAY BURSTS; HOST-GALAXY; PHOTOMETRIC REDSHIFT; MAGELLANIC CLOUD; SKY SURVEY; DUST; AFTERGLOWS; ENVIRONMENTS; DESTRUCTION; ABSORPTION AB GRB 051022 was undetected to deep limits in early optical observations, but precise astrometry from radio and X-rays showed that it most likely originated in a galaxy at z approximate to 0.8. We report radio, optical, near-infrared, and X-ray observations of GRB 051022. Using the available X-ray and radio data, we model the afterglow and calculate its energetics, finding it to be an order of magnitude lower than that of the prompt emission. The broadband modeling also allows us to precisely define various other physical parameters and the minimum required amount of extinction to explain the absence of an optical afterglow. Our observations suggest a high extinction, at least 2.3 mag in the infrared (J) and at least 5.4 mag in the optical (U) in the host-galaxy rest frame. Such high extinctions are unusual for GRBs and likely indicate a geometry where our line of sight to the burst passes through a dusty region in the host that is not directly colocated with the burst itself. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Univ Amsterdam, Astron Inst, NL-1098 SJ Amsterdam, Netherlands. Natl Space Sci & Technol, Huntsville, AL 35805 USA. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Opt Sci Corp, Huntsville, AL 35806 USA. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. SRON, Netherlands Inst Space Res, NL-3584 CA Utrecht, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Utrecht, Astron Inst, NL-3508 TA Utrecht, Netherlands. Radboud Univ Nijmegen, Dept Astrophys, NL-6500 GL Nijmegen, Netherlands. Univ Copenhagen, Niels Bohr Inst, Dark Cosmol Ctr, DK-2100 Copenhagen, Denmark. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16801 USA. ASTRON, NL-7990 AA Dwingeloo, Netherlands. RP Rol, E (reprint author), Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England. EM evert.rol@star.le.ac.uk RI Hjorth, Jens/M-5787-2014; OI Hjorth, Jens/0000-0002-4571-2306; Wijers, Ralph/0000-0002-3101-1808 NR 84 TC 46 Z9 47 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 10 PY 2007 VL 669 IS 2 BP 1098 EP 1106 DI 10.1086/521336 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500035 ER PT J AU Yost, SA Aharonian, F Akerlof, CW Ashley, MCB Barthelmy, S Gehrels, N Gogues, E Guver, T Horns, D Kiziloglu, U Krimm, HA Mckay, TA Ozel, M Phillips, A Quimby, RM Rowell, G Rujopakarn, W Rykoff, ES Schaefer, BE Smith, DA Swan, HF Vestrand, WT Wheeler, JC Wren, J Yuan, F AF Yost, S. A. Aharonian, F. Akerlof, C. W. Ashley, M. C. B. Barthelmy, S. Gehrels, N. Goegues, E. Guever, T. Horns, D. Kiziloglu, Ue. Krimm, H. A. Mckay, T. A. Oezel, M. Phillips, A. Quimby, R. M. Rowell, G. Rujopakarn, W. Rykoff, E. S. Schaefer, B. E. Smith, D. A. Swan, H. F. Vestrand, W. T. Wheeler, J. C. Wren, J. Yuan, F. TI The dark side of ROTSE-III prompt GRB observations SO ASTROPHYSICAL JOURNAL LA English DT Article ID GAMMA-RAY-BURSTS; EARLY OPTICAL AFTERGLOW; SPECTRAL EVOLUTION; EMISSION; PHOTOMETRY; RADIATION; FLASHES; SYSTEM; WAVE AB We present several cases of optical observations during gamma-ray bursts (GRBs) which resulted in prompt limits but no detection of optical emission. These limits constrain the prompt optical flux densities and the optical brightness relative to the gamma-ray emission. The derived constraints fall within the range of properties observed in GRBs with prompt optical detections, although at the faint end of optical/gamma-ray flux ratios. The currently accessible prompt optical limits do not require a different set of intrinsic or environmental GRB properties, relative to the events with prompt optical detections. C1 Univ Michigan, Randall Lab 2477, Ann Arbor, MI 48104 USA. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. Univ New S Wales, Dept Astrophys & Opt, Sch Phys, Sydney, NSW 2052, Australia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sabanci Univ, TR-34956 Istanbul, Turkey. Univ Istanbul, Dept Astron & Space Sci, Fac Sci, TR-34119 Istanbul, Turkey. Middle E Tech Univ, TR-06531 Ankara, Turkey. Univ Space Res Assoc, Columbia, MD 21044 USA. Canakkale Onseliz Mart Univ, TR-17020 Terzioglu, Canakkale, Turkey. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Adelaide, Sch Chem & Phys, Adelaide, SA 5005, Australia. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Guilford Coll, Greensboro, NC 27410 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Yost, SA (reprint author), Univ Michigan, Randall Lab 2477, 450 Church St, Ann Arbor, MI 48104 USA. EM sayost@umich.edu; Felix.Aharonian@mpi-hd.mpg.de; jwren@nis.lanl.gov; mcba@phys.unsw.edu.au; scott@lheamail.gsfc.nasa.gov; gehrels@gsfc.nasa.gov; ersing@sabanciuniv.edu; tolga@istanbul.edu.tr; horns@mpi-hd.mpg.de; umk@astroa.physics.metu.edu.tr; krimm@milkyway.gsfc.nasa.gov; tamckay@umich.edu; erykoff@umich.edu; a.phillips@unsw.edu.au; quimby@astro.as.utexas.edu; vestrand@lanl.gov; dsmith4@guilford.edu; erykoff@umich.edu; schaefer@lsu.edu; dsmith4@guilford.edu; hswan@umich.edu; vestrand@lanl.gov; wiphu@as.arizona.edu; jwren@nis.lanl.gov; yuanfang@umich.edu RI Guver, Tolga/C-1408-2011; Horns, Dieter/C-9727-2011; Barthelmy, Scott/D-2943-2012; Gehrels, Neil/D-2971-2012; Rujopakarn, Wiphu/E-7849-2012; McKay, Timothy/C-1501-2009; Guver, Tolga/B-1039-2014; OI McKay, Timothy/0000-0001-9036-6150; Guver, Tolga/0000-0002-3531-9842; Rujopakarn, Wiphu/0000-0002-0303-499X; Flewelling, Heather/0000-0002-1050-4056; Rowell, Gavin/0000-0002-9516-1581 NR 44 TC 28 Z9 28 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 10 PY 2007 VL 669 IS 2 BP 1107 EP 1114 DI 10.1086/521668 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500036 ER PT J AU Sakamoto, T Hill, JE Yamazaki, R Angelini, L Krimm, HA Sato, G Swindell, S Takami, K Osborne, JP AF Sakamoto, T. Hill, J. E. Yamazaki, R. Angelini, L. Krimm, H. A. Sato, G. Swindell, S. Takami, K. Osborne, J. P. TI Evidence of exponential decay emission in the swift gamma-ray bursts SO ASTROPHYSICAL JOURNAL LA English DT Article ID AFTERGLOW LIGHT CURVES; FIREBALL MODEL; JET MODELS; XRT DATA; FLASHES; PROMPT; LONG; BATSE; TELESCOPE; SPECTRA AB We present a systematic study of the steep decay emission from gamma-ray bursts (GRBs) observed by the Swift X-Ray Telescope (XRT). In contrast to the analysis described in recent literature, we produce composite Burst Alert Telescope (BAT) and XRT light curves by extrapolating the XRT data (2-10 keV) into the BAT energy range (15-25 keV) rather than extrapolating the BAT data into the XRT energy band (0.3-10 keV). Based on the fits to the composite light curves, we have confirmed the existence of an exponential decay component which smoothly connects the BAT prompt data to the XRT steep decay for several GRBs. We also find that the XRT steep decay for some of the bursts can be well fit by a combination of a power law with an exponential decay model. We discuss this exponential component within the framework of both the internal and the external shock model. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Oak Ridge Associated Univ, Oak Ridge, TN 37831 USA. NASA, Goddard Space Flight Ctr, CRESST, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. Hiroshima Univ, Dept Phys, Hiroshima 7398526, Japan. JAXA, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. N Carolina Agr & Tech State Univ, Dept Phys, Greensboro, NC 27411 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. RP Sakamoto, T (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 59 TC 26 Z9 26 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 10 PY 2007 VL 669 IS 2 BP 1115 EP 1129 DI 10.1086/521640 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500037 ER PT J AU Smith, DM Dawson, DM Swank, JH AF Smith, D. M. Dawson, D. M. Swank, J. H. TI Hysteresis of spectral evolution in the soft state of black hole binary LMC X-3 SO ASTROPHYSICAL JOURNAL LA English DT Article ID X-RAY BINARIES; GRS 1758-258; HARD STATE; INFRARED COUNTERPART; ACCRETION DISKS; TRANSITIONS; LONG; CANDIDATES; FLOWS; GRS-1758-258 AB We report the discovery of hysteresis between the X-ray spectrum and luminosity of black hole binary LMC X-3. Our observations, made with the Proportional Counter Array on the Rossi X-Ray Timing Explorer, took place entirely within the soft spectral state, which was dominated by a spectral component that was fitted well with a multicolor disk blackbody. A power-law component was seen only during times when the luminosity of the disk blackbody was declining. The X-ray luminosity at these times was comparable to that seen in transient systems (X-ray novae) when they return to the hard state at the end of an outburst. Our observations may represent partial transitions to the hard state; complete transitions have been seen in this system by Wilms and coworkers. If they are related to the soft-to-hard transition in transients, then they demonstrate that hysteresis effects can appear without a full state transition. We discuss these observations in the context of earlier observations of hysteresis within the hard state of binaries 1E 1740.7-2942 and GRS 1758-258 and in relation to published explanations of hysteresis in transients. C1 Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Smith, DM (reprint author), Univ Calif Santa Cruz, Dept Phys, 1156 High St, Santa Cruz, CA 95064 USA. RI Swank, Jean/F-2693-2012 NR 34 TC 24 Z9 25 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 10 PY 2007 VL 669 IS 2 BP 1138 EP 1142 DI 10.1086/521822 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500039 ER PT J AU Lane, BF Muterspaugh, MW Fekel, FC Williamson, M Browne, S Konacki, M Burke, BF Colavita, MM Kulkarni, SR Shao, M AF Lane, Benjamin F. Muterspaugh, Matthew W. Fekel, Francis C. Williamson, Michael Browne, Stanley Konacki, Maciej Burke, Bernard F. Colavita, M. M. Kulkarni, S. R. Shao, M. TI The orbits of the quadruple star system 88 Tauri a from PHASES differential astrometry and radial velocity SO ASTROPHYSICAL JOURNAL LA English DT Article ID PALOMAR TESTBED INTERFEROMETER; A-TYPE STARS; BINARY STARS; ROTATIONAL VELOCITIES; SPECTRAL CLASSIFICATION; SPECKLE INTERFEROMETRY; MULTIPLE SYSTEMS; TRIPLE STARS; TELESCOPE; CATALOG AB We have used high-precision differential astrometry from the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) project and radial velocity measurements covering a time span of 20 years to determine the orbital parameters of the 88 Tau A system. 88 Tau is a complex hierarchical multiple system comprising a total of six stars; we have studied the brightest four, consisting of two short-period pairs orbiting each other with an similar to 18 yr period. We present the first orbital solution for one of the short-period pairs, and determine the masses of the components and distance to the system to the level of a few percent. In addition, our astrometric measurements allow us to make the first determination of the mutual inclinations of the orbits. We find that the subsystems are not coplanar. C1 MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Tennessee State Univ, Ctr Excellence Informat Syst, Nashville, TN 37209 USA. Polish Acad Sci, Nicholas Copernicus Astron Ctr, PL-87100 Torun, Poland. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. RP Lane, BF (reprint author), MIT, Kavli Inst Astrophys & Space Res, 70 Vassar St, Cambridge, MA 02139 USA. NR 42 TC 14 Z9 14 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 NOV 10 PY 2007 VL 669 IS 2 BP 1209 EP 1219 DI 10.1086/520877 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500045 ER PT J AU Seager, S Kuchner, M Hier-Majumder, CA Militzer, B AF Seager, S. Kuchner, M. Hier-Majumder, C. A. Militzer, B. TI Mass-radius relationships for solid exoplanets SO ASTROPHYSICAL JOURNAL LA English DT Article ID EXTRA-SOLAR PLANETS; M-CIRCLE-PLUS; THERMAL EXPANSIVITY; HIGH-PRESSURE; EARTH-MASSES; HARPS SEARCH; TRANSITING PLANET; MELTING CURVE; GIANT PLANETS; BULK MODULUS AB We use new interior models of cold planets to investigate the mass-radius relationships of solid exoplanets, considering planets made primarily of iron, silicates, water, and carbon compounds. We find that the mass-radius relationships for cold terrestrial mass planets of all compositions we considered follow a generic functional form that is not a simple power law: log(10)R(s) = k(1) + 1/3log(10)(M-s) - k(2)M(s)(k3) for up to M-p approximate to 20 M-circle plus, where M-s and R-s are scaled mass and radius values. This functional form arises because the common building blocks of solid planets all have equations of state that are well approximated by a modified polytrope of the form rho = rho(0) + cP(n). We find that highly detailed planet interior models, including temperature structure and phase changes, are not necessary to derive solid exoplanet bulk composition from mass and radius measurements. For solid exoplanets with no substantial atmosphere we have also found the following: with similar to 5% fractional uncertainty in planet mass and radius it is possible to distinguish among planets composed predominantly of iron or silicates or water ice but not more detailed compositions; with similar to 5% uncertainty water ice planets with greater than or similar to 25% water by mass may be identified; the minimum plausible planet size for a given mass is that of a pure iron planet; and carbon planet mass-radius relationships overlap with those of silicate and water planets due to similar zero-pressure densities and equations of state. We propose a definition of "super-Earths'' based on the clear distinction in radii between planets with significant gas envelopes and those without. C1 Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. MIT, Dept Phys, Dept Earth Atmospher & Planetary Sci, Concord, MA 01742 USA. NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. RP Seager, S (reprint author), Carnegie Inst Washington, Dept Terr Magnetism, 5241 Broad Branch Rd NW, Washington, DC 20015 USA. RI Kuchner, Marc/E-2288-2012 NR 74 TC 250 Z9 251 U1 2 U2 31 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 10 PY 2007 VL 669 IS 2 BP 1279 EP 1297 DI 10.1086/521346 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500050 ER PT J AU Niedzielski, A Konacki, M Wolszczan, A Nowak, G Maciejewski, G Gelino, CR Shao, M Shetrone, M Ramsey, LW AF Niedzielski, A. Konacki, M. Wolszczan, A. Nowak, G. Maciejewski, G. Gelino, C. R. Shao, M. Shetrone, M. Ramsey, L. W. TI A planetary-mass companion to the K0 giant HD 17092 SO ASTROPHYSICAL JOURNAL LA English DT Article DE planetary systems; stars : individual (HD 17092) ID RADIAL-VELOCITY VARIATIONS; HOBBY-EBERLY TELESCOPE; SPECTRAL-LINE BISECTORS; 51 PEGASI; SUBSTELLAR COMPANION; EVOLUTIONARY TRACKS; COOL STARS; VARIABILITY; HYPOTHESIS; EXOPLANETS AB We report the discovery of a substellar-mass companion to the K0 giant HD 17092 with the Hobby-Eberly Telescope. In the absence of any correlation of the observed 360 day periodicity with the standard indicators of stellar activity, the observed radial velocity variations are most plausibly explained in terms of a Keplerian motion of a planetary-mass body around the star. As the estimated stellar mass is 2.3 M-circle dot, the minimum mass of the planet is 4.6 M-J. The planet's orbit is characterized by a mild eccentricity of e 0: 17 and a semimajor axis of 1.3 AU. This is the tenth published detection of a planetary companion around a red giant star. Such discoveries add to our understanding of planet formation around intermediate-mass stars, and they provide dynamical information on the evolution of planetary systems around post-main-sequence stars. C1 Nicholas Copernicus Univ, Torun Ctr Astron, PL-87100 Torun, Poland. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Nicholas Copernicus Astron Ctr, PL-87100 Torun, Poland. CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Texas, McDonald Observ, Fort Davis, TX 79734 USA. RP Niedzielski, A (reprint author), Nicholas Copernicus Univ, Torun Ctr Astron, Gagarina 11, PL-87100 Torun, Poland. RI Maciejewski, Gracjan/D-6241-2014; Nowak, Grzegorz/H-8234-2014 OI Nowak, Grzegorz/0000-0002-7031-7754 NR 61 TC 67 Z9 67 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 10 PY 2007 VL 669 IS 2 BP 1354 EP 1358 DI 10.1086/521784 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500056 ER PT J AU Sterling, AC Harra, LK Moore, RL AF Sterling, Alphonse C. Harra, Louise K. Moore, Ronald L. TI New evidence for the role of emerging flux in a solar filament's slow rise preceding its CME-producing fast eruption SO ASTROPHYSICAL JOURNAL LA English DT Article DE sun : coronal mass ejections (CMEs); sun : filaments; sun : flares; sun : UV radiation; sun : x-rays; gamma rays ID CORONAL MASS EJECTIONS; MAGNETIC-FIELDS; EXTERNAL RECONNECTION; FLARES; PROMINENCE; SOHO; MULTIWAVELENGTH; TELESCOPE; EMERGENCE; MECHANISM AB We observe the eruption of a large-scale ( approximate to 300,000 km) quiet-region solar filament leading to an Earth-directed "halo'' coronal mass ejection (CME), using data from EIT, CDS, MDI, and LASCO on SOHO and from SXT on Yohkoh. Initially the filament shows a slow ( similar to 1 km s(-1) projected against the solar disk) and approximately constant velocity rise for about 6 hr, before erupting rapidly, reaching a velocity of similar to 8 km s(-1) over the next approximate to 25 minutes. CDS Doppler data show Earth-directed filament velocities ranging from < 20 km s(-1) ( the noise limit) during the slow-rise phase, to similar to 100 km s(-1) early in the eruption. Beginning within 10 hr prior to the start of the slow rise, localized new magnetic flux emerged near one end of the filament. Near the start of and during the slow-rise phase, soft X-ray (SXR) microflaring occurred repeatedly at the flux-emergence site, and the magnetic arcade over the filament progressively brightened in a fan of illumination in SXRs. These observations are consistent with "tether-weakening'' reconnection occurring between the newly emerging flux and the overlying arcade field containing the filament, and apparently this reconnection is the cause of the filament's slow rise. We cannot, however, discern whether the transition from slow rise to fast eruption was caused by a final episode of tether-weakening reconnection, or by one or some combination of other possible mechanisms allowed by the observations. Intensity "dimmings'' and "brightenings'' occurring both near to and relatively far from the location of the filament are possible signatures of the expansion ("opening'') of the erupting field and its reconnection with overarching field during the eruption. C1 NASA, Marshal Space Flight Ctr, Space Sci Off, Huntsville, AL 35805 USA. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. RP Sterling, AC (reprint author), JAXA, Inst Space & Astronaut Sci, Hinode Grp, 3-1-1 Yoshinodai, Kanagawa 2298510, Japan. EM alphonse.sterling@nasa.gov; lkh@mssl.ucl.ac.uk; ron.moore@nasa.gov OI Harra, Louise/0000-0001-9457-6200 NR 55 TC 39 Z9 39 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 10 PY 2007 VL 669 IS 2 BP 1359 EP 1371 DI 10.1086/520829 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228VK UT WOS:000250760500057 ER PT J AU Han, SC Ray, RD Luthcke, SB AF Han, Shin-Chan Ray, Richard D. Luthcke, Scott B. TI Ocean tidal solutions in Antarctica from GRACE inter-satellite tracking data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MODELS; TIDES AB Long-wavelength components of the oceanic tides surrounding Antarctica are estimated directly from three years of GRACE satellite-to-satellite ranging measurements. An inversion is performed for the major constituents M-2, O-1, and S-2, with K-1 excluded because of inadequate phase sampling. The tides are parameterized as localized average mass anomalies over areas approximately 300(2) km(2); other parameters, including satellite state adjustments, are estimated simultaneously with the tides. Qualitative comparison of our solutions with in situ tide measurements shows agreement in spatial pattern, clearly indicating regions where our adopted prior model is inadequate. To exploit these solutions, follow-on work must assimilate these long-wavelength components into a high-resolution numerical tidal model. C1 NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Han, SC (reprint author), NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Code 698, Greenbelt, MD 20771 USA. EM schan@puuoo.gsfc.nasa.gov; ray@nemo.gsfc.nasa.gov; sluthcke@puuoo.gsfc.nasa.gov RI Ray, Richard/D-1034-2012; Luthcke, Scott/D-6283-2012; Han, Shin-Chan/A-2022-2009 NR 14 TC 14 Z9 14 U1 0 U2 1 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 10 PY 2007 VL 34 IS 21 AR L21607 DI 10.1029/2007GL031540 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 230BJ UT WOS:000250850000006 ER PT J AU Putman, WM Lin, SH AF Putman, William M. Lin, Shian-Hann TI Finite-volume transport on various cubed-sphere grids SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE cubed-sphere; finite-volume; advection; transport schemes; monotonicity ID BAROTROPIC VORTICITY EQUATION; SEMI-LAGRANGIAN ADVECTION; GENERAL-CIRCULATION MODEL; SHALLOW-WATER MODEL; POSITIVE-DEFINITE; SCHEMES; APPROXIMATIONS; FORMULATION; INTEGRATION; SIMULATION AB The performance of a multidimensional finite-volume transport scheme is evaluated on the cubed-sphere geometry. Advection tests with prescribed winds are used to evaluate a variety of cubed-sphere projections and grid modifications including the gnomonic and conformal mappings, as well as two numerically generated grids by an elliptic solver and spring dynamics. We explore the impact of grid non-orthogonality on advection tests over the corner singularities of the cubedsphere grids, using some variations of the transport scheme, including the piecewise parabolic method with alternative monotonicity constraints. The advection tests revealed comparable or better accuracy to those of the original latitudinal-longitudinal grid implementation. It is found that slight deviations from orthogonality on the modified cubed-sphere (quasi-orthogonal) grids do not negatively impact the accuracy. In fact, the more uniform version of the quasi-orthogonal cubed-sphere grids provided better overall accuracy than the most orthogonal (and therefore, much less uniform) conformal grid. It is also shown that a simple non-orthogonal extension to the transport equation enables the use of the highly non-orthogonal and computationally more efficient gnomonic grid with acceptable accuracy. Published by Elsevier Inc. C1 NASA, Goddard Space Flight Ctr, Software Integrat & Visualizat Off, Greenbelt, MD 20771 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08540 USA. RP Putman, WM (reprint author), NASA, Goddard Space Flight Ctr, Software Integrat & Visualizat Off, Mail Stop 6103, Greenbelt, MD 20771 USA. EM William.M.Putman@nasa.gov NR 34 TC 126 Z9 128 U1 0 U2 5 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 NOV 10 PY 2007 VL 227 IS 1 BP 55 EP 78 DI 10.1016/j.jcp.2007.07.022 PG 24 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 234DE UT WOS:000251140100004 ER PT J AU Quinn, RC Ehrenfreund, P Grunthaner, FJ Taylor, CL Zent, AP AF Quinn, R. C. Ehrenfreund, P. Grunthaner, F. J. Taylor, C. L. Zent, A. P. TI Decomposition of aqueous organic compounds in the Atacama Desert and in Martian soils SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES LA English DT Article ID GAS-EXCHANGE EXPERIMENT; PHOTO-FENTON REACTION; MARS-LIKE SOILS; HYDROGEN-PEROXIDE; SURFACE-CHEMISTRY; NITRATE DEPOSITS; VIKING; LIFE; OXIDATION; SEARCH AB Carbon-13 labeled formate, alanine, and glucose decompose when added in aqueous solution to soils collected from the "Mars-like'' Yungay region ( S 24 degrees 4' 9.6 '', W 69 degrees 51') of the Atacama Desert. During the first 5 d of incubation, alanine ( 5 mM) and glucose (5 mM) solutions decomposed at rates of 0.1 to 0.2 mu mol/d, and formate solution ( 50 mM) decomposed at rates of 0.4 to 1.6 mu mol/ d. The observation of approximately equal (13)CO(2) initial production rates by soils treated with D-glucose and L-alanine, compared to soils treated with L-glucose and D-alanine, indicates the presence of one or more nonbiological chemical decomposition mechanisms. An increase in the decomposition rates of D-glucose and L-alanine, compared to L-glucose and D-alanine similar to 5 d after the addition of these organics, demonstrates that the soils are also biologically active. When treated with sodium formate solution, tested soils released (13)CO(2) gas in a manner that reproduces the initial gas release observed in the Mars Viking Labeled Release (LR) experiment. Our results indicate that the (13)CO(2) produced in Yungay soils is consistent with an initial phase of nonbiological decomposition followed by biological decomposition of added organics. Heat treatment of Yungay soils eliminated all CO(2) production, while in the Viking LR experiment, the initial rapid CO(2) release was eliminated by heat treatment, but a slower secondary CO(2) production was not. Our results indicate that the mechanism for the decomposition of organics in Yungay soils is different from the processes observed in the Viking LR experiment. C1 NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. Leiden Univ, Leiden Inst Chem, Astrobiol Grp, NL-2300 RA Leiden, Netherlands. Leiden Univ, NASA, Jet Propuls Lab, In Situ Explorat Technol Grp, Pasadena, CA USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Quinn, RC (reprint author), NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. NR 43 TC 16 Z9 16 U1 0 U2 8 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 10 PY 2007 VL 112 IS G4 AR G04S18 DI 10.1029/2006JG000312 PG 9 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 230CI UT WOS:000250852800003 ER PT J AU Aslam, S Jones, H Lakew, B AF Aslam, S. Jones, H. Lakew, B. TI Low-frequency noise measurements of high-T-c superconducting films: effect of DC capacitor in experimental setup SO ELECTRONICS LETTERS LA English DT Article AB Often a transformer is used with a DC-blocking capacitor as a voltage gain stage in experimental setups that measure low-frequency noise in high-T-c superconducting films. Presented is a system response analysis to show that the value of the DC-blocking capacitor determines the validity of the lower frequency limit of the measured noise voltage spectral density data. C1 [Aslam, S.] MEI Technol, Seabrook, MD 20706 USA. [Jones, H.; Lakew, B.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Aslam, S (reprint author), MEI Technol, Seabrook, MD 20706 USA. EM saslam@pop200.gsfc.nasa.gov RI Aslam, Shahid/D-1099-2012 NR 5 TC 0 Z9 0 U1 0 U2 1 PU INST ENGINEERING TECHNOLOGY-IET PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD NOV 8 PY 2007 VL 43 IS 23 BP 1320 EP 1321 DI 10.1049/el:20072102 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 242XJ UT WOS:000251759200050 ER PT J AU Signorini, SR McClain, CR AF Signorini, Sergio R. McClain, Charles R. TI Large-scale forcing impact on biomass variability in the South Atlantic Bight SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STATES CONTINENTAL-SHELF; GULF-STREAM INTRUSION; SEA-SURFACE HEIGHT; CAPE-HATTERAS; FLORIDA STRAITS; NORTH-CAROLINA; ONSLOW BAY; OCEAN; WATERS; MARGIN AB The Gulf Stream western front (GSF) follows the shelf slope topography for a great extent of the South Atlantic Bight (SAB). Sub-surface intrusions of the Gulf Stream are known to provide nutrient-rich waters to the outer shelf regions of the SAB and, consequently, promote phytoplankton growth. These intrusions are much more frequent during summer and are responsible for a significant portion of the annual SAB shelf carbon production. Based on the analysis of satellite ocean color data, sea surface temperature (SST), sea surface height (SSH), and climatologic data sets, we present evidence for a connection between these Gulf Stream intrusions and the seasonal variability of the size and strength of the North Atlantic Subtropical Gyre (NASG). The intensity and frequency of intrusions depend on the proximity of the GSF to the shelf, which is modulated by the seasonal expansion and contraction of the NASG. C1 Sci Applicat Int Corp, Beltsville, MD 20705 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Signorini, SR (reprint author), Sci Applicat Int Corp, 4600 Powder Mill Rd, Beltsville, MD 20705 USA. EM sergio@seawifs.gsfc.nasa.gov NR 30 TC 5 Z9 5 U1 2 U2 7 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 8 PY 2007 VL 34 IS 21 AR L21605 DI 10.1029/2007GL031121 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 230BH UT WOS:000250849800001 ER PT J AU Lu, J Fang, ZZ Sohn, HY Bowman, RC Hwang, SJ AF Lu, Jun Fang, Zhigang Zak Sohn, Hong Yong Bowman, Robert C., Jr. Hwang, Son-Jong TI Potential and reaction mechanism of Li-Mg-Al-N-H system for reversible hydrogen storage SO JOURNAL OF PHYSICAL CHEMISTRY C LA English DT Article ID SODIUM ALUMINUM-HYDRIDE; THERMAL-DECOMPOSITION; LITHIUM AMIDE; LIALH4; DEHYDROGENATION; TRANSFORMATIONS; CATALYST; IMIDES AB Complex metal hydrides are attracting much attention as a class of candidate materials for hydrogen storage. Lithium-based complex hydrides, including lithium aluminum hydrides (LiAlH4 and Li3AlH6), are among the most promising materials, owing to their high hydrogen contents. In the present work, we investigated the dehydrogenation/rehydrogenation reactions of a combined system of Li3AlH6 and Mg(NH2)(2), which has a theoretical hydrogen capacity of 6.5 wt %. Thermogravimetric analysis of hydrogenated (2)/Al-3-Li2Mg(NH)(2) (doped with 4 wt % TiCl3) indicated that a large amount of hydrogen (similar to 6.2 wt %) can be stored under 300 degrees C and 172 bar of hydrogen pressure. The FT-IR and NMR results showed that the reaction between Li3AlH6 and Mg(NH2)(2) is reversible. Further, a short-cycle experiment has demonstrated that the new combined material system of alanates and amides can maintain its hydrogen storage capacity upon cycling of the dehydrogenation/rehydrogenation reactions. C1 Univ Utah, Dept Engn Met, Salt Lake City, UT 84112 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Dept Chem & Chem Engn, Pasadena, CA 91125 USA. RP Fang, ZZ (reprint author), Univ Utah, Dept Engn Met, 135 S 1460 E Room 412, Salt Lake City, UT 84112 USA. EM zak.fang@utah.edu OI Bowman, Robert/0000-0002-2114-1713 NR 42 TC 22 Z9 23 U1 1 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1932-7447 J9 J PHYS CHEM C JI J. Phys. Chem. C PD NOV 8 PY 2007 VL 111 IS 44 BP 16686 EP 16692 DI 10.1021/jp074814e PG 7 WC Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 227HE UT WOS:000250647000085 ER PT J AU Prakash, GKS Smart, MC Olah, GA Narayanan, SR Chun, W Surampudi, S Halpert, G AF Prakash, G. K. S. Smart, M. C. Olah, G. A. Narayanan, S. R. Chun, W. Surampudi, S. Halpert, G. TI Performance of dimethoxymethane and trimethoxymethane in liquid-feed direct oxidation fuel cells SO JOURNAL OF POWER SOURCES LA English DT Article DE direct oxidation fuel cell; dimethoxymethane; trimethoxymethane; methanol ID TIME MASS-SPECTROMETRY; FORMIC-ACID OXIDATION; ETHYLENE-GLYCOL; EXCHANGE MEMBRANE; DIMETHYL ETHER; ELECTROLYTE; METHANOL; ELECTROOXIDATION; ETHANOL; FORMALDEHYDE AB The present study involves the evaluation of dimethoxymethane (DMM) (formaldehyde dimethyl acetal, or methylal) and trimethoxymethane (TMM) (trimethyl orthoformate) in direct oxidation liquid-feed fuel cells as novel oxygenated fuels. We have demonstrated that sustained oxidation of TMM at high current densities can be achieved in half-cells and liquid-feed polymer electrolyte fuel cells [1-3]. In the present study, the performance of dimethoxymethane and trimethoxymethane was compared with that of methanol in 2 '' x 2 '' (25 cm(2) electrode area) and 4 '' x 6 '' (160 cm2 electrode area) direct oxidation fuel cells. The impact of various parameters upon cell performance, such as cell temperature, anode fuel concentration, cathode fuel pressure and flow (O-2 and air), was investigated. Fuel crossover rates in operating fuel cells were also measured for methanol, DMM, and TMM and characterized in terms of concentration and temperature effects. Although DMM and more particularly TMM may present some logistical advantages over that of methanol, such as possessing a higher boiling point, higher flash point, and lower toxicity, the overall performance was observed to be inferior to that of methanol under typical fuel cell operating conditions. Published by Elsevier B.V. C1 Univ So Calif, Donald P & Katherine B Loker Hydrocarbon Res Inst, Los Angeles, CA 90089 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Smart, MC (reprint author), Univ So Calif, Donald P & Katherine B Loker Hydrocarbon Res Inst, Univ Pk, Los Angeles, CA 90089 USA. EM Marshall.C.Smart@jpl.nasa.gov NR 36 TC 7 Z9 8 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD NOV 8 PY 2007 VL 173 IS 1 BP 102 EP 109 DI 10.1016/j.jpowsour.2007.05.003 PG 8 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 232CG UT WOS:000250995200013 ER PT J AU Zhang, K Kimball, JS McDonald, KC Cassano, JJ Running, SW AF Zhang, Ke Kimball, John S. McDonald, Kyle C. Cassano, John J. Running, Steven W. TI Impacts of large-scale oscillations on pan-Arctic terrestrial net primary production SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NORTH-AMERICA; CLIMATE; TEMPERATURE AB Analyses of regional climate oscillations and satellite remote sensing derived net primary production ( NPP) and growing season dynamics for the pan- Arctic region indicate that the oscillations influence NPP by regulating seasonal patterns of low temperature and moisture constraints to photosynthesis. Early- spring ( Feb - Apr) patterns of the Arctic Oscillation ( AO) are proportional to growing season onset ( r = - 0.653; P = 0.001), while growing season patterns of the Pacific Decadal Oscillation ( PDO) are proportional to plant- available moisture constraints to NPP ( I-m) ( r = - 0.471; P = 0.023). Relatively strong, negative PDO phases from 1988 - 1991 and 1998 - 2002 coincided with prolonged regional droughts indicated by a standardized moisture stress index. These severe droughts resulted in widespread reductions in NPP, especially for relatively drought prone boreal forest and grassland/ cropland ecosystems. The influence of AO and PDO patterns on northern vegetation productivity appears to be decreasing and increasing, respectively, as low temperature constraints to plant growth relax and NPP becomes increasingly limited by available water supply under a warming climate. C1 Univ Montana, Flathead Lake Biol Stn, Polson, MT 59860 USA. Univ Montana, Numer Terradynam Simulat Grp, Missoula, MT 59812 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91101 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. RP Zhang, K (reprint author), Univ Montana, Flathead Lake Biol Stn, 32125 Bio Stn Lane, Polson, MT 59860 USA. EM zhang@ntsg.umt.edu RI Zhang, Ke/B-3227-2012 OI Zhang, Ke/0000-0001-5288-9372 NR 27 TC 13 Z9 13 U1 1 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 7 PY 2007 VL 34 IS 21 AR L21403 DI 10.1029/2007GL031605 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 230BG UT WOS:000250849700007 ER PT J AU Phillips, CB Burr, DM Beyer, RA AF Phillips, Cynthia B. Burr, Devon M. Beyer, Ross A. TI Mass movement within a slope streak on Mars SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ORBITER CAMERA; SURFACE-PROPERTIES; DUST; MISSION AB Slope streaks on Mars represent a currently active geological process. Various theories for slope streak formation have suggested that slope streaks form by disturbing only a thin surface veneer, or by staining of the surface, preserving pre-existing topography within the streak. Theories also vary as to whether the formation mechanism requires the presence of water or another liquid. We present observations of a slope streak that reveal topographic mounds within the streak. These mounds do not continue outside the streak, and we suggest that they formed with, or immediately after, the slope streak. We use estimates of the total volume of mounds in this particular streak, compared with the estimated excavation volume, to extrapolate to a global sediment transport rate from slope streak formation. If this slope streak is typical, then this calculated rate is greater than estimates of the total volume of material transported by dust storms each year. C1 Carl Sagan Ctr Study Life Universe, SETI Inst, Mountain View, CA USA. NASA, Ames Res Ctr, Moffett Field, CA USA. RP Phillips, CB (reprint author), Carl Sagan Ctr Study Life Universe, SETI Inst, Mountain View, CA USA. EM phillips@seti.org OI Beyer, Ross/0000-0003-4503-3335 NR 27 TC 12 Z9 12 U1 0 U2 1 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 6 PY 2007 VL 34 IS 21 AR L21202 DI 10.1029/2007GL031577 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 230BF UT WOS:000250849600004 ER PT J AU Ray, RD AF Ray, Richard D. TI Propagation of the overtide M-4 through the deep Atlantic Ocean SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TIDES; TOPEX/POSEIDON; ALTIMETRY; SHELF AB The nonlinear overtide M-4 is generated in shallow waters and is generally no more than a few mm amplitude in the deep ocean. Such small, periodic waves can now be mapped empirically by analyzing the long (15-year) time series of Topex/Poseidon and Jason-1 satellite altimetry. In a few locations of the deep Atlantic, M-4 amplitudes reach nearly 10 mm, confirming recent modeling efforts by Lyard and colleagues. These relatively large amplitudes evidently represent a complex interference pattern of free waves radiating from a few shallow sources, especially the Patagonian Shelf. They form approximately a standing-wave resonance in the Gulf of Guinea. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ray, RD (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM richard.ray@nasa.gov RI Ray, Richard/D-1034-2012 NR 15 TC 14 Z9 14 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 6 PY 2007 VL 34 IS 21 AR L21602 DI 10.1029/2007GL031618 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 230BF UT WOS:000250849600005 ER PT J AU Szego, K Bebesi, Z Bertucci, C Coates, AJ Crary, F Erdos, G Hartle, R Sittler, EC Young, DT AF Szego, K. Bebesi, Z. Bertucci, C. Coates, A. J. Crary, F. Erdos, G. Hartle, R. Sittler, E. C., Jr. Young, D. T. TI Charged particle environment of Titan during the T9 flyby SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB The ion measurements of the Cassini Plasma Spectrometer are presented which were acquired on 26 December 2005, during the T9 flyby at Titan. The plasma flow and magnetic field directions in the distant plasma environment of the moon were distinctly different from the other flybys. The near-Titan environment, dominated by ions of Titan origin, had a split signature, each with different ion composition; the first region was dominated by dense, slow, and cold ions in the 16-19 and 28-40 amu mass range, the second region contained only ions with mass 1 and 2, much less dense and less slow. Magnetospheric ions penetrate marginally into region 1, whereas the region-2 ion population is mixed. A detailed analysis has led us to conclude that the first event was due to the crossing of the mantle of Titan, whereas the second one very likely was a wake crossing. The split indicates the non-convexity of the ion-dominated volume around Titan. Both ion distributions are analysed in detail. C1 Hungarian Acad Sci, Cent Res Inst Phys, Res Inst Nucl & Particle Phys, H-1525 Budapest, Hungary. Univ London Imperial Coll Sci Technol & Med, Space & Atmospher Phys Grp, London SW7 2BZ, England. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. SW Res Inst, San Antonio, TX 78228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Szego, K (reprint author), Hungarian Acad Sci, Cent Res Inst Phys, Res Inst Nucl & Particle Phys, POB 49, H-1525 Budapest, Hungary. EM szego@rmki.kfki.hu RI Coates, Andrew/C-2396-2008; OI Coates, Andrew/0000-0002-6185-3125; Bertucci, Cesar/0000-0002-2540-5384 FU Science and Technology Facilities Council [PP/D00084X/1] NR 6 TC 27 Z9 27 U1 0 U2 0 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 6 PY 2007 VL 34 IS 24 AR L24S03 DI 10.1029/2007GL030677 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 230BO UT WOS:000250850600001 ER PT J AU Nassar, R Bernath, PF Boone, CD Gettelman, A McLeod, SD Rinsland, CP AF Nassar, Ray Bernath, Peter F. Boone, Chris D. Gettelman, Andrew McLeod, Sean D. Rinsland, Curtis P. TI Variability in HDO/H2O abundance ratios in the tropical tropopause layer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC WATER-VAPOR; INFRARED SOLAR SPECTRA; ISOTOPIC COMPOSITION; DEHYDRATION; TROPOSPHERE; CONVECTION; TRANSPORT; HDO; METHANE; SPECTROMETER AB The dehydration of air in the tropical tropopause layer ( TTL) and mechanisms for the entry of water vapor into the stratosphere are investigated by an analysis of ACE-FTS profiles of temperature, water vapor, and the ratio [HDO]/[H2O] expressed in delta D notation. Month-to-month comparisons indicate greater seasonal variability than interannual variability between 25 degrees S-25 degrees N, thus comparisons are made between February, April, August, and October averages for the years 2004 and 2005 combined. The data indicate a pattern of seasonal variability which is clearer in the Northern Hemisphere tropics and a relationship between minimum temperature, minimum water vapor, and maximum HDO depletion, which exists beyond the estimated uncertainty in these values. The range of values observed for HDO depletion and comparisons to modeled Rayleigh distillation curves indicate an important contribution from convection in addition to gradual dehydration. Multiple factors including the shape of the delta D profiles suggest that a likely mechanism for the convective influence is the lofting of ice particles in the tropical troposphere. C1 Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 02138 USA. Univ Waterloo, Dept Chem, Waterloo, ON, Canada. Univ York, Dept Chem, N York, ON M3J 1P3, Canada. Natl Ctr Atmospher Res, Boulder, CO USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Nassar, R (reprint author), Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 02138 USA. RI Bernath, Peter/B-6567-2012; OI Bernath, Peter/0000-0002-1255-396X; Nassar, Ray/0000-0001-6282-1611 NR 51 TC 31 Z9 31 U1 0 U2 11 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 6 PY 2007 VL 112 IS D21 AR D21305 DI 10.1029/2007JD008417 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 230BQ UT WOS:000250850800001 ER PT J AU Kegerise, MA Cabell, RH Cattafesta, LN AF Kegerise, M. A. Cabell, R. H. Cattafesta, L. N., III TI Real-time feedback control of flow-induced cavity tones - Part 1: Fixed-gain control SO JOURNAL OF SOUND AND VIBRATION LA English DT Article; Proceedings Paper CT AIAA 42nd Aerospace Sciences Meeting and Exhibit CY JAN 05-08, 2004 CL Reno, NV SP Amer Inst Aeronaut & Astronaut ID GENERALIZED PREDICTIVE CONTROL; OSCILLATIONS AB A generalized predictive control (GPC) algorithm was formulated and applied to the cavity flow-tone problem. The control algorithm demonstrated multiple Rossiter-mode suppression at fixed Mach numbers ranging from 0.275 to 0.38. Controller performance was evaluated with a measure of output disturbance rejection and an input sensitivity transfer function. The results suggest that disturbances entering the cavity flow are collocated with the control input at the cavity leading edge. In that case, only tonal components of the cavity wall-pressure fluctuations can be suppressed and arbitrary broadband pressure reduction is not possible with the present sensor/actuator arrangement. In the control algorithm development, the cavity dynamics were treated as linear and time invariant for a fixed Mach number. The experimental results lend support to that treatment. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Flow Phys & Control Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. Univ Florida, Gainesville, FL 32611 USA. RP Kegerise, MA (reprint author), NASA, Langley Res Ctr, Flow Phys & Control Branch, Mail Stop 170, Hampton, VA 23681 USA. EM michael.a.kegerise@nasa.gov RI Cattafesta, Louis/A-9545-2015 OI Cattafesta, Louis/0000-0002-5767-3383 NR 40 TC 8 Z9 10 U1 0 U2 5 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD NOV 6 PY 2007 VL 307 IS 3-5 BP 906 EP 923 DI 10.1016/j.jsv.2007.07.063 PG 18 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 220DN UT WOS:000250137200028 ER PT J AU Kegerise, MA Cabell, RH Cattafesta, LN AF Kegerise, M. A. Cabell, R. H. Cattafesta, L. N., III TI Real-time feedback control of flow-induced cavity tones - Part 2: Adaptive control SO JOURNAL OF SOUND AND VIBRATION LA English DT Article; Proceedings Paper CT AIAA 42nd Aerospace Sciences Meeting and Exhibit CY JAN 05-08, 2004 CL Reno, NV SP Amer Inst Aeronaut & Astronaut ID FILTER AB An adaptive generalized predictive control (GPC) algorithm was formulated and applied to the cavity flow-tone problem. The algorithm employs gradient descent to update the GPC coefficients at each time step. Past input-output data and an estimate of the open-loop pulse response sequence are all that is needed to implement the algorithm for application at fixed Mach numbers. Transient measurements made during controller adaptation at fixed Mach number revealed that the controller coefficients converged to a steady state in the mean, and this implies that adaptation can be turned off at some point with no degradation in control performance. The control algorithm demonstrated multiple Rossiter mode suppression at fixed Mach numbers of 0.275, 0.32, and 0.38, provided the plant model was updated for each Mach number. However, as in the case of fixed-gain GPC, the adaptive GPC was limited by spillover in sidebands around the suppressed Rossiter modes. The algorithm was also able to maintain suppression of multiple cavity tones as the freestream Mach number was varied over a modest range (0.275-0.29). Beyond this range, stable operation of the control algorithm was not possible due to the fixed plant model in the algorithm. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Flow Phys & Control Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. Univ Florida, Gainesville, FL 32611 USA. RP Kegerise, MA (reprint author), NASA, Langley Res Ctr, Flow Phys & Control Branch, Mail Stop 170, Hampton, VA 23681 USA. EM michael.a.kegerise@nasa.gov RI Cattafesta, Louis/A-9545-2015 OI Cattafesta, Louis/0000-0002-5767-3383 NR 21 TC 6 Z9 7 U1 0 U2 3 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD NOV 6 PY 2007 VL 307 IS 3-5 BP 924 EP 940 DI 10.1016/j.jsv.2007.07.062 PG 17 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 220DN UT WOS:000250137200029 ER PT J AU Keene, WC Maring, H Maben, JR Kieber, DJ Pszenny, AAP Dahl, EE Izaguirre, MA Davis, AJ Long, MS Zhou, XL Smoydzin, L Sander, R AF Keene, William C. Maring, Hal Maben, John R. Kieber, David J. Pszenny, Alexander A. P. Dahl, Elizabeth E. Izaguirre, Miguel A. Davis, Andrew J. Long, Michael S. Zhou, Xianliang Smoydzin, Linda Sander, Rolf TI Chemical and physical characteristics of nascent aerosols produced by bursting bubbles at a model air-sea interface SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MARINE BOUNDARY-LAYER; PARTICULATE ORGANIC-CARBON; FILM DROP PRODUCTION; SIDE-SCAN SONAR; SALT AEROSOL; OZONE DESTRUCTION; REACTIVE CHLORINE; CAPE GRIM; SURFACE; SEAWATER AB Breaking waves on the ocean surface produce bubbles that, upon bursting, inject seawater constituents into the atmosphere. Nascent aerosols were generated by bubbling zero-air through flowing seawater within an RH-controlled chamber deployed at Bermuda and analyzed for major chemical and physical characteristics. The composition of feed seawater was representative of the surrounding ocean. Relative size distributions of inorganic aerosol constituents were similar to those in ambient air. Ca2+ was significantly enriched relative to seawater ( median factor = 1.2). If in the form of CaCO3, these enrichments would have important implications for pH-dependent processes. Other inorganic constituents were present at ratios indistinguishable from those in seawater. Soluble organic carbon ( OC) was highly enriched in all size fractions ( median factor for all samples = 387). Number size distributions exhibited two lognormal modes. The number production flux of each mode was linearly correlated with bubble rate. At 80% RH, the larger mode exhibited a volume centroid of similar to 5-mu m diameter and included similar to 95% of the inorganic sea-salt mass; water comprised 79% to 90% of volume. At 80% RH, the smaller mode exhibited a number centroid of 0.13-mu m diameter; water comprised 87% to 90% of volume. The median mass ratio of organic matter to sea salt in the smallest size fraction ( geometric mean diameter = 0.13 mu m) was 4:1. These results support the hypothesis that bursting bubbles are an important global source of CN and CCN with climatic implications. Primary marine aerosols also influence radiative transfer via multiphase processing of sulfur and other climate-relevant species. C1 Univ Virginia, Dept Environm Sci, Charlottesville, VA 22904 USA. SUNY Syracuse, Coll Environm Sci & Forestry, Dept Chem, Syracuse, NY 13210 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. NASA, Radiat Sci Program, Washington, DC 20546 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Max Planck Inst Chem, Air Chem Dept, D-55020 Mainz, Germany. SUNY Albany, Sch Publ Hlth, New York State Dept Hlth, Wadsworth Ctr, Albany, NY 12201 USA. Heidelberg Univ, Inst Environm Phys, Heidelberg, Germany. RP Keene, WC (reprint author), Univ Virginia, Dept Environm Sci, Charlottesville, VA 22904 USA. EM wck@virginia.edu RI Sander, Rolf/A-5725-2011 OI Sander, Rolf/0000-0001-6479-2092 NR 79 TC 108 Z9 110 U1 6 U2 52 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 3 PY 2007 VL 112 IS D21 AR D21202 DI 10.1029/2007JD008464 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 228CQ UT WOS:000250705100002 ER PT J AU Baker, JG van Meter, JR McWilliams, ST Centrella, J Kelly, BJ AF Baker, John G. van Meter, James R. McWilliams, Sean T. Centrella, Joan Kelly, Bernard J. TI Consistency of post-Newtonian waveforms with numerical relativity SO PHYSICAL REVIEW LETTERS LA English DT Article ID COMPACT BINARIES AB General relativity predicts the gravitational wave signatures of coalescing binary black holes. Explicit waveform predictions for such systems, required for optimal analysis of observational data, have so far been achieved primarily using the post-Newtonian (PN) approximation. The quality of this treatment is unclear, however, for the important late-inspiral portion. We derive late-inspiral waveforms via a complementary approach, direct numerical simulation of Einstein's equations. We compare waveform phasing from simulations of the last similar to 14 cycles of gravitational radiation from equal-mass, nonspinning black holes with the corresponding 2.5PN, 3PN, and 3.5PN orbital phasing. We find phasing agreement consistent with internal error estimates for either approach, suggesting that PN waveforms for this system are effective until the last orbit prior to final merger. C1 NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Phys, Ctr Space Sci & Technol, Baltimore, MD 21250 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Baker, JG (reprint author), NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. RI van meter, james/E-7893-2011; Kelly, Bernard/G-7371-2011; OI Kelly, Bernard/0000-0002-3326-4454 NR 21 TC 96 Z9 96 U1 0 U2 1 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 NOV 2 PY 2007 VL 99 IS 18 AR 181101 DI 10.1103/PhysRevLett.99.181101 PG 4 WC Physics, Multidisciplinary SC Physics GA 227GA UT WOS:000250644000012 PM 17995394 ER PT J AU Petropoulos, AE Kowalkowski, TD Vavrina, MA Parcher, DW Finlayson, PA Whiffen, GJ Sims, JA AF Petropoulos, Anastassios E. Kowalkowski, Theresa D. Vavrina, Matthew A. Parcher, Daniel W. Finlayson, Paul A. Whiffen, Gregory J. Sims, Jon A. TI 1st ACT global trajectory optimisation competition: Results found at the Jet Propulsion Laboratory SO ACTA ASTRONAUTICA LA English DT Article DE trajectory design; global optimisation; low thrust; electric propulsion; gravity assist; asteroid deflection AB Results obtained at the Jet Propulsion Laboratory for the 1st ACT global trajectory optimisation competition are presented and the methods used to obtain them are described. The search for the globally optimal, low-thrust, gravity-assist trajectory for maximally deflecting an asteroid is performed in two steps. The first step involves a rough global search of the global search space, which has, however, been somewhat bounded based on prior mission-design experience, intuition, and energy arguments. A shape-based method is used to represent the low-thrust arcs, while the ballistic portions are searched almost exhaustively. The second step involves local optimisation of trajectories which stand out from the rough global search. The low-thrust optimisation problem is turned into a parameter optimisation problem by approximating the continuous thrusting as a series of impulsive manoeuvres. Of the many trajectories found, three optimal trajectories are reported and compared, including the one submitted for the competition. The best one employed a double-Venus, quadruple-Earth, Jupiter-Saturn-Jupiter gravity-assist sequence. The trajectory submitted for the competition used one less Venus flyby and one less Earth flyby. (C) 2007 Published by Elsevier Ltd. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Petropoulos, AE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM anastassios.e.petropoulos@jpl.nasa.gov NR 9 TC 5 Z9 7 U1 0 U2 8 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 NOV PY 2007 VL 61 IS 9 BP 806 EP 815 DI 10.1016/j.actaastro.2007.03.013 PG 10 WC Engineering, Aerospace SC Engineering GA 206GV UT WOS:000249172800012 ER PT J AU Matousek, S AF Matousek, Steve TI The Juno New Frontiers mission SO ACTA ASTRONAUTICA LA English DT Article AB Peering down through the clouds and deep into Jupiter's atmosphere, Juno reveals fundamental processes of the formation and early evolution of our solar system. Using a simple, solar powered, spinning spacecraft in an innovative, highly elliptical polar orbit, Juno avoids Jupiter's highest radiation regions. The mission combines high heritage instruments and spacecraft with an experienced science and engineering team. The designs of the individual instruments are straightforward and have excellent heritage from previous space missions. Juno's scientific payload includes a dual frequency gravity/radio science system, a six wavelength Microwave Radiometer (MWR) for atmospheric sounding and composition, a dual-technique magnetometer, plasma detectors, energetic particle detectors (EPDs), a radio/plasma wave experiment, and an Ultraviolet Imager/Spectrometer. Juno's payload also includes a color camera to provide the public with their first glimpse of Jupiter's poles. Juno will launch in July, 2010 or August, 2011 and arrive at Jupiter 5.2 years later. The nominal mission ends one year after Jupiter arrival with a deorbit into Jupiter's atmosphere. (C) 2007 Published by Elsevier Ltd. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Matousek, S (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. EM Steven.E.Matousek@jpl.nasa.gov NR 0 TC 37 Z9 37 U1 4 U2 12 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 NOV PY 2007 VL 61 IS 10 BP 932 EP 939 DI 10.1016/j.actaastro.2006.12.013 PG 8 WC Engineering, Aerospace SC Engineering GA 224EY UT WOS:000250431500013 ER PT J AU Zaman, KBAQ Dahl, MD AF Zaman, K. B. A. Q. Dahl, M. D. TI Noise and spreading of subsonic coannular jets - Comparison with single equivalent jet 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 SIMPLE COAXIAL JETS; COMPRESSIBLE JETS; PRIMARY FLOW; SOUND; QUIET; FIELD AB The issue of scaling of noise as well as spreading of subsonic coannular jets is revisited. Far-field noise and centerline pitot-static pressure surveys are conducted with concentric, circular nozzles having an outer-to-inner diameter ratio of 1.42. Both the inner nozzle and the outer annular passage are convergent. Outer-to-inner Mach number ratio R is varied over a large range from 0 to about 10. Results are examined on the basis of single equivalent jet parameters calculated by satisfying continuity, momentum, and energy equations. The results confirm that coannular jets with "normal" velocity profiles are noisier than the equivalent jet. Jets with "inverted" velocity profiles are also found to be noisier except in the R range of 1-1.5. There, a few cases exhibit lower intensities (by a fraction of a dB) relative to the intensity at R = 1. However, other run conditions exhibit the lowest intensity at R = 1. Thus, the present data with unheated flow and the given nozzle geometry do not clearly exhibit noise reduction with the inverted velocity profile jets. For the flowfield, the asymptotic Mach number decay rates as well as the potential core lengths are found to be comparable to those of the equivalent jet. C1 NASA, John H Glenn Res Ctr Lewis Field, Aerpropuls Div, Inlet & Nozzle Branch, Cleveland, OH 44135 USA. NASA, John H Glenn Res Ctr Lewis Field, Aerpropuls Div, Acoust Branch, Cleveland, OH 44135 USA. RP Zaman, KBAQ (reprint author), NASA, John H Glenn Res Ctr Lewis Field, Aerpropuls Div, Inlet & Nozzle Branch, Mail Stop 5-12, Cleveland, OH 44135 USA. NR 19 TC 2 Z9 2 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 NOV PY 2007 VL 45 IS 11 BP 2661 EP 2670 DI 10.2514/1.29441 PG 10 WC Engineering, Aerospace SC Engineering GA 229AD UT WOS:000250772800007 ER PT J AU Shang, JS Chang, CL Surzhikov, ST AF Shang, J. S. Chang, C. L. Surzhikov, S. T. TI Simulating hypersonic magnetofluid-dynamic compression in rectangular inlet SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 37th Plasmadynamics and Lasers Conference CY JUN 05-08, 2006 CL San Francisco, CA SP AIAA ID FLOW-CONTROL AB The combined effects of an electromagnetic perturbation and viscous-inviscid interaction generate a high-pressure plateau near the hypersonic leading edge surface. The surface pressure induced by magnetofluid-dynamic interaction emulates a movable leading edge strake. This phenomenon has been verified in experimental research, which shows that a direct current surface discharge becomes a virtual compression ramp for flow control. More recently, investigation has extended to a rectangular hypersonic inlet. The present analysis solves the magnetofluid-dynamic equations using weakly ionized gas models, including the formulation based on the drift-diffusion theory. The numerical simulation provides a detailed description of the intriguing magnetofluid-dynamic interacting flowfield. After validation by experimental measurements, the computed results quantify the effectiveness of a magnetofluid-dynamic compression for a hypersonic inlet. Applying a plasma generation power input to a direct current surface discharge of 7.87 W per square centimeter of electrode area, the interaction produces an 11.7% higher compression of a constant cross-section inlet. C1 Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. NASA, Langley Res Ctr, Computat Aerosci Branch, Hampton, VA 23681 USA. Russian Acad Sci, Inst Problems Mech, Moscow 119526, Russia. RP Shang, JS (reprint author), Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. EM joseph.shang@wright.edu RI Surzhikov, Sergey/A-6149-2009 OI Surzhikov, Sergey/0000-0002-7772-0538 NR 34 TC 6 Z9 6 U1 1 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 NOV PY 2007 VL 45 IS 11 BP 2710 EP 2720 DI 10.2514/1.26086 PG 11 WC Engineering, Aerospace SC Engineering GA 229AD UT WOS:000250772800012 ER PT J AU Knowlton, K Lynn, B Goldberg, RA Rosenzweig, C Hogrefe, C Rosenthal, JK Kinney, PL AF Knowlton, Kim Lynn, Barry Goldberg, Richard A. Rosenzweig, Cynthia Hogrefe, Christian Rosenthal, Joyce Klein Kinney, Patrick L. TI Projecting heat-related mortality impacts under a changing climate in the New York City region SO AMERICAN JOURNAL OF PUBLIC HEALTH LA English DT Article ID EASTERN UNITED-STATES; US CITIES; AIR-POLLUTION; TIME-SERIES; TEMPERATURE; WAVE; CHICAGO; DEATHS; HEALTH; MODEL AB Objectives. We sought to project future impacts of climate change on summer heat-related premature deaths in the New York City metropolitan region. Methods. Current and future climates were simulated over the northeastern United States with a global-to-regional climate modeling system. Summer heat-related premature deaths in the 1990s and 2050s were estimated by using a range of scenarios and approaches to modeling acclimatization (e.g., increased use of air conditioning, gradual physiological adaptation). Results. Projected regional increases in heat-related premature mortality by the 2050s ranged from 47% to 95%, with a mean 70% increase compared with the 1990s. Acclimatization effects reduced regional increases in summer heat-related premature mortality by about 25%. Local impacts varied considerably across the region, with urban counties showing greater numbers of deaths and smaller percentage increases than less-urbanized counties. Conclusions. Although considerable uncertainty exists in climate forecasts and future health vulnerability, the range of projections we developed suggests that by midcentury, acclimatization may not completely mitigate the effects of climate change in the New York City metropolitan region, which would result in an overall net increase in heat-related premature mortality. C1 Columbia Univ, Mailman Sch Publ Hlth, Dept Environm Hlth Sci, New York, NY USA. Columbia Univ, Ctr Climate Syst Res, Goddard Inst Space Studies, New York, NY USA. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12222 USA. Columbia Univ, Grad Sch Architecture Planning & Preservat, New York, NY USA. RP Knowlton, K (reprint author), Columbia Univ, Nat Resources Drf Council, 40 W 20th St, New York, NY 10011 USA. EM kknowlton@nrdc.org RI Kinney, Patrick/H-7914-2012; Brooks, Katya/J-4975-2014 NR 47 TC 99 Z9 105 U1 5 U2 23 PU AMER PUBLIC HEALTH ASSOC INC PI WASHINGTON PA 800 I STREET, NW, WASHINGTON, DC 20001-3710 USA SN 0090-0036 EI 1541-0048 J9 AM J PUBLIC HEALTH JI Am. J. Public Health PD NOV PY 2007 VL 97 IS 11 BP 2028 EP 2034 DI 10.2105/AJPH.2006.102947 PG 7 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 225AJ UT WOS:000250489200025 PM 17901433 ER PT J AU Kiang, R Adimi, F Zollner, G Coleman, R AF Kiang, Richard Adimi, Farida Zollner, Gabriela Coleman, Russell TI Simulation of malaria transmission among households in a Thailand village using remotely sensed parameters SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Meeting Abstract CT 56th Annual Meeting of the American-Society-of-Tropical-Medicine-and-Hygiene CY NOV 04-08, 2007 CL Philadelphia, PA SP Amer Soc Trop Med & Hyg C1 [Kiang, Richard; Adimi, Farida] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. [Zollner, Gabriela; Coleman, Russell] Walter Reed Army Inst Res, Silver Spring, MD USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DR, STE 130, MCLEAN, VA 22101 USA SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD NOV PY 2007 VL 77 IS 5 SU S MA 185 BP 54 EP 54 PG 1 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA 228UN UT WOS:000250758200185 ER PT J AU Anyamba, A Chretien, JP Small, J Tucker, CJ Formenty, P Richardson, J Britch, S Linthicum, KJ AF Anyamba, Assaf Chretien, Jean-Paul Small, Jennifer Tucker, Compton J. Formenty, Pierre Richardson, Jason Britch, Seth Linthicum, Kenneth J. TI Forecasting the temporal and spatial distribution of a rift valley fever outbreak in east Africa: 2006-2007 SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Meeting Abstract CT 56th Annual Meeting of the American-Society-of-Tropical-Medicine-and-Hygiene CY NOV 04-08, 2007 CL Philadelphia, PA SP Amer Soc Trop Med & Hyg C1 [Anyamba, Assaf; Small, Jennifer; Tucker, Compton J.] Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD USA. [Chretien, Jean-Paul] Walter Reed Army Inst Res, Dept Def Global Emerging Infect, Surveillance & Response Syst, Silver Spring, MD USA. [Formenty, Pierre] WHO, Dept Epidem & Pandem Alert & Response, Geneva, Switzerland. [Richardson, Jason] US Army Med Res Unit, Dept Entomol, Nairobi, Kenya. [Britch, Seth; Linthicum, Kenneth J.] USDA ARS, Ctr Med Agr & Vet Entomol, Gainesville, FL USA. RI Richardson, Jason/A-9441-2011 NR 0 TC 1 Z9 1 U1 1 U2 3 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DR, STE 130, MCLEAN, VA 22101 USA SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD NOV PY 2007 VL 77 IS 5 SU S MA 989 BP 282 EP 283 PG 2 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA 228UN UT WOS:000250758201447 ER PT J AU Karner, JM Papike, JJ Sutton, SR Shearer, CK Mckay, G Le, L Burger, P AF Karner, J. M. Papike, J. J. Sutton, S. R. Shearer, C. K. McKay, G. Le, L. Burger, P. TI Valence state partitioning of Cr between pyroxene-melt: Effects of pyroxene and melt composition and direct determination of Cr valence states by XANES. Application to Martian basalt QUE 94201 composition SO AMERICAN MINERALOGIST LA English DT Letter DE chromium; partitioning; multivalent elements; pyroxene; XANES; QUE 94201 ID CHROMIUM; OLIVINE; SPINEL; LIQUID AB D-Cr augite/melt is approximately double that of D-Cr pigeonite/melt in synthetic Martian basaltic samples equilibrated at the same fo(2). This increase is not related to changing fo(2) and the valence of Cr, but rather to the increased availability of elements for coupled substitution with the Cr3+ ion, namely Na and Al. The availability of Al and Na to partition into pyroxene is due to delayed nucleation of plagioclase for the QUE 94201 Martian basalt composition. Direct valence state determination by XANES shows that Cr3+ is the dominant valence state in pyroxene at IW-1, IW, and IW+1. Trivalent Cr is apparently much more compatible in the pyroxene structure than divalent Cr, and thus an increasing D-Cr for both augite/melt and pigeonite/melt with increasing fo(2) is a function of the increased activity of Cr3+ in the crystallizing melt. C1 Univ New Mexico, Dept Earth & Planetary Sci, Astromat Inst, Albuquerque, NM 87131 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60637 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. ESC Grp, Houston, TX 77058 USA. RP Karner, JM (reprint author), Univ New Mexico, Dept Earth & Planetary Sci, Astromat Inst, Albuquerque, NM 87131 USA. EM jkarner@unm.edu NR 18 TC 10 Z9 10 U1 1 U2 8 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 2007 VL 92 IS 11-12 BP 2002 EP 2005 DI 10.2138/am.2007.2724 PG 4 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 233OU UT WOS:000251101000026 ER PT J AU Gatebe, CK Butler, JJ Cooper, JW Kowalewski, M King, MD AF Gatebe, Charles K. Butler, James J. Cooper, John W. Kowalewski, Matthew King, Michael D. TI Characterization of errors in the use of integrating-sphere systems in the calibration of scanning radiometers SO APPLIED OPTICS LA English DT Article ID AEROSOL AB Laboratory measurements were performed to characterize the geometrical effects in the calibration of the NASA's cloud absorption radiometer (CAR). The measurements involved three integrating sphere sources (ISSs) operated at different light levels and experimental setups to determine radiance variability. The radiance gradients across the three ISS apertures were 0.2%-2.6% for different visible, near-infrared, and shortwave infrared illumination levels but <15% in the UV. Change in radiance with distance was determined to be 2%-20%, being highest in the UV. Radiance variability due to the edge effects was found to be significant; as much as 70% due to the sphere aperture and <10% due to the CAR telescope's secondary mirror. (C) 2007 Optical Society of America. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Div Earth Sci, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Gatebe, CK (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RI King, Michael/C-7153-2011; Gatebe, Charles/G-7094-2011; Butler, James/D-4188-2013 OI King, Michael/0000-0003-2645-7298; Gatebe, Charles/0000-0001-9261-2239; NR 19 TC 9 Z9 10 U1 0 U2 1 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 NOV 1 PY 2007 VL 46 IS 31 BP 7640 EP 7651 DI 10.1364/AO.46.007640 PG 12 WC Optics SC Optics GA 237DV UT WOS:000251354500010 PM 17973008 ER PT J AU Bloemhof, EE Lam, JC Feria, VA Chang, Z AF Bloemhof, Eric E. Lam, Jonathan C. Feria, V. Alfonso Chang, Zensheu TI Precise determination of the zero-gravity surface figure of a mirror without gravity-sag modeling SO APPLIED OPTICS LA English DT Article AB The zero-gravity surface figure of optics used in spaceborne astronomical instruments must be known to high accuracy, but earthbound metrology is typically corrupted by gravity sag. Generally, inference of the zero-gravity surface figure from a measurement made under normal gravity requires finite-element analysis (FEA), and for accurate results the mount forces must be well characterized. We describe how to infer the zero-gravity surface figure very precisely using the alternative classical technique of averaging pairs of measurements made with the direction of gravity reversed. We show that mount forces as well as gravity must be reversed between the two measurements and discuss how the St. Venant principle determines when a reversed mount force may be considered to be applied at the same place in the two orientations. Our approach requires no finite-element modeling and no detailed knowledge of mount forces other than the fact that they reverse and are applied at the same point in each orientation. If mount schemes are suitably chosen, zero-gravity optical surfaces may be inferred much more simply and more accurately than with FEA. (C) 2007 Optical Society of America. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Bloemhof, EE (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. NR 8 TC 4 Z9 5 U1 0 U2 3 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 NOV 1 PY 2007 VL 46 IS 31 BP 7670 EP 7678 DI 10.1364/AO.46.007670 PG 9 WC Optics SC Optics GA 237DV UT WOS:000251354500013 PM 17973011 ER PT J AU Barnes, NP Walsh, BM Reichle, DJ Deyoung, RJ Jiang, SB AF Barnes, N. P. Walsh, B. M. Reichle, D. J. Deyoung, R. J. Jiang, Shibin TI Tm : germanate fiber laser: tuning and Q-switching SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID GLASS AB A Tm:germanate fiber laser produced > 0.25 mJ/ pulse in a 45 ns pulse. It is capable of producing multiple Q-switched pulses from a single pump pulse. With the addition of a diffraction grating, Tm:germanate fiber lasers produced a wide, but length dependent, tuning range. By selecting the fiber length, the tuning range extends from 1.88 to 2.04 mu m. These traits make Tm:germanate lasers suitable for remote sensing of water vapor. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NP Photon, Tucson, AZ USA. RP Barnes, NP (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM n.p.barnes@larc.nasa.gov NR 8 TC 12 Z9 15 U1 1 U2 13 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD NOV PY 2007 VL 89 IS 2-3 BP 299 EP 304 DI 10.1007/s00340-007-2794-4 PG 6 WC Optics; Physics, Applied SC Optics; Physics GA 227AP UT WOS:000250629900028 ER PT J AU Jewitt, D Peixinho, N Hsieh, HH AF Jewitt, David Peixinho, Nuno Hsieh, Henry H. TI U-band photometry of kuiper belt objects SO ASTRONOMICAL JOURNAL LA English DT Article DE kuiper belt ID TRANS-NEPTUNIAN OBJECTS; DYNAMICAL CLASSIFICATION; PHASE FUNCTIONS; CENTAURS; COLORS; EVOLUTION; STARS; ROTATIONS; DIVERSITY; SILICATES AB We present U-band photometry of Kuiper Belt objects taken to further investigate their color-orbit systematics. As at longer optical and near-infrared wavelengths, the U-band colors of Kuiper Belt objects show a wide range and a unimodal distribution. We find no evidence that color systematics in the Kuiper Belt are strongly wavelength-dependent. This observation is consistent with control of the reflection characteristics by a single (but unidentified) reddening material. No evidence is found for blue/ultraviolet absorption that can arise from charge transfer transitions in hydrated minerals in some primitive (C-type) asteroids. In the classical KBOs alone the U-B and other color indices are most strongly correlated with the Tisserand parameter measured with respect to Neptune. C1 Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Coimbra, Grp Astrofis, Coimbra, Portugal. Univ Calif, WM Keck Observ, Berkeley, CA 94720 USA. NASA, Washington, DC 20546 USA. Queens Univ Belfast, Belfast, Antrim, North Ireland. RP Jewitt, D (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. EM jewitt@ifa.hawaii.edu; peixinho@ifa.hawaii.edu; h.hsieh@qub.ac.uk RI Peixinho, Nuno/B-2570-2014 OI Peixinho, Nuno/0000-0002-6830-476X NR 38 TC 11 Z9 11 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 NOV PY 2007 VL 134 IS 5 BP 2046 EP 2053 DI 10.1086/522787 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 225LC UT WOS:000250518400029 ER PT J AU Gilli, R Daddi, E Chary, R Dickinson, M Elbaz, D Giavalisco, M Kitzbichler, M Stern, D Vanzella, E AF Gilli, R. Daddi, E. Chary, R. Dickinson, M. Elbaz, D. Giavalisco, M. Kitzbichler, M. Stern, D. Vanzella, E. TI The spatial clustering of mid-IR selected star forming galaxies at z similar to 1 in the GOODS fields SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : evolution; cosmology : large-scale structure of universe; cosmology : observations ID LYMAN-BREAK GALAXIES; SPITZER-SPACE-TELESCOPE; ORIGINS DEEP SURVEY; ACTIVE GALACTIC NUCLEI; INITIAL MASS FUNCTION; EXTREMELY RED OBJECTS; DIGITAL SKY SURVEY; REDSHIFT SURVEY; SPECTRAL TYPE; POWER-LAW AB We present the first spatial clustering measurements of z similar to 1, 24 m- selected, star forming galaxies in the Great Observatories Origins Deep Survey (GOODS). The sample under investigation includes 495 objects in GOODS-South and 811 objects in GOODS- North selected down to flux densities of f(24) > 20 mu Jy and z(AB) < 23.5mag, for which spectroscopic redshifts are available. The median redshift, IR luminosity and star formation rate (SFR) of the sample are z similar to 0.8, LIR similar to 4.4 x 10(10) L-circle dot, and SFR similar to 7.6 M-circle dot yr(-1), respectively. We measure the projected correlation function w(r(p)) on scales of r(p) = 0.06-10 h(-1) Mpc, from which we derive a best fit comoving correlation length of r(0) = 4.0 +/- 0.4 h(-1) Mpc and slope of gamma = 1.5 +/- 0.1 for the whole f(24) > 20 mu Jy sample after combining the two fields. We find indications of a larger correlation length for objects of higher luminosity, with Luminous Infrared Galaxies (LIRGs, L-IR > 10(11) L-circle dot) reaching r(0) similar to 5.1 h(-1) Mpc. This would imply that galaxies with larger SFRs are hosted in progressively more massive halos, reaching minimum halo masses of similar to 3 x 10(12) M-circle dot for LIRGs. We compare our measurements with the predictions from semi-analytic models based on the Millennium simulation. The variance in the models is used to estimate the errors in our GOODS clustering measurements, which are dominated by cosmic variance. The measurements from the two GOODS fields are found to be consistent within the errors. On scales of the GOODS fields, the real sources appear more strongly clustered than objects in the Millennium-simulation based catalogs, if the selection function is applied consistently. This suggests that star formation at z similar to 0.5-1 is being hosted in more massive halos and denser environments than currently predicted by galaxy formation models. Mid- IR selected sources appear also to be more strongly clustered than optically selected ones at similar redshifts in deep surveys like the DEEP2 Galaxy Redshift Survey and the VIMOS- VLT Deep Survey ( VVDS), although the significance of this result is less than or similar to 3 sigma when accounting for cosmic variance. We find that LIRGs at z similar to 1 are consistent with being the direct descendants of Lyman Break Galaxies and UV-selected galaxies at z similar to 2- 3, both in term of number densities and clustering properties, which would suggest long lasting star-formation activity in galaxies over cosmological timescales. The local descendants of z similar to 0.5-1 star forming galaxies are not luminous IR galaxies but are more likely to be normal, L < L, ellipticals and bright spirals. C1 Osservatorio Astron Bologna, Ist Nazl Astrofis, INAF, I-40127 Bologna, Italy. Univ Paris Diderot, CNRS, CEA, Lab AIM,DSM, F-91191 Gif Sur Yvette, France. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Max Planck Inst Astrophys, D-85748 Garching, Germany. CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. Osserv Astron Trieste, Ist Nazl Astrofis, INAF, I-34131 Trieste, Italy. RP Gilli, R (reprint author), Osservatorio Astron Bologna, Ist Nazl Astrofis, INAF, Via Ranzani 1, I-40127 Bologna, Italy. EM roberto.gilli@oabo.inaf.it RI Daddi, Emanuele/D-1649-2012; Gilli, Roberto/P-1110-2015 OI Daddi, Emanuele/0000-0002-3331-9590; Gilli, Roberto/0000-0001-8121-6177 NR 87 TC 26 Z9 26 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 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 2007 VL 475 IS 1 BP 83 EP 99 DI 10.1051/0004-6361:20077506 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224WX UT WOS:000250480100008 ER PT J AU Turner, TJ Miller, L Reeves, JN Kraemer, SB AF Turner, T. J. Miller, L. Reeves, J. N. Kraemer, S. B. TI The variable X-ray spectrum of Markarian 766 - II. Time-resolved spectroscopy SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : Seyfert; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; BLACK-HOLE; XMM-NEWTON; SEYFERT-GALAXIES; COLD MATTER; IRON; REFLECTION; MCG-6-30-15; EMISSION; PROFILE AB Context. The variable X-ray spectra of AGN systematically show steep power-law high states and hard-spectrum low states. The hard, low state has previously been found to be a component with only weak variability. The origin of this component and the relative importance of effects such as absorption and relativistic blurring are currently not clear. Aims. In a follow-up of previous principal components analysis we aim to determine the relative importance of scattering and absorption e. ects on the time-varying X-ray spectrum of the narrow-line Seyfert 1 galaxy Mrk 766. Methods. Time-resolved spectroscopy, slicing XMM and Suzaku data down to 25 ks elements is used to investigate whether absorption or scattering components dominate the spectral variations in Mrk 766. Results. Time-resolved spectroscopy confirms that spectral variability in Mrk 766 can be explained by either of two interpretations of principal components analysis. Detailed investigation confirm rapid changes in the relative strengths of scattered and direct emission or rapid changes in absorber covering fraction provide good explanations of most of the spectral variability. However, a strong correlation between the 6.97 keV absorption line and primary continuum together with rapid opacity changes show that variations in a complex and multi- layered absorber, most likely a disk wind, are the dominant source of spectral variability in Mrk 766. C1 Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. Univ Oxford, Dept Phys, Oxford OW1 3RH, England. Keele Univ, Sch Phys & Geograph Sci, Astrophys Grp, Keele ST5 5BG, Staffs, England. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Turner, TJ (reprint author), Univ Maryland Baltimore Cty, Dept Phys, 1000 Hilltop Circle, Baltimore, MD 21250 USA. EM turner@milkyway.gsfc.nasa.gov RI XRAY, SUZAKU/A-1808-2009 NR 26 TC 49 Z9 49 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 NOV PY 2007 VL 475 IS 1 BP 121 EP + DI 10.1051/0004-6361:20077947 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224WX UT WOS:000250480100012 ER PT J AU Butters, OW Barlow, EJ Norton, AJ Mukai, K AF Butters, O. W. Barlow, E. J. Norton, A. J. Mukai, K. TI RXTE confirmation of the intermediate polar status of Swift J0732.5-1331 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : binaries : general; stars : novae; cataclysmic variables; stars : individual : Swift J0732.5-1331; X-rays : binaries ID MAGNETIC CATACLYSMIC VARIABLES AB Aims. We intend to establish the X-ray properties of Swift J0732.5-1331 and therefore confirm its status as an intermediate polar. Methods. We analysed 36 240 s of X-ray data from RXTE. Frequency analysis was used to constrain temporal variations and spectral analysis used to characterise the emission and absorption properties. Results. The X-ray spin period is confirmed to be 512.4(3) s with a strong first harmonic. No modulation is detected at the candidate orbital period of 5.6 h, but a coherent modulation is present at the candidate 11.3 h period. The spectrum is consistent with a 37 keV bremsstrahlung continuum with an iron line at 6.4 keV absorbed by an equivalent hydrogen column density of around 1022 atoms cm(-2). Conclusions. Swift J0732-1331 is confirmed to be an intermediate polar. C1 Open Univ, Dept Phys & Astron, Milton Keynes MK7 6AA, Bucks, England. NASA, Goddard Space Flight Ctr, CRESST, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. RP Butters, OW (reprint author), Open Univ, Dept Phys & Astron, Walton Hall, Milton Keynes MK7 6AA, Bucks, England. EM o.w.butters@open.ac.uk OI Norton, Andrew/0000-0001-7619-8269; Butters, Olly/0000-0003-0354-8461 NR 12 TC 11 Z9 11 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 NOV PY 2007 VL 475 IS 2 BP L29 EP L32 DI 10.1051/0004-6361:20078700 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 230VH UT WOS:000250903700006 ER PT J AU Moehler, S Dreizler, S Lanz, T Bono, G Sweigart, AV Calamida, A Monelli, M Nonino, M AF Moehler, S. Dreizler, S. Lanz, T. Bono, G. Sweigart, A. V. Calamida, A. Monelli, M. Nonino, M. TI The hottest horizontal-branch stars in omega Centauri. Late hot flasher vs. helium enrichment SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : horizontal-branch; stars : evolution; techniques : spectroscopic; Galaxy : globular clusters : individual : omega Centauri ID BLANKETED MODEL ATMOSPHERES; DWARF COOLING CURVE; SUBDWARF-B-STARS; BLUE HOOK STARS; GLOBULAR-CLUSTERS; MAIN-SEQUENCE; WHITE-DWARF; SPECTROSCOPIC ANALYSES; PHYSICAL PARAMETERS; STELLAR POPULATION AB Context. UV observations of some massive globular clusters have revealed a significant population of very hot stars below the hot end of the horizontal branch (HB), the so-called blue hook stars. This feature might be explained either as a result of the late hot flasher scenario where stars experience the helium flash while on the white dwarf cooling curve or by the progeny of the helium-enriched sub-population recently postulated to exist in some clusters. Previous spectroscopic analyses of blue hook stars in omega Cen and NGC 2808 support the late hot flasher scenario, but the stars contain much less helium than expected and the predicted C, N enrichment could not be verified. Aims. We compare observed effective temperatures, surface gravities, and abundances of He, C, and N of blue hook and canonical extreme horizontal branch (EHB) star candidates to the predictions of the two scenarios. Methods. Moderately high resolution spectra of stars at the hot end of the blue HB in the globular cluster. Cen were analysed for atmospheric parameters and abundances using LTE and non-LTE model atmospheres. Results. In the temperature range 30 000 K to 50 000 K we find that 35% of our stars are helium-poor (log (nHe)/(nH) < -2), 51% have solar helium abundance within a factor of 3 (- 1.5 less than or similar to log (nHe)/(nH) less than or similar to -0.5) and 14% are helium-rich (log (nHe)/(nH) > -0.4). We also find carbon enrichment strongly correlated with helium enrichment, with a maximum carbon enrichment of 3% by mass. Conclusions. At least 14% of the hottest HB stars in. Cen show helium abundances well above the highest predictions from the helium enrichment scenario (Y = 0.42 corresponding to log (nHe)/(nH) approximate to -0.74). In addition, the most helium-rich stars show strong carbon enrichment, as predicted by the late hot flasher scenario. We conclude that the helium-rich HB stars in. Cen cannot be explained solely by the helium-enrichment scenario invoked to explain the blue main sequence. C1 European So Observ, D-85748 Garching, Germany. Univ Gottingen, Inst Astrophys, D-37077 Gottingen, Germany. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. INAF Rome Astron Observ, I-00040 Monte Porzio Catone, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Astrofis Canarias, Tenerife 38200, Spain. INAF Trieste Astron Observ, I-40131 Trieste, Italy. RP Moehler, S (reprint author), European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany. EM smoehler@eso.org; dreizler@astro.physik.uni-goettingen.de; lanz@astro.umd.edu; bono@mporzio.astro.it; Allen.V.Sweigart@nasa.gov; calamida@mporzio.astro.it; monelli@iac.es; nonino@ts.astro.it NR 32 TC 30 Z9 30 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 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 2007 VL 475 IS 2 BP L5 EP L8 DI 10.1051/0004-6361:20078509 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 230VH UT WOS:000250903700001 ER PT J AU Esposito, P Caraveo, PA Pellizzoni, A De Luca, A Gehrels, N Marelli, MA AF Esposito, P. Caraveo, P. A. Pellizzoni, A. De Luca, A. Gehrels, N. Marelli, M. A. TI Swift/XRT monitoring of five orbital cycles of LS I+61 degrees 303 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE X-rays : individual : LS I+61 degrees 303; x-rays : binaries ID GAMMA-RAY SOURCES; XMM-NEWTON OBSERVATIONS; X-RAY; TRANSIENT A0538-66; H-ALPHA; MICROQUASAR LS-I+61-303; STAR LSI+61-DEGREES-303; I+61 303; COS-B; BINARY AB Context. LS I + 61 degrees 303 is one of the most interesting high-mass X-ray binaries owing to its spatially resolved radio emission and its TeV emission, generally attributed to non-thermal particles in an accretion-powered relativistic jet or in the termination shock of the relativistic wind of a young pulsar. Also, the nature of the compact object is still debated. Only LS 5039 and PSRB1259-63 ( which hosts a non-accreting millisecond pulsar) have similar characteristics. Aims. We study the X-ray emission from LS I + 61 degrees 303 covering both short-term and orbital variability. We also investigate the source spectral properties in the soft X-ray (0.3-10 keV) energy range. Methods. Twenty-five snapshot observations of LS I + 6 degrees. 303 were collected in 2006 with the XRT instrument on-board the Swift satellite over a period of four months, corresponding to about five orbital cycles. Since individual data sets have too few counts for a meaningful spectral analysis, we extracted a cumulative spectrum. Results. The count rate folded at the orbital phase shows a clear modulation pattern at the 26.5 days period and suggests that the X-ray peak occurs around phase 0.65. Moreover, the X-ray emission appears to be variable on a timescale of similar to 1 ks. The cumulative spectrum is well described by an absorbed power-law model, with hydrogen column density N-H = (5.7 +/- 0.3) x 10(21) cm(-2) and photon index Gamma = 1.78 +/- 0.05. No accretion disk signatures, such as an iron line, are found in the spectrum. C1 Univ Pavia, Dipartimento Fis Nucl & Teor, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. INAF Ist Astrofis Spaziale & Fis Cosm Milano, I-20133 Milan, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Esposito, P (reprint author), Univ Pavia, Dipartimento Fis Nucl & Teor, Via Bassi 6, I-27100 Pavia, Italy. EM paoloesp@iasf-milano.inaf.it RI Gehrels, Neil/D-2971-2012; OI Pellizzoni, Alberto Paolo/0000-0002-4590-0040; Caraveo, Patrizia/0000-0003-2478-8018; Esposito, Paolo/0000-0003-4849-5092 NR 46 TC 23 Z9 23 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 NOV PY 2007 VL 474 IS 2 BP 575 EP 578 DI 10.1051/0004-6361:20078334 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219SW UT WOS:000250106100029 ER PT J AU Babic, A Miller, L Jarvis, MJ Turner, TJ Alexander, DM Croom, SM AF Babic, A. Miller, L. Jarvis, M. J. Turner, T. J. Alexander, D. M. Croom, S. M. TI Low accretion rates at the AGN cosmic downsizing epoch SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE accretion; accretion disks; galaxies : active ID DEEP FIELD-SOUTH; BLACK-HOLE MASS; ACTIVE GALACTIC NUCLEI; RAY LUMINOSITY FUNCTION; EARLY-TYPE GALAXIES; ESO IMAGING SURVEY; DIGITAL SKY SURVEY; X-RAY; PHOTOMETRIC REDSHIFTS; DEPENDENT EVOLUTION AB Context. X-ray surveys of Active Galactic Nuclei (AGN) indicate "cosmic downsizing", with the comoving number density of high-luminosity objects peaking at higher redshifts (z similar to 2) than low-luminosity AGN (z < 1). Aims. We test whether downsizing is caused by activity shifting towards low-mass black holes accreting at near-Eddington rates, or by a change in the average rate of accretion onto supermassive black holes. We estimate the black hole masses and Eddington ratios of an X-ray selected sample of AGN in the Chandra Deep Field South at z < 1, probing the epoch where AGN cosmic downsizing has been reported. Methods. Black hole masses are estimated both from host galaxy stellar masses, which are estimated from fitting to published optical and near-infrared photometry, and from near-infrared luminosities, applying established correlations between black hole mass and host galaxy properties. Both methods give consistent results. Comparison and calibration of possible redshift- dependent effects is also made using published faint host galaxy velocity dispersion measurements. Results. The Eddington ratios in our sample span the range similar to 10(-5)-1, with median log(L-bol/L-Edd) = -2.87, and with typical black hole masses M-BH similar to 10(8) M circle dot. The broad distribution of Eddington ratios is consistent with that expected for AGN samples at low and moderate luminosity. We find no evidence that the CDF-S AGN population is dominated by low-mass black holes accreting at near-Eddington ratios and the results suggest that diminishing accretion rates onto average-sized black holes are responsible for the reported AGN downsizing at redshifts below unity. C1 Univ Oxford, Dept Phys, Oxford OX1 3RH, England. Univ Hertfordshire, STRI, Ctr Astrophys Res, Hatfield AL10 9AB, Herts, England. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. Univ Durham, Dept Phys, Durham DH1 3LE, England. Univ Sydney, Sch Phys A28, Sydney, NSW 2006, Australia. RP Babic, A (reprint author), Univ Oxford, Dept Phys, Denys Wilkinson Bldg,Keble Rd, Oxford OX1 3RH, England. EM ababic@astro.ox.ac.uk RI Babic, Ana/B-9599-2014; OI Babic, Ana/0000-0001-9549-9710; Alexander, David/0000-0002-5896-6313 NR 56 TC 49 Z9 49 U1 0 U2 4 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 NOV PY 2007 VL 474 IS 3 BP 755 EP 762 DI 10.1051/0004-6361:20078286 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224JS UT WOS:000250443900011 ER PT J AU Stratta, G D'Avanzo, P Piranomonte, S Cutini, S Preger, B Perri, M Conciatore, ML Covino, S Stella, L Guetta, D Marshall, FE Holland, ST Stamatikos, M Guidorzi, C Mangano, V Antonelli, LA Burrows, D Campana, S Capalbi, M Chincarini, G Cusumano, G D'Elia, V Evans, PA Fiore, F Fugazza, D Giommi, P Osborne, JP La Parola, V Mineo, T Moretti, A Page, KL Romano, P Tagliaferri, G AF Stratta, G. D'Avanzo, P. Piranomonte, S. Cutini, S. Preger, B. Perri, M. Conciatore, M. L. Covino, S. Stella, L. Guetta, D. Marshall, F. E. Holland, S. T. Stamatikos, M. Guidorzi, C. Mangano, V. Antonelli, L. A. Burrows, D. Campana, S. Capalbi, M. Chincarini, G. Cusumano, G. D'Elia, V. Evans, P. A. Fiore, F. Fugazza, D. Giommi, P. Osborne, J. P. La Parola, V. Mineo, T. Moretti, A. Page, K. L. Romano, P. Tagliaferri, G. TI A study of the prompt and afterglow emission of the short GRB 061201 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts ID GAMMA-RAY BURSTS; STAR-FORMATION; HOST GALAXY; JET BREAKS; SWIFT; TELESCOPE; GRB-050724; ENERGETICS AB Context. Our knowledge of the intrinsic properties of short duration Gamma-Ray Bursts has relied, so far, only upon a few cases for which the estimate of the distance and an extended, multiwavelength monitoring of the afterglow have been obtained. Aims. We carried out multiwavelength observations of the short GRB 061201 aimed at estimating its distance and studying its properties. Methods. We performed a spectral and timing analysis of the prompt and afterglow emission and discuss the results in the context of the standard fireball model. Results. A clear temporal break was observed in the X-ray light curve about 40 min after the burst trigger. We find that the spectral and timing behaviour of the X-ray afterglow is consistent with a jet origin of the observed break, although the optical data can not definitively confirm this and other scenarios are possible. No underlying host galaxy down to R similar to 26 mag was found after fading of the optical afterglow. Thus, no secure redshift could be measured for this burst. The nearest galaxy is at z = 0.111 and shows evidence of star formation activity. We discuss the association of GRB 061201 with this galaxy and with the ACO S 995 galaxy cluster, from which the source is at an angular distance of 17" and 8.5', respectively. We also test the association with a possible undetected, positionally consistent galaxy at z similar to 1. In all these cases, in the jet interpretation, we find a jet opening angle of 1-2 degrees. C1 ASI, Sci Data Ctr, I-00044 Frascati, Italy. Univ Insubria, Dipartimento Matemat & Fis, I-22100 Como, Italy. INAF, Osservatorio Astron Brera, I-23807 Merate, Italy. INAF, Osservatorio Astron Roma, I-00040 Monte Porzio Catone, Italy. Univ Perugia, Dipartimento Fis, I-06123 Perugia, Italy. Univ Roma La Sapienza, I-00185 Rome, Italy. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. GSFC, NASA, Astrophys Sci Div, Greenbelt, MD 20770 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. Univ Milan, I-20126 Milan, Italy. INAF, Inst Astrofis Spaziale & Fis Cosm, Sez Palermo, I-90146 Palermo, Italy. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. RP Stratta, G (reprint author), ASI, Sci Data Ctr, Via Galiaei, I-00044 Frascati, Italy. EM giulia.stratta@asdc.asi.it RI Stratta, Maria Giuliana/L-3045-2016; OI Fiore, Fabrizio/0000-0002-4031-4157; giommi, paolo/0000-0002-2265-5003; D'Elia, Valerio/0000-0002-7320-5862; Cusumano, Giancarlo/0000-0002-8151-1990; moretti, alberto/0000-0002-9770-0315; Stratta, Maria Giuliana/0000-0003-1055-7980; guetta, dafne/0000-0002-7349-1109; Mineo, Teresa/0000-0002-4931-8445; Perri, Matteo/0000-0003-3613-4409; La Parola, Valentina/0000-0002-8087-6488; Covino, Stefano/0000-0001-9078-5507; Cutini, Sara/0000-0002-1271-2924; Tagliaferri, Gianpiero/0000-0003-0121-0723 NR 53 TC 38 Z9 38 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 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 2007 VL 474 IS 3 BP 827 EP 835 DI 10.1051/0004-6361:20078006 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224JS UT WOS:000250443900018 ER PT J AU Ruiz-Velasco, AE Swan, H Troja, E Malesani, D Fynbo, JPU Starling, RLC Xu, D Aharonian, F Akerlof, C Andersen, MI Ashley, MCB Barthelmy, SD Bersier, D Ceron, JMC Castro-Tirado, AJ Gehrels, N Goegus, E Gorosabel, J Guidorzi, C Guver, T Hjorth, J Horns, D Huang, KY Jakobsson, P Jensen, BL Kiziloglu, U Kouveliotou, C Krimm, HA Ledoux, C Levan, AJ Marsh, T McKay, T Melandri, A Milvang-Jensen, B Mundell, CG O'Brien, PT Ozel, M Phillips, A Quimby, R Rowell, G Rujopakarn, W Rykoff, ES Schaefer, BE Sollerman, J Tanvir, NR Thone, CC Urata, Y Vestrand, WT Vreeswijk, PM Watson, D Wheeler, JC Wijers, RAMJ Wren, J Yost, SA Yuan, F Zhai, M Zheng, WK AF Ruiz-Velasco, A. E. Swan, H. Troja, E. Malesani, D. Fynbo, J. P. U. Starling, R. L. C. Xu, D. Aharonian, F. Akerlof, C. Andersen, M. I. Ashley, M. C. B. Barthelmy, S. D. Bersier, D. Ceron, J. M. Castro Castro-Tirado, A. J. Gehrels, N. Goegues, E. Gorosabel, J. Guidorzi, C. Guever, T. Hjorth, J. Horns, D. Huang, K. Y. Jakobsson, P. Jensen, B. L. Kiziloglu, Ue. Kouveliotou, C. Krimm, H. A. Ledoux, C. Levan, A. J. Marsh, T. McKay, T. Melandri, A. Milvang-Jensen, B. Mundell, C. G. O'Brien, P. T. Oezel, M. Phillips, A. Quimby, R. Rowell, G. Rujopakarn, W. Rykoff, E. S. Schaefer, B. E. Sollerman, J. Tanvir, N. R. Thoene, C. C. Urata, Y. Vestrand, W. T. Vreeswijk, P. M. Watson, D. Wheeler, J. C. Wijers, R. A. M. J. Wren, J. Yost, S. A. Yuan, F. Zhai, M. Zheng, W. K. TI Detection of GRB 060927 at z=5.47: Implications for the use of gamma-ray bursts as probes of the end of the dark ages SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; gamma rays : bursts (GRB 060927) ID HOST GALAXIES; LIGHT-CURVE; THEORETICAL IMPLICATIONS; COSMIC REIONIZATION; GRB AFTERGLOWS; COLUMN DENSITY; MILKY-WAY; REDSHIFT; SWIFT; EVOLUTION AB We report on follow-up observations of the gamma-ray burst GRB 060927 using the robotic ROTSE-IIIa telescope and a suite of larger aperture ground-based telescopes. An optical afterglow was detected 20 s after the burst, the earliest rest-frame detection of optical emission from any GRB. Spectroscopy performed with the VLT about 13 hr after the trigger shows a continuumbreak at lambda approximate to 8070 angstrom, produced by neutral hydrogen absorption at z approximate to 5.6. We also detect an absorption line at 8158 angstrom, which we interpret as Si II lambda 1260 at z = 5. 467. Hence, GRB 060927 is the second most distant GRB with a spectroscopically measured redshift. The shape of the red wing of the spectral break can be fitted by a damped Ly alpha profile with a column density with log (N-H/cm(-2)) = 22-50 +/- 0.15. We discuss the implications of thiswork for the use ofGRBs as probes of the end of the dark ages and draw threemain conclusions: (1) GRB afterglows originating from z less than or similar to 6 should be relatively easy to detect from the ground, but rapid near-infrared monitoring is necessary to ensure that they are found; (2) the presence of large H I column densities in some GRB host galaxies at z > 5 makes the use of GRBs to probe the reionization epoch via spectroscopy of the red damping wing challenging; and ( 3) GRBs appear crucial to locate typical star-forming galaxies at z > 5, and therefore the type of galaxies responsible for the reionization of the universe. C1 Univ Copenhagen, Neil Bohr Inst, Dark Cosmol Ctr, DK-2100 Copenhagen, Denmark. Univ Guanajuato, Dept Astron, Guanajuato 36000, Mexico. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. INAF Ist Astrofis Spaz & Fis Cosm Sez Palermo, I-90146 Palermo, Italy. Univ Palermo, Sez Astron, Dipartimento Sci Fis & Astron, I-90134 Palermo, Italy. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. Inst Astrophys, D-14482 Potsdam, Germany. Univ New S Wales, Sch Phys, Dept Astrophys & Opt, Sydney, NSW 2052, Australia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. IAA CSIC, E-18080 Granada, Spain. Sabanci Univ, TR-34956 Istanbul, Turkey. INAF Osservatorio Astron Brera, I-23807 Merate, Italy. Istanbul Univ, Fac Sci, Dept Astron & Space Sci, TR-34119 Istanbul, Turkey. Natl Cent Univ, Inst Astron, Chungli 32054, Taiwan. Univ Hertfordshire, Ctr Astrophys Res, Hatfield AL10 9AB, Herts, England. Middle E Tech Univ, TR-06531 Ankara, Turkey. NASA Marshall Space Flight Ctr, NSSTC, Huntsville, AL USA. Univ Space Res Assoc, Columbia, MD 21044 USA. European So Observ, Santiago 19, Chile. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Canakkale Onsekiz Mart Univ, TR-17020 Canakkale, Turkey. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Saitama Univ, Dept Phys, Sakura, Saitama 3388570, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China. RP Ruiz-Velasco, AE (reprint author), Univ Copenhagen, Neil Bohr Inst, Dark Cosmol Ctr, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark. RI Guver, Tolga/C-1408-2011; Horns, Dieter/C-9727-2011; Barthelmy, Scott/D-2943-2012; Gehrels, Neil/D-2971-2012; Rujopakarn, Wiphu/E-7849-2012; McKay, Timothy/C-1501-2009; Guver, Tolga/B-1039-2014; Watson, Darach/E-4521-2015; Jensen, Brian Lindgren/E-1275-2015; Jakobsson, Pall/L-9950-2015; OI McKay, Timothy/0000-0001-9036-6150; Guver, Tolga/0000-0002-3531-9842; Watson, Darach/0000-0002-4465-8264; Jensen, Brian Lindgren/0000-0002-0906-9771; Jakobsson, Pall/0000-0002-9404-5650; Castro-Tirado, A. J./0000-0003-2999-3563; Wijers, Ralph/0000-0002-3101-1808; Sollerman, Jesper/0000-0003-1546-6615; Thone, Christina/0000-0002-7978-7648; Rujopakarn, Wiphu/0000-0002-0303-499X; Flewelling, Heather/0000-0002-1050-4056; Rowell, Gavin/0000-0002-9516-1581 NR 84 TC 53 Z9 53 U1 0 U2 8 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 1 PY 2007 VL 669 IS 1 BP 1 EP 9 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224XB UT WOS:000250480600001 ER PT J AU Fukumura, K Kazanas, D AF Fukumura, Keigo Kazanas, Demosthenes TI Mass outflows from dissipative shocks in hot accretion flows SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion; accretion disks; black hole physics; galaxies : jets; hydrodynamics; shock waves ID ACTIVE GALACTIC NUCLEI; KERR BLACK-HOLE; RELATIVISTIC OUTFLOWS; COMPACT OBJECTS; GLOBAL-SOLUTIONS; JET FORMATION; DISKS; GEOMETRY; PLASMA; MODEL AB We consider stationary, axisymmetric hydrodynamic accretion flows in Kerr geometry. As a plausible means of efficiently separating a small population of nonthermal particles from the bulk accretion flows, we investigate the formation of standing dissipative shocks, i.e., shocks at which fraction of the energy, angular momentum, and mass fluxes do not participate in the shock transition of the flow that accretes onto the compact object but are lost into collimated (jets) or uncollimated (winds) outflows. The mass-loss fraction (at a shock front) is found to vary over a wide range (0% -95%), depending on flow's angular momentum and energy. On the other hand, the associated energy-loss fraction appears to be relatively low (less than or similar to 1%) for a flow onto a nonrotating black hole case, whereas the fraction could be an order of magnitude higher (less than or similar to 10%) for a flow onto a rapidly rotating black hole. By estimating the escape velocity of the outflowing particles with a mass-accretion rate relevant for typical active galactic nuclei, we find that nearly 10% of the accreting mass could escape to form an outflow in a disk around a nonrotating black hole, while as much as 50% of the matter may contribute to outflows in a disk around a rapidly rotating black hole. In the context of disk-jet paradigm, our model suggests that shock-driven outflows from accretion can occur in regions not too far from a central engine. Our results imply that a shock front under some conditions could serve as a plausible site where (nonthermal) seed particles of the outflows (jets/winds) are efficiently decoupled from bulk accretion. C1 NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. RP Fukumura, K (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Code 663, Greenbelt, MD 20771 USA. EM fukumura@milkyway.gsfc.nasa.gov; demos.kazanas-1@nasa.gov NR 39 TC 8 Z9 8 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 1 PY 2007 VL 669 IS 1 BP 85 EP 95 DI 10.1086/521578 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224XB UT WOS:000250480600008 ER PT J AU Jensen, AG Snow, TP AF Jensen, Adam G. Snow, Theodore P. TI The variation of magnesium depletion with line-of-sight conditions SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ultraviolet : ISM ID ULTRAVIOLET-SPECTROSCOPIC-EXPLORER; INTERSTELLAR ABSORPTION-LINES; TRANSLUCENT CLOUDS; GALACTIC DISK; ABUNDANCES; EXTINCTION; ELEMENTS; OXYGEN; HOMOGENEITY; DENSITIES AB In this paper we report on the gas-phase abundance of singly ionized magnesium ( Mg II) in 44 lines of sight, using data from the Hubble Space Telescope ( HST). We measure Mg II column densities by analyzing medium- and high-resolution archival Space Telescope Imaging Spectrograph ( STIS) spectra of the 1240 angstrom doublet of Mg II. We find that Mg II depletion is correlated with many line-of-sight parameters [ e. g.,f ( H-2), EB-V, EB-V/r, A(V), and A(V)/(r)] in addition to the well-known correlation with < nH >. These parameters should be more directly related to dust content and thus have more physical significance with regard to the depletion of elements such as magnesium. We examine the significance of these additional correlations as compared to the known correlation between Mg II depletion and < nH >. While none of the correlations are better predictors of Mg II depletion than < nH >, some are statistically significant even assuming fixed < nH >. We discuss the ranges over which these correlations are valid, their strength at fixed < nH >, and physical interpretations. C1 Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. RP Jensen, AG (reprint author), NASA, Goddard Space Flight Ctr, Code 665, Greenbelt, MD 20771 USA. EM adam.jensen@colorado.edu; tsnow@casa.colorado.edu NR 39 TC 11 Z9 11 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 1 PY 2007 VL 669 IS 1 BP 401 EP 411 DI 10.1086/521420 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224XB UT WOS:000250480600030 ER PT J AU Imai, H Sahai, R Morris, M AF Imai, Hiroshi Sahai, Raghvendra Morris, Mark TI The spatio-kinematical structure and distance of the preplanetary nebula IRAS 19134+2131 SO ASTROPHYSICAL JOURNAL LA English DT Article DE masers; stars : AGB and post-AGB; stars : individual ( IRAS 19134+2131); stars : kinematics; stars : mass loss; stars : winds; outflows ID WATER-MASER EMISSION; POST-AGB STARS; OH IR STARS; H2O MASERS; PLANETARY-NEBULAE; PROTOPLANETARY NEBULA; COLLIMATED JET; MOLECULAR GAS; GIANT BRANCH; SIO MASER AB Using the Very Long Baseline Array at six epochs, we have observed H2O maser emission in the preplanetary nebula IRAS 19134+2131 (I19134), in which the H2O maser spectrum has two groups of emission features separated in radial velocity by similar to 100 km s(-1). We also obtained optical images of I19134 with the Hubble Space Telescope to locate the bipolar reflection nebula in this source for the first time. The spatio-kinematical structure of the H2O masers indicates the existence of a fast, collimated (precessing) flow having a projected extent of similar to 140 mas and an expansion rate of similar to 1.9 mas yr(-1) on the sky plane, which gives a dynamical age of only similar to 40 yr. The two detected optical lobes are also separated by similar to 150 mas in almost the same direction as that of the collimated flow. The good agreement between the extent and orientation of the H2O maser outflow and optical lobes suggests that the lobes have been recently formed along the collimated fast flow. Thus, the circumstellar envelope around the evolved star has apparently been penetrated by the fast flow and has been cleared for the emergence of the starlight in the directions of the fast flow. The positions of all of the detected maser features have been measured with respect to the extragalactic reference source J1925+2106 over one year. Therefore, we analyzed maser feature motions that consist of the combination of an annual parallax, a secular motion following Galactic rotation, and the intrinsic motions within the flow. We obtain an annual-parallax distance to I19134 of D = 8.0(-0.7)(+0.9) kpc and estimate its location in the Galaxy to be (R, theta, z) = (7.4(-0.3)(+0.4) kpc; 62 degrees +/- 5 degrees, 0.65(-0.06)(+0.07) kpc). From the mean motion of the blueshifted and redshifted clusters of maser features, we estimate the three-dimensional (3D) secular motion of I19134 to be (V-R, V-theta, V-z) = (3(-46)(+53), 125(-28)(+20), 8(-39)(+48)) km s(-1). From the height from the Galactic plane, z, and the velocity component perpendicular to the Galactic plane, V-z, we estimate a rough upper limit of similar to 9 M-circle dot to the stellar mass of I19134's progenitor. C1 Kagoshima Univ, Fac Sci, Dept Phys, Kagoshima 8900065, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Imai, H (reprint author), Kagoshima Univ, Fac Sci, Dept Phys, 1-21-35 Korimoto, Kagoshima 8900065, Japan. EM hiroimai@sci.kagoshima-u.ac.jp NR 41 TC 35 Z9 35 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 NOV 1 PY 2007 VL 669 IS 1 BP 424 EP 434 DI 10.1086/521350 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224XB UT WOS:000250480600032 ER PT J AU Pandian, JD Goldsmith, PF AF Pandian, Jagadheep D. Goldsmith, Paul F. TI The arecibo methanol maser galactic plane survey. II. Statistical and multiwavelength counterpart analysis SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxy : structure; HII regions; infrared : ISM; masers; radio continuum : ISM; stars : formation; surveys ID STAR-FORMATION; GHZ; POPULATION; CATALOGS; GALAXY; MILKY; DISK AB We present an analysis of the properties of the 6.7 GHz methanol maser sample detected in the Arecibo Methanol Maser Galactic Plane Survey. The distribution of the masers in the Galaxy, and statistics of their multiwavelength counterparts is consistent with the hypothesis of 6.7 GHz maser emission being associated with massive young stellar objects. Using the detection statistics of our survey, we estimate the minimum number of methanol masers in the Galaxy to be 1275. The l-v diagram of the sample shows the tangent point of the Carina-Sagittarius spiral arm to be around 49.6 degrees, and suggests the occurrence of massive star formation along the extension of the Crux-Scutum arm. A Gaussian component analysis of the maser spectra shows the mean line width to be 0.38 km s(-1), which is more than a factor of 2 larger than what has been reported in the literature. We also find no evidence that faint methanol masers have different properties than their bright counterparts. C1 Max Planck Inst Radioastron, D-53121 Bonn, Germany. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Pandian, JD (reprint author), Max Planck Inst Radioastron, Auf Hugel 69, D-53121 Bonn, Germany. EM jpandian@mpifr-bonn.mpg.de; Paul.F.Goldsmith@jpl.nasa.gov RI Goldsmith, Paul/H-3159-2016 NR 29 TC 22 Z9 22 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 1 PY 2007 VL 669 IS 1 BP 435 EP 445 DI 10.1086/521672 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224XB UT WOS:000250480600033 ER PT J AU Bassani, L Landi, R Malizia, A Fiocchi, MT Bazzano, A Bird, AJ Dean, AJ Gehrels, N Giommi, P Ubertini, P AF Bassani, L. Landi, R. Malizia, A. Fiocchi, M. T. Bazzano, A. Bird, A. J. Dean, A. J. Gehrels, N. Giommi, P. Ubertini, P. TI IGR J22517+2218 = MG3 J225155+2217: A new gamma-ray lighthouse in the distant universe SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; quasars : individual ( IGR J22517+2218; MG3 J225155+2217) ID LOUD QUASARS; CATALOG; BLAZARS; VIEW; BEPPOSAX; END AB We report on the identification of a new soft gamma-ray source, namely, IGR J22517+2218, detected with INTEGRAL IBIS. The source, which has an observed 20-100 keV flux of similar to 4 x 10(-11) ergs cm(-2) s(-1), is spatially coincident with MG3 J225155+2217, a quasar at. The Swift XRT 0.5-10 keV continuum is flat (Gamma = 1.5) with evidence for a spectral curvature below 1-2 keV either due to intrinsic absorption (N-H = 3 +/- 2 x 10(22) cm(-2)) or to a change in slope (Delta Gamma = 0.5). X- ray observations indicate flux variability over a 6 day period that is further supported by a flux mismatch between Swift and INTEGRAL spectra. IGR J22517+2218 is radio-loud and has a flat radio spectrum; optically, it is a broad-line emitting quasar with the atypical property of hosting a narrow-line absorption system. The source spectral energy distribution is unusual compared to blazars of similar type: either it has the synchrotron peak in the X- ray/gamma-ray band (i.e., much higher than generally observed) or the Compton peak in the MeV range ( i.e., lower than typically measured). IGR J22517+2218=MG3 J225155+2217 is the second most distant blazar detected above 20 keV and a gamma-ray lighthouse shining from the edge of our universe. C1 IASF Bologna INAF, I-40129 Bologna, Italy. IASF Roma INAF, I-00133 Rome, Italy. Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. ESRIN, ASI Sci Data Ctr, I-00044 Frascati, Italy. RP Bassani, L (reprint author), IASF Bologna INAF, Via Gobetti 101, I-40129 Bologna, Italy. RI Gehrels, Neil/D-2971-2012; OI giommi, paolo/0000-0002-2265-5003; Malizia, Angela/0000-0002-6558-1163; Bassani, Loredana/0000-0003-4858-6963; Fiocchi, Mariateresa/0000-0001-5697-6019; Bazzano, Angela/0000-0002-2017-4396 NR 24 TC 21 Z9 21 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 1 PY 2007 VL 669 IS 1 BP L1 EP L4 DI 10.1086/523757 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 224XC UT WOS:000250480700001 ER PT J AU Marcy, TP Popp, PJ Gao, RS Fahey, DW Ray, EA Richard, EC Thompson, TL Atlas, EL Loewenstein, M Wofsy, SC Park, S Weinstock, EM Swartz, WH Mahoney, MJ AF Marcy, T. P. Popp, P. J. Gao, R. S. Fahey, D. W. Ray, E. A. Richard, E. C. Thompson, T. L. Atlas, E. L. Loewenstein, M. Wofsy, S. C. Park, S. Weinstock, E. M. Swartz, W. H. Mahoney, M. J. TI Measurements of trace gases in the tropical tropopause layer SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE tropical; tropopause; stratosphere; hydrochloric acid; ozone ID IN-SITU MEASUREMENTS; UPPER TROPOSPHERE; LOWER STRATOSPHERE; AIRCRAFT OBSERVATIONS; TRANSPORT; OZONE; HNO3; CLIMATOLOGY; INSTRUMENT; ATMOSPHERE AB A unique dataset of airborne in situ observations of HCl, O-3, HNO3, H2O, CO, CO2 and CH3Cl has been made in and near the tropical tropopause layer (TTL). A total of 16 profiles across the tropopause were obtained at latitudes between 10 degrees N and 3 degrees S from the NASA WB-57F high-altitude aircraft flying from Costa Rica. Few in situ measurements of these gases, particularly HCl and HNO3, have been reported for the TTL. The general features of the trace gas vertical profiles are consistent with the concept of the TTL as distinct from the lower troposphere and lower stratosphere. A combination of the tracer profiles and correlations with O-3 is used to show that a measurable amount of stratospheric air is mixed into this region. The HCl measurements offer an important constraint on stratospheric mixing into the TTL because once the contribution from halocarbon decomposition is quantified, the remaining HCl (> 60% in this study) must have a stratospheric source. Stratospheric HCl in the TTL brings with it a proportional amount of stratospheric O-3. Quantifying the sources Of O-3 in the TTL is important because O-3 is particularly effective as a greenhouse gas in the tropopause region. (c) 2007 Elsevier Ltd. All rights reserved. C1 Natl Ocean & Atmospher Adm, Earth Syst Res Lab, Div Chem Sci, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Harvard Univ, Natl Inst Global & Environm Change, Cambridge, MA 02138 USA. Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Marcy, TP (reprint author), 730 N 23rd St 300, Milwaukee, WI 53233 USA. EM tpmarcy@hotmail.com RI Swartz, William/A-1965-2010; Gao, Ru-Shan/H-7455-2013; Ray, Eric/D-5941-2013; Atlas, Elliot/J-8171-2015; Fahey, David/G-4499-2013; Manager, CSD Publications/B-2789-2015 OI Swartz, William/0000-0002-9172-7189; Ray, Eric/0000-0001-8727-9849; Fahey, David/0000-0003-1720-0634; NR 28 TC 22 Z9 23 U1 1 U2 22 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 NOV PY 2007 VL 41 IS 34 BP 7253 EP 7261 DI 10.1016/j.atmosenv.2007.05.032 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 231FS UT WOS:000250932500009 ER PT J AU Chen, G Huey, LG Crawford, JH Olson, JR Hutterli, MA Sjostedt, S Tanner, D Dibb, J Lefer, B Blake, N Davis, D Stohl, A AF Chen, G. Huey, L. G. Crawford, J. H. Olson, J. R. Hutterli, M. A. Sjostedt, S. Tanner, D. Dibb, J. Lefer, B. Blake, N. Davis, Douglas Stohl, A. TI An assessment of the polar HOx photochemical budget based on 2003 Summit Greenland field observations SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE polar HOx; snow emission; HOx budget; formaldehyde; hydrogen peroxide ID HYDROGEN-PEROXIDE H2O2; AIR-SNOW EXCHANGE; SOUTH-POLE; ATMOSPHERIC CHEMISTRY; BOUNDARY-LAYER; SURFACE SNOW; ICE CORES; FORMALDEHYDE; ACID; HCHO AB An interpretative modeling analysis is conducted to simulate the diurnal variations in OH and HO2 + RO2 observed at Summit, Greenland in 2003. The main goal is to assess the HOx budget and to quantify the impact of snow emissions on ambient HOx as well as on CH2O and H2O2. This analysis is based on composite diurnal profiles of HOx precursors recorded during a 3-day period (July 7-9), which were generally compatible with values reported in earlier studies. The model simulations can reproduce the observed diurnal variation in HO2 + RO2 when they are constrained by observations of H2O2 and CH2O. By contrast, model predictions of OH were about factor of 2 higher than the observed values. Modeling analysis of H2O2 suggests that its distinct diurnal variation is likely controlled by snow emissions and loss by deposition and/or scavenging. Similarly, deposition and/or scavenging sinks are needed to reproduce the observed diel profile in CH2O. This study suggests that for the Summit 2003 period snow emissions contribute similar to 25% of the total CH2O production, while photochemical oxidation of hydrocarbon appears to be the dominant source. A budget assessment of HOx radicals shows that primary production from O(D-1) + H2O and photolysis of snow emitted precursors (i.e., H2O2 and CH2O)are the largest primary HOx sources at Summit, contributing 41% and 40%, respectively. The snow contribution to the HOx budget is mostly in the form of emissions of H2O2. The dominant HO, sink involves the HO2 + HO2 reaction forming H2O2, followed by its deposition to snow. These results differ from those previously reported for the South Pole (SP), in that primary production of HOx was shown to be largely driven by both the photolysis of CH2O and H2O2 emissions (46%) with smaller contributions coming from the oxidation of CH4 and the 0(D-1) + H2O reaction (i.e., 27% each). In sharp contrast to the findings at Summit in 2003, due to the much higher levels of NOx the SP HO, sinks are dominated by HOx-NOx reactions, leading to the formation and deposition of HNO3 and HO2NO2. Thus, a comparison between SP and Summit studies suggests that snow emissions appear to play a prominent role in controlling primary HOx production in both environments. However, as regards to maintaining highly elevated levels of OH, the two environments differ substantially. At Summit the elevated rate for primary production of HOx is most important; whereas, at SP it is the rapid recycling of the more prevalent HO2 radical, through reaction with NO, back to OH that is primarily responsible. (C) 2007 Elsevier Ltd. All rights reserved. C1 [Chen, G.; Crawford, J. H.; Olson, J. R.] NASA, Langley Res Ctr, Chem & Dynam Branch, Sci Directorate, Hampton, VA 23681 USA. [Huey, L. G.; Sjostedt, S.; Tanner, D.; Davis, Douglas] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA USA. [Hutterli, M. A.] British Antarctic Survey, Div Phys Sci, Cambridge, England. [Hutterli, M. A.] Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ USA. [Dibb, J.] Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NC USA. [Lefer, B.] Univ Houston, Dept Geosci, Houston, TX USA. [Blake, N.] Univ Calif Irvine, Dept Chem, Irvine, CA USA. [Stohl, A.] Norwegian Inst Air Res, Kjeller, Norway. RP Chen, G (reprint author), NASA, Langley Res Ctr, Chem & Dynam Branch, Sci Directorate, Hampton, VA 23681 USA. EM gao.chen@nasa.gov RI Stohl, Andreas/A-7535-2008; Crawford, James/L-6632-2013; Sjostedt, Steven/B-5032-2015; Lefer, Barry/B-5417-2012 OI Stohl, Andreas/0000-0002-2524-5755; Crawford, James/0000-0002-6982-0934; Lefer, Barry/0000-0001-9520-5495 NR 35 TC 26 Z9 26 U1 0 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 NOV PY 2007 VL 41 IS 36 BP 7806 EP 7820 DI 10.1016/j.atmosenv.2007.06.014 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 243XB UT WOS:000251829500010 ER PT J AU Sud, YC Lee, DM AF Sud, Y. C. Lee, Dongmin TI Parameterization of aerosol indirect effect to complement McRAS cloud scheme and its evaluation with the 3-year ARM-SGP analyzed data for single column models SO ATMOSPHERIC RESEARCH LA English DT Article DE aerosol cloud parameterization validation GCMs ID RELAXED ARAKAWA-SCHUBERT; GLOBAL CLIMATE MODELS; PART II; STOCHASTIC CONDENSATION; GENERAL-CIRCULATION; MOIST-CONVECTION; ICE NUCLEATION; MICROPHYSICS; WATER; AUTOCONVERSION AB Microphysics of clouds with the Relaxed Arakawa-Schubert Scheme (McRAS) was upgraded for simulating the Aerosol Indirect Effects (AIE) for water clouds. The AIE comprises of i) Fountoukis and Nenes aerosol activation module for obtaining cloud condensation nuclei; ii) Seifert and Beheng algorithms for precipitation microphysics but with modified accretion constant for the coarse vertical-resolution typical of a global general circulation model (GCM); and iii) Khvorostyanov and Curry parameterization for computing the effective radius (r(e)) of cloud drops. The upgraded package, named McRAS-AC, was evaluated using the 3-year ARM-SGP Single Column Model (SCM) data. Invoking only the most dominant sulfate aerosols over the region, McRAS-AC simulated realistic annual mean and annual cycles of cloud water, cloud optical thicknesses, cloud drop number concentration, and r(e). The follow-on SCM-sensitivity simulations showed that accretion of cloud water is sensitive to i) the terminal velocity of hydrometeors produced by autoconversion and ii) cloud height increases due to in-cloud condensation heating. The impact of aerosol mass concentration on the resultant column cloud water, and bulk optical properties of clouds were assessed by using 1/8 to 8 times the average monthly aerosol mass concentration estimates of GOCART aerosol climatology. A log-linear relation between cloud-radiative forcing and aerosol-mass concentration emerged in the simulated data. (c) 2007 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Seoul Natl Univ, Sch Earth & Environm Sci, Seoul, South Korea. RP Sud, YC (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Climate & Radiat Branch, Greenbelt, MD 20771 USA. EM sud@climate.gsfc.nasa.gov NR 61 TC 9 Z9 9 U1 0 U2 5 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 NOV PY 2007 VL 86 IS 2 BP 105 EP 125 DI 10.1016/j.atmosres.2007.03.007 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 230OZ UT WOS:000250887100002 ER PT J AU Tang, XD Tao, G Joshi, SM AF Tang, Xidong Tao, Gang Joshi, Suresh M. TI Adaptive actuator failure compensation for nonlinear MIMO systems with an aircraft control application SO AUTOMATICA LA English DT Article DE actuator failure; adaptive control; backstepping; multivariable systems; nonlinear control ID RECONFIGURABLE FLIGHT CONTROL; FAULT-DIAGNOSIS; ALGORITHMS AB A direct adaptive approach is developed for control of a class of multi-input multi-output (MIMO) nonlinear systems in the presence of uncertain failures of redundant actuators. An adaptive failure compensation controller is designed which is capable of accommodating uncertainties in actuator failure time instants, values and patterns. A realistic situation is studied with fixed grouping of actuators and proportional actuation within actuator groups. The adaptive control system is analyzed, to show its desired stability and asymptotic tracking properties in the presence of actuator failure uncertainties. As an application, such an adaptive controller is used for actuator failure compensation of a twin otter aircraft longitudinal model, with design conditions verified and control structure and adaptive laws developed for a nonlinear aircraft dynamic model. The effectiveness of adaptive failure compensation is demonstrated by simulation results. (C) 2007 Elsevier Ltd. All rights reserved. C1 Univ Virginia, Dept ECE, Charlottesville, VA 22903 USA. GM R&D & Planning, Warren, MI 48090 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Tang, XD (reprint author), Univ Virginia, Dept ECE, Charlottesville, VA 22903 USA. EM xidong.tang@gni.com; gt9s@virginia.edu; s.mjoshi@larc.nasa.gov NR 26 TC 170 Z9 189 U1 1 U2 22 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0005-1098 J9 AUTOMATICA JI Automatica PD NOV PY 2007 VL 43 IS 11 BP 1869 EP 1883 DI 10.1016/j.automatica.2007.03.019 PG 15 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA 233NQ UT WOS:000251098000002 ER PT J AU Yung, PT Lester, ED Bearman, G Ponce, A AF Yung, Pun To Lester, Elizabeth D. Bearman, Greg Ponce, Adrian TI An automated front-end monitor for anthrax surveillance systems based on the rapid detection of airborne endospores SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE anthrax; Bacillus anthracis; bacterial spores; endospores; terbium; dipicolinic acid ID DIPICOLINIC ACID; BACTERIAL ENDOSPORES; BACILLUS-ANTHRACIS; SPORE DETECTION; SMOKE DETECTOR; ASSAY; BIOAEROSOLS; RESISTANCE; SUBTILIS AB A fully automated anthrax smoke detector (ASD) has been developed and tested. The ASD is intended to serve as a cost effective front-end monitor for anthrax surveillance systems. The principle of operation is based on measuring airborne endospore concentrations, where a sharp concentration increase signals an anthrax attack. The ASD features an air sampler, a thermal lysis unit, a syringe pump, a time-gated spectrometer, and endospore detection chemistry comprised of dipicolinic acid (DPA)-triggered terbium ion (Tb3+) luminescence. Anthrax attacks were simulated using aerosolized Bacillus atrophaeus spores in fumed silica, and corresponding Tb-DPA intensities were monitored as a function of time and correlated to the number of airborne endospores collected. A concentration dependence of 10(2)-10(6) spores/mg of fumed silica yielded a dynamic range of 4 orders of magnitude and a limit of detection of 16 spores/L when 250 L of air were sampled. Simulated attacks were detected in less than 15 min. C1 CALTECH, Pasadena, CA 91125 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. RP Ponce, A (reprint author), CALTECH, Pasadena, CA 91125 USA. EM Adrian.Ponce@jpl.nasa.gov NR 36 TC 16 Z9 18 U1 0 U2 6 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD NOV 1 PY 2007 VL 98 IS 4 BP 864 EP 871 DI 10.1002/bit.21466 PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 219ZD UT WOS:000250125800014 PM 17514759 ER PT J AU Brooke, S Stone, R AF Brooke, Sandra Stone, Robert TI Reproduction of deep-water hydrocorals (family Stylasteridae) from the Aleutian Islands, Alaska SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 3rd International Symposium on Deep-Sea Corals CY NOV 28-DEC 02, 2005 CL Miami, FL ID GENERIC REVISION; COELENTERATA; HYDROZOA; ECOLOGY; HISTORY; CORAL AB Previous studies in the Aleutian islands have found dense coral "gardens" dominated by hydrocorals, gorgonians, and sponges between 117 and 338 m depth, These structurally complex habitats supported a high taxonomic diversity of corals and associated fauna, but disturbance from fishing activities was observed at many of the sites. In 2003 and 2004, the submersible DELTA was used to collect samples of 11 different species of hydrocorals from deep-water sites along the Aleutian Island Archipelago. Samples of three species were also collected from shallow water (< 27 m) in 2003 using SCUBA. All samples were processed according to standard histological techniques and used to describe the reproductive traits of each species. All species studied were gonochoristic brooders with the majority of gonophores containing mature embryos or planulae. The developmental stage of gametes within a single specimen was not highly synchronized; females contained eggs as well as planulae, and males exhibited a range of gamete development. These reproductive traits indicate that hydrocorals have limited potential to recolonize disturbed areas in the Aleutian Islands. C1 [Brooke, Sandra] Oregon Inst Marine Biol, Charleston, OR USA. [Stone, Robert] Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Auk Bay Lab, Juneau, AK 99801 USA. RP Brooke, S (reprint author), Oregon Inst Marine Biol, Charleston, OR USA. EM sandra-brooke@comcast.net NR 17 TC 10 Z9 11 U1 1 U2 8 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD NOV PY 2007 VL 81 IS 3 BP 519 EP 532 PG 14 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 249BV UT WOS:000252202700016 ER PT J AU La Duc, MT Stuecker, T Venkateswaran, K AF La Duc, Myron T. Stuecker, Tara Venkateswaran, Kasthuri TI Molecular bacterial diversity and bioburden of commercial airliner cabin air SO CANADIAN JOURNAL OF MICROBIOLOGY LA English DT Article DE airline; cabin; air; pathogen; molecular; 16S rRNA; bioburden; health; ATP ID RIBOSOMAL-RNA GENES; PCR DETECTION; AIRCRAFT; ENVIRONMENTS; POPULATIONS; INFECTIONS; QUALITY; HEALTH; TRAVEL; NASAL AB Culture-independent, biomarker-targeted bacterial enumeration and identification strategies were employed to estimate total bacterial burden and diversity within the cabin air of commercial airliners. Samples from each of 4 flights on 2 commercial carriers were collected via air-impingement. The total viable microbial population ranged from below detection limits to 4.1 x 10(6) cells/m(3) of air, as assessed by the ATP assay. A gradual accumulation of microbes was observed from the time of passenger boarding through mid-flight, followed by a sharp decline in bacterial abundance and viability from the initiation of descent through landing. Representatives of the alpha-, beta-, and gamma-Proteobacteria, as well as Gram-positive bacteria, were isolated in varying abundance. Neisseria meningitidis rRNA gene sequences were retrieved in great abundance from Airline A followed by Streptococcus oralis/mitis sequences. Pseudomonas synxantha sequences dominated Airline B clone libraries, followed by those of N. meningitidis and S. oralis/mitis. The cabin air samples examined herein housed low bacterial diversity and were often dominated by a particular subset of bacteria: opportunistic pathogenic inhabitants of the human respiratory tract and oral cavity. C1 CALTECH, Jet Propuls Lab, Biotechnol & Planetary Protect Grp, Pasadena, CA 91109 USA. RP Venkateswaran, K (reprint author), CALTECH, Jet Propuls Lab, Biotechnol & Planetary Protect Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM kjvenkat@jpl.nasa.gov NR 44 TC 12 Z9 12 U1 1 U2 4 PU NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS PI OTTAWA PA BUILDING M 55, OTTAWA, ON K1A 0R6, CANADA SN 0008-4166 J9 CAN J MICROBIOL JI Can. J. Microbiol. PD NOV PY 2007 VL 53 IS 11 BP 1259 EP 1271 DI 10.1139/W07-093 PG 13 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Immunology; Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Immunology; Microbiology GA 234AU UT WOS:000251133800008 PM 18026220 ER PT J AU Hornby, GS AF Hornby, Gregory S. TI Modularity, reuse, and hierarchy: Measuring complexity by measuring structure and organization SO COMPLEXITY LA English DT Article DE design; evolutionary algorithm; evolutionary design; complexity; structure; organization ID SYSTEMS AB To develop better complexity measures, a reasonable approach is to base them on those principles of design that designers use. Modularity, reuse, and hierarchy (MR&H) have been identified by engineers as useful principles for designing complex systems, and these characteristics can be seen in Nature. Here, we develop metrics for each of MR&H, and then use them to develop several metrics of structure and organization. Further, we propose to evaluate complexity measures both empirically and on a set of abstract object-construction examples. After applying these tests to a handful of previously defined complexity measures, as well as ones we define here, we find that only two of our measures pass both sets of tests. (c) 2007 Wiley Periodicals, Inc. C1 Univ Calif Santa Cruz, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hornby, GS (reprint author), Univ Calif Santa Cruz, NASA, Ames Res Ctr, MS 269-3, Moffett Field, CA 94035 USA. EM hornby@email.arc.nasa.gov NR 26 TC 14 Z9 14 U1 0 U2 3 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 1076-2787 J9 COMPLEXITY JI Complexity PD NOV-DEC PY 2007 VL 13 IS 2 BP 50 EP 61 DI 10.1002/cplx.20202 PG 12 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA 246UC UT WOS:000252031800006 ER PT J AU Zardus, JD Balazs, GH AF Zardus, John D. Balazs, George H. TI Two previously unreported barnacles commensal with the green sea turtle, Chelonia mydas (Linnaeus, 1758), in Hawaii and a comparison of their attachment modes SO CRUSTACEANA LA English DT Article ID LARVAL DEVELOPMENT; ATLANTIC BARNACLE; STOMATOLEPAS; BALANOMORPHA; TESTUDINARIA; CIRRIPEDIA AB Two species of barnacles found living in the skin of green sea turtles, Chelonia mydas, and not previously recorded in Hawaii are reported and their attachment mechanisms compared. These findings bring to five the total number of barnacles commensal with Hawaiian sea turtles and to 50 the number of shallow-water cirripedes known in Hawaii. Identified as Stomatolepas elegans and Platylepas decorata, both species live embedded in the soft skin of the limbs, neck, and tail of their host. Stomatolepas elegans is perhaps a recent arrival in Hawaii with this being the first report of it, or any member of the genus, occurring with hawksbill turtles, Eretmochelys imbricata. We found the barnacle embeds by penetrating the epidermis of sea turtles and then anchors in connective tissue of the dermis by way of small spikes extending fromt he shell. Conversely, P. decorata invades host tissue less deeply, lacks anchoring devices, and becomes encapsulated only by epidermis. Species diagnoses were made by light and scanning electron microscopy and by comparison with other members in each genus. C1 The Citadel, Dept Biol, Charleston, SC 29409 USA. Pacific Islands Fisheries Sci Ctr, Natl Marine Fisheries Serv, NOAA, Honolulu, HI 96822 USA. RP Zardus, JD (reprint author), The Citadel, Dept Biol, 171 Moultrie St, Charleston, SC 29409 USA. EM john.zardus@citadel.edu NR 34 TC 16 Z9 17 U1 0 U2 2 PU BRILL ACADEMIC PUBLISHERS PI LEIDEN PA PLANTIJNSTRAAT 2, P O BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0011-216X J9 CRUSTACEANA JI Crustaceana PD NOV PY 2007 VL 80 IS 11 BP 1303 EP 1315 DI 10.1163/156854007782605547 PG 13 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 237WZ UT WOS:000251408400003 ER PT J AU Seeb, LW Antonovich, A Banks, AA Beacham, TD Bellinger, AR Blankenship, SM Campbell, AR Decovich, NA Garza, JC Guthrie, CM Lundrigan, TA Moran, P Narum, SR Stephenson, JJ Supernault, KJ Teel, DJ Templin, WD Wenburg, JK Young, SE Smith, CT AF Seeb, L. W. Antonovich, A. Banks, A. A. Beacham, T. D. Bellinger, A. R. Blankenship, S. M. Campbell, A. R. Decovich, N. A. Garza, J. C. Guthrie, C. M., III Lundrigan, T. A. Moran, P. Narum, S. R. Stephenson, J. J. Supernault, K. J. Teel, D. J. Templin, W. D. Wenburg, J. K. Young, S. E. Smith, C. T. TI Development of a standardized DNA database for Chinook salmon SO FISHERIES LA English DT Article ID CROSS-SPECIES AMPLIFICATION; ONCORHYNCHUS-TSHAWYTSCHA; POPULATION-STRUCTURE; PACIFIC SALMON; MICROSATELLITE LOCI; GENETIC-STRUCTURE; MARKERS; IDENTIFICATION; DIVERSITY; FISHERIES AB An international multi-laboratory project was conducted to develop a standardized DNA database for Chinook salmon (Oncorhynchus tshawytscha). This project was in response to the needs of the Chinook Technical Committee of the Pacific Salmon Commission to identify stock composition of Chinook salmon caught in fisheries during their oceanic migrations. Nine genetics laboratories identified 13 microsatellite loci that could be reproducibty assayed in each of the laboratories. To test that the loci were reproducible among laboratories, blind tests were conducted to verify scoring consistency for the nearly 500 total alleles. Once standardized, a dataset of over 16,000 Chinook salmon representing 110 putative populations was constructed ranging throughout the area of interest of the Pacific Salmon Commission from Southeast Alaska to the Sacramento River in California. The dataset differentiates the major known genetic lineages of Chinook salmon and provides a tool for genetic stock identification of samples collected from mixed fisheries. A diverse group of scientists representing the disciplines of fishery management, genetics, fishery administration, population dynamics, and sampling theory are now developing recommendations for the integration of these genetic data into ocean salmon management. C1 [Seeb, L. W.; Antonovich, A.; Lundrigan, T. A.] Univ Washington, Sch Aquat & Fisheries Sci, Seattle, WA 98195 USA. [Decovich, N. A.] Alaska Dept Fish & Game, Div Commercial Fisheries, Anchorage, AK 99518 USA. [Banks, A. A.] Oregon State Univ, Hatfield Marine Sci Ctr, Corvallis, OR 97331 USA. [Beacham, T. D.] Dept Fisheries & Oceans Pacific Biol Stn, Nanaimo, BC, Canada. [Blankenship, S. M.] Ctr Sci, Natl Marine Fisheries Serv, Washington Dept Fish & Wildlife, Santa Cruz, CA USA. [Campbell, A. R.] Eagle Fish Genet Lab, Dept Fish & Game, Eagle, CO USA. [Garza, J. C.] Fisheries Sci Ctr, Natl Marine Fisheries Serv, Santa Cruz, CA USA. [Guthrie, C. M., III] Ted Stevens Marine Res Inst, Natl Marine Fisheries Serv, Auk Bay Lab, Juneau, AK USA. [Lundrigan, T. A.] Univ Victorias Ctr Biomed Res, Victoria, BC, Canada. [Teel, D. J.] Natl Marine Fisheries Serv NW Fisheries Sci Ctr, Seattle, WA USA. [Narum, S. R.] Columbia River Inter Tribal Fish Comm, Hagerman Fish Culture Expt Stn, Idaho Falls, ID USA. [Wenburg, J. K.] US Fish & Wildlife Serv, Alaska Fish & Wildlife Res Ctr, Anchorage, AK 99503 USA. [Young, S. E.] Washington Dept Fish & Wildlife, Olympia, WA USA. [Smith, C. T.] Alaska Dept Fish & Game, Abernathy Fish Technol Ctr, Div Commercial Fisheries, US Fish & Wildlife Serv, Washington, DC USA. RP Seeb, LW (reprint author), Univ Washington, Sch Aquat & Fisheries Sci, Seattle, WA 98195 USA. EM lseeb@u.washington.edu OI Bellinger, M. Renee/0000-0001-5274-9572 NR 33 TC 95 Z9 99 U1 1 U2 23 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0363-2415 J9 FISHERIES JI Fisheries PD NOV PY 2007 VL 32 IS 11 BP 540 EP 552 DI 10.1577/1548-8446(2007)32[540:DOASDD]2.0.CO;2 PG 13 WC Fisheries SC Fisheries GA 243IC UT WOS:000251789000007 ER PT J AU Lefticariu, L Schiminelinann, A Pratt, LM Ripley, EM AF Lefticariu, Liliana Schiminelinann, Arndt Pratt, Lisa M. Ripley, Edward M. TI Oxygen isotope partitioning during oxidation of pyrite by H2O2 and its dependence on temperature SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Review ID ACID-MINE DRAINAGE; RATE-DETERMINING STEP; HABER-WEISS REACTION; HYDROGEN-PEROXIDE; MERIDIANI-PLANUM; CATALYTIC DECOMPOSITION; BACTERIAL OXIDATION; SURFACE OXIDATION; MOLECULAR-OXYGEN; GAMMA-RADIOLYSIS AB A detailed experimental study was conducted to investigate mechanisms of pyrite oxidation by determining product yields and oxygen isotopic fractionation during reactions between powdered pyrite (FeS2) with aqueous hydrogen peroxide (H2O2)Sealed silica-tube experiments utilized aliquots of pyrite that were reacted with 0.2 M H2O2 for 7 to 14 days at 4 to 150 degrees C. No volatile sulfur species were detected in any experiment. The only gaseous product recovered was elemental oxygen inferred to result from decomposition of H2O2. Aqueous sulfate (S-aq) was the only sulfur product recovered from solution. Solid hydrated ferric iron sulfates (i.e., water-soluble sulfate fraction, S.,) were recovered from all experiments. Ferric oxide (hematite) was detected only in high temperature experiments. Reactants were selected with large differences in initial delta O-18 values. The oxygen isotopic compositions of oxygen-bearing reactants and products were analyzed for each experiment. Subsequent isotopic mass-balances were used to identify sources of oxygen for reaction products and to implicate specific chemical reaction mechanisms. 6180 of water did not show detectable change during any experiment. delta O-18 of sulfate was similar for S-aq and S-ws and indicated that both H2O and H2O2 were sources of oxygen in sulfate. Low-temperature experiments suggest that H2O-derived oxygen was incorporated into sulfate via Fe3+ oxidation, whereas H2O2-derived oxygen was incorporated into sulfate via oxidation by hydroxyl radicals (HO center dot). These two competing mechanisms for oxygen incorporation into sulfate express comparable influences at 25 degrees C. With increasing reaction temperatures from 4 to 100 degrees C, it appears that accelerated thermal decomposition and diminished residence time of H2O2 limit the oxygen transfer from H2O2 into sulfate and enhance the relative importance of H2O-derived oxygen for incorporation into sulfate. Notably, at temperatures between 100 and 150 degrees C there is a reversal in the lower temperature trend resulting in dominance of H2O2-derived oxygen over H2O-derived oxygen. At such high temperatures, complete thermal decomposition of H202 to water and molecular oxygen (02) occurs within minutes in mineral-blank experiments and suggests little possibility for direct oxidation of pyrite by H2O2 above 100 degrees C. We hypothesize that a Fe-O-2 mechanism is responsible for oxygenating pyrite to sulfate usingO(2) from the preceding thermal decomposition of H2O2 (c) 2007 Elsevier Ltd. All rights reserved. C1 So Illinois Univ, Dept Geol, Carbondale, IL 62901 USA. Indiana Univ, Dept Geol Sci, Bloomington, IN 47405 USA. Indiana Univ, NASA, Indiana Princeton Tennessee Astrobiol Initiat, Bloomington, IN 47405 USA. RP Lefticariu, L (reprint author), So Illinois Univ, Dept Geol, Carbondale, IL 62901 USA. EM Lefticariu@geo.siu.edu RI Lefticariu, Liliana/A-9403-2011 OI Lefticariu, Liliana/0000-0003-3413-654X NR 116 TC 21 Z9 21 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 NOV 1 PY 2007 VL 71 IS 21 BP 5072 EP 5088 DI 10.1016/j.gca.2007.08.022 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 231LM UT WOS:000250948300004 ER PT J AU Schorghofer, N Aharonson, O Gerstell, MF Tatsumi, L AF Schorghofer, N. Aharonson, O. Gerstell, M. F. Tatsumi, L. TI Three decades of slope streak activity on Mars SO ICARUS LA English DT Article DE Mars, surface; Mars, atmosphere ID ORBITER CAMERA; DUST AB Slope streaks are surficial mass movements that are abundant in the dust-covered regions of Mars. Targeting of slope streaks seen in Viking images with the Mars Orbiter Camera provides observations of slope streak dust activity over two to three decades. In all study areas, new and persisting dark slope streaks are observed. Slope streaks disappeared in one area, with persisting streaks nearby. New slope streaks are found to be systematically darker than persisting streaks, which indicates gradual fading. Far more slope streaks formed at the study sites than have faded from visibility. The rate of formation at the study sites was 0.03 new slope streaks per existing streak per Mars year. Bright slope streaks do not presently form in sudden events as dark slope streaks do. instead, bright streaks might form from old dark slope streaks, perhaps transitioning through a partially faded stage. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Hawaii, NASA Astrobiol Inst, Honolulu, HI 96822 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Hawaii, Dept Geol & Geophys, Honolulu, HI 96822 USA. RP Schorghofer, N (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. EM norbert@hawaii.edu RI Schorghofer, Norbert/A-1194-2007 NR 16 TC 17 Z9 17 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 NOV 1 PY 2007 VL 191 IS 1 BP 132 EP 140 DI 10.1016/j.icarus.2007.04.026 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400008 ER PT J AU Domokos, A Bell, JF Brown, P Lemmon, MT Suggs, R Vaubaillon, J Cooke, W AF Domokos, A. Bell, J. F., III Brown, P. Lemmon, M. T. Suggs, R. Vaubaillon, J. Cooke, W. TI Measurement of the meteoroid flux at Mars SO ICARUS LA English DT Article DE cosmic rays; image processing; instrumentation ID PERIODIC COMETS; PREDICTIONS; STREAMS AB In the fall of 2005, a dedicated meteor observing campaign was carried out by the Panoramic Camera (Pancam) onboard the Mars Exploration Rover (MER) Spirit to determine the viability of using MER cameras as meteor detectors and to obtain the first experimental estimate of the meteoroid flux at Mars. Our observing targets included both the sporadic meteoroid background and two predicted martian meteor showers: one associated with IP/Halley and a potential stream associated with 2001/R1 LONEOS. A total of 353 images covering 2.7 h of net exposure time were analyzed with no conclusive meteor detections. From these data, an upper limit to the background meteoroid flux at Mars is estimated to be <4.4 x 10(-6) meteoroids km(-2) h(-1) for meteoroids with mass larger than 4 g. For comparison, the estimated flux to this mass limit at the Earth is 10-6 meteoroids km-2 h- 1 [Grun, E., Zook, H.A., Fechtiig, H., Giese, R.H., 1985. Icarus 62, 244-272]. This result is qualitatively consistent, within error bounds, with theoretical models predicting martian fluxes of similar to 50% that at Earth for meteoroids of mass 10(-3)-10(1) g [Adolfsson, L.G., Gustafson, B.A.S., Murray, C.D., 1996. Icarus 119, 144-152]. The MER cameras, even using the most sensitive mode of operation, should expect to see on average only one coincident meteor on of order 40-150 It of total exposure time based on these same theoretical martian flux estimates. To more meaningfully constrain these flux models, a longer total integrated exposure time or more sensitive camera is needed. Our analysis also suggests that the event reported as the first martian meteor [Selsis, F., Lemmon, M.T., Vaubaillon, J., Bell, U., 2005. Nature 435, 5811 is more likely a grazing cosmic ray impact, which we show to be a major source of confusion with potential meteors in all Pancam images. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. NASA, George C Marshall Space Flight Ctr, Space Environm Team EV13, Meteoriod Environm Off, Huntsville, AL 35812 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. RP Domokos, A (reprint author), Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. EM andrea.domokos@gmail.com RI Lemmon, Mark/E-9983-2010 OI Lemmon, Mark/0000-0002-4504-5136 NR 22 TC 14 Z9 14 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 EI 1090-2643 J9 ICARUS JI Icarus PD NOV 1 PY 2007 VL 191 IS 1 BP 141 EP 150 DI 10.1016/j.icarus.2007.04.017 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400009 ER PT J AU Nimmo, F Thomas, PC Pappalardo, RT Moore, WB AF Nimmo, F. Thomas, P. C. Pappalardo, R. T. Moore, W. B. TI The global shape of Europa: Constraints on lateral shell thickness variations SO ICARUS LA English DT Article DE Jupiter, satellites; satellites, shapes; interiors; tides, solid body ID ICE SHELL; GALILEAN SATELLITES; INTERNAL STRUCTURE; IO; TOPOGRAPHY; CONVECTION; EVOLUTION; ORIGIN; STATE AB The global shape of Europa is controlled by tidal and rotational potentials and possibly by lateral variations in ice shell thickness. We use limb profiles from four Galileo images to determine the best-fit hydrostatic shape, yielding a mean radius of 1560.8 +/- 0.3 km and a radius difference a - c of 3.0 +/- 0.9 km, consistent with previous determinations and inferences from gravity observations. Adding long-wavelength topography due to proposed lateral variations in shell thickness results in poorer fits to the limb profiles. We conclude that lateral shell thickness variations and long-wavelength isostatically supported topographic variations do not exceed 7 and 0.7 km, respectively. For the range of rheologies investigated (basal viscosities from 10(14) to 10(15) Pas) the maximum permissible (conductive) shell thickness is 35 km. The relative uniformity of Europa's shell thickness is due to either a heat flux >= 7 mW m(-2) from the silicate interior, lateral ice flow at the base of the shell, or convection within the shell. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Calif Santa Cruz, Dept Earth & Planetary Sci, Santa Cruz, CA 95064 USA. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Geophys & Planetary Geosci Grp, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. RP Nimmo, F (reprint author), Univ Calif Santa Cruz, Dept Earth & Planetary Sci, 1156 High St, Santa Cruz, CA 95064 USA. EM fnimmo@es.ucsc.edu NR 29 TC 20 Z9 20 U1 1 U2 4 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 NOV 1 PY 2007 VL 191 IS 1 BP 183 EP 192 DI 10.1016/j.icarus.2007.04.021 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400013 ER PT J AU Khurana, KK Pappalardo, RT Murphy, N Denk, T AF Khurana, Krishan K. Pappalardo, Robert T. Murphy, Nate Denk, Tilmann TI The origin of Ganymede's polar caps SO ICARUS LA English DT Article DE Ganymede; satellites, surfaces; Jupiter; Jupiter, magnetosphere; Europa ID ICY GALILEAN SATELLITES; MAGNETIC-FIELD; HIGH-RESOLUTION; EUROPA; MAGNETOSPHERE; SURFACE; WATER; SPACECRAFT; PLASMA; ION AB Since their discovery in Voyager images, the origin of the bright polar caps of Ganymede has intrigued investigators. Some models attributed the polar cap formation to thermal migration of water vapor to higher latitudes, while other models implicated plasma bombardment in brightening ice. Only with the arrival of Galileo at Jupiter was it apparent that Ganymede possesses a strong internal magnetic field, which blocks most of the plasma from bombarding the satellite's equatorial region while funneling plasma onto the polar regions. This discovery provides a plausible explanation for the polar caps as related to differences in plasma-induced brightening in the polar and the equatorial regions. In this context, we analyze global color and high resolution images of Ganymede obtained by Galileo, finding a very close correspondence between the observed polar cap boundary and the open/closed field lines boundary obtained from new modeling of the magnetic field environment. This establishes a clear link between plasma bombardment and polar cap brightening. High resolution images show that bright polar terrain is segregated into bright and dark patches, suggesting sputter-induced redistribution and subsequent cold trapping of water molecules. Minor differences between the location of the open/closed field lines boundary and the observed polar cap boundary may be due to interaction of Ganymede with Jupiter's magnetosphere, and our neglect of higher-order terms in modeling Ganymede's internal field. We postulate that leading-trailing brightness differences in Ganymede's low-latitude surface are due to enhanced plasma flux onto the leading hemisphere, rather than darkening of the trailing hemisphere. In contrast to Ganymede, the entire surface of Europa is bombarded by jovian plasma, suggesting that sputter-induced redistribution of water molecules is a viable means of brightening that satellite's surface. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Free Univ Berlin, Inst Geol Wissensch, D-12249 Berlin, Germany. RP Khurana, KK (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. EM kkhurana@igpp.ucla.edu NR 47 TC 23 Z9 24 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 NOV 1 PY 2007 VL 191 IS 1 BP 193 EP 202 DI 10.1016/j.icarus.2007.04.022 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400014 ER PT J AU Paganelli, F Janssen, MA Stiles, B West, R Lorenz, RD Lunine, JI Wall, SD Callahan, P Lopes, RM Stofan, E Kirk, RL Johnson, WTK Roth, L Elachi, C AF Paganelli, F. Janssen, M. A. Stiles, B. West, R. Lorenz, R. D. Lunine, J. I. Wall, S. D. Callahan, P. Lopes, R. M. Stofan, E. Kirk, R. L. Johnson, W. T. K. Roth, L. Elachi, C. CA Radar Team TI Titan's surface from Cassini RADAR SAR and high resolution radiometry data of the first five flybys SO ICARUS LA English DT Article DE titan; radar observations; satellites, surfaces; Saturn, satellites ID DIELECTRIC-PROPERTIES; ICY SATELLITES AB The first five Titan flybys with Cassini's Synthetic Aperture RADAR (SAR) and radiometer are examined with emphasis on the calibration and interpretation of the high-resolution radiometry data acquired during the SAR mode (SAR-radiometry). Maps of the 2-cm wavelength brightness temperature are obtained coincident with the SAR swath imaging, with spatial resolution approaching 6 km. A preliminary calibration shows that brightness temperature in these maps varies from 64 to 89 K. Surface features and physical properties derived from the SAR-radiometry maps and SAR imaging are strongly correlated; in general, we find that surface features with high radar reflectivity are associated with radiometrically cold regions, while surface features with low radar reflectivity correlate with radiometrically warm regions. We examined scatterplots of the normalized radar cross-section sigma(0) versus brightness temperature, finding differing signatures that characterize various terrains and surface features. Implications for the physical and compositional properties of these features are discussed. The results indicate that volume scattering is important in many areas of Titan's surface, particularly Xanadu, while other areas exhibit complex brightness temperature variations consistent with variable slopes or surface material and compositional properties. (C) 2007 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Johns Hopkins Univ, Appl Phys Lab, Planetary Explorat Grp, Dept Space, Laurel, MD 20723 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. INAF, IFSI, I-00133 Rome, Italy. Proxemy Res, Bowie, MD 20715 USA. US Geol Survey, Flagstaff, AZ 86001 USA. RP Paganelli, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM flora.paganeili@jpl.nasa.gov 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 34 TC 27 Z9 27 U1 0 U2 1 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 NOV 1 PY 2007 VL 191 IS 1 BP 211 EP 222 DI 10.1016/j.icarus.2007.04.032 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400016 ER PT J AU de Kok, R Irwin, PGJ Teanby, NA Nixon, CA Jennings, DE Fletcher, L Howett, C Calcutt, SB Bowles, NE Flasar, FM Taylor, FW AF de Kok, R. Irwin, P. G. J. Teanby, N. A. Nixon, C. A. Jennings, D. E. Fletcher, L. Howett, C. Calcutt, S. B. Bowles, N. E. Flasar, F. M. Taylor, F. W. TI Characteristics of Titan's stratospheric aerosols and condensate clouds from Cassini CIRS far-infrared spectra SO ICARUS LA English DT Article DE titan; atmospheres; composition; infrared observations ID ROTOTRANSLATIONAL ABSORPTION-SPECTRA; VOYAGER-1 RADIO-OCCULTATION; NORTH POLAR STRATOSPHERE; SPECTROSCOPIC DATABASE; LATITUDINAL VARIATIONS; MIDLATITUDE CLOUDS; THERMAL EMISSION; SATURN SYSTEM; HUYGENS PROBE; ATMOSPHERE AB Four broad spectral features were identified in far-infrared limb spectra from the Cassini Composite Infrared Spectrometer (CIRS), two of which have not been identified before. The features are broader than the spectral resolution, which suggests that they are caused by particulates in Titan's stratosphere. We derive here the spectral properties and variations with altitude for these four features for six latitudes between 65 degrees S and 85 degrees N. Titan's main aerosol is called Haze 0 here. It is present at all wavenumbers in the far-infrared and is found to have a fractional scale height (i.e., the aerosol density scale height divided by the atmospheric density scale height) between 1.5 and 1.7 with a small increase in opacity in the north. A second feature around 140 cm(-1) (Haze A) has similar spatial properties to Haze 0, but has a smaller fractional scale height of 1.2-1.3. Both Haze 0 and Haze A show an increase in retrieved abundance below 100 km. Two other features (Haze B around 220 cm(-1) and Haze C around 190 cm(-1)) have a large maximum in their density profiles at 140 and 90 km, respectively. Haze B is much more abundant in the northern hemisphere compared to the southern hemisphere. Haze C also shows a large increase towards the north, but then disappears at 85 degrees N. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Oxford, Clarendon Lab, Dept Phys, Oxford OX1 3PU, England. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP de Kok, R (reprint author), Univ Oxford, Clarendon Lab, Dept Phys, Parks Rd, Oxford OX1 3PU, England. EM remco@atm.ox.ac.uk RI Fletcher, Leigh/D-6093-2011; Nixon, Conor/A-8531-2009; Flasar, F Michael/C-8509-2012; Jennings, Donald/D-7978-2012; OI Fletcher, Leigh/0000-0001-5834-9588; Nixon, Conor/0000-0001-9540-9121; Calcutt, Simon/0000-0002-0102-3170; Teanby, Nicholas/0000-0003-3108-5775; Irwin, Patrick/0000-0002-6772-384X NR 56 TC 56 Z9 57 U1 0 U2 4 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 NOV 1 PY 2007 VL 191 IS 1 BP 223 EP 235 DI 10.1016/j.icarus.2007.04.003 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400017 ER PT J AU Grav, T Bauer, J AF Grav, Tommy Bauer, James TI A deeper look at the colors of the saturnian irregular satellites SO ICARUS LA English DT Article DE irregular satellites; photometry; satellites, surfaces; Saturn, satellites ID TRANS-NEPTUNIAN OBJECTS; OUTER JOVIAN-SATELLITES; KUIPER-BELT OBJECT; SOLAR-SYSTEM; DARK SIDE; ASTEROID FAMILIES; PLANET FORMATION; MOON PHOEBE; GAS-DRAG; IAPETUS AB We have performed broadband color photometry of the twelve brightest irregular satellites of Saturn with the goal of understanding their surface composition, as well as their physical relationship. We find that the satellites have a wide variety of different surface colors, from the negative spectral slopes of the two retrograde satellites S IX Phoebe (S' = -2.5 +/- 0.4) and S XXV Mundilfari (S' = -5.0 +/- 1.9) to the fairly red slope of S XXII Ijiraq (S' = 19.5 +/- 0.9). We further find that there exist a correlation between dynamical families and spectral slope, with the prograde clusters, the Gallic and Inuit, showing tight clustering in colors among most of their members. The retrograde objects are dynamically and physically more dispersed, but some internal structure is apparent. (C) 2007 Elsevier Inc. All rights reserved. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Grav, T (reprint author), Harvard Smithsonian Ctr Astrophys, MS 51,60 Garden St, Cambridge, MA 02138 USA. EM tgrav@cfa.harvard.edu NR 72 TC 10 Z9 10 U1 1 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 NOV 1 PY 2007 VL 191 IS 1 BP 267 EP 285 DI 10.1016/j.icarus.2007.04.020 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400020 ER PT J AU Grundy, WM Stansberry, JA Noll, KS Stephens, DC Trilling, DE Kern, SD Spencer, JR Cruikshank, DP Levison, HF AF Grundy, W. M. Stansberry, J. A. Noll, K. S. Stephens, D. C. Trilling, D. E. Kern, S. D. Spencer, J. R. Cruikshank, D. P. Levison, H. F. TI The orbit, mass, size, albedo, and density of (65489) Ceto/Phorcys: A tidally-evolved binary Centaur SO ICARUS LA English DT Article DE Centaurs; Kuiper belt; trans-neptunian objects; satellites ID KUIPER-BELT OBJECTS; HUBBLE-SPACE-TELESCOPE; JUPITER-FAMILY COMETS; SOLAR-SYSTEM; TRANSNEPTUNIAN OBJECTS; ADVANCED CAMERA; LIGHT CURVES; SATELLITES; POPULATION; PHOTOMETRY AB Hubble Space Telescope observations of Uranus- and Neptune-crossing object (65489) Ceto/Phorcys (provisionally designated 2003 FX128) reveal it to be a close binary system. The mutual orbit has a period of 9.554 +/- 0.011 days and a semimajor axis of 1840 +/- 48 km. These values enable computation of a system mass of (5.41 +/- 0.42) x 10(18) kg. Spitzer Space Telescope observations of thermal emission at 24 and 70 Pin are combined with visible photometry to constrain the system's effective radius (109(-11)(+10) km) and geometric albedo (0.084(-0.014)(+0.021)) We estimate the average bulk density to be 1.37-(+0.66)(0.32) gcm(-3), consistent with ice plus rocky and/or carbonaceous materials. This density contrasts with lower densities recently measured with the same technique for three other comparably-sized outer Solar System binaries (617) Patroclus, (26308) 1998 SM165, and (47171) 1999 TC36, and is closer to the density of the saturnian irregular satellite Phoebe. The mutual orbit of Ceto and Phorcys is nearly circular. with an eccentricity <= 0.015. This observation is consistent with calculations suggesting that the system should tidally evolve on a timescale shorter than the age of the Solar System. (C) 2007 Elsevier Inc. All rights reserved. C1 Lowell Observ, Flagstaff, AZ 86001 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. SW Res Inst, Boulder, CO 80302 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Grundy, WM (reprint author), Lowell Observ, 1400 W Mars Hill Rd, Flagstaff, AZ 86001 USA. EM w.grundy@lowell.edu RI Noll, Keith/C-8447-2012; Levison, Harold/C-6061-2013 OI Levison, Harold/0000-0001-5847-8099 NR 73 TC 30 Z9 30 U1 1 U2 1 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 NOV 1 PY 2007 VL 191 IS 1 BP 286 EP 297 DI 10.1016/j.icarus.2007.04.004 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400021 ER PT J AU Brunetto, R Roush, TL Marra, AC Orofino, V AF Brunetto, Rosario Roush, Ted L. Marra, Anna Cinzia Orofino, Vincenzo TI Optical characterization of laser ablated silicates SO ICARUS LA English DT Article DE asteroids; surfaces; centaurs; Spectroscopy; experimental techniques ID BIDIRECTIONAL REFLECTANCE SPECTROSCOPY; ION IRRADIATION EXPERIMENTS; FROZEN METHANOL; AIRLESS BODIES; NEAR-EARTH; WATER ICE; MU-M; SPACE; SIMULATION; CONSTANTS AB We perform an optical characterization of UV laser ablated silicates (olivine, pyroxene), starting from their reflectance spectra in the 0.3-2.5 mu m spectral range. The goal is to provide useful tools to model space weathering effects on surfaces of asteroids and TNOs (trans-neptunian objects). We determine that the reddening and darkening spectral trend is compatible with the Hapke's space weathering model, using the optical constants of metallic iron in a silicate matrix. This result is supported by new magnetic susceptibility measurements on laser ablated orthopyroxene. We also investigate the potential contribution of formation of amorphous silicates in the process. Applying our results to silicate-rich surfaces in the Solar System, we investigate the possibility of a weathered olivine component on the surface of Centaur 5145 Pholus. Inclusion of this component slightly decreases the amount of complex organics and water ice from those previously estimated. Thus, the current Pholus spectrum is consistent with the presence of either unweathered or weathered olivine, or potentially both materials. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Lecce, Dipartimento Fis, I-73100 Lecce, Italy. INAF Osservatorio Astrofis Catania, I-95123 Catania, Italy. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Brunetto, R (reprint author), Univ Lecce, Dipartimento Fis, Via Arnesano, I-73100 Lecce, Italy. EM rosario.brunetto@le.infn.it NR 40 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 NOV 1 PY 2007 VL 191 IS 1 BP 381 EP 393 DI 10.1016/j.icarus.2007.04.023 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400029 ER PT J AU Bezard, B Nixon, CA Kleiner, I Jennings, DE AF Bezard, Bruno Nixon, Conor A. Kleiner, Isabelle Jennings, Donald E. TI Detection of (CH3D)-C-13 on Titan SO ICARUS LA English DT Article DE Titan; atmospheres; composition ID MU-M; MASS-SPECTROMETER; LINE-INTENSITIES; ATMOSPHERE; SPECTROSCOPY; ABUNDANCES; JUPITER; CH3D; PARAMETERS; SPECTRA AB We report the detection of (CH3D)-C-13 in Titan's stratosphere from Cassini/CIRS infrared spectra near 8.7 mu m. Fitting simultaneously the nu(6) bands of both (CH3D)-C-13 and (CH3D)-C-12 and the nu(4) band of CH4, we derive a D/H ratio equal to 1.32(-0).(+0.15)(11) x 10(-4) and a C-12/C-13 ratio in deuterated methane of 82(-18)(+27), consistent with that measured in normal methane. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Paris Diderot, UPMC, CNRS, Observ Paris,LESIA, F-92190 Meudon, France. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Univ Paris 07, Univ Paris 12, LISA, F-94100 Creteil, France. CNRS, F-94100 Creteil, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bezard, B (reprint author), Univ Paris Diderot, UPMC, CNRS, Observ Paris,LESIA, 5 Pl Jules Janssen, F-92190 Meudon, France. EM bruno.bezard@obspm.fr RI Nixon, Conor/A-8531-2009; Jennings, Donald/D-7978-2012 OI Nixon, Conor/0000-0001-9540-9121; NR 22 TC 54 Z9 54 U1 0 U2 5 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 NOV 1 PY 2007 VL 191 IS 1 BP 397 EP 400 DI 10.1016/j.icarus.2007.06.004 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 228XR UT WOS:000250766400031 ER PT J AU Rosen, PA Hensley, S Wheeler, K Sadowy, G Miller, T Shaffer, S Muellerschoen, R Jones, C Madsen, S Zebker, H AF Rosen, Paul A. Hensley, Scott Wheeler, Kevin Sadowy, Greg Miller, Tim Shaffer, Scott Muellerschoen, Ron Jones, Cathleen Madsen, Soren Zebker, Howard TI UAVSAR: New NASA airborne SAR system for research SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article ID RADAR INTERFEROMETRY AB NASA's Jet Propulsion Laboratory is currently building a reconfigurable, polarimetric L-band synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track SAR data for differential interferometric measurements. Differential interferometry can provide key deformation measurements, important for studies of earthquakes, volcanoes, and other dynamically changing phenomena. Using precision real-time GPS and a sensor controlled flight management system, the system will be able to fly pre-defined paths with great precision. The expected performance of the flight control system will constrain the flight path to be within a 10 m diameter tube about the desired flight track. The radar will be designed to be operable on a Unpiloted Arial Vehicle (UAV) but will initially be demonstrated on a NASA Gulfstream III. The radar will be fully polarimetric, with a range bandwidth of 80 MHz (2 m range resolution), and will support a 16 km range swath. The antenna will be electronically steered along track to assure that the antenna beam can be directed independently, regardless of the wind direction and speed. Other features supported by the antenna include elevation monopulse and pulse-to-pulse re-steering capabilities that will enable some novel modes of operation. The system will nominally operate at 45,000 feet (13,800 m). The program began as an Instrument Incubator Project (IIP) funded by NASA Earth Science and Technology Office (ESTO). C1 CALTECH, Jet Propuls Lab, Radar Sci & Engn Sect, Pasadena, CA 91125 USA. Stanford Univ, Stanford, CA 94305 USA. RP Rosen, PA (reprint author), CALTECH, Jet Propuls Lab, Radar Sci & Engn Sect, Pasadena, CA 91125 USA. NR 5 TC 7 Z9 8 U1 2 U2 17 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD NOV PY 2007 VL 22 IS 11 BP 21 EP 28 DI 10.1109/MAES.2007.4408523 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 234VG UT WOS:000251191600005 ER PT J AU Siegel, PH AF Siegel, Peter H. TI THz instruments for space SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE space instruments; submillimeter wave; terahertz (THz) ID MICROWAVE LIMB SOUNDER; SUBMILLIMETER ASTRONOMY; HETERODYNE INSTRUMENT; INFRARED ASTRONOMY; UPPER-ATMOSPHERE; CARBON-MONOXIDE; MISSION; MILLIMETER; SATELLITE; PERFORMANCE AB Terahertz technology has been driven largely by applications in astronomy and space science. For more than three decades cosmochemists, molecular spectroscopists, astrophysicists, and Earth and planetary scientists have used submillimeter-wave or terahertz sensors to identify, catalog and map lightweight gases, atoms and molecules in Earth and planetary atmospheres, in regions of interstellar dust and star formation, and in new and old galaxies, back to the earliest days of the universe, from both ground based and more recently, orbital platforms. The past ten years have witnessed the launch and successful deployment of three satellite instruments with spectral line heterodyne receivers above 300 GHz (SWAS, Odin, and MIRO) and a fourth platform, Aura MLS, that reaches to 2520 GHz, crossing the terahertz threshold from the microwave side for the first time. The former Soviet Union launched the first bolometric detectors for the submillimeter way back in 1974 and operated the first space based submillimeter wave telescope on the Salyut 6 station for four months in 1978. In addition, continuum, Fourier transform and spectrophotometer instruments on IRAS, ISO, COBE, the recent Spitzer Space Telescope and Japan's Akari satellite have all encroached into the submillimeter from the infrared using direct detection bolometers or photoconductors. At least two more major satellites carrying submillimeter wave instruments are nearing completion, Herschel and Planck, and many more are on the drawing boards in international and national space organizations such as NASA, ESA, DLR, CNES, and JAXA. This paper reviews some of the programs that have been proposed, completed and are still envisioned for space applications in the submillimeter and terahertz spectral range. C1 CALTECH, Div Biol, Beckman Inst, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Siegel, PH (reprint author), CALTECH, Div Biol, Beckman Inst, Pasadena, CA 91125 USA. EM phs@caltech.edu NR 71 TC 85 Z9 89 U1 1 U2 22 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 NOV PY 2007 VL 55 IS 11 BP 2957 EP 2965 DI 10.1109/TAP.2007.908557 PN 1 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 231EP UT WOS:000250929600003 ER PT J AU Hsu, SH Han, C Huang, J Chang, K AF Hsu, Shih-Hsun Han, Chuhnin Huang, John Chang, Kai TI An offset linear-array-fed Ku/Ka dual-band reflectarray for planet cloud/precipitation radar SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE antenna array feeds; beam steering; cylindrical reflector; reflectarray antenna ID CIRCULARLY-POLARIZED REFLECTARRAY; VARIABLE ROTATION ANGLES; MICROSTRIP RING ELEMENTS; WAVE-GUIDE APPROACH; HIGH-EFFICIENCY; THIN MEMBRANES; ANTENNA; PATCHES; DESIGN; SIZE AB A Ku/Ka band dual-frequency offset array-fed microstrip reflectarray antenna using thin membranes has been developed.-This antenna-is a demonstration model for the next generation Titan Cloud Precipitation Radar and Altimeter (TCPRA) and is intended to enhance the capability of the future cloud and precipitation remote sensing system for Earth and other planets. The reflectarray has a dimension of 0.5-m square and a flat aperture that emulates a cylindrical reflector antenna. Two sets of linear arrays with linearly polarized microstrip elements and having low cross polarization and low sidelobe levels (SLL) are placed along the focal line to illuminate the reflectarray. One set is for Ku-band, while the other is for Ka-band. Within each set, the wide-swath scanning capability of the antenna is provided by the two fixed-beam feed arrays with one for broadside beam and the other one for a 20 degrees tilted beam. The unique feature of this paper is that this is the first offset-fed reflectarray that has ever been practically developed to emulate a cylindrical/parabolic type of reflector antenna. In addition, new dual-concentric-ring elements and ring-patch elements are uniquely applied here to achieve the desirable wide phase variation characteristics. Tests of feed arrays and the reflectarray in the anechoic chamber of Texas A&M University result in good pattern performance and the successful demonstration of beam scanning at both frequency bands. C1 Texas A&M Univ, Dept Elect & Comp Engn, College Stn, TX 77843 USA. Ethertron Inc, San Diego, CA 92121 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. RP Hsu, SH (reprint author), Texas A&M Univ, Dept Elect & Comp Engn, College Stn, TX 77843 USA. EM shihhsun@ece.tamu.edu; chan@ethertronics.com; jhuang@pop.jpl.nasa.gov; chang@ece.tamu.edu NR 24 TC 22 Z9 22 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-926X EI 1558-2221 J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD NOV PY 2007 VL 55 IS 11 BP 3114 EP 3122 DI 10.1109/TAP.2007.908841 PN 2 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 231EQ UT WOS:000250929700001 ER PT J AU Refaat, TE Abedin, MN Sulima, OV Ismail, S Singh, UN AF Refaat, Tamer E. Abedin, M. Nurul Sulima, Oleg V. Ismail, Syed Singh, Upendra N. TI 2.4-mu m-cutoff AlGaAsSb/InGaAsSb phototransistors for shortwave-IR applications SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE characterization; heterojunction; infrared (IR); phototransistor ID MU-M; GASB; PHOTODETECTORS; RECOMBINATION; PERFORMANCE; GAINASSB; RANGE; BAND AB Shortwave-infrared (IR) detectors are critical for several applications, including remote sensing and optical communications. Several detectors are commercially available for this wavelength range, but they lack sufficient gain that limits their detectivity. The characterization results of AlGaAsSb/InGaAsSb phototransistors for shortwave-IR application are reported. The phototransistors are grown using molecular beam epitaxy technique. Spectral-response measurements showed a uniform responsivity between 1.2- and 2.4-mu m region with a mean value of 1000 A/W. A maximum detectivity of 3.4 x 10(11) cm - Hz(1/2)/W was obtained at 2 mu m at - 20 degrees C and 1.3 V. C1 Old Dominion Univ, Appl Res Ctr, Newport News, VA 23606 USA. NASA, Langley Res Ctr, Chem & Dynam Branch, Hampton, VA 23681 USA. Univ Delaware, Dept Elect & Comp Engn, Newark, DE 19716 USA. NASA, Langley Res Ctr, Syst Engn Directorate, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Remote Sensing Flight Syst Branch, Hampton, VA 23681 USA. RP Refaat, TE (reprint author), Old Dominion Univ, Appl Res Ctr, Newport News, VA 23606 USA. EM trefaat@jlab.org NR 26 TC 0 Z9 0 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD NOV PY 2007 VL 54 IS 11 BP 2837 EP 2842 DI 10.1109/TED.2007.907145 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 226LI UT WOS:000250590200004 ER PT J AU Margarit, G Mallorqui, JJ Fabregas, X AF Margarit, Gerard Mallorqui, Jordi J. Fabregas, Xavier TI Single-pass polarimetric SAR interferometry for vessel classification SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 6th European Conference on Synthetic Aperture Radar CY MAY 16-18, 2006 CL Dresden, GERMANY DE coherent target decomposition (CTD); polarimetric synthetic aperture radar interferometry (PolInSAR); vessel classification ID RADAR POLARIMETRY; IMAGES; SHIP; SCATTERING; TARGETS; SURFACE; TIME AB This paper presents a novel method for vessel classification based on single-pass polarimetric synthetic aperture radar (SAR) interferometry. It has been developed according to recent ship scattering studies that show that the polarimetric response of many types of vessels can be described by trihedral- and dihedral-like mechanisms. The adopted methodology is quite simple. The input interferometric data are decomposed in terms of the Pauli basis, and hence, one height image is derived for each simple mechanism. Then, the local maxima of these images are isolated, and a 3-D map of scatters is generated. The correlation of this map with the scattering distribution expected for a set of reference ships provides the final classification decision. The performance of the proposed method has been tested with the orbital SAR simulator developed at Universitat Politecnica de Catalunya. Different vessel models have been processed with a sensor configuration similar to the incoming TanDEM-X system. The analysis of diverse vessel bearings, vessel speeds, and sea states shows that the map of scatters matches reasonably the geometry of ships allowing a correct identification even for adverse environmental conditions. C1 Univ Politecn Cataluna, Remote Sensing Lab, Barcelona, Spain. Jet Propuls Lab, Pasadena, CA USA. German Aerosp Agcy, HR Inst, Oberpfaffenhofen, Germany. RP Margarit, G (reprint author), Univ Politecn Cataluna, Remote Sensing Lab, Barcelona, Spain. EM gerardm@tsc.upc.edu; mallorqui@tsc.upc.edu; fabregas@tsc.upc.edu RI Fabregas, Xavier/F-4852-2013; Mallorqui, Jordi/F-6594-2013 OI Fabregas, Xavier/0000-0002-7654-9695; Mallorqui, Jordi/0000-0002-9424-1889 NR 22 TC 31 Z9 36 U1 1 U2 14 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 NOV PY 2007 VL 45 IS 11 BP 3494 EP 3502 DI 10.1109/TGRS.2007.897437 PN 1 PG 9 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 229OA UT WOS:000250812600017 ER PT J AU Le Vine, DM Jackson, TJ Haken, M AF Le Vine, David M. Jackson, Thomas J. Haken, Michael TI Initial images of the synthetic aperture radiometer 2D-STAR SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE aperture synthesis; microwave radiometry; remote sensing; soil moisture ID MICROWAVE RADIOMETER; SOIL-MOISTURE; ESTAR AB Initial results are presented for the new synthetic aperture radiometer, 2D-STAR, which is a dual-polarized L-band radiometer that employs aperture synthesis in two dimensions. This airborne instrument is the natural evolution of the Electronically Scanned Thinned Array Radiometer, which employs aperture synthesis only in the across-track dimension, and represents a further step in the development of aperture synthesis for remote sensing applications. 2D-STAR was successfully tested in June 2003 and, then, participated in the SMEX03 and SMEX04 soil moisture experiments. A description of the instrument and initial results in the form of first images and a preliminary comparison with changes in soil moisture during SMEX03 are presented here. C1 NASA, Goddard Space Flight Ctr, Instrument Sci Branch, Greenbelt, MD 20771 USA. USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA. RS Informat Syst Inc, Goddard Space Flight Ctr, NASA, Greenbelt, MD 20771 USA. RP Le Vine, DM (reprint author), NASA, Goddard Space Flight Ctr, Instrument Sci Branch, Greenbelt, MD 20771 USA. EM david.m.levine@nasa.gov NR 19 TC 17 Z9 17 U1 2 U2 10 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 NOV PY 2007 VL 45 IS 11 BP 3623 EP 3632 DI 10.1109/FGRS.2007.903830 PN 2 PG 10 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 229OC UT WOS:000250812800003 ER PT J AU Atwood, DK Guritz, RM Muskett, RR Lingle, CS Sauber, JM Freymueller, JT AF Atwood, Donald K. Guritz, Richard M. Muskett, Reginald R. Lingle, Craig S. Sauber, Jeanne M. Freymueller, Jeffrey T. TI DEM control in arctic Alaska with ICESat laser altimetry SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE global positioning system; interferometry; terrain mapping; satellite applications; synthetic aperture (RADAR) ID INTERFEROMETRIC RADAR AB Use of Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry is demonstrated for control of a digital elevation model (DEM) that is synthesized from repeat-pass ERS-1 and 2 synthetic aperture radar (SAR) imagery using interferometric SAR (InSAR). Our study area is 15 650 kM2 of the Barrow, AK coastal plain adjacent to the Arctic Ocean; a vast expanse of tundra, lakes, and arctic wetlands of such low relief as to be nearly devoid of terrain features. The accuracy of the ICESat-derived elevation measurements is assessed by comparison with differential global positioning system (DGPS) data acquired along ICESat ground tracks. The ICESat-derived elevations have a mean accuracy, relative to the DGPS elevations, of -0.01 +/- 0.18 in. ICESat-derived elevations on the Arctic coastal plain provide an excellent source for DEM control. We employ, the ICESat-derived ground control points (GCPs) in two distinct InSAR processing steps: 1) selected points are used to perform baseline refinements, which improves the ERS-1 and 2 interferograms and 2) the ICESat-derived GCP position data (latitude, longitude, elevation) are then used as control in mosaicking multiple InSAR-derived DEMs. The resulting ICESat-controlled DEM has a mean accuracy of -1.11 +/- 6.3 in relative to an independent standard, which is a commercial airborne InSAR-derived DEM having 0.5 in rms accuracy. This easily meets DTED-2 standards and suggests that DEMs derived using only ICESat altimetry for ground control would meet similar standards in other regions of low relief. C1 Univ Alaska Fairbanks, Inst Geophys, Alaska Satellite Facil, Fairbanks, AK 99775 USA. Univ Alaska Fairbanks, Int Arctic Res Ctr, Fairbanks, AK 99775 USA. NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20902 USA. RP Atwood, DK (reprint author), Univ Alaska Fairbanks, Inst Geophys, Alaska Satellite Facil, Fairbanks, AK 99775 USA. EM datwood@asf.alaska.edu; rguritz@asf.alaska.edu; rmuskett@iarc.uaf.edu; clingle@gi.alaska.edu; Jeanne.M.Sauber-Rosenberg@nasa.gov; jfreymueller@gi.alaska.edu RI Sauber, Jeanne/D-7684-2012 NR 18 TC 13 Z9 13 U1 1 U2 6 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 NOV PY 2007 VL 45 IS 11 BP 3710 EP 3720 DI 10.1109/TGRS.2007.904335 PN 2 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 229OC UT WOS:000250812800011 ER PT J AU Radisic, V Sawdai, D Scott, D Deal, WR Dang, L Li, D Chen, J Fung, A Samoska, L Gaier, T Lai, R AF Radisic, Vesna Sawdai, Donald Scott, Dennis Deal, William R. Dang, Linh Li, Danny Chen, John Fung, Andy Samoska, Lorene Gaier, Todd Lai, Richard TI Demonstration of a 311-GHz fundamental oscillator using InPHBT technology SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE HBT; millimeter wave; monolithic microwave integrated circuit (MMIC); oscillator; sub-millimeter wave ID INJECTION LOCKING; BAND; GHZ AB In this paper, a sub-millimeter-wave HBT oscillator is reported. The oscillator uses a single-emitter 0.3 mu m x 15 mu m InP HBT device with maximum frequency of oscillation (f(max)) greater than 500 GHz. The passive components of the oscillator are realized in a two metal process with benzocyclobutene used as the primary transmission line dielectric. The oscillator is implemented in a common base topology due to its inherent instability. The design includes an on-chip resonator, output matching circuitry, and injection locking port. A free-running frequency of 311.6 GHz has been measured by down-converting the signal. Additionally, injection locking has been successfully demonstrated with up to 17.8 dB of injection-locking gain. This is the first fundamental HBT oscillator operating above 300 GHz. C1 Northrop Grumman Corp, Redondo Beach, CA 90278 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Radisic, V (reprint author), Northrop Grumman Corp, Redondo Beach, Redondo Beach, CA 90278 USA. EM vesna@ieee.org NR 14 TC 25 Z9 26 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD NOV PY 2007 VL 55 IS 11 BP 2329 EP 2335 DI 10.1109/TMTT.2007.907722 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA 230SY UT WOS:000250897400007 ER PT J AU Ngo, Q Yamada, T Suzuki, M Ominami, Y Cassell, AM Li, J Meyyappan, M Yang, CY AF Ngo, Quoc Yamada, Toshishige Suzuki, Makoto Ominami, Yusuke Cassell, Alan M. Li, Jun Meyyappan, M. Yang, Cary Y. TI Structural and electrical characterization of carbon nanofibers for interconnect via applications SO IEEE TRANSACTIONS ON NANOTECHNOLOGY LA English DT Article DE carbon nanofiber; interconnects; via ID CHEMICAL-VAPOR-DEPOSITION; FIELD-EFFECT TRANSISTORS; NANOTUBE INTERCONNECTS; DIMENSIONS; TRANSPORT AB We present temperature-dependent electrical characteristics of vertically aligned carbon nanofiber (CNF) arrays for on-chip interconnect applications. The study consists of three parts. First, the electron transport mechanisms in these structures are investigated using I-V measurements over a broad temperature range (similar to 4.4 K to 350 K). The measured resistivity in CNF arrays is modeled based on known graphite two-dimensional hopping electron conduction mechanism. The model is used because of the disordered graphite structure observed during high-resolution scanning transmission electron microscopy (STEM) of the CNF and CNF-metal interface. Second, electrical reliability measurements are performed at different temperatures to demonstrate the robust nature of CNFs for interconnect applications. Finally, some guidance in catalyst material selection is presented to improve the nanostructure of CNFs, making the morphology similar to multiwall nanotubes. C1 Santa Clara Univ, Ctr Nanostruct, Santa Clara, CA 95050 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 95050 USA. Kansas State Univ, Dept Chem, Manhattan, KS 66506 USA. RP Ngo, Q (reprint author), Santa Clara Univ, Ctr Nanostruct, Santa Clara, CA 95050 USA. EM junli@ksu.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 32 TC 39 Z9 39 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1536-125X J9 IEEE T NANOTECHNOL JI IEEE Trans. Nanotechnol. PD NOV PY 2007 VL 6 IS 6 BP 688 EP 695 DI 10.1109/TNANO.2007.907400 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Science & Technology - Other Topics; Materials Science; Physics GA 232PT UT WOS:000251032300014 ER PT J AU Zhang, H Mudawar, I Hasan, MM AF Zhang, Hui Mudawar, Issam Hasan, Mohammad M. TI Assessment of dimensionless CHF correlations for subcooled flow boiling in microgravity and earth gravity SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID CRITICAL HEAT-FLUX; WATER-FLOW; FORCED FLOW; BODY FORCE; ROUND TUBE; BURNOUT; CRISIS; COMPONENTS; LIQUID; MODEL AB A comprehensive review and analysis of prior subcooled flow boiling CHIF correlations was conducted to identify those correlations that provide the most accurate predictions for dielectric working fluids and small rectangular flow passages found in electronics cooling applications in both microgravity and Earth gravity. Since most prior correlations were derived from water databases, only those with dimensionless form were deemed potentially suitable for other working fluids. Only a small fraction of these dimensionless correlations were found to tackle other fluids and more complicated flow and heating configurations with acceptable accuracy. These correlations were ranked relative to mean error, mean absolute error, and root mean square error. Better predictions where achieved when correlations were based on the heated diameter rather than the hydraulic diameter because, of the ability of the former to better describe vapor development in subcooled flow. Two previous correlations by Hall and Mudawar provided the best overall CHIF predictions for both microgravity and Earth gravity. (c) 2007 Elsevier Ltd. All rights reserved. C1 Purdue Univ, Sch Mech Engn, Boiling & Two Phase Flow Lab, W Lafayette, IN 47907 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Mudawar, I (reprint author), Purdue Univ, Sch Mech Engn, Boiling & Two Phase Flow Lab, W Lafayette, IN 47907 USA. EM mudawar@ecn.purdue.edu NR 58 TC 17 Z9 17 U1 0 U2 15 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 NOV PY 2007 VL 50 IS 23-24 BP 4568 EP 4580 DI 10.1016/j.ijheatmasstransfer.2007.03.030 PG 13 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 229FW UT WOS:000250789600006 ER PT J AU Valota, L Kurwitz, C Shephard, A Best, F AF Valota, Luca Kurwitz, Cable Shephard, Adam Best, Frederick TI Microgravity flow regime data and analysis SO INTERNATIONAL JOURNAL OF MULTIPHASE FLOW LA English DT Article DE two-phase; microgravity; separator; void fraction; flow regime; multiphase flow AB To utilize the advantageous properties of two-phase flow in microgravity applications, the knowledge base of two-phase flow phenomena must be extended to include the effects of gravity. In the experiment described, data regarding the behavior of two-phase flow in a conduit under microgravity conditions (essentially zero gravity) are explored. Of particular interest, knowledge of the void fraction of the gas and liquid in a conduit is necessary to develop models for heat and mass transfer, pressure drop, and wall shear. An experiment was conducted under reduced gravity conditions to collect data by means of a capacitance void fraction sensor and high speed visual imagery. Independent parameters were varied to map the flow regime regions. These independent parameters include gas and liquid volumetric flow rates and saturation pressures. Void fraction measurements were taken at a rate of 100 Hz with six sensors at two locations along the conduit. Further, statistical parameters were developed from the void fraction measurements. Statistical parameters such as variance, signal-to-noise ratio, half height value, and linear area difference were calculated and found to have characteristics allowing flow regime identification. (c) 2007 Elsevier Ltd. All rights reserved. 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 Valota, L (reprint author), Texas A&M Univ, Dept Nucl Engn, College Stn, TX 77843 USA. EM l_valota@hotmail.com; kurwitz@tamu.edu; shephard@tamu.edu; fbest@tamu.edu NR 12 TC 6 Z9 9 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0301-9322 J9 INT J MULTIPHAS FLOW JI Int. J. Multiph. Flow PD NOV PY 2007 VL 33 IS 11 BP 1172 EP 1185 DI 10.1016/j.ijmultiphaseflow.2007.03.002 PG 14 WC Mechanics SC Mechanics GA 234VU UT WOS:000251193100003 ER PT J AU Liu, TS Montefort, J Liou, W Pantula, SR Shams, QA AF Liu, Tianshu Montefort, J. Liou, W. Pantula, S. R. Shams, Qamar A. TI Lift enhancement by static extended trailing edge SO JOURNAL OF AIRCRAFT LA English DT Article ID GURNEY FLAPS; ENHANCING TABS; FLOW-CONTROL; AIRFOIL AB A static extended trailing edge attached to a NACA0012 airfoil section is studied for achieving lift enhancement at a small drag penalty. It is indicated that the thin extended trailing edge can enhance the lift, whereas the zero-lift drag is not significantly increased. Experiments and calculations are conducted to compare the aerodynamic characteristics of the extended trailing edge with those of the Gurney flap and the conventional flap. The extended trailing edge, as a simple mechanical device added on a wing without altering the basic configuration, has a good potential to improve the cruise flight efficiency. C1 [Liu, Tianshu; Montefort, J.; Liou, W.; Pantula, S. R.] Western Michigan Univ, Dept Mech & Aeronaut Engn, Kalamazoo, MI 49008 USA. [Shams, Qamar A.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Liu, TS (reprint author), Western Michigan Univ, Dept Mech & Aeronaut Engn, Parkview Campus, Kalamazoo, MI 49008 USA. EM tianshu.liu@wmich.edu NR 23 TC 10 Z9 10 U1 2 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD NOV-DEC PY 2007 VL 44 IS 6 BP 1939 EP 1947 DI 10.2514/1.31995 PG 9 WC Engineering, Aerospace SC Engineering GA 242DE UT WOS:000251703900017 ER PT J AU Ulbrich, CW Atlas, D AF Ulbrich, Carlton W. Atlas, David TI Microphysics of raindrop size spectra: Tropical continental and maritime storms SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY LA English DT Article ID DROP SIZE; DISTRIBUTIONS; DISDROMETER; MODEL; SHAPE AB This work uses raindrop size spectra measured at the surface in tropical continental storms to determine the associated parameters of the best-fit gamma distributions. The physical processes responsible for those parameters and their relations to the measurable radar reflectivity Z and differential reflectivity ZDR are then explored. So too are their relations to quantitative measurements of rain. Comparison is then made with corresponding features previously reported in tropical maritime regimes. The storms observed in Brazil and Arecibo, Puerto Rico, have been divided into convective (C), transition (T), and stratiform (S) segments. The raindrop size distribution (DSD) parameters are clearly defined on a gamma parameter diagram (GPD) that shows 1) how median volume drop size D-0 increases from S to T to C segments of the rain while 2) the range of the spectrum breadth parameter mu increases, and the range of the slope parameter Lambda decreases in the same sequence of S to C. Drop growth occurs predominantly below the 0 degrees C level by collision, coalescence, and breakup in the C rains. The median volume diameter D-0 grows as more of the water is concentrated near that size and so the DSD narrows; that is, both mu and Lambda increase. In both maritime and continental storms the DSD in the convective portion of the storm approaches equilibrium. The coefficient A in the Z = AR(b) relation increases with D-0 while the exponent b approaches unity. The D-0 and A pair increase with, and appear to be determined largely by, the updraft strength, thus providing a possible means of determining the appropriate algorithms for rainfall measurement. Although the small drop number samples measured by the surface disdrometer relative to the large volumes sampled by a radar tend to truncate the DSD at both small and large drop sizes, narrow distributions with mu = 5 to 12 cannot be attributed to such an effect. Such narrow DSDs accord with common experience of monodispersed large drops at the beginning of a convective storm. There is also remarkable agreement of the surface-based observations of ZDR-Z-D-0 with the time-space variations from C to T to S rain types observed by radar in England and elsewhere. Because the C region of a storm often accounts for a major share of the rain accumulation despite its shorter duration, it is particularly important to measure that region more accurately. There are distinctive clusters of the generalized number parameter N-W versus D-0 between maritime and continental storms. Methods for remote sensing and parameterization must partition the rainstorms into convective, transition, and stratiform segments. C1 [Ulbrich, Carlton W.] Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. [Atlas, David] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Ulbrich, CW (reprint author), 106 Highland Dr, Clemson, SC 29631 USA. EM cwu@nctv.com NR 32 TC 47 Z9 50 U1 1 U2 9 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 NOV PY 2007 VL 46 IS 11 BP 1777 EP 1791 DI 10.1175/2007JAMC1649.1 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 240ZO UT WOS:000251626900006 ER PT J AU Marcus, S Kim, J Chin, T Danielson, D Laber, J AF Marcus, Steven Kim, Jinwon Chin, Toshio Danielson, David Laber, Jayme TI Influence of GPS precipitable water vapor retrievals on quantitative precipitation forecasting in Southern California SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY LA English DT Article ID GLOBAL POSITIONING SYSTEM; SOIL HYDROLOGY; MODEL; ASSIMILATION; IMPACT; PARAMETERIZATION; SIMULATION; RAINFALL; CLOUDS; SCHEME AB The effects of precipitable water vapor (PWV) retrievals from the Southern California Integrated GPS Network (SCIGN) on quantitative precipitation forecast (QPF) skill are examined over two flood-prone regions of Southern California: Santa Barbara (SB) and Ventura County (VC). Two sets of QPFs are made, one using the initial water vapor field from the NCEP 40-km Eta initial analysis, and another in which the initial Eta water vapor field is modified by incorporating the PWV data from the SCIGN receivers. Lateral boundary data for the QPFs, as well as the hydrostatic component of the GPS zenith delay data, are estimated from the Eta analysis. Case studies of a winter storm on 2 February during the 1997/98 El Nino, and storms leading up to the La Conchita, California, landslide on 10 January 2005, show notably improved QPFs for the first 3-6 h with the addition of GPS PWV data. For a total of 47 winter storm forecasts between February 1998 and January 2005 the average absolute QPF improvement is small; however, QPF improvements exceed 5 mm in several underpredicted rainfall events, with GPS data also improving most cases with overpredicted rainfall. The GPS improvements are most significant (above or near the 2 sigma level) when the low-level winds off the coast of Southern California are from the southern (SW to SE) quadrant. To extend the useful forecast skill enhancement beyond six hours, however, additional sources of water vapor data over broader areas of the adjacent Pacific Ocean are needed. C1 [Marcus, Steven; Chin, Toshio] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Kim, Jinwon] Univ Calif Los Angeles, Los Angeles, CA USA. [Danielson, David; Laber, Jayme] Natl Weather Serv, Forecast Off, Oxnard, CA USA. RP Marcus, S (reprint author), CALTECH, Jet Prop Lab, Mail Stop 238-600, Pasadena, CA 91109 USA. EM Steven.Marcus@jpl.nasa.gov OI Marcus, Steven/0000-0002-5763-6961 NR 28 TC 6 Z9 8 U1 0 U2 4 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 NOV PY 2007 VL 46 IS 11 BP 1828 EP 1839 DI 10.1175/2007JAMC1502.1 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 240ZO UT WOS:000251626900010 ER PT J AU Hong, G Yang, P Gao, BC Baum, BA Hu, YX King, MD Platnick, S AF Hong, Gang Yang, Ping Gao, Bo-Cai Baum, Bryan A. Hu, Yong X. King, Michael D. Platnick, Steven TI High cloud properties from three years of MODIS Terra and Aqua collection-4 data over the Tropics SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY LA English DT Article ID BULK SCATTERING PROPERTIES; GAS EXPERIMENT-II; RADIATIVE PROPERTIES; CIRRUS CLOUDS; ICE CRYSTALS; WATER-VAPOR; SATELLITE-OBSERVATIONS; STRATOSPHERIC AEROSOL; TEMPERATURE FEEDBACK; SPATIAL-RESOLUTION AB This study surveys the optical and microphysical properties of high (ice) clouds over the Tropics (30 degrees S 30 degrees N) over a 3-yr period from September 2002 through August 2005. The analyses are based on the gridded level-3 cloud products derived from the measurements acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard both the NASA Earth Observing System Terra and Aqua platforms. The present analysis is based on the MODIS collection-4 data products. The cloud products provide daily, weekly, and monthly mean cloud fraction, cloud optical thickness, cloud effective radius, cloud-top temperature, cloud-top pressure, and cloud effective emissivity, which is defined as the product of cloud emittance and cloud fraction. This study is focused on high-level ice clouds. The MODIS-derived high clouds are classified as cirriform and deep convective clouds using the International Satellite Cloud Climatology Project (ISCCP) classification scheme. Cirriform clouds make up more than 80% of the total high clouds, whereas deep convective clouds account for less than 20% of the total high clouds. High clouds are prevalent over the intertropical convergence zone (ITCZ), the South Pacific convergence zone (SPCZ), tropical Africa, the Indian Ocean, tropical America, and South America. Moreover, land-ocean, morning afternoon, and summer-winter variations of high cloud properties are also observed. C1 [Hong, Gang; Yang, Ping] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. [Gao, Bo-Cai] USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. [Baum, Bryan A.] Univ Wisconsin, Ctr Space Sci & Engn, Madison, WI 53706 USA. [Hu, Yong X.] NASA, Langley Res Ctr, Hampton, VA 23665 USA. [King, Michael D.; Platnick, Steven] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Yang, P (reprint author), Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. EM pyang@ariel.met.tamu.edu RI Yang, Ping/B-4590-2011; Baum, Bryan/B-7670-2011; King, Michael/C-7153-2011; Hong, Gang/A-2323-2012; Platnick, Steven/J-9982-2014; Hu, Yongxiang/K-4426-2012 OI Baum, Bryan/0000-0002-7193-2767; King, Michael/0000-0003-2645-7298; Platnick, Steven/0000-0003-3964-3567; NR 58 TC 36 Z9 38 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1558-8424 EI 1558-8432 J9 J APPL METEOROL CLIM JI J. Appl. Meteorol. Climatol. PD NOV PY 2007 VL 46 IS 11 BP 1840 EP 1856 DI 10.1175/2007JAMC1583.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 240ZO UT WOS:000251626900011 ER PT J AU Koshak, WJ Krider, EP Murray, N Boccippio, DJ AF Koshak, W. J. Krider, E. P. Murray, N. Boccippio, D. J. TI Lightning charge retrievals: Dimensional reduction, LDAR constraints, and a first comparison with LIS satellite data SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID FIELD CHANGES; DIAGNOSTIC-ANALYSIS; NETWORK; FLORIDA; THUNDERSTORMS; DISCHARGES AB A "dimensional reduction" ("DR") method is introduced for analyzing lightning field changes (Delta Es) whereby the number of unknowns in a discrete two-charge model is reduced from the standard eight (x, y, z, Q, x', y', z', Q') to just four (x, y, z, Q). The four unknowns (x, y, z, Q) are found by performing a numerical minimization of a chi-square function. At each step of the minimization, an overdetermined fixed matrix (OFM) method is used to immediately retrieve the best "residual source" (x', y', z', Q'), given the values of (x, y, z, Q). In this way, all eight parameters (x, y, z, Q, x', y', z', Q') are found, yet a numerical search of only four parameters (x, y, z, Q) is required. The DR method has been used to analyze lightning-caused Delta Es derived from multiple ground-based electric field measurements at the NASA Kennedy Space Center (KSC) and U.S. Air Force Eastern Range (ER). The accuracy of the DR method has been assessed by comparing retrievals with data provided by the lightning detection and ranging (LDAR) system at the KSC-ER, and from least squares error estimation theory, and the method is shown to be a useful "stand alone" charge retrieval tool. Since more than one charge distribution describes a finite set of Delta Es (i.e., solutions are nonunique), and since there can be appreciable differences in the physical characteristics of these solutions, not all DR solutions are physically acceptable. Hence, an alternative and more accurate method of analysis is introduced that uses LDAR data to constrain the geometry of the charge solutions, thereby removing physically unacceptable retrievals. The charge solutions derived from this method are shown to compare well with independent satellite- and ground-based observations of lightning in several Florida storms. C1 NASA, George C Marshall Space Flight Ctr, Earth Sci Off, Huntsville, AL 35805 USA. Univ Arizona, Tucson, AZ USA. RP Koshak, WJ (reprint author), NASA, George C Marshall Space Flight Ctr, Earth Sci Off, VP61,Robert Cramer Res Hall,320 Sparkman Dr, Huntsville, AL 35805 USA. EM william.koshak@nasa.gov NR 25 TC 5 Z9 6 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD NOV PY 2007 VL 24 IS 11 BP 1817 EP 1838 DI 10.1175/JTECH2089.1 PG 22 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 233WP UT WOS:000251121300001 ER PT J AU Pierrard, V Khazanov, GV Lemaire, JF AF Pierrard, V. Khazanov, G. V. Lemaire, J. F. TI Current-voltage relationship SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article DE current; electric field; ionosphere; magnetosphere; polar wind; kappa distribution ID PARALLEL ELECTRIC-FIELDS; POTENTIAL-ENERGY; MAGNETOSPHERIC PLASMA; CURRENT REGION; ION-EXOSPHERE; SOLAR-WIND; MODEL; DISTRIBUTIONS; ACCELERATION; FLUXES AB Potential drops accelerate ions and electrons along magnetic field lines and create currents flowing into and out of the ionosphere. Kinetic exospheric models similar to those developed for the polar wind have been used to determine the current density as a function of the electrostatic potential difference. In the upward current region of the auroral zone, the current-voltage relationship depends on the number density and temperature of the hot plasma of the plasmasheet and is quasi-linear for 100 V < V < 10 kV. This linear relationship cannot be extrapolated to return current regions, where the current is carried by the ionospheric electrons. FAST observations have shown significant potential drops in the return current regions, suggesting there a contribution of an anomalous resistance to the current-voltage relationship. The goal of the present paper is to describe and summarize the features of the field-aligned currents and of the various forms of current-voltage relationships in magnetospheric physics as well as the successive historical steps between their discovery and first formulation in 1973 and their most recent sophisticated ones. (C) 2007 Elsevier Ltd. All rights reserved. C1 Belgian Inst Space Aeronomy, B-1180 Brussels, Belgium. [Khazanov, G. V.] NASA, Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. [Lemaire, J. F.] Univ Catholique Louvain, Ctr Space Radiat, B-1348 Louvain, Belgium. RP Pierrard, V (reprint author), Belgian Inst Space Aeronomy, 3 Ave Circulaire, B-1180 Brussels, Belgium. EM viviane.pierrard@oma.be; George.Khazanov@nsste.nasa.gov; lemaire@astr.ucl.ae.be OI Pierrard, Viviane/0000-0001-5014-7682 NR 34 TC 8 Z9 8 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD NOV PY 2007 VL 69 IS 16 BP 2048 EP 2057 DI 10.1016/j.jastp.2007.08.005 PG 10 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 243MM UT WOS:000251801700007 ER PT J AU Iraci, LT Riffel, BG Robinson, CB Michelsen, RR Stephenson, RM AF Iraci, Laura T. Riffel, Brent G. Robinson, Carly B. Michelsen, Rebecca R. Stephenson, Rachel M. TI The acid catalyzed nitration of methanol: formation of methyl nitrate via aerosol chemistry SO JOURNAL OF ATMOSPHERIC CHEMISTRY LA English DT Article DE acid-catalyzed; aerosol chemistry; alcohol; nitration; sulfuric acid ID AQUEOUS SULFURIC-ACID; C-1-C-4 ALKYL NITRATES; MARINE SOURCE; NITRIC-ACID; SEASONAL-VARIATIONS; AROMATIC NITRATION; PACIFIC-OCEAN; SOLUBILITY; KINETICS; ACETALDEHYDE AB The aqueous phase acid-catalyzed reaction of methanol (CH3OH) with nitric acid (HNO3) to yield methyl nitrate (CH3ONO2) under atmospheric conditions has been investigated using gas-phase infrared spectroscopy. Reactions were conducted in aqueous sulfuric acid solutions (50.5-63.6 wt.%) with [CH3OH]= 0.00005-0.005 M and [HNO3]= 0.02-0.21 M, at 278.2-328.6 K. Methyl nitrate production rates increased linearly with CH3OH and HNO3 concentrations and exponentially with sulfuric acid weight percent within the regime studied. Rates increased linearly with nitronium ion (NO2+) concentration, indicating that the reaction involves NO2+ as the nitrating agent under these conditions. At 298 K, the rate of methyl nitrate production can be calculated from kappa(obs)[CH3OH] [HNO3], where kappa(obs)= 2.337 x 10(-13)(exp (0.3198* wt.% H2SO4)) when the solubility of CH3ONO2 in acidic solution is approximated by H* for pure water. The temperature dependence of the rate coefficient is related to solution composition, with activation energies of 59 and 49 kJ/mol at 51.1 and 63.6 wt.% H2SO4, respectively, when kappa is calculated from rate [NO2+](-1) [CH3OH](-1). The temperature dependence has also been parameterized for application to the atmosphere, but the small quantities of NO2+ present in aerosol particles will result in methyl nitrate production rates too small to be of significance under most atmospheric conditions. C1 [Iraci, Laura T.; Riffel, Brent G.; Robinson, Carly B.; Michelsen, Rebecca R.; Stephenson, Rachel M.] NASA, Ames Res Ctr, Atmospher Sci Branch, Moffett Field, CA 94035 USA. [Riffel, Brent G.] Univ Calif Davis, Inst Transportat Studies, Davis, CA 95616 USA. [Robinson, Carly B.] Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. [Michelsen, Rebecca R.] Randolph Macon Coll, Dept Chem, Ashland, VA 23005 USA. [Stephenson, Rachel M.] Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. RP Iraci, LT (reprint author), NASA, Ames Res Ctr, Atmospher Sci Branch, Mail Stop 245-5, Moffett Field, CA 94035 USA. EM Laura.T.Iraci@NASA.gov OI Robinson, Carly/0000-0002-8523-1478 NR 48 TC 5 Z9 5 U1 1 U2 20 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-7764 J9 J ATMOS CHEM JI J. Atmos. Chem. PD NOV PY 2007 VL 58 IS 3 BP 253 EP 266 DI 10.1007/s10874-007-9091-9 PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 244OI UT WOS:000251874800005 ER PT J AU Tamone, SL Taggart, SJ Andrews, AG Mondragon, J Nielsen, JK AF Tamone, Sherry L. Taggart, S. James Andrews, Alexander G. Mondragon, Jennifer Nielsen, Julie K. TI The relationship between circulating ecdysteroids and chela allometry in male tanner crabs: Evidence for a terminal molt in the genus Chionoecetes SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article ID MALE SNOW CRAB; BAIRDI RATHBUN DECAPODA; INHIBITING HORMONE MIH; AMINO-ACID-COMPOSITION; CALLINECTES-SAPIDUS; FUNCTIONAL MATURITY; CANCER-MAGISTER; SPIDER CRAB; OPILIO; CRUSTACEA AB Whether male Tanner crabs, Chionoecetes bairdi, undergo a terminal molt associated with a change in claw allometry has long been debated. We measured molting hormone levels in captured male C. bairdi to assess the potential for molting. We plotted a frequency histogram of chela height to carapace width ratios and found a bimodal distribution of crabs with a ratio of approximately 0.18 separating the two modes. Male crabs with a ratio less than 0.18 were classified as "small-clawed" (SC) while crabs with a ratio greater than 0.18 were classified as "large-clawed" (LC). Circulating molting hormones between SC and LC crabs were compared. Significantly lower ecdysteroid levels were found in LC crabs, indicating that this morphotype had negligible potential for molting. Circulating ecdysteroids were measured in SC males of different shell conditions (soft, new, old, and very old) and no significant differences were found. This research suggests that the molt to LC morphology is a terminal molt. The results front this study have important implications for fisheries management because sub-legal LC males will not recruit into the fishery and removal of larger males may have long term effects on population size structure. C1 Univ Alabama SE, Juneau, AK 99801 USA. US Geol Survey, Alaska Sci Ctr, Juneau, AK 99801 USA. Univ Alaska, Fairbanks Juneau Ctr, Sch Fisheries & Ocean Sci, Juneau, AK 99801 USA. Natl Marine Fisheries Serv, Juneau, AK 99801 USA. RP Tamone, SL (reprint author), Univ Alabama SE, 11120 Glacier Hwy, Juneau, AK 99801 USA. EM sherry.tamone@uas.alaska.edu; sjtaggart@usgs.gov; a.andrews@uaf.edu; Jennifer.Mondragon@noaa.gov; jk_nielsen@usgs.gov NR 53 TC 9 Z9 9 U1 0 U2 2 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 USA SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD NOV PY 2007 VL 27 IS 4 BP 635 EP 642 DI 10.1651/S-2802.1 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 226RR UT WOS:000250606700014 ER PT J AU Tragardh, E Schlegel, TT Carlsson, M Pettersson, J Nilsson, K Pahlm, O AF Tragardh, Elin Schlegel, Todd T. Carlsson, Marcus Pettersson, Jonas Nilsson, Klas Pahlm, Olle TI High-frequency electrocardiogram analysis in the ability to predict reversible perfusion defects during adenosine myocardial perfusion imaging SO JOURNAL OF ELECTROCARDIOLOGY LA English DT Article DE HF-QRS; MPI; adenosine; myocardial ischemia ID CORONARY-ARTERY-DISEASE; QRS POTENTIALS; EXERCISE; COMPONENTS; ISCHEMIA; INFARCTION; DEPRESSION; DIAGNOSIS; OCCLUSION; STANDARD AB Background: A previous study has shown that analysis of high-frequency QRS components (HF-QRS) is highly sensitive and reasonably specific for detecting reversible perfusion defects on adenosine myocardial perfusion imaging (MPI) scans. The purpose of the present study was to try to reproduce those findings. Methods: Twelve-lead high-resolution electrocardiogram recordings were obtained from 100 patients before (baseline) and during adenosine Tc-99m-tetrofosmin MPI tests. The HF-QRS were analyzed regarding morphology and changes in root mean square voltages from before the adenosine infusion to peak infusion. Results: The best area under the curve (AUC) was found in supine patients (AUC = 0.736) in a combination of morphology and root mean square changes. None of the measurements, however, were statistically better than tossing a coin (AUC = 0.5). Conclusion: Analysis of HF-QRS was not significantly better than tossing a coin for determining reversible perfusion defects on MPI scans. (C) 2007 Elsevier Inc. All rights reserved. C1 Lund Univ, Dept Clin Pathol, Lund, Sweden. NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. RP Tragardh, E (reprint author), Lund Univ, Dept Clin Pathol, Lund, Sweden. EM Elin.tragardh@med.lu.se RI Carlsson, Marcus/B-1905-2013 OI Carlsson, Marcus/0000-0002-9480-5250 NR 29 TC 3 Z9 3 U1 0 U2 0 PU CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS PI PHILADELPHIA PA CURTIS CENTER, INDEPENDENCE SQUARE WEST, PHILADELPHIA, PA 19106-3399 USA SN 0022-0736 J9 J ELECTROCARDIOL JI J. Electrocardiol. PD NOV-DEC PY 2007 VL 40 IS 6 BP 510 EP 514 DI 10.1016/j.jelectrocard.2007.03.242 PG 5 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA 235TZ UT WOS:000251258500013 PM 17531255 ER PT J AU Weaver, PM Nemeth, MP AF Weaver, Paul M. Nemeth, Michael P. TI Bounds on flexural properties and buckling response for symmetrically laminated composite plates SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID COMPRESSION; PARAMETERS; EQUATIONS; SHELLS; PANELS; LOADS AB Nondimensional parameters and equations governing the buckling behavior of rectangular symmetrically laminated plates are presented that can be used to represent the buckling resistance, for plates made of all known structural materials, in a very general, insightful, and encompassing manner. In addition, these parameters can be used to assess the degree of plate orthotropy, to assess the importance of anisotropy that couples bending and twisting deformations, and to characterize quasi-isotropic laminates quantitatively. Bounds for these nondimensional parameters are also presented that are based on thermodynamics and practical laminate construction considerations. These bounds provide insight into potential gains in buckling resistance through laminate tailoring and composite-material development. As an illustration of this point, upper bounds on the buckling resistance of long rectangular orthotropic plates with simply supported or clamped edges and subjected to uniform axial compression, uniform shear, or pure in-plane bending loads are presented. The results indicate that the maximum gain in buckling resistance for tailored orthotropic laminates, with respect to the corresponding isotropic plate, is in the range of 26-36% for plates with simply supported edges, irrespective of the loading conditions. For the plates with clamped edges, the corresponding gains in buckling resistance are in the range of 9-12% for plates subjected to compression or pure in-plane bending loads and potentially up to 30% for plates subjected to shear loads. C1 Univ Bristol, Dept Aerosp Engn, Bristol BS8 1TR, Avon, England. NASA, Langley Res Ctr, Struct Mech & Concepts Branch, Hampton, VA 23665 USA. RP Weaver, PM (reprint author), Univ Bristol, Dept Aerosp Engn, Queens Bldg, Bristol BS8 1TR, Avon, England. EM paul.weaver@bristol.ac.uk RI Weaver, Paul/D-5972-2011 OI Weaver, Paul/0000-0002-1905-4477 NR 31 TC 16 Z9 16 U1 1 U2 6 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD NOV PY 2007 VL 133 IS 11 BP 1178 EP 1191 DI 10.1061/(ASCE)0733-9399(2007)133:11(1178) PG 14 WC Engineering, Mechanical SC Engineering GA 222SS UT WOS:000250318100004 ER PT J AU Huntsberger, T Stroupe, A Aghazarian, H Garrett, M Younse, P Powell, M AF Huntsberger, Terry Stroupe, Ashley Aghazarian, Hrand Garrett, Mike Younse, Paulo Powell, Mark TI TRESSA: Teamed Robots for Exploration and Science on Steep Areas SO JOURNAL OF FIELD ROBOTICS LA English DT Article ID MULTIROBOT SYSTEMS AB Long-duration robotic missions on lunar and planetary surfaces (for example, the Mars Exploration Rovers have operated continuously on the Martian surface for close to 3 years) provide the opportunity to acquire scientifically interesting information from a diverse set of surface and subsurface sites and to explore multiple sites in greater detail. Exploring a wide range of terrain types, including plains, cliffs, sand dunes, and lava tubes, requires the development of robotic systems with mobility enhanced beyond that which is currently fielded. These systems include single as well as teams of robots. TRESSA (Teamed Robots for Exploration and Science on Steep Areas) is a closely coupled three-robot team developed at the Jet Propulsion Laboratory (JPL) that previously demonstrated the ability to drive on soil-covered slopes up to 70 deg. In this paper, we present results from field demonstrations of the TRESSA system in even more challenging terrain: rough rocky slopes of up to 85 deg. In addition, the integration of a robotic arm and instrument suite has allowed TRESSA to demonstrate semi-autonomous science investigation of the cliffs and science sample collection. TRESSA successfully traversed cliffs and collected samples at three Mars analog sites in Svalbard, Norway as part of a recent geological and astrobiological field investigation called AMASE: Arctic Mars Analog Svalbard Expedition under the NASA ASTEP (Astrobiology Science and Technology for Exploring Planets) program. (C) 2007 Wiley Periodicals, Inc. C1 CALTECH, Jet Prop Lab, Mobil & Robot Syst Sect, Pasadena, CA 91109 USA. RP Huntsberger, T (reprint author), CALTECH, Jet Prop Lab, Mobil & Robot Syst Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Terry.Huntsberger@jpl.nasa.gov; Ashley.Stroupe@jpl.nasa.gov; Hrand.Aghazarian@jpl.nasa.gov; Michael.Garrett@jpl.nasa.gov; Paulo.Younse@jpl.nasa.gov; Mark.Powell@jpl.nasa.gov NR 32 TC 11 Z9 11 U1 0 U2 4 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 1556-4959 J9 J FIELD ROBOT JI J. Field Robot. PD NOV-DEC PY 2007 VL 24 IS 11-12 BP 1015 EP 1031 DI 10.1002/rob.20219 PG 17 WC Robotics SC Robotics GA 234EB UT WOS:000251142400006 ER PT J AU Holdeman, JD Chang, CT AF Holdeman, James D. Chang, Clarence T. TI The effects of air preheat and number of orifices on flow and emissions in an RQL mixing section SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID REACTING CROSS-FLOW; CYLINDRICAL DUCT; MULTIPLE JETS; RICH; OPTIMIZATION; GEOMETRY AB This study was motivated by a goal to understand the mixing and emissions in the rich-burn/quick-mix/lean-burn combustor scheme that has been proposed to minimize the formation of oxides of nitrogen (NOx) in gas turbine combustors. The study reported in this paper was a reacting jet-in-crossflow experiment at atmospheric pressure in a cylindrical duct. The jets were injected from the perimeter of the duct through round-hole orifices into a fuel-rich mainstream flow. The number of orifices investigated in this study gave over to optimum to underpenetrating jets at a jet-to-mainstream momentum-flux ratio of 57. The size of individual orifices was decreased as their number increased to maintain a constant total area. The jet-to-mainstream mass-flow ratio was held constant at 2.5. The experiments focused on the effects of the number of orifices and inlet air preheat and were conducted in a facility that provided the capability, for independent variation of jet and main inlet air preheat temperature. The number of orifices was found to have a significant effect on mixing and the distributions of species, but very little effect on overall NOx emissions, suggesting that an aerodynamically optimum mixer may not minimize NOx emissions. Air preheat was found to have very little effect on mixing and the distributions of major species, but preheat did increase NOx emissions significantly. Although the air jets injected in the quick-mix section of a RQL combustor may comprise over 70% of the total air flow, the overall NOx emission levels were found to be more sensitive to mainstream air preheat than to jet stream air preheat. C1 [Holdeman, James D.; Chang, Clarence T.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Holdeman, JD (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM jjdholdeman@aol.com NR 20 TC 2 Z9 2 U1 2 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD NOV PY 2007 VL 129 IS 11 BP 1460 EP 1467 DI 10.1115/1.2786531 PG 8 WC Engineering, Mechanical SC Engineering GA 241KB UT WOS:000251654200011 ER PT J AU Chang, BJ Garcia, CP Johnson, DW Bents, DJ Scullin, VJ Jakupca, IJ AF Chang, Bei-jiann Garcia, Christopher P. Johnson, Donald W. Bents, David J. Scullin, Vincent J. Jakupca, Ian J. TI Continous operation of polymer electrolyte membrane regenerative fuel cell system for energy storage SO JOURNAL OF FUEL CELL SCIENCE AND TECHNOLOGY LA English DT Article AB NASA Glenn Research Center (GRC) has recently demonstrated a polymer electrolyte membrane (PEM) based regenerative fuel cell system (RFCS) that operated for five contiguous back-to-back 24 h charge/discharge cycles over a period of 120 h. The system operated continuously at full rated power with no significant reactant loss, breakdowns, or degradations from June 26 through July 1, 2005. It demonstrated a closed-loop solar energy storage system over repeated day/night cycles that absorbed solar electrical power profiles of 0-15 kWe and stored the energy as pressurized hydrogen and oxygen gas in charge mode, their delivered steady 4.5-5 kWe electrical power with product water during discharge mode. Fuel cell efficiency, electrolyzer efficiency, as well as system round-trip efficiency were determined. Individual cell performance and the spread of cell voltages within the electrochemical stacks were documented. The amount of waste heat dissipated from the RFCS was also reported. The RFCS demonstrated fully closed-cycle operation without venting or purging, thereby conserving reactant masses involved in the electrochemical processes. Smooth transitions between the fuel cell mode and electrolyzer mode were repeatedly accomplished. The RFCS is applicable to NASA's lunar and planetary surface solar power needs, providing lightweight energy storage for any multikilowatt-electrical application, where an environmentally sealed system is required. C1 [Chang, Bei-jiann; Garcia, Christopher P.; Johnson, Donald W.; Bents, David J.; Scullin, Vincent J.; Jakupca, Ian J.] NASA, QSS Grp Inc, Cleveland, OH 44135 USA. RP Chang, BJ (reprint author), NASA, QSS Grp Inc, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 4 TC 2 Z9 2 U1 1 U2 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 1550-624X J9 J FUEL CELL SCI TECH JI J. Fuel Cell Sci. Technol. PD NOV PY 2007 VL 4 IS 4 BP 497 EP 500 DI 10.1115/1.2756848 PG 4 GA 241JZ UT WOS:000251654000016 ER PT J AU Mortari, D Markley, FL Singla, P AF Mortari, Daniele Markley, F. Landis Singla, Puneet TI Optimal linear attitude estimator SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID VECTOR OBSERVATIONS; QUATERNION AB An optimal linear attitude estimator is presented for the case of a single-point real-time estimation of spacecraft attitude using the minimum-element attitude parameterization: Rodrigues (or Gibbs) vector g. The optimality criterion, which does not coincide with Wahba's constrained criterion, is rigorously quadratic and unconstrained. The singularity, which occurs when the principal angle is ir, can easily be avoided by one rotation. The attitude accuracy tests show that the proposed method provides a precision comparable with those fully complying with the Wahba optimality definition. Finally, computational speed tests demonstrate that the proposed method belongs to the class of the fastest optimal attitude estimation algorithms. C1 Texas A&M Univ, College Stn, TX 77843 USA. NASA, Goddard Space Flight Ctr, Control Syst Engn Branch, Greenbelt, MD 20771 USA. SUNY Buffalo, Buffalo, NY 14260 USA. RP Mortari, D (reprint author), Texas A&M Univ, 611C Bright Bldg, College Stn, TX 77843 USA. RI Singla, Puneet/D-3642-2012 OI Singla, Puneet/0000-0002-2441-2531 NR 15 TC 20 Z9 24 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD NOV-DEC PY 2007 VL 30 IS 6 BP 1619 EP 1627 DI 10.2514/1.29568 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 230OJ UT WOS:000250885500006 ER PT J AU Park, RS Scheeres, DJ AF Park, Ryan S. Scheeres, Daniel J. TI Nonlinear semi-analytic methods for trajectory estimation SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 21-24, 2006 CL Keystone, CO SP AIAA, AAS AB Nonlinear semi-analytic filtering methods to sequentially estimate spacecraft states and their associated uncertainties are presented. We first discuss the state transition tensors that characterize the localized nonlinear behavior of the trajectory statistics and illustrate the importance of higher-order effects on orbit uncertainty propagation. We then present a semi-analytic filtering method by implementing the state transition tensors to sequentially update the filter information with contributions from each measurement, which requires no integration once the tensors are computed. A sun-Earth halo orbit about the L, point is considered as an example with realistic orbit uncertainties, and the results are compared with the extended Kalman filter and unscented Kalman filter. C1 Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. RP Park, RS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Ryan.S.Park@jpl.nasa.gov; scheeres@umich.edu NR 15 TC 30 Z9 30 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD NOV-DEC PY 2007 VL 30 IS 6 BP 1668 EP 1676 DI 10.2514/1.29106 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 230OJ UT WOS:000250885500011 ER PT J AU Jeong, SI Didion, J AF Jeong, Seong-Il Didion, Jeffrey TI Thermal control utilizing an electrohydrodynamic conduction pump in a two-phase loop with high heat flux source SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE electrohydrodynamic; conduction pump; thermal control; high heat flux; two-phase ID PIPE AB The electric field applied in dielectric fluids causes an imbalance in the dissociation-recombination reaction generating free space charges. The generated charges are redistributed by the applied electric field, resulting in the heterocharge layers in the vicinity of the electrodes. Proper design of the electrodes generates net axial flow motion pumping the fluid. The electrohydrodynamic (EHD) conduction pump is a new device that pumps dielectric fluids utilizing heterocharge layers formed by imposition of electrostatic fields. This paper experimentally evaluates the performance of a two-phase (liquid-vapor) breadboard thermal control loop consisting of an EHD conduction pump, condenser, preheater evaporator transport lines, and reservoir (accumulator). This study is performed to address the feasibility of the EHD two-phase loop for thermal control of a laser equipment with high heat flux source. The generated pressure head and the maximum applicable heat flux are experimentally determined at various applied voltages and sink temperatures. Recovery from the evaporator dryout condition by increasing the applied voltage to the pump is also demonstrated. The performance of the EHD conduction pump in this study confirms that the EHD conduction pump can be used as a stand-alone system for high heat flux thermal control. C1 [Jeong, Seong-Il] Korea Adv Inst Sci & Technol, Satellite Technol Res Ctr, Taejon 305701, South Korea. [Didion, Jeffrey] NASA, Goddard Space Flight Ctr, Thermal Technol Dept, Greenbelt, MD 20771 USA. RP Jeong, SI (reprint author), Korea Adv Inst Sci & Technol, Satellite Technol Res Ctr, 373-1 Guseong Dong, Taejon 305701, South Korea. EM jeong05@gmail.com; Jeffrey.R.Didion@nasa.gov NR 18 TC 8 Z9 8 U1 1 U2 13 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD NOV PY 2007 VL 129 IS 11 BP 1576 EP 1583 DI 10.1115/1.2759971 PG 8 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 242LD UT WOS:000251725700012 ER PT J AU Smith, SJ AF Smith, S. J. TI Theoretical noise analysis on a position-sensitive Metallic Magnetic Calorimeter SO JOURNAL OF INSTRUMENTATION LA English DT Article DE cryogenic detectors; X-ray detectors; X-ray detectors and telescopes; data processing methods ID X-RAY SPECTROSCOPY; DETECTORS; MICROCALORIMETERS; RESOLUTION AB We report on the theoretical noise analysis for a position- sensitive Metallic Magnetic Calorimter (MMC), consisting of MMC read-out at both ends of a large X-ray absorber. Such devices are under consideration as alternatives to other cryogenic technologies for future X-ray astronomy missions. We use a finite-element model (FEM) to numerically calculate the signal and noise response at the detector outputs and investigate the correlations between the noise measured at each MMC coupled by the absorber. We then calculate, using the optimal filter concept, the theoretical energy and position resolution across the detector and discuss the trade-offs involved in optimising the detector design for energy resolution, position resolution and count rate. The results show, theoretically, the position-sensitive MMC concept offers impressive spectral and spatial resolving capabilities compared to pixel arrays and similar position-sensitive cryogenic technologies using Transition Edge Sensor (TES) read-out. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Smith, SJ (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. EM sjs@milkyway.gsfc.nasa.gov RI Smith, Stephen/B-1256-2008 OI Smith, Stephen/0000-0003-4096-4675 NR 20 TC 2 Z9 2 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1748-0221 J9 J INSTRUM JI J. Instrum. PD NOV PY 2007 VL 2 AR P11005 DI 10.1088/1748-0221/2/11/P11005 PG 12 WC Instruments & Instrumentation SC Instruments & Instrumentation GA 269MD UT WOS:000253652200004 ER PT J AU Mane, P Mossi, K Rostami, A Bryant, R Castro, N AF Mane, Poorna Mossi, Karla Rostami, Ali Bryant, Robert Castro, Nicolas TI Piezoelectric actuators as synthetic jets: Cavity dimension effects SO JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES LA English DT Article DE pre-stressed piezoelectric actuators; synthetic jet; Thunder((R)); Bimorph ID BOUNDARY-LAYER; ELEMENT; MODEL; DESIGN; DELAY AB Effects of dimensional cavity parameters, height, and orifice diameter, on synthetic jet peak velocities are investigated numerically and experimentally, utilizing two piezoelectric composite diaphragms, Bimorph and Thunder(R). The system is modeled using a RNG k-epsilon model with a mesh generated using a tri-pave unstructured scheme and the diaphragms are modeled as moving boundaries. The model compares within 15% for a Bimorph but underpredicts the results for Thunder(R) by more than 30%. For a Bimorph, both cavity parameters are relevant with the orifice diameter having a higher effect. For Thunder(R) however, only orifice diameter is found to be statistically significant. 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,PO Box 843015, Richmond, VA 23284 USA. EM kmmossi@vcu.edu NR 45 TC 12 Z9 12 U1 1 U2 4 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1045-389X J9 J INTEL MAT SYST STR JI J. Intell. Mater. Syst. Struct. PD NOV PY 2007 VL 18 IS 11 BP 1175 EP 1190 DI 10.1177/1045389X06075658 PG 16 WC Materials Science, Multidisciplinary SC Materials Science GA 233IR UT WOS:000251085100006 ER PT J AU Varaljay-Spence, VA Scardelletti, MC AF Varaljay-Spence, Vanessa A. Scardelletti, Maximilian C. TI Bench-top antigen detection technique that utilizes nanofiltration and fluorescent dyes which emit and absorb light in the near infrared SO JOURNAL OF LASER APPLICATIONS LA English DT Article DE near infrared fluorescent dye; microbe; antibody; antigen; nanofiltration; spectrometry AB This article discusses the development of a bench-top technique to detect antigens in fluids. The technique involves the use of near infrared (NIR) fluorescent dyes conjugated to antibodies, centrifugation, nanofilters, and spectrometry. The system used to detect the antigens utilizes a spectrometer, fiber optic cables, NIR laser, and laptop computer thus making it portable and ideally suited for desk top analysis. Using IgM as an antigen and the secondary antibody, anti-IgM conjugated to the near infrared dye, IRDye (TM) 800, for detection, we show that nanofiltration can efficiently and specifically separate antibody-antigen complexes in solution and that the complexes can be detected by a spectrometer and software using NIR laser excitation at 778 nm and NIR dye offset emission at 804 run. The peak power detected at 778 nm for the excitation emission and at 804 urn for the offset emission is 879 pW (-60.06 dBm) and 35.7 pW (-74.5 dBm), respectively. (c) 2007 Laser Institute of America. C1 [Varaljay-Spence, Vanessa A.; Scardelletti, Maximilian C.] NASA, Glenn Res Ctr, Brookpark, OH 44135 USA. [Varaljay-Spence, Vanessa A.] Cleveland State Univ, Dept Biol Geol & Environm Sci, Cleveland, OH 44115 USA. [Varaljay-Spence, Vanessa A.] Univ Georgia, Dept Microbiol, Athens, GA 30602 USA. RP Scardelletti, MC (reprint author), NASA, Glenn Res Ctr, Brookpark, OH 44135 USA. EM maximilian.c.scardelletti@nasa.gov NR 22 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1042-346X EI 1938-1387 J9 J LASER APPL JI J. Laser Appl. PD NOV PY 2007 VL 19 IS 4 BP 207 EP 213 DI 10.2351/1.2756856 PG 7 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA 247FN UT WOS:000252063200002 ER PT J AU Martin, S Drucker, RS Kwok, R AF Martin, Seelye Drucker, Robert S. Kwok, Ronald TI The areas and ice production of the western and central Ross Sea polynyas, 1992-2002, and their relation to the B-15 and C-19 iceberg events of 2000 and 2002 SO JOURNAL OF MARINE SYSTEMS LA English DT Article DE Antarctic zone; Ross Sea; sea ice; polynyas; icebergs ID NOVA BAY POLYNYA; SHELF; ANTARCTICA; VARIABILITY; DRIFT AB For 1992-2002, the paper investigates the heat loss and area of three polynyas in the western and central Ross Sea. These are the Ross Sea Polynya (RSP) and the much smaller Terra Nova Bay and McMurdo Sound polynyas. The importance of these polynyas is that their associated salt rejection contributes to the formation of the High Salinity Shelf Water (HSSW) that is crucial to the Antarctic Bottom Water formation. The study divides into two parts, 1992-1999, when there was negligible iceberg activity, and 2000-2002, when major icebergs calved and interacted with the polynyas. To retrieve the ice thicknesses and heat fluxes within the polynyas, the paper uses an algorithm based on the ratio of the vertically and horizontally polarized Special Sensor Microwave/Imager (SSM/I) 25-km resolution 37-GHz channels, combined with meteorological data. Because of sidelobe contamination, the ice shelf and icebergs are masked. Our results show that for the polynyas, and consistent with other observations, their mean winter area is about 30,000 km(2) and their combined ice production is about 500 km(3) y(-1). We also find that the polynya ice production approximately equals the ice export. This is in contrast to the Weddell Sea, where the polynya ice production equals about 6% of the ice export. For the years 2000 and 2002, the calving of large icebergs directly affect the ice production by inhibiting the ice production off the shelf due to piling up of first year ice upwind of the bergs and by generating new polynyas downwind of the bergs. The period 1992-2001 exhibits an upward trend in polynya productivity. The decadal increase in the ice production suggests that the observed HSSW salinity decrease in the western Ross Sea is not due to the polynyas, but is rather due to a change in the properties of the water flowing into the Ross. (c) 2007 Published by Elsevier B.V. C1 Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Martin, S (reprint author), Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98195 USA. EM seelye@ocean.washington.edu RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 30 TC 47 Z9 47 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-7963 J9 J MARINE SYST JI J. Mar. Syst. PD NOV PY 2007 VL 68 IS 1-2 BP 201 EP 214 DI 10.1016/j.jmarsys.2006.11.008 PG 14 WC Geosciences, Multidisciplinary; Marine & Freshwater Biology; Oceanography SC Geology; Marine & Freshwater Biology; Oceanography GA 232FJ UT WOS:000251003400011 ER PT J AU Nerger, L Gregg, WW AF Nerger, Lars Gregg, Watson W. TI Assimilation of SeaWiFS data into a global ocean-biogeochemical model using a local SEIK filter SO JOURNAL OF MARINE SYSTEMS LA English DT Article DE data assimilation; ecosystem modeling; Kalman filter; SEIK; ocean color; ocean chlorophyll ID ENSEMBLE KALMAN FILTER; CONSTRAINT PARAMETER-ESTIMATION; PHYSICAL-BIOLOGICAL MODEL; MARINE ECOSYSTEM MODEL; NORTH-ATLANTIC; COLOR DATA; SEA; OCEANOGRAPHY; OPTIMIZATION; FLUXES AB Chlorophyll data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) is assimilated into the three-dimensional global NASA Ocean Biogeochemical Model (NOBM) for the period 1998-2004 in order to obtain an improved representation of chlorophyll in the model. The assimilation is performed by the SEIK filter, which is based on the Kalman filter algorithm. The filter is implemented to univariately correct the concentration of surface total chlorophyll. A localized filter analysis is used and the filter is simplified by using a static state error covariance matrix. The assimilation provides daily global surface chlorophyll fields and improves the chlorophyll estimates relative to a model simulation without assimilation. The comparison with independent in situ data over the seven years also shows a significant improvement of the chlorophyll estimate. The assimilation reduces the RMS log error of total chlorophyll from 0.43 to 0.32, while the RMS log error is 0.28 for the in situ data considered. That is, the global RMS log error of chlorophyll estimated by the model is reduced by the assimilation from 53% to 13% above the error of SeaWiFS. Regionally, the assimilation estimate exhibits smaller errors than SeaWiFS data in several oceanic basins. (c) 2006 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Nerger, L (reprint author), NASA, Goddard Space Flight Ctr, Code 610-1, Greenbelt, MD 20771 USA. EM lnerger@gmao.gsfc.nasa.gov RI Nerger, Lars/G-4845-2013 OI Nerger, Lars/0000-0002-1908-1010 NR 44 TC 35 Z9 38 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-7963 J9 J MARINE SYST JI J. Mar. Syst. PD NOV PY 2007 VL 68 IS 1-2 BP 237 EP 254 DI 10.1016/j.jmarsys.2006.11.009 PG 18 WC Geosciences, Multidisciplinary; Marine & Freshwater Biology; Oceanography SC Geology; Marine & Freshwater Biology; Oceanography GA 232FJ UT WOS:000251003400013 ER PT J AU Brown, LR Humphrey, CM Gamache, RR AF Brown, L. R. Humphrey, C. M. Gamache, R. R. TI CO(2)-broadened water in the pure rotation and nu(2) fundamental regions SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE carbon dioxide broadened water; theoretical calculations; measurements; half-widths; pressure shifts; vibrational dependence; temperature dependence ID ASYMMETRIC-TOP MOLECULES; INTERMOLECULAR POTENTIAL PARAMETERS; DIODE-LASER MEASUREMENTS; RANGE DISPERSION ENERGY; ROBERT-BONAMY FORMALISM; VAPOR LINE PARAMETERS; MU-M REGION; HALF-WIDTHS; H2O-CO2 MIXTURES; H2O LINES AB The CO(2)-broadened water coefficients (half-widths, line shifts, and temperature dependence of the widths) are predicted using a fully complex Robert-Bonamy formulation for the 937 allowed and forbidden perpendicular type transitions of (000)-(000) between 200 and 900 cm(-1) in order to facilitate atmospheric remote sensing of Mars and Venus. In addition, empirical Lorentz line widths and pressure-induced frequency-shifts Of CO(2)-broadened H(2)(16)O are obtained at room temperature for 257 perpendicular transitions of the (0 10)-(000) fundamental. For this, calibrated spectra recorded at 0.0054 cm(-1) resolution are measured assuming Voigt line shapes. For transitions between 1287 and 1988 cm(-1) with rotational quanta up to J = 13 and K(a) = 6, the widths vary from 0.045 to 0.212 cm(-1) atm(-1) at 300 K; the pressure-shifts are quite large and range from -0.0386 to +0.0436 cm(-1) atm-1. For the (010)-(000) band, the RMS and mean observed and calculated differences for CO(2)-broadened H(2)O half-widths are 12% and -1.9%, respectively, while the RMS and mean ratios of the observed and calculated pressure-induced shift coefficients are 1.6 and 0.79, respectively. For pairs of transitions involving K(a) = 0 and 1, such as 2(02) <- 3(13) and 3(13) <- 2(02), both the calculated and observed pressure induced shifts in positions are opposite in sign and often similar in magnitude. The data are too limited to characterize vibrational dependencies of the widths, however. (C) 2007 Published by Elsevier Inc. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Massachusetts Lowell, Dept Environm Earth & Atmospher Sci, Lowell, MA 01854 USA. Univ Massachusetts, Sch Marine Sci, Lowell, MA 01854 USA. RP Brown, LR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Linda.R.Brown@jpl.nasa.gov NR 79 TC 30 Z9 32 U1 2 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 NOV PY 2007 VL 246 IS 1 BP 1 EP 21 DI 10.1016/j.jms.2007.07.010 PG 21 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 228WZ UT WOS:000250764600001 ER PT J AU Predoi-Cross, A Unni, AV Heung, H Devi, VM Benner, DC Brown, LR AF Predoi-Cross, Adriana Unni, Anildev V. Heung, Henry Devi, V. Malathy Benner, D. Chris Brown, Linda R. TI Line mixing effects in the nu(2) + nu(3) band of methane SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE methane; line mixing; off-diagonal relaxation matrix element; widths; pressure shifts; speed-dependent Voigt; multispectrum retrievals ID MOLECULAR SPECTROSCOPIC DATABASE; DIODE-LASER SPECTROSCOPY; NU(3) BAND; PLANETARY MEASUREMENTS; MULTISPECTRUM FITS; METHANE SPECTRA; V(3) BAND; R-BRANCH; MU-M; CH4 AB This study provides the first direct experimental measurements of the off-diagonal relaxation matrix element coefficients for line mixing in air-broadened methane spectra for any vibrational band and the first off diagonal relaxation matrix elements associated with line mixing for pure methane in the nu(2)+nu(3) band of (CH4)-C-12. The speed-dependent Voigt profile with line mixing is used with a multispectrum nonlinear least squares curve fitting technique to retrieve the various line parameters from 11 self-broadened and 10 air-broadened spectra simultaneously. The room temperature spectra analyzed in this work are recorded at 0.011 cm(-1) resolution with the McMath-Pierce Fourier transform spectrometer located at the National Solar Observatory, Kitt Peak, Arizona. The off-diagonal relaxation matrix element coefficients Of nu(2)+nu(3) transitions between 4410 and 4629 cm(-1) are reported for eighteen pairs with upper state J values between 2 and 11. The observed line mixing coefficients for self broadening vary from 0.0019 to 0.0390 cm(-1) atm(-1) at 296 K. The measured line mixing coefficients for air broadening vary from 0.0005 to 0.0205 cm(-1) atm(-1) at 296 K. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Lethbridge, Dept Phys, Lethbridge, AB T1K 3M4, Canada. Coll William & Mary, Dept Phys, Williamsburg, VA 23185 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Predoi-Cross, A (reprint author), Univ Lethbridge, Dept Phys, 4401 Univ Dr, Lethbridge, AB T1K 3M4, Canada. EM adriana.predoicross@uleth.ca NR 42 TC 17 Z9 17 U1 0 U2 4 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 NOV PY 2007 VL 246 IS 1 BP 65 EP 76 DI 10.1016/j.jms.2007.08.005 PG 12 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 228WZ UT WOS:000250764600005 ER PT J AU Adam, M Venable, D Connell, R Joseph, E Whiteman, DN Demoz, BB AF Adam, M. Venable, D. Connell, R. Joseph, E. Whiteman, D. N. Demoz, B. B. TI Performance of the Howard University Raman Lidar during 2006 WAVES campaign SO JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS LA English DT Article; Proceedings Paper CT 1st International Workshop on Optoelectronic Techniques for Environmental Monitoring and Risk Assessment CY MAY 21-24, 2007 CL Bucharest, ROMANIA DE Raman Lidar; WAVES; Howard University ID WATER-VAPOR; RATIOS AB The WAVES 2006 field campaign took place at the Howard University Research Campus in Beltsville, MD, USA during July and August. The field campaign was mainly intended to provide quality measurements of water vapor and ozone for comparison with AURA satellite retrievals. The operations include intensive observations by multiple radiosondes sensors and several lidar systems during overpasses of the AURA satellite. The Howard University Raman Lidar system operates at the third harmonic of a Nd:YAG laser and acquires data at 354.7 nm, 386.7 nm and 407.5 nm. The present study shows the temporal and spatial retrievals of the water vapor mixing ratio as well as comparisons of individual profiles with radiosondes and NASA/GSFC Scanning Raman Lidar system. C1 Howard Univ, Washington, DC 20059 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Adam, M (reprint author), Howard Univ, Washington, DC 20059 USA. EM madam@howard.edu RI Adam, Mariana/C-5661-2013; Demoz, Belay/N-4130-2014 NR 10 TC 4 Z9 4 U1 1 U2 2 PU NATL INST OPTOELECTRONICS PI BUCHAREST-MAGURELE PA 1 ATOMISTILOR ST, PO BOX MG-5, BUCHAREST-MAGURELE 76900, ROMANIA SN 1454-4164 J9 J OPTOELECTRON ADV M JI J. Optoelectron. Adv. Mater. PD NOV PY 2007 VL 9 IS 11 BP 3522 EP 3528 PG 7 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA 238GK UT WOS:000251435200048 ER PT J AU Hall, TM Haine, TWN Holzer, M Lebel, DA Terenzi, F Waugh, DW AF Hall, Timothy M. Haine, Thomas W. N. Holzer, Mark Lebel, Deborah A. Terenzi, Francesca Waugh, Darryn W. TI Ventilation rates estimated from tracers in the presence of mixing SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID LABRADOR SEA-WATER; NORTH-ATLANTIC; CFC INVENTORIES; OCEAN INTERIOR; TRANSIT-TIME; SURFACE HEAT; MODEL; CIRCULATION; AGE; DISTRIBUTIONS AB The intimate relationship among ventilation, transit-time distributions, and transient tracer budgets is analyzed. To characterize the advective-diffusive transport from the mixed layer to the interior ocean in terms of flux we employ a cumulative ventilation-rate distribution, Phi(tau), defined as the one-way mass flux of water that resides at least time tau in the interior before returning. A one-way (or gross) flux contrasts with the net advective flux, often called the subduction rate, which does not accommodate the effects of mixing, and it contrasts with the formation rate, which depends only on the net effects of advection and diffusive mixing. As tau decreases Phi(tau) increases, encompassing progressively more one-way flux. In general, Phi is a rapidly varying function of tau( it diverges at small tau), and there is no single residence time at which Phi can be evaluated to fully summarize the advective-diffusive flux. To reconcile discrepancies between estimates of formation rates in a recent GCM study, Phi(tau) is used. Then chlorofluorocarbon data are used to bound Phi(tau) for Subtropical Mode Water and Labrador Sea Water in the North Atlantic Ocean. The authors show that the neglect of diffusive mixing leads to spurious behavior, such as apparent time dependence in the formation, even when transport is steady. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Haine, Thomas W. N.; Waugh, Darryn W.] Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. [Holzer, Mark; Terenzi, Francesca] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. [Lebel, Deborah A.] Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY USA. RP Hall, TM (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM thall@giss.nasa.gov RI Waugh, Darryn/K-3688-2016 OI Waugh, Darryn/0000-0001-7692-2798 NR 31 TC 13 Z9 13 U1 2 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD NOV PY 2007 VL 37 IS 11 BP 2599 EP 2611 DI 10.1175/2006JPO3471.1 PG 13 WC Oceanography SC Oceanography GA 242QW UT WOS:000251741600002 ER PT J AU Polzin, KA Markusic, TE AF Polzin, Kurt A. Markusic, Thomas E. TI Electromagnetic pumps for liquid metal-fed electric thrusters SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID PROPULSION; FLOW AB Prototype designs of two separate pumps for use in electric propulsions systems with liquid lithium and bismuth propellants are presented. Both pumps are required to operate at elevated temperatures, and the lithium pump must additionally withstand the corrosive nature of the propellant. Compatibility of the pump materials and seals with lithium and bismuth were demonstrated through proof-of-concept experiments followed by postexperiment visual inspections. The pressure rise produced by the bismuth pump was found to be linear with input current and ranged from 0-9 kPa for corresponding input current levels of 0-30 A, showing good quantitative agreement with theoretical analysis. C1 NASA, Marshall Space Flight Ctr, Propuls Syst Dept, Nucl Syst Branch, Huntsville, AL 35812 USA. RP Polzin, KA (reprint author), NASA, Marshall Space Flight Ctr, Propuls Syst Dept, Nucl Syst Branch, Huntsville, AL 35812 USA. EM kurt.a.polzin@nasa.gov NR 18 TC 3 Z9 3 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD NOV-DEC PY 2007 VL 23 IS 6 BP 1285 EP 1290 DI 10.2514/1.30819 PG 6 WC Engineering, Aerospace SC Engineering GA 231HD UT WOS:000250936400016 ER PT J AU Forbes, JM Bruinsma, S Lemoine, FG Bowman, BR Konopliv, A AF Forbes, Jeffrey M. Bruinsma, Sean Lemoine, Frank G. Bowman, Bruce R. Konopliv, Alex TI Satellite drag variability at Earth, Mars, and Venus due to solar rotation SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 21-24, 2006 CL Keystone, CO SP AIAA, AAS ID TERRESTRIAL PLANET THERMOSPHERES; CYCLE VARIATION; MODEL AB Thermosphere densities from precise orbit determination of Mars Global Surveyor, Pioneer Venus Orbiter, and Magellan are used with contemporaneous data from six Earth-orbiting satellites to investigate the responses of these planetary satellite drag environments to changes in solar flux due to the sun's rotation. For comparative purposes, these results are cast in the form of equivalent exosphere temperature variations. Per 10-unit change in 10.7-cm radioflux (used as a proxy for extreme ultraviolet flux) reaching each planet, we find temperature changes of 20.6,7.0, and 2.0 K for Earth, Mars, and Venus, respectively. The different responses are thought to reflect the differing efficiencies Of CO(2) cooling and extreme ultraviolet heating in these upper atmospheres, and thus provide an important constraint on planetary atmosphere models that seek to self-consistently and interconsistently simulate the thermospheres of these planets. Our results also provide new data for empirical density models that are used to predict the satellite drag environments of these planets. C1 [Forbes, Jeffrey M.] Univ Colorado, Dept Aerosp Engn Sci, UCB 429, Boulder, CO 80309 USA. [Bruinsma, Sean] Ctr Natl Etud Spatiales, Dept Terr & Planetary Geodesy, F-31401 Toulouse, France. [Lemoine, Frank G.] NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab Code 698, Greenbelt, MD 20771 USA. [Bowman, Bruce R.] USAF, Space Anal Div A9A, Colorado Springs, CO 80914 USA. [Konopliv, Alex] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Forbes, JM (reprint author), Univ Colorado, Dept Aerosp Engn Sci, UCB 429, Boulder, CO 80309 USA. RI Lemoine, Frank/D-1215-2013; OI FORBES, JEFFREY/0000-0001-6937-0796 NR 15 TC 2 Z9 2 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD NOV-DEC PY 2007 VL 44 IS 6 BP 1160 EP 1164 DI 10.2514/1.28013 PG 5 WC Engineering, Aerospace SC Engineering GA 241JN UT WOS:000251652800003 ER PT J AU Mazarico, E Zuber, MT Lemoine, FG Smith, DE AF Mazarico, Erwan Zuber, Maria T. Lemoine, Frank G. Smith, David E. TI Atmospheric density during the aerobraking of mars odyssey from radio tracking data SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 21-24, 2006 CL Keystone, CO SP AIAA, AAS ID GLOBAL SURVEYOR; ACCELEROMETER; THERMOSPHERE; GRAVITY; MODEL AB We analyzed X-band radio tracking observations of the Mars Odyssey spacecraft during its aerobraking phase (October 2001-January 2002). Using the precision orbit determination software GEODYN, we obtained estimates of the spacecraft orbital energy lost during each periapsis pass due to atmospheric drag. We also recovered atmospheric density values at each periapsis, assuming simple exponential atmospheric models. Our measurements are in good agreement with the time series from the Odyssey accelerometer instrument, but they are dependent on the a priori scale height used. Using the accelerometer-derived periapsis densities and the precision orbit determination-derived frictional loss of orbital energy, we calculated new scale heights. Each represents the effective scale height of the atmosphere near periapsis for each aerobraking pass. Our results are consistently approximate to 1.7 +/- 0.7 km greater than the published accelerometer values. The accelerometer measurements have higher spatial and temporal resolution when they are available, but these results provide a data set useful for engineering and navigational purposes, to assess variability in the Martian middle atmosphere. C1 [Mazarico, Erwan; Zuber, Maria T.] MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. [Lemoine, Frank G.; Smith, David E.] NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP Mazarico, E (reprint author), MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Lemoine, Frank/D-1215-2013; Mazarico, Erwan/N-6034-2014 OI Mazarico, Erwan/0000-0003-3456-427X NR 23 TC 3 Z9 5 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD NOV-DEC PY 2007 VL 44 IS 6 BP 1165 EP 1171 DI 10.2514/1.28448 PG 7 WC Engineering, Aerospace SC Engineering GA 241JN UT WOS:000251652800004 ER PT J AU Tolson, RH Keating, GM Zurek, RW Bougher, SW Justus, CG Fritts, DC AF Tolson, R. H. Keating, G. M. Zurek, R. W. Bougher, S. W. Justus, C. G. Fritts, D. C. TI Application of accelerometer data to atmospheric modeling dunring mars aerobraking operations SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 21-24, 2006 CL Keystone, CO SP AIAA, AAS ID GLOBAL SURVEYOR; THERMAL TIDES AB This paper reviews the use of accelerometer data for determining atmospheric density during aerobraking operations of the Mars Global Survey, Mars Odyssey, and Mars Reconnaissance Orbiter missions. For all three missions, accelerometer data were analyzed in near real time to provide estimates of thermospheric density, density scale height, latitudinal gradients, global longitudinal wave structure, and small-scale (gravity) wave spectra. Mars Global Survey, Mars Odyssey, and Mars Reconnaissance Orbiter provided data during approximately 850,320, and 425 passes covering latitude ranges of 60 degrees N to 90 degrees S, 30 degrees N to 90 degrees N, and 0 to 90 degrees S, respectively. Periapsis altitudes varied from 95 to 130 km. A summary is given of the atmospheric phenomena encountered during the aerobraking phase of the missions and of some of the scientific results based on these data. C1 [Tolson, R. H.] N Carolina State Univ, Hampton, VA 23666 USA. [Keating, G. M.] George Washington Univ, Newport News, VA 23602 USA. [Zurek, R. W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Bougher, S. W.] Univ Michigan, Phys Res Lab, Ann Arbor, MI 48109 USA. [Justus, C. G.] Morgan Res Corp, Huntsville, AL 35805 USA. [Fritts, D. C.] NW Res Associates Inc, Colorado Res Associates Div, Boulder, CO 80301 USA. RP Tolson, RH (reprint author), N Carolina State Univ, Hampton, VA 23666 USA. RI Bougher, Stephen/C-1913-2013 OI Bougher, Stephen/0000-0002-4178-2729 NR 22 TC 16 Z9 18 U1 0 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD NOV-DEC PY 2007 VL 44 IS 6 BP 1172 EP 1179 DI 10.2514/1.28472 PG 8 WC Engineering, Aerospace SC Engineering GA 241JN UT WOS:000251652800005 ER PT J AU Baird, DT Tolson, R Bougher, S Steers, B AF Baird, Darren T. Tolson, Robert Bougher, Stephen Steers, Brian TI Zonal wind calculations from Mars Global Surveyor accelerometer and rate data SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 21-24, 2006 CL Keystone, CO SP AIAA, AAS AB The Mars Global Surveyor spacecraft was initially placed into a high-eccentricity, nearly polar orbit about Mars with a 45-h period. To accomplish the science objectives of the mission, a 2-h circular orbit was required. Using a method known as aerobraking, numerous passes through the upper atmosphere slowed the spacecraft, thereby reducing the orbital period and eccentricity. To successfully perform aerobraking, the spacecraft was designed to be longitudinally, aerodynamically stable in pitch and yaw. Because the orbit was nearly polar, the yaw orientation of the spacecraft was sensitive to disturbances caused by the zonal components of wind (east to west or west to east) acting on the spacecraft at aerobraking altitudes. Zonal wind velocities were computed by equating the aerodynamic and inertia-related torques acting on the spacecraft. Comparisons of calculated zonal winds with those computed from the Mars thermospheric general-circulation model are discussed. C1 [Baird, Darren T.] CALTECH, Jet Prop Lab, Guidance Navigat & Control Sect, Pasadena, CA 91109 USA. [Tolson, Robert] N Carolina State Univ, Ctr Planetary Atmospher & Flight Sci, Hampton, VA 23666 USA. [Bougher, Stephen; Steers, Brian] Univ Michigan, Space Phys Res Lab, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. RP Baird, DT (reprint author), CALTECH, Jet Prop Lab, Guidance Navigat & Control Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Bougher, Stephen/C-1913-2013 OI Bougher, Stephen/0000-0002-4178-2729 NR 10 TC 8 Z9 8 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD NOV-DEC PY 2007 VL 44 IS 6 BP 1180 EP 1187 DI 10.2514/1.28588 PG 8 WC Engineering, Aerospace SC Engineering GA 241JN UT WOS:000251652800006 ER PT J AU Liechty, DS AF Liechty, Derek S. TI Aeroheating analysis for the Mars Reconnaissance Orbiter with comparison to flight data SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 21-24, 2006 CL Keystone, CO SP AIAA, AAS ID SIMULATION AB The aeroheating environment of the Mars Reconnaissance Orbiter has been analyzed using the direct simulation Monte Carlo and free-molecular techniques. The results of these analyses were used to develop an aeroheating database to be used for the preflight planning and the in-flight operations support for the aerobraking phase of the Mars Reconnaissance Orbiter mission. The aeroheating predictions calculated for the Mars Reconnaissance Orbiter include the heat transfer coefficient (CH) over a range of angles of attack, side-slip angles, and number densities. The effects of flow chemistry, surface temperature, and surface grid resolution were also investigated to determine the aeroheating database uncertainties. Flight heat flux data has been calculated from surface temperature sensor data returned to Earth from the Mars Reconnaissance Orbiter in orbit around Mars during the aerobraking phase of its mission. The heat flux data have been compared with the aeroheating database and agree favorably. C1 NASA, Langley Res Ctr, Aerothermodynam Branch, Hampton, VA 23681 USA. RP Liechty, DS (reprint author), NASA, Langley Res Ctr, Aerothermodynam Branch, Hampton, VA 23681 USA. NR 7 TC 5 Z9 6 U1 1 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD NOV-DEC PY 2007 VL 44 IS 6 BP 1226 EP 1231 DI 10.2514/1.25843 PG 6 WC Engineering, Aerospace SC Engineering GA 241JN UT WOS:000251652800012 ER PT J AU Spencer, DA Tolson, R AF Spencer, David A. Tolson, Robert TI Aerobraking cost and risk decisions SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 21-24, 2006 CL Keystone, CO SP AIAA, AAS ID MARS ODYSSEY AEROBRAKING; MAGELLAN AB Four missions have successfully employed aerobraking at Venus and Mars to reduce the spacecraft orbit period and achieve the desired orbit geometry. The propellant mass reductions enabled by the aerobraking technique allow the use of smaller launch systems, which translate to significant savings in launch costs for flight projects. However, there is a significant increase in mission risk associated with the use of aerobraking. Flying a spacecraft through a planetary atmosphere hundreds of times during months of around-the-clock operations places the spacecraft in harm's way, and is extraordinarily demanding on the flight team. There is a cost/risk trade that must be evaluated when a project is choosing between a mission baseline that includes aerobraking, or selecting a larger launch vehicle to enable purely propulsive orbit insertion. This paper provides a brief history of past and future aerobraking missions, describes the aerobraking technique, summarizes the costs associated with aerobraking, and concludes with a suggested methodology for evaluating the cost/risk trade when considering the aerobraking approach. C1 [Spencer, David A.] CALTECH, Jet Prop Lab, Phoenix Project, Pasadena, CA 91109 USA. [Tolson, Robert] N Carolina State Univ, Natl Inst Aerosp, Hampton, VA 23666 USA. RP Spencer, DA (reprint author), CALTECH, Jet Prop Lab, Phoenix Project, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 9 Z9 12 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD NOV-DEC PY 2007 VL 44 IS 6 BP 1285 EP 1293 DI 10.2514/1.24303 PG 9 WC Engineering, Aerospace SC Engineering GA 241JN UT WOS:000251652800018 ER PT J AU Liu, J Dehlinger, J Lutz, R AF Liu, Jing Dehlinger, Josh Lutz, Robyn TI Safety analysis of software product lines using state-based modeling SO JOURNAL OF SYSTEMS AND SOFTWARE LA English DT Article; Proceedings Paper CT 16th International Symposium on Software Reliability Engineering CY NOV 08-11, 2005 CL Chicago, IL SP IEEE Comp Soc, Reliabil Soc DE product lines; safety-critical systems; model-based development; state-based modeling ID FAMILY; REUSE AB The difficulty of managing variations and their potential interactions across an entire product line currently hinders safety analysis in safety-critical, software product lines. The work described here contributes to a solution by integrating product-line safety analysis with model-based development. This approach provides a structured way to construct state-based models of a product line having significant, safety-related variations and to systematically explore the relationships between behavioral variations and potential hazardous states through scenario-guided executions of the state model over the variations. The paper uses a product line of safety-critical medical devices to demonstrate and evaluate the technique and results. (C) 2007 Elsevier Inc. All rights reserved. C1 Iowa State Univ, Dept Comp Sci, Ames, IA 50011 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Liu, J (reprint author), Iowa State Univ, Dept Comp Sci, Ames, IA 50011 USA. NR 33 TC 25 Z9 25 U1 0 U2 6 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0164-1212 EI 1873-1228 J9 J SYST SOFTWARE JI J. Syst. Softw. PD NOV PY 2007 VL 80 IS 11 BP 1879 EP 1892 DI 10.1016/j.jss.2007.01.047 PG 14 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 224FU UT WOS:000250433700009 ER PT J AU Liu, Y Koutrakis, P Kahn, R AF Liu, Yang Koutrakis, Petros Kahn, Ralph TI Estimating fine particulate matter component concentrations and size distributions using satellite-retrieved fractional aerosol optical depth: Part 1 - Method development SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID LIGHT-SCATTERING CHARACTERISTICS; IMAGING SPECTRORADIOMETER MISR; CONTIGUOUS UNITED-STATES; GROUND-LEVEL PM2.5; RELATIVE-HUMIDITY; PARTICLES; THICKNESS; AMBIENT; OCEAN; SENSITIVITY AB We develop a method that uses both the total column aerosol optical depth (AOD) and the fractional AOD values for different aerosol types, derived from Multiangle Imaging SpectroRadiometer (MISR) aerosol data, to estimate ground-level concentrations of fine particulate matter (PM2.5) mass and its major constituents in eastern and western United States. Compared with previous research on linking column AOD with ground-level PM2.5, this method treats various MISR aerosol components as individual predictor variables. Therefore, the contributions of different particle types to PM2.5 concentrations can be estimated. When AOD is greater than 0.15, MISR is able to distinguish dust from non-dust particles with an uncertainty level of approximately 4%, and light-absorbing from non-light-absorbing particles with an uncertainty level of approximately 20%. Further analysis shows that MISR Version 17 aerosol microphysical properties have good sensitivity and internal consistency among different mixture classes. The retrieval uncertainty of individual fractional AODs ranges between 5 and 11% in the eastern United States, and between 11 and 31% in the west for non-dust aerosol components. These results provide confidence that the fractional AOD models with their inherent flexibility can make more accurate predictions of the concentrations of PM2.5 and its constituents. C1 Harvard Univ, Sch Publ Hlth, Boston, MA 02215 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Liu, Y (reprint author), Harvard Univ, Sch Publ Hlth, Boston, MA 02215 USA. EM yangliu@hsph.harvard.edu RI Kahn, Ralph/D-5371-2012; Wang, Linden/M-6617-2014 OI Kahn, Ralph/0000-0002-5234-6359; NR 27 TC 42 Z9 44 U1 3 U2 25 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1096-2247 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD NOV PY 2007 VL 57 IS 11 BP 1351 EP 1359 DI 10.3155/1047-3289.S7.11.1351 PG 9 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 228YL UT WOS:000250768400007 PM 18069458 ER PT J AU Liu, Y Koutrakis, P Kahn, R Turquety, S Yantosca, RM AF Liu, Yang Koutrakis, Petros Kahn, Ralph Turquety, Solene Yantosca, Robert M. TI Estimating fine particulate matter component concentrations and size distributions using satellite-retrieved fractional aerosol optical depth: Part 2 - A case study SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID GROUND-LEVEL PM2.5; UNITED-STATES; AIR-QUALITY; US CITIES; NITRATE; THICKNESS; POLLUTION; SULFATES; MODIS; SITE AB We use the fractional aerosol optical depth (AOD) values derived from Multiangle Imaging Spectroradiometer (MISR) aerosol component measurements,. along with aerosol transport model constraints, to estimate ground-level concentrations of fine particulate matter (PM2.5) mass and its major constituents in the continental United States. Regression models using fractional AODs predict PM2.5 mass and sulfate (SO4) concentrations in both the eastern and western United States, and nitrate (NO3) concentrations in the western United States reasonably well, compared with the available ground-level U.S. Environment Protection Agency (EPA) measurements. These models show substantially improved predictive power when compared with similar models. using total-column AOD as a single predictor, especially in the western United States. The relative contributions of the MISR aerosol components in these regression models are used to estimate size distributions of EPA PM2.5 species. This method captures the overall shapes of the size distributions of PM2.5 mass and SO4 particles in the east and west, and NO3 particles in the west. However, the estimated PM2.5 and SO4 mode diameters are smaller than those previously reported by monitoring studies conducted at ground level. This is likely due to the satellite sampling bias caused by the inability to retrieve aerosols through cloud cover, and the impact of particle hygroscopicity on measured particle size distributions at ground level. C1 Harvard Univ, Sch Publ Hlth, Boston, MA 02215 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Harvard Div Engn & Appl Sci, Cambridge, MA USA. RP Liu, Y (reprint author), Harvard Univ, Sch Publ Hlth, Boston, MA 02215 USA. EM yangliu@hsph.harvard.edu RI Yantosca, Robert/F-7920-2014; Kahn, Ralph/D-5371-2012 OI Yantosca, Robert/0000-0003-3781-1870; Kahn, Ralph/0000-0002-5234-6359 NR 22 TC 44 Z9 45 U1 1 U2 24 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD NOV PY 2007 VL 57 IS 11 BP 1360 EP 1369 DI 10.3155/1047-3289.57.11.1360 PG 10 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 228YL UT WOS:000250768400008 PM 18069459 ER PT J AU Errico, RM Ohring, G Bauer, P Ferrier, B Mahfouf, JF Turk, J Weng, F AF Errico, Ronald M. Ohring, George Bauer, Peter Ferrier, Brad Mahfouf, Jean-Francois Turk, Joe Weng, Fuzhong TI Assimilation of satellite cloud and precipitation observations in numerical weather prediction models: Introduction to the JAS special collection SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Editorial Material AB To date, the assimilation of satellite measurements in numerical weather prediction (NWP) models has focused on the clear atmosphere. But satellite observations in the visible, infrared, and microwave provide a great deal of information on clouds and precipitation. This special collection describes how to use this information to initialize clouds and precipitation in models. Since clouds and precipitation often occur in sensitive regions for forecast impacts, such improvements are likely necessary for continuing to acquire significant gains in weather forecasting. This special collection of the Journal of the Atmospheric Sciences is devoted to articles based on papers presented at the International Workshop on Assimilation of Satellite Cloud and Precipitation Observations in Numerical Weather Prediction Models, in Lansdowne, Virginia, in May 2005. This introduction summarizes the findings of the workshop. The special collection includes review articles on satellite observations of clouds and precipitation (Stephens and Kummerow), parameterizations of clouds and precipitation in NWP models (Lopez), radiative transfer in cloudy/precipitating atmospheres (Weng), and assimilation of cloud and precipitation observations (Errico et al.),as well as research papers on these topics. C1 Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, NESDIS, Ctr Satellite Applicat & Res, Camp Springs, MD USA. European Ctr Medium Range Weather Forescasts, Reading, Berks, England. NOAA, NWS, Natl Ctr Environm Predict, Sci Applicat Int Corp, Camp Springs, MD USA. Meteorol Serv Canada, Dorval, PQ, Canada. Naval Res Lab, Monterey, CA USA. RP Ohring, G (reprint author), NOAA, NESDIS, Room 808,5200 Auth Rd, Camp Springs, MD 20746 USA. EM george.ohring@noaa.gov RI Ohring, George/F-5616-2010; Weng, Fuzhong/F-5633-2010 OI Weng, Fuzhong/0000-0003-0150-2179 NR 0 TC 16 Z9 21 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD NOV PY 2007 VL 64 IS 11 BP 3737 EP 3741 DI 10.1175/2007JAS2622.1 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 236DK UT WOS:000251283000001 ER PT J AU Errico, RM Bauer, P Mahfouf, JF AF Errico, Ronald M. Bauer, Peter Mahfouf, Jean-Francois TI Issues regarding the assimilation of cloud and precipitation data SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article; Proceedings Paper CT International Workshop on Assimilation of Satellite Cloud and Precipitation Obervations in Numerical Weather Prediction Models CY MAY, 2005 CL Lansdowne, VA ID VARIATIONAL DATA ASSIMILATION; MICROWAVE RADIATIVE-TRANSFER; ENSEMBLE-PREDICTION SYSTEM; GLOBAL SPECTRAL MODEL; LIMITED-AREA MODEL; COLUMN WATER-VAPOR; LARGE-SCALE MODELS; INITIAL CONDITIONS; DIABATIC INITIALIZATION; 1D+4D-VAR ASSIMILATION AB The assimilation of observations indicative of quantitative cloud and precipitation characteristics is desirable for improving weather forecasts. For many fundamental reasons, it is a more difficult problem than the assimilation of conventional or clear-sky satellite radiance data. These reasons include concerns regarding nonlinearity of the required observation operators ( forward models), nonnormality and large variances of representativeness, retrieval, or observation-operator errors, validation using new measures, dynamic and thermodynamic balances, and possibly limited predictability. Some operational weather prediction systems already assimilate precipitation observations, but much more research and development remains. The apparently critical, fundamental, and peculiar nature of many issues regarding cloud and precipitation assimilation implies that their more careful examination will be required for accelerating progress. C1 Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. Natl Aeronaut & Space Adm, Global Modeling & Assimilat Off, Greenbelt, MD USA. European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England. Environm Canada, Dorval, PQ, Canada. RP Errico, RM (reprint author), NASA, Goddard Space Flight Ctr, Global Modleing & Assimilat Off, Code 6101, Greenbelt, MD 20771 USA. EM rerrico@gmao.gsfc.nasa.gov NR 100 TC 55 Z9 58 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD NOV PY 2007 VL 64 IS 11 BP 3785 EP 3798 DI 10.1175/2006JAS2044.1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 236DK UT WOS:000251283000004 ER PT J AU Yue, Q Liou, KN Ou, SC Kahn, BH Yang, P Mace, GG AF Yue, Qing Liou, K. N. Ou, S. C. Kahn, B. H. Yang, P. Mace, G. G. TI Interpretation of AIRS data in thin cirrus atmospheres based on a fast radiative transfer model SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article; Proceedings Paper CT International Workshop on Assimilation of Satellite Cloud and Precipitation Obervations in Numerical Weather Prediction Models CY MAY, 2005 CL Lansdowne, VA ID ACCURATE TRANSMITTANCE MODEL; SINGLE-SCATTERING PROPERTIES; VARIABLE MIXING RATIOS; INFRARED SOUNDER AIRS; ICE CRYSTAL SIZE; ABSORBING GAS; COMPUTATIONALLY FAST; CLOUD STATISTICS; WATER-VAPOR; PARAMETERIZATION AB A thin cirrus cloud thermal infrared radiative transfer model has been developed for application to cloudy satellite data assimilation. This radiation model was constructed by combining the Optical Path Transmittance (OPTRAN) model, developed for the speedy calculation of transmittances in clear atmospheres, and a thin cirrus cloud parameterization using a number of observed ice crystal size and shape distributions. Numerical simulations show that cirrus cloudy radiances in the 800-1130-cm(-1) thermal infrared window are sufficiently sensitive to variations in cirrus optical depth and ice crystal size as well as in ice crystal shape if appropriate habit distribution models are selected a priori for analysis. The parameterization model has been applied to the Atmospheric Infrared Sounder ( AIRS) on board the Aqua satellite to interpret clear and thin cirrus spectra observed in the thermal infrared window. Five clear and 29 thin cirrus cases at nighttime over and near the Atmospheric Radiation Measurement program ( ARM) tropical western Pacific (TWP) Manus Island and Nauru Island sites have been chosen for this study. A chi(2)-minimization program was employed to infer the cirrus optical depth and ice crystal size and shape from the observed AIRS spectra. Independent validation shows that the AIRS-inferred cloud parameters are consistent with those determined from collocated ground-based millimeter-wave cloud radar measurements. The coupled thin cirrus radiative transfer parameterization and OPTRAN, if combined with a reliable thin cirrus detection scheme, can be effectively used to enhance the AIRS data volume for data assimilation in numerical weather prediction models. C1 Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. RP Yue, Q (reprint author), Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, 405 Hilgard Ave, Los Angeles, CA 90095 USA. EM qingyue@atmos.ucla.edu RI Yang, Ping/B-4590-2011; Yue, Qing/A-5776-2013; Yue, Qing/F-4619-2017 OI Yue, Qing/0000-0002-3559-6508 NR 46 TC 19 Z9 19 U1 2 U2 2 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 NOV PY 2007 VL 64 IS 11 BP 3827 EP 3842 DI 10.1175/2007JAS2043.1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 236DK UT WOS:000251283000007 ER PT J AU Hou, AY Zhang, SQ AF Hou, Arthur Y. Zhang, Sara Q. TI Assimilation of precipitation information using column model physics as a weak constraint SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article; Proceedings Paper CT International Workshop on Assimilation of Satellite Cloud and Precipitation Obervations in Numerical Weather Prediction Models CY MAY, 2005 CL Lansdowne, VA ID RAIN RATES; RETRIEVAL; FORECASTS; CLIMATE; 4D-VAR; CLOUD; ECMWF; TRMM; TMI AB Currently, operational weather forecasting systems use observations to optimize the initial state of a forecast without considering possible model deficiencies. For precipitation assimilation, this could be an issue since precipitation observations, unlike conventional data, do not directly provide information on the atmospheric state but are related to the state variables through parameterized moist physics with simplifying assumptions. Precipitation observation operators are comparatively less accurate than those for conventional data or observables in clear-sky regions, which can limit data usage not because of issues with observations, but with the model. The challenge lies in exploring new ways to make effective use of precipitation data in the presence of model errors. This study continues the investigation of variational algorithms for precipitation assimilation using column model physics as a weak constraint. The strategy is to develop techniques to make online estimation and correction of model errors to improve the precipitation observation operator during the assimilation cycle. Earlier studies have shown that variational continuous assimilation (VCA) of tropical rainfall using moisture tendency correction can improve Goddard Earth Observing System 3 (GEOS-3) global analyses and forecasts. Here results are presented from a 4-yr GEOS-3 reanalysis assimilating Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Special Sensor Microwave Imager (SSM/I) tropical rainfall using the VCA scheme. Comparisons with NCEP operational analysis and the 40-yr EC-MWF Re-Analysis (ERA-40) show that the GEOS-3 reanalysis is significantly better at replicating the intensity and variability of tropical precipitation systems ranging from a few days to interannual time scales. As a further refinement of rainfall assimilation using the VCA scheme, a variational algorithm for assimilating TMI latent heating retrievals using semiempirical parameters in the model moist physics as control variables is described and initial test results are presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zhang, SQ (reprint author), NASA, Goddard Space Flight Ctr, Code 6101, Greenbelt, MD 20771 USA. EM arthur.y.hou@nasa.gov RI Hou, Arthur/D-8578-2012 NR 23 TC 11 Z9 11 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD NOV PY 2007 VL 64 IS 11 BP 3865 EP 3879 DI 10.1175/2006JAS2028.1 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 236DK UT WOS:000251283000010 ER PT J AU Norris, PM Da Silva, AM AF Norris, Peter M. Da Silva, Arlindo M. TI Assimilation of satellite cloud data into the GMAO finite-volume data assimilation system using a parameter estimation method. Part I: Motivation and algorithm description SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article; Proceedings Paper CT International Workshop on Assimilation of Satellite Cloud and Precipitation Obervations in Numerical Weather Prediction Models CY MAY, 2005 CL Lansdowne, VA ID OVERLAP; SCHEME; MODELS; COVER AB General circulation models are unable to resolve subgrid-scale moisture variability and associated cloudiness and so must parameterize grid-scale cloud properties. This typically involves various empirical assumptions and a failure to capture the full range ( synoptic, geographic, diurnal) of the subgrid-scale variability. A variational parameter estimation technique is employed to adjust empirical model cloud parameters in both space and time, in order to better represent assimilated International Satellite Cloud Climatology Project (ISCCP) cloud fraction and optical depth and Special Sensor Microwave Imager (SSM/I) liquid water path. The value of these adjustments is verified by much improved cloud radiative forcing and persistent improvement in cloud fraction forecasts. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. RP Norris, PM (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 6101, Greenbelt, MD 20771 USA. EM peter.m.norris@nasa.gov RI da Silva, Arlindo/D-6301-2012; Norris, Peter/H-2008-2012 OI da Silva, Arlindo/0000-0002-3381-4030; Norris, Peter/0000-0001-6807-9884 NR 19 TC 11 Z9 11 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD NOV PY 2007 VL 64 IS 11 BP 3880 EP 3895 DI 10.1175/2006JAS2046.1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 236DK UT WOS:000251283000011 ER PT J AU Mukherjee, P Kang, MG Zurbuchen, TH Guo, LJ Herrero, FA AF Mukherjee, Pran Kang, Myung-Gyu Zurbuchen, Thomas H. Guo, L. Jay Herrero, Fred A. TI Fabrication of high aspect ratio Si nanogratings with smooth sidewalls for a deep UV-blocking particle filter SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 51st International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication CY MAY 29-JUN 01, 2007 CL Denver, CO ID FREESTANDING TRANSMISSION GRATINGS; ULTRAVIOLET AB To measure space plasmas and neutral particles one must filter out high-energy ultraviolet photons that would increase background count or damage sensors. To enable sensitive neutral particle measurements, a photon-to-particle rejection rate of 10(14) is desired, far exceeding the requirements of prior filters. The authors propose a high-aspect ratio Si grating with densely packed, sub-100 nm slits. In this article, the authors report the development of a new technique for fabricating sturdy, self-supported transmission gratings in silicon using nanoimprint lithography and deep reactive ion etching, resulting in grating slits with scalloping under 7 nm and high (8.5:1) aspect ratios. C1 [Mukherjee, Pran; Kang, Myung-Gyu; Zurbuchen, Thomas H.; Guo, L. Jay] Univ Michigan, Ann Arbor, MI 48109 USA. [Herrero, Fred A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mukherjee, P (reprint author), Univ Michigan, Ann Arbor, MI 48109 USA. EM pran@umich.edu NR 9 TC 9 Z9 10 U1 0 U2 12 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV PY 2007 VL 25 IS 6 BP 2645 EP 2648 DI 10.1116/1.2804612 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 240UA UT WOS:000251611900176 ER PT J AU Kumar, SV Doby, TA Baugh, JW Brill, ED Ranjithan, SR AF Kumar, Sujay V. Doby, Troy A. Baugh, John W., Jr. Brill, E. Downey Ranjithan, S. Ranji TI Closure to "Optimal design of redundant water distribution networks using a cluster of workstations" by Sujay V. Kumar, Troy A. Doby, John W. Baugh Jr., E. Downey Brill, and S. Ranji Ranjithan SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Editorial Material C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. US EPA, NRMRL, Sustainable Technol Div, Syst Analy Branch, Cincinnati, OH 45268 USA. N Carolina State Univ, Raleigh, NC 27695 USA. RP Kumar, SV (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. EM sujay@hsb.gsfc.nasa.gov; doby.troy@epamail.epa.gov; jwb@ncsu.edu; brill@ncsu.edu; ranji@ncsu.edu RI Kumar, Sujay/B-8142-2015 NR 1 TC 0 Z9 0 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD NOV-DEC PY 2007 VL 133 IS 6 BP 580 EP 581 DI 10.1061/(ASCE)0733-9496(2007)132:5(374) PG 2 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA 222SP UT WOS:000250317800021 ER PT J AU Wigforss-Lange, J Vajda, V Ocampo, A AF Wigforss-Lange, Jane Vajda, Vivi Ocampo, Adriana TI Trace element concentrations in the Mexico-Belize ejecta layer: A link between the Chicxulub impact and the global Cretaceous-Paleogene boundary SO METEORITICS & PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Impact Craters as Indicators for Planetary Environmental Evolution and Astrobiology CY JUN, 2006 CL Ostersund, SWEDEN ID RARE-EARTH-ELEMENTS; TERTIARY BOUNDARY; ALBION ISLAND; YUCATAN PENINSULA; STEVNS-KLINT; NEW-ZEALAND; K/T IMPACT; CRATER; CONSTRAINTS; EVENT AB Four exposures of Chicxulub impact ejecta along the Mexico-Belize border have been sampled and analyzed for major and trace element abundances. The ejecta deposits consist of a lower spheroid bed, containing clay and dolomite spheroids, and an upper diamictite bed with boulders and clasts of limestone and dolomite. The matrix of both beds is composed of clay and micritic dolomite. The rare earth element (REE) compositions in the matrix of both units show strong similarities in concentrations and pattern. Furthermore, the Zr/TiO2 scatter plot shows a linear correlation indicating one source. These results indicate that the basal spheroid bed has the same source and was generated during the same event as the overlying diamictite bed, which lends support to a single-impact scenario for the Albion Formation ejecta deposits. The elevated concentrations of non-meteoritic elements such as Sb, As, U, and Zn in the matrix of the lower spheroid bed are regarded to have been derived from the sedimentary target rocks at the Chicxulub impact site. The positive Eu and Ce anomalies in clay concretion and in the matrix of the lower part of the spheroid bed in Albion Island quarry is probably related to processes involved in the impact, such as high temperature and oxidizing conditions. Analogous trace element anomalies have been reported from the distal Cretaceous-Paleogene (K/T) boundary clay layer at different sites. Thus, the trace element signals, reported herein, are regarded to support a genetic link between the Chicxulub impact, the ejecta deposits along the Mexico-Belize border, and the global K/T boundary layer. C1 [Wigforss-Lange, Jane; Vajda, Vivi] Lund Univ, Dept Geol, GeoBiosphere Sci Ctr, S-22362 Lund, Sweden. [Ocampo, Adriana] NASA HQ, Sci Miss Directorate, Washington, DC 20546 USA. RP Wigforss-Lange, J (reprint author), Lund Univ, Dept Geol, GeoBiosphere Sci Ctr, S-22362 Lund, Sweden. EM Jane.Wigforss-Lange@geol.lu.se OI Vajda, Vivi/0000-0003-2987-5559 NR 61 TC 9 Z9 10 U1 0 U2 6 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 2007 VL 42 IS 11 BP 1871 EP 1882 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 273NM UT WOS:000253937700003 ER PT J AU Conselice, CJ Bundy, K Trujillo, I Coil, A Eisenhardt, P Ellis, RS Georgakakis, A Huang, J Lotz, J Nandra, K Newman, J Papovich, C Weiner, B Willmer, C AF Conselice, C. J. Bundy, K. Trujillo, I. Coil, A. Eisenhardt, P. Ellis, R. S. Georgakakis, A. Huang, J. Lotz, J. Nandra, K. Newman, J. Papovich, C. Weiner, B. Willmer, C. TI The properties and evolution of a K-band selected sample of massive galaxies at z similar to 0.4-2 in the Palomar/DEEP2 survey SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Review DE galaxies : evolution; galaxies : formation; galaxies : structure ID STAR-FORMING GALAXIES; HUBBLE-SPACE-TELESCOPE; HIGH-REDSHIFT GALAXIES; DEEP-FIELD-NORTH; SPECTRAL ENERGY-DISTRIBUTION; LYMAN BREAK GALAXIES; DISTANT RED GALAXIES; STELLAR MASS; LUMINOSITY FUNCTION; BILLION YEARS AB We present the results of a study on the properties and evolution of massive ( M-* > 10(11)M circle dot) galaxies at z similar to 0.4 - 2 utilizing Keck spectroscopy, near- infrared Palomar imaging, and Hubble, Chandra and Spitzer data covering fields targeted by the DEEP2 galaxy spectroscopic survey. Our sample is K- band selected and stellar mass limited, based on wide- area near- infrared imaging from the Palomar Observatory Wide- Field Infrared Survey, which covers 1.53 deg(2) to a 5 sigma depth of K-s,K-vega similar to 20.5. Our primary goal is to obtain a broad census of massive galaxies through measuring how their number and mass densities, morphology, as well as their star formation and active galactic nucleus content evolve from z similar to 0.4 - 2. Our major findings include: ( i) statistically the mass and number densities of M-* > 10(11)M circle dot galaxies show little evolution between z = 0 and 1 and from z similar to 0 to 2 for M-* > 10(11.5)M circle dot galaxies. We however find significant evolution within 1 < z < 1.5 for 10(11) M circle dot < M-* < 10(11.5)M circle dot galaxies. ( ii) After examining the structures of our galaxies using Hubble ACS imaging, we find that M-* > 1011M circle dot selected galaxies show a nearly constant elliptical fraction of similar to 70 - 90 per cent at all redshifts. The remaining objects tend to be peculiars possibly undergoing mergers at z > 0.8, while spirals dominate the remainder at lower redshifts. A significant fraction (similar to 25 per cent) of these early- types contain minor structural anomalies. ( iii) We find that only a fraction (similar to 60 per cent) of massive galaxies with M-* > 10(11)M circle dot are on the red sequence at z similar to 1.4, while nearly 100 per cent evolve on to it by z similar to 0.4. ( iv) By utilizing Spitzer MIPS imaging and [ O II] line fluxes we argue that M-* > 1011.5M circle dot galaxies have a steeply declining star formation rate ( SFR) density similar to ( 1 + z) (6). By examining the contribution of star formation to the evolution of the mass function, as well as the merger history through the CAS parameters, we determine that M-* > 10(11)M circle dot galaxies undergo on average 0.9+(0.7)(-0.5) - 0.5 major mergers at 0.4 < z < 1.4. ( v) We find that a high ( 5 per cent) fraction of all M-* > 10(11)M circle dot galaxies are X- ray emitters. Roughly half of these are morphologically distorted ellipticals or peculiars. Finally, we compare our mass growth with semi- analytical models from the Millennium Simulation, finding relative good agreement at z < 2 for the M-* < 10(11.5)M circle dot systems, but that the number and mass densities of M* > 10(11.5)M circle dot galaxies are underpredicted by a factor of > 100. C1 Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England. Univ Toronto, Dept Astron, Toronto, ON, Canada. Univ Arizona, Steward Observ, Tucson, AZ USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. Univ London Imperial Coll Sci Technol & Med, London, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Opt Astron Observ, Tucson, AZ USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Maryland, College Pk, MD 20742 USA. RP Conselice, CJ (reprint author), Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England. EM conselice@nottingham.ac.uk RI Conselice, Christopher/B-4348-2013; Georgakakis, Antonis/K-4457-2013; OI Conselice, Christopher/0000-0003-1949-7638 NR 120 TC 100 Z9 100 U1 1 U2 3 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 1 PY 2007 VL 381 IS 3 BP 962 EP 986 DI 10.1111/j.1365-2966.2007.12316.x PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 223IH UT WOS:000250363000006 ER PT J AU Hong, Y Adler, R Verdin, J AF Hong, Yang Adler, Robert Verdin, James TI Use of 21st century satellite remote sensing technology in natural hazard analysis SO NATURAL HAZARDS LA English DT Editorial Material C1 NASA, Goddard Space Flight Ctr, GSFC, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. US Geol Survey, EROS Data Ctr, Sioux Falls, SD USA. RP Hong, Y (reprint author), NASA, Goddard Space Flight Ctr, GSFC, Code 6131, Greenbelt, MD 20771 USA. EM yanghong@agnes.gsfc.nasa.gov RI Hong, Yang/D-5132-2009 OI Hong, Yang/0000-0001-8720-242X NR 0 TC 4 Z9 4 U1 0 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0921-030X J9 NAT HAZARDS JI Nat. Hazards PD NOV PY 2007 VL 43 IS 2 BP 165 EP 166 DI 10.1007/s11069-007-9133-2 PG 2 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA 217ZS UT WOS:000249986400001 ER PT J AU Hossain, F Katiyar, N Hong, Y Wolf, A AF Hossain, Faisal Katiyar, Nitin Hong, Yang Wolf, Aaron TI The emerging role of satellite rainfall data in improving the hydro-political situation of flood monitoring in the under-developed regions of the world SO NATURAL HAZARDS LA English DT Article DE flood monitoring; satellite remote sensing; precipitation; international river basins; forecasting; hydrologic modeling; decision support tools ID PREDICTION; SYSTEM AB The systematic decline of in situ networks for hydrologic measurements has been recognized as a crucial limitation to advancing hydrologic monitoring in medium to large basins, especially those that are already sparsely instrumented. As a collective response, sections of the hydrologic community have recently forged partnerships for the development of space-borne missions for cost-effective, yet global, hydrologic measurements by building upon the technological advancements since the last two decades. In this article, we review the state-of-the-art on flood monitoring in medium and large ungauged basins where satellite remote sensing can facilitate development of a cost-effective mechanism. We present our review in the context of the current hydro-political situation of flood monitoring in flood-prone developing nations situated in international river basins (IRBs). Given the large number of such basins and the difficulty in acquisition of multi-faceted geophysical data, we argue that the conventional data-intensive implementation of physically based hydrologic models that are complex and distributed is time-consuming for global assessment of the utility of proposed global satellite hydrologic missions. A more parsimonious approach is justified at the tolerable expense of accuracy before such missions begin operation. Such a parsimonious approach can subsequently motivate the identified international basins to invest greater effort in conventional and detailed hydrologic studies to design a prototype flood forecasting system in an effort to overcome the hydro-political hurdles to flood monitoring. Through a modeling exercise involving an open-book watershed concept, we demonstrate the value of a parsimonious approach in understanding the utility of NASA-derived satellite rainfall products. It is critical now that real-world operational flood forecasting agencies in the under-developed world come forward to collaborate with the research community in order to leverage satellite rainfall data for greater societal benefit for inhabitants in IRBs. C1 Tennessee Technol Univ, Dept Civil & Environm Engn, Cookeville, TN 38505 USA. NASA, Goddard Space Flight Ctr, UMBC, GEST, Greenbelt, MD 20771 USA. Oregon State Univ, Dept Geosci, Corvallis, OR 97331 USA. RP Hossain, F (reprint author), Tennessee Technol Univ, Dept Civil & Environm Engn, 1020 Staduim Dr,Box 5015, Cookeville, TN 38505 USA. EM fhossain@tntech.edu; yanghong@agnes.gsfc.nasa.gov; wolfa@oregonstate.edu RI Hong, Yang/D-5132-2009; Wolf, Aaron/A-6717-2011 OI Hong, Yang/0000-0001-8720-242X; NR 26 TC 19 Z9 20 U1 0 U2 11 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0921-030X J9 NAT HAZARDS JI Nat. Hazards PD NOV PY 2007 VL 43 IS 2 BP 199 EP 210 DI 10.1007/s11069-006-9094-x PG 12 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA 217ZS UT WOS:000249986400004 ER PT J AU Lu, GY Chiu, LS Wong, DW AF Lu, George Y. Chiu, Long S. Wong, David W. TI Vulnerability assessment of rainfall-induced debris flows in Taiwan SO NATURAL HAZARDS LA English DT Article DE debris flow; spatial interpolation; susceptibility; vulnerability assessment; decision support system; satellite rainfall ID ARTIFICIAL NEURAL-NETWORK; MOUNTAINOUS TERRAIN; PRECIPITATION ESTIMATION; SPATIAL INTERPOLATION; HAZARD ASSESSMENT; BRITISH-COLUMBIA; MODEL; LANDSLIDES; ELEVATION; IMPACT AB A GIS-based decision support system, which incorporates local topographic and rainfall effects on debris flow vulnerability is developed. Rainfall at a scale compatible with the digital elevation model resolution is obtained using a neural network with a wind-induced topographic effect and rainfall derived from satellite rain estimates and an adaptive inverse distance weight method (WTNN). The technique is tested using data collected during the passage of typhoon Tori-Ji on July 2001 over central Taiwan. Numerous debris flows triggered by the typhoon were used as control for the study. Our results show that the WTNN technique outperforms other interpolation techniques including adaptive inversed distance weight (AIDW), simple kriging (SK), co-kriging, and multiple linear regression using gauge, and topographic parameters. Multiple remotely-sensed, fuzzy-based debris-flow susceptibility parameters are used to describe the characteristics of watersheds. Non-linear, multi-variant regressions using the WTNN derived rainfall and topography factors are derived using self-organizing maps (SOM) for the debris flow vulnerability assessment. An index of vulnerability representing the degrees of hazard is implemented in a GIS-based decision support system by which a decision maker can assess debris flow vulnerability. C1 George Mason Univ, Coll Sci, Dept Earth Syst & Geoinformat Sci, Fairfax, VA 22030 USA. NASA, Goddard Space Flight Ctr, Data & Informat Serv Ctr, Greenbelt, MD 20771 USA. RP Lu, GY (reprint author), George Mason Univ, Coll Sci, Dept Earth Syst & Geoinformat Sci, Fairfax, VA 22030 USA. EM glu@gmu.edu OI /0000-0002-0525-0071 NR 66 TC 16 Z9 17 U1 1 U2 13 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0921-030X J9 NAT HAZARDS JI Nat. Hazards PD NOV PY 2007 VL 43 IS 2 BP 223 EP 244 DI 10.1007/s11069-006-9105-y PG 22 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA 217ZS UT WOS:000249986400006 ER PT J AU Hong, Y Adler, R Huffman, G AF Hong, Yang Adler, Robert Huffman, George TI Use of satellite remote sensing data in the mapping of global landslide susceptibility SO NATURAL HAZARDS LA English DT Article DE satellite remote sensing; landslide susceptibility; GIS ID RAINFALL INTENSITY; HAZARD EVALUATION; PUERTO-RICO; GIS; ZONATION; HIMALAYAS AB Satellite remote sensing data has significant potential use in analysis of natural hazards such as landslides. Relying on the recent advances in satellite remote sensing and geographic information system (GIS) techniques, this paper aims to map landslide susceptibility over most of the globe using a GIS-based weighted linear combination method. First, six relevant landslide-controlling factors are derived from geospatial remote sensing data and coded into a GIS system. Next, continuous susceptibility values from low to high are assigned to each of the six factors. Second, a continuous scale of a global landslide susceptibility index is derived using GIS weighted linear combination based on each factor's relative significance to the process of landslide occurrence (e.g., slope is the most important factor, soil types and soil texture are also primary-level parameters, while elevation, land cover types, and drainage density are secondary in importance). Finally, the continuous index map is further classified into six susceptibility categories. Results show the hot spots of landslide-prone regions include the Pacific Rim, the Himalayas and South Asia, Rocky Mountains, Appalachian Mountains, Alps, and parts of the Middle East and Africa. India, China, Nepal, Japan, the USA, and Peru are shown to have landslide-prone areas. This first-cut global landslide susceptibility map forms a starting point to provide a global view of landslide risks and may be used in conjunction with satellite-based precipitation information to potentially detect areas with significant landslide potential due to heavy rainfall. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth & Sci Technol Ctr, Baltimore, MD 21228 USA. Sci Syst Appl Inc, Greenbelt, MD 20771 USA. RP Hong, Y (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Mail Code 6131, 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 22 TC 64 Z9 65 U1 4 U2 46 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0921-030X J9 NAT HAZARDS JI Nat. Hazards PD NOV PY 2007 VL 43 IS 2 BP 245 EP 256 DI 10.1007/s11069-006-9104-z PG 12 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA 217ZS UT WOS:000249986400007 ER PT J AU Jin, ML Shepherd, JM Peters-Lidard, C AF Jin, Menglin Shepherd, J. Marshall Peters-Lidard, Christa TI Development of a parameterization for simulating the urban temperature hazard using satellite observations in climate model SO NATURAL HAZARDS LA English DT Article DE urban system; surface temperature hazard; climate modeling ID SKIN TEMPERATURE; HEAT-ISLAND; MODIS; AREAS; ALGORITHM; HOUSTON; CLOUD AB Urban surface temperature is hazardously higher than surrounding regions (so-called urban heat island effect UHI). Accurately simulating urbanization-induced temperature hazard is critical for realistically representing urban regions in the land surface-atmosphere climate system. However, inclusion of urban landscapes in regional or global climate models has been overlooked due to the coarse spatial resolution of these models as well as the lack of observations for urban physical properties. Recently, National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS) observations illustrate important urban physical properties, including skin temperature, surface albedo, surface emissivity, and leaf area index, It is possible to identify the unique urban features globally and thus simulate global urban processes. An urban scheme is designed to represent the urban-modified physical parameters (albedo, emissivity, land cover, roughness length, thermal and hydraulic properties) and to include new, unique physical processes that exist in urban regions. The urban scheme is coupled with National Center for Atmospheric Research (NCAR) Community Land Model Version 2 (CLM2) and single column coupled NCAR Community Atmosphere Model CAM2/CLM2 to assess the mechanisms responsible for UHI. There are two-steps in our model development. First, satellite observations of albedo, emissivity, LAI, and in situ observed thermal properties are updated in CLM2 to represent the first-order urban effects. Second, new terms representing the urban anthropogenic heat flux, storage heat flux, and roughness length are calculated in the model. Model simulations suggest that human activity-induced surface temperature hazard results in overlying atmosphere instability and convective rainfall, which may enhance the possibility of urban flood hazard. C1 Univ Maryland, NASA, Goddard Space Flight Ctr, Dept Meteorol, Greenbelt, MD 20771 USA. Univ Georgia, Dept Geog, Atmospher Sci Programme, Athens, GA 30602 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Jin, ML (reprint author), Univ Maryland, NASA, Goddard Space Flight Ctr, Dept Meteorol, Code 6122, Coll Pk, Greenbelt, MD 20771 USA. EM mjin@atmos.umd.edu RI Peters-Lidard, Christa/E-1429-2012 OI Peters-Lidard, Christa/0000-0003-1255-2876 NR 38 TC 18 Z9 18 U1 0 U2 9 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0921-030X J9 NAT HAZARDS JI Nat. Hazards PD NOV PY 2007 VL 43 IS 2 BP 257 EP 271 DI 10.1007/s11069-007-9117-2 PG 15 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA 217ZS UT WOS:000249986400008 ER PT J AU Hong, Y Adler, RF Negri, A Huffman, GJ AF Hong, Yang Adler, Robert F. Negri, Andrew Huffman, George J. TI Flood and landslide applications of near real-time satellite rainfall products SO NATURAL HAZARDS LA English DT Article DE satellite remote sensing; precipitation; flood; landslide ID INTENSITY; SYSTEM AB Floods and associated landslides account for the largest number of natural disasters and affect more people than any other type of natural disaster. With the availability of satellite rainfall analyses at fine time and space resolution, it has also become possible to mitigate such hazards on a near-global basis. In this article, a framework to detect floods and landslides related to heavy rain events in near-real-time is proposed. Key components of the framework are: a fine resolution precipitation acquisition system; a comprehensive land surface database; a hydrological modeling component; and landslide and debris flow model components. A key precipitation input dataset for the integrated applications is the NASA TRMM-based multi-satellite precipitation estimates. This dataset provides near real-time precipitation at a spatial-temporal resolution of 3 h and 0.25 degrees x 0.25 degrees. In combination with global land surface datasets it is now possible to expand regional hazard modeling components into a global identification/monitoring system for flood/landslide disaster preparedness and mitigation. C1 NASA, Atmospheres Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. UMBC, Goddard Earth & Sci Technol Ctr, Baltimore, MD 20440 USA. Sci Syst & Applicat Inc, Greenbelt, MD USA. RP Hong, Y (reprint author), NASA, Atmospheres Lab, 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 22 TC 55 Z9 58 U1 6 U2 30 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0921-030X J9 NAT HAZARDS JI Nat. Hazards PD NOV PY 2007 VL 43 IS 2 BP 285 EP 294 DI 10.1007/s11069-006-9106-x PG 10 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA 217ZS UT WOS:000249986400010 ER PT J AU Yamakov, VI Glaessgen, EH AF Yamakov, Vesselin I. Glaessgen, Edward H. TI To twin or not to twin SO NATURE MATERIALS LA English DT News Item ID MOLECULAR-DYNAMICS SIMULATION; NANOCRYSTALLINE ALUMINUM; DEFORMATION; FRACTURE; AL C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Yamakov, VI (reprint author), Natl Inst Aerosp, Hampton, VA 23666 USA. EM yamakov@nianet.org; edward.h.glaessgen@nasa.gov NR 9 TC 11 Z9 11 U1 0 U2 24 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1476-1122 J9 NAT MATER JI Nat. Mater. PD NOV PY 2007 VL 6 IS 11 BP 795 EP 796 DI 10.1038/nmat2041 PG 2 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 226VA UT WOS:000250615400008 PM 17972926 ER PT J AU Black, JK Baker, RG Deines-Jones, P Hill, JE Jahoda, K AF Black, J. K. Baker, R. G. Deines-Jones, P. Hill, J. E. Jahoda, K. TI X-ray polarimetry with a micropattern TPC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE X-ray polarimetry; particle tracking; GEM; TPC; pixel readout ID SIMULATION AB The micropattern time projection chamber (TPC) offers a novel method of imaging the tracks of photoelectrons as a means of X-ray polarimetry with the potential to simultaneously achieve large modulation factors and high quantum efficiency. Measurements with a simple prototype micropattern TPC polarimeter, with an 18 mm-atm absorption depth of a mixture of 50% neon and 50% dimethyl ether, result in a modulation factor of 45.0 +/- 0.6% with polarized 6.4keV X-rays. With unpolarized 5.9keV X-rays, the measured modulation factor is 0.49 +/- 0.54%, consistent with zero. The geometry of the TPC polarimeter will enable substantial improvements in quantum efficiency without the loss of modulation. (c) 2007 Elsevier B.V. All rights reserved. C1 Rock Creek Sci, Silver Spring, MD 20910 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. CRESST, Greenbelt, MD 20771 USA. RP Black, JK (reprint author), Rock Creek Sci, 1400 East West Hwy,Suite 807, Silver Spring, MD 20910 USA. EM black@rockcreekscientific.com RI Jahoda, Keith/D-5616-2012 NR 12 TC 46 Z9 46 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 2007 VL 581 IS 3 BP 755 EP 760 DI 10.1016/j.nima.2007.08.144 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 234GF UT WOS:000251148000018 ER PT J AU Herrin, ET Rosenbaum, DC Teplitz, VL AF Herrin, Eugene T. Rosenbaum, Doris C. Teplitz, Vigdor L. TI Using the Moon as a strange quark nugget detector SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Proceedings Paper CT 7th UCLA Symposium on Sources and Detection of Dark Matter and Dark Energy in the Universe CY FEB 22-24, 2006 CL Marina del Rey, CA SP UCLA ID SEISMOGRAPHIC STATION REPORTS; UNEXPLAINED SETS; NUCLEARITES; CONSISTENT; PASSAGE AB We review the romance and mystery of strange quark matter (SQM), including: its basics, our recent work on bounds on the abundance of ton-range strange quark nuggets (SQNs) from Earth seismology, potential SQN bounds from a possible seismic search on the Moon, and our recent bounds on SQNs in the 10 kilogram to ton range from the data of Apollo-implanted seismometers. Finally, we speculate a bit on using the sun or the solar system to detect passage of SQNs of much greater mass than the aforementioned. C1 [Herrin, Eugene T.] So Methodist Univ, Dept Geol, Dallas, TX 75275 USA. [Rosenbaum, Doris C.] So Methodist Univ, Dept Phys, Dallas, TX 75275 USA. [Teplitz, Vigdor L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Herrin, ET (reprint author), So Methodist Univ, Dept Geol, Dallas, TX 75275 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD NOV PY 2007 VL 173 BP 72 EP 74 DI 10.1016/j.nuclphysbps.2007.08.030 PG 3 WC Physics, Particles & Fields SC Physics GA 250JN UT WOS:000252296100018 ER PT J AU Norton, GV AF Norton, Guy V. TI Finite-difference time-domain simulation of acoustic propagation in heterogeneous dispersive medium SO NUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS LA English DT Article DE acoustic; causality; dispersion; finite-difference time-domain ID INCLUDING DISPERSION; ATTENUATION; EQUATIONS; WAVES AB Accurate modeling of pulse propagation and scattering is a problem in many disciplines (i.e., electromagnetics and acoustics). It is even more tenuous when the medium is dispersive. Blackstock [D. T. Blackstock, J Acoust Soc Am 77 (1985) 2050] first proposed a theory that resulted in adding an additional term (the derivative of the convolution between the causal time-domain propagation factor and the acoustic pressure) that takes into account the dispersive nature of the medium. Thus deriving a modified wave equation applicable to either linear or nonlinear propagation. For the case of an acoustic wave propagating in a two-dimensional heterogeneous dispersive medium, a finite-difference time-domain representation of the modified linear wave equation can been used to solve for the acoustic pressure. The method is applied to the case of scattering from and propagating through a 2-D infinitely long cylinder with the properties of fat tissue encapsulating a cyst. It is found that ignoring the heterogeneity in the medium can lead to significant error in the propagated/scattered field. (c) 2007 Wiley Periodicals, Inc. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. RP Norton, GV (reprint author), USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. EM guy.norton@nrlssc.navy.mil NR 14 TC 5 Z9 5 U1 0 U2 1 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0749-159X J9 NUMER METH PART D E JI Numer. Meth. Part Differ. Equ. PD NOV PY 2007 VL 23 IS 6 BP 1420 EP 1428 DI 10.1002/num.20231 PG 9 WC Mathematics, Applied SC Mathematics GA 221WB UT WOS:000250257000009 ER PT J AU Herren, KA Gregory, DA AF Herren, Kenneth A. Gregory, Don A. TI Bidirectional reflectance distribution function measurement of molecular contaminants in the ultraviolet, vacuum ultraviolet, and visible ranges SO OPTICAL ENGINEERING LA English DT Article DE scattering; BRDF; VUV; contamination; molecular contamination ID SCATTERING; SURFACE AB Bidirectional reflectance distribution function measurements of optical surfaces both before and after molecular contamination have been done using UV, VUV, and visible light. Molecular contamination of optical surfaces from outgassed material has been shown in many cases to proceed from acclimation centers, and to produce many roughly hemispherical "islands" of contamination on the surface. The products of this outgassing will inevitably migrate throughout the surrounding area and adhere to any convenient surface, including optical elements in the system. (c) 2007 Society of Photo-Optical Instrumentation Engineers. C1 [Herren, Kenneth A.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Gregory, Don A.] Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP Herren, KA (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU SPIE-SOC PHOTOPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD NOV PY 2007 VL 46 IS 11 AR 113601 DI 10.1117/1.2802140 PG 8 WC Optics SC Optics GA 239WP UT WOS:000251549300005 ER PT J AU Koch, GJ Beyon, JY Barnes, BW Petros, M Yu, J Amzajerdian, F Kavaya, MJ Singh, UN AF Koch, Grady J. Beyon, Jeffrey Y. Barnes, Bruce W. Petros, Mulugeta Yu, Jirong Amzajerdian, Farzin Kavaya, Michael J. Singh, Upendra N. TI High-energy 2 mu m Doppler lidar for wind measurements SO OPTICAL ENGINEERING LA English DT Article DE lidar; lasers; meteorology; signal processing ID LASERS; SYSTEM AB A coherent Doppler lidar at 2 mu m wavelength has been built with higher output energy (100 mJ) than previously available. The laser transmitter is based on diode-pumped Ho:Tm:LuLiF, a recently developed laser material that allows more efficient energy extraction. Single-frequency operation is achieved by a ramp-and-fire injection seeding technique. An advanced photodetector architecture is used incorporating photodiodes in a dual-balanced configuration. A digital signal processing system has been built, allowing real-time display of wind and aerosol backscatter data products. The high pulse energy and receiver efficiency provides for measurement of wind fields to ranges not seen before with 2 mu m lidars, and example wind measurements were made to show this capability. (c) 2007 Society of Photo-Optical Instrumentation Engineers. C1 [Koch, Grady J.; Barnes, Bruce W.; Yu, Jirong; Amzajerdian, Farzin; Kavaya, Michael J.; Singh, Upendra N.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Beyon, Jeffrey Y.] Calif State Univ Los Angeles, Dept Elect & Comp Engn, Los Angeles, CA 90032 USA. [Petros, Mulugeta] Sci & Technol Corp, Hampton, VA 23666 USA. RP Koch, GJ (reprint author), NASA, Langley Res Ctr, MS 468, Hampton, VA 23681 USA. EM grady.j.koch@nasa.gov NR 28 TC 51 Z9 60 U1 7 U2 29 PU SPIE-SOC PHOTOPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD NOV PY 2007 VL 46 IS 11 AR 116201 DI 10.1117/1.2802584 PG 14 WC Optics SC Optics GA 239WP UT WOS:000251549300033 ER PT J AU Strekalov, DV Matsko, AB Yu, N AF Strekalov, Dmitry V. Matsko, Andrey B. Yu, Nan TI Electromagnetically induced transparency with a partially standing drive field SO PHYSICAL REVIEW A LA English DT Article ID REFLECTION; LIGHT; VAPOR AB We study electromagnetically induced transparency in a vacuum rubidium atomic cell and show that reflected drive radiation results in the reshaping and shift of dark resonance. We show that those effects are connected with (i) Bragg reflection of the probe radiation in optically thick atomic coherent medium modulated by the standing-wave drive field, as well as with (ii) quantum interference enhanced absorption of the probe radiation in four-level N-configuration formed due to the reflected drive field. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Strekalov, DV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Matsko, Andrey/A-1272-2007 NR 20 TC 11 Z9 11 U1 0 U2 1 PU AMER 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 NOV PY 2007 VL 76 IS 5 AR 053828 DI 10.1103/PhysRevA.76.053828 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 236TN UT WOS:000251326400167 ER PT J AU Zhang, W Mingo, N Fisher, TS AF Zhang, W. Mingo, N. Fisher, T. S. TI Simulation of phonon transport across a non-polar nanowire junction using an atomistic Green's function method SO PHYSICAL REVIEW B LA English DT Article ID LATTICE THERMAL-CONDUCTIVITY; SILICON NANOWIRE; INTERATOMIC POTENTIALS; NANOSTRUCTURES; WIRE AB Phonon transport across a non-polar nanowire situated between two semi-infinite contacts is simulated in this paper using the atomistic Green's function method. Abrupt geometric changes between the nanowire and bulk contacts are handled by self-energy matrices obtained from bare surface Green's functions. Transport properties such as phonon transmission functions and thermal conductances are calculated, and their dependencies on the interatomic potential, length, diameter, shape, and lattice orientation are investigated. The results reveal that the overall thermal conductance of the nanowire-bulk-contact structure increases with nanowire diameter while the normalized thermal conductance approaches an asymptotic value. Thermal conductance decreases significantly with increasing nanowire length and converges to that of the single-contact case. This method can be generalized to study phonon transport through a variety of nanostructures between bulk contacts. C1 [Zhang, W.; Fisher, T. S.] Purdue Univ, Birck Nanotechnol Ctr, Nanoscale Thermofluids Lab, W Lafayette, IN 47907 USA. [Mingo, N.] NASA, Ames Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Fisher, TS (reprint author), Purdue Univ, Birck Nanotechnol Ctr, Nanoscale Thermofluids Lab, W Lafayette, IN 47907 USA. EM tsfisher@purdue.edu RI Fisher, Timothy/D-8517-2011 OI Fisher, Timothy/0000-0002-8909-313X NR 35 TC 47 Z9 47 U1 1 U2 7 PU AMER 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 NOV PY 2007 VL 76 IS 19 AR 195429 DI 10.1103/PhysRevB.76.195429 PG 9 WC Physics, Condensed Matter SC Physics GA 236TR UT WOS:000251326800134 ER PT J AU Buonanno, A Pan, Y Baker, JG Centrella, J Kelly, BJ McWilliams, ST van Meter, JR AF Buonanno, Alessandra Pan, Yi Baker, John G. Centrella, Joan Kelly, Bernard J. McWilliams, Sean T. van Meter, James R. TI Approaching faithful templates for nonspinning binary black holes using the effective-one-body approach SO PHYSICAL REVIEW D LA English DT Article ID INSPIRALING COMPACT BINARIES; POST-NEWTONIAN DYNAMICS; QUASI-NORMAL MODES; GRAVITATIONAL-RADIATION; LASER-INTERFEROMETER; CLOSE-LIMIT; MASS; ORDER; WAVES; COLLISION AB We present an accurate approximation of the full gravitational radiation waveforms generated in the merger of noneccentric systems of two nonspinning black holes. Utilizing information from recent numerical relativity simulations and the natural flexibility of the effective-one-body (EOB) model, we extend the latter so that it can successfully match the numerical relativity waveforms during the last stages of inspiral, merger, and ringdown. By "successfully" here, we mean with phase differences less than or similar to 8% of a gravitational-wave cycle accumulated by the end of the ringdown phase, maximizing only over time of arrival and initial phase. We obtain this result by simply adding a 4-post-Newtonian order correction in the EOB radial potential and determining the (constant) coefficient by imposing high-matching performances with numerical waveforms of mass ratios m(1)/m(2)=1, 3/2, 2 and 4, m(1) and m(2) being the individual black-hole masses. The final black-hole mass and spin predicted by the numerical simulations are used to determine the ringdown frequency and decay time of three quasinormal-mode damped sinusoids that are attached to the EOB inspiral-(plunge) waveform at the EOB light ring. The EOB waveforms might be tested and further improved in the future by comparison with extremely long and accurate inspiral numerical relativity waveforms. They may be already employed for coherent searches and parameter estimation of gravitational waves emitted by nonspinning coalescing binary black holes with ground-based laser-interferometer detectors. C1 Univ Maryland, Dept Phys, Maryland Ctr Fundamental Phys, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Ctr Space Sci & Technol, Dept Phys, Baltimore, MD 21250 USA. RP Buonanno, A (reprint author), Univ Maryland, Dept Phys, Maryland Ctr Fundamental Phys, College Pk, MD 20742 USA. RI van meter, james/E-7893-2011; Kelly, Bernard/G-7371-2011 NR 83 TC 190 Z9 191 U1 0 U2 5 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 NOV PY 2007 VL 76 IS 10 AR 104049 DI 10.1103/PhysRevD.76.104049 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 236TX UT WOS:000251327400094 ER PT J AU Choi, DI Kelly, BJ Boggs, WD Baker, JG Centrella, J van Meter, J AF Choi, Dae-Il Kelly, Bernard J. Boggs, William D. Baker, John G. Centrella, Joan van Meter, James TI Recoiling from a kick in the head-on collision of spinning black holes SO PHYSICAL REVIEW D LA English DT Article ID GRAVITATIONAL-RADIATION RECOIL; 3-DIMENSIONAL CARTESIAN GRIDS; COALESCING BINARY-SYSTEMS; ADAPTIVE MESH REFINEMENT; APPARENT-HORIZON FINDER; NUMERICAL RELATIVITY; COMPACT OBJECTS; STAR-CLUSTERS; INITIAL DATA; MERGER AB Recoil "kicks" induced by gravitational radiation are expected in the inspiral and merger of black holes. Recently the numerical relativity community has begun to measure the significant kicks found when both unequal masses and spins are considered. Because understanding the cause and magnitude of each component of this kick may be complicated in inspiral simulations, we consider these effects in the context of a simple test problem. We study recoils from collisions of binaries with initially head-on trajectories, starting with the simplest case of equal masses with no spin and then adding spin and varying the mass ratio, both separately and jointly. We find spin-induced recoils to be significant relative to unequal-mass recoils even in head-on configurations. Additionally, it appears that the scaling of transverse kicks with spins is consistent with post-Newtonian theory, even though the kick is generated in the nonlinear merger interaction, where post-Newtonian theory should not apply. This suggests that a simple heuristic description might be effective in the estimation of spin kicks. C1 NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. Korea Inst Sci & Technol Informat, Taejon 305806, South Korea. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Choi, DI (reprint author), NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. RI van meter, james/E-7893-2011; Kelly, Bernard/G-7371-2011; OI Kelly, Bernard/0000-0002-3326-4454 NR 79 TC 31 Z9 31 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 NOV PY 2007 VL 76 IS 10 AR 104026 DI 10.1103/PhysRevD.76.104026 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 236TX UT WOS:000251327400071 ER PT J AU Cutler, C Vallisneri, M AF Cutler, Curt Vallisneri, Michele TI LISA detections of massive black hole inspirals: Parameter extraction errors due to inaccurate template waveforms SO PHYSICAL REVIEW D LA English DT Article ID POST-NEWTONIAN EXPANSION; GRAVITATIONAL-WAVES; COMPACT BINARIES; CIRCULAR ORBIT; PARTICLE; RADIATION; OBJECTS AB The planned Laser Interferometer Space Antenna (LISA) is expected to detect the inspiral and merger of massive black hole binaries (MBHBs) at z less than or similar to 5 with signal-to-noise ratios (SNRs) of hundreds to thousands. Because of these high SNRs, and because these SNRs accrete over periods of weeks to months, it should be possible to extract the physical parameters of these systems with high accuracy; for instance, for a similar to 10(6)M(circle dot) MBHBs at z=1 it should be possible to determine the two masses to similar to 0.1% and the sky location to similar to 1 degrees. However, those are just the errors due to noise: there will be additional "theoretical" errors due to inaccuracies in our best model waveforms, which are still only approximate. The goal of this paper is to estimate the typical magnitude of these theoretical errors. We develop mathematical tools for this purpose, and apply them to a somewhat simplified version of the MBHB problem, in which we consider just the inspiral part of the waveform and neglect spin-induced precession, eccentricity, and PN amplitude corrections. For this simplified version, we estimate that theoretical uncertainties in sky position will typically be similar to 1 degrees, i.e., comparable to the statistical uncertainty. For the mass and spin parameters, our results suggest that while theoretical errors will be rather small absolutely, they could still dominate over statistical errors (by roughly an order of magnitude) for the strongest sources. The tools developed here should be useful for estimating the magnitude of theoretical errors in many other problems in gravitational-wave astronomy. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cutler, C (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 56 TC 71 Z9 71 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 J9 PHYS REV D JI Phys. Rev. D PD NOV PY 2007 VL 76 IS 10 AR 104018 DI 10.1103/PhysRevD.76.104018 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 236TX UT WOS:000251327400063 ER PT J AU Hesse, M Zenitani, S AF Hesse, Michael Zenitani, Seiji TI Dissipation in relativistic pair-plasma reconnection SO PHYSICS OF PLASMAS LA English DT Article ID COLLISIONLESS MAGNETIC RECONNECTION; PARTICLE SIMULATIONS; GRB OUTFLOWS; PULSAR WIND; FLUX; ACCELERATION; LINE AB An investigation into the relativistic dissipation in magnetic reconnection is presented. The investigated system consists of an electron-positron plasma. A relativistic generalization of Ohm's law is derived. A set of numerical simulations is analyzed, composed of runs with and without guide magnetic field, and of runs with different species temperatures. The calculations indicate that the thermal inertia-based dissipation process survives in relativistic plasmas. For antiparallel reconnection, it is found that the pressure tensor divergence remains the sole contributor to the reconnection electric field, whereas relativistic guide field reconnection exhibits a similarly important role of the bulk inertia terms.(C) 2007 American Institute of Physics. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hesse, M (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Hesse, Michael/D-2031-2012; Zenitani, Seiji/D-7988-2013; NASA MMS, Science Team/J-5393-2013 OI Zenitani, Seiji/0000-0002-0945-1815; NASA MMS, Science Team/0000-0002-9504-5214 NR 25 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 NOV PY 2007 VL 14 IS 11 AR 112102 DI 10.1063/1.2801482 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 236TH UT WOS:000251325800007 ER PT J AU Atkinson, DH Kazerninejad, B Lebreton, JP Witasse, O Perez-Ayucar, M Matson, DL AF Atkinson, David H. Kazerninejad, Bobby Lebreton, Jean-Pierre Witasse, Olivier Perez-Ayucar, Miguel Matson, Dennis L. TI The Huygens probe descent trajectory working group: Organizational framework, goals, and implementation SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Cassim/Huygens mission; entry and descent trajectory reconstruction ID MARS PATHFINDER; MISSION; SCIENCE; TITAN; ENTRY; PAYLOAD AB Cassini/Huygens, a flagship mission to explore the rings, atmosphere, magnetic field, and moons that make up the Saturn system, is a joint endeavor of the National Aeronautics and Space Administration, the European Space Agency, and Agenzia Spaziale Italiana. Comprising two spacecraft-a Saturn orbiter built by NASA and a Titan entry/descent probe built by the European Space Agency-Cassini/Huygens was launched in October 1997. The Huygens probe parachuted to the surface of Titan in January 2005. During the descent, six science instruments provided in situ measurements of Titan's atmosphere, clouds, and winds, and photographed Titan's surface. To correctly interpret and correlate results from the probe science experiments, and to provide a reference set of data for ground-truth calibration of orbiter remote sensing measurements, an accurate reconstruction of the probe entry and descent trajectory and surface landing location is necessary. The Huygens Descent Trajectory Working Group was chartered in 1996 as a subgroup of the Huygens Science Working Team to develop and implement an organizational framework and retrieval methodologies for the probe descent trajectory reconstruction from the entry altitude of 1270 km to the surface using navigation data, and engineering and science data acquired by the instruments on the Huygens Probe. This paper presents an overview of the Descent Trajectory Working Group, including the history, rationale, goals and objectives, organizational framework, rules and procedures, and implementation. (c) 2007 Elsevier Ltd. All rights reserved. C1 Univ Idaho, Dept Elect & Comp Engn, Moscow, ID 83844 USA. German Space Operat Ctr, Deutsches Zentrum Luft & Raumfahrt, D-82234 Wesling, Germany. European Space Agcy, ESTEC, Res & Sci Support Dept, NL-2200 AG Noordwijk, Netherlands. Jet Propuls Lab, Pasadena, CA 91109 USA. RP Atkinson, DH (reprint author), Univ Idaho, Dept Elect & Comp Engn, Moscow, ID 83844 USA. EM atkinson@ece.uidaho.edu NR 17 TC 3 Z9 3 U1 0 U2 4 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 NOV PY 2007 VL 55 IS 13 BP 1877 EP 1885 DI 10.1016/j.pss.2007.04.004 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235AQ UT WOS:000251206300003 ER PT J AU Soderblom, LA Kirk, RL Lunine, JI Anderson, JA Baines, KH Barnes, JW Barrett, JM Brown, RH Buratti, BJ Clark, RN Crulkshank, DP Elachi, C Janssen, MA Jaumann, R Karkoschka, E Le Mouelic, S Lopes, RM Lorenz, RD McCord, TB Nicholson, PD Radebaugh, J Rizk, B Sotin, C Stofan, ER Sucharski, TL Tomasko, MG Wall, SD AF Soderblom, Laurence A. Kirk, Randolph L. Lunine, Jonathan I. Anderson, Jeffrey A. Baines, Kevin H. Barnes, Jason W. Barrett, Janet M. Brown, Robert H. Buratti, Bonnie J. Clark, Roger N. Crulkshank, Dale P. Elachi, Charles Janssen, Michael A. Jaumann, Ralf Karkoschka, Erich Le Mouelic, Stehane Lopes, Rosaly M. Lorenz, Ralph D. McCord, Thomas B. Nicholson, Philip D. Radebaugh, Jani Rizk, Bashar Sotin, Christophe Stofan, Ellen R. Sucharski, Tracie L. Tomasko, Martin G. Wall, Stephen D. TI Correlations between Cassini VIMS spectra and RADAR SAR images: Implications for Titan's surface composition and the character of the Huygens probe landing site SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Titan; VIMS; radar; SAR; DISR; dunes; mantles; coatings; substrate; water ice; hydrocarbons; titriles; tholin; aerosols ID OPTICAL-CONSTANTS; MU-M; HAZE; ATMOSPHERE; DESCENT; METHANE; LIQUID; ALBEDO; MAPPER AB Titan's vast equatorial fields of RADAR-dark longitudinal dunes seen in Cassini RADAR synthetic aperture images correlate with one of two dark surface units discriminated as "brown" and "blue" in Visible and Infrared Mapping Spectrometer (VIMS) color composites of short-wavelength infrared spectral cubes (RGB as 2.0, 1.6, 1.3 mu m). In such composites bluer materials exhibit higher reflectance at 1.3 pm and lower at 1.6 and 2.0 pm. The dark brown unit is highly correlated with the RADAR-dark dunes. The dark brown unit shows less evidence of water ice suggesting that the saltating grains of the dunes are largely composed of hydrocarbons and/or nitriles. In general, the bright units also show less evidence of absorption due to water ice and are inferred to consist of deposits of bright fine precipitating tholin aerosol dust. Some set of chemical/mechanical processes may be converting the bright fine-grained aerosol deposits into the dark saltating hydrocarbon and/or nitrile grains. Alternatively the dark dune materials may be derived from a different type of air aerosol photochemical product than are the bright materials. In our model, both the bright aerosol and dark hydrocarbon dune deposits mantle the VIMS dark blue water ice-rich substrate. We postulate that the bright mantles are effectively invisible (transparent) in RADAR synthetic aperture. radar (SAR) images leading to lack of correlation in the RADAR images with optically bright mantling units. RADAR images mostly show only dark dunes and the water ice substrate that varies in roughness, fracturing, and porosity. If the rate of deposition of bright aerosol is 0.001-0.01 mu m/yr, the surface would be coated (to optical instruments) in hundreds-to-thousands of years unless cleansing processes are active. The dark dunes must-be mobile on this very short timescale to prevent the accumulation of bright coatings. Huygens landed in a region of the VIMS bright and dark blue materials and about 30 km south of the nearest occurrence of dunes visible in the RADAR SAR images. Fluvial/pluvial processes, every few centuries or millennia, must be cleansing the dark floors of the incised channels and scouring the dark plains at the Huygens landing site both imaged by Descent Imager/Spectral Radiometer (DISR). (c) 2007 Elsevier Ltd. All rights reserved. C1 US Geol Survey, Flagstaff, AZ 86001 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. Ames Res Ctr, NASA, Moffett Field, CA USA. US Geol Survey, Denver, CO USA. Inst Planetary Explorat, Berlin, Germany. Univ Nantes, F-44035 Nantes, France. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 21218 USA. Univ Hawaii, HIGP, SOEST, Honolulu, HI 96822 USA. Cornell Univ, Ithaca, NY 14853 USA. Brigham Young Univ, Provo, UT 84602 USA. Proxemy Res, Rectortown, VA USA. RP Soderblom, LA (reprint author), US Geol Survey, Flagstaff, AZ 86001 USA. EM lsoderblom@usgs.gov RI Barnes, Jason/B-1284-2009; Lorenz, Ralph/B-8759-2016; Lopes, Rosaly/D-1608-2016 OI Barnes, Jason/0000-0002-7755-3530; Lorenz, Ralph/0000-0001-8528-4644; Lopes, Rosaly/0000-0002-7928-3167 NR 45 TC 93 Z9 94 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 NOV PY 2007 VL 55 IS 13 BP 2025 EP 2036 DI 10.1016/j.pss.2007.04.014 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235AQ UT WOS:000251206300014 ER PT J AU Nielsen, E Fraenz, M Zou, H Wang, JS Gurnett, DA Kirchner, DL Morgan, DD Huff, R Safaeinili, A Plaut, JJ Picardi, G Winningham, JD Frahm, RA Lundin, R AF Nielsen, E. Fraenz, M. Zou, H. Wang, J. S. Gurnett, D. A. Kirchner, D. L. Morgan, D. D. Huff, R. Safaeinili, A. Plaut, J. J. Picardi, G. Winningham, J. D. Frahm, R. A. Lundin, R. TI Local plasma processes and enhanced electron densities in the lower ionosphere in magnetic cusp regions on Mars SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Mars; ionosphere; convection; sounding radar ID RADAR; FIELD; IRREGULARITIES; BACKSCATTER; ATMOSPHERE; WAVES AB Both the MARSIS ionospheric sounder and the charged particle instrument package ASPERA-3 are experiments on board the Mars Express spacecraft. Joint observations have shown that events of intense ionospheric electron density enhancements occur in the lower ionosphere of magnetic cusp regions, and that these enhancements are not associated with precipitation of charged particles above a few hundred electron volts (< 300 eV). To account for the enhancement by particle precipitation, electron fluxes are required with mean energy between 1 and 10 keV. No ionizing radiation, neither energetic particles nor X-rays, could be identified, which could produce the observed density enhancement only in the spatially limited cusp regions. Actually, no increase in ionizing radiation, localized or not, was observed during these events. It is argued that the process causing the increase in density is controlled mainly by convection of ionosphere plasma driven by the interaction between the solar wind and crustal magnetic field lines leading to excitation of two-stream plasma waves in the cusp ionosphere. The result is to heat the plasma, reduce the electron-ion recombination coefficient and thereby increase the equilibrium electron density. (c) 2007 Elsevier Ltd. All rights reserved. C1 [Nielsen, E.; Fraenz, M.; Zou, H.; Wang, J. S.] Max Planck Inst Solar Syst Res, D-37191 Katlenburg Duhm, Germany. [Gurnett, D. A.; Kirchner, D. L.; Morgan, D. D.; Huff, R.; Picardi, G.] Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. [Safaeinili, A.; Plaut, J. J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Picardi, G.] Univ Roma La Sapienza, Infocon Dept, I-00184 Rome, Italy. [Winningham, J. D.; Frahm, R. A.] SW Res Inst, San Antonio, TX 78228 USA. [Lundin, R.] Swedish Inst Space Phys, S-98128 Kiruna, Sweden. RP Nielsen, E (reprint author), Max Planck Inst Solar Syst Res, D-37191 Katlenburg Duhm, Germany. EM nielsen@mps.mpg.de NR 31 TC 26 Z9 27 U1 1 U2 4 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 NOV PY 2007 VL 55 IS 14 BP 2164 EP 2172 DI 10.1016/j.pss.2007.07.003 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 245HL UT WOS:000251925600016 ER PT J AU Sittler, EC Thomsen, M Johnson, RE Hartle, RE Burger, M Chornay, D Shappirio, MD Simpson, D Smith, HT Coates, AJ Rymer, AM McComas, DJ Young, DT Reisenfeld, D Dougherty, M Andre, N AF Sittler, E. C. Thomsen, M. Johnson, R. E. Hartle, R. E. Burger, M. Chornay, D. Shappirio, M. D. Simpson, D. Smith, H. T. Coates, A. J. Rymer, A. M. McComas, D. J. Young, D. T. Reisenfeld, D. Dougherty, M. Andre, N. TI Cassini observations of Saturn's inner plasmasphere: Saturn orbit insertion results (vol 54, pg 1197, 2006) SO PLANETARY AND SPACE SCIENCE LA English DT Correction C1 [Sittler, E. C.; Hartle, R. E.; Burger, M.; Chornay, D.; Shappirio, M. D.; Simpson, D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Thomsen, M.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Johnson, R. E.; Smith, H. T.] Univ Virginia, Charlottesville, VA USA. [Rymer, A. M.] Johns Hopkins Appl Phys Lab, Baltimore, MD 21218 USA. [McComas, D. J.; Young, D. T.] SW Res Inst, San Antonio, TX USA. [Reisenfeld, D.] Univ Montana, Missoula, MT 59812 USA. [Dougherty, M.] Univ London Imperial Coll Sci Technol & Med, London, England. RP Sittler, EC (reprint author), NASA, Goddard Space Flight Ctr, Code 612-2,8800 Greenbelt Rd, Greenbelt, MD 20771 USA. EM edward.c.sittler@nasa.gov RI Coates, Andrew/C-2396-2008; Reisenfeld, Daniel/F-7614-2015; Smith, Howard/H-4662-2016 OI Coates, Andrew/0000-0002-6185-3125; Smith, Howard/0000-0003-3537-3360 FU Science and Technology Facilities Council [PP/D00084X/1] NR 1 TC 13 Z9 13 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 NOV PY 2007 VL 55 IS 14 BP 2218 EP 2220 DI 10.1016/j.pss.2006.11.022 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 245HL UT WOS:000251925600020 ER PT J AU Negrao, A Coustenis, A Lellouch, E Maillard, JP Rannou, P Schmitt, B Mckay, CP Boudon, V AF Negrao, A. Coustenis, A. Lellouch, E. Maillard, J. -P. Rannou, P. Schmitt, B. McKay, C. P. Boudon, V. TI Titan's surface albedo variations over a Titan season from near-infrared CFHT/FTS spectra (vol 54, pg 1225, 2006) SO PLANETARY AND SPACE SCIENCE LA English DT Correction C1 Observ Paris, Sect Meudon, LESIA, F-92195 Meudon, France. [Negrao, A.] Observ Astron Lisboa, P-1349018 Lisbon, Portugal. [Negrao, A.; Rannou, P.] Univ Versailles St Quentin, IPSL, Serv Aeron, Versailles, France. [Maillard, J. -P.] Inst Astrophys, F-75014 Paris, France. [Schmitt, B.] Lab Planetol, Grenoble, France. [McKay, C. P.] NASA, AMES, Moffett Field, CA 94035 USA. [Boudon, V.] Univ Bourgogne, Phys Lab, Dijon, France. RP Negrao, A (reprint author), Observ Paris, Sect Meudon, LESIA, 5 Pl Jules Janssen, F-92195 Meudon, France. EM alberto-negrao@obspm.fr RI BOUDON, Vincent/A-4504-2010; RANNOU, Pascal/I-9059-2012; OI Negrao, Alberto/0000-0001-6042-1294 NR 1 TC 0 Z9 0 U1 1 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 NOV PY 2007 VL 55 IS 14 BP 2221 EP 2221 DI 10.1016/j.pss.2007.02.006 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 245HL UT WOS:000251925600021 ER PT J AU Shambayati, S AF Shambayati, Shervin TI Ka-band telemetry operations concept: A statistical approach SO PROCEEDINGS OF THE IEEE LA English DT Article DE deep-space communications; Ka-band; operations concept; telecommunications link design ID SLANT PATH; PROPAGATION; ACTS AB Future NASA missions such as the Lunar Reconnaissance Orbiter, Kepler, James Webb Space Telescope, and Space Interferometry mission will use Ka-band frequencies (26.5- and 32-GHz bands) for their primary science downlink instead of X-band frequencies (8.42-GHz band) due to scarcity of spectrum at X-band. At Ka-band frequencies, adverse weather events degrade the telemetry link performance to a greater degree than they do at X-band. The uncertainty about the weather losses at Ka-band is much greater than the uncertainty about all other losses on the link combined. Therefore, the traditional link design approach used for X-band links has to be modified. in this paper, we propose a link design approach where the atmospheric noise temperature statistics along with the ground antenna characteristics are used to optimize the average data return on the link. We introduce the mathematical foundations of this approach and present optimal link design strategies for using Ka-band both at 26.5- and at 32-GHz bands for future NASA missions. C1 Jet Propuls Lab, Pasadena, CA 91109 USA. RP Shambayati, S (reprint author), Jet Propuls Lab, Pasadena, CA 91109 USA. EM shervin.shambayati@jpl.nasa.gov NR 10 TC 11 Z9 11 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD NOV PY 2007 VL 95 IS 11 BP 2171 EP 2179 DI 10.1109/JPROC.2007.905136 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 239EZ UT WOS:000251502900008 ER PT J AU Bar-Sever, YE Jacobs, CS Keihm, S Lanyl, GE Naudet, CJ Rosenberger, HW Runge, TF Tanner, AB Vigue-Rodi, Y AF Bar-Sever, Yoaz E. Jacobs, Christopher S. Keihm, Stephen Lanyl, Gabor E. Naudet, Charles J. Rosenberger, Hans W. Runge, Thomas F. Tanner, Alan B. Vigue-Rodi, Yvonne TI Atmospheric media calibration for the deep space network SO PROCEEDINGS OF THE IEEE LA English DT Article DE calibrations; Deep space Network (DSN); GIPSY; GPS; interplanetary; navigation; spacecraft; troposphere; very long baseline interferometry (VLBI); water vapor radiometer (WVR) ID BASE-LINE INTERFEROMETRY; PATH DELAY; WAVELENGTH; MODEL; GHZ AB Two tropospheric calibration systems have been developed at the Jet Propulsion Laboratory (JPL) using different technologies to achieve different levels of accuracy, timeliness, and range of coverage for support of interplanetary NASA flight operations. The first part of this paper describes an automated GPS-based system that calibrates the zenith tropospheric delays. These calibrations cover all times and can be mapped to any line of sight using elevation mapping functions. Thus they can serve any spacecraft with no prior scheduling or special equipment deployment. Centimeter-level accuracy is provided with 1-h latency and better than 1-cm accuracy after 12 h, limited primarily by rapid fluctuations of the atmospheric water vapor. The second part describes a more accurate line-of-sight media calibration system that is primarily based on a narrow beam, gain-stabilized advanced water vapor radiometer developed at JPL. We discuss experiments that show that the wet troposphere in short baseline interferometry can be calibrated such that the Allan standard deviation of phase,residuals, a unitless measure of the average fractional frequency deviation, is better than 2 x 10(-15), on time scales of 2000 to Approximately 10 000 s. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Bar-Sever, YE (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. EM Yoaz.E.BarSever@jp1.nasa.gov; Chris.Jacobs@jpl.nasa.gov; Steve.Keihm@jpl.nasa-gov; Gabor.E.Lanyi@jpl.nasa.gov; Charles.J.Naudet@jpl.nasa.gov; Gabor.E.Lanyi@jpi.nasa.gov; Thomas.F.Runge@jpl.nasa.gov; Alan.Tanner@jpl.nasa.gov; Yvonne.Vigue-Rodi@jpl.nasa.gov NR 39 TC 10 Z9 11 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD NOV PY 2007 VL 95 IS 11 BP 2180 EP 2192 DI 10.1109/JPROC.2007.905181 PG 13 WC Engineering, Electrical & Electronic SC Engineering GA 239EZ UT WOS:000251502900009 ER PT J AU Lanyi, G Bagri, DS Border, JS AF Lanyi, Gabor Bagri, Durgadas S. Border, James S. TI Angular position determination of spacecraft by radio interferometry SO PROCEEDINGS OF THE IEEE LA English DT Article DE angular; Deep Space Network (DSN); differential; differential one-way ranging (DOR); interferometry; navigation; position; spacecraft; tracking; Very Long Baseline Array (VLBA); very long baseline interferometry (VLBI) ID DELAY AB This paper describes a variety of interferometric techniques that may be used for measuring the angular location of a spacecraft with respect to natural celestial radio sources or another spacecraft. The differential propagation time-delay techniques largely cancel the common error sources and normally achieve low angular coordinate errors. Currently, the accuracy of the techniques are in the 1-2 nrad range for observations with a duration of one hour and 3-6 degrees of mean angular separation between the spacecraft and the reference sources at X-band frequencies. There are various possible ways to implement the differential angular measurements depending upon the determination of the phase cycle ambiguities associated with the differential propagation time delays of remote sources. There are methods that utilize a sufficiently large range of observing frequencies and others that rely upon the spatial arrangement of the receiving system and the rotation of the terrestrial platform. We summarize the methodologies and the advantages and disadvantages of the various techniques. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Lanyi, G (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. EM gelanyi@jpl.nasa.gov; dbagri@jpl.nasa.gov; jsborder@jpl.nasa.gov NR 26 TC 28 Z9 34 U1 2 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD NOV PY 2007 VL 95 IS 11 BP 2193 EP 2201 DI 10.1109/JPROC.2007.905183 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 239EZ UT WOS:000251502900010 ER PT J AU Berner, JB Bryant, SH Kinman, PW AF Berner, Jeff B. Bryant, Scott H. Kinman, Peter W. TI Range measurement as practiced in the Deep Space Network SO PROCEEDINGS OF THE IEEE LA English DT Article DE Deep Space Network; pseudonoise ranging; range measurement; sequential ranging ID SEQUENCES; MISSIONS AB Range measurements are used to improve the trajectory models of spacecraft tracked by the Deep Space Network. The unique challenge of deep-space ranging is that the two-way delay is long, typically many minutes, and the signal-to-noise ratio is small. Accurate measurements are made under these circumstances by means of long correlations that incorporate Doppler rate-aiding. This processing is done with commercial digital signal processors, providing a flexibility in signal design that clan accommodate both the traditional sequential ranging signal and pseudonoise range codes. Accurate range determination requires the calibration of the delay within the tracking station. Measurements with a standard deviation of 1 in have been made. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. Calif State Univ Fresno, Fresno, CA 93740 USA. RP Berner, JB (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. EM jeff.b.berner@jpl.nasa.gov; scott.h.bryant@jpl.nasa.gov; pkinman@csufresno.edu NR 18 TC 7 Z9 10 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD NOV PY 2007 VL 95 IS 11 BP 2202 EP 2214 DI 10.1109/JPROC.2007.905128 PG 13 WC Engineering, Electrical & Electronic SC Engineering GA 239EZ UT WOS:000251502900011 ER PT J AU Prestage, JD Weaver, GL AF Prestage, John D. Weaver, Gregory L. TI Atomic clocks and oscillators for deep-space navigation and radio science SO PROCEEDINGS OF THE IEEE LA English DT Article DE Allan deviation; linear ion trap; radiometric; redshift; space-borne atomic clock; space clock; ultrastable oscillator ID MARS GLOBAL SURVEYOR; GALILEO PROBE; JUPITER; WINDS AB This paper describes new oscillator and atomic clock technologies that, when combined, create a master oscillator for use in cleep-space navigation and science measurements. This atomic clock promises to execute spacecraft navigation using a one-way downlink only method, saving many millions of dollars per year. We will describe the complementary technology developments by the Jet Propulsion Laboratory toward a space-ready mercury atomic-ion clock and by the Applied Physics Laboratory, Johns Hopkins University, in reducing the size, mass, and operating power of its quartz, ultrastable oscillator. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Prestage, JD (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. EM john.d.prestage@jpl.nasa.gov NR 40 TC 33 Z9 36 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD NOV PY 2007 VL 95 IS 11 BP 2235 EP 2247 DI 10.1109/JPROC.2007.905130 PG 13 WC Engineering, Electrical & Electronic SC Engineering GA 239EZ UT WOS:000251502900014 ER PT J AU Revankar, ST Olenik, H Jo, D Motil, B AF Revankar, S. T. Olenik, H. Jo, D. Motil, B. TI Local instrumentation for the investigation of multi-phase parameters in a packed bed SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING LA English DT Article DE packed bed; multi-phase flow; film-thickness probe; impedance void meter; conductivity probe ID LIQUID-FILM THICKNESS; 2-PHASE FLOW; ELECTRORESISTIVITY PROBE; BUBBLE PARAMETERS; RESISTIVITY PROBE; WIRE PROBES; DISPERSIONS; FRACTION AB Local two-point conductivity probe and film-thickness probes were developed for measurement of two-phase flow parameters in a packed bed containing spherical packing. The probes were calibrated and installed in a packed bed with minimal flow disturbance. A flush and two parallel wire film-thickness probes were used to measure the liquid film thickness on the packing. The conductivity probe and impedance meter were used to measure local and bed wise void fraction, respectively, for trickle, wavy, transitional, pulsing, and bubbly flow. C1 Purdue Univ, Sch Nucl Engn, W Lafayette, IN 47906 USA. NASA Glenn Res Ctr, Fluids Phys & Transport Branch, Cleveland, OH USA. RP Revankar, ST (reprint author), Purdue Univ, Sch Nucl Engn, 400 Cent Dr, W Lafayette, IN 47906 USA. EM shripad@ecn.purdue.edu NR 31 TC 4 Z9 4 U1 1 U2 3 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI WESTMINISTER PA 1 BIRDCAGE WALK, WESTMINISTER SW1H 9JJ, ENGLAND SN 0954-4089 J9 P I MECH ENG E-J PRO JI Proc. Inst. Mech. Eng. Part E-J. Process Mech. Eng. PD NOV PY 2007 VL 221 IS E4 BP 187 EP 199 DI 10.1243/09544089JPME142 PG 13 WC Engineering, Mechanical SC Engineering GA 237DS UT WOS:000251354000003 ER PT J AU High, FW Rhodes, J Massey, R Ellis, R AF High, F. William Rhodes, Jason Massey, Richard Ellis, Richard TI Pixelation effects in weak lensing SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID HUBBLE-SPACE-TELESCOPE; LARGE-SCALE STRUCTURE; COSMIC SHEAR; POLAR SHAPELETS; IMAGES; PHOTOMETRY AB Weak gravitational lensing can be used to investigate both dark matter and dark energy but requires accurate measurements of the shapes of faint, distant galaxies. Such measurements are hindered by the finite resolution and pixel scale of digital cameras. We investigate the optimum choice of pixel scale for a space-based mission, using the engineering model and survey strategy of the proposed Supernova Acceleration Probe as a baseline. We do this by simulating realistic astronomical images containing a known input shear signal and then attempting to recover the signal using the Rhodes, Refregier, & Groth algorithm. We find that the quality of shear measurement is always improved by smaller pixels. However, in practice, telescopes are usually limited to a finite number of pixels and operational life span, so the total area of a survey increases with pixel size. We therefore fix the survey lifetime and the number of pixels in the focal plane while varying the pixel scale, thereby effectively varying the survey size. In a pure trade-off for image resolution versus survey area, we find that measurements of the matter power spectrum would have minimum statistical error with a pixel scale of 0.09 '' for a 0.14 '' FWHM point-spread function (PSF). The pixel scale could be increased to similar to 0.16 '' if images dithered by exactly half-pixel offsets were always available. Some of our results do depend on our adopted shape measurement method and should be regarded as an upper limit: future pipelines may require smaller pixels to overcome systematic floors not yet accessible, and, in certain circumstances, measuring the shape of the PSF might be more difficult than those of galaxies. However, the relative trends in our analysis are robust, especially those of the surface density of resolved galaxies. Our approach thus provides a snapshot of potential in available technology, and a practical counterpart to analytic studies of pixelation, which necessarily assume an idealized shape measurement method. C1 [High, F. William] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. [High, F. William; Rhodes, Jason; Massey, Richard; Ellis, Richard] CALTECH, Pasadena, CA 91125 USA. [Rhodes, Jason] CALTECH, Jet Propuls Lab, Pasadena, CA USA. RP High, FW (reprint author), Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. NR 39 TC 6 Z9 6 U1 0 U2 1 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 NOV PY 2007 VL 119 IS 861 BP 1295 EP 1307 DI 10.1086/523112 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 242PB UT WOS:000251736600007 ER PT J AU McCallon, HL Fowler, JW Laher, RR Masci, FJ Moshir, M AF McCallon, Howard L. Fowler, John W. Laher, Russ R. Masci, Frank J. Moshir, Mehrdad TI Refinement of the Spitzer Space Telescope pointing history based on image registration corrections from multiple data channels SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article AB Position reconstruction for images acquired by the Infrared Array Camera (IRAC), one of the science instruments onboard the Spitzer Space Telescope, is a multistep procedure that is part of the routine processing done at the Spitzer Science Center (SSC). The IRAC instrument simultaneously images two different sky footprints, each with two independent infrared passbands (channels). The accuracy of the initial Spitzer pointing reconstruction is typically slightly better than 1 ''. The well-known technique of position matching imaged point sources to even more accurate star catalogs to refine the pointing further is implemented for SSC processing of IRAC data as well. Beyond that, the optimal processing of redundant pointing information from multiple instrument channels to yield an even better solution is also performed at the SSC. Our multichannel data processing approach is particularly beneficial when the star-catalog matches are sparse in one channel but copious in others. A thorough review of the algorithm as implemented for the Spitzer mission reveals that the mathematical formalism can be fairly easily generalized for application to other astronomy missions. The computation of pointing uncertainties, the interpolation of pointing corrections and their uncertainties between measurements, and the estimation of random-walk deviations from linearity are special areas of importance when implementing the method. After performing the operations described in this paper on the initial Spitzer pointing, the uncertainty in the observatory pointing history file is reduced 10-15 fold. C1 [McCallon, Howard L.; Fowler, John W.; Masci, Frank J.] CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. [Laher, Russ R.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. [Moshir, Mehrdad] Jet Propuls Lab, Pasadena, CA 91109 USA. RP McCallon, HL (reprint author), CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. EM laher@ipac.caltech.edu NR 5 TC 1 Z9 1 U1 0 U2 1 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 NOV PY 2007 VL 119 IS 861 BP 1308 EP 1324 DI 10.1086/523599 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 242PB UT WOS:000251736600008 ER PT J AU Deline, C Gilchrist, BE Dobson, C Jones, JE Chavers, DG AF Deline, C. Gilchrist, B. E. Dobson, C. Jones, J. E. Chavers, D. G. TI High accuracy plasma density measurement using hybrid Langmuir probe and microwave interferometer method SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ELECTRON-DENSITY; TRIPLE PROBE; INSTRUMENT; PROPULSION; SYSTEM AB High spatial resolution plasma density measurements have been taken as part of an investigation into magnetic nozzle physics at the NASA/MSFC Propulsion Research Center. These measurements utilized a Langmuir triple probe scanned across the measurement chord of either of two stationary rf interferometers. By normalizing the scanned profile to the microwave interferometer line-integrated density measurement for each electrostatic probe measurement, the effect of shot-to-shot variation of the line-integrated density can be removed. In addition, by summing the voltage readings at each radial position in a transverse scan, the line density can be reconstituted, allowing the absolute density to be determined, assuming that the shape of the profile is constant from shot to shot. The spatial and temporal resolutions of this measurement technique depend on the resolutions of the scanned electrostatic probe and the interferometer. The measurement accuracy is 9%-15%, which is on the order of the accuracy of the rf interferometer. The measurement technique was compared directly with both scanning rf interferometer and standard Langmuir probe theory. The hybrid technique compares favorably with the scanning rf interferometer, and appears more accurate than probe theory alone. Additionally, our measurement technique is generally applicable even for nonaxisymmetric plasmas. (C) 2007 American Institute of Physics. C1 Univ Michigan, Radiat Lab, Ann Arbor, MI 48109 USA. NASA, George C Marshall Space Flight Ctr, Prop Res Ctr, Huntsville, AL 35812 USA. RP Deline, C (reprint author), Univ Michigan, Radiat Lab, Ann Arbor, MI 48109 USA. RI Deline, Christopher/K-5998-2013 OI Deline, Christopher/0000-0002-9867-8930 NR 20 TC 8 Z9 8 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 2007 VL 78 IS 11 AR 113504 DI 10.1063/1.2813885 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 236TI UT WOS:000251325900016 PM 18052471 ER PT J AU Earle, GD Klenzing, JH Roddy, PA Macaulay, WA Perdue, MD Patrick, EL AF Earle, G. D. Klenzing, J. H. Roddy, P. A. Macaulay, W. A. Perdue, M. D. Patrick, E. L. TI A new satellite-borne neutral wind instrument for thermospheric diagnostics SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID IRREGULARITIES AB The bulk motion of the neutral gas at altitudes between about 200 and 600 km is an important factor in predicting the onset of plasma instabilities that are known to distort and/or disrupt high frequency radio communications. These neutral winds have historically been quite difficult to measure, especially from a moving spacecraft. A new space science instrument called the ram wind sensor has been developed to measure the component of the neutral gas velocity that lies along the orbit track of a satellite in low Earth orbit. Laboratory tests of an engineering model of the instrument have been carried out using a supersonic neutral argon beam, in order to validate the measurement concept. The results show that the technique is viable for measurements of neutral flow velocities in future satellite missions. C1 Univ Texas Dallas, William B Hanson Ctr Space Sci, Richardson, TX 75083 USA. Goddard Space Flight Ctr, Honeywell Atmosp Expt Lab, Greenbelt, MD 20771 USA. RP Earle, GD (reprint author), Univ Texas Dallas, William B Hanson Ctr Space Sci, 800 W Campbell Rd, Richardson, TX 75083 USA. EM earle@utdallas.edu RI Klenzing, Jeff/E-2406-2011 OI Klenzing, Jeff/0000-0001-8321-6074 NR 11 TC 5 Z9 5 U1 1 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 2007 VL 78 IS 11 AR 114501 DI 10.1063/1.2813343 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 236TI UT WOS:000251325900038 PM 18052493 ER PT J AU Yee, HC Sjorgreen, B AF Yee, H. C. Sjorgreen, B. TI Simulation of Richtmyer-Meshkov instability by sixth-order filter methods SO SHOCK WAVES LA English DT Article; Proceedings Paper CT 17th International Shock Interaction Symposium (ISIS 17) CY SEP 04-08, 2006 CL Rome, ITALY ID NAVIER-STOKES EQUATIONS; HIGH-ORDER METHODS; NUMERICAL DISSIPATION; DIFFERENCE-METHODS; SCHEMES; FLOWS; INTERFACE; EULER AB Simulation of a 2-D Richtmyer-Meshkov instability (RMI), including inviscid, viscous and magnetic field effects was conducted comparing recently developed sixth-order filter schemes with various standard shock-capturing methods. The suppression of the inviscid gas dynamics RMI in the presence of a magnetic field was investigated by Samtaney and Wheatley et al. Numerical results illustrated here exhibit behavior similar to the work of Samtaney. Due to the different amounts and different types of numerical dissipation contained in each scheme, the structures and the growth of eddies for the chaotic-like inviscid gas dynamics RMI case are highly grid size and scheme dependent, even with many levels of refinement. The failure of grid refinement for all studied numerical methods extends to the viscous gas dynamics case for high Reynolds number. For lower Reynolds number, grid convergence has been achieved by all studied methods. To achieve similar resolution, standard shock-capturing methods require more grid points than filter schemes and yet the CPU times using the same grid for all studied methods are comparable. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. KTH, NADA, Stockholm, Sweden. RP Yee, HC (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM yee@nas.nasa.gov; bjorns@nada.kth.se NR 36 TC 5 Z9 6 U1 0 U2 6 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0938-1287 J9 SHOCK WAVES JI Shock Waves PD NOV PY 2007 VL 17 IS 3 BP 185 EP 193 DI 10.1007/s00193-007-0104-z PG 9 WC Mechanics SC Mechanics GA 233KK UT WOS:000251089600003 ER PT J AU Mitchell, LA Gao, J Wal, RV Gigliotti, A Burchiel, SW McDonald, JD AF Mitchell, Leah A. Gao, Jun Wal, Randy Vander Gigliotti, Andrew Burchiel, Scott W. McDonald, Jacob D. TI Pulmonary and systemic immune response to inhaled multiwalled carbon nanotubes SO TOXICOLOGICAL SCIENCES LA English DT Article DE carbon nanotubes; inhalation; pulmonary pathology; immunosuppression ID DIESEL-ENGINE EMISSIONS; JP-8 JET FUEL; BODY INHALATION EXPOSURE; OXIDATIVE STRESS; HEALTH RISKS; IN-VIVO; TOXICITY; EXHAUST; IMMUNOTOXICITY; PARTICULATE AB Inhalation of multiwalled carbon nanotubes (MWCNTs) at particle concentrations ranging from 0.3 to 5 mg/m(3) did not result in significant lung inflammation or tissue damage, but caused systemic immune function alterations. C57BL/6 adult (10- to 12-week) male mice were exposed by whole-body inhalation to control air or 0.3, 1, or 5 mg/m(3) respirable aggregates of MWCNTs for 7 or 14 days (6 h/day). Histopathology of lungs from exposed animals showed alveolar macrophages containing black particles; however, there was no inflammation or tissue damage observed. Bronchial alveolar lavage fluid also demonstrated particle-laden macrophages; however, white blood cell counts were not increased compared to controls. MWCNT exposures to 0.3 mg/m(3) and higher particle concentrations caused nonmonotonic systemic immunosuppression after 14 days but not after 7 days. Immunosuppression was characterized by reduced T-cell-dependent antibody response to sheep erythrocytes as well as T-cell proliferative ability in presence of mitogen, Concanavalin A. Assessment of nonspecific natural killer (NK) cell activity showed that animals exposed to 1 mg/m(3) had decreased NK cell function. Gene expression analysis of selected cytokines and an indicator of oxidative stress were assessed in lung tissue and spleen. No changes in gene expression were observed in lung; however, interleukin-10 (IL-10) and NAD(P)H oxidoreductase 1 mRNA levels were increased in spleen. C1 Lovelace Resp Res Inst, Albuquerque, NM 87108 USA. Univ New Mexico, Coll Pharm, Albuquerque, NM 87131 USA. NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. RP McDonald, JD (reprint author), Lovelace Resp Res Inst, 2425 Ridgecrest Dr SE, Albuquerque, NM 87108 USA. EM jmcdonal@lrri.org FU NIEHS NIH HHS [5 S11 ES013339-03, P30 ES012072] NR 42 TC 234 Z9 243 U1 2 U2 27 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1096-6080 J9 TOXICOL SCI JI Toxicol. Sci. PD NOV PY 2007 VL 100 IS 1 BP 203 EP 214 DI 10.1093/toxsci/kfm196 PG 12 WC Toxicology SC Toxicology GA 227VT UT WOS:000250686600023 PM 17660506 ER PT J AU Geiger, HJ Wang, I Malecha, P Hebert, K Smoker, WW Gharrett, AJ AF Geiger, Harold J. Wang, Ivan Malecha, Pat Hebert, Kyle Smoker, William W. Gharrett, Anthony J. TI What causes variability in pink salmon family size? SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID ONCORHYNCHUS-GORBUSCHA; MARINE SURVIVAL; COHO SALMON; PACIFIC; ALASKA; LIFE; POPULATIONS; VARIANCE; NUMBERS; RATIO AB To study family-specific variation in the survival of pink salmon Oncorhynchus gorbuscha, we partitioned family size into four life history divisions: (1) maternal fecundity, (2) deposition of fertilized eggs and egg loss from the redd, (3) freshwater survival (and male potency), and (4) marine survival. We directly measured the variability in fecundity and then measured the family-specific variability of freshwater survival in several Alaskan hatchery populations. Next, we measured freshwater survival in spatially clustered groups of wild pink salmon (not identified to a specific dam or sire) in Prince William Sound, Alaska. Drawing on estimates of the family-specific variation of marine survival in pink salmon from previous studies, we concluded that family-specific egg deposition processes and family-specific variability in the marine environment were the primary sources of the overall variability in pink salmon family size, at least in the populations studied. We hypothesize that the freshwater environment generally induces lower variability in family size than does the marine environment. If this is so, it appears that pink salmon populations are more finely adapted to the freshwater environment, presumably because this environment is more constant. Finally, we speculate that the marine environment is too unpredictable to permit the same level of adaptation of many traits closely linked to marine survival. C1 [Geiger, Harold J.] Alaska Dept Fish & Game, Juneau, AK 99811 USA. [Geiger, Harold J.; Wang, Ivan; Malecha, Pat; Hebert, Kyle; Smoker, William W.; Gharrett, Anthony J.] Univ Alaska Fairbanks, Sch Fisheries & Ocean Sci, Juneau, AK 99801 USA. [Malecha, Pat] Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. RP Geiger, HJ (reprint author), St Hubert Res Grp, 7655 N Douglas Highway, Juneau, AK 99801 USA. EM geiger@alaska.com NR 40 TC 3 Z9 3 U1 2 U2 5 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD NOV PY 2007 VL 136 IS 6 BP 1688 EP 1698 DI 10.1577/T07-050.1 PG 11 WC Fisheries SC Fisheries GA 251KH UT WOS:000252371400020 ER PT J AU Sullivan, DG Fulton, JP Shaw, JN Bland, G AF Sullivan, D. G. Fulton, J. P. Shaw, J. N. Bland, G. TI Evaluating the sensitivity of an unmanned thermal infrared aerial system to detect water stress in a cotton canopy SO TRANSACTIONS OF THE ASABE LA English DT Article DE cotton; crop residue management; irrigation; thermal infrared; unmanned airvehicle ID TEMPERATURE; WHEAT; INDICATOR AB Airborne thermal infrared (TIR) imagery is a promising and innovative tool for assessing canopy response to a range of stressors. However, the expense associated with acquiring imagery for agricultural management is often cost prohibitive. The objective of this study was to evaluate a less expensive system, an unmanned airvehicle (UAV) equipped with a TIR sensor, for detecting cotton (Gossypium hirsutum L.)response to irrigation and crop residue management. The experimental site was located on a 6.1 ha field in the Tennessee Valley Research and Extension Center located in Belle Mina, Alabama, where landscapes are gently rolling and soils are highly weathered Rhodic Paleudults. Treatments consisted of irrigation (dryland or subsurface drip irrigation) and crop residue cover (no cover or winter wheat (Triticum aestivum L.)). TIR (7 to 14 mu m) imagery was acquired on 18 July 2006 at an altitude of 90 m and spatial resolution of 0.5 m. Coincident with image acquisition, ground truth data consisting of soil water content (0-25 cm), stomatal conductance, and canopy cover were measured within a 1 m radius of each sample location. All sample locations were georeferenced using a real-time kinematic (RTK) GPS survey unit. Analysis of sample locations acquired in multiple flight lines was used to assess the stability and repeatability of the UAV system during an acquisition. Compared to field measurements of stomatal conductance with CVs ranging from 2% to 75%, variability in TIR emittance (CV < 40%) was within the observed tolerance of ground truth measurements of stomatal conductance. Significant differences in canopy cover and stomatal conductance across irrigation treatments allowed testing of the sensitivity of the UAV system. A negative correlation was observed between TIR emittance and stomatal conductance (r = -0.48) and canopy closure (r = -0.44), indicating increasing canopy stress as stomatal conductance and canopy closure decreased. TIR emittance exhibited greater sensitivity to canopy response compared to ground truth measurements, differentiating between irrigation and crop residue cover treatments. TIR imagery acquired with a low-altitude UAV can be used as a tool to manage within-season canopy stress. C1 [Sullivan, D. G.] USDA ARS, SE Watershed Res Lab, Tifton, GA 31793 USA. [Fulton, J. P.] Auburn Univ, Dept Biosyst Engn, Auburn, AL 36849 USA. [Shaw, J. N.] Auburn Univ, Dept Agron & Soils, Auburn, AL USA. [Bland, G.] NASA, Goddard Space Flight Ctr, WFF, Wallops Isl, VA 23337 USA. RP Sullivan, DG (reprint author), POB 748, Tifton, GA 31794 USA. EM dgs@tifton.usda.gov NR 24 TC 16 Z9 17 U1 2 U2 21 PU AMER SOC AGRICULTURAL & BIOLOGICAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 USA SN 0001-2351 J9 T ASABE JI Trans. ASABE PD NOV-DEC PY 2007 VL 50 IS 6 BP 1955 EP 1962 PG 8 WC Agricultural Engineering SC Agriculture GA 255IZ UT WOS:000252653000005 ER PT J AU Mukherjee, A Hansen, M AF Mukherjee, Avijit Hansen, Mark TI A dynamic Stochastic model for the single airport ground holding problem SO TRANSPORTATION SCIENCE LA English DT Article DE air traffic flow management; ground delay programs; collaborative decision making; stochastic optimization ID AIR-TRAFFIC-CONTROL; COLLABORATIVE DECISION-MAKING; PROGRAM AB In this paper, we present a dynamic stochastic integer programming (IP) model for the single airport ground holding problem, in which ground delays assigned to flights can be revised during different decision stages, based on weather forecasts. The performance gain from our model is particularly significant in the following cases: (1) under stringent ground holding policy, (2) when an early ground delay program (GDP) cancellation is likely, and (3) for airports where the ratio between adverse and fair weather capacities is lower. The choice of ground delay cost component in the objective function strongly affects the allocation policy. When it is linear, the optimal solution involves releasing the long-haul flights at or near their scheduled departure times and using the short-haul flights to absorb delays if low-capacity scenarios eventuate. This policy resembles the current practice of exempting long-distance flights during ground delay programs. For certain convex ground delay cost functions, the spread of ground delay is more or less uniform across all categories of flights, which makes the overall delay assignment more equitable. Finally, we also present a methodology that could enable intra-airline flight substitutions by airlines after our model has been executed and scenario-specific slots have been assigned to all flights, and hence to the airlines that operate them. This makes our model applicable under the collaborative decision making (CDM) paradigm by allowing airlines to perform cancellations and substitutions and hence reoptimize their internal delay cost functions. C1 Univ Calif Santa Cruz, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Berkeley, Inst Transport Studies, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. RP Mukherjee, A (reprint author), Univ Calif Santa Cruz, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM avijit@ucsc.edu; mhansen@ce.berkeley.edu NR 19 TC 33 Z9 38 U1 4 U2 21 PU INFORMS PI HANOVER PA 7240 PARKWAY DR, STE 310, HANOVER, MD 21076-1344 USA SN 0041-1655 J9 TRANSPORT SCI JI Transp. Sci. PD NOV PY 2007 VL 41 IS 4 BP 444 EP 456 DI 10.1287/trsc.1070.0210 PG 13 WC Operations Research & Management Science; Transportation; Transportation Science & Technology SC Operations Research & Management Science; Transportation GA 234QL UT WOS:000251178700002 ER PT J AU Heinse, R Jones, SB Steinberg, SL Tuller, M Or, D AF Heinse, Robert Jones, Scott B. Steinberg, Susan L. Tuller, Markus Or, Dani TI Measurements and Modeling of variable gravity effects on water distribution and flow in unsaturated porous media SO VADOSE ZONE JOURNAL LA English DT Article ID HYDRAULIC CONDUCTIVITY; GROWING PLANTS; MICROGRAVITY; FLIGHT; SPACE; WHEAT; SOILS; TUBE; GAS AB Liquid behavior under reduced gravity conditions is of considerable interest for various components of life-support systems required for manned space missions. High costs and limited opportunities for spaceflight experiments hinder advances in reliable design and operation of elements involving fluids in unsaturated porous media such as plant growth facilities. We used parabolic flight experiments to characterize hydraulic properties under variable gravity conditions deduced from variations in matric potential over a range of water contents. We designed and tested novel measurement cells that allowed dynamic control of water content. Embedded time domain reflectometry probes and fast-responding tensiometers measured changes in water content and matric potential. For near-saturated conditions, we observed rapid establishment of equilibrium matric potentials during the recurring 20-s periods of microgravity. As media water content decreased, the concurrent decrease in hydraulic diffusivity resulted in limited attainment of equilibrium distributions of water content and matric potential in microgravity, and water content heterogeneity within the sample was influenced by the preceding hypergravity phase. For steady fluxes through saturated columns, we observed linear and constant hydraulic gradients during variable gravity, yielding saturated hydraulic conductivities similar to values measured under terrestrial gravity. Our results suggest that water distribution and retention behavior are sensitive to varied gravitational forces, whereas saturated hydraulic conductivity appears to be unaffected. Comparisons between measurements and simulations based on the Richards equation were in reasonable agreement, suggesting that fundamental laws of fluid flow and distribution for macroscopic transport derived on Earth are also applicable in microgravity. C1 [Heinse, Robert; Jones, Scott B.] Utah State Univ, Dept Plants Soils & Climate, Logan, UT 84322 USA. [Steinberg, Susan L.] Univ Space Res Assoc, NASA JSC, Houston, TX 77058 USA. [Tuller, Markus] Univ Arizona, Dept Soil Water & Environm Sci, Tucson, AZ 85721 USA. [Heinse, Robert] Ecole Polytech Fed Lausanne, Lab Soil & Environm Phys, Lausanne, Switzerland. RP Heinse, R (reprint author), Utah State Univ, Dept Plants Soils & Climate, Logan, UT 84322 USA. EM heinse@cc.usu.edu RI Jones, Scott/A-9745-2010; Heinse, Robert/E-4596-2010; Tuller, Markus/H-1822-2012; Or, Dani/D-8768-2012 OI Jones, Scott/0000-0002-3804-8785; Tuller, Markus/0000-0003-3659-2768; Or, Dani/0000-0002-3236-2933 NR 40 TC 10 Z9 11 U1 2 U2 22 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 1539-1663 J9 VADOSE ZONE J JI Vadose Zone J. PD NOV PY 2007 VL 6 IS 4 BP 713 EP 724 DI 10.2136/vzj2006.0105 PG 12 WC Environmental Sciences; Soil Science; Water Resources SC Environmental Sciences & Ecology; Agriculture; Water Resources GA 254OO UT WOS:000252596100004 ER PT J AU Pint, C Bozzolo, G Garces, JE AF Pint, Cary Bozzolo, Guillermo Garces, Jorge E. TI Atomistic simulation of Fe deposition and alloy formation on Pt substrates SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 13th International Conference on Solid Films and Surfaces (ICSFS 13) CY NOV 06-10, 2006 CL San Carlos de Bariloche, ARGENTINA SP Comis Nacl Energia Atom, ANPCyT, CONICET, CLAF DE surface segregation; semi-empirical methods; computer simulations ID ULTRATHIN FE; ALPHA,BETA-UNSATURATED ALDEHYDES; FILMS; GROWTH; FE/CU(100); MAGNETISM; SURFACES; METAL AB Fe-Pt alloys are of significant importance toward future applications of high-density magnetic recording media. In this work, we apply the BFS method for alloys to study the energetic pathway for subsurface Fe-Pt alloy formation upon deposition of Fe atoms on Pt(1 0 0), Pt(1 1 1), and vicinal Pt(9 9 7) substrates. The simulation results indicate preference for Fe atoms to occupy sites in the Pt subsurface layers and form an ordered alloy phase upon deposition on a low-index Pt surface. This behavior results in Pt surface segregation leading to nucleation of 31) Pt islands. However, the energetics behind deposition of Fe on Pt(9 9 7) indicate that Fe atoms prefer decoration of Pt step edges prior to formation of the ordered Fe-Pt surface alloy, where the ordered alloy is observed to form at the edges of the monoatomic surface steps. In each case presented here, the results are in agreement with experiment, and the formation of a Fe-Pt subsurface alloy is explained by a simple analysis emerging from the competition between BFS strain and chemical energy contributions. (C) 2007 Elsevier B.V. All rights reserved. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77251 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. RP Bozzolo, G (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. EM GuillermoBozzolo@oai.org RI Pint, Cary/C-5053-2009; Pint, Cary/I-6785-2013 NR 24 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD OCT 31 PY 2007 VL 254 IS 1 SI SI BP 92 EP 95 DI 10.1016/j.apsusc.2007.07.045 PG 4 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 229JW UT WOS:000250800100021 ER PT J AU Canzian, A Mosca, H Bozzolo, G AF Canzian, Adrian Mosca, Hugo Bozzolo, Guillermo TI Modeling of the deposition of Ni and Pd on Mo(110) SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 13th International Conference on Solid Films and Surfaces (ICSFS 13) CY NOV 06-10, 2006 CL San Carlos de Bariloche, ARGENTINA SP Comis Nacl Energia Atom, ANPCyT, CONICET, CLAF DE semi-empirical methods; computer simulations; nickel; palladium molybdenum ID GROWTH; FILMS; SURFACE AB Recent experimental work on the deposition of fee metals on a bee substrate motivates this atomistic modeling analysis of Ni and Pd deposition on Mo(1 1 0). A detailed atom-by-atom analysis of the early stages of growth, focusing on the formation of surface alloys and 3D islands is presented, identifying the interactions leading to each type of behavior. Further analysis describes the growth pattern as a function of coverage. Temperature effects are studied via Monte Carlo simulations using the Bozzolo-Ferrante-Smith (BFS) method for alloys for the energetics. (C) 2007 Elsevier B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. UTN, Grp Caracterizac & Modelac Mat, Pacheco, Argentina. UA Fis, Comis Nacl Energia Atom, San Martin, Argentina. Ohio Aerosp Inst, Cleveland, OH 44142 USA. RP Bozzolo, G (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM Guillenno.H.Bozzolo@grc.nasa.gov NR 8 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD OCT 31 PY 2007 VL 254 IS 1 SI SI BP 392 EP 396 DI 10.1016/j.apsusc.2007.07.056 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 229JW UT WOS:000250800100089 ER PT J AU Louarn, P Kurth, WS Gurnett, DA Hospodarsky, GB Persoon, AM Cecconi, B Lecacheux, A Zarka, P Canu, P Roux, A Rucker, HO Farrell, WM Kaiser, ML Andre, N Harvey, C Blanc, M AF Louarn, P. Kurth, W. S. Gurnett, D. A. Hospodarsky, G. B. Persoon, A. M. Cecconi, B. Lecacheux, A. Zarka, P. Canu, P. Roux, A. Rucker, H. O. Farrell, W. M. Kaiser, M. L. Andre, N. Harvey, C. Blanc, M. TI Observation of similar radio signatures at Saturn and Jupiter: Implications for the magnetospheric dynamics SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID JOVIAN MAGNETOTAIL; PLASMA; EMISSIONS; GALILEO; MODEL AB We report on radio signatures observed at Saturn by the Cassini RPWS experiment which are strikingly similar to the Jovian ''energetic events'' observed by Galileo. They consist of sudden intensifications of the auroral radio emission ( SKR) followed by the detection of a periodic narrowband radiation which most likely originates from Saturn's plasma disk. About ten ''events'' have been observed in 2006, showing on average temporal scales similar to 3 times longer than their Jovian counterparts. We analyze the conditions of generation and the visibility of the narrowband radiation and conclude that the Kronian ''events'' are most likely associated with plasma evacuation from the disk. These observations provide new insights on the role of internal energy releases in Saturn's magnetosphere, known from other observations to be mainly driven by the solar wind. C1 Univ Toulouse 3, Ctr Etud Spatiale Rayonnements, CNRS, F-31400 Toulouse, France. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Observ Paris, F-92195 Meudon, France. Univ Versailles, Ctr Etud Environm & Planetaires, F-78140 Velizy Villacoublay, France. Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. European Space Technol Ctr, NL-2200 AG Noordwijk, Netherlands. RP Louarn, P (reprint author), Univ Toulouse 3, Ctr Etud Spatiale Rayonnements, CNRS, 9 Ave Colonel Roche, F-31400 Toulouse, France. RI Farrell, William/I-4865-2013; OI Hospodarsky, George/0000-0001-9200-9878; Kurth, William/0000-0002-5471-6202 NR 27 TC 27 Z9 27 U1 0 U2 0 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 OCT 31 PY 2007 VL 34 IS 20 AR L20113 DI 10.1029/2007GL030368 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 228BW UT WOS:000250703100001 ER PT J AU Bowman, RC Udovic, TJ Jensen, CM AF Bowman, Robert C., Jr. Udovic, Terrence J. Jensen, Craig M. TI Proceedings of the International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications (MH2006) October 1-6, 2006, Lahaina, Maui Island, Hawaii, USA - Preface SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Editorial Material C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Hawaii, Dept Chem, Honolulu, HI 96822 USA. RP Bowman, RC (reprint author), CALTECH, Jet Prop Lab, Mail Stop 79-24,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Robert.C.Bowman-Jr@jpl.nasa.gov OI Bowman, Robert/0000-0002-2114-1713 NR 0 TC 1 Z9 1 U1 1 U2 2 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 OCT 31 PY 2007 VL 446 SI SI BP 1 EP 2 DI 10.1016/j.jallcom.2007.06.047 PG 2 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900001 ER PT J AU Latroche, M Bowman, RC AF Latroche, M. Bowman, R. C., Jr. TI Crystal structure of the deuteride LaCu5D3.2 studied by neutron powder diffraction SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 01-06, 2006 CL Lahaina, HI SP GM Res & Dev, Hawaii Hydrogen Carriers, LLC, Hy Energy, LLC, Jet Propuls Lab, NIST Ctr Neutron Res, Suzuki Shokan Co, Ltd, Toyota Motor Sales DE intermetallics; hydrogen storage materials; gas-solid reactions; crystal structure and symmetry; X-ray and neutron diffraction ID HYDROGEN DIFFUSION; HYDRIDES; LANI5 AB The crystal structure of the deuteride LaCu5D3.2 is investigated by neutron powder diffraction. Analysis of the diffraction pattern shows that the initial CaCu5-type cell adopted by LaCu5 is not preserved upon deuteration. The pattern of the deuteride can be indexed in a new ortho-hexagonal cell (Pmma space group; a'= 2a = 10.7647 angstrom, b'= c = 4.1493 angstrom, c'= 2a+b = 9.4445 angstrom) leading to a cell volume four times larger than that of LaCu5. All possible hydrogen sites derived from the original CaCu5-type cell have been tested. Eight different sites have been found occupied by deuterium in 2c, 2e, two 4i and four 4j positions. At least 2.05 D atoms are found in tetrahedral positions and the remaining ones are in octahedral positions. The deuterium ordering is responsible for the symmetry lowering observed for the LaCu5 compound upon hydrogenation. It induces small shifts of the metallic atoms compared to the CaCu5-type structure leading to the supercell description. Finally, the impact of this structure on the unusual diffusion properties previously observed for LaCu5H3.4 during nuclear magnetic resonance (NMR) studies will be discussed. (C) 2006 Elsevier B.V. All rights reserved. C1 CNRS, UPR209, LCMTR, F-94320 Thiais, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Latroche, M (reprint author), CNRS, UPR209, LCMTR, 2-8 Rue H Dunant, F-94320 Thiais, France. EM michel.latroche@iscsa.cnrs.fr RI LATROCHE, MICHEL/L-6254-2014; OI LATROCHE, MICHEL/0000-0002-8677-8280; Bowman, Robert/0000-0002-2114-1713 NR 23 TC 2 Z9 2 U1 0 U2 0 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 OCT 31 PY 2007 VL 446 SI SI BP 11 EP 14 DI 10.1016/j.jallcom.2006.10.106 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900004 ER PT J AU Kabbour, H Ahn, CC Hwang, SJ Bowman, RC Graetz, J AF Kabbour, Houria Ahn, Channing C. Hwang, Son-Jong Bowman, Robert C., Jr. Graetz, Jason TI Direct synthesis and NMR characterization of calcium alanate SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 01-06, 2006 CL Lahaina, HI SP GM Res & Dev, Hawaii Hydrogen Carriers, LLC, Hy Energy, LLC, Jet Propuls Lab, NIST Ctr Neutron Res, Suzuki Shokan Co, Ltd, Toyota Motor Sales DE hydrogen storage materials; mechanochenucal synthesis; nuclear resonances ID 2 SOLVENT ADDUCTS; MAGNESIUM AB In this work, we present a new synthesis path and characterization results of the alanate, Ca(AlH4)(2). We have synthesized for the first time, calcium alanate, directly from starting mixtures of AlH3 and CaH2 using mechanosynthesis. Ca(AlH4)2 has been identified using magic angle spinning nuclear magnetic resonance (MAS-NMR) and Fourier transform infrared (FTIR) measurements. (C) 2007 Elsevier B.V. All rights reserved. C1 CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Brookhaven Natl Lab, Dept Energy Sci & Technol, Upton, NY 11973 USA. RP Kabbour, H (reprint author), CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. EM kabbour@caltech.edu OI Kabbour, Houria/0000-0002-9081-3261; Bowman, Robert/0000-0002-2114-1713 NR 9 TC 18 Z9 20 U1 1 U2 7 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 OCT 31 PY 2007 VL 446 SI SI BP 264 EP 266 DI 10.1016/j.jallcom.2006.12.050 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900055 ER PT J AU Graetz, J Reilly, JJ Kulleck, JG Bowman, RC AF Graetz, J. Reilly, J. J. Kulleck, J. G. Bowman, R. C. TI Kinetics and thermodynamics of the aluminum hydride polymorphs SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 01-06, 2006 CL Lahaina, HI SP GM Res & Dev, Hawaii Hydrogen Carriers, LLC, Hy Energy, LLC, Jet Propuls Lab, NIST Ctr Neutron Res, Suzuki Shokan Co, Ltd, Toyota Motor Sales DE energy storage materials; hydrogen storage materials; thermal analysis; calorimetry ID THERMAL-DECOMPOSITION; ALH3 AB Polymorphs of AlH3 were prepared by organometallic synthesis. We demonstrate that freshly synthesized, nonsolvated AlH3 releases approximately 10 wt% H-2 at desorption temperatures less than 100 degrees C. The decomposition kinetics, measured by isothermal hydrogen desorption between 30 and 140 degrees C, suggest that the rate of H-2 evolution is limited by nucleation and growth of the aluminum phase. The H-2 evolution rates for small crystallites of alpha and gamma-AlH3 (undoped) meet the DOE full flow target for a 50 kW fuel cell (1 gH(2)/s) above 114 degrees C (based on 100 kg AlH3). The decomposition thermodynamics were measured using differential scanning calorimetry and ex situ X-ray diffraction. The decomposition of the less stable polymorph, gamma-AlH3, occurs by an exothermic transformation to the a phase (similar to 100 degrees C followed by the decomposition of alpha-AlH3. A formation enthalpy of approximately -10 kJ/mol AIH(3) was measured for alpha-AlH3, which is in good agreement with previous experimental and calculated results. (C) 2006 Elsevier B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Energy Sci & Technol, Upton, NY 11973 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Graetz, J (reprint author), Brookhaven Natl Lab, Dept Energy Sci & Technol, Upton, NY 11973 USA. EM graetz@bnl.gov OI Bowman, Robert/0000-0002-2114-1713 NR 15 TC 55 Z9 56 U1 2 U2 12 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 OCT 31 PY 2007 VL 446 SI SI BP 271 EP 275 DI 10.1016/j.jallcom.2006.11.205 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900057 ER PT J AU Hwang, SJ Bowman, RC Graetz, J Reilly, JJ Langley, W Jensen, CM AF Hwang, Son-Jong Bowman, R. C., Jr. Graetz, Jason Reilly, J. J. Langley, W. Jensen, C. M. TI NMR studies of the aluminum hydride phases and their stabilities SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 01-06, 2006 CL Lahaina, HI SP GM Res & Dev, Hawaii Hydrogen Carriers, LLC, Hy Energy, LLC, Jet Propuls Lab, NIST Ctr Neutron Res, Suzuki Shokan Co, Ltd, Toyota Motor Sales DE hydrogen storage materials; gas-solid reactions; nuclear resonances ID TI-DOPED NAALH4; CRYSTAL-STRUCTURE; THERMAL-DECOMPOSITION; MULTIPLE-QUANTUM; MAS NMR; HYDROGEN; AL-27; ALH3; TRIHYDRIDE; POLYMORPHS AB Multinuclear and multidimensional solid state NMR techniques including magic-angle-spinning (MAS) and multiple-quantum (MQ) MAS experiments have been used to characterize various AlH3 samples. At least three distinct polymorphic AlH3 phases have been prepared by desolvating the alane etherate product from its organometallic synthesis. MAS-NMR spectra for the H-1 and Al-27 nuclei have been obtained on a variety of AlH3 samples that include the beta- and gamma-phases as well as the alpha-phase. Al-27 MAS NMR was found to respond with high sensitivity for showing differences in spatial arrangements of AlH6 octahedra in the three polymorphs studied. Based on the characteristic NMR signatures determined, phase transition of the gamma-AlH3 to the alpha-AlH3 was studied at room and high temperatures. Direct decomposition of the gamma-AlH3 to aluminum metal at room temperature was also unambiguously confirmed by NMR studies. (C) 2007 Elsevier B.V. All rights reserved. C1 CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Brookhaven Natl Lab, Dept Energy Sci & Technol, Upton, NY 11973 USA. Univ Hawaii, Dept Chem, Honolulu, HI 96822 USA. RP Hwang, SJ (reprint author), CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. EM sonjong@cheme.caltech.edu OI Bowman, Robert/0000-0002-2114-1713 NR 26 TC 23 Z9 23 U1 3 U2 25 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 OCT 31 PY 2007 VL 446 SI SI BP 290 EP 295 DI 10.1016/j.jallcom.2007.01.115 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900060 ER PT J AU Mendenhall, MP Bowman, RC Ivancic, TM Conradi, MS AF Mendenhall, Michael P. Bowman, Robert C., Jr. Ivancic, Timothy M. Conradi, Mark S. TI Rate of hydrogen motion in ni-substituted LaNi(5)H(x) from NMR SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 01-06, 2006 CL Lahaina, HI SP GM Res & Dev, Hawaii Hydrogen Carriers, LLC, Hy Energy, LLC, Jet Propuls Lab, NIST Ctr Neutron Res, Suzuki Shokan Co, Ltd, Toyota Motor Sales DE metal hydrides; diffusion; nuclear resonances ID NUCLEAR-MAGNETIC-RESONANCE; DIFFUSION; HYDRIDES; ISOTHERMS; PROTON; SYSTEM AB Partial substitution of Sn, Ge, or Si for Ni in LaNi(5)H(x) greatly enhances the stability under repeated hydrogen-cycling. Proton NMR relaxation measurements are reported here to determine the rates of H hopping in the substituted metals LaNi(4.6)M(0.4)H with M = Sn, Ge, and Si, for comparison to bare LaNi(5)H(x). The relaxation times T(2)* (FID), T(2) (Hahn echo), T(2)-CPMG, T(1), and T(1p) were determined from 130 to 375 K. The three substituents result in only small increases in the average rate of motion at a given temperature but with a broader distribution of rates over the many inequivalent H sites and hopping paths. Evidently, the average energy barriers along the paths for H motion are only little affected by these substituents. Changes of H content x produce only minor changes in the relaxation times. (C) 2007 Elsevier B.V. All rights reserved. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Conradi, MS (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA. EM msc@wuphys.wustl.edu OI Bowman, Robert/0000-0002-2114-1713 NR 17 TC 2 Z9 2 U1 0 U2 1 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 OCT 31 PY 2007 VL 446 SI SI BP 495 EP 498 DI 10.1016/j.jallcom.2006.12.139 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900105 ER PT J AU Conradi, MS Mendenhall, MP Ivancic, TM Carl, EA Browning, CD Notten, PHL Kalisvaart, WP Magusin, PCMM Bowman, RC Hwang, SJ Adolphi, NL AF Conradi, Mark S. Mendenhall, Michael P. Ivancic, Timothy M. Carl, Erik A. Browning, Caleb D. Notten, P. H. L. Kalisvaart, W. P. Magusin, Pieter C. M. M. Bowman, R. C., Jr. Hwang, Son-Jong Adolphi, Natalie L. TI NMR to determine rates of motion and structures in metal-hydrides SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 01-06, 2006 CL Lahaina, HI SP GM Res & Dev, Hawaii Hydrogen Carriers, LLC, Hy Energy, LLC, Jet Propuls Lab, NIST Ctr Neutron Res, Suzuki Shokan Co, Ltd, Toyota Motor Sales DE metal hydrides; diffusion; nuclear resonances ID ELECTROCHEMICAL HYDROGEN STORAGE; NUCLEAR-MAGNETIC-RESONANCE; YTTRIUM-DIHYDRIDE; CRYSTAL-STRUCTURE; SITE OCCUPANCY; THIN-FILMS; DIFFUSION; DIFFRACTION; ALLOYS; SYSTEM AB Measurements of nuclear magnetic resonance (NMR) relaxation times allow the rates of H and D atomic hopping in metal-hydrides to be determined. A first example compares the rates of H hopping in Mg65Sc35Pd2.4H220, a promising new battery electrode and storage alloy, to LaNi5Hx and to the end-members of the alloy system, ScH2 and MgH2. The motion of MgScH is more rapid than in the metallic ScH2 and the ionic MgH2, but slower than in LaNi5Hx. Magic-angle spinning (MAS) NMR of metal-deuterides is a newer method that can resolve inequivalent D atoms and measure the rate of diffusive exchange between the sites. Examples include the tetrahedral and octahedral sites in YD2+x and D in ZrNiDx. (C) 2006 Elsevier B.V. All rights reserved. C1 Washington Univ, Dept Phys 1105, St Louis, MO 63130 USA. Philips Res Labs, NL-5656 AE Eindhoven, Netherlands. Eindhoven Univ Technol, NL-5600 MB Eindhoven, Netherlands. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. New Mexico Resonance, Albuquerque, NM 87106 USA. RP Ivancic, TM (reprint author), Washington Univ, Dept Phys 1105, St Louis, MO 63130 USA. EM msc@wuphys.wustl.edu RI Magusin, Pieter/F-5724-2016; OI Bowman, Robert/0000-0002-2114-1713 NR 28 TC 35 Z9 35 U1 1 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 OCT 31 PY 2007 VL 446 SI SI BP 499 EP 503 DI 10.1016/j.jallcom.2006.11.149 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900106 ER PT J AU Wilson, PR Bowman, RC Mora, JL Reiter, JW AF Wilson, P. R. Bowman, R. C., Jr. Mora, J. L. Reiter, J. W. TI Operation of a PEM fuel cell with LaN4.8Sn0.2 hydride beds SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 01-06, 2006 CL Lahaina, HI SP GM Res & Dev, Hawaii Hydrogen Carriers, LLC, Hy Energy, LLC, Jet Propuls Lab, NIST Ctr Neutron Res, Suzuki Shokan Co, Ltd, Toyota Motor Sales DE intermetallics; hydrogen storage materials; fuel cells; gas-solid reactions ID DEGRADATION AB A series of measurements were performed using metal hydride sorbent beds to operate a 1.0 kW capacity proton electrolyte membrane (PEM) fuel cell hybrid power system. Two sorbent beds were filled with LaM4.78Sn0.22 alloy and each unit had a maximum storage capacity of similar to 280 sL hydrogen. A single sorbent bed was able to supply hydrogen gas for similar to 20-25 min operation at 30 A net current and similar to 900 W output power. These hydride beds were also capable of supplying sufficient hydrogen flows and pressures to produce up to similar to 1.1 kW output power from the fuel cell for shorter durations. Good correlations for hydrogen consumption rates and power outputs were obtained and boundaries parameters for continual operation were identified. Various input and output parameters were recorded and analyzed to relate hydride bed, fuel cell, and battery behavior and assess their dynamic interactions. (C) 2007 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Swales Aerosp, Pasadena, CA 91107 USA. RP Bowman, RC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM robert.c.bowman-jr@jpl.nasa.gov OI Bowman, Robert/0000-0002-2114-1713 NR 10 TC 12 Z9 12 U1 0 U2 0 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 OCT 31 PY 2007 VL 446 SI SI BP 676 EP 680 DI 10.1016/j.jallcom.2007.02.162 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900143 ER PT J AU Reiter, JW Karlmann, PB Bowman, RC Prina, M AF Reiter, J. W. Karlmann, P. B. Bowman, R. C., Jr. Prina, M. TI Performance and degradation of gas-gap heat switches in hydride compressor beds SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 01-06, 2006 CL Lahaina, HI SP GM Res & Dev, Hawaii Hydrogen Carriers, LLC, Hy Energy, LLC, Jet Propuls Lab, NIST Ctr Neutron Res, Suzuki Shokan Co, Ltd, Toyota Motor Sales DE hydrogen storage materials; intermetallics; gas-solid reactions AB A closed-cycle gas-gap heat switch (GGHS) can function as a variable vacuum dewar for metal hydride compressors to reduce nominal input power to each compressor by similar to 80% over its lifetime without the use of any moving parts. The hydrogen gas pressure in each GGHS is varied with an independent actuator containing ZrNi hydride. As the GGHS must attain low H-2 gas pressure in its insulating "off" state to function reliably, any accumulation of additional gas in the GGHS can compromise the vacuum causing parasitic heat losses within the system. The effects of such accumulations have been found to be a combination of outgassing from metallic components and hydrogen permeation through the walls of the high-pressure compressor bed when it is heated between 290 K and 670 K. This accumulation has been volumetrically measured over a wide range of operating temperatures and pressures on different versions of hydride compressor beds to provide hydrogen accumulation rates in the GGHS. Correlations with literature values are given, addressing the performance of stainless steel in terms of permeation and outgassing of hydrogen gas. (C) 2007 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Swales Aerosp, Pasadena, CA 91105 USA. RP Reiter, JW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Joseph.W.Reiter@jpl.nasa.gov OI Bowman, Robert/0000-0002-2114-1713 NR 15 TC 3 Z9 3 U1 0 U2 0 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 OCT 31 PY 2007 VL 446 SI SI BP 713 EP 717 DI 10.1016/j.jallcom.2007.04.072 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900150 ER PT J AU Pearson, D Bowman, R Prina, M Wilson, P AF Pearson, D. Bowman, R. Prina, M. Wilson, P. TI The Planck sorption cooler: Using metal hydrides to produce 20 K SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications CY OCT 01-06, 2006 CL Lahaina, HI SP GM Res & Dev, Hawaii Hydrogen Carriers, LLC, Hy Energy, LLC, Jet Propuls Lab, NIST Ctr Neutron Res, Suzuki Shokan Co, Ltd, Toyota Motor Sales DE intermetallics; hydrogen storage materials; hydrogen absorbing materials; metal hydrides ID DEGRADATION AB The Jet Propulsion Laboratory has built and delivered two continuous, closed cycle, hydrogen Joule-Thomson (J-T) cryocoolers for the ESA Planck mission, which will measure the anisotropy in the cosmic microwave background. The metal hydride compressor consists of six sorbent beds containing LaNi4.78Sn0.22 alloy and a low-pressure storage bed of the same material. Each sorbent bed contains a separate gas-gap heat switch that couples or isolates the bed with radiators during the compressor operating cycle. ZrNiHx, hydride is used in this heat switch. The Planck compressor produces hydrogen gas at a pressure of 48 bar by heating the hydride to similar to 450 K. This gas passes through a cryogenic cold-end consisting of a tube-in-tube heat exchanger. three pre-cooling stages to bring the gas to nominally 52 K, a J-T value to expand the gas into the two-phase regime at similar to 20 K. and two liquid-vapor heat exchangers that must remove 190 and 646 mW of heat, respectively. Gas evaporated from the liquid phase is recovered by three hydride beds at -0.3 bar and 270 K. Each cooler was designed to provide I W cooling at -20 K for a total input power of 470 W, excluding electronics. The performance of these coolers is mainly a function of the compressor interface and final pre-cooling stage temperatures. We present results from the testing of these two coolers for the input power, cooling power, temperature, and temperature fluctuations over the flight allowable ranges for these interfaces. (C) 2007 Published by Elsevier B.V. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Pearson, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM david.pearson@jpl.nasa.gov OI Bowman, Robert/0000-0002-2114-1713 NR 9 TC 8 Z9 8 U1 0 U2 2 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 OCT 31 PY 2007 VL 446 SI SI BP 718 EP 722 DI 10.1016/j.jallcom.2006.11.202 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 229RW UT WOS:000250822900151 ER PT J AU Gianelli, SM Carlson, BE Lacis, AA AF Gianelli, S. M. Carlson, B. E. Lacis, A. A. TI Using EOF analysis to qualitatively analyze, and identify inhomogeneities in, data from ground-based aerosol monitoring instruments SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OPTICAL DEPTH AB Empirical Orthogonal Function ( EOF) analysis is performed on ground-based shadowband radiometer and Sun photometer data. The data come from Multifilter Rotating Shadowband Radiometer ( MFRSR) instruments located at the central and extended facilities of the Southern Great Plains ( SGP) research site of the Department of Energy's Atmospheric Radiation Measurement ( ARM) program, as well as the Rotating Shadowband Spectroradiometer ( RSS) 102 and 105 and the CIMEL Sun photometer CSPHOT located at the central facility at SGP. The EOFs show the variability in total aerosol optical depth and provide some qualitative information on the separation of the coarse and fine aerosol modes. In addition, as has been demonstrated previously with satellite data, EOF analysis also exposes several flaws and inconsistencies within the ground-based data sets. These inhomogeneities include optical depth anomalies in some MFRSR filters, wavelength shifts in the RSS, and problems with the data transmitter of the CIMEL instrument. Therefore EOF analysis is shown to be a quick and effective means not only of assessing the general aerosol behavior in the air above a particular monitoring instrument, but also of identifying both known and unanticipated influences on the data coming from within the instrument itself. C1 Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. NASA, Goddard Inst Space Studies, New York, NY 10027 USA. RP Gianelli, SM (reprint author), Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. EM smg58@columbia.edu RI Lacis, Andrew/D-4658-2012; Carlson, Barbara/D-8319-2012 NR 19 TC 1 Z9 1 U1 0 U2 2 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 OCT 30 PY 2007 VL 112 IS D20 AR D20210 DI 10.1029/2006JD008300 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 228CK UT WOS:000250704500005 ER PT J AU Cress, CD Hubbard, SM Landi, BJ Raffaelle, RP Wilt, DM AF Cress, Cory D. Hubbard, Seth M. Landi, Brian J. Raffaelle, Ryne P. Wilt, David M. TI Quantum dot solar cell tolerance to alpha-particle irradiation SO APPLIED PHYSICS LETTERS LA English DT Article ID DAMAGE AB The effects of alpha-particle irradiation on an InAs quantum dot (QD) array and GaAs-based InAs QD solar cells were investigated. Using photoluminescence (PL) mapping, the PL intensity at 872 and 1120 nm, corresponding to bulk GaAs and InAs QD emissions, respectively, were measured for a five-layer InAs QD array which had a spatially varying total alpha-particle dose. The spectral response and normalized current-voltage parameters of the solar cells, measured as a function of alpha-particle fluence, were used to investigate the change in device performance between GaAs solar cells with and without InAs QDs. (C) 2007 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 Cress, CD (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 15 TC 24 Z9 24 U1 1 U2 6 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 OCT 29 PY 2007 VL 91 IS 18 AR 183108 DI 10.1063/1.2803854 PG 3 WC Physics, Applied SC Physics GA 227FW UT WOS:000250643600077 ER PT J AU Hsu, SY Chang, CL AF Hsu, Su-Yuen Chang, Chau-Lyan TI Mesh deformation based on fully stressed design: The method and 2-D examples SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE mesh deformation; shape optimization; fluid-structure interaction; fully stressed design; finite element analysis; linear elasticity; strain failure; equivalent strain; Tresca failure criterion ID UNSTRUCTURED DYNAMIC MESHES AB Mesh deformation in response to redefined boundary geometry is a frequently encountered task in shape optimization and analysis of fluid-structure interaction. We propose a simple and concise method for deforming meshes defined with three-node triangular or four-node tetrahedral elements. The mesh deformation method is suitable for large boundary movement. The approach requires two consecutive linear elastic finite element analyses of an isotropic continuum using a prescribed displacement at the mesh boundaries. The first analysis is performed with homogeneous elastic property and the second with inhomogeneous elastic property. The fully stressed design is employed with a vanishing Poisson ratio and a proposed form of equivalent strain (modified Tresca equivalent strain) to calculate, from the strain result of the first analysis, an element-specific Young's modulus for the second analysis. The theoretical aspect of the proposed method, its convenient numerical implementation using a typical linear elastic finite element code in conjunction with very minor extra coding for data processing, and results for examples of large deformation of 2-D meshes are presented in this paper. Copyright (c) 2007 John Wiley & Sons, Ltd. C1 NASA, Langley Res Ctr, Computat Aerosci Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Struct Mech & Concepts Branch, Hampton, VA 23681 USA. RP Chang, CL (reprint author), NASA, Langley Res Ctr, Computat Aerosci Branch, Hampton, VA 23681 USA. EM chau-lyan.chang@nasa.gov NR 15 TC 6 Z9 8 U1 0 U2 3 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 OCT 29 PY 2007 VL 72 IS 5 BP 606 EP 629 DI 10.1002/nme.2027 PG 24 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 224AG UT WOS:000250416800005 ER PT J AU Dilley, CE Stephen, MA Savage-Leuchs, MP AF Dilley, C. E. Stephen, M. A. Savage-Leuchs, M. P. TI High SBS-threshold, narrowband, erbium co-doped with ytterbium fiber amplifier pulses frequency-doubled to 770 nm SO OPTICS EXPRESS LA English DT Article ID STIMULATED BRILLOUIN-SCATTERING; SUPPRESSION; DESIGN AB We present results of pulsed, narrowband amplification at 1540.6nm using a polarization maintaining, large mode area gain fiber codoped with erbium and ytterbium. At a repetition rate of 55 kHz, 2.9 W of average 1540.6nm power were generated with a pulse duration of 136 ns, corresponding to an SBS free peak power of 360 W. The amplified signal was frequency doubled in peridically poled potassium titanyl phosphate and conversion efficiencies of up to 56% were generated. When varying the repetition rate between 55-150 kHz the conversion efficiency changed from 56% to 35% due to the limited pump power. (C) 2007 Optical Society of America. C1 Aculight Corp, Bothell, WA USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Dilley, CE (reprint author), Aculight Corp, 22121 20th Ave SE, Bothell, WA USA. EM matthias.savage-leuchs@aculight.com NR 13 TC 27 Z9 27 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD OCT 29 PY 2007 VL 15 IS 22 BP 14389 EP 14395 DI 10.1364/OE.15.014389 PG 7 WC Optics SC Optics GA 235HD UT WOS:000251223400013 PM 19550717 ER PT J AU Hu, Y Powell, K Vaughan, M Tepte, C Weimer, C Beherenfeld, M Young, S Winker, D Hostetler, C Hunt, W Kuehn, R Flittner, D Cisewski, M Gibson, G Lin, B MacDonnell, D AF Hu, Yongxiang Powell, Kathy Vaughan, Mark Tepte, Charles Weimer, Carl Beherenfeld, Mike Young, Stuart Winker, David Hostetler, Chris Hunt, William Kuehn, Ralph Flittner, David Cisewski, Mike Gibson, Gary Lin, Bing MacDonnell, David TI Elevation information in tail (EIT) technique for lidar altimetry SO OPTICS EXPRESS LA English DT Article ID LASER ALTIMETRY; TOPOGRAPHY AB A technique we refer to as Elevation Information in Tail (EIT) has been developed to provide improved lidar altimetry from CALIPSO lidar data. The EIT technique is demonstrated using CALIPSO data and is applicable to other similar lidar systems with low- pass filters. The technique relies on an observed relation between the shape of the surface return signals (peak shape) and the detector photo-multiplier tube transient response (transient response tail). Application of the EIT to CALIPSO data resulted in an order of magnitude or better improvement in the CALIPSO land surface 30-meter elevation measurements. The results of EIT compared very well with the National Elevation Database (NED) high resolution elevation maps, and with the elevation measurements from the Shuttle Radar Topography Mission (SRTM). (C) 2007 Optical Society of America. C1 NASA, Langley Res Ctr, Climate Sci Branch, Hampton, VA 23681 USA. SSAI, Hampton, VA 23666 USA. Ball Aerosp & Tech Corp, Boulder, CO 80301 USA. Oregon State Univ, Corvallis, OR 97331 USA. CSIRO Marine & Atmospher Res, Aspendale, Vic 3195, Australia. RP Hu, Y (reprint author), NASA, Langley Res Ctr, Climate Sci Branch, Hampton, VA 23681 USA. EM yongxiang.hu-1@nasa.gov RI Young, Stuart/A-8641-2011; Hu, Yongxiang/K-4426-2012 OI Young, Stuart/0000-0001-6434-9816; NR 8 TC 16 Z9 17 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD OCT 29 PY 2007 VL 15 IS 22 BP 14504 EP 14515 DI 10.1364/OE.15.014504 PG 12 WC Optics SC Optics GA 235HD UT WOS:000251223400025 PM 19550729 ER PT J AU Martin, W Russell, MJ AF Martin, William Russell, Michael J. TI On the origin of biochemistry at an alkaline hydrothermal vent SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Review DE origin of life; thioesters; acetyl phosphate; formyl phosphate; carbamoyl phosphate; carboxyphosphate ID PYRUVATE-FERREDOXIN OXIDOREDUCTASE; DEHYDROGENASE/ACETYL-COA SYNTHASE; CARBAMOYL-PHOSPHATE SYNTHETASE; ARCHAEON PYROCOCCUS-FURIOSUS; ESCHERICHIA-COLI K-12; IRON-SULFUR CLUSTERS; COENZYME-M-REDUCTASE; CARBON-MONOXIDE; FORMYLMETHANOFURAN DEHYDROGENASE; AMINO-ACIDS AB Amodel for the origin of biochemistry at an alkaline hydrothermal vent has been developed that focuses on the acetyl-CoA (Wood-Ljungdahl) pathway of CO(2) fixation and central intermediary metabolism leading to the synthesis of the constituents of purines and pyrimidines. The idea that acetogenesis and methanogenesis were the ancestral forms of energy metabolism among the first free-living eubacteria and archaebacteria, respectively, stands in the foreground. The synthesis of formyl pterins, which are essential intermediates of the Wood-Ljungdahl pathway and purine biosynthesis, is found to confront early metabolic systems with steep bioenergetic demands that would appear to link some, but not all, steps of CO2 reduction to geochemical processes in or on the Earth's crust. Inorganically catalysed prebiotic analogues of the core biochemical reactions involved in pterin-dependent methyl synthesis of the modern acetyl-CoA pathway are considered. The following compounds appear as probable candidates for central involvement in prebiotic chemistry: metal sulphides, formate, carbon monoxide, methyl sulphide, acetate, formyl phosphate, carboxy phosphate, carbamate, carbamoyl phosphate, acetyl thioesters, acetyl phosphate, possibly carbonyl sulphide and eventually pterins. Carbon might have entered early metabolism via reactions hardly different from those in the modern Wood-Ljungdahl pathway, the pyruvate synthase reaction and the incomplete reverse citric acid cycle. The key energy rich intermediates were perhaps acetyl thioesters, with acetyl phosphate possibly serving as the universal metabolic energy currency prior to the origin of genes. Nitrogen might have entered metabolism as geochemical NH(3) via two routes: the synthesis of carbamoyl phosphate and reductive transaminations of alpha-keto acids. Together with intermediates of methyl synthesis, these two routes of nitrogen assimilation would directly supply all intermediates of modern purine and pyrimidine biosynthesis. Thermodynamic considerations related to formyl pterin synthesis suggest that the ability to harness a naturally pre-existing proton gradient at the vent -ocean interface via an ATPase is older than the ability to generate a proton gradient with chemistry that is specified by genes. C1 Univ Dusseldorf, Inst Bot, D-40225 Dusseldorf, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Martin, W (reprint author), Univ Dusseldorf, Inst Bot, D-40225 Dusseldorf, Germany. EM w.martin@uni-duesseldorf.de RI Martin, William/C-5680-2008; Martin, William /O-5446-2015 OI Martin, William /0000-0003-1478-6449 NR 225 TC 209 Z9 223 U1 16 U2 120 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8436 J9 PHILOS T R SOC B JI Philos. Trans. R. Soc. B-Biol. Sci. PD OCT 29 PY 2007 VL 362 IS 1486 BP 1887 EP 1925 DI 10.1098/rstb.2006.1881 PG 39 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 211IE UT WOS:000249516700016 PM 17255002 ER PT J AU Chaston, CC Wilber, M Mozer, FS Fujimoto, M Goldstein, ML Acuna, M Reme, H Fazakerley, A AF Chaston, C. C. Wilber, M. Mozer, F. S. Fujimoto, M. Goldstein, M. L. Acuna, M. Reme, H. Fazakerley, A. TI Mode conversion and anomalous transport in Kelvin-Helmholtz vortices and kinetic Alfven waves at the earth's magnetopause SO PHYSICAL REVIEW LETTERS LA English DT Article ID LATITUDE BOUNDARY-LAYER; PLASMA; ACCELERATION AB Observations at the Earth's magnetopause identify mode conversion from surface to kinetic Alfven waves at the Alfven resonance. Kinetic Alfven waves radiate into the magnetosphere from the resonance with parallel scales up to the order of the geomagnetic field- line length and spectral energy densities obeying a k(perpendicular to)(-24) power law. Amplitudes at the Alfven resonance are sufficient to both demagnetize ions across the magnetopause and provide field- aligned electron bursts. These waves provide diffusive transport across the magnetopause sufficient for boundary layer formation. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. ISAS JAXA, Space Plasma Div, Kanagawa, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CESR, Toulouse, France. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. RP Chaston, CC (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Goldstein, Melvyn/B-1724-2008 NR 27 TC 35 Z9 36 U1 2 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 26 PY 2007 VL 99 IS 17 AR 175004 DI 10.1103/PhysRevLett.99.175004 PG 4 WC Physics, Multidisciplinary SC Physics GA 225GV UT WOS:000250506000041 PM 17995342 ER PT J AU Gorham, PW Barwick, SW Beatty, JJ Besson, DZ Binns, WR Chen, C Chen, P Clem, JM Connolly, A Dowkontt, PF DuVernois, MA Field, RC Goldstein, D Goodhue, A Hast, C Hebert, CL Hoover, S Israel, MH Kowalski, J Learned, JG Liewer, KM Link, JT Lusczek, E Matsuno, S Mercurio, B Miki, C Miocinovic, P Nam, J Naudet, CJ Ng, J Nichol, R Palladino, K Reil, K Romero-Wolf, A Rosen, M Ruckman, L Saltzberg, D Seckel, D Varner, GS Walz, D Wu, F AF Gorham, P. W. Barwick, S. W. Beatty, J. J. Besson, D. Z. Binns, W. R. Chen, C. Chen, P. Clem, J. M. Connolly, A. Dowkontt, P. F. DuVernois, M. A. Field, R. C. Goldstein, D. Goodhue, A. Hast, C. Hebert, C. L. Hoover, S. Israel, M. H. Kowalski, J. Learned, J. G. Liewer, K. M. Link, J. T. Lusczek, E. Matsuno, S. Mercurio, B. Miki, C. Miocinovic, P. Nam, J. Naudet, C. J. Ng, J. Nichol, R. Palladino, K. Reil, K. Romero-Wolf, A. Rosen, M. Ruckman, L. Saltzberg, D. Seckel, D. Varner, G. S. Walz, D. Wu, F. TI Observations of the askaryan effect in ice SO PHYSICAL REVIEW LETTERS LA English DT Article ID COHERENT RADIO EMISSION; NEUTRINO DETECTION; RADIATION; SHOWERS; PULSES; AMANDA; CHARGE AB We report on observations of coherent, impulsive radio Cherenkov radiation from electromagnetic showers in solid ice. This is the first observation of the Askaryan effect in ice. As part of the complete validation process for the ANITA experiment, we performed an experiment at the Stanford Linear Accelerator Center in June 2006 using a 7.5 metric ton ice target. We measure for the first time the largescale angular dependence of the radiation pattern, a major factor in determining the solid-angle acceptance of ultrahigh-energy neutrino detectors. C1 Univ Hawaii, Dept Phys & Astron, Manoa, HI 96822 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Univ Delaware, Newark, DE 19716 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gorham, PW (reprint author), Univ Hawaii, Dept Phys & Astron, Manoa, HI 96822 USA. RI Nichol, Ryan/C-1645-2008; Vieregg, Abigail/D-2287-2012; Connolly, Amy/J-3958-2013; Beatty, James/D-9310-2011; OI Beatty, James/0000-0003-0481-4952; Lusczek, Elizabeth/0000-0003-4680-965X NR 25 TC 64 Z9 65 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 26 PY 2007 VL 99 IS 17 AR 171101 DI 10.1103/PhysRevLett.99.171101 PG 5 WC Physics, Multidisciplinary SC Physics GA 225GV UT WOS:000250506000014 PM 17995315 ER PT J AU Gosling, JT Eriksson, S Blush, LM Phan, TD Luhmann, JG McComas, DJ Skoug, RM Acuna, MH Russell, CT Simunac, KD AF Gosling, J. T. Eriksson, S. Blush, L. M. Phan, T. D. Luhmann, J. G. McComas, D. J. Skoug, R. M. Acuna, M. H. Russell, C. T. Simunac, K. D. TI Five spacecraft observations of oppositely directed exhaust jets from a magnetic reconnection X-line extending > 4.26 x 10(6) km in the solar wind at 1 AU SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EXPLORER AB Observations of oppositely directed plasma jets within an extended, bifurcated current sheet in the solar wind by a flotilla of five well- separated spacecraft ( STEREO A and B, ACE, Wind and Geotail) on 11 March 2007 demonstrate that magnetic reconnection X- lines in the solar wind can extend to distances at least as great as 4.26 x 10 6 km ( 0.0284 AU) in the presence of a significant and variable guide field. The observations also indicate that reconnection in the solar wind can persist for at least 5 hours and 20 minutes. These minimum values are the largest yet obtained from direct measurements of reconnection exhaust flows in a space plasma. Both dynamic processes in the reconnection region and the spherical expansion of the solar wind probably contribute to the production of long X- lines in the solar wind. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. SW Res Inst, Space Sci & Engn Div, San Antonio, TX 78228 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gosling, JT (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. EM jack.gosling@lasp.colorado.edu OI Eriksson, Stefan/0000-0002-5619-1577 NR 18 TC 35 Z9 36 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 OCT 25 PY 2007 VL 34 IS 20 AR L20108 DI 10.1029/2007GL031492 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 225MB UT WOS:000250520900008 ER PT J AU Webber, WR Cummings, AC McDonald, FB Stone, EC Heikkila, B Lal, N AF Webber, W. R. Cummings, A. C. McDonald, F. B. Stone, E. C. Heikkila, B. Lal, N. TI Passage of a large interplanetary shock from the inner heliosphere to the heliospheric termination shock and beyond: Its effects on cosmic rays at Voyagers 1 and 2 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OUTER HELIOSPHERE; RADIO-EMISSION; HELIOSHEATH AB Using data from the charged particle telescopes on V1 and V2 we have followed the progress of a large interplanetary shock as it passes V2 at a distance of 79 AU at about 2006.16, then later crosses the heliospheric termination shock finally reaching V1 at a distance similar to 100 AU. A decrease similar to 15% is observed in the V2 > 70 MeV rate starting at 2006.19 and three smaller decreases starting at 2006.29, 2006.50 and 2006.86 are observed at V1. From the timing of the first two decreases at V1 we are able to determine that the average shock speed slows down at the termination shock from similar to 600 km s(-1) to 210 - 270 km s(-1). Decreases of similar to 30 - 50% in anomalous He and galactic H are observed at V2 when the shock passes this location inside the termination shock. Smaller decreases are observed for both of these components when the weakened interplanetary shock passes V1 at 2006.50. These results define the extent and magnitude of solar modulation effects on cosmic rays caused by transients both inside and beyond the termination shock. C1 New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Downs Lab, Pasadena, CA 91125 USA. RP Webber, WR (reprint author), New Mexico State Univ, Dept Astron, POB 30001,1320 Frenger St, Las Cruces, NM 88003 USA. EM bwebber@nmsu.edu NR 15 TC 9 Z9 9 U1 0 U2 0 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 OCT 25 PY 2007 VL 34 IS 20 AR L20107 DI 10.1029/2007GL031339 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 225MB UT WOS:000250520900006 ER PT J AU Chuang, FC Beyer, RA McEwen, AS Thomson, BJ AF Chuang, Frank C. Beyer, Ross A. McEwen, Alfred S. Thomson, Bradley J. TI HiRISE observations of slope streaks on Mars SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SURFACE-PROPERTIES; ORBITER CAMERA; MISSION; DUST AB Images from the High Resolution Imaging Science Experiment have revealed new details on the morphologic and topographic characteristics of slope streaks on Mars. Over 1500 HiRISE images were analyzed with 78 unique image sites having slope streaks. Images with low sun illumination reveal that dark slope streaks have topographic relief where streaked surfaces are lower than their surroundings. Slope streaks often initiate below localized features such as rock outcrops, individual boulders, and impact craters. They are also abundant in great numbers within the blast zones of small young impact craters 10 50 m in diameter. These observations suggest that slope streaks can be triggered by localized disturbances such as rockfalls and impact blasts. Seismic activity from external ( e. g., impacts) or internal forces could also trigger slope streaks. The topographic relief and triggering mechanisms of slope streaks seem to best fit models that involve dry dust avalanches. Martian slope streaks and meters-thick avalanche scars are part of a continuum of active mass-wasting features at meter to sub-meter scales. C1 Planetary Sci Inst, Tucson, AZ 85719 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. Search Extraterr Intelligence Inst, Carl Sagan Ctr, Mountain View, CA USA. RP Chuang, FC (reprint author), Planetary Sci Inst, 1700 E Fd Lowell Rd,Suite 106, Tucson, AZ 85719 USA. EM chuang@psi.edu OI Thomson, Bradley/0000-0001-8635-8932; Beyer, Ross/0000-0003-4503-3335 NR 22 TC 18 Z9 18 U1 0 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 OCT 24 PY 2007 VL 34 IS 20 AR L20204 DI 10.1029/2007GL031111 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 225MA UT WOS:000250520800003 ER PT J AU Gjerloev, JW Greenwald, RA Waters, CL Takahashi, K Sibeck, D Oksavik, K Barnes, R Baker, J Ruohoniemi, JM AF Gjerloev, J. W. Greenwald, R. A. Waters, C. L. Takahashi, K. Sibeck, D. Oksavik, K. Barnes, R. Baker, J. Ruohoniemi, J. M. TI Observations of Pi2 pulsations by the Wallops HF radar in association with substorm expansion SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OBLIQUE MAGNETIC-FIELDS; ULF WAVES; PI-2 PULSATIONS; PROPAGATION; STARE; IONOSPHERE AB We report the first sub-auroral Pi2 pulsations observations by a SuperDARN type HF radar. The Wallops radar LOS measurements obtained at ionospheric altitudes, similar to 56 degrees magnetic latitude, 23 hour magnetic local time, are shown to be highly correlated with ground magnetic field perturbations obtained at Ottawa. The period of the Pi2 pulsations is 118 s and the m-number is similar to 2.3. The availability of both ionospheric LOS measurements and ground based magnetic field perturbations enable us to constrain the properties of the wave. A predominantly shear Alfven mode wave is able to explain both the amplitude and phase relations of our observations. Although the solar wind dynamic pressure is fairly stable the IMF Bz is highly variable thereby preventing an unambiguous identification of a solar wind trigger. Rather, magnetotail observations of a clear dipolarization and an intensification of the auroral westward electrojet producing a modest ground magnetic bay indicate that the wave is associated with the onset of a weak substorm. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Newcastle, Sch Math & Phys Sci, Newcastle, NSW 2308, Australia. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Gjerloev, JW (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM jesper.gjerloev@jhuapl.edu RI Waters, Colin/B-3086-2011; Sibeck, David/D-4424-2012; OI Waters, Colin/0000-0003-2121-6962; Oksavik, Kjellmar/0000-0003-4312-6992; Greenwald, Raymond/0000-0002-7421-5536 NR 16 TC 10 Z9 10 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 OCT 23 PY 2007 VL 34 IS 20 AR L20103 DI 10.1029/2007GL030492 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 225LZ UT WOS:000250520700004 ER PT J AU Matteini, L Landi, S Hellinger, P Pantellini, F Maksimovic, M Velli, M Goldstein, BE Marsch, E AF Matteini, Lorenzo Landi, Simone Hellinger, Petr Pantellini, Filippo Maksimovic, Milan Velli, Marco Goldstein, Bruce E. Marsch, Eckart TI Evolution of the solar wind proton temperature anisotropy from 0.3 to 2.5 AU SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HYBRID SIMULATIONS; CYCLOTRON WAVES; VELOCITY; ION; INSTABILITIES; DISTRIBUTIONS; DRIFT AB We report an analysis of the proton temperature anisotropy evolution from 0.3 to 2.5 AU based on the Helios and Ulysses observations. With increasing distance the fast wind data show a path in the parameter space (beta(parallel to p), T-perpendicular to p/T-parallel to p). The first part of the trajectory is well described by an anticorrelation between the temperature anisotropy T-perpendicular to p/T-parallel to p and the proton parallel beta, while after 1 AU the evolution with distance in the parameter space changes and the data result in agreement with the constraints derived by a fire hose instability. The slow wind data show a more irregular behavior, and in general it is not possible to recover a single evolution path. However, on small temporal scale we find that different slow streams populate different regions of the parameter space, and this suggests that when considering single streams also the slow wind follows some possible evolution path. C1 Univ Florence, Dipartimento Astron & Sci Spazio, I-50125 Florence, Italy. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Acad Sci Czech Republic, Inst Atmospher Phys, Prague 14131 4, Czech Republic. Observ Paris, F-92125 Meudon, France. Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. RP Matteini, L (reprint author), Univ Florence, Dipartimento Astron & Sci Spazio, Largo E Fermi 2, I-50125 Florence, Italy. EM matteini@arcetri.astro.it; slandi@arcetri.astro.it; petr.hellinger@ufa.cas.cz; filippo.pantellini@obspm.fr; milan.maksimovic@obspm.fr; velli@arcetri.astro.it; bruce.e.goldstein@jpl.nasa.gov; marsch@mps.mpg.de RI Hellinger, Petr/F-5267-2014; Landi, Simone/G-7282-2015 OI Hellinger, Petr/0000-0002-5608-0834; Landi, Simone/0000-0002-1322-8712 NR 18 TC 105 Z9 105 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 OCT 23 PY 2007 VL 34 IS 20 AR L20105 DI 10.1029/2007GL030920 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 225LZ UT WOS:000250520700005 ER PT J AU Kuvshinov, A Manoj, C Olsen, N Sabaka, T AF Kuvshinov, Alexei Manoj, Chandrasekharan Olsen, Nils Sabaka, Terence TI On induction effects of geomagnetic daily variations from equatorial electrojet and solar quiet sources at low and middle latitudes SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ELECTROMAGNETIC INDUCTION; GLOBAL INDUCTION; PENINSULAR INDIA; MAGNETIC-FIELD; C-RESPONSES; CHAMP DATA; SURFACE; OCEAN; ANOMALIES; EARTH AB We investigate the spatiotemporal behavior of the magnetic vertical component, Z, of the daily ionospheric current systems: the equatorial electrojet ( EEJ) and solar quiet ( Sq) variations, considering induction in the mantle and oceans. The inducing EEJ and Sq current systems are provided by the comprehensive model of Sabaka et al. ( 2004). The three- dimensional ( 3- D) conductivity model of the Earth includes oceans of laterally variable conductance and a spherical conductor ( 1- D) underneath. Our model studies demonstrate that induction effects in Z due to the EEJ are negligible everywhere inland for all local times. At CHAMP altitude ( 400 km) the magnetic signal induced by EEJ above the oceans does not exceed 2 - 5% of the external field during local noon. This, in particular, means that considering the induction effects is not necessary when modeling the EEJ current strength from inland surface magnetic measurements and/ or satellite data. As expected, induction in the oceans strongly affects the Sq field. The model studies show that the anomalous induction effect ( defined as the difference between results obtained with 1- D and 3- D conductivity models) of Sq is substantial at CHAMP altitude, comprising 50% of the total field. It is therefore necessary to consider induction in the oceans when modeling Sq variations for both ground- based and satellite data. Finally, we demonstrate that the anomalous behavior of the daily variations in Z at south Indian sites, namely, a large positive prenoon peak, can be explained by 3- D induction of the Sq variations, with no contribution from the EEJ. C1 ETH, Inst Geophys, CH-8093 Zurich, Switzerland. Natl Geophys Res Inst, Hyderabad 500007, Andhra Pradesh, India. Danish Natl Space Ctr, DK-2100 Copenhagen, Denmark. NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. RP Kuvshinov, A (reprint author), ETH, Inst Geophys, Schafmattsstr 30, CH-8093 Zurich, Switzerland. EM kuvshinov@erdw.ethz.ch RI Nair, Manoj/C-4813-2009; Olsen, Nils/H-1822-2011; Sabaka, Terence/D-5618-2012 OI Olsen, Nils/0000-0003-1132-6113; NR 45 TC 18 Z9 18 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 23 PY 2007 VL 112 IS B10 AR B10102 DI 10.1029/2007JB004955 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 225MW UT WOS:000250523000001 ER PT J AU Wang, DY Huo, WM AF Wang, Dunyou Huo, Winifred M. TI An eight-degree-of-freedom, time-dependent quantum dynamics study for the H-2+C2H reaction on a new modified potential energy surface SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RATE-CONSTANT MEASUREMENTS; ROTOR TARGET MODEL; DIMENSIONALITY CALCULATIONS; REDUCED DIMENSIONALITY; TEMPERATURE-DEPENDENCE; SCATTERING; C2H; PHOTOCHEMISTRY; ATMOSPHERE; ACETYLENE AB An eight-dimensional time-dependent quantum dynamics wave packet approach is performed for the study of the H-2+C2H -> H+C2H2 reaction system on a new modified potential energy surface (PES) [L.-P. Ju , Chem. Phys. Lett. 409, 249 (2005)]. This new potential energy surface is obtained by modifying Wang and Bowman's old PES [J. Chem. Phys. 101, 8646 (1994)] based on the new ab initio calculation. This new modified PES has a much lower transition state barrier height at 2.29 kcal/mol than Wang and Bowman's old PES at 4.3 kcal/mol. This study shows that the reactivity for this diatom-triatom reaction system is enhanced by vibrational excitations of H-2, whereas the vibrational excitations of C2H only have a small effect on the reactivity. Furthermore, the bending excitations of C2H, compared to the ground state reaction probability, hinder the reactivity. The comparison of the rate constant between this calculation and experimental results agrees with each other very well. This comparison indicates that the new modified PES corrects the large barrier height problem in Wang and Bowman's old PES. (C) American Institute of Physics [DOI: 10.1063/1.2974757] C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Wang, DY (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, MS IN K8-91 PO Box 999, Richland, WA 99352 USA. EM dunyou.wang@pnl.gov NR 57 TC 8 Z9 8 U1 1 U2 14 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 OCT 21 PY 2007 VL 127 IS 15 AR 154304 DI 10.1063/1.2794757 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 222KS UT WOS:000250295900022 PM 17949146 ER PT J AU Neudeck, PG Du, H Skowronski, M Spry, DJ Trunek, AJ AF Neudeck, P. G. Du, H. Skowronski, M. Spry, D. J. Trunek, A. J. TI Growth and characterization of 3C-SiC and 2H-AlN/GaN films and devices produced on step-free 4H-SiC mesa substrates SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Review ID FREE-SURFACE HETEROEPITAXY; EPITAXIAL-GROWTH; BREAKDOWN FIELD; PIN DIODES; DEFECTS; LAYERS; GAN; DISLOCATIONS; DEGRADATION; CANTILEVERS AB While previously published experimental results have shown that the step- free ( 0 0 0 1) 4H-SiC mesa growth surface uniquely enables radical improvement of 3C-SiC and 2H-AlN/ GaN heteroepitaxial film quality (> 100-fold reduction in extended defect densities), important aspects of the step-free mesa heterofilm growth processes and resulting electronic device benefits remain to be more fully elucidated. This paper reviews and updates recent ongoing studies of 3C -SiC and 2H -AlN/ GaN heteroepilayers grown on top of 4H -SiC mesas. For both 3C -SiC and AlN/ GaN films nucleated on 4H -SiC mesas rendered completely free of atomic-scale surface steps, TEM studies reveal that relaxation of heterofilm strain arising from in-plane film/ substrate lattice constant mismatch occurs in a remarkably benign manner that avoids formation of threading dislocations in the heteroepilayer. In particular, relaxation appears to occur via nucleation and inward lateral glide of near-interfacial dislocation half-loops from the mesa sidewalls. Preliminary studies of homojunction diodes implemented in 3C-SiC and AlN/ GaN heterolayers demonstrate improved electrical performance compared with much more defective heterofilms grown on neighbouring stepped 4H -SiC mesas. Recombination-enhanced dislocation motion known to degrade forward-biased 4H -SiC bipolar diodes has been completely absent from our initial studies of 3C -SiC diodes, including diodes implemented on defective 3C -SiC heterolayers grown on stepped 4H -SiC mesas. C1 NASA, Glenn Res Ctr, OAI, Cleveland, OH 44135 USA. Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Neudeck, PG (reprint author), NASA, Glenn Res Ctr, OAI, 21000 Brookpk Rd,MS 77-1, Cleveland, OH 44135 USA. EM Neudeck@nasa.gov; mareks@cmu.edu RI Skowronski, Marek/A-8934-2011 OI Skowronski, Marek/0000-0002-2087-0068 NR 44 TC 11 Z9 11 U1 2 U2 20 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD OCT 21 PY 2007 VL 40 IS 20 BP 6139 EP 6149 DI 10.1088/0022-3727/40/20/S01 PG 11 WC Physics, Applied SC Physics GA 217YT UT WOS:000249983900002 ER PT J AU Sidick, E AF Sidick, Erkin TI Requirements on optical density and phase dispersion of imperfect band-limited occulting masks in a broadband coronagraph SO APPLIED OPTICS LA English DT Article ID PLANET-FINDER CORONAGRAPH AB We investigate the effects of the parasitic phase of imperfect band-limited occulting masks on the broadband contrast performance of a high-contrast imaging system through modeling and simulations. We also examine the effects of the phase and the optical-density dispersions of occulting masks whose parasitic phase has been compensated at the center wavelength but is nonzero at other wavelengths. Two types of occulting masks are considered: gray-scale masks such as those made on a high-energy beam-sensitive glass, and recently proposed spatially profiled metal masks, both having 1D Smc(2) (linear-Sinc(2)) amplitude transmission coefficient (Sinc(4) intensity transmittance) profiles. We determine the conditions for obtaining 1 X 10(-9) and 1 X 10(-10) contrast values with a light centered at a 785 nm wavelength and having a 10% bandwidth in a coronagraphic telescope having ideal optical surfaces but imperfect band-limited image-plane occulting masks. (c) 2007 Optical Society of America C1 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. EM erkin.sidick@jpl.nasa.gov NR 12 TC 2 Z9 2 U1 0 U2 0 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 OCT 20 PY 2007 VL 46 IS 30 BP 7485 EP 7493 DI 10.1364/AO.46.007485 PG 9 WC Optics SC Optics GA 232VC UT WOS:000251047200019 PM 17952186 ER PT J AU Ogle, P Antonucci, R Appleton, PN Whysong, D AF Ogle, Patrick Antonucci, Robert Appleton, P. N. Whysong, David TI Shocked molecular hydrogen in the 3C 326 radio galaxy system SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : jets; infrared : galaxies ID SPITZER-SPACE-TELESCOPE; ACTIVE GALACTIC NUCLEI; STAR-FORMATION; INFRARED SPECTROGRAPH; SEYFERT-GALAXIES; STEPHANS-QUINTET; EMISSION; H-2; STARBURST; NGC-6240 AB The Spitzer spectrum of the giant FR II radio galaxy 3C 326 is dominated by very strong molecular hydrogen emission lines on a faint IR continuum. The H-2 emission originates in the northern component of a double-galaxy system associated with 3C 326. The integrated luminosity in H-2 pure rotational lines is 8.0 x 10(41) erg s(-1), which corresponds to 17% of the 8-70 mu m luminosity of the galaxy. A wide range of temperatures (125-1000 K) is measured from the H-2 0-0 S(0)-S(7) transitions, leading to a warm H-2 mass of 1.1 x 10(9) M circle dot. Low-excitation ionic forbidden emission lines are consistent with an optical LINER classification for the active nucleus, which is not luminous enough to power the observed H2 emission. The H2 could be shock heated by the radio jets, but there is no direct indication of this. More likely, the H-2 is shock heated in a tidal accretion flow induced by interaction with the southern companion galaxy. The latter scenario is supported by an irregular morphology, a tidal bridge, and a possible tidal tail imaged with IRAC at 3-9 mu m. Unlike ultraluminous infrared galaxies, which in some cases exhibit H-2 line luminosities of comparable strength, 3C 326 shows little star formation activity (similar to 0.1 M circle dot yr(-1)). This may represent an important stage in galaxy evolution. Starburst activity and efficient accretion onto the central supermassive black hole may be delayed until the shock-heated H-2 can kinematically settle and cool. C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. CALTECH, NASA, Herschel Sci Ctr, Pasadena, CA 91125 USA. Natl Radio Astron Observ, Array Operat Ctr, Socorro, NM 87801 USA. RP Ogle, P (reprint author), CALTECH, Spitzer Sci Ctr, Mail Code 220-6, Pasadena, CA 91125 USA. EM ogle@ipac.caltech.edu OI Appleton, Philip/0000-0002-7607-8766 NR 48 TC 53 Z9 53 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 OCT 20 PY 2007 VL 668 IS 2 BP 699 EP 707 DI 10.1086/521334 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800006 ER PT J AU Kraemer, SB Bottorff, MC Crenshaw, DM AF Kraemer, S. B. Bottorff, M. C. Crenshaw, D. M. TI On the effects of dissipative turbulence on the narrow emission-line ratios in Seyfert galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : Seyfert; line : formation; turbulence ID TELESCOPE IMAGING SPECTROGRAPH; ACTIVE GALACTIC NUCLEI; INTRINSIC ABSORPTION-LINES; HUBBLE-SPACE-TELESCOPE; LONG-SLIT SPECTROSCOPY; PHYSICAL CONDITIONS; NGC 4151; RESOLVED SPECTROSCOPY; ECHELLE OBSERVATIONS; IONIZED-GAS AB We present a photoionization model study of the effects of microturbulence and dissipative heating on emission lines for number and column densities, elemental abundances, and ionizations typical for the narrow emission line regions ( NLRs) of Seyfert galaxies. Earlier studies of NLR spectra generally found good agreement between the observations and the model predictions for most strong emission lines, such as [O III] lambda 5007, [O II] lambda 3727, [NII] lambda 6583, [Ne III] lambda 3869, and the H and He recombination lines. Nevertheless, the strengths of lines from species with ionization potentials greater than that of He+ (54.4 eV), e.g., N+4 and Ne+4, were often underpredicted. Among the explanations suggested for these discrepancies were (selectively) enhanced elemental abundances and contributions from shock-heated gas. Interestingly, the NLR lines have widths of several 100 km s(-1), well in excess of the thermal broadening. If this is due to microturbulence, and the turbulence dissipates within the emission-line gas, the gas can be heated in excess of that due to photoionization. We show that the combined effects of turbulence and dissipative heating can strongly enhance N v lambda 1240 ( relative to He II lambda 1640), while the heating alone can boost the strength of [Ne v] lambda 3426. We suggest that this effect is present in the NLR, particularly within similar to 100 pc of the central engine. Finally, since microturbulence would make clouds robust against instabilities generated during acceleration, it is not likely to be a coincidence that the radially outflowing emission-line gas is turbulent. C1 Catholic Univ Amer, Dept Phys, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. Southwestern Univ, Dept Phys, Georgetown, TX 78626 USA. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. RP Kraemer, SB (reprint author), Catholic Univ Amer, Dept Phys, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. EM kraemer@yancey.gsfc.nasa.gov NR 67 TC 5 Z9 5 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 OCT 20 PY 2007 VL 668 IS 2 BP 730 EP 737 DI 10.1086/521272 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800009 ER PT J AU Bonamente, M Nevalainen, J Lieu, R AF Bonamente, Massimiliano Nevalainen, Jukka Lieu, Richard TI Soft and hard X-ray excess emission in abell 3112 observed with Chandra SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (Abell 3112); X-rays : galaxies : clusters ID EXTREME-ULTRAVIOLET EMISSION; HOT INTERGALACTIC MEDIUM; FLUX-LIMITED SAMPLE; XMM-NEWTON; GALAXY CLUSTERS; COMA CLUSTER; NONTHERMAL NATURE; COOLING FLOWS; SHOCK FRONTS; COSMIC-RAYS AB Chandra ACIS-S observations of the galaxy cluster Abell 3112 feature the presence of an excess of X-ray emission above the contribution from the diffuse hot gas, which can be equally well modeled with an additional nonthermal power-law model or with a low-temperature thermal model of low metal abundance. We show that the excess emission cannot be due to uncertainties in the background subtraction or in the Galactic H I column density. Calibration uncertainties in the ACIS detector that may affect our results are addressed by comparing the Chandra data to XMM-Newton MOS and PN spectra. While differences between the three instruments remain, all detect the excess in similar amounts, providing evidence against an instrumental nature of the excess. Given the presence of nonthermal radio emission near the center of Abell 3112, we argue that the excess X-ray emission is of nonthermal nature and distributed throughout the entire X-ray bandpass, from soft to hard X-rays. The excess can be explained with the presence of a population of relativistic electrons with similar to 7% of the cluster's gas pressure. We also discuss a possible thermal nature of the excess and examine the problems associated with such interpretation. C1 Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. Univ Helsinki, Helsinki, Finland. RP Bonamente, M (reprint author), Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NR 44 TC 12 Z9 12 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 OCT 20 PY 2007 VL 668 IS 2 BP 796 EP 805 DI 10.1086/521381 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800014 ER PT J AU Ryan, RE Hathi, NP Cohen, SH Malhotra, S Rhoads, J Windhorst, RA Budavari, T Pirzkal, N Xu, C Panagia, N Moustakas, LA Alighieri, SDS Yan, H AF Ryan, R. E. Hathi, N. P. Cohen, S. H. Malhotra, S. Rhoads, J. Windhorst, R. A. Budavari, T. Pirzkal, N. Xu, C. Panagia, N. Moustakas, L. A. Alighieri, S. Di Serego Yan, H. TI The galaxy luminosity function at z similar or equal to 1 in the HUDF: Probing the dwarf population SO ASTROPHYSICAL JOURNAL LA English DT Article DE catalogs; galaxies : high-redshift; surveys ID ULTRA DEEP FIELD; GOODS-SOUTH FIELD; HUBBLE-SPACE-TELESCOPE; LYMAN-BREAK GALAXIES; PHOTOMETRIC REDSHIFTS; DATA REDUCTION; EVOLUTION; DENSITY; CATALOG; Z-SIMILAR-TO-1 AB We present a catalog of spectrophotometric redshifts for 1308 galaxies from the Grism ACS Program for Extragalactic Science (GRAPES) observations with the Hubble Space Telescope. These low-resolution spectra between 6000 angstrom and 9500 angstrom are supplemented with U, J, H, and K-s data from various facilities, resulting in redshifts computed with similar to 40 spectral bins per galaxy. For 75 galaxies in the range 0.5 < z < 1.5 with spectroscopic redshifts, the standard deviation in the fractional error in 1 + z is 0.037. With this catalog, we compute the B-band luminosity function in this redshift range from 72 galaxies. Due to the depth of the GRAPES survey, we are able to accurately constrain the faint-end slope by going to MB similar or equal to -18 mag at z = 1.0 +/- 0.2, nearly 2 mag fainter than previous studies. The faint-end slope is alpha = -1.32 +/- 0.07. When compared to numerous published values at various redshifts, we find strong evidence for a steepening of the faint-end slope with redshift, which is expected in the hierarchical formation scenario of galaxies. C1 Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA. Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Shanghai Inst Tech Phys, Shanghai 200083, Peoples R China. Space Telescope Sci Inst, Baltimore, MD 21218 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. INAF, Osservatorio Astrofis Arcetri, I-50125 Florence, Italy. CALTECH, Pasadena, CA 91125 USA. RP Ryan, RE (reprint author), Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA. EM russell.ryanjr@asu.edu RI di Serego Alighieri, Sperello/E-4067-2010; Hathi, Nimish/J-7092-2014 OI di Serego Alighieri, Sperello/0000-0001-8769-2692; Hathi, Nimish/0000-0001-6145-5090 NR 52 TC 36 Z9 36 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 OCT 20 PY 2007 VL 668 IS 2 BP 839 EP 845 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800018 ER PT J AU Baker, JG Boggs, WD Centrella, J Kelly, BJ McWilliams, ST Miller, MC van Meter, JR AF Baker, John G. Boggs, William D. Centrella, Joan Kelly, Bernard J. McWilliams, Sean T. Miller, M. Coleman van Meter, James R. TI Modeling kicks from the merger of nonprecessing black hole binaries SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; galaxies : nuclei; gravitational waves; relativity ID GRAVITATIONAL-RADIATION RECOIL; ADAPTIVE MESH REFINEMENT; NUMERICAL RELATIVITY; COMPACT OBJECTS; GALACTIC NUCLEI; STAR-CLUSTERS; SPIN; GROWTH; SYSTEMS; ORDER AB Several groups have recently computed the gravitational radiation recoil produced by the merger of two spinning black holes. The results suggest that spin can be the dominant contributor to the kick, with reported recoil speeds of hundreds to even thousands of kilometers per second. The parameter space of spin kicks is large, however, and it is ultimately desirable to have a simple formula that gives the approximate magnitude of the kick given a mass ratio, spin magnitudes, and spin orientations. As a step toward this goal, we perform a systematic study of the recoil speeds from mergers of black holes with mass ratio q = m(1)/m(2) = 2/ 3 and dimensionless spin parameters of a(1)/m(1) and a(2)/m(2) equal to 0 or 0.2, with directions aligned or antialigned with the orbital angular momentum. We also run an equal-mass a(1)/m(1) = -a(2)/m(2) = 0.2 case, and find good agreement with previous results. We find that, for currently reported kicks from aligned or antialigned spins, a simple kick formula inspired by post-Newtonian analyses can reproduce the numerical results to better than similar to 10%. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Lab Gravitat Astrophys, Greenbelt, MD 20771 USA. RP Baker, JG (reprint author), Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RI van meter, james/E-7893-2011; Kelly, Bernard/G-7371-2011; OI Kelly, Bernard/0000-0002-3326-4454 NR 74 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 OCT 20 PY 2007 VL 668 IS 2 BP 1140 EP 1144 DI 10.1086/521330 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800042 ER PT J AU Moro-Martin, A Malhotra, R Carpenter, JM Hillenbrand, LA Wolf, S Meyer, MR Hollenbach, D Najita, J Henning, T AF Moro-Martin, Amaya Malhotra, Renu Carpenter, John M. Hillenbrand, Lynne A. Wolf, Sebastian Meyer, Michael R. Hollenbach, David Najita, Joan Henning, Thomas TI The dust, planetesimals, and planets of HD 38529 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; Kuiper Belt; planetary systems; stars : individual (HD 38529) ID KUIPER-BELT DUST; SOLAR-SYSTEM; DEBRIS DISKS; BETA-PICTORIS; CIRCUMSTELLAR DISK; HR 4796A; SIZE DISTRIBUTIONS; PREDICTING PLANETS; EXTRASOLAR PLANETS; INFRARED-EMISSION AB HD 38529 is a post-main-sequence G8 III/IV star (3.5 Gyr old) with a planetary system consisting of at least two planets having M sin i of 0.8 and 12.2 M-Jup, semimajor axes of 0.13 and 3.74 AU, and eccentricities of 0.25 and 0.35, respectively. Spitzer observations show that HD 38529 has an excess emission above the stellar photosphere, with a signal-to-noise ratio (S/N) at 70 mu m of 4.7, a small excess at 33 mu m (S/N 2: 6), and no excess < 30 mu m. We discuss the distribution of the potential dust-producing planetesimals from the study of the dynamical perturbations of the two known planets, considering in particular the effect of secular resonances. We identify three dynamically stable niches at 0.4-0.8, 20-50, and beyond 60 AU. We model the spectral energy distribution (SED) of HD 38529 to find out which of these niches show signs of harboring dust-producing planetesimals. The secular analysis, together with the SED modeling results, suggest that the planetesimals responsible for most of the dust emission are likely located within 20-50 AU, a configuration that resembles that of the Jovian planets +Kuiper Belt in our solar system. Finally, we place upper limits (8 x 10(-6) lunar masses of 10 mu m particles) to the amount of dust that could be located in the dynamically stable region that exists between the two planets (0.25-0.75 AU). C1 Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Natl Opt Astron Observ, Tucson, AZ 85721 USA. RP Moro-Martin, A (reprint author), Princeton Univ, Dept Astrophys Sci, Peyton Hall,Ivy Lane, Princeton, NJ 08544 USA. EM amaya@astro.princeton.edu OI Malhotra, Renu/0000-0002-1226-3305 NR 53 TC 25 Z9 25 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 OCT 20 PY 2007 VL 668 IS 2 BP 1165 EP 1173 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800046 ER PT J AU France, K Roberge, A Lupu, RE Redfield, S Feldman, PD AF France, Kevin Roberge, Aki Lupu, Roxana E. Redfield, Seth Feldman, Paul D. TI A low-mass H-2 component to the AU Microscopii circumstellar disk SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary systems : protoplanetary disks; stars : individual (AU Microscopii, HD 197481); ultraviolet : stars ID MOLECULAR-HYDROGEN EMISSION; MAIN-SEQUENCE STARS; SPECTROSCOPIC-EXPLORER OBSERVATIONS; DEBRIS DISKS; PLANETARY SYSTEMS; SPACE-TELESCOPE; T-TAURI; ULTRAVIOLET-SPECTRUM; TRANSITION REGION; GAS TEMPERATURE AB We present a determination of the molecular gas mass in the AU Microscopii circumstellar disk. Direct detection of a gas component to the AU Mic disk has proven elusive, with upper limits derived from ultraviolet absorption line and submillimeter CO emission studies. Fluorescent emission lines of H-2, pumped by the O VI lambda 1032 resonance line through the C-X (1-1) Q(3) lambda 1031.87 angstrom transition, are detected by the Far Ultraviolet Spectroscopic Explorer. These lines are used to derive the H2 column density associated with the AU Mic system. The derived column density is in the range N(H-2) 1.9 x 10(17) to 2.8 x 10(15) cm(-2), roughly 2 orders of magnitude lower than the upper limit inferred from absorption line studies. This range of column densities reflects the range of H2 excitation temperature consistent with the observations, T(H2) 800-2000 K, derived from the presence of emission lines excited by O vi in the absence of those excited by Ly alpha. Within the observational uncertainties, the data are consistent with the H-2 gas residing in the disk. The inferred N(H-2) ran(g)e corresponds to H-2-to-dust ratios of less than or similar to 1/30:1 and a total M(H-2) 4.0 x 10(-4) to 5.8 x 10(-6) M-circle plus. We use these results to predict the intensity of the associated rovibrational emission lines of H-2 at infrared wavelengths covered by ground-based instruments, HST NICMOS, and the Spitzer IRS. C1 Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. RP France, K (reprint author), Univ Toronto, Canadian Inst Theoret Astrophys, 60 St George St, Toronto, ON M5S 3H8, Canada. EM france@cita.utoronto.ca; akir@milkyway.gsfc.nasa.gov; roxana@pha.jhu.edu; sredfield@astro.as.utexas.edu; pdf@pha.jhu.edu RI Roberge, Aki/D-2782-2012; Lupu, Roxana/P-9060-2014 OI Roberge, Aki/0000-0002-2989-3725; Lupu, Roxana/0000-0003-3444-5908 NR 68 TC 17 Z9 17 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 OCT 20 PY 2007 VL 668 IS 2 BP 1174 EP 1181 DI 10.1086/521348 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800047 ER PT J AU Lazio, TJW Farrell, WM AF Lazio, T. Joseph W. Farrell, W. M. TI Magnetospheric emissions from the planet orbiting tau Bootis: A multiepoch search SO ASTROPHYSICAL JOURNAL LA English DT Article DE planetary systems; radio continuum : stars ID RADIO EMISSIONS; SKY SURVEY; EXTRASOLAR PLANETS; GIANT PLANETS; STARS; FIELDS AB All of the solar system gas giants produce electron cyclotron masers driven by the solar wind impinging on their magnetospheres. Extrapolating to the planet orbiting tau Boo, various authors have predicted that it may be within the detection limits of the 4 m wavelength (74 MHz) system on the Very Large Array. This paper reports three epochs of observations of tau Boo. In no epoch do we detect the planet; various means of determining the upper limit to the emission yield single-epoch limits ranging from 135 to 300 mJy. We develop a likelihood method for multiepoch observations and use it to constrain various radiation properties of the planet. If we assume that the planet does radiate at our observation wavelength, its typical luminosity must be less than about 1016 W, unless its radiation is highly beamed into a solid angle of Omega << 1 sr. While this value is within the range of luminosities predicted by various authors for this planet, it is lower than recent estimates that attempt to take into account the stellar wind of tau Boo using the known properties of the star itself. Electron cyclotron maser emission from solar system planets is beamed, but with characteristic solid angles of approximately 1 sr illuminated. Future long-wavelength instruments (e. g., the Long Wavelength Array and the Low Frequency Array) must be able to make typical flux density measurements of approximately 25 mJy on short timescales (approximate to 15 minutes) in order to improve these constraints significantly. C1 Naval Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lazio, TJW (reprint author), Naval Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. EM Joseph.Lazio@nrl.navy.mil; william.m.farrell@gsfc.nasa.gov RI Farrell, William/I-4865-2013 NR 27 TC 30 Z9 30 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 OCT 20 PY 2007 VL 668 IS 2 BP 1182 EP 1188 DI 10.1086/519730 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800048 ER PT J AU Moore, RL Sterling, AC Suess, ST AF Moore, Ronald L. Sterling, Alphonse C. Suess, Steven T. TI The width of a solar coronal mass ejection and the source of the driving magnetic explosion: A test of the standard scenario for CME production SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : coronal mass ejections (CMEs); Sun : flares; Sun : magnetic fields ID ACTIVE REGIONS; FLARE MYTH; FILAMENT ERUPTIONS; ENERGY-RELEASE; RECONNECTION; MODEL; PROMINENCES; FIELD AB We show that the strength (B(Flare)) of the magnetic field in the area covered by the flare arcade following a CME-producing ejective solar eruption can be estimated from the final angular width (Final theta(CME)) of the CME in the outer corona and the final angular width (theta(Flare)) of the flare arcade: B(Flare) approximate to 1.4[(Final theta(CME))/theta(FLARE)](2) G. We assume (1) the flux-rope plasmoid ejected from the flare site becomes the interior of the CME plasmoid; (2) in the outer corona (R > 2 R(circle dot)) the CME is roughly a "spherical plasmoid with legs'' shaped like a lightbulb; and (3) beyond some height in or below the outer corona the CME plasmoid is in lateral pressure balance with the surrounding magnetic field. The strength of the nearly radial magnetic field in the outer corona is estimated from the radial component of the interplanetary magnetic field measured by Ulysses. We apply this model to three well-observed CMEs that exploded from flare regions of extremely different size and magnetic setting. One of these CMEs was an over-and-out CME, that is, in the outer corona the CME was laterally far offset from the flare-marked source of the driving magnetic explosion. In each event, the estimated source-region field strength is appropriate for the magnetic setting of the flare. This agreement (1) indicates that CMEs are propelled by the magnetic field of the CME plasmoid pushing against the surrounding magnetic field; (2) supports the magnetic-arch-blowout scenario for over-and-out CMEs; and (3) shows that a CME's final angular width in the outer corona can be estimated from the amount of magnetic flux covered by the sourceregion flare arcade. C1 NASA, George C Marshall Space Flight Ctr, Space Sci Off, Huntsville, AL 35812 USA. RP Moore, RL (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Off, VP62, Huntsville, AL 35812 USA. NR 58 TC 19 Z9 19 U1 0 U2 4 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 OCT 20 PY 2007 VL 668 IS 2 BP 1221 EP 1231 DI 10.1086/521215 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800052 ER PT J AU Burlaga, LF Ness, NF Acuna, MH AF Burlaga, L. F. Ness, N. F. Acuna, M. H. TI Magnetic fields in the heliosheath and distant heliosphere: Voyager 1 and 2 observations during 2005 and 2006 SO ASTROPHYSICAL JOURNAL LA English DT Article DE magnetic fields; MHD; solar wind; turbulence ID LOCAL INTERSTELLAR-MEDIUM; WIND TERMINATION SHOCK; SOLAR-WIND; CURRENT SHEET; SECTOR STRUCTURE; FLOW DOWNSTREAM; ULYSSES; HELIOPAUSE; PLASMA; SYSTEM AB This paper examines the variability of daily averages of the magnetic field strength B in the heliosheath and in the distant solar wind measured by Voyager 1 (V1) and Voyager 2 (V2), respectively, from 2005.0 to 2006.9. In the heliosheath, a spatial gradient of (0.0023 +/- 0.0011) nT AU(-1) is observed, which constrains models of the inner heliosheath. This gradent is small compared to the expected average gradient of B across the entire heliosheath. In the heliosheath the profile of B is generally filamentary with numerous jumps, but a large-amplitude sine wave with a period of approximate to 200 days was observed by V1 at the end of the interval. The fluctuations of daily averages of B observed by V1 and V2 have a Gaussian distribution and lognormal distribution, respectively. The autocorrelation of B(t) from day of year (DOY) 1-512 was an exponential function with an e-folding time of approximate to 3.7 +/- 0.5 days for V1 and 2.5 +/- 0.3 days for V2. On scales from 1-4 days, the autocorrelation function was a power law with exponent alpha =-0.440 +/- 0.031 for V1 and alpha =-0.497 +/- 0.002 for V2. The distribution of differences of successive daily averages of B for both V1 and V2 is the Tsallis distribution of nonextensive statistical mechanics with the nonextensivity parameter q = 1.55 +/- 0.05. V2 (at approximate to S26 degrees) observed both positive and negative magnetic polarities throughout the interval from 2005.0 to 2006.9. There is evidence that V1 (at N34 degrees) might be entering a region of negative magnetic polarity as the latitudinal extent of the heliospheric current sheet decreases during the declining phase of solar cycle 23. C1 NASA, Goddard Space Flight Ctr, Geophys Phys Lab, Greenbelt, MD 20771 USA. Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Planetary Magnetospheres Lab, Greenbelt, MD 20771 USA. RP Burlaga, LF (reprint author), NASA, Goddard Space Flight Ctr, Geophys Phys Lab, Code 673, Greenbelt, MD 20771 USA. EM leonard.f.burlaga@nasa.gov; nfnudel@yahoo.com; mario.h.acuna@nasa.gov NR 65 TC 32 Z9 32 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 OCT 20 PY 2007 VL 668 IS 2 BP 1246 EP 1258 DI 10.1086/521349 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KF UT WOS:000250082800054 ER PT J AU Krimm, HA Markwardt, CB Deloye, CJ Romano, P Chakrabarty, D Campana, S Cummings, JR Galloway, DK Gehrels, N Hartman, JM Kaaret, P Morgan, EH Tueller, J AF Krimm, H. A. Markwardt, C. B. Deloye, C. J. Romano, P. Chakrabarty, D. Campana, S. Cummings, J. R. Galloway, D. K. Gehrels, N. Hartman, J. M. Kaaret, P. Morgan, E. H. Tueller, J. TI Discovery of the accretion-powered millisecond pulsar SWIFT J1756.9-2508 with a low-mass companion SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; pulsars : general; stars : neutron; white dwarfs; X-rays : binaries ID SAX J1808.4-3658; BINARY-SYSTEMS; RADIO PULSARS; OUTBURST AB We report on the discovery by the Swift Gamma- Ray Burst Explorer of the eighth known transient accretion- powered millisecond pulsar, SWIFT J1756.9 - 2508, as part of routine observations with the Swift Burst Alert Telescope hard X- ray transient monitor. The pulsar was subsequently observed by both the X- Ray Telescope on Swift and the Rossi X- Ray Timing Explorer Proportional Counter Array. It has a spin frequency of 182 Hz ( 5.5 ms) and an orbital period of 54.7 minutes. The minimum companion mass is between 0.0067 and, depending on the mass of the 0.0086 M-circle dot, neutron star, and the upper limit on the mass is 0.030 M-circle dot ( 95% confidence level). Such a low mass is inconsistent 0.030 M, with brown dwarf models, and comparison with white dwarf models suggests that the companion is a He- dominated donor whose thermal cooling has been at least modestly slowed by irradiation from the accretion flux. No X- ray bursts, dips, eclipses, or quasi- periodic oscillations were detected. The current outburst lasted approximate to 13 days, and no earlier outbursts were found in archival data. C1 CRESST, Greenbelt, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. INAF Osservatorio Astron Brera, Merate, LC, Italy. Univ Milan, Milan, Italy. MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. Univ Maryland, Joint Res Ctr Astrophys, Baltimore, MD 21201 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Krimm, HA (reprint author), CRESST, Greenbelt, MD USA. EM krimm@milkyway.gsfc.nasa.gov RI Gehrels, Neil/D-2971-2012; Tueller, Jack/D-5334-2012 NR 28 TC 40 Z9 40 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 OCT 20 PY 2007 VL 668 IS 2 BP L147 EP L150 DI 10.1086/522959 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KH UT WOS:000250083000014 ER PT J AU Milam, SN Apponi, AJ Woolf, NJ Ziurys, LM AF Milam, S. N. Apponi, A. J. Woolf, N. J. Ziurys, L. M. TI Oxygen-rich mass loss with a pinch of salt: NaCl in the circumstellar gas of IK Tauri and VY Canis Majoris SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrochemistry; radio lines : stars; stars : chemically peculiar; stars : individual (VY Canis Majoris IK Tauri IRC+10216) ID MOLECULAR ABUNDANCES; STARS; EMISSION; ENVELOPE; IRC; IRC+10216; WINDS; DUST; CO AB The NaCl molecule has been observed in the circumstellar envelopes of VY Canis Majoris ( VY CMa) and IK Tauri ( IK Tau) - the first identifications of a metal refractory in oxygen- rich shells of evolved stars. Five rotational transitions of NaCl at 1 and 2 mm were detected toward VY CMa and three 1 mm lines were observed toward IK Tau, using the telescopes of the Arizona Radio Observatory. In both objects, the line widths of the NaCl profiles were extremely narrow relative to those of other molecules, indicating that sodium chloride has not reached the terminal outflow velocity in either star, likely a result of early condensation onto grains. Modeling the observed spectra suggests abundances, relative to H-2, of f similar to 5x10(-9) in VY CMa and f similar to 4x10(-9) in IK Tau, with source sizes of 0.5 '' and 0.3 '', respectively. The extent of these sources is consistent with the size of the dust acceleration zones in both stars. NaCl therefore appears to be at least as abundant in O-rich shells as compared to C-rich envelopes, where f similar to(0.2-2)x10(-9) although it appears to condense out earlier in the O-rich case. Chemical equilibrium calculations indicate that NaCl is the major carrier of sodium at T similar to 1100 K for oxygen- rich stars, with predicted fractional abundances in good agreement with the observations. These measurements suggest that crystalline salt may be an important condensate for sodium in both C- and O- rich circumstellar shells. C1 NASA, Astrobiol Inst, Dept Astron, Dept Chem, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Milam, SN (reprint author), NASA, Astrobiol Inst, Dept Astron, Dept Chem, 933 N Cherry Ave, Tucson, AZ 85721 USA. EM stemil@as.arizona.edu; aapponi@as.arizona.edu; nwoolf@as.arizona.edu; lziurys@as.arizona.edu RI Milam, Stefanie/D-1092-2012 OI Milam, Stefanie/0000-0001-7694-4129 NR 27 TC 18 Z9 18 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 OCT 20 PY 2007 VL 668 IS 2 BP L131 EP L134 DI 10.1086/522928 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KH UT WOS:000250083000010 ER PT J AU Reynolds, SP Borkowski, KJ Hwang, U Hughes, JP Badenes, C Laming, JM Blondin, JM AF Reynolds, Stephen P. Borkowski, Kazimierz J. Hwang, Una Hughes, John P. Badenes, Carles Laming, J. M. Blondin, J. M. TI A deep Chandra observation of Kepler's supernova remnant: A type IA event with circumstellar interaction SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (G4.5+6.8 (SN 1604)); supernova remnants; supernovae : general; X-rays : ISM ID XMM-NEWTON OBSERVATION; STAR; PROGENITORS; CONSTRAINTS; ENVELOPE; MODELS; MASS AB We present initial results of a 750 ks Chandra observation of the remnant of Kepler's supernova of AD 1604. The strength and prominence of iron emission, together with the absence of O-rich ejecta, demonstrate that Kepler resulted from a thermonuclear supernova, even though evidence for circumstellar interaction is also strong. We have analyzed spectra of over 100 small regions, and find that they fall into three classes. ( 1) The vast majority show Fe L emission between 0.7 and 1 keV and Si and S K alpha emission; we associate these with shocked ejecta. A few of these are found at or beyond the mean blast wave radius. (2) A very few regions show solar O/Fe abundance ratios; these we associate with shocked circumstellar medium ( CSM). Otherwise O is scarce. ( 3) A few regions are dominated by continuum, probably synchrotron radiation. Finally, we find no central point source, with a limit similar to 100 times fainter than the central object in Cas A. The evidence that the blast wave is interacting with CSM may indicate a Ia explosion in a more massive progenitor. C1 N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. USN, Res Lab, Washington, DC 20375 USA. RP Reynolds, SP (reprint author), N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. EM stephen_reynolds@ncsu.edu NR 40 TC 57 Z9 58 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 OCT 20 PY 2007 VL 668 IS 2 BP L135 EP L138 DI 10.1086/522830 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KH UT WOS:000250083000011 ER PT J AU Urata, Y Yamazaki, R Sakamoto, T Huang, KY Zheng, WK Sato, G Aoki, T Deng, JS Ioka, K Ip, W Kawabata, KS Lee, YH Xin, LP Mito, H Miyata, T Nakada, Y Ohsugi, T Qiu, YL Soyano, T Tarusawa, K Tashiro, M Uemura, M Wei, JY Yamashita, T AF Urata, Yuji Yamazaki, Ryo Sakamoto, Takanori Huang, Kuiyun Zheng, Weikang Sato, Goro Aoki, Tsutomu Deng, Jinsong Ioka, Kunihito Ip, WingHuen Kawabata, Koji S. Lee, YiHsi Xin, Liping Mito, Hiroyuki Miyata, Takashi Nakada, Yoshikazu Ohsugi, Takashi Qiu, Yulei Soyano, Takao Tarusawa, Kenichi Tashiro, Makoto Uemura, Makoto Wei, Jianyan Yamashita, Takuya TI Testing the external-shock model of gamma-ray bursts using the late-time simultaneous optical and X-ray afterglows SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; gamma rays : observations ID FOLLOW-UP OBSERVATIONS; SWIFT XRT DATA; LIGHT-CURVE; THEORETICAL IMPLICATIONS; ENERGY INJECTION; PROMPT EMISSION; FIREBALL MODEL; SHALLOW DECAY; GRB 050525A; JET BREAK AB We study the "normal" decay phase of the X- ray afterglows of gamma- ray bursts ( GRBs), which follows the shallow decay phase, using the events simultaneously observed in the R band. The classical external- shock model - in which neither the delayed energy injection nor time dependency of shock microphysics is considered shows that the decay indices of the X- ray and R- band light curves, alpha(x) and alpha(o), obey a certain relation, and that in particular, alpha(o) - alpha(x) should be larger than -1/4 unless the ambient density increases with the distance from the central engine. For our selected 14 samples, we have found that four events violate the limit at more than the 3 sigma level, so that a fraction of events are outliers of the classical external-shock model at the "normal" decay phase. C1 Saitama Univ, Dept Phys, Shimo Okubo, Saitama 3388570, Japan. Hiroshima Univ, Dept Phys, Hiroshima 7398526, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Acad Sinica, Inst Astron & Astrophys, Taipei 106, Taiwan. Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China. Univ Tokyo, Inst Astron, Kiso Observ, Nagano 3970101, Japan. Kyoto Univ, Dept Phys, Sakyo Ku, Kyoto 6068602, Japan. Natl Cent Univ, Inst Astron, Chungli 32054, Taiwan. Hiroshima Univ, Ctr Astrophys Sci, Hiroshima 7398536, Japan. RP Urata, Y (reprint author), Saitama Univ, Dept Phys, Shimo Okubo, Saitama 3388570, Japan. EM urata@heal.phy.saitama-u.ac.jp; ryo@theo.phys.sci.hiroshima-u.ac.jp RI Tashiro, Makoto/J-4562-2012 NR 56 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 EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2007 VL 668 IS 2 BP L95 EP L98 DI 10.1086/522930 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KH UT WOS:000250083000001 ER PT J AU Velusamy, T Langer, WD Marsh, KA AF Velusamy, T. Langer, William D. Marsh, Kenneth. A. TI Highly collimated jets and wide-angle outflows in HH 46/47: New evidence from SPITZER infrared images SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : Herbig-Haro objects; ISM : individual (HH 46/47); ISM : jets and outflows; stars : formation ID SPACE-TELESCOPE; MASS PROTOSTARS; HH 46/47; MODELS; SYSTEM; FLOW AB We present new details of the structure and morphology of the jets and outflows in HH 46/ 47 as seen in Spitzer infrared images from IRAC and MIPS, reprocessed using the " HiRes" deconvolution technique. HiRes improves the visualization of spatial morphology by enhancing resolution ( to subarcsecond levels in IRAC bands) and removing the contaminating side lobes from bright sources. In addition to sharper views of previously reported bow shocks, we have detected ( 1) the sharply delineated cavity walls of the wide- angle biconical outflow, seen in scattered light on both sides of the protostar, ( 2) several very narrow jet features at distances similar to 400 AU to similar to 0.1 pc from the star, and ( 3) compact emissions at MIPS 24 mm coincident with the jet heads, tracing the hottest atomic/ ionic gas in the bow shocks. Together the IRAC and MIPS images provide a more complete picture of the bow shocks, tracing both the molecular and atomic/ ionic gases, respectively. The narrow width and alignment of all jet- related features indicate a high degree of jet collimation and low divergence ( width of similar to 400 AU increasing by only a factor of 2.3 over 0.2 pc). The morphology of this jet, bow shocks, wide- angle outflows, and the fact that the jet is nonprecessing and episodic, constrain the mechanisms for producing the jet's entrained molecular gas, and origins of the fast jet, and slower wide- angle outflow. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, IPAC, Pasadena, CA 91125 USA. RP Velusamy, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM velusamy@jpl.nasa.gov NR 25 TC 43 Z9 43 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 OCT 20 PY 2007 VL 668 IS 2 BP L159 EP L162 DI 10.1086/522929 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219KH UT WOS:000250083000017 ER PT J AU Fang, HL Liang, SL Kim, HY Townshend, JR Schaaf, CL Strahler, AH Dickinson, RE AF Fang, Hongliang Liang, Shunlin Kim, Hye-Yun Townshend, John R. Schaaf, Crystal L. Strahler, Alan H. Dickinson, Robert E. TI Developing a spatially continuous 1 km surface albedo data set over North America from Terra MODIS products SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LEAF-AREA INDEX; ARABIAN PENINSULA; TIME-SERIES; MODEL; REFLECTANCE; ENVIRONMENT; RETRIEVALS; VALIDATION; BROADLEAF; DYNAMICS AB Surface albedo is an important factor governing the surface radiation budget and is critical in modeling the exchange of energy, water and carbon between Earth surface and atmosphere. Global satellite observation systems have been providing surface albedo products periodically. However, due to factors associated with weather, sensors and algorithms, albedo products from satellite observations often have many gaps and low quality pixels. Take the North American Moderate Resolution Imaging Spectroradiometer (MODIS) albedo products (MOD43B3) from 2000-2004 as an example, only 31.3% of pixels were retrieved with fully data-driven inversions and labeled with the highest possible mandatory quality flag of "good''. Conversely, 13.3% did not contain any valid retrieval and the remaining values vary in quality from moderate full inversions to poor retrievals utilizing a back-up algorithm. This indicates considerable potential for product improvement through the use of gap-filling algorithms. Our objective is to generate spatially and temporally continuous albedo products through gap filling and filtering based on multiyear observations and high quality neighboring pixels. The resultant albedo data set substantially improves the time series of surface albedo, especially in the winter, when for some areas the MODIS albedo products may have no retrievals. A comparison with field measurements shows that the filtered albedo correlates well with the measured surface albedo with the root mean squared errors (RMSEs) around 0.064 for snow-free pixels and 0.078 overall. The generated spectral albedo, broadband albedo and monthly albedo can be used for climate modeling and data assimilation applications. C1 [Dickinson, Robert E.] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. [Liang, Shunlin; Kim, Hye-Yun; Townshend, John R.] Univ Maryland, Dept Geog, College Pk, MD 20742 USA. [Schaaf, Crystal L.; Strahler, Alan H.] Boston Univ, Dept Geog & Environm, Boston, MA 02215 USA. [Fang, Hongliang] RS Informat Syst Inc, NASA, GES DISC, Mclean, VA 22102 USA. RP Fang, HL (reprint author), RS Informat Syst Inc, NASA, GES DISC, Mclean, VA 22102 USA. EM hfang@geog.umd.edu RI liang, shunlin/C-2809-2015 FU NASA [NNG04GL85G] FX The work was partially supported by NASA under NNG04GL85G. We thank the FLUXNET and SURFRAD networks which made the surface flux measurements available and the Greenland Climate Network (GC-Net) which provided the albedo data at Greenland. We also thank the support team at the Land Processes Distributed Active Archive Center (DAAC) (http://LPDAAC.usgs.gov), who helped set up the Machine-to-Machine Search and Order Gateway (MTMGW) which greatly facilitated the MODIS data downloading from the EROS Data Center (EDC). The filtered albedo data sets are available from the University of Maryland Global Land Cover Facility (http://www.landcover.org/index.shtml). The anonymous reviewers all made valuable comments that improved this manuscript. NR 33 TC 17 Z9 19 U1 1 U2 7 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 OCT 20 PY 2007 VL 112 IS D20 AR D20206 DI 10.1029/2006JD008377 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348BA UT WOS:000259184600007 ER PT J AU Yang, Q Cunnold, DM Wang, HJ Froidevaux, L Claude, H Merrill, J Newchurch, M Oltmans, SJ AF Yang, Q. Cunnold, D. M. Wang, H. -J. Froidevaux, L. Claude, H. Merrill, J. Newchurch, M. Oltmans, S. J. TI Midlatitude tropospheric ozone columns derived from the aura ozone monitoring instrument and microwave limb sounder measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MAPPING SPECTROMETER TOMS; POTENTIAL VORTICITY; EOS MLS; SATELLITE; CLIMATOLOGY; HEMISPHERE; RADIANCES; TROPICS AB Tropospheric ozone columns derived from differences between the Dutch-Finnish Aura Ozone Monitoring Instrument (OMI) measurements of the total atmospheric ozone column and the Aura Microwave Limb Sounder (MLS) measurements of stratospheric ozone columns are discussed. Because the measurements by these two instruments are not spatially coincident, interpolation techniques, with emphasis on mapping the stratospheric columns in space and time using the relationships between lower stratospheric ozone and potential vorticities (PV) and geopotential heights (Z), are evaluated. It is shown that this PV mapping procedure produces somewhat better agreement in comparisons with ozonesonde measurements, particularly in winter, than does simple linear interpolation of the MLS stratospheric columns or the use of typical coincidence criteria. The OMI/MLS derived tropospheric columns are calculated to be 4 Dobson units (DU) smaller than the sonde measured columns. This mean difference is consistent with the MLS (version 1.5) stratospheric ozone columns being high relative to Stratospheric Aerosol and Gas Experiment ( SAGE II) columns by 3 DU. Standard deviations between the derived tropospheric columns and those measured by ozonesondes are 9 DU (30%) annually but they are just 6 DU (15%) in summer. Uncertainties in the interpolated MLS stratospheric columns are likely to be the primary cause of these standard deviations. An important advantage of the PV mapping approach is that it works well when MLS data are missing (e. g., when an orbit of measurements is missing). In the comparisons against ozonesonde measurements, it provides up to twice as many comparisons compared to the other techniques. C1 [Yang, Q.; Cunnold, D. M.; Wang, H. -J.] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. [Claude, H.] German Weather Serv, Hohenpeissenberg Observ, D-82382 Hohenpeissenberg, Germany. [Froidevaux, L.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Merrill, J.] Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. [Newchurch, M.] Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35899 USA. [Oltmans, S. J.] NOAA, Global Monitoring Div, Earth Syst Res Lab, Boulder, CO 80305 USA. RP Yang, Q (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, 311 Ferst Dr, Atlanta, GA 30332 USA. EM qyang@eas.gatech.edu RI Yang, Qing/H-3275-2011 OI Yang, Qing/0000-0003-2067-5999 NR 31 TC 16 Z9 16 U1 2 U2 4 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 OCT 20 PY 2007 VL 112 IS D20 AR D20305 DI 10.1029/2007JD008528 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348BA UT WOS:000259184600009 ER PT J AU Piatek, JL Hardgrove, C Moersch, JE Drake, DM Wyatt, MB Rampey, M Carlisle, O Warren-Rhodes, K Dohm, JM Hock, AN Cabrol, NA Wettergreen, DS Grin, EA Diaz, GC Coppin, P Weinstein, S Cockell, CS Marinangeli, L Ori, GG Smith, T Jonak, D Wagner, M Stubbs, K Thomas, G Pudenz, E Glasgow, J AF Piatek, Jennifer L. Hardgrove, Craig Moersch, Jeffrey E. Drake, Darrell M. Wyatt, Michael B. Rampey, Michael Carlisle, Orion Warren-Rhodes, Kim Dohm, James M. Hock, Andrew N. Cabrol, Nathalie A. Wettergreen, David S. Grin, Edmond A. Diaz, Guillermo Chong Coppin, Peter Weinstein, Shmuel Cockell, Charles S. Marinangeli, Lucia Ori, Gian Gabriele Smith, Trey Jonak, Dominic Wagner, Michael Stubbs, Kristen Thomas, Geb Pudenz, Erin Glasgow, Justin TI Surface and subsurface composition of the Life in the Atacama field sites from rover data and orbital image analysis SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES LA English DT Article ID SPACEBORNE THERMAL EMISSION; REFLECTION RADIOMETER ASTER; NORTHERN CHILE; DESERT; SPECTRA; SOILS; MINERALS; SPECTROSCOPY; SULFATE; SYSTEM AB The Life in the Atacama project examined six different sites in the Atacama Desert (Chile) over 3 years in an attempt to remotely detect the presence of life with a rover. The remote science team, using only orbital and rover data sets, identified areas with a high potential for life as targets for further inspection by the rover. Orbital data in the visible/near infrared (VNIR) and in the thermal infrared (TIR) were used to examine the mineralogy, geomorphology, and chlorophyll potential of the field sites. Field instruments included two spectrometers (VNIR reflectance and TIR emission) and a neutron detector: this project represents the first time a neutron detector has been used as part of a "science-blind'' rover field test. Rover-based spectroscopy was used to identify the composition of small scale features not visible in the orbital images and to improve interpretations of those data sets. The orbital and ground-based data sets produced consistent results, suggesting that much of the field sites consist of altered volcanic terrains with later deposits of sulfates, quartz, and iron oxides. At one location (Site A), the ground-based spectral data revealed considerably greater compositional diversity than was seen from the orbital view. One neutron detector transect provided insight into subsurface hydrogen concentrations, which correlated with life and surface features. The results presented here have implications for targeting strategies, especially for future Mars rover missions looking for potential habitats/paleohabitats. C1 [Piatek, Jennifer L.; Hardgrove, Craig; Moersch, Jeffrey E.; Rampey, Michael] Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. [Wyatt, Michael B.] Arizona State Univ, Dept Geol Sci, Tempe, AZ USA. [Carlisle, Orion] Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. [Warren-Rhodes, Kim; Cabrol, Nathalie A.; Grin, Edmond A.] NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. [Cabrol, Nathalie A.; Grin, Edmond A.] SETI Inst, Mountain View, CA USA. [Dohm, James M.] Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. [Hock, Andrew N.] Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. [Wettergreen, David S.; Smith, Trey; Jonak, Dominic; Wagner, Michael; Stubbs, Kristen] Carnegie Mellon Univ, Inst Robot, Pittsburgh, PA 15213 USA. [Diaz, Guillermo Chong] Univ Catolica Norte, Antofagasta, Chile. [Coppin, Peter] Carnegie Mellon Univ, Remote Experience & Learning Lab, Pittsburgh, PA 15217 USA. [Weinstein, Shmuel] Carnegie Mellon Univ, Mellon Inst, Mol Biosensor & Imaging Ctr, Pittsburgh, PA 15213 USA. [Cockell, Charles S.] Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. [Marinangeli, Lucia; Ori, Gian Gabriele] Int Res Sch Planetary Sci, I-65127 Pescara, Italy. [Thomas, Geb; Pudenz, Erin; Glasgow, Justin] Univ Iowa, GROK Lab, Iowa City, IA 52242 USA. RP Piatek, JL (reprint author), Cent Connecticut State Univ, Dept Phys & Earth Sci, New Britain, CT 06050 USA. RI Moersch, Jeffrey/F-7189-2010; Hardgrove, Craig/C-7333-2011; Dohm, James/A-3831-2014; OI ORI, Gian Gabriele/0000-0002-6460-1476 NR 42 TC 3 Z9 3 U1 0 U2 9 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 OCT 20 PY 2007 VL 112 IS G4 AR G04S04 DI 10.1029/2006JG000317 PG 25 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 348BB UT WOS:000259184800001 ER PT J AU Matsoukas, C Banks, AC Pavlakis, KG Hatzianastassiou, N Stackhouse, PW Vardavas, I AF Matsoukas, C. Banks, A. C. Pavlakis, K. G. Hatzianastassiou, N. Stackhouse, P. W., Jr. Vardavas, I. TI Seasonal heat budgets of the Red and Black seas SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID LONGWAVE RADIATION BUDGET; FRESH-WATER BUDGETS; MEDITERRANEAN-SEA; NORTHERN-HEMISPHERE; CLIMATOLOGICAL DATA; ATMOSPHERIC ANALYSIS; FLUX CLIMATOLOGY; OCEAN SURFACE; MODEL; REANALYSIS AB In this study we calculate the monthly heat budget of the Red and Black Seas and its components: the net solar and net terrestrial fluxes, the sensible and latent heat fluxes, and the monthly heat content change. A radiation transfer model is employed for the estimation of the net solar and terrestrial energy fluxes, instead of commonly used parameterizations. The agreement with radiation fluxes measured at surface stations is within 10 W m(-2). The Red Sea net solar flux estimate is lower than past studies, while the Black Sea heat budget components are comparable to some past results. The monthly heat content of both seas is estimated from water temperature and salinity profiles and is found to dominate the seasonal energy exchange between the water and the atmosphere, as for the Mediterranean Sea. The latent heat flux is calculated using two methodologies: the bulk aerodynamic and the energy balance method. Our annual results for the Red and Black seas show solar heating of 238 and 139 W m(-2), respectively. The evaporation rates are 2120 and 960 mm yr(-1), respectively. The annual aerosol direct forcing on the net solar flux is -10 W m(-2) and -3 W m(-2). C1 Univ Aegean, Dept Environm, Mitilini, Greece. Fdn Res & Technol Hellas FORTH, Iraklion, Greece. HCMR, Iraklion, Greece. Technol Educ Ins Crete, Dept Gen Appl Sci, Iraklion, Greece. Univ Ioannina, Dept Phys, Lab Meteorol, GR-45110 Ioannina, Greece. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Matsoukas, C (reprint author), Univ Aegean, Dept Environm, Mitilini, Greece. RI Vardavas, Ilias/G-7310-2011 NR 58 TC 5 Z9 5 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD OCT 19 PY 2007 VL 112 IS C10 AR C10017 DI 10.1029/2006JC003849 PG 15 WC Oceanography SC Oceanography GA 224MC UT WOS:000250450100002 ER PT J AU Meshik, A Mabry, J Hohenberg, C Marrocchi, Y Pravdivtseva, O Burnett, D Olinger, C Wiens, R Reisenfeld, D Allton, J McNamara, K Stansbery, E Jurewicz, AJG AF Meshik, Alex Mabry, Jennifer Hohenberg, Charles Marrocchi, Yves Pravdivtseva, Olga Burnett, Donald Olinger, Chad Wiens, Roger Reisenfeld, Dan Allton, Judith McNamara, Karen Stansbery, Eileen Jurewicz, Amy J. G. TI Constraints on neon and argon isotopic fractionation in solar wind SO SCIENCE LA English DT Article ID NOBLE-GASES; GENESIS; EVOLUTION; REGIME; ORIGIN; CORONA; MATTER; ACE; HE AB To evaluate the isotopic composition of the solar nebula from which the planets formed, the relation between isotopes measured in the solar wind and on the Sun's surface needs to be known. The Genesis Discovery mission returned independent samples of three types of solar wind produced by different solar processes that provide a check on possible isotopic variations, or fractionation, between the solar-wind and solar-surface material. At a high level of precision, we observed no significant inter-regime differences in Ne-20/Ne-22 or Ar-36/Ar-38 values. For Ne-20/Ne-22, the difference between low- and high-speed wind components is 0.24 +/- 0.37%; for Ar-36/Ar-38, it is 0.11 +/- 0.26%. Our measured Ar-36/Ar-38 ratio in the solar wind of 5.501 +/- 0.005 is 3.42 +/- 0.09% higher than that of the terrestrial atmosphere, which may reflect atmospheric losses early in Earth's history. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Montana, Dept Phys & Astron, Missoula, MT 59812 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Arizona State Univ, Ctr Meteorite Studies, Tempe, AZ 85287 USA. RP Meshik, A (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA. EM am@physics.wustl.edu RI Reisenfeld, Daniel/F-7614-2015 NR 27 TC 32 Z9 33 U1 1 U2 7 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 OCT 19 PY 2007 VL 318 IS 5849 BP 433 EP 435 DI 10.1126/science.1145528 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 221LW UT WOS:000250230400041 PM 17947578 ER PT J AU Coates, AJ Crary, FJ Young, DT Szego, K Arridge, CS Bebesi, Z Sittler, EC Hartle, RE Hill, TW AF Coates, A. J. Crary, F. J. Young, D. T. Szego, K. Arridge, C. S. Bebesi, Z. Sittler, E. C., Jr. Hartle, R. E. Hill, T. W. TI Ionospheric electrons in Titan's tail: Plasma structure during the cassini T9 encounter SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SPECTROMETER; VOYAGER-1; MODEL AB We present results from the CAPS electron spectrometer obtained during the downstream flyby of Titan on 26 December 2005, which occurred during a period of enhanced plasma pressure inside the magnetosphere. The electron data show an unusual split signature with two principal intervals of interest outside the nominal corotation wake. Interval 1 shows direct evidence for ionospheric plasma escape at several RT in Titan's tail. Interval 2 shows a complex plasma structure, a mix between plasma of ionospheric and magnetospheric origin. We suggest a mechanism for plasma escape based on ambipolar electric fields set up by suprathermal ionospheric photoelectrons. C1 UCL, Mullard Space Sci Lab, London WC1E 6BT, England. SW Res Inst, Space Sci & Engn, San Antonio, TX 78228 USA. Hungarian Acad Sci, Cent Re Inst Phys, Res Inst Particle & Nucl Phys, Budapest, Hungary. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. RP Coates, AJ (reprint author), UCL, Mullard Space Sci Lab, Holbury St Mary, London WC1E 6BT, England. EM ajc@mssl.ucl.ac.uk RI Arridge, Christopher/A-2894-2009; Coates, Andrew/C-2396-2008 OI Arridge, Christopher/0000-0002-0431-6526; Coates, Andrew/0000-0002-6185-3125 FU Science and Technology Facilities Council [PP/D00084X/1] NR 27 TC 64 Z9 64 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 OCT 18 PY 2007 VL 34 IS 24 AR L24S05 DI 10.1029/2007GL030919 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 224LI UT WOS:000250448100003 ER PT J AU Koren, I Remer, LA Longo, K AF Koren, Ilan Remer, Lorraine A. Longo, Karla TI Reversal of trend of biomass burning in the Amazon SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SMOKE AB We use MODIS aerosol optical depth and AVHRR fire counts over the Amazon Basin to determine whether biomass burning is increasing or decreasing over continental scales in South America. We find a significant sustained increasing trend in both the seasonal mean optical depth and fire data that begins in the year 2000 and 1998, respectively, and continues through 2005. However, there is a sharp reversal of this trend in 2006 that causes the overall trend to become less significant. The sharp decrease of biomass burning in 2006 is linked to a tri-national policy shift first implemented in 2006. The results show how significantly human activity can affect the large scale environment. C1 Weizmann Inst Sci, Dept Environm Sci, IL-76100 Rehovot, Israel. Inst Nacl Pesquisas Espaciais, Ctr Weather Forecasting & Climate Studies, BR-12227010 Cachoeira Paulista, SP, Brazil. Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Koren, I (reprint author), Weizmann Inst Sci, Dept Environm Sci, IL-76100 Rehovot, Israel. EM ilan.koren@weizmann.ac.il RI Koren, Ilan/K-1417-2012 OI Koren, Ilan/0000-0001-6759-6265 NR 17 TC 41 Z9 41 U1 0 U2 3 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 OCT 18 PY 2007 VL 34 IS 20 AR L20404 DI 10.1029/2007GL031530 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 224KY UT WOS:000250447100005 ER PT J AU Kinnison, DE Brasseur, GP Walters, S Garcia, RR Marsh, DR Sassi, F Harvey, VL Randall, CE Emmons, L Lamarque, JF Hess, P Orlando, JJ Tie, XX Randel, W Pan, LL Gettelman, A Granier, C Diehl, T Niemeier, U Simmons, AJ AF Kinnison, D. E. Brasseur, G. P. Walters, S. Garcia, R. R. Marsh, D. R. Sassi, F. Harvey, V. L. Randall, C. E. Emmons, L. Lamarque, J. F. Hess, P. Orlando, J. J. Tie, X. X. Randel, W. Pan, L. L. Gettelman, A. Granier, C. Diehl, T. Niemeier, U. Simmons, A. J. TI Sensitivity of chemical tracers to meteorological parameters in the MOZART-3 chemical transport model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE-TROPOSPHERE EXCHANGE; GENERAL-CIRCULATION MODEL; MIDDLE ATMOSPHERE; WATER-VAPOR; 3-DIMENSIONAL SIMULATION; INITIATIVE ASSESSMENT; GLOBAL SIMULATION; CLIMATE MODEL; MEAN AGES; OZONE AB The Model for Ozone and Related Chemical Tracers, version 3 (MOZART-3), which represents the chemical and physical processes from the troposphere through the lower mesosphere, was used to evaluate the representation of long- lived tracers and ozone using three different meteorological fields. The meteorological fields are based on (1) the Whole Atmosphere Community Climate Model, version 1b (WACCM1b), (2) the European Centre for Medium- Range Weather Forecasts (ECMWF) operational analysis, and (3) a new reanalysis for year 2000 from ECMWF called EXP471. Model-derived tracers (methane, water vapor, and total inorganic nitrogen) and ozone are compared to data climatologies from satellites. Model mean age of air was also derived and compared to in situ CO2 and SF6 data. A detailed analysis of the chemical fields simulated by MOZART-3 shows that even though the general features characterizing the three dynamical sets are rather similar, slight differences in winds and temperature can produce substantial differences in the calculated distributions of chemical tracers. The MOZART-3 simulations that use meteorological fields from WACCM1b and ECMWF EXP471 represented best the distribution of long-lived tracers and mean age of air in the stratosphere. There was a significant improvement using the ECMWF EXP471 reanalysis data product over the ECMWF operational data product. The effect of the quasi- biennial oscillation circulation on long- lived tracers and ozone is examined. C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80301 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Paris 06, Serv Aeron, Paris, France. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England. RP Kinnison, DE (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, 3450 Mitchell Lane, Boulder, CO 80301 USA. RI Granier, Claire/D-5360-2013; Marsh, Daniel/A-8406-2008; Pan, Laura/A-9296-2008; Lamarque, Jean-Francois/L-2313-2014; Hess, Peter/M-3145-2015; Randall, Cora/L-8760-2014; Randel, William/K-3267-2016; Emmons, Louisa/R-8922-2016 OI Granier, Claire/0000-0001-7344-7995; Marsh, Daniel/0000-0001-6699-494X; Pan, Laura/0000-0001-7377-2114; Lamarque, Jean-Francois/0000-0002-4225-5074; Hess, Peter/0000-0003-2439-3796; Randall, Cora/0000-0002-4313-4397; Randel, William/0000-0002-5999-7162; Emmons, Louisa/0000-0003-2325-6212 NR 77 TC 176 Z9 179 U1 7 U2 26 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 OCT 17 PY 2007 VL 112 IS D20 AR D20302 DI 10.1029/2006JD007879 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 224LV UT WOS:000250449400001 ER PT J AU McGill, MJ Vaughan, MA Trepte, CR Hart, WD Hlavka, DL Winker, DM Kuehn, R AF McGill, Matthew J. Vaughan, Mark A. Trepte, Charles R. Hart, William D. Hlavka, Dennis L. Winker, David M. Kuehn, Ralph TI Airborne validation of spatial properties measured by the CALIPSO lidar SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MISSION; AEROSOL; CLOUD; RETRIEVAL; WATER AB The Cloud-Aerosol Lidar Infrared Pathfinder Satellite Observations (CALIPSO) satellite provides a new and exciting opportunity to study clouds and aerosols in the Earth's atmosphere using range-resolved laser remote sensing. Following the successful launch of the CALIPSO satellite, validation flights were conducted using the long-established Cloud Physics Lidar (CPL) to verify CALIPSO's calibration and validate various CALIPSO data products. This paper presents results of the initial comparisons made between the spaceborne CALIPSO lidar and the airborne CPL. Results are presented to validate measurement sensitivity and the spatial properties reported in the CALIPSO data products. Cloud layer top determinations from CALIPSO are found to be in good agreement with those from CPL. Determinations of minimum detectable backscatter are in excellent agreement with theoretical values predicted prior to launch. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Hampton, VA USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP McGill, MJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI McGill, Matthew/D-8176-2012; OI Hlavka, Dennis/0000-0002-2976-7243 NR 17 TC 77 Z9 78 U1 1 U2 9 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 OCT 17 PY 2007 VL 112 IS D20 AR D20201 DI 10.1029/2007JD008768 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 224LV UT WOS:000250449400006 ER PT J AU Bogucki, DJ Piskozub, J Carr, ME Spiers, GD AF Bogucki, D. J. Piskozub, J. Carr, M. -E. Spiers, G. D. TI Monte Carlo simulation of propagation of a short light beam through turbulent oceanic flow SO OPTICS EXPRESS LA English DT Article ID SCATTERED LIDAR RETURNS; SURFACE; MODEL AB We use Monte Carlo time-dependent simulations of light pulse propagation through turbulent water laden with particles to investigate the application of Multiple Field Of View MFOV) lidar to detect and characterize oceanic turbulence. Inhomogeneities in the refractive index induced by temperature fluctuations in turbulent ocean flows scatter light in near-forward angles, thus affecting the near-forward part of oceanic water scattering phase function. Our results show that the oceanic turbulent signal can be detected by analyzing the returns from a MFOV lidar, after re-scaling the particulate back scattering phase function. (c) 2007 Optical Society of America. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Appl Marine Phys, Miami, FL 33149 USA. Polish Acad Sci, Sopot, Poland. CALTECH, Jet Propulsion Lab, Pasadena, CA 91101 USA. RP Bogucki, DJ (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Appl Marine Phys, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. EM dbogucki@rsmas.miami.edu RI Piskozub, Jacek/A-5645-2009 OI Piskozub, Jacek/0000-0003-3386-6604 NR 19 TC 11 Z9 14 U1 0 U2 13 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD OCT 17 PY 2007 VL 15 IS 21 BP 13988 EP 13996 DI 10.1364/OE.15.013988 PG 9 WC Optics SC Optics GA 235HA UT WOS:000251223100057 PM 19550672 ER PT J AU Shindell, DT Faluvegi, G Bauer, SE Koch, DM Unger, N Menon, S Miller, RL Schmidt, GA Streets, DG AF Shindell, Drew T. Faluvegi, Greg Bauer, Susanne E. Koch, Dorothy M. Unger, Nadine Menon, Surabi Miller, Ron L. Schmidt, Gavin A. Streets, David G. TI Climate response to projected changes in short-lived species under an A1B scenario from 2000-2050 in the GISS climate model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE-TROPOSPHERE EXCHANGE; METHANE EMISSION CONTROLS; OZONE POLLUTION; ART.; AEROSOL; SIMULATIONS; FUTURE; NITROGEN; AIR; PREINDUSTRIAL AB We investigate the climate forcing from and response to projected changes in short-lived species and methane under an A1B scenario from 2000-2050 in the GISS climate model. We present a meta-analysis of new simulations of the full evolution of gas and aerosol species and other existing experiments with variations of the same model. The comparison highlights the importance of several physical processes in determining radiative forcing, especially the effect of climate change on stratosphere- troposphere exchange, heterogeneous sulfate-nitrate-dust chemistry, and changes in methane oxidation and natural emissions. However, the impact of these fairly uncertain physical effects is substantially less than the difference between alternative emission scenarios for all short- lived species. The net global mean annual average direct radiative forcing from the short-lived species is.02 W/m(2) or less in our projections, as substantial positive ozone forcing is largely offset by negative aerosol direct forcing. Since aerosol reductions also lead to a reduced indirect effect, the global mean surface temperature warms by similar to 0.07 degrees C by 2030 and similar to 0.13 degrees C by 2050, adding 19% and 17%, respectively, to the warming induced by long-lived greenhouse gases. Regional direct forcings are large, up to 3.8 W/m(2). The ensemble-mean climate response shows little regional correlation with the spatial pattern of the forcing, however, suggesting that oceanic and atmospheric mixing generally overwhelms the effect of even large localized forcings. Exceptions are the polar regions, where ozone and aerosols may induce substantial seasonal climate changes. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. Univ Vermont, Dept Atmospher Sci, Burlington, VT USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Shindell, DT (reprint author), NASA, Goddard Inst Space Studies, 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; Bauer, Susanne/P-3082-2014; Unger, Nadine/M-9360-2015; OI Schmidt, Gavin/0000-0002-2258-0486; Streets, David/0000-0002-0223-1350 NR 62 TC 30 Z9 30 U1 1 U2 12 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 OCT 16 PY 2007 VL 112 IS D20 AR D20103 DI 10.1029/2007JD008753 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 224LU UT WOS:000250449300003 ER PT J AU Wade, LA Lo, D Fraser, S Lester, HA AF Wade, Lawrence A. Lo, Daniel Fraser, Scott Lester, Henry A. TI Imaging the microorganization of synaptic receptors SO BIOCHEMICAL PHARMACOLOGY LA English DT Meeting Abstract CT Symposium on Nicotinic Acetylcholine Receptors as Therapeutic Targets CY OCT 31-NOV 02, 2007 CL San Diego, CA SP Abbott Neurosci, AstraZenerca, Roche, Tobacco Rlelatd dis Red Program, CoMentis, GlaxoSmithKline, Lilly, NeuroSearch, Mem Pharmaceut, Sanofi Aventis, Wyeth C1 CALTECH, Div Biol, Pasadena, CA 91125 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. NR 0 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 0006-2952 J9 BIOCHEM PHARMACOL JI Biochem. Pharmacol. PD OCT 15 PY 2007 VL 74 IS 8 BP SMA9 EP SMA9 PG 1 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 220WV UT WOS:000250188900037 ER PT J AU Braun, A Kim, HR Csatho, B von Frese, RRB AF Braun, Alexander Kim, Hyung Rae Csatho, Beata von Frese, Ralph R. B. TI Gravity-inferred crustal thickness of Greenland SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Greenland; gravity; Moho; crustal thickness; generalized isostatic analysis; ice sheet; basal melt; Iceland hotspot ID RECEIVER-FUNCTION-ANALYSIS; ANTARCTIC ICE STREAM; CORRELATED FREE-AIR; BED DATA SET; GEODYNAMIC IMPLICATIONS; TERRAIN GRAVITY; HIGH-RESOLUTION; HOTSPOT TRACKS; NORTH-ATLANTIC; RIFTED MARGIN AB Greenland's crust contains clues for understanding the dynamics of the Earth's second largest ice-sheet, as well as the Iceland hotspot over the past 100 Ma. However, our knowledge of the sub-ice crust is very limited due to the paucity of outcrops and seismic observations, particularly in central Greenland. In order to augment these sparse constraints, we modeled terrain and airborne free-air gravity data which provide estimates for Moho and related crustal thickness. These estimates were obtained from the inversion of isostatically corrected terrain effects where the computed gravity effects of the terrain's rock, water, and ice components were subtracted from the terrain-correlated free-air anomalies. The terrain-correlated free-air components were estimated from the correlation spectrum between the free-air anomalies and the terrain's gravity effects which are assumed to reflect isostatic disturbances of the crustal terrain. The results indicated an average crustal thickness of about 37 km for Greenland, with greater values by 5-10 km, in the southern Greenland Archean blocks and Caledonian Foldbelt, and comparably lower values in northern Greenland. The thinner crustal thickness estimates in the north are strongly correlated with the faster basal melt regions of the ice sheet and glaciers. The crustal thickness map provides constraints for an improved interpretation of the Iceland hotspot track in northern Greenland at about 100-70 Ma. (c) 2007 Elsevier B.V. All rights reserved. C1 Univ Calgary, Schulich Sch Engn, Dept Geomat Engn, Calgary, AB T2N 1N4, Canada. NASA, Goddard Space Flight Ctr, GEST UMBC, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. SUNY Buffalo, Dept Geol, Buffalo, NY 14260 USA. Ohio State Univ, Sch Earth Sci, Mendenhall Lab 275, Columbus, OH 43210 USA. RP Braun, A (reprint author), Univ Calgary, Schulich Sch Engn, Dept Geomat Engn, 2500 Univ Dr NW, Calgary, AB T2N 1N4, Canada. EM braun@ucalgary.ca NR 65 TC 18 Z9 20 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD OCT 15 PY 2007 VL 262 IS 1-2 BP 138 EP 158 DI 10.1016/j.epsl.2007.07.050 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 227JL UT WOS:000250652900010 ER PT J AU Futyan, JM Del Genio, AD AF Futyan, Joanna M. Del Genio, Anthony D. TI Deep convective system evolution over Africa and the tropical Atlantic SO JOURNAL OF CLIMATE LA English DT Article ID TRMM PRECIPITATION RADAR; WEST-AFRICAN; VERTICAL VELOCITY; SQUALL LINE; LIGHTNING CHARACTERISTICS; GEOSTATIONARY SATELLITE; SCALE DEPENDENCE; FLUX ESTIMATION; EASTERLY WAVES; ICE-SCATTERING AB In the tropical African and neighboring Atlantic region there is a strong contrast in the properties of deep convection between land and ocean. Here, satellite radar observations are used to produce a composite picture of the life cycle of convection in these two regions. Estimates of the broadband thermal flux from the geostationary Meteosat-8 satellite are used to identify and track organized convective systems over their life cycle. The evolution of the system size and vertical extent are used to define five life cycle stages ( warm and cold developing, mature, cold and warm dissipating), providing the basis for the composite analysis of the system evolution. The tracked systems are matched to overpasses of the Tropical Rainfall Measuring Mission satellite, and a composite picture of the evolution of various radar and lightning characteristics is built up. The results suggest a fundamental difference in the convective life cycle between land and ocean. African storms evolve from convectively active systems with frequent lightning in their developing stages to more stratiform conditions as they dissipate. Over the Atlantic, the convective fraction remains essentially constant into the dissipating stages, and lightning occurrence peaks late in the life cycle. This behavior is consistent with differences in convective sustainability in land and ocean regions as proposed in previous studies. The area expansion rate during the developing stages of convection is used to provide an estimate of the intensity of convection. Reasonable correlations are found between this index and the convective system lifetime, size, and depth. C1 Columbia Univ, Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Math & Appl Phys, New York, NY 10025 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Futyan, JM (reprint author), Columbia Univ, Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM jfutyan@giss.nasa.gov RI Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 72 TC 60 Z9 60 U1 1 U2 8 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 OCT 15 PY 2007 VL 20 IS 20 BP 5041 EP 5060 DI 10.1175/JCLI4297.1 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 219SU UT WOS:000250105900002 ER PT J AU Oreopoulos, L Cahalan, RF Platnick, S AF Oreopoulos, Lazaros Cahalan, Robert F. Platnick, Steven TI The plane-parallel albedo bias of liquid clouds from MODIS observations SO JOURNAL OF CLIMATE LA English DT Article ID DROPLET EFFECTIVE RADIUS; HORIZONTAL VARIATIONS; GENERAL-CIRCULATION; RADIATIVE-TRANSFER; SOLAR FLUXES; MODELS; WATER; PARAMETERIZATION; BUDGET AB The authors present the global plane-parallel shortwave albedo bias of liquid clouds for two months, July 2003 and January 2004. The cloud optical properties necessary to perform the bias calculations come from the operational Moderate Resolution Imaging Spectroradiometer ( MODIS) Terra and MODIS Aqua level-3 datasets. These data, along with ancillary surface albedo and atmospheric information consistent with the MODIS retrievals, are inserted into a broadband shortwave radiative transfer model to calculate the fluxes at the atmospheric column boundaries. The plane-parallel homogeneous ( PPH) calculations are based on the mean cloud properties, while independent column approximation ( ICA) calculations are based either on 1D histograms of optical thickness or joint 2D histograms of optical thickness and effective radius. The ( positive) PPH albedo bias is simply the difference between PPH and ICA albedo calculations. Two types of biases are therefore examined: 1) the bias due to the horizontal inhomogeneity of optical thickness alone ( the effective radius is set to the grid mean value) and 2) the bias due to simultaneous variations of optical thickness and effective radius as derived from their joint histograms. The authors find that the global bias of albedo ( liquid cloud portion of the grid boxes only) is similar to+0.03, which corresponds to roughly 8% of the global liquid cloud albedo and is only modestly sensitive to the inclusion of horizontal effective radius variability and time of day, but depends strongly on season and latitude. This albedo bias translates to similar to 3-3.5 W m(-2) of bias ( stronger negative values) in the diurnally averaged global shortwave cloud radiative forcing, assuming homogeneous conditions for the fraction of the grid box not covered by liquid clouds; zonal values can be as high as 8 W m(-2). Finally, the ( positive) broadband atmospheric absorptance bias is about an order of magnitude smaller than the albedo bias. The substantial magnitude of the PPH bias underlines the importance of predicting subgrid variability in GCMs and accounting for its effects on cloud-radiation interactions. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland, Joint Ctr Earth Syst Technol, Baltimore, MD 21201 USA. RP Oreopoulos, L (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 613-2, Greenbelt, MD 20771 USA. EM lazaros@climate.gsfc.nasa.gov RI Oreopoulos, Lazaros/E-5868-2012; Cahalan, Robert/E-3462-2012; Platnick, Steven/J-9982-2014 OI Oreopoulos, Lazaros/0000-0001-6061-6905; Cahalan, Robert/0000-0001-9724-1270; Platnick, Steven/0000-0003-3964-3567 NR 20 TC 11 Z9 11 U1 1 U2 3 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 OCT 15 PY 2007 VL 20 IS 20 BP 5114 EP 5125 DI 10.1175/JCLI4305.1 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 219SU UT WOS:000250105900006 ER PT J AU Lay, OP Dubovitsky, S Shaddock, DA Ware, B AF Lay, O. P. Dubovitsky, S. Shaddock, D. A. Ware, B. TI Coherent range-gated laser displacement metrology with compact optical head SO OPTICS LETTERS LA English DT Article ID NONLINEARITY; SYSTEM AB We describe a new architecture for laser displacement metrology with a drastic reduction in the size and complexity of the optical head. Connected by a single optical fiber, the compact heads are easy to integrate and readily multiplexed to support applications requiring large numbers of sensors. The approach is made possible by modulating the outgoing laser light with a binary random noise code allowing the detected signals to be discriminated based on their propagation delay. We demonstrate a displacement resolution of 1.1 nm rms. (C) 2007 Optical Society of America C1 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. EM oliver.p.lay@jpl.nasa.gov RI Shaddock, Daniel/A-7534-2011 OI Shaddock, Daniel/0000-0002-6885-3494 NR 9 TC 11 Z9 11 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD OCT 15 PY 2007 VL 32 IS 20 BP 2933 EP 2935 DI 10.1364/OL.32.002933 PG 3 WC Optics SC Optics GA 229BG UT WOS:000250775700011 PM 17938657 ER PT J AU Gatski, TB Rumsey, CL Manceau, R AF Gatski, Thomas B. Rumsey, Christopher L. Manceau, Remi TI Current trends in modelling research for turbulent aerodynamic flows SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE turbulence; turbulence modelling; hybrid methods flow control; computational fluid dynamics ID DIRECT NUMERICAL-SIMULATION; BOUNDARY-LAYER-TRANSITION; REYNOLDS-STRESS CLOSURES; EDDY-VISCOSITY MODEL; NEAR-WALL TURBULENCE; DISSIPATION RATE; ELLIPTIC RELAXATION; TRANSPORT-EQUATIONS; CHANNEL FLOW; MOUNTED HUMP AB The engineering tools of choice for the computation of practical engineering. flows have begun to migrate from those based on the traditional Reynolds- averaged Navier - Stokes approach to methodologies capable, in theory if not in practice, of accurately predicting some instantaneous scales of motion in the. flow. The migration has largely been driven by both the success of Reynolds- averaged methods over a wide variety of. flows and the inherent limitations of the method itself. Practitioners, emboldened by their ability to predict a wide variety of statistically steady equilibrium turbulent. flows, have now turned their attention to. flow control and non- equilibrium. flows, i. e. separation control. This review gives some current priorities in traditional Reynolds- averaged modelling research as well as some methodologies being applied to a new class of turbulent. flow control problem. C1 Univ Poitiers, CNRS, UMR 6609, ENSMA Lab Etudes Aerodynam, F-86962 Futuroscope, France. NASA, Langley Res Ctr, Computat AeroSci Branch, Hampton, VA 23681 USA. RP Gatski, TB (reprint author), Old Dominion Univ, Ctr Coastal Phys Oceanog & Ocean Earth & AS, Norfolk, VA 23529 USA. EM t.b.gatski@widomaker.com RI Manceau, Remi/B-3943-2012; OI Manceau, Remi/0000-0002-3964-161X NR 81 TC 22 Z9 22 U1 0 U2 8 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD OCT 15 PY 2007 VL 365 IS 1859 BP 2389 EP 2418 DI 10.1098/rsta.2007.2015 PG 30 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 209XX UT WOS:000249422400002 PM 17519202 ER PT J AU Bartels, RE Sayma, AI AF Bartels, R. E. Sayma, A. I. TI Computational aeroelastic modelling of airframes and turbomachinery : progress and challenges SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Review DE computational aeroelasticity; computational fluid dynamics; airframes; turbomachinery ID LIMIT-CYCLE OSCILLATIONS; INTEGRATED NONLINEAR APPROACH; FORCED RESPONSE PREDICTION; REDUCED-ORDER MODELS; UNSTEADY FLOWS; EULER EQUATIONS; FIGHTER AIRCRAFT; COUPLED SOLUTION; FLUTTER ANALYSIS; TRANSONIC FLOW AB Computational analyses such as computational. fluid dynamics and computational structural dynamics have made major advances towards maturity as engineering tools. Computational aeroelasticity ( CAE) is the integration of these disciplines. As CAE matures, it also. finds an increasing role in the design and analysis of aerospace vehicles. This paper presents a survey of the current state of CAE with a discussion of recent research, success and continuing challenges in its progressive integration into multi-disciplinary aerospace design. It approaches CAE from the perspective of the two main areas of application: airframe and turbomachinery design. An overview will be presented of the different prediction methods used for each. field of application. Differing levels of nonlinear modelling will be discussed with insight into accuracy versus complexity and computational requirements. Subjects will include current advanced methods ( linear and nonlinear), nonlinear. flow models, use of order reduction techniques and future trends in incorporating structural nonlinearity. Examples in which CAE is currently being integrated into the design of airframes and turbomachinery will be presented. C1 NASA, Langley Res Ctr, Aeroelasticity Branch, Hampton, VA 23681 USA. Univ Sussex, Thermo Fluid Mech Res Ctr, Brighton BN1 9QT, E Sussex, England. RP Bartels, RE (reprint author), NASA, Langley Res Ctr, Aeroelasticity Branch, Hampton, VA 23681 USA. EM robert.e.bartels@nasa.gov NR 126 TC 11 Z9 11 U1 2 U2 9 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X EI 1471-2962 J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD OCT 15 PY 2007 VL 365 IS 1859 BP 2469 EP 2499 DI 10.1098/rsta.2007.2018 PG 31 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 209XX UT WOS:000249422400005 PM 17519199 ER PT J AU Numata, K Horowitz, J Camp, J AF Numata, Kenji Horowitz, Jordan Camp, Jordan TI Coated fused silica fibers for enhanced sensitivity torsion pendulum for LISA SO PHYSICS LETTERS A LA English DT Article DE fused silica; torsion pendulum; quality factor; thermal noise; thin film; gravitational wave detectors ID LOSSES AB In order to investigate the fundamental thermal noise limit of a torsion pendulum using a fused silica fiber, we systematically measured and modeled the mechanical losses of thin fused silica fibers coated by electrically conductive thin metal films. Our results indicate that it is possible to achieve a thermal noise limit for coated silica a factor of 9 lower than obtained with the tungsten fiber used in the recent LISA torsion pendulum study [L. Carbone, et al., Phys. Rev. Lett. 91 (2003) 151101]. This will allow a corresponding increase in sensitivity of torsion pendula used for small force measurements. (C) 2007 Elsevier B.V. All rights reserved. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, CRESST, Greenbelt, MD 20771 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Numata, K (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM numata@milkyway.gsfc.nasa.gov RI Horowitz, Jordan/C-6754-2009 OI Horowitz, Jordan/0000-0002-9139-0811 NR 23 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD OCT 15 PY 2007 VL 370 IS 2 BP 91 EP 98 DI 10.1016/j.physleta.2007.05.048 PG 8 WC Physics, Multidisciplinary SC Physics GA 226LW UT WOS:000250591600001 ER PT J AU Ahn, C Birnbaum, K AF Ahn, Charlene Birnbaum, Kevin TI Exposed-key weakness of alpha eta SO PHYSICS LETTERS A LA English DT Article DE quantum encryption ID SECURITY; Y-00; PROTOCOL; ATTACKS AB The call protocol given by Barbosa et al. [G.A. Barbosa, E. Corndorf, P. Kumar, H.P. Yuen, Phys. Rev. Lett. 90 (2003) 227901, quant-ph/0212018] claims to be a secure way of encrypting messages using mesoscopic coherent states. We show that transmission under alpha eta) exposes information about the secret key to an eavesdropper, and we estimate the rate at which an eavesdropper can learn about the key. We also consider the consequences of using further randomization to protect the key and how our analysis applies to this case. We conclude that alpha eta is not informationally secure. (C) 2007 Published by Elsevier B.V. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Toyon Res Corp, Goleta, CA 93117 USA. RP Birnbaum, K (reprint author), CALTECH, Jet Prop Lab, M-S 161-135,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM cahn@toyon.com; kevin.m.birnbaum@jpl.nasa.gov NR 15 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD OCT 15 PY 2007 VL 370 IS 2 BP 131 EP 135 DI 10.1016/j.physleta.2007.05.052 PG 5 WC Physics, Multidisciplinary SC Physics GA 226LW UT WOS:000250591600009 ER PT J AU Guest, A Smrekar, SE AF Guest, Alice Smrekar, Suzanne E. TI New constraints on the thermal and volatile evolution of Mars SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article DE mars; elastic thickness; thermal evolution; water; relaxation modeling ID EARLY PLATE-TECTONICS; VISCOUS RELAXATION; CRUSTAL THICKNESS; MAGNETIC-FIELD; LITHOSPHERE; TOPOGRAPHY; GRAVITY; PLANETS; DIABASE; HISTORY AB The thermal and volatile evolution of Mars has not been studied from the perspective of consistency with the preservation of the Martian global dichotomy and with estimates of the elastic thickness over time. We use three thermal evolution models for Mars: (1) stagnant lid, (2) early plate tectonics followed by stagnant lid, and (3) mantle overturn, to calculate the amount of relaxation of the dichotomy boundary and elastic thickness values for Noachian- and Hesperian-aged terrains. To explore a wide range of parameters, we evaluate two different initial mantle temperatures, and wet and dry rheologies. Our model results show that the relative water content of the crust has an effect roughly equal to 500 K variations of initial mantle temperature. For all three thermal models, a lower crust viscosity of 10(20)-10(21) Pa s during the first 0.1 Ga after formation of dichotomy would allow for the preservation of the long-wavelength topography of Mars and fitting of the elastic thickness. This viscosity range implies either wet, cold (similar to 1500 K) lower crust, or dry, hot (similar to 2000 K) lower crust in Noachian. Additional constraints are necessary to distinguish between the individual thermal models. For the stagnant lid model, neither the cold, wet crust nor the hot, dry crust agree with timing and amount of the crustal production [Hauck II., S.A., Phillips, R.J., 2002. Thermal and crustal evolution of Mars. J. Geophys. Res. 107, 5052]. Moreover, drying of the crust is required for this model in order to match the admittance elastic thickness at the Hesperian/Amazonian boundary implying remelting of the crust. The hot, dry crust in the early plate tectonics model limits a plate tectonic epoch to only 100-200 Myr and implies dry mantle, which is in disagreement with water found in meteorites. The cold, wet crustal rheology implies the formation of crust during the plate tectonics regime because of the low crustal production during the stagnant lid regime. For mantle overturn, the temperature required for wet crust does not fit the original mantle profile while the dry crust does; however, in order to explain the initially hot thermal profile the crust must have been emplaced very fast. Generally, dry crustal rheology does not fit low elastic values in the Hesperian and implies either that rheology may differ between the southern and northern hemispheres: wet in northern hemisphere and dry in southern hemisphere, or that local weakening occurred. Wet crustal rheology fits well all elastic data except S. Hellas rim, which may be anomalous. Mantle rheology is unconstrained by our modeling and can be either dry or wet. (C) 2007 Published by Elsevier B.V. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91106 USA. RP Guest, A (reprint author), LMU Munchen, Dept Geo & Environm Sci, Luisenstr 37, D-80333 Munich, Germany. EM alice.guest@seznam.cz; ssmrekar@jpl.nasa.gov NR 45 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 EI 1872-7395 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD OCT 15 PY 2007 VL 164 IS 3-4 BP 161 EP 176 DI 10.1016/j.pepi.2007.06.010 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 224VD UT WOS:000250473900003 ER PT J AU Naesset, E Nelson, R AF Naesset, Erik Nelson, Ross TI Using airborne laser scanning to monitor tree migration in the boreal-alpine transition zone SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE forest monitoring; global change; laser scanning; PCQ sampling; small trees; tree growth; tree line; tree migration ID FOREST STAND CHARACTERISTICS; CANOPY HEIGHT; STEM VOLUME; LIDAR; ACCURACY; INVENTORY; MODELS AB The boreal tree line is expected to advance upwards into the mountains and northwards into the tundra due to global warming. The major objective of this study was to find out if it is possible to use high-resolution airborne laser scanner data to detect very small trees - the pioneers that are pushing the tree line up into the mountains and out onto the tundra. The study was conducted in a sub-alpine/alpine environment in southeast Norway. A total of 342 small trees of Norway spruce, Scots pine, and downy birch with tree heights ranging from 0.11 to 5.20 in were precisely georeferenced and measured in field. Laser data were collected with a pulse density of 7.7 m(-2). Three different terrain models were used to process the airborne laser point cloud in order to assess the effects of different pre-processing parameters on small tree detection. Greater than 91 % of all trees > 1 in tall registered positive laser height values regardless of terrain model. For smaller trees (< 1 m), positive height values were found in 5-73% of the cases, depending on the terrain model considered. For this group of trees, the highest rate of trees with positive height values was found for spruce. The more smoothed the terrain model was, the larger the portion of the trees that had positive laser height values. The accuracy of tree height derived from the laser data indicated a systematic underestimation of true tree height by 0.40 to 1.01 m. The standard deviation for the differences between laser-derived and field-measured tree heights was 0.11-0.73 m Commission errors, i.e., the detection of terrain objects - rocks, hummocks - as trees, increased significantly as terrain smoothing increased. Thus, if no classification of objects into classes like small trees and terrain objects is possible, many non-tree objects with a positive height value cannot be separated from those actually being trees. In a monitoring context, i.e., repeated measurements over time, we argue that most other objects like terrain structures, rocks, and hummocks will remain stable over time while the trees will change as they grow and new trees are established. Thus, this study indicates that, given a high laser pulse density and a certain density of newly established trees, it would be possible to detect a sufficient portion of newly established trees over a 10 years period to claim that tree migration is taking place. Published by Elsevier Inc. C1 Norwegian Univ Life Sci, Dept Ecol & Nat Resource Management, NO-1432 As, Norway. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Naesset, E (reprint author), Norwegian Univ Life Sci, Dept Ecol & Nat Resource Management, POB 5003, NO-1432 As, Norway. EM erik.naesset@umb.no RI Nelson, Ross/H-8266-2014 NR 35 TC 33 Z9 33 U1 0 U2 24 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 OCT 15 PY 2007 VL 110 IS 3 BP 357 EP 369 DI 10.1016/j.rse.2007.03.004 PG 13 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 210LB UT WOS:000249456600007 ER PT J AU Teillet, PM Fedosejevs, G Thome, KJ Barker, JL AF Teillet, P. M. Fedosejevs, G. Thome, K. J. Barker, John L. TI Impacts of spectral band difference effects on radiometric cross-calibration between satellite sensors in the solar-reflective spectral domain SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE radio calibration; sensor cross-calibration; spectral bands ID IN-FLIGHT CALIBRATION; HIGH-RESOLUTION RADIOMETER; NEAR-INFRARED CHANNELS; VICARIOUS CALIBRATION; ABSOLUTE CALIBRATION; LANDSAT-7 ETM+; TEST-SITE; SURFACE REFLECTANCE; VEGETATION INDEXES; GROUND TARGETS AB In order for quantitative applications to make full use of the ever-increasing number of Earth observation satellite systems, data from the various imaging sensors involved must be on a consistent radiometric scale. This paper reports on an investigation of radiometric calibration errors due to differences in spectral response functions between satellite sensors when attempting cross-calibration based on near-simultaneous imaging of common ground targets in analogous spectral bands, a commonly used post-launch calibration methodology. Twenty Earth observation imaging sensors (including coarser and higher spatial resolution sensors) were considered, using the Landsat solar reflective spectral domain as a framework. Scene content was simulated using spectra for four ground target types (Railroad Valley Playa, snow, sand and rangeland), together with various combinations of atmospheric states and illumination geometries. Results were obtained as a function of ground target type, satellite sensor comparison, spectral region, and scene content. Overall, if spectral band difference effects (SBDEs) are not taken into account, the Railroad Valley Playa site is a "good" ground target for cross calibration between most but not all satellite sensors in most but not all spectral regions investigated. "Good" is defined as SBDEs within +/- 3%. The other three ground target types considered (snow, sand and rangeland) proved to be more sensitive to uncorrected SBDEs than the RVPN site overall. The spectral characteristics of the scene content (solar irradiance, surface reflectance and atmosphere) are examined in detail to clarify why spectral difference effects arise and why they can be significant when comparing different imaging sensor systems. Atmospheric gas absorption features are identified as being the main source of spectral variability in most spectral regions. The paper concludes with recommendations on spectral data and tools that would facilitate cross-calibration between multiple satellite sensors. (c) 2007 Elsevier Inc. All rights reserved. C1 Univ Lethbridge, Dept Phys, Lethbridge, AB T1K 3M4, Canada. Canada Ctr Remote Sensing, Ottawa, ON K1A OY7, Canada. Univ Arizona, Remote Sensing Grp, Ctr Opt Sci, Tucson, AZ 85721 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Teillet, PM (reprint author), Univ Lethbridge, Dept Phys, 4401 Univ Dr W, Lethbridge, AB T1K 3M4, Canada. EM p.teillet@uleth.ca RI Thome, Kurtis/D-7251-2012 NR 66 TC 72 Z9 78 U1 4 U2 38 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 OCT 15 PY 2007 VL 110 IS 3 BP 393 EP 409 DI 10.1016/j.rse.2007.03.003 PG 17 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 210LB UT WOS:000249456600010 ER PT J AU Florescu, M Lee, H Puscasu, I Pralle, M Florescu, L Ting, DZ Dowling, JP AF Florescu, Marian Lee, Hwang Puscasu, Irina Pralle, Martin Florescu, Lucia Ting, David Z. Dowling, Jonathan P. TI Improving solar cell efficiency using photonic band-gap materials SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE photonic band-gap materials; thermophotovoltaics; solar cells ID SPONTANEOUS-EMISSION; CRYSTAL EMISSION; RADIATION; DEMAND; LASER; EDGE AB The potential of using photonic crystal structures for realizing highly efficient and reliable solar-cell devices is presented. We show that due their ability to modify the spectral and angular characteristics of thermal radiation, photonic crystals emerge as one of the leading candidates for frequency- and angular-selective radiating elements in thermophotovoltaic devices. We show that employing photonic crystal-based angle- and frequency-selective absorbers facilitates a strong enhancement of the conversion efficiency of solar cell devices without using concentrators. (c) 2007 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Louisiana State Univ, Hearne Inst Theoret Phys, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Ion Opt Inc, Waltham, MA USA. RP Florescu, M (reprint author), CALTECH, Jet Prop Lab, Mail Stop T1714 106,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Marian.Florescu@jpl.nasa.gov RI Florescu, Marian/E-9009-2010; DOWLING, JONATHAN/L-2749-2013 NR 29 TC 54 Z9 55 U1 0 U2 23 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOL ENERG MAT SOL C JI Sol. Energy Mater. Sol. Cells PD OCT 15 PY 2007 VL 91 IS 17 BP 1599 EP 1610 DI 10.1016/j.solmat.2007.05.001 PG 12 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 215UZ UT WOS:000249835800002 ER PT J AU Mercer, JL Kroger, C Nardi, B Johnson, BJ Chipperfield, MP Wood, SW Nichol, SE Santee, ML Deshler, T AF Mercer, J. L. Kroeger, C. Nardi, B. Johnson, B. J. Chipperfield, M. P. Wood, S. W. Nichol, S. E. Santee, M. L. Deshler, T. TI Comparison of measured and modeled ozone above McMurdo Station, Antarctica, 1989-2003, during austral winter/spring SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHEMICAL-TRANSPORT MODEL; CHEMISTRY-CLIMATE MODELS; 3-DIMENSIONAL MODEL; POLAR VORTEX; STRATOSPHERE CLAMS; CATHODE SOLUTIONS; LAGRANGIAN MODEL; ART.; RESOLUTION; PROFILES AB [ 1] Fifteen years of ozonesonde measurements at McMurdo Station, Antarctica ( 78 degrees S), are used to test the ability of the SLIMCAT off-line 3-D chemical transport model to reproduce Antarctic stratospheric ozone in the period of August-October over many annual cycles. Two versions of SLIMCAT, both previously used in Arctic studies, are used in a detailed quantitative comparison for total column ozone and ozone mixing ratios ( O(3)MR) at the vertical resolution of SLIMCAT. The newer model run, EC, forced by ERA-40 ECMWF meteorological ( re) analyses, uses a general circulation model ( GCM) radiation scheme to derive vertical transport and has improved chemistry and denitrification. The older run, UK, uses UKMO analyses and the MIDRAD scheme. Run EC shows good agreement with measured total column ozone ( within +/- 10%). Run UK has similar agreement except during the annual ozone depletion period when run UK overestimates total column ozone by similar to 20% in many years. Linear regression of O3MR shows run EC is in excellent agreement with measurements, R(2) = 0.89. Run UK does not agree as well at higher altitudes in late winter. Overall, the newer version of SLIMCAT, with improved vertical velocity due to the use of the GCM radiation scheme and improved vertical and temporal resolution due to the use of ERA-40 ECMWF ( re) analyses, does well in reproducing variations in Antarctic ozone concentrations over many annual cycles, indicating SLIMCAT can make useful contributions to chemistry climate models ( CCM). C1 Univ Wyoming, Dept Atmospher Sci, Laramie, WY 82071 USA. Inst Geol & Nucl Sci, Lower Hutt, New Zealand. Univ Corp Atmospher Res, Boulder, CO USA. NOAA, Earth Syst Res Lab, Global Monitoring Div, Boulder, CO USA. Univ Leeds, Sch Earth Environm, Leeds, W Yorkshire, England. New Zealand Natl Inst Water & Atmospher Res Ltd, Wellington, New Zealand. Jet Propuls Lab, Pasadena, CA USA. RP Mercer, JL (reprint author), Univ Wyoming, Dept Atmospher Sci, Laramie, WY 82071 USA. EM mercer@uwyo.edu RI Chipperfield, Martyn/H-6359-2013 OI Chipperfield, Martyn/0000-0002-6803-4149 NR 49 TC 3 Z9 4 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-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 12 PY 2007 VL 112 IS D19 AR D19307 DI 10.1029/2006JD007982 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 221HY UT WOS:000250219200001 ER PT J AU Roush, TL Esposito, F Rossman, GR Colangeli, L AF Roush, Ted L. Esposito, Francesca Rossman, George R. Colangeli, Luigi TI Estimated optical constants of gypsum in the regions of weak absorptions: Application of scattering theories and comparisons to independent measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID BIDIRECTIONAL REFLECTANCE SPECTROSCOPY; MU-M; OMEGA/MARS EXPRESS; MERIDIANI-PLANUM; QUANTITATIVE-ANALYSIS; ICE; MINERALS; SULFATE; SPECTROMETER; PARTICLES AB [1] Diffuse reflectance spectra of multiple grain size fractions are used to estimate the optical constants of gypsum over the 0.4-15 mu m wavelength region. Two independent scattering theories are used to iteratively determine the imaginary index of refraction from the measured reflectance. We compare the results of these two with each other and with imaginary indices of gypsum reported in the literature. We find that the scattering theory results are more sensitive in the infrared to weak spectral features that are clearly distinguished in the diffuse reflectance spectra. However, we find the scattering results provide a poor determination of the optical constants in the regions of relatively strong absorptions. At visible and near-infrared wavelengths we provide a comparison to the results obtained from analysis of the diffuse reflectance to results obtained from direct transmission measurements of several gypsum crystals having different sample thicknesses. We find the simplest models of the transmission reproduce the observed spectra. The different sample thicknesses for the transmission measurements and different grain sizes in the scattering theories allow evaluation of the imaginary index of refraction over a wide range of values. We find the imaginary index of refraction determined from scattering theories is in remarkable agreement with those obtained from transmission spectra. Different models of the reflectance and transmittance have associated strengths and weaknesses, and we conclude that combining these models provides a more accurate determination of the optical constants of a material when compared to using each separately. We combine the resulting real and imaginary indices of refraction with those reported at infrared wavelengths to provide values covering visual, near-infrared, and infrared wavelengths (0.4-333 mu m, 25000-30 cm(-1)). C1 NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Planetary Syst Branch, Moffett Field, CA 94035 USA. Osserv Astron Capodimonte, INAF, I-80131 Naples, Italy. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Roush, TL (reprint author), NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Planetary Syst Branch, Moffett Field, CA 94035 USA. EM troush@mail.arc.nasa.gov OI Esposito, Francesca/0000-0001-9962-1648; Rossman, George/0000-0002-4571-6884 NR 43 TC 17 Z9 17 U1 0 U2 7 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 OCT 12 PY 2007 VL 112 IS E10 AR E10003 DI 10.1029/2007JE002920 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 221IO UT WOS:000250220800001 ER PT J AU Khazanov, GV Gamayunov, KV AF Khazanov, G. V. Gamayunov, K. V. TI Effect of electromagnetic ion cyclotron wave normal angle distribution on relativistic electron scattering in outer radiation belt SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PITCH-ANGLE; DIFFUSION-COEFFICIENTS; GEOMAGNETIC STORMS; SYNCHRONOUS ORBIT; MAGNETIC STORM; EMIC WAVES; PRECIPITATION; MAGNETOSPHERE; POLARIZATION; PLASMAPAUSE AB We present the equatorial and bounce-averaged pitch angle diffusion coefficients for the scattering relativistic electrons by He+-mode electromagnetic ion cyclotron waves. Both the model ( prescribed) and self-consistent distributions over the wave normal angle are considered. The main results of our calculation can be summarized as follows: First, in comparison with field-aligned waves, intermediate and highly oblique waves decrease the bounce-averaged scattering rate near the edge of the loss cone by up to orders of magnitude if the electron energy does not exceed a threshold (similar to 2-5 MeV) depending on specified plasma and/or wave parameters. Second, for greater electron energies, oblique waves operating the vertical bar n vertical bar > 1 resonances are more effective and provide the same bounce-averaged diffusion rate near the edge of the loss cone as field-aligned waves do. C1 NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. RP Khazanov, GV (reprint author), NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Natl Space Sci & Technol Ctr, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM george.khazanov@msfc.nasa.gov; konstantin.gamayunov@msfc.nasa.gov RI Gamayunov, Konstantin/A-8505-2009 OI Gamayunov, Konstantin/0000-0002-8768-8527 NR 33 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 12 PY 2007 VL 112 IS A10 AR A10209 DI 10.1029/2007JA012282 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 221IU UT WOS:000250221400003 ER PT J AU Kuznetsova, MM Hesse, M Rastatter, L Taktakishvili, A Toth, G De Zeeuw, DL Ridley, A Gombosi, TI AF Kuznetsova, M. M. Hesse, M. Rastaetter, L. Taktakishvili, A. Toth, G. De Zeeuw, D. L. Ridley, A. Gombosi, T. I. TI Multiscale modeling of magnetospheric reconnection SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID COLLISIONLESS MAGNETIC RECONNECTION; GLOBAL MAGNETOHYDRODYNAMIC SIMULATIONS; ITERATIVE MAPPING PROCEDURE; HYBRID-DRIFT INSTABILITY; LAW BOUNDARY-CONDITION; GUIDE-FIELD; PARTICLE SIMULATIONS; PERIODIC SUBSTORMS; PRESSURE TENSOR; MHD SIMULATION AB In our efforts to bridge the gap between small-scale kinetic modeling and global simulations, we introduced an approach that allows to quantify the interaction between large-scale global magnetospheric dynamics and microphysical processes in diffusion regions near reconnection sites. We use the global MHD code BATS-R-US and replace an ad hoc anomalous resistivity often employed by global MHD models with a physically motivated dissipation model. The primary kinetic mechanism controlling the dissipation in the diffusion region in the vicinity of the reconnection site is incorporated into the MHD description in terms of nongyrotropic corrections to the induction equation. We developed an algorithm to search for reconnection sites in north-south symmetric magnetotail. Spatial scales of the diffusion region and magnitude of the reconnection electric field are calculated consistently using local MHD plasma and field parameters. The locations of the reconnection sites are constantly updated during the simulations. To clarify the role of nongyrotropic effects in the diffusion region on the global magnetospheric dynamics, we perform simulations with steady southward interplanetary magnetic field driving of the magnetosphere. Ideal MHD simulations with magnetic reconnection supported by numerical resistivity often produce quasi-steady configuration with almost stationary near-Earth neutral line (NENL). Simulations with nongyrotropic corrections demonstrate dynamic quasi-periodic response to the steady driving conditions. Fast magnetotail reconnection supported by nongyrotropic effects results in tailward retreat of the reconnection site with average speed of the order of 100 km/s followed by a formation of a new NENL in the near-Earth thin current sheet. This approach allowed to model for the first time loading/unloading cycle frequently observed during extended periods of steady low-mach-number solar wind with southward interplanetary magnetic field. C1 NASA, Goddard Space Flight Ctr, Space Weather Lab, Greenbelt, MD 20771 USA. Univ Michigan, Ctr Space Environm Modeling, Ann Arbor, MI 48109 USA. RP Kuznetsova, MM (reprint author), NASA, Goddard Space Flight Ctr, Space Weather Lab, Code 674,Bld 21,Rm 230, Greenbelt, MD 20771 USA. EM maria.m.kuznetsova@nasa.gov RI Ridley, Aaron/F-3943-2011; Gombosi, Tamas/G-4238-2011; De Zeeuw, Darren/F-3667-2011; Hesse, Michael/D-2031-2012; Rastaetter, Lutz/D-4715-2012; Kuznetsova, Maria/F-6840-2012; Toth, Gabor/B-7977-2013; NASA MMS, Science Team/J-5393-2013 OI Ridley, Aaron/0000-0001-6933-8534; Gombosi, Tamas/0000-0001-9360-4951; Rastaetter, Lutz/0000-0002-7343-4147; Toth, Gabor/0000-0002-5654-9823; NASA MMS, Science Team/0000-0002-9504-5214 NR 56 TC 50 Z9 50 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 OCT 12 PY 2007 VL 112 IS A10 AR A10210 DI 10.1029/2007JA012316 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 221IU UT WOS:000250221400006 ER PT J AU Lepping, RP Wu, CC AF Lepping, R. P. Wu, C.-C. TI On the variation of interplanetary magnetic cloud type through solar cycle 23: Wind events SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GEOMAGNETIC STORMS; SOLAR-WIND; CYCLE; EVOLUTION; CMES AB This statistical study examines the change in interplanetary magnetic cloud ( MC) type, based on Wind observations of 100 MCs, taken during solar cycle 23 and split into three intervals: the minimum and rising phase of the cycle (over the years 1995-1998), the maximum phase (1999-2001), and the declining phase (2002 to early 2006). MC type refers to the profile of the latitude ( or B-Z, in geocentric solar ecliptic (GSE) coordinates) of the magnetic field within the MC, such as N-to-S (i. e., north-to-south from start to end), S-to-N, all S, almost all S, and so forth, with 10 categories in all. One of the main findings is that the strictly S-to-N events were very prevalent early in the cycle ( i. e., 33% for the first phase) and tended to decrease in number as the cycle proceeded and that the strictly N-to-S cases had very low frequency of occurrence early in the cycle ( i. e., 8% for the first phase) but tended to increase in number (22%) toward the end of the cycle, equal to the number of S-to-N events in that phase. When all S-to-N and N-to-S types for the full cycle are considered, the former clearly dominated over the latter by 1.4-to-1. C1 NASA, Goddard Space Flight Ctr, Space Weather Lab, Greenbelt, MD 20771 USA. Univ Alabama, Huntsville, AL 35899 USA. RP Lepping, RP (reprint author), NASA, Goddard Space Flight Ctr, Space Weather Lab, Greenbelt, MD 20771 USA. EM ronald.p.lepping@nasa.gov NR 29 TC 11 Z9 12 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 OCT 12 PY 2007 VL 112 IS A10 AR A10103 DI 10.1029/2006JA012140 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 221IU UT WOS:000250221400001 ER PT J AU Zhang, J Richardson, IG Webb, DF Gopalswamy, N Huttunen, E Kasper, JC Nitta, NV Poomvises, W Thompson, BJ Wu, CC Yashiro, S Zhukov, AN AF Zhang, J. Richardson, I. G. Webb, D. F. Gopalswamy, N. Huttunen, E. Kasper, J. C. Nitta, N. V. Poomvises, W. Thompson, B. J. Wu, C.-C. Yashiro, S. Zhukov, A. N. TI Solar and interplanetary sources of major geomagnetic storms (Dst <=-100 nT) during 1996-2005 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; MAGNETIC CLOUDS; SEMIANNUAL VARIATION; EARTH; WIND; SIGNATURES; SOLAR-CYCLE-23; MAXIMUM; MISSION; IMAGER AB We present the results of an investigation of the sequence of events from the Sun to the Earth that ultimately led to the 88 major geomagnetic storms ( defined by minimum Dst <= - 100 nT) that occurred during 1996-2005. The results are achieved through cooperative efforts that originated at the Living with a Star (LWS) Coordinated Data-Analysis Workshop ( CDAW) held at George Mason University in March 2005. On the basis of careful examination of the complete array of solar and in situ solar wind observations, we have identified and characterized, for each major geomagnetic storm, the overall solar-interplanetary (solar-IP) source type, the time, velocity, and angular width of the source coronal mass ejection (CME), the type and heliographic location of the solar source region, the structure of the transient solar wind flow with the storm-driving component specified, the arrival time of shock/disturbance, and the start and ending times of the corresponding IP CME (ICME). The storm-driving component, which possesses a prolonged and enhanced southward magnetic field (Bs), may be an ICME, the sheath of shocked plasma (SH) upstream of an ICME, a corotating interaction region (CIR), or a combination of these structures. We classify the Solar-IP sources into three broad types: ( 1) S-type, in which the storm is associated with a single ICME and a single CME at the Sun; ( 2) M-type, in which the storm is associated with a complex solar wind flow produced by multiple interacting ICMEs arising from multiple halo CMEs launched from the Sun in a short period; ( 3) C-type, in which the storm is associated with a CIR formed at the leading edge of a high-speed stream originating from a solar coronal hole ( CH). For the 88 major storms, the S-type, M-type, and C-type events number 53 (60%), 24 (27%), and 11 (13%), respectively. For the 85 events for which the surface source regions could be investigated, 54 (63%) of the storms originated in solar active regions, 11 ( 13%) in quiet Sun regions associated with quiescent filaments or filament channels, and 11 ( 13%) were associated with coronal holes. Remarkably, nine (11%) CME-driven events showed no sign of eruptive features on the surface or in the low corona ( e. g., no flare, no coronal dimming, and no loop arcade, etc.), even though all the available solar observations in a suitable time period were carefully examined. Thus while it is generally true that a major geomagnetic storm is more likely to be driven by a frontside fast halo CME associated with a major flare, our study indicates a broad distribution of source properties. The implications of the results for space weather forecasting are briefly discussed. C1 George Mason Univ, Dept Computat & Data Sci, Fairfax, VA 22030 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Boston Coll, Inst Sci Res, Chestnut Hill, MA 02467 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. Lockheed Martin Solar & Astrophys Lab, Palo Alto, CA 94304 USA. Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. Catholic Univ Amer, Washington, DC 20064 USA. Observ Royal Belgique, B-1180 Brussels, Belgium. Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow, Russia. RP Zhang, J (reprint author), George Mason Univ, Dept Computat & Data Sci, 4400 Univ Dr,MSN 6A2, Fairfax, VA 22030 USA. EM jzhang7@gmu.edu; ian.richardson@gsfc.nasa.gov; webb.ctr@hanscom.af.mil; gopals@ssedmail.gsfc.nasa.gov; huttunen@ssl.berkeley.edu; jck@mit.edu; nitta@lmsal.com; wpoomvis@gmu.edu; barbara.j.thompson@nasa.gov; wuc@cspar.uah.edu; yashiro@ssedmail.gsfc.nasa.gov; andrei.zhukov@oma.be RI Gopalswamy, Nat/D-3659-2012; Kilpua, Emilia/G-8994-2012; Kasper, Justin/D-1152-2010; Thompson, Barbara/C-9429-2012; OI Kasper, Justin/0000-0002-7077-930X; Richardson, Ian/0000-0002-3855-3634 NR 72 TC 234 Z9 245 U1 0 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 12 PY 2007 VL 112 IS A10 AR A10102 DI 10.1029/2007JA012321 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 221IU UT WOS:000250221400007 ER PT J AU Gaidos, E Haghighipour, N Agol, E Latham, D Raymond, S Rayner, J AF Gaidos, Eric Haghighipour, Nader Agol, Eric Latham, David Raymond, Sean Rayner, John TI New worlds on the horizon: Earth-sized planets close to other stars SO SCIENCE LA English DT Review ID NEPTUNE-MASS PLANETS; M-CIRCLE-PLUS; TERRESTRIAL PLANETS; HABITABLE ZONES; SUPER-EARTHS; MIGRATION; SYSTEM; DISKS; PROTOPLANET; TRANSITS AB The search for habitable planets like Earth around other stars fulfills an ancient imperative to understand our origins and place in the cosmos. The past decade has seen the discovery of hundreds of planets, but nearly all are gas giants like Jupiter and Saturn. Recent advances in instrumentation and new missions are extending searches to planets the size of Earth but closer to their host stars. There are several possible ways such planets could form, and future observations will soon test those theories. Many of these planets we discover may be quite unlike Earth in their surface temperature and composition, but their study will nonetheless inform us about the process of planet formation and the frequency of Earth-like planets around other stars. C1 Univ Hawaii Manoa, Dept Geol & Geophys, Honolulu, HI 96822 USA. NASA, Ames Res Ctr, Astrobiol Inst, Moffett Field, CA 94035 USA. Univ Hawaii Manoa, Inst Astron, Honolulu, HI 96822 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. RP Gaidos, E (reprint author), Univ Hawaii Manoa, Dept Geol & Geophys, Honolulu, HI 96822 USA. EM gaidos@hawaii.edu RI Agol, Eric/B-8775-2013 OI Agol, Eric/0000-0002-0802-9145 NR 39 TC 25 Z9 25 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 OCT 12 PY 2007 VL 318 IS 5848 BP 210 EP 213 DI 10.1126/science.1144358 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100027 PM 17932279 ER PT J AU McComas, DJ Allegrini, F Bagenal, F Crary, F Ebert, RW Elliott, H Stern, A Valek, P AF McComas, D. J. Allegrini, F. Bagenal, F. Crary, F. Ebert, R. W. Elliott, H. Stern, A. Valek, P. TI Diverse plasma Populations and structures in Jupiter's magnetotail SO SCIENCE LA English DT Article ID HOT PLASMA; MAGNETOSPHERE AB Jupiter's magnetotail is the largest cohesive structure in the solar system and marks the loss of vast numbers of heavy ions from the Jupiter system. The New Horizons spacecraft traversed the magnetotail to distances exceeding 2500 jovian radii (R-J) and revealed a remarkable diversity of plasma populations and structures throughout its length. Ions evolve from a hot plasma disk distribution at similar to 100 R-J to slower, persistent flows down the tail that become increasingly variable in flux and mean energy. The plasma is highly structured-exhibiting sharp breaks, smooth variations, and apparent plasmoids-and contains ions from both Io and Jupiter's ionosphere with intense bursts of H+ and H-3(+). Quasi-periodic changes were seen in flux at similar to 450 and similar to 1500 R-J with a 10-hour period. Other variations in flow speed at similar to 600 to 1000 R-J with a 3- to 4-day period may be attributable to plasmoids moving down the tail. C1 SW Res Inst, San Antonio, TX 78238 USA. Univ Texas, Dept Phys & Astron, San Antonio, TX 78249 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA Headquarters, Sci Mission Directorate, Washington, DC 20546 USA. RP McComas, DJ (reprint author), SW Res Inst, 6220 Culebra Rd, San Antonio, TX 78238 USA. EM dmccomas@swri.edu OI Valek, Philip/0000-0002-2318-8750 NR 18 TC 50 Z9 50 U1 0 U2 4 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 OCT 12 PY 2007 VL 318 IS 5848 BP 217 EP 220 DI 10.1126/science.1147393 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100030 PM 17932282 ER PT J AU McNutt, RL Haggerty, DK Hill, ME Krimigis, SM Livi, S Ho, GC Gurnee, RS Mauk, BH Mitchell, DG Roelof, EC McComas, DJ Bagenal, F Elliott, HA Brown, LE Kusterer, M Vandegriff, J Stern, SA Weaver, HA Spencer, JR Moore, JM AF McNutt, R. L., Jr. Haggerty, D. K. Hill, M. E. Krimigis, S. M. Livi, S. Ho, G. C. Gurnee, R. S. Mauk, B. H. Mitchell, D. G. Roelof, E. C. McComas, D. J. Bagenal, F. Elliott, H. A. Brown, L. E. Kusterer, M. Vandegriff, J. Stern, S. A. Weaver, H. A. Spencer, J. R. Moore, J. M. TI Energetic particles in the Jovian magnetotail SO SCIENCE LA English DT Article ID SPECTRAL-ANALYSIS; TIME-SERIES; MAGNETOSPHERE; JUPITER; UPSTREAM; BURSTS; EVENTS; TAIL; IONS AB When the solar wind hits Jupiter's magnetic field, it creates a long magnetotail trailing behind the planet that channels material out of the Jupiter system. The New Horizons spacecraft traversed the length of the jovian magnetotail to >2500 jovian radii (R-J; 1 R-J = 71,400 kilometers), observing a high-temperature, multispecies population of energetic particles. Velocity dispersions, anisotropies, and compositional variation seen in the deep-tail (greater than or similar to 500 R-J) with a similar to 3-day periodicity are similar to variations seen closer to Jupiter in Galileo data. The signatures suggest plasma streaming away from the planet and injection sites in the near-tail region (similar to 200 to 400 R-J) that could be related to magnetic reconnection events. The tail structure remains coherent at least until it reaches the magnetosheath at 1655 R-J. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Acad Athens, Athens 10679, Greece. SW Res Inst, San Antonio, TX 78228 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA Headquarters, Washington, DC 20546 USA. SW Res Inst, Boulder, CO 80302 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP McNutt, RL (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM ralph.mcnutt@jhuapl.edu RI McNutt, Ralph/E-8006-2010; Ho, George/G-3650-2015; Weaver, Harold/D-9188-2016; Hill, Matthew/H-4312-2016; Mauk, Barry/E-8420-2017 OI McNutt, Ralph/0000-0002-4722-9166; Ho, George/0000-0003-1093-2066; Hill, Matthew/0000-0002-5674-4936; Mauk, Barry/0000-0001-9789-3797 NR 26 TC 32 Z9 32 U1 0 U2 6 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 OCT 12 PY 2007 VL 318 IS 5848 BP 220 EP 222 DI 10.1126/science.1148025 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100031 PM 17932283 ER PT J AU Reuter, DC Simon-Miller, AA Lunsford, A Baines, KH Cheng, AF Jennings, DE Olkin, CB Spencer, JR Stern, SA Weaver, HA Young, LA AF Reuter, D. C. Simon-Miller, A. A. Lunsford, A. Baines, K. H. Cheng, A. F. Jennings, D. E. Olkin, C. B. Spencer, J. R. Stern, S. A. Weaver, H. A. Young, L. A. TI Jupiter cloud composition, stratification, convection, and wave motion: A view from new horizons SO SCIENCE LA English DT Article ID ATMOSPHERE; IDENTIFICATION; SATELLITES; PROBE AB Several observations of Jupiter's atmosphere made by instruments on the New Horizons spacecraft have implications for the stability and dynamics of Jupiter's weather layer. Mesoscale waves, first seen by Voyager, have been observed at a spatial resolution of 11 to 45 kilometers. These waves have a 300-kilometer wavelength and phase velocities greater than the local zonal flow by 100 meters per second, much higher than predicted by models. Additionally, infrared spectral measurements over five successive Jupiter rotations at spatial resolutions of 200 to 140 kilometers have shown the development of transient ammonia ice clouds (lifetimes of 40 hours or less) in regions of strong atmospheric upwelling. Both of these phenomena serve as probes of atmospheric dynamics below the visible cloud tops. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA Headquarters, Sci Mission Directorate, Washington, DC 20546 USA. SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. RP Reuter, DC (reprint author), NASA, Goddard Space Flight Ctr, Code 693, Greenbelt, MD 20771 USA. EM dennis.c.reuter@nasa.gov RI Jennings, Donald/D-7978-2012; Simon, Amy/C-8020-2012; Weaver, Harold/D-9188-2016 OI Simon, Amy/0000-0003-4641-6186; NR 14 TC 25 Z9 27 U1 0 U2 13 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 OCT 12 PY 2007 VL 318 IS 5848 BP 223 EP 225 DI 10.1126/science.1147618 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100032 PM 17932284 ER PT J AU Baines, KH Simon-Miller, AA Orton, GS Weaver, HA Lunsford, A Momary, TW Spencer, J Cheng, AF Reuter, DC Jennings, DE Gladstone, GR Moore, J Stern, SA Young, LA Throop, H Yanamandra-Fisher, P Fisher, BM Hora, J Ressler, ME AF Baines, Kevin H. Simon-Miller, Amy A. Orton, Glenn S. Weaver, Harold A. Lunsford, Allen Momary, Thomas W. Spencer, John Cheng, Andrew F. Reuter, Dennis C. Jennings, Donald E. Gladstone, G. R. Moore, Jeffrey Stern, S. Alan Young, Leslie A. Throop, Henry Yanamandra-Fisher, Padma Fisher, Brendan M. Hora, Joseph Ressler, Michael E. TI Polar lightning and decadal-scale cloud variability on Jupiter SO SCIENCE LA English DT Article ID RADIO ASTRONOMY OBSERVATIONS; MEAN ZONAL FLOW; SPATIAL-DISTRIBUTION; GALILEO IMAGES; ATMOSPHERE; VOYAGER-1; SATURN AB Although lightning has been seen on other planets, including Jupiter, polar lightning has been known only on Earth. Optical observations from the New Horizons spacecraft have identified lightning at high latitudes above Jupiter up to 80 degrees N and 74 degrees S. Lightning rates and optical powers were similar at each pole, and the mean optical flux is comparable to that at nonpolar latitudes, which is consistent with the notion that internal heat is the main driver of convection. Both near-infrared and ground-based 5-micrometer thermal imagery reveal that cloud cover has thinned substantially since the 2000 Cassini flyby, particularly in the turbulent wake of the Great Red Spot and in the southern half of the equatorial region, demonstrating that vertical dynamical processes are time-varying on seasonal scales at mid-and low latitudes on Jupiter. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. SW Res Inst, Boulder, CO 80302 USA. SW Res Inst, San Antonio, TX 78238 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA Headquarters, Sci Mission Directorate, Washington, DC 20546 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Baines, KH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Jennings, Donald/D-7978-2012; Simon, Amy/C-8020-2012; Weaver, Harold/D-9188-2016; OI Simon, Amy/0000-0003-4641-6186; Hora, Joseph/0000-0002-5599-4650 NR 30 TC 26 Z9 26 U1 0 U2 4 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 OCT 12 PY 2007 VL 318 IS 5848 BP 226 EP 229 DI 10.1126/science.1147912 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100033 PM 17932285 ER PT J AU Gladstone, GR Stern, SA Slater, DC Versteeg, M Davis, MW Retherford, KD Young, LA Steffl, AJ Throop, H Parker, JW Weaver, HA Cheng, AF Orton, GS Clarke, JT Nichols, JD AF Gladstone, G. Randall Stern, S. Alan Slater, David C. Versteeg, Maarten Davis, Michael W. Retherford, Kurt D. Young, Leslie A. Steffl, Andrew J. Throop, Henry Parker, Joel Wm. Weaver, Harold A. Cheng, Andrew F. Orton, Glenn S. Clarke, John T. Nichols, Jonathan D. TI Jupiter's nightside airglow and aurora SO SCIENCE LA English DT Article ID IO FLUX TUBE; JOVIAN AURORA; EMISSIONS; FOOTPRINT; MISSION AB Observations of Jupiter's nightside airglow (nightglow) and aurora obtained during the flyby of the New Horizons spacecraft show an unexpected lack of ultraviolet nightglow emissions, in contrast to the case during the Voyager flybys in 1979. The flux and average energy of precipitating electrons generally decrease with increasing local time across the nightside, consistent with a possible source region along the dusk flank of Jupiter's magnetosphere. Visible emissions associated with the interaction of Jupiter and its satellite Io extend to a surprisingly high altitude, indicating localized low-energy electron precipitation. These results indicate that the interaction between Jupiter's upper atmosphere and near-space environment is variable and poorly understood; extensive observations of the day side are no guide to what goes on at night. C1 SW Res Inst, San Antonio, TX 78238 USA. NASA Headquarters, Washington, DC 20546 USA. SW Res Inst, Boulder, CO 80302 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Boston Univ, Boston, MA 02215 USA. RP Gladstone, GR (reprint author), SW Res Inst, San Antonio, TX 78238 USA. EM rgladstone@swri.edu RI Nichols, Jonathan/F-5764-2010; Clarke, John/C-8644-2013; Weaver, Harold/D-9188-2016 OI Nichols, Jonathan/0000-0002-8004-6409; NR 29 TC 12 Z9 12 U1 0 U2 4 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 OCT 12 PY 2007 VL 318 IS 5848 BP 229 EP 231 DI 10.1126/science.1147613 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100034 PM 17932286 ER PT J AU Showalter, MR Cheng, AF Weaver, HA Stern, SA Spencer, JR Throop, HB Birath, EM Rose, D Moore, JM AF Showalter, Mark R. Cheng, Andrew F. Weaver, Harold A. Stern, S. Alan Spencer, John R. Throop, Henry B. Birath, Emma M. Rose, Debi Moore, Jeffrey M. TI Clump detections and limits on moons in Jupiter's ring system SO SCIENCE LA English DT Article ID SATURNS F-RING; CASSINI; GALILEO; SATELLITES; ACCRETION; ORBITS AB The dusty jovian ring system must be replenished continuously from embedded source bodies. The New Horizons spacecraft has performed a comprehensive search for kilometer-sized moons within the system, which might have revealed the larger members of this population. No new moons were found, however, indicating a sharp cutoff in the population of jovian bodies smaller than 8-kilometer-radius Adrastea. However, the search revealed two families of clumps in the main ring: one close pair and one cluster of three to five. All orbit within a brighter ringlet just interior to Adrastea. Their properties are very different from those of the few other clumpy rings known; the origin and nonrandom distribution of these features remain unexplained, but resonant confinement by Metis may play a role. C1 Search Extraterr Intelligence Inst, Mountain View, CA 94043 USA. NASA Headquarters, Washington, DC 20546 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. SW Res Inst, Boulder, CO 80302 USA. Synthsys D, Superior, CO 80027 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Showalter, MR (reprint author), Search Extraterr Intelligence Inst, Mountain View, CA 94043 USA. EM mshowalter@seti.org RI Weaver, Harold/D-9188-2016 NR 22 TC 9 Z9 9 U1 1 U2 2 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 OCT 12 PY 2007 VL 318 IS 5848 BP 232 EP 234 DI 10.1126/science.1147647 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100035 PM 17932287 ER PT J AU Grundy, WM Buratti, BJ Cheng, AF Emery, JP Lunsford, A McKinnon, WB Moore, JM Newman, SF Olkin, CB Reuter, DC Schenk, PM Spencer, JR Stern, SA Throop, HB Weaver, HA AF Grundy, W. M. Buratti, B. J. Cheng, A. F. Emery, J. P. Lunsford, A. McKinnon, W. B. Moore, J. M. Newman, S. F. Olkin, C. B. Reuter, D. C. Schenk, P. M. Spencer, J. R. Stern, S. A. Throop, H. B. Weaver, H. A. CA New Horizons Team TI New horizons mapping of Europa and Ganymede SO SCIENCE LA English DT Article ID HYDRATED SALT MINERALS; SULFURIC-ACID; VOYAGER PHOTOMETRY; POLAR WANDER; ICE SHELL; SURFACE; OCEAN; SPECTROMETER AB The New Horizons spacecraft observed Jupiter's icy satellites Europa and Ganymede during its flyby in February and March 2007 at visible and infrared wavelengths. Infrared spectral images map H2O ice absorption and hydrated contaminants, bolstering the case for an exogenous source of Europa's "non-ice" surface material and filling large gaps in compositional maps of Ganymede's Jupiter-facing hemisphere. Visual wavelength images of Europa extend knowledge of its global pattern of arcuate troughs and show that its surface scatters light more isotropically than other icy satellites. C1 Lowell Observ, Flagstaff, AZ 86001 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA, Ames Res Ctr, SETI Inst, Mountain View, CA 94043 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. Lunar & Planetary Inst, Houston, TX 77058 USA. NASA Headquarters, Sci Mission Directorate, Washington, DC 20546 USA. RP Grundy, WM (reprint author), Lowell Observ, 1400 W Mars Hill Rd, Flagstaff, AZ 86001 USA. EM w.grundy@lowell.edu RI Weaver, Harold/D-9188-2016 NR 27 TC 24 Z9 25 U1 1 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 OCT 12 PY 2007 VL 318 IS 5848 BP 234 EP 237 DI 10.1126/science.1147623 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100036 PM 17932288 ER PT J AU Retherford, KD Spencer, JR Stern, SA Saur, J Strobel, DF Steffl, AJ Gladstone, GR Weaver, HA Cheng, AF Parker, JW Slater, DC Versteeg, MH Davis, MW Bagenal, F Throop, HB Lopes, RMC Reuter, DC Lunsford, A Conard, SJ Young, LA Moore, JM AF Retherford, K. D. Spencer, J. R. Stern, S. A. Saur, J. Strobel, D. F. Steffl, A. J. Gladstone, G. R. Weaver, H. A. Cheng, A. F. Parker, J. Wm. Slater, D. C. Versteeg, M. H. Davis, M. W. Bagenal, F. Throop, H. B. Lopes, R. M. C. Reuter, D. C. Lunsford, A. Conard, S. J. Young, L. A. Moore, J. M. TI Io's atmospheric response to eclipse: UV Aurorae observations SO SCIENCE LA English DT Article ID SO2; MAGNETOSPHERE; SPECTROSCOPY; SUBLIMATION; MORPHOLOGY; EMISSIONS AB The New Horizons (NH) spacecraft observed Io's aurora in eclipse on four occasions during spring 2007. NH Alice ultraviolet spectroscopy and concurrent Hubble Space Telescope ultraviolet imaging in eclipse investigate the relative contribution of volcanoes to Io's atmosphere and its interaction with Jupiter's magnetosphere. Auroral brightness and morphology variations after eclipse ingress and egress reveal changes in the relative contribution of sublimation and volcanic sources to the atmosphere. Brightnesses viewed at different geometries are best explained by a dramatic difference between the dayside and nightside atmospheric density. Far-ultraviolet aurora morphology reveals the influence of plumes on Io's electrodynamic interaction with Jupiter's magnetosphere. Comparisons to detailed simulations of Io's aurora indicate that volcanoes supply 1 to 3% of the dayside atmosphere. C1 SW Res Inst, San Antonio, TX 78228 USA. SW Res Inst, Boulder, CO 80302 USA. NASA Headquarters, Washington, DC 20546 USA. Univ Cologne, D-50923 Cologne, Germany. Johns Hopkins Univ, Baltimore, MD 21218 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Colorado, Boulder, CO 80302 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Retherford, KD (reprint author), SW Res Inst, 6220 Culebra Rd, San Antonio, TX 78228 USA. EM KRetherford@swri.edu RI Lopes, Rosaly/D-1608-2016; Weaver, Harold/D-9188-2016 OI Lopes, Rosaly/0000-0002-7928-3167; NR 29 TC 22 Z9 22 U1 1 U2 4 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 OCT 12 PY 2007 VL 318 IS 5848 BP 237 EP 240 DI 10.1126/science.1147594 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100037 PM 17932289 ER PT J AU Spencer, JR Stern, SA Cheng, AF Weaver, HA Reuter, DC Retherford, K Lunsford, A Moore, JM Abramov, O Lopes, RMC Perry, JE Kamp, L Showalter, M Jessup, KL Marchis, F Schenk, PM Dumas, C AF Spencer, J. R. Stern, S. A. Cheng, A. F. Weaver, H. A. Reuter, D. C. Retherford, K. Lunsford, A. Moore, J. M. Abramov, O. Lopes, R. M. C. Perry, J. E. Kamp, L. Showalter, M. Jessup, K. L. Marchis, F. Schenk, P. M. Dumas, C. TI Io volcanism seen by New Horizons: A major eruption of the Tvashtar volcano SO SCIENCE LA English DT Article ID SILICATE VOLCANISM; GALILEO SSI; PLUMES; PELE AB Jupiter's moon Io is known to host active volcanoes. In February and March 2007, the New Horizons spacecraft obtained a global snapshot of Io's volcanism. A 350-kilometer- high volcanic plume was seen to emanate from the Tvashtar volcano (62 degrees N, 122 degrees W), and its motion was observed. The plume's morphology and dynamics support nonballistic models of large Io plumes and also suggest that most visible plume particles condensed within the plume rather than being ejected from the source. In images taken in Jupiter eclipse, nonthermal visible-wavelength emission was seen from individual volcanoes near Io's sub-Jupiter and anti-Jupiter points. Near-infrared emission from the brightest volcanoes indicates minimum magma temperatures in the 1150- to 1335-kelvin range, consistent with basaltic composition. C1 SW Res Inst, Boulder, CO 80302 USA. NASA Headquarters, Washington, DC 20546 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. SW Res Inst, San Antonio, TX 78228 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Search Extraterr Intelligence Inst, Mountain View, CA 94043 USA. Lunar & Planetary Inst, Houston, TX 77058 USA. European So Observ, Santiago 19, Chile. RP Spencer, JR (reprint author), SW Res Inst, 1050 Walnut St,Suite 300, Boulder, CO 80302 USA. EM spencer@boulder.swri.edu RI Marchis, Franck/H-3971-2012; Lopes, Rosaly/D-1608-2016; Weaver, Harold/D-9188-2016 OI Lopes, Rosaly/0000-0002-7928-3167; NR 20 TC 51 Z9 51 U1 0 U2 7 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 OCT 12 PY 2007 VL 318 IS 5848 BP 240 EP 243 DI 10.1126/science.1147621 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 219LG UT WOS:000250086100038 PM 17932290 ER PT J AU Perovich, DK Light, B Eicken, H Jones, KF Runciman, K Nghiem, SV AF Perovich, Donald K. Light, Bonnie Eicken, Hajo Jones, Kathleen F. Runciman, Kay Nghiem, Son V. TI Increasing solar heating of the Arctic Ocean and adjacent seas, 1979-2005: Attribution and role in the ice-albedo feedback SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE; SUMMER; ALGORITHM AB [1] Over the past few decades the Arctic sea ice cover has decreased in areal extent. This has altered the solar radiation forcing on the Arctic atmosphere-ice-ocean system by decreasing the surface albedo and allowing more solar heating of the upper ocean. This study addresses how the amount of solar energy absorbed in areas of open water in the Arctic Basin has varied spatially and temporally over the past few decades. A synthetic approach was taken, combining satellite-derived ice concentrations, incident irradiances determined from reanalysis products, and field observations of ocean albedo over the Arctic Ocean and the adjacent seas. Results indicate an increase in the solar energy deposited in the upper ocean over the past few decades in 89% of the region studied. The largest increases in total yearly solar heat input, as much as 4% per year, occurred in the Chukchi Sea and adjacent areas. C1 US Army Engn Res & Dev Ctr, Cold Regions Res & Engn Lab, Hanover, NH USA. Polar Sci Ctr, Appl Phys Lab, Seattle, WA USA. Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK USA. CALTECH, Jet Propuls Lab, Pasadena, CA USA. RP Perovich, DK (reprint author), US Army Engn Res & Dev Ctr, Cold Regions Res & Engn Lab, Hanover, NH USA. EM donald.k.perovich@erdc.usace.army.mil RI Eicken, Hajo/M-6901-2016 NR 26 TC 165 Z9 177 U1 3 U2 24 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 OCT 11 PY 2007 VL 34 IS 19 AR L19505 DI 10.1029/2007GL031480 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 221HL UT WOS:000250217900005 ER PT J AU Song, YT AF Song, Y. Tony TI Detecting tsunami genesis and scales directly from coastal GPS stations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SUMATRA-ANDAMAN EARTHQUAKE; DEFORMATION; SYSTEM; ASIA AB [1] Different from the conventional approach to tsunami warnings that rely on earthquake magnitude estimates, we have found that coastal GPS stations are able to detect continental slope displacements of faulting due to big earthquakes, and that the detected seafloor displacements are able to determine tsunami source energy and scales instantaneously. This method has successfully replicated three historical tsunamis caused by the 2004 Sumatra earthquake, the 2005 Nias earthquake, and the 1964 Alaska earthquake, respectively, and has been compared favorably with the conventional seismic solutions that usually take hours or days to get through inverting seismographs. Because many coastal GPS stations are already in operation for measuring ground motions in real time as often as once every few seconds, this study suggests a practical way of identifying tsunamigenic earthquakes for early warnings and reducing false alarms. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Song, YT (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. EM tony.song@jpl.nasa.gov NR 18 TC 21 Z9 22 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 OCT 11 PY 2007 VL 34 IS 19 AR L19602 DI 10.1029/2007GL031681 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 221HL UT WOS:000250217900006 ER PT J AU Smit, HGJ Straeter, W Johnson, BJ Oltmans, SJ Davies, J Tarasick, DW Hoegger, B Stubi, R Schmidlin, FJ Northam, T Thompson, AM Witte, JC Boyd, I Posny, F AF Smit, Herman G. J. Straeter, Wolfgang Johnson, Bryan J. Oltmans, Samuel J. Davies, Jonathan Tarasick, David W. Hoegger, Bruno Stubi, Rene Schmidlin, F. J. Northam, T. Thompson, Anne M. Witte, Jacquelyn C. Boyd, Ian Posny, Francoise TI Assessment of the performance of ECC-ozonesondes under quasi-flight conditions in the environmental simulation chamber: Insights from the Juelich Ozone Sonde Intercomparison Experiment (JOSIE) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GROUND-BASED LIDAR; BREWER-MAST; ELECTROCHEMICAL SONDES; VERTICAL-DISTRIBUTION; BACKGROUND CURRENT; CATHODE SOLUTIONS; PROFILES; TROPOSPHERE; CAMPAIGN; PUMP AB [1] Since 1996, quality assurance experiments of electrochemical concentration cell (ECC) ozonesondes of two different model types (SPC-6A and ENSCI-Z) have been conducted in the environmental simulation facility at the Research Centre Juelich within the framework of the Juelich Ozone Sonde Intercomparison Experiment (JOSIE). The experiments have shown that the performance characteristics of the two ECC-sonde types can be significantly different, even when operated under the same conditions. Particularly above 20 km the ENSCI-Z sonde tends to measure 5-10% more ozone than the SPC-6A sonde. Below 20 km the differences are 5% or less, but appear to show some differences with year of manufacture. There is a significant difference in the ozone readings when sondes of the same type are operated with different cathode sensing solutions. Testing the most commonly used sensing solutions showed that for each ECC-manufacturer type the use of 1.0% KI and full buffer gives 5% larger ozone values compared with the use of 0.5% KI and half buffer, and as much as 10% larger values compared with 2.0% KI and no buffer. For ozone sounding stations performing long term measurements this means that changing the sensing solution type or ECC-sonde type can easily introduce a change of +/- 5% or more in their records, affecting determination of ozone trends. Standardization of operating procedures for ECC-sondes yields a precision better than +/-(3-5)% and an accuracy of about +/-(5-10)% up to 30 km altitude. C1 Res Ctr Juelich FZJ, Inst Chem & Dynam Geosphere Tropsphere ICG 2, D-52425 Julich, Germany. Natl Ocean & Atmospher Adm, Earth Syst Res Lab, Global Monitoring Div, Boulder, CO USA. Meteo Swiss, Aerol Stn Payeme, Payeme, Switzerland. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. SSAI, Lanham, MD USA. Environm Res Inst, NIWA, Amherst, MA USA. Univ Reunion Island, St Denis, Reunion. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Smit, HGJ (reprint author), Res Ctr Juelich FZJ, Inst Chem & Dynam Geosphere Tropsphere ICG 2, D-52425 Julich, Germany. EM h.smit@fz-juelich.de; w.straeter@fz-juelich.de; bryan.johnson@noaa.gov; samuel.j.oltmans@noaa.gov; jonathan.davies@ec.gc.ca; david.tarasick@ec.gc.ca; hoegger.consulting@bluewin.ch; rene.stubi@meteoswiss.ch; francis.j.schmidlin@nasa.gov; northam@osb.wff.nasa.gov; anne@met.psu.edu; witte@gavial.gsfc.nasa.gov; boyd@fcrao1.astro.umass.edu; posny@univ-reunion.fr RI Smit, Herman/J-2397-2012; Thompson, Anne /C-3649-2014; OI Smit, Herman/0000-0002-2268-4189; Thompson, Anne /0000-0002-7829-0920; Tarasick, David/0000-0001-9869-0692 NR 53 TC 146 Z9 150 U1 2 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 OCT 11 PY 2007 VL 112 IS D19 AR D19306 DI 10.1029/2006JD007308 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 221HW UT WOS:000250219000003 ER PT J AU Rea, N Nichelli, E Israel, GL Perna, R Oosterbroek, T Parmar, AN Turolla, R Campana, S Stella, L Zane, S Angelini, L AF Rea, N. Nichelli, E. Israel, G. L. Perna, R. Oosterbroek, T. Parmar, A. N. Turolla, R. Campana, S. Stella, L. Zane, S. Angelini, L. TI Very deep X-ray observations of the anomalous X-ray pulsar 4U 0142+614 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : magnetic fields; stars : neutron; pulsars : individual : 4U 0142+614; X-rays : stars ID MAGNETIZED NEUTRON-STARS; SOFT GAMMA-REPEATERS; RESONANT CYCLOTRON SCATTERING; 4U 0142+61; 1RXS J170849-400910; XMM-NEWTON; EMISSION; VARIABILITY; SPECTRA; RADIO AB We report on two new XMM-Newton observations of the anomalous X-ray pulsar (AXP) 4U 0142+614 performed in 2004 March and July, collecting the most accurate spectrum for this source. Furthermore, we analyse two short archival observations performed in 2002 February and 2003 January in order to study the long-term behaviour of this AXP. 4U 0142+614 appears to be relatively steady in flux between 2002 and 2004, and the phase-averaged spectrum does not show any significant variability between the four epochs. We derive the deepest upper limits to date on the presence of lines in 4U 0142+614 spectrum as a function of energy: equivalent width in the 1-3 keV energy range < 4 and < 8 eV for narrow and broad lines, respectively. A remarkable energy dependence in both the pulse profile and the pulsed fraction is detected, and consequently pulse-phase spectroscopy shows spectral variability as a function of phase. By making use of XMM-Newton and INTEGRAL data, we successfully model the 1-250 keV spectrum of 4U 0142+614 with three models, namely the canonical absorbed blackbody plus two power laws, a resonant cyclotron scattering model plus one power-law and two log-parabolic functions. C1 SRON, Inst Space Res, NL-3584 CA Utrecht, Netherlands. Osservatorio Astron Rome, INAF, I-00040 Monte Porzio Catone, Italy. Dublin Inst Adv Studies, Dublin 2, Ireland. Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Estec, ESA, Sci Payload & Adv Concepts Off, NL-2200 AG Noordwijk, Netherlands. Estec, ESA, Res & Sci Support Dept, NL-3584 CA Utrecht, Netherlands. Univ Padua, Dept Phys, I-35131 Padua, Italy. Astron Observ Brera, INAF, I-23807 Merate, LE, Italy. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Rea, N (reprint author), SRON, Inst Space Res, Sorbonnelaan 2, NL-3584 CA Utrecht, Netherlands. EM n.rea@sron.nl RI Rea, Nanda/I-2853-2015; OI Rea, Nanda/0000-0003-2177-6388; Parmar, Arvind/0000-0002-3307-6517; Israel, GianLuca/0000-0001-5480-6438 NR 55 TC 24 Z9 24 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD OCT 11 PY 2007 VL 381 IS 1 BP 293 EP 300 DI 10.1111/j.1365-2966.2007.12257.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218CP UT WOS:000249993900047 ER PT J AU Zhou, D Semones, E Gaza, R Johnson, S Zapp, N Weyland, M AF Zhou, D. Semones, E. Gaza, R. Johnson, S. Zapp, N. Weyland, M. TI Radiation measured for ISS-Expedition 12 with different dosimeters SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE cosmic rays; space radiation; active and passive dosimeters; LET spectra ID LOW-EARTH-ORBIT; CR-39 DETECTORS; TRACK DETECTORS; DOSE-EQUIVALENT; COSMIC-RAYS AB Radiation in low Earth orbit (LEO) is mainly from Galactic Cosmic Rays (GCR), solar energetic particles and particles in South Atlantic Anomaly (SAA). These particles' radiation impact to astronauts depends strongly on the particles' linear energy transfer (LET) and is dominated by high LET radiation. It is important to investigate the LET spectrum for the radiation field and the influence of radiation on astronauts. At present, the best active dosimeters used for all LET are the tissue equivalent proportional counter (TEPC) and silicon detectors; the best passive dosimeters are thermoluminescence dosimeters, (TLDs) or optically stimulated luminescence dosimeters (OSLDs) for low LET and CR-39 plastic nuclear track detectors (PNTDs) for high LET. TEPC, CR-39 PNTDs, TLDs and OSLDs were used to investigate the radiation for space mission Expedition 12 (ISS-11S) in LEO. LET spectra and radiation quantities (fluence, absorbed dose, dose equivalent and quality factor) were measured for the mission with these different dosimeters. This paper introduces the operation principles for these dosimeters, describes the method to combine the results measured by CR-39 PNTDs and TLDs/OSLDs, presents the experimental LET spectra and the radiation quantities. Published by Elsevier B.V. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Space Res Assoc, Houston, TX 77058 USA. RP Zhou, D (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 Nasa Rd 1, Houston, TX 77058 USA. EM dzhou@ems.jsc.nasa.gov NR 23 TC 21 Z9 21 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 11 PY 2007 VL 580 IS 3 BP 1283 EP 1289 DI 10.1016/j.nima.2007.06.091 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229BB UT WOS:000250775200013 ER PT J AU Siana, B Teplitz, HI Colbert, J Ferguson, HC Dickinson, M Brown, TM Conselice, CJ de Mello, DF Gardner, JP Giavalisco, M Menanteau, F AF Siana, Brian Teplitz, Harry I. Colbert, James Ferguson, Henry C. Dickinson, Mark Brown, Thomas M. Conselice, Christopher J. de Mello, Duilia F. Gardner, Jonathan P. Giavalisco, Mauro Menanteau, Felipe TI New constraints on the Lyman continuum escape fraction at z similar to 1.3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : evolution; ultraviolet : galaxies ID INITIAL MASS FUNCTION; ULTRA DEEP FIELD; TELESCOPE IMAGING SPECTROGRAPH; QUASI-STELLAR OBJECTS; GOODS-SOUTH FIELD; LY-ALPHA FOREST; LUMINOSITY FUNCTION; STARBURST GALAXIES; STAR-FORMATION; VLT/FORS2 SPECTROSCOPY AB We examine deep far-UV (1600 angstrom) imaging of the HDF-N and the HUDF to search for leaking Lyman continuum radiation from starburst galaxies at z similar to 1.3. There are 21 (primarily sub-L*) galaxies with spectroscopic redshifts between 1.1 < z < 1.5, and none are detected in the far-UV. We fit stellar population templates to the galaxies' optical/near-infrared SEDs to determine the starburst age and level of dust attenuation for each individual galaxy, giving a more accurate estimate of the intrinsic Lyman continuum ratio, f(1500)/f(700), and allowing a conversion from f(700) to relative escape fraction (f(esc,rel)). We show that previous high-redshift studies may have underestimated the amplitude of the Lyman break, and thus the relative escape fraction, by a factor similar to 2. Once the starburst age and intergalactic H-i absorption are accounted for, 18 galaxies in our sample have limits to the relative escape fraction, f(esc,rel) < 1.0 with some limits as low as f(esc,rel) < 0.10 and a stacked limit of f(esc,rel) < 0.08. This demonstrates, for the first time, that most sub-L* galaxies at this redshift do not have large escape fractions. When combined with a similarstudy of more luminous galaxies at the same redshift, we show that, if all star-forming galaxies at z similar to 1 have similar relative escape fractions, the value must be less than 0.14 (3 sigma). We also show that less than 20% (3 sigma) of star-forming galaxies at z similar to 1 have relative escape fractions near unity. These limits contrast with the large escape fractions found at z similar to 3 and suggest that the average escape fraction has decreased between z similar to 3 and z similar to 1. C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Natl Opt Astron Observ, Tucson, AZ 85719 USA. Univ Nottingham, Nottingham NG7 2RD, England. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Observat Cosmol Lab, Greenbelt, MD 20771 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. RP Siana, B (reprint author), CALTECH, Spitzer Sci Ctr, 220-6, Pasadena, CA 91125 USA. EM bsiana@ipac.caltech.edu RI Conselice, Christopher/B-4348-2013; OI Menanteau, Felipe/0000-0002-1372-2534; Brown, Thomas/0000-0002-1793-9968 NR 63 TC 100 Z9 100 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 OCT 10 PY 2007 VL 668 IS 1 BP 62 EP 73 DI 10.1086/521185 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218JA UT WOS:000250010600005 ER PT J AU Malizia, A Landi, R Bassani, L Bird, AJ Molina, M De Rosa, A Fiocchi, M Gehrels, N Kennea, J Perri, M AF Malizia, A. Landi, R. Bassani, L. Bird, A. J. Molina, M. De Rosa, A. Fiocchi, M. Gehrels, N. Kennea, J. Perri, M. TI Swift XRT observation of 34 new integral IBIS AGNs: Discovery of Compton-thick and other peculiar sources SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : Seyfert; X-rays : general ID X-RAY TELESCOPE; ALL-SKY SURVEY; OPTICAL SPECTROSCOPY; OBJECTS; GALAXY; MISSION; NUCLEI; IV AB For a significant number of the sources detected at high energies (> 10 keV) by the INTEGRAL IBIS and Swift BAT instruments there is either a lack information about them in the 2-10 keVrange or they are totally unidentified. Herein, we report on a sample of 34 IBIS AGNs or AGN candidate objects for which there is X-ray data in the Swift XRT archive. Thanks to these X-ray follow-up observations, the identification of the gamma-ray emitters has been possible and the spectral shape in terms of photon index and absorption has been evaluated for the first time for the majority of our sample sources. The sample, enlarged to include four more AGNs already discussed in the literature, has been used to provide photon index and column density distribution. We obtain a mean value of 1.88with a dispersion of 0.12, i. e., typical of anAGNsample. Sixteen objects (47%) have column densities in excess of 10(22) cm(-2) and, as expected, a large fraction of the absorbed sources are within the Sey 2 sample. We have provided a new diagnostic tool (N-H vs. F2-10 keV/F20-100 keV softness ratio) to isolate peculiar objects; we find at least one absorbed Sey 1 galaxy, three Compton-thick AGN candidates; and one secure example of a "true" type 2 AGN. Within the sample of 10 still unidentified objects, 3 are almost certainly AGNs of type 2; 3-4 have spectral slopes typical of AGN; and 2 are located high on the Galactic plane and are strong enough radio emitters that they can be considered good AGN candidates. C1 IASF Bologna, INAF, I-40129 Bologna, Italy. Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. IASF Roma, INAF, I-00133 Rome, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. ASI Sci Data Ctr, I-00044 Frascati, Italy. RP Malizia, A (reprint author), IASF Bologna, INAF, Via P Gobetti 101, I-40129 Bologna, Italy. RI Gehrels, Neil/D-2971-2012; OI Perri, Matteo/0000-0003-3613-4409; Fiocchi, Mariateresa/0000-0001-5697-6019; De Rosa, Alessandra/0000-0001-5668-6863 NR 25 TC 38 Z9 38 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 OCT 10 PY 2007 VL 668 IS 1 BP 81 EP 86 DI 10.1086/520874 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218JA UT WOS:000250010600007 ER PT J AU Abolmasov, PK Swartz, DA Fabrika, S Ghosh, KK Sholukhova, O Tennant, AF AF Abolmasov, Pavel K. Swartz, Douglas A. Fabrika, S. Ghosh, Kajal K. Sholukhova, O. Tennant, Allyn F. TI Optical spectroscopy of the environment of a ULX in NGC 7331 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 7331); galaxies : star clusters; line : formation; X-rays : binaries; X-rays : galaxies; X-rays : individual (CXOU J223706) ID X-RAY SOURCES; SUPERNOVA-REMNANTS; LOW/HARD STATE; HII-REGIONS; WOLF-RAYET; GALAXIES; TELESCOPE; POPULATIONS; COUNTERPART; NGC-6946 AB Optical photometric and spectroscopic data are presented that show an association of an ultraluminous X-ray source in NGC 7331 with a young star cluster of mass M = (1.1 +/- 0.2); 10(5) M-circle dot and age t(c) = 4.25 +/- 0.25 Myr. If the ULX is part of the bright stellar cluster, then the mass of the progenitor of the compact accretor must have been greater than or similar to 40Y50M(circle dot) in order to already have evolved through the supernova stage into a compact object. The companion star is also probably an evolved massive star. The emission-line spectrum of the nebula surrounding the cluster can be interpreted as being a result of photoionization by the cluster OB stars with an additional source of shock excitation producing strong [S II], [O I], and N II lines. This additional source appears to be as much as 5 times more powerful than the supernovae and stellar winds in the cluster can provide for. Additional mechanical energy input associated with the ULX itself can help explain the residual shock-excited line luminosities of the emission region. C1 Russian Acad Sci, Special Astrophys Observ, Nizhnii Arkhyz 369167, Russia. NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35805 USA. Univ Oulu, Oulu 90014, Finland. NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. RP Abolmasov, PK (reprint author), Russian Acad Sci, Special Astrophys Observ, Nizhnii Arkhyz 369167, Russia. NR 44 TC 11 Z9 11 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 OCT 10 PY 2007 VL 668 IS 1 BP 124 EP 129 DI 10.1086/520828 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218JA UT WOS:000250010600011 ER PT J AU Prescott, MKM Kennicutt, RC Bendo, GJ Buckalew, BA Calzetti, D Engelbracht, CW Gordon, KD Hollenbach, DJ Lee, JC Moustakas, J Dale, DA Helou, G Jarrett, TH Murphy, EJ Smith, JDT Akiyama, S Sosey, ML AF Prescott, Moire K. M. Kennicutt, Robert C., Jr. Bendo, George J. Buckalew, Brent A. Calzetti, Daniela Engelbracht, Charles W. Gordon, Karl D. Hollenbach, David J. Lee, Janice C. Moustakas, John Dale, Daniel A. Helou, George Jarrett, Thomas H. Murphy, Eric J. Smith, John-David T. Akiyama, Sanae Sosey, Megan L. TI The incidence of highly obscured star-forming regions in SINGS galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : ISM; galaxies : photometry; HII regions; stars : formation ID H-II-REGIONS; HUBBLE-SPACE-TELESCOPE; LARGE-MAGELLANIC-CLOUD; MULTIBAND IMAGING PHOTOMETER; SPECTRAL ENERGY-DISTRIBUTION; FORMATION RATE INDICATORS; NEARBY GALAXIES; HII-REGIONS; STARBURST GALAXIES; SPIRAL GALAXIES AB Using the new capabilities of Spitzer and extensive multiwavelength data from SINGS, it is now possible to study the infrared properties of star formation in nearby galaxies down to scales equivalent to large H II regions. We are therefore able to determine what fraction of large, infrared-selected star-forming regions in normal galaxies are highly obscured and address how much of the star formation we miss by relying solely on the optical portion of the spectrum. Employing a new empirical method for deriving attenuations of infrared-selected star-forming regions, we investigate the statistics of obscured star formation on 500 pc scales in a sample of 38 nearby galaxies. We find that the median attenuation is 1.4 mag in H alpha and that there is no evidence for a substantial subpopulation of uniformly highly obscured star-forming regions. The regions in the highly obscured tail of the attenuation distribution (A(H alpha) greater than or similar to 3) make up only similar to 4% of the sample of nearly 1800 regions, although very embedded infrared sources on the much smaller scales and lower luminosities of compact and ultracompact H II regions are almost certainly present in greater numbers. The highly obscured cases in our sample are generally the bright, central regions of galaxies with high overall attenuation but are not otherwise remarkable. We also find that a majority of the galaxies show decreasing radial trends in H alpha attenuation. The small fraction of highly obscured regions seen in this sample of normal, star-forming galaxies suggests that on 500 pc scales the timescale for significant dispersal or breakup of nearby, optically thick dust clouds is short relative to the lifetime of a typical star-forming region. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2AX, England. CALTECH, IPAC, Pasadena, CA 91125 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Natl Opt Astron Observ, Tucson, AZ 85719 USA. NYU, Dept Phys, New York, NY 10003 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. RP Prescott, MKM (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. EM mprescott@as.arizona.edu; robk@ast.cam.ac.uk; g.bendo@imperial.ac.uk; brentb@ipac.caltech.edu; calzetti@stsci.edu; cengelbracht@as.arizona.edu; kgordon@as.arizona.edu; hollenba@ism.arc.nasa.gov; jlee@noao.edu; john.moustakas@nyu.edu; ddale@uwyo.edu; gxh@ipac.caltech.edu; jarrett@ipac.caltech.edu; murphy@astro.yale.edu; jdsmith@as.arizona.edu; sakiyama@as.arizona.edu; sosey@stsci.edu NR 85 TC 63 Z9 63 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 OCT 10 PY 2007 VL 668 IS 1 BP 182 EP 202 DI 10.1086/521071 PN 1 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218JA UT WOS:000250010600015 ER PT J AU Kobayashi, H Kawakita, H Mumma, MJ Bonev, BP Watanabe, JI Fuse, T AF Kobayashi, Hitomi Kawakita, Hideyo Mumma, Michael J. Bonev, Boncho P. Watanabe, Jun-ichi Fuse, Tetsuharu TI Organic volatiles in comet 73P-B/Schwassmann-Wachmann 3 observed during its outburst: A clue to the formation region of the Jupiter-family comets SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : individual (73P-B/Schwassmann-Wachmann 3); Kuiper Belt; solar system : formation ID SUBARU TELESCOPE; PARENT VOLATILES; METHANE; WATER; 73P/SCHWASSMANN-WACHMANN-3; NUCLEUS; IMPACT; SPLIT; RATES AB We report the chemical composition of organic molecules in fragment B of comet 73P/Schwassmann-Wachmann 3 ( SW3). Comet SW3 is a Jupiter-family comet that split into three fragments during its 1995 apparition and later into additional components. It was expected that fresh ices from deep within the presplit nucleus were exposed on the surface of each fragment. We observed SW3 with the Subaru telescope in 2006 early May when component B was disintegrating rapidly. If this exposed fresh ices from deeper layers of the original nucleus, mixing ratios obtained from our observations may reflect the pristine nature of the comet. Based on our results, comet SW3-B was depleted in C2H6 and C2H2 with respect to most comets from the Oort Cloud reservoir, suggesting its formation region might have differed from that of the dominant Oort Cloud comets. Furthermore, the chemical composition of SW3-B was similar to that of SW3-C, suggesting that the presplit nucleus was almost homogeneous in volatile composition. The combined results demonstrate that depleted-organics comets from a common formation zone entered both reservoirs, of Jupiter-family comets and and Oort Cloud comets, but likely in different fractions. C1 [Kobayashi, Hitomi; Kawakita, Hideyo] Kyoto Sangyo Univ, Fac Sci, Dept Phys, Kita Ku, Kyoto 6038555, Japan. [Mumma, Michael J.; Bonev, Boncho P.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Watanabe, Jun-ichi; Fuse, Tetsuharu] Natl Astron Observ Japan, Tokyo, Japan. RP Kawakita, H (reprint author), Kyoto Sangyo Univ, Fac Sci, Dept Phys, Kita Ku, Kyoto 6038555, Japan. EM kawakthd@cc.kyoto-su.ac.jp RI mumma, michael/I-2764-2013 NR 25 TC 33 Z9 33 U1 0 U2 9 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 OCT 10 PY 2007 VL 668 IS 1 BP L75 EP L78 DI 10.1086/522586 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218JB UT WOS:000250010700019 ER PT J AU Selwa, M Ofman, L Murawski, K AF Selwa, M. Ofman, L. Murawski, K. TI Numerical simulations of slow standing waves in a curved solar coronal loop SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : oscillations ID VERTICAL OSCILLATIONS; ACOUSTIC-OSCILLATIONS; SUMER; EXCITATION AB We consider slow standing waves that are impulsively excited in a curved solar coronal loop. The numerical model we implement includes the effect of nonlinearity in the frame of two-dimensional ideal magnetohydrodynamics. We discuss the role of curved magnetic field lines and of the slow and fast pulses overlapping at one of the loop's footpoints in the excitation and attenuation of slow standing waves. We find that slow waves can be excited faster in curved loops than in slabs due to the combined effect of the pulse inside and outside the loop. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. UMCS, Inst Phys, Astrophys & Grav Theory Grp, PL-20031 Lublin, Poland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Selwa, M (reprint author), Catholic Univ Amer, Dept Phys, 620 Michigan Ave NE,200 Hannan Hall, Washington, DC 20064 USA. EM mselwa@helio.gsfc.nasa.gov; leon.ofman@gsfc.nasa.gov; kmur@kft.umcs.lublin.pl NR 16 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 OCT 10 PY 2007 VL 668 IS 1 BP L83 EP L86 DI 10.1086/522602 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218JB UT WOS:000250010700021 ER PT J AU Syed, TH Famiglietti, JS Zlotnicki, V Rodell, M AF Syed, T. H. Famiglietti, J. S. Zlotnicki, V. Rodell, M. TI Contemporary estimates of Pan-Arctic freshwater discharge from GRACE and reanalysis SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TIME-VARIABLE GRAVITY; RIVER DISCHARGE; MASS-LOSS; BASIN; VARIABILITY; OCEAN; CYCLE AB [1] Streamflow from Arctic river basins has been increasing in recent decades in response to warming climate. In addition to being a sensitive indicator of global change, Arctic discharge is a critical component of the freshwater budget of the Arctic Ocean, where increasing freshwater flows may slow rates of North Atlantic Deep Water formation and heat transport by the thermohaline circulation. However, quantifying rates of freshwater discharge from the entire Pan-Arctic drainage has been troublesome using traditional stream gauging methods. Here we use satellite measurements of variations in continental water storage from the GRACE mission to present first estimates of monthly freshwater discharge from the entire Pan-Arctic for the period 2003-2005. Results show that rates of Pan-Arctic discharge for this time period ( 3588 +/- 257 km 3 yr(-1)) are significantly larger than those suggested by gauge-based estimates ( 3238 km 3 yr(-1)), and furthermore, may indicate that discharge rates are accelerating. C1 Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Syed, TH (reprint author), Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. EM tsyed@uci.edu RI Rodell, Matthew/E-4946-2012; Syed, Tajdarul/G-6731-2014 OI Rodell, Matthew/0000-0003-0106-7437; NR 29 TC 39 Z9 40 U1 1 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 OCT 10 PY 2007 VL 34 IS 19 AR L19404 DI 10.1029/2007GL031254 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 221HJ UT WOS:000250217700004 ER PT J AU Sun, GY Palazzolo, AB AF Sun, Guangyoung Palazzolo, Alan B. TI Rotor drop and following thermal growth simulations using detailed auxiliary bearing and damper models (vol 289, pg 334, 2006) SO JOURNAL OF SOUND AND VIBRATION LA English DT Correction C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. RP Sun, GY (reprint author), NASA, Glenn Res Ctr, 2100 Brookpark Rd, Cleveland, OH 44135 USA. NR 1 TC 0 Z9 0 U1 0 U2 3 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD OCT 9 PY 2007 VL 306 IS 3-5 BP 975 EP 975 DI 10.1016/j.jsv.2007.05.033 PG 1 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 209FC UT WOS:000249373400037 ER PT J AU Wilson, JW Ott, CM Bentrup, KHZ Ramamurthy, R Quick, L Porwollik, S Cheng, P McClelland, M Tsaprailis, G Radabaugh, T Hunt, A Fernandez, D Richter, E Shah, M Kilcoyne, M Joshi, L Neiman-Gonzalez, M Hing, S Parra, M Dumars, P Norwood, K Bober, R Devich, J Ruggles, A Goulart, C Rupert, M Stodieck, L Stafford, P Catella, L Schurr, MJ Buchanan, K Morici, L McCracken, J Allen, P Baker-Coleman, C Hammond, T Vogel, J Nelson, R Pierson, DL Stefanyshyn-Piper, HM Nickerson, CA AF Wilson, J. W. Ott, C. M. Bentrup, K. Hoenr zu Ramamurthy, R. Quick, L. Porwollik, S. Cheng, P. McClelland, M. Tsaprailis, G. Radabaugh, T. Hunt, A. Fernandez, D. Richter, E. Shah, M. Kilcoyne, M. Joshi, L. Neiman-Gonzalez, M. Hing, S. Parra, M. Dumars, P. Norwood, K. Bober, R. Devich, J. Ruggles, A. Goulart, C. Rupert, M. Stodieck, L. Stafford, P. Catella, L. Schurr, M. J. Buchanan, K. Morici, L. McCracken, J. Allen, P. Baker-Coleman, C. Hammond, T. Vogel, J. Nelson, R. Pierson, D. L. Stefanyshyn-Piper, H. M. Nickerson, C. A. TI Space flight alters bacterial gene expression and virulence and reveals a role for global regulator Hfq SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE microgravity; space shuttle; low shear modeled microgravity; rotating wall vessel; Salmonella ID SHEAR MODELED MICROGRAVITY; ENVELOPE STRESS-RESPONSE; RNA CHAPERONE HFQ; ESCHERICHIA-COLI; SALMONELLA-ENTERICA; MASS-SPECTROMETRY; IRON-METABOLISM; PROTEIN; TYPHIMURIUM; TANDEM AB A comprehensive analysis of both the molecular genetic and phenotypic responses of any organism to the space flight environment has never been accomplished because of significant technological and logistical hurdles. Moreover, the effects of space flight on microbial pathogenicity and associated infectious disease risks have not been studied. The bacterial pathogen Salmonella typhimurium was grown aboard Space Shuttle mission STS-115 and compared with identical ground control cultures. Global microarray and proteomic analyses revealed that 167 transcripts and 73 proteins changed expression with the conserved RNA-binding protein Hfq identified as a likely global regulator involved in the response to this environment. Hfq involvement was confirmed with a ground-based microgravity culture model. Space flight samples exhibited enhanced virulence in a murine infection model and extracellular matrix accumulation consistent with a biofilm. Strategies to target Hfq and related regulators could potentially decrease infectious disease risks during space flight missions and provide novel therapeutic options on Earth. C1 Arizona State Univ, Ctr Infect Dis & Vaccinol, Biodesign Inst, Tempe, AZ 85287 USA. Arizona State Univ, Ctr Glycosci Technol, Biodesign Inst, Tempe, AZ 85287 USA. Arizona State Univ, Ctr Innovat Med, Biodesign Inst, Tempe, AZ 85287 USA. Arizona State Univ, Ctr Combinatorial Sci, Biodesign Inst, Tempe, AZ 85287 USA. Tulane Univ, Ctr Hlth Sci, New Orleans, LA 70112 USA. NASA, Johnson Space Ctr, Astronaut Off, Houston, TX 77058 USA. NASA, Johnson Space Ctr, Habitabil & Environm Factors Div, Houston, TX 77058 USA. Sidney Kimmel Canc Ctr, San Diego, CA 92121 USA. Univ Arizona, Ctr Toxicol, Tucson, AZ 85721 USA. Wyle Labs, Houston, TX 77058 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Kennedy Space Ctr, Space Life Sci Lab, Cape Canaveral, FL 32920 USA. Univ Colorado, Boulder, CO 80309 USA. Univ Colorado, Denver, CO 80262 USA. Hlth Sci Ctr, Denver, CO 80262 USA. Univ Oklahoma, Oklahoma City, OK 73106 USA. Univ Chicago, Sect Gen Surg, Chicago, IL 60637 USA. SE Louisiana Vet Hlth Care Syst, New Orleans, LA 70112 USA. Max Planck Inst Infect Biol, RNA Biol Grp, D-10117 Berlin, Germany. RP Nickerson, CA (reprint author), Arizona State Univ, Ctr Infect Dis & Vaccinol, Biodesign Inst, 1001 S McAllister Ave, Tempe, AZ 85287 USA. EM cheryl.nickerson@asu.edu RI McClelland, Michael/A-8583-2011; Vogel, Jorg/D-5574-2011; OI Vogel, Jorg/0000-0003-2220-1404; Kilcoyne, Michelle/0000-0002-8870-1308; McClelland, Michael/0000-0003-1788-9347 FU NCI NIH HHS [CA023074, P30 CA023074]; NIEHS NIH HHS [ES06694, P30 ES006694] NR 30 TC 152 Z9 165 U1 3 U2 42 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 OCT 9 PY 2007 VL 104 IS 41 BP 16299 EP 16304 DI 10.1073/pnas.0707155104 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 220AH UT WOS:000250128800059 PM 17901201 ER PT J AU Arnaud, KA Babak, S Baker, JG Benacquista, MJ Cornish, NJ Cutler, C Finn, LS Larson, SL Littenberg, T Porter, EK Vallisneri, M Vecchio, A Vinet, JY AF Arnaud, K. A. Babak, S. Baker, J. G. Benacquista, M. J. Cornish, N. J. Cutler, C. Finn, L. S. Larson, S. L. Littenberg, T. Porter, E. K. Vallisneri, M. Vecchio, A. Vinet, J-Y CA LISA Data Challenge Task Force TI An overview of the second round of the mock LISA data challenges SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 11th Gravitational Wave Data Analysis Workshop CY DEC 18-21, 2006 CL Potsdam, GERMANY ID GRAVITATIONAL-RADIATION; POINT MASSES; MOTION AB The Mock Data Challenges (MLDCs) have the dual purpose of fostering the development of LISA data-analysis tools and capabilities and of demonstrating the technical readiness already achieved by the gravitational-wave community in distilling a rich science payoff from the LISA data. The first round of MLDCs has just been completed and the second-round data sets are being released shortly after this workshop. The second-round data sets contain radiation from an entire Galactic population of stellar-mass binary systems, from massive-black-hole binaries, and from extreme-mass-ratio inspirals. These data sets are designed to capture much of the complexity that is expected in the actual LISA data, and should provide a fairly realistic setting to test advanced data-analysis techniques, and in particular the global aspect of the analysis. Here we describe the second round of MLDCs and provide details about its implementation. C1 NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. Univ Texas, Ctr Gravitat Wave Astron, Brownsville, TX 78520 USA. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Penn State Univ, Ctr Gravitat Wave Phys, University Pk, PA 16802 USA. Weber State Univ, Dept Phys, Ogden, UT 84408 USA. Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. Observ Cote Azur, Dept Artemis, F-06304 Nice, France. RP Arnaud, KA (reprint author), NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. RI Larson, Shane/E-8576-2010; Vecchio, Alberto/F-8310-2015; Finn, Lee Samuel/A-3452-2009 OI Vecchio, Alberto/0000-0002-6254-1617; Finn, Lee Samuel/0000-0002-3937-0688 NR 30 TC 32 Z9 32 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD OCT 7 PY 2007 VL 24 IS 19 SI SI BP S551 EP S564 DI 10.1088/0264-9381/24/19/S18 PG 14 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 212LB UT WOS:000249596700019 ER PT J AU Arnaud, KA Auger, G Babak, S Baker, JG Benacquista, MJ Bloomer, E Brown, DA Camp, JB Cannizzo, JK Christensen, N Clark, J Cornish, NJ Crowder, J Cutler, C Finn, LS Halloin, H Hayama, K Hendry, M Jeannin, O Krolak, A Larson, SL Mandel, I Messenger, C Meyer, R Mohanty, S Nayak, R Numata, K Petiteau, A Pitkin, M Plagnol, E Porter, EK Prix, R Roever, C Stroeer, A Thirumalainambi, R Thompson, DE Toher, J Umstaetter, R Vallisneri, M Vecchio, A Veitch, J Vinet, JY TWhelan, J Woan, G AF Arnaud, K. A. Auger, G. Babak, S. Baker, J. G. Benacquista, M. J. Bloomer, E. Brown, D. A. Camp, J. B. Cannizzo, J. K. Christensen, N. Clark, J. Cornish, N. J. Crowder, J. Cutler, C. Finn, L. S. Halloin, H. Hayama, K. Hendry, M. Jeannin, O. Krolak, A. Larson, S. L. Mandel, I. Messenger, C. Meyer, R. Mohanty, S. Nayak, R. Numata, K. Petiteau, A. Pitkin, M. Plagnol, E. Porter, E. K. Prix, R. Roever, C. Stroeer, A. Thirumalainambi, R. Thompson, D. E. Toher, J. Umstaetter, R. Vallisneri, M. Vecchio, A. Veitch, J. Vinet, J-Y TWhelan, J. Woan, G. TI Report on the first round of the mock LISA data challenges SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 11th Gravitational Wave Data Analysis Workshop CY DEC 18-21, 2006 CL Potsdam, GERMANY AB The Mock LISA Data Challenges (MLDCs) have the dual purpose of fostering the development of LISA data analysis tools and capabilities, and demonstrating the technical readiness already achieved by the gravitational-wave community in distilling a rich science payoff from the LISA data output. The first round of MLDCs has just been completed: nine challenges consisting of data sets containing simulated gravitational-wave signals produced either by galactic binaries or massive black hole binaries embedded in simulated LISA instrumental noise were released in June 2006 with deadline for submission of results at the beginning of December 2006. Ten groups have participated in this first round of challenges. All of the challenges had at least one entry which successfully characterized the signal to better than 95% when assessed via a correlation with phasing ambiguities accounted for. Here, we describe the challenges, summarize the results and provide a first critical assessment of the entries. C1 NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. Univ Paris 07, UMR7164, APC, F-75205 Paris 13, France. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. Univ Texas, Ctr Gravitat Wave Astron, Brownsville, TX 78520 USA. Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. CALTECH, LIGO Lab, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Lab Gravitat Phys, Greenbelt, MD 20771 USA. Carleton Coll, Northfield, MN 55057 USA. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Penn State Univ, Ctr Gravitat Wave Phys, University Pk, PA 16802 USA. Polish Acad Sci, Inst Math, Warsaw, Poland. Weber State Univ, Dept Phys, Ogden, UT 84408 USA. Univ Auckland, Dept Stat, Auckland 1, New Zealand. Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Observ Cote Azur, Dept Artemis, F-06304 Nice, France. RP Arnaud, KA (reprint author), NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. EM benacquista@phys.utb.edu RI Larson, Shane/E-8576-2010; Pitkin, Matthew/I-3802-2013; Vecchio, Alberto/F-8310-2015; Finn, Lee Samuel/A-3452-2009; OI Pitkin, Matthew/0000-0003-4548-526X; Vecchio, Alberto/0000-0002-6254-1617; Finn, Lee Samuel/0000-0002-3937-0688; Rover, Christian/0000-0002-6911-698X; Veitch, John/0000-0002-6508-0713; Whelan, John/0000-0001-5710-6576 NR 26 TC 24 Z9 24 U1 0 U2 1 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 OCT 7 PY 2007 VL 24 IS 19 SI SI BP S529 EP S539 DI 10.1088/0264-9381/24/19/S16 PG 11 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 212LB UT WOS:000249596700017 ER PT J AU Brown, DA Crowder, J Cutler, C Mandel, I Vallisneri, M AF Brown, Duncan A. Crowder, Jeff Cutler, Curt Mandel, Ilya Vallisneri, Michele TI A three-stage search for supermassive black-hole binaries in LISA data SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 11th Gravitational Wave Data Analysis Workshop CY DEC 18-21, 2006 CL Potsdam, GERMANY ID INSPIRALLING COMPACT BINARIES; GRAVITATIONAL-WAVES; DATA CHALLENGES; SYSTEMS; HISTORY; MODELS AB Gravitational waves from the inspiral and coalescence of supermassive black-hole (SMBH) binaries with masses m(1) similar to m(2) similar to 10(6)M(circle dot) are likely to be among the strongest sources for the Laser Interferometer Space Antenna (LISA). We describe a three-stage data-analysis pipeline designed to search for and measure the parameters of SMBH binaries in LISA data. The first stage uses a time frequency track-search method to search for inspiral signals and provide a coarse estimate of the black-hole masses m(1), m(2) and the coalescence time of the binary t(c). The second stage uses a sequence of matched-filter template banks, seeded by the first stage, to improve the measurement accuracy of the masses and coalescence time. Finally, a Markov chain Monte Carlo search is used to estimate all nine physical parameters of the binary ( masses, coalescence time, distance, initial phase, sky position and orientation). Using results from the second stage substantially shortens the Markov chain burn-in time and allows us to determine the number of SMBH-binary signals in the data before starting parameter estimation. We demonstrate our analysis pipeline using simulated data from the first Mock LISA Data Challenge. We discuss our plan for improving this pipeline and the challenges that will be faced in real LISA data analysis. C1 CALTECH, LIGO Lab, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Brown, DA (reprint author), CALTECH, LIGO Lab, Pasadena, CA 91125 USA. NR 36 TC 18 Z9 18 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 EI 1361-6382 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD OCT 7 PY 2007 VL 24 IS 19 SI SI BP S595 EP S605 DI 10.1088/0264-9381/24/19/S22 PG 11 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 212LB UT WOS:000249596700023 ER PT J AU Crowder, J Cornish, NJ AF Crowder, Jeff Cornish, Neil J. TI Extracting galactic binary signals from the first round of Mock LISA Data Challenges SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 11th Gravitational Wave Data Analysis Workshop CY DEC 18-21, 2006 CL Potsdam, GERMANY ID MCMC AB We report on the performance of an end-to-end Bayesian analysis pipeline for detecting and characterizing galactic binary signals in simulated LISA data. Our principal analysis tool is the blocked-annealed Metropolis-Hasting (BAM) algorithm, which has been optimized to search for tens of thousands of overlapping signals across the LISA band. The BAM algorithm employs Bayesian model selection to determine the number of resolvable sources, and provides posterior density functions for all the model parameters. The BAM algorithm performed almost flawlessly on all the round 1 Mock LISA Data Challenge data sets, including those with many highly overlapping sources. Some misses were later traced to a particular flaw in the coding that affected high frequency sources. In addition to the BAM algorithm we also successfully tested a genetic algorithm (GA), but only on data sets with isolated signals as the GA has yet to be optimized to handle large numbers of overlapping signals. C1 Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Crowder, J (reprint author), Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. NR 27 TC 14 Z9 14 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD OCT 7 PY 2007 VL 24 IS 19 SI SI BP S575 EP S585 DI 10.1088/0264-9381/24/19/S20 PG 11 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 212LB UT WOS:000249596700021 ER PT J AU Holzmann, GJ Bosnacki, D AF Holzmann, Gerard J. Bosnacki, Dragan TI The design of a multicore extension of the SPIN model checker SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Article DE software/program verification; model checking; models of computation; logics and meanings of programs; distributed programming AB We describe an extension of the SPIN model checker for use on multicore shared-memory systems and report on its performance. We show how, with proper load balancing, the time requirements of a verification run can, in some cases, be reduced close to N-fold when N processing cores are used. We also analyze the types of verification problems for which multicore algorithms cannot provide relief. The extensions discussed here require only relatively small changes in the SPIN source code and are compatible with most existing verification modes such as partial order reduction, the verification of temporal logic formulas, bitstate hashing, and hash-compact compression. C1 CALTECH, Jet Prop Labs, Lab Reliable Software, Pasadena, CA 91109 USA. Eindhoven Univ Technol, NL-5600 MB Eindhoven, Netherlands. RP Holzmann, GJ (reprint author), CALTECH, Jet Prop Labs, Lab Reliable Software, 4800 Oak Grove Dr,NADA-JPL MS 301-230, Pasadena, CA 91109 USA. EM gerard@spinroot.com; dragan@win.tue.nl NR 38 TC 41 Z9 42 U1 1 U2 4 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0098-5589 EI 1939-3520 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD OCT 7 PY 2007 VL 33 IS 10 BP 659 EP 674 DI 10.1109/TSE.2007.70724 PG 16 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 204XB UT WOS:000249076200002 ER PT J AU Han, WQ Yuan, DL Liu, WT Halkides, DJ AF Han, Weiqing Yuan, Dongliang Liu, W. Timothy Halkides, D. J. TI Intraseasonal variability of Indian Ocean sea surface temperature during boreal winter: Madden-Julian Oscillation versus submonthly forcing and processes (vol 112, artn C04001, 2007) SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Correction C1 Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. Chinese Acad Sci, Inst Oceanol, Qingdao, Peoples R China. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Han, WQ (reprint author), Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. NR 1 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-OCEANS JI J. Geophys. Res.-Oceans PD OCT 6 PY 2007 VL 112 IS C10 AR C10007 DI 10.1029/2007JC004544 PG 1 WC Oceanography SC Oceanography GA 218WO UT WOS:000250046900002 ER PT J AU Ye, HC Fetzer, EJ Bromwich, DH Fishbein, EF Olsen, ET Granger, SL Lee, SY Chen, L Lambrigtsen, BH AF Ye, Hengchun Fetzer, Eric J. Bromwich, David H. Fishbein, Evan F. Olsen, Edward T. Granger, Stephanie L. Lee, Sung-Yung Chen, Luke Lambrigtsen, Bjorn H. TI Atmospheric total precipitable water from AIRS and ECMWF during Antarctic summer SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIOSONDES AB [1] This study compares the atmospheric total precipitable water (PWV) obtained by Atmospheric Infrared Sounder (AIRS) with radiosondes and the European Centre for Medium-range Weather Forecasts (ECMWF) operational analysis products during December 2003 and January 2004. We find that PWV from AIRS Level 3 (daily gridded) data is about 9% drier while ECMWF is 14% moister than sondes at the two grid points closest to the Dome C radiosonde site on the Antarctic Plateau at 3233 m elevation. The largest ECMWF moist biases occur on warmer days at Dome C. When AIRS Level 3 data are compared with ECMWF over the entire Antarctic continent, AIRS and ECMWF PWV have similar variability (correlation coefficients are predominantly 0.8 or higher), but with AIRS drier over most of the Antarctic by a consistent offset of about 0.1-0.2 mm. Because of this constant difference, the largest percentage differences are found over the highland areas of about 2500 meters and above, where absolute water vapor amounts are smallest. C1 Ohio State Univ, Byrd Polar Res Ctr, Polar Meteorol Grp, Columbus, OH 43210 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Calif State Univ Los Angeles, Dept Geog & Urban Anal, Los Angeles, CA 90032 USA. RP Ye, HC (reprint author), Ohio State Univ, Byrd Polar Res Ctr, Polar Meteorol Grp, 1090 Carmack Rd, Columbus, OH 43210 USA. RI Bromwich, David/C-9225-2016 NR 26 TC 11 Z9 11 U1 0 U2 0 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 OCT 5 PY 2007 VL 34 IS 19 AR L19701 DI 10.1029/2006GL028547 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 218WA UT WOS:000250045500001 ER PT J AU Gardner, JL Funke, B Mlynczak, MG Lopez-Puertas, M Martin-Torres, FJ Russell, JM Miller, SM Sharma, RD Winick, JR AF Gardner, J. L. Funke, B. Mlynczak, M. G. Lopez-Puertas, M. Martin-Torres, F. J. Russell, J. M., III Miller, S. M. Sharma, R. D. Winick, J. R. TI Comparison of nighttime nitric oxide 5.3 mu m emissions in the thermosphere measured by MIPAS and SABER SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TERRESTRIAL THERMOSPHERE; LIMB RADIANCE; ROTATIONAL DISTRIBUTION; GLOBAL OBSERVATIONS; MODEL; NO; DISTRIBUTIONS; MESOSPHERE AB [1] A comparative study of nitric oxide (NO) 5.3 mu m emissions in the thermosphere measured by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) spectrometer and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) radiometer satellite instruments was conducted for nighttime data collected on 14 June 2003. The agreement between the data sets was very good, within similar to 25% over the entire latitude range studied from -58 degrees to + 4 degrees. The MIPAS and SABER data were inverted to retrieve NO volume emission rates. Spectral fitting of the MIPAS data was used to determine the NO(v= 1) rotational and spin-orbit temperatures, which were found to be in nonlocal thermodynamic equilibrium (non-LTE) above 110 km. Near 110 km the rotational and spin-orbit temperatures converged, indicating the onset of equilibrium in agreement with the results of non-LTE modeling. Because of the onset of equilibrium the NO rotational and spin-orbit temperatures can be used to estimate the kinetic temperature near 110 km. The results indicate that the atmospheric model NRLMSISE-00 underestimates the kinetic temperature near 110 km for the locations investigated. The SABER instrument 5.3 mm band filter cuts off a significant fraction of the NO(Delta v = 1) band, and therefore modeling of NO is necessary to predict the total band radiance. The needed correction factors were directly determined from the MIPAS data, providing validation of the modeled values used in SABER operational data processing. The correction factors were applied to the SABER data to calculate densities of NO(v = 1). A feasibility study was also conducted to investigate the use of NO 5.3 mm emission data to derive NO(v = 0) densities in the thermosphere. C1 Stewart Radiance Lab, Bedford, MA 01730 USA. CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. NASA Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. Analyt Serv & Mat Inc, NASA Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. Hanscom AFB, Space Vehicles Directorate, Air Force Res Lab, Bedford, MA 01731 USA. RP Gardner, JL (reprint author), Stewart Radiance Lab, 139 Great Rd, Bedford, MA 01730 USA. EM jennifer.gardner.ctr@hanscom.af.mil RI Mlynczak, Martin/K-3396-2012; Lopez Puertas, Manuel/M-8219-2013; Funke, Bernd/C-2162-2008; Martin-Torres, Francisco Javier/G-6329-2015 OI Lopez Puertas, Manuel/0000-0003-2941-7734; Funke, Bernd/0000-0003-0462-4702; Martin-Torres, Francisco Javier/0000-0001-6479-2236 NR 28 TC 10 Z9 10 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 5 PY 2007 VL 112 IS A10 AR A10301 DI 10.1029/2006JA011984 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218WV UT WOS:000250047600002 ER PT J AU Schopf, JW Kudryavtsev, AB Czaja, AD Tripathi, AB AF Schopf, J. William Kudryavtsev, Anatoliy B. Czaja, Andrew D. Tripathi, Abhishek B. TI Evidence of archean life: Stromatolites and microfossils SO PRECAMBRIAN RESEARCH LA English DT Article; Proceedings Paper CT Symposium on Paleobiology of the Early Earth held at the 2nd International Palaeontological Congress CY JUN, 2006 CL Beijing Univ, Beijing, PEOPLES R CHINA HO Beijing Univ DE archean; stromatolites; microfossils; oldest life; Raman imagery; apex basalt; apex chert ID BARBERTON MOUNTAIN LAND; LASER-RAMAN IMAGERY; NORTH-POLE AREA; WESTERN-AUSTRALIA; SOUTH-AFRICA; FILAMENTOUS MICROFOSSILS; PRECAMBRIAN FOSSILS; ONVERWACHT GROUP; CARBON ISOTOPES; EARTH HISTORY AB Fossil evidence of the existence of life during the Archean Eon of Earth history (>2500 Ma) is summarized. Data are outlined for 48 Archean deposits reported to contain biogenic stromatolites and for 14 such units that contain a total of 40 morphotypes of described microfossils. Among the oldest of these putatively microfossiliferous units is a brecciated chert of the similar to 3465 Ma Apex Basalt of Western Australia. The paleoenvironment, carbonaceous composition, mode of preservation, and morphology of the Apex microbe-like filaments, backed by new evidence of their cellular structure provided by two- and three-dimensional Raman imagery, support their biogenic interpretation. Such data, together with the presence of stromatolites, microfossils, and carbon isotopic evidence of biological activity in similarly aged deposits, indicate that the antiquity of life on Earth extends to at least similar to 3500 Ma. (c) 2007 Elsevier B.V. All rights reserved. C1 Univ Calif Los Angeles, Dept Earth & Space Sci, Ctr Study Evolut & Origin Life, Inst Geophys & Planetary Sci,Mol Biol Inst, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, NASA, Astrobiol Inst, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Sci, Ctr Study Evolut & Origin Life, Los Angeles, CA 90095 USA. RP Schopf, JW (reprint author), Univ Calif Los Angeles, Dept Earth & Space Sci, Ctr Study Evolut & Origin Life, Inst Geophys & Planetary Sci,Mol Biol Inst, Los Angeles, CA 90095 USA. EM schopf@ess.ucia.edu NR 75 TC 134 Z9 146 U1 7 U2 63 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-9268 J9 PRECAMBRIAN RES JI Precambrian Res. PD OCT 5 PY 2007 VL 158 IS 3-4 BP 141 EP 155 DI 10.1016/j.precamres.2007.04.009 PG 15 WC Geosciences, Multidisciplinary SC Geology GA 224GT UT WOS:000250436200002 ER PT J AU Allwood, AC Walter, MR Burch, IW Kamber, BS AF Allwood, Abigail C. Walter, Malcolm R. Burch, Ian W. Kamber, Balz S. TI 3.43 billion-year-old stromatolite reef from the Pilbara Craton of western Australia: Ecosystem-scale insights to early life on Earth SO PRECAMBRIAN RESEARCH LA English DT Article; Proceedings Paper CT Symposium on Paleobiology of the Early Earth held at the 2nd International Palaeontological Congress CY JUN, 2006 CL Beijing Univ, Beijing, PEOPLES R CHINA HO Beijing Univ DE stromatolites; microbialites; morphology; biogenic; reef; carbonate platform; rocky shoreline; evaporites; early archaean; pilbara; strelley pool chert; Kelly group; North Pole dome; Panorama greenstone belt; dolomite; carbonate; chert; rare earth elements ID BARBERTON MOUNTAIN LAND; SOUTH-AFRICA; ROCKY SHORELINES; WARRAWOONA GROUP; ONVERWACHT GROUP; FOSSIL EVIDENCE; APEX CHERT; NORTH-POLE; GA; MICROFOSSILS AB The 3.43 billion-year-old Strelley Pool Chert, Pilbara Craton, Western Australia, contains compelling evidence of Early Archaean life in the form of kilometre-sized remnants of an ancient stromatolitic carbonate platform. Reviewing and building on earlier studies, we examine the fossilized remains of the platform to seek ecosystem-scale insights to Earth's early biosphere, examining the evidence for biosedimentation, and the importance and effect of different environmental processes on biological activity. Both vertical and lateral trends show that stromatolite abundance and diversity are greatest in the area interpreted as an isolated, partially restricted, peritidal marine carbonate platform, or reef, where there is virtually no trace of hydrothermal or terrigenous clastic input. In contrast, stromatolites are poorly developed or absent among hydrothermal, volcaniclastic or terrigenous clastic sedimentary facies, and are absent in deeper marine settings that are laterally equivalent to shallow marine stromatolitic facies. Hydrothermal veins, some of which were previously interpreted as vents that exhaled fluids from which the stromatolitic structures precipitated, are shown to postdate the stromatolites. On the platform, stromatolite facies associations varied between different palaeoenvironments, but some stromatolite types occurred across different palaeoenvironments, highlighting the combined influence of biological and environmental processes on stromatolite formation. The regional distribution of stromatolites in the palaeoenvironment suggests a biological response to variations in water depth, sediment influx and hydrothermal activity with stromatolite formation favoured by relatively 'normal' shallow marine environments with low clastic/chemical sedimentation rates and no direct input from high temperature hydrothermal systems. The lithology, structure and fabrics of the stromatolites, and their close association with abundant evaporite crystal pseudomorphs, indicate that evaporitic precipitation was probably the dominant non-biological process that contributed to stromatolite formation. The study supports a biological interpretation for the origin of the stromatolites, and reveals compelling evidence for the conditions that favoured biological activity on the early Earth and formation of macroscopic biosignatures that could be preserved for most of Earth's history. (c) 2007 Elsevier B.V. All rights reserved. C1 NASA, Jet Prop Lab, Pasadena, CA 91024 USA. Macquarie Univ, Dept Earth & Planetary Sci, Australian Ctr Astrobiol, N Ryde, NSW 2109, Australia. Laurentian Univ, Dept Earth Sci, Sudbury, ON P3E 2C6, Canada. RP Allwood, AC (reprint author), NASA, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91024 USA. EM Abigail.C.Allwood@jpl.nasa.gov RI Kamber, Balz/A-1823-2008 OI Kamber, Balz/0000-0002-8720-0608 NR 69 TC 72 Z9 80 U1 2 U2 60 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-9268 J9 PRECAMBRIAN RES JI Precambrian Res. PD OCT 5 PY 2007 VL 158 IS 3-4 BP 198 EP 227 DI 10.1016/j.precamres.2007.04.013 PG 30 WC Geosciences, Multidisciplinary SC Geology GA 224GT UT WOS:000250436200005 ER PT J AU Mather, JC AF Mather, John C. TI Science and Sputnik SO SCIENCE LA English DT Editorial Material C1 NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. NASA Headquarters, Sci Mission Directorate, Washington, DC 20546 USA. RP Mather, JC (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. EM John.C.Mather@nasa.gov NR 2 TC 0 Z9 0 U1 0 U2 1 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 OCT 5 PY 2007 VL 318 IS 5847 BP 52 EP 53 DI 10.1126/science.1148553 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 216YR UT WOS:000249915400029 PM 17916715 ER PT J AU Khazendar, A Rignot, E Larour, E AF Khazendar, A. Rignot, E. Larour, E. TI Larsen B Ice Shelf rheology preceding its disintegration inferred by a control method SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTIC PENINSULA; CLIMATE-CHANGE; COLLAPSE; PATTERN; MODEL AB [1] A new, complete velocity field from satellite remote sensing is combined with numerical modeling to infer the rheology of the Larsen B Ice Shelf before its disintegration. The resulting spatial distribution of the flow parameter exhibits large variability, which reflects very well observed ice shelf features. This variability is explained by factors including advection of colder ice from tributary glaciers, bottom melting, and the presence of zones of strong shear and fracture. The inferred distribution is applied to simulate numerically the flow regime of the ice shelf and to examine its modification by the presence of open rifts and by the retreat of ice shelf front between 1996 and 2000. Results demonstrate that variable rheology is essential to understanding ice shelf evolution, especially the close relationship among frontal retreat, fracture, ice flow acceleration, and the destabilization of ice shelves. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Khazendar, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ala.khazendar@jpl.nasa.gov RI Rignot, Eric/A-4560-2014 OI Rignot, Eric/0000-0002-3366-0481 NR 20 TC 42 Z9 42 U1 2 U2 13 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 OCT 4 PY 2007 VL 34 IS 19 AR L19503 DI 10.1029/2007GL030980 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 218VZ UT WOS:000250045400001 ER PT J AU Nghiem, SV Rigor, IG Perovich, DK Clemente-Colon, P Weatherly, JW Neumann, G AF Nghiem, S. V. Rigor, I. G. Perovich, D. K. Clemente-Colon, P. Weatherly, J. W. Neumann, G. TI Rapid reduction of Arctic perennial sea ice SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EXTENT; VARIABILITY; OSCILLATION AB [1] The extent of Arctic perennial sea ice, the year-round ice cover, was significantly reduced between March 2005 and March 2007 by 1.08 X 10(6) km(2), a 23% loss from 4.69 X 10(6) km(2) to 3.61 X 10(6) km(2), as observed by the QuikSCAT/ SeaWinds satellite scatterometer ( QSCAT). Moreover, the buoy-based Drift-Age Model (DM) provided long-term trends in Arctic sea-ice age since the 1950s. Perennial-ice extent loss in March within the DM domain was noticeable after the 1960s, and the loss became more rapid in the 2000s when QSCAT observations were available to verify the model results. QSCAT data also revealed mechanisms contributing to the perennial-ice extent loss: ice compression toward the western Arctic, ice loading into the Transpolar Drift (TD) together with an acceleration of the TD carrying excessive ice out of Fram Strait, and ice export to Baffin Bay. Dynamic and thermodynamic effects appear to be combining to expedite the loss of perennial sea ice. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Washington, Polar Sci Ctr, Appl Phys Lab, Seattle, WA 98195 USA. Cold Reg Res & Engn Lab, Hanover, NH USA. Natl Ice Ctr, Suitland, MA USA. RP Nghiem, SV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Son.V.Nghiem@jpl.nasa RI Clemente-Colon, Pablo/F-5581-2010 NR 20 TC 201 Z9 214 U1 4 U2 38 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 OCT 4 PY 2007 VL 34 IS 19 AR L19504 DI 10.1029/2007GL031138 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 218VZ UT WOS:000250045400002 ER PT J AU Sutter, B Dalton, JB Ewing, SA Amundson, R Mckay, CP AF Sutter, B. Dalton, J. B. Ewing, S. A. Amundson, R. Mckay, C. P. TI Terrestrial analogs for interpretation of infrared spectra from the Martian surface and subsurface: Sulfate, nitrate, carbonate, and phyllosilicate-bearing Atacama Desert soils SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES LA English DT Article ID X-RAY SPECTROMETER; MINI-TES EXPERIMENT; REFLECTANCE SPECTROSCOPY; MERIDIANI-PLANUM; OMEGA/MARS EXPRESS; MU-M; CHEMICAL-COMPOSITION; NORTHERN CHILE; GUSEV CRATER; MAUNA-KEA AB [1] Hyperarid (< 2 mm y(-1)) Atacama Desert soils of northern Chile are known for nitrate, sulfate, and chloride accumulations. Atacama and Mars soils have similar sulfate concentrations; possess phyllosilicates (e. g., smectite) and minor carbonate. Nitrate has not been detected on Mars, but its presence has been proposed. The similar compositions of Atacama and Mars soils have prompted the visible-infrared (0.35-25 mm) investigation of Atacama soils as Mars analogs. Results from this work determined the best infrared features for detecting sulfate, nitrate, carbonate, and phyllosilicate on Mars. The fundamental region (> 6.5 mm) was not suited for salt and phyllosilicate detection because of overlapping spectra from primary silicates (e. g., feldspar), water and carbon dioxide. The visible near-infrared (0.35-2.5 mu m) region was suited for detecting carbonate, nitrate, gypsum water of hydration, and phyllosilicate hydroxyls without interference from primary silicates. However, gypsum water of hydration features can obscure phyllosilicate hydroxyl, carbonate and nitrate, features if gypsum levels are high. Overtone/ combination absorption features in the midinfrared were determined to be the best indicators of sulfate (4.48-4.70 mu m), nitrate (4.12 mu m), and carbonate (3.98 mu m) because interferences from overlapping primary silicate and water features are not present in this region. Interferences from CO2 and thermal emission effects in the overtone/ combination region are possible but may be minimized by corrective techniques. Infrared analysis of Atacama Desert soils can provide insight into the spectral search of sulfate, nitrate, carbonate, and phyllosilicate containing soils on Mars. C1 NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. NASA, Lyndon B Johnson Space Ctr, ESCG, Houston, TX 77058 USA. Univ Calif Berkeley, Div Ecosyst Sci, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Sutter, B (reprint author), NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. EM brad.sutter-2@nasa.gov RI Amundson, Ronald /E-2654-2015 NR 86 TC 13 Z9 13 U1 1 U2 21 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-8953 EI 2169-8961 J9 J GEOPHYS RES-BIOGEO JI J. Geophys. Res.-Biogeosci. PD OCT 4 PY 2007 VL 112 IS G4 AR G04S10 DI 10.1029/2006JG000313 PG 19 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 218WL UT WOS:000250046600001 ER PT J AU Winker, DM Hunt, WH McGill, MJ AF Winker, David M. Hunt, William H. McGill, Matthew J. TI Initial performance assessment of CALIOP SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SPACEBORNE LIDAR; MISSION; CLOUDS AB The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP, pronounced the same as "calliope'') is a spaceborne two-wavelength polarization lidar that has been acquiring global data since June 2006. CALIOP provides high resolution vertical profiles of clouds and aerosols, and has been designed with a very large linear dynamic range to encompass the full range of signal returns from aerosols and clouds. CALIOP is the primary instrument carried by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite, which was launched on April 28, 2006. CALIPSO was developed within the framework of a collaboration between NASA and the French space agency, CNES. Initial data analysis and validation inter-comparisons indicate the quality of data from CALIOP meets or exceeds expectations. This paper presents a description of the CALIPSO mission, the CALIOP instrument, and an initial assessment of on-orbit measurement performance. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. Sci Syst & Appl Inc, Hampton, VA USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Winker, DM (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. EM david.m.winker@nasa.gov RI McGill, Matthew/D-8176-2012 NR 9 TC 584 Z9 597 U1 10 U2 72 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 OCT 3 PY 2007 VL 34 IS 19 AR L19803 DI 10.1029/2007GL030135 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 218VY UT WOS:000250045300002 ER PT J AU Bullock, MA Moore, JM AF Bullock, Mark A. Moore, Jeffrey M. TI Atmospheric conditions on early Mars and the missing layered carbonates SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OMEGA/MARS EXPRESS; MERIDIANI-PLANUM; GEOCHEMISTRY; HISTORY; ROCKS; CO2 AB Widespread, massive layered sediments, studied by surface rovers and Mars-orbiting spectrometers, are found to be rich in sulfates. No similarly massive carbonates have been detected. We present the results of coupled atmospheric and geochemical calculations of the formation of the sulfate-rich Meridiani sediments, and offer an explanation for why extensive layered carbonates are not found there or elsewhere on Mars. Large scale volcanism from the build-up of Tharsis during the late Noachian would have injected large amounts of SO2 into the atmosphere. Efficient photochemical conversion of SO2 to H2SO4 would have caused widespread sulfuric acid/water clouds, similar to those seen on Venus today. Precipitation from these clouds and acidification of surface water would have sustained a thick, warm CO2 atmosphere via carbonate inhibition. Such an atmosphere could have been subjected to loss to space via impact erosion and sputtering. Once atmospheric SO2 gas production dropped and waters become more alkaline, the remaining CO2 in the atmosphere collapsed to form poorly consolidated carbonate patinas on rock surfaces and in open fractures. C1 SW Res Ctr, Dept Space Studies, Boulder, CO USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bullock, MA (reprint author), SW Res Ctr, Dept Space Studies, Boulder, CO USA. EM bullock@boulder.swri.edu; jeff.moore@nasa.gov NR 37 TC 39 Z9 39 U1 1 U2 8 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 OCT 2 PY 2007 VL 34 IS 19 AR L19201 DI 10.1029/2007GL030688 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 218VX UT WOS:000250045200003 ER PT J AU Kovalenko, LJ Jucks, KW Salawitch, RJ Toon, GC Blavier, JF Johnson, DG Kleinbohl, A Livesey, NJ Margitan, JJ Pickett, HM Santee, ML Sen, B Stachnik, RA Waters, JW AF Kovalenko, L. J. Jucks, K. W. Salawitch, R. J. Toon, G. C. Blavier, J.-F. Johnson, D. G. Kleinboehl, A. Livesey, N. J. Margitan, J. J. Pickett, H. M. Santee, M. L. Sen, B. Stachnik, R. A. Waters, J. W. TI Observed and modeled HOCl profiles in the midlatitude stratosphere: Implication for ozone loss SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TEMPERATURE-DEPENDENCE; REACTION-KINETICS; HO2+CLO REACTION; AB-INITIO; CLO; HO2; SURFACE AB Vertical profiles of stratospheric HOCl calculated with a diurnal steady-state photochemical model that uses currently recommended reaction rates and photolysis cross sections underestimate observed profiles of HOCl obtained by two balloon-borne instruments, FIRS-2 (a far-infrared emission spectrometer) and MkIV (a mid-infrared, solar absorption spectrometer). Considerable uncertainty (a factor of two) persists in laboratory measurements of the rate constant (k(1)) for the reaction ClO + HO2 -> HOCl + O-2. Agreement between modeled and measured HOCl can be attained using a value of k(1) from Stimpfle et al. (1979) that is about a factor-of-two faster than the currently recommended rate constant. Comparison of modeled and measured HOCl suggests that models using the currently recommended value for k(1) may underestimate the role of the HOCl catalytic cycle for ozone depletion, important in the midlatitude lower stratosphere. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Columbus Technol Inc, Pleasanton, CA USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Kovalenko, LJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM ljk@mls.jpl.nasa.gov RI Salawitch, Ross/B-4605-2009; Johnson, David/F-2376-2015 OI Salawitch, Ross/0000-0001-8597-5832; Johnson, David/0000-0003-4399-5653 NR 18 TC 11 Z9 11 U1 0 U2 4 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 OCT 2 PY 2007 VL 34 IS 19 AR L19801 DI 10.1029/2007GL031100 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 218VX UT WOS:000250045200005 ER PT J AU Kwok, R AF Kwok, Ron TI Baffin Bay ice drift and export: 2002-2007 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEA-ICE; DAVIS STRAIT; WATER; MOTION; VARIABILITY; DYNAMICS; OCEAN AB Multiyear estimates of sea ice drift in Baffin Bay and Davis Strait are derived for the first time from the 89 GHz channel of the AMSR-E instrument. Uncertainties in the drift estimates, assessed with Envisat ice motion, are similar to 2-3 km/day. A persistent atmospheric trough, between the coast of Greenland and Baffin Island, drives the prevailing southward drift pattern with average daily displacements in excess of 18-20 km during winter. Over the 5-year record, the ice export ranges between 360 and 675 x 10(3) km(2), with an average of 530 x 10(3) km(2). Sea ice area inflow from the Nares Strait, Lancaster Sound and Jones Sound potentially contribute up to a third of the net area outflow while ice production at the North Water Polynya contributes the balance. Rough estimates of annual volume export give similar to 500-800 km(3). Comparatively, these are similar to 70% and similar to 30% of the annual area and volume exports at the Fram Strait. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ron.kwok@jpl.nasa.gov RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 16 TC 12 Z9 12 U1 0 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 OCT 2 PY 2007 VL 34 IS 19 AR L19501 DI 10.1029/2007GL031204 PG 7 WC Geosciences, Multidisciplinary SC Geology GA 218VX UT WOS:000250045200006 ER PT J AU Kota, AK Cipriano, BH Duesterberg, MK Gershon, AL Powell, D Raghavan, SR Bruck, HA AF Kota, Arun K. Cipriano, Bani H. Duesterberg, Matthew K. Gershon, Alan L. Powell, Dan Raghavan, Srinivasa R. Bruck, Hugh A. TI Electrical and rheological percolation in polystyrene/MWCNT nanocomposites SO MACROMOLECULES LA English DT Article ID MULTIWALLED CARBON NANOTUBES; NANOTUBE/POLYMER COMPOSITES; EPOXY COMPOSITES; BEHAVIOR; POLYCARBONATE; CONDUCTIVITY; POLYETHYLENE; ORIENTATION; THRESHOLD AB A systematic electrical and rheological characterization of percolation in commercial polydisperse polystyrene (PS) nanocomposites containing multiwall carbon nanombes (MWCNTs) is presented. The MWCNTs confer appreciable electrical conductivities (up to ca. 1 S/m) to these nanocomposites at a concentration of 8 vol %. In addition to enhancing the electrical properties, even at small concentrations (ca. 2 vol %), MWCNTs significantly enhance the rheological properties of PS melts. At concentrations exceeding 2 vol %, a plateau appears in the storage modulus G' at low frequencies, indicating the formation of a percolated MWCNT network that responds elastically over long timescales. Network formation, in turn, implies a diverging complex viscosity vs complex modulus curve. A focus of this study is on the correlation between electrical and theological properties at the onset of percolation. The experimental results indicate that the elastic load transfer and electrical conductivity are far more sensitive to the onset of percolation than the viscous dissipation in the nanocomposite. Sensitivity of the electrical and rheological percolations to two different solvents used in processing the nanocomposites has also been characterized. C1 Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. Univ Maryland, Dept Chem Engn, College Pk, MD 20742 USA. Univ Maryland, Dept Biomol Engn, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bruck, HA (reprint author), Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. EM bruck@eng.umd.edu RI Cipriano, Bani/G-9239-2011 NR 25 TC 159 Z9 162 U1 4 U2 42 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 2 PY 2007 VL 40 IS 20 BP 7400 EP 7406 DI 10.1021/ma0711792 PG 7 WC Polymer Science SC Polymer Science GA 215YP UT WOS:000249845200046 ER PT J AU Lee, S Chang, J Jaffe, RL Yoon, DY AF Lee, Sanghun Chang, Jaeeon Jaffe, Richard L. Yoon, Do Y. TI Surface and thin film characteristics of poly(tetrafluoroethylene) melts from molecular dynamics simulations SO MACROMOLECULES LA English DT Article ID X-RAY; COMPUTER-SIMULATION; MONTE-CARLO; FRICTION; POLYTETRAFLUOROETHYLENE; PERFLUOROALKANES; INTERFACE; OLIGOMERS; TENSION; ALKANES AB The surface characteristics of thin films of poly(tetrafluoroethylene) (PTFE) melts were investigated by molecular dynamics simulations, employing the recent explicit atomic force field, including partial charges, which was fine-tuned to the experimental PVT data, the chain conformation and the crystal structure (Macromolecules 2003, 36, 533 1). Surface tension was calculated from the virial equation of the pressure tensor, taking into full account of the long-range correction terms, in good agreement with experimental data. Compared with polymethylenes of the same chain length, PTFEs have larger vacuum/liquid interface thicknesses concomitant with lower surface tensions. In the surface region, the chain conformations remain unperturbed, but the chain backbone segments tend to be oriented parallel to the surface whereas the chain-end segments tend to be perpendicular to the surface. As compared with polymethylenes, the orientation of PTFE segments in the surface is found to persist deeper into the film due to the larger intermolecular orientational correlation length in PTFE melts than in polymethylene melts. C1 Korea Inst Adv Study, Sch Computat Sci, Seoul 130722, South Korea. Seoul Natl Univ, Dept Chem, Seoul 151747, South Korea. NASA, Ames Res Ctr, Moffett Field, CA 94305 USA. RP Chang, J (reprint author), Korea Inst Adv Study, Sch Computat Sci, Seoul 130722, South Korea. EM changj@kias.re.kr; dyyoon@snu.ac.kr NR 36 TC 5 Z9 5 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 2 PY 2007 VL 40 IS 20 BP 7407 EP 7412 DI 10.1021/ma071052c PG 6 WC Polymer Science SC Polymer Science GA 215YP UT WOS:000249845200047 ER PT J AU Rembala, R Aziz, S AF Rembala, Richard Aziz, Sarmad TI Increasing the utilization of the ISS mobile servicing system through ground control SO ACTA ASTRONAUTICA LA English DT Article AB On February 24th, 2005 the Mobile Servicing System (MSS) was maneuvred on the International Space Station (ISS) by an operator from the ground for the first time, marking a first in human space flight history. Allowing ground support teams the capability to move the MSS in a manner that satisfies human space flight safety requirements provides an invaluable tool in supporting more efficient utilization of both the MSS and the ISS. Ground control allows for the optimal separation of on-orbit crew and ground functions; thereby redirecting more on-orbit crew time towards other more scientifically rewarding ISS utilization activities. Apart from supporting routine ISS operations, significant benefits will also be gained from ground control to support engineering investigations. One of the "way-of-doing-business" adjustments that was required for the MSS on the ISS over the original robotic manipulator system developed for the Space Shuttle (the "SRMS"), was in the sustaining engineering support function. Many SRMS minor on-orbit anomalies are investigated in detail after the mission is completed and the arm has returned to earth. In the case of the MSS where it remains on-orbit, engineering investigations and performance characterization efforts are more challenging. However, contrary to initial expectations, the challenge in troubleshooting and characterizing the MSS was not because of lack of data or insight into the on-orbit system, but rather due to lack of on-orbit crew time for engineering investigations. This has led to some engineering support teams having to wait up to a year before even straightforward troubleshooting investigations could be scheduled and executed. Ground control affords a more efficient way of characterizing and maintaining the health of the MSS. This paper will describe the utilization challenges the MSS has faced in the past, provide an overview of the MSS ground control capability, and discuss the benefits that are expected to be gained through the implementation of a ground control capability. (c) 2007 Elsevier Ltd. All rights reserved. C1 MDA Space Missions, Brampton, ON, Canada. NASA, Lyndon B Johnson Space Ctr, Canadian Space Agcy, Houston, TX 77058 USA. RP Rembala, R (reprint author), MDA Space Missions, Brampton, ON, Canada. EM richard.rembala@mdacorporation.com; sarmad.aziz1@jsc.nasa.gov NR 0 TC 1 Z9 3 U1 0 U2 3 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 OCT PY 2007 VL 61 IS 7-8 BP 691 EP 698 DI 10.1016/j.actaastro.2006.12.009 PG 8 WC Engineering, Aerospace SC Engineering GA 187SB UT WOS:000247867600016 ER PT J AU Erickson, JK Callas, JL Haldemann, AFC AF Erickson, James K. Callas, John L. Haldemann, Albert F. C. TI The mars exploration rover project: 2005 surface operations results SO ACTA ASTRONAUTICA LA English DT Article AB The twin rovers, Spirit and Opportunity, of the Mars Exploration Rover Project successfully landed on the surface of Mars in January 2004, and began an unprecedented period of surface exploration. Spirit's landing in Gusev Crater, and its subsequent journeys to the Columbia Hills provided ample evidence for the advantages of mobile rovers over fixed landers. Opportunity's "hole in one" landing in the 20m Eagle Crater with the essential evidence to answer the science questions for Meridiani lying meters away underscored the advantage of surface mobility. The project skillfully dealt with a host of challenges after landing, including Flash memory problems and the cold and dim light of Martian winter, to successfully extend the reach of Earth-bound scientists to two new locations on Mars. With the overwhelming success of the prime mission, NASA's decision to continue the MER journey of exploration has achieved results undreamed of before launch. (c) 2007 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Erickson, JK (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. EM James.K.Erickson@jpl.nasa.gov; John.L.Callas@jpl.nasa.gov; Albert.F.Haldemann@jpl.nasa.gov NR 2 TC 1 Z9 1 U1 0 U2 4 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 OCT PY 2007 VL 61 IS 7-8 BP 699 EP 706 DI 10.1016/j.actaastro.2006.12.005 PG 8 WC Engineering, Aerospace SC Engineering GA 187SB UT WOS:000247867600017 ER PT J AU Warren, J Schaefer, S Hirani, AN Desbrun, M AF Warren, Joe Schaefer, Scott Hirani, Anil N. Desbrun, Mathieu TI Barycentric coordinates for convex sets SO ADVANCES IN COMPUTATIONAL MATHEMATICS LA English DT Article DE barycentric coordinates; convex polyhedra; convex sets AB In this paper we provide an extension of barycentric coordinates from simplices to arbitrary convex sets. Barycentric coordinates over convex 2D polygons have found numerous applications in various fields as they allow smooth interpolation of data located on vertices. However, no explicit formulation valid for arbitrary convex polytopes has been proposed to extend this interpolation in higher dimensions. Moreover, there has been no attempt to extend these functions into the continuous domain, where barycentric coordinates are related to Green's functions and construct functions that satisfy a boundary value problem. First, we review the properties and construction of barycentric coordinates in the discrete domain for convex polytopes. Next, we show how these concepts extend into the continuous domain to yield barycentric coordinates for continuous functions. We then provide a proof that our functions satisfy all the desirable properties of barycentric coordinates in arbitrary dimensions. Finally, we provide an example of constructing such barycentric functions over regions bounded by parametric curves and show how they can be used to perform freeform deformations. C1 Rice Univ, Houston, TX 77005 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. EM sschaefe@rice.edu NR 20 TC 72 Z9 72 U1 1 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1019-7168 J9 ADV COMPUT MATH JI Adv. Comput. Math. PD OCT PY 2007 VL 27 IS 3 BP 319 EP 338 DI 10.1007/s10444-005-9008-6 PG 20 WC Mathematics, Applied SC Mathematics GA 202NL UT WOS:000248910200004 ER PT J AU Przekop, A Rizzi, SA AF Przekop, Adam Rizzi, Stephen A. TI Dynamic snap-through of thin-walled structures by a reduced-order method SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 47th Structures, Structural Dynamics, and Materials Conference CY MAY 01-04, 2006 CL Newport, RI SP AIAA, ASME, ASCE, AHS, ASC ID THERMALLY BUCKLED PLATES; RANDOM RESPONSE AB The goal of this investigation is to further develop nonlinear modal numerical simulation methods for application to geometrically nonlinear response of structures exposed to combined high-intensity random pressure fluctuations and thermal loadings. The study is conducted on a flat aluminum beam, which permits a comparison of results obtained by a reduced-order analysis with those obtained from a numerically intensive simulation in physical degrees of freedom. A uniformly distributed thermal loading is first applied to investigate the dynamic instability associated with thermal buckling. A uniformly distributed random loading is added to investigate the combined thermalacoustic response. In the latter case, three types of response characteristics are considered, namely: 1) smallamplitude vibration around one of the two stable buckling equilibrium positions, 2) intermittent snap-through response between the two equilibrium positions, and 3) persistent snap-through response between the two equilibrium positions. For the reduced-order analysis, four categories of modal basis functions are identified, including those having symmetric transverse, antisymmetric transverse, symmetric in-plane, and antisymmetric in-plane displacements. The effect of basis selection on the quality of results is investigated. It is found that despite symmetric geometry, loading, and boundary conditions, the antisymmetric transverse and symmetric in-plane modes participate in the snap-through behavior. C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Aerosp Engn Struct Acoust Branch, Hampton, VA 23681 USA. RP Przekop, A (reprint author), Natl Inst Aerosp, Hampton, VA 23666 USA. NR 26 TC 19 Z9 21 U1 0 U2 7 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 OCT PY 2007 VL 45 IS 10 BP 2510 EP 2519 DI 10.2514/1.26351 PG 10 WC Engineering, Aerospace SC Engineering GA 223CJ UT WOS:000250346900013 ER PT J AU Spalart, PR Rumsey, CL AF Spalart, Philippe R. Rumsey, Christopher L. TI Effective inflow conditions for turbulence models in aerodynamic calculations SO AIAA JOURNAL LA English DT Article AB The selection of inflow values for one- and two-equation turbulence models at boundaries far upstream of an aircraft is considered. Inflow values are distinguished from the ambient values near the body, which may be much smaller because the long approach can allow a deep decay. Ambient values should be selected first, and inflow values that will lead to them after the decay should be second; this is not always possible, especially for the time scale. The decay of turbulence in two-equation models during the approach to the aircraft is shown; in computational fluid dynamics practice, the time scale has often been set too short for this decay to be calculated accurately on typical grids. A simple remedy for both issues is to arrest decay below the chosen ambient values, either by imposing floor values, or preferably by adding weak source terms. A physical justification for overriding the equations in this manner is proposed. Selecting laminar ambient values is easy if the boundary layers are to be tripped, but it is common to seek ambient values that will cause immediate transition in shear layers. This opens up a wide range of values, and selection criteria are discussed. The turbulent Reynolds number, or ratio of eddy viscosity to laminar viscosity has a huge dynamic range that makes it unwieldy; it has been widely misused, particularly by setting upper limits on it. The value of the complete turbulent kinetic energy in a wind tunnel or the atmosphere is also dubious as an input to the model, because its spectrum contains length scales irrelevant to the turbulence in the boundary and shear layers. Concretely, the ambient eddy viscosity must be small enough to preserve potential cores in small geometry features such as flap gaps. The ambient-frequency scale should also be small enough, compared with shear rates in the boundary layer. Specific ranges of values are recommended and demonstrated for airfoil flows. C1 Boeing Commercial Airplane Co, Seattle, WA 98124 USA. NASA, Langley Res Ctr, Computat Aersci Branch, Hampton, VA 23681 USA. RP Spalart, PR (reprint author), Boeing Commercial Airplane Co, Mail Stop 67-LM,POB 3707, Seattle, WA 98124 USA. EM philippe.r.spalart@boeing.com NR 11 TC 69 Z9 76 U1 1 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 OCT PY 2007 VL 45 IS 10 BP 2544 EP 2553 DI 10.2514/1.29373 PG 10 WC Engineering, Aerospace SC Engineering GA 223CJ UT WOS:000250346900017 ER PT J AU Martinez, DA Vailas, AC Vanderby, R Grindeland, RE AF Martinez, D. A. Vailas, A. C. Vanderby, R., Jr. Grindeland, R. E. TI Temporal extracellular matrix adaptations in ligament during wound healing and hindlimb unloading SO AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY LA English DT Article DE collagen; cross-links; hindlimb suspension; real-time quantitative PCR; rat ID MEDIAL COLLATERAL LIGAMENT; SOFT CONNECTIVE-TISSUE; METABOLIC PROPERTIES; PATELLAR TENDON; ACHILLES-TENDON; MESSENGER-RNA; RAT; SUSPENSION; EXERCISE; COLLAGEN AB Previous data from spaceflight studies indicate that injured muscle and bone heal slowly and abnormally compared with ground controls, strongly suggesting that ligaments or tendons may not repair optimally as well. Thus the objective of this study was to investigate the biochemical and molecular gene expression of the collagen extracellular matrix in response to medial collateral ligament (MCL) injury repair in hindlimb unloaded (HLU) rodents. Male rats were assigned to 3- and 7-wk treatment groups with three subgroups each: sham control, ambulatory healing (Amb-healing), and HLU-healing groups. Amb- and HLU-healing animals underwent bilateral surgical transection of their MCLs, whereas control animals were subjected to sham surgeries. All surgeries were performed under isoflurane anesthesia. After 3 wk or 7 wk of HLU, rats were euthanized and MCLs were surgically isolated and prepared for molecular or biochemical analyses. Hydroxyproline concentration and hydroxylysylpyridinoline collagen cross-link contents were measured by HPLC and showed a substantial decrement in surgical groups. MCL tissue cellularity, quantified by DNA content, remained significantly elevated in all HLU-healing groups vs. Amb-healing groups. MCL gene expression of collagen type 1, collagen type 111, collagen type V, fibronectin, decorin, biglycan, lysyl oxidase, matrix metalloproteinase-2, and tissue inhibitor of matrix metalloproteinase-1, measured by real-time quantitative PCR, demonstrated differential expression in the HLU-healing groups compared with Amb-healing groups at both the 3- and 7-wk time points. Together, these data suggest that HLU affects dense fibrous connective tissue wound healing and confirms previous morphological and biomechanical data that HLU inhibits the ligament repair processes. C1 Univ Houston, Biomed Engn Program, Connect Tissue Physiol Lab, Dept Mech Engn,Dept Hlth & Human Performance, Houston, TX 77204 USA. Idaho State Univ, Off President, Pocatello, ID 83209 USA. Univ Wisconsin, Dept Orthoped & Rehabil, Orthoped Res Lab, Madison, WI USA. Univ Wisconsin, Dept Biomed Engn, Madison, WI USA. NASA, Ames Res Ctr, Life Sci Res Div, Moffett Field, CA 94035 USA. RP Martinez, DA (reprint author), Univ Houston, Biomed Engn Program, Connect Tissue Physiol Lab, Dept Mech Engn,Dept Hlth & Human Performance, N207 D Engn Bldg 1, Houston, TX 77204 USA. EM ddam@uh.edu RI Martinez, Daniel/A-5825-2008 NR 45 TC 17 Z9 18 U1 0 U2 5 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0363-6119 J9 AM J PHYSIOL-REG I JI Am. J. Physiol.-Regul. Integr. Comp. Physiol. PD OCT PY 2007 VL 293 IS 4 BP R1552 EP R1560 DI 10.1152/ajpregu.00423.2007 PG 9 WC Physiology SC Physiology GA 219LZ UT WOS:000250088000012 PM 17699562 ER PT J AU Tarsitano, CG Webster, CR AF Tarsitano, Christopher G. Webster, Christopher R. TI Multilaser Herriott cell for planetary tunable laser spectrometers SO APPLIED OPTICS LA English DT Article ID INTERBAND CASCADE LASERS; MULTIPASS ABSORPTION CELLS; CONTINUOUS-WAVE OPERATION; RING-DOWN SPECTROSCOPY; HIGH-POWER; MU-M; TEMPERATURE AB Geometric optics and matrix methods are used to mathematically model multilaser Herriott cells for tunable laser absorption spectrometers for planetary missions. The Herriott cells presented accommodate several laser sources that follow independent optical paths but probe a single gas cell. Strategically placed output holes located in the far mirrors of the Herriott cells reduce the size of the spectrometers. A four-channel Herriott cell configuration is presented for the specific application as the sample cell of the tunable laser spectrometer instrument selected for the sample analysis at Mars analytical suite on the 2009 Mars Science Laboratory mission. (c) 2007 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tarsitano, CG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM christopher.g.tarsitano@aero.org NR 22 TC 22 Z9 24 U1 0 U2 14 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 OCT 1 PY 2007 VL 46 IS 28 BP 6923 EP 6935 DI 10.1364/AO.46.006923 PG 13 WC Optics SC Optics GA 226DA UT WOS:000250566200012 PM 17906720 ER PT J AU Mckay, C AF Mckay, Chris TI Imre friedmann SO ASTROBIOLOGY LA English DT Biographical-Item C1 NASA Ames, Moffett Field, CA 94035 USA. RP Mckay, C (reprint author), NASA Ames, Bldg 245,Rm 21, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 4 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 OCT PY 2007 VL 7 IS 5 BP III EP III DI 10.1089/ast.2007.0611 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 231QL UT WOS:000250964000001 ER PT J AU Ertem, G Hazen, RM Dworkin, JP AF Ertem, Gozen Hazen, Robert M. Dworkin, Jason P. TI Sequence analysis of trimer isomers formed by montmorillonite catalysis in the reaction of binary monomer mixtures SO ASTROBIOLOGY LA English DT Article ID TEMPLATE-DIRECTED SYNTHESIS; RNA OLIGOMERS; ORIGIN; LIFE; 5'-PHOSPHORIMIDAZOLIDE; OLIGONUCLEOTIDES; REGIOSELECTIVITY; RIBONUCLEOTIDES; MINERALS; WORLD AB Oligonucleotides are structurally similar to short RNA strands. Therefore, their formation via non-enzymatic reactions is highly relevant to Gilbert's RNA world scenario (1986) and the origin of life. In laboratory synthesis of oligonucleotides from monomers, it is necessary to remove the water molecules from the reaction medium to shift the equilibrium in favor of oligonucleotide formation, which would have been impossible for reactions that took place in dilute solutions on the early Earth. Model studies designed to address this problem demonstrate that montmorillonite, a phyllosilicate common on Earth and identified on Mars, efficiently catalyzes phosphodiester-bond formation between activated mononucleotides in dilute solutions and produces RNA-like oligomers. The purpose of this study was to examine the sequences and regiospecificity of trimer isomers formed in the reaction of 5'-phosphorimidazolides of adenosine and uridine. Results demonstrated that regiospecificity and sequence specificity observed in the dimer fractions are conserved in their elongation products. With regard to regiospecificity, 61% of the linkages were found to be RNA-like 3',5'- phosphodiester bonds. With regard to sequence specificity, we found that 88% of the linear trimers were hetero-isomers with 61% A- monomer and 39% U-monomer incorporation. These results lend support to Bernal's hypothesis that minerals may have played a significant role in the chemical processes that led to the origin of life by catalyzing the formation of phosphodiester bonds in RNA-like oligomers. C1 NASA, Astrobiol Inst, Geophys Lab, Washington, DC 20546 USA. NASA, Goddard Space Flight Ctr, Astrochem Branch, Greenbelt, MD 20771 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Ertem, G (reprint author), NASA, Astrobiol Inst, Geophys Lab, Washington, DC 20546 USA. EM gertem@arc.nasa.gov RI Dworkin, Jason/C-9417-2012 OI Dworkin, Jason/0000-0002-3961-8997 NR 25 TC 12 Z9 12 U1 0 U2 3 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 OCT PY 2007 VL 7 IS 5 BP 715 EP 722 DI 10.1089/ast.2007.0138 PG 8 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 231QL UT WOS:000250964000002 PM 17963470 ER PT J AU Do, T Morris, M Sahai, R Stapelfeldt, K AF Do, Tuan Morris, Mark Sahai, Raghvendra Stapelfeldt, Karl TI A Spitzer study of the mass-loss histories of three bipolar preplanetary nebulae SO ASTRONOMICAL JOURNAL LA English DT Article DE planetary nebulae : individual ( AFGL 2688, OH 231.8+4.2, IRAS 16342-3814); stars : AGB and post-AGB; stars : mass loss ID CYGNUS EGG NEBULA; PROTOPLANETARY NEBULA; IRAS OBSERVATIONS; DUST SHELL; STAR; OUTFLOW; GRAINS AB We present the results of far- infrared imaging of extended regions around three bipolar preplanetary nebulae, AFGL 2688, OH 231.8+4.2, and IRAS 16342 - 3814, at 70 and 160 mu m with the MIPS instrument on the Spitzer Space Telescope. After a careful subtraction of the point- spread function of the central star from these images, we place constraints on the existence of extended shells and thus on the mass outflow rates as a function of radial distance from these stars. We find no apparent extended emission in AFGL 2688 and OH 231.8+4.2 beyond 100 '' from the central source. In the case of AFGL 2688, this result is inconsistent with a previous report of two extended dust shells made on the basis of ISO observations. We derive upper limits of 2.1 x 10(-7) and 1.0 x 10(-7) M-circle dot yr(-1) for the dust mass- loss rates of AFGL 2688 and OH 231.8, respectively, at 200 '' from each source. In contrast to these two sources, IRAS 16342 - 3814 does show extended emission at both wavelengths, which can be interpreted as a very large dust shell with a radius of similar to 400 '' and a thickness of similar to 100 '', corresponding to 4 and 1 pc, respectively, at a distance of 2 kpc. However, this enhanced emission may also be Galactic cirrus; better azimuthal coverage is necessary for confirmation of a shell. If the extended emission is a shell, it can be modeled, with some assumptions about its dust properties, as enhanced mass outflow at a dust mass outflow rate of 1.5x10(-6) M-circle dot yr(-1) superimposed on a steady outflow with a dust mass outflow rate of 1.5x10(-7) M-circle dot yr(-1). Because of the size of the possible shell, it is likely that this shell has swept up a substantial mass of interstellar gas during its expansion, so these estimates are upper limits to the stellar mass- loss rate. We find a constant color temperature of 32 K throughout the circumstellar envelope of IRAS 16342 - 3814, which is consistent with heating by the interstellar radiation field. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Do, T (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RI Stapelfeldt, Karl/D-2721-2012; OI Do, Tuan/0000-0001-9554-6062 NR 20 TC 6 Z9 6 U1 0 U2 2 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 OCT PY 2007 VL 134 IS 4 BP 1419 EP 1431 DI 10.1086/521553 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215BG UT WOS:000249781800010 ER PT J AU Lynch, DK Russell, RW Rudy, RJ Mazuk, S Venturini, CC Hammel, HB Sykes, MV Puetter, RC Perry, RB AF Lynch, David K. Russell, Ray W. Rudy, Richard J. Mazuk, Stephan Venturini, Catherine C. Hammel, H. B. Sykes, Mark V. Puetter, Richard C. Perry, R. Brad TI Infrared spectra of deimos (1-13 mu m) and phobos (3-13 mu m) SO ASTRONOMICAL JOURNAL LA English DT Article DE infrared : solar system; minor planets; asteroids; planets and satellites : individual ( Deimos, Phobos) ID IRRADIANCE CALIBRATION; ASTEROIDS; SPECTROSCOPY; MICRON AB The 3-13 mu m spectra of Deimos and Phobos were obtained on the nights of 2003 August 19, 20, and 21 UT, within a week of opposition ( August 28). Spectra in the 1.5-2.5 mu m region were taken a few weeks earlier on July 26. Observations were made near greatest elongation for each satellite in order to minimize scattered light from Mars. The L, M, and narrowband N ( 10.2 mu m) magnitudes for Deimos were 7.7 +/- 0.1, 4.9 +/- 0.1, and 0.79 +/- 0.09, respectively. The L, M, and narrowband N ( 10.2 mu m) magnitudes for Phobos were 6.4, 3.8, and -0.52, respectively, all +/-0.07. The 5-12 mu m color temperatures of Deimos and Phobos were 344 +/- 5 and 357 +/- 5 K, respectively, significantly higher than the blackbody thermal equilibrium temperature for either a fast rotator at Mars's heliocentric distance ( 237 K) or a slow rotator ( 282 K). The high brightness temperatures of Deimos and Phobos in the thermal infrared of 310-330 and 320-340 K, respectively, are not understood, but they are somewhat consistent with the high color temperatures. Within the errors, there was little evidence for spectral features indicative of surface composition, although there were some 1-2 sigma variations that warrant further observations. C1 Aerosp Corp, Los Angeles, CA 90009 USA. Planetary Sci Inst, Tucson, AZ 85719 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. NASA, Langley Res Ctr, Sci Support Off, Hampton, VA 23681 USA. RP Lynch, DK (reprint author), Aerosp Corp, MS 266,POB 92957, Los Angeles, CA 90009 USA. EM david.k.lynch@aero.org NR 19 TC 12 Z9 12 U1 0 U2 4 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 OCT PY 2007 VL 134 IS 4 BP 1459 EP 1463 DI 10.1086/519975 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215BG UT WOS:000249781800013 ER PT J AU Hilton, EJ Szkody, P Mukadam, A Mukai, K Hellier, C van Zyl, L Homer, L AF Hilton, Eric J. Szkody, Paula Mukadam, Anjum Mukai, Koji Hellier, Coel van Zyl, Liza Homer, Lee TI XMM-Newton observations of the cataclysmic variable GW Librae SO ASTRONOMICAL JOURNAL LA English DT Article DE stars : dwarf novae; stars : individual (GW Librae); X-rays : stars ID HUBBLE-SPACE-TELESCOPE; X-RAY; WHITE-DWARF; QUIESCENCE; SPECTRA; NOVAE; PRECESSION AB XMM- Newton observations of the accreting, pulsating white dwarf in the quiescent dwarf nova GW Librae were conducted to determine whether the nonradial pulsations present in previous UV and optical data affect the X- ray emission. The nonradial pulsations are evident in the simultaneous Optical Monitor data but are not detected in the X- ray with an upper limit on the pulsation amplitude of 0.092 mag. The best fits to the X- ray spectrum are with a low-temperature diffuse gas model or a multitemperature cooling flow model with a strong O VIII line, similar to other short-period dwarf novae, but with a lower temperature range than evident in normal short- period dwarf novae. The lack of pulsations and the spectrum likely indicate that the boundary layer does not extend to the surface of the white dwarf. C1 Univ Washington, Dept Astron, Seattle, WA 98115 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Keele, Astrophys Grp, Keele ST5 5BG, Staffs, England. Liverpool Community Coll, Liverpool L1 5BG, Merseyside, England. RP Hilton, EJ (reprint author), Univ Washington, Dept Astron, Box 351580, Seattle, WA 98115 USA. EM hilton@astro.washington.edu NR 30 TC 12 Z9 12 U1 0 U2 2 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 OCT PY 2007 VL 134 IS 4 BP 1503 EP 1507 DI 10.1086/521343 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215BG UT WOS:000249781800019 ER PT J AU Johnson, KE Hibbard, JE Gallagher, SC Charlton, JC Hornschemeier, AE Jarrett, TH Reines, AE AF Johnson, Kelsey E. Hibbard, John E. Gallagher, Sarah C. Charlton, Jane C. Hornschemeier, Ann E. Jarrett, Thomas H. Reines, Amy E. TI The infrared properties of Hickson Compact Groups SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : clusters : general; galaxies : evolution; galaxies : interactions; infrared : galaxies ID SPITZER-SPACE-TELESCOPE; STAR-FORMATION; STEPHANS-QUINTET; XMM-NEWTON; VELOCITY DISPERSION; INTRAGROUP MEDIUM; GALAXIES; EMISSION; CLUSTERS; GAS AB Compact groups of galaxies provide a unique environment to study the mechanisms by which star formation occurs amid continuous gravitational encounters. We present 2MASS ( JHK) and Spitzer IRAC ( 3.5-8 mu m) and MIPS ( 24 mu m) observations of a sample of 12 Hickson Compact Groups ( HCGs 2, 7, 16, 19, 22, 31, 42, 48, 59, 61, 62, and 90) that includes a total of 45 galaxies. The infrared colors of the galaxies in this sample span a range of parameter space, and some trends are apparent in the data. The near- infrared colors of the sample galaxies are largely consistent with being dominated by slightly reddened normal stellar populations. There is also some evidence for a K- band excess in a few cases, which likely indicates the presence of hot dust at or near the sublimation temperature associated with active galactic nuclei or star formation activity. Galaxies that have the most significant polycyclic aromatic hydrocarbon and/ or hot dust emission ( as inferred from excess 8 mu m flux) also tend to have larger amounts of extinction and/ or K- band excess and stronger 24 mu m emission, all of which suggest ongoing star formation activity. We separate the 12 HCGs in our sample into three types based on the ratio of the group H I mass to dynamical mass. We find evidence that galaxies in the most gas- rich groups tend to be the most actively star forming. Galaxies in the most gas-poor groups tend to be tightly clustered around a narrow range in colors consistent with the integrated light from a normal stellar population. We interpret these trends as indicating that galaxies in gas- rich groups experience star formation and/ or nuclear actively until their neutral gas is consumed, stripped, or ionized. The galaxies in this sample exhibit a "gap'' between gas- rich and gas- poor groups in infrared color space that is sparsely populated and not seen in the Spitzer First Look Survey sample. This gap may suggest a rapid evolution of galaxy properties in response to dynamical effects. These results suggest that the global properties of the groups and the local properties of the galaxies are connected. C1 Univ Virginia, Dept Astron, Charlottesville, VA 22904 USA. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Lab Xray Astrophys, Greenbelt, MD 20771 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. RP Johnson, KE (reprint author), Natl Radio Astron Observ, 520 Edgemont Rd, Charlottesville, VA 22903 USA. EM kej7a@virginia.edu; jhibbard@nrao.edu; sgall@astro.ucla.edu; charlton@astro.psu.edu; annh@gsfc.nasa.gov; jarrett@ipac.caltech.edu; aer2y@virginia.edu NR 55 TC 55 Z9 55 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 OCT PY 2007 VL 134 IS 4 BP 1522 EP 1543 DI 10.1086/520921 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215BG UT WOS:000249781800022 ER PT J AU Busso, G Cassisi, S Piotto, G Castellani, M Romaniello, M Catelan, M Djorgovski, SG Recio-Blanco, A Renzini, A Rich, MR Sweigart, AV Zoccali, M AF Busso, G. Cassisi, S. Piotto, G. Castellani, M. Romaniello, M. Catelan, M. Djorgovski, S. G. Recio-Blanco, A. Renzini, A. Rich, M. R. Sweigart, A. V. Zoccali, M. TI The peculiar horizontal branch morphology of the Galactic globular clusters NGC 6388 and NGC 6441: new insights from UV observations SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : horizontal-branch; ultraviolet : stars; globular clusters : individual : NGC 6388 globular clusters : individual : NGC 6441 ID STELLAR EVOLUTION DATABASE; HOT FLASHER SCENARIO; NA-O ANTICORRELATION; DOUBLE MAIN-SEQUENCE; RR-LYRAE VARIABLES; BLUE HOOK STARS; OMEGA-CENTAURI; SPECTROSCOPIC ANALYSES; BOLOMETRIC CORRECTIONS; CHEMICAL-COMPOSITION AB Context. In this paper we present multiband optical and UV Hubble Space Telescope photometry of the two Galactic globular clusters NGC 6388 and NGC 6441. Aims. We investigate the properties of their anomalous horizontal branches in different photometric planes in order to shed light on the nature of the physical mechanism(s) responsible for the existence of an extended blue tail and of a slope in the horizontal branch, visible in all the color-magnitude diagrams. Methods. New photometric data have been collected and carefully reduced. Empirical data have been compared with updated stellar models of low-mass, metal-rich, He-burning structures, transformed to the observational plane with appropriate model atmospheres. Results. We have obtained the first UV color-magnitude diagrams for NGC 6388 and NGC 6441. These diagrams confirm previous results, obtained in optical bands, about the presence of a sizeable stellar population of extremely hot horizontal branch stars. At least in NGC 6388, we find a clear indication that at the hot end of the horizontal branch the distribution of stars forms a hook-like feature, closely resembling those observed in NGC 2808 and Omega Cen. We briefly review the theoretical scenarios that have been suggested for interpreting this observational feature. We also investigate the tilted horizontal branch morphology and provide further evidence that supports early suggestions that this feature cannot be interpreted as an effect of differential reddening. We show that a possible solution of the puzzle is to assume that a small fraction - ranging between 10-20% - of the stellar population in the two clusters is strongly helium-enriched (Y similar to 0.40 in NGC 6388 and Y similar to 0.35 in NGC 6441). The occurrence of a spread in the He abundance between the canonical value ( Y similar to 0.26) and the quoted upper limits can significantly help in explaining the "whole" morphology of the horizontal branch and the pulsational properties of the variable stars in the target clusters. C1 Osservatorio Astron Collurania, INAF, I-64100 Teramo, Italy. Univ Kiel, Inst Theoret Phys & Astrophys, D-24114 Kiel, Germany. Univ Padua, Dipartimento Astron, I-35122 Padua, Italy. Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. European So Observ, D-85748 Garching, Germany. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 7820436, Chile. CALTECH, Dept Astron, Pasadena, CA 91125 USA. CNRS, UMR6202, Dpt Cassiopee, Observ Cote Azur, F-06304 Nice 4, France. Osserv Astron Padova, INAF, I-35122 Padua, Italy. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Busso, G (reprint author), Osservatorio Astron Collurania, INAF, Via M Maggini, I-64100 Teramo, Italy. EM busso@oa-teramo.inaf.it; cassisi@oa-teramo.inaf.it; giampaolo.piotto@unipd.it; m.castellani@mporzio.astro.it; mromanie@eso.org; mcatelan@astro.puc.cl; george@astro.caltech.edu; arecio@obs-nice.fr; alvio.renzini@oapd.inaf.it; rmr@astro.ucla.edu; allen.v.sweigart@nasa.gov; mzoccali@astro.puc.cl OI Castellani, Marco/0000-0002-7650-7428; Cassisi, Santi/0000-0001-5870-3735; Piotto, Giampaolo/0000-0002-9937-6387 NR 82 TC 77 Z9 77 U1 0 U2 4 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 OCT PY 2007 VL 474 IS 1 BP 105 EP 119 DI 10.1051/0004-6361:20077806 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 217OV UT WOS:000249958100013 ER PT J AU Porquet, D Uttley, P Reeves, JN Markowitz, A Bianchi, S Grosso, N Miller, L Deluit, S George, IM AF Porquet, D. Uttley, P. Reeves, J. N. Markowitz, A. Bianchi, S. Grosso, N. Miller, L. Deluit, S. George, I. M. TI A 100 ks XMM-Newton view of the Seyfert 1.8 ESO 113-G010 - Discovery of large X-ray variability and study of the FeK alpha line complex SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : Seyfert; galaxies : active; X-rays : galaxies; accretion; accretion disks; quasars : individual : ESO113-G010 ID ACTIVE GALACTIC NUCLEI; RELATIVISTIC SPECTRAL FEATURES; RESONANT AUGER DESTRUCTION; BLACK-HOLE MASS; PG QUASARS; H-I; GALAXIES; MCG-6-30-15; ABSORPTION; LONG AB Context. The Seyfert 1.8 galaxy ESO 113- G010 had been observed for the first time above 2 keV by XMM- Newton during a short exposure (similar to 4 ks) in May 2001. In addition to a significant soft X-ray excess, it showed one of the strongest (in EW) redshifted FeK alpha lines, at 5.4 keV. Aims. We present here a long (100 ks) XMM- Newton follow- up of this source performed in November 2005, in order to study over a longer time- scale its main X- ray properties. Methods. We use both timing analysis (Power Spectra Density analysis, rms spectra, flux- flux analysis) and spectral analysis which mainly focuses on the FeKa line complex. Results. The source was found in a higher/softer time- averaged flux state, and timing analysis of this source reveals strong, rapid variability. The Power Spectral Density (PSD) analysis indicates (at 95% confidence level) a break at 3.7(-1.7)(+1.0) x 10(-4) hz. This cut-off frequency is comparable to those measured in some other rapidly- variable Seyferts, such as MCG - 6- 30- 15 and NGC 4051. From the mass- luminosity- time- scale, we infer that M-BH ranges from 4 x 10(6) - 10(7) M (circle dot) and the source is accreting at or close to the Eddington rate (or even higher). The existing data cannot distinguish between spectral pivoting of the continuum and a two- component origin for the spectral softening, primarily because the data do not span a broad enough flux range. In the case of the two- component model, the fractional o. sets measured in the flux- flux plots increase significantly toward higher energies (similar to what is observed in MCG - 6- 30- 15) as expected if there exists a constant reflection component. Contrary to May 2001, no significant highly redshifted emission line is observed (which might be related to the source flux level), while two narrow emission lines at about 6.5 keV and 7 keV are observed. The S/N is not high enough to establish if the lines are variable or constant. As already suggested by the 2001 observation, no significant constant narrow 6.4 keV FeKa line (EW <= 32 eV) is observed, hence excluding any dominant emission from distant cold matter such as a torus in this Seyfert type 1.8 galaxy. C1 Univ Strasbourg 1, CNRS, Observ Astron Strabsourg, F-67000 Strasbourg, France. Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Keele, Sch Geograph & Phys Sci, Astron Grp, Keele ST5 5BG, Staffs, England. Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. RP Porquet, D (reprint author), Univ Strasbourg 1, CNRS, Observ Astron Strabsourg, 11 Rue Univ, F-67000 Strasbourg, France. EM porquet@astro.u-strasbg.fr RI Bianchi, Stefano/B-4804-2010 OI Bianchi, Stefano/0000-0002-4622-4240 NR 39 TC 8 Z9 8 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 OCT PY 2007 VL 473 IS 1 BP 67 EP 76 DI 10.1051/0004-6361:20077699 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 217OS UT WOS:000249957800008 ER PT J AU Mookerjea, B Sandell, G Stutzki, J Wouterloot, JGA AF Mookerjea, B. Sandell, G. Stutzki, J. Wouterloot, J. G. A. TI SCUBA mapping of outer Galaxy protostellar candidates SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : formation; ISM : general; ISM : Hii regions; ISM : dust; extinction; submillimeter ID H-II REGIONS; MASS STAR-FORMATION; MOLECULAR CLOUD CORES; YOUNG STELLAR OBJECTS; DUST CONTINUUM; IRAS SOURCES; SUBMILLIMETER CONTINUUM; MILLIMETER CONTINUUM; DENSITY STRUCTURE; SILICATE GRAINS AB Aims. We aim to study dust properties of massive star forming regions in the outer Galaxy, in a direction opposite to the Galactic center. Methods. We present observations of six outer Galaxy point sources IRAS 01045+6505, 01420+6401, 05271+3059, 05345+3556, 20222+3541 and 20406+4555, taken with the Submillimeter Common-User Bolometer Array ( SCUBA) on the James Clerk Maxwell Telescope (JCMT) at 450 and 850 mu m. Single temperature greybody models are fitted to the Spectral Energy Distribution of the detected sub-mm cores to derive dust temperature, dust emissivity index and optical depth at 250 mu m. The observed radial intensity profiles of the sub-mm cores were fitted with power laws to derive the indices describing the density distribution. Results. At a resolution of 15 '' all six IRAS point sources show multiple emission peaks. Only four out of fourteen detected sub-mm cores show associated mid-infrared emission. For the sub-mm cores we derive dust temperatures of 32 +/- 5 K and dust emissivity indices between 0.9 and 2.5. The density profiles of the sub-mm cores can be fitted by a single power law distribution with indices -1.5 +/- 0.3, with most cores showing an index of -1.5. This is consistent with most observations of massive star forming regions and supports predictions of models of star formation which consider non-thermal support against gravitational collapse. C1 Univ Cologne, Inst Phys 1, KOSMA, D-50937 Cologne, Germany. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Ames Res Ctr, SOFIA USRA, Moffett Field, CA 94035 USA. Joint Astron Ctr, Hilo, HI 96720 USA. RP Mookerjea, B (reprint author), Univ Cologne, Inst Phys 1, KOSMA, D-50937 Cologne, Germany. EM bhaswati@tifr.res.in NR 62 TC 4 Z9 4 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 OCT PY 2007 VL 473 IS 2 BP 485 EP 491 DI 10.1051/0004-6361:20077878 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 217OT UT WOS:000249957900016 ER PT J AU Beckmann, V Soldi, S Belanger, G Brandt, S Caballero-Garcia, MD De Cesare, G Gehrels, N Grebenev, S Vilhu, O von Kienlin, A Courvoisier, TJL AF Beckmann, V. Soldi, S. Belanger, G. Brandt, S. Caballero-Garcia, M. D. De Cesare, G. Gehrels, N. Grebenev, S. Vilhu, O. von Kienlin, A. Courvoisier, T. J. -L. TI Cygnus X-3 transition from the ultrasoft to the hard state SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : individual : Cyg X-3; X-rays : binaries; X-rays : individuals : Cyg X-3; stars : Wolf-Rayet; X-rays : stars; stars : binaries : close ID X-RAY AB Aims. The nature of Cygnus X-3 is still not understood well. This binary system might host a black hole or a neutron star. Recent observations by INTEGRAL have shown that Cygnus X- 3 was again in an extremely ultrasoft state. Here we present our analysis of the transition from the ultrasoft state, dominated by blackbody radiation at soft X- rays plus non-thermal emission in the hard X- rays, to the low hard state. Methods. INTEGRAL observed Cyg X-3 six times during three weeks in late May and early June 2007. Data from IBIS/ISGRI and JEM-X1 were analysed to show the spectral transition. Results. During the ultrasoft state, the soft X-ray spectrum is well-described by an absorbed (NH = 1.5 x 10(22) cm(-2)) black body model, whereas the X-ray spectrum above 20 keV appears to be extremely low and hard (Gamma similar or equal to 1.7). During the transition, the radio flux rises to a level of > 1 Jy, and the soft X-ray emission drops by a factor of similar to 3, while the hard X- ray emission rises by a factor of similar to 14 and becomes steeper (up to Gamma = 4). Conclusions. The ultrasoft state apparently precedes the emission of a jet, which is apparent in the radio and hard X-ray domain. C1 Integral Sci Data Ctr, CH-1290 Versoix, Switzerland. Univ Geneva, Astron Observ, CH-1290 Sauverny, Switzerland. Univ Maryland Baltimore Cty, CSST, Baltimore, MD 21250 USA. ESAC, Integral Sci Operat Ctr, Madrid, Spain. Tech Univ Denmark, Danish Natl Space Ctr, DK-2100 Copenhagen, Denmark. Lab Astrofis Espacial & Fis Fundamental, LAEFF INTA, Madrid, Spain. INAF, Ist Astrofis Spaziale & Fis Cosm Roma, I-00133 Rome, Italy. Univ Bologna, Dept Astron, I-40127 Bologna, Italy. UPS, CNRS, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. Russian Acad Sci, Space Res Inst, Moscow 117997, Russia. Univ Helsinki Observ, FIN-00014 Helsinki, Finland. Max Planck Inst Extraterr Phys, D-85748 Garching, Germany. RP Beckmann, V (reprint author), Integral Sci Data Ctr, CH-1290 Versoix, Switzerland. EM Volker.Beckmann@obs.unige.ch RI Gehrels, Neil/D-2971-2012; Caballero-Garcia, Maria/D-5659-2017; OI Caballero-Garcia, Maria/0000-0001-7920-4564; De Cesare, Giovanni/0000-0003-0869-7183 NR 24 TC 3 Z9 3 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 OCT PY 2007 VL 473 IS 3 BP 903 EP 905 DI 10.1051/0004-6361:20078160 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 217OU UT WOS:000249958000029 ER PT J AU Jess, DB Andic, A Mathioudakis, M Bloomfield, DS Keenan, FP AF Jess, D. B. Andic, A. Mathioudakis, M. Bloomfield, D. S. Keenan, F. P. TI High-frequency oscillations in a solar active region observed with the RAPID DUAL IMAGER SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE instrumentation : miscellaneous; waves; sun : chromosphere; sun : oscillations; sun : photosphere; sun : sunspots ID RUNNING PENUMBRAL WAVES; MAGNETIC-FLUX TUBES; OSO 8; ACOUSTIC-WAVES; FINE-STRUCTURE; PHASE SPECTRA; QUIET-SUN; H-ALPHA; SI-II; CHROMOSPHERE AB High-cadence, synchronized, multiwavelength optical observations of a solar active region (NOAA 10794) are presented. The data were obtained with the Dunn Solar Telescope at the National Solar Observatory/Sacramento Peak using a newly developed camera system: the RAPID DUAL IMAGER. Wavelet analysis is undertaken to search for intensity related oscillatory signatures, and periodicities ranging from 20 to 370 s are found with significance levels exceeding 95%. Observations in the H-alpha blue wing show more penumbral oscillatory phenomena when compared to simultaneous G-band observations. The H-alpha oscillations are interpreted as the signatures of plasma motions with a mean velocity of 20 km s(-1). The strong oscillatory power over H-a blue-wing and G-band penumbral bright grains is an indication of the Evershed flow with frequencies higher than previously reported. C1 Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland. NASA, Goddard Space Flight Ctr, Solar Phys Lab, Greenbelt, MD 20771 USA. Max Planck Inst Sonnensystemforsch, D-37191 Katlenburg Lindau, Germany. RP Jess, DB (reprint author), Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland. EM djess01@qub.ac.uk RI Bloomfield, Shaun/G-5809-2011; OI Bloomfield, Shaun/0000-0002-4183-9895; Jess, David/0000-0002-9155-8039; Andic, Aleksandra/0000-0002-6428-6162 NR 52 TC 23 Z9 24 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 OCT PY 2007 VL 473 IS 3 BP 943 EP 950 DI 10.1051/0004-6361:20077142 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 217OU UT WOS:000249958000034 ER PT J AU Orton, GS Encrenaz, T Leyrat, C Puetter, R Friedson, AJ AF Orton, G. S. Encrenaz, T. Leyrat, C. Puetter, R. Friedson, A. J. TI Evidence for methane escape and strong seasonal and dynamical perturbations of Neptune's atmospheric temperatures SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE radiative transfer; convection; planets and satellites : individual : Neptune ID STRATOSPHERE; JUPITER; SPECTRA; PLANETS; ETHANE; URANUS AB Aims. We studied the distribution of mid- infrared thermal emission from Neptune to determine the spatial variability of temperatures and the distribution of trace constituents, allowing us to determine the relative strengths of radiation and dynamics in its atmosphere. Methods. Mid- infrared images of the planet were taken at the Very Large Telescope on 1 - 2 September 2006. Results. These images reveal strong inhomogeneities in thermal emission. 17.6 and 18.7- mu m images exhibit strong seasonally elevated south polar temperatures near Neptune's tropopause. These high temperatures allow tropospheric methane, elsewhere cold- trapped at depth, to escape into the stratosphere. Poleward of 70 degrees S, 8.6- and 12.3- mu m emission from stratospheric methane and ethane is enhanced, and a distinct, warm stratospheric feature near 65 - 70 degrees S latitude is rotating with the neutral atmosphere. This feature may result from a localized wave propagating upward from the troposphere. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Paris 07, UPMC, CNRS, Observ Paris,LESIA, F-91925 Meudon, France. Univ Calif San Diego, Ctr Astrophys & Space Sci, CASS 0424, La Jolla, CA 92093 USA. RP Encrenaz, T (reprint author), CALTECH, Jet Prop Lab, MS 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Therese.Encrenaz@obspm.fr NR 28 TC 32 Z9 32 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 EI 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2007 VL 473 IS 1 BP L5 EP L8 DI 10.1051/0004-6361:20078277 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 217OS UT WOS:000249957800002 ER PT J AU Kildea, J Atkins, RW Badran, HM Blaylock, G Bond, IH Bradbury, SM Buckley, JH Carter-Lewis, DA Celik, O Chow, YCK Cui, W Cogan, P Daniel, MK Perez, ID Dowdall, C Duke, C Falcone, AD Fegan, DJ Fegan, SJ Finley, JP Fortson, LF Gall, D Gillanders, GH Grube, J Gutierrez, KJ Hall, J Hall, TA Holder, J Horan, D Hughes, SB Jordan, M Jung, I Kenny, GE Kertzman, M Knapp, J Konopelko, A Kosack, K Krawczynski, H Krennrich, F Lang, MJ LeBohec, S Lloyd-Evans, J Millis, J Moriarty, P Nagai, T Ogden, PA Ong, RA Perkins, JS Petry, D Pizlo, F Pohl, M Quinn, J Quinn, M Rebillot, PF Rose, HJ Schroedter, M Sembroski, GH Smith, AW Syson, A Toner, JA Valcarcel, L Vassiliev, VV Wakely, SP Weekes, TC White, RJ AF Kildea, J. Atkins, R. W. Badran, H. M. Blaylock, G. Bond, I. H. Bradbury, S. M. Buckley, J. H. Carter-Lewis, D. A. Celik, O. Chow, Y. C. K. Cui, W. Cogan, P. Daniel, M. K. Perez, I. de la Calle Dowdall, C. Duke, C. Falcone, A. D. Fegan, D. J. Fegan, S. J. Finley, J. P. Fortson, L. F. Gall, D. Gillanders, G. H. Grube, J. Gutierrez, K. J. Hall, J. Hall, T. A. Holder, J. Horan, D. Hughes, S. B. Jordan, M. Jung, I. Kenny, G. E. Kertzman, M. Knapp, J. Konopelko, A. Kosack, K. Krawczynski, H. Krennrich, F. Lang, M. J. LeBohec, S. Lloyd-Evans, J. Millis, J. Moriarty, P. Nagai, T. Ogden, P. A. Ong, R. A. Perkins, J. S. Petry, D. Pizlo, F. Pohl, M. Quinn, J. Quinn, M. Rebillot, P. F. Rose, H. J. Schroedter, M. Sembroski, G. H. Smith, A. W. Syson, A. Toner, J. A. Valcarcel, L. Vassiliev, V. V. Wakely, S. P. Weekes, T. C. White, R. J. TI The Whipple Observatory 10 m gamma-ray telescope, 1997-2006 SO ASTROPARTICLE PHYSICS LA English DT Article DE gamma-ray astronomy; gamma-ray telescope; atmospheric Cherenkov effect; imaging atmospheric Cherenkov technique; Whipple collaboration; VERITAS; GRANITE; imaging atmospheric Cherenkov telescope ID ATMOSPHERIC CHERENKOV TELESCOPE; IMAGING TELESCOPE; GALACTIC-CENTER; TEV ENERGIES; EMISSION; SYSTEM; ARRAY; DISCOVERY; RADIATION; ASTRONOMY AB Details are presented of the Whipple Observatory's 10 m atmospheric Cherenkov telescope and camera, as it evolved during the period 1997 until 2006. The design of the telescope and camera's optical and electronic systems is discussed together with a detailed description of the four-stage GRANITE (Gamma-RAy New Imaging TElescope) upgrade program, undertaken during the same time period. The objective of the upgrade was to improve the telescope's sensitivity for the detection of very-high-energy gamma-rays. Results from the program are provided and are briefly discussed in the context of the design of VERITAS. (C) 2007 Elsevier B.V. All rights reserved. C1 McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA. Tanta Univ, Dept Phys, Tanta, Egypt. Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA. Univ Leeds, Sch Phys & Astron, Leeds LS2 9JT, W Yorkshire, England. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Univ Coll Dublin, Sch Phys, Dublin, Ireland. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. Grinnell Coll, Dept Phys, Grinnell, IA 50112 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Adler Planetarium & Astron Museum, Dept Astron, Chicago, IL 60605 USA. Natl Univ Ireland Univ Coll Galway, Dept Phys, Galway, Ireland. Univ Arkansas, Dept Phys & Astron, Little Rock, AR 72204 USA. Univ Delaware, Dept Phys & Astron, Sharp Lab, Newark, DE 19716 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Depauw Univ, Dept Phys & Astron, Greencastle, IN 46135 USA. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. Galway Mayo Inst Technol, Dept Phys & Life Sci, Galway, Ireland. Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Kildea, J (reprint author), McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. EM jkildea@gmail.com RI Daniel, Michael/A-2903-2010; Hall, Jeter/E-9294-2015; OI Daniel, Michael/0000-0002-8053-7910; Cui, Wei/0000-0002-6324-5772; Knapp, Johannes/0000-0003-1519-1383; Lang, Mark/0000-0003-4641-4201 NR 46 TC 19 Z9 19 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 EI 1873-2852 J9 ASTROPART PHYS JI Astropart Phys. PD OCT PY 2007 VL 28 IS 2 BP 182 EP 195 DI 10.1016/j.astropartphys.2007.05.004 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 220BW UT WOS:000250132900002 ER PT J AU Ptak, A Mobasher, B Hornschemeier, A Bauer, F Norman, C AF Ptak, Andrew Mobasher, Bahram Hornschemeier, Ann Bauer, Franz Norman, Colin TI X-ray luminosity functions of normal galaxies in the great observatories origins deep survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : formation; surveys; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; STAR-FORMING GALAXIES; FIELD NORTH SURVEY; HIGH-REDSHIFT GALAXIES; PHOTOMETRIC REDSHIFTS; EXTRASOLAR PLANETS; CONFIDENCE-LIMITS; NUMBER COUNTS; EVOLUTION; SOUTH AB We present soft ( 0.5-2 keV) X-ray luminosity functions (XLFs) in the Great Observatories Origins Deep Survey ( GOODS) fields derived for galaxies at z similar to 0.25 and 0.75. SED fitting was used to estimate photometric redshifts and separate galaxy types, resulting in a sample of 40 early-type galaxies and 46 late-type galaxies. We estimate k-corrections for both the X-ray/optical and X-ray/NIR flux ratios, which facilitates the separation of AGNs from the normal/starburst galaxies. We fit the XLFs with a power-law model using both traditional and Markov-Chain Monte Carlo ( MCMC) procedures. A key advantage of the MCMC approach is that it explicitly takes into account upper limits and allows errors on "derived'' quantities, such as luminosity densities, to be computed directly ( i.e., without potentially questionable assumptions concerning the propagation of errors). The slopes of the early-type galaxy XLFs tend to be slightly flatter than the late-type galaxy XLFs, although the effect is significant at only the 90% and 97% levels for z similar to 0.25 and 0.75. The XLFs differ between z < 0. 5 and z > 0. 5 at > 99% significance levels for early-type, late-type, and all (early- and late-type) galaxies. We also fit Schechter and lognormal models to the XLFs, fitting the low- and high-redshift XLFs for a given sample simultaneously assuming only pure luminosity evolution. In the case of lognormal fits, the results of MCMC fitting of the local FIR luminosity function were used as priors for the faint- and bright-end slopes ( similar to "fixing'' these parameters at the FIR values, except here the FIR uncertainty is included). The best-fit values of the change in log L* with redshift were Delta log L* = 0.23 +/- 0.16 dex ( for early- type galaxies) and 0. 34 +/- 0. 12 dex ( for late-type galaxies), corresponding to ( 1 + z) 1. 6 and ( 1 + z) 2.3. These results were insensitive to whether the Schechter or lognormal function was adopted. C1 Johns Hopkins Univ, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, GSFC Lab Xray Astrophys, Greenbelt, MD 20771 USA. Columbia Univ, New York, NY 10027 USA. European So Observ, D-85748 Garching, Germany. RP Ptak, A (reprint author), Johns Hopkins Univ, Homewood Campus, Baltimore, MD 21218 USA. NR 48 TC 32 Z9 32 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 OCT 1 PY 2007 VL 667 IS 2 BP 826 EP 858 DI 10.1086/520824 PN 1 PG 33 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213WY UT WOS:000249699200013 ER PT J AU Shrader, CR Reig, P Kazanas, D AF Shrader, C. R. Reig, P. Kazanas, D. TI Fourier-resolved spectroscopy of 4U 1728-34: New insights into spectral and temporal properties of low-mass X-ray binaries SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion; accretion disks; stars : individual (4U 1728-34); stars : neutron; X-rays : stars; online material : color figures ID QUASI-PERIODIC OSCILLATIONS; BOUNDARY-LAYER EMISSION; COLOR-COLOR DIAGRAM; LUMINOUS LMXBS; NEUTRON-STAR; VARIABILITY; FREQUENCY; OUTBURST; BEHAVIOR; LINE AB Using archival RXTE data we derive the 2-16 keV Fourier-resolved spectra ( FRS) of the atoll source 4U 1728-34 in a sequence of its timing states as its low quasi-periodic oscillation (QPO) frequency spans the range between 6 and 94 Hz. The increase in the QPO frequency accompanies a spectral transition of the source from its island to its banana states. The banana-states' FRS are well fitted by a single blackbody component with kT similar to 2-3 keV depending on the source position in the color-color diagram and the Fourier frequency, thus indicating that this spectral component is responsible for the source variability on these timescales. This result is in approximate agreement with similar behavior exhibited by the Z sources, suggesting that, as in that case, the boundary layer - the likely source of the thermal component - is supported by radiation pressure. Furthermore, it is found that the iron line at similar to 6.6 keV, clearly present in the averaged spectra, not apparent within the limitations of our measurements in the frequency-resolved spectra irrespective of the frequency range. This would indicate that this spectral component exhibits little variability on timescales of 10(-2)-10(2) s. In the island state the single blackbody model proved inadequate, particularly notable in our lowest frequency band (0.008-0.8 Hz). An absorbed power law or an additive blackbody plus hard power-law model was required to obtain a satisfactory fit. Statistics do not allow unambiguous discrimination between these possible scenarios. C1 NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. IESL, Fdn Res & Technol, Iraklion 71110, Crete, Greece. Univ Crete, Dept Phys, Iraklion 71110, Crete, Greece. RP Shrader, CR (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. RI Reig, Pablo/A-1198-2014 OI Reig, Pablo/0000-0002-6446-3050 NR 24 TC 3 Z9 3 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 OCT 1 PY 2007 VL 667 IS 2 BP 1063 EP 1072 DI 10.1086/520832 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213WY UT WOS:000249699200030 ER PT J AU Neugebauer, M Gloeckler, G Gosling, JT Rees, A Skoug, R Goldstein, BE Armstrong, TP Combi, MR Makinen, T McComas, DJ Von Steiger, R Zurbuchen, TH Smith, EJ Geiss, J Lanzerotti, LJ AF Neugebauer, M. Gloeckler, G. Gosling, J. T. Rees, A. Skoug, R. Goldstein, B. E. Armstrong, T. P. Combi, M. R. Maekinen, T. McComas, D. J. Von Steiger, R. Zurbuchen, T. H. Smith, E. J. Geiss, J. Lanzerotti, L. J. TI Encounter of the ulysses spacecraft with the ion tail of comet McNaught SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; plasmas; solar wind ID C/1996 B2 HYAKUTAKE; SOURCE PICKUP IONS; SOLAR-WIND; GIACOBINI-ZINNER; TEMPORAL DECONVOLUTION; EXPLORER ENCOUNTER; HEAVY-IONS; INTERSTELLAR; HYDROGEN; INSTRUMENT AB Comet McNaught was the brightest comet observed from Earth in the last 40 years. For a period of five days in early 2007 February, four instruments on the Ulysses spacecraft directly measured cometary ions and key properties of the interaction of the comet's ion tail with the high-speed solar wind from the polar regions of the Sun. Because of the record-breaking duration of the encounter, the data are unusually comprehensive. O3+ ions were detected for the first time in a comet tail, coexisting with singly charged molecular ions with masses in the range 28-35 amu. The presence of magnetic turbulence and of ions with energies up to similar to 200 keV indicate that at a distance of similar to 1.6 AU from the comet nucleus, the ion tail of comet McNaught had not yet reached equilibrium with the surrounding solar wind. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Colorado, LASP, Boulder, CO 80303 USA. Univ London Imperial Coll Sci Technol & Med, London, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Fundamental Technol LLC, Lawrence, KS 66046 USA. Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. SW Res Inst, San Antonio, TX 78228 USA. Int Space Sci Inst, CH-3012 Bern, Switzerland. Univ Bern, CH-3012 Bern, Switzerland. New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. RP Neugebauer, M (reprint author), Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. EM mneugeb@lpl.Arizona.edu RI Von Steiger, Rudolf/F-6822-2011; Combi, Michael/J-1697-2012 OI Von Steiger, Rudolf/0000-0002-3350-0023; Combi, Michael/0000-0002-9805-0078 NR 29 TC 31 Z9 31 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 OCT 1 PY 2007 VL 667 IS 2 BP 1262 EP 1266 DI 10.1086/521019 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213WY UT WOS:000249699200048 ER PT J AU Deming, D Harrington, J Laughlin, G Seager, S Navarro, SB Bowman, WC Horning, K AF Deming, Drake Harrington, Joseph Laughlin, Gregory Seager, Sara Navarro, Sarah B. Bowman, William C. Horning, Karen TI Spitzer transit and secondary eclipse photometry of GJ 436b SO ASTROPHYSICAL JOURNAL LA English DT Article DE eclipses; infrared : stars; planetary systems; stars : fundamental parameters; stars : individual (GJ 436); stars : low-mass; brown dwarfs ID NEPTUNE-MASS PLANET; M-DWARF GJ-436; EXTRASOLAR PLANET; TIDAL DISSIPATION; SPACE-TELESCOPE; INFRARED RADIUS; HD 189733B; SATELLITES; EVOLUTION; EMISSION AB We report the results of infrared (8 mu m) transit and secondary eclipse photometry of the hot Neptune exoplanet, GJ 436b using Spitzer. The nearly photon-limited precision of these data allows us to measure an improved radius for the planet and to detect the secondary eclipse. The transit (centered at HJD = 2454280.78149 +/- 0.00016) shows the flat-bottomed shape typical of infrared transits, and it precisely defines the planet-to-star 0.00016 radius ratio (), independent of the stellar properties. However, we obtain the planetary radius, 0.0839 +/- 0.0005 as well as the stellar mass and radius, by fitting to the transit curve simultaneously with an empirical mass-radius relation for M dwarfs (M = R). We find R* = M* 0.47 +/- 0.02 in solar units, and R-p = 27,600 +/- 1170 km 4.33 +/- 0.18 R-circle plus). This radius significantly exceeds the radius of a naked ocean planet and requires a gaseous hydrogen-helium envelope. The secondary eclipse occurs at phase, proving a significant orbital 0.587 +/- 0.005 eccentricity (e = 0.150 +/- 0.012). The amplitude of the eclipse [(5.7 +/- 0.8) x 10(-4)] indicates a brightness tem- perature for the planet of T = 712 +/- 36 K. If this is indicative of the planet's physical temperature, it suggests T = 712 +/- 36 the occurrence of tidal heating in the planet. An uncharacterized second planet likely provides ongoing gravitational perturbations that maintain GJ 436b's orbit eccentricity over long timescales. C1 Goddard Space Flight Ctr, Planet Syst Lab, Greenbelt, MD 20771 USA. Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. MIT, Dept Earth Atmospher & Planetary Sci, Dept Phys, Cambridge, MA 02159 USA. Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. RP Deming, D (reprint author), Goddard Space Flight Ctr, Planet Syst Lab, Code 693, Greenbelt, MD 20771 USA. RI Harrington, Joseph/E-6250-2011; OI Harrington, Joseph/0000-0002-8955-8531 NR 27 TC 133 Z9 134 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 OCT 1 PY 2007 VL 667 IS 2 BP L199 EP L202 DI 10.1086/522496 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 213XH UT WOS:000249700100021 ER PT J AU Adelman-McCarthy, JK Agueros, MA Allam, SS Anderson, KSJ Anderson, SF Annis, J Bahcall, NA Bailer-Jones, CAL Baldry, IK Barentine, JC Beers, TC Belokurov, V Berlind, A Bernardi, M Blanton, MR Bochanski, JJ Boroski, WN Bramich, DM Brewington, HJ Brinchmann, J Brinkmann, J Brunner, RJ Budavari, T Carey, LN Carliles, S Carr, MA Castander, FJ Connolly, AJ Cool, RJ Cunha, CE Csabai, I Dalcanton, JJ Doi, M Eisenstein, DJ Evans, ML Evans, NW Fan, XH Finkbeiner, DP Friedman, SD Frieman, JA Fukugita, M Gillespie, B Gilmore, G Glazebrook, K Gray, J Grebel, EK Gunn, JE De Haas, E Hall, PB Harvanek, M Hawley, SL Hayes, J Heckman, TM Hendry, JS Hennessy, GS Hindsley, RB Hirata, CM Hogan, CJ Hogg, DW Holtzman, JA Ichikawa, SI Ichikawa, T Ivezic, Z Jester, S Johnston, DE Jorgensen, AM Juric, M Kauffmann, G Kent, SM Kleinman, SJ Knapp, GR Kniazev, AY Kron, RG Krzesinski, J Kuropatkin, N Lamb, DQ Lampeitl, H Lee, BC Leger, RF Lima, M Lin, H Long, DC Loveday, J Lupton, RH Mandelbaum, R Margon, B Martinez-Delgado, D Matsubara, T McGehee, PM Mckay, TA Meiksin, A Munn, JA Nakajima, R Nash, T Neilsen, EH Newberg, HJ Nichol, RC Nieto-Santisteban, M Nitta, A Oyaizu, H Okamura, S Ostriker, JP Padmanabhan, N Park, C Peoples, J Pier, JR Pope, AC Pourbaix, D Quinn, TR Raddick, MJ Fiorentin, PR Richards, GT Richmond, MW Rix, HW Rockosi, CM Schlegel, DJ Schneider, DP Scranton, R Seljak, U Sheldon, E Shimasaku, K Silvestri, NM Smith, JA Smolcic, V Snedden, SA Stebbins, A Stoughton, C Strauss, MA SubbaRao, M Suto, Y Szalay, AS Szapudi, I Szkody, P Tegmark, M Thakar, AR Tremonti, CA Tucker, DL Uomoto, A Berk, DEV Vandenberg, J Vidrih, S Vogeley, MS Voges, W Vogt, NP Weinberg, DH West, AA White, SDM Wilhite, B Yanny, B Yocum, DR York, DG Zehavi, I Zibetti, S Zucker, DB AF Adelman-McCarthy, Jennifer K. Agueeros, Marcel A. Allam, Sahar S. Anderson, Kurt S. J. Anderson, Scott F. Annis, James Bahcall, Neta A. Bailer-Jones, Coryn A. L. Baldry, Ivan K. Barentine, J. C. Beers, Timothy C. Belokurov, V. Berlind, Andreas Bernardi, Mariangela Blanton, Michael R. Bochanski, John J. Boroski, William N. Bramich, D. M. Brewington, Howard J. Brinchmann, Jarle Brinkmann, J. Brunner, Robert J. Budavari, Tamas Carey, Larry N. Carliles, Samuel Carr, Michael A. Castander, Francisco J. Connolly, A. J. Cool, R. J. Cunha, Carlos E. Csabai, Istvan Dalcanton, Julianne J. Doi, Mamoru Eisenstein, Daniel J. Evans, Michael L. Evans, N. W. Fan, Xiaohui Finkbeiner, Douglas P. Friedman, Scott D. Frieman, Joshua A. Fukugita, Masataka Gillespie, Bruce Gilmore, G. Glazebrook, Karl Gray, Jim Grebel, Eva K. Gunn, James E. De Haas, Ernst Hall, Patrick B. Harvanek, Michael Hawley, Suzanne L. Hayes, Jeffrey Heckman, Timothy M. Hendry, John S. Hennessy, Gregory S. Hindsley, Robert B. Hirata, Christopher M. Hogan, Craig J. Hogg, David W. Holtzman, Jon A. Ichikawa, Shin-Ichi Ichikawa, Takashi Ivezic, Zeljko Jester, Sebastian Johnston, David E. Jorgensen, Anders M. Juric, Mario Kauffmann, Guinevere Kent, Stephen M. Kleinman, S. J. Knapp, G. R. Kniazev, Alexei Yu. Kron, Richard G. Krzesinski, Jurek Kuropatkin, Nikolay Lamb, Donald Q. Lampeitl, Hubert Lee, Brian C. Leger, R. French Lima, Marcos Lin, Huan Long, Daniel C. Loveday, Jon Lupton, Robert H. Mandelbaum, Rachel Margon, Bruce Martinez-Delgado, David Matsubara, Takahiko McGehee, Peregrine M. Mckay, Timothy A. Meiksin, Avery Munn, Jeffrey A. Nakajima, Reiko Nash, Thomas Neilsen, Eric H., Jr. Newberg, Heidi Jo Nichol, Robert C. Nieto-Santisteban, Maria Nitta, Atsuko Oyaizu, Hiroaki Okamura, Sadanori Ostriker, Jeremiah P. Padmanabhan, Nikhil Park, Changbom Peoples, John, Jr. Pier, Jeffrey R. Pope, Adrian C. Pourbaix, Dimitri Quinn, Thomas R. Raddick, M. Jordan Fiorentin, Paola Re Richards, Gordon T. Richmond, Michael W. Rix, Hans-Walter Rockosi, Constance M. Schlegel, David J. Schneider, Donald P. Scranton, Ryan Seljak, Uros Sheldon, Erin Shimasaku, Kazu Silvestri, Nicole M. Smith, J. Allyn Smolcic, Vernesa Snedden, Stephanie A. Stebbins, Albert Stoughton, Chris Strauss, Michael A. SubbaRao, Mark Suto, Yasushi Szalay, Alexander S. Szapudi, Istvan Szkody, Paula Tegmark, Max Thakar, Aniruddha R. Tremonti, Christy A. Tucker, Douglas L. Uomoto, Alan Berk, Daniel E. Vanden Vandenberg, Jan Vidrih, S. Vogeley, Michael S. Voges, Wolfgang Vogt, Nicole P. Weinberg, David H. West, Andrew A. White, Simon D. M. Wilhite, Brian Yanny, Brian Yocum, D. R. York, Donald G. Zehavi, Idit Zibetti, Stefano Zucker, Daniel B. TI The Fifth Data Release of the Sloan Digital Sky Survey SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE atlases; catalogs; surveys ID SPECTROSCOPIC TARGET SELECTION; GALAXY REDSHIFT SURVEY; SURVEY QUASAR CATALOG; PHOTOMETRIC REDSHIFTS; SURFACE BRIGHTNESS; SDSS; SAMPLE; SYSTEM; FIELD; CALIBRATION AB This paper describes the Fifth Data Release (DR5) of the Sloan Digital Sky Survey (SDSS). DR5 includes all survey quality data taken through 2005 June and represents the completion of the SDSS-I project (whose successor, SDSS-II, will continue through mid-2008). It includes five-band photometric data for 217 million objects selected over 8000 deg(2) and 1,048,960 spectra of galaxies, quasars, and stars selected from 5713 deg2 of that imaging data. These numbers represent a roughly 20% increment over those of the Fourth Data Release; all the data from previous data releases are included in the present release. In addition to "standard'' SDSS observations, DR5 includes repeat scans of the southern equatorial stripe, imaging scans across M31 and the core of the Perseus Cluster of galaxies, and the first spectroscopic data from SEGUE, a survey to explore the kinematics and chemical evolution of the Galaxy. The catalog database incorporates several new features, including photometric redshifts of galaxies, tables of matched objects in overlap regions of the imaging survey, and tools that allow precise computations of survey geometry for statistical investigations. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Apache Point Observ, Sunspot, NM 88349 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. Johns Hopkins Univ, Dept Phys & Astron, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Michigan State Univ, Joint Inst Nucl Astrophys, E Lansing, MI 48824 USA. Univ Cambridge, Astron Inst, Cambridge CB3 0HA, England. NYU, Dept Phys, Ctr Cosmol & Particle Phys, New York, NY 10003 USA. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. Univ Porto, Ctr Astrofis, P-4150762 Oporto, Portugal. Univ Illinois, Dept Astron, Urbana, IL 61801 USA. CSIC, Inst Estudis Espacials Catalunya, E-08034 Barcelona, Spain. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA. Eotvos Lorand Univ, Dept Phys Complex Syst, H-1518 Budapest, Hungary. Univ Tokyo, Sch Sci, Astron Inst, Mitaka, Tokyo 1810015, Japan. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. Microsoft Res, San Francisco, CA 94105 USA. Univ Basel, Astron Inst, Dept Phys & Astron, CH-4102 Basel, Switzerland. York Univ, Dept Phys & Astron, N York, ON M3J 1P3, Canada. Catholic Univ Amer, Dept Phys, Inst Astron & Computat Sci, Washington, DC 20064 USA. USN Observ, Washington, DC 20392 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20392 USA. Inst Adv Study, Princeton, NJ 08540 USA. New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. Natl Astron Observ, Tokyo 1818588, Japan. Tohoku Univ, Astron Inst, Aoba Ku, Sendai, Miyagi 9808578, Japan. Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Portsmouth, Inst Cosmol & Gravit, Portsmouth PO1 2EG, Hants, England. Gemini Observ, Hilo, HI 96720 USA. CALTECH, Pasadena, CA 91125 USA. Los Alamos Natl Lab, ISR 4, Los Alamos, NM 87545 USA. Max Planck Inst Astrophys, D-85748 Garching, Germany. Natl Astron Observ Japan, Subaru Telescope, Hilo, HI 96720 USA. Akad Pedogogicznaw Krakowie, Obserwatorium Astron Suhorze, PL-30084 Krakow, Poland. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Gatan Inc, Pleasanton, CA 94588 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Univ Sussex, Ctr Astron, Brighton BN1 9QJ, E Sussex, England. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Spain. Nagoya Univ, Dept Phys & Astrophys, Nagoya, Aichi 4648602, Japan. Los Alamos Natl Lab, AOT IC, Los Alamos, NM 87545 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Edinburgh, Royal Observ, Scottish Univ Phys Alliance, Edinburgh EH9 3HJ, Midlothian, Scotland. Univ Edinburgh, Royal Observ, Astron Inst, Edinburgh EH9 3HJ, Midlothian, Scotland. USN Observ, Flagstaff, AZ 86001 USA. Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Univ Tokyo, Dept Astron, Tokyo 1130033, Japan. Univ Tokyo, Res Ctr Early Universe, Bunkyo Ku, Tokyo 1130033, Japan. Princeton Univ, Joseph Henry Labs, Princeton, NJ 08544 USA. Korea Inst Adv Study, Seoul 130722, South Korea. Univ Libre Bruxelles, Inst Astron & Astrophys, FNRS, B-1050 Brussels, Belgium. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Austin Peay State Univ, Dept Phys & Astron, Clarksville, TN 37040 USA. Alder Planetarium & Astron Museum, Chicago, IL 60605 USA. Univ Tokyo, Dept Phys, Tokyo 1130033, Japan. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Case Western Reserve Univ, Dept Astron, Cleveland, OH 44106 USA. RP Adelman-McCarthy, JK (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. RI Lima, Marcos/E-8378-2010; Padmanabhan, Nikhil/A-2094-2012; Margon, Bruce/B-5913-2012; Csabai, Istvan/F-2455-2012; McKay, Timothy/C-1501-2009; West, Andrew/H-3717-2014; Agueros, Marcel/K-7998-2014; Mandelbaum, Rachel/N-8955-2014; Brinchmann, Jarle/M-2616-2015; Glazebrook, Karl/N-3488-2015; OI Csabai, Istvan/0000-0001-9232-9898; Hogg, David/0000-0003-2866-9403; McKay, Timothy/0000-0001-9036-6150; Agueros, Marcel/0000-0001-7077-3664; Mandelbaum, Rachel/0000-0003-2271-1527; Brinchmann, Jarle/0000-0003-4359-8797; Glazebrook, Karl/0000-0002-3254-9044; Baldry, Ivan/0000-0003-0719-9385 NR 53 TC 538 Z9 542 U1 2 U2 28 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 EI 1538-4365 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD OCT PY 2007 VL 172 IS 2 BP 634 EP 644 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 212HY UT WOS:000249588000005 ER PT J AU Kellermann, KI Kovalev, YY Lister, ML Homan, DC Kadler, M Cohen, MH Ros, E Zensus, JA Vermeulen, RC Aller, MF Aller, HD AF Kellermann, K. I. Kovalev, Y. Y. Lister, M. L. Homan, D. C. Kadler, M. Cohen, M. H. Ros, E. Zensus, J. A. Vermeulen, R. C. Aller, M. F. Aller, H. D. TI Doppler boosting, superluminal motion, and the kinematics of AGN jets SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 5th Stromlo Symposium on Disks, Winds and Jets - From Planets to Quasars CY DEC 03-08, 2006 CL Canberra, AUSTRALIA DE galaxies : active; galaxies : jets; galaxies : individual (M87); quasars : general; radio continuum : galaxies; acceleration of particles ID ACTIVE GALACTIC NUCLEI; BASE-LINE ARRAY; RADIO-SOURCES; VLBA EXPERIMENTS; BL LACERTAE; M87 JET; QUASARS; SPECTRA; VARIABILITY; MOJAVE AB We discuss results from a decade long program to study the fine-scale structure and the kinematics of relativistic AGN jets with the aim of better understanding the acceleration and collimation of the relativistic plasma forming AGN jets. From the observed distribution of brightness temperature, apparent velocity, flux density, time variability, and apparent luminosity, the intrinsic properties of the jets including Lorentz factor, luminosity, orientation, and brightness temperature are discussed. Special attention is given to the jet in M87, which has been studied over a wide range of wavelengths and which, due to its proximity, is observed with excellent spatial resolution. Most radio jets appear quite linear, but we also observe curved non-linear jets and non-radial motions. Sometimes, different features in a given jet appear to follow the same curved path but there is evidence for ballistic trajectories as well. The data are best fit with a distribution of Lorentz factors extending up to gamma similar to 30 and intrinsic luminosity up to similar to 10(26) WHz(-1). In general, gamma-ray quasars may have somewhat larger Lorentz factors than non gamma-ray quasars. Initially the observed brightness temperature near the base of the jet extend up to similar to 5 x 10(13) K which is well in excess of the inverse Compton limit and corresponds to a large excess of particle energy over magnetic energy. However, more typically, the observed brightness temperatures are similar to 2 x 10(11) K, i.e., closer to equipartition. C1 [Kellermann, K. I.] Natl Radio Astron Observ, Charlottesville, VA 22903 USA. [Kovalev, Y. Y.; Ros, E.; Zensus, J. A.] Max Planck Inst Radioastron, D-53121 Bonn, Germany. [Kovalev, Y. Y.] Astro Space Ctr, Inst Phys, RU-117997 Moscow, Russia. [Lister, M. L.] Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. [Homan, D. C.] Denison Univ, Dept Phys & Astron, Granville, OH 43023 USA. [Kadler, M.] NASA, Goddard Space Flight Ctr, Div Astrophys Sci, Greenbelt, MD 20771 USA. [Cohen, M. H.] CALTECH, Dept Astron, Pasadena, CA 91125 USA. [Vermeulen, R. C.] Netherlands Fdn Res Astron, NL-7990 AA Dwingeloo, Netherlands. [Aller, M. F.; Aller, H. D.] Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. RP Kellermann, KI (reprint author), Natl Radio Astron Observ, 520 Edgemont Rd, Charlottesville, VA 22903 USA. EM kkellerm@nrao.edu; ykovalev@mpifr-bonn.mpg.de; mlister@physics.purdue.edu; homand@denison.edu; mkadler@milkyway.gsfc.nasa.gov; mhc@astro.caltech.edu; ros@mpifr-bonn.mpg.de; azensus@mpifr-bonn.mpg.de; rvermeulen@astron.nl; mfa@umich.edu; haller@umich.edu RI Kovalev, Yuri/J-5671-2013; OI Kovalev, Yuri/0000-0001-9303-3263; Ros, Eduardo/0000-0001-9503-4892; Kadler, Matthias/0000-0001-5606-6154 NR 40 TC 18 Z9 18 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0004-640X EI 1572-946X J9 ASTROPHYS SPACE SCI JI Astrophys. Space Sci. PD OCT PY 2007 VL 311 IS 1-3 BP 231 EP 239 DI 10.1007/s10509-007-9622-5 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219VD UT WOS:000250115400031 ER PT J AU Sambruna, RM AF Sambruna, Rita M. TI Multiwavelength observations of blazars: a summary SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 5th Stromlo Symposium on Disks, Winds and Jets - From Planets to Quasars CY DEC 03-08, 2006 CL Canberra, AUSTRALIA DE blazars : general; radio-loud AGN; Blazars : jets ID BL LACERTAE OBJECTS; ENERGY GAMMA-RAYS; PKS 2155-304; EMISSION; SEQUENCE; QUASARS; FLARES; LAC AB Because of their broad-band nature, multiwavelength observations of blazars are crucial to constrain the emission mechanisms, structure, and physical quantities of the inner jet on parsec and sub-parsec scales. Here I briefly review selected multiwavelength observations of blazars with a particular emphasis on sources detected at GeV and TeV gamma-rays. Their properties are discussed in the frame of the blazar "luminosity sequence". C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sambruna, RM (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM Rita.M.Sambruna@nasa.gov NR 31 TC 3 Z9 3 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 OCT PY 2007 VL 311 IS 1-3 BP 241 EP 246 DI 10.1007/s10509-007-9581-x PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219VD UT WOS:000250115400032 ER PT J AU Hardee, P Mizuno, Y Nishikawa, KI AF Hardee, Philip Mizuno, Yosuke Nishikawa, Ken-Ichi TI GRMHD/RMHD simulations & stability of magnetized spine-sheath relativistic jets SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 5th Stromlo Symposium on Disks, Winds and Jets - From Planets to Quasars CY DEC 03-08, 2006 CL Canberra, AUSTRALIA DE galaxies : jets; gamma rays : bursts; ISM : jets and outflows; methods : analytical; MHD; relativity; instabilities ID MAGNETICALLY DRIVEN ACCRETION; VELOCITY IONIZED OUTFLOW; ELECTRON-POSITRON JET; DOUBLE RADIO-SOURCES; GAMMA-RAY BURSTS; BLACK-HOLE; MAGNETOHYDRODYNAMIC SIMULATIONS; QUASAR; MODEL; PROPAGATION AB A new general relativistic magnetohydrodynamics GRMHD) code "RAISHIN" used to simulate jet generation by rotating and non-rotating black holes with a geometrically thin Keplarian accretion disk finds that the jet develops a spine-sheath structure in the rotating black hole case. Spine-sheath structure and strong magnetic fields significantly modify the Kelvin-Helmholtz (KH) velocity shear driven instability. The RAISHIN code has been used in its relativistic magnetohydrodynamic (RMHD) configuration to study the effects of strong magnetic fields and weakly relativistic sheath motion, c/2, on the KH instability associated with a relativistic,gamma = 2.5, jet spine- interaction. In the simulations sound speeds up to similar to c/root 3 and Alfven wave speeds up to similar to 0.56c are considered. Numerical simulation results are compared to theoretical predictions from a new normal mode analysis of the RMHD equations. Increased stability of a weakly magnetized system resulting from c/2 sheath speeds and stabilization of a strongly magnetized system resulting from c/2 sheath speeds is found. C1 Univ Alabama, Tuscaloosa, AL 35487 USA. Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. NASA, Marshall Space Flight Ctr, Huntsville, AL 35805 USA. Univ Alabama, Huntsville, AL 35805 USA. RP Hardee, P (reprint author), Univ Alabama, Tuscaloosa, AL 35487 USA. EM phardee@bama.ua.edu RI Mizuno, Yosuke/D-5656-2017 OI Mizuno, Yosuke/0000-0002-8131-6730 NR 37 TC 11 Z9 11 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 OCT PY 2007 VL 311 IS 1-3 BP 281 EP 286 DI 10.1007/s10509-007-9529-1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219VD UT WOS:000250115400038 ER PT J AU Dopita, MA Reuland, M van Breugel, W de Vries, W Stanford, SA Rotgering, H Miley, G Venemans, B Spinrad, H Dawson, S Dey, A Lacy, M Stern, D Bunker, A AF Dopita, Michael A. Reuland, Michiel van Breugel, Wil de Vries, Wim Stanford, S. A. Rottgering, Huub Miley, George Venemans, Bram Spinrad, Hy Dawson, Steve Dey, Arjun Lacy, Mark Stern, Daniel Bunker, Andrew TI Halo ejection in distant radio galaxies: jet feedback in massive galaxy formation SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 5th Stromlo Symposium on Disks, Winds and Jets - From Planets to Quasars CY DEC 03-08, 2006 CL Canberra, AUSTRALIA DE galaxies : active; galaxies : formation; galaxies : high-redshift; galaxies : individual (4C 41.17, 4C 60.07, B2 0902+34); quasars : emission lines ID PRESSURE-DOMINATED PHOTOIONIZATION; EMISSION-LINE GAS; HIGH-REDSHIFT; DEEP SPECTROSCOPY; STAR-FORMATION; BLACK-HOLES; 4C 41.17; SHOCKS; DUSTY; POWER AB We present results from a Keck optical and near IR spectroscopic study of the giant emission line halos of the z > 3 High Redshift Radio Galaxies (HiZRGs) 4C 41.17, 4C 60.07 and B2 0902+34. The outer regions of these halos show quiet kinematics with typical velocity dispersions of a few hundred km s(-1) and velocity shears consistent with rotation. The inner regions contain shocked, clumpy cocoons of gas closely associated with the radio lobes with disturbed kinematics and expansion velocities and/or velocity dispersions > 1000 km s(-1). We also find evidence for the ejection of chemically enriched material in 4C 41.17 up to a distance of similar to 60 kpc along the radio-axis. We infer that these HiZRGs are undergoing a final jet-induced phase of star formation with the ejection of most of their interstellar medium before evolving to become "red and dead" Elliptical galaxies. C1 Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Merced, Merced, CA 95344 USA. Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. CALTECH, SIRTF Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. RP Dopita, MA (reprint author), Australian Natl Univ, Res Sch Astron & Astrophys, Cotter Rd, Weston, ACT 2611, Australia. EM michael.dopita@anu.ed.au RI Dopita, Michael/P-5413-2014 OI Dopita, Michael/0000-0003-0922-4986 NR 32 TC 3 Z9 3 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0004-640X J9 ASTROPHYS SPACE SCI JI Astrophys. Space Sci. PD OCT PY 2007 VL 311 IS 1-3 BP 305 EP 309 DI 10.1007/s10509-007-9538-0 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219VD UT WOS:000250115400041 ER PT J AU Schwartz, DA Harris, DE Landt, H Siemiginowska, A Marshall, HL Gelbord, JM Perlman, ES Georganopoulos, M Birkinshaw, M Worrall, DM Cheung, CC Stawarz, L Jorstad, SG Marscher, AP Uchiyama, Y Urry, CM AF Schwartz, D. A. Harris, D. E. Landt, H. Siemiginowska, A. Marshall, H. L. Gelbord, J. M. Perlman, E. S. Georganopoulos, M. Birkinshaw, M. Worrall, D. M. Cheung, C. C. Stawarz, L. Jorstad, S. G. Marscher, A. P. Uchiyama, Y. Urry, C. M. TI The X-ray jet and lobes of PKS 1354+195 (=4C 19.44) SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 5th Stromlo Symposium on Disks, Winds and Jets - From Planets to Quasars CY DEC 03-08, 2006 CL Canberra, AUSTRALIA DE (Galaxies : ) quasars : individual (4C 19.44, PKS 1354+135); galaxies : jets; X-rays : individual (4C 19.44, PKS 1354+135); radio continuum : general; magnetic fields ID ACTIVE GALACTIC NUCLEI; HUBBLE-SPACE-TELESCOPE; EXTENDED RADIO JETS; CHANDRA OBSERVATIONS; OBJECTS AB We present a Chandra image of the quasar, jet, and lobes of PKS 1354+195 (=4C 19.44). The radio jet is 18 arcsec long, and appears to be very straight. The length gives many independent spatial resolution elements in the Chandra image while the straightness implies that the geometrical factors are constant along the jet although their values are uncertain. We also have 4 frequency radio images with half to one arcsecond angular resolution, and use HST and Spitzer data to study the broad band spectral energy distributions. The X-ray and radio spectra are both consistent with a spectrum f(nu) alpha nu(-0.7) stop for the integrated jet. Using that spectral index, the model of inverse Compton scattering of electrons on the cosmic microwave background (IC/CMB) gives magnetic field strengths and Doppler factors that are relatively constant along the jet. Extended X-ray emission is evident in the direction of the otherwise unseen counter-jet. X-ray emission continues past the radio jet to the South, and is detected within both the southern and northern radio lobes. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Bristol, Dept Phys, Bristol, Avon, England. MIT, Kavli Inst, Cambridge, MA USA. Univ Durham, Dept Phys, Durham, England. Univ Maryland, Baltimore, MD USA. Florida Inst Technol, Melbourne, FL USA. GSFC, Greenbelt, MD USA. Stanford Univ, KIPAC, Stanford, CA 94305 USA. NRAO, Charlottesville, VA USA. Boston Univ, IAR, Boston, MA 02215 USA. ISAS, JAXA, Sagamihara, Kanagawa, Japan. Yale Ctr Astron & Astrophys, New Haven, CT USA. RP Schwartz, DA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM das@cfa.harvard.edu RI Urry, Claudia/G-7381-2011; Jorstad, Svetlana/H-6913-2013 OI Urry, Claudia/0000-0002-0745-9792; Jorstad, Svetlana/0000-0001-9522-5453 NR 12 TC 4 Z9 4 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0004-640X J9 ASTROPHYS SPACE SCI JI Astrophys. Space Sci. PD OCT PY 2007 VL 311 IS 1-3 BP 341 EP 345 DI 10.1007/s10509-007-9548-y PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219VD UT WOS:000250115400047 ER PT J AU Mecikalski, JR Feltz, WF Murray, JJ Johnson, DB Bedka, KM Bedka, ST Wimmers, AJ Pavolonis, M Berendies, TA Haggerty, J Minnis, P Bernstein, B Williams, E AF Mecikalski, John R. Feltz, Wayne F. Murray, John J. Johnson, David B. Bedka, Kristopher M. Bedka, Sarah T. Wimmers, Anthony J. Pavolonis, Michael Berendies, Todd A. Haggerty, Julie Minnis, Pat Bernstein, Ben Williams, Earle TI Aviation applications for satellite-based observations of cloud properties, convection initiation, in-flight icing, turbulence, and volcanic ash SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID TROPOSPHERIC WINDS; IMAGERY; WATER; CLASSIFICATION; HUMIDITY; 6.7-MU-M; PRODUCT; CHANNEL; CUMULUS; SYSTEM AB Advanced Satellite Aviation Weather Products (ASAP) was jointly initiated by the NASA Applied Sciences Program and the NASA Aviation Safety and Security Program in 2002. The initiative provides a valuable bridge for transitioning new and existing satellite information and products into Federal Aviation Administration (FAA) Aviation Weather Research Program (AWRP) efforts to increase the safety and efficiency of the airspace system. The ASAP project addresses hazards such as convective weather, turbulence (clear air and cloud induced), icing, and volcanic ash, and is particularly applicable in extending the monitoring of weather over data-sparse areas, such as the oceans and other observationally remote locations. ASAP research is conducted by scientists from NASA, the FAA AWRP's Product Development Teams (PDT), NOAA, and the academic research community. In this paper we provide a summary of activities since the inception of ASAP that emphasize the use of current-generation satellite technologies toward observing and mitigating specified aviation hazards. A brief overview of future ASAP goals is also provided in light of the next generation of satellite sensors (e.g., hyperspectral; high spatial resolution) to become operational in the 2007-18 time frame. C1 Univ Alabama, Dept Atmospher Sci, Huntsville, AL USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. NASA, Langley Res Ctr, Chem & Dynam Branch, Hampton, VA 23665 USA. NESDIS, NOAA, Adv Satellite Prod Branch, Madison, WI USA. MIT, Cambridge, MA 02139 USA. RP Mecikalski, JR (reprint author), Univ Alabama, Natl Space Sci & Technol Ctr, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM john.mecikalski@nsstc.uah.edu RI Pavolonis, Mike/F-5618-2010; Minnis, Patrick/G-1902-2010 OI Pavolonis, Mike/0000-0001-5822-219X; Minnis, Patrick/0000-0002-4733-6148 NR 64 TC 20 Z9 22 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 2007 VL 88 IS 10 BP 1589 EP + DI 10.1175/BAMS-88-10-1589 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 224EO UT WOS:000250430500022 ER PT J AU Schubert, S Koster, R Hoerling, M Seager, R Lettenmaier, D Kumar, A Gutzler, D AF Schubert, Siegfried Koster, Randal Hoerling, Martin Seager, Richard Lettenmaier, Dennis Kumar, Arun Gutzler, David TI Predicting drought on seasonal-to-decadal time scales SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material C1 NASA, Goddard Space Flight Ctr, Global Modelling & Assimilat Off, Earth Sun Explorat Div, Greenbelt, MD 20771 USA. Earth Syst Res Lab, Boulder, CO USA. Columbia Univ, Earth Observ, Palisades, NY USA. Univ Washington, Seattle, WA 98195 USA. NCEP, NWS, NOAA, Climate Predict Ctr, Camp Springs, MD USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM USA. RP Schubert, S (reprint author), NASA, Goddard Space Flight Ctr, Global Modelling & Assimilat Off, Earth Sun Explorat Div, Greenbelt, MD 20771 USA. EM siegfried.d.schubert@nasa.gov RI Koster, Randal/F-5881-2012; lettenmaier, dennis/F-8780-2011; OI Koster, Randal/0000-0001-6418-6383; lettenmaier, dennis/0000-0003-3317-1327; Gutzler, David/0000-0001-6476-8412 NR 2 TC 20 Z9 20 U1 0 U2 10 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 2007 VL 88 IS 10 BP 1625 EP 1630 DI 10.1175/BAMS-88-10-1625 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 224EO UT WOS:000250430500024 ER PT J AU Zak, M AF Zak, Michail TI From quantum entanglement to mirror neuron SO CHAOS SOLITONS & FRACTALS LA English DT Article ID DYNAMICS AB it is proposed that two fundamental phenomena: quantum entanglement in physics, and mirror neuron in biopsychology, can be described by using the same mathematical formalism, namely, the feedback from the Liouville equation to equation of motion. (c) 2006 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Adv Comp Algorithms & IVHM Grp, Pasadena, CA 91109 USA. RP Zak, M (reprint author), CALTECH, Jet Prop Lab, Adv Comp Algorithms & IVHM Grp, 4800 Oak Grove Dr,M-S 126-347, Pasadena, CA 91109 USA. EM Michail.Zak@jpl.nasa.gov NR 17 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0960-0779 J9 CHAOS SOLITON FRACT JI Chaos Solitons Fractals PD OCT PY 2007 VL 34 IS 2 BP 344 EP 359 DI 10.1016/j.chaos.2006.03.087 PG 16 WC Mathematics, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 175OE UT WOS:000247022100016 ER PT J AU Stothers, R AF Stothers, Richard TI UNIDENTIFIED FLYING OBJECTS IN CLASSICAL ANTIQUITY SO CLASSICAL JOURNAL LA English DT Article AB A combined historical and scientific approach is applied to ancient reports of what might today be called unidentified flying objects (UFOs). Many conventionally explicable phenomena can be weeded out, leaving a small residue of puzzling reports. These fall neatly into the same categories as modern UFO reports, suggesting that the UFO phenomenon, whatever it may be due to, has not changed much over two millennia. C1 [Stothers, Richard] NASA, Washington, DC 20546 USA. RP Stothers, R (reprint author), NASA, Washington, DC 20546 USA. NR 42 TC 1 Z9 1 U1 0 U2 0 PU CLASSICAL ASSOC MIDDLE WEST SOUTH, INC PI ASHLAND PA PO BOX 5005, RANDOLPH-MACON COLL, ASHLAND, VA 23005-5505 USA SN 0009-8353 EI 2327-5812 J9 CLASSICAL J JI Class. J. PD OCT-NOV PY 2007 VL 103 IS 1 BP 79 EP 92 PG 14 WC Classics SC Classics GA V45HO UT WOS:000209807900005 ER PT J AU Feynman, J Ruzmaikin, A AF Feynman, Joan Ruzmaikin, Alexander TI Climate stability and the development of agricultural societies SO CLIMATIC CHANGE LA English DT Article ID ICE-CORE; OSCILLATION SIGNATURE; PHYTOLITH EVIDENCE; GREENLAND ICE; ATLANTIC; DOMESTICATION; VARIABILITY; MAIZE; TIME; SEA AB Although Modern Man had developed long before the migration from Africa began similar to 55,000 years ago no agricultural societies developed until about similar to 10,000 years ago. In the next 5,000 years agricultures developed independently in at least six regions of the world. It is virtually certain that it was not a chance occurrence that so many new agricultures appeared in the same 5,000 years. What inhibited agriculture world wide for 44,000 years and what changed similar to 10,000 years ago? Here we suggest that a major factor influencing the development of agricultural societies was climate stability. From the experience of four cultures we estimate that the development of agriculture needed similar to 2,000 years of climate free from significant climate variations on time scales of a few centuries. Using the Empirical Mode Decomposition technique specifically designed to exhibit the time history of the amplitude of variations in non-stationary time series such as climate proxy records, we find that between 50,000 years ago and the termination of the Younger Dryas similar to 11,600 years ago there was probably no time span as long as 2,000 years that was free of relatively large century scale variations. Furthermore variations on these time scales appear to have been relatively small since the Younger Dryas (YD) ended, supporting our proposition concerning the importance of climate stability in the history of human culture. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Feynman, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM Joan.Feynman@jpl.nasa.gov NR 53 TC 5 Z9 5 U1 4 U2 14 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD OCT PY 2007 VL 84 IS 3-4 BP 295 EP 311 DI 10.1007/s10584-007-9248-1 PG 17 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 202NV UT WOS:000248911200004 ER PT J AU Kaihatu, JM Sheremet, A Holland, KT AF Kaihatu, James M. Sheremet, Alexandru Holland, K. Todd TI A model for the propagation of nonlinear surface waves over viscous muds SO COASTAL ENGINEERING LA English DT Article ID WATER-WAVES; INTERFACIAL WAVES; SOUTHWEST COAST; SHALLOW-WATER; GRAVITY-WAVES; SOFT BOTTOM; LONG WAVES; ATTENUATION; BED; TRANSFORMATION AB The effect of a thin viscous fluid-mud layer on nearshore nonlinear wave-wave interactions is studied using a parabolic frequency-domain nonlinear wave model, modified to incorporate a bottom dissipation mechanism based on a viscous boundary layer approach. The boundary-layer formulation allows for explicit calculation of the mud-induced wave damping rate. The model performed well in tests based on laboratory data. Numerical tests show that damping of high frequency waves occurs, mediated by "difference" nonlinear interactions. Simulations of 2-dimensional wave propagation over a mud "patch" of finite extent show that the wave dissipation causes significant downwave diffraction effects. (C) 2007 Elsevier B.V All rights reserved. C1 Texas A&M Univ, Zachry Dept Civil Engn, College Stn, TX 77843 USA. Univ Florida, Dept Civil Engn, Gainesville, FL 32611 USA. USN, Marine Geosci Div Code 7440 3, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. RP Kaihatu, JM (reprint author), Texas A&M Univ, Zachry Dept Civil Engn, College Stn, TX 77843 USA. EM jkaihatu@civil.tamu.edu RI Holland, K. Todd/A-7673-2011; Kaihatu, James/H-7561-2016 OI Holland, K. Todd/0000-0002-4601-6097; Kaihatu, James/0000-0002-9277-6409 NR 50 TC 27 Z9 27 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3839 J9 COAST ENG JI Coast. Eng. PD OCT PY 2007 VL 54 IS 10 BP 752 EP 764 DI 10.1016/j.coastaleng.2007.05.003 PG 13 WC Engineering, Civil; Engineering, Ocean SC Engineering GA 222WB UT WOS:000250327300003 ER PT J AU Camanho, PP Maimi, P Davila, CG AF Camanho, P. P. Maimi, P. Davila, C. G. TI Prediction of size effects in notched laminates using continuum damage mechanics SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE size effect; continuum damage mechanics; fracture mechanics ID COMPOSITE-MATERIALS; FRACTURE; FAILURE; CRACKING; STRENGTH; SIMULATION; CRITERIA; TENSILE; JOINTS AB This paper examines the use of a continuum damage model to predict strength and size effects in notched carbon-epoxy laminates. The effects of size and the development of a fracture process zone before final failure are identified in an experimental program. The continuum damage model is described and the resulting predictions of size effects are compared with alternative approaches: the point stress and the inherent flaw models, the Linear Elastic Fracture Mechanics approach, and the strength of materials approach. The results indicate that the continuum damage model is the most accurate technique to predict size effects in composites. Furthermore, the continuum damage model does not require any calibration and it is applicable to general geometries and boundary conditions. (c) 2007 Elsevier Ltd. All rights reserved. C1 Univ Porto, Fac Engn, DEMEGI, P-4200465 Oporto, Portugal. Univ Girona, AMADE, Girona, Spain. NASA, Langley Res Ctr, Hampton, VA USA. RP Camanho, PP (reprint author), Univ Porto, Fac Engn, DEMEGI, Rua Dr Roberto Frias, P-4200465 Oporto, Portugal. EM pcamanho@fe.up.pt RI Davila, Carlos/D-8559-2011; Camanho, Pedro /E-1666-2011; AMADE Research Group, AMADE/B-6537-2014; Balanzat, Josep Costa/C-1017-2014; Maimi, Pere/C-3581-2009; OI AMADE Research Group, AMADE/0000-0002-5778-3291; Maimi, Pere/0000-0002-7350-1506; Camanho, Pedro/0000-0003-0363-5207 NR 45 TC 138 Z9 144 U1 5 U2 34 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 OCT PY 2007 VL 67 IS 13 BP 2715 EP 2727 DI 10.1016/j.compscitech.2007.02.005 PG 13 WC Materials Science, Composites SC Materials Science GA 220NW UT WOS:000250164400008 ER PT J AU Erol, A Bebis, G Nicolescu, M Boyle, RD Twombly, X AF Erol, Ali Bebis, George Nicolescu, Mircea Boyle, Richard D. Twombly, Xander TI Vision-based hand pose estimation: A review SO COMPUTER VISION AND IMAGE UNDERSTANDING LA English DT Review DE hand pose estimation; gesture recognition; gesture-based HCI ID HUMAN-COMPUTER INTERACTION; HUMAN MOTION ANALYSIS; GESTURE RECOGNITION; MODEL; TRACKING; IMAGE; INTERFACE AB Direct use of the hand as an input device is an attractive method for providing natural human-computer interaction (HCI). Currently, the only technology that satisfies the advanced requirements of hand-based input for HCI is glove-based sensing. This technology, however, has several drawbacks including that it hinders the ease and naturalness with which the user can interact with the computer-controlled environment, and it requires long calibration and setup procedures. Computer vision (CV) has the potential to provide more natural, non-contact solutions. As a result, there have been considerable research efforts to use the hand as an input device for HCI. In particular, two types of research directions have emerged. One is based on gesture classification and aims to extract high-level abstract information corresponding to motion patterns or postures of the hand. The second is based on pose estimation systems and aims to capture the real 3D motion of the hand. This paper presents a literature review on the latter research direction, which is a very challenging problem in the context of HCI. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Nevada, Comp Vis Lab, Reno, NV 89557 USA. NASA, Ames Res Ctr, BioVis Lab, Moffett Field, CA 94035 USA. RP Erol, A (reprint author), Univ Nevada, Comp Vis Lab, Reno, NV 89557 USA. EM aerol@cse.unr.edu NR 135 TC 277 Z9 294 U1 3 U2 54 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1077-3142 EI 1090-235X J9 COMPUT VIS IMAGE UND JI Comput. Vis. Image Underst. PD OCT-NOV PY 2007 VL 108 IS 1-2 BP 52 EP 73 DI 10.1016/j.cviu.2006.10.012 PG 22 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 218RW UT WOS:000250033600006 ER PT J AU Russell, CT Capaccioni, F Coradini, A De Sanctis, MC Feldman, WC Jaumann, R Keller, HU McCord, TB McFadden, LA Mottola, S Pieters, CM Prettyman, TH Raymond, CA Sykes, MV Smith, DE Zuber, MT AF Russell, C. T. Capaccioni, F. Coradini, A. De Sanctis, M. C. Feldman, W. C. Jaumann, R. Keller, H. U. McCord, T. B. McFadden, L. A. Mottola, S. Pieters, C. M. Prettyman, T. H. Raymond, C. A. Sykes, M. V. Smith, D. E. Zuber, M. T. TI Dawn mission to vesta and ceres - Symbiosis between terrestrial observations and robotic exploration SO EARTH MOON AND PLANETS LA English DT Article DE Dawn Discovery mission; asteroids; Ceres; Vesta ID HF-W CHRONOMETRY; ASTEROID 1 CERES; INTERNAL STRUCTURE; CORE FORMATION; PARENT BODY; GAMMA-RAY; EUCRITE; METEORITES; 4-VESTA; ORIGIN AB The initial exploration of any planetary object requires a careful mission design guided by our knowledge of that object as gained by terrestrial observers. This process is very evident in the development of the Dawn mission to the minor planets 1 Ceres and 4 Vesta. This mission was designed to verify the basaltic nature of Vesta inferred both from its reflectance spectrum and from the composition of the howardite, eucrite and diogenite meteorites believed to have originated on Vesta. Hubble Space Telescope observations have determined Vesta's size and shape, which, together with masses inferred from gravitational perturbations, have provided estimates of its density. These investigations have enabled the Dawn team to choose the appropriate instrumentation and to design its orbital operations at Vesta. Until recently Ceres has remained more of an enigma. Adaptive-optics and HST observations now have provided data from which we can begin to confidently plan the mission. These observations reveal a rotationally symmetric body with little surface relief, an ultraviolet bright point that can be used as a control point for determining the pole and anchoring a geographic coordinate system. They also reveal albedo and color variations that provide tantalizing hints of surface processes. C1 Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, ESS, Los Angeles, CA 90095 USA. INAF, I-00133 Rome, Italy. IFSI, I-00133 Rome, Italy. IAFS, I-00133 Rome, Italy. LANL, Los Alamos, NM 87545 USA. DLR, D-12489 Berlin, Germany. MPAE, D-37191 Katlenburg Lindau, Germany. Univ Hawaii, Honolulu, HI 96822 USA. Univ Maryland, College Pk, MD 20742 USA. Brown Univ, Providence, RI 02912 USA. JPL, Pasadena, CA 91109 USA. PSI, Tucson, AZ 85719 USA. GSFC, Greenbelt, MD 20771 USA. MIT, Cambridge, MA 02139 USA. RP Russell, CT (reprint author), Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA. EM ctrussel@igpp.ucla.edu RI McFadden, Lucy-Ann/I-4902-2013; De Sanctis, Maria Cristina/G-5232-2013; OI McFadden, Lucy-Ann/0000-0002-0537-9975; De Sanctis, Maria Cristina/0000-0002-3463-4437; Capaccioni, Fabrizio/0000-0003-1631-4314 NR 55 TC 80 Z9 80 U1 0 U2 8 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PD OCT PY 2007 VL 101 IS 1-2 BP 65 EP 91 DI 10.1007/s11038-007-9151-9 PG 27 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 216ZK UT WOS:000249917500006 ER PT J AU Sulikowski, JA Driggers, WB Ingram, GW Kneebone, J Ferguson, DE Tsang, PCW AF Sulikowski, James A. Driggers, William B., III Ingram, G. Walter, Jr. Kneebone, Jeff Ferguson, Darren E. Tsang, Paul C. W. TI Profiling plasma steroid hormones: a non-lethal approach for the study of skate reproductive biology and its potential use in conservation management SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article; Proceedings Paper CT International Symposium on Biology of Skates held in Conjunction with the 22nd Annual Meeting of American-Elasmobranch-Society CY JUL 13-14, 2006 CL New Orleans, LA SP Amer Elasmobranch Soc DE skate; sexual maturity; reproduction; testosterone; estradiol; non-lethal technique ID DOGFISH SQUALUS-ACANTHIAS; WESTERN GULF; SEXUAL-MATURITY; SPHYRNA-TIBURO; SERUM CONCENTRATIONS; LEUCORAJA-OCELLATA; BONNETHEAD SHARKS; ATLANTIC STINGRAY; GONAD DEVELOPMENT; RAJA-ERINACEA AB Information regarding sexual maturity and reproductive cycles in skates has largely been based on gross morphological changes within the reproductive tract. While this information has proved valuable in obtaining life history information, it also necessitates sacrificing the skates to obtain this data. In contrast, few studies have used circulating steroid hormones to establish when these batoids become reproductively capable or for the determination of reproductive cyclicity. This study summarizes our current knowledge of hormonal analyses in determining skate reproductive status and offers information that suggests analysis of circulating steroid hormone concentrations provide a means to determine size at sexual maturity and asses reproductive cycles without the need to sacrifice the skate. C1 Univ New England, Ctr Marine Sci, Biddeford, ME 04005 USA. Mississippi Labs, SE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Pascagoula, MS 39568 USA. Univ New Hampshire, Dept Anim & Nutr Sci, Durham, NH 03824 USA. RP Sulikowski, JA (reprint author), Univ New England, Ctr Marine Sci, Biddeford, ME 04005 USA. EM jsulikowski@une.edu NR 29 TC 14 Z9 15 U1 2 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD OCT PY 2007 VL 80 IS 2-3 BP 285 EP 292 DI 10.1007/s10641-007-9257-y PG 8 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 216ZL UT WOS:000249917600013 ER PT J AU Bohn, TJ Lettenmaier, DP Sathulur, K Bowling, LC Podest, E McDonald, KC Friborg, T AF Bohn, T. J. Lettenmaier, D. P. Sathulur, K. Bowling, L. C. Podest, E. McDonald, K. C. Friborg, T. TI Methane emissions from western Siberian wetlands: heterogeneity and sensitivity to climate change SO ENVIRONMENTAL RESEARCH LETTERS LA English DT Article DE bog; methane; peatland; wetland; VIC; hydrology; model; TOPMODEL; topographic wetness index; BETHY; spatial distribution; climate; Siberia; Bakchar; Vasyugan; sensitivity; heterogeneity ID CO2; PEATLANDS; CH4; FLUXES; VARIABILITY; EXCHANGES; MODEL; SOIL AB The prediction of methane emissions from high-latitude wetlands is important given concerns about their sensitivity to a warming climate. As a basis for the prediction of wetland methane emissions at regional scales, we coupled the variable infiltration capacity macroscale hydrological model (VIC) with the biosphere-energy-transfer-hydrology terrestrial ecosystem model (BETHY) and a wetland methane emissions model to make large-scale estimates of methane emissions as a function of soil temperature, water table depth, and net primary productivity (NPP), with a parameterization of the sub-grid heterogeneity of the water table depth based on TOPMODEL. We simulated the methane emissions from a 100 km x 100 km region of western Siberia surrounding the Bakchar Bog, for a retrospective baseline period of 1980-1999 and have evaluated their sensitivity to increases in temperature of 0-5 degrees C and increases in precipitation of 0-15%. The interactions of temperature and precipitation, through their effects on the water table depth, played an important role in determining methane emissions from these wetlands. The balance between these effects varied spatially, and their net effect depended in part on sub-grid topographic heterogeneity. Higher temperatures alone increased methane production in saturated areas, but caused those saturated areas to shrink in extent, resulting in a net reduction in methane emissions. Higher precipitation alone raised water tables and expanded the saturated area, resulting in a net increase in methane emissions. Combining a temperature increase of 3 degrees C and an increase of 10% in precipitation to represent climate conditions that may pertain in western Siberia at the end of this century resulted in roughly a doubling in annual emissions. C1 [Bohn, T. J.; Lettenmaier, D. P.] Univ Washington, Dept Civil & Environm Engn, Seattle, WA 98195 USA. [Sathulur, K.; Bowling, L. C.] Purdue Univ, Dept Agron, W Lafayette, IN 47907 USA. [Podest, E.; McDonald, K. C.] NASA, Jet Prop Lab, Div Earth Sci, Water & Carbon Cycles Grp, Pasadena, CA USA. [Friborg, T.] Univ Copenhagen, Dept Geog & Geol, Copenhagen, Denmark. RP Bohn, TJ (reprint author), Univ Washington, Dept Civil & Environm Engn, Seattle, WA 98195 USA. RI Bowling, Laura/B-6963-2013; lettenmaier, dennis/F-8780-2011; Friborg, Thomas/E-5433-2015; Bohn, Theodore/K-4494-2012 OI Bowling, Laura/0000-0002-1439-3154; lettenmaier, dennis/0000-0003-3317-1327; Friborg, Thomas/0000-0001-5633-6097; Bohn, Theodore/0000-0002-1880-9129 NR 40 TC 55 Z9 58 U1 7 U2 46 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1748-9326 J9 ENVIRON RES LETT JI Environ. Res. Lett. PD OCT-DEC PY 2007 VL 2 IS 4 AR 045015 DI 10.1088/1748-9326/2/4/045015 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 269ML UT WOS:000253653000020 ER PT J AU Leptoukh, G Csiszar, I Romanov, P Shen, S Loboda, T Gerasimov, I AF Leptoukh, Gregory Csiszar, Ivan Romanov, Peter Shen, Suhung Loboda, Tatiana Gerasimov, Irina TI NASA NEESPI Data and Services Center for Satellite Remote Sensing Information SO ENVIRONMENTAL RESEARCH LETTERS LA English DT Editorial Material C1 [Leptoukh, Gregory; Shen, Suhung; Gerasimov, Irina] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Csiszar, Ivan; Romanov, Peter; Loboda, Tatiana] Univ Maryland, College Pk, MD 20742 USA. [Shen, Suhung] George Mason Univ, Fairfax, VA 22030 USA. [Gerasimov, Irina] RSIS, Greenbelt, MD USA. RP Leptoukh, G (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Romanov, Peter/F-5622-2010; Csiszar, Ivan/D-2396-2010 OI Romanov, Peter/0000-0002-2153-8307; NR 4 TC 9 Z9 9 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1748-9326 J9 ENVIRON RES LETT JI Environ. Res. Lett. PD OCT-DEC PY 2007 VL 2 IS 4 AR 045009 DI 10.1088/1748-9326/2/4/045009 PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 269ML UT WOS:000253653000014 ER PT J AU Moissl, C Osman, S La Duc, MT Dekas, A Brodie, E DeSantis, T Venkateswaran, K AF Moissl, Christine Osman, Shariff La Duc, Myron T. Dekas, Anne Brodie, Eoin DeSantis, Tadd Venkateswaran, Kasthuri TI Molecular bacterial community analysis of clean rooms where spacecraft are assembled (vol 61, pg 509, 2007) SO FEMS MICROBIOLOGY ECOLOGY LA English DT Correction C1 CALTECH, Jet Propuls Lab, Biotechnol & Planetary Protect Grp, Pasadena, CA 91125 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Environm Biotechnol, Berkeley, CA 94720 USA. RP Moissl, C (reprint author), CALTECH, Jet Propuls Lab, Biotechnol & Planetary Protect Grp, Pasadena, CA 91125 USA. RI Moissl-Eichinger, Christine/A-6682-2015; Brodie, Eoin/A-7853-2008 OI Moissl-Eichinger, Christine/0000-0001-6755-6263; Brodie, Eoin/0000-0002-8453-8435 NR 2 TC 1 Z9 1 U1 1 U2 4 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0168-6496 J9 FEMS MICROBIOL ECOL JI FEMS Microbiol. Ecol. PD OCT PY 2007 VL 62 IS 1 BP 131 EP 131 DI 10.1111/j.1574-6941.2007.00385.x PG 1 WC Microbiology SC Microbiology GA 215QR UT WOS:000249824600013 ER PT J AU Able, KW Clarke, PJ Charnbers, RC Witting, DA AF Able, Kenneth W. Clarke, Peter J. Charnbers, R. Christopher Witting, David A. TI Transitions in the morphological features, habitat use, and diet of young-of-the-year goosefish (Lophius americanus) SO FISHERY BULLETIN LA English DT Article ID SCOTIAN SHELF; PISCATORIUS; ANGLERFISH; FISHES; LOPHIIFORMES; ATLANTIC; LIFE; FOOD; AGE AB This study was designed to improve our understanding of transitions in the early life history and the distribution, habitat use, and diets for young-of-the -year (YOY) goosefish (Lophius americanus) and, as a result, their role in northeastern U.S. continental shelf ecosystems. Pelagic juveniles (>12 to ca. 50 mm total length [TL]) were distributed over most portions of the continental shelf in the Middle Atlantic Bight, Georges Bank, and into the Gulf of Maine. Most individuals settled by 50-85 mm TL and reached approximately 60-120 mm TL by one year of age. Pelagic YOY fed on chaetognaths, hyperiid amphipods, calanoid copepods, and ostracods, and benthic YOY had a varied diet of fishes and benthic crustaceans. Goosefish are widely scattered on the continental shelf in the Middle Atlantic Bight during their early life history and once settled, are habitat generalists, and thus play a role in many continental shelf habitats. C1 [Able, Kenneth W.; Clarke, Peter J.] Rutgers State Univ, Inst Marine & Coastal Sci, Marine Field Stn, Tuckerton, NJ 08087 USA. [Charnbers, R. Christopher] NOAA, Natl Marine Fisheries Serv, NEFSC, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. [Witting, David A.] NOAA, MSRP, Long Beach, CA 90802 USA. RP Able, KW (reprint author), Rutgers State Univ, Inst Marine & Coastal Sci, Marine Field Stn, 800 C-O 132 Great Bay Blvd, Tuckerton, NJ 08087 USA. EM able@marine.rutgers.edu NR 39 TC 1 Z9 1 U1 1 U2 7 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2007 VL 105 IS 4 BP 457 EP 469 PG 13 WC Fisheries SC Fisheries GA 241PA UT WOS:000251667100002 ER PT J AU Miller, TW Brodeur, RD AF Miller, Todd W. Brodeur, Richard D. TI Diets of and trophic relationships among dominant marine nekton within the northern California Current ecosystem SO FISHERY BULLETIN LA English DT Article ID BRITISH-COLUMBIA; OCEANOGRAPHIC CONDITIONS; VANCOUVER-ISLAND; PACIFIC-OCEAN; EL-NINO; OREGON; VARIABILITY; CHLOROPHYLL; COMMUNITY; SALMON AB In this study we analyzed the diets of 26 nekton species collected from two years (2000 and 2002) off Oregon and northern California to describe dominant nekton trophic groups of the northern California Current (NCC) pelagic ecosystem. We also examined interannual variation in the diets of three nekton species. Cluster analysis of predator diets resulted in nekton trophic groups based on the consumption of copepods, euphausiids, brachyuran larvae, larval-juvenile fishes, and adult nekton. However, many fish within trophic groups consumed prey from multiple trophic levels - euphausiids being the most widely consumed. Comparison of diets between years showed that most variation occurred with changes in the contribution of euphausiids and brachyuran larvae to nekton diets. The importance of euphausiids and other crustacean prey to nekton indicates that omnivory is an important characteristic of the NCC food web; however it may change during periods of lower or higher upwelling and ecosystem production. C1 [Miller, Todd W.] Oregon State Univ, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA. [Brodeur, Richard D.] NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. RP Miller, TW (reprint author), Oregon State Univ, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA. EM millertw@dpc.ehime-u.ac.ip NR 39 TC 29 Z9 29 U1 1 U2 10 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2007 VL 105 IS 4 BP 548 EP 559 PG 12 WC Fisheries SC Fisheries GA 241PA UT WOS:000251667100009 ER PT J AU Michener, WK Breshears, DD Hunsaker, CT Wickland, DE AF Michener, William K. Breshears, David D. Hunsaker, Carolyn T. Wickland, Diane E. TI Professional certification: increasing ecologists' effectiveness SO FRONTIERS IN ECOLOGY AND THE ENVIRONMENT LA English DT Editorial Material C1 Univ New Mexico, Albuquerque, NM 87131 USA. Univ Arizona, Tucson, AZ USA. USDA, Forest Serv, Fresno, CA USA. NASA, Washington, DC 20546 USA. RP Michener, WK (reprint author), Univ New Mexico, Albuquerque, NM 87131 USA. RI Breshears, David/B-9318-2009 OI Breshears, David/0000-0001-6601-0058 NR 0 TC 3 Z9 3 U1 0 U2 1 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 1540-9295 J9 FRONT ECOL ENVIRON JI Front. Ecol. Environ. PD OCT PY 2007 VL 5 IS 8 BP 399 EP 399 DI 10.1890/1540-9295(2007)5[399:PCIEE]2.0.CO;2 PG 1 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 217QJ UT WOS:000249962100001 ER PT J AU Michalski, JR Dobrea, EZN AF Michalski, Joseph R. Dobrea, Eldar Z. Noe TI Evidence for a sedimentary origin of clay minerals in the Mawrth Vallis region, Mars SO GEOLOGY LA English DT Article DE Mars; clay minerals; alteration; weathering; sediments; astrobiology AB Clay minerals detected spectroscopically in the Mawrth Vallis region of Mars correspond to a complex, layered, thick (>600 m) stratigraphic section of ancient bedrock. Because the light-toned, clay-bearing rocks are lithologically diverse over a broad area (>80,000 km(2)), have significant internal layering and complexity, and contain buried impact craters within the section (demonstrating that they were deposited over a geologically significant duration of time), we interpret the host rocks as sedimentary or possibly pyroclastic. Crater counts date the clay-bearing rocks to early-middle Noachian time (estimated as 3.8-4.1 Ga). Geomorphic observations suggest that the rocks were lithified early and deeply eroded during the late Noachian-early Hesperian. The combination of a probable ancient sedimentary context of the clays and a moderate pH formation environment implied by the occurrence of smectites clearly places these rocks among the most important targets for future astrobiological exploration. C1 Jet Propuls Lab, Pasadena, CA 91109 USA. Malin Space Sci Syst, San Diego, CA 92121 USA. RP Michalski, JR (reprint author), Jet Propuls Lab, MS 183-501,Oak Grove, Pasadena, CA 91109 USA. NR 11 TC 53 Z9 54 U1 1 U2 7 PU GEOLOGICAL SOC AMER, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD OCT PY 2007 VL 35 IS 10 BP 951 EP 954 DI 10.1130/G23854A.1 PG 4 WC Geology SC Geology GA 219RR UT WOS:000250102800022 ER PT J AU Kim, HR von Frese, RRB Taylor, PT Golynsky, AV Gaya-Pique, LR Ferraccioli, F AF Kim, Hyung Rae von Frese, Ralph R. B. Taylor, Patrick T. Golynsky, Alexander V. Gaya-Pique, Luis R. Ferraccioli, Fausto TI Improved magnetic anomalies of the Antarctic lithosphere from satellite and near-surface data SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE ADMAP; Antarctic magnetic anomalies; near-surface surveys; satellite surveys ID GEOMAGNETIC-FIELD; GRAVITY; CRUST; GEOLOGY; MODEL AB The Antarctic magnetic anomaly map compiled marine and airborne surveys collected south of 60 degrees S through 1999 and used Magsat data to help fill in the regional gaps between the surveys. Orsted and CHAMP satellite magnetic observations with greatly improved measurement accuracies and temporal and spatial coverage of the Antarctic, have now supplanted the Magsat data. We combined the new satellite observations with the near-surface survey data for an improved magnetic anomaly map of the Antarctic lithosphere. Specifically, we separated the crustal from the core and external field components in the satellite data using crustal thickness variations estimated from the terrain and the satellite-derived free-air gravity observations. Regional gaps in the near-surface surveys were then filled with predictions from crustal magnetization models that jointly satisfied the near-surface and satellite crustal anomalies. Comparisons in some of the regional gaps that also considered newly acquired aeromagnetic data demonstrated the enhanced anomaly estimation capabilities of the predictions over those from conventional minimum curvature and spherical harmonic geomagnetic field models. We also noted that the growing number of regional and world magnetic survey compilations involve coverage gaps where these procedures can contribute effective near-surface crustal anomaly estimates. C1 UMBC, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. NASA, GSFC, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. Ohio State Univ, Sch Earth Sci, Columbus, OH 43210 USA. VNIIOkeangeol, RU-190121 St Petersburg, Russia. CNRS, IPGP, F-75005 Paris, France. British Antarctic Survey, Cambridge CB3 0ET, England. RP Kim, HR (reprint author), UMBC, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. EM kimhr@core2.gsfc.nasa.gov RI Taylor, Patrick/D-4707-2012 OI Taylor, Patrick/0000-0002-1212-9384 NR 34 TC 6 Z9 6 U1 0 U2 5 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD OCT PY 2007 VL 171 IS 1 BP 119 EP 126 DI 10.1111/j.1365-246X.2007.03516.x PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 219IW UT WOS:000250079100009 ER PT J AU Yang, P Cao, Y Evans, J AF Yang, Phil Cao, Ying Evans, John TI Web map server performance and client design principles SO GISCIENCE & REMOTE SENSING LA English DT Article AB The OGC Web Map Service facilitates sharing geospatial information via the World Wide Web. However, this approach presents performance challenges because some Web mapping servers are not well optimized for real-world demands, and some client applications are not well designed for performance. To address this problem, we: (1) test the performance of different WMS servers; (2) analyze the test to find performance patterns; (3) utilize the patterns to articulate client design principles; and (4) develop a prototype to test the principles. C1 George Mason Univ, Coll Sci, Joint Ctr Intelligent Spatial Comp, Fairfax, VA 22030 USA. NASA, Goddard Space Flight Ctr, Geosci Interoperabil Off, Greenbelt, MD 20771 USA. Global Sci & Technol Inc, Greenbelt, MD 20770 USA. RP Yang, P (reprint author), George Mason Univ, Coll Sci, Joint Ctr Intelligent Spatial Comp, 4400 Univ Dr, Fairfax, VA 22030 USA. EM cyang3@gmu.edu RI Yang, Chaowei/A-9881-2017; OI Yang, Chaowei/0000-0001-7768-4066 NR 16 TC 7 Z9 7 U1 1 U2 9 PU BELLWETHER PUBL LTD PI COLUMBIA PA 8640 GUILFORD RD, STE 200, COLUMBIA, MD 21046 USA SN 1548-1603 J9 GISCI REMOTE SENS JI GISci. Remote Sens. PD OCT-DEC PY 2007 VL 44 IS 4 BP 320 EP 333 DI 10.2747/1548-1603.44.4.320 PG 14 WC Geography, Physical; Remote Sensing SC Physical Geography; Remote Sensing GA 221WW UT WOS:000250259100002 ER PT J AU Tullis, JA Cothren, JD Irwin, DE Yeager, CP Limp, WF Wilson, JM Gorham, BE Ogle, S AF Tullis, Jason A. Cothren, Jackson D. Irwin, Daniel E. Yeager, Carey P. Limp, W. Fredrick Wilson, John M. Gorham, Bruce E. Ogle, Stephen TI Yearly extraction of central America's land cover for carbon flux monitoring SO GISCIENCE & REMOTE SENSING LA English DT Article ID MODIS; CLASSIFICATION; VEGETATION; FORESTS; NORTH; SOILS AB Ideal remote sensor land cover extraction for national to regional carbon flux monitoring constitutes highly accurate change detection on an annual basis, a challenge magnified in the cloud-occluded tropics. Focusing on seven Central American countries from Belize to Panama, this study tested the feasibility of yearly land cover extraction from MODIS surface reflectance composites, ancillary land cover maps, and country-produced reference polygons. GIS models were created to automate the country-specific process of generating annual input tables for a greenhouse gas inventory tool. MODIS-favorable results in a six-category schema suggest that improvements may depend on international reference data warehousing and interoperability. C1 Univ Arkansas, Ctr Adv Spatial Technologies, Fayetteville, AR 72701 USA. NASA, George C Marshall Space Flight Ctr, Erath & Planetary Sci Branch, Huntsville, AL 35805 USA. Univ Florida, Dept Zool, Gainesville, FL 32611 USA. Univ Arkansas, Inc Ctr Acad Excellence, Ctr Adv Spatial Technologies, JB Hunt Transport Serv 304, Fayetteville, AR 72701 USA. Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA. RP Tullis, JA (reprint author), Univ Arkansas, Ctr Adv Spatial Technologies, 113 Ozark Hall, Fayetteville, AR 72701 USA. EM jatulIis@cast.uark.edu OI Ogle, Stephen/0000-0003-1899-7446 NR 25 TC 2 Z9 2 U1 0 U2 3 PU BELLWETHER PUBL LTD PI COLUMBIA PA 8640 GUILFORD RD, STE 200, COLUMBIA, MD 21046 USA SN 1548-1603 J9 GISCI REMOTE SENS JI GISci. Remote Sens. PD OCT-DEC PY 2007 VL 44 IS 4 BP 334 EP 355 DI 10.2747/1548-1603.44.4.334 PG 22 WC Geography, Physical; Remote Sensing SC Physical Geography; Remote Sensing GA 221WW UT WOS:000250259100003 ER PT J AU Thomas, RH AF Thomas, Robert H. TI Tide-induced perturbations of glacier velocities SO GLOBAL AND PLANETARY CHANGE LA English DT Article DE glacier; ice shelf; force model; tide; ice velocities ID ICE STREAM; ALASKA; SPEED AB Recent observations showing substantial diurnal changes in velocities of glaciers flowing into the ocean, measured at locations far inland of glacier grounding lines, add fuel to the ongoing debate concerning the ability of glaciers to transmit longitudinal-stress perturbations over large distances. Resolution of this debate has major implications for the prediction of glacier mass balance, because it determines how rapidly a glacier can respond dynamically to changes such as weakening or removal of an ice shelf Current IPCC assessment of sea-level rise takes little account of such changes, on the assumption that dynamic responses would be too slow to have any appreciable effect on ice discharge fluxes. However, this assumption must be questioned in view of observations showing massive increases in glacier velocities following removal of parts of the Larsen Ice Shelf, Antarctica, and of others showing diurnal velocity changes apparently linked to the tides. Here, I use a simple force-perturbation model to calculate the response of glacier strain rates to tidal rise and fall, assuming associated longitudinal-force perturbations are transmitted swiftly far inland of the glacier grounding line. Results show reasonable agreement with observations from an Alaskan glacier, where the velocity changes extended only a short distance up-glacier. However, for larger Antarctic glaciers, big velocity changes extending far upstream cannot be explained by this mechanism, unless ice-shelf "back forces" change substantially with the tides. Additional insight will require continuous measurement of velocity and strain-rate profiles along flow lines of glaciers and ice shelves. An example is suggested, involving continuous GPS measurements at a series of locations along the centre line of Glaciar San Rafael, Chile, extending from near the calving front to perhaps 20 km inland. Tidal range here is about +/- 0.8 m, which should be sufficient to cause a variation in ice-front velocity of +/- 2 cm h(-1) about its average value of 75 cm h(-1), assuming local seawater depth of 150 m and glacier thickness of 200-400 m. (C) 2006 Elsevier B.V. All rights reserved. C1 NASA, Wallops Flight Facil, EG&G Serv, Wallops Isl, VA 23337 USA. Ctr Estudios Cient, Valdivia, Chile. RP Thomas, RH (reprint author), NASA, Wallops Flight Facil, EG&G Serv, Bldg N-159, Wallops Isl, VA 23337 USA. EM thomas@osb.wff.nasa.gov NR 13 TC 18 Z9 18 U1 0 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD OCT PY 2007 VL 59 IS 1-4 BP 217 EP 224 DI 10.1016/j.gloplacha.2006.11.017 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 232JR UT WOS:000251015900019 ER PT J AU Meador, MA Meador, MA Tyson, DS Ilhan, F AF Meador, Michael A. Meador, Mary Ann Tyson, Daniel S. Ilhan, Faysal TI Use of diels-alder cyclopolymerizations in the photocuring of polymers SO HIGH PERFORMANCE POLYMERS LA English DT Article; Proceedings Paper CT Polycondensation 2006 Workshop CY AUG 26-30, 2006 CL Koc Univ, Istanbul, TURKEY HO Koc Univ DE polyimide; polyester; bismaleimide; bisacrylate; photocuring AB Radiation curable polymers are needed for use in space rigidizable inflatable structures (antenna supports, habitats, rovers) for future NASA missions. One approach developed at NASA Glenn utilizes the Diels-Alder trapping of bisdienes (o-xylylenols) generated by the photolysis of o-methylphenyl ketones with bisdienophiles (bismaleimides and bisacrylates). A variety of polyimides and polyesters have been prepared with this chemistry and their properties evaluated. The glass transition temperatures of these resins varied from -27 to over 300 degrees C depending upon monomer structures. Onsets of decomposition, measured by thermogravimetric analysis in air, were in the neighborhood of 300 degrees C and did not vary much with monomer structure. Some monomer systems are liquids at room temperature and have the potential for use in solvent-free UV-cured coatings. C1 NASA, Glenn Res Ctr, Polymer Mat Branch, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Brookpark, OH 44142 USA. Abu Dhabi Univ, Abhu Dhabi, U Arab Emirates. RP Meador, MA (reprint author), NASA, Glenn Res Ctr, Polymer Mat Branch, Cleveland, OH 44135 USA. OI Meador, Mary Ann/0000-0003-2513-7372 NR 7 TC 0 Z9 0 U1 1 U2 8 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 OCT-DEC PY 2007 VL 19 IS 5-6 BP 665 EP 683 DI 10.1177/0954008307081210 PG 19 WC Polymer Science SC Polymer Science GA 223OC UT WOS:000250379400015 ER PT J AU Sunshine, JM Groussin, O Schultz, PH A'Hearn, MF Feaga, LM Farnham, TL Klaasen, KP AF Sunshine, Jessica M. Groussin, Olivier Schultz, Peter H. A'Hearn, Michael F. Feaga, Lori M. Farnham, Tony L. Klaasen, Kenneth P. TI The distribution of water ice in the interior of Comet Tempel 1 SO ICARUS LA English DT Article DE Comet Tempel-1; comets; composition; interiors; spectroscopy; infrared observations ID DEEP-IMPACT; OBLIQUE IMPACTS; COMET 81P/WILD-2; EXPECTATIONS; 9P/TEMPEL-1; PARTICLES; DUST; SIZE AB The Deep Impact flyby spacecraft includes a 1.05 to 4.8 mu m infrared (IR) spectrometer. Although ice was not observed on the surface in the impact region, strong absorptions near 3 pm due to water ice are detected in IR measurements of the ejecta from the impact event. Absorptions from water ice occur throughout the IR dataset be-inning three seconds after impact through the end of observations, similar to 45 min after impact. Spatially and temporally resolved IR spectra of the ejecta are analyzed in conjunction with laboratory impact experiments. The results imply an internal stratigraphy for Tempel 1 consisting of devolatilized materials transitioning to unaltered components at a depth of approximately one meter. At greater depths, which are thermally isolated from the surface, water ice is present. Up to depths of 10 to 20 in, the maximum depths excavated by the impact, these pristine materials consist of very fine grained (similar to 1 +/- 1 mu m) water ice particles, which are free from refractory impurities. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Observ Astron Marseille Provence, Astrophys Lab, F-13376 Marseille, France. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. RP Sunshine, JM (reprint author), Univ Maryland, Dept Astron, Comp & Space Sci Bldg, College Pk, MD 20742 USA. EM jess@astro.umd.edu NR 41 TC 44 Z9 44 U1 0 U2 6 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 OCT PY 2007 VL 190 IS 2 BP 284 EP 294 DI 10.1016/j.icarus.2007.04.024 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900002 ER PT J AU Harker, DE Woodward, CE Wooden, DH Fisher, RS Trujillo, CA AF Harker, David E. Woodward, Charles E. Wooden, Diane H. Fisher, R. Scott Trujillo, Chad A. TI Gemini-N mid-IR observations of the dust properties of the ejecta excavated from Comet 9P/Tempel 1 during Deep Impact SO ICARUS LA English DT Article DE Comet Tempel-1; infrared observations ID SPITZER-SPACE-TELESCOPE; COMET HALE-BOPP; INTERSTELLAR SILICATE MINERALOGY; INFRARED OBSERVATIONS; OPTICAL-PROPERTIES; ION IRRADIATION; MICRON SPECTRA; SOLAR-SYSTEM; KUIPER-BELT; C/1995 O1 AB We present mid-infrared spectra and images from the Gemini-N (+MICHELLE) observational campaign of Comet 9P/Tempel 1 before, during, and after its encounter with Deep Impact. We use our thermal grain model to probe the 10 pm properties of the dust grains in the coma of the comet. Before impact (3 July 2005 UT), and more than 24 h after impact (5, 16, and 28 July 2005 UT), the comet dust grains were composed mostly of amorphous olivine, and were relatively large (peak of the grain size distribution a(p) = 0.7-1.5 pm). For the night of impact, we extract spectra by centering on the nucleus, and offset 1 '' from the nucleus in the direction of the impact ejecta plume. We find small dust grains (similar to 0.2 pm) of a diverse mineralogy (amorphous olivine, amorphous pyroxene, amorphous carbon, and crystalline olivine) populating the ejecta. The submicron sized dust grains move faster than the other, larger grains ( greater than or similar to 0.7 mu m), with amorphous olivine and amorphous carbon traveling together, and amorphous pyroxene and crystalline olivine dispersing at a similar rate. Deriving a velocity law from a time-of-flight analysis, we find that the material traveled with a velocity law scaled by upsilon(0.2 mu m) = 220 +/- 20 ms(-1) and with a power of p = 0.5. This velocity power-law requires a sustained release of grains for the duration of 45-60 min after impact. Since the mineral species are traveling at different speeds, and there was a sustained release of grains due to a possible '' gas-plume,'' we conclude that the different minerals did not originate from grain aggregates destroyed by the impact, but instead arise from an inhomogeneous nucleus. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Univ Minnesota, Sch Phys & Astron, Dept Astron, Minneapolis, MN 55455 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Gemini Observ, Hilo, HI 96720 USA. RP Harker, DE (reprint author), Univ Calif San Diego, Ctr Astrophys & Space Sci, 9500 Gilman Dr, La Jolla, CA 92093 USA. EM dharker@ucsd.edu OI Harker, David/0000-0001-6397-9082 NR 80 TC 31 Z9 31 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 OCT PY 2007 VL 190 IS 2 BP 432 EP 453 DI 10.1016/j.icarus.2007.03.008 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900010 ER PT J AU Fischer, G Kurth, WS Dyudina, UA Kalser, ML Zarka, P Lecacheux, A Ingersoll, AP Gurnett, DA AF Fischer, G. Kurth, W. S. Dyudina, U. A. Kalser, M. L. Zarka, P. Lecacheux, A. Ingersoll, A. P. Gurnett, D. A. TI Analysis of a giant lightning storm on Saturn SO ICARUS LA English DT Article DE Saturn; lightning; Saturn; atmosphere; radio observations ID RADIO ASTRONOMY OBSERVATIONS; ELECTROSTATIC DISCHARGES; IONOSPHERE; MODEL; ATMOSPHERE; SPOKES; WATER; RINGS AB On January 23, 2006, the Cassini/RPWS (Radio and Plasma Wave Science) instrument detected a massive outbreak of SEDs (Saturn Electrostatic Discharges). The following SED storm lasted for about one month and consisted of 71 consecutive episodes. It exceeded all other previous SED observations by Cassini as well as by the Voyagers with regard to number and rate of detected events. At the same time astronomers at the Earth as well as Cassini/ISS (Imaging Science Subsystem) detected a distinctive bright atmospheric cloud feature at a latitude of 35 degrees South, strongly confirming the current interpretation of SEDs being the radio signatures of lightning flashes in Saturn's atmosphere. In this paper we will analyze the main physical properties of this SED storm and of a single small SED storm from 2005. The giant SED storm of 2006 had maximum burst rates of I SED every 2 s, its episodes lasted for 5.5 It on average, and the episode's periodicity of about 10.66 It exactly matched the period of the ISS observed cloud feature. Using the low frequency cutoff of SED episodes we determined an ionospheric electron density around 104 cm(-3) for the dawn side of Saturn. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. CALTECH, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Observ Paris, F-92195 Meudon, France. RP Fischer, G (reprint author), Univ Iowa, Dept Phys & Astron, 203 Van Allen Hall, Iowa City, IA 52242 USA. EM georg-fischer@uiowa.edu OI Kurth, William/0000-0002-5471-6202 NR 35 TC 34 Z9 34 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 OCT PY 2007 VL 190 IS 2 BP 528 EP 544 DI 10.1016/j.icarus.2007.04.002 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900017 ER PT J AU Dyudina, UA Ingersoll, AP Ewald, SP Porco, CC Fischer, G Kurth, W Desch, M Del Genio, A Barbara, J Ferrier, J AF Dyudina, Ulyana A. Ingersoll, Andrew P. Ewald, Shawn P. Porco, Carolyn C. Fischer, Georg Kurth, William Desch, Michael Del Genio, Anthony Barbara, John Ferrier, Joseph TI Lightning storms on Saturn observed by Cassini ISS and RPWS during 2004-2006 SO ICARUS LA English DT Article DE lightning; Saturn; atmosphere; atmospheres; dynamics; meteorology; spectroscopy ID IMAGING SCIENCE; ELECTROSTATIC DISCHARGES; ATMOSPHERE; CONVECTION; JUPITER; PLANETS; IMAGES AB We report on Cassini Imaging Science Subsystem (ISS) data correlated with Radio and Plasma Wave Science (RPWS) observations, which indicate lightning on Saturn. A rare bright cloud erupt at similar to 35 degrees South planetocentric latitude when radio emissions (Saturn Electrostatic Discharges, or SEDs) Occur. The cloud consisting of few consecutive eruptions typically lasts for several weeks, and then both the cloud and the SEDs disappear. They may reappear again after several months or may stay inactive for a year. Possibly, all the clouds are produced by the same atmospheric disturbance which drifts West at 0.45 degrees/day. As of March 2007, four such correlated visible and radio storms have been observed since Cassini Saturn Orbit Insertion (July 2004). In all four cases the SEDs are periodic with roughly Saturn's rotation rate (10(h)39(m)), and show correlated phase relative to the times when the clouds are seen on the spacecraft-facing side of the planet, as had been shown for the 2004 storms in [Porco, C.C., and 34 colleagues, 2005. Science 307, 1243-12471. The 2000-km-scate storm clouds erupt to unusually high altitudes and then slowly fade at high altitudes and spread at low altitudes. The onset time of individual eruptions is less than a day during which time the SEDs reach their maximum rates. This suggests vigorous atmospheric updrafts accompanied by strong precipitation and lightning. Unlike lightning on Earth and Jupiter, where considerable lightning activity is known to exist, only one latitude on Saturn has produced lightning strong enough to be detected during the two and a half years of Cassini observations. This may partly be a detection issue. (C) 2007 Elsevier Inc. All rights reserved. C1 CALTECH, Pasadena, CA 91125 USA. CICLOPS, Space Sci Inst, Boulder, CO 80301 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Dyudina, UA (reprint author), CALTECH, Pasadena, CA 91125 USA. EM ulyana@gps.caltech.edu RI Del Genio, Anthony/D-4663-2012; OI Del Genio, Anthony/0000-0001-7450-1359; Kurth, William/0000-0002-5471-6202 NR 22 TC 39 Z9 39 U1 1 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 EI 1090-2643 J9 ICARUS JI Icarus PD OCT PY 2007 VL 190 IS 2 BP 545 EP 555 DI 10.1016/j.icarus.2007.03.035 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900018 ER PT J AU Howett, CJA Irwin, PGJ Teanby, NA Simon-Miller, A Calcutt, SB Fletcher, LN de Kok, R AF Howett, C. J. A. Irwin, P. G. J. Teanby, N. A. Simon-Miller, A. Calcutt, S. B. Fletcher, L. N. de Kok, R. TI Meridional variations in stratospheric acetylene and ethane in the southern hemisphere of the saturnian atmosphere as determined from Cassini/CIRS measurements SO ICARUS LA English DT Article DE infrared observations; Saturn; atmosphere ID ISO-SWS OBSERVATIONS; INFRARED OBSERVATIONS; THERMAL-RADIATION; UPPER TROPOSPHERE; LINE PARAMETERS; VOYAGER; TEMPERATURE; SYSTEM; SPECTROMETER; HITRAN AB These are the first results from nadir studies of meridional variations in the abundance of stratospheric acetylene and ethane from Cassini/CIRS data in the southern hemisphere of Saturn. High resolution, 0.5 cm(-1), CIRS data was used from three data sets taken in June-November 2004 and binned into 2 degrees wide latitudinal strips to increase the signal-to-noise ratio. Tropospheric and stratospheric temperatures were initially retrieved to determine the temperature profile for each latitude bin. The stratospheric temperature at 2 mbar increased by 14 K from 9 degrees to 68 degrees S, including a steep 4 K rise between 60 degrees and 68 degrees S. The tropospheric temperatures showed significantly more meridional variation than the stratospheric ones, the locations of which are strongly correlated to that of the zonal jets. Stratospheric acetylene abundance decreases steadily from 30 to 68 degrees S, by a factor of 1.8 at 2.0 mbar. Between 18 degrees and 30 degrees S the acetylene abundance increases at 2.0 mbar. Global values for acetylene have been calculated as (1.9 +/- 0.19) x 10(-7) at 2.0 mbar, (2.6 +/- 0.27) x 10(-7) at 1.6 mbar and (3.1 +/- 0.32) x 10(-7) at 1.4 mbar. Global values for ethane are also determined and found to be (1.6 +/- 0.25) x 10(-5) at 0.5 mbar and (1.4 +/- 0.19) x 10(-5) at 1.0 mbar. Ethane abundance in the stratosphere increases towards the south pole by a factor of 2.5 at 2.0 mbar. The increase in stratospheric ethane is especially pronounced polewards of 60 degrees S at 2.0 mbar. The increase of stratospheric ethane towards the south pole supports the presence of a meridional wind system in the stratosphere of Saturn. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Howett, CJA (reprint author), Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. EM howett@atm.ox.ac.uk RI Fletcher, Leigh/D-6093-2011; Simon, Amy/C-8020-2012; OI Fletcher, Leigh/0000-0001-5834-9588; Simon, Amy/0000-0003-4641-6186; Calcutt, Simon/0000-0002-0102-3170; Teanby, Nicholas/0000-0003-3108-5775; Irwin, Patrick/0000-0002-6772-384X NR 57 TC 22 Z9 22 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 EI 1090-2643 J9 ICARUS JI Icarus PD OCT PY 2007 VL 190 IS 2 BP 556 EP 572 DI 10.1016/j.icarus.2007.03.009 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900019 ER PT J AU Thomas, PC Burns, JA Helfenstein, R Squyres, S Veverka, J Porco, C Turtle, EP McEwen, A Denk, T Giese, B Roatsch, T Johnson, TV Jacobson, RA AF Thomas, P. C. Burns, J. A. Helfenstein, R. Squyres, S. Veverka, J. Porco, C. Turtle, E. P. McEwen, A. Denk, T. Giese, B. Roatsch, T. Johnson, T. V. Jacobson, R. A. TI Shapes of the saturnian icy satellites and their significance SO ICARUS LA English DT Article DE Saturn; satellites satellites; shapes; interiors ID GRAVITY-FIELD; TRACKING DATA; ENCELADUS; ASTEROIDS; HISTORY; MODELS; SYSTEM; TOPOGRAPHY; PLUME; MASS AB The sizes and shapes of six icy saturnian satellites have been measured from Cassini Imaging Science Subsystem (ISS) data, employing limb coordinates and stereogrammetric control points. Mimas, Enceladus, Tethys, Dione and Rhea are well described by triaxial ellipsoids; Iapetus is best represented by an oblate spheroid. All satellites appear to have approached relaxed, equilibrium shapes at some point in their evolution, but all support at least 300 m of global -wavelength topography. The shape of Enceladus is most consistent with a homogeneous interior. If Enceladus is differentiated, its shape and apparent relaxation require either lateral inhomogeneities in an icy mantle and/or an irregularly shaped core. Iapetus supports a fossil bulge of over 30 km, and provides a benchmark for impact modification of shapes after global relaxation. Satellites such as Mimas that have smoother limbs than Iapetus, and are expected to have higher impact rates, must have relaxed after the shape of Iapetus was frozen. (C) 2007 Elsevier Inc. All rights reserved. C1 Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. Space Sci Inst, Boulder, CO 80301 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Free Univ Berlin, Inst Geol Wissensch, D-12249 Berlin, Germany. German Aerosp Ctr, Inst Planetary Res, D-12489 Berlin, Germany. CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Thomas, PC (reprint author), Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. EM pct2@cornell.edu RI Turtle, Elizabeth/K-8673-2012 OI Turtle, Elizabeth/0000-0003-1423-5751 NR 40 TC 86 Z9 86 U1 0 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 OCT PY 2007 VL 190 IS 2 BP 573 EP 584 DI 10.1016/j.icarus.2007.03.012 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900020 ER PT J AU Iess, L Rappaport, NJ Tortora, P Lunine, J Armstrong, JW Asmar, SW SomenZi, L Zingoni, F AF Iess, Luciano Rappaport, Nicole J. Tortora, Paolo Lunine, Jonathan Armstrong, John W. Asmar, Sami W. SomenZi, Lucia Zingoni, Francesco TI Gravity field and interior of Rhea from Cassini data analysis SO ICARUS LA English DT Article DE Saturn; satellites; radio observations ID ICY SATELLITES; INTERNAL STRUCTURE; SPACECRAFT AB The Cassini spacecraft encountered Rhea on November 26, 2005. Analysis of the Doppler data acquired at and around closest approach yields the mass of Rhea and the quadrupole moments of its gravity field with unprecedented accuracy. We obtained GM = 153.9395 +/- 0.0018 km(3) s(-2) which corresponds to a density of 1232.8 +/- 5.4 ka m(-3). Our results for J(2) and C-22 are (7.947 +/- 0.892) x 10(-4),and (2.3526 +/- 0.0476) x 10(-4) respectively. These values are consistent with hydrostatic equilibrium. From the value of C22, we infer the non-dimensional moment of inertia C/MR2 = 0.3721 +/- 0.0036. Our models of Rhea's interior based on the gravity data favor an almost undifferentiated satellite. A discontinuity between a core and a mantle is possible but not required by the data. Models with a constant silicate mass fraction throughout the body cannot account for the determined quadrupole coefficients. The data exclude fully differentiated models in which the core would be composed of unhydrated silicates and the mantle would be composed of pure ice. If the mantle contains 10% in mass of silicates, the core extends to 630 km in radius and has a silicate mass fraction of 40%. A continuous model in which the silicates are more concentrated toward the center of the body than in the outer layers is allowed by the gravity data but excluded by thermal evolution considerations. The one model that fits the gravity data and is self-consistent when energy transport and ice melting are qualitatively considered is an "almost undifferentiated" Rhea, in which a very large uniform core is surrounded by a relatively thin ice shell containing no rock at all. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Roma La Sapienza, Dipartimento Ingn Aerosspaziale & Astron, I-00184 Rome, Italy. CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. Univ Bologna, Fac Ingn, DIEM II, I-47100 Forli, Italy. INAF, IFSI, I-00133 Rome, Italy. RP Iess, L (reprint author), Univ Roma La Sapienza, Dipartimento Ingn Aerosspaziale & Astron, Via Eudossiana 18, I-00184 Rome, Italy. EM iess@hermes.diaa.uniromal.it RI IESS, Luciano/F-4902-2011; Tortora, Paolo/J-6191-2012 OI IESS, Luciano/0000-0002-6230-5825; Tortora, Paolo/0000-0001-9259-7673 NR 25 TC 26 Z9 26 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 OCT PY 2007 VL 190 IS 2 BP 585 EP 593 DI 10.1016/j.icarus.2007.03.027 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900021 ER PT J AU Busch, MW Giorgini, JD Ostro, SJ Benner, LAM Jurgens, RE Rose, R Hicks, MD Pravec, P Kusnirak, P Ireland, MJ Scheeres, DJ Broschart, SB Magri, C Nolan, MC Hine, AA Margot, JL AF Busch, Michael W. Giorgini, Jon D. Ostro, Steven J. Benner, Lance A. M. Jurgens, Raymond E. Rose, Randy Hicks, Michael D. Pravec, Petr Kusnirak, Peter Ireland, Michael J. Scheeres, Daniel J. Broschart, Stephen B. Magri, Christopher Nolan, Michael C. Hine, Alice A. Margot, Jean-Luc TI Physical modeling of near-Earth Asteroid (29075) 1950 DA SO ICARUS LA English DT Article DE asteroids; composition; asteroids; dynamics; asteroids; rotation; near-Earth objects; radar observations AB Near-Earth Asteroid (29075) 1950 DA may closely encounter Earth in 2880. The probability of Earth impact may be as high as 1/300, but the outcome of the encounter depends critically on the physical properties of the asteroid [Giorgini et al., 2002. Science 196, 132-136]. We have used Arecibo and Goldstone radar data and optical lighteurves to estimate the shape, spin state, and surface structure of 1950 DA. The data allow two distinct models. One rotates prograde and is roughly spheroidal with mean diameter 1. 16 +/- 0.12 km. The other rotates retrograde and is oblate and about 30% larger. Both models suggest a nickel-iron or enstatite chondritic composition. Ground-based observations should be able to determine which model is correct within the next several decades. (C) 2007 Elsevier Inc. All rights reserved. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. Acad Sci Czech Republic, Astron Inst, CZ-25165 Ondrejov, Czech Republic. Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. Univ Maine, Farmington, ME 04938 USA. Natl Astron & Ionosphere Ctr, Arecibo Observ, Arecibo, PR 00612 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. RP Busch, MW (reprint author), CALTECH, Div Geol & Planetary Sci, Mail Code 150-21, Pasadena, CA 91125 USA. EM busch@caltech.edu RI Margot, Jean-Luc/A-6154-2012; Nolan, Michael/H-4980-2012; Pravec, Petr/G-9037-2014 OI Margot, Jean-Luc/0000-0001-9798-1797; Nolan, Michael/0000-0001-8316-0680; NR 24 TC 18 Z9 19 U1 0 U2 1 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 OCT PY 2007 VL 190 IS 2 BP 608 EP 621 DI 10.1016/j.icarus.2007.03,032 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900023 ER PT J AU Hillier, JK Green, SF McBride, N Altobelli, N Postberg, F Kempf, S Schwanethal, J Srama, R McDonnell, JA Gruen, E AF Hillier, Jon K. Green, Simon F. McBride, Neil Altobelli, Nicolas Postberg, Frank Kempf, Sascha Schwanethal, James Srama, Ralf McDonnell, J. Anthony M. Gruen, Eberhard TI \ interplanetary dust detected by the cassini CDA chemical analyser SO ICARUS LA English DT Article DE interplanetary dust; comets; dust; meteorites; mineralogy; asteroids ID COMET 81P/WILD-2; SOLAR-SYSTEM; MIDINFRARED SPECTRUM; INTERSTELLAR DUST; ZODIACAL LIGHT; IRAS OBSERVATIONS; ASTEROID BELT; EARTHS ORBIT; COSMIC DUST; PARTICLES AB During its cruise phase, prior to encountering Jupiter, the Cosmic Dust Analyser (CDA) onboard the Cassini spacecraft returned time of flight mass spectra (TOF MS) of two interplanetary dust particles. Both particles were found to be iron-rich, with possible traces of hydrogen, carbon, nickel, chromium, manganese, titanium, vanadium and minor silicates. Carbon, hydrogen, oxygen and potassium are also present as possible contaminants of the impact target of CDA. Silicates and magnesium do not feature predominantly in the spectra; this is surprising considering the expected dominance of silicate-rich minerals in interplanetary dust particles. The particle masses are 9(-8)(+55) x 10(-14) kg and 1.4(-0.8)(+1.9) x 10(-12) kg The corresponding radii ranges for the particles, assurning densities from 7874-2500 kg m(-3) are 0.7-4 pm and 2.6-6.8 mu m, respectively. With the same density assumptions the beta values (ratio of radiation pressure to gravitational force) are estimated as 0.027-0.21 and 0.0 16-0.06 respectively, allowing possible orbits to be calculated. The resulting orbits are bound and prograde with semi-major axes, eccentricities and inclinations in the region of 0.3-1.26 AU, 0.4-1.0 and 0-60 degrees for the first particle and 0.8-2.5 AU, 0.2-0.9 and 0-30 degrees for the second. The more probable orbits within these ranges indicate that the first particle is in an Aten-like orbit, whilst the second particle is in an Apollo-like orbit, despite both grains having very similar, predominantly metallic compositions. Other possible orbital solutions for both particles encompass orbits which more closely resemble those of Jupiter-family comets. (C) 2007 Elsevier Inc. All rights reserved. C1 Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. NASA, JPL, Pasadena, CA 91101 USA. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. Open Univ, Dept Earth Sci, Milton Keynes MK7 6AA, Bucks, England. Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. RP Hillier, JK (reprint author), Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. EM j.k.hillier@open.ac.uk RI Green, Simon/C-7408-2009; OI KEMPF, SASCHA/0000-0001-5236-3004 NR 63 TC 19 Z9 19 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 EI 1090-2643 J9 ICARUS JI Icarus PD OCT PY 2007 VL 190 IS 2 BP 643 EP 654 DI 10.1016/j.icarus.2007.03.024 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900025 ER PT J AU Hadameik, E Renard, JB Rietmeijer, F Levasseur-Regourd, AC Hill, HGM Karner, JM Nuth, JA AF Hadameik, E. Renard, J.-B. Rietmeijer, Ftm. Levasseur-Regourd, A. C. Hill, H. G. M. Karner, J. M. Nuth, J. A. TI Light scattering by fluffy Mg-Fe-SiO and C mixtures as cometary analogs (PROGRA(2) experiment) SO ICARUS LA English DT Article DE comets; dust; mineralogy; polarimetry ID INTERPLANETARY DUST PARTICLES; METASTABLE EUTECTIC CONDENSATION; SOLAR-SYSTEM BODIES; LABORATORY MEASUREMENTS; IMAGING POLARIMETRY; SILICATE MINERALOGY; OPTICAL-PROPERTIES; ORGANIC-MATTER; HALE-BOPP; POLARIZATION AB Cometary particles mainly consist of silicates and carbon compounds; they seem to be fluffy aggregates of tiny grains, as found in some IDPs. The linear polarization of the scattered light is an efficient method to characterize their physical properties. Laboratory simulations of light scattering by cometary analog particles help to disentangle different physical parameters by comparison with observational data. We present here polarization laboratory results with nine samples levitating particles: five samples of vapor-condensed magnesiosilica, one ferrosilica smoke, a mixture of magnesio-ferrosilica smokes, one mixture of ferrosilica with carbon and one mixture of magnesio-ferrosilica with carbon. The phase curves are bell-shaped with a maximum polarization at a phase range of (80 degrees- 100 degrees). A shallow negative branch can be present at phase angles smaller than 20 degrees. The different characteristics of the phase curves are discussed considering the size and the structure of the constituent grains and the size of the particles. For the five magnesiosilica samples, the maximum in polarization is in the 40% range (close to cometary values), and no wavelength dependence is detected; the negative branch, whose presence seems to be linked to the presence of large aggregates of fine silica (SiO(2)) grains, does not always exist. For the ferrosilica smoke, the maximum in polarization is about 30% in red light (632.8 nm) and 40% in green light (543.5 nm); the negative branch occurs for phase angles smaller than 20 degrees. For the two mixtures with carbon black, the polarization spectral gradient is positive, as expected for cometary analog particles. Finally, the phase curves obtained for agglomerates of magnesio-ferrosilica and carbon (expected to be the main components of cometary particles) are comparable to those obtained by remote observations of dust in cometary comae. (C) 2007 Elsevier Inc. All rights reserved. C1 Univ Paris 06, UMR 7620 SA IPSL, F-91371 Verrieres Le Buisson, France. CNRS, LPCE, F-45071 Orleans 2, France. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Int Space Univ, F-67400 Illkirch Graffenstaden, France. Univ New Mexico, Inst Meteorit, Albuquerque, NM 87131 USA. NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP Hadameik, E (reprint author), Univ Paris 06, UMR 7620 SA IPSL, BP 3, F-91371 Verrieres Le Buisson, France. EM edith.hadamcik@aerov.jussieu.fr RI Nuth, Joseph/E-7085-2012 NR 64 TC 23 Z9 23 U1 0 U2 1 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 OCT PY 2007 VL 190 IS 2 BP 660 EP 671 DI 10.1016/j.icarus.2007.03.010 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216KW UT WOS:000249877900027 ER PT J AU Bayard, DS Neat, G AF Bayard, David S. Neat, Gregory TI Performance characterization of a stellar interferometer - Identification of sensor noise models from empirical data SO IEEE CONTROL SYSTEMS MAGAZINE LA English DT Article ID MISSION RP Bayard, DS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM david.bayard@jpl.nasa.gov NR 24 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 1066-033X J9 IEEE CONTR SYST MAG JI IEEE Control Syst. Mag. PD OCT PY 2007 VL 27 IS 5 BP 90 EP 108 DI 10.1109/MCS.2007.904654 PG 19 WC Automation & Control Systems SC Automation & Control Systems GA 212UZ UT WOS:000249623600011 ER PT J AU Hu, YX Vaughan, M Liu, ZY Powell, K Rodier, S AF Hu, Yongxiang Vaughan, Mark Liu, Zhaoyan Powell, Kathleen Rodier, Sharon TI Retrieving optical depths and lidar ratios for transparent layers above opaque water clouds from CALIPSO lidar measurements SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS LA English DT Article DE aerosols; algorithms; clouds; laser radar ID MULTIPLE-SCATTERING; BACKSCATTER; DEPOLARIZATION; EXTINCTION AB For measurements that are made by the CALIPSO lidar, the layer-integrated attenuated backscatter of opaque water clouds gamma'(water,O) can be accurately estimated for those cases wa for which there is no overlying aerosol or cloud layer. When transparent overlying layers of clouds or aerosols are present, the layer-integrated attenuated backscatter that is measured for the water cloud is reduced by a factor that is equal to the two-way transmittance of the upper layer. Because the layer-integrated depolarization ratio can be used to obtain an independent estimate of y'(water),(O), we can subsequently derive both the optical depth and an estimate of the layer-averaged lidar ratio of the overlying layer. C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. Sci Syst & Aplicat Inc, Hampton, VA 23666 USA. Natl Inst Aerosp, Hampton, VA 23666 USA. RP Hu, YX (reprint author), NASA Langley Res Ctr, Hampton, VA 23681 USA. EM Yongxiang.Hu-1@nasa.gov; mark.a.vaughan@nasa.gov; zliu@nianet.org; kathleen.a.powell@nasa.gov; sharon.d.rodier@nasa.gov RI Liu, Zhaoyan/A-9604-2009; Liu, Zhaoyan/B-1783-2010; Hu, Yongxiang/K-4426-2012 OI Liu, Zhaoyan/0000-0003-4996-5738; NR 12 TC 27 Z9 27 U1 1 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1545-598X J9 IEEE GEOSCI REMOTE S JI IEEE Geosci. Remote Sens. Lett. PD OCT PY 2007 VL 4 IS 4 BP 523 EP 526 DI 10.1109/LGRS.2007.901085 PG 4 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 223RL UT WOS:000250389900005 ER PT J AU Barsi, JA Hook, SJ Schott, JR Raqueno, NG Markham, BL AF Barsi, Julia A. Hook, Simon J. Schott, John R. Raqueno, Nina G. Markham, Brian L. TI Landsat-5 thematic mapper thermal band calibration update SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS LA English DT Article DE band 6; calibration; landsat; thematic mapper (TM); thermal; validation ID SURFACE-TEMPERATURE AB The Landsat-5 Thematic Mapper (TM) has been operational since 1984. For much of its life, the calibration.of TM has been neglected, but recent efforts are attempting to monitor stability and absolute calibration. This letter focuses on the calibration of the TM thermal band from 1999 to the present. Initial studies in the first two years of the TM mission showed that the thermal band was calibrated within the error in the calibration process (+/- 0.9 K at 300 K). The calibration was not rigorously monitored again until 1999. While the internal calibrator has behaved as expected, recent vicarious calibration results show a significant offset error of 0.092 W/m(2) center dot sr center dot mu m or about 0.68 K at 300 K. This offset error was corrected on April 2, 2007 within the U.S. processing system through the modification of a calibration coefficient for all data acquired on or after April 1, 1999. Users can correct their own Level-1 data processed prior to April 2, 2007, by adding 0.092 W/m(2) center dot sr center dot mu m to their radiance level products. The state of the calibration between 1985 and 1999 is unknown; no changes for data acquired in those years are being recommended here. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Rochester Inst Technol, Ctr Imaging Sci, Rochester, NY 14623 USA. RP Barsi, JA (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. EM julia.barsi@nasa.gov RI Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 8 TC 22 Z9 23 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1545-598X J9 IEEE GEOSCI REMOTE S JI IEEE Geosci. Remote Sens. Lett. PD OCT PY 2007 VL 4 IS 4 BP 552 EP 555 DI 10.1109/LGRS.2007.896322 PG 4 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 223RL UT WOS:000250389900011 ER PT J AU Agarwal, A El-Askary, HM El-Ghazawi, T Kafatos, M Le-Moigne, J AF Agarwal, Abhishek El-Askary, Hesham Mohamed El-Ghazawi, Tarek Kafatos, Menas Le-Moigne, Jacqueline TI Hierarchical PCA techniques for fusing spatial and spectral observations with application to MISR and monitoring dust storms SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS LA English DT Article DE data fusion; dust storms; Multiangle Imaging SpectroRadiometer (MISR); principal component analysis (PCA) ID IMAGE FUSION AB In this letter, we propose hierarchical principal component analysis (HPCA) techniques for fusing spatial and spectral data, and compare them to direct principal component analysis (DPCA) over Multiangle Imaging SpectroRadiometer (MISR) data. It is shown that the proposed methods are significantly faster than DPCA. In case of DPCA, we merge the 20 different images resulting from the four spectral bands over the nadir and the four forward angles. In the hierarchical case, we first merge the information from the four spectral camera bands; then, we integrate the spatial information from the five cameras in the second step (or vice versa) by applying principal component analysis (PCA) twice. The classification results show that fused data using HPCA compare favorably to DPCA or to classification using the original data. This is because applying PCA to one particular data domain (e.g., spectral data followed by spatial data or vice versa) tends to better remove redundancies and enhance features within that domain. In addition, classification through hierarchical data fusion results in computational savings over the other methods. C1 Univ Alexandria, Dept Environm Sci, Alexandria 21522, Moharam Bek, Egypt. NARSS, Cairo, Egypt. George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Agarwal, A (reprint author), Univ Alexandria, Dept Environm Sci, Alexandria 21522, Moharam Bek, Egypt. EM agarwala@gwu.edu; helaskar@gmu.edu; tarek@gwu.edu; mkafatos@gmu.edu; lemoigne@cesdis.gsfc.nasa.gov RI El-Askary, Hesham/B-7762-2010; OI El-Askary, Hesham/0000-0002-9876-3705 NR 13 TC 6 Z9 6 U1 0 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1545-598X J9 IEEE GEOSCI REMOTE S JI IEEE Geosci. Remote Sens. Lett. PD OCT PY 2007 VL 4 IS 4 BP 678 EP 682 DI 10.1109/LGRS.2007.904467 PG 5 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 223RL UT WOS:000250389900037 ER PT J AU Huang, J Hussein, ZA Petros, A AF Huang, John Hussein, Ziad A. Petros, Argy TI A VHF microstrip antenna with wide-bandwidth and dual-polarization for sea ice thickness measurement SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE dual-polarization; VHF microstrip antenna; wideband AB A VHF microstrip patch antenna was developed to achieve a bandwidth of 45 MHz (30%) from 127 to 172 MHz with dual-linear-polarization capability. This microstrip antenna, having a size of 117 cm x 117 cm x 27 cm, used low-dielectric-constant foam substrates and dual-stacked patches with capacitive probe feeds to achieve the required wide bandwidth. Four such capacitive feeds were used to achieve dual polarizations with less than -20 dB of cross-polarization level. Twenty-four shorting pins were uniquely used here on the lower patch to achieve 40 dB of isolation between the two polarization ports. This antenna has a measured gain of 8.5 dB at 137 MHz and 10.3 dB at 162 MHz. One advantage observed here at the low frequencies of VHF is that more electrical structures can be easily integrated into the microstrip antenna to improve its performance. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA. Wireless Inc, Lake Worth, FL 33463 USA. RP Huang, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM john.huang@jpl.nasa.gov NR 5 TC 5 Z9 6 U1 0 U2 2 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 OCT PY 2007 VL 55 IS 10 BP 2718 EP 2722 DI 10.1109/TAP.2007.905920 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 220SV UT WOS:000250178500010 ER PT J AU Vancil, B Mueller, R Hawken, KW Wintucky, EG Kory, CL Lockwood, L AF Vancil, Bernard Mueller, Robert Hawken, Kenneth W. Wintucky, Edwin G. Kory, Carol L. Lockwood, Larry TI A medium power electrostatically focused multiple-beam klystron SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE electrostatic focusing; klystron; microwave amplifier; multiple-beam klystron AB This paper presents data on a new device, a 7-beam, electrostatically focused klystron oscillator/amplifier with planned output of 2-kW continuous wave (CW) at 5.8 GHz for an RF-excited ion thruster. An abridged presentation of this paper was given at the International Vacuum Electronics Conference/International Vacuum Electron Sources Conference (IVEC/IVESC) 2006 Conference in Monterey, CA. Advantages over conventional magnetic focusing are discussed. A tube was constructed that exhibited expected performance. It produced about 500 W with three beams at saturation and was operated as both an oscillator and an amplifier. DC beam transmission was 99% but degraded rapidly at saturation. We discuss ways to mitigate this problem. Cavity gaps were used as focus lenses by applying a de voltage across them, and this improved overall beam focusing. A technique for splitting cavities without lowering Q is presented. An unconventional construction technology was employed and is described. C1 E Beam Inc, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Beaverton, OR 97007 USA. Analex Corp, Cleveland, OH 44142 USA. RP Vancil, B (reprint author), E Beam Inc, Cleveland, OH 44135 USA. EM bernie@ebeaminc.com NR 8 TC 0 Z9 0 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD OCT PY 2007 VL 54 IS 10 BP 2582 EP 2588 DI 10.1109/TED.2007.904586 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 216UI UT WOS:000249904100002 ER PT J AU Hudson, D Piepmeier, JR Long, DG AF Hudson, Derek Piepmeier, Jeffrey R. Long, David G. TI Polarization rotation correction in radiometry: An error analysis SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT International Geoscience and Remote Sensing Symposium CY JUL 31-AUG 04, 2006 CL Denver, CO DE Faraday effect; microwave polarimetry; polarization ID FARADAY-ROTATION; CALIBRATION; MIRAS AB Yueh proposed a method of using the third Stokes parameter Tu to correct brightness temperatures such as T, and T-h for polarization rotation. This paper presents an extended error analysis of the estimation of T-v, T-h, and T-Q T-v - T-h by Yueh's method. In order to carry out the analysis, we first develop a forward model of polarization rotation that accounts for the random nature of thermal radiation, receiver noise, and (to first order) calibration. Analytic formulas are then derived for the bias, standard deviation (STD), and root-mean-square error (RMSE) of estimated T-Q, T-v,T- and T-h, as functions of scene and radiometer parameters. These formulas are validated through independent calculation via Monte Carlo simulation. Examination of the formulas reveals that: 1) natural T-U from planetary surface radiation, of the magnitude expected on Earth at L-band, has a negligible effect on correction for polarization rotation; 2) RMSE is a function of rotation angle Omega, but the value of Omega that minimizes RMSE is not known prior to instrument fabrication; and 3) if residual calibration errors can be sufficiently reduced via postlaunch calibration, then Yueh's method reduces the error incurred by polarization rotation to negligibility. C1 Brigham Young Univ, Dept Elect & Comp Engn, Provo, UT 84602 USA. NASA, Goddard Space Flight Ctr, Microwave Instrument Technol Branch, Greenbelt, MD 20771 USA. RP Hudson, D (reprint author), Brigham Young Univ, Dept Elect & Comp Engn, Provo, UT 84602 USA. EM dlh8@et.byu.edu RI Long, David/K-4908-2015 OI Long, David/0000-0002-1852-3972 NR 18 TC 2 Z9 3 U1 0 U2 1 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 OCT PY 2007 VL 45 IS 10 BP 3212 EP 3223 DI 10.1109/TGRS.2007.898438 PG 12 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 215GF UT WOS:000249795600025 ER PT J AU Gwo, DH AF Gwo, Dz-Hung TI Geometric effects due to quadrature phase-sensitive detection: Artifact minimization and removal schemes for spectroscopic lineshape measurement SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE Cauchy integral; Chebyshev polynomial; convolution; Dirac delta function; lock-in amplifier; magnetic resonance; modulation; phase-sensitive detection (PSD) ID LINE SHAPES AB An integral operator is defined to simulate the quadrature phase-sensitive detection. (PSD) of a time-independent characteristic function (e.g., spectroscopic lineshapes in magnetic resonance), with its dependent variablemodulated and scanned during the detection. This integral operation is equivalent to a convolution, with its kernel determined by the modulation function and the demodulation order. The convolution kernel results from the corresponding. PSD as applied to the Dirac delta function. The convolution form not only facilitates our understanding of the geometric effects due to the quadrature and the nonquadrature PSD but also indicates hardware schemes that are capable of accurately approximating or directly measuring the functional form that is being probed. These schemes involve no a priori assumptions such as those required in conventional post-PSD data manipulation to approximate true lineshapes. In the case of simisoidal modulation, the significance of simultaneous multichannel demodulations at all even or all odd harmonics within the frequency bandwidth is presented. Unconventional PSD schemes using square-wave and sawtooth-wave modulations are also discussed. As an aside for mathematics, the PSD convolution kernel corresponds to a transform between two compact-support functions; it generates an infinite set of basis-function sets, with the set of the Chebyshev polynomials being a special case. C1 Stanford Univ, NASA, Stanford Grav Probe B GPB Relat Mission, Stanford, CA 94305 USA. RP Gwo, DH (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM gwo1@llnl.gov NR 8 TC 0 Z9 0 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 2007 VL 56 IS 5 BP 1725 EP 1733 DI 10.1109/TIM.2007.903577 PG 9 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 212TM UT WOS:000249619700029 ER PT J AU Wollack, EJ Fixsen, DJ Kogut, A Limon, M Mirel, P Singal, J AF Wollack, E. J. Fixsen, D. J. Kogut, A. Limon, M. Mirel, P. Singal, J. TI Radiometric-waveguide calibrators SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE calorimeters and power measurement standards; cryogenic instrumentation; loaded waveguides; microwave absorbers; terminations; and reference loads; waveguide components ID THERMAL NOISE STANDARDS; GHZ AB We describe the electromagnetic and thermal design, performance, and fabrication for two types of radiometric-waveguide load calibrators. A simple theory is presented and used to minimize the total volume of the absorber structure. These devices have been used from room temperature to below 4 K in microwave to millimeter wavebands. The estimated precision of the calibrator is better,than 1 mK absolute at temperatures near 2.7 K. C1 NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. RP Wollack, EJ (reprint author), NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. EM edward.j.wollack@nasa.gov RI Wollack, Edward/D-4467-2012 OI Wollack, Edward/0000-0002-7567-4451 NR 19 TC 10 Z9 10 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 2007 VL 56 IS 5 BP 2073 EP 2078 DI 10.1109/TIM.2007.903646 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 212TM UT WOS:000249619700074 ER PT J AU Kooi, JW Kovacs, A Sumner, MC Chattopadhyay, G Ceria, R Miller, D Bumble, B Leduc, HG Stern, JA Phillips, TG AF Kooi, Jacob W. Kovacs, Attila Sumner, Matthew C. Chattopadhyay, Goutam Ceria, Riley Miller, Dave Bumble, Bruce LeDuc, Henry G. Stern, Jeffrey A. Phillips, Tom G. TI A 275-425-GHz tunerless waveguide receiver based on AlN-barrier SIS technology SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE Allan variance; AIN tunnel barrier; broadband; waveguide transition; dc break; heterodyne receiver; high current; density IF match; multiple Andreev reflection (MAR); planar; bandpass filter; shot noise; superconducting-insulator-superconducting; (SIS) mixer; system stability ID HETERODYNE INSTRUMENTATION UPGRADE; MICROSTRIP TRANSITION; LINE SURVEY; SHOT-NOISE; GHZ; DESIGN; PROBE; MIXERS AB We report on a 275-425-GHz tunerless waveguide receiver with a 3.5-8-GHz IF. As the mixing element, we employ a high-current-density Nb-AIN-Nb superconducting-insulatingsuperconducting (SIS) tunnel junction. Thanks to the combined use of AIN-barrier SIS technology and a broad bandwidth waveguide to thin-film microstrip transition, we are able to achieve an unprecedented 43% instantaneous bandwidth, limited by the receiver's corrugated feedhorn. The measured double-sideband (DSB) receiver noise temperature, uncorrected for optics loss, ranges from 55 K at 275 GHz, 48 K at 345 GHz, to 72 K at 425 GHz. In this frequency range, the mixer has a DSB conversion loss of 2.3 +/- 1 dB. The intrinsic mixer noise is found to vary between 17-19 K, of which 9 K is attributed to shot noise associated with leakage current below the gap. To improve reliability, the IF circuit and bias injection are entirely planar by design. The instrument was successfully installed at the Caltech Submillimeter Observatory (CSO), Mauna Kea, III, in October 2006. C1 CALTECH, Submilimeter Astron & Instrument Grp, Pasadena, CA 91125 USA. Max Planck Inst Radioastron, D-53121 Bonn, Germany. Jet Prop Lab, Pasadena, CA 91109 USA. RP Kooi, JW (reprint author), CALTECH, Submilimeter Astron & Instrument Grp, Pasadena, CA 91125 USA. EM kooi@submm.caltech.edu; attila@submm.caltech.edu; sumner@submm.caltech.edu; goutam@submm.caltech.edu; davem@submm.caltech.edu; Bruce.Bumble@jpl.nasa.gov; leduc@jpl.nasa.gov; Jeffrey.Stern@jpl.nasa.gov; tgp@submm.caltech.edu RI Kovacs, Attila/C-1171-2010 OI Kovacs, Attila/0000-0001-8991-9088 NR 56 TC 16 Z9 16 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD OCT PY 2007 VL 55 IS 10 BP 2086 EP 2096 DI 10.1109/TMTT.2007.905503 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA 223MO UT WOS:000250375000011 ER PT J AU Siqueira, P Ahmed, R Wirth, JW Bachmann, A AF Siqueira, Paul Ahmed, Razi Wirth, John W. Bachmann, Alex TI Variable precision two-channel phase, amplitude, and timing measurements for radar interferometry and polarimetry SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE interferometry; phase measurement; polarimetry; synthetic aperture radar ID TIME-DELAY AB In this paper, we present a time-domain method for estimating the phase, amplitude, and timing of a test signal, referenced either to a theoretical version of the signal, or to another signal undergoing a similar transformation as the measured signal. The use of time-domain basis for this method allows for its direct application to data samples collected by a digital oscilloscope or a dedicated A/D converter, and precludes the need for conversion into in-phase and quadrature components. The estimation process described in this paper is based on a maximum likelihood formulation, which allows for the estimate performance to be related to errors associated with sampling and is shown to achieve the Cramer-Rao lower bound for variance. Measurements such as the ones described in this paper are important for characterizing interferometric and polarimetric radar systems, as well as for determining the number of observations necessary for achieving a given degree of accuracy in the measurement. By including a statistical description of the estimation process, we enable the ability for using the technique for evaluating hypotheses describing the measurement error model. This last point is critical because it creates a mechanism for accepting or rejecting system model scenarios based on the signal-to-noise ratio and the number of digitized samples. C1 Univ Massachusetts, Dept Elect & Comp Engn, Amherst, MA 01002 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. RP Siqueira, P (reprint author), Univ Massachusetts, Dept Elect & Comp Engn, Amherst, MA 01002 USA. EM siqueira@ecs.umass.edu; ahmed@mirsl.ecs.umass.edu; jwirth@jpl.nasa.gov; bachmann@jpl.nasa.gov RI Siqueira, Paul/D-9760-2016 OI Siqueira, Paul/0000-0001-5781-8282 NR 21 TC 5 Z9 5 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD OCT PY 2007 VL 55 IS 10 BP 2248 EP 2256 DI 10.1109/TMTT.2007.906543 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 223MO UT WOS:000250375000029 ER PT J AU Nam, S Ahn, HS Allison, P Bagliesi, MG Barbier, L Beatty, JJ Bigongiari, G Brandt, TJ Jeon, JA Childers, JT Conklin, NB Couto, S DuVernois, MA Ganel, O Han, JH Kim, KC Lee, MH Lutz, L Maestro, P Malinine, A Marrocchesi, PS Minnick, S Zinn, SY Mognet, SI Nutter, S Park, IH Park, NH Seo, ES Sina, R Walpole, P Wu, J Yang, J Yoon, YS Zei, R AF Nam, S. Ahn, H. S. Allison, P. Bagliesi, M. G. Barbier, L. Beatty, J. J. Bigongiari, G. Brandt, T. J. Jeon, J. A. Childers, J. T. Conklin, N. B. Couto, S. DuVernois, M. A. Ganel, O. Han, J. H. Kim, K. C. Lee, M. H. Lutz, L. Maestro, P. Malinine, A. Marrocchesi, P. S. Minnick, S. Zinn, S. Y. Mognet, S. I. Nutter, S. Park, I. H. Park, N. H. Seo, E. S. Sina, R. Walpole, P. Wu, J. Yang, J. Yoon, Y. S. Zei, R. TI Performance of a dual layer silicon charge detector during CREAM balloon flight SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE balloon payload; charge measurement; cosmic rays; silicon sensors ID COSMIC-RAY ENERGETICS; KNEE AB The balloon-borne cosmic-ray experiment CREAM (Cosmic Ray Energetics And Mass) has completed two flights in Antarctica, with a combined duration of 70 days. One of the detectors in the payload is the SCD (Silicon Charge Detector) that measures the charge of high energy cosmic rays. The SCD was assembled with silicon sensors. A sensor is a 4 x 4 array of DC-coupled PIN diode pixels with the total active area of 21 x 16 mm(2). The SCD used during the first flight (December 2004-January 2005) was a single layer device, then upgraded to a dual layer device for the second flight (December 2005-January 2006), covering the total sensitive area of 779 x 795 mm(2). Flight data demonstrated that adding a second layer improved SCD performance, showing excellent particle charge resolution. With a total dissipation of 136 W for the dual layer system, special care was needed in designing thermal paths to keep the detector temperature within its operational range. As a consequence, flight temperatures of the SCD, even at diurnal maximum were kept below 38 degrees C. The SCD mechanical structure was designed to minimize the possibility of damage to the sensors and electronics from the impacts of parachute deployment and landing. The detector was recovered successfully following the flight and is being refurbished for the next flight in 2007. Details of construction, operation, and performance are presented for the dual-layered SCD flown for the second CREAM flight. C1 Ewha Womans Univ, Dept Phys, Seoul 120750, South Korea. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Siena, Dept Phys, I-53100 Siena, Italy. Ist Nazl Fis Nucl, I-53100 Siena, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Kent State Univ, Dept Phys, New Philadelphia, OH 44663 USA. No Kentucky Univ, Dept Phys & Geol, Highland Hts, KY 41076 USA. RP Nam, S (reprint author), Ewha Womans Univ, Dept Phys, Seoul 120750, South Korea. EM swnam@ewha.ac.kr; swnam@ewha.ac.kr; swnam@ewha.ac.kr; swnam@ewha.ac.kr; swnam@ewha.ac.kr RI maestro, paolo/E-3280-2010; Marrocchesi, Pier Simone/N-9068-2015; Yoon, Young Soo/O-8580-2014; Beatty, James/D-9310-2011; OI maestro, paolo/0000-0002-4193-1288; Marrocchesi, Pier Simone/0000-0003-1966-140X; Yoon, Young Soo/0000-0001-7023-699X; Beatty, James/0000-0003-0481-4952; Bigongiari, Gabriele/0000-0003-3691-0826; Seo, Eun-Suk/0000-0001-8682-805X NR 16 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 2007 VL 54 IS 5 BP 1743 EP 1747 DI 10.1109/TNS.2007.906407 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 222RD UT WOS:000250313700005 ER PT J AU Farhoomand, J Sisson, D Beeman, J AF Farhoomand, Jam Sisson, David Beeman, Jeff TI A low noise 2 x 16 Ge : Sb focal-plane array: Paving the way for large format FPAs for far IR astronomy SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article DE Germanium; far IR; submillimeter; photoconductor; FPA; CTIA ID INFRARED OBSERVATORY SAFIR; SIRTF; PERFORMANCE; MULTIPLEXER; DETECTORS; MISSION; DESIGN AB Future astronomical instruments call for large format and high sensitivity far infrared focal-plane arrays to meet their science objectives. Arrays as large as 128 x 128 with sensitivities equal to or better than 10(-18) W/root Hz are set as targets for the far IR instruments to be developed within the next 10 years. These seemingly modest goals present a not-so-modest quantum leap for far IR detector technology whose progress is hampered by a number of complexities; chief among them the development of low noise readouts operating at deep cryogenic temperatures and a viable hybridization scheme suitable for far IR detectors. In an effort to incrementally develop large-format photoconductor arrays, we have fabricated a 2 x 16 Ge:Sb array using the SBRC190 readout-a cryogenic 1 x 32 CTIA readout multiplexer initially developed for SOFIA's AIRES instrument. In this paper we report the results of the extensive parametric tests performed on this array showing an impressive noise performance of 2.2 x 10(-18) W/root Hz and a DQE of 0.41 despite some design limitations. With such an encouraging performance, this prototype array will serve as a platform for our future developmental effort. (c) 2007 Elsevier B.V. All rights reserved. C1 TechnoSci Corp, Palo Alto, CA 94306 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Farhoomand, J (reprint author), TechnoSci Corp, POB 60658, Palo Alto, CA 94306 USA. EM jfarhoomand@mail.arc.nasa.gov NR 24 TC 3 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD OCT PY 2007 VL 51 IS 2 BP 102 EP 112 DI 10.1016/j.infrared.2007.02.001 PG 11 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 227KH UT WOS:000250655100004 ER PT J AU Matthies, L Maimone, M Johnson, A Cheng, Y Willson, R Villalpando, C Goldberg, S Huertas, A Stein, A Angelova, A AF Matthies, Larry Maimone, Mark Johnson, Andrew Cheng, Yang Willson, Reg Villalpando, Carlos Goldberg, Steve Huertas, Andres Stein, Andrew Angelova, Anelia TI Computer vision on Mars SO INTERNATIONAL JOURNAL OF COMPUTER VISION LA English DT Article DE stereo vision; obstacle detection; visual odometry; visual velocity estimation; slip prediction; planetary exploration ID MOTION ESTIMATION SYSTEM; EXPLORATION ROVERS; VISUAL ODOMETRY; MOBILE ROBOTS; CMU NAVLAB; PROGRAM; STEREO; PERCEPTION; MACHINE; AMBLER AB Increasing the level of spacecraft autonomy is essential for broadening the reach of solar system exploration. Computer vision has and will continue to play an important role in increasing autonomy of both spacecraft and Earth-based robotic vehicles. This article addresses progress on computer vision for planetary rovers and landers and has four main parts. First, we review major milestones in the development of computer vision for robotic vehicles over the last four decades. Since research on applications for Earth and space has often been closely intertwined, the review includes elements of both. Second, we summarize the design and performance of computer vision algorithms used on Mars in the NASA/JPL Mars Exploration Rover (MER) mission, which was a major step forward in the use of computer vision in space. These algorithms did stereo vision and visual odometry for rover navigation and feature tracking for horizontal velocity estimation for the landers. Third, we summarize ongoing research to improve vision systems for planetary rovers, which includes various aspects of noise reduction, FPGA implementation, and vision-based slip perception. Finally, we briefly survey other opportunities for computer vision to impact rovers, landers, and orbiters in future solar system exploration missions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. CALTECH, Pasadena, CA 91125 USA. RP Matthies, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM larry.matthies@jpl.nasa.gov; mark.maimone@jpl.nasa.gov; andrew.johnson@jpl.nasa.gov; yang.cheng@jpl.nasa.gov; reg.willson@jpl.nasa.gov; carlos.villalpando@jpl.nasa.gov; steve.goldberg@jpl.nasa.gov; andres.huertas@jpl.nasa.gov; anstein@cmu.edu; anelia@caltech.edu NR 95 TC 53 Z9 68 U1 0 U2 26 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0920-5691 J9 INT J COMPUT VISION JI Int. J. Comput. Vis. PD OCT PY 2007 VL 75 IS 1 BP 67 EP 92 DI 10.1007/s11263-007-0046-z PG 26 WC Computer Science, Artificial Intelligence SC Computer Science GA 197RM UT WOS:000248574200005 ER PT J AU Ladner, R Warner, E Katikaneni, U McCreedy, F Petry, FE AF Ladner, Roy Warner, Elizabeth Katikaneni, Udaykiran McCreedy, Frank Petry, Frederick E. TI Active network architecture and management SO INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS LA English DT Article ID WEB SERVICES AB Access and retrieval of meteorological and oceanographic data from heterogeneous sources in a distributed system presents many issues. There are a number of features of the TEDServices system that illustrate active network management for such data. There is a self-aware or intelligent aspect with respect to the mechanisms for shutdown, data ordering, and propagation of data orders. Intelligent cache management and collaborative application sharing process are other features of the active network management. Additionally a very important capability is the implementation of resumable object streams, which allows either the client or server side of a request to lose network connection, regain it, and the request will continue where it left off. (C) 2007 Wiley Periodicals, Inc. C1 Stennis Space Ctr, Naval Res Lab, Stennis Space Ctr, MS 39529 USA. RP Petry, FE (reprint author), Stennis Space Ctr, Naval Res Lab, Stennis Space Ctr, MS 39529 USA. EM rladner@nrlssc.navy.mil; ewarner@nrlssc.navy.mil; ukatikan@nrlssc.navy.mil; Frank.McCreedy@nrlssc.navy.mil; fpetry@nrlssc.navy.mil RI Petry, Frederick/F-9894-2010 NR 14 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0884-8173 J9 INT J INTELL SYST JI Int. J. Intell. Syst. PD OCT PY 2007 VL 22 IS 10 BP 1123 EP 1138 DI 10.1002/int.20242 PG 16 WC Computer Science, Artificial Intelligence SC Computer Science GA 209BN UT WOS:000249363200004 ER PT J AU Yang, P Feng, Q Hong, G Kattawar, GW Wiscombe, WJ Mishchenko, MI Dubovik, O Laszlo, I Sokolik, IN AF Yang, Ping Feng, Qian Hong, Gang Kattawar, George W. Wiscombe, Warren J. Mishchenko, Michael I. Dubovik, Oleg Laszlo, Istvan Sokolik, Irina N. TI Modeling of the scattering and radiative properties of nonspherical dust-like aerosols SO JOURNAL OF AEROSOL SCIENCE LA English DT Article DE single-scattering property; nonspherical dust particle; solar and infrared radiances; remote sensing ID HIGH-FREQUENCY SCATTERING; HEXAGONAL ICE CRYSTALS; T-MATRIX METHOD; LIGHT-SCATTERING; ELECTROMAGNETIC SCATTERING; TROPOSPHERIC AEROSOLS; OPTICAL-PROPERTIES; MINERAL PARTICLES; CLIMATE; SHAPE AB The optical and radiative properties of dust particles in solar and thermal infrared regions are investigated. Dust particles are assumed to be spheres and spheroids for a comparison aimed at understanding the nonsphericity effect of these particles on the radiation at the top of a dusty atmosphere. The classical Lorenz-Mie theory is employed to compute the optical properties of spherical dust particles. To compute the single-scattering properties of spheroidal dust particles, a combination of the T-matrix method and an approximate method is used in the present study. In the approximate method, applicable to large particles, the geometric optics method is applied to the computation of the scattering phase matrix. A combination of the solution from the geometric optics method and the contribution of the so-called edge effect is used to compute the extinction efficiency of a spheroidal particle whose absorption efficiency is computed by adding the so-called above- and below-edge effect (a term from the well-known complex angular momentum theory) to the geometric optics result. Numerical results show that the results from the T-matrix method and the present approximate approach converge at a size parameter of 50 for computing the integrated scattering properties (i.e., the extinction efficiency, single-scattering albedo, and asymmetry factor). Additionally, the phase functions computed from the two methods are quite similar for size parameters larger than 40 although some considerable differences may still be noticed for other phase matfix elements. Furthermore, the effect of surface roughness on the single-scattering properties of spheroidal particles is discussed. The present radiative transfer simulations illustrate the nonsphericity effect of dust particles is significant at short wavelengths, however, not at the thermal infrared wavelengths. (c) 2007 Elsevier Ltd. All rights reserved. C1 Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Univ Lille, CNRS, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. NOAA, NESDIS, Off Res & Applicat, Suitland, MD 20746 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. RP Yang, P (reprint author), Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. EM pyang@ariel.met.tamu.edu RI Dubovik, Oleg/A-8235-2009; Laszlo, Istvan/F-5603-2010; Yang, Ping/B-4590-2011; Hong, Gang/A-2323-2012; Wiscombe, Warren/D-4665-2012; Mishchenko, Michael/D-4426-2012 OI Dubovik, Oleg/0000-0003-3482-6460; Laszlo, Istvan/0000-0002-5747-9708; Wiscombe, Warren/0000-0001-6844-9849; NR 70 TC 102 Z9 107 U1 3 U2 27 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0021-8502 EI 1879-1964 J9 J AEROSOL SCI JI J. Aerosol. Sci. PD OCT PY 2007 VL 38 IS 10 BP 995 EP 1014 DI 10.1016/j.jacrosci.2007.07.001 PG 20 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 236WO UT WOS:000251334300001 ER PT J AU Meyers, C Toutanji, H AF Meyers, Charles Toutanji, Houssarn TI Analysis of lunar-habitat structure using waterless concrete and tension glass fibers SO JOURNAL OF AEROSPACE ENGINEERING LA English DT Article AB The studies reported in this paper were undertaken to evaluate the maximum use of lunar in situ resources for surface construction, such as a habitat structure for a permanent manned lunar base. This type of activity is well into the future, but there are possible near-term applications that could utilize in situ resources for protection from radiation of surface power reactors, solar flares, and micrometeorite damage. "Waterless" concrete made of sulfur, a by-product material of oxygen and carbon extractions, is a viable alternative to hydraulic cement. Sulfur-lunar regolith concrete is an ideal material for building structures on the moon. Its availability, high strength, and durability properties make it a very attractive candidate for the development of the first lunar-construction activities. Regolith-derived glass rebar and fiber can also be used with "concrete" made with in situ regolith. Development of such habitats pose tremendous challenges that can be met by the combination of innovative design with cutting-edge technologies that are appropriate for planetary surface habitats with multiple applications for Earth and beyond. C1 Univ Alabama, Dept Civil & Environm Engn, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Meyers, C (reprint author), Univ Alabama, Dept Civil & Environm Engn, Huntsville, AL 35899 USA. EM charles.meyers@nasa.gov; toutanji@cee.uah.edu NR 15 TC 7 Z9 7 U1 1 U2 21 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0893-1321 J9 J AEROSPACE ENG JI J. Aerosp. Eng. PD OCT PY 2007 VL 20 IS 4 BP 220 EP 226 DI 10.1061/(ASCE)0893-1321(2007)20:4(220) PG 7 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA 212VD UT WOS:000249624000003 ER PT J AU Tamura, T Ohshima, KI Markus, T Cavalieri, DJ Nihashi, S Hirasawa, N AF Tamura, Takeshi Ohshima, Kay I. Markus, Thorsten Cavalieri, Donald J. Nihashi, Sohey Hirasawa, Naohiko TI Estimation of thin ice thickness and detection of fast ice from SSM/I data in the Antarctic Ocean SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SEA-ICE; COASTAL POLYNYAS; EAST ANTARCTICA; SATELLITE DATA; WEDDELL SEA; IMAGERY AB Antarctic coastal polynyas are important areas of high sea ice production and dense water formation, and thus their detection including an estimate of thin ice thickness is essential. In this paper, the authors propose an algorithm that estimates thin ice thickness and detects fast ice using Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager (SSM/I) data in the Antarctic Ocean. Detection and estimation of sea ice thicknesses of <0.2 m are based on the SSM/I 85- and 37-GHz polarization ratios (PR85 and PR37) through a comparison with sea ice thicknesses estimated from the Advanced Very High Resolution Radiometer (AVHRR) data. The exclusion of data affected by atmospheric water vapor is discussed. Because thin ice and fast ice (specifically ice shelves, glacier tongues, icebergs, and landfast ice) have similar PR signatures, a scheme was developed to separate these two surface types before the application of the thin ice algorithm to coastal polynyas. The probability that the algorithm correctly distinguishes thin ice from thick ice and from fast ice is similar to 95%, relative to the ice thicknesses estimated from AVHRR. Although the standard deviation of the difference between the thin ice thicknesses estimated from the SSM/I algorithm and AVHRR is similar to 0.05 m and thus not small, the estimated ice thicknesses from the microwave algorithm appear to have small biases and the accuracies are independent of region and season. A distribution map of thin ice occurrences derived from the SSM/I algorithm represents the Ross Sea coastal polynya being by far the largest among the Antarctic coastal polynyas; the Weddell Sea coastal polynyas are much smaller. Along the coast of East Antarctica, coastal polynyas frequently form on the western side of peninsulas and glacier tongues, downstream of the Antarctic Coastal Current. C1 Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido 060, Japan. Hokkaido Univ, Inst Low Temp Sci, Sapporo, Hokkaido 060, Japan. NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA. Natl Inst Polar Res, Tokyo 173, Japan. RP Tamura, T (reprint author), Hokkaido Univ, Inst Low Temp Sci, Kita Ku, N19W8, Sapporo, Hokkaido 0600819, Japan. EM tamutake@lowtem.hokudai.ac.jp RI Markus, Thorsten/D-5365-2012; Ohshima, Kay/D-6909-2012 NR 34 TC 52 Z9 54 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD OCT PY 2007 VL 24 IS 10 BP 1757 EP 1772 DI 10.1175/JTECH2113.1 PG 16 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 218HG UT WOS:000250006000006 ER PT J AU Durden, SL Fischman, MA Johnson, RA Chu, AJ Jourdan, MN Tanelli, S AF Durden, S. L. Fischman, M. A. Johnson, R. A. Chu, A. J. Jourdan, M. N. Tanelli, S. TI An FPGA-based Doppler processor for a spaceborne precipitation radar SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID FAST FOURIER-TRANSFORM; VELOCITY-MEASUREMENTS AB Measurement of precipitation Doppler velocity by spaceborne radar is complicated by the large velocity of the satellite platform. Even if successive pulses are well correlated, the velocity measurement may be biased if the precipitation target does not uniformly fill the radar footprint. It has been previously shown that the bias in such situations can be reduced if full spectral processing is used. The authors present a processor based on field-programmable gate array (FPGA) technology that can be used for spectral processing of data acquired by future spaceborne precipitation radars. The requirements for and design of the Doppler processor are addressed. Simulation and laboratory test results show that the processor can meet real-time constraints while easily fitting in a single FPGA. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Durden, SL (reprint author), CALTECH, Jet Propuls Lab, MS 300-243,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM sdurden@jpl.nasa.gov NR 13 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD OCT PY 2007 VL 24 IS 10 BP 1811 EP 1815 DI 10.1175/JTECH2086.1 PG 5 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 218HG UT WOS:000250006000010 ER PT J AU Jemison, M AF Jemison, Mae TI Career profile: Biomedical engineer - Mae Jemison SO JOURNAL OF CHEMICAL EDUCATION LA English DT Biographical-Item C1 BioSentient Corp, Houston, TX USA. NASA, Washington, DC 20546 USA. RP Jemison, M (reprint author), BioSentient Corp, Houston, TX USA. EM info@biosentient.com NR 3 TC 0 Z9 0 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD OCT PY 2007 VL 84 IS 10 BP 1569 EP 1570 PG 2 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA 210VL UT WOS:000249483600005 ER PT J AU Wylie, D Eloranta, E Spinhirne, JD Palm, SP AF Wylie, Donald Eloranta, Edwin Spinhirne, James D. Palm, Steven P. TI Comparison of cloud cover statistics from the GLAS lidar with HIRS SO JOURNAL OF CLIMATE LA English DT Article ID GAS EXPERIMENT-II; HIGH-LEVEL CLOUDS; STRATOSPHERIC AEROSOL; SAGE-II; DATASET; ISCCP; CLIMATOLOGIES; FREQUENCY AB The cloud dataset from the Geoscience Laser Altimeter System ( GLAS) lidar on the Ice, Cloud, and Land Elevation Satellite ( ICESat) spacecraft is compared to the cloud analysis of the Wisconsin NOAA High Resolution Infrared Radiation Sounder ( HIRS) Pathfinder. This is the first global lidar dataset from a spacecraft of extended duration that can be compared to the HIRS climatology. It provides an excellent source of cloud information because it is more sensitive to clouds that are difficult to detect, namely, thin cirrus and small boundary layer clouds. The second GLAS data collection period from 1 October to 16 November 2003 was used for this comparison, and a companion dataset of the same days were analyzed with HIRS. GLAS reported cloud cover of 0.70 while HIRS reported slightly higher cloud cover of 0.75 for this period. The locations where HIRS overreported cloud cover were mainly in the Arctic and Antarctic Oceans and parts of the Tropics. GLAS also confirms that upper- tropospheric clouds ( above 6.6 km) cover about 0.33 of the earth, similar to the reports from HIRS data. Generally, the altitude of the cloud tops reported by GLAS is, on average, higher than HIRS by 0.4 to 4.5 km. The largest differences were found in the Tropics, over 4 km, while in midlatitudes average differences ranged from 0.4 to 2 km. Part of this difference in averaged cloud heights comes from GLAS finding more high cloud coverage in the Tropics, 5% on average but > 13% in some areas, which weights its cloud top average more toward the high clouds than the HIRS. The diffuse character of the upper parts of high clouds over tropical oceans is also a cause for the difference in reported cloud heights. Statistics on cloud sizes also were computed from GLAS data to estimate the errors in cloud cover reported by HIRS from its 20- km field- of- view ( FOV) size. Smaller clouds are very common with one- half of all clouds being < 41 km in horizontal size. But, clouds < 41 km cover only 5% of the earth. Cloud coverage is dominated by larger clouds with one- half of the coverage coming from clouds > 1000 km. GLAS cloud size statistics also show that HIRS possibly overreports some cloud forms by 2% - 3%. Looking at groups of GLAS data 21 km long to simulate the HIRS FOV, the authors found that similar to 5% are partially filled with cloud. Since HIRS does not account for the part of the FOV without cloud, it will overreport the coverage of these clouds. However, low- altitude and optically thin clouds will not be reported by HIRS if they are so small that they do not affect the upwelling radiation in the HIRS FOV enough to trigger the threshold for cloud detection. These errors are partially offing. C1 Univ Wisconsin, Ctr Space Sci & Engn, Madison, WI 53706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wylie, D (reprint author), Univ Wisconsin, Ctr Space Sci & Engn, 1225 W Dayton St, Madison, WI 53706 USA. EM don.wylie@ssec.wisc.edu NR 26 TC 17 Z9 17 U1 0 U2 7 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 OCT PY 2007 VL 20 IS 19 BP 4968 EP 4981 DI 10.1175/JCLI4269.1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 219ST UT WOS:000250105800011 ER PT J AU Trinh, HP Chen, CP Balasubramanyam, MS AF Trinh, Huu P. Chen, C. P. Balasubramanyam, M. S. TI Numerical simulation of liquid jet atornization including turbulence effects SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article DE atomization; spray; secondary breakup; numerical modeling ID SPRAY; ATOMIZATION; BREAKUP; FLOW AB This paper describes numerical implementation and validation of a newly developed hybrid model, T-blob/T-TAB, into an existing computational fluid dynamics (CFD) program for primary and secondary breakup simulation of liquid jet atomization. This model extends two widely used models, the Kelvin-Helmholtz (KH) instability of Reitz (the "blob" model) (1987, Atomization Spray Technol., 3, pp. 309-337) and the Taylor-Analogy-Breakup (TAB) secondary droplet breakup of O'Rourke and Amsden (1987, SAE Technical Paper No. 872089) to include liquid turbulence effects. In the primary breakup model, the level of the turbulence effect on the liquid breakup depends on the characteristic scales and flow conditions at the liquid nozzle exit. Transition to the secondary breakup was modeled based on energy balance, and an additional turbulence force acted on parent drops was modeled and integrated into the TAB governing equation. Several assessment studies are presented, and the results indicate that the existing KH and TAB models tend to underpredict the product drop size and spray angle, whereas the current model provides superior results when compared to the measured data. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Dept Chem & Mat Engn, Huntsville, AL 35899 USA. RP Trinh, HP (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM Huu.P.Trinh@nasa.gov NR 18 TC 12 Z9 12 U1 0 U2 9 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 2007 VL 129 IS 4 BP 920 EP 928 DI 10.1115/1.2747253 PG 9 WC Engineering, Mechanical SC Engineering GA 223EP UT WOS:000250352700005 ER PT J AU Kobayashi, T Simon, DL AF Kobayashi, Takahisa Simon, Donald L. TI Integration of on-line and off-line diagnostic algorithms for aircraft engine health management SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 52nd ASME Turbo Expo CY MAY 14-17, 2007 CL Montreal, CANADA SP Amer Soc Mech Engineers, Int Gas Turbine Inst DE in-flight fault detection; trend monitoring; on-board engine model; Kalman filter ID GAS-PATH-ANALYSIS AB This paper investigates the integration of on-line and off-line diagnostic algorithms for aircraft gas turbine engines. The on-line diagnostic algorithm is designed for in-flight fault detection. It continuously monitors engine outputs for anomalous signatures induced by faults. The off-line diagnostic algorithm is designed to track engine health degradation over the lifetime of an engine. It estimates engine health degradation periodically over the course of the engine's life. The estimate generated by the off-line algorithm is used to "update" the on-line algorithm. Through this integration, the on-line algorithm becomes aware of engine health degradation, and its effectiveness to detect faults can be maintained while the engine continues to degrade. The benefit of this integration is investigated in a simulation environment using a nonlinear engine model. C1 ASRC Aerosp Corp, Cleveland, OH 44135 USA. Glenn Res Ctr, US Army Res Lab, Cleveland, OH 44135 USA. RP Kobayashi, T (reprint author), ASRC Aerosp Corp, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 20 TC 3 Z9 5 U1 2 U2 9 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 2007 VL 129 IS 4 BP 986 EP 993 DI 10.1115/1.2747640 PG 8 WC Engineering, Mechanical SC Engineering GA 223EP UT WOS:000250352700013 ER PT J AU Cannon, HN Stoker, CR Dunagan, SE Davis, K Gomez-Elvira, J Glass, BJ Lemke, LG Miller, D Bonaccorsi, R Branson, M Christa, S Rodriguez-Manfredi, JA Mumm, E Paulsen, G Roman, M Winterholler, A Zavaleta, JR AF Cannon, Howard N. Stoker, Carol R. Dunagan, Stephen E. Davis, Kiel Gomez-Elvira, Javier Glass, Brian J. Lemke, Lawrence G. Miller, David Bonaccorsi, Rosalba Branson, Mark Christa, Scott Antonio Rodriguez-Manfredi, Jose Mumm, Erik Paulsen, Gale Roman, Matt Winterholler, Alois Zavaleta, Jhony R. TI MARTE: Technology development and lessons learned from a mars drilling mission simulation SO JOURNAL OF FIELD ROBOTICS LA English DT Article ID ROVER FIELD EXPERIMENT; ATACAMA DESERT; CALIFORNIA; LAKE AB The NASA Mars Astrobiology Research and Technology Experiment (MARTE) performed a field test simulating a robotic drilling mission on Mars in September 2005. The experiment took place in Minas de Riotinto in southwestern Spain, a highly relevant Mars analog site. The experiment utilized a 10 m class dry auger coring drill, a robotic core sample handling system, onboard science and life detection instruments, and a borehole inspection probe, all of which were mounted to a simulated lander platform. Much of the operation of the system was automated, and the resulting data were transmitted via satellite to remote science teams for analysis. The science team used the data to characterize the subsurface geology and to search for signs of life. Based on the data being received and operational constraints, the science team also directed the daily operation of the equipment. The experiment was highly successful, with the drill reaching over 6 m in depth in 23 days of simulated mission. The science team analyzed remote sensing data obtained from 28 cores and detected biosignatures in 12 core subsamples. This experiment represents an important first step in understanding the technology and operational requirements for a future Mars drilling mission. In the past there have been numerous rover field tests that have helped guide the design and implementation of the highly successful rover missions to Mars. However, a drilling mission potentially adds a new level of complexity, and it is important to understand the associated challenges. This paper documents the design of the experimental system, highlighting some of the more important design criteria and design trades. It also discusses the results of the field testing and lists some of the key technological lessons learned. (C) 2007 Wiley Periodicals, Inc. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Mechanisms Corp, Honeybee Robot Spacecraft, New York, NY 10001 USA. Inst Nacl Tecn Aeroespacial, CSIC, Ctr Astrobiol, Madrid 28850, Spain. Univ Oklahoma, Sch Aerosp & Mech Engn, Norman, OK 73019 USA. RP Cannon, HN (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Gomez-Elvira, Javier/K-5829-2014; Rodriguez-Manfredi, Jose/L-8001-2014 OI Gomez-Elvira, Javier/0000-0002-9068-9846; Rodriguez-Manfredi, Jose/0000-0003-0461-9815 NR 37 TC 12 Z9 12 U1 1 U2 6 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 1556-4959 J9 J FIELD ROBOT JI J. Field Robot. PD OCT PY 2007 VL 24 IS 10 BP 877 EP 905 DI 10.1002/rob.20224 PG 29 WC Robotics SC Robotics GA 228YH UT WOS:000250768000006 ER PT J AU Farley, EV Murphy, JM Adkison, M Eisner, L AF Farley, E. V., Jr. Murphy, J. M. Adkison, M. Eisner, L. TI Juvenile sockeye salmon distribution, size, condition and diet during years with warm and cool spring sea temperatures along the eastern Bering Sea shelf SO JOURNAL OF FISH BIOLOGY LA English DT Article DE Bristol Bay; condition; diet; juvenile salmon ID EARLY MARINE GROWTH; ONCORHYNCHUS-NERKA; ATLANTIC SALMON; SURVIVAL RATES; CLIMATE-CHANGE; OCEAN GROWTH; COHO SALMON; ALASKA; SALAR; PINK AB Interannual variations in distribution, size, indices of feeding and condition of juvenile Bristol Bay sockeye salmon Oncorhynchus nerka collected in August to September (2000-2003) during Bering-Aleutian Salmon International Surveys were examined to test possible mechanisms influencing their early marine growth and survival. Juvenile sockeye salmon were mainly distributed within the southern region of the eastern Bering Sea, south of 57 degrees 0' N during 2000 and 2001 and farther offshore, south of 58 degrees 0' N during 2002 and 2003. In general, juvenile sockeye salmon were significantly larger (P < 0.05) and had significantly higher indices of condition (P < 0.05) during 2002 and 2003 than during 2000 and 2001. The feeding index was generally higher for age 1.0 year sockeye salmon than age 2.0 year during all years. Among-year comparisons suggested that Pacific sand lance Ammodytes hexapterus were important components of the juvenile sockeye salmon diet during 2000 and 2001 (20 to 50% of the mean wet mass) and age 0 year walleye pollock Theragra chalcogramma were important components during 2002 and 2003 (50 to 60% of the mean wet mass). Warmer sea temperatures during spring and summer of 2002 and 2003 probably increased productivity on the eastern Bering Sea shelf, enhancing juvenile sockeye salmon growth. Journal compilation (c) 2007 The Fisheries Society of the British Isles. C1 Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. Univ Alaska Fairbanks, Juneau Ctr, Sch Fisheries & Ocean Sci, Juneau, AK 99801 USA. RP Farley, EV (reprint author), Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM ed.farley@noaa.gov NR 28 TC 17 Z9 21 U1 3 U2 13 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD OCT PY 2007 VL 71 IS 4 BP 1145 EP 1158 DI 10.1111/j.1095-8649.2007.01587.x PG 14 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 221ZL UT WOS:000250265800014 ER PT J AU Santanello, JA Friedl, MA Ek, MB AF Santanello, Joseph A., Jr. Friedl, Mark A. Ek, Michael B. TI Convective planetary boundary layer interactions with the land surface at diurnal time scales: Diagnostics and feedbacks SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID SOIL-MOISTURE; ENERGY-BALANCE; MIXED-LAYER; ATMOSPHERE INTERACTION; SKIN TEMPERATURES; FLUXES; MODEL; PARAMETERIZATION; SENSITIVITY; WATER AB The convective planetary boundary layer (PBL) integrates surface fluxes and conditions over regional and diurnal scales. As a result, the structure and evolution of the PBL contains information directly related to land surface states. To examine the nature and magnitude of land-atmosphere coupling and the interactions and feedbacks controlling PBL development, the authors used a large sample of radiosonde observations collected at the southern Atmospheric Research Measurement Program-Great Plains Cloud and Radiation Testbed (ARM-CART) site in association with simulations of mixed-layer growth from a single-column PBL/land surface model. The model accurately predicts PBL evolution and realistically simulates thermodynamics associated with two key controls on PBL growth: atmospheric stability and soil moisture. The information content of these variables and their influence on PBL height and screen-level temperature can be characterized using statistical methods to describe PBL-land surface coupling over a wide range of conditions. Results also show that the first-order effects of land-atmosphere coupling are manifested in the control of soil moisture and stability on atmospheric demand for evapotranspiration and on the surface energy balance. Two principal land-atmosphere feedback regimes observed during soil moisture drydown periods are identified that complicate direct relationships between PBL and land surface properties, and, as a result, limit the accuracy of uncoupled land surface and traditional PBL growth models. In particular, treatments for entrainment and the role of the residual mixed layer are critical to quantifying diurnal land-atmosphere interactions. C1 Boston Univ, Dept Geog & Environm, Boston, MA 02215 USA. NCEP, EMC, NOAA Sci Ctr, Suitland, MD USA. RP Santanello, JA (reprint author), NASA, Goddard Space Flight Ctr, Code 614-3,Bldg 022,Room 008, Greenbelt, MD 20771 USA. EM Joseph.A.Santanello@nasa.gov RI Santanello, Joseph/D-4438-2012 OI Santanello, Joseph/0000-0002-0807-6590 NR 56 TC 40 Z9 40 U1 1 U2 14 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 OCT PY 2007 VL 8 IS 5 BP 1082 EP 1097 DI 10.1175/JHM614.1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 229HG UT WOS:000250793300008 ER PT J AU Hatamleh, O Rivero, IV Lyons, J AF Hatamleh, Omar Rivero, Iris V. Lyons, Jed TI Evaluation of surface residual stresses in friction stir welds due to laser and shot peening SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE FSW; laser peening; residual stress; shot peening; x-ray diffraction ID FATIGUE-CRACK GROWTH; ALUMINUM-ALLOY; BEHAVIOR AB The effects of laser, and shot peening on the residual stresses in friction stir welds (FSW) has been investigated. The surface residual stresses were measured at five different locations across the weld in order to produce an adequate residual stress profile. The residual stresses before and after sectioning the coupon from the welded plate were also measured, and the effect of coupon size on the residual stress relaxation was determined and characterized. Measurements indicate that residual stresses were not uniform along the welded plate, and large variation in stress magnitude could be exhibited at various locations along the FSW plate. Sectioning resulted in significant residual stress relaxation in the longitudinal direction attributed to the large change in dimensions in this direction. Overall, laser and shot peening resulted in a significant reduction in tensile residual stresses at the surface of the specimens. C1 NASA, Lyndon B Johnson Space Ctr, Structures & Dynam Branch, Houston, TX 77058 USA. Texas Tech Univ, Dept Ind Engn, Lubbock, TX 79409 USA. Univ S Carolina, Dept Mech Engn, Columbia, SC 29208 USA. RP Hatamleh, O (reprint author), NASA, Lyndon B Johnson Space Ctr, Structures & Dynam Branch, Houston, TX 77058 USA. EM omar.hatamleh-1@nasa.gov NR 12 TC 11 Z9 11 U1 3 U2 15 PU ASM INT PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD OCT PY 2007 VL 16 IS 5 BP 549 EP 553 DI 10.1007/s11665-007-9091-6 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 211QK UT WOS:000249538200006 ER PT J AU Clayton, LM Knudsen, B Cinke, M Meyyappan, M Harmon, JP AF Clayton, LaNetra M. Knudsen, Bernard Cinke, Martin Meyyappan, M. Harmon, Julie P. TI DC conductivity and interfacial polarization in PMMA/nanotube and PMMA/soot composites SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article; Proceedings Paper CT ChemOnTubes International Conference CY APR, 2006 CL Arcachon, FRANCE SP European Res Grp DE DC conductivity; PMMA; carbon nanotubes; dielectric analysis; interfacial polarization; nanocomposites ID WALLED CARBON NANOTUBES; POLYMER COMPOSITES; ELECTRIC MODULUS; NANOCOMPOSITES; RELAXATIONS; FILMS AB This work focuses on the DC conductivity and interfacial polarization of poly(methyl methacrylate) (PMMA) composites made with single wall nanotubes (SWNTs) and nanotube precursor soot. We aim to compare and contrast the behavior of the two nanofillers in an effort to determine if the precursor material imparts tunable electrical properties to PMMA. The DC activity of the polymers and composites was determined by extrapolating AC conductivity versus frequency plots to zero. Activation energies and DC conductivities were obtained through Arrhenius plots. The conductivity increased with temperature for all the samples in conjunction with viscous flow. Both nanotubes and nanosoot increased the DC conductivities. Activation energies for the SWNT decreased slightly upon the addition of nanotubes to the matrix. However, the activation energies increased with soot content in the matrix, indicating obstruction of motion or possible bridging caused by the soot. Cole-Cole plots were effectively used to determine the extent of interfacial polarization in the com posite samples. Plots shifted toward the origin with the addition of carbon nanotubes or with soot concentration indicating a Maxwell-Wagner-Sillars process. C1 Univ S Florida, Dept Chem, Tampa, FL 33620 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Harmon, JP (reprint author), Univ S Florida, Dept Chem, 4202 E Fowler Ave, Tampa, FL 33620 USA. NR 31 TC 10 Z9 10 U1 1 U2 8 PU AMER SCIENTIFIC PUBLISHERS PI VALENCIA PA 26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA SN 1533-4880 EI 1533-4899 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD OCT PY 2007 VL 7 IS 10 BP 3572 EP 3579 DI 10.1166/jnn.2007.850 PG 8 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 223QY UT WOS:000250388600036 PM 18330175 ER PT J AU Parker, PA Kowalski, SM Vining, GG AF Parker, Peter A. Kowalski, Scott M. Vining, G. Geoffrey TI Unbalanced and minimal point equivalent estimation second-order split-plot designs SO JOURNAL OF QUALITY TECHNOLOGY LA English DT Article DE box-behnken design; central composite design; equivalent estimation design; Notz design; restricted randomization; split-plot design ID RESPONSE-SURFACE DESIGNS; SECOND-ORDER DESIGNS; FACTORIAL; NUMBERS AB Restricting the randomization of hard-to-change factors in industrial experiments is often required, resulting in a split-plot design structure. From an economic perspective, these designs minimize the experimental cost by reducing the number of resets of the hard-to-change factors. In this paper, unbalanced designs are considered for cases where the subplots are relatively expensive and the experimental apparatus accommodates an unequal number of runs per whole plot. We provide construction methods for unbalanced second-order split-plot designs that possess the equivalent estimation optimality property, providing best linear unbiased estimates of the parameters, independent of the variance components. Unbalanced versions of the central composite and Box-Behnken designs are developed. For cases where the subplot cost approaches the whole-plot cost, minimal point designs are proposed and illustrated with a split-plot Notz design. C1 Minitab Inc, State Coll, PA 16801 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. RP Parker, PA (reprint author), NASA, Langley Res Ctr, Aeronaut Syst Engn Branch, Hampton, VA 23681 USA. EM peter.a.parker@nasa.gov; skowalski@minitab.com; vining@vt.edu NR 26 TC 12 Z9 14 U1 0 U2 4 PU AMER SOC QUALITY CONTROL-ASQC PI MILWAUKEE PA 600 N PLANKINTON AVE, MILWAUKEE, WI 53203 USA SN 0022-4065 J9 J QUAL TECHNOL JI J. Qual. Technol. PD OCT PY 2007 VL 39 IS 4 BP 376 EP 388 PG 13 WC Engineering, Industrial; Operations Research & Management Science; Statistics & Probability SC Engineering; Operations Research & Management Science; Mathematics GA 223YU UT WOS:000250412900007 ER PT J AU Morscher, GN Yun, HM DiCarlo, JA AF Morscher, Gregory N. Yun, Hee Mann DiCarlo, James A. TI In-plane cracking behavior and ultimate strength for 2D woven and braided melt-infiltrated SiC/SiC composites tensile loaded in off-axis fiber directions SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SIC MATRIX COMPOSITES; MECHANICAL-PROPERTIES; DAMAGE ACCUMULATION; CERAMIC COMPOSITE AB The tensile mechanical properties of ceramic matrix composites (CMC) in directions off the primary axes of the reinforcing fibers are important for the architectural design of CMC components that are subjected to multiaxial stress states. In this study, two-dimensional (2D)-woven melt-infiltrated (MI) SiC/SiC composite panels with balanced fiber content in the 0 degrees and 90 degrees directions were tensile loaded in-plane in the 0 degrees direction and at 45 degrees to this direction. In addition, a 2D triaxially braided MI SiC/SiC composite panel with a higher fiber content in the +/- 67 degrees bias directions compared with the axial direction was tensile loaded perpendicular to the axial direction tows (i.e., 23 degrees from the bias fibers). Stress-strain behavior, acoustic emission, and optical microscopy were used to quantify stress-dependent matrix cracking and ultimate strength in the panels. It was observed that both off-axis-loaded panels displayed higher composite onset stresses for through-thickness matrix cracking than the 2D-woven 0/90 panels loaded in the primary 0 degrees direction. These improvements for off-axis cracking strength can in part be attributed to higher effective fiber fractions in the loading direction, which in turn reduces internal stresses on weak regions in the architecture, e.g., minicomposite tows oriented normal to the loading direction and/or critical flaws in the matrix for a given composite stress. Both off-axis-oriented panels also showed relatively good ultimate tensile strength when compared with other off-axis-oriented composites in the literature, both on an absolute strength basis as well as when normalized by the average fiber strength within the composites. Initial implications are discussed for constituent and architecture design to improve the directional cracking of SiC/SiC CMC components with MI matrices. C1 Ohio Aerosp Inst, Cleveland, OH USA. Matech GSM, Irvine, CA USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Morscher, GN (reprint author), Ohio Aerosp Inst, Cleveland, OH USA. EM gmorscher@grc.nasa.gov NR 26 TC 21 Z9 21 U1 3 U2 25 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 2007 VL 90 IS 10 BP 3185 EP 3193 DI 10.1111/j.1551-2916.2007.01887.x PG 9 WC Materials Science, Ceramics SC Materials Science GA 213JL UT WOS:000249663000025 ER PT J AU Manning, TA Tucker, DS Herren, KA Gregory, DA AF Manning, Timothy Andrew Tucker, Dennis S. Herren, Kenneth A. Gregory, Don A. TI Vacuum strength of two candidate glasses for a space observatory SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID STRESS-CORROSION; SILICATE GLASS; STATIC FATIGUE; FRACTURE AB The strengths of two-candidate glass types for use in a space observatory were measured. Samples of ultra-low expansion glass (ULE) and borosilicate (Pyrex) were tested in air and in vacuum at room temperature (20 degrees C) and in vacuum after being heated to 200 degrees C. Both glasses tested in vacuum showed a significant increase in strength over those tested in air. However, there was no statistical difference between the strength of samples tested in vacuum at room temperature and those tested in vacuum after heating to 200 degrees C. C1 Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Manning, TA (reprint author), Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. EM mannint@uah.edu NR 13 TC 0 Z9 0 U1 1 U2 2 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 2007 VL 90 IS 10 BP 3318 EP 3319 DI 10.1111/j.1551-2916.2007.01872.x PG 2 WC Materials Science, Ceramics SC Materials Science GA 213JL UT WOS:000249663000048 ER PT J AU Datta, A Nixon, M Chopra, I AF Datta, Anubhav Nixon, Mark Chopra, Inderjit TI Review of rotor loads prediction with the emergence of rotorcraft CFD SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT 31st European Rotorcraft Forum CY SEP 13-15, 2005 CL Florence, ITALY ID ESSENTIALLY NONOSCILLATORY SCHEMES; ROTARY-WING AEROELASTICITY; GEOMETRIC CONSERVATION LAW; COMPRESSIBLE DYNAMIC STALL; FINITE-DIFFERENCE SCHEMES; TRANSONIC POTENTIAL FLOW; LARGE-EDDY SIMULATIONS; TIME-DEPENDENT RANS; FREE-WAKE ANALYSIS; HELICOPTER ROTOR AB This paper reviews the state of the art in helicopter rotor loads prediction with the emergence of computational fluid dynamics (CFD) and computational structural dynamics (CSD) coupling. The focus is on steady level flight, where most of the current CFD/CSD analyses are being applied. The application of CFD to rotorcraft problems has evolved, over the period 1990-2005, as a viable means to improve the aerodynamic modeling used in rotorcraft comprehensive analyses (CA). It has the potential to meet the ultimate objective of a coupled rotor-fuselage analysis that can predict loads and vibration accurately at all critical flight conditions without semi-empirical inputs. The paper begins by identifying three critical level flight conditions. These are useful to isolate the key aerodynamic and structural dynamic mechanisms. It is followed by a review of the capabilities and limitations of current CFD analyses in representing the key aerodynamic mechanisms: three-dimensional airloads and wake, dynamic stall, unsteady transonic effects near the tip, and fuselage aerodynamic effects. The structural dynamic methods are then briefly reviewed. Finally, the recent rotorcraft CFD/CSD coupling methods are described and evaluated on the basis of their loads prediction capability. The emphasis is on the fundamental aeroelastic mechanisms which determine the critical rotor loads, and with which the accuracy and efficiency of all CFD/CSD coupled analyses should be assessed. C1 Univ Maryland, Alfred Gessow Rotorcraft Ctr, Dept Aerosp Engn, College Pk, MD 20742 USA. USA, Res Lab, Langley Res Ctr, Hampton, VA USA. RP Datta, A (reprint author), Univ Maryland, Alfred Gessow Rotorcraft Ctr, Dept Aerosp Engn, College Pk, MD 20742 USA. EM datta@umd.edu NR 238 TC 26 Z9 28 U1 0 U2 8 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 EI 2161-6027 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD OCT PY 2007 VL 52 IS 4 BP 287 EP 317 PG 31 WC Engineering, Aerospace SC Engineering GA 227GS UT WOS:000250645800001 ER PT J AU Lim, JW Nygaard, TA Strawn, R Potsdam, M AF Lim, Joon W. Nygaard, Tor A. Strawn, Roger Potsdam, Mark TI Blade-vortex interaction airloads prediction using coupled computational fluid and structural dynamics SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT 4th Vertical Lift Aircraft Design Conference CY JAN 18-20, 2006 CL San Francisco, CA SP Amer Helicopter Soc AB Correlations using a computational fluid dynamics code and rotorcraft computational structural dynamics code were made in order to calculate the helicopter rotor blade-vortex interaction airloads for descending forward flight. An iterative loosely coupled trim methodology was used to couple the computational fluid dynamics (OVERFLOW-2) and computational structural dynamics (CAMRAD 11) codes. The OVERFLOW-2 code used a high-fidelity Reynolds averaged Navier-Stokes, overset grid methodology. Several descending flight cases were used for correlation including UH-60A, HART I and HART II at an advance ratio of 0.15. The computational fluid dynamics grid resolution effect on airloads was also examined. Results were compared with flight data or wind tunnel data, and the computational fluid dynamics/computational structural dynamics coupled trim methodology was found to be stable, convergent, and robust with coupling of normal force, pitching moment, and chord force. In comparison with the measured data, the normal forces were well predicted, and the higher harmonic blade-vortex interaction loading predictions were excellent, especially for the HART II rotor. Overall, the use of a computational fluid dynamics code provides a noteworthy improvement over the lifting line aerodynamics used in the rotorcraft comprehensive analysis codes. C1 USA Res, Dev & Engn Command Ames Res Ctr, AMRDEC, Moffett Field, CA USA. Eloret Corp, Ames Res Ctr, Moffett Field, CA USA. RP Lim, JW (reprint author), USA Res, Dev & Engn Command Ames Res Ctr, AMRDEC, Moffett Field, CA USA. EM jwlim@mail.arc.nasa.gov NR 33 TC 4 Z9 4 U1 0 U2 3 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD OCT PY 2007 VL 52 IS 4 BP 318 EP 328 PG 11 WC Engineering, Aerospace SC Engineering GA 227GS UT WOS:000250645800002 ER PT J AU Desai, PN Lee, WJ Steltzner, A AF Desai, Prasun N. Lee, Wayne J. Steltzner, Adam TI Entry, descent, and landing scenario for the Mars exploration rover mission SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article ID RECONSTRUCTION AB In January 2004, the Mars Exploration Rover (MER) mission successfully landed two landers on the surface of Mars. Both landers delivered a rover to the surface using an entry, descent, and landing (EDL) scenario based on Mars Pathfinder heritage. However, the entry conditions and environments were different from that of Mars Pathfinder. Unique challenges were present due to the entry differences of a heavier entry mass, less dense atmosphere, and higher surface landing site altitude. These differences resulted in a higher terminal velocity and less time for performing all the EDL events as compared to Mars Pathfinder. As a result of these differences, modifications were made to the MER EDL systems to safely deliver the rovers to the surface of Mars. An overview of the design modifications made to the MER EDL system compared to MPF is described. C1 [Desai, Prasun N.] NASA, Langley Res Ctr, Atmospher Flight & Entry Syst Branch, Hampton, VA 23665 USA. [Lee, Wayne J.; Steltzner, Adam] Jet Propuls Lab, Pasadena, CA USA. RP Desai, PN (reprint author), NASA, Langley Res Ctr, Atmospher Flight & Entry Syst Branch, Hampton, VA 23665 USA. NR 7 TC 1 Z9 3 U1 2 U2 6 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD OCT-DEC PY 2007 VL 55 IS 4 BP 421 EP 430 PG 10 WC Engineering, Aerospace SC Engineering GA 281JY UT WOS:000254494100002 ER PT J AU Hinkelman, LM Evans, KF Clothiaux, EE Ackerman, TP Stackhouse, PW AF Hinkelman, Laura M. Evans, K. Franklin Clothiaux, Eugene E. Ackerman, Thomas P. Stackhouse, Paul W., Jr. TI The effect of cumulus cloud field anisotropy on domain-averaged solar fluxes and atmospheric heating rates SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INDEPENDENT PIXEL APPROXIMATION; RADIATIVE-TRANSFER; STRATOCUMULUS CLOUDS; ALBEDO; MODELS AB Cumulus clouds can become tilted or elongated in the presence of wind shear. Nevertheless, most studies of the interaction of cumulus clouds and radiation have assumed these clouds to be isotropic. This paper describes an investigation of the effect of fair-weather cumulus cloud field anisotropy on domain-averaged solar fluxes and atmospheric heating rate profiles. A stochastic field generation algorithm was used to produce 20 three-dimensional liquid water content fields based on the statistical properties of cloud scenes from a large eddy simulation. Progressively greater degrees of x-z plane tilting and horizontal stretching were imposed on each of these scenes, so that an ensemble of scenes was produced for each level of distortion. The resulting scenes were used as input to a three-dimensional Monte Carlo radiative transfer model. Domain-averaged transmission, reflection, and absorption of broadband solar radiation were computed for each scene along with the average heating rate profile. Both tilt and horizontal stretching were found to significantly affect calculated fluxes, with the amount and sign of flux differences depending strongly on sun position relative to cloud distortion geometry. The mechanisms by which anisotropy interacts with solar fluxes were investigated by comparisons to independent pixel approximation and tilted independent pixel approximation computations for the same scenes. Cumulus anisotropy was found to most strongly impact solar radiative transfer by changing the effective cloud fraction (i.e., the cloud fraction with respect to the solar beam direction). C1 Natl Inst Aerosp, Hampton, VA 23666 USA. Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Hinkelman, LM (reprint author), Natl Inst Aerosp, 100 Explorat Way,Rm 214, Hampton, VA 23666 USA. EM l.m.hinkelman@larc.nasa.gov RI Hinkelman, Laura/L-8964-2016 OI Hinkelman, Laura/0000-0001-6477-9648 NR 32 TC 12 Z9 14 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD OCT PY 2007 VL 64 IS 10 BP 3499 EP 3520 DI 10.1175/JAS4032.1 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 220QE UT WOS:000250171000007 ER PT J AU Nagano, H Ku, J AF Nagano, Hosei Ku, Jentung TI Capillary limit of a multiple-evaporator and multiple-condenser miniature loop heat pipe SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article; Proceedings Paper CT AIAA/ASME 9th Joint Thermophysics and Heat Transfer Conference CY JUN 05-08, 2006 CL San Francisco, CA SP AIAA, ASME AB An experimental investigation was conducted on the capillary limit of a miniature loop heat pipe with multiple evaporators and multiple condensers. Tests were conducted under various operating conditions: 1) beat load to one evaporator only; 2) even heat loads to both evaporators; 3) no temperature control of either compensation chamber; 4) controlling the temperature of one or both compensation chambers using thermoelectric devices; 5) placing the loop in a horizontal position with evaporators and compensation chambers on the same plane; and 6) placing the loop in a vertical position with evaporators above the compensation chambers. The physical processes that lead to evaporator deprime and the recovery from the deprime were examined. The effect of the gravity on the capillary limit and the compensation chamber temperature was also investigated. C1 Japan Aerosp Explorat Agcy, Dept Space Struct & Mat Engn, Space Sci Res Div, Kanagawa 2298510, Japan. RP Nagano, H (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 17 TC 5 Z9 6 U1 3 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD OCT-DEC PY 2007 VL 21 IS 4 BP 694 EP 701 DI 10.2514/1.26151 PG 8 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 222FQ UT WOS:000250281900004 ER PT J AU Lavelle, J AF Lavelle, Joe TI Wireless scanner assesses cracks, flaws in space shuttle tiles SO MATERIALS PERFORMANCE LA English DT News Item C1 NASA, Ames Res Ctr, Washington, DC 20546 USA. RP Lavelle, J (reprint author), NASA, Ames Res Ctr, Washington, DC 20546 USA. EM jlavelle@mail.arc.nasa.gov NR 0 TC 0 Z9 0 U1 2 U2 2 PU NATL ASSOC CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0094-1492 J9 MATER PERFORMANCE JI Mater. Perform. PD OCT PY 2007 VL 46 IS 10 BP 16 EP 16 PG 1 WC Materials Science, Characterization & Testing SC Materials Science GA 220HW UT WOS:000250148800006 ER PT J AU Lara, M Russell, RP Villac, B AF Lara, Martin Russell, Ryan P. Villac, Benjamin TI Fast estimation of stable regions in real models SO MECCANICA LA English DT Article DE hill problem; linear stability; chaoticity indicators; solar system ephemeris; spaceflight mechanics AB The combined use of periodic orbit computation and Fast Lyapunov Indicator Maps of systems with three degrees of freedom is proposed as a tool for estimating qualitative stability in corresponding real models. Application to spacecraft mission analysis reveals very useful in finding real orbits with very long term stability properties. C1 Real Observ Armada, ES-11110 San Fernando, Spain. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Irvine, Mech & Aerosp Engn, Irvine, CA 92697 USA. RP Lara, M (reprint author), Real Observ Armada, ES-11110 San Fernando, Spain. EM mlara@roa.es; ryan.russell@jpl.nasa.gov; bvillac@uci.edu RI Lara, Martin/L-6291-2014 OI Lara, Martin/0000-0001-6754-916X NR 4 TC 8 Z9 8 U1 0 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0025-6455 J9 MECCANICA JI Meccanica PD OCT PY 2007 VL 42 IS 5 BP 511 EP 515 DI 10.1007/s11012-007-9060-z PG 5 WC Mechanics SC Mechanics GA 217UB UT WOS:000249971700009 ER PT J AU Maimi, P Camanho, PP Mayugo, JA Davila, CG AF Maimi, P. Camanho, P. P. Mayugo, J. A. Davila, C. G. TI A continuum damage model for composite laminates: Part I - Constitutive model SO MECHANICS OF MATERIALS LA English DT Article DE fracture mechanics; continuum damage mechanics; composite materials ID PROGRESSIVE MATRIX CRACKING; ANISOTROPIC ELASTIC DEGRADATION; FAILURE; FORMULATION; PLY; MECHANICS AB A continuum damage model for the prediction of the onset and evolution of intralaminar failure mechanisms and the collapse of structures manufactured in fiber-reinforced plastic laminates is proposed. The failure mechanisms occurring in the longitudinal and transverse directions of a ply are represented by a set of scalar damage variables. Crack closure effects under load reversal are taken into account by using damage variables that are established as a function of the sign of the components of the stress tensor. Damage activation functions based on the LaRCO4 failure criteria are used to predict the different failure mechanisms occurring at the ply level. (C) 2007 Elsevier Ltd. All rights reserved. C1 Univ Girona, AMADEscola Politecn Super, Girona, Spain. Univ Porto, Fac Engn, DEMEGI, P-4200465 Oporto, Portugal. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Camanho, PP (reprint author), Univ Girona, AMADEscola Politecn Super, Girona, Spain. EM peamanho@fe.up.pt RI Mayugo, Joan Andreu/C-3772-2009; Davila, Carlos/D-8559-2011; Camanho, Pedro /E-1666-2011; AMADE Research Group, AMADE/B-6537-2014; Balanzat, Josep Costa/C-1017-2014; Maimi, Pere/C-3581-2009; OI Mayugo, Joan Andreu/0000-0001-8210-3529; AMADE Research Group, AMADE/0000-0002-5778-3291; Maimi, Pere/0000-0002-7350-1506; Camanho, Pedro/0000-0003-0363-5207 NR 45 TC 197 Z9 207 U1 3 U2 79 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6636 J9 MECH MATER JI Mech. Mater. PD OCT PY 2007 VL 39 IS 10 BP 897 EP 908 DI 10.1016/j.mechmat.2007.03.005 PG 12 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 192WC UT WOS:000248233100001 ER PT J AU Maimi, P Camanho, PP Mayugo, JA Davila, CG AF Maimi, P. Camanho, P. P. Mayugo, J. A. Davila, C. G. TI A continuum damage model for composite laminates: Part II - Computational implementation and validation SO MECHANICS OF MATERIALS LA English DT Article DE fracture mechanics; continuum damage mechanics; composite materials ID SHEAR AB This papers describes the computational implementation of a new damage model for laminated composites proposed in a previous paper. The objectivity of the numerical solution is assured by regularizing the energy dissipated at a material point by each failure mechanism. A viscous model is proposed to mitigate the convergence difficulties associated with strain softening constitutive models. To verify the accuracy of the approach, analyses of coupon specimens were performed, and the numerical predictions were compared with experimental data. (C) 2007 Elsevier Ltd. All rights reserved. C1 Univ Porto, Fac Engn, DEMEGI, P-4200465 Oporto, Portugal. Univ Girona, AMADE, Escola Politecn Super, Girona, Spain. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Camanho, PP (reprint author), Univ Porto, Fac Engn, DEMEGI, Rua Dr Roberto Frias, P-4200465 Oporto, Portugal. EM peamanho@fe.up.pt RI Mayugo, Joan Andreu/C-3772-2009; Davila, Carlos/D-8559-2011; Camanho, Pedro /E-1666-2011; AMADE Research Group, AMADE/B-6537-2014; Balanzat, Josep Costa/C-1017-2014; Maimi, Pere/C-3581-2009; OI Mayugo, Joan Andreu/0000-0001-8210-3529; AMADE Research Group, AMADE/0000-0002-5778-3291; Maimi, Pere/0000-0002-7350-1506; Camanho, Pedro/0000-0003-0363-5207 NR 17 TC 157 Z9 167 U1 1 U2 38 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6636 J9 MECH MATER JI Mech. Mater. PD OCT PY 2007 VL 39 IS 10 BP 909 EP 919 DI 10.1016/j.mechmat.2007.03.006 PG 11 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 192WC UT WOS:000248233100002 ER PT J AU Abercromby, AFJ Amonette, WE Layne, CS McFarlin, BK Hinman, MR Paloski, WH AF Abercromby, Andrew F. J. Amonette, William E. Layne, Charles S. McFarlin, Brian K. Hinman, Martha R. Paloski, William H. TI Vibration exposure and biodynamic responses during whole-body vibration training SO MEDICINE AND SCIENCE IN SPORTS AND EXERCISE LA English DT Article DE ISO 2631-1; estimated vibration dose value; mechanical impedance; head acceleration; risk ID BACK-PAIN; MUSCLE STRENGTH; EXERCISE; DENSITY; WOMEN; RISK; HIP AB Purpose: Excessive, chronic whole-body vibration (WBV) has a number of negative side effects on the human body, including disorders of the skeletal, digestive, reproductive, visual, and vestibular systems. Whole-body vibration training (WBVT) is intentional exposure to WBV to increase leg muscle strength, bone mineral density, health-related quality of life, and decrease back pain. The purpose of this study was to quantitatively evaluate vibration exposure and biodynamic responses during typical WBVT regimens. Methods: Healthy men and women (N = 16) were recruited to perform slow, unloaded squats during WBVT (30 Hz; 4 mm(p-p)), during which knee flexion angle (KA), mechanical impedance, head acceleration (Ha(rms)), and estimated vibration dose value (eVDV) were measured. WBVT was repeated using two forms of vibration: I) vertical forces to both feet simultaneously (VV), and 2) upward forces to only one foot at a time (RV). Results: Mechanical impedance varied inversely with KA during RV (effect size, eta(2)(p) : 0.668, P < 0.01) and VV (eta(2)(p): 0.533, P < 0.05). Ha(rms) varied with KA (eta(2)(p): 0.686, P < 0.01) and is greater during VV than during RV at all KA (P < 0.01). The effect of KA on Ha(rms) is different for RV and VV (eta(2)(p): 0.567, P < 0.05). The eVDV associated with typical RV and VV training regimens (30 Hz, 4 mm(p-p) 10 min.d(-1)) exceeds the recommended daily vibration exposure as defined by ISO 2631-1 (P < 0.01). Conclusions: ISO standards indicate that 10 min.d(-1) WBVT is potentially harmful to the human body; the risk of adverse health effects may be lower during RV than VV and at half-squats rather than full-squats or upright stance. More research is needed to explore the long-term health hazards of WBVT. C1 Wyle Labs Inc, Houston, TX 77058 USA. Univ Houston Clear Lake, Human Performance Lab, Houston, TX 77058 USA. Univ Houston, Lab Integrated Physiol, Houston, TX USA. Hardin Simmons Univ, Dept Phys Therapy, Abilene, TX 79601 USA. NASA, Human Adapt & Countermeasures Div, Houston, TX USA. RP Abercromby, AFJ (reprint author), Wyle Labs Inc, 1290 Hercules Dr, Houston, TX 77058 USA. EM andrew.abercromby-1@nasa.gov NR 24 TC 111 Z9 113 U1 2 U2 8 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0195-9131 J9 MED SCI SPORT EXER JI Med. Sci. Sports Exerc. PD OCT PY 2007 VL 39 IS 10 BP 1794 EP 1800 DI 10.1249/mss.0b013e3181238a0f PG 7 WC Sport Sciences SC Sport Sciences GA 217RD UT WOS:000249964100016 PM 17909407 ER PT J AU Ishigur, M Hir, T Tholen, DJ Sasak, S Ueda, Y Nimura, T Abe, M Clark, BE Yamamoto, A Yoshida, F Nakamura, R Hirata, N Miyamoto, H Yokota, Y Hashimot, T Kubota, T Nakamura, AM Gaskell, RW Sait, J AF Ishigur, Masateru Hir, Takahiro Tholen, David J. Sasak, Sho Ueda, Yuji Nimura, Tokuhiro Abe, Masanao Clark, Beth E. Yamamoto, Aya Yoshida, Furni Nakamura, Ryosuke Hirata, Naru Miyamoto, Hideaki Yokota, Yasuhiro Hashimot, Tatsuaki Kubota, Takashi Nakamura, Akiko M. Gaskell, Robert W. Sait, Jun TI Global mapping of the degree of space weathering on asteroid 25143 Itokawa by Hayabusa/AMICA observations SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID C MISSION TARGET; 25143 1998 SF36; MUSES-C; INFRARED OBSERVATIONS; COLOR VARIATIONS; ITOKAWA; EROS; DISTRIBUTIONS; REFLECTANCE; PHOTOMETRY AB We obtained color images of near-Earth asteroid 25143 Itokawa by the Hayabusa multiband imaging camera to characterize the regional color properties. Images were obtained for the whole disk from the gate position (GP) and home position (HP) at a spatial resolution of 0.8-3.7 m/ pixel. Whole-disk spectra are adjusted to the telescopic data obtained by the University of Hawai'i's 88-inch telescope using the Eight Color Asteroid Survey (ECAS) system. The disk-resolved measurements show large variations in the three visible channels. We present a map of an index related to the degree of space weathering, which has been newly developed based on laboratory measurements. We find large variations in the degree of space weathering on Itokawa. Fresh materials are observed in regions of steep slopes and craters, whereas mature materials are ubiquitously distributed. This result suggests that pristine ordinary chondrite-like materials have been exposed through weathered layers by excavation. By also examining close-up images obtained during touchdown rehearsal, we find that most rocks in Itokawa's rough terrains are weathered. Instead of a regolith blanket, the surface of this small asteroid is covered with weathered rocks and gravels. C1 [Ishigur, Masateru] Seoul Natl Univ, Dept Phys & Astron, Seoul 151742, South Korea. [Hir, Takahiro] Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. [Tholen, David J.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. [Sasak, Sho] Natl Astron Observ Japan, RISE Project, Mizusawa, Oshu 0230861, Japan. [Ueda, Yuji; Nimura, Tokuhiro] Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 113, Japan. [Nimura, Tokuhiro; Abe, Masanao; Yokota, Yasuhiro; Hashimot, Tatsuaki; Kubota, Takashi] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. [Clark, Beth E.] Ithaca Coll, Dept Phys, Ithaca, NY 14850 USA. [Yamamoto, Aya] Remote Sensing Technol Ctr Japan, Tokyo 1060032, Japan. [Yoshida, Furni] Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan. [Nakamura, Ryosuke] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058568, Japan. [Hirata, Naru] Univ Aizu, Dept Comp Software, Fukushima 9658580, Japan. [Miyamoto, Hideaki] Univ Tokyo, Univ Museum, Tokyo 1130033, Japan. [Nakamura, Akiko M.] Kobe Univ, Grad Sch Sci, Nada Ku, Kobe, Hyogo 6578501, Japan. [Gaskell, Robert W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Gaskell, Robert W.] PSI, Altadena, CA 91003 USA. [Sait, Jun] PASCO Corp, Satellite Business Div, Tokyo 1530043, Japan. RP Ishigur, M (reprint author), Seoul Natl Univ, Dept Phys & Astron, Seoul 151742, South Korea. EM ishiguro@astro.snu.ac.kr RI Miyamoto, Hideaki/B-9666-2008; Miyamoto, Hideaki/E-3381-2012 NR 43 TC 21 Z9 21 U1 0 U2 3 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD OCT PY 2007 VL 42 IS 10 BP 1791 EP 1800 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 253PI UT WOS:000252529700008 ER PT J AU Domingue, D Vilas, F AF Domingue, Deborah Vilas, Faith TI Local topographic effects on photometry and reflectance spectra of planetary surfaces: An example based on lunar photometry SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID COHERENT BACKSCATTER; MOON; SCATTERING; SPECTROSCOPY; CLEMENTINE; MERCURY; MODELS; TEMPERATURE; MAGNITUDES; TERRAINS AB The photometric properties of the average lunar surface are characterized using Hapke's equations and whole disk observations ranging from 0.36 to 1.06 mu m. Synthetic spectra across a crater topographic profile are created using the modeling results. The synthetic spectra are examined for spectral variations created by changes in lighting conditions induced by the topography. Changes above the modeling uncertainties are seen in both spectral slope and band depths, though the most pronounced change is in band depth. The data have insufficient spectral resolution to determine if there are any changes in band center due to photometric effects. No additional absorption features are introduced by the photometry. These results have serious implications on the interpretation of spectral observations in terms of abundance estimates and alteration processes as a function of location and association with geologic features. C1 [Domingue, Deborah] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. [Domingue, Deborah] NASA, Planetary Astron Grp, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Domingue, D (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. EM deborah.domingue@jhuapl.edu NR 40 TC 11 Z9 12 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD OCT PY 2007 VL 42 IS 10 BP 1801 EP 1816 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 253PI UT WOS:000252529700009 ER PT J AU Gruener, JE Ming, DW Galindo, C Henderson, KE Golden, DC AF Gruener, J. E. Ming, D. W. Galindo, C., Jr. Henderson, K. E. Golden, D. C. TI Plant productivity and characterization of zeoponic substrates after three successive crops of radish (Raphanus sativus L.) SO MICROPOROUS AND MESOPOROUS MATERIALS LA English DT Article; Proceedings Paper CT 7th International Conference on Occurrence Properties and Utilization of Natural Zeolites CY JUL 16-21, 2006 CL New Mexico Inst Mining & Technol, Socorro, NM SP Int Nat Zeolite Assoc HO New Mexico Inst Mining & Technol DE zeolite; zeoponics; clinoptilolite; apatite; radish ID CONTAINING SYNTHETIC HYDROXYAPATITES; PHOSPHATE ROCK; CATION-EXCHANGE; CLINOPTILOLITE; MANGANESE; GROWTH; IRON; WHEAT; PHOSPHORUS; SOLUBILITY AB The National Aeronautics and Space Administration (NASA) has developed a zeolite-based synthetic substrate, termed zeoponics. The zeoponic substrate (consisting of NH4- and K-exchanged clinoptilolite, synthetic apatite, and dolomite) provides all of the plant-essential nutrients through mineral dissolution and ion exchange, with only the addition of water. Previous studies have shown high productivity of wheat in zeoponic substrates; however, no experiments have been conducted on other crops. The objective of this study was to determine the productivity and nutrient uptake of radish (Raphanus sativus L.) grown in zeoponic substrates with three successive crops in the same substrate. Radish was chosen because of its sensitivities to NH4+. Average fresh weights of edible roots were similar for radish grown in zeoponic substrates watered with deionized H2O (10.97 g/plant) and in potting mix control substrate irrigated with nutrient solution (10.92 g/plant). Average fresh weight production of edible roots for radish grown in same zeoponic substrate increased in yield over time with the lowest yield in the first crop (7.10 g/plant) and highest in the third crop (13.90 g/plant). The Ca plant tissue levels in radishes (1.8-2.9 wt%) grown in zeoponic substrates are lower than the suggested sufficient range of 3.0-4.5 wt% Ca; however, the Ca level is highest (2.9 wt%) in radishes grown in the third crop in the same zeoponic substrates. The higher radish yield in the third crop was attributed to a reduction in an NH4-induced Ca deficiency that has been previously described for wheat grown in zeoponic substrates. The P levels in plant tissues of radish grown in the zeoponic substrates ranged from 0.94 to 1.15 wt%; which is slightly higher than the sufficient levels of 0.3-0.7 wt%. With the exception of Ca and P, other macronutrient and micronutrient levels in radish grown in zeoponic substrates were well within the recommended sufficient ranges. After three successive crops of radish growth, the zeoponic substrates had 52% of the original NH4-N and 78% of the original K remaining on zeolite exchange sites. Zeoponic substrates are capable of long-term productivity of radishes. (c) 2007 Elsevier Inc. All rights reserved. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. MEI Technol, Houston, TX 77058 USA. Hamilton Sundstrand, ESCG, Houston, TX 77258 USA. RP Ming, DW (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code KX, Houston, TX 77058 USA. EM douglas.w.ming@nasa.gov NR 27 TC 5 Z9 5 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-1811 J9 MICROPOR MESOPOR MAT JI Microporous Mesoporous Mat. PD OCT 1 PY 2007 VL 105 IS 3 BP 279 EP 284 DI 10.1016/j.micromeso.2007.04.016 PG 6 WC Chemistry, Applied; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 221TV UT WOS:000250251100010 ER PT J AU Vanhandel, M Kateb, B Zhang, L Bronikowski, M Monahara, H Badie, B AF Vanhandel, Michelle Kateb, Babak Zhang, Leying Bronikowski, Michael Monahara, Harish Badie, Behnam TI Characterization of carbon nanotube internalization in a murine glioma model SO NEURO-ONCOLOGY LA English DT Meeting Abstract CT 12th Annual Meeting of the Society-for-Neuro-Oncology CY NOV 15-18, 2007 CL Dallas, TX SP Soc Neuro Oncol C1 [Bronikowski, Michael; Monahara, Harish] CALTECH, Jet Prop Lab, Pasadena, CA USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU DUKE UNIV PRESS PI DURHAM PA 905 W MAIN ST, STE 18-B, DURHAM, NC 27701 USA SN 1522-8517 J9 NEURO-ONCOLOGY JI Neuro-Oncology PD OCT PY 2007 VL 9 IS 4 BP 502 EP 502 PG 1 WC Oncology; Clinical Neurology SC Oncology; Neurosciences & Neurology GA 218EP UT WOS:000249999100142 ER PT J AU Fuglesang, C AF Fuglesang, C. TI Using the human eye to image space radiation or the history and status of the light flash phenomena SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Conference on Imaging Techniques in Subatomic Physics, Astrophysics, Medicine, Biology and Industry CY JUN 27-30, 2006 CL Stockholm, SWEDEN SP Noble Inst Phys, Secta Mamea DE spaceflight; light flash; phosphenes; radiation; particles ID VISUAL SENSATIONS; CERENKOV RADIATION; NITROGEN NUCLEI; ASTRONAUTS; RAY; STATION; IONS; RESPONSES; PROJECT; RETINA AB About 80% of people who travel in space experience sudden phosphenes, commonly called light flashes (LF). Although the detailed physiological process is still not known, the LFs are caused by particles in the cosmic radiation field. Indeed, by counting LFs one can even make a crude image of the radiation environment around the Earth. Studies on the space station Mir with the SilEye experiment correlated LFs with charged particles traversing the eye. It was found that a nucleus in the radiation environment has roughly a 1% probability of causing a light flash, whereas the proton's probability is almost three orders of magnitude less. As a function of linear energy transfer (LET), the probability increased with ionization above 10 keV/mu m, reaching about 5% at 50 keV/mu m. The investigations are continuing on the International Space Station (ISS) with the Alteino/SileEye-3 detector, which is also a precursor to the large Anomalous Long Term Effects on Astronauts (ALTEA) facility. These detectors are also measuring-imaging-the radiation environment inside the ISS, which will be compared to Geant4 simulations from the DESIRE project. To further the understanding of the LF phenomena, a survey among current NASA and ESA astronauts was recently conducted. The LFs are predominantly noticed before sleep and some respondents even thought it disturbed their sleep. The LFs appear white, have elongated shapes, and most interestingly, often come with a sense of motion. Comparing the shapes quoted from space observations with ground experiments done by researchers in the 1970s, it seems likely that some 5-10% of the LFs in space are due to Cherenkov light in the eye. However, the majority is most likely caused by some direct interaction in the retina. (c) 2007 Elsevier B.V. All rights reserved. C1 Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. ESA, European Astronaut Ctr, Cologne, Germany. Royal Inst Technol, Stockholm, Sweden. RP Fuglesang, C (reprint author), Lyndon B Johnson Space Ctr, Mailcode CB,2101 NASA Parkway, Houston, TX 77058 USA. EM Christer.fuglesang@esa.int NR 35 TC 7 Z9 7 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 1 PY 2007 VL 580 IS 2 BP 861 EP 865 DI 10.1016/j.nima.2007.06.095 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 219ZZ UT WOS:000250128000008 ER PT J AU Tai, H AF Tai, Hsiang TI In search of multipeaked reflective spectrum with optic fiber Bragg grating sensor for dynamic strain measurement SO OPTICAL ENGINEERING LA English DT Article DE fiber optic Bragg grating; nonuniform strain; dynamic vibration; transverse; reflective spectrum AB In a typical optic fiber Bragg grating (FBG) strain measurement, unless made in an ideal static laboratory environment, the presence of vibration or often disturbance always exists, which often creates spurious multiple peaks in the reflected spectrum, resulting in a nonunique determination of strain value. We attempt to investigate the origin of this phenomenon by physical arguments and simple numerical simulation. We postulate that the fiber gratings execute small-amplitude transverse, vibrations changing the optical path in which the reflected light traverses slightly and nonuniformly. Ultimately, this causes the multipeak reflected spectrum. (C) 2007 Society of Photo-Optical Instrumentation Engineers. C1 [Tai, Hsiang] NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Tai, H (reprint author), NASA, Langley Res Ctr, 3B E Taylor St, Hampton, VA 23665 USA. NR 7 TC 1 Z9 1 U1 0 U2 2 PU SPIE-SOC PHOTOPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD OCT PY 2007 VL 46 IS 10 AR 104401 DI 10.1117/1.2799181 PG 5 WC Optics SC Optics GA 239WO UT WOS:000251549200019 ER PT J AU Mishchenko, MI Liu, L Hovenier, JW AF Mishchenko, Michael I. Liu, Li Hovenier, Joop W. TI Effects of absorption on multiple scattering by random particulate media: exact results SO OPTICS EXPRESS LA English DT Article ID WEAK-LOCALIZATION AB We employ the numerically exact superposition T-matrix method to perform extensive computations of electromagnetic scattering by a volume of discrete random medium densely filled with increasingly absorbing as well as non-absorbing particles. Our numerical data demonstrate that increasing absorption diminishes and nearly extinguishes certain optical effects such as depolarization and coherent backscattering and increases the angular width of coherent backscattering patterns. This result corroborates the multiple-scattering origin of such effects and further demonstrates the heuristic value of the concept of multiple scattering even in application to densely packed particulate media. (C) 2007 Optical Society of America. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM mmishchenko@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 NR 15 TC 11 Z9 11 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD OCT 1 PY 2007 VL 15 IS 20 BP 13182 EP 13187 DI 10.1364/OE.15.013182 PG 6 WC Optics SC Optics GA 218HN UT WOS:000250006700063 PM 19550586 ER PT J AU Mishchenko, MI AF Mishchenko, Michael I. TI Electromagnetic scattering by a fixed finite object embedded in an absorbing medium SO OPTICS EXPRESS LA English DT Article ID LIGHT-SCATTERING; SPHERICAL-PARTICLES; EXTINCTION; EFFICIENCY; FIELD AB This paper presents a general and systematic analysis of the problem of electromagnetic scattering by an arbitrary finite fixed object embedded in an absorbing, homogeneous, isotropic, and unbounded medium. The volume integral equation is used to derive generalized formulas of the far-field approximation. The latter serve to introduce direct optical observables such as the phase and extinction matrices. The differences between the generalized equations and their counterparts describing electromagnetic scattering by an object embedded in a non-absorbing medium are discussed. (C) 2007 Optical Society of America. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM mmishchenko@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 NR 29 TC 21 Z9 21 U1 2 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD OCT 1 PY 2007 VL 15 IS 20 BP 13188 EP 13202 DI 10.1364/OE.15.013188 PG 15 WC Optics SC Optics GA 218HN UT WOS:000250006700064 PM 19550587 ER PT J AU Huang, EM Mynatt, ED Trimble, JP AF Huang, Elaine M. Mynatt, Elizabeth D. Trimble, Jay P. TI When design just isn't enough: the unanticipated challenges of the real world for large collaborative displays SO PERSONAL AND UBIQUITOUS COMPUTING LA English DT Article DE large displays; multi-display environments; CSCW; field studies; evaluation AB Large interactive displays for supporting workgroup collaboration comprise a growing area of ubiquitous computing research and many such systems have been designed and deployed in laboratory studies and research settings. Such displays face difficulties in real-world deployments, as they are often supplemental technologies as opposed to primary tools for work activities. In this work, we investigate the integration and uptake of the NASA MERBoards, shared interactive displays that were deployed to support science tasks in the Mars Exploration Rover (MER) missions. We examine the hurdles to adoption imposed specifically by the real-world circumstances of the deployment that were external to the design of the system, and explain how these concerns apply to the general deployment of shared ubicomp technologies in the real world. C1 Motorola Labs, Schaumburg, IL USA. Rhein Westfal TH Aachen, Aachen, Germany. Georgia Inst Technol, Atlanta, GA 30332 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Huang, EM (reprint author), Motorola Labs, Schaumburg, IL USA. EM elaine.m.huang@motorola.com; mynatt@cc.gatech.edu; jay.p.trimble@nasa.gov NR 16 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER LONDON LTD PI LONDON PA 236 GRAYS INN RD, 6TH FLOOR, LONDON WC1X 8HL, ENGLAND SN 1617-4909 J9 PERS UBIQUIT COMPUT JI Pers. Ubiquitous Comput. PD OCT PY 2007 VL 11 IS 7 BP 537 EP 547 DI 10.1007/s00779-006-0114-3 PG 11 WC Computer Science, Information Systems; Telecommunications SC Computer Science; Telecommunications GA 217AI UT WOS:000249920200004 ER PT J AU Galeazzi, M Liu, D McCammon, D Rocks, LE Sanders, WT Smith, B Tan, P Vaillancourt, JE Boyce, KR Brekosky, RP Gygax, JD Kelley, RL Kilbourne, CA Porter, FS Stahle, CM Szymkowiak, AE AF Galeazzi, M. Liu, D. McCammon, D. Rocks, L. E. Sanders, W. T. Smith, B. Tan, P. Vaillancourt, J. E. Boyce, K. R. Brekosky, R. P. Gygax, J. D. Kelley, R. L. Kilbourne, C. A. Porter, F. S. Stahle, C. M. Szymkowiak, A. E. TI Hot-electron effects in strongly localized doped silicon at low temperature SO PHYSICAL REVIEW B LA English DT Article ID METAL-INSULATOR-TRANSITION; HOPPING CONDUCTION; SEMICONDUCTOR THERMISTORS; BOLOMETER; MICROCALORIMETER; SENSITIVITY AB The electrical conductivity in doped semiconductors in the strongly localized variable range hopping regime is currently explained as phonon-assisted electron hopping. While investigating the non-Ohmic behavior of doped silicon at temperatures of 0.05-1 K, we found strong evidence for the existence of separate temperatures for the electron and phonon systems analogous to the hot-electron effect in metals. This behavior cannot easily be explained by phonon-assisted hopping and seems to favor instead a direct electron-electron interaction at low temperature. A hot-electron model makes definite predictions for the dependence of the electrical conductivity on the bias power, the frequency dependence of the resistance nonlinearities, and for an additional noise term. We have made a systematic investigation of these quantities, and find all of them in good agreement with the model predictions over a wide range of parameters. C1 [Galeazzi, M.; Liu, D.; McCammon, D.; Rocks, L. E.; Sanders, W. T.; Smith, B.; Tan, P.; Vaillancourt, J. E.] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. [Boyce, K. R.; Brekosky, R. P.; Gygax, J. D.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Stahle, C. M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Szymkowiak, A. E.] Yale Univ, Dept Phys, New Haven, CT 06520 USA. RP Galeazzi, M (reprint author), Univ Miami, Dept Phys, POB 248046, Coral Gables, FL 33124 USA. EM galeazzi@physics.miami.edu RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012; OI Porter, Frederick/0000-0002-6374-1119; Vaillancourt, John/0000-0001-8916-1828 NR 25 TC 6 Z9 6 U1 0 U2 1 PU AMER 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 OCT PY 2007 VL 76 IS 15 AR 155207 DI 10.1103/PhysRevB.76.155207 PG 6 WC Physics, Condensed Matter SC Physics GA 226WY UT WOS:000250620400067 ER PT J AU Wei, CY AF Wei, Chenyu TI Structural phase transition of alkane molecules in nanotube composites SO PHYSICAL REVIEW B LA English DT Article ID WALLED CARBON NANOTUBES; SHORT-RANGE ORDER; POLYMER COMPOSITES; MECHANICAL-PROPERTIES; DYNAMICS SIMULATION; AMORPHOUS POLYMER; SINGLE; CRYSTALLIZATION; DNA; REINFORCEMENT AB The structural phase transition and crystallization process of alkane molecules in carbon nanotube (CNT) composites are studied through molecular dynamics simulations. An isotropic-to-nematic transition with molecules aligned with embedded nanotubes is found. Further smectic transition of the alkane molecules is found with small radius armchaired CNT (5, 5) as a nucleation site, where molecules form lamellar layers along the nanotube axis and have two-dimensional structure ordering in planes perpendicular to the tube axis, in analogy to a crystalline polymer. While the translational diffusions are limited in the smectic phase, the molecules have rotation freedom along its long axis with small energy barriers similar to 1-2k(B)T (T=300 K) for decane molecules studied here. The molecule crystallization is found to strongly dependent on CNT chirality, where a lack of two-dimensional ordering of molecules around a similar radius zigzag CNT (10, 0) is due to diverse molecule assembly domains with tilted wrapping angles at the interface, controlled by the interactions with the substrate nanotube lattice. The influence of strength and nature of the interfacial interactions between molecules and nanotubes is also studied. The results in this study would be useful and important for the understanding of structural phases in hybrid polymer materials and for the designs of nanotube based high performance composites. C1 [Wei, Chenyu] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Wei, CY (reprint author), NASA, Ames Res Ctr, MS 229-1, Moffett Field, CA 94035 USA. EM cwei@mail.arc.nasa.gov NR 49 TC 21 Z9 21 U1 3 U2 12 PU AMER 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 OCT PY 2007 VL 76 IS 13 AR 134104 DI 10.1103/PhysRevB.76.134104 PG 10 WC Physics, Condensed Matter SC Physics GA 226WS UT WOS:000250619800033 ER PT J AU Abbott, B Abbott, R Adhikari, R Agresti, J Ajith, P Allen, B Amin, R Anderson, SB Anderson, WG Arain, M Araya, M Armandula, H Ashley, M Aston, S Aufmuth, P Aulbert, C Babak, S Ballmer, S Bantilan, H Barish, BC Barker, C Barker, D Barr, B Barriga, P Barton, MA Bayer, K Belczynski, K Betzwieser, J Beyersdorf, PT Bhawal, B Bilenko, IA Billingsley, G Biswas, R Black, E Blackburn, K Blackburn, L Blair, D Bland, B Bogenstahl, J Bogue, L Bork, R Boschi, V Bose, S Brady, PR Braginsky, VB Brau, JE Brinkmann, M Brooks, A Brown, DA Bullington, A Bunkowski, A Buonanno, A Burmeister, O Busby, D Byer, RL Cadonati, L Cagnoli, G Camp, JB Cannizzo, J Cannon, K Cantley, CA Cao, J Cardenas, L Casey, MM Castaldi, G Cepeda, C Chalkey, E Charlton, P Chatterji, S Chelkowski, S Chen, Y Chiadini, F Chin, D Chin, E Chow, J Christensen, N Clark, J Cochrane, P Cokelaer, T Colacino, CN Coldwell, R Conte, R Cook, D Corbitt, T Coward, D Coyne, D Creighton, JDE Creighton, TD Croce, RP Crooks, DRM Cruise, AM Cumming, A Dalrymple, J D'Ambrosio, E Danzmann, K Davies, G Debra, D Degallaix, J Degree, M Demma, T Dergachev, V Desai, S DeSalvo, R Dhurandhar, S Diaz, M Dickson, J Di Credico, A Diederichs, G Dietz, A Doomes, EE Drever, RWP Dumas, JC Dupuis, RJ Dwyer, JG Ehrens, P Espinoza, E Etzel, T Evans, M Evans, T Fairhurst, S Fan, Y Fazi, D Fejer, MM Finn, LS Fiumara, V Fotopoulos, N Franzen, A Franzen, KY Freise, A Frey, R Fricke, T Fritschel, P Frolov, VV Fyffe, M Galdi, V Garofoli, J Gholami, I Giaime, JA Giampanis, S Giardina, KD Goda, K Goetz, E Goggin, LM Gonzalez, G Gossler, S Grant, A Gras, S Gray, C Gray, M Greenhalgh, J Gretarsson, AM Grosso, R Grote, H Grunewald, S Guenther, M Gustafson, R Hage, B Hammer, D Hanna, C Hanson, J Harms, J Harry, G Harstad, E Hayler, T Heefner, J Heng, IS Heptonstall, A Heurs, M Hewitson, M Hild, S Hirose, E Hoak, D Hosken, D Hough, J Howell, E Hoyland, D Huttner, SH Ingram, D Innerhofer, E Ito, M Itoh, Y Ivanov, A Jackrel, D Johnson, B Johnson, WW Jones, DI Jones, G Jones, R Ju, L Kalmus, P Kalogera, V Kasprzyk, D Katsavounidis, E Kawabe, K Kawamura, S Kawazoe, F Kells, W Keppel, DG Khalili, FY Kim, C King, P Kissel, JS Klimenko, S Kokeyama, K Kondrashov, V Kopparapu, RK Kozak, D Krishnan, B Kwee, P Lam, PK Landry, M Lantz, B Lazzarini, A Lee, B Lei, M Leiner, J Leonhardt, V Leonor, I Libbrecht, K Lindquist, P Lockerbie, NA Longo, M Lormand, M Lubinski, M Luck, H Machenschalk, B MacInnis, M Mageswaran, M Mailand, K Malec, M Mandic, V Marano, S Marka, S Markowitz, J Maros, E Martin, I Marx, JN Mason, K Matone, L Matta, V Mavalvala, N McCarthy, R McClelland, DE McGuire, SC McHugh, M McKenzie, K McNabb, JWC McWilliams, S Meier, T Melissinos, A Mendell, G Mercer, RA Meshkov, S Messaritaki, E Messenger, CJ Meyers, D Mikhailov, E Mitra, S Mitrofanov, VP Mitselmakher, G Mittleman, R Miyakawa, O Mohanty, S Moreno, G Mossavi, K MowLowry, C Moylan, A Mudge, D Mueller, G Mukherjee, S Muller-Ebhardt, H Munch, J Murray, P Myers, E Myers, J Newton, G Nishizawa, A Numata, K O'Reilly, B O'Shaughnessy, R Ottaway, DJ Overmier, H Owen, BJ Pan, Y Papa, MA Parameshwaraiah, V Patel, P Pedraza, M Penn, S Pierro, V Pinto, IM Pitkin, M Pletsch, H Plissi, MV Postiglione, F Prix, R Quetschke, V Raab, F Rabeling, D Radkins, H Rahkola, R Rainer, N Rakhmanov, M Rawlins, K Ray-Majumder, S Re, V Rehbein, H Reid, S Reitze, DH Ribichini, L Riesen, R Riles, K Rivera, B Robertson, NA Robinson, C Robinson, EL Roddy, S Rodriguez, A Rogan, AM Rollins, J Romano, JD Romie, J Route, R Rowan, S Rudiger, A Ruet, L Russell, P Ryan, K Sakata, S Samidi, M De la Jordana, LS Sandberg, V Saraf, S Sarin, P Sathyaprakash, BS Sato, S Saulson, PR Savage, R Savov, P Schediwy, S Schilling, R Schnabel, R Schofield, R Schutz, BF Schwinberg, P Scott, SM Searle, AC Sears, B Seifert, F Sellers, D Sengupta, AS Shawhan, P Shoemaker, DH Sibley, A Sidles, JA Siemens, X Sigg, D Sinha, S Sintes, AM Slagmolen, BJJ Slutsky, J Smith, JR Smith, MR Somiya, K Strain, KA Strom, DM Stuver, A Summerscales, TZ Sun, KX Sung, M Sutton, PJ Takahashi, H Tanner, DB Tarallo, M Taylor, R Taylor, R Thacker, J Thorne, KA Thorne, KS Thuring, A Tokmakov, KV Torres, C Torrie, C Traylor, G Trias, M Tyler, W Ugolini, D Ungarelli, C Urbanek, K Vahlbruch, H Vallisneri, M Van den Broeck, C Varvella, M Sannibale, V Vass, S Vecchio, A Veitch, J Veitch, P Villar, A Vorvick, C Vyachanin, SP Waldman, SJ Wallace, L Ward, H Ward, R Watts, K Webber, D Weidner, A Weinert, M Weinstein, A Weiss, R Wen, S Wette, K Whelan, JT Whitbeck, DM Whitcomb, SE Whiting, BF Wilkinson, C Willems, PA Williams, L Willke, B Wilmut, I Winkler, W Wipf, CC Wise, S Wiseman, AG Woan, G Woods, D Wooley, R Worden, J Wu, W Yakushin, I Yamamoto, H Yan, Z Yoshida, S Yunes, N Zanolin, M Zhang, J Zhang, L Zhao, C Zotov, N Zucker, M Muhlen, HZ Zweizig, J AF Abbott, B. Abbott, R. Adhikari, R. Agresti, J. Ajith, P. Allen, B. Amin, R. Anderson, S. B. Anderson, W. G. Arain, M. Araya, M. Armandula, H. Ashley, M. Aston, S. Aufmuth, P. Aulbert, C. Babak, S. Ballmer, S. Bantilan, H. Barish, B. C. Barker, C. Barker, D. Barr, B. Barriga, P. Barton, M. A. Bayer, K. Belczynski, K. Betzwieser, J. Beyersdorf, P. T. Bhawal, B. Bilenko, I. A. Billingsley, G. Biswas, R. Black, E. Blackburn, K. Blackburn, L. Blair, D. Bland, B. Bogenstahl, J. Bogue, L. Bork, R. Boschi, V. Bose, S. Brady, P. R. Braginsky, V. B. Brau, J. E. Brinkmann, M. Brooks, A. Brown, D. A. Bullington, A. Bunkowski, A. Buonanno, A. Burmeister, O. Busby, D. Byer, R. L. Cadonati, L. Cagnoli, G. Camp, J. B. Cannizzo, J. Cannon, K. Cantley, C. A. Cao, J. Cardenas, L. Casey, M. M. Castaldi, G. Cepeda, C. Chalkey, E. Charlton, P. Chatterji, S. Chelkowski, S. Chen, Y. Chiadini, F. Chin, D. Chin, E. Chow, J. Christensen, N. Clark, J. Cochrane, P. Cokelaer, T. Colacino, C. N. Coldwell, R. Conte, R. Cook, D. Corbitt, T. Coward, D. Coyne, D. Creighton, J. D. E. Creighton, T. D. Croce, R. P. Crooks, D. R. M. Cruise, A. M. Cumming, A. Dalrymple, J. D'Ambrosio, E. Danzmann, K. Davies, G. Debra, D. Degallaix, J. Degree, M. Demma, T. Dergachev, V. Desai, S. DeSalvo, R. Dhurandhar, S. Diaz, M. Dickson, J. Di Credico, A. Diederichs, G. Dietz, A. Doomes, E. E. Drever, R. W. P. Dumas, J. -C. Dupuis, R. J. Dwyer, J. G. Ehrens, P. Espinoza, E. Etzel, T. Evans, M. Evans, T. Fairhurst, S. Fan, Y. Fazi, D. Fejer, M. M. Finn, L. S. Fiumara, V. Fotopoulos, N. Franzen, A. Franzen, K. Y. Freise, A. Frey, R. Fricke, T. Fritschel, P. Frolov, V. V. Fyffe, M. Galdi, V. Garofoli, J. Gholami, I. Giaime, J. A. Giampanis, S. Giardina, K. D. Goda, K. Goetz, E. Goggin, L. M. Gonzalez, G. Gossler, S. Grant, A. Gras, S. Gray, C. Gray, M. Greenhalgh, J. Gretarsson, A. M. Grosso, R. Grote, H. Grunewald, S. Guenther, M. Gustafson, R. Hage, B. Hammer, D. Hanna, C. Hanson, J. Harms, J. Harry, G. Harstad, E. Hayler, T. Heefner, J. Heng, I. S. Heptonstall, A. Heurs, M. Hewitson, M. Hild, S. Hirose, E. Hoak, D. Hosken, D. Hough, J. Howell, E. Hoyland, D. Huttner, S. H. Ingram, D. Innerhofer, E. Ito, M. Itoh, Y. Ivanov, A. Jackrel, D. Johnson, B. Johnson, W. W. Jones, D. I. Jones, G. Jones, R. Ju, L. Kalmus, P. Kalogera, V. Kasprzyk, D. Katsavounidis, E. Kawabe, K. Kawamura, S. Kawazoe, F. Kells, W. Keppel, D. G. Khalili, F. Ya. Kim, C. King, P. Kissel, J. S. Klimenko, S. Kokeyama, K. Kondrashov, V. Kopparapu, R. K. Kozak, D. Krishnan, B. Kwee, P. Lam, P. K. Landry, M. Lantz, B. Lazzarini, A. Lee, B. Lei, M. Leiner, J. Leonhardt, V. Leonor, I. Libbrecht, K. Lindquist, P. Lockerbie, N. A. Longo, M. Lormand, M. Lubinski, M. Luck, H. Machenschalk, B. MacInnis, M. Mageswaran, M. Mailand, K. Malec, M. Mandic, V. Marano, S. Marka, S. Markowitz, J. Maros, E. Martin, I. Marx, J. N. Mason, K. Matone, L. Matta, V. Mavalvala, N. McCarthy, R. McClelland, D. E. McGuire, S. C. McHugh, M. McKenzie, K. McNabb, J. W. C. McWilliams, S. Meier, T. Melissinos, A. Mendell, G. Mercer, R. A. Meshkov, S. Messaritaki, E. Messenger, C. J. Meyers, D. Mikhailov, E. Mitra, S. Mitrofanov, V. P. Mitselmakher, G. Mittleman, R. Miyakawa, O. Mohanty, S. Moreno, G. Mossavi, K. MowLowry, C. Moylan, A. Mudge, D. Mueller, G. Mukherjee, S. Mueller-Ebhardt, H. Munch, J. Murray, P. Myers, E. Myers, J. Newton, G. Nishizawa, A. Numata, K. O'Reilly, B. O'Shaughnessy, R. Ottaway, D. J. Overmier, H. Owen, B. J. Pan, Y. Papa, M. A. Parameshwaraiah, V. Patel, P. Pedraza, M. Penn, S. Pierro, V. Pinto, I. M. Pitkin, M. Pletsch, H. Plissi, M. V. Postiglione, F. Prix, R. Quetschke, V. Raab, F. Rabeling, D. Radkins, H. Rahkola, R. Rainer, N. Rakhmanov, M. Rawlins, K. Ray-Majumder, S. Re, V. Rehbein, H. Reid, S. Reitze, D. H. Ribichini, L. Riesen, R. Riles, K. Rivera, B. Robertson, N. A. Robinson, C. Robinson, E. L. Roddy, S. Rodriguez, A. Rogan, A. M. Rollins, J. Romano, J. D. Romie, J. Route, R. Rowan, S. Ruediger, A. Ruet, L. Russell, P. Ryan, K. Sakata, S. Samidi, M. De la Jordana, L. Sancho Sandberg, V. Saraf, S. Sarin, P. Sathyaprakash, B. S. Sato, S. Saulson, P. R. Savage, R. Savov, P. Schediwy, S. Schilling, R. Schnabel, R. Schofield, R. Schutz, B. F. Schwinberg, P. Scott, S. M. Searle, A. C. Sears, B. Seifert, F. Sellers, D. Sengupta, A. S. Shawhan, P. Shoemaker, D. H. Sibley, A. Sidles, J. A. Siemens, X. Sigg, D. Sinha, S. Sintes, A. M. Slagmolen, B. J. J. Slutsky, J. Smith, J. R. Smith, M. R. Somiya, K. Strain, K. A. Strom, D. M. Stuver, A. Summerscales, T. Z. Sun, K. -X. Sung, M. Sutton, P. J. Takahashi, H. Tanner, D. B. Tarallo, M. Taylor, R. Taylor, R. Thacker, J. Thorne, K. A. Thorne, K. S. Thuering, A. Tokmakov, K. V. Torres, C. Torrie, C. Traylor, G. Trias, M. Tyler, W. Ugolini, D. Ungarelli, C. Urbanek, K. Vahlbruch, H. Vallisneri, M. Van den Broeck, C. Varvella, M. Sannibale, V. Vass, S. Vecchio, A. Veitch, J. Veitch, P. Villar, A. Vorvick, C. Vyachanin, S. P. Waldman, S. J. Wallace, L. Ward, H. Ward, R. Watts, K. Webber, D. Weidner, A. Weinert, M. Weinstein, A. Weiss, R. Wen, S. Wette, K. Whelan, J. T. Whitbeck, D. M. Whitcomb, S. E. Whiting, B. F. Wilkinson, C. Willems, P. A. Williams, L. Willke, B. Wilmut, I. Winkler, W. Wipf, C. C. Wise, S. Wiseman, A. G. Woan, G. Woods, D. Wooley, R. Worden, J. Wu, W. Yakushin, I. Yamamoto, H. Yan, Z. Yoshida, S. Yunes, N. Zanolin, M. Zhang, J. Zhang, L. Zhao, C. Zotov, N. Zucker, M. Muehlen, H. Zur Zweizig, J. TI Upper limit map of a background of gravitational waves SO PHYSICAL REVIEW D LA English DT Article ID ACCRETING NEUTRON-STARS; RADIATION AB We searched for an anisotropic background of gravitational waves using data from the LIGO S4 science run and a method that is optimized for point sources. This is appropriate if, for example, the gravitational wave background is dominated by a small number of distinct astrophysical sources. No signal was seen. Upper limit maps were produced assuming two different power laws for the source strain power spectrum. For an f(-3) power law and using the 50 Hz to 1.8 kHz band the upper limits on the source strain power spectrum vary between 1.2 x 10(-48) Hz(-1) (100 Hz/f)(3) and 1.2 x 10(-47) Hz(-1) (100 Hz/f)(3), depending on the position in the sky. Similarly, in the case of constant strain power spectrum, the upper limits vary between 8.5 x 10(-49) Hz(-1) and 6.1 x 10(-48) Hz(-1). As a side product a limit on an isotropic background of gravitational waves was also obtained. All limits are at the 90% confidence level. Finally, as an application, we focused on the direction of Sco-X1, the brightest low-mass x-ray binary. We compare the upper limit on strain amplitude obtained by this method to expectations based on the x-ray flux from Sco-X1. C1 [Aulbert, C.; Babak, S.; Krishnan, B.; Machenschalk, B.; Papa, M. A.; Prix, R.; Schutz, B. F.; Sintes, A. M.; Somiya, K.; Takahashi, H.; Whelan, J. T.] Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. [Ajith, P.; Allen, B.; Brinkmann, M.; Bunkowski, A.; Burmeister, O.; Cochrane, P.; Danzmann, K.; Grote, H.; Heurs, M.; Hewitson, M.; Mossavi, K.; Mueller-Ebhardt, H.; Pletsch, H.; Rainer, N.; Rehbein, H.; Ribichini, L.; Schilling, R.; Schnabel, R.; Seifert, F.; Smith, J. R.; Somiya, K.; Weidner, A.; Weinert, M.; Winkler, W.] Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-30167 Hannover, Germany. [Summerscales, T. Z.] Andrews Univ, Berrien Springs, MI 49104 USA. [Ashley, M.; Chow, J.; Dickson, J.; Gossler, S.; Gray, C.; Lam, P. K.; McClelland, D. E.; McKenzie, K.; MowLowry, C.; Moylan, A.; Rabeling, D.; Scott, S. M.; Searle, A. C.; Slagmolen, B. J. J.] Australian Natl Univ, Canberra, ACT 0200, Australia. [Drever, R. W. P.] CALTECH, Pasadena, CA 91125 USA. [Thorne, K. S.; Vallisneri, M.] CALTECH, CaRT, Pasadena, CA 91125 USA. [Cokelaer, T.; Davies, G.; Dietz, A.; Fairhurst, S.; Jones, G.; Romano, J. D.; Sathyaprakash, B. S.; Sengupta, A. S.; Van den Broeck, C.] Cardiff Univ, Cardiff CF23YB, Wales. [Bantilan, H.; Christensen, N.] Carleton Coll, Northfield, MN 55057 USA. [Charlton, P.] Charles Sturt Univ, Wagga Wagga, NSW 2678, Australia. Columbia Univ, New York, NY 10027 USA. Embry Riddle Aeronaut Univ, Prescott, AR USA. Hobart & William Smith Coll, Geneva, NY 14456 USA. Interuniv Ctr Astron & Astrophys, Pune 411007, Maharashtra, India. CALTECH, LIGO, Pasadena, CA 91125 USA. Hanford Observ, LIGO, Richland, WA 99352 USA. Livingston Observ, LIGO, Livingston, LA 70754 USA. MIT, LIGO, Cambridge, MA 02139 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Louisiana State Univ, Ruston, LA 71272 USA. Loyola Univ, New Orleans, LA 70118 USA. Moscow MV Lomonosov State Univ, Moscow 119992, Russia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Astron Observ, Tokyo 1818588, Japan. Northwestern Univ, Evanston, IL 60208 USA. Rochester Inst Technol, Rochester, NY 14623 USA. Rutherford Appleton Lab, Chilton OX110QX, England. San Jose State Univ, San Jose, CA 95192 USA. SE Louisiana Univ, Hammond, LA 70402 USA. Southern Univ, A&M Coll, Baton Rouge, LA 70813 USA. Stanford Univ, Stanford, CA 94305 USA. Syracuse Univ, Syracuse, NY 13244 USA. Penn State Univ, University Pk, PA 16802 USA. Univ Texas Brownsville & Texas Southmost Coll, Brownsville, TX 78520 USA. Trinity Univ, San Antonio, TX 78212 USA. Univ Illes Balears, Dept Fis, E-07122 Palma de Mallorca, Spain. Leibniz Univ Hannover, D-30167 Hannover, Germany. Univ Adelaide, Adelaide, SA 5005, Australia. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Univ Florida, Gainesville, FL 32611 USA. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Univ Maryland, College Pk, MA USA. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Rochester, Rochester, NY 14627 USA. Univ Salerno, I-84084 Salerno, Italy. Univ Sannio Benevento, I-82100 Benevento, Italy. Univ Southampton, Southampton, Hants SO171BJ, England. Univ Strathclyde, Glasgow G1 1XQ, Lanark, Scotland. Univ Washington, Seattle, WA 98195 USA. Univ Western Australia, Nedlands, WA 6009, Australia. Univ Wisconsin, Milwaukee, WI 53201 USA. Washington State Univ, Pullman, WA 99164 USA. RP Abbott, B (reprint author), Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. RI Howell, Eric/H-5072-2014; Ward, Robert/I-8032-2014; Finn, Lee Samuel/A-3452-2009; Agresti, Juri/G-8168-2012; Mitrofanov, Valery/D-8501-2012; Bilenko, Igor/D-5172-2012; Allen, Bruce/K-2327-2012; Chen, Yanbei/A-2604-2013; Barker, David/A-5671-2013; Zhao, Chunnong/C-2403-2013; Ju, Li/C-2623-2013; Pitkin, Matthew/I-3802-2013; Schutz, Bernard/B-1504-2010; Vyatchanin, Sergey/J-2238-2012; Khalili, Farit/D-8113-2012; Chiadini, Francesco/E-1812-2015; Vecchio, Alberto/F-8310-2015; Mow-Lowry, Conor/F-8843-2015; Ottaway, David/J-5908-2015; Postiglione, Fabio/O-4744-2015; Messaritaki, Eirini/D-7393-2016; Tarallo, Marco/B-2096-2012; Sigg, Daniel/I-4308-2015; Pinto, Innocenzo/L-3520-2016; Harms, Jan/J-4359-2012; Chow, Jong/A-3183-2008; Frey, Raymond/E-2830-2016; Barriga, Pablo/A-3929-2008; Lam, Ping Koy/A-5276-2008; McClelland, David/E-6765-2010; Martin, Iain/A-2445-2010; Hild, Stefan/A-3864-2010; Casey, Morag/C-9703-2010; Rowan, Sheila/E-3032-2010; Strain, Kenneth/D-5236-2011; Raab, Frederick/E-2222-2011; Lueck, Harald/F-7100-2011; Kawazoe, Fumiko/F-7700-2011; Freise, Andreas/F-8892-2011; Galdi, Vincenzo/B-1670-2008; Kawabe, Keita/G-9840-2011; OI Howell, Eric/0000-0001-7891-2817; LONGO, Maurizio/0000-0001-8325-4003; Pierro, Vincenzo/0000-0002-6020-5521; Ward, Robert/0000-0001-5503-5241; Whelan, John/0000-0001-5710-6576; Fairhurst, Stephen/0000-0001-8480-1961; Boschi, Valerio/0000-0001-8665-2293; Pinto, Innocenzo M./0000-0002-2679-4457; Stuver, Amber/0000-0003-0324-5735; Finn, Lee Samuel/0000-0002-3937-0688; Agresti, Juri/0000-0001-6119-2470; Allen, Bruce/0000-0003-4285-6256; Zhao, Chunnong/0000-0001-5825-2401; Pitkin, Matthew/0000-0003-4548-526X; Chiadini, Francesco/0000-0002-9339-8622; Vecchio, Alberto/0000-0002-6254-1617; Postiglione, Fabio/0000-0003-0628-3796; Tarallo, Marco/0000-0001-5169-4987; Sigg, Daniel/0000-0003-4606-6526; Chow, Jong/0000-0002-2414-5402; Frey, Raymond/0000-0003-0341-2636; Lam, Ping Koy/0000-0002-4421-601X; McClelland, David/0000-0001-6210-5842; Strain, Kenneth/0000-0002-2066-5355; Lueck, Harald/0000-0001-9350-4846; Galdi, Vincenzo/0000-0002-4796-3600; Freise, Andreas/0000-0001-6586-9901; MATTA, VINCENZO/0000-0002-2046-4027; MARANO, Stefano/0000-0002-5307-0980; Whiting, Bernard F/0000-0002-8501-8669; Veitch, John/0000-0002-6508-0713; Papa, M.Alessandra/0000-0002-1007-5298; Nishizawa, Atsushi/0000-0003-3562-0990; Zweizig, John/0000-0002-1521-3397; O'Shaughnessy, Richard/0000-0001-5832-8517; Aulbert, Carsten/0000-0002-1481-8319 NR 12 TC 67 Z9 67 U1 2 U2 17 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 J9 PHYS REV D JI Phys. Rev. D PD OCT PY 2007 VL 76 IS 8 AR 082003 DI 10.1103/PhysRevD.76.082003 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 226XI UT WOS:000250621400008 ER PT J AU Abbott, B Abbott, R Adhikari, R Agresti, J Ajith, P Allen, B Amin, R Anderson, SB Anderson, WG Arain, M Araya, M Armandula, H Ashley, M Aston, S Aufmuth, P Aulbert, C Babak, S Ballmer, S Bantilan, H Barish, BC Barker, C Barker, D Barr, B Barriga, P Barton, MA Bayer, K Belczynski, K Berukoff, SJ Betzwieser, J Beyersdorf, PT Bhawal, B Bilenko, IA Abbott Abbott Black, E Blackburn, K Blackburn, L Blair, B Bland, B Bogenstahl, J Bogue, L Bork, R Boschi, V Bose, S Brady, PR Braginsky, VB Brau, JE Brinkmann, M Brooks, A Brown, DA Bullington, A Bunkowski, A Buonanno, A Burmeister, O Busby, D Butler, WE Byer, RL Cadonati, L Cagnoli, G Camp, JB Cannizzo, J Cannon, K Cantley, CA Cao, J Cardenas, L Carter, K Casey, MM Castaldi, G Cepeda, C Chalkey, E Charlton, P Chatterji, S Chelkowski, S Chen, Y Chiadini, F Chin, D Chin, E Chow, J Christensen, N Clark, J Cochrane, P Cokelaer, T Colacino, CN Coldwell, R Coles, M Conte, R Cook, D Corbitt, T Coward, D Coyne, D Creighton, JDE Creighton, TD Croce, RP Crooks, DRM Cruise, AM Csatorday, P Cumming, A Cutler, C Dalrymple, J D'Ambrosio, E Danzmann, K Davies, G Daw, E Debra, D Degallaix, J Degree, M Delker, T Demma, T Dergachev, V Desai, S DeSalvo, R Dhurandhar, S Diaz, M Dickson, J Di Credico, A Diederichs, G Dietz, A Ding, H Doomes, EE Drever, RWP Dumas, JC Dupuis, RJ Dwyer, JG Ehrens, P Espinoza, E Etzel, T Evans, M Evans, T Fairhurst, S Fan, Y Fazi, D Fejer, MM Finn, LS Fiumara, V Fotopoulos, N Franzen, A Franzen, KY Freise, A Frey, R Fricke, T Fritschel, P Frolov, VV Fyffe, M Galdi, V Ganezer, KS Garofoli, J Gholami, I Giaime, JA Giampanis, S Giardina, KD Goda, K Goetz, E Goggin, LM Gonzalez, G Gossler, S Grant, A Gras, S Gray, C Gray, M Greenhalgh, J Gretarsson, AM Grosso, R Grote, H Grunewald, S Guenther, M Gustafson, R Hage, B Hammer, D Hanna, C Hanson, J Harms, J Harry, G Harstad, E Hayler, T Heefner, J Heinzel, G Heng, IS Heptonstall, A Heurs, M Hewitson, M Hild, S Hirose, E Hoak, D Hosken, D Hough, J Howell, E Hoyland, D Huttner, SH Ingram, D Innerhofer, E Ito, M Itoh, Y Ivanov, A Jackrel, D Jennrich, O Johnson, B Johnson, WW Johnston, WR Jones, DI Jones, G Jones, R Ju, L Kalmus, P Kalogera, V Kasprzyk, D Katsavounidis, E Kawabe, K Kawamura, S Kawazoe, F Kells, W Keppel, DG Khalili, FY Killow, CJ Kim, C King, P Kissell, JS Klimenko, S Kokeyama, K Kondrashov, V Kopparapu, RK Kozak, D Krishnan, B Kwee, P Lam, PK Landry, M Lantz, B Lazzarini, A Lee, B Lei, M Leiner, J Leonhardt, V Leonor, I Libbrecht, K Libson, A Lindquist, P Lockerbie, NA Logan, J Longo, M Lormand, M Lubinski, M Luck, H Machenschalk, B MacInnis, M Mageswaran, M Mailand, K Malec, M Mandic, V Marano, S Marka, S Markowitz, J Maros, E Martin, I Marx, JN Mason, K Matone, L Matta, V Mavalvala, N McCarthy, R McClelland, DE McGuire, SC McHugh, M McKenzie, K McNabb, JWC McWilliams, S Meier, T Melissinos, A Mendell, G Mercer, RA Meshkov, S Messaritaki, E Messenger, CJ Meyers, D Mikhailov, E Mitra, S Mitrofanov, VP Mitselmakher, G Mittleman, R Miyakawa, O Mohanty, S Moreno, G Mossavi, K MowLowry, C Moylan, A Mudge, D Mueller, G Mukherjee, S Muller-Ebhardt, H Munch, J Murray, P Myers, E Myers, J Nagano, S Nash, T Newton, G Nishizawa, A Nocera, F Numata, K Nutzman, P O'Reilly, B O'Shaughnessy, R Ottaway, DJ Overmier, H Owen, BJ Pan, Y Papa, MA Parameshwaraiah, V Parameswariah, C Patel, P Pedraza, M Penn, S Pierro, V Pinto, IM Pitkin, M Pletsch, H Plissi, MV Postiglione, F Prix, R Quetschke, V Raab, F Rabeling, D Radkins, H Rahkola, R Rainer, N Rakhmanov, M Ramsunder, M Rawlins, K Ray-Majumder, S Re, V Regimbau, T Rehbein, H Reid, S Reitze, DH Ribichini, L Richman, S Riesen, R Riles, K Rivera, B Robertson, NA Robinson, C Robison, EL Roddy, S Rodriguez, A Rogan, AM Rollins, J Romano, JD Romie, J Rong, H Route, R Rowan, S Rudiger, A Ruet, L Russell, P Ryan, K Sakata, S Samidi, M De la Jordana, LS Sandberg, V Sanders, GH Sannibale, V Saraf, S Sarin, P Sathyaprakash, B Sato, S Saulson, PR Savage, R Savov, P Sazonov, A Schediwy, S Schilling, R Schnabel, R Schofield, R Schutz, BF Schwinberg, P Scott, SM Searle, AC Sears, B Seifert, F Sellers, D Sengupta, AS Shawhan, P Shoemaker, DH Sibley, A Sidles, JA Siemens, X Sigg, D Sinha, S Sintes, AM Slagmolen, BJJ Slutsky, J Smith, JR Smith, MR Somiya, K Strain, KA Strand, NE Strom, DM Stuver, A Summerscales, TZ Sun, KX Sung, M Sutton, PJ Sylvestre, J Takahashi, H Takamori, A Tanner, DB Tarallo, M Taylor, R Taylor, R Thacker, J Thorne, KA Thorne, KS Thuring, A Tinto, M Tokmakov, KV Torres, C Torrie, C Traylor, G Trias, M Tyler, W Ugolini, D Ungarelli, C Urbanek, K Vahlbruch, H Vallisneri, M Van den Broeck, C Van Putten, M Varvella, M Vass, S Vecchio, A Veitch, J Veitch, P Villar, A Vorvick, C Vyachanin, SP Waldman, SJ Wallace, L Ward, H Ward, R Watts, K Webber, D Weidner, A Weinert, M Weinstein, A Weiss, R Wen, L Wen, S Wette, K Whelan, JT Whitbeck, DM Whitcomb, SE Whiting, BF Wiley, S Wilkinson, C Willems, PA Williams, L Willke, B Wilmut, I Winkler, W Wipf, CC Wise, S Wiseman, AG Woan, G Woods, D Wooley, R Worden, J Wu, W Yakushin, I Yamamoto, H Yan, Z Yoshida, S Yunes, N Zaleski, KD Zanolin, M Zhang, J Zhang, L Zhao, C Zotov, N Zucker, M Muhlen, HZ Zweizig, J AF Abbott, B. Abbott, R. Adhikari, R. Agresti, J. Ajith, P. Allen, B. Amin, R. Anderson, S. B. Anderson, W. G. Arain, M. Araya, M. Armandula, H. Ashley, M. Aston, S. Aufmuth, P. Aulbert, C. Babak, S. Ballmer, S. Bantilan, H. Barish, B. C. Barker, C. Barker, D. Barr, B. Barriga, P. Barton, M. A. Bayer, K. Belczynski, K. Berukoff, S. J. Betzwieser, J. Beyersdorf, P. T. Bhawal, B. Bilenko, I. A. Billingsley, G. Biswas, R. Black, E. Blackburn, K. Blackburn, L. Blair, B. Bland, B. Bogenstahl, J. Bogue, L. Bork, R. Boschi, V. Bose, S. Brady, P. R. Braginsky, V. B. Brau, J. E. Brinkmann, M. Brooks, A. Brown, D. A. Bullington, A. Bunkowski, A. Buonanno, A. Burmeister, O. Busby, D. Butler, W. E. Byer, R. L. Cadonati, L. Cagnoli, G. Camp, J. B. Cannizzo, J. Cannon, K. Cantley, C. A. Cao, J. Cardenas, L. Carter, K. Casey, M. M. Castaldi, G. Cepeda, C. Chalkey, E. Charlton, P. Chatterji, S. Chelkowski, S. Chen, Y. Chiadini, F. Chin, D. Chin, E. Chow, J. Christensen, N. Clark, J. Cochrane, P. Cokelaer, T. Colacino, C. N. Coldwell, R. Coles, M. Conte, R. Cook, D. Corbitt, T. Coward, D. Coyne, D. Creighton, J. D. E. Creighton, T. D. Croce, R. P. Crooks, D. R. M. Cruise, A. M. Csatorday, P. Cumming, A. Cutler, C. Dalrymple, J. D'Ambrosio, E. Danzmann, K. Davies, G. Daw, E. Debra, D. Degallaix, J. Degree, M. Delker, T. Demma, T. Dergachev, V. Desai, S. DeSalvo, R. Dhurandhar, S. Diaz, M. Dickson, J. Di Credico, A. Diederichs, G. Dietz, A. Ding, H. Doomes, E. E. Drever, R. W. P. Dumas, J. -C. Dupuis, R. J. Dwyer, J. G. Ehrens, P. Espinoza, E. Etzel, T. Evans, M. Evans, T. Fairhurst, S. Fan, Y. Fazi, D. Fejer, M. M. Finn, L. S. Fiumara, V. Fotopoulos, N. Franzen, A. Franzen, K. Y. Freise, A. Frey, R. Fricke, T. Fritschel, P. Frolov, V. V. Fyffe, M. Galdi, V. Ganezer, K. S. Garofoli, J. Gholami, I. Giaime, J. A. Giampanis, S. Giardina, K. D. Goda, K. Goetz, E. Goggin, L. M. Gonzalez, G. Gossler, S. Grant, A. Gras, S. Gray, C. Gray, M. Greenhalgh, J. Gretarsson, A. M. Grosso, R. Grote, H. Grunewald, S. Guenther, M. Gustafson, R. Hage, B. Hammer, D. Hanna, C. Hanson, J. Harms, J. Harry, G. Harstad, E. Hayler, T. Heefner, J. Heinzel, G. Heng, I. S. Heptonstall, A. Heurs, M. Hewitson, M. Hild, S. Hirose, E. Hoak, D. Hosken, D. Hough, J. Howell, E. Hoyland, D. Huttner, S. H. Ingram, D. Innerhofer, E. Ito, M. Itoh, Y. Ivanov, A. Jackrel, D. Jennrich, O. Johnson, B. Johnson, W. W. Johnston, W. R. Jones, D. I. Jones, G. Jones, R. Ju, L. Kalmus, P. Kalogera, V. Kasprzyk, D. Katsavounidis, E. Kawabe, K. Kawamura, S. Kawazoe, F. Kells, W. Keppel, D. G. Khalili, F. Ya. Killow, C. J. Kim, C. King, P. Kissell, J. S. Klimenko, S. Kokeyama, K. Kondrashov, V. Kopparapu, R. K. Kozak, D. Krishnan, B. Kwee, P. Lam, P. K. Landry, M. Lantz, B. Lazzarini, A. Lee, B. Lei, M. Leiner, J. Leonhardt, V. Leonor, I. Libbrecht, K. Libson, A. Lindquist, P. Lockerbie, N. A. Logan, J. Longo, M. Lormand, M. Lubinski, M. Lueck, H. Machenschalk, B. MacInnis, M. Mageswaran, M. Mailand, K. Malec, M. Mandic, V. Marano, S. Marka, S. Markowitz, J. Maros, E. Martin, I. Marx, J. N. Mason, K. Matone, L. Matta, V. Mavalvala, N. McCarthy, R. McClelland, D. E. McGuire, S. C. McHugh, M. McKenzie, K. McNabb, J. W. C. McWilliams, S. Meier, T. Melissinos, A. Mendell, G. Mercer, R. A. Meshkov, S. Messaritaki, E. Messenger, C. J. Meyers, D. Mikhailov, E. Mitra, S. Mitrofanov, V. P. Mitselmakher, G. Mittleman, R. Miyakawa, O. Mohanty, S. Moreno, G. Mossavi, K. MowLowry, C. Moylan, A. Mudge, D. Mueller, G. Mukherjee, S. Mueller-Ebhardt, H. Munch, J. Murray, P. Myers, E. Myers, J. Nagano, S. Nash, T. Newton, G. Nishizawa, A. Nocera, F. Numata, K. Nutzman, P. O'Reilly, B. O'Shaughnessy, R. Ottaway, D. J. Overmier, H. Owen, B. J. Pan, Y. Papa, M. A. Parameshwaraiah, V. Parameswariah, C. Patel, P. Pedraza, M. Penn, S. Pierro, V. Pinto, I. M. Pitkin, M. Pletsch, H. Plissi, M. V. Postiglione, F. Prix, R. Quetschke, V. Raab, F. Rabeling, D. Radkins, H. Rahkola, R. Rainer, N. Rakhmanov, M. Ramsunder, M. Rawlins, K. Ray-Majumder, S. Re, V. Regimbau, T. Rehbein, H. Reid, S. Reitze, D. H. Ribichini, L. Richman, S. Riesen, R. Riles, K. Rivera, B. Robertson, N. A. Robinson, C. Robison, E. L. Roddy, S. Rodriguez, A. Rogan, A. M. Rollins, J. Romano, J. D. Romie, J. Rong, H. Route, R. Rowan, S. Ruediger, A. Ruet, L. Russell, P. Ryan, K. Sakata, S. Samidi, M. De la Jordana, L. Sancho Sandberg, V. Sanders, G. H. Sannibale, V. Saraf, S. Sarin, P. Sathyaprakash, B. Sato, S. Saulson, P. R. Savage, R. Savov, P. Sazonov, A. Schediwy, S. Schilling, R. Schnabel, R. Schofield, R. Schutz, B. F. Schwinberg, P. Scott, S. M. Searle, A. C. Sears, B. Seifert, F. Sellers, D. Sengupta, A. S. Shawhan, P. Shoemaker, D. H. Sibley, A. Sidles, J. A. Siemens, X. Sigg, D. Sinha, S. Sintes, A. M. Slagmolen, B. J. J. Slutsky, J. Smith, J. R. Smith, M. R. Somiya, K. Strain, K. A. Strand, N. E. Strom, D. M. Stuver, A. Summerscales, T. Z. Sun, K. -X. Sung, M. Sutton, P. J. Sylvestre, J. Takahashi, H. Takamori, A. Tanner, D. B. Tarallo, M. Taylor, R. Taylor, R. Thacker, J. Thorne, K. A. Thorne, K. S. Thuering, A. Tinto, M. Tokmakov, K. V. Torres, C. Torrie, C. Traylor, G. Trias, M. Tyler, W. Ugolini, D. Ungarelli, C. Urbanek, K. Vahlbruch, H. Vallisneri, M. Van den Broeck, C. Van Putten, M. Varvella, M. Vass, S. Vecchio, A. Veitch, J. Veitch, P. Villar, A. Vorvick, C. Vyachanin, S. P. Waldman, S. J. Wallace, L. Ward, H. Ward, R. Watts, K. Webber, D. Weidner, A. Weinert, M. Weinstein, A. Weiss, R. Wen, L. Wen, S. Wette, K. Whelan, J. T. Whitbeck, D. M. Whitcomb, S. E. Whiting, B. F. Wiley, S. Wilkinson, C. Willems, P. A. Williams, L. Willke, B. Wilmut, I. Winkler, W. Wipf, C. C. Wise, S. Wiseman, A. G. Woan, G. Woods, D. Wooley, R. Worden, J. Wu, W. Yakushin, I. Yamamoto, H. Yan, Z. Yoshida, S. Yunes, N. Zaleski, K. D. Zanolin, M. Zhang, J. Zhang, L. Zhao, C. Zotov, N. Zucker, M. Muehlen, H. Zur Zweizig, J. TI Searches for periodic gravitational waves from unknown isolated sources and Scorpius X-1: Results from the second LIGO science run SO PHYSICAL REVIEW D LA English DT Article ID ACCRETING NEUTRON-STARS; RADIATION; X-1; PULSAR; EMISSION; BINARIES; PARALLAX; LIGO AB We carry out two searches for periodic gravitational waves using the most sensitive few hours of data from the second LIGO science run. Both searches exploit fully coherent matched filtering and cover wide areas of parameter space, an innovation over previous analyses which requires considerable algorithm development and computational power. The first search is targeted at isolated, previously unknown neutron stars, covers the entire sky in the frequency band 160-728.8 Hz, and assumes a frequency derivative of less than 4 x 10(-10) Hz/s. The second search targets the accreting neutron star in the low-mass x-ray binary Scorpius X-1 and covers the frequency bands 464-484 Hz and 604-624 Hz as well as the two relevant binary orbit parameters. Because of the high computational cost of these searches we limit the analyses to the most sensitive 10 hours and 6 hours of data, respectively. Given the limited sensitivity and duration of the analyzed data set, we do not attempt deep follow-up studies. Rather we concentrate on demonstrating the data analysis method on a real data set and present our results as upper limits over large volumes of the parameter space. In order to achieve this, we look for coincidences in parameter space between the Livingston and Hanford 4-km interferometers. For isolated neutron stars our 95% confidence level upper limits on the gravitational wave strain amplitude range from 6.6 x 10(-23) to 1 x 10(-21) across the frequency band; for Scorpius X-1 they range from 1.7 x 10(-22) to 1.3 x 10(-21) across the two 20-Hz frequency bands. The upper limits presented in this paper are the first broadband wide parameter space upper limits on periodic gravitational waves from coherent search techniques. The methods developed here lay the foundations for upcoming hierarchical searches of more sensitive data which may detect astrophysical signals. C1 [Aulbert, C.; Babak, S.; Chen, Y.; Gholami, I.; Grunewald, S.; Krishnan, B.; Papa, M. A.; Prix, R.; Takahashi, H.; Whelan, J. T.] Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. [Ajith, P.; Bunkowski, A.; Cochrane, P.; Danzmann, K.; Grote, H.; Heurs, M.; Hewitson, M.; Lueck, H.; Mossavi, K.; Mueller-Ebhardt, H.; Nagano, S.; Pletsch, H.; Rainer, N.; Rehbein, H.; Ribichini, L.; Ruediger, A.; Schilling, R.; Schnabel, R.; Seifert, F.; Smith, J. R.; Somiya, K.; Weidner, A.; Weinert, M.] Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Hannover, Germany. [Summerscales, T. Z.] Andrews Univ, Berrien Springs, MI 49104 USA. [Ashley, M.; Dickson, J.; Gossler, S.; McClelland, D. E.; McKenzie, K.; MowLowry, C.; Moylan, A.; Rabeling, D.; Scott, S. M.; Searle, A. C.; Slagmolen, B. J. J.; Wette, K.] Australian Natl Univ, Canberra, ACT 0200, Australia. [Drever, R. W. P.; Tinto, M.] CALTECH, Pasadena, CA 91125 USA. [Ganezer, K. S.] Calif State Univ Dominguez Hills, Carson, CA 90747 USA. [Brown, D. A.; Cutler, C.; Siemens, X.; Thorne, K. S.; Vallisneri, M.] CALTECH, CaRT, Pasadena, CA 91125 USA. [Cokelaer, T.; Davies, G.; Dietz, A.; Jones, G.; Robinson, C.; Romano, J. D.; Sathyaprakash, B.; Schutz, B. F.; Sengupta, A. S.; Van den Broeck, C.] Cardiff Univ, Cardiff CF2 3YB, Wales. [Bantilan, H.; Christensen, N.; Libson, A.] Carleton Coll, Northfield, MN 55057 USA. [Charlton, P.] Charles Sturt Univ, Wagga Wagga, NSW 2678, Australia. [Dwyer, J. G.; Kalmus, P.; Marka, S.; Matone, L.] Columbia Univ, New York, NY 10027 USA. [Grosso, R.] Embry Riddle Aeronaut Univ, Prescott, AZ 86301 USA. [Penn, S.] Hobart & William Smith Coll, Geneva, NY 14456 USA. [Dhurandhar, S.; Mitra, S.] Interuniv Ctr Astron & Astrophys, Pune 411007, Maharashtra, India. [Abbott, B.; Abbott, R.; Adhikari, R.; Agresti, J.; Anderson, S. B.; Araya, M.; Armandula, H.; Ballmer, S.; Barish, B. C.; Bhawal, B.; Billingsley, G.; Black, E.; Blackburn, K.; Bork, R.; Boschi, V.; Brown, D. A.; Busby, D.; Cardenas, L.; Cepeda, C.; Chatterji, S.; Coyne, D.; Creighton, T. D.; D'Ambrosio, E.; DeSalvo, R.; Ding, H.; Dupuis, R. J.; Ehrens, P.; Espinoza, E.; Evans, M.; Fairhurst, S.; Fazi, D.; Goggin, L. M.; Heefner, J.; Ivanov, A.; Kells, W.; Keppel, D. G.; King, P.; Kondrashov, V.; Kozak, D.; Lazzarini, A.; Lei, M.; Libbrecht, K.; Lindquist, P.; Logan, J.; Mageswaran, M.; Mailand, K.; Mandic, V.; Maros, E.; Marx, J. N.; Messaritaki, E.; Messenger, C. J.; Meyers, D.; Miyakawa, O.; Nash, T.; Nocera, F.; Patel, P.; Pedraza, M.; Robertson, N. A.; Russell, P.; Samidi, M.; Sanders, G. H.; Sears, B.; Siemens, X.; Smith, M. R.; Sutton, P. J.; Sylvestre, J.; Takamori, A.; Tarallo, M.; Taylor, R.; Tyler, W.; Varvella, M.; Vass, S.; Villar, A.; Waldman, S. J.; Wallace, L.; Ward, R.; Webber, D.; Weinstein, A.; Whitcomb, S. E.; Willems, P. A.; Yamamoto, H.; Zhang, L.; Zweizig, J.] CALTECH, LIGO, Pasadena, CA 91125 USA. [Barish, B. C.; Barker, C.; Barker, D.; Bland, B.; Cook, D.; Garofoli, J.; Guenther, M.; Ingram, D.; Johnson, B.; Kawabe, K.; Landry, M.; Lubinski, M.; McCarthy, R.; Mendell, G.; Moreno, G.; Myers, E.; Myers, J.; Parameshwaraiah, V.; Raab, F.; Radkins, H.; Rivera, B.; Ryan, K.; Sandberg, V.; Savage, R.; Schwinberg, P.; Sigg, D.; Vorvick, C.; Wilkinson, C.] LIGO Hanford Observ, Richland, WA 99352 USA. [Bogue, L.; Carter, K.; Coles, M.; Evans, T.; Frolov, V. V.; Fyffe, M.; Giaime, J. A.; Giardina, K. D.; Hanson, J.; Hoak, D.; Lormand, M.; O'Reilly, B.; Overmier, H.; Parameswariah, C.; Riesen, R.; Roddy, S.; Romie, J.; Sellers, D.; Sibley, A.; Thacker, J.; Traylor, G.; Watts, K.; Wooley, R.; Yakushin, I.] LIGO Livingston Observ, Livingston, LA 70754 USA. [Bayer, K.; Betzwieser, J.; Blackburn, L.; Cadonati, L.; Cao, J.; Corbitt, T.; Csatorday, P.; Fritschel, P.; Goda, K.; Harry, G.; Innerhofer, E.; Katsavounidis, E.; MacInnis, M.; Markowitz, J.; Mason, K.; Mavalvala, N.; Mikhailov, E.; Mittleman, R.; Ottaway, D. J.; Rawlins, K.; Richman, S.; Ruet, L.; Sarin, P.; Shoemaker, D. H.; Van Putten, M.; Weiss, R.; Wipf, C. C.; Zanolin, M.; Zucker, M.] MIT, LIGO, Cambridge, MA 02139 USA. [Amin, R.; Giaime, J. A.; Gonzalez, G.; Hanna, C.; Johnson, W. W.; Kissell, J. S.; Kopparapu, R. K.; Rodriguez, A.; Slutsky, J.; Sung, M.; Wen, S.] Louisiana State Univ, Baton Rouge, LA 70803 USA. [Zotov, N.] Louisiana Tech Univ, Ruston, LA 71272 USA. [McHugh, M.] Loyola Univ, New Orleans, LA 70118 USA. Max Planck Inst Quantum Opt, D-85748 Garching, Germany. [Bilenko, I. A.; Braginsky, V. B.; Khalili, F. Ya.; Mitrofanov, V. P.] Moscow MV Lomonosov State Univ, Moscow 119992, Russia. [Camp, J. B.; Cannizzo, J.; McWilliams, S.; Numata, K.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Kawamura, S.; Kawazoe, F.; Kokeyama, K.; Leonhardt, V.; Nishizawa, A.; Sakata, S.; Sato, S.] Natl Astron Observ, Tokyo 1818588, Japan. [Belczynski, K.; Kalogera, V.; Kim, C.; Nutzman, P.; O'Shaughnessy, R.] Northwestern Univ, Evanston, IL 60208 USA. [Saraf, S.] Rochester Inst Technol, Rochester, NY 14623 USA. [Greenhalgh, J.; Hayler, T.; Wilmut, I.] Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. [Beyersdorf, P. T.] San Jose State Univ, San Jose, CA 95192 USA. [Yoshida, S.] SE Louisiana Univ, Hammond, LA 70402 USA. [Doomes, E. E.; McGuire, S. C.] Southern Univ, A&M Coll, Baton Rouge, LA 70813 USA. [Bullington, A.; Byer, R. L.; Debra, D.; Degree, M.; Fejer, M. M.; Jackrel, D.; Lantz, B.; Route, R.; Sinha, S.; Sun, K. -X.; Urbanek, K.] Stanford Univ, Stanford, CA 94305 USA. [Dalrymple, J.; Di Credico, A.; Hirose, E.; Saulson, P. R.] Syracuse Univ, Syracuse, NY 13244 USA. [Strand, N. E.; Stuver, A.; Thorne, K. A.; Whitbeck, D. M.; Yunes, N.; Zaleski, K. D.] Penn State Univ, University Pk, PA 16802 USA. [Diaz, M.; Grosso, R.; Johnston, W. R.; Mukherjee, S.; Torres, C.] Univ Texas Brownsville & Texas Southmost Coll, Brownsville, TX 78520 USA. [Ugolini, D.] Trinity Univ, San Antonio, TX 78212 USA. [De la Jordana, L. Sancho; Sintes, A. M.; Trias, M.] Univ Illes Balears, E-07122 Palma de Mallorca, Spain. [Aufmuth, P.; Danzmann, K.; Diederichs, G.; Franzen, A.; Hage, B.; Hild, S.; Kwee, P.; Lueck, H.; Malec, M.; Meier, T.; Thuering, A.; Vahlbruch, H.; Willke, B.; Muehlen, H. Zur] Leibniz Univ Hannover, D-30167 Hannover, Germany. [Brooks, A.; Hough, J.; Mudge, D.; Munch, J.; Veitch, P.] Univ Adelaide, Adelaide, SA 5005, Australia. [Aston, S.; Freise, A.; Kasprzyk, D.; Re, V.; Robison, E. L.; Ungarelli, C.; Vecchio, A.] Univ Birmingham, Birmingham B15 2TT, W Midlands, England. [Coldwell, R.; Delker, T.; Franzen, K. Y.; Klimenko, S.; Mercer, R. A.; Meshkov, S.; Mitselmakher, G.; Mittleman, R.; Mueller, G.; Quetschke, V.; Reitze, D. H.; Rong, H.; Sazonov, A.; Tanner, D. B.; Whiting, B. F.; Williams, L.; Wise, S.; Wu, W.] Univ Florida, Gainesville, FL 32611 USA. [Barton, M. A.; Bogenstahl, J.; Cagnoli, G.; Casey, M. M.; Chalkey, E.; Clark, J.; Crooks, D. R. M.; Cumming, A.; Grant, A.; Heng, I. S.; Heptonstall, A.; Hough, J.; Huttner, S. H.; Jennrich, O.; Jones, R.; Killow, C. J.; Martin, I.; Messenger, C. J.; Murray, P.; Newton, G.; Pitkin, M.; Pletsch, H.; Plissi, M. V.; Reid, S.; Robertson, N. A.; Rowan, S.; Taylor, R.; Tokmakov, K. V.; Torrie, C.; Veitch, J.; Ward, H.; Woan, G.] Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. [Buonanno, A.; Pan, Y.; Shawhan, P.] Univ Maryland, College Pk, MA USA. [Chin, D.; Dergachev, V.; Gustafson, R.; Riles, K.; Zhang, J.] Univ Michigan, Ann Arbor, MI 48109 USA. [Brau, J. E.; Frey, R.; Harstad, E.; Ito, M.; Leonor, I.; Rahkola, R.; Schofield, R.] Univ Oregon, Eugene, OR 97403 USA. [Butler, W. E.; Fricke, T.; Giampanis, S.; Melissinos, A.; Strom, D. M.] Univ Rochester, Rochester, NY 14627 USA. [Chiadini, F.; Conte, R.; Fiumara, V.; Longo, M.; Marano, S.; Matta, V.; Postiglione, F.] Univ Salerno, I-84084 Salerno, Italy. [Castaldi, G.; Croce, R. P.; Demma, T.; Galdi, V.; Pierro, V.; Pinto, I. M.] Univ Sannio, I-82100 Benevento, Italy. [Daw, E.] Univ Sheffield, Sheffield S3 7RH, S Yorkshire, England. [Jones, D. I.] Univ Southampton, Southampton, Hants SO171BJ, England. [Lockerbie, N. A.] Univ Strathclyde, Glasgow G1 1XQ, Lanark, Scotland. [Sidles, J. A.] Univ Washington, Seattle, WA 98195 USA. [Barriga, P.; Blair, B.; Chin, E.; Coward, D.; Degallaix, J.; Dumas, J. -C.; Fan, Y.; Gras, S.; Howell, E.; Ju, L.; Lee, B.; Schediwy, S.; Yan, Z.; Zhao, C.] Univ Western Australia, Nedlands, WA 6009, Australia. [Allen, B.; Anderson, W. G.; Biswas, R.; Brady, P. R.; Cannon, K.; Creighton, J. D. E.; Fotopoulos, N.; Hammer, D.; Itoh, Y.; Papa, M. A.; Ray-Majumder, S.; Wiseman, A. G.] Univ Wisconsin, Milwaukee, WI 53201 USA. Vassar Coll, Poughkeepsie, NY 12604 USA. [Bose, S.; Leiner, J.; Rogan, A. M.] Washington State Univ, Pullman, WA 99164 USA. RP Abbott, B (reprint author), Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. RI van Putten, Maurice/F-5237-2011; Khalili, Farit/D-8113-2012; Chiadini, Francesco/E-1812-2015; Vecchio, Alberto/F-8310-2015; Mow-Lowry, Conor/F-8843-2015; Ottaway, David/J-5908-2015; Postiglione, Fabio/O-4744-2015; Messaritaki, Eirini/D-7393-2016; Tarallo, Marco/B-2096-2012; Sigg, Daniel/I-4308-2015; Pinto, Innocenzo/L-3520-2016; Harms, Jan/J-4359-2012; Chow, Jong/A-3183-2008; Frey, Raymond/E-2830-2016; Howell, Eric/H-5072-2014; Ward, Robert/I-8032-2014; Kawabe, Keita/G-9840-2011; Finn, Lee Samuel/A-3452-2009; Agresti, Juri/G-8168-2012; Mitrofanov, Valery/D-8501-2012; Allen, Bruce/K-2327-2012; Chen, Yanbei/A-2604-2013; Barker, David/A-5671-2013; Zhao, Chunnong/C-2403-2013; Ju, Li/C-2623-2013; Pitkin, Matthew/I-3802-2013; Sylvestre, Julien/A-8610-2009; Vyatchanin, Sergey/J-2238-2012; Barriga, Pablo/A-3929-2008; Kawazoe, Fumiko/F-7700-2011; Lam, Ping Koy/A-5276-2008; Galdi, Vincenzo/B-1670-2008; McClelland, David/E-6765-2010; Martin, Iain/A-2445-2010; Hild, Stefan/A-3864-2010; Casey, Morag/C-9703-2010; Rowan, Sheila/E-3032-2010; Strain, Kenneth/D-5236-2011; Raab, Frederick/E-2222-2011; Lueck, Harald/F-7100-2011; Freise, Andreas/F-8892-2011; OI Chiadini, Francesco/0000-0002-9339-8622; Vecchio, Alberto/0000-0002-6254-1617; Postiglione, Fabio/0000-0003-0628-3796; Tarallo, Marco/0000-0001-5169-4987; Sigg, Daniel/0000-0003-4606-6526; Chow, Jong/0000-0002-2414-5402; Stuver, Amber/0000-0003-0324-5735; Nishizawa, Atsushi/0000-0003-3562-0990; Zweizig, John/0000-0002-1521-3397; O'Shaughnessy, Richard/0000-0001-5832-8517; Frey, Raymond/0000-0003-0341-2636; Howell, Eric/0000-0001-7891-2817; LONGO, Maurizio/0000-0001-8325-4003; Pierro, Vincenzo/0000-0002-6020-5521; Ward, Robert/0000-0001-5503-5241; Whelan, John/0000-0001-5710-6576; Fairhurst, Stephen/0000-0001-8480-1961; Boschi, Valerio/0000-0001-8665-2293; Pinto, Innocenzo M./0000-0002-2679-4457; Finn, Lee Samuel/0000-0002-3937-0688; Agresti, Juri/0000-0001-6119-2470; Allen, Bruce/0000-0003-4285-6256; Zhao, Chunnong/0000-0001-5825-2401; Pitkin, Matthew/0000-0003-4548-526X; Sylvestre, Julien/0000-0001-8136-4348; Lam, Ping Koy/0000-0002-4421-601X; Galdi, Vincenzo/0000-0002-4796-3600; McClelland, David/0000-0001-6210-5842; Strain, Kenneth/0000-0002-2066-5355; Lueck, Harald/0000-0001-9350-4846; Freise, Andreas/0000-0001-6586-9901; MATTA, VINCENZO/0000-0002-2046-4027; MARANO, Stefano/0000-0002-5307-0980; Whiting, Bernard F/0000-0002-8501-8669 NR 52 TC 92 Z9 92 U1 2 U2 13 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 OCT PY 2007 VL 76 IS 8 AR 082001 DI 10.1103/PhysRevD.76.082001 PG 35 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 226XI UT WOS:000250621400006 ER PT J AU Borovsky, JE Hesse, M AF Borovsky, Joseph E. Hesse, Michael TI The reconnection of magnetic fields between plasmas with different densities: Scaling relations SO PHYSICS OF PLASMAS LA English DT Article ID DAYSIDE MAGNETOPAUSE; EARTHS MAGNETOPAUSE; LAYER; MAGNETOSPHERE; ENVIRONMENT; CHALLENGE AB Using two-dimensional compressible-magnetohydrodynamic computer simulations, the reconnection of magnetic fields between two plasmas with different mass densities is examined. Antiparallel, undriven merging is studied from a Harris-sheet initial condition with the sheet separating the two different plasmas. Reconnection is initiated with a resistive spot in the center of the Harris sheet. Density ratios from 1 to 320 are simulated. It is found that the rate of magnetic-field reconnection R is give approximately as R=0.07 upsilon(Ah), where upsilon(Ah)=B/[4 pi(0.5 rho(1)+0.5 rho(1))](1/2) is a hybrid Alfven speed constructed by averaging the densities of the two plasmas. In the symmetric-density case, plasma jetting speeds are equal to the local ExB velocity; in the asymmetric-density cases, the plasma jetting speeds exceed the local ExB velocity. In the asymmetric cases, plasma jetting tends to be parallel to the local magnetic field. In the symmetric-density case the plasma jetting arises from the site of the X-line and resides in the region of magnetic-field reversal; in the asymmetric case, jetting tends to reside in the lower-density plasma. (C) 2007 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Borovsky, JE (reprint author), Los Alamos Natl Lab, Mail Stop D466, Los Alamos, NM 87545 USA. RI Hesse, Michael/D-2031-2012; NASA MMS, Science Team/J-5393-2013 OI NASA MMS, Science Team/0000-0002-9504-5214 NR 33 TC 48 Z9 48 U1 1 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD OCT PY 2007 VL 14 IS 10 AR 102309 DI 10.1063/1.2772619 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 226LD UT WOS:000250589700027 ER PT J AU Goebel, DM Jameson, KK Katz, I Mikellides, IG AF Goebel, Dan M. Jameson, Kristina K. Katz, Ira Mikellides, Ioannis G. TI Potential fluctuations and energetic ion production in hollow cathode discharges SO PHYSICS OF PLASMAS LA English DT Article ID KEEPER; PROBES; WEAR AB Ions with energies significantly in excess of the applied discharge voltage have been reported for many years in hollow cathode discharges. Models of dc potential hills downstream of the cathode and instabilities in postulated double layers in the cathode orifice have been proposed to explain this, but have not been substantiated. Measurements of the dc and rf plasma density and potential profiles near the exit of hollow cathodes by miniature fast-scanning probes suggests that turbulent ion acoustic fluctuations and ionization instabilities in the cathode plume significantly increase the energy of the ions that flow from this region. Increases in the discharge current and/or decreases in the cathode gas flow enhance the amplitude of the fluctuations and increase the number and energy of the energetic ions, which increases the erosion rate of the cathode electrodes. The transition from the quiescent "spot mode" to the noisy "plume mode" characteristic of these discharges is found to be a gradual transition of increasing fluctuation amplitudes. (C) 2007 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Goebel, DM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM dan.m.goebel@jpl.nasa.gov NR 38 TC 16 Z9 16 U1 0 U2 17 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 OCT PY 2007 VL 14 IS 10 AR 103508 DI 10.1063/1.2784460 PG 15 WC Physics, Fluids & Plasmas SC Physics GA 226LD UT WOS:000250589700089 ER PT J AU Shebalin, JV AF Shebalin, John V. TI Broken symmetries and magnetic dynamos SO PHYSICS OF PLASMAS LA English DT Article ID MAGNETOHYDRODYNAMIC TURBULENCE; ISOTROPIC TURBULENCE; 3-DIMENSIONAL MAGNETOHYDRODYNAMICS; HOMOGENEOUS TURBULENCE; RELAXATION; ERGODICITY; ROTATION; FIELDS; SPACE AB Phase space symmetries inherent in the statistical theory of ideal magnetohydrodynamic (MHD) turbulence are known to be broken dynamically to produce large-scale coherent magnetic structure. Here, results of a numerical study of decaying MHD turbulence are presented that show large-scale coherent structure also arises and persists in the presence of dissipation. Dynamically broken symmetries in MHD turbulence may thus play a fundamental role in the dynamo process. C1 NASA, Lyndon B Johnson Space Ctr, Astronmat Res & Explorat Sci Off, Houston, TX 77058 USA. RP Shebalin, JV (reprint author), NASA, Lyndon B Johnson Space Ctr, Astronmat Res & Explorat Sci Off, Houston, TX 77058 USA. NR 31 TC 12 Z9 12 U1 0 U2 0 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 OCT PY 2007 VL 14 IS 10 AR 102301 DI 10.1063/1.2780138 PG 12 WC Physics, Fluids & Plasmas SC Physics GA 226LD UT WOS:000250589700019 ER PT J AU Drossart, P Piccioni, G Adriani, A Angrilli, F Arnold, G Baines, KH Bellucci, G Benkhoff, J Bezard, B Bibring, JP Blanco, A Blecka, MI Carlson, RW Coradini, A Di Lellis, A Encrenaz, T Erard, S Fonti, S Formisano, V Fouchet, T Garcia, R Haus, R Helbert, J Ignatiev, NI Irwin, PGJ Langevin, Y Lebonnois, S Lopez-Valverde, MA Luz, D Marinangeli, L Orofino, V Rodin, AV Roos-Serote, MC Saggin, B Sanchez-Lavega, A Stam, DM Taylor, FW Titov, D Visconti, G Zambelli, M Hueso, R Tsang, CCC Wilson, CF Afanasenko, TZ AF Drossart, P. Piccioni, G. Adriani, A. Angrilli, F. Arnold, G. Baines, K. H. Bellucci, G. Benkhoff, J. Bezard, B. Bibring, J.-P. Blanco, A. Blecka, M. I. Carlson, R. W. Coradini, A. Di Lellis, A. Encrenaz, T. Erard, S. Fonti, S. Formisano, V. Fouchet, T. Garcia, R. Haus, R. Helbert, J. Ignatiev, N. I. Irwin, P. G. J. Langevin, Y. Lebonnois, S. Lopez-Valverde, M. A. Luz, D. Marinangeli, L. Orofino, V. Rodin, A. V. Roos-Serote, M. C. Saggin, B. Sanchez-Lavega, A. Stam, D. M. Taylor, F. W. Titov, D. Visconti, G. Zambelli, M. Hueso, R. Tsang, C. C. C. Wilson, C. F. Afanasenko, T. Z. TI Scientific goals for the observation of Venus by VIRTIS on ESA/Venus express mission SO PLANETARY AND SPACE SCIENCE LA English DT Review DE Spectroscopy; radiative transfer; dynamics; Venus; Venus express ID INFRARED MAPPING SPECTROMETER; LOWER ATMOSPHERE; DEEP ATMOSPHERE; CLOUD STRUCTURE; NIGHT-SIDE; THERMAL-RADIATION; CARBON-MONOXIDE; GRAVITY-WAVES; PIONEER-VENUS; NIMS-GALILEO AB The Visible and Infrared Thermal Imaging Spectrometer (VIRTIS), on board the ESA/Venus Express mission has technical specifications well suited for many science objectives of Venus exploration. VIRTIS will both comprehensively explore a plethora of atmospheric properties and processes and map optical properties of the surface through its three channels, VIRTIS-M-vis (imaging spectrometer in the 0.3-1 mu m range), VIRTIS-M-IR (imaging spectrometer in the 1-5 mu m range) and VIRTIS-H (aperture high-resolution spectrometer in the 2-5 mu m range). The atmospheric composition below the clouds will be repeatedly measured in the night side infrared windows over a wide range of latitudes and longitudes, thereby providing information on Venus's chemical cycles. in particular, CO, H2O, OCS and SO2 can be studied. The cloud structure will be repeatedly mapped from the brightness contrasts in the near-infrared night side windows, providing new insights into Venusian meteorology. The global circulation and local dynamics of Venus will be extensively studied from infrared and visible spectral images. The thermal structure above the clouds will be retrieved in the night side using the 4.3 mu m fundamental band of CO2. The surface of Venus is detectable in the short-wave infrared windows on the night side at 1.0 1, 1.10 and 1.18 mu m, providing constraints on surface properties and the extent of active volcanism. Many more tentative studies are also possible, such as lightning detection, the composition of volcanic emissions, and mesospheric wave propagation. (C) 2007 Elsevier Ltd. All rights reserved. C1 Observ Paris, CNRS, UMR 8109, LESIA, F-92195 Meudon, France. INAF IASF, I-00133 Rome, Italy. INAF IFSI, I-00133 Rome, Italy. CISAS, I-35131 Padua, Italy. Deutsche Zentrum Luft & Raumfahrt, D-12489 Berlin, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. IAS, F-91405 Orsay, France. Univ Lecce, I-73100 Lecce, Italy. Space Res Ctr, PL-00716 Warsaw, Poland. Univ Paris 07, IPGP, UMR7154, F-94107 St Maur, France. Moscow Space Res Inst, Moscow 117810, Russia. Univ Oxford, Oxford OX1 3PU, England. Meteorol Dynam Lab, Paris 05, France. Inst Astrofis Andalucia, E-18080 Granada, Spain. Observ Astron Lisboa, CAAUL, P-1349018 Lisbon, Portugal. Univ Annunzio, I-65127 Pescara, Italy. Politecn Milan, I-23900 Lecce, Italy. Univ Basque Country, Escuela Super Ingn, Bilbao 48013, Spain. Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Max Planck Inst Solar Syst Studies, D-37191 Katlenburg Lindau, Germany. RP Drossart, P (reprint author), Observ Paris, CNRS, UMR 8109, LESIA, 5 Pl Jules Janssen, F-92195 Meudon, France. EM pierre.drossart@obspm.fr; giuseppe.piccioni@iasf-roma.inaf.it RI Garcia, Raphael/B-2612-2012; Luz, David/J-4588-2013; Rodin, Alexander/L-1904-2013; Fouchet, Thierry/C-6374-2017; OI Irwin, Patrick/0000-0002-6772-384X; Luz, David/0000-0002-9473-8035; Lopez-Valverde, M. A./0000-0002-7989-4267; Rodin, Alexander/0000-0002-3601-7790; Fouchet, Thierry/0000-0001-9040-8285; Helbert, Jorn/0000-0001-5346-9505; Bellucci, Giancarlo/0000-0003-0867-8679; Adriani, Alberto/0000-0003-4998-8008; Sanchez-Lavega, Agustin/0000-0001-7355-1522; Piccioni, Giuseppe/0000-0002-7893-6808; Hueso, Ricardo/0000-0003-0169-123X; saggin, bortolino/0000-0002-4033-3585 NR 104 TC 104 Z9 103 U1 1 U2 18 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 OCT PY 2007 VL 55 IS 12 BP 1653 EP 1672 DI 10.1016/j.pss.2007.01.003 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 227CX UT WOS:000250635900003 ER PT J AU Markiewicz, WJ Titov, DV Ignatiev, N Keller, HU Crisp, D Limaye, SS Jaumann, R Moissl, R Thomas, N Esposito, L Watanabe, S Fiethe, B Behnke, T Szemerey, I Michalik, H PerplieS, H Wedemeier, M Sebastian, I Boogaerts, W Hviid, SF Dierker, C Osterloh, B Boker, W Koch, M Michaelis, H Belyaev, D Dannenberg, A Tschimmel, M Russo, P Roatsch, T Matz, KD AF Markiewicz, W. J. Titov, D. V. Ignatiev, N. Keller, H. U. Crisp, D. Limaye, S. S. Jaumann, R. Moissl, R. Thomas, N. Esposito, L. Watanabe, S. Fiethe, B. Behnke, T. Szemerey, I. Michalik, H. Perplies, H. Wedemeier, M. Sebastian, I. Boogaerts, W. Hviid, S. F. Dierker, C. Osterloh, B. Boeker, W. Koch, M. Michaelis, H. Belyaev, D. Dannenberg, A. Tschimmel, M. Russo, P. Roatsch, T. Matz, K. D. TI Venus monitoring camera for Venus express SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Venus; instrument; atmosphere; dynamics; clouds ID CLOUD PHOTOPOLARIMETER IMAGES; WATER-VAPOR; LEVEL CIRCULATION; MIDDLE ATMOSPHERE; SURFACE; RADIATION; GALILEO; NIGHTSIDE; ALTITUDE; SPECTRA AB The Venus Express mission will focus on a global investigation of the Venus atmosphere and plasma environment, while additionally measuring some surface properties from orbit. The instruments PFS and SPICAV inherited from the Mars Express mission and VIRTIS from Rosetta form a powerful spectrometric and spectro-imaging payload suite. Venus Monitoring Camera (VMC)-a miniature wide-angle camera with 17.5 degrees field of view-was specifically designed and built to complement these experiments and provide imaging context for the whole mission. VMC will take images of Venus in four narrow band filters (365, 513, 965, and 1000 nm) all sharing one CCD. Spatial resolution on the cloud tops will range from 0.2 km/px at pericentre to 45 km/px at apocentre when the full Venus disc will be in the field of view. VMC will fulfill the following science goals: (1) study of the distribution and nature of the unknown UV absorber; (2) determination of the wind field at the cloud tops (70km) by tracking the UV features; (3) thermal mapping of the surface in the I Pm transparency "window" on the night side; (4) determination of the global wind field in the main cloud deck (50 km) by tracking near-IR features; (5) study of the lapse rate and H2O content in the lower 6-10km; (6) mapping 02 night-glow and its variability. (C) 2007 Elsevier Ltd. All rights reserved. C1 Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. Tech Univ Carolo Wilhelmina Braunschweig, IDA, Braunschweig, Germany. DLR, Berlin, Germany. Moscow Space Res Inst, Moscow 117810, Russia. Jet Propuls Lab, Pasadena, CA USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Univ Wisconsin, Madison, WI USA. Hokkaido Univ, Sapporo, Hokkaido 060, Japan. Univ Bern, CH-3012 Bern, Switzerland. RP Markiewicz, WJ (reprint author), Max Planck Inst Sonnensyst Forsch, Max Planck Str 2, D-37191 Katlenburg Lindau, Germany. EM markiewiczo@mps.mpg.de; titov@mps.mpg.de RI Watanabe, Shigeto/A-4305-2012 NR 40 TC 50 Z9 50 U1 1 U2 8 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 OCT PY 2007 VL 55 IS 12 BP 1701 EP 1711 DI 10.1016/j.pss.2007.01.004 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 227CX UT WOS:000250635900005 ER PT J AU Mills, FP Allen, M AF Mills, Franklin P. Allen, Mark TI A review of selected issues concerning the chemistry in Venus' middle atmosphere SO PLANETARY AND SPACE SCIENCE LA English DT Review DE Venus; atmosphere; chemical composition ID ABSORPTION CROSS-SECTIONS; SULFURIC-ACID AEROSOL; TEMPERATURE-DEPENDENCE; MARTIAN ATMOSPHERE; WAVELENGTH REGION; MOLECULAR-OXYGEN; CARBON-MONOXIDE; 193 NM; CHEMICAL-COMPOSITION; ELEMENTARY REACTIONS AB Even after decades of study using advanced observing instruments and sophisticated numerical models, a number of significant questions remain unanswered concerning the composition and chemistry of Venus' atmosphere. The primary chemical cycles and the interactions among sulfur and chlorine radicals in Venus' middle atmosphere are reviewed to assess the current status of our knowledge, identify unresolved questions, and assess how the Venus Express mission may contribute to their resolution. (C) 2007 Elsevier Ltd. All rights reserved. C1 Australian Natl Univ, Res Sch Phys Sci & Engn, Canberra, ACT 0200, Australia. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mills, FP (reprint author), Australian Natl Univ, Res Sch Phys Sci & Engn, Canberra, ACT 0200, Australia. EM Frank.Mills@anu.edu.au NR 109 TC 40 Z9 40 U1 3 U2 13 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 OCT PY 2007 VL 55 IS 12 BP 1729 EP 1740 DI 10.1016/j.pss.2007.01.012 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 227CX UT WOS:000250635900007 ER PT J AU Lopez-Valverde, MA Drossart, P Carlson, R Mehlman, R Roos-Serote, M AF Lopez-Valverde, M. A. Drossart, Pierre Carlson, Robert Mehlman, R. Roos-Serote, Maarten TI Non-LTE infrared observations at Venus: From NIMS/Galileo to VIRTIS/Venus express SO PLANETARY AND SPACE SCIENCE LA English DT Article DE non-LTE; Venus atmosphere; planetary remote sounding; radiative transfer; Venus express; VIRTIS; NIMS; Galileo ID RADIATIVE-TRANSFER MODEL; NATURAL LASER-EMISSION; CARBON-MONOXIDE; VIBRATIONAL LEVELS; MU-M; ATMOSPHERE; MARS; GALILEO; SPECTROMETER; POPULATIONS AB Recent improvements in a comprehensive non-local thermodynamic equilibrium (non-LTE) model Of CO2 atmospheres has permitted a better understanding of a number of Venusian atmospheric measurements taken more than a decade ago by the "Near Infrared Mapping Spectrometer" (NIMS) on board the Galileo spacecraft during its Venus fly-by. Those data, containing a strong non-LTE component, showed a structure in the 4.3-mu m spectral region which was challenging for non-LTE models so far. The model used in this work was refined after analysis of Martian CO2 atmospheric emission taken by the "Planetary Fourier Spectrometer" (PFS) and the "Visible and Infrared Mineralogical Mapping Spectrometer" (OMEGA) instruments on board Mars Express. Here we show that both the limb and the nadir measurements of the Venus daylight atmosphere taken at 4.3-mu m by NIMS can be fitted reasonably well with the revised model. This gives confidence in the usage of such model for the analysis of the Venus Express mission, in particular for the "Visible Infrared Thermal Imaging Spectrometer" (VIRTIS) instrument which will systematically observe these emissions. We present here non-LTE simulations for VIRTIS which demonstrate its capabilities and potential for detecting atmospheric emissions of CO and CO2 under non-LTE, both in limb and nadir observations and we discuss briefly the perspectives to use them in order to improve our understanding of the physics of the upper atmosphere of Venus. (C) 2007 Elsevier Ltd. All rights reserved. C1 CSIC, Granada, Spain. Observ Paris, LESIA, F-92195 Meudon, France. CALTECH, Jet Prop Lab, NASA5, Pasadena, CA USA. Univ Calif Los Angeles, Inst Geophys, Los Angeles, CA 90024 USA. Astron Observ, Lisbon, Portugal. RP Lopez-Valverde, MA (reprint author), CSIC, Apdo 3004, Granada, Spain. EM valverde@iaa.es OI Lopez-Valverde, M. A./0000-0002-7989-4267 NR 29 TC 21 Z9 21 U1 1 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 OCT PY 2007 VL 55 IS 12 BP 1757 EP 1771 DI 10.1016/j.pss.2007.01.008 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 227CX UT WOS:000250635900009 ER PT J AU Davarian, F AF Davarian, Faramaz TI Technical advances in deep-space communications and tracking SO PROCEEDINGS OF THE IEEE LA English DT Editorial Material C1 Jet Propuls Lab, Pasadena, CA 91109 USA. RP Davarian, F (reprint author), Jet Propuls Lab, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 1898 EP 1901 DI 10.1109/JPROC.2007.905981 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200002 ER PT J AU Cesarone, RJ Abraham, DS Deutsch, LJ AF Cesarone, Robert J. Abraham, Douglas S. Deutsch, Leslie J. TI Prospects for a next-generation deep-space network SO PROCEEDINGS OF THE IEEE LA English DT Article DE antenna arrays; antennas; architecture; communication systems; microwave amplifiers; networks; optical communication; radio navigation; radio receivers; radio transmitters; relays; satellite antennas; space vehicle communication; space vehicle tracking AB A next-generation deep-space network is currently under consideration by the National Aeronautics and Space Administration. Building upon its many past successes, this network will be required to meet the needs of current and planned missions. These will, no doubt, include the familiar suite of telemetry, command, tracking, and navigation services, with performance levels derived from analysis of the probable future mission set. Additionally, it will be expected to provide enabling capabilities for missions still on the drawing boards. Traditionally, the network serves the robotic deep-space exploration fleet. However, at this time, consideration of the special needs of planned future human lunar missions is appropriate, as well as the evolution to the eventual human exploration of mars. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cesarone, RJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM robert.j.cesarone@jpl.nasa.gov; douglas.s.abraham@jpl.nasa.gov; leslie.j.deutsch@jpl.nasa.gov NR 17 TC 16 Z9 21 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 1902 EP 1915 DI 10.1109/JPROC.2007.905043 PG 14 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200003 ER PT J AU Bagri, DS Statman, JI Gatti, MS AF Bagri, Durgadas S. Statman, Joseph I. Gatti, Mark S. TI Proposed array-based deep space network for NASA SO PROCEEDINGS OF THE IEEE LA English DT Article DE antennas; array; deep-space network; low cost; space communications; telemetry; tracking AB The current assets of the Deep Space Network (DSN) of the National Aeronautics and Space Administration (NASA), especially the 70-m antennas, are aging and becoming less reliable. Furthermore, they are expensive to operate and difficult to upgrade for operation at Ka-band (321 GHz).Replacing them with comparable monolithic large would be expensive. on the other hand, implementation of similar high-sensitivity assets can be achieved economically using an array-based architecture, where sensitivity is measured by G/T, the ratio of antenna gain to system temperature. An array-based architecture would also provide flexibility in operations and allow for easy addition of more G/T whenever required. Therefore, an array-based plan of the next-generation DSN for NASA has been proposed. The DSN array would provide more flexible downlink capability compared to the current DSN for robust telemetry, tracking and command services to the space missions of NASA and its international partners in a cost-effective way. instead of using the array as an element of the DSN and relying on the existing concept of operation, we explore a broader departure in establishing a more modern concept of operations to reduce the operations costs. This paper presents the array-based architecture for the next-generation DSN. It includes system block diagram, operations philosophy, user's view of operations, operations management, and logistics like maintenance philosophy and anomaly analysis and reporting. To develop the various required technologies and understand the logistics of building the array-based low-cost system, a breadboard array of three antennas has been built. This paper briefly describes the breadboard array system and its performance. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bagri, DS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Durgadas.S.Bagr@jpl.nasa.gov; Joseph.I.Statman@jpi.nasa.gov; Mark.S.Gatti@jpl.nasa.gov NR 9 TC 8 Z9 13 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 1916 EP 1922 DI 10.1109/JPROC.2007.905046 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200004 ER PT J AU Davarian, F AF Davarian, Faramaz TI Uplink Arrays for the deep space network SO PROCEEDINGS OF THE IEEE LA English DT Article DE deep-space antenna arraying; deep-space communications; high-power microwave transmission; uplink arrays AB Deep-space communication and navigation is faced with two challenges in the future: 1) the potential retirement of the largest antennas of NASA's Deep space Network and 2) an anticipated need for increasing ground system capacity so as to support higher data rates to and from missions operating at remote locations in the solar system, as well as in anticipation of a larger number of simultaneously flying missions. in the transmitting, or uplink, direction, one approach to increasing the effective transmitted power is to array multiple antennas. This is attractive mainly because it promises a lower construction cost than equivalent (large) single antenna systems. in addition, it has the potential for increasing the reliability of the uplink and reducing maintenance costs. This paper introduces the concept of uplink arraying by examining technological challenges and possible solutions to them. Arraying principles are presented and error sources described. The main challenge is to maintain carrier phase alignment among the antennas, and this must be done by periodic calibration. Presently, two calibration methods are being developed at the Jet Propulsion Laboratory as part of an uplink arraying demonstration effort. These methods are briefly discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Davarian, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Davarian@jpl.nasa.gov NR 15 TC 9 Z9 14 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 1923 EP 1930 DI 10.1109/JPROC.2007.905047 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200005 ER PT J AU Calhoun, M Huang, S Tjoelker, RL AF Calhoun, Malcolm Huang, Shouhua Tjoelker, Robert L. TI Stable photonic links for frequency and time transfer in the deep-space network and antenna arrays SO PROCEEDINGS OF THE IEEE LA English DT Article DE frequency stability; optical fiber applications; timing ID HIGH-STABILITY; FIBER NETWORK AB For more than two decades, NASA Deep Space Network (DSN) frequency and timing metrology has been a driving application for remote transfer of stable radio-frequency signals over fiber-optic cables. Precise, accurate, and stable signals are essential for deep-space communication and tracking, and syntonized and synchronized reference signals from atomic clocks calibrated to Coordinated Universal Time trust often be distributed over large distances. Fiber-optic technologies developed at the Jet Propulsion Laboratory have resulted in several operational signal transport capabilities that enable precise spacecraft navigation and sensitive radio science experiments. These techniques are now finding further applicability in metrology applications to remotely compare ultra stable microwave and optical atomic clocks and for antenna array x- and Ka-band signal transport applications where temporal phase stability and alignment are critical. The pioneering DSN photonic link developments and capabilities are summarized, and a stabilized multiphotonic link architecture for ultrastable signal transport in antenna arrays is described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Calhoun, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Malcolm.Calhoun@jpl.nasa.gov; Shouhua.Huang@jpl.nasa.gov; Robert.Tjoelker@jpl.nasa.gov NR 34 TC 47 Z9 51 U1 0 U2 13 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 1931 EP 1946 DI 10.1109/JPROC.2007.905048 PG 16 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200006 ER PT J AU Vodonos, YI Conroy, BL Losh, DL Silva, A AF Vodonos, Yakov I. Conroy, Bruce L. Losh, David L. Silva, Arnold TI Advances in ground transmitters, for the NASA deep space network SO PROCEEDINGS OF THE IEEE LA English DT Article DE ground support; microwave; space vehicle communication; transmitter AB The Deep Space Network (DSN), managed by the Jet Propulsion Laboratory for NASA, is equipped with multiple microwave transmitters ranging in average radiated power from 200 W to 400 kW. The transmitters are used for routine or emergency communication with spacecraft, for navigation, and for radio science tasks. The latest advances in transmitter engineering were implemented in a new generation of 20-kW dual-band transmitters developed for the DSN 34-m beam waveguide antennas. innovations include additional X-band communication capability for near Earth missions, new control algorithms, automated calibration, improved and expanded computerized monitoring and diagnostics, reduced cabling, and improved maintainability. The innovations were very beneficial for the DSN "overload" during the Mars 2003/2004 missions and will benefit other missions throughout the next decade. This paper describes the current design of the new transmitters and possible future developments. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Vodonos, YI (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Yakov.I.vodonos@jpl.nasa.gov; Bruce.L.Conroy@jpl.nasa.gov; David.L.Losh@jpl.nasa.gov; Arnold.Silva@jpl.nasa.gov NR 3 TC 1 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 1947 EP 1957 DI 10.1109/JPROC.2007.905050 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200007 ER PT J AU Wilson, JD Wintucky, EG Vaden, KR Force, DA Krainsky, IL Simons, RN Robbins, NR Menninger, WL Dibb, DR Lewis, DE AF Wilson, Jeffrey D. Wintucky, Edwin G. Vaden, Karl R. Force, Dale A. Krainsky, Isay L. Simons, Rainee N. Robbins, Neal R. Menninger, William L. Dibb, Daniel R. Lewis, David E. TI Advances in space traveling-wave tubes for NASA missions SO PROCEEDINGS OF THE IEEE LA English DT Article DE amplifiers; cathodes; microwaves; space communications; traveling-wave tubes ID MULTISTAGE DEPRESSED COLLECTORS; COLD-TEST CHARACTERISTICS; TWT; EFFICIENCY; MODEL; RF; CATHODE; DESIGN; POWER; BAND AB Significant advances in the performance and reliability of traveling-wave tubes (TWTs) utilized in amplifying space communication signals for NASA missions have been achieved over the last three decades through collaborative efforts between NASA and primarily L-3 Communications Electron Technologies, Inc. (L-3 ETI). This paper summarizes some of the key milestones during this period and includes development of TWTS for the communications Technology Satellite, Cassini, and Lunar Reconnaissance orbiter missions. Technical advances in computer modeling, design techniques, materials, and fabrication have enabled power efficiency to increase by almost 40% and the output power/mass figure-of-merit to increase by an order of magnitude during this period. C1 NASA, Glenn Res Ctr, Elect & Opt Dev Technol Branch, Cleveland, OH 44135 USA. L 3 Commun Elect Technol Inc, Torrance, CA 90509 USA. RP Wilson, JD (reprint author), NASA, Glenn Res Ctr, Elect & Opt Dev Technol Branch, Cleveland, OH 44135 USA. EM Jeffrey.D.Wilson@nasa.gov; Edwin.G.Wintucky@nasa.gov; Karl.R.Vaden@na5a.gov; Dale.A.Force@nasa.gov; Isay.L.Krainsky@nasa.gov; Rainee.N.Simons@nasa.gov; Neal.Robbins@L3-com.com; william.L.Menninger@L3-com.com; Daniel.R.Dibb@L3-com.com; Dave.E.Lewis@L3-com.com NR 81 TC 13 Z9 13 U1 1 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 1958 EP 1967 DI 10.1109/JPROC.2007.905062 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200008 ER PT J AU Romanofsky, RR AF Romanofsky, Robert R. TI Advances in scanning reflectarray antennas based on ferroelectric thin-film phase shifters for deep-space communications SO PROCEEDINGS OF THE IEEE LA English DT Article DE ferroelectric phase shifters; intersymbol interference; radiation effects; reflectarray antenna ID ARRAY AB Though there are a few examples of scanning phased array antennas that have flown successfully in space, the quest for "low cost" high-efficiency large-aperture microwave phased arrays continues. Fixed and mobile applications that may be part of a heterogeneous exploration communication architecture will benefit from the agile (rapid) beam steering and graceful degradation afforded by phased array antennas. The reflectarray promises greater efficiency and economy compared to directly radiating varieties. Implementing a practical scanning version has proven elusive. The ferroelectric reflectarray, under development and described herein, involves phase shifters based on coupled microstrip patterned on BaxSr1-x TiO3 films that were laser ablated onto LaAlO3 substrates. These devices outperform their semiconductor counterparts from X- through and K-band frequencies. There are special issues associated with the implementation of a scanning reflectarray antenna, especially one realized with thin-film ferroelectric phase shifters. This paper will discuss these issues, which include relevance of phase shifter loss; modulo 2 pi effects and phase shifter transient effects on bit error rate; scattering from the ground plane; presentation of a novel hybrid ferroelectric-semiconductor phase shifter; and the effect of mild radiation exposure on phase shifter performance. C1 NASA, Glenn Res Ctr, Microwave & Opt Syst Branch, Cleveland, OH 44135 USA. RP Romanofsky, RR (reprint author), NASA, Glenn Res Ctr, Microwave & Opt Syst Branch, Cleveland, OH 44135 USA. EM robert.r.romanofsky@nasa.gov NR 21 TC 25 Z9 25 U1 3 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 1968 EP 1975 DI 10.1109/JPROC.2007.905065 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200009 ER PT J AU Reinhart, RC Johnson, SK Kacpura, TJ Hall, CS Smith, CR Liebetreu, J AF Reinhart, Richard C. Johnson, Sandra K. Kacpura, Thomas J. Hall, Charles S. Smith, Carl R. Liebetreu, John TI Open architecture standard for NASA's software-defined space telecommunications radio systems SO PROCEEDINGS OF THE IEEE LA English DT Article DE application programming interface; architecture; software-defined radio; space communications; transceiver AB NASA is developing an architecture standard for software-defined radios used in space- and ground-based platforms to enable commonality among radio developments to enhance capability and services while reducing mission,and programmatic risk. Transceivers (or transponders) with functionality primarily defined in software (e.g., firmware) have the ability to change their functional behavior through software alone. This radio architecture standard offers value by employing common waveform software interfaces, method of instantiation, operation, and testing among different compliant hardware and software products. These common interfaces within the architecture abstract application software from the underlying hardware to enable technology insertion independently at either the software or hardware layer. This paper presents the initial Space Telecommunications Radio System architecture for NASA missions to provide the desired software abstraction and flexibility while minimizing the resources necessary to support the architecture. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. ASRC Analex Corp, Cleveland, OH 44135 USA. Gen Dynam Adv Informat Syst, Scottsdale, AZ 85252 USA. RP Reinhart, RC (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM richard.c.reinhart@nasa.gov; sandra.k.johnson@nasa.gov; thomas.j.kacpura@nasa.gov; Steve.hall@nasa.gov; Carl.smith@gd-ais.com; John.liebetreu@gd-ais.com NR 18 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 1986 EP 1993 DI 10.1109/JPROC.2007.905071 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200011 ER PT J AU Kuhn, W Lay, NE Grigorian, E Nobbe, D Kuperman, I Jeon, J Wong, K Tugnawat, Y He, X AF Kuhn, William Lay, Norman E. Grigorian, Edwin Nobbe, Dan Kuperman, Igor Jeon, Jeongmin Wong, Kai Tugnawat, Yogesh He, Xin TI A microtransceiver for UHF proximity links including Mars surface-to-orbit applications SO PROCEEDINGS OF THE IEEE LA English DT Article DE CMOS analog integrated circuits; CMOS integrated circuits; cryogenic electronics; digital radio; filters; integrated circuit design; integrated circuit noise; integrated circuits; integrated circuit testing; oscillator stability; space vehicle communication; space vehicle electronics; space vehicle telemetry; switching circuits; ultra-high-frequency (UHF) receivers; UHF transmitters ID DIGITAL CMOS PROCESS; SPIRAL INDUCTORS; POWER-AMPLIFIER; TRANSCEIVER; ARCHITECTURE AB A low-volume low-mass low-power ultra-high-frequency radio transceiver for future planetary missions is described. The project targets a volume of less than 10 cm(3), mass of less than 50 grams, and power consumption of 50 mW on receive and 100 mW, 300 mW, or 3 W on transmit (for 10 mW, 100 mW, and I W output options). The transmitter design supports convolutionally coded binary phase-shift keying (BPSK), RC-BPSK, and quadrature phase-shift keying transmission from 1 to 256 kbps. Command/control instructions can be received at 2 or 8 kbps, with a sensitivity of better than -120 dBM. in addition to its low volume/mass/ power features, temperature compensation to -100 degrees C and radiation tolerance to 100 krad allow operation outside of thermally controlled, shielded enclosures, further reducing the mass and complexity of exploration vehicles. The design is described in a top-down format, beginning with system requirements and proceeding through digital modem algorithm development, discussion of the silicon-on-sapphire CMOS process used and elaboration of key blocks in the radio-frequency (RF) integrated circuit design. Techniques to address coupling between high-sensitivity RF and on-chip digital circuits are also presented, and test results are given for prototypes of all major functions. Although designed for the Martian environment, the transceiver is expected to be useful in other proximity links where a small low-power radio compatible with Prox-1 space-link protocols is desired. C1 Kansas State Univ, Manhattan, KS 66506 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Peregrine Semicond Corp, Palatine, IL 60067 USA. Gen Dynam C4 Syst, Scottsdale, AZ 85257 USA. NXP Semicond, NL-5656 AE Eindhoven, Netherlands. RP Kuhn, W (reprint author), Kansas State Univ, Manhattan, KS 66506 USA. EM wkuhn@ksu.edu; norman.lay@jpl.nasa.gov; edwin.grigorian@jpl.nasa.gov; dnobbe@psemi.com; igor.kuperman@jpI.nasa.gov; jmj3663@ksu.edu; Kai.Wong@gdc4s.com; Yogesh.X.Tugnawat@sprint.com; xin.he@nxp.com NR 33 TC 8 Z9 8 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 2019 EP 2044 DI 10.1109/JPROC.2007.905092 PG 26 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200014 ER PT J AU Biswas, A Moision, B Roberts, WT Farr, WH Gray, A Quirk, K Hamkins, J Cheng, MK Gin, J Nakashima, M Ortiz, GG Piazzolla, S Liebe, CC Losh, DL AF Biswas, Abhijit Moision, Bruce Roberts, William T. Farr, William H. Gray, Andrew Quirk, Kevin Hamkins, Jon Cheng, Michael K. Gin, Jonathan Nakashima, Michael Ortiz, Gerardo G. Piazzolla, Sabino Liebe, Carl Christian Losh, David L. TI Palomar receive terminal (PRT) for the Mars laser communication demonstration (MLCD) project SO PROCEEDINGS OF THE IEEE LA English DT Article DE deep space; laser communication; photon counting; pulse-position modulation ID SYSTEM; CHANNEL; CODES AB Significant technological advances were made toward utilizing the Hale telescope for receiving the faint laser communication signals transmitted from an optical transceiver on a spacecraft orbiting Mars. The so-called Palomar Receive Terminal design, which would have supported nominal downlink data rates of 1-30 Mbps, is described. Testing to validate technologies for near-Sun (3 degrees from edge of solar disc) daytime operations is also discussed. Finally, a laboratory end-to-end link utilizing a 64-ary pulse-position modulated photon-counting receiver and decoder that achieved predicted near-capacity (within 1.4 dB) performance is described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Biswas, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Abhijit.Biswas@jpl.nasa.gov; Bruce.E.Moision@jpl.nasa.gov; William.T.Roberts@jpl.nasa.gov; william.H.Farr@jpl.nasa.gov; Andrew.A.Gray@jpl.nasa.gov; Kevin.J.Quirk@jpl.nasa.gov; Jon.Hamkins@jpl.nasa.gov; michael.K.Cheng@jpl.nasa.gov; Jonathan.W.Gin@jpl.nasa.gov; Michael.A.Nakashima@jpl.nasa.gov; Gerardo.G.Ortiz@jpl.nasa.gov; Sabino.Piazzolla@jpl.nasa.gov; Carl.C.Liebe@jpl.nasa.gov; David.L.Losh@jpl.nasa.gov NR 37 TC 5 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 2045 EP 2058 DI 10.1109/JPROC.2007.905054 PG 14 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200015 ER PT J AU Hemmati, H Biswas, A Boroson, DM AF Hemmati, Hamid Biswas, Abhijit Boroson, Don M. TI Prospects for improvement of interplanetary laser communication data rates by 30 dB SO PROCEEDINGS OF THE IEEE LA English DT Article DE laser communications; optical communications; planetary communications ID EFFICIENCY; DETECTOR AB NASA's Mars Laser Communications Demonstration (MLCD) project (since discontinued) was designed to achieve data rates greater than 1 Mb/s from the farthest Mars range and greater than 30-Mb/s from the nearest Mars range. We present here pathways whereby ongoing optical technology advances should allow 30 dB of increased data rates relative to MLCD by 2020. In other words, technical advances should soon allow the return of deep-space data at rates of 1 Gb/s from the maximum Mars range, 100 Mb/s from Jupiter distances, and 10 Mb/s from Uranus, all many orders of magnitude greater than present radio-frequency capabilities. The potential for realizing the stated capability with less than a three times increase. in dc power required from the spacecraft and no increase in payload mass is discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. MIT, Lincoln Lab, Lexington, MA 02420 USA. RP Hemmati, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM hhemmati@jpl.nasa.gov; abiswas@jpl.nasa.gov; boroson@ll.mit.edu NR 41 TC 12 Z9 13 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD OCT PY 2007 VL 95 IS 10 BP 2082 EP 2092 DI 10.1109/JPROC.2007.905057 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA 235IX UT WOS:000251228200018 ER PT J AU Bar-Cohen, Y AF Bar-Cohen, Y. TI Artificial muscles based on electroactive polymers as an enabling tool in biomimetics SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE LA English DT Article DE electroactive polymers; artificial muscles; biomimetics; robotics; biologically inspired technologies AB Evolution has resolved many of nature's challenges leading to working and lasting solutions that employ principles of physics, chemistry, mechanical engineering, materials science, and many other fields of science and engineering. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems, and many other benefits. Some of the technologies that have emerged include artificial intelligence, artificial vision, and artificial muscles, where the latter is the moniker for electroactive polymers (EAPs). To take advantage of these materials and make them practical actuators, efforts are made worldwide to develop capabilities that are critical to the field infrastructure. Researchers are developing analytical model and comprehensive understanding of EAP materials response mechanism as well as effective processing and characterization techniques. The field is still in its emerging state and robust materials are still not readily available; however, in recent years, significant progress has been made and commercial products have already started to appear. In the current paper, the state-of-the-art and challenges to artificial muscles as well as their potential application to biomimetic mechanisms and devices are described and discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 67-119, Pasadena, CA 91109 USA. EM yosi@jpl.nasa.gov NR 11 TC 5 Z9 6 U1 3 U2 22 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI WESTMINISTER PA 1 BIRDCAGE WALK, WESTMINISTER SW1H 9JJ, ENGLAND SN 0954-4062 J9 P I MECH ENG C-J MEC JI Proc. Inst. Mech. Eng. Part C-J. Eng. Mech. Eng. Sci. PD OCT PY 2007 VL 221 IS 10 BP 1149 EP 1156 DI 10.1243/09544062JMES510 PG 8 WC Engineering, Mechanical SC Engineering GA 226OC UT WOS:000250597400003 ER PT J AU Eckermann, SD Ma, J Wu, DL Broutman, D AF Eckermann, Stephen D. Ma, Jun Wu, Dong L. Broutman, Dave TI A three-dimensional mountain wave imaged in satellite radiance throughout the stratosphere: Evidence of the effects of directional wind shear SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE radiance imagery; AMSU-A; AIRS; directional wind shear; asymptotic wake ID AMSU-A RADIANCES; SOLVE/THESEO 2000 CAMPAIGN; ATMOSPHERIC GRAVITY-WAVES; RADIATIVE-TRANSFER MODEL; OFFICE UNIFIED MODEL; MIDDLE ATMOSPHERE; NUMERICAL SIMULATIONS; DRAG PARAMETRIZATION; ARCTIC STRATOSPHERE; GENERAL-CIRCULATION AB Swath-scanned thermal radiances from the Advanced Microwave Sounding Units (AMSU-A) on the NOAA and Aqua satellites are used to image the horizontal temperature structure of a long-wavelength mountain wave that formed over southern Scandinavia on 14 January 2003. Data from all six stratospheric channels show this wave propagating through the full depth of the stratosphere. In channels 9-11 (attitudes similar to 20-90 hPa) the imaged wave has a phase structure broadly consistent with a stationary wave radiated by the southeastward flow over and above the quasi-elliptical terrain of southern Norway. Channel 12 radiances at similar to 10 hPa, however, show a remarkable abrupt change in imaged wave structure: the horizontal wavelength contracts, phase lines rotate anticlockwise by 30 degrees-40 degrees, and peak activity migrates to the south to lie over Denmark and northern Germany. Similar structure persists in channels 13 and 14 (at similar to 2-5 hPa) with progessively increasing radiance amplitudes. These features are stable over the similar to 10 hours of AMSU-A measurements from five separate overpasses, and are validated against independent radiances acquired by the Atmospheric Infrared Sounder (AIRS) and retrieved AIRS/AMSU-A temperature profiles from the Aqua overpass. This change at the channel 11/12 interface coincides with an onset of anticlockwise rotation (backing) and intensification of background stratospheric winds with height. Fourier-ray and spatial ray modelling incorporating these directionally sheared winds and simplified orographic forcing reproduce the salient features of the observations, but only after wave-induced temperature perturbations have been converted to channel radiances using a forward model. The differential visibility of various components of this three-dimensional mountain wave to the AMSU-A channel weighting functions has a first-order impact on the observations at heights above 10 hPa. Once that is factored in, the combined observations and modelling provide direct experimental support for the Shutts model's predictions of how backing wind vectors affect the vertical evolution of three-dimensional mountain waves. Implications of these observations for orographic gravity wave drag parametrization are briefly discussed. Copyright (c) 2007 Royal Meteorological Society. C1 [Eckermann, Stephen D.] USN, Res Lab, Space Sci Div, Washington, DC 20375 USA. [Ma, Jun; Broutman, Dave] Computat Phys Inc, Springfield, VA USA. [Wu, Dong L.] CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Eckermann, SD (reprint author), USN, Res Lab, Space Sci Div, 4555 Overlook Ave SW, Washington, DC 20375 USA. EM stephen.eckermann@nrl.navy.mil RI Wu, Dong/D-5375-2012 NR 79 TC 21 Z9 21 U1 2 U2 6 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9009 EI 1477-870X J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD OCT PY 2007 VL 133 IS 629 BP 1959 EP 1975 DI 10.1002/qj.187 PN B PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 255BP UT WOS:000252632000005 ER PT J AU Zhou, D Semones, E Weyland, M Benton, ER AF Zhou, D. Semones, E. Weyland, M. Benton, E. R. TI LET calibration for CR-39 detectors in different oxygen environments SO RADIATION MEASUREMENTS LA English DT Article DE CR-39; LET calibration; LET spectrum; radiation measurement ID LOW-EARTH-ORBIT; NUCLEAR TRACK DETECTORS; COSMIC-RAYS; AVIATION ALTITUDES; RADIATION-FIELD; ETCH AB High LET (linear energy transfer) radiation is the main contributor to the radiation field in low Earth orbit (LEO) in terms of dose equivalent. CR-39 plastic nuclear track detectors (PNTDs) can measure the LET spectrum and charge spectrum for the complicated radiation field in space. Previous research indicated that the sensitivity of CR-39 is different for CR-39 PNTDs working in different oxygen environments. LET calibration for CR-39 detectors in different oxygen environments is needed. Almost all the previous LET calibration work was carried out for CR-39 detectors in good-oxygen condition, LET calibration work for CR-39 in poor-oxygen condition has not been conducted until our work. Systematic LET calibrations were carried out by JSC-SRAG (Space Radiation Analysis Group) for CR-39 detectors working in different oxygen environments and abundant results of LET calibrations were obtained. This paper introduces the method for CR-39 LET calibration, presents and discusses the calibration results and some applications. Published by Elsevier Ltd. C1 [Zhou, D.; Semones, E.; Weyland, M.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Zhou, D.] Univ Space Res Assoc, Houston, TX 77058 USA. [Benton, E. R.] Eril Res Inc, Stillwater, OK 74074 USA. RP Zhou, D (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 Nasa Rd 1, Houston, TX 77058 USA. EM dzhou@ems.jsc.nasa.gov NR 22 TC 12 Z9 13 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD OCT PY 2007 VL 42 IS 9 BP 1499 EP 1506 DI 10.1016/j.radmeas.2007.08.001 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 242IH UT WOS:000251718300010 ER PT J AU Martin, AK Koelfgen, SJ AF Martin, Adam K. Koelfgen, Syri J. TI A maximum-likelihood algorithm for reduction of Langmuir probe data SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID TRIPLE PROBE AB The reduction of Langmuir triple and quadruple probe data, i.e., the determination of the electron temperature T-e from the measured voltages and currents, requires the solution of an implicit transcendental equation in Te, at every point in time. Random errors and noise in the measurements occasionally precludes solution of the equation, resulting in an indeterminate temperature at those times. We present a method for overcoming this problem that uses the method of maximum likelihood. The experimental uncertainties, assumed to be normally distributed, are used in solving the implicit equation in Te. At every point in time, a likelihood function is calculated, and the temperature which maximizes this function is taken to be the solution Te. The uncertainty in the resulting measurement is taken to be the width of the likelihood function. Examples of this technique are shown. (C) 2007 American Institute of Physics. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NASA Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. RP Martin, AK (reprint author), NASA, George C Marshall Space Flight Ctr, ER24, Huntsville, AL 35812 USA. EM adam.k.martin@nasa.gov NR 17 TC 0 Z9 0 U1 1 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 2007 VL 78 IS 10 AR 103508 DI 10.1063/1.2801010 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 226LE UT WOS:000250589800021 PM 17979420 ER PT J AU Mather, JC AF Mather, John C. TI Nobel lecture: From the big bang to the nobel prize and beyond SO REVIEWS OF MODERN PHYSICS LA English DT Article ID BACKGROUND EXPERIMENT SEARCH; COBE FIRAS INSTRUMENT; SPECTRUM; RADIATION; SUBMILLIMETER; UNIVERSE; MODEL; FLUCTUATIONS; SEPARATION; ANISOTROPY AB NASA's Cosmic Background Explorer satellite mission, the COBE, laid the foundations for modern cosmology by measuring the spectrum and anisotropy of the cosmic microwave background radiation and discovering the cosmic infrared background radiation. I describe the history of the COBE project, its scientific context, the people who built it, and the scientific results. The COBE observed the universe on the largest scales possible by mapping the cosmic microwave and infrared background radiation fields and determining their spectra. It produced conclusive evidence that the hot Big Bang theory of the early universe is correct, showed that the early universe was very uniform but not perfectly so, and that the total luminosity of post-Big Bang objects is twice as great as previously believed. The COBE concept was developed by a Mission Definition Study Team appointed by NASA in 1976, based on three competing proposals submitted in 1974. The COBE was built in-house by Goddard Space Flight Center, with a helium cryostat provided by Ball Aerospace, and was launched on a Delta rocket built by McDonnell Douglas. It is in a circular orbit 900 km above the Earth, in a plane inclined 99 degrees to the equator and roughly perpendicular to the line to the Sun. It carried three instruments, a far infrared absolute spectrophotometer (FIRAS), a differential microwave radiometer with three channels (DMR), and a diffuse infrared background experiment (DIRBE). The helium cryostat cooled the FIRAS and DIRBE for 10 months until the helium was exhausted, but operations continued for a total of 4 years. Subsequent observations have confirmed the COBE results and led to measurements of the main cosmological parameters with a precision of a few percent. C1 NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. RP Mather, JC (reprint author), NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Mail Code 665, Greenbelt, MD 20771 USA. EM john.c.mather@nasa.gov NR 47 TC 8 Z9 8 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD OCT-DEC PY 2007 VL 79 IS 4 BP 1331 EP 1348 DI 10.1103/RevModPhys.79.1331 PG 18 WC Physics, Multidisciplinary SC Physics GA 233RK UT WOS:000251107800006 ER PT J AU Konovalenko, AA Stanislavsky, AA Abranin, EP Dorovsky, VV Mel'nik, VN Kaiser, ML Lecacheux, A Rucker, HO AF Konovalenko, A. A. Stanislavsky, A. A. Abranin, E. P. Dorovsky, V. V. Mel'nik, V. N. Kaiser, M. L. Lecacheux, A. Rucker, H. O. TI Absorption in burst emission SO SOLAR PHYSICS LA English DT Article DE sun : corona; sun : shock waves; sun : radio radiation ID SOLAR RADIO-BURSTS; FLARE; FREQUENCIES; TURBULENCE; CONTINUUM; ONSET; SUN; MHZ AB Here we report a radio burst in absorption at 9-30 MHz observed with the UTR-2 telescope. This event occurred on 19 August 2003 about 11:16-11:26 UT, against solar type IV/II emission background. It is the first event where absorption was observed below 30 MHz. The absorption region, comparable with the solar radius size, traveled a long distance into the upper corona from the Sun. We show that the burst minimum corresponds to the almost full absorption of the solar radio emission up to a background level of the quiescent Sun. This supports the interpretation of the phenomenon as an absorption. The result is examined independently with the Nancay Decameter Array measurements and the Wind WAVES instrument records. C1 Inst Radio Astron, UA-61002 Kharkov, Ukraine. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Observ Paris, CNRS, Dept Radioastron, UMR 8644, F-75014 Paris, France. Austrian Acad Sci, Space Res Inst, A-8042 Graz, Austria. RP Stanislavsky, AA (reprint author), Inst Radio Astron, 4 Chervonopraporna St, UA-61002 Kharkov, Ukraine. EM akonov@ira.kharkov.ua; alexstan@ira.kharkov.ua RI Stanislavsky, Aleksander/C-5435-2015 OI Stanislavsky, Aleksander/0000-0003-4420-047X NR 23 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD OCT PY 2007 VL 245 IS 2 BP 345 EP 354 DI 10.1007/s11207-007-9049-8 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 239AQ UT WOS:000251490400009 ER PT J AU Litvak, ML Mitrofanov, IG Kozyrev, AS Sanin, AB Tret'yakov, VI Boynton, WV Hamara, D Saunders, S AF Litvak, M. L. Mitrofanov, I. G. Kozyrev, A. S. Sanin, A. B. Tret'yakov, V. I. Boynton, W. V. Hamara, D. Saunders, S. TI Long-term observations of the evolution of the southern seasonal cap of Mars: Neutron measurements by the HEND instrument onboard the 2001 Mars Odyssey spacecraft SO SOLAR SYSTEM RESEARCH LA English DT Article DE 96; 12; Qr; 29; 30; Hs ID WATER-ICE; NEAR-SURFACE; SUMMER TEMPERATURES; GLOBAL DISTRIBUTION; HEND/ODYSSEY DATA; SNOW DEPTH; HYDROGEN; DETECTOR; REGIONS; POLE AB We present the results of five-year observations of the southern seasonal cap of Mars based on neutron spectroscopy of the surface fulfilled by the Russian HEND instrument onboard the NASA 2001 Mars Odyssey spacecraft. The numerical modeling of the observational data allowed us to reconstruct the curves of the variations of the total mass of the southern seasonal cap of Mars for different years (three Martian years) and to find the year-to-year variations of the seasonal cycle. C1 Russian Acad Sci, Space Res Inst, Moscow 117997, Russia. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. RP Litvak, ML (reprint author), Russian Acad Sci, Space Res Inst, Profsoyuznaya 84-32, Moscow 117997, Russia. NR 34 TC 1 Z9 1 U1 0 U2 3 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0038-0946 EI 1608-3423 J9 SOLAR SYST RES+ JI Solar Syst. Res. PD OCT PY 2007 VL 41 IS 5 BP 385 EP 394 DI 10.1134/S0038094607050024 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 221QZ UT WOS:000250243700002 ER PT J AU Fujimoto, M Baumjohann, W Kabin, K Nakamura, R Slavin, JA Terada, N Zelenyi, L AF Fujimoto, M. Baumjohann, W. Kabin, K. Nakamura, R. Slavin, J. A. Terada, N. Zelenyi, L. TI Hermean magnetosphere-solar wind interaction SO SPACE SCIENCE REVIEWS LA English DT Review DE Mercury; magnetosphere; substorm; solar wind ID INTERPLANETARY MAGNETIC-FIELD; KELVIN-HELMHOLTZ INSTABILITY; ION LARMOR RADIUS; MERCURYS MAGNETOSPHERE; CHARGED-PARTICLES; PLANET MERCURY; MAGNETOTAIL; ATMOSPHERE; ACCELERATION; MAGNETOPAUSE AB The small intrinsic magnetic field of Mercury together with its proximity to the Sun makes the Hermean magnetosphere unique in the context of comparative magnetosphere study. The basic framework of the Hermean magnetosphere is believed to be the same as that of Earth. However, there exist various differences which cause new and exciting effects not present at Earth to appear. These new effects may force a substantial correction of our naive predictions concerning the magnetosphere of Mercury. Here, we outline the predictions based on our experience at Earth and what effects can drastically change this picture. The basic structure of the magnetosphere is likely to be understood by scaling the Earth's case but its dynamic aspect is likely modified significantly by the smallness of the Hermean magnetosphere and the substantial presence of heavy ions coming from the planet's surface. C1 [Baumjohann, W.; Nakamura, R.] Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria. [Fujimoto, M.] Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. [Kabin, K.] Univ Alberta, Edmonton, AB, Canada. [Slavin, J. A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Terada, N.] NiCT, Koganei, Tokyo, Japan. [Zelenyi, L.] Russian Acad Sci, Inst Space Res, Moscow V71, Russia. RP Baumjohann, W (reprint author), Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria. EM baumjohann@oeaw.ac.at RI Baumjohann, Wolfgang/A-1012-2010; Slavin, James/H-3170-2012; Nakamura, Rumi/I-7712-2013 OI Baumjohann, Wolfgang/0000-0001-6271-0110; Slavin, James/0000-0002-9206-724X; Nakamura, Rumi/0000-0002-2620-9211 NR 90 TC 32 Z9 32 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PD OCT PY 2007 VL 132 IS 2-4 BP 529 EP 550 DI 10.1007/s11214-007-9245-8 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 246GT UT WOS:000251996200012 ER PT J AU Orsini, S Blomberg, LG Delcourt, D Grard, R Massetti, S Seki, K Slavin, J AF Orsini, S. Blomberg, L. G. Delcourt, D. Grard, R. Massetti, S. Seki, K. Slavin, J. TI Magnetosphere-exosphere-surface coupling at Mercury SO SPACE SCIENCE REVIEWS LA English DT Review DE planets and satellites : Mercury; planetary environments; planetary magnetospheres plasmas; solarplanetary relatioships; interplanetary medium ID FIELD-ALIGNED CURRENTS; SUBSTORM CURRENT WEDGE; MAGNETIC-FIELD; SOLAR-WIND; MAGNETOPAUSE RECONNECTION; EARTHS MAGNETOSPHERE; ENERGETIC PARTICLES; SODIUM EXOSPHERE; ION-ACCELERATION; RING CURRENT AB Mercury's environment is a complex system, resulting from the interaction between the solar wind, magnetosphere, exosphere and surface. A comprehensive description of its characteristics requires a detailed study of these four elements. This paper illustrates and discusses the key processes that are implicated in the strong coupling of the Hermean magnetosphere with the other elements. The magnetosphere of Mercury, frequently called "mini- magnetosphere", when compared to that of Earth, plays a significant role in controlling the planet source and loss processes, by means of both particle and field interactions. We review the status of our knowledge, and give possible interpretations of the still-limited data set presently available. C1 [Orsini, S.; Massetti, S.] IFSI, INAF, I-00133 Rome, Italy. [Blomberg, L. G.] Royal Inst Technol, Sch Elect Engn, S-10044 Stockholm, Sweden. [Delcourt, D.] IPSL, CNRS, CETP, St Maur des Fosses, France. [Grard, R.] European Space Agcy, Estec, Res & Sci Support Dept, Noordwijk, Netherlands. [Seki, K.] Nagoya Univ, Solar Terr Environm Lab, Chikusa Ku, Nagoya, Aichi 4648601, Japan. [Slavin, J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Orsini, S (reprint author), IFSI, INAF, Via Fosso Cavaliere 100, I-00133 Rome, Italy. EM stefano.orsini@ifsi-roma.inaf.it RI Slavin, James/H-3170-2012; OI Slavin, James/0000-0002-9206-724X; Massetti, Stefano/0000-0002-7767-1334 NR 99 TC 7 Z9 7 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PD OCT PY 2007 VL 132 IS 2-4 BP 551 EP 573 DI 10.1007/s11214-007-9222-2 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 246GT UT WOS:000251996200013 ER PT J AU Radil, K DellaCorte, C Zeszotek, M AF Radil, Kevin DellaCorte, Christopher Zeszotek, Michelle TI Thermal management techniques for oil-free turbomachinery systems SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Article DE foil air bearing; gas bearing; turbomachinery ID FOIL AIR BEARINGS; JOURNAL BEARINGS; PERFORMANCE AB Tests were performed to evaluate three different methods of utilizing air to provide thermal management control for compliant journal foil air bearings. The effectiveness of the methods was based on bearing bulk temperature and axial thermal gradient reductions during air delivery. The first method utilized direct impingement of air on the inner surface of a hollow test journal during operation. The second, less indirect method achieved heat removal by blowing air inside the test journal parallel to the shaft axis to simulate air flowing axially through a hollow shaft. The third method emulated the most common approach to removing heat by forcing air axially through the bearing's support structure. Internal bearing temperatures were measured with three, type K thermocouples embedded in the bearing that measured general internal temperatures and axial thermal gradients. Testing was performed in a 1 atm, 260 degrees C ambient environment with the bearing operating at 60 krpm and supporting a load of 222N. Air volumetric flows of 0.06, 0.11 and 0.17 m(3)/min at approximately 150 degrees C to 200 degrees C were used. The tests indicate that all three methods provide thermal management but at different levels of effectiveness. Axial cooling of the bearing support structure had a greater effect on bulk temperature for each air flow and demonstrated that the thermal gradients could be influenced by the directionality of the airflow. Direct air impingement on the journal's inside surface provided uniform reductions in both bulk temperature and thermal gradients. Similar to the direct method, indirect journal cooling had a uniform cooling effect on both bulk temperatures and thermal gradients but was the least effective of the three methods. C1 NASA, Glenn Res Ctr, Cleveland, OH USA. Purdue Univ, W Lafayette, IN 47907 USA. RP Radil, K (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. NR 20 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 OCT PY 2007 VL 63 IS 10 BP 42 EP 49 PG 8 WC Engineering, Mechanical SC Engineering GA 218NA UT WOS:000250021000014 ER PT J AU Radil, K DellaCorte, C Zeszotek, M AF Radil, Kevin DellaCorte, Christopher Zeszotek, Michelle TI Thermal management techniques for oil-free turbomachinery systems SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Editorial Material DE foil air bearing; gas bearing; turbomachinery C1 NASA, Glenn res Ctr, Cleveland, OH USA. Purdue Univ, W Lafayette, IN 47907 USA. RP Radil, K (reprint author), NASA, Glenn res Ctr, Cleveland, OH USA. 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 OCT PY 2007 VL 63 IS 10 BP 42 EP 42 PG 1 WC Engineering, Mechanical SC Engineering GA 218NA UT WOS:000250021000013 ER PT J AU Zaretsky, EV Lewicki, DG Savage, M Vlcek, BL AF Zaretsky, Erwin V. Lewicki, David G. Savage, Michael Vlcek, Brian L. TI Determination of turboprop reduction gearbox system fatigue life and reliability SO TRIBOLOGY TRANSACTIONS LA English DT Article DE gearbox life prediction; gearing; rolling-element bearings; Monte Carlo analysis; probabilistic life analysis; weibull; analysis AB Two computational models to determine the fatigue life and reliability of a commercial turboprop gearbox are compared with each other and with field data. These models are (1) Monte Carlo simulation of randomly selected lives of individual bearings and gears comprising the system and (2) two-parameter Weibull distribution function for bearings and gears comprising the system using strict-series system reliability to combine the calculated individual component lives in the gearbox. The Monte Carlo simulation included the virtual testing of 744,450 gearboxes. Two sets of field data were obtained from 64 gearboxes that were first-run to removal for cause, were refurbished and placed back in service, and then were second-run until removal for cause. A series of equations were empirically developed from the Monte Carlo simulation to determine the statistical variation in predicted life and Weibull slope as a function of the number of gearboxes failed. The resultant L-10 life from the field data was 5,627 h. From strict-series system reliability, the predicted L-10 life was 774 h. From the Monte Carlo simulation, the median value for the L-10 gearbox lives equaled 757 h. Half of the gearbox L-10 lives will be less than this value and the other half more. The resultant L-10 life of the second-run (refurbished) gearboxes was 1,334h. The apparent load-life exponent p for the roller bearings is 5.2. Were the bearing lives to be recalculated with a load-life exponent p equal to 5.2, the predicted L-10 life of the gearbox would be equal to the actual life obtained in the field. The component failure distribution of the gearbox from the Monte Carlo simulation was nearly identical to that using the strict-series system reliability analysis, proving the compatibility of these methods. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Akron, Akron, OH 44325 USA. Georgia So Univ, Statesboro, GA 30460 USA. RP Zaretsky, EV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 29 TC 4 Z9 4 U1 1 U2 3 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 1040-2004 EI 1547-397X J9 TRIBOL T JI Tribol. Trans. PD OCT-DEC PY 2007 VL 50 IS 4 BP 507 EP 516 DI 10.1080/10402000701613799 PG 10 WC Engineering, Mechanical SC Engineering GA 227VA UT WOS:000250684700008 ER PT J AU Druyan, LM Fulakeza, M Lonergan, P AF Druyan, Leonard M. Fulakeza, Matthew Lonergan, Patrick TI Spatial variability of regional model simulated June-September mean precipitation over West Africa SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BIG-BROTHER EXPERIMENT; CLIMATE MODELS; PARAMETERIZATION AB The study examines the spatial variability of June September 2003 mean precipitation rates (Pr03) simulated by a regional climate model on a horizontal grid with 0.5 degrees spacing. In particular, it evaluates the relative impact of different initial conditions versus the influence of the lateral boundary conditions (LBC), and it compares small spatial scale distributions of modeled Pr03 to data from the Tropical Rainfall Measuring Mission (TRMM) and the NOAA Climate Prediction Center data for the African Famine Early Warning System (FEWS). Simulations over West Africa were made with the CCSR/ GISS RM3, driven by synchronous data from NCEP reanalysis. A five-member ensemble for a single season was generated by staggering the initial conditions of each member by 36 hr within the period May 9-15, 2003. Results showed that the LBC influence dominated over that of differing initial conditions, implying that the precipitation simulations suffered little contamination of random noise. In a second evaluation, small spatial scale distributions of Pr03 were computed as the difference between Pr03 and spatially smoothed fields. Spatial correlations between the RM3 product versus the TRMM and FEWS small-scale components of Pr03 were highest using TRMM data provided at 1 degrees elements. Results suggest that the model may be challenged to simulate realistic small-scale features of the seasonal mean precipitation field, and/ or that observational data sets do not adequately capture these fine spatial features. C1 Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. NASA Goddard Inst Space Studies, New York, NY USA. RP Druyan, LM (reprint author), Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. EM ld12@columbia.edu NR 11 TC 6 Z9 6 U1 0 U2 0 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 SEP 29 PY 2007 VL 34 IS 18 AR L18709 DI 10.1029/2007GL031270 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 216AW UT WOS:000249851100005 ER PT J AU Kunori, T Nose, M Taguchi, S Hosokawa, K Collier, MR Moore, TE AF Kunori, T. Nose, M. Taguchi, S. Hosokawa, K. Collier, M. R. Moore, T. E. TI Storm phase dependence of ion outflow: Statistical signatures obtained by IMAGE/LENA SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NEUTRAL ATOMS; PRECIPITATION; MAGNETOSPHERE; O+ AB The low-energy neutral atom (LENA) imager on board the Imager for Magnetopause-to-Aurora Global Exploration ( IMAGE) spacecraft can observe energetic neutral atoms (ENA) of 10 eV to a few keV generated by upflowing ions through charge exchange with the Earth's exosphere. Using IMAGE/LENA data, we statistically analyzed behaviors of the ion outflow in the main and recovery phases of the magnetic storms from June 2000 to December 2001. Results show that during the main phase, most of ENA emissions from the Earth's direction are accompanied by the solar wind dynamic pressure (P-dy) enhancements. For the recovery phase, there are no such tendencies. Instead, the ENA flux shows large values at the beginning of the recovery phase, and then decreases with the storm recovery. These results suggest that the dominant mechanism responsible for the ion outflow during the magnetic storms can be totally different between the two phases. C1 Kyoto Univ, Grad Sch Sci, Dept Geophys, Sakyo Ku, Kyoto 6068502, Japan. Kyoto Univ, Grad Sch Sci, Data Anal Ctr Geomagnetism & Space Magnetism, Kyoto 6068502, Japan. Univ Electrocommun, Dept Informat & Commun Engn, Tokyo 1828585, Japan. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Kunori, T (reprint author), Kyoto Univ, Grad Sch Sci, Dept Geophys, Sakyo Ku, Kyoto 6068502, Japan. EM kunori@kugi.kyoto-u.ac.jp RI Moore, Thomas/D-4675-2012; Collier, Michael/I-4864-2013; Nose, Masahito/B-1900-2015 OI Moore, Thomas/0000-0002-3150-1137; Collier, Michael/0000-0001-9658-6605; Nose, Masahito/0000-0002-2789-3588 NR 18 TC 5 Z9 5 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 SEP 28 PY 2007 VL 34 IS 18 AR L18106 DI 10.1029/2007GL029877 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 216AV UT WOS:000249851000001 ER PT J AU Jiang, JH Livesey, NJ Su, H Neary, L McConnell, JC Richards, NAD AF Jiang, Jonathan H. Livesey, Nathaniel J. Su, Hui Neary, Lori McConnell, John C. Richards, Nigel A. D. TI Connecting surface emissions, convective uplifting, and long-range transport of carbon monoxide in the upper troposphere: New observations from the Aura Microwave Limb Sounder SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EOS MLS; SATELLITE; OUTFLOW AB [1] Two years of observations of upper tropospheric ( UT) carbon monoxide ( CO) from the Aura Microwave Limb Sounder are analyzed; in combination with the CO surface emission climatology and data from the NCEP analyses. It is shown that spatial distribution, temporal variation and long-range transport of UT CO are closely related to the surface emissions, deep-convection and horizontal winds. Over the Asian monsoon region, surface emission of CO peaks in boreal spring due to high biomass burning in addition to anthropogenic emission. However, the UT CO peaks in summer when convection is strongest and surface emission of CO is dominated by anthropogenic source. The long-range transport of CO from Southeast Asia across the Pacific to North America, which occurs most frequently during boreal summer, is thus a clear imprint of Asian anthropogenic pollution influencing global air quality. C1 CALTECH, Jet Prop Lab, Pasadena, CA USA. York Univ, Dept Earth & Space Sci & Engn, Toronto, ON M3J 2R7, Canada. Univ Leeds, Inst Atmospher Sci, Leeds, W Yorkshire, England. RP Jiang, JH (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA USA. EM jonathan.h.jiang@jpl.nasa.gov NR 13 TC 54 Z9 58 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 SEP 27 PY 2007 VL 34 IS 18 AR L18812 DI 10.1029/2007GL030638 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 216AU UT WOS:000249850900003 ER PT J AU Kundu, PK Siddani, RK AF Kundu, Prasun K. Siddani, Ravi K. TI A new class of probability distributions for describing the spatial statistics of area-averaged rainfall SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID FULLY-DEVELOPED TURBULENCE; LOG-POISSON STATISTICS; MESOSCALE RAINFALL; STOCHASTIC-MODEL; MULTISCALING PROPERTIES; SELF-SIMILARITY; RANDOM CASCADES; TOGA COARE; TIME; FIELDS AB Rainfall exhibits extreme variability at many space and timescales and calls for a statistical description. Based on an analysis of radar measurements of precipitation over the tropical oceans, we introduce a new probability law for the area-averaged rain rate within the class of log-infinitely divisible distributions that accurately describes the frequency of the most intense rain events. The dependence of its parameters on the spatial averaging length L allows one to relate spatial statistics at different scales. In particular, it enables us to explain the observed power law scaling of the moments of the rain rate data and successfully predicts the continuous spectrum of scaling exponents expressing the multiscaling property of the rain intensity field. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Math & Stat, Baltimore, MD 21228 USA. RP Kundu, PK (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. EM kundu@climate.gsfc.nasa.gov RI Kundu, Prasun/C-7212-2013 OI Kundu, Prasun/0000-0002-2284-9852 NR 64 TC 7 Z9 7 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 2007 VL 112 IS D18 AR D18113 DI 10.1029/2006JD008042 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 216BB UT WOS:000249851600002 ER PT J AU Fox, JL Kasprzak, WT AF Fox, J. L. Kasprzak, W. T. TI Near-terminator venus ionosphere: Evidence for a dawn/dusk asymmetry in the thermosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MONOCHROMATIC RADIATION; ELECTRON-TEMPERATURE; ROTATING EARTH; IR NIGHTGLOW; ATMOSPHERE; ABSORPTION; DYNAMICS; DAYSIDE; SYSTEM; MASS AB N(2)Recent models of the near-terminator ionosphere of Venus constructed using neutral density profiles from the VTS3 model of Hedin et al. (1983) have shown that altitudes of the electron density peaks are in agreement with those measured by Pioneer Venus (PV) Orbiter Radio Occultation (ORO) and other radio occultation profiles in the solar zenith angle (SZA) range 60 to 70 degrees, where they are near 140 km (Fox, 2007). The model peaks in the 75-85 degrees range, however, do not decrease in altitude to near 135 km, as do the PV ORO electron density peaks shown in the study of Cravens et al. (1981). We investigate here possible reasons for this decrease. The PV Orbiter Neutral Mass Spectrometer (ONMS) measured densities of CO(2), O, CO, N(2), N, and He for many of the first 600 orbits. We have chosen 10 orbits in the dawn sector and 12 orbits in the dusk sector for which the solar zenith angles at periapsis were in the 75-85 degrees range, and we have examined the ONMS density profiles reported in the PV Unified Abstract Data System. We find that for most of the orbits, the appropriately normalized ONMS measured densities for CO(2) and O are, however, either similar to or larger than those generated from the VTS3 model for the same solar zenith angle and F(10.7) flux, and the use of these densities in our models would therefore produce a higher, rather than a lower, peak. The VTS3 models are, however, not expected to be accurate in the terminator region because of the small number of spherical harmonics used in the models and the large density changes that are expected near the terminators. We have also investigated a possible dawn/dusk asymmetry in the ionosphere. All the low-altitude PV radio occultation electron density peaks reported in the study of Cravens et al. (1981) in the 70 to 85 degrees range were in the dawn sector at high latitudes. In the VTS3 models, the exospheric temperatures are predicted to be smaller at dawn that at dusk, but the asymmetries are confined to the region above similar to 165 km. Thus use of the VTS3 model densities and temperatures in the near-terminator dawn sector models cannot produce electron density peaks that are lower in altitude than those in the dusk sector. We suggest that there is a high-latitude asymmetry between the dawn and dusk neutral densities that extends down to within similar to 20 km above the expected altitude of the electron density peaks, and that produces a significantly asymmetrical ionosphere. C1 Wright State Univ, Dept Phys, Dayton, OH 45435 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Fox, JL (reprint author), Wright State Univ, Dept Phys, Dayton, OH 45435 USA. NR 32 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 SEP 27 PY 2007 VL 112 IS E9 AR E09008 DI 10.1029/2007JE002899 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 216BV UT WOS:000249853700001 ER PT J AU Kahn, RA Garay, MJ Nelson, DL Yau, KK Bull, MA Gaitley, BJ Martonchik, JV Levy, RC AF Kahn, Ralph A. Garay, Michael J. Nelson, David L. Yau, Kevin K. Bull, Michael A. Gaitley, Barbara J. Martonchik, John V. Levy, Robert C. TI Satellite-derived aerosol optical depth over dark water from MISR and MODIS: Comparisons with AERONET and implications for climatological studies SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID IMAGING SPECTRORADIOMETER MODIS; SKY RADIANCE MEASUREMENTS; SOUTHERN AFRICA; DRY SEASON; OCEAN; RETRIEVAL; CALIBRATION; INSTRUMENT; MODEL; LAND AB Although the current Multiangle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite passive remote sensing midvisible aerosol optical thickness (AOT) products are accurate overall to about 0.05 or 20%, they differ systematically on a global, monthly average basis, by about 0.03 to 0.05. Some key climate change and other applications require accuracies of 0.03 or better. The instruments are sufficiently stable and well characterized, and have adequate signal-to-noise, to realize such precision. However, assumptions made in the current standard aerosol retrieval algorithms produce AOT biases that must be addressed first. We identify the causes of AOT discrepancies over dark water under typical, relatively low AOT conditions and quantify their magnitudes on the basis of detailed analysis. Examples were selected to highlight key issues for which there are coincident MISR, MODIS, and Aerosol Robotic Network (AERONET) observations. Instrument calibration and sampling differences, assumptions made in the MISR and MODIS standard algorithms about ocean surface boundary conditions, missing particle property or mixture options, and the way reflectances used in the retrievals are selected each contribute significantly to the observed differences under some circumstances. Cloud screening is also identified as a factor, though not fully examined here, as are the relatively rare high-AOT cases over ocean. Specific algorithm upgrades and further studies indicated by these findings are discussed, along with recommendations for effectively using the currently available products for regional and global applications. C1 CALTECH, Jet Propulsion Lab, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kahn, RA (reprint author), CALTECH, Jet Propulsion Lab, Pasadena, CA 91125 USA. EM ralph.kahn@jpl.nasa.gov RI Levy, Robert/M-7764-2013; Kahn, Ralph/D-5371-2012 OI Levy, Robert/0000-0002-8933-5303; Kahn, Ralph/0000-0002-5234-6359 NR 59 TC 92 Z9 92 U1 0 U2 11 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 SEP 26 PY 2007 VL 112 IS D18 AR D18205 DI 10.1029/2006JD008175 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 216BA UT WOS:000249851500002 ER PT J AU Weinstock, EM Pittman, JV Sayres, DS Smith, JB Anderson, JG Wofsy, SC Xueref, I Gerbig, C Daube, BC Pfister, L Richard, EC Ridley, BA Weinheimer, AJ Jost, HJ Lopez, JP Loewenstein, M Thompson, TL AF Weinstock, E. M. Pittman, J. V. Sayres, D. S. Smith, J. B. Anderson, J. G. Wofsy, S. C. Xueref, I. Gerbig, C. Daube, B. C. Pfister, L. Richard, E. C. Ridley, B. A. Weinheimer, A. J. Jost, H.-J. Lopez, J. P. Loewenstein, M. Thompson, T. L. TI Quantifying the impact of the North American monsoon and deep midlatitude convection on the subtropical lowermost stratosphere using in situ measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR; ATMOSPHERIC OBSERVATIONS; TROPOSPHERE EXCHANGE; TROPICAL TROPOPAUSE; TRACER MEASUREMENTS; CARBON-DIOXIDE; SEASONAL CYCLE; TRANSPORT; CO2; OZONE AB The chemical composition of the lowermost stratosphere exhibits both spatial and temporal variability depending upon the relative strength of (1) isentropic transport from the tropical tropopause layer (TTL), (2) diabatic descent from the midlatitude and northern midlatitude stratosphere followed by equatorward isentropic transport, and (3) diabatic ascent from the troposphere through convection. In situ measurements made in the lowermost stratosphere over Florida illustrate the additional impact of equatorward flow around the monsoon anticyclone. This flow carries, along with older stratospheric air, the distinct signature of deep midlatitude convection. We use simultaneous in situ measurements of water vapor (H2O), ozone (O-3), total odd nitrogen (NOy), carbon dioxide (CO2), and carbon monoxide (CO) in the framework of a simple box model to quantify the composition of the air sampled in the lowermost stratosphere during the mission on the basis of tracer mixing ratios ascribed to the source regions for these transport pathways. The results show that in the summer, convection has a significant impact on the composition of air in the lowermost stratosphere, being the dominant source of water vapor up to the 380 K isentrope. The implications of these results extend from the potential for heterogeneous ozone loss resulting from the increased frequency and lifetime of cirrus near the local tropopause, to air with increased water vapor that as part of the equatorward flow associated with the North American monsoon can become part of the general circulation. C1 Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Lab Sci Climat Environm,Commis Energie Atom, Gif Sur Yvette, France. Max Planck Biogeochem, Jena, Germany. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. NovaWave Technol, Redwood City, CA USA. NOAA, Earth Syst Res Lab, Boulder, CO USA. RP Weinstock, EM (reprint author), Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. EM elliot@huarp.harvard.edu RI Gerbig, Christoph/L-3532-2013 OI Gerbig, Christoph/0000-0002-1112-8603 NR 37 TC 4 Z9 4 U1 1 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 SEP 26 PY 2007 VL 112 IS D18 AR D18310 DI 10.1029/2007JD008554 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 216BA UT WOS:000249851500003 ER EF