FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Krauss, MI Wang, ZX Dullighan, A Juett, AM Kaplan, DL Chakrabarty, D van Kerkwijk, MH Steeghs, D Jonker, PG Markwardt, CB AF Krauss, MI Wang, ZX Dullighan, A Juett, AM Kaplan, DL Chakrabarty, D van Kerkwijk, MH Steeghs, D Jonker, PG Markwardt, CB TI The X-ray position and optical counterpart of the accretion-powered millisecond pulsar XTE J1814-338 SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; pulsars : individual ( XTE J1814-338); stars : neutron; X-rays : binaries ID BINARY; OUTBURST; STARS; DISCOVERY; SPECTROSCOPY; CONSTRAINTS; EVOLUTION; MASS AB We report the precise optical and X-ray localization of the 3.2 ms accretion-powered X- ray pulsar XTE J1814-338 with data from the Chandra X- Ray Observatory as well as optical observations conducted during the 2003 June discovery outburst. Optical imaging of the field during the outburst of this soft X- ray transient reveals an R = 18 star at the X- ray position. This star is absent ( R > 20) from an archival 1989 image of the field and brightened during the 2003 outburst, and we therefore identify it as the optical counterpart of XTE J1814-338. The best source position derived from optical astrometry is R.A. = 18(h)13(m)39(s).04, decl: = -33 degrees 46'22."3 (J2000). The featureless X- ray spectrum of the pulsar in outburst is best fit by an absorbed power law ( with photon index gamma = 1: 41 +/- 0: 06) plus blackbody (with kT = 0: 95 +/- 0: 13 keV) model, where the blackbody component contributes approximately 10% of the source flux. The optical broadband spectrum shows evidence for an excess of infrared emission with respect to an X- ray heated accretion disk model, suggesting a significant contribution from the secondary or from a synchrotron-emitting region. A follow-up observation performed when XTE J1814-338 was in quiescence reveals no counterpart to a limiting magnitude of R = 23:3. This suggests that the secondary is an M3 V or later-type star and therefore very unlikely to be responsible for the soft excess, making synchrotron emission a more reasonable candidate. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Toronto, Dept Astron & Astrophys, Toronto, ON M5S 3H8, Canada. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Krauss, MI (reprint author), MIT, Dept Phys, Cambridge, MA 02139 USA. EM miriam@space.mit.edu; wangzx@space.mit.edu; allyn@space.mit.edu; ajuett@space.mit.edu; dlk@space.mit.edu; deepto@space.mit.edu; mhvk@astro.utoronto.ca; dsteeghs@cfa.harvard.edu; p.jonker@sron.nl; craigm@milkyway.gsfc.nasa.gov RI Steeghs, Danny/C-5468-2009 OI Steeghs, Danny/0000-0003-0771-4746 NR 36 TC 25 Z9 25 U1 0 U2 1 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 JUL 10 PY 2005 VL 627 IS 2 BP 910 EP 914 DI 10.1086/430595 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 941CH UT WOS:000230191800028 ER PT J AU Strohmayer, TE AF Strohmayer, TE TI Precision X-ray timing of RX J0806.3+1527 with Chandra: Evidence for gravitational radiation from an ultracompact binary SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; gravitational waves; stars : individual ( RX J0806.3+1527, V407 Vulpeculae); white dwarfs; X-rays : binaries ID MASS-TRANSFER INSTABILITIES; SHORTEST PERIOD BINARY; DOUBLE WHITE-DWARFS; SPIN-UP; ORBITAL PERIOD; RX-J0806.3+1527; SECONDARIES; RX-J0806+15; EMISSION; J1914+24 AB RX J0806.3+1527 is a candidate double-degenerate binary with possibly the shortest known orbital period. The source shows an approximate to 100% X-ray intensity modulation at the putative orbital frequency of 3.11 mHz (321.5 s). If the system is a detached, ultracompact binary, gravitational radiation should drive spin-up with a magnitude of (v)over dot similar to 10(-16) Hz s(-1). Efforts to constrain the X-ray frequency evolution to date have met with mixed success, principally due to the sparseness of earlier observations. Here we describe the results of the first phase-coherent X-ray monitoring campaign on RX J0806.3+1527 with Chandra. We obtained a total of 70 ks of exposure in six epochs logarithmically spaced over 320 days. With these data we conclusively show that the X-ray frequency is increasing at a rate of (3.77 +/- 0.8) x 10(-16) Hz s(-1). Using the ephemeris derived from the new data, we are able to phase up all the earlier Chandra and ROSAT data and show that they are consistent with a constant. (v)over dot (3.63 +/- 0.06) x 10(-16) Hz s(-1) over the past decade. This value appears consistent with that recently derived by Israel et al., largely from monitoring of the optical modulation, and is in rough agreement with the solutions reported initially by Hakala et al., based on ground-based optical observations. The large and stable (v)over dot over a decade is consistent with gravitational radiation losses driving the evolution. An intermediate polar (IP) scenario in which the observed X-ray period is the spin period of an accreting white dwarf appears less tenable because the observed. (v)over dot requires an (m)over dot approximate to 2 x 10(-8) M-circle dot yr(-1), which is much larger than that inferred from the observed X-ray luminosity (although this depends on the uncertain distance and bolometric corrections), and it is difficult to drive such a high. m in a binary system with parameters consistent with all the multiwavelength data. If the ultracompact scenario is correct, then the X-ray flux cannot be powered by stable accretion, which would drive the components apart, suggesting that a new type of energy source (perhaps electromagnetic) may power the X-ray flux. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Strohmayer, TE (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. EM stroh@clarence.gsfc.nasa.gov NR 32 TC 21 Z9 21 U1 0 U2 1 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 JUL 10 PY 2005 VL 627 IS 2 BP 920 EP 925 DI 10.1086/430439 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 941CH UT WOS:000230191800030 ER PT J AU Lopez, B Schneider, J Danchi, WC AF Lopez, B Schneider, J Danchi, WC TI Can life develop in the expanded habitable zones around red giant stars? SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary systems; stars : evolution; stars : late type; techniques : high angular resolution; techniques : interferometric ID KELVIN-STELLAR-INTERFEROMETER; CARBON-DIOXIDE CLOUDS; CORE HELIUM FLASH; MAIN-SEQUENCE; EARLY MARS; MASS; EVOLUTION; IMPACT; EARTH; PLANETS AB We present some new ideas about the possibility of life developing around subgiant and red giant stars. Our study concerns the temporal evolution of the habitable zone. The distance between the star and the habitable zone, as well as its width, increases with time as a consequence of stellar evolution. The habitable zone moves outward after the star leaves the main sequence, sweeping a wider range of distances from the star until the star reaches the tip of the asymptotic giant branch. Currently there is no clear evidence as to when life actually formed on the Earth, but recent isotopic data suggest life existed at least as early as 7 x 10(8) yr after the Earth was formed. Thus, if life could form and evolve over time intervals from 5 x 10(8) to 10(9) yr, then there could be habitable planets with life around red giant stars. For a 1 M-circle dot star at the first stages of its post-main-sequence evolution, the temporal transit of the habitable zone is estimated to be several times 10(9) yr at 2 AU and around 10(8) yr at 9 AU. Under these circumstances life could develop at distances in the range 2-9 AU in the environment of subgiant or giant stars, and in the far distant future in the environment of our own solar system. After a star completes its first ascent along the red giant branch and the He flash takes place, there is an additional stable period of quiescent He core burning during which there is another opportunity for life to develop. For a 1M(circle dot) star there is an additional 10(9) yr with a stable habitable zone in the region from 7 to 22 AU. Space astronomy missions, such as proposed for the Terrestrial Planet Finder (TPF) and Darwin, that focus on searches for signatures of life on extrasolar planets, should also consider the environments of subgiants and red giant stars as potentially interesting sites for understanding the development of life. We performed a preliminary evaluation of the difficulty of interferometric observations of planets around red giant stars compared to a main-sequence star environment. We show that pathfinder missions for TPF and Darwin, such as Eclipse and FKSI, have sufficient angular resolution and sensitivity to search for habitable planets around some of the closest evolved stars of the subgiant and red giant class. C1 Observ Cote Azur, Dept Gemini, UMR 6203, F-06034 Nice, France. Observ Paris, LUTH, F-92195 Meudon, France. NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. RP Lopez, B (reprint author), Observ Cote Azur, Dept Gemini, UMR 6203, BP 4229, F-06034 Nice, France. EM bruno.lopez@obs-nice.fr; jean.schneider@obspm.fr; william.c.danchi@nasa.gov NR 60 TC 22 Z9 22 U1 3 U2 9 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 JUL 10 PY 2005 VL 627 IS 2 BP 974 EP 985 DI 10.1086/430416 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 941CH UT WOS:000230191800035 ER PT J AU Ardila, DR Lubow, SH Golimowski, DA Krist, JE Clampin, M Ford, HC Hartig, GF Illingworth, GD Bartko, F Benitez, N Blakeslee, JP Bouwens, RJ Bradley, LD Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Cross, NJG Feldman, PD Franx, M Goto, T Gronwall, C Holden, B Homeier, N Infante, L Kimble, RA Lesser, MP Martel, AR Menanteau, F Meurer, GR Miley, GK Postman, M Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W Zirm, AW AF Ardila, DR Lubow, SH Golimowski, DA Krist, JE Clampin, M Ford, HC Hartig, GF Illingworth, GD Bartko, F Benitez, N Blakeslee, JP Bouwens, RJ Bradley, LD Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Cross, NJG Feldman, PD Franx, M Goto, T Gronwall, C Holden, B Homeier, N Infante, L Kimble, RA Lesser, MP Martel, AR Menanteau, F Meurer, GR Miley, GK Postman, M Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W Zirm, AW TI A dynamical simulation of the debris disk around HD 141569A SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; hydrodynamics; planetary systems : formation; planetary systems : protoplanetary disks; stars : individual (HD 141569) ID CIRCUMSTELLAR DISKS; STELLAR COMPANIONS; YOUNG STARS; DUST; PLANETS; PHOTOMETRY; HD-141569A; EMISSION; HD141569; OUTFLOW AB We study the dynamical origin of the structures observed in the scattered-light images of the resolved debris disk around HD 141569A. The disk has two conspicuous spiral rings and two large-scale spiral arms. We explore the roles of radiation pressure from the central star, gas drag from the gas disk, and the tidal forces from two nearby stars in creating and maintaining these structures. The disk's color, scattering function, and infrared emission suggest that submicron-sized grains dominate the dust population observed in scattered light. CO observations indicate the presence of up to 60M(circle dot) of gas. The dust grains are subject to the competing effects of expulsive radiation pressure (beta > 1, where beta is the ratio of the radiation and gravitational forces) and retentive gas drag. We use a simple one-dimensional axisymmetric model to show that the presence of the gas helps confine the dust and that a broad ring of dust is produced if a central hole exists in the disk. This model also suggests that the disk is in a transient, excited dynamical state, as the observed dust creation rate applied over the age of the star is inconsistent with submillimeter mass measurements. We model in two dimensions the effects of a flyby encounter between the disk and a binary star in a prograde, parabolic, coplanar orbit. We track the spatial distribution of the disk's gas, planetesimals, and dust. We conclude that the surface density distribution reflects the planetesimal distribution for a wide range of parameters. Our most viable model features a disk with initial radius 400 AU, a gas mass of 50 M-circle plus, and beta = 4 and suggests that the system is being observed within 4000 yr of the flyby periastron. The model reproduces some features of HD 141569A's disk, such as a broad single ring and large spiral arms, but it does not reproduce the observed multiple spiral rings or disk asymmetries nor the observed clearing in the inner disk. For the latter, we consider the effect of a 5M(J) planet in an eccentric orbit on the planetesimal distribution of HD 141569A. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Santa Cruz, UCO Lick Observ, Santa Cruz, CA 95064 USA. Bartko Sci & Technol, Brighton, CO 80602 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Conceptual Analyt LLC, Glenn Dale, MD 20769 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago, Chile. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. WM Keck Observ, Kamuela, HI 96743 USA. RP Ardila, DR (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. RI White, Richard/A-8143-2012; Clampin, mark/D-2738-2012; Kimble, Randy/D-5317-2012; OI tran, hien/0000-0001-7548-6664; Menanteau, Felipe/0000-0002-1372-2534; Benitez, Narciso/0000-0002-0403-7455; Blakeslee, John/0000-0002-5213-3548 NR 37 TC 28 Z9 28 U1 0 U2 1 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 JUL 10 PY 2005 VL 627 IS 2 BP 986 EP 1000 DI 10.1086/430395 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 941CH UT WOS:000230191800036 ER PT J AU Davis, SS AF Davis, SS TI The surface density distribution in the solar nebula SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; planetary systems : protoplanetary disks; solar system : formation ID CIRCUMSTELLAR DISKS; MOLECULES; EVOLUTION; SYSTEM; STARS AB The commonly used minimum-mass power-law representation of the early solar nebula is reanalyzed using a new cumulative mass model. This model is a first integral of the planetary data and predicts a smoother surface density approximation compared with methods based on direct computation of surface density. The density is quantified using two independent analytical formulations. First, a best-fit transcendental function is applied directly to the basic planetary data. Next, a solution to the time-dependent disk evolution equation is parametrically adapted to the solar nebula data. The latter model is shown to be a good approximation to the finite-size early solar nebula and, by extension, to extrasolar protoplanetary disks. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Davis, SS (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. NR 16 TC 33 Z9 33 U1 0 U2 1 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 JUL 10 PY 2005 VL 627 IS 2 BP L153 EP L155 DI 10.1086/432464 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 941CM UT WOS:000230192300018 ER PT J AU Jenet, FA Creighton, T Lommen, A AF Jenet, FA Creighton, T Lommen, A TI Pulsar timing and the detection of black hole binary systems in globular clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; gravitational waves; pulsars : general ID MILLISECOND PULSARS AB The possible existence of intermediate-mass binary black holes (IMBBHs) in globular clusters (GCs) offers us a unique geometry in which to detect spacetime oscillations. For certain pulsar-IMBBH configurations possible within a GC, the usual far-field plane wave approximation for the IMBBH metric perturbation severely underestimates the induced pulse time-of-arrival (TOA) fluctuations. In this Letter, the expected TOA fluctuations induced by an IMBBH lying close to the line of sight between a pulsar and the Earth are calculated for the first time. For an IMBBH consisting of 10 and 10(3) M-circle dot components, a 10 yr orbital period, and located 0.1 lt-yr from the Earth-pulsar line of sight, the induced TOA fluctuations will be of order 5-500 ns. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Texas, Ctr Gravitat Wave Astron, Brownsville, TX 78520 USA. CALTECH, LIGO Lab, Pasadena, CA 91125 USA. Franklin & Marshall Coll, Dept Phys & Astron, Lancaster, PA 17604 USA. RP Jenet, FA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM merlyn@alum.mit.edu; tdcreigh@ligo.caltech.edu NR 18 TC 10 Z9 10 U1 0 U2 1 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 JUL 10 PY 2005 VL 627 IS 2 BP L125 EP L128 DI 10.1086/431949 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 941CM UT WOS:000230192300011 ER PT J AU Markwick, AJ Charnley, SB Butner, HM Millar, TJ AF Markwick, AJ Charnley, SB Butner, HM Millar, TJ TI Interstellar CH3CCD SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : individual (Taurus molecular cloud); ISM : molecules ID DARK CLOUD CORES; DEUTERATED METHANOL; MOLECULAR CLOUDS; DISSOCIATIVE RECOMBINATION; DEUTERIUM FRACTIONATION; METHYL ACETYLENE; 1ST DETECTION; TMC-1 RIDGE; CHEMISTRY; ABUNDANCE AB We report the detection of a new interstellar molecule: CH3CCD, a deuterated isotopomer of methyl acetylene. Analysis of lines detected at seven positions along the ridge of the dark cloud TMC-1 indicates that the CH3CCD column density and fractionation exhibit strong spatial gradients, with D/H ratios ranging from a minimum of 0.04 at the cyanopolyyne peak (CP) position to as high as 0.18. We find that the column density in CH2DCCH is almost constant along the ridge, whereas that of CH3CCD increases and that of CH3CCH decreases in moving away from the CP. Chemical mechanisms that may explain the observed fractionation trends in CH3CCD and CH2DCCH are briefly discussed. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Joint Astron Ctr, Hilo, HI 96720 USA. Univ Manchester, Astrophys Grp, Sch Phys & Astron, Manchester M60 1QD, Lancs, England. RP Markwick, AJ (reprint author), NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. EM ajm@ajmarkwick.com; charnley@dusty.arc.nasa.gov; h.butner@jach.hawaii.edu; tom.millar@manchester.ac.uk RI Charnley, Steven/C-9538-2012; OI Millar, Tom/0000-0001-5178-3656 NR 32 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 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2005 VL 627 IS 2 BP L117 EP L120 DI 10.1086/432415 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 941CM UT WOS:000230192300009 ER PT J AU Schneider, K Farge, M Pellegrino, G Rogers, MM AF Schneider, K Farge, M Pellegrino, G Rogers, MM TI Coherent vortex simulation of three-dimensional turbulent mixing layers using orthogonal wavelets SO JOURNAL OF FLUID MECHANICS LA English DT Article ID CVS AB This paper assesses the potential of coherent vortex simulation (CVS) to compute three-dimensional turbulent mixing layers. CVS splits each turbulent flow realization IF into two orthogonal parts, one corresponding to coherent vortices which are kept, and the other to an incoherent background flow which is discarded. The CVS filter is applied to data from direct numerical simulations (DNS) of three-dimensional forced and unforced time-developing turbulent mixing layers. The coherent flow is IF represented by few wavelet modes, but these are sufficient to reproduce the vorticity probability distribution function and the energy spectrum out to the high-wavenumber end of the inertial range. The discarded incoherent background flow is homogeneous, small-amplitude and decorrelated. The CVS-filtering results are then compared with those obtained for the same compression ratio using Fourier low-pass filtering, as employed in large-eddy simulation (LES). Compared to the incoherent background flow of CVS filtering, the subgrid scales of LES filtering are less homogeneous, have much larger amplitude, and exhibit spatial correlations that makes modelling them a difficult challenge. Finally we present simulations of a time-developing mixing layer where the CVS filter is applied at each time step. The results show that CVS preserves the nonlinear dynamics of the flow, and that discarding the incoherent modes is sufficient to model turbulent dissipation. C1 CNRS, LMSNM GP, F-13451 Marseille, France. Univ Aix Marseille 1, F-13451 Marseille, France. Univ Aix Marseille 1, CMI, F-13453 Marseille, France. Ecole Normale Super, LMD, CNRS, F-75231 Paris, France. Univ Karlsruhe TH, ICT, D-76128 Karlsruhe, Germany. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Schneider, K (reprint author), CNRS, LMSNM GP, 38 Rue Joliot Curie, F-13451 Marseille, France. NR 19 TC 40 Z9 40 U1 0 U2 5 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD JUL 10 PY 2005 VL 534 BP 39 EP 66 DI 10.1017/S0022112005004234 PG 28 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 948EM UT WOS:000230698800003 ER PT J AU Liemohn, MW Moore, TE Craven, PD Maddox, W Nagy, AF Kozyra, JU AF Liemohn, MW Moore, TE Craven, PD Maddox, W Nagy, AF Kozyra, JU TI Occurrence statistics of cold, streaming ions in the near-Earth magnetotail: Survey of Polar-TIDE observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; SHEET BOUNDARY-LAYER; SOLAR-WIND-ORIGIN; AURORAL RED ARCS; PLASMA SHEET; PLASMASPHERIC MATERIAL; GEOMAGNETIC STORM; IONOSPHERIC IONS; O+ BEAMS; MAGNETOSPHERE AB [1] Results are presented from a survey of cold ion observations in the near-Earth magnetotail using data from the Polar Thermal Ion Dynamics Experiment ( TIDE). During the interval from July to December of 2001, Polar had its apogee ( similar to 9.5 R-E) near the equatorial plane in the tail region of the magnetosphere. It is shown that a lobal wind is ubiquitous in the inner tail, with low-energy (< 300 eV) ions streaming from the ionosphere downtail. These lobal winds often pass through the plasma sheet, forming bidirectional streams, in addition to the unidirectional beams seen at higher magnetic latitudes. The observance of bidirectional streams is inversely, although weakly, correlated with geomagnetic activity. Bidirectional streams are interpreted as indicating the minimum size of the closed flux tube region. The reduced frequency of bidirectional streams with activity level times is consistent with the thinning of the plasma sheet during these times. It is inferred from the universality of these observations during Polar's passage through the inner tail region that the ionosphere is a continuous supplier of plasma to the near-Earth magnetosphere. The high occurrence rate of these streams means that during geomagnetic disturbances, it is not necessary to wait for outflow and magnetospheric circulation in order to supply the inner magnetosphere with ionospheric ions; these cold streams are an immediately available supply of ionospheric-origin particles. C1 Univ Michigan, Dept Atmospher Ocean & Space Sci, Space Phys Res Lab, Ann Arbor, MI 48109 USA. NASA, Goddard Space Flight Ctr, Lab Extraterr Phys, Greenbelt, MD 20771 USA. NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. RP Univ Michigan, Dept Atmospher Ocean & Space Sci, Space Phys Res Lab, 2455 Hayward St, Ann Arbor, MI 48109 USA. EM liemohn@umich.edu RI Moore, Thomas/D-4675-2012; Liemohn, Michael/H-8703-2012 OI Moore, Thomas/0000-0002-3150-1137; Liemohn, Michael/0000-0002-7039-2631 NR 72 TC 10 Z9 10 U1 0 U2 2 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 JUL 9 PY 2005 VL 110 IS A7 AR A07211 DI 10.1029/2004JA010801 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 947KM UT WOS:000230642300002 ER PT J AU Zheng, YH Moore, TE Mozer, FS Russell, CT Strangeway, RJ AF Zheng, YH Moore, TE Mozer, FS Russell, CT Strangeway, RJ TI Polar study of ionospheric ion outflow versus energy input SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID LATITUDE F-REGION; MAGNETOSPHERIC PLASMA; POYNTING FLUX; ALFVEN WAVES; INSTRUMENT; ELECTRON; AURORA; MAGNETOTAIL; DEPENDENCE; SPACECRAFT AB [1] A statistical study of the ion outflow versus energy input is performed by using multi-instrument data ( TIDE, EFI, MFI, HYDRA) from Polar during its perigee auroral passes in the year 2000. Several important physical quantities connected to the ion outflow have been investigated, including the Poynting flux from the perturbation fields ( below 1/6 Hz), the electron density, temperature, and the electron energy flux. The perturbation fields used here to calculate the Poynting flux may be associated with the small-scale quasi-static field structures of the field-aligned currents or/and the very low frequency Alfven waves ( below 1/6 Hz), which are both proven to be important energy sources for powering the aurora. Our results show that the field-aligned ion outflow flux correlates best with the Earth-directed Poynting flux and the precipitating electron density and also demonstrates almost no correlation with the electron energy flux and temperature. The findings from this Polar study are similar to those from FAST. The general corroboration between the independent data sets of the two spacecraft suggests that the empirical ion outflow scaling laws can be established, which will be beneficial to global simulation efforts. Our results show that at 6000 km altitudes f(i) = 10(6.836 +/- 0.028) S0.535 +/- 0.086 and f(i) = 10(6.650 +/- 0.063) n(e) (0.484 +/- 0.147), where f(i) is the total field-aligned ion outflow flux in 1/cm(2)/s, S is the Poynting flux in ergs/cm(2)/s, and ne is the electron density in 1/cm(3). C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. RP Zheng, YH (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM yihua.zheng@jhuapl.edu; thomas.e.moore@nasa.gov; mozer@ssl.berkeley.edu; ctrussell@igpp.ucla.edu; strange@igpp.ucla.edu RI Moore, Thomas/D-4675-2012; Zheng, Yihua/D-7368-2012 OI Moore, Thomas/0000-0002-3150-1137; NR 37 TC 35 Z9 35 U1 0 U2 5 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 JUL 9 PY 2005 VL 110 IS A7 AR A07210 DI 10.1029/2004JA010995 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 947KM UT WOS:000230642300004 ER PT J AU Myhre, G Stordal, F Johnsrud, M Diner, DJ Geogdzhayev, IV Haywood, JM Holben, BN Holzer-Popp, T Ignatov, A Kahn, RA Kaufman, YJ Loeb, N Martonchik, JV Mishchenko, MI Nalli, NR Remer, LA Schroedter-Homscheidt, M Tanre, D Torres, O Wang, M AF Myhre, G Stordal, F Johnsrud, M Diner, DJ Geogdzhayev, IV Haywood, JM Holben, BN Holzer-Popp, T Ignatov, A Kahn, RA Kaufman, YJ Loeb, N Martonchik, JV Mishchenko, MI Nalli, NR Remer, LA Schroedter-Homscheidt, M Tanre, D Torres, O Wang, M TI Intercomparison of satellite retrieved aerosol optical depth over ocean during the period September 1997 to December 2000 SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID HIGH-RESOLUTION RADIOMETER; SIMULTANEOUS GOME SPECTROMETER; INDIVIDUAL AVHRR CHANNELS; TROPOSPHERIC AEROSOLS; CONSISTENCY CHECKS; SOLAR SPECTRUM; BOUNDARY-LAYER; AIR-POLLUTION; CLOUD; VALIDATION AB Monthly mean aerosol optical depth (AOD) over ocean is compared from a total of 9 aerosol retrievals during a 40 months period. Comparisons of AOD have been made both for the entire period and sub periods. We identify regions where there is large disagreement and good agreement between the aerosol satellite retrievals. Significant differences in AOD have been identified in most of the oceanic regions. Several analyses are performed including spatial correlation between the retrievals as well as comparison with AERONET data. During the 40 months period studied there have been several major aerosol field campaigns as well as events of high aerosol content. It is studied how the aerosol retrievals compare during such circumstances. The differences found in this study are larger than found in a previous study where 5 aerosol retrievals over an 8 months period were compared. Part of the differences can be explained by limitations and deficiencies in some of the aerosol retrievals. In particular, results in coastal regions are promising especially for aerosol retrievals from satellite instruments particularly suited for aerosol research. In depth analyses explaining the differences between AOD obtained in different retrievals are clearly needed. We limit this study to identifying differences and similarities and indicating possible sources that affect the quality of the retrievals. This is a necessary first step towards understanding the differences and improving the retrievals. C1 Norwegian Inst Air Res, Kjeller, Norway. Univ Oslo, Dept Geosci, Oslo, Norway. CALTECH, Jet Prop Lab, Pasadena, CA USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Met Off, Exeter, Devon, England. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. DLR, DFD, Oberpfaffenhofen, Germany. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Climate Res & Applicat Div, Washington, DC 20233 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. Univ Lille, CNRS, Opt Atmospher Lab, Villeneuve Dascq, France. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Baltimore, MD 21228 USA. RP Myhre, G (reprint author), Norwegian Inst Air Res, Kjeller, Norway. EM gunnar.myhre@geo.uio.no RI Myhre, Gunnar/A-3598-2008; Ignatov, Alexander/F-5594-2010; Nalli, Nicholas/F-6731-2010; Wang, Menghua/F-5631-2010; Kahn, Ralph/D-5371-2012; Torres, Omar/G-4929-2013; Mishchenko, Michael/D-4426-2012; OI Myhre, Gunnar/0000-0002-4309-476X; Ignatov, Alexander/0000-0002-7463-5944; Nalli, Nicholas/0000-0002-6914-5537; Wang, Menghua/0000-0001-7019-3125; Kahn, Ralph/0000-0002-5234-6359; Stordal, Frode/0000-0002-5190-6473 NR 60 TC 53 Z9 54 U1 1 U2 7 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JUL 8 PY 2005 VL 5 BP 1697 EP 1719 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 944TT UT WOS:000230453500002 ER PT J AU Li, KF Cageao, RP Karpilovsky, EM Mills, FP Yung, YL Margolis, JS Sander, SP AF Li, KF Cageao, RP Karpilovsky, EM Mills, FP Yung, YL Margolis, JS Sander, SP TI OH column abundance over Table Mountain Facility, California: AM-PM diurnal asymmetry SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC HYDROXYL; MIDDLE ATMOSPHERE; DOPPLER DETECTION; MODEL; BAND AB Observations of the OH column abundance have been made by the Fourier Transform Ultraviolet Spectrometer at the JPL Table Mountain Facility (TMF) near Los Angeles since July 1997. In the January 1998 December 2003 data set we used five OH lines to derive the OH column abundance in the atmosphere. This data set was used to quantify the OH morning/afternoon asymmetry (AMPMDA). An analysis of summer and winter data showed that the daily OH maximum occurred 26 - 36 minutes after solar transit. This phase lag appears to be the primary reason why OH in the afternoon is larger than at corresponding solar zenith angles in the morning throughout the year. A simple heuristic model suggests that the asymmetry is a direct consequence of the finite lifetime of OH. Comparison of the TMF data with earlier results from Fritz Peak Observatory, Colorado, by Burnett et al. reveals significant differences in the behavior of the AMPMDA between the two sites. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91007 USA. Princeton Univ, Dept Comp Sci, Princeton, NJ 08544 USA. Remote Sensing Anal Syst, Altadena, CA 91001 USA. ANU, Canberra, ACT, Australia. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Li, KF (reprint author), Chinese Univ Hong Kong, Dept Phys, Shatin, Hong Kong, Peoples R China. EM ssander@jpl.nasa.gov OI Li, King-Fai/0000-0003-0150-2910 NR 19 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 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 8 PY 2005 VL 32 IS 13 AR L13813 DI 10.1029/2005GL022521 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 947JN UT WOS:000230639600002 ER PT J AU Huang, CS Reeves, GD Le, G Yumoto, K AF Huang, CS Reeves, GD Le, G Yumoto, K TI Are sawtooth oscillations of energetic plasma particle fluxes caused by periodic substorms or driven by solar wind pressure enhancements? SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; MAGNETOSPHERIC SUBSTORMS; SUDDEN IMPULSES; LOW-LATITUDE; EARTHS MAGNETOSPHERE; GEOTAIL OBSERVATIONS; STORMS; RECONNECTION; ONSETS; SHAPE AB [1] Energetic electron and proton fluxes measured by geosynchronous satellites often show sawtooth-like variations during magnetic storms. We examine whether the sawtooth oscillations and relevant magnetospheric-ionospheric disturbances are caused by periodic substorms or driven by a series of enhancements in the solar wind pressure. We show that there are significant differences between periodic substorms and solar wind-induced variations. The energetic fluxes at geosynchronous orbit may increase by orders of magnitude after each onset of periodic substorms and by 10 - 50% in response to a large solar wind pressure impulse. The sudden increases of the energetic fluxes during periodic substorms show significant time delays of 30 - 50 min at different longitudes/local times, indicating that the fluxes are injected on the nightside and then drift to the dayside. In contrast, the small flux increases caused by solar wind pressure enhancements occur almost simultaneously at all local times. The periodic substorms always have a strong spectrum peak at 2 - 3 hours, no matter whether the solar wind pressure and/or IMF have similar spectrum peaks. The nightside magnetospheric magnetic elevation angle shows a large ( 30 - 60 degrees) increase at each onset of periodic substorms through dipolarization and a small (< 10 degrees) decrease in response to a solar wind pressure impulse. Each cycle of periodic substorms can cause a deviation of 40 - 60 nT in the midlatitude geomagnetic field; the midlatitude geomagnetic deviations caused by solar wind pressure enhancements are proportional to the square root of the pressure change. The increase of the polar cap index caused by substorms is similar to 4 times that caused by solar wind pressure enhancements. We conclude that the sawtooth-like flux oscillations represent flux injections during periodic substorms and that the period of substorms is determined by the magnetosphere. C1 MIT, Haystack Observ, Westford, MA 01886 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Kyushu Univ, Space Environm Res Ctr, Fukuoka 812, Japan. RP Huang, CS (reprint author), MIT, Haystack Observ, Route 40, Westford, MA 01886 USA. EM cshuang@haystack.mit.edu; reeves@lanl.gov; guan.le@nasa.gov; yumoto@geo.kyushu-u.ac.jp RI Le, Guan/C-9524-2012; Reeves, Geoffrey/E-8101-2011 OI Le, Guan/0000-0002-9504-5214; Reeves, Geoffrey/0000-0002-7985-8098 NR 41 TC 22 Z9 22 U1 0 U2 2 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 JUL 7 PY 2005 VL 110 IS A7 AR A07207 DI 10.1029/2005JA011018 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 947KJ UT WOS:000230642000002 ER PT J AU Golombek, MP Arvidson, RE Bell, JF Christensen, PR Crisp, JA Crumpler, LS Ehlmann, BL Fergason, RL Grant, JA Greeley, R Haldemann, AFC Kass, DM Parker, TJ Schofield, JT Squyres, SW Zurek, RW AF Golombek, MP Arvidson, RE Bell, JF Christensen, PR Crisp, JA Crumpler, LS Ehlmann, BL Fergason, RL Grant, JA Greeley, R Haldemann, AFC Kass, DM Parker, TJ Schofield, JT Squyres, SW Zurek, RW TI Assessment of Mars Exploration Rover landing site predictions SO NATURE LA English DT Article ID THERMAL EMISSION SPECTROMETER; GUSEV CRATER; MERIDIANI-PLANUM; SPIRIT ROVER; MICROSCOPIC IMAGER; LOCALIZATION; OPPORTUNITY; SELECTION; DEPOSITS; SURFACE AB Comprehensive analyses of remote sensing data during the three-year effort to select the Mars Exploration Rover landing sites at Gusev crater and at Meridiani Planum correctly predicted the atmospheric density profile during entry and descent and the safe and trafficable surfaces explored by the two rovers. The Gusev crater site was correctly predicted to be a low-relief surface that was less rocky than the Viking landing sites but comparably dusty. A dark, low-albedo, flat plain composed of basaltic sand and haematite with very few rocks was expected and found at Meridiani Planum. These results argue that future efforts to select safe landing sites based on existing and acquired remote sensing data will be successful. In contrast, geological interpretations of the sites based on remote sensing data were less certain and less successful, which emphasizes the inherent ambiguities in understanding surface geology from remotely sensed data and the uncertainty in predicting exactly what materials will be available for study at a landing site. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Washington Univ, St Louis, MO 63130 USA. Cornell Univ, Ithaca, NY 14853 USA. Arizona State Univ, Tempe, AZ 85287 USA. New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA. Univ Oxford, Oxford OX1 3PG, England. Smithsonian Inst, Washington, DC 20560 USA. RP Golombek, MP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mgolombek@jpl.nasa.gov RI Crisp, Joy/H-8287-2016 OI Crisp, Joy/0000-0002-3202-4416 NR 38 TC 55 Z9 58 U1 0 U2 7 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUL 7 PY 2005 VL 436 IS 7047 BP 44 EP 48 DI 10.1038/nature03600 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 942QJ UT WOS:000230296600035 PM 16001058 ER PT J AU Yen, AS Gellert, R Schroder, C Morris, RV Bell, JF Knudson, AT Clark, BC Ming, DW Crisp, JA Arvidson, RE Blaney, D Bruckner, J Christensen, PR DesMarais, DJ de Souza, PA Economou, TE Ghosh, A Hahn, BC Herkenhoff, KE Haskin, LA Hurowitz, JA Joliff, BL Johnson, JR Klingelhofer, G Madsen, MB McLennan, SM McSween, HY Richter, L Rieder, R Rodionov, D Soderblom, L Squyres, SW Tosca, NJ Wang, A Wyatt, M Zipfel, J AF Yen, AS Gellert, R Schroder, C Morris, RV Bell, JF Knudson, AT Clark, BC Ming, DW Crisp, JA Arvidson, RE Blaney, D Bruckner, J Christensen, PR DesMarais, DJ de Souza, PA Economou, TE Ghosh, A Hahn, BC Herkenhoff, KE Haskin, LA Hurowitz, JA Joliff, BL Johnson, JR Klingelhofer, G Madsen, MB McLennan, SM McSween, HY Richter, L Rieder, R Rodionov, D Soderblom, L Squyres, SW Tosca, NJ Wang, A Wyatt, M Zipfel, J TI An integrated view of the chemistry and mineralogy of martian soils SO NATURE LA English DT Article ID THERMAL EMISSION SPECTROMETER; X-RAY SPECTROMETER; MINI-TES EXPERIMENT; GUSEV CRATER; MERIDIANI-PLANUM; MARS PATHFINDER; SPIRIT ROVER; CHEMICAL-COMPOSITION; OPPORTUNITY ROVER; MOSSBAUER SPECTROMETER AB The mineralogical and elemental compositions of the martian soil are indicators of chemical and physical weathering processes. Using data from the Mars Exploration Rovers, we show that bright dust deposits on opposite sides of the planet are part of a global unit and not dominated by the composition of local rocks. Dark soil deposits at both sites have similar basaltic mineralogies, and could reflect either a global component or the general similarity in the compositions of the rocks from which they were derived. Increased levels of bromine are consistent with mobilization of soluble salts by thin films of liquid water, but the presence of olivine in analysed soil samples indicates that the extent of aqueous alteration of soils has been limited. Nickel abundances are enhanced at the immediate surface and indicate that the upper few millimetres of soil could contain up to one per cent meteoritic material. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Max Planck Inst Chem, D-55128 Mainz, Germany. Johannes Gutenberg Univ Mainz, D-55128 Mainz, Germany. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Lockheed Martin Corp, Littleton, CO 80127 USA. Washington Univ, St Louis, MO 63130 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Co Vale Rio Doce, BR-29030900 Rio De Janeiro, Brazil. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Univ Copenhagen, Niels Bohr Inst, DS-2100 Copenhagen, Denmark. DLR, Inst Raumsimulat, D-51170 Cologne, Germany. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Albert.Yen@jpl.nasa.gov RI Schroder, Christian/B-3870-2009; de Souza, Paulo/B-8961-2008; Hurowitz, Joel/A-8862-2008; Madsen, Morten/D-2082-2011; Johnson, Jeffrey/F-3972-2015; Crisp, Joy/H-8287-2016 OI Schroder, Christian/0000-0002-7935-6039; de Souza, Paulo/0000-0002-0091-8925; Madsen, Morten/0000-0001-8909-5111; Crisp, Joy/0000-0002-3202-4416 NR 47 TC 194 Z9 195 U1 12 U2 68 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD JUL 7 PY 2005 VL 436 IS 7047 BP 49 EP 54 DI 10.1038/nature03637 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 942QJ UT WOS:000230296600036 PM 16001059 ER PT J AU Bell, JF Lemmon, MT Duxbury, TC Hubbard, MYH Wolff, MJ Squyres, SW Craig, L Ludwinski, JM AF Bell, JF Lemmon, MT Duxbury, TC Hubbard, MYH Wolff, MJ Squyres, SW Craig, L Ludwinski, JM TI Solar eclipses of Phobos and Deimos observed from the surface of Mars SO NATURE LA English DT Article ID SATELLITES; LOCALIZATION; SPACECRAFT; ORBITS AB The small martian satellites Phobos and Deimos orbit in synchronous rotation with inclinations of only 0.01 degrees and 0.92 degrees, respectively, relative to the planet's equatorial plane. Thus, an observer at near-equatorial latitudes on Mars could occasionally observe solar eclipses by these satellites (see ref. 1, for example). Because the apparent angular diameter of the satellites is much smaller than that of the Sun, however, such events are more appropriately referred to as transits. Transit data can be used for correcting and refining the orbital ephemerides of the moons. For example, Phobos is known to exhibit a secular acceleration that is caused by tidal dissipation within Mars(2-4). Long-term, accurate measurements are needed to refine the magnitude and origin of this dissipation within the martian interior as well as to refine the predicted orbital evolution of both satellites(5,6). Here we present observations of six transits of Phobos and Deimos across the solar disk from cameras on Mars aboard the Mars Exploration Rovers Spirit and Opportunity(7,8). These are the first direct imaging observations of satellites transiting the Sun from the surface of another planet. C1 Cornell Univ, Ithaca, NY 14853 USA. Texas A&M Univ, College Stn, TX 77843 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Space Sci Inst, Boulder, CO 80301 USA. RP Cornell Univ, Ithaca, NY 14853 USA. EM jfb8@cornell.edu RI Lemmon, Mark/E-9983-2010 OI Lemmon, Mark/0000-0002-4504-5136 NR 16 TC 15 Z9 16 U1 1 U2 3 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD JUL 7 PY 2005 VL 436 IS 7047 BP 55 EP 57 DI 10.1038/nature03437 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 942QJ UT WOS:000230296600037 PM 16001060 ER PT J AU Sullivan, R Banfield, D Bell, JF Calvin, W Fike, D Golombek, M Greeley, R Grotzinger, J Herkenhoff, K Jerolmack, D Malin, M Ming, D Soderblom, LA Squyres, SW Thompson, S Watters, WA Weitz, CM Yen, A AF Sullivan, R Banfield, D Bell, JF Calvin, W Fike, D Golombek, M Greeley, R Grotzinger, J Herkenhoff, K Jerolmack, D Malin, M Ming, D Soderblom, LA Squyres, SW Thompson, S Watters, WA Weitz, CM Yen, A TI Aeolian processes at the Mars Exploration Rover Meridiani Planum landing site SO NATURE LA English DT Article ID WIND STREAKS; DUST; EARTH; SPECTROMETER; OPPORTUNITY; TRANSPORT; SURFACES; VENUS; SOILS AB The martian surface is a natural laboratory for testing our understanding of the physics of aeolian (wind-related) processes in an environment different from that of Earth. Martian surface markings and atmospheric opacity are time-variable, indicating that fine particles at the surface are mobilized regularly by wind(1-3). Regolith (unconsolidated surface material) at the Mars Exploration Rover Opportunity's landing site has been affected greatly by wind, which has created and reoriented bedforms, sorted grains, and eroded bedrock. Aeolian features here preserve a unique record of changing wind direction and wind strength. Here we present an in situ examination of a martian bright wind streak, which provides evidence consistent with a previously proposed formational model(4,5) for such features. We also show that a widely used criterion for distinguishing between aeolian saltation- and suspension-dominated grain behaviour is different on Mars, and that estimated wind friction speeds between 2 and 3 ms(-1), most recently from the northwest, are associated with recent global dust storms, providing ground truth for climate model predictions. C1 Cornell Univ, Ctr Radiophys & Space Res, Dept Astron, Ithaca, NY 14853 USA. Univ Nevada, Reno, NV 89557 USA. MIT, Cambridge, MA 02139 USA. Jet Prop Lab, Pasadena, CA 90119 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Malin Space Sci Syst, San Diego, CA 92191 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Planetary Sci Inst, Tucson, AZ 85719 USA. RP Sullivan, R (reprint author), Cornell Univ, Ctr Radiophys & Space Res, Dept Astron, Ithaca, NY 14853 USA. EM rjs33@cornell.edu RI Fike, David/D-3634-2011; OI Fike, David/0000-0003-2848-0328; Banfield, Don/0000-0003-2664-0164 NR 27 TC 118 Z9 121 U1 3 U2 29 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUL 7 PY 2005 VL 436 IS 7047 BP 58 EP 61 DI 10.1038/nature03641 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 942QJ UT WOS:000230296600038 PM 16001061 ER PT J AU Goetz, W Bertelsen, P Binau, CS Gunnlaugsson, HP Hviid, SF Kinch, KM Madsen, DE Madsen, MB Olsen, M Gellert, R Klingelhofer, G Ming, DW Morris, RV Rieder, R Rodionov, DS de Souza, PA Schroder, C Squyres, SW Wdowiak, T Yen, A AF Goetz, W Bertelsen, P Binau, CS Gunnlaugsson, HP Hviid, SF Kinch, KM Madsen, DE Madsen, MB Olsen, M Gellert, R Klingelhofer, G Ming, DW Morris, RV Rieder, R Rodionov, DS de Souza, PA Schroder, C Squyres, SW Wdowiak, T Yen, A TI Indication of drier periods on Mars from the chemistry and mineralogy of atmospheric dust SO NATURE LA English DT Article ID MAGNETIC-PROPERTIES EXPERIMENTS; X-RAY SPECTROMETER; GUSEV CRATER; MOSSBAUER SPECTROMETER; MERIDIANI-PLANUM; SPIRIT; PATHFINDER; ROVERS; SPECTROSCOPY; OPPORTUNITY AB The ubiquitous atmospheric dust on Mars is well mixed by periodic global dust storms, and such dust carries information about the environment in which it once formed and hence about the history of water on Mars(1). The Mars Exploration Rovers have permanent magnets to collect atmospheric dust for investigation by instruments on the rovers(2,3). Here we report results from Mossbauer spectroscopy and X-ray fluorescence of dust particles captured from the martian atmosphere by the magnets. The dust on the magnets contains magnetite and olivine; this indicates a basaltic origin of the dust and shows that magnetite, not maghemite, is the mineral mainly responsible for the magnetic properties of the dust. Furthermore, the dust on the magnets contains some ferric oxides, probably including nanocrystalline phases, so some alteration or oxidation of the basaltic dust seems to have occurred. The presence of olivine indicates that liquid water did not play a dominant role in the processes that formed the atmospheric dust. C1 Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus, Denmark. Max Planck Inst Chem, D-55128 Mainz, Germany. Univ Mainz, Inst Anorgan & Analyt Chem, D-55128 Mainz, Germany. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Space Res Inst IKI, Moscow, Russia. Co Vale Rio Doce, BR-29090900 Vitoria, ES, Brazil. Cornell Univ, Ithaca, NY 14853 USA. Univ Alabama, Birmingham, AL 35203 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Goetz, W (reprint author), Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. EM goetz@mps.mpg.de RI de Souza, Paulo/B-8961-2008; Schroder, Christian/B-3870-2009; Madsen, Morten/D-2082-2011; Kinch, Kjartan/C-5742-2015 OI de Souza, Paulo/0000-0002-0091-8925; Schroder, Christian/0000-0002-7935-6039; Madsen, Morten/0000-0001-8909-5111; Kinch, Kjartan/0000-0002-4629-8880 NR 23 TC 75 Z9 76 U1 4 U2 17 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUL 7 PY 2005 VL 436 IS 7047 BP 62 EP 65 DI 10.1038/nature03807 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 942QJ UT WOS:000230296600039 PM 16001062 ER PT J AU Haskin, LA Wang, A Jolliff, BL McSween, HY Clark, BC Des Marais, DJ McLennan, SM Tosca, NJ Hurowitz, JA Farmer, JD Yen, A Squyres, SW Arvidson, RE Klingelhofer, G Schroder, C de Souza, PA Ming, DW Gellert, R Zipfel, J Bruckner, J Bell, JF Herkenhoff, K Christensen, PR Ruff, S Blaney, D Gorevan, S Cabrol, NA Crumpler, L Grant, J Soderblom, L AF Haskin, LA Wang, A Jolliff, BL McSween, HY Clark, BC Des Marais, DJ McLennan, SM Tosca, NJ Hurowitz, JA Farmer, JD Yen, A Squyres, SW Arvidson, RE Klingelhofer, G Schroder, C de Souza, PA Ming, DW Gellert, R Zipfel, J Bruckner, J Bell, JF Herkenhoff, K Christensen, PR Ruff, S Blaney, D Gorevan, S Cabrol, NA Crumpler, L Grant, J Soderblom, L TI Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater SO NATURE LA English DT Article ID MINERALOGY; SPECTROMETER; CHEMISTRY; DEPOSITS AB Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments(1). However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and windblown 'global' dust(2). The analyses of three rock interiors exposed by the rock abrasion tool showed that they are similar to one another, consistent with having originated from a common lava flow(3-8). Here we report the investigation of soils, rock coatings and rock interiors by the Spirit rover from sol (martian day) 1 to sol 156, from its landing site to the base of the Columbia hills. The physical and chemical characteristics of the materials analysed provide evidence for limited but unequivocal interaction between water and the volcanic rocks of the Gusev plains. This evidence includes the softness of rock interiors that contain anomalously high concentrations of sulphur, chlorine and bromine relative to terrestrial basalts and martian meteorites(9); sulphur, chlorine and ferric iron enrichments in multilayer coatings on the light-toned rock Mazatzal; high bromine concentration in filled vugs and veins within the plains basalts; positive correlations between magnesium, sulphur and other salt components in trench soils; and decoupling of sulphur, chlorine and bromine concentrations in trench soils compared to Gusev surface soils, indicating chemical mobility and separation. C1 Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. Lockheed Martin Space Syst, Littleton, CO 80125 USA. NASA, Exobiol Branch, Ames Res Ctr, Moffett Field, CA 94035 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Cornell Univ, Ithaca, NY 14853 USA. Johannes Gutenberg Univ Mainz, Inst Anorgan & Analyt Chem, D-55128 Mainz, Germany. Co Vale Rio Doce, BR-20030900 Rio De Janeiro, Brazil. NASA, Lyndon B Johnson Space Ctr, MC KR, Houston, TX 77058 USA. Max Planck Inst Chem, Abt Kosmochem, D-55128 Mainz, Germany. US Geol Survey, Flagstaff, AZ 86001 USA. Honeybee Robot, New York, NY 10012 USA. NASA, SETI Inst, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Div Space Sci, Ames Res Ctr, Moffett Field, CA 94035 USA. New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA. Smithsonian Inst, Washington, DC 20024 USA. RP Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. EM alianw@levee.wustl.edu RI Hurowitz, Joel/A-8862-2008; de Souza, Paulo/B-8961-2008; Schroder, Christian/B-3870-2009 OI de Souza, Paulo/0000-0002-0091-8925; Schroder, Christian/0000-0002-7935-6039 NR 27 TC 147 Z9 150 U1 3 U2 25 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD JUL 7 PY 2005 VL 436 IS 7047 BP 66 EP 69 DI 10.1038/nature03640 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 942QJ UT WOS:000230296600040 PM 16001063 ER PT J AU Shevade, AV Ryan, MA Homer, ML Kisor, AK Manatt, KS Lin, B Fleurial, JP Manfreda, AM Yen, SPS AF Shevade, AV Ryan, MA Homer, ML Kisor, AK Manatt, KS Lin, B Fleurial, JP Manfreda, AM Yen, SPS TI Calorimetric measurements of heat of sorption in polymer films: A molecular modeling and experimental study SO ANALYTICA CHIMICA ACTA LA English DT Article DE molecular modeling; polymer film; heat of sorption; micro-calorimeters; quartz crystal microbalance/heat conducting calorimeter ID MICROBALANCE/HEAT CONDUCTION CALORIMETER; ISOTHERMAL MICROCALORIMETRY; AROMATIC LIQUIDS; THERMAL-ANALYSIS; ELECTRONIC NOSE; SIMULATIONS; TEMPERATURE; DIFFUSION; 50-DEGREES-C; INSTRUMENT AB We report a combined molecular modeling and experimental effort to predict and measure the heat of sorption of target molecules in a polymer film. The primary focus of this work is to demonstrate and validate the applicability of molecular modeling techniques as a predictive tool to evaluate polymeric sensing films for micro-calorimetric chemical sensor applications. In the current investigation, molecular modeling studies were performed prior to experimental measurements to predict the heat of sorption (Delta H-sorpt) of a target analyte in a polymer film. Experimental measurements for the heat of sorption were performed using a quartz crystal microbalance/heat conducting calorimeter setup. The system under investigation was isopropanol in ethyl cellulose polymer film. The average Delta H-sorpt predicted by molecular modeling at 22 degrees C was found to be 39.7 kJ/mol (standard deviation = 2.6 kJ/mol), which compares well with the average measured experimental value of 30.2 kJ/mol (standard deviation = 7.2 kJ/mol). (c) 2005 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shevade, AV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM abhijit.shevade@jpl.nasa.gov OI Lin, Binshan/0000-0002-8481-302X NR 38 TC 2 Z9 2 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD JUL 6 PY 2005 VL 543 IS 1-2 BP 242 EP 248 DI 10.1016/j.aca.2005.04.036 PG 7 WC Chemistry, Analytical SC Chemistry GA 937VF UT WOS:000229953300033 ER PT J AU Kawa, SR Newman, PA Stolarski, RS Bevilacqua, RM AF Kawa, SR Newman, PA Stolarski, RS Bevilacqua, RM TI Fall vortex ozone as a predictor of springtime total ozone at high northern latitudes SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID POLAR VORTEX; INTERANNUAL VARIABILITY; STRATOSPHERE; PROFILES; VALIDATION; WINTERS; TRENDS; CIRCULATION; HEMISPHERE; DEPLETION AB Understanding the impact of atmospheric dynamical variability on observed changes in stratospheric O-3 is a key to understanding how O-3 will change with future climate dynamics and trace gas abundances. In this paper we examine the linkage between interannual variability in total column O-3 at northern high latitudes in March and lower-to-mid stratospheric vortex O-3 in the prior November. We find that these two quantities are significantly correlated in the years available from TOMS, SBUV, and POAM data ( 1978 2004). Additionally, we find that the increase in March O-3 variability from the 1980s to years post- 1990 is also seen in the November vortex O-3, i.e., interannual variability in both quantities is much larger in the later years. The cause of this correlation is not clear, however. Interannual variations in March total O-3 are known to correspond closely with variations in winter stratospheric wave driving consistent with the effects of varying residual circulation, temperature, and chemical loss. Variation in November vortex O-3 may also depend on dynamical wave activity, but the dynamics in fall are less variable than in winter and spring. We do not find significant correlations of dynamic indicators for November such as temperature, heat flux, or polar average total O-3 with the November vortex O-3, nor with dynamical indicators later in winter and spring that might lead to a connection to March. We discuss several potential hypotheses for the observed correlation but do not find strong evidence for any considered mechanism. We present the observations as a phenomenon whose understanding may improve our ability to predict the dependence of O-3 on changing dynamics and chemistry. C1 NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. USN, Res Lab, Washington, DC 20375 USA. RP Kawa, SR (reprint author), NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. EM kawa@maia.gsfc.nasa.gov RI Newman, Paul/D-6208-2012; Kawa, Stephan/E-9040-2012; Stolarski, Richard/B-8499-2013 OI Newman, Paul/0000-0003-1139-2508; Stolarski, Richard/0000-0001-8722-4012 NR 39 TC 8 Z9 8 U1 0 U2 2 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JUL 4 PY 2005 VL 5 BP 1655 EP 1663 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 942RV UT WOS:000230300400001 ER PT J AU Cook, RA AF Cook, RA TI The Mars exploration rover project SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB The twin rovers of the Mars exploration rover project successfully landed on the surface of Mars in January 2004, and initiated a highly successful science and exploration campaign. This marked the culmination of an unprecedented 4-year effort to design, build, launch, and operate two of the most complex planetary spacecraft ever built. The project was started in the aftermath of the 1999 Mars mission failures, and was commissioned to take advantage of the highly advantageous 2003 opportunity. The development schedule from project start to launch was only 35 months, so schedule management was the most significant challenge facing the project. This problem was compounded when early assumptions about the extent of design heritage from Mars Pathfinder proved to be flawed. The project derived a number of useful lessons learned in solving these challenges that can be applied to future missions. (c) 2005 Published by Elsevier Ltd. C1 CALTECH, Jet Propuls Lab, Mars Explorat Rover Project, Pasadena, CA 91125 USA. RP Cook, RA (reprint author), CALTECH, Jet Propuls Lab, Mars Explorat Rover Project, Pasadena, CA 91125 USA. NR 0 TC 2 Z9 2 U1 1 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 116 EP 120 DI 10.1016/j.actaastro.2005.03.008 PG 5 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900009 ER PT J AU Shotwell, R AF Shotwell, R TI Phoenix - the first Mars Scout mission SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB NASA has initiated the first of a new series of missions to augment the current Mars Program. In addition to the systematic series of planned, directed missions currently comprising the Mars Program plan, NASA has started a series of Mars Scout missions that are low cost, price fixed, Principle Investigator-led projects. These missions are intended to provide an avenue for rapid response to discoveries made as a result of the primary Mars missions, as well as allow more risky technologies and approaches to be applied in the investigation of Mars. The first in this new series is the Phoenix mission which was selected as part of a highly competitive process. Phoenix will use the Mars 2001 Lander that was discontinued in 2000 and apply a new set of science objectives and mission objectives and will validate this soft lander architecture for future applications. This paper will provide an overview of both the Program and the Project. (c) 2005 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Shotwell, R (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. EM Robert.Shotwell@jpl.nasa.gov NR 3 TC 23 Z9 24 U1 1 U2 5 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 121 EP 134 DI 10.1016/j.actaastro.2005.03.038 PG 14 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900010 PM 16010756 ER PT J AU McNelis, AM Heese, JA Samorezov, S Moss, LA Just, ML AF McNelis, AM Heese, JA Samorezov, S Moss, LA Just, ML TI Ground based ISS payload microgravity disturbance assessments SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB In order to verify that the International Space Station (ISS) payload facility racks do not disturb the microgravity environment of neighboring facility racks and that the facility science operations are not compromised, a testing and analytical verification process must be followed. Currently no facility racks have taken this process from start to finish. The authors are participants in implementing this process for the NASA Glenn Research Center (GRC) Fluids and Combustion Facility (FCF). To address the testing part of the verification process, the Microgravity Emissions Laboratory (MEL) was developed at GRC. The MEL is a 6 degree of freedom inertial measurement system capable of characterizing inertial response forces (emissions) of components, sub-rack payloads, or rack-level payloads down to 10(-7) g's. The inertial force output data, generated from the steady state or transient operations of the test articles, are utilized in analytical simulations to predict the on-orbit vibratory environment at specific science or rack interface locations. Once the facility payload rack and disturbers are properly modeled an assessment can be made as to whether required microgravity levels are achieved. The modeling is utilized to develop microgravity predictions which lead to the development of microgravity sensitive ISS experiment operations once on-orbit. The on-orbit measurements will be verified by use of the NASA GRC Space Acceleration Measurement System (SAMS). The major topics to be addressed in this paper are: (1) Microgravity Requirements, (2) Microgravity Disturbers, (3) MEL Testing, (4) Disturbance Control, (5) Microgravity Control Process, and (6) On-Orbit Predictions and Verification. Published by Elsevier Ltd. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. ZIN Technol Inc, Brookpark, OH 44142 USA. RP McNelis, AM (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Anne.M.McNelis@nasa.gov; John.Heese@zin-tech.com; Sergey.Samorezov@zin-tech.com; Larry.Moss@zin-tech.com; Marcus.Just@zin-tech.com NR 10 TC 2 Z9 2 U1 0 U2 1 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 205 EP 214 DI 10.1016/j.actaastro.2005.03.047 PG 10 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900019 PM 16010759 ER PT J AU McClinton, CR Rausch, VL Nguyen, LT Sitz, JR AF McClinton, CR Rausch, VL Nguyen, LT Sitz, JR TI Preliminary X-43 flight test results SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB The successful Mach 7 flight test of the Hyper-X/X-43 research vehicle has provided a major, essential demonstration of the capability of the airframe integrated scramjet engine. This flight was a crucial first step toward establishing the potential for air-breathing hypersonic propulsion for application to space-launch vehicles. (c) 2005 Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP McClinton, CR (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. EM Charles.R.Mcclinton@nasa.gov NR 6 TC 8 Z9 16 U1 2 U2 16 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 266 EP 276 DI 10.1016/j.actaastro.2005.03.060 PG 11 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900026 ER PT J AU Liou, JC Johnson, NL AF Liou, JC Johnson, NL TI A LEO satellite postmission disposal study using LEGEND SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress (IAF) CY OCT 04-08, 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB This paper summarizes results from two postmission disposal (PMD) parametric analyses based on the high fidelity NASA orbital debris evolutionary model LEGEND. The first analysis includes a non-mitigation reference scenario and four test scenarios, where the mission lifetimes of spacecraft are set to 5, 10, 20, and 30 years, respectively, before they are moved to the 25-year decay orbits. The comparison among the five scenarios quantifies how a prolonged spacecraft mission lifetime decreases the effectiveness of the 25-year decay rule in the low Earth orbit region (LEO). The second analysis includes three 25-year decay PMD scenarios where the mission lifetimes of spacecraft are set to 5 years but with disposal success rates set to 50 %, 70 %, and 90 %, respectively. It illustrates how the PMD success rate impacts the long-term debris environment. The conclusion of this paper is that a prolonged spacecraft mission lifetime and a lower PMD success rate can have noticeable negative impact on the debris environment in the long run. (c) 2005 Elsevier Ltd. All rights reserved. C1 Lockheed Martin Space Operat, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Liou, JC (reprint author), Lockheed Martin Space Operat, Houston, TX 77058 USA. EM jer-chyi.liou1@jsc.nasa.gov; nicholas.l.johnson@nasa.gov NR 6 TC 7 Z9 7 U1 0 U2 1 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 324 EP 329 DI 10.1016/j.actaastro.2005.03.002 PG 6 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900031 ER PT J AU Fiehler, D Oleson, S AF Fiehler, D Oleson, S TI Radioisotope electric propulsion missions utilizing a common spacecraft design SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB A study was conducted that shows how a single radioisotope electric propulsion (REP) spacecraft design could be used for various missions throughout the solar system. This spacecraft design is based on an REP feasibility design from a study performed by NASA Glenn Research Center and the Johns Hopkins University Applied Physics Laboratory. The study also identifies technologies that need development to enable these missions. The mission baseline for the REP feasibility design study is a Trojan asteroid orbiter. This mission sends an REP spacecraft to Jupiter's leading Lagrange point where it would orbit and examine several Trojan asteroids. The spacecraft design from the REP feasibility study would also be applicable to missions to the Centaurs, and through some change of payload configuration could accommodate a comet sample-return mission. Missions to small bodies throughout the outer solar system are also within reach of this spacecraft design. This set of missions, utilizing the common REP spacecraft design, is examined, and required design modifications for specific missions are outlined. (c) 2005 Elsevier Ltd. All rights reserved. C1 NASA, QSS Grp Inc, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Fiehler, D (reprint author), NASA, QSS Grp Inc, Glenn Res Ctr, 21000 Brookpk Rd,MS 301-3, Cleveland, OH 44135 USA. EM Douglas.I.Fichler@grc.nasa.gov; Steven.R.Oleson@nasa.gov NR 25 TC 4 Z9 4 U1 0 U2 1 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 444 EP 454 DI 10.1016/j.actaastro.2005.03.044 PG 11 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900044 ER PT J AU Curto, PA Hornstein, RS AF Curto, PA Hornstein, RS TI Injection of new technology into space systems SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat ID EMPIRICAL MODE DECOMPOSITION; HUANG SPECTRAL-ANALYSIS; IDENTIFICATION AB Small satellite systems appear to be antithetical to human spaceflight systems and flagship robotic satellite systems: Small satellite missions have more focused scientific objectives, lower cost, far less complexity, and shorter development and deployment schedules. The shorter schedules offer an opportunity for injecting new technology into their design as a means for keeping costs and schedule under control, for enabling cost-effective operations, and for taking advantage of innovative ideas. It is often the case that small satellite missions benefit from technologies specifically targeted for their application, but benefits may also be realized by adopting or injecting technologies originally developed for human spaceflight systems, especially if these technologies were conceived using multi-use and multi-disciplinary development principles. In this paper, the authors discuss the precedent of injecting new technology developed for human spaceflight systems into small satellite missions. More importantly, the authors will present five new technologies recently proposed for making the NASA Space Shuttle safer to fly, all of which are directly applicable to small satellite mission design and operations. The technologies, when matured, will provide a means to create new generations of ultra-reliable flight hardware and software. The technologies are all currently at the developmental phase and require modest investment to achieve operational status. Published by Elsevier Ltd. C1 NASA, Washington, DC 20546 USA. RP Curto, PA (reprint author), NASA, Washington, DC 20546 USA. EM paul.a.curto@nasa.gov; rhoda.s.hornstein@nasa.gov NR 25 TC 0 Z9 0 U1 0 U2 5 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 490 EP 497 DI 10.1016/j.actaastro.2005.03.009 PG 8 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900048 ER PT J AU Graf, JE Zurek, RW Eisen, HJ Jai, B Johnston, MD DePaula, R AF Graf, JE Zurek, RW Eisen, HJ Jai, B Johnston, MD DePaula, R TI The Mars Reconnaissance Orbiter Mission SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB The Mars Reconnaissance Orbiter (MRO) will be launched in August 2005 by an Atlas V 401 expendable launch vehicle from Cape Canaveral Air Force Station, USA. It will deliver to Mars orbit a payload to conduct remote sensing science observations, identify and characterize sites for future landers, and provide critical telecom/navigation relay capability for follow-on missions. The mission is designed to provide global, regional survey, and targeted observations from a low 255 km by 320km Mars orbit with a 3:00 PM local mean solar time (ascending node). During the one Martian year (687 Earth days) primary science phase, the orbiter will acquire visual and near-infrared high-resolution images of the planet's surface, monitor atmospheric weather and climate, and search the upper crust for evidence of water. After this science phase is completed, the orbiter will provide telecommunications support for spacecraft launched to Mars in the 2007 and 2009 opportunities. The primary mission ends on December 31, 2010, approximately 5.5 years after launch. (c) 2005 Published by Elsevier Ltd. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Graf, JE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jegraf@jpl.nasa.gov NR 2 TC 17 Z9 19 U1 0 U2 6 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 566 EP 578 DI 10.1016/j.actaastro.2005.03.043 PG 13 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900056 ER PT J AU Kitmacher, GH Gerstenmaier, WH Bartoe, JDF Mustachio, N AF Kitmacher, GH Gerstenmaier, WH Bartoe, JDF Mustachio, N TI The international space station: A pathway to the future SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB Nearly six years after the launch of the first International Space Station element, and four years after its initial occupation, the United States and our 6 international partners have made great strides in operating this impressive Earth orbiting research facility. This past year we have done so in the face of the adversity of operating without the benefit of the Space Shuttle. In his January 14, 2004, speech announcing a new vision for America's space program, President Bush affirmed the United States' commitment to completing construction of the International Space Station by 2010. The President also stated that we would focus our future research aboard the Station on the long-term effects of space travel on human biology. This research will help enable human crews to venture through the vast voids of space for months at a time. In addition, ISS affords a unique opportunity to serve as an engineering test bed for hardware and operations critical to the exploration tasks. NASA looks forward to working with our partners on International Space Station research that will help open up new pathways for future exploration and discovery beyond low Earth orbit. This paper provides an overview of the International Space Station Program focusing on a review of the events of the past year, as well as plans for next year and the future. Published by Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Kitmacher, GH (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 0 TC 3 Z9 5 U1 0 U2 5 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 594 EP 603 DI 10.1016/j.actaacstro.2005.03.027 PG 10 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900058 PM 16010761 ER PT J AU McClinton, CR Rausch, VL Shaw, RJ Metha, U Naftel, C AF McClinton, CR Rausch, VL Shaw, RJ Metha, U Naftel, C TI Hyper-X: Foundation for future hypersonic launch vehicles SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB The successful Mach-7 flight test of the Hyper-X/X-43A research vehicle has provided a major, essential demonstration of the capability of the airframe-integrated scramjet engine and hypersonic airbreathing vehicle design tools and vision vehicles. This flight was a crucial step toward establishing air-breathing hypersonic propulsion for application to space-launch vehicles and other hypersonic systems. This paper examines the significance of the flight test in advancing the state-of-the science and provides a strategic vision for achieving the dream for safe, efficient and reliable space access with air-breathing propulsion in the near future, through use of more near term approaches. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP McClinton, CR (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. EM Charles.R.Mcclinton@nasa.gov NR 11 TC 9 Z9 12 U1 2 U2 23 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 614 EP 622 DI 10.1016/j.actaastro.2005.03.061 PG 9 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900060 ER PT J AU Hubbard, GS AF Hubbard, GS TI Humans and robots: Hand in grip SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB As we move boldly forward into the 21st century, there has rarely been a more exciting time in which to contemplate the future of space exploration. The President of the United States has made a new and ambitious commitment to exploration of the solar system and beyond. Robotic partners will play a vital role in ensuring that the Vision is truly "sustainable and affordable". Relevant science and technology will be discussed with particular emphasis on expertise from NASA Ames Research Center of which the author is Director. The likely evolution of the balance between human explorers and robotic explorers will be addressed. (c) 2005 Published by Elsevier Ltd. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hubbard, GS (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM G.Scott.Hubbard@nasa.gov NR 11 TC 2 Z9 2 U1 0 U2 2 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 649 EP 660 DI 10.1016/j.actaastro.2005.03.054 PG 12 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900065 PM 16010764 ER PT J AU Mendell, WW AF Mendell, WW TI Meditations on the new space vision: The moon as a stepping stone to mars SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 55th International-Astronautical-Federation Congress CY 2004 CL Vancouver, CANADA SP Int Astronaut Federat AB The Vision for Space Exploration invokes activities on the Moon in preparation for exploration of Mars and also directs International Space Station (ISS) research toward the same goal. Lunar missions will emphasize development of capability and concomitant reduction of risk for future exploration of Mars. Earlier papers identified three critical issues related to the so-called NASA Mars Design Reference Mission (MDRM) to be addressed in the lunar context: (a) safety, health, and performance of the human crew; (b) various modalities of mission operations ranging surface activities to logistics, planning, and navigation; and (c) reliability and maintainability of systems in the planetary environment. In simple terms, lunar expeditions build a resume that demonstrates the ability to design, construct, and operate an enterprise such as the MDRM with an expectation of mission success. We can evolve from Apollo-like missions to ones that resemble the complexity and duration of the MDRM. Investment in lunar resource utilization technologies falls naturally into the Vision. NASA must construct an exit strategy from the Moon in the third decade. With a mandate for continuing exploration, it cannot assume responsibility for long-term operation of lunar assets. Therefore, NASA must enter into a partnership with some other entity-governmental, international, or commercial-that can responsibly carry on lunar development past the exploration phase. Published by Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Mendell, WW (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM wendell.w.mendell@nasa.gov NR 13 TC 6 Z9 6 U1 1 U2 2 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 JUL-OCT PY 2005 VL 57 IS 2-8 BP 676 EP 683 DI 10.1016/j.actaastro.2005.03.024 PG 8 WC Engineering, Aerospace SC Engineering GA 938QM UT WOS:000230017900067 PM 16010766 ER PT J AU Chen, B Cinke, M Li, JZ Meyyappan, M Chi, ZH Harmon, JP Muisener, PAO Clayton, L D'Angelo, J AF Chen, B Cinke, M Li, JZ Meyyappan, M Chi, ZH Harmon, JP Muisener, PAO Clayton, L D'Angelo, J TI Modifying the electronic character of single-walled carbon nanotubes through anisotropic polymer interaction: A Raman study SO ADVANCED FUNCTIONAL MATERIALS LA English DT Article ID COMPOSITES; SCATTERING AB Using Raman spectroscopy, we demonstrate that the anisotropic interaction between single-walled carbon nanotubes (SWNTs) and poly(methyl methacrylate) (PMMA) causes significant changes in the electronic properties of their composites. Two different procedures were used to prepare the composites: melt blending and in-situ UV polymerization. Resonant Raman studies relate the electronic density of states (DOS) of the SWNTs to the corresponding vibration symmetry changes of both the PMMA and the SWNTs. Our results show that, in the melt-blended sample, the SWNTs-originally semiconducting-became predominantly metallic. The changes in the electronic properties were also confirmed by dielectric constant measurements. We propose that the anisotropic interaction between PMMA and SWNTs in the melt-blended composite is the dominant reason for the observed electronic character change. C1 NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Comp Sci Corp, Moffett Field, CA 94035 USA. Renishaw Inc, Hoffman Estates, IL 60912 USA. Univ S Florida, Dept Chem, Tampa, FL 33620 USA. RP Chen, B (reprint author), NASA, Ames Res Ctr, ELORET Corp, MS 245-3, Moffett Field, CA 94035 USA. EM bchen@mail.arc.nasa.gov NR 29 TC 9 Z9 9 U1 1 U2 7 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1616-301X J9 ADV FUNCT MATER JI Adv. Funct. Mater. PD JUL PY 2005 VL 15 IS 7 BP 1183 EP 1187 DI 10.1002/adfm.200305027 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 948RT UT WOS:000230734100018 ER PT J AU Kinzie, KW Schein, DB Solomon, WD AF Kinzie, KW Schein, DB Solomon, WD TI Experiments and analyses of distributed exhaust nozzles SO AIAA JOURNAL LA English DT Article AB Experimental and analytical aeroacoustic properties of several distributed exhaust nozzle (DEN) designs are presented. Significant differences between the designs are observed and correlated to computational fluid dynamics flowfield predictions. Up to 20 dB of noise reduction on a spectral basis and 10 dB on an overall sound pressure level basis are demonstrated from the DEN designs compared to a round reference nozzle. The most successful DEN designs acoustically show a predicted thrust loss of approximately 10% compared to the reference nozzle. Characteristics of the individual minijet nozzles that comprise the DEN such as jet-jet shielding and coalescence are shown to play a major role in the noise signature. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Northrop Grumman Integrated Syst, El Segundo, CA 90245 USA. RP Kinzie, KW (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD JUL PY 2005 VL 43 IS 7 BP 1476 EP 1481 DI 10.2514/1.14550 PG 6 WC Engineering, Aerospace SC Engineering GA 942GZ UT WOS:000230272200008 ER PT J AU Searby, ND Steele, CR Globus, RK AF Searby, ND Steele, CR Globus, RK TI Influence of increased mechanical loading by hypergravity on the microtubule cytoskeleton and prostaglandin E-2 release in primary osteoblasts SO AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY LA English DT Article DE mechanotransduction; differentiation; bone ID SIGNAL-TRANSDUCTION PATHWAYS; MINERALIZED BONE NODULES; FLUID SHEAR-STRESS; MC3T3-E1 OSTEOBLASTS; EXTRACELLULAR-MATRIX; CELLS MC3T3-E1; NITRIC-OXIDE; DIFFERENTIATION; STRAIN; FLOW AB Cells respond to a wide range of mechanical stimuli such as fluid shear and strain, although the contribution of gravity to cell structure and function is not understood. We hypothesized that bone-forming osteoblasts are sensitive to increased mechanical loading by hypergravity. A centrifuge suitable for cell culture was developed and validated, and then primary cultures of fetal rat calvarial osteoblasts at various stages of differentiation were mechanically loaded using hypergravity. We measured microtubule network morphology as well as release of the paracrine factor prostaglandin E-2 (PGE(2)). In immature osteoblasts, a stimulus of 10 x gravity ( 10 g) for 3 h increased PGE(2) 2.5-fold and decreased microtubule network height 1.12-fold without affecting cell viability. Hypergravity ( 3 h) caused dose-dependent ( 5 - 50 g) increases in PGE(2) (5.3-fold at 50 g) and decreases (1.26-fold at 50 g) in microtubule network height. PGE(2) release depended on duration but not orientation of the hypergravity load. As osteoblasts differentiated, sensitivity to hypergravity declined. We conclude that primary osteoblasts demonstrate dose- and duration-dependent sensitivity to gravitational loading, which appears to be blunted in mature osteoblasts. C1 NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. Univ Calif San Francisco, Dept Stomatol, San Francisco, CA 94143 USA. RP Searby, ND (reprint author), NASA, Ames Res Ctr, Div Life Sci, MS 236-7, Moffett Field, CA 94035 USA. EM nancy.d.searby@nasa.gov NR 51 TC 26 Z9 28 U1 1 U2 6 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0363-6143 J9 AM J PHYSIOL-CELL PH JI Am. J. Physiol.-Cell Physiol. PD JUL PY 2005 VL 289 IS 1 BP C148 EP C158 DI 10.1152/ajpcell.00524.2003 PG 11 WC Cell Biology; Physiology SC Cell Biology; Physiology GA 935PL UT WOS:000229794100018 PM 15728710 ER PT J AU Roy, AS Banerjee, RK Back, LH Back, MR Khoury, S Millard, RW AF Roy, AS Banerjee, RK Back, LH Back, MR Khoury, S Millard, RW TI Delineating the guide-wire flow obstruction effect in assessment of fractional flow reserve and coronary flow reserve measurements SO AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY LA English DT Article DE hemodynamics; stenosis; microvascular impairment; pressure drop ID TRANSSTENOTIC PRESSURE-GRADIENT; MYOCARDIAL BLOOD-FLOW; ARTERY STENOSES; PHYSIOLOGICAL SIGNIFICANCE; VELOCITY RESERVE; IN-VITRO; ANGIOPLASTY; HUMANS; SEVERITY; CATHETERIZATION AB Hemodynamic analysis was conducted to determine uncertainty in clinical measurements of coronary flow reserve (CFR) and fractional flow reserve (FFR) over pathophysiological conditions in a patient group with coronary artery disease during angioplasty. The vasodilation-distal perfusion pressure (CFR-(p) over tilde (rh)) curve was obtained for 0.35- and 0.46-mm guide wires. Our hypothesis is that a guide wire spanning the lesions elevates the pressure gradient and reduces the flow during hyperemic measurements. Maximal CFR-(p) over tilde rh was uniquely determined by the intersection of measured CFR and calculated (p) over tilde rh of native and residual epicardial lesions in patients without microvascular disease, during angioplasty. Extrapolation of the linear curve gave a zero-coronary flow mean pressure ((p) over tilde zf) of similar to 20 mmHg and a corresponding (p) over tilde rh of 55 mmHg in the native lesions, which coincided with the level that causes ischemia in human hearts. On this linear curve, values of CFR and FFRmyo (pathophysiological condition) and CFRg and FFRmyog (in the presence of the guide wire) were obtained in native and residual lesions. A strong linear correlation was found between CFR and CFRg [CFR=CFRg x 0.689+1.271 (R-2=0.99) for 0.46 mm and CFR=CFRg x 0.757+1.004 (R-2=0.99) for 0.35 mm] and between FFRmyo and FFRmyog [FFRmyo=FFRmyog x 0.737+0.263 (R-2=0.99) for 0.46 mm and FFRmyo=FFRmyog x 0.790+0.210 (R-2=0.99) for 0.35 mm]. This study establishes a strong correlation between CFR and CFRg and between FFRmyo and FFRmyog, which could be used to obtain the true state of occlusion in the coronary artery during angioplasty. C1 Univ S Florida, Coll Med, Div Vasc & Endovasc Surg, Tampa, FL USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Cincinnati, Dept Pharmacol & Cell Biophys, Cincinnati, OH USA. Univ Cincinnati, Dept Cardiol, Cardiac Catheterizat Lab, Cincinnati, OH USA. Univ Cincinnati, Dept Biomed Engn, Cincinnati, OH USA. Univ Cincinnati, Dept Mech Engn, Cincinnati, OH USA. RP Banerjee, RK (reprint author), Univ Cincinnati, Dept Mech Ind & Nucl Engn, 688 Rhodes Hall,POB 210072, Cincinnati, OH 45221 USA. EM rupak.banerjee@uc.edu NR 45 TC 24 Z9 25 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0363-6135 J9 AM J PHYSIOL-HEART C JI Am. J. Physiol.-Heart Circul. Physiol. PD JUL PY 2005 VL 289 IS 1 BP H392 EP H397 DI 10.1152/ajpheart.00798.2004 PG 6 WC Cardiac & Cardiovascular Systems; Physiology; Peripheral Vascular Disease SC Cardiovascular System & Cardiology; Physiology GA 935YA UT WOS:000229818100053 PM 15734887 ER PT J AU Bishop, JL Murad, E AF Bishop, JL Murad, E TI The visible and infrared spectral properties of jarosite and alunite SO AMERICAN MINERALOGIST LA English DT Article ID SOIL ANALOG MATERIALS; MERIDIANI-PLANUM; SULFATE MINERALS; REFLECTANCE SPECTROSCOPY; IMAGING SPECTROSCOPY; OPPORTUNITY ROVER; FERRIC IRON; MARS; SPECTROMETER; OXIDATION AB The visible and infrared spectral properties of two natural jarosite minerals and a suite of synthetic jarosites and alunite samples are described here. The fundamental stretching and bending vibrations observed in the infrared region for SO42- and OH- are compared with the near-infrared overtones and combinations of these vibrations. Shifts were observed in the SO42- and OH- bands for Al3+ vs. Fe3+ at the octahedral sites and K+ vs. Na+ at the "A" (frequently monovalent) sites. Crystal-field theory bands were observed for jarosite near 435, 650, and 900-925 nm and were compared to those of iron oxides. Spectral bands near 1.76, 2.17, 2.53, 4.5, 8-10, and 15-24 mu m (corresponding to similar to 5670, 4600, 3970-4150, 2100-2300, 1000-1225, and 420-675 cm(-1), respectively) for alunite and near 0.43, 0.91, 1.85, 2.27, 2.63, 4.9, 8-10, and 15-24 mu m (corresponding to similar to 23 000, 10 990, 5400, 4350-4520, 3800-4150, 1950-2200, 1000-1190, and 440-675 cm(-1), respectively) for jarosite would be most useful for detecting these minerals using remote sensing on Earth or Mars. These minerals are important indicators of alteration processes, and this study contributes toward combined visible/near-infrared and mid-infrared spectral detection of these two alunite-group minerals. C1 SETI Inst, Mountain View, CA 94043 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Bayer Geol Landesamt, D-95603 Marktredwitz, Germany. RP SETI Inst, 515 N Whisman Rd, Mountain View, CA 94043 USA. EM jbishop@mail.arc.nasa.gov NR 63 TC 107 Z9 109 U1 4 U2 29 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD JUL PY 2005 VL 90 IS 7 BP 1100 EP 1107 DI 10.2138/am.2005.1700 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 944GJ UT WOS:000230414500009 ER PT J AU Fishman, J AF Fishman, J TI Bursting with imagery SO AMERICAN SCIENTIST LA English DT Letter C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Fishman, J (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SIGMA XI-SCI RES SOC PI RES TRIANGLE PK PA PO BOX 13975, RES TRIANGLE PK, NC 27709 USA SN 0003-0996 J9 AM SCI JI Am. Scientist PD JUL-AUG PY 2005 VL 93 IS 4 BP 292 EP 293 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 934MT UT WOS:000229713600004 ER PT J AU Chiu, K Zheng, W Schneider, DP Glazebrook, K Iye, M Kashikawa, N Tsvetanov, Z Yoshida, M Brinkmann, J AF Chiu, K Zheng, W Schneider, DP Glazebrook, K Iye, M Kashikawa, N Tsvetanov, Z Yoshida, M Brinkmann, J TI The color selection of quasars from redshifts 5 to 10: Cloning and discovery SO ASTRONOMICAL JOURNAL LA English DT Article DE quasars : emission lines; quasars : general ID DIGITAL SKY SURVEY; SURVEY COMMISSIONING DATA; HUBBLE DEEP FIELDS; LUMINOSITY FUNCTION; DATA RELEASE; T-DWARFS; Z-GREATER-THAN-5.7 QUASARS; INFRARED PHOTOMETRY; ADDITIONAL QUASARS; SUBARU TELESCOPE AB We present simulations of quasar colors, magnitudes, and numbers at redshifts 5 < z < 10 based on our discovery of 10 new high-redshift quasars and the cloning of lower redshift Sloan Digital Sky Survey (SDSS) quasars. The 10 quasars have redshifts ranging from z = 4.7 to 5.3 and i magnitudes of 20.21 - 20.94. The natural diversity of spectral features in the cloned sample allows more realistic simulation of the quasar locus width than was previously possible with synthetic template spectra. Colors are generated for the z > 6 epoch, taking advantage of the new UKIRT Infrared Deep Sky Survey near-infrared filter set, and we examine the redshift intervals of maximum productivity, discussing color selection and survey depth issues. On the basis of the SDSS sample, we find that the surface density of z > 4: 7 quasars increases by a factor of 3 times by extending 0.7 i magnitudes deeper than the SDSS spectroscopic survey limit of i = 20.2; correspondingly, we predict a total of similar to 400 faint quasars in the SDSS main area that have redshift z > 4.7 and magnitudes i < 20.9. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Natl Astron Observ Japan, Tokyo 1818588, Japan. NASA, Washington, DC 20546 USA. Natl Astron Observ Japan, Okayama Astrophys Observ, Kamogata, Okayama 7190232, Japan. Apache Point Observ, Sunspot, NM 88349 USA. RP Chiu, K (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. EM chiu@pha.jhu.edu RI Glazebrook, Karl/N-3488-2015 OI Glazebrook, Karl/0000-0002-3254-9044 NR 38 TC 12 Z9 12 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUL PY 2005 VL 130 IS 1 BP 13 EP 22 DI 10.1086/430525 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PW UT WOS:000230085900002 ER PT J AU Wallace, DJ Gies, DR Moffat, AFJ Shara, MM Niemela, VS AF Wallace, DJ Gies, DR Moffat, AFJ Shara, MM Niemela, VS TI Hubble Space Telescope imaging of the WR 38/WR 38A cluster SO ASTRONOMICAL JOURNAL LA English DT Article DE binaries : visual; open clusters and associations : individual (C1104-610a); stars : imaging; stars : individual (WR 38, WR 38a); stars : Wolf-Rayet ID WOLF-RAYET STARS; CHARGE-TRANSFER EFFICIENCY; MODEL ATMOSPHERES; MOLECULAR CLOUDS; INTRINSIC COLORS; SPIRAL STRUCTURE; OB SUPERGIANTS; MILKY-WAY; WFPC2; CALIBRATION AB We are conducting a high angular resolution imaging survey of Galactic Wolf-Rayet stars using the Wide Field Planetary Camera 2 aboard the Hubble Space Telescope (HST). We have found a small stellar cluster associated with the faint, close pair WR 38 and WR 38a. We present astrometric measurements and photometry in the wide-band F336W ( U), F439W ( B), and F555W ( V) filter system for the cluster and nearby stars. We combine our photometry with Johnson and IR magnitudes and compare the observations with calibrated model results for reddened stars to adjust the HST zero points and to identify five probable main-sequence members of the cluster. A least-squares fit of the colors and magnitudes of this set yields a cluster reddening of E( B - V) = 1.63 +/- 0.05 mag and a distance of 10(-4)(+12) kpc for an assumed ratio of total to selective extinction of R = 3.1. We discuss the relationship of this cluster to other objects along the line of sight. If situated at a distance of approximate to 8 kpc, then the cluster would reside in a dense region of the Carina spiral arm, close to a giant molecular cloud and the starburst cluster NGC 3603. C1 Georgia State Univ, Dept Phys & Astron, Ctr High Angular Resolut Astron, Atlanta, GA 30302 USA. Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. Univ Montreal, Observ Mt Megant, Montreal, PQ H3C 3J7, Canada. Amer Museum Nat Hist, Dept Astrophys, New York, NY 10024 USA. Natl Univ La Plata, Fac Ciencias Astron & Geofis, RA-1900 La Plata, Argentina. RP Wallace, DJ (reprint author), NASA, Goddard Space Flight Ctr, Code 685,Bldg 21, Greenbelt, MD 20771 USA. EM wallace@chara.gsu.edu; gies@chara.gsu.edu; moffat@astro.umontreal.ca; mshara@amnh.org; virpi@lilen.fcaglp.unlp.edu.ar NR 50 TC 3 Z9 3 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 JUL PY 2005 VL 130 IS 1 BP 126 EP 133 DI 10.1086/430671 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PW UT WOS:000230085900011 ER PT J AU Kraus, S Schloerb, FP Traub, WA Carleton, NP Lacasse, M Pearlman, M Monnier, JD Millan-Gabet, R Berger, JP Haguenauer, P Perraut, K Kern, P Malbet, F Labeye, P AF Kraus, S Schloerb, FP Traub, WA Carleton, NP Lacasse, M Pearlman, M Monnier, JD Millan-Gabet, R Berger, JP Haguenauer, P Perraut, K Kern, P Malbet, F Labeye, P TI Infrared imaging of Capella with the IOTA closure phase interferometer SO ASTRONOMICAL JOURNAL LA English DT Article DE binaries : close; binaries : spectroscopic; methods : data analysis; stars : individual (Capella); techniques : interferometric ID SPECTROSCOPIC BINARIES; BEAM-COMBINATION; STARS AB We present infrared aperture synthesis maps produced with the upgraded Infrared Optical Telescope Array interferometer. Michelson interferograms on the close binary system Capella (alpha Aur) were obtained in the H band between 2002 November 12 and 16 using the IONIC3 beam combiner. With baselines of 15 m <= B <= 38 m, we were able to determine the relative position of the binary components with milliarcsecond precision and to track their movement along the approximate to 14 degrees arc covered by our observation run. We briefly describe the algorithms used for visibility and closure phase estimation. Three different hybrid mapping and bispectrum fitting techniques were implemented within one software framework and used to reconstruct the source brightness distribution. By dividing our data into subsets, the system could be mapped at three epochs, revealing the motion of the stars. The precise position of the binary components was also determined with model fits, which in addition revealed I-Aa/I-Ab = 1.49 +/- 0.10 and apparent stellar uniform-disk diameters of Theta(Aa) = 8.9 +/- 0.6 mas and Theta(Ab) = 5.8 +/- 0.8 mas. To improve the (u, v)-plane coverage, we compensated this orbital motion by applying a rotation-compensating coordinate transformation. The resulting model-independent map with a beam size of 5: 4 mas; 2: 6 mas allows the resolution of the stellar surfaces of the Capella giants themselves. C1 Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Max Planck Inst Radioastron, D-53121 Bonn, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48104 USA. CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. Lab Astrophys Grenoble, F-38041 Grenoble, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CEA, LETI, Dept Microtechnol, F-38054 Grenoble, France. RP Kraus, S (reprint author), Univ Massachusetts, Dept Astron, LGRT-B 619E,710 N Pleasant St, Amherst, MA 01003 USA. EM skraus@mpifr-bonn.mpg.de NR 24 TC 26 Z9 26 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 JUL PY 2005 VL 130 IS 1 BP 246 EP 255 DI 10.1086/430456 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PW UT WOS:000230085900022 ER PT J AU Grosso, N Kastner, JH Ozawa, H Richmond, M Simon, T Weintraub, DA Hamaguchi, K Frank, A AF Grosso, N Kastner, JH Ozawa, H Richmond, M Simon, T Weintraub, DA Hamaguchi, K Frank, A TI Enhanced X-ray variability from V1647 Ori, the young star in outburst illuminating McNeil's Nebula SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : individual : V1647 Ori; stars : pre-main sequence; X-rays : stars ID STELLAR OBJECTS; T-TAURI; ACCRETION; JETS; DUST; IRAS-05436-0007; SPECTROSCOPY; MECHANISM; CHANDRA; REGION AB We report a similar to 38 ks X-ray observation of McNeil's Nebula obtained with XMM-Newton on 2004 April 4. V1647 Ori, the young star in outburst illuminating McNeil's Nebula, is detected with XMM-Newton and appears variable in X-rays. We investigate the hardness ratio variability and time variations of the event energy distribution with quantile analysis, and show that the large increase of the count rate from V1647 Ori observed during the second half of the observation is not associated with any large plasma temperature variations as for typical X-ray flares from young low-mass stars. X-ray spectral fitting shows that the bulk (similar to 75%) of the intrinsic X-ray emission in the 0.5-8 keV energy band comes from a soft plasma component, with kT(soft) = 0.9 keV (0.7-1.1 keV, at the 90% confidence limit), reminiscent of the X-ray spectrum of the classical T Tauri star TW Hya, for which X-ray emission is believed to be generated by an accretion shock onto the photosphere of a low-mass star. The hard plasma component, with kT(hard) = 4.2 keV (3.0-6.5 keV), contributes similar to 25% of the total X-ray emission, and can be understood only in the framework of plasma heating sustained by magnetic reconnection events. We find a hydrogen column density of N-H = 4.1 x 10(22) cm(-2) (3.5-4.7 x 10(22) cm(-2)), which points out a significant excess of hydrogen column density compared to the value derived from optical/IR observations, consistent with the picture of the rise of a wind/jet unveiled from ground optical spectroscopy. The X-ray flux observed with XMM-Newton ranges from roughly the flux observed by Chandra on 2004 March 22 ( i.e. similar to 10 times greater than the pre-outburst X-ray flux) to a value two times greater than that caught by Chandra on 2004 March 7 ( i.e. similar to 200 times greater than the pre-outburst X-ray flux). The X- ray variability of V1647 Ori in outburst is clearly enhanced. We have investigated the possibility that V1647 Ori displays a periodic variation in X- ray brightness as suggested by the combined Chandra+XMM-Newton data set. Assuming that the X- ray flux density is periodic, the folding of the two Chandra observed X- ray flux densities with the XMM-Newton ones leads to three periodic X- ray light curve solutions. Our best period candidate is 0.72 day, which corresponds to the time scale of the Keplerian rotation at a distance of 1 and 1.4 stellar radius for a one solar mass star aged of 0.5 and 1 Myrs, respectively. We propose that the emission measure, i.e. the observed X- ray flux, is modulated by the Keplerian rotation of the inner part of the V1647 Ori accretion disk. C1 Univ Grenoble 1, Lab Astrophys Grenoble, F-38041 Grenoble, France. Rochester Inst Technol, Rochester, NY 14623 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Vanderbilt Univ, Nashville, TN 37235 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Washington, DC 20001 USA. CNR, Washington, DC 20001 USA. Univ Rochester, Rochester, NY 14627 USA. RP Grosso, N (reprint author), Univ Grenoble 1, Lab Astrophys Grenoble, F-38041 Grenoble, France. EM Nicolas.Grosso@obs.ujf-grenoble.fr NR 53 TC 27 Z9 27 U1 0 U2 0 PU EDP SCIENCES 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 JUL PY 2005 VL 438 IS 1 BP 159 EP 168 DI 10.1051/0004-6361:20042182 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 943XC UT WOS:000230387800017 ER PT J AU Barthelemy, M Lilensten, J Parkinson, C AF Barthelemy, M Lilensten, J Parkinson, C TI H-2 vibrational temperatures in the upper atmosphere of Jupiter SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ultraviolet : solar system; radiative transfer; planets and satellites : individual : Jupiter ID EXTREME ULTRAVIOLET OBSERVATIONS; DAYGLOW; TELESCOPE; ENCOUNTER; EMISSION; HYDROGEN AB The Jovian upper atmosphere has been extensively studied over the past few decades with many observations having been made. Typically, the H-2 vibrational temperatures have always been considered as kinetic temperatures in modelling efforts to date. However, recent studies have shown that this assumption is not robust and that we can expect enhanced vibrational temperatures due to overlapping lines to play an important role in the thermosphere of Jupiter. In this paper, we use a radiative transfer code to compute the total integrated H Lyman alpha dayglow intensity taking into account the overlapping with H-2 hot bands. We show that an atmosphere with H-2 vibrational temperatures equal to about 1.4 to 1.5 times kinetic reproduce the Voyager observations. C1 UJF, CNRS, Lab Planetol Grenoble, F-38041 Grenoble, France. CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Barthelemy, M (reprint author), UJF, CNRS, Lab Planetol Grenoble, BP 53, F-38041 Grenoble, France. EM mathieu.barthelemy@ujf-grenoble.fr; cdp@gps.caltech.edu NR 17 TC 5 Z9 5 U1 0 U2 0 PU E D P SCIENCES 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 JUL PY 2005 VL 437 IS 1 BP 329 EP 331 DI 10.1051/0004-6361:20040257 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 934XF UT WOS:000229742200038 ER PT J AU Malbet, F Lachaume, R Berger, JP Colavita, MM Di Folco, E Eisner, JA Lane, BF Millan-Gabet, R Segransan, D Traub, WA AF Malbet, F Lachaume, R Berger, JP Colavita, MM Di Folco, E Eisner, JA Lane, BF Millan-Gabet, R Segransan, D Traub, WA TI New insights on the AU-scale circumstellar structure of FU Orionis SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : pre-main-sequence; stars : individual : FU Ori; planetary systems : protoplanetary disks; infrared : stars; accretion, accretion disks; techniques : interferometric ID HERBIG AE/BE STARS; T-TAURI STARS; INFRARED INTERFEROMETRIC OBSERVATIONS; PALOMAR TESTBED INTERFEROMETER; COMMISSIONING INSTRUMENT; OPTICAL INTERFEROMETRY; STELLAR EVOLUTION; DISKS; OUTBURSTS; OBJECTS AB We report new near-infrared, long-baseline interferometric observations at the AU scale of the pre-main-sequence star FU Orionis with the PTI, IOTA and VLTI interferometers. This young stellar object has been observed on 42 nights over a period of 6 years from 1998 to 2003. We have obtained 287 independent measurements of the fringe visibility with 6 different baselines ranging from 20 to 110 m in length, in the H and K bands. Our data resolves FU Ori at the AU scale, and provides new constraints at shorter baselines and shorter wavelengths. Our extensive (u, v)- plane coverage, coupled with the published spectral energy distribution data, allows us to test the accretion disk scenario. We find that the most probable explanation for these observations is that FU Ori hosts an active accretion disk whose temperature law is consistent with standard models and with an accretion rate of. M = (6.3 +/- 0.6) x 10(-5) (M-* M-circle dot)(-1) M-circle dot yr(-1). We are able to constrain the geometry of the disk, including an inclination of 55(-7)(+5) deg and a position angle of 47(-11)(+7) deg. In addition, a 10 percent peak-to-peak oscillation is detected in the data ( at the two-sigma level) from the longest baselines, which we interpret as a possible disk hot-spot or companion. The still somewhat limited ( u, v) sampling and substantial measurement uncertainty prevent us from constraining the location of the spot with confidence, since many solutions yield a statistically acceptable fit. However, the oscillation in our best data set is best explained with an unresolved spot located at a projected distance of 10 +/- 1 AU at the 130 +/- 1 deg position angle and with a magnitude difference of Delta K approximate to 3.9 +/- 0.2 and Delta H approximate to 3.6 +/- 0.2 mag moving away from the center at a rate of 1.2 +/- 0.6 AU yr(-1). Although this bright spot on the surface of the disk could be tracing some thermal instabilities in the disk, we propose to interpret this spot as the signature of a companion of the central FU Ori system on an extremely eccentric orbit. We speculate that the close encounter of this putative companion and the central star could be the explanation of the initial photometric rise of the luminosity of this object. C1 UJF, Lab Astrophys Grenoble, CNRS, UMR 5571, F-38041 Grenoble, France. Max Planck Inst Radioastron, D-53121 Bonn, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. European So Observ, D-85748 Garching, Germany. CALTECH, Dept Astron, Pasadena, CA 91125 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. Observ Geneva, CH-1290 Sauverny, Switzerland. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Malbet, F (reprint author), UJF, Lab Astrophys Grenoble, CNRS, UMR 5571, BP 53, F-38041 Grenoble, France. EM Malbet@obs.ujf-grenoble.fr NR 51 TC 52 Z9 52 U1 0 U2 1 PU E D P SCIENCES 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 JUL PY 2005 VL 437 IS 2 BP 627 EP 636 DI 10.1051/0004-6361:20042556 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 938CV UT WOS:000229978400025 ER PT J AU de Martino, D Matt, G Mukai, K Bonnet-Bidaud, JM Gansicke, BT Perez, JMG Haberl, F Mouchet, M Solheim, JE AF de Martino, D Matt, G Mukai, K Bonnet-Bidaud, JM Gansicke, BT Perez, JMG Haberl, F Mouchet, M Solheim, JE TI X-ray confirmation of the intermediate polar HT Cam SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : binaries : close; stars : individual : HT Cam; stars : novae, cataclysmic variables ID MAGNETIC CATACLYSMIC VARIABLES; HUBBLE-SPACE-TELESCOPE; HELIUM-LIKE IONS; EX-HYDRAE; WHITE-DWARF; BEPPOSAX OBSERVATIONS; XMM-NEWTON; PULSATIONS; ACCRETION; PLASMA AB We report on the first pointed X-ray observations with XMM-Newton and RXTE satellites of the X-ray source RXJ0757.0+6306 = HT Cam. We detect a strong 515 s X-ray modulation confirming the optical photometric period found in 1998, which definitively assigns this source to the intermediate polar class of magnetic cataclysmic variables. The lack of orbital sidebands in the X-rays indicates that the X-ray period is the spin period of the accreting white dwarf. Simultaneous ultraviolet and optical B-band photometry acquired with the XMM-Newton Optical Monitor and coordinated optical UBVRI photometric data acquired at the Nordic Optical Telescope ( La Palma) show that the optical pulse is in phase with the X-rays and hence originates in the magnetically-confined accretion flow. The lack of ultraviolet spin modulation suggests that accretion-induced heating on the white dwarf surface is not important in this source. Spectral analyses of XMM-Newton EPIC and RGS data show that HTCam has a multi-temperature spectrum and, contrary to most intermediate polars, it does not suffer from strong absorption. With its 86 min orbital period, HTCam is the third confirmed system of this class below the 2-3 h period gap accreting at a low rate. C1 INAF, Osservatorio Astron Capodimonte, I-80131 Naples, Italy. Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. NASA, Goddard Space Flight Ctr, Lab High Energy Astrophys, Greenbelt, MD 20771 USA. CE Saclay, Serv Astrophys, DSM, DAPNIA,SAp, F-91191 Gif Sur Yvette, France. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Inst Astrofis Canarias, La Laguna, Spain. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. Univ Denis Diderot, APC, UMR 7164, F-75004 Paris, France. Observ Paris, LUTH, F-92195 Meudon, France. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. RP de Martino, D (reprint author), INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy. EM demartino@na.astro.it; matt@fis.uniroma3.it; mukai@milkyway.gsfc.nasa.gov; bonnetbidaud@cea.fr; boris.gaensicke@warwick.ac.uk; jgperez@iac.es; fwh@mpe.mpg.de; martine.mouchet@obspm.fr; janerik@phys.uit.no RI Gaensicke, Boris/A-9421-2012; OI Gaensicke, Boris/0000-0002-2761-3005; Haberl, Frank/0000-0002-0107-5237; de Martino, Domitilla/0000-0002-5069-4202 NR 44 TC 16 Z9 16 U1 0 U2 0 PU E D P SCIENCES 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 JUL PY 2005 VL 437 IS 3 BP 935 EP 945 DI 10.1051/0004-6361:20052761 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 941JC UT WOS:000230210100019 ER PT J AU Yaqoob, T Reeves, JN Markowitz, A Serlemitsos, PJ Padmanabhan, U AF Yaqoob, T Reeves, JN Markowitz, A Serlemitsos, PJ Padmanabhan, U TI Chandra high-resolution X-ray spectroscopy of the FeK line in the Seyfert 1 galaxy NGC 3783 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; galaxies : active; galaxies : individual (NGC 3783); galaxies : Seyfert; line : profiles; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; K-ALPHA LINE; TRANSMISSION GRATING SPECTROMETER; BLACK-HOLE SYSTEMS; IONIZED-GAS; COMPTON REFLECTION; TIMING-EXPLORER; IRON LINES; VARIABILITY; ENVIRONMENT AB We report on the results of detailed X-ray spectroscopy of the Fe K region in the Seyfert 1 galaxy NGC 3783 using the Chandra High Energy Grating Transmission Spectrometer (HETGS). There were five observations over an interval of similar to 125 days in 2001, each with an exposure time of similar to 170 ks. The combined data constitute the highest signal-to-noise Fe K spectrum having the best velocity resolution in the Fe K band to date (FWHM similar to 1860 km s(-1)). The combined data show a resolved Fe K alpha line core ( FWHM = 1700(-390)(+410) km s(-1)) with a center energy of 6.397 +/- 0.003 keV, consistent with an origin in neutral or lowly ionized Fe, located between the BLR and NLR, as found by Kaspi et al. in 2002. We also find that excess flux around the base of the Fe K alpha line core can be modeled with either a Compton-scattering "shoulder'' or an emission line ( with about the same flux as the line core) from a relativistic accretion disk, having an inclination angle of 11 degrees or less. This disk-line model is as good as a Compton-shoulder model for the base of the Fe K alpha line core. In the latter model, we measured the column density to be 7.5(-0.6)(+2.7) x 10(23) cm(-2), which corresponds to a Thomson optical depth of similar to 0.60, so the line-emitting matter is not quite Compton-thick. An intrinsic width of 1500(-340)(+460) km s(-1) FWHM is still required in this model. Moreover, more complicated scenarios involving both a Compton shoulder and a disk line cannot be ruled out. We confirm an absorption feature due to He-like Fe (FWHM = 6405(-2670)(+5020) km s(-1)) found in previous studies. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Yaqoob, T (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NR 40 TC 21 Z9 21 U1 0 U2 1 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 JUL 1 PY 2005 VL 627 IS 1 BP 156 EP 165 DI 10.1086/430404 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PZ UT WOS:000230086200012 ER PT J AU Ramirez, JM Bautista, M Kallman, T AF Ramirez, JM Bautista, M Kallman, T TI Line asymmetry in the Seyfert galaxy NGC 3783 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 3783); galaxies : Seyfert; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; IONIZED-GAS; ENVIRONMENT; ABSORPTION; SPECTRA; WINDS; SPECTROSCOPY; VARIABILITY; ABSORBER; PROFILES AB We have reanalyzed the 900 ks Chandra X-ray spectrum of NGC 3783, finding evidence on the asymmetry of the spectral absorption lines. The lines are fitted with a parametric expression that results from an analytical treatment of radiatively driven winds. The line asymmetry distribution derived from the spectrum is consistent with a nonspherical outflow with a finite optical depth. Within this scenario, our model explains the observed correlations between the line velocity shifts and the ionization parameter and between the line velocity shift and the line asymmetry. The present results may provide a framework for detailed testing of models for the dynamics and physical properties of warm absorbers in Seyfert galaxies. C1 Inst Venezolano Invest Cient, Phys Ctr, Caracas 1020A, Venezuela. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ramirez, JM (reprint author), Inst Venezolano Invest Cient, Phys Ctr, POB 21827, Caracas 1020A, Venezuela. NR 30 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 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2005 VL 627 IS 1 BP 166 EP 176 DI 10.1086/430202 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PZ UT WOS:000230086200013 ER PT J AU Band, DL Preece, RD AF Band, DL Preece, RD TI Testing the gamma-ray burst energy relationships SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts ID STAR-FORMATION HISTORY; PEAK ENERGY; BATSE; DISTRIBUTIONS; ENERGETICS; SPECTRA; LUMINOSITY; REDSHIFTS; UNIVERSE; CATALOG AB Building on Nakar & Piran's analysis of the Amati relation relating gamma-ray burst peak energies, E-p, and isotropic energies, E-iso, we test the consistency of a large sample of BATSE bursts with the Amati and Ghirlanda (which relate peak energies and actual gamma-ray energies, E gamma) relations. Each of these relations can be expressed as a ratio of the different energies that is a function of redshift ( for both the Amati and Ghirlanda relations) and beaming fraction f(B) ( for the Ghirlanda relation). The most rigorous test, which allows bursts to be at any redshift, corroborates Nakar & Piran's result -88% of the BATSE bursts are inconsistent with the Amati relation - while only 1.6% of the bursts are inconsistent with the Ghirlanda relation if f(B) = 1. Even when we allow for a real dispersion in the Amati relation, we find an inconsistency. Modeling the redshift distribution results in an energy ratio distribution for the Amati relation that is shifted by an order of magnitude relative to the observed distribution; any subpopulation satisfying the Amati relation can comprise at most similar to 18% of our burst sample. A similar analysis of the Ghirlanda relation depends sensitively on the beaming fraction distribution for small values of f(B); for reasonable estimates of this distribution about a third of the burst sample is inconsistent with the Ghirlanda relation. Our results indicate that these relations are an artifact of the selection effects of the burst sample in which they were found; these selection effects may favor subpopulations for which these relations are valid. C1 NASA, Goddard Space Flight Ctr, GLAST SSC, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP Band, DL (reprint author), NASA, Goddard Space Flight Ctr, GLAST SSC, Code 661, Greenbelt, MD 20771 USA. EM dband@milkyway.gsfc.nasa.gov; rob.preece@msfc.nasa.gov OI Preece, Robert/0000-0003-1626-7335 NR 22 TC 111 Z9 111 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 JUL 1 PY 2005 VL 627 IS 1 BP 319 EP 323 DI 10.1086/430402 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PZ UT WOS:000230086200025 ER PT J AU Norris, JP Bonnell, JT Kazanas, D Scargle, JD Hakkila, J Giblin, TW AF Norris, JP Bonnell, JT Kazanas, D Scargle, JD Hakkila, J Giblin, TW TI Long-lag, wide-pulse gamma-ray bursts SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; ISM : jets and outflows ID 25 APRIL 1998; BATSE OBSERVATIONS; UNUSUAL SUPERNOVA; SPECTRAL LAGS; LUMINOSITY; ENERGY; GRB-031203; EMISSION; GRB-980425; DURATIONS AB Currently, the best available probe of the early phase of gamma-ray burst (GRB) jet attributes is the prompt gamma-ray emission, in which several intrinsic and extrinsic variables determine GRB pulse evolution. Bright, usually complex bursts have many narrow pulses that are difficult to model due to overlap. However, the relatively simple, long spectral lag, wide-pulse bursts may have simpler physics and are easier to model. In this work we analyze the temporal and spectral behavior of wide pulses in 24 long-lag bursts, using a pulse model with two shape parameters - width and asymmetry - and the Band spectral model with three shape parameters. We find that pulses in long-lag bursts are distinguished both temporally and spectrally from those in bright bursts: the pulses in long spectral lag bursts are few in number and similar to 100 times wider ( tens of seconds), have systematically lower peaks in upsilon F(upsilon), and have harder low-energy spectra and softer high-energy spectra. We find that these five pulse descriptors are essentially uncorrelated for our long-lag sample, suggesting that at least similar to 5 parameters are needed to model burst temporal and spectral behavior. However, pulse width is strongly correlated with spectral lag; hence, these two parameters may be viewed as mutual surrogates. We infer that accurate formulations for estimating GRB luminosity and total energy will depend on several gamma-ray attributes, at least for long-lag bursts. The prevalence of long-lag bursts near the BATSE trigger threshold, their predominantly low upsilon F(upsilon) spectral peaks, and relatively steep upper power-law spectral indices indicate that Swift will detect many such bursts. C1 NASA, Goddard Space Flight Ctr, Lab High Energy Astrophys, Greenbelt, MD 20771 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Coll Charleston, Dept Phys & Astron, Sci Ctr 101, Charleston, SC 29424 USA. RP Norris, JP (reprint author), NASA, Goddard Space Flight Ctr, Lab High Energy Astrophys, Greenbelt, MD 20771 USA. NR 47 TC 109 Z9 109 U1 0 U2 2 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 JUL 1 PY 2005 VL 627 IS 1 BP 324 EP 345 DI 10.1086/430294 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PZ UT WOS:000230086200026 ER PT J AU Bhardwaj, A Elsner, RF Waite, JH Gladstone, GR Cravens, TE Ford, PG AF Bhardwaj, A Elsner, RF Waite, JH Gladstone, GR Cravens, TE Ford, PG TI The discovery of oxygen K alpha X-ray emission from the rings of Saturn SO ASTROPHYSICAL JOURNAL LA English DT Article DE planets and satellites : individual (Saturn); planets : rings; scattering; Sun : X-rays, gamma rays; Xrays : general; X rays : individual (Saturn's rings) ID CHANDRA; PLASMA; MAGNETOSPHERE; DYNAMICS; SPOKES; COMETS AB Using the Advanced CCD Imaging Spectrometer (ACIS), the Chandra X-Ray Observatory observed the Saturnian system for one rotation of the planet (similar to 37 ks) on 2004 January 20 and again on January 26-27. In this Letter we report the detection of X-ray emission from the rings of Saturn. The X-ray spectrum from the rings is dominated by emission in a narrow (similar to 130 eV-wide) energy band centered on the atomic oxygen K alpha fluorescence line at 0.53 keV. The X-ray power emitted from the rings in the 0.49-0.62 keV band is 84 MW, which is about one-third of that emitted from Saturn's disk in the photon energy range 0.24-2.0 keV. Our analysis also finds a clear detection of X-ray emission from the rings in the 0.49-0.62 keV band in an earlier 2003 April 14-15) Chandra ACIS observation of Saturn. Fluorescent scattering of solar X-rays from oxygen atoms in the H2O icy ring material is the likely source mechanism for ring X-rays, consistent with the scenario of the solar photo-production of a tenuous oxygen atmosphere and ionosphere over the rings recently discovered by Cassini. C1 NASA, George C Marshall Space Flight Ctr, NSSTC XD 12, Huntsville, AL 35805 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. SW Res Inst, San Antonio, TX 78228 USA. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. RP Bhardwaj, A (reprint author), NASA, George C Marshall Space Flight Ctr, NSSTC XD 12, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM anil.bhardwaj@msfc.nasa.gov; ron.elsner@msfc.nasa.gov; hunterw@umich.edu; randy.gladstone@swri.org; cravens@ku.edu; pgf@space.mit.edu OI Bhardwaj, Anil/0000-0003-1693-453X NR 25 TC 14 Z9 14 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 JUL 1 PY 2005 VL 627 IS 1 BP L73 EP L76 DI 10.1086/431933 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939QC UT WOS:000230086500019 ER PT J AU Fortney, JJ Marley, MS Lodders, K Saumon, D Freedman, R AF Fortney, JJ Marley, MS Lodders, K Saumon, D Freedman, R TI Comparative planetary atmospheres: Models of TrES-1 and HD 209458B SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : eclipsing; planetary systems; radiative transfer; stars : individual (TrES-1, HD 209458) ID EXTRASOLAR GIANT PLANETS; HD 209458B; TRANSITING PLANET; THERMAL STRUCTURE; BROWN DWARFS; GLIESE 229B; CHEMISTRY; STAR; PREDICTIONS; ABUNDANCES AB We present new self-consistent atmosphere models for the transiting planets TrES-1 and HD 209458b. The planets were recently observed with the Spitzer Space Telescope in bands centered on 4.5 and 8.0 mu m, for TrES-1, and 24 mu m, for HD 209458b. We find that standard solar-metallicity models fit the observations for HD 209458b. For TrES-1, which has a T-eff similar to 300 K cooler, we find that models with a metallicity 3-5 times enhanced over solar abundances can match the 1 sigma error bar at 4.5 mu m and 2 sigma at 8.0 mu m. Models with solar abundances that include energy deposition into the stratosphere give fluxes that fall within the 2 sigma error bars in both bands. The best-fit models for both planets assume that reradiation of absorbed stellar flux occurs over the entire planet. For all models of both planets, we predict planet-to-star flux ratios in other Spitzer bandpasses. C1 NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Moffett Field, CA 94035 USA. Washington Univ, Planetary Chem Lab, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. SETI Inst, Mountain View, CA 94043 USA. RP Fortney, JJ (reprint author), NASA, Ames Res Ctr, Space Sci & Astrobiol Div, MS 245-3, Moffett Field, CA 94035 USA. EM jfortney@arc.nasa.gov RI Marley, Mark/I-4704-2013; OI Fortney, Jonathan/0000-0002-9843-4354 NR 46 TC 132 Z9 133 U1 0 U2 1 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 JUL 1 PY 2005 VL 627 IS 1 BP L69 EP L72 DI 10.1086/431952 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939QC UT WOS:000230086500018 ER PT J AU Barkats, D Bischoff, C Farese, P Gaier, T Gundersen, JO Hedman, MM Hyatt, L McMahon, JJ Samtleben, D Staggs, ST Stefanescu, E Vanderlinde, K Winstein, B AF Barkats, D Bischoff, C Farese, P Gaier, T Gundersen, JO Hedman, MM Hyatt, L McMahon, JJ Samtleben, D Staggs, ST Stefanescu, E Vanderlinde, K Winstein, B TI Cosmic microwave background polarimetry using correlation receivers with the PIQUE and CAPMAP experiments SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE cosmic microwave background; cosmology : observations; instrumentation : polarimeters ID PROBE WMAP OBSERVATIONS; ANGULAR SCALE INTERFEROMETER; CMB POLARIZATION; FEED HORNS; ANISOTROPY; RADIATION; DESIGN; BEAM; RADIOMETERS; INSTRUMENT AB The Princeton IQU Experiment ( PIQUE) and the Cosmic Anisotropy Polarization Mapper ( CAPMAP) are experiments designed to measure the polarization of the cosmic microwave background ( CMB) on sub- degree scales in an area within 1 degrees of the North Celestial Pole using heterodyne correlation polarimeters and off- axis telescopes located in central New Jersey. PIQUE produced the tightest limit on the CMB polarization prior to its detection by DASI, while CAPMAP has recently detected polarization at l similar to 1000. The experimental methods and instrumentation for these two projects are described in detail with emphasis on the particular challenges involved in measuring the tiny polarized component of the CMB. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Miami, Dept Phys, Coral Gables, FL 33146 USA. RP CALTECH, Dept Phys, Pasadena, CA 91125 USA. OI Barkats, Denis/0000-0002-8971-1954; Bischoff, Colin/0000-0001-9185-6514 NR 56 TC 21 Z9 21 U1 0 U2 3 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 JUL PY 2005 VL 159 IS 1 BP 1 EP 26 DI 10.1086/430208 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PH UT WOS:000230084400001 ER PT J AU Taylor, GB Fassnacht, CD Sjouwerman, LO Myers, ST Ulvestad, JS Walker, RC Fomalont, EB Pearson, TJ Readhead, ACS Gehrels, N Michelson, PF AF Taylor, GB Fassnacht, CD Sjouwerman, LO Myers, ST Ulvestad, JS Walker, RC Fomalont, EB Pearson, TJ Readhead, ACS Gehrels, N Michelson, PF TI VLBA imaging polarimetry of active galactic nuclei: An automated approach SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE catalogs; galaxies : active; galaxies : jets; galaxies : nuclei; radio continuum : galaxies; surveys; techniques : polarimetric ID COMPACT SYMMETRIC OBJECTS; DIGITAL-SKY-SURVEY; SCALE ROTATION MEASURES; SPECTRUM RADIO-SOURCES; GAMMA-RAY BLAZARS; COMPLETE SAMPLE; EGRET SOURCES; FARADAYS FOG; IDENTIFICATIONS; RELEASE AB We present full polarization Very Long Baseline Array ( VLBA) observations at 5 and 15 GHz of 24 compact active galactic nuclei ( AGNs). These sources were observed as part of a pilot project to demonstrate the feasibility of conducting a large VLBI survey to further our understanding of the physical properties and temporal evolution of AGN jets. The sample is drawn from the Cosmic Lens All- Sky Survey ( CLASS) where it overlaps with the Sloan Digital Sky Survey at declinations north of 15 degrees. There are 2100 CLASS sources brighter than 50 mJy at 8.4 GHz, of which we have chosen 24 for this pilot study. All 24 sources were detected and imaged at 5 GHz with a typical dynamic range of 500: 1, and 21 of 24 sources were detected and imaged at 15 GHz. Linear polarization was detected in eight sources at both 5 and 15 GHz, allowing for the creation of Faraday rotation measure ( RM) images. The core RMs for the sample were found to have an average absolute value of 390 +/- 100 rad m(-2). We also present the discovery of a new compact symmetric object, J08553+ 5751. All data were processed automatically using pipelines created or adapted for the survey. C1 Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. CALTECH, Owens Valley Radio Observ, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RP Taylor, GB (reprint author), Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA. RI Gehrels, Neil/D-2971-2012; Pearson, Timothy/N-2376-2015; OI Pearson, Timothy/0000-0001-5213-6231; Ulvestad, James/0000-0002-9362-7237 NR 31 TC 23 Z9 23 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUL PY 2005 VL 159 IS 1 BP 27 EP 40 DI 10.1086/430255 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PH UT WOS:000230084400002 ER PT J AU Winnewisser, M Medvedev, IR De Lucia, FC Herbst, E Koput, J Sastry, KVLN Butler, RAH AF Winnewisser, M Medvedev, IR De Lucia, FC Herbst, E Koput, J Sastry, KVLN Butler, RAH TI The millimeter- and submillimeter-wave spectrum of cyanoformamide SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE astrochemistry; ISM : molecules; molecular data ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; INTERSTELLAR FORMAMIDE; MICROWAVE DETECTION; ANALYTICAL TOOL; GAS-PHASE; ASSIGNMENT; HYDROGEN; SYSTEMS; CYANIDE AB The organic species cyanoformamide ( NCCONH(2)) is the cyano ( CN) derivative of formamide ( NH(2)CHO), a known interstellar molecule with a role in the synthesis of nucleic acid precursors under prebiotic conditions. Until quite recently, the rotational spectrum of cyanoformamide had not been studied. Based partially on the results of a newly published microwave study and on the results of our ab initio calculations, we have measured and assigned 2691 transitions of the millimeter- and submillimeter- wave spectrum of this molecule through 360 GHz with the fastscan submillimeter spectroscopic technique ( FASSST). These transitions have been added to the previously measured 135 microwave transitions to produce a global data set of 2826 transitions that was analyzed to within experimental accuracy with a standard asymmetric- top fitting procedure. With the determined spectroscopic constants and dipole moment components, we are able to predict the frequencies and intensities of many additional lines through 400 GHz. Cyanoformamide can now be searched for over a wide frequency range in likely interstellar sources such as hot molecular cores. C1 Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Adam Mickiewicz Univ Poznan, Dept Chem, PL-60780 Poznan, Poland. Univ New Brunswick, Dept Phys, Fredericton, NB E3B 5A3, Canada. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. RP Winnewisser, M (reprint author), Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA. RI Medvedev, Ivan/E-8486-2014 NR 38 TC 4 Z9 4 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUL PY 2005 VL 159 IS 1 BP 189 EP 195 DI 10.1086/430470 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PH UT WOS:000230084400010 ER PT J AU Deierling, W Latham, J Petersen, WA Ellis, SM Christian, HJ AF Deierling, W Latham, J Petersen, WA Ellis, SM Christian, HJ TI On the relationship of thunderstorm ice hydrometeor characteristics and total lightning measurements SO ATMOSPHERIC RESEARCH LA English DT Article; Proceedings Paper CT 12th International Conference on Atmospheric Electricity (ICAE) CY JUN 09-12, 2003 CL Versailles, FRANCE DE lightning; polarimetric radar; precipitation; ice ID THUNDERCLOUD PARAMETERS; CONVECTIVE RAINFALL; PRECIPITATION RATES; STERAO-A; JULY 10; RADAR; STORM; ELECTRIFICATION; SATELLITE; RADIATION AB Satellite-borne and ground-based devices for the detection of lightning offer the opportunity to explore relationships-on all significant scales up to global-between lightning frequency,f, and other thundercloud parameters. Calculations predict that f is proportional to the product of the downflux p of solid precipitation and the upward mass flux, I, of ice crystals. This prediction has received support from limited computational studies. The physical reasons for such a relationship are explained in terms of the paramount role of ice in the electrification of thunderstorms. Herein, this prediction is subjected to further, preliminary examination through analysis of lightning and dual-polarimetric radar data collected during the STERAO experiment conducted in Northern Colorado during the summer of 1996. The analysis has yielded sonic highly provisional support for this flux hypothesis. Computed trends of radar derived hydrometeor fractions of solid precipitation and small ice show correlation to the total lightning frequency and raise the possibility of determining values of p and/or I from lightning measurements. It is shown that the extent to which the observed correlations between f and both solid precipitation and small ice trends are or are not strong can provide an indication as to whether the lightning activity is limited by the available concentrations of precipitating or non-precipitating ice in the upper regions of the charging zone of the thundercloud, where most of the charge transfer occurs. It is demonstrated that the most accurate determinations of precipitation rate p from measurements of lighting frequency f are likely to be for conditions where the field-growth is limited by the availability of graupel pellets. It is shown that the simultaneous time variations off and solid precipitation trends of the type obtained in the STERAO experiment could enable us to determine the nature of the dominant glaciation process operative in the thunderclouds studied. (c) 2005 Elsevier B.V All rights reserved. C1 Univ Alabama, Ctr Earth Syst Sci, Huntsville, AL 35899 USA. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35899 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. UMIST, Dept Phys, Manchester M60 1QD, Lancs, England. RP Deierling, W (reprint author), Univ Alabama, Ctr Earth Syst Sci, 320 Sparkman Dr, Huntsville, AL 35899 USA. EM deierling@nsstc.uah.edu; latham@ucar.edu; Walt.Petersen@msfc.nasa.gov; sellis@ucar.edu; Hugh.Christian@msfc.nasa.gov NR 40 TC 23 Z9 27 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 JUL-AUG PY 2005 VL 76 IS 1-4 BP 114 EP 126 DI 10.1016/j.atmosres.2004.11.023 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 958IQ UT WOS:000231438300009 ER PT J AU Mushtak, V Williams, ER Boccippio, DJ AF Mushtak, V Williams, ER Boccippio, DJ TI Latitudinal variations of cloud base height and lightning parameters in the tropics SO ATMOSPHERIC RESEARCH LA English DT Article; Proceedings Paper CT 12th International Conference on Atmospheric Electricity (ICAE) CY JUN 09-12, 2003 CL Versailles, FRANCE DE lightning; intracloud lightning; cloud-to-ground lightning; tropical convection ID THUNDERSTORMS; SATELLITE; RATIO AB The observed reduction in cloud-to-ground lightning in the near-equatorial zone is examined from the perspective of the width of the main negative charge region. Thermodynamic observations of cloud base height also show a climatological minimum value in the near-equatorial region. The association of low cloud bases with both narrow updrafts and narrow charging zones may impede the bridging of the large air gap to ground, and thereby suppress cloud-to-ground lightning activity. This width dependence may be more important than the similar to 10% variation in height of the freezing level in encouraging flashes to ground. (c) 2005 Elsevier B.V. All rights reserved. C1 MIT, Cambridge, MA USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35805 USA. RP MIT, 77 Massachusetts Ave, Cambridge, MA USA. EM earlew@ll.mit.edu NR 23 TC 12 Z9 13 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 EI 1873-2895 J9 ATMOS RES JI Atmos. Res. PD JUL-AUG PY 2005 VL 76 IS 1-4 BP 222 EP 230 DI 10.1016/j.atmosres.2004.11.010 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 958IQ UT WOS:000231438300014 ER PT J AU Williams, E Mushtak, V Rosenfeld, D Goodman, S Boccippio, D AF Williams, E Mushtak, V Rosenfeld, D Goodman, S Boccippio, D TI Thermodynamic conditions favorable to superlative thunderstorm updraft, mixed phase microphysics and lightning flash rate SO ATMOSPHERIC RESEARCH LA English DT Article; Proceedings Paper CT 12th International Conference on Atmospheric Electricity (ICAE) CY JUN 09-12, 2003 CL Versailles, FRANCE DE lightning; thermodynamics; positive flashes; hail; global electrical circuit; aerosol ID MOBILE SOUNDING OBSERVATIONS; WESTERN UNITED-STATES; CLOUD ELECTRIFICATION; FLORIDA THUNDERSTORMS; TROPICAL ATMOSPHERE; TEXAS STORM; HIGH-PLAINS; RADAR; TEMPERATURE; POLARITY AB Satellite observations of lightning flash rate have been merged with proximal surface station thermodynamic observations toward improving the understanding of the response of the updraft and lightning activity in the tropical atmosphere to temperature. The tropical results have led in turn to an examination of thermodynamic climatology over the continental United States in summertime and its comparison with exceptional electrical conditions documented in earlier studies. The tropical and mid-latitude results taken together support an important role for cloud base height in regulating the transfer of convective available potential energy (CAPE) to updraft kinetic energy in thunderstorms. In the tropics, cloud base height is dominated by the dry bulb temperature over the wet bulb temperature as the lightning-regulating temperature in regions characterized by moist convection. In the extratropics, an elevated cloud base height may enable larger cloud water concentrations in the mixed phase region, a favorable condition for the positive charging of large ice particles that may result in thunderclouds with a reversed polarity of the main cloud dipole. The combined requirements of instability and cloud base height serve to confine the region of superlative electrification to the vicinity of the ridge in moist entropy in the western Great Plains. (c) 2005 Elsevier B.V. All rights reserved. C1 MIT, Cambridge, MA 02139 USA. Hebrew Univ Jerusalem, Jerusalem, Israel. NASA Marshall Space Flight Ctr, Huntsville, AL 35805 USA. RP MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM earlew@ll.mit.edu RI Rosenfeld, Daniel/F-6077-2016 OI Rosenfeld, Daniel/0000-0002-0784-7656 NR 78 TC 107 Z9 112 U1 2 U2 18 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 EI 1873-2895 J9 ATMOS RES JI Atmos. Res. PD JUL-AUG PY 2005 VL 76 IS 1-4 BP 288 EP 306 DI 10.1016/j.atmosres.2004.11.009 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 958IQ UT WOS:000231438300018 ER PT J AU Mach, DM Blakeslee, RJ Bailey, JC Farrell, WM Goldberg, RA Desch, MD Houser, JG AF Mach, DM Blakeslee, RJ Bailey, JC Farrell, WM Goldberg, RA Desch, MD Houser, JG TI Lightning optical pulse statistics from storm overflights during the Altus Cumulus Electrification Study SO ATMOSPHERIC RESEARCH LA English DT Article; Proceedings Paper CT 12th International Conference on Atmospheric Electricity (ICAE) CY JUN 09-12, 2003 CL Versailles, FRANCE DE lightning; unmanned aerial vehicle; optical pulse; thunderstorms ID TRANSIENT DETECTOR; PHOTODIODE DETECTOR; FORTE SATELLITE; IMAGING SENSOR; EMISSIONS; FREQUENCY; CLOUDS; SPACE AB The Altus Cumulus Electrification Study (ACES) was conducted during the month of August 2002 in an area near Key West, Florida. One of the goals of this uninhabited aerial vehicle (UAV) study was to collect time resolved optical pulse data from thunderstorms. During the month long campaign, we acquired 5256 lightning generated optical pulses. Most of these observations were made while quite close to the top of the storms. We divided our data into two amplitude groups based on prior NASA U2 aircraft optical data and the pulse characteristics. The group of strong pulses with radiance greater than 2.1 mW m(-2) sr(-1) had mean and median 10-10% optical pulse widths of 770 and 740 mu s, respectively, 50-50% pulse widths of 399 and 355 mu s, respectively, and 10-90% risetimes of 292 and 260 mu s. These values are very similar to the previous U2 based optical results The other group of pulses consisting of slightly more than a quarter of the total pulses observed had radiances less than the minimum values detected in the U2 study. These weak pulses were narrower than the strong pulses with 50-50% mean and median values of 199 and 160 lis, respectively. Only 12% of the flashes observed contained only weak pulses. The source of these weak pulses is unknown, but we suspect that some are artifacts of the close proximity of the aircraft to cloud top. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Alabama, Huntsville, AL 35899 USA. NASA Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Raytheon ITSS, Huntsville, AL 35805 USA. NASA Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Univ Alabama, Huntsville, AL 35899 USA. EM douglas.mach@msfc.nasa.gov RI Goldberg, Richard /E-1881-2012; Farrell, William/I-4865-2013 NR 18 TC 18 Z9 21 U1 0 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 EI 1873-2895 J9 ATMOS RES JI Atmos. Res. PD JUL-AUG PY 2005 VL 76 IS 1-4 BP 386 EP 401 DI 10.1016/j.atmosres.2004.11.039 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 958IQ UT WOS:000231438300024 ER PT J AU Goodman, SJ Blakeslee, R Christian, H Koshak, W Bailey, J Hall, J McCaul, E Buechler, D Darden, C Burks, J Bradshaw, T Gatlin, P AF Goodman, SJ Blakeslee, R Christian, H Koshak, W Bailey, J Hall, J McCaul, E Buechler, D Darden, C Burks, J Bradshaw, T Gatlin, P TI The North Alabama Lightning Mapping Array: Recent severe storm observations and future prospects SO ATMOSPHERIC RESEARCH LA English DT Article; Proceedings Paper CT 12th International Conference on Atmospheric Electricity (ICAE) CY JUN 09-12, 2003 CL Versailles, FRANCE DE total lightning activity; thunderstorms; severe weather applications; forecasting AB The North Alabama Lightning Mapping Array became operational in November 2001 as a principal component of a severe weather test bed to infuse new science and technology into the short-term forecasting of severe and hazardous weather, principally within nearby National Weather Service forecast offices. Since the installation of the LMA, it has measured the total lightning activity of a large number of severe weather events, including three supercell tornado outbreaks, two supercell hailstorm events, and numerous microburst-producing storms and ordinary non-severe thunderstorms. The key components of evolving storm morphology examined are the time rate-of-change (temporal trending) of storm convective and precipitation characteristics that can be diagnosed in real-time using NEXRAD WSR-88D Doppler radar (echo growth and decay, precipitation structures and velocity features, outflow boundaries), LMA (total lightning flash rate and its trend) and National Lightning Detection Network (cloud-to-ground lightning, its polarity and trends). For example, in a transitional season supercell tornado outbreak, peak total flash rates for typical supercells in Tennessee reached 70-100 min(-1) and increases in the total flash rate occurred during storm intensification as much as 20-25 min prior to at least some of the tornadoes. The most intense total flash rate measured during this outbreak (over 800 flashes min(-1)) occur-red in a storm in Alabama. In the case of a severe summertime pulse thunderstorm in North Alabama, the peak total flash rate reached 300 min(-1), with a strong increase in total lightning evident some 9 min before damaging winds were observed at the surface. In this paper, we provide a sampling of LMA observations and products during severe weather events to illustrate the capability of the system, and discuss the prospects for improving the short-term forecasting of convective weather using total lightning data. (c) 2005 Elsevier B.V. All rights reserved. C1 NASA Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. Natl Space Sci & Technol Ctr, Global Hydrol & Climate Ctr, Huntsville, AL 35805 USA. Natl Space Sci & Technol Ctr, Natl Weather Serv Forecast Off, Huntsville, AL 35805 USA. RP Goodman, SJ (reprint author), NASA Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM steven.goodman@nasa.gov OI Gatlin, Patrick/0000-0001-9345-1457 NR 12 TC 66 Z9 71 U1 0 U2 6 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 JUL-AUG PY 2005 VL 76 IS 1-4 BP 423 EP 437 DI 10.1016/j.atmosres.2004.11.035 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 958IQ UT WOS:000231438300027 ER PT J AU Landi, E Bhatia, AK AF Landi, E Bhatia, AK TI Atomic data and spectral line intensities for Ca XIV SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID NITROGEN ISOELECTRONIC SEQUENCE; EXTREME-ULTRAVIOLET SPECTRA; EMISSION-LINES; COLLISION STRENGTHS; DIPOLE TRANSITIONS; RATE COEFFICIENTS; CROSS-SECTIONS; SOLAR-FLARE; IONS; CHIANTI AB Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for Ca XIV. The configurations used are 2s(2)2p(3), 2s2p(4), 2p(5), 2s(2)2p(2)3s, 2s(2)2p(2)3p, 2s(2)2p(2)3d, and 2s2p(3)3s giving rise to 91 fine-structure levels in intermediate coupling. Collision strengths are calculated at five incident energies: 45, 90, 135, 180, and 225 Ry. Excitation rate coefficients are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. Using the excitation rate coefficients and the radiative transition rates, statistical equilibrium equations for level populations are solved at electron densities covering the range of 10(8)-10(14) cm(-3) at an electron temperature of log Te (K) = 6.5, corresponding to a maximum abundance of Ca XIV. Relative and absolute spectral line intensities are calculated and compared with observations of a solar active region and of tokamak plasma. (c) 2005 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. ARTEP Inc, Columbia, MD 21044 USA. USN, Res Lab, Washington, DC 20375 USA. RP Bhatia, AK (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM Anand.K.Bhatia@nasa.gov RI Landi, Enrico/H-4493-2011 NR 30 TC 7 Z9 7 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 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD JUL PY 2005 VL 90 IS 2 BP 177 EP 258 DI 10.1016/j.adt.2005.07.001 PG 82 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA 970XN UT WOS:000232345800001 ER PT J AU Hamilton, DR Murray, JD Kapoor, D Kirkpatrick, AW AF Hamilton, DR Murray, JD Kapoor, D Kirkpatrick, AW TI Cardiac health for astronauts: Current selection standards and their limitations SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Review DE astronauts; acute coronary syndrome; blood pressure; cholesterol; coronary disease; coronary artery disease; LDL cholesterol; spaceflight ID CORONARY-HEART-DISEASE; C-REACTIVE PROTEIN; BEAM COMPUTED-TOMOGRAPHY; ASYMPTOMATIC YOUNG MEN; CARDIOVASCULAR-DISEASE; PRIMARY PREVENTION; MYOCARDIAL-ISCHEMIA; ARTERY CALCIUM; RISK-FACTORS; FOLLOW-UP AB Introduction: The screening tests for coronary artery disease (CAD) for applicants and the active astronaut corps are similar to those performed in the 1960s. Due to the limited treatment and return capabilities of most space vehicles, an in-flight cardiac event would result in mission failure. Improved CAD screening of astronauts is, therefore, paramount to long-duration mission success. Methods: Literature review was performed to compare active and retired astronaut populations to other asymptomatic low-risk cohorts. All populations were examined to determine the incidence and prevalence of CAD. Framingham risk scores were calculated in NASA's active and retired astronaut corps and compared with age- and gender-matched controls. Results: The current standards used for astronaut selection have been successful in creating a cohort that has less risk than their age- and gender-matched counterparts from the general population. However, the existing astronaut cardiovascular screening and selection tests do not adequately rule out CAD for long-duration missions, and, therefore, a "significant" risk of cardiac event remains, especially as we look toward Exploration Class missions. Conclusions. The current astronaut selection and retention standards may not adequately prevent cardiac events from occurring with the longer duration flights. Future research should be directed toward increasing the primary and secondary prevention of CAD in the astronaut cohort. In the meantime, the space program should evaluate the use of more aggressive terrestrial screening tools. It is important not to remove all older, experienced pilots from spaceflight crews unless overt or predictable pathology has been clearly identified. C1 NASA, Adv Projects, WYLE Labs, Houston, TX 77058 USA. Univ Calgary, Foothills Hosp, Dept Surg, Calgary, AB, Canada. Univ Calgary, Foothills Hosp, Dept Crit Care Med, Calgary, AB, Canada. Univ Utah Hosp, Dept Internal Med, Salt Lake City, UT USA. RP NASA, Adv Projects, WYLE Labs, 1290 Hercules Dr,Suite 120, Houston, TX 77058 USA. EM dhamilton@wylehou.com NR 123 TC 4 Z9 9 U1 2 U2 2 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 EI 1943-4448 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUL PY 2005 VL 76 IS 7 BP 615 EP 626 PG 12 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 941WM UT WOS:000230244900001 PM 16018343 ER PT J AU Gontcharov, IB Kovachevich, IV Pool, SL Navinkov, CL Barratt, MR Bogomolov, VV House, N AF Gontcharov, IB Kovachevich, IV Pool, SL Navinkov, CL Barratt, MR Bogomolov, VV House, N TI In-flight medical incidents in the NASA-Mir program SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE astronaut; cosmonaut; emergency medicine; environmental monitoring; illness/injury/trauma; medical kit; medical monitoring; spaceflight; space medicine AB This paper summarizes medical experience during the six NASA-Mir flights from March 14, 1995, to June 4, 1998. There were 7 U.S. astronauts who were part of 6 Mir space crews and worked jointly with 12 Russian cosmonauts. Advances in space medicine have created a safer environment; however, experience shows that crewmembers experience traumatic injuries and illnesses of diverse etiologies during spaceflight. During these joint flights both Russian and U.S. medical kits were available to crewmembers who could access either medical kit as appropriate. The Russian medical team had primary responsibility for monitoring and care of all crewmembers and analyzing medical results. When medical incidents occurred, the appropriate Russian or U.S. medical team determined the plan for diagnosis and treatment. Each team kept the other informed regarding medical situations during the flights and strictly observed the principles of medical confidentiality. A summary of medical incidents by programmatic element is described as experienced by the crewmembers and the ground support medical teams. The most frequent medical cases were small traumatic injuries to the skin and mucous membranes and fluctuations in the cardiovascular system, manifesting primarily in the form of cardiac dysrhythmias. The ability to use both the Russian medical aids and the U.S. medical kit significantly increased the effectiveness and reliability of therapeutic and prophylactic care. The degree of medical care and cooperation established precedents for integrating these systems for the medical support of expeditions on the International Space Station. C1 NASA, Lyndon B Johnson Space Ctr, Astronaut Off, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Tietronix, Houston, TX 77058 USA. State Sci Ctr Russian Federat, Inst Biomed Problems, Moscow, Russia. NASA, Kennedy Space Ctr, Cape Canaveral, FL USA. RP Pool, SL (reprint author), NASA, Lyndon B Johnson Space Ctr, Astronaut Off, Code SA,2100 NASA Pkwy, Houston, TX 77058 USA. EM sam.l.pool@nasa.gov NR 12 TC 8 Z9 10 U1 1 U2 6 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUL PY 2005 VL 76 IS 7 BP 692 EP 696 PG 5 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 941WM UT WOS:000230244900014 PM 16018356 ER PT J AU Lacap, DC Smith, GJD Warren-Rhodes, K Pointing, SB AF Lacap, DC Smith, GJD Warren-Rhodes, K Pointing, SB TI Community structure of free-floating filamentous cyanobacterial mats from the Wonder Lake geothermal springs in the Philippines SO CANADIAN JOURNAL OF MICROBIOLOGY LA English DT Article DE cyanobacteria; Fischerella; geothermal springs; microbial mats; Oscillatoria ID GRADIENT GEL-ELECTROPHORESIS; RNA-DEFINED POPULATIONS; BLUE-GREEN ALGAE; BIODIVERSITY AB Cyanobacterial mats were characterized from pools of 45-60 degrees C in near-neutral pH, low-sulphide geothermal springs in the Philippines. Mat structure did not vary with temperature. All mats possessed highly ordered layers of airspaces at both the macroscopic and microscopic level, and these appear to be an adaptation to a free-floating growth habit. Upper mat layers supported biomass with elevated carotenoid:chlorophyll alpha ratios and an as yet uncharacterized waxy layer on the dorsal surface. Microscopic examination revealed mats comprised a single Fischerella morphotype, with abundant heterocysts throughout mats at all temperatures. Molecular analysis of mat community structure only partly matched morphological identification. All samples supported greater 16S rDNA-defined diversity than morphology suggested, with a progressive loss in the number of genotypes with increasing temperature. Fischerella-like sequences were recovered from mats occurring at all temperatures, but some mats also yielded Oscillatoria-like sequences, although corresponding phenotypes were not observed. Phylogenetic analysis revealed that Fischerella-like sequences were most closely affiliated with Fischerella major and the Oscillatoria-like sequences with Oscillatoria amphigranulata. C1 Univ Hong Kong, Extremophiles Res Grp, Dept Ecol & Biodivers, Hong Kong, Hong Kong, Peoples R China. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Pointing, SB (reprint author), Univ Hong Kong, Extremophiles Res Grp, Dept Ecol & Biodivers, Pokfulam Rd, Hong Kong, Hong Kong, Peoples R China. EM pointing@hkucc.hku.hk OI Smith, Gavin JD/0000-0001-5031-468X NR 33 TC 9 Z9 11 U1 0 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4166 J9 CAN J MICROBIOL JI Can. J. Microbiol. PD JUL PY 2005 VL 51 IS 7 BP 583 EP 589 DI 10.1139/W05-038 PG 7 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Immunology; Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Immunology; Microbiology GA 965YB UT WOS:000231985700008 PM 16175207 ER PT J AU Aalburg, C Diez, FJ Faeth, GM Sunderland, PB Urban, DL Yuan, ZG AF Aalburg, C Diez, FJ Faeth, GM Sunderland, PB Urban, DL Yuan, ZG TI Shapes of nonbuoyant round hydrocarbon-fueled laminar-jet diffusion flames in still SO COMBUSTION AND FLAME LA English DT Article DE laminar diffusion flames; nonbuoyant flames; soot-containing flames; flame shapes; flame structure; microgravity ID SOOT FORMATION; MICROGRAVITY; BEHAVIOR; BUOYANT; AIR AB The soot-luminosity boundaries (near the laminar smoke-point condition) of steady nonbuoyant round hydrocarbon/air laminar-jet diffusion flames at microgravity were found from color video images obtained on orbit during three flights of the Space Shuttle Columbia (flights STS-83, STS-94, and STS-107); these test conditions included ethylene- and propane-fueled flames burning in still air at an ambient temperature of 300 K, ambient pressures of 35-130 kPa, jet exit diameters of 0.40-2.70 mm, and jet exit Reynolds numbers of 46-1186 to yield steady round flames, with most of the flames near the laminar smoke-point condition (including flames both emitting and not emitting soot). These results were supplemented by observations of the flame-sheet locations (locations where the local mixture fraction is stoichiometric) of nonbuoyant round soot-free and soot-containing hydrocarbon/air laminar-jet diffusion flames at microgravity found from filtered color images (at the CH line or 430 +/- 5 nm) obtained using a 2.2-s free-fall facility; these test conditions included methane-, ethane-, and propane-fueled flames burning in still air at an ambient temperature of 300 K, ambient pressures of 25-98 kPa, jet exit diameters of 0.42-3.25 mm, and jet exit Reynolds numbers of 10-625. Simplified expressions to estimate soot-luminosity boundaries (near the laminar smoke-point condition) and flame-sheet locations were obtained using the classic analysis of D.B. Spalding (Combustion and Mass Transfer, Pergamon, New York, 1979, p. 185), extended empirically to account for the presence of soot luminosity for flames near the laminar smoke-point condition. The extended Spalding analysis provided good correlations of both soot-luminosity boundaries (near the laminar smoke-point condition) and flame-sheet locations for flames having short characteristic residence times where radiative heat losses from the flames were small. These results showed that soot-luminosity lengths near the laminar smoke-point condition were roughly twice as long as the flame-sheet location for both soot-free (blue) and soot-containing flames under comparable conditions due to the presence of luminous soot particles beyond the flame sheet within the fuel-lean portion of the flames. (c) 2005 The Combustion Institute. Published by Elsevier Inc. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Michigan, Ann Arbor, MI 48109 USA. RP Urban, DL (reprint author), NASA, Glenn Res Ctr, Mail Stop 77-5,2100 Brookpk Rd, Cleveland, OH 44135 USA. EM david.urban@grc.nasa.gov OI Ismail, Mostafa/0000-0001-7530-9764; Sunderland, Peter/0000-0002-8262-7100 NR 26 TC 10 Z9 11 U1 0 U2 7 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD JUL PY 2005 VL 142 IS 1-2 BP 1 EP 16 DI 10.1016/j.combustflame.2004.12.009 PG 16 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 936SC UT WOS:000229874700001 ER PT J AU Grant, LB Gould, MM Donnellan, A McLeod, D Chen, AYA Sung, SS Pierce, M Fox, GC Rundle, P AF Grant, LB Gould, MM Donnellan, A McLeod, D Chen, AYA Sung, SS Pierce, M Fox, GC Rundle, P TI A web service's-based universal approach to heterogeneous fault databases SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article ID SIMULATION AB QuakeSim lets scientists study earthquake behavior over single or multiple seismic cycles. The system's semantics-based database component, QuakeTables, provides global realtime accessibility to a diverse set of earthquake and fault data. C1 Univ Calif Irvine, Dept Environm Hlth Sci & Policy, Irvine, CA 92717 USA. Jet Prop Lab, Div Sci, Pasadena, CA 91109 USA. Univ So Calif, Integrated Media Syst Ctr, Los Angeles, CA 90089 USA. Indiana Univ, Community Grids Lab, Bloomington, IN 47405 USA. Univ Calif Davis, Davis, CA 95616 USA. RP Grant, LB (reprint author), Univ Calif Irvine, Dept Environm Hlth Sci & Policy, Irvine, CA 92717 USA. EM lgrant@uci.edu; miryha@uci.edu; donnellan@jpl.nasa.gov; mcloed@pollux.usc.edu; yunanche@usc.edu; sangsung@usc.edu; mpierce@cs.indiana.edu; gcf@indiana.edu; paul_rundle@hmc.edu RI Ludwig, Lisa Grant/G-6442-2012; OI Ludwig, Lisa Grant/0000-0001-6538-8067; Pierce, Marlon/0000-0002-9582-5712 NR 16 TC 3 Z9 3 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD JUL-AUG PY 2005 VL 7 IS 4 BP 51 EP 57 DI 10.1109/MCSE.2005.63 PG 7 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 938UA UT WOS:000230027700011 ER PT J AU Shoemaker, WC Bayard, DS Botnen, A Wo, CCJ Gandhi, A Chien, LC Lu, K Martin, MJ Chan, LS Demetriades, D Ahmadpour, N Jelliffe, RW AF Shoemaker, WC Bayard, DS Botnen, A Wo, CCJ Gandhi, A Chien, LC Lu, K Martin, MJ Chan, LS Demetriades, D Ahmadpour, N Jelliffe, RW TI Mathematical program for outcome prediction and therapeutic support for trauma beginning within 1 hr of admission: A preliminary report SO CRITICAL CARE MEDICINE LA English DT Article DE noninvasive hemodynamic monitoring; cardiac index; mean arterial blood pressure; heart rate; pulse oximetry; transcutaneous oxygen and carbon dioxide tensions; outcome prediction; therapeutic decision support system ID CRITICALLY ILL PATIENTS; RISK SURGICAL PATIENTS; OXYGEN DELIVERY; EMERGENCY PATIENTS; SEPTIC SHOCK; TRIAL; VALUES; OPTIMIZATION; CONSUMPTION; MORTALITY AB Objectives: The aims were a) to noninvasively monitor acute emergency trauma patients beginning within 1 hr after admission to the emergency department; b) to prospectively predict outcome; and c) to evaluate the relative effectiveness of various modes of therapy. Design: Prospective outcome prediction study using a mathematical search and display model based on noninvasive hemo-dynamic monitoring. Setting: A level I trauma service in a large university-run inner-city public hospital. Patients: We studied 185 consecutively noninvasively monitored emergency patients. Interventions: We noninvasively monitored cardiac index, mean arterial blood pressure, heart rate, pulse oximetry, and transcutaneous oxygen and carbon dioxide tensions beginning within 1-hr after emergency admission. Measurements and Main Results: The cardiac index, pulse oximetry, transcutaneous oxygen tension, transcutaneous carbon dioxide tension, and mean arterial blood pressure were higher in survivors than in nonsurvivors in the initial resuscitation period and at the hemodynamic nadir. Heart rate and transcutaneous carbon dioxide tension were higher in the nonsurvivors. The calculated survival probability in the first hour observation period of survivors averaged 85 +/- 14% vs. 69 +/- 16% for nonsurvivors (p = .0001). Misclassifications of the series as a whole were 11.3%; after excluding brain death from severe head injury, there were 6.4% misclassifications. A decision support system evaluated the effects of various therapies based on responses of patients with similar clinical-hemodynamic states. Conclusion: Noninvasive hemodynamic monitoring and an information system provided a feasible approach to predict outcome early and to evaluate prospectively the efficacy of various therapies. C1 Univ So Calif, Lab Appl Pharmacokinet, Keck Sch Med, Med Ctr, Los Angeles, CA 90089 USA. Univ So Calif, Dept Surg, Keck Sch Med, Med Ctr, Los Angeles, CA 90089 USA. Jet Propuls Lab, Pasadena, CA USA. RP Shoemaker, WC (reprint author), Univ So Calif, Lab Appl Pharmacokinet, Keck Sch Med, Med Ctr, Los Angeles, CA 90089 USA. RI Martin, Matthew/B-2676-2014 OI Martin, Matthew/0000-0002-9169-9069 FU NCRR NIH HHS [RR-11526]; NIGMS NIH HHS [GM-65619] NR 36 TC 11 Z9 11 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0090-3493 J9 CRIT CARE MED JI Crit. Care Med. PD JUL PY 2005 VL 33 IS 7 BP 1499 EP 1506 DI 10.1097/01.CCM.0000162641.92400.AA PG 8 WC Critical Care Medicine SC General & Internal Medicine GA 947GB UT WOS:000230630300004 PM 16003054 ER PT J AU Crucian, B Sams, C AF Crucian, B Sams, C TI Reduced gravity evaluation of potential spaceflight-compatible flow cytometer technology SO CYTOMETRY PART B-CLINICAL CYTOMETRY LA English DT Article DE zero gravity; spaceflight; flow cytometer ID SUBSETS AB Background: The presence of a spaceflight-compatible flow cytometer onboard the International Space Station would be extremely beneficial for in-flight medicine and reduced gravity research. In the past, commercially available flow cytometers were not suitable for use during spaceflight due to their size, weight, power, and sheath fluid requirements. Recent advances in cytometer technology have enabled features that now make a spaceflight-compatible cytometer possible. We evaluated a small, robust novel cytometer with design features that minimize or eliminate many incompatibilities with spaceflight. This cytometer is highly miniaturized and lightweight, does not require sheath fluid, and uses a low-energy diode laser. The ability to achieve laminar particle flow without sheath fluid is important because an instrument using large liquid volumes and producing an equivalent amount of hazardous liquid waste would not meet spaceflight constraints. Methods: For this study the cytometer was modified so that stained liquid cell samples could be delivered during reduced gravity. The cytometer was then evaluated onboard the NASA KC-135 reduced gravity research aircraft. The KC-135 uses a parabolic flight path to generate essentially zero gravity conditions for 30-s increments. Typically 40 parabolas are flown per mission, resulting in approximately 20 min of reduced gravity during which research may be performed. During this evaluation, bead-based cytometer precision, photomultiplier tube linearity, and leukocyte immunophenotype analysis were performed during reduced gravity. The flight data were then compared with ground-based control data and data generated using a reference cytometer (Beckman-Coulter XL). Results: This novel cytometer functioned well during reduced gravity and produced data comparable to those of ground-based controls with only minor caveats. The reduced gravity cell immunophenotype data were indistinguishable from ground control data and reference cytometric data. Bead-based instrument precision (coefficient of variation) was slightly increased during reduced gravity operation, but not to a degree that would affect most common flow cytometric applications. The ability of the instrument to collect absolute cell counts was validated. Conclusions: This study represents the first generation of real-time flow cytometry data during zero gravity. With modifications, the evaluated cytometer technology could be the basis from which an operational spaceflight-compatible flow cytometer is developed. Published 2005 Wiley-Liss, Inc. C1 NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off SK3, Houston, TX 77058 USA. Wyle Labs, Space Physiol & Countermeasures Dept, Houston, TX USA. RP Sams, C (reprint author), NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off SK3, Houston, TX 77058 USA. EM csams@ems.jsc.nasa.gov NR 5 TC 3 Z9 3 U1 1 U2 5 PU WILEY-LISS PI HOBOKEN PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 1552-4949 J9 CYTOM PART B-CLIN CY JI Cytom. Part B-Clin. Cytom. PD JUL PY 2005 VL 66B IS 1 BP 1 EP 9 DI 10.1002/cyto.b.20057 PG 9 WC Medical Laboratory Technology; Pathology SC Medical Laboratory Technology; Pathology GA 937LA UT WOS:000229924400001 PM 15924305 ER PT J AU Gorman, HS Conway, EM AF Gorman, HS Conway, EM TI Monitoring the environment: Taking a historical perspective SO ENVIRONMENTAL MONITORING AND ASSESSMENT LA English DT Editorial Material DE air pollution monitoring; environmental history; environmental monitoring; history of technology; sustainability ID TECHNOLOGY AB This paper introduces the five papers that follow, all of which were originally presented at a workshop titled "Monitoring the Environment: Scales, Methods, and Systems in Historical Perspective." The workshop, sponsored by the Society for the History of Technology and the American Society for Environmental History, examined past efforts to develop tools, methods, and systems for measuring or monitoring some aspect of the physical environment. Four of the papers included here focus on various aspects of air quality monitoring; the fifth has to do with monitoring the earth from space. Despite differences in time period and approach, each article examines how specific tools and methods - and the motivations for developing those tools and methods - evolved. Among other things, these papers make clear that systems for monitoring various aspects of the physical environment are shaped by a variety of stakeholders and suggest that efforts to construct such systems should not be viewed as a purely technical task. C1 Michigan Technol Univ, Dept Social Sci, Houghton, MI 49931 USA. Jet Prop Lab, Pasadena, CA 91109 USA. RP Gorman, HS (reprint author), Michigan Technol Univ, Dept Social Sci, Houghton, MI 49931 USA. EM hsgorman@mtu.edu NR 30 TC 1 Z9 1 U1 2 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-6369 J9 ENVIRON MONIT ASSESS JI Environ. Monit. Assess. PD JUL PY 2005 VL 106 IS 1-3 BP 1 EP 10 DI 10.1007/s10661-005-0755-0 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA 939RV UT WOS:000230091000001 PM 16001708 ER PT J AU Convertino, VA Ratliff, DA Crissey, J Doerr, DF Idris, AH Lurie, KG AF Convertino, VA Ratliff, DA Crissey, J Doerr, DF Idris, AH Lurie, KG TI Effects of inspiratory impedance on hemodynamic responses to a squat-stand test in human volunteers: implications for treatment of orthostatic hypotension SO EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE respiration; blood pressure; heart rate; stroke volume; cardiac output; peripheral vascular resistance ID DECOMPRESSION CARDIOPULMONARY-RESUSCITATION; BODY NEGATIVE-PRESSURE; THRESHOLD VALVE; HEMORRHAGIC-SHOCK; CARDIAC-ARREST; PORCINE MODEL; STROKE VOLUME; INTOLERANCE; FEASIBILITY; RESISTANCE AB Recent studies in our laboratory demonstrated that spontaneous breathing through an inspiratory impedance threshold device (ITD) increased heart rate (HR), stroke volume (SV), cardiac output (Q), and mean arterial blood pressure (MAP) in supine human subjects. In this study, we tested the effectiveness of an ITD as a countermeasure against development of orthostatic hypotension, provoked using a squat-to-stand test (SST). Using a prospective, randomized blinded protocol, 18 healthy, normotensive volunteers (9 males, 9 females) completed two-counterbalanced 6-min SST protocols with and without (sham) an ITD set to open at 0.7 kPa (7-cm H2O) pressure. HR, SV, Q, total peripheral resistance (TPR), and MAP were assessed noninvasively with infrared finger photoplethysmography. Symptoms were recorded on a 5-point scale (1 = normal; 5 = faint) of subject perceived rating (SPR). The reduction in TPR produced by SST (-35 +/- 5 %) was not affected by the ITD. Reduction in MAP with ITD during the transient phase of the SST (-3.6 +/- 0.5 kPa or -27 +/- 4 mmHg) was less (P = 0.03) than that measured while breathing through a sham device (-4.8 +/- 0.4 kPa or -36 +/- 3 mmHg) despite similar (P < 0.926) elevations in HR of 15 +/- 2 bpm. SV (+2 +/- 4 %) and Q (+22 +/- 5 %) with the ITD were higher (P < 0.04) than SV (-8 +/- 4 %) and Q (+10 +/- 6 %) without the ITD. SPR was 1.4 +/- 0.1 with ITD compared to 2.0 +/- 0.2 with the sham device (P < 0.04). This reduction in orthostatic symptoms with application of an ITD during the SST was associated with higher MAP, SV and Q. Our results demonstrate the potential application of an ITD as a countermeasure against orthostatic hypotension. C1 USA, Inst Surg Res, Ft Sam Houston, TX 78234 USA. NASA, Bionet Corp, Kennedy Space Ctr, FL 32899 USA. NASA, Spaceflight & Life Sci Training Program, Kennedy Space Ctr, FL 32899 USA. NASA, Technol Implementat Branch, Kennedy Space Ctr, FL 32899 USA. Univ Texas, SW Med Ctr, Dept Surg & Emergency Med, Dallas, TX 75235 USA. Univ Minnesota, Dept Emergency Med, Minneapolis, MN 55455 USA. Adv Circulatory Syst Inc, Minneapolis, MN 55455 USA. RP Convertino, VA (reprint author), USA, Inst Surg Res, 3400 Rawley E Chambers Ave,Bldg 3611, Ft Sam Houston, TX 78234 USA. EM victor.convertino@amedd.army.mil OI Idris, Ahamed/0000-0001-7113-6499 NR 35 TC 34 Z9 34 U1 0 U2 8 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1439-6319 J9 EUR J APPL PHYSIOL JI Eur. J. Appl. Physiol. PD JUL PY 2005 VL 94 IS 4 BP 392 EP 399 DI 10.1007/s00421-005-1344-1 PG 8 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 939KP UT WOS:000230071900006 PM 15864634 ER PT J AU Liang, MTC Arnaud, SB Steele, CR Hatch, P Moreno, A AF Liang, MTC Arnaud, SB Steele, CR Hatch, P Moreno, A TI Ulnar and tibial bending stiffness as an index of bone strength in synchronized swimmers and gymnasts SO EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE biomechanics; mechanical loading; exercise; muscle; young women ID MUSCLE STRENGTH; MINERAL DENSITY; NONINVASIVE DETERMINATION; IMPACT; WOMEN; VALIDATION; MODEL AB The purpose of this study is to compare a mechanical property of bone in world-class female athletes with different loading histories. Bone bending stiffness or EI (E is the modulus of elasticity and I, the moment of inertia) was measured noninvasively with the mechanical response tissue analyzer, that analyzes the response of bone to a vibratory stimulus. We evaluated the ulna, ulnar width, wrist density and tibia in 13 synchronized swimmers (SYN), eight gymnasts (GYM) and 16 untrained women (UNT) of similar age. Muscle strength in the flexors and extensors at elbows and knees was measured in the athletes. SYN were taller than GYM or UNT (168 +/- 0.7 vs. 152 +/- 1.1 or 157 +/- 1.2 cm, P < 0.01). Ulnar EI, Nm(2), was similar in SYN and GYM (41 +/- 5.4 vs. 42 +/- 4.2, NS) and 50% higher than in UNT (27 +/- 2.1, P < 0.05). Ulnar EI, Nm(2) was related to ulnar width (r = 0.497, P < 0.002, n = 37) but not to wrist density. Tibial EI, Nm(2), in SYN and GYM (270 +/- 42 vs. 285 +/- 49, NS) was similar and more than twice as high as in UNT (119 +/- 6; p < 0.05). Knee flexor strength measured at 60 degrees s(-1) and elbow extensor strength at 200 degrees s(-1) correlated with tibial EI (r = 0.44 and 0.41, P < 0.05). In spite of different loading histories, the tibiae and ulnas of world-class athletes showed similar high values for bending stiffness that exceeded values in untrained women. EI in the ulna could be related to bone width and in the tibia, to muscle strength. C1 NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. Calif State Polytech Univ Pomona, Dept Kinesiol & Hlth Promot, Pomona, CA 91768 USA. Stanford Univ, Div Appl Mech, Stanford, CA 94305 USA. RP Arnaud, SB (reprint author), NASA, Ames Res Ctr, Div Life Sci, SLR 239-11, Moffett Field, CA 94035 USA. EM sarnaud@mail.arc.nasa.gov FU NIGMS NIH HHS [5 S0 GM053933-06] NR 26 TC 12 Z9 13 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1439-6319 J9 EUR J APPL PHYSIOL JI Eur. J. Appl. Physiol. PD JUL PY 2005 VL 94 IS 4 BP 400 EP 407 DI 10.1007/s00421-005-1351-2 PG 8 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 939KP UT WOS:000230071900007 PM 15864633 ER PT J AU Sundaresan, A Pellis, NR AF Sundaresan, A Pellis, NR TI The role of the upstream T cell protein tyrosine kinase ZAP 70 in analog microgravity SO FEBS JOURNAL LA English DT Meeting Abstract CT IUBMB 50th Anniversary Symposium CY JUL 02-07, 2005 CL Budapest, HUNGARY SP Int Union Biochem Molecular Biol C1 Univ Space Res Assoc, Div Space & Life Sci, Lab Cellular Movement & Signal Transduct, Houston, TX USA. NASA, Lyndon B Johnson Space Ctr, Biol Syst Off, Lab Cellular Movement & Signal Transduct, Houston, TX 77058 USA. EM alamelu.sundaresan1@jsc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1742-464X J9 FEBS J JI FEBS J. PD JUL PY 2005 VL 272 SU 1 BP 315 EP 315 PG 1 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 005MG UT WOS:000234826101596 ER PT J AU Hawkins, SL Heifetz, J Kondzela, CM Pohl, JE Wilmot, RL Katugin, ON Tuponogov, VN AF Hawkins, SL Heifetz, J Kondzela, CM Pohl, JE Wilmot, RL Katugin, ON Tuponogov, VN TI Genetic variation of rougheye rockfish (Sebastes aleutianus) and shortraker rockfish (S-borealis) inferred from allozymes SO FISHERY BULLETIN LA English DT Article ID POPULATION-STRUCTURE; PACIFIC-OCEAN; PATTERNS; ELECTROPHORESIS; GENUS; GULF; FISH AB Rougheye rockfish (Sebastes aleutianus) and shortraker rockfish (Sebastes borealis) were collected from the Washington coast, the Gulf of Alaska, the southern Bering Sea, and the eastern Kamchatka coast of Russia (areas encompassing most of their geographic distribution) for population genetic analyses. Using starch gel electrophoresis, we analyzed 1027 rougheye rockfish and 615 shortraker rockfish for variation at 29 protein-coding loci. No genetic heterogeneity was found among shortraker rockfish throughout the sampled regions, although shortraker in the Aleutian Islands region, captured at deeper depths, were found to be significantly smaller in size than the shortraker caught in shallower waters from Southeast Alaska. Genetic analysis of the rougheye rockfish revealed two evolutionary lineages that exist in sympatry with little or no gene flow between them. When analyzed as two distinct species, neither lineage exhibited heterogeneity among regions. Sebastes aleutianus seems to inhabit waters throughout the Gulf of Alaska and more southern waters, whereas S. sp. cf. aleutianus inhabits waters throughout the Gulf of Alaska, Aleutian Islands, and Asia. The distribution of the two rougheye rockfish lineages may be related to depth where they are sympatric. The paler color morph, S. aleutianus, is found more abundantly in shallower waters and the darker color morph, Sebastes sp. cf. aleutianus, inhabits deeper waters. Sebastes sp. cf. aleutianus, also exhibited a significantly higher prevalence of two parasites, N. robusta and T trituba, than did Sebastes aleutianus, in the 2001 samples, indicating a possible difference in habitat and (or) resource use between the two lineages. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. TINRO Ctr, Pacific Res Fisheries Ctr, Vladivostok 690950, Russia. RP Hawkins, SL (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM Sharon.Hawkins@noaa.gov NR 36 TC 13 Z9 13 U1 0 U2 1 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 JUL PY 2005 VL 103 IS 3 BP 524 EP 535 PG 12 WC Fisheries SC Fisheries GA 949JO UT WOS:000230781500005 ER PT J AU Kappler, A Emerson, D Edwards, K Amend, JP Gralnick, JA Grathwohl, P Hoehler, T Straub, KL AF Kappler, A. Emerson, D. Edwards, K. Amend, J. P. Gralnick, J. A. Grathwohl, P. Hoehler, T. Straub, K. L. TI Microbial activity in biogeochemical gradients - new aspects of research SO GEOBIOLOGY LA English DT Article AB In April 2004, the German Research Foundation (DFG) and the National Science Foundation (NSF) co-organized a meeting for US and German junior geoscientists in Washington DC. As an outcome of this Research Conference titled 'Earth, Fire, Water, Air and Life', a follow-up workshop took place in May 2005 at the Eberhard-Karls University of Tuebingen in Germany. This workshop covered new aspects of research to improve the understanding of steep biogeochemical gradients covering pH changes, redox zones, as well as solute and particulate concentration variations in aqueous systems. Detailed understanding of biogeochemistry in this context delivers new fundamental aspects in interdisciplinary research. Such work is also urgently needed to control ever-increasing scarcity of water that is to large parts driven by decreasing water quality. Research ideas on gradients in a biogeochemical context that were discussed by a subgroup of biogeochemists during that workshop are summarized and presented here. C1 [Kappler, A.; Grathwohl, P.; Straub, K. L.] Univ Tubingen, Ctr Appl Geosci, Tubingen, Germany. [Emerson, D.] Amer Type Culture Collect, Manassas, VA USA. [Edwards, K.] Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. [Amend, J. P.] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. [Gralnick, J. A.] Univ Minnesota, Dept Microbiol, St Paul, MN 55108 USA. [Gralnick, J. A.] Univ Minnesota, Inst Biotechnol, St Paul, MN 55108 USA. [Hoehler, T.] NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA USA. RP Kappler, A (reprint author), Univ Tubingen, Ctr Appl Geosci, Tubingen, Germany. EM andreas.kappler@uni-tuebingen.de RI Kappler, Andreas/G-7221-2016 FU Deutsche Forschungsgemeinschaft (DFG) FX We gratefully acknowledge funds from the Deutsche Forschungsgemeinschaft (DFG) for enabling the biogeochemical gradients workshop. NR 25 TC 14 Z9 14 U1 1 U2 17 PU WILEY-BLACKWELL PUBLISHING, INC PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1472-4677 J9 GEOBIOLOGY JI Geobiology PD JUL PY 2005 VL 3 IS 3 BP 229 EP 233 DI 10.1111/j.1472-4669.2005.00053.x PG 5 WC Biology; Environmental Sciences; Geosciences, Multidisciplinary SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Geology GA V06CO UT WOS:000207171900006 ER PT J AU Gounelle, M Engrand, C Alard, O Bland, PA Zolensky, ME Russell, SS Duprat, J AF Gounelle, M Engrand, C Alard, O Bland, PA Zolensky, ME Russell, SS Duprat, J TI Hydrogen isotopic composition of water from fossil micrometeorites in howardites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID INTERPLANETARY DUST PARTICLES; HIGHLY SIDEROPHILE ELEMENTS; EARTHS UPPER-MANTLE; S-TYPE ASTEROIDS; CARBONACEOUS CHONDRITES; SOLAR-SYSTEM; COSMIC SPHERULES; ION MICROPROBE; PARENT BODIES; CM CHONDRITE AB We have measured the hydrogen isotopic composition (D/H ratios) of the water from 13 carbonaceous chondritic microclasts (CCMs, size <1 mm) trapped in two howardites (Kapoeta and Yamato-793497) early in the evolution of Solar System. The division into tochilinite-rich; magnetite-rich, olivine-poor; magnetite-rich, olivine-rich CCM types is corroborated by the hydrogen isotopic compositions. Both mineralogy and hydrogen isotopic compositions demonstrate that tochilinite-rich CCMs represent CM2 chondritic matter. In contrast, there is no good match between the isotopic and mineralogical properties of the magnetite-rich CCMs and the known groups of carbonaceous chondrites, suggesting that magnetite-rich CCMs represent a new kind of chondritic matter, not yet sampled in meteorite collections. This demonstrates that the view of the asteroid belt revealed by the collection of meteorites is incomplete. The study of (micro)clasts offers a unique opportunity to better decipher the nature and relative abundance of asteroids. The average hydrogen isotopic composition of water belonging to CCMs, D/H = (152.0 +/- 4.8) X 10(-6) (1 sigma(m)), is similar to that of Antarctic micrometeorites (AMMs), D/H = (161.2 +/- 3.8) X 10(-6) (1 sigma(m)). The similarity, in terms of mineralogy and hydrogen isotopic composition, between CCMs and AMMs demonstrates that the composition of the micrometeorites has not been modified over the whole history of the Solar System. It indicates that the composition of the micrometeorite flux onto Earth has been, and is, dominated by a mixture of CM2-like; magnetite-rich, olivine-poor; magnetite-rich, olivine-rich carbonaceous chondritic matter exemplified by CCMs found in howardites. Because CCMs have not suffered atmospheric entry, they provide an abundant source of pristine micrometeorites. The average D/H ratio of the whole population of CCMs is identical within errors to that of the Earth (149 +/- 3 X 10(-6)). The match between the CCMs D/H ratio and that of the Earth is especially remarkable because 1) three different populations of CCMs are needed to make the D/H ratio of the Earth; 2) there is no single carbonaceous chondrite group for which a similar match exists. This observation suggests that CCMs population might be representative of the late veneer agent(s) that delivered water to the Earth. Copyright (C) 2005 Elsevier Ltd. C1 CSNSM, F-91405 Orsay, France. Univ Paris 11, F-91405 Orsay, France. Nat Hist Museum, Dept Mineral, London SW7 5BD, England. Open Univ, Dept Earth Sci, Milton Keynes MK7 6AA, Bucks, England. Univ London Imperial Coll Sci Technol & Med, Dept Earth Sci & Engn, London SW7 2AZ, England. NASA, Lyndon B Johnson Space Ctr, KT, Houston, TX 77058 USA. RP CSNSM, Batiment 104, F-91405 Orsay, France. EM gounelle@csnsm.in2p3.fr RI ALARD, Olivier/A-7128-2008 OI ALARD, Olivier/0000-0002-0832-6625 NR 88 TC 19 Z9 20 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUL 1 PY 2005 VL 69 IS 13 BP 3431 EP 3443 DI 10.1016/j.gca.2004.12.021 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 944ZS UT WOS:000230470500018 ER PT J AU Kouchinsky, A Bengtson, S Pavlov, V Runnegar, B Val'kov, A Young, E AF Kouchinsky, A Bengtson, S Pavlov, V Runnegar, B Val'kov, A Young, E TI Pre-Tommotian age of the lower Pestrotsvet Formation in the Selinde section on the Siberian platform: carbon isotopic evidence SO GEOLOGICAL MAGAZINE LA English DT Article DE Cambrian; Precambrian; carbon; isotope ratios; stratigraphy ID PRECAMBRIAN-CAMBRIAN BOUNDARY; NORTHERN SIBERIA; UNCONFORMITY; CALIBRATION; EVENTS; BEDS AB Carbon isotopic data from the Selinde section in the southeastern part of the Siberian platform area are correlated with the reference isotopic profile from the Lower Cambrian stratotype sections of the Lena-Aldan region, but also show additional delta(13)C excursions unrecognized there. The chemostratigraphic correlation suggests that the geological and fossil record of the lower Pestrotsvet Formation in the Selinde section has a deeper history than the stratotype region. This conclusion is important for both constraining the age of the earliest Cambrian marine transgression on the Siberian platform and providing a clearer understanding of the pace and order of early Cambrian geochemical and biological events. C1 Swedish Museum Nat Hist, Dept Palaezool, SE-10405 Stockholm, Sweden. Univ Calif Los Angeles, Ctr Astrobiol, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Inst Earth Phys, Moscow 123995, Russia. NASA, Astrobiol Inst, Ames Res Ctr, Moffett Field, CA 94035 USA. Russian Acad Sci, Inst Geol Sci, Siberian Branch, Yakutsk 677020, Sakha, Russia. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. RP Kouchinsky, A (reprint author), Swedish Museum Nat Hist, Dept Palaezool, Box 50007, SE-10405 Stockholm, Sweden. EM akouchin@ucla.edu RI Koroleva, Olga/C-1306-2012; OI Bengtson, Stefan/0000-0003-0206-5791 NR 35 TC 19 Z9 21 U1 0 U2 8 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0016-7568 J9 GEOL MAG JI Geol. Mag. PD JUL PY 2005 VL 142 IS 4 BP 319 EP 325 DI 10.1017/S0016756805000865 PG 7 WC Geosciences, Multidisciplinary SC Geology GA 976UC UT WOS:000232757900001 ER PT J AU Watts, DR Harris, NBW AF Watts, DR Harris, NBW CA 2002 NASA GLENN SOARS Woking Grp TI Mapping granite and gneiss in domes along the North Himalayan antiform with ASTER SWIR band ratios SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article DE Himalaya; dome; granite; ASTER; SWIR band ratio ID SOUTHERN TIBET; KANGMAR DOME; METAMORPHISM; TECTONICS; ORIGIN AB A series of five gneiss domes that are exposed along the axis of the North Himalayan antiform 50 km south of the Indus-Tsangpo suture, southern Tibet, are characterized by cores of Cambrian gneiss and Neoproterozoic-Paleozoic schists and migmatites, often intruded by Tertiary granites and mantled by metamorphosed equivalents of Tethyan sedimentary successions. Images from the SWIR (short wave infrared) bands recorded by the ASTER (Advanced Spaceborn Thermal Emission and Reflection Radiometer) sensor on the Earth Observation System Terra satellite reveal with unprecedented clarity the nature of the cores of the domes and the extent of the surrounding mantles of metamorphic rock. Using band ratio methods, we distinguish Tertiary granite from Cambrian gneiss on the basis of the presence of 5%-10% muscovite in the granite. This methodology is ideally suited to the mapping of a relatively inaccessible area with excellent exposure but limited ground truth. With the exception of the well-studied Kangmar dome, our images of the cores of the domes and their associated mantles bear little resemblance to the published geological maps of the region and reveal hitherto unrecognized exposures of granites. The true disposition of the domes within the North Himalayan antiform have now been established, revealing a systematic westward increase in the granite component of Himalayan age within the domes across the study area. C1 Wright State Univ, Dept Geol Sci, Dayton, OH 45435 USA. Open Univ, Dept Earth Sci, Milton Keynes MK7 6AA, Bucks, England. NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Watts, DR (reprint author), Wright State Univ, Dept Geol Sci, 3640 Colonel Glenn Highway, Dayton, OH 45435 USA. EM doyle.watts@wright.edu; n.b.w.harris@open.ac.uk RI Harris, Nigel/C-3349-2009 OI Harris, Nigel/0000-0001-9387-2585 NR 26 TC 25 Z9 25 U1 1 U2 7 PU GEOLOGICAL SOC AMER, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0016-7606 EI 1943-2674 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD JUL-AUG PY 2005 VL 117 IS 7-8 BP 879 EP 886 DI 10.1130/B25592.1 PG 8 WC Geosciences, Multidisciplinary SC Geology GA 938HS UT WOS:000229991100004 ER PT J AU Horner-Johnson, BC Gordon, RG Cowles, SM Argus, DF AF Horner-Johnson, BC Gordon, RG Cowles, SM Argus, DF TI The angular velocity of Nubia relative to Somalia and the location of the Nubia-Somalia-Antarctica triple junction SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE Africa; diffuse plate boundary; Nubia; Somalia; Southwest Indian ridge; triple junction ID SOUTHWEST INDIAN RIDGE; CURRENT PLATE MOTIONS; BOUNDARY; AFRICA; KINEMATICS; EVOLUTION; RIFT; SEA AB A new analysis of geologically current plate motion across the Southwest Indian ridge (SWIR) and of the current location of the Nubia-Antarctica-Somalia triple junction is presented. Spreading rates averaged over the past 3.2 Myr are estimated from 103 well-distributed, nearly ridge-perpendicular profiles that cross the SWIR. All available bathymetric data are evaluated to estimate the azimuths and uncertainties of transform faults; six are estimated from multibeam data and 12 from precision depth recorder (PDR) data. If both the Nubian and Somalian component plates are internally rigid near the SWIR and if the Nubia-Somalia boundary is narrow where it intersects the SWIR, that intersection lies between approximate to 26 degrees E and approximate to 32 degrees E. Thus, the boundary is either along the spreading ridge segment just west of the Andrew Bain transform fault complex (ABTFC) or along some of the transform fault complex itself. These limits are narrower than and contained within limits of approximate to 24 degrees E to approximate to 33 degrees E previously found by Lemaux et al. from an analysis of the locations of magnetic anomaly 5. The data are consistent with a narrow boundary, but also consistent with a diffuse boundary as wide as approximate to 700 km. The new Nubia-Somalia pole of rotation lies approximate to 10 degrees north of the Bouvet triple junction, which places it far to the southwest of southern Africa. The new angular velocity determined only from data along the SWIR indicates displacement rates of Somalia relative to Nubia of 3.6 +/- 0.5 mm yr(-1) (95 per cent confidence limits) towards 176 degrees (S04 degrees E) between Somalia and Nubia near the SWIR, and of 8.3 +/- 1.9 mm yr(-1) (95 per cent confidence limits) towards 121 degrees (S59 degrees E) near Afar. The new Nubia-Somalia angular velocity differs significantly from the Nubia-Somalia angular velocity estimated from Gulf of Aden and Red sea data. This significant difference has three main alternative explanations: (i) that the plate motion data have substantial unmodelled systematic errors, (ii) that the Nubian component plate is not a single rigid plate, or (iii) that the Somalian component plate is not a single rigid plate. We tentatively prefer the third explanation given the geographical distribution of earthquakes within the African composite plate relative to the inferred location of the Nubia-Somalia boundary along the SWIR. C1 Rice Univ, Dept Earth Sci, Houston, TX 77005 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gordon, RG (reprint author), Rice Univ, Dept Earth Sci, Houston, TX 77005 USA. EM rgg@rice.edu RI Argus, Donald/F-7704-2011 NR 28 TC 33 Z9 34 U1 0 U2 3 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD JUL PY 2005 VL 162 IS 1 BP 221 EP 238 DI 10.1111/j.1365-246X.2005.02608.x PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 937GR UT WOS:000229913100015 ER PT J AU Jin, Y Roy, DP AF Jin, Y Roy, DP TI Fire-induced albedo change and its radiative forcing at the surface in northern Australia SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MODIS; SAVANNA; BRDF AB This paper investigates the impact of fire on surface albedo and the associated radiative forcing over 56% of continental Australia encompassing the fire-prone northern tropical savanna. Fire-affected areas and albedos are derived for the 2003 fire season using daily Moderate Resolution Imaging Spectroradiometer ( MODIS) surface reflectance data. Near-infrared and total shortwave albedos are observed to generally decrease after fire occurrence. Regionally, the total shortwave albedo drops by an average of 0.024, with increasing reductions as the dry season progresses and larger reductions in grasslands than woody savannas. These fire-induced albedo changes exert a positive forcing at the surface that increases from March to November. A mean "instantaneous'' shortwave surface radiative forcing of 0.52 Wm(-2) is estimated for the study region. C1 Univ Maryland, Dept Geog, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Jin, Y (reprint author), Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92717 USA. EM yufang@uci.edu NR 19 TC 33 Z9 33 U1 2 U2 10 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 JUL 1 PY 2005 VL 32 IS 13 AR L13401 DI 10.1029/2005GL022822 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 945CT UT WOS:000230480100003 ER PT J AU Milesi, C Hashimoto, H Running, SW Nemani, RR AF Milesi, C Hashimoto, H Running, SW Nemani, RR TI Climate variability, vegetation productivity and people at risk SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT International Young Scientists Global Change Conference CY NOV 16-19, 2003 CL Trieste, ITALY DE remote sensing; vegetation; productivity; ENSO; human population AB Human domination of ecosystems has been pervasive over the last century, with nearly half of Earth's surface transformed by human actions. it is widely accepted that humans appropriate up to 50% of global net primary production (NPP), the energy base of all the trophic levels on the land surface. Yet, despite the important role of vegetation productivity for defining Earth habitability, the covariation of NPP and human population distribution has not been analyzed in depth. We used recently available satellite-based NPP estimates, along with gridded population at 0.5 degrees resolution, first, to identify the global distribution of human population with reference to average NPP and to the various climatic constraints (temperature, water and cloud cover) that limit NPP, second, to analyze recent trends in global NPP in relation to population trends, and third, to identify populations that are vulnerable to changes in NPP due to interannual variability in climate. Our results indicate that over half of the global human population is presently living in areas with above the average NPP of 490 g C m(-2) year(-1). By 1998, nearly 56% of global population lived in regions where water availability strongly influences NPP. Per capita NPP declined over much of Africa between 1982 and 1998, in spite of the estimated increases in NPP over the same period. On average, NPP over 40% of the total vegetated land surface has shown significant correlations with ENSO-induced climate variability affecting over 2.8 billion people. (c) 2004 Elsevier B.V. All rights reserved. C1 Univ Montana, Dept Ecosyst & Conservat Sci, Numer Terradynam Simulat Grp, Missoula, MT 59812 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Tokyo, Grad Sch Agr & Life Sci, Bunkyo Ku, Tokyo 113, Japan. RP Milesi, C (reprint author), Univ Montana, Dept Ecosyst & Conservat Sci, Numer Terradynam Simulat Grp, Missoula, MT 59812 USA. EM milesi@ntsg.umt.edu NR 26 TC 12 Z9 14 U1 2 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 EI 1872-6364 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 2005 VL 47 IS 2-4 BP 221 EP 231 DI 10.1016/j.gloplacha.2004.10.020 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 962SQ UT WOS:000231753100015 ER PT J AU Marchis, F Le Mignant, D Chaffee, FH Davies, AG Kwok, SH Prange, R de Pater, I Amico, P Campbell, R Fusco, T Goodrich, RW Conrad, A AF Marchis, F Le Mignant, D Chaffee, FH Davies, AG Kwok, SH Prange, R de Pater, I Amico, P Campbell, R Fusco, T Goodrich, RW Conrad, A TI Keck AO survey of Io global volcanic activity between 2 and 5 mu m SO ICARUS LA English DT Article DE Io; volcanism; infrared observations ID GALILEO PHOTOPOLARIMETER-RADIOMETER; ADAPTIVE OPTICS OBSERVATIONS; GROUND-BASED OBSERVATIONS; HEAT-FLOW; THERMAL EMISSION; II-TELESCOPE; NIMS DATA; IMAGES; EVOLUTION; PATERA AB We present in this Keck AO paper the first global high angular resolution observations of Io in three broadband near-infrared filters: Kc (2.3 mu m), Lp (3.8 mu m), and Ms (4.7 mu m). The Keck AO observations are composed of 13 data sets taken during short time intervals spanning 10 nights in December, 2001. The MISTRAL deconvolution process, which is specifically aimed for planetary images, was applied to each image. The spatial resolution achieved with those ground-based observations is 150, 240, and 300 km in the Kc, Lp, and Ms band, respectively, making them similar in quality to most of the distant observations of the Galileo/NIMS instrument. Eleven images per filter were selected and stitched together after being deprojected to build a cylindrical map of the entire surface of the satellite. In Kc-band, surface albedc, features, such as paterae (R > 60 km) are easily identifiable. The Babbar region is characterized by extremely low albedo at 2.2 mu m, and shows an absorption band at 0.9 mu m in Galileo/SSI data. These suggest that this region is covered by dark silicate deposits, possibly made of orthopyroxene. In the Lp-Ms (3-5 mu m) bands, the thermal emission from active centers is easily identified. We detected 26 hot spots in both broadband filters over the entire surface of the minor planet; two have never been seen active before, nine more are seen in the Ms band. We focused our study on the hot spots detected in both broadband filters. Using the measurements of their brightness, we derived the temperature and area covered by 100 brightness measurements. Loki displayed a relatively quiescent activity. Dazhbog, a new eruption detected by Galileo/NIMS in August 2001, is a major feature in our survey. We also point out the fading of Tvashtar volcanic activity after more than two years of energetic activity, and the presence of a hot, but small, active center at the location of Surt, possibly a remnant of its exceptional eruption detected in February 2001. Two new active centers, labeled F and V on our data, are detected. Using the best temperature and the surface area derived from the L and M band intensities, we calculated the thermal output of each active center. The most energetic hot spots are Loki and Dazhbog, representing respectively 36 and 19% of the total output calculated from a temperature fit of all hot spots (20.6 x 10(12) W). Based on the temperature derived from hot spots (similar to 400 K), our measurement can unambiguously identify the contribution to the heat flux from the silicate portion of the surface. Because the entire surface was observed, no extrapolation was required to calculate that flux. It is also important to note that we measured the brightness of the individual hot spots when they were located close to the Central Meridian. This minimizes the line-of-sight effect which does not follow strictly a classical cosine law. Finally, we argue that despite the widespread volcanic activity detected, Io was relatively quiescent in December 2001, with a minimum mean total output of 0.4-1.2 W m(-2). This output is at least a factor of two lower than those inferred from observations made at longer wavelengths and at different epochs. (c) 2005 Elsevier Inc. All rights reserved. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. WM Keck Observ, Kamuela, HI 96743 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. Off Natl Etud & Rech Aerosp, DOTA E, F-92322 Chatillon, France. RP Marchis, F (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. EM fmarchis@berkeley.edu RI Marchis, Franck/H-3971-2012 NR 51 TC 45 Z9 45 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 JUL PY 2005 VL 176 IS 1 BP 96 EP 122 DI 10.1016/j.icarus.2004.12.014 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 933TQ UT WOS:000229656200006 ER PT J AU Davies, AG Matson, DL Veeder, GJ Johnson, TV Blaney, DL AF Davies, AG Matson, DL Veeder, GJ Johnson, TV Blaney, DL TI Post-solidification cooling and the age of Io's lava flows SO ICARUS LA English DT Article DE Jupiter; Io; volcanism; lava flow; lava lake; thermal; modeling ID GALILEO NIMS DATA; INFRARED MAPPING SPECTROMETER; JUPITERS MOON IO; SILICATE VOLCANISM; THERMAL EMISSION; PHOTOPOLARIMETER-RADIOMETER; SULFUR FLOW; HEAT-FLOW; TEMPERATURE; ERUPTION AB The modeling of thermal emission from active lava flows must account for the cooling of the lava after solidification. Models of lava cooling applied to data collected by the Galileo spacecraft have, until now, not taken this into consideration. This is a flaw as lava flows on Io are thought to be relatively thin with a range in thickness from similar to 1 to 13 m. Once a flow is completely solidified (a rapid process on a geological time scale), the surface cools faster than the surface of a partially molten flow. Cooling via the base of the lava flow is also important and accelerates the solidification of the flow compared to the rate for the 'semi-infinite' approximation (which is only valid for very deep lava bodies). We introduce a new model which incorporates the solidification and basal cooling features. This model gives a superior reproduction of the cooling of the 1997 Pillan lava flows on Io observed by the Galileo spacecraft. We also use the new model to determine what observations are necessary to constrain lava emplacement style at Loki Patera. Flows exhibit different cooling profiles from that expected from a lava lake. We model cooling with a finite-element code and make quantitative predictions for the behavior of lava flows and other lava bodies that can be tested against observations both on Io and Earth. For example, a 10-m-thick ultramafic flow, like those emplaced at Pillan Patera in 1997, solidifies in similar to 450 days (at which point the surface temperature has cooled to similar to 280 K) and takes another 390 days to cool to 249 K. Observations over a sufficient period of time reveal divergent cooling trends for different lava bodies [examples: lava flows and lava lakes have different cooling trends after the flow has solidified (flows cool faster)]. Thin flows solidify and cool faster than flows of greater thickness. The model can therefore be used as a diagnostic tool for constraining possible emplacement mechanisms and compositions of bodies of lava in remote-sensing data. (c) 2005 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Davies, AG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ashley.davies@jpl.nasa.gov NR 47 TC 17 Z9 17 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 JUL PY 2005 VL 176 IS 1 BP 123 EP 137 DI 10.1016/j.icarus.2005.01.015 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 933TQ UT WOS:000229656200007 ER PT J AU Varadi, F Musotto, S Moore, W Schubert, G AF Varadi, F Musotto, S Moore, W Schubert, G TI Normal modes of synchronous rotation SO ICARUS LA English DT Article DE rotational dynamics; celestial mechanics; satellites general; resonances; moon ID GALILEAN SATELLITES; SOLID BODIES; LIBRATION; MOON; ORIENTATION; PRECESSION; SYSTEM; BODY; LAWS AB The dynamics of synchronous rotation and physical librations are revisited in order to establish a conceptually simple and general theoretical framework applicable to a variety of problems. Our motivation comes from disagreements between the results of numerical simulations and those of previous theoretical studies, and also because different theoretical studies disagree on basic features of the dynamics. We approach the problem by decomposing the orientation matrix of the body into perfectly synchronous rotation:and deviation from the equilibrium state. The normal modes of the linearized equations are computed in the case of a circular satellite orbit, yielding both the periods and the eigenspaces of three librations. Libration in longitude decouples from the other two, vertical modes. There is a fast vertical mode with a period very close to the average rotational period. It corresponds to tilting the body around a horizontal axis while retaining nearly principal-axis rotation. In the inertial frame, this mode appears as nutation and free precession. The other vertical m ode, a slow one, is the free wobble. The effects of the nodal precession of the orbit are investigated from the point of view of Cassim states. We test our theory using numerical simulations of the full equations of the dynamics and discuss the disagreements among our study and previous ones. The numerical simulations also reveal that in the case of eccentric orbits large departures from principal-axis rotation are possible due to a resonance between free precession and wobble. We also revisit the history of the Moon's rotational state and show that it switched from one Cassini state to another when it was at 46.2 Earth radii. This number disagrees with the value 34.2 derived in a previous study. (c) 2005 Elsevier Inc. All rights reserved. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, NASA, Astrobiol Inst, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Padua, Dipartimento Astron, I-35122 Padua, Italy. RP Varadi, F (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. EM varadi@ucla.edu NR 30 TC 2 Z9 2 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 JUL PY 2005 VL 176 IS 1 BP 235 EP 249 DI 10.1016/j.icarus.2005.01.002 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 933TQ UT WOS:000229656200015 ER PT J AU Li, RR Remer, L Kaufman, YJ Mattoo, S Gao, BC Vermote, E AF Li, RR Remer, L Kaufman, YJ Mattoo, S Gao, BC Vermote, E TI Snow and ice mask for the MODIS aerosol products SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS LA English DT Article DE teaerosol; ice; Moderate Resolution Imaging Spectroradiometer (MODIS); snow ID RESOLUTION IMAGING SPECTRORADIOMETER; COVER; CLIMATE; SYSTEM; INDEX; WATER AB Atmospheric products have been derived operationally from multichannel imaging data collected with the Moderate Resolution Imaging Spectroradiometer (MODIS) on-board the Terra and Aqua spacecrafts. Preliminary validations of the products were previously reported. Through analysis of more extensive time-series of MODIS aerosol products (Collection 4), we have found that the aerosol products over land areas are slightly contaminated by snow and ice during the springtime snow-melting season. We have developed an empirical technique using MODIS near-infrared channels centered near 0.86 and 1.24 mu m and a thermal emission channel near 11 mu m to mask out these snow-contaminated pixels over land. Improved aerosol retrievals over land have been obtained. Sample results from application of the technique to MODIS data acquired over North America, northern Europe, and northeastern Asia are presented. The technique has been implemented into the MODIS Collection 5 operational algorithm for retrieving aerosols over land from MODIS data. C1 Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Appl Inc, Greenbelt, MD 20771 USA. USN, Remote Sensing Div, Washington, DC 20375 USA. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. RP Li, RR (reprint author), Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. EM lirongr@climate.gsfc.nasa.gov RI Vermote, Eric/K-3733-2012 NR 22 TC 16 Z9 17 U1 0 U2 12 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 JUL PY 2005 VL 2 IS 3 BP 306 EP 310 DI 10.1109/LGRS.2005.847755 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 949NT UT WOS:000230796100014 ER PT J AU Lin, B Hu, YX AF Lin, B Hu, YX TI Numerical simulations of radar surface air pressure measurements at O-2 bands SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS LA English DT Article DE atmospheric pressure; differential absorption radar; microwave remote sensing ID WATER CLOUD PROPERTIES; ATMOSPHERIC-TEMPERATURE; VISIBLE MEASUREMENTS; SATELLITE MICROWAVE; RADIATION; LIQUID; OCEANS; MODEL; PATH; ICE AB An active microwave method is investigated for measuring surface air pressure by using radar reflections at frequencies around 53-55 GHz O-2 bands. The numerical simulation results for homogeneous backgrounds show that with an airborne radar working at these O-2 absorption bands, the rms errors of the radar surface pressure estimations with 15-dB signal-to-noise ratio can be as low as 4-7 mb. A radar system that covers these wavelengths will have great potentials for weather observations and other meteorological applications. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM bing.lin-1@nasa.gov; yongxiang.hu-1@nasa.gov RI Hu, Yongxiang/K-4426-2012 NR 21 TC 9 Z9 9 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1545-598X EI 1558-0571 J9 IEEE GEOSCI REMOTE S JI IEEE Geosci. Remote Sens. Lett. PD JUL PY 2005 VL 2 IS 3 BP 324 EP 328 DI 10.1109/LGRS.2005.848515 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 949NT UT WOS:000230796100018 ER PT J AU Adams, ML Loncar, M Scherer, A Qiu, YM AF Adams, ML Loncar, M Scherer, A Qiu, YM TI Microfluidic integration of porous photonic crystal nanolasers for chemical sensing SO IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS LA English DT Article DE microfluidics; optical cavity; photonic crystal; polydimethylsiloxane (PDMS) ID DEFECT MODES; QUANTUM-DOT; LASER; CAVITIES; SLAB AB We have recently developed planar photonic crystal nanolasers based on porous cavity designs. High-quality factor cavities confine light within the pores of the photonic crystal and, thus, our lasers are ideally suited for the investigation of nanoscale interactions between light and matter. We have demonstrated the operation of photonic crystal lasers within different chemical solutions, embedded them into silicone microfluidic flow channels, and were able to detect refractive index changes as small as An = 0.005. We predict that our porous nanolasers can detect refractive index changes as small as Delta n = 8.23 center dot 10(-4). C1 ENSCO Inc, Melbourne, FL 32940 USA. Harvard Univ, Gordon Mckay Lab, Div Engn & Appl Sci, Cambridge, MA 02138 USA. CALTECH, Dept Elect Engn Appl Phys & Phys, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, In Situ Technol & Expt Syst Sect, Pasadena, CA 91109 USA. RP Adams, ML (reprint author), ENSCO Inc, Melbourne, FL 32940 USA. EM adams.mark@ensco.com; loncar@deas.harvard.edu; etcher@caltech.edu; yqiu@jpl.nasa.gov NR 20 TC 34 Z9 34 U1 1 U2 11 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0733-8716 J9 IEEE J SEL AREA COMM JI IEEE J. Sel. Areas Commun. PD JUL PY 2005 VL 23 IS 7 BP 1348 EP 1354 DI 10.1109/JSAC.2005.0851192 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 941RP UT WOS:000230232200008 ER PT J AU Donzelli, P Zelkowitz, M Basili, V Allard, D Meyer, KN AF Donzelli, P Zelkowitz, M Basili, V Allard, D Meyer, KN TI Evaluating COTS component dependability in context SO IEEE SOFTWARE LA English DT Article ID SOFTWARE; MODEL AB Selecting the right component to integrate into an application is challenging and risky, particularly without empirical evidence that a component will be dependable in a particular context. This empirical COTS evaluation method reduces selection risks by focusing on a specific target context. It also supports integration by highlighting the component weaknesses that must be addressed to achieve success. C1 Univ Maryland, Dept Comp Sci, College Pk, MD 20742 USA. Univ Maryland, Inst Adv Comp Studies, College Pk, MD 20742 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. RP Univ Maryland, Dept Comp Sci, College Pk, MD 20742 USA. EM donzelli@cs.umd.edu; marv@zelkowitz.com; basili@cs.umd.edu; dan@jpl.nasa.gov; kenneth.n.meyer@jpl.nasa.gov NR 12 TC 4 Z9 4 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0740-7459 EI 1937-4194 J9 IEEE SOFTWARE JI IEEE Softw. PD JUL-AUG PY 2005 VL 22 IS 4 BP 46 EP + DI 10.1109/MS.2005.91 PG 9 WC Computer Science, Software Engineering SC Computer Science GA 939DX UT WOS:000230053700009 ER PT J AU Wang, PKC Yee, J Xia, CY Mokuno, M Hadaegh, FY AF Wang, PKC Yee, J Xia, CY Mokuno, M Hadaegh, FY TI Cooperative control of a magnetically levitated interferometer: Experimental study SO IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY LA English DT Article DE cooperative control; disturbance isolation; multiple spacecraft control; space interferometer ID SPACECRAFT AB An experimental study is made on the effectiveness of simple cooperative controls for the optical elements of a laboratory interferometer in interference fringe acquisition. The laboratory setup simulates a space interferometer formed by three spacecraft in a triangular formation. Each interferometer element (two collectors and one combiner) is magnetically levitated and free to rotate about a fixed vertical axis. Feedback-controlled disturbance isolation systems are introduced to isolate the optical elements from the collector and combiner motions induced by external disturbances. Fine optical alignment is achieved by cooperative controls for the collectors driven by sensor data communicated between the collector and combiner via onboard radio transceivers. The main accomplishment of this study is the demonstration that quasi-stationary interference fringes can be captured using our magnetically levitated interferometer with simple cooperative optical-alignment controls. The capture time duration is on the order of half a second. C1 Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA. Japan Aerosp Explorat Agcy, Tsukuba, Ibaraki 3058505, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wang, PKC (reprint author), Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA. EM pkcwang@ee.ucla.edu; mokuno.masaaki@jaxa.jp; Fred.Y.Hadaegh@jpl.nasa.gov NR 14 TC 0 Z9 0 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1063-6536 J9 IEEE T CONTR SYST T JI IEEE Trans. Control Syst. Technol. PD JUL PY 2005 VL 13 IS 4 BP 654 EP 662 DI 10.1109/TCST.2005.846853 PG 9 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA 936ON UT WOS:000229865400018 ER PT J AU Kenny, BH Kascak, PE Jansen, R Dever, T Santiago, W AF Kenny, BH Kascak, PE Jansen, R Dever, T Santiago, W TI Control of a high-speed flywheel system for energy storage in space applications SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT IEEE International Electronic Machines and Drives Conference CY JUN 01-04, 2003 CL MADISON, WI SP IEEE Ind Applicat Soc, IEEE Ind Elect Soc, IEEE Power Elect Soc, IEEE Power Engn Soc DE charge and discharge control; flywheel energy storage; high-speed permanent-magnet machine; space power ID VELOCITY ESTIMATION; DRIVES AB A novel control algorithm for the charge and discharge modes of operation of a flywheel energy storage system for space applications is presented. The motor control portion of the algorithm uses sensorless field oriented control with position and speed estimates determined from a signal injection technique at low speeds and a back electromotive force technique at higher speeds. The charge and discharge portion of the algorithm use command feedforward and disturbance decoupling, respectively, to achieve fast response with low gains. Simulation and experimental results are presented demonstrating the successful operation of the flywheel control up to the rated speed of 60000 r/min. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Kenny, BH (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM Barbara.Kenny@grc.nasa.gov; Peter.E.Kascak@grc.nasa.gov; Ralph.H.Jansen@grc.nasa.gov; Timothy.P.Dever@grc.nasa.gov; walter.santiago-1@nasa.gov NR 11 TC 29 Z9 34 U1 1 U2 13 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD JUL-AUG PY 2005 VL 41 IS 4 BP 1029 EP 1038 DI 10.1109/TIA.2005.851021 PG 10 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA 946KV UT WOS:000230572000018 ER PT J AU Kanduri, AK Thomas, G Cabrol, N Grin, E Anderson, RC AF Kanduri, AK Thomas, G Cabrol, N Grin, E Anderson, RC TI The (In)accuracy of novice rover operators' perception of obstacle height from monoscopic images SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART A-SYSTEMS AND HUMANS LA English DT Article DE computer interface human factors; mobile robot motion planning; mobile robots; spatial reasoning AB Researchers have previously described a mobile robot, or rover, operator's difficulty in accurately perceiving the rover's tilt and roll, which can lead to rollover accidents. Safe mobile robot navigation and effective mission planning also require an operator to accurately interpret and understand the geometry and scale of features in the rover's environment. This work presents an experiment that measures an observer's ability to estimate height of distant (5-15 m) obstacles given an accurate local model (e.g., within 0-5 in of the rover), a panoramic image, and a physical mock-up of the local terrain. The experimental conditions were intended to represent a best-case scenario for a stopped rover equipped with short base-line stereoscopic cameras. The participants' task was to extrapolate the well-modeled local geometry to monoscopic images of the more distant terrain. The experiment compared two estimation techniques. With the first technique, each observer physically indicated his or her direct estimates of the obstacle distance and height. With the second estimation technique, which we call horizon analysis, the observer indicated the position of the top and bottom of each rock on an image and the height was calculated by measuring the visual angle between the theoretical horizon and the points indicated by the observer. The direct estimation technique overestimated the height of the rocks by an average of 190%; the horizon analysis technique overestimated by 80%. The results suggest that even when provided with a rich set of supplementary and context information, rover operators have significant difficulty in vertically perceiving the scale of distant terrain. The results also suggest that horizon analysis is a more accurate method for determining the height of distant rover navigation obstacles, when the local terrain is nearly level. C1 NASA, Dept Mech & Ind Engn, Iowa City, IA 52242 USA. NASA, Ames Res Facil, Div Space Sci, Moffett Field, CA 94035 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kanduri, AK (reprint author), NASA, Dept Mech & Ind Engn, Iowa City, IA 52242 USA. EM Geb-Thomas@uiowa.edu; ncabrol@mail.arc.nasa.gov; egrin@mail.arc.nasa.gov; Robert.C.Anderson@jpl.nasa.gov NR 0 TC 3 Z9 3 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1083-4427 J9 IEEE T SYST MAN CY A JI IEEE Trans. Syst. Man Cybern. Paart A-Syst. Hum. PD JUL PY 2005 VL 35 IS 4 BP 505 EP 512 DI 10.1109/TSMCA.2005.850601 PG 8 WC Computer Science, Cybernetics; Computer Science, Theory & Methods SC Computer Science GA 936OO UT WOS:000229865500008 ER PT J AU Chang, SC Wu, YH Yang, V Wang, XY AF Chang, SC Wu, YH Yang, V Wang, XY TI Local time-stepping procedures for the space-time conservation element and solution element method SO INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS LA English DT Article DE space-time CESE method; local time-stepping procedure; flux conservation; grid interface ID ADAPTIVE MESH REFINEMENT; EULER EQUATIONS; LAWS AB A local time-stepping procedure for the space-time conservation element and solution element (CESE) method has been developed. This new procedure allows for variation of time-step size in both space and time, and can also be extended to become multi-dimensional solvers with structured/unstructured spatial grids. Moreover, it differs substantially in concept and methodology from the existing approaches. By taking full advantage of key concepts of the CESE method, in a simple and efficient manner it can enforce flux conservation across an interface separating grid zones of different time-step sizes. In particular, no correction pass is needed. Numerical experiments show that, for a variety of flow problems involving moving shock and flame discontinuities, accurate and robust numerical simulations can be achieved even with a reduction in time-step size on the order of 10 or higher for grids across a single interface. C1 Penn State Univ, University Pk, PA 16802 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Yang, V (reprint author), Penn State Univ, University Pk, PA 16802 USA. EM vigor@psu.edu NR 19 TC 5 Z9 5 U1 1 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1061-8562 J9 INT J COMPUT FLUID D JI Int. J. Comput. Fluid Dyn. PD JUL PY 2005 VL 19 IS 5 BP 359 EP 380 DI 10.1080/10618560500092610 PG 22 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 999JA UT WOS:000234384400001 ER PT J AU Zhang, H Mudawar, I Hasan, MM AF Zhang, H Mudawar, I Hasan, MM TI Flow boiling CHF in microgravity SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID CRITICAL HEAT-FLUX; BODY FORCE; WALL; MECHANISM; LONG AB Poor understanding of flow boiling in microgravity has recently emerged as,a key obstacle to the development of many types of power generation and life support systems intended for space exploration. This study examines flow boiling CHF in microgravity that was achieved in parabolic flight experiments with FC-72 onboard NASA's KC-135 turbojet. At high heat fluxes, bubbles quickly coalesced into fairly large vapor patches along the heated wall. As CHF was approached, these patches grew in length and formed a wavy vapor layer that propagated along the wall, permitting liquid access only in the wave troughs. CHF was triggered by separation of the liquid-vapor interface from the wall due to intense vapor effusion in the troughs. This behavior is consistent with, and accurately predicted by the Interfacial Lift-off CHF Model. It is shown that at low velocities CHF in microgravity is significantly smaller than in horizontal flow on earth. CHF differences between the two environments decreased with increasing velocity, culminating in virtual convergence at about 1.5 m/s. This proves it is possible to design inertia-dominated systems by maintaining flow velocities above the convergence limit. Such systems allow data, correlations, and/or models developed on earth to be safely implemented in space systems. (c) 2005 Elsevier Ltd. All rights reserved. C1 Purdue Univ, 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, Boiling & Two Phase Flow Lab, 1288 Mech Engn Bldg, W Lafayette, IN 47907 USA. EM mudawar@ecn.purdue.edu NR 19 TC 45 Z9 46 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 JUL PY 2005 VL 48 IS 15 BP 3107 EP 3118 DI 10.1016/j.ijheatmasstransfer.2005.02.015 PG 12 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 937JR UT WOS:000229920900007 ER PT J AU Arbocz, J Starnes, JH AF Arbocz, J Starnes, JH TI Hierarchical high-fidelity analysis methodology for buckling critical structures SO JOURNAL OF AEROSPACE ENGINEERING LA English DT Article DE buckling; thin shell structures; aerospace engineering; loads ID CYLINDRICAL-SHELLS; ELASTIC STABILITY; COMPRESSION; CYLINDERS AB A hierarchical high-fidelity analysis methodology for predicting the critical buckling load of compression-loaded thin-walled isotropic shells is described. This hierarchical procedure includes three levels of fidelity for the analysis. Level I assumes that the buckling load can be predicted by the classical shell solution with simply supported boundary condition, and with a linear membrane prebuckling solution. Level 2 includes the effects of a nonlinear prebuckling solution and the effects of traditional clamped or simply supported boundary conditions. Level 3 includes the nonlinear interaction between nearly simultaneous buckling modes and the effects of boundary imperfections and general boundary conditions. Various deterministic and probabilistic approaches are used to account for the degrading effects of unavoidable shell-wall geometric imperfections. The results from the three solution levels are compared with experimental results, and the effects of the assumptions and approximations used for the three solution levels are discussed. This hierarchical analysis approach can be used in the design process to converge rapidly to an accurate prediction of the expected buckling load of a thin-shell design problem. C1 Delft Univ Technol, Fac Aerosp Engn, Delft, Netherlands. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Arbocz, J (reprint author), Delft Univ Technol, Fac Aerosp Engn, Delft, Netherlands. NR 38 TC 3 Z9 3 U1 0 U2 2 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 JUL PY 2005 VL 18 IS 3 BP 168 EP 178 DI 10.1061/(ASCE)0893-1321(2005)18:3(168) PG 11 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA 940DN UT WOS:000230124000005 ER PT J AU Mavriplis, DJ Levy, DW AF Mavriplis, DJ Levy, DW TI Transonic drag prediction using an unstructured multigrid solver SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA 40th Aerospace Sciences Meeting CY JAN 14-18, 2002 CL RENO, NV SP Amer Inst Aeronaut & Astronaut ID EULER EQUATIONS; MESHES; AGGLOMERATION; FLOWS; GRIDS AB This paper summarizes the results obtained with the NSU3D unstructured multigrid solver for the First AIAA Drag Prediction Workshop held in Anaheim, California, in June 2001. The test case for the workshop consists of a wing-body configuration at transonic flow conditions. Flow analyses for a complete test matrix of lift coefficient values and Mach numbers at a constant Reynolds number are performed, thus producing a set of drag polars; and drag rise curves, which are compared with experimental data. Results were obtained independently by both authors using an identical baseline grid and different refined grids. Most cases were run in parallel on commodity cluster-type machines, whereas the largest cases were run on an SGI Origin machine using 128 processors. The objective of this paper is to study the accuracy of the subject unstructured grid solver for predicting drag in the transonic cruise regime, to assess the efficiency of the method in terms of convergence, CPU time, and memory, and to determine the effects of grid resolution on this predictive ability and its computational efficiency. A good predictive ability is demonstrated over a wide range of conditions, although accuracy was found to degrade for cases at higher Mach numbers and lift values where increasing amounts of How separation occur. The ability to rapidly compute large numbers of cases at varying flow conditions using an unstructured solver on inexpensive clusters of commodity computers is also demonstrated. C1 Univ Wyoming, Dept Mech Engn, Laramie, WY 82071 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Cessna Aircraft Co, Wichita, KS 67218 USA. RP Mavriplis, DJ (reprint author), Univ Wyoming, Dept Mech Engn, Laramie, WY 82071 USA. NR 17 TC 6 Z9 6 U1 0 U2 0 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 JUL-AUG PY 2005 VL 42 IS 4 BP 887 EP 893 DI 10.2514/1.8233 PG 7 WC Engineering, Aerospace SC Engineering GA 954EB UT WOS:000231135800009 ER PT J AU Durston, DA Walker, SM Driver, DM Smith, SC Savas, O AF Durston, DA Walker, SM Driver, DM Smith, SC Savas, O TI Wake-vortex alleviation flowfield studies SO JOURNAL OF AIRCRAFT 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 INSTABILITY AB Wake-vortex-alleviation research was conducted in the far-field vortex wake of a generic wing-tail aircraft model. The goals were to achieve accelerated vortex strength reduction and to map the conditions at which this reduction would occur. The wing-tail model was run in a water tow tank to generate a pair of unequal-strength counter-rotating vortices on each side of centerline. Dye flow visualization provided physical insight into the nature of the vortex interactions, and three-component particle image velocimetry allowed quantification of key characteristics of the flowfield, including circulation, vorticity, vortex trajectory, and induced rolling moments. Experiments were conducted for a variety of model angles of attack, tail incidence angles, and tail spans. The results showed that with high tail/wing circulation ratios (high tail downloads) the tail and wing vortices interacted strongly, leaving substantially weakened vortices after a distance of about 60 to 70 spans downstream of the model. A longitudinal static stability analysis identified the moderate-to-high static margins required to achieve such circulation ratios. C1 NASA, Ames Res Ctr, Aerophys Branch, Moffett Field, CA 94035 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Durston, DA (reprint author), NASA, Ames Res Ctr, Aerophys Branch, Moffett Field, CA 94035 USA. EM Don.Durston@nasa.gov; Stephen.M.Walker@nasa.gov; David.M.Driver@nasa.gov; Stephen.C.Smith@nasa.gov; savas@newton.berkeley.edu RI Smith, Sean/H-5003-2015 OI Smith, Sean/0000-0002-5679-8205 NR 19 TC 14 Z9 14 U1 1 U2 3 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 JUL-AUG PY 2005 VL 42 IS 4 BP 894 EP 907 DI 10.2514/1.7904 PG 14 WC Engineering, Aerospace SC Engineering GA 954EB UT WOS:000231135800010 ER PT J AU Garcia, JA AF Garcia, JA TI Numerical investigation of nonlinear aeroelastic effects on flexible high-aspect-ratio wings SO JOURNAL OF AIRCRAFT LA English DT Article ID AIRCRAFT AB A nonlinear aeroelastic analysis is developed to analyze the aeroelastic characteristics of flexible high-aspect-ratio wings at transonic speeds. This is achieved by directly coupling a three-dimensional geometric nonlinear methodology, based on a 12 degree-of-freedom beam finite element, with an Euler/Navier-Stokes computational fluid dynamics analysis. Static aeroelastic results are presented for an unswept and swept high-aspect-ratio wing. Unswept wing results show a reversal in twist due to the nonlinear torsion-bending coupling effects. Specifically, the torsional moments due to drag become large enough to cause the wing twist rotations to washin the wing tips, whereas the linear results show a washout twist rotation. The nonlinear twist results are attributed to the large bending displacements coupled with the large drag experienced by this flexible high-aspect-ratio wing at the transonic flow conditions. Swept wing results show that nonlinear torsion-bending effects tend to reduce the amount of washout as compared to a linear structural aeroelastic analysis, making the wing more prone to tip stall. C1 NASA, Ames Res Ctr, Syst Anal Branch, Moffett Field, CA 94035 USA. RP Garcia, JA (reprint author), NASA, Ames Res Ctr, Syst Anal Branch, Mail Stop 258-1, Moffett Field, CA 94035 USA. NR 35 TC 16 Z9 19 U1 1 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 JUL-AUG PY 2005 VL 42 IS 4 BP 1025 EP 1036 DI 10.2514/1.6544 PG 12 WC Engineering, Aerospace SC Engineering GA 954EB UT WOS:000231135800024 ER PT J AU Ambur, DR Rouse, M AF Ambur, DR Rouse, M TI Design and evaluation of composite fuselage panels subjected to combined loading conditions SO JOURNAL OF AIRCRAFT LA English DT Article AB Methodologies used in industry for designing transport aircraft composite fuselage structures are discussed. Several aspects of the design methodologies are based on assumptions from metallic fuselage technology, which requires that full-scale structures be tested with the actual loading conditions to validate the designs. Composite panels that represent crown and side regions of a fuselage structure are designed by the use of this approach and tested in biaxial tension. Descriptions of the state-of-the-art test facilities used for this structural evaluation are presented. These facilities include a pressure-box test machine and a D-box test fixture in a combined loads test machine, which are part of a combined loads test system. Nonlinear analysis results for a reference shell and a stiffened composite panel tested in the pressure-box test machine with and without damage are presented. The analytical and test results are compared to assess the ability of the pressure-box test machine to simulate a shell stress state with and without damage. A combined loads test machine for testing aircraft primary structures is described. This test machine includes a D-box test fixture to accommodate curved stiffened panels, and the design features of this test fixture are presented. Finite element analysis results for a curved panel to be tested in the D-box test fixture are also discussed. C1 NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. RP Ambur, DR (reprint author), NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. NR 6 TC 5 Z9 5 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 JUL-AUG PY 2005 VL 42 IS 4 BP 1037 EP 1045 DI 10.2514/1.18994 PG 9 WC Engineering, Aerospace SC Engineering GA 954EB UT WOS:000231135800025 ER PT J AU Li, W Krist, S AF Li, W Krist, S TI Spline-based airfoil curvature smoothing and its applications SO JOURNAL OF AIRCRAFT LA English DT Article ID LOCAL PROCEDURES; INTERPOLATION; CURVE AB The performance of a transonic airfoil is directly related to the airfoil curvature profile and its smoothness. Whereas univariate data smoothing has been studied extensively, very little research has been conducted on curvature smoothing. Consequently, airfoil smoothing in design environments is largely based on heuristic methods, and there is an art to the generation of an unbiased smooth fit of the airfoil's curvature profile by the modification of its geometry. In this paper, the sum of squares of the third derivative jumps is used as a curvature smoothness measure for the development of a spline-based airfoil smoothing method, called constrained fitting for airfoil curvature smoothing (CFACS). CFACS can take out dramatic curvature oscillations with extremely small geometry changes and smooth an airfoil segment without creating curvature oscillations near the endpoints. Visually, CFACS. generates an unbiased smooth fit of the curvature profile. Examples demonstrating the utility of CFACS show how the smoothing can be tailored to promote desirable characteristics in performance trade studies. C1 NASA, Langley Res Ctr, Multidisciplinary Optimizat Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Configurat Aerodynam Branch, Hampton, VA 23681 USA. RP Li, W (reprint author), NASA, Langley Res Ctr, Multidisciplinary Optimizat Branch, Hampton, VA 23681 USA. EM w.li@nasa.gov; e.krist@nasa.gov NR 22 TC 5 Z9 5 U1 0 U2 2 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 JUL-AUG PY 2005 VL 42 IS 4 BP 1065 EP 1074 DI 10.2514/1.10394 PG 10 WC Engineering, Aerospace SC Engineering GA 954EB UT WOS:000231135800028 ER PT J AU Windhorst, R Ardema, M AF Windhorst, R Ardema, M TI Some characteristics of supersonic transport trajectories SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA Guidance, Navigation and Control Conference CY AUG 14-17, 2000 CL DENVER, CO SP Amer Inst Aeronaut & Astronaut ID EXPANSIONS C1 NASA, Ames Res Ctr, Aerosp Operat Modeling Branch, Moffett Field, CA 94035 USA. Santa Clara Univ, Dept Mech Engn, Santa Clara, CA 95053 USA. RP Windhorst, R (reprint author), NASA, Ames Res Ctr, Aerosp Operat Modeling Branch, Moffett Field, CA 94035 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JUL-AUG PY 2005 VL 42 IS 4 BP 1079 EP 1081 DI 10.2514/1.11940 PG 3 WC Engineering, Aerospace SC Engineering GA 954EB UT WOS:000231135800030 ER PT J AU Bernstein, BC McDonough, F Politovich, MK Brown, BG Ratvasky, TP Miller, DR Wolff, CA Cunning, G AF Bernstein, BC McDonough, F Politovich, MK Brown, BG Ratvasky, TP Miller, DR Wolff, CA Cunning, G TI Current icing potential: Algorithm description and comparison with aircraft observations SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SUPERCOOLED LIQUID WATER; MICROSCALE STRUCTURE; WINTER STORMS; PART I; FORECASTS; CLOUDS; MESOSCALE; DRIZZLE; ENVIRONMENTS; VERIFICATION AB The "current icing potential" (CIP) algorithm combines satellite, radar, surface, lightning, and pilot-report observations with model output to create a detailed three-dimensional hourly diagnosis of the potential for the existence of icing and supercooled large droplets. It uses a physically based situational approach that is derived from basic and applied cloud physics, combined with forecaster and onboard flight experience from field programs. Both fuzzy logic and decision-tree logic are applied in this context. CIP determines the locations of clouds and precipitation and then estimates the potential for the presence of supercooled liquid water and supercooled large droplets within a given airspace. First developed in the winter of 1997/98, CIP became an operational National Weather Service and Federal Aviation Administration product in 2002, providing real-time diagnoses that allow users to make route-specific decisions to avoid potentially hazardous icing. The CIP algorithm, its individual components, and the logic behind them are described. C1 Natl Ctr Atmospher Res, Res Appl Program, Boulder, CO 80307 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Bernstein, BC (reprint author), Natl Ctr Atmospher Res, Res Appl Program, POB 3000, Boulder, CO 80307 USA. EM bernstei@rap.ucar.edu NR 50 TC 27 Z9 28 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JUL PY 2005 VL 44 IS 7 BP 969 EP 986 DI 10.1175/JAM2246.1 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 955JA UT WOS:000231221000001 ER PT J AU Andre, CL Wilt, DM Pitera, AJ Lee, ML Fitzgerald, EA Ringel, SA AF Andre, CL Wilt, DM Pitera, AJ Lee, ML Fitzgerald, EA Ringel, SA TI Impact of dislocation densities on n(+)/p and p(+)/n junction GaAs diodes and solar cells on SiGe virtual substrates SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; P-N-JUNCTIONS; THREADING DISLOCATIONS; BUFFER LAYERS; GENERATION; MOBILITY; QUALITY; INP AB Recent experimental measurements have shown that in GaAs with elevated threading dislocation densities (TDDs) the electron lifetime is much lower than the hole lifetime [C. L. Andre, J. J. Boeckl, D. M. Wilt, A. J. Pitera, M. L. Lee, E. A. Fitzgerald, B. M. Keyes, and S. A. Ringel, Appl. Phys. Lett. 84, 3884 (2004)]. This lower electron lifetime suggests an increase in depletion region recombination and thus in the reverse saturation current (J(0) for an n(+)/p diode compared with a p(+)/n diode at a given TDD. To confirm this, GaAs diodes of both polarities were grown on compositionally graded Ge/Si1-xGex/Si (SiGe) substrates with a TDD of 1 X 10(6) cm(-2). It is shown that the ratio of measured J(0) values is consistent with the inverse ratio of the expected lifetimes. Using a TDD-dependent lifetime in solar cell current-voltage models we found that the V-oc, for a given short-circuit current, also exhibits a poorer TDD tolerance for GaAs n(+)/p solar cells compared with GaAs p(+)/n solar cells. Experimentally, the open-circuit voltage (V-oc) for the n(+)/p GaAs solar cell grown on a SiGe substrate with a TDD of similar to 1 X 10(6) cm(-2) was similar to 880 mV which was significantly lower than the similar to 980 mV measured for a p(+)/n GaAs solar cell grown on SiGe at the same TDD and was consistent with the solar cell modeling results reported in this paper. We conclude that p(+)/n polarity GaAs junctions demonstrate superior dislocation tolerance than n(+)/p configured GaAs junctions, which is important for optimization of lattice-mismatched Ill-V devices. (c) 2005 American Institute of Physics. C1 Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. NASA, Glenn Res Ctr, Photovolta & Space Environm Branch, Cleveland, OH 44135 USA. MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. RP Ringel, SA (reprint author), 205 Dresse Lab, 2015 Neil Ave, Columbus, OH 43210 USA. EM ringel.5@osu.edu RI Lee, Minjoo/A-9720-2008 OI Lee, Minjoo/0000-0002-3151-3808 NR 33 TC 38 Z9 39 U1 0 U2 20 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 2005 VL 98 IS 1 AR 014502 DI 10.1063/1.1946194 PG 5 WC Physics, Applied SC Physics GA 953FO UT WOS:000231062200107 ER PT J AU Wade, CE Stanford, KI Stein, TP Greenleaf, JE AF Wade, CE Stanford, KI Stein, TP Greenleaf, JE TI Intensive exercise training suppresses testosterone during bed rest SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE countermeasures; steroidogenesis; cortisol; progesterone; catecholamines ID VOLUME REGULATING HORMONES; SIMULATED WEIGHTLESSNESS; ENDOCRINE RESPONSES; RENAL-FUNCTION; SPACE-FLIGHT; SPACEFLIGHT; METABOLISM; RUNNERS; HUMANS; ENERGY AB Spaceflight and prolonged bed rest ( BR) alter plasma hormone levels inconsistently. This may be due, in part, to prescription of heavy exercise as a countermeasure for ameliorating the adverse effects of disuse. The initial project was to assess exercise programs to maintain aerobic performance and leg strength during BR. The present study evaluates the effect of BR and the performance of the prescribed exercise countermeasures on plasma steroid levels. In a 30-day BR study of male subjects, the efficacy of isotonic (ITE, n = 7) or isokinetic exercise (IKE, n = 7) training was evaluated in contrast to no exercise ( n = 5). These exercise countermeasures protected aerobic performance and leg strength successfully. BR alone (no-exercise group) did not change steroidogenesis, as assessed by the plasma concentrations of cortisol, progesterone, aldosterone, and free ( FT) and total testosterone ( TT). In the exercise groups, both FT and TT were decreased ( P < 0.05): FT during IKE from 24 +/- 1.7 to 18 +/- 2.0 pg/ml and during ITE from 21 +/- 1.5 to 18 +/- 1 pg/ml, and TT during IKE from 748 +/- 68 to 534 +/- 46 ng/dl and during ITE from 565 +/- 36 to 496 +/- 38 ng/dl. The effect of intensive exercise countermeasures on plasma testosterone was not associated with indexes of overtraining. The reduction in plasma testosterone associated with both the IKE and ITE countermeasures during BR supports our hypothesis that intensive exercise countermeasures may, in part, contribute to changes in plasma steroid concentrations during spaceflight. C1 USA, Inst Surg Res, Ft Sam Houston, TX 78234 USA. NASA, Div Life Sci, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Med & Dent New Jersey, Sch Osteopath Med, Stratford, NJ 08084 USA. RP Wade, CE (reprint author), USA, Inst Surg Res, 3400 Rawley E Chambers Ave, Ft Sam Houston, TX 78234 USA. EM charles.wade@amedd.army.mil NR 40 TC 10 Z9 12 U1 1 U2 3 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD JUL PY 2005 VL 99 IS 1 BP 59 EP 63 DI 10.1152/japplphysiol.00332.2004 PG 5 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 943WM UT WOS:000230385800009 PM 15705732 ER PT J AU Zwart, SR Davis-Street, JE Paddon-Jones, D Ferrando, AA Wolfe, RR Smith, SM AF Zwart, SR Davis-Street, JE Paddon-Jones, D Ferrando, AA Wolfe, RR Smith, SM TI Amino acid supplementation alters bone metabolism during simulated weightlessness SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE bone resorption; methionine; n-telopeptide; acidosis; bed rest ID DIETARY-PROTEIN; BED REST; POSTMENOPAUSAL WOMEN; CALCIUM-ABSORPTION; URINARY CALCIUM; MINERAL DENSITY; HIP FRACTURE; SPACE-FLIGHT; FRAMINGHAM OSTEOPOROSIS; ELDERLY-WOMEN AB High-protein and acidogenic diets induce hypercalciuria. Foods or supplements with excess sulfur-containing amino acids increase endogenous sulfuric acid production and therefore have the potential to increase calcium excretion and alter bone metabolism. In this study, effects of an amino acid/carbohydrate supplement on bone resorption were examined during bed rest. Thirteen subjects were divided at random into two groups: a control group ( Con, n = 6) and an amino acid-supplemented group ( AA, n = 7) who consumed an extra 49.5 g essential amino acids and 90 g carbohydrate per day for 28 days. Urine was collected for n-telopeptide (NTX), deoxypyridinoline (DPD), calcium, and pH determinations. Bone mineral content was determined and potential renal acid load was calculated. Bone-specific alkaline phosphatase was measured in serum samples collected on day 1 ( immediately before bed rest) and on day 28. Potential renal acid load was higher in the AA group than in the Con group during bed rest ( P < 0.05). For all subjects, during bed rest urinary NTX and DPD concentrations were greater than pre-bed rest levels ( P < 0.05). Urinary NTX and DPD tended to be higher in the AA group ( P = 0.073 and P = 0.056, respectively). During bed rest, urinary calcium was greater than baseline levels ( P < 0.05) in the AA group but not the Con group. Total bone mineral content was lower after bed rest than before bed rest in the AA group but not the Con group ( P < 0.05). During bed rest, urinary pH decreased ( P < 0.05), and it was lower in the AA group than the Con group. These data suggest that bone resorption increased, without changes in bone formation, in the AA group. C1 NASA, Nutr Biochem Lab, Human Adaptat & Countermeasures Off, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Enterprise Advisory Serv Inc, Houston, TX USA. Univ Texas, Med Branch, Dept Surg, Galveston, TX 77550 USA. Univ Texas, Med Branch, Dept Anesthesiol, Galveston, TX 77550 USA. RP Smith, SM (reprint author), NASA, Nutr Biochem Lab, Human Adaptat & Countermeasures Off, Lyndon B Johnson Space Ctr, Mail Code SK3, Houston, TX 77058 USA. EM scott.m.smith@nasa.gov RI Ferrando, Adolfo /Q-7026-2016 FU NIA NIH HHS [P30 AG024832] NR 55 TC 30 Z9 31 U1 0 U2 5 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD JUL PY 2005 VL 99 IS 1 BP 134 EP 140 DI 10.1152/japplphysiol.01406.2004 PG 7 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 943WM UT WOS:000230385800020 PM 15691900 ER PT J AU Sun, J Burns, SP Vandemark, D Donelan, MA Mahrt, L Crawford, TL Herbers, THC Crescenti, GH French, JR AF Sun, J Burns, SP Vandemark, D Donelan, MA Mahrt, L Crawford, TL Herbers, THC Crescenti, GH French, JR TI Measurement of directional wave spectra using aircraft laser altimeters SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SYNTHETIC-APERTURE RADAR; OCEAN SURFACE-WAVES; AIRBORNE MEASUREMENTS; NUMBER SPECTRA; CARBON-DIOXIDE; PART II; FLUX; TURBULENCE; FIELDS; PITCH AB A remote sensing method to measure directional oceanic surface waves by three laser altimeters on the NOAA LongEZ aircraft is investigated. To examine feasibility and sensitivity of the wavelet analysis method to various waves, aircraft motions, and aircraft flight directions relative to wave propagation directions, idealized surface waves are simulated from various idealized aircraft flights. In addition, the wavelet analysis method is also applied to two cases from field measurements, and the results are compared with traditional wave spectra from buoys. Since the wavelet analysis method relies on the "wave slopes" measured through phase differences between the time series of the laser distances between the aircraft and sea surface at spatially separated locations, the resolved directional wavenumber and wave propagation direction are not affected by aircraft motions if the resolved frequencies of the aircraft motion and the wave are not the same. However, the encounter wave frequency, which is directly resolved using the laser measurement from the moving aircraft, is affected by the Doppler shift due to aircraft motion relative to wave propagations. The wavelet analysis method could fail if the aircraft flies in the direction such that the aircraft speed along the wave propagation direction is the same as the wave phase speed (i.e., the aircraft flies along wave crests or troughs) or if two waves with different wavelengths and phase speed have the same encountered wavelength from the aircraft. In addition, the data noise due to laser measurement uncertainty or natural isotropic surface elevation perturbations can also affect the relative phase difference between the laser distance measurements, which in turn affects the accuracy of the resolved wavenumber and wave propagation direction. The smallest waves measured by the lasers depend on laser sampling rate and horizontal distances between the lasers (for the LongEZ this is 2 m). The resolved wave direction and wavenumber at the peak wave from the two field experiments compared well with on-site buoy observations. Overall, the study demonstrates that three spatially separated laser altimeters on moving platforms can be utilized to resolve two-dimensional wave spectra. C1 Natl Ctr Atmospher Res, MMM, Boulder, CO 80307 USA. NASA, Goddard Space Flight Ctr, Wallops Isl, VA 23337 USA. Univ Miami, RSMAS Appl Marine Phys, Miami, FL 33152 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. NOAA, ARL, Field Res Div, Idaho Falls, ID USA. USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. FLP Energy, Juno Beach, FL USA. Natl Ocean & Atmospher Adm, Oak Ridge, TN USA. RP Sun, J (reprint author), Natl Ctr Atmospher Res, MMM, POB 3000,3450 Mitchell Lane, Boulder, CO 80307 USA. EM jsun@ucar.edu RI Burns, Sean/A-9352-2008; Sun, Jielun/H-6576-2015 OI Burns, Sean/0000-0002-6258-1838; Sun, Jielun/0000-0003-3271-7914 NR 51 TC 7 Z9 7 U1 0 U2 5 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 JUL PY 2005 VL 22 IS 7 BP 869 EP 885 DI 10.1175/JTECH1729.1 PG 17 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 960MA UT WOS:000231595500007 ER PT J AU Li, LH Heymsfield, GM Tian, L Racette, PE AF Li, LH Heymsfield, GM Tian, L Racette, PE TI Measurements of ocean surface backscattering using an airborne 94-GHz cloud radar - Implication for calibration of airborne and spaceborne W-band radars SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID TRMM PRECIPITATION RADAR; SEA SCATTER; X-BAND; REFLECTIVITY; ATTENUATION; FREQUENCY; ANGLES; SLOPE; MODEL; GHZ AB Backscattering properties of the ocean surface have been widely used as a calibration reference for airborne and spaceborne microwave sensors. However, at millimeter-wave frequencies, the ocean surface backscattering mechanism is still not well understood, in part, due to the lack of experimental measurements. During the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE), measurements of ocean surface backscattering were made using a 94-GHz (W band) cloud radar on board a NASA ER-2 high-altitude aircraft. This unprecedented dataset enhances our knowledge about the ocean surface scattering mechanism at 94 GHz. The measurement set includes the normalized ocean surface cross section over a range of the incidence angles under a variety of wind conditions. It was confirmed that even at 94 GHz, the normalized ocean surface radar cross section, sigma(o) is insensitive to surface wind conditions near a 10 degrees incidence angle, a finding similar to what has been found in the literature for lower frequencies. Analysis of the radar measurements also shows good agreement with a quasi-specular scattering model at low incidence angles. The results of this work support the proposition of using the ocean surface as a calibration reference for airborne millimeter-wave cloud radars and for the ongoing NASA CloudSat mission, which will use a 94-GHz spaceborne cloud radar for global cloud measurements. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Li, LH (reprint author), NASA, Goddard Space Flight Ctr, Code 912,Bldg 33,Rm C426, Greenbelt, MD 20771 USA. EM lihua@agnes.gsfc.nasa.gov NR 38 TC 27 Z9 28 U1 0 U2 4 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 JUL PY 2005 VL 22 IS 7 BP 1033 EP 1045 DI 10.1175/JTECH1722.1 PG 13 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 960MA UT WOS:000231595500018 ER PT J AU Kara, AB Hurlburt, HE Wallcraft, AJ AF Kara, AB Hurlburt, HE Wallcraft, AJ TI Stability-dependent exchange coefficients for air-sea fluxes SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID GLOBAL OCEAN MODEL; SOUTH CHINA SEA; WIND STRESS; BULK PARAMETERIZATION; SURFACE ROUGHNESS; FLOW DISTORTION; WATER TURBIDITY; VAPOR-PRESSURE; ATLANTIC-OCEAN; ENERGY FLUX AB This study introduces exchange coefficients for wind stress (C-D), latent heat flux (C-L), and sensible heat flux (Cs) over the global ocean. They are obtained from the state-of-the-art Coupled Ocean-Atmosphere Response Experiment (COARE) bulk algorithm (version 3.0). Using the exchange coefficients from this bulk scheme, C-D, C-L, and C-s are then expressed as simple polynomial functions of air-sea temperature difference (T-a - T-s)-where air temperature (T-a) is at 10 m, wind speed (V-a) is at 10 m, and relative humidity (RH) is at the air-sea interface-to parameterize stability. The advantage of using polynomial-based exchange coefficients is that they do not require any iterations for stability. In addition, they agree with results from the COARE algorithm but at approximate to 5 times lower computation cost, an advantage that is particularly needed for ocean general circulation models (OGCMs) and climate models running at high horizontal resolution and short time steps. The effects of any water vapor flux in calculating the exchange coefficients are taken into account in the polynomial functions, a feature that is especially important at low wind speeds (e.g., V-a < 5 m s(-1)) because air-sea mixing ratio difference can have a major effect on the stability, particularly in tropical regions. Analyses of exchange coefficients demonstrate the fact that water vapor can have substantial impact on air-sea exchange coefficients at low wind speeds. An example application of the exchange coefficients from the polynomial approach is the recalculation of climatological mean wind stress magnitude from 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) data in the North Pacific Ocean over 1979-2002. Using ECMWF 10-m winds and the authors' methodology provides accurate surface stresses while largely eliminating the orographically induced Gibb's waves found in the original ERA-40 surface wind stresses. These can have a large amplitude near mountainous regions and can extend far into the ocean interior. This study introduces exchange coefficients of air-sea fluxes, which are applicable to the wide range of conditions occurring over the global ocean, including the air-sea stability differences across the Gulf Stream and Kuroshio, regions which have been the subject of many climate model studies. This versatility results because CD, C, and C. are determined for V, values of 1 to 40 m s(-1), (T-a - T-s), intervals of -8 degrees to 7 degrees C, and RH values of 0% to 100%. Exchange coefficients presented here are called the Naval Research Laboratory (NRL) Air-Sea Exchange Coefficients (NASEC) and they are suitable for a wide range of air-sea interaction studies and model applications. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. RP Kara, AB (reprint author), USN, Res Lab, Stennis Space Ctr, Code 7320,Bldg 1009, Stennis Space Ctr, MS 39529 USA. EM kara@nrlssc.navy.mil NR 29 TC 49 Z9 51 U1 0 U2 3 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 JUL PY 2005 VL 22 IS 7 BP 1080 EP 1094 DI 10.1175/JTECH1747.1 PG 15 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 960MA UT WOS:000231595500022 ER PT J AU Mayr, HG Mengel, JG Talaat, ER Porter, HS Chan, KL AF Mayr, HG Mengel, JG Talaat, ER Porter, HS Chan, KL TI Mesospheric non-migrating tides generated with planetary waves: I. Characteristics SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article DE non-migrating tides; gravity waves; mesosphere dynamics; numerical modeling ID DOPPLER-SPREAD PARAMETERIZATION; ATMOSPHERE RESEARCH SATELLITE; INTERNAL GRAVITY-WAVES; LARGE-SCALE DYNAMICS; MIDDLE ATMOSPHERE; DIURNAL TIDES; LOWER THERMOSPHERE; TIDAL VARIABILITY; MOMENTUM DEPOSITION; CIRCULATION MODEL AB In light of the measurements from the TIMED spacecraft and coordinated ground-based observations, we discuss results from a modeling study with our Numerical Spectral Model (NSM), which specifically deals with the non-migrating tides generated in the mesosphere. The NSM extends from the ground to the thermosphere, incorporates Hines' Doppler Spread Parameterization for small-scale gravity waves (GWs), and it describes the major dynamical features of the atmosphere including the wave driven equatorial oscillations (QBO and SAO), and the seasonal variations of tides and planetary waves (PWs). Accounting solely for the excitation Sources of the solar migrating tides, the NSM generates through nonlinear interactions also non-migrating tides in the mesosphere that are comparable in magnitude to those observed. (The important non-migrating tides generated explicitly by processes like tropospheric latent heat release and convection are not included.) Large non-migrating tides ire produced in the diurnal and semi-diurnal oscillations for the zonal mean (wave number m = 0) and in the semidiurnal oscillation for m = 1. In general, significant eastward and westward propagating tides are generated for all the zonal wave numbers m = 1-4. To identify the cause, the NSM is run without the solar heating for the zonal mean (m = 0), and the amplitudes of the resulting non-migrating tides are then negligibly small. In this case, the PWs generated by instabilities are artificially suppressed. This leads to the conclusion that the non-migrating tides are produced through nonlinear interactions between PWs and migrating tides, as had been previously proposed. In the accompanying paper, we present results from numerical experiments, which demonstrate that GW filtering contributes significantly to produce the nonlinear coupling that is involved. Published by Elsevier Ltd. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. Furman Univ, Greenville, SC 29613 USA. Hong Kong Univ Sci & Technol, Hong Kong, Hong Kong, Peoples R China. RP Mayr, HG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM hmayr@pop900.gsfc.nasa.gov OI Chan, Kwing/0000-0002-6428-1812 NR 67 TC 27 Z9 27 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 JUL PY 2005 VL 67 IS 11 BP 959 EP 980 DI 10.1016/j.jastp.2005.03.002 PG 22 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 996VG UT WOS:000234202700005 ER PT J AU Mayr, HG Mengel, JG Talaat, ER Porter, HS Chan, KL AF Mayr, HG Mengel, JG Talaat, ER Porter, HS Chan, KL TI Mesospheric non-migrating tides waves: II. Influence of generated with planetary of gravity waves SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article DE non-migrating tides; gravity waves; mesosphere dynamics; numerical modeling ID RESOLUTION DOPPLER IMAGER; ATMOSPHERE RESEARCH SATELLITE; MIDDLE ATMOSPHERE; DIURNAL TIDES; TIDAL VARIABILITY; SPREAD PARAMETERIZATION; MOMENTUM DEPOSITION; LOWER THERMOSPHERE; CIRCULATION MODEL; SEMIDIURNAL TIDE AB In Part 1, we demonstrated with the numerical spectral model (NSM) that non-linear interactions between planetary waves (PWs) and migrating tides could generate in the upper mesosphere non-migrating tides that have amplitudes comparable to those observed. The NSM incorporates I-lines' Doppler spread parameterization (DSP) for small-scale gravity waves (GWs), which affect the dynamics of the mesosphere in numerous ways. The latitudinal (seasonal) reversals in the zonal circulation and temperature variations above 70 km, largely caused by GWs, contribute to the instabilities that generate the PWs, and the circulation filters the waves. The PWs in turn are amplified by the momentum deposition of upward propagating GWs, as are the migrating tides. The GWs thus affect the migrating tides and PWs, the building blocks of non-migrating tides. In the present paper, we present the results of two computer experiments, which indicate that the GWs also contribute significantly to the process of non-linear Coupling between PWs and tides. In one, we turn off the GW Source to show the effect oil the non-migrating tides. In the second case, we demonstrate the effect on the standing non-migrating diurnal tide by selectively Suppressing, for comparison, the time dependence of the GW momentum source for zonal wave number m = 0. Published by Elsevier Ltd. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. Furman Univ, Greenville, SC 29613 USA. Hong Kong Univ Sci & Technol, Hong Kong, Hong Kong, Peoples R China. RP Mayr, HG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM hmayr@pop900.gsfc.nasa.gov NR 40 TC 16 Z9 16 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 JUL PY 2005 VL 67 IS 11 BP 981 EP 991 DI 10.1016/j.jastp.2005.03.003 PG 11 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 996VG UT WOS:000234202700006 ER PT J AU Fyler, CA Reeder, TW Berta, A Antonelis, G Aguilar, A Androukaki, E AF Fyler, CA Reeder, TW Berta, A Antonelis, G Aguilar, A Androukaki, E TI Historical biogeography and phylogeny of monachine seals (Pinnipedia : Phocidae) based on mitochondrial and nuclear DNA data SO JOURNAL OF BIOGEOGRAPHY LA English DT Article DE historical biogeography; mixed model; molecular divergence estimates; Monachinae; nonparametric rate smoothing; partitioned Bayesian inference; phylogeny; Pinnipedia; seal biogeography ID BAYESIAN-INFERENCE; MONK SEAL; LIKELIHOOD; EVOLUTION; TREES; SUBSTITUTION; INFORMATION; CONFIDENCE; PARSIMONY; SEQUENCES AB Aim To determine the origin and diversification of monachine seals using a phylogenetic framework. Methods Molecular sequence data from three mitochondrial genes (cyt b, ND1 and 12S), and one nuclear marker (an intron from the alpha-lactalbumin gene) were examined from all extant species of monachine seals. Maximum likelihood and partitioned Bayesian inference were used to analyse separate and combined (mitochondrial + nuclear) data sets. Divergence times were estimated from the resultant phylogeny using nonparametric rate smoothing as implemented by the program r8s. Results Mirounga, Monachus and the Lobodontini form three well-supported clades within a monophyletic Monachinae. Lobodontini + Mirounga form a clade sister to Monachus. Molecular divergence dates indicate that the first split within the Monachinae (Lobodontini + Mirounga clade and Monachus) occurred between 11.8 and 13.8 Ma and Mirounga, Monachus and the Lobodontini originated 2.7-3.4, 9.1-10.8 and 10.0-11.6 Ma, respectively. Main conclusions Two main clades exist within Monachinae, Monachus and Lobodontini + Mirounga. Monachus, a warm water clade, originated in the North Atlantic and maintained the temperate water affinities of their ancestors as they diversified in the subtropic regions of the Northern Hemisphere. The cold-water clade, Lobodontini + Mirounga, dispersed southward to the cooler climates of the Southern Hemisphere. The Lobodontini continued south until reaching the Antarctic region where they diversified into the present-day fauna. Mirounga shows an anti-tropical distribution either reflective of a once cosmopolitan range that was separated by warming waters in the tropics or of transequatorial dispersal. C1 San Diego State Univ, Dept Biol, San Diego, CA 92182 USA. Natl Marine Fisheries Serv, Honolulu Lab, Honolulu, HI USA. Univ Barcelona, Dept Anim Biol, Barcelona, Spain. MOm Hellen Soc Study & Protect Monk Seal, Athens, Greece. RP Fyler, CA (reprint author), Univ Connecticut, Dept Ecol & Evolutionary Biol, 75 N Eagleville Rd U-3043, Storrs, CT 06269 USA. EM caroline.fyler@uconn.edu RI Aguilar, Alex/L-1283-2014 OI Aguilar, Alex/0000-0002-5751-2512 NR 59 TC 30 Z9 32 U1 4 U2 18 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0305-0270 EI 1365-2699 J9 J BIOGEOGR JI J. Biogeogr. PD JUL PY 2005 VL 32 IS 7 BP 1267 EP 1279 DI 10.1111/j.1365-2699.2005.01281.x PG 13 WC Ecology; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 934JU UT WOS:000229705900013 ER PT J AU Tan, XF Salama, F AF Tan, XF Salama, F TI Cavity ring-down spectroscopy and vibronic activity of benzo[ghi]perylene SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; DIFFUSE INTERSTELLAR BANDS; DENSITY-FUNCTIONAL THEORY; ELECTRONIC ABSORPTION-SPECTROSCOPY; CORRELATION-ENERGY; SUPERSONIC JET; ORGANIC-MOLECULES; OPTICAL CAVITY; PROGRAM RPAC; BASIS-SETS AB Gas-phase cavity ring-down spectroscopy of jet-cooled benzo[ghi]perylene (C22H12) in the 26 950-28 600-cm(-1) spectral range is reported for the first time. This study is part of our extensive laboratory astrophysics program for the study of interstellar polycyclic aromatic hydrocarbons. The observed spectrum shows an intermediate level structure and significant broadening and is associated with the vibronically coupled S-1((1)A(1))<- S-0((1)A(1)) and S-2(B-1(1))<- S-0((1)A(1)) electronic transitions. Time-dependent density-functional calculations were performed to calculate the energetics, vibrational frequencies, and normal coordinates of the S-1 and S-2 states. A simple vibronic model was employed to account for the vibronic interaction between the vibronic levels of the S-1 and S-2 states. The calculated vibronic spectrum is found to be in good agreement with the experimental spectrum. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Tan, XF (reprint author), NASA, Ames Res Ctr, Div Space Sci, Mail Stop 245-6, Moffett Field, CA 94035 USA. EM x.tan@jhu.edu; salama@nasa.gov RI Salama, Farid/A-8787-2009 OI Salama, Farid/0000-0002-6064-4401 NR 52 TC 25 Z9 25 U1 1 U2 7 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 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 2005 VL 123 IS 1 AR 014312 DI 10.1063/1.138907 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 945HM UT WOS:000230493600015 PM 16035840 ER PT J AU Maasch, KA Oglesby, RJ Fournier, A AF Maasch, KA Oglesby, RJ Fournier, A TI Barry Saltzman and the theory of climate SO JOURNAL OF CLIMATE LA English DT Biographical-Item AB Barry Saltzman was a giant in the fields of meteorology and climate science. A leading figure in the study of weather and climate for over 40 yr, he has frequently been referred to as the "father of modern climate theory." Ahead of his time in many ways, Saltzman made significant contributions to our understanding of the general circulation and spectral energetics budget of the atmosphere, as well as climate change across a wide spectrum of time scales. In his endeavor to develop a unified theory of how the climate system works, lie played a role in the development of energy balance models, statistical dynamical models, and paleoclimate dynamical models. He was a pioneer in developing meteorologically motivated dynamical systems, including the progenitor of Lorenz's famous chaos model. In applying his own dynamical-systems approach to long-term climate change, he recognized the potential for using atmospheric general circulation models in a complimentary way. In 1998, he was awarded the Carl-Gustaf Rossby medal, the highest honor of the American Meteorological Society "for his life-long contributions to the study of the global circulation and the evolution of the earth's climate." In this paper, the authors summarize and place into perspective some of the most significant contributions that Barry Saltzman made during his long and distinguished career. This short review also serves as an introduction to the papers in this special issue of the Journal of Climate dedicated to Barry's memory. C1 Univ Maine, Climate Change Inst, Orono, ME 04469 USA. Univ Maine, Dept Earth Sci, Orono, ME 04469 USA. NASA, MSFC NSSTC, Huntsville, AL USA. NCAR, ASP, GTP, Boulder, CO USA. RP Maasch, KA (reprint author), Univ Maine, Climate Change Inst, 5790 BGSC, Orono, ME 04469 USA. EM kirk.maasch@maine.edu RI Fournier, Aime/J-6366-2015 OI Fournier, Aime/0000-0002-5872-8307 NR 0 TC 1 Z9 1 U1 0 U2 1 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 JUL 1 PY 2005 VL 18 IS 13 BP 2141 EP 2150 DI 10.1175/JCLI3383.1 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 950XN UT WOS:000230892100001 ER PT J AU Hu, HJ Oglesby, RJ Marshall, S AF Hu, HJ Oglesby, RJ Marshall, S TI The simulation of moisture processes in climate models and climate sensitivity SO JOURNAL OF CLIMATE LA English DT Article ID WATER-VAPOR; NATIONAL CENTER; TEMPERATURE; CCM3; SURFACE; HUMIDITY; BUDGET; CYCLE AB General circulation models (GCMs) designed for projecting climatic change have exhibited a wide range of sensitivity. Therefore, projected surface warming with increasing CO2 varies considerably depending on which model is used. Despite notable advances in computing power and modeling techniques that have occurred over the past decade, uncertainties of model sensitivity have not been reduced accordingly. The sensitivity issue is investigated by examining two GCMs of very different modeling techniques and sensitivity, with attention focused on how moisture processes are treated in these models, how moisture simulations are affected by these processes, and how well these simulations compare to the observed and analyzed moisture field. Both GCMs predict increases of atmospheric moisture with doubled CO2, but the increment predicted by one model is substantially higher (approximately twice) than that predicted by the other. This same difference is seen in responses of the boundary layer diffusive moistening rate. Calculations with a radiative-convective model indicate that the differences in predicted equilibrium atmospheric moisture, including both column amount and vertical distribution, have contributed to the largest differences in model sensitivity between the two models. We argue that in order for climate models to be credible for prediction purposes, they must possess credible skills of simulating surface and boundary layer processes, which likely holds the key to overall moisture performance, its response to external forcing, and in turn to model sensitivity. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Rocky Mt Coll, Billings, MT USA. RP Hu, HJ (reprint author), Atmospher & Environm Res Inc, 131 Hartwell Ave, Lexington, MA 02421 USA. EM hhu@aer.com NR 24 TC 4 Z9 4 U1 0 U2 0 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 JUL 1 PY 2005 VL 18 IS 13 BP 2172 EP 2193 DI 10.1175/JCLI3384.1 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 950XN UT WOS:000230892100003 ER PT J AU Stephens, MY Oglesby, RJ Maxey, M AF Stephens, MY Oglesby, RJ Maxey, M TI A one-dimensional mixed layer ocean model for use in three-dimensional climate simulations: Control simulation compared to observations SO JOURNAL OF CLIMATE LA English DT Article ID SEA ICE; VARIABILITY; CYCLE; CCM3 AB A study has been made of the dynamic interactions between the surface layer of the ocean and the atmosphere using a climate model that contains a new approach to predicting the sea surface temperature (SST). The atmospheric conditions are simulated numerically with the NCAR Community Climate Model (CCM3). The SST is determined by a modified Kraus-Turner-type one-dimensional mixed layer ocean model (MLOM) for the upper ocean that has been coupled to CCM3. The MLOM simulates vertical ocean dynamics and demonstrates the effects of the seasonal variation of mixed layer depth and convective instability on the SST. A purely thermodynamic slab ocean model (SOM) is currently available for use with CCM3 to predict the SST. A large-scale ocean general circulation model (OGCM) may also be coupled to CCM3; however, the OGCM is computationally intensive and is therefore not a good tool for conducting multiple sensitivity studies. The MLOM provides an alternative to the SOM that contains seasonally and spatially specified mixed layer depths. The SOM also contains a heat flux correction called Q-flux that crudely accounts for ocean heat transport by artificially specifying a heat flux that forces the SOM to replicate the observed SST. The results of the coupled MLOM-CCM3 reveal that the MLOM may be used on a global scale and can therefore replace the standard coupled SOM-CCM3 that contains no explicit ocean dynamics. Additionally, stand-alone experiments of the MLOM that are forced with realistic winds, heat, and moisture fluxes show that the MLOM closely approximates the observed seasonal cycle of SST. C1 Spelman Coll, Dept Math, Atlanta, GA 30314 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Brown Univ, Providence, RI 02912 USA. RP Stephens, MY (reprint author), Spelman Coll, Dept Math, Atlanta, GA 30314 USA. EM mstephens@spelman.edu NR 26 TC 6 Z9 7 U1 1 U2 5 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 JUL 1 PY 2005 VL 18 IS 13 BP 2199 EP 2221 DI 10.1175/JCLI3380.1 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 950XN UT WOS:000230892100005 ER PT J AU Oglesby, RJ Stephens, MY Saltzman, B AF Oglesby, RJ Stephens, MY Saltzman, B TI The influence of ocean thermocline temperatures on the earth's surface climate SO JOURNAL OF CLIMATE LA English DT Article ID ATMOSPHERIC CO2; SNOW COVER; MODEL; SENSITIVITY; GLACIATION; CCM3; EVOLUTION; HISTORY; ALBEDO; WARM AB A coupled mixed layer-atmospheric general circulation model has been used to evaluate the impact of ocean thermocline temperatures (and by proxy those of the deep ocean) on the surface climate of the earth. Particular attention has been devoted to temperature regimes both warmer and cooler than at present. The mixed layer ocean model (MLOM) simulates vertical dynamics and thermodynamics in the upper ocean, including wind mixing and buoyancy effects, and has been coupled to the NCAR Community Climate Model (CCM3). Simulations were made with globally uniform thermocline warmings of +2 degrees, +5 degrees, and +10 degrees C, as well as a globally uniform cooling of -5 degrees C. A simulation was made with latitudinally varying changes in thermocline temperature such that the warming at mid- and high latitudes is much larger than at low latitudes. In all simulations, the response of surface temperature over both land and ocean was larger than that expected just as a result of the imposed thermocline temperature change, largely because of water vapor feedbacks. In this respect, the simulations were similar to those in which only changes in atmospheric carbon dioxide were imposed. In fact, when carbon dioxide was explicitly changed along with thermocline temperatures, the results were not much different than if only the thermocline temperatures were altered. Land versus ocean differences are explained largely by latent heat flux differences: the ocean is an infinite evaporative source, while land can be quite dry. The latitudinally varying case has a much larger response at mid- to high latitudes than at low latitudes; the high latitudes actually appear to effectively warm the low latitudes. Simulations exploring scenarios of glacial inception suggest that the deep ocean alone is not likely to be a key trigger but must operate in conjunction with other forcings, such as reduced carbon dioxide. Moist upland regions at mid- and high latitudes, and land regions adjacent to perennial sea ice, are the preferred locations for glacial inception in these runs. Finally, the model combination equilibrates very rapidly, meaning that a large number of simulations can be made for a fairly modest computational cost. A drawback to this is greatly reduced sensitivity to parameters such as atmospheric carbon dioxide, which requires a full response of the ocean. Thus, this approach can be considered intermediate between fixing, or prescribing, sea surface temperatures and a fully coupled modeling approach. C1 NASA, MSFC, NSSTC, Huntsville, AL 35805 USA. Spelman Coll, Atlanta, GA 30314 USA. Yale Univ, New Haven, CT USA. RP Oglesby, RJ (reprint author), NASA, MSFC, NSSTC, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM robert.j.oglesby@nasa.gov NR 35 TC 0 Z9 0 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUL 1 PY 2005 VL 18 IS 13 BP 2222 EP 2246 DI 10.1175/JCLI3382.1 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 950XN UT WOS:000230892100006 ER PT J AU Del Genio, AD Kovari, W Yao, MS Jonas, J AF Del Genio, AD Kovari, W Yao, MS Jonas, J TI Cumulus microphysics and climate sensitivity SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURES; WATER-VAPOR; PRECIPITATION PARTICLES; PART I; CLOUDS; CONVECTION; FEEDBACK; MODELS; SCHEME; ICE AB Precipitation processes in convective storms are potentially a major regulator of cloud feedback. An unresolved issue is how the partitioning of convective condensate between precipitation-size particles that fall out of updrafts and smaller particles that are detrained to form anvil clouds will change as the climate warms. Tropical Rainfall Measuring Mission (TRMM) observations of tropical oceanic convective storms indicate higher precipitation efficiency at warmer sea surface temperature (SST) but also suggest that cumulus anvil sizes, albedos, and ice water paths become insensitive to warming at high temperatures. International Satellite Cloud Climatology Project (ISCCP) data show that instantaneous cirrus and deep convective cloud fractions are positively correlated and increase with SST except at the highest temperatures, but are sensitive to variations in large-scale vertical velocity. A simple conceptual model based on a Marshall-Palmer drop size distribution, empirical terminal velocity-particle size relationships, and assumed cumulus updraft speeds reproduces the observed tendency for detrained condensate to approach a limiting value at high SST. These results suggest that the climatic behavior of observed tropical convective clouds is intermediate between the extremes required to support the thermostat and adaptive iris hypotheses. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY USA. SGT Inc, Inst Space Studies, New York, NY USA. RP NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM adelgenio@giss.nasa.gov RI Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 40 TC 64 Z9 64 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PD JUL 1 PY 2005 VL 18 IS 13 BP 2376 EP 2387 DI 10.1175/JCLI3413.1 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 950XN UT WOS:000230892100014 ER PT J AU Xu, KM Wong, TM Wielicki, BA Parker, L Eitzen, ZA AF Xu, KM Wong, TM Wielicki, BA Parker, L Eitzen, ZA TI Statistical analyses of satellite cloud object data from CERES. Part I: Methodology and preliminary results of the 1998 El nino/2000 La Nina SO JOURNAL OF CLIMATE LA English DT Article ID CONVECTION PARAMETERIZATION CRCP; BOUNDARY-LAYER CLOUDS; EXPLICIT SIMULATION; SPATIAL-RESOLUTION; CUMULUS ENSEMBLES; CLIMATE; RADIATION; MODEL; VALIDATION; PACIFIC AB This study presents an objective classification methodology that uses Earth Observing System (EOS) satellite data to classify distinct "cloud objects" defined by cloud-system types, sizes, geographic locations, and matched large-scale environments. This analysis method identifies a cloud object as a contiguous region of the earth with a single dominant cloud-system type. It determines the shape and size of the cloud object from the satellite data and the cloud-system selection criteria. The statistical properties of the identified cloud objects are analyzed in terms of probability density functions (PDFs) based upon the Clouds and the Earth's Radiant Energy System (CERES) Single Satellite Footprint (SSE) data. Four distinct types of oceanic cloud objects-tropical deep convection, boundary layer cumulus, transition stratocumulus, and solid stratus-are initially identified from the CERES data collected from the Tropical Rainfall Measuring Mission (TRMM) satellite for this study. Preliminary results are presented from the analysis of the grand-mean PDFs of these four distinct types of cloud objects associated with the strong 1997/98 El Nino in March 1998 and the very weak 2000 La Nino in March 2000. A majority of the CERES footprint statistical characteristics of observed tropical deep convection are similar between the two periods in spite of the climatological contrast. There are, however, statistically significant differences in some cloud macrophysical properties such as the cloud-top height and cloud-top pressure and moderately significant differences in outgoing longwave radiation (OLR), cloud-top temperature, and ice diameter. The footprint statistical characteristics of the three observed boundary layer cloud-system types are distinctly different from one another in all cloud microphysical, macrophysical, optical properties, and radiative fluxes. The differences between the two periods are not significant for most cloud microphysical and optical properties and the top-of-the-atmosphere albedo, but are statistically significant for some cloud macrophysical properties and OLR. These characteristics of the grand-mean PDFs of cloud microphysical, macrophysical, and optical properties and radiative fluxes can be usefully compared with cloud model simulations. Furthermore, the proportion of different boundary layer cloud types is changed between the two periods in spite of small differences in their grand-mean statistical properties. An increase of the stratus population and a decrease of the cumulus population are evident in the El Nino period compared to the very weak La Nino period. The number of the largest tropical convective cloud objects is larger during the El Nino period, but the total number of tropical convective cloud objects is approximately the same in the two periods. C1 NASA, Langley Res Ctr, Climate Sci Branch, Hampton, VA 23681 USA. Sci Applicat Int Corp, Hampton, VA USA. Colorado State Univ, Ft Collins, CO 80523 USA. RP Xu, KM (reprint author), NASA, Langley Res Ctr, Climate Sci Branch, Hampton, VA 23681 USA. EM Kuan-Man.Xu@nasa.gov RI Xu, Kuan-Man/B-7557-2013 OI Xu, Kuan-Man/0000-0001-7851-2629 NR 36 TC 42 Z9 42 U1 0 U2 6 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 JUL 1 PY 2005 VL 18 IS 13 BP 2497 EP 2514 DI 10.1175/JCLI3418.1 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 950XN UT WOS:000230892100022 ER PT J AU Kobayashi, T Simon, DL AF Kobayashi, T Simon, DL TI Evaluation of an enhanced bank of Kalman filters for in-flight aircraft engine sensor fault diagnostics SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 13-17, 2004 CL Vienna, AUSTRIA AB In this paper an approach for in-flight fault detection and isolation (FDI) of aircraft engine sensors based on a bank of Kalman filters is developed. This approach utilizes multiple Kalman filters, each of which is designed based on a specific fault hypothesis. When the propulsion system experiences a fault, only one Kalman filter with the correct hypothesis is able to maintain the nominal estimation performance. Based on this knowledge, the isolation of faults is achieved. Since the propulsion system may experience component and actuator faults as well, a sensor FDI system must be robust in terms of avoiding misclassifications of any anomalies. The proposed approach utilizes a bank of (m+1) Kalman filters where m is the number of sensors being monitored. One Kalman filter is used for the detection of component and actuator faults while each of the other m filters detects a fault in a specific sensor With this setup, the overall robustness of the sensor FDI system to anomalies is enhanced. Moreover numerous component fault events can be accounted for by the FDI system. The sensor FDI system is applied to a nonlinear simulation of a commercial aircraft gas turbine engine, and its performance is evaluated at multiple power settings at a cruise operating point using various fault scenarios. C1 QSS Grp Inc, Cleveland, OH 44135 USA. USA, Res Lab, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Kobayashi, T (reprint author), QSS Grp Inc, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 9 TC 24 Z9 30 U1 1 U2 11 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 JUL PY 2005 VL 127 IS 3 BP 497 EP 504 DI 10.1115/1.1850505 PG 8 WC Engineering, Mechanical SC Engineering GA 948HG UT WOS:000230706100007 ER PT J AU Delgado, IR Halford, GR Steinetz, BM Rimnac, CM AF Delgado, IR Halford, GR Steinetz, BM Rimnac, CM TI Strain-life assessment of grainex Mar-M 247 for NASA's turbine seal test facility SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 13-17, 2004 CL Vienna, AUSTRIA AB NASA's turbine seal facility tests air-to-air seals for advanced jet engines. High temperature, speed, and pressure combinations limit test disk life, due to crack initiation in the Grainex Mar-M 247 disk bolt holes. An inspection interval is determined to ensure safe operation. Fatigue strain-life data is presented for test specimens from a test disk. Strain-life models (Manson-Hirschberg method of universal slopes, Halford-Nachtigall mean stress method, and modified Morrow method) were compared to experiment. Using experimental data at -99.95% prediction levels, accounting for six bolt holes at 0.5% total strain and 649 degrees C, the test disk should be inspected after 665 cycles. C1 NASA, Vehicle Technol Directorate, USA, Res Lab,Glenn Res Ctr, Cleveland, OH 44135 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. RP Delgado, IR (reprint author), NASA, Vehicle Technol Directorate, USA, Res Lab,Glenn Res Ctr, Cleveland, OH 44135 USA. NR 11 TC 2 Z9 2 U1 0 U2 3 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 JUL PY 2005 VL 127 IS 3 BP 615 EP 620 DI 10.1115/1.1852563 PG 6 WC Engineering, Mechanical SC Engineering GA 948HG UT WOS:000230706100021 ER PT J AU Oman, L Robock, A Stenchikov, G Schmidt, GA Ruedy, R AF Oman, L Robock, A Stenchikov, G Schmidt, GA Ruedy, R TI Climatic response to high-latitude volcanic eruptions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC AEROSOLS; SURFACE-TEMPERATURE; MODEL SIMULATION; OPTICAL DEPTH; 20TH-CENTURY; CLOUDS AB Strong volcanic eruptions can inject large amounts of SO2 into the lower stratosphere, which over time, are converted into sulfate aerosols and have the potential to impact climate. Aerosols from tropical volcanic eruptions like the 1991 Mount Pinatubo eruption spread over the entire globe, whereas high-latitude eruptions typically have aerosols which remain in the hemisphere in which they where injected. This causes their largest radiative forcing to be extratropical, and the climate response should be different from that of tropical eruptions. We conducted a 20-member ensemble simulation of the climate response to the Katmai eruption (58 degrees N) of 6 June 1912 using the NASA Goddard Institute for Space Studies ModelE climate model. We also produced an additional 20-member ensemble for a 3 times Katmai (3x Katmai) eruption to see the impact the strength of the eruption has on the radiative as well as the dynamical responses. The results of these simulations do not show a positive Arctic Oscillation response like past simulations of tropical volcanic eruptions, but we did find significant cooling over southern Asia during the boreal winter. The first winter following Katmai and the second winter following 3x Katmai showed strong similarities in lower stratospheric geopotential height anomalies and sea level pressure anomalies, which occurred when the two cases had similar optical depth perturbations. These simulations show that the radiative impact of a high-latitude volcanic eruption was much larger than the dynamical impact at high latitudes. In the boreal summer, however, strong cooling over the Northern Hemisphere landmasses caused a decrease in the Asian monsoon circulation with significant decreases of up to 10% in cloud cover and warming over northern India. Thus the main dynamical impact of high-latitude eruptions is in the summer over Asia. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY USA. SGT Inc, New York, NY USA. RP Rutgers State Univ, Dept Environm Sci, 14 Coll Farm Rd, New Brunswick, NJ 08903 USA. EM oman@cep.rutgers.edu RI Oman, Luke/C-2778-2009; Schmidt, Gavin/D-4427-2012; Georgiy, Stenchikov/J-8569-2013; Robock, Alan/B-6385-2016 OI Oman, Luke/0000-0002-5487-2598; Schmidt, Gavin/0000-0002-2258-0486; NR 31 TC 79 Z9 80 U1 7 U2 20 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 JUL 1 PY 2005 VL 110 IS D13 AR D13103 DI 10.1029/2004JD005487 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 945DJ UT WOS:000230481700004 ER PT J AU Crespo, LG Kenny, SP AF Crespo, LG Kenny, SP TI Reliability-based control design for uncertain systems SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID EFFICIENT SAMPLING TECHNIQUE; ROBUST-CONTROL AB A robust control design methodology for systems with probabilistic parametric uncertainty is presented. Control design is carried out by solving a reliability-based multiobjective optimization problem where the probability of violating design requirements is minimized. Simultaneously, failure domains are optimally enlarged to enable global improvements in the closed-loop performance. To enable an efficient numerical implementation, a hybrid approach for estimating reliability metrics is developed. This approach, which integrates deterministic sampling and asymptotic approximations, greatly reduces the numerical burden associated with complex probabilistic computations without compromising the accuracy of the results. Examples using output-feedback and full-state feedback with state estimation are used to demonstrate the methodology. C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Guidance & Control Branch, Hampton, VA 23681 USA. RP Crespo, LG (reprint author), Natl Inst Aerosp, 144 Res Dr, Hampton, VA 23666 USA. NR 19 TC 10 Z9 11 U1 0 U2 2 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 JUL-AUG PY 2005 VL 28 IS 4 BP 649 EP 658 DI 10.2514/1.9127 PG 10 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 944OI UT WOS:000230438000009 ER PT J AU Seywald, H Roithmayr, CM Troutman, PA ParK, SY AF Seywald, H Roithmayr, CM Troutman, PA ParK, SY TI Fuel-optimal transfers between coplanar circular orbits using variable-specific-impulse engines SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article; Proceedings Paper CT AAS/AIAA 13th Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL Ponce, PR SP AAS, Amer Inst Aeronaut & Astronaut ID LOW-THRUST AB Minimum fuel circular-to-circular low-thrust orbital transfers with prescribed transfer time and with the thrust always directed parallel to the velocity vector are developed for a variable-specific-impulse system. The changeable specific impulse serves as the control variable. The power input is assumed to be constant, and the resulting thrust magnitude is inversely proportional to the chosen specific impulse. With these engine specifications, and under the assumption that the thrust magnitude always remains small compared to the gravitational forces, it is shown that the optimal specific impulse profile increases linearly with time. The associated optimal thrust magnitude is proportional to the vehicle mass; that is, the thrust per unit of vehicle mass remains constant. The mass fraction obtained with variable specific impulse is shown to be greater than or equal to that obtained with constant specific impulse; the advantage can be significant for orbital transfers with large changes in the semimajor axis. C1 Analyt Mech Associates Inc, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Yonsei Univ, Dept Astron & Space Sci, Ctr Astrodynam & Space Technol, Seoul 120749, South Korea. RP Seywald, H (reprint author), Analyt Mech Associates Inc, 303 Butler Farm Rd,Suite 104, Hampton, VA 23666 USA. EM seywald@ama-inc.com; c.m.roithmayr@larc.nasa.gov; p.a.troutman@larc.nasa.gov; spark@galaxy.yonsei.ac.kr RI Park, Sang-Young/F-5989-2013 NR 18 TC 6 Z9 7 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 JUL-AUG PY 2005 VL 28 IS 4 BP 795 EP 800 DI 10.2514/1.7257 PG 6 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 944OI UT WOS:000230438000025 ER PT J AU Sharma, G Badescu, M Dubey, A Mavroidis, C Tomassone, SM Yarmush, ML AF Sharma, G Badescu, M Dubey, A Mavroidis, C Tomassone, SM Yarmush, ML TI Kinematics and workspace analysis of protein based nano-actuators SO JOURNAL OF MECHANICAL DESIGN LA English DT Article ID MEMBRANE-FUSION; CONFORMATIONAL TRANSITIONS; MOLECULAR-CONFORMATIONS; INFLUENZA HEMAGGLUTININ; STRUCTURAL BASIS; MOTORS; GLYCOPROTEIN; VIRUS; ECTODOMAIN; GP41 AB In this paper a novel nanoscale protein based nano actuator concept is described. Molecular kinematic computational tools are developed and included in our Matlab Biokinematics Toolbox to study the protein nanomotors performance using geometric criteria. The computational tools include the development of the molecular motor direct and Inverse kinematics using the protein's Denavit and Hartenberg parameters and the corresponding homogeneous transformation matrices. Furthermore, the workspace calculation and analysis of the protein motor is performed. C1 Northeastern Univ, Dept Mech & Ind Engn, Boston, MA 02115 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Rutgers State Univ, Dept Mech & Aerosp Engn, Piscataway, NJ 08854 USA. Rutgers State Univ, Dept Chem & Biochem Engn, Piscataway, NJ 08854 USA. Rutgers State Univ, Dept Biomed Engn, Piscataway, NJ 08854 USA. RP Northeastern Univ, Dept Mech & Ind Engn, 360 Huntington Ave, Boston, MA 02115 USA. EM mavro@coe.neu.edu NR 47 TC 15 Z9 15 U1 3 U2 4 PU ASME PI NEW YORK PA TWO PARK AVE, NEW YORK, NY 10016-5990 USA SN 1050-0472 J9 J MECH DESIGN JI J. Mech. Des. PD JUL PY 2005 VL 127 IS 4 BP 718 EP 727 DI 10.1115/1.1900751 PG 10 WC Engineering, Mechanical SC Engineering GA 948HM UT WOS:000230706700026 ER PT J AU Carver, RL Peng, HQ Sadana, AK Nikolaev, P Arepalli, S Scott, CD Billups, WE Hauge, RH Smalley, RE AF Carver, RL Peng, HQ Sadana, AK Nikolaev, P Arepalli, S Scott, CD Billups, WE Hauge, RH Smalley, RE TI A model for nucleation and growth of single wall carbon nanotubes via the HiPco process: A catalyst concentration study SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE SWNT; HiPco; nucleation; growth; catalyst AB Using the High Pressure carbon monoxide (HiPco) reactor we conducted an experiment on the effects of changing the catalyst concentration. With each catalyst concentration tested the resulting raw HiPco material was characterized for average SWNT lengths, SWNT diameters, residual iron particle size, and large fullerene content. We were able to determine trends in each of these characteristics as the catalyst concentration was changed. As the catalyst concentration was decreased SWNT lengths increased, SWNT diameters increased, the residual iron particle size increased, and the large fullerene content decreased. From these trends we have developed a Competitive Growth model for nucleation and growth of SWNTs via the HiPco process. C1 Rice Univ, Dept Phys, Houston, TX 77005 USA. Rice Univ, Dept Chem, Houston, TX 77005 USA. Rice Univ, Carbon Nanotechnol Lab, Houston, TX 77005 USA. NASA, JSC, GB Tech, Houston, TX 77058 USA. RP Smalley, RE (reprint author), Rice Univ, Dept Phys, Houston, TX 77005 USA. RI Hauge, Robert/A-7008-2011; Arepalli, Sivaram/A-5372-2010; Nikolaev, Pavel/B-9960-2009 OI Hauge, Robert/0000-0002-3656-0152; NR 7 TC 21 Z9 21 U1 0 U2 11 PU AMER SCIENTIFIC PUBLISHERS PI STEVENSON RANCH PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD JUL PY 2005 VL 5 IS 7 BP 1035 EP 1040 DI 10.1166/jnn.2005.180 PG 6 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 942XN UT WOS:000230316300004 PM 16108423 ER PT J AU Kobayashi, T Simon, DL AF Kobayashi, T Simon, DL TI Hybrid neural-network genetic-algorithm technique for aircraft engine performance diagnostics SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA/ASME/SAE/ASEE 37th Joint Propulsion Conference CY JUL 08-11, 2001 CL Salt Lake City, UT SP Amer Inst Aeronaut & Astronaut, ASME, SAE, ASEE ID GAS-PATH-ANALYSIS AB In this paper, a model-based diagnostic method, which utilizes neural networks and genetic algorithms, is investigated. Neural networks are applied to estimate the engine internal health, and genetic algorithms are applied for sensor bias detection and estimation. This hybrid approach takes advantage of the nonlinear estimation capability provided by neural networks while improving the robustness to measurement uncertainty through the application of genetic algorithms. The hybrid diagnostic technique also has the ability to rank multiple potential solutions for a given set of anomalous sensor measurements in order to reduce false alarms and missed detections. The performance of the hybrid diagnostic technique is evaluated through some case studies derived from a turbofan engine simulation. The results show that this approach is promising for reliable diagnostics of aircraft gas turbine engines. C1 QSS Grp Inc, Cleveland, OH 44135 USA. NASA, John H Glenn Res Ctr Lewis Field, USA, Res Lab, Cleveland, OH 44135 USA. RP Kobayashi, T (reprint author), QSS Grp Inc, Cleveland, OH 44135 USA. NR 14 TC 15 Z9 16 U1 0 U2 5 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 JUL-AUG PY 2005 VL 21 IS 4 BP 751 EP 758 DI 10.2514/1.9881 PG 8 WC Engineering, Aerospace SC Engineering GA 945YV UT WOS:000230539800021 ER PT J AU Terrier, DA Lu, FK AF Terrier, DA Lu, FK TI Aerodynamically controlled expansion nozzle for short takeoff and vertical landing aircraft SO JOURNAL OF PROPULSION AND POWER LA English DT Article C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Texas, Dept Mech & Aerosp Engn, Arlington, TX 76019 USA. RP Terrier, DA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM Manager@LMAC.com NR 7 TC 1 Z9 1 U1 0 U2 0 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 JUL-AUG PY 2005 VL 21 IS 4 BP 763 EP 765 DI 10.2514/1.13729 PG 3 WC Engineering, Aerospace SC Engineering GA 945YV UT WOS:000230539800024 ER PT J AU Glaessgen, EH Reeder, JR Sleight, DW Wang, JT Raju, IS Harris, CE AF Glaessgen, EH Reeder, JR Sleight, DW Wang, JT Raju, IS Harris, CE TI Debonding failure of sandwich-composite cryogenic fuel tank with internal core pressure SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB A summary of the failure analyses and testing that were conducted to determine the cause of the X-33 liquid-hydrogen tank failure is presented. Ply-level stress analyses were conducted to explain the formation of microcracks in the plies of the inner and outer facesheet laminates of the honeycomb sandwich walls of the tank under known thermal and mechanical loads. The microcracks allowed the ingression of liquid- and gaseous-hydrogen and gaseous-nitrogen purge gas that produced higher than expected sandwich core pressures in the tank. Single cantilever beam tests were used to determine the toughness of the interface between the facesheets and honeycomb core. Fracture mechanics analyses were developed to determine strain-energy release rates for known foreign object debris shapes and sizes and known and statistically possible core internal pressures. The fracture mechanics analyses were validated by comparing with results of blowoff tests that were fabricated from undamaged tank sandwich material. Strain-energy release rates from the validated analyses were then compared with known and statistically possible values of toughness determined from the single cantilever beam tests. These analyses and tests were then used to substantiate a scenario for failure of the X-33 liquid-hydrogen tank that includes microcracking of the inner facesheets and ensuing ingression of hydrogen and nitrogen, a low bondline strength and toughness, and the presence of foreign object debris. C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Glaessgen, EH (reprint author), NASA Langley Res Ctr, Hampton, VA 23681 USA. NR 9 TC 6 Z9 6 U1 2 U2 6 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 JUL-AUG PY 2005 VL 42 IS 4 BP 613 EP 627 DI 10.2514/1.5567 PG 15 WC Engineering, Aerospace SC Engineering GA 954EM UT WOS:000231136900005 ER PT J AU Desai, PN Schofield, JT Lisano, ME AF Desai, PN Schofield, JT Lisano, ME TI Flight reconstruction of the Mars Pathfinder disk-gap-band parachute drag coefficients SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA 17th Aerodynamic Decelerator Systems Technology Conference CY MAY 19, 2003 CL Monterey, CA SP Amer Inst Aeronaut & Astronaut AB On 4 July 1997, the Mars Pathfinder (MPF) mission successfully landed on Mars. The entry, descent, and landing (EDL) scenario employed the use of a disk-gap-band parachute design to decelerate the Lander. Flight reconstruction of the entry using MPF flight accelerometer data revealed that the MPF parachute decelerated slower than predicted. In the summer of 2003, the Mars Exploration Rover (MER) mission sent two Landers to the surface of Mars arriving in January 2004. The MER mission uses a similar EDL scenario and parachute design to that employed by MPF. As a result, characterizing the degree of underperformance of the MPF parachute system is critical for the MER EDL trajectory design. An overview of the methodology used to estimate the MPF parachute drag coefficient as experienced on Mars is provided. C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Desai, PN (reprint author), NASA Langley Res Ctr, Hampton, VA 23681 USA. EM prasun.n.desai@nasa.gov; John.T.Schofield@jpl.nasa.gov; Michael.E.Lisano@jpl.nasa.gov NR 7 TC 2 Z9 3 U1 1 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 JUL-AUG PY 2005 VL 42 IS 4 BP 672 EP 676 DI 10.2514/1.5996 PG 5 WC Engineering, Aerospace SC Engineering GA 954EM UT WOS:000231136900011 ER PT J AU Reed, RA Nolen, MK Zolensky, ME Bankman, I Giles, J Lang, P Mishchenko, MI Ross, MN AF Reed, RA Nolen, MK Zolensky, ME Bankman, I Giles, J Lang, P Mishchenko, MI Ross, MN TI Lidar backscatter properties of Al2O3 rocket exhaust particles SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID MOTOR EXHAUST; SCATTERING MATRIX; PLUMES; STRATOSPHERE; SIZE; LIMITATIONS; WATER; MODEL AB The lidar backscatter cross sections of aluminum-oxide rocket exhaust particles are sensitive to slight deviations from their nominal spherical shape. We have therefore determined the distribution of particle shapes using automated image analysis of scanning electron microscope particle photographs. These shape statistics were used in conjunction with T-matrix calculations for nonspherical particles to estimate the backscatter properties of representative rocket exhaust particles. For the range of particle sizes and nonsphericities epsilon relevant to exhaust plumes, both the backscatter intensity and depolarization scale approximately with the product of nonsphericity epsilon times the particle radius (Er). This correlation allows us to formulate a simple model for both the backscatter intensity and the depolarization of typical Al2O3 rocket exhaust particles. This model is applied to a recent particle collection from the exhaust plume of a Titan-IVA rocket obtained from the NASA WB-57F high-altitude research aircraft at an altitude of 19 km. C1 Jacobs Sverdrup Corp, Arnold AFB, TN 37389 USA. NASA Johnson Space Ctr, Houston, TX 77058 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Aerosp Corp, El Segundo, CA 90009 USA. RP Reed, RA (reprint author), Jacobs Sverdrup Corp, Arnold AFB, TN 37389 USA. RI Mishchenko, Michael/D-4426-2012 NR 27 TC 5 Z9 5 U1 2 U2 6 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 JUL-AUG PY 2005 VL 42 IS 4 BP 711 EP 715 DI 10.2514/1.7551 PG 5 WC Engineering, Aerospace SC Engineering GA 954EM UT WOS:000231136900016 ER PT J AU Delleur, AM Propp, TW AF Delleur, AM Propp, TW TI Operational workarounds for the space station beta gimbal anomaly SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA 41st Aerospace Sciences Meeting CY JAN 06-09, 2003 CL RENO, NV SP Amer Inst Aeronaut & Astronaut AB The International Space Station (ISS) is the largest and most complex spacecraft ever assembled and operated in orbit. The first U.S. photovoltaic module, containing two solar arrays, was launched, installed, and activated in early December 2000. After the first week of continuously rotating the U.S. solar arrays, engineering personnel in the International Space Station Mission Evaluation Room observed higher than expected electrical currents on the drive motor in one of the beta gimbal assemblies, the mechanism used to maneuver a U.S. solar array. The magnitude of the motor currents continued to increase over time on both beta gimbal assemblies, creating concerns about the ability of the gimbals to continue pointing the solar arrays towards the sun, a function critical for continued assembly of the ISS. A number of engineering disciplines convened in May 2001 to address this on-orbit hardware anomally This paper reviews the International Space Station electrical power system analyses performed to develop viable operational workarounds that would minimize beta gimbal assembly use while maintaining sufficient solar-array power to continue assembly of the International Space Station. Additionally, electrical power system analyses performed in support of on-orbit beta gimbal assembly troubleshooting exercises are reviewed. C1 NASA John H Glenn Res Ctr, Cleveland, OH 44135 USA. Boeing Co, Houston, TX 77059 USA. RP Delleur, AM (reprint author), NASA John H Glenn Res Ctr, Cleveland, OH 44135 USA. EM ann.m.delleur@grc.nasa.gov; timothy.w.propp@boeing.com NR 6 TC 0 Z9 0 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 JUL-AUG PY 2005 VL 42 IS 4 BP 721 EP 728 DI 10.2514/1.5238 PG 8 WC Engineering, Aerospace SC Engineering GA 954EM UT WOS:000231136900018 ER PT J AU Perez, G Brentner, KS Bres, GA Jones, HE AF Perez, G Brentner, KS Bres, GA Jones, HE TI A first step toward the prediction of rotorcraft maneuver noise SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT 58th Annual Forum of the American-Helicopter-Society CY JUN 11-13, 2002 CL MONTREAL, CANADA SP Amer Helicopter Soc ID SOUND AB Over the past decade, stricter noise standards for civil aircraft operations and the need for greater stealth in a military environment have lead to a sustained interest in rotorcraft noise prediction. Although great progress has been made, development of the acoustic codes capable of predicting rotorcraft maneuver noise is lacking. The purpose of this paper is to demonstrate the potential impact maneuvering flight may have on rotor noise generation through initial noise predictions with a new rotor noise prediction code PSU-WOPWOP. This code is a necessary first step toward analyzing and understanding the additional noise generated during maneuvers--especially transient maneuvers. In this paper the predicted acoustic directivity for a helicopter in a transient descent condition is presented and compared to that of a steady three-degree descent path. Both main and tail rotor noise are predicted. The CAMRAD-2 comprehensive analysis code is used to approximate the time-dependent rotor blade loading and flight dynamics. In these initial predictions, a representative (but simplified) maneuver tends to significantly increase the noise intensity and change the directivity. These changes impact both low and mid frequencies-as much as the contribution of the tail rotor. An approximate quasisteady noise prediction is used to demonstrate that the increased noise in the transient maneuver in is not accounted for by the change in rotor thrust alone. C1 Penn State Univ, University Pk, PA 16802 USA. NASA, Langley Res Ctr, USA, Aeroflightdynam Directore,AMRDEC, Hampton, VA 23665 USA. RP Perez, G (reprint author), Penn State Univ, University Pk, PA 16802 USA. NR 17 TC 1 Z9 2 U1 0 U2 2 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 JUL PY 2005 VL 50 IS 3 BP 230 EP 237 PG 8 WC Engineering, Aerospace SC Engineering GA 953PX UT WOS:000231092700002 ER PT J AU Acree, CW AF Acree, CW TI Effects of V-22 blade modifications on whirl flutter and loads SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article ID STABILITY AUGMENTATION; DESIGN AB A CAMRAD II model of the V-22 Osprey tiltrotor was constructed for the purpose of analyzing the effects of blade design changes on whirl flutter. The model incorporated a dual load-path grip/yoke assembly, a swashplate coupled to the transmission case, and a drive train. A multiple-trailer free-vortex wake model was used for loads calculations. The effects of rotor design changes on whirl-mode stability were calculated for swept blades and offset tip masses. A rotor with swept tips and inboard tuning masses was examined in detail to reveal the mechanisms by which these design changes affect stability and loads. Certain combinations of design features greatly increased whirl-mode stability, with (at worst) moderate increases to loads. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Acree, CW (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 14 TC 0 Z9 0 U1 1 U2 4 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 JUL PY 2005 VL 50 IS 3 BP 269 EP 278 PG 10 WC Engineering, Aerospace SC Engineering GA 953PX UT WOS:000231092700006 ER PT J AU Stack, J Caradonna, FX Savas, O AF Stack, J Caradonna, FX Savas, O TI Flow visualizations and extended thrust time histories of rotor vortex wakes in descent SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT 4th Decennial Specialists Conference on Aeromechanics CY JAN 21-23, 2004 CL San Francisco, CA ID HELICAL VORTEX; AXIAL FLIGHT/; TIP-VORTICES; STABILITY; FILAMENT AB An experimental study was performed on a three-bladed rotor model in two water tanks. Blade pitch, rotational velocity, descent angle, and descent speed were varied to simulate a wide range of rotorcraft operating states, focusing on cases where the rotor was operating in vortex ring state. Flow visualization used flow markers injected tangentially from the blade tips to mark vortex cores, showing the development of shortwave and longwave instabilities on the helical vortices in the wake. Strain gages recorded transient loads, allowing a correlation between rotor thrust and wake development. Chord Reynolds numbers were of order 10(5). The data indicate that as the instabilities develop, adjacent vortices merge, forming thick vortex rings during descent. Periodic shedding of these rings from the wake associated with vortex ring state was observed, resulting in peak-to-peak thrust fluctuations of up to 95% of the mean that occured at regular intervals of 20-50 rotor revolutions, depending on flow parameters. C1 Univ Calif Berkeley, Berkeley, CA 94720 USA. NASA, Army Rotocraft Div, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Stack, J (reprint author), Univ Calif Berkeley, Berkeley, CA 94720 USA. NR 27 TC 5 Z9 5 U1 0 U2 0 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 JUL PY 2005 VL 50 IS 3 BP 279 EP 288 PG 10 WC Engineering, Aerospace SC Engineering GA 953PX UT WOS:000231092700007 ER PT J AU Ely, TA AF Ely, TA TI Stable constellations of frozen elliptical inclined lunar orbits SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article AB Higher altitude orbits (in the 500 to 20,000 km range) at the Moon are dominated by Earth perturbations and result in motions that do not ascribe to the standard notions of orbits dominated by nonspherical gravity effects (such as from oblateness). This fact complicates orbit design of lunar orbiter constellations that require specific and persistent coverage over a selected lunar region. Using a combination of analytical theory and numerical simulation, a technique is developed for designing a lunar constellation of three spacecraft where two spacecraft are always in view from the lunar surface for the polar regions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ely, TA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 301-125, Pasadena, CA 91109 USA. EM Todd.A.Ely@jpl.nasa.gov NR 16 TC 26 Z9 26 U1 0 U2 2 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 JUL-SEP PY 2005 VL 53 IS 3 BP 301 EP 316 PG 16 WC Engineering, Aerospace SC Engineering GA 033ZD UT WOS:000236892600004 ER PT J AU Hinkelman, LM Stevens, B Evans, KF AF Hinkelman, LM Stevens, B Evans, KF TI A large-eddy simulation study of anisotropy in fair-weather cumulus cloud fields SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID PLANETARY BOUNDARY-LAYER; INDEPENDENT PIXEL; ROLL VORTICES; WIND SHEAR; CONVECTION; RADIATION; FLUXES; REPRESENTATION; PATTERNS AB Causes of anisotropy in fair-weather cumulus cloud fields were investigated using quantitative measures of anisotropy and a large-eddy simulation (LES) model. Case six of the Global Energy and Water Cycle Experiment (GEWEX) Cloud System Study Working Group 1 was used as the standard model scenario. This case represents radiatively forced development of cumulus clouds over the southern Great Plains. Cloud formation under a variety of environmental conditions was simulated and the degree of anisotropy in the output fields was calculated as a function of spatial scale. Wind shear was found to be the single greatest factor in the development of both vertically tilted and horizontally stretched cloud structures. Other factors included mean wind speed, initial water vapor mixing ratio, and the magnitude of the surface forcing. C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90024 USA. Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. RP Hinkelman, LM (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. EM l.m.hinkelman@larc.nasa.gov RI Stevens, Bjorn/A-1757-2013; Hinkelman, Laura/L-8964-2016 OI Stevens, Bjorn/0000-0003-3795-0475; Hinkelman, Laura/0000-0001-6477-9648 NR 44 TC 13 Z9 14 U1 1 U2 4 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 JUL PY 2005 VL 62 IS 7 BP 2155 EP 2171 DI 10.1175/JAS3463.1 PN 1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 951WJ UT WOS:000230962800007 ER PT J AU Cheng, Y Canuto, VM Howard, AM AF Cheng, Y Canuto, VM Howard, AM TI Nonlocal convective PBL model based on new third- and fourth-order moments SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID ATMOSPHERIC BOUNDARY-LAYER; TURBULENCE CLOSURE-MODEL; LARGE-EDDY SIMULATION; TRANSPORT; APPROXIMATION; 2ND-MOMENT; EQUATIONS; DIFFUSION; DRIVEN; FLOWS AB The standard approach to studying the planetary boundary layer (PBL) via turbulence models begins with the first-moment equations for temperature, moisture, and mean velocity. These equations entail second-order moments that are solutions of dynamic equations, which in turn entail third-order moments, and so on. How and where to terminate (close) the moments equations has not been a generally agreed upon procedure and a variety of models differ precisely in the way they terminate the sequence. This can be viewed as a bottom-up approach. In this paper, a top-down procedure is suggested, worked out, and justified, in which a new closure model is proposed for the fourth-order moments (FOMs). The key reason for this consideration is the availability of new aircraft data that provide for the first time the z profile of several FOMs. The new FOM expressions have nonzero cumulants that the model relates to the z integrals of the third-order moments (TOMS), giving rise to a nonlocal model for the FOMs. The new FOM model is based on an analysis of the TOM equations with the aid of large-eddy simulation (LES) data, and is verified by comparison with the aircraft data. Use of the new FOMs in the equations for the TOMS yields a new TOM model, in which the TOMS are damped more realistically than in previous models. Surprisingly, the new FOMs with nonzero cumulants simplify, rather than complicate, the TOM model as compared with the quasi-normal (QN) approximation, since the resulting analytic expressions for the TOMS are considerably simpler than those of previous models and are free of algebraic singularities. The new TOMS are employed in a second-order moment (SOM) model, a numerical simulation of a convective PBL is run, and the resulting mean potential temperature T, the SOMs, and the TOMS are compared with several LES data. As a final consistency check, T, SOMs, and TOMs are substituted from the PBL run back into the FOMs, which are again compared with the aircraft data. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Math, New York, NY USA. MIT, Dept Earth Atmosphere & Planetary Sci, Cambridge, MA 02139 USA. RP Cheng, Y (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM ycheng@giss.nasa.gov NR 38 TC 28 Z9 28 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 JUL PY 2005 VL 62 IS 7 BP 2189 EP 2204 DI 10.1175/JAS3474.1 PN 1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 951WJ UT WOS:000230962800009 ER PT J AU Garrett, TJ Navarro, BC Twohy, CH Jensen, EJ Baumgardner, DG Bui, PT Gerber, H Herman, RL Heymsfield, AJ Lawson, P Minnis, P Nguyen, L Poellot, M Pope, SK Valero, FPJ Weinstock, EM AF Garrett, TJ Navarro, BC Twohy, CH Jensen, EJ Baumgardner, DG Bui, PT Gerber, H Herman, RL Heymsfield, AJ Lawson, P Minnis, P Nguyen, L Poellot, M Pope, SK Valero, FPJ Weinstock, EM TI Evolution of a Florida Cirrus Anvil SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID COUNTERFLOW VIRTUAL IMPACTOR; TROPICAL CIRRUS; ICE CRYSTALS; MICROPHYSICAL PROPERTIES; RADIATIVE-TRANSFER; MARSHALL-ISLANDS; CLOUD PROPERTIES; ARCTIC CLOUDS; TOGA COARE; NASA ER-2 AB This paper presents a detailed study of a single thunderstorm anvil cirrus cloud measured on 21 July 2002 near southern Florida during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE). NASA WB-57F and University of North Dakota Citation aircraft tracked the microphysical and radiative development of the anvil for 3 h. Measurements showed that the cloud mass that was advected downwind from the thunderstorm was separated vertically into two layers: a cirrus anvil with cloud-top temperatures of -45 degrees C lay below a second, thin tropopause cirrus (TTC) layer with the same horizontal dimensions as the anvil and temperatures near -70 degrees C. In both cloud layers, ice crystals smaller than 50 mu m across dominated the size distributions and cloud radiative properties. In the anvil, ice crystals larger than 50 mu m aggregated and precipitated while small ice crystals increasingly dominated the size distributions; as a consequence, measured ice water contents and ice crystal effective radii decreased with time. Meanwhile, the anvil thinned vertically and maintained a stratification similar to its environment. Because effective radii were small, radiative heating and cooling were concentrated in layers approximately 100 m thick at the anvil top and base. A simple analysis suggests that the anvil cirrus spread laterally because mixing in these radiatively driven layers created horizontal pressure gradients between the cloud and its stratified environment. The TTC layer also spread but, unlike the anvil, did not dissipate-perhaps because the anvil shielded the TTC from terrestrial infrared heating. Calculations of top-of-troposphere radiative forcing above the anvil and TTC showed strong cooling that tapered as the anvil evolved. C1 Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Nacl Autonoma Mexico, Mexico City 04510, DF, Mexico. Gerber Sci Inc, Reston, VA USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. SPEC Inc, Boulder, CO USA. NASA, Langley Res Ctr, Langley, VA USA. Univ N Dakota, Dept Atmospher Sci, Grand Forks, ND 58201 USA. Scripps Inst Oceanog, La Jolla, CA USA. Harvard Univ, Cambridge, MA 02138 USA. RP Garrett, TJ (reprint author), Univ Utah, Dept Meteorol, 135S 1460E,Rm 819, Salt Lake City, UT 84112 USA. EM tgarrett@met.utah.edu RI Heymsfield, Andrew/E-7340-2011; Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 47 TC 52 Z9 53 U1 0 U2 4 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 JUL PY 2005 VL 62 IS 7 BP 2352 EP 2372 DI 10.1175/JAS3495.1 PN 2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 951WK UT WOS:000230962900003 ER PT J AU Knyazikhin, Y Marshak, A Larsen, ML Wiscombe, WJ Martonchik, JV Myneni, RB AF Knyazikhin, Y Marshak, A Larsen, ML Wiscombe, WJ Martonchik, JV Myneni, RB TI Small-scale drop size variability: Impact on estimation of cloud optical properties SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MARINE STRATOCUMULUS CLOUDS; DISTRIBUTIONS AB Most cloud radiation models and conventional data processing techniques assume that the mean number of drops of a given radius is proportional to volume. The analysis of microphysical data on liquid water drop sizes shows that, for sufficiently small volumes, this proportionality breaks down; the number of cloud drops of a given radius is instead proportional to the volume raised to a drop size-dependent nonunit power. The coefficient of proportionality, a generalized drop concentration, is a function of the drop size. For abundant small drops the power is unity as assumed in the conventional approach. However, for rarer large drops, it falls increasingly below unity. This empirical fact leads to drop clustering, with the larger drops exhibiting a greater degree of clustering. The generalized drop concentration shows the mean number of drops per cluster, while the power characterizes the occurrence frequency of clusters. With a fixed total number of drops in a cloud, a decrease in frequency of clusters is accompanied by a corresponding increase in the generalized concentration. This initiates a competing process missed in the conventional models: an increase in the number of drops per cluster enhances the impact of rarer large drops on cloud radiation while a decrease in the frequency suppresses it. Because of the nonlinear relationship between the number of clustered drops and the volume, these two opposite tendencies do not necessarily compensate each other. The data analysis suggests that clustered drops likely have a stronger radiative impact compared to their unclustered counterpart; ignoring it results in underestimation of the contribution from large drops to cloud horizontal optical path. C1 Boston Univ, Dept Geog, Boston, MA 02215 USA. NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Michigan Technol Univ, Dept Phys, Houghton, MI 49931 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Knyazikhin, Y (reprint author), Boston Univ, Dept Geog, 675 Commonwealth Ave, Boston, MA 02215 USA. EM jknjazi@crsa.bu.edu RI Wiscombe, Warren/D-4665-2012; Marshak, Alexander/D-5671-2012; Myneni, Ranga/F-5129-2012 OI Wiscombe, Warren/0000-0001-6844-9849; NR 14 TC 9 Z9 9 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 JUL PY 2005 VL 62 IS 7 BP 2555 EP 2567 DI 10.1175/JAS3488.1 PN 2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 951WK UT WOS:000230962900015 ER PT J AU Pinty, B Lattanzio, A Martonchik, JV Verstraete, MM Gobron, N Taberner, M Widlowski, JL Dickinson, RE Govaerts, Y AF Pinty, B Lattanzio, A Martonchik, JV Verstraete, MM Gobron, N Taberner, M Widlowski, JL Dickinson, RE Govaerts, Y TI Coupling diffuse sky radiation and surface albedo SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID RETRIEVAL; MODEL; LAND; PRODUCTS; METEOSAT; MODIS; BRDF; MISR AB New satellite instruments have been delivering a wealth of information regarding land surface albedo. This basic quantity describes what fraction of solar radiation is reflected from the earth's surface. However, its concept and measurements have some ambiguity resulting from its dependence on the incidence angles of both the direct and diffuse solar radiation. At any time of day, a surface receives direct radiation in the direction of the sun, and diffuse radiation from the various other directions in which it may have been scattered by air molecules, aerosols, and cloud droplets. This contribution proposes a complete description of the distribution of incident radiation with angles, and the implications in terms of surface albedo are given in a mathematical form, which is suitable for climate models that require evaluating surface albedo many times. The different definitions of observed albedos are explained in terms of the coupling between surface and atmospheric scattering properties. The analytical development in this paper relates the various quantities that are retrieved from orbiting platforms to what is needed by an atmospheric model. It provides a physically simple and practical approach to evaluation of land surface albedo values at any condition of sun illumination irrespective of the current range of surface anisotropic conditions and atmospheric aerosol load. The numerical differences between the various definitions of albedo for a set of typical atmospheric and surface scattering conditions are illustrated through numerical computation. C1 EC Joint Res Ctr, IES, Global Vegetat Monitoring Unit, I-21020 Ispra, VA, Italy. Makalumedia Gmbh, Darmstadt, Germany. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. EUMETSAT, Darmstadt, Germany. RP Pinty, B (reprint author), EC Joint Res Ctr, IES, Global Vegetat Monitoring Unit, TP 440,Via E Fermi, I-21020 Ispra, VA, Italy. EM bernard.pinty@jrc.it OI Verstraete, Michel/0000-0003-0968-8721 NR 28 TC 36 Z9 37 U1 0 U2 7 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 JUL PY 2005 VL 62 IS 7 BP 2580 EP 2591 DI 10.1175/JAS3479.1 PN 2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 951WK UT WOS:000230962900017 ER PT J AU Ma, W Chen, S Fitzgerald, W Maric, D Lin, HJ O'Shaughnessy, TJ Kelly, J Liu, XH Barker, JL AF Ma, W Chen, S Fitzgerald, W Maric, D Lin, HJ O'Shaughnessy, TJ Kelly, J Liu, XH Barker, JL TI Three-dimensional collagen gel networks for neural stem cell-based neural tissue engineering SO MACROMOLECULAR SYMPOSIA LA English DT Article; Proceedings Paper CT 17th Polymer-Networks-Group Meeting CY AUG 15-19, 2004 CL Bethesda, MD SP Natl Inst Hlth, IUPAC, Natl Inst Standards & Technol DE biopolymers; bioreactor; collagen gels; matrix; neural stem cell ID CENTRAL-NERVOUS-SYSTEM; MICROGRAVITY AB Stem and progenitor cells isolated from the embryonic rat cerebral cortex were immobilized by matrix entrapment in three-dimensional (3D) Type I collagen gels, and cultured in serum-free medium containing basic fibroblast growth factor. The cells trapped within the collagen networks actively proliferated and formed clone-like aggregates. Neurons were the first differentiated cells to appear within the aggregates, followed by generation of astrocytes and oligodendrocytes. In addition, necrotic cores were developed as the aggregate diameter increased and cell viability declined significantly after 3 weeks in culture. To overcome these problems, the cell-collagen constructs were transferred to Rotary Wall Vessel bioreactors for up to 10 weeks. In the rotary culture, the collagen gels compacted 3-4 folds and a long-term growth and differentiation of neural stem and progenitor cells was dynamically maintained. Remarkably, the cell-collagen constructs formed a complex two-layered structure that superficially emulated to a certain extent the cerebral cortex of the embryonic brain in architecture and functionality. The engineered 3D tissue-like constructs displaying characteristic properties of neuronal circuits may have potential use in tissue replacement therapy for injured brain and spinal cord. C1 USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. Wyle Labs, Bethesda, MD 20892 USA. NASA, NIH, Ctr Dimens Tissue Culture 3, Bethesda, MD 20892 USA. NICHD, Lab Cellular & Mol Biophys, NICHHD, NIH, Bethesda, MD 20892 USA. NINDS, Neurophysiol Lab, NIH, Bethesda, MD 20892 USA. Uniformed Serv Univ Hlth Sci, Dept Pathol, Bethesda, MD 20814 USA. RP Ma, W (reprint author), USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. EM wma@cbmse.nrl.navy.mil NR 10 TC 7 Z9 7 U1 0 U2 10 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1022-1360 J9 MACROMOL SYMP JI Macromol. Symp. PD JUL PY 2005 VL 227 BP 327 EP 333 DI 10.1002/masy.200550933 PG 7 WC Polymer Science SC Polymer Science GA 959AX UT WOS:000231490400034 ER PT J AU Detkova, EN Soboleva, GS Pikuta, EV Pusheva, AA AF Detkova, EN Soboleva, GS Pikuta, EV Pusheva, AA TI The effect of sodium salts and pH on the hydrogenase activity of haloalkaliphilic sulfate-reducing bacteria SO MICROBIOLOGY LA English DT Article DE haloalkaliphiles; anaerobes; sulfate reducers; Desulfonatronum; Desulfonatronovibrio; hydrogenase AB Hydrogenase is the main catabolic enzyme of hydrogen-utilizing sulfate-reducing bacteria. In haloalkaliphilic sulfate reducers, hydrogenase, particularly if it is periplasmic, functions at high concentrations of Na+ ions and low concentrations of H+ ions. The hydrogenases of the newly isolated sulfate-reducing bacteria Desulfonatronum thiodistnutans, D. lacustre, and Desulfonatronovibrio hydrogenovorans exhibit different sensitivity to Na+ ions and remain active at NaCl concentrations between 0 and 4.3 M and NaHCO3 concentrations between 0 and 1.2 M. The hydrogenases of D. lacustre and D. thiodismutans remain active at pH values between 6 and 12. The optimum pH for the hydrogenase of D. thiodismutans is 9.5. The optimum pH for the cytoplasmic and periplasmic hydrogenases of D. lacustre is 10. Thus, the hydrogenases of D. thiodismutans, D. lacustre, and Dv. hydrogenovorans are tolerant to high concentrations of sodium salts and extremely tolerant to high pH values, which makes them unique objects for biochemical studies and biotechnological applications. C1 Russian Acad Sci, Winogradsky Inst Microbiol, Moscow 117312, Russia. NASA, Astrobiol Lab, Huntsville, AL 35812 USA. RP Detkova, EN (reprint author), Russian Acad Sci, Winogradsky Inst Microbiol, Pr 60 Letiya Oktyabrya 7,K 2, Moscow 117312, Russia. EM detkovkate@rambler.ru NR 20 TC 1 Z9 1 U1 1 U2 3 PU MAIK NAUKA/INTERPERIODICA PI NEW YORK PA C/O KLUWER ACADEMIC-PLENUM PUBLISHERS, 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0026-2617 J9 MICROBIOLOGY+ JI Microbiology PD JUL-AUG PY 2005 VL 74 IS 4 BP 395 EP 399 DI 10.1007/s11021-005-0079-7 PG 5 WC Microbiology SC Microbiology GA 973ZS UT WOS:000232561700003 ER PT J AU Mingo, N Broido, DA AF Mingo, N Broido, DA TI Length dependence of carbon nanotube thermal conductivity and the "problem of long waves" SO NANO LETTERS LA English DT Article ID HEAT; MODES AB We present the first calculations of finite length carbon nanotube thermal conductivity that extend from the ballistic to the diffusive regime, throughout a very wide range of lengths and temperatures. The long standing problem of vanishing scattering of the "long wavelength phonons" (Pomeranchuk, 1. J. Phys. (U.S.S.R.) 1941, 4, 259; Phys. Rev. 1941, 60, 820) manifests itself dramatically here, making the thermal conductivity diverge as the nanotube length increases. We show that the divergence disappears if 3-phonon scattering processes are considered to second or higher order. Nevertheless, for defect free nanotubes, the thermal conductivity keeps increasing up to very large lengths (10 mu m at 300 K). Defects in the nanotube are also able to remove the long wavelength divergence. C1 NASA, Ames Ctr Nanotechnol, Moffett Field, CA 94035 USA. Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. RP Mingo, N (reprint author), NASA, Ames Ctr Nanotechnol, 229-1 Moffett Field, Moffett Field, CA 94035 USA. NR 23 TC 239 Z9 247 U1 7 U2 50 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD JUL PY 2005 VL 5 IS 7 BP 1221 EP 1225 DI 10.1021/nl050714d PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 946KP UT WOS:000230571300006 PM 16178214 ER PT J AU Manohara, HM Wong, EW Schlecht, E Hunt, BD Siegel, PH AF Manohara, HM Wong, EW Schlecht, E Hunt, BD Siegel, PH TI Carbon nanotube Schottky diodes using Ti-Schottky and Pt-Ohmic contacts for high frequency applications SO NANO LETTERS LA English DT Article ID FIELD-EFFECT TRANSISTORS; ELECTRONIC-PROPERTIES; SINGLE; DETECTORS; TUBULES AB We have demonstrated Schottky diodes using semiconducting single-walled nanotubes (s-SWNTs) with titanium Schottky and platinum Ohmic contacts for high-frequency applications. The diodes are fabricated using angled evaporation of dissimilar metal contacts over an s-SWNT. The devices demonstrate rectifying behavior with large reverse bias breakdown voltages of greater than -15 V. To decrease the series resistance, multiple SWNTs are grown in parallel in a single device, and the metallic tubes are burnt-out selectively. At low biases these diodes showed ideality factors in the range of 1.5 to 1.9. Modeling of these diodes as direct detectors at room temperature at 2.5 terahertz (THz) frequency indicates noise equivalent powers (NEP) potentially comparable to that of the state-of-the-art gallium arsenide solid-state Schottky diodes, in the range of 10(-13) W/root Hz. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Manohara, HM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 31 TC 131 Z9 133 U1 8 U2 40 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD JUL PY 2005 VL 5 IS 7 BP 1469 EP 1474 DI 10.1021/nl050829h PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 946KP UT WOS:000230571300051 PM 16178259 ER PT J AU McClanahan, T Trombka, J Loew, M AF McClanahan, T Trombka, J Loew, M TI Automated spectroscopy of X-ray and gamma-ray pulse height spectra using energy space subdivision SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Workshop on Radiation Imaging Detectors CY JUL 25-29, 2004 CL Univ Glasgow, Glasgow, SCOTLAND HO Univ Glasgow DE fluorescence; gamma; X-ray; spectroscopy; elemental analysis; geochemistry AB A new model for the automated analysis of X-ray and gamma-ray multi-channel pulse height spectra is presented. The goal of the algorithm is to efficiently and accurately converge on the background and elemental factors while limiting human influence to the a priori defined knowledge of the detector characteristics. This information includes generic estimates of the continuum with defined elemental response functions. The energy space of the spectrum is subdivided and each subspace is fit independently. By considering all possible elemental line combinations within each energy subspace an optimal line combination is determined from the minimal squared error over each reconstructed elemental line combination. In this paper, we briefly review the background issues and motivations for the present research. The paper will present the algorithms and discuss related issues for elemental analysis of actual integrated spectra obtained from the Mars Odyssey Gamma-ray spectrometer. (c) 2005 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. George Washington Univ, Washington, DC 20052 USA. RP McClanahan, T (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM timothy.p.mcclanahan@nasa.gov RI McClanahan, Timothy/C-8164-2012 NR 6 TC 0 Z9 0 U1 0 U2 4 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 JUL 1 PY 2005 VL 546 IS 1-2 BP 176 EP 179 DI 10.1016/j.nima.2005.03.126 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 942ND UT WOS:000230288200033 ER PT J AU Trabert, E Beiersdorfer, P Brown, GV Terracol, S Safronova, UI AF Trabert, E Beiersdorfer, P Brown, GV Terracol, S Safronova, UI TI On the metastable level in Ni-like ions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on the Physics of Highly Charged Ions CY SEP 06-11, 2004 CL Vilnius, LITHUANIA DE X-ray spectra; atomic lifetimes; ion trapping ID X-RAY; TRAP; SPECTRA; M1; MICROCALORIMETER; SPECTROMETER; TRANSITIONS; LINES AB The lowest excited level in Ni-like ions, 3d(9)4s (3)D3, decays only via a magnetic octupole (M3) decay. We present calculated values of transition wavelengths and rates for ions with 30 <= Z <= 100. We have observed this line in Xe26+, using the Livermore EBIT-I electron beam ion trap and a microcalorimeter, as well as a high-resolution flat-field grating spectrometer. (c) 2005 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany. Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Nevada, Reno, NV 89557 USA. RP Trabert, E (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM traebert@ep3.ruhr-uni-bochum.de NR 14 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 2005 VL 235 BP 23 EP 27 DI 10.1016/j.nimb.2005.03.138 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 943EF UT WOS:000230334400005 ER PT J AU Beiersdorfer, P Chen, H Boyce, KR Brown, GV Kelley, RL Kilbourne, CA Porter, FS Kahn, SM AF Beiersdorfer, P Chen, H Boyce, KR Brown, GV Kelley, RL Kilbourne, CA Porter, FS Kahn, SM TI Laboratory simulation of cometary X-rays using a high-resolution microcalorimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on the Physics of Highly Charged Ions CY SEP 06-11, 2004 CL Vilnius, LITHUANIA DE charge exchange; X-ray lines; comets; microcalorimeter ID MAGNETIC TRAPPING MODE; BEAM ION-TRAP; CHARGED IONS; EMISSION; SPECTROMETER; COLLISIONS; EXCHANGE; IMPACT AB X-ray emission following charge exchange has been studied at the University of California Lawrence Livermore National Laboratory electron beam ion traps EBIT-I and EBIT-II using a high-resolution microcalorimeter. The measured spectra include the K-shell emission from hydrogenlike and heliumlike C, N, O, and Ne needed for simulations of cometary x-ray emission. A comparison of the spectra produced in the interaction of O8+ with N-2 and CH4 is presented that illustrates the dependence of the observed spectrum on the interaction gas. (c) 2005 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Stanford Univ, Stanford, CA 94305 USA. RP Beiersdorfer, P (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM beiersdorfer@llnl.gov RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; NR 26 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 2005 VL 235 BP 116 EP 119 DI 10.1016/j.nimb.2005.03.156 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 943EF UT WOS:000230334400023 ER PT J AU May, MJ Beiersdorfer, P Jordan, N Scofield, JH Reed, KJ Hansen, SB Fournier, KB Gu, MF Brown, GV Porter, FS Kelley, R Kilbourne, CA Boyce, KR AF May, MJ Beiersdorfer, P Jordan, N Scofield, JH Reed, KJ Hansen, SB Fournier, KB Gu, MF Brown, GV Porter, FS Kelley, R Kilbourne, CA Boyce, KR TI Measurement of electron impact collisional excitation cross sections of Ni to Ga-Like Gold SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on the Physics of Highly Charged Ions CY SEP 06-11, 2004 CL Vilnius, LITHUANIA DE electron-impact excitation cross sections; gold M-shell; microcalorimeter; EBIT ID BEAM ION-TRAP; MICROCALORIMETER; PACKAGE; PLASMA AB We are measuring the cross sections for the 3d -> 4f and 3d -> 5f excitations in Ni- to Ga-like Au in beam plasmas created in the Livermore electron beam ion trap EBIT-I. The measurements are possible by using the high-resolution broadband coverage of the Goddard Space Flight Center micro-calorimeter. The cross sections are determined from the ratio of the intensity of the collisionally excited lines to the intensity of the radiative recombination lines. The value of the excitation cross section of the 3d(3/2) -> 5f(5/2) transition in Au50+ (Cu-like) is presented and compared to distorted wave calculations. (c) 2005 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Stanford Univ, Stanford, CA 94305 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20700 USA. RP Beiersdorfer, P (reprint author), Lawrence Livermore Natl Lab, L-260, Livermore, CA 94550 USA. EM beiersdorfer@llnl.gov RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; NR 16 TC 20 Z9 24 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 2005 VL 235 BP 231 EP 234 DI 10.1016/j.nimb.2005.03.179 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 943EF UT WOS:000230334400046 ER PT J AU Tagliaferri, G Campana, S Chincarini, G Citterio, O Moretti, A Romano, P Burrows, DN Hill, JE Kennea, J Morris, DC Nousek, JA Pagani, C Wells, A Abbey, AF Beardmore, A Goad, MR Osborne, J Page, K Capalbi, M Giommi, P Perri, M Tamburelli, F Angelini, L Cusumano, G Mangano, V La Parola, V Hartner, GD AF Tagliaferri, G Campana, S Chincarini, G Citterio, O Moretti, A Romano, P Burrows, DN Hill, JE Kennea, J Morris, DC Nousek, JA Pagani, C Wells, A Abbey, AF Beardmore, A Goad, MR Osborne, J Page, K Capalbi, M Giommi, P Perri, M Tamburelli, F Angelini, L Cusumano, G Mangano, V La Parola, V Hartner, GD TI Characteristics and performance of the Swift X-Ray telescope SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA C-COLLOQUIA ON PHYSICS LA English DT Article; Proceedings Paper CT 4th Workshop on Gamma-Ray Bursts in the Afterglow Era CY OCT 18-22, 2004 CL Rome, ITALY ID MISSION AB The X-ray Telescope (XRT), on board the Swift satellite, has been built to provide: automated source detection and position with few arcsecond accuracy within 5 seconds of target acquisition; CCD spectroscopy and imaging capability (0.2-10 keV), with a detection sensitivity of 2x10(-14) erg cm(-2) s(-1) in 10(4) s; automatic adjusting of the CCD readout mode to optimize the science return as the source fades. XRT can observe GRB after-lows over several orders of magnitude in flux. The first results obtained during the in-flight performance verification phase confirm that XRT is fully compliant with the requirements and is providing excellent results. C1 INAF, Osservatorio Astron Brera, I-23807 Merate, Italy. Univ Milano Bicocca, I-20126 Milan, Italy. Penn State Univ, Davey Lab 525, University Pk, PA 16802 USA. Univ Leicester, Leicester LE1 7RH, Leics, England. ASI ASDC, I-00044 Frascati, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. INAF, IASF Palermo, I-90146 Palermo, Italy. Max Planck Inst Extraterr Phys, D-37075 Garching, Germany. RP Tagliaferri, G (reprint author), INAF, Osservatorio Astron Brera, Via Bianchi 46, I-23807 Merate, Italy. OI Campana, Sergio/0000-0001-6278-1576; giommi, paolo/0000-0002-2265-5003; Cusumano, Giancarlo/0000-0002-8151-1990; Perri, Matteo/0000-0003-3613-4409; Tagliaferri, Gianpiero/0000-0003-0121-0723 NR 8 TC 0 Z9 0 U1 0 U2 0 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1124-1896 J9 NUOVO CIMENTO C JI Nuovo Cimento Soc. Ital. Fis. C-Colloq. Phys. PD JUL-OCT PY 2005 VL 28 IS 4-5 BP 857 EP 860 DI 10.1393/ncc/i2005-10173-6 PG 4 GA 997RW UT WOS:000234266300083 ER PT J AU Hoover, AS Kippen, RM Meegan, CA Fishman, GJ Wilson, RB Wilson-Hodge, CA Kouveliotou, C Lichti, GG von Kienlin, A Diehl, R Greiner, J Schoenfelder, V Steinle, H Preece, RD Briggs, MS Paciesas, WS Bhat, PN Connaughton, V AF Hoover, AS Kippen, RM Meegan, CA Fishman, GJ Wilson, RB Wilson-Hodge, CA Kouveliotou, C Lichti, GG von Kienlin, A Diehl, R Greiner, J Schoenfelder, V Steinle, H Preece, RD Briggs, MS Paciesas, WS Bhat, PN Connaughton, V TI The GLAST burst monitor instrument response simulation system SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA C-GEOPHYSICS AND SPACE PHYSICS LA English DT Article; Proceedings Paper CT 4th Workshop on Gamma-Ray Bursts in the Afterglow Era CY OCT 18-22, 2004 CL Rome, ITALY AB The GLAST Burst Monitor (GBM) is designed to provide wide field of view observations of gamma-ray bursts from 10 keV to 25 MeV. The GRIM is composed of twelve NaI and two BGO detectors that are widely dispersed about the GLAST spacecraft. Reconstructing burst locations and energy spectra from these separated detectors requires detailed knowledge of the response to direct and scattered burst radiation. A simulation software package based on the GEANT4 Monte Carlo toolset is being developed to fulfill this requirement. We will discuss the architecture of our simulation system and evaluate the scientific capabilities of the GBM. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Natl Space Sci Technol Ctr, Huntsville, AL 35805 USA. Max Planck Inst Extraterr Phys, D-85748 Garching, Germany. Univ Alabama, Natl Space Sci Technol Ctr, Huntsville, AL 35805 USA. RP Hoover, AS (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. OI Preece, Robert/0000-0003-1626-7335 NR 3 TC 2 Z9 2 U1 0 U2 0 PU SOCIETA ITALIANA DI FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1124-1896 J9 NUOVO CIMENTO C JI Nuovo Cimento Soc. Ital. Fis. C-Geophys. Space Phys. PD JUL-OCT PY 2005 VL 28 IS 4-5 BP 797 EP 800 DI 10.1393/ncc/i2005-10156-7 PG 4 GA 997RW UT WOS:000234266300068 ER PT J AU McLean, K Fenimore, E Palmer, D Barthelmy, S Gehrels, N Krimm, H Markwardt, C Parsons, A Tueller, J Stephens, M AF McLean, K Fenimore, E Palmer, D Barthelmy, S Gehrels, N Krimm, H Markwardt, C Parsons, A Tueller, J Stephens, M TI Follow up ability for GRB observations on Swift SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA C-GEOPHYSICS AND SPACE PHYSICS LA English DT Article; Proceedings Paper CT 4th Workshop on Gamma-Ray Bursts in the Afterglow Era CY OCT 18-22, 2004 CL Rome, ITALY AB Swift is the first satellite to autonomously select its own targets and slew to them. To test the ability of the narrow field of view instruments (NFIs) to follow up gamma ray burst (GRB) triggers, we simulate a series of randomly positioned bursts. This allows us to explore haw, the follow tip observations of the NFIs will proceed. Each located burst in the simulation is followed by four hours without bursts, to allow for the NFIs to follow up the GRB triggers. We simulated 50 bursts that were triggered and located by the Burst Alert Telescope (BAT) and observed by the NFIs to probe the follow up parameter space. The discovery orbit (when the burst is first observed after the trigger) has NFI observation durations that are random in duration, while the average observation per full-orbit (the orbits after the discovery orbit) is approximately 2500 seconds, which would then take four full orbits to fulfill the autonomous observation requirement. The NFI observations can only begin after Swift has settled on the ORB's location, which takes about a hundred seconds. This average hundred seconds limits to rapid follow tip observations by the NFIs, leaving the earliest optical observations to ground-based robotic telescopes. C1 Univ Texas, Richardson, TX 75080 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP McLean, K (reprint author), Univ Texas, Richardson, TX 75080 USA. RI Barthelmy, Scott/D-2943-2012; Gehrels, Neil/D-2971-2012; Tueller, Jack/D-5334-2012; Parsons, Ann/I-6604-2012 NR 6 TC 0 Z9 0 U1 0 U2 0 PU SOCIETA ITALIANA DI FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1124-1896 J9 NUOVO CIMENTO C JI Nuovo Cimento Soc. Ital. Fis. C-Geophys. Space Phys. PD JUL-OCT PY 2005 VL 28 IS 4-5 BP 837 EP 840 DI 10.1393/ncc/i2005-10168-3 PG 4 GA 997RW UT WOS:000234266300078 ER PT J AU Longo, F Omodei, N Band, D Bonnell, JT Brigida, M Cohen-Tanugi, J Giannitrapani, R Kamae, T Norris, JP Winai, M AF Longo, F Omodei, N Band, D Bonnell, JT Brigida, M Cohen-Tanugi, J Giannitrapani, R Kamae, T Norris, JP Winai, M TI Gamma Ray Bursts and Data Challenge One: Searching GRB in one week of simulated GLAST LAT data SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA C-GEOPHYSICS AND SPACE PHYSICS LA English DT Article; Proceedings Paper CT 4th Workshop on Gamma-Ray Bursts in the Afterglow Era CY OCT 18-22, 2004 CL Rome, ITALY AB GLAST (Gamma-ray Large Area Space Telescope) is a gamma-ray astronomy mission that will be launched in mid 2007. The main instrument is the LAT (Large Area Telescope), a, pair conversion telescope with sensitivity in the range 20 MeV-300 GeV. Data, Challenge One (DC1) was the simulation of one week of observation of the entire gamma-ray sky by the LAT detector. The simulated data was similar to the real data, which allowed for the development of scientific software. In this paper we present the GRB simulations and the detection algorithms developed by the GLAST GRB and Solar Flare Science Team. C1 Univ Trieste, I-34127 Trieste, Italy. Ist Nazl Fis Nucl, Sez Trieste, Trieste, Italy. Univ Siena, I-53100 Siena, Italy. Ist Nazl Fis Nucl, Sez Pisa, Pisa, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Bari, I-70121 Bari, Italy. Ist Nazl Fis Nucl, Sez Bari, Bari, Italy. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Udine, I-33100 Udine, Italy. RP Longo, F (reprint author), Univ Trieste, I-34127 Trieste, Italy. OI Omodei, Nicola/0000-0002-5448-7577 NR 10 TC 0 Z9 0 U1 0 U2 0 PU SOCIETA ITALIANA DI FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 1124-1896 J9 NUOVO CIMENTO C JI Nuovo Cimento Soc. Ital. Fis. C-Geophys. Space Phys. PD JUL-OCT PY 2005 VL 28 IS 4-5 BP 841 EP 844 DI 10.1393/ncc/i2005-10169-2 PG 4 GA 997RW UT WOS:000234266300079 ER PT J AU Hodgson, ME Jensen, J Raber, G Tullis, J Davis, BA Thompson, G Schuckman, K AF Hodgson, ME Jensen, J Raber, G Tullis, J Davis, BA Thompson, G Schuckman, K TI An evaluation of lidar-derived elevation and terrain slope in leaf-off conditions SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID ACCURACY; MODELS AB The effects of land cover and surface slope on lidar-derived elevation data were examined for a watershed in the piedmont of North Carolina. Lidar data were collected over the study area in a winter (leaf-off) overflight. Survey-grade elevation points (1,225) for six different land cover classes were used as reference points. Root mean squared error (RMSE) for land cover classes ranged from 14.5 cm to 36.1 cm. Land cover with taller canopy vegetation exhibited the largest errors. The largest mean error (36.1 cm RMSE) was in the scrub-shrub cover class. Over the small slope range (00 to 100) in this study area, there was little evidence for an increase in elevation error with increased slopes. However, for low grass land cover, elevation errors do increase in a consistent manner with increasing slope. Slope errors increased with increasing surface slope, under-predicting true slope on surface slopes > 2 degrees. On average, the lidar-derived elevation under-predicted true elevation regardless of land cover category. The under-prediction was significant, and ranged up to -23.6 cm under pine land cover. C1 Univ S Carolina, Dept Geog, Columbia, SC 29208 USA. Univ Arkansas, Dept Geosci, Fayetteville, AR 72701 USA. Univ So Mississippi, Dept Geog, Hattiesburg, MS 39406 USA. NASA, Earth Sci Applicat Directorate, Applicat Engn Div, Earth Sci Applicat Directorate, Stennis Space Ctr, MS USA. N Carolina Geodet Survey, Raleigh, NC 27699 USA. Earthdata Technol LLC, Frederick, MD 21703 USA. RP Hodgson, ME (reprint author), Univ S Carolina, Dept Geog, Columbia, SC 29208 USA. EM hodgsonm@sc.edu; george.raber@usm.edu; jatullis@uark.edu; bruce.a.davis@nasa.gov; gary.thompson@ncmail.net; kschuckman@earthdata.com NR 23 TC 88 Z9 89 U1 2 U2 9 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD JUL PY 2005 VL 71 IS 7 BP 817 EP 823 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 941DJ UT WOS:000230194600010 ER PT J AU Sahrai, M Tajalli, H Kapale, KT Zubairy, MS AF Sahrai, M Tajalli, H Kapale, KT Zubairy, MS TI Subwavelength atom localization via amplitude and phase control of the absorption spectrum SO PHYSICAL REVIEW A LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; AUTLER-TOWNES MICROSCOPY; POSITION MEASUREMENT; SPONTANEOUS EMISSION; OPTICAL-FIELDS; QUANTUM INTERFERENCE; SINGLE-ATOM; DIFFRACTION; INTERFEROMETRY; SPECTROSCOPY AB We propose a scheme for subwavelength localization of an atom conditioned upon the absorption of a weak probe field at a particular frequency. Manipulating atom-field interaction on a certain transition by applying drive fields on nearby coupled transitions leads to interesting effects in the absorption spectrum of the weak probe field. We exploit this fact and employ a four-level system with three driving fields and a weak probe field, where one of the drive fields is a standing-wave field of a cavity. We show that the position of an atom along this standing wave is determined when probe-field absorption is measured. We find that absorption of the weak probe field at a certain frequency leads to subwavelength localization of the atom in either of the two half-wavelength regions of the cavity field by appropriate choice of the system parameters. We term this result as sub-half-wavelength localization to contrast it with the usual atom localization result of four peaks spread over one wavelength of the standing wave. We observe two localization peaks in either of the two half-wavelength regions along the cavity axis. C1 Tabriz Univ, Dept Phys, Tabriz, Iran. CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Pasadena, CA 91109 USA. Texas A&M Univ, Inst Quantum Studies, College Stn, TX 77843 USA. Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. RP Sahrai, M (reprint author), Tabriz Univ, Dept Phys, Tabriz, Iran. EM Kishor.T.Kapale@jpl.nasa.gov; zubairy@physics.tamu.edu NR 36 TC 113 Z9 116 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 2005 VL 72 IS 1 AR 013820 DI 10.1103/PhysRevA.72.013820 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 950VU UT WOS:000230887300153 ER PT J AU Broido, DA Ward, A Mingo, N AF Broido, DA Ward, A Mingo, N TI Lattice thermal conductivity of silicon from empirical interatomic potentials SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-DYNAMICS; GRUNEISEN PARAMETERS; AMORPHOUS-SILICON; DIAMOND STRUCTURE; SI; CRYSTALS; EXPANSION; ENERGY; MODEL; PHASES AB We present calculations of the lattice thermal conductivity of silicon that incorporate several commonly used empirical models of the interatomic potential. Second- and third-order force constants obtained from these potentials are used as inputs to an exact iterative solution of the inelastic phonon Boltzmann equation, which includes the anharmonic three-phonon scattering as well as isotopic defect and boundary scattering. Comparison of the calculated lattice thermal conductivity with the experiment shows that none of these potentials provides satisfactory agreement. Calculations of the mode Gruneisen parameters and the linear thermal expansion coefficient help elucidate the reasons for this. We also examine a set of parameters for one of these empirical potentials that produces improved agreement with both the measured lattice thermal conductivity and the thermal expansion data. C1 Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. NASA, Ames Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. NR 37 TC 103 Z9 104 U1 2 U2 30 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JUL PY 2005 VL 72 IS 1 AR 014308 DI 10.1103/PhysRevB.72.014308 PG 8 WC Physics, Condensed Matter SC Physics GA 950WQ UT WOS:000230889800088 ER PT J AU Brothers, EN Kudin, KN Scuseria, GE Bauschlicher, CW AF Brothers, EN Kudin, KN Scuseria, GE Bauschlicher, CW TI Transverse polarizabilities of carbon nanotubes: A Hartree-Fock and density functional study SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-ORBITAL METHODS; BAND-STRUCTURE MODULATION; BASIS-SETS; EXCHANGE; FIELD AB The transverse polarizabilities of carbon nanotubes are computed using Hartree-Fock (HF) and density functional theory (DFT). The results of these calculations have implications for nanoelectronics, specifically for the possibility of using nanotubes as shielding for nanoelectrical components, as the results do not support the proposed enhanced polarizability, and hence enhanced shielding, of nanotubes based on metallicity. The HF and DFT calculations are shown to be in close agreement, and this agreement is discussed. We find the polarizability per unit length depends on the square of the tube radius, and is not dependent on metallicity. The current calculations are consistent with tight binding calculations using four orbitals per carbon with regard to both trend and magnitude, but differ from some recent tight binding calculations performed using one orbital per carbon. The calculations detailed in this paper are the most elaborate to date, and settle contradictory reports in the literature. C1 Rice Univ, Dept Chem, Houston, TX 77005 USA. NASA, Ames Res Ctr, Ames Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Brothers, EN (reprint author), Rice Univ, Dept Chem, Mail Stop 60, Houston, TX 77005 USA. RI Kudin, Konstantin/A-7723-2008; Scuseria, Gustavo/F-6508-2011; OI Brothers, Edward/0000-0003-3709-7646 NR 20 TC 25 Z9 25 U1 3 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL PY 2005 VL 72 IS 3 AR 033402 DI 10.1103/PhysRevB.72.033402 PG 4 WC Physics, Condensed Matter SC Physics GA 950WU UT WOS:000230890200038 ER PT J AU Dietzel, D Marsaudon, S Aime, JP Nguyen, CV Couturier, G AF Dietzel, D Marsaudon, S Aime, JP Nguyen, CV Couturier, G TI Mechanical properties of a carbon nanotube fixed at a tip apex: A frequency-modulated atomic force microscopy study SO PHYSICAL REVIEW B LA English DT Article ID OSCILLATING TIP; ELASTIC-MODULUS; NANOMETER-SCALE; TAPPING-MODE; DISSIPATION; RESOLUTION; STABILITY; ENERGY; SYSTEM AB An investigation of mechanical properties of carbon nanotubes (CNTs) fixed at a tip apex was performed using a frequency modulation-atomic force microscope (FM-AFM). The FM-AFM method allows to measure conservative and nonconservative forces separately and unambiguously. The force gradient analysis provides a good understanding of the effects of the interaction between the free CNT end and the surface; the resonant frequency shifts provide information on the effective CNT spring constant, while the damping signal gives information on the sticking condition of the tube on the surface. Variation of the damping signal indicates that additional energy losses are mostly due to adhesion hysteresis. In particular, a close correlation between damping and resonant frequency shifts was observed. The whole variations show how the contact between the free CNT end and the surface modifies the elastic response of the tube and, in turn, the resonant frequency shift. Although not being quantitative, the cumulate variations of damping and resonance frequency provide a picture that is accurate enough to explain the effect for imaging and, in turn, find routes to enhance the contrast. An example is given with an image of InAs nanodots on GaAs. C1 Univ Bordeaux 1, CPMOH, F-33405 Talence, France. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Dietzel, D (reprint author), Univ Bordeaux 1, CPMOH, 351 Cours Liberat, F-33405 Talence, France. EM jp.aime@cpmoh.u-bordeaux1.fr NR 28 TC 17 Z9 17 U1 0 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL PY 2005 VL 72 IS 3 AR 035445 DI 10.1103/PhysRevB.72.035445 PG 16 WC Physics, Condensed Matter SC Physics GA 950WU UT WOS:000230890200189 ER PT J AU Lobo, RPSM LaVeigne, JD Reitze, DH Tanner, DB Barber, ZH Jacques, E Bosland, P Burns, MJ Carr, GL AF Lobo, RPSM LaVeigne, JD Reitze, DH Tanner, DB Barber, ZH Jacques, E Bosland, P Burns, MJ Carr, GL TI Photoinduced time-resolved electrodynamics of superconducting metals and alloys SO PHYSICAL REVIEW B LA English DT Article ID QUASI-PARTICLE DYNAMICS; RECOMBINATION TIME; PAIR BREAKING; THIN-FILMS; NONEQUILIBRIUM SUPERCONDUCTORS; INFRARED-SPECTROSCOPY; QUASIPARTICLES; YBA2CU3O7-DELTA; RELAXATION; LIFETIMES AB The photoexcited state in superconducting metals and alloys was studied via pump-probe spectroscopy. A pulsed Ti:sapphire laser was used to create the nonequilibrium state and the far-infrared pulses of a synchrotron storage ring, to which the laser is synchronized, measured the changes in the material optical properties. Both the time- and frequency-dependent photoinduced spectra of Pb, Nb, NbN, Nb0.5Ti0.5N, and Pb0.75Bi0.25 superconducting thin films were measured in the low-fluence regime. The time-dependent data establish the regions where the relaxation rate is dominated either by the phonon escape time (phonon bottleneck effect) or by the intrinsic quasiparticle recombination time. The photoinduced spectra measure directly the reduction of the superconducting gap due to an excess number of quasiparticles created by the short laser pulses. This gap shift allows us to establish the temperature range over which the low fluence approximation is valid. C1 Ecole Super Phys & Chim Ind Ville Paris, Lab Phys Solide, CNRS, UPR 5, F-75231 Paris, France. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. Univ Cambridge, Dept Mat Sci & Met, Cambridge CB2 3QZ, England. CEA Saclay, DAPNIA, F-91191 Gif Sur Yvette, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Lobo, RPSM (reprint author), Ecole Super Phys & Chim Ind Ville Paris, Lab Phys Solide, CNRS, UPR 5, 10 Rue Vauquelin, F-75231 Paris, France. EM lobo@espci.fr RI Burns, Michael/D-2939-2011 OI Burns, Michael/0000-0001-9804-405X NR 47 TC 19 Z9 19 U1 0 U2 9 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 JUL PY 2005 VL 72 IS 2 AR 024510 DI 10.1103/PhysBevB.72.024510 PG 10 WC Physics, Condensed Matter SC Physics GA 950WT UT WOS:000230890100129 ER PT J AU Mehrez, H Walch, S Anantram, MP AF Mehrez, H Walch, S Anantram, MP TI Electronic properties of O-2-doped DNA SO PHYSICAL REVIEW B LA English DT Article ID ELECTRICAL-CONDUCTION; MOLECULAR-ENERGIES; GAUSSIAN-1 THEORY; TRANSPORT AB Based on recent experimental transport measurements, it has been suggested that DNA electronic properties can be modified by molecular oxygen hole doping. To explore the possibility of controlling the electronic properties of DNA by oxygen doping, we have carried out ab initio electronic structure calculations of O-2-doped DNA systems. We have found that O-2 is weakly bonded to DNA with negligible charge transfer. The highest occupied molecular orbital-lowest unoccupied molecular orbital gap is much larger than the room temperature energy scale, k(B)T, making it unlikely that O-2 can dope DNA. To explain the experimental results we suggest other possible underlying mechanisms and further experiments to test their validity. C1 NASA, Ctr Nanotechnol, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, NASA Adv Supercomp Div, Moffett Field, CA 94035 USA. ELORET, Moffett Field, CA 94035 USA. UCSC, UARC, Moffett Field, CA 94035 USA. RP Mehrez, H (reprint author), NASA, Ctr Nanotechnol, Ames Res Ctr, Mail Stop 229-1, Moffett Field, CA 94035 USA. RI Walch, Susan/H-3858-2015 NR 34 TC 6 Z9 6 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JUL PY 2005 VL 72 IS 3 AR 035441 DI 10.1103/PhysRevB.72.035441 PG 6 WC Physics, Condensed Matter SC Physics GA 950WU UT WOS:000230890200185 ER PT J AU Mbonye, MR Kazanas, D AF Mbonye, MR Kazanas, D TI Nonsingular black hole model as a possible end product of gravitational collapse SO PHYSICAL REVIEW D LA English DT Article ID SPACE-TIME; SINGULARITIES; COSMOLOGY; UNIVERSE AB In this paper we present a nonsingular black hole model as a possible end-product of gravitational collapse. The depicted spacetime which is type [II,(II)], by Petrov classification, is an exact solution of the Einstein equations and contains two horizons. The equation of state p(r)(rho) in the radial direction, is a well-behaved function of the density rho(r) and smoothly reproduces vacuumlike behavior near r=0 while tending to a polytrope at larger r, low rho values. The final equilibrium configuration comprises a de Sitter-like inner core surrounded by a family of 2-surfaces Sigma of matter fields with variable equation of state. The fields are all concentrated in the vicinity of the radial center r=0. The solution depicts a spacetime that is asymptotically Schwarzschild at large r, while it becomes de Sitter-like as r -> 0. Possible physical interpretations of the macro-state of the black hole interior in the model are offered. We find that the possible state admits two equally viable interpretations, namely, either a quintessential intermediary region or a phase transition in which a two-fluid system is in both dynamic and thermodynamic equilibrium. We estimate the ratio of pure matter present to the total energy and in both cases find it to be virtually the same, being similar to 0.83. Finally, the well-behaved dependence of the density and pressure on the radial coordinate provides some insight on dealing with the information loss paradox. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20785 USA. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. RP Mbonye, MR (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 663, Greenbelt, MD 20785 USA. EM mrmsps@rit.edu NR 28 TC 13 Z9 13 U1 0 U2 1 PU AMERICAN 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 JUL PY 2005 VL 72 IS 2 AR 024016 DI 10.1103/PhysRevD.72.024016 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 950WO UT WOS:000230889600045 ER PT J AU Zlochower, Y Baker, JG Campanelli, M Lousto, CO AF Zlochower, Y Baker, JG Campanelli, M Lousto, CO TI Accurate black hole evolutions by fourth-order numerical relativity SO PHYSICAL REVIEW D LA English DT Article ID GRAVITATIONAL-WAVES; EINSTEINS EQUATIONS; MESH REFINEMENT; COLLISIONS; 1ST-ORDER; GAUGE; MASS AB We present techniques for successfully performing numerical relativity simulations of binary black holes with fourth-order accuracy. Our simulations are based on a new coding framework which currently supports higher-order finite differencing for the Baumgarte-Shapiro-Shibata-Nakamura formulation of Einstein's equations, but which is designed to be readily applicable to a broad class of formulations. We apply our techniques to a standard set of numerical relativity test problems, demonstrating the fourth-order accuracy of the solutions. Finally we apply our approach to binary black hole head-on collisions, calculating the waveforms of gravitational radiation generated and demonstrating significant improvements in waveform accuracy over second-order methods with typically achievable numerical resolution. C1 Univ Texas, Dept Phys & Astron, Brownsville, TX 78520 USA. Univ Texas, Ctr Gravitat Wave Astron, Brownsville, TX 78520 USA. NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. RP Univ Texas, Dept Phys & Astron, Brownsville, TX 78520 USA. OI Lousto, Carlos/0000-0002-6400-9640 NR 67 TC 90 Z9 90 U1 0 U2 2 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 JUL PY 2005 VL 72 IS 2 AR 024021 DI 10.1103/PhysRevD.72.024021 PG 19 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 950WO UT WOS:000230889600050 ER PT J AU Florescu, L Zhang, X AF Florescu, L Zhang, X TI Semiclassical model of stimulated Raman scattering in photonic crystals SO PHYSICAL REVIEW E LA English DT Article ID PERIODIC STRUCTURES; LASER; EDGE AB We study the stimulated Raman scattering (SRS) of light from an atomic system embedded in a photonic crystal and coherently pumped by a laser field. In our study, the electromagnetic field is treated classically and the atomic system is described quantum mechanically. Considering a decomposition of the pump and Stokes fields into the Bloch modes of the photonic crystals and using a multiscale analysis, we derive the Maxwell-Bloch equations for SRS in photonic crystals. These equations contain effective parameters that characterize the SRS gain, the nonlinear atomic response to the electromagnetic field, and the group velocity and that can be calculated in terms of the Bloch modes of the unperturbed photonic crystal. We show that if the pump laser frequency is tuned near a photonic band edge and the atomic system is carefully chosen such that the Stokes mode matches another photonic band edge, low-threshold, enhanced Raman amplification is possible. Possible physical realizations of SRS in photonic crystals are also discussed. C1 Univ Calif Berkeley, NSF, Nanoscale Sci & Engn Ctr, Berkeley, CA 94720 USA. RP Florescu, L (reprint author), CALTECH, Jet Prop Lab, NASA, 4800 Oak Grove Dr,MS 126-347, Pasadena, CA 91109 USA. RI Zhang, Xiang/F-6905-2011 NR 28 TC 13 Z9 14 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD JUL PY 2005 VL 72 IS 1 AR 016611 DI 10.1103/PhysRevE.72.016611 PN 2 PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 950VS UT WOS:000230887100089 PM 16090111 ER PT J AU Yamakov, V Saether, E Phillips, DR Glaessgen, EH AF Yamakov, V Saether, E Phillips, DR Glaessgen, EH TI Dynamic instability in intergranular fracture SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRACK-TIP; ALUMINUM; DEFORMATION; PROPAGATION; SIMULATIONS; METALS AB A molecular-dynamics model for crack propagation under steady-state conditions is used to study dynamic instabilities along a grain boundary in aluminum that occur when the crack speed approaches 1/3 of the material's Rayleigh wave speed. Instead of crack branching, as is characteristic for a crack propagating in a homogeneous environment, the instability of an intergranular crack results in a periodic series of dislocation bursts. These bursts limit the crack speed and produce velocity oscillations with a large increase in energy dissipation that increases the grain boundary toughness. C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Lockheed Martin Space Operat, Hampton, VA 23681 USA. RP Yamakov, V (reprint author), Natl Inst Aerosp, Hampton, VA 23666 USA. NR 19 TC 12 Z9 12 U1 2 U2 9 PU AMERICAN 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 JUL 1 PY 2005 VL 95 IS 1 AR 015502 DI 10.1103/PhysRevLett.95.015502 PG 4 WC Physics, Multidisciplinary SC Physics GA 942IG UT WOS:000230275500043 PM 16090629 ER PT J AU Sokolskaya, NV Adams, JH Ahn, HS Batkov, KE Bashindzhagyan, GL Wang, JZ Wefel, JP Wu, J Ganel, O Guzik, TG Gunasingha, RM Zatsepin, VI Isbert, J Kim, KC Christl, M Kouznetsov, EN Panasyuk, MI Panov, AD Seo, ES Fazely, AR Chang, J Schmidt, WKH AF Sokolskaya, NV Adams, JH Ahn, HS Batkov, KE Bashindzhagyan, GL Wang, JZ Wefel, JP Wu, J Ganel, O Guzik, TG Gunasingha, RM Zatsepin, VI Isbert, J Kim, KC Christl, M Kouznetsov, EN Panasyuk, MI Panov, AD Seo, ES Fazely, AR Chang, J Schmidt, WKH TI Albedo in the ATIC experiment: Measurements and simulations SO PHYSICS OF ATOMIC NUCLEI LA English DT Article ID SPECTRA AB We analyze the characteristics of the albedo, or the backscatter current, which constitutes a background for charge measurements in calorimetric experiments in high-energy cosmic rays. We compare the experimental data obtained in the nights of the ATIC spectrometer with the simulations performed using the GEANT 3.21 code. We discuss the influence of the backscatter on the charge resolution in the ATIC experiment. (c) 2005 Pleiades Publishing, Inc. C1 Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow 119992, Russia. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Maryland, College Pk, MD 20742 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. So Univ, Baton Rouge, LA USA. Max Planck Inst Aeron, Lindau, Germany. Chinese Acad Sci, Purple Mt Observ, Beijing 100864, Peoples R China. RP Sokolskaya, NV (reprint author), Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Vorobevy Gory, Moscow 119992, Russia. EM sok@dec1.sinp.msu.ru RI Panasyuk, Mikhail/E-2005-2012; Zatsepin, Victor/J-2287-2012; Panov, Alexander/K-3952-2012; OI Panov, Alexander/0000-0003-2290-6498; Seo, Eun-Suk/0000-0001-8682-805X NR 12 TC 2 Z9 2 U1 0 U2 2 PU MAIK NAUKA/INTERPERIODICA PUBL PI MELVILLE PA C/O AMERICAN INST PHYSICS, 2 HUNTINGTON QUANDRANGLE, STE 1NO1, MELVILLE, NY 11747-4502 USA SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD JUL PY 2005 VL 68 IS 7 BP 1176 EP 1182 DI 10.1134/1.1992573 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 952LD UT WOS:000231004100013 ER PT J AU Reuss, RH Chalamala, BR Moussessian, A Kane, MG Kumar, A Zhang, DC Rogers, JA Hatalis, M Temple, D Moddel, G Eliasson, BJ Estes, MJ Kunze, J Handy, ES Harmon, ES Salzman, DB Woodall, JM Alam, MA Murthy, JY Jacobsen, SC Olivier, M Markus, D Campbell, PM Snow, E AF Reuss, RH Chalamala, BR Moussessian, A Kane, MG Kumar, A Zhang, DC Rogers, JA Hatalis, M Temple, D Moddel, G Eliasson, BJ Estes, MJ Kunze, J Handy, ES Harmon, ES Salzman, DB Woodall, JM Alam, MA Murthy, JY Jacobsen, SC Olivier, M Markus, D Campbell, PM Snow, E TI Macroelectronics: Perspectives on technology and applications SO PROCEEDINGS OF THE IEEE LA English DT Article DE flexible electronics; large area electronics; macroelectronics; thin-film transistors (TFTs) ID THIN-FILM TRANSISTORS; ELECTRICAL-PROPERTIES; METAL FOILS; NETWORKS; CIRCUITS; SILICON; ARRAYS; INAS; GAAS AB Flexible, large area electronics-macroelectronics-using amorphous silicon, low-temperature polysilicon, or various organic and inorganic nanocrystalline semiconductor materials is beginning to show great promise. While much of the activity in macroelectronics has been display-centric, a number of applications where macroelectronics is needed to enable solutions that are otherwise not feasible are beginning to attract technical and/or commercial interest. In this paper we discuss the application drivers and the technology needs and device performance requirements to enable high performance applications to include RF systems. C1 DARPA, MTO, Arlington, VA 22203 USA. Indocel Technol, Res Triangle Pk, NC 27709 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Sarnoff, Princeton, NJ 08540 USA. Acellent Technol Inc, Sunnyvale, CA 94089 USA. Univ Illinois, Urbana, IL 61801 USA. Lehigh Univ, Bethlehem, PA 18015 USA. RTI Int, Res Triangle Pk, NC 27709 USA. Phiar Corp, Boulder, CO 80302 USA. Melles Griot ElectroOpt, Longmont, CO 80503 USA. SI2 Technol Inc, Chelmsford, MA USA. LightSpin Technol Inc, Norfolk, MA 02056 USA. LightSpin Technol Inc, Bethesda, MD 20824 USA. Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. Purdue Univ, Sch Mech Engn, W Lafayette, IN 47907 USA. Sarcos, Salt Lake City, UT 84108 USA. USN, Res Lab, Washington, DC 20375 USA. RP Reuss, RH (reprint author), DARPA, MTO, Arlington, VA 22203 USA. EM robert.reuss@darpa.mil; chalamala@indocel.net; alina.moussessian@jpl.nasa.gov; mkane@sarnoff.com; akumar@acellent.com; zhang@acellent.com; jrogers@uiuc.edu; mkh1@lehigh.edu; temple@rti.org; moddel@phiar.com; eliasson@ieee.org; mestes@carlsbad.mellesgriot.com; jkunze@si2technologies.com; chandy@si2technologies.com; harmon@lightspintech.com; salzman@lightspintech.com; woodall@ecn.purdue.edu; alam@ecn.purdue.edu; jmurthy@purdue.edu; jacobsen@sarcos.com; m.olivier@sarcos.com; d.markus@sarcos.com; campbell@bloch.nrl.navy.mil; snow@bloch.nrl.navy.mil RI Albe, Karsten/F-1139-2011; Rogers, John /L-2798-2016 NR 51 TC 234 Z9 242 U1 7 U2 65 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 JUL PY 2005 VL 93 IS 7 BP 1239 EP 1256 DI 10.1109/JPROC.2005.851237 PG 18 WC Engineering, Electrical & Electronic SC Engineering GA 944YE UT WOS:000230466300002 ER PT J AU Joslin, RD Thomas, RH Choudhari, MM AF Joslin, RD Thomas, RH Choudhari, MM TI Synergism of flow and noise control technologies SO PROGRESS IN AEROSPACE SCIENCES LA English DT Review ID TURBULENT-BOUNDARY-LAYER; LARGE-EDDY SIMULATION; DRAG REDUCTION; VORTEX GENERATORS; REYNOLDS-NUMBER; JET NOISE; PIEZOELECTRIC ACTUATORS; HYDRODYNAMIC STABILITY; COMPLIANT SURFACES; SEPARATION CONTROL AB This paper will discuss the synergism of flow and noise control technologies relevant to both air and undersea vehicles. Because many review publications specifically focus on either flow control. or noise control, this presentation will not provide an exhaustive. literature survey. Sufficient citations will highlight the effectiveness of the technologies; however, the primary goal of this paper is to outline direct and indirect linkages, counterproductive linkages, and examples with no linkages between noise and flow control technologies. Hence, woven through out the individual sections is a focus on the various forms of linkage between flow and noise control applications. Published by Elsevier Ltd. C1 Off Naval Res, Arlington, VA 22203 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Joslin, RD (reprint author), Off Naval Res, 875 N Randolph St, Arlington, VA 22203 USA. EM Ronald_Joslin@ONR.NAVY.MIL; R.H.Thomas@LARC.NASA.GOV; M.M.Choudhari@LARC.NASA.GOV RI Choudhari, Meelan/F-6080-2017 OI Choudhari, Meelan/0000-0001-9120-7362 NR 355 TC 10 Z9 13 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0376-0421 J9 PROG AEROSP SCI JI Prog. Aeosp. Sci. PD JUL PY 2005 VL 41 IS 5 BP 363 EP 417 DI 10.1016/j.paerosci.2005.07.002 PG 55 WC Engineering, Aerospace SC Engineering GA 972BZ UT WOS:000232430200002 ER PT J AU Pusey, ML Liu, ZJ Tempel, W Praissman, J Lin, DW Wang, BC Gavira, JA Ng, JD AF Pusey, ML Liu, ZJ Tempel, W Praissman, J Lin, DW Wang, BC Gavira, JA Ng, JD TI Life in the fast lane for protein crystallization and X-ray crystallography SO PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY LA English DT Review DE high-throughput crystallization; structural genomics; X-ray crystallography; counter-diffusion crystallization; Southeast Collaboratory for Structural Genomics (SECSG) ID MACROMOLECULAR CRYSTALLIZATION; STRUCTURAL GENOMICS; LIGHT-SCATTERING; CRYSTAL-GROWTH; ANOMALOUS SCATTERING; DENSITY MODIFICATION; TRIALS; AUTOMATION; SYSTEM; MODEL AB The common goal for structural genomic centers and consortiums is to decipher as quickly as possible the three-dimensional structures for a multitude of recombinant proteins derived from known genomic sequences. Since X-ray crystallography is the foremost method to acquire atomic resolution for macromolecules, the limiting step is obtaining protein crystals that can be useful of structure determination. High-throughput methods have been developed in recent years to clone, express, purify, crystallize and determine the three-dimensional structure of a protein gene product rapidly using automated devices, commercialized kits and consolidated protocols. However, the average number of protein structures obtained for most structural genomic groups has been very low compared to the total number of proteins purified. As more entire genomic sequences are obtained for different organisms from the three kingdoms of life, only the proteins that can be crystallized and whose structures can be obtained easily are studied. Consequently, an astonishing number of genomic proteins remain unexamined. In the era of high-throughput processes, traditional methods in molecular biology, protein chemistry and crystallization are eclipsed by automation and pipeline practices. The necessity for high-rate production of protein crystals and structures has prevented the usage of more intellectual strategies and creative approaches in experimental executions. Fundamental principles and personal experiences in protein chemistry and crystallization are minimally exploited only to obtain "low-hanging fruit" protein structures. We review the practical aspects of today's high-throughput manipulations and discuss the challenges in fast pace protein crystallization and tools for crystallography. Structural genomic pipelines can be improved with information gained from low-throughput tactics that may help us reach the higher-bearing fruits. Examples of recent developments in this area are reported from the efforts of the Southeast Collaboratory for Structural Genomics (SECSG). (c) 2004 Elsevier Ltd. All rights reserved. C1 Univ Alabama, Dept Sci Biol, Huntsville, AL 35899 USA. Univ Alabama, Struct Biol Lab, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Georgia, Dept Biochem & Mol Biol, Athens, GA 30602 USA. RP Univ Alabama, Dept Sci Biol, Huntsville, AL 35899 USA. EM ngj@email.uah.edu RI Liu, Zhi-Jie/A-3946-2012; Gavira, Jose/C-2491-2009; Gavira, Jose A./C-9814-2014 OI Liu, Zhi-Jie/0000-0001-7279-2893; Gavira, Jose/0000-0002-7386-6484; Gavira, Jose A./0000-0002-7386-6484 NR 82 TC 47 Z9 49 U1 1 U2 26 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6107 J9 PROG BIOPHYS MOL BIO JI Prog. Biophys. Mol. Biol. PD JUL PY 2005 VL 88 IS 3 BP 359 EP 386 DI 10.1016/j.pbiomolbio.2004.07.011 PG 28 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 911QE UT WOS:000228018600006 PM 15652250 ER PT J AU Arias, ML Sahade, J Henrichs, HF Kondo, Y AF Arias, ML Sahade, J Henrichs, HF Kondo, Y TI Looking for discrete UV absorption features in the early-type eclipsing binaries mu(1) Scorpii and AO Cassiopeiae SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID COROTATING INTERACTION REGIONS; O-TYPE STARS; STELLAR WINDS; HYDRODYNAMICAL SIMULATIONS; B-SUPERGIANTS; VARIABILITY; ULTRAVIOLET; COMPONENTS; SPECTRUM AB A search for discrete absorption components in the ultraviolet spectra of the early-type binaries mu(1) Scorpii and AO Cassiopeiae has been undertaken by analyzing material secured with the International 1 m Ultraviolet Explorer satellite during an exclusively assigned interval of nearly 50 hr. While the spectra of mu(1) Sco definitely do not show the presence of such lines, the spectra of AO Cas do confirm them and permit us to draw some conclusions about where they may be formed. C1 Natl Univ La Plata, Fac Ciencias Astron & Geofis, La Plata, Argentina. Natl Univ La Plata, Fac Ciencias Astron & Geofis, RA-1900 La Plata, Argentina. Univ Amsterdam, Inst Astron, NL-1018 WB Amsterdam, Netherlands. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Arias, ML (reprint author), Natl Univ La Plata, Fac Ciencias Astron & Geofis, Paseo Bosque S-N,B1900FWA, La Plata, Argentina. EM mlaura@fcaglp.unlp.edu.ar; sahade@fcaglp.unlp.edu.ar; huib@science.uva.nl; kondo@stars.gsfc.nasa.gov NR 26 TC 1 Z9 1 U1 0 U2 0 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 JUL PY 2005 VL 117 IS 833 BP 730 EP 740 DI 10.1086/431267 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PG UT WOS:000230084300009 ER PT J AU Makarov, VV Milman, M AF Makarov, VV Milman, M TI Accuracy and covariance analysis of global astrometry with the Space Interferometry Mission SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID TRIGONOMETRIC PARALLAXES; HIPPARCOS PARALLAXES; END AB Construction of an all- sky microarcsecond astrometric grid is an essential preliminary step toward global astrometry with the Space Interferometry Mission ( SIM). The general setup of the global astrometry problem is given, and fast, robust algorithms to solve the problem are described. The results of extensive numerical simulations are used to outline the conditions necessary to achieve the performance goal of absolute astrometric accuracy. Rigorous computation of the global covariance matrix makes it possible to correctly interpret and utilize the SIM data. We formulate and resolve the new issue of the basic performance uncertainty of a single astrometric mission. C1 CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Michelson Sci Ctr, 770 S Wilson Ave,Maild Stop 100-22, Pasadena, CA 91125 USA. EM valeri.makarov@jpl.nasa.gov OI Makarov, Valeri/0000-0003-2336-7887 NR 25 TC 10 Z9 12 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6280 EI 1538-3873 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JUL PY 2005 VL 117 IS 833 BP 757 EP 771 DI 10.1086/431367 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 939PG UT WOS:000230084300012 ER PT J AU Reynolds, CA Gelaro, R Rosmond, TE AF Reynolds, CA Gelaro, R Rosmond, TE TI A comparison of variance and total-energy singular-vectors SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE adaptive observing; forecast error; predictability; pseudo-inverse ID TRANSFORM KALMAN FILTER; TARGETED OBSERVATIONS; ADAPTIVE OBSERVATIONS; FORECAST ERRORS; FASTEX; PREDICTABILITY; PERTURBATIONS; SENSITIVITY; PREDICTION; SYSTEM AB The analysis-error variance estimates produced by the Naval Research Laboratory Atmospheric Variational Data Assimilation System are used to constrain singular vectors (SVs) at initial time (the final-time metric is total energy). These 'VAR SVs' are compared to SVs for which total energy is both the initial- and final-time metrics (TE SVs). The spatial distributions and structures of the VAR SVs and TE SVs are examined and their effectiveness in explaining forecast error is compared. Consistent with previous results, the VAR SVs have relatively larger amplitude than TE SVs in regions where analysis errors are larger (such as over oceans and polar regions). In contrast to previous results, the initial-time VAR SV energy peaks at lower altitudes than the TE SV energy, reflecting the influence of the data-assimilation-error variance estimates. Despite these significant differences, the TE and VAR SVs explain comparable amounts of forecast error in both linear and nonlinear contexts. By projecting the VAR SV pseudo-inverse perturbation onto the TE SVs, it is found that the component inside the TE-SV subspace accounts for most of the forecast-error reduction. The component outside the TE-SV subspace has very little impact on error reduction. It is noteworthy that for both the TE and VAR SVs, nonlinear pseudo-inverse forecast-corrections are better than the expected linear corrections. Both sets of SVs exhibit a relationship between singular-vector growth and forecast-error total energy, when averaged over many cases. This indicates that the SVs have some utility in predicting forecast-error variance. C1 USN, Res Lab, Monterey, CA 93943 USA. NASA, GSFC, GMAO, Greenbelt, MD 20771 USA. RP Reynolds, CA (reprint author), USN, Res Lab, 7 Grace Hopper Ave, Monterey, CA 93943 USA. EM reynolds@nrlmry.navy.mil OI Reynolds, Carolyn/0000-0003-4690-4171 NR 32 TC 5 Z9 5 U1 0 U2 0 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JUL PY 2005 VL 131 IS 609 BP 1955 EP 1973 DI 10.1256/qj.04.132 PN A PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 953BR UT WOS:000231051300008 ER PT J AU Gangopadhyay, AK Lee, GW Kelton, KF Rogers, JR Goldman, AI Robinson, DS Rathz, TJ Hyers, RW AF Gangopadhyay, AK Lee, GW Kelton, KF Rogers, JR Goldman, AI Robinson, DS Rathz, TJ Hyers, RW TI Beamline electrostatic levitator for in situ high energy x-ray diffraction studies of levitated solids and liquids SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID NONCONTACT MEASUREMENT TECHNIQUE; SURFACE-TENSION; NEUTRON-SCATTERING; UNDERCOOLED MELTS; VISCOSITY; ALLOYS; ZR; NI; TEMPERATURES; FURNACE AB Determinations of the phase formation sequence, crystal structures and the thermo-physical properties of materials at high temperatures are hampered by contamination from the sample container and environment. Containerless processing techniques, such as electrostatic (ESL), electromagnetic, aerodynamic, and acoustic levitation, are most suitable for these studies. An adaptation of ESL for in situ structural studies of a wide range of materials using high energy (30-130 keV) x rays at a synchrotron source is described here. This beamline ESL (BESL) allows the in situ determination of the atomic structures of equilibrium solid and liquid phases, undercooled liquids and time-resolved studies of solid-solid and liquid-solid phase transformations. The use of area detectors enables the rapid acquisition of complete diffraction patterns over a wide range (0.5-14 A(-1)) of reciprocal space. The wide temperature range (300-2500 K), containerless processing environment under high vacuum (10(-7)-10(-8) Torr), and fast data acquisition capability, make BESL particularly well suited for phase stability studies of high temperature solids and liquids. An additional, but important, feature of BESL is the capability for simultaneous measurements of a host of thermo-physical properties including the specific heat, enthalpy of transformation, solidus and liquidus temperatures, density, viscosity, and surface tension, all on the same sample during the structural measurements. (c) 2005 American Institute of Physics. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Ames, IA 50011 USA. Univ Alabama, Huntsville, AL 35801 USA. Univ Massachusetts, Amherst, MA 01003 USA. RP Gangopadhyay, AK (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA. EM anup@wuphys.wustl.edu RI Hyers, Robert/G-3755-2010 NR 28 TC 47 Z9 50 U1 0 U2 8 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 JUL PY 2005 VL 76 IS 7 AR 073901 DI 10.1063/1.1932447 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 944NU UT WOS:000230436600030 ER PT J AU Blommaert, JADL Cami, J Szczerba, R Barlow, MJ AF Blommaert, JADL Cami, J Szczerba, R Barlow, MJ TI Late stages of stellar evolution SO SPACE SCIENCE REVIEWS LA English DT Review DE infrared : stars; stars : AGB and post-AGB; stars : atmospheres; stars : late-type; stars : mass-loss; stars : symbiotic; stars : carbon; stars : supergiants; stars : Wolf-Rayet; Planetary Nebulae; Novae; dust; molecules ID FINE-STRUCTURE LINES; WOLF-RAYET STARS; RICH AGB STARS; CRYSTALLINE SILICATE DUST; ASYMPTOTIC GIANT BRANCH; ISO-SWS SPECTROSCOPY; SPACE-OBSERVATORY SPECTROSCOPY; BIPOLAR PROTOPLANETARY NEBULA; SHORT-WAVELENGTH SPECTROMETER; DYNAMIC-MODEL ATMOSPHERES AB A large fraction of ISO observing time was used to study the late stages of stellar evolution. Many molecular and solid state features, including crystalline silicates and the rotational lines of water vapour, were detected for the first time in the spectra of (post-)Asymptotic Giant Branch (AGB) stars. Their analysis has greatly improved our knowledge of stellar atmospheres and circumstellar environments. A surprising number of objects, particularly young planetary nebulae with Wolf-Rayet (WR) central stars, were found to exhibit emission features in their ISO spectra that are characteristic of both oxygen-rich and carbon-rich dust species, while far-IR observations of the PDR around NGC 7027 led to the first detections of the rotational line spectra of CH and CH(+). C1 Katholieke Univ Leuven, Inst Sterrenkunde, B-3001 Heverlee, Belgium. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Nicholas Copernicus Astron Ctr, PL-87100 Torun, Poland. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Blommaert, JADL (reprint author), Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200B, B-3001 Heverlee, Belgium. EM jorisb@ster.kuleuven.be RI Barlow, Michael/A-5638-2009; OI Barlow, Michael/0000-0002-3875-1171; Cami, Jan/0000-0002-2666-9234 NR 185 TC 7 Z9 7 U1 0 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUL PY 2005 VL 119 IS 1-4 BP 215 EP 243 DI 10.1007/s11214-005-8057-y PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 990FX UT WOS:000233729700010 ER PT J AU Peeters, E Martinez-Hernandez, NL Rodriguez-Fernandez, NJ Tielens, X AF Peeters, E Martinez-Hernandez, NL Rodriguez-Fernandez, NJ Tielens, X TI High excitation ISM and gas SO SPACE SCIENCE REVIEWS LA English DT Review DE IR; HII regions; galactic centre; supernova remnants; LAT(E)X ID H-II REGIONS; COMPACT HII-REGIONS; FINE-STRUCTURE LINES; DIFFUSE INTERSTELLAR-MEDIUM; AROMATIC INFRARED BANDS; PHOTON-DOMINATED REGION; S140 MOLECULAR CLOUD; MU-M; PHOTODISSOCIATION REGIONS; SUPERNOVA-REMNANTS AB An overview is given of ISO results on regions of high excitation ISM and gas, i.e. H II regions, the Galactic Centre and Supernova Remnants. IR emission due to fine-structure lines, molecular hydrogen, silicates, polycyclic aromatic hydrocarbons and dust are summarised, their diagnostic capabilities illustrated and their implications highlighted. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Observ Geneva, CH-1290 Sauverny, Switzerland. Observ Paris, LUTH, LERMA, F-75014 Paris, France. Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. RP Peeters, E (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM epeeters@mail.arc.nasa.gov NR 117 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUL PY 2005 VL 119 IS 1-4 BP 273 EP 292 DI 10.1007/s11214-005-8070-1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 990FX UT WOS:000233729700012 ER PT J AU Mandea, M Purucker, M AF Mandea, M Purucker, M TI Observing, modeling, and interpreting magnetic fields of the solid Earth SO SURVEYS IN GEOPHYSICS LA English DT Review ID GEOMAGNETIC SECULAR VARIATION; ORSTED DATA; COMPREHENSIVE MODELS; SATELLITE ALTITUDE; HARMONIC-ANALYSIS; GEOSTROPHIC FLOW; MAGSAT DATA; CORE; ANOMALIES; MANTLE AB Many Earth system processes generate magnetic fields, either primary magnetic fields or in response to other magnetic fields. The largest of these magnetic fields is due to the dynamo in the Earth's core, and can be approximated by a geocentric axial dipole that has decayed by nearly 10% during the last 150 years. This is an order of magnitude faster than its natural decay time, a reflection of the growth of patches of reverse flux at the core-mantle boundary. The velocity of the North magnetic pole reached some 40 km/yr in 2001. This velocity is the highest recorded so far in the last two centuries. The second largest magnetic field in the solid Earth is caused by induced and remanent magnetization within the crust. Controlled in part by the thermo-mechanical properties of the crust, these fields contain signatures of tectonic processes currently active, and those active in the distant past. Recent work has included an estimate of the surface heat flux under the Antarctic ice cap. In order to understand the recent changes in the Earth's magnetic field, new high-quality measurements are needed to continue those being made by Orsted (launched in 1999), CHAMP and the Orsted-2 experiment onboard SAC-C (both launched in 2000). The present paper is motivated by the advent of space surveys of the geomagnetic field, and illustrates how our way of observing, modeling, and interpreting the Earth's magnetic field has changed in recent years due to the new magnetic satellite measurements. C1 Inst Phys Globe, F-75005 Paris, France. NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Mandea, M (reprint author), Geoforschungszentrum Potsdam, D-14473 Potsdam, Germany. EM mioara@ipgp.jussieu.fr RI MANDEA, Mioara/E-4892-2012 NR 99 TC 32 Z9 33 U1 1 U2 10 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0169-3298 J9 SURV GEOPHYS JI Surv. Geophys. PD JUL PY 2005 VL 26 IS 4 BP 415 EP 459 DI 10.1007/s10712-005-3857-x PG 45 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 983QP UT WOS:000233247500001 ER PT J AU Pelligra, R Doman, G Leisman, G AF Pelligra, Ralph Doman, Glenn Leisman, Gerry TI A reassessment of the SIDS Back to Sleep Campaign SO THESCIENTIFICWORLDJOURNAL LA English DT Article DE SIDS; public health; medical research; epidemiology; public health; child health; infancy; United States ID INFANT-DEATH-SYNDROME; SUDDEN-INFANT; RISK-FACTORS; REPLACEMENT THERAPY; HEART-DISEASE; SUPINE SLEEP; POSITION; PRONE; RECOMMENDATIONS; GUIDELINES AB The Back to Sleep Campaign was initiated in 1994 to implement the American Academy of Pediatrics' (AAP) recommendation that infants be placed in the nonprone sleeping position to reduce the risk of the Sudden Infant Death Syndrome (SIDS). This paper offers a challenge to the Back to Sleep Campaign (BTSC) from two perspectives: (1) the questionable validity of SIDS mortality and risk statistics, and (2) the BTSC as human experimentation rather than as confirmed preventive therapy. The principal argument that initiated the BTSC and that continues to justify its existence is the observed parallel declines in the number of infants placed in the prone sleeping position and the number of reported SIDS deaths. We are compelled to challenge both the implied causal relationship between these observations and the SIDS mortality statistics themselves. C1 NASA, Ames Res Ctr, Stanford, CA 94305 USA. Inst Achievement Human Potential, Wyndmoor, PA 19038 USA. SUNY, Sch Engn Technol, Carrick Inst Clin Ergon Rehabil & Appl Neurosci, Farmingdale, NY 11735 USA. RP Pelligra, R (reprint author), NASA, Ames Res Ctr, Stanford, CA 94305 USA. EM Ralph.Pelligra-1@nasa.gov OI Leisman, Gerry/0000-0002-9975-7331 NR 41 TC 3 Z9 3 U1 0 U2 7 PU THESCIENTIFICWORLD LTD PI NEWBURY PA 29-34, VENTURE WEST, NEW GREENHAM PARK, NEWBURY, BERKSHIRE RG19 6HX, ENGLAND SN 1537-744X J9 THESCIENTIFICWORLDJO JI TheScientificWorldJOURNAL PD JUL PY 2005 VL 5 BP 550 EP 557 DI 10.1100/tsw.2005.71 PG 8 WC Environmental Sciences; Multidisciplinary Sciences SC Environmental Sciences & Ecology; Science & Technology - Other Topics GA 110NH UT WOS:000242385100008 PM 16075152 ER PT J AU Kaito, C Kamitsuji, K Tanaka, S Kido, O Kurumada, M Sato, T Kimura, Y Suzuki, H Saito, Y AF Kaito, C Kamitsuji, K Tanaka, S Kido, O Kurumada, M Sato, T Kimura, Y Suzuki, H Saito, Y TI Direct observation of thermal alteration of mixed film of Ge and SiO SO THIN SOLID FILMS LA English DT Article DE germanium; nanostructures; silicon oxide; transmission electron microscopy (TEM) ID PHOTOLUMINESCENCE; DIFFRACTION AB The dynamic behavior of a film produced by coevaporation of Ge-SiO was observed in situ using a transmission electron microscope. The film produced had an amorphous structure containing Si, Ge and SiO2. A characteristic change of the film was observed above 500 degrees C. Upon heating at 750 degrees C, in addition to the growth of the SiGe mixed crystal with the diamond structure, the liquidlike mixed phase of SiGe-SiO2 was also produced. The growth process of the liquidlike phase was directly observed in situ. The growth process of Ge and GeSi nanocrystallites has been elucidated by cooling the mixed film to room temperature. (c) 2004 Elsevier B.V All rights reserved. C1 Ritsumeikan Univ, Dept Nanophys Frontier Projects, Shiga 5258577, Japan. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Kyoto Inst Technol, Dept Elect & Informat Sci, Sakyo Ku, Kyoto 6068585, Japan. RP Kamitsuji, K (reprint author), Ritsumeikan Univ, Dept Nanophys Frontier Projects, Shiga 5258577, Japan. EM rp007988@se.ritsumei.ac.jp RI Kimura, Yuki/J-9635-2014 OI Kimura, Yuki/0000-0002-9218-7663 NR 11 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUL 1 PY 2005 VL 483 IS 1-2 BP 396 EP 399 DI 10.1016/j.tsf.2004.12.039 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 934BK UT WOS:000229681700064 ER PT J AU Briscoe, RJ Adkison, MD Wertheimer, A Taylor, SG AF Briscoe, RJ Adkison, MD Wertheimer, A Taylor, SG TI Biophysical factors associated with the marine survival of Auke Creek, Alaska, coho salmon SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID OREGON PRODUCTION AREA; ONCORHYNCHUS-KISUTCH; PACIFIC-SALMON; PINK SALMON; BRITISH-COLUMBIA; SOCKEYE-SALMON; INTERANNUAL VARIABILITY; SELECTIVE PREDATION; OCEAN TEMPERATURE; GORBUSCHA AB Correlation analyses and stepwise regression models were run to examine relationships between the marine survival of Auke Creek coho salmon Oncorhynchus kisutch and a number of physical and biological covariates: local sea surface temperature, local precipitation, local hatchery releases of pink salmon O. gorbuscha and chum salmon O. keta, regional and state coho and pink salmon catches, and smolt survival of three other regional coho salmon stocks. Auke Creek jack return rates and adult marine survival covaried, indicating that a significant amount of the variation in marine survival is due to conditions encountered in the first 4 to 5 months of marine life. Sea surface temperature was not significantly correlated with adult survival but was significantly associated with jack return rates. Precipitation had no relationship with marine survival. The number of locally released hatchery pink and chum salmon had the strongest correlation with marine survival (r = 0.71). Marine survival trends of coho salmon stocks within 64 km of Auke Creek closely followed Auke Creek marine survival, indicating that the factors affecting the marine survival of coho salmon are similar in localized regions of northern Southeast Alaska. Regional similarities in marine survival with Auke Creek coho salmon also extend to the larger Southeast Alaska region with respect to the analysis of commercial coho salmon catch. The specific mechanisms were not identified, but these results indicate that biological covariates were more associated with Auke Creek coho salmon marine survival than were physical covariates. C1 Univ Alaska Fairbanks, Sch Fisheries & Ocean Sci, Juneau Ctr, Juneau, AK 99801 USA. Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. RP Briscoe, RJ (reprint author), Univ Alaska Fairbanks, Sch Fisheries & Ocean Sci, Juneau Ctr, 11120 Glacier Highway, Juneau, AK 99801 USA. EM ryan_briscoe@fishgame.state.ak.us NR 45 TC 16 Z9 16 U1 1 U2 5 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD JUL PY 2005 VL 134 IS 4 BP 817 EP 828 DI 10.1577/T04-063.1 PG 12 WC Fisheries SC Fisheries GA 944FK UT WOS:000230411700003 ER PT J AU Davis, MW Schreck, CB AF Davis, MW Schreck, CB TI Responses by pacific halibut to air exposure: Lack of correspondence among plasma constituents and mortality SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID FLOUNDER PSEUDOPLEURONECTES-AMERICANUS; PLEURONECTES-PLATESSA L; DISCARD MORTALITY; SEAWATER TEMPERATURE; ONCORHYNCHUS-KISUTCH; SEVERE EXERCISE; STRESS REACTION; FRESH-WATER; COHO SALMON; SABLEFISH AB Age-1 and age-2 Pacific halibut Hippoglossus stenolepis were exposed to a range of times in air (0-60 min) and air temperatures (10 degrees C or 16 degrees C) that simulated conditions on deck after capture to test for correspondence among responses in plasma constituents and mortality. Pacific halibut mortality generally did not correspond with cortisol, glucose, sodium, and potassium since the maximum observed plasma concentrations were reached after exposure to 30 min in air, while significant mortality occurred only after exposure to 40 min in air for age-1 fish and 60 min in air for age-2 fish. Predicting mortality in discarded Pacific halibut using these plasma constituents does not appear to be feasible. Lactate concentrations corresponded with mortality in age-1 fish exposed to 16 degrees C and may be useful predictors of discard mortality under a limited set of fishing conditions. C1 Hatfield Marine Sci Ctr, Alasak Fisheries Sci Ctr, Natl Marine Fisheries Serv, Natl Ocean & Atmospher Adm, Newport, OR 97365 USA. Oregon State Univ, US Geol Survey, Dept Fisheries & Wildlife, Oregon Cooperat Fish & Wildlifev Res Unit, Corvallis, OR 97331 USA. RP Davis, MW (reprint author), Hatfield Marine Sci Ctr, Alasak Fisheries Sci Ctr, Natl Marine Fisheries Serv, Natl Ocean & Atmospher Adm, Newport, OR 97365 USA. EM michael.w.davis@noaa.gov NR 42 TC 35 Z9 35 U1 0 U2 3 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 JUL PY 2005 VL 134 IS 4 BP 991 EP 998 DI 10.1577/T04-209.1 PG 8 WC Fisheries SC Fisheries GA 944FK UT WOS:000230411700017 ER PT J AU Miyoshi, K Street, KW Vander Wal, RL Andrews, R Sayir, A AF Miyoshi, K Street, KW Vander Wal, RL Andrews, R Sayir, A TI Solid lubrication by multiwalled carbon nanotubes in air and in vacuum SO TRIBOLOGY LETTERS LA English DT Article DE multiwalled carbon nanotube; friction; solid lubrication; durability; vacuum; atmosphere AB Aligned and dispersed multiwalled carbon nanotubes (MWNTs) were evaluated for solid lubrication applications. Results obtained from unidirectional sliding friction experiments indicate that MWNTs have superior friction properties and sustainability in air and vacuum. Based on analyses of wear surfaces, transfer films, wear debris, and microstructures, the lubrication mechanism of the MWNTs is discussed. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. Univ Kentucky, Lexington, KY 40506 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. RP Miyoshi, K (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Kazuhisa.Miyoshi-1@nasa.gov NR 12 TC 38 Z9 40 U1 0 U2 6 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PD JUL PY 2005 VL 19 IS 3 BP 191 EP 201 DI 10.1007/s11249-005-6146-4 PG 11 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 948LM UT WOS:000230717300005 ER PT J AU DellaCorte, C AF DellaCorte, C TI Disruptions in status quo often lead to improvements SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM cdellacorte@stle.org NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 TRIBOL LUBR TECHNOL JI Tribol. Lubr. Technol. PD JUL PY 2005 VL 61 IS 7 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 945TM UT WOS:000230525100002 ER PT J AU Dempsey, PJ Certo, JM Morales, W AF Dempsey, PJ Certo, JM Morales, W TI Current status of hybrid bearing damage detection SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 60th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 15-19, 2005 CL Las Vegas, NV SP Soc Tribol & Lubricat Engineers DE condition monitoring; wear particles; ceramic bearings AB Advances in material development and processing have led to the introduction of ceramic hybrid bearings for many applications. The introduction of silicon nitride hybrid bearings into the high-pressure oxidizer turbopump on the space shuttle main engine led NASA to solve a highly persistent and troublesome bearing problem. Hybrid bearings consist of ceramic balls and steel races. The majority of hybrid bearings utilize Si3N4 balls. The aerospace industry is currently studying the use of hybrid bearings and, naturally, the failure modes of these bearings become an issue in light of the limited data available. In today's turbine engines and helicopter transmissions, the health of the bearings is detected by the properties of the debris found in the lubrication line when damage begins to occur. Current oil debris sensor technology relies on the magnetic properties of the debris to detect damage. Because the ceramic rolling elements of hybrid bearings have no metallic properties, a new sensing system must be developed to indicate the system health if ceramic components are to be safely implemented in aerospace applications. The ceramic oil debris sensor must be capable of detecting ceramic and metallic component damage with sufficient reliability and forewarning to prevent a catastrophic failure. The objective of this research is to provide a background summary on what is currently known about hybrid bearing failure modes and to report preliminary results on the detection of silicon nitride debris in oil using a commercial particle counter. C1 NASA, Glenn Res Ctr, USA Res Lab, Cleveland, OH 44135 USA. RP Dempsey, PJ (reprint author), NASA, Glenn Res Ctr, USA Res Lab, Cleveland, OH 44135 USA. NR 21 TC 1 Z9 1 U1 1 U2 1 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD JUL-SEP PY 2005 VL 48 IS 3 BP 370 EP 376 DI 10.1080/05698190591008568 PG 7 WC Engineering, Mechanical SC Engineering GA 965EG UT WOS:000231932400016 ER PT J AU Zaretsky, EV Vlcek, BL Hendricks, RC AF Zaretsky, EV Vlcek, BL Hendricks, RC TI Effect of silicon nitride balls and rollers on rolling bearing life SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 60th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 15-19, 2005 CL Las Vegas, NV SP Soc Tribol & Lubricat Engineers DE rolling-element bearings; bearing life prediction; hybrid rolling bearings; silicon nitride rolling elements ID TECHNOLOGY AB Three decades have passed since the introduction of silicon nitride rollers and balls into conventional rolling-element bearings. For a given applied load, the contact (Hertz) stress in a hybrid bearing will be higher than that of an all-steel rolling-element bearing. The silicon nitride rolling-element life as well as the lives of the steel races were used to determine the resultant bearing life of both hybrid and all-steel bearings. Life factors were determined and reported for hybrid bearings. Under nominal operating speeds, the resultant calculated lives of the deep- groove, angular-contact, and cylindrical roller hybrid bearings with races made of post-1960 bearing steel increased by factors of 3.7., 3.2 and 5.5, respectively, from those calculated using the Lundberg-Palmgren equations. An all-steel bearing under the same load will have a longer life than the equivalent hybrid bearing under the same conditions. Under these conditions, hybrid bearings are predicted to have a lower fatigue life than all-steel bearings by 58% for deep-groove bearings, 41% for angular-contact bearings, and 28% for cylindrical roller bearings. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Georgia So Univ, Statesboro, GA 30460 USA. RP Zaretsky, EV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 38 TC 4 Z9 5 U1 0 U2 6 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD JUL-SEP PY 2005 VL 48 IS 3 BP 425 EP 435 DI 10.1080/05698190500225011 PG 11 WC Engineering, Mechanical SC Engineering GA 965EG UT WOS:000231932400021 ER PT J AU Vander Wal, RL Miyoshi, K Street, KW Tomasek, AJ Peng, H Liu, Y Margrave, JL Khabashesku, VN AF Vander Wal, RL Miyoshi, K Street, KW Tomasek, AJ Peng, H Liu, Y Margrave, JL Khabashesku, VN TI Friction properties of surface-fluorinated carbon nanotubes SO WEAR LA English DT Article; Proceedings Paper CT 15th International Conference on Wear of Materials CY APR 24-28, 2005 CL San Diego, CA DE friction; carbon nanotubes; fluorination; fluoronanotubes ID NANOPARTICLES AB Surface modification of the tubular or sphere-shaped carbon nanoparticles through chemical treatment, e.g., fluorination, is expected to significantly affect their friction properties. In this study, a direct fluorination of the graphene-built tubular (single-walled carbon nanotubes) structures has been carried out to obtain a series of fluorinated nanotubes (fluoronanotubes) with variable CnF (n = 2-20) stoichiometries. The friction coefficients for fluoronanotubes, as well as pristine and chemically cut nanotubes, were found to reach values as low as 0.002-0.07, according to evaluation tests run in contact with sapphire in air of about 40% relative humidity on a ball-on-disk tribometer which provided an unidirectional sliding friction motion. These preliminary results demonstrate ultra-low friction properties and show a promise in applications of surface modified nanocarbons a, a solid lubricant. (c) 2005 Elsevier B.V. All rights reserved. C1 Rice Univ, Dept Chem, Houston, TX 77005 USA. Rice Univ, Ctr Nanoscale Sci & Technol, Houston, TX 77005 USA. NASA Glenn Res Ctr, Cleveland, OH USA. NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH USA. RP Khabashesku, VN (reprint author), Rice Univ, Dept Chem, 6100 Main St, Houston, TX 77005 USA. EM khval@rice.edu NR 21 TC 30 Z9 30 U1 2 U2 16 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUL-AUG PY 2005 VL 259 IS 1-6 SI SI BP 738 EP 743 DI 10.1016/j.wear.2005.02.082 PN 1 PG 6 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 943EJ UT WOS:000230334800092 ER PT J AU Bauschlicher, CW AF Bauschlicher, CW TI Time-dependent density functional theory for polycyclic aromatic hydrocarbon anions: What is the best approach SO CHEMICAL PHYSICS LETTERS LA English DT Article ID MOLECULES; ABSORPTION; EXCHANGE; SPECTRA; MODEL AB The electronic spectra of a variety of large polycyclic aromatic hydrocarbon (PAH) anions are required to assess their importance in the interstellar medium. Using the 6-31G** basis set with a set of diffuse p pi functions on the carbon atoms removes all of the unwanted sigma* solutions found using the 6-31++G** basis set. The unwanted pi* solutions can be removed in the normal way, however, for the PAH anions, it appears that using only the 6-31G** basis set offers a cost effective way of determining the spectra of astrophysical interest. A comparison of the computed and experimental results supports this suggestion. Published by Elsevier B.V. C1 NASA Ames Res Ctr, Space Technol Div, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Bauschlicher, CW (reprint author), NASA Ames Res Ctr, Space Technol Div, Ctr Nanotechnol, Mail Stop 230-3, Moffett Field, CA 94035 USA. EM charles.w.bauschlicher@nasa.gov NR 15 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 30 PY 2005 VL 409 IS 4-6 BP 235 EP 239 DI 10.1016/j.cplett.2005.05.031 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 941NL UT WOS:000230221400016 ER PT J AU Gustafson, LL Stoskopf, MK Showers, W Cope, G Eads, C Linnehan, R Kwak, TJ Andersen, B Levine, JF AF Gustafson, LL Stoskopf, MK Showers, W Cope, G Eads, C Linnehan, R Kwak, TJ Andersen, B Levine, JF TI Reference ranges for hemolymph chemistries from Elliptio complanata of North Carolina SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE Elliptio complanata; hemolymph; hematology; reference ranges ID FRESH-WATER BIVALVE; ANODONTA-ANATINA; ACID-BASE; GLUCOSE-CONCENTRATIONS; GLYCOGEN-CONTENT; BODY-FLUIDS; UNIONIDAE; STRESS; PARAMETERS; RECOVERY AB Hemolymph chemistries may be useful nonlethal measures of bivalve health. The prognostic value of hemolymph, however, depends on a comparison of chemistry results to reference ranges from healthy individuals. Currently, knowledge of expected hemolymph values in healthy and unhealthy freshwater mussels is extremely limited. The purpose of this study was to develop a set of reference ranges for clinical evaluation of hemolymph from a freshwater mussel species common to southeastern USA. We collected hemolymph from 380 Elliptio complanata from 19 apparently healthy populations from northwest of Raleigh, North Carolina, during May through July 2001. We present reference ranges for hemolymph parameters ammonia, glucose, calcium, magnesium, phosphorus, aspartate aminotransferase (AST), bicarbonate, protein and cell count, and for tissue glycogen. We compare the subpopulations of mussels from regions with an agricultural riparian buffer to those surrounded predominantly by forested lands. We further present correlations noted between hemolymph chemistries and physical or physiologic parameters. The only statistically significant differences between populations contiguous to agricultural and forested lands were in hemolymph calcium and glucose concentrations. Other statistically significant correlations identified were between gravidity and hemolymph protein concentration and tissue glycogen content, as well as between gravidity and parasite burden, and between shell length and hemolymph glucose, AST, calcium and bicarbonate concentrations. The results of this study will aid the interpretation of health measures from populations of E. complanata of similar geographic and seasonal origin. C1 N Carolina State Univ, Coll Vet Med, Dept Clin Sci, Raleigh, NC 27606 USA. N Carolina State Univ, Coll Agr & Life Sci, Dept Environm & Mol Toxicol, Raleigh, NC 27695 USA. N Carolina State Univ, Coll Phys & Math Sci, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. N Carolina State Univ, US Geol Survey, N Carolina Cooperat Fish & Wildlife Res Unit, Raleigh, NC 27695 USA. N Carolina State Univ, Dept Zool, Raleigh, NC 27695 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Levine, JF (reprint author), N Carolina State Univ, Coll Vet Med, Dept Clin Sci, Box 8401, Raleigh, NC 27606 USA. EM jay_levine@ncsu.edu NR 33 TC 20 Z9 20 U1 0 U2 6 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0177-5103 J9 DIS AQUAT ORGAN JI Dis. Aquat. Org. PD JUN 30 PY 2005 VL 65 IS 2 BP 167 EP 176 DI 10.3354/dao065167 PG 10 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 966CJ UT WOS:000231996900010 PM 16060270 ER PT J AU Raschke, E Ohmura, A Rossow, WB Carlson, BE Zhang, YC Stubenrauch, C Kottek, M Wild, M AF Raschke, E Ohmura, A Rossow, WB Carlson, BE Zhang, YC Stubenrauch, C Kottek, M Wild, M TI Cloud effects on the radiation budget based on ISCCP data (1991 to 1995) SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE climate; planetary radiation budget; satellites; cloudsclimate; planetary radiation budget; satellites; clouds ID CLIMATOLOGY-PROJECT ISCCP; SATELLITE SOUNDERS 3I; SOLAR-RADIATION; IMAGERS ISCCP; DATA SETS; SURFACE; ATMOSPHERE; ENERGY; ABSORPTION; FLUXES AB Consistent and validated data sets of satellite-borne radiances and of a large variety of products describing the characteristics of terrestrial cloud and radiation fields have been produced within the International Satellite Cloud Climatology Project (ISCCP) covering the years 1983 through to 2003. A subset (annual and seasonal averages of the 5 year period 1991 to 1995) is used in this paper to discuss in greater detail the effect of clouds on the radiation fields at the upper and lower boundary of the atmosphere and in particular on the loss and gain (vertical divergence) of radiant energy by the atmosphere itself. Although this subset covers the effects of the Pinatubo eruption (June 1991) and of the strong El Nino event in 1992-93, which indeed caused 'anomalies in the average aerosol and cloud fields in the tropics and subtropics'. However, our regional averages of the radiation budget at the top of the atmosphere and at ground over a period of 5 years should be within 2-5 W m(-2) of longer term averages. We find very interesting spatial patterns in the global distributions of all quantities, which can be explained in part by various cloud field characteristics and by the continental surface characteristics. Most are known from similar studies with radiation budget measurements. Possibly for the first time, we show global fields of the vertical flux divergence of solar and terrestrial radiation within the atmosphere and of the effects of clouds. Both polar regions, various portions of China and the areas of persistent subtropical maritime stratocumulus fields over the Pacific and Atlantic Oceans and of cloud fields associated with the intertropical convergence zone (ITCZ) offer specific features for further analyses. This ISCCP data set seems to underestimate the absorption of solar radiation in the tropical and subtropical atmosphere by about 10 to 20 W m(-2). There is a disagreement of about 30 W m-2 in global averages of the gain and loss of solar and terrestrial radiation in the atmosphere between this and two other independent data sets, which needs thorough investigation, since such data are required to validate the radiation budgets within circulation and climate models and for other climate Studies. Such an assessment of radiation budget data is now under way within the auspices of the World Climate Research Programme. Copyright (c) 2005 Royal Meteorological Society. C1 Univ Hamburg, Inst Meteorol, D-20146 Hamburg, Germany. ETH, Inst Atmospher & Klima, Zurich, Switzerland. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Math, New York, NY USA. Ecole Polytech, Lab Meteorol Dynam, Palaiseau, France. Univ Vienna, Dept Natt Wissensch, Vienna, Austria. RP Univ Hamburg, Inst Meteorol, Bundesstr 55, D-20146 Hamburg, Germany. EM raschke@dkrz.de RI Carlson, Barbara/D-8319-2012; Wild, Martin/J-8977-2012; Rossow, William/F-3138-2015 NR 48 TC 31 Z9 36 U1 2 U2 15 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0899-8418 EI 1097-0088 J9 INT J CLIMATOL JI Int. J. Climatol. PD JUN 30 PY 2005 VL 25 IS 8 BP 1103 EP 1125 DI 10.1002/joc.1157 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 943BS UT WOS:000230327400005 ER PT J AU Fiore, AM Horowitz, LW Purves, DW Levy, H Evans, MJ Wang, YX Li, QB Yantosca, RM AF Fiore, AM Horowitz, LW Purves, DW Levy, H Evans, MJ Wang, YX Li, QB Yantosca, RM TI Evaluating the contribution of changes in isoprene emissions to surface ozone trends over the eastern United States SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTH-AMERICA; AIR-QUALITY; TROPOSPHERIC OZONE; GLOBAL SIMULATION; REACTIVE NITROGEN; RURAL OZONE; MODEL; HYDROCARBONS; VARIABILITY; SENSITIVITY AB Reducing surface ozone ( O-3) to concentrations in compliance with the national air quality standard has proven to be challenging, despite tighter controls on O-3 precursor emissions over the past few decades. New evidence indicates that isoprene emissions changed considerably from the mid-1980s to the mid-1990s owing to land-use changes in the eastern United States ( Purves et al., 2004). Over this period, U. S. anthropogenic VOC ( AVOC) emissions decreased substantially. Here we apply two chemical transport models ( GEOS- CHEM and MOZART-2) to test the hypothesis, put forth by Purves et al. ( 2004), that the absence of decreasing O-3 trends over much of the eastern United States may reflect a balance between increases in isoprene emissions and decreases in AVOC emissions. We find little evidence for this hypothesis; over most of the domain, mean July afternoon ( 1300 - 1700 local time) surface O-3 is more responsive ( ranging from - 9 to + 7 ppbv) to the reported changes in anthropogenic NOx emissions than to the concurrent isoprene ( - 2 to + 2 ppbv) or AVOC ( - 2 to 0 ppbv) emission changes. The estimated magnitude of the O-3 response to anthropogenic NOx emission changes, however, depends on the base isoprene emission inventory used in the model. The combined effect of the reported changes in eastern U. S. anthropogenic plus biogenic emissions is insufficient to explain observed changes in mean July afternoon surface O-3 concentrations, suggesting a possible role for decadal changes in meteorology, hemispheric background O-3, or subgrid-scale chemistry. We demonstrate that two major uncertainties, the base isoprene emission inventory and the fate of isoprene nitrates ( which influence surface O-3 in the model by - 15 to + 4 and + 4 to + 12 ppbv, respectively), preclude a well-constrained quantification of the present-day contribution of biogenic or anthropogenic emissions to surface O-3 concentrations, particularly in the high-isoprene-emitting southeastern United States. Better constraints on isoprene emissions and chemistry are needed to quantitatively address the role of isoprene in eastern U. S. air quality. C1 NOAA, GFDL, Princeton, NJ USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA. Princeton Univ, Dept Ecol & Evolutionary Biol, Princeton, NJ 08544 USA. Univ Leeds, Sch Environm, Leeds LS2 9JT, W Yorkshire, England. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91125 USA. RP Fiore, AM (reprint author), NOAA, GFDL, Princeton, NJ USA. EM arlene.fiore@noaa.gov; larry.horowitz@noaa.gov; dpurves@princeton.edu; hiram.levy@noaa.gov; mat@env.leeds.ac.uk; yxw@io.harvard.edu; qinbin.li@jpl.nasa.gov; bmy@io.harvard.edu RI Evans, Mathew/A-3886-2012; Wang, Yuxuan/C-6902-2014; Horowitz, Larry/D-8048-2014; Yantosca, Robert/F-7920-2014; Chem, GEOS/C-5595-2014 OI Evans, Mathew/0000-0003-4775-032X; Wang, Yuxuan/0000-0002-1649-6974; Horowitz, Larry/0000-0002-5886-3314; Yantosca, Robert/0000-0003-3781-1870; NR 61 TC 97 Z9 97 U1 2 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 30 PY 2005 VL 110 IS D12 AR D12303 DI 10.1029/2004JD005485 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 945DH UT WOS:000230481500002 ER PT J AU Nelson, R Keller, C Ratnaswamy, M AF Nelson, R Keller, C Ratnaswamy, M TI Locating and estimating the extent of Delmarva fox squirrel habitat using an airborne LiDAR profiler SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE habitat mapping; profiling LiDAR; airborne laser ID LASER SCANNER DATA; PATCH ISOLATION METRICS; QUANTILE ESTIMATORS; FOREST INVENTORY; TREE HEIGHT; ALTIMETER; BIOMASS; LANDSCAPES; VEGETATION; SYSTEM AB Two thousand five hundred thirty-nine kilometers of airborne laser profiling and videography data were acquired over the state of Delaware during the summer of 2000. The laser ranging measurements and video from approximately one-half of that data set (1304 km) were analyzed to identify and locate forested sites that might potentially support populations of Delmarva fox squirrel (DFS, Sciurus niger cinereus). The DFS is an endangered species previously endemic to tall, dense, mature forests with open understories on the Eastern Shore of the Chesapeake Bay. The airborne LiDAR employed in this study can measure forest canopy height and canopy closure, but cannot measure or infer understory canopy conditions. This airborne LiDAR profiler, then, must be viewed as a tool that identifies and locates potential, not actual, habitat. Fifty-three potentially suitable DFS sites were identified in the 1304 km of flight transect data. Each of the 53 sites met the following criteria according to the LiDAR and video record: (1) at least 120 in of contiguous forest;, (2) an average canopy height > 20 m; (3) an average canopy closure of > 80%; and (4) no roofs, impervious surface (e.g., asphalt, concrete), and/or open water anywhere along the 120 m length of the laser segment. Thirty-two of the 53 sites were visited on the ground and measurements taken for a DFS habitat suitability model. Seventy-eight percent of the sites (25 of 32) were judged by the model to be suited to supporting a DFS population. All of the LiDAR flight data, 2539 km, were analyzed to estimate county and statewide forest area in different height/canopy closure classes. Approximately 3.3% of Delaware (17,137 ha) supports forest over 20 in tall with crown closures exceeding 80%; the corresponding county percentages are Newcastle County-6.1% (6823 ha), Kent County-2.2% (3431 ha), and Sussex County-2.7% (6883 ha). Estimates of average within-patch crossing distance and average between-patch distances are reported, by county, and for the state. Study results indicate that: 1) systematic airborne LiDAR data can be used to screen extensive areas to locate potential DFS habitat; 2) 78% of sites meeting certain minimum length, height, and canopy closure criteria will support DFS populations, according to a habitat suitability model; 3) airborne LiDAR can be used to calculate county and state acreage estimates of potential habitat, and 4) the linear transect data can be used to calculate patch statistics. The authors suggest that the systematic county and state flight lines can be revisited at intervals to monitor changes to the areal extent of potential habitat over time. (c) 2005 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. US Fish & Wildlife Serv, Threatened & Endangered Species Program, Chesapeake Bay Fiel Off, Annapolis, MD 21401 USA. RP Nelson, R (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 614-4, Greenbelt, MD 20771 USA. EM Ross.F.Nelson@nasa.gov; Cherry_Keller@fws.gov; Mary_Ratnaswamy@fws.gov RI Nelson, Ross/H-8266-2014 NR 42 TC 48 Z9 49 U1 3 U2 23 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 JUN 30 PY 2005 VL 96 IS 3-4 BP 292 EP 301 DI 10.1016/j.rse.2005.02.012 PG 10 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 948NG UT WOS:000230722000002 ER PT J AU Hyde, P Dubayah, R Peterson, B Blair, JB Hofton, M Hunsaker, C Knox, R Walker, W AF Hyde, P Dubayah, R Peterson, B Blair, JB Hofton, M Hunsaker, C Knox, R Walker, W TI Mapping forest structure for wildlife habitat analysis using waveform lidar: Validation of montane ecosystems SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE lidar; LIDAR; LVIS; laser altimetry; canopy; structure; height; cover; biomass ID LARGE-FOOTPRINT LIDAR; AIRBORNE LASER DATA; CANOPY STRUCTURE; TROPICAL FOREST; RAIN-FOREST; VEGETATION; BIOMASS; TOPOGRAPHY AB Consistent and accurate measurements of forest structure at the landscape scale are required by forest ecologists and managers for a variety of applications. Lidar remote sensing has proven to be a valuable tool for measuring these attributes in many ecosystems, including tropical, boreal, and mid-latitude forests. However, there have been few studies in montane forests. Here, we examine the ability of a large footprint lidar system to retrieve forest structural attributes in the highly variable terrain and canopy conditions of the Sierra Nevada mountains in California. Specifically, we examined the impact of slope, elevation, aspect, canopy cover, crown shape, and the spatial arrangement of canopy-forming trees on the accuracy of a large footprint lidar system in retrieving canopy height, canopy cover, and biomass. We found good agreement between field and lidar measurements of height, cover, and biomass at the footprint level, and canopy height and biomass at the stand level. Differences between field and lidar measurements are mainly attributable to the spatial configuration of canopy elements and are less sensitive to topography, crown shape, or canopy cover. The accuracy of canopy cover retrieval was highly sensitive to estimates of ground cover reflectivity and to ground sampling density. The accuracy of biomass retrieval was also good, and comparable to previous efforts in other biomes. (c) 2005 Elsevier Inc. All lights reserved. C1 Univ Maryland, Dept Geog, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MA USA. US Forest Serv, Dept Agr, Fresno, CA USA. Univ Michigan, Dept Elect & Comp Engn, Ann Arbor, MI 48109 USA. RP Hyde, P (reprint author), Univ Maryland, Dept Geog, College Pk, MD 20742 USA. EM phyde@geog.umd.edu RI Knox, Robert/E-9657-2011; Blair, James/D-3881-2013; Beckley, Matthew/D-4547-2013 NR 22 TC 124 Z9 130 U1 5 U2 53 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 JUN 30 PY 2005 VL 96 IS 3-4 BP 427 EP 437 DI 10.1016/j.rse.2005.03.005 PG 11 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 948NG UT WOS:000230722000012 ER PT J AU Chuang, WH Fettig, RK Ghodssi, R AF Chuang, WH Fettig, RK Ghodssi, R TI An electrostatic actuator for fatigue testing of low-stress LPCVD silicon nitride thin films SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article DE silicon nitride; fatigue; electrostatic actuator; MEMS ID HIGH-CYCLE FATIGUE; POLYCRYSTALLINE SILICON; MICROELECTROMECHANICAL FILTERS AB An electrostatic actuator and mechanical-amplifier (MA) device has been designed and fabricated to study fatigue properties of low-stress LPCVD silicon nitride thin films. The device consists of two resonators connected serially with a common torsion bar. When pumping electrostatic energy into the first resonator, the energy is transferred to the second resonator via the common torsion bar. The mechanical movement of the second resonator is thus amplified, introducing high stress levels (up to 7.7 GPa) when actuated at its first resonant mode. All devices were tested inside a focused-ion-beam (FIB) system with pressure of 10(-6) Torr at room temperature (23 +/- 1 degrees C), and the test duration ranged from 5 s to 8.5 h, 10(5) to 10(9) cycles, respectively. An ANSYS finite-element-analysis (FEA) model was built to determine the maximum operating stress of the devices. From the experiment, no failure of low-stress LPCVD silicon nitride thin films has been found even up to 109 cycles when testing at stress amplitude below 5.8 GPa with a load ratio of 0.03. The presented device design and experimental technique can be used to characterize fatigue properties of different microelectromechanical systems (MEMS) materials, and the test results are utilized in the design of microshutter arrays, programmable field selectors in the NASA James Webb Space Telescopes (JWST). (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Maryland, MEMS Sensors & Actuators Lab, Dept Elect & Comp Engn, College Pk, MD 20742 USA. Univ Maryland, Syst Res Inst, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ghodssi, R (reprint author), Univ Maryland, MEMS Sensors & Actuators Lab, Dept Elect & Comp Engn, AV Williams Bldg,Room 1357, College Pk, MD 20742 USA. EM ghodssi@eng.umd.edu NR 21 TC 12 Z9 14 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-4247 J9 SENSOR ACTUAT A-PHYS JI Sens. Actuator A-Phys. PD JUN 30 PY 2005 VL 121 IS 2 BP 557 EP 565 DI 10.1016/j.sna.2005.03.026 PG 9 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 934TK UT WOS:000229731300035 ER PT J AU Lange, D Storment, CW Conley, CA Kovacs, GTA AF Lange, D Storment, CW Conley, CA Kovacs, GTA TI A microfluidic shadow imaging system for the study of the nematode Caenorhabditis elegans in space SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE microfluidics; nematode; Caenorhabditis elegans; shadow imaging; video signal processing; space biology ID CHEMICALLY-DEFINED MEDIUM; HYPERGRAVITY; MICROGRAVITY; THERMOTAXIS; LONGEVITY; RADIATION AB This article reports on a miniaturized shadow imaging device for the investigation of the behavioral effects of spaceflight on the nematode Caenorhabditis elegans, a widely used model organism for the experimental study of genetics, development. radiobiology, as well as behavior and aging. Severe volume and power constraints for the design of satellite payloads indicate the need to miniaturize of space biology experiments and measurement systems. To address this issue. an integrated shadow imager has been developed, It consists of a polycarbonate microculture chamber with a volume of 4 μ L that supports cultures of C elegans worms in liquid media. Gas exchange is enabled through a gas-permeable membrane forming the top of the chamber. Shadow images are acquired with it CMOS video camera chip attached to the bottom of the microchamber. Image artifacts due to diffraction at the worm bodies are reduced by decreasing illumination wavelength and object/camera distance. As an alternative to video acquisition, the filtered video Output signal is Used to determine worm activity, yielding a system that allows image acquisition in combination with a low-bandwidth activity Measurement, Using the described system, the activity of C elegans as a function of ambient temperature was measured. The nematodes were found to show an increase in stroke frequency with temperature. Data obtained by manual counting of worm strokes and the video signal showed good correlation. To our knowledge. this is the first demonstration of maintaining and monitoring C elegans in a microfluidic environment. © 2004 Elsevier B.V. All rights reserved. C1 Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Lange, D (reprint author), Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. EM dirk.lange@alumni.ethz.ch NR 24 TC 54 Z9 54 U1 2 U2 18 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD JUN 29 PY 2005 VL 107 IS 2 BP 904 EP 914 DI 10.1016/j.snb.2004.12.039 PG 11 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 932QC UT WOS:000229567400054 ER PT J AU Eremenko, MN Petelina, SV Zasetsky, AY Karlsson, B Rinsland, CP Llewellyn, EJ Sloan, JJ AF Eremenko, MN Petelina, SV Zasetsky, AY Karlsson, B Rinsland, CP Llewellyn, EJ Sloan, JJ TI Shape and composition of PMC particles derived from satellite remote sensing measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID POLAR MESOSPHERIC CLOUDS; NOCTILUCENT CLOUD; WATER-VAPOR; ICE; SPECTRA; DISTRIBUTIONS; CLIMATOLOGY; CLUSTERS; MISSION; H2O AB The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) on the SciSat satellite measured nearly 30 spectra of polar mesospheric clouds (PMCs) between 65 degrees and 70 degrees N from July 5 to 14, 2004. The ACE-FTS measurements are augmented by UV observations made at the same latitude and time period by the Optical Spectrograph and Infrared Imager System (OSIRIS) on the Odin satellite. Our analysis of these measurements shows that PMC particles are composed of nonspherical ice crystals with mean ( equivalent spherical) particle radii of 59 +/- 5 nm. C1 Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Univ Waterloo, Dept Phys, Waterloo, ON N2L 3G1, Canada. Univ Stockholm, Dept Meteorol, S-10691 Stockholm, Sweden. Univ Waterloo, Dept Phys, Waterloo, ON N2L 3G1, Canada. Univ Saskatchewan, Dept Phys & Engn, Saskatoon, SK, Canada. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. EM sloanj@uwaterloo.ca NR 28 TC 59 Z9 59 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 JUN 28 PY 2005 VL 32 IS 16 AR L16S06 DI 10.1029/2005GL023013 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 945CV UT WOS:000230480300001 ER PT J AU Santee, ML Manney, GL Livesey, NJ Froidevaux, L MacKenzie, IA Pumphrey, HC Read, WG Schwartz, MJ Waters, JW Harwood, RS AF Santee, ML Manney, GL Livesey, NJ Froidevaux, L MacKenzie, IA Pumphrey, HC Read, WG Schwartz, MJ Waters, JW Harwood, RS TI Polar processing and development of the 2004 Antarctic ozone hole: First results from MLS on Aura SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID UARS; VORTEX; MODEL; HCL; MCMURDO; CLO AB The Microwave Limb Sounder (MLS) on Aura is providing an extensive data set on stratospheric winter polar processing, including the first daily global observations of HCl, together with simultaneous measurements of ClO, HNO3, H2O, O-3, N2O, and temperature ( among others). We present first results charting the evolution of these quantities during the 2004 Antarctic late winter. MLS observations of chlorine deactivation and ozone loss during this period are shown to be consistent with results from the SLIMCAT chemical transport model. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Edinburgh, Sch Geosci, Edinburgh EH9 3JZ, Midlothian, Scotland. New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA. RP Santee, ML (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-701,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mls@mls.jpl.nasa.gov RI mackenzie, ian/E-9320-2013; Schwartz, Michael/F-5172-2016 OI Schwartz, Michael/0000-0001-6169-5094 NR 14 TC 24 Z9 26 U1 2 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 JUN 28 PY 2005 VL 32 IS 12 AR L12817 DI 10.1029/2005GL022582 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 945CN UT WOS:000230479500003 ER PT J AU Miller, Y Chaban, GM Gerber, RB AF Miller, Y Chaban, GM Gerber, RB TI Theoretical study of anharmonic vibrational spectra of HNO(3), HNO(3)-H(2)O, HNO(4): Fundamental, overtone and combination excitations SO CHEMICAL PHYSICS LA English DT Article DE vibrational spectroscopy; ab initio; nitric acid ID SELF-CONSISTENT-FIELD; DENSITY-FUNCTIONAL THEORY; PEROXYNITRIC ACID HOONO2; CIS-NITROUS ACID; AB-INITIO; NITRIC-ACID; BIOLOGICAL MOLECULES; TRANS-HONO; MEDIATED PHOTODISSOCIATION; PHOTOFRAGMENT SPECTROSCOPY AB Vibrational frequencies are computed for the fundamental, OH stretching overtone and combination transitions of HNO(3), HNO(4) and the HNO(3)-H(2)O complex. The frequencies are computed directly from ab initio MP2 potential surface points, using the correlation corrected vibrational self-consistent field (CC-VSCF) method, which includes anharmonic effects. The results are compared with experimental data. The computed fundamental transitions are in accord with experiment. The main improvement over the harmonic approximation is for the OH stretching frequencies. The OH overtone excitations (up to the 3rd overtone) of HNO(3), HNO(4) are also in good accord with experiment. For overtone levels near the dissociation threshold, the deviations from experiment are larger, as the VSCF method is unsatisfactory for the extremely large anharmonicities in these cases. Finally, very satisfactory results are obtained for the combination mode transitions. The main conclusions are (1) CC-VSCF seems to work well also for low overtone excitations and for combination transitions. (2) The MP2/TZP potential surfaces, used in the CC-VSCF calculations, are by the test of spectroscopy adequate for these species. The results are encouraging for VSCF calculations of larger, related systems such as HNO(3)-(H(2)O)(n) 17 > 1. (c) 2005 Elsevier B.V. All rights reserved. C1 Hebrew Univ Jerusalem, Dept Chem Phys, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Fritz Haber Res Ctr, IL-91904 Jerusalem, Israel. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RP Gerber, RB (reprint author), Hebrew Univ Jerusalem, Dept Chem Phys, IL-91904 Jerusalem, Israel. EM benny@fh.huji.ac.il NR 62 TC 51 Z9 51 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD JUN 27 PY 2005 VL 313 IS 1-3 BP 213 EP 224 DI 10.1016/j.chemphys.2005.01.012 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 920GM UT WOS:000228677400022 ER PT J AU Jordan, PM Puri, A AF Jordan, PM Puri, A TI Growth/decay of transverse acceleration waves in nonlinear elastic media SO PHYSICS LETTERS A LA English DT Article DE acceleration waves; finite time blow up; nonlinear elasticity; transverse waves ID BURGERS-EQUATION AB A study of transverse acceleration wave phenomena in the context of nonlinear elasticity is carried out. Using singular surface theory, exact amplitude expressions for acceleration waves arising from a sinusoidal boundary condition (BC) are obtained and their temporal evolution and propagation speeds determined. It is shown that amplitude blow up is possible only if the medium ahead is in motion, otherwise a constant amplitude wave occurs. Analytical results are illustrated numerically using simple computational methods/tools. Lastly, erroneous results that were reported in a recently published related study are noted and/or corrected. (c) 2005 Elsevier B.V. All rights reserved. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. RP USN, Res Lab, Stennis Space Ctr, Code 7181, Stennis Space Ctr, MS 39529 USA. EM pjordan@nrlssc.navy.mil NR 18 TC 19 Z9 19 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 EI 1873-2429 J9 PHYS LETT A JI Phys. Lett. A PD JUN 27 PY 2005 VL 341 IS 5-6 BP 427 EP 434 DI 10.1016/j.physleta.2005.05.010 PG 8 WC Physics, Multidisciplinary SC Physics GA 938ZM UT WOS:000230041900010 ER PT J AU Hergenrother, PM Thompson, CM Smith, JG Connell, JW Hinkley, JA Lyon, RE Moulton, R AF Hergenrother, PM Thompson, CM Smith, JG Connell, JW Hinkley, JA Lyon, RE Moulton, R TI Flame retardant aircraft epoxy resins containing phosphorus SO POLYMER LA English DT Article DE fire retardant; structural epoxy resins; phosphorus containing epoxies ID AMINOPHENYLMETHYLPHOSPHINE OXIDE; COMBUSTION PERFORMANCE; THERMAL-DECOMPOSITION AB As part of a program to develop fire resistant exterior composite structures for future subsonic commercial and general aviation aircraft, flame retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured neat epoxy formulations were characterized by thermogravimetric analysis, propane torch test, elemental analysis, microscale combustion calorimetry, and fire calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness and compressive strength of several cured formulations showed no detrimental effect due to phosphorus content. The chemistry and properties of these new epoxy formulations are discussed. (c) 2005 Elsevier Ltd. All rights reserved. C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Appl Poleram Inc, Benicia, CA 94510 USA. RP Thompson, CM (reprint author), Natl Inst Aerosp, 64 W Taylor St,MS 226, Hampton, VA 23666 USA. EM cthompso@nianet.org NR 33 TC 147 Z9 155 U1 7 U2 83 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD JUN 27 PY 2005 VL 46 IS 14 BP 5012 EP 5024 DI 10.1016/j.polymer.2005.04.025 PG 13 WC Polymer Science SC Polymer Science GA 937SJ UT WOS:000229945500005 ER PT J AU Cravens, TE Robertson, IP Clark, J Wahlund, JE Waite, JH Ledvina, SA Niemann, HB Yelle, RV Kasprzak, WT Luhmann, JG McNutt, RL Ip, WH De La Haye, V Muller-Wodarg, I Young, DT Coates, AJ AF Cravens, TE Robertson, IP Clark, J Wahlund, JE Waite, JH Ledvina, SA Niemann, HB Yelle, RV Kasprzak, WT Luhmann, JG McNutt, RL Ip, WH De La Haye, V Muller-Wodarg, I Young, DT Coates, AJ TI Titan's ionosphere: Model comparisons with Cassini Ta Data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID UPPER-ATMOSPHERE; MHD MODEL; PLASMA; MAGNETOSPHERE; SIMULATION AB [ 1] On October 26, 2004, during its first encounter with Titan ( Ta), the Cassini Orbiter moved from the dayside to the nightside with a closest approach altitude of 1174 km. In situ measurements of the main part of Titan's ionosphere were made by the Langmuir probe on the Cassini Radio and Plasma Wave Experiment ( RPWS), while the Ion and Neutral Mass Spectrometer ( INMS) measured the main constituents of the neutral atmosphere. The results of model calculations of Titan's ionosphere for Ta encounter conditions ( e. g., near the terminator) are presented in this paper. The paper includes comparisons of calculated and measured electron densities along the spacecraft track. Ionization both by solar radiation and by incoming energetic electrons from Saturn's magnetosphere are needed to obtain good agreement between the measured and calculated electron densities. C1 Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. Swedish Inst Space Phys, S-75591 Uppsala, Sweden. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Natl Cent Univ, Chungli 32054, Taiwan. Univ London Imperial Coll Sci Technol & Med, Space & Atmospher Phys Grp, London W1P 7PP, England. SW Res Inst, San Antonio, TX 78228 USA. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. RP Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. EM cravens@ku.edu RI Coates, Andrew/C-2396-2008; McNutt, Ralph/E-8006-2010; Mueller-Wodarg, Ingo/M-9945-2014 OI Coates, Andrew/0000-0002-6185-3125; McNutt, Ralph/0000-0002-4722-9166; Mueller-Wodarg, Ingo/0000-0001-6308-7826 NR 30 TC 67 Z9 67 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 JUN 25 PY 2005 VL 32 IS 12 AR L12108 DI 10.1029/2005GL023249 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 940UB UT WOS:000230169900006 ER PT J AU Le Clercq, PC Bellan, J AF Le Clercq, PC Bellan, J TI Direct numerical simulation of gaseous mixing layers laden with multicomponent-liquid drops: liquid-specific effects SO JOURNAL OF FLUID MECHANICS LA English DT Article ID MACH-NUMBER TURBULENCE; CONTINUOUS THERMODYNAMICS; EVAPORATING DROPS; FLOW SIMULATIONS; VAPORIZATION; MIXTURES; MODEL; COMBUSTION; COMPONENTS; DISPERSION AB A representation of multicomponent-liquid (MC-liquid) composition as a linear combination of two single-Gamma probability distribution functions (PDFs) is used to describe a large number of MC-liquid drops evaporating in a gas flow. The PDF, called the double-Gamma PDF, depends on the molar mass. The gas-phase conservation equations are written in an Eulerian frame and the drops are described in a Lagrangian frame. Gas conservation equations for mass, momentum, species and energy are combined with differential conservation equations for the first four moments of the gas-composition PDF and coupled to the perfect gas equation of state. Source terms in all conservation equations account for the gas/drop interaction. The drop governing equations encompass differential conservation statements for position, mass, momentum, energy and four moments of the liquid-composition PDF Simulations are performed for a three-dimensional mixing layer whose lower stream is initially laden with drops colder than the surrounding gas. Initial perturbations excite the layer to promote the double pairing of its four initial spanwise vortices to an ultimate vortex. During the layer evolution, the drops heat and evaporate. The results address the layer evolution, and the state of the gas and drops when layers reach a momentum-thickness maximum past the double vortex pairing. Of interest is the influence of the liquid composition on the development of the vortical features of the flow, on the vortical state reached after the second pairing, and on the gas temperature and composition. The MC-liquid simulations are initiated with a single-Gamma PDF composition so as to explore the development of the double-Gamma PDF. Examination of equivalent simulations with n-decane, diesel and three kerosenes as the liquid, permits assessment of the single-species versus the MC-liquid aspect, and of mixture composition specific effects. Global layer growth and global rotational characteristics are unaffected by liquid specificity; however, the global mixing is highly liquid-specific. Also liquid-specific is the evolution of the ensemble-averaged drop characteristics and of the volumetric averages representing the gas composition. Visualized rotational characteristics show that the small-scale vortical activity increases with increased fuel volatility, which is confirmed by analysis of the vorticity budgets. Homogeneous-plane-average budgets of the vorticity and vorticity-magnitude equations indicate that the stretching and tilting, and momentum-source terms are responsible for the difference among simulations. For all MC liquids, the gas displays a high level of composition heterogeneity, which can directly be traced to the original PDF representing the MC-liquid composition. Under most conditions, the single-Gamma PDF develops into a double-Gamma PDF; however, the extent of this transformation, indicative of vapour condensation onto drops, is not readily parametrized by the liquid volatility, initial carrier-gas temperature or trace vapour in the initial gas. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Le Clercq, PC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 39 TC 9 Z9 9 U1 1 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD JUN 25 PY 2005 VL 533 BP 57 EP 94 DI 10.1017/S0022112005003940 PG 38 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 948EK UT WOS:000230698600003 ER PT J AU Nghiem, SV Steffen, K Neumann, G Huff, R AF Nghiem, SV Steffen, K Neumann, G Huff, R TI Mapping of ice layer extent and snow accumulation in the percolation zone of the Greenland ice sheet SO JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE LA English DT Article ID SCATTEROMETER DATA; ELEVATION; RADAR; SCATTERERS; MEDIA AB [ 1] The Greenland ice sheet underwent record extensive melt in 2002 and prolonged melt in 2003. The severe melting created a significant and extensive ice layer over the Greenland ice sheet. An innovative approach is developed to detect the ice layer formation using data acquired by the SeaWinds scatterometer on the QuikSCAT satellite. QuikSCAT backscatter together with in situ data from automatic weather stations of the Greenland Climate Network are used to map the extent of ice layer formation. The results reveal areas of extensive ice layer formed by the 2002 melt, which is consistent with the maximum melt extent in 2002. Moreover, during freezing seasons, QuikSCAT data show a linear decrease in backscatter ( in decibels or dB) that is related to the amount of snow accumulation in the ice layer formation region. This snow accumulation signature is caused by the attenuation of radar waves in the snow layer, accumulating since the last major melt event, whose thickness appears as an exponential function in relation to the backscatter signature. We use the Greenland Climate Network data to calibrate the QuikSCAT accumulation rate in order to estimate and map snow accumulation. QuikSCAT results capture the extreme snowfall in mid-April 2003, which deposited more than 0.5 m of snow in a day as measured by the automated weather station at the NASA South East site. Large-scale QuikSCAT results show an anomalous increase of snow accumulation over the southeast region of Greenland during the 2002-2003 freezing season. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. RP CALTECH, Jet Prop Lab, MS 300-235,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM son.v.nghiem@jpl.nasa.gov RI Steffen, Konrad/C-6027-2013 OI Steffen, Konrad/0000-0001-8658-1026 NR 26 TC 30 Z9 31 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9003 EI 2169-9011 J9 J GEOPHYS RES-EARTH JI J. Geophys. Res.-Earth Surf. PD JUN 25 PY 2005 VL 110 IS F2 AR F02017 DI 10.1029/2004JF000234 PG 13 WC Geosciences, Multidisciplinary SC Geology GA 940UH UT WOS:000230170500002 ER PT J AU Manney, GL Santee, ML Livesey, NJ Froidevaux, L Read, WG Pumphrey, HC Waters, JW Pawson, S AF Manney, GL Santee, ML Livesey, NJ Froidevaux, L Read, WG Pumphrey, HC Waters, JW Pawson, S TI EOS Microwave Limb Sounder observations of the Antarctic polar vortex breakup in 2004 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOUTHERN-HEMISPHERE; STRATOSPHERE; DYNAMICS; AIR AB [ 1] New observations from the Microwave Limb Sounder ( MLS) on NASA's Aura satellite give a detailed picture of the spring Antarctic polar vortex breakup throughout the stratosphere, with the first daily global HCl profiles providing an unprecedentedly clear view of transport in the lower stratosphere. Poleward transport at progressively lower levels, filamentation, and mixing are detailed in MLS HCl, N2O, H2O, and O-3 as the 2004 Antarctic vortex broke up from the top down in early October through late December. Improved MLS H2O data show the subvortex, below the tropical tropopause, breaking up almost simultaneously with the lower stratospheric vortex in December. Vortex remnants persisted in MLS tracers for over a month after the breakup in the midstratosphere, but no more than a week in the lower stratosphere. MLS observations show diabatic descent continuing throughout November, but weak ascent after late October in the lower stratospheric vortex core. Our results extend previous observational transport studies and show consistency with mixing and vortex evolution in meteorological analyses, and with model studies. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA. Univ Edinburgh, Edinburgh, Midlothian, Scotland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP CALTECH, Jet Prop Lab, Mail Stop 183-701,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM manney@mls.jpl.nasa.gov RI Pawson, Steven/I-1865-2014 OI Pawson, Steven/0000-0003-0200-717X NR 16 TC 18 Z9 18 U1 1 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 JUN 23 PY 2005 VL 32 IS 12 AR L12811 DI 10.1029/2005GL022823 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 940TZ UT WOS:000230169700006 ER PT J AU Yang, ES Cunnold, DM Newchurch, MJ Salawitch, RJ AF Yang, ES Cunnold, DM Newchurch, MJ Salawitch, RJ TI Change in ozone trends at southern high latitudes SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTIC OZONE; RECOVERY AB [ 1] Long-term ozone variations at 60-70 degrees S in spring are investigated using ground-based and satellite measurements. Strong positive correlation is shown between year-to-year variations of ozone and temperature in the Antarctic collar region in Septembers and Octobers. Based on this relationship, the effect of year-to-year variations in vortex dynamics has been filtered out. This process results in an ozone time series that shows increasing springtime ozone losses over the Antarctic until the mid-1990s. Since approximately 1997 the ozone losses have leveled off. The analysis confirms that this change is consistent across all instruments and is statistically significant at the 95% confidence level. This analysis quantifies the beginning of the recovery of the ozone hole, which is expected from the leveling off of stratospheric halogen loading due to the ban on CFCs and other halocarbons initiated by the Montreal Protocol. C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91106 USA. RP Yang, ES (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. EM cunnold@eas.gatech.edu RI Salawitch, Ross/B-4605-2009 OI Salawitch, Ross/0000-0001-8597-5832 NR 9 TC 19 Z9 19 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 JUN 23 PY 2005 VL 32 IS 12 AR L12812 DI 10.1029/2004GL022296 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 940TZ UT WOS:000230169700003 ER PT J AU Kalas, P Graham, JR Clampin, M AF Kalas, P Graham, JR Clampin, M TI A planetary system as the origin of structure in Fomalhaut's dust belt SO NATURE LA English DT Article ID MAIN-SEQUENCE STARS; KUIPER-BELT; CIRCUMSTELLAR DISK; AU-MICROSCOPII; BETA-PICTORIS; NEARBY STARS; DEBRIS DISKS; SIGNATURES; VEGA; COBE AB The Sun and >15 per cent of nearby stars are surrounded by dusty disks that must be collisionally replenished by asteroids and comets, as the dust would otherwise be depleted on timescales <10(7) years (ref. 1). Theoretical studies show that the structure of a dusty disk can be modified by the gravitational influence of planets(2-4), but the observational evidence is incomplete, at least in part because maps of the thermal infrared emission from the disks have low linear resolution (35 AU in the best case(5)). Optical images provide higher resolution, but the closest examples (AU Mic and beta Pic) are edge-on(6,7), preventing the direct measurement of the azimuthal and radial disk structure that is required for fitting theoretical models of planetary perturbations. Here we report the detection of optical light reflected from the dust grains orbiting Fomalhaut (HD 216956). The system is inclined 248 away from edge-on, enabling the measurement of disk structure around its entire circumference, at a linear resolution of 0.5 AU. The dust is distributed in a belt 25 AU wide, with a very sharp inner edge at a radial distance of 133 AU, and we measure an offset of 15 AU between the belt's geometric centre and Fomalhaut. Taken together, the sharp inner edge and offset demonstrate the presence of planetary-mass objects orbiting Fomalhaut. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kalas, P (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. EM kalas@astron.berkeley.edu RI Clampin, mark/D-2738-2012 NR 28 TC 251 Z9 253 U1 1 U2 2 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUN 23 PY 2005 VL 435 IS 7045 BP 1067 EP 1070 DI 10.1038/nature03601 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 937ZT UT WOS:000229970400041 PM 15973402 ER PT J AU Rinsland, CP Boone, C Nassar, R Walker, K Bernath, P McConnell, JC Chiou, L AF Rinsland, CP Boone, C Nassar, R Walker, K Bernath, P McConnell, JC Chiou, L TI Atmospheric Chemistry Experiment (ACE) Arctic stratospheric measurements of NOx during February and March 2004: Impact of intense solar flares SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VORTEX; TRANSPORT; NITROGEN AB [ 1] Solar occultation measurements recorded in the Arctic by the Atmospheric Chemistry Experiment ( ACE) Fourier transform spectrometer show elevated volume mixing ratios of NO and NO2 in the upper stratosphere from mid-February to late March 2004. Mixing ratios of NO exceeded 1.3 ppmv ( 10(-6) parts per million by volume) during mid-February and are higher than any values previously reported in the Arctic during late winter and early spring. The elevated NOx ( NO + NO2) mixing ratios likely resulted from particle emissions by intense solar flares that occurred the previous October and November followed by NOx production and downward transport to the upper stratospheric vortex where the elevated levels persisted due to the long lifetime of NOx during darkness in polar winter and early spring. The descent and the NOx decrease rates in the upper stratospheric vortex are estimated from an analysis of the time series. The measured descent rate is compared with previous observations and model predictions. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. York Univ, Dept Earth & Atmospher Sci, Toronto, ON M3J 1P3, Canada. Sci Applicat Int Corp, Hampton, VA 23666 USA. RP NASA, Langley Res Ctr, Mail Stop 401A, Hampton, VA 23681 USA. EM c.p.rinsland@larc.nasa.gov; cboone@acebox.uwaterloo.ca; ray@acebox.uwaterloo.ca; kwalker@uwaterloo.ca; bernath@uwaterloo.ca; jcmcc@yorku.ca; l.s.chiou@larc.nasa.gov RI Bernath, Peter/B-6567-2012; OI Bernath, Peter/0000-0002-1255-396X; Nassar, Ray/0000-0001-6282-1611 NR 18 TC 41 Z9 41 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 JUN 22 PY 2005 VL 32 IS 16 AR L16S05 DI 10.1029/2005GL022425 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 940UD UT WOS:000230170100004 ER PT J AU Rinsland, CP Boone, C Nassar, R Walker, K Bernath, P Mahieu, E Zander, R McConnell, JC Chiou, L AF Rinsland, CP Boone, C Nassar, R Walker, K Bernath, P Mahieu, E Zander, R McConnell, JC Chiou, L TI Trends of HF, HCl, CCl2F2, CCl3F, CHClF2 (HCFC-22), and SF6 in the lower stratosphere from Atmospheric Chemistry Experiment (ACE) and Atmospheric Trace Molecule Spectroscopy (ATMOS) measurements near 30 degrees N latitude SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR ABSORPTION-MEASUREMENTS; LONG-TERM TREND; CHLORINE; SPECTRA AB [ 1] Volume mixing ratios ( VMRs) of HF, HCl, CCl2F2, CHClF2 ( HCFC-22), and SF6 in the lower stratosphere have been derived from solar occultation measurements recorded with spaceborne high resolution Fourier transform spectrometers. Atmospheric Chemistry Experiment ( ACE) VMRs measured during 2004 have been compared with those obtained in 1985 and 1994 by the Atmospheric Trace MOlecule Spectroscopy ( ATMOS) instrument. Trends are estimated by referencing the measured VMRs to those of the long-lived constituent N2O to account for variations in the dynamic history of the sampled air masses. Pressure-gridded measurements covering 10-100 hPa ( similar to 16 to 30 km altitude) were used in the analysis that includes typically 25 degrees N-35 degrees N latitude. The VMR changes provide further evidence of the impact of the emission restrictions imposed by the Montreal Protocol and its strengthening amendments and adjustments and are consistent with model predictions and known sources and sinks of halocarbons. Decreases in the lower stratospheric mixing ratios of CCl3F and HCl are measured in 2004 with respect to 1994, providing important confirmation of recent ground-based solar absorption measurements of a decline in inorganic chlorine. Trends estimates are compared with other reported measurements and model predictions. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Univ Liege, Inst Astrophys & Geophys, B-4000 Liege, Belgium. York Univ, Dept Earth & Atmospher Sci, Toronto, ON M3J 1P3, Canada. Sci Applicat Int Corp, Hampton, VA 23666 USA. RP NASA, Langley Res Ctr, Mail Stop 401A,21 Langley Blvd, Hampton, VA 23681 USA. EM c.p.rinsland@larc.nasa.gov; cboone@acebox.uwaterloo.co; ray@acebox.uwaterloo.ca; kwalker@uwaterloo.ca; bernath@uwaterloo.ca; emmanuel.mahieu@ulg.ac.be; r.zander@ulg.ac.be; jack@nimbus.yorku.ca; l.s.chiou@larc.nasa.gov RI Bernath, Peter/B-6567-2012 OI Bernath, Peter/0000-0002-1255-396X NR 14 TC 25 Z9 25 U1 0 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 JUN 22 PY 2005 VL 32 IS 16 AR L16S03 DI 10.1029/2005GL022415 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 940UD UT WOS:000230170100003 ER PT J AU Walker, KA Randall, CE Trepte, CR Boone, CD Bernath, PF AF Walker, KA Randall, CE Trepte, CR Boone, CD Bernath, PF TI Initial validation comparisons for the Atmospheric Chemistry Experiment (ACE-FTS) SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OZONE AB [ 1] The Atmospheric Chemistry Experiment Fourier Transform Spectrometer ( ACE-FTS) is the primary instrument for the ACE satellite mission. The initial validation of ozone profiles from ACE-FTS is based on comparisons with profiles from satellite-borne instruments and balloon-borne ozonesondes. The satellite instruments include the SAGE III and POAM III instruments. The ACE profiles were recorded during March 2004 at high latitudes in the northern hemisphere (> 65 degrees N) and were processed with the version 1.0 retrieval algorithm. The ACE-FTS results were found to agree within 10% with those from the other satellite measurements between 15 and 40 km, with ACE-FTS measuring less ozone near the profile maximum. The ACE-FTS has a lower vertical resolution than SAGE III or POAM III and this may contribute to the observed discrepancy. The comparisons with ozonesonde measurements suggest that the ACE-FTS accurately captures vertical structures in the ozone profile that are on the order of several kilometers thick. C1 Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Univ Waterloo, Dept Chem, 200 Univ Ave W, Waterloo, ON N2L 3G1, Canada. EM kwalker@uwaterloo.ca RI Bernath, Peter/B-6567-2012; Randall, Cora/L-8760-2014; OI Bernath, Peter/0000-0002-1255-396X; Randall, Cora/0000-0002-4313-4397; Shearer, Peter/0000-0002-2992-7630 NR 11 TC 31 Z9 31 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 JUN 22 PY 2005 VL 32 IS 16 AR L16S04 DI 10.1029/2005GL022388 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 940UD UT WOS:000230170100001 ER PT J AU Savigny, G Currie, JR Ila, D Zimmerman, RL Muntele, CI Mu, R Ueda, A AF Savigny, G Currie, JR Ila, D Zimmerman, RL Muntele, CI Mu, R Ueda, A TI Ion beam induced modification of nanolayers containing vanadium and silica SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th International Conference on Surface Modification of Materials by Ion Beams CY SEP 21-26, 2003 CL San Antonio, TX SP SW Res Inst DE ion beam mixing; nanolayers; vanadium nanocrystals; nano technology; ion beam modification AB dLayers of vanadium monoxide (VO) and pure silica were alternately deposited on a silica substrate. Similarly, layers of V2O3 and pure silica were alternately deposited on a silica substrate. The interfaces between the codeposited layers and pure silica layers were at no time exposed to air. Each sample was bombarded by 5.0 MeV Si beam at fluences between 10(15) and 10(17) ions/cm(2) at room temperature. Optical properties were measured using Optical Absorption Photospectrometry (OAP). The elemental distribution was measured using Rutherford Backscattering Spectrometry (RBS) at each step of Si bombardment. A different piece of each layered sample was annealed at temperatures between 100 and 1100 degrees C steps, for 1 h in argon environment. OAP and RBS were observed after each temperature. The dramatic apperance of an optical absortion resonance at 410 nm after heat treatment to 600 degrees C indicates that vanadium nanocrystals form in silica at that temperature. An ion bomdarment induced mixing coefficient is derived and experimentally evaluated for vanadium in silica. It is observed to increase with the accumulated fluence and multilayered samples. C1 Alabama A&M Univ, Ctr Irradiat Mat, Normal, AL 35762 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Fisk Univ, Ctr Photon Mat & Devices, Phys Chem Lab, Nashville, TN USA. RP Zimmerman, RL (reprint author), Alabama A&M Univ, Ctr Irradiat Mat, POB 144, Normal, AL 35762 USA. EM rlzimm@cim.aamu.edu NR 5 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD JUN 22 PY 2005 VL 196 IS 1-3 BP 113 EP 117 DI 10.1016/j.surfcoat.2004.08.194 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 929VV UT WOS:000229375600023 ER PT J AU Iraci, LT Michelsen, RR Ashbourn, SFM Rammer, TA Golden, DM AF Iraci, LT Michelsen, RR Ashbourn, SFM Rammer, TA Golden, DM TI Uptake of hypobromous acid (HOBr) by aqueous sulfuric acid solutions: low-temperature solubility and reaction SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID ARCTIC OZONE DEPLETION; STRATOSPHERIC TEMPERATURES; MODEL-CALCULATIONS; BROMINE; HCL; HBR; CHEMISTRY; AEROSOLS; CHLORINE; WATER AB Hypobromous acid (HOBr) is a key species linking inorganic bromine to the chlorine and odd hydrogen chemical families. We have measured the solubility of HOBr in 45 - 70 wt% sulfuric acid solutions representative of upper tropospheric and lower stratospheric aerosol composition. Over the temperature range 201 - 252 K, HOBr is quite soluble in sulfuric acid, with an effective Henry's law coefficient, H* = 10(4) - 10(7) mol L-1 atm(-1). H* is inversely dependent on temperature, with Delta H =- 45.0 +/- 5.4 kJ mol(-1) and Delta S=- 101 +/- 24 J mol(-1) K-1 for 55 - 70 wt% H2SO4 solutions. Our study includes temperatures which overlap both previous measurements of HOBr solubility. For uptake into 55 - 70 wt% H2SO4, the solubility is described by log H*=(2349 +/- 280)/ T-(5.27 +/- 1.24). At temperatures colder than similar to 213 K, the solubility of HOBr in 45 wt% H2SO4 is at least a factor of five larger than in 70 wt% H2SO4, with log H*=( 3665 +/- 270)/ T-( 10.63 +/- 1.23). The solubility of HOBr is comparable to that of HBr, indicating that upper tropospheric and lower stratospheric aerosols should contain equilibrium concentrations of HOBr which equal or exceed those of HBr. Upon uptake of HOBr into aqueous sulfuric acid in the presence of other brominated gases, particularly for 70 wt% H2SO4 solution, our measurements demonstrate chemical reaction of HOBr followed by evolution of gaseous products including Br2O and Br-2. C1 NASA, Atmospher Chem & Dynam Branch, Ames Res Ctr, Moffett Field, CA 94035 USA. SRI Int, NSF, Res Experiences Undergrad Program, Menlo Pk, CA 94025 USA. Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. RP Iraci, LT (reprint author), NASA, Atmospher Chem & Dynam Branch, Ames Res Ctr, Mail Stop 245-5, Moffett Field, CA 94035 USA. EM Laura.T.Iraci@nasa.gov NR 38 TC 13 Z9 13 U1 0 U2 2 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JUN 21 PY 2005 VL 5 BP 1577 EP 1587 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 937RU UT WOS:000229944000002 ER PT J AU Rind, D Perlwitz, J Lonergan, P AF Rind, D Perlwitz, J Lonergan, P TI AO/NAO response to climate change: 1. Respective influences of stratospheric and tropospheric climate changes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ARCTIC OSCILLATION RESPONSE; NORTH-ATLANTIC OSCILLATION; PINATUBO ERUPTION; EXTRATROPICAL CIRCULATION; HEMISPHERE WINTER; SPATIAL STRUCTURE; GREENHOUSE GASES; OZONE DEPLETION; MAUNDER MINIMUM; SOLAR INFLUENCE AB [1] We utilize the GISS Global Climate Middle Atmosphere Model and eight different climate change experiments, many of them focused on stratospheric climate forcings, to assess the relative influence of tropospheric and stratospheric climate change on the extratropical circulation indices (Arctic Oscillation, AO; North Atlantic Oscillation, NAO). The experiments are run in two different ways: with variable sea surface temperatures (SSTs) to allow for a full tropospheric climate response, and with specified SSTs to minimize the tropospheric change. The results show that experiments with tropospheric warming or stratospheric cooling produce more positive AO/ NAO indices. Experiments with tropospheric cooling or stratospheric warming produce a negative AO/NAO response. For the typical magnitudes of tropospheric and stratospheric climate changes, the tropospheric response dominates; results are strongest when the tropospheric and stratospheric influences are producing similar phase changes. Both regions produce their effect primarily by altering wave propagation and angular momentum transports, but planetary wave energy changes accompanying tropospheric climate change are also important. Stratospheric forcing has a larger impact on the NAO than on the AO, and the angular momentum transport changes associated with it peak in the upper troposphere, affecting all wavenumbers. Tropospheric climate changes influence both the AO and NAO with effects that extend throughout the troposphere. For both forcings there is often vertical consistency in the sign of the momentum transport changes, obscuring the difference between direct and indirect mechanisms for influencing the surface circulation. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10027 USA. SGT Corp, New York, NY USA. RP Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10027 USA. EM drind@giss.nasa.gov RI Perlwitz, Judith/B-7201-2008 OI Perlwitz, Judith/0000-0003-4061-2442 NR 56 TC 40 Z9 40 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 JUN 21 PY 2005 VL 110 IS D12 AR D12107 DI 10.1029/2004JD005103 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 940UG UT WOS:000230170400001 ER PT J AU Rind, D Perlwitz, J Lonergan, P Lerner, J AF Rind, D Perlwitz, J Lonergan, P Lerner, J TI AO/NAO response to climate change: 2. Relative importance of low- and high-latitude temperature changes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTH-ATLANTIC OSCILLATION; DOUBLED CO2 CLIMATE; SEA-LEVEL PRESSURE; ARCTIC OSCILLATION; MIDDLE ATMOSPHERE; PROJECTED CHANGES; EL-NINO; PART II; SIMULATION; VARIABILITY AB [1] We address the issue of why different models may be getting different responses of the AO/ NAO in climate change experiments. The results from part 1 (Rind et al., 2005) suggest that for substantive climate changes, the differences are likely to be found in the patterns of tropospheric climate change, rather than from the stratosphere. We assess the various tropospheric forcings through a variety of experiments. We first use extreme paleoclimate experiments (Ice Age, Paleocene) which feature large variations in the low level latitudinal temperature gradient; the results show that under these circumstances, changes in the eddy transport of sensible heat, and in situ high latitude forcing, dominate the AO response. We next test the effect of more modest SST temperature gradient changes in the current climate, and find a similar result with a model configuration that does not easily transport the low level temperature changes into the upper troposphere. We then reanalyze the results from different 2 x CO2 experiments with the GISS model and find that they can be understood by assessing: (1) the magnitude of tropical SST warming; (2) the translations of that warming into the upper troposphere; (3) the change in the extratropical low altitude temperature gradient; and (4) the change in the high latitude SST/sea ice response. We suggest that these features might explain the varying results among modeling groups, and that forecasts will not converge until these features do. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10027 USA. SGT Corp, New York, NY USA. RP Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10027 USA. EM drind@giss.nasa.gov RI Perlwitz, Judith/B-7201-2008 OI Perlwitz, Judith/0000-0003-4061-2442 NR 42 TC 28 Z9 28 U1 2 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 JUN 21 PY 2005 VL 110 IS D12 AR D12108 DI 10.1029/2004JD005686 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 940UG UT WOS:000230170400003 ER PT J AU Rosenfield, JE Frith, SM Stolarski, RS AF Rosenfield, JE Frith, SM Stolarski, RS TI Version 8 SBUV ozone profile trends compared with trends from a zonally averaged chemical model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MOUNT-PINATUBO AEROSOL; NIMBUS-7 SBUV; STRATOSPHERE AB [1] A statistical time series analysis was applied to the new version 8 merged Solar Backscatter Ultraviolet (SBUV) data set of ozone profiles for the years 1979 - 2003. Linear trends for the 1979 - 1997 time period are reported and are compared to trends computed using ozone profiles from the Goddard Space Flight Center (GSFC) zonally averaged coupled model. Observed and modeled annual trends between 50 degrees N and 50 degrees S were a maximum in the higher latitudes of the upper stratosphere, with Southern Hemisphere (SH) trends greater than Northern Hemisphere (NH) trends. The observed upper stratospheric maximum annual trend is -7.0 +/- 2.0%/decade (2 sigma) at 47.5 degrees S and -4.7 +/- 1.3%/decade at 47.5 degrees N, to be compared with the modeled trends of -5.8 +/- 0.3%/decade in the SH and -5.2 +/- 0.3%/decade in the NH. Both observed and modeled trends are most negative in winter and least negative in summer, although the modeled seasonal difference is less than observed. Model trends are shown to be greatest in winter because of a repartitioning of chlorine species and the increasing abundance of chlorine with time. The model results illustrate the trend differences that can occur at 3 hPa depending on whether ozone profiles are in mixing ratio or number density coordinates and on whether they are recorded on pressure or altitude levels. C1 Univ Maryland Baltimore Cty, Goddar Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Sci Syst & Appl Inc, Lanham, MD USA. NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. RP Univ Maryland Baltimore Cty, Goddar Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. EM rose@euterpe.gsfc.nasa.gov RI Stolarski, Richard/B-8499-2013 OI Stolarski, Richard/0000-0001-8722-4012 NR 29 TC 12 Z9 12 U1 0 U2 1 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 JUN 21 PY 2005 VL 110 IS D12 AR D12302 DI 10.1029/2004JD005466 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 940UG UT WOS:000230170400002 ER PT J AU Tam, CKW Ju, H Jones, MG Watson, WR Parrott, TL AF Tam, CKW Ju, H Jones, MG Watson, WR Parrott, TL TI A computational and experimental study of slit resonators SO JOURNAL OF SOUND AND VIBRATION LA English DT Article ID AEROACOUSTICS; ACOUSTICS AB Computational and experimental studies are carried out to offer validation of the results obtained from direct numerical simulation (DNS) of the flow and acoustic fields of slit resonators. The test cases include slits with 90 degrees corners and slits with 45 degrees beveled edges housed inside an acoustic impedance tube. Slit widths of 0.05, 0. 10 and 0.20 in are used. Six frequencies from 0.5 to 3.0 kHz are chosen. Good agreement is found between computed and measured reflection factors. To provide a more critical test, comparisons are also made at frequencies near a natural resonance of the resonator. Again, good agreement is obtained. In addition, incident sound waves having a white noise spectrum and a prescribed pseudo-random noise spectrum are used in a subsequent series of tests. The computed broadband results are again found to agree well with experimental data. It is believed the present results provide strong support that DNS can eventually be a useful and accurate prediction tool for liner aeroacoustics. The usage of DNS as a design tool is discussed and illustrated by a simple example. (c) 2004 Elsevier Ltd. All rights reserved. C1 Florida State Univ, Dept Math, Tallahassee, FL 32306 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Tam, CKW (reprint author), Florida State Univ, Dept Math, Tallahassee, FL 32306 USA. EM tam@math.fsu.edu NR 14 TC 23 Z9 26 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 JUN 21 PY 2005 VL 284 IS 3-5 BP 947 EP 984 DI 10.1016/j.jsv.2004.07.013 PG 38 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 930FG UT WOS:000229400600022 ER PT J AU Badnell, NR Bautista, MA Butler, K Delahaye, F Mendoza, C Palmeri, P Zeippen, CJ Seaton, MJ AF Badnell, NR Bautista, MA Butler, K Delahaye, F Mendoza, C Palmeri, P Zeippen, CJ Seaton, MJ TI Updated opacities from the opacity project SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE atomic processes; radiative transfer; stars : interiors ID SOLAR; ABUNDANCES; OPAL AB Using the code AUTOSTRUCTURE, extensive calculations of inner-shell atomic data have been made for the chemical elements He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and Ni. The results are used to obtain updated opacities from the Opacity Project (OP). A number of other improvements on earlier work have also been included. Rosseland-mean opacities from the OP are compared with those from OPAL. Differences of 5 - 10 per cent occur. The OP gives the 'Z-bump', at log(T) similar or equal to 5.2, to be shifted to slightly higher temperatures. The opacities from the OP, as functions of temperature and density, are smoother than those from OPAL. The accuracy of the integrations used to obtain mean opacities can depend on the frequency mesh used. Tests involving variation of the numbers of frequency points show that for typical chemical mixtures the OP integrations are numerically correct to within 0.1 per cent. Prior to a number of recent investigations which have indicated a need for downward revisions in the solar abundances of oxygen and other elements, there was good agreement between properties of the Sun deduced from helioseismology and from stellar evolution models calculated using OPAL opacities. The revisions destroy that agreement. In a recent paper, Bahcall et al. argue that the agreement would be restored if opacities for the regions of the Sun with 2 x 10(6) <= T <= 5 x 10(6) K (0.7 - 0.4 R(circle dot)) were larger than those given by OPAL by about 10 per cent. In the region concerned, the present results from the OP do not differ from those of OPAL by more than 2.5 per cent. C1 Univ Strathclyde, Dept Phys, Glasgow G4 0NG, Lanark, Scotland. Inst Venezolano Invest Cient, Ctr Fis, Caracas 1020A, Venezuela. Univ Sternwarte Munchen, D-81679 Munich, Germany. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Observ Paris, LUTH, F-92195 Meudon, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Badnell, NR (reprint author), Univ Strathclyde, Dept Phys, Glasgow G4 0NG, Lanark, Scotland. EM badnell@phys.strath.ac.uk NR 24 TC 189 Z9 189 U1 0 U2 4 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 JUN 21 PY 2005 VL 360 IS 2 BP 458 EP 464 DI 10.1111/j.1365-2966.2005.08991.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 933OM UT WOS:000229642800005 ER PT J AU Rapetti, D Allen, SW Weller, J AF Rapetti, D Allen, SW Weller, J TI Constraining dark energy with X-ray galaxy clusters, supernovae and the cosmic microwave background SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE supernovae : general; galaxies : clusters : general; cosmic microwave background; cosmology : observations; cosmology : theory; X-rays : galaxies : clusters ID PROBE WMAP OBSERVATIONS; HUBBLE-SPACE-TELESCOPE; EQUATION-OF-STATE; HIGH-REDSHIFT SUPERNOVAE; COSMOLOGICAL CONSTANT; LUMINOSITY DISTANCE; POWER SPECTRUM; ANISOTROPY; UNIVERSE; ACCELERATION AB We present new constraints on the evolution of dark energy from an analysis of cosmic microwave background, supernova and X-ray galaxy cluster data. Our analysis employs a minimum of priors and exploits the complementary nature of these data sets. We examine a series of dark energy models with up to three free parameters: the current dark energy equation of state w(0), the early-time equation of state wet, and the scalefactor at transition at. From a combined analysis of all three data sets, assuming a constant equation of state and that the Universe is flat, we measure w(0) = -1.05(-0.12)(+0.10) Including wet as a free parameter and allowing the transition scalefactor to vary over the range 0.5 < alpha(t) < 0.95 where the data sets have discriminating power, we measure w(0) = -1.27(-0.39)(+0.33) and w(et) = -0.66(-0.62)(+0.44). We find no significant evidence for evolution in the dark energy equation-of-state parameter with redshift. Marginal hints of evolution in the supernovae data become less significant when the cluster constraints are also included in the analysis. The complementary nature of the data sets leads to a tight constraint on the mean matter density Omega m and alleviates a number of other parameter degeneracies, including that between the scalar spectral index n(s), the physical baryon density Omega(b)h(2) and the optical depth tau. This complementary nature also allows us to examine models in which we drop the prior on the curvature. For non-flat models with a constant equation of state, we measure w(0) = -1.09(-0.15)(+0.12) and obtain a tight constraint on the current dark energy density Omega(de) = 0.70 +/- 0.03. For dark energy models other than a cosmological constant, energy-momentum conservation requires the inclusion of spatial perturbations in the dark energy component. Our analysis includes such perturbations, assuming a sound speed c(s)(2) = 1 in the dark energy fluid as expected for quintessence scenarios. For our most general dark energy model, not including such perturbations would lead to spurious constraints on wet, which would be tighter than those mentioned above by approximately a factor of 2 with the current data. C1 Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Barcelona, Dept Astron & Meteorol, E-08028 Barcelona, Spain. Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA. NASA, Fermilab Astrophys Grp, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Rapetti, D (reprint author), Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England. EM drapetti@ast.cam.ac.uk RI Rapetti, David/E-6032-2015; OI Rapetti, David/0000-0003-2196-6675; Weller, Jochen/0000-0002-8282-2010 NR 49 TC 107 Z9 107 U1 0 U2 0 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 JUN 21 PY 2005 VL 360 IS 2 BP 555 EP 564 DI 10.1111/j.1365-2966.2005.09067.x PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 933OM UT WOS:000229642800013 ER PT J AU Miller, MA Knobelspiesse, K Frouin, R Bartholomew, MJ Reynolds, RM Pietras, C Fargion, G Quinn, P Thieuleux, F AF Miller, MA Knobelspiesse, K Frouin, R Bartholomew, MJ Reynolds, RM Pietras, C Fargion, G Quinn, P Thieuleux, F TI Analysis of shipboard aerosol optical thickness measurements from multiple sunphotometers aboard the R/V Ronald H. Brown during the Aerosol Characterization Experiment-Asia SO APPLIED OPTICS LA English DT Article ID SUN PHOTOMETERS; RADIOMETER; CALIBRATION; AERONET; DESIGN; OCEANS AB Marine sunphotometer measurements collected aboard the R/V Ronald H. Brown during the Aerosol Characterization Experiment-Asia (ACE-Asia) are used to evaluate the ability of complementary instrumentation to obtain the best possible estimates of aerosol optical thickness and Angstrom exponent from ships at sea. A wide range of aerosol conditions, including clean maritime conditions and highly polluted coastal environments, were encountered during the ACE-Asia cruise. The results of this study suggest that shipboard hand-held sunphotometers and fast-rotating shadow-band radiometers (FRSRs) yield similar measurements and uncertainties if proper measurement protocols are used and if the instruments are properly calibrated. The automated FRSR has significantly better temporal resolution (2 min) than the hand-held sunphotometers when standard measurement protocols are used, so it more faithfully represents the variability of the local aerosol structure in polluted regions. Conversely, results suggest that the hand-held sunphotometers may perform better in clean, maritime air masses for unknown reasons. Results also show that the statistical distribution of the Angstrom exponent measurements is different when the distributions from hand-held surphotometers are compared with those from the FRSR and that the differences may arise from a combination of factors. (c) 2005 Optical Society of America C1 Brookhaven Natl Lab, Earth Syst Sci Div, Upton, NY 11973 USA. NASA, Goddard Space Flight Ctr, NASA SIMBIOS Project, Greenbelt, MD 20771 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Pacific Marine Environm Lab, Seattle, WA USA. Univ Sci & Technol, Villeneuve Dascq, France. RP Brookhaven Natl Lab, Earth Syst Sci Div, Bldg 490D, Upton, NY 11973 USA. EM miller@bnl.gov RI Quinn, Patricia/R-1493-2016; Knobelspiesse, Kirk/S-5902-2016 OI Quinn, Patricia/0000-0003-0337-4895; Knobelspiesse, Kirk/0000-0001-5986-1751 NR 25 TC 2 Z9 2 U1 1 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 JUN 20 PY 2005 VL 44 IS 18 BP 3805 EP 3820 DI 10.1364/AO.44.003805 PG 16 WC Optics SC Optics GA 938IC UT WOS:000229992100022 PM 15989056 ER PT J AU Holden, BP Blakeslee, JP Postman, M Illingworth, GD Demarco, R Franx, M Rosati, P Bouwens, RJ Martel, AR Ford, H Clampin, M Hartig, GF Benitez, N Cross, NJG Homeier, N Lidman, C Menanteau, F Zirm, A Ardila, DR Bartko, F Bradley, LD Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Feldman, PD Golimowski, DA Goto, T Gronwall, C Infante, L Kimble, RA Krist, JE Lesser, MP Magee, D Mei, S Meurer, GR Miley, GK Motta, V Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W AF Holden, BP Blakeslee, JP Postman, M Illingworth, GD Demarco, R Franx, M Rosati, P Bouwens, RJ Martel, AR Ford, H Clampin, M Hartig, GF Benitez, N Cross, NJG Homeier, N Lidman, C Menanteau, F Zirm, A Ardila, DR Bartko, F Bradley, LD Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Feldman, PD Golimowski, DA Goto, T Gronwall, C Infante, L Kimble, RA Krist, JE Lesser, MP Magee, D Mei, S Meurer, GR Miley, GK Motta, V Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W TI Evolution in the cluster early-type galaxy size-surface brightness relation at z similar or equal to 1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : general; galaxies : clusters : individual (RDCS J1252.9-2927, RX J1052.7-1357); galaxies : elliptical and lenticular, cD; galaxies : evolution; galaxies : fundamental parameters; galaxies : photometry ID COLOR-MAGNITUDE RELATION; HIGH-REDSHIFT CLUSTERS; DIGITAL SKY SURVEY; FUNDAMENTAL PLANE; DISTANT CLUSTERS; CL 1358+62; LUMINOSITY EVOLUTION; SPECTROSCOPIC SURVEY; ELLIPTIC GALAXIES; ADVANCED CAMERA AB We investigate the evolution in the distribution of surface brightness, as a function of size, for elliptical and S0 galaxies in the two clusters RDCS J1252.9 - 2927 ( z = 1: 237) and RX J0152.7 - 1357 ( z = 0: 837). We use multicolor imaging with the Advanced Camera for Surveys on the Hubble Space Telescope to determine these sizes and surface brightnesses. Using three different estimates of the surface brightnesses, we find that we reliably estimate the surface brightness for the galaxies in our sample with a scatter of < 0.2 mag and with systematic shifts of <= 0.05 mag. We construct samples of galaxies with early- type morphologies in both clusters. For each cluster, we use a magnitude limit in a band that closely corresponds to the rest- frame B, to magnitude limit of M-B = - 18: 8 at z = 0, and select only those galaxies within the color- magnitude sequence of the cluster or by using our spectroscopic redshifts. We measure evolution in the rest- frame B surface brightness and find - 1: 41 +/- 0: 14 mag from the Coma Cluster of galaxies for RDCS J1252.9 - 2927 and - 0: 90 +/- 0: 12 mag of evolution for RX J0152.7 - 1357, or an average evolution of ( - 1: 13 +/- 0: 15) z mag. Our statistical errors are dominated by the observed scatter in the size - surface brightness relation, sigma = 0: 42 +/- 0: 05 mag for RX J0152.7 - 1357 and sigma = 0: 76 +/- 0: 10 mag for RDCS J1252.9 - 2927. We find no statistically significant evolution in this scatter, although an increase in the scatter could be expected. Overall, the pace of luminosity evolution we measure agrees with that of the fundamental plane of early- type galaxies, implying that the majority of massive early- type galaxies observed at z similar or equal to 1 formed at high redshifts. C1 Univ Calif Santa Cruz, UCO, Lick Observ, Dept Astron, Santa Cruz, CA 95064 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. European So Observ, D-85748 Garching, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Astrofis Andalucia, Granada 18008, Spain. European So Observ, Santiago 19001, Chile. Bartko Sci & Technol, Brighton, CO 80602 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Conceptual Analyt LLC, Glenn Dale, MD 20769 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago, Chile. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. WM Keck Observ, Kamuela, HI 96743 USA. RP Holden, BP (reprint author), Univ Calif Santa Cruz, UCO, Lick Observ, Dept Astron, Santa Cruz, CA 95064 USA. EM holden@ucolick.org RI White, Richard/A-8143-2012; Clampin, mark/D-2738-2012; Kimble, Randy/D-5317-2012; OI Benitez, Narciso/0000-0002-0403-7455 NR 62 TC 34 Z9 34 U1 0 U2 1 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 JUN 20 PY 2005 VL 626 IS 2 BP 809 EP 822 DI 10.1086/430248 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 935PU UT WOS:000229795000014 ER PT J AU Rodriguez, M Rubin, RH AF Rodriguez, M Rubin, RH TI The [Fe IV] discrepancy: Constraining the iron abundances in nebulae SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; ISM : abundances ID PHOTOIONIZATION CROSS-SECTIONS; TELESCOPE ECHELLE SPECTROPHOTOMETRY; ELECTRON-ION RECOMBINATION; DWARF GALAXY SBS-0335-052; HUBBLE-SPACE-TELESCOPE; SMALL-MAGELLANIC-CLOUD; LINE-OF-SIGHT; H-II REGIONS; ORION NEBULA; CHEMICAL ABUNDANCES AB We study the current discrepancy between the model- predicted and measured concentrations of Fe++ and Fe+3 in ionized nebulae. We calculate a set of photoionization models, updated with the atomic data relevant to the problem, and compare their results with those derived for the available nebulae where both [ Fe III] and [ Fe IV] lines have been measured. Our new model results are closer to the measured values than the results of previous calculations, but a discrepancy remains. This discrepancy translates into an uncertainty in the derived Fe abundances of a factor of up to similar to 4. We explore the possible causes of this discrepancy and find that errors in the Fe atomic data may be the most likely explanation. The discrepancy can be fully accounted for by any of the following changes: ( 1) an increase by a factor of similar to 10 in the recombination rate ( radiative plus dielectronic, or charge transfer) for Fe+3, ( 2) an increase by a factor of 2 - 3 in the effective collision strengths for Fe++, or ( 3) a decrease by a factor of 2 - 3 in the effective collision strengths for Fe+3. We derive the Fe abundances implied by these three explanations and use the results to constrain the degree of depletion of Fe in our sample nebulae. The Galactic H II regions and planetary nebulae are found to have high depletion factors, with less than 5% of their Fe atoms in the gas phase. The extragalactic H II regions ( LMC 30 Doradus, SMC N88A, and SBS 0335 - 052) have somewhat lower depletions. The metal- deficient blue compact galaxy SBS 0335 - 052 could have from 13% to 40% of Fe in the gas phase. The depletions derived for the different objects define a trend of increasing depletion at higher metallicities. C1 INAOE, Puebla 72000, Mexico. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Rodriguez, M (reprint author), INAOE, Apartado Postal 51-216, Puebla 72000, Mexico. EM mrodri@inaoep.mx; rubin@cygnus.arc.nasa.gov NR 54 TC 48 Z9 48 U1 0 U2 1 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 JUN 20 PY 2005 VL 626 IS 2 BP 900 EP 908 DI 10.1086/429958 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 935PU UT WOS:000229795000022 ER PT J AU Bernstein, MP Mattioda, AL Sandford, SA Hudgins, DM AF Bernstein, MP Mattioda, AL Sandford, SA Hudgins, DM TI Laboratory infrared spectra of polycyclic aromatic nitrogen heterocycles: Quinoline and phenanthridine in solid argon and H2O SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : ISM; ISM : clouds; ISM : lines and bands; ISM : molecules; line : formation; molecular data ID 3 MICRON SPECTRA; ABSORPTION FEATURES; BENDING MODES; ICE BANDS; MU-M; HYDROCARBONS; SPECTROSCOPY; MOLECULES; EMISSION; DUST AB Polycyclic aromatic hydrocarbons ( PAHs) are common throughout the universe. Their detection and identification are based on the comparison of IR observations with laboratory spectra. Polycyclic aromatic nitrogen heterocycles ( PANHs) are heterocyclic aromatics, i. e., PAHs with carbon atoms replaced by a nitrogen atom. These molecules should be present in the interstellar medium, but have received relatively little attention. We present mid-IR spectra of two PANHs, quinoline ( C9H7N) and phenanthridine ( C13H9N), isolated in solid argon and frozen in solid H2O at 15 K, conditions yielding data directly comparable to astronomical observations. Quinoline and phenanthridine have been detected in meteorite extracts, and in general these nitrogen heterocycles are of astrobiological interest, since this class of molecules includes nucleobases, basic components of our nucleic acids. In contrast to simple PAHs, which do not interact strongly with solid H2O, the nitrogen atoms in PANHs are potentially capable of hydrogen bonding with H2O. Whereas the IR spectrum of phenanthridine in H2O is similar to that of the same compound isolated in an argon matrix, quinoline absorptions shift up to 16 cm(-1) ( 0.072 mu m) between argon and H2O. Thus, astronomers will not always be able to rely on IR band positions of matrix- isolated PANHs to correctly interpret the absorptions of PANHs frozen in H2O ice grains. Furthermore, our data suggest that relative band areas also vary, so determining column densities to better than a factor of 3 will require knowledge of the matrix in which the PANH is embedded and laboratory studies of relevant samples. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94043 USA. RP Bernstein, MP (reprint author), NASA, Ames Res Ctr, Ms 245-6, Moffett Field, CA 94035 USA. NR 29 TC 25 Z9 25 U1 0 U2 8 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 JUN 20 PY 2005 VL 626 IS 2 BP 909 EP 918 DI 10.1086/430120 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 935PU UT WOS:000229795000023 ER PT J AU Beichman, CA Bryden, G Gautier, TN Stapelfeldt, KR Werner, MW Misselt, K Rieke, G Stansberry, J Trilling, D AF Beichman, CA Bryden, G Gautier, TN Stapelfeldt, KR Werner, MW Misselt, K Rieke, G Stansberry, J Trilling, D TI An excess due to small grains around the nearby K0V star HD 69830: Asteroid or cometary debris? SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; comets : general; infrared : stars; Kuiper Belt; planetary systems ID MAIN-SEQUENCE STARS; BOPP C/1995 O1; PICTORIS CIRCUMSTELLAR DISK; SPITZER-SPACE-TELESCOPE; HALE-BOPP; BETA-PICTORIS; SOLAR-SYSTEM; SILICATE MINERALOGY; MASS-LOSS; HD 100546 AB Spitzer photometry and spectroscopy of the star HD 69830 reveal an excess of emission relative to the stellar photosphere between 8 and 35 mu m dominated by strong features attributable to crystalline silicates with an emitting surface area more than 1000 times that of our zodiacal cloud. The spectrum closely resembles that of the comet C/1995 O1 (Hale-Bopp). Since no excess is detected at 70 mu m, the emitting material must be quite warm, be confined within a few AU of the star, and originate in grains with low, long-wavelength emissivity, i.e., grains much smaller than 70 mu m/2 pi similar to 10 mu m. The strong mineralogical features are evidence for even smaller, possibly submicronsized grains. This small grain size is in direct contrast to the 10-100 mu m grains that dominate the relatively featureless spectra of our zodiacal dust cloud and most other main-sequence stars with excesses. The upper limit at 70 mu m also implies that any Kuiper Belt analog must be either very cold or less massive than similar to 5 times our own Kuiper Belt. With collisional and Poynting-Robertson drag times of less than 1000 yr for small grains, the emitting material must either (1) be created through continual grinding down of material in a dense asteroid belt, or ( 2) originate in cometary debris arising from either a single "supercomet" or a very large number of individual comets arriving from a distant reservoir. In the case of a cometary origin for the emission, the mass requirements for continuous generation by many individual comets are unreasonable, and we favor the capture of a single super comet into a 0.5-1 AU orbit, where it can evolve a large number of small grains over a 2 Myr period. C1 CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Beichman, CA (reprint author), CALTECH, Michelson Sci Ctr, M-S 100-22, Pasadena, CA 91125 USA. EM chas@pop.jpl.nasa.gov RI Stapelfeldt, Karl/D-2721-2012 NR 84 TC 144 Z9 144 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 JUN 20 PY 2005 VL 626 IS 2 BP 1061 EP 1069 DI 10.1086/430059 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 935PU UT WOS:000229795000038 ER PT J AU Sui, LH Holman, GD Dennis, BR AF Sui, LH Holman, GD Dennis, BR TI Determination of low-energy cutoffs and total energy of nonthermal electrons in a solar flare on 2002 April 15 SO ASTROPHYSICAL JOURNAL LA English DT Article DE sun : flares; sun : x-rays; gamma rays ID X-RAY-EMISSION; MAGNETIC RECONNECTION; RHESSI; SPECTRA; MICROWAVE; BURSTS; MODEL; LOOPS; BREMSSTRAHLUNG; SPECTROSCOPY AB The determination of the low-energy cutoff to the spectrum of accelerated electrons is decisive for the estimation of the total nonthermal energy in solar flares. Because thermal bremsstrahlung dominates the low-energy part of flare X-ray spectra, this cutoff energy is difficult to determine with spectral fitting alone. We have used a new method that combines spatial, spectral, and temporal analysis to determine the cutoff energy for the M1.2 flare observed with RHESSI on 2002 April 15. A low-energy cutoff of 24 +/- 2 keV is required to ensure that the assumed thermal emissions always dominate over nonthermal emissions at low energies (< 20 keV) and that the spectral fitting results are consistent with the RHESSI light curves and images. With this cutoff energy, we obtain a total nonthermal energy in electrons of (1.6 +/- 1) x 10(30) ergs that is comparable to the peak energy in the thermal plasma, estimated from RHESSI observations to be (6 +/- 0.6) x 10(29) ergs assuming a filling factor of 1. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Sui, LH (reprint author), Catholic Univ Amer, Dept Phys, 620 Michigan Ave NE, Washington, DC 20064 USA. RI Dennis, Brian/C-9511-2012; Holman, Gordon/C-9548-2012 NR 41 TC 49 Z9 50 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 JUN 20 PY 2005 VL 626 IS 2 BP 1102 EP 1109 DI 10.1086/430086 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 935PU UT WOS:000229795000043 ER PT J AU Phillips, KJH Chifor, C Landi, E AF Phillips, KJH Chifor, C Landi, E TI The high-temperature response of the TRACE 171 angstrom and 195 angstrom channels SO ASTROPHYSICAL JOURNAL LA English DT Article DE sun : flares; sun : UV radiation; sun : x-rays; gamma rays ID ATOMIC DATABASE; EMISSION-LINES; CHIANTI; WAVELENGTHS; IONIZATION; TELESCOPE; PLASMAS; FLARES; RATES; LOOPS AB The CHIANTI spectral code is used to estimate line and continuum intensity contributions to the TRACE 171 and 195 angstrom channels, widely used for imaging a variety of solar features and phenomena, including quiet-Sun and active region loops and solar flares. It is shown that the 171 angstrom channel has a high-temperature response due to continuum and Fe xx line emission, so high-temperature (similar to 10-20 MK) features in flares, prominent in TRACE 195 angstrom images as well as in X-ray images from Yohkoh and RHESSI, are sometimes visible in images made in the 171 angstrom channel. Such features consist of hot loop-top emission, either confined spots or "spine" structures in loop arcades. This is illustrated with TRACE and X-ray flare images. C1 NASA, Goddard Space Flight Ctr, Natl Res Council, Greenbelt, MD 20771 USA. Catholic Univ Amer, Washington, DC 20064 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Artep Inc, Ellicott City, MD 21042 USA. RP Phillips, KJH (reprint author), NASA, Goddard Space Flight Ctr, Natl Res Council, Code 612, Greenbelt, MD 20771 USA. EM phillips@stars.gsfc.nasa.gov; chifor@stars.gsfc.nasa.gov; landi@poppeo.nrl.navy.mil RI Landi, Enrico/H-4493-2011 NR 14 TC 18 Z9 18 U1 0 U2 1 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 JUN 20 PY 2005 VL 626 IS 2 BP 1110 EP 1115 DI 10.1086/430128 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 935PU UT WOS:000229795000044 ER PT J AU Coates, AJ McAndrews, HJ Rymer, AM Young, DT Crary, FJ Maurice, S Johnson, RE Baragiola, RA Tokar, RL Sittler, EC Lewis, GR AF Coates, AJ McAndrews, HJ Rymer, AM Young, DT Crary, FJ Maurice, S Johnson, RE Baragiola, RA Tokar, RL Sittler, EC Lewis, GR TI Plasma electrons above Saturn's main rings: CAPS observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID IMAGING SCIENCE; MAGNETOSPHERE; SPECTROMETER AB We present observations of thermal ( similar to 0.6 - 100eV) electrons observed near Saturn's main rings during Cassini's Saturn Orbit Insertion (SOI) on 1 July 2004. We find that the intensity of electrons is broadly anticorrelated with the ring optical depth at the magnetic footprint of the field line joining the spacecraft to the rings. We see enhancements corresponding to the Cassini division and Encke gap. We suggest that some of the electrons are generated by photoemission from ring particle surfaces on the illuminated side of the rings, the far side from the spacecraft. Structure in the energy spectrum over the Cassini division and A-ring may be related to photoelectron emission followed by acceleration, or, more likely, due to photoelectron production in the ring atmosphere or ionosphere. C1 UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. SW Res Inst, San Antonio, TX 78228 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Virginia, Charlottesville, VA 22903 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Coates, AJ (reprint author), UCL, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England. EM ajc@mssl.ucl.ac.uk RI Coates, Andrew/C-2396-2008 OI Coates, Andrew/0000-0002-6185-3125 NR 20 TC 24 Z9 24 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 JUN 18 PY 2005 VL 32 IS 14 AR L14S09 DI 10.1029/2005GL022694 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 938GN UT WOS:000229988000001 ER PT J AU Lim, JR Whitacre, JF Fleurial, JP Huang, CK Ryan, MA Myung, NV AF Lim, JR Whitacre, JF Fleurial, JP Huang, CK Ryan, MA Myung, NV TI Fabrication method for thermoelectric nanodevices SO ADVANCED MATERIALS LA English DT Article ID NANOWIRE ARRAYS; ALUMINA AB Thermoelectric nanowire-based devices are fabricated by the electrodeposition of n-type Bi2Te3 and p-type BiSbTe nanowire bundles within the same alumina nanotemplate (see Figure). The nanowire bundles are approximately 50 nm in diameter and consist of nanowires 200 nm in diameter and 40 nm in length. These nanostructured materials could be used to create higher-efficiency power generation or cooling devices. C1 Univ Calif Riverside, Ctr Nanoscale Sci & Engn, Dept Chem & Environm Engn, Riverside, CA 92521 USA. Univ Calif Los Angeles, Dept Mat Sci & Engn, Biomed Engn IDP, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Electrochem Technol Grp, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, Mat & Device Technol Grp, Pasadena, CA 91109 USA. RP Univ Calif Riverside, Ctr Nanoscale Sci & Engn, Dept Chem & Environm Engn, Riverside, CA 92521 USA. EM myung@engr.ucr.edu NR 27 TC 54 Z9 54 U1 1 U2 46 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 0935-9648 EI 1521-4095 J9 ADV MATER JI Adv. Mater. PD JUN 17 PY 2005 VL 17 IS 12 BP 1488 EP 1492 DI 10.1002/adma.200401189 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 936YK UT WOS:000229891300007 ER PT J AU Levy-Clement, C Tena-Zaera, R Ryan, MA Katty, A Hodes, G AF Levy-Clement, C Tena-Zaera, R Ryan, MA Katty, A Hodes, G TI CdSe-Sensitized p-CuSCN/nanowire n-ZnO heterojunctions SO ADVANCED MATERIALS LA English DT Article ID EXTREMELY THIN ABSORBER; SOLAR-CELLS; PHOTOVOLTAIC CELL; ZINC-OXIDE; FILMS; ELECTRODEPOSITION; DEPOSITION; ETA AB A fully inorganic analogue of the nanostructured dye-sensitized solar cell is fabricated using an electrochemically grown n-ZnO/CdSe core-shell nanowire array (see Figure). Filling the voids between the nanowires with p-type wide-bandgap CuSCN by a solution-deposition technique leads to an extremely thin solar cell exhibiting 2.3 % energy-conversion efficiency. C1 CNRS, LCMTR, F-94320 Thiais, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Weizmann Inst Sci, Dept Mat & Interfaces, IL-76100 Rehovot, Israel. Univ Valencia, E-46100 Burjassot, Spain. RP CNRS, LCMTR, 2-9 Rue Henri Dunant, F-94320 Thiais, France. EM claude.levy-clement@glvt-cnrs.fr RI Tena-Zaera, Ramon/M-2413-2014 OI Tena-Zaera, Ramon/0000-0002-1525-7760 NR 28 TC 309 Z9 310 U1 13 U2 126 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 0935-9648 EI 1521-4095 J9 ADV MATER JI Adv. Mater. PD JUN 17 PY 2005 VL 17 IS 12 BP 1512 EP 1515 DI 10.1002/adma.200401848 PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 936YK UT WOS:000229891300013 ER PT J AU Zhang, XY Friedl, MA Schaaf, CB Strahler, AH Liu, Z AF Zhang, XY Friedl, MA Schaaf, CB Strahler, AH Liu, Z TI Monitoring the response of vegetation phenology to precipitation in Africa by coupling MODIS and TRMM instruments SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MEASURING MISSION TRMM; SOUTHERN AFRICA; RAINY-SEASON; INTERANNUAL VARIABILITY; RAINFALL VARIABILITY; CLIMATIC-CHANGE; WEST-AFRICA; SOIL TYPE; GROWTH; ONSET AB [1] While temperature controls on vegetation phenology in humid temperate climates have been widely investigated, water availability is the primary limit on vegetation growth in arid and semiarid ecosystems at continental and global scales. This paper explores the response of vegetation phenology to precipitation across Africa from 2000 to 2003 using vegetation index data from the Moderate-Resolution Imaging Spectroradiometer (MODIS) and daily rainfall data obtained from the Tropical Rainfall Measuring Mission (TRMM). The results indicate that well-defined thresholds exist in cumulative rainfall that stimulate vegetation green-up in arid and semiarid regions of Africa. Therefore cumulative rainfall provides an appropriate criterion for determining the onset of the rainy season, which can be used to predict the onset of vegetation green-up. Following the end of the rainy season, the onset of vegetation dormancy occurs with a lag of about 54 and 84 days in the Sahelian and sub-Sahelian region and in southern Africa, respectively. Further, spatial patterns in vegetation phenology can be divided into three distinct regions in arid and semiarid ecosystems of Africa because of well-defined patterns in rainfall seasonality. In response to rainfall patterns controlled by the Intertropical Convergence Zone in the Sahelian and sub-Sahelian region, the timing of vegetation phenology shifts gradually in a north-south direction at a rate of 0.12 d/km for green-up onset and 0.05 d/km for dormancy onset. In contrast, patterns in vegetation phenology and rainfall seasonality are much more complex in southern Africa. The shift rates and trends in this region are consistent locally but vary abruptly across different ecosystems or climate regimes. Multiple annual cycles of vegetation growth closely follow rainy seasons in parts of the Greater Horn of Africa. C1 Boston Univ, Ctr Remote Sensing, Dept Geog, Boston, MA 02215 USA. NASA, Goddard Space Flight Ctr, Distributed Act Archive Ctr, Greenbelt, MD 20771 USA. George Mason Univ, Dept Comp Sci, Ctr Res Earth & Space Sci, Fairfax, VA 22030 USA. RP Zhang, XY (reprint author), NOAA, NESDIS, Ctr Satellite Applicat & Res, 5200 Auth Rd, Camp Springs, MD 20746 USA. EM xiaoyang.zhang@noaa.gov RI Zhang, Xiaoyang/E-3208-2010 NR 56 TC 83 Z9 83 U1 1 U2 31 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 JUN 17 PY 2005 VL 110 IS D12 AR D12103 DI 10.1029/2004JD005263 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 938HB UT WOS:000229989400001 ER PT J AU Dellnitz, M Junge, O Lo, MW Marsden, JE Padberg, K Preis, R Ross, SD Thiere, B AF Dellnitz, M Junge, O Lo, MW Marsden, JE Padberg, K Preis, R Ross, SD Thiere, B TI Transport of Mars-crossing asteroids from the quasi-Hilda region SO PHYSICAL REVIEW LETTERS LA English DT Article ID ASSISTED CAPTURE; INVARIANT-SETS; PLANETS; MAPS AB We employ set oriented methods in combination with graph partitioning algorithms to identify key dynamical regions in the Sun-Jupiter-particle three-body system. Transport rates from a region near the 32 Hilda resonance into the realm of orbits crossing Mars' orbit are computed. In contrast to common numerical approaches, our technique does not depend on single long term simulations of the underlying model. Thus, our statistical results are particularly reliable since they are not affected by a dynamical behavior which is almost nonergodic (i.e., dominated by strongly almost invariant sets). C1 Univ Paderborn, Fac Comp Sci Elect Engn & Math, D-33095 Paderborn, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. Univ So Calif, Dept Aerosp & Mech Engn, Los Angeles, CA 90089 USA. RP Dellnitz, M (reprint author), Univ Paderborn, Fac Comp Sci Elect Engn & Math, D-33095 Paderborn, Germany. RI Ross, Shane/B-7237-2009; Padberg-Gehle, Kathrin/F-9394-2010 OI Ross, Shane/0000-0001-5523-2376; Padberg-Gehle, Kathrin/0000-0002-1761-213X NR 17 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN 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 JUN 17 PY 2005 VL 94 IS 23 AR 231102 DI 10.1103/PhysRevLett.94.231102 PG 4 WC Physics, Multidisciplinary SC Physics GA 936LS UT WOS:000229858100012 PM 16090456 ER PT J AU Grooss, JU Gunther, G Muller, R Konopka, P Bausch, S Schlager, H Voigt, C Volk, CM Toon, GC AF Grooss, JU Gunther, G Muller, R Konopka, P Bausch, S Schlager, H Voigt, C Volk, CM Toon, GC TI Simulation of denitrification and ozone loss for the Arctic winter 2002/2003 SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID CHEMICAL LAGRANGIAN MODEL; NITRIC-ACID TRIHYDRATE; POLAR STRATOSPHERIC CLOUDS; PARTICLES; CLAMS; FORMULATION; CHEMISTRY; BALLOON; PSCS AB We present simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) for the Arctic winter 2002/2003. We integrated a Lagrangian denitrification scheme into the three-dimensional version of CLaMS that calculates the growth and sedimentation of nitric acid trihydrate (NAT) particles along individual particle trajectories. From those, we derive the HNO(3) downward flux resulting from different particle nucleation assumptions. The simulation results show a clear vertical redistribution of total inorganic nitrogen (NO(y)), with a maximum vortex average permanent NO(y) removal of over 5 ppb in late December between 500 and 550 K and a corresponding increase of NO(y) of over 2 ppb below about 450 K. The simulated vertical redistribution of NO(y) is compared with balloon observations by MkIV and in-situ observations from the high altitude aircraft Geophysica. Assuming a globally uniform NAT particle nucleation rate of 7.8 x 10(-6) cm(-3) h(-1) in the model, the observed denitrification is well reproduced. In the investigated winter 2002/2003, the denitrification has only moderate impact ( <= 14%) on the simulated vortex average ozone loss of about 1.1 ppm near the 460 K level. At higher altitudes, above 600 K potential temperature, the simulations show significant ozone depletion through NO(x)-catalytic cycles due to the unusual early exposure of vortex air to sunlight. C1 Forschungszentrum Julich, Inst Chem & Dynam Geosphare Stratosphare 1, Julich, Germany. DLR Oberpfaffenhofen, Inst Phys Atmosphare, Wesseling, Germany. Goethe Univ Frankfurt, Inst Meteorol & Geophys, D-6000 Frankfurt, Germany. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Grooss, JU (reprint author), Forschungszentrum Julich, Inst Chem & Dynam Geosphare Stratosphare 1, Julich, Germany. EM j.-u.grooss@fz-juelich.de RI Voigt, Christiane/G-3279-2010; Guenther, Gebhard/K-7583-2012; Muller, Rolf/A-6669-2013; Konopka, Paul/A-7329-2013; GrooSS, Jens-Uwe/A-7315-2013 OI Guenther, Gebhard/0000-0003-4111-6221; Muller, Rolf/0000-0002-5024-9977; GrooSS, Jens-Uwe/0000-0002-9485-866X NR 38 TC 49 Z9 50 U1 0 U2 1 PU COPERNICUS PUBLICATIONS PI KATHLENBURG-LINDAU PA MAX-PLANCK-STR 13, KATHLENBURG-LINDAU, 37191, GERMANY SN 1680-7316 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JUN 15 PY 2005 VL 5 BP 1437 EP 1448 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 936DS UT WOS:000229836300001 ER PT J AU Righter, K Campbell, AJ Humayun, M AF Righter, K Campbell, AJ Humayun, M TI Diffusion of trace elements in FeNi metal: Application to zoned metal grains in chondrites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID GAMMA-IRON; PHASE-EQUILIBRIA; SOLAR NEBULA; SYSTEM; NI; CONDENSATION; BENCUBBIN; ORIGIN; CONSTRAINTS; COBALT AB We have measured diffusion coefficients for P, Cr, Co, Ni, Cu, Ga, Ge, Rul, Pd, Ir, and An in Fe metal from 1150 to 1400 degrees C and at 1 bar and 10 kbar. Diffusion couples were prepared from high-purity Fe metal and metal from the IIA iron meteorite Coahuila (single crystal kamacite) or the pallasite Springwater (polycrystalline kamacite) and held at run conditions for 3.5 to 123 h. Diffusion profiles were measured using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) or the electron microprobe. Many elements were measured from the same experimental runs so interelemental comparisons are improved over other data sets in which data for different elements come from different experiments. Some literature diffusion coefficients (D) for Ni and Co in taenite can be up to a factor of 3 higher for Ni than Co, yet our results show no difference (e.g., D-Ni and D-Co similar to 2.2 X 10(-15) m(2)/S at 1150 degrees C). Thus, diffusion of Ni and Co in single crystal taenite will not measurably fractionate the Ni/Co ratio. On the other hand, the large difference in D-Ni and D, (D-Ir is similar to 5 times lower) and the similarity of D-Ni and D-Ru at all temperatures investigated indicates that Ni/Ir and Ni/Ru ratios in zoned metal grains will be useful discriminators of processes controlled by diffusion vs. volatility. In zoned metal grains in primitive chondrites, deviations of the Ni/Ru and Ni/Ir ratios from a condensation curve are opposite to a diffusion-controlled process, but consistent with a volatility-controlled process. The new multielement diffusion coefficients will also be useful in evaluating a variety of other processes in planetary science. Copyright (c) 2005 Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Righter, K (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code KT,2101 NASA Pkwy, Houston, TX 77058 USA. EM kevin.righter1@nasa.gov OI Humayun, Munir/0000-0001-8516-9435 NR 48 TC 26 Z9 26 U1 2 U2 14 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 JUN 15 PY 2005 VL 69 IS 12 BP 3145 EP 3158 DI 10.1016/j.gca.2005.01.010 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 940PO UT WOS:000230156600014 ER PT J AU Sittler, EC Thomsen, M Chornay, D Shappirio, MD Simpson, D Johnson, RE Smith, HT Coates, AJ Rymer, AM Crary, F McComas, DJ Young, DT Reisenfeld, D Dougherty, M Andre, N AF Sittler, EC Thomsen, M Chornay, D Shappirio, MD Simpson, D Johnson, RE Smith, HT Coates, AJ Rymer, AM Crary, F McComas, DJ Young, DT Reisenfeld, D Dougherty, M Andre, N TI Preliminary results on Saturn's inner plasmasphere as observed by Cassini: Comparison with Voyager SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAGNETOSPHERE; DYNAMICS; IONS AB We present an analysis of Saturn's inner plasmasphere as observed by the Cassini Plasma Spectrometer ( CAPS) experiment during Cassini's initial entry into Saturn's magnetosphere when the spacecraft was inserted into orbit around Saturn. The ion fluxes are divided into two subgroups: protons and water group ions. We present the relative amounts of these two groups and the first estimates of their fluid parameters: ion density, flow velocity and temperature. We also compare this data with electron plasma measurements. Within the plasmasphere and inside of Enceladus' orbit, water group ions are about a factor of similar to 10 greater than protons in number with number densities exceeding 40 cm(-3). Within this inner region the spacecraft acquires a negative potential so that the electron density is underestimated. The electron and proton temperatures, which could not be measured in this region by Voyager, are T similar to 2 eVat L similar to 3. Also, within this inner region the protons, because of a negative spacecraft potential, appear to be super-corotating. By enforcing the condition that protons and water group ions are co-moving we may be able to acquire an independent estimate of the spacecraft potential relative to that estimated when comparing ion-electron measurements. Using our estimates of plasma properties, we estimate the importance of the rotating plasma on the stress balance equation for the inner magnetosphere and corresponding portion of the ring current. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Virginia, Charlottesville, VA 22904 USA. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. SW Res Inst, San Antonio, TX 78228 USA. Univ Montana, Dept Phys & Astron, Missoula, MT 59812 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. RP Sittler, EC (reprint author), NASA, Goddard Space Flight Ctr, 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 NR 19 TC 34 Z9 34 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 JUN 15 PY 2005 VL 32 IS 14 AR L14S07 DI 10.1029/2005GL022653 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 938GH UT WOS:000229987400001 ER PT J AU Edmonds, LD AF Edmonds, LD TI High-level injection in n(+)-p junction silicon devices SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID P-N-JUNCTIONS; BOUNDARY-CONDITIONS; CHARGE COLLECTION; ION TRACKS AB It is argued that a silicon p-n junction diode operating at high injection in the forward direction can be analyzed by using the regional approximation together with the classical law of the junction. Erroneous predictions made in the past are attributed to incorrect equations describing the quasineutral regions. Corrected equations (exact analytical solutions) are given. (c) 2005 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Edmonds, LD (reprint author), CALTECH, Jet Prop Lab, Mail Stop 303-220,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM larry.d.edmonds@jpl.nasa.gov NR 14 TC 1 Z9 1 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 2005 VL 97 IS 12 AR 124506 DI 10.1063/1.1940134 PG 7 WC Physics, Applied SC Physics GA 942JG UT WOS:000230278100108 ER PT J AU Lin, B Wong, T Wielicki, BA Hu, YX AF Lin, B Wong, T Wielicki, BA Hu, YX TI Comments on "Examination of the decadal tropical mean ERBS nonscanner radiation data for the iris hypothesis" - Reply SO JOURNAL OF CLIMATE LA English DT Editorial Material ID POSITIVE CLOUD FEEDBACK; INFRARED IRIS; NO EVIDENCE; WATER-VAPOR; EARTH; CIRRUS C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Lin, B (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM bing.lin@nasa.gov RI Hu, Yongxiang/K-4426-2012 NR 17 TC 3 Z9 3 U1 0 U2 1 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 JUN 15 PY 2005 VL 18 IS 12 BP 2128 EP 2131 DI 10.1175/JCLI3393.1 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 941FB UT WOS:000230199600020 ER PT J AU Tansel, B Sager, J Rector, T Garland, J Strayer, RF Levine, L Roberts, M Hummerick, M Bauer, J AF Tansel, B Sager, J Rector, T Garland, J Strayer, RF Levine, L Roberts, M Hummerick, M Bauer, J TI Integrated evaluation of a sequential membrane filtration system for recovery of bioreactor effluent during long space missions SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article DE nanofiltration; reverse osmosis; membrane bioreactor; space craft wastewater; water reclamation ID WASTE-WATER TREATMENT; REVERSE-OSMOSIS; MICROFILTRATION; ULTRAFILTRATION; PRETREATMENT; SOLUTES; REUSE; RO AB Performance of an integrated membrane filtration system was investigated for treatment of the effluent from an aerated rotating membrane bioreactor system (ARMS). The ARMS is developed and operated at the Kennedy Space Center (KSC) as a potential technology for water recovery and recycling during long space missions. The 3 L bioreactor utilizes a rotating membrane module consisting of silastic hollow fibers for aeration and biofilm growth. Effluent from the ARMS contains high levels of dissolved inorganic solids. A sequential membrane filtration system consisting of prefiltration and reverse osmosis (RO) membranes was evaluated for treatment of the bioreactor effluent. To select an appropriate prefiltration membrane, a series of membrane screening experiments were conducted with two UF membranes (MWCO 10,000 and 50,000 Da) and a nanofiltration (NF) membrane using stirred filtration cells. In addition, integrated membrane filtration tests were conducted with the NF and RO membranes using a cross-flow membrane filtration unit. Effectiveness of the integrated membrane filtration system was evaluated in terms of flux and total solids rejection of the individual filtration steps as well as the overall system performance. © 2005 Elsevier B.V. All rights reserved. C1 Florida Int Univ, Dept Civil & Environm Engn, Miami, FL 33199 USA. NASA, Kennedy Space Ctr, Cape Canaveral, FL USA. Dynamac Corp, Kennedy Space Ctr, Cape Canaveral, FL USA. RP Tansel, B (reprint author), Florida Int Univ, Dept Civil & Environm Engn, Miami, FL 33199 USA. EM tanselb@fiu.edu NR 23 TC 10 Z9 10 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0376-7388 J9 J MEMBRANE SCI JI J. Membr. Sci. PD JUN 15 PY 2005 VL 255 IS 1-2 BP 117 EP 124 DI 10.1016/j.memsci.2005.01.028 PG 8 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 931WZ UT WOS:000229517500012 ER PT J AU Henin, J Pohorille, A Chipot, C AF Henin, J Pohorille, A Chipot, C TI Insights into the recognition and association of transmembrane alpha-helices. The free energy of alpha-helix dimerization in glycophorin A SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; SYNTHETIC PEPTIDES; MICELLE FORMATION; PROTEIN STRUCTURE; CHANNEL PROTEINS; LIPID-BILAYERS; 2-STAGE MODEL; DOMAIN; DIMER; ALAMETHICIN AB The free energy of alpha-helix dimerization of the transmembrane (TM) region of glycophorin A was estimated from a 125-ns molecular dynamics (MID) simulation in a membrane mimetic. The free energy profile was obtained by allowing the TM helical segments to diffuse reversibly along the reaction pathway. Partition of the potential of mean force into free energy components illuminates the critical steps of alpha-helix recognition and association. At large separations, the TM segments are pushed together by the solvent, allowing initial, but not necessarily native, interhelical interactions to occur. This early recognition stage precedes the formation of native contacts, which is accompanied by a tilt of the helices, characteristic of the dimeric structure. This step is primarily driven by the van der Waals helix-helix interactions. Free energy perturbation calculations of the L75A and I76A point mutations reveal a disruption in helix-helix association due to a loss of favorable dispersion interactions. Additional MID simulations of the native TM dimer and of a single alpha-helix confirm that, prior to association, individual alpha-helices are independently stable, in agreement with the "two-stage" model of integral membrane protein folding. C1 Univ Henri Poincare, Inst Nanceien Chim Mol, CNRS, UMR 7565,Equipe Dynam Assemblages Membranaires, F-54506 Vandoeuvre Les Nancy, France. NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. RP Chipot, C (reprint author), Univ Henri Poincare, Inst Nanceien Chim Mol, CNRS, UMR 7565,Equipe Dynam Assemblages Membranaires, BP 239, F-54506 Vandoeuvre Les Nancy, France. EM Christophe.Chipot@edam.uhp-nancy.fr RI Henin, Jerome/A-7080-2008 OI Henin, Jerome/0000-0003-2540-4098 NR 53 TC 99 Z9 100 U1 1 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUN 15 PY 2005 VL 127 IS 23 BP 8478 EP 8484 DI 10.1021/ja050581y PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 935AM UT WOS:000229751100056 PM 15941282 ER PT J AU Johnson, WR Wilson, DW Bearman, G AF Johnson, WR Wilson, DW Bearman, G TI All-reflective snapshot hyperspectral imager for ultraviolet and infrared applications SO OPTICS LETTERS LA English DT Article ID TOMOGRAPHY IMAGING SPECTROMETER; SIMULTANEOUS ACQUISITION; INFORMATION; DEVICE AB Snapshot hyperspectral imaging simultaneously acquires spatial and spectral information about a scene. We report on the first, to our knowledge, all-reflective snapshot hyperspectral imager in the form of a computed tomography imaging spectrometer (CTIS). The reflective design allows for instrument simplicity for applications in the ultraviolet and infrared. To realize a CTIS in a reflective Offner configuration, a reflective two-dimensional computer-generated hologram grating is fabricated on a convex spherical substrate by direct-write electron-beam lithography. Furthermore, a reconfigurable reflective field stop is implemented with a micromirror array to provide high-contrast spatial-spectral filtering, region-of-interest selection, and spatial structure formation. (c) 2005 Optical Society of America C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnson, WR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM william.rjohnson@jpl.nasa.gov NR 17 TC 12 Z9 18 U1 0 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 JUN 15 PY 2005 VL 30 IS 12 BP 1464 EP 1466 DI 10.1364/OL.30.001464 PG 3 WC Optics SC Optics GA 934EJ UT WOS:000229689400012 PM 16007775 ER PT J AU Pizem, H Gershevitz, O Goffer, Y Frimer, AA Sukenik, CN Sampathkumaran, U Milhet, X McIlwain, A De Guire, MR Meador, MAB Sutter, JK AF Pizem, H Gershevitz, O Goffer, Y Frimer, AA Sukenik, CN Sampathkumaran, U Milhet, X McIlwain, A De Guire, MR Meador, MAB Sutter, JK TI Titania deposition on PMR-15 SO CHEMISTRY OF MATERIALS LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; OXIDE THIN-FILMS; LIQUID-PHASE DEPOSITION; LOW-TEMPERATURE SYNTHESIS; END-CAPPED POLYIMIDES; SURFACE-MODIFICATION; AQUEOUS-SOLUTION; ANATASE TIO2; COMPLEXES; POLYMERS AB The formation, degree of crystallinity, and adherence of dense titania (TiO2) thin film coatings on a high-ternperature polyimide resin (PMR-15) can be influenced by the chemical composition of the polymer surface. Furthermore, solution deposition conditions can be adjusted to provide additional control over the morphology and crystallinity of the titania films. Recipes for solution-based titania deposition that used a slowly hydrolyzing titanium fluoride salt in the presence of boric acid as a fluoride scavenger allowed growth of films up to 750 nm thick in 22 h. By adjusting solution pH and temperature, either amorphous titania or oriented crystalline anatase films could be formed. Surface sulfonate groups enhance the adhesion of solution-deposited oxide thin film coatings. While most sulfonation procedures severely damaged the PMR-15 surface, the use of chlorosulfonic acid followed by hydrolysis of the installed chlorosulfonyl groups provided effective surface sulfonation without significant surface damage. In some cases, the oxide deposition solution caused partial hydrolysis of the polymer surface, which itself was sufficient to allow adhesion of the titania film through chelation of titanium ions by exposed benzoic acid groups on the polymer surface. C1 Bar Ilan Univ, Dept Chem, IL-52900 Ramat Gan, Israel. Case Western Reserve Univ, Dept Mat Sci & Engn, Cleveland, OH 44106 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Sukenik, CN (reprint author), Bar Ilan Univ, Dept Chem, IL-52900 Ramat Gan, Israel. EM sukenc@mail.biu.ac.il OI Meador, Mary Ann/0000-0003-2513-7372 NR 55 TC 17 Z9 17 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN 14 PY 2005 VL 17 IS 12 BP 3205 EP 3213 DI 10.1021/cm047962f PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 934VO UT WOS:000229737300023 ER PT J AU Irie, H Sudo, K Akimoto, H Richter, A Burrows, JP Wagner, T Wenig, M Beirle, S Kondo, Y Sinyakov, VP Goutail, F AF Irie, H Sudo, K Akimoto, H Richter, A Burrows, JP Wagner, T Wenig, M Beirle, S Kondo, Y Sinyakov, VP Goutail, F TI Evaluation of long-term tropospheric NO2 data obtained by GOME over East Asia in 1996-2002 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OZONE MONITORING EXPERIMENT; NITROGEN-DIOXIDE; RETRIEVAL; EMISSIONS; MODEL AB Long-term tropospheric nitrogen dioxide (NO2) column data obtained by the Global Ozone Monitoring Experiment (GOME) (G-NO2) are evaluated to confirm the trends found in tropospheric NO2 abundances over East Asia between 1996 and 2002. For three locations in Central and East Asia, the G-NO2 values are compared with tropospheric columns estimated from coincident observations of total NO2 by ground-based UV/visible spectrometers and stratospheric NO2 by satellite solar occultation sensors (E-NO2). The comparisons show a slight linear drift in G-NO2 data from 1996 to 2002. However, it is much smaller than the standard deviation of the differences between G-NO2 and E-NO2 and much smaller than the increasing trends in NO2 seen by GOME over the industrial areas of China, demonstrating the validity of the trends estimated using the GOME data. C1 Japan Agcy Marine Earth Sci & Technol, Frontier Res Ctr Global Change, Kanazawa Ku, Yokohama, Kanagawa 2360001, Japan. Univ Bremen, Inst Environm Physlicy, D-28334 Bremen, Germany. Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Kyrgyz Natl Univ, Bishkek 720033, Kyrgyzstan. CNRS, Serv Aeron, F-91371 Verrieres Le Buisson, France. RP Irie, H (reprint author), Japan Agcy Marine Earth Sci & Technol, Frontier Res Ctr Global Change, Kanazawa Ku, 3173-25 Showa Machi, Yokohama, Kanagawa 2360001, Japan. EM irie@jamstec.go.jp RI Richter, Andreas/C-4971-2008; Kondo, Yutaka/D-1459-2012; Wenig, Mark/K-7279-2012; Burrows, John/B-6199-2014 OI Richter, Andreas/0000-0003-3339-212X; Burrows, John/0000-0002-6821-5580 NR 14 TC 42 Z9 47 U1 3 U2 7 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 JUN 14 PY 2005 VL 32 IS 11 AR L11810 DI 10.1029/2005GL022770 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 938FR UT WOS:000229985800004 ER PT J AU Pfister, G Hess, PG Emmons, LK Lamarque, JF Wiedinmyer, C Edwards, DP Petron, G Gille, JC Sachse, GW AF Pfister, G Hess, PG Emmons, LK Lamarque, JF Wiedinmyer, C Edwards, DP Petron, G Gille, JC Sachse, GW TI Quantifying CO emissions from the 2004 Alaskan wildfires using MOPITT CO data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRACE GASES; ASSIMILATION; ALGORITHM; POLLUTION; PROFILES AB We present an inverse model analysis to quantify the emissions of wildfires in Alaska and Canada in the summer of 2004 using carbon monoxide (CO) data from the Measurements of Pollution in the Troposphere (MOPITT) remote sensing instrument together with the chemistry transport model MOZART ( Model for Ozone and Related Chemical Tracers). We use data assimilation outside the region of the fires to optimally constrain the CO background level and the transport into that region. Inverse modeling is applied locally to quantify the fire emissions. Our a posteriori estimate of the wildfire emissions gives a total of 30 +/- 5 Tg CO emitted during June - August 2004 which is of comparable order to the anthropogenic emissions for the continental US. The simulated CO fields have been evaluated by comparison with MOPITT and independent aircraft data. C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. Natl Ctr Atmospher Res, Adv Study Program, Boulder, CO 80307 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Natl Ctr Atmospher Res, Div Atmospher Chem, POB 3000, Boulder, CO 80307 USA. EM pfister@ucar.edu RI Pfister, Gabriele/A-9349-2008; Lamarque, Jean-Francois/L-2313-2014; Hess, Peter/M-3145-2015; Emmons, Louisa/R-8922-2016 OI Lamarque, Jean-Francois/0000-0002-4225-5074; Hess, Peter/0000-0003-2439-3796; Emmons, Louisa/0000-0003-2325-6212 NR 21 TC 121 Z9 121 U1 0 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 JUN 14 PY 2005 VL 32 IS 11 AR L11809 DI 10.1029/2005GL022995 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 938FR UT WOS:000229985800006 ER PT J AU Liu, L Mishchenko, MI AF Liu, L Mishchenko, MI TI Effects of aggregation on scattering and radiative properties of soot aerosols SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LIGHT-SCATTERING; EXTINCTION COEFFICIENT; SPHERE CLUSTERS; SOUTHERN AFRICA; T-MATRIX; PARTICLES; MORPHOLOGY; CLIMATE AB The superposition T-matrix method is used to compute the scattering matrix elements and optical cross sections for a wide variety of fractal-like soot aggregates in random orientation at a visible wavelength 0.628 mu m. The effects of the fractal dimension and prefactor, the monomer radius, the number of monomers in the aggregate, and the refractive index on light scattering and absorption by aggregated soot particles are analyzed. It is shown that the configuration of the monomers can have a substantial effect and that aggregation can result in a significant enhancement of extinction and scattering relative to those computed from the Lorenz-Mie theory, assuming that there are no electromagnetic interactions between the monomers. Thus one must take the effects of soot agglomeration and cluster morphology into account in radiative transfer modeling and remote sensing applications. C1 Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Liu, L (reprint author), Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. EM mmishchenko@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 NR 36 TC 61 Z9 63 U1 7 U2 21 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 JUN 14 PY 2005 VL 110 IS D11 AR D11211 DI 10.1029/2004JD005649 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 938GV UT WOS:000229988800009 ER PT J AU Ruzmaikin, A Feynman, J Jiang, X Yung, YL AF Ruzmaikin, A Feynman, J Jiang, X Yung, YL TI Extratropical signature of the quasi-biennial oscillation SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GLOBAL QBO; OBSERVATIONAL EVIDENCE; ARCTIC OSCILLATION; MIDDLE ATMOSPHERE; CIRCULATION; OZONE; STRATOSPHERE; VARIABILITY; MODEL; REEXAMINATION AB Using the assimilated data from the National Centers for Environmental Prediction (NCEP) reanalysis, we show that the extratropical signature of the tropical quasi-biennial oscillation (QBO) is seen mostly in the North Annular Mode (NAM) of atmospheric variability. To understand the extratropical manifestation of the QBO, we discuss two effects that have been suggested earlier: (1) The extratropical circulation is driven by the QBO modulation of the planetary wave flux, and (2) the extratropical circulation is driven by the QBO-induced meridional circulation. We found that the first effect is seen in wave 1 in the beginning of winter and in wave 2 in the end of winter. The QBO-induced circulation affects midlatitude regions over the entire winter. To investigate the QBO-NAM coupling, we use an equation that relates the stream function of the meridional circulation and the polar cap averaged temperature, which is a proxy for the NAM index. In addition to the annual Omega(a) and the QBO frequency Omega(Q) the spectrum of its solutions indicates the satellite frequencies at Omega(a) +/- Omega(Q). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Dept Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Ruzmaikin, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM aruzmaik@pop.jpl.nasa.gov NR 29 TC 30 Z9 30 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 JUN 14 PY 2005 VL 110 IS D11 AR D11111 DI 10.1029/2004JD005382 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 938GV UT WOS:000229988800003 ER PT J AU Zhang, MH Klein, S Randall, D Cederwall, R Del Genio, A AF Zhang, MH Klein, S Randall, D Cederwall, R Del Genio, A TI Introduction to special section on toward reducing cloud-climate uncertainties in atmospheric general circulation models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material ID FEEDBACK C1 SUNY Stony Brook, Inst Terr & Planetary Atmospheres, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Zhang, MH (reprint author), SUNY Stony Brook, Inst Terr & Planetary Atmospheres, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. EM mzhang@notes.cc.sunysb.edu RI Del Genio, Anthony/D-4663-2012; Klein, Stephen/H-4337-2016 OI Del Genio, Anthony/0000-0001-7450-1359; Klein, Stephen/0000-0002-5476-858X NR 8 TC 3 Z9 3 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 JUN 14 PY 2005 VL 110 IS D15 AR D15S01 DI 10.1029/2005JD005923 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 938HG UT WOS:000229989900001 ER PT J AU Maune, B Witzens, J Jones, TB Kolodrubetz, M Atwater, H Scherer, A Hagen, R Qiu, YM AF Maune, B Witzens, J Jones, TB Kolodrubetz, M Atwater, H Scherer, A Hagen, R Qiu, YM TI Optically triggered Q-switched photonic crystal laser SO OPTICS EXPRESS LA English DT Article ID LIQUID-CRYSTAL; PHOTOADDRESSABLE POLYMERS; SINGLE-DEFECT; BAND; NANOCAVITY; EMISSION; ALIGNMENT; VACUUM; FILMS AB An optically triggered liquid crystal infiltrated Q-switched photonic crystal laser is demonstrated. A photonic crystal laser cavity was designed and fabricated to support two orthogonally polarized high-Q cavity modes after liquid crystal infiltration. By controlling the liquid crystal orientation via a layer of photoaddressable polymer and a writing laser, the photonic crystal lasing mode can be reversibly switched between the two modes which also switches the laser's emission polarization and wavelength. The creation of the Q-switched laser demonstrates the benefits of customizing photonic crystal cavities to maximally synergize with an infiltrated material and illustrates the potential of integrating semiconductor nanophotonics with optical materials. (C) 2005 Optical Society of America. C1 CALTECH, Dept Elect Engn & Appl Phys, Pasadena, CA 91125 USA. Bayer AG, Cent Res Phys Dept, D-51368 Leverkusen, Germany. CALTECH, Jet Prop Lab, In Situ Technol & Expt Syst Sect, Pasadena, CA 91109 USA. RP Maune, B (reprint author), CALTECH, Dept Elect Engn & Appl Phys, Pasadena, CA 91125 USA. EM bmaune@caltech.edu RI Witzens, Jeremy/I-2579-2012 OI Witzens, Jeremy/0000-0002-2896-7243 NR 30 TC 38 Z9 38 U1 1 U2 8 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 JUN 13 PY 2005 VL 13 IS 12 BP 4699 EP 4707 DI 10.1364/OPEX.13.004699 PG 9 WC Optics SC Optics GA 935RK UT WOS:000229799200037 PM 19495386 ER PT J AU Eastwood, JP Sibeck, DG Slavin, JA Goldstein, ML Lavraud, B Sitnov, M Imber, S Balogh, A Lucek, EA Dandouras, I AF Eastwood, JP Sibeck, DG Slavin, JA Goldstein, ML Lavraud, B Sitnov, M Imber, S Balogh, A Lucek, EA Dandouras, I TI Observations of multiple X-line structure in the Earth's magnetotail current sheet: A Cluster case study SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAGNETIC-FLUX ROPES; PLASMA SHEET; GEOTAIL OBSERVATIONS; COLLISIONLESS RECONNECTION; SUBSTORMS; FLOWS; MODEL; FIELD AB Observations of the Earth's magnetotail made by the four Cluster spacecraft on October 2 2003 are presented. Multi-spacecraft analysis is used to show that the variations in field and flow observed in the vicinity of the magnetotail current sheet are most consistent with a series of two active reconnection sites bounding an Earthward moving flux rope. We demonstrate that a single spacecraft analysis of the same data leads to the incorrect conclusion that a single X-line is moving tailward. The implications of this in relation to the interpretation of single spacecraft observations are outlined. These results show that reconnection can occur simultaneously at different points in the near-Earth magnetotail current sheet, providing ( further) important experimental validation of multiple X - line reconnection theories on the mesoscale ( tens of ion inertial length) level. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Maryland, Inst Res Elect & Appl Phys, College Pk, MD 20742 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BW, England. Univ Toulouse 3, CNRS, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. RP Eastwood, JP (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM jonathan.p.eastwood@gsfc.nasa.gov RI Sibeck, David/D-4424-2012; Goldstein, Melvyn/B-1724-2008; Slavin, James/H-3170-2012; Sitnov, Mikhail/H-2316-2016 OI Slavin, James/0000-0002-9206-724X; NR 27 TC 76 Z9 80 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 JUN 11 PY 2005 VL 32 IS 11 AR L11105 DI 10.1029/2005GL022509 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 937YP UT WOS:000229964300003 ER PT J AU Hakkinen, S Cavalieri, DJ AF Hakkinen, S Cavalieri, DJ TI Sea ice drift and its relationship to altimetry-derived ocean currents in the Labrador Sea SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VARIABILITY; RECORD AB Low frequency sea ice drift variability and its oceanic and atmospheric forcing are investigated for the Labrador Sea over the period 1979 - 2002. Our objective is to separate the ocean forced component of ice drift in order to corroborate the changes in the subpolar gyre circulation found by Hakkinen and Rhines ( 2004). The atmospheric and oceanic forcing components can be approximately separated by comparing the time series resulting from an Empirical Orthogonal Function (EOF) analysis of sea ice motion with local sea level pressure gradients and altimetry-derived oceanic velocities. The first ice motion EOF is found to be associated with wind driven ice drift. The second mode is associated with oceanic forcing, because its time series is similar in its fluctuations to the oceanic velocities derived from altimetry. These two data sets confirm a major weakening of the subpolar ocean circulation between the early 1990s and the latter 1990s. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM sipa.hakkinen@nasa.gov RI Hakkinen, Sirpa/E-1461-2012 NR 6 TC 3 Z9 3 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 JUN 11 PY 2005 VL 32 IS 11 AR L11609 DI 10.1029/2005GL022682 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 937YP UT WOS:000229964300004 ER PT J AU Gurgiolo, C Goldstein, ML Narita, Y Glassmeier, KH Fazakerley, AN AF Gurgiolo, C Goldstein, ML Narita, Y Glassmeier, KH Fazakerley, AN TI A phase locking mechanism for nongyrotropic electron distributions upstream of the Earth's bow shock SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GYROPHASE BUNCHED IONS; WHISTLER WAVES; FREQUENCY WAVES; CLUSTER; FORESHOCK AB [1] Observations of nongyrotropic electron distributions in the region upstream of the Earth's bow shock suggest that there exists a mechanism to lock in their phase, otherwise they would rapidly gyrophase mix into a ring-beam distribution. Measurements by the Plasma Electron and Current Experiment ( PEACE) on the Cluster spacecraft have provided a way of determining the rotational period of a nongyrotropic electron distribution. For the time period studied, the rotational period is found to be approximate to 0.5 Hz, significantly lower than the local Larmor frequency but in line with the frequency of waves observed in the local magnetic field. Detailed wave analysis has revealed that the waves are most likely ordinary right-hand whistler waves. The conclusion is that the waves provide the necessary phase locking mechanism. It is not clear whether those waves are generated by the nongyrotropic distribution or are produced by other means and then cause the observed nongyrotropy. C1 Bitterroot Basic Res Inc, Hamilton, MT 59840 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Tech Univ Braunschweig, Inst Geophys & Extraterr, D-38106 Braunschweig, Germany. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. RP Gurgiolo, C (reprint author), Bitterroot Basic Res Inc, 837 Westside Rd, Hamilton, MT 59840 USA. EM chris@gurgiolo.com; melvyn.l.goldstein@nasa.gov; y.narita@tu-bs.de; kh.glassmeier@tu-bs.de; anf@mssl.udf.ac.uk RI Goldstein, Melvyn/B-1724-2008 NR 19 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-SPACE JI J. Geophys. Res-Space Phys. PD JUN 11 PY 2005 VL 110 IS A6 AR A06206 DI 10.1029/2005JA011010 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 937ZF UT WOS:000229966500007 ER PT J AU Roberts, DA Keiter, PA Goldstein, ML AF Roberts, DA Keiter, PA Goldstein, ML TI Origin and dynamics of the heliospheric streamer belt and current sheet SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND; CORONAL STREAMERS; VOYAGER-2 OBSERVATIONS; MAGNETIC-FIELD; MHD TURBULENCE; PLASMA SHEET; EVOLUTION; FLUCTUATIONS; SIMULATION AB [ 1] The broad high-density, low-temperature region around the thin heliospheric current sheet at solar minimum forms a relatively stable "streamer belt'' associated with the slow wind flow. This region contains highly structured magnetic fields, with large rotations and discontinuities being common. This observational study examines the likely origins and dynamics of the interplanetary plasma and current sheets primarily using Helios data. The striking differences sometimes observed between the plasma on the two sides of the current sheet support the common interpretation that the plasma above and below the sheet comes from often very different regions located either side of the helmet streamer at the base of the slow wind flow. The entropy per proton in the streamer belt often shows sharply defined regions of strongly different plasma; this implies that the origin of the filamentary structure is in initial conditions near the Sun because dynamical evolution can only equalize entropy. The observed large relative density and other fluctuations may thus represent the conditions on flow tubes with different boundary conditions. The average entropy in the streamer belt increases by about the same factor as in the surrounding high-speed streams, indicating that this region is heated substantially, consistent with studies of the temperature evolution and with turbulence modeling. Compressive stream interaction regions are not preferentially heated ( in the sense of an entropy increase) in the inner heliosphere. Strong anticorrelations between density and both temperature and magnetic field magnitude are observed within the streamer belt but not in the surrounding regions, and these become weaker as the flow moves outward. Both the smoother appearance of the entropy at greater heliocentric distance and simulation evidence support the view that the streamer belt region undergoes significant dynamical evolution. This evolution seems to also affect the current sheet because sector boundary crossings are observed to become more complex ( more multiple crossings) with increasing heliocentric distance. The crossings are more complex in general near solar maximum, although the complexity still increases with radial distance. C1 NASA, Goddard Space Flight Ctr, Lab Solar & Space Phys, Greenbelt, MD 20771 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. RP Roberts, DA (reprint author), NASA, Goddard Space Flight Ctr, Lab Solar & Space Phys, Code 612-2, Greenbelt, MD 20771 USA. EM aaron.roberts@gsfc.nasa.gov; pkeiter@lanl.gov; melvyn.l.goldstein@nasa.gov RI Roberts, Dana/D-4625-2012; Goldstein, Melvyn/B-1724-2008; Keiter, Paul/J-3037-2013 NR 27 TC 10 Z9 10 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 JUN 11 PY 2005 VL 110 IS A6 AR A06102 DI 10.1029/2004JA010541 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 937ZF UT WOS:000229966500001 ER PT J AU Slavin, JA Tanskanen, EI Hesse, M Owen, CJ Dunlop, MW Imber, S Lucek, EA Balogh, A Glassmeier, KH AF Slavin, JA Tanskanen, EI Hesse, M Owen, CJ Dunlop, MW Imber, S Lucek, EA Balogh, A Glassmeier, KH TI Cluster observations of traveling compression regions in the near-tail SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETIC-FLUX ROPES; BURSTY BULK FLOWS; PLASMA SHEET; GEOTAIL OBSERVATIONS; EARTHS MAGNETOTAIL; MAGNETOSPHERIC SUBSTORMS; KINETIC-PROPERTIES; GEOMAGNETIC TAIL; MHD SIMULATIONS; TRANSFER EVENTS AB [1] Examination of Cluster measurements has revealed the presence of traveling compression regions (TCRs) in the lobes of the Earth's magnetotail at X similar to - 11 - 19 R(E). These TCRs strongly resemble those observed in the more distant tail, but their mean duration is only similar to 35 s as compared with similar to 160 s for the TCRs in the distant tail. Furthermore, the B(z) variations associated with the Cluster TCRs were found to be south-then-north (SN) in 80% of the cases as opposed to the north-then-south (NS) polarity that is dominant beyond X similar to - 30 R(E). Analysis of the time of arrival of the TCRs at the different Cluster spacecraft showed that all of the SN TCRs propagate earthward while all of the NS TCRs, as expected, move tailward. The mean speeds of the SN and NS TCRs were essentially the same, 849 km/s and 821 km/s, respectively, and their average width was 4.3 R(E). Some examples of near-periodic, multiple TCR events with separations between individual TCRs comparable to their width were also observed, suggestive of multiple X-line reconnection or periodic impulsive reconnection. However, the most probable separation observed during multi-TCR events was larger, similar to 100 - 150 s. The TCR minimum variance eigenvectors have a strong tendency to lie parallel to the GSM XY plane, but they exhibit a wide range of orientations within that plane. Examined as a function of the Y(GSM), there are broad maxima in occurrence frequency, width, and speed of TCRs on the duskside of the tail. Superposed epoch analysis of the Kyoto World Data Center Quick Look AL Index relative to the time of TCR occurrence shows that the compression regions tend to be observed during the expansion phase of substorms. Finally, the origins of the traveling compression regions in the near-tail are discussed in terms of the effects of magnetic flux rope motion and impulsive reconnection. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ London Imperial Coll Sci & Technol, London W72BZ, England. Tech Univ Braunschweig, Inst Geophys & Extraterr Phys, D-38106 Braunschweig, Germany. RP Slavin, JA (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. EM jslavin@pop600.gsfc.nasa.gov RI Owen, Christopher/C-2999-2008; Hesse, Michael/D-2031-2012; Slavin, James/H-3170-2012 OI Owen, Christopher/0000-0002-5982-4667; Slavin, James/0000-0002-9206-724X NR 57 TC 57 Z9 58 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 JUN 11 PY 2005 VL 110 IS A6 AR A06207 DI 10.1029/2004JA010878 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 937ZF UT WOS:000229966500005 ER PT J AU Cleary, KA Taylor, AC Waldram, E Battye, RA Dickinson, C Davies, RD Davis, RJ Genova-Santos, R Grainge, K Jones, ME Kneissl, R Pooley, GG Rebolo, R Rubino-Martin, JA Saunders, RDE Scott, PF Slosar, A Titterington, D Watson, RA AF Cleary, KA Taylor, AC Waldram, E Battye, RA Dickinson, C Davies, RD Davis, RJ Genova-Santos, R Grainge, K Jones, ME Kneissl, R Pooley, GG Rebolo, R Rubino-Martin, JA Saunders, RDE Scott, PF Slosar, A Titterington, D Watson, RA TI Source subtraction for the extended Very Small Array and 33-GHz source count estimates SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE surveys; cosmic microwave background; radio continuum : galaxies ID BACKGROUND POWER SPECTRUM; COSMIC-ANISOTROPY-TELESCOPE; RADIO-SOURCES; EXTRAGALACTIC SOURCES; PLANCK SURVEYOR; HIGH-FREQUENCY; 15 GHZ; IMAGER; PREDICTIONS; SKY AB We describe the source subtraction strategy and observations for the extended Very Small Array (VSA), a cosmic microwave background interferometer operating at 33 GHz. A total of 453 sources were monitored at 33 GHz using a dedicated source subtraction baseline. 131 sources brighter than 20 mJy were directly subtracted from the VSA visibility data. Some characteristics of the subtracted sources, such as spectra and variability, are discussed. The 33-GHz source counts are estimated from a sample selected at 15 GHz. The selection of VSA fields in order to avoid bright sources introduces a bias into the observed counts. This bias is corrected and the resulting source count is estimated to be complete in the flux-density range 20-114 mJy. The 33-GHz source counts are used to calculate a correction to the VSA power spectrum for sources below the subtraction limit. C1 Univ Manchester, Jodrell Bank Observ, Macclesfield SK11 9DL, Cheshire, England. Univ Cambridge, Cavendish Lab, Astrophys Grp, Cambridge CB3 0HE, England. Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Tenerife, Spain. RP Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Kieran.A.Cleary@jpl.nasa.gov OI Rubino-Martin, Jose Alberto/0000-0001-5289-3021; Watson, Robert/0000-0002-5873-0124 NR 33 TC 33 Z9 34 U1 0 U2 0 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 JUN 11 PY 2005 VL 360 IS 1 BP 340 EP 353 DI 10.1111/j.1365-2966.2005.09037.x PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 937ET UT WOS:000229908100030 ER PT J AU O'Brien, PT Reeves, JN Simpson, C Ward, MJ AF O'Brien, PT Reeves, JN Simpson, C Ward, MJ TI The connection between ultraviolet and X-ray outflows in active galactic nuclei: the case of PDS 456 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : active; galaxies : individual : PDS 456; ultraviolet : galaxies ID BROAD ABSORPTION-LINE; QUASI-STELLAR OBJECTS; VELOCITY IONIZED OUTFLOW; ACCRETION DISK WINDS; EMISSION-LINE; LUMINOUS QUASAR; PDS 456; CONTINUUM; GALAXY; QSOS AB High-velocity outflows from active galactic nuclei are a well-known phenomenon in terms of the broad absorption lines seen in the ultraviolet/optical. More recently, similar, possibly related, outflows have been reported in the X-ray. The most extreme example is seen in the nearby, luminous QSO PDS 456, which displays a massive, high-velocity (50 000 km s(-1)), high-ionization X-ray outflow of 10 M circle dot yr(-1). Here we present the ultraviolet spectrum of PDS 456 as observed by the Hubble Space Telescope. We find that the ultraviolet spectrum is also extreme, displaying very broad emission lines, with C ivlambda1549 blueshifted by 5000 km s(-1) and a broad Ly alpha absorption trough blueshifted by 14 000-24 000 km s(-1). No strong, broad high-ionization absorption features are seen. We interpret the combined ultraviolet and X-ray spectrum of PDS 456 as the signature of a decelerating, cooling outflow, which may be driven by radiation and/or magnetic field. This outflow may be the source of some of the broad emission- and absorption-line gas. C1 Univ Leicester, Dept Phys & Astron, X Ray & Observat Astron Grp, Leicester LE1 7RH, Leics, England. NASA, Goddard Space Flight Ctr, Lab High Energy Astrophys, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Durham, Dept Phys, Sci Labs, Durham DH1 3LE, England. RP Univ Leicester, Dept Phys & Astron, X Ray & Observat Astron Grp, Leicester LE1 7RH, Leics, England. EM pto@star.le.ac.uk NR 31 TC 18 Z9 18 U1 0 U2 0 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 JUN 11 PY 2005 VL 360 IS 1 BP L25 EP L29 DI 10.1111/j.1745-3933.2005.00038.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 937ET UT WOS:000229908100042 ER PT J AU Samoilova, SV Balin, YS Krekova, MM Winker, DM AF Samoilova, SV Balin, YS Krekova, MM Winker, DM TI Method for reconstructing atmospheric optical parameters from the data of polarization lidar sensing SO APPLIED OPTICS LA English DT Article ID AEROSOL EXTINCTION PROFILES; MULTIPLE-SCATTERING; SPACEBORNE LIDAR; CIRRUS CLOUDS; RETURNS; EQUATION; RATIOS AB Inversion of polarization lidar sensing data based on the form of the lidar sensing equation with allowance for contributions from multiple-scattering calls for a priori information on the scattering phase matrix. In the present study the parameters of the Stokes vectors for various propagation media, including those with the scattering phase matrices that vary along the measuring range, are investigated. It is demonstrated that, in spaceborne lidar sensing, a simple parameterization of the multiple-scattering contribution is applicable and the polarization signal's characteristics depend mainly on the lidar and depolarization ratios, whereas differences in the angular dependences of the matrix components are no longer determining factors. An algorithm for simultaneous reconstruction of the profiles of the backscattering coefficient and depolarization and lidar ratios in an inhomogeneous medium is suggested. Specific features of the methods are analyzed for the examples of interpretation of lidar signal profiles calculated by the Monte Carlo method and are measured experimentally. (c) 2005 Optical Society of America C1 Russian Acad Sci, Inst Atmospher Opt, Siberian Branch, Tomsk 634055, Russia. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Samoilova, SV (reprint author), Russian Acad Sci, Inst Atmospher Opt, Siberian Branch, I Academicheskii Ave, Tomsk 634055, Russia. EM balin@iao.ru NR 35 TC 3 Z9 4 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 JUN 10 PY 2005 VL 44 IS 17 BP 3499 EP 3509 DI 10.1364/AO.44.003499 PG 11 WC Optics SC Optics GA 934PF UT WOS:000229720000016 PM 16007848 ER PT J AU Matsumoto, T Matsuura, S Murakami, H Tanaka, M Freund, M Lim, M Cohen, M Kawada, M Noda, M AF Matsumoto, T Matsuura, S Murakami, H Tanaka, M Freund, M Lim, M Cohen, M Kawada, M Noda, M TI Infrared telescope in space observations of the near-infrared extragalactic background light SO ASTROPHYSICAL JOURNAL LA English DT Article DE diffuse radiation; infrared : general ID INTERPLANETARY DUST CLOUD; POWER SPECTRUM ANALYSIS; EXPERIMENT SEARCH; SKY BRIGHTNESS; SUBMILLIMETER GALAXIES; TENTATIVE DETECTION; GALACTIC EMISSION; NUMBER COUNTS; DEEP FIELD; IN-SPACE AB We have searched for near-infrared extragalactic background light (EBL) in the data from the Near-Infrared Spectrometer (NIRS) on the Infrared Telescope in Space (IRTS). After subtracting the contribution of faint stars and the zodiacal component based on modeling, a significant isotropic emission is obtained in the wavelength bands from 1.4 to 4.0 mu m. The spectrum is stellar-like but shows a spectral jump from the optical EBL. The emission obtained is isotropic over the observed sky, and the in-band flux amounts to similar to 35 nW m(-2) sr(-1), which is too bright to be explained by the integrated light from faint galaxies. Analyses of COBE DIRBE data, after removal of starlight, show essentially the same result within the uncertainty in the zodiacal light model, which implies that the isotropic emission observed by IRTS NIRS is of extragalactic origin. Significant fluctuations in sky brightness were also detected that cannot be explained by fluctuations due to faint stars, zodiacal components, and normal galaxies. The excess fluctuation amounts to similar to 1/4 of the excess emission over the integrated light of galaxies and is consistent with fluctuations observed by COBE DIRBE. A two-point correlation analysis shows that IRTS NIRS data have an angular scale of fluctuations of a few degrees. The spectrum and brightness of the observed excess EBL emission could be explained by the redshifted UV radiation from the first generation of massive stars (Population III stars), which caused the reionization of the universe. Recent Wilkinson Microwave Anisotropy Probe (WMAP) observations of the cosmic microwave background (CMB) polarization have indicated that reionization occurred at z similar to 17 or earlier, while the spectral jump around 1 mu m in the observed excess EBL suggests that the Population III star formation terminated at z similar to 9. The observed fluctuations, however, are considerably larger than the theoretical predictions for the Population III stars. C1 Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. Nagoya Univ, Dept Phys, Chikusa Ku, Nagoya, Aichi 4648602, Japan. Nagoya Sci Museum, Naka Ku, Nagoya, Aichi 4530037, Japan. NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. USAF, Res Lab, Electron Devices Branch, Sensors Directorate,AFRL SNDD, Wright Patterson AFB, OH 45433 USA. Natl Astron Observ Japan, Tokyo, Japan. RP Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, 3-1-1 Yoshinodai, Kanagawa 2298510, Japan. RI Matsuura, Shuji/B-5658-2016 OI Matsuura, Shuji/0000-0002-5698-9634 NR 55 TC 128 Z9 128 U1 1 U2 7 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 JUN 10 PY 2005 VL 626 IS 1 BP 31 EP 43 DI 10.1086/429383 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 932CQ UT WOS:000229532200003 ER PT J AU Farrah, D Surace, JA Veilleux, S Sanders, DB Vacca, WD AF Farrah, D Surace, JA Veilleux, S Sanders, DB Vacca, WD TI Space telescope imaging spectrograph ultraviolet/optical spectroscopy of "warm'' ultraluminous infrared galaxies SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : active; galaxies : interactions; galaxies : nuclei; galaxies : Seyfert; galaxies : starburst; ultraviolet : galaxies ID BROAD ABSORPTION-LINE; QUASI-STELLAR OBJECTS; ACTIVE GALACTIC NUCLEI; WOLF-RAYET GALAXIES; STAR-FORMING GALAXIES; LYMAN-BREAK GALAXIES; DIGITAL SKY SURVEY; EMISSION-LINE; SEYFERT-GALAXIES; IRAS GALAXIES AB We present high spatial resolution ultraviolet and optical spectroscopy, obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, of nuclear structures within four "warm'' ultraluminous infrared galaxies (ULIRGs). We find an active galactic nucleus (AGN) in at least three and probably all four in our sample, hosted in a compact, optically luminous "knot.'' In three cases these knots were previously identified as a putative AGN from multiband optical imaging. Three objects of the sample also harbor a starburst in one or more knots, suggesting that the optically luminous knots seen in local ULIRGs are the most likely sites of the dust-shrouded starburst and AGN activity that power the infrared emission. The four AGNs have a diverse range of properties: two are classical narrow-line AGNs, one shows both broad and narrow lines and evidence for lines of sight from the narrow- to the broad-line regions, and one is plausibly an FeLoBAL AGN. The probable presence in one object of an FeLoBAL AGN, which are extremely rare in the QSO population, supports the idea that LoBAL AGNs may be youthful systems shrouded in gas and dust rather than AGNs viewed along a certain line of sight. The three starbursts for which detailed constraints are possible show a smaller range in properties; all three bursts are young, with two having ages of &SIM; 4 Myr and the third having an age of 20 Myr, suggesting that ULIRGs undergo several bursts of star formation during their lifetimes. None of the starbursts show evidence for initial mass function slopes steeper than about 3.3. The metallicities of the knots for which metallicities can be derived are all at least 1.5 Z(&ODOT;). The properties of one further starburst knot are consistent with it being the forming core of an elliptical galaxy. Our results suggest that detailed studies of the knots seen in ULIRGs can give important insights into the most violent starburst and AGN activity at both low and high redshift. C1 CALTECH, Jet Prop Lab, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. NASA, Ames Res Ctr, SOFIA USRA, Moffett Field, CA 94035 USA. RP Farrah, D (reprint author), CALTECH, Jet Prop Lab, Spitzer Sci Ctr, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 101 TC 34 Z9 34 U1 0 U2 1 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 JUN 10 PY 2005 VL 626 IS 1 BP 70 EP 88 DI 10.1086/428660 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 932CQ UT WOS:000229532200007 ER PT J AU Remijan, AJ Wyrowski, F Friedel, DN Meier, DS Snyder, LE AF Remijan, AJ Wyrowski, F Friedel, DN Meier, DS Snyder, LE TI A survey of large molecules toward the proto-planetary nebula CRL 618 SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : identification; radio lines : stars; stars : AGB and post-AGB; stars : individual (CRL 618) ID MARYLAND-ASSOCIATION ARRAY; VIBRATIONALLY EXCITED HC3N; METHYL CYANIDE; ASTROPHYSICAL INTEREST; ORGANIC-MOLECULES; MICROWAVE-SPECTRA; ACETIC-ACID; FORMIC-ACID; HOT CORES; MILLIMETER AB We present the results of our survey toward the proto-planetary nebula CRL 618 for several large, highly saturated, oxygen-bearing organic molecules of biological importance including acetaldehyde (CH3CHO), acetic acid (CH3COOH), dimethyl ether (CH3OCH3), ethanol (CH3CH2OH), formic acid (HCOOH) and methyl formate (HCOOCH3); large carbon chain molecules including methyl cyanide (CH3CN), methylcyanoacetylene (CH3C3N), cyanoacetylene (HC3N), cyanodiacetylene (HC5N), and C6H; and, finally, smaller molecules including (SO)-S-34, SO2, (OCS)-S-34, and MgNC. No biologically important organic molecules were detected. However, we report the first interferometric detections of CH3CN and vibrationally excited HC3N and HC5N toward this source. The temperature and distribution of CH3CN toward CRL 618 indicates that it is formed in the outer envelope surrounding the ultracompact H II region. Furthermore, the P Cygni line profile and corresponding channel maps of vibrationally excited HC5N support its distribution in the extended envelope expanding radially from the central star. The detection of vibrationally excited HC3N confirmed the temperature structure and column density of HC3N in the inner envelope found by Wyrowski and colleagues. Finally, our observations clearly indicate that CRL 618 is a good source of large carbon chain species but a very poor source for detecting or producing organic species of biological importance. C1 Univ Illinois, Dept Astron, Urbana, IL 61801 USA. Max Planck Inst Radioastron, D-53121 Bonn, Germany. RP Remijan, AJ (reprint author), NASA, Goddard Space Flight Ctr, Earth & Space Data Comp Div, Code 930, Greenbelt, MD 20771 USA. EM aremijan@pop900.gsfc.nasa.gov; wyrowski@mpifr-bonn.mpg.de; friedel@astro.uiuc.edu; meierd@astro.uiuc.edu; snyder@astro.uiuc.edu NR 58 TC 26 Z9 26 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 JUN 10 PY 2005 VL 626 IS 1 BP 233 EP 244 DI 10.1086/429750 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 932CQ UT WOS:000229532200019 ER PT J AU Pravdo, SH Tsuboi, Y AF Pravdo, SH Tsuboi, Y TI X-rays from Cepheus A East and West SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : Herbig-Haro objects; X-rays : ISM ID HERBIG-HARO OBJECTS; STAR-FORMING REGION; YOUNG STELLAR OBJECTS; MOLECULAR CLOUD; RADIO-SOURCES; MASS OUTFLOW; HH OBJECTS; DISCOVERY; CONTINUUM; PROTOSTAR AB We report the discovery of X-rays from both components of Cepheus A, East and West, with the XMM-Newton observatory. HH 168 joins the ranks of other energetic Herbig-Haro objects that are sources of T &GE; 10(6) K X-ray emission. The effective temperature of HH 168 is T = 5.8(-2.3)(+3.5) x 10(6) K, and its unabsorbed luminosity is 1: 1; 10(29) ergs s(-1), making it hotter and less luminous than other representatives of its class. We also detect prominent X-ray emission from the complex of compact radio sources believed to be the power sources for Cep A. We call this source HWX, and it is distinguished by its hard X-ray spectrum, T = 1.2(-0.5)(+1.2) 10(8) K, and its complex spatial distribution. It may arise from one or more protostars associated with the radio complex, the outflows, or a combination of the two. We detect 102 X-ray sources, many presumed to be pre-main-sequence stars on the basis of the reddening of their optical and IR counterparts. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Chuo Univ, Dept Phys, Fac Sci & Engn, Bunkyo Ku, Tokyo 1128551, Japan. RP Pravdo, SH (reprint author), CALTECH, Jet Prop Lab, 306-431,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM spravdo@jpl.nasa.gov; tsuboi@phys.chuo-u.ac.jp NR 44 TC 13 Z9 13 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2005 VL 626 IS 1 BP 272 EP 282 DI 10.1086/429988 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 932CQ UT WOS:000229532200023 ER PT J AU Atteia, JL Kawai, N Vanderspek, R Pizzichini, G Ricker, GR Barraud, C Boer, M Braga, J Butler, N Cline, T Crew, GB Dezalay, JP Donaghy, TQ Doty, J Fenimore, EE Galassi, M Graziani, C Hurley, K Jernigan, JG Lamb, DQ Levine, A Manchanda, R Martel, F Matsuoka, M Morgan, E Nakagawa, Y Olive, JF Prigozhin, G Sakamoto, T Sato, R Shirasaki, Y Suzuki, M Takagishi, K Tamagawa, T Torii, K Villasenor, J Woosley, SE Yamauchi, M Yoshida, A AF Atteia, JL Kawai, N Vanderspek, R Pizzichini, G Ricker, GR Barraud, C Boer, M Braga, J Butler, N Cline, T Crew, GB Dezalay, JP Donaghy, TQ Doty, J Fenimore, EE Galassi, M Graziani, C Hurley, K Jernigan, JG Lamb, DQ Levine, A Manchanda, R Martel, F Matsuoka, M Morgan, E Nakagawa, Y Olive, JF Prigozhin, G Sakamoto, T Sato, R Shirasaki, Y Suzuki, M Takagishi, K Tamagawa, T Torii, K Villasenor, J Woosley, SE Yamauchi, M Yoshida, A TI HETE-2 observation of two gamma-ray bursts at z > 3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts ID HIGH COLUMN DENSITY; 14 DECEMBER 1997; OPTICAL AFTERGLOW; SPECTRAL-ANALYSIS; HOST GALAXY; BEPPOSAX; IDENTIFICATION; GRB-020124; ENERGETICS AB GRB 020124 and GRB 030323 constitute half the sample of gamma-ray bursts (GRBs) with a measured redshift greater than 3. This paper presents the temporal and spectral properties of these two GRBs detected and localized with the High Energy Transient Explorer 2 (HETE-2). While they have nearly identical redshifts (z = 3.20 for GRB 020124 and z = 3.37 for GRB 030323), these two GRBs span about an order of magnitude in fluence, thus sampling distinct regions of the GRB luminosity function. The properties of these two bursts are compared with those of the bulk of the GRB population detected by HETE-2. We also discuss the energetics of GRB 020124 and GRB 030323 and show that they are compatible with the E-p-E-iso relation discovered by Amati et al. Finally, we compute the maximum redshifts at which these bursts could have been detected by HETE-2, and we address various issues connected with the detection and localization of high-z GRBs. C1 Observ Midi Pyrenees, Astrophys Lab, F-31400 Toulouse, France. Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. MIT, Ctr Space Res, Cambridge, MA 02139 USA. INAF IASF, Sez Bologna, I-40129 Bologna, Italy. Observ Haute Provence, CNRS, UPR 9049, F-04870 St Michel, France. Inst Nacl Pesquisas Espaciais, BR-12227010 Sao Jose Dos Campos, Brazil. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Observ Midi Pyrenees, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Tata Inst Fundamental Res, Dept Astron & Astrophys, Bombay 400005, Maharashtra, India. Natl Space Dev Agcy Japan, Tsukuba Space Ctr, Tsukuba, Ibaraki 3058505, Japan. Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 1578572, Japan. Natl Astron Observ, Tokyo 1818588, Japan. Miyazaki Univ, Fac Engn, Miyazaki 8892192, Japan. Osaka Univ, Dept Earth & Space Sci, Grad Sch Sci, Toyonaka, Osaka 5600043, Japan. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. RP Atteia, JL (reprint author), Observ Midi Pyrenees, Astrophys Lab, 14 Ave Edouard Belin, F-31400 Toulouse, France. OI Boer, Michel/0000-0001-9157-4349 NR 26 TC 12 Z9 12 U1 0 U2 1 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 JUN 10 PY 2005 VL 626 IS 1 BP 292 EP 297 DI 10.1086/430057 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 932CQ UT WOS:000229532200025 ER PT J AU Titarchuk, L Shaposhnikov, N AF Titarchuk, L Shaposhnikov, N TI How to distinguish neutron star and black hole X-ray binaries? Spectral index and quasi-periodic oscillation frequency correlation SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; radiation mechanisms : nonthermal; stars : individual (4U 1728-34) ID MONTE-CARLO SIMULATIONS; HIGH-ENERGY SPECTRA; 4U 1728-34; OBSERVATIONAL EVIDENCE; INTRINSIC SIGNATURE; 4U-1728-34 GX-354-0; MASS DETERMINATION; TIMING FEATURES; EVENT HORIZON; POWER-LAW AB Recent studies have revealed strong correlations between frequencies of quasi-periodic oscillations (QPOs) in the range 1-10 Hz and the spectral power-law index of several black hole (BH) candidate sources when seen in the low/hard state, the steep power-law ( soft) state, and in transition between these states. In the soft state these index-QPO frequency correlations show a saturation of the photon index &UGamma; &SIM; 2: 7 at high values of the low frequency v(L). This saturation effect was previously identified as a BH signature. In this paper we argue that this saturation does not occur, at least for one neutron star (NS) source, 4U 1728-34, for which the index &UGamma; monotonically increases with v(L) to values of 6 and higher. We base this conclusion on our analysis of &SIM; 1.5 Ms of Rossi X- Ray Timing Explorer (RXTE) archival data for 4U 1728-34. We reveal the spectral evolution of the Comptonized blackbody spectra when the source transitions from the hard to soft states. The hard state spectrum is a typical thermal Comptonization spectrum of the soft photons that originate in the disk and the NS outer photospheric layers. The hard state photon index is &UGamma; &SIM; 2. The soft state spectrum consists of two blackbody components that are only slightly Comptonized. Thus we can claim ( as expected from theory) that in NS sources thermal equilibrium is established for the soft state. To the contrary in BH sources, the equilibrium is never established because of the presence of the BH horizon. The emergent BH spectrum, even in the high/soft state, has a power-law component. We also identify the low QPO frequency v(L) as a fundamental frequency of the quasi-spherical component of the transition layer v(SL); presumably related to the corona and the NS and disk magnetic closed field lines). The lower frequency v(SL) is identified as the frequency of oscillations of a quasi-cylindrical configuration of the TL ( presumably related to the NS and disk magnetic open field lines). We also show that the strength of Fe Kα line, QPOs, and the link between them does not depend on radio flux in 4U 1728-34. C1 George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. USN, Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RP Titarchuk, L (reprint author), George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. EM ltitarchuk@ssd5.nrl.navy.mil; nikolai@milkyway.gsfc.nasa.gov NR 52 TC 34 Z9 34 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 JUN 10 PY 2005 VL 626 IS 1 BP 298 EP 306 DI 10.1086/429986 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 932CQ UT WOS:000229532200026 ER PT J AU Robin, J Levine, E Riha, S AF Robin, J Levine, E Riha, S TI Utilizing satellite imagery and GLOBE student data to model soil dynamics SO ECOLOGICAL MODELLING LA English DT Article DE SVAT; model; soil moisture; transpiration; NDVI ID DIFFERENCE VEGETATION INDEX; REMOTELY-SENSED DATA; POTENTIAL EVAPORATION; ENERGY FLUXES; SENSING DATA; CLIMATE; TRANSPIRATION; SIMULATION; CROP; PHOTOSYNTHESIS AB General Purpose Atmosphere Plant Soil Simulator (GAPS), a menu-driven soil-vegetation-atmosphere transfer (SVAT) model, was used to simulate soil water dynamics from 1998 through 2001 for Greenville, PA, USA. GLOBE student data collected by students from Reynolds Junior and Senior High School, coupled with normalized difference vegetation index (NDVI) data derived from SPOT4 vegetation imagery, were used to parameterize and validate the model. Data from the National Weather Service Cooperative (NWSC) was used to evaluate the GLOBE dataset. Overall, there was a high index of agreement (d > 0.80) between field measurements and simulated soil water values from both datasets (GLOBE and NWSC). Simulations using the GLOBE climate data outperformed the NWSC data for the 1999, 2000, and 2001 growing seasons. In addition, the GLOBE simulations showed that NDVI could be utilized to predict transpiration periods (QI, QII and QIII) for northern latitudes > 35 degrees with a distinct winter period. In phenological terms, QI reflects the onset of the growing season when vegetation is greening up (NDVI < 0.60) and transpiration is beginning (< 2 mm/day) and QII reflects the end of the growing seasons when vegetation is greening down and transpiration is decreasing. QIII reflects the height of the growing season when transpiration rates average between 2 and 5 nun per day and NDVI is at its maximum (> 0.60). Results of this study demonstrate that GLOBE student data, coupled with remotely sensed data, can provide an important source of input and validation information for capacitance SVAT models such as GAPS. (c) 2004 Elsevier B.V. All rights reserved. C1 Univ Maryland, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. Cornell Univ, Ithaca, NY 14853 USA. RP Robin, J (reprint author), Univ Maryland, College Pk, MD 20742 USA. EM jrobin@ltpmail.gsfc.nasa.gov NR 65 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD JUN 10 PY 2005 VL 185 IS 1 BP 133 EP 145 DI 10.1016/j.ecolmodel.2004.11.022 PG 13 WC Ecology SC Environmental Sciences & Ecology GA 928LM UT WOS:000229273100009 ER PT J AU Farrell, WM Plaut, JJ Gurnett, DA Picardi, G AF Farrell, WM Plaut, JJ Gurnett, DA Picardi, G TI Detecting sub-glacial aquifers in the north polar layered deposits with Mars Express/MARSIS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERE; SUBSURFACE; RADAR AB The penetration of the MARSIS radar signal into the polar ice mass is modeled to determine the capability of the instrument to locate sub-glacial aquifers. As a ground penetrating radar, the orbiting MARSIS transmits a signal > 1 W between 1 - 5 MHz. In this work we will investigate the effect of ice reflective and conductive losses on the radar-detection of subsurface aquifers using an MGS MOC profile of the ice layering. We find that a basal lake located similar to 2.5 km below the surface is at the limit of detectability. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Univ Rome, INFO COM Dept, Rome, Italy. RP Farrell, WM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM william.farrell@gsfc.nasa.gov RI Farrell, William/I-4865-2013; OI Kurth, William/0000-0002-5471-6202 NR 12 TC 13 Z9 13 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 JUN 10 PY 2005 VL 32 IS 11 AR L11204 DI 10.1029/2005GL022488 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 937YO UT WOS:000229964200004 ER PT J AU Yung, YL Liang, MC Blake, GA Muller, RP Miller, CE AF Yung, YL Liang, MC Blake, GA Muller, RP Miller, CE TI Reply to comment by Rockmann and Kaiser on "Evidence for O-atom exchange in the O(D-1)+N2O reaction as the source of mass-independent isotopic fractionation in atmospheric N2O" SO GEOPHYSICAL RESEARCH LETTERS LA English DT Editorial Material ID NITROUS-OXIDE; O-17/O-16 RATIOS; O-18/O-16 C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yung, YL (reprint author), CALTECH, Div Geol & Planetary Sci, MS150-21,1200 E Calif Blvd, Pasadena, CA 91125 USA. EM mcl@gps.caltech.edu NR 11 TC 1 Z9 1 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 10 PY 2005 VL 32 IS 11 AR L11808 DI 10.1029/2005GL022669 PG 3 WC Geosciences, Multidisciplinary SC Geology GA 937YO UT WOS:000229964200008 ER PT J AU Stecker, FW AF Stecker, FW TI High energy astrophysics tests of lorentz invariance violation SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT Meeting of the Division of Particles and Fields of the American-Physical-Society CY AUG 26-31, 2004 CL Univ Calif Riverside, Riverside, CA SP Amer Phys Soc, Div Particles & Fields HO Univ Calif Riverside DE relativity; quantum gravity; cosmic rays ID QUANTUM-GRAVITY; CRAB-NEBULA; GAMMA-RAYS; SPECTRUM; TEV; MARKARIAN-501; MODELS AB Observations of the multi-TeV spectra of the Mkn 501 and other nearby BL Lac objects exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions, primarily with IR photons having a flux level as determined by various astronomical observations. After correcting for such intergalactic absorption, these spectra can be explained within the framework of synchrotron self-Compton emission models. Stecker and Glashow have shown that the existence of this annihilation via electron-positron pair production puts strong constraints on Lorentz invariance violation. Such constraints have important implications for some quantum gravity and large extra dimension models. A much smaller amount of Lorentz invariance violation has potential implications for understanding the spectra of ultrahigh energy cosmic rays. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Stecker, FW (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RI Stecker, Floyd/D-3169-2012 NR 21 TC 4 Z9 4 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X EI 1793-656X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 10 PY 2005 VL 20 IS 14 BP 3139 EP 3142 DI 10.1142/S0217751X05025966 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 952HF UT WOS:000230993900038 ER PT J AU Suresh, A AF Suresh, A TI Interaction of a shock with a density disturbance via shock fitting SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE shock capturing; shock fitting; exact solutions ID EFFICIENT IMPLEMENTATION; HYPERBOLIC EQUATIONS; SPECTRAL METHODS; EULER EQUATIONS; SCHEMES AB An accurate solution to the problem of a normal shock moving into still fluid with a density variation is presented. The solution is obtained using a shock fitted approach and Runge-Kutta time integration. Uniform third order accuracy of the scheme is demonstrated. Comparisons with shock captured solutions show that the fitted solution presented here is more accurate. © 2005 Elsevier Inc. All rights reserved. C1 NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA. RP Suresh, A (reprint author), NASA, Glenn Res Ctr, QSS Grp Inc, 21000 Brook Pk Rd,MS 142-4, Cleveland, OH 44135 USA. EM ambady.suresh@grc.nasa.gov NR 16 TC 3 Z9 3 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 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUN 10 PY 2005 VL 206 IS 1 BP 6 EP 15 DI 10.1016/j.jcp.2004.11.036 PG 10 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 926CY UT WOS:000229101600002 ER PT J AU Dowsett, HJ Chandler, MA Cronin, TM Dwyer, GS AF Dowsett, HJ Chandler, MA Cronin, TM Dwyer, GS TI Middle Pliocene sea surface temperature variability SO PALEOCEANOGRAPHY LA English DT Article ID NORTH-ATLANTIC OCEAN; JOINT INVESTIGATIONS; SOUTH-ATLANTIC; HEAT-TRANSPORT; COASTAL-PLAIN; CLIMATE; LEVEL; RECONSTRUCTIONS; CALIBRATION; CHRONOLOGY AB [1] Estimates of sea surface temperature (SST) based upon foraminifer, diatom, and ostracod assemblages from ocean cores reveal a warm phase of the Pliocene between about 3.3 and 3.0 Ma. Pollen records and plant megafossils, although not as well dated, show evidence for a warmer climate at about the same time. Increased greenhouse forcing and altered ocean heat transport are the leading candidates for the underlying cause of Pliocene global warmth. Despite being a period of global warmth, this interval encompasses considerable variability. Two new SST reconstructions are presented that are designed to provide a climatological error bar for warm peak phases of the Pliocene and to document the spatial distribution and magnitude of SST variability within the mid-Pliocene warm period. These data suggest long-term stability of low-latitude SST and document greater variability in regions of maximum warming. C1 US Geol Survey, Reston, VA USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Duke Univ, Nicholas Sch Environm & Earth Sci, Div Earth & Ocean Sci, Durham, NC 27708 USA. RP Dowsett, HJ (reprint author), US Geol Survey, 926A Natl Ctr, Reston, VA USA. EM hdowsett@usgs.gov NR 54 TC 41 Z9 42 U1 3 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD JUN 10 PY 2005 VL 20 IS 2 AR PA2014 DI 10.1029/2005PA001133 PG 9 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA 937ZG UT WOS:000229966700001 ER PT J AU Greeley, R Arvidson, R Bell, JF Christensen, P Foley, D Haldemann, A Kuzmin, RO Landis, G Neakrase, LDV Neukum, G Squyres, SW Sullivan, R Thompson, SD Whelley, PL Williams, D AF Greeley, R Arvidson, R Bell, JF Christensen, P Foley, D Haldemann, A Kuzmin, RO Landis, G Neakrase, LDV Neukum, G Squyres, SW Sullivan, R Thompson, SD Whelley, PL Williams, D TI Martian variable features: New insight from the Mars Express Orbiter and the Mars Exploration Rover Spirit SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GUSEV CRATER; DUST; THRESHOLD; SIMULATIONS AB [1] Linear, low-albedo patterns ( termed dark wind streaks) formed on the floor of Gusev crater between September 2003 and February 2004, as seen on High Resolution Stereo Camera images taken on board the Mars Express Orbiter. Pancam images from the Mars Exploration Rover Spirit show that the rover crossed a dark streak during its traverse to Bonneville crater. Spirit Microscopic Imager data reveal that sand grains within the dark wind streak are relatively free of dust, whereas grains outside the streak are mantled with dust. During the September 2004 solar conjunction, Spirit remained in one location from sol 240 to sol 260. Comparison of images taken before and after the conjunction shows that patches of soil beneath the rover darkened with respect to the adjacent soils, suggesting removal of relatively bright material. Two MI mosaics taken 18 sols apart of the surface within 0.5 m of the nearest dark patch show that some larger ( 1 - 2 mm) sand grains moved as far as 0.7 mm. These observations support the hypothesis that some dark surface patterns result from the removal and/or repositioning of fine-grained material by winds, exposing a relatively lower albedo substrate, such as coarse sand grains. Other variable features on the Gusev floor seen from orbit faded between September 2003 and February 2004 and are interpreted to represent settling of dust from the atmosphere, consistent with the accumulation of dust observed on Spirit. The observation of dark streaks fading with time, while some dark streaks were newly formed, is consistent with local wind gusts or the passage of dust devils that locally sweep dust from the surface or cause a redistribution of fine grains among larger particles. C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Russian Acad Sci, Vernadsky Inst, Moscow 117975, Russia. Glenn Res Ctr, Cleveland, OH 44135 USA. Free Univ Berlin, Dept Earth Sci, D-12249 Berlin, Germany. RP Arizona State Univ, Dept Geol Sci, Box 871404, Tempe, AZ 85287 USA. EM greeley@asu.edu; arvidson@wunder.wustl.edu; jfb8@cornell.edu; albert@shannon.jpl.nasa.gov; rok@geokhi.ru; gneukum@zedat.fu-berlin.de; squyres@astro.cornell.edu; rjs33@cornell.edu RI Whelley, Patrick/B-9560-2012 OI Whelley, Patrick/0000-0003-3266-9772 NR 23 TC 39 Z9 38 U1 0 U2 3 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 JUN 9 PY 2005 VL 110 IS E6 AR E06002 DI 10.1029/2005JE002403 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 937YY UT WOS:000229965700001 ER PT J AU Vennerstrom, S Moretto, T Rastatter, L Raeder, J AF Vennerstrom, S Moretto, T Rastatter, L Raeder, J TI Field-aligned currents during northward interplanetary magnetic field: Morphology and causes SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID POLAR-CAP CONVECTION; IMF B-Y; BIRKELAND CURRENTS; ELECTRIC-FIELDS; DAYSIDE CUSP; MODEL; MAGNETOSPHERE; IONOSPHERE; GEOSPACE; REGION AB [1] We present the results of a global MHD simulation of solar wind magnetosphere interaction during northward IMF. In particular, we emphasize the effect of the IMF By component on the reconnection geometry and the mapping along field lines to the polar ionosphere, through field-aligned currents. We find that the existence and geometry of the polar cap is closely connected to the IMF By component. During strictly northward IMF the simulated magnetosphere can remain essentially closed because the solar wind field lines reconnect in both hemispheres, thereby creating newly reconnected closed dayside field lines. The existence of a small nonzero IMF B-y component, however, effectively acts to open up the magnetosphere. When \B-y\ < B-z the position of the polar cap is strongly asymmetric with respect to the noon-midnight meridian, depending on the sign of By. In the northern hemisphere for By positive( negative) the polar cap is then located mainly in the dawnside (duskside), in close accordance with what have been observed using particle precipitation data or auroral observations. The simulated NBZ currents map to major portions of the magnetopause: the flanks and the mantle. They can exist both on open and closed field lines and are created by the shear of the newly reconnected field lines against the mantle field as they are convected tailward by the solar wind. When the IMF rotates from northward toward east, the magnetospheric mapping regions of the NBZ currents likewise rotates. However, the idea that the NBZ currents rotate to form the two sheets of FACs sandwiching the ionospheric DPY current is only partly confirmed by the simulation. C1 Danish Natl Space Ctr, DK-2100 Copenhagen, Denmark. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. RP Danish Natl Space Ctr, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark. EM sv@spacecenter.dk RI Rastaetter, Lutz/D-4715-2012; Moretto, Therese/B-6846-2013 OI Rastaetter, Lutz/0000-0002-7343-4147; Moretto, Therese/0000-0002-2403-5561 NR 40 TC 19 Z9 19 U1 2 U2 4 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 JUN 9 PY 2005 VL 110 IS A6 AR A06205 DI 10.1029/2004JA010802 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 937ZE UT WOS:000229966300001 ER PT J AU Sotin, C Jaumann, R Buratti, BJ Brown, RH Clark, RN Soderblom, LA Baines, KH Bellucci, G Bibring, JP Capaccioni, F Cerroni, P Combes, M Coradini, A Cruikshank, DP Drossart, P Formisano, V Langevin, Y Matson, DL McCord, TB Nelson, RM Nicholson, PD Sicardy, B LeMouelic, S Rodriguez, S Stephan, K Scholz, CK AF Sotin, C Jaumann, R Buratti, BJ Brown, RH Clark, RN Soderblom, LA Baines, KH Bellucci, G Bibring, JP Capaccioni, F Cerroni, P Combes, M Coradini, A Cruikshank, DP Drossart, P Formisano, V Langevin, Y Matson, DL McCord, TB Nelson, RM Nicholson, PD Sicardy, B LeMouelic, S Rodriguez, S Stephan, K Scholz, CK TI Release of volatiles from a possible cryovolcano from near-infrared imaging of Titan SO NATURE LA English DT Article ID SURFACE; OCEAN AB Titan is the only satellite in our Solar System with a dense atmosphere. The surface pressure is 1.5 bar ( ref. 1) and, similar to the Earth, N-2 is the main component of the atmosphere. Methane is the second most important component(2), but it is photodissociated on a timescale of 10(7) years ( ref. 3). This short timescale has led to the suggestion that Titan may possess a surface or subsurface reservoir of hydrocarbons(4,5) to replenish the atmosphere. Here we report near-infrared images of Titan obtained on 26 October 2004 by the Cassini spacecraft. The images show that a widespread methane ocean does not exist; subtle albedo variations instead suggest topographical variations, as would be expected for a more solid ( perhaps icy) surface. We also find a circular structure similar to 30 km in diameter that does not resemble any features seen on other icy satellites. We propose that the structure is a dome formed by upwelling icy plumes that release methane into Titan's atmosphere. C1 Univ Nantes, CNRS, UMR 6112, Lab Planetol & Geodynam, F-44100 Nantes, France. DLR, Inst Planetary Explorat, D-12489 Berlin, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Arizona, Stewart Observ, Tucson, AZ 85721 USA. US Geol Survey, Denver, CO 80225 USA. US Geol Survey, Flagstaff, AZ 86011 USA. CNR, Ist Fis Spazio Interplanetario, I-00133 Rome, Italy. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. CNR, Ist Astrofis Spaziale & Fis Cosmica, I-00133 Rome, Italy. Observ Paris, F-92195 Meudon, France. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. RP Sotin, C (reprint author), Univ Nantes, CNRS, UMR 6112, Lab Planetol & Geodynam, F-44100 Nantes, France. EM Christophe.Sotin@univ-nantes.fr RI Rodriguez, Sebastien/H-5902-2016; OI Rodriguez, Sebastien/0000-0003-1219-0641; Cerroni, Priscilla/0000-0003-0239-2741; Bellucci, Giancarlo/0000-0003-0867-8679; Capaccioni, Fabrizio/0000-0003-1631-4314 NR 11 TC 130 Z9 133 U1 1 U2 17 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUN 9 PY 2005 VL 435 IS 7043 BP 786 EP 789 DI 10.1038/nature03596 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 933NK UT WOS:000229638700043 PM 15944697 ER PT J AU Steissberg, TE Hook, SJ Schladow, SG AF Steissberg, TE Hook, SJ Schladow, SG TI Measuring surface currents in lakes with high spatial resolution thermal infrared imagery SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TAHOE; CALIFORNIA; TRANSPORT AB High spatial resolution thermal infrared satellite images acquired 38 minutes apart from Landsat ETM+ and ASTER were used to measure the surface currents and circulation in Lake Tahoe, California-Nevada, USA. Mean currents of 5 - 10 cm/s were measured, with maximum currents approaching 35 cm/s. The eastward transport of an upwelling surface jet was clearly apparent, with 15 - 30 cm/s currents. Three gyres were evident in the vector fields. The satellite image-derived surface currents and circulation patterns are consistent with surface drifter measurements acquired during a different period. These results modify the findings of an earlier study using 1.1 km AVHRR imagery, which concluded there were two counter-rotating gyres in the opposite sense to the two dominant large gyres measured in this study. The high spatial resolution and small time separation allow the surface currents and general circulation in lakes and coastal environments to be accurately quantified using the maximum cross-correlation method. C1 Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Davis, Tahoe Environm Res Ctr, Davis, CA 95616 USA. RP Steissberg, TE (reprint author), Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA. EM tsteissberg@ucdavis.edu NR 14 TC 8 Z9 8 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 JUN 8 PY 2005 VL 32 IS 11 AR L11402 DI 10.1029/2005GL022912 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 937YM UT WOS:000229963800008 ER PT J AU Ward, JG Arvidson, RE Golombek, M AF Ward, JG Arvidson, RE Golombek, M TI The size-frequency and areal distribution of rock clasts at the Spirit landing site, Gusev Crater, Mars SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ROUGHNESS ELEMENTS; WIND EROSION; THRESHOLD; SAND AB Size-frequency and nearest neighbor spacing measurements derived from the Mars Exploration Rover Spirit's Panoramic Camera images of the Gusev landing site reveal that rock clasts on the intercrater plains are smaller, better sorted, and more evenly spaced than clasts found near the crater rims. The even clast spacing is interpreted to be due to wind transport, which acts to minimize surface roughness during periods of high velocity wind. C1 Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ward, JG (reprint author), Washington Univ, Dept Earth & Planetary Sci, Campus Box 1169,1 Brookings Dr, St Louis, MO 63130 USA. EM ward@wunder.wustl.edu NR 14 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 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 8 PY 2005 VL 32 IS 11 AR L11203 DI 10.1029/2005GL022705 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 937YM UT WOS:000229963800004 ER PT J AU Mielke, SL Schwenke, DW Peterson, KA AF Mielke, SL Schwenke, DW Peterson, KA TI Benchmark calculations of the complete configuration-interaction limit of Born-Oppenheimer diagonal corrections to the saddle points of isotopomers of the H+H-2 reaction SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; CORRELATED MOLECULAR CALCULATIONS; MONTE-CARLO CALCULATIONS; SHOCK TUBE TECHNIQUE; GAUSSIAN-BASIS SETS; RATE CONSTANTS; ADIABATIC CORRECTION; WAVE-FUNCTIONS; HYDROGEN MOLECULE; TEMPERATURE-RANGE AB We present a detailed ab initio study of the effect that the Born-Oppenheimer diagonal correction (BODC) has on the saddle-point properties of the H-3 system and its isotopomers. Benchmark values are presented that are estimated to be within 0.1 cm(-1) of the complete configuration-interaction limit. We consider the basis set and correlation treatment requirements for accurate BODC calculations, and both are observed to be more favorable than for the Born-Oppenheimer energies. The BODC raises the H+H-2 barrier height by 0.1532 kcal/mol and slightly narrows the barrier-with the imaginary frequency increasing by similar to 2%. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Washington State Univ, Dept Chem, Pullman, WA 99164 USA. RP Mielke, SL (reprint author), Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. EM slmielke@chem.northwestern.edu; david.w.schwenke@nasa.gov; kipeters@wsu.edu RI Mielke, Steven/B-7533-2008; schwenke, david/I-3564-2013 OI Mielke, Steven/0000-0002-1938-7503; NR 58 TC 26 Z9 26 U1 0 U2 9 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 JUN 8 PY 2005 VL 122 IS 22 AR 224313 DI 10.1063/1.1917838 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 936LW UT WOS:000229858500032 PM 15974674 ER PT J AU O'Neill, NT Thulasiraman, S Eck, TF Reid, JS AF O'Neill, NT Thulasiraman, S Eck, TF Reid, JS TI Robust optical features of fine mode size distributions: Application to the Quebec smoke event of 2002 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SKY RADIANCE MEASUREMENTS; AEROSOLS; SUN; NETWORK; BRAZIL; DEPTH AB [ 1] Simple relationships involving the fundamental parameters of fine mode aerosol optical depth (tau(f)), Angstrom exponent (alpha(f)) and its derivative (alpha(f)') as near-monotonic functions of the effective van de Hulst parameter (rho(eff, f) = 2 (2 pi r(eff, f)/lambda) \m - 1\) were derived for the conceptual case of a log-translatable particle size distribution (LTPSD). This notion is useful in the interpretation of real sunphotometer data; the fine mode size distribution often approximates a LTPSD while departures from this behavior become more readily understood once one understands the first order optics. The near dependency of the fine mode optical parameters on rho(eff, f) was also exploited to obtain an explicit expression for rho(eff, f) as a function of alpha(f) and alpha(f)'. The relationships were applied to a representative case study to demonstrate their general applicability and then to the specific case of the July 2002 Quebec smoke event. A number of illustrations were given where the coherency of the derived relations indicated that the LTPSD concept was often a good approximation to reality. The analysis of the Quebec-smoke extinction data showed the existence of a weak but systematic dependence of the Angstrom exponents on smoke trajectory time and by inference a steady growth in particle size with time. The variation of r(eff, f) ( derived from AERONET inversions) was however observed to be inconsistent with this dependence unless one redefined this parameter in terms of the clearly delineated peak of the asymmetric fine mode particle size distribution (PSD). This definition led to a re-computed temporal rate of increase in reff, f which was coherent with the variation of the Angstrom parameters and which was coherent with a simple coagulative model based on conservation of volume. It was demonstrated that trajectory time was essentially a proxy variable for r(eff, f) and more fundamentally rho(eff, f) ( as predicted by the LTPSD relations). A similar proxy argument could be applied to the dependence of the Angstrom exponent on optical depth but such arguments are tempered by the relative variations of fine-mode abundance (A(f)) and particle size (by the value of the parameter gamma = dlogA(f)/dlogr(eff, f)). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, Monterey, CA 93943 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP O'Neill, NT (reprint author), Univ Sherbrooke, CARTEL, Sherbrooke, PQ J1K 2R1, Canada. EM norm.oneill@usherbrooke.ca RI ECK, THOMAS/D-7407-2012; Reid, Jeffrey/B-7633-2014 OI Reid, Jeffrey/0000-0002-5147-7955 NR 21 TC 15 Z9 15 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 8 PY 2005 VL 110 IS D11 AR D11207 DI 10.1029/2004JD005157 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 937YT UT WOS:000229964900001 ER PT J AU Hwang, SM Ryu, SO De Witt, KJ Rabinowitz, MJ AF Hwang, SM Ryu, SO De Witt, KJ Rabinowitz, MJ TI High temperature rate coefficient measurements of H+O-2 chain-branching and chain-terminating reaction SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CLASSICAL TRAJECTORY CALCULATIONS; RATE CONSTANTS; SHOCK-TUBE; H; PRESSURE; HYDROXYL; HYDROGEN; RANGE; O2; H2O AB Rate coefficients for H + O-2 -> OH + O (R-1) and H + O-2 + M -> HO2 + M (R-9) were measured via OH absorption behind reflected shock waves, being: k(1) = 6.73 x 10(15) T-0.50 exp(-8390 K/T) cm(3) mol(-1) s(-1) at T = 950-3100K and k(9,0)/[Ar] = 5.55 x 10(18) T-1.15 cm(6) mol(-2) s(-1) at T = 950-1200 K. Our experimental results for k(1) strongly support recent ab initio calculations showing temperature curvature due to back dissociation, HO2 -> O + OH following O + OH -> HO2 if the reaction is considered from the reverse direction. Published by Elsevier B.V. C1 NASA, Glenn Res Ctr Lewis Field, Res & Technol Directorate, Brookpark, OH 44135 USA. Univ Toledo, Dept Chem Engn, Toledo, OH 43606 USA. Yeungnam Univ, Dept Chem Engn, Dae Gu, South Korea. RP Rabinowitz, MJ (reprint author), NASA, Glenn Res Ctr Lewis Field, Res & Technol Directorate, Mail Stop 5-10, Brookpark, OH 44135 USA. EM martin.j.rabinowitz@nasa.gov NR 28 TC 22 Z9 22 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 7 PY 2005 VL 408 IS 1-3 BP 107 EP 111 DI 10.1016/j.cplett.2005.03.140 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 933TG UT WOS:000229655200020 ER PT J AU Liang, XZ Xu, M Gao, W Kunkel, K Slusser, J Dai, YJ Min, QL Houser, PR Rodell, M Schaaf, CB Gao, F AF Liang, XZ Xu, M Gao, W Kunkel, K Slusser, J Dai, YJ Min, QL Houser, PR Rodell, M Schaaf, CB Gao, F TI Development of land surface albedo parameterization based on Moderate Resolution Imaging Spectroradiometer (MODIS) data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DATA ASSIMILATION SYSTEM; FRACTIONAL VEGETATION COVER; COMMUNITY CLIMATE MODEL; LEAF-AREA INDEX; SATELLITE-OBSERVATIONS; BIOSPHERE MODEL; BIDIRECTIONAL REFLECTANCE; CANOPY REFLECTANCE; ROUGHNESS LENGTH; ENERGY-BALANCE AB [ 1] A new dynamic-statistical parameterization of snow-free land surface albedo is developed using the Moderate Resolution Imaging Spectroradiometer ( MODIS) products of broadband black-sky and white-sky reflectance and vegetation and the North American and Global Land Data Assimilation System ( LDAS) outputs of soil moisture during 2000 - 2003. The dynamic component represents the predictable albedo dependences on solar zenith angle, surface soil moisture, fractional vegetation cover, leaf plus stem area index, and greenness, while the statistical part represents the correction for static effects that are specific to local surface characteristics. All parameters of the dynamic and statistical components are determined by solving nonlinear constrained optimization problems of a physically based conceptual model for the minimization of the bulk variances between simulations and observations. They all depend on direct beam or diffuse radiation and visible or near-infrared band. The dynamic parameters are also functions of land cover category, while the statistical factors are specific to geographic location. The new parameterization realistically represents surface albedo variations, including the mean, shape, and distribution, around each dependent parameter. For composites of all temporal and spatial samples of the same land cover category over North America, correlation coefficients between the dynamic component of the new parameterization and the MODIS data range from 0.39 to 0.88, while relative errors vary within 8 - 42%. The gross (i.e., integrated over all categories) correlations and errors are 0.57 - 0.71 and 17 - 26%, changing with direct beam or diffuse radiation and visible or near-infrared band. The static local correction results in a further reduction in relative errors, producing gross values of 11 - 21%. The new parameterization is a marked improvement over the existing albedo scheme of the state-of-the-art Common Land Model ( CLM), which has correlation coefficients from - 0.57 to 0.71 and relative errors of 18 140% for individual land cover categories, and gross values of 0.03 - 0.32 and 37 - 71%, respectively. C1 Univ Illinois, Dept Nat Resources, Illinois State Water Survey, Champaign, IL 61820 USA. Colorado State Univ, Nat Resource Ecol Lab, USDA UV B Monitoring & Res Program, Ft Collins, CO 80523 USA. Beijing Normal Univ, Sch Geog, Res Ctr Remote Sensing, Beijing 100875, Peoples R China. Beijing Normal Univ, Sch Geog, GIS, Beijing 100875, Peoples R China. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12205 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. Boston Univ, Ctr Remote Sensing, Dept Geog, Boston, MA 02215 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Liang, XZ (reprint author), Univ Illinois, Dept Nat Resources, Illinois State Water Survey, 2204 Griffith Dr, Champaign, IL 61820 USA. EM xliang@uiuc.edu; minxu@uiuc.edu; wei.gao@colostate.edu; kkunkel@uiuc.edu; james.slusser@colostate.edu; yongjiudai@bnu.edu.cn; min@asrc.cestm.albany.edu; paul.houser@nasa.gov; matthew.rodell@nasa.gov; schaaf@crsa.bu.edu; fgao@ltpmail.gsfc.nasa.gov RI Houser, Paul/J-9515-2013; Dai, Yongjiu/D-1070-2010; Rodell, Matthew/E-4946-2012; Gao, Feng/F-3944-2010; Kunkel, Kenneth/C-7280-2015; Gao, Wei/C-1430-2016; Dai, Yongjiu/D-6261-2014 OI Houser, Paul/0000-0002-2991-0441; Rodell, Matthew/0000-0003-0106-7437; Kunkel, Kenneth/0000-0001-6667-7047; Dai, Yongjiu/0000-0002-3588-6644 NR 94 TC 42 Z9 45 U1 3 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 7 PY 2005 VL 110 IS D11 AR D11107 DI 10.1029/2004JD005579 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 937YS UT WOS:000229964700003 ER PT J AU Mahieu, E Zander, R Duchatelet, P Hannigan, JW Coffey, MT Mikuteit, S Hase, F Blumenstock, T Wiacek, A Strong, K Taylor, JR Mittermeier, RL Fast, H Boone, CD McLeod, SD Walker, KA Bernath, PF Rinsland, CP AF Mahieu, E Zander, R Duchatelet, P Hannigan, JW Coffey, MT Mikuteit, S Hase, F Blumenstock, T Wiacek, A Strong, K Taylor, JR Mittermeier, RL Fast, H Boone, CD McLeod, SD Walker, KA Bernath, PF Rinsland, CP TI Comparisons between ACE-FTS and ground-based measurements of stratospheric HCl and ClONO2 loadings at northern latitudes SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOS EXPERIMENT; CHLORINE; SPECTROSCOPY; SPACE AB We report first comparisons of stratospheric column abundances of hydrogen chloride (HCl) and chlorine nitrate (ClONO2) derived from infrared solar spectra recorded in 2004 at selected northern latitudes by the spaceborne Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) and by Fourier transform infrared (FTIR) instruments at the NDSC (Network for Detection of Stratospheric Change)-affiliated sites of Thule ( Greenland), Kiruna ( Sweden), Jungfraujoch ( Switzerland), and Egbert and Toronto ( Canada). Overall, and within the respective uncertainties of the independent measurement approaches, the comparisons show that the ACE-FTS measurements produce very good stratospheric volume mixing ratio profiles. Their internal precision allows to identify characteristic distribution features associated with latitudinal, dynamical, seasonal and chemical changes occurring in the atmosphere. C1 Univ Liege, Inst Astrophys & Geophys, B-4000 Cointe Ougree, Belgium. Natl Ctr Atmospher Res, Opt Tech Project, Div Atmospher Chem, Boulder, CO 80303 USA. Forschungszentrum Karlsruhe, IMK ASF, D-76021 Karlsruhe, Germany. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Meteorol Serv Canada, Downsview, ON M3H 5T4, Canada. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Univ Liege, Inst Astrophys & Geophys, 17 Allee 6 Aout,Bat 5A, B-4000 Cointe Ougree, Belgium. EM emmanuel.mahieu@ulg.ac.be; r.zander@ulg.ac.be; p.duchatelet@ulg.ac.be; jamesw@ncar.ucar.edu; coffey@ncar.ucar.edu; sabine.mikuteit@imk.fzk.de; frank.hase@imk.fzk.de; thomas.blumenstock@imk.fzk.de; aldona@atmosp.physics.utoronto.ca; strong@atmosp.physics.utoronto.ca; jeff@atmosp.physics.utoronto.ca; richard.mittermeier@ec.gc.ca; hans.fast@ec.gc.ca; cboone@acebox.uwaterloo.ca; sdmcleod@uwaterloo.ca; kwalker@acebox.uwaterloo.ca; bernath@uwaterloo.ca; c.p.rinsland@larc.nasa.gov RI Bernath, Peter/B-6567-2012; Strong, Kimberly/D-2563-2012; Blumenstock, Thomas/K-2263-2012; Hase, Frank/A-7497-2013; Barthlott, Sabine/B-1439-2013; OI Bernath, Peter/0000-0002-1255-396X; Barthlott, Sabine/0000-0003-0258-9421; Mahieu, Emmanuel/0000-0002-5251-0286 NR 12 TC 22 Z9 22 U1 0 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 JUN 4 PY 2005 VL 32 IS 15 AR L15S08 DI 10.1029/2005GL022396 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 936BU UT WOS:000229828900001 ER PT J AU Cheng, A AF Cheng, A TI Organization of mesoscale convective systems: 1. Numerical experiments SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VERTICAL WIND SHEAR; LIVED SQUALL LINES; STORMS; PRECIPITATION; OKLAHOMA; MOMENTUM; CUMULONIMBUS; SIMULATION; TRANSPORT; FLOWS AB [1] The shear-parallel and shear-perpendicular linear mesoscale convective systems (MCSs) are studied by a three-dimensional nonhydrostatic cloud resolving model. On the basis of previous observational studies, a unique "reference layer'' can be defined for both MCSs. A shear-parallel MCS can be distinguished from a shear-perpendicular MCS by the shear and moist instability in the reference layer only regardless of the shear at the other levels. This drastically simplifies the problem at hand. The reference layer is located below 400 mbar. It must be thicker than 200 mbar, and the mean shear of the layer must be larger than 2 m s(-1) per 100 mbar. Its stratification is unstable or near neutral. The shear-parallel MCS is produced when the reference layer is near neutral or less unstable. In its first phase the new cells are produced by the basic wave propagation mechanism, modified by the shear. The growth rate is relatively small, and there is no cold pool in this phase. In the second phase the updrafts become strong and expand. A cold pool is formed along the shear-parallel direction, and the new cells are formed along the edge of the cold pool. The interaction between the shear and the updraft plays a major role in the formation of the shear-parallel MCSs. The cold pool outflow convergence and the interaction between the cold pool and the shear are also important in the second phase. On the other hand, the shear-perpendicular MCS is produced when the reference layer is highly unstable. The cold pool is always strong, and the interaction between the shear and cold pool plays a major role in the formation of the linear structure in agreement with the theory proposed by Rotunno et al. ( 1988). Sensitivity experiments indicate that both types of MCS organization can exist without precipitation or a cold pool and in the dry system. This finally provides a foundation for the theoretical analysis presented in the companion paper. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Cheng, A (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. EM a.cheng@larc.nasa.gov NR 34 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 4 PY 2005 VL 110 IS D15 AR D15S11 DI 10.1029/2004JD005444 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 936CC UT WOS:000229829900001 ER PT J AU Cheng, A AF Cheng, A TI Organization of mesoscale convective systems: 2. Linear theory SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STEADY CONVECTION; SQUALL LINES; TOGA COARE; SHEAR; TRANSPORT; MOMENTUM; CUMULONIMBUS AB [ 1] The anelastic system of equations (3-D momentum, continuity and thermodynamic energy) is used to investigate the organization of mesoscale convective systems (MCSs) using the reference layer concept presented in part 1. Latent heating is assumed to be proportional to the vertical velocity. The WKBJ method is used to solve this system of equations by perturbing the solution linearly from that at the reference level, which is the top of the reference layer. The reference layer is defined as a layer with maximum wind shear and unstable moist stratification over a minimum thickness of 200 mbar. The characteristics of the reference layer, such as the magnitude of the shear and moist stratification, determine the type of MCS' organization and associated properties in the analysis. This result agrees well with numerical simulations of linear MCSs presented in part 1 of this series of study. Three types of MCSs are identified from the linear theory: one is nonlinear and two are linear. The group speed of all three types turns out to be proportional to the mean wind at the reference level. Nonlinear MCSs occur when the vertical wind shear is weak and the stratification is unstable. Type 1 linear solutions are neutral, shear-parallel lines; their reference layers are usually in the middle troposphere. Type 2 linear solutions are amplifying, shear-perpendicular lines; their reference layers are usually in the lower troposphere. The theory predicts the widths and growth rates of the type 2 linear MCSs. The width of an amplifying MCS is determined as a simple function of the Richardson number, while the growth rate is a function of vertical wind shear and Richardson number. Tests of the linear theory using data from several field experiments show that it gives fairly realistic results for a variety of the observed MCSs. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Cheng, A (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. EM a.cheng@larc.nasa.gov NR 24 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 4 PY 2005 VL 110 IS D15 AR D15S12 DI 10.1029/2004JD005450 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 936CC UT WOS:000229829900002 ER PT J AU Vinas, AF Mace, RL Benson, RF AF Vinas, AF Mace, RL Benson, RF TI Dispersion characteristics for plasma resonances of Maxwellian and Kappa distribution plasmas and their comparisons to the IMAGE/RPI observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC ELECTRON-DENSITY; VELOCITY DISTRIBUTION FUNCTIONS; BERNSTEIN MODES; STATISTICAL-MECHANICS; SOLAR-WIND; EMISSIONS; INSTABILITY; WAVES; FREQUENCIES; PARTICLES AB [1] The Radio Plasma Imager (RPI) on the IMAGE satellite stimulates short-range plasma wave echoes and plasma emissions, known as plasma resonances, which are then displayed on plasmagrams. These resonances are used to provide measurements of the local electron density ne and magnetic field strength \B\. The RPI-stimulated resonances are the magnetospheric analog of plasma resonances stimulated by topside ionospheric sounders. These resonances are stimulated at the harmonic of the electron cyclotron frequency f(ce), the electron plasma frequency f(pe), and the upper-hybrid frequency f(uh) (where f(uh)(2) = f(p)(e)2 + f(ce)(2)). They are also observed between the harmonics of f(ce) (i.e., nf(ce)) both above and below f(pe), where they are known as Qn and Dn resonances, respectively. Calculations of the Qn resonances in the ionospheric environment, based upon a thermal Maxwellian plasma model, provided confidence in the resonance identification between the observations and the estimated values within the experimental errors. However, there is often an apparent difference between these resonances in the magnetospheric environment and those predicted by calculations based on a Maxwellian plasma model. For example, the Qns are often ( and perhaps consistently) observed at frequencies slightly lower than expected for a Maxwellian plasma. We present a new set of resonance calculations using the dispersion characteristics of these resonances based upon a nonthermal kappa distribution. We then compare these calculations and those based on a traditional Maxwellian thermal plasma model with the IMAGE/RPI observations. The calculations based on the kappa distribution model appear to resolve the aforementioned frequency discrepancy. In addition, the results also provide insights into the nature of the electron distribution function in the magnetosphere. C1 NASA, Goddard Space Flight Ctr, Lab Solar & Space Phys, Greenbelt, MD 20771 USA. Univ Kwakulu Natal, Dept Phys, ZA-3201 Pietermaritzburg, South Africa. RP Vinas, AF (reprint author), NASA, Goddard Space Flight Ctr, Lab Solar & Space Phys, Greenbelt, MD 20771 USA. EM adolfo.vinas@gsfc.nasa.gov RI Mace, Richard/N-6064-2013 OI Mace, Richard/0000-0001-6062-7508 NR 45 TC 50 Z9 51 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUN 4 PY 2005 VL 110 IS A6 AR A06202 DI 10.1029/2004JA010967 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 936CN UT WOS:000229831300005 ER PT J AU Bernath, PF McElroy, CT Abrams, MC Boone, CD Butler, M Camy-Peyret, C Carleer, M Clerbaux, C Coheur, PF Colin, R DeCola, P Bernath, PF McElroy, CT Abrams, MC Boone, CD Butler, M Camy-Peyret, C Carleer, M Clerbaux, C Coheur, PF Colin, R DeCola, P DeMaziere, M Drummond, JR Dufour, D Evans, WFJ Fast, H Fussen, D Gilbert, K Jennings, DE Llewellyn, EJ Lowe, RP Mahieu, E McConnell, JC McHugh, M McLeod, SD Michaud, R Midwinter, C Nassar, R Nichitiu, F Nowlan, C Rinsland, CP Rochon, YJ Rowlands, N Semeniuk, K Simon, P Skelton, R Sloan, JJ Soucy, MA Strong, K Tremblay, P Turnbull, D Walker, KA Walkty, I Wardle, DA Wehrle, V Zander, R Zou, J AF Bernath, PF McElroy, CT Abrams, MC Boone, CD Butler, M Camy-Peyret, C Carleer, M Clerbaux, C Coheur, PF Colin, R DeCola, P Bernath, PF McElroy, CT Abrams, MC Boone, CD Butler, M Camy-Peyret, C Carleer, M Clerbaux, C Coheur, PF Colin, R DeCola, P DeMaziere, M Drummond, JR Dufour, D Evans, WFJ Fast, H Fussen, D Gilbert, K Jennings, DE Llewellyn, EJ Lowe, RP Mahieu, E McConnell, JC McHugh, M McLeod, SD Michaud, R Midwinter, C Nassar, R Nichitiu, F Nowlan, C Rinsland, CP Rochon, YJ Rowlands, N Semeniuk, K Simon, P Skelton, R Sloan, JJ Soucy, MA Strong, K Tremblay, P Turnbull, D Walker, KA Walkty, I Wardle, DA Wehrle, V Zander, R Zou, J TI Atmospheric Chemistry Experiment (ACE): Mission overview SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB SCISAT-1, also known as the Atmospheric Chemistry Experiment ( ACE), is a Canadian satellite mission for remote sensing of the Earth's atmosphere. It was launched into low Earth circular orbit ( altitude 650 km, inclination 74 degrees) on 12 Aug. 2003. The primary ACE instrument is a high spectral resolution (0.02 cm(-1)) Fourier Transform Spectrometer (FTS) operating from 2.2 to 13.3 mm ( 750 - 4400 cm(-1)). The satellite also features a dual spectrophotometer known as MAESTRO with wavelength coverage of 285 - 1030 nm and spectral resolution of 1 - 2 nm. A pair of filtered CMOS detector arrays records images of the Sun at 0.525 and 1.02 mu m. Working primarily in solar occultation, the satellite provides altitude profile information ( typically 10 - 100 km) for temperature, pressure, and the volume mixing ratios for several dozen molecules of atmospheric interest, as well as atmospheric extinction profiles over the latitudes 85 degrees N to 85 degrees S. This paper presents a mission overview and some of the first scientific results. C1 Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Environm Canada, Meteorol Serv Canada, Toronto, ON M3H 5T4, Canada. Fastmetrix Inc, Alexandria, VA USA. Univ Paris 06, Lab Phys Mol & Applicat, Paris, France. Univ Libre Bruxelles, Brussels, Belgium. Univ Paris 06, Serv Aeron, Paris, France. NASA Headquarters, Washington, DC USA. Belgian Inst Space Aeron, Brussels, Belgium. Univ Toronto, Dept Phys, Toronto, ON, Canada. Trent Univ, Dept Phys, Peterborough, ON K9J 7B8, Canada. Univ Western Ontario, Dept Phys & Astron, London, ON, Canada. NASA, Goddard Space Flight Ctr, Planetary Syst Branch, Greenbelt, MD 20771 USA. Univ Saskatchewan, Dept Phys & Engn Phys, Saskatoon, SK, Canada. Inst Astrophys & Geophys, Liege, Belgium. York Univ, Dept Earth & Space Sci & Engn, Toronto, ON M3J 2R7, Canada. GATS Inc, Newport News, VA USA. Canadian Space Agcy, St Hubert, PQ, Canada. NASA, Langley Res Ctr, Hampton, VA 23665 USA. EMS Technol, Ottawa, ON, Canada. ABB Bomem Inc, Quebec City, PQ, Canada. Univ Laval, Dept Genie Elect & Genie Informat, Quebec City, PQ, Canada. Bristol Aerosp Ltd, Winnipeg, MB, Canada. RP Univ Waterloo, Dept Chem, 200 Univ Ave W, Waterloo, ON N2L 3G1, Canada. EM bernath@uwaterloo.ca RI Jennings, Donald/D-7978-2012; Strong, Kimberly/D-2563-2012; Drummond, James/O-7467-2014; clerbaux, cathy/I-5478-2013; Bernath, Peter/B-6567-2012; OI Bernath, Peter/0000-0002-1255-396X; Mahieu, Emmanuel/0000-0002-5251-0286; Nowlan, Caroline/0000-0002-8718-9752; Nassar, Ray/0000-0001-6282-1611 NR 11 TC 417 Z9 420 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 3 PY 2005 VL 32 IS 15 AR L15S01 DI 10.1029/2005GL022386 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 936BT UT WOS:000229828800001 ER PT J AU Marshall, JR Sauke, TB Cuzzi, JN AF Marshall, JR Sauke, TB Cuzzi, JN TI Microgravity studies of aggregation in particulate clouds SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DUST AB Aggregation in clouds of submillimeter quartz and volcanic ash particles was studied in microgravity. Particle clouds generated by pulses of air immediately formed electrostatic filamentary aggregates upon cessation of air turbulence. Manual agitation of experiment chambers produced cm-size loose grain clusters which voraciously scavenged free-floating material in their vicinity. A dipole model accounts for these observations. Experimental results have ramifications for the behavior of natural cloud systems and primary accretion of solids in the early solar nebula. C1 SETI Inst, Mountain View, CA 94043 USA. NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. RP Marshall, JR (reprint author), SETI Inst, 515 N Whisman Rd, Mountain View, CA 94043 USA. EM jmarshall@seti.org NR 17 TC 12 Z9 12 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 JUN 3 PY 2005 VL 32 IS 11 AR L11202 DI 10.1029/2005GL022567 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 936BN UT WOS:000229828100001 ER PT J AU Smith, HT Shappirio, M Sittler, EC Reisenfeld, D Johnson, RE Baragiola, RA Crary, FJ McComas, DJ Young, DT AF Smith, HT Shappirio, M Sittler, EC Reisenfeld, D Johnson, RE Baragiola, RA Crary, FJ McComas, DJ Young, DT TI Discovery of nitrogen in Saturn's inner magnetosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PLASMA; SATELLITES; ENCELADUS AB We detected N+ in Saturn's magnetosphere in the range L similar to 3.5 to similar to 9.5 Saturn Radii (Rs) using data collected by the Cassini Plasma Spectrometer during Saturn Orbit Insertion and the following orbit ( Rev A). The presence of N+ in Saturn's magnetosphere has been a source of much debate since Voyager's detection of unresolved mass/charge 14 - 16 amu ions in this region. Two principal nitrogen sources have been suggested: Titan's atmosphere and nitrogen compounds trapped in Saturn's icy satellite surfaces (Sittler et al., 2004; E. C. Sittler et al., Energetic nitrogen ions within the inner magnetosphere of Saturn, submitted to Journal of Geophysical Research, 2004). The latter may contain primordial nitrogen, likely as NH3 in ice ( Stevenson, 1982; Squyers et al., 1983) or N+ that has been implanted in the surface (Delitsky and Lane, 2002). In addition to our nitrogen detection results, we also present an initial examination of possible sources of these ions. C1 Univ Virginia, Charlottesville, VA 22904 USA. SW Res Inst, San Antonio, TX 78228 USA. Univ Montana, Dept Phys & Astron, Missoula, MT 59812 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Smith, HT (reprint author), Univ Virginia, Charlottesville, VA 22904 USA. EM hts4f@virginia.edu RI Reisenfeld, Daniel/F-7614-2015; Smith, Howard/H-4662-2016 OI Smith, Howard/0000-0003-3537-3360 NR 15 TC 21 Z9 21 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 JUN 3 PY 2005 VL 32 IS 14 AR L14S03 DI 10.1029/2005GL022654 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 936BQ UT WOS:000229828400001 ER PT J AU Halthore, RN Crisp, D Schwartz, SE Anderson, GP Berk, A Bonnel, B Boucher, O Chang, FL Chou, MD Clothiaux, EE Dubuisson, P Fomin, B Fouquart, Y Freidenreich, S Gautier, C Kato, S Laszlo, I Li, Z Mather, JH Plana-Fattori, A Ramaswamy, V Ricchiazzi, P Shiren, Y Trishchenko, A Wiscombe, W AF Halthore, RN Crisp, D Schwartz, SE Anderson, GP Berk, A Bonnel, B Boucher, O Chang, FL Chou, MD Clothiaux, EE Dubuisson, P Fomin, B Fouquart, Y Freidenreich, S Gautier, C Kato, S Laszlo, I Li, Z Mather, JH Plana-Fattori, A Ramaswamy, V Ricchiazzi, P Shiren, Y Trishchenko, A Wiscombe, W TI Intercomparison of shortwave radiative transfer codes and measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MULTIPLE-SCATTERING; INHOMOGENEOUS ATMOSPHERES; CLOUD ABSORPTION; WATER-VAPOR; MODELS; SURFACE; PARAMETERIZATION; CLIMATE; APPROXIMATION; IRRADIANCE AB [1] Computation of components of shortwave ( SW) or solar irradiance in the surface-atmospheric system forms the basis of intercomparison between 16 radiative transfer models of varying spectral resolution ranging from line-by-line models to broadband and general circulation models. In order of increasing complexity the components are: direct solar irradiance at the surface, diffuse irradiance at the surface, diffuse upward flux at the surface, and diffuse upward flux at the top of the atmosphere. These components allow computation of the atmospheric absorptance. Four cases are considered from pure molecular atmospheres to atmospheres with aerosols and atmosphere with a simple uniform cloud. The molecular and aerosol cases allow comparison of aerosol forcing calculation among models. A cloud-free case with measured atmospheric and aerosol properties and measured shortwave radiation components provides an absolute basis for evaluating the models. For the aerosol-free and cloud-free dry atmospheres, models agree to within 1% ( root mean square deviation as a percentage of mean) in broadband direct solar irradiance at surface; the agreement is relatively poor at 5% for a humid atmosphere. A comparison of atmospheric absorptance, computed from components of SW radiation, shows that agreement among models is understandably much worse at 3% and 10% for dry and humid atmospheres, respectively. Inclusion of aerosols generally makes the agreement among models worse than when no aerosols are present, with some exceptions. Modeled diffuse surface irradiance is higher than measurements for all models for the same model inputs. Inclusion of an optically thick low-cloud in a tropical atmosphere, a stringent test for multiple scattering calculations, produces, in general, better agreement among models for a low solar zenith angle ( SZA = 30 degrees) than for a high SZA ( 75 degrees). All models show about a 30% increase in broadband absorptance for 30 degrees SZA relative to the clear-sky case and almost no enhancement in absorptance for a higher SZA of 75 degrees, possibly due to water vapor line saturation in the atmosphere above the cloud. C1 USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Spectral Sci Inc, Burlington, MA 01803 USA. Univ Lille 1, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Littoral Cote dOpale, ELICO, F-62930 Wimereux, France. IV Kurchatov Atom Energy Inst, Moscow 123182, Russia. Princeton Univ, Geophys Fluid Dynam Lab, NOAA, Princeton, NJ 08542 USA. Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23681 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Camp Springs, MD 20746 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Sao Paulo, Dept Ciencias Atmosfer, Inst Astron & Geofis, BR-05508900 Sao Paulo, Brazil. Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11794 USA. Natl Resources Canada, Canada Ctr Remote Sensing, Ottawa, ON K1A 0Y7, Canada. NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Halthore, RN (reprint author), USN, Res Lab, Remote Sensing Div, 4555 Overlook Ave SW, Washington, DC 20375 USA. EM halthore@nrl.navy.mil RI Boucher, Olivier/J-5810-2012; Laszlo, Istvan/F-5603-2010; Boucher, Olivier/K-7483-2012; Wiscombe, Warren/D-4665-2012; Schwartz, Stephen/C-2729-2008; Li, Zhanqing/F-4424-2010 OI Boucher, Olivier/0000-0003-2328-5769; Laszlo, Istvan/0000-0002-5747-9708; Boucher, Olivier/0000-0003-2328-5769; Wiscombe, Warren/0000-0001-6844-9849; Schwartz, Stephen/0000-0001-6288-310X; Li, Zhanqing/0000-0001-6737-382X NR 61 TC 62 Z9 64 U1 0 U2 8 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 JUN 3 PY 2005 VL 110 IS D11 AR D11206 DI 10.1029/2004JD005293 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 936BY UT WOS:000229829400001 ER PT J AU Hansen, J Nazarenko, L Ruedy, R Sato, M Willis, J Del Genio, A Koch, D Lacis, A Lo, K Menon, S Novakov, T Perlwitz, J Russell, G Schmidt, GA Tausnev, N AF Hansen, J Nazarenko, L Ruedy, R Sato, M Willis, J Del Genio, A Koch, D Lacis, A Lo, K Menon, S Novakov, T Perlwitz, J Russell, G Schmidt, GA Tausnev, N TI Earth's energy imbalance: Confirmation and implications SO SCIENCE LA English DT Article ID SEA-LEVEL RISE; CLIMATE-CHANGE; UNITED-STATES; OCEAN; TEMPERATURE; SENSITIVITY; ATMOSPHERE; SYSTEM AB Our climate model, driven mainly by increasing human-made greenhouse gases and aerosols, among other forcings, calculates that Earth is now absorbing 0.85 +/- 0.15 watts per square meter more energy from the Sun than it is emitting to space. This imbalance is confirmed by precise measurements of increasing ocean heat content over the past 10 years. Implications include(i) the expectation of additional global warming of about 0.60 degrees C without further change of atmospheric composition; (ii) the confirmation of the climate system's tag in responding to forcings, implying the need for anticipatory actions to avoid any specified level of climate change; and (iii) the likelihood of acceleration of ice sheet disintegration and sea level rise. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Columbia Earth Inst, New York, NY 10025 USA. SGT Inc, New York, NY 10025 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Columbia Univ, Dept Earth & Environm Sci, New York, NY 10025 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP NASA, Goddard Inst Space Studies, New York, NY 10025 USA. EM jhansen@giss.nasa.gov RI Perlwitz, Judith/B-7201-2008; Del Genio, Anthony/D-4663-2012; Lacis, Andrew/D-4658-2012; Schmidt, Gavin/D-4427-2012 OI Perlwitz, Judith/0000-0003-4061-2442; Del Genio, Anthony/0000-0001-7450-1359; Schmidt, Gavin/0000-0002-2258-0486 NR 36 TC 421 Z9 449 U1 9 U2 116 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 JUN 3 PY 2005 VL 308 IS 5727 BP 1431 EP 1435 DI 10.1126/science.1110252 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 933HK UT WOS:000229619300043 PM 15860591 ER PT J AU Dass, A Counsil, JA Gao, XR Leventis, N AF Dass, A Counsil, JA Gao, XR Leventis, N TI Magnetic field effects on the open circuit potential of ferromagnetic electrodes in corroding solutions SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MOLECULES; FORCE AB Magnetic fields shift the open circuit potential (OCP) of ferromagnetic electrodes (Fe, Co, and Ni) in corroding solutions. The OCP changes we observe (a) follow the series Fe > Co > Ni; (b) increase with the magnetic flux density; (c) reach a maximum with disk electrodes approximately 1 mm in diameter; and (d) depend on the orientation of the electrode. We report that when the surface of the electrode is oriented parallel (theta = 90 degrees) or perpendicular (theta = 0 degrees) to the magnetic field, the open circuit potential moves in opposite directions (positive and negative, respectively) with the largest changes occurring when the electrode surface is parallel to the magnetic field. Nonconvective sleeve electrodes produce the same behavior. The overall experimental evidence suggests that the magnetic field changes the OCP by modifying the surface concentrations of the paramagnetic participants in the corrosion process of the ferromagnetic electrode by species in solution; this in turn is accomplished by imposing a field-gradient driven mode of mass transfer upon paramagnetic species in solution (magnetophoresis). Simulations of the magnetic field around the ferromagnetic electrode at the two extreme orientations considered here show that in one case (theta = 90 degrees) field gradients actually repel, while in the other case (theta = 0 degrees) they attract paramagnetic species in the vicinity of the electrode. C1 Univ Missouri, Dept Chem, Rolla, MO 65409 USA. NASA, Glenn Res Ctr, Div Mat, Cleveland, OH 44135 USA. RP Leventis, N (reprint author), Univ Missouri, Dept Chem, Rolla, MO 65409 USA. EM Nicholas.Leventis@nasa.gov RI Dass, Amal/A-2520-2011; Dass, Amala/H-4729-2012 OI Dass, Amala/0000-0001-6942-5451 NR 30 TC 17 Z9 17 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 2 PY 2005 VL 109 IS 21 BP 11065 EP 11073 DI 10.1021/jp0442495 PG 9 WC Chemistry, Physical SC Chemistry GA 930HN UT WOS:000229406600073 PM 16852348 ER PT J AU Forsythe, EL Gorti, S Pusey, ML AF Forsythe, EL Gorti, S Pusey, ML TI Crystallization of canavalin as a function of pH SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT 10th International Conference on the Crystallization of Biological Macromolecules CY JUN 05-08, 2004 CL Beijing, PEOPLES R CHINA ID DYNAMIC LIGHT-SCATTERING; PRECRYSTALLIZATION AGGREGATION; 3-DIMENSIONAL STRUCTURE; CRYSTAL NUCLEATION; GAUSSIAN LIGHT; PROTEIN; LYSOZYME; FLUORESCENCE; RESOLUTION AB The question was posed of what happens to a protein that is known to grow as an n-mer when it is placed in solution conditions where it is monomeric. The trypsin-treated or cut form of the protein canavalin (CCAN) has been shown to nucleate and grow crystals as a trimer from neutral to slightly acidic solutions. Under these conditions the solution is composed almost wholly of trimers. The crystalline protein can be readily dissolved by weakly basic solution, which has been proposed to result in a solution that is monomeric. Results are presented for crystallization experiments of CCAN over the pH 6.4-9.6 range. CCAN was found to crystallize in the canonical rhombohedral form at all pH values. Light scattering and size-exclusion chromatography data gave no indication of monomeric CCAN. The light-scattering data also showed that trimeric CCAN slowly self-associates to form larger species. Results are presented for crystallization experiments of CCAN over the pH 6.4-9.6 range. Fluorescence anisotropy, coupled with light-scattering and gel-filtration experiments, show that the solutions are primarily trimers, with association to form larger species occurring as a function of protein concentration. These results indicate that CCAN crystal nucleation occurs by the self-association of trimers to form progressively larger species in solution, which eventually become critically sized crystal nuclei. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. BAE Syst, Huntsville, AL USA. RP Pusey, ML (reprint author), NASA, George C Marshall Space Flight Ctr, SD46, Huntsville, AL 35812 USA. EM marc.pusey@msfc.nasa.gov NR 21 TC 1 Z9 1 U1 0 U2 1 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JUN PY 2005 VL 61 BP 704 EP 709 DI 10.1107/S0907444905006761 PN 6 PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 930SI UT WOS:000229436800011 PM 15930625 ER PT J AU Judge, RA Snell, EH van der Woerd, MJ AF Judge, RA Snell, EH van der Woerd, MJ TI Extracting trends from two decades of microgravity macromolecular crystallization history SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT 10th International Conference on the Crystallization of Biological Macromolecules CY JUN 05-08, 2004 CL Beijing, PEOPLES R CHINA ID PROTEIN CRYSTAL-GROWTH; CCD VIDEO OBSERVATION; BIOLOGICAL MACROMOLECULES; REFINED STRUCTURE; DATA-BANK; SPACE; RESOLUTION; DIFFUSION; LYSOZYME; INSULIN AB Since the 1980s hundreds of macromolecular crystal growth experiments have been performed in the reduced acceleration environment of an orbiting spacecraft. Significant enhancements in structural knowledge have resulted from X-ray diffraction of the crystals grown. Similarly, many samples have shown no improvement or degradation in comparison to those grown on the ground. A complex series of interrelated factors affect these experiments and by building a comprehensive archive of the results it was aimed to identify factors that result in success and those that result in failure. Specifically, it was found that dedicated microgravity missions increase the chance of success when compared with those where crystallization took place as a parasitic aspect of the mission. It was also found that the chance of success could not be predicted based on any discernible property of the macromolecule available to us. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Snell, EH (reprint author), NASA, George C Marshall Space Flight Ctr, Code SD46, Huntsville, AL 35812 USA. EM eddie.snell@msfc.nasa.gov NR 42 TC 13 Z9 13 U1 1 U2 5 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JUN PY 2005 VL 61 BP 763 EP 771 DI 10.1107/S0907444904028902 PN 6 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 930SI UT WOS:000229436800022 PM 15930636 ER PT J AU Gorti, S Forsythe, EL Pusey, ML AF Gorti, S Forsythe, EL Pusey, ML TI Measurable characteristics of lysozyme crystal growth SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT 10th International Conference on the Crystallization of Biological Macromolecules CY JUN 05-08, 2004 CL Beijing, PEOPLES R CHINA ID ATOMIC-FORCE MICROSCOPY; EGG-WHITE LYSOZYME; TETRAGONAL LYSOZYME; MOLECULAR-PACKING; PROTEIN; RATES; KINETICS; TEMPERATURE; SOLUBILITY; MECHANISMS AB The behavior of protein crystal growth is estimated from measurements performed at both the microscopic and molecular levels. In the absence of solutal flow, it was determined that a model that balances the macromolecular flux toward the crystal surface with the flux of the crystal surface well characterizes crystal growth observed using microscopic methods. Namely, it was determined that the model provides accurate estimates for the crystal-growth velocities upon evaluation of crystal-growth measurements obtained in time. Growth velocities thus determined as a function of solution supersaturation were further interpreted using established deterministic models. From analyses of crystal-growth velocities, it was found that the mode of crystal growth varies with respect to increasing solution supersaturation, possibly owing to kinetic roughening. To verify further the hypothesis of kinetic roughening, crystal growth at the molecular level was examined using atomic force microscopy (AFM). From the AFM measurements, it was found that the magnitude of surface-height fluctuations, h(x), increases with increasing solution supersaturation. In contrast, the estimated characteristic length, xi, decreases rapidly upon increasing solution supersaturation. It was conjectured that the magnitude of both h(x) and xi could possibly determine the mode of crystal growth. Although the data precede any exact theory, the non-critical divergence of h(x) and xi with respect to increasing solution supersaturation was nevertheless preliminarily established. Moreover, approximate models to account for behavior of both h(x) and xi are also presented. C1 NASA, BAE Syst, MSFC, Phys & Biol Sci Lab, Huntsville, AL 35812 USA. RP Gorti, S (reprint author), NASA, BAE Syst, MSFC, Phys & Biol Sci Lab, Huntsville, AL 35812 USA. EM sridhar.gorti-1@nasa.gov NR 37 TC 2 Z9 2 U1 0 U2 6 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JUN PY 2005 VL 61 BP 837 EP 843 DI 10.1107/S0907444905006487 PN 6 PG 7 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 930SI UT WOS:000229436800036 PM 15930650 ER PT J AU Berrier, B AF Berrier, B TI Wanted: A vision for aeronautics SO AEROSPACE AMERICA LA English DT Letter C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Berrier, B (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0740-722X J9 AEROSPACE AM JI Aerosp. Am. PD JUN PY 2005 VL 43 IS 6 BP 5 EP 6 PG 2 WC Engineering, Aerospace SC Engineering GA 934QH UT WOS:000229722800003 ER PT J AU Smart, WD Tejada, S Maxwell, B Stroupe, A Casper, J Jacoff, A Yanco, H Bugajska, M AF Smart, WD Tejada, S Maxwell, B Stroupe, A Casper, J Jacoff, A Yanco, H Bugajska, M TI The 2004 mobile robot competition and exhibition SO AI MAGAZINE LA English DT Article AB The thirteenth AAAI Mobile Robot Competition and Exhibition was once again collocated with AAAI-2204, in San Jose, California. As in previous years, the robot events drew competitors from both academia and industry to showcase state-of-the-art mobile robot software and systems in four organized events. C1 Washington Univ, St Louis, MO 63130 USA. Univ New Orleans, Dept Comp Sci, New Orleans, LA 70148 USA. Swarthmore Coll, Swarthmore, PA 19081 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. NIST, Div Intelligent Syst, Gaithersburg, MD USA. Univ Massachusetts, Dept Comp Sci, Lowell, MA USA. RP Smart, WD (reprint author), Washington Univ, St Louis, MO 63130 USA. EM wds@cse.wustl.edu; adam.jacoff@nist.gov; holly@cs.uml.edu; magda@aic.nrl.navy.mil NR 5 TC 3 Z9 3 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELL PI MENLO PK PA 445 BURGESS DRIVE, MENLO PK, CA 94025-3496 USA SN 0738-4602 J9 AI MAG JI AI Mag. PD SUM PY 2005 VL 26 IS 2 BP 25 EP 35 PG 11 WC Computer Science, Artificial Intelligence SC Computer Science GA 936XU UT WOS:000229889700003 ER PT J AU Lian, YS Liou, MS AF Lian, YS Liou, MS TI Multiobjective optimization using coupled response surface model and evolutionary algorithm SO AIAA JOURNAL LA English DT Article ID DESIGN; ROTOR AB In this work we develop an efficient approach for computationally expensive multiobjective design optimization problems. In this approach we bring together design of experiment, a response surface model, a genetic algorithm, and computational-fluid-dynamics analysis tools to provide an integrated optimization system. We use an improved hypercube sampling to preselect an array of design points on which the computational-fluid-dynamics code will run. Then a computationally cheap surrogate model is constructed based on response surface approximation. A real-coded genetic algorithm is then applied on the surrogate model to perform multiobjective optimization. Representative solutions are chosen from the Pareto-optimal front to verify against the computational-fluid-dynamics code. This proposed method is used in the redesign of a single-stage turbopump, a two-stage turbopump, and the NASA rotor67 transonic compressor blade. For the single-stage pump optimization problem, we can improve the total head rise by 1.2% with the same power input; for the multistage pump problem, we can improve the total head rise by 0.5% at the same power input; for the rotor67 compressor blade design, we can increase the pressure ratio by 1.8% or reduce the entropy generation by 6.2%. We achieve these with a much reduced computational cost. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, John H Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Lian, YS (reprint author), Ohio Aerosp Inst, Cleveland, OH 44142 USA. EM ylian@umich.edu NR 24 TC 35 Z9 37 U1 1 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 JUN PY 2005 VL 43 IS 6 BP 1316 EP 1325 DI 10.2514/1.12994 PG 10 WC Engineering, Aerospace SC Engineering GA 930MN UT WOS:000229420200018 ER PT J AU Slutsky, BA AF Slutsky, BA TI Compensation of anetastic error in force measurement SO AIAA JOURNAL LA English DT Article ID ANELASTIC CREEP; AL-ALLOYS AB The output of a force sensor can change over time under constant load as a result of anelastic creep of components. An empirical model of this behavior in force sensors is presented. Unlike previous work, the model does not a priori assume an exponential functional form for the creep. Once parameters are obtained in a simple calibration procedure, sensor output can be quantitatively predicted, and the error that would otherwise appear in the measurement can be corrected mathematically. The proposed model captures over 98% of anelastic behavior in the bending beam load cell studied and is expected to apply to other force sensors as well, including wind-tunnel strain-gauge balances. The model also helps visualize the consequences of anelastic creep in typical. calibration and test scenarios. Results demonstrate that creep-induced error can reach or even exceed 0.3% of measured load, depending on the quality of the sensor and the load schedule. Examples are given of loading patterns susceptible to the error. C1 NASA, Ames Res Ctr, Aeromech Branch, Rotorcraft Div, Moffett Field, CA 94035 USA. RP Slutsky, BA (reprint author), NASA, Ames Res Ctr, Aeromech Branch, Rotorcraft Div, M-S N246012, Moffett Field, CA 94035 USA. EM bslutsky@mail.arc.nasa.gov NR 16 TC 1 Z9 1 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD JUN PY 2005 VL 43 IS 6 BP 1326 EP 1335 DI 10.2514/1.13016 PG 10 WC Engineering, Aerospace SC Engineering GA 930MN UT WOS:000229420200019 ER PT J AU Wenig, M Jahne, BJ Platt, U AF Wenig, M Jahne, BJ Platt, U TI Operator representation as a new differential optical absorption spectroscopy formalism SO APPLIED OPTICS LA English DT Article AB UV-visible absorption spectroscopy with extraterrestrial light sources is a widely used technique for the measurement of stratospheric and tropospheric trace gases. We focus on differential optical absorption spectroscopy (DOAS) and present an operator notation as a new formalism to describe the different processes in the atmosphere and the simplifying assumptions that compose the advantage of DOAS. This formalism provides tools to classify and reduce possible error sources of DOAS applications. (c) 2005 Optical Society of America. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Heidelberg Univ, Inst Umweltphys, D-6900 Heidelberg, Germany. Heidelberg Univ, Interdisciplinary Ctr Sci Comp, Heidelberg, Germany. RP Wenig, M (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM wenig@gsfc.nasa.gov RI Wenig, Mark/K-7279-2012 NR 12 TC 12 Z9 12 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 JUN 1 PY 2005 VL 44 IS 16 BP 3246 EP 3253 DI 10.1364/AO.44.003246 PG 8 WC Optics SC Optics GA 934QT UT WOS:000229724000013 PM 15943258 ER PT J AU Schopf, JW Kudryavtsev, AB Agresti, DG Czaja, AD Wdowiak, TJ AF Schopf, JW Kudryavtsev, AB Agresti, DG Czaja, AD Wdowiak, TJ TI Raman imagery: A new approach to assess the geochemical maturity and biogenicity of permineralized Precambrian fossils SO ASTROBIOLOGY LA English DT Review DE Raman spectroscopic imagery; Raman Index of Preservation; Precambrian fossils; kerogen maturation; biogenicity ID POLYCYCLIC AROMATIC-HYDROCARBONS; EARTHS EARLIEST FOSSILS; DUCK CREEK DOLOMITE; DISMAL LAKES GROUP; WESTERN-AUSTRALIA; CARBONACEOUS MATERIAL; MICRO-FOSSILS; ARCHEAN STROMATOLITES; METAMORPHIC ROCKS; OLDEST FOSSILS AB Laser-Raman imagery is a non-intrusive, non-destructive analytical technique, recently introduced to Precambrian paleobiology, that can be used to demonstrate a one-to-one spatial correlation between the optically discernible morphology and kerogenous composition of permineralized fossil microorganisms. Made possible by the submicron-scale resolution of the technique and its high sensitivity to the Raman signal of carbonaceous matter, such analyses can be used to determine the chemical-structural characteristics of organic-walled microfossils and associated sapropelic carbonaceous matter in acid-resistant residues and petrographic thin sections. Here we use this technique to analyze kerogenous microscopic fossils and associated carbonaceous sapropel permineralized in 22 unmetamorphosed or little-metamorphosed fine-grained chert units ranging from similar to 400 to similar to 2,100 Ma old. The lineshapes of the Raman spectra acquired vary systematically with five indices of organic geochemical maturation: (1) the mineral-based metamorphic grade of the fossil-bearing units; (2) the fidelity of preservation of the fossils studied; (3) the color of the organic matter analyzed; and both the (4) H/C and (5) N/C ratios measured in particulate kerogens isolated from bulk samples of the fossil-bearing cherts. Deconvolution of relevant spectra shows that those of relatively well-preserved permineralized kerogens analyzed in situ exhibit a distinctive set of Raman bands that are identifiable also in hydrated organic-walled microfossils and particulate carbonaceous matter freed from the cherts by acid maceration. These distinctive Raman bands, however, become indeterminate upon dehydration of such specimens. To compare quantitatively the variations observed among the spectra measured, we introduce the Raman Index of Preservation, an approximate measure of the geochemical maturity of the kerogens studied that is consistent both with the five indices of organic geochemical alteration and with spectra acquired from fossils experimentally heated under controlled laboratory conditions. The results reported provide new insight into the chemical-structural characteristics of ancient carbonaceous matter, the physicochemical changes that accompany organic geochemical maturation, and a new criterion to be added to the suite of evidence by which to evaluate the origin of minute fossil-like objects of possible but uncertain biogenicity. C1 Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Ctr Study Evolut & Origin Life, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Mol Biol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, NASA, Astrobiol Inst, Los Angeles, CA 90095 USA. Univ Alabama Birmingham, Dept Phys, Astro & Solar Syst Phys Program, Birmingham, AL USA. Univ Alabama Birmingham, Ctr Biophys Sci & Engn, Birmingham, AL USA. RP Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. EM Schopf@ess.ucla.edu NR 151 TC 79 Z9 81 U1 6 U2 34 PU MARY ANN LIEBERT, INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 EI 1557-8070 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2005 VL 5 IS 3 BP 333 EP 371 DI 10.1089/ast.2005.5.333 PG 39 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 935NM UT WOS:000229789000002 PM 15941380 ER PT J AU Kempf, MJ Chen, F Kern, R Venkateswaran, K AF Kempf, MJ Chen, F Kern, R Venkateswaran, K TI Recurrent isolation of hydrogen peroxide-resistant spores of Bacillus pumilus from a spacecraft assembly facility SO ASTROBIOLOGY LA English DT Article DE Bacillus; spores; H2O2 resistance; spacecraft assembly facility ID DNA-BINDING PROTEINS; SUBTILIS SPORES; BACTERIAL-SPORES; HEAT; ACID; INACTIVATION; MARS; ENVIRONMENTS; SPORULATION; MECHANISMS AB While the microbial diversity of a spacecraft assembly facility at the Jet Propulsion Laboratory (Pasadena, CA) was being monitored, H2O2-resistant bacterial strains were repeatedly isolated from various surface locations. H2O2 is a possible sterilant for spacecraft hardware because it is a low-temperature process and compatible with various modern-day spacecraft materials, electronics, and components. Both conventional biochemical testing and molecular analyses identified these strains as Bacillus pumilus. This Bacillus species was found in both unclassified (entrance floors, anteroom, and air-lock) and classified (floors, cabinet tops, and air) locations. Both vegetative cells and spores of several B. pumilus isolates were exposed to 5% liquid H2O2 for 60 min. Spores of each strain exhibited higher resistance than their respective vegetative cells to liquid H2O2. Results indicate that the H2O2 resistance observed in both vegetative cells and spores is strain-specific, as certain B. pumilus strains were two to three times more resistant than a standard Bacillus subtilis dosimetry strain. An example of this trend was observed when the type strain of B. pumilus, ATCC 7061, proved sensitive, whereas several environmental strains exhibited varying degrees of resistance, to H2O2. Repeated isolation of H2O2-resistant strains of B. pumilus in a clean-room is a concern because their persistence might potentially compromise life-detection missions, which have very strict cleanliness and sterility requirements for spacecraft hardware. C1 CALTECH, Jet Prop Lab, Biotechnol & Planetary Protect Grp, Pasadena, CA 91109 USA. RP Venkateswaran, K (reprint author), CALTECH, Jet Prop Lab, Biotechnol & Planetary Protect Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM kjvenkat@jpl.nasa.gov NR 54 TC 78 Z9 79 U1 0 U2 11 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 JUN PY 2005 VL 5 IS 3 BP 391 EP 405 DI 10.1089/ast.2005.5.391 PG 15 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 935NM UT WOS:000229789000004 PM 15941382 ER PT J AU Catling, DC Glein, CR Zahnle, KJ Mckay, CP AF Catling, DC Glein, CR Zahnle, KJ Mckay, CP TI Why O-2 is required by complex life on habitable planets and the concept of planetary "oxygenation time" SO ASTROBIOLOGY LA English DT Review DE oxygen; complex life; atmospheric evolution; redox; biomass spectra ID ATMOSPHERIC OXYGEN; ARCHEAN ATMOSPHERE; SIZE DISTRIBUTION; METABOLIC-RATE; GROWTH EFFICIENCIES; POPULATION-DENSITY; MOLECULAR FOSSILS; WESTERN-AUSTRALIA; SEDIMENTARY-ROCKS; SULFUR ISOTOPES AB Life is constructed from a limited toolkit: the Periodic Table. The reduction of oxygen provides the largest free energy release per electron transfer, except for the reduction of fluorine and chlorine. However, the bonding of O-2 ensures that it is sufficiently stable to accumulate in a planetary atmosphere, whereas the more weakly bonded halogen gases are far too reactive ever to achieve significant abundance. Consequently, an atmosphere rich in O-2 provides the largest feasible energy source. This universal uniqueness suggests that abundant O-2 is necessary for the high-energy demands of complex life anywhere, i.e., for actively mobile organisms of similar to 10(-1)-10(0) m size scale with specialized, differentiated anatomy comparable to advanced metazoans. On Earth, aerobic metabolism provides about an order of magnitude more energy for a given intake of food than anaerobic metabolism. As a result, anaerobes do not grow beyond the complexity of uniseriate filaments of cells because of prohibitively low growth efficiencies in a food chain. The biomass cumulative number density, n, at a particular mass, m, scales as n (> m)alpha m(-1) for aquatic aerobes, and we show that for anaerobes the predicted scaling is n alpha m(-1.5), close to a growth-limited threshold. Even with aerobic metabolism, the partial pressure of atmospheric O-2 (PO) must exceed similar to 10(3) Pa to allow organisms that rely on O-2 diffusion to evolve to a size similar to 10(-3)m P-O2 in the range similar to 10(3)-10(4) Pa is needed to exceed the threshold of similar to 10(-2) m size for complex life with circulatory physiology. In terrestrial life, O-2 also facilitates hundreds of metabolic pathways, including those that make specialized structural molecules found only in animals. The time scale to reach P-O2 similar to 10(4) Pa, or "oxygenation time," was long on the Earth (similar to 3.9 billion years), within almost a factor of 2 of the Sun's main sequence lifetime. Consequently, we argue that the oxygenation time is likely to be a key rate-limiting step in the evolution of complex life on other habitable planets. The oxygenation time could preclude complex life on Earth-like planets orbiting short-lived stars that end their main sequence lives before planetary oxygenation takes place. Conversely, Earth-like planets orbiting long-lived stars are potentially favorable habitats for complex life. C1 Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Univ Washington, Astrobiol Program, Seattle, WA 98195 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Univ Bristol, Dept Earth Sci, Wills Mem Bldg, Bristol B58 1RJ, Avon, England. EM David.Catling@bristol.ac.uk RI Catling, David/D-2082-2009; OI Catling, David/0000-0001-5646-120X NR 176 TC 86 Z9 95 U1 3 U2 32 PU MARY ANN LIEBERT, INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 EI 1557-8070 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2005 VL 5 IS 3 BP 415 EP 438 DI 10.1089/ast.2005.5.415 PG 24 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 935NM UT WOS:000229789000006 PM 15941384 ER PT J AU Morgan, ND Kochanek, CS Pevunova, O Schechter, PL AF Morgan, ND Kochanek, CS Pevunova, O Schechter, PL TI The lens redshift and galaxy environment for HE 0435-1223 SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : distances and redshifts; galaxies : individual (HE 0435-1223); galaxies : star clusters; gravitational lensing ID GRAVITATIONAL LENS; ELLIPTIC GALAXIES; INTERMEDIATE REDSHIFT; LUMINOSITY EVOLUTION; FUNDAMENTAL PLANE; QUADRUPLE QSO; DARK-MATTER; DEGENERACIES; SUBSTRUCTURE; CALIBRATION AB The redshift of the galaxy lensing HE 0435 - 1223 is 0.4546 +/- 0.0002, based on observations obtained with the Low Dispersion Survey Spectrograph 2 on the Magellan Consortium's 6.5 m Clay Telescope. Hubble Space Telescope Advanced Camera for Surveys observations of the system also reveal a spiral-rich group of 10 galaxies within 4000 of the elliptical lensing galaxy. The redshifts for two of these galaxies were measured to be in the foreground ( at z = 0.419) with respect to the lens; thus, at least some of the nearby galaxies are not part of the same physical group as the lens. Mass models of the system ( assuming same-plane deflectors) that take the local galaxy environment into account do better at explaining the observed emission-line flux ratios ( which are presumably unaffected by microlensing) than single-halo models, but the match is still not perfect. In particular, component A ( a minimum of the light travel time) is observed to be 0.20 mag brighter than predicted, and component C ( also a minimum image) is observed to be 0.16 mag fainter than predicted. The A - D time delay is predicted to be either 15.8 or 17.6 days (H-0 = 72 km s(-1) Mpc(-1)), depending on the details of the local galaxy environment. C1 Ohio State Univ, Dept Astron, Columbus, OH 43204 USA. CALTECH, Jet Prop Lab, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. RP Morgan, ND (reprint author), Ohio State Univ, Dept Astron, Columbus, OH 43204 USA. EM nmorgan@astronomy.ohio-state.edu; ckochanek@astronomy.ohio-state.edu; olga@ipac.caltech.edu; schech@space.mit.edu NR 41 TC 36 Z9 36 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 2005 VL 129 IS 6 BP 2531 EP 2541 DI 10.1086/430145 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 931FY UT WOS:000229472400002 ER PT J AU Covey, KR Greene, TP Doppmann, GW Lada, CJ AF Covey, KR Greene, TP Doppmann, GW Lada, CJ TI The angular momentum content and evolution of Class I and flat-spectrum protostars SO ASTRONOMICAL JOURNAL LA English DT Article DE accretion, accretion disks; infrared : stars; stars : formation; stars : pre-main-sequence; stars : rotation ID T-TAURI STARS; LOW-MASS STARS; MAIN-SEQUENCE STARS; ORION-NEBULA CLUSTER; NEAR-INFRARED SPECTRA; RHO-OPHIUCHI CLOUD; YOUNG STELLAR POPULATION; AURIGA MOLECULAR CLOUD; ROTATIONAL VELOCITIES; ALPHA-PERSEI AB We report on the angular momentum content of heavily embedded protostars on the basis of our analysis of the projected rotation velocities ( v sin I) of 38 Class I / flat- spectrum young stellar objects recently presented by Doppmann and others. After correcting for projection effects, we find that infrared-selected Class I/flat-spectrum objects rotate significantly more quickly ( median equatorial rotation velocity similar to 38 km s(-1)) than classical T Tauri stars (CTTSs; median equatorial rotation velocity similar to 18 km s(-1)) in the rho Ophiuchi and Taurus-Aurigae regions. Projected rotation velocity ( v sin i) is weakly correlated with T-eff in our sample but does not seem to correlate with Br gamma emission ( a common accretion tracer), the amount of excess continuum veiling (r(k)), or the slope of the spectral energy distribution between the near- and mid-IR (alpha). The detected difference in rotation speeds between Class I/flat-spectrum sources and CTTSs proves difficult to explain without some mechanism that transfers angular momentum out of the protostar between the two phases. Assuming that Class I / flat- spectrum sources possess physical characteristics ( M-*, R-*, and B-*) typical of pre-main-sequence stars, fully disk-locked Class I objects should have corotation radii within their protostellar disks that match well ( within 30%) with predicted magnetic coupling radii. The factor of 2 difference in rotation rates between Class I / flat- spectrum and CTTS sources when interpreted in the context of disk-locking models also implies a factor of 5 or greater difference in mass accretion rate between the two phases. A lower limit of. (M) over dot similar to 10(-8) M-. yr(-1) for objects transitioning from the Class I / flat- spectrum stage to CTTSs is required to account for the difference in rotation rates of the two classes by angular momentum extraction through a viscous disk via magnetic coupling. C1 Univ Washington, Dept Astron, Seattle, WA 98195 USA. NASA, Ames Res Ctr, Moffett Field, CA USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Covey, KR (reprint author), Univ Washington, Dept Astron, Box 351580, Seattle, WA 98195 USA. EM covey@astro.washington.edu; thomas.p.greene@nasa.gov; doppmann@gemini.edu; clada@cfa.harvard.edu OI Covey, Kevin/0000-0001-6914-7797 NR 84 TC 21 Z9 21 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 2005 VL 129 IS 6 BP 2765 EP 2776 DI 10.1086/429736 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 931FY UT WOS:000229472400021 ER PT J AU Cohen, M Carbon, DF Welch, WJ Lim, T Schulz, B McMurry, AD Forster, JR Goorvitch, D AF Cohen, M Carbon, DF Welch, WJ Lim, T Schulz, B McMurry, AD Forster, JR Goorvitch, D TI Far-infrared and millimeter continuum studies of K giants: alpha Bootis and alpha Tauri SO ASTRONOMICAL JOURNAL LA English DT Article DE infrared : stars; stars : atmospheres; stars : chromospheres; stars : individual (alpha Tauri, alpha Bootis) ID SPECTRAL IRRADIANCE CALIBRATION; STELLAR MODEL CHROMOSPHERES; COOL-STAR ATMOSPHERES; ISO-SWS CALIBRATION; MU-M SPECTRA; PHOTOMETRIC CALIBRATION; STANDARD STARS; WAVELENGTH SPECTROMETER; ABSOLUTE CALIBRATION; CHEMICAL-COMPOSITION AB We have imaged two normal, noncoronal, infrared-bright K giants, alpha Tau and alpha Boo, in the 1.4 and 2.8 mm continua using BIMA. These stars have been used as important absolute calibrators for several infrared satellites. Our goals are ( 1) to establish whether these stars radiate as simple photospheres or possess long-wavelength chromospheres and ( 2) to make a connection between millimeter-wave and far-infrared ( FIR) absolute flux calibrations. To accomplish these goals we also present Infrared Space Observatory Long Wavelength Spectrometer measurements of both these K giants. The FIR and millimeter continuum radiation is produced in the vicinity of the temperature minimum in alpha Tau and alpha Boo. We find that current photospheric models predict fluxes in reasonable agreement with those observed for wavelengths that sample the upper photosphere, namely, <= 125 mu m in alpha Tau and alpha Boo. We clearly detect chromospheric radiation from both stars by 2.8 mm ( 1.4 mm in the case of alpha Boo). Only additional observations can determine precisely where beyond 125 mu m the purely radiative models fail. Until then, purely radiative models for these stars can only be used with confidence for calibration purposes below 125 mu m. C1 Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Rutherford Appleton Lab, Dept Space Sci, Didcot OX11 0QX, Oxon, England. CALTECH, IPAC, Pasadena, CA 91125 USA. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Univ Calif, Hat Creek Observ, Hat Creek, CA 96040 USA. RP Cohen, M (reprint author), Univ Calif Berkeley, Radio Astron Lab, 601 Campbell Hall, Berkeley, CA 94720 USA. EM mcohen@astro.berkeley.edu; dcarbon@nas.nasa.gov; wwelch@astro.berkeley.edu; t.l.lim@rl.ac.uk; bschulz@ipac.caltech.edu; andrew.mcmurry@astro.uio.no; rforster@astro.berkeley.edu; david.goorvitch-1@nasa.gov NR 63 TC 8 Z9 8 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 2005 VL 129 IS 6 BP 2836 EP 2848 DI 10.1086/429887 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 931FY UT WOS:000229472400028 ER PT J AU Tristram, M Patanchon, G Macias-Perez, JF Ade, P Amblard, A Ansari, R Aubourg, E Benoit, A Bernard, JP Blanchard, A Bock, JJ Bouchet, FR Bourrachot, A Camus, P Cardoso, JF Couchot, F de Bernardis, P Delabrouille, J Desert, FX Douspis, M Dumoulin, L Filliatre, P Fosalba, P Giard, M Giraud-Heraud, Y Gispert, R Guglielmi, L Hamilton, JC Hanany, S Henrot-Versille, S Kaplan, J Lagache, G Lamarre, JM Lange, AE Madet, K Maffei, B Magneville, C Masi, S Mayet, F Nati, F Perdereau, O Plaszczynski, S Piat, M Ponthieu, N Prunet, S Renault, C Rosset, C Santos, D Vibert, D Yvon, D AF Tristram, M Patanchon, G Macias-Perez, JF Ade, P Amblard, A Ansari, R Aubourg, E Benoit, A Bernard, JP Blanchard, A Bock, JJ Bouchet, FR Bourrachot, A Camus, P Cardoso, JF Couchot, F de Bernardis, P Delabrouille, J Desert, FX Douspis, M Dumoulin, L Filliatre, P Fosalba, P Giard, M Giraud-Heraud, Y Gispert, R Guglielmi, L Hamilton, JC Hanany, S Henrot-Versille, S Kaplan, J Lagache, G Lamarre, JM Lange, AE Madet, K Maffei, B Magneville, C Masi, S Mayet, F Nati, F Perdereau, O Plaszczynski, S Piat, M Ponthieu, N Prunet, S Renault, C Rosset, C Santos, D Vibert, D Yvon, D TI The CMB temperature power spectrum from an improved analysis of the Archeops data SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE cosmology : cosmic microwave background; cosmology : observations; methodes : data analysis ID MICROWAVE BACKGROUND-RADIATION; PROBE WMAP OBSERVATIONS; COSMOLOGICAL CONSTRAINTS; STATISTICAL-ANALYSIS; ANISOTROPY; MAPS; INSTRUMENT; PARAMETERS; BOOMERANG; LAMBDA(0) AB We present improved results on the measurement of the angular power spectrum of the Cosmic Microwave Background (CMB) temperature anisotropies using the data from the last ARCHEOPS flight. This refined analysis is obtained by using the 6 most sensitive photometric pixels in the CMB bands centered at 143 and 217 GHz and 20% of the sky, mostly clear of foregrounds. Using two different cross-correlation methods, we obtain very similar results for the angular power spectrum. Consistency checks are performed to test the robustness of these results paying particular attention to the foreground contamination level which remains well below the statistical uncertainties. The multipole range from l = 10 to l = 700 is covered with 25 bins, confirming strong evidence for a plateau at large angular scales ( the Sachs-Wolfe plateau) followed by two acoustic peaks centered around l = 220 and l = 550 respectively. These data provide an independent confirmation, obtained at different frequencies, of the WMAP first year results. C1 Lab Phys Subatom & Cosmol, F-38026 St Martin Dheres, France. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V5Z 1M9, Canada. Cardiff Univ, Dept Phys, Cardiff CF24 3YB, Wales. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Lab Accelerateur Lineaire, F-91898 Orsay, France. CEA CE Saclay, DAPNIA, Serv Phys Particules, F-91191 Gif Sur Yvette, France. APC, F-75231 Paris, France. Ctr Rech Tres Basses Temp, F-38042 Grenoble, France. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. Lab Astrophys Tarbes Toulouse, F-31400 Toulouse, France. CALTECH, Pasadena, CA 91125 USA. Jet Prop Lab, Pasadena, CA 91109 USA. Inst Astrophys, F-75014 Paris, France. CNRS, ENST, F-75634 Paris, France. Univ Roma La Sapienza, Dipartimento Fis, Grp Cosmol Sperimentale, I-00185 Rome, Italy. Observ Grenoble, Astrophys Lab, F-38041 Grenoble, France. CSNSM, IN2P3, F-91405 Orsay, France. CEA CE Saclay, DAPNIA, Serv Astrophys, F-91191 Gif Sur Yvette, France. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. Univ Paris 06, LPHNE, F-75252 Paris, France. Univ Paris 07, LPHNE, F-75252 Paris, France. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. LERMA, Observ Paris, F-75014 Paris, France. RP Lab Phys Subatom & Cosmol, 53 Ave Martyrs, F-38026 St Martin Dheres, France. EM tristram@lpsc.in2p3.fr RI Bouchet, Francois/B-5202-2014; amblard, alexandre/L-7694-2014; Yvon, Dominique/D-2280-2015; Fosalba Vela, Pablo/I-5515-2016; Nati, Federico/I-4469-2016; OI amblard, alexandre/0000-0002-2212-5395; Nati, Federico/0000-0002-8307-5088; Masi, Silvia/0000-0001-5105-1439; de Bernardis, Paolo/0000-0001-6547-6446; Bouchet, Francois/0000-0002-8051-2924 NR 42 TC 43 Z9 43 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2005 VL 436 IS 3 BP 785 EP 797 DI 10.1051/0004-6361:20042416 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 933XX UT WOS:000229667300005 ER PT J AU Pottasch, SR Beintema, DA Feibelman, AA AF Pottasch, SR Beintema, DA Feibelman, AA TI Abundances of planetary nebulae NGC2022, NGC6818 and IC4191 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : abundances; ISM : planetary nebulae : individual : NGC2022; ISM : planetary nebulae : individual : NGC6818; ISM : planetary nebulae : individual : IC4191 ID NRAO PMN SURVEYS; EMISSION-LINES; 4.85 GHZ; ULTRAVIOLET-SPECTRA; SOURCE CATALOG; CENTRAL STARS; IC-418; FLUXES; SOLAR; MAGNITUDES AB The ISO and IUE spectra of the elliptical nebulae NGC2022, NGC6818 and IC4191 are presented. These spectra are combined with the spectra in the visual wavelength region to obtain a complete, extinction corrected, spectrum. The chemical composition of the nebulae is then calculated and compared to previous determinations. A discussion is also given of the exciting stars of the nebulae, and possible evolutionary effects. C1 Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. SRON, Lab Space Res, NL-9700 AV Groningen, Netherlands. Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Pottasch, SR (reprint author), Kapteyn Astron Inst, POB 800, NL-9700 AV Groningen, Netherlands. EM pottasch@astro.rug.nl NR 56 TC 9 Z9 9 U1 0 U2 0 PU E D P SCIENCES 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 JUN PY 2005 VL 436 IS 3 BP 953 EP 965 DI 10.1051/0004-6361:20042627 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 933XX UT WOS:000229667300020 ER PT J AU Matt, G Porquet, D Bianchi, S Falocco, S Maiolino, R Reeves, JN Zappacosta, L AF Matt, G Porquet, D Bianchi, S Falocco, S Maiolino, R Reeves, JN Zappacosta, L TI A changing inner radius in the accretion disc of Q0056-363? SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE accretion, accretion disks; galaxies : active; X-rays : galaxies; galaxies : quasars : individual : Q0056-363 ID ACTIVE GALACTIC NUCLEI; XMM-NEWTON; UNIFIED MODEL; LINE; BINARIES; GALAXY; STATE; JETS AB Q0056-363 is the most powerful X-ray quasar known to exhibit a broad, likely relativistic iron line (Porquet & Reeves 2003, A&A, 408, 119). It has been observed twice by XMM-Newton, three and half years apart ( July 2000 and December 2003). In the second observation, the UV and soft X-ray fluxes were fainter, the hard X-ray power law flatter, and the iron line equivalent width (EW) smaller than in the 2000 observation. These variations can all be explained, at least qualitatively, if the disc is truncated in the second observation. We report also on the possible detection of a transient, redshifted iron absorption line during the 2003 observation. C1 Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. ESAC, ESA, NMM Newton Sci Operat Ctr, Madrid 28080, Spain. INAF, Osserv Astrofis Arcetri, I-50125 Florence, Italy. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. RP Matt, G (reprint author), Univ Roma Tre, Dipartimento Fis, Via Vasca Navale 84, I-00146 Rome, Italy. EM matt@fis.uniroma3.it RI Bianchi, Stefano/B-4804-2010; OI Bianchi, Stefano/0000-0002-4622-4240; Porquet, Delphine/0000-0001-9731-0352 NR 25 TC 23 Z9 23 U1 0 U2 0 PU E D P SCIENCES 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 JUN PY 2005 VL 435 IS 3 BP 857 EP 861 DI 10.1051/0004-6361:2004581 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 926GU UT WOS:000229112100007 ER PT J AU Hannikainen, DC Rodriguez, J Vilhu, O Hjalmarsdotter, L Zdziarski, AA Belloni, T Poutanen, J Wu, K Shaw, SE Beckmann, V Hunstead, RW Pooley, GG Westergaard, NJ Mirabel, IF Hakala, P Castro-Tirado, A Durouchoux, P AF Hannikainen, DC Rodriguez, J Vilhu, O Hjalmarsdotter, L Zdziarski, AA Belloni, T Poutanen, J Wu, K Shaw, SE Beckmann, V Hunstead, RW Pooley, GG Westergaard, NJ Mirabel, IF Hakala, P Castro-Tirado, A Durouchoux, P TI Characterizing a new class of variability in GRS 1915+105 with simultaneous INTEGRAL/RXTE observations SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE X-rays : binaries; X-rays : stars; X-rays : individual : GRS 1915+105; gamma rays : observations; black hole physics ID BLACK-HOLE CANDIDATES; GRS 1915+105; MICROQUASAR GRS-1915+105; RELATIVISTIC EJECTIONS; RXTE OBSERVATIONS; SPECTRAL STATES; ACCRETION DISK; CYGNUS X-1; MODEL; COMPTONIZATION AB We report on the analysis of 100 ks INTEGRAL observations of the Galactic microquasar GRS 1915+105. We focus on INTEGRAL Revolution number 48 when the source was found to exhibit a new type of variability as preliminarily reported in Hannikainen ( 2003, A&A, 411, L415). The variability pattern, which we name., is characterized by a pulsing behaviour, consisting of a main pulse and a shorter, softer, and smaller amplitude precursor pulse, on a timescale of 5 min in the JEM-X 3-35 keV lightcurve. We also present simultaneous RXTE data. From a study of the individual RXTE/PCA pulse profiles we find that the rising phase is shorter and harder than the declining phase, which is opposite to what has been observed in other otherwise similar variability classes in this source. The position in the colour-colour diagram throughout the revolution corresponds to State A (Belloni et al. 2000, A&A, 355, 271) but not to any previously known variability class. We separated the INTEGRAL data into two subsets covering the maxima and minima of the pulses and fitted the resulting two broadband spectra with a hybrid thermal-non-thermal Comptonization model. The fits show the source to be in a soft state characterized by a strong disc component below similar to 6 keV and Comptonization by both thermal and non-thermal electrons at higher energies. C1 Univ Helsinki Observ, Helsinki 00014, Finland. CEA, DAPNIA, Serv Astrophys, CNRS FRE 2591, F-91191 Gif Sur Yvette, France. INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland. Nicolaus Copernicus Astron Ctr, PL-00716 Warsaw, Poland. INAF, Osserv Astron Brera, I-23807 Merate, LC, Italy. Oulu Univ, Astron Div, Oulu 90014, Finland. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. Univ Cambridge, Cavendish Lab, Astrophys Grp, Cambridge CB3 0HE, England. Danish Space Res Inst, DK-2100 Copenhagen, Denmark. European So Observ, Santiago 10, Chile. Inst Astrofis Andalucia, IAA, CSIC, Granada 18080, Spain. RP Univ Helsinki Observ, POB 14, Helsinki 00014, Finland. EM diana@astro.helsinki.fi RI Poutanen, Juri/H-6651-2016; OI Poutanen, Juri/0000-0002-0983-0049; Castro-Tirado, A. J./0000-0003-2999-3563; Rodriguez, Jerome/0000-0002-4151-4468 NR 50 TC 42 Z9 42 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 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2005 VL 435 IS 3 BP 995 EP 1004 DI 10.1051/0004-6361:20042250 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 926GU UT WOS:000229112100020 ER PT J AU Sonnabend, G Wirtz, D Vetterle, V Schieder, R AF Sonnabend, G Wirtz, D Vetterle, V Schieder, R TI High-resolution observations of Martian non-thermal CO2 emission near 10 mu m with a new tuneable heterodyne receiver SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE techniques : spectroscopic; planets and satellites : individual : Mars; infrared : solar system ID NATURAL LASER; SPECTROMETER; VENUS; MARS; SPECTROSCOPY AB We present first observations with the Tuneable Heterodyne Infrared Spectrometer (THIS). This instrument developed at University of Cologne has the potential to cover the mid-infrared from 7 to 19 μ m. By using heterodyne techniques and an acousto optical spectrometer (AOS) as a back-end the frequency resolution achieved is better than 10(7) at 10 μ m. A tuneable quantum-cascade laser (QCL) is used as a local-oscillator (LO) and the instantaneous bandwidth supplied by the mercury-cadmium-telluride (MCT) detector and the AOS is 1.4 GHz. The system operates within a factor of two of the quantum limit. During December 2003 THIS was installed at the 1.5 m McMath-Pierce solar telescope on Kitt Peak/Arizona. Observations of molecular line features from the atmosphere of Mars were carried out. We present measurements of narrow non-LTE CO2 emission from the Martian atmosphere observed with a never before achieved frequency resolution of 1 MHz. The first analysis suggests zonal winds in the mesosphere of Mars in good agreement with model predictions. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Cologne, D-50937 Cologne, Germany. RP Sonnabend, G (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM gsonnabend@lepvax.gsfc.nasa.gov; wirtz@ph1.uni-koeln.de; vetterle@ph1.uni-koeln.de; schieder@ph1.uni-koeln.de NR 20 TC 14 Z9 14 U1 1 U2 1 PU E D P SCIENCES 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 JUN PY 2005 VL 435 IS 3 BP 1181 EP 1184 DI 10.1051/0004-6361:20042393 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 926GU UT WOS:000229112100037 ER PT J AU Harrison, R Breen, A Bromage, B Davila, J AF Harrison, R Breen, A Bromage, B Davila, J TI 2007: International Heliophysical Year SO ASTRONOMY & GEOPHYSICS LA English DT Article AB In 1957 a programme of international research was organized as the International Geophysical Year (IGY) to study global phenomena of the Earth and geospace. This programme was a follow-on to the International Polar Years in 1882 - 83 and 1932 - 33. The IGY involved about 60000 scientists from 66 nations, working at thousands of stations, from pole to pole. There had never been anything like it before. The 50th anniversary of IGY will occur in 2007. Plans are well under way to organize an international programme of scientific collaboration for this time period to focus not just on the Earth but extending our horizons to the heliosphere, including the Sun, and thus including the drivers of geophysical processes, and making use of the fleet of spacecraft and numerous ground-based systems in place. This programme is called the International Heliophysical Year. C1 Rutherford Appleton Lab, Div Space Sci, Didcot OX11 0QX, Oxon, England. Univ Wales Aberystwyth, Inst Math & Phys Sci, Aberystwyth, Dyfed, Wales. Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Harrison, R (reprint author), Rutherford Appleton Lab, Div Space Sci, Didcot OX11 0QX, Oxon, England. NR 4 TC 2 Z9 2 U1 0 U2 1 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1366-8781 J9 ASTRON GEOPHYS JI Astron. Geophys. PD JUN PY 2005 VL 46 IS 3 BP 27 EP 30 PG 4 WC Astronomy & Astrophysics; Geochemistry & Geophysics SC Astronomy & Astrophysics; Geochemistry & Geophysics GA 931YA UT WOS:000229520200023 ER PT J AU Georganopoulos, M Kazanas, D Perlman, E Stecker, FW AF Georganopoulos, M Kazanas, D Perlman, E Stecker, FW TI Bulk comptonization of the cosmic microwave background by extragalactic jets as a probe of their matter content SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : general; quasars : individual (PKS 0637-752, 3C 273); radiation mechanisms : nonthermal; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; X-RAY JET; LARGE-SCALE JETS; POWERFUL RADIO GALAXIES; HUBBLE-SPACE-TELESCOPE; QUASAR GB-1508+5714; ACCRETION DISKS; HOT-SPOTS; CHANDRA; BLAZARS AB We propose a method for estimating the composition, i.e., the relative amounts of leptons and protons, of extragalactic jets that exhibit X-ray-bright knots in their kiloparsec-scale jets. The method relies on measuring, or setting upper limits on, the component of the cosmic microwave background (CMB) radiation that is bulk Comptonized (BC) by cold electrons in the relativistically flowing jet. These measurements, along with modeling of the broadband knot emission that constrains the bulk Lorentz factor Gamma of the jets, can yield estimates of the jet power carried by protons and leptons. We provide an explicit calculation of the spectrum of the BC CMB component and apply these results to PKS 0637-752 and 3C 273, two superluminal quasars with Chandra-detected large-scale jets. What makes these sources particularly suited for such a procedure is the absence of significant nonthermal jet emission in the "bridge," the region between the core and the first bright jet knot, which guarantees that most of the electrons there are cold, leaving the BC-scattered CMB radiation as the only significant source of photons in this region. At lambda = 3.6-8.0 mu m, the most likely band to observe the BC-scattered CMB emission, the Spitzer angular resolution (similar to 1 ''-3 '') is considerably smaller than the bridges of these jets (similar to 10 ''), making it possible to both measure and resolve this emission. C1 Univ Maryland, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Univ Maryland, Dept Phys, Joint Ctr Astrophys, 1000 Hilltop Circle, Baltimore, MD 21250 USA. RI Stecker, Floyd/D-3169-2012; OI Perlman, Eric/0000-0002-3099-1664 NR 53 TC 16 Z9 16 U1 0 U2 1 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 JUN 1 PY 2005 VL 625 IS 2 BP 656 EP 666 DI 10.1086/429558 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 930SJ UT WOS:000229436900008 ER PT J AU Crenshaw, DM Kraemer, SB AF Crenshaw, DM Kraemer, SB TI The connection between the narrow-line region and the UV absorbers in Seyfert galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : Seyfert; ultraviolet : galaxies ID ACTIVE GALACTIC NUCLEI; HUBBLE-SPACE-TELESCOPE; STIS ECHELLE OBSERVATIONS; INFRARED-SELECTED SAMPLE; LONG-SLIT SPECTROSCOPY; X-RAY; INTRINSIC ABSORPTION; PHYSICAL CONDITIONS; NGC 4151; EMISSION-LINE AB We present evidence that the outflowing UV absorbers in Seyfert 1 galaxies arise primarily in their inner narrow (emission-) line regions (NLRs), based on similarities in their locations, kinematics, and physical conditions. Hubble Space Telescope observations show that nearly all Seyfert galaxies have bright, central knots of [OIII] emission in their NLRs with radii of tens of parsecs. These sizes are consistent with most previous estimates of the distances of UV ( and X-ray) absorbers from their central continuum sources and a recently obtained reliable distance of similar to 25 pc for a UV absorber in the Seyfert 1 galaxy NGC 3783. The nuclear emission- line knots in a sample of 10 Seyfert galaxies have velocity widths of 300-1100 km s(-1) (half-width at zero intensity), similar to the radial velocities of most UV absorbers. The highest radial velocity for a Seyfert UV absorber to date is only -2100 km s(-1), which is much lower than typical broad-line region (BLR) velocities. There is also mounting evidence that the NLR clouds are outflowing from the nucleus, like the UV absorbers. If our hypothesis is correct, then the NLR should have a component with a high global covering factor (C-g) of the continuum source and a BLR to match that found from previous surveys of UV absorbers (C-g = 0.5-1.0). Using Space Telescope Imaging Spectrograph spectra of NGC 4151, obtained when the continuum and BLR fluxes were low, we find evidence for optically thin gas in its nuclear emission- line knot. We are able to match the line ratios from this gas with photoionization models that include a component with C-g approximate to 1 and an ionization parameter and hydrogen column density that are typical of UV absorbers. C1 Georgia State Univ, Dept Phys & Astron, Astrom Off, Atlanta, GA 30303 USA. Catholic Univ Amer, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Crenshaw, DM (reprint author), Georgia State Univ, Dept Phys & Astron, Astrom Off, 1 Pk Pl S SE,Suite 700, Atlanta, GA 30303 USA. EM crenshaw@chara.gsu.edu; stiskraemer@yancey.gsfc.nasa.gov NR 55 TC 32 Z9 32 U1 0 U2 1 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 JUN 1 PY 2005 VL 625 IS 2 BP 680 EP 687 DI 10.1086/429581 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 930SJ UT WOS:000229436900010 ER PT J AU Perlman, ES Madejski, G Georganopoulos, M Andersson, K Daugherty, T Krolik, JH Rector, T Stocke, JT Koratkar, A Wagner, S Aller, M Aller, H Allen, MG AF Perlman, ES Madejski, G Georganopoulos, M Andersson, K Daugherty, T Krolik, JH Rector, T Stocke, JT Koratkar, A Wagner, S Aller, M Aller, H Allen, MG TI Intrinsic curvature in the X-ray spectra of BL Lacertae objects SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : general; BL Lacertae objects : individual (1ES 0033+595, 1ES 0120+340, 1ES 0145+138, 1ES 0323+022, 1ES 0347-121, 1ES 0414+009, 1ES 0647+250, 1ES 1028+511, 1ES 1101-232, 1ES 1255+244, 1ES 1553+113, 1ES 1959+650, Markarian 180) galaxies : active; radiation mechanisms : nonthermal; X-rays : galaxies ID XMM-NEWTON OBSERVATIONS; ACTIVE GALACTIC NUCLEI; LOG-PARABOLIC SPECTRA; EINSTEIN SLEW SURVEY; PARTICLE-ACCELERATION; BEPPOSAX OBSERVATIONS; ABSORPTION FEATURE; TEV BLAZARS; M87 JET; VARIABILITY AB We report results from XMM-Newton observations of 13 X-ray bright BL Lacertae objects, selected from the Einstein Slew Survey sample (SSS). The survey was designed to look for evidence of departures of the X-ray spectra from a simple power-law shape (i.e., curvature and/or line features) and to find objects worthy of deeper study. Our data are generally well fit by power-law models, with three cases having hard (Gamma < 2; dN/dE proportional to E(-Gamma)) spectra that indicate synchrotron peaks at E greater than or similar to 5 keV. Previous data had suggested a presence of absorption features in the X-ray spectra of some BL Lac objects. In contrast, none of these spectra show convincing examples of line features in either absorption or emission, suggesting that such features are rare among BL Lac objects, or, more likely, are artifacts caused by instrumental effects. We find significant evidence for intrinsic curvature [steepening by d Gamma/d(log E) = 0.4 +/- 0.15] in 14 of the 17 X-ray spectra. This cannot be explained satisfactorily via excess absorption, since the curvature is essentially constant from 0.5-6 keV, an observation that is inconsistent with the modest amounts of absorption that would be required. We use the XMM-Newton Optical Monitor data with concurrent radio monitoring to derive broadband spectral energy distributions and peak frequency estimates. From these, we examine models of synchrotron emission and model the spectral curvature we see as the result of episodic particle acceleration. C1 Univ Maryland, Joint Ctr Astrophys, Dept Phys, Baltimore, MD 21250 USA. Univ Maryland, Dept Phys & Astron, Baltimore, MD 21218 USA. Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Stockholm Univ, AlbaNova Univ Ctr, CoPS, Dept Phys, S-10691 Stockholm, Sweden. Natl Radio Astron Observ, Socorro, NM 87801 USA. RP Perlman, ES (reprint author), Univ Maryland, Joint Ctr Astrophys, Dept Phys, 1000 Hilltop Circle, Baltimore, MD 21250 USA. EM perlman@jca.umbc.edu; markos@jca.umbc.edu OI Perlman, Eric/0000-0002-3099-1664 NR 61 TC 50 Z9 50 U1 0 U2 1 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 JUN 1 PY 2005 VL 625 IS 2 BP 727 EP 740 DI 10.1086/429688 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 930SJ UT WOS:000229436900014 ER PT J AU Sturner, SJ Shrader, CR AF Sturner, SJ Shrader, CR TI XTE J1550-564: Integral observations of a failed outburst SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; gamma rays : observations; radiation mechanisms : nonthermal; stars : individual ( XTE J1550-564); X-rays : binaries ID X-RAY BINARIES; BLACK-HOLE; MICROQUASAR XTE-J1550-564; STATES; COMPTONIZATION; REFLECTION; TRANSIENTS; RADIATION; EMISSION; BEHAVIOR AB The well-known black hole X-ray binary transient XTE J1550-564 underwent an outburst during the spring of 2003, which was substantially underluminous in comparison to previous periods of peak activity in that source. In addition, our analysis shows that it apparently remained in the hard spectral state over the duration of that outburst. This is again in sharp contrast to major outbursts of that source in 1998/1999, during which it exhibited an irregular light curve, multiple state changes, and collimated outflows. This leads us to classify it as a "failed outburst.'' We present the results of our study of the spring 2003 event, including light curves based on observations from both INTEGRAL and RXTE. In addition, we studied the evolution of the high-energy 3-300 keV continuum spectrum using data obtained with three main instruments on INTEGRAL. These spectra are consistent with typical low-hard-state thermal Comptonization emission. We also consider the 2003 event in the context of a multisource, multievent period-peak luminosity diagram, in which it is a clear outlier. We then consider the possibility that the 2003 event was due to a discrete accretion event rather than limit-cycle instability. In that context, we apply model fitting to derive the timescale for viscous propagation in the disk and infer some physical characteristics. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. RP Sturner, SJ (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. NR 38 TC 24 Z9 24 U1 0 U2 1 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 JUN 1 PY 2005 VL 625 IS 2 BP 923 EP 930 DI 10.1086/429815 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 930SJ UT WOS:000229436900031 ER PT J AU Ramirez-Ruiz, E Granot, J Kouveliotou, C Woosley, SE Patel, SK Mazzali, PA AF Ramirez-Ruiz, E Granot, J Kouveliotou, C Woosley, SE Patel, SK Mazzali, PA TI An off-axis model of GRB 031203 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; hydrodynamics; ISM : jets and outflows; supernovae : general ID GAMMA-RAY BURSTS; 25 APRIL 1998; UNUSUAL SUPERNOVA; LOW-LUMINOSITY; LIGHT CURVES; EMISSION; GRB-980425; ENERGY; JETS; CONSTRAINTS AB The low-luminosity radio emission of the unusually faint GRB 031203 has been argued to support the idea of a class of intrinsically subenergetic gamma-ray bursts (GRBs), currently comprising two members. While low-energy GRBs probably exist, we show that the collective prompt and multiwavelength observations of the afterglow of GRB 031203 do not necessarily require a subenergetic nature for that event. In fact, the data are more consistent with a typical, powerful GRB seen at an angle of about twice the opening angle of the central jet. The intrinsic peak energy E p of GRB 031203 then becomes similar to 2 MeV, similar to that of many other GRBs. C1 Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Inst Adv Study, Princeton, NJ 08540 USA. Stanford Univ, KIPAC, Stanford, CA 94309 USA. NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. NSSTC, USRA, Huntsville, AL USA. Osserv Astron Trieste, INAF, I-34131 Trieste, Italy. RP Ramirez-Ruiz, E (reprint author), Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. NR 36 TC 49 Z9 49 U1 0 U2 1 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 JUN 1 PY 2005 VL 625 IS 2 BP L91 EP L94 DI 10.1086/431237 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 930SK UT WOS:000229437000006 ER PT J AU Weaver, SLW Butler, RAH Drouin, BJ Petkie, DT Dyl, KA De Lucia, FC Blake, GA AF Weaver, SLW Butler, RAH Drouin, BJ Petkie, DT Dyl, KA De Lucia, FC Blake, GA TI Millimeter-wave and vibrational state assignments for the rotational spectrum of glycolaldehyde SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE ISM : molecules; methods : data analysis; methods : laboratory; molecular data; radio lines : ISM ID INTERSTELLAR GLYCOLALDEHYDE; DIPOLE-MOMENT; SUBMILLIMETER; SUGAR AB Glycolaldehyde (CHOCH2OH), the simplest two-carbon alpha-hydroxy aldehyde, has become of great interest in the field of astrochemistry due to its recent detection toward the Sagittarius B2 (N-LMH) molecular cloud. The original interstellar identification was based on an extrapolation of prior microwave rotational spectroscopy of glycolaldehyde. The millimeter and submillimeter spectra of this molecule from 128 to 354 GHz were subsequently measured after the interstellar detection. We present here the millimeter spectrum of this molecule from 72 to 122.5 GHz along with a combined millimeter and submillimeter pure rotational analysis of the ground and the first three vibrationally excited states of glycolaldehyde that enables a more complete molecular partition function to be determined. These results show that excited vibrational state contributions to the partition function are an important consideration when determining the column density of a molecule with low-lying torsional states. C1 CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 61109 USA. Wright State Univ, Dept Phys, Dayton, OH 45435 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Weaver, SLW (reprint author), CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. EM swidicus@caltech.edu NR 18 TC 22 Z9 23 U1 0 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUN PY 2005 VL 158 IS 2 BP 188 EP 192 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 930SM UT WOS:000229437300004 ER PT J AU Laming, JM Hwang, U AF Laming, JM Hwang, U TI How did Cassiopeia A explode? A Chandra VLP SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 5th International Conference on High Energy Density Laboratory Astrophysics CY MAR 10-13, 2004 CL Tucson, AZ DE supernova remnants; element abundances ID INTERSTELLAR CLOUDS; COLLAPSE; SHOCKS AB The Cassiopeia A supernova remnant will be observed by Chandra for 1 Ms this spring. We discuss our motivations and plans for acquiring and analyzing these data. C1 USN, Res Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Laming, JM (reprint author), USN, Res Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM laming@nrl.navy.mil NR 15 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0004-640X J9 ASTROPHYS SPACE SCI JI Astrophys. Space Sci. PD JUN PY 2005 VL 298 IS 1-2 BP 33 EP 37 DI 10.1007/s10509-005-3909-1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 934MK UT WOS:000229712700006 ER PT J AU Kleinbohl, A Kuttippurath, J Sinnhuber, M Sinnhuber, BM Kullmann, H Kunzi, K Notholt, J AF Kleinbohl, A Kuttippurath, J Sinnhuber, M Sinnhuber, BM Kullmann, H Kunzi, K Notholt, J TI Rapid meridional transport of tropical airmasses to the Arctic during the major stratospheric warming in January 2003 SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID LOW-OZONE POCKETS; WINTER; MODEL; ASUR AB We present observations of unusually high values of ozone and N2O in the middle stratosphere that were observed by the airborne submillimeter radiometer ASUR in the Arctic. The observations took place in the meteorological situation of a major stratospheric warming that occurred in mid-January 2003 and was dominated by a wave 2 event. On 23 January 2003 the observed N2O and O-3 mixing ratios around 69 degrees N in the middle stratosphere reached maximum values of similar to 190 ppb and similar to 10 ppm, respectively. The similarities of these N2O profiles in a potential temperature range between 800 and 1200 K with N2O observations around 20 degrees N on 1 March 2003 by the same instrument suggest that the observed Arctic airmasses were transported from the tropics quasi-isentropically. This is confirmed by 5-day back trajectory calculations which indicate that the airmasses between about 800 and 1000 K had been located around 20 degrees N 3-5 days prior to the measurement in the Arctic. Calculations with a linearized ozone chemistry model along calculated as well as idealized trajectories, initialized with the low-latitude ASUR ozone measurements, give reasonable agreement with the Arctic ozone measurement by ASUR. PV distributions suggest that these airmasses did not stay confined in the Arctic region which makes it unlikely that this dynamical situation lead to the formation of dynamically caused pockets of low ozone. C1 Univ Bremen, Inst Environm Phys, Bremen, Germany. RP Kleinbohl, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM armin.kleinboehl@jpl.nasa.gov RI Sinnhuber, Bjorn-Martin/A-7007-2013; Sinnhuber, Miriam/A-7252-2013; Notholt, Justus/P-4520-2016 OI Sinnhuber, Bjorn-Martin/0000-0001-9608-7320; Notholt, Justus/0000-0002-3324-885X NR 20 TC 10 Z9 10 U1 0 U2 0 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JUN 1 PY 2005 VL 5 BP 1291 EP 1299 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 931OA UT WOS:000229493400001 ER PT J AU Russell, P Livingston, J Schmid, B Eilers, J Kolyer, R Redemann, J Ramirez, S Yee, JH Swartz, W Shetter, R Trepte, C Risley, A Wenny, B Zawodny, J Chu, W Pitts, M Lumpe, J Fromm, M Randall, C Hoppel, K Bevilacqua, R AF Russell, P Livingston, J Schmid, B Eilers, J Kolyer, R Redemann, J Ramirez, S Yee, JH Swartz, W Shetter, R Trepte, C Risley, A Wenny, B Zawodny, J Chu, W Pitts, M Lumpe, J Fromm, M Randall, C Hoppel, K Bevilacqua, R TI Aerosol optical depth measurements by airborne sun photometer in SOLVE II: Comparisons to SAGE III, POAM III and airborne spectrometer measurements SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID COLUMNAR WATER-VAPOR; DISTRIBUTIONS; OZONE AB The 14-channel NASA Ames Airborne Tracking Sunphotometer (AATS-14) measured solar-beam transmission on the NASA DC-8 during the second SAGE III Ozone Loss and Validation Experiment (SOLVE II). This paper presents AATS-14 results for multiwavelength aerosol optical depth (AOD), including comparisons to results from two satellite sensors and another DC-8 instrument, namely the Stratospheric Aerosol and Gas Experiment III ( SAGE III), the Polar Ozone and Aerosol Measurement III (POAM III) and the Direct-beam Irradiance Airborne Spectrometer (DIAS). AATS-14 provides aerosol results at 13 wavelengths lambda spanning the range of SAGE III and POAM III aerosol wavelengths. Because most AATS measurements were made at solar zenith angles (SZA) near 90 degrees, retrieved AODs are strongly affected by uncertainties in the relative optical airmass of the aerosols and other constituents along the line of sight (LOS) between instrument and sun. To reduce dependence of the AATS-satellite comparisons on airmass, we perform the comparisons in LOS transmission and LOS optical thickness (OT) as well as in vertical OT (i.e., optical depth, OD). We also use a new airmass algorithm that validates the algorithm we previously used to within 2% for SZA<90 degrees, and in addition provides results for SZA >= 90 degrees. For 6 DC-8 flights, 19 January-2 February 2003, AATS and DIAS results for LOS aerosol OT at lambda=400 nm agree to <= 12% of the AATS value. Mean and root-mean-square (RMS) differences, (DIAS-AATS)/AATS, are -2.3% and 7.7%, respectively. For DC-8 altitudes, AATS-satellite comparisons are possible only for lambda>440 nm, because of signal depletion for shorter lambda on the satellite full-limb LOS. For the 4 AATS-SAGE and 4 AATS-POAM near-coincidences conducted 19-31 January 2003, AATS-satellite AOD differences were <= 0.0041 for all lambda>440 nm. RMS differences were <= 0.0022 for SAGE-AATS and <= 0.0026 for POAM-AATS. RMS relative differences in AOD ([SAGE-AATS]/AATS) were <= 33% for lambdasimilar to 755 nm, AATS-POAM differences were less than AATS-SAGE differences, and RMS relative differences in AOD ([AATS-POAM]/AATS) were <= 31% for all lambda between 440 and 1020 nm. Unexplained differences that remain are associated with transmission differences, rather than differences in gas subtraction or conversion from LOS to vertical quantities. The very small stratospheric AOD values that occurred during SOLVE II added to the challenge of the comparisons, but do not explain all the differences. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. SRI Int, Menlo Pk, CA 94025 USA. Bay Area Environm Res Inst, Sonoma, CA 95476 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Langley Res Ctr, SAIC, Hampton, VA 23681 USA. Computat Phys Inc, Springfield, VA 22151 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. RP Russell, P (reprint author), NASA, Ames Res Ctr, MS 245-5, Moffett Field, CA 94035 USA. EM philip.b.russell@nasa.gov RI Fromm, Michael/F-4639-2010; Swartz, William/A-1965-2010; Randall, Cora/L-8760-2014 OI Swartz, William/0000-0002-9172-7189; Randall, Cora/0000-0002-4313-4397 NR 27 TC 22 Z9 22 U1 0 U2 0 PU COPERNICUS GESELLSCHAFT MBH PI GOTTINGEN PA BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY SN 1680-7316 EI 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JUN 1 PY 2005 VL 5 BP 1311 EP 1339 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 931OA UT WOS:000229493400003 ER PT J AU Miller, TM Ballenthin, JO Viggiano, AA Anderson, BE Wey, CC AF Miller, TM Ballenthin, JO Viggiano, AA Anderson, BE Wey, CC TI Mass distribution and concentrations of negative chemiions in the exhaust of a jet engine: Sulfuric acid concentrations and observation of particle growth SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE jet engine; ion-induced nucleation; aerosol growth; sulfuric acid; mass spectrometer ID AIRCRAFT IN-FLIGHT; GAS-PHASE REACTION; ION-ION RECOMBINATION; AEROSOL FORMATION; LOWER STRATOSPHERE; VAPOR; H2SO4; PLUME; WAKE; TROPOSPHERE AB Measurements of negative-ion composition and density have been made in the exhaust of a J85-GE-5H turbojet, at ground level, as part of the NASA-EXCAVATE campaign. The mass spectrometer was placed 3 m from the exhaust plane of the engine. Measurements were done as a function of engine power in six steps from idle (50%) to military power (100%). Since the exhaust velocity changes with power, this also corresponds to a time evolution for ion growth. At 100% power most of the ions are HSO4- with minor amounts of HSO4-(H2O)(n). With decreasing engine power the degree of hydration increases. In addition, ions with a 139-amu core dominate the spectra at lower engine power. The chemical identity of this ion is unknown. Observation of a small amount of NO3- core ions in the high-power spectra allows the determination of H2SO4 concentrations, which turn out to be a fraction-of-a-percent of the total sulfur in the fuel. Combining the present data with several previous composition measurements allows one to observe ion evolution from bare ions to ions with masses > 8000 amu. Ion densities are derived and appear consistent with previous measurements used in modeling studies indicating that ion nucleation is a probable mechanism for volatile aerosol formation. Published by Elsevier Ltd. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom Air Force Base, Hanscom AFB, MA 01731 USA. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. NASA, Engine Components Div, Army Res Lab, High Speed Syst Off,Glenn Res Ctr, Cleveland, OH 44135 USA. RP Viggiano, AA (reprint author), USAF, Res Lab, Space Vehicles Directorate, Hanscom Air Force Base, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. EM albert.viggiano@hanscom.af.mil NR 52 TC 8 Z9 8 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 EI 1873-2844 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUN PY 2005 VL 39 IS 17 BP 3069 EP 3079 DI 10.1016/j.atmosenv.2005.01.034 PG 11 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 940DM UT WOS:000230123900007 ER PT J AU Vautard, R Bessagnet, B Chin, M Menut, L AF Vautard, R Bessagnet, B Chin, M Menut, L TI On the contribution of natural Aeolian sources to particulate matter concentrations in Europe: Testing hypotheses with a modelling approach SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE Aeolian dust emission; resuspension; soil erosion; Saharan dust; CHIMERE model ID ATMOSPHERIC AEROSOLS; FRICTION VELOCITY; BACKGROUND SITES; UNITED-STATES; MINERAL DUST; GOCART MODEL; WIND EROSION; SIMULATION; THRESHOLD; TRANSPORT AB The significance of natural sources in the concentrations of particles smaller than 10 mu m (PM10) in Europe is addressed. When considering only European anthropogenic emissions, chemistry-transport model simulations underestimate the PM10 concentrations by 30-50%, using the current knowledge about aerosol physics and chemistry. Along this article we hypothesize that the missing mass originates from natural sources like erosion dust entrainment and resuspension. The methodology consists in testing these hypotheses in the CHIMERE regional chemistry-transport model, and comparing the results with long series of PM10 measurements in Europe. It is demonstrated that the introduction of background Saharan dust boundary conditions greatly improves the model simulation over Southern Europe, and to a smaller extent also over northern Europe. However to accurately simulate acute episodes of Saharan dust transport time-resolved boundary conditions need to be used. Local erosion occurring over European regions is also considered. The introduction of a simplified bulk scheme for online calculation of mineral dust emission makes the model skill improve everywhere in Europe, indicating that this process can be significant in Europe. We finally assume that resuspension of material available on the ground, explains most of the remaining part of the missing part of PM10 average load. A simplified scheme for the corresponding emission, which depends on turbulence near the ground, is proposed. It also makes the model improve substantially, especially over Northern Europe. However sensitivity tests show that such an improvement can also be obtained by simply increasing the model secondary organic matter in aerosols by a factor of 3. We conclude that our results are consistent with the existence of a strong biogenic resuspension aerosol source, but more experimental work is required to ascertain this hypothesis. (c) 2005 Elsevier Ltd. All rights reserved. C1 Ecole Polytech, Inst Pierre Simon Lapl, Lab Meteorol, F-91128 Palaiseau, France. Inst Natl Environm Ind & Risques, INERIS, Verneuil En Halatte, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lab Interuniv Syst Atmospher, Creteil, France. RP Ecole Polytech, Inst Pierre Simon Lapl, Lab Meteorol, F-91128 Palaiseau, France. EM vautard@lmd.polytechnique.fr RI Chin, Mian/J-8354-2012; Menut, Laurent/O-2296-2016; Bessagnet, Bertrand/O-2969-2016 OI Menut, Laurent/0000-0001-9776-0812; Bessagnet, Bertrand/0000-0003-2062-4681 NR 45 TC 106 Z9 106 U1 3 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 EI 1873-2844 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUN PY 2005 VL 39 IS 18 BP 3291 EP 3303 DI 10.1016/j.atmosenv.2005.01.051 PG 13 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 940DX UT WOS:000230125000010 ER PT J AU Foale, CM Kaleri, AY Sargsyan, AE Hamilton, DR Melton, S Martin, D Dulchavsky, SA AF Foale, CM Kaleri, AY Sargsyan, AE Hamilton, DR Melton, S Martin, D Dulchavsky, SA TI Diagnostic instrumentation aboard ISS: Just-in-time training for non-physician crewmembers SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE ultrasound; aerospace; NASA; medical education; equipment design; radiology; surgery; medical technology ID INTERNATIONAL-SPACE-STATION; FOCUSED ASSESSMENT; TRAUMA FAST; SONOGRAPHY; MEDICINE AB Introduction: The performance of complex tasks on the International Space Station (ISS) requires significant preflight crew training commitments and frequent skill and knowledge refreshment. This report documents a recently developed "just-in-time" training methodology, which integrates preflight hardware familiarization and procedure training with an on-orbit CD-ROM-based skill enhancement. This "just-in-time" concept was used to support real-time remote expert guidance to complete ultrasound examinations using the ISS Human Research Facility (HRF). Methods: An American and Russian ISS crewmember received 2 h of "hands on" ultrasound training 8 mo prior to the on-orbit ultrasound exam. A CD-ROM-based Onboard Proficiency Enhancement (OPE) interactive multimedia program consisting of memory enhancing tutorials, and skill testing exercises, was completed by the crewmember 6 d prior to the on-orbit ultrasound exam. The crewmember was then remotely guided through a thoracic, vascular, and echocardiographic examination by ultrasound imaging experts. Results: Results of the CD-ROM-based OPE session were used to modify the instructions during a complete 35-min real-time thoracic, cardiac, and carotid/jugular ultrasound study. Following commands from the ground-based expert, the crewmember acquired all target views and images without difficulty. The anatomical content and fidelity of ultrasound video were adequate for clinical decision making. Conclusions: Complex ultrasound experiments with expert guidance were performed with high accuracy following limited preflight training and multimedia based in-flight review, despite a 2-s communication latency. In-flight application of multimedia proficiency enhancement software, coupled with real-time remote expert guidance, facilitates the successful performance of ultrasound examinations on orbit and may have additional terrestrial and space applications. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Wyle Labs, Houston, TX USA. Henry Ford Hosp, Dept Surg, Detroit, MI 48202 USA. RP Hamilton, DR (reprint author), Wyle Life Sci, Elec Engn Clin Syst Dev, 1290 Hercules Dr,Ste 120, Houston, TX 77058 USA. EM dhamilton@wylehou.com NR 13 TC 29 Z9 30 U1 4 U2 7 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 BP 594 EP 598 PG 5 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 932MO UT WOS:000229558000014 PM 15945407 ER PT J AU Carter, JA Buckey, JC Greenhalgh, L Holland, AW Hegel, MT AF Carter, JA Buckey, JC Greenhalgh, L Holland, AW Hegel, MT TI An interactive media program for managing psychosocial problems on long-duration spaceflights SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT Workshop on New Directions in Spaceflight Behavioral Health CY DEC 02-03, 2003 CL Davis, CA DE spaceflight; multimedia; interactive; psychological; psychosocial; psychiatric; training; intervention; assessment ID RANDOMIZED CONTROLLED-TRIAL; PROBLEM-SOLVING TREATMENT; SELF-ADMINISTERED TREATMENTS; PRIMARY-CARE; MINOR DEPRESSION; MAJOR DEPRESSION; OLDER-ADULTS; COMPUTER; THERAPY; MULTIMEDIA AB Space crews must be self-reliant to complete long-duration missions successfully. This project involves the development and evaluation of a network of self-guided interactive multimedia programs to train and assist long-duration flyers in the prevention, assessment, and management of psychosocial problems that can arise on extended missions. The system is currently under development and is intended for use both during training and on orbit. A virtual space station 3-dimensional graphic was created to serve as a portal to multimedia-based training, assessment, and intervention resources. Additionally, original content on interpersonal conflict and depression is being developed for the system. input on the best practices for managing conflict and depression on extended missions was obtained from 13 veteran long-duration flyers, as well as from clinical experts. Formative evaluation of a prototype of the system will be conducted with 10 members of the astronaut corps. Subsequently, the content on conflict and depression will be completed, and the depression self-treatment portion will be evaluated in a randomized controlled trial. Although this study involves developing countermeasures to assist long-duration flyers, it also provides a model that could be applied in many Earthbound settings, both in operational environments and in everyday life. C1 Harvard Univ, Sch Med, Beth Israel Deaconess Med Ctr, Boston, MA 02215 USA. Dartmouth Coll Sch Med, Hanover, NH USA. Dartmouth Coll, Amos Tuck Sch Business Adm, Hanover, NH 03755 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Carter, JA (reprint author), Harvard Univ, Sch Med, Beth Israel Deaconess Med Ctr, 330 Brookline Ave,Feldberg 867, Boston, MA 02215 USA. EM jacarter@caregroup.harvard.edu NR 89 TC 15 Z9 15 U1 2 U2 7 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B213 EP B223 PG 11 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600028 PM 15943215 ER PT J AU Flynn, CF AF Flynn, CF TI An operational approach to long-duration mission behavioral health and performance factors SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT Workshop on New Directions in Spaceflight Behavioral Health CY DEC 02-03, 2003 CL Davis, CA DE extreme environments; space medicine; aerospace psychiatry ID TRAFFIC-CONTROLLER SHIFTWORK; CIRCADIAN-RHYTHMS; PSYCHIATRIC-DISORDERS; AVIATION ENVIRONMENT; PROLONGED ISOLATION; SPACE MISSIONS; IN-SPACE; MILITARY; SLEEP; SPACEFLIGHT AB NASA's participation in nearly 10 yr of long-duration mission (LDM) training and flight confirms that these missions remain a difficult challenge for astronauts and their medical care providers. The role of the astronaut's crew surgeon is to maximize the astronaut's health throughout all phases of the LDM: preflight, in flight, and postflight. in support of the crew surgeon, the NASA-Johnson Space Center Behavioral Health and Performance Group (JSC-BHPG) has focused on four key factors that can reduce the astronaut's behavioral health and performance. These factors are defined as: sleep and circadian factors; behavioral health factors; psychological adaptation factors; and human-to-system interface (the interface between the astronaut and the mission workplace) factors. Both the crew surgeon and the JSC-BHPG must earn the crewmember's trust preflight to encourage problem identification and problem solving in these four areas. Once on orbit, the crew medical officer becomes a valuable extension of the crew surgeon and BHPG on the ground due to the crew medical officer's constant interaction with crewmembers and preflight training in these four factors. However, the crew surgeon, BHPG, and the crew medical officer need tools that will help predict, prevent, monitor, and respond to developing problems. Objective data become essential when difficult mission termination decisions must be made. The need for behavioral health and performance tool development creates an environment rich for collaboration between operational healthcare providers and researchers. These tools are also a necessary step to safely complete future, more autonomous exploration-class space missions. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Flynn, CF (reprint author), 2401 E St NW,L-223, Washington, DC 20522 USA. EM flynncf@state.gov NR 78 TC 7 Z9 7 U1 1 U2 6 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B42 EP B51 PG 10 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600007 PM 15943194 ER PT J AU Kane, RL Short, P Sipes, W Flynn, CF AF Kane, RL Short, P Sipes, W Flynn, CF TI Development and validation of the spaceflight cognitive assessment tool for windows (WinSCAT) SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT Workshop on New Directions in Spaceflight Behavioral Health CY DEC 02-03, 2003 CL Davis, CA DE spaceflight; behavioral health; cognitive assessment; psychometrics ID INDUCED ALLERGIC RHINITIS; BRAIN INJURY; NEUROPSYCHOLOGICAL ASSESSMENT; MENTAL PERFORMANCE; DIPHENHYDRAMINE; CONCUSSION; VIGILANCE; TESTS AB The Spaceflight Cognitive Assessment Tool for Windows (WinSCAT) was developed by an integrated product team as a tool to support medical operations at NASA Johnson Space Center and as way to monitor the neurocognitive status of space crews. It is based on 20 yr of experience in performance and cognitive testing within the U.S. Department of Defense. As a result, WinSCAT development has benefited from diverse efforts supporting its technical reliability and validation. The rationale, background, and development of WinSCAT are described, research supporting its use is summarized, and recommendations are made for its continued development. C1 Univ Maryland, Sch Med, VA Med Ctr, Baltimore, MD 21201 USA. Baltimore Educ & Res Fdn, Baltimore, MD USA. Wyle Labs, Houston, TX USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Kane, RL (reprint author), Univ Maryland, Sch Med, VA Med Ctr, 10 N Greene St, Baltimore, MD 21201 USA. EM robert.kane@med.va.gov NR 34 TC 20 Z9 22 U1 1 U2 3 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B183 EP B191 PG 9 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600024 PM 15943211 ER PT J AU Lugg, DJ AF Lugg, DJ TI Behavioral health in Antarctica: Implications for long-duration space missions SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT Workshop on New Directions in Spaceflight Behavioral Health CY DEC 02-03, 2003 CL Davis, CA DE behavioral health; Antarctica; extreme environments; isolation; analogue; space ID PSYCHOLOGY AB Ideally, evidence from long-duration spaceflight should be used to predict likely occurrences of behavioral health events and for planning management strategies for such events. With small numbers of space travelers, and limited long-duration missions of a year or more, Earth analogues and simulations must be used as the evidence base, despite such analogues lacking microgravity, radiation, rapidly altering photoperiodicity, and fidelity to space. Antarctic health data are reviewed and an assessment made of the likely frequency of behavioral health events. Based on the Antarctic evidence, the likelihood of behavioral health problems in space is low. However, such cases may be serious and of high consequence, placing considerable demands on the mission crew and ground support to achieve a successful outcome, given the availability of pharmaceuticals and resources. C1 NASA HQ, Off Chief Hlth & Med Officer, Washington, DC 20546 USA. RP Lugg, DJ (reprint author), NASA HQ, Off Chief Hlth & Med Officer, 300 E St SW, Washington, DC 20546 USA. EM desmond.j.lugg@nasa.gov NR 31 TC 16 Z9 20 U1 1 U2 5 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B74 EP B77 PG 4 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600011 PM 15943198 ER PT J AU Mallis, MM DeRoshia, CW AF Mallis, MM DeRoshia, CW TI Circadian rhythms, sleep, and performance in space SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT Workshop on New Directions in Spaceflight Behavioral Health CY DEC 02-03, 2003 CL Davis, CA DE circadian rhythms; sleep; alertness; fatigue; performance; human space operations ID PSYCHOMOTOR PERFORMANCE; VIGILANCE PERFORMANCE; BIOLOGICAL RHYTHMS; MENTAL PERFORMANCE; MELATONIN RHYTHM; SHUTTLE MISSIONS; DOSE-RESPONSE; TIME-COURSE; SPACEFLIGHT; ALERTNESS AB Maintaining optimal alertness and neurobehavioral functioning during space operations is critical to enable the National Aeronautics and Space Administration's (NASA's) vision "to extend humanity's reach to the Moon, Mars and beyond" to become a reality. Field data have demonstrated that sleep times and performance of crewmembers can be compromised by extended duty days, irregular work schedules, high workload, and varying environmental factors. This paper documents evidence of significant sleep loss and disruption of circadian rhythms in astronauts and associated performance decrements during several space missions, which demonstrates the need to develop effective countermeasures. Both sleep and circadian disruptions have been identified in the Behavioral Health and Performance (BH&P) area and the Advanced Human Support Technology (AHST) area of NASA's Bioastronautics Critical Path Roadmap. Such disruptions could have serious consequences on the effectiveness, health, and safety of astronaut crews, thus reducing the safety margin and increasing the chances of an accident or incident. These decrements oftentimes can be difficult to detect and counter effectively in restrictive operational environments. NASA is focusing research on the development of optimal sleep/wake schedules and countermeasure timing and application to help mitigate the cumulative effects of sleep and circadian disruption and enhance operational performance. investing research in humans is one of NASA's building blocks that will allow for both short- and long-duration space missions and help NASA in developing approaches to manage and overcome the human limitations of space travel. In addition to reviewing the current state of knowledge concerning sleep and circadian disruptions during space operations, this paper provides an overview of NASA's broad research goals. Also, NASA-funded research, designed to evaluate the relationships between sleep quality, circadian rhythm stability, and performance proficiency in both ground-based simulations and space mission studies, as described in the 2003 NASA Task Book, will be reviewed. C1 NASA, Ames Res Ctr, Fatigue Countermeasures Grp, Moffett Field, CA USA. RP Mallis, MM (reprint author), Alertness Solut, 20111 Stevens Creek Blvd,Ste 280, Cupertino, CA 95014 USA. EM mmallis@alertsol.com NR 155 TC 43 Z9 54 U1 6 U2 23 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B94 EP B107 PG 14 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600015 PM 15943202 ER PT J AU Orasanu, J AF Orasanu, J TI Crew collaboration in space: A naturalistic decision-making perspective SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT Workshop on New Directions in Spaceflight Behavioral Health CY DEC 02-03, 2003 CL Davis, CA DE aviation; spaceflight; decision making; problem solving; naturalistic decision making ID ELICITING KNOWLEDGE; EXPERTS AB Successful long-duration space missions will depend on the ability of crewmembers to respond promptly and effectively to unanticipated problems that arise under highly stressful conditions. Naturalistic decision making (NDM) exploits the knowledge and experience of decision makers in meaningful work domains, especially complex sociotechnical systems, including aviation and space. Decision making in these ambiguous, dynamic, high-risk environments is a complex task that involves defining the nature of the problem and crafting a response to achieve one's goals. Goal conflicts, time pressures, and uncertain outcomes may further complicate the process. This paper reviews theory and research pertaining to the NDM model and traces some of the implications for space crews and other groups that perform meaningful work in extreme environments. It concludes with specific recommendations for preparing exploration crews to use NDM effectively. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Orasanu, J (reprint author), NASA, Ames Res Ctr, M-S 262-4, Moffett Field, CA 94035 USA. EM judith.orasanu@nasa.gov NR 88 TC 14 Z9 14 U1 4 U2 9 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B154 EP B163 PG 10 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600021 PM 15943208 ER PT J AU Shepanek, M AF Shepanek, M TI Human behavioral research in space: Quandaries for research subjects and researchers SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT Workshop on New Directions in Spaceflight Behavioral Health CY DEC 02-03, 2003 CL Davis, CA DE human spaceflight; analogue for space missions; human factors; psychology of flight; disincentive to research participation; flight status ID MISSIONS AB With the advent of long-duration spaceflight on board the International Space Station (ISS) and possible future missions beyond low Earth orbit (LEO) such as Mars, it is critical that those at NASA have a realistic assessment of the challenges that will face individuals on long-duration missions so that they can develop preventive and real-time countermeasures to behavioral health issues. While space travellers are very interested in having countermeasures to the deleterious effects of space missions, they have a powerful disincentive to participate in this research if they feel it could in any way negatively affect their flight status. The behavioral issues of isolation and confinement for extended-duration space missions are reviewed. Areas of basic and clinical behavioral research are listed. And the classical clinical model for research is not considered appropriate for the current configuration of the space program. The use of analogue environments and advanced statistical analysis are suggested as ways to address the limited spaceflight research opportunities. The challenge of research subject or patient confidentiality vs. mission safety and issues of personal flight status are addressed. C1 NASA Headquarters, Washington, DC 20546 USA. RP Shepanek, M (reprint author), NASA Headquarters, Code AM,300 E St SW, Washington, DC 20546 USA. EM mshepane@hq.nasa.gov NR 29 TC 5 Z9 7 U1 0 U2 2 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B25 EP B30 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600004 PM 15943191 ER PT J AU Sipes, WE Ark, STV AF Sipes, WE Ark, STV TI Operational Behavioral Health and Performance Resources for international space station crews and families SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT Workshop on New Directions in Spaceflight Behavioral Health CY DEC 02-03, 2003 CL Davis, CA DE behavioral health; space psychology; human spaceflight AB The Behavioral Health and Performance Section (BHP) at NASA Johnson Space Center provides direct and indirect psychological services to the international Space Station (ISS) astronauts and their families. Beginning with the NASA-Mir Program, services available to the crews and families have gradually expanded as experience is gained in long-duration flight. Enhancements to the overall BHP program have been shaped by crewmembers' personal preferences, family requests, specific events during the missions, programmatic requirements, and other lessons learned. The BHP program focuses its work on four areas: operational psychology, behavioral medicine, human-to-system interface, and sleep and circadian. Within these areas of focus are psychological and psychiatric screening for astronaut selection as well as many resources that are available to the crewmembers, families, and other groups such as crew surgeon and various levels of management within NASA. Services include: preflight, in flight, and postflight preparation; training and support; resources from a Family Support Office; in-flight monitoring; clinical care for astronauts and their families; and expertise in the workload and work/rest scheduling of crews on the ISS. Each of the four operational areas is summarized, as are future directions for the BHP program. C1 NASA, Lyndon B Johnson Space Ctr, Wyle Labs, Houston, TX 77058 USA. RP Sipes, WE (reprint author), NASA, Lyndon B Johnson Space Ctr, Wyle Labs, 1290 Hercules Dr, Houston, TX 77058 USA. EM wsipes@wylehou.com NR 18 TC 6 Z9 8 U1 1 U2 5 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B36 EP B41 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600006 PM 15943193 ER PT J AU Willams, RS Davis, JR AF Willams, RS Davis, JR TI A critical strategy: Ensuring behavioral health during extended-duration space missions SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Editorial Material C1 NASA HQ, Off Chief Hlth & Med Officer, Washington, DC 20546 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Willams, RS (reprint author), NASA HQ, Off Chief Hlth & Med Officer, 300 E St SW, Washington, DC 20546 USA. EM desmond.j.lugg@nasa.gov NR 5 TC 5 Z9 5 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B1 EP B2 PG 2 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600001 PM 15943188 ER PT J AU Wood, J Schmidt, L Lugg, D Ayton, J Phillips, T Shepanek, M AF Wood, J Schmidt, L Lugg, D Ayton, J Phillips, T Shepanek, M TI Life, survival, and behavioral health in small closed communities: 10 years of studying isolated antarctic groups SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT Workshop on New Directions in Spaceflight Behavioral Health CY DEC 02-03, 2003 CL Davis, CA DE behavioral health; Antarctica; extreme environments; closed communities; social environments; pooled time-series regressions; hierarchical statistical models; content analysis AB In the late 1980s the Australian Antarctic Division collaborated with NASA to use the Australian National Antarctic Research Expeditions' (ANARE) stations to pursue research of benefit to both programs. This article outlines the data collection efforts, the development of analyses, and selected results, and describes some of the benefits for the aerospace, health, and environmental psychology communities. The Behavior and Performance Laboratory at Johnson Space Center developed a questionnaire to sample broadly the many aspects of life in extreme environments analogous to space missions. Data were collected from volunteers involved in various ANAREs conducted from 1994 to 2003. Pool-timed series regression, hierarchical models, and content analysis have all enhanced the understanding of the kinds of psychosocial variables relevant in extreme environments, and how these variables relate to each other; examples are given. Observations gathered over the last 10 yr comprise a unique, comprehensive, and advanced representation of psychosocial factors in this extreme environment and provide a strong base for future research and application. C1 NASA HQ, Off Chief Hlth & Med Officer, Washington, DC 20546 USA. Wyle Labs, Houston, TX USA. Baylor Coll Med, NSBRI, JSC, Houston, TX 77030 USA. Australian Antarctic Div, Kingston, Tas, Australia. NIH, Bethesda, MD 20892 USA. RP Lugg, D (reprint author), NASA HQ, Off Chief Hlth & Med Officer, 300 E St SW, Washington, DC 20546 USA. EM desmond.j.lugg@nasa.gov NR 13 TC 9 Z9 11 U1 1 U2 3 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JUN PY 2005 VL 76 IS 6 SU S BP B89 EP B93 PG 5 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 933GJ UT WOS:000229616600014 PM 15943201 ER PT J AU Jonsson, H Heisler, M Reddy, GV Agrawal, V Gor, V Shapiro, BE Mjolsness, E Meyerowitz, EM AF Jonsson, H Heisler, M Reddy, GV Agrawal, V Gor, V Shapiro, BE Mjolsness, E Meyerowitz, EM TI Modeling the organization of the WUSCHEL expression domain in the shoot apical meristem SO BIOINFORMATICS LA English DT Article; Proceedings Paper CT 13th International Conference on Intelligent Systems for Molecular Biology CY JUN 25-29, 2005 CL Detroit, MI SP Int Soc Computat Biol ID STEM-CELL FATE; ARABIDOPSIS; CLAVATA1; GROWTH; LOOP AB Motivation: The above-ground tissues of higher plants are generated from a small region of cells situated at the plant apex called the shoot apical meristem. An important genetic control circuit modulating the size of the Arabidopsis thaliana meristem is a feed-back network between the CLAVATA3 and WUSCHEL genes. Although the expression patterns for these genes do not overlap, WUSCHEL activity is both necessary and sufficient (when expressed ectopically) for the induction of CLAVATA3 expression. However, upregulation of CLAVATA3 in conjunction with the receptor kinase CLAVATA1 results in the downregulation of WUSCHEL. Despite much work, experimental data for this network are incomplete and additional hypotheses are needed to explain the spatial locations and dynamics of these expression domains. Predictive mathematical models describing the system should provide a useful tool for investigating and discriminating among possible hypotheses, by determining which hypotheses best explain observed gene expression dynamics. Results: We are developing a method using in vivo live confocal microscopy to capture quantitative gene expression data and create templates for computational models. We present two models accounting for the organization of the WUSCHEL expression domain. Our preferred model uses a reaction-diffusion mechanism in which an activator induces WUSCHEL expression. This model is able to organize the WUSCHEL expression domain. In addition, the model predicts the dynamical reorganization seen in experiments where cells, including the WUSCHEL domain, are ablated, and it also predicts the spatial expansion of the WUSCHEL domain resulting from removal of the CLAVATA3 signal. C1 Univ Calif Irvine, Sch Informat & Comp Sci, Irvine, CA 92717 USA. Univ Calif Irvine, Inst Genom & Bioinformat, Irvine, CA USA. Lund Univ, Complex Syst Div, Dept Theoret Phys, Lund, Sweden. CALTECH, Div Biol, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Mjolsness, E (reprint author), Univ Calif Irvine, Sch Informat & Comp Sci, Irvine, CA 92717 USA. EM emj@uci.edu RI Meyerowitz, Elliot/A-7118-2009; heisler, marcus/B-9738-2015 OI heisler, marcus/0000-0001-5644-8398 NR 26 TC 49 Z9 53 U1 4 U2 8 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD JUN PY 2005 VL 21 SU 1 BP I232 EP I240 DI 10.1093/bioinformatics/bti1036 PG 9 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA 942HH UT WOS:000230273000026 PM 15961462 ER PT J AU Moles, A Marty, GD AF Moles, A Marty, GD TI Physiological changes in prickly sculpin (Cottus asper) inhabiting a lake used by jet-propelled watercraft SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID CRUDE-OIL; FISH; HISTOPATHOLOGY; HYDROCARBONS; PARASITISM; SEDIMENTS; EXHAUST C1 Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. Univ Calif Davis, Sch Vet Med, Dept Anat, Davis, CA 95616 USA. RP Moles, A (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 15 TC 5 Z9 6 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0007-4861 J9 B ENVIRON CONTAM TOX JI Bull. Environ. Contam. Toxicol. PD JUN PY 2005 VL 74 IS 6 BP 1151 EP 1158 DI 10.1007/s00128-005-0701-4 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 942VT UT WOS:000230311700021 PM 16158854 ER PT J AU Craig, JK Crowder, LB Henwood, TA AF Craig, JK Crowder, LB Henwood, TA TI Spatial distribution of brown shrimp (Farfantepenaeus aztecus) on the northwestern Gulf of Mexico shelf: effects of abundance and hypoxia SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID COD GADUS-MORHUA; HADDOCK MELANOGRAMMUS-AEGLEFINUS; DEPENDENT HABITAT SELECTION; SOUTHEASTERN UNITED-STATES; 1981 TEXAS CLOSURE; PENAEUS-AZTECUS; GEOGRAPHIC-DISTRIBUTION; RELATIVE ABUNDANCE; DISSOLVED-OXYGEN; SOUTHERN GULF AB We used fishery-independent hydrographic and bottom trawl surveys on the northwestern Gulf of Mexico shelf from 1983-2000 to test for density dependence and effects of hypoxia (dissolved oxygen <= 2.0 mg center dot L-1) on the spatial distribution of brown shrimp (Farfantepenaeus aztecus). Spatial distribution of shrimp was positively related to abundance on the Texas shelf but negatively related to abundance on the Louisiana shelf. Density dependence was weak, however, and may have been due to factors other than density-dependent habitat selection. Males were distributed over a broader area and further offshore than were females, though differences in spatial distribution between sexes were not large (10%-15%). Large-scale hypoxia (up to 20 000 km(2)) on the Louisiana shelf occurs in regions of typically high shrimp density and results in substantial habitat loss (up to 25% of the Louisiana shelf), with shifts in distribution and associated high densities both inshore and offshore of the hypoxic region. We discuss these results in terms of the generality of density-dependent spatial distributions in marine populations and potential consequences of habitat loss and associated shifts in distribution due to low dissolved oxygen. C1 Duke Ctr Marine Conservat, Nicholas Sch Environm & Earth Sci, Beaufort, NC 28516 USA. Natl Marine Fisheries Serv, Pascagoula Lab, Pascagoula, MS 39567 USA. RP Craig, JK (reprint author), N Carolina State Univ, Ctr Marine Sci & Technol, 303 Coll Circle, Morehead City, NC 28557 USA. EM kevin.craig@duke.edu NR 72 TC 39 Z9 41 U1 0 U2 13 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD JUN PY 2005 VL 62 IS 6 BP 1295 EP 1308 DI 10.1139/F05-036 PG 14 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 945KC UT WOS:000230500400009 ER PT J AU Martell, SJD Essington, TE Lessard, B Kitchell, JF Walters, CJ Boggs, CH AF Martell, SJD Essington, TE Lessard, B Kitchell, JF Walters, CJ Boggs, CH TI Interactions of productivity, predation risk, and fishing effort in the efficacy of marine protected areas for the central Pacific SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID RECONSTRUCTING ECOSYSTEM DYNAMICS; EXPLOITED ECOSYSTEMS; TUNA; RECRUITMENT; IMPACTS; MODEL; OCEAN; POPULATION; FISHERIES; PATTERNS AB Ecospace biomass-dynamics models for the central North Pacific predict strong space-time variation in abundances of various trophic groups in relation to nutrient-driven patterns in primary production and circulation-driven concentration of production in convergence areas. The model predicts simple patterns in ecosystem organization and abundances along productivity gradients. Predicted patterns are robust to alternative assumptions about how mobile organisms may alter dispersal behavior in relation to local fitness (per capita gain from net food intake minus predation mortality). Large marine protected areas (MPAs) would be needed to rebuild endangered populations and counter impacts of growing fishing effort. We expected that increases in dispersal rate in response to lower food availability and higher predation risk would reduce efficacy of MPAs as a management tool. Instead, simulations indicated that this negative effect may generally be eliminated or even reversed by positive effects of fitness-maximizing behaviors. Interannual variability in ocean circulation can further reduce the efficacy of MPAs; therefore, the dynamic nature of pelagic environments should also be considered in MPA design. Anomalies in ocean circulation may shift productive areas relative to MPA location, resulting in increased fishing mortality and (or) misinterpretation of catch statistics. C1 Univ British Columbia, Fisheries Ctr, Vancouver, BC V6T 1Z4, Canada. Univ Wisconsin, Ctr Limnol, Madison, WI 53706 USA. SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu, HI 96822 USA. RP Martell, SJD (reprint author), Univ British Columbia, Fisheries Ctr, 2204 Main Mall, Vancouver, BC V6T 1Z4, Canada. EM s.martell@fisheries.ubc.ca RI Walters, Carl/D-5714-2012 NR 33 TC 30 Z9 32 U1 2 U2 10 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD JUN PY 2005 VL 62 IS 6 BP 1320 EP 1336 DI 10.1139/F05-114 PG 17 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 945KC UT WOS:000230500400011 ER PT J AU Johnson, PV Kanik, I McConkey, JW Tayal, SS AF Johnson, PV Kanik, I McConkey, JW Tayal, SS TI Collisions of electrons with atomic oxygen: current status SO CANADIAN JOURNAL OF PHYSICS LA English DT Article ID EXCITATION CROSS-SECTIONS; IMPACT DISSOCIATIVE EXCITATION; R-MATRIX CALCULATION; LOW-ENERGY ELECTRONS; E-O SCATTERING; ELASTIC-SCATTERING; MOLECULAR-OXYGEN; NONORTHOGONAL ORBITALS; TRANSITION 1304; OSCILLATOR-STRENGTHS AB In 1990, two significant reviews of electron-atomic-oxygen collision processes were published. Since that time, a large volume of both experimental and theoretical research into these processes has occurred. These data are reviewed and recommendations regarding existing data sets and future research in this area are made. Attention is given to the challenges associated with handling atomic oxygen in terms of both experiment and theory. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Windsor, Dept Phys, Windsor, ON N9B 3P4, Canada. Clark Atlanta Univ, Dept Phys, Atlanta, GA 30314 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Paul.V.Johnson@jpl.nasa.gov RI Johnson, Paul/D-4001-2009 OI Johnson, Paul/0000-0002-0186-8456 NR 87 TC 11 Z9 11 U1 1 U2 2 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0008-4204 EI 1208-6045 J9 CAN J PHYS JI Can. J. Phys. PD JUN PY 2005 VL 83 IS 6 BP 589 EP 616 DI 10.1139/P05-034 PG 28 WC Physics, Multidisciplinary SC Physics GA 945JQ UT WOS:000230499200001 ER PT J AU Kimura, Y Sato, T Kaito, C AF Kimura, Y Sato, T Kaito, C TI Production of diamond and solid-solution nanoparticles in the carbon-silicon system using radio-frequency plasma SO CARBON LA English DT Letter DE diamond; vapor grown carbon; plasma reactions; transmission electron microscopy; infrared spectroscopy ID INTERSTELLAR DIAMONDS; GRAINS; CARBIDE; DUST; METEORITES; ENVELOPES; GROWTH; STARS; FILM C1 Ritsumeikan Univ, Dept Phys, Shiga 5258577, Japan. RP Kimura, Y (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 661, Greenbelt, MD 20771 USA. EM rp092955@se.ritsumei.ac.jp RI Kimura, Yuki/J-9635-2014 OI Kimura, Yuki/0000-0002-9218-7663 NR 20 TC 3 Z9 3 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-6223 J9 CARBON JI Carbon PD JUN PY 2005 VL 43 IS 7 BP 1570 EP 1574 DI 10.1016/j.carbon.2005.01.024 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 928BU UT WOS:000229246900032 ER PT J AU Baines, KH Momary, TW Buratti, BJ Matson, DL Nelson, RM Drossart, P Sicardy, B Formisano, V Bellucci, G Coradini, A Griffith, C Brown, RH Bibring, JP Langevin, Y Capaccioni, F Cerroni, P Clark, RN Combes, M Cruikshank, DP Jaumann, R Mccord, TB Mennella, V Nicholson, PD Sotin, C AF Baines, KH Momary, TW Buratti, BJ Matson, DL Nelson, RM Drossart, P Sicardy, B Formisano, V Bellucci, G Coradini, A Griffith, C Brown, RH Bibring, JP Langevin, Y Capaccioni, F Cerroni, P Clark, RN Combes, M Cruikshank, DP Jaumann, R Mccord, TB Mennella, V Nicholson, PD Sotin, C TI The atmospheres of Saturn and Titan in the near-infrared: First results of Cassini/VIMS SO EARTH MOON AND PLANETS LA English DT Article; Proceedings Paper CT Saturn Universe Workshop CY OCT, 2004 CL Capri, ITALY ID TEMPERATURES; ABSORPTION; EMISSION; METHANE; SYSTEM; WINDS; SPOTS; MODEL AB The wide spectral coverage and extensive spatial, temporal, and phase-angle mapping capabilities of the Visual Infrared Mapping Spectrometer (VIMS) onboard the Cassini-Huygens Orbiter are producing fundamental new insights into the nature of the atmospheres of Saturn and Titan. For both bodies, VIMS maps over time and solar phase angles provide information for a multitude of atmospheric constituents and aerosol layers, providing new insights into atmospheric structure and dynamical and chemical processes. For Saturn, salient early results include evidence for phosphine depletion in relatively dark and less cloudy belts at temperate and mid-latitudes compared to the relatively bright and cloudier Equatorial Region, consistent with traditional theories of belts being regions of relative downwelling. Additional Saturn results include (1) the mapping of enhanced trace gas absorptions at the south pole, and (2) the first high phase-angle, high-spatial-resolution imagery of CH4 fluorescence. An additional fundamental new result is the first nighttime near-infrared mapping of Saturn, clearly showing discrete meteorological features relatively deep in the atmosphere beneath the planet's sunlit haze and cloud layers, thus revealing a new dynamical regime at depth where vertical dynamics is relatively more important than zonal dynamics in determining cloud morphology. Zonal wind measurements at deeper levels than previously available are achieved by tracking these features over multiple days, thereby providing measurements of zonal wind shears within Saturn's troposphere when compared to cloudtop movements measured in reflected sunlight. For Titan, initial results include (1) the first detection and mapping of thermal emission spectra of CO, CO2, and CH3D on Titan's nightside limb, (2) the mapping of CH4 fluorescence over the dayside bright limb, extending to similar to 750 km altitude, (3) wind measurements of similar to 0.5 ms(-1), favoring prograde, from the movement of a persistent (multiple months) south polar cloud near 88 degrees S latitude, and (4) the imaging of two transient mid-southern-latitude cloud features. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Observ Paris, Meudon, France. CNR, Ist Fis Spazio Interplanetario, Rome, Italy. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Paris, Inst Astrophys Spatiale, F-75252 Paris, France. CNR, Ist Astrofis Spaziale & Fis Cosm, Rome, Italy. US Geol Survey, Denver, CO 80225 USA. CNRS, Dept Rech Spatial, Meudon, France. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. DLR, Inst Planetary Explorat, Cologne, Germany. Univ Washington, Dept Earth & Space Sci, Washington, DC USA. Osserv Astron Capodimonte, INAF, Catania, Italy. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Nantes, Lab Planetol & Geodinam, Nantes, France. RP Baines, KH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM kbaines@aloha.jpl.nasa.gov OI Cerroni, Priscilla/0000-0003-0239-2741; Bellucci, Giancarlo/0000-0003-0867-8679; Capaccioni, Fabrizio/0000-0003-1631-4314 NR 28 TC 39 Z9 39 U1 1 U2 10 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PD JUN PY 2005 VL 96 IS 3-4 BP 119 EP 147 DI 10.1007/s11038-005-9058-2 PG 29 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 038VG UT WOS:000237257000004 ER PT J AU Spilker, LJ Pilorz, SH Edgington, SG Wallis, BD Brooks, SM Pearl, JC Flasar, FM AF Spilker, LJ Pilorz, SH Edgington, SG Wallis, BD Brooks, SM Pearl, JC Flasar, FM TI Cassini CIRS observations of a roll-off in Saturn ring spectra at submillimeter wavelengths SO EARTH MOON AND PLANETS LA English DT Article; Proceedings Paper CT Saturn Universe Workshop CY OCT, 2004 CL Capri, ITALY DE Cassini; planetary rings; Saturn's rings; thermal infrared ID INFRARED OBSERVATIONS; VOYAGER-1; SYSTEM AB The Cassini Composite Infrared Spectrometer (CIRS) spatially resolved Saturn's main rings in the far-infrared, measuring the spectrum from 20 to 400 wavenumbers (cm(-1)) (tens of microns to submillimeter wavelengths). We find a spectral roll-off below 50 cm(-1) (200 mu m) for each of the A, B and C rings. From these data we derive temperatures and emissivities for each ring. Mie calculations of individual water ice particles show a natural variation in the optical properties of the rings similar to the roll-off we observe in our data. A simple radiative transfer model placing a distribution of water ice particles randomly in a layer provides a good fit to the data and illustrates one possible interpretation of the results. This is most likely only part of the explanation for the roll-off effect as the impact of shape, surface, and composition variations have been left for future analysis. C1 Jet Propuls Lab, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Spilker, LJ (reprint author), Jet Propuls Lab, Pasadena, CA 91125 USA. EM Linda.J.Spilker@jpl.nasa.gov RI Flasar, F Michael/C-8509-2012 NR 21 TC 19 Z9 19 U1 1 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PD JUN PY 2005 VL 96 IS 3-4 BP 149 EP 163 DI 10.1007/s11038-005-9060-8 PG 15 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 038VG UT WOS:000237257000005 ER PT J AU Hazen, RM AF Hazen, RM TI Genesis: Rocks, minerals, and the geochemical origin of life SO ELEMENTS LA English DT Article DE origin of life; biogenesis; metabolism; genetics; adsorption ID MONOLAYERS; ADSORPTION; MOLECULES; SURFACES; AMINO AB ife arose on the young Earth as a natural chemical process. More than half a century of experimental research has underscored the dynamic interactions of atmosphere, oceans, and rocks that fostered this ancient transition from geochemistry to biochemistry. Researchers on the origin of life now conclude that rocks and minerals must have played key roles in virtually every phase of life's emergence-they catalyzed the synthesis of key biomolecules; they selected, protected, and concentrated those molecules; they jump-started metabolism; and they may even have acted as life's first genetic system. C1 Carnegie Inst, Geophys Lab, Washington, DC 20015 USA. NASA, Astrobiol Inst, Washington, DC 20015 USA. RP Hazen, RM (reprint author), Carnegie Inst, Geophys Lab, 5251 Broad Branch Rd NW, Washington, DC 20015 USA. EM r.hazen@gl.ciw.edu NR 17 TC 17 Z9 18 U1 1 U2 11 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 1811-5209 J9 ELEMENTS JI Elements PD JUN PY 2005 VL 1 IS 3 BP 135 EP 137 DI 10.2113/gselements.1.3.135 PG 3 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 010DE UT WOS:000235166300002 ER PT J AU Yang, RG Chen, G Kumar, AR Snyder, GJ Fleurial, JP AF Yang, RG Chen, G Kumar, AR Snyder, GJ Fleurial, JP TI Transient cooling of thermoelectric coolers and its applications for microdevices SO ENERGY CONVERSION AND MANAGEMENT LA English DT Article DE thermoelectric; thermal management; transient cooling; microdevice; thermoelectric cooler ID PELTIER JUNCTIONS; CURRENT PULSE; OPERATION; BEHAVIOR AB If a current pulse with a magnitude several times higher than the steady state optimum current is applied to a thermoelectric cooler, an instantaneously lower temperature than that reachable at the steady state can be obtained. Most previous studies of this transient cooling effect focus on the minimum temperature achievable for free standing thermoelectric (TE) elements. In this work, we systematically study the transient response of thermoelectric coolers with and without mass loads through examination of both the minimum temperature reached and the time constants involved in the cooling and the recovering stages. For integrated thermoelectric cooler-passive mass load systems, two distinguishable cooling regimes, uniform cooling and interfacial cooling, are identified, and the criterion for utilization of the transient cooling effect is established based on the time constants. Although the results of this work are generally applicable, the discussions are geared towards cooling of microdevices that are of current interests. (C) 2004 Elsevier Ltd. All rights reserved. C1 MIT, Dept Engn Mech, Cambridge, MA 02139 USA. Allegro MicroSyst Inc, Worcester, MA 01606 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yang, RG (reprint author), MIT, Dept Engn Mech, 77 Massachusetts Ave,Room 7-049, Cambridge, MA 02139 USA. EM ronggui@mit.edu RI Snyder, G. Jeffrey/E-4453-2011; Yang, Ronggui/H-1278-2011; Chen, Gang/J-1325-2014; Snyder, G/I-2263-2015 OI Snyder, G. Jeffrey/0000-0003-1414-8682; Chen, Gang/0000-0002-3968-8530; NR 18 TC 55 Z9 59 U1 2 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0196-8904 J9 ENERG CONVERS MANAGE JI Energy Conv. Manag. PD JUN PY 2005 VL 46 IS 9-10 BP 1407 EP 1421 DI 10.1016/j.enconman.2004.07.004 PG 15 WC Thermodynamics; Energy & Fuels; Mechanics SC Thermodynamics; Energy & Fuels; Mechanics GA 897TJ UT WOS:000227027800006 ER PT J AU Ooi, TK Gilbert, JA Bower, MV Vaughan, RE Engberg, RC AF Ooi, TK Gilbert, JA Bower, MV Vaughan, RE Engberg, RC TI Modal analysis of lightweight graphite reinforced silica/polymer matrix composite plates SO EXPERIMENTAL MECHANICS LA English DT Article DE composite materials; cementitious composites; modal analysis; structural testing; finite element modeling AB In this paper we describe how finite element and experimental modal analyses can be used to characterize the dynamic behavior of plates made from a new class of graphite reinforced silica/polymer matrix composite (GRSPMC) materials. An agreement is obtained between both methods, and the results show that GRSPMC materials can be modeled and tested using tools similar to those applied to the study of classical composite laminates. C1 Univ Alabama, Dept Mech & Aerosp Engn, Huntsville, AL 35899 USA. Struct & Mat Div, Aviat Engn Directorate, Redstone Arsenal, AL USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Ooi, TK (reprint author), Univ Alabama, Dept Mech & Aerosp Engn, Huntsville, AL 35899 USA. EM jag@eng.uah.edu NR 4 TC 1 Z9 1 U1 0 U2 0 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD JUN PY 2005 VL 45 IS 3 BP 221 EP 225 DI 10.1177/0014485105053800 PG 5 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA 926WH UT WOS:000229153900004 ER PT J AU Morrison, CR Provenza, A Kurkov, A Montague, G Duffy, K Mehmed, O Johnson, D Jansen, R AF Morrison, CR Provenza, A Kurkov, A Montague, G Duffy, K Mehmed, O Johnson, D Jansen, R TI Fully suspended, five-axis, three-magnetic-bearing dynamic spin rig with forced excitation SO EXPERIMENTAL MECHANICS LA English DT Article DE magnetic bearing; thrust bearing; active magnetic bearing; five-axis magnetic bearing; fully suspended rotor AB A significant advancement in the dynamic spin rig (DSR), i.e., the five-axis, three-magnetic-bearing DSR, is used to perform vibration tests of turbomachinery blades and components under rotating and non-rotating conditions in a vacuum. The rig has three magnetic bearings as its critical components: two heteropolar radial active magnetic bearings and a magnetic thrust bearing. The bearing configuration allows full vertical rotor magnetic suspension along with a feed-forward control feature, which enables the excitation of various modes of vibration in the bladed disk test articles. The theoretical, mechanical, electrical, and electronic aspects of the rig are discussed. Also presented are the forced-excitation results of a fully levitated, rotating and non-rotating, unbladed rotor and a fully levitated, rotating and non-rotating, bladed rotor in which a pair of blades were arranged 1800 apart from each other. These tests include the "bounce" mode excitation of the rotor in which the rotor was excited at the blade natural frequency of 144 Hz. The rotor natural mode frequency of 355 Hz was discerned from the plot of acceleration versus frequency. For non-rotating blades, a blade-tip excitation amplitude of approximately 100 g A(-1) as achieved at the first-bending critical (&SIM; 144 Hz) and at the first-torsional and second-bending blade modes. A blade-tip displacement of 1.778 x 10(-3)m (70 mils) was achieved at the first-bending critical by exciting the blades at a forced-excitation phase angle of 901 relative to the vertical plane containing the blades while simultaneously rotating the shaft at 3000 rpm. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Toledo, Toledo, OH 43606 USA. RP Morrison, CR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM carlos.r.morrison@nasa.gov NR 9 TC 6 Z9 6 U1 1 U2 4 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD JUN PY 2005 VL 45 IS 3 BP 226 EP 237 DI 10.1007/BF02427946 PG 12 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA 926WH UT WOS:000229153900005 ER PT J AU Treude, T Niggemann, J Kallmeyer, J Wintersteller, P Schubert, CJ Boetius, A Jorgensen, BB AF Treude, T Niggemann, J Kallmeyer, J Wintersteller, P Schubert, CJ Boetius, A Jorgensen, BB TI Anaerobic oxidation of methane and sulfate reduction along the Chilean continental margin SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SEDIMENTARY ORGANIC-MATTER; MARINE-SEDIMENTS; BLACK-SEA; ATLANTIC; NAMIBIA; RATES; METHANOGENESIS; CONSORTIUM; CARBONATES; WATERS AB Anaerobic oxidation of methane (AOM) and sulfate reduction (SR) were investigated in sediments of the Chilean upwelling region at three stations between 800 and 3000 In water depth. Major goals of this study were to quantify and evaluate rates of AOM and SR in a coastal marine upwelling system with high organic input, to analyze the impact of AOM on the methane budget, and to determine the contribution of AOM to SR within the sulfate-methane transition zone (SMT). Furthermore, we investigated the formation of authigenic carbonates correlated with AOM. We determined the vertical distribution of AOM and SR activity, methane, sulfate, sulfide, pH, total chlorins, and a variety of other geochemical parameters. Depth-integrated rates of AOM within the SMT were between 7 and 1124 mmol m(-2) a(-1), effectively removing methane below the sediment-water interface. Single measurements revealed AOM peaks of 2 to 51 nmol cm(-3) d(-1), with highest rates at the shallowest station (800 m). The methane turnover was higher than in other diffusive systems of similar ocean depth. This higher turnover was most likely due to elevated organic matter input in this upwelling region offering significant amounts of substrates for methanogenesis. SR within the SMT was mostly fuelled by methane. AOM led to the formation of isotopically light DIC (delta(13)C: -24.6 parts per thousand VPDB) and of distinct layers of authigenic carbonates (delta(13)C: - 14.6 parts per thousand VPDB). Copyright (c) 2005 Elsevier Ltd. C1 Max Planck Inst Marine Microbiol, Dept Biogeochem, D-28359 Bremen, Germany. Univ Rhode Isl, NASA, Astrobiol Inst, Narragansett, RI 02882 USA. RF Forschundsschiffahrt GmbH, D-28023 Bremen, Germany. Swiss Fed Inst Environm Sci & Technol, Limnol Res Ctr, CH-6047 Kastanienbaum, Switzerland. Int Jacobs Univ Bremen, D-28759 Bremen, Germany. RP Treude, T (reprint author), Max Planck Inst Marine Microbiol, Dept Biogeochem, Celsiusstr 1, D-28359 Bremen, Germany. EM ttreude@mpi-bremen.de RI Kallmeyer, Jens/I-3554-2012; Jorgensen, Bo/C-2214-2013; Boetius, Antje/D-5459-2013; OI Kallmeyer, Jens/0000-0002-6440-1140; Jorgensen, Bo/0000-0001-9398-8027; Boetius, Antje/0000-0003-2117-4176; Wintersteller, Paul/0000-0002-4834-7965 NR 54 TC 95 Z9 111 U1 6 U2 30 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUN 1 PY 2005 VL 69 IS 11 BP 2767 EP 2779 DI 10.1016/j.gca.2005.01.002 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 935DJ UT WOS:000229759400006 ER PT J AU Lerner, NR Cooper, GW AF Lerner, NR Cooper, GW TI Iminodicarboxylic acids in the Murchison meteorite: Evidence of Strecker reactions SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID CARBONACEOUS CHONDRITES; ISOTOPIC ANALYSES; AMINO-ACIDS; DERIVATIVES; AMMONIA AB alpha-Amino acids and alpha-hydroxy acids are well known constituents of several carbonaceous meteorites. One proposed mechanism of their formation is the reactions of CN(-), NH(3), aldehydes and ketones in aqueous solution, a Strecker-like synthesis. Iminodicarboxylic acids, relatively unusual in molecular structure, are significant by-products of laboratory Strecker syntheses of alpha-amino acids. It is therefore notable that an analogous suite of imino acids has not been reported in CM2 chondrites where amino and hydroxy acids are abundant. In this work, aqueous extracts of the Murchison meteorite were examined for the presence of imino acids; GC-MS and HPLC molecular analyses revealed a complex suite of such acids. With the exception of one of the seven-carbon members, all of the C4 through C7 imino acids were observed in Murchison. These observations suggest that the Strecker synthesis made, at least, some contribution to the formation of extraterrestrial amino acids. Copyright (c) 2005 Elsevier Ltd. C1 NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. RP Cooper, GW (reprint author), NASA, Ames Res Ctr, Exobiol Branch, MS 239-4, Moffett Field, CA 94035 USA. EM gcooper@mail.arc.nasa.gov NR 31 TC 25 Z9 25 U1 2 U2 11 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 JUN 1 PY 2005 VL 69 IS 11 BP 2901 EP 2906 DI 10.1016/j.gca.2004.12.023 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 935DJ UT WOS:000229759400015 ER PT J AU Hulot, G Bouligand, C AF Hulot, G Bouligand, C TI Statistical palaeomagnetic field modelling and symmetry considerations SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE dynamo theory; geomagnetism; geostatistics; palaeomagnetisin; spherical harmonics; statistical methods ID GEOMAGNETIC SECULAR VARIATION; PAST 5 MYR; PALEOSECULAR VARIATION; MAGNETIC-FIELD; PALAEOSECULAR VARIATION; 0-5 MA; TIME; GEODYNAMO; REVERSALS; DATABASE AB In the present paper, we address symmetry issues in the context of the so-called giant gaussian process (GGP) modelling approach, currently used to statistically analyse the present and past magnetic field of the Earth at times of stable polarity. We first recall the principle of GGP modelling, and for the first time derive the complete and exact constraints a GGP model should satisfy if it is to satisfy statistical spherical, axisymmetrical or equatorially symmetric properties. We note that as often correctly claimed by the authors, many simplifying assumptions used so far to ease the GGP modelling amount to make symmetry assumptions, but not always exactly so, because previous studies did not recognize that symmetry assumptions do not systematically require a lack of cross-correlations between Gauss coefficients. We further note that GGP models obtained so far for the field over the past 5 Myr clearly reveal some spherical symmetry breaking properties in both the mean and the fluctuating field (as defined by the covariance matrix of the model) and some equatorial symmetry breaking properties in the mean field. Non-zonal terms found in the mean field of some models and mismatches between variances defining the fluctuating field (in models however not defined in a consistent way) would further suggest that axial symmetry also is broken. The meaning of this is discussed. Spherical symmetry breaking trivially testifies for the influence of the rotation of the Earth on the geodynamo (a long-recognized fact). Axial symmetry breaking, if confirmed, could hardly be attributed to anything else but some influence of the core-mantle boundary (CMB) conditions on the geodynamo (also a well-known fact). By contrast, equatorial symmetry breaking (in particular the persistence of an axial mean quadrupole) may not trivially be considered as evidence of some influence of CMB conditions. To establish this, one would need to better investigate whether or not this axial quadrupole has systematically reversed its polarity with the axial dipole in the past and whether dynamo simulations run under equatorial symmetric CMB conditions display additional transitions (mirror transitions, which we describe) only allowed in such instances. This remains to be fully investigated. C1 Inst Phys Globe, CNRS, UMR 7577, Dept Geomagnetisme & Paleomagnetisme, F-75252 Paris, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hulot, G (reprint author), Inst Phys Globe, CNRS, UMR 7577, Dept Geomagnetisme & Paleomagnetisme, 4 Pl Jussieu, F-75252 Paris, France. EM gh@ipgp.jussieu.fr RI Hulot, Gauthier/A-5627-2011 NR 38 TC 12 Z9 12 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD JUN PY 2005 VL 161 IS 3 BP 591 EP 602 DI 10.1111/j.1365-246X.2005.02612.x PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 935OX UT WOS:000229792700003 ER PT J AU Bouligand, C Hulot, G Khokhlov, A Glatzmaier, GA AF Bouligand, C Hulot, G Khokhlov, A Glatzmaier, GA TI Statistical palaeomagnetic field modelling and dynamo numerical simulation SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE dynamo theory; geomagnetism; geostatistics; palaeomagnetism; spherical harmonics; statistical methods ID AVERAGED GEOMAGNETIC-FIELD; CORE-MANTLE INTERACTIONS; BOUNDARY HEAT-FLOW; SECULAR VARIATION; MAGNETIC-FIELD; PALEOSECULAR VARIATION; AXIAL DIPOLE; 0-5 MA; GEODYNAMO; REVERSALS AB By relying on two numerical dynamo simulations for which such investigations are possible, we test the validity and sensitivity of a statistical palaeomagnetic field modelling approach known as the giant gaussian process (GGP) modelling approach. This approach is currently used to analyse palaeomagnetic data at times of stable polarity and infer some information about the way the main magnetic field (MF) of the Earth has been behaving in the past and has possibly been influenced by core-mantle boundary (CMB) conditions. One simulation has been run with homogeneous CMB conditions, the other with more realistic non-homogeneous symmetry breaking CMB conditions. In both simulations, it is found that, as required by the GGP approach, the field behaves as a short-term memory process. Some severe non-stationarity is however found in the non-homogeneous case, leading to very significant departures of the Gauss coefficients from a Gaussian distribution, in contradiction with the assumptions underlying the GGP approach. A similar but less severe non-stationarity is found in the case of the homogeneous simulation, which happens to display a more Earth-like temporal behaviour than the non-homogeneous case. This suggests that a GGP modelling approach could nevertheless be applied to try and estimate the mean p and covariance matrix gamma(tau) (first- and second-order statistical moments) of the field produced by the geodynamo. A detailed study of both simulations is carried out to assess the possibility of detecting statistical symmetry breaking properties of the underlying dynamo process by inspection of estimates of mu and gamma(tau). As expected (because of the role of the rotation of the Earth in the dynamo process), those estimates reveal spherical symmetry breaking properties. Equatorial symmetry breaking properties are also detected in both simulations, showing that such symmetry breaking properties can occur spontaneously under homogeneous CMB conditions. By contrast axial symmetry breaking is detected only in the non-homogenous simulation, testifying for the constraints imposed by the CMB conditions. The signature of this axial symmetry breaking is however found to be much weaker than the signature of equatorial symmetry breaking. We note that this could be the reason why only equatorial symmetry breaking properties (in the form of the well-known axial quadrupole term in the time-averaged field) have unambiguously been found so far by analysing the real data. However, this could also be because those analyses have all assumed to simple a form for gamma(tau) when attempting to estimate mu. Suggestions are provided to make sure future attempts of GGP modelling with real data are being carried out in a more consistent and perhaps more efficient way. C1 Inst Phys Globe, CNRS, UMR 7577, Dept Geomagnetisme & Paleomagnetisme, F-75252 Paris, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Int Inst Earthquake Predict Theory & Math Geophy, Moscow 117556, Russia. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. RP Bouligand, C (reprint author), Inst Phys Globe, CNRS, UMR 7577, Dept Geomagnetisme & Paleomagnetisme, 4 Pl Jussieu, F-75252 Paris, France. EM gh@ipgp.jussieu.fr RI Hulot, Gauthier/A-5627-2011; Khokhlov, Andrey/H-4712-2016 NR 36 TC 18 Z9 20 U1 0 U2 5 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD JUN PY 2005 VL 161 IS 3 BP 603 EP 626 DI 10.1111/j.1365-246X.2005.02613.x PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 935OX UT WOS:000229792700004 ER PT J AU Burch, JL Goldstein, J Hill, TW Young, DT Crary, FJ Coates, AJ Andre, N Kurth, WS Sittler, EC AF Burch, JL Goldstein, J Hill, TW Young, DT Crary, FJ Coates, AJ Andre, N Kurth, WS Sittler, EC TI Properties of local plasma injections in Saturn's magnetosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID IO TORUS; INTERCHANGE; TRANSPORT AB Electron and ion drift dispersion events are often observed by the Cassini Plasma Spectrometer ( CAPS) in the inner magnetosphere of Saturn ( 5 to 10 R(S)). These events appear to result from azimuthally-limited injections of plasma and persist for at least several hours. During this time, the events can be analyzed to obtain information on the time and azimuthal location of the injections. The CAPS data show evidence of both remote and local injections. In this paper a conceptual model of Saturnian centrifugal interchange is developed based on the characteristics of the local injections. C1 SW Res Inst, San Antonio, TX 78228 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Burch, JL (reprint author), SW Res Inst, PO Drawer 28510, San Antonio, TX 78228 USA. EM jburch@swri.edu; jgoldstein@swri.edu; hill@rice.edu; dyoung@swri.edu; fcrary@swri.edu; ajc@mssl.ucl.ac.uk; nicolas.andre@cesr.fr; william-kurth@uiowa.edu; edward.c.sittler@nasa.gov RI Coates, Andrew/C-2396-2008; OI Coates, Andrew/0000-0002-6185-3125; Kurth, William/0000-0002-5471-6202 NR 12 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 JUN 1 PY 2005 VL 32 IS 14 AR L14S02 DI 10.1029/2005GL022611 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 936BP UT WOS:000229828300001 ER PT J AU Jin, JJ Semeniuk, K Jonsson, AI Beagley, SR McConnell, JC Boone, CD Walker, KA Bernath, PF Rinsland, CP Dupuy, E Ricaud, P De la Noe, J Urban, J Murtagh, D AF Jin, JJ Semeniuk, K Jonsson, AI Beagley, SR McConnell, JC Boone, CD Walker, KA Bernath, PF Rinsland, CP Dupuy, E Ricaud, P De la Noe, J Urban, J Murtagh, D TI Co-located ACE-FTS and Odin/SMR stratospheric-mesospheric CO 2004 measurements and comparison with a GCM SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MIDDLE ATMOSPHERE MODEL; CLIMATOLOGY AB This paper presents a comparison of co-located and near simultaneous CO measurements from January to May, 2004 and from the Arctic to southern polar regions using the ACE-FTS, in solar occultation mode, and the Odin/SMR, which measures atmospheric emission. We find that there is excellent agreement between the two instruments at the locations investigated over 4 orders of magnitude from the lower stratosphere to the lower thermosphere. There is also good agreement with the CMAM model simulation from 20 km to 90 km in sub-tropical and tropical latitudes but poorer agreement in the upper stratosphere and lower mesosphere in winter polar regions. For the Arctic in March 2004 this can be attributed, at least partly, to the unique dynamical processes in the stratosphere in the winter of 2003 - 2004. Clearly CO measurements from these instruments will provide a useful tool for testing model transport from the troposphere to the thermosphere. C1 York Univ, Dept Earth & Space Sci & Engn, Toronto, ON M3J 1P3, Canada. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Observ Aquitain Sci Univers, F-33270 Floirac, France. Chalmers, Dept Radio & Space Sci, SE-41286 Gothenburg, Sweden. RP Jin, JJ (reprint author), York Univ, Dept Earth & Space Sci & Engn, Toronto, ON M3J 1P3, Canada. EM jianjun@yorku.ca RI The Odin satellite, aeronomy mission/F-1671-2011; Bernath, Peter/B-6567-2012; Jin, Jianjun/G-8357-2012; Jonsson, Andreas/B-3887-2013; Urban, Jo/F-9172-2010; Murtagh, Donal/F-8694-2011 OI Bernath, Peter/0000-0002-1255-396X; Jonsson, Andreas/0000-0003-0321-6213; Urban, Jo/0000-0001-7026-793X; Murtagh, Donal/0000-0003-1539-3559 NR 16 TC 25 Z9 25 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 JUN 1 PY 2005 VL 32 IS 15 AR L15S03 DI 10.1029/2005GL022433 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 936BR UT WOS:000229828600003 ER PT J AU McMillan, WW Barnet, C Strow, L Chahine, MT McCourt, ML Warner, JX Novelli, PC Korontzi, S Maddy, ES Datta, S AF McMillan, WW Barnet, C Strow, L Chahine, MT McCourt, ML Warner, JX Novelli, PC Korontzi, S Maddy, ES Datta, S TI Daily global maps of carbon monoxide from NASA's Atmospheric Infrared Sounder SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPOSPHERIC OZONE; TROPICAL ATLANTIC; SOUTHERN AFRICA; AIRS/AMSU/HSB; PERSPECTIVE; RETRIEVAL; PRODUCTS; CO AB We present the first observations of tropospheric carbon monoxide (CO) by the Atmospheric Infrared Sounder (AIRS) onboard NASA's Aqua satellite. AIRS daily coverage of similar to 70% of the planet represents a significant evolutionary advance in satellite trace gas remote sensing. Tropospheric CO abundances are retrieved from AIRS 4.55 mu m spectral region using the full AIRS retrieval algorithm run in a research mode. The presented AIRS daily global CO maps from 22 29 September 2002 show large-scale, long-range transport of CO from anthropogenic and natural sources, most notably from biomass burning. The sequence of daily maps reveal CO advection from Brazil to the South Atlantic in qualitative agreement with previous observations. Forward trajectory analysis confirms this scenario and indicates much longer range transport into the southern Indian Ocean. Preliminary comparisons to in situ aircraft profiles indicate AIRS CO retrievals are approaching the 15% accuracy target set by pre-launch simulations. C1 UMBC, Dept Phys, Baltimore, MD 21205 USA. NOAA, NESDIS ORA, Camp Springs, MD 20746 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Maryland, Joint Ctr Earth Syst Technol, College Pk, MD 20742 USA. NOAA, CMDL, Boulder, CO USA. RP McMillan, WW (reprint author), UMBC, Dept Phys, 1000 Hilltop Circle, Baltimore, MD 21205 USA. EM mcmillan@umbc.edu RI Barnet, Christopher/F-5573-2010; Maddy, Eric/G-3683-2010 OI Maddy, Eric/0000-0003-1151-339X NR 25 TC 95 Z9 99 U1 3 U2 12 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 JUN 1 PY 2005 VL 32 IS 11 AR L11801 DI 10.1029/2004GL021821 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 936BL UT WOS:000229827900001 ER PT J AU Nassar, R Bernath, PF Boone, CD Manney, GL McLeod, SD Rinsland, CP Skelton, R Walker, KA AF Nassar, R Bernath, PF Boone, CD Manney, GL McLeod, SD Rinsland, CP Skelton, R Walker, KA TI Stratospheric abundances of water and methane based on ACE-FTS measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPICAL TROPOPAUSE TEMPERATURES; VAPOR; TRENDS; OZONE; CLIMATE; HALOE AB We present solar occultation measurements of H2O and CH4 by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). The data used here were selected from occultations spanning February to April 2004 from 0 to 79.8 degrees N. The midlatitude volume mixing ratio (VMR) of potential water is determined as [H2O] + 2[CH4] and from [H2O] versus [CH4] correlations, then used to calculate the VMR of water vapor entering the stratosphere. We obtain 7.14 +/- 0.23 ppm for potential water and 3.65 +/- 0.29 ppm for water entering the stratosphere in 2004 for direct comparison with Atmospheric Trace Molecule Spectroscopy (ATMOS) data ( 1985 - 1994). We find a very small change in potential water and no change in water entering the stratosphere relative to the 1994 ATMOS data, indicating that increases observed by ATMOS and other instruments from that time period have not continued. This halt in stratospheric water vapor increases is consistent with recent water vapor measurements by other instruments. C1 Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. New Mexico Highlands Univ, Las Vegas, NM 87701 USA. CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. EM ray@acebox.uwaterloo.ca; bernath@uwaterloo.ca; cboone@sciborg.uwaterloo.ca; manney@mls.jpl.nasa.gov; sdmcleod@uwaterloo.ca; c.p.rinsland@larc.nasa.gov; skelton@brutus.uwaterloo.ca; kwalker@acebox.uwaterloo.ca RI Bernath, Peter/B-6567-2012 OI Bernath, Peter/0000-0002-1255-396X NR 17 TC 23 Z9 23 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 1 PY 2005 VL 32 IS 15 AR L15S04 DI 10.1029/2005GL022383 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 936BR UT WOS:000229828600001 ER PT J AU Nassar, R Bernath, PF Boone, CD Manney, GL McLeod, SD Rinsland, CP Skelton, R Walker, KA AF Nassar, R Bernath, PF Boone, CD Manney, GL McLeod, SD Rinsland, CP Skelton, R Walker, KA TI ACE-FTS measurements across the edge of the winter 2004 Arctic vortex SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERIC POLAR VORTEX; ATMOS MEASUREMENTS; DESCENT; ABUNDANCES; N2O; CH4; AIR AB Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) solar occultation measurements have been used to create volume mixing ratio (VMR) profiles of H2O, CH4, and N2O inside and outside the 2004 Arctic vortex. Using derived meteorological quantities such as potential vorticity, we have classified 450 occultations ( from February and March 2004 spanning 0 to 79.8 degrees N) as vortex, vortex edge, or extravortex. We plot [CH4] versus [N2O] correlations to display the distinct patterns observed for measurements of different air masses and use these correlations to further classify the extravortex occultations as tropical, subtropical, or midlatitude. Using comparisons between high latitude profiles of [N2O], [CH4], and [H2O] inside and outside the Arctic vortex, we estimate upper stratospheric and lower mesospheric descent rates and find that descent in the winter 2004 Arctic vortex was rapid, with evidence of descent at higher altitudes than in past years. C1 Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. New Mexico Highlands Univ, Las Vegas, NM 87701 USA. CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. EM ray@acebox.uwaterloo.ca; bernath@uwaterloo.ca; cboone@sciborg.uwaterloo.ca; manney@mls.jpl.nasa.gov; sdmcleod@uwaterloo.ca; c.p.rinsland@larc.nasa.gov; skelton@brutus.uwaterloo.ca; kwalker@acebox.uwaterloo.ca RI Bernath, Peter/B-6567-2012; OI Bernath, Peter/0000-0002-1255-396X; Nassar, Ray/0000-0001-6282-1611 NR 14 TC 21 Z9 21 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 JUN 1 PY 2005 VL 32 IS 15 AR L15S05 DI 10.1029/2005GL022671 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 936BR UT WOS:000229828600004 ER PT J AU Semeniuk, K McConnell, JC Jackman, CH AF Semeniuk, K McConnell, JC Jackman, CH TI Simulation of the October-November 2003 solar proton events in the CMAM GCM: Comparison with observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CHEMISTRY AB The FTS instrument on SciSat-I observed over 1 ppmv NOx in the lower polar mesosphere, in mid February of 2004, more than 100 times normal. Using a middle atmosphere GCM we investigate whether solar proton events or subsequent associated aurorae can explain the NOx observations. We find that the solar proton events produce insufficient amounts of NOx, less than 2 ppmv at 90 km. However, it is likely that intense aurorae associated with the Oct. - Nov. 2003 solar storms, and their aftermath, produced thermospheric values of NOx reaching hundreds of ppmv. In addition, from our simulations we infer that NOx rich air must have experienced unusually confined polar night descent in the mesosphere in December and January. C1 York Univ, Dept Earth & Space Sci & Engn, Toronto, ON MJ3 1P3, Canada. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Semeniuk, K (reprint author), York Univ, Dept Earth & Space Sci & Engn, Toronto, ON MJ3 1P3, Canada. EM kirill@nimbus.yorku.ca RI Jackman, Charles/D-4699-2012 NR 13 TC 29 Z9 29 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 JUN 1 PY 2005 VL 32 IS 15 AR L15S02 DI 10.1029/2005GL022392 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 936BR UT WOS:000229828600002 ER PT J AU Abdalla, MO Ganguli, S Abdalla, MA Dean, D Campbell, S AF Abdalla, MO Ganguli, S Abdalla, MA Dean, D Campbell, S TI Environmental durability of polymerization of monomer reactants-type polyimide-clay nanocomposites SO HIGH PERFORMANCE POLYMERS LA English DT Article DE PMR-15; nanocomposites; environmental durability; thermoset ID LAYERED SILICATE NANOCOMPOSITES; BTDA-ODA NANOCOMPOSITES; MECHANICAL-PROPERTIES; CYANATE ESTER; ORGANOCLAY; CHEMISTRY AB The environmental durability of PMR-15 nanocomposites prepared from an unmodified Na+-montmorillonite (PGV) and two organically modified PGV (PGVC10COOH, PGVC12) have been investigated using an accelerated hydrolytic aging test and a long-term thermo-oxidative aging study. PGV was modified with an amino acid (11-amino-undecanoic acid) and a primary amine (dodecylamine). The PGV/PMR-15 nanocomposite exhibited higher moisture gain than the neat resin, while PGVC10COOH, PGVC12/PMR-15 nanocomposites exhibited lower moisture gains. XRD data of the nanocomposites correlated well with the moisture gain data for the nanocomposites. PGVC10COOH and PGVC12/PMR-15 nanocomposites exhibited more than a 50% reduction in the flexural modulus drop off. These results suggest that nanocomposites provide a viable approach in decreasing the susceptibility of PMR-15 to hydrolytic degradation. No improvement in the thermal oxidative stability of the nanocomposites was achieved. This may be attributable to the relatively low thermal stability of the organic modifiers and/or the presence of impurities, which catalyzed the PMR-15 degradation. C1 Univ Alabama, Dept Mat Sci & Engn, Birmingham, AL 35294 USA. Tuskegee Univ, Ctr Adv Mat, Tuskegee, AL 36088 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Dean, D (reprint author), Univ Alabama, Dept Mat Sci & Engn, Birmingham, AL 35294 USA. EM deand@uab.edu NR 26 TC 4 Z9 4 U1 0 U2 2 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 JUN PY 2005 VL 17 IS 2 BP 239 EP 250 DI 10.1177/0954008305044852 PG 12 WC Polymer Science SC Polymer Science GA 929BO UT WOS:000229317300006 ER PT J AU Vasquez, DL Ndalama, T Hirschfeld, DA Sutter, JK AF Vasquez, DL Ndalama, T Hirschfeld, DA Sutter, JK TI Effect of surface modification on adhesion of a metal bond coat to PMR composites SO HIGH PERFORMANCE POLYMERS LA English DT Article DE polyimide; composite; surface; RF plasma; UV/ozone; chemical vapor deposition; silica; etching; coatings ID PLASMA AB Graphite-reinforced polyimide composites are being considered for use in advanced turbine engines, which require the application of wear- and oxidation-resistant coatings onto the composites. To ensure in-service adhesion of a hard, protective ceramic or cermet coating to these composites, it is first necessary to apply a metal bond coat This study examines the effect that a silica layer has on the adhesion of a proprietary metal bond coat to PMR-15 and PMR-II-50 composite surfaces. Previous work has shown that radio frequency (RF) oxygen plasma etching was the most effective technique for increasing the surface energy of the composites and plasma-enhanced chemical vapor deposition (PECVD) of silica using tetramethoxysilane (TMOS) produced stoichiometric silica films. In addition, UV/ozone chemical vapor deposition (UVCVD) using tetraethylorthosilicate (TEOS) was also used to deposit silica species on the composite surfaces. The surfaces of PMR-15 and PMR-II-50 samples were modified by the following methods: grit blasting; grit blasting, ultra-violet/ozone (UV/ozone) etch, UVCVD of silic; and grit blasting, RF oxygen plasma etch, PECVD of silica. Adhesion pull tests were conducted and the fracture surfaces were examined using both optical and electron microscopy. PMR-15 samples with PECVD silica showed a significant increase in adhesion when compared with both UVCVD silica and grit blasting only. PMR-II-50 showed no significant difference in the adhesion strength for any surface modification method. Electron microprobe analysis of the fracture surfaces showed no evidence that silica was present on surfaces treated by UVCVD. Analyses also showed that the silica bonded more strongly to both the PMR-15 and PMR-II-50 neat resins than to the graphite fibers. The poor surface quality of PMR-II-50 composites is believed to have a major effect on bond coat adhesion strength. C1 New Mexico Inst Min & Technol, Socorro, NM 87801 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Hirschfeld, DA (reprint author), New Mexico Inst Min & Technol, Socorro, NM 87801 USA. EM hirsch@nmt.edu NR 8 TC 6 Z9 6 U1 3 U2 9 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 JUN PY 2005 VL 17 IS 2 BP 293 EP 302 DI 10.1177/0954008305050677 PG 10 WC Polymer Science SC Polymer Science GA 929BO UT WOS:000229317300010 ER PT J AU Mest, SC Crown, DA AF Mest, SC Crown, DA TI Millochau crater, Mars: Infilling and erosion of an ancient highland impact crater SO ICARUS LA English DT Article DE crater morphology; geological processes; mars; mars; surface; surfaces; planets ID THERMAL EMISSION SPECTROMETER; TERRESTRIAL PLANETS; MARTIAN HIGHLANDS; WRINKLE RIDGES; HELLAS REGION; MAADIM-VALLIS; EVOLUTION; BASIN; LAKES; SURFACE AB The geology and stratigraphy of Millochau crater (21.4&DEG; S, 275&DEG; W), located in the highlands of Tyrrhena Terra, Mars, are documented through geomorphic analyses and geologic mapping. Crater size-frequency distributions and superposition relationships are used to constrain relative ages of geologic units and determine the timing and duration of the geologic processes that modified Millochau rim materials and emplaced deposits on Millochau's floor. Crater size-frequency distributions show a Middle Noachian age for rim materials and Middle Noachian to Early Hesperian ages for most of the interior deposits. Valley networks and gullies incised within Millochau's rim materials and interior wall, respectively, indicate fluvial activity was an important erosional process. Millochau contains an interior plateau, offset northeast of Millochau's center, which rises up to 400 m above the surrounding crater floor and slopes downward to the south and west. Layers exposed along the northern and eastern scarp boundaries of the plateau are tens to hundreds of meters thick and laterally continuous in MOC images. These layers suggest most materials within Millochau were emplaced by sedimentary processes (e.g., fluvial or eolian), with the potential for lacustrine deposition in shallow transient bodies of water and contributions of volcanic airfall. Mass wasting may have also contributed significant quantities of material to Millochau's interior, especially to the deposits surrounding the plateau. Superposition relationships combined with impact crater statistics indicate that most deposition and erosion of Millochau's interior deposits is ancient, which implies that fluvial activity in this part of Tyrrhena Terra is much older than in the eastern Hellas region. Eolian processes mobilized sediment to form complicated patterns of long- and short-wavelength dunes, whose emplacement is controlled by local topography. These deposits are some of the youngest within Millochau (Amazonian) and eolian modification may be ongoing. © 2004 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. Planetary Sci Inst, Tucson, AZ 85717 USA. RP Mest, SC (reprint author), NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Code 698,Bldg 33,Rm F320, Greenbelt, MD 20771 USA. EM mest@kasei.gsfc.nasa.gov NR 77 TC 12 Z9 12 U1 0 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 JUN PY 2005 VL 175 IS 2 BP 335 EP 359 DI 10.1016/j.icarus.2004.12.008 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 926YH UT WOS:000229159100004 ER PT J AU Temma, T Chanover, NJ Simon-Miller, AA Glenar, DA Hillman, JJ Kuehn, DM AF Temma, T Chanover, NJ Simon-Miller, AA Glenar, DA Hillman, JJ Kuehn, DM TI Vertical structure modeling of Saturn's equatorial region using high spectral resolution imaging SO ICARUS LA English DT Article DE Saturn; atmosphere; atmospheres; structure; photometry ID OPTICAL REFLECTANCE POLARIMETRY; METHANE BAND PHOTOMETRY; CLOUD STRUCTURE; RADIATIVE-TRANSFER; ABSORPTION-COEFFICIENTS; ENERGY-DISTRIBUTIONS; VOYAGER MEASUREMENTS; HELIUM ABUNDANCE; JOVIAN PLANETS; GALILEO PROBE AB A series of narrow-band images of Saturn was acquired on 7-11 February 2002 with an acousto-optic imaging spectrometer (AImS) at about 160 wavelengths between 500 and 950 nm. Our unique data set with high spectral agility and wide spectral coverage enabled us to extensively study the cloud structure and aerosol properties of Saturn's equatorial region at -10&DEG; latitude. Theoretical center-limb profiles based on twelve Cloud models were fit to the observations at 23 wavelengths across the 619-. 727-, and 890-nm methane bands. A simultaneous multiwavelength multivariable fitting algorithm was adopted in varying up to 9 free parameters to efficiently explore the vast multidimensional parameter space, and a total of &SIM; 12,000 initial conditions were tested. From the acceptable ranges of the model parameters, we obtained the following major conclusions: (1) the brightening of Saturn's equatorial region observed near 890 nm in February 2002 (I/F &SIM; 0.25 at the central meridian) results front high altitudes of a stratospheric haze layer (τ &GE; &SIM; 0.05 above &SIM; 0.04-bar level) and an upper tropospheric cloud (τ &SIM; 6 above &SIM; 0.25-bar level), (2) if the upper tropospheric cloud is composed of ammonia ice particles and the Mie theory is applied, the mean particle size is larger than about 0.5 μ m, (3) an optically thick cloud layer exists at a level of 0.5-2.2 bar below the upper cloud deck in Saturn's equatorial region. The ongoing observations by the Cassini spacecraft over wider spectral range and from various phase angles will further constrain Saturn's cloud structure and aerosol properties. © 2004 Elsevier Inc. All rights reserved. C1 New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Pittsburg State Univ, Dept Phys, Pittsburg, KS 66762 USA. RP Temma, T (reprint author), New Mexico State Univ, Dept Astron, MSC 4500,POB 30001, Las Cruces, NM 88003 USA. EM temma@nmsu.edu RI Simon, Amy/C-8020-2012 OI Simon, Amy/0000-0003-4641-6186 NR 55 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 JUN PY 2005 VL 175 IS 2 BP 464 EP 489 DI 10.1016/j.icarus.2004.11.006 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 926YH UT WOS:000229159100014 ER PT J AU Buratti, BJ Hicks, MD Davies, A AF Buratti, BJ Hicks, MD Davies, A TI Spectrophotometry of the small satellites of Saturn and their relationship to Iapetus, Phoebe, and Hyperion SO ICARUS LA English DT Article DE Iapetus; Phoebe; hyperion; Satellites of Saturn ID IRREGULAR SATELLITES; DARK SIDE; LAPETUS; ORIGIN; SPECTRA AB We have obtained broadband spectrophotometric observations of four of the recently discovered small satellites of Saturn (Gladman et al., 2001, Nature 412, 163-166). The new data enable an understanding of the provenance, composition, and interrelationships among these satellites and the other satellites of Saturn, particularly Iapetus, Phoebe, and Hyperion. Temporal coverage of one satellite (S21 Tarvos) was sufficient to determine a partial rotational lightcurve. Our major findings include: (1) the satellites are red and similar in color, comparable to D-type asteroids, some KBOs, Iapetus, and Hyperion; (2) none of the satellites, including those from the "Phoebe Group" has any spectrophotometric relationship to Phoebe; and (3) S21 Tarvos exhibits a rotational lightcurve, although the data are not well-constrained and more observations are required to fit a definitive period. Dust created by meteoritic impacts and ejected from these satellites and additional undiscovered ones may be the source of the exogenous material deposited on the low-albedo side of Iapetus. Recent work which states that the small irregular satellites of Saturn have impacted Phoebe at least 6-7 times in the age of the Solar System (Nesvorny et al., 2003, Astron. J. 126, 398-429), suggests that such collisions may have propelled additional material from both Phoebe and the small irregular satellites toward Iapetus. The accretion of material from outer retrograde satellites may be a process that also occurs on Callisto and the uranian satellites. © 2005 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Palomar Observ, Pasadena, CA 91109 USA. RP Buratti, BJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM bonnie.j.buratti@jpl.nasa.gov NR 30 TC 25 Z9 25 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 JUN PY 2005 VL 175 IS 2 BP 490 EP 495 DI 10.1016/j.icarus.2004.11.024 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 926YH UT WOS:000229159100015 ER PT J AU Artemieva, N Lunine, JI AF Artemieva, N Lunine, JI TI Impact cratering on Titan - II. Global melt, escaping ejecta, and aqueous alteration of surface organics SO ICARUS LA English DT Article DE titan; impact processes; melt; aqueous alteration; ejecta ID HYDRODYNAMIC CODE SOVA; OUTER SOLAR-SYSTEM; COMET; GANYMEDE; ATMOSPHERES; RELAXATION; SATELLITES; RETENTION; ORIGIN; FLOWS AB New three-dimensional hydrodynamic simulations of hypervelocity impacts into the crust of Titan were undertaken to determine the fraction of liquid water generated on the surface of Saturn's largest moon over its history and, hence, the potential for surface-modification of hydrocarbons and nitriles by exposure to liquid water. We model in detail an individual impact event in terms of ejecta produced and melt generated, and use this to estimate melt production over Titan's history, taking into account the total flux of the impactors and its decay over time. Our estimates show that a global melt layer at any time after the very beginning of Titan's history is improbable; but transient melting local to newly formed craters has occurred over large parts of the surface. Local maxima of the melt are connected with the largest impact events. We also calculate the amount of volatiles delivered at the impact with various impact velocities (from 3 km/s for possible Hyperion fragments to 11 km/s for Jupiter family comets) and their retention as a possible source of Titan's atmosphere. We find the probability of impact ejecta escaping Titan with its modern dense and thick atmosphere is rather low, and dispersal of Titan organics throughout the rest of the Solar System requires impactors tens of kilometers in diameter. Water ice melting and exposure of organics to liquid water has been widespread because of impacts, but burial or obscuration of craters by organic deposits or cryovolcanism is aided by viscous relaxation. The largest impactors may breach an ammonia-water mantle layer, creating a circular albedo contrast rather than a crater. © 2004 Elsevier Inc. All rights reserved. C1 Russian Acad Sci, Inst Dynam Geospheres, Moscow 119334, Russia. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. CALTECH, NASA, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Artemieva, N (reprint author), Russian Acad Sci, Inst Dynam Geospheres, Leninsky Pr 38,Bldg 1, Moscow 119334, Russia. EM artemeva@psi.edu NR 59 TC 38 Z9 38 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 JUN PY 2005 VL 175 IS 2 BP 522 EP 533 DI 10.1016/j.icarus.2004.12.005 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 926YH UT WOS:000229159100018 ER PT J AU Lorenz, RD Kraal, ER Eddlemon, EE Cheney, J Greeley, R AF Lorenz, RD Kraal, ER Eddlemon, EE Cheney, J Greeley, R TI Sea-surface wave growth under extraterrestrial atmospheres: Preliminary wind tunnel experiments with application to Mars and Titan SO ICARUS LA English DT Article DE Mars; Titan; geological processes; meteorology; experimental techniques ID PREDICTION; OCEANS; TESTS AB We describe for the first time the generation and measurement of capillary waves in a water surface in a wind tunnel running with air at pressures of 15-1000 mbar. These experiments suggest a stronger dependence of wave generation oil atmospheric density than the simple proportionality that might be expected from energy transfer arguments. Additionally, airflow over a nonaqueous fluid (kerosene) was found to produce waves of higher amplitude than for water under the same conditions. These preliminary results may indicate different efficiencies of wave generation on other planets. for which empirical terrestrial relations therefore do not apply, and thus may have a bearing oil the lack of strong shoreline features oil Mars and the possibility of specular glints from hydrocarbon lakes on Titan. © 2004 Elsevier Inc. All rights reserved. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Lorenz, RD (reprint author), Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. EM rlorenz@lpl.arizona.edu RI Lorenz, Ralph/B-8759-2016 OI Lorenz, Ralph/0000-0001-8528-4644 NR 19 TC 24 Z9 24 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 JUN PY 2005 VL 175 IS 2 BP 556 EP 560 DI 10.1016/j.icarus.2004.11.019 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 926YH UT WOS:000229159100022 ER PT J AU Ma, ZQ Jiang, NY Wang, GG Alterovitz, SA AF Ma, ZQ Jiang, NY Wang, GG Alterovitz, SA TI An 18-GHz 300-mW SiGe power HBT SO IEEE ELECTRON DEVICE LETTERS LA English DT Article DE common-base; heterojunction bipolar transistors (HBTs); SiGe ID HETEROJUNCTION BIPOLAR-TRANSISTORS; OPTIMIZATION; TECHNOLOGY AB An 18-GHz, 300-mW SiGe power heterojunction bipolar transistor (HBT) is demonstrated. The optimization of SiGe HBT vertical profile has enabled this type of devices to operate with high gain and high power at this high frequency. In the common-base configuration, a continuous wave output power of 24.73 dBm with a power gain of 4.5 dB was measured from a single 20-emitter stripe SiGe (2 x 30 mu m(2) of each emitter finger) double HBT. The overall performance characteristics represent the state-of-the-art SiGe power HBTs operating in the K-band frequency range. C1 Univ Wisconsin, Dept Elect & Comp Engn, Madison, WI 53706 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Ma, ZQ (reprint author), Univ Wisconsin, Dept Elect & Comp Engn, Madison, WI 53706 USA. EM mazq@engr.wisc.edu NR 12 TC 16 Z9 18 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD JUN PY 2005 VL 26 IS 6 BP 381 EP 383 DI 10.1109/LED.2005.848619 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 931YS UT WOS:000229522000013 ER PT J AU Kleinsasser, AW Johnson, MW Delin, KA AF Kleinsasser, AW Johnson, MW Delin, KA TI Direct measurement of the Josephson plasma resonance frequency from I-V characteristics SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2004 Applied Superconductivity Conference CY OCT 03-08, 2004 CL Jacksonville, FL DE Josephson devices; Josephson junctions; superconducting devices; superconductor-insulator-superconductor devices ID TUNNEL-JUNCTIONS AB The speed of Josephson circuits such as those required for Rapid Single Flux Quantum logic is limited by the Josephson plasma frequency, omega(p), which (with few exceptions) increases monotonically with increasing critical current density, J(c). Here we describe a new technique for directly measuring omega(p), using the current-voltage characteristics of a simple structure based on externally-shunted, series-connected tunnel junctions. We present both experimental and theoretical demonstrations of the technique and describe its application to the determination of the junction capacitance, a property poorly characterized for high-J(c) junctions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Northrop Grumman Space Technol, Redondo Beach, CA 90278 USA. RP Kleinsasser, AW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Alan.Kleinsasser@jpi.nasa.gov; Mark.W.Johnson@ngc.com; Kevin.Delin@jpl.nasa.gov NR 6 TC 3 Z9 3 U1 2 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 2005 VL 15 IS 2 BP 86 EP 89 DI 10.1109/TASC.2005.849700 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 935FO UT WOS:000229765300004 ER PT J AU Loudkov, D Tong, CYE Blundell, R Megerian, KG Stern, JA AF Loudkov, D Tong, CYE Blundell, R Megerian, KG Stern, JA TI Performance of the NbTiN hot electron bolometer mixer with AlN buffer layer at terahertz frequency range SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2004 Applied Superconductivity Conference CY OCT 03-08, 2004 CL Jacksonville, FL DE hot electron bolometric mixer; NbTiN superconducting film; waveguide terahertz receiver ID RECEIVER AB We present recent measurements of receiver noise temperature and intermediate frequency (IF) bandwidth in the frequency range 0.8-1.3 THz for waveguide NbTiN HEB mixers of various dimensions. These devices are fabricated from an NbTiN film deposited on crystalline quartz substrates with AIN buffer layer. The lengths of the mixer elements vary from 0.3 to 0.5 mu m and their widths vary from 3 to 10 mu m. Critical temperatures are typically at 8.5 K, and the measured normal state resistance of the devices is about 1000 ohms per square. All the device DC parameters demonstrate a high degree of uniformity. A double side band noise temperature at 0.8 THz as low as 550 K has been measured at an IF frequency of 1.8 GHz, with a conversion loss of around 14 dB. At an IF of 3 GHz, the noise temperature increases to 750 K. We have also made extensive measurements of the IF bandwidth as a function of bias voltages and currents. At the optimal low-noise operation point, a 3-dB IF bandwidth of 1.2 GHz is obtained for a wide variety of device dimensions and bath temperature. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Loudkov, D (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM dloudkov@cfa.harvard.edu; etong@cfa.harvard.edu; rblundell@cfa.harvard.edu; Koko.G.Megerian@jpl.nasa.gov; Jeffrey.A.Stern@jpl.nasa.gov OI Tong, Edward/0000-0002-7736-4203 NR 10 TC 10 Z9 10 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 2005 VL 15 IS 2 BP 476 EP 479 DI 10.1109/TASC.2005.849881 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 935FO UT WOS:000229765300100 ER PT J AU Tong, CYE Blundell, R Megerian, KG Stern, JA Pan, SK Pospieszalski, M AF Tong, CYE Blundell, R Megerian, KG Stern, JA Pan, SK Pospieszalski, M TI A distributed lumped-element SIS mixer with very wide instantaneous bandwidth SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2004 Applied Superconductivity Conference CY OCT 03-08, 2004 CL Jacksonville, FL DE distributed mixing; intermediate frequency bandwidth; submillimeter waves; superconductor-insulator-superconductor mixers ID SUBMILLIMETER WAVELENGTHS; RECEIVER; DESIGN; OPERATION AB A novel type of distributed superconducting mixer with very low output capacitance has been designed for a 330-420 GHz waveguide mixer. In this design, a pair of lumped element Superconductor-Insulator-Superconductor junctions is connected in series to form the unit cell of a composite transmission line. The mixer utilizes two cascaded cells. Using an intermediate frequency (IF) of 5 GHz, we have measured Double-side-band (DSB) receiver noise temperatures of 90-120 K between 360 and 410 GHz. This mixer design offers very wide instantaneous bandwidth. The measured IF bandwidth is in excess of 18 GHz. At a Local Oscillator frequency of 384 GHz, the Y-factor measured at an IF frequency of 18 GHz is 2.1, compared to a Y-factor of 2.2 measured at an IF of 5 GHz. The mixer also has a high dynamic range. The 1-dB input compression point is only reached with an input black body load of 30,000 K. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91107 USA. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. RP Tong, CYE (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM etong@cfa.harvard.edu; rblundell@cfa.harvard.edu; Koko.G.Megerian@jpl.nasa.gov; Jeffrey.A.Stern@jpl.nasa.gov; span2@nrao.edu; mpospies@nrao.edu OI Tong, Edward/0000-0002-7736-4203 NR 14 TC 10 Z9 10 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 2005 VL 15 IS 2 BP 490 EP 494 DI 10.1109/TASC.2005.849885 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 935FO UT WOS:000229765300103 ER PT J AU Stern, JA Bumble, B Kawamura, J Skalare, A AF Stern, JA Bumble, B Kawamura, J Skalare, A TI Fabrication of terahertz frequency phonon cooled HEB mixers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2004 Applied Superconductivity Conference CY OCT 03-08, 2004 CL Jacksonville, FL DE beam-lead devices; submillimeter wave mixers; superconducting hot-electron bolometer AB We have successfully fabricated NbTiN phonon-cooled, hot-electron bolometers (HEBs) on Silicon-On-Insulator (SOI) substrates for use in terahertz-frequency waveguide mixers. At these frequencies our technology offers three significant advantages over the more common approach of using thin quartz substrates. Firstly, the SOI chips are more rugged than quartz, which become very fragile at the required thickness (< 20 microns). Secondly, the outline of the chips is defined lithographically so that they can be given a nonrectangular shape that may be required for more complicated circuits. Thirdly, freestanding gold beam-leads are used to hold the chip in place in the waveguide block and to make good electrical connections at DC, IF (intermediate frequency) and signal frequencies. The SOI wafer is a 6 pm thick Si layer bonded to a 400 mu m thick oxidized Silicon "handle" wafer. The HEBs and gold beam-leads are fabricated on front side of the SOI wafer. After processing the front side, the handle wafer is removed and the 6 mu m Si layer is patterned and etched to complete the device. Mixer measurements have been made with such devices at a signal frequency of 19 GHz, giving an IF bandwidth of about 1.4 GHz (under conditions that maximize low-frequency conversion efficiency). This bandwidth is close to that measured with similar devices on thicker silicon and on quartz. C1 Jet Propuls Lab, Pasadena, CA 91030 USA. RP Jet Propuls Lab, Pasadena, CA 91030 USA. EM Jeffrey.Stern@JPL.NASA.GOV; Bruce.Bumble@JPL.NASA.GOV; Jonathan.Kawamura@JPL.NASA.GOV; Anders.Skalare@JPL.NASA.GOV NR 10 TC 7 Z9 7 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1051-8223 EI 1558-2515 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 2005 VL 15 IS 2 BP 499 EP 502 DI 10.1109/TASC.2005.849888 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 935FO UT WOS:000229765300105 ER PT J AU Karasik, BS Sergeev, AV AF Karasik, BS Sergeev, AV TI THz hot-electron photon counter SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2004 Applied Superconductivity Conference CY OCT 03-08, 2004 CL Jacksonville, FL DE bolometers; radiation detectors; submillimeter; wave detectors; superconducting devices ID THERMAL CONDUCTANCE; DIRECT DETECTOR; QUANTUM; ASTRONOMY; RANGE; SAFIR AB We discuss an implementation of a hot-electron transition-edge sensor (TES) capable of counting THz photons. The main need for such a THz calorimeter is spectroscopy on future space telescopes with a background limited NEP similar to 10(-20) W/Hz(1/2). The micromachined bolometers will unlikely reach such sensitivity at temperatures above 10 mK. The hot-electron TES with sufficient sensitivity will still have a time constant similar to 0.1-1.0 ms that is too short for integrating a flux of THz background photons arriving at a rate of < 100 s(-1),. The Hot-Electron Photon Counter based on a submicron-size superconducting Ti bridge with Nb Andreev contacts will be able to detect individual photons above 170 GHz due to its very low heat capacity. A discrimination of the low energy fluctuations with a threshold device would allow for realization of an NEP, 10-20 W/Hz(1/2) at >= 1 THz while operating at 300 mK. With the sensor time constant of a few microseconds, the dynamic range is similar to 30-40 dB. A compact array of the antenna-coupled counters can be fabricated on a silicon wafer without membranes. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. SUNY Buffalo, Buffalo, NY 14260 USA. RP Karasik, BS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM boris.s.karasik@jpl.nasa.gov; asergeev@eng.buffalo.edu RI Karasik, Boris/C-5918-2011 NR 27 TC 24 Z9 24 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 2005 VL 15 IS 2 BP 618 EP 621 DI 10.1109/TASC.2005.849963 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 935FO UT WOS:000229765300136 ER PT J AU Shu, QSS Cheng, GFF Susta, J Li, DQ Hull, JR Demko, JA Britcher, CR Fesmire, JE Augustynowicz, SD Werfel, F Bonnema, EC AF Shu, QSS Cheng, GFF Susta, J Li, DQ Hull, JR Demko, JA Britcher, CR Fesmire, JE Augustynowicz, SD Werfel, F Bonnema, EC TI A six-meter long prototyne of the Mag-Lev cryogen transfer line SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 2004 Applied Superconductivity Conference CY OCT 03-08, 2004 CL Jacksonville, FL DE cryogenic transfer line; magnetic levitation; superconductivity; warm support AB An innovative six-meter long prototype of the magnetic levitation suspended cryogen transfer line has design, constructed and tested to demo potentials of extending many missions by saving cryogens, or reducing the overall launch mass to accomplish a given mission. The use of magnetic levitation by permanent magnets (PM) and high temperature superconductors (HTS) provides support without mechanical contact and thus, the conduction part of the heat leak can be reduced to zero, which is ultimately the most serious heat leak after thermal radiation has been minimized. The configurations of HTS & PM, the levitation force in different arrangements, the mechanical design of the transfer line, the support/release structures, and the cryogenic testing results are also discussed. C1 AMAC Int Inc, Newport News, VA 23606 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. Old Dominion Univ, Norfolk, VA 23529 USA. NASA, Kennedy Space Ctr, Cryogen Test Lab, Kennedy Space Ctr, FL 32899 USA. NASA, Kennedy Space Ctr, Sierra Lobo Inc, Kennedy Space Ctr, FL 32899 USA. ATZ GmbH, D-04886 Arzberg Adelwitz, Germany. Meyer Tool & Mfg Inc, Oak Lawn, IL 60453 USA. RP Shu, QSS (reprint author), AMAC Int Inc, Newport News, VA 23606 USA. EM qsshu@amacintl.com; jhull@anl.gov; demkoja@ornl.gov; britcher@aero.odu.edu; James.E.Fesmire@nasa.gov; Stanislaw.Augustynowicz-1@ksc.nasa.gov; Werfel@t-online.de; ecb.mtm-inc@worldnet.att.net NR 6 TC 3 Z9 4 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 2005 VL 15 IS 2 BP 2297 EP 2300 DI 10.1109/TASC.2005.849635 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 935FS UT WOS:000229765700298 ER PT J AU Barniv, Y Aguilar, M Hasanbelliu, E AF Barniv, Y Aguilar, M Hasanbelliu, E TI Using EMG to anticipate head motion for virtual-environment applications SO IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING LA English DT Article DE electromyogram; head-mounted display (HMD); neural networks; pattern recognition; virtual environment (VE) ID ELECTROMYOGRAPHY; DISPLAYS; SEQUENCE; TRACKING; MODEL; TIME AB In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms. C1 NASA, Human Informat Proc Res Branch, Moffett Field, CA 94035 USA. Rockwell Sci Co, Intelligent Syst & Planning Grp, Res Triangle Pk, NC 27510 USA. Jacksonville State Univ, MCIS Dept, Jacksonville, AL 36265 USA. RP NASA, Human Informat Proc Res Branch, Moffett Field, CA 94035 USA. EM ybarniv@mail.arc.nasa.gov; maguilar@rwsc.com; erioni@ksl.jsu.edu NR 41 TC 19 Z9 19 U1 0 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9294 EI 1558-2531 J9 IEEE T BIO-MED ENG JI IEEE Trans. Biomed. Eng. PD JUN PY 2005 VL 52 IS 6 BP 1078 EP 1093 DI 10.1109/TBME.2005.843378 PG 16 WC Engineering, Biomedical SC Engineering GA 928EP UT WOS:000229254200012 PM 15977737 ER PT J AU Simon, MK AF Simon, MK TI The true performance of the simplified data transition tracking loop SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article DE bit synchronization; tracking loops AB The tracking performance of a simplified (no transition detector in the in-phase arm and no delay in the quadrature arm) data transition tracking loop (SDTTL) suggested in the conference literature (Chin and Lee, 1987) a number of years ago for symbol synchronization of an NRZ data stream is presented. It is shown that, contrary to what was previously stated in Chin and Lee, 1987, the SDTTL and the traditional DTTL have performances that are quite different, the latter always being the more superior. In fact, asymptotically for large symbol SNR, the mean-squared timing error of the SDTTL is 3 dB worse than that of the DTTL which considerably negates its implementation simplification. Even at low SNR, where neither scheme would be motivated by maximum a posteriori (MAP) estimation of symbol sync considerations, the DTTL still outperforms the SDTTL. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Simon, MK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM marvin.k.simon@jpl.nasa.gov NR 3 TC 1 Z9 2 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD JUN PY 2005 VL 53 IS 6 BP 939 EP 944 DI 10.1109/TCOMM.2005.849994 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 938BU UT WOS:000229975700007 ER PT J AU Simon, MK Dolinar, S AF Simon, MK Dolinar, S TI Improving SNR estimation for autonomous receivers SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article DE receivers; signal-to-noise ratio (SNR) estimation; software-defined radio AB A method by which a popular signal-to-noise ratio (SNR) estimator can be reconfigured to yield improved performance is proposed. The reconfiguration consists of partitioning the symbol interval into a larger (but even) number of subdivisions than the two that have been traditionally suggested for this estimator but still processing the observables in successive pairs. The optimum number of subdivisions is shown to depend on the SNR range in which the true SNR lies; however, we also show that these SNR regions can be significantly widened with very little loss in performance. Most important is the fact that with this reconfiguration, the SNR estimator tracks the Cramer-Rao bound on the variance of the estimator over the entire range of SNR values. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Simon, MK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM marvin.k.simon@jpl.nasa.gov; sam@shannon.jpl.nasa.gov NR 13 TC 10 Z9 14 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD JUN PY 2005 VL 53 IS 6 BP 1063 EP 1073 DI 10.1109/TCOMM.2005.850002 PG 11 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 938BU UT WOS:000229975700023 ER PT J AU Zheng, Y Rivas, C Lake, R Alam, K Boykin, TB Klimeck, G AF Zheng, Y Rivas, C Lake, R Alam, K Boykin, TB Klimeck, G TI Electronic properties of silicon nanowires SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE nanowires (NWs); silicon nanowires (SiNWs) ID INDIUM-PHOSPHIDE NANOWIRES; QUANTUM WIRES; BUILDING-BLOCKS; SEMICONDUCTOR NANOWIRES; OPTICAL-PROPERTIES; POROUS SILICON; 1ST-PRINCIPLES; TRANSPORT; PHOTOLUMINESCENCE; TRANSMISSION AB The electronic structure and transmission coefficients of Si nanowires are calculated in a sp(3)d(5)s(*) model. The effect of wire thickness on the bandgap, conduction valley splitting, hole band splitting, effective masses, and transmission is demonstrated. Results from the sp(3)d(5)s(*) model are compared to those from a single-band effective mass model to assess the validity of the singleband effective mass model in narrow Si nanowires. The one-dimensional Brillouin zone of a Si nanowire is direct gap. The conduction band minimum can split into a quartet of energies although often two of the energies are degenerate. Conduction band valley splitting reduces the averaged mobility mass along the axis of the wire, but quantum confinement increases the transverse mass of the conduction band edge. Quantum confinement results in a large increase in the hole masses of the two highest valence bands. A single-band model performs reasonably well at calculating the effective band edges for wires as small as 1.54-nm square. A wire-substrate interface can be viewed as a heterojunction with band offsets resulting in reflection in the transmission. C1 Univ Calif Riverside, Dept Elect Engn, Riverside, CA 92521 USA. Univ Texas, Eric Jonson Sch Engn, Richardson, TX 75083 USA. Univ Alabama, Huntsville, AL 35899 USA. Purdue Univ, Dept Elect & Comp Engn, W Lafayette, IN 47907 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Zheng, Y (reprint author), Univ Calif Riverside, Dept Elect Engn, Riverside, CA 92521 USA. EM rlake@ee.ucr.edu RI Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 48 TC 124 Z9 126 U1 6 U2 54 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD JUN PY 2005 VL 52 IS 6 BP 1097 EP 1103 DI 10.1109/TED.2005.848077 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 929OY UT WOS:000229356700009 ER PT J AU Crow, WT Chan, STK Entekhabi, D Houser, PR Hsu, AY Jackson, TJ Njoku, EG O'Neill, PE Shi, JC Zhan, XW AF Crow, WT Chan, STK Entekhabi, D Houser, PR Hsu, AY Jackson, TJ Njoku, EG O'Neill, PE Shi, JC Zhan, XW TI An observing system simulation experiment for Hydros radiometer-only soil moisture products SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE microwave remote sensing; observing system simulation experiment; soil moisture; spaceborne radiometry ID MICROWAVE DIELECTRIC BEHAVIOR; WET SOIL; L-BAND; SURFACE; HETEROGENEITY; PARAMETERS; RETRIEVAL; MODELS; WATER; GHZ AB Based on 1-km land surface model geophysical predictions within the United States Southern Great Plains (Red-Arkansas River basin), an observing system simulation experiment (OSSE) is carried out to assess the impact of land surface heterogeneity, instrument error, and parameter uncertainty on soil moisture products derived from the National Aeronautics and Space Administration Hydrosphere State (Hydros) mission. Simulated retrieved soil moisture products are created using three distinct retrieval algorithms based on the characteristics of passive microwave measurements expected from Hydros. The accuracy of retrieval products is evaluated through comparisons with benchmark soil moisture fields obtained from direct aggregation of the original simulated soil moisture fields. The analysis provides a quantitative description of how land surface heterogeneity, instrument error, and inversion parameter uncertainty impacts propagate through the measurement and retrieval process to degrade the accuracy of Hydros soil moisture products. Results demonstrate that the discrete set of error sources captured by the OSSE induce root mean squared errors of between 2.0% and 4.5% volumetric in soil moisture retrievals within the basin. Algorithm robustness is also evaluated for the case of artificially enhanced vegetation water content (W) values within the basin. For large W(> 3 kg (.) m(-2)), a distinct positive bias, attributable to the impact of sub-footprint-scale landcover heterogeneity, is identified in soil moisture retrievals. Prospects for the removal of this bias via a correction strategy for inland water and/or the implementation of an alternative aggregation strategy for surface vegetation and roughness parameters are discussed. C1 USDA ARS, Hydrol & Remote Sensing Lab, BARC, Beltsville, MD 20705 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. MIT, Dept Civil & Environm Engn, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. RP Crow, WT (reprint author), USDA ARS, Hydrol & Remote Sensing Lab, BARC, Beltsville, MD 20705 USA. EM wcrow@hydrolab.arsusda.gov RI Zhan, Xiwu/F-5487-2010; O'Neill, Peggy/D-2904-2013; Houser, Paul/J-9515-2013 OI Houser, Paul/0000-0002-2991-0441 NR 26 TC 55 Z9 57 U1 0 U2 8 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 JUN PY 2005 VL 43 IS 6 BP 1289 EP 1303 DI 10.1109/TGRS.2005.845645 PG 15 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 932XA UT WOS:000229586900007 ER PT J AU Zavorin, I Le Moigne, J AF Zavorin, I Le Moigne, J TI Use of multiresolution wavelet feature pyramids for automatic registration of multisensor imagery SO IEEE TRANSACTIONS ON IMAGE PROCESSING LA English DT Article DE gradient-based optimization; image registration; multiresolution processing; remote-sensing imagery; wavelets ID SUBPIXEL REGISTRATION; TRANSFORMS; ALGORITHM AB The problem of image registration, or the alignment of two or more images representing the same scene or object, has to be addressed in various disciplines that employ digital imaging. In the area of remote sensing, just like in medical imaging or computer vision, it is necessary to design robust, fast, and widely applicable algorithms that would allow automatic registration of images generated by various imaging platforms at the same or different times and that would provide subpixel accuracy. One of the main issues that needs to be addressed when developing a registration algorithm is what type of information should be extracted from the images being registered, to be used in the search for the geometric transformation that best aligns them. The main objective of this paper is to evaluate several wavelet pyramids that may be used both for invariant feature extraction and for representing images at multiple spatial resolutions to accelerate registration. We find that the bandpass wavelets obtained from the steerable pyramid due to Simoncelli performs best in terms of accuracy and consistency, while the low-pass wavelets obtained from the same pyramid give the best results in terms of the radius of convergence. Based on these findings, we propose a modification of a gradient-based registration algorithm that has recently been developed for medical data. We test the modified algorithm on several sets of real and synthetic satellite imagery. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Catonsville, MD 21228 USA. NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Greenbelt, MD 20771 USA. RP Zavorin, I (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Catonsville, MD 21228 USA. EM zavorin@backserv.gsfc.nasa.gov; jacqueline.j.lemoigne-stewart@nasa.gov NR 43 TC 61 Z9 68 U1 0 U2 16 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1057-7149 J9 IEEE T IMAGE PROCESS JI IEEE Trans. Image Process. PD JUN PY 2005 VL 14 IS 6 BP 770 EP 782 DI 10.1109/TIP.2005.847287 PG 13 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 925WR UT WOS:000229084600007 PM 15971776 ER PT J AU Hornby, GS Takamura, S Yamamoto, T Fujita, M AF Hornby, GS Takamura, S Yamamoto, T Fujita, M TI Autonomous evolution of dynamic gaits with two quadruped robots SO IEEE TRANSACTIONS ON ROBOTICS LA English DT Article DE dynamic gaits; evolutionary algorithm; evolutionary robotics; genetic algorithm; legged locomotion; legged robot; quadruped robot ID DESIGN AB A challenging task that must be accomplished for every legged robot is creating the walking and running behaviors needed for it to move. In this paper we describe our system for autonomously evolving dynamic gaits on two of Sony's quadruped robots. Our evolutionary algorithm runs on board the robot and uses the robot's sensors to compute the quality of a gait without assistance from the experimenter. First, we show the evolution of a pace and trot gait on the OPEN-R prototype robot. With the fastest gait, the robot moves at over 10 m/min, which is more than forty body-lengths/min. While these first gaits are somewhat sensitive to the robot and environment in which they are evolved, we then show the evolution of robust dynamic gaits, one of which is used on the ERS-110, the first consumer version of AIBO. C1 NASA, Ames Res Ctr, QSS Grp Inc, Moffett Field, CA 94035 USA. Sony Corp, Entertainment Robot Co, Tokyo 1050004, Japan. Sony Corp, Intellignet Dynam Lab, Tokyo 1410001, Japan. RP NASA, Ames Res Ctr, QSS Grp Inc, Moffett Field, CA 94035 USA. EM hornby@email.arc.nasa.gov NR 23 TC 50 Z9 51 U1 1 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1552-3098 EI 1941-0468 J9 IEEE T ROBOT JI IEEE Trans. Robot. PD JUN PY 2005 VL 21 IS 3 BP 402 EP 410 DI 10.1109/TRO.2004.839222 PG 9 WC Robotics SC Robotics GA 933UK UT WOS:000229658200012 ER PT J AU Lamberti, N Sherrit, S Pappalardo, M Iula, A AF Lamberti, N Sherrit, S Pappalardo, M Iula, A TI Extension to the definition of quasistatic material coupling factor to include losses SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article ID IMAGINARY MATERIAL CONSTANTS; RADIAL MODE; COEFFICIENTS; REAL AB In general the coupling factor is a dimensionless coefficient, defined as a particular combination of the dielectric, elastic, and piezoelectric coefficients that may be useful for the internal energy conversion description in piezoelectric materials. In order to extend the definition of the quasistatic coupling factor as ratio of energies to dynamic conditions and to lossy materials, its current definition and its derivation are reviewed. It is shown that this parameter can be computed as ratio of energies also in dynamic conditions, and the factors obtained in the static and the dynamic case are simply related by a proportionality coefficient. The coupling factor is computed as the square root of the ratio between the converted (from mechanical to electrical or vice versa) and the total energy involved in a transformation cycle for lossy materials in quasistatic conditions, obtaining a complex quantity related to the complex material parameters taking the losses into account. In order to apply this definition to the element vibrating around its resonance frequency, the kinetic is considered as the total energy and the electrical potential as the converted energy. The obtained result is a complex quantity related to the complex material coupling factor by means of the same proportionality coefficient of the case without losses. Finally, it is shown that both the material and the dynamic coupling factors still can be considered as real parameters for real lossy materials. It also is shown that the obtained results do not depend on the wave propagation direction (longitudinal or transverse). C1 Univ Salerno, Dipartimento Ingn Informaz & Ingn, I-84084 Fisciano, SA, Italy. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. Univ Rome, Dipartimento Ingn Elettron, I-00146 Rome, Italy. RP Lamberti, N (reprint author), Univ Salerno, Dipartimento Ingn Informaz & Ingn, I-84084 Fisciano, SA, Italy. EM nlamberti@unisa.it OI Lamberti, Nicola/0000-0002-0972-7084 NR 13 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 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD JUN PY 2005 VL 52 IS 6 BP 1026 EP 1034 DI 10.1109/TUFFC.2005.1504025 PG 9 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 946AI UT WOS:000230543800010 PM 16118984 ER PT J AU Myers, JG Yerramilli, VK Hussey, SW Yee, GF Kim, J AF Myers, JG Yerramilli, VK Hussey, SW Yee, GF Kim, J TI Time and space resolved wall temperature and heat flux measurements during nucleate boiling with constant heat flux boundary conditions SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article DE boiling; microheater array; microconvection; evaporation; microlayer ID BUBBLE-GROWTH; MICROLAYER; SURFACE; EVAPORATION AB The lack of time and space resolved measurements under nucleating bubbles has complicated efforts to fully explain pool-boiling phenomena. In this work, time and space resolved temperature and heat flux distributions under nucleating bubbles on a constant heat flux surface were obtained using a 10 x 10 microheater array with 100 gm resolution along with high-speed images. A numerical simulation was used to compute the substrate conduction, which was then subtracted from the heater power to obtain the wall-to-liquid heat transfer. The data indicated that most of the energy required for bubble growth came from the superheated layer around the bubble. Microlayer evaporation and contact line heat transfer accounted for not more than 23% of the total heat transferred from the surface. The dominant heat transfer mechanism was transient conduction into the liquid during bubble departure. Bubble coalescence was not observed to transfer a significant amount of heat. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Kim, J (reprint author), Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. EM kimjh@eng.umd.edu NR 14 TC 57 Z9 58 U1 1 U2 16 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 JUN PY 2005 VL 48 IS 12 BP 2429 EP 2442 DI 10.1016/j.ijheatmasstransfer.2004.12.050 PG 14 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 929QR UT WOS:000229361300008 ER PT J AU Paylor, ED Evans, DL Tralli, DM AF Paylor, ED Evans, DL Tralli, DM TI Theme issue: Remote sensing natural hazards and geospatial information for characterization SO ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING LA English DT Editorial Material C1 Pacific Disaster Ctr Program Director, Arlington, VA 22202 USA. Earth Sci & Technol Directorate, Jet Propuls Lab, Pasadena, CA 91109 USA. Natl Space Technol Appl, Earth Sci & Technol Directorate, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Paylor, ED (reprint author), Pacific Disaster Ctr Program Director, 1235 S Clark St,Suite 601, Arlington, VA 22202 USA. EM epaylor@pdcpo.org; diane.l.evans@jpl.nasa.gov; david.m.tralli@jpl.nasa.gov NR 0 TC 4 Z9 4 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-2716 J9 ISPRS J PHOTOGRAMM JI ISPRS-J. Photogramm. Remote Sens. PD JUN PY 2005 VL 59 IS 4 BP 181 EP 184 DI 10.1016/j.isorsjprs.2005.02.005 PG 4 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 939CS UT WOS:000230050500001 ER PT J AU Tralli, DM Blom, RG Zlotnicki, V Donnellan, A Evans, DL AF Tralli, DM Blom, RG Zlotnicki, V Donnellan, A Evans, DL TI Satellite remote sensing of earthquake, volcano, flood, landslide and coastal inundation hazards SO ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 30th International Symposium on Remote Sensing of Environment CY NOV, 2003 CL Honolulu, HI DE satellite remote sensing; imaging spectroscopy; interferometric synthetic aperture radar (InSAR); global positioning system (GPS); risk mitigation; disaster response; decision support system (DSS); natural hazards ID SYNTHETIC-APERTURE RADAR; SEA-LEVEL RISE; POSITIONING SYSTEM TECHNIQUES; INTERFEROMETRIC SAR; ART.; DEFORMATION; AIRBORNE; ERUPTION; PREDICTION; INVERSION AB Satellite remote sensing is providing a systematic, synoptic framework for advancing scientific knowledge of the Earth as a complex system of geophysical phenomena that, directly and through interacting processes, often lead to natural hazards. Improved and integrated measurements along with numerical modeling are enabling a greater understanding of where and when a particular hazard event is most likely to occur and result in significant socioeconornic impact. Geospatial information products derived from this research increasingly are addressing the operational requirements of decision support systems used by policy makers, emergency managers and responders from international and federal to regional, state and local jurisdictions. This forms the basis for comprehensive risk assessments and better-informed mitigation planning, disaster assessment and response prioritization. Space-based geodetic measurements of the solid Earth with the Global Positioning System, for example, combined with ground-based seismological measurements, are yielding the principal data for modeling lithospheric processes and for accurately estimating the distribution of potentially damaging strong ground motions which is critical for earthquake engineering applications. Moreover, integrated with interterometric synthetic aperture radar, these measurements provide spatially continuous observations of deformation with sub-centimeter accuracy. Seismic and in situ monitoring, geodetic measurements, high-resolution digital elevation models (e.g. from InSAR, Lidar and digital photogrammetry) and imaging spectroscopy (e.g. using ASTER, MODIS and Hyperion) are contributing significantly to volcanic hazard risk assessment, with the potential to aid land use planning in developing countries where the impact of volcanic hazards to populations and lifelines is continually increasing. Remotely sensed data play an integral role in reconstructing the recent history of the land surface and in predicting hazards due to flood and landslide events. Satellite data are addressing diverse observational requirements that are imposed by the need for surface, subsurface and hydrologic characterization, including the delineation of flood and landslide zones for risk assessments. Short- and long-term sea-level change and the impact of ocean-atmosphere processes on the coastal land environment, through flooding, erosion and storm surge for example, define further requirements for hazard monitoring and mitigation planning. The continued development and application of a broad spectrum of satellite remote sensing systems and attendant data management infrastructure will contribute needed baseline and time series data, as part of an integrated Global observation strategy that includes airborne and in situ measurements of the solid Earth. Multi-hazard modeling capabilities, in turn, will result in more accurate forecasting and visualizations for improving the decision support tools and systems used by the international disaster management community. (c) 2005 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). Published by Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Earth Sci & Techol Directorate, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, Earth Sci & Techol Directorate, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM david.m.tralli@jpl.nasa.gov NR 52 TC 145 Z9 154 U1 30 U2 232 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-2716 EI 1872-8235 J9 ISPRS J PHOTOGRAMM JI ISPRS-J. Photogramm. Remote Sens. PD JUN PY 2005 VL 59 IS 4 BP 185 EP 198 DI 10.1016/j.isprsjprs.2005.02.002 PG 14 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 939CS UT WOS:000230050500002 ER PT J AU Atlas, R Hou, AY Reale, O AF Atlas, R Hou, AY Reale, O TI Application of SeaWinds scatterometer and TMI-SSM/I rain rates to hurricane analysis and forecasting SO ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 30th International Symposium on Remote Sensing of Environment CY NOV, 2003 CL Honolulu, HI DE scatterometer; TMI-SSM/I; hurricane prediction; microwave remote sensing applications ID ASSIMILATION; WINDS; WATER AB Results provided by two different assimilation methodologies involving data from passive and active space-borne microwave instruments are presented. The impact of the precipitation estimates produced by the TRMM Microwave Imager (TMI) and Special Sensor Microwave/Imager (SSM/I) in a previously developed ID variational continuous assimilation algorithm for assimilating tropical rainfall is shown on two hurricane cases. Results on the impact of the SeaWinds scatterometer on the intensity and track forecast of a mid-Atlantic hurricane are also presented. This work is the outcome of a collaborative effort between NASA and NOAA and indicates the substantial improvement in tropical cyclone forecasting that can result from the assimilation of space-based data in global atmospheric models. (c) 2005 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). Published by Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Univ Maryland, Baltimore, MD 21201 USA. RP Atlas, R (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 661, Greenbelt, MD 20771 USA. EM Robert.M.Atlas@nasa.gov RI Atlas, Robert/A-5963-2011; Hou, Arthur/D-8578-2012 OI Atlas, Robert/0000-0002-0706-3560; NR 14 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-2716 J9 ISPRS J PHOTOGRAMM JI ISPRS-J. Photogramm. Remote Sens. PD JUN PY 2005 VL 59 IS 4 BP 233 EP 243 DI 10.1016/j.isprsjprs.2005.02.007 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 939CS UT WOS:000230050500006 ER PT J AU Evans, KF Wang, JR Racette, PE Heymsfield, G Li, LH AF Evans, KF Wang, JR Racette, PE Heymsfield, G Li, LH TI Ice cloud retrievals and analysis with the compact scanning submillimeter Imaging radiometer and the cloud radar system during CRYSTAL FACE SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MICROWAVE RADIATIVE-TRANSFER; CIRRUS CLOUDS; WATER-VAPOR; PRECIPITATION; CHANNELS; MISSION; MIR AB Submillimeter-wave radiometry is a new technique for determining ice water path (IWP) and particle size in upper-tropospheric ice clouds. The first brightness temperatures images of ice clouds above 340 GHz were measured by the Compact Scanning Submillimeter Imaging Radiometer (CoSSIR) during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers (CRYSTAL) Florida Area Cirrus Experiment (FACE) campaign in July 2002. CoSSIR operated with 12 channels from receivers at 183, 220, 380, 487, and 640 GHz. CoSSIR and the nadir-viewing 94-GHz Cloud Radar System (CRS) flew on the NASA ER-2 airplane based out of Key West, Florida. A qualitative comparison of the CoSSIR brightness temperatures demonstrates that the submillimeter-wave frequencies are more sensitive to anvil ice cloud particles than are the lower frequencies. A Bayesian algorithm, with a priori microphysical information from in situ cloud probes, is used to retrieve the IWP and median mass equivalent sphere particle diameter (D-me. Microwave scattering properties of random aggregates of plates and aggregates of frozen droplets are computed with the discrete dipole approximation (DDA) and an effective medium approximation tuned to DDA results. As a test of the retrievals, the vertically integrated 94-GHz radar backscattering is also retrieved from the CoSSIR data and compared with that measured by the CRS. The integrated backscattering typically agrees within 1-2 dB for IWP from 1000 to 10 000 g m(-2), and while the disagreement increases for smaller IWP, it is typically within the Bayesian error bars. Retrievals made with only the three 183- and one 220-GHz channel are generally as good or better than those including 380 +/- 6.2 and 640 GHz, because the CoSSIR submillimeter-wave channels were much noisier than expected. An algorithm to retrieve profiles of ice water content and D. from CRS and CoSSIR data was developed. This Bayesian algorithm also retrieves the coefficients of an IWC-radar reflectivity power-law relation and could be used to evaluate radar-only ice cloud retrieval algorithms. C1 Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA. RP Evans, KF (reprint author), Univ Colorado, Program Atmospher & Ocean Sci, 311 UCB, Boulder, CO 80309 USA. EM evans@nit.colorado.edu NR 23 TC 46 Z9 46 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JUN PY 2005 VL 44 IS 6 BP 839 EP 859 DI 10.1175/JAM2250.1 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 950XO UT WOS:000230892200007 ER PT J AU Naud, CM Muller, JP Slack, EC Wrench, CL Clothiaux, EE AF Naud, CM Muller, JP Slack, EC Wrench, CL Clothiaux, EE TI Assessment of the performance of the Chilbolton 3-GHz advanced meteorological radar for cloud-top-height retrieval SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MISR; SCATTERING; CUMULUS; ECHOES AB The Chilbolton 3-GHz Advanced Meteorological Radar (CAMRa), which is mounted on a fully steerable 25-m dish, can provide three-dimensional information on the presence of hydrometeors. The potential for this radar to make useful measurements of low-altitude liquid water cloud structure is investigated. To assess the cloud-height assignment capabilities of the 3-GHz radar, low-level cloud-top heights were retrieved from CAMRa measurements made between May and July 2003 and were compared with cloud-top heights retrieved from a vertically pointing 94-GHz radar that operates alongside CAMRa. The average difference between the 94- and 3-GHz radar-derived cloud-top heights is shown to be -0.1 +/- 0.4 km. To assess the capability of 3-GHz radar scans to be used for satellite-derived cloud-top-height validation, multiangle imaging spectroradiometer (MISR) cloud-top heights were compared with both 94- and 3-GHz radar retrievals. The average difference between 94-GHz radar and MISR cloud-top heights is shown to be 0.1 +/- 0.3 km, while the 3-GHz radar and MISR average cloud-top-height difference is shown to be -0.2 +/- 0.6 km. In assessing the value of the CAMRa measurements, the problems associated with low-reflectivity values from stratiform liquid water clouds, ground clutter, and Bragg scattering resulting from turbulent mixing are all addressed. It is shown that, despite the difficulties, the potential exists for CAMRa measurements to contribute significantly to liquid water cloud-top-h eight retrievals, leading to the production of two-dimensional transects (i.e., maps) of cloud-top height. C1 UCL, London, England. CCLRC, Rutherford Appleton Lab, Didcot, Oxon, England. Penn State Univ, University Pk, PA 16802 USA. RP Naud, CM (reprint author), NASA, Goddard Inst Space Studies, Room 678,2880 Broadway, New York, NY 10025 USA. EM cnaud@giss.nasa.gov NR 17 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JUN PY 2005 VL 44 IS 6 BP 876 EP 887 DI 10.1175/JAM2244.1 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 950XO UT WOS:000230892200009 ER PT J AU Santanello, JA Friedl, MA Kustas, WP AF Santanello, JA Friedl, MA Kustas, WP TI An empirical investigation of convective planetary boundary layer evolution and its relationship with the land surface SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MIXED-LAYER; SKIN TEMPERATURES; SOIL-MOISTURE; HEAT-FLUX; RADIOSONDE; GROWTH; BUDGET; ENTRAINMENT; ATMOSPHERE; ROUGHNESS AB Relationships among convective planetary boundary layer (PBL) evolution and land surface properties are explored using data from the Atmospheric Radiation Measurement Program Cloud and Radiation Test Bed in the southern Great Plains. Previous attempts to infer surface fluxes from observations of the PBL have been constrained by difficulties in accurately estimating and parameterizing the conservation equation and have been limited to multiday averages or small samples of daily case studies. Using radiosonde and surface flux data for June, July, and August of 1997, 1999, and 2001, a conservation approach was applied to 132 sets of daily observations. Results highlight the limitations of using this method on daily time scales caused by the diurnal variability and complexity of entrainment. A statistical investigation of the relationship among PBL and both land surface and near-surface properties that are not explicitly included in conservation methods indicates that atmospheric stability in the layer of PBL growth is the most influential variable controlling PBL development. Significant relationships between PBL height and soil moisture, 2-m potential temperature, and 2-m specific humidity are also identified through this analysis, and it is found that 76% of the variance in PBL height can be explained by observations of stability and soil water content. Using this approach, it is also possible to use limited observations of the PBL to estimate soil moisture on daily time scales without the need for detailed land surface parameterizations. In the future, the general framework that is presented may provide a means for robust estimation of near-surface soil moisture and land surface energy balance over regional scales. C1 Boston Univ, Dept Geog, Boston, MA 02215 USA. USDA, Hydrol & Remote Sensing Lab, Beltsville, MD USA. RP Santanello, JA (reprint author), NASA, GSFC, Earth Syst Sci Interdisciplinary Ctr, Hydrospher & Biospher Sci Lab, Code 6143, Greenbelt, MD 20771 USA. EM sntnello@hsb.gsfc.nasa.gov RI Santanello, Joseph/D-4438-2012 OI Santanello, Joseph/0000-0002-0807-6590 NR 34 TC 36 Z9 36 U1 1 U2 13 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JUN PY 2005 VL 44 IS 6 BP 917 EP 932 DI 10.1175/JAM2240.1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 950XO UT WOS:000230892200012 ER PT J AU Boykin, TB Klimeck, G von Allmen, P Lee, S Oyafuso, F AF Boykin, TB Klimeck, G von Allmen, P Lee, S Oyafuso, F TI Valley splitting in V-shaped quantum wells SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INVERSION-LAYERS; MAGNETIC-FIELD; HETEROSTRUCTURES; SURFACES AB The valley splitting (energy difference between the states of the lowest doublet) in strained silicon quantum wells with a V-shaped potential is calculated variationally using a two-band tight-binding model. The approximation is valid for a moderately long (approximately 5.5-13.5 nm) quantum well with a V-shaped potential which can be produced by a realistic delta-doping on the order of n(d)approximate to 10(12) cm(-2). The splitting versus applied field (steepness of the V-shaped potential) curves show interesting behavior: a single minimum and for some doublets, a parity reversal as the field is increased. These characteristics are explained through an analysis of the variational wave function and energy functional. (C) 2005 American Institute of Physics. C1 Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Boykin, TB (reprint author), Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. EM boykin@eng.uah.edu RI Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 20 TC 10 Z9 10 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 2005 VL 97 IS 11 AR 113702 DI 10.1063/1.1913798 PG 6 WC Physics, Applied SC Physics GA 935SW UT WOS:000229804700058 ER PT J AU Jackson, BD de Lange, G Zijlstra, T Kroug, M Klapwijk, TM Stern, JA AF Jackson, BD de Lange, G Zijlstra, T Kroug, M Klapwijk, TM Stern, JA TI Niobium titanium nitride-based superconductor-insulator-superconductor mixers for low-noise terahertz receivers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID AMBIENT SUBSTRATE-TEMPERATURE; THIN-FILMS; TUNNEL-JUNCTIONS; TUNING CIRCUIT; GAP FREQUENCY; SIS MIXERS; STRIPLINES; GHZ AB Integrating NbTiN-based microstrip tuning circuits with traditional Nb superconductor-insulator-superconductor (SIS) junctions enables the low-noise operation regime of SIS mixers to be extended from below 0.7 to 1.15 THz. In particular, mixers incorporating a NbTiN/SiO2/NbTiN microstrip tuning circuit offer low-noise performance below 0.8-0.85 THz, although their sensitivities drop significantly at higher frequencies. Furthermore, a microstrip geometry in which NbTiN is used as the ground plane material only (NbTiN/SiO2/Al) yields significant improvements in the sensitivities of SIS mixers operating up to 1.15 THz, with an upper operating frequency that depends upon the quality of the NbTiN layer, and thus its deposition process. Films deposited at room temperature have T-c=14.4 K and rho(n,20 K)similar to 60 mu Omega cm, and offer low-noise performance up to 1 THz, whereas films deposited at 400 degrees C have T-c=16 K and rho(n,20 K)similar to 110 mu Omega cm, and offer low-noise performance up to 1.15 THz. Taken together, these results demonstrate that the high-frequency surface resistance of a NbTiN layer depends upon the film's structural properties. Most significantly, the drop in performance that is seen at F>1 THz in mixers incorporating NbTiN ground planes deposited at room temperature is attributed to nonhomogeneities in the structural and electrical properties of these films, as is the poor performance of mixers that incorporate NbTiN wiring layers at F>0.85 THz. The development of these NbTiN-based microstrip tuning circuits will enable the production of low-noise SIS mixers for the 0.8-0.96- and 0.96-1.12-THz frequency bands of the Heterodyne Instrument for the Far Infrared on board the European Space Agency's Herschel Space Observatory. (C) 2005 American Institute of Physics. C1 Delft Univ Technol, Fac Sci Appl, Kavli Inst Nanosci, NL-2628 CJ Delft, Netherlands. SRON, Netherlands Inst Space Res, NL-9747 AD Groningen, Netherlands. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jackson, BD (reprint author), Delft Univ Technol, Fac Sci Appl, Kavli Inst Nanosci, Lorentzweg 1, NL-2628 CJ Delft, Netherlands. EM b.d.jackson@sron.rug.nl NR 28 TC 13 Z9 13 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 2005 VL 97 IS 11 AR 113904 DI 10.1063/1.1927281 PG 8 WC Physics, Applied SC Physics GA 935SW UT WOS:000229804700075 ER PT J AU Samadi, R Goupil, MJ Alecian, E Baudin, F Georgobiani, D Trampedach, R Stein, R Nordlund, A AF Samadi, R Goupil, MJ Alecian, E Baudin, F Georgobiani, D Trampedach, R Stein, R Nordlund, A TI Excitation of solar-like oscillations: From PMS to MS stellar models SO JOURNAL OF ASTROPHYSICS AND ASTRONOMY LA English DT Article; Proceedings Paper CT Aries International Workshop on Asteroseismology CY DEC 06-08, 2004 CL Uttaranchal Acad Adm, Manora Peak, INDIA SP Aryabhatta Res Inst Observat Sci HO Uttaranchal Acad Adm DE turbulence; convection; oscillations; excitation; sun, stars :alpha Cen A; stars : main and pre-main sequence stars ID MAIN-SEQUENCE STARS; ALPHA-CENTAURI-A; P-MODES; TURBULENT CONVECTION; STOCHASTIC EXCITATION; HELIOSEISMOLOGICAL DATA; PULSATIONAL STABILITY; RADIAL OSCILLATIONS; DELTA-SCUTI; SEISMOLOGY AB The amplitude of solar-like oscillations results from a balance between excitation and damping. As in the sun, the excitation is, attributed to turbulent, motions that stochastically excite the p modes in the uppermost part of the convective zone. We present here a model for the excitation mechanism. Comparisons between modeled amplitudes and helio and stellar seismic constraints are presented and the discrepancies discussed. Finally the possibility and the interest of detecting such stochastically excited modes in pre-main sequence stars are also discussed. C1 Observ Paris, F-92195 Meudon, France. Inst Astrophys Spatiale, Orsay, France. Stanford Univ, Ctr Turbulence Res, NASA, Ames Res Ctr, Moffett Field, CA USA. Mt Stromlo & Siding Spring Observ, Res Sch Astron & Astrophys, Weston, ACT, Australia. Michigan State Univ, E Lansing, MI 48824 USA. Niels Bohr Inst, DK-2100 Copenhagen, Denmark. RP Samadi, R (reprint author), Observ Paris, 5 Pl J Janssen, F-92195 Meudon, France. RI Nordlund, Aake/M-4528-2014 OI Nordlund, Aake/0000-0002-2219-0541 NR 39 TC 32 Z9 32 U1 0 U2 3 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA SN 0250-6335 J9 J ASTROPHYS ASTRON JI J. Astrophys. Astron. PD JUN-SEP PY 2005 VL 26 IS 2-3 BP 171 EP 184 DI 10.1007/BF02702325 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 965YX UT WOS:000231987900006 ER PT J AU Cahalan, RF McGill, M Kolasinski, J Varnai, T Yetzer, K AF Cahalan, RF McGill, M Kolasinski, J Varnai, T Yetzer, K TI THOR - Cloud Thickness from Offbeam lidar Returns SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID LIQUID WATER-CONTENT; ANGLE IMAGING LIDAR; OFF-BEAM LIDAR; STRATOCUMULUS CLOUDS; MARINE STRATOCUMULUS; VERTICAL STRUCTURE; INDEPENDENT PIXEL; SEA-ICE; SCATTERING; ALBEDO AB Conventional wisdom is that lidar pulses do not significantly penetrate clouds having an optical thickness exceeding about tau = 2, and that no returns are detectible from more than a shallow skin depth. Yet optically thicker clouds Of tau >> 2 reflect a larger fraction of visible photons and account for much of the earth's global average albedo. As cloud-layer thickness grows, an increasing fraction of reflected photons are scattered multiple times within the cloud and return from a diffuse concentric halo that grows around the incident pulse, increasing in horizontal area with layer physical thickness. The reflected halo is largely undetected by narrow field-of-view (FOV) receivers commonly used in lidar applications. Cloud Thickness from Offbeam Returns (THOR) is an airborne wide-angle detection system with multiple FOVs, capable of observing the diffuse halo as a wide-angle signal, from which the physical thickness of optically thick clouds can be retrieved. This paper describes the THOR system, demonstrates that the halo signal is stronger for thicker clouds, and presents a validation of physical thickness retrievals for clouds having tau > 20, from NASA's P-3B flights over the Department of Energy's Atmospheric Radiation Measurement Southern Great Plains site, using the lidar, radar, and other ancillary ground-based data. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland, Joint Ctr Earth Syst Technol, Baltimore, MD 21201 USA. SSAI, Raytheon, Lanham, MD USA. RP Cahalan, RF (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. EM Robert.F.Cahalan@nasa.gov RI McGill, Matthew/D-8176-2012; Cahalan, Robert/E-3462-2012 OI Cahalan, Robert/0000-0001-9724-1270 NR 39 TC 24 Z9 26 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 JUN PY 2005 VL 22 IS 6 BP 605 EP 627 DI 10.1175/JTECH1740.1 PG 23 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 940JK UT WOS:000230140600001 ER PT J AU Hooker, SB Zibordi, G AF Hooker, SB Zibordi, G TI Advanced methods for characterizing the immersion factor of irradiance sensors SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID QUALITY MONITOR SQM; FIELD RADIOMETERS; CALIBRATION; LIGHT AB Two new immersion factor methods are evaluated by comparing them with the so-called traditional (or incremental) method. For the first method, the optical measurements taken at discrete water depths are substituted by continuous profiles created by removing the water from the tank used in the experimental procedure at a constant flow rate with a pump. In the second method, the commonly used large tank is replaced by a small water vessel with sidewall baffles, which permits the use of a quality-assured volume of water. The summary of the validation results produced for the different methods shows a significant convergence of the two new methods with the traditional method with differences generally well below 1%. The average repeatabilities for single-sensor characterizations (across seven wavelengths) of the three methods are very similar and approximately 0.5%. The evaluation of the continuous method demonstrates its full applicability in the determination of immersion factors with a significant time savings. The results obtained with the small water vessel demonstrate the possibility of significantly reducing the size of the tank (along with decreasing the execution time) and permitting a completely reproducible methodology (based on the use of pure water). The small tank approach readily permits the isolation and quantification of individual sources of uncertainty, the results of which confirm the following aspects of the general experimental methodology: (a) pure water is preferred over tap water, (b) the water should not be recycled (so it does not age), (c) bubbles should be removed from all wetted surfaces, (d) the water surface should be kept as clean as possible, (e) sidewall reflections can be properly minimized with internal baffles, and (f) a pure water characterization can be easily corrected to produce an appropriate seawater characterization. Within the context of experimental efficiency and reproducibility, this study suggests that the combination of a properly baffled small tank with a constant-flow pump would be an optimal system. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. Joint Res Ctr, Inst Environm Sustainabil, Ispra, Italy. RP Hooker, SB (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. EM stan@ardbeg.gsfc.nasa.gov RI Hooker, Stanford/E-2162-2012 NR 23 TC 9 Z9 9 U1 1 U2 2 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 JUN PY 2005 VL 22 IS 6 BP 757 EP 770 DI 10.1175/JTECH1736.1 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 940JK UT WOS:000230140600012 ER PT J AU Dodhia, RM AF Dodhia, RM TI Applied multiple regression/correlation analysis for the behavioral sciences SO JOURNAL OF EDUCATIONAL AND BEHAVIORAL STATISTICS LA English DT Book Review C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. San Jose State Univ, San Jose, CA 95192 USA. RP Dodhia, RM (reprint author), eBay Inc, San Jose, CA USA. EM rahul.dodhia@gmail.com NR 5 TC 2 Z9 3 U1 3 U2 25 PU AMER EDUCATIONAL RESEARCH ASSOC PI WASHINGTON PA 1230 17TH ST NW, WASHINGTON, DC 20036-3078 USA SN 1076-9986 J9 J EDUC BEHAV STAT JI J. Educ. Behav. Stat. PD SUM PY 2005 VL 30 IS 2 BP 227 EP 229 DI 10.3102/10769986030002227 PG 3 WC Education & Educational Research; Social Sciences, Mathematical Methods; Psychology, Mathematical SC Education & Educational Research; Mathematical Methods In Social Sciences; Psychology GA 934CU UT WOS:000229685300006 ER PT J AU Harris, W Roesler, F Ben-Jaffel, L Mierkiewicz, E Corliss, J Oliversen, R Neef, T AF Harris, W Roesler, F Ben-Jaffel, L Mierkiewicz, E Corliss, J Oliversen, R Neef, T TI Applications of spatial heterodyne spectroscopy for remote sensing of diffuse UV-vis emission line sources in the solar system SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 14th International Conference on Vacuum Ultraviolet Radiation Physics CY JUL 19-23, 2004 CL Cairns, AUSTRALIA DE interferometery; spectroscopy ID ULTRAVIOLET SPECTROMETER EXPERIMENT; ATMOSPHERE; MISSION AB Spatial heterodyne spectrographs combine high spectral resolution with large etendue in a compact instrument. This combination makes them useful for studies of extended diffuse sources requiring velocity resolution or the separation of closely packed emission lines, while their small size makes them suitable for platforms ranging from ground-based observatories to satellites. Improvements in optical element and detector capabilities have expanded opportunities for SHS in the VUV, where its combination of size, resolution, and etendue have not been available. Here we discuss the basics of the SHS technique and how an instrument may be designed to study various emission line sources in the solar system. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Inst Astrophys Paris, CNRS, Paris, France. NASA, GSFC, Greenbelt, MD USA. RP Harris, W (reprint author), Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. EM wmharris@u.washington.edu RI Mierkiewicz, Edwin/N-7926-2016 OI Mierkiewicz, Edwin/0000-0002-4283-3751 NR 12 TC 11 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 2005 VL 144 SI SI BP 973 EP 977 DI 10.1016/j.elspec.2005.01.223 PG 5 WC Spectroscopy SC Spectroscopy GA 933TZ UT WOS:000229657100229 ER PT J AU Humphreys, RL Campana, SE DeMartini, EE AF Humphreys, RL Campana, SE DeMartini, EE TI Otolith elemental fingerprints of juvenile Pacific swordfish Xiphias gladius SO JOURNAL OF FISH BIOLOGY LA English DT Article DE central Pacific; isotope dilution ICP-MS; juvenile otoliths; otolith chemistry; swordfish nursery areas; Xiphias gladius ID MITOCHONDRIAL-DNA; FISH OTOLITHS; STOCK IDENTIFICATION; POPULATION-STRUCTURE; CONTROL REGION; BLUEFIN TUNA; MICROSTRUCTURE; VARIABILITY; CHEMISTRY; GROWTH AB The trace element composition of young-of-the-year (YOY) juvenile swordfish Xiphias gladius sagittal otoliths were analysed as a preliminary test of the value of otolith elemental fingerprints for determining swordfish nursery ground origins in the central Pacific Ocean. A suite of five elements (Mg. Zn, Sr, Ba and Ph) was assayed with isotope dilution ICP-MS all elemental concentrations were roughly comparable to otoliths of other marine fishes. Multivariate analyses of elemental fingerprints based on Ba and Sr revealed differences between sample sites, and the magnitude of the differences increased with latitudinal separation. With more comprehensive sampling of nursery grounds, it should be possible to identify origin of nursery ground for adult swordfish by analysing the YOY juvenile portion of the sagittal otolith. (c) 2005 The Fisheries Society of the British Isles C1 Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA. Bedford Inst Oceanog, Marine Fish Div, Dartmouth, NS B2Y 4A2, Canada. RP Humphreys, RL (reprint author), Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, 2570 Dole St, Honolulu, HI 96822 USA. EM robert.humphreys@noaa.gov RI Campana, Steven/C-3420-2013 OI Campana, Steven/0000-0001-8802-3976 NR 25 TC 10 Z9 11 U1 1 U2 8 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD JUN PY 2005 VL 66 IS 6 BP 1660 EP 1670 DI 10.1111/j.0022-1112.2005.00712.x PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 940CL UT WOS:000230121200012 ER PT J AU Chin, TM Gross, RS Dickey, JO AF Chin, TM Gross, RS Dickey, JO TI Multi-reference evaluation of uncertainty in earth orientation parameter measurements SO JOURNAL OF GEODESY LA English DT Article DE earth rotation; measurement error; combination ID ANGULAR-MOMENTUM; TIME-SERIES; COMBINATIONS; ROTATION; SPLINE; LENGTH AB Uncertainties in polar motion and length-of-day measurements are evaluated empirically using several data series from the space-geodetic techniques of the global positioning system (GPS), satellite laser ranging (SLR), and very long baseline interferometry (VLBI) during 1997-2002. In the evaluation procedure employed here, known as the three-corner hat (TCH) technique, the signal common to each series is eliminated by forming pair-wise differences between the series, thus requiring no assumed values for the "truth" signal. From the variances of the differenced series, the uncertainty of each series can be recovered when reasonable assumptions are made about the correlations between the series. In order to form the pair-wise differences, the series data must be given at the same epoch. All measurement data sets studied here were sampled at noon (UTC); except for the VLBI series, whose data are interpolated to noon and whose UT1 values are also numerically differentiated to obtain LOD. The numerical error introduced to the VLBI values by the interpolation and differentiation is shown to be comparable in magnitude to the values determined by the TCH method for the uncertainties of the VLBI series. The TCH estimates for the VLBI series are corrupted by such numerical errors mostly as a result of the relatively large data intervals. Of the remaining data sets studied here, it is found that the IGS Final combined series has the smallest polar motion and length-of-day uncertainties. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chin, TM (reprint author), CALTECH, Jet Prop Lab, Mailstop 238-332,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mike.chin@jpl.nasa.gov NR 15 TC 5 Z9 5 U1 0 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0949-7714 J9 J GEODESY JI J. Geodesy PD JUN PY 2005 VL 79 IS 1-3 BP 24 EP 32 DI 10.1007/s00190-005-0439-0 PG 9 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 935SB UT WOS:000229802600003 ER PT J AU Ding, XL Zheng, DW Dong, DN Ma, C Chen, YQ Wang, GL AF Ding, XL Zheng, DW Dong, DN Ma, C Chen, YQ Wang, GL TI Seasonal and secular positional variations at eight co-located GPS and VLBI stations SO JOURNAL OF GEODESY LA English DT Article DE GPS; VLBI; station solution; seasonal signals; inter-annual variations ID DEFORMATION; CAMPAIGNS; MOTIONS; SERIES; SCALE; SPACE AB Time series of daily position solutions at eight co-located GPS and VLBI stations are used to assess the frequency features in the solutions over various time-scales. This study shows that there are seasonal and inter-annual signals in all three coordinate components of the GPS and VLBI solutions. The power and frequency of the signals vary with time, the station considered and the coordinate components, and between the GPS and VLBI solutions. In general, the magnitudes of the signals in the horizontal coordinate components (latitude and longitude) are weaker than those in the height component. The weighted means of the estimated annual amplitudes from the eight GPS stations are, respectively, 1.0, 0.8 and 3.6 mm for the latitude, longitude and height components, and are, respectively, 1.5, 0.7 and 2.2 mm for the VLBI solutions. The phases of the annual signals estimated from the GPS and VLBI solutions are consistent for most of the co-located stations. The seasonal signals estimated from the VLBI solutions are, in general, more stable than those estimated from the GPS solutions. Fluctuations at inter-annual time-scales are also found in the series. The inter-annual fluctuations are up to similar to 5 mm for the latitude and longitude components, and up to similar to 10 mm for the height component. The effects of the seasonal and inter-annual variations on the estimated linear rates of movement of the stations are also evaluated. C1 Hong Kong Polytech Univ, Dept Land Surveying & Geoinformat, Hong Kong, Hong Kong, Peoples R China. Chinese Acad Sci, Shanghai Astron Observ, Ctr Astrogeodynam Res, Shanghai 200030, Peoples R China. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. RP Ding, XL (reprint author), Hong Kong Polytech Univ, Dept Land Surveying & Geoinformat, Hong Kong, Hong Kong, Peoples R China. EM lsxlding@polyu.edu.hk RI Ma, Chopo/D-4751-2012; Ding, Xiaoli/K-4596-2013 OI Ding, Xiaoli/0000-0002-5733-3629 NR 23 TC 15 Z9 16 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0949-7714 J9 J GEODESY JI J. Geodesy PD JUN PY 2005 VL 79 IS 1-3 BP 71 EP 81 DI 10.1007/s00190-005-0444-3 PG 11 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 935SB UT WOS:000229802600008 ER PT J AU Aires, F Prigent, C Rossow, WB AF Aires, F Prigent, C Rossow, WB TI Sensitivity of satellite microwave and infrared observations to soil moisture at a global scale: 2. Global statistical relationships SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LAND-SURFACE EMISSIVITIES; TEMPERATURE; MODEL; WATER; REANALYSIS; INTERPOLATION; ASSIMILATION; HYDROLOGY; ERA-40; CYCLE AB [1] In part 1 of this study (Prigent et al., 2004), in situ measurements were used to analyze and describe the sensitivities of satellite measurements (i.e., active and passive microwave observations and surface skin temperature diurnal cycle amplitude) to the soil moisture variations to describe the complex relationships that exist between them. Soil moisture was considered in the first 10-cm layer on a 0.25 degrees equal-area grid and a monthly timescale. In this study, the lessons from the first paper are exploited to document the sensitivity of the satellite data to the global large-scale variations of soil moisture. A statistical model based on neural networks is developed to link the satellite observations and soil moisture estimates. Given the lack of available in situ soil moisture measurements on a global basis, National Centers for Environmental Prediction (NCEP) and European Centre for Medium-Range Weather Forecasts (ECMWF) soil moisture reanalyses are used as a realistic global indicator of soil moisture. As a consequence, the statistical model cannot be considered as a retrieval scheme per se, but it shows the feasibility of such an approach. It also quantifies the information content that can be expected from the satellite observations. Applications of such a statistical model include checking the consistency of surface model, and as the basis for variational assimilation of satellite observations into a numerical surface model. C1 Univ Paris 06, CNRS, IPSL, Meteorol Dynam Lab, F-75252 Paris, France. Observ Paris, LERMA, CNRS, F-75014 Paris, France. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Aires, F (reprint author), Univ Paris 06, CNRS, IPSL, Meteorol Dynam Lab, Case 99,4 Pl Jussieu, F-75252 Paris, France. EM filipe.aires@lmd.jussieu.fr; catherine.prigent@obspm.fr; wrossow@giss.nasa.gov RI Rossow, William/F-3138-2015 NR 30 TC 19 Z9 20 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 JUN 1 PY 2005 VL 110 IS D11 AR D11103 DI 10.1029/2004JD005094 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 936BW UT WOS:000229829100002 ER PT J AU Park, RJ Jacob, DJ Palmer, PI Clarke, AD Weber, RJ Zondlo, MA Eisele, FL Bandy, AR Thornton, DC Sachse, GW Bond, TC AF Park, RJ Jacob, DJ Palmer, PI Clarke, AD Weber, RJ Zondlo, MA Eisele, FL Bandy, AR Thornton, DC Sachse, GW Bond, TC TI Export efficiency of black carbon aerosol in continental outflow: Global implications SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PACIFIC TRACE-P; CHEMICAL EVOLUTION; ATMOSPHERIC AEROSOLS; TRANSPORT PATHWAYS; RADIATIVE-TRANSFER; WESTERN PACIFIC; UNITED-STATES; MODEL; SOOT; ASIA AB [1] We use aircraft observations of Asian outflow from the NASA Transport and Chemical Evolution over the Pacific ( TRACE-P) mission over the NW Pacific in March - April 2001 to estimate the export efficiency of black carbon ( BC) aerosol during lifting to the free troposphere, as limited by scavenging from the wet processes ( warm conveyor belts and convection) associated with this lifting. Our estimate is based on the enhancement ratio of BC relative to CO in Asian outflow observed at different altitudes and is normalized to the enhancement ratio observed in boundary layer outflow ( 0 - 1 km). We similarly estimate export efficiencies of sulfur oxides (SOx = SO2( g) + fine SO42-) and total inorganic nitrate (HNO3T = HNO3( g) + fine NO3-) for comparison to BC. Normalized export efficiencies for BC are 0.63 - 0.74 at 2 - 4 km altitude and 0.27 - 0.38 at 4 - 6 km. Values at 2 - 4 km altitude are higher than for SOx (0.48 - 0.66) and HNO3T (0.29 - 0.62), implying that BC is scavenged in wet updrafts but not as efficiently as sulfate or nitrate. Simulation of the TRACE-P period with a global three-dimensional model (GEOS-CHEM) indicates that a model timescale of 1 +/- 1 days for conversion of fresh hydrophobic to hydrophilic BC provides a successful fit to the export efficiencies observed in TRACE-P. The resulting mean atmospheric lifetime of BC is 5.8 +/- 1.8 days, the global burden is 0.11 +/- 0.03 Tg C, and the decrease in Arctic snow albedo due to BC deposition is 3.1 +/- 2.5%. C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Illinois, Dept Civil & Environm Engn, Urbana, IL 61801 USA. RP Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. EM rpark@fas.harvard.edu RI Palmer, Paul/F-7008-2010; Bond, Tami/A-1317-2013; Chem, GEOS/C-5595-2014; Park, Rokjin/I-5055-2012; Zondlo, Mark/R-6173-2016 OI Bond, Tami/0000-0001-5968-8928; Park, Rokjin/0000-0001-8922-0234; Zondlo, Mark/0000-0003-2302-9554 NR 57 TC 99 Z9 100 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 JUN 1 PY 2005 VL 110 IS D11 AR D11205 DI 10.1029/2004JD005432 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 936BW UT WOS:000229829100006 ER PT J AU Pincus, R Hannay, C Klein, SA Xu, KM Hemler, R AF Pincus, R Hannay, C Klein, SA Xu, KM Hemler, R TI Overlap assumptions for assumed probability distribution function cloud schemes in large-scale models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODELS; RESOLVING MODEL; RADAR DATA; PARAMETERIZATION; PRECIPITATION; VARIABILITY; STATISTICS; SIMULATION; LAYER AB [1] Cloud vertical structure influences the fluxes of precipitation and radiation throughout the atmosphere. This structure is not predicted in large-scale models but is instead applied in the form of "overlap assumptions.'' In their current guise, overlap assumptions apply to the presence or absence of clouds, and new data sets have led to the development of empirical formulations described by exponential decay from maximum to random overlap over a characteristic length scale. At the same time, cloud parameterizations in many large-scale models have been moving toward "assumed PDF'' schemes that predict the distribution of total water within each grid cell, which will require overlap assumptions that may be applied to cells with specified internal variability. This paper uses a month-long cloud-resolving model simulation of continental convection to develop overlap assumptions for use with assumed PDF cloud schemes in large-scale models. An observing system simulation experiment shows that overlap assumptions derived from millimeter-wavelength cloud radar observations can be strongly affected by the presence of precipitation and convective clouds and, to a lesser degree, by limited sampling and reliance on the frozen turbulence assumption. Current representations of overlap can be extended with good accuracy to treat the rank correlation of total water in each grid cell, which provides a natural way to treat vertical structure in assumed PDF cloud schemes. The scale length that describes an exponential fit to the rank correlation of total water depends on the state of the atmosphere: convection is associated with greater vertical coherence ( longer scale lengths), while wind shear decreases vertical coherence ( shorter scale lengths). The new overlap assumptions are evaluated using cloud physical properties, microphysical process rates, and top-of-atmosphere radiative fluxes. These quantities can be reproduced very well when the exact cloud structure is replaced with its statistical equivalent and somewhat less well when the time mean vertical structure is imposed. Overlap formulations that treat total water can also be used to determine the variability in clear-air relative humidity, which might be used by convection and aerosol parameterizations. C1 NOAA, Climate Diagnost Ctr, Cooperat Inst Res Environm Sci, Boulder, CO 80305 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP NOAA, Climate Diagnost Ctr, Cooperat Inst Res Environm Sci, 325 Broadway,R-CDC1, Boulder, CO 80305 USA. EM robert.pincus@colorado.edu RI Xu, Kuan-Man/B-7557-2013; Pincus, Robert/B-1723-2013; Klein, Stephen/H-4337-2016 OI Xu, Kuan-Man/0000-0001-7851-2629; Pincus, Robert/0000-0002-0016-3470; Klein, Stephen/0000-0002-5476-858X NR 27 TC 37 Z9 39 U1 0 U2 4 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 JUN 1 PY 2005 VL 110 IS D15 AR D15S09 DI 10.1029/2004JD005100 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 936CA UT WOS:000229829600001 ER PT J AU Yue, GK Lu, CH Wang, PH AF Yue, GK Lu, CH Wang, PH TI Comparing aerosol extinctions measured by Stratospheric Aerosol and Gas Experiment (SAGE) II and III satellite experiments in 2002 and 2003 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INTEGRAL PROPERTIES; SAM-II; INSTRUMENT; OZONE; RETRIEVAL AB [1] SAGE II and SAGE III are two satellite experiments designed to measure aerosol extinctions and concentrations of trace gases in the atmosphere by using the techniques of solar and/or lunar occultation. SAGE II was launched in October 1984, while SAGE III was launched in December 2001. Four of the nine aerosol channels used by SAGE III are centered at wavelengths very close to that of the four SAGE II aerosol channels. Since 27 February 2002, the first day of SAGE III data set, there are occasions when SAGE II and III measurement locations on the same day are nearly coincident, thereby providing opportunities for a unique measurement comparison. In this paper, the comparison of aerosol extinctions and optical depths at four wavelengths measured by SAGE II and SAGE III in 2002 and 2003 is reported. It was found that in the main aerosol layer, between about 18 to 26 km, differences are less than about 30%. Larger differences are shown at altitudes near the tropopause and around 30 km. In general, SAGE III extinctions at 385 nm are higher than that measured by SAGE II, but the opposite is true for 1020 nm. At 452 nm, SAGE II and SAGE III extinctions are in good agreement and the differences are about 10 to 15%. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RS Informat Syst, Mclean, VA USA. Sci & Technol Corp, Hampton, VA 23666 USA. RP Yue, GK (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM g.k.yue@larc.nasa.gov NR 16 TC 6 Z9 7 U1 1 U2 3 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 JUN 1 PY 2005 VL 110 IS D11 AR D11202 DI 10.1029/2004JD005421 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 936BW UT WOS:000229829100005 ER PT J AU Powell, DC Markus, T Stossel, A AF Powell, DC Markus, T Stossel, A TI Effects of snow depth forcing on Southern Ocean sea ice simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ANTARCTIC PACK-ICE; THICKNESS DISTRIBUTION; WEDDELL SEA; MODEL; COVER; SENSITIVITY; WINTER; BELLINGSHAUSEN; ASSIMILATION; VARIABILITY AB [1] The aim of this study is to investigate the competing effects of a snow layer's insulation and snow-ice formation on thermodynamic sea ice thickness growth in response to changes in precipitation. Using optimal interpolation to assimilate Special Sensor Microwave/ Imager satellite-derived snow depths into a dynamic-thermodynamic sea ice model, we create a daily assimilated snow depth product for the years 1992 - 2003. The assimilated snow depths are used to adjust National Centers for Environmental Prediction/ National Center for Atmospheric Research reanalysis precipitation rates which subsequently force the model's snow depths and freshwater input. These adjusted precipitation rates are used to create a best estimate snow depth climatology. This climatology provides the basis for a series of sensitivity experiments. Precipitation rates are varied from 0.0 to a doubling of the present day precipitation. Initially, sea ice volume decreases with increasing precipitation rate multiplying factor (PRMF) because of the insulation effects of a deeper snow layer. The turning point at which the insulation effect becomes balanced by the snow to ice conversion effect ranges from PRMF = 0.50 to PRMF = 0.75, depending upon the snow thermal conductivity and density. This suggests that with present-day precipitation rates the snow effect on Southern Ocean sea ice is dominated by snow-ice formation rather than the snow's insulation. C1 Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 20715 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 20715 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. Texas A&M Univ, Dept Oceanog, College Stn, TX 77843 USA. RP Powell, DC (reprint author), Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 20715 USA. EM thorsten.markus@nasa.gov RI Markus, Thorsten/D-5365-2012 NR 43 TC 22 Z9 22 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 1 PY 2005 VL 110 IS C6 AR C06001 DI 10.1029/2003JC002212 PG 11 WC Oceanography SC Oceanography GA 936CF UT WOS:000229830300001 ER PT J AU Juarez, JC Maier, EW Choi, KN Taylor, HF AF Juarez, JC Maier, EW Choi, KN Taylor, HF TI Distributed fiber-optic intrusion sensor system SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article DE distributed sensor; Er : fiber laser; fiber sensor; intrusion sensor; optical-phase sensor; optical-time-domain reflectometer (OTDR); perimeter security ID TIME-DOMAIN REFLECTOMETRY; SAGNAC INTERFEROMETER; LASER; RING AB A distributed sensor system for detecting and locating intruders based on the phase-sensitive optical-time-domain reflectometer (phi-OTDR) is described. The sensing element is a cabled single-mode telecommunications fiber buried along the monitored perimeter. Light pulses from a continuous-wave Er:fiber Fabry-Perot laser with a narrow (approximate to 3 kHz) instantaneous linewidth and low (few kilohertz per second) frequency drift are injected into one end of the fiber, and the backscattered light is monitored with a photodetector. The effect of phase changes resulting from the pressure of the intruder on the ground immediately above the buried fiber are sensed by subtracting a phi-OTDR trace from an earlier stored trace. In laboratory tests with fiber on reels, the effects of localized phase perturbations induced by a piezoelectric fiber stretcher on phi-OTDR traces were observed. In field tests, people walking on the ground above a buried fiber cable induced phase shifts of several-pi radians. C1 Texas A&M Univ, Dept Elect Engn, College Stn, TX 77843 USA. Natl Aeronaut & Space Adm, Miss Operat Directorate, Houston, TX 77058 USA. Incheon City Coll, Dept Commun Engn, Inchon 402750, South Korea. RP Juarez, JC (reprint author), Texas A&M Univ, Dept Elect Engn, College Stn, TX 77843 USA. EM jcj@tamu.edu; eric.maier1@jsc.nasa.gov; knchoi@icc.ac.kr; taylor@ee.tamu.edu NR 22 TC 170 Z9 207 U1 12 U2 65 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD JUN PY 2005 VL 23 IS 6 BP 2081 EP 2087 DI 10.1109/JLT.2005.849924 PG 7 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA 935BB UT WOS:000229752700013 ER PT J AU Xu, TB Su, J AF Xu, TB Su, J TI Design, modeling, fabrication, and performances of bridge-type high-performance electroactive polymer micromachined actuators SO JOURNAL OF MICROELECTROMECHANICAL SYSTEMS LA English DT Article DE displacement; displacement voltage ratio (DVR); effective strain; electroactive polymer (EAP); fluid; mass; mass sensor; microactuator; resonance ID POLY(VINYLIDENE FLUORIDE-TRIFLUOROETHYLENE) COPOLYMER; TRANSVERSE STRAIN RESPONSES; MICROELECTROMECHANICAL SYSTEMS; MICROPUMPS; BEHAVIOR; SILICON; AIR AB Bridge-type high-performance polymer micromachined actuators (PMATs) based on an electroactive polymer, modified poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer had been designed, modeled, fabricated, and characterized. The results show that the material enables the PMAT to exhibit a high stroke level (60 pm displacement with 1 nun lateral dimension microactuator) with high-load capability and high-displacement voltage ratio (DVR) over a broad frequency range (> 100 kHz). The stroke reduction in fluid (Silicone oil) is less than 5% comparing with the displacement in air. Impedance analysis and displacement measurement indicate that the PMAT has strong resonance behavior and the resonance frequency can be tuned by varying the dc bias field. Furthermore, the resonance peak, as expected by theoretical study, shifted to 6.5 times lower in fluid than in air with the mechanical Q value reduction less than 40%. In addition, the performance of the PMAT was modeled based on the elastic and electromechanical properties of the materials utilized in the PMAT and the configuration of the device. The comparison between the model and the experimental result shows a good agreement and validates the model as an effective method for the future development of PMAT for various applications. The high frequency response and respected performance in fluid medium demonstrate that the PMAT has potential for high performance MEMS components in the applications of microfluid systems, air dynamic control, under water transducers, and mass sensors, etc. C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Xu, TB (reprint author), Natl Inst Aerosp, 144 Res Dr, Hampton, VA 23666 USA. EM t.xu@larc.nasa.gov; ji.su-1@nasa.gov NR 34 TC 2 Z9 2 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1057-7157 J9 J MICROELECTROMECH S JI J. Microelectromech. Syst. PD JUN PY 2005 VL 14 IS 3 BP 539 EP 547 DI 10.1109/JMEMS.2005.844744 PG 9 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation; Physics, Applied SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation; Physics GA 935AL UT WOS:000229751000013 ER PT J AU Yang, YL Gupta, MC Dudley, KL Lawrence, RW AF Yang, YL Gupta, MC Dudley, KL Lawrence, RW TI A comparative study of EMI shielding properties of carbon nanofiber and multi-walled carbon nanotube filled polymer composites SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE carbon nanofibers; multi-walled carbon nanotubes; polystyrene; composites; electrical conductivity; electromagnetic interference shielding ID BUTADIENE-STYRENE COMPOSITES; POLYSTYRENE COMPOSITES; MECHANICAL-PROPERTIES; ELECTRICAL-PROPERTIES; CONDUCTING POLYMERS; MORPHOLOGY AB Electromagnetic interference shielding properties of carbon nanofiber- and multi-walled carbon nanotube-filled polystyrene composites were investigated in the frequency range of 8.2-12.4 GHz (X-band). It was observed that the shielding effectiveness of composites was frequency independent, and increased with the increase of carbon nanofiber or nanotube loading. At the same filler loading, multi-walled carbon nanotube-filled polystyrene composites exhibited higher shielding effectiveness compared to those filled with carbon nanofibers. In particular, carbon nanotubes were more effective than nanofibers in providing high EMI shielding at low filler loadings. The experimental data showed that the shielding effectiveness of the composite containing 7 wt% carbon nanotubes could reach more than 26 dB, implying that such a composite can be used as a potential electromagnetic interference shielding material. The dominant shielding mechanism of carbon nanotube-filled polystyrene composites was also discussed. C1 Univ Virginia, Dept Elect & Comp Engn, Charlottesville, VA 22904 USA. NASA, Langley Res Ctr, Electromagnet Res Branch, Hampton, VA 23681 USA. RP Gupta, MC (reprint author), Univ Virginia, Dept Elect & Comp Engn, Charlottesville, VA 22904 USA. NR 27 TC 114 Z9 115 U1 4 U2 35 PU AMER SCIENTIFIC PUBLISHERS PI VALENCIA PA 26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD JUN PY 2005 VL 5 IS 6 BP 927 EP 931 DI 10.1166/jnn.2005.115 PG 5 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 935BA UT WOS:000229752600014 PM 16060155 ER PT J AU Ray, CS Reis, ST Brow, RK Holand, W Rheinberger, V AF Ray, CS Reis, ST Brow, RK Holand, W Rheinberger, V TI A new DTA method for measuring critical cooling rate for glass formation SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article AB A new differential thermal analysis (DTA) experimental method has been developed to determine the critical cooling rate for glass formation. R-c The method, which is found especially Suitable for melts that, upon cooling, have a small heat of crystallization or a very slow crystallization rate, has been verified using a 38Na(2)O 62SiO(2) (mol%) melt with a known R-c(similar to 19 degrees C/min), then used to determine R-c for two complex lithium silicate glass forming melts, The new method is rapid, easy to conduct and yields values for R-c that are in excellent agreement with the R-c values measured by standard DTA techniques, (c) 2005 Elsevier B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Missouri, Grad Ctr Mat Res, Dept Mat Sci & Engn, Rolla, MO 65409 USA. Ivoclar Vivadent AG, FL-9494 Schaan, Furstentum, Liechtenstein. RP Ray, CS (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM chandra.s.ray@nasa.gov NR 8 TC 24 Z9 24 U1 3 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUN 1 PY 2005 VL 351 IS 16-17 BP 1350 EP 1358 DI 10.1016/j.jnoncrysol.2005.03.029 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 935WP UT WOS:000229814400003 ER PT J AU Koh, JH Hsu, AT Akay, HU Liou, MF AF Koh, JH Hsu, AT Akay, HU Liou, MF TI Analysis of overall heat balance in self-heated proton-exchange-membrane fuel cells for temperature predictions SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT Fuel Cell Seminar 2004 CY 2004 CL San Antonio, TX DE PEM fuel cell; stack temperature; self-heating; heat loss AB The effect of self-heating and cooling by natural convection on a sustainable temperature of PEM fuel cell stacks was studied. Overall mass and heat balance equations are combined to predict self-heated temperatures at various operating conditions. Analyses show that the effect of a heat loss coefficient is more important than other variables such as air flow rate and surrounding temperature. The stack design variables such as active cell area and number of cells also have significant influence on self-controlled temperature. A lower Ohmic resistance of cells is expected to allow a wider range of current load applications. The proposed model can also be used to evaluate heat loss coefficient from measured stack performance and temperature data. Experiments performed on a seven-cell stack of 50 cm(2) active area were used to provide data for the validation of the model. (c) 2005 Elsevier B.V. All rights reserved. C1 Indiana Univ Purdue Univ, Dept Mech Engn, Indianapolis, IN 46202 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Hsu, AT (reprint author), Indiana Univ Purdue Univ, Dept Mech Engn, 723 W Michigan St,SL-260, Indianapolis, IN 46202 USA. EM anhsu@iupui.edu NR 6 TC 14 Z9 14 U1 0 U2 1 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 JUN 1 PY 2005 VL 144 IS 1 BP 122 EP 128 DI 10.1016/j.powsour.2004.12.055 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 934JT UT WOS:000229705800014 ER PT J AU Dyers, L Van Derveer, D Bu, XR AF Dyers, L Van Derveer, D Bu, XR TI Synthesis and molecular structure of a bimetallic salen complex containing Zn and La: A disordered nitrate group dancing between two metal centers SO JOURNAL OF RARE EARTHS LA English DT Article; Proceedings Paper CT International Conference on Rare Earth Ceramics and Glass CY 2004 CL Yangzhou, PEOPLES R CHINA SP Chinese Soc Rare Earths DE bimetallic complex; zinc; lanthannm; rare earths ID CRYSTAL-STRUCTURE; EPOXIDATION; OLEFINS AB A new bimetallic complex containing Zn and La was prepared from a salen ligand possessing methoxyl groups at the 3, 3'-positions. The structural feature is that one of nitrate groups is disordered and displaced between two metal centers. Crystal system: Triclinic space group: P-1, Z=2. a=0.82714 (17) nm, b=1.3484 (3) (1) nm, and c = 1.3898(3) (1) nm, alpha = 79.89(3)degrees, beta = 76.67(3)degrees, and gamma = 72.43(3)degrees. V = 1.428.6(5) nm(3), Dx = 1.812 g center dot cm(-3). (Delta(p))(max) = 1.510 x 10(-3) enm(3), (Delta p)(min) = -1.503 x 10(-3) enm(3). Accordingly, two water molecules occupy the metal centers in the apical positions via the syn-geometry. C1 Clark Atlanta Univ, NASA, Ctr High Performance Polymers & Composites, Dept Chem, Atlanta, GA 30314 USA. Clemson Univ, Dept Chem, Clemson, SC 29634 USA. RP Bu, XR (reprint author), Clark Atlanta Univ, NASA, Ctr High Performance Polymers & Composites, Dept Chem, Atlanta, GA 30314 USA. EM xbu@cau.edu NR 15 TC 0 Z9 0 U1 0 U2 0 PU METALLURGICAL INDUSTRY PRESS PI BEIJING PA 2 XINJIEKOUWAI DAJIE, BEIJING 100088, PEOPLES R CHINA SN 1002-0721 J9 J RARE EARTH JI J. Rare Earths PD JUN PY 2005 VL 23 IS 3 BP 257 EP 261 AR PII 1002-0721(2005)03-0257-05 PG 5 WC Chemistry, Applied SC Chemistry GA 944XJ UT WOS:000230464100001 ER PT J AU Ting, DZY Cartoixa, X AF Ting, DZY Cartoixa, X TI Device concepts based on spin-dependent transmission in semiconductor heterostructures SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article DE spin filter; rashba effect; resonant tunneling; bulk inversion asymmetry ID TRANSISTOR; RELAXATION; TRANSPORT; HOLES AB We examine zero-magnetic-field spin-dependent transmission in nonmagnetic semiconductor heterostructures with structural inversion asymmetry (SIA) and bulk inversion asymmetry (BIA), and report spin devices concepts that exploit their properties. Our modeling results show that several design strategies could be used to achieve high spin filtering efficiencies. The current spin polarization of these devices is electrically controllable, and potentially amenable to high-speed spin modulation, and could be integrated in optoelectronic devices for added functionality. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Ting, DZY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 26 TC 6 Z9 6 U1 0 U2 3 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD JUN PY 2005 VL 18 IS 3 BP 411 EP 419 DI 10.1007/s10948-005-0018-x PG 9 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 985SN UT WOS:000233398900019 ER PT J AU Choi, SR Bansal, NP AF Choi, SR Bansal, NP TI Flexure strength, fracture toughness, and slow crack growth of YSZ/alumina composites at high temperatures SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PLATELET-REINFORCED 3Y-TZP; HOT-PRESSED SI3N4; MECHANICAL-PROPERTIES; ALUMINA; ZIRCONIA; CERAMICS; MICROSTRUCTURE; BEHAVIOR; FATIGUE AB Flexure strength and fracture toughness of zirconia-alumina composites, fabricated by hot pressing 10 mol% yttria-stabilized zirconia (10-YSZ) reinforced with 0-30 mol% alumina particulates or platelets, were determined as a function of alumina content at 1000 degrees C in air. Both strength and fracture toughness of the two composite systems increased with increasing alumina content. For a given alumina content, flexure strength of the particulate composites was greater than that of the platelet composites at higher alumina contents ( >= 20 mol%); whereas, fracture toughness of the platelet composites was greater than that of the particulate counterparts, regardless of the alumina content. The susceptibility to slow crack growth (SCG), determined at 1000 degrees C via constant stress-rate testing, was greatest for 30 mol% particulate composite with SCG parameter n = 5-8 and was least for 30 mol% platelet composite with n = 33. Elastic modulus of both composite systems decreased below 400 degrees C and then remained almost unchanged up to 1000 degrees C, forming a unique transition around 400 degrees C, irrespective of alumina content. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Choi, SR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM sung.r.choi@grc.nasa.gov NR 39 TC 12 Z9 12 U1 0 U2 9 PU BLACKWELL PUBLISHING INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUN PY 2005 VL 88 IS 6 BP 1474 EP 1480 DI 10.1111/j.1551-2916.2005.00252.x PG 7 WC Materials Science, Ceramics SC Materials Science GA 930IW UT WOS:000229410300019 ER PT J AU Choi, SR Bansal, NP Verrilli, MJ AF Choi, SR Bansal, NP Verrilli, MJ TI Delayed failure of ceramic matrix composites in tension at elevated temperatures SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article DE composites; strength; stress-rupture testing; slow crack growth; lifetime; SiC/SiC ID CRACK-GROWTH; STRENGTH; GLASS; CFCCS AB Ultimate tensile strength of five different continuous fiber-reinforced ceramic matrix composites (CMCs), including SiCf/BSAS (two dimensional (2D), 2 types), SiCf/MAS (2D), SiCf/SiC (2D), and Q /SiC (2D, 2 types), was determined as a function of test rate at 1100-1200 degrees C in air. All five CMCs exhibited a significant dependency of ultimate tensile strength on test rate such that the ultimate tensile strength decreased with decreasing test rate. The dependency of ultimate tensile strength on test rate, the applicability of preload technique, and the predictability of life from one loading configuration (constant stress-rate loading) to another (constant stress loading) all suggested that the overall, phenomenological delayed failure of the CMCs would be governed by a power-law type of slow crack growth. (c) 2004 Elsevier Ltd. All rights reserved. C1 NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Choi, SR (reprint author), NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. EM sung.r.choi@grc.nasa.gov NR 17 TC 10 Z9 11 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PD JUN PY 2005 VL 25 IS 9 BP 1629 EP 1636 DI 10.1016/j.jeurceramsoc.2004.05.024 PG 8 WC Materials Science, Ceramics SC Materials Science GA 938YR UT WOS:000230039800020 ER PT J AU Brill, MH Larimer, J AF Brill, MH Larimer, J TI Avoiding on-screen metamerism in N-primary displays SO JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY LA English DT Article DE multi-primary display; metamerism; color; Binet-Cauchy theorem AB The present paper describes a method for using more than three primaries in an additive-primary display. The method ensures that each tristimulus specification can be produced in no more than one way, even if a non-singular filter (i.e., one that does not reduce the dimensionality of color-matching space) is interposed between the screen and the viewer. Starting with N primaries, the method uses only three at a time, but these may be composites - fixed linear combinations of the original N. As further insurance against on-screen metamerism, a criterion on the primary spectra, based on the Binet-Cauchy theorem, ensures that a triad of primaries keeps its right/left-handed chromaticity ordering when a filter is interposed. C1 Datacolor Color Vis, Lawrenceville, NJ 08648 USA. NASA, Ames Res Ctr, Moffett Field, CA 90535 USA. RP Brill, MH (reprint author), Datacolor Color Vis, 5 Princess Rd, Lawrenceville, NJ 08648 USA. EM jlarimer@mail.arc.nasa.gov NR 7 TC 7 Z9 7 U1 0 U2 1 PU SOC INFORMATION DISPLAY PI SAN JOSE PA 610 S SECOND STREET, SAN JOSE, CA 95112 USA SN 1071-0922 J9 J SOC INF DISPLAY JI J. Soc. Inf. Disp. PD JUN PY 2005 VL 13 IS 6 BP 509 EP 516 DI 10.1889/1.1974003 PG 8 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA 025PM UT WOS:000236279000009 ER PT J AU Hasanyan, D Librescu, L Qin, ZM Young, RD AF Hasanyan, D Librescu, L Qin, ZM Young, RD TI Thermoelastic cracked plates carrying nonstationary electrical current SO JOURNAL OF THERMAL STRESSES LA English DT Article; Proceedings Paper CT 6th International Congress on Thermal Stresses CY MAY 26-29, 2005 CL Vienna, AUSTRIA DE thermoelastic; cracks; thermo- and electro-conductive plates; deceleration; crack propagation and arrest; Joule heating ID MAGNETIC-FIELD AB Problems related to the distribution of electromagnetic field and of the Joule heating along/around the cracks in a thermo- and electroconductive plate are addressed. It is assumed that the plate carries a nonstationary electrical current and contains two finite collinear cracks that are located perpendicular to the current direction. The cracks are free of mechanical loads. The formulated problem is reduced to a system of singular integral equations with Cauchy-type singular kernels and solved numerically. The influence of interaction of the cracks as well as non-stationarity of the current on the distribution of current and Joule heating are clarified. The results are instrumental toward arrest and de-acceleration of crack propagation in electro-conductive material structures. C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Librescu, L (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. EM librescu@vt.edu NR 13 TC 14 Z9 15 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-5739 J9 J THERM STRESSES JI J. Therm. Stresses PD JUN-JUL PY 2005 VL 28 IS 6-7 BP 729 EP 745 DI 10.1080/01495730590932715 PG 17 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA 924US UT WOS:000229006600005 ER PT J AU Turner, TL AF Turner, TL TI SMA hybrid composites for dynamic response abatement applications SO JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME LA English DT Article DE shape memory alloys; nitinol; hybrid composites; embedded actuators; constitutive modeling; adaptive stiffening; thermal buckling; thermal post-buckling; thermoelastic stability; random response; sonic fatigue; transmission loss; noise transmission ID SHAPE-MEMORY ALLOY; NITINOL-REINFORCED PLATES; THERMOELASTIC MODEL; LAMINATED PLATES; ACTIVE VIBRATION; ACTUATORS; FIBERS; BEAMS; WIRES AB A recently developed constitutive model and a finite element formulation for predicting the thermomechanical response of shape memory alloy hybrid composite (SMAHC) structures are briefly described. Attention is focused on constrained recovery behavior in this study, but the constitutive formulation is also applicable to modeling restrained or free recovery. Numerical results are shown for glass-epoxy panel specimens with embedded Nitinol actuators subjected to thermal and acoustic loads. Control of thermal buckling, random response, sonic fatigue, and noise transmission are demonstrated and compared to conventional approaches including addition of conventional composite layers and a constrained layer damping treatment. The SMAHC approach is shown to be significantly more effective in the dynamic response abatement applications than the conventional approaches. The impetus for the control is an extremely weight-efficient stiffening effect, which makes the SMAHC approach ideally suited for the difficult problem of low-frequency vibration and noise control. Extremely wide-band control may be possible by combined SMAHC-conventional or SMAHC-active approaches because of the complementary control mechanisms. C1 NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. RP Turner, TL (reprint author), NASA, Langley Res Ctr, Struct Acoust Branch, MS 463, Hampton, VA 23681 USA. EM t.l.turner@nasa.gov NR 38 TC 6 Z9 6 U1 1 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 1048-9002 J9 J VIB ACOUST JI J. Vib. Acoust.-Trans. ASME PD JUN PY 2005 VL 127 IS 3 BP 273 EP 279 DI 10.1115/1.1888588 PG 7 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 936IH UT WOS:000229848200007 ER PT J AU Powell, MJ Sutton, JN Del Castillo, CE Timperman, AI AF Powell, MJ Sutton, JN Del Castillo, CE Timperman, AI TI Marine proteomics: generation of sequence tags for dissolved proteins in seawater using tandem mass spectrometry SO MARINE CHEMISTRY LA English DT Article DE ultrafiltration; methanol/chloroform/water precipitation; dissolved organic matter; dissolved proteins; proteomics; tandem mass spectrometry ID ORGANIC-MATTER; LIQUID-CHROMATOGRAPHY; OCEANIC WATERS; PSEUDOMONAS-AERUGINOSA; BIOGEOCHEMICAL CYCLES; ESCHERICHIA-COLI; AMINO-ACIDS; IDENTIFICATION; BACTERIA; CARBON AB Dissolved proteins in seawater samples from the Gulf of Mexico were concentrated using tangential flow ultrafiltration and methanol/chloroform/water precipitation. Following concentration and purification, two different separation methods were employed. In one method, intact proteins were separated by SDS-PAGE and digested enzymatically in-gel. In the second method, the peptides resulting from a solution proteolytic digest of the whole protein pellet mixture were separated by capillary HPLC. In both methods, the final chromatographic separation was coupled on-line with a mass spectrometer using an electrospray interface, and peptide CID spectra were collected using tandem mass spectrometry (MS). De novo sequencing of the peptide tandem mass spectra generated short amino acid sequences (peptide tags) that were used to search databases for protein class and source information. Trends of conserved sequences for two specific classes of proteins were observed: membrane/envelope proteins and enzymes. Similarity searching of peptide tags produced identification of conserved sequences from several protein homologues originating from many different species, including: long chain fatty acyl CoA synthetase, anthranilate synthase,ribulose bisphosphate carboxylase, and luminal binding protein. These results provide new insight into the sources and production mechanisms for dissolved organic matter (DOM), as there is direct evidence for dissolved proteins other than the bacterial outer membrane proteins reported by Tanoue et al. Furthermore, the data presented herein support the idea that physical protection and selective preservation are not mutually exclusive survival mechanisms, but rather these two models are dependent upon one another for explaining the survival of refractory dissolved proteins in seawater. (C) 2004 Elsevier B.V. All rights reserved. C1 W Virginia Univ, Dept Chem, Morgantown, WV 26506 USA. NASA, Stennis Space Ctr, MS 39529 USA. RP Timperman, AI (reprint author), W Virginia Univ, Dept Chem, Morgantown, WV 26506 USA. EM atimperm@wvu.edu RI Del Castillo, Carlos/N-2601-2013 NR 67 TC 39 Z9 40 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD JUN 1 PY 2005 VL 95 IS 3-4 BP 183 EP 198 DI 10.1016/j.marchem.2004.09.004 PG 16 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 934GO UT WOS:000229695100003 ER PT J AU Maleki, L Prestage, J AF Maleki, L Prestage, J TI Applications of clocks and frequency standards: from the routine to tests of fundamental models SO METROLOGIA LA English DT Article ID GRAVITATIONAL-RADIATION; SPECIAL RELATIVITY; HYDROGEN-MASER; ATOMIC CLOCKS; GALILEO PROBE; TRACKING; SPACE; JUPITER AB The traditional applications of clocks and oscillators in navigation and scientific research continue to grow as new and more widespread applications emerge. Today, clocks and oscillators regulate the speed and efficiency of virtually every human endeavour ranging from the mundane to the exotic. In this paper we discuss some of the applications that require the service of high performance clocks and oscillators. In particular, we discuss space applications of clocks for navigation and scientific experiments. We also present a discussion of satellite navigation systems, especially the Global Positioning System, and comment on time dissemination over the Internet. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Maleki, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 31 TC 3 Z9 3 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0026-1394 J9 METROLOGIA JI Metrologia PD JUN PY 2005 VL 42 IS 3 SI SI BP S145 EP S153 DI 10.1088/0026-1394/42/3/S15 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 947OB UT WOS:000230654500016 ER PT J AU Qi, D Hinkley, J He, GW AF Qi, D Hinkley, J He, GW TI Molecular dynamics simulation of thermal and mechanical properties of polyimide-carbon-nanotube composites SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID AROMATIC-POLYSULFONE SYSTEM; ELASTIC PROPERTIES; FORCE-FIELD; POLYMER; TUBULES AB An aromatic polyimide and its mixture with randomly distributed carbon nanotubes (NTs) are simulated by using molecular dynamics, repeated energy minimization and cooling processes. The glass transition temperatures are identified through volume-temperature curves. Stress-strain curves, Young's moduli, densities and Poisson ratios are computed at different temperatures. It is demonstrated that the carbon NT reduces the softening effects of temperature on mechanical properties and increases the ability to resist deformation. C1 Western Michigan Univ, Coll Engn & Appl Sci, Dept Paper Engn, Kalamazoo, MI 49008 USA. NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. Chinese Acad Sci, Inst Mech, Lab Nonlinear Mech, Beijing 100080, Peoples R China. RP Qi, D (reprint author), Western Michigan Univ, Coll Engn & Appl Sci, Dept Paper Engn, Kalamazoo, MI 49008 USA. NR 25 TC 48 Z9 48 U1 3 U2 22 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JUN PY 2005 VL 13 IS 4 BP 493 EP 507 DI 10.1088/0965-0393/13/4/002 PG 15 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 938XO UT WOS:000230036900002 ER PT J AU Church, MJ Reed, D Dotani, T Balucinska-Church, A Smale, AP AF Church, MJ Reed, D Dotani, T Balucinska-Church, A Smale, AP TI Discovery of absorption features of the accretion disc corona and systematic acceleration of the X-ray burst rate in XB 1323-619 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries : close; stars : neutron; X-rays : binaries; X-rays : individual : XB 1323-619 ID PERIODIC INTENSITY DIPS; BEPPOSAX OBSERVATION; EMISSION; COMPTONIZATION; SPECTRUM; CATALOG; MODELS; LMXB; LINE AB We present results from analysis of the observation of the dipping, quasi-periodic bursting low mass X-ray binary XB 1323-619 made with XMM-Newton in 2003 January. In spectral analysis of the non-dip, non-burst EPIC PN spectrum, a number of absorption lines were discovered, notably at 6.70 and 6.98 keV, which we identify with scattering by high ionization state ions Fe XXV and Fe XXVI. Such features have been seen in other dipping sources, but their origin was not understood. Curve of growth analysis provided a consistent solution in which the line ratio was reproduced assuming collisional ionization with kT = 31 keV, close to the electron temperature we previously determined for the accretion disc corona (ADC) in this source. We thus propose that the absorption lines in the dipping low mass X-ray binaries (LMXB) are produced in the ADC. Spectral evolution in dipping was well described by the progressive covering model, which we have previously shown to give very good explanations of many dipping sources. We discuss the proposal of Boirin et al. (2004b), based on analysis of the present observation, that spectral evolution in all of the dipping LMXB may be explained by subjecting the continuum to a highly ionized absorber. This would require a decrease in X-ray intensity by a factor of similar to 3 in dipping at energies where photoelectric absorption is not effective (40-100 keV), which previous BeppoSAX analysis of several sources firmly rules out. In XB 1323-619, any decrease was less than 10 10 per cent and so the ionized absorber proposal can be ruled out. We find a remarkable linear increase in the rate of X-ray bursts with time over the 14-yr period since 1989 and a systematic non-linear increase in source luminosity (L). The linear variation of burst rate with L shows that the burst rate is proportional to mass accretion rate and if continued implies that the gap between bursts will become zero on 2008 January 11. In reality, we expect the source to undergo a transition from X-ray bursting to X-ray flaring, which would confirm the suggestion we previously made that flaring is unstable nuclear burning effectively consisting of a superposition of X-ray bursts. C1 Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. Jagiellonian Univ, Astron Observ, PL-30244 Krakow, Poland. Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. NASA, Div Astron & Phys, Off Space Sci, Washington, DC 20546 USA. RP Church, MJ (reprint author), Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. EM mjc@star.sr.bham.ac.uk NR 38 TC 20 Z9 20 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUN 1 PY 2005 VL 359 IS 4 BP 1336 EP 1344 DI 10.1111/j.1365-2966.2005.08728.x PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 933NQ UT WOS:000229640600010 ER PT J AU Stevens, B Moeng, CH Ackerman, AS Bretherton, CS Chlond, A De Roode, S Edwards, J Golaz, JC Jiang, HL Khairoutdinov, M Kirkpatrick, MP Lewellen, DC Lock, A Muller, F Stevens, DE Whelan, E Zhu, P AF Stevens, B Moeng, CH Ackerman, AS Bretherton, CS Chlond, A De Roode, S Edwards, J Golaz, JC Jiang, HL Khairoutdinov, M Kirkpatrick, MP Lewellen, DC Lock, A Muller, F Stevens, DE Whelan, E Zhu, P TI Evaluation of large-Eddy simulations via observations of nocturnal marine stratocumulus SO MONTHLY WEATHER REVIEW LA English DT Article ID TOP ENTRAINMENT INSTABILITY; BOUNDARY-LAYERS; ADVECTION SCHEME; MIXED LAYERS; NUMERICAL-MODELS; STRONG INVERSION; TURBULENT-FLOW; CLOUD; PARAMETERIZATION; SENSITIVITIES AB Data from the first research flight (RF01) of the second Dynamics and Chemistry of Marine Stratocumulus (DYCOMS-II) field study are used to evaluate the fidelity with which large-eddy simulations (LESs) can represent the turbulent structure of stratocumulus-topped boundary layers. The initial data and forcings for this case placed it in an interesting part of parameter space, near the boundary where cloud-top mixing is thought to render the cloud layer unstable on the one hand, or tending toward a decoupled structure on the other hand. The basis of this evaluation consists of sixteen 4-h simulations from 10 modeling centers over grids whose vertical spacing was 5 m at the cloud-top interface and whose horizontal spacing was 35 m. Extensive sensitivity studies of both the configuration of the case and the numerical setup also enhanced the analysis. Overall it was found that (i) if efforts are made to reduce spurious mixing at cloud top, either by refining the vertical grid or limiting the effects of the subgrid model in this region, then the observed turbulent and thermodynamic structure of the layer can be reproduced with some fidelity; (ii) the base, or native configuration of most simulations greatly overestimated mixing at cloud top, tending toward a decoupled layer in which cloud liquid water path and turbulent intensities were grossly underestimated; (iii) the sensitivity of the simulations to the representation of mixing at cloud top is, to a certain extent, amplified by particulars of this case. Overall the results suggest that the use of LESs to map out the behavior of the stratocumulus-topped boundary layer in this interesting region of parameter space requires a more compelling representation of processes at cloud top. In the absence of significant leaps in the understanding of subgrid-scale (SGS) physics, such a representation can only be achieved by a significant refinement in resolution-a refinement that, while conceivable given existing resources, is probably still beyond the reach of most centers. C1 Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Ames Res Ctr, Moffett Field, CA USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Max Planck Inst Meteorol, Hamburg, Germany. Inst Marine & Atmospher Res, Utrecht, Netherlands. IBM Business Consulting Serv, Boulder, CO USA. CNR, Naval Res Lab, Monterey, CA USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Univ Tasmania, Sch Engn, Hobart, Tas 7001, Australia. W Virginia Univ, MAE Dept, Morgantown, WV 26506 USA. Met Off, Exeter, Devon, England. Lawrence Livermore Natl Lab, Livermore, CA USA. RP Stevens, DE (reprint author), Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, 405 Hilgard Ave,Box 951565, Los Angeles, CA 90095 USA. EM bstevens@atmos.ucla.edu RI Lewellen, David/B-1453-2008; Ackerman, Andrew/D-4433-2012; de Roode, Stephan/J-8611-2012; Stevens, Bjorn/A-1757-2013; Golaz, Jean-Christophe/D-5007-2014; Jiang, Hongli/N-3281-2014; OI Ackerman, Andrew/0000-0003-0254-6253; de Roode, Stephan/0000-0003-3217-8009; Stevens, Bjorn/0000-0003-3795-0475; Golaz, Jean-Christophe/0000-0003-1616-5435; Kirkpatrick, Michael/0000-0002-7157-6440 NR 46 TC 241 Z9 242 U1 1 U2 28 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 2005 VL 133 IS 6 BP 1443 EP 1462 DI 10.1175/MWR2930.1 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 938UD UT WOS:000230028000003 ER PT J AU Demoz, BB Starr, DOC Evans, KD Lare, AR Whiteman, DN Schwemmer, G Ferrare, RA Goldsmith, JEM Bisson, SE AF Demoz, BB Starr, DOC Evans, KD Lare, AR Whiteman, DN Schwemmer, G Ferrare, RA Goldsmith, JEM Bisson, SE TI The cold front of 15 April 1994 over the central United States. Part I: Observations SO MONTHLY WEATHER REVIEW LA English DT Article ID ATMOSPHERIC UNDULAR BORE; WATER-VAPOR MEASUREMENTS; INTERNAL GRAVITY-WAVES; RAMAN LIDAR; MORNING GLORY; SOLITARY WAVE; NONLINEAR-WAVES; RADIATION; CLOUD; CARPENTARIA AB Detailed observations of the interactions of a cold front and a dryline over the central United States that led to dramatic undulations in the boundary layer, including an undular bore, are investigated using high-resolution water vapor mixing ratio profiles measured by Raman lidars. The lidar-derived water vapor mixing ratio profiles revealed the complex interaction between a dryline and a cold-frontal system. An elevated, well-mixed, and deep midtropospheric layer, as well as a sharp transition (between 5- and 6-km altitude) to a drier region aloft, was observed. The moisture oscillations due to the undular bore and the mixing of the prefrontal air mass with the cold air at the frontal surface are all well depicted. The enhanced precipitable water vapor and roll clouds, the undulations associated with the bore, the strong vertical circulation and mixing that led to the increase in the depth of the low-level moist layer, and the subsequent lifting of this moist layer by the cold-frontal surface, as well as the feeder flow behind the cold front, are clearly indicated. A synthesis of the Raman lidar-measured water vapor mixing ratio profiles, satellite, radiometer, tower, and Oklahoma Mesonet data indicated that the undular bore was triggered by the approaching cold front and propagated south-southeastward. The observed and calculated bore speeds were in reasonable agreement. Wave-ducting analysis showed that favorable wave-trapping mechanisms existed; a low-level stable layer capped by an inversion, a well-mixed michropospheric layer, and wind curvature from a low-level jet were found. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Baltimore, MD 21201 USA. L3 Commun Govt Serv Inc, Chantilly, VA USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Sandia Natl Labs, Livermore, CA USA. RP Demoz, BB (reprint author), NASA, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. EM belay.b.demoz@nasa.gov RI Demoz, Belay/N-4130-2014 NR 63 TC 6 Z9 6 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 2005 VL 133 IS 6 BP 1525 EP 1543 DI 10.1175/MWR2932.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 938UD UT WOS:000230028000007 ER PT J AU Wang, JJ Carey, LD AF Wang, JJ Carey, LD TI The development and structure of an oceanic squall-line system during the South China Sea Monsoon Experiment SO MONTHLY WEATHER REVIEW LA English DT Article ID MESOSCALE CONVECTIVE SYSTEMS; VERTICAL WIND SHEAR; TOGA-COARE; KINEMATIC STRUCTURE; SUMMER MONSOON; FEBRUARY 1993; NUMERICAL-SIMULATION; STORM STRUCTURE; TRMM-LBA; EVOLUTION AB A primary goal of the South China Sea Monsoon Experiment (SCSMEX), a major field campaign of the Tropical Rainfall Measuring Mission (TRMM), is to define the initiation, structure, evolution, and dynamics of precipitation processes associated with the onset of the South China Sea (SCS) summer monsoon. In this study, dual-Doppler and dual-polarimetric radar analysis techniques are used to investigate the development and structure of a squall-line system observed on 24 May 1998. The focus is the linkage between the airflow and the microphysical fields through the system. The squall-line system, including three distinct lines, persisted from 1200 UTC 24 May to the following day. A detailed study was performed on the structure of the second and most intense line, lasting for over 10 h. Compared to tropical squall lines observed in other regions, this narrow squall-line system had some interesting features including 1) maximum reflectivity as high as 55 dBZ; 2) relatively little stratiform rainfall that preceded instead of trailed the convective line-, and 3) a broad vertical velocity maximum in the rear part of the system, rather than a narrow ribbon of vertical velocity maximum near the leading edge. Polarimetric radar-inferred microphysical (e.g., hydrometeor type, amount, and size) and rainfall properties are placed in the context of the mesoscale morphology and dual-Doppler-derived kinematics for this squall-line system. A comparison is made between results from this study for SCSMEX and the previous studies for the TRMM Large-Scale Biosphere-Atmosphere experiment (LBA). It was found that precipitation over the SCS monsoon region during the summer monsoon onset was similar to the precipitation over the Amazon monsoon region during the westerly regime of the TRMM-LBA, which has previously been found to be closer to typical conditions over tropical oceans. Both of these cases showed lower rain rates and rainwater contents, smaller raindrops, and significantly lower ice water contents between 5 and 8 km than the precipitation over the Amazon during the easterly regime of the TRMM-LBA with more tropical continental characteristics. C1 NASA, Goddard Space Flight Ctr, Mesoscale Atmospher Proc Branch, Greenbelt, MD 20771 USA. Univ Maryland, Goddard Ctr Earth Sci & Technol, Greenbelt, MD USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX USA. RP Wang, JJ (reprint author), NASA, Goddard Space Flight Ctr, Mesoscale Atmospher Proc Branch, Greenbelt, MD 20771 USA. EM jjwang@agnes.gsfc.nasa.gov NR 56 TC 19 Z9 21 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 2005 VL 133 IS 6 BP 1544 EP 1561 DI 10.1175/MWR2933.1 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 938UD UT WOS:000230028000008 ER PT J AU Wang, YH Kim, MJ Shan, HW Kittrell, C Fan, H Ericson, LM Hwang, WF Arepalli, S Hauge, RH Smalley, RE AF Wang, YH Kim, MJ Shan, HW Kittrell, C Fan, H Ericson, LM Hwang, WF Arepalli, S Hauge, RH Smalley, RE TI Continued growth of single-walled carbon nanotubes SO NANO LETTERS LA English DT Article ID CATALYTIC NANOPARTICLES; RAMAN-SPECTROSCOPY; SEPARATION; ADSORPTION; SURFACES AB We demonstrate the continued growth of single-walled carbon nanotubes (SWNTs) from ordered arrays of open-ended SWNTs in a way analogous to epitaxy. Nanometer-sized metal catalysts were docked to the SWNT open ends and subsequently activated to restart growth. SWNTs thus grown inherit the diameters and chirality from the seeded SWNTs, as indicated by the closely matched frequencies of Raman radial breathing modes before and after the growth. C1 Rice Univ, Dept Chem, Ctr Nanoscale Sci & Technol, Carbon Nanotechnol Lab, Houston, TX 77251 USA. NASA, Lyndon B Johnson Space Ctr, GB Tech, Houston, TX 77058 USA. RP Smalley, RE (reprint author), Rice Univ, Dept Chem, Ctr Nanoscale Sci & Technol, Carbon Nanotechnol Lab, POB 1892,MS-100, Houston, TX 77251 USA. EM smalley@rice.edu RI Wang, YuHuang/B-4738-2009; Hauge, Robert/A-7008-2011 OI Wang, YuHuang/0000-0002-5664-1849; Hauge, Robert/0000-0002-3656-0152 NR 39 TC 92 Z9 94 U1 2 U2 42 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD JUN PY 2005 VL 5 IS 6 BP 997 EP 1002 DI 10.1021/nl047851f PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 934SY UT WOS:000229729900001 PM 15943432 ER PT J AU Hash, DB Bell, MS Teo, KBK Cruden, BA Milne, WI Meyyappan, M AF Hash, DB Bell, MS Teo, KBK Cruden, BA Milne, WI Meyyappan, M TI An investigation of plasma chemistry for dc plasma enhanced chemical vapour deposition of carbon nanotubes and nanofibres SO NANOTECHNOLOGY LA English DT Article ID BEAM ARRAY LITHOGRAPHY; PHASE ION CHEMISTRY; ELECTRICAL CHARACTERISTICS; ORIENTATION CONTROL; CROSS-SECTIONS; GROWTH; FABRICATION; CVD; NANOSTRUCTURES; MICROCATHODES AB The role of plasma in plasma enhanced chemical vapour deposition of carbon nanotubes and nanofibres is investigated with both experimental and computational diagnostic techniques. A residual gas analysis (RGA) of a 12 mbar dc discharge with a C2H2/NH3 gas mixture is conducted near the Ni catalyst surface employed for carbon nanofibre growth. The results are corroborated with a 1D dc discharge model that solves for species densities, ion momentum, and ion, electron and neutral gas thermal energies. The effect of varying the plasma power from 0 to 200 W on the gas composition is studied. The dissociation efficiency of the plasma is demonstrated where over 50% of the feedstock is converted to a mixture of hydrogen, nitrogen and hydrogen cyanide at 200 W. Finally, the important role that endothermic ion-molecule reactions play in this conversion is, for the first time, established. Of these reactions, dissociative proton abstraction and collision-induced dissociation are of the greatest significance. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. Univ Cambridge, Dept Engn, Cambridge CB2 1PZ, England. RP Meyyappan, M (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM M.Meyyappan@nasa.gov NR 66 TC 34 Z9 35 U1 4 U2 14 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD JUN PY 2005 VL 16 IS 6 BP 925 EP 930 DI 10.1088/0957-4484/16/6/050 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 940KZ UT WOS:000230144700050 ER PT J AU Norman, EB Smith, AR Barghouty, AF Haight, RC Wender, SA AF Norman, EB Smith, AR Barghouty, AF Haight, RC Wender, SA TI Cosmic-ray production of Co-60 in double beta-decay source materials SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Norman, EB (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 3 TC 12 Z9 12 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 JUN PY 2005 VL 143 BP 508 EP 508 DI 10.1016/j.nuclphysbps.2005.01.173 PG 1 WC Physics, Particles & Fields SC Physics GA 920EP UT WOS:000228672500094 ER PT J AU Dove, JF Narayanan, R Bengale, A Flattery, J Keller, D Kornreich, P Jamison, TL AF Dove, JF Narayanan, R Bengale, A Flattery, J Keller, D Kornreich, P Jamison, TL TI Mathematical model of the absorption and gain in a Cd3P2 cylinder fiber SO OPTICAL ENGINEERING LA English DT Article DE fibers; semiconductors; amplifiers; absorption; gain AB A theoretical analysis of the light absorption and gain mechanisms in a Cd3P2 Semiconductor Cylinder Fiber is presented. The results of these calculations are in good agreement with previously published experimental data. Cd3P2 has two direct energy gaps, which both influence the gain mechanism. Pump light can be used to reduce the absorption. Stronger pump light that generates more charge carriers will produce net gain (gain above absorption compensation). The fiber exhibits gain over a very wide light wavelength bandwidth. (c) 2005 Society of Photo-Optical Instrumentation Engineers. C1 Dove Photon Inc, Rome, NY 13440 USA. Syracuse Univ, Dept Elect Engn & Comp Sci, Syracuse, NY 13244 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Dove, JF (reprint author), Dove Photon Inc, 227 W Domin St, Rome, NY 13440 USA. NR 5 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD JUN PY 2005 VL 44 IS 6 AR 065002 DI 10.1117/1.1924367 PG 9 WC Optics SC Optics GA 974KS UT WOS:000232590900029 ER PT J AU Huntington, EH Ralph, TC Harb, CC Schumaker, BL AF Huntington, EH Ralph, TC Harb, CC Schumaker, BL TI Quadrature-phase noise penalties of optically and electro-optically phase-locked lasers SO OPTICS COMMUNICATIONS LA English DT Article DE quantum optics; lasers; quantum noise ID LISA; AMPLIFICATION; STABILIZATION; LOCKING AB Focussing particularly on solid-state laser systems, the phase-noise penalties of laser injection-locking and electro-optical phase-locking are derived using linearised quantum mechanical models. The fundamental performance limit (minimum achievable output phase noise) for an injection-locked laser (IJL) system at low frequencies is equal to that of a standard phase-insensitive amplifier, whereas, in principle, that of a phase-locked laser (PLL) system can be better. At high frequencies, the output phase noise of the IJL system is limited by that of the master laser, while that of the PLL system tends to a weighted sum of contributions from the master and slave laser fields. Under conditions of large amplification, particularly where there has been significant attenuation, the noise penalties are shown to be substantial. Nonideal photodetector characteristics are shown to add significantly to the noise penalties for the PLL system. (C) 2005 Elsevier B.V. All rights reserved. C1 Univ New S Wales, Univ Coll, Sch Informat Technol & Elect Engn, Canberra, ACT 2600, Australia. Univ Queensland, Dept Phys, St Lucia, Qld 4072, Australia. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Huntington, EH (reprint author), Univ New S Wales, Univ Coll, Sch Informat Technol & Elect Engn, Canberra, ACT 2600, Australia. EM e.huntington@adfa.edu.au RI Ralph, Timothy/A-1858-2011; Huntington, Elanor/G-4081-2010 OI Huntington, Elanor/0000-0002-7154-0042 NR 16 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JUN 1 PY 2005 VL 250 IS 1-3 BP 178 EP 190 DI 10.1016/j.optcom.2005.02.023 PG 13 WC Optics SC Optics GA 932AZ UT WOS:000229527900024 ER PT J AU Ogbuji, L AF Ogbuji, L TI A table-top technique for assessing the blanching resistance of Cu alloys SO OXIDATION OF METALS LA English DT Article DE Cu alloys; blanching; oxidation-reduction cycling; weight changes AB A new method is described for the simple and straight-forward evaluation of a materials resistance to blanching, a mode of degradation that limits the life and performance of rocket engine thrust-cell liners. The method is based on cyclic exposure to oxidation and reduction with continuous monitoring of weight changes. Results obtained so far are in excellent agreement with known and expected blanching behavior of available Cu alloys, showing that this method provides an effective screening test for blanching susceptibility. C1 NASA, QSS Grp, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Ogbuji, L (reprint author), NASA, QSS Grp, Glenn Res Ctr, MS 106-1, Cleveland, OH 44135 USA. EM linus@ogbuji.net NR 11 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X J9 OXID MET JI Oxid. Met. PD JUN PY 2005 VL 63 IS 5-6 BP 383 EP 399 DI 10.1007/s11085-005-4393-2 PG 17 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 931TQ UT WOS:000229508800006 ER PT J AU Khakoo, MA Johnson, PV Ozkay, I Yan, P Trajmar, S Kanik, I AF Khakoo, MA Johnson, PV Ozkay, I Yan, P Trajmar, S Kanik, I TI Differential cross sections for the electron impact excitation of the A (3)Sigma(+)(u), B (3)Pi(g), W (3)Delta(u), B ' (3)Sigma(-)(u), a ' (1)Sigma(-)(u), a (1)Pi(g), w (1)Delta(u), and C (3)Pi(u) states of N-2 SO PHYSICAL REVIEW A LA English DT Article ID INTERMEDIATE ENERGY REGION; CONFIGURATION-INTERACTION; ROTATIONAL-EXCITATION; DIATOMIC-MOLECULES; INCIDENT ENERGIES; BAND SYSTEMS; SCATTERING; N2; NITROGEN; TRANSITION AB Measurements of differential cross sections for the electron-impact excitation of molecular nitrogen from the ground X (1)Sigma(g) (+)(v''=0) level to the A (3)Sigma(u) (+)(v(')), B (3)Pi(g)(v(')), W (3)Delta(u)(v(')), B-' (3)Sigma(u)(-)(v(')), a(') (1)Sigma(u) (-)(v(')), a (1)Pi(g)(v(')), w (1)Delta(u)(v(')), and C (3)Pi(u)(v(')) levels are presented. The data are obtained at the incident energies of 10, 12.5, 15, 17.5, 20, 30, 50, and 100 eV over the angular range of 5 degrees-130 degrees in 5 degrees intervals. The individual electronic state excitation differential cross sections are obtained by unfolding electron energy-loss spectra of molecular nitrogen using available semiempirical Frank-Condon factors. The data are compared to previous measurements and to available theory. We also make several important suggestions regarding future work that, like the present, relies on the unfolding of electron energy-loss spectra for obtaining differential cross sections. C1 Calif State Univ Fullerton, Dept Phys, Fullerton, CA 92834 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Troy High Sch, Fullerton, CA 92831 USA. RP Calif State Univ Fullerton, Dept Phys, Fullerton, CA 92834 USA. RI Johnson, Paul/D-4001-2009 OI Johnson, Paul/0000-0002-0186-8456 NR 49 TC 35 Z9 35 U1 1 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2005 VL 71 IS 6 AR 062703 DI 10.1103/PhysRevA.71.062703 PG 20 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 942ID UT WOS:000230275200082 ER PT J AU Zhou, ZH Uher, C Jewell, A Caillat, T AF Zhou, ZH Uher, C Jewell, A Caillat, T TI Influence of point-defect scattering on the lattice thermal conductivity of solid solution Co(Sb1-xAsx)(3) SO PHYSICAL REVIEW B LA English DT Article ID THERMOELECTRIC PROPERTIES; COSB3; SKUTTERUDITES; ALLOYS; IMPERFECTIONS; TEMPERATURES; CRYSTALS; MODEL AB We have investigated the transport properties of solid solutions of skutterudites based on Co(Sb1-xAsx)(3). Homogeneous solid solutions were prepared with As content x <= 0.1. The influence of point-defect scattering on the lattice thermal conductivity has been studied in detail. The lattice thermal conductivity decreases with the increasing content of As at all temperatures from 2 K to 700 K. Theoretical analysis indicates that the reduction of the lattice thermal conductivity with increasing As concentration can be explained by the enhanced point-defect scattering due to mass fluctuations and strain field fluctuations as As atoms substitute on the Sb sublattice. C1 Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. NR 28 TC 44 Z9 45 U1 3 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JUN PY 2005 VL 71 IS 23 AR 235209 DI 10.1103/PhysRevB.71.235209 PG 6 WC Physics, Condensed Matter SC Physics GA 942IT UT WOS:000230276800051 ER PT J AU Edlund, JA Tinto, M Krolak, A Nelemans, G AF Edlund, JA Tinto, M Krolak, A Nelemans, G TI White-dwarf-white-dwarf galactic background in the LISA data SO PHYSICAL REVIEW D LA English DT Article ID GRAVITATIONAL-RADIATION; BINARIES AB LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own Galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. Our approach relies on entirely analytic expressions of the LISA time-delay interferometric responses to the gravitational radiation emitted by such systems, which allows us to implement a computationally efficient and accurate simulation of the background in the LISA data. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. This suggests that, during this time period, LISA could search for other gravitational wave signals incoming from directions that are away from the galactic plane. Since the galactic white-dwarf background will be observed by LISA not as a stationary but rather as a cyclostationary random process with a period of 1 yr, we summarize the theory of cyclostationary random processes, present the corresponding generalized spectral method needed to characterize such process, and make a comparison between our analytic results and those obtained by applying our method to the simulated data. We find that, by measuring the generalized spectral components of the white-dwarf background, LISA will be able to infer properties of the distribution of the white-dwarf binary systems present in our Galaxy. C1 Albert Einstein Inst, Max Planck Inst Gravitat Phys, D-14476 Golm, Germany. Radboud Univ Nijmegen, Dept Astrophys, IMAPP, Nijmegen, Netherlands. Polish Acad Sci, Inst Math, Warsaw, Poland. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Jeffrey.A.Edlund@jpl.nasa.gov; Massimo.Tinto@jpl.nasa.gov; krolan@aei.mpg.de; nelemans@astro.ru.nl RI Nelemans, Gijs/D-3177-2012 OI Nelemans, Gijs/0000-0002-0752-2974 NR 25 TC 20 Z9 20 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 JUN PY 2005 VL 71 IS 12 AR 122003 DI 10.1103/PhysRevD.71.122003 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 942IM UT WOS:000230276100007 ER PT J AU Korycansky, DG Zahnle, KJ AF Korycansky, DG Zahnle, KJ TI Modeling crater populations on Venus and Titan SO PLANETARY AND SPACE SCIENCE LA English DT Article DE impact processes; craters; Venus; Titan ID HIGH-RESOLUTION SIMULATIONS; LARGE METEOROIDS; ATMOSPHERIC ENTRY; EARTHS ATMOSPHERE; 3D MODELS; IMPACTS; ASTEROIDS; DISRUPTION; JUPITER; BREAKUP AB We describe a model for crater populations on planets and satellites with dense atmospheres, like those of Venus and Titan. The model takes into account ablation (or mass shedding), pancaking, and fragmentation. Fragmentation is assumed to occur due to the hydrodynamic instabilities promoted by the impactors' deceleration in the atmosphere. Fragments that survive to hit the ground make craters or groups thereof. Crater sizes are estimated using standard laws in the gravity regime, modified to take into account impactor disruption. We use Monte Carlo methods to pick parameters from appropriate distributions of impactor mass, zenith angle, and velocity. Good fits to the Venus crater populations (including multiple crater fields) can be found with reasonable values of model parameters. An important aspect of the model is that it reproduces the dearth of small craters on Venus: this is due to a cutoff on crater formation we impose, when the expected crater would be smaller than the (dispersed) object that would make it. Hydrodynamic effects alone (ablation, pancaking, fragmentation) due to the passage of impactors through the atmosphere are insufficient to explain the lack of small craters. In our favored model, the observed number of craters (940) is produced by similar to 5500 impactors with masses > 10(15) gm, yielding an age of 730 +/- 110 Myr (1-sigma uncertainty) for the venusian surface. This figure does not take into account any uncertainties in crater scaling and impactor population characteristics, which probably increase the uncertainty to a factor of two in age. We apply the model with the same parameter values to Titan to predict crater populations under differing assumptions of impactor populations that reflect present conditions. We assume that the impactors (comets) are made of 50% porous ice. Predicted crater production rates are approximate to 190 craters (10(9) yr)(-1). The smallest craters on Titan are predicted to be approximate to 2km in diameter, and approximate to 5 crater fields (10(9) yr)(-1) are expected. If the impactors are composed of solid ice (density 0.92 gm cm(-3)), crater production rates increase by approximate to 70% and the smallest crater is predicted to be approximate to 1.6km in diameter. We give cratering rates for denser comets and atmospheres 0.1 and 10 times as thick as Titan's current atmosphere. We also explicitly address leading-trailing hemisphere asymmetries that might be seen if Titan's rotation rate were strictly synchronous over astronomical timescales: if that is the case, the ratio of crater production on the leading hemisphere to that on the trailing hemisphere is approximate to 4 : 1. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Calif Santa Cruz, Dept Earth Sci, CODEP, IGPP, Santa Cruz, CA 95064 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Korycansky, DG (reprint author), Univ Calif Santa Cruz, Dept Earth Sci, CODEP, IGPP, Santa Cruz, CA 95064 USA. EM kory@es.ucsc.edu NR 35 TC 29 Z9 29 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 JUN PY 2005 VL 53 IS 7 BP 695 EP 710 DI 10.1016/j.pss.2005.03.002 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 928BD UT WOS:000229245200001 ER PT J AU Sarrazin, P Blake, D Feldman, S Chipera, S Vaniman, D Bish, D AF Sarrazin, P Blake, D Feldman, S Chipera, S Vaniman, D Bish, D TI Field deployment of a portable X-ray diffraction/X-ray flourescence instrument on Mars analog terrain SO POWDER DIFFRACTION LA English DT Article; Proceedings Paper CT Denver X-ray Conference 2004 CY MAR, 2004 CL Denver, CO ID SOIL AB CheMin is a miniature X-ray diffraction/X-ray fluorescence instrument that is included in the payload of the Mars 2009 Mars Science Laboratory mission. A portable CheMin prototype was built to test the capability of the instrument for remote in situ mineralogical characterization of geological materials. The instrument was successfully deployed at a variety of Mars analog sites in Death Valley, CA, in May 2004. (c) 2005 International Centre for Diffraction Data. C1 InXitu, Mountain View, CA 94042 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Indiana Univ, Bloomington, IN 47405 USA. RP Sarrazin, P (reprint author), InXitu, POB 730, Mountain View, CA 94042 USA. EM psarrazin@inxitu.com NR 15 TC 29 Z9 29 U1 1 U2 12 PU J C P D S-INT CENTRE DIFFRACTION DATA PI NEWTOWN SQ PA 12 CAMPUS BLVD, NEWTOWN SQ, PA 19073-3273 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD JUN PY 2005 VL 20 IS 2 BP 128 EP 133 DI 10.1154/1.1913719 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA 935DA UT WOS:000229758400013 ER PT J AU Lathrop, WB Kaiser, MK AF Lathrop, WB Kaiser, MK TI Acquiring spatial knowledge while traveling simple and complex paths with immersive and nonimmersive interfaces SO PRESENCE-TELEOPERATORS AND VIRTUAL ENVIRONMENTS LA English DT Article ID VIRTUAL ENVIRONMENTS; LABYRINTHINE FUNCTION; ORIENTATION; INTEGRATION; LOCOMOTION; NAVIGATION; BUILDINGS; DISPLAYS; LAYOUT AB Exploration of virtual environments may be accomplished with different interface metaphors. Previous research suggests that vestibular and proprioceptive information provided by immersive interfaces facilitates spatial orientation on simple path-integration tasks. We examine whether these interface variables impact performance across paths of variable complexity. Our immersive interface provided all users the ability to conduct the search component of our task more efficiently. Our results, however, show that the immersive interface was no more effective than our nonimmersive one for maintaining orientation. In fact, the immersive interface had a negative impact on performance (absolute error) for individuals who had extensive experience with playing video games. When measured in terms of consistency of response, our results suggest that having extensive game-play experience will negatively impact orientation performance with both interfaces. We speculate that this is due to the conflicting nature of the skills that avid game players acquire in game-play versus those required to perform in our task. C1 Univ Calif Santa Cruz, Dept Psychol, Santa Cruz, CA 95064 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Lathrop, WB (reprint author), Univ Calif Santa Cruz, Dept Psychol, Santa Cruz, CA 95064 USA. EM steilskin@yahoo.com NR 36 TC 7 Z9 8 U1 2 U2 4 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 1054-7460 J9 PRESENCE-TELEOP VIRT JI Presence-Teleoper. Virtual Env. PD JUN PY 2005 VL 14 IS 3 BP 249 EP 263 DI 10.1162/105474605323384627 PG 15 WC Computer Science, Cybernetics; Computer Science, Software Engineering SC Computer Science GA 942US UT WOS:000230309000001 ER PT J AU Bernhardsdotter, ECMJ Ng, JD Garriott, OK Pusey, ML AF Bernhardsdotter, ECMJ Ng, JD Garriott, OK Pusey, ML TI Enzymic properties of an alkaline chelator-resistant alpha-amylase from an alkaliphilic Bacillus sp isolate L1711 SO PROCESS BIOCHEMISTRY LA English DT Article DE alkaliphilic; Bacillus sp.; extracellular; alpha-amylase; chelator resistant; metal inhibition ID PURIFICATION; STRAIN; BINDING AB An alkaliphilic amylase producing bacterium, Bacillus sp. strain L1711, was selected from 13 soda lakes isolates. When grown at pH 10.5 and 37 degrees C, strain L1711 produced multiple forms of amylases in the culture broth. One of these, BAA, was purified from the culture supernatant by QAE column chromatography and preparative native gel electrophoresis. The molecular weight of BAA was determined to be 51 kDa by SDS gel electrophoresis. The pH optima for activity below and above 40 degrees C were 9.5-10.0 and 7.0-7.5, respectively. BAA was stable in the pH range 6-11 and was completely inactivated at 55 degrees C. Thermostability was not increased in the presence of Ca2+. The enzyme was strongly inhibited by Ca2+, Zn2+, Mg2+, Mn2+, Ba2+ and Cu2+, whereas the presence of Na+, Co2+ and EDTA (10 mM) enhanced enzymic activity. The K. and specific activity of BAA on soluble starch were 1.9 mg/ml and 18.5 U/mg, respectively. (c) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Marshall Space Flight Ctr, Biophys ES76, Huntsville, AL 35812 USA. Univ Alabama, Dept Mat Sci, Huntsville, AL 35899 USA. Univ Alabama, Struct Biol Lab, Huntsville, AL 35899 USA. Univ Alabama, Dept Biol Sci, Huntsville, AL 35899 USA. RP Pusey, ML (reprint author), NASA, Marshall Space Flight Ctr, Biophys ES76, SD46, Huntsville, AL 35812 USA. EM Marc.L.Pusey@nasa.gov NR 25 TC 19 Z9 21 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1359-5113 J9 PROCESS BIOCHEM JI Process Biochem. PD JUN PY 2005 VL 40 IS 7 BP 2401 EP 2408 DI 10.1016/j.procbio.2004.09.016 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Engineering, Chemical SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Engineering GA 914IT UT WOS:000228221800018 ER PT J AU Yungster, S Radhakrishnan, K AF Yungster, S Radhakrishnan, K TI Structure and stability of one-dimensional detonationsin ethylene-air mixtures SO SHOCK WAVES LA English DT Article; Proceedings Paper CT 24th International Symposium on Shock Waves CY JUL 11-16, 2004 CL Beijing, PEOPLES R CHINA DE pulsating detonations; computational fluid dynamics; unsteady combustion ID SHOCK-INDUCED COMBUSTION; OVERDRIVEN DETONATIONS; INSTABILITY; MECHANISM; KINETICS AB The propagation of one-dimensional detonations in ethylene-air mixtures is investigated numerically by solving the one-dimensional Euler equations with detailed finite-rate chemistry. The numerical method is based on a second-order spatially accurate total-variation-diminishing scheme and a point implicit, first-order-accurate, time marching algorithm. The ethylene-air combustion is modeled with a 20-species, 36-step reaction mechanism. A multi-level, dynamically adaptive grid is utilized, in order to resolve the structure of the detonation. Parametric studies over an equivalence ratio range of 0.5 <= phi <= 3 for different initial pressures and degrees of detonation overdrive demonstrate that the detonation is unstable for low degrees of overdrive, but the dynamics of wave propagation varies with fuel-air equivalence ratio. For equivalence ratios less than approximately 1.2 the detonation exhibits a short-period oscillatory mode, characterized by high-frequency, low-amplitude waves. Richer mixtures (phi > 1.2$) exhibit a low-frequency mode that includes large fluctuations in the detonation wave speed. At high degrees of overdrive, stable detonation wave propagation is obtained. A modified McVey-Toong short-period wave-interaction theory is in excellent agreement with the numerical simulations. C1 NASA, Glenn Res Ctr, Inst Computat Mech Propuls, Cleveland, OH 44142 USA. RP Yungster, S (reprint author), NASA, Glenn Res Ctr, Inst Computat Mech Propuls, Cleveland, OH 44142 USA. EM Shaye.Yungster@grc.nasa.gov NR 28 TC 9 Z9 9 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0938-1287 J9 SHOCK WAVES JI Shock Waves PD JUN PY 2005 VL 14 IS 1-2 BP 61 EP 72 DI 10.1007/s00193-005-0242-0 PG 12 WC Mechanics SC Mechanics GA 933LC UT WOS:000229628900009 ER PT J AU Goldstein, ML Eastwood, JP Treumann, RA Lucek, EA Pickett, J Decreau, P AF Goldstein, ML Eastwood, JP Treumann, RA Lucek, EA Pickett, J Decreau, P TI The near-earth solar wind SO SPACE SCIENCE REVIEWS LA English DT Review ID HELIOSPHERIC CURRENT SHEET; CORONAL MASS EJECTIONS; 4-POINT CLUSTER APPLICATION; COSMIC-RAY TRANSPORT; FIELD ANALYSIS TOOLS; MAGNETIC-FLUX ROPES; ALFVEN WAVES; SOLITARY WAVES; MAGNETOHYDRODYNAMIC FLUCTUATIONS; TANGENTIAL DISCONTINUITIES C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Max Planck Inst Extraterr Phys, D-37075 Garching, Germany. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London, England. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. CNRS, LPCE, F-75700 Paris, France. Univ Orleans, F-45067 Orleans, France. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Goldstein, Melvyn/B-1724-2008 NR 87 TC 9 Z9 9 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 JUN PY 2005 VL 118 IS 1-4 BP 7 EP 39 DI 10.1007/s11214-005-3823-4 PG 33 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 968LM UT WOS:000232164000001 ER PT J AU Eastwood, JP Lucek, EA Mazelle, C Meziane, K Narita, Y Pickett, J Treumann, RA AF Eastwood, JP Lucek, EA Mazelle, C Meziane, K Narita, Y Pickett, J Treumann, RA TI The foreshock SO SPACE SCIENCE REVIEWS LA English DT Review ID EARTHS BOW SHOCK; LOW-FREQUENCY WAVES; QUASI-PARALLEL SHOCKS; UPSTREAM SOLAR-WIND; PARTICLE INTERACTION UPSTREAM; SPECULARLY REFLECTED IONS; MONOCHROMATIC MHD WAVES; GYROPHASE-BUNCHED IONS; PLASMA REST FRAME; ULF WAVES C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London, England. CNRS, OMP, UPS, Ctr Etud Spatiale & Rayonnement, Toulouse, France. Univ New Brunswick, Dept Phys, Fredericton, NB E3B 5A3, Canada. Tech Univ Braunschweig, Inst Geophys & Extraterr Phys, D-3300 Braunschweig, Germany. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Max Planck Inst Extraterr Phys, D-37075 Garching, Germany. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 125 TC 92 Z9 92 U1 1 U2 7 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 JUN PY 2005 VL 118 IS 1-4 BP 41 EP 94 DI 10.1007/s11214-005-3824-3 PG 54 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 968LM UT WOS:000232164000002 ER PT J AU Lucek, EA Constantinescu, D Goldstein, ML Pickett, J Pincon, JL Sahraoui, F Treumann, RA Walker, SN AF Lucek, EA Constantinescu, D Goldstein, ML Pickett, J Pincon, JL Sahraoui, F Treumann, RA Walker, SN TI The magnetosheath SO SPACE SCIENCE REVIEWS LA English DT Review ID EARTHS BOW SHOCK; DRIFT-MIRROR INSTABILITY; LOW-FREQUENCY FLUCTUATIONS; PLASMA DEPLETION LAYER; SOLAR-WIND; LION ROARS; ELECTRIC-FIELD; SOLITARY WAVES; DAYSIDE MAGNETOPAUSE; CLUSTER OBSERVATIONS C1 Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London, England. Tech Univ Braunschweig, Inst Geophys & Extraterr Phys, D-3300 Braunschweig, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. CNRS, LPCE, F-45071 Orleans, France. IPSL, CETP, Velizy Villacoublay, France. Max Planck Inst Extraterr Phys, D-37075 Garching, Germany. Univ Sheffield, Sheffield, S Yorkshire, England. RP Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Prince Consort Rd, London, England. RI Constantinescu, Ovidiu Dragos/C-4350-2012; Goldstein, Melvyn/B-1724-2008; Constantinescu, Dragos/A-6007-2013 NR 104 TC 32 Z9 33 U1 2 U2 7 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 JUN PY 2005 VL 118 IS 1-4 BP 95 EP 152 DI 10.1007/s11214-005-3825-2 PG 58 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 968LM UT WOS:000232164000003 ER PT J AU A'Hearn, MF Belton, MJS Delamere, A Blume, WH AF A'Hearn, MF Belton, MJS Delamere, A Blume, WH TI Deep impact: A large-scale active experiment on a cometary nucleus SO SPACE SCIENCE REVIEWS LA English DT Review DE comets; space missions; solar system formation; craters; chemical composition ID BRIGHTNESS; DENSITY; ORIGIN; ICE AB The Deep Impact mission will provide the first data on the interior of a cometary nucleus and a comparison of those data with data on the surface. Two spacecraft, an impactor and a flyby spacecraft, will arrive at comet 9P/Tempel 1 on 4 July 2005 to create and observe the formation and final properties of a large crater that is predicted to be approximately 30-m deep with the dimensions of a football stadium. The flyby and impactor instruments will yield images and near infrared spectra (15 mu m) of the surface at unprecedented spatial resolutions both before and after the impact of a 350-kg spacecraft at 10.2 km/s. These data will provide unique information on the structure of the nucleus near the surface and its chemical composition. They will also used to interpret the evolutionary effects on remote sensing data and will indicate how those data can be used to better constrain conditions in the early solar system. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Belton Space Explorat Initiat LLC, Tucson, AZ USA. Delamere Support Serv, Boulder, CO USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP A'Hearn, MF (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM ma@astro.umd.edu NR 46 TC 40 Z9 40 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUN PY 2005 VL 117 IS 1-2 BP 1 EP 21 DI 10.1007/s11214-005-3387-3 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 942DW UT WOS:000230264100001 ER PT J AU Blume, WH AF Blume, WH TI Deep impact mission design SO SPACE SCIENCE REVIEWS LA English DT Review DE comets; space missions; mission design; 9P/Tempel 1 AB The Deep Impact mission is designed to provide the first opportunity to probe below the surface of a comet nucleus by a high-speed impact. This requires finding a suitable comet with launch and encounter conditions that allow a meaningful scientific experiment. The overall design requires the consideration of many factors ranging from environmental characteristics of the comet ( nucleus size, dust levels, etc.), to launch dates fitting within the NASA Discovery program opportunities, to launch vehicle capability for a large impactor, to the observational conditions for the two approaching spacecraft and for telescopes on Earth. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Blume, WH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 301-140L, Pasadena, CA 91109 USA. EM wblume@jpl.nasa.gov NR 8 TC 16 Z9 16 U1 0 U2 5 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUN PY 2005 VL 117 IS 1-2 BP 23 EP 42 DI 10.1007/s11214-005-3386-4 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 942DW UT WOS:000230264100002 ER PT J AU Hampton, DL Baer, JW Huisjen, MA Varner, CC Delamere, A Wellnitz, DD A'Hearn, MF Klaasen, KP AF Hampton, DL Baer, JW Huisjen, MA Varner, CC Delamere, A Wellnitz, DD A'Hearn, MF Klaasen, KP TI An overview of the instrument suite for the deep impact mission SO SPACE SCIENCE REVIEWS LA English DT Review DE comets; CCD cameras; IR spectrometer AB A suite of three optical instruments has been developed to observe Comet 9P/Tempel1, the impact of a dedicated impactor spacecraft, and the resulting crater formation for the Deep Impact mission. The high-resolution instrument (HRI) consists of an f/35 telescope with 10.5m focal length, and a combined filtered CCD camera and IR spectrometer. The medium-resolution instrument (MRI) consists of an f/17.5 telescope with a 2.1m focal length feeding a filtered CCD camera. The HRI and MRI are mounted on an instrument platform on the flyby spacecraft, along with the spacecraft star trackers and inertial reference unit. The third instrument is a simple unfiltered CCD camera with the same telescope as MRI, mounted within the impactor spacecraft. All three instruments use a Fairchild split-frame-transfer CCD with 1,024 x 1,024 active pixels. The IR spectrometer is a two-prism (CaF2 and ZnSe)imaging spectrometer imaged on a Rockwell HAWAII-1R HgCdTeMWIR array. The CCDs and IR FPA are read out and digitized to 14 bits by a set of dedicated instrument electronics, one set per instrument. Each electronics box is controlled by a radiation-hard TSC695F microprocessor. Software running on the microprocessor executes imaging commands from a sequence engine on the spacecraft. Commands and telemetry are transmitted via a MIL-STD-1553 interface, while image data are transmitted to the spacecraft via a low-voltage differential signaling (LVDS) interface standard. The instruments are used as the science instruments and are used for the optical navigation of both spacecraft. This paper presents an overview of the instrument suite designs, functionality, calibration and operational considerations. C1 Ball Aerosp & Technol Corp, Boulder, CO 80301 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hampton, DL (reprint author), Ball Aerosp & Technol Corp, POB 1062, Boulder, CO 80301 USA. EM dhampton@ball.com RI Wellnitz, Dennis/B-4080-2012 NR 7 TC 51 Z9 51 U1 1 U2 14 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUN PY 2005 VL 117 IS 1-2 BP 43 EP 93 DI 10.1007/s11214-005-3390-8 PG 51 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 942DW UT WOS:000230264100003 ER PT J AU Mastrodemos, N Kubitschek, DG Synnott, SP AF Mastrodemos, N Kubitschek, DG Synnott, SP TI Autonomous navigation for the deep impact mission encounter with comet Tempel 1 SO SPACE SCIENCE REVIEWS LA English DT Review DE autonomous navigation; Tempel 1; simulations AB The engineering goal of the Deep Impact mission is to impact comet Tempel 1 on July 4, 2005, with a 370 kg active Impactor spacecraft (s/c). The impact velocity will be just over 10 km/s and is expected to excavate a crater approximately 20m deep and 100m wide. The Impactor s/c will be delivered to the vicinity of Tempel 1 by the Flyby s/c, which is also the key observing platform for the event. Following Impactor release, the Flyby will change course to pass the nucleus at an altitude of 500 km and at the same time slow down in order to allow approximately 800s of observation of the impact event, ejecta plume expansion, and crater formation. Deep Impact will use the autonomous optical navigation (AutoNav) software system to guide the Impactor s/c to intercept the nucleus of Tempel 1 at a location that is illuminated and viewable from the Flyby. The Flyby s/c uses identical software to determine its comet-relative trajectory and provide the attitude determination and control system (ADCS) with the relative position information necessary to point the High Resolution Imager (HRI) and Medium Resolution Imager (MRI) instruments at the impact site during the encounter. This paper describes the Impactor s/c autonomous targeting design and the Flyby s/c autonomous tracking design, including image processing and navigation ( trajectory estimation and maneuver computation). We also discuss the analysis that led to the current design, the expected system performance as compared to the key mission requirements and the sensitivity to various s/c subsystems and Tempel 1 environmental factors. C1 CALTECH, Jet Prop Lab, Opt Navigat Grp, Navigat & Mission Design Sect, Pasadena, CA 91109 USA. RP Mastrodemos, N (reprint author), CALTECH, Jet Prop Lab, Opt Navigat Grp, Navigat & Mission Design Sect, 4800 Oak Grove Dr,M-S 301-150, Pasadena, CA 91109 USA. EM Nickolaos.Mastrodemos@jpl.nasa.gov NR 10 TC 20 Z9 22 U1 1 U2 7 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUN PY 2005 VL 117 IS 1-2 BP 95 EP 121 DI 10.1007/s11214-005-3394-4 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 942DW UT WOS:000230264100004 ER PT J AU Yeomans, DK Giorgini, JD Chesley, SR AF Yeomans, DK Giorgini, JD Chesley, SR TI The history and dynamics of comet 9P/Tempel 1 SO SPACE SCIENCE REVIEWS LA English DT Review DE comets; deep impact; space missions; 9P; Tempel 1; cometary dynamics ID COMETS AB Since its discovery in 1867, periodic comet 9P/Tempel 1 has been observed at 10 returns to perihelion, including all its returns since 1967. The observations for the seven apparitions beginning in 1967 have been fit with an orbit that includes only radial and transverse nongravitational accelerations that model the rocket-like thrusting introduced by the outgassing of the cometary nucleus. The successful nongravitational acceleration model did not assume any change in the comet's ability to outgas from one apparition to the next and the outgassing was assumed to reach a maximum at perihelion. The success of this model over the 1967-2003 interval suggests that the comet's spin axis is currently stable. Rough calculations suggest that the collision of the impactor released by the Deep Impact spacecraft will not provide a noticeable perturbation on the comet's orbit nor will any new vent that is opened as a result of the impact provide a noticeable change in the comet's nongravitational acceleration history. The observing geometries prior to, and during, the impact will allow extensive Earth based observations to complement the in situ observations from the impactor and flyby spacecraft. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yeomans, DK (reprint author), CALTECH, Jet Prop Lab, 301-150, Pasadena, CA 91109 USA. EM Donald.k.yeomans@jpl.nasa.gov NR 11 TC 18 Z9 18 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUN PY 2005 VL 117 IS 1-2 BP 123 EP 135 DI 10.1007/s11214-005-3392-6 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 942DW UT WOS:000230264100005 ER PT J AU Belton, MJ Meech, KJ A'Hearn, MF Groussin, O Mcfadden, L Lisse, C Fernandez, YR Pittichova, J Hsieh, H Kissel, J Klaasen, K Lamy, P Prialnik, D Sunshine, J Thomas, P Toth, I AF Belton, MJ Meech, KJ A'Hearn, MF Groussin, O Mcfadden, L Lisse, C Fernandez, YR Pittichova, J Hsieh, H Kissel, J Klaasen, K Lamy, P Prialnik, D Sunshine, J Thomas, P Toth, I TI Deep impact: Working properties for the target nucleus - Comet 9P/Tempel 1 SO SPACE SCIENCE REVIEWS LA English DT Review DE comets; space missions; nucleus; 9P/Tempel 1 ID INTERSTELLAR DUST ANALYZER; COMET HALLEY; DISTANT COMETS; P/WILD 2; PHOTOMETRY; STARDUST; DENSITY; SURFACE; SHOEMAKER-LEVY-9; DISTRIBUTIONS AB In 1998, Comet 9P/Tempel 1was chosen as the target of the Deep Impact mission ( A'Hearn, M. F., Belton, M. J. S., and Delamere, A., Space Sci. Rev., 2005) even though very little was known about its physical properties. Efforts were immediately begun to improve this situation by the Deep Impact Science Team leading to the founding of a worldwide observing campaign (Meech et al., Space Sci. Rev., 2005a). This campaign has already produced a great deal of information on the global properties of the comet's nucleus ( summarized in Table I) that is vital to the planning and the assessment of the chances of success at the impact and encounter. Since the mission was begun the successful encounters of the Deep Space 1 spacecraft at Comet 19P/Borrelly and the Stardust spacecraft at Comet 81P/Wild 2 have occurred yielding new information on the state of the nuclei of these two comets. This information, together with earlier results on the nucleus of comet 1P/Halley from the European Space Agency's Giotto, the Soviet Vega mission, and various ground-based observational and theoretical studies, is used as a basis for conjectures on the morphological, geological, mechanical, and compositional properties of the surface and subsurface that Deep Impact may find at 9P/Tempel 1. We adopt the following working values ( circa December 2004) for the nucleus parameters of prime importance to Deep Impact as follows: mean effective radius = 3.25 +/- 0.2 km, shape - irregular triaxial ellipsoid with a/b = 3.2 +/- 0.4 and overall dimensions of similar to 14.4 x 4.4 x 4.4 km, principal axis rotation with period = 41.85 +/- 0.1 hr, pole directions ( RA, Dec, J2000) = 46 +/- 10, 73 +/- 10 deg ( Pole 1) or 287 +/- 14, 16.5 +/- 10 deg ( Pole 2) ( the two poles are photometrically, but not geometrically, equivalent), Kron-Cousins (V-R) color = 0.56 +/- 0.02, V- band geometric albedo = 0.04 +/- 0.01, R-band geometric albedo = 0.05 +/- 0.01, R-band H( 1, 1, 0) = 14.441 +/- 0.067, and mass similar to 7 x 10(13) kg assuming a bulk density of 500 kg m(-3). As these are working values, i.e., based on preliminary analyses, it is expected that adjustments to their values may be made before encounter as improved estimates become available through further analysis of the large database being made available by the Deep Impact observing campaign. Given the parameters listed above the impact will occur in an environment where the local gravity is estimated at 0.027-0.04 cm s(-2) and the escape velocity between 1.4 and 2ms(-1). For both of the rotation poles found here, the Deep Impact spacecraft on approach to encounter will find the rotation axis close to the plane of the sky ( aspect angles 82.2 and 69.7 deg. for pole 1 and 2, respectively). However, until the rotation period estimate is substantially improved, it will remain uncertain whether the impactor will collide with the broadside or the ends of the nucleus. C1 Belton Space Explorat Initiat LLC, Tucson, AZ USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Maryland, College Pk, MD 20742 USA. Max Planck Inst Sonnensystemforsch, Katlenburg Lindau, Germany. Jet Prop Lab, Pasadena, CA USA. CNRS, Astron Spatiale Lab, F-13012 Marseille, France. Tel Aviv Univ, Dept Geophys & Planetary Sci, IL-69978 Tel Aviv, Israel. Sci Applicat Int Corp, Chantilly, VA USA. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. Konkoly Observ Budapest, Budapest, Hungary. RP Belton, MJ (reprint author), Belton Space Explorat Initiat LLC, Tucson, AZ USA. EM michaelbelton@beltonspace.com RI McFadden, Lucy-Ann/I-4902-2013; Lisse, Carey/B-7772-2016; OI McFadden, Lucy-Ann/0000-0002-0537-9975; Lisse, Carey/0000-0002-9548-1526; Fernandez, Yanga/0000-0003-1156-9721 NR 64 TC 35 Z9 35 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUN PY 2005 VL 117 IS 1-2 BP 137 EP 160 DI 10.1007/s11214-005-3389-1 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 942DW UT WOS:000230264100006 ER PT J AU Sunshine, JM A'Hearn, MF Groussin, O McFadden, LA Klaasen, KP Schultz, PH Lisse, CM AF Sunshine, JM A'Hearn, MF Groussin, O McFadden, LA Klaasen, KP Schultz, PH Lisse, CM TI Expectations for infrared spectroscopy of 9P/Tempel 1 from Deep Impact SO SPACE SCIENCE REVIEWS LA English DT Review DE coma; comets; Deep Impact; infrared spectroscopy; nucleus; Tempel 1 ID COMET HALE-BOPP; CENTAUR 8405 ASBOLUS; KUIPER-BELT OBJECTS; MU-M; DUST COMA; WATER ICE; SPECTRUM; SURFACE; NUCLEUS; HALLEY AB The science payload on the Deep Impact mission includes a 1.05-4.8 mu m infrared spectrometer with a spectral resolution ranging from R similar to 200-900. The Deep Impact IR spectrometer was designed to optimize, within engineering and cost constraints, observations of the dust, gas, and nucleus of 9P/Tempel 1. The wavelength range includes absorption and emission features from ices, silicates, organics, and many gases that are known to be, or anticipated to be, present on comets. The expected data will provide measurements at previously unseen spatial resolution before, during, and after our cratering experiment at the comet 9P/Tempel 1. This article explores the unique aspects of the Deep Impact IR spectrometer experiment, presents a range of expectations for spectral data of 9P/Tempel 1, and summarizes the specific science objectives at each phase of the mission. C1 Sci Applicat Int Corp, Chantilly, VA 22021 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. RP Sunshine, JM (reprint author), Sci Applicat Int Corp, Chantilly, VA 22021 USA. EM sunshinej@saic.com RI McFadden, Lucy-Ann/I-4902-2013; Lisse, Carey/B-7772-2016 OI McFadden, Lucy-Ann/0000-0002-0537-9975; Lisse, Carey/0000-0002-9548-1526 NR 72 TC 4 Z9 4 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUN PY 2005 VL 117 IS 1-2 BP 269 EP 295 DI 10.1007/s11214-005-3388-2 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 942DW UT WOS:000230264100011 ER PT J AU Klaasen, KP Carcich, B Carcich, G Grayzeck, EJ Mclaughlin, S AF Klaasen, KP Carcich, B Carcich, G Grayzeck, EJ Mclaughlin, S TI Deep impact: The anticipated flight data SO SPACE SCIENCE REVIEWS LA English DT Review DE Deep Impact; comet; Tempel 1; data set; calibration; data processing; data archive AB A comprehensive observational sequence using the Deep Impact (DI) spacecraft instruments (consisting of cameras with two different focal lengths and an infrared spectrometer) will yield data that will permit characterization of the nucleus and coma of comet Tempel 1, both before and after impact by the DI Impactor. Within the constraints of the mission system, the planned data return has been optimized. A subset of the most valuable data is planned for return in near-real time to ensure that the DI mission success criteria will be met even if the spacecraft should not survive the comet's closest approach. The remaining prime science data will be played back during the first day after the closest approach. The flight data set will include approach observations spanning the 60 days prior to encounter, pre-impact data to characterize the comet at high resolution just prior to impact, photos from the Impactor as it plunges toward the nucleus surface ( including resolutions exceeding 1 m), sub-second time sampling of the impact event itself from the Flyby spacecraft, monitoring of the crater formation process and ejecta outflow for over 10 min after impact, observations of the interior of the fully formed crater at spatial resolutions down to a few meters, and high-phase lookback observations of the nucleus and coma for 60 h after closest approach. An inflight calibration data set to accurately characterize the instruments' performance is also planned. A ground data processing pipeline is under development at Cornell University that will efficiently convert the raw flight data files into calibrated images and spectral maps as well as produce validated archival data sets for delivery to NASA's Planetary Data System within 6 months after the Earth receipt for use by researchers world-wide. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Cornell Univ, Ithaca, NY USA. Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, College Pk, MD 20742 USA. RP Klaasen, KP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM kenneth.p.klaasen@jpl.nasa.gov NR 1 TC 10 Z9 10 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUN PY 2005 VL 117 IS 1-2 BP 335 EP 372 DI 10.1007/s11214-005-3385-5 PG 38 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 942DW UT WOS:000230264100013 ER PT J AU Mcfadden, LA Rountree-Brown, MK Warner, EM Claughlin, SA Behne, JM Ristvey, JD Baird-Wilkerson, S Duncan, DK Gillam, SD Walker, GH Meech, KJ AF Mcfadden, LA Rountree-Brown, MK Warner, EM Claughlin, SA Behne, JM Ristvey, JD Baird-Wilkerson, S Duncan, DK Gillam, SD Walker, GH Meech, KJ TI Education and public outreach for nasa's Deep Impact mission SO SPACE SCIENCE REVIEWS LA English DT Review DE solar system exploration; education public outreach ID PROGRAM; SCIENCE AB The Deep Impact mission's Education and Public Outreach (E/PO) program brings the principles of physics relating to the properties of matter, motions and forces and transfer of energy to school-aged and public audiences. Materials and information on the project web site convey the excitement of the mission, the principles of the process of scientific inquiry and science in a personal and social perspective. Members of the E/PO team and project scientists and engineers, share their experiences in public presentations and via interviews on the web. Programs and opportunities to observe the comet before, during and after impact contribute scientific data to the mission and engage audiences in the mission, which is truly an experiment. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. McREL, Aurora, CO 80014 USA. Magnolia Consulting, Louisa, VA 23093 USA. Univ Colorado, Dept Astron, Fiske Planetarium, Boulder, CO 80309 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Amer Museum Nat Hist, New York, NY 10024 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Mcfadden, LA (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM mcfadden@astro.umd.edu RI McFadden, Lucy-Ann/I-4902-2013 OI McFadden, Lucy-Ann/0000-0002-0537-9975 NR 7 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JUN PY 2005 VL 117 IS 1-2 BP 373 EP 396 DI 10.1007/s11214-005-6062-9 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 942DW UT WOS:000230264100014 ER PT J AU Bandrivskyy, A Luchinsky, DG McClintock, PVE Smelyanskiy, VN Stefanovska, A AF Bandrivskyy, A Luchinsky, DG McClintock, PVE Smelyanskiy, VN Stefanovska, A TI Inference of systems with delay and applications to cardiovascular dynamics SO STOCHASTICS AND DYNAMICS LA English DT Article; Proceedings Paper CT Workshop on Stochastic Dynamics with Delay and Memory CY FEB 02-05, 2004 CL Halle, GERMANY SP ESF Project STOCHDYN DE stochastic delay equation; cardiovascular dynamics; Bayesian inference AB A Bayesian inference technique, able to encompass stochastic nonlinear systems, is described. It is applicable to differential equations with delay and enables values of model parameters, delay, and noise intensity to be inferred from measured time series. The procedure is demonstrated on a very simple one-dimensional model system, and then applied to inference of parameters in the Mackey-Glass model of the respiratory control system based on measurements of ventilation in a healthy subject. It is concluded that the technique offers a promising tool for investigating cardiovascular interactions. C1 Univ Lancaster, Dept Phys, Lancaster LA1 4YB, England. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Ljubljana, Fac Elect Engn, Ljubljana 1000, Slovenia. RP Bandrivskyy, A (reprint author), Univ Lancaster, Dept Phys, Lancaster LA1 4YB, England. EM a.bandrivskyy@gmx.net; d.luchinsky@lancaster.ac.uk; p.v.e.mcclintock@lancaster.ac.uk; Vadim.N.Smelyanskiy@nasa.gov; aneta@osc.fe.uni-lj.si RI Luchinsky, Dmitry/N-4177-2014 NR 13 TC 2 Z9 2 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0219-4937 J9 STOCH DYNAM JI Stoch. Dyn. PD JUN PY 2005 VL 5 IS 2 BP 321 EP 331 DI 10.1142/S0219493705001432 PG 11 WC Statistics & Probability SC Mathematics GA 960QT UT WOS:000231609000016 ER PT J AU Sobieszczanski-Sobieski, J Venter, G AF Sobieszczanski-Sobieski, J Venter, G TI Imparting desired attributes in structural design by means of multi-objective optimization SO STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 44th Structures, Structural Dynamics and Materials Conference CY APR 07-10, 2003 CL Norfolk, VA SP AIAA, ASME, ASCE, AHS, ASC DE optimization; design; structures; structural design; structural optimization; multi-disciplinary optimization ID PARETO FRONTIER AB Commonly available optimization methods typically produce a single optimal design as a constrained minimum of a particular objective function. However, in engineering design practice it is quite often important to explore as much of the design space as possible, with respect to many attributes, to discover what behaviors are possible and not possible within the initially adopted design concept. This paper shows that the very simple method of the sum of weighted objectives is useful for such exploration. By geometrical argument it is demonstrated that if every weighting coefficient is allowed to change its magnitude and its sign then the method returns a set of designs that are all feasible, diverse in their attributes, and include the Pareto and non-Pareto solutions, at least for convex cases. Numerical examples in the paper include the case of an aircraft wing structural box with thousands of degrees of freedom and constraints, and over 100 design variables, whose attributes are structural mass, volume, displacement, and frequency. The weighted coefficients method is inherently suitable for parallel, coarse-grained implementation that enables exploration of the design space in the elapsed time of a single structural optimization. C1 NASA, Computat Struct & Mat Branch, Res & Technol Directorate, Langley Res Ctr, Hampton, VA 23681 USA. Vanderplaats Res & Dev Inc, Colorado Springs, CO 80906 USA. RP Sobieszczanski-Sobieski, J (reprint author), NASA, Computat Struct & Mat Branch, Res & Technol Directorate, Langley Res Ctr, MS 155, Hampton, VA 23681 USA. EM j.sobieski@larc.nasa.gov; gventer@vrand.com OI Venter, Gerhard/0000-0001-9513-9774 NR 14 TC 5 Z9 6 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1615-147X J9 STRUCT MULTIDISCIP O JI Struct. Multidiscip. Optim. PD JUN PY 2005 VL 29 IS 6 BP 432 EP 444 DI 10.1007/s00158-004-0505-x PG 13 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics SC Computer Science; Engineering; Mechanics GA 931TY UT WOS:000229509600003 ER PT J AU Green, J Boykin, TB Farmer, CD Garcia, M Ironside, CN Klimeck, G Lake, R Stanley, CR AF Green, J Boykin, TB Farmer, CD Garcia, M Ironside, CN Klimeck, G Lake, R Stanley, CR TI Quantum cascade laser gain medium modeling using a second-nearest-neighbor sp(3)s* tight-binding model SO SUPERLATTICES AND MICROSTRUCTURES LA English DT Article DE quantum cascade laser; tight-binding; second-nearest-neighbor; intersubband; gas sensing; gas detection; antimonide ID MU-M; SEMICONDUCTOR; SUPERLATTICE; WAVELENGTH; SCATTERING AB A ten-band sp(3)s* second-nearest-neighbor tight-binding model has been used to model the electronic structure of various AI(x)Ga(1-x)As quantum cascade laser gain media. The results of the calculations have been compared with experimental emission wavelength data, and it has been shown that the model predicts the photon energies at the peaks in the gain coefficient spectra agreeing, on average, to within 4 meV of the experimental values. Comparison of the results of the calculations with results from a two-band (k) over right arrow . (p) over right arrow model shows that the tight-binding model is able to find the X-like states simultaneously with the &UGamma;-like states. These X-like states were found to be strongly localized within the barriers. Finally, the model has also been applied to InAs/AlSb and InAs/AlSb/GaSb QCLs. © 2005 Elsevier Ltd. All rights reserved. C1 Univ Glasgow, Dept Elect & Elect Engn, Glasgow G12 8LT, Lanark, Scotland. Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. Thales Res & Technol, F-91404 Orsay, France. Purdue Univ, Network Computat Nanotechnol, W Lafayette, IN 47907 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Riverside, Dept Elect Engn, Riverside, CA 92521 USA. RP Green, J (reprint author), Univ Glasgow, Dept Elect & Elect Engn, Oakfield Ave, Glasgow G12 8LT, Lanark, Scotland. EM qcl@jeremygreen.me.uk RI Ironside, Charles/G-8690-2011; Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 30 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0749-6036 J9 SUPERLATTICE MICROST JI Superlattices Microstruct. PD JUN PY 2005 VL 37 IS 6 BP 410 EP 424 DI 10.1016/j.spmi.2005.03.003 PG 15 WC Physics, Condensed Matter SC Physics GA 931VA UT WOS:000229512400007 ER PT J AU Bozzolo, G Garces, JE Smith, RJ AF Bozzolo, G Garces, JE Smith, RJ TI Atomistic modeling of Ag deposition on the low-index faces of Al and Al deposition on Ag SO SURFACE SCIENCE LA English DT Article DE adatoms; computer simulations; silver; aluminum; semi-empirical methods and model calculations; surface alloys; surface structure ID ELECTRONIC-STRUCTURE; 100 SURFACE; GROWTH; FILMS; ALUMINUM; METALS; PHASE; ENERGIES; AL(111); ALLOYS AB The deposition of Ag on low-index surfaces of Al, and the symmetric case of Al on Ag surfaces, are studied by means of a simple modeling approach based on a quantum approximate technique, the BFS method for alloys. For submonolayer deposits of Ag on Al, a preference is seen for growth of close-packed chains along nearest-neighbor directions on (100) and (110) surfaces, while cluster formation is preferred for growth on Al(111). For Al deposition on all three low-index Ag surfaces, diffusion of Al into the Ag surface layers is favored. The behavior seen on the various surfaces is attributed to a competition between the preference for Ag atoms to favor an Al environment, while Al atoms tend to avoid the increased energy associated with having Ag neighbors. The energies of the various atomic configurations are then determined by how the two competing effects manifest themselves for the corresponding geometric arrangements considered. (c) 2005 Elsevier B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. RP Bozzolo, G (reprint author), NASA, Glenn Res Ctr, MS 23-2, Cleveland, OH 44135 USA. EM guillermo.h.bozzolo@agrc.nasa.gov NR 31 TC 8 Z9 8 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 1 PY 2005 VL 583 IS 2-3 BP 229 EP 252 DI 10.1016/j.susc.2005.03.042 PG 24 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 933WU UT WOS:000229664400014 ER PT J AU DellaCorte, C AF DellaCorte, C TI Place your bets on this top ten SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM cdellacorte@stle.org NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 TRIBOL LUBR TECHNOL JI Tribol. Lubr. Technol. PD JUN PY 2005 VL 61 IS 6 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 928CP UT WOS:000229249000002 ER PT J AU Sirbuly, DJ Law, M Pauzauskie, P Yan, HQ Maslov, AV Knutsen, K Ning, CZ Saykally, RJ Yang, PD AF Sirbuly, DJ Law, M Pauzauskie, P Yan, HQ Maslov, AV Knutsen, K Ning, CZ Saykally, RJ Yang, PD TI Optical routing and sensing with nanowire assemblies SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE photonics; subwavelength; evanescent; nanoribbon; waveguide ID SUBWAVELENGTH-DIAMETER SILICA; WAVE-GUIDES; LIGHT; CELL; MICROSCOPY; DEVICES AB The manipulation of photons in structures smaller than the wavelength of light is central to the development of nanoscale integrated photonic systems for computing, communications, and sensing. We assemble small groups of freestanding, chemically synthesized nanoribbons and nanowires into model structures that illustrate how light is exchanged between subwavelength cavities made of three different semiconductors. The coupling strength of the optical linkages formed when nanowires are brought into contact depends both on their volume of interaction and angle of intersection. With simple coupling schemes, lasing nanowires can launch coherent pulses of light through ribbon waveguides that are up to a millimeter in length. Also, interwire coupling losses are low enough to allow light to propagate across several right-angle bends in a grid of crossed ribbons. The fraction of the guided wave traveling outside the wire/ribbon cavities is used to link nanowires through space and to separate colors within multiribbon networks. In addition, we find that nanoribbons function efficiently as waveguides in liquid media and provide a unique means for probing molecules in solution or in proximity to the waveguide surface. Our results lay the spadework for photonic devices based on assemblies of active and passive nanowire elements and presage the use of nanowire waveguides in microfluidics and biology. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Yang, PD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM p_yang@berkeley.edu RI Maslov, Alexey/E-5158-2011; Ning, C. Z./D-4699-2009; Pauzauskie, Peter/A-1316-2014 OI Maslov, Alexey/0000-0002-7835-2474; Ning, C. Z./0000-0003-4583-8889; NR 29 TC 151 Z9 153 U1 3 U2 64 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 MAY 31 PY 2005 VL 102 IS 22 BP 7800 EP 7805 DI 10.1073/pnas.0408641102 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 932CE UT WOS:000229531000006 PM 15911765 ER PT J AU Xu, TB Su, J AF Xu, TB Su, J TI Development, characterization, and theoretical evaluation of electroactive polymer-based micropump diaphragm SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article DE electroactive polymer (EAP); micropump diaphragm; actuation; displacement; volume rate; pumping speed ID POLY(VINYLIDENE FLUORIDE-TRIFLUOROETHYLENE) COPOLYMER; MEMS; PERFORMANCE; DESIGN; STRAIN AB A micropump diaphragm, based on the high energy electron irradiated poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)), an electroactive polymer (EAP), has been developed for air dynamic flow control. Its displacement stroke, profiles, and volume stroke rate (the volume change rate) have been characterized as a function of the electric field and the driving frequency. The displacement at the center of the diaphragm can reach 21 mu m at 106 V/mu m with the driving frequency of 10 Hz. The dispersion of the displacement is less than 30% for more than four frequency decades (0.1-1000 Hz). The characteristics of the electroactive polymer micropump diaphragm (EAPMPD) have also been theoretically evaluated. The volume rate of the EAPMPD can be 550 mu L/min at 80 V/mu m with the frequency of 1000 Hz. This study demonstrates that the volume rate of the diaphragm is high, and either the amplitude or the frequency of the applied electric field can tune it. In addition, when the performance of the diaphragm is modeled, the agreement between the theoretical results and the experimental data validates that the modeling provides an effective tool to guide EAPMPD design for an optimized performance. The results demonstrate that the diaphragm can be a candidate for aerospace applications to replace the traditional complex mechanical systems, increase the control capability, and reduce the weight for future air dynamic control systems. (c) 2005 Elsevier B.V. All rights reserved. C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Xu, TB (reprint author), Natl Inst Aerosp, 144 Res Dr, Hampton, VA 23666 USA. EM t.xu@larc.nasa.gov NR 25 TC 22 Z9 22 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-4247 J9 SENSOR ACTUAT A-PHYS JI Sens. Actuator A-Phys. PD MAY 31 PY 2005 VL 121 IS 1 BP 267 EP 274 DI 10.1016/j.sna.2005.01.020 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 933KM UT WOS:000229627300036 ER PT J AU Greenberg, JA Kefauver, SC Stimson, HC Yeaton, CJ Ustin, SL AF Greenberg, JA Kefauver, SC Stimson, HC Yeaton, CJ Ustin, SL TI Survival analysis of a neotropical rainforest using multitemporal satellite imagery SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE remote sensing; change detection; multitemporal; survival analysis; neotropical rainforests; deforestation; roads; Ecuador Parque National Yasuni ID LAND-COVER-CHANGE; DEFORESTATION; DYNAMICS; PATTERNS; SYSTEMS; MEXICO; RATES; ROADS AB We present results of an analysis of deforestation at a UNESCO Biosphere Reserve, the Parque National Yasuni, located in the rainforests of eastern Ecuador using multitemporal Landsat TM and ETM+ satellite imagery. Using survival analysis, we assessed both cut-rent and future trends in deforestation rates, and investigated the impact of spatial, cultural, and economic factors oil deforestation. These factors included the distance from roads, rivers, research facilities, oil facilities, markets and towns. and land ownership by colonists, native inhabitants, and an oil company. We found the annual rate of deforestation is currently only 0.11%, but that this rate is increasing with time and, assuming that the trend of increasing rate of forest loss continues, we would predict that by 2063, 50% of the forest within 2 kill of an oil access road will be lost to unhindered colonization and anthropogenic conversion. The Quechua colonists are associated with areas of the highest rate of deforestation, followed by the native Huaorani and the lowest region of deforestation was in areas Occupied by a local oil company. By far, the strongest predictor of where deforestation is predicted to occur was proximity to the road. Proximity to research sites, oil facilities, market, and rivers significantly decreases deforestation rates, and proximity to towns significantly increases deforestation rates. (c) 2005 Elsevier Inc. All rights reserved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Davis, Davis, CA 95616 USA. Smithsonian Inst, Conservat Res Ctr, Washington, DC 20560 USA. RP Greenberg, JA (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM jgreenberg@arc.nasa.gov OI Greenberg, Jonathan/0000-0001-8435-9077; Kefauver, Shawn/0000-0002-1687-1965 NR 31 TC 21 Z9 21 U1 0 U2 9 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 MAY 30 PY 2005 VL 96 IS 2 BP 202 EP 211 DI 10.1016/j.rse.2005.02.010 PG 10 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 942LV UT WOS:000230284800006 ER PT J AU Richmond, NC Hood, LL Mitchell, DL Lin, RP Acuna, H Binder, AB AF Richmond, NC Hood, LL Mitchell, DL Lin, RP Acuna, H Binder, AB TI Correlations between magnetic anomalies and surface geology antipodal to lunar impact basins SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID SOLAR-WIND; MOON; PROSPECTOR; FIELDS; HIGHLANDS; MERCURY; ORIGIN; SIDE AB [1] Previous work has shown that the strongest concentrations of lunar crustal magnetic anomalies are located antipodal to four large, similarly aged impact basins (Orientale, Serenitatis, Imbrium, and Crisium). Here, we report results of a correlation study between magnetic anomaly clusters and geology in areas antipodal to Imbrium, Orientale, and Crisium. Unusual geologic terranes, interpreted to be of seismic or ejecta origin associated with the antipodal basins, have been mapped antipodal to both Orientale and Imbrium. All three antipode regions have many high-albedo swirl markings. Results indicate that both of the unusual antipode terranes and Mare Ingenii ( antipodal to Imbrium) show a correlation with high-magnitude crustal magnetic anomalies. A statistical correlation between all geologic units and regions of medium to high magnetization when high-albedo features are present ( antipodal to Orientale) may suggest a deep, possibly seismic origin to the anomalies. However, previous studies have provided strong evidence that basin ejecta units are the most likely sources of lunar crustal anomalies, and there is currently insufficient evidence to differentiate between an ejecta or seismic origin for the antipodal anomalies. Results indicate a strong correlation between the high-albedo markings and regions of high magnetization for the Imbrium, Orientale, and Crisium antipodes. Combined with growing evidence for an Imbrian age to the magnetic anomalies, this supports a solar wind deflection origin for the lunar swirls. C1 Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92093 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lunar Res Inst, Tucson, AZ 85747 USA. RP Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, 9500 Gilman Dr, La Jolla, CA 92093 USA. EM nic@ucsd.edu NR 40 TC 27 Z9 30 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD MAY 28 PY 2005 VL 110 IS E5 AR E05011 DI 10.1029/2005JE002405 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 935JE UT WOS:000229776500003 ER PT J AU McPhee, MG Kwok, R Robins, R Coon, M AF McPhee, MG Kwok, R Robins, R Coon, M TI Upwelling of Arctic pycnocline associated with shear motion of sea ice SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HEAT-FLUX; OCEAN; EDDIES; MODEL; LAYER; POLE AB High-resolution radar imagery shows that the dynamic response of winter sea ice to gradients in large-scale surface wind stress is often localized along quasi-linear fractures hundreds of kilometers long. Relative shearing motion across these narrow fractures can exceed 10 cm s(-1). In one event recorded during the drift of the SHEBA ice camp, we observed an intense zone of pycnocline upwelling ( similar to 14 m) associated with significant shear motion near the camp, while upward turbulent heat flux in the ocean boundary layer reached nearly 400 W m(-2), an order of magnitude greater than at any other time during the year-long drift. We attribute the upwelling to Ekman pumping associated with concentrated ice shear. Over the entire Arctic Ocean sea ice cover, this process could be responsible for significant heat exchange between the cold surface layer and warmer subsurface water at the ubiquitous fractures resulting from large-scale atmosphere-ice interactions. C1 McPhee Res Co, Naches, WA 98937 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NW Res Associates Inc, Bellevue, WA 98009 USA. RP McPhee, MG (reprint author), McPhee Res Co, Naches, WA 98937 USA. EM max@nwra.com RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 16 TC 17 Z9 17 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 MAY 27 PY 2005 VL 32 IS 10 AR L10616 DI 10.1029/2004GL021819 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 935IP UT WOS:000229774800001 ER PT J AU Tsurutani, BT Guarnieri, FL Lakhina, GS Hada, T AF Tsurutani, BT Guarnieri, FL Lakhina, GS Hada, T TI Rapid evolution of magnetic decreases (MDs) and discontinuities in the solar wind: ACE and Cluster SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NONLINEAR ALFVEN WAVES; PONDEROMOTIVE FORCE; ULYSSES OBSERVATIONS; HOLES AB An experiment was conducted to identify and measure the same magnetic decreases (MDs) and interplanetary discontinuities at two different points in space separated by similar to 0.01 AU along the radial distance from the sun. The ACE and Cluster satellite data were used in this study. Solar wind speeds measured at Cluster were used to calculate the approximate ( earlier) times of arrival at ACE. The field component changes at both spacecraft were intercompared to ensure that the same discontinuities were detected. Out of 7 MDs/discontinuities selected, 6 were identified at ACE. The MDs/discontinuities were identified within 7 s to 35 s of the convection times. The MD thicknesses at Cluster were substantially smaller than at ACE. The ratio of thicknesses varied from 0.21 to 0.045. One possible interpretation of this observation is that the Alfven wave front ( rotational discontinuity) is steepening by a factor of greater than 15 per wavelength propagated. This may have important consequences for the generation of high frequency turbulence in interplanetary space. It is noted that the 6 discontinuities transited the similar to 0.01 AU distance from ACE to Cluster with essentially the solar wind convection speed. A possible mechanism contributing to this feature is discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Brazilian Inst Space Res, Sao Paulo, Brazil. Indian Inst Geomagnetism, Bombay 400005, Maharashtra, India. Kyoto Univ, Res Inst Sustainable Humanosphere, Uji, Kyoto, Japan. Kyushu Univ, Dept Earth Sci & Technol, Fukuoka 8168580, Japan. RP Tsurutani, BT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM bruce.tsurutani@jpl.nasa.gov RI Lakhina, Gurbax /C-9295-2012 NR 16 TC 4 Z9 4 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 MAY 27 PY 2005 VL 32 IS 10 AR L10103 DI 10.1029/2004GL022151 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 935IP UT WOS:000229774800002 ER PT J AU Anderson, JD Johnson, TV Schubert, G Asmar, S Jacobson, RA Johnston, D Lau, EL Lewis, G Moore, WB Taylor, A Thomas, PC Weinwurm, G AF Anderson, JD Johnson, TV Schubert, G Asmar, S Jacobson, RA Johnston, D Lau, EL Lewis, G Moore, WB Taylor, A Thomas, PC Weinwurm, G TI Amalthea's density is less than that of water SO SCIENCE LA English DT Article ID SMALL INNER SATELLITES; JUPITER; DISCOVERY; ORBITS AB Radio Doppler data from the Galileo spacecraft's encounter with Amalthea, one of Jupiter's small inner moons, on 5 November 2002 yield a mass of (2.08 +/- 0.15) x 10(18) kilograms. Images of Amalthea from two Voyager spacecraft in 1979 and Galileo imaging between November 1996 and June 1997 yield a volume of (2.43 +/- 0.22) x 10(6) cubic kilometers. The satellite thus has a density of 857 +/- 99 kilograms per cubic meter. We suggest that Amalthea is porous and composed of water ice, as well as rocky material, and thus formed in a cold region of the solar system, possibly not at its present location near Jupiter. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Cornell Univ, Ctr Radio Phys & Space Res, Ithaca, NY 14853 USA. Vienna Univ Technol, Inst Geodesy & Geophys, A-1040 Vienna, Austria. RP Anderson, JD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM john.d.anderson@jpl.nasa.gov NR 22 TC 42 Z9 42 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 MAY 27 PY 2005 VL 308 IS 5726 BP 1291 EP 1293 DI 10.1126/science.1110422 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 931JT UT WOS:000229482300041 PM 15919987 ER PT J AU Li, H Chen, BD AF Li, H Chen, BD TI The evolution of precipitable water associated with the Asian and Australian monsoons as revealed from MODIS/SSMI, ECMWF and NCEP reanalysis data sets SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VARIABILITY; ONSET AB By using MODIS/SSMI merged water vapor data, the evolution of total precipitable water (TPW) associated with the Asian and Australian monsoons has been studied. In addition to the satellite data, the monthly means of TPW data from the National Center for Environmental Prediction (NCEP) Reanalysis II and the European Centre for Medium-Range Weather Forecasts (ECMWF) 40-year Reanalysis (ERA-40) are used to compare with the merged TPW data. The large TPW is associated with the onsets of the Asian and Australian monsoons and shows a pronounced seasonal variability. Within northern Australia the annual mean TPW from the NCEP and SSMI/MODIS data sets show a decreasing trend over the last five years and the ERA-40 over the 2.5 years but no obvious trend can be found within southern Asia, indicating that the atmosphere tends to become "drier" over the Australian monsoon region. The result from available ERA-40 data set shows a quite similar feature with that of the merged TPW. However the NCEP TPW, which may be mostly influenced by the forecast model, particularly, by the performance of the physical parameterizations, has underestimated the TPW and has a rather unsystematic evolution in terms of seasonal migration. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Applicat Int Corp, San Diego, CA 92121 USA. RP Li, H (reprint author), Beijing Meteorol Bur, 44 Zizhuyuan Rd,Haidian Dist, Beijing 100089, Peoples R China. EM lh_2008@263.net NR 11 TC 4 Z9 4 U1 1 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 MAY 26 PY 2005 VL 32 IS 10 AR L10811 DI 10.1029/2005GL022570 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 935IO UT WOS:000229774700005 ER PT J AU Yizengaw, E Wei, H Moldwin, MB Galvan, D Mandrake, L Mannucci, A Pi, X AF Yizengaw, E Wei, H Moldwin, MB Galvan, D Mandrake, L Mannucci, A Pi, X TI The correlation between mid-latitude trough and the plasmapause SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TOTAL ELECTRON-CONTENT; F-LAYER; DYNAMICS AB We use simultaneous global observations of the mid-latitude trough and the plasmapause to experimentally prove a long-standing conjecture of magnetosphere-ionosphere coupling-namely the mid-latitude trough and plasmapause are on the same field line. Global Ionospheric Maps (GIM), generated using ground based GPS receivers, are used to detect the globally extended mid-latitude trough; while global IMAGE EUV pictures are used to estimate the plasmapause position. Observations during the equinox and solstices and during quiet and disturbed periods are analyzed. In addition, positions of the mid-latitude trough are calculated using a simple empirical model. The two independent observations (mid-latitude trough and plasmapause positions) and an empirical model have been compared on a global scale and found to be in excellent agreement. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yizengaw, E (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. EM ekassie@igpp.ucla.edu RI Mannucci, Anthony/A-1349-2007; Moldwin, Mark/F-8785-2011; Yizengaw, Endawoke/I-3471-2015 OI Mannucci, Anthony/0000-0003-2391-8490; Moldwin, Mark/0000-0003-0954-1770; Yizengaw, Endawoke/0000-0001-5772-3355 NR 15 TC 3 Z9 3 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 MAY 26 PY 2005 VL 32 IS 10 AR L10102 DI 10.1029/2005GL022954 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 935IO UT WOS:000229774700007 ER PT J AU Gurney, KR Chen, YH Maki, T Kawa, SR Andrews, A Zhu, ZX AF Gurney, KR Chen, YH Maki, T Kawa, SR Andrews, A Zhu, ZX TI Sensitivity of atmospheric CO2 inversions to seasonal and interannual variations in fossil fuel emissions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-DIOXIDE EMISSIONS; TRANSPORT; DELTA-C-13; MODELS; SINKS; CYCLE; LAND AB [1] Estimates of fossil fuel CO2 are a critical component in atmospheric CO2 inversions. Rather than solving for this portion of the atmospheric CO2 budget, inversions typically include estimates of fossil fuel CO2 as a known quantity. However, this assumption may not be appropriate, particularly as inversions continue to solve for fluxes at reduced space and timescales. In this study, two different alterations are made to widely used fossil fuel CO2 emissions estimates, and these altered emissions are run through a series of atmospheric inversion experiments. The first alteration is the inclusion of a seasonal cycle which depends upon both season and latitude. The other alteration is the inclusion of year-by-year changes in the spatial distribution of fossil fuel CO2 emissions. All but the interannual inversion experiments are run with three models from the TransCom 3 atmospheric inversion intercomparison. These three models span the key components of atmospheric transport and hence can be expected to capture the range of potential bias caused by assumed fossil fuel CO2 emission estimates when interacting with transport processes. Key findings include the lack of seasonal rectification of the seasonally varying fossil fuel CO2 emissions in the annual mean. Examination of monthly fluxes in the seasonal inversion, however, indicates that significant bias is likely occurring and may be as large as 50% of the residual flux during certain times of the year. In this study, interannual variations were little effected by shifts in the spatial pattern of fossil fuel CO2 emissions. However, as the spatial scale of inversions is reduced, potential bias will likely increase. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Japan Meteorol Agcy, Observat Dept, Div Atmospher Environm, Chiyoda Ku, Tokyo 1008122, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Gurney, KR (reprint author), Colorado State Univ, Dept Atmospher Sci, 1371 Campus Delivery, Ft Collins, CO 80523 USA. EM keving@atoms.colostate.edu RI Kawa, Stephan/E-9040-2012; Andrews, Arlyn/K-3427-2012 NR 33 TC 61 Z9 66 U1 2 U2 10 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 MAY 26 PY 2005 VL 110 IS D10 AR D10308 DI 10.1029/2004JD005373 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 935IT UT WOS:000229775200003 ER PT J AU Mayr, HG Mengel, JG AF Mayr, HG Mengel, JG TI Interannual variations of the diurnal tide in the mesosphere generated by the quasi-biennial oscillation SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DOPPLER-SPREAD PARAMETERIZATION; NUMERICAL SPECTRAL MODEL; WAVE MOMENTUM DEPOSITION; LARGE-SCALE DYNAMICS; ZONAL MEAN WINDS; GRAVITY-WAVE; LOWER THERMOSPHERE; MIDDLE ATMOSPHERE; EQUATORIAL OSCILLATIONS; PLANETARY-WAVES AB [ 1] We report results from a study with the numerical spectral model (NSM), which produces significant interannual variations in the diurnal tide. Applying Hines's Doppler spread parameterization, small-scale gravity waves (GWs) drive the quasi-biennial oscillation (QBO) and semiannual oscillation. With a GW source that peaks at the equator and is taken to be isotropic and independent of season, the NSM generates a QBO with variable periods around 26 months and zonal wind amplitudes close to 25 m s(-1) at 30 km. As reported earlier, the NSM reproduces the observed equinoctial maxima in the diurnal tide at altitudes around 95 km. In the present paper it is shown that the QBO also modulates the tide such that the seasonal amplitude maxima can vary from one year to another by as much as 30%. To shed light on the underlying mechanisms, the relative importance of the linearized advection terms is discussed, which involve the meridional and vertical winds of the diurnal tide. These interactions generate pronounced QBO modulations of the tide at altitudes below 50 km. In the mesosphere between 50 and 80 km the signature is not well defined because of interference from the seasonal variations. At altitudes above 80 km, however, the QBO-related interannual variations of the tide are again relatively large, but they are generated primarily by GW momentum deposition. Since the period of the QBO is variable and its phase is relative to the seasonal cycle changes, the magnitude of the QBO modulation of the tide in the upper mesosphere varies considerably as our long-term model simulation shows. This intermittency must be attributed to nonlinear interactions, and GW drag ( momentum deposition) is discussed as a potential candidate. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Mayr, HG (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 910-4, Greenbelt, MD 20771 USA. EM mayr@chapman.gsfc.nasa.gov NR 39 TC 24 Z9 24 U1 0 U2 0 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 MAY 26 PY 2005 VL 110 IS D10 AR D10111 DI 10.1029/2004JD005055 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 935IT UT WOS:000229775200001 ER PT J AU Kloepfer, JA Bradforth, SE Nadeau, JL AF Kloepfer, JA Bradforth, SE Nadeau, JL TI Photophysical properties of biologically compatible CdSe quantum dot structures SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SEMICONDUCTOR NANOCRYSTALS; SIZE SERIES; IN-VIVO; NANOPARTICLES; SPECTROSCOPY; LUMINESCENCE; DYNAMICS; PROTEIN; SURFACE; STABILITY AB The photophysical properties of CdSe and ZnS(CdSe) semiconductor quantum dots in nonpolar and aqueous solutions were examined with steady-state (absorption and emission) and time-resolved (time-correlated single-photon-counting) spectroscopy. The CdSe structures were prepared from a single CdSe synthesis, a portion of which were ZnS-capped, thus any differences observed in the spectral behavior between the two preparations were due to changes in the molecular shell. Quantum dots in nonpolar solvents were surrounded with a trioctylphosphine oxide (TOPO) coating from the initial synthesis solution. ZnS-capped CdSe were initially brighter than bare uncapped CdSe and had overall faster emission decays. The dynamics did not vary when the solvent was changed from hexane to dichloromethane; however, replacement of the TOPO cap by pyridine affected CdSe but not ZnS(CdSe). CdSe was then solubilized in water with mercapto-acetic acid or dihydrolipoic acid, whereas ZnS(CdSe) could be solubilized only with dihydrolipoic acid. Both solubilization agents quenched the nanocrystal emission, though with CdSe the quenching was nearly complete. Additional quenching of the remaining emission was observed when the redox-active molecule adenine was conjugated to the watersoluble CdSe but was not seen with ZnS(CdSe). The emission of aqueous CdSe could be enhanced under prolonged exposure to room light and resulted in a substantial increase of the emission lifetimes; however, the enhancement occurred concurrently with precipitation of the nanocrystals, which was possibly caused by photocatalytic destruction of the mercaptoacetic acid coating. These results are the first presented on aqueous CdSe quantum dot structures and are presented in the context of designing better, more stable biological probes. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ So Calif, Dept Chem, Los Angeles, CA 90089 USA. RP Nadeau, JL (reprint author), McGill Univ, Dept Biomed Engn, 3775 Univ St, Montreal, PQ H3A 2B4, Canada. EM jay.nadeau@mcgill.ca RI Bradforth, Stephen/B-5186-2008 OI Bradforth, Stephen/0000-0002-6164-3347 NR 44 TC 140 Z9 143 U1 1 U2 49 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD MAY 26 PY 2005 VL 109 IS 20 BP 9996 EP 10003 DI 10.1021/jp044581g PG 8 WC Chemistry, Physical SC Chemistry GA 928UG UT WOS:000229296600019 PM 16852208 ER PT J AU Artho, C Barringer, H Goldberg, A Havelund, K Khurshid, S Lowry, M Pasareanu, C Rosu, G Sen, K Visser, W Washington, R AF Artho, C Barringer, H Goldberg, A Havelund, K Khurshid, S Lowry, M Pasareanu, C Rosu, G Sen, K Visser, W Washington, R TI Combining test case generation and runtime verification SO THEORETICAL COMPUTER SCIENCE LA English DT Article DE automated testing; test case generation; model checking; symbolic execution; runtime verification; temporal logic; concurrency analysis; NASA rover controller ID MODEL CHECKING; PROGRAMS; MONITORS AB Software testing is typically an ad hoe process where human testers manually write test inputs and descriptions of expected test results, perhaps automating their execution in a regression suite. This process is cumbersome and costly. This paper reports results on a framework to further automate this process. The framework consists of combining automated test case generation based on systematically exploring the input domain of the program with runtime verification, where execution traces are monitored and verified against properties expressed in temporal logic. Capabilities also exist for analyzing traces for concurrency errors, such as deadlocks and data races. The input domain of the program is explored using a model checker extended with symbolic execution. Properties are formulated in an expressive temporal logic. A methodology is advocated that automatically generates properties specific to each input rather than formulating properties uniformly true for all inputs. The paper describes an application of the technology to a NASA rover controller. 2004 Published by Elsevier B.V. C1 ETH, Inst Comp Syst, CH-8092 Zurich, Switzerland. Univ Manchester, Sch Comp Sci, Manchester M13 9PL, Lancs, England. Univ Texas, UT ARISE, Austin, TX 78712 USA. NASA, Ames Res Ctr, Kestrel Technol, Moffett Field, CA 94035 USA. Univ Illinois, Dept Comp Sci, Urbana, IL 61801 USA. NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. EM havelund@kestreltechnology.com NR 68 TC 29 Z9 30 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3975 EI 1879-2294 J9 THEOR COMPUT SCI JI Theor. Comput. Sci. PD MAY 26 PY 2005 VL 336 IS 2-3 BP 209 EP 234 DI 10.1016/j.tcs.2004.11.007 PG 26 WC Computer Science, Theory & Methods SC Computer Science GA 930NK UT WOS:000229422700002 ER PT J AU Toth, RA AF Toth, RA TI Measurements of line positions and strengths of (HDO)-O-18 and (D2O)-O-18 in the 2500-4280 cm(-1) region SO JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE HDO and D2O infrared spectroscopy ID LONG PATH SPECTRA; D2O LOW-PRESSURE; TRANSITION FREQUENCIES; BANDS; HDO; STATES; NU(2)-BANDS; (H2O)-O-17; 2-NU-2; TRIAD AB Measurements of line positions and strengths of (D2O)-O-18 and (HDO)-O-18 were obtained with a Fourier transform spectrometer. The data were analyzed to obtain energy levels of the (100), (020), and (001) vibrational states of (HDO)-O-18 and the (001) and (011) states of (D2O)-O-18 and the vibrational bands of these states connected to the ground state covered the spectral region from 2500 to 4278 cm(-1). 456 absorption lines of (D2O)-O-18 and 856 lines of (HDO)-O-18 were assigned from the spectra. The measurements were of oxygen-18 enriched samples of deuterated water vapour and the spectra also contained features of (HDO)-O-16, (D2O)-O-16, (H2O)-O-16, (H2O)-O-17 and (H2O)-O-18 of which several were used as frequency calibration standards. © 2005 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Toth, RA (reprint author), CALTECH, Jet Prop Lab, MS 183-301, Pasadena, CA 91109 USA. EM toth@caesar.jpl.nasa.gov NR 15 TC 9 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2860 J9 J MOL STRUCT JI J. Mol. Struct. PD MAY 24 PY 2005 VL 742 IS 1-3 BP 49 EP 68 DI 10.1016/j.molstruc.2004.09.035 PG 20 WC Chemistry, Physical SC Chemistry GA 932AT UT WOS:000229527300007 ER PT J AU Tipping, RH Ma, Q Boulet, C Hartmann, JM AF Tipping, RH Ma, Q Boulet, C Hartmann, JM TI Theoretical analysis of the collision-induced electronic absorptions in O-2-N-2 and O-2-CO2 pairs SO JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE collision-induced absorption; molecular oxygen; atmospheric bands ID CONTINUUM ABSORPTION; MOLECULAR-OXYGEN; LOW-TEMPERATURES; GASEOUS OXYGEN; TRANSITIONS; SPECTRA; PRESSURES; O-2-O-2; ENHANCEMENT; N-2-O-2 AB Theoretical calculations are made for the collision-induced electronic absorption in the atmospheric infrared a&LARR; X (0,0) and visible b&LARR; X (0,0) bands of oxygen in O-2-N-2 and O-2-CO2 pairs. We consider only the long-range quadrupolar induction mechanism and use ab initio values for the quadrupole transition matrix elements that arise from spin-orbit mixing. By fitting the experimental value for the a&LARR; X (0,0) absorption in O-2-N-2, we obtain estimates for the isotropic and anisotropic polarizability electronic transition matrix elements of O-2. As a check, we then use these results together with other known data to calculate the corresponding absorption for O-2-CO2. We find good agreement, considering experimental error and theoretical approximations. We then estimate the corresponding absorption for the b&LARR; X (0,0) absorption in O-2-N-2. We discuss briefly the observed collision-induced absorption by O-2-O-2 pairs, and conclude that there must be other induction mechanisms involved for this system. Because of the importance of absorption by O-2 in the Earth's atmosphere, we conclude that a systematic study, including both additional measurements and theoretical analyses must be carried out before a satisfactory understanding can be attained. © 2005 Elsevier B.V. All rights reserved. C1 Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Columbia Univ, Dept Appl Phys, New York, NY 10025 USA. Goddard Space Flight Ctr, Inst Space Studies, New York, NY 10025 USA. Univ Paris 11, CNRS, Photophys Mol Lab, Ctr Orsay, F-91405 Orsay, France. RP Tipping, RH (reprint author), Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. EM rtipping@bama.ua.edu NR 30 TC 5 Z9 5 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2860 J9 J MOL STRUCT JI J. Mol. Struct. PD MAY 24 PY 2005 VL 742 IS 1-3 BP 83 EP 86 DI 10.1016/j.molstruc.2004.11.095 PG 4 WC Chemistry, Physical SC Chemistry GA 932AT UT WOS:000229527300010 ER PT J AU Mantz, AW Devi, VM Benner, DC Smith, MAH Predoi-Cross, A Dulick, M AF Mantz, AW Devi, VM Benner, DC Smith, MAH Predoi-Cross, A Dulick, M TI A multispectrum analysis of widths and shifts in the 2010-2260 cm(-1) region of C-12 O-16 broadened by Helium at temperatures between 80 and 297 K SO JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE carbon monoxide; Fourier transform infrared (FTIR) spectroscopy; He-pressure broadening and shifts; temperature dependences of widths and shifts ID PRESSURE-INDUCED LINESHIFTS; FUNDAMENTAL-BAND; LINE PARAMETERS; CARBON-MONOXIDE; CO; HE; (CO)-C-12-O-16; N-2; AR; O-2 AB Lorentz pressure-broadening and pressure-induced shift coefficients along with their temperature dependences have been determined for over forty P- and R-branch transitions in the fundamental band of (CO)-C-12-O-16 broadened with helium. A total of nineteen spectra recorded at various temperatures (+24 to -194 &DEG; C) in the 2010-2260 cm(-1) spectral region were analyzed simultaneously using a multispectrum nonlinear least squares fitting technique. The spectra were recorded with the McMath-Pierce Fourier transform spectrometer located at the National Solar Observatory on Kitt Peak. Present results are compared with similar measurements reported recently. © 2005 Elsevier B.V. All rights reserved. C1 Connecticut Coll, Dept Phys Astron & Geophys, New London, CT 06320 USA. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. Univ Lethbridge, Dept Phys, Lethbridge, AB T1K 3M4, Canada. Natl Opt Astron Observ, Natl Solar Observ, Tucson, AZ 85726 USA. RP Mantz, AW (reprint author), Connecticut Coll, Dept Phys Astron & Geophys, 270 Mohegan Ave, New London, CT 06320 USA. EM awman@conncoll.edu NR 25 TC 20 Z9 20 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2860 J9 J MOL STRUCT JI J. Mol. Struct. PD MAY 24 PY 2005 VL 742 IS 1-3 BP 99 EP 110 DI 10.1016/j.molstruc.2004.11.094 PG 12 WC Chemistry, Physical SC Chemistry GA 932AT UT WOS:000229527300013 ER PT J AU Brown, LR Benner, DC Devi, VM Smith, MAH Toth, RA AF Brown, LR Benner, DC Devi, VM Smith, MAH Toth, RA TI Line mixing in self- and foreign-broadened water vapor at 6 mu m SO JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE off-diagonal relaxation matrix elements; line mixing; H2O; foreign broadening; widths; shifts; self; air; H-2; He; CO2; N-2; O-2 ID Q-BRANCHES; NU(3) BAND; SPECTRA; CM(-1); PARAMETERS; NH3; STRENGTHS; PRESSURE; REGIONS; METHANE AB Line mixing has been measured for two pairs of transitions in the v(2) band of (H2O)-O-16. The rotational assignments of the four lines (in terms of the rotational quantum numbers J, K-a and K-c)are (a) two P branch lines: (1 0 1)<-(2 1 2) mixing with (2 1 2)<-(3 0 3) at 1539.061 and 1540.300 cm(-1), respectively; and (b) two R branch lines: (3 0 3)<-(2 1 2) mixing with (2 1 2)<-(1 0 1) at 1652.400 and 1653.267 cm(-1), respectively. Pressure broadening coefficients of H2O (halfwidths, pressure shifts and off-diagonal relaxation matrix elements) are reported for seven broadeners (self, H-2, He, CO2, N-2, O-2 and air) from retrievals performed by multispectrum fitting implemented with line mixing. The effect is largest for self- and H-2-broadening. (c) 2005 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Coll William & Mary, Williamsburg, VA 23187 USA. NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 183-601, Pasadena, CA 91109 USA. EM linda.brown@jpl.nasa.gov NR 34 TC 33 Z9 34 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2860 EI 1872-8014 J9 J MOL STRUCT JI J. Mol. Struct. PD MAY 24 PY 2005 VL 742 IS 1-3 BP 111 EP 122 DI 10.1016/j.molstruc.2004.12.059 PG 12 WC Chemistry, Physical SC Chemistry GA 932AT UT WOS:000229527300014 ER PT J AU Baker, J Centrella, J AF Baker, J Centrella, J TI Impact of LISA's low-frequency sensitivity on observations of massive black-hole mergers SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA ID GRAVITATIONAL-WAVE SIGNAL; COMPACT OBJECTS; BINARIES AB LISA will be able to detect gravitational waves from inspiralling massive black-hole (MBH) binaries out to redshifts z > 10. If the binary masses and luminosity distances can be extracted from the LISA data stream, this information can be used to reveal the merger history of MBH binaries and their host galaxies in the evolving universe. Since this parameter extraction generally requires that LISA observe the inspiral for a significant fraction of its yearly orbit, carrying out this programme requires adequate sensitivity at low frequencies, f < 10(-4) Hz. Using several candidate low-frequency sensitivities, we examine LISA's potential for characterizing M13H binary coalescences at redshifts z > 1. The results underscore the need for more detailed work towards understanding the potential scientific value of the lowfrequency part of LISA's sensitivity band. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Baker, J (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Joan.Centrella@NASA.gov NR 24 TC 2 Z9 2 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 MAY 21 PY 2005 VL 22 IS 10 SI SI BP S355 EP S362 DI 10.1088/0264-9381/22/10/029 PG 8 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100030 ER PT J AU Evans, JP AF Evans, JP TI Plan for compensation of self-gravity on ST-7/DRS SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA AB The Space Technology 7 (ST-7) payload, flying on the Laser Interferometer Space Antenna (LISA) Pathfinder (LPF) mission, will demonstrate drag-free control of a test mass with acceleration disturbances below 3 x 10(-14) M s(-2) Hz(-1/2) over a frequency range of 1 mHz to 30 mHz. Low-frequency acceleration noise introduced by the electrostatic force needed to counter static mass distribution imbalance is expected to be a significant contributor to the acceleration noise budget. For this reason, the self-gravity (due to mass imbalance) is minimized by adding trim mass to bring the total differential acceleration between the two test masses due to self-gravity below 5 x 10(-10) M s(-2) in any axis and the dc acceleration gradient due to self-gravity below 4 x 10(-8) M s(-2) m(-1) in any axis of either test mass. A plan has been established to develop the distribution and placement of the compensation masses. Compensation for the self-gravity effects on the two test masses is handled in a two-step process. A nominal compensation mass is defined and incorporated early and is located very near the test masses. The final trimming for self-gravity occurs after the integration on the spacecraft with small mass added externally to the test-mass vacuum enclosures. The plan identifies three preliminary points in the hardware maturity where the trimming to the asbuilt configuration can take place: (1) during build-up of the sensor vacuum enclosure, (2) prior to delivery of the integrated ST-7 to Europe and (3) prior to environmental testing of the integrated LPF system. The sensitivity of the self-gravity to knowledge errors in the actual mass distribution is taken into account in the determination of final trimming opportunities and mounting locations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Evans, JP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Jordan.P.Evans@jpl.nasa.gov NR 4 TC 3 Z9 3 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 MAY 21 PY 2005 VL 22 IS 10 SI SI BP S177 EP S183 DI 10.1088/0264-9381/22/10/007 PG 7 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100008 ER PT J AU Maghami, PG Hyde, TT Kim, J AF Maghami, PG Hyde, TT Kim, J TI An acquisition control for the laser interferometer space antenna SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA AB The Laser Interferometer Space Antenna mission is a planned gravitational wave detector consisting of three spacecraft in heliocentric orbit. Laser interferometry is used to measure distance fluctuations between test masses aboard each spacecraft to the picometre level over a 5 million km separation. The disturbance reduction system comprises the pointing and positioning control of the spacecraft, electrostatic suspension control of the test masses and point-ahead and acquisition control. This paper presents an approach for the acquisition control of the LISA formation. The approach establishes one link at a time. For each link, it defocuses the incoming beams to make its light detectable by the receiving spacecraft. Simulations are performed to demonstrate the feasibility of the proposed approach. C1 NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Div, Greenbelt, MD 20771 USA. Swales Aerosp Inc, Greenbelt, MD 20771 USA. RP Maghami, PG (reprint author), NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Div, Greenbelt, MD 20771 USA. NR 4 TC 5 Z9 5 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD MAY 21 PY 2005 VL 22 IS 10 SI SI BP S421 EP S428 DI 10.1088/0264-9381/22/10/038 PG 8 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100039 ER PT J AU McNamara, PW AF McNamara, PW TI Weak-light phase locking for LISA SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA ID LASER PHASE AB The long armlengths of the LISA interferometer, and the finite aperture of the telescope, lead to an optical power attenuation of similar to 10(-10) of the transmitted to received light. Simple reflection at the end of the arm is therefore not an optimum interferometric design. Instead, a local laser is offset phase locked to the weak incoming beam, transferring the phase information of the incoming to the outgoing light. This paper reports on an experiment to characterize a weak-light phase-locking scheme suitable for LISA in which a diode-pumped, Nd:YAG, non-planar ring oscillator (NPRO) is offset phase locked to a low-power (13 pW) frequency stabilized master NPRO. Preliminary results of the relative phase noise of the slave laser shows shot noise limited performance above 0.4 Hz. Excess noise is observed at lower frequencies, most probably due to thermal effects in the optical arrangement and phase-sensing electronics. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP McNamara, PW (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM paulm@milkyway.gsfc.nasa.gov NR 11 TC 10 Z9 11 U1 4 U2 6 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 MAY 21 PY 2005 VL 22 IS 10 SI SI BP S243 EP S247 DI 10.1088/0264-9381/22/10/016 PG 5 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100017 ER PT J AU Merkowitz, SM Ahmad, A Hyde, TT Sweetser, T Ziemer, J Conkey, S Kelly, W Shirgur, B AF Merkowitz, SM Ahmad, A Hyde, TT Sweetser, T Ziemer, J Conkey, S Kelly, W Shirgur, B TI LISA propulsion module separation study SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA AB The Laser Interferometer Space Antenna (LISA) mission is a space-borne gravitational wave detector consisting of three sciencecraft in heliocentric orbit. Each sciencecraft is delivered to its operational orbit by a propulsion module. Because of the strict thermal and mass balancing requirements of LISA, the baseline mission concept requires that the propulsion module separate from the sciencecraft after delivery. The only propulsion system currently included in the sciencecraft design are micronewton level thrusters, such as field emission electric propulsion (FEEP) or colloid thrusters, that are used to balance the 30-40 mu N of solar radiation pressure and provide the drag-free and attitude control of the sciencecraft. Due to these thrusters' limited authority, the separation of the propulsion module from the sciencecraft must be well controlled to not induce a large tip-off rotation of the sciencecraft. We present here the results of a study of the propulsion module separation system requirements that are necessary to safely deliver the three LISA sciencecraft to their final operational orbits. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Swales Aerosp, Beltsville, MD 20705 USA. RP Merkowitz, SM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Merkowitz, Stephen/D-6680-2012 OI Merkowitz, Stephen/0000-0002-0412-4209 NR 5 TC 2 Z9 2 U1 0 U2 3 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 MAY 21 PY 2005 VL 22 IS 10 SI SI BP S413 EP S419 DI 10.1088/0264-9381/22/10/037 PG 7 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100038 ER PT J AU Merkowitz, SM Haile, WB Conkey, S Kelly, W Peabody, H AF Merkowitz, SM Haile, WB Conkey, S Kelly, W Peabody, H TI Self-gravity modelling for LISA SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA AB The Laser Interferometer Space Antenna (LISA) mission, a space-based gravitational wave detector, uses laser metrology to measure distance fluctuations between proof masses aboard three sciencecraft. The total acceleration disturbance to each proof mass is required to be below 3 x 10(-15)ms(-2) Hz(-1/2) at 0. 1 mHz. Self-gravity noise due to sciencecraft distortion and motion is expected to be a significant contributor to the acceleration noise budget. To minimize these effects, the gravitational field at each proof mass must be kept as small, flat and constant as possible. It is estimated that the static (non-fluctuating) self-gravity acceleration must be kept below 5 x 10(-10) m s(-2) with a gradient below 3 x 10(-8) s(-2) in order to meet the required noise levels. Most likely it will not be possible to directly verify that the LISA sciencecraft meets these requirements by measurements; they must be verified by models. The LISA integrated modelling team developed a new self-gravity tool that calculates the gravitational forces and moments on the proof masses to aid in the design and verification of the LISA sciencecraft. We present here an overview of the tool and the latest self-gravity results calculated using the current baseline design of LISA. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Swales Aerosp, Beltsville, MD 20705 USA. RP Merkowitz, SM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Merkowitz, Stephen/D-6680-2012 OI Merkowitz, Stephen/0000-0002-0412-4209 NR 12 TC 5 Z9 5 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 MAY 21 PY 2005 VL 22 IS 10 SI SI BP S395 EP S402 DI 10.1088/0264-9381/22/10/035 PG 8 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100036 ER PT J AU Peabody, H Merkowitz, S AF Peabody, H Merkowitz, S TI LISA thermal design SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA AB The Laser Interferometer Space Antenna (LISA) mission, a space-based gravitational wave detector, uses laser metrology to measure distance fluctuations between proof masses aboard three spacecraft. The total acceleration disturbance to each proof mass is required to be below 3 x 10(-15) m s(-2) Hz(- 1/2) at 0.1 mHz. Optical path length variations on each optical bench must be kept below about 40 pm Hz(-1/2) over 1-100 mHz. Noise due to spacecraft thermal distortions, temperature difference variations across the proof mass housing and other thermal effects are expected to be significant contributors to these noise budgets. The LISA Integrated Modelling team developed a detailed thermal model that is currently being used. to drive the design of LISA. Several new thermal analysis techniques are also being developed in order to achieve model accuracies to LISA levels. We present here an overview of the LISA thermal design and modelling efforts. The latest thermal results calculated using the current baseline design of LISA are also discussed. C1 Swales Aerosp Inc, Beltsville, MD 20705 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Peabody, H (reprint author), Swales Aerosp Inc, 5050 Powder Mill Rd, Beltsville, MD 20705 USA. RI Merkowitz, Stephen/D-6680-2012 OI Merkowitz, Stephen/0000-0002-0412-4209 NR 5 TC 7 Z9 7 U1 1 U2 4 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 MAY 21 PY 2005 VL 22 IS 10 SI SI BP S403 EP S411 DI 10.1088/0264-9381/22/10/036 PG 9 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100037 ER PT J AU Sheard, BS Gray, MB Shaddock, DA McClelland, DE AF Sheard, BS Gray, MB Shaddock, DA McClelland, DE TI Laser frequency noise suppression by arm-locking in LISA: progress towards a bench-top demonstration SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA ID STABILIZATION AB Overcoming laser frequency noise is a significant technical challenge for achieving the design sensitivity of the Laser Interferometer Space Antenna (LISA) gravitational wave detector. Arm-locking is a recently proposed technique for suppressing frequency noise in LISA and can be used in addition to the established techniques of pre-stabilization and time-delay interferometry. Incorporation of arm-locking into LISA could provide many benefits, however experimental verification and testing is needed. We present the progress of an experimental test of arm-locking which uses 10 km of optical fibre to generate a large propagation time delay, analogous to the propagation delay in LISA. C1 Australian Natl Univ, Fac Sci, Dept Phys, Ctr Gravitat Phys, Canberra, ACT 0200, Australia. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Australian Natl Univ, Fac Sci, Dept Phys, Ctr Gravitat Phys, Canberra, ACT 0200, Australia. EM ben.sheard@anu.edu.au RI McClelland, David/E-6765-2010; Shaddock, Daniel/A-7534-2011 OI McClelland, David/0000-0001-6210-5842; Shaddock, Daniel/0000-0002-6885-3494 NR 13 TC 9 Z9 9 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 MAY 21 PY 2005 VL 22 IS 10 SI SI BP S221 EP S226 DI 10.1088/0264-9381/22/10/013 PG 6 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100014 ER PT J AU Sweetser, TH AF Sweetser, TH TI An end-to-end trajectory description of the LISA mission SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA AB The Laser Interferometer Space Antenna (LISA) mission is planned to measure gravitational waves by using a constellation of three spacecraft which stay at the points of an equilateral triangle revolving around the Sun for a period of at least five and up to 8.5 years. This mission description tells how the spacecraft are launched together and then separately transferred to their constellation positions using chemical propulsion to perform manoeuvres along the way. The paper further gives characteristics of the operational orbits (contrary to common perception, for example, the LISA configuration has no net rotation in inertial space), and discusses navigation and the effects of errors in the delivery to the constellation. The particular mission described here is the LISA Baseline 1 mission, which is based on operational orbits that minimize the average rate of change of the lengths of the arms of the triangular constellation over the five-year nominal mission. The launch period for mission described here is in December 2010, which is earlier than the launch period that will actually be used by the LISA project, so this mission must be considered only as characteristic of the mission architecture and not as a final plan. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sweetser, TH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 8 Z9 9 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD MAY 21 PY 2005 VL 22 IS 10 SI SI BP S429 EP S435 DI 10.1088/0264-9381/22/10/039 PG 7 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100040 ER PT J AU Tinto, M Larson, SL AF Tinto, M Larson, SL TI The LISA zero-signal solution SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 5th International LISA Symposium/38th ESLAB Symposium CY JUL 12-15, 2004 CL European Space & Technol Ctr, ESA, Noordwijk, NETHERLANDS HO European Space & Technol Ctr, ESA AB We derive a time-delay interferometric (TDI) combination that has zero-response to a gravitational wave signal. This combination, which we have called the zero-signal solution, is a two-parameter family of linear combinations of the generators of the TDI space that has null gravitational wave response when its two parameters coincide with the values of the angles of the source location in the sky. Remarkably, the zero-signal solution does not rely on any assumptions about the gravitational waveform, and in fact it works for waveforms of any kind. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Penn State Univ, Ctr Gravitat Wave Phys, Dept Phys, Davey Lab 104, University Pk, PA 16802 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 169-327, Pasadena, CA 91109 USA. EM Massimo.Tinto@jpl.nasa.gov; shane@gravity.psu.edu RI Larson, Shane/E-8576-2010 NR 7 TC 4 Z9 4 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 MAY 21 PY 2005 VL 22 IS 10 SI SI BP S531 EP S535 DI 10.1088/0264-9381/22/10/054 PG 5 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 941QU UT WOS:000230230100055 ER PT J AU Zhou, DK Smith, WL Liu, X Li, J Larar, AM Mango, SA AF Zhou, DK Smith, WL Liu, X Li, J Larar, AM Mango, SA TI Tropospheric CO observed with the NAST-I retrieval methodology, analyses, and first results SO APPLIED OPTICS LA English DT Article ID CARBON-MONOXIDE; ATMOSPHERIC-TEMPERATURE; SATELLITE; PROFILES; ALGORITHM; AIRCRAFT; SOUNDER AB High-resolution infrared spectra from aircraft and space-based observations contain information about tropospheric carbon monoxide (CO) as well as other trace species. A methodology for retrieving tropospheric CO from such remotely sensed spectral data has been developed for the National Polar-Orbiting Operational Environmental Satellite System's Airborne Sounder Testbed-Interferometer (NAST-I). CO profiles of the troposphere, together with its thermodynamic properties, are determined by use of a three-stage retrieval approach that combines the algorithms of physically based statistical eigenvector regression, simultaneous and iterative matrix inversion, and single-variable error-minimization CO profile matrix inverse retrieval. The NAST-I is collecting data while it is aboard high-altitude aircraft throughout many field campaigns. Detailed retrieval analyses based on the NAST-I instrument system along with retrieval results from several recent field campaigns are presented to demonstrate NAST-I CO retrieval capability. (c) 2005 Optical Society of America. C1 NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. Univ Wisconsin, Ctr Space Sci & Engn, Madison, WI 53706 USA. Natl Polar Orbiting Operat Environm Satellite Sys, Integrated Program Off, Silver Spring, MD 20910 USA. RP Zhou, DK (reprint author), NASA, Langley Res Ctr, Sci Directorate, 21 Langley Blvd, Hampton, VA 23681 USA. EM daniel.k.zhou@nasa.gov RI Li, Jun/H-3579-2015 OI Li, Jun/0000-0001-5504-9627 NR 34 TC 7 Z9 7 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 MAY 20 PY 2005 VL 44 IS 15 BP 3032 EP 3044 DI 10.1364/AO.44.003032 PG 13 WC Optics SC Optics GA 928NK UT WOS:000229278300019 PM 15929295 ER PT J AU Nishikawa, KI Richardson, G Koide, S Shibata, K Kudoh, T Hardee, P Fishman, GJ AF Nishikawa, KI Richardson, G Koide, S Shibata, K Kudoh, T Hardee, P Fishman, GJ TI A general relativistic magnetohydrodynamic simulation of jet formation SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; galaxies : active; galaxies : jets; MHD ID ACCRETION-EJECTION INSTABILITY; BLACK-HOLE ACCRETION; MAGNETICALLY DRIVEN ACCRETION; ACTIVE GALACTIC NUCLEI; MAGNETIZED DISKS; MICROQUASAR GRS-1915+105; NUMERICAL SIMULATIONS; PLUNGING REGION; 3 DIMENSIONS; IRON LINES AB We have performed a fully three- dimensional general relativistic magnetohydrodynamic ( GRMHD) simulation of jet formation from a thin accretion disk around a Schwarzschild black hole with a free- falling corona. The initial simulation results show that a bipolar jet ( velocity similar to 0: 3c) is created, as shown by previous two- dimensional axisymmetric simulations with mirror symmetry at the equator. The three- dimensional simulation ran over 100 light crossing time units (T-S = r(S) / c, where rS = 2GM/c(2)), which is considerably longer than the previous simulations. We show that the jet is initially formed as predicted owing in part to magnetic pressure from the twisting of the initially uniform magnetic field and from gas pressure associated with shock formation in the region around r = 3r(S). At later times, the accretion disk becomes thick and the jet fades resulting in a wind that is ejected from the surface of the thickened ( torus- like) disk. It should be noted that no streaming matter from a donor is included at the outer boundary in the simulation ( an isolated black hole not binary black hole). The wind flows outward with a wider angle than the initial jet. The widening of the jet is consistent with the outward- moving torsional Alfven waves. This evolution of disk- jet coupling suggests that the jet fades with a thickened accretion disk because of the lack of streaming material from an accompanying star. C1 Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. Univ Alabama, Dept Aerosp Engn & Mech, Huntsville, AL 35899 USA. Toyama Univ, Fac Engn, Toyama 9308555, Japan. Kyoto Univ, Kwasan Observ, Kyoto 6078417, Japan. Kyoto Univ, Hida Observ, Kyoto 6078417, Japan. Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. RP Natl Space Sci & Technol Ctr, 320 Sparkman Dr,SD 50, Huntsville, AL 35805 USA. EM ken-ichi.nishikawa@nsstc.nasa.gov NR 77 TC 36 Z9 36 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 MAY 20 PY 2005 VL 625 IS 1 BP 60 EP 71 DI 10.1086/429360 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 925IK UT WOS:000229046600006 ER PT J AU Kargaltsev, OY Pavlov, GG Zavlin, VE Romani, RW AF Kargaltsev, OY Pavlov, GG Zavlin, VE Romani, RW TI Ultraviolet, X-ray, and optical radiation from the geminga pulsar SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : individual (Geminga); stars : neutron; ultraviolet : stars ID NEUTRON-STAR ATMOSPHERES; HIGH-ENERGY; MODEL ATMOSPHERES; THERMAL-RADIATION; RADIO PULSAR; EMISSION; SCATTERING; VELA; RX-J1856.5-3754; IDENTIFICATION AB We observed the γ-ray pulsar Geminga with the FUV-MAMA and NUV-MAMA detectors of the Space Telescope Imaging Spectrometer to measure Geminga's spectrum and pulsations in the ultraviolet. The slope of the far-ultraviolet (FUV) spectrum is close to that of a Rayleigh-Jeans spectrum, suggesting that the FUV radiation is dominated by thermal emission from the neutron star (NS) surface. The measured FUV flux, F-FUV = (3.7 &PLUSMN; 0.2) x 10(-15) ergs cm(-2) s(-1) in the 1155-1702 &ANGS; band, corresponds to a brightness temperature T-RJ &AP; (0.3-0.4)(d(200)/R-13)(2) MK, depending on the interstellar extinction (d = 200d(200) pc and R = 13R(13) km are the distance and the NS radius, respectively). The soft thermal component of Geminga's X-ray spectrum measured with the XMM-Newton observatory corresponds to a temperature T-s = 0.49 &PLUSMN; 0.01 MK and radius R-s = (12.9 &PLUSMN; 1.0)d(200) km. Contrary to other NSs detected in the UV-optical, for which the extrapolation of the X-ray thermal component into the optical underpredicts the observed flux of thermal radiation, the FUV spectrum of Geminga lies slightly below the extrapolation of the soft thermal component, which might be associated with Geminga's very low temperature. Surprisingly, the thermal FUV radiation is strongly pulsed, showing a narrow dip at a phase close to that of a broader minimum of the soft X-ray light curve. The strong pulsations might be attributed to partial occultations of the thermal UV radiation by regions of the magnetosphere filled with electron/positron plasma. In contrast to the FUV spectrum, the near-infrared (NIR) through near-ultraviolet (NUV) spectrum of Geminga is clearly nonthermal. It can be described by a power-law model, F-v &PROP; v(-&UGamma;+1), with a photon index &UGamma; = 1.43 &PLUSMN; 0.15, close to the slope &UGamma; = 1.56 &PLUSMN; 0.24 of the hard X-ray (E > 2.5 keV) magnetospheric component. The extrapolation of the X-ray magnetospheric spectrum into the optical is marginally consistent with (or perhaps lies slightly above) the observed NIR-optical-NUV spectrum. The NUV pulsations, however, do not show a clear correlation with the hard X-ray pulsations. C1 Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RP Kargaltsev, OY (reprint author), Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. EM green@astro.psu.edu; pavlov@astro.psu.edu; vyacheslav.zavlin@msfc.nasa.gov; rwr@astro.stanford.edu NR 78 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 MAY 20 PY 2005 VL 625 IS 1 BP 307 EP 323 DI 10.1086/429368 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 925IK UT WOS:000229046600028 ER PT J AU Sterling, NC Dinerstein, HL Bowers, CW Redfield, S AF Sterling, NC Dinerstein, HL Bowers, CW Redfield, S TI The FUSE spectrum of the planetary nebula SWST 1: Evidence for inhomogeneities in the gas and dust SO ASTROPHYSICAL JOURNAL LA English DT Review DE dust, extinction; nuclear reactions, nucleosynthesis, abundances; planetary nebulae : general; planetary nebulae : individual (SwSt 1); stars : AGB and post-AGB; ultraviolet : ISM ID RESONANCE-ABSORPTION LINES; ASYMPTOTIC GIANT BRANCH; ULTRAVIOLET-SPECTROSCOPIC-EXPLORER; INFRARED EMISSION-LINES; ROTATING AGB STARS; MOLECULAR-HYDROGEN; ATOMIC-DATA; FE-III; GASEOUS NEBULAE; PHOTODISSOCIATION REGIONS AB We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the young, compact planetary nebula (PN) SwSt 1 along the line of sight to its central star HD 167362. We detect circumstellar absorption lines from several species against the continuum of the central star. The physical parameters of the nebula derived from the FUSE data differ significantly from those found from emission lines. We derive an electron density n(e) = 8800(-2400)(+4800) cm(-3) from the column density ratio of the excited S III fine-structure levels, which is at least a factor of 3 lower than all prior estimates. The gaseous iron abundance derived from the UV lines is quite high ([Fe/S] = -0.35 +/- 0.12), which implies that iron is not significantly depleted into dust. In contrast, optical and near-infrared emission lines indicate that Fe is more strongly depleted: [Fe/H] = -1.64 +/- 0.24 and [Fe/S] = -1.15 +/- 0.33. We do not detect nebular H-2 absorption, to a limit N(H-2) < 7 x 10(14) cm(-2), at least 4 orders of magnitude lower than the column density estimated from infrared H2 emission lines. Taken together, the lack of H2 absorption, low ne, and high gaseous Fe abundance derived from the FUSE spectrum provide strong evidence that dense structures (which can shield molecules and dust from the destructive effects of energetic stellar photons) are not present along the line of sight to the central star. On the other hand, there is substantial evidence for dust, molecular material, and dense gas elsewhere in SwSt 1. Therefore, we conclude that the nebula must have an inhomogeneous structure. We detect nebular absorption at 1040.94 and 1041.69 angstrom from the two excited fine-structure levels of neutral oxygen. These levels give rise to far-infrared emission lines at 63 and 145 mu m, which are often used to infer gas properties, particularly temperature, under the assumption that they are collisionally excited. We find that the O I fine-structure levels in SwSt 1 have an inverted population ratio. This requires a nonthermal excitation mechanism, which we identify as fluorescent excitation by the stellar continuum. To the extent that fluorescence affects the level populations, the far-infrared [O I] line strengths cannot be directly used as diagnostics of density and temperature. C1 Univ Texas, Dept Astron, Austin, TX 78712 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Univ Texas, Dept Astron, 1 Univ Stn,C1400, Austin, TX 78712 USA. EM sterling@astro.as.utexas.edu; harriet@astro.as.utexas.edu; bowers@stis.gsfc.nasa.gov; sredfield@astro.as.utexas.edu OI Redfield, Seth/0000-0003-3786-3486 NR 116 TC 16 Z9 16 U1 0 U2 1 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 MAY 20 PY 2005 VL 625 IS 1 BP 368 EP 384 DI 10.1086/429613 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 925IK UT WOS:000229046600032 ER PT J AU Lara, A Gopalswamy, N Caballero-Lopez, RA Yashiro, S Xie, H Valdes-Galicia, JF AF Lara, A Gopalswamy, N Caballero-Lopez, RA Yashiro, S Xie, H Valdes-Galicia, JF TI Coronal mass ejections and galactic cosmic-ray modulation SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic rays; sun : coronal mass ejections (CMEs) ID LONG-TERM MODULATION; MAGNETIC-FIELD; SOLAR MINIMUM; VOYAGER-2 OBSERVATIONS; INTERACTION REGIONS; 1 AU; HELIOSPHERE; SOLAR-CYCLE-23; DECREASES; REVERSAL AB We present a study of the long-term evolution of coronal mass ejections (CMEs) observed by the Large Angle and Spectrometric Coronograph (LASCO) on board SOHO during the ascending, maximum, and part of the descending phases of solar cycle 23 and their relation with the modulation of galactic cosmic-ray (GCR) intensity observed at 1 AU by the Climax neutron monitor and IMP-8 spacecraft. We compare the long-term GCR modulation with the CME occurrence rate at all, low, and high latitudes, as well as the observed CME parameters ( width and speed). Twenty-seven day averages of CME occurrence rates and CME properties from 1996 January to 2003 December are presented in the Appendix. The general anticorrelation between GCR intensity and the CME rate is relatively high (similar to-0.88). However, when we divide the CME rate into low- and high-latitude rates and compare them with the GCR intensity during the ascending phase of solar cycle 23, we find a lower anticorrelation between the low-latitude the CME rate and GCR intensity (similar to-0.71) and a very high anticorrelation between the high-latitude CME rate and GCR intensity (similar to-0.94). This suggests that, in general, CMEs could cause the decrease in the GCR flux in the inner heliosphere, as stated by the global merged interaction region (GMIR) theory. In particular, during the ascending phase of cycle 23 (qA > 0), this flux comes mainly from heliospheric polar regions. Thus, high-latitude CMEs may play a central role in the long-term cosmic-ray modulation during this phase of the cycle by blocking the polar entrance of GCRs to the inner heliosphere. This study supports the scenario in which CMEs, among other structures, are the building blocks of GMIRs, although we propose that the spherical shells ( GMIRs) are closed separately at polar and equatorial regions by CMEs of different latitudes. Our results suggest that all CME properties show some correlation with the GCR intensity, although there is no specific property ( width, speed, or a proxy of energy) that definitely has a higher correlation with GCR intensity. C1 Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico. RI Gopalswamy, Nat/D-3659-2012; OI Caballero, Rogelio/0000-0001-8954-1927; Lara, Alejandro/0000-0001-6336-5291; Gopalswamy, Nat/0000-0001-5894-9954 NR 37 TC 15 Z9 16 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 2005 VL 625 IS 1 BP 441 EP 450 DI 10.1086/428565 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 925IK UT WOS:000229046600037 ER PT J AU Tylka, AJ Cohen, CMS Dietrich, WF Lee, MA Maclennan, CG Mewaldt, RA Ng, CK Reames, DV AF Tylka, AJ Cohen, CMS Dietrich, WF Lee, MA Maclennan, CG Mewaldt, RA Ng, CK Reames, DV TI Shock geometry, seed populations, and the origin of variable elemental composition at high energies in large gradual solar particle events SO ASTROPHYSICAL JOURNAL LA English DT Review DE acceleration of particles; shock waves; sun : coronal mass ejections ( CMEs); sun : flares; sun : particle emission ID CORONAL MASS EJECTION; ADVANCED COMPOSITION EXPLORER; II RADIO-EMISSION; ANOMALOUS COSMIC-RAYS; IONIC CHARGE-STATE; EARTHS BOW SHOCK; ENERGETIC PARTICLES; INTERPLANETARY SHOCKS; MAGNETIC-FIELD; DRIVEN SHOCKS AB Above a few tens of MeV per nucleon, large, gradual solar energetic particle (SEP) events are highly variable in their spectral characteristics and elemental composition. The origin of this variability has been a matter of intense and ongoing debate. In this paper, we propose that this variability arises from the interplay of two factors-shock geometry and a compound seed population, typically comprising both solar-wind and flare suprathermals. Whereas quasi-parallel shocks generally draw their seeds from solar-wind suprathermals, quasi-perpendicular shocks-by requiring a higher initial speed for effective injection-preferentially accelerate seed particles from flares. Solar-wind and flare seed particles have distinctive compositional characteristics, which are then reflected in the accelerated particles. We first examine our hypothesis in the context of particles locally accelerated near 1 AU by traveling interplanetary shocks. We illustrate the implications of our hypothesis for SEPs with two very large events, 2002 April 21 and 2002 August 24. These two events arise from very similar solar progenitors but nevertheless epitomize extremes in high-energy SEP variability. We then test our hypothesis with correlation studies based on observations of 43 large SEP events in 1997-2003 by the Advanced Composition Explorer, Wind, the Interplanetary Monitoring Platform 8, and GOES. We consider correlations among high-energy Fe/O, event size, spectral characteristics, the presence of GeV protons, and event duration at high energies. The observed correlations are all qualitatively consistent with our hypothesis. Although these correlation studies cannot be construed as proof of our hypothesis, they certainly confirm its viability. We also examine the alternative hypothesis in which a direct flare component rather than flare particles subsequently processed through a shock-dominates at high energies. This alternative would produce compositional characteristics similar to those of our hypothesis. However, the observed longitude distribution of the enhanced Fe/O events, their spectral characteristics, and recent timing studies all pose serious challenges for a direct flare component. We also comment on measurements of the mean ionic charge state of Fe at high energies. We conclude that shock geometry and seed population potentially provide a framework for understanding the overall high-energy variability in large SEP events. We suggest additional studies for testing this hypothesis. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. CALTECH, Pasadena, CA 91125 USA. Univ Chicago, Lab Astrophys & Space Res, Chicago, IL 60637 USA. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ New Hampshire, Inst Study Earth Ocean & Space, Durham, NH 03824 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Tylka, AJ (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Code 7652, Washington, DC 20375 USA. EM allan.tylka@nrl.navy.mil; cohen@srl.caltech.edu; dietrich@odysseus.uchicago.edu; marty.lee@unh.edu; cgm@physics.bell-labs.com; rmewaldt@srl.caltech.edu; cheeng@lheapop.gsfc.nasa.gov; reames@milkyway.gsfc.nasa.gov RI Tylka, Allan/G-9592-2014 NR 114 TC 214 Z9 221 U1 2 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 MAY 20 PY 2005 VL 625 IS 1 BP 474 EP 495 DI 10.1086/429384 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 925IK UT WOS:000229046600040 ER PT J AU Campana, S Antonelli, LA Chincarini, G Covino, S Cusumano, G Malesani, D Mangano, V Moretti, A Pagani, C Romano, P Tagliaferri, G Capalbi, M Perri, M Giommi, P Angelini, L Boyd, P Burrows, DN Hill, JE Gronwall, C Kennea, JA Kobayashi, S Kumar, P Meszaros, P Nousek, JA Roming, PWA Zhang, B Abbey, AF Beardmore, AP Breeveld, A Goad, MR Godet, O Mason, KO Osborne, JP Page, KL Poole, T Gehrels, N AF Campana, S Antonelli, LA Chincarini, G Covino, S Cusumano, G Malesani, D Mangano, V Moretti, A Pagani, C Romano, P Tagliaferri, G Capalbi, M Perri, M Giommi, P Angelini, L Boyd, P Burrows, DN Hill, JE Gronwall, C Kennea, JA Kobayashi, S Kumar, P Meszaros, P Nousek, JA Roming, PWA Zhang, B Abbey, AF Beardmore, AP Breeveld, A Goad, MR Godet, O Mason, KO Osborne, JP Page, KL Poole, T Gehrels, N TI Swift observations of GRB 050128: The early X-ray afterglow SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; X-rays : individual (GRB 050128) ID WIND-INTERACTION-MODELS; BURST AFTERGLOWS; TELESCOPE AB Swift discovered GRB 050128 with the Burst Alert Telescope and promptly pointed its narrow field instruments to monitor the afterglow. X-ray observations started 108 s after the trigger time. The early decay of the afterglow is relatively flat, with a temporal decay modeled with a power-law index of similar to-0.3. A steepening occurs at later times (similar to 1500 s) with a power-law index of similar to-1.3. During this transition, the observed X- ray spectrum does not change. We interpret this behavior as either an early jet break or evidence of a transition from the fast cooling regime to the slow cooling regime in a wind environment. C1 Osserv Astron Brera, INAF, I-23807 Merate, LC, Italy. Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. Univ Milan, Dipartimento Fis, I-20126 Milan, Italy. INAF, Ist Astrofis Spaziale & Fis Cosm, Sez Palermo, I-90146 Palermo, Italy. SISSA, ISAS, I-34014 Trieste, Italy. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. ASI Sci Data Ctr, I-00044 Frascati, Rome, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Penn State Univ, Ctr Gravitat Wave Phys, University Pk, PA 16802 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. RP Campana, S (reprint author), Osserv Astron Brera, INAF, Via Bianchi 46, I-23807 Merate, LC, Italy. EM campana@merate.mi.astro.it RI Boyd, Patricia/D-3274-2012; Gehrels, Neil/D-2971-2012; OI Covino, Stefano/0000-0001-9078-5507; Tagliaferri, Gianpiero/0000-0003-0121-0723; Campana, Sergio/0000-0001-6278-1576; Perri, Matteo/0000-0003-3613-4409 NR 24 TC 28 Z9 29 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 MAY 20 PY 2005 VL 625 IS 1 BP L23 EP L26 DI 10.1086/430883 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 925IQ UT WOS:000229047200006 ER PT J AU Desai, P Brickhouse, NS Drake, JJ Dupree, AK Edgar, RJ Hoogerwerf, R Kashyap, V Wargelin, BJ Smith, RK Huenemoerder, DP Liedahl, DA AF Desai, P Brickhouse, NS Drake, JJ Dupree, AK Edgar, RJ Hoogerwerf, R Kashyap, V Wargelin, BJ Smith, RK Huenemoerder, DP Liedahl, DA TI An assessment of the Fe XVIII and Fe XIX line ratios from the Chandra grating observations of Capella SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; atomic processes; stars : individual ( Capella); ultraviolet : stars; X-rays : stars ID FLUORINE-LIKE IONS; L-SHELL IONS; LABORATORY MEASUREMENTS; EXTREME-ULTRAVIOLET; ATOMIC DATABASE; EMISSION-LINES; XMM-NEWTON; IRON; ABUNDANCES; SPECTROMETER AB Observations of Fe XVIII and Fe XIX X-ray, extreme-UV, and far-UV line emission, formed at the peak of Capella's (α Aurigae's) emission measure distribution and ubiquitous in spectra of many cool stars and galaxies, provide a unique opportunity to test the robustness of Fe XVIII and Fe XIX spectral models. The Astrophysical Plasma Emission Code (APEC) is used to identify over 35 lines from these two ions alone, and to compare model predictions with spectra obtained with the Chandra Low Energy Transmission Grating and High Energy Transmission Grating Spectrometers, the Far Ultraviolet Spectroscopic Explorer (FUSE), and the Extreme Ultraviolet Explorer. Some flux discrepancies larger than a factor of 2 are found between observations of Fe XVIII and Fe XIX lines and predictions by APEC and other models in common use. In particular, the X-ray resonance lines for both ions are stronger than predicted by all models relative to the EUV resonance lines. The multi-wavelength observations demonstrate the importance of including dielectronic recombination and proton-impact excitation, and of using accurate wavelengths in spectral codes. These ions provide important diagnostic tools for 10(7) K plasmas currently observed with Chandra, XMM-Newton, and FUSE. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. MIT, Space Res Ctr, Cambridge, MA 02139 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Desai, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM pdesai@cfa.harvard.edu OI Brickhouse, Nancy/0000-0002-8704-4473 NR 30 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 MAY 20 PY 2005 VL 625 IS 1 BP L59 EP L62 DI 10.1086/430882 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 925IQ UT WOS:000229047200015 ER PT J AU Markowitz, A Uttley, P AF Markowitz, A Uttley, P TI Low-luminosity active galactic nuclei as analogs of galactic black holes in the low/hard state: Evidence from X-ray timing of NGC 4258 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual NGC 4258); X-rays : galaxies ID ADVECTION-DOMINATED ACCRETION; SEYFERT-1 GALAXIES; CYGNUS X-1; VARIABILITY; BINARIES; CORONA; REFLECTION; TRANSITION; DENSITIES; OUTBURST AB We present a broadband power spectral density function (PSD) measured from extensive RXTE monitoring data of the low-luminosity active galactic nucleus (LLAGN) NGC 4258, which has an accurate, maser-determined black hole mass of (3.9 &PLUSMN; 0.1) X 10(7) M-&ODOT;. We constrain the PSD break timescale to be greater than 4.5 days at > 90% confidence, which appears to rule out the possibility that NGC 4258 is an analog of black hole X-ray binaries (BHXRBs) in the high/soft state. In this sense, the PSD of NGC 4258 is different from those of some more luminous Seyfert galaxies, which appear similar to the PSDs of high/soft state X-ray binaries. This result supports previous analogies between LLAGNs and X-ray binaries in the low/hard state based on spectral energy distributions, indicating that the AGN/BHXRB analogy is valid across a broad range of accretion rates. C1 NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. RP Markowitz, A (reprint author), NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Code 662, Greenbelt, MD 20771 USA. EM agm@milkyway.gsfc.nasa.gov; pu@milkyway.gsfc.nasa.gov NR 41 TC 16 Z9 16 U1 0 U2 1 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 MAY 20 PY 2005 VL 625 IS 1 BP L39 EP L42 DI 10.1086/430762 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 925IQ UT WOS:000229047200010 ER PT J AU Heymsfield, AJ Winker, D van Zadelhoff, GJ AF Heymsfield, AJ Winker, D van Zadelhoff, GJ TI Extinction-ice water content-effective radius algorithms for CALIPSO SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLOUD MICROPHYSICAL PROPERTIES; PARTICLE-SIZE; CIRRUS; PARAMETERIZATION; TEMPERATURE; TERMS; LIDAR AB Interrelationships between volume extinction coefficient (σ), ice water content (IWC), and effective radius (r(e)), each dependent upon the particle size distribution (PSD) and temperature (T), are developed using in-situ microphysical measurements at low and mid-latitudes, remote sensing data, and model results. The ratio [(IWC)/σ], proportional to r(e), increases with T. Lower values of [IWC/σ] are observed near cloud top and base than within a cloud layer, although [IWC/σ] changes more with temperature than relative height within the cloud. For equivalent radar reflectivities (Z(e)) below about -28 dB, the minimum detectable with forthcoming spaceborne cloud radar, [IWC/σ] is a nearly constant value. IWC increases almost linearly with σ, with a temperature-dependence noted. C1 Natl Ctr Atmospher Res, Boulder, CO 80301 USA. Koninklijk Nederlands Meteorol Inst, NL-3730 AE De Bilt, Netherlands. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. RP Heymsfield, AJ (reprint author), Natl Ctr Atmospher Res, 3450 Mitchell Lane, Boulder, CO 80301 USA. EM heyms1@ucar.edu; david.m.winker@nasa.gov; zadelhof@knmi.nl RI Heymsfield, Andrew/E-7340-2011; van Zadelhoff, Gerd-Jan/K-6283-2013 NR 13 TC 37 Z9 38 U1 0 U2 7 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 MAY 20 PY 2005 VL 32 IS 10 AR L10807 DI 10.1029/2005GL022742 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 932WH UT WOS:000229584700005 ER PT J AU Bernhard, G Evans, RD Labow, GJ Oltmans, SJ AF Bernhard, G Evans, RD Labow, GJ Oltmans, SJ TI Bias in Dobson total ozone measurements at high latitudes due to approximations in calculations of ozone absorption coefficients and air mass SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CROSS-SECTIONS; SPECTROPHOTOMETERS; ULTRAVIOLET; BREWER; VALIDATION; IRRADIANCE; RADIATION; NETWORK; RANGE; O-3 AB [ 1] The Dobson spectrophotometer is the primary standard instrument for ground-based measurements of total column ozone. The accuracy of its data depends on the knowledge of ozone absorption coefficients used for data reduction. We document an error in the calculations that led to the set of absorption coefficients currently recommended by the World Meteorological Organisation (WMO). This error has little effect because an empirical adjustment was applied to the original calculations before the coefficients were adopted by WMO. We provide evidence that this adjustment was physically sound. The coefficients recommended by WMO are applied in the Dobson network without correction for the temperature dependence of the ozone absorption cross sections. On the basis of data measured by Dobson numbers 80 and 82, which were operated by the National Oceanic and Atmospheric Administration (NOAA) Climate Monitoring and Diagnostics Laboratory at the South Pole, we find that omission of temperature corrections may lead to systematic errors in Dobson ozone data of up to 4%. The standard Dobson ozone retrieval method further assumes that the ozone layer is located at a fixed height. This approximation leads to errors in air mass calculations, which are particularly relevant at high latitudes where ozone measurements are performed at large solar zenith angles (SZA). At the South Pole, systematic errors caused by this approximation may exceed 2% for SZAs larger than 80 degrees. The bias is largest when the vertical ozone distribution is distorted by the "ozone hole'' and may lead to underestimation of total ozone by 4% at SZA = 85 degrees ( air mass 9). Dobson measurements at the South Pole were compared with ozone data from a collocated SUV-100 UV spectroradiometer and Version 8 overpass data from NASA's Total Ozone Mapping Spectrometer ( TOMS). Uncorrected Dobson ozone values tend to be lower than data from the two other instruments when total ozone is below 170 Dobson units or SZAs are larger than 80 degrees. When Dobson measurements are corrected for the temperature dependence of the ozone absorption cross section and accurate air mass calculations are implemented, data from the three instruments agree with each other to within +/- 2% on average and show no significant dependence on SZA or total ozone. C1 Biospher Inc, San Diego, CA 92110 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bernhard, G (reprint author), Biospher Inc, 5340 Riley St, San Diego, CA 92110 USA. EM bernhard@biospherical.com; robert.d.evans@noaa.gov; labow@qhearts.gsfc.nasa.gov; samuel.j.oltmans@noaa.gov RI Evans, Robert/D-4731-2016 OI Evans, Robert/0000-0002-8693-9769 NR 37 TC 29 Z9 30 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 MAY 20 PY 2005 VL 110 IS D10 AR D10305 DI 10.1029/2004JD005559 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 932WM UT WOS:000229585200007 ER PT J AU Chen, G Huey, LG Trainer, M Nicks, D Corbett, J Ryerson, T Parrish, D Neuman, JA Nowak, J Tanner, D Holloway, J Brock, C Crawford, J Olson, JR Sullivan, A Weber, R Schauffler, S Donnelly, S Atlas, E Roberts, J Flocke, F Hubler, G Fehsenfeld, F AF Chen, G Huey, LG Trainer, M Nicks, D Corbett, J Ryerson, T Parrish, D Neuman, JA Nowak, J Tanner, D Holloway, J Brock, C Crawford, J Olson, JR Sullivan, A Weber, R Schauffler, S Donnelly, S Atlas, E Roberts, J Flocke, F Hubler, G Fehsenfeld, F TI An investigation of the chemistry of ship emission plumes during ITCT 2002 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MARINE BOUNDARY-LAYER; PEM-TROPICS-A; AEROSOL CHARACTERIZATION; CHEMICAL EVOLUTION; CARBON-MONOXIDE; PARTICLE-SIZE; SOUTH-PACIFIC; TRACE GASES; DISTRIBUTIONS; CLOUDS AB [1] A ship emission plume experiment was conducted about 100 km off the California coast during the NOAA Intercontinental Transport and Chemical Transformation (ITCT) 2K2 airborne field campaign. Measurements of chemical species were made from the NOAA WP-3D aircraft in eight consecutive transects of a ship plume around midday during 2.5 hours of flight. The measured species include NOx, HNO3, peroxyacetylnitrate (PAN), SO2, H2SO4, O-3, CO, CO2, nonmethane hydrocarbons (NMHC), and particle number and size distributions. Observations demonstrate a NOx lifetime of similar to 1.8 hours inside the ship plume compared to similar to 6.5 hours ( at noontime) in the moderately polluted background marine boundary layer of the experiment. This confirms the earlier hypothesis of highly enhanced in-plume NOx destruction. Consequently, one would expect the impact of ship emissions is much less severe than those predicted by global models that do not include rapid NOx destruction. Photochemical model calculations suggest that more than 80% of the NOx loss was due to the NO2 + OH reaction; the remainder was by PAN formation. The model underestimated in-plume NOx loss rate by about 30%. In addition, a comparison of measured to predicted H2SO4 in the plumes suggests that the photochemical model predicts OH variability reasonably well but may underestimate actual values. Predictions of in-plume O-3 production agree well with the observations, suggesting that model-predicted peroxy radical (HO2 + RO2) levels are reasonable. The model estimated ozone production efficiency ranges from 6 to 30. The largest model bias was seen in the comparison with measured HNO3. The model overestimated in-plume HNO3 by about a factor of 6. This is most likely caused by underestimated HNO3 sinks possibly involving particle scavenging. However, limited data availability precluded a conclusive test of this possible loss process. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine & Atmospher Chem, Miami, FL 33149 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. RP Chen, G (reprint author), NASA, Langley Res Ctr, Mail Stop 401B, Hampton, VA 23681 USA. EM g.chen@larc.nasa.gov RI Nowak, John/B-1085-2008; Roberts, James/A-1082-2009; Neuman, Andy/A-1393-2009; Crawford, James/L-6632-2013; Atlas, Elliot/J-8171-2015; Hubler, Gerhard/E-9780-2010; Corbett, James/B-3321-2009; Parrish, David/E-8957-2010; Brock, Charles/G-3406-2011; Holloway, John/F-9911-2012; Trainer, Michael/H-5168-2013; Ryerson, Tom/C-9611-2009; Fehsenfeld, Frederick/I-4876-2013 OI Nowak, John/0000-0002-5697-9807; Roberts, James/0000-0002-8485-8172; Neuman, Andy/0000-0002-3986-1727; Crawford, James/0000-0002-6982-0934; Corbett, James/0000-0002-2588-3474; Parrish, David/0000-0001-6312-2724; Brock, Charles/0000-0002-4033-4668; Holloway, John/0000-0002-4585-9594; NR 70 TC 54 Z9 54 U1 1 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAY 20 PY 2005 VL 110 IS D10 AR D10S90 DI 10.1029/2004JD005236 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 932WM UT WOS:000229585200003 ER PT J AU Bahcivan, H Hysell, DL Larsen, MF Pfaff, RF AF Bahcivan, H Hysell, DL Larsen, MF Pfaff, RF TI The 30 MHz imaging radar observations of auroral irregularities during the JOULE campaign SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID FARLEY-BUNEMAN INSTABILITY; ELECTRON-DRIFT VELOCITY; E-REGION IRREGULARITIES; UNSTABLE PLASMA-WAVES; DAYTIME EQUATORIAL ELECTROJET; POLAR E-REGION; COHERENT BACKSCATTER; DENSITY MEASUREMENTS; FIELD VARIABILITY; STARE VELOCITIES AB Coherent backscatter from the auroral electrojet was observed by a 30 MHz imaging radar in Anchorage during the Joint Observations of Upper Latitude Electrodynamics ( JOULE) campaign conducted from the Poker Flat Research Range in the spring of 2003. The observations were made at the same time that ionospheric electric fields and plasma number densities were measured in situ by instruments on sounding rockets. Neutral wind profiles were also measured during the campaign from triangulation of chemiluminescent trails from rocket releases. Aperture synthesis radar imaging techniques permit the sorting of the coherent backscatter into small azimuth and range bins and the determination of the scattering altitude. Individual Doppler spectra could thereby be unambiguously associated with in situ electric field measurements in the same small volume. We find that the Doppler shifts of the auroral echoes correspond to the ion acoustic speed times the cosine of the flow angle, where the former is predicted according to an empirical wave heating law. Type I echoes are only observed for very small flow angles regardless of the convection speed. C1 Cornell Univ, Sch Elect & Comp Engn, Ithaca, NY 14853 USA. Cornell Univ, Dept Earth & Atmospher Sci, Ithaca, NY 14853 USA. Clemson Univ, Dept Phys, Clemson, SC 29634 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bahcivan, H (reprint author), Cornell Univ, Sch Elect & Comp Engn, Ithaca, NY 14853 USA. EM hb53@cornell.edu; daveh@geology.cornell.edu RI Larsen, Miguel/A-1079-2013; Pfaff, Robert/F-5703-2012 OI Pfaff, Robert/0000-0002-4881-9715 NR 53 TC 39 Z9 39 U1 1 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 MAY 20 PY 2005 VL 110 IS A5 AR A05307 DI 10.1029/2004JA010975 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 932XD UT WOS:000229587200005 ER PT J AU Fialko, Y Sandwell, D Simons, M Rosen, P AF Fialko, Y Sandwell, D Simons, M Rosen, P TI Three-dimensional deformation caused by the Bam, Iran, earthquake and the origin of shallow slip deficit SO NATURE LA English DT Article ID HECTOR MINE EARTHQUAKE; SAN-ANDREAS FAULT; TRANSIENT STRAIN ACCUMULATION; RADAR INTERFEROMETRY; LANDERS-EARTHQUAKE; POSTSEISMIC DEFORMATION; SURFACE DISPLACEMENT; SUPERSTITION HILLS; IZMIT MAINSHOCK; HAYWARD FAULT AB Our understanding of the earthquake process requires detailed insights into how the tectonic stresses are accumulated and released on seismogenic faults. We derive the full vector displacement field due to the Bam, Iran, earthquake of moment magnitude 6.5 using radar data from the Envisat satellite of the European Space Agency. Analysis of surface deformation indicates that most of the seismic moment release along the 20-km-long strike-slip rupture occurred at a shallow depth of 4 - 5 km, yet the rupture did not break the surface. The Bam event may therefore represent an end-member case of the 'shallow slip deficit' model, which postulates that coseismic slip in the uppermost crust is systematically less than that at seismogenic depths ( 4 - 10 km). The InSAR-derived surface displacement data from the Bam and other large shallow earthquakes suggest that the uppermost section of the seismogenic crust around young and developing faults may undergo a distributed failure in the interseismic period, thereby accumulating little elastic strain. C1 Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92093 USA. CALTECH, Div Geol & Planetary Sci, Seismol Lab, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fialko, Y (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92093 USA. EM fialko@radar.ucsd.edu RI Fialko, Yuri/B-9567-2012; Simons, Mark/N-4397-2015; OI Fialko, Yuri/0000-0002-6161-8467; Simons, Mark/0000-0003-1412-6395; Sandwell, David/0000-0001-5657-8707 NR 46 TC 154 Z9 173 U1 2 U2 23 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAY 19 PY 2005 VL 435 IS 7040 BP 295 EP 299 DI 10.1038/nature03425 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 927HM UT WOS:000229185000035 PM 15902247 ER PT J AU Gutsev, GL Mochena, MD Bauschlicher, CW AF Gutsev, GL Mochena, MD Bauschlicher, CW TI Dissociative and associative attachment of OH to iron clusters SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; GAUSSIAN-BASIS SETS; GAS-PHASE; IONIZATION ENERGIES; FE-N; WATER; ATOMS; REPRESENTATION; ACTIVATION; REACTIVITY AB Electronic and geometrical structures of isomers of FenOH, FenOH-, and FenOH+ (n = 1-4) with associative and dissociative attachment of OH are computed using density functional theory with generalized gradient approximation. It is found that OH is associatively attached in the ground-state FeOH and FeOH+ species, but is dissociatively attached in FeOH-. The neutral and negatively charged species with n = 2-4 prefer dissociative attachment of OH. In the ground-state Fe3OH+ and Fe4OH+ cations, OH is attached associatively, while it is attached dissociatively in Fe2OH+. © 2005 Elsevier B.V. All rights reserved. C1 Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gutsev, GL (reprint author), Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA. EM gennady.gutsev@famu.edu NR 33 TC 3 Z9 3 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAY 17 PY 2005 VL 407 IS 1-3 BP 180 EP 185 DI 10.1016/j.cplett.2005.03.040 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 925PX UT WOS:000229066200036 ER PT J AU Li, QB Jacob, DJ Park, R Wang, YX Heald, CL Hudman, R Yantosca, RM Martin, RV Evans, M AF Li, QB Jacob, DJ Park, R Wang, YX Heald, CL Hudman, R Yantosca, RM Martin, RV Evans, M TI North American pollution outflow and the trapping of convectively lifted pollution by upper-level anticyclone SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RESOLUTION IMAGING SPECTRORADIOMETER; TRACE GAS-COMPOSITION; UNITED-STATES; TROPOSPHERIC OZONE; CARBON-MONOXIDE; ATLANTIC-OCEAN; MIDLATITUDE CYCLONES; 15-YEAR CLIMATOLOGY; FOREST-FIRES; TRANSPORT AB [1] We examine the major outflow pathways for North American pollution to the Atlantic in summer by conducting a 4-year simulation with the GEOS-CHEM global chemical transport model, including a coupled ozone-aerosol simulation with 1 degrees x 1 degrees horizontal resolution for summer 2000. The outflow is driven principally by cyclones tracking eastward across North America at 45 - 55 degrees N, every 5 days on average. Anthropogenic and fire effluents from western North America are mostly transported north and east, eventually merging with the eastern U. S. pollution outflow to the Atlantic. A semipermanent upper-level anticyclone traps the convective outflow and allows it to age in the upper troposphere over the United States for several days. Rapid ozone production takes place in this outflow, driven in part by anthropogenic and lightning NOx and in part by HOx radicals produced from convectively lifted CH2O that originates from biogenic isoprene. This mechanism could explain ozonesonde observations of elevated ozone in the upper troposphere over the southeastern United States. Asian and European pollution influences in the North American outflow to the Atlantic are found to be dispersed into the background and do not generate distinct plumes. Satellite observations of CO columns from MOPITT and of aerosol optical depths (AODs) from MODIS provide useful mapping of outflow events, despite their restriction to clear-sky scenes. C1 Univ Leeds, Sch Environm, Leeds LS2 0TJ, W Yorkshire, England. Harvard Univ, Dept Earth & Planetary Sci, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS B3H 3J5, Canada. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 183-501, Pasadena, CA 91109 USA. EM qinbin.li@jpl.nasa.gov RI Martin, Randall/A-2051-2008; Heald, Colette/A-6813-2011; Hudman, Rynda/C-6118-2009; Evans, Mathew/A-3886-2012; Martin, Randall/C-1205-2014; Wang, Yuxuan/C-6902-2014; Yantosca, Robert/F-7920-2014; Chem, GEOS/C-5595-2014; Park, Rokjin/I-5055-2012 OI Evans, Mathew/0000-0003-4775-032X; Martin, Randall/0000-0003-2632-8402; Wang, Yuxuan/0000-0002-1649-6974; Yantosca, Robert/0000-0003-3781-1870; Park, Rokjin/0000-0001-8922-0234 NR 76 TC 98 Z9 99 U1 0 U2 18 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 MAY 17 PY 2005 VL 110 IS D10 AR D10301 DI 10.1029/2004JD005039 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 932WK UT WOS:000229585000001 ER PT J AU Liu, WT Tang, WQ AF Liu, WT Tang, WQ TI Estimating moisture transport over oceans using space-based observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR TRANSPORT; BALANCE; VARIABILITY; FLUX AB [1] The moisture transport integrated over the depth of the atmosphere (Theta) is estimated over oceans using satellite data. The transport is the product of the precipitable water and an equivalent velocity (u(e)), which, by definition, is the depth-averaged wind velocity weighted by humidity. An artificial neural network is employed to construct a relation between the surface wind velocity measured by the spaceborne scatterometer and coincident ue derived using humidity and wind profiles measured by rawinsondes and produced by reanalysis of operational numerical weather prediction (NWP). On the basis of this relation, Theta fields are produced over global tropical and subtropical oceans ( 40 degrees N 40 degrees S) at 0.25 degrees latitude-longitude and twice daily resolutions from August 1999 to December 2003 using surface wind vector from QuikSCAT and precipitable water from the Tropical Rain Measuring Mission. The derived ue were found to capture the major temporal variability when compared with radiosonde measurements. The average error over global oceans, when compared with NWP data, was comparable with the instrument accuracy specification of space-based scatterometers. The global distribution exhibits the known characteristics of, and reveals more detailed variability than in, previous data. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Liu, WT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM liu@pacific.jpl.nasa.gov NR 25 TC 13 Z9 13 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 MAY 17 PY 2005 VL 110 IS D10 AR D10101 DI 10.1029/2004JD005300 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 932WK UT WOS:000229585000002 ER PT J AU Lee, TS Chen, YH Chuang, JCH AF Lee, TS Chen, YH Chuang, JCH TI Robust control design of fuzzy dynamical systems SO APPLIED MATHEMATICS AND COMPUTATION LA English DT Article; Proceedings Paper CT 12th International Workshop on Dynamics and Control CY AUG 19-22, 2002 CL Univ Calif Los Angeles, Los Angeles, CA HO Univ Calif Los Angeles DE fuzzy systems; robust control; stability ID STABILITY; IDENTIFICATION; MODEL AB This paper presents stability analysis and robust control design for Takagi and Sugeno (T S) fuzzy dynamical systems. A systematic approach is proposed to check the stability of the T-S fuzzy system. We then extend the consideration to the uncertainty case, which can be nonlinear and (possibly fast) time-varying. Only the possible bound of the uncertainty is needed. If the uncertainty is matched, a robust control scheme is proposed, which renders the fuzzy system practically stable. If the uncertainty is mismatched, we show that a mismatched threshold is needed to ensure stability. (c) 2004 Elsevier Inc. All rights reserved. C1 Georgia Inst Technol, George W Woodruff Sch Mech Engn, Atlanta, GA 30332 USA. NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Chen, YH (reprint author), Georgia Inst Technol, George W Woodruff Sch Mech Engn, Atlanta, GA 30332 USA. EM yehwa.chen@me.gatech.edu NR 14 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0096-3003 J9 APPL MATH COMPUT JI Appl. Math. Comput. PD MAY 16 PY 2005 VL 164 IS 2 BP 555 EP 572 DI 10.1016/j.amc.2004.06.045 PG 18 WC Mathematics, Applied SC Mathematics GA 918LY UT WOS:000228544500019 ER PT J AU Zhang, B Harb, JN Davis, RC Kim, JW Chu, SH Choi, S Miller, T Watt, GD AF Zhang, B Harb, JN Davis, RC Kim, JW Chu, SH Choi, S Miller, T Watt, GD TI Kinetic and thermodynamic characterization of the cobalt and manganese oxyhydroxide cores formed in horse spleen ferritin SO INORGANIC CHEMISTRY LA English DT Article ID PROTEIN CAGE; MAMMALIAN FERRITIN; LISTERIA-INNOCUA; STORAGE; BACTERIOFERRITIN; NANOPARTICLES; NANOMATERIALS; SPECTROSCOPY; APOFERRITIN; RELEASE AB Horse spleen ferritin (HoSF) containing 800-1500 cobalt or 250-1200 manganese atoms as Co(O)OH and Mn(O)OH mineral cores within the HoSF interior (Co-HoSF and Mn-HoSF) was synthesized, and the chemical reactivity, kinetics of reduction, and the reduction potentials were measured, Microcoulometric and chemical reduction of HoSF containing the M(O)OH mineral core (M = Co or Mn) was rapid and quantitative with a reduction stoichiometry of 1.05 &PLUSMN; 0.10 e/M forming a stable M(OH)(2) mineral core. At pH 9.0, ascorbic acid (AH(2)), a two-electron reductant, effectively reduced the mineral cores; however, the reaction was incomplete and rapidly reached equilibrium. The addition of excess AH(2) shifted the reaction to completion with a M3+/AH(2) stoichiometry of 1.9-2.1, consistent with a single electron per metal atom reduction. The rate of reaction between M(O)OH and excess AH(2) was measured by monitoring the decrease in mineral core absorbance with time. The reaction was first order in each reactant with second-order rate constants of 0.53 and 4.74 M-1 min(-1), respectively, for Co- and Mn-HoSF at pH 9.0. From the variation of absorbance with increasing AH(2) Concentration, equilibrium constants at pH 9.0 of 5.0 &PLUSMN; 1.9 for Co-HoSF and 2.9 &PLUSMN; 0.9 for Mn-HoSF were calculated for 2M(O)OH + AH(2) = 2M(OH)(2) + D, where AH(2) and D are ascorbic acid and dehydroascorbic acid, respectively, Consistent with these equilibrium constants, the standard potential for the reduction of Co(III)-HoSF is 42 mV more positive than that of the ascorbic acid reaction, while the standard potential of Mn(III)-HoSF is 27 mV positive relative to AH(2). Fe2+ in solution with Co- and Mn-HoSF under anaerobic conditions was oxidized to form Fe(O)OH within the HoSF interior, resulting in partial displacement of the Co or Mn by iron. C1 Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA. Brigham Young Univ, Dept Chem Engn, Provo, UT 84602 USA. Brigham Young Univ, Dept Phys, Provo, UT 84602 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Watt, GD (reprint author), Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA. EM gdwatt@chem.byu.edu RI Kim, Jae-Woo/A-8314-2008 NR 26 TC 25 Z9 25 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD MAY 16 PY 2005 VL 44 IS 10 BP 3738 EP 3745 DI 10.1021/ic0490851 PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 926MJ UT WOS:000229127000048 PM 15877458 ER PT J AU Brillson, LJ Bradley, ST Tumakha, SH Goss, SH Sun, XLL Okojie, RS Hwang, J Schaff, WJ AF Brillson, LJ Bradley, ST Tumakha, SH Goss, SH Sun, XLL Okojie, RS Hwang, J Schaff, WJ TI Local electronic and chemical structure at GaN, AlGaN and SiC heterointerfaces SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 12th International Conference on Solid Films and Surface (ICSFS-12) CY JUN 21-25, 2004 CL Hamamatsu, JAPAN SP Suzuki Motor Corp, Murata Sci Fdn, Shizuoka Univ Fund Engn res, Promotion Elect Engn Hamamatsu, Hamamatsu & Hamamatsu Vistors & Convent Bureau DE Schottky barriers; interface states; cathodoluminescence; GaN; AlGaN; SiC ID INTERFACES; TRANSFORMATION; SPECTROSCOPY; CONTACTS; 4H AB Defects and intermediate chemical phases at nanoscale heterointerfaces of GaN, AlGaN, and SiC can dominate their macroscopic electronic properties. We have used low energy electron-excited nanoscale luminescence spectroscopy in combination with secondary ion mass spectrometry and internal photoemission spectroscopy to correlate interface physical and electronic properties for a variety of Schottky barrier and heterointerfaces involving these semiconductors. These results demonstrate the key role of initial surface processing and subsequent chemical interaction on the heterointerface electronic states, barriers, and carrier concentrations. (c) 2004 Published by Elsevier B.V. C1 Ohio State Univ, Dreese Lab 205, Columbus, OH 43210 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. Cornell Univ, Dept Elect & Comp Engn, Ithaca, NY 14853 USA. RP Brillson, LJ (reprint author), Ohio State Univ, Dreese Lab 205, 2015 Neil Ave, Columbus, OH 43210 USA. EM brillson.1@osu.edu NR 14 TC 2 Z9 2 U1 0 U2 1 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 MAY 15 PY 2005 VL 244 IS 1-4 BP 257 EP 263 DI 10.1016/j.apsusc.2004.09.172 PG 7 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 919ED UT WOS:000228600200059 ER PT J AU Bosilovich, MG Schubert, SD Walker, GK AF Bosilovich, MG Schubert, SD Walker, GK TI Global changes of the water cycle intensity SO JOURNAL OF CLIMATE LA English DT Article ID COMMUNITY CLIMATE MODEL; GENERAL-CIRCULATION MODEL; SURFACE TEMPERATURES; HYDROLOGICAL CYCLE; UNITED-STATES; PRECIPITATION; SENSITIVITY; LAND; PARAMETERIZATION; PREDICTABILITY AB In this study, numerical simulations of the twentieth-century climate are evaluated, focusing on the changes in the intensity of the global water cycle. A new model diagnostic of atmospheric water vapor cycling rate is developed and employed that relies on constituent tracers predicted at the model time step. This diagnostic is compared to a simplified traditional calculation of cycling rate, based on monthly averages of precipitation and total water content. The mean sensitivity of both diagnostics to variations in climate forcing is comparable. However, the new diagnostic produces systematically larger values with more variability. Climate simulations were performed using SSTs of the early (1902-21) and late (1979-98) twentieth century along with the appropriate CO2 forcing. In general the increase of global precipitation with the increases in SST that occurred between the early and late twentieth century is small. However, an increase of atmospheric temperature leads to a systematic increase in total precipitable water. As a result, the residence time of water in the atmosphere increased, indicating a reduction of the global cycling rate. This result was explored further using a number of 50-yr climate simulations from different models forced with observed SST. The anomalies and trends in the cycling rate and hydrologic variables of different GCMs are remarkably similar. The global annual anomalies of precipitation show a significant upward trend related to the upward trend of surface temperature, during the latter half of the twentieth century. While this implies an increase in the simulated hydrologic cycle intensity, a concomitant increase of total precipitable water again leads to a decrease in the calculated global cycling rate. An analysis of the land/sea differences shows that the simulated precipitation over land has a decreasing trend, while the oceanic precipitation has an upward trend consistent with previous studies and the available observations. The decreasing continental trend in precipitation is located primarily over tropical land regions, with some other regions, such as North America, experiencing an increasing trend. Precipitation trends are diagnosed further using the water tracers to delineate the precipitation that occurs because of continental evaporation, as opposed to oceanic evaporation. These model diagnostics show that over global land areas, the recycling of continental moisture is decreasing in time. However, the recycling changes are not spatially uniform so that some regions, most notably over the United States, experience continental recycling of water that increases in time. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM michael.bosilovich@nasa.gov RI Bosilovich, Michael/F-8175-2012 NR 53 TC 61 Z9 62 U1 0 U2 14 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PD MAY 15 PY 2005 VL 18 IS 10 BP 1591 EP 1608 DI 10.1175/JCLI3357.1 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 931HO UT WOS:000229476600011 ER PT J AU Duray, PH Yin, SR Ito, Y Bezrukov, L Cox, C Cho, MS Fitzgerald, W Dorward, D Zimmerberg, J Margolis, L AF Duray, PH Yin, SR Ito, Y Bezrukov, L Cox, C Cho, MS Fitzgerald, W Dorward, D Zimmerberg, J Margolis, L TI Invasion of human tissue ex vivo by Borrelia burgdorferi SO JOURNAL OF INFECTIOUS DISEASES LA English DT Article ID HUMAN LYMPHOID-TISSUE; ROTATING-WALL VESSEL; LYME-DISEASE; SIMULATED MICROGRAVITY; GENETIC DIVERSITY; SENSU-STRICTO; HIV-INFECTION; OSPC; PHENOTYPE; DIFFERENTIATION AB Borrelia burgdorferi sensu stricto is an etiological agent of Lyme disease. The lack of an adequate ex vivo system for human tissue infection is an obstacle to fully understanding the molecular mechanisms of invasion of tissue by B. burgdorferi and its adaptation within the human host. Here, we report on the development of such a system. We inoculated blocks of human tonsillar tissue with B. burgdorferi spirochetes, cultured them in a low-shear rotating wall vessel (RWV) bioreactor, and analyzed them using light and electron microscopy, nested polymerase chain reaction (PCR), and quantitative real-time PCR. Also, we evaluated the expression of the outer surface proteins (Osps) OspA and OspC by use of quantitative Western blotting. Light and electron microscopic analysis revealed multiple spirochetes localized extracellularly within the tissue, and their identity was confirmed by PCR. Quantification of spirochetes inside the RWV-cultured tonsillar tissue demonstrated that the number of B. burgdorferi exceeded the initial inoculum by an order of magnitude, indicating that spirochetes replicated in the tissue. Electron microscopic analysis showed that some spirochetes were arranged in cystic structures and that invading spirochetes differentially expressed surface proteins; both of these features have been described for infected tissues in vivo. The system we have developed can be used to study B. burgdorferi pathogenesis under controlled conditions ex vivo, in particular to explore the gene activation responsible for the adaptation of B. burgdorferi to human tissue that leads to Lyme disease. C1 NICHHD, NASA,NAtl Inst Hlth Ctr Dimens Tissue Culture 3, Lab Cellular & Mol Biophys, NIH, Bethesda, MD 20892 USA. NICHHD, Dept Pathol, NIH, Bethesda, MD 20892 USA. NIAID, Rocky Mt Labs, NIH, Hamilton, MT 59840 USA. RP Duray, PH (reprint author), NICHHD, NASA,NAtl Inst Hlth Ctr Dimens Tissue Culture 3, Lab Cellular & Mol Biophys, NIH, 10 Ctr Dr,Bldg 10,Room 9D58, Bethesda, MD 20892 USA. EM paul.duray@med.va.gov; margolis@helix.nih.gov FU Intramural NIH HHS NR 36 TC 15 Z9 15 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0022-1899 J9 J INFECT DIS JI J. Infect. Dis. PD MAY 15 PY 2005 VL 191 IS 10 BP 1747 EP 1754 DI 10.1086/429632 PG 8 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA 917MB UT WOS:000228465000022 PM 15838803 ER PT J AU Li, C Scripa, RN Ban, H Lin, B Su, CH Lehoczky, SL AF Li, C Scripa, RN Ban, H Lin, B Su, CH Lehoczky, SL TI Thermophysical properties of Hg0.8Cd0.2Te melt: Density, electrical conductivity and viscosity SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID DIRECTIONALLY SOLIDIFIED HGCDTE; DISORDERED MATERIALS; GROWTH; SEGREGATION; HG1-XCDXTE; TRANSPORT; ALLOYS; HGTE AB Thermophysical properties, namely, density, viscosity, and electrical conductivity of Hg0.8Cd0.2Te melt were measured as a function of temperature. A pycnometric method was used to measure the melt density in the temperature range of 1072-1122 K. The viscosity and electrical conductivity were simultaneously determined using a transient torque method from 1068 to 1132 K. The density result from this study is within 0.3% of the published data. However, the current viscosity result is approximately 30% lower than the existing data. The electrical conductivity of Hg0.8Cd0.2Te melt as a function of temperature, which is not available in the literature, is also determined. The analysis of the temperature dependent electrical conductivity and the relationship between the kinematic viscosity and density indicated that the structure of the melt appeared to be homogeneous when the temperature was above 1090 K. A structural transition occurred in the Hg0.8Cd0.2Te melt as the temperature was decreased from 1090 K to the liquidus temperature. (c) 2005 Elsevier B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, Huntsville, AL 35812 USA. Univ Alabama, Dept Mat Sci & Engn, Birmingham, AL 35294 USA. Univ Alabama, Dept Mech Engn, Birmingham, AL 35294 USA. RP Li, C (reprint author), NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, SD 46, Huntsville, AL 35812 USA. EM chao.li@msfc.nasa.gov RI Ban, Heng/I-6268-2012 NR 26 TC 2 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD MAY 15 PY 2005 VL 351 IS 14-15 BP 1179 EP 1184 DI 10.1016/j.jnoncrysol.2005.03.005 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 931ZE UT WOS:000229523200002 ER PT J AU Tyson, DS Fabrizio, EF Panzner, MJ Kinder, JD Buisson, JP Christensen, JB Meador, MA AF Tyson, DS Fabrizio, EF Panzner, MJ Kinder, JD Buisson, JP Christensen, JB Meador, MA TI Synthesis, characterization, and optical properties of a cyano-functionalized 2,3,7,8-tetraaryl-1,6-dioxapyrene SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY LA English DT Article DE 1,6-dioxapyrene; synthesis; electronic spectra; luminescence; electrochemistry; solvatochromism ID ELECTROGENERATED CHEMILUMINESCENCE; 1,6-DIOXAPYRENE; NAPHTHALENE; KETONES; <1>BENZOPYRANO<6,5,4-DEF><1>BENZOPYRAN; PHOTOCYCLIZATION; 1,5-BIRADICALS; DERIVATIVES; EMISSION; BEHAVIOR AB 2,7-Di(4-cyanophenyl)-3,8-di(4-methylphenyl)-1,6-dioxapyrene (CN-diox), a symmetrically substituted 2,3,7,8-tetraaryldioxapyrene, was synthesized in seven steps from 1,5-dihydroxynaphthalene. The synthetic methodology incorporated a base-catalyzed ring closure process followed by dehydration to introduce the first tetraaryl-1,6-dioxapyrene. Crystal structure and electrochemical analysis were performed to directly compare the properties of CN-diox to previously reported dioxapyrene derivatives, specifically 1,6-dioxapyrene (Diox) and 3,8-diethyl-5,10-dimethyl-1,6-dioxapyrene (Alkyl-diox). Optical spectroscopy studies were performed to evaluate the potential of the 1,6dioxapyrenes as fluorescent probes. CN-diox revealed a broad absorption centered near 450nm (ε =31,900M(-1) cm(-1)) in THF with a corresponding fluorescence at 619 nm (&UPhi; f = 0.011). This was in sharp contrast to both Diox and Alkyl-diox which displayed broad absorption bands near 400nm (ε &SIM; 5000-10,00M(-1) cm(-1)) in THF with corresponding fluorescence near 500nm (&UPhi;(f) =0.059 and 0.082 for Diox and Alkyl-diox, respectively). The luminescence of CN-diox was found to be solvatochromic (&GIMEL;(max)= 619-644 nm) with single exponential lifetimes of less than 1.3 ns and an excited state dipole moment of &SIM; 22.81 D. Neither Diox nor Alkyl-diox showed solvatochromic properties. © 2004 Elsevier B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Polymers Branch, Div Mat, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. Univ Akron, Dept Chem, Akron, OH 44325 USA. Inst Curie, Serv Chim, F-75248 Paris, France. Univ Copenhagen, Chem Lab 2, DK-2100 Copenhagen, Denmark. RP Meador, MA (reprint author), NASA, Glenn Res Ctr, Polymers Branch, Div Mat, Cleveland, OH 44135 USA. EM daniel.s.tyson@grc.nasa.gov; michael.a.meador@grc.nasa.gov RI Christensen, Jorn/J-8124-2012 NR 39 TC 8 Z9 8 U1 2 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1010-6030 J9 J PHOTOCH PHOTOBIO A JI J. Photochem. Photobiol. A-Chem. PD MAY 15 PY 2005 VL 172 IS 1 BP 97 EP 107 DI 10.1016/j.jphotochem.2004.11.012 PG 11 WC Chemistry, Physical SC Chemistry GA 925NJ UT WOS:000229059500012 ER PT J AU Ustinov, EA AF Ustinov, EA TI Atmospheric weighting functions and surface partial derivatives for remote sensing of scattering planetary atmospheres in thermal spectral region: general adjoint approach SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE adjoint sensitivity analysis; radiative transfer; remote sensing ID RADIATIVE-TRANSFER EQUATION; SENSITIVITY-ANALYSIS; TEMPERATURE; IR AB An approach to formulation of inversion algorithms for remote sensing in the thermal spectral region in the case of a scattering planetary atmosphere, based on the adjoint equation of radiative transfer (Ustinov (JQSRT 68 (2001) 195; JQSRT 73 (2002) 29); referred to as Papers 1 and 2, respectively, in the main text), is applied to the general case. of retrievals of atmospheric and surface parameters for the scattering atmosphere with nadir viewing geometry. Analytic expressions for corresponding weighting functions for atmospheric parameters and partial derivatives for surface parameters are derived. The case of pure atmospheric absorption with a scattering underlying, surface is considered and convergence to results obtained for the non-scattering atmospheres (Ustinov (JQSRT 74 (2002) 683), referred to as Paper 3 in the main text) is demonstrated. (C) 2004 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ustinov, EA (reprint author), CALTECH, Jet Prop Lab, Mail Stop 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM eugene.a.ustinov@jpl.nasa.gov RI Ustinov, Eugene/D-1350-2015 OI Ustinov, Eugene/0000-0003-0227-4286 NR 6 TC 11 Z9 11 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAY 15 PY 2005 VL 92 IS 3 BP 351 EP 371 DI 10.1016/j.jqsrt.2004.08.003 PG 21 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 893HK UT WOS:000226709700007 ER PT J AU Krieg, J Nothholt, J Mahieu, E Rinsland, CP Zander, R AF Krieg, J Nothholt, J Mahieu, E Rinsland, CP Zander, R TI Sulphur hexafluoride (SF6): comparison of FTIR-measurements at three sites and determination of its trend in the northern hemisphere SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE SF6; atmospheric trends; anthropogenic emissions; FTIR-spectrometry ID INFRARED SPECTROSCOPIC MEASUREMENTS; LOWER STRATOSPHERE; UPPER TROPOSPHERE; ABSORPTION; ABUNDANCE AB Fourier transform infrared spectrometry has been used to retrieve the total column abundances of SF6 at three locations in the northern hemisphere, i.e., the Ny- Angstromlesund site in Spitsbergen/Norway at 79degreesN, the Jungfraujoch observatory in Switzerland at 47degreesN and the Kitt Peak observatory in Arizona, USA, at 32degreesN. The total column results have been converted to average tropospheric mixing ratios. The mean increases in these mixing ratios have been found to be, equal to 0.31 +/- 0.08 pptv yr(-1) at Ny Angstromlesund, 0.24 +/- 0.01 pptv yr(-1) at the Jungfraujoch and 0.28 +/- 0.09 pptv yr(-1) at Kitt Peak for the common period March 1993 to March 2002, in agreement with corresponding CMDL data (0.21 +/- 0.0002 pptv yr(-1)) at the surface. The limited accuracy of the Ny Angstromlesund and Kitt Peak data results from strong tropospheric water vapour interferences at these lower altitude sites. Observations at all three locations show that SF6 is Still accumulating in the atmosphere. Extrapolations of linear and second-order fits to the Jungfraujoch data predict tropospheric mixing ratios of SF6, respectively equal to 16.4 +/- 0.5 and. 14.7 +/- 0.6 in 2050, and 28.2 +/- 0.9 and 22.2 +/- 10.8 pptv in 2100, significantly, lower than those reported in the literature so far. (C) 2004 Elsevier Ltd. All, rights reserved. C1 Univ Bremen, Dept Phys, D-28334 Bremen, Germany. Alfred Wegener Inst Polar & Marine Res, D-27568 Potsdam, Germany. Univ Liege, Inst Astrophys & Geophys, B-4000 Liege, Belgium. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Nothholt, J (reprint author), Univ Bremen, Dept Phys, D-28334 Bremen, Germany. EM notholt@uni-bremen.de OI Mahieu, Emmanuel/0000-0002-5251-0286 NR 32 TC 10 Z9 11 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAY 15 PY 2005 VL 92 IS 3 BP 383 EP 392 DI 10.1016/j.jqrst.2004.08.005 PG 10 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 893HK UT WOS:000226709700009 ER PT J AU Yu, N Salik, E Maleki, L AF Yu, N Salik, E Maleki, L TI Ultralow-noise mode-locked laser with coupled optoelectronic oscillator configuration SO OPTICS LETTERS LA English DT Article ID TO-DIGITAL CONVERTER; FIBER RING LASER; TIMING JITTER AB We describe simultaneous generation of ultralow-noise optical pulses and microwave signal with a mode-locked fiber laser in a coupled optoelectronic oscillator configuration. We demonstrate 9.2-GHz optical and microwave signals with the measured phase noise of -140 dBc/Hz at 10-kHz offset frequency. We show that the mode-locked laser in the photonic oscillator serves as a high-Q filter and is responsible for the observed low phase noise. (c) 2005 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yu, N (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM yu@jpl.nasa.gov NR 17 TC 42 Z9 42 U1 1 U2 12 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 MAY 15 PY 2005 VL 30 IS 10 BP 1231 EP 1233 DI 10.1364/OL.30.001231 PG 3 WC Optics SC Optics GA 924WO UT WOS:000229011800049 PM 15943318 ER PT J AU Choudhari, M Chang, CL Jiang, L AF Choudhari, M Chang, CL Jiang, L TI Towards transition modelling for supersonic laminar flow control based on spanwise periodic roughness elements SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT Workshop on New Developments and Application in Rapid Fluid Flows CY JUL 14-18, 2003 CL Durham Univ, Durham, ENGLAND HO Durham Univ DE laminar flow control; transition; receptivity; supersonic; crossflow ID PARABOLIZED STABILITY EQUATIONS; VORTICES; LAYER; RECEPTIVITY AB Laminar flow control (LFC) is one of the key enabling technologies for quiet and efficient supersonic aircraft. Recent work at Arizona State University (ASU) has led to a novel concept for passive LFC, which employs distributed leading edge roughness to limit the growth of naturally dominant crossflow instabilities in a swept-wing boundary layer. Predicated on nonlinear modification of the mean boundary-layer flow via controlled receptivity, the ASU concept requires a holistic prediction approach that accounts for all major stages within transition in an integrated manner. As a first step in developing an engineering methodology for the design and optimization of rougluiess-based supersonic LFC, this paper reports on canonical findings related to receptivity plus linear and nonlinear development of stationary crossflow, instabilities on a Mach 2.4, 73 degrees swept airfoil with a chord Reynolds number of 16.3 million. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Texas, Arlington, TX 76019 USA. RP Choudhari, M (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM meelan.m.choudhari@nasa.gov RI Choudhari, Meelan/F-6080-2017 OI Choudhari, Meelan/0000-0001-9120-7362 NR 27 TC 2 Z9 3 U1 0 U2 3 PU ROYAL SOCIETY PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T ROY SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD MAY 15 PY 2005 VL 363 IS 1830 BP 1079 EP 1096 DI 10.1098/rsta.2005.1551 PG 18 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 946TE UT WOS:000230594400005 PM 16105770 ER PT J AU Berterretche, M Hudak, AT Cohen, WB Maiersperger, TK Gower, ST Dungan, J AF Berterretche, M Hudak, AT Cohen, WB Maiersperger, TK Gower, ST Dungan, J TI Comparison of regression and geostatistical methods for mapping Leaf Area Index (LAI) with Landsat ETM+ data over a boreal forest SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE conditional simulation; Kriging; reduced major axis regression ID NET PRIMARY PRODUCTION; TEMPERATE CONIFEROUS FORESTS; ECOSYSTEM PROCESSES; THEMATIC MAPPER; SAMPLING DESIGN; SATELLITE DATA; VEGETATION; CANOPY; LANDSCAPE; TM AB This study compared aspatial and spatial methods of using remote sensing and field data to predict maximum growing season leaf area index (LAI) maps in a boreal forest in Manitoba, Canada. The methods tested were orthogonal regression analysis (reduced major axis, RMA) and two geostatistical techniques: kriging with an external drift (KED) and sequential Gaussian conditional simulation (SGCS). Deterministic methods such as RMA and KED provide a single predicted map with either aspatial (e.g., standard error, in regression techniques) or limited spatial (e.g., KED variance) assessments of errors, respectively. In contrast, SGCS takes a probabilistic approach, where simulated values are conditional on the sample values and preserve the sample statistics. In this application, canonical indices were used to maximize the ability of Landsat ETM+ spectral data to account for LAI variability measured in the field through a spatially nested sampling design. As expected based on theory, SGCS did the best job preserving the distribution of measured LAI values. In terms of spatial pattern, SGCS preserved the anisotropy observed in semivariograms of measured LAI, while KED reduced anisotropy and lowered global variance (i.e., lower sill), also consistent with theory. The conditional variance of multiple SGCS realizations provided a useful visual and quantitative measure of spatial uncertainty. For applications requiring spatial prediction methods, we concluded KED is more useful if local accuracy is important, but SGCS is better for indicating global pattern. Predicting LAI from satellite data using geostatistical methods requires a distribution and density of primary, reference LAI measurements that are impractical to obtain. For regional NPP modeling with coarse resolution inputs, the aspatial RMA regression method is the most practical option. Published by Elsevier Inc. C1 US Forest Serv, USDA, Rocky Mt Res Stn, Moscow, ID 83843 USA. Oregon State Univ, Dept Forest Sci, Corvallis, OR 97331 USA. US Forest Serv, USDA, Pacific NW Res Stn, Moscow, ID 83843 USA. Univ Wisconsin, Dept Forest Ecol & Management, Madison, WI 53706 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hudak, AT (reprint author), US Forest Serv, USDA, Rocky Mt Res Stn, 1221 S Main St, Moscow, ID 83843 USA. EM ahudak@fs.fed.us RI Dungan, Jennifer/G-9921-2016 OI Dungan, Jennifer/0000-0002-4863-1616 NR 61 TC 50 Z9 62 U1 3 U2 13 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 MAY 15 PY 2005 VL 96 IS 1 BP 49 EP 61 DI 10.1016/j.rse.2005.01.014 PG 13 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 929OJ UT WOS:000229355100004 ER PT J AU Gopalswamy, N Yashiro, S Michalek, G Xie, H Lepping, RP Howard, RA AF Gopalswamy, N Yashiro, S Michalek, G Xie, H Lepping, RP Howard, RA TI Solar source of the largest geomagnetic storm of cycle 23 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CORONAL MASS EJECTIONS; MAGNETIC CLOUDS; PROMINENCE; FIELDS AB The largest geomagnetic storm of solar cycle 23 occurred on 2003 November 20 with a Dst index of - 472 nT, due to a coronal mass ejection (CME) from active region 0501. The CME near the Sun had a sky-plane speed of similar to 1660 km/s, but the associated magnetic cloud ( MC) arrived with a speed of only 730 km/s. The MC at 1 AU ( ACE Observations) had a high magnetic field ( similar to 56 nT) and high inclination to the ecliptic plane. The southward component of the MC's magnetic field was made up almost entirely of its axial field because of its east-south-west (ESW) chirality. We suggest that the southward pointing strong axial field of the MC reconnected with Earth's front-side magnetic field, resulting in the largest storm of the solar cycle 23. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. USN, Res Lab, Washington, DC 20375 USA. RP Gopalswamy, N (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM gopals@fugee.gsfc.nasa.gov RI Gopalswamy, Nat/D-3659-2012 NR 18 TC 39 Z9 39 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 MAY 13 PY 2005 VL 32 IS 12 AR L12S09 DI 10.1029/2004GL021639 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 927QM UT WOS:000229211400001 ER PT J AU Mahesh, A Campbell, JR Spinhirne, JD AF Mahesh, A Campbell, JR Spinhirne, JD TI Multi-year measurements of cloud base heights at South Pole by lidar SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTIC PLATEAU; MICROPULSE LIDAR; RADIATION; NETWORK; CLIMATE AB The Micropulse Lidar Network has operated a full-time lidar measurement program at South Pole Station since 2000. Observations from this instrument are an important multi-year record of clouds over the Antarctic plateau. Earlier South Pole observations relied mostly on passive measurements to characterize clouds; the lidar's active profiles present an opportunity to validate current understanding of Antarctic clouds, as well as study properties that are not adequately captured in passive measurements. Lidar observations show clouds to be present roughly 40 percent of the time, and often appearing in wind-swept layers immediately above ground-based scattering layers such as blowing snow and suspended ice particles. There is very little indication of seasonal variability in cloud base heights; this contradicts earlier observations from an interferometer made in 1992 when it was determined that the distribution of cloud base heights in the summer months was different from that seen at other times. Those observations had also indicated that cloud base heights over the high plateau are distributed bimodally, with many near-surface clouds, and a second mode of other clouds well above the surface - based inversion. The lidar observations, however, suggest that this may be true only of the optically thicker clouds and even then only in the spring. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. RP Mahesh, A (reprint author), NASA, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. EM mahesh@agnes.gsfc.nasa.gov RI Campbell, James/C-4884-2012 OI Campbell, James/0000-0003-0251-4550 NR 21 TC 10 Z9 11 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 MAY 13 PY 2005 VL 32 IS 9 AR L09812 DI 10.1029/2004GL021983 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 927QK UT WOS:000229211200001 ER PT J AU Mitrescu, C Haynes, JM Stephens, GL Miller, SD Heymsfield, GM McGill, MJ AF Mitrescu, C Haynes, JM Stephens, GL Miller, SD Heymsfield, GM McGill, MJ TI Cirrus cloud optical, microphysical, and radiative properties observed during the CRYSTAL-FACE experiment: A lidar-radar retrieval system SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ICE PARTICLE DENSITIES; MILLIMETER-WAVE RADAR; WATER-CONTENT; AIRCRAFT; ATMOSPHERE; FEEDBACK; DEPTH; MODEL; SIZE AB [1] A method of retrieving cloud microphysical properties using combined observations from both cloud radar and lidar is introduced. The description of the lidar-radar model accounts for nonspherical effects of the ice crystals, with a treatment for multiple scattering and Mie effects. This retrieval makes use of an improvement to the traditional optimal estimation retrieval method, whereby a series of corrections are applied to the state vector during the search for an iterative solution. This allows faster convergence to a solution and is less processor intensive. The retrieval method is applied to radar and lidar observations from the CRYSTAL-FACE experiment, and vertical profiles of ice crystal characteristic diameter, number concentration, and ice water content are retrieved for a cirrus cloud layer observed 1 day of that experiment. Empirical relationships between ice water content and radar reflectivity as well as between particle number concentrations and characteristic diameter are also examined. The results indicate that a distinct and robust relationship exists between the latter two parameters, offering insight into the nature of cirrus microphysical processes. C1 USN, Marine Meteorol Div, Satellite Meteorol Applicat Sect, Res Lab, Monterey, CA 93943 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mitrescu, C (reprint author), USN, Marine Meteorol Div, Satellite Meteorol Applicat Sect, Res Lab, 7 Grace Hopper Ave,MS 2, Monterey, CA 93943 USA. EM mitrescu@nrlmry.navy.mil; haynes@atmos.colostate.edu; stephens@atmos.colostate.edu; miller@nrlmry.navy.mil; gerald.heymsfield@nasa.gov; mcgill@virl.gsfc.nasa.gov RI McGill, Matthew/D-8176-2012 NR 43 TC 9 Z9 9 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 MAY 13 PY 2005 VL 110 IS D9 AR D09208 DI 10.1029/2004JD005605 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 927QO UT WOS:000229211700003 ER PT J AU Abbott, B Abbott, R Adhikari, R Ageev, A Allen, B Amin, R Anderson, SB Anderson, WG Araya, M Armandula, H Ashley, M Asiri, F Aufmuth, P Aulbert, C Babak, S Balasubramanian, R Ballmer, S Barish, BC Barker, C Barker, D Barnes, M Barr, B Barton, MA Bayer, K Beausoleil, R Belczynski, K Bennett, R Berukoff, SJ Betzwieser, J Bhawal, B Bilenko, IA Billingsley, G Black, E Blackburn, K Blackburn, L Bland, B Bochner, B Bogue, L Bork, R Bose, S Brady, PR Braginsky, VB Brau, JE Brown, DA Bullington, A Bunkowski, A Buonanno, A Burgess, R Busby, D Butler, WE Byer, RL Cadonati, L Cagnoli, G Camp, JB Cantley, CA Cardenas, L Carter, K Casey, MM Castiglione, J Chandler, A Chapsky, J Charlton, P Chatterji, S Chelkowski, S Chen, Y Chickarmane, V Chin, D Christensen, N Churches, D Cokelaer, T Colacino, C Coldwell, R Coles, M Cook, D Corbitt, T Coyne, D Creighton, JDE Creighton, TD Crooks, DRM Csatorday, P Cusack, BJ Cutler, C D'Ambrosio, E Danzmann, K Daw, E DeBra, D Delker, T Dergachev, V DeSalvo, R Dhurandhar, S Di Credico, A Diaz, M Ding, H Drever, RWP Dupuis, RJ Edlund, JA Ehrens, P Elliffe, EJ Etzel, T Evans, M Evans, T Fairhurst, S Fallnich, C Farnham, D Fejer, MM Findley, T Fine, M Finn, LS Franzen, KY Freise, A Frey, R Fritschel, P Frolov, VV Fyffe, M Ganezer, KS Garofoli, J Giaime, JA Gillespie, A Goda, K Gonzalez, G Gossler, S Grandclement, P Grant, A Gray, C Gretarsson, AM Grimmett, D Grote, H Grunewald, S Guenther, M Gustafson, E Gustafson, R Hamilton, WO Hammond, M Hanson, J Hardham, C Harms, J Harry, G Hartunian, A Heefner, J Hefetz, Y Heinzel, G Heng, IS Hennessy, M Hepler, N Heptonstall, A Heurs, M Hewitson, M Hild, S Hindman, N Hoang, P Hough, J Hrynevych, M Hua, W Ito, M Itoh, Y Ivanov, A Jennrich, O Johnson, B Johnson, WW Johnston, WR Jones, DI Jones, L Jungwirth, D Kalogera, V Katsavounidis, E Kawabe, K Kawamura, S Kells, W Kern, J Khan, A Killbourn, S Killow, CJ Kim, C King, C King, P Klimenko, S Koranda, S Kotter, K Kovalik, J Kozak, D Krishnan, B Landry, M Langdale, J Lantz, B Lawrence, R Lazzarini, A Lei, M Leonor, I Libbrecht, K Libson, A Lindquist, P Liu, S Logan, J Lormand, M Lubinski, M Luck, H Lyons, TT Machenschalk, B MacInnis, M Mageswaran, M Mailand, K Majid, W Malec, M Mann, F Marin, A Marka, S Maros, E Mason, J Mason, K Matherny, O Matone, L Mavalvala, N McCarthy, R McClelland, DE McHugh, M McNabb, JWC Mendell, G Mercer, RA Meshkov, S Messaritaki, E Messenger, C Mitrofanov, VP Mitselmakher, G Mittleman, R Miyakawa, O Miyoki, S Mohanty, S Moreno, G Mossavi, K Mueller, G Mukherjee, S Murray, P Myers, J Nagano, S Nash, T Nayak, R Newton, G Nocera, F Noel, JS Nutzman, P Olson, T O'Reilly, B Ottaway, DJ Ottewill, A Ouimette, D Overmier, H Owen, BJ Pan, Y Papa, MA Parameshwaraiah, V Parameswariah, C Pedraza, M Penn, S Pitkin, M Plissi, M Prix, R Quetschke, V Raab, F Radkins, H Rahkola, R Rakhmanov, M Rao, SR Rawlins, K Ray-Majumder, S Re, V Redding, D Regehr, MW Regimbau, T Reid, S Reilly, KT Reithmaier, K Reitze, DH Richman, S Riesen, R Riles, K Rivera, B Rizzi, A Robertson, DI Robertson, NA Robison, L Roddy, S Rollins, J Romano, JD Romie, J Rong, H Rose, D Rotthoff, E Rowan, S Rudiger, A Russell, P Ryan, K Salzman, I Sandberg, V Sanders, GH Sannibale, V Sathyaprakash, B Saulson, PR Savage, R Sazonov, A Schilling, R Schlaufman, K Schmidt, V Schnabel, R Schofield, R Schutz, BF Schwinberg, P Scott, SM Seader, SE Searle, AC Sears, B Seel, S Seifert, F Sengupta, AS Shapiro, CA Shawhan, P Shoemaker, DH Shu, QZ Sibley, A Siemens, X Sievers, L Sigg, D Sintes, AM Smith, JR Smith, M Smith, MR Sneddon, PH Spero, R Stapfer, G Steussy, D Strain, KA Strom, D Stuver, A Summerscales, T Sumner, MC Sutton, PJ Sylvestre, J Takamori, A Tanner, DB Tariq, H Taylor, I Taylor, R Taylor, R Thorne, KA Thorne, KS Tibbits, M Tilav, S Tinto, M Tokmakov, KV Torres, C Torrie, C Traylor, G Tyler, W Ugolini, D Ungarelli, C Vallisneri, M van Putten, M Vass, S Vecchio, A Veitch, J Vorvick, C Vyachanin, SP Wallace, L Walther, H Ward, H Ware, B Watts, K Webber, D Weidner, A Weiland, U Weinstein, A Weiss, R Welling, H Wen, L Wen, S Whelan, JT Whitcomb, SE Whiting, BF Wiley, S Wilkinson, C Willems, PA Williams, PR Williams, R Willke, B Wilson, A Winjum, BJ Winkler, W Wise, S Wiseman, AG Woan, G Wooley, R Worden, J Wu, W Yakushin, I Yamamoto, H Yoshida, S Zaleski, KD Zanolin, M Zawischa, I Zhang, L Zhu, R Zotov, N Zucker, M Zweizig, J Kramer, M Lyne, AG AF Abbott, B Abbott, R Adhikari, R Ageev, A Allen, B Amin, R Anderson, SB Anderson, WG Araya, M Armandula, H Ashley, M Asiri, F Aufmuth, P Aulbert, C Babak, S Balasubramanian, R Ballmer, S Barish, BC Barker, C Barker, D Barnes, M Barr, B Barton, MA Bayer, K Beausoleil, R Belczynski, K Bennett, R Berukoff, SJ Betzwieser, J Bhawal, B Bilenko, IA Billingsley, G Black, E Blackburn, K Blackburn, L Bland, B Bochner, B Bogue, L Bork, R Bose, S Brady, PR Braginsky, VB Brau, JE Brown, DA Bullington, A Bunkowski, A Buonanno, A Burgess, R Busby, D Butler, WE Byer, RL Cadonati, L Cagnoli, G Camp, JB Cantley, CA Cardenas, L Carter, K Casey, MM Castiglione, J Chandler, A Chapsky, J Charlton, P Chatterji, S Chelkowski, S Chen, Y Chickarmane, V Chin, D Christensen, N Churches, D Cokelaer, T Colacino, C Coldwell, R Coles, M Cook, D Corbitt, T Coyne, D Creighton, JDE Creighton, TD Crooks, DRM Csatorday, P Cusack, BJ Cutler, C D'Ambrosio, E Danzmann, K Daw, E DeBra, D Delker, T Dergachev, V DeSalvo, R Dhurandhar, S Di Credico, A Diaz, M Ding, H Drever, RWP Dupuis, RJ Edlund, JA Ehrens, P Elliffe, EJ Etzel, T Evans, M Evans, T Fairhurst, S Fallnich, C Farnham, D Fejer, MM Findley, T Fine, M Finn, LS Franzen, KY Freise, A Frey, R Fritschel, P Frolov, VV Fyffe, M Ganezer, KS Garofoli, J Giaime, JA Gillespie, A Goda, K Gonzalez, G Gossler, S Grandclement, P Grant, A Gray, C Gretarsson, AM Grimmett, D Grote, H Grunewald, S Guenther, M Gustafson, E Gustafson, R Hamilton, WO Hammond, M Hanson, J Hardham, C Harms, J Harry, G Hartunian, A Heefner, J Hefetz, Y Heinzel, G Heng, IS Hennessy, M Hepler, N Heptonstall, A Heurs, M Hewitson, M Hild, S Hindman, N Hoang, P Hough, J Hrynevych, M Hua, W Ito, M Itoh, Y Ivanov, A Jennrich, O Johnson, B Johnson, WW Johnston, WR Jones, DI Jones, L Jungwirth, D Kalogera, V Katsavounidis, E Kawabe, K Kawamura, S Kells, W Kern, J Khan, A Killbourn, S Killow, CJ Kim, C King, C King, P Klimenko, S Koranda, S Kotter, K Kovalik, J Kozak, D Krishnan, B Landry, M Langdale, J Lantz, B Lawrence, R Lazzarini, A Lei, M Leonor, I Libbrecht, K Libson, A Lindquist, P Liu, S Logan, J Lormand, M Lubinski, M Luck, H Lyons, TT Machenschalk, B MacInnis, M Mageswaran, M Mailand, K Majid, W Malec, M Mann, F Marin, A Marka, S Maros, E Mason, J Mason, K Matherny, O Matone, L Mavalvala, N McCarthy, R McClelland, DE McHugh, M McNabb, JWC Mendell, G Mercer, RA Meshkov, S Messaritaki, E Messenger, C Mitrofanov, VP Mitselmakher, G Mittleman, R Miyakawa, O Miyoki, S Mohanty, S Moreno, G Mossavi, K Mueller, G Mukherjee, S Murray, P Myers, J Nagano, S Nash, T Nayak, R Newton, G Nocera, F Noel, JS Nutzman, P Olson, T O'Reilly, B Ottaway, DJ Ottewill, A Ouimette, D Overmier, H Owen, BJ Pan, Y Papa, MA Parameshwaraiah, V Parameswariah, C Pedraza, M Penn, S Pitkin, M Plissi, M Prix, R Quetschke, V Raab, F Radkins, H Rahkola, R Rakhmanov, M Rao, SR Rawlins, K Ray-Majumder, S Re, V Redding, D Regehr, MW Regimbau, T Reid, S Reilly, KT Reithmaier, K Reitze, DH Richman, S Riesen, R Riles, K Rivera, B Rizzi, A Robertson, DI Robertson, NA Robison, L Roddy, S Rollins, J Romano, JD Romie, J Rong, H Rose, D Rotthoff, E Rowan, S Rudiger, A Russell, P Ryan, K Salzman, I Sandberg, V Sanders, GH Sannibale, V Sathyaprakash, B Saulson, PR Savage, R Sazonov, A Schilling, R Schlaufman, K Schmidt, V Schnabel, R Schofield, R Schutz, BF Schwinberg, P Scott, SM Seader, SE Searle, AC Sears, B Seel, S Seifert, F Sengupta, AS Shapiro, CA Shawhan, P Shoemaker, DH Shu, QZ Sibley, A Siemens, X Sievers, L Sigg, D Sintes, AM Smith, JR Smith, M Smith, MR Sneddon, PH Spero, R Stapfer, G Steussy, D Strain, KA Strom, D Stuver, A Summerscales, T Sumner, MC Sutton, PJ Sylvestre, J Takamori, A Tanner, DB Tariq, H Taylor, I Taylor, R Taylor, R Thorne, KA Thorne, KS Tibbits, M Tilav, S Tinto, M Tokmakov, KV Torres, C Torrie, C Traylor, G Tyler, W Ugolini, D Ungarelli, C Vallisneri, M van Putten, M Vass, S Vecchio, A Veitch, J Vorvick, C Vyachanin, SP Wallace, L Walther, H Ward, H Ware, B Watts, K Webber, D Weidner, A Weiland, U Weinstein, A Weiss, R Welling, H Wen, L Wen, S Whelan, JT Whitcomb, SE Whiting, BF Wiley, S Wilkinson, C Willems, PA Williams, PR Williams, R Willke, B Wilson, A Winjum, BJ Winkler, W Wise, S Wiseman, AG Woan, G Wooley, R Worden, J Wu, W Yakushin, I Yamamoto, H Yoshida, S Zaleski, KD Zanolin, M Zawischa, I Zhang, L Zhu, R Zotov, N Zucker, M Zweizig, J Kramer, M Lyne, AG CA LIGO Sci Collaboration TI Limits on gravitational-wave emission from selected pulsars using LIGO data SO PHYSICAL REVIEW LETTERS LA English DT Article AB We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10(-24). These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10(-5) for the four closest pulsars. C1 CALTECH, LIGO, Pasadena, CA 91125 USA. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-30167 Hannover, Germany. Australian Natl Univ, Canberra, ACT 0200, Australia. Calif State Univ Dominguez Hills, Carson, CA 90747 USA. CALTECH, CaRT, Pasadena, CA 91125 USA. Cardiff Univ, Cardiff CF2 3YB, S Glam, Wales. Carleton Coll, Northfield, MN 55057 USA. Hobart & William Smith Coll, Geneva, NY 14456 USA. Interuniv Ctr Astron & Astrophys, Pune 411007, Maharashtra, India. MIT, LIGO, Cambridge, MA 02139 USA. LIGO Hanford Observ, Richland, WA 99352 USA. LIGO Livingston Observ, Livingston, LA 70754 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Loyola Univ, New Orleans, LA 70118 USA. Max Planck Inst Quantum Opt, D-85748 Garching, Germany. Moscow MV Lomonosov State Univ, Moscow 119992, Russia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Astron Observ Japan, Tokyo 1818588, Japan. Northwestern Univ, Evanston, IL 60208 USA. Salish Kootenai Coll, Pablo, MT 59855 USA. SE Louisiana Univ, Hammond, LA 70402 USA. Stanford Univ, Stanford, CA 94305 USA. Syracuse Univ, Syracuse, NY 13244 USA. Penn State Univ, University Pk, PA 16802 USA. Univ Texas, Brownsville, TX 78520 USA. Texas Southmost Coll, Brownsville, TX 78520 USA. Trinity Univ, San Antonio, TX 78212 USA. Leibniz Univ Hannover, D-30167 Hannover, Germany. Univ Illes Balears, E-07122 Palma de Mallorca, Spain. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Univ Florida, Gainesville, FL 32611 USA. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Rochester, Rochester, NY 14627 USA. Univ Wisconsin, Milwaukee, WI 53201 USA. Washington State Univ, Pullman, WA 99164 USA. Univ Manchester, Jodrell Bank Observ, Macclesfield SK11 9DL, Cheshire, England. RP CALTECH, LIGO, Pasadena, CA 91125 USA. RI Vecchio, Alberto/F-8310-2015; Ottaway, David/J-5908-2015; Ottewill, Adrian/A-1838-2016; Messaritaki, Eirini/D-7393-2016; Sigg, Daniel/I-4308-2015; Harms, Jan/J-4359-2012; Frey, Raymond/E-2830-2016; Sylvestre, Julien/A-8610-2009; Beausoleil, Raymond/C-5076-2009; Lueck, Harald/F-7100-2011; McClelland, David/E-6765-2010; 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; Finn, Lee Samuel/A-3452-2009; Raab, Frederick/E-2222-2011; Freise, Andreas/F-8892-2011; Kawabe, Keita/G-9840-2011; 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; Pitkin, Matthew/I-3802-2013; Ivanov, Andrew/A-7982-2013; Liu, Sheng/K-2815-2013; Vyatchanin, Sergey/J-2238-2012; van Putten, Maurice/F-5237-2011; OI Vecchio, Alberto/0000-0002-6254-1617; Ottewill, Adrian/0000-0003-3293-8450; Sigg, Daniel/0000-0003-4606-6526; Frey, Raymond/0000-0003-0341-2636; Whelan, John/0000-0001-5710-6576; Cokelaer, Thomas/0000-0001-6286-1138; Sylvestre, Julien/0000-0001-8136-4348; Lueck, Harald/0000-0001-9350-4846; McClelland, David/0000-0001-6210-5842; Strain, Kenneth/0000-0002-2066-5355; Finn, Lee Samuel/0000-0002-3937-0688; Allen, Bruce/0000-0003-4285-6256; Pitkin, Matthew/0000-0003-4548-526X; Ivanov, Andrew/0000-0002-9270-5643; Zweizig, John/0000-0002-1521-3397; Fairhurst, Stephen/0000-0001-8480-1961; Taylor, Ian/0000-0001-5040-0772; Aulbert, Carsten/0000-0002-1481-8319; Veitch, John/0000-0002-6508-0713; Papa, M.Alessandra/0000-0002-1007-5298 NR 10 TC 96 Z9 97 U1 1 U2 7 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 MAY 13 PY 2005 VL 94 IS 18 AR 181103 DI 10.1103/PhysRevLett.94.181103 PG 6 WC Physics, Multidisciplinary SC Physics GA 925ST UT WOS:000229074300009 PM 15904354 ER PT J AU Mahaffy, PR AF Mahaffy, PR TI Intensive Titan exploration begins SO SCIENCE LA English DT Article ID SATURNIAN SYSTEM AB The Cassini Orbiter spacecraft first skimmed through the tenuous upper atmosphere of Titan on 26 October 2004. This moon of Saturn is unique in our solar system, with a dense nitrogen atmosphere that is cold enough in places to rain methane, the feedstock for the atmospheric chemistry that produces hydrocarbons, nitrite compounds, and Titan's orange haze. The data returned from this flyby supply new information on the magnetic field and plasma environment around Titan, expose new facets of the dynamics and chemistry of Titan's atmosphere, and provide the first glimpses of what appears to be a complex, fluid-processed, geologically young Titan surface. C1 NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP Mahaffy, PR (reprint author), NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Code 661, Greenbelt, MD 20771 USA. EM paul.r.mahaffy@nasa.gov RI Mahaffy, Paul/E-4609-2012 NR 12 TC 15 Z9 16 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 MAY 13 PY 2005 VL 308 IS 5724 BP 969 EP 970 DI 10.1126/science.1113205 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 927JR UT WOS:000229190700030 PM 15890870 ER PT J AU Elachi, C Wall, S Allison, M Anderson, Y Boehmer, R Callahan, P Encrenaz, P Flamini, E Franceschetti, G Gim, Y Hamilton, G Hensley, S Janssen, M Johnson, W Kelleher, K Kirk, R Lopes, R Lorenz, R Lunine, J Muhleman, D Ostro, S Paganelli, F Picardi, G Posa, F Roth, L Seu, R Shaffer, S Soderblom, L Stiles, B Stofan, E Vetrella, S West, R Wood, C Wye, L Zebker, H AF Elachi, C Wall, S Allison, M Anderson, Y Boehmer, R Callahan, P Encrenaz, P Flamini, E Franceschetti, G Gim, Y Hamilton, G Hensley, S Janssen, M Johnson, W Kelleher, K Kirk, R Lopes, R Lorenz, R Lunine, J Muhleman, D Ostro, S Paganelli, F Picardi, G Posa, F Roth, L Seu, R Shaffer, S Soderblom, L Stiles, B Stofan, E Vetrella, S West, R Wood, C Wye, L Zebker, H TI Cassini radar views the surface of Titan SO SCIENCE LA English DT Article ID SATELLITES; GANYMEDE AB The Cassini Titan Radar Mapper imaged about 1% of Titan's surface at a resolution of &SIM; 0.5 kilometer, and larger areas of the globe in lower resolution modes. The images reveal a complex surface, with areas of low relief and a variety of geologic features suggestive of dome-like volcanic constructs, flows, and sinuous channels. The surface appears to be young, with few impact craters. Scattering and dielectric properties are consistent with porous ice or organics. Dark patches in the radar images show high brightness temperatures and high emissivity and are consistent with frozen hydrocarbons. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Observ Paris, F-75014 Paris, France. Agenzia Spaziale Italiana, I-00198 Rome, Italy. Fac Ingn, I-80125 Naples, Italy. US Geol Survey, Flagstaff, AZ 86001 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Roma La Sapienza, I-00184 Rome, Italy. Politecn Bari, INFM, I-70126 Bari, Italy. Politecn Bari, Dipartimento Interateneo Fis, I-70126 Bari, Italy. Proxemy Res, Laytonsville, MD 20882 USA. Planetary Sci Inst, Tucson, AZ 85719 USA. Stanford Univ, Stanford, CA 94305 USA. RP Wall, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM steve.wall@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 27 TC 158 Z9 160 U1 2 U2 18 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 MAY 13 PY 2005 VL 308 IS 5724 BP 970 EP 974 DI 10.1126/science.1109919 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 927JR UT WOS:000229190700031 PM 15890871 ER PT J AU Flasar, FM Achterberg, RK Conrath, BJ Gierasch, PJ Kunde, VG Nixon, CA Bjoraker, GL Jennings, DE Romani, PN Simon-Miller, AA Bezard, B Coustenis, A Irwin, PGJ Teanby, NA Brasunas, J Pearl, JC Segura, ME Carlson, RC Mamoutkine, A Schinder, PJ Barucci, A Courtin, R Fouchet, T Gautier, D Lellouch, E Marten, A Prange, R Vinatier, S Strobel, DF Calcutt, SB Read, PL Taylor, FW Bowles, N Samuelson, RE Orton, GS Spilker, LJ Owen, TC Spencer, JR Showalter, MR Ferrari, C Abbas, MM Raulin, F Edgington, S Ade, P Wishnow, EH AF Flasar, FM Achterberg, RK Conrath, BJ Gierasch, PJ Kunde, VG Nixon, CA Bjoraker, GL Jennings, DE Romani, PN Simon-Miller, AA Bezard, B Coustenis, A Irwin, PGJ Teanby, NA Brasunas, J Pearl, JC Segura, ME Carlson, RC Mamoutkine, A Schinder, PJ Barucci, A Courtin, R Fouchet, T Gautier, D Lellouch, E Marten, A Prange, R Vinatier, S Strobel, DF Calcutt, SB Read, PL Taylor, FW Bowles, N Samuelson, RE Orton, GS Spilker, LJ Owen, TC Spencer, JR Showalter, MR Ferrari, C Abbas, MM Raulin, F Edgington, S Ade, P Wishnow, EH TI Titan's atmospheric temperatures, winds, and composition SO SCIENCE LA English DT Article ID HETERODYNE OBSERVATIONS; VERTICAL PROFILE; POLAR VORTEX; PHOTOCHEMISTRY; OCCULTATION; STRATOSPHERE; MILLIMETER; CHEMISTRY; DYNAMICS; SYSTEM AB Temperatures obtained from early Cassini infrared observations of Titan show a stratopause at an altitude of 310 kilometers (and 186 kelvin at 15 degrees S). Stratospheric temperatures are coldest in the winter northern hemisphere, with zonal winds reaching 160 meters per second. The concentrations of several stratospheric organic compounds are enhanced at mid- and high northern latitudes, and the strong zonal winds may, inhibit mixing between these latitudes and the rest of Titan. Above the south pole, temperatures in the stratosphere are 4 to 5 kelvin cooler than at the equator. The stratospheric mole fractions of methane and carbon monoxide are (1.6 +/- 0.5) x 10(-2) and (4.5 +/- 1.5) x 10(-5), respectively. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat, Lanham, MD 20706 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Observ Paris, LESIA, CNRS, UMR 8109, F-91925 Meudon, France. Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. QSS Grp, Lanham, MD 20706 USA. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. Search Extraterr Intelligence Inst, Mountain View, CA 94043 USA. CEA, Serv Astrophys, F-91191 Gif Sur Yvette, France. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Paris 07, Lab Interuniv Syst Atmospher, CNRS, UMR 7583, F-94010 Creteil, France. Univ Paris 12, Lab Interuniv Syst Atmospher, CNRS, UMR 7583, F-94010 Creteil, France. Univ Cardiff, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Space Sci Lab, Livermore, CA 94551 USA. RP Flasar, FM (reprint author), NASA, Goddard Space Flight Ctr, Code 693, Greenbelt, MD 20771 USA. EM f.m.flasar@nasa.gov RI Nixon, Conor/A-8531-2009; Flasar, F Michael/C-8509-2012; Romani, Paul/D-2729-2012; Bjoraker, Gordon/D-5032-2012; Jennings, Donald/D-7978-2012; brasunas, john/I-2798-2013; Simon, Amy/C-8020-2012; Ferrari, Cecile/P-9735-2016; Fouchet, Thierry/C-6374-2017; OI Nixon, Conor/0000-0001-9540-9121; Simon, Amy/0000-0003-4641-6186; Ferrari, Cecile/0000-0001-5962-7439; Fouchet, Thierry/0000-0001-9040-8285; Calcutt, Simon/0000-0002-0102-3170; Teanby, Nicholas/0000-0003-3108-5775; Irwin, Patrick/0000-0002-6772-384X NR 33 TC 231 Z9 232 U1 2 U2 31 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 MAY 13 PY 2005 VL 308 IS 5724 BP 975 EP 978 DI 10.1126/science.1111150 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 927JR UT WOS:000229190700032 PM 15894528 ER PT J AU Shemansky, DE Stewart, AIF West, RA Esposito, LW Hallett, JT Liu, XM AF Shemansky, DE Stewart, AIF West, RA Esposito, LW Hallett, JT Liu, XM TI The Cassini UVIS stellar probe of the Titan atmosphere SO SCIENCE LA English DT Article ID PHOTOABSORPTION CROSS-SECTIONS; VACUUM ULTRAVIOLET; ABSORPTION; METHANE; TEMPERATURE; PHOTOCHEMISTRY; THERMOSPHERE; SPECTROSCOPY; ACETYLENE; SPECTRA AB The Cassini Ultraviolet Imaging Spectrometer (UVIS) observed the extinction of photons from two stars by the atmosphere of Titan during the Titan flyby. Six species were identified and measured: methane, acetylene, ethylene, ethane, diacetylene, and hydrogen cyanide. The observations cover altitudes from 450 to 1600 kilometers above the surface. A mesopause is inferred from extraction of the temperature structure of methane, located at 615 km with a temperature minimum of 114 kelvin. The asymptotic kinetic temperature at the top of the atmosphere determined from this experiment is 151 kelvin. The higher order hydrocarbons and hydrogen cyanide peak sharply in abundance and are undetectable below altitudes ranging from 750 to 600 km, leaving methane as the only identifiable carbonaceous molecule in this experiment below 600 km. C1 Univ So Calif, Dept Aerosp Engn, Los Angeles, CA 90089 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Univ So Calif, Dept Aerosp Engn, Univ Pk, Los Angeles, CA 90089 USA. EM dons@hippolyta.usc.edu NR 31 TC 91 Z9 91 U1 4 U2 11 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 MAY 13 PY 2005 VL 308 IS 5724 BP 978 EP 982 DI 10.1126/science.1111790 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 927JR UT WOS:000229190700033 PM 15890872 ER PT J AU Waite, JH Niemann, H Yelle, RV Kasprzak, WT Cravens, TE Luhmann, JG McNutt, RL Ip, WH Gell, D De La Haye, V Muller-Wordag, I Magee, B Borggren, N Ledvina, S Fletcher, G Walter, E Miller, R Scherer, S Thorpe, R Xu, J Block, B Arnett, K AF Waite, JH Niemann, H Yelle, RV Kasprzak, WT Cravens, TE Luhmann, JG McNutt, RL Ip, WH Gell, D De La Haye, V Muller-Wordag, I Magee, B Borggren, N Ledvina, S Fletcher, G Walter, E Miller, R Scherer, S Thorpe, R Xu, J Block, B Arnett, K TI Ion Neutral Mass Spectrometer results from the first flyby of Titan SO SCIENCE LA English DT Article ID ISOTOPIC FRACTIONATION; ATMOSPHERE; NITROGEN; ORIGIN; TEMPERATURE; C-12/C-13; CLATHRATE; METHANE; HCN AB The Cassini Ion Neutral Mass Spectrometer (INMS) has obtained the first in situ composition measurements of the neutral densities of molecular nitrogen, methane, molecular hydrogen, argon, and a host of stable carbon-nitrile compounds in Titan's upper atmosphere. INMS in situ mass spectrometry has also provided evidence for atmospheric waves in the upper atmosphere and the first direct measurements of isotopes of nitrogen, carbon, and argon, which reveal interesting clues about the evolution of the atmosphere. The bulk composition and thermal structure of the moon's upper atmosphere do not appear to have changed considerably since the Voyager 1 flyby. C1 Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Natl Cent Univ, Inst Astron, Chungli 32054, Taiwan. Univ London Imperial Coll Sci Technol & Med, Space & Atmospher Phys Grp, London SW7 2BW, England. SW Res Inst, San Antonio, TX 78228 USA. RP Waite, JH (reprint author), Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. RI McNutt, Ralph/E-8006-2010 OI McNutt, Ralph/0000-0002-4722-9166 NR 28 TC 272 Z9 273 U1 2 U2 16 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 MAY 13 PY 2005 VL 308 IS 5724 BP 982 EP 986 DI 10.1126/science.1110652 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 927JR UT WOS:000229190700034 PM 15890873 ER EF