FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Pian, E Romano, P Treves, A Ghisellini, G Covino, S Cucchiara, A Dolcini, A Tagliaferri, G Markwardt, C Campana, S Chincarini, G Gehrels, N Giommi, P Maraschi, L Vergani, SD Zerbi, FM Molinari, E Testa, V Tosti, G Vitali, F Antonelli, LA Conconi, P Malaspina, G Nicastro, L Palazzi, E Meurs, EJA Norci, L AF Pian, E. Romano, P. Treves, A. Ghisellini, G. Covino, S. Cucchiara, A. Dolcini, A. Tagliaferri, G. Markwardt, C. Campana, S. Chincarini, G. Gehrels, N. Giommi, P. Maraschi, L. Vergani, S. D. Zerbi, F. M. Molinari, E. Testa, V. Tosti, G. Vitali, F. Antonelli, L. A. Conconi, P. Malaspina, G. Nicastro, L. Palazzi, E. Meurs, E. J. A. Norci, L. TI Simultaneous SWIFT and REM monitoring of the blazar PKS 0537-441 in 2005 SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : individual (PKS 0537-441); galaxies : active; gamma rays : observations; radiation mechanisms : nonthermal ID BL-LACERTAE OBJECTS; ACTIVE GALACTIC NUCLEI; GAMMA-RAY EMISSION; INTERNAL SHOCKS; PARTICLE-ACCELERATION; INFRARED OBSERVATIONS; PKS 0537-441; TELESCOPE; ENERGY; VARIABILITY AB The blazar PKS 0537-441 has been observed with all instruments of the Swift satellite between the end of 2004 and 2005 November. The BAT monitored it recurrently for a total of 2.7 Ms, and the XRT and UVOT pointed it on seven occasions for a total of 67 k. The automatic optical and near-infrared telescope REM has monitored simultaneously the source at all times. In 2005 January-February, PKS 0537-441 was detected at its brightest in optical and X-rays: more than a factor of 2 brighter in X-rays and about a factor of 60 brighter in the optical than observed in 2004 December. The 2005 July observation recorded a fainter X-ray state, albeit still brighter than the historical average. The simultaneous optical state is comparable to the one recorded in early 2005 January, before the outburst. In 2005 November, the source subsided both in X-rays and optical to a quiescent state. The optical and X-ray variations are well correlated, with no measurable time lag larger than about 1 month. On intraday timescales there is no obvious correlation between X-ray and optical variations, but the former tend to be more pronounced, opposite to what is observed on monthly timescales. The widely different amplitude of the long-term variability in optical and X-rays is very unusual. The spectral energy distributions are interpreted in terms of the synchrotron and inverse Compton mechanisms within a jet where the plasma radiates via internal shocks and the dissipation depends on the distance of the emitting region from the central engine. C1 Osserv Astron Trieste, INAF, I-34143 Trieste, Italy. Brera Astron Observ, INAF, I-23807 Merate, LC, Italy. Univ Milano Bicocca, Dept Phys, I-20126 Milan, Italy. Univ Insubria, Dept Math & Phys, I-22100 Como, Italy. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. ASDC, ESRIN, ASI Sci Data Ctr, I-00044 Frascati, Italy. Brera Astron Observ, INAF, I-20121 Milan, Italy. DIAS, Dunsink Observ, Dublin 15, Ireland. Dublin City Univ, Sch Phys Sci, Dublin 9, Ireland. Dublin City Univ, NCPST, Dublin 9, Ireland. Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. Univ Perugia, Dept Phys, I-06100 Perugia, Italy. Inst Space Astron & Cosm Phys, INAF, I-40129 Bologna, Italy. RP Pian, E (reprint author), Osserv Astron Trieste, INAF, I-34143 Trieste, Italy. RI Gehrels, Neil/D-2971-2012; Tosti, Gino/E-9976-2013; Nicastro, Luciano/F-5866-2015; Palazzi, Eliana/N-4746-2015; OI Tagliaferri, Gianpiero/0000-0003-0121-0723; Nicastro, Luciano/0000-0001-8534-6788; Vitali, Fabrizio/0000-0001-8332-4227; Campana, Sergio/0000-0001-6278-1576; Molinari, Emilio/0000-0002-1742-7735; giommi, paolo/0000-0002-2265-5003; Palazzi, Eliana/0000-0002-8691-7666; Zerbi, Filippo Maria/0000-0002-9996-973X; Covino, Stefano/0000-0001-9078-5507; Testa, Vincenzo/0000-0003-1033-1340; Pian, Elena/0000-0001-8646-4858 NR 50 TC 15 Z9 15 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 JUL 20 PY 2007 VL 664 IS 1 BP 106 EP 116 DI 10.1086/518469 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189QA UT WOS:000248002400011 ER PT J AU Sehgal, N Trac, H Huffenberger, K Bode, P AF Sehgal, Neelima Trac, Hy Huffenberger, Kevin Bode, Paul TI Microwave sky simulations and projections for galaxy cluster detection with the atacama cosmology telescope SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; galaxies : clusters : general; intergalactic medium ID SUNYAEV-ZELDOVICH CLUSTERS; PROBE WMAP OBSERVATIONS; TREE PARTICLE-MESH; X-RAY-PROPERTIES; DARK ENERGY; PLANCK MISSION; POWER SPECTRUM; MASS FUNCTION; MAPS; EVOLUTION AB We study the ability of three-frequency, arcminute-resolution microwave measurements to detect galaxy clusters via their Sunyaev-Zel'dovich (SZ) distortion of the microwave background. For this purpose, we have constructed large-area simulations of the microwave sky, and we have made them publicly available to further investigations into optimal data reduction techniques for upcoming SZ cluster surveys. In these sky simulations, galaxy clusters are modeled using N-body simulated dark matter halos plus a gas prescription for the intracluster medium that allows the small-scale cluster physics such as star formation and feedback to be realistically incorporated. We also model the primary microwave background, radio and infrared point sources, galactic dust emission, and the SZ flux including kinetic and relativistic contributions. We make use of these simulations to study the scaling relation between integrated SZ flux and cluster mass and find that our clusters follow a power law with an index that is steeper than that for self-similar cluster models. Some evolution of the power-law index and normalization with redshift is also observed. These simulations are also used to study cluster detection for the Atacama Cosmology Telescope (ACT). Using a multifrequency Wiener filter to separate clusters from other microwave components, we find that ACT alone can recover a cluster sample that is approximate to 90% complete and approximate to 85% pure above 3 x 10(14) M-circle dot. C1 Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91109 USA. RP Sehgal, N (reprint author), Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. RI Trac, Hy/N-8838-2014; OI Trac, Hy/0000-0001-6778-3861; Huffenberger, Kevin/0000-0001-7109-0099 NR 71 TC 29 Z9 29 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 JUL 20 PY 2007 VL 664 IS 1 BP 149 EP 161 DI 10.1086/518880 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189QA UT WOS:000248002400015 ER PT J AU Yukita, M Swartz, DA Soria, R Tennant, AF AF Yukita, Mihoko Swartz, Douglas A. Soria, Roberto Tennant, Allyn F. TI Discovery of a transient X-ray source in the compact stellar nucleus of NGC 2403 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : individual (NGC 2403); galaxies : nuclei; galaxies : star clusters; X-rays : binaries; X-rays : galaxies ID SUPERMASSIVE BLACK-HOLES; LARGE-MAGELLANIC-CLOUD; SPACE-TELESCOPE CENSUS; SPIRAL GALAXY NGC-2403; STAR-CLUSTERS; GLOBULAR-CLUSTERS; DWARF GALAXY; NGC 4395; M33; MASS AB We report the discovery of an X- ray source coincident with the nuclear star cluster at the dynamical center of the nearby late-type spiral galaxy NGC 2403. The X-ray luminosity of this source varies from below detection levels, similar to 1035 erg s(-1) in the 0.5-8.0 keV band to 7 x 10(38) erg s(-1) on timescales between observations of <2 months. The X-ray spectrum is well fit by an accretion disk model consisting of multiple blackbody components and corresponding physically to a compact object mass of greater than or similar to 5 M-circle dot. No pulsations nor aperiodic behavior is evident in its X- ray light curve on the short timescales of the individual observations. The X-ray properties of the source are more similar to those of the nuclear source X-8 in M33, believed to be a low-mass X-ray binary, then to those of the low-luminosity active galactic nucleus (AGN) in NGC 4395. The brightness of the nuclear star cluster, M-I similar to - 11: 8 mag, is typical of clusters in late-type spirals but its effective radius, r(e) similar to 12 pc, is several times larger than average indicating a relatively relaxed cluster and a low probability of a central massive object. Estimating from its observed colors and brightness, the cluster has a mass of greater than or similar to 10(6.5) M-circle dot and an age of similar to 1.4 Gyr. C1 Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. RP Yukita, M (reprint author), Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RI Yukita, Mihoko/E-4135-2017 NR 61 TC 7 Z9 7 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 JUL 20 PY 2007 VL 664 IS 1 BP 277 EP 283 DI 10.1086/518237 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189QA UT WOS:000248002400023 ER PT J AU Wisniewski, JP Bjorkman, KS Magalhaes, AM Pereyra, A AF Wisniewski, John P. Bjorkman, Karen S. Magalhaes, Antonio M. Pereyra, Antonio TI The magnetic field structure of the LMC 2 supershell: NGC 2100 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : bubbles; ISM : magnetic fields; Magellanic Clouds; open clusters and associations : individual (NGC 2100); techniques : polarimetric ID LARGE-MAGELLANIC-CLOUD; IRAS VELA SHELL; GRAIN ALIGNMENT; INTERSTELLAR GRAINS; RADIATIVE TORQUES; YOUNG CLUSTERS; POLARIZATION; POLARIMETRY; CIRCUMSTELLAR; SUPERBUBBLES AB We present UBVRI imaging polarimetry of NGC 2100 and its surrounding environment, which comprise a part of the LMC 2 supershell. The morphology of the observed position angle distribution provides a tracer of the projected magnetic field in this environment. Our polarization maps detail regions exhibiting similarly aligned polarization position angles, as well as more complex position angle patterns. We observe regions of coherent fields on spatial scales of 42; 24 to 104; 83 pc, and infer projected field strengths of similar to 14-30 mu G. We propose that the superposition of global outflows from the LMC 2 environment, as well as outflows created within NGC 2100, produce the unique field geometry in the region. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Toledo, Dept Phys & Astron, Ritter Observ, Toledo, OH 43606 USA. Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-01060970 Sao Paulo, Brazil. RP Wisniewski, JP (reprint author), NASA, Goddard Space Flight Ctr, Code 667, Greenbelt, MD 20771 USA. RI Magalhaes, Antonio Mario/K-9532-2013; Pereyra, Antonio/E-4547-2013 NR 50 TC 6 Z9 6 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 JUL 20 PY 2007 VL 664 IS 1 BP 296 EP 303 DI 10.1086/519155 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189QA UT WOS:000248002400025 ER PT J AU Immler, S Brown, PJ Milne, P Dessart, L Mazzali, PA Landsman, W Gehrels, N Petre, R Burrows, DN Nousek, JA Chevalier, RA Williams, CL Koss, M Stockdale, CJ Kelley, MT Weiler, KW Holland, ST Pian, E Roming, PWA Pooley, D Nomoto, K Greiner, J Campana, S Soderberg, AM AF Immler, S. Brown, P. J. Milne, P. Dessart, L. Mazzali, P. A. Landsman, W. Gehrels, N. Petre, R. Burrows, D. N. Nousek, J. A. Chevalier, R. A. Williams, C. L. Koss, M. Stockdale, C. J. Kelley, M. T. Weiler, K. W. Holland, S. T. Pian, E. Roming, P. W. A. Pooley, D. Nomoto, K. Greiner, J. Campana, S. Soderberg, A. M. TI X-ray, UV, and optical observations of supernova 2006bp with Swift: Detection of early X-ray emission SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; supernovae : individual (SN 2006bp); ultraviolet : ISM; X-rays : general; X-rays : individual (SN 2006bp); X-rays : ISM ID SPACE-TELESCOPE ULTRAVIOLET; CIRCUMSTELLAR INTERACTION; RADIO-EMISSION; SN 1987A; MODEL ATMOSPHERES; SHOCK BREAKOUT; IA SUPERNOVAE; II SUPERNOVAE; SN-1987A; 1993J AB We present results on the X-ray and optical /UV emission from the Type II-P supernova (SN) 2006bp and the interaction of the SN shock with its environment, obtained with the X-Ray Telescope (XRT) and UV/Optical Telescope (UVOT) on board Swift. SN 2006bp is detected in X-rays at a 4.5 sigma level of significance in the merged XRT data from days 1 to 12 after the explosion. If the 0.2-10 keV band X-ray luminosity of L-0.(2-10) (1.8 +/- 0. 4); 1039 ergs s(-1) is caused by interaction of the SN shock with circumstellar material (CSM) deposited by a stellar wind from the progenitor's companion star, a mass-loss rate of. M approximate to (1x10(-5) M-circle dot yr(-1))(v(w)/10 km s(-1)) is inferred. The mass-loss rate is consistent with the nondetection in the radio with the VLA on days 2, 9, and 11 after the explosion and is characteristic of a red supergiant progenitor with a mass of approximate to 12-15 M-circle dot prior to the explosion. The Swift data further show a fading of the X-ray emission starting around day 12 after the explosion. In combination with a follow-up XMM-Newton observation obtained on day 21 after the explosion, an X-ray rate of decline of L-X proportional to t(n) with index n 1.2 +/- 0.6 is inferred. Since no other SN has been detected in X-rays prior to the optical peak, and since Type II-P SNe have an extended " plateau'' phase in the optical, we discuss the scenario that the X-rays might be due to inverse Compton scattering of photospheric optical photons off relativistic electrons produced in circumstellar shocks. However, due to the high required value of the Lorentz factor (10-100), which is inconsistent with the ejecta velocity inferred from optical line widths, we conclude that inverse Compton scattering is an unlikely explanation for the observed X-ray emission. C1 NASA, Goddard Space Flight Ctr, Astrophys Sci Div, XRay Astrophys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Steward Observ, Tucson, AZ 85721 USA. Osserv Astron Trieste, INAF, I-34131 Trieste, Italy. Max Planck Inst Astrophys, D-85741 Garching, Germany. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Astroparticle Phys Lab, Greenbelt, MD 20771 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22904 USA. Marquette Univ, Dept Phys, Milwaukee, WI 53201 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Tokyo, Sch Sci, Dept Astron, Tokyo 1130033, Japan. Max Planck Inst Extraterr Phys, D-85748 Garching, Germany. Osserv Astron Brera, INAF, I-23807 Merate, Italy. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. RP Immler, S (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, XRay Astrophys Lab, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012; Nomoto, Ken'ichi/A-4393-2011; Koss, Michael/B-1585-2015; OI Koss, Michael/0000-0002-7998-9581; Pian, Elena/0000-0001-8646-4858 NR 42 TC 30 Z9 30 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2007 VL 664 IS 1 BP 435 EP 442 DI 10.1086/518466 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189QA UT WOS:000248002400038 ER PT J AU Israel, GL Campana, S Dall'Osso, S Muno, MP Cummings, J Perna, R Stella, L AF Israel, G. L. Campana, S. Dall'Osso, S. Muno, M. P. Cummings, J. Perna, R. Stella, L. TI The post-burst awakening of the anomalous X-ray pulsar in Westerlund SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : individual (CXOU J164710.2-455216); stars : neutron; X-rays : bursts ID NEUTRON-STARS; XTE J1810-197; TRANSIENT MAGNETAR; HOT-SPOTS; EMISSION; BURSTS; SPECTRUM; OUTBURST; GLITCHES; CHANDRA AB On 2006 September 21, an intense (similar to 10(39) erg s(-1)) and short (20 ms) burst was detected by Swift BATat a position consistent with that of the candidate anomalous X-ray pulsar (AXP) CXOU J164710.2-455216, discovered by Chandra in 2005. Swift follow-up observations began similar to 13 hr after the event and found the source at a 1-10 keV flux level of about 4.5x10(-11) erg cm(-2) s(-1), i. e., similar to 300 times brighter than measured 5 days earlier by XMM-Newton. We report the results obtained from Swift BAT observations of the burst and subsequent Swift XRT observations carried out during the first 4 months after the burst. These data are complemented with those from two XMM-Newton observations (carried out just before and after the BAT event) and four archival Chandra observations carried out between 2005 and 2007. We find a phase-coherent solution for the source pulsations after the burst. The evolution of the pulse phase comprises an exponential component decaying with timescale of 1.4 days, which we interpret as the recovery stage following a large glitch (Delta v/v similar to 6x10(-5)). We also detect a quadratic component corresponding to a spin-down rate of. P similar to 9x10(-13) s s(-1), implying a magnetic field strength of 10(14) G. During the first Swift XRT observation taken 0.6 days after the burst, the spectrum showed a kT similar to 0: 65 keV blackbody (R-BB similar to 1.5 km) plus a Gamma similar to 2.3 power law accounting for about 60% of the 1-10 keV observed flux. Analysis of Chandra archival data, taken during 2005 when the source was in quiescence, reveal that the modulation in quiescence is 100% pulsed at energies above similar to 4 keV and consistent with the (unusually small-sized) blackbody component being occulted by the neutron star as it rotates. These findings demonstrate that CXOU J164710.2 -455216 is indeed an AXP; we compare them with the properties of three other AXPs which displayed similar behavior in the past. C1 Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. Osserv Astron Brera, INAF, I-23807 Merate, Italy. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. Univ Maryland Baltimore Cty, Goddard Space Flight Ctr, NASA, Greenbelt, MD 20771 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. RP Israel, GL (reprint author), Osserv Astron Roma, INAF, Via Frascati 33, I-00040 Monte Porzio Catone, Italy. EM gianluca@mporzio.astro.it; stella@mporzio.astro.it OI Israel, GianLuca/0000-0001-5480-6438 NR 42 TC 63 Z9 63 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2007 VL 664 IS 1 BP 448 EP 457 DI 10.1086/518224 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189QA UT WOS:000248002400040 ER PT J AU Podesta, JJ Roberts, DA Goldstein, ML AF Podesta, J. J. Roberts, D. A. Goldstein, M. L. TI Spectral exponents of kinetic and magnetic energy spectra in solar wind turbulence SO ASTROPHYSICAL JOURNAL LA English DT Article DE solar wind; turbulence ID MAGNETOHYDRODYNAMIC TURBULENCE; ALFVENIC TURBULENCE; SCALING PROPERTIES; MHD TURBULENCE; FLUCTUATIONS; SIMULATIONS; EVOLUTION AB Kinetic and magnetic energy spectra in the ecliptic plane near 1 AU are found to exhibit different power-law behaviors in the inertial range, with the magnetic spectrum often having a power-law exponent near 5/3 and the kinetic energy spectrum often having a power-law exponent near 3/2 ( the inertial range extends from approximately 5; 10-(4) 4 to 10(-1) Hz). The total energy, kinetic plus magnetic, has a power-law exponent that lies between 3/2 and 5/3, with a value near 1.6. The Alfve n ratio, the ratio of kinetic to magnetic energy, is found to be a slowly increasing function of frequency in the inertial range, increasing from roughly 0.5 to 0.9 in the frequency range from 10(-3) to 10(-1) Hz. These conclusions are based on the analysis of four distinct time intervals of solar wind magnetic field and plasma data obtained by the Wind spacecraft near the end of solar cycle 22 and at different times throughout solar cycle 23. Three 54 day intervals and one 81 day interval are used to compute power spectra in the range from 10(-5) to 1.7x10(-1) Hz. Power-law exponents are estimated from linear least-squares fits to the logarithm of the power spectral density versus the logarithm of the frequency over the frequency interval from 10(-3) to 10(-2) Hz. To prevent errors due to spectral aliasing, the last decade of the spectrum is omitted from the calculation of the power-law exponents. The results show that a measurable difference exists between the power-law exponents of velocity and magnetic field fluctuations and that this difference persists throughout the solar cycle. C1 NASA, Goddard Space Flight Ctr, Lab Geospace Phys, Heliosphys Sci Div, Greenbelt, MD 20771 USA. RP Podesta, JJ (reprint author), NASA, Goddard Space Flight Ctr, Lab Geospace Phys, Heliosphys Sci Div, Greenbelt, MD 20771 USA. EM jpodesta@solar.stanford.edu RI Roberts, Dana/D-4625-2012; Goldstein, Melvyn/B-1724-2008 NR 33 TC 123 Z9 123 U1 0 U2 12 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 20 PY 2007 VL 664 IS 1 BP 543 EP 548 DI 10.1086/519211 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189QA UT WOS:000248002400048 ER PT J AU Humayun, M Brandon, AD AF Humayun, Munir Brandon, Alan D. TI s-process implications from osmium isotope anomalies in chondrites SO ASTROPHYSICAL JOURNAL LA English DT Article DE nuclear reactions, nucleosynthesis, abundances; solar system : general ID GIANT BRANCH STARS; CROSS-SECTIONS; STATISTICAL-MODEL; NEUTRON-CAPTURE; NUCLEOSYNTHESIS; MOLYBDENUM; METEORITES; ZIRCONIUM; BARIUM; GRAINS AB Correlated isotopic anomalies in osmium (Os-186, Os-188, Os-190, measured with respect to Os-189) extracted from primitive carbonaceous chondrites tightly constrain the sigma(n) (Os-190)/sigma(n) (Os-188) ratio to be 0.859 +/- 0.042 ( +/- 5%) A recent measurement of the Maxwellian-averaged neutron-capture cross sections (MACSs) for Os-186,Os- 187,Os- 188 lowered the sigma(n)(Os-188) by 27% but did not measure sigma(n)(Os-190). From the sigma(n)(Os-190)/sigma(n)(Os-188) ratio, we infer sigma(n) (Os-190) = 249 +/- 18 mbarns for internal consistency with the new MACSs for the other Os isotopes. This approach is applicable to other isotopic anomalies in r- process/s-process ratios derived from meteorites for nuclei that do not have branching points between them. Branching at W-185 and Re-186 makes the Os-186/ Os-188 ratio a neutron dosimeter for the s-process that, with the new cross sections, yields an average neutron density, n(n) similar to 3 x 10(8) cm(-3). This low neutron density is consistent with previous results from Sr, Zr, Mo, and Ba isotopes that indicated a minor contribution from the Ne-22( alpha, n)Mg-25 neutron source relative to the C-13(alpha, n) O-16 neutron source. C1 Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Florida State Univ, Dept Geol Sci, Tallahassee, FL 32306 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Humayun, M (reprint author), Florida State Univ, Natl High Magnet Field Lab, 1800 E Paul Dirac Dr, Tallahassee, FL 32306 USA. EM humayun@magnet.fsu.edu; alan.d.brandon@nasa.gov RI Humayun, Munir/A-1247-2007; OI Humayun, Munir/0000-0001-8516-9435 NR 20 TC 8 Z9 8 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2007 VL 664 IS 1 BP L59 EP L62 DI 10.1086/520636 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189QD UT WOS:000248002700015 ER PT J AU Remijan, AJ Hollis, JM Lovas, FJ Cordiner, MA Millar, TJ Markwick-Kemper, AJ Jewell, PR AF Remijan, Anthony J. Hollis, J. M. Lovas, F. J. Cordiner, M. A. Millar, T. J. Markwick-Kemper, A. J. Jewell, P. R. TI Detection of C8H- and comparison with C8H toward IRC+10 216 SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : identification; radio lines : stars stars : AGB and post; AGB; stars : individual (IRC+10 216) ID ROTATIONAL SPECTRA; ION C6H; MILLIMETER; RADICALS; CLOUDS AB We report the detection of new transitions of octatetraynyl (C8H) toward the circumstellar envelope IRC + 10 216 using data taken with the 100 m Green Bank Telescope ( GBT). In addition, we report five features from the Ku, K, and Q bands that have been identified as transitions of the octatetraynyl anion ( C8H-). From a rotational temperature diagram and an assumed source size of 30", we find a total C8H column density of cm 8(3) x 10(12) cm(-2) and a rotational temperature of similar to 13 K. From the five detected transitions of C8H-, we find a total C8H- column density of similar to 21 x 10(12) cm(-2) consistent with a rotational temperature of similar to 34 K for a total (CH)-H-8/(CH-)-H-8 column density ratio of similar to 3.8. This observed C8H/C8H- column density ratio is similar to the theoretical prediction of 3.6, while the observed column densities were lower than that predicted by a factor of similar to 30. This prompted us to reinvestigate the initial conditions of the circumstellar envelope (CSE) model. The new model results are presented, and they more closely match the C8H and C8H- abundances observed with the GBT. Finally, we use the new CSE model results to predict the abundance of decapentaynyl (C10H), and we compare them with the measured upper limit found from the GBT observations. C1 Natl Radio Astron Observ, Charlottesville, VA 22903 USA. NASA, Goddard Space Flight Ctr, Computat & Informat Sci & Technol Off, Greenbelt, MD 20771 USA. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland. Univ Manchester, Sch Phys & Astron, Jodrell Bank, Ctr Astrophys, Manchester M60 1QD, Lancs, England. RP Remijan, AJ (reprint author), Natl Radio Astron Observ, Edgemont Rd 520, Charlottesville, VA 22903 USA. OI Millar, Tom/0000-0001-5178-3656 NR 17 TC 90 Z9 90 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 20 PY 2007 VL 664 IS 1 BP L47 EP L50 DI 10.1086/520704 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189QD UT WOS:000248002700012 ER PT J AU Shindell, D AF Shindell, Drew TI Local and remote contributions to Arctic warming SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GREENLAND ICE-SHEET; GODDARD-INSTITUTE; AIR-POLLUTION; BLACK CARBON; ART.; SIMULATIONS; TEMPERATURE; EMISSIVITY; SATELLITE; AEROSOLS AB [1] I investigate the relative impact of local and remote radiative forcing by tropospheric aerosols and ozone on Arctic climate using GISS climate model simulations. During boreal summer, Arctic climate is well-correlated with either the global or Arctic forcing. During other seasons, however, large-scale dynamics strongly influence the Arctic, so that the surface temperature response follows the global or Northern Hemisphere extratropical forcing much more closely. The decoupling is so strong that Arctic surface temperature trends often show the opposite sign to the local forcing. The analysis also demonstrates that ozone and aerosols affect Arctic climate more strongly per unit global forcing than well-mixed greenhouse gases, typically 2.5-5 times in non-summer seasons, making them powerful levers for influencing Arctic climate. However, controlling atmospheric burdens of climate-altering pollutants outside the polar region appears to be at least as important as controlling them within for mitigation of Arctic warming. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. RP Shindell, D (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM dshindell@giss.nasa.gov RI Shindell, Drew/D-4636-2012 NR 26 TC 37 Z9 38 U1 1 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 20 PY 2007 VL 34 IS 14 AR L14704 DI 10.1029/2007GL030221 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 193OZ UT WOS:000248285200001 ER PT J AU Rahman, R Wellard, CJ Bradbury, FR Prada, M Cole, JH Klimeck, G Hollenberg, LCL AF Rahman, Rajib Wellard, Cameron J. Bradbury, Forrest R. Prada, Marta Cole, Jared H. Klimeck, Gerhard Hollenberg, Lloyd C. L. TI High precision quantum control of single donor spins in silicon SO PHYSICAL REVIEW LETTERS LA English DT Article ID DOPED SILICON; STATES; DEVICE; SEMICONDUCTORS; RELAXATION; ATOM AB The Stark shift of the hyperfine coupling constant is investigated for a P donor in Si far below the ionization regime in the presence of interfaces using tight-binding and band minima basis approaches and compared to the recent precision measurements. In contrast with previous effective mass-based results, the quadratic Stark coefficient obtained from both theories agrees closely with the experiments. It is also shown that there is a significant linear Stark effect for an impurity near the interface, whereas, far from the interface, the quadratic Stark effect dominates. This work represents the most sensitive and precise comparison between theory and experiment for single donor spin control. Such precise control of single donor spin states is required particularly in quantum computing applications of single donor electronics, which forms the driving motivation of this work. C1 Purdue Univ, W Lafayette, IN 47907 USA. Univ Melbourne, Sch Phys, Ctr Quantum Comp Technol, Melbourne, Vic 3010, Australia. Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rahman, R (reprint author), Purdue Univ, W Lafayette, IN 47907 USA. EM rrahman@purdue.edu RI Cole, Jared/G-2992-2010; Hollenberg, Lloyd/B-2296-2010; Klimeck, Gerhard/A-1414-2012; OI Cole, Jared/0000-0002-8943-6518; Klimeck, Gerhard/0000-0001-7128-773X; Rahman, Rajib/0000-0003-1649-823X NR 29 TC 77 Z9 77 U1 0 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 20 PY 2007 VL 99 IS 3 AR 036403 DI 10.1103/PhysRevLett.99.036403 PG 4 WC Physics, Multidisciplinary SC Physics GA 192IN UT WOS:000248194700031 PM 17678301 ER PT J AU Stewart, JB Bifano, TG Cornelissen, S Bierden, P Levine, BM Cook, T AF Stewart, Jason B. Bifano, Thomas G. Cornelissen, Steven Bierden, Paul Levine, B. Martin Cook, Timothy TI Design and development of a 331-segment tip-tilt-piston mirror array for space-based adaptive optics SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article DE MEMS; deformable mirror; adaptive optics; amplitude correction; phase correction; coronagraph ID SINGLE APERTURE TELESCOPE; PLANET DETECTION; VISIBLE-LIGHT AB We report on the development of a micromachined silicon deformable mirror (DM) system for the hyper-contrast visible nulling coronagraph architecture designed by the Jet Propulsion Laboratory for NASN's Terrestrial Planet Finding (TPF) mission. The new DM is designed to achieve unprecedented optical quality and mechanical positioning precision as required by the nulling coronagraph. It consists of 331 close-packed hexagonal segments on a 600 mu m pitch. Each segment has three adjustable degrees of freedom controlling out-of-plane rotation (in two axes) and surface normal motion over a continuous range of +/- 3 mrad and 1 mu m, respectively. The coronagraph implementation specifies that each segment maintains an overall flatness better than 10 nm RMS, irrespective of segment angle. To achieve this objective, two design concepts were developed in parallel. The first design uses thick mirror segments consisting of epitaxial grown polysilicon (epipoly) to provide the mirror with high rigidity, allowing it to tilt without bending. The epipoly layer can also be highly polished to better than 1nm RMS local surface roughness. The second design uses thinner, more compliant mirror segments, but supports them with flexure-based electrostatic actuators that decouple tilt motion from mirror segment bending moments. The thinner mirror segment has reduced optical quality due to print-through effects, but offers greater ease in post-processing mirror curvature caused by residual stress gradients. DM segments fabricated with the flexure design experience a maximum mirror bend of 2.8 nut RMS at 4.3 mrad of tilt. Both DM designs and associated microfabrication processes are presented. Optical and electromechanical characterization results are also presented. (c) 2007 Elsevier B.V. All rights reserved. C1 Boston Univ, Dept Elect & Comp Engn, Boston, MA 02215 USA. Boston Univ, Dept Mfg Engn, Boston, MA 02215 USA. Boston Micromachines Corp, Watertown, MA USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Boston Univ, Dept Astron, Boston, MA 02215 USA. RP Stewart, JB (reprint author), 8 St Marys St, Boston, MA 02215 USA. EM jstew@bu.edu RI Bifano, Thomas/E-6412-2013 OI Bifano, Thomas/0000-0003-4952-2515 NR 11 TC 29 Z9 30 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 JUL 20 PY 2007 VL 138 IS 1 BP 230 EP 238 DI 10.1016/j.sna.2007.04.051 PG 9 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 193TF UT WOS:000248296900029 ER PT J AU Doser, DI Wiest, KR Sauber, J AF Doser, Diane I. Wiest, Katy R. Sauber, Jeanne TI Seismicity of the Bering Glacier region and its relation to tectonic and glacial processes SO TECTONOPHYSICS LA English DT Article DE bering glacier; southern Alaska; seismicity ID SOUTH-CENTRAL ALASKA; ST-ELIAS; YAKUTAT BLOCK; DEFORMATION; EARTHQUAKES; RATES; FLUCTUATIONS; SUBDUCTION; MOUNTAINS; EROSION AB We relocated over 1000 earthquakes of magnitude > 0.1 occurring between 1973 and 2001 in the Bering Glacier region of southern Alaska. We used first-motion data from these events to determine focal mechanisms and directly invert for stress orientations. Our results indicate that much of the seismicity in the region is occurring within the North American plate in a zone where an inferred structure, which lies beneath Bering Glacier, intersects the Chugach-St. Elias fault system. Stress-field analysis indicates that the events in the Bering Glacier surge reservoir region are likely occurring on northeast-trending thrust faults, consistent with previous modeling that suggested thrust faulting would be enhanced in regions of ice draw down. We also observe a stress field compatible with either high-angle normal or reverse faulting in regions located northwest of the Bering Glacier. This may indicate localized complexities in interactions between the Bering Glacier structure and the Chugach-St. Elias fault system. (c) 2007 Elsevier B.V. All rights reserved. C1 Univ Texas, Dept Geol Sci, El Paso, TX 79968 USA. NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab Code 698, Greenbelt, MD 20771 USA. RP Doser, DI (reprint author), Univ Texas, Dept Geol Sci, El Paso, TX 79968 USA. EM doser@geo.utep.edu RI Sauber, Jeanne/D-7684-2012 NR 23 TC 9 Z9 10 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD JUL 20 PY 2007 VL 439 IS 1-4 BP 119 EP 127 DI 10.1016/j.tecto.2007.04.005 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 196NV UT WOS:000248490200007 ER PT J AU Lin, B Xu, KM Minnis, P Wielicki, BA Hu, YX Chambers, L Fan, TF Sun, W AF Lin, Bing Xu, Kuan-Man Minnis, Patrick Wielicki, Bruce A. Hu, Yongxiang Chambers, Lin Fan, Tai-Fang Sun, Wenbo TI Coincident occurrences of tropical individual cirrus clouds and deep convective systems derived from TRMM observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEA-SURFACE TEMPERATURE; ENVIRONMENTAL-CONDITIONS; IRIS; SATELLITE; EVOLUTION; FEEDBACK AB [1] Satellite measurements of cloud properties and atmospheric radiation were used to investigate the effect of spatial and temporal scales on the coincident occurrences of tropical individual cirrus clouds ( ICCs) and deep convective systems ( DCSs). There is little or even negative correlation between instantaneous occurrences of ICC and DCS in small areas. When spatial and temporal domains are increased, ICCs become more dependent on DCSs due to the origination of many ICCs from DCSs and moisture supply from the DCS in the upper troposphere for the ICCs to grow, resulting in significant positive correlation between the two types of clouds. The estimated radiative feedback due to the change in tropical high cloud area coverage with sea surface temperature appears small and about - 0.14 Wm(-2) K-1, which would not cancel out the estimated anthropogenic forcing of doubled atmospheric CO2. C1 NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. SSAI, Hampton, VA 23666 USA. Hampton Univ, Dept Atmospher & Planetary Sci, Hampton, VA 23666 USA. RP Lin, B (reprint author), NASA, Langley Res Ctr, Sci Directorate, MS 420, Hampton, VA 23681 USA. EM bing.lin@nasa.gov RI Xu, Kuan-Man/B-7557-2013; Minnis, Patrick/G-1902-2010; Hu, Yongxiang/K-4426-2012 OI Xu, Kuan-Man/0000-0001-7851-2629; Minnis, Patrick/0000-0002-4733-6148; NR 18 TC 7 Z9 7 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 JUL 19 PY 2007 VL 34 IS 14 AR L14804 DI 10.1029/2007GL029768 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 193OX UT WOS:000248285000002 ER PT J AU Farrell, WM Stubbs, TJ Vondrak, RR Delory, GT Halekas, JS AF Farrell, W. M. Stubbs, T. J. Vondrak, R. R. Delory, G. T. Halekas, J. S. TI Complex electric fields near the lunar terminator: The near-surface wake and accelerated dust SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PLASMA WAKE AB The lunar near- surface electric field in the vicinity of the terminator is very complex, with a surface polarity change from dayside- positive to nightside- negative potentials and the formation of intensely negative potentials due to the low plasma density and increased temperatures in the trailing lunar wake region. Presented is a preliminary map of the terminator near- surface E- field magnitude and a discussion of dust dynamics in this E- field structure, with intense vertical fields tending to give rise to vertically directed dust trajectories ( aligned with the surface normal). Application of this process of wake- generated surface E- fields and dust to the more complicated topography at the lunar landing site of Apollo 17 is then used to explain the detection of fast moving ( similar to 500 m/ sec) but nightside- directed dust in the region. We suggest that local solar wind orographic effects occurring at lunar sunrise/ sunset can create a plasma void on the anti- sunward side of obstructing features and associated wake- generated surface E- fields can then be the source of the nightside-directed grains. C1 NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Heliophys Div, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Farrell, WM (reprint author), NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Code 690, Greenbelt, MD 20771 USA. EM william.farrell@gsfc.nasa.gov RI Stubbs, Timothy/I-5139-2013; Farrell, William/I-4865-2013; OI Stubbs, Timothy/0000-0002-5524-645X; Halekas, Jasper/0000-0001-5258-6128 NR 12 TC 41 Z9 41 U1 1 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 JUL 18 PY 2007 VL 34 IS 14 AR L14201 DI 10.1029/2007GL029312 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 193OW UT WOS:000248284900002 ER PT J AU Strassberg, G Scanlon, BR Rodell, M AF Strassberg, Gil Scanlon, Bridget R. Rodell, Matthew TI Comparison of seasonal terrestrial water storage variations from GRACE with groundwater-level measurements from the High Plains Aquifer (USA) SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RESOURCES; SYSTEM AB This study presents the first comparison of seasonal groundwater storage (GWS) variations derived from GRACE satellite data with groundwater- level measurements in the High Plains Aquifer, USA (450,000 km 2). Correlation between seasonal GRACE terrestrial water storage ( TWS) and the sum of GWS estimated from field measurements (2,700 wells) and soil moisture (SM) simulated by a land surface model is high (R = 0.82). Correlation between GRACE- derived and measured GWS is also significant (R = 0.58). Seasonal GRACE- derived TWS and GWS changes were detectable ( >= uncertainty) in 7 and 5 out of 9 monitored periods respectively whereas maximum changes (between winter/ spring and summer/ fall) in TWS and GWS were detectable in all 5 monitored periods. These results show the potential for GRACE to monitor GWS changes in semiarid regions where irrigation pumpage causes large seasonal GWS variations. C1 Univ Texas, Jackson Sch Geosci, Bur Econ Geol, Austin, TX 78758 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Strassberg, G (reprint author), Univ Texas, Jackson Sch Geosci, Bur Econ Geol, Austin, TX 78758 USA. RI Rodell, Matthew/E-4946-2012; Scanlon, Bridget/A-3105-2009 OI Rodell, Matthew/0000-0003-0106-7437; Scanlon, Bridget/0000-0002-1234-4199 NR 25 TC 51 Z9 57 U1 0 U2 19 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 JUL 18 PY 2007 VL 34 IS 14 AR L14402 DI 10.1029/2007GL030139 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 193OW UT WOS:000248284900004 ER PT J AU Pelkey, SM Mustard, JF Murchie, S Clancy, RT Wolff, M Smith, M Milliken, R Bibring, JP Gendrin, A Poulet, F Langevin, Y Gondet, B AF Pelkey, S. M. Mustard, J. F. Murchie, S. Clancy, R. T. Wolff, M. Smith, M. Milliken, R. Bibring, J.-P. Gendrin, A. Poulet, F. Langevin, Y. Gondet, B. TI CRISM multispectral summary products: Parameterizing mineral diversity on Mars from reflectance SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID THERMAL EMISSION SPECTROMETER; OMEGA/MARS EXPRESS; WATER-VAPOR; POLAR-CAP; MGS-TES; OLIVINE; REGION; ICE; SPECTROSCOPY; SPECTRA AB [1] The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter (MRO) is the most recent spectrometer to arrive at Mars. The instrument is a hyperspectral imager covering visible to near-infrared wavelengths (0.37-3.92 mu m at 6.55 nm/channel). Summary products based on multispectral parameters will be derived from reflectances in key wavelengths for every CRISM observation. There are 44 summary products formulated to capture spectral features related to both surface mineralogy and atmospheric gases and aerosols. The intent is to use the CRISM summary products as an analysis tool to characterize composition as well as a targeting tool to identify areas of mineralogic interest to observe at higher spectral and spatial resolution. This paper presents the basis for the summary products and examines the validity of the above approach using data from the Mars Express OMEGA instrument, a visible/near-infrared imaging spectrometer with spatial and spectral coverage similar to that of CRISM. Our study shows that the summary products vary in utility, but succeed in capturing the known diversity of the Martian surface and variability of the Martian atmosphere, and successfully highlight locations with strong spectral signatures. Thus the CRISM summary products will be useful in both operations and science applications. Caveats and limitations related to the summary products and their interpretation are presented to assist with their application by the community at large. C1 Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Space Sci Inst, Boulder, CO 80301 USA. Inst Astrophys Spatiale, F-91405 Orsay, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pelkey, SM (reprint author), Brown Univ, Dept Geol Sci, Box 1846, Providence, RI 02912 USA. RI Smith, Michael/C-8875-2012; Murchie, Scott/E-8030-2015 OI Murchie, Scott/0000-0002-1616-8751 NR 47 TC 183 Z9 183 U1 3 U2 23 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 JUL 18 PY 2007 VL 112 IS E8 AR E08S14 DI 10.1029/2006JE002831 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 193PZ UT WOS:000248287800001 ER PT J AU Altobelli, N Dikarev, V Kempf, S Srama, R Helfert, S Moragas-Klostermeyer, G Roy, M Grun, E AF Altobelli, N. Dikarev, V. Kempf, S. Srama, R. Helfert, S. Moragas-Klostermeyer, G. Roy, M. Gruen, E. TI Cassini/Cosmic Dust Analyzer in situ dust measurements between Jupiter and Saturn SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERSTELLAR DUST; ZODIACAL LIGHT; SOLAR-SYSTEM; ULYSSES SPACECRAFT; RADIATION PRESSURE; STREAM PARTICLES; E-RING; GALILEO; DETECTOR; FLUX AB We report an analysis of the Cosmic Dust Analyzer data obtained during the interplanetary cruise of the Cassini spacecraft between Jupiter and Saturn. The data cover the time period between the Jupiter flyby and the Saturn orbit insertion. Seventeen dust particles on bound and unbound ( hyperbolic) orbits were also detected, with sizes in the submicrometer to the micrometer range. Our measurements are compared with the Pioneer dust data obtained 30 years ago and model predictions. Particles on bound orbits have low eccentricities and low inclinations. Possible sources are short-period Jupiter family comets and circumsolar dust. The impactors on hyperbolic orbits were identified as being most likely interstellar dust (ISD) grains with a radius of approximate to 0.4 mu m. The corresponding flux of approximate to 2 x 10(-5) m(-2) s(-1) is in a very good agreement with the ISD flux measurements performed by the Ulysses spacecraft over the same time period. C1 NASA, JPL, Pasadena, CA 91109 USA. Univ Jena, Inst Astrophys, D-6900 Jena, Germany. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. St Petersburg State Univ, Astron Inst, St Petersburg, Russia. Univ Hawaii, Hawaii Inst Geophys & Plantol, Honolulu, HI 96822 USA. RP Altobelli, N (reprint author), NASA, JPL, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM nicolas.altobelli@jpl.nasa.gov OI KEMPF, SASCHA/0000-0001-5236-3004 NR 48 TC 8 Z9 8 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 JUL 18 PY 2007 VL 112 IS A7 AR A07105 DI 10.1029/2006JA011978 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 193QL UT WOS:000248289000001 ER PT J AU Ryu, D Jackson, TJ Bindlish, R Le Vine, DM AF Ryu, Dongryeol Jackson, Thomas J. Bindlish, Rajat Le Vine, David M. TI L-band microwave observations over land surface using a two-dimensional synthetic aperture radiometer SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOIL-MOISTURE RETRIEVAL; AMSR-E AB Antenna size is a major factor that has limited realization of the potential capabilities of L-band (1.4 GHz) microwave radiometry to estimate surface soil moisture from space. However, emerging interferometric technology, called aperture synthesis, has been developed to address this limitation. The Soil Moisture and Ocean Salinity (SMOS) mission will apply the technique to monitor these parameters at a global- scale in the near future. The first airborne experiment using an aircraft prototype called the Two-Dimensional Synthetic Aperture Radiometer (2D- STAR) was performed during Soil Moisture Experiment in 2003 (SMEX03). To gain insight, the L- band brightness temperature data acquired by 2D-STAR in Alabama was compared with C-band data collected simultaneously by another aircraft instrument called the Polarimetric Scanning Radiometer ( PSR), and also compared with surface soil moisture measurements from in- situ observations sites. Results show that there was fairly good radiometric sensitivity of the synthetic aperture radiometer to the soil moisture both in pasture and also in forest areas. The overall performance of the L-band synthetic aperture radiometer in the presence of vegetation appears to be better than the C-band real aperture radiometer. C1 USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20250 USA. NASA Goddard Space Flight Ctr, Instrument Sci Branch, Greenbelt, MD USA. RP Ryu, D (reprint author), USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20250 USA. EM tom.jackson@ars.usda.gov RI Ryu, Dongryeol/C-5903-2008 OI Ryu, Dongryeol/0000-0002-5335-6209 NR 14 TC 11 Z9 11 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 17 PY 2007 VL 34 IS 14 AR L14401 DI 10.1029/2007GL030098 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 193OV UT WOS:000248284800005 ER PT J AU Gjerloev, JW Hoffman, RA Sigwarth, JB Frank, LA AF Gjerloev, J. W. Hoffman, R. A. Sigwarth, J. B. Frank, L. A. TI Statistical description of the bulge-type auroral substorm in the far ultraviolet SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC SUBSTORMS; EXPANSIVE PHASE; TIME CONSTANTS; IMAGER; ONSET; DYNAMICS; FEATURES; BEHAVIOR; MOTIONS; SURGES AB [1] Using global auroral images at ultraviolet wavelengths during 116 substorms, we have obtained quantitative measures of key features of the bulge aurora and oval aurora: their temporal variations, their locations, rates, and characteristics of gross expansion and decay, and the variability of these parameters. The expansion period identified solely from images varied primarily from 10 to 40 minutes, with an average of 30.9 minutes. To avoid mixing expansion data with recovery data, we normalized the time of each substorm to one unit from onset to maximum expansion. The average onset location was 22.6 magnetic local time ( MLT) and 66.8 degrees invariant latitude ( ILat), in good agreement with previous analyses. We found that the bulge aurora rapidly expanded out of the onset location approximately equally to the west ( surge) and to the east, so that the average center of the bulge remained close to the onset MLT. This is also the case for average location of the maximum expansion in latitude of the bulge. Thus the bulge is offset about 1 1/2 hours west of midnight. By half the expansion period the bulge has usually expanded poleward sufficiently to reveal a brightened portion of the original auroral oval. This brightening expands less than 1 hour MLT to the west, but rapidly to the east, farther than the east end of the bulge. Thus the two auroras are offset in MLT. The bulge expansion is fastest initially but slows for the second half of the expansion period. The ends of the bulge continue a small expansion poleward during early recovery when the center of the bulge slowly retreats. The large spreads of substorm expansion times, the onset locations and in the locations in Delta MLT and Delta ILat of the key features of these auroras, argue strongly for the need to normalize the time of expansion and location of key features of the substorm for any kind of superposed epoch analysis to be meaningful. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 21218 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD USA. Univ Massachusetts Lowell, Dept Phys & Astron, Lowell, MA 01854 USA. RP Gjerloev, JW (reprint author), Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 21218 USA. EM jesper.gjerloev@jhuapl.edu NR 34 TC 21 Z9 21 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 JUL 17 PY 2007 VL 112 IS A7 AR A07213 DI 10.1029/2006JA012189 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 193QK UT WOS:000248288900002 ER PT J AU Hu, JL Brooks, KP Holladay, JD Howe, DT Simon, TM AF Hu, Jianli Brooks, Kriston P. Holladay, Jamelyn D. Howe, Daniel T. Simon, Thomas M. TI Catalyst development for microchannel reactors for martian in situ propellant production SO CATALYSIS TODAY LA English DT Article; Proceedings Paper CT Topical Conference on Applications of Micro-Reactor Engineering held at the AIChE Spring Conference CY APR 23-27, 2006 CL Orlando, FL SP Amer Inst Chem Engineers DE microchannel reactor; RWGS; Sabatier reaction; structured catalyst; ISRU; Mars exploration ID CARBON-DIOXIDE; HYDROGENATION AB Catalytic microchannel reactors were designed for in situ propellant production for Mars exploration. In the reactor system, the Sabatier and the reverse water-gas-shift (RWGS) reactions were carried out for methane and oxygen production using carbon dioxide and hydrogen as feed stock. The focus of the present study was on developing catalysts for these two reactions, aiming at intensifying reactor operation. Demonstrated in this study were the catalyst development pathways and integration methodologies for microchannel reactor system. Initially, near intrinsic kinetic performance was obtained with powder form catalyst. Catalytic performance of the powder form material was therefore used to guide development of structured catalysts which were fabricated on FeCrAlY substrates. In this study, the effects of the noble metals and the properties of their supports on the conversion of CO2 were evaluated. It was found that 3% Ru/TiO2 (R/A = 60:40) and 6%Ru/CeO2-ZrO2 were very active Sabatier and RWGS catalysts allowing to achieve near equilibrium conversion at high throughputs. In the stability testing under repeated start-up and shutdown cycles, both the Sabatier and the RWGS catalysts Were stable, retaining initial activities for sustained period of time. (c) 2007 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Hu, JL (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd, Richland, WA 99352 USA. EM jianli.hu@pnl.gov NR 10 TC 11 Z9 11 U1 1 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD JUL 15 PY 2007 VL 125 IS 1-2 BP 103 EP 110 DI 10.1016/j.cattod.2007.01.067 PG 8 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 195JR UT WOS:000248409000016 ER PT J AU Ray, RD AF Ray, Richard D. TI Decadal climate variability: Is there a tidal connection? SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE AIR-TEMPERATURE; PEAK ASTRONOMICAL TIDES; NORTH PACIFIC; NUMERICAL-MODEL; OCEAN TIDES; SEA; CYCLE; DISSIPATION; ENERGY AB A possible connection between oceanic tides and climate variability arises from modulations in tidally induced vertical mixing. The idea is reexamined here with emphasis on near-decadal time scales. Occasional extreme tides caused by unusually favorable alignments of the moon and sun are unlikely to influence decadal climate, since these tides are of short duration and, in fact, are barely larger than the typical spring tide near lunar perigee. The argument by Keeling and Whorf in favor of extreme tides is further handicapped by an insufficiently precise catalog of extreme tides. A more plausible connection between tides and near-decadal climate is through "harmonic beating" of nearby tidal spectral lines. The 18.6-yr modulation of diurnal tides is the most likely to be detectable. Possible evidence for this is reviewed. Some of the most promising candidates rely on temperature data in the vicinity of the North Pacific Ocean where diurnal tides are large, but definitive detection is hindered by the shortness of the time series. Paleoclimate temperature data deduced from tree rings are suggestive, but one of the best examples shows a phase reversal, which is evidence against a tidal connection. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ray, RD (reprint author), NASA, Goddard Space Flight Ctr, Code 698, Greenbelt, MD 20771 USA. EM richard.ray@nasa.gov RI Ray, Richard/D-1034-2012 NR 57 TC 25 Z9 26 U1 0 U2 17 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 15 PY 2007 VL 20 IS 14 BP 3542 EP 3560 DI 10.1175/JCLI4193.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 196LZ UT WOS:000248484700013 ER PT J AU Chen, YH Del Genio, AD Chen, JY AF Chen, Yonghua Del Genio, Anthony D. Chen, Junye TI Tropical atmospheric El Nino signal in satellite precipitation data and a global climate model SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; LATENT HEATING DISTRIBUTIONS; SOUTHERN-OSCILLATION; AIR-TEMPERATURE; CUMULUS PARAMETERIZATION; STRATIFORM PRECIPITATION; PROFILING ALGORITHM; VERTICAL PROFILES; INDIAN-OCEAN; TRMM AB Aspects of the tropical atmospheric response to El Nino related to the global energy and water cycle are examined using satellite retrievals from the Tropical Rainfall Measuring Mission and the Advanced Microwave Scanning Radiometer-E and simulations from the Goddard Institute for Space Studies (GISS) general circulation model (GCM). The El Nino signal is extracted from climate fields using a linear cross-correlation technique that captures local and remote in-phase and tagged responses. Passive microwave and radar precipitation anomalies for the 1997/98 and 2002/03 El Ninos and the intervening La Nina are highly correlated, but anomalies in stratiform-convective rainfall partitioning in the two datasets are not. The GISS GCM produces too much rainfall in general over ocean and too little over land. Its atmospheric response to El Nino is weaker and decays a season too early. Underestimated stratiform rainfall fraction (SRF) and convective downdraft mass flux in the GISS GCM and excessive shallow convective and low stratiform cloud result in latent heating that peaks at lower altitudes than inferred from the data. The GISS GCM also underestimates the column water vapor content throughout the Tropics, which causes it to overestimate outgoing longwave radiation. The response of both quantities to interannual Hadley circulation anomalies is too weak. The GISS GCM's Walker circulation also exhibits a weak remote response to El Nino, especially over the Maritime Continent and western Indian Ocean. This appears to be a consequence of weak static stability due to the model's lack of upper-level stratiform anvil heating, excessive low-level heating, and excessive dissipation due to cumulus momentum mixing. Our results suggest that parameterizations of mesoscale updrafts, convective downdrafts, and cumulus-scale pressure gradient effects on momentum transport are keys to a reasonable GISS GCM simulation of tropical interannual variability. C1 NASA, Goddard Inst Space Studies, Global Modeling & Assimilat Off, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. RP Del Genio, AD (reprint author), NASA, Goddard Inst Space Studies, Global Modeling & Assimilat Off, 2880 Broadway, New York, NY 10025 USA. EM adelgenio@giss.nasa.gov RI Chen, Junye/G-4301-2011; Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 61 TC 13 Z9 14 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PD JUL 15 PY 2007 VL 20 IS 14 BP 3580 EP 3601 DI 10.1175/JCLI4208.1 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 196LZ UT WOS:000248484700015 ER PT J AU Chiang, YM Hsu, KL Chang, FJ Hong, Y Sorooshian, S AF Chiang, Yen-Ming Hsu, Kuo-Lin Chang, Fi-John Hong, Yang Sorooshian, Soroosh TI Merging multiple precipitation sources for flash flood forecasting SO JOURNAL OF HYDROLOGY LA English DT Article DE recurrent neural; networks; satellite-derived; precipitation; merged precipitation; bias adjustment; flood forecasting ID ARTIFICIAL NEURAL-NETWORK; PREDICTION; RECURRENT; MODEL AB We investigated the effectiveness of combining gauge observations and satellite-derived precipitation on flood forecasting. Two data merging processes were proposed: the first one assumes that the individual precipitation measurement is non-bias, while the second process assumes that each precipitation source is biased and both weighting factor and bias parameters are to be calculated. Best weighting factors as well as the bias parameters were calculated by minimizing the error of hourly runoff prediction over Wu-Tu watershed in Taiwan. To simulate the hydrologic response from various sources of rainfall sequences, in our experiment, a recurrent neural network (RNN) model was used. The results demonstrate that the merged method used in this study can efficiently combine the information from both rainfall sources to improve the accuracy of flood forecasting during typhoon periods. The contribution of satellite-based rainfall, being represented by the weighting factor, to the merging product, however, is highly related to the effectiveness of ground-based rainfall observation provided gauged. As the number of gauge observations in the basin is increased, the effectiveness of satellite-based observation to the merged rainfall is reduced. This is because the gauge measurements provide sufficient information for flood forecasting; as a result the improvements added on satellite-based rainfall are limited. This study provides a potential advantage for extending satellite-derived precipitation to those watersheds where gauge observations are limited. (C) 2007 Elsevier B.V. All rights reserved. C1 Natl Taiwan Univ, Dept Bioenvironm Syst Engn, Taipei 10764, Taiwan. Univ Calif Irvine, Ctr Hydrometeorol & Remote Sensing, Dept Civil & Environm Engn, Irvine, CA 92717 USA. NASA, Goddard Space Flight Ctr, GEST, UMBC, Greenbelt, MD 20771 USA. RP Chang, FJ (reprint author), Natl Taiwan Univ, Dept Bioenvironm Syst Engn, Taipei 10764, Taiwan. EM changfj@ntu.edu.tw RI Hong, Yang/D-5132-2009; sorooshian, soroosh/B-3753-2008 OI Hong, Yang/0000-0001-8720-242X; sorooshian, soroosh/0000-0001-7774-5113 NR 29 TC 33 Z9 34 U1 1 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD JUL 15 PY 2007 VL 340 IS 3-4 BP 183 EP 196 DI 10.1016/j.jhydrol.2007.04.007 PG 14 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 191XY UT WOS:000248166500004 ER PT J AU Singh, M Asthana, R AF Singh, M. Asthana, R. TI Joining of zirconium diboride-based ultra high-temperature ceramic composites using metallic glass interlayers SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE brazing; CMC's; microstructure; interface SEM; EDS; microhardness AB Three zirconium diboride (ZrB2)-based ultra-high-temperature cerarnic-matrix composites: ZrB2-SCS9-SiC (ZSS), ZrB2-SiC-C (ZSC), and ZrB2-SiC (ZS), were joined to themselves and to commercially pure Ti using two boron-containing amorphous Ni-base braze alloys (MBF-20 and MBF-30). The SEM and EDS examinations of the joint microstructure and interface composition revealed intimate composite-to-braze contact and metallurgically sound joint interfaces. The dissolution of Ti and ZrB2 in molten braze, and redistribution of Zr, Si, Ti and Cr across the joint region was observed. Fine hairline cracks formed in some of the joints due to thermal stresses from joining. The Knoop microhardness measurements revealed a peak hardness of 1600 KHN within the braze region in the ZSS and ZSC composites, and lower (< 1000 KHN) hardness within the composites. The incomplete densification of ZSS during composite fabrication, and addition of carbon (and the resulting weakening of interfaces) in ZSC led to low hardness values within these composites in spite of the presence of hard ZrB2 and SiC phases. In contrast, the fully dense, hot-pressed ZrB2-SiC (ZS) composites exhibited high hardness (about 2100 KHN). (C) 2007 Elsevier B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. Univ Wisconsin, Dept Engn & Technol, Menomonie, WI 54751 USA. RP Singh, M (reprint author), NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. EM msingh@grc.nasa.gov NR 24 TC 56 Z9 60 U1 0 U2 22 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 15 PY 2007 VL 460 BP 153 EP 162 DI 10.1016/j.msea.2007.01.015 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 171HJ UT WOS:000246726200023 ER PT J AU Choi, SR Bansal, NP Garg, A AF Choi, Sung R. Bansal, Narottam P. Garg, Anita TI Mechanical and microstructural characterization of boron nitride nanotubes-reinforced SOFC seal glass composite SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE nanocomposite; electron microscopy; mechanical properties; glass ceramics; fuel cells ID FRACTURE-TOUGHNESS; CARBON NANOTUBES; STRENGTH AB Barium calcium aluminosilicate G18 glass composite reinforced with 4 wt% of boron nitride nanotubes (BNNT) were fabricated via hot pressing. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to characterize the microstructural features of the G18 glass-BNNT composite. Flexure strength, fracture toughness, elastic modulus, and microhardness of the composite were determined at ambient temperature. The strength of the G18 glass-BNNT composite was greater by as much as 90% and fracture toughness by as much as 35% than those of the unreinforced G18 glass. Microscopic examination of the composite fracture surfaces revealed pullout of the BNNTs. Density, elastic modulus, and Vickers microhardness of the composite were a little lower than those of the unreinforced glass. Published by Elsevier B.V. C1 Naval Air Syst Command, Patuxent River, MD 20670 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Choi, SR (reprint author), Naval Air Syst Command, Patuxent River, MD 20670 USA. EM sung.choi1@navy.mil NR 23 TC 39 Z9 42 U1 4 U2 16 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 15 PY 2007 VL 460 BP 509 EP 515 DI 10.1016/j.msea.2007.01.084 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 171HJ UT WOS:000246726200070 ER PT J AU Catling, DC Claire, MW Zahnle, KJ AF Catling, D. C. Claire, M. W. Zahnle, K. J. TI Anaerobic methanotrophy and the rise of atmospheric oxygen SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT Discussion Meeting on Trace Gas Biogeochemistry and Global Change CY NOV 13-14, 2006 CL Royal Soc, London, ENGLAND HO Royal Soc DE oxygen; methane; methanotrophy; Archaean; Proterozoic; atmospheric evolution ID METHANE OXIDATION RATES; ARCHEAN SULFUR CYCLE; SULFATE REDUCTION; MARINE-SEDIMENTS; EARLY EARTH; GREAT OXIDATION; HAMERSLEY BASIN; SEA SEDIMENTS; EARLY HISTORY; GAS HYDRATE AB In modern marine sediments, the anoxic decomposition of organic matter generates a significant flux of methane that is oxidized microbially with sulphate under the seafloor and never reaches the atmosphere. In contrast, prior to ca 2.4 Gyr ago, the ocean had little sulphate to support anaerobic oxidation of methane (AOM) and the ocean should have been an important methane source. As atmospheric 02 and seawater sulphate levels rose on the early Earth, AOM would have increasingly throttled the release of methane. We use a biogeochemical model to simulate the response of early atmospheric 02 and CH(4) to changes in marine AOM as sulphate levels increased. Semi-empirical relationships are used to parameterize global AOM rates and the evolution of sulphate levels. Despite broad uncertainties in these relationships, atmospheric 02 concentrations generally rise more rapidly and to higher levels (of order approx. 10(-3) bar versus approx. 10(-4) bar) as a result of including AOM in the model. Methane levels collapse prior to any significant rise in 02, but counter-intuitively, methane re-rises after 02 rises to higher levels when AOM is included. As 02 concentrations increase, shielding of the troposphere by stratospheric ozone slows the effective reaction rate between oxygen and methane. This effect dominates over the decrease in the methane source associated with AOM. Thus, even with the inclusion of AOM, the simulated Late Palaeoproterozoic atmosphere has a climatologically significant level of methane of approximately 50 ppmv. C1 Univ Bristol, Dept Earth Sci, Bristol BS8 1RJ, Avon, England. Univ Washington, Dept Atmospher Sci, Astrobiol Program, Seattle, WA 98195 USA. Univ Washington, Dept Astron, Astrobiol Program, Seattle, WA 98195 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Catling, DC (reprint author), Univ Bristol, Dept Earth Sci, Wills Mem Bldg,Queens Rd, Bristol BS8 1RJ, Avon, England. EM david.catling@bristol.ac.uk RI Catling, David/D-2082-2009; OI Catling, David/0000-0001-5646-120X NR 65 TC 24 Z9 29 U1 4 U2 21 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD JUL 15 PY 2007 VL 365 IS 1856 BP 1867 EP 1888 DI 10.1098/rsta.2007.2047 PG 22 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 186LS UT WOS:000247780800014 PM 17513257 ER PT J AU Hansen, J Sato, M Kharecha, P Russell, G Lea, DW Siddall, M AF Hansen, James Sato, Makix Kharecha, Pushker Russell, Gary Lea, David W. Siddall, Mark TI Climate change and trace gases SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT Discussion Meeting on Trace Gas Biogeochemistry and Global Change CY NOV 13-14, 2006 CL Royal Soc, London, ENGLAND HO Royal Soc DE climate change; trace gases; climate feedbacks; black carbon; sea level; Arctic ID CARBON-CYCLE FEEDBACKS; SEA-LEVEL RISE; PENULTIMATE DEGLACIATION; TEMPERATURE-CHANGES; ATMOSPHERIC CO2; SNOWBALL EARTH; GLACIAL CYCLES; GLOBAL CHANGE; ICE CORE; GREENHOUSE AB Palaeoclimate data show that the Earth's climate is remarkably sensitive to global forcings. Positive feedbacks predominate. This allows the entire planet to be whipsawed between climate states. One feedback, the 'albedo flip' property of ice/water, provides a powerful trigger mechanism. A climate forcing that 'flips' the albedo of a sufficient portion of an ice sheet can spark a cataclysm. Inertia of ice sheet and ocean provides only moderate delay to ice sheet disintegration and a burst of added global warming. Recent greenhouse gas (GHG) emissions place the Earth perilously close to dramatic climate chan-e that could run out of our control. with great dangers for humans and other creatures. Carbon dioxide (CO2) is the largest human-made climate forcing, but other trace constituents are also important. Only intense simultaneous efforts to Slow CO2 emissions and reduce non-Co-2 forcings can keep climate within or near the range of the past million years. The most important of the non-CO2 forcings is methane (CH4), as it causes the second largest human-made GHG climate forcing and is the principal cause of increased tropospheric ozone (03), which is the third largest GHG forcing. Nitrous oxide (N2O) should also be a focus of climate mitigation efforts. Black carbon ('black soot') has a high global warming potential (approx. 2000, 500 and 200 for 20, 100 and 500, years, respectively) and deserves greater attention. Some forcings are especially effective at high latitudes, so concerted efforts to reduce their emissions could preserve Arctic ice, while also having major benefits for human health, agricultural productivity and the global environment. C1 Columbia Univ, NASA, Goddard Inst Space Studies, Ear Inst, New York, NY 10025 USA. Univ Calif Santa Barbara, Dept Earth Sci, Santa Barbara, CA 93106 USA. Columbia Univ, Lamont Doherty Geol Observ, Palisades, NY 10964 USA. RP Hansen, J (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, Ear Inst, 2880 Broadway, New York, NY 10025 USA. EM jhansen@giss.nasa.gov NR 79 TC 198 Z9 211 U1 11 U2 76 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X EI 1471-2962 J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD JUL 15 PY 2007 VL 365 IS 1856 BP 1925 EP 1954 DI 10.1098/rsta.2007.2052 PG 30 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 186LS UT WOS:000247780800018 PM 17513270 ER PT J AU Hartle, RE Sittler, EC AF Hartle, R. E. Sittler, E. C., Jr. TI Pickup ion phase space distributions: Effects of atmospheric spatial gradients SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PRESSURE-BALANCED STRUCTURES; SOLAR-WIND; CYCLOTRON WAVES; VOYAGER-2 OBSERVATIONS; PLASMA OBSERVATIONS; INTERSTELLAR IONS; OUTER HELIOSPHERE; COSMIC-RAYS; UP IONS; PROTONS AB [1] Spatial variations of the neutral source gases of pickup ions are known to affect the velocity distributions of the ions. An expression for the phase space density of pickup ions is derived from the Vlasov equation with a delta function ion source in velocity space that explicitly accounts for the spatial variation of the neutral gas. The background plasma velocity is uniform and perpendicular to a constant ambient magnetic field, which together produce a uniform motional electric field. The neutral source density is one dimensional, varying exponentially along the flow axis with a fixed scale height. The solutions apply to the limiting case of a weak interaction with negligible mass loading. The resulting ring distribution is applied to two examples approximating these criteria; i.e., pickup ions formed in the solar wind interaction with the Earth's Moon and the interaction of Saturn's rotating magnetosphere with Titan. A fundamental parameter appears in the resulting phase space density expression; namely, alpha = r(g)/H, the ratio of the gyroradius to the scale height. When alpha << 1, the interaction is fluid-like with all orbit phases of pickup ion cycloidal motion present at an observation point. If alpha << 1, the pickup ions appear as ion beams, where the phase space distribution peaks over a small velocity range at an observation site in the source region and the ions will have only executed the beginning phases of their cycloidal motion. The principal contribution to the ions in the velocity peak derives from ions born over a neutral scale height upstream from the observation site. The pickup ion phase space density expression, constrained by spacecraft plasma ion spectrometer and magnetometer measurements, can be used to estimate the neutral source densities of a planetary body's exosphere and its composition. Potential applications are the lunar surface composition, Venus' atmospheric interaction with the solar wind, the interaction of the Galilean moons with Jupiter's magnetosphere, Saturn's icy moons interacting with its magnetosphere, and Titan's interaction with Saturn's magnetosphere. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Hartle, RE (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 910, Greenbelt, MD 20771 USA. EM richard.e.hartle@nasa.gov NR 41 TC 8 Z9 8 U1 1 U2 1 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 14 PY 2007 VL 112 IS A7 AR A07104 DI 10.1029/2006JA012157 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 190CZ UT WOS:000248036900001 ER PT J AU Levy, RC Remer, LA Dubovik, O AF Levy, Robert C. Remer, Lorraine A. Dubovik, Oleg TI Global aerosol optical properties and application to Moderate Resolution Imaging Spectroradiometer aerosol retrieval over land SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SKY RADIANCE MEASUREMENTS; TROPOSPHERIC AEROSOL; LIGHT-SCATTERING; SIZE DISTRIBUTION; PARTICLES; MODIS; AERONET; SUN; ASSESSMENTS; SPHEROIDS AB As more information about global aerosol properties has become available from remotely sensed retrievals and in situ measurements, it is prudent to evaluate this new information, both on its own and in the context of satellite retrieval algorithms. Using the climatology of almucantur retrievals from global Aerosol Robotic Network (AERONET) Sun photometer sites, we perform cluster analysis to determine aerosol type as a function of location and season. We find that three spherical-derived types (describing fine-sized dominated aerosol) and one spheroid-derived types (describing coarse-sized dominated aerosol, presumably dust) generally describe the range of AERONET observed global aerosol properties. The fine-dominated types are separated mainly by their single scattering albedo (omega(0)), ranging from nonabsorbing aerosol (omega(0)similar to 0.95) in developed urban/industrial regions, to moderately absorbing aerosol (omega(0)similar to 0.90) in forest fire burning and developing industrial regions, to absorbing aerosol (omega(0)similar to 0.85) in regions of savanna/grassland burning. We identify the dominant aerosol type at each site, and extrapolate to create seasonal 1 degrees x1 degrees maps of expected aerosol types. Each aerosol type is bilognormal, with dynamic (function of optical depth) size parameters (radius, standard deviation, volume distribution) and complex refractive index. Not only are these parameters interesting in their own right, they can also be applied to aerosol retrieval algorithms, such as to aerosol retrieval over land from Moderate Resolution Imaging Spectroradiometer. Independent direct-Sun AERONET observations of spectral aerosol optical depth (tau) are consistent the spectral dependence of the models, indicating that our derived aerosol models are relevant. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. Univ Sci & Tech Lille Flandres Artois, Opt Atmospher Lab, Villeneuve Dascq, France. RP Levy, RC (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Atmospheres Lab, Code 613-2, Greenbelt, MD 20771 USA. RI Dubovik, Oleg/A-8235-2009; Levy, Robert/M-7764-2013 OI Dubovik, Oleg/0000-0003-3482-6460; Levy, Robert/0000-0002-8933-5303 NR 35 TC 702 Z9 723 U1 11 U2 57 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 13 PY 2007 VL 112 IS D13 AR D13210 DI 10.1029/2006JD007815 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 190AP UT WOS:000248030400003 ER PT J AU Levy, RC Remer, LA Mattoo, S Vermote, EF Kaufman, YJ AF Levy, Robert C. Remer, Lorraine A. Mattoo, Shana Vermote, Eric F. Kaufman, Yoram J. TI Second-generation operational algorithm: Retrieval of aerosol properties over land from inversion of Moderate Resolution Imaging Spectroradiometer spectral reflectance SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OPTICAL DEPTH; SURFACE REFLECTANCE; MODIS; OCEAN; PRODUCTS; POLARIZATION; ATMOSPHERE; SCATTERING; RADIANCES; NETWORK AB Since first light in early 2000, operational global quantitative retrievals of aerosol properties over land have been made from Moderate Resolution Imaging Spectroradiometer (MODIS) observed spectral reflectance. These products have been continuously evaluated and validated, and opportunities for improvements have been noted. We have replaced the surface reflectance assumptions, the set of aerosol model optical properties, and the aerosol lookup table (LUT). This second-generation operational algorithm performs a simultaneous inversion of two visible (0.47 and 0.66 mu m) and one shortwave-IR (2.12 mu m) channel, making use of the coarse aerosol information content contained in the 2.12 mu m channel. Inversion of the three channels yields three nearly independent parameters, the aerosol optical depth (tau) at 0.55 mu m, the nondust or fine weighting (eta), and the surface reflectance at 2.12 mu m. Retrievals of small-magnitude negative tau values (down to -0.05) are considered valid, thus balancing the statistics of tau in near zero tau conditions. Preliminary validation of this algorithm shows much improved retrievals of tau, where the MODIS/Aerosol Robotic Network tau (at 0.55 mu m) regression has an equation of: y = 1.01x + 0.03, R = 0.90. Global mean tau for the test bed is reduced from similar to 0.28 to similar to 0.21. C1 Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. RP Levy, RC (reprint author), Sci Syst & Applicat Inc, 10210 Greenbelt Rd,Suite 600, Lanham, MD 20706 USA. RI Levy, Robert/M-7764-2013; Vermote, Eric/K-3733-2012 OI Levy, Robert/0000-0002-8933-5303; NR 43 TC 9 Z9 37 U1 5 U2 16 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 13 PY 2007 VL 112 IS D13 AR D13211 DI 10.1029/2006JD007811 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 190AP UT WOS:000248030400002 ER PT J AU Uritsky, VM Paczuski, M Davila, JM Jones, SI AF Uritsky, Vadim M. Paczuski, Maya Davila, Joseph M. Jones, Shaela I. TI Coexistence of self-organized criticality and intermittent turbulence in the solar corona SO PHYSICAL REVIEW LETTERS LA English DT Article ID EUV TRANSIENT BRIGHTENINGS; FOREST-FIRE MODEL; MAGNETOHYDRODYNAMIC TURBULENCE; QUIET SUN; STATISTICAL-ANALYSIS; AVALANCHE DYNAMICS; NANOFLARES; FLARES; SOHO; EIT AB An extended data set of extreme ultraviolet images of the solar corona provided by the SOHO spacecraft is analyzed using statistical methods common to studies of self-organized criticality (SOC) and intermittent turbulence (IT). The data exhibit simultaneous hallmarks of both regimes: namely, power-law avalanche statistics as well as multiscaling of structure functions for spatial activity. This implies that both SOC and IT may be manifestations of a single complex dynamical process entangling avalanches of magnetic energy dissipation with turbulent particle flows. C1 Univ Calgary, Dept Phys & Astron, Complex Sci Grp, Calgary, AB T2N 1N4, Canada. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, College Pk, MD 20742 USA. RP Uritsky, VM (reprint author), Univ Calgary, Dept Phys & Astron, Complex Sci Grp, Calgary, AB T2N 1N4, Canada. EM vuritsky@phas.ucalgary.ca NR 45 TC 39 Z9 39 U1 0 U2 2 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 13 PY 2007 VL 99 IS 2 AR 025001 DI 10.1103/PhysRevLett.99.025001 PG 4 WC Physics, Multidisciplinary SC Physics GA 189XD UT WOS:000248021000028 PM 17678227 ER PT J AU Barth, MC Kim, SW Skamarock, WC Stuart, AL Pickering, KE Ott, LE AF Barth, M. C. Kim, S.-W. Skamarock, W. C. Stuart, A. L. Pickering, K. E. Ott, L. E. TI Simulations of the redistribution of formaldehyde, formic acid, and peroxides in the 10 July 1996 Stratospheric-Tropospheric Experiment: Radiation, Aerosols, and Ozone deep convection storm SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LIGHTNING-PRODUCED NOX; TRACE GAS-TRANSPORT; SULFUR-DIOXIDE; NUMERICAL SIMULATIONS; CHEMICAL RETENTION; HYDROGEN-PEROXIDE; CLOUD TRANSPORT; RIME ICE; MODEL; CHEMISTRY AB By using a three-dimensional convective cloud model to simulate the 10 July 1996, Stratospheric-Tropospheric Experiment: Radiation, Aerosols, and Ozone-Deep Convection experiment storm, we investigate the fate of formaldehyde (CH2O), formic acid (HCOOH), hydrogen peroxide (H2O2), and methyl hydrogen peroxide (CH3OOH) in an isolated thunderstorm. CH2O, H2O2, and CH3OOH are important HOx radical and ozone (O-3) precursors in the upper troposphere. Thus, determining their source strength to the upper troposphere is important for estimating O-3 production. The model simulates O-3-NOx-CH4 chemistry (no nonmethane hydrocarbon chemistry) which is affected by the cloud microphysics and production of NOx by lightning. The retention of the soluble species within ice, snow, and hail during drop freezing results in less transport of the species to the upper troposphere than when the species is degassed during drop-freezing processes. Aqueous-phase chemistry is found to be inadequate in producing sufficient quantities of HCOOH so that HCOOH could serve as a reliable indicator of cloud-processed air. The production of nitrogen oxides by lightning has little to no effect on convective outflow mixing ratios of CH2O, H2O2, and CH3OOH within 100 km of the convective cores. Thus, it is unlikely that lightning affects concentrations of HOx precursors near active convection. Scavenging of CH2O and H2O2 significantly affects their concentrations in the convective outflow, although H2O2 mixing ratios were still similar to CH3OOH indicating that both peroxides can contribute equally to O-3 production downwind of convection. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Natl Ocean & Atmospher Adm, Earth Syst Res Lab, Boulder, CO USA. Univ Colorado, Cooperat Inst Res Environm Studies, Boulder, CO USA. Univ S Florida, Dept Environm & Occupat Hlth, Tampa, FL USA. Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD USA. NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD USA. RP Barth, MC (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM barthm@ncar.ucar.edu RI Ott, Lesley/E-2250-2012; Pickering, Kenneth/E-6274-2012; Kim, Si-Wan/I-3979-2013; Manager, CSD Publications/B-2789-2015; OI Kim, Si-Wan/0000-0002-7889-189X; Stuart, Amy/0000-0003-1229-4934 NR 59 TC 34 Z9 34 U1 0 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 12 PY 2007 VL 112 IS D13 AR D13310 DI 10.1029/2006JD008046 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 190AN UT WOS:000248030200006 ER PT J AU Vanderbilt, VC Khanna, S Ustin, SL AF Vanderbilt, Vern C. Khanna, Shruti Ustin, Susan L. TI Impact of pixel size on mapping surface water in subsolar imagery SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE subsolar; specular reflection; sun glint; wetland; linear spectral unmixing; spectral mixture analysis ID MULTISPECTRAL IMAGES; ATMOSPHERE; VEGETATION AB We observed surface water in a wetland, imaging in the subsolar or specular direction the exceptionally bright specular reflection of sunlight at aground resolution of 0.3 m. We then simulated ground resolutions between 1.7 m and 1.2 km through aggregation of the 0.3 m pixels. Contrary to the expectations of some of our colleagues in the wetlands community, for these data, the accuracy of spectral mixture analysis (SMA) estimates of surface water increases as pixel ground footprint size increases. Our results suggest that regional to global scale assessments of flooded landscapes and wetlands that do not involve issues requiring I m resolution per se may be addressed with acceptable accuracy by applying SMA techniques to low resolution imagery. Our results indicate within-pixel estimates of surface water area derived from data measured by subsolar viewing sensors with large ground pixel footprints, such as satellite POLarization and Directionality (of Earth Radiance (POLDER) data, may be highly accurate under strong surface wind conditions. (C) 2007 Elsevier Inc. All rights reserved. C1 NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. Univ Calif Davis, Davis, CA 95616 USA. RP Vanderbilt, VC (reprint author), NASA, Ames Res Ctr, Div Earth Sci, MS 242-4, Moffett Field, CA 94035 USA. EM Vern.C.Vanderbilt@nasa.gov NR 12 TC 4 Z9 4 U1 1 U2 6 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 JUL 12 PY 2007 VL 109 IS 1 BP 1 EP 9 DI 10.1016/j.rse.2006.12.009 PG 9 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 178DA UT WOS:000247200200001 ER PT J AU Lanari, R Casu, F Manzo, M Lundgren, P AF Lanari, Riccardo Casu, Francesco Manzo, Mariarosaria Lundgren, Paul TI Application of the SBAS-DInSAR technique to fault creep: A case study of the Hayward fault, California SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE DInSAR; SBAS; surface creep; Hayward fault; alignment arrays ID DIFFERENTIAL SAR INTERFEROGRAMS; LOMA-PRIETA EARTHQUAKE; RADAR INTERFEROMETRY; ALGORITHM; VALLEY; SLIP; SET AB We present a quantitative assessment of the capability of the differential SAR interferometry (DInSAR) technique refer-red to as Small BAseline Subset (SBAS) approach to investigate fault creep phenomena. In particular we have computed, via the SBAS-DInSAR algorithm, time series of the surface displacements relevant to the Hayward fault zone, within the San Francisco Bay Area (California), from the European Space Agency's ERS-1/2 satellite radar data for the 1992 to 2000 time period. Starting from the DInSAR time series we measured the relative displacements across the fault with no need for any atmospheric filtering step. These results have been systematically compared to the measurements available from the alignment arrays that are located along the fault. Our analysis shows that the standard deviation of the differences between the DInSAR and the in situ measurements is on the order of 2 mm. Moreover, the estimated mean deformation rates have an accuracy that is better than 1 mm/year. (C) 2006 Elsevier Inc. All rights reserved. C1 CNR, Ist Rilevamento Elettromagnet Ambiente, I-80125 Naples, Italy. Univ Cagliari, Dipartimento Ingn Elettr & Elettron, Cagliari, Italy. Univ Basilicata, Dipartimento Ingn & Fis Ambiente, I-85100 Potenza, Italy. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Lanari, R (reprint author), CNR, Ist Rilevamento Elettromagnet Ambiente, I-80125 Naples, Italy. EM lanari.r@irea.cnr.it RI Casu, Francesco/H-3793-2011; OI MANZO, MARIAROSARIA/0000-0002-9387-5273; Casu, Francesco/0000-0001-8555-6494 NR 23 TC 43 Z9 45 U1 2 U2 12 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JUL 12 PY 2007 VL 109 IS 1 BP 20 EP 28 DI 10.1016/j.rse.2006.12.003 PG 9 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 178DA UT WOS:000247200200003 ER PT J AU Rault, DF Taha, G AF Rault, Didier F. Taha, Ghassan TI Validation of ozone profiles retrieved from Stratospheric Aerosol and Gas Experiment III limb scatter measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID O-3 PROFILES; ART.; SCIAMACHY; SENSITIVITY; QUALITY; SENSOR AB Ozone profiles retrieved from Stratospheric Aerosol and Gas Experiment (SAGE III) limb scatter measurements are compared with correlative measurements made by occultation instruments (SAGE II, SAGE III, and HALOE), a limb scatter instrument (Optical Spectrograph and Infrared Imager System (OSIRIS)), a series of ozonesondes and lidars, and a transport model, in order to ascertain the accuracy and precision of the SAGE III instrument in limb scatter mode. The measurement relative accuracy is found to be 5-10% from the tropopause to about 45 km, whereas the relative precision is found to be less than 10% from 20 to 38 km. The height registration, which is inferred directly from radiance data profiles, is found to have a standard deviation ("relative precision") of about 350 m. Measurement repeatability, a measure of absolute precision, which is estimated by multiple measurements over the same geographical area in the tropics on consecutive orbits, is found to be similar to 3%. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Rault, DF (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM didier.f.rault@nasa.gov NR 25 TC 11 Z9 12 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-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 11 PY 2007 VL 112 IS D13 AR D13309 DI 10.1029/2006JD007679 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 190AL UT WOS:000248030000002 ER PT J AU Coe, MJ Bird, AJ Hill, AB McBride, VA Schurch, M Galache, J Wilson, CA Finger, M Buckley, DA Romero-Colmenero, E AF Coe, M. J. Bird, A. J. Hill, A. B. McBride, V. A. Schurch, M. Galache, J. Wilson, C. A. Finger, M. Buckley, D. A. Romero-Colmenero, E. TI Now you see it, now you don't - the circumstellar disc in the GRO J1008-57 system SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : neutron; X-rays : binaries ID BE/X-RAY BINARIES; EMISSION; PULSARS; STARS AB Multiwavelength observations are reported here of the Be/X-ray binary pulsar system GRO J1008-57. Over ten years worth of data are gathered together to show that the periodic X-ray outbursts are dependant on both the binary motion and the size of the circumstellar disc. In the first instance an accurate orbital solution is determined from pulse periods, and in the second case the strength and shape of the H alpha emission line is shown to be a valuable indicator of disc size and its behaviour. Furthermore, the shape of the emission line permits a direct determination of the disc size which is in good agreement with theoretical estimates. A detailed study of the pulse period variations during outbursts determined the binary period to be 247.8 +/- 0.4 d, in good agreement with the period determined from the recurrence of the outbursts. C1 Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. S African Astron Observ, ZA-7935 Cape Town, South Africa. RP Coe, MJ (reprint author), Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. EM m.j.cole@soton.ac.uk OI Hill, Adam/0000-0003-3470-4834 NR 20 TC 15 Z9 15 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUL 11 PY 2007 VL 378 IS 4 BP 1427 EP 1433 DI 10.1111/j.1365-2966.2007.11878.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 184UK UT WOS:000247667900020 ER PT J AU Levan, AJ Jakobsson, P Hurkett, C Tanvir, NR Gorosabel, J Vreeswijk, P Rol, E Chapman, R Gehrels, N O'Brien, PT Osborne, JP Priddey, RS Kouveliotou, C Starling, R Berk, DV Wiersema, K AF Levan, A. J. Jakobsson, P. Hurkett, C. Tanvir, N. R. Gorosabel, J. Vreeswijk, P. Rol, E. Chapman, R. Gehrels, N. O'Brien, P. T. Osborne, J. P. Priddey, R. S. Kouveliotou, C. Starling, R. Vanden Berk, D. Wiersema, K. TI A case of mistaken identity? GRB 060912A and the nature of the long-short GRB divide SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE gamma-rays : bursts ID GAMMA-RAY BURST; HOST GALAXY; STAR-FORMATION; VLT SPECTROSCOPY; AFTERGLOW; SUPERNOVA; REDSHIFT; FAINT; PROGENITORS; GRB-050709 AB We investigate the origin of the GRB 060912A, which has observational properties that make its classification as either a long or short burst ambiguous. Short-duration gamma-ray bursts (SGRBs) are thought to have typically lower energies than long-duration bursts, can be found in galaxies with populations of all ages and are likely to originate from different progenitors to the long-duration bursts. However, it has become clear that duration alone is insufficient to make a distinction between the two populations in many cases, leading to a desire to find additional discriminators of burst type. GRB 060912A had a duration of 6 s and occurred only similar to 10 arcsec from a bright, low-redshift (z = 0.0936) elliptical galaxy, suggesting that this may have been the host, which would favour it being a short burst. However, our deep optical imaging and spectroscopy of the location of GRB 060912A using the Very Large Telescope (VLT) shows that GRB 060912A more likely originates in a distant star-forming galaxy at z = 0.937, and is most likely a long burst. This demonstrates the risk in identifying bright, nearby galaxies as the hosts of given gamma-ray bursts (GRBs) without further supporting evidence. Further, it implies that, in the absence of secure identifications, 'host' type, or more broadly discriminators that rely on galaxy redshifts, may not be good indicators of the true nature of any given GRB. C1 Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Univ Hertfordshire, Ctr Astrophys Res, Hatfield AL10 9AB, Herts, England. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Inst Astrofis Andalucia, CSIC, IAA, E-18080 Granada, Spain. European So Observ, Santiago, Chile. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. RP Levan, AJ (reprint author), Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. EM a.j.levan@warwick.ac.uk RI Gehrels, Neil/D-2971-2012; Jakobsson, Pall/L-9950-2015 OI Jakobsson, Pall/0000-0002-9404-5650 NR 59 TC 30 Z9 30 U1 0 U2 1 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 JUL 11 PY 2007 VL 378 IS 4 BP 1439 EP 1446 DI 10.1111/j.1365-2966.2007.11879.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 184UK UT WOS:000247667900022 ER PT J AU She, CY Yue, J Yan, ZA Hair, JW Guo, JJ Wu, SH Liu, ZS AF She, Chiao-Yao Yue, Jia Yan, Zhao-Ai Hair, Johnathan W. Guo, Jin-Jia Wu, Song-Hua Liu, Zhi-Shen TI Direct-detection Doppler wind measurements with a Cabannes-Mile lidar: A. Comparison between iodine vapor filter and Fabry-Perot interferometer methods SO APPLIED OPTICS LA English DT Article ID EDGE TECHNIQUE; MIDDLE ATMOSPHERE; MESOPAUSE REGION; RADIAL WIND; TEMPERATURE; WAVELENGTHS; RESOLUTION AB Atmospheric line-of-sight (LOS) wind measurement by means of incoherent Cabannes-Mie lidar with three frequency analyzers with nearly the same maximum transmission of similar to 80% that could be fielded at different wavelengths is analytically considered. These frequency analyzers are (a) a double-edge Fabry-Perot interferometer (FPI) at 1064 nm (IR-FPI), (b) a double-edge Fabry-Perot interferometer at 355 nm (UV-FPI), and (c) an iodine vapor filter (IVF) at 532 nm with two different methods, using either one absorption edge, single edge (se-IVF), or both absorption edges, double edge (de-IVF). The effect of the backscattered aerosol mixing ratio, R-b, defined as the ratio of the aerosol volume backscatter coefficient to molecular volume backscatter coefficient, on LOS wind uncertainty is discussed. Assuming a known aerosol mixing ratio, R-b, and 100,000 photons owing to Cabannes scattering to the receiver, in shot-noise-limited detection without sky background, the LOS wind uncertainty of the UV-FPI in the aerosol-free air (R-b = 0), is lower by similar to 16% than that of de-IVF, which has the lowest uncertainty for R-b between 0.02 and 0.08; for R-b > 0.08, the IR-FPI yielded the lowest wind uncertainty. The wind uncertainty for se-IVF is always higher than that of de-IVF, but by less than a factor of 2 under all aerosol conditions, if the split between the reference and measurement channels is optimized. The design flexibility, which allows the desensitization of either aerosol or molecular scattering, exists only with the FPI system, leading to the common practice of using IR-FPI for the planetary boundary layer and using UV-FPI for higher altitudes. Without this design flexibility, there is little choice but to use a single wavelength IVF system at 532 ran for all atmospheric altitudes. (C) 2007 Optical Society of America. C1 Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. Ocean Univ China, Ocean Remote Sensing Inst, Qingdao 266003, Peoples R China. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP She, CY (reprint author), Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. EM joeshe@lamar.colostate.edu RI Yue, Jia/D-8177-2011 NR 32 TC 18 Z9 21 U1 2 U2 12 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD JUL 10 PY 2007 VL 46 IS 20 BP 4434 EP 4443 DI 10.1364/AO.46.004434 PG 10 WC Optics SC Optics GA 184TL UT WOS:000247665000027 PM 17579699 ER PT J AU She, CY Yue, J Yan, ZA Hair, JW Guo, JJ Wu, SH Liu, ZS AF She, Chiao-Yao Yue, Jia Yan, Zhao-Ai Hair, Johnathan W. Guo, Jin-Jia Wu, Song-Hua Liu, Zhi-Shen TI Direct-detection Doppler wind measurements with a Cabannes-Mie lidar: B. Impact of aerosol variation on iodine vapor filter methods SO APPLIED OPTICS LA English DT Article ID WAVELENGTHS AB Atmospheric line-of-sight (LOS) wind measurement by means of incoherent Cabannes-Mie lidar with three frequency analyzers, two double-edge Fabry-Perot interferometers, one at 1064 nm (IR-FPI) and another at 355 nm (UV-FPI), as well as an iodine vapor filter (IVF) at 532 nm, utilizing either a single absorption edge, single edge (se-IVF), or both absorption edges, double edge (de-IVF), was considered in a companion paper [Appl. Opt. 46, 4434 (2007)], assuming known atmospheric temperature and aerosol mixing ratio, R-b. The effects of temperature and aerosol variations on the uncertainty of LOS wind measurements are investigated and it is found that while the effect of temperature variation is small, the variation in R-b can cause significant errors in wind measurements with IVF systems. Thus the means to incorporate a credible determination of R-b into the wind measurement are presented as well as an assessment of the impact on wind measurement uncertainty. Unlike with IVF methods, researchers can take advantage of design flexibility with FPI methods to desensitize either molecular scattering for IR-FPI or aerosol scattering for UV-FPI. The additional wind measurement uncertainty caused by R-b variation with FPI methods is thus negligible for these configurations. Assuming 100,000 photons from Cabannes scattering, and accounting for the R-b measurement incorporated into the IVF method in this paper, it is found that the lowest wind uncertainty at low wind speeds in aerosol-free air is still with UV-FPI, similar to 32% lower than with de-IVF. For 0.05 < R-b < 0.07, the LOS wind uncertainty is lowest with de-IVF, and for R-b > 0.07, the IR-FPI outperforms all other methods. In addition to LOS wind uncertainty comparison under high wind speed conditions, the need of an appropriate and readily available narrowband filter for operating the wind lidar at visible wavelengths under sunlit condition is discussed; with such a filter the degradation of LOS wind measurement attributable to clear sky background is estimated to be 5% or less for practical lidar systems. (C) 2007 Optical Society of America. C1 Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. Ocean Univ China, Ocean Remote Sensing Inst, Qingdao 266003, Peoples R China. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP She, CY (reprint author), Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. EM joeshe@lamar.colostate.edu RI Yue, Jia/D-8177-2011 NR 21 TC 13 Z9 15 U1 1 U2 11 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 JUL 10 PY 2007 VL 46 IS 20 BP 4444 EP 4454 DI 10.1364/AO.46.004444 PG 11 WC Optics SC Optics GA 184TL UT WOS:000247665000028 PM 17579700 ER PT J AU Muchovej, S Mroczkowski, T Carlstrom, JE Cartwright, J Greer, C Hennessy, R Loh, M Pryke, C Reddall, B Runyan, M Sharp, M Hawkins, D Lamb, JW Woody, D Joy, M Leitch, EM Miller, AD AF Muchovej, Stephen Mroczkowski, Tony Carlstrom, John E. Cartwright, John Greer, Christopher Hennessy, Ryan Loh, Michael Pryke, Clem Reddall, Ben Runyan, Marcus Sharp, Matthew Hawkins, David Lamb, James W. Woody, David Joy, Marshall Leitch, Erik M. Miller, Amber D. TI Observations of high-redshift x-ray selected clusters with the Sunyaev-Zel'dovich array SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations; galaxies : clusters : individual (Cl J1226.9+3332, Cl J1415.1+3612 Cl J1429.0+4241); galaxies : individual (NGC 5529); techniques : interferometric ID EFFECT SCALING RELATIONS; COSMIC DISTANCE SCALE; GALAXY CLUSTER; INTRACLUSTER MEDIUM; CONSTRAINTS; SPECTROSCOPY; TELESCOPE; COSMOLOGY; DISCOVERY; PROFILES AB We report measurements of the Sunyaev- Zel'dovich ( SZ) effect in three high- redshift ( 0. 89 <= z <= 1. 03), X- ray selected galaxy clusters. The observations were obtained at 30 GHz during the commissioning period of a new, eightelement interferometer - the Sunyaev- Zel'dovich Array ( SZA) - built for dedicated SZ effect observations. The SZA observations are sensitive to angular scales larger than those subtended by the virial radii of the clusters. Assuming isothermality and hydrostatic equilibrium for the intracluster medium and gas- mass fractions consistent with those for clusters at moderate redshift, we calculate electron temperatures, gas masses, and total cluster masses from the SZ data. The SZ- derived masses, integrated approximately to the virial radii, are 1: 9(-0.4)(+0. 5) X10(14) M-circle dot for Cl J1415.1+ 3612, 3: 4(+0. 6) (- 0.5) X 10(14) M-circle dot for Cl J1429.0+ 4241, and 7(-0.9)(+1.3) X10(14) M-circle dot for Cl J1226.9+ 3332. The SZ- derived quantities are in good agreement with the cluster properties derived from X- ray measurements. C1 Columbia Univ, Dept Astron, New York, NY 10027 USA. Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA. CALTECH, Owens Valley Radio Observ, Big Pine, CA 93513 USA. NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. NASA, Jet Propuls Lab, Pasadena, CA 91109 USA. Columbia Univ, Columbia Astrophys Lab, Dept Phys, New York, NY 10027 USA. RP Muchovej, S (reprint author), Columbia Univ, Dept Astron, New York, NY 10027 USA. OI Mroczkowski, Tony/0000-0003-3816-5372 NR 39 TC 69 Z9 69 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 JUL 10 PY 2007 VL 663 IS 2 BP 708 EP 716 DI 10.1086/511971 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500002 ER PT J AU Draine, BT Dale, DA Bendo, G Gordon, KD Smith, JDT Armus, L Engelbracht, CW Helou, G Kennicutt, RC Li, A Roussel, H Walter, F Calzetti, D Moustakas, J Murphy, EJ Rieke, GH Bot, C Hollenbach, DJ Sheth, K Teplitz, HI AF Draine, B. T. Dale, D. A. Bendo, G. Gordon, K. D. Smith, J. D. T. Armus, L. Engelbracht, C. W. Helou, G. Kennicutt, R. C., Jr. Li, A. Roussel, H. Walter, F. Calzetti, D. Moustakas, J. Murphy, E. J. Rieke, G. H. Bot, C. Hollenbach, D. J. Sheth, K. Teplitz, H. I. TI Dust masses, PAH abundances, and starlight intensities in the SINGS galaxy sample SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust; extinction; galaxies : abundances; galaxies : general; galaxies : ISM; infrared : galaxies; ISM : general ID AROMATIC-HYDROCARBON EMISSION; SPECTRAL ENERGY-DISTRIBUTION; SMALL-MAGELLANIC-CLOUD; SPITZER-SPACE-TELESCOPE; COMPACT DWARF GALAXIES; LOW-METALLICITY ENVIRONMENTS; AMORPHOUS-CARBON GRAINS; INFRARED ARRAY CAMERA; STAR-FORMING GALAXIES; TO-GAS RATIO AB Physical dust models are presented for 65 galaxies in SINGS that are strongly detected in the four IRAC bands and three MIPS bands. For each galaxy we estimate ( 1) the total dust mass, ( 2) the fraction of the dust mass contributed by PAHs, and ( 3) the intensity of the starlight heating the dust grains. We find that spiral galaxies have dust properties resembling the dust in the local region of the MilkyWay, with similar dust- to- gas ratio and similar PAH abundance. The observed SEDs, including galaxies with SCUBA photometry, can be reproduced by dust models that do not require `` cold'' ( T less than or similar to 10 K) dust. The dust- to- gas ratio is observed to be dependent on metallicity. In the interstellar media of galaxies with A(O) equivalent to 12 + log(10)( O/ H) > 8: 1, grains contain a substantial fraction of interstellar Mg, Si, and Fe. Galaxies with AO < 8: 1 and extended H I envelopes in some cases appear to have global dust- to- gas ratios that are low for their measured oxygen abundance, but the dust- to- gas ratio in the regions where infrared emission is detected generally appears to be consistent with a substantial fraction of interstellar Mg, Si, and Fe being contained in dust. The PAH index qPAH, the fraction of the dust mass in the form of PAHs, correlates with metallicity. The nine galaxies in our sample with AO < 8: 1 have a median qPAH 1: 0%, whereas galaxies with AO > 8: 1 have a median qPAH 3: 55%. The derived dust masses favor a value XCO approximate to 4.1020 cm(-2) ( K km s(-1))(-1) for the CO- to- H-2 conversion factor. Except for some starbursting systems ( Mrk 33, Tol 89, NGC 3049), dust in the diffuse ISMdominates the IR power. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2AZ, England. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Space Telescope Sci Inst, Baltimore, MD 21218 USA. NYU, Dept Phys, New York, NY 10003 USA. Yale Univ, Dept Astron, New Haven, CT 06520 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Draine, BT (reprint author), Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. EM draine@astro.princeton.edu; ddale@uwyo.edu; g.bendo@imperial.ac.uk; kgordon@as.arizona.edu; jdsmith@as.arizona.edu; lee@ipac.caltech.edu; cengelbracht@as.arizona.edu; gxh@ipac.caltech.edu; robk@ast.cam.ac.uk; lia@missouri.edu; roussel@mpia-hd.mpg.de; walter@mpia.de; calzetti@stsci.edu; johnmoustakas@nyu.edu; murphy@astro.yale.edu; bot@caltech.edu; hollenba@ismarc.nasa.gov; lee@ipac.caltech; hit@ipac.caltech.edu OI Bot, Caroline/0000-0001-6118-2985; Draine, Bruce/0000-0002-0846-936X NR 95 TC 459 Z9 461 U1 3 U2 18 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 2007 VL 663 IS 2 BP 866 EP 894 DI 10.1086/518306 PN 1 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500016 ER PT J AU Takami, K Yamazaki, R Sakamoto, T Sato, G AF Takami, Kentaro Yamazaki, Ryo Sakamoto, Takanori Sato, Goro TI Probing the structure of gamma-ray burst jets with the steep decay phase of their early X-ray afterglows SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; gamma rays : theory ID LIGHT CURVES; PEAK ENERGY; RELATIVISTIC JETS; POSSIBLE ORIGIN; MODEL; UNIVERSAL; EMISSION; FLASHES; ANGLE; CONFIGURATION AB We show that the jet structure of gamma-ray bursts (GRBs) can be investigated with the tail emission of the prompt GRB. The tail emission that we consider is identified as a steep decay component of the early X-ray afterglow observed by the X-Ray Telescope on board Swift. Using a Monte Carlo method, we derive for the first time the distribution of the decay index of the GRB tail emission for various jet models. The new definitions of the zero of time and the time interval of a fitting region are proposed. These definitions for fitting the light curve lead us to a unique definition of the decay index, which is useful to investigate the structure of the GRB jet. We find that if the GRB jet has a core-envelope structure, the predicted distribution of the decay index of the tail has a wide scatter and multiple peaks, which cannot be seen for the case of the uniform and the Gaussian jet. Therefore, the decay index distribution gives us information about the jet structure. Especially if we observe events whose decay index is less than about 2, both the uniform and the Gaussian jet models will be disfavored, according to our simulation study. C1 Hiroshima Univ, Dept Phys, Hiroshima 7398526, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Takami, K (reprint author), Hiroshima Univ, Dept Phys, Hiroshima 7398526, Japan. EM takami@theo.phys.sci.hiroshima-u.ac.jp; ryo@theo.phys.sci.hiroshima-u.ac.jp NR 46 TC 3 Z9 3 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2007 VL 663 IS 2 BP 1118 EP 1124 DI 10.1086/518763 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500034 ER PT J AU Page, KL Willingale, R Osborne, JP Zhang, B Godet, O Marshall, FE Melandri, A Norris, JP O'Brien, PT Pal'shin, V Rol, E Romano, P Starling, RLC Schady, P Yost, SA Barthelmy, SD Beardmore, AP Cusumano, G Burrows, DN De Pasquale, M Ehle, M Evans, PA Gehrels, N Goad, MR Golenetskii, S Guidorzi, C Mundell, C Page, MJ Ricker, G Sakamoto, T Schaefer, BE Stamatikos, M Troja, E Ulanov, M Yuan, F Ziaeepour, H AF Page, K. L. Willingale, R. Osborne, J. P. Zhang, B. Godet, O. Marshall, F. E. Melandri, A. Norris, J. P. O'Brien, P. T. Pal'shin, V. Rol, E. Romano, P. Starling, R. L. C. Schady, P. Yost, S. A. Barthelmy, S. D. Beardmore, A. P. Cusumano, G. Burrows, D. N. De Pasquale, M. Ehle, M. Evans, P. A. Gehrels, N. Goad, M. R. Golenetskii, S. Guidorzi, C. Mundell, C. Page, M. J. Ricker, G. Sakamoto, T. Schaefer, B. E. Stamatikos, M. Troja, E. Ulanov, M. Yuan, F. Ziaeepour, H. TI GRB 061121: Broadband spectral evolution through the prompt and afterglow phases of a bright burst SO ASTROPHYSICAL JOURNAL LA English DT Review DE gamma rays : bursts; X-rays : individual (GRB 061121) ID GAMMA-RAY BURST; INFRARED EXTINCTION LAW; HIGH-REDSHIFT GALAXIES; LIGHT CURVES; PEAK ENERGY; THEORETICAL IMPLICATIONS; BATSE OBSERVATIONS; EMISSION-SPECTRA; MAGELLANIC CLOUD; MOLECULAR CLOUD AB Swift triggered on a precursor to the main burst of GRB 061121 ( z = 1.314), allowing observations to be made from the optical to gamma-ray bands. Many other telescopes, including Konus-Wind, XMM-Newton, ROTSE, and the Faulkes Telescope North, also observed the burst. The gamma-ray, X-ray, and UV/optical emission all showed a peak similar to 75 s after the trigger, although the optical and X-ray afterglow components also appear early on, before or during the main peak. Spectral evolution was seen throughout the burst, with the prompt emission showing a clear positive correlation between brightness and hardness. The SED of the prompt emission, stretching from 1 eV up to 1 MeV, is very flat, with a peak in the flux density at similar to 1 keV. The optical to X-ray spectra at this time are better fitted by a broken, rather than single, power law, similar to previous results for X-ray flares. The SED shows spectral hardening as the afterglow evolves with time. This behavior might be a symptom of self-Comptonization, although circumstellar densities similar to those found in the cores of molecular clouds would be required. The afterglow also decays too slowly to be accounted for by the standard models. Although the precursor and main emission show different spectral lags, both are consistent with the lag-luminosity correlation for long bursts. GRB 061121 is the instantaneously brightest long burst yet detected by Swift. Using a combination of Swift and Konus-Wind data, we estimate an isotropic energy of 2: 8 x 10(53) ergs over 1 keV-10 MeV in the GRB rest frame. A probable jet break is detected at similar to 2 x 10(5) s, leading to an estimate of similar to 10(51) ergs for the beaming-corrected gamma-ray energy. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. Univ Denver, Denver Res Inst, Denver, CO 80208 USA. AF Ioffe Phys Tech Inst, Expt Astrophys Lab, St Petersburg 194021, Russia. Osserv Astron Brera, Ist Nazl Astrofis, I-23807 Merate, LC, Italy. Univ Milan, Dipartimento Fis, I-20126 Milan, Italy. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Univ Michigan, Ann Arbor, MI 48104 USA. INAF, IASF, Sez Palermo, I-90146 Palermo, Italy. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. European Space Agcy, XMM, Newton Sci Operat Ctr, E-28080 Madrid, Spain. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. RP Page, KL (reprint author), Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. EM kpa@star.le.ac.uk RI Barthelmy, Scott/D-2943-2012; Gehrels, Neil/D-2971-2012; Pal'shin, Valentin/F-3973-2014; Ulanov, Mikhail/B-3467-2015; Golenetskii, Sergey/B-3818-2015; OI Ulanov, Mikhail/0000-0002-0076-5228; Cusumano, Giancarlo/0000-0002-8151-1990 NR 141 TC 85 Z9 86 U1 0 U2 5 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 2007 VL 663 IS 2 BP 1125 EP 1138 DI 10.1086/518821 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500035 ER PT J AU Harvey, PM Rebull, LM Brooke, T Spiesman, WJ Chapman, N Huard, TL Evans, NJ Cieza, L Lai, SP Allen, LE Mundy, LG Padgett, DL Sargent, AI Stapelfeldt, KR Myers, PC van Dishoeck, EF Blake, GA Koerner, DW AF Harvey, Paul M. Rebull, Luisa M. Brooke, Tim Spiesman, William J. Chapman, Nicholas Huard, Tracy L. Evans, Neal J., II Cieza, Lucas Lai, Shih-Ping Allen, Lori E. Mundy, Lee G. Padgett, Deborah L. Sargent, Anneila I. Stapelfeldt, Karl R. Myers, Philip C. van Dishoeck, Ewine F. Blake, Geoffrey A. Koerner, David W. TI The Spitzer c2d survey of large, nearby, interstellar clouds. VIII. Serpens observed with MIPS SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : general ID YOUNG STELLAR POPULATION; MOLECULAR CLOUD; CORE; IRAC; CONTINUUM; PERSEUS; PROGRAM; SKY AB We present maps of 1.5 deg(2) of the Serpens dark cloud at 24, 70, and 160 mu m observed with the Spitzer Space Telescope MIPS camera. We describe the observations and briefly discuss the data processing carried out by the c2d team on these data. More than 2400 compact sources have been extracted at 24 mu m, nearly 100 at 70 mu m, and four at 160 mu m. We estimate completeness limits for our 24 mu m survey from Monte Carlo tests with artificial sources inserted into the Spitzer maps. We compare source counts, colors, and magnitudes in the Serpens cloud to two reference data sets: a 0.50 deg(2) set on a low-extinction region near the dark cloud, and a 5.3 deg(2) subset of the SWIRE ELAIS N1 data that was processed through our pipeline. These results show that there is an easily identifiable population of young stellar object candidates in the Serpens cloud that is not present in either of the reference data sets. We also show a comparison of visual extinction and cool dust emission illustrating a close correlation between the two and find that the most embedded YSO candidates are located in the areas of highest visual extinction. C1 Univ Texas, Dept Astron, Austin, TX 78712 USA. Spitzer Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. No Arizona Univ, Dept Phys & Astron, Flagstaff, AZ 86011 USA. RP Harvey, PM (reprint author), Univ Texas, Dept Astron, RLM 15308, Austin, TX 78712 USA. EM pmh@astro.as.utexas.edu; rebull@ipac.caltech.edu; tyb@astro.caltech.edu; spies@astro.as.utexas.edu; chapman@astro.umd.edu; thuard@cfa.harvard.edu; nje@astro.as.utexas.edu; lcieza@astro.as.utexas.edu; slai@astro.umd.edu; leallen@cfa.harvard.edu; lgm@astro.umd.edu; dlp@ipac.caltech.edu; afs@astro.caltech.edu; krs@exoplanet.jpl.nasa.gov; pmyers@cfa.harvard.edu; ewine@strw.leidenuniv; gab@gps.caltech.edu; koerner@physics.nau.edu RI Stapelfeldt, Karl/D-2721-2012; OI Rebull, Luisa/0000-0001-6381-515X NR 24 TC 45 Z9 45 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 JUL 10 PY 2007 VL 663 IS 2 BP 1139 EP 1148 DI 10.1086/518647 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500036 ER PT J AU Bradshaw, CF Titarchuk, L Kuznetsov, S AF Bradshaw, Charles F. Titarchuk, Lev Kuznetsov, Sergey TI Correlations between X-ray spectral characteristics and quasi-periodic oscillations in Scorpius X-1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; stars : individual (Scorpius X-1); stars : neutron; X-rays : individual (Scorpius X-1) ID NEUTRON-STAR BINARIES; BOUNDARY-LAYER; BLACK-HOLE; TIMING BEHAVIOR; X-1; ACCRETION; RADIATION; BRANCH; INDEX; FLUX AB Correlations between 1-10 Hz quasi-periodic oscillations (QPOs) and spectral power-law index have been reported for black hole (BH) candidate sources and one neutron star source, 4U 1728-34. An examination of QPO frequency and index relationships in Sco X-1 is reported here. We discover that Sco X-1, representing Z-source groups, can be adequately modeled by a simple two-component model of Compton up-scattering with a soft photon electron temperature of about 0.4 keV, plus an Iron K line. The results show a strong correlation between spectral power-law index and kHz QPOs. Because Sco X-1 radiates near the Eddington limit, one can infer that the geometrical configuration of the Compton cloud ( CC) is quasi-spherical from high radiation pressure in the CC. Thus, we conclude that the high Thomson optical depth of the Compton cloud, in the range of similar to 5-6 from the best-fit model parameters, is consistent with the neutron star's surface being obscured by material. Moreover, a spin frequency of Sco X-1 is likely suppressed due to photon scattering off CC electrons. In addition, we demonstrate how the power spectrum evolves when Sco X-1 transitions from the horizontal branch to the normal branch. C1 Mitre Corp, Mclean, VA 22102 USA. George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. USN, Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Riverside, Inst Geophys & Planetary Phys, Riverside, CA 92521 USA. Russian Acad Sci, Inst Space Res, Moscow 117997, Russia. RP Bradshaw, CF (reprint author), Mitre Corp, 7525 Colshire Dr, Mclean, VA 22102 USA. EM cbradshaw@miter.org; ltitarchuk@ssd5.nrl.navy.mil; sergeyk@ucr.edu NR 30 TC 10 Z9 10 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2007 VL 663 IS 2 BP 1225 EP 1231 DI 10.1086/518107 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500044 ER PT J AU Caballero-Lopez, RA Moraal, H Mewaldt, RA McDonald, FB Wiedenbeck, ME AF Caballero-Lopez, R. A. Moraal, H. Mewaldt, R. A. McDonald, F. B. Wiedenbeck, M. E. TI Cosmic-ray energy changes in the heliosphere. II. The effect on K-capture electron secondaries SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic rays; Sun : particle emission ID WIND TERMINATION SHOCK; FORCE-FIELD EQUATION; HELIOSHEATH; MODULATION AB Recent accurate measurements of the cosmic-ray intensity ratio V-51/Cr-51 below 1 GeV nucleon(-1) provide a powerful new tool to study cosmic-ray modulation in the heliosphere. This paper describes how energy changes during this modulation process influence this ratio. In particular, our model includes acceleration at the solar wind termination shock, and we find that this mechanism significantly enhances the V-51/Cr-51 ratio at 1 AU. It is also shown that this acceleration makes the ratio more sensitive to the form of local low-energy interstellar spectra, below similar to 100 MeV nucleon similar to 1, than without it. Specifically, this acceleration provides an independent confirmation of the consensus that low-energy spectra should be flatter than their high-energy power-law forms. C1 Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico. NW Univ, Sch Phys, ZA-2520 Potchefstroom, South Africa. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Caballero-Lopez, RA (reprint author), Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico. EM rogelioc@geofisica.unam.mx OI Caballero, Rogelio/0000-0001-8954-1927 NR 14 TC 2 Z9 2 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 JUL 10 PY 2007 VL 663 IS 2 BP 1335 EP 1339 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500055 ER PT J AU Krall, J Sterling, AC AF Krall, Jonathan Sterling, Alphonse C. TI Analysis of erupting solar prominences in terms of an underlying flux-rope configuration SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : coronal mass ejections (CMEs); Sun : magnetic fields; Sun : prominences ID CORONAL MASS EJECTIONS; INTERPLANETARY MAGNETIC CLOUDS; QUIESCENT PROMINENCES; MODEL; FILAMENT; FIELD; EVOLUTION; GEOMETRY; TOPOLOGY; ACCELERATION AB Data from four solar prominence eruptions are analyzed so as to examine the flux-rope configuration at the onset of eruption and to test specific aspects of an analytic flux-rope model of solar eruptions. The model encompasses both prominence eruptions and coronal mass ejections (CMEs) as generic elements of a typical erupting flux-rope structure. The hypothesized relationship between prominence footpoint separation and prominence acceleration profile is examined, as is the hypothesized geometrical relationship between the prominence and the CME leading edge (LE). While the simple model does not account for some observed features, the prominence and "loop'' (LE) data are shown to be consistent with both the geometrical model and the theoretical acceleration profile. This analysis further suggests that the onset of eruption is associated with a situation in which the underlying flux-rope geometry maximizes the outward magnetic "hoop'' force. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. NASA, Marshall Space Flight Ctr, SD50 Space Sci Dept, Huntsville, AL 35182 USA. RP Krall, J (reprint author), USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. NR 68 TC 5 Z9 5 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 JUL 10 PY 2007 VL 663 IS 2 BP 1354 EP 1362 DI 10.1086/518400 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500057 ER PT J AU Reiner, MJ Kaiser, ML Bougeret, JL AF Reiner, M. J. Kaiser, M. L. Bougeret, J.-L. TI Coronal and interplanetary propagation of cme/shocks from radio, in situ and white-light observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE solar-terrestrial relations; Sun : activity; Sun : corona; Sun : coronal mass ejections (CMEs); Sun : flares; Sun : radio radiation ID MASS EJECTION EVENTS; LASCO OBSERVATIONS; SOLAR CORONA; ELECTRON-DENSITY; WIND SPACECRAFT; SHOCK-WAVES; LARGE-ANGLE; BURSTS; ORIGIN; EVOLUTION AB The kinematics of CMEs are well characterized to 32 R(circle dot) by height-time measurements from existing space-based and ground-based coronagraphs. Although there has been long-standing, but indirect, evidence that CMEs can exhibit significant deceleration as they propagate from Sun to Earth, the interplanetary kinematics of CMEs are not presently well understood. Since white-light measurements beyond 30 R(circle dot) have only recently become available, quantitative information on the interplanetary kinematics of CMEs have hitherto been provided primarily by remote radio observations. Using the constraints imposed by the low-frequency radio emissions generated by shocks driven by CMEs, the measured 1 AU transit times and the calculated in situ shock speeds, together with the required consistency with the white-light measurements, we provide a comprehensive quantitative analysis of the interplanetary transport of 42 CME/shocks observed during solar cycle 23. The analyses of these events provide insights into when, where, and how fast CMEs decelerate as they propagate through the corona and interplanetary medium. The results of our analyses show that, while there are wide variations in the kinematics for the individual CME events, there are some notable correlations between the parameters that characterize the deceleration of these CMEs to 1 AU. C1 Catholic Univ Amer, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Space Weather Lab, Greenbelt, MD 20771 USA. LESIA, Observ Paris, Meudon, France. RP Reiner, MJ (reprint author), Catholic Univ Amer, Greenbelt, MD 20771 USA. NR 72 TC 43 Z9 44 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 JUL 10 PY 2007 VL 663 IS 2 BP 1369 EP 1385 DI 10.1086/518683 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500059 ER PT J AU Cook, JC Desch, SJ Roush, TL Trujillo, CA Geballe, TR AF Cook, Jason C. Desch, Steven J. Roush, Ted L. Trujillo, Chadwick A. Geballe, T. R. TI Near-infrared spectroscopy of Charon: Possible evidence for cryovolcanism on Kuiper Belt objects SO ASTROPHYSICAL JOURNAL LA English DT Review DE comets : general; infrared : general; Kuiper Belt; planets and satellites : individual (Charon) ID OUTER SOLAR-SYSTEM; HUBBLE-SPACE-TELESCOPE; CRYSTALLINE WATER ICE; STELLAR OCCULTATION; 2003 EL61; H2O ICE; PLANETOLOGICAL APPLICATIONS; INDUCED AMORPHIZATION; ABSORPTION-SPECTRUM; PHYSICAL-PROPERTIES AB We present the first reported adaptive optics spectra of Charon in the H and K bands, which examine the anti-Pluto and sub-Pluto hemispheres. The ice temperature is estimated at 40-50 K, based on the 1.65 mu m feature of crystalline water ice. We obtain the most accurate profiles of the 2.21 mu m feature and confirm that the feature is due to hydrated ammonia. We attribute hemispheric differences in the feature's profile to different hydration states. We calculate the rate at which crystalline water ice is amorphized by solar UV/visible radiation, finding that at the depths probed by H and K observations (approximate to 350 mu m), the e-folding time to amorphize ice is (3-5) x 10(4) yr. This implies Charon's ice crystallized from a melt, or has been heated to greater than or similar to 90 K, during the last similar to 10(5) yr. The extent of the crystalline water ice and the short timescales involved argue that surface renewal is necessary, a conclusion reinforced by the presence of ammonia hydrates. We investigate possible mechanisms for surface renewal and conclude that cryovolcanism is the most likely. C1 Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Gemini Observ, Hilo, HI 96720 USA. RP Cook, JC (reprint author), Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. EM jason.cook3@asu.edu NR 111 TC 72 Z9 72 U1 2 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2007 VL 663 IS 2 BP 1406 EP 1419 DI 10.1086/518222 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PR UT WOS:000248001500061 ER PT J AU Glikman, E Djorgovski, SG Stern, D Bogosavljevic, M Mahabal, A AF Glikman, Eilat Djorgovski, S. G. Stern, Daniel Bogosavljevic, Milan Mahabal, Ashish TI Discovery of two spectroscopically peculiar, low-luminosity quasars at z similar to 4 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; quasars : emission lines; quasars : general ID DIGITAL SKY SURVEY; BLACK-HOLE MASSES; ACTIVE GALAXIES; STELLAR OBJECTS; ULTRAVIOLET; EVOLUTION; SPECTRA; MODEL; GOODS; FIELD AB We report the discovery of two low-luminosity quasars at z similar to 4, both of which show prominent N iv] lambda 1486 emission. This line is extremely rare in quasar spectra at any redshift; detecting it in two of a sample of 23 objects (i.e., similar to 9% of the sample) is intriguing and is likely due to the low-luminosity, high-redshift quasar sample we are studying. This is still a poorly explored regime, where contributions from associated, early starbursts may be significant. One interpretation of this line posits photoionization by very massive young stars. Seeing N iv] lambda 1486 emission in a high-redshift quasar may thus be understood in the context of coformation and early coevolution of galaxies and their supermassive black holes. Alternatively, we may be seeing a phenomenon related to the early evolution of quasar broad emission line regions. The nondetection (and possibly even broad absorption) of N v lambda 1240 line in the spectrum of one of these quasars may support that interpretation. These two objects may signal a new faint quasar population or an early AGN evolutionary stage at high redshifts. C1 CALTECH, Dept Astron, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Glikman, E (reprint author), CALTECH, Dept Astron, Pasadena, CA 91125 USA. EM eilatg@astro.caltech.edu; george@astro.caltech.edu; stern@thisvi.jpl.nasa.gov; milan@astro.caltech.edu; aam@astro.caltech.edu NR 23 TC 6 Z9 6 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 JUL 10 PY 2007 VL 663 IS 2 BP L73 EP L76 DI 10.1086/520085 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189PV UT WOS:000248001900006 ER PT J AU Hansell, RA Ou, SC Liou, KN Roskovensky, JK Tsay, SC Hsu, C Ji, Q AF Hansell, R. A. Ou, S. C. Liou, K. N. Roskovensky, J. K. Tsay, S. C. Hsu, C. Ji, Q. TI Simultaneous detection/separation of mineral dust and cirrus clouds using MODIS thermal infrared window data (vol 34, art no L13802, 2007) SO GEOPHYSICAL RESEARCH LETTERS LA English DT Correction C1 Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. RP Hansell, RA (reprint author), Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. RI Tsay, Si-Chee/J-1147-2014; Hansell, Richard/J-2065-2014 NR 1 TC 2 Z9 2 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 JUL 10 PY 2007 VL 34 IS 13 AR L13802 DI 10.1029/2007GL031035 PG 1 WC Geosciences, Multidisciplinary SC Geology GA 189YG UT WOS:000248024000007 ER PT J AU Robinson, MS Hapke, BW Garvin, JB Skillman, D Bell, JF Ulmer, MP Pieters, CM AF Robinson, M. S. Hapke, B. W. Garvin, J. B. Skillman, D. Bell, J. F. I. I. I. I. Ulmer, M. P. Pieters, C. M. TI High resolution mapping of TiO2 abundances on the Moon using the Hubble Space Telescope SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LUNAR; CALIBRATION; IRON AB [1] Samples of the lunar regolith returned by Apollo astronauts show large variations (0 to > 10 wt%) in TiO2 abundance indicating complex compositional zonation within the lunar mantle. A long held goal of the lunar science community is the accurate determination of TiO2 abundances on the lunar surface through remote sensing methods. To date only limited progress has been made in this area using spacecraft spectral measurements acquired in visible through near-infrared wavelengths. Here we show that variations in the ratios of ultraviolet (UV) to visible (VIS) reflectances in images taken by the Hubble Space Telescope indicate a strong correlation with TiO2 abundances determined from returned samples at the Apollo 17 landing site, and little correlation with the "maturity'' of lunar soils. These new findings imply that UV-VIS observations may lead to an alternate and improved method of remotely mapping TiO2-bearing materials (probably as ilmenite) across the lunar surface and enable more refined studies of lunar crustal composition, surface volcanism, and subsurface magma evolution processes. Additionally, accurate identification and quantification of TiO2 rich deposits serves to guide future human exploration of the Moon. C1 Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Pittsburgh, Dept Geol & Planetary Sci, Pittsburgh, PA 15260 USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. RP Robinson, MS (reprint author), Arizona State Univ, Sch Earth & Space Explorat, Box 871404, Tempe, AZ 85287 USA. EM mrobinson@asu.edu RI Skillman, David/C-8995-2013 NR 14 TC 10 Z9 10 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 JUL 7 PY 2007 VL 34 IS 13 AR L13203 DI 10.1029/2007GL029754 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 187WS UT WOS:000247880400002 ER PT J AU Burlaga, LF F-Vinas, A Wang, C AF Burlaga, L. F. F-Vinas, A. Wang, C. TI Tsallis distributions of magnetic field strength variations in the heliosphere: 5 to 90 AU SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NONEXTENSIVE STATISTICAL-MECHANICS; FULLY-DEVELOPED TURBULENCE; SOLAR-WIND; GENERALIZED STATISTICS; VOYAGER-2 OBSERVATIONS; VELOCITY FLUCTUATION; MICROSCOPIC DYNAMICS; ANOMALOUS DIFFUSION; DISTANT HELIOSPHERE; OUTER HELIOSPHERE AB [1] The Tsallis (q-exponential) distribution function, derived from the entropy principle of nonextensive statistical mechanics, describes fluctuations in the magnetic field strength on many scales throughout the heliosphere. This paper shows that a one-dimensional multifluid magnetohydrodynamic (MHD) model, with Advanced Composition Explorer (ACE) observations at 1 AU as input, predicts Tsallis distributions between 5 and 90 AU on scales from 1 to 128 days. At a scale of 1 day, the radial variation of the entropic index q decreases from q >= 5/ 3 at R <= 50 AU to q <= 5/ 3 at R >= 60 AU, corresponding to a change from a divergent to a convergent second moment of the Tsallis distribution, suggesting the possibility of a "phase transition'' and/or a relaxation effect at approximate to 60 AU. The Tsallis distribution derived from the time series of one-dimensional MHD model is nearly identical to those observed by Voyager 1 at similar to 80 AU over the scales from 1 to 64 days during the year 2000. The Tsallis distribution appears over a wide range of scales and distances despite the complex nonlinear dynamical evolution of the heliospheric magnetic field during 1999/2000. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Chinese Acad Sci, State Key Lab Space Weather, Beijing, Peoples R China. RP Burlaga, LF (reprint author), NASA, Goddard Space Flight Ctr, Code 673, Greenbelt, MD 20771 USA. EM leonard.f.burlaga@nasa.gov; adolfo.vinas@gsfc.nasa.gov; cw@spaceweather.ac.cn NR 54 TC 35 Z9 35 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 7 PY 2007 VL 112 IS A7 AR A07206 DI 10.1029/2006JA012213 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YG UT WOS:000247884600006 ER PT J AU Vasquez, BJ Smith, CW Hamilton, K MacBride, BT Leamon, RJ AF Vasquez, Bernard J. Smith, Charles W. Hamilton, Kathleen MacBride, Benjamin T. Leamon, Robert J. TI Evaluation of the turbulent energy cascade rates from the upper inertial range in the solar wind at 1 AU SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Review ID 3-DIMENSIONAL MAGNETOHYDRODYNAMIC TURBULENCE; INTERPLANETARY ALFVENIC FLUCTUATIONS; THERMAL ELECTRON DISTRIBUTIONS; MEAN MAGNETIC-FIELD; MHD TURBULENCE; DISSIPATION RANGE; RADIAL EVOLUTION; HYDROMAGNETIC TURBULENCE; ANISOTROPIC TURBULENCE; ULYSSES OBSERVATIONS AB [1] We construct a database from ACE spacecraft measurements of solar wind magnetic field fluctuations at 1 AU which resolves similar to 2 decades in frequency at the high end of the inertial range. Using magnetic field measurements outside of magnetic clouds in combination with plasma measurements, we evaluate expressions for the Kolmogorov and Kraichnan cascade rates at 0.01 Hz from magnetic field power spectra and consider both isotropic and cross-field rates. We examine these rates as functions of proton temperature and solar wind speed, comparing them to the expected rate based on the heating of protons at 1 AU. The average Kolmogorov rate is consistently more than a factor of 10 greater than expected. We conclude that the cascade rate cannot be estimated using the Kolmogorov prescription and power spectra. The Kraichnan rate is close to the expected rate and is potentially a good way to estimate the cascade rate. No distinction is found between the isotropic and cross-field rates at 1 AU. However, consideration of the likely dependence of cascade rates with distance from the Sun shows that a distinction should exist at distances closer than 1 AU but not outside 1 AU. Moreover, we find that inside 1 AU, the cross-field Kraichnan prediction can maintain agreement with the expected heating rate whereas the isotropic prediction cannot. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. ADNET Syst Inc, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Vasquez, BJ (reprint author), Univ New Hampshire, Ctr Space Sci, Morse Hall, Durham, NH 03824 USA. EM bernie.vasquez@unh.edu; charles.smith@unh.edu; hamilton@briaxa.sr.unh.edu; btmb@cisunix.unh.edu; leamon@grace.nascom.nasa.gov NR 110 TC 79 Z9 79 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 2007 VL 112 IS A7 AR A07101 DI 10.1029/2007JA012305 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YG UT WOS:000247884600008 ER PT J AU Zong, QG Fu, SY Baker, DN Goldstein, ML Song, P Slavin, JA Fritz, TA Cao, JB Amm, O Frey, H Korth, A Daly, PW Reme, H Pedersen, A AF Zong, Q.-G. Fu, S. Y. Baker, D. N. Goldstein, M. L. Song, P. Slavin, J. A. Fritz, T. A. Cao, J. B. Amm, O. Frey, H. Korth, A. Daly, P. W. Reme, H. Pedersen, A. TI Earthward flowing plasmoid: Structure and its related ionospheric signature SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GEOTAIL OBSERVATIONS; MAGNETIC-FIELD; FLUX ROPES; CLUSTER; SHEET; RECONNECTION; MAGNETOTAIL; EVOLUTION AB [1] An earthward moving plasmoid has been observed on 28 October 2002 by the Cluster spacecraft with simultaneous auroral viewing by the IMAGE satellite. This offers the opportunity to ascertain the optical and the evolutional signatures in the ionosphere of the earthward moving plasmoid. The ionospheric signatures observed in this paper are not substorm-related. Both the ground-based measurements and IMAGE satellite auroral observations show the ionospheric signatures moving to lower latitudes, when the earthward moving plasmoid is observed by the Cluster spacecraft. The intensity of the current in the center of the plasmoid is found to be weaker than that in the adjacent region. Also, the directions of the current in the central part of the plasmoid, different from the background cross-tail current, are more field-aligned. Those facts are consistent with the tail current closes through the substorm-like current wedge, since the cross-tail current is blocked by the plasmoid. On the other hand, the current in the earthward plasmoid may close through the interhemisphere. In this paper we demonstrate that the magnetic structures, plasmoids and flux ropes, will transport flux and energy from the distant tail to the Earth. C1 Univ Massachusetts, Ctr Atmospher Res, Lowell, MA 01854 USA. Finnish Meteorol Inst, Geophys Res Div, F-00101 Helsinki, Finland. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Chinese Acad Sci, State Key Lab Space Weather, Beijing 100080, Peoples R China. Max Planck Inst Sonnensystemforsch, D-37189 Katlenburg Lindau, Germany. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. Peking Univ, Dept Geophys, Beijing 100871, Peoples R China. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Oslo, Dept Phys, N-0316 Oslo, Norway. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. RP Zong, QG (reprint author), Univ Massachusetts, Ctr Atmospher Res, 600 Suffolk St, Lowell, MA 01854 USA. EM quigang_zong@uml.edu RI Goldstein, Melvyn/B-1724-2008; Slavin, James/H-3170-2012; Fu, Suiyan/E-9178-2013; OI Slavin, James/0000-0002-9206-724X; Frey, Harald/0000-0001-8955-3282 NR 22 TC 23 Z9 23 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 7 PY 2007 VL 112 IS A7 AR A07203 DI 10.1029/2006JA012112 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187YG UT WOS:000247884600003 ER PT J AU Johnson, JR Bell, JF Cloutis, E Staid, M Farrand, WH Mccoy, T Rice, M Wang, A Yen, A AF Johnson, J. R. Bell, J. F., III Cloutis, E. Staid, M. Farrand, W. H. McCoy, T. Rice, M. Wang, A. Yen, A. TI Mineralogic constraints on sulfur-rich soils from Pancam spectra at Gusev crater, Mars SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID REFLECTANCE SPECTROSCOPY; QUANTITATIVE-ANALYSIS; MIXTURE ANALYSIS; DISCRIMINATION AB [1] The Mars Exploration Rover (MER) Spirit excavated sulfur-rich soils exhibiting high albedo and relatively white to yellow colors at three main locations on and south of Husband Hill in Gusev crater, Mars. The multispectral visible/near-infrared properties of these disturbed soils revealed by the Pancam stereo color camera vary appreciably over small spatial scales, but exhibit spectral features suggestive of ferric sulfates. Spectral mixture models constrain the mineralogy of these soils to include ferric sulfates in various states of hydration, such as ferricopiapite [Fe2/32+Fe43+(SO4)(6)(OH)(2) center dot 20(H2O)], hydronium jarosite [(H3O)Fe-3(3+) (SO4)(2)(OH)(6)], fibroferrite [Fe3+(SO4)(OH) center dot 5(H2O)], rhomboclase [HFe3+(SO4)(2) center dot 4(H2O)], and paracoquimbite [Fe-2(3+) (SO4)(3) center dot 9(H2O)]. C1 US Geol Survey, Flagstaff, AZ 86001 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Winnipeg, Dept Geog, Winnipeg, MB R3B 2E9, Canada. Space Sci Inst, Boulder, CO 80301 USA. Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. Planetary Sci Inst, Tucson, AZ 85719 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnson, JR (reprint author), US Geol Survey, 2255 N Gemini Dr, Flagstaff, AZ 86001 USA. EM jrjohnson@usgs.gov; jfb8@cornell.edu; e.cloutis@uwinnipeg.ca; staid@psi.edu; farrand@colorado.edu; mccoyt@si.edu; mrice@astro.cornell.edu; alianw@levee.wustl.edu; albert.yen@jpl.nasa.gov RI Johnson, Jeffrey/F-3972-2015 NR 36 TC 49 Z9 49 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 6 PY 2007 VL 34 IS 13 AR L13202 DI 10.1029/2007GL029894 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 187WP UT WOS:000247880100004 ER PT J AU Wen, GY Marshak, A Cahalan, RF Remer, LA Kleidman, RG AF Wen, Guoyong Marshak, Alexander Cahalan, Robert F. Remer, Lorraine A. Kleidman, Richard G. TI 3-D aerosol-cloud radiative interaction observed in collocated MODIS and ASTER images of cumulus cloud fields SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CLEAR-SKY REFLECTANCE; OPTICAL-THICKNESS; WATER CLOUDS; RETRIEVAL; PRODUCTS; SMOKE; ATMOSPHERES; VALIDATION; POLLUTION; RADIANCE AB [1] Three-dimensional (3-D) aerosol-cloud interaction is examined by analyzing two images containing cumulus clouds in biomass-burning regions in Brazil. The research consists of two parts. The first part focuses on identifying 3-D cloud impacts on reflectances for the pixels selected for the MODIS aerosol retrieval based purely on observations. The second part of the research combines the observations with radiative transfer computations to identify key parameters in the 3-D aerosol-cloud interaction. We find that 3-D cloud-induced enhancement depends on the optical properties of nearby clouds as well as on wavelength. The enhancement is too large to be ignored. Associated bias error in one-dimensional (1-D) aerosol optical thickness retrieval ranges from 50 to 140% depending on wavelength and the optical depth of nearby clouds, as well as aerosol optical thickness. We caution the community to be prudent when applying 1-D approximations in computing solar radiation in clear regions adjacent to clouds or when using traditional retrieved aerosol optical thickness in aerosol indirect effect research. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Sytst & Applicat Inc, Lanham, MD USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Wen, GY (reprint author), NASA, Goddard Space Flight Ctr, Code 613-2, Greenbelt, MD 20771 USA. EM wen@climate.gsfc.nasa.gov RI Cahalan, Robert/E-3462-2012; Marshak, Alexander/D-5671-2012 OI Cahalan, Robert/0000-0001-9724-1270; NR 34 TC 100 Z9 101 U1 0 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 6 PY 2007 VL 112 IS D13 AR D13204 DI 10.1029/2006JD008267 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 187XB UT WOS:000247881300005 ER PT J AU Touil, H Hussaini, MY Gotoh, T Rubinstein, R Woodruff, SL AF Touil, H. Hussaini, M. Y. Gotoh, T. Rubinstein, R. Woodruff, S. L. TI Development of stochastic models for turbulence SO NEW JOURNAL OF PHYSICS LA English DT Article ID ISOTROPIC TURBULENCE; EDDY VISCOSITY; SCALE MODEL; SIMULATION; NOISE AB Subgrid scale interactions in forced homogeneous turbulence are decomposed into components correlated and uncorrelated with the resolved velocity field. The correlated part is well known to be equivalent to a spectral eddy viscosity. The mean energy transfer can be predicted even if the uncorrelated remainder is ignored, but statistics pertaining to the fluctuations of the nonlinear term require a model for the remainder, which is found to have a strongly non-Gaussian probability density. Some implications of including these non-Gaussian properties in stochastic models are described. C1 NASA, Langley Res Ctr, Computat Aerosci Branch, Hampton, VA 23665 USA. Florida State Univ, Ctr Adv Power Syst, Tallahassee, FL 32306 USA. Florida State Univ, Dept Computat Sci & Informat Technol, Tallahassee, FL 32306 USA. Nagoya Inst Technol, Dept Computat Phys, Nagoya, Aichi, Japan. RP Rubinstein, R (reprint author), NASA, Langley Res Ctr, Computat Aerosci Branch, Hampton, VA 23665 USA. EM r.rubinstein@nasa.gov NR 26 TC 0 Z9 0 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1367-2630 J9 NEW J PHYS JI New J. Phys. PD JUL 6 PY 2007 VL 9 AR 215 DI 10.1088/1367-2630/9/7/215 PG 11 WC Physics, Multidisciplinary SC Physics GA 188XR UT WOS:000247953100003 ER PT J AU Thomas, PC Armstrong, JW Asmar, SW Burns, JA Denk, T Giese, B Helfenstein, P Iess, L Johnson, TV McEwen, A Nicolaisen, L Porco, C Rappaport, N Richardson, J Somenzi, L Tortora, P Turtle, EP Veverka, J AF Thomas, P. C. Armstrong, J. W. Asmar, S. W. Burns, J. A. Denk, T. Giese, B. Helfenstein, P. Iess, L. Johnson, T. V. McEwen, A. Nicolaisen, L. Porco, C. Rappaport, N. Richardson, J. Somenzi, L. Tortora, P. Turtle, E. P. Veverka, J. TI Hyperion's sponge-like appearance SO NATURE LA English DT Article ID CHAOTIC ROTATION; SMALL SATELLITES; IMPACT; GEOLOGY; ASTEROIDS; DYNAMICS; IAPETUS; IMAGES; PHOEBE; SATURN AB Hyperion is Saturn's largest known irregularly shaped satellite and the only moon observed to undergo chaotic rotation(1-3). Previous work has identified Hyperion's surface as distinct from other small icy objects(4,5) but left the causes unsettled. Here we report high-resolution images that reveal a unique sponge-like appearance at scales of a few kilometres. Mapping shows a high surface density of relatively well-preserved craters two to ten kilometres across. We have also determined Hyperion's size and mass, and calculated the mean density as 544 +/- 50 kg m(-3), which indicates a porosity of > 40 per cent. The high porosity may enhance preservation of craters by minimizing the amount of ejecta produced or retained(6,7), and accordingly may be the crucial factor in crafting this unusual surface. C1 Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Free Univ Berlin, Inst Geol Wissenschaft, D-12249 Berlin, Germany. German Aerosp Ctr, Inst Planetary Res, D-12489 Berlin, Germany. Univ Roma La Sapienza, Dipartimento Ingn Aerosp & Astronaut, I-00184 Rome, Italy. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Space Sci Inst, Boulder, CO 80301 USA. Univ Bologna, DIEM II Fac Ingn, Forli, Italy. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Thomas, PC (reprint author), Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. EM pct2@cornell.edu RI IESS, Luciano/F-4902-2011; Tortora, Paolo/J-6191-2012; Turtle, Elizabeth/K-8673-2012 OI IESS, Luciano/0000-0002-6230-5825; Tortora, Paolo/0000-0001-9259-7673; Turtle, Elizabeth/0000-0003-1423-5751 NR 29 TC 32 Z9 32 U1 2 U2 6 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 5 PY 2007 VL 448 IS 7149 BP 50 EP 53 DI 10.1038/nature05779 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 185OS UT WOS:000247720900034 PM 17611535 ER PT J AU Cruikshank, DP Dalton, JB Ore, CMD Bauer, J Stephan, K Filacchione, G Hendrix, AR Hansen, CJ Coradini, A Cerroni, P Tosi, F Capaccioni, F Jaumann, R Buratti, BJ Clark, RN Brown, RH Nelson, RM McCord, TB Baines, KH Nicholson, PD Sotin, C Meyer, AW Bellucci, G Combes, M Bibring, JP Langevin, Y Sicardy, B Matson, DL Formisano, V Drossart, P Mennella, V AF Cruikshank, D. P. Dalton, J. B. Ore, C. M. Dalle Bauer, J. Stephan, K. Filacchione, G. Hendrix, A. R. Hansen, C. J. Coradini, A. Cerroni, P. Tosi, F. Capaccioni, F. Jaumann, R. Buratti, B. J. Clark, R. N. Brown, R. H. Nelson, R. M. McCord, T. B. Baines, K. H. Nicholson, P. D. Sotin, C. Meyer, A. W. Bellucci, G. Combes, M. Bibring, J.-P. Langevin, Y. Sicardy, B. Matson, D. L. Formisano, V. Drossart, P. Mennella, V. TI Surface composition of Hyperion SO NATURE LA English DT Article ID PHOEBE; THOLINS; IAPETUS; CO2 AB Hyperion, Saturn's eighth largest icy satellite, is a body of irregular shape in a state of chaotic rotation(1,2). The surface is segregated into two distinct units. A spatially dominant high-albedo unit having the strong signature of H2O ice contrasts with a unit that is about a factor of four lower in albedo and is found mostly in the bottoms of cup-like craters. Here we report observations of Hyperion's surface in the ultraviolet and near-infrared spectral regions with two optical remote sensing instruments on the Cassini spacecraft at closest approach during a fly-by on 25 - 26 September 2005. The close fly-by afforded us the opportunity to obtain separate reflectance spectra of the high-and low-albedo surface components. The low-albedo material has spectral similarities and compositional signatures that link it with the surface of Phoebe and a hemisphere-wide superficial coating on Iapetus. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, USR SOFIA, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94043 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. DLR, Inst Planetary Explorat, D-12489 Berlin, Germany. INAF IASF Ist Astrofis Spaziale & Fis Cosmica, I-00133 Rome, Italy. INAF IASF Ist Spazio Interplanetario, I-00133 Rome, Italy. Denver Fed Ctr, USGS, Lakewood, CO 80225 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Space Sci Inst NW, Winthrop, WA USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Nantes, F-44072 Nantes, France. Observ Paris, Dept Rech Spatial, F-95129 Meudon, France. Univ Paris 11, Inst Astrophys Spatial, F-91405 Orsay, France. INAF OAC Osservat Astron Capodimonte, I-80131 Naples, Italy. RP Cruikshank, DP (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. EM Dale.P.Cruikshank@nasa.gov OI Tosi, Federico/0000-0003-4002-2434; Cerroni, Priscilla/0000-0003-0239-2741; Bellucci, Giancarlo/0000-0003-0867-8679; Capaccioni, Fabrizio/0000-0003-1631-4314; Filacchione, Gianrico/0000-0001-9567-0055 NR 18 TC 31 Z9 31 U1 1 U2 9 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 5 PY 2007 VL 448 IS 7149 BP 54 EP 56 DI 10.1038/nature05948 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 185OS UT WOS:000247720900035 PM 17611536 ER PT J AU Hakkinen, S AF Haekkinen, Sirpa TI Upper ocean T-S variations in the Greenland Sea and their association to climatic conditions SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORDIC SEAS; WATER FORMATION; DEEP-WATER; CONVECTION; WINTER; TEMPERATURE; VARIABILITY; CIRCULATION; ICE AB [1] Hydrography from the Nordic seas from 1951 to 2003 was analyzed focusing on the upper ocean conditions during known periods of deep mixing. The analysis used data from NOAA National Oceanographic Data Center and from International Council for the Exploration of the Sea Oceanographic Database. Because of the sparseness of the wintertime data, only summertime data are analyzed, primarily at 200 m, which retains memory of previous winter's effects below summer mixed layer. It is found that the salinity variability in the central Greenland Gyre follows closely the sea level pressure (SLP) fluctuations found along the Greenland Coast, e.g., at Angmagssalik. Corresponding large-scale SLP field resembles North Atlantic Oscillation (NAO) in its negative index phase. The dissimilarity between the central gyre salinity fluctuations and the incoming Atlantic water salinity fluctuations suggests that mixing with other water masses (Arctic origin waters and recirculating Atlantic waters) present in the central gyre is important in modifying the incoming Atlantic water salinity at interannual timescales. However, the largest freshwater addition to the Atlantic waters takes place in the Norwegian Sea or even further upstream in the North Atlantic. The variability of this freshwater intake resembles the NAO index on multidecadal timescales. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hakkinen, S (reprint author), NASA, Goddard Space Flight Ctr, Code 614-2, Greenbelt, MD 20771 USA. EM sirpa.hakkinen@nasa.gov RI Hakkinen, Sirpa/E-1461-2012 NR 27 TC 5 Z9 5 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUL 4 PY 2007 VL 112 IS C7 AR C07004 DI 10.1029/2006JC003498 PG 9 WC Oceanography SC Oceanography GA 187XJ UT WOS:000247882200002 ER PT J AU Safrankova, J Nemecek, Z Prech, L Simunek, J Sibeck, D Sauvaud, JA AF Safrankova, J. Nemecek, Z. Prech, L. Simunek, J. Sibeck, D. Sauvaud, J.-A. TI Variations of the flank LLBL thickness as response to the solar wind dynamic pressure and IMF orientation SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID LATITUDE BOUNDARY-LAYER; INTERPLANETARY MAGNETIC-FIELD; KELVIN-HELMHOLTZ INSTABILITY; DAYSIDE MAGNETOPAUSE; MAGNETOSPHERIC BOUNDARY; EARTHS MAGNETOSPHERE; MHD SIMULATION; RECONNECTION; PLASMA; SHEAR AB [1] Several mechanisms have been discussed as candidates for a formation of the low-latitude boundary layer (LLBL) magnetic reconnection between the magnetospheric and magnetosheath magnetic fields, impulsive penetration of magnetosheath plasma, and viscous/diffusive mixing of plasma populations at the magnetopause. The observed fluctuations of plasma parameters inside the LLBL are attributed either to transient nature of the phenomena forming the layer or to sweeping of deformations of the magnetopause or an inner edge of the LLBL surface along the spacecraft. We are using the Interball-1/Magion-4 satellite pair separated by several thousands of kilometers in order to distinguish between spatial and temporal changes of the LLBL plasma population. Observations of LLBL crossings invoked by sudden changes of upstream conditions show that even during a strongly northward interplanetary magnetic field (IMF), the LLBL is relatively thin and follows the compression of the magnetopause induced by changes of the solar wind dynamic pressure. The thickness of the LLBL increases significantly (from a small fraction of R-E to more than 1.4 R-E) with increase in upstream density and IMF B-Y component. Our results indicate that the dusk LLBL is supplied by high-latitude reconnection in the Southern (Northern) Hemisphere, when IMF B-Y is negative (positive) and lies on open field lines. The change of IMF B-Y direction leads to brief presence of LLBL plasma outside the magnetopause on magnetosheath field lines. Fluctuations of plasma parameters and magnetic field implicate the presence of surface waves on the inner edge of the LLBL, but no waves were observed on the magnetopause. C1 Charles Univ Prague, Fac Math & Phys, CR-18000 Prague 8, Czech Republic. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Acad Sci Czech Republic, Inst Atmospher Phys, Prague 14131 4, Czech Republic. RP Safrankova, J (reprint author), Charles Univ Prague, Fac Math & Phys, V Holesovickach 2, CR-18000 Prague 8, Czech Republic. EM jana.safrankova@mff.cuni.cz RI Sibeck, David/D-4424-2012; Simunek, Jiri/H-8139-2014 NR 47 TC 16 Z9 16 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 4 PY 2007 VL 112 IS A7 AR A07201 DI 10.1029/2006JA011889 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 187XY UT WOS:000247883800001 ER PT J AU Woodard, SE Taylor, BD AF Woodard, Stanley E. Taylor, Bryant D. TI A wireless fluid-level measurement technique SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article DE magnetic field response sensor; fluid-level sensor; wireless; cryogenic ID SENSOR AB This paper presents the application of a recently developed wireless measurement acquisition system to fluid-level measurement that alleviates many shortcomings of fluid-level measurement methods currently being used, including limited applicability of any one fluid-level sensor design; necessity for power to be supplied to each sensor and for the measurement to be extracted from each sensor via a physical connection to the sensor and needing a data channel and signal conditioning electronics be dedicated to each sensor. Use of wires results in other shortcomings such as logistics needed to add or replace sensors, weight, potential for electrical arcing and wire degradations. The fluid-level sensor design is a simple passive inductor-capacitor circuit that is not subject to mechanical failure that is possible when float and lever-arm systems are used. Oscillating magnetic fields are used to power the sensor. Once electrically excited, the sensor produces a magnetic field response. The response frequency corresponds to the amount of fluid within the capacitor's electric field. The sensor design can be modified for measuring the level of any fluid or non-gaseous fluid substance that can be stored in a non-conductive reservoir. Methods are presented for using the sensor in caustic, acidic or cryogenic fluids. A method is also presented for calibrating the sensor response with respect to fractional fluid levels for different fluids using only the response when sensor is completely immersed in fluid and with it is not immersed in fluid. Results are presented for measuring the levels of hydrochloric acid, liquid nitrogen, sugar, ground corn, ammonia, bleach, water, salt water, oil, and transmission fluid. Published by Elsevier B.V. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Woodard, SE (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM s.e.woodard@larc.nasa.gov NR 16 TC 20 Z9 20 U1 1 U2 14 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 JUL 4 PY 2007 VL 137 IS 2 BP 268 EP 278 DI 10.1016/j.sna.2007.03.031 PG 11 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 189KK UT WOS:000247987600012 ER PT J AU Wilson, TL Lodhi, MAK Diaz, AB AF Wilson, Thomas L. Lodhi, M. A. K. Diaz, Abel B. TI Effect of thermospheric neutral density upon inner trapped-belt proton flux SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS LA English DT Article ID SOLAR EUV PROXY; UPPER ATMOSPHERE; MODEL; MODULATION; DECREASE; E-10.7 AB We wish to point out that a secular change in the Earth's atmospheric neutral density alters charged-particle lifetime in the inner trapped radiation belts, in addition to the changes recently reported as produced by greenhouse gases. Heretofore, changes in neutral density have been of interest primarily because of their effect on the orbital drag of satellites. We extend this to include the orbital lifetime of charged particles in the lower radiation belts. It is known that the charged-belt population is coupled to the neutral density of the atmosphere through changes induced by solar activity, an effect produced by multiple scattering off neutral and ionized atoms along with ionization loss in the thermosphere where charged and neutral populations interact. It will be shown here that trapped-belt flux J is bivariant in energy E and thermospheric neutral density rho, as J( E, rho). One can conclude that proton lifetimes in these belts are also directly affected by secular changes in the neutral species populating the Earth's thermosphere. This result is a consequence of an intrinsic property of charged-particle flux, that flux is not merely a function of E but is dependent upon density rho when a background of neutrals is present. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Lodhi, M. A. K.; Diaz, Abel B.] Texas Tech Univ, Dept Phys, Lubbock, TX 79409 USA. RP Wilson, TL (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 31 TC 0 Z9 0 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1542-7390 J9 SPACE WEATHER JI Space Weather PD JUL 4 PY 2007 VL 5 IS 7 AR S07001 DI 10.1029/2006SW000280 PG 6 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 261JI UT WOS:000253074500001 ER PT J AU Oppo, DW Schmidt, GA LeGrande, AN AF Oppo, Delia W. Schmidt, Gavin A. LeGrande, Allegra N. TI Seawater isotope constraints on tropical hydrology during the Holocene SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEA-SURFACE TEMPERATURE; ATLANTIC THERMOHALINE CIRCULATION; LAST GLACIAL MAXIMUM; ASIAN MONSOON; PACIFIC; OCEAN; CLIMATE; FORAMINIFERA; MIDHOLOCENE; EPOCH AB [1] Paleoceanographic data from the low latitude Pacific Ocean provides evidence of changes in the freshwater budget and redistribution of freshwater within the basin during the Holocene. Reconstructed Holocene seawater delta O-18 changes compare favorably to differences predicted between climate simulations for the middle Holocene (MH) and for the pre-Industrial late Holocene (LH). The model simulations demonstrate that changes in the tropical hydrologic cycle affect the relationship between delta(18)Osw and surface salinity, and allow, for the first time, quantitative estimates of western Pacific salinity change during the Holocene. The simulations suggest that during the MH, the mean salinity of the Pacific was higher because less water vapor was transported from the Atlantic Ocean and more was transported to the Indian Ocean. The salinity of the western Pacific was enhanced further due both to the greater advection of salt to the region by ocean currents and to an increase in continental precipitation at the expense of maritime precipitation, the latter a consequence of the stronger Asian summer monsoon. C1 Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA. Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. RP Oppo, DW (reprint author), Woods Hole Oceanog Inst, Dept Geol & Geophys, 360 Woods Hole Rd,MS 23, Woods Hole, MA 02543 USA. EM doppo@whoi.edu RI Schmidt, Gavin/D-4427-2012; LeGrande, Allegra/D-8920-2012 OI Schmidt, Gavin/0000-0002-2258-0486; LeGrande, Allegra/0000-0002-5295-0062 NR 35 TC 29 Z9 29 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 JUL 3 PY 2007 VL 34 IS 13 AR L13701 DI 10.1029/2007GL030017 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 187WL UT WOS:000247879700003 ER PT J AU Kobayashi, S Ito, S Tanelli, S Oguchi, T Im, E AF Kobayashi, Satoru Ito, Shigeo Tanelli, Simone Oguchi, Tomohiro Im, Eastwood TI A time-dependent multiple scattering theory for a pulsed radar with a finite beam width SO RADIO SCIENCE LA English DT Article ID DEPOLARIZED BACKSCATTERING ENHANCEMENT; RADIATIVE-TRANSFER EQUATION; SPHERICAL SCATTERERS; MILLIMETER-WAVE; RAIN; HYDROMETEORS; POLARIZATION; ATTENUATION; LADDER AB [1] Multiple scattering returns from spherical water particles of uniform diameter are studied for pulsed radar operation. The Gaussian transverse beam-profile and the rectangular pulse-duration are taken into account. A second-order analytical solution is derived for a single layer structure, based on the time-dependent radiative transfer theory. The method itself can be extended to higher-order scatterings in a multiple layered structure with general drop size distributions. The calculation results show that the effect of second-order scattering becomes larger, as the footprint radius, range, and range resolution, which are normalized by the mean free path, increase. C1 Appl Mat Inc, Santa Clara, CA 95054 USA. Kanto Gakuin Univ, Dept Elect & Elect Engn, Yokohama, Kanagawa 2368501, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Toyo Univ, Sch Engn, Kawagoe, Saitama 3508585, Japan. RP Kobayashi, S (reprint author), Appl Mat Inc, 3050 Bowers Ave,MS 81517, Santa Clara, CA 95054 USA. EM skobay36@hotmail.com NR 28 TC 6 Z9 6 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD JUL 3 PY 2007 VL 42 IS 4 AR RS4001 DI 10.1029/2006RS003555 PG 14 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 187YW UT WOS:000247886300001 ER PT J AU Picard, YN Twigg, ME Mastro, MA Eddy, CR Henry, RL Holm, RT Neudeck, PG Trunek, AJ Powell, JA AF Picard, Y. N. Twigg, M. E. Mastro, M. A. Eddy, C. R., Jr. Henry, R. L. Holm, R. T. Neudeck, P. G. Trunek, A. J. Powell, J. A. TI Threading dislocation behavior in AlN nucleation layers for GaN growth on 4H-SiC SO APPLIED PHYSICS LETTERS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; MORPHOLOGY; EVOLUTION; EPITAXY; MESAS; SURFACES AB Threading dislocations in thin (< 200 nm) AlN nucleation layers (NLs) grown by metal-organic chemical vapor deposition on top of 4H-SiC on-axis mesas with atomic-scale steps were analyzed by transmission electron microscopy. The AlN NL controlled threading dislocations in an overlying similar to 2 mu m GaN layer through two identified mechanisms: threading half-loop formation and dislocation bending at V-shaped pits. Threading dislocations in the AlN film could be traced directly to bilayer 4H-SiC steps at the substrate/film interface. These observations reveal several approaches to extended defect reduction in GaN films grown on 4H-SiC. (C) 2007 American Institute of Physics. C1 USN, Res Lab, Elect Sci & Technol Div, Washington, DC 20375 USA. NASA Glenn Res Ctr, Cleveland, OH 44135 USA. OAI, Cleveland, OH 44135 USA. Sest Inc, Cleveland, OH 44135 USA. RP Picard, YN (reprint author), USN, Res Lab, Elect Sci & Technol Div, Washington, DC 20375 USA. EM yoosuf.picard@nrl.navy.mil OI Picard, Yoosuf/0000-0002-2853-5213 NR 22 TC 7 Z9 7 U1 6 U2 17 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 2 PY 2007 VL 91 IS 1 AR 014101 DI 10.1063/1.2754638 PG 3 WC Physics, Applied SC Physics GA 187AM UT WOS:000247819700084 ER PT J AU Wang, DH Minnis, P Charlock, TP Zhou, DK Rose, FG Smith, WL Smith, WL Nguyen, L AF Wang Donghai Minnis, P. Charlock, T. P. Zhou, D. K. Rose, F. G. Smith, W. L. Smith, W. L., Jr. Nguyen, L. TI Real-time mesoscale forecast support during the CLAMS field campaign SO ADVANCES IN ATMOSPHERIC SCIENCES LA English DT Article DE CLAMS field campaign; mesoscale numerical weather prediction; forecast support ID PREDICTION SYSTEM ARPS; NONHYDROSTATIC ATMOSPHERIC SIMULATION; NUMERICAL WEATHER PREDICTION; MODEL AB This paper reports the use of a specialized, mesoscale, numerical weather prediction (NWP) system and a satellite imaging and prediction system that were set up to support the CLAMS (Chesapeake Lighthouse and Aircraft Measurements for Satellites) field campaign during the summer of 2001. The primary objective of CLAMS was to validate satellite-based retrievals of aerosol properties and vertical profiles of the radiative flux, temperature and water vapor. Six research aircraft were deployed to make detailed coincident measurements of the atmosphere and ocean surface with the research satellites that orbited overhead. The mesoscale weather modeling system runs in real-time to provide high spatial and temporal resolution for forecasts that are delivered via the World Wide Web along with a variety of satellite imagery and satellite location predictions. This system is a multi-purpose modeling system capable of both data analysis/assimilation and multi-scale NWP ranging from cloud-scale to larger than regional scale. This is a three-dimensional, nonhydrostatic compressible model in a terrain-following coordinate. The model employs advanced numerical techniques and contains detailed interactive physical processes. The utility of the forecasting system is illustrated throughout the discussion on the impact of the surface-wind forecast on BRDF (Bidirectional Reflectance Distribution Function) and the description of the cloud/moisture forecast versus the aircraft measurement. C1 Chinese Acad Meteorol Sci, State Key Lab Severe Weather, Beijing 100081, Peoples R China. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Analyt Serv & Mat Inc, Hampton, VA 23666 USA. RP Wang, DH (reprint author), Chinese Acad Meteorol Sci, State Key Lab Severe Weather, Beijing 100081, Peoples R China. EM wangdh@cams.cma.gov.cn RI AAS, AAS/C-2949-2014; Minnis, Patrick/G-1902-2010; OI Minnis, Patrick/0000-0002-4733-6148; Rose, Fred G/0000-0003-0769-0772 NR 15 TC 0 Z9 1 U1 0 U2 2 PU SCIENCE CHINA PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 0256-1530 J9 ADV ATMOS SCI JI Adv. Atmos. Sci. PD JUL PY 2007 VL 24 IS 4 BP 599 EP 605 DI 10.1007/s00376-007-0599-3 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 191XE UT WOS:000248164500006 ER PT J AU Gupta, KK Bach, C AF Gupta, K. K. Bach, C. TI Computational fluid dynamics-based aeroservoelastic analysis with Hyper-X applications SO AIAA JOURNAL 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 ANALYSIS CAPABILITY AB A finite element computational fluids dynamics-based aeroservoelastic analysis methodology is presented in this paper, in which both structural and fluids discretization are achieved by the finite element method, and their interaction is modeled by the transpiration boundary condition technique. In the fluids discipline either inviscid or viscous flow may be accounted for, usually employing unstructured grids. A description of a novel viscous How solver employing unstructured grids is given in detail. Provisions are made for digital as well as analog controllers. These new aeroservoelastic analysis techniques are next applied for the solution of a number of example problems including the novel Hyper-X launch vehicle. Experimental and actual flight test data are also compared with analysis results that signify to the efficacy and accuracy of the newly developed solution procedures. C1 NASA, Dryden Flight Res Ctr, Res Engn Directorate, Edwards AFB, CA 93523 USA. Analyt Serv & Mat Inc, Edwards AFB, CA 93523 USA. RP Gupta, KK (reprint author), NASA, Dryden Flight Res Ctr, Res Engn Directorate, Edwards AFB, CA 93523 USA. NR 25 TC 6 Z9 7 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD JUL PY 2007 VL 45 IS 7 BP 1459 EP 1471 DI 10.2514/1.21992 PG 13 WC Engineering, Aerospace SC Engineering GA 190QW UT WOS:000248075000003 ER PT J AU Payne, MWC Williams, DR Trudel, G AF Payne, Michael W. C. Williams, David R. Trudel, Guy TI Space flight rehabilitation SO AMERICAN JOURNAL OF PHYSICAL MEDICINE & REHABILITATION LA English DT Review DE space flight; rehabilitation; weightlessness; disability ID SHORT-DURATION SPACEFLIGHT; POSTSPACEFLIGHT ORTHOSTATIC HYPOTENSION; LONG-TERM SPACEFLIGHT; BED REST; SKELETAL-MUSCLE; SIMULATED MICROGRAVITY; MECHANICAL-PROPERTIES; RESISTANCE EXERCISE; WEIGHT-BEARING; KNEE EXTENSOR AB The weightless environment of space imposes specific physiologic adaptations on healthy astronauts. On return to Earth, these adaptations manifest as physical impairments that necessitate a period of rehabilitation. Physiologic changes result from unloading in microgravity and highly correlate with those seen in relatively immobile terrestrial patient populations such as spinal cord, geriatric, or deconditioned bed-rest patients. Major postflight impairments requiring rehabilitation intervention include orthostatic intolerance, bone demineralization, muscular atrophy, and neurovestibular symptoms. Space agencies are preparing for extended-duration missions, including colonization of the moon and interplanetary exploration of Mars. These longer-duration flights will result in more severe and more prolonged disability, potentially beyond the point of safe return to Earth. This paper will review and discuss existing space rehabilitation plans for major postflight impairments. Evidence-based rehabilitation interventions are imperative not only to facilitate return to Earth but also to extend the safe duration of exposure to a physiologically hostile microgravity environment. C1 Univ Ottawa, Rehabil Ctr, Div PM&R, Ottawa, ON K1H 8M2, Canada. NASA, Johnson Space Ctr, Houston, TX USA. RP Payne, MWC (reprint author), Univ Ottawa, Rehabil Ctr, Div PM&R, 505 Smyth Rd,Room 1200, Ottawa, ON K1H 8M2, Canada. NR 88 TC 10 Z9 13 U1 0 U2 14 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0894-9115 J9 AM J PHYS MED REHAB JI Am. J. Phys. Med. Rehabil. PD JUL PY 2007 VL 86 IS 7 BP 583 EP 591 DI 10.1097/PHM.0b013e31802b8d09 PG 9 WC Rehabilitation; Sport Sciences SC Rehabilitation; Sport Sciences GA 181OE UT WOS:000247445200009 PM 17167347 ER PT J AU Uchida, H Righter, K Lavina, B Nowell, MM Wright, SI Downs, RT Yang, HX AF Uchida, Hinako Righter, Kevin Lavina, Barbara Nowell, Matthew M. Wright, Stuart I. Downs, Robert T. Yang, Hexiong TI Investigation of synthetic Mg1.3V1.7O4 spinel with MgO inclusions: Case study of a spinel with an apparently occupied interstitial site SO AMERICAN MINERALOGIST LA English DT Article DE spinel; crystal chemistry; XRD; inclusion; periclase; electron backscatter diffraction ID X-RAY; DEFECT STRUCTURE; VACANCY DEFECTS; VANADIUM; FE1-XO; WUSTITE; CATION; NONSTOICHIOMETRY; LIMN2O4-DELTA; DIFFRACTION AB A magnesium vanadate spinel crystal, ideally MgV2O4, synthesized at I bar, 1200 degrees C and equilibrated under FMQ + 1.3 logf(O2), condition, was investigated using single-crystal X-ray diffraction, electron microprobe, and electron backscatter diffraction (EBSD). The initial X-ray structure refinements gave tetrahedral and octahedral site occupancies of Wg(0.966)square(0.034)) and (M)(V0.73+V0.1094+Mg0.180), respectively, along with the presence of 0.053 apfu Mg at an interstitial octahedral site (16c). Back-scattered electron (BSE) images and electron microprobe analyses revealed the existence of an Mg-rich phase in the spinel matrix, which was too small (<= 3 pm) for an accurate chemical determination. The EBSD analysis combined with X-ray energy dispersive spectroscopy (XEDS) suggested that the Mg-rich inclusions are periclase oriented coherently with the spine] matrix. The final structure refinements were optimized by subtracting the X-ray intensity contributions (similar to 9%) of periclase reflections, which eliminated the interstitial Mg, yielding a structural formula for spinel Mg-T(M)(V1.3163+V0.3164+Mg0.316)O-4. This Study provides insight into possible origins of refined interstitial cations reported in the literature for spinel, and points to the difficulty of using only X-ray diffraction data to distinguish a spinel with interstitial cations from one with coherently oriented MgO inclusions. C1 Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Nevada, High Pressure Sci & Engn Ctr, Las Vegas, NV 89154 USA. Univ Chicago, GSECARS, Chicago, IL 60637 USA. EDAX TSL, Draper, UT 84020 USA. RP Uchida, H (reprint author), Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA. EM uchidah@email.arizona.edu RI Lavina, Barbara/A-1015-2010 OI Lavina, Barbara/0000-0002-8556-7916 NR 45 TC 4 Z9 4 U1 1 U2 7 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD JUL PY 2007 VL 92 IS 7 BP 1031 EP 1037 DI 10.2138/am.2007.2445 PG 7 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 188AM UT WOS:000247890700006 ER PT J AU Karner, JM Papike, JJ Shearer, CK Mckay, G Le, L Burger, P AF Karner, J. M. Papike, J. J. Shearer, C. K. Mckay, G. Le, L. Burger, P. TI Valence state partitioning of Cr and V between pyroxene-melt: Estimates of oxygen fugacity for martian basalt QUE 94201 SO AMERICAN MINERALOGIST LA English DT Article DE martian meteorites; Vanadium; pyroxene; oxygen fugacity; chromium ID COMPARATIVE PLANETARY MINERALOGY; UPPER-MANTLE; OLIVINE; VANADIUM; MARS; OXYBAROMETER; ELEMENT; LIQUID; SPINEL; EARTH AB Based on the partitioning of Cr and V between pigeonite cores and bulk composition, we estimate that martian basalt QUE 94201 crystallized at an f(O2) between IW+0.2 and IW+0.9. These estimates are based on calibration curves for D-cr, D-V, and D-cr/D-V (pyroxene/melt) derived from experimental charges that were synthesized at f(O2) conditions of IW-1, IW, and IW+1. We believe our f(O2) estimate is robust because (1) the f(O2) is measured in the earliest crystallizing pyroxenes; (2) the calibration curves are based on the same bulk composition as the natural sample; and (3) that bulk composition represents a melt from the martian mantle, so an accurate D-Cr and D-V are measured. Presently, the two best candidates for martian melts, Y 980459 and QUE 94201, indicate an f(O2) of IW to IW+1 for the upper martian mantle. C1 Univ New Mexico, Dept Earth & Planetary Sci, Astromat Inst, Albuquerque, NM 87131 USA. NASA, JSC, Mail Code ST, Houston, TX 77058 USA. ESC Grp, Houston, TX 77058 USA. RP Karner, JM (reprint author), Univ New Mexico, Dept Earth & Planetary Sci, Astromat Inst, Albuquerque, NM 87131 USA. EM jkamer@unm.edu NR 15 TC 26 Z9 26 U1 1 U2 9 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD JUL PY 2007 VL 92 IS 7 BP 1238 EP 1241 DI 10.2138/am-2007.2607 PG 4 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 188AM UT WOS:000247890700029 ER PT J AU Adams, CA Murdoch, JL Consiglio, MC Williams, DM AF Adams, Catherine A. Murdoch, Jennifer L. Consiglio, Maria C. Williams, Daniel M. TI Incorporating data link messaging into a multi-function display to support the Small Aircraft Transportation System (SATS) and the self-senaration of general aviation aircraft SO APPLIED ERGONOMICS LA English DT Article; Proceedings Paper CT International Workshop on Flightdeck of the Future CY OCT 06, 2004 CL Univ Nottingham, Nottingham, ENGLAND SP Flightdeck & Air Traff Control Collaborat Evaluat Project HO Univ Nottingham DE Small Aircraft Transportation System; SATS higher volume operations; MFD and SATS; data link and general aviation; data link messaging AB One objective of the Small Aircraft Transportation System (SATS) Project is to increase the capacity and utilization of small non-towered, non-radar equipped airports by transferring traffic management activities to an automated system and separation responsibilities to general aviation (GA) pilots. This paper describes the development of a research multi-function display (MFD) to support the interaction between pilots and an automated Airport Management Module (AMM). Preliminary results of simulation and flight tests indicate that adding the responsibility of monitoring other traffic for self-separation does not increase pilots' subjective workload levels. Pilots preferred using the enhanced MFD to execute flight procedures, reporting improved situation awareness (SA) over conventional instrument flight rules (IFR) procedures. (C) 2007 Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Res & Technol Directorate, Hampton, VA 23665 USA. RP Adams, CA (reprint author), NASA, Langley Res Ctr, Res & Technol Directorate, Hampton, VA 23665 USA. EM Catherine.A.Adams@nasa.gov NR 9 TC 2 Z9 2 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0003-6870 J9 APPL ERGON JI Appl. Ergon. PD JUL PY 2007 VL 38 IS 4 BP 465 EP 471 DI 10.1016/j.apergo.2007.01.009 PG 7 WC Engineering, Industrial; Ergonomics; Psychology, Applied SC Engineering; Psychology GA 185LX UT WOS:000247713600008 PM 17512491 ER PT J AU Madore, BF de Paz, AG Pevunova, O Thompson, I AF Madore, Barry F. Gil de Paz, Armando Pevunova, Olga Thompson, Ian TI The curious case of NGC 6908 SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : interactions; galaxies : structure ID GALAXIES AB The object NGC 6908 was once thought to simply be a surface brightness enhancement in the eastern spiral arm of the nearby spiral galaxy NGC 6907. Based on an examination of near-infrared imaging, the object is shown to in fact be a lenticular S0(6/7) galaxy hidden in the optical glare of the disk and spiral structure of the larger galaxy. New radial velocities of NGC 6908 [3060 +/- 16 km s(-1) (emission); 3113 +/- 73 km s(-1) (absorption)] have been obtained at the Baade 6.5 m and the du Pont 2.5 m telescopes at Las Campanas, Chile, placing NGC 6908 at the same expansion velocity distance as NGC 6907 (3190 +/- 5 km s(-1)), eliminating the possibility of a purely chance line-of- sight coincidence. The once-enigmatic asymmetries in the disk and outer spiral structure of NGC 6907 are now explained as being due to an advanced merger event. Newly discovered tails and debris in the outer reaches of this galaxy further support the merger scenario for this system. This pair of galaxies is a rather striking example of two objects discovered over 100 years ago, whose true nature was lost until modern detectors operating at infrared wavelengths gave us a new (high-contrast) look. Other examples of embedded merger remnants may also reveal themselves in the growing samples of near-infrared imaging of nearby galaxies, and a pilot study does reveal several other promising candidates for follow-up observations. C1 Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. CALTECH, NASA, IPAC Extragalact Database, Pasadena, CA 91125 USA. Univ Complutense, Dept Astrofis, E-28040 Madrid, Spain. RP Madore, BF (reprint author), Observ Carnegie Inst Washington, 813 Santa Barbara St, Pasadena, CA 91101 USA. EM barry@ociw.edu; agpaz@astrax.fis.ucm.es; olga@ipac.caltech.edu; ian@ociw.edu RI Gil de Paz, Armando/J-2874-2016 OI Gil de Paz, Armando/0000-0001-6150-2854 NR 16 TC 2 Z9 2 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 2007 VL 134 IS 1 BP 314 EP 320 DI 10.1086/518557 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 183RS UT WOS:000247590500029 ER PT J AU Makarov, VV Murphy, DW AF Makarov, V. V. Murphy, D. W. TI The local stellar velocity field via vector spherical harmonics SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; Galaxy : kinematics and dynamics ID PROPER MOTION PROGRAM; GALACTIC WARP; KINEMATICS; HIPPARCOS; STARS; CATALOG; CONSTANTS; OORT AB We analyze the local field of stellar tangential velocities for a sample of 42,339 nonbinary Hipparcos stars with accurate parallaxes, using a vector spherical harmonic formalism. We derive simple relations between the parameters of the classical linear model (Ogorodnikov-Milne) of the local systemic field and low-degree terms of the general vector harmonic decomposition. Taking advantage of these relationships, we determine the solar velocity with respect to the local stars of (V-X, V-Y, V-Z) (10.5; 18.5; 7.3) +/- 0.1 km s(-1) not corrected for the asymmetric drift with respect to the local standard of rest. If only stars more distant than 100 pc are considered, the peculiar solar motion is (V-X, V-Y, V-Z) (9.9; 15.6; 6.9) +/- 0.2 km s(-1). The adverse effects of harmonic leakage, which occurs between the reflex solar motion represented by the three electric vector harmonics in the velocity space and higher degree harmonics in the proper-motion space, are eliminated in our analysis by direct subtraction of the reflex solar velocity in its tangential components for each star. The Oort parameters determined by a straightforward least-squares adjustment in vector spherical harmonics are A = 14.0 +/- 1.4, B = 13.1 +/- 1.2, K = 1.1 +/- 1.8, and C = 2.9 +/- 1.4 km s(-1) kpc(-1). The physical meaning and the implications of these parameters are discussed in the framework of a general linear model of the velocity field. We find a few statistically significant higher degree harmonic terms that do not correspond to any parameters in the classical linear model. One of them, a third-degree electric harmonic, is tentatively explained as the response to a negative linear gradient of rotation velocity with distance from the Galactic plane, which we estimate at similar to-20 km s(-1) kpc(-1). A similar vertical gradient of rotation velocity has been detected for more distant stars representing the thick disk (z > 1 kpc), but here we surmise its existence in the thin disk at z < 200 pc. The most unexpected and unexplained term within the Ogorodnikov-Milne model is the first-degree magnetic harmonic, representing a rigid rotation of the stellar field about the axis - Y pointing opposite to the direction of rotation. This harmonic comes out with a statistically robust coefficient of 6.2 +/- 0.9 km s(-1) kpc(-1) and is also present in the velocity field of more distant stars. The ensuing upward vertical motion of stars in the general direction of the Galactic center and the downward motion in the anticenter direction are opposite to the vector field expected from the stationary Galactic warp model. C1 CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91105 USA. RP Makarov, VV (reprint author), CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. EM vvm@caltech.edu; david.w.murphy@jpl.nasa.gov OI Makarov, Valeri/0000-0003-2336-7887 NR 26 TC 17 Z9 18 U1 0 U2 4 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 2007 VL 134 IS 1 BP 367 EP 375 DI 10.1086/518242 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 183RS UT WOS:000247590500035 ER PT J AU Mangano, V Holland, ST Malesani, D Troja, E Chincarini, G Zhang, B La Parola, V Brown, PJ Burrows, DN Campana, S Capalbi, M Cusumano, G Della Valle, M Gehrels, N Giommi, P Grupe, D Guidorzi, C Mineo, T Moretti, A Osborne, JP Pandey, SB Perri, M Romano, P Roming, PWA Tagliaferri, G AF Mangano, V. Holland, S. T. Malesani, D. Troja, E. Chincarini, G. Zhang, B. La Parola, V. Brown, P. J. Burrows, D. N. Campana, S. Capalbi, M. Cusumano, G. Della Valle, M. Gehrels, N. Giommi, P. Grupe, D. Guidorzi, C. Mineo, T. Moretti, A. Osborne, J. P. Pandey, S. B. Perri, M. Romano, P. Roming, P. W. A. Tagliaferri, G. TI Swift observations of GRB 060614: an anomalous burst with a well behaved afterglow SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts; X-rays : individuals : GRB 060614 ID GAMMA-RAY BURST; HOLE-FORMING SUPERNOVAE; STAR-FORMATION; PEAK ENERGY; E-P,E-I-E-ISO CORRELATION; BATSE OBSERVATIONS; HOST GALAXIES; JET BREAKS; TELESCOPE; EMISSION AB GRB 060614 is a remarkable gamma-ray burst ( GRB) observed by Swift with puzzling properties, which challenge current progenitor models. In particular, the lack of any bright supernova (SN) down to very strict limits and the vanishing spectral lags during the whole burst are typical of short GRBs, strikingly at odds with the long (102 s) duration of this event. Here we present detailed spectral and temporal analysis of the Swift observations of GRB 060614. We show that the burst presents standard optical, ultraviolet and X-ray afterglows, detected beginning 4 ks after the trigger. An achromatic break is observed simultaneously in the optical and X-ray bands, at a time consistent with the break in the R-band light curve measured by the VLT. The achromatic behaviour and the consistent post-break decay slopes make GRB 060614 one of the best examples of a jet break for a Swift burst. The optical and ultraviolet afterglow light curves have also an earlier break at 29.7 +/- 4.4 ks, marginally consistent with a corresponding break at 36.6 +/- 2.4 ks observed in the X-rays. In the optical, there is strong spectral evolution around this break, suggesting the passage of a break frequency through the optical/ ultraviolet band. The very blue spectrum at early times suggests this may be the injection frequency, as also supported by the trend in the light curves: rising at low frequencies, and decaying at higher energies. The early X-ray light curve ( from 97 to 480 s) is well interpreted as the X-ray counterpart of the burst extended emission. Spectral analysis of the BAT and XRT data in the similar to 80 s overlap time interval show that the peak energy of the burst has decreased to as low as 8 keV at the beginning of the XRT observation. Spectral analysis of following XRT data shows that the peak energy of the burst continues to decrease through the XRT energy band and exits it at about 500 s after the trigger. The average peak energy E(p) of the burst is likely below the BAT energy band (< 24 keV at the 90% confidence level) but larger than 8 keV. The initial group of peaks observed by BAT (similar to 5 s) is however distinctly harder than the rest of the prompt emission, with a peak energy of about 300 keV as measured by Konus Wind. Considering the time-averaged spectral properties, GRB 060614 is consistent with the E(iso) - E(p)(rest), E(gamma) - E(p)(rest), and L(p,iso) - E(p)(rest) correlations. C1 INAF, Ist Astrofis Spaz & Fis Cosm, Sez Palermo, I-90146 Palermo, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. Univ Copenhagen, Niels Bohr Inst, Dark Cosmol Ctr, DK-2100 Copenhagen, Denmark. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Univ Palermo, Dipartimento Sci Fis & Astron, Sez Astron, I-90134 Palermo, Italy. Univ Milan, Dipartimento Fis, I-20126 Milan, Italy. INAF, Osservatorio Astron Brera, I-23807 Merate, LC, Italy. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. ASI Sci Data Ctr, I-00044 Frascati, Italy. INAF, Osservatorio Astrofis Arcetri, I-50125 Florence, Italy. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. RP Mangano, V (reprint author), INAF, Ist Astrofis Spaz & Fis Cosm, Sez Palermo, Via Ugo La Malfa 153, I-90146 Palermo, Italy. EM vanessa@ifc.inaf.it RI Gehrels, Neil/D-2971-2012; OI Mineo, Teresa/0000-0002-4931-8445; giommi, paolo/0000-0002-2265-5003; Cusumano, Giancarlo/0000-0002-8151-1990; moretti, alberto/0000-0002-9770-0315; Della Valle, Massimo/0000-0003-3142-5020; Perri, Matteo/0000-0003-3613-4409; La Parola, Valentina/0000-0002-8087-6488; Tagliaferri, Gianpiero/0000-0003-0121-0723 NR 93 TC 88 Z9 89 U1 0 U2 5 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2007 VL 470 IS 1 BP 105 EP U87 DI 10.1051/0004-6361:20077232 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189GM UT WOS:000247977400013 ER PT J AU Volten, H Munoz, O Hovenier, JW Rietmeijer, FJM Nuth, JA Waters, LBFM van der Zande, WJ AF Volten, H. Munoz, O. Hovenier, J. W. Rietmeijer, F. J. M. Nuth, J. A. Waters, L. B. F. M. van der Zande, W. J. TI Experimental light scattering by fluffy aggregates of magnesiosilica, ferrosilica, and alumina cosmic dust analogs SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE comets : general; dust, extinction; polarization; scattering ID METASTABLE EUTECTIC CONDENSATION; RICH AGB STARS; COMETARY DUST; SOLAR-SYSTEM; CIRCUMSTELLAR ENVELOPES; PROGRA(2) EXPERIMENT; SIZE DISTRIBUTIONS; SOLID CONDENSATION; OPTICAL-PROPERTIES; SILICATE GRAINS AB Context. Fluffy aggregates are generally assumed to be important constituents of circumstellar and interplanetary environments as well as to be present among the solid debris ejected from active comets. Aims. We experimentally study light scattering properties of several fluffy aggregate samples. These cosmic dust analog aggregates are composed of coagulated magnesiosilica grains, ferrosilica grains, and alumina grains. The samples contain aggregates with different porosities. The individual grains have diameters of the order of a few tens of nanometers; the aggregates have diameters up to several micrometers. Methods. The samples were produced in a Condensation Flow Apparatus. Their light scattering properties were measured with the Amsterdam Light Scattering Facility at a wavelength of 632.8 nm. Results. We measured two scattering matrix elements as functions of the scattering angle, namely F-11(theta) ( phase function) and -F-12(theta)/F-11(theta) (degree of linear polarization for incident unpolarized light) for seven different samples of aggregates in random orientations in an aerosol jet. The samples consisted of flu. y aggregates with cosmic dust analog compositions. We provide detailed information about their production and nature. In addition, for four of these samples we measured F-22(theta)/F-11(theta). We covered an angle range of 5 degrees to 174 degrees, in small steps of 1 degrees in the range from 5 degrees to 10 degrees and 170 degrees to 174 degrees and in steps of 5 degrees for the rest of the angle range. Conclusions. The results for the analog samples show an extremely high -F-12(theta)/F-11(theta), with maxima between about 60% to almost 100%. This Rayleigh- like behavior has been demonstrated before for flu. y aggregates and suggests that the small- sized grains in the aggregates are the main cause. Measured results for phase functions are more scarce. The phase functions we measured show shapes that are similar to those of compact micron- sized particles, suggesting that it is the overall size of the aggregates that determines their shape. The modest negative branch of -F-12(theta)/F-11(theta) found for all seven samples seems to be mainly governed by aggregate structure. Thus, the unique combination of accurately measured phase functions and polarization functions over a fine mesh of scattering angles for cosmic dust analog aggregates enables the exploitation of the data as powerful diagnostic tools to constrain the different physical properties of dust in e.g. circumstellar clouds and in comet ejecta. C1 Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. NASA, Goddard Space Flight Ctr, Lab Extraterrestrial Phys, Greenbelt, MD 20771 USA. Radboud Univ nijmegen, Inst Mol & Mat, NL-6500 GL Nijmegen, Netherlands. RP Volten, H (reprint author), Univ Amsterdam, Astron Inst Anton Pannekoek, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. EM hovenier@science.uva.nl RI Nuth, Joseph/E-7085-2012; OI Munoz, Olga/0000-0002-5138-3932 NR 64 TC 30 Z9 30 U1 0 U2 4 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2007 VL 470 IS 1 BP 377 EP 386 DI 10.1051/0004-6361:20066744 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189GM UT WOS:000247977400038 ER PT J AU Buchlin, E Cargill, PJ Bradshaw, SJ Velli, M AF Buchlin, E. Cargill, P. J. Bradshaw, S. J. Velli, M. TI Profiles of heating in turbulent coronal magnetic loops SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE sun : corona; magnetohydrodynamics (MHD); turbulence ID AB-INITIO APPROACH; MAGNETOHYDRODYNAMIC TURBULENCE; SOLAR CORONA; STATISTICAL FLARE; SHELL MODELS; NANOFLARES; TRACE; FIELD; FLOW; MHD AB Context. The location of coronal heating in magnetic loops has been the subject of a long-lasting controversy: does it occur mostly at the loop footpoints, at the top, is it random, or is the average profile uniform? Aims. We try to address this question in model loops with MHD turbulence and a profile of density and/or magnetic field along the loop. Methods. We use the Shell-Atm MHD turbulent heating model described in Buchlin & Velli (2007, ApJ, 662, 701), with a static mass density stratification obtained by the HydRad model (Bradshaw & Mason 2003, A& A, 401, 699). This assumes the absence of any flow or heat conduction subsequent to the dynamic heating. Results. The average profile of heating is quasi-uniform, unless there is an expansion of the flux tube (non-uniform axial magnetic field) or the variation of the kinetic and magnetic diffusion coefficients with temperature is taken into account: in the first case the heating is enhanced at footpoints, whereas in the second case it is enhanced where the dominant diffusion coefficient is enhanced. Conclusions. These simulations shed light on the consequences on heating profiles of the complex interactions between physical effects involved in a non-uniform turbulent coronal loop. C1 Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Space & Atmospher Phys Dept, London SW7 2BW, England. Univ Florence, Dipartimento Astron & Sci Spazio, I-50125 Florence, Italy. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Buchlin, E (reprint author), Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Space & Atmospher Phys Dept, London SW7 2BW, England. EM e.buchlin@imperial.ac.uk OI Buchlin, Eric/0000-0003-4290-1897 NR 33 TC 16 Z9 16 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2007 VL 469 IS 1 BP 347 EP 354 DI 10.1051/0004-6361:20077111 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178ZY UT WOS:000247260300039 ER PT J AU Evans, PA Beardmore, AP Page, KL Tyler, LG Osborne, JP Goad, MR O'Brien, PT Vetere, L Racusin, J Morris, D Burrows, DN Capalbi, M Perri, M Gehrels, N Romano, P AF Evans, P. A. Beardmore, A. P. Page, K. L. Tyler, L. G. Osborne, J. P. Goad, M. R. O'Brien, P. T. Vetere, L. Racusin, J. Morris, D. Burrows, D. N. Capalbi, M. Perri, M. Gehrels, N. Romano, P. TI An online repository of Swift/XRT light curves of gamma-ray bursts SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts; gamma rays : observations; methods : data analysis; catalogs ID AFTERGLOW; TELESCOPE AB Context. Swift data are revolutionising our understanding of Gamma Ray Bursts. Since bursts fade rapidly, it is desirable to create and disseminate accurate light curves rapidly. Aims. To provide the community with an online repository of X-ray light curves obtained with Swift. The light curves should be of the quality expected of published data, but automatically created and updated so as to be self-consistent and rapidly available. Methods. We have produced a suite of programs which automatically generates Swift/XRT light curves of GRBs. Effects of the damage to the CCD, automatic readout-mode switching and pile-up are appropriately handled, and the data are binned with variable bin durations, as necessary for a fading source. Results. The light curve repository website* contains light curves, hardness ratios and deep images for every GRB which Swift's XRT has observed. When new GRBs are detected, light curves are created and updated within minutes of the data arriving at the UK Swift Science Data Centre. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. ESRIN, ASDC, ASI Sci Data Ctr, I-00044 Frascati, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Osserv Astron Brera, INAF, I-23807 Merate, LC, Italy. Univ Milan, I-20126 Milan, Italy. RP Evans, PA (reprint author), Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. EM pae9@star.le.ac.uk RI Racusin, Judith/D-2935-2012; Gehrels, Neil/D-2971-2012 NR 16 TC 295 Z9 295 U1 0 U2 3 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2007 VL 469 IS 1 BP 379 EP 385 DI 10.1051/0004-6361:20077530 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178ZY UT WOS:000247260300042 ER PT J AU Mineo, T Mangano, V Covino, S Cusumano, G La Parola, V Troja, E Roming, P Burrows, DN Campana, S Capalbi, M Chincarini, G Gehrels, N Giommi, P Hill, JE Marshall, F Moretti, A O'Brien, P Page, M Perri, M Romano, P Sbarufatti, B Sato, G Tagliaferri, G AF Mineo, T. Mangano, V. Covino, S. Cusumano, G. La Parola, V. Troja, E. Roming, P. Burrows, D. N. Campana, S. Capalbi, M. Chincarini, G. Gehrels, N. Giommi, P. Hill, J. E. Marshall, F. Moretti, A. O'Brien, P. Page, M. Perri, M. Romano, P. Sbarufatti, B. Sato, G. Tagliaferri, G. TI GRB 050410 and GRB 050412: are they really dark gamma-ray bursts? SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts; X-rays : bursts; X-rays : individuals : GRB 050410; X-rays : individuals : GRB 050412 ID REVERSE SHOCK EMISSION; LIGHT CURVES; AFTERGLOW EMISSION; RADIO AFTERGLOW; DIAGNOSTIC-TOOL; HOST GALAXY; TELESCOPE; BRIGHT; ENERGY; ENERGETICS AB Aims. We present a detailed analysis of the prompt and afterglow emission of GRB 050410 and GRB 050412 detected by Swift for which no optical counterpart was observed. Methods. We analysed data from the prompt emission detected by the Swift BAT and from the early phase of the afterglow obtained by the Swift narrow field instrument XRT. Results. The 15-150 keV energy distribution of the GRB 050410 prompt emission shows a peak energy at 53(-21)(+40) keV. The XRT light curve of this GRB decays as a power law with a slope of alpha = 1.06 +/- 0.04. The spectrum is well reproduced by an absorbed power law with a spectral index Gamma(x) = 2.4 +/- 0.4 and a low energy absorption N(H) = 4(-2)(+3) x 10(21) cm(-2) which is higher than the Galactic value. The 15-150 keV prompt emission in GRB 050412 is modelled with a hard (Gamma = 0.7 +/- 0.2) power law. The XRT light curve follows a broken power law with the first slope alpha(1) = 0.7 +/- 0.4, the break time T(break) = 254(-41)(+79) s and the second slope alpha(2) = 2.8(-0.8)(+0.5) . The spectrum is fitted by a power law with spectral index Gamma(x) = 1.3 +/- 0.2 which is absorbed at low energies by the Galactic column. Conclusions. The GRB 050410 afterglow light curve reveals the expected characteristics of the third component of the canonical Swift light curve. Conversely, a complex phenomenology was detected in the GRB 050412 because of the presence of the very early break. The light curve in this case can be interpreted as being the last peak of the prompt emission. The two bursts present tight upper limits for the optical emission, however, neither of them can be clearly classified as dark. For GRB 050410, the suppression of the optical afterglow could be attributed to a low density interstellar medium surrounding the burst. For GRB 050412, the evaluation of the darkness is more difficult due to the ambiguity in the extrapolation of the X-ray afterglow light curve. C1 INAF, Ist Astrofis Spaziale & Fis Cosm Palermo, I-90146 Palermo, Italy. INAF, Osservatorio Astron Brera, I-23807 Merate, LC, Italy. Penn State Univ, University Pk, PA 16802 USA. ASI, Sci Data Ctr, I-00044 Frascati, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. ASI, Unita Osservaz Universo, I-00198 Rome, Italy. Univ Space Res Assoc, Columbia, MD 21044 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. RP Mineo, T (reprint author), INAF, Ist Astrofis Spaziale & Fis Cosm Palermo, Via Ugo La Malfa 153, I-90146 Palermo, Italy. EM teresa.mineo@ifc.inaf.it RI Gehrels, Neil/D-2971-2012; OI Tagliaferri, Gianpiero/0000-0003-0121-0723; Mineo, Teresa/0000-0002-4931-8445; giommi, paolo/0000-0002-2265-5003; Cusumano, Giancarlo/0000-0002-8151-1990; moretti, alberto/0000-0002-9770-0315; Perri, Matteo/0000-0003-3613-4409; La Parola, Valentina/0000-0002-8087-6488; Sbarufatti, Boris/0000-0001-6620-8347; Covino, Stefano/0000-0001-9078-5507 NR 72 TC 5 Z9 5 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2007 VL 469 IS 2 BP 663 EP 669 DI 10.1051/0004-6361:20066594 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 184VY UT WOS:000247671900022 ER PT J AU Zand, JJMI'T Kuiper, L den Hartog, PR Hermsen, W Corbet, RHD AF Zand, J. J. M. in ' T. Kuiper, L. den Hartog, P. R. Hermsen, W. Corbet, R. H. D. TI A probable accretion-powered X-ray pulsar in IGR J00370+6122 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE X-rays : binaries; X-rays : individuals : IGR J00370+6122; X-rays : individuals : 1RXS J003709.6+612131; X-rays : individuals : 1RXS J003357.9+612645; accretion, accretion disks; stars : neutron ID SAX J2103.5+4545; TIMING-EXPLORER; SOURCE CATALOG; FLARING STATE; XTE J1739-302; NEUTRON-STAR; GX 301-2; TRANSIENT; MASS; DISCOVERY AB Serendipitous and dedicated observations with the Rossi X-ray Timing Explorer ( RXTE) and the International Gamma-Ray Astrophysics Laboratory ( INTEGRAL) were analyzed to study the transient high-mass X-ray binary IGR J00370+6122, in particular to search for an accretion-powered pulsar as companion to the optically identified ( Reig et al. 2005, A&A, 440, 637) B0.5 II-III donor star. Highly variable fluxes were measured in the RXTE data during outbursts of up to 2.2 x 10(-10) erg cm(-2) s(-1) (3-20 keV; averaged over 1 h). During a 1-h time span with RXTE flaring activity was detected with an oscillating signal repeating 7 times. Epoch folding reveals a 346 +/- 6 s period. We propose that this is the period of the putative pulsar. This measurement puts the source in the wind-fed accretion region of the P-orb (= 15.7 d) versus P-pulse "Corbet" diagram. The 3 to 60 keV flare spectrum was modeled with an absorbed power law and the absorption column was found to be 15-20 times larger than the interstellar value and the value obtained for the optical counterpart, suggesting an accretor embedded in the wind of the donor star. C1 SRON Netherlands Inst Space Res, NL-3584 CA Utrecht, Netherlands. Univ Utrecht, Astron Inst, NL-3508 TA Utrecht, Netherlands. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. RP Zand, JJMI'T (reprint author), SRON Netherlands Inst Space Res, Sorbonnelaan 2, NL-3584 CA Utrecht, Netherlands. EM jeanz@sron.nl NR 39 TC 7 Z9 7 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 JUL PY 2007 VL 469 IS 3 BP 1063 EP 1068 DI 10.1051/0004-6361:20077189 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 185WD UT WOS:000247740200027 ER PT J AU Gruszecki, M Murawski, K Solanki, SK Ofman, L AF Gruszecki, M. Murawski, K. Solanki, S. K. Ofman, L. TI Attenuation of Alfven waves in straight and curved coronal slabs SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE magnetohydrodynamics (MHD); Sun : corona; Sun : oscillations ID TRANSVERSE OSCILLATIONS; VERTICAL OSCILLATIONS; NUMERICAL SIMULATIONS; MAGNETOSONIC WAVES; LOOP OSCILLATIONS; SOLAR CORONA; TRACE; PROPAGATION; PARAMETERS; MHD AB Aims. We consider impulsively generated Alfven waves in coronal loops to investigate the role of energy leakage on wave attenuation, which includes lateral leakage, leakage into dense photospheric regions and nonlinear driving of magnetosonic waves. Methods. A coronal loop is modelled either as a straight magnetic slab or as a curved slab of smooth mass density profiles. We perform numerical simulations of 2.5D ideal magnetohydrodynamic equations to determine the signatures of Alfven waves. Results. The numerical results show that lateral leakage of Alfven waves is significant in comparison to leakage into the photospheric regions for realistic corona to photospheric density ratios. Energy leakage is enhanced by curvature of magnetic field lines and for large amplitude Alfven waves for which nonlinear driving of magnetosonic waves is more significant than in the linear regime. C1 Marie Curie Sklodowska Univ, Inst Phys, Grp Astrophys & Grav Theory, PL-20031 Lublin, Poland. Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gruszecki, M (reprint author), Marie Curie Sklodowska Univ, Inst Phys, Grp Astrophys & Grav Theory, Ul Radziszewskiego 10, PL-20031 Lublin, Poland. EM marcingruszecki@wp.pl RI Solanki, Sami/E-2487-2013 OI Solanki, Sami/0000-0002-3418-8449 NR 31 TC 15 Z9 15 U1 0 U2 2 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2007 VL 469 IS 3 BP 1117 EP 1121 DI 10.1051/0004-6361:20066924 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 185WD UT WOS:000247740200033 ER PT J AU Bodewits, D Christian, DJ Torney, M Dryer, M Lisse, CM Dennerl, K Zurbuchen, TH Wolk, SJ Tielens, AGGM Hoekstra, R AF Bodewits, D. Christian, D. J. Torney, M. Dryer, M. Lisse, C. M. Dennerl, K. Zurbuchen, T. H. Wolk, S. J. Tielens, A. G. G. M. Hoekstra, R. TI Spectral analysis of the Chandra comet survey SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE surveys; atomic processes; Sun : solar wind; Sun : coronal mass ejections (CMEs); comets : general ID X-RAY-EMISSION; SELECTIVE ELECTRON-CAPTURE; PERTURBED STATIONARY STATES; CHARGE-EXCHANGE EMISSION; FAR-ULTRAVIOLET EMISSION; SOLAR-WIND COMPOSITION; HELIUM-LIKE IONS; C/1999 S4; MCNAUGHT-HARTLEY; CROSS-SECTIONS AB Aims. We present results of the analysis of cometary X-ray spectra with an extended version of our charge exchange emission model (Bodewits et al. 2006). We have applied this model to the sample of 8 comets thus far observed with the Chandra X-ray observatory and acis spectrometer in the 300 - 1000 eV range. The surveyed comets are C/1999 S4 ( linear), C/1999 T1 (McNaught - Hartley), C/2000 WM1 ( linear), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), C/2001 Q4 (neat), 9P/2005 (Tempel 1) and 73P/2006-B (Schwassmann - Wachmann 3) and the observations include a broad variety of comets, solar wind environments and observational conditions. Methods. The interaction model is based on state selective, velocity dependent charge exchange cross sections and is used to explore how cometary X-ray emission depend on cometary, observational and solar wind characteristics. It is further demonstrated that cometary X-ray spectra mainly reflect the state of the local solar wind. The current sample of Chandra observations was fit using the constrains of the charge exchange model, and relative solar wind abundances were derived from the X-ray spectra. Results. Our analysis showed that spectral differences can be ascribed to different solar wind states, as such identifying comets interacting with ( I) fast, cold wind, (II), slow, warm wind and (III) disturbed, fast, hot winds associated with interplanetary coronal mass ejections. We furthermore predict the existence of a fourth spectral class, associated with the cool, fast high latitude wind. C1 Univ Groningen, KVI Atom Phys, NL-9747 AA Groningen, Netherlands. Queens Univ Belfast, Dept Phys & Astron, Belfast BT7 1NN, Antrim, North Ireland. Univ Strathclyde, Atom Beams & Plasma Grp, Glasgow G4 0NG, Lanark, Scotland. NOAA, Space Environm Ctr, Boulder, CO 80305 USA. Johns Hopkins Univ, Appl Phys Lab, Planetary Explorat Grp, Dept Space, Laurel, MD 20723 USA. Max Planck Inst Extraterr Phys, D-85748 Garching, Germany. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. NASA, Ames Res Ctr, Cambridge, MA 02138 USA. RP Bodewits, D (reprint author), Univ Groningen, KVI Atom Phys, Zernikelaan 25, NL-9747 AA Groningen, Netherlands. EM bodewits@kvi.nl; d.christian@qub.ac.uk; torney@phys.strath.ac.uk; murray.dryer@noaa.gov; carey.lisse@jhuapl.edu; kod@mpe.mpg.de; thomasz@umich.edu; swolk@head.cfa.harvard.edu; tielens@astro.rug.nl; hoekstra@kvi.nl RI Hoekstra, Ronnie/E-9279-2012; Lisse, Carey/B-7772-2016; OI Lisse, Carey/0000-0002-9548-1526; Wolk, Scott/0000-0002-0826-9261; Bodewits, Dennis/0000-0002-2668-7248; Christian, Damian/0000-0003-1746-3020 NR 74 TC 40 Z9 40 U1 0 U2 2 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2007 VL 469 IS 3 BP 1183 EP U114 DI 10.1051/0004-6361:20077410 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 185WD UT WOS:000247740200041 ER PT J AU Melendez, M Bautista, MA Badnell, NR AF Melendez, M. Bautista, M. A. Badnell, N. R. TI Atomic data from the IRON project - LXIV. Radiative transition rates and collision strengths for CaII SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE atomic data; atomic processes; line : formation ID ELECTRON-IMPACT EXCITATION; ACTIVE GALACTIC NUCLEI; CROSS-SECTIONS; OSCILLATOR-STRENGTHS; RELATIVISTIC CORRECTIONS; LIFETIME MEASUREMENTS; LASER EXCITATION; RESONANCE LINES; EMISSION-LINES; ENERGY-LEVELS AB Aims. This work reports radiative transition rates and electron impact excitation rate coefficients for levels of the n = 3, 4, 5, 6, 7, 8 configurations of Ca II. Methods. The radiative data were computed using the Thomas-Fermi-Dirac central potential method in the frozen core approximation and includes the polarization interaction between the valence electron and the core using a model potential. This method allows for configuration interactions (CI) and relativistic effects in the Breit-Pauli formalism. Collision strengths in LS-coupling were calculated in the close coupling approximation with the R-matrix method. Then, fine structure collision strengths were obtained by means of the intermediate-coupling frame transformation (ICFT) method which accounts for spin-orbit coupling effects. Results. We present extensive comparisons with the most recent calculations and measurements for Ca II as well as a comparison between the core polarization results and the "unpolarized" values. We find that core polarization affects the computed lifetimes by up to 20%. Our results are in very close agreement with recent measurements for the lifetimes of metastable levels. The present collision strengths were integrated over a Maxwellian distribution of electron energies and the resulting effective collision strengths are given for a wide range of temperatures. Our effective collision strengths for the resonance transitions are within similar to 11% from previous values derived from experimental measurements, but disagree with later computations using the distorted wave approximation. C1 Catholic Univ Amer, Inst Astrophys & Computat Sci, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. Inst Venezolano Invest Cient, Ctr Fis, Caracas 1020A, Venezuela. Univ Strathclyde, Dept Phys, Glasgow G4 0NG, Lanark, Scotland. RP Melendez, M (reprint author), Catholic Univ Amer, Inst Astrophys & Computat Sci, Dept Phys, Washington, DC 20064 USA. EM bautista@kant.ivic.ve NR 59 TC 24 Z9 24 U1 1 U2 3 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2007 VL 469 IS 3 BP 1203 EP 1209 DI 10.1051/0004-6361:20077262 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 185WD UT WOS:000247740200043 ER PT J AU Marleau, FR Fadda, D Appleton, PN Noriega-Crespo, A Im, M Clancy, D AF Marleau, F. R. Fadda, D. Appleton, P. N. Noriega-Crespo, A. Im, M. Clancy, D. TI Spectroscopic survey of 1.4 GHz and 24 mu m sources in the Spitzer First Look Survey with WIYN Hydra SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : bulges; galaxies : evolution; galaxies : high-redshift; galaxies : spiral; galaxies : starburst; infrared : galaxies ID STAR-FORMING GALAXIES; TELESCOPE EXTRAGALACTIC 1ST; FRANCE REDSHIFT SURVEY; SPACE-TELESCOPE; 1ST-LOOK SURVEY; STARBURST GALAXIES; LUMINOSITY FUNCTIONS; SOURCE COUNTS; RADIO-SOURCES; MIDINFRARED PROPERTIES AB We present an optical spectroscopic survey of 24 mu m and 1.4 GHz sources, detected in the Spitzer extragalactic First Look Survey ( FLS), using the multifiber spectrograph, Hydra, on the WIYN telescope. We have obtained spectra for 772 sources, with flux densities above 0.15 mJy in the infrared and 0.09mJy in the radio. The redshifts measured in this survey are mostly in the range 0 < z < 0.4, with a distribution peaking at z similar to 0.2. Detailed spectral analysis of our sources reveals that the majority are emission-line star-forming galaxies, with star formation rates in the range 0.2Y 200 M-circle dot yr(-1). The rates estimated from the H alpha line fluxes are found to be on average consistent with those derived from the 1.4 GHz luminosities. For these star-forming systems, we find that the 24 mu m and 1.4 GHz flux densities follow an infrared-radio correlation, which can be characterized by a value of q(24) = 0.83, with a 1 sigma scatter of 0.31. Our WIYN Hydra database of spectra nicely complements those obtained by the Sloan Digital Sky Survey in the region at lower redshift, as well as the MMT Hectospec survey by Papovich et al. in 2006, and brings the redshift completeness to 70% for sources brighter than 2 mJy at 24 mu m. Applying the classical 1/V-max method, we derive new 24 mu m and 1.4 GHz luminosity functions, using all known redshifts in the FLS. We find evidence for evolution in both the 1.4 GHz and 24 mu m luminosity functions in the redshift range 0 < z < 1. The redshift catalog and spectra presented in this paper are available at the Spitzer FLS Web site. C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. CALTECH, NASA, Herschel Sci Ctr, Pasadena, CA 91125 USA. Seoul Natl Univ, FPRD, Dept Phys & Astron, Seoul, South Korea. RP Marleau, FR (reprint author), CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. RI Im, Myungshin/B-3436-2013 OI Im, Myungshin/0000-0002-8537-6714 NR 61 TC 24 Z9 24 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 JUL 1 PY 2007 VL 663 IS 1 BP 218 EP 233 DI 10.1086/518114 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182ZO UT WOS:000247542700017 ER PT J AU Fitzpatrick, EL Massa, D AF Fitzpatrick, E. L. Massa, D. TI An analysis of the shapes of interstellar extinction curves. V. The IR-through-UV curve morphology SO ASTROPHYSICAL JOURNAL LA English DT Review DE dust; extinction; methods : data analysis ID EARLY-TYPE STARS; ORION-NEBULA CLUSTER; INTRINSIC ENERGY-DISTRIBUTION; EXTREMELY YOUNG CLUSTERS; SOUTHERN OB STARS; H-II REGIONS; ULTRAVIOLET EXTINCTION; SPECTRAL TYPES; B-STARS; PHYSICAL-PROPERTIES AB We study the IR-through-UV wavelength dependence of 328 Galactic interstellar extinction curves affecting normal, near-main-sequence B and late O stars. We derive the curves using a new technique that employs stellar atmosphere models in lieu of unreddened "standard'' stars. Under ideal conditions, this technique is capable of virtually eliminating spectral mismatch errors in the curves. In general, it lends itself to a quantitative assessment of the errors and enables a rigorous testing of the significance of relationships between various curve parameters, regardless of whether their uncertainties are correlated. Analysis of the curves gives the following results: 1. In accord with our previous findings, the central position of the 2175 8 extinction bump is mildly variable, its width is highly variable, and the two variations are unrelated. 2. Strong correlations are found among some extinction properties within the UV region, and within the IR region. 3. With the exception of a few curves with extreme (i.e., large) values of R(V), the UVand IR portions of Galactic extinction curves are not correlated with each other. 4. The large sight line-to-sight line variation seen in our sample implies that any average Galactic extinction curve will always reflect the biases of its parent sample. 5. The use of an average curve to deredden a spectral energy distribution (SED) will result in significant errors, and a realistic error budget for the dereddened SED must include the observed variance of Galactic curves. While the observed large sight line-to-sight line variations, and the lack of correlation among the various features of the curves, make it difficult to meaningfully characterize average extinction properties, they demonstrate that extinction curves respond sensitively to local conditions. Thus, each curve contains potentially unique information about the grains along its sight line. C1 Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. NASA, Goddard Space Flight Ctr, SGT Inc, Greenbelt, MD 20771 USA. RP Fitzpatrick, EL (reprint author), Villanova Univ, Dept Astron & Astrophys, 800 Lancaster Ave, Villanova, PA 19085 USA. EM fitz@astronomy.villanova.edu; massa@derckmassa.net NR 141 TC 246 Z9 246 U1 2 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2007 VL 663 IS 1 BP 320 EP 341 DI 10.1086/518158 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182ZO UT WOS:000247542700026 ER PT J AU Wyatt, MC Smith, R Su, KYL Rieke, GH Greaves, JS Beichman, CA Bryden, G AF Wyatt, M. C. Smith, R. Su, K. Y. L. Rieke, G. H. Greaves, J. S. Beichman, C. A. Bryden, G. TI Steady state evolution of debris disks around a stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary systems : formation ID EDGEWORTH-KUIPER BELT; MAIN-SEQUENCE STARS; PICTORIS DUST DISK; CIRCUMSTELLAR DISK; BETA-PICTORIS; SOLAR-SYSTEM; COLLISIONAL CASCADES; SUBMILLIMETER IMAGES; PLANETESIMAL DISKS; VEGA PHENOMENON AB This paper confronts a simple analytical model for the steady state evolution of debris disks due to collisions with Spitzer observations of dust around main-sequence A stars. It is assumed that every star has a planetesimal belt, the initial mass and radius of which are drawn from distributions. In the model disk mass is constant until the largest planetesimals reach collisional equilibrium, whereupon mass falls alpha t(age)(-1). We find that the detection statistics and trends seen at 24 and 70 mu m can be fitted well by the model. While there is no need to invoke stochastic evolution or delayed stirring to explain the statistics, a moderate rate of stochastic events is not ruled out. Potentially anomalous systems are identified by a high dust luminosity compared with the maximum permissible in the model (HD 3003, HD 38678, HD 115892, HD 172555); their planetesimals may have unusual properties (high strength or low eccentricity), or this dust could be transient. The overall success of our model, which assumes planetesimals in all belts have the same strength, eccentricity, and maximum size, suggests the outcome of planet formation is reasonably uniform. The distribution of planetesimal belt radii, once corrected for detection bias, follows N(r) alpha r(-0.8 +/- 0.3) for 3-120 AU. Since belt boundaries may be attributed to unseen planets, this provides a unique constraint on A star planetary systems. It is also shown that P-R drag may sculpt the inner edges of A star disks close to the Spitzer detection threshold (HD 2262, HD 19356, HD106591, HD115892). This model can be readily applied to the interpretation of future surveys, and predictions for the upcoming SCUBA-2 survey include that 17% of A star disks should be detectable at 850 mu m. C1 Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Royal Observ, Inst Astron, Edinburgh EH9 3HJ, Midlothian, Scotland. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ St Andrews, Scottish Univ Phys Alliance, St Andrews KY16 9SS, Fife, Scotland. Jet Propuls Lab, Pasadena, CA 91109 USA. RP Wyatt, MC (reprint author), Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England. EM wyatt@ast.cam.ac.uk OI Su, Kate/0000-0002-3532-5580 NR 67 TC 140 Z9 140 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 JUL 1 PY 2007 VL 663 IS 1 BP 365 EP 382 DI 10.1086/518404 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182ZO UT WOS:000247542700029 ER PT J AU Pascucci, I Hollenbach, D Najita, J Muzerolle, J Gorti, U Herczeg, GJ Hillenbrand, LA Kim, JS Carpenter, JM Meyer, MR Mamajek, EE Bouwman, J AF Pascucci, I. Hollenbach, D. Najita, J. Muzerolle, J. Gorti, U. Herczeg, G. J. Hillenbrand, L. A. Kim, J. S. Carpenter, J. M. Meyer, M. R. Mamajek, E. E. Bouwman, J. TI Detection of [Ne II] emission from young circumstellar disks SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; line : identification; planetary systems : protoplanetary disks; stars : individual (HD 143006; PDS 66; [PZ99] J161411.0-230536; RX J1111.7-7620; RX J1842.9-3532; RX J1852.3-3700) ID T-TAURI STARS; ALL-SKY SURVEY; MAIN-SEQUENCE STARS; SCORPIUS OB ASSOCIATION; SUN-LIKE STARS; X-RAY; PLANETARY-SYSTEMS; LINEAR-REGRESSION; ACCRETION RATES; FORMING REGION AB We report the detection of [Ne II] emission at 12.81 mu m in four out of the six optically thick dust disks observed as part of the FEPS Spitzer Legacy program. In addition, we detect a H I (7-6) emission line at 12.37 mu m from the source RX J1852.3 - 3700. Detections of [Ne II] lines are favored by low mid-infrared excess emission. Both stellar X-rays and extreme ultraviolet (EUV) photons can sufficiently ionize the disk surface to reproduce the observed line fluxes, suggesting that emission from Ne+ originates in the hot disk atmosphere. On the other hand, the H I (7-6) line is not associated with the gas in the disk surface, and magnetospheric accretion flows can account for at most similar to 30% of the observed flux. We conclude that accretion shock regions and/or the stellar corona could contribute to most of the H I (7-6) emission. Finally, we discuss the observations necessary to identify whether stellar X-rays or EUV photons are the dominant ionization mechanismfor Ne atoms. Because the observed [Ne II] emission probes very small amounts of gas in the disk surface (similar to 10(-6) M-J) we suggest using this gas line to determine the presence or absence of gas in more evolved circumstellar disks. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, Pasadena, CA 91125 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. RP Pascucci, I (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. OI Herczeg, Gregory/0000-0002-7154-6065 NR 57 TC 85 Z9 85 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 JUL 1 PY 2007 VL 663 IS 1 BP 383 EP 393 DI 10.1086/518535 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182ZO UT WOS:000247542700030 ER PT J AU Shaposhnikov, N Titarchuk, L AF Shaposhnikov, Nickolai Titarchuk, Lev TI Determination of black hole mass in Cygnus X-1 by scaling of spectral index-QPO frequency correlation SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion; accretion disks; black hole physics; radiation mechanisms : nonthermal; stars : individual (Cygnus X-1) ID QUASI-PERIODIC OSCILLATION; X-RAY BINARIES; NEUTRON-STAR; GRO J1655-40; FEATURES AB It is well established that timing and spectral properties of Galactic black hole (BH) X-ray binaries (XRB) are strongly correlated. In particular, it has been shown that low-frequency quasi-periodic oscillation (QPO) log v(low) - photon index Gamma correlation curves have a specific pattern. In a number of sources the shape of the index-low-frequency QPO correlations are self-similar with a position offset in the log v(low)-Gamma plane. Titarchuk & Fiorito presented strong theoretical and observational arguments that the QPO frequency values in this log v(low)-Gamma correlation should be inversely proportional to M-BH. A simple translation of the correlation for a given source along the frequency axis leads to the observed correlation for another source. As a result of this translation one can obtain a scaling factor that is simply a BH mass ratio for these particular sources. This property of the correlations offers a fundamentally new method for BH mass determination in XRBs. Here we use the observed QPOYindex correlations observed in three BH sources: GRO J1655 - 40, GRS 1915 + 105, and Cyg X-1. The BH mass of 6.3 +/- 0.5 M-circle dot in GRO J1655 - 40 is obtained using optical observations. RXTE observations during the recent 2005 outburst yielded sufficient data to establish the correlation pattern during both the rise and decay of the event. We use GRO J1655 - 40 as a standard reference source to measure the BH mass in Cyg X-1. We also revisit the GRS 1915+105 data as a further test of our scaling method. We infer the value of BH mass of 15.6 +/- 1.5M(circle dot) in this source, which is consistent with the previous BH mass estimate in GRS 1915 of 13.3 +/- 4 M-circle dot. We obtain the BH mass in Cyg X-1 in the range of 8.7 +/- 0.8 M-circle dot. C1 Univ Space Res Assoc, CRESST, Columbia, MD 21044 USA. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. George Mason Univ, Ctr Earth Observ & Space Res, Fairfax, VA 22030 USA. USN, Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Shaposhnikov, N (reprint author), Univ Space Res Assoc, CRESST, 10211 Wincopin Cir,Suite 500, Columbia, MD 21044 USA. EM nikolai@milkyway.gsfc.nasa.gov; lev.titarchuk@nrl.navy.mil NR 28 TC 43 Z9 43 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2007 VL 663 IS 1 BP 445 EP 449 DI 10.1086/518110 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182ZO UT WOS:000247542700036 ER PT J AU Hamaguchi, K Corcoran, MF Gull, T Ishibashi, K Pittard, JM Hillier, DJ Damineli, A Davidson, K Nielsen, KE Kober, GV AF Hamaguchi, Kenji Corcoran, Michael F. Gull, Theodore Ishibashi, Kazunori Pittard, Julian M. Hillier, D. John Damineli, Augusto Davidson, Kris Nielsen, Krister E. Kober, Gladys Vieira TI X-ray spectral variation of eta carinae through the 2003 X-ray minimum SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; stars : early-type; stars : individual (eta Carinae); stars : winds; outflows; X-rays : stars ID ABSORPTION CROSS-SECTIONS; XMM-NEWTON; SPECTROSCOPIC EVENT; HOMUNCULUS NEBULA; BINARY HYPOTHESIS; STELLAR WIND; ZETA-PUPPIS; EMISSION; ASCA; CHANDRA AB We report the results of an observing campaign on mu Car around the 2003 X- ray minimum, mainly using the XMM-Newton observatory. These are the first spatially resolved X- ray monitoring observations of the stellar X- ray spectrum during the minimum. The hard X- ray emission, associated with the wind-wind collision (WWC) in the binary system, varied strongly in flux on timescales of days, but not significantly on timescales of hours. The X- ray flux in the 2-10 keV band seen by XMM-Newton was only 0.7% of the flux maximum seen by RXTE. The slope of the X- ray continuum above 5 keV did not vary in any observation, which suggests that the electron temperature of the hottest plasma did not vary significantly at any phase. Through the minimum, the absorption to the stellar source increased by a factor of 5-10 to N-H similar to (3-4); 10(23) cm(-2). These variations were qualitatively consistent with emission from the WWC plasma entering into the dense wind of the massive primary star. During the minimum, X- ray spectra also showed significant excesses in the thermal Fe XXV emission line on the red side, while they showed only a factor of 2 increase in equivalent width of the Fe fluorescence line at 6.4 keV. These features are not fully consistent with the eclipse of the X- ray plasma and may suggest an intrinsic fading of the X- ray emissivity. The drop in the WWC emission revealed the presence of an additional X- ray component that exhibited no variation on timescales of weeks to years. This component may be produced by the collision of high-speed outflows at v similar to 1000-2000 km s(-1) from eta Car with ambient gas within a few thousand AU from the star. C1 NASA, Goddard Space Flight Ctr, CRESST, X Ray Astrophys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. Univ Leeds, Sch Phys & Astron, Leeds LS2 9JT, W Yorkshire, England. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. IAGUSP, Dept Astron, BR-05508900 Sao Paulo, Brazil. Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA. Catholic Univ Amer, Washington, DC 20064 USA. RP Hamaguchi, K (reprint author), NASA, Goddard Space Flight Ctr, CRESST, X Ray Astrophys Lab, Greenbelt, MD 20771 USA. EM kenji@milkyway.gsfc.nasa.gov RI Damineli, Augusto/D-8210-2012; Gull, Theodore/D-2753-2012 OI Damineli, Augusto/0000-0002-7978-2994; Gull, Theodore/0000-0002-6851-5380 NR 73 TC 58 Z9 58 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 JUL 1 PY 2007 VL 663 IS 1 BP 522 EP 542 DI 10.1086/518101 PN 1 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182ZO UT WOS:000247542700044 ER PT J AU Sekanina, Z Chodas, PW AF Sekanina, Zdenek Chodas, Paul W. TI Fragmentation hierarchy of bright sungrazing comets and the birth and orbital evolution of the Kreutz system. II. The case for cascading fragmentation SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; methods : data analysis ID SPLIT COMETS; RELATIVE MOTIONS; ORIGIN; SOLAR; MODEL AB We examine the process of cascading fragmentation for the Kreutz sungrazer system to continue our exploration of its birth, orbital evolution, and temporal clumping. We modify and broaden the two-superfragment model from Paper I to include clusters of similar to 30 bright comets spanning four centuries and 1000 SOHO sungrazers from 1996 to 2006. The spectacular parent sungrazer X/1106 C1 is assumed to have tidally split shortly after perihelion into a train of major protofragments immersed in a cloud of particulate debris, which at larger heliocentric distances were breaking up nontidally over and over again. We describe potential evolutionary paths for the Kreutz system by linking X/ 1106 C1 in subgroup I-type orbit with the comet of February 423 in one scenario or with the comet of February 467 in another. The latter scenario accounts for sungrazer clusters in as early as the 16th century, suggests that the progenitor object may have been observed as the comet of 214 BCE, is quite consistent with the orbital distribution of the SOHO sungrazers that sample the central filament of the Kreutz system between the clusters of major sungrazers, and predicts future clusters until similar to 2120. Comet X/1106 C1 and the common parent of C/1882 R1 and C/1965 S1 were two first-generation fragments of the progenitor that split nontidally on the way to its 5th century perihelion, reminiscent of the superfragments in Paper I. We provide computational tools needed for solving the problem of the Kreutz system's orbital evolution, but no unique scenarios are presented for the individual comets. Another cluster of bright sungrazers is expected to arrive in the coming decades, its earliest member possibly just several years from now. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sekanina, Z (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM zs@sek.jpl.nasa.gov; paul.w.chodas@jpl.nasa.gov NR 55 TC 22 Z9 22 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2007 VL 663 IS 1 BP 657 EP 676 DI 10.1086/517490 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182ZO UT WOS:000247542700055 ER PT J AU Stern, D Kirkpatrick, JD Allen, LE Bian, C Blain, A Brand, K Brodwin, M Brown, MJI Cool, R Desai, V Dey, A Eisenhardt, P Gonzalez, A Jannuzi, BT Menendez-Delmestre, K Smith, HA Soifer, BT Tiede, GP Wright, E AF Stern, Daniel Kirkpatrick, J. Davy Allen, Lori E. Bian, Chao Blain, Andrew Brand, Kate Brodwin, Mark Brown, Michael J. I. Cool, Richard Desai, Vandana Dey, Arjun Eisenhardt, Peter Gonzalez, Anthony Jannuzi, Buell T. Menendez-Delmestre, Karin Smith, Howard A. Soifer, B. T. Tiede, Glenn P. Wright, E. TI Mid-infrared selection of brown dwarfs and high-redshift quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : high-redshift; quasars : individual (IRAC J142738.5+331242); stars : individual (IRAC J142950.8+333011); stars : low-mass, brown dwarfs; surveys ID WIDE-FIELD SURVEY; SPITZER-SPACE-TELESCOPE; IRAC SHALLOW SURVEY; ARRAY CAMERA IRAC; SPECTRAL TYPE-L; T-DWARFS; RADIO-LOUD; SKY SURVEY; SPECTROSCOPIC SURVEY; LUMINOSITY FUNCTION AB We discuss color selection of rare objects in a wide-field multiband survey spanning from the optical to the mid-infrared. Simple color criteria simultaneously identify and distinguish two of the most sought after astrophysical sources: the coolest brown dwarfs and the most distant quasars. We present spectroscopically confirmed examples of each class identified in the IRAC Shallow Survey of the Bootes field of the NOAO Deep Wide-Field Survey. IRAC J142950.8 + 333011 is a T4.5 brown dwarf at a distance of approximately 30-40 pc, and IRAC J142738.5 + 331242 is a radio-loud quasar at redshift z = 6.12. Our selection criteria identify a total of four candidates over 8 deg(2) of the Boo r tes field. The other two candidates are both confirmed 5.5 < z < 6 quasars, previously reported by Cool et al. (2006). We discuss the implications of these discoveries and conclude that there are excellent prospects for extending such searches to cooler brown dwarfs and higher redshift quasars. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Princeton Univ, Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Natl Opt Astron Observ, Tucson, AZ 85719 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Bowling Green State Univ, Dept Phys & Astron, Bowling Green, OH 43403 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Stern, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM stern@zwolfkinder.jpl.nasa.gov RI Brown, Michael/B-1181-2015 OI Brown, Michael/0000-0002-1207-9137 NR 59 TC 36 Z9 36 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 JUL 1 PY 2007 VL 663 IS 1 BP 677 EP 685 DI 10.1086/516833 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182ZO UT WOS:000247542700056 ER PT J AU Satyapal, S Vega, D Heckman, T O'Halloran, B Dudik, R AF Satyapal, S. Vega, D. Heckman, T. O'Halloran, B. Dudik, R. TI The discovery of an active galactic nucleus in the late-type galaxy NGC 3621: Spitzer spectroscopic observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; galaxies : active; galaxies : nuclei; galaxies : spiral; infrared : galaxies ID SUPERMASSIVE BLACK-HOLES; SPACE-TELESCOPE; INFRARED SPECTROGRAPH; SIGMA RELATION; HOST GALAXIES; MASS; BULGE; SINGS; CONNECTION; QUASARS AB We report the discovery of an active galactic nucleus ( AGN) in the nearby SAd galaxy NGC 3621 using Spitzer high spectral resolution observations. These observations reveal the presence of [ Ne v] 14 and 24 mm emission that is centrally concentrated and peaks at the position of the near-infrared nucleus. Using the [ Ne v] line luminosity, we estimate that the nuclear bolometric luminosity of the AGN is similar to 5 x 10(41) ergs s(-1), which, based on the Eddington limit, corresponds to a lower mass limit of the black hole of similar to 4 x 10(3) M-circle dot. Using an order-of-magnitude estimate for the bulge mass based on the Hubble type of the galaxy, we find that this lower mass limit does not put a strain on the well-known relationship between the black hole mass and the host galaxy's stellar velocity dispersion established in predominantly early- type galaxies. Multiwavelength follow- up observations of NGC 3621 are required to obtain more precise estimates of the bulge mass, black hole mass, accretion rate, and nuclear bolometric luminosity. The discovery reported here adds to the growing evidence that a black hole can form and grow in a galaxy with no or minimal bulge. C1 George Mason Univ, Dept Phys & Astron, Fairfax, VA 22030 USA. Johns Hopkins Univ, Dept Phys & Astron, Ctr Astrophys Sci, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. RP Satyapal, S (reprint author), George Mason Univ, Dept Phys & Astron, MS 3F3,4400 Univ Dr, Fairfax, VA 22030 USA. EM satyapal@physics.gmu.edu NR 40 TC 63 Z9 63 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 JUL 1 PY 2007 VL 663 IS 1 BP L9 EP L12 DI 10.1086/519995 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182YH UT WOS:000247539400003 ER PT J AU Williams, JP Gaidos, E AF Williams, Jonathan P. Gaidos, Eric TI On the likelihood of supernova enrichment of protoplanetary disks SO ASTROPHYSICAL JOURNAL LA English DT Article DE planetary systems : formation; planetary systems : protoplanetary; disks stars : formation ID CIRCUMSTELLAR DISKS; MOLECULAR CLOUDS; SOLAR-SYSTEM; OB ASSOCIATIONS; MASSIVE STARS; CLUSTER; ORION; LUMINOSITY; PROPLYDS; NEBULA AB We estimate the likelihood of direct injection of supernova ejecta into protoplanetary disks using a model in which the number of stars with disks decreases linearly with time, and clusters expand linearly with time such that their surface density is independent of stellar number. The similarity of disk dissipation and main- sequence lifetimes implies that the typical supernova progenitor is very massive, similar to 75-100 M-circle dot. Such massive stars are found only in clusters with greater than or similar to 10(4) members. Moreover, there is only a small region around a supernova within which disks can survive the blast yet be enriched to the level observed in the solar system. These two factors limit the overall likelihood of supernova enrichment of a protoplanetary disk to less than or similar to 1%. If the presence of shortlived radionucleides in meteorites is to be explained in this way, however, the solar system most likely formed in one of the largest clusters in the Galaxy, more than 2 orders of magnitude greater than Orion, where multiple supernovae impacted many disks in a short period of time. C1 Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Hawaii, NASA, Astrobiol Inst, Honolulu, HI 96822 USA. Univ Hawaii, Dept Geol & Geophys, Honolulu, HI 96822 USA. RP Williams, JP (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. RI Williams, Jonathan/B-1643-2009; OI Williams, Jonathan/0000-0001-5058-695X NR 29 TC 35 Z9 35 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 JUL 1 PY 2007 VL 663 IS 1 BP L33 EP L36 DI 10.1086/519972 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182YH UT WOS:000247539400009 ER PT J AU Mullally, F Kilic, M Reach, WT Kuchner, MJ von Hippel, T Burrows, A Winget, DE AF Mullally, F. Kilic, Mukremin Reach, William T. Kuchner, Marc J. von Hippel, Ted Burrows, Adam Winget, D. E. TI A Spitzer white dwarf infrared survey SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE infrared : stars; surveys; white dwarfs ID IA PROGENITOR SURVEY; PALOMAR-GREEN SURVEY; LOW-MASS STARS; SPACE-TELESCOPE; BROWN DWARF; THEORETICAL SPECTRA; SUBSTELLAR OBJECTS; STELLAR GRAVEYARD; METAL ABUNDANCE; COOL CUSTOMERS AB We present mid-infrared photometry of 124 white dwarf stars with the Spitzer Space Telescope. Objects were observed simultaneously at 4.5 and 8.0 mu m with sensitivities better than 0.1 mJy. This data set can be used to test models of white dwarf atmospheres in a new wavelength regime, as well as to search for planetary companions and debris disks. C1 Univ Texas, Dept Astron, Austin, TX 78712 USA. CALTECH, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Mullally, F (reprint author), Univ Texas, Dept Astron, RLM 15308, Austin, TX 78712 USA. RI Reach, William/C-4710-2008; Kuchner, Marc/E-2288-2012; OI Reach, William/0000-0001-8362-4094 NR 53 TC 57 Z9 57 U1 1 U2 3 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 2007 VL 171 IS 1 BP 206 EP 218 DI 10.1086/511858 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182ZL UT WOS:000247542400007 ER PT J AU Kumar, N Chu, A Foster, A AF Kumar, Naresh Chu, Allen Foster, Andrew TI An empirical relationship between PM2.5 and aerosol optical depth in Delhi Metropolitan SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE PM2.5; aerosol optical depth (AOD); air pollution; remote sensing ID ATMOSPHERE; MODIS; LAND; AIR AB Atmospheric remote sensing offers a unique opportunity to compute indirect estimates of air quality, which are critically important for the management and surveillance of air quality in megacities of developing countries, particularly in India and China, which have experienced elevated concentration of air pollution but lack adequate spatial-temporal coverage of air pollution monitoring. This article examines the relationship between aerosol optical depth (AOD) estimated from satellite data at 5 kin spatial resolution and the mass of fine particles <= 2.5 mu m in aerodynamic diameter (PM2.5) monitored on the ground in Delhi Metropolitan where a series of environmental laws have been instituted in recent years. PM2.5 monitored at 113 sites were collocated by time and space with the AOD computed using the data from Moderate Resolution Imaging Spectroradiometer (MODIS onboard the Terra satellite). MODIS data were acquired from NASA's Goddard Space Flight Center Earth Sciences Distributed Active Archive Center (DAAC). Our analysis shows a significant positive association between AOD and PM2.5. After controlling for weather conditions, a I% change in AOD explains 0.52 +/- 0.202% and 0.39 +/- 0.15% change in PM2.5 monitored within +/- 45 and 150min intervals of AOD data. This relationship will be used to estimate air quality surface for previous years, which will allow us to examine the time-space dynamics of air pollution in Delhi following recent air quality regulations, and to assess exposure to air pollution before and after the regulations and its impact on health. (c) 2007 Elsevier Ltd. All rights reserved. C1 Univ Iowa, Dept Geog, Iowa City, IA 52242 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Brown Univ, Dept Econ, Providence, RI 02912 USA. RP Kumar, N (reprint author), Univ Iowa, Dept Geog, 316 Jessup Hall, Iowa City, IA 52242 USA. EM naresh-kumar@uiowa.edu; achu@climate.gsfc.nasa.gov; Andrew_Foster@Brown.edu RI Wang, Linden/M-6617-2014 FU NICHD NIH HHS [R21 HD046571, R21 HD046571-01A1, R21 HD046571-02] NR 21 TC 95 Z9 104 U1 7 U2 45 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUL PY 2007 VL 41 IS 21 BP 4492 EP 4503 DI 10.1016/j.atmosenv.2007.01.046 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 186WY UT WOS:000247810500012 PM 22180723 ER PT J AU Rickards, CA Cohen, KD Bergeron, LL Burton, L Khatri, PJ Lee, CT Ryan, KL Cooke, WH Doerr, DF Convertino, VA AF Rickards, Caroline A. Cohen, Kenneth D. Bergeron, Lindsey L. Burton, Lubrina Khatri, Prateek J. Lee, Christopher T. Ryan, Kathy L. Cooke, William H. Doerr, Donald F. Convertino, Victor A. TI Cerebral blood flow response and its association with symptoms during orthostatic hypotension SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE cerebral autoregulation; squat-stand test; orthostatic symptoms ID HEAD-UP TILT; TRANSCRANIAL DOPPLER; AUTONOMIC FAILURE; HEALTHY-SUBJECTS; FINGER ARTERIAL; CARDIAC-OUTPUT; AUTOREGULATION; HUMANS; PRESSURE; VELOCITY AB Introduction: The preservation of cerebral blood flow with orthostatic hypotension (e.g., following prolonged bed rest or microgravity exposure) is vital for the attenuation of symptoms and the maintenance of consciousness. We tested the hypothesis that decreasing mean arterial pressure (MAP) by > 30% is associated with compromised cerebral autoregulation and orthostatic symptoms during a squat-stand test (SST). Methods: There were 19 subjects who performed an SST. MAP and middle cerebral artery blood flow velocity (CBFV) were recorded continuously. Subjects were divided retrospectively into those who reported: 1) at least one orthostatic symptom (Sx; n = 9); or 2) no orthostatic symptoms (NSx; n = 10). Cerebral autoregulation was assessed via the calculation of time to nadir and time to recovery for MAP and CBFV and linear regression analysis of the dynamic changes in MAP and CBFV (within 10 s of standing). Results: On standing, MAP decreased by 37 +/- 2% (NSx) and 42 +/- 4% (Sx) (p = 0.100). CBFV fell by 6% more in the Sx group than in the NSx group(NSx, -33 +/- 1% vs. Sx, -39 +/- 3%, p = 0.032). Cerebral autoregulation remained intact in both groups as indicated by: 1) a faster time to nadir for CBFV compared with MAP; 2) a faster time to recovery for CBFV compared with MAP; and 3) a poor correlation between CBFV and MAP responses on standing (NSx R-2 = 0.43; Sx R-2 = 0.60). Conclusion: Lower cerebral blood flow during severe hypotension may account for the reporting of orthostatic symptoms, despite the maintenance of cerebral autoregulation. C1 USA, Inst Surg Res, Ft Sam Houston, TX 78234 USA. Bionet Corp, NASA, Kennedy Space Ctr, FL USA. NASA, Spaceflight & Life Sci Training Program, Kennedy Space Ctr, FL USA. NASA, Technol Implementat Branch, Kennedy Space Ctr, FL USA. Univ Texas, Dept Hlth & Kinesiol, San Antonio, TX 78285 USA. RP Rickards, CA (reprint author), USA, Inst Surg Res, 3400 Rawley e Chambers Ave Bldg 3611, Ft Sam Houston, TX 78234 USA. NR 37 TC 10 Z9 10 U1 0 U2 1 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 2007 VL 78 IS 7 BP 653 EP 658 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 186KA UT WOS:000247776400002 PM 17679561 ER PT J AU Richmond, RH Rongo, T Golbuu, Y Victor, S Idechong, N Davis, G Kostka, W Neth, L Hamnett, M Wolanski, E AF Richmond, Robert H. Rongo, Teina Golbuu, Yimnang Victor, Steven Idechong, Noah Davis, Gerry Kostka, Willy Neth, Leinson Hamnett, Michael Wolanski, Eric TI Watersheds and coral reefs: Conservation science, policy, and implementation SO BIOSCIENCE LA English DT Article DE coral reefs; watersheds; sedimentation; conservation; traditional knowledge ID GREAT-BARRIER-REEF; MICRONESIA; SEDIMENTATION; ORGANISMS; ECOLOGY; HEALTH; IMPACT; ISLAND; BAY AB Coral reefs worldwide are being degraded by human-induced disturbances, resulting in ecological, economic, and cultural losses. Runoff and sedimentation are among the greatest threats to the coastal reefs surrounding high islands and adjacent to continental landmasses. Existing scientific data identify the key stressors, synergisms, and outcomes at the coral reef ecosystem, community, and population levels. These data demonstrate that marine protected areas alone may be insufficient for coral reef protection; integrated watershed management practices are also needed. Gaps in the effectiveness of environmental policy, legislation, and regulatory enforcement have resulted in the continued degradation of US and Australian reefs. Several Pacific islands, with intact resource stewardship and traditional leadership systems, have been able to apply research findings to coral reef management policies relatively quickly. Three case histories in Micronesia provide insight into how social sciences and biophysical data can be combined to manage human behaviors responsible for coral reef destruction. C1 Univ Hawaii Manoa, Pacific Biosci Res Ctr, Kewalo Marine Lab, Honolulu, HI 96813 USA. Florida Inst Technol, Dept Biol Sci, Melbourne, FL 32901 USA. Palau Int Coral Reef Ctr, Koror 96940, Palau. Pacific Isl Reg Off, Natl Marine Fisheries Serv, Honolulu, HI 96813 USA. Univ Hawaii Manoa, Social Sci Res Inst, Res Corp, Honolulu, HI 96822 USA. Australian Inst Marine Sci, Townsville, Qld 4811, Australia. RP Richmond, RH (reprint author), Univ Hawaii Manoa, Pacific Biosci Res Ctr, Kewalo Marine Lab, Honolulu, HI 96813 USA. EM richmond@hawaii.edu RI Richmond, Robert/G-1385-2014 NR 32 TC 57 Z9 60 U1 5 U2 32 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 USA SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD JUL-AUG PY 2007 VL 57 IS 7 BP 598 EP 607 DI 10.1641/B570710 PG 10 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 192KX UT WOS:000248201700009 ER PT J AU McDermid, KJ Stuercke, B Balazs, GH AF McDermid, Karla J. Stuercke, Brooke Balazs, George H. TI Nutritional composition of marine plants in the diet of the green sea turtle (Chelonia mydas) in the Hawaiian Islands SO BULLETIN OF MARINE SCIENCE LA English DT Article ID PROXIMATE COMPOSITION; SOMATIC GROWTH; SEAGRASSES; ECOLOGY; FLORIDA; ALGAE; CONSTITUENTS; VARIABILITY; SEAWEEDS; NUMBERS AB In the Hawaiian islands, seaweeds and seagrasses are eaten by green turtles, Chelonia mydas Linnaeus. Sixteen macroalgal species (7 Chlorophyta, 2 Phaeophyta, 7 Rhodophyta), two seagrass species, and multi-specific algal turf from turtle foraging areas on four different islands were analyzed for proximate (protein, lipid, carbohydrate), water, ash, energy, amino acid, vitamin, and mineral content. Pterocladiella capillacea (Gmelin) Santelices and Hommersand, a prominent dietary item, and Rhizoclonium implexum (Dillwyn) Kutzing, an infrequently consumed species, ranked highest in total protein content. Most species contained < 10% crude lipid. Soluble carbohydrates ranged from 3.2%-39.9% dry weight. Ash values ranged from 13.7%-81.4% dry weight. Energy content of P. capillacea was over 14 kJ g(-1) ash-free dry weight. All species tested contained measurable quantities of 11 minerals. Vitamin A (beta-carotene) was detected in all marine plants tested; most contained Niacin (B-3); and Enteromorpha flexuosa (Wulfen) J. Agardh had the highest amount of vitamin C (3 mg g(-1)). Samples contained measurable amounts of all essential amino acids, except for tryptophan. These data provide new information about Hawaiian green turtle feeding ecology and factors that may influence somatic growth rates. C1 Univ Hawaii Hilo, Dept Marine Sci, Hilo, HI 96720 USA. NOAA, Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA. RP McDermid, KJ (reprint author), Univ Hawaii Hilo, Dept Marine Sci, 200 W Kawili St, Hilo, HI 96720 USA. EM mcdermid@hawaii.edu NR 56 TC 19 Z9 19 U1 4 U2 26 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD JUL PY 2007 VL 81 IS 1 BP 55 EP 71 PG 17 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 194PO UT WOS:000248356500004 ER PT J AU Chao, WC Suarez, MJ Bacmeister, JT Chen, B Takacs, LL AF Chao, Winston C. Suarez, M. J. Bacmeister, J. T. Chen, B. Takacs, L. L. TI Why simulating the ITCZ in GCMs is so difficult SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Chao, WC (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD JUL PY 2007 VL 88 IS 7 BP 1024 EP 1025 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 197OQ UT WOS:000248565600013 ER PT J AU Tragardh, E Schlegel, TT AF Tragardh, Elin Schlegel, Todd T. TI High-frequency QRS electrocardiogram SO CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING LA English DT Review DE cardiac disease; electrocardiogram; high-frequency QRS components; reduced amplitude zone; root mean square value ID CORONARY-ARTERY-DISEASE; ACUTE MYOCARDIAL-INFARCTION; SIGNAL-AVERAGED ECG; LEFT-VENTRICULAR MASS; SPECTRAL-ANALYSIS; EPICARDIAL ELECTROGRAM; CARDIAC-SURGERY; HIGH-RESOLUTION; POTENTIALS; ISCHEMIA AB The standard 12-lead electrocardiogram (ECG) is one of the most commonly used methods for diagnosing heart disease. Standard ECG is not always optimal, however, and new ECG methods can provide additional information. Analysis of high-frequency QRS components (HF-QRS) has been shown to increase the diagnostic performance of the ECG. Several investigators have studied HF-QRS in different cardiac conditions, including acute myocardial ischaemia and myocardial infarction, but more knowledge is needed about the characteristics of HF-QRS before clinicians can use it as an adjunct to standard ECG. C1 Univ Lund Hosp, Dept Clin Physiol, S-22185 Lund, Sweden. NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. RP Tragardh, E (reprint author), Univ Lund Hosp, Dept Clin Physiol, S-22185 Lund, Sweden. EM elin.tragardh@med.lu.se NR 43 TC 4 Z9 5 U1 0 U2 5 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1475-0961 J9 CLIN PHYSIOL FUNCT I JI Clin. Physiol. Funct. Imaging PD JUL PY 2007 VL 27 IS 4 BP 197 EP 204 DI 10.1111/j.1475-097X.2007.00738.x PG 8 WC Physiology SC Physiology GA 177TT UT WOS:000247176100001 PM 17564667 ER PT J AU Garces, JE Bozzolo, G Hofman, G Rest, J AF Garces, Jorge E. Bozzolo, Guillermo Hofman, Gerard Rest, Jeffrey TI Modeling of multicomponent systems: Role of Mo and Si on the interaction of Al and gamma-UMo SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article DE uranium; molybdenum; aluminum; silicon; semiempirical methods; modeling; low enrichment fuels ID IRRADIATION BEHAVIOR; DISPERSION FUEL; LOW-TEMPERATURE; ALUMINUM; ALLOY; DIAGRAM; PHASE AB Experimental work based on the analysis of Al/UMo diffusion couples contemplates the addition of other elements for dealing with the known problem of Al diffusion in the gamma-UMo solid solution. In this work, we apply an atomistic modeling tool to gain understanding on the interactions that lead to this behavior, and therefore establish a framework for studying the role of additives via their interaction with Al, U, and Mo. As a first step to do this, we examine the interaction of a thin Al film on a gamma-UMo substrate. It is found that the model reproduces and provides an explanation for the trends observed experimentally, leading to the conclusion that it might be possible to describe the complex problem of the interaction between several elements in a rather simple and straightforward modeling framework. (c) 2006 Elsevier B.V. All rights reserved. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. Ctr Atom Bariloche, CNEA, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Bozzolo, G (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. EM GuillermoBozzolo@oai.org NR 15 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD JUL PY 2007 VL 40 IS 1 BP 6 EP 19 DI 10.1016/j.commatsci.2006.10.017 PG 14 WC Materials Science, Multidisciplinary SC Materials Science GA 186JB UT WOS:000247773900002 ER PT J AU Rumsey, CL Schaeffler, NW Milanovic, IM Zaman, KBMQ AF Rumsey, C. L. Schaeffler, N. W. Milanovic, I. M. Zaman, K. B. M. Q. TI Time-accurate computations of isolated circular synthetic jets in crossflow SO COMPUTERS & FLUIDS LA English DT Article ID SHEAR-FLOW; TURBULENCE; MODELS AB Results from unsteady Reynolds-averaged Navier-Stokes computations are described for two different synthetic jet flows issuing into a turbulent boundary layer crossflow through a circular orifice. In one case the jet effect is mostly contained within the boundary layer, while in the other case the jet effect extends beyond the boundary layer edge. Both cases have momentum flux ratios less than 2. Several numerical parameters are investigated, and some lessons learned regarding the CFD methods for computing these types of flow fields are summarized. Results in both cases are compared to experiment. (C) 2006 Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Computat Aerosci Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Flow Phys & Control Branch, Hampton, VA 23681 USA. Univ Hartford, Dept Mech Engn, Hartford, CT 06117 USA. NASA, Glenn Res Ctr, Turbomachinery & Propuls Syst Div, Nozzle Branch, Cleveland, OH 44135 USA. RP Rumsey, CL (reprint author), NASA, Langley Res Ctr, Computat Aerosci Branch, Mail Stop 128, Hampton, VA 23681 USA. EM C.L.RUMSEY@NASA.GOV OI Milanovic, Ivana/0000-0002-9985-6014 NR 28 TC 14 Z9 14 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-7930 J9 COMPUT FLUIDS JI Comput. Fluids PD JUL PY 2007 VL 36 IS 6 BP 1092 EP 1105 DI 10.1016/j.compfluid.2006.09.002 PG 14 WC Computer Science, Interdisciplinary Applications; Mechanics SC Computer Science; Mechanics GA 168PY UT WOS:000246537700006 ER PT J AU Decyk, VK Norton, CD Gardner, HJ AF Decyk, Viktor K. Norton, Charles D. Gardner, Henry J. TI Why Fortran? SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Editorial Material C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Decyk, VK (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. EM decyk@physics.ucla.edu; Charles.D.NortonC@jpl.nasa.gov; Henry.Gardner@anu.edu.au NR 7 TC 4 Z9 4 U1 0 U2 2 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 2007 VL 9 IS 4 BP 68 EP 71 DI 10.1109/MCSE.2007.89 PG 4 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 181XR UT WOS:000247470200016 ER PT J AU Turon, A Davila, CG Camanho, PP Costa, J AF Turon, A. Davila, C. G. Camanho, P. P. Costa, J. TI An engineering solution for mesh size effects in the simulation of delamination using cohesive zone models SO ENGINEERING FRACTURE MECHANICS LA English DT Article DE delamination; fracture; cohesive elements ID CRACK-GROWTH; PROGRESSIVE DELAMINATION; DISLOCATION NUCLEATION; INTERLAMINAR FRACTURE; COMPOSITES; DAMAGE; SOLIDS; INTRALAMINAR; PROPAGATION; MECHANICS AB A methodology to determine the constitutive parameters for the simulation of progressive delamination is proposed. The procedure accounts for the size of a cohesive finite element and the length of the cohesive zone to ensure the correct dissipation of energy. In addition, a closed-form expression for estimating the minimum penalty stiffness necessary for the constitutive equation of a cohesive finite element is presented. It is shown that the resulting constitutive law allows the use of coarser finite element meshes than is usually admissible, which renders the analysis of large-scale progressive delamination problems computationally tractable. (C) 2006 Elsevier Ltd. All rights reserved. C1 Univ Porto, Fac Engn, DEMEGI, P-4200465 Oporto, Portugal. Univ Girona, Polytech Sch, AMADE, E-17071 Girona, Spain. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Camanho, PP (reprint author), Univ Porto, Fac Engn, DEMEGI, Rua Dr Roberto Frias, P-4200465 Oporto, Portugal. EM pcamanho@fe.up.pt RI Turon, Albert/C-6875-2008; Davila, Carlos/D-8559-2011; Camanho, Pedro /E-1666-2011; Costa, Josep/C-4941-2008; AMADE Research Group, AMADE/B-6537-2014; Balanzat, Josep Costa/C-1017-2014 OI Turon, Albert/0000-0002-2554-2653; Camanho, Pedro/0000-0003-0363-5207; Costa, Josep/0000-0002-7134-7146; AMADE Research Group, AMADE/0000-0002-5778-3291; NR 46 TC 344 Z9 385 U1 11 U2 107 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-7944 J9 ENG FRACT MECH JI Eng. Fract. Mech. PD JUL PY 2007 VL 74 IS 10 BP 1665 EP 1682 DI 10.1016/j.engfracmech.2006.08.025 PG 18 WC Mechanics SC Mechanics GA 173EN UT WOS:000246856400008 ER PT J AU Taylor, DL Nichols, RS Able, KW AF Taylor, David L. Nichols, Ryan S. Able, Kenneth W. TI Habitat selection and quality for multiple cohorts of young-of-the-year bluefish (Pomatomus saltatrix): Comparisons between estuarine and ocean beaches in southern New Jersey SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE bluefish; Pomatomus saltatrix; estuary; ocean beach; habitat; growth; cohort; otolith ID EARLY-LIFE-HISTORY; NEW-YORK BIGHT; FLOUNDER PSEUDOPLEURONECTES-AMERICANUS; SUMMER-SPAWNED BLUEFISH; JUVENILE BLUEFISH; OTOLITH MICROSTRUCTURE; CONTINENTAL-SHELF; ATLANTIC BIGHT; UNITED-STATES; GROWTH-RATES AB In this study, seasonal and annual variability in the use of estuarine and ocean beaches by young-of-the-year bluefish, Pomatonlus saltatrix, was evaluated by indices of abundance in coastal areas of southern New Jersey (1998-2000). Biological and physical factors measured at specific sites were correlated with bluefish abundance to determine the mechanisms underlying habitat selection. In addition, integrative and discrete indicators of bluefish growth were used to examine spatio-temporal dynamics in habitat quality and its effect on habitat selection by multiple cohorts of bluefish. Intra-annual recruitment to coastal areas of southern New Jersey was episodic, and resulted from the ingress of spring-spawned bluefish (hatch-date similar to April) to estuarine beaches in late May to early June, followed by the recruitment of summer-spawned fish (hatch-date similar to early July) to ocean beaches from July to October. Bluefish utilized estuarine and ocean beaches in a facultative manner that was responsive to dynamics in prey composition and temperature conditions. The recruitment and residency of bluefish in the estuary (19981999) and ocean beaches (1998), for example, was coincidental with the presence of the Atlantic silverside Menidia nienidia and bay anchovy Anchoa mitchilli, the principal prey species for bluefish occupying these respective habitat-types. Bluefish abundance in the estuary (2000) and ocean beaches (1999-2000) was also correlated with water temperature, with the greatest catches of juveniles coinciding with their optimal growth temperature (24 degrees C). Bluefish growth, estimated as the slope of age-length relationships and daily specific growth rates, equaled 1.27-2.63 mm fork length (FL) d- 1 and 3.8-8.7% body length increase d- 1, respectively. The growth of sagittal otoliths was also used as a proxy for changes in bluefish size during and shortly before their time of capture. Accordingly, otolith growth rates of summer-spawned bluefish were greater at ocean beaches relative to the estuary and were explained by the more suitable temperature conditions found at ocean beaches during the mid- to late summer. Notwithstanding the fast growth of oceanic summer-spawned bluefish, individuals spawned in the spring were still larger in absolute body size at the end of the summer growing season (similar to 240 and 50-200 mm FL for spring- and summer-spawned bluefish, respectively). The size discrepancy between spring- and summer-spawned bluefish at the onset of autumn migrations and during overwintering periods may account for the differential recruitment success of the respective cohorts. (c) 2007 Elsevier Ltd. All rights reserved. C1 Roger Williams Univ, Dept Marine Biol, Bristol, RI 02809 USA. Rutgers State Univ, Inst Marine & Coastal Sci, Marine Field Stn, Tuckerton, NJ 08087 USA. Pacific Isl Fisheries Sci Ctr, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA. RP Taylor, DL (reprint author), Roger Williams Univ, Dept Marine Biol, One Old Ferry Rd, Bristol, RI 02809 USA. EM dtaylor@rwu.edu NR 50 TC 21 Z9 21 U1 0 U2 6 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD JUL PY 2007 VL 73 IS 3-4 BP 667 EP 679 DI 10.1016/j.ecss.2007.03.007 PG 13 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 179HX UT WOS:000247281500028 ER PT J AU Keanini, RG Brown, AM AF Keanini, Russell G. Brown, Andrew M. TI Scale analysis and experimental observations of shock-induced turbulent boundary layer separation in nozzles SO EUROPEAN JOURNAL OF MECHANICS B-FLUIDS LA English DT Article DE shock-induced separation; compressible turbulent boundary layers ID COMPRESSION CORNER; MOTION AB Time average shock-induced boundary layer separation is investigated using scale analyses, analytical modeling, and experiments. While the study focuses on turbulent boundary layer separation in overexpanded rocket nozzles, many of the analyses presented apply to the broad family of free interaction, shock-separated flows in which the structure of the boundary layer-shock interaction zone is self-similar and independent of the shock generator. The scale analyses lead to two approximate expressions for the wall pressure ratio at separation; over a range of separation Mach numbers, both models provide reasonable predictions of observed separation pressure ratios. The second model, representing a refinement of the first, appears to provide a fairly general description of free interaction separation: the model approximately captures separation pressure ratios observed in supersonic flow over backward facing steps and in the case of overexpanded nozzle flow, provides predictions that are consistent with the free interaction model. Experiments are carried out in a sub-scale nozzle under overexpanded, cold-flow conditions. The principal observations are as follows: (i) For the range of separation Mach numbers investigated (5.0 <= M-i <= 5.4), nominal separation line locations can be predicted with reasonable accuracy using the classical generalized quasi-one-dimensional compressible flow model and an appropriate separation criterion. (ii) Over the same range of overexpanded flow conditions, the time-average pressure rise over the shock interaction zone can be accurately fit by the free interaction model. (C) 2006 Elsevier Masson SAS. All rights reserved. C1 Univ N Carolina, Dept Mech Engn & Engn Sci, Charlotte, NC 28223 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Keanini, RG (reprint author), Univ N Carolina, Dept Mech Engn & Engn Sci, Charlotte, NC 28223 USA. EM rkeanini@uncc.edu NR 38 TC 9 Z9 9 U1 0 U2 1 PU GAUTHIER-VILLARS/EDITIONS ELSEVIER PI PARIS PA 23 RUE LINOIS, 75015 PARIS, FRANCE SN 0997-7546 J9 EUR J MECH B-FLUID JI Eur. J. Mech. B-Fluids PD JUL-AUG PY 2007 VL 26 IS 4 BP 494 EP 510 DI 10.1016/j.euromechflu.2006.10.002 PG 17 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 171SY UT WOS:000246756900004 ER PT J AU Vasavada, S Sun, X Ishii, M Duval, W AF Vasavada, S. Sun, X. Ishii, M. Duval, W. TI Study of two-phase flows in reduced gravity using ground based experiments SO EXPERIMENTS IN FLUIDS LA English DT Article ID INTERFACIAL AREA TRANSPORT; GAS-LIQUID FLOW; MICROGRAVITY CONDITIONS; BUBBLY FLOW; SLUG FLOW; EQUATION; VELOCITY; SYSTEMS; TUBE AB Experimental studies have been carried out to support the development of a framework of the two-fluid model along with an interfacial area transport equation applicable to reduced gravity two-phase flows. The experimental study simulates the reduced gravity condition in ground based facilities by using two immiscible liquids of similar density namely, water as the continuous phase and Therminol 59 (R) as the dispersed phase. We have acquired a total of eleven data sets in the bubbly flow and bubbly to slug flow transition regimes. These flow conditions have area-averaged void (volume) fractions ranging from 3 to 30% and channel Reynolds number for the continuous phase between 2,900 and 8,800. Flow visualization has been performed and a flow regime map developed which is compared with relevant bubbly to slug flow regime transition criteria. The comparison shows that the transition boundary is well predicted by the criterion based on critical void fraction. The value of the critical void fraction at transition was experimentally determined to be approximately 25%. In addition, important two-phase flow local parameters, including the void fraction, interfacial area concentration, droplet number frequency and droplet velocity, have been acquired at two axial locations using state-of-the-art multi-sensor conductivity probe. The radial profiles and axial development of the two-phase flow parameters show that the coalescence mechanism is enhanced by either increasing the continuous or dispersed phase Reynolds number. Evidence of turbulence induced particle interaction mechanism is highlighted. The data presented in this paper clearly show the marked differences in terms of bubble (droplet) size, phase distribution and phase interaction in two-phase flow between normal and reduced gravity conditions. C1 Purdue Univ, Sch Nucl Engn, W Lafayette, IN 47907 USA. Ohio State Univ, Dept Mech Engn, Columbus, OH 43210 USA. NASA, Glenn Res Ctr, Fluid Phys & Transport Branch, Cleveland, OH 44135 USA. RP Vasavada, S (reprint author), Purdue Univ, Sch Nucl Engn, 400 Cent Dr, W Lafayette, IN 47907 USA. EM svasavad@purdue.edu RI Sun, Xiaodong/F-3752-2015 OI Sun, Xiaodong/0000-0002-9852-160X NR 43 TC 10 Z9 11 U1 1 U2 13 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0723-4864 J9 EXP FLUIDS JI Exp. Fluids PD JUL PY 2007 VL 43 IS 1 BP 53 EP 75 DI 10.1007/s00348-007-0321-3 PG 23 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 189DR UT WOS:000247970100005 ER PT J AU DeMartini, EE Uchiyama, JH Humphreys, RL Sampaga, JD Williams, HA AF DeMartini, Edward E. Uchiyama, James H. Humphreys, Robert L., Jr. Sampaga, Jeffrey D. Williams, Happy A. TI Age and growth of swordfish (Xiphias gladius) caught by the Hawaii-based pelagic longline fishery SO FISHERY BULLETIN LA English DT Article ID NORTH PACIFIC; FIN-SPINES; WATERS; TAIWAN AB We verified the age and growth of swordfish (Xiphias gladius) by comparing ages determined from annuli in fin ray sections with daily growth increments in otoliths. Growth of swordfish of exploitable sizes is described on the basis of annuli present in cross sections of the second ray of the first anal fins of 1292 specimens (60-260 cm eye-to-fork length, EFL) caught in the region of the Hawaii-based pelagic longline fishery. The position of the initial fin ray annulus of swordfish was verified for the first time with the use of scanning electron micrographs of presumed daily growth increments present in the otoliths of juveniles. Fish growth through age 7 was validated by marginal increment analysis. Faster growth of females was confirmed, and the standard von Bertalanffy growth model was identified as the most parsimonious for describing growth in length for fish greater than 60 cm EFL. The observed growth of three fish, a year-old in size when first caught and then recaptured from 364 to 1490 days later, is consistent with modeled growth for fish of this size range. Our novel approach to verifying age and growth should increase confidence in conducting an age-structured stock assessment for swordfish in the North Pacific Ocean. C1 NOAA, Natl Marine Fisheries Serv, Pacific Islands Fisheries Ctr, Honolulu, HI 96822 USA. RP DeMartini, EE (reprint author), NOAA, Natl Marine Fisheries Serv, Pacific Islands Fisheries Ctr, 2570 Dole Str, Honolulu, HI 96822 USA. EM Edward.Demartini@noaa.gov NR 30 TC 22 Z9 23 U1 2 U2 8 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 2007 VL 105 IS 3 BP 356 EP 367 PG 12 WC Fisheries SC Fisheries GA 205JD UT WOS:000249108900005 ER PT J AU Kouchinsky, A Bengtson, S Pavlov, V Runnegar, B Torssander, P Young, E Ziegler, K AF Kouchinsky, Artem Bengtson, Stefan Pavlov, Vladimir Runnegar, Bruce Torssander, Peter Young, Edward Ziegler, Karen TI Carbon isotope stratigraphy of the Precambrian-Cambrian Sukharikha River section, northwestern Siberian platform SO GEOLOGICAL MAGAZINE LA English DT Article DE Cambrian; carbon; isotope ratios; stratigraphy ID EARLY ANIMAL EVOLUTION; INTEGRATED CHRONOSTRATIGRAPHY; BOUNDARY BEDS; CHEMOSTRATIGRAPHY; BIOSTRATIGRAPHY; MOROCCO; RECORD; TIME; CONSTRAINTS; CALIBRATION AB A high-resolution carbon isotope profile through the uppermost Neoproterozoic-Lower Cambrian part of the Sukharikha section at the northwestern margin of the Siberian platform shows prominent secular oscillations of delta(13)C with peak-to-peak range of 6-10 parts per thousand. There are six minima, In-6n, and seven maxima 1p-7p, in the Sukharikha Formation and a rising trend of VC from the minimum In of - 8.6 parts per thousand to maximum 6p of + 6.4 parts per thousand. The trough In probably coincides with the isotopic minimum at the Precambrian-Cambrian boundary worldwide. Highly positive delta(13)C values of peaks 5p and 6p are typical of the upper portion of the Precambrian-Cambrian transitional beds just beneath the Tommotian Stage in Siberia. A second rising trend of VC is observed through the Kxasnoporog and lower Shumny formations. It consists of four excursions with four major maxima that can be correlated with Tommotian-Botomian peaks II, IV, V, and VII of the reference profile from the southeastern Siberian platform. According to the chemostratigraphic correlation, the first appearances of the index forms of archaeocyaths are earlier in the Sukharikha section than in the Lena-Aldan reuion. C1 Swedish Museum Nat Hist, Dept Palaeozool, SE-10405 Stockholm, Sweden. Inst Phys Earth, Moscow 123995, Russia. NASA, Ames Res Ctr, Astrobiol Inst, Moffett Field, CA 94035 USA. Stockholm Univ, Dept Geol & Geochem, SE-10691 Stockholm, Sweden. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. RP Kouchinsky, A (reprint author), Swedish Museum Nat Hist, Dept Palaeozool, Box 50007, SE-10405 Stockholm, Sweden. EM artem.kouchinsky@nrm.se OI Bengtson, Stefan/0000-0003-0206-5791 NR 40 TC 23 Z9 28 U1 3 U2 14 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0016-7568 J9 GEOL MAG JI Geol. Mag. PD JUL PY 2007 VL 144 IS 4 BP 609 EP 618 DI 10.1017/S0016756807003354 PG 10 WC Geosciences, Multidisciplinary SC Geology GA 199EL UT WOS:000248678900001 ER PT J AU Guest, B Guest, A Axen, G AF Guest, Bernard Guest, Alice Axen, Gary TI Late Tertiary tectonic evolution of northern Iran: A case for simple crustal folding SO GLOBAL AND PLANETARY CHANGE LA English DT Article; Proceedings Paper CT 2nd TOPO-EUROPE Workshop - Geoscience of Coupled Deep Earth-Surface Processes CY OCT 27-29, 2005 CL Heidelberg, GERMANY SP Planet Earth, European Sci Fdn, ISES, KTS DE lithospheric buckling or folding; fault localization; subduction initiation; basin inversion; Alborz; Iran; south Caspian basin ID SOUTH CASPIAN BASIN; CENTRAL ALBORZ MOUNTAINS; ACTIVE TECTONICS; STRIKE-SLIP; SURROUNDING REGIONS; TIBETAN PLATEAU; BLACK-SEA; LITHOSPHERE; DEFORMATION; TRANSITION AB Here we present a crustal folding or buckling mechanism to explain the rootless 3-5 km high Alborz Mountains in northern Iran as well as -10 km of Late Miocene to recent subsidence in the south Caspian basin and -3-6 km of subsidence in the central Iranian basin in the context of the middle Miocene to recent Arabia-Eurasia collision. A key element of the mechanism is the presence of lateral and vertical lithospheric strength contrasts between the north Iranian continental and south Caspian oceanic crusts: when compression from the collision is applied across the region, the strong south Caspian oceanic crust, buried under >I 0 km of premiddle Miocene sediment, interacts with the bottom of the mechanically strong continental upper crust of northern Iran, resulting in upward buckling of the continental crust and downward buckling of the oceanic crust. We test this mechanism using a finite-element numerical model with a Maxwell theology and obtain results that are consistent with the geological and geophysical observations. The observations compiled here and the model results demonstrate the potential for using this region as a natural laboratory for studying the early stages of continent-oceanic collision, including processes like basin inversion, fault localization and, potentially, subduction initiation. (C) 2007 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. RP Guest, B (reprint author), Univ Munich, Dept Geog & Environm Sci, Geol Sect, Marchioninistr 15, Munich, Germany. EM b.guest@iaag.geo.uni-muenchen.de OI Guest, Bernard/0000-0002-1130-4857 NR 75 TC 36 Z9 40 U1 2 U2 6 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 2007 VL 58 IS 1-4 BP 435 EP + DI 10.1016/j.gloplacha.2007.02.014 PG 17 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 191OM UT WOS:000248140700017 ER PT J AU Prince, SD Wessels, KJ Tucker, CJ Nicholson, SE AF Prince, Stephen D. Wessels, Konrad J. Tucker, Compton J. Nicholson, Sharon E. TI Desertification in the Sahel: a reinterpretation of a reinterpretation SO GLOBAL CHANGE BIOLOGY LA English DT Article DE Africa; AVHRR; degradation; desertification; net primary production; rainfall; rain-use efficiency; Sahel; satellite; semiarid ID RAINFALL VARIABILITY; VEGETATION DYNAMICS; USE EFFICIENCY; AFRICAN SAHEL; NDVI DATA; GRASSLAND; DEGRADATION; CLIMATE; PRECIPITATION; RANGELAND AB In semiarid regions the ratio of annual net primary production to precipitation, rain-use efficiency (RUE), has been used as an index of desertification. In a recent publication (Hein & de Ridder, 2006) it was proposed that an incorrect understanding of the relationship between RUE and rainfall has led to a misinterpretation of the satellite record of desertification in the African Sahel. Here, we examine this suggestion and show that, contrary to Hein and de Ridder's statement, satellite studies of Sahelian RUE have reported increases, decreases, and constant values since 1981. Furthermore, we find that data do not support their proposal that RUE increases with rainfall, even in nondegraded areas. Hence we reject their corollary, that constant RUE is prima facie evidence of desertification. The fundamental difficulty with the use of RUE for detection of desertification remains, that is the difficulty of estimation of the RUE for nondegraded land at a regional scale. C1 Univ Maryland, Dept Geog, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Biospher Sci, Greenbelt, MD 20771 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. RP Prince, SD (reprint author), Univ Maryland, Dept Geog, Rm 2181 LeFrak Hall, College Pk, MD 20742 USA. EM sprince@geog.umd.edu NR 36 TC 85 Z9 90 U1 3 U2 57 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1354-1013 J9 GLOBAL CHANGE BIOL JI Glob. Change Biol. PD JUL PY 2007 VL 13 IS 7 BP 1308 EP 1313 DI 10.1111/j.1365-2486.2007.01356.x PG 6 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 202ZV UT WOS:000248945800002 ER PT J AU Stutte, G Yorio, N Richards, J Edney, S Wheeler, R AF Stutte, Gary Yorio, Neil Richards, Jeffrey Edney, Sharon Wheeler, Raymond TI Radish growth and development is sustained under hypobaric pressures SO HORTSCIENCE LA English DT Meeting Abstract C1 Gen Dynam Corp, Kennedy Space Ctr, FL USA. NASA, Biomed Operat & Res Off, Kennedy Space Ctr, FL 32899 USA. EM w.stutte@nasa.gov; c.yorio@nasa.gov; jeffrey.t.richards@nasa.gov; l.edney@nasa.gov; m.wheeler@nasa.gov NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER SOC HORTICULTURAL SCIENCE PI ALEXANDRIA PA 113 S WEST ST, STE 200, ALEXANDRIA, VA 22314-2851 USA SN 0018-5345 J9 HORTSCIENCE JI Hortscience PD JUL PY 2007 VL 42 IS 4 SU S BP 875 EP 875 PG 1 WC Horticulture SC Agriculture GA 184UT UT WOS:000247668800098 ER PT J AU Coustenis, A Achterberg, RK Conrath, BJ Jennings, DE Marten, A Gautier, D Nixon, CA Flasar, FM Teanby, NA Bezard, B Samuelson, RE Carlson, RC Lellouch, E Bjoraker, GL Romani, PN Taylor, FW Irwin, PGJ Fouchet, T Hubert, A Orton, GS Kunde, VG Vinatier, S Mondellini, J Abbas, MM Courtin, R AF Coustenis, Athena Achterberg, Richard K. Conrath, Barney J. Jennings, Donald E. Marten, Andre Gautier, Daniel Nixon, Conor A. Flasar, F. Michael Teanby, Nick A. Bezard, Bruno Samuelson, Robert E. Carlson, Ronald C. Lellouch, Emmanuel Bjoraker, Gordon L. Romani, Paul N. Taylor, Fred W. Irwin, Patrick G. J. Fouchet, Thierry Hubert, Augustin Orton, Glenn S. Kunde, Virgil G. Vinatier, Sandrine Mondellini, Jacqueline Abbas, Mian M. Courtin, Regis TI The composition of Titan's stratosphere from Cassini/CIRS mid-infrared spectra SO ICARUS LA English DT Article DE Titan; Satellites, atmospheres; infrared observations ID VOYAGER INFRARED OBSERVATIONS; ADAPTIVE OPTICS; ATMOSPHERIC COMPOSITION; HETERODYNE OBSERVATIONS; VERTICAL DISTRIBUTIONS; LATITUDINAL VARIATIONS; SATURNIAN SYSTEM; THERMAL EMISSION; SOLAR-SYSTEM; D/H RATIO AB We have analyzed data recorded by the Composite Infrared Spectrometer (CIRS) aboard the Cassini spacecraft during the Titan flybys T0-T10 (July 2004-January 2006). The spectra characterize various regions on Titan from 70 degrees S to 70 degrees N with a variety of emission angles. We study the molecular signatures observed in the mid-infrared CIRS detector arrays (FP3 and FP4, covering roughly the 600-1500 cm(-1) spectral range with apodized resolutions of 2.54 or 0.53 cm(-1)). The composite spectrum shows several molecular signatures: hydrocarbons, nitrites and CO2. A firm detection of benzene (C6H6) is provided by CIRS at levels of about 3.5 x 10(-9) around 70 degrees N. We have used temperature profiles retrieved from the inversion of the emission observed in the methane nu(4) band at 1304 cm(-1) and a line-by-line radiative transfer code to infer the abundances of the trace constituents and some of their isotopes in Titan's stratosphere. No longitudinal variations were found for these gases. Little or no change is observed generally in their abundances from the south to the equator. On the other hand, meridional variations retrieved for these trace constituents from the equator to the North ranged from almost zero (no or very little meridional variations) for C2H2, C2H6, C3H8, C2H4 and CO2 to a significant enhancement at high northern (early winter) latitudes for HCN, HC3N, C4H2, C3H4 and C6H6. For the more important increases in the northern latitudes, the transition occurs roughly between 30 and 50 degrees north latitude, depending on the molecule. Note however that the very high-northern latitude results from tours TB-T10 bear large uncertainties due to few available data and problems with latitude smearing effects. The observed variations are consistent with some, but not all, of the predictions from dynamical-photochemical models. Constraints are set on the vertical distribution of C2H2, found to be compatible with 2-D equatorial predictions by global circulation models. The D/H ratio in the methane on Titan has been determined from the CH3D band at 1156 cm(-1) and found to be 1.17(-0.28)(+0.23) x 10(-4). Implications of this deuterium enrichment, with respect to the protosolar abundance on the origin of Titan, are discussed. We compare our results with values retrieved by Voyager IRIS observations taken in 1980, as well as with more recent (1997) disk-averaged Infrared Space Observatory (ISO) results and with the latest Cassini-Huygens inferences from other instruments in an attempt to better comprehend the physical phenomena on Titan. (c) 2007 Elsevier Inc. All rights reserved. C1 Observ Paris, LESIA, F-92195 Meudon, France. NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD 20771 USA. Cornell Univ, CRSR, Ithaca, NY 14853 USA. NASA, Goddard Space Flight Ctr Code 693, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Univ Oxford, Clarendon Lab, Dept Phys, AOPP, Oxford OX1 3PU, England. Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Coustenis, A (reprint author), Observ Paris, LESIA, LESIA Bat 18,5 Pl Jules Janssen, F-92195 Meudon, France. EM athena.coustenis@obspm.fr 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; Fouchet, Thierry/C-6374-2017; OI Nixon, Conor/0000-0001-9540-9121; Fouchet, Thierry/0000-0001-9040-8285; Teanby, Nicholas/0000-0003-3108-5775; Irwin, Patrick/0000-0002-6772-384X NR 91 TC 237 Z9 236 U1 4 U2 33 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 2007 VL 189 IS 1 BP 35 EP 62 DI 10.1016/j.icarus.2006.12.022 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182GH UT WOS:000247492600003 ER PT J AU Samuelson, RE Smith, MD Achterberg, RK Pearl, JC AF Samuelson, Robert E. Smith, Michael D. Achterberg, Richard K. Pearl, John C. TI Cassini CIRS update on stratospheric ices at Titan's winter pole SO ICARUS LA English DT Article DE Titan; atmospheres, composition; ices; IR spectroscopy ID ATMOSPHERE; SPECTRA; CLOUDS; CONSTITUENTS; TEMPERATURES; PAIRS; MARS; HC3N AB A strong, broad spectral emission feature at 85 degrees N latitude centered at 221 cm(-1) remains unidentified after candidate ices of H2O and pure crystalline CH3CH2CN are unambiguously ruled out. A much shallower weak emission feature starts at 160 cm(-1) and blends into the strong feature at similar to 190 cm(-1). This feature is consistent with one formed by an HCN ice cloud composed of <= 5 mu m radius particles that resides in the lower stratosphere somewhere below an altitude of 160 km. Titan's stratospheric aerosol appears to have a spectral emission feature at about 148 cm(-1). The aerosol abundance at 85 degrees N is about a factor 2.2 greater than at 55 degrees S. (c) 2007 Elsevier Inc. All rights reserved. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr Code 693, Greenbelt, MD 20771 USA. RP Samuelson, RE (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM bob.samuelson@ssedmail.gsfc.nasa.gov RI Smith, Michael/C-8875-2012 NR 35 TC 19 Z9 19 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 EI 1090-2643 J9 ICARUS JI Icarus PD JUL PY 2007 VL 189 IS 1 BP 63 EP 71 DI 10.1016/j.icarus.2007.02.005 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182GH UT WOS:000247492600004 ER PT J AU Sabelhaus, PA Decker, J AF Sabelhaus, Philip A. Decker, John TI James Webb Space Telescope: Project overview SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB The James Webb Space Telescope (JWST) project at the NASA, Goddard Space Flight Center (GSFC) is responsible for the development, launch, flight, and science operations for the telescope. The project is in Phase B with its launch scheduled for no earlier than June 2013. The project is a partnership among NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The JWST mission team is fully in place, including major ESA and CSA subcontractors. This provides an overview of the planned JWST science, current architecture focusing on the instrumentation, and mission status, including technology developments, and risks. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20711 USA. RP Sabelhaus, PA (reprint author), NASA, Goddard Space Flight Ctr, Code 443, Greenbelt, MD 20711 USA. NR 0 TC 1 Z9 1 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD JUL PY 2007 VL 22 IS 7 BP 3 EP 13 DI 10.1109/MAES.2007.4285974 PG 11 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 199LH UT WOS:000248696800001 ER PT J AU Gaskell, R Husman, LE Collier, JB Chen, RL AF Gaskell, Robert Husman, Laura Ekroot Collier, James B. Chen, Richard L. TI Synthetic environments for simulated missions SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB Synthetic environments offer Space Flight projects an opportunity to perform rapid, comprehensive, and rigorous modeling of the critical elements of a mission in order to compute quantitative measures of design performance, associated risk, and actual mission utility value. Significantly, these studies can be performed early in the mission cycle. These synthetic terrains are generated on parallel, high-performance computers and served to remote simulations at near-interactive speeds. The terrain creation uses a realistic sequence of physical phenomena such as cratering and dusting with parametric control of features such as surface roughness and rock density. Terrain resolution may be arbitrary but typically ranges from 0.01 to 10 meters. The terrain server has been used for two rover simulations, one using the actual Sojourner autonomy flight code, and the other a more general algorithm. Monte Carlo studies of rover designs interacting with synthetic environments were executed in parallel to quickly compute performance statistics and risk estimates. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gaskell, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD JUL PY 2007 VL 22 IS 7 BP 14 EP 20 DI 10.1109/MAES.2007.4285976 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 199LH UT WOS:000248696800002 ER PT J AU Randolph, J Eremenko, A Miyake, R Dirling, R AF Randolph, James Eremenko, Alexander Miyake, Robert Dirling, Raymond, Jr. TI To fly to the sun: Solar Probe mission & technology challenges SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB To fly close to the sun (to a perihelion of 4 solar radii) represents many unique challenges to a mission and spacecraft design. The Solar Probe design is a result of over two decades of studies that have allowed the evolution of both the mission and trajectory design, as well as the spacecraft configurations. During these studies some of the most significant design challenges have been the trajectory design, the spacecraft shield design, the spacecraft configuration, the telecommunications near perihelion, science instrument accommodations, and minimizing mission cost. This latter challenge (minimum cost) permeates all other design issues suggesting specific solutions consistent with this constraint. This presents the evolution and rationale that have taken place to arrive at the current design for this challenging mission. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Sci Applicat Int Corp, Mclean, VA 22102 USA. RP Randolph, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 16 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD JUL PY 2007 VL 22 IS 7 BP 21 EP 28 DI 10.1109/MAES.2007.4285987 PG 24 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 199LH UT WOS:000248696800003 ER PT J AU Backes, P Collins, C AF Backes, Paul Collins, Curtis TI Sample caching concept for planetary missions SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article ID MARS AB A Sample Caching Subsystem (SCS) concept that provides transfer and storage of core and soil samples for planetary missions has been developed. The SCS could be carried on a rover and a rover arm-mounted coring tool could acquire samples and deposit the samples in the SCS. The SCS would transfer the samples into a sample container, with each sample in a separate sleeve. Important to the SCS design is the ability to seal each sleeve, and the sample with it, to isolate it from other samples and from the external environment. Sealing of the samples will allow for maintaining the integrity of organic materials over many years thereby allowing the samples to be analyzed in later missions or after a return trip to Earth. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Backes, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD JUL PY 2007 VL 22 IS 7 BP 29 EP 34 DI 10.1109/MAES.2007.4285988 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 199LH UT WOS:000248696800006 ER PT J AU Amitai, E Nystuen, JA Anagnostou, EN Anagnostou, MN AF Amitai, E. Nystuen, J. A. Anagnostou, E. N. Anagnostou, M. N. TI Comparison of deep underwater measurements and radar observations of rainfall SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS LA English DT Article DE Ionian Sea; radar measurements; radar scattering; rain; rainfall rate; sound pressure level; underwater acoustical measurements ID CLASSIFICATION; SOUND AB Deep-water acoustical measurements of rainfall are compared to high-resolution ground radar observations for the first time. The measurements of underwater ambient sound were made from a subsurface mooring near Methoni, Greece, in 2004. The acoustical measurements were at 60-, 200-, 1000-, and 2000-m depths. Simultaneous ground-based polarimetric X-band radar observations were made over the acoustic mooring. Comparisons show acoustic detection of rain events and storm structure that are in agreement with the radar observations. Results from a comparison between the underwater sound pressure level at different depths and the observed radar reflectivities are presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. George Mason Univ, Coll Sci, Fairfax, VA 22030 USA. Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA. Univ Connecticut, Dept Civil & Environm Engn, Storrs, CT 06269 USA. RP Amitai, E (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 12 TC 5 Z9 5 U1 0 U2 5 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 2007 VL 4 IS 3 BP 406 EP 410 DI 10.1109/LGRS.2007.895681 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 191QX UT WOS:000248147200016 ER PT J AU Chiu, JC Marshak, A Wiscombe, WJ Valencia, SC Welton, EJ AF Chiu, J. Christine Marshak, Alexander Wiscombe, Warren J. Valencia, Sandra C. Welton, E. Judd TI Cloud optical depth retrievals from solar background "signals" of micropulse lidars SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS LA English DT Article DE cloud; cloud-aerosol interactions; lidar; remote sensing; zenith radiance ID AEROSOL; INSTRUMENTS; NETWORK AB Pulsed lidars are commonly used to retrieve vertical distributions of cloud and aerosol layers. It is widely believed that lidar cloud retrievals (other than cloud base altitude) are limited to optically thin clouds. Here, we demonstrate that lidars can retrieve optical depths of thick clouds using solar background light as a signal, rather than (as now) merely a noise to be subtracted. Validations against other instruments show that retrieved cloud optical depths agree within 10%-15% for overcast stratus and broken clouds. In fact, for broken cloud situations, one can retrieve not only the aerosol properties in clear-sky periods using lidar signals, but also the optical depth of thick clouds in cloudy periods using solar background signals. This indicates that, in general, it may be possible to retrieve both aerosol and cloud properties using a single lidar. Thus, lidar observations have great untapped potential to study interactions between clouds and aerosols. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Chiu, JC (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. EM cchiu@climate.gsfc.nasa.gov; Alexander.Marshak@nasa.gov; Warren.J.Wiscombe@nasa.gov; s.c.valencia@lse.ac.uk; Ellsworth.J.Welton@nasa.gov RI Welton, Ellsworth/A-8362-2012; Marshak, Alexander/D-5671-2012; Wiscombe, Warren/D-4665-2012; Chiu, Christine/E-5649-2013 OI Wiscombe, Warren/0000-0001-6844-9849; Chiu, Christine/0000-0002-8951-6913 NR 17 TC 6 Z9 6 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1545-598X J9 IEEE GEOSCI REMOTE S JI IEEE Geosci. Remote Sens. Lett. PD JUL PY 2007 VL 4 IS 3 BP 456 EP 460 DI 10.1109/LGRS.2007.896722 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 191QX UT WOS:000248147200026 ER PT J AU Chander, G Markham, BL Barsi, JA AF Chander, Gyanesh Markham, Brian L. Barsi, Julia A. TI Revised Landsat-5 thematic mapper radiometric calibration SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS LA English DT Article DE bias; calibration; characterization; gain; Landsat-5 (L5); Libya; lookup table (LUT); National Land Archive Production System (NLAPS); offset; radiance; reflectance; relative spectral response (RSR); spectral bands; Thematic Mapper (TM) AB Effective April 2, 2007, the radiometric calibration of Landsat-5 (L5) Thematic Mapper (TM) data that are processed and distributed by the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS) will be updated. The lifetime gain model that was implemented on May 5, 2003, for the reflective bands (1-5, 7) will be replaced by a new lifetime radiometric-calibration curve that is derived from the instrument's response to pseudoinvariant desert sites and from cross calibration with the Landsat-7 (L7) Enhanced TM Plus (ETM+). Although this calibration update applies to all archived and future L5 TM data, the principal improvements in the calibration are for the data acquired during the first eight years of the mission (1984-1991), where the changes in the instrument-gain values are as much as 15%. The radiometric scaling coefficients for bands 1 and 2 for approximately the first eight years of the mission have also been changed. Users will need to apply these new coefficients to convert the calibrated data product digital numbers to radiance. The scaling coefficients for the other bands have not changed. C1 US Geol Survey, Ctr Earth Resources Observat & Sci, Sci Applicat Int Corp, Sioux Falls, SD 57198 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP Chander, G (reprint author), US Geol Survey, Ctr Earth Resources Observat & Sci, Sci Applicat Int Corp, Sioux Falls, SD 57198 USA. EM gchander@usgs.gov RI Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 6 TC 112 Z9 115 U1 3 U2 14 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 2007 VL 4 IS 3 BP 490 EP 494 DI 10.1109/LGRS.2007.898285 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 191QX UT WOS:000248147200033 ER PT J AU Gaier, T Samoska, L Fung, A Deal, WR Radisic, V Mei, XB Yoshida, W Liu, PH Uyeda, J Barsky, M Lai, R AF Gaier, T. Samoska, L. Fung, A. Deal, W. R. Radisic, V. Mei, X. B. Yoshida, W. Liu, P. H. Uyeda, J. Barsky, M. Lai, R. TI Measurement of a 270 GHz low noise amplifier with 7.5 dB noise figure SO IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS LA English DT Article DE low noise amplifier (LNA); MM-wave; monolithic microwave integrated circuit (MMIC); noise measurement ID MMIC AMPLIFIER; TECHNOLOGY AB We describe the measurement of the noise of a 270-GHz low noise amplifier using wafer-probe techniques. The measurement includes deembedding to the coplanar waveguide input of the chip. The noise was measured at a variety of bias conditions and found to be a minimum of 7.5 dB. The gain of the chip is measured to be 11.4 dB, consistent with s-parameter measurements of the same device. This is the highest frequency measurement of noise of a monolithic microwave integrated circuit amplifier and the only known on-wafer measurement of noise at this frequency. The, measurement demonstrates that wafer probe techniques developed at lower frequencies can be applied to circuits at submillimeter wavelengths. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Northrop Grumman Corp, Redondo Beach, CA 90278 USA. RP Gaier, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM todd.gaier@jpl.nasa.gov NR 9 TC 20 Z9 21 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1531-1309 J9 IEEE MICROW WIREL CO JI IEEE Microw. Wirel. Compon. Lett. PD JUL PY 2007 VL 17 IS 7 BP 546 EP 548 DI 10.1109/LMWC.2007.899324 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 187ZR UT WOS:000247888500027 ER PT J AU Reising, SC Marzano, FS Nioku, EG Westwater, ER AF Reising, Steven C. Marzano, Frank S. Nioku, Eni G. Westwater, Ed R. CA Ctr Excellence CETEMPS TI Foreword to the special issue on the 9th specialist meeting on microwave radiometry and remote sensing applications (MicroRad '06) SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Editorial Material C1 Colorado State Univ, Dept Elect & Comp Engn, Ft Collins, CO 80523 USA. Univ Roma La Sapienza, Dept Elect Engn, I-00184 Rome, Italy. Univ Aquila, Ctr Excellence CETEMPS, I-67040 Laquila, Italy. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Colorado, Dept Elect & Comp Engn, NOAA CU Ctr Environm Technol, Boulder, CO 80309 USA. RP Reising, SC (reprint author), Colorado State Univ, Dept Elect & Comp Engn, Ft Collins, CO 80523 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUL PY 2007 VL 45 IS 7 BP 1903 EP 1906 DI 10.1109/TGRS.2007.900318 PN 1 PG 4 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 186NC UT WOS:000247784400001 ER PT J AU Brown, ST Desai, S Lu, W Tanner, AB AF Brown, Shannon T. Desai, Shailen Lu, Wenwen Tanner, Alan B. TI On the long-term stability of microwave radiometers using noise diodes for calibration SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 9th Specialist Meeting on Microwave Radiometry and Remote Sensing Applications (MicroRad 2006) CY FEB 28-MAR 03, 2006 CL San Juan, PR SP IEEE DE advanced water vapor radiometer (AWVR); calibration; Jason microwave radiometer (JMR); Jason-1; microwave radiometer; noise diode (ND); path delay (PD) AB Results are presented from the long-term monitoring and calibration of the National Aeronautics and Space Administration Jason Microwave Radiometer (JMR) on the Jason-1 ocean altimetry satellite and the ground-based Advanced Water Vapor Radiometers (AWVRs) developed for the Cassini Gravity Wave Experiment. Both radiometers retrieve the wet tropospheric path delay (PD) of the atmosphere and use internal noise diodes (NDs) for gain calibration. The JMR is the first radiometer to be flown in space that uses NDs for calibration. External calibration techniques are used to derive a time series of ND brightness for both instruments that is greater than four years. For the JMR, an optimal estimator is used to find the set of calibration coefficients that minimize the root-mean-square difference between the JMR brightness temperatures and the on-Earth hot and cold references. For the AWVR, continuous tip curves are used to derive the ND brightness. For the JMR and AWVR, both of which contain three redundant NDs per channel, it was observed that some NDs were very stable, whereas others experienced jumps and drifts iii their effective brightness. Over the four-year time period, the ND stability ranged from 0.2% to 3% among the diodes for both instruments. The presented recalibration methodology demonstrates that long-term calibration stability can be achieved with frequent recalibration of the diodes using external calibration techniques. The JMR PD drift compared to ground truth over the four years since the launch was reduced from 3.9 to -0.01 mm/year with the recalibrated ND time series. The JMR brightness temperature calibration stability is estimated to be 0.25 K over ten days. C1 CALTECH, Jet Prop Lab, NASA, Microwave Adv Syst Sect, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, NASA, Orbit & Radio Metr Syst Grp, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, NASA, Ground Based Microwave Applicat Grp, Pasadena, CA 91109 USA. RP Brown, ST (reprint author), CALTECH, Jet Prop Lab, NASA, Microwave Adv Syst Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Shannon.T.Brown@jpl.nasa.gov NR 17 TC 20 Z9 22 U1 1 U2 4 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 JUL PY 2007 VL 45 IS 7 BP 1908 EP 1920 DI 10.1109/TGRS.2006.888098 PN 1 PG 13 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 186NC UT WOS:000247784400002 ER PT J AU De Amici, G Layton, RA Brown, ST AF De Amici, Giovanni Layton, Ryan A. Brown, Shannon T. TI Stabilization of the brightness temperature of a calibration warm load for spaceborne microwave radiometers SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 9th Specialist Meeting on Microwave Radiometry and Remote Sensing Applications (MicroRad 2006) CY FEB 28-MAR 03, 2006 CL San Juan, PR SP IEEE DE Calibration; microwave; radiometry AB We present the results of a study that shows that a simple design modification is sufficient to avoid a major shortcoming in the layout of external warm loads commonly used in the calibration of spaceborne microwave radiometers. The modification consists of placing a layer of Plastazote, a polyethylene foam, over the opening of the warm load enclosure. The foam is transparent at micrometer and millimeter wavelengths, is opaque in the infrared and visible, and isolates the warm load from the environment, keeping the temperature of the radiometric warm load constant. The proposed solution can be easily implemented and is suitable even for retrofitting on instruments that have already been built but not yet launched, and the material presents no obvious shortcomings that could prevent its intended application in space. C1 Northrop Grumman Space Technol, Redondo Beach, CA 90278 USA. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. Aerosp Corp, El Segundo, CA 90245 USA. RP De Amici, G (reprint author), Northrop Grumman Space Technol, Redondo Beach, CA 90278 USA. NR 20 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUL PY 2007 VL 45 IS 7 BP 1921 EP 1927 DI 10.1109/TGRS.2007.888283 PN 1 PG 7 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 186NC UT WOS:000247784400003 ER PT J AU Tanner, AB Wilson, WJ Lambrigsten, BH Dinardo, SJ Brown, ST Kangaslahti, PP Gaier, TC Ruf, CS Gross, SM Lim, BH Musko, SB Rogacki, SA Piepmeier, JR AF Tanner, Alan B. Wilson, William J. Lambrigsten, Bjorn H. Dinardo, Steve J. Brown, Shannon T. Kangaslahti, Pekka P. Gaier, Todd C. Ruf, Christopher S. Gross, Steven M. Lim, Boon H. Musko, Stephen B. Rogacki, Steven A. Piepmeier, Jeff R. TI Initial results of the geostationary synthetic thinned array radiometer (GeoSTAR) demonstrator instrument SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 9th Specialist Meeting on Microwave Radiometry and Remote Sensing Applications (MicroRad 2006) CY FEB 28-MAR 03, 2006 CL San Juan, PR SP IEEE DE interferometry; microwave imaging; microwave; radiometry; remote sensing ID INTERFEROMETRIC RADIOMETERS; APERTURE; IMPACT AB The design, error budget, and preliminary test results of a 50-56-GHz synthetic aperture radiometer demonstration system are presented. The instrument consists of a fixed 24-element array of correlation interferometers and is capable of producing calibrated images with 1 degrees spatial resolution within a 17 degrees wide field of view. This system has been built to demonstrate a performance and a design which can be scaled to a much larger geostationary Earth imager. As a baseline, such a system would consist of about 300 elements and would be capable of providing contiguous full hemispheric images of the Earth with 1 K of radiometric precision and 50-km spatial resolution. An error budget is developed around this goal and then tested with the. demonstrator system. Errors are categorized as either scaling (i.e., complex gain) or additive (noise and bias) errors. Sensitivity to gain and/or phase error is generally proportional to the magnitude of the expected visibility, which is high only in the shortest baselines of the array, based on model simulations of the Earth as viewed from geostationary Earth orbit. Requirements range from approximately 0.5% and 0.3 degrees of amplitude and phase uncertainty, respectively, for the closest spacings at the center of the array, to about 4% and 2.5 degrees for the majority of the array. The latter requirements are demonstrated with our instrument using relatively simple references and antenna models, and by relying on the intrinsic stability and efficiency of the system. The 0.5% requirement (for the short baselines) is met by measuring the detailed spatial response (e.g., on the antenna range) and by using an internal noise diode reference to stabilize the response. This result suggests a hybrid image synthesis algorithm in which long baselines are processed by a fast Fourier transform and the short baselines are processed by a more precise (G-matrix) algorithm which can handle small anomalies among antenna and receiver, responses. Visibility biases and other additive errors must be below about 1.5 mK on average, regardless of baseline. The bias requirement is largely met with a phase-shifting scheme applied to the local oscillator distribution of our demonstration system. Low mutual coupling among the horn antennas of our design is also critical to minimize the biases caused by crosstalk of receiver noise. Performance is validated by a three-way comparison between interference fringes measured on the antenna range, solar transit observations, and the system model. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Univ Michigan, Ann Arbor, MI 48109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Tanner, AB (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. EM Alan.b.tanner@jpl.nasa.gov RI Ruf, Christopher/I-9463-2012 NR 10 TC 47 Z9 56 U1 0 U2 2 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 JUL PY 2007 VL 45 IS 7 BP 1947 EP 1957 DI 10.1109/TGRS.2007.894060 PN 1 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 186NC UT WOS:000247784400006 ER PT J AU Torres, F Tanner, AB Brown, ST Lambrigsten, BH AF Torres, Francese Tanner, Alan B. Brown, Shannon T. Lambrigsten, Bjorn H. TI Analysis of array distortion in a microwave interferometric radiometer: Application to the GeoSTAR project SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 9th Specialist Meeting on Microwave Radiometry and Remote Sensing Applications (MicroRad 2006) CY FEB 28-MAR 03, 2006 CL San Juan, PR SP IEEE DE array; distortion; error analysis; interferometry; radiometry; remote sensing ID 2-DIMENSIONAL APERTURE SYNTHESIS; RESOLUTION AB The Geostationary Synthetic Thinned Array Radiometer represents a promising new approach to microwave atmospheric sounding from geostationary orbit based on passive interferometry. Distortion due to mechanical or thermal constraints produces a displacement of the ideal antenna positions in the array that causes sampling errors. In this paper, the impact of array distortion on radiometric error is analyzed in detail so as to identify the dominant sources of error. A preliminary analysis showing that array distortion can be well corrected by means of an external phase reference is also presented. C1 Univ Politecn Cataluna, Dept Signal Theory & Commun, Barcelona 08030, Spain. CALTECH, Jet Prop Lab, NASA, Microwave Advance Syst Sect, Pasadena, CA 91109 USA. RP Torres, F (reprint author), Univ Politecn Cataluna, Dept Signal Theory & Commun, Barcelona 08030, Spain. EM xtorres@tsc.upc.edu; Alan.b.tanner@jpl.nasa.gov; Shannon.T.Brown@jpl.nasa.gov RI Torres, Francesc/D-7587-2013 OI Torres, Francesc/0000-0003-1160-6350 NR 15 TC 10 Z9 11 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUL PY 2007 VL 45 IS 7 BP 1958 EP 1966 DI 10.1109/TGRS.2007.898093 PN 1 PG 9 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 186NC UT WOS:000247784400007 ER PT J AU Jones, LA Kimball, JS McDonald, KC Chan, STK Njoku, EG Oechel, WC AF Jones, Lucas A. Kimball, John S. McDonald, Kyle C. Chan, Steven Tsz K. Njoku, Eni G. Oechel, Walter C. TI Satellite microwave remote sensing of boreal and arctic soil temperatures from AMSR-E SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 9th Specialist Meeting on Microwave Radiometry and Remote Sensing Applications (MicroRad 2006) CY FEB 28-MAR 03, 2006 CL San Juan, PR SP IEEE DE Advanced Microwave Scanning Radiometer; for the Earth Observing System (AMSR-E); Arctic tundra; boreal forest; microwave radiometry; satellite remote sensing; soil temperature ID LAND-SURFACE-TEMPERATURE; RADIOFREQUENCY INTERFERENCE; BRIGHTNESS TEMPERATURES; ECOSYSTEM RESPIRATION; NORTHERN ALASKA; VEGETATION; RETRIEVAL; MOISTURE; LANDSCAPE; EXCHANGE AB Methods are developed and evaluated to retrieve surface soil temperature information for the Advanced Microwave Scanning Radiometer on Earth. Observing System for seven boreal forest and Arctic tundra biophysical monitoring sites across Alaska and Northern Canada. A multiple-band iterative radiative transfer process-based method producing dynamic vegetation and snow cover correction quantities and an empirical multiple regression method using several frequencies are employed. The seasonal pattern of microwave emission and relative accuracy of the soil temperature retrievals are influenced strongly by landscape properties, including the presence of open water, vegetation type and seasonal phenology, snow cover, and freeze-thaw transitions. The retrieval of soil temperature is similar for the two methods with an overall root-mean-square error of 3.1-3.9 K during summer thawed conditions, with a larger error occurring in winter during periods of dynamic snow cover and freeze-thaw state. These results indicate that at high latitudes, the influence of the atmosphere may be less important than that of surface conditions in determining the relative accuracy of the estimated soil temperature. Impacts of surface conditions on surface emissivity, observed brightness temperature, and estimated soil temperature are discussed. C1 Univ Montana, Coll Forestry & Conservat, Numer Terradynam Simulat Grp, Missoula, MT 59812 USA. Univ Montana, Flathead Lake Biol Stn, Polson, MT 59860 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. San Diego State Univ, Global Change Res Grp, San Diego, CA 92182 USA. RP Jones, LA (reprint author), Univ Montana, Coll Forestry & Conservat, Numer Terradynam Simulat Grp, Missoula, MT 59812 USA. EM lucas@ntsg.umt.edu; johnk@ntsg.umt.edu; kyle.mcdonald@jpl.nasa.gov; Steven.K.Chan@jpl.nasa.gov; Eni.G.Njoku@jpl.nasa.gov; occhel@sunstroke.sdsu.edu RI Oechel, Walter/F-9361-2010; Xie, Xingmei/G-7311-2011 OI Oechel, Walter/0000-0002-3504-026X; NR 51 TC 33 Z9 34 U1 4 U2 18 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0196-2892 EI 1558-0644 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUL PY 2007 VL 45 IS 7 BP 2004 EP 2018 DI 10.1109/TGRS.2007.898436 PN 1 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 186NC UT WOS:000247784400012 ER PT J AU Le Vine, DA Lagerloef, GSE Colomb, FR Yueh, SH Pellerano, FA AF Le Vine, David M. Lagerloef, Gary S. E. Colomb, Fernando Raul Yueh, Simon H. Pellerano, Fernando A. TI Aquarius: An instrument to monitor sea surface salinity from space SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 9th Specialist Meeting on Microwave Radiometry and Remote Sensing Applications (MicroRad 2006) CY FEB 28-MAR 03, 2006 CL San Juan, PR SP IEEE DE microwave radiometry; microwave remote sensing; ocean salinity; scatterometer ID OCEAN SALINITY; L-BAND; SOIL-MOISTURE; RETRIEVAL; LAYER AB Aquarius is a combined passive/active L-band microwave instrument that is being developed to map the salinity field at the surface of the ocean from space. The data will support studies of the coupling between ocean circulation, global water cycle, and climate. Aquarius is part of the Aquarius/Satelite de Aplicaciones Cientificas-D mission, which is a partnership between the U.S. (National Aeronautics and Space Administration) and Argentina (Comision Nacional de Actividades Espaciales). The primary science objective of this mission is to monitor the seasonal and interannual variation of the large-scale features of the surface salinity field in the open ocean with a spatial resolution of 150 km and a retrieval accuracy of 0.2 psu globally on a monthly basis. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Earth & Space Res, Seattle, WA 98102 USA. Comis Nacl Act Espaciales, RA-1063 Buenos Aires, DF, Argentina. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Le Vine, DA (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM david.m.levine@nasa.gov NR 23 TC 135 Z9 136 U1 1 U2 26 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0196-2892 EI 1558-0644 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUL PY 2007 VL 45 IS 7 BP 2040 EP 2050 DI 10.1109/TGRS.2007.898092 PN 1 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 186NC UT WOS:000247784400015 ER PT J AU Dinnat, EP Le Vine, DM AF Dinnat, Emmanuel P. Le Vine, David M. TI Effects of the antenna aperture on remote sensing of sea surface salinity at L-band SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 9th Specialist Meeting on Microwave Radiometry and Remote Sensing Applications (MicroRad 2006) CY FEB 28-MAR 03, 2006 CL San Juan, PR SP IEEE DE antenna radiation patterns; microwave radiometry; remote sensing; sea surface AB Remote sensing of sea surface salinity can be performed by means of microwave radiometry at L-band, but it requires high radiometric accuracy (e.g., on the order of 0.1 K). Since the variability of salinity in the open ocean exhibits large spatial scales and long temporal scales, it is possible to use antennas with large footprints and averaging to meet this goal. However, antennas with large footprints introduce other problems such as variations of the incidence angle and direction of the polarization vectors over the footprint. Examples of these effects are computed here using antennas that are representative of those that will be flown on the Aquarius/SAC-D mission being developed for remote sensing of salinity from space. It is shown that the antenna temperature (i.e., integrated over the antenna pattern) is biased relative to the value at boresight. In part, this is due to change in incidence angles across the field of view. Polarization mixing, because of the variations of the local plane of incidence across the footprint, also induces bias (peculiarly for the third Stokes parameter). Finally, large antenna footprints limit how close to land measurements can be made. C1 NASA, Goddard Space Flight Ctr, Instrumentat Sci Branch, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA. RP Dinnat, EP (reprint author), NASA, Goddard Space Flight Ctr, Instrumentat Sci Branch, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA. EM dinnat@neptune.gsfc.nasa.gov RI Dinnat, Emmanuel/D-7064-2012 OI Dinnat, Emmanuel/0000-0001-9003-1182 NR 12 TC 12 Z9 12 U1 0 U2 2 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 JUL PY 2007 VL 45 IS 7 BP 2051 EP 2060 DI 10.1109/TGRS.2007.890807 PN 1 PG 10 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 186NC UT WOS:000247784400016 ER PT J AU Sun, JQ Xiong, XX Barnes, WL Guenther, B AF Sun, Jun-Qiang Xiong, Xiaoxiong Barnes, William L. Guenther, Bruce TI MODIS reflective solar bands on-orbit lunar calibration SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE lunar irradiance; Moderate Resolution Imaging Spectroradiometer (MODIS); moon; radiometric stability; reflective solar bands (RSBs); response versus scan angle (RVS) ID RADIOMETRIC CALIBRATION; PHOTOMETRIC FUNCTION; MOON; STABILITY; SURFACE AB The Moderate Resolution Imaging Spectroradiometer (MODIS) Protoflight Model on-board the Terra spacecraft and the MODIS Flight Model 1 on-board the Aqua spacecraft were launched on December 18, 1999 and May 4, 2002, respectively. They view the moon through the space view (SV) port approximately once a month to monitor the long-term radiometric stability of their reflective solar bands (RSBs). The lunar irradiance observed by MODIS depends on the viewing geometry. Algorithms were developed to select lunar views such that these geometric effects are minimized. In each MODIS lunar observation, the moon can be viewed in multiple scans. The lunar irradiance of a MODIS RSB can be derived from the response of all detectors of a spectral band in one scan which fully covers the moon, from that of one detector in multiple scans or from the response of all detectors in multiple scans. Based on lunar observations, a set of coefficients is defined and derived to trend MODIS system response degradation at the angle of incidence (AOI) of its SV port. It is shown that the degradation is both wavelength and mirror side dependent. Since launch, Terra and Aqua MODIS band 8 (412 nm) mirror side one have degraded 36% and 17%, respectively, at the AOI of the SV. A comparison between the lunar coefficients and those derived from the MODIS on-board solar diffuser (SD) calibrations shows that the response change of the MODIS RSB is both AOI and time dependent. Time-dependent response versus scan angle (RVS) lookup tables derived from lunar views, SD calibration, and Earth-view observations have been used to maintain the quality of the LIB data for both the Terra and Aqua MODIS RSB. The corrections provided by the RVS in the Terra and Aqua MODIS data from the 412-nm band are as large as 14 % and 6.2 %, respectively., C1 Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Sci Explorat Directorate, Greenbelt, MD 20771 USA. Univ Maryland, Baltimore, MD 21250 USA. RP Sun, JQ (reprint author), Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NR 18 TC 97 Z9 98 U1 2 U2 11 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 JUL PY 2007 VL 45 IS 7 BP 2383 EP 2393 DI 10.1109/TGRS.2007.896541 PN 2 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 186NE UT WOS:000247784600022 ER PT J AU Pettiford, C Dasgupta, S Lou, J Yoon, SD Sun, NX AF Pettiford, Carl Dasgupta, Saumitro Lou, Jin Yoon, Soack D. Sun, N. X. TI Bias field effects on microwave frequency behavior of PZT/YIG magnetoelectric bilayer SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article DE ferrimagnetic resonance (FMR); magnetoelectric (ME) composites; microwave ME devices ID LAMINATE COMPOSITES; MAGNETIC-FIELD AB Magnetoelectric behavior of a yittrium iron garnet (YIG)/zirconate titanate (PZT) magnetoelectric bilayer composite was studied over 1-7 GHz under different bias magnetic fields and electric fields by using a broadband air-gap microstrip with the PZT/YIG loaded in the air gap. Electrostatically induced ferrimagnetic resonance (FMR) frequency shifts of the YIG/PZT bilayer composite were studied. The FMR frequency shift was negligible at bias fields when the YIG was not saturated. After saturation, the FMR frequency increased nearly linearly from 15 MHz at a bias field of 100 Oe to 30 MHz at 1200 Oe and dropped suddenly at a field of 1300 Oe to about 20 MHz. This nonlinear bias magnetic field dependence was due to magnetic domain activities when the YIG was not saturated and due to the interference between the uniform mode and other magnetostatic spin waves after saturation. An electrostatically tunable band-reject filter device was demonstrated which has a peak attenuation of greater than 50 dB, 40 dB rejection band of 10 MHz, and pass band insertion loss of < 5 dB at similar to 4.6 GHz. C1 Northeastern Univ, Dept Elect & Comp Engn, CM3IC, Boston, MA 02115 USA. Northeastern Univ, NASA, CAMMP, Boston, MA 02115 USA. RP Pettiford, C (reprint author), Northeastern Univ, Dept Elect & Comp Engn, CM3IC, Boston, MA 02115 USA. EM pettiford.c@neu.edu RI Sun, Nian Xiang/F-9590-2010; Sun, Nian-xiang/G-8330-2011; Lou, Jing/B-6762-2009 OI Sun, Nian Xiang/0000-0002-3120-0094; NR 15 TC 54 Z9 56 U1 1 U2 23 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD JUL PY 2007 VL 43 IS 7 BP 3343 EP 3345 DI 10.1109/TMAG.2007.893790 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 184MF UT WOS:000247645100030 ER PT J AU Heintz, RA AF Heintz, Ron A. TI Chronic Exposure to Polynuclear Aromatic Hydrocarbons in Natal Habitats Leads to Decreased Equilibrium Size, Growth, and Stability of Pink Salmon Populations SO INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT LA English DT Article DE Polynuclear aromatic hydrocarbons; Population; Density dependence; Salmon; Toxicity AB The immediate and delayed effects of embryonic exposure to low levels of polynuclear aromatic hydrocarbons (PAHs) have been shown to reduce survival to maturity by 50% in exposed pink salmon populations. This suggests that chronically exposed populations could be extirpated over relatively few generations, but the effect of density dependence on extirpation rate is unknown. This study examines the interaction of PAH effects and randomly varying density dependence on a simulated population. The simulation derives from 70 years of observations made on a single pink salmon population and toxicity studies involving a hatchery population in the same watershed. Results from simulations involving exposure of 100% of the population to effects consistent with an aqueous PAH concentration of 18 nL/L indicate an 80% decrease in population productivity and an 11% probability of extinction after 35 generations. In contrast, population growth rate declined by only 5%. Further decreases in survival relative to that of observed PAH effects rapidly increase the probability of extinction. Data from these simulations demonstrate that, at low levels of exposure, density dependence can compensate for reduced population size and buffer the population against extinction. However, if equilibrium size is depressed sufficiently, random environmental variation overcomes the buffering effect of density dependence and extinction probability increases. These data demonstrate that extinction probability and population size are more sensitive measures of population effects than growth rate for wild populations regulated by density dependence. C1 [Heintz, Ron A.] NOAA, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, 11305 Glacier Hwy, Juneau, AK 99801 USA. RP Heintz, RA (reprint author), NOAA, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, 11305 Glacier Hwy, Juneau, AK 99801 USA. EM ron.heintz@noaa.gov FU Exxon Valdez Oil Spill Trustee Council [98476] FX This study was completed under funding provided by the Exxon Valdez Oil Spill Trustee Council (restoration study 98476). Thanks are extended to J. Pella, M. Sigler, and T. Quinn for their guidance in model development. NR 45 TC 18 Z9 18 U1 0 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1551-3777 EI 1551-3793 J9 INTEGR ENVIRON ASSES JI Integr. Environ. Assess. Manag. PD JUL PY 2007 VL 3 IS 3 BP 351 EP 363 DI 10.1002/ieam.5630030306 PG 13 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA V43WZ UT WOS:000209712800007 PM 17695108 ER PT J AU Bozzolo, G Mosca, HO Noebe, RD AF Bozzolo, Guillermo Mosca, Hugo O. Noebe, Ronald D. TI Phase structure and site preference behavior of ternary alloying additions to PdTi and PtTi shape-memory alloys SO INTERMETALLICS LA English DT Article DE ternary alloy systems; alloy design; site occupancy; simulations, atomistic; shape-memory alloy applications ID MECHANICAL-PROPERTIES; FE; AL AB The phase structure and concentration dependence of the lattice parameter and energy of formation of ternary Pd-Ti-X and Pt-Ti-X alloys for a large number of ternary alloying additions X (X = Na, Mg, Al, Si, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Ag, Cd, Hf, Ta, W, Re, Os, Ir) are investigated with an atomistic modeling approach. In addition, a detailed description of the site preference behavior of such additions showing that the elements can be grouped according to their absolute preference for a specific site, regardless of concentration, or preference for available sites in the deficient sublattice is provided. (C) 2006 Elsevier Ltd. All rights reserved. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Comis Nacl Energia Atom, UA Fis, RA-1429 Buenos Aires, DF, Argentina. RP Bozzolo, G (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. EM GuillermoBozzolo@oai.org NR 27 TC 11 Z9 11 U1 1 U2 13 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD JUL PY 2007 VL 15 IS 7 BP 901 EP 911 DI 10.1016/j.intermet.2006.10.049 PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 181CR UT WOS:000247415000009 ER PT J AU Zhang, H Mudawar, I Hasan, MM AF Zhang, Hui Mudawar, Issam Hasan, Mohammad M. TI Photographic study of high-flux subcooled flow boiling and critical heat flux SO INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER LA English DT Article DE critical heat flux; flow boiling; subcooled boiling ID CHF MECHANISM; PREDICTION; MODEL; LONG; WALL AB This study examines both high-flux flow boiling and critical heat flux (CHF) under highly subcooled conditions using FC-72 as working fluid. Experiments were performed in a horizontal flow channel that was heated along its bottom wall. High-speed video imaging and photomicrographic techniques were used to capture interfacial features and reveal the sequence of events leading to CHF. At about 80% of CHF, bubbles coalesced into oblong vapor patches while sliding along the heated wall. These patches grew in size with increasing heat flux, eventually evolving into a fairly continuous vapor layer that permitted liquid contact with the wall only in the wave troughs between vapor patches. CHF was triggered when this liquid contact was finally halted. These findings prove that the CHF mechanism for subcooled flow boiling is consistent with the interfacial lift-off mechanism proposed previously for saturated flow boiling. (C) 2007 Elsevier Ltd. All rights reserved. C1 Purdue Univ, Sch Mech Engn, Boiling & Two Phase Flow Lab, W Lafayette, IN 47907 USA. NASA, Glenn es Ctr, Cleveland, OH 44135 USA. RP Mudawar, I (reprint author), Purdue Univ, Sch Mech Engn, Boiling & Two Phase Flow Lab, W Lafayette, IN 47907 USA. EM mudawar@ecn.purdue.edu NR 14 TC 15 Z9 15 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0735-1933 J9 INT COMMUN HEAT MASS JI Int. Commun. Heat Mass Transf. PD JUL PY 2007 VL 34 IS 6 BP 653 EP 660 DI 10.1016/j.icheatmasstransfer.2007.01.014 PG 8 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA 189LE UT WOS:000247989600001 ER PT J AU Mourikis, AI Trawny, N Roumeliotis, SI Helmick, DM Matthies, L AF Mourikis, Anastasios I. Trawny, Nikolas Roumeliotis, Stergios I. Helmick, Daniel M. Matthies, Larry TI Autonomous stair climbing for tracked vehicles SO INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH LA English DT Article DE stair climbing; autonomous robots; inertial sensing; attitude estimation; computer vision ID CAMERA CALIBRATION AB In this paper, on algorithm for autonomous stair climbing with a tracked vehicle is presented. The proposed method achieves robust performance under real-world conditions, without assuming prior knowledge of the stair geometry, the dynamics of the vehicle's interaction with the stair surface, or lighting conditions. The approach relies on fast and accurate estimation of the robot's heading and its position relative to the stair boundaries. An extended Kalman filter is used for quaternion-based attitude estimation, fusing rotational velocity measurements from a 3-axial gyroscope, and measurements of the stair edges acquired with an onboard camera. A two-tiered controller, comprised of a centering- and a heading-control module, utilizes the estimates to guide the robot rapidly, safely, and accurately upstairs. Both the theoretical analysis and implementation of the algorithm are presented in detail, and extensive experimental results demonstrating the algorithm's performance are described. C1 Univ Minnesota, Dept Comp Sci & Engn, Minneapolis, MN 55455 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Mourikis, AI (reprint author), Univ Minnesota, Dept Comp Sci & Engn, Minneapolis, MN 55455 USA. EM mourikis@cs.umn.edu; trawny@cs.umn.edu; stergios@cs.umn.edu; dhelmick@robotics.jpl.nasa.gov; lhm@telerobotics.jpl.nasa.gov NR 29 TC 41 Z9 43 U1 2 U2 14 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0278-3649 EI 1741-3176 J9 INT J ROBOT RES JI Int. J. Robot. Res. PD JUL PY 2007 VL 26 IS 7 BP 737 EP 758 DI 10.1177/0278364907080423 PG 22 WC Robotics SC Robotics GA 188IZ UT WOS:000247914900007 ER PT J AU Rainey, FA Ferreira, M Nobre, MF Ray, K Bagaley, D Earl, AM Battista, JR Gomez-Silva, B McKay, CP da Costa, MS AF Rainey, Fred A. Ferreira, Margarida Nobre, M. Fernanda Ray, Keren Bagaley, Danielle Earl, Ashlee M. Battista, John R. Gomez-Silva, Benito McKay, Christopher P. da Costa, Milton S. TI Deinococcus peraridilitoris sp nov., isolated from a coastal desert SO INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY LA English DT Article ID RADIATION-RESISTANT; DEOXYRIBONUCLEIC-ACID; GENUS THERMUS; FAM-NOV; BACTERIA; TEMPERATURE; PROPOSAL; STRAINS AB Three ionizing-radiation-resistant bacterial strains (designated KR-196, KR-198 and KR-200(T)) were isolated from a sample of arid soil collected from a coastal desert in Chile. The soil sample was irradiated before serial dilution plating was performed using one-tenth-strength plate count agar. Phylogenetic analysis of the 16S rRNA gene sequences showed these organisms to represent a novel species of the genus Deinococcus, having sequence similarities of 87.3-90.8 % with respect to recognized Deinococcus species. Strains KR-196, KR-198 and KR-200(T) were aerobic and showed optimum growth at 30 degrees C and pH 6.5-8.0. The major respiratory menaquinone was MK-8. The predominant fatty acids in these strains were 16 : 1 omega 7c, 16 : 0,15 : 1 omega 6c, 17 : 0 and 18:0. The DNA G+C content of strain KR-200(T) was 63.9 mol%. Strains KR-196, KR-198 and KR-200(T) were found to be resistant to > 10 kGy gamma radiation. On the basis of the phylogenetic, chemotaxonomic and phenotypic data, strain KR-200(T) represents a novel species of the genus Deinococcus, for which the name Deinococcus peraridilitoris sp. nov. is proposed. The type strain is KR-200(T) (=LMG 22246(T) = Clp 109416(T)). C1 Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA. Univ Coimbra, Dept Bioquim, P-3004517 Coimbra, Portugal. Univ Coimbra, Ctr Neurociencias & Biol Celular, P-3004517 Coimbra, Portugal. Univ Coimbra, Dept Zool, P-3004517 Coimbra, Portugal. Univ Antofagasta, Fac Ciencias Salud, Inst Desierto & Unidad Bioquim, Antofagasta, Chile. NASA Ames Res Ctr, Space Sci Div, Moffett Field, CA 94035 USA. RP Rainey, FA (reprint author), Louisiana State Univ, Dept Biol Sci, 202 Life Sci Bldg, Baton Rouge, LA 70803 USA. EM frainey@lsu.edu RI Rainey, Fred/C-8767-2013; OI Rainey, Fred/0000-0001-9129-6844; Earl, Ashlee/0000-0001-7857-9145; da Costa, Milton/0000-0003-4027-4412 NR 20 TC 18 Z9 20 U1 0 U2 5 PU SOC GENERAL MICROBIOLOGY PI READING PA MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING RG7 1AG, BERKS, ENGLAND SN 1466-5026 J9 INT J SYST EVOL MICR JI Int. J. Syst. Evol. Microbiol. PD JUL PY 2007 VL 57 BP 1408 EP 1412 DI 10.1099/ijs.0.64956-0 PN 7 PG 5 WC Microbiology SC Microbiology GA 195SR UT WOS:000248432500008 PM 17625166 ER PT J AU Pikuta, EV Marsic, D Itoh, T Bej, AK Tang, J Whitman, WB Ng, JD Garriott, OK Hoover, RB AF Pikuta, Elena V. Marsic, Damien Itoh, Takashi Bej, Asim K. Tang, Jane Whitman, William B. Ng, Joseph D. Garriott, Owen K. Hoover, Richard B. TI Thermococcus thioreducens sp nov., a novel hyperthermophilic, obligately sulfur-reducing archaeon from a deep-sea hydrothermal vent SO INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY LA English DT Article ID THERMOPHILIC ARCHAEA; SEQUENCE ALIGNMENT; WESTERN SIBERIA; OIL-RESERVOIR; MONO LAKE; ARCHAEBACTERIUM; CALIFORNIA; REPRESENTS; REDUCTION; POSITION AB A hyperthermophilic, sulfur-reducing, organo-heterotrophic archaeon, strain OGL-20P(T), was isolated from 'black smoker' chimney material from the Rainbow hydrothermal vent site on the Mid-Atlantic Ridge (36.2 degrees N, 33.9 degrees W). The cells of strain OGL-20P(T) have an irregular coccoid shape and are motile with a single flagellum. Growth was observed within a pH range of 5.0-8.5 (optimum pH 7.0), an NaCl concentration range of 1-5% (w/v) (optimum 3%) and a temperature range of 55-94 degrees C (optimum 83-85 degrees C). The novel isolate is strictly anaerobic and obligately dependent upon elemental sulfur as an electron acceptor, but it does not reduce sulfate, sulfite, thiosulfate, Fe(III) or nitrate. Proteolysis products (peptone, bacto-tryptone, Casamino acids and yeast extract) are utilized as substrates during sulfur reduction. Strain OGL-20P(T) is resistant to ampicillin, chloramphenicol, kanamycin and gentamicin, but sensitive to tetracycline and rifampicin. The G + C content of the DNA is 52.9 mol%. The 16S rRNA gene sequence analysis revealed that strain OGL-20P(T) is closely related to Thermococcus coalescens and related species, but no significant homology by DNA-DNA hybridization was observed between those species and the new isolate. On the basis of physiological and molecular properties of the new isolate, we conclude that strain OGL-20P(T) represents a new separate species within the genus Thermococcus, for which we propose the name Thermococcus thioreducens sp. nov. The type strain is OGL-20P(T) (=JCM 12859(T) =DSM 14981(T) =ATCC BAA-394(T)). C1 NASA, NSSTC, Astrobiol Lab, Huntsville, AL 35805 USA. Univ Alabama, Struct Biol Lab, Dept Biol Sci, Huntsville, AL 35899 USA. RIKEN, BioResource Ctr, Japan Collect Microorganisms, Wako, Saitama 3510198, Japan. Univ Alabama, Dept Biol, Birmingham, AL 35294 USA. USDA, Monitoring Programs Off, Manassas, VA 20110 USA. Univ Georgia, Dept Microbiol, Athens, GA 30602 USA. UAH, Dept Biol Sci, Huntsville, AL 35899 USA. RP Pikuta, EV (reprint author), NASA, NSSTC, Astrobiol Lab, VP62,320 Sparkman Dr, Huntsville, AL 35805 USA. EM elenapikuta@hotmail.com RI Marsic, Damien/A-1087-2009 OI Marsic, Damien/0000-0003-0847-8095 NR 41 TC 25 Z9 28 U1 0 U2 7 PU SOC GENERAL MICROBIOLOGY PI READING PA MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING RG7 1AG, BERKS, ENGLAND SN 1466-5026 J9 INT J SYST EVOL MICR JI Int. J. Syst. Evol. Microbiol. PD JUL PY 2007 VL 57 BP 1612 EP 1618 DI 10.1099/ijs.0.65057-0 PN 7 PG 7 WC Microbiology SC Microbiology GA 195SR UT WOS:000248432500046 PM 17625204 ER PT J AU Balint, TS Kolawa, EA Cutts, JA AF Balint, Tibor S. Kolawa, Elizabeth A. Cutts, James A. TI Mitigating extreme environments for in-situ venus and jupiter missions SO JBIS-JOURNAL OF THE BRITISH INTERPLANETARY SOCIETY LA English DT Article; Proceedings Paper CT 57th International Astronautical Congress CY OCT 02-06, 2006 CL Valencia, SPAIN DE extreme environments; technology; Jupiter; Venus; NASA AB In response to the recommendations by the National Research Council (NRC), NASA's Solar System Exploration (SSE) Roadmap identified the in-situ exploration of Venus and Jupiter as high priority science objectives. For Jupiter, deep entry probes are recommended, which would descend to similar to 250 km-measured from the 1 bar pressure depth. At this level the pressure would correspond to similar to 100 bar and the temperature would reach similar to 500 degrees C. Similarly, at the surface of Venus the temperature and pressure conditions are similar to 460 degrees C and similar to 90 bar. Lifetime of the Jupiter probes during descent can be measured in hours, while in-situ operations at and near the surface of Venus are envisioned over weeks or months. In this paper we discuss technologies, which share commonalities in mitigating these extreme conditions over proposed mission lifetimes, specifically focusing on pressure and temperature environments. Pressure vessel designs are evaluated from the current State of Practice (SoP) to advanced concepts proposed for next decade missions and beyond. Thermal designs, both active and passive, are also addressed for the two target destinations. In addition, we briefly discuss other enabling technologies, such as high temperature electronics and power storage. It is expected that the findings from,these assessments would help NASA with identifying future technology investment areas, and in turn enable or enhance planned SSE missions, while reducing mission cost and risk. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Balint, TS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 301-170U, Pasadena, CA 91109 USA. EM tibor.balint@jpl.nasa.gov NR 11 TC 2 Z9 2 U1 0 U2 1 PU BRITISH INTERPLANETARY SOC PI LONDON PA 27-29 S LAMBETH RD, LONDON SW8 1SZ, ENGLAND SN 0007-084X J9 JBIS-J BRIT INTERPLA JI JBIS-J. Br. Interplanet. Soc. PD JUL PY 2007 VL 60 IS 7 BP 238 EP 248 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Engineering; Astronomy & Astrophysics; Geology GA 179RW UT WOS:000247308800001 ER PT J AU Balakrishnan, AV Iliff, KW AF Balakrishnan, A. V. Iliff, K. W. TI Continuum aerolastic model for inviscid subsonic bending-torsion wing flutter SO JOURNAL OF AEROSPACE ENGINEERING LA English DT Article ID SELF-STRAINING ACTUATORS; AEROELASTICITY AB A full continuum aeroelastic model for bending-torsion dynamics of a slender high- aspect-ratio wing in inviscid subsonic airflow is developed avoiding finite element or Pade approximations. The structure model is the classical cantilever model of Goland. The aerodynamics is simplified to the two-dimensional typical section theory. Stability is discussed in the Laplace domain leading to the calculation of the aeroelastic modes, the stability curve, and a precise definition of flutter speed, as well as an explicit formula for divergence speed. The flutter speed is shown to be monotonic decreasing as M increases for small k (normalized complex frequency); if a mode flutters at M=0 then it flutters for every M>0 excepting M=1. A time-domain state space model is developed requiring the language of abstract functional analysis in the form of a "convolution-evolution" equation in a Hilbert space. The time domain model for M=0 differs radically from 0 < M <= 1. It helps clarify the nature of the aeroelastic modes and flutter instability. The state space model can be used for control design including self-straining actuators. C1 Univ Calif Los Angeles, Flight Syst Res Ctr, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA. NASA Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. RP Balakrishnan, AV (reprint author), Univ Calif Los Angeles, Flight Syst Res Ctr, Box 951594, Los Angeles, CA 90095 USA. NR 15 TC 3 Z9 3 U1 0 U2 3 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 2007 VL 20 IS 3 BP 152 EP 164 DI 10.1061/(ASCE)0893-1321(2007)20:3(152) PG 13 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA 188KA UT WOS:000247917600003 ER PT J AU Schultz, MR Wilkie, WK Bryan, RG AF Schultz, Marc R. Wilkie, W. Keats Bryan, Robert G. TI Investigation of self-resetting active multistable laminates SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 46th Structures, Structural Dynamics and Materials Conference/1st AIAA Multidisciplinary Design Optimization Specialist Conference CY APR 18-21, 2005 CL Austin, TX SP AIAA, ASME, ASCE, AHS, ASC ID ROOM-TEMPERATURE SHAPES; CURED SHAPE; COMPOSITES AB Elastically multistable structures, that is, structures possessing more than one elastically stable equilibrium configuration, are particularly attractive for advanced shape changing (morphing) aircraft applications because no, control effort is required to maintain the structural shape in any specific stable equilibrium. For example, thin, unsymmetric, fiber-reinforced composite laminates (e.g., [0/90](Tau)) can have multiple equilibrium shapes, and such laminates can be changed from one stable shape to another by a simple snap-through action. Furthermore, previous work by the first author with others demonstrated the use of a planar piezocomposite actuator to snap a bistable laminate from one equilibrium shape to another, but not back again. Such a self-resetting capability is desirable in many practical applications. The present paper describes analytical and experimental efforts to model and demonstrate self-resetting, piezoelectrically controlled, multistable laminates., The work is based on a two-ply, [0/90](Tau) graphite-epoxy laminate that is sandwiched between two piezocomposite actuators. A simplified analytical model of the structure was developed to fine-tune the design of an experimental test article and correlate with results from testing. The simplified model captures the global response of the experimental device and predicts self-resetting actuation. Differences between the analytical and experimental results are identified, and possible reasons for these differences are explored. C1 Composite Technol Dev Inc, Lafayette, CO 80026 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Schultz, MR (reprint author), Composite Technol Dev Inc, Lafayette, CO 80026 USA. NR 25 TC 8 Z9 8 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 2007 VL 44 IS 4 BP 1069 EP 1076 DI 10.2514/1.17404 PG 8 WC Engineering, Aerospace SC Engineering GA 198LV UT WOS:000248630500003 ER PT J AU Landman, D Simpson, J Vicroy, D Parker, P AF Landman, Drew Simpson, Jim Vicroy, Dan Parker, Peter TI Response surface methods for efficient complex aircraft configuration aerodynamic characterization SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA 44th Aerospace Sciences Meeting and Exhibit CY JAN 09-12, 2006 CL Reno, NV SP AIAA AB A response surface methodology approach to wind-tunnel testing of aircraft with complex configurations is being investigated at the Langley full-scale tunnel as part of a series of tests using design of experiments. An exploratory study was conducted using response surface methodology and a 5% scale blended-wing-body model in an effort to efficiently characterize aerodynamic behavior as a function of attitude and multiple control surface inputs. This paper provides a direct comparison of the design of experiments/response surface methodology and one factor at a time methods for a low-speed wind-tunnel test of a blended-wing-body aircraft configuration with 11 actuated control surfaces. A modified fractional factorial design, augmented with center points and axial points, produced regression models for the characteristic aerodynamic forces and moments over a representative design space as a function of model attitude and control surface inputs. Model adequacy and uncertainty levels were described using robust statistical methods inherent to the response surface methodology practice. Experimental goals included the capture of fundamental stability and control data for simulation models and comparisons to baseline data from recent one factor at a time tests. Optimization is demonstrated for control surface allocation for a desired response. A discussion of highlights and problems associated with the test is included. C1 Old Dominion Univ, Norfolk, VA 23529 USA. Florida State Univ, Tallahassee, FL 32310 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Landman, D (reprint author), Old Dominion Univ, Norfolk, VA 23529 USA. NR 13 TC 11 Z9 12 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JUL-AUG PY 2007 VL 44 IS 4 BP 1189 EP 1195 DI 10.2514/1.24810 PG 7 WC Engineering, Aerospace SC Engineering GA 198LV UT WOS:000248630500015 ER PT J AU Shige, S Takayabu, YN Tao, WK Shie, CL AF Shige, Shoichi Takayabu, Yukari N. Tao, Wei-Kuo Shie, Chung-Lin TI Spectral retrieval of latent heating profiles from TRMM PR data. Part II: Algorithm improvement and heating estimates over Tropical Ocean regions SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY LA English DT Article ID MEASURING MISSION TRMM; CLOUD-RESOLVING MODEL; PACIFIC WARM POOL; SOUTH CHINA SEA; SCALE WAVE DISTURBANCES; TOGA COARE CONVECTION; PRECIPITATION RADAR; MOISTURE BUDGETS; WESTERN PACIFIC; VERTICAL STRUCTURE AB The spectral latent heating (SLH) algorithm was developed for the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) in Part I of this study. The method uses PR information [precipitationtop height (PTH), precipitation rates at the surface and melting level, and rain type] to select heating profiles from lookup tables. Heating-profile lookup tables for the three rain types - convective, shallow stratiform, and anvil rain (deep stratiform with a melting level) - were derived from numerical simulations of tropical cloud systems from the Tropical Ocean and Global Atmosphere Coupled Ocean - Atmosphere Response Experiment (TOGA COARE) utilizing a cloud-resolving model (CRM). To assess its global application to TRMM PR data, the universality of the lookup tables from the TOGA COARE simulations is examined in this paper. Heating profiles are reconstructed from CRM-simulated parameters (i.e., PTH, precipitation rates at the surface and melting level, and rain type) and are compared with the true CRM-simulated heating profiles, which are computed directly by the model thermodynamic equation. CRM-simulated data from the Global Atmospheric Research Program Atlantic Tropical Experiment ( GATE), South China Sea Monsoon Experiment (SCSMEX), and Kwajalein Experiment (KWAJEX) are used as a consistency check. The consistency check reveals discrepancies between the SLH-reconstructed and Goddard Cumulus Ensemble ( GCE)- simulated heating above the melting level in the convective region and at the melting level in the stratiform region that are attributable to the TOGA COARE table. Discrepancies in the convective region are due to differences in the vertical distribution of deep convective heating due to the relative importance of liquid and ice water processes, which varies from case to case. Discrepancies in the stratiform region are due to differences in the level separating upper-level heating and lower-level cooling. Based on these results, improvements were made to the SLH algorithm. Convective heating retrieval is now separated into upper-level heating due to ice processes and lower-level heating due to liquid water processes. In the stratiform region, the heating profile is shifted up or down by matching the melting level in the TOGA COARE lookup table with the observed one. Consistency checks indicate the revised SLH algorithm performs much better for both the convective and stratiform components than does the original one. The revised SLH algorithm was applied to PR data, and the results were compared with heating profiles derived diagnostically from SCSMEX sounding data. Key features of the vertical profiles agree well - in particular, the level of maximum heating. The revised SLH algorithm was also applied to PR data for February 1998 and February 1999. The results are compared with heating profiles derived by the convective - stratiform heating (CSH) algorithm. Because observed information on precipitation depth is used in addition to precipitation type and intensity, differences between shallow and deep convection are more distinct in the SLH algorithm in comparison with the CSH algorithm. C1 Osaka Prefecture Univ, Dept Aerosp Engn, Osaka 5998531, Japan. Univ Tokyo, Ctr Climate Syst Res, Kanagawa, Japan. Japan Agcy Marine Earth Sci & Technol, Inst Observat Res Global Change, Kanagawa, Japan. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland, Baltimore, MD 21201 USA. RP Shige, S (reprint author), Osaka Prefecture Univ, Dept Aerosp Engn, 1-1 Gakuen Cho, Osaka 5998531, Japan. EM shige@aero.osakafu-u.ac.jp RI PMM, JAXA/K-8537-2016 NR 95 TC 50 Z9 52 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1558-8424 J9 J APPL METEOROL CLIM JI J. Appl. Meteorol. Climatol. PD JUL PY 2007 VL 46 IS 7 BP 1098 EP 1124 DI 10.1175/JAM2510.1 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 198WB UT WOS:000248657100011 ER PT J AU Gonzalez-Cuevas, JA Refaat, TF Abedin, MN Elsayed-Ali, HE AF Gonzalez-Cuevas, Juan A. Refaat, Tamer F. Abedin, M. Nurul Elsayed-Ali, Hani E. TI Calculations of the temperature and alloy composition effects on the optical properties of AlxGa1-xAsySb1-y and GaxIn1-xAsySb1-y in the spectral range 0.5-6 eV SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CRITICAL-POINT PARAMETERS; INTERBAND CRITICAL-POINTS; DIELECTRIC FUNCTION; BAND-STRUCTURE; DISPERSION-RELATIONS; QUATERNARY ALLOYS; GASB; GAAS; GAP; DEPENDENCE AB A detailed analysis is presented on the temperature and alloy composition dependence of the optical properties of III-V alloys AlxGa1-xAsySb1-y and GaxIn1-xAsySb1-y in the energy range 0.5-6 eV. Expressions for the complex dielectric function are based on a semiempirical phenomenological model, which takes under consideration indirect and direct transitions below and above the fundamental absorption edge. Dielectric function and absorption coefficient calculations are in satisfactory agreement with available experimental data. Other dielectric related optical data, such as the refractive index, extinction, and reflection coefficients, can also be obtained from the model. C1 Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. Old Dominion Univ, Appl Res Ctr, Norfolk, VA 23529 USA. NASA, Langley Res Ctr, Pass Sensor Syst Branch, Hampton, VA 23681 USA. RP Elsayed-Ali, HE (reprint author), Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. EM helsayed@odu.edu NR 51 TC 15 Z9 15 U1 1 U2 4 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 2007 VL 102 IS 1 AR 014504 DI 10.1063/1.2751406 PG 11 WC Physics, Applied SC Physics GA 189WC UT WOS:000248018300101 ER PT J AU Wang, X Shakouri, A Yu, B Sun, XH Meyyappan, M AF Wang, Xi Shakouri, Ali Yu, Bin Sun, Xuhui Meyyappan, Meyya TI Study of phonon modes in germanium nanowires SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SILICON NANOWIRES; RAMAN; SPECTROSCOPY; TEMPERATURE; STOKES AB The observation of pure phonon confinement effect in germanium nanowires is limited due to the illumination sensitivity of Raman spectra. In this paper we measured Raman spectra for different size germanium nanowires with different excitation laser powers and wavelengths. By eliminating the local heating effect, the phonon confinement effect for small size nanowires was clearly identified. We have also fitted the Raman feature changes to estimate the size distribution of nanowires. (c) 2007 American Institute of Physics. C1 Univ Calif Santa Cruz, Baskin Sch Engn, Santa Cruz, CA 95064 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Shakouri, A (reprint author), Univ Calif Santa Cruz, Baskin Sch Engn, Santa Cruz, CA 95064 USA. EM wangxi@soe.ucsc.edu; ali@soe.ucsc.edu RI Sun, Xuhui /K-5689-2012 NR 16 TC 8 Z9 8 U1 0 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 JUL 1 PY 2007 VL 102 IS 1 AR 014304 DI 10.1063/1.2752134 PG 6 WC Physics, Applied SC Physics GA 189WC UT WOS:000248018300092 ER PT J AU Bateman, MG Stewart, MF Blakeslee, RJ Podgorny, SJ Christian, HJ Mach, DM Bailey, JC Daskar, D AF Bateman, M. G. Stewart, M. F. Blakeslee, R. J. Podgorny, S. J. Christian, H. J. Mach, D. M. Bailey, J. C. Daskar, D. TI A low-noise, microprocessor-controlled, internally digitizing rotating-vane electric field mill for airborne platforms SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB This paper reports on a new generation of aircraft- based rotating- vane- style electric field mills designed and built at NASA's Marshall Space Flight Center. The mills have individual microprocessors that digitize the electric field signal at the mill and respond to commands from the data system computer. The mills are very sensitive ( 1 V m(-1) bit(-1)), have a wide dynamic range (115 dB), and are very low noise (+/- 1 LSB). Mounted on an aircraft, these mills can measure fields from +/- 1 V m(-1) to +/- 500 kV m(-1). Once-per-second commanding from the data collection computer to each mill allows for precise timing and synchronization. The mills can also be commanded to execute a self-calibration in flight, which is done periodically to monitor the status and health of each mill. C1 Univ Space Res Assoc, Huntsville, AL USA. Univ Alabama, Huntsville, AL USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Engn Res Consulting, Huntsville, AL USA. RP Bateman, MG (reprint author), 320 Sparkman Dr, Huntsville, AL 35805 USA. EM monte.bateman@nasa.gov NR 12 TC 11 Z9 13 U1 2 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 2007 VL 24 IS 7 BP 1245 EP 1255 DI 10.1175/JTECH2039.1 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 197KE UT WOS:000248553100006 ER PT J AU Ridley, BA Zeng, T Wang, Y Atlas, EL Browell, EV Hess, PG Orlando, JJ Chance, K Richter, A AF Ridley, B. A. Zeng, T. Wang, Y. Atlas, E. L. Browell, E. V. Hess, P. G. Orlando, J. J. Chance, K. Richter, A. TI An ozone depletion event in the sub-arctic surface layer over Hudson Bay, Canada SO JOURNAL OF ATMOSPHERIC CHEMISTRY LA English DT Article DE ozone; ozone depletion; bromine; Hudson Bay; Arctic; TOPSE; GOME ID POLAR SUNRISE; BOUNDARY-LAYER; TROPOSPHERIC OZONE; HYDROCARBON MEASUREMENTS; ATOM CONCENTRATIONS; BRO CONCENTRATIONS; HIGH-LATITUDES; BROMINE OXIDE; CHEMISTRY; TOPSE AB During the Tropospheric Ozone Production about the Spring Equinox (TOPSE) program, aircraft flights during April 7-11, 2000 revealed a large area air mass capped below similar to 500 m altitude over Hudson Bay, Canada in which ozone was reduced from normal levels of 30-40 ppbv to as low as 0.5 ppbv. From some of the in-situ aircraft measurements, back-trajectory calculations, the tropospheric column of BrO derived from GOME satellite measurements, and results from a regional model, we conclude that the event did not originate from triggering of reactive halogen release in the sub-Arctic region of Hudson Bay but resulted from such an event occurring at higher latitudes over the islands of the northern Canada Archipelago and nearby Arctic Ocean with subsequent transport over a distance of 1,000-1,500 km to Hudson Bay. BrO (x) remained active during this transport despite considerable changes in the conditions of the underlying surface suggesting that chemical recycling during transport dominated any local halogen input from the surface. If all of the tropospheric column density of BrO is distributed uniformly within the surface layer, then the mixing ratio of BrO derived from the satellite measurements is at least a factor of 2-3 larger than derived indirectly from in situ aircraft measurements of the NO/NO2 ratio. C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Bremen, Inst Environm Sci, D-28334 Bremen, Germany. RP Ridley, BA (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, POB 3000, Boulder, CO 80307 USA. EM ridley@ucar.edu RI Richter, Andreas/C-4971-2008; Wang, Yuhang/B-5578-2014; Atlas, Elliot/J-8171-2015; Hess, Peter/M-3145-2015; OI Richter, Andreas/0000-0003-3339-212X; Hess, Peter/0000-0003-2439-3796; Chance, Kelly/0000-0002-7339-7577 NR 62 TC 8 Z9 8 U1 0 U2 5 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-7764 J9 J ATMOS CHEM JI J. Atmos. Chem. PD JUL PY 2007 VL 57 IS 3 BP 255 EP 280 DI 10.1007/s10874-007-9072-z PG 26 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 189PY UT WOS:000248002200004 ER PT J AU Yang, C Sun, W Tomblin, JS Smeltzer, SS AF Yang, Chihdar Sun, Wenjun Tomblin, John S. Smeltzer, Stanley S., III TI A semi-analytical method for determining the strain energy release rate of cracks in adhesively-bonded single-lap composite joints SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE adhesively-bonded joint; laminated plate theory; composite joint; strain energy release rate; virtual crack closure technique (VCCT); fracture mechanics ID ELEMENTS AB A semi-analytical method for determining the strain energy release rates due to a prescribed crack in an adhesively-bonded, single-lap composite joint subjected to axial tension is presented. The field equations in terms of displacements within the joint are formulated by using first-order shear deformable, laminated plate theory together with kinematic relations and force equilibrium conditions. The stress distributions for the adherends and adhesive are determined after the appropriate boundary and loading conditions are applied and the equations for the field displacements are solved. Based on the adhesive stress distributions, the forces at the crack tip are obtained and the strain energy release rates of the crack are determined by using the virtual crack closure technique (VCCT). Additionally, the test specimen geometry from both the ASTM D3165 and D1002 test standards are utilized during the derivation of the field equations in order to correlate analytical models with future test results. The system of second-order differential field equations is solved to provide the adherend and adhesive stress response using the symbolic computation tool, Maple 9. Finite element analyses using J-integral as well as VCCT were performed to verify the developed analytical model. The finite element analyses were conducted using the commercial finite element analysis software ABAQUS (TM). The results determined using the analytical method correlated well with the results from the finite element analyses. C1 Wichita State Univ, Dept Aerosp Engn, Wichita, KS 67260 USA. NASA Langley Res Ctr, Mech Struct & Mat Branch, Hampton, VA 23681 USA. RP Yang, C (reprint author), Wichita State Univ, Dept Aerosp Engn, Wichita, KS 67260 USA. EM charles.yang@wichita.edu NR 31 TC 10 Z9 12 U1 1 U2 6 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PD JUL PY 2007 VL 41 IS 13 BP 1579 EP 1602 DI 10.1177/0021998306069872 PG 24 WC Materials Science, Composites SC Materials Science GA 199HT UT WOS:000248687500003 ER PT J AU Chang, CH Liou, MS AF Chang, Chih-Hao Liou, Meng-Sing TI A robust and accurate approach to computing compressible multiphase flow: Stratified flow model and AUSM(+)-up scheme SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE multiphase flow; multifluid model; AUSM(+) scheme; stratified flow method ID 2-PHASE FLOW; EQUATIONS; AUSM; MULTIFLUID; SEQUEL; SPEEDS AB In this paper, we propose a new approach to compute compressible multifluid equations. Firstly, a single-pressure compressible multifluid model based on the stratified flow model is proposed. The stratified flow model, which defines different fluids in separated regions, is shown to be amenable to the finite volume method. We can apply the conservation law to each subregion and obtain a set of balance equations'. Secondly, the AUSM(+) scheme, which is originally designed for the compressible gas flow, is extended to solve compressible liquid flows. By introducing additional dissipation terms into the numerical flux, the new scheme, called AUSM(+)-up, can be applied to both liquid and gas flows. Thirdly, the contribution to the numerical flux due to interactions between different phases is taken into account and solved by the exact Riemann solver. We will show that the proposed approach yields an accurate and robust method for computing compressible multiphase flows involving discontinuities, such as shock waves and fluid interfaces. Several one-dimensional test problems are used to demonstrate the capability of our method, including the Ransom's water faucet problem and the air-water shock tube problem. Finally, several two dimensional problems will show the capability to capture enormous details and complicated wave patterns in flows having large disparities in the fluid density and velocities, such as interactions between water shock wave and air bubble, between air shock wave and water column(s), and underwater explosion. (c) 2007 Elsevier Inc. All rights reserved. C1 Univ Calif Santa Barbara, Ctr Risk Stuides & Safety, Goleta, CA 93117 USA. NASA, Glenn Res Ctr, Propuls Syst Div, Cleveland, OH 44135 USA. RP Chang, CH (reprint author), Univ Calif Santa Barbara, Ctr Risk Stuides & Safety, Goleta, CA 93117 USA. EM chchang@engineering.ucsb.edu; meng-sing.liou@grc.nasa.gov NR 32 TC 75 Z9 79 U1 0 U2 17 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 JUL 1 PY 2007 VL 225 IS 1 BP 840 EP 873 DI 10.1016/j.jcp.2007.01.007 PG 34 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 201TA UT WOS:000248854300043 ER PT J AU Nordstroem, J Mattsson, K Swanson, C AF Nordstroem, Jan Mattsson, Ken Swanson, Charles TI Boundary conditions for a divergence free velocity-pressure formulation of the Navier-Stokes equations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE Navier-Stokes; incompressible flow; divergence; boundary conditions ID FRACTIONAL-STEP METHOD; FINITE-DIFFERENCE APPROXIMATIONS; ACCURACY; ORDER; SUMMATION; PARTS; GRIDS AB New sets of boundary conditions for the velocity-pressure formulation of the incompressible Navier-Stokes equations are derived. The boundary conditions have the same form on both inflow and outflow boundaries and lead to a divergence free solution. Moreover, the specific form of the boundary condition makes it possible derive a symmetric positive definite equation system for the internal pressure. Numerical experiments support the theoretical conclusions. (c) 2007 Elsevier Inc. All rights reserved. C1 Uppsala Univ, Dept Informat Technol Sci Comp, SE-75105 Uppsala, Sweden. Royal Inst Technol, KTH, Dept Aeronaut & Vehicle Engn, SE-10044 Stockholm, Sweden. Swedish Def Res Agcy, Div Syst Technol, Dept Computat Phys, SE-16490 Stockholm, Sweden. Stanford Univ, Ctr Turbulence Res, Stanford, CA 94305 USA. NASA, Langley Res Ctr, Computat Aero Sci Branch, Hampton, VA 23681 USA. RP Nordstroem, J (reprint author), Uppsala Univ, Dept Informat Technol Sci Comp, SE-75105 Uppsala, Sweden. EM jan.Nordstrom@foi.se OI Nordstrom, Jan/0000-0002-7972-6183 NR 27 TC 28 Z9 28 U1 3 U2 10 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 JUL 1 PY 2007 VL 225 IS 1 BP 874 EP 890 DI 10.1016/j.jcp.2007.01.010 PG 17 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 201TA UT WOS:000248854300044 ER PT J AU Yee, HC Sjogreen, B AF Yee, H. C. Sjogreen, B. TI Development of low dissipative high order filter schemes for multiscale Navier-Stokes/MHD systems SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE high order methods; high order filter methods; multiresolution wavelet analysis of flow data; high-speed shock-turbulence interactions; Richtmyer-Meshkov instability; Navier-Stokes/MHD; unsteady flows ID HYPERBOLIC CONSERVATION-LAWS; SUPERSONIC REACTIVE FLOWS; FINITE-DIFFERENCE SCHEME; NUMERICAL DISSIPATION; WAVELET TRANSFORMS; EULER EQUATIONS; SIMULATION; MAGNETOHYDRODYNAMICS; INSTABILITY; RESOLUTION AB Recent progress in the development of a class of low dissipative high order (fourth-order or higher) filter schemes for multiscale Navier-Stokes, and ideal and non-ideal magnetohydrodynamics (MHD) systems is described. The four main features of this class of schemes are: (a) multiresolution wavelet decomposition of the computed flow data as sensors for adaptive numerical dissipative control, (b) multistep filter to accommodate efficient application of different numerical dissipation models and different spatial high order base schemes, (c) a unique idea in solving the ideal conservative MHD system (a non-strictly hyperbolic conservation law) without having to deal with an incomplete eigensystem set while at the same time ensuring that correct shock speeds and locations are computed, and (d) minimization of the divergence of the magnetic field (del center dot B) numerical error. By design, the flow sensors, different choice of high order base schemes and numerical dissipation models are stand-alone modules. A whole class of low dissipative high order schemes can be derived at ease, making the resulting computer software very flexible with widely applicable. Performance of multiscale and multiphysics test cases are illustrated with many levels of grid refinement and comparison with commonly used schemes in the literature. (c) 2007 Elsevier Inc. All rights reserved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Royal Inst Technol, NADA, S-10044 Stockholm, Sweden. RP Yee, HC (reprint author), NASA, Ames Res Ctr, Mail Stop 258-5, Moffett Field, CA 94035 USA. EM yee@nas.nasa.gov; bjorns@nada.kth.se NR 61 TC 30 Z9 31 U1 1 U2 8 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 JUL 1 PY 2007 VL 225 IS 1 BP 910 EP 934 DI 10.1016/j.jcp.2007.01.012 PG 25 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 201TA UT WOS:000248854300046 ER PT J AU Svard, M Carpenter, MH Nordstrom, J AF Svaerd, Magnus Carpenter, Mark H. Nordstrom, Jan TI A stable high-order finite difference scheme for the compressible Navier-Stokes equations, far-field boundary conditions SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE high-order finite difference methods; boundary conditions; compressible Navier-Stokes equations; stability; accuracy; wellposedness; summation-by-parts; simultaneous approximation terms AB We construct a stable high-order finite difference scheme for the compressible Navier-Stokes equations, that satisfy an energy estimate. The equations are discretized with high-order accurate finite difference methods that satisfy a Summation-By-Parts rule. The boundary conditions are imposed with penalty terms known as the Simultaneous Approximation Term technique. The main result is a stability proof for the full three-dimensional Navier-Stokes equations, including the boundary conditions. We show the theoretical third-, fourth-, and fifth-order convergence rate, for a viscous shock, where the analytic solution is known. We demonstrate the stability and discuss the non-reflecting properties of the outflow conditions for a vortex in free space. Furthermore, we compute the three-dimensional vortex shedding behind a circular cylinder in an oblique free stream for Mach number 0.5 and Reynolds number 500. (c) 2007 Elsevier Inc. All rights reserved. C1 Stanford Univ, Ctr Turbulence Res, Stanford, CA 94305 USA. NASA, Langley Res Ctr, Computat Methods & Simulat Branch, Hampton, VA 23681 USA. Swedish Def Res Agcy, Computat Phys Dept, Div Syst Technol, SE-16490 Stockholm, Sweden. Uppsala Univ, Dept Informat Technol, SE-75105 Uppsala, Sweden. Royal Inst Technol, KTH, Dept Aeronaut & Vehicle Engn, SE-10044 Stockholm, Sweden. RP Svard, M (reprint author), Stanford Univ, Ctr Turbulence Res, Bldg 500, Stanford, CA 94305 USA. EM magnus.svard@gmail.com OI Nordstrom, Jan/0000-0002-7972-6183 NR 27 TC 72 Z9 74 U1 1 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 EI 1090-2716 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUL 1 PY 2007 VL 225 IS 1 BP 1020 EP 1038 DI 10.1016/j.jcp.2007.01.023 PG 19 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 201TA UT WOS:000248854300051 ER PT J AU Kobayashi, T Simon, DL AF Kobayashi, Takahisa Simon, Donald L. TI Hybrid Kalman filter approach for aircraft engine in-flight diagnostics: Sensor fault detection case SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 51st ASME Turbo Expo 2006 CY MAY 06-11, 2006 CL Barcelona, SPAIN SP ASME, Int Gas Turbine Inst DE in-flight fault detection; on-board engine model; Kalman filter; flight safety ID NEURAL-NETWORK; JET ENGINES AB In this paper, a diagnostic system based on a uniquely structured Kalman filter is developed for its application to in-flightfault detection of aircraft engine sensors. The Kalman filter is a hybrid of a nonlinear on-board engine model (OBEM) and piecewise linear models. The utilization of the nonlinear OBEM allows the reference health baseline of the diagnostic system to be updated, through a relatively simple process, to the health condition of degraded engines. Through this health baseline update, the diagnostic effectiveness of the in-flight sensor fault detection system is maintained as the health of the engine degrades over time. The performance of the sensor-fault detection system is evaluated in a simulation environment at several operating conditions during the cruise phase of flight. C1 ASRC Aerosp Corp, Cleveland, OH 44135 USA. Glenn Res Ctr, USA, Res Lab, Cleveland, OH 44135 USA. RP Kobayashi, T (reprint author), ASRC Aerosp Corp, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 14 TC 18 Z9 19 U1 3 U2 7 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 2007 VL 129 IS 3 BP 746 EP 754 DI 10.1115/1.2718572 PG 9 WC Engineering, Mechanical SC Engineering GA 194QJ UT WOS:000248358600015 ER PT J AU Tursol, JA Lawrence, C Litt, JS AF Tursol, James A. Lawrence, Charles Litt, Jonathan S. TI Reduced-order Modeling and wavelet analysis of turbofan engine structural response due to foreign object damage (FOD) events SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB The development of a wavelet-based feature extraction technique specifically targeting FOD-event induced vibration signal changes in gas turbine engines is described. The technique performs wavelet analysis of accelerometer signals from specified locations on the engine and is shown to be robust in the presence of significant process and sensor noise. It is envisioned that the technique will be combined with Kalman filter thermall health parameter estimation for FOD-event detection via information fusion from these (and perhaps other) sources. Due to the lack of high-frequency FOD-event test data in the open literature, a reduced-order turbo/an structural model (ROM) was synthesized from a finite-element model modal analysis to support the investigation. In addition to providing test data for algorithm development, the ROM is used to determine the optimal sensor location for FOD-event detection. In the presence of significant noise, precise location of the FOD event in time was obtained using the developed wavelet-based feature. C1 QSS Grp Inc, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Tursol, JA (reprint author), Northrop Grumman Ship Syst, Adv Capabil Grp, 6608 Sunscope Dr, Ocean Springs, MS 39564 USA. NR 25 TC 1 Z9 2 U1 1 U2 7 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 2007 VL 129 IS 3 BP 814 EP 826 DI 10.1115/1.2718230 PG 13 WC Engineering, Mechanical SC Engineering GA 194QJ UT WOS:000248358600024 ER PT J AU Russell, RP Lara, M AF Russell, Ryan P. Lara, Martin TI Long-lifetime lunar repeat ground track orbits SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 07-11, 2005 CL Lake Tahoe, CA SP Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc ID PERIODIC-ORBITS; FROZEN ORBITS; SATELLITES; EUROPA; STABILITY AB A high degree and order lunar gravitational field is superimposed on the Earth-moon restricted three-body model to capture the dominating forces on a spacecraft in the vicinity of the room. For the synchronously rotating moon, periodic orbits in this unaveraged model map repeat ground tracks and represent higher-order solutions to the frozen orbit problem. The stable or near-stable solutions are found over a wide range of defining characteristics, making them suitable for long-lifetime parking applications such as science orbits, crew exploration vehicle parking orbits, and global coverage constellation orbits. A full ephemeris is considered for selected orbits to evaluate the validity of the time-invariant, simplified model. Of the most promising results are the low-altitude families of near-circular, inclined orbits that maintain long-term stability despite the highly nonspherical lunar gravity. The method is systematic and enables rapid design and analysis of long-life around any tidally locked celestial body with an arbitrarily high degrees and order spherical harmonic gravity field. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. Real Observ Armada, San Fernando, Spain. RP Russell, RP (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. EM Ryan.Russell@jpl.nasa.gov; mlara@roa.es RI Lara, Martin/L-6291-2014 OI Lara, Martin/0000-0001-6754-916X NR 42 TC 28 Z9 28 U1 1 U2 6 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 2007 VL 30 IS 4 BP 982 EP 993 DI 10.2514/1.27104 PG 12 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 190AO UT WOS:000248030300009 ER PT J AU Chen, LJ Fathpour, N Mehra, RK AF Chen, Lingji Fathpour, Nanaz Mehra, Raman K. TI Comparing antenna conical scan algorithms for spacecraft position estimation SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article C1 Sci Syst Co Inc, Woburn, MA 01801 USA. CALTECH, Jet Prop Lab, Guidance Navigat & Control Sect, Pasadena, CA 91109 USA. RP Chen, LJ (reprint author), Sci Syst Co Inc, 500 W Cummings Pk,Suite 3000, Woburn, MA 01801 USA. EM chen@ssci.com; Nanaz.Fathpour@jpl.nasa.gov; rkm@ssci.com NR 6 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 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JUL-AUG PY 2007 VL 30 IS 4 BP 1186 EP 1189 DI 10.2514/1.28663 PG 4 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 190AO UT WOS:000248030300035 ER PT J AU Markley, FL Oshman, Y AF Markley, F. Landis Oshman, Yaakov TI Averaging quaternions SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID VECTOR OBSERVATIONS; ATTITUDE DETERMINATION C1 NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Syst Engn Branch, Greenbelt, MD 20771 USA. SUNY Buffalo, Dept Mech & Aerosp Engn, Buffalo, NY 14260 USA. Technion Israel Inst Technol, Dept Aerosp Engn, IL-32000 Haifa, Israel. RP Markley, FL (reprint author), NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Syst Engn Branch, Greenbelt, MD 20771 USA. EM Landis.Markley@nasa.gov; yaakov.oshman@technion.ac.il NR 12 TC 51 Z9 67 U1 1 U2 6 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 2007 VL 30 IS 4 BP 1193 EP 1197 DI 10.2514/1.28949 PG 5 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 190AO UT WOS:000248030300037 ER PT J AU Pargett, DM Ardema, MD AF Pargett, Douglas M. Ardema, Mark D. TI Flight path optimization at constant altitude SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article; Proceedings Paper CT AIAA Guidance, Navigation and Control Conference CY AUG 15-18, 2005 CL San Francisco, CA SP AIAA ID AIRCRAFT; CRUISE C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Santa Clara Univ, Dept Mech Engn, Santa Clara, CA 95053 USA. RP Pargett, DM (reprint author), Monterey Bay Aquarium Res Inst, 7700 Sandholdt Rd, Moss Landing, CA 95039 USA. NR 10 TC 9 Z9 9 U1 1 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 2007 VL 30 IS 4 BP 1197 EP 1201 DI 10.2514/1.28954 PG 5 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 190AO UT WOS:000248030300038 ER PT J AU Kinzel, PJ Wright, CW Nelson, JM Burman, AR AF Kinzel, Paul J. Wright, C. Wayne Nelson, Jonathan M. Burman, Aaron R. TI Evaluation of an experimental LiDAR for surveying a shallow, braided, sand-bedded river SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article ID GRAVEL-BED; CHANNEL MORPHOLOGY; AERIAL-PHOTOGRAPHY; IMAGE-ANALYSIS; HABITAT AB Reaches of a shallow (<1.0 m), braided, sand-bedded river were surveyed in 2002 and 2005 with the National Aeronautics and Space Administration's Experimental Advanced Airborne Research LiDAR (EAARL) and concurrently with conventional surveygrade, real-time kinematic, global positioning system technology. The laser pulses transmitted by the EAARL instrument and the return backscatter waveforms from exposed-sand and submerged sand targets in the river were completely digitized and stored for postflight processing. The vertical mapping accuracy of the EAARL was evaluated by comparing the ellipsoidal heights computed from ranging measurements made using an EAARL terrestrial algorithm to nearby (<0.5 m apart) ground-truth ellipsoidal heights. After correcting for apparent systematic bias in the surveys, the root mean square er-ror of these heights with the terrestrial algorithm in the 2002 survey was 0.11 m for the 26 measurements taken on exposed sand and 0.18 m for the 59 measurements taken on submerged sand. In the 2005 survey, the root mean square error was 0.18 m for 92 measurements taken on exposed sand and 0.24 m for 434 measurements on submerged sand. In submerged areas the waveforms were complicated by reflections from the surface, water column entrained turbidity, and potentially the riverbed. When applied to these waveforms, especially in depths greater than 0.4 m, the terrestrial algorithm calculated the range above the riverbed. A bathymetric algorithm has been developed to approximate the position of the riverbed in these convolved waveforms and preliminary results are encouraging. C1 US Geol Survey, Geomorphol & Sediment Transport Lab, Golden, CO 80403 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Isl, VA 23337 USA. RP Kinzel, PJ (reprint author), US Geol Survey, Geomorphol & Sediment Transport Lab, 4620 Technol Dr,Suite 400, Golden, CO 80403 USA. EM pjkinzel@usgs.gov OI Kinzel, Paul/0000-0002-6076-9730 NR 21 TC 44 Z9 45 U1 0 U2 13 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD JUL PY 2007 VL 133 IS 7 BP 838 EP 842 DI 10.1061/(ASCE)0733-9429(2007)133:7(838) PG 5 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA 180TJ UT WOS:000247388600012 ER PT J AU Clayton, LM Cinke, M Meyyappan, M Harmon, JP AF Clayton, LaNetra M. Cinke, Martin Meyyappan, M. Harmon, Julie P. TI Dielectric properties of PMMA/soot nanocomposites SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE poly(methyl methacrylate); soot; nanocomposites; dielectric properties ID WALLED CARBON NANOTUBES; GLASS-TRANSITION; POLYMER COMPOSITES; SILICATE NANOCOMPOSITES; GAMMA-RADIATION; RELAXATION; BEHAVIOR; GROWTH; PERMITTIVITY; FABRICATION AB Dielectric analysis (DEA) of relaxation behavior in poly(methyl methacrylate) (PMMA) soot nanocomposites is described herein. The soot, an inexpensive material, consists of carbon nanotubes, amorphous and graphitic carbon and metal particles. Results are compared to earlier studies on PMMA/multi-walled nanotube (MWNT) composites and PMMA/single-walled nanotube (SWNT) composites. The beta relaxation process appeared to be unaffected by the presence of the soot, as was noted earlier in nanotube composites. The gamma relaxation region in PMMA, normally dielectrically inactive, was "awakened" in the PMMA/soot composite. This occurrence is consistent with previously published data on nanotube composites. The dielectric permittivity, epsilon ', increased with soot content. The sample with 1% soot exhibited a permittivity (at 100 Hz and 25 degrees C) of 7.3 as compared to 5.1 for neat PMMA. Soot increased the dielectric strength, Delta epsilon, of the composites. The 1% soot sample exhibited a dielectric strength of 6.38, while the neat PMMA had a value of 2.95 at 40 degrees C. The symmetric broadening term (a) was slightly higher for the 1% composite at temperatures near the secondary relaxation and near the primary relaxation, but all samples deviated from symmetrical semi-circular behavior (alpha = 1). The impact of the soot filler is seen more clearly in dielectric properties than in mechanical properties studies conducted earlier. C1 Univ S Florida, Dept Chem, Tampa, FL 33620 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Harmon, JP (reprint author), Univ S Florida, Dept Chem, Tampa, FL 33620 USA. NR 46 TC 5 Z9 5 U1 0 U2 9 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 2007 VL 7 IS 7 BP 2494 EP 2499 DI 10.1166/jnn.2007.428 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 165ZY UT WOS:000246347700039 PM 17663270 ER PT J AU Mulenburg, G AF Mulenburg, Gerald TI Managing projects SO JOURNAL OF PRODUCT INNOVATION MANAGEMENT LA English DT Book Review C1 NASA, Washington, DC 20546 USA. RP Mulenburg, G (reprint author), NASA, Washington, DC 20546 USA. NR 1 TC 0 Z9 0 U1 1 U2 2 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0737-6782 J9 J PROD INNOVAT MANAG JI J. Prod. Innov. Manage. PD JUL PY 2007 VL 24 IS 4 BP 410 EP 411 DI 10.1111/j.1540-5885.2007.00258_4.x PG 2 WC Business; Engineering, Industrial; Management SC Business & Economics; Engineering GA 190UP UT WOS:000248086400011 ER PT J AU Mulenburg, G AF Mulenburg, Gerald TI Running meetings SO JOURNAL OF PRODUCT INNOVATION MANAGEMENT LA English DT Book Review C1 NASA, Washington, DC 20546 USA. RP Mulenburg, G (reprint author), NASA, Washington, DC 20546 USA. NR 1 TC 0 Z9 0 U1 1 U2 2 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0737-6782 J9 J PROD INNOVAT MANAG JI J. Prod. Innov. Manage. PD JUL PY 2007 VL 24 IS 4 BP 410 EP 411 DI 10.1111/j.1540-5885.2007.00258_4.x PG 2 WC Business; Engineering, Industrial; Management SC Business & Economics; Engineering GA 190UP UT WOS:000248086400013 ER PT J AU Mulenburg, G AF Mulenburg, Gerald TI Leading teams SO JOURNAL OF PRODUCT INNOVATION MANAGEMENT LA English DT Book Review C1 NASA, Washington, DC 20546 USA. RP Mulenburg, G (reprint author), NASA, Washington, DC 20546 USA. NR 1 TC 0 Z9 0 U1 1 U2 2 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0737-6782 J9 J PROD INNOVAT MANAG JI J. Prod. Innov. Manage. PD JUL PY 2007 VL 24 IS 4 BP 410 EP 411 DI 10.1111/j.1540-5885.2007.00258_4.x PG 2 WC Business; Engineering, Industrial; Management SC Business & Economics; Engineering GA 190UP UT WOS:000248086400012 ER PT J AU Karabeyoglu, MA Cantwell, BJ Zilliac, G AF Karabeyoglu, M. Arif Cantwell, Brian J. Zilliac, Greg TI Development of scalable space-time averaged regression rate expressions for hybrid rockets SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA/ASME/SAE/ASEE 41st Joint Propulsion Conference CY JUL 10-13, 2005 CL Tucson, AZ SP AIAA, ASME, SAE, ASEE ID FUELS AB The fuel regression rate expressions reported in the hybrid literature often depend explicitly on the physical dimensions of the system such as the fuel port diameter. Typically, when these dimensional formulas are applied to systems with significantly different scales, they produce grossly inaccurate results. This paper addresses the development of scalable space-time averaged regression rate formulas for hybrid rockets. The derivation process hinges on the assumption that the local instantaneous regression rate is a function of the local mass flux and the axial port distance in the power law format as predicted by the classical theory developed by Marxman. In this study, we have developed physics-based nondimensional formulas for the space-time averaged regression rate and used these expressions to develop a scalable regression rate law fora selected propellant combination, paraffin-based SP-1a/ GOX, from limited motor data. Initially, space and time averaging are treated separately, which were later combined to develop a technique that allows for the coupling between the spatial and time variations to predict the port diameter and mass flow rate profiles as functions of time. Finally, a comprehensive technique to estimate the systematic and random errors on the regression rate and mass flux data is also outlined. C1 Stanford Univ, Dept Aeronaut & Astronaut, Palo Alto, CA 94306 USA. NASA, Ames Res Ctr, Mountain View, CA 94085 USA. NR 5 TC 8 Z9 8 U1 0 U2 9 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 2007 VL 23 IS 4 BP 737 EP 747 DI 10.2514/1.19226 PG 11 WC Engineering, Aerospace SC Engineering GA 190QC UT WOS:000248073000014 ER PT J AU Russell, CK Carter, R Ellis, DL Goudy, R AF Russell, Carolyn K. Carter, Robert Ellis, David L. Goudy, Richard TI Friction stir welding of GRCop-84 for combustion chamber liners SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 45th Structures, Structural Dynamics and Materials Conference CY APR 19-22, 2004 CL Palm Springs, CA SP Amer Inst Aeronaut & Astronaut, ASME, ASCE, AHS, ASC ID COPPER AB GRCop-84 is a copper-chromium-niobium alloy developed for liquid rocket engine combustion chamber liners. GRCop-84 exhibits superior properties over conventional copper-based alloys in a liquid hydrogen-oxygen operating environment. A program to demonstrate scale-up production capabilities of GRCop-84 to levels suitable for main combustion chamber production for the prototype rocket engine was undertaken. This paper describes a novel method of manufacturing the main combustion chamber liner. The process consists of several steps: extrude the GRCop-84 powder into billets, roll the billets into plates, bump form the plates into cylinder halves, and friction stir weld the halves into a cylinder. The cylinder is then metal spun formed to near net liner dimensions, followed by finish machining to the final configuration. This paper describes the friction stir weld process development, including tooling and nondestructive inspection techniques, culminating in the successful production of a liner preform completed through spin forming. C1 NASA, George C Marshall Space Flight Ctr, Mat Proc & Mfg, Huntsville, AL 35812 USA. NASA, John H Glenn Res Ctr Lewis Field, Cleveland, OH 44111 USA. Spin Tech, Paso Robles, CA 93446 USA. RP Russell, CK (reprint author), NASA, George C Marshall Space Flight Ctr, Mat Proc & Mfg, ED33, Huntsville, AL 35812 USA. NR 21 TC 1 Z9 1 U1 1 U2 4 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 2007 VL 23 IS 4 BP 756 EP 762 DI 10.2514/1.11645 PG 7 WC Engineering, Aerospace SC Engineering GA 190QC UT WOS:000248073000016 ER PT J AU Foster, JE Williams, GJ Patterson, MJ AF Foster, John E. Williams, George J. Patterson, Michael J. TI Characterization of an ion thruster neutralizer SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA/ASME/SAE/ASEE 41st Joint Propulsion Conference CY JUL 10-13, 2005 CL Tucson, AZ SP AIAA, ASME, SAE, ASEE ID HOLLOW-CATHODE; DISCHARGE AB The neutralizer of a high-power ion thruster was characterized over a range of flow rates at the nominal thruster operating condition of 3.6 A of ion beam current at a beam voltage of 5500 V. Near-neutralizer Langmuir probes were used to characterize the local plasma and detect the transition from spot to plume mode. Consistent with the Langmuir probe measurements, it was found that neutralizer coupling voltage, rather than the magnitude of neutralizer-keeper-voltage oscillations, was most indicative of the spot to plume mode transition. Additionally, neutralizer-keeper-barrel erosion due to extreme, off-axis ions was investigated. No such energetic ion flux was detected using strategically placed, coated witness plates. C1 NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Foster, JE (reprint author), NASA, John H Glenn Res Ctr, Mail Stop 16-1, Cleveland, OH 44135 USA. NR 22 TC 1 Z9 1 U1 2 U2 6 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 2007 VL 23 IS 4 BP 828 EP 835 DI 10.2514/1.22591 PG 8 WC Engineering, Aerospace SC Engineering GA 190QC UT WOS:000248073000025 ER PT J AU Polzin, KA Markusic, TE Stanojev, BJ Dehoyos, A Raitses, Y Smirnov, A Fisch, NJ AF Polzin, Kurt A. Markusic, Thomas E. Stanojev, Boris J. Dehoyos, Amado Raitses, Yevgeny Smirnov, Artem Fisch, Nathaniel J. TI Performance of a low-power cylindrical Hall thruster SO JOURNAL OF PROPULSION AND POWER LA English DT Article C1 NASA, George C Marshall Space Flight Ctr, Propuls Syst Dept, Nucl Syst Branch, Huntsville, AL 35812 USA. Madison Res Corp, Huntsville, AL 35805 USA. Princeton Plasma Phys Lab, Astrophys Sci Dept, Princeton, NJ 08543 USA. RP Polzin, KA (reprint author), NASA, George C Marshall Space Flight Ctr, Propuls Syst Dept, Nucl Syst Branch, Huntsville, AL 35812 USA. EM kurt.a.polzin@nasa.gov NR 14 TC 5 Z9 5 U1 1 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 2007 VL 23 IS 4 BP 886 EP 888 DI 10.2514/1.28595 PG 3 WC Engineering, Aerospace SC Engineering GA 190QC UT WOS:000248073000033 ER PT J AU Bruccoleri, AR Parkin, KLG Barmatz, M AF Bruccoleri, Alexander R. Parkin, Kevin L. G. Barmatz, M. TI Axial temperature behavior of a heat exchanger tube for microwave thermal rockets SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID ORBIT C1 NASA, Ames Res Ctr, Small Spacecraft Off, Moffett Field, CA 94035 USA. Dartmouth Coll, Hanover, NH 03755 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bruccoleri, AR (reprint author), NASA, Ames Res Ctr, Small Spacecraft Off, Moffett Field, CA 94035 USA. EM Alexander.R.Bruccoleri.07@Alum.Dartmouth.org NR 7 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 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JUL-AUG PY 2007 VL 23 IS 4 BP 889 EP 894 DI 10.2514/1.27847 PG 6 WC Engineering, Aerospace SC Engineering GA 190QC UT WOS:000248073000034 ER PT J AU Dlugach, JM Mishchenko, MI AF Dlugach, Janna M. Mishchenko, Michael I. TI Diffuse and coherent backscattering of polarized light: Polarization ratios for a discrete random medium composed of nonspherical particles SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT 9th International Conference on Eledtromagnetic and Light Scattering by Non-Spherical Particles CY JUN 05-09, 2006 CL Sobolev Astron Inst, St Petersburg, RUSSIA HO Sobolev Astron Inst ID ENHANCED BACKSCATTERING; SCATTERING AB For a sparse, disordered, plane-parallel particulate medium, we analyze quantitatively the effects of particle microphysical properties on the values of the linear and circular backscattering polarization ratios. Using numerically exact T-matrix and vector radiative-transfer codes, we performed computations for the following models: (1) a semi-infinite homogeneous layer composed of randomly oriented, polydisperse oblate spheroids with the real part of the refractive index equal to 1.2, 1.4 and 1.6 and the imaginary part of the refractive index equal to 0 and 0.01; (2) a semi-infinite homogeneous layer composed of randomly oriented, polydisperse, oblate circular cylinders with the refractive index 1.4; (3) finite homogeneous layers of various optical thickness composed of randomly oriented, polydisperse, oblate spheroids with the refractive index 1.55. Our computations demonstrate that the values of the polarization ratios depend substantially on particle shape, real and imaginary parts of the particle refractive index, particle size relative to the wavelength, illumination geometry and optical thickness. (C) 2007 Elsevier Ltd. All rights reserved. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Natl Acad Sci Ukraine, Main Astron Observ, UA-03680 Kiev, Ukraine. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM crmim@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 NR 14 TC 8 Z9 8 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JUL-AUG PY 2007 VL 106 IS 1-3 BP 21 EP 32 DI 10.1016/j.jqsrt.2007.01.004 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 182NC UT WOS:000247510300004 ER PT J AU Liu, L Mishchenko, MI AF Liu, Li Mishchenko, Michael I. TI Scattering and radiative properties of complex soot and soot-containing aggregate particles SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT 9th International Conference on Eledtromagnetic and Light Scattering by Non-Spherical Particles CY JUN 05-09, 2006 CL Sobolev Astron Inst, St Petersburg, RUSSIA HO Sobolev Astron Inst DE aggregates; scattering; optical cross-sections; single-scattering albedo; asymmetry parameter; scattering matrix; polarization; remote sensing; atmospheric radiation ID LIGHT-SCATTERING; TROPOSPHERIC AEROSOLS; OPTICAL-PROPERTIES; T-MATRIX; SPHERES; AFRICA; SIZE AB We use the superposition T-matrix method to compute the scattering matrix elements and optical cross-sections for a variety of complex soot and soot-containing aggregate particles in random orientation at a visible wavelength 0.628 mu m. It is shown that random variations in the geometrical configuration of monomers in a soot cluster for fixed fractal dimension and prefactor, monomer size, and number of monomers have a rather weak effect on scattering and absorption, at least in the visible part of the spectrum. Thus, the electromagnetic scattering and absorption characteristics of a single cluster realization are sufficient to represent the mean values obtained by averaging over many realizations of the "equivalent" clusters generated for the same fractal parameters. However, the results for the soot clusters differ fundamentally from those calculated for the volume-equivalent soot sphere and for the corresponding external mixture of soot monomers, assuming that there are no electromagnetic interactions between the monomers. We also compute and analyze the scattering and absorption properties of aerosols formed by semi-external aggregation of larger ammonium sulfate, silica, or dust particles with soot clusters as well as semi-external aggregates consisting of several components with different sizes and refractive indices. Depending on its chemical composition and size, the larger particle that is in touch with a soot cluster can strongly influence, or even dominate, the overall optical characteristics of the aggregate. Aggregation can result in stronger extinction, absorption, and scattering cross-sections relative to those computed for the corresponding external mixture. Possibly owing to mutual shadowing, the optical cross-sections of multi-component aggregates are smaller than those of their externally mixed counterparts, but by no more than similar to 20%. Implications of our study for analyses of remote sensing observations and atmospheric radiation balance computations are discussed. Published by Elsevier Ltd. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM crmim@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 NR 30 TC 71 Z9 72 U1 7 U2 24 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 JUL-AUG PY 2007 VL 106 IS 1-3 BP 262 EP 273 DI 10.1016/j.jqsrt.2007.01.020 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 182NC UT WOS:000247510300023 ER PT J AU Mishchenko, MI Videen, G Babenko, VA Khlebtsov, NG Wriedt, T AF Mishchenko, Michael I. Videen, Gorden Babenko, Victor A. Khlebtsov, Nikolai G. Wriedt, Thomas TI Comprehensive T-matrix reference database: A 2004-06 update SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT 9th International Conference on Electromagnetic and Light Scattering by Non-Spherical Particles CY JUN 05-09, 2006 CL Sobolev Astron Inst, St Petersburg, RUSSIA HO Sobolev Astron Inst DE electromagnetic scattering; T-matrix method ID AXIALLY-SYMMETRIC PARTICLES; GREENS-FUNCTION FORMALISM; MORPHOLOGY-DEPENDENT RESONANCES; LIGHT-SCATTERING SIMULATION; SIZE-DISTRIBUTION FUNCTION; MICROWAVE LIMB RADIANCES; VECTOR MULTIPOLE FIELDS; GENERALIZED MIE THEORY; ICE-CRYSTAL GEOMETRY; OPTICAL-PROPERTIES AB The T-matrix method is one of the most versatile, efficient, and widely used theoretical techniques for the computation of electromagnetic scattering by single and composite particles, discrete random media, and particles in the vicinity of an interface separating two half-spaces with different refractive indices. This paper presents an update to the comprehensive database of T-matrix publications authored by us previously and includes the publications that appeared since 2004. It also lists several earlier publications not included in the original database. (c) 2007 Elsevier Ltd. All rights reserved. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. USA, Res Lab, AMSRL IS EE, Adelphi, MD 20783 USA. Natl Acad Sci Belarus, Stepanov Inst Phys, Minsk 220072, Byelarus. Russian Acad Sci, Inst Biochem & Physiol Plants & Microorganisms, Saratov 410015, Russia. Inst Werkstofftech, D-28359 Bremen, Germany. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM crmim@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012; Khlebtsov, Nikolai/D-6199-2017; Pylaev, Timofey/A-8401-2016; OI Pylaev, Timofey/0000-0002-2701-3333; Khlebtsov, Nikolai/0000-0002-2055-7784 NR 283 TC 34 Z9 36 U1 0 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 EI 1879-1352 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JUL-AUG PY 2007 VL 106 IS 1-3 BP 304 EP 324 DI 10.1016/j.jqsrt.2007.01.022 PG 21 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 182NC UT WOS:000247510300027 ER PT J AU Mishchenko, MI Geogdzhayev, IV Cairns, B Carlson, BE Chowdhary, J Lacis, AA Liu, L Rossow, WB Travis, LD AF Mishchenko, Michael I. Geogdzhayev, Igor V. Cairns, Brian Carlson, Barbara E. Chowdhary, Jacek Lacis, Andrew A. Liu, Li Rossow, William B. Travis, Larry D. TI Past, present, and future of global aerosol climatologies derived from satellite observations: A perspective SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT 9th International Conference on Electromagnetic and Light Scattering by Non-Spherical Particles CY JUN 05-09, 2006 CL Sobolev Astron Inst, St Petersburg, RUSSIA HO Sobolev Astron Inst DE tropospheric aerosols; remote sensing ID RESEARCH SCANNING POLARIMETER; OPTICAL-THICKNESS RETRIEVALS; REMOTE-SENSING DATA; STRATOSPHERIC AEROSOLS; TROPOSPHERIC AEROSOLS; SCIENTIFIC OBJECTIVES; RADIATIVE PROPERTIES; REFLECTED SUNLIGHT; MODIS RETRIEVALS; DEPTH RETRIEVAL AB A number of passive satellite instruments have been used to develop global climatologies of terrestrial tropospheric aerosols by analyzing the properties of sunlight reflected by the atmosphere-surface system. The outcome of these efforts are several climatologies which all purport to represent the same aerosol characteristics such as optical thickness and size. However, the quantitative differences between these climatologies have been found to far exceed the corresponding individual uncertainty claims. The magnitude of these differences is alarming and necessitates a detailed critical assessment and integrated analysis that would go far beyond simple intercomparisons of various satellite products and comparisons of satellite aerosol optical thickness results with ground-based sun-photometer data. This paper outlines the framework for a global long-term satellite climatology of aerosol properties based on a consistent combination of previous, current, and near-future satellite retrievals. We also discuss potential future strategies for deriving a much improved aerosol climatology from Earth-orbiting satellites. Published by Elsevier Ltd. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, New York, NY 10025 USA. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM mmishchenko@giss.nasa.gov RI Lacis, Andrew/D-4658-2012; Carlson, Barbara/D-8319-2012; Rossow, William/F-3138-2015; Mishchenko, Michael/D-4426-2012; OI Cairns, Brian/0000-0002-1980-1022 NR 83 TC 82 Z9 85 U1 1 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 EI 1879-1352 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JUL-AUG PY 2007 VL 106 IS 1-3 BP 325 EP 347 DI 10.1016/j.jqsrt.2007.01.007 PG 23 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 182NC UT WOS:000247510300028 ER PT J AU Zhang, ZB Yang, P Kattawar, GW Wiscombec, WJ AF Zhang, Zhibo Yang, Ping Kattawar, George W. Wiscombec, Warren J. TI Single-scattering properties of Platonic solids in geometrical-optics regime SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT 9th International Conference on Eledtromagnetic and Light Scattering by Non-Spherical Particles CY JUN 05-09, 2006 CL Sobolev Astron Inst, St Petersburg, RUSSIA HO Sobolev Astron Inst DE single-scattering; particle nonsphericity; geometrical-optics method; Platonic solids ID LIGHT-SCATTERING; ICE CRYSTALS; ELECTROMAGNETIC SCATTERING; DIELECTRIC PARTICLES AB We investigate the single-scattering properties of the Platonic solids with size parameters in the geometrical-optics regime at wavelengths 0.66 and 11 mu m using the geometrical-optics method. The comparisons between the results for the Platonic solids and four types of spherical equivalence show that the equal-surface-area spherical equivalence has the smallest errors in terms of the extinction cross section at both wavelengths. At a wavelength of 0.66 mu m, all the spherical equivalences substantially overestimate the asymmetry factors of the Platonic solids; and in the case of strong absorption, they underestimate the single-scattering albedo. The comparisons also show that the spherical equivalences cannot be used to describe the spatial distribution of scattered intensity associated with a prismatic polyhedron. (c) 2007 Elsevier Ltd. All rights reserved. C1 Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zhang, ZB (reprint author), Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. EM zhibo_zhang@tamu.edu RI Zhang, Zhibo/D-1710-2010; Yang, Ping/B-4590-2011 OI Zhang, Zhibo/0000-0001-9491-1654; NR 18 TC 9 Z9 9 U1 0 U2 2 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 JUL-AUG PY 2007 VL 106 IS 1-3 BP 595 EP 603 DI 10.1016/j.jqsrt.2007.01.035 PG 9 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 182NC UT WOS:000247510300046 ER PT J AU Mishchenko, MI Liu, L AF Mishchenko, Michael I. Liu, Li TI Weak localization of electromagnetic waves by densely packed many-particle groups: Exact 3D results SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT 9th International Conference on Eledtromagnetic and Light Scattering by Non-Spherical Particles CY JUN 05-09, 2006 CL Sobolev Astron Inst, St Petersburg, RUSSIA HO Sobolev Astron Inst DE coherent backscattering; weak localization; electromagnetic scattering ID DISCRETE RANDOM MEDIUM; MULTIPLE-SCATTERING; COHERENT BACKSCATTERING; AGGLOMERATE PARTICLES; CLASSICAL DIFFUSION; LIGHT; POLARIZATION AB We use the superposition T-matrix method to solve the Maxwell equations and compute electromagnetic scattering characteristics of a 3D volume filled with densely packed, randomly distributed, wavelength- sized spherical particles. Our numerically exact data provide, for the first time, a direct demonstration of the onset and evolution of coherent backscattering with increasing number of particles and prove unequivocally that weak localization of electromagnetic waves can survive even in densely packed particulate media. (c) Published by Elsevier Ltd. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM mmishchenko@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 NR 31 TC 20 Z9 20 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 JUL-AUG PY 2007 VL 106 IS 1-3 BP 616 EP 621 DI 10.1016/j.jqsrt.2007.01.039 PG 6 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 182NC UT WOS:000247510300048 ER PT J AU Drouin, BJ AF Drouin, Brian J. TI Temperature dependent pressure induced linewidths of O-16(2) and (OO)-O-18-O-16 transitions in nitrogen, oxygen and air SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE oxygen; linewidths; pressure broadening; atmospheric spectra ID INDUCED LINESHAPE; ROTATIONAL LINE; MICROWAVE; ABSORPTION; BAND; GHZ; O-2; PARAMETERS; DISPERSION; SPECTRUM AB The temperature dependent pressure induced broadening of several oxygen resonant transitions have been measured. For O-16(2) the isolated magnetic fine-structure transition J'(N') <- J(N) = 1(1) <- 1(0) and the magnetic rotational transition 3(2) <- 1(2) are investigated in both nitrogen and oxygen. Additionally, pressure broadening of the magnetic rotational transition of (OO)-O-18-O-16 2(1) <- 0(1) is measured in air. This work improves precision and accuracy of the linewidth of the fine-structure transition and provides the first temperature dependent linewidth measurements at higher frequency. (c) 2007 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Drouin, BJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM brian.j.drouin@jpl.nasa.gov NR 28 TC 10 Z9 10 U1 0 U2 2 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 JUL PY 2007 VL 105 IS 3 BP 450 EP 458 DI 10.1016/j.jqsrt.2006.12.001 PG 9 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 155FX UT WOS:000245564400008 ER PT J AU Rinsland, CP Nassar, R Boone, CD Bernath, P Chiou, L Weisenstein, DK Mahieu, E Zander, R AF Rinsland, Curtis P. Nassar, Ray Boone, Chris D. Bernath, Peter Chiou, Linda Weisenstein, Debra K. Mahieu, Emmanuel Zander, Rodolphe TI Spectroscopic detection of COClF in the tropical and mid-latitude lower stratosphere SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE remote sensing; stratospheric chemistry; infrared atmospheric remote sounding; measurement-model comparisons; stratospheric chlorine chemistry; stratospheric fluorine chemistry ID FOURIER-TRANSFORM SPECTROMETER; INFRARED SOLAR SPECTRA; 2-DIMENSIONAL MODEL; GLOBAL INVENTORY; FLUORINE; CHLORINE; CHEMISTRY; RETRIEVALS; EMISSIONS; TRANSPORT AB We report retrievals of COClF (carbonyl chlorofluoride) based on atmospheric chemistry experiment (ACE) solar occultation spectra recorded at tropical and mid-latitudes during 2004-2005. The COClF molecule is a temporary reservoir of both chlorine and fluorine and has not been measured previously by remote sensing. A maximum COClF mixing ratio of 99.7 +/- 48.0 pptv (10(-12) per unit volume, 1 sigma) is measured at 28 km for tropical and subtropical occultations (latitudes below 20 degrees in both hemispheres) with lower mixing ratios at both higher and lower altitudes. Northern hemisphere mid-latitude mixing ratios (30-50 degrees N) resulted in an average profile with a peak mixing ratio of 51.7 +/- 132.1 pptv, 1 sigma, at 27 km, also decreasing above and below that altitude. We compare the measured average profiles with the one reported set of in situ lower stratospheric mid-latitude measurements from 1986 and 1987, a previous two-dimensional (2-D) model calculation for 1987 and 1993, and a 2-D-model prediction for 2004. The measured average tropical profile is in close agreement with the model prediction; the northern mid-latitude profile is also consistent, although the peak in the measured profile occurs at a higher altitude (2.5-4.5 km offset) than in the model prediction. Seasonal average 2-D-model predictions of the COClF stratospheric distribution for 2004 are also reported. (c) 2006 Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. Harvard Univ, Dept Earth & Planetary Sci, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Sci Applicat Int Corp, Hampton, VA 23666 USA. Atmospher & Environm Res Inc, Lexington, MA 02421 USA. Univ Liege, Inst Astrophys & Geophys, B-4000 Liege, Belgium. RP Rinsland, CP (reprint author), NASA, Langley Res Ctr, Sci Directorate, Mail Stop 401A, Hampton, VA 23681 USA. EM c.p.rinsland@larc.nasa.gov; ray@io.harvard.edu; eboone@acebox.uwaterloo.ca; bernath@uwaterloo.ca; l.s.chiou@larc.nasa.gov; dweisens@aer.com; Emmanuel.Mahieu@ulg.ac.be; R.Zander@ulg.ac.be RI Bernath, Peter/B-6567-2012; OI Bernath, Peter/0000-0002-1255-396X; Nassar, Ray/0000-0001-6282-1611; Mahieu, Emmanuel/0000-0002-5251-0286 NR 36 TC 7 Z9 7 U1 0 U2 0 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 JUL PY 2007 VL 105 IS 3 BP 467 EP 475 DI 10.1016/j.jqsrt.2006.11.013 PG 9 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 155FX UT WOS:000245564400010 ER PT J AU Remsberg, E Lingenfelser, G Natarajan, M Gordley, L Marshall, BT Thompson, E AF Remsberg, Ellis Lingenfelser, Gretchen Natarajan, Murali Gordley, Larry Marshall, B. Thomas Thompson, Earl TI On the quality of the Nimbus 7 LIMS version 6 ozone for studies of the middle atmosphere SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE satellite; ozone; infrared limb-sounder; stratosphere ID NONLOCAL THERMODYNAMIC-EQUILIBRIUM; UPPER-STRATOSPHERE; INFRARED MONITOR; RADIANCE; PROFILES; VARIABILITY; MESOSPHERE; PARAMETERS; BAND; O-3 AB The Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) radiance profile dataset of 1978/79 was reconditioned and reprocessed to Version 6 (V6) profiles of temperature and species that are improved significantly over those from Version 5 (V5). The LIMS V6 dataset was archived for public use in 2002. Improvements for its ozone include: (1) a more accurate accounting for instrument and spacecraft motion effects in the radiances, (2) the use of better spectroscopic line parameters for its ozone forward model, (3) retrievals of all its scans, (4) more accurate and compatible temperature versus pressure profiles (or T(p)) that are needed for the registration of the ozone radiances and for the removal of temperature effects from them, and (5) a better accounting for interfering species in the lower stratosphere. The retrieved V6 ozone profiles extend from near cloud top altitudes to about 80 km and from 64S to 84N latitude with better sampling along the orbit than for the V5 dataset. Calculated estimates of the single-profile precision and accuracy are provided; precision estimates based on the data themselves are of order 3% or better from 1 to 30 hPa. Estimates of total systematic error are hard to generalize because the separate sources of error may not all be of the same sign, and they depend somewhat on the atmospheric state. It is estimated that the accuracy of the V6 zonal mean ozone distribution is within +/- 9% from 50-10 hPa, improving to +/- 7% in the uppermost stratosphere. Simulation studies show that the LIMS T(p) retrievals are underestimating slightly the small amplitudes of the atmospheric temperature tides, which affect the retrieved day/night ozone differences. There are also small biases in the middle to lower stratosphere for the ascending versus descending node LIMS ozone, due principally to not accounting for the asymmetric weighting of its radiance within the tangent layer. The total accuracy for the LIMS ozone was assessed by comparing its daily zonal mean, daytime distributions against those from the Nimbus 7 SBUV Version 8 (V8) dataset for the same period. The LIMS V6 ozone agrees well with SBUV, except between 2 and 5 hPa where the LIMS ozone is greater. That bias is related to the differing vertical resolutions and forward models for the two experiments. The accuracy for LIMS V6 ozone in the lower stratosphere is improved over that reported for V5, as indicated by a small set of V6 comparisons with ECC ozonesonde profiles. Comparisons of diurnal, photochemical model calculations with the monthly-averaged, upper stratospheric ozone obtained with LIMS V6 indicate only a slight ozone deficit for the model at about 2 hPa. However, that deficit exhibits little to no seasonal variation and is in good agreement with similar model comparisons for a seasonal time series of ozone obtained with ground-based microwave instruments. Because the LIMS V6 ozone has improved accuracy and sampling versus that of V5 for the lower stratosphere it should now be possible to conduct quantitative studies of ozone transport and chemistry for the northern hemisphere, polar winter/spring of 1978/79-a time period when the catalytic loss of ozone due to reactive chlorine should not have been a major factor for the Arctic stratosphere. (c) 2007 Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. SAIC Inc, Hampton, VA 23661 USA. GATS Inc, Newport News, VA 23606 USA. RP Remsberg, E (reprint author), NASA, Langley Res Ctr, Sci Directorate, Mail Stop 401B, Hampton, VA 23681 USA. EM Ellis.E.Remsberg@nasa.gov NR 31 TC 10 Z9 10 U1 1 U2 3 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 JUL PY 2007 VL 105 IS 3 BP 492 EP 518 DI 10.1016/j.jqsrt.2006.12.005 PG 27 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 155FX UT WOS:000245564400012 ER PT J AU Wang, ZJ Liu, Y May, G Jameson, A AF Wang, Z. J. Liu, Yen May, Georg Jameson, Antony TI Spectral difference method for unstructured grids II: Extension to the Euler equations SO JOURNAL OF SCIENTIFIC COMPUTING LA English DT Article DE high-order; conservation laws; unstructured grids; spectral difference; spectral collocation method; Euler equations ID FINITE VOLUME METHOD; CONSERVATION-LAWS; POLYNOMIAL INTERPOLATION; BASIC FORMULATION; SCHEMES; SYSTEMS; SOLVERS; FLOW AB An efficient, high-order, conservative method named the spectral difference method has been developed recently for conservation laws on unstructured grids. It combines the best features of structured and unstructured grid methods to achieve high-computational efficiency and geometric flexibility; it utilizes the concept of discontinuous and high-order local representations to achieve conservation and high accuracy; and it is based on the finite-difference formulation for simplicity. The method is easy to implement since it does not involve surface or volume integrals. Universal reconstructions are obtained by distributing solution and flux points in a geometrically similar manner for simplex cells. In this paper, the method is further extended to nonlinear systems of conservation laws, the Euler equations. Accuracy studies are performed to numerically verify the order of accuracy. In order to capture both smooth feature and discontinuities, monotonicity limiters are implemented, and tested for several problems in one and two dimensions. The method is more efficient than the discontinuous Galerkin and spectral volume methods for unstructured grids. C1 Iowa State Univ, Dept Aerosp Engn, Ames, IA 50011 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Stanford Univ, Dept Aeronaut & Astronaut, Stanford, CA 94305 USA. RP Wang, ZJ (reprint author), Iowa State Univ, Dept Aerosp Engn, 2271 Howe Hall, Ames, IA 50011 USA. EM zjw@iastate.edu; liu@nas.nasa.gov RI Wang, Z.J./A-9628-2010 OI Wang, Z.J./0000-0002-6203-6303 NR 32 TC 61 Z9 64 U1 1 U2 9 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0885-7474 EI 1573-7691 J9 J SCI COMPUT JI J. Sci. Comput. PD JUL PY 2007 VL 32 IS 1 BP 45 EP 71 DI 10.1007/s10915-006-9113-9 PG 27 WC Mathematics, Applied SC Mathematics GA 178ZN UT WOS:000247259200003 ER PT J AU Sokolowski, WM Tan, SC AF Sokolowski, Witold M. Tan, Seng C. TI Advanced self-deployable structures for space applications SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID ANTENNA AB Cold-hibernated elastic memory structures technology is one of the most recent results of the quest for simple, reliable, and low-cost self-deployable structures. The cold-hibernated elastic memory technology uses shape-memory polymers in open-cell foam structures or sandwich structures made of shape-memory-polymer foam cores and polymeric laminated-composite skins. It takes advantage of a polymer's shape memory and the corresponding internal elastic recovery forces to self-deploy a compacted structure. This paper describes these structures and their major advantages over other expandable and deployable structures presently used. Previous experimental and analytical results indicate that the cold-hibernated elastic memory foam technology can perform robustly in the Earth's environment as well as in space. Further improvements in cold-hibernated elastic memory technology that can widen potential space applications, including advanced solar-sail structural concepts, are revealed and described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Wright Mat Res Co, Beavercreek, OH 45430 USA. RP Sokolowski, WM (reprint author), CALTECH, Jet Prop Lab, Mech Syst Div, Mail Stop 125-109,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 33 TC 44 Z9 44 U1 5 U2 37 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 2007 VL 44 IS 4 BP 750 EP 754 DI 10.2514/1.22854 PG 5 WC Engineering, Aerospace SC Engineering GA 197JJ UT WOS:000248550700003 ER PT J AU Gaspar, JL Jones, TW Murphy, DM AF Gaspar, James L. Jones, Thomas W. Murphy, David M. TI Solar sail structural characterization test program SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB The NASA in-space propulsion program sponsored intensive solar-sail technology and systems design, development, and hardware demonstration activities over the past three years. Efforts to validate an ATK Space Systems designed scalable solar sail system by functional demonstration in relevant environments, together with structural test-analysis correlation activities have recently been successfully completed. The tests spanned three phases of the program, with each phase lasting approximately I year; phase 1 focused on component tests of a mast segment and sail quadrant, phase 2 focused on a 10-m quadrant with two supporting masts, and phase 3 focused on a 20-m sail system with all four quadrants and masts. These tests were conducted for the purpose of validating analytical models that would be required by a flight test program to predict in-space performance. Specific tests included static shape testing using photogrammetry and modal vibration tests on the sail in a 1 torr vacuum environment using various excitation locations and techniques. The excitation methods were evaluated for their applicability to in-vacuum ground testing and their traceability to the development of on-orbit flight test techniques. The solar-sail masts were modal vibration tested in ambient atmospheric conditions and these results are also discussed. C1 NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. ATK Space Syst & Sensors, Solar Arrays & Deployables, Goleta, CA 93117 USA. RP Gaspar, JL (reprint author), NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. NR 13 TC 3 Z9 3 U1 1 U2 3 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 2007 VL 44 IS 4 BP 765 EP 783 DI 10.2514/1.22897 PG 19 WC Engineering, Aerospace SC Engineering GA 197JJ UT WOS:000248550700005 ER PT J AU Davis, MC Sim, AG Rhode, M Johnson, KD AF Davis, Mark C. Sim, Alexander G. Rhode, Matthew Johnson, Kevin D., Sr. TI Wind-tunnel results of the B-52B with the X-43A stack SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA 24th Applied Aerodynamics Conference CY JUN 05-08, 2006 CL San Francisco, CA SP Amer Inst Aeronaut & Astronaut AB A low-speed wind-tunnel test was performed with a 3%-scale model of a booster rocket mated to an X-43A research vehicle, a combination referred to as the Hyper-X launch vehicle. The test was conducted both in freestream air and in the presence of a partial model of the B-52B airplane. The objectives of the test were to obtain force and moment data to generate structural loads affecting the pylon of the B-52B airplane and to determine the aerodynamic influence of the B-52B on the Hyper-X launch vehicle for evaluating launch separation characteristics. The wind-tunnel test was conducted at a low-speed wind tunnel in Hampton, Virginia. All moments and forces reported are based either on the aerodynamic influence of the B-52B airplane or are for the Hyper-X launch vehicle in freestream air. Overall, the test showed that the B-52B airplane imparts a strong downwash onto the Hyper-X launch vehicle, reducing the net lift of the Hyper-X launch vehicle. Pitching and rolling moments are also imparted onto the booster and are a strong function of the launch-drop angle of attack. C1 NASA, Dryden Flight Res Ctr, Analyt Serv & Mat Inc, Edwards AFB, CA 93523 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Davis, MC (reprint author), NASA, Dryden Flight Res Ctr, Analyt Serv & Mat Inc, POB 273,Mail Stop 2228, Edwards AFB, CA 93523 USA. NR 3 TC 0 Z9 0 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 2007 VL 44 IS 4 BP 871 EP 877 DI 10.2514/1.27191 PG 7 WC Engineering, Aerospace SC Engineering GA 197JJ UT WOS:000248550700014 ER PT J AU Marchand, BG Howell, KC Wilson, RS AF Marchand, Belinda G. Howell, Kathleen C. Wilson, Roby S. TI Improved corrections process for constrained trajectory design in the n-body problem SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID RESTRICTED 3-BODY PROBLEM; PERIODIC-ORBITS; NUMERICAL DETERMINATION; POINTS; SATELLITE; SYSTEM AB The general objective is the development of efficient techniques for preliminary design of trajectory arcs in nonlinear autonomous dynamic systems in which the desired solution is subject to algebraic interior and/or exterior constraints. For application to the n-body problem, trajectories must satisfy specific requirements, e.g., periodicity in terms of the states, interior or boundary constraints, and specified coverage. Thus, a strategy is formulated in a sequence of increasingly complex. steps: 1) a trajectory is first modeled as a series of arcs (analytical or numerical) and general trajectory characteristics and timing requirements are established; 2) the specific constraints and associated partials are formulated; 3) a corrections process ensures position and velocity continuity while satisfying the constraints; and finally, 4) the solution is transitioned to a full model employing ephemerides. Though the examples pertain to spacecraft mission design, the methodology is generally applicable to autonomous systems subject to algebraic constraints. For spacecraft mission design applications, an immediate advantage of this approach, particularly for the identification of periodic orbits, is that the startup solution need not exhibit any symmetry to achieve the objectives. C1 Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. CALTECH, Jet Prop Lab, Guidance Navigat & Control Sect, Pasadena, CA 91109 USA. RP Marchand, BG (reprint author), Univ Texas, Aerosp Engn & Engn Mech Dept, Austin, TX 78712 USA. NR 24 TC 19 Z9 21 U1 1 U2 5 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 2007 VL 44 IS 4 BP 884 EP 897 DI 10.2514/1.27205 PG 14 WC Engineering, Aerospace SC Engineering GA 197JJ UT WOS:000248550700016 ER PT J AU Sprofera, JD Cabell, RH Gibbs, GP Clark, RL AF Sprofera, Joseph D. Cabell, Randolph H. Gibbs, Gary P. Clark, Robert L. TI Structural acoustic control of plates with variable boundary conditions: Design methodology SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID ACTIVE CONTROL; SOUND-TRANSMISSION; DISTURBANCE REJECTION; FLEXIBLE STRUCTURES; SENSOR PLACEMENT; RADIATION; ACTUATOR; NOISE; REDUCTION; VIBRATION AB A method for optimizing a structural acoustic control system subject to variations in plate boundary conditions is provided. The assumed modes method is used to build a plate model with varying levels of rotational boundary stiffness to simulate the dynamics of a plate with uncertain edge conditions. A transducer placement scoring process, involving Hankel singular values, is combined with a genetic optimization routine to find spatial locations robust to boundary condition variation. Predicted frequency response characteristics are examined, and theoretically optimized results are discussed in relation to the range of boundary conditions investigated. Modeled results indicate that it is possible to minimize the impact of uncertain boundary conditions in active structural acoustic control by optimizing the placement of transducers with respect to those uncertainties. (c) 2007 Acoustical Society of America. C1 Duke Univ, Pratt Sch Engn, Durham, NC 27708 USA. NASA Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. NASA Langley Res Ctr, Quiet Aircraft Technol Project, Hampton, VA 23681 USA. RP Sprofera, JD (reprint author), 1602 N Rowell Ave, Manhattan Beach, CA 90266 USA. EM joe.sprofera@gmail.com; r.h.cabell@larc.nasa.gov; gary@aeqisound.com; rclark@duke.edu NR 31 TC 7 Z9 7 U1 0 U2 3 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUL PY 2007 VL 122 IS 1 BP 271 EP 279 DI 10.1121/1.2739404 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 191WA UT WOS:000248161500027 PM 17614487 ER PT J AU Bhagwat, MJ Moulton, MA Caradonna, FX AF Bhagwat, Mahendra J. Moulton, Marvin A. Caradonna, Francis X. TI Development of a CFD-based hover performance prediction tool for engineering analysis SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article AB This paper concerns the development of a second -generation implementation of the vorticity embedding method for the prediction of rotor hover performance. The basic method, encoded in the HELIX-IA code, is an Eulerian-Lagrangian, computational fluid dynamics (CFD)-based procedure that utilizes an Eulerian potential flow solution combined with a Lagrangian wake convection. The blade(s) can be represented either as a lifting-surface or as a lifting-line with a specified circulation (loading) distribution. Furthermore, the basic method is hybridized with a Reynolds averaged Navier-Stokes (RANS) code, TURNS. The HELIX-IA code provides the wake convection and associated induced inflow while the TURNS code provides the surface viscous flow. The method is grid point efficient because the CFD solver is not burdened with resolving the entire shed wake. The importance of recent enhancements to the basic HELIX-IA methodology is demonstrated by a good comparison of predictions (performance, loading and wake trajectory) with available model scale data. Application of the new hybrid option of HELIX-IA to the UH-60A Black Hawk rotor provides a first demonstration of this method. Convergence of the hybrid solution is good, showing the basic viability of the approach. Preliminary computations show a strong dependence of wake trajectory on tip loading, and the need for tip grid improvement in order to attain better accuracy. C1 ELORET Corp, Ames Res Ctr, Moffett Field, CA USA. USA, AMRDEC, Aviat Engn Directorate, Redstone Arsenal, AL 35898 USA. USA, AMRDEC, Aeroflightdynam Directorate, AMRDEC, Moffett Field, CA USA. RP Bhagwat, MJ (reprint author), ELORET Corp, Ames Res Ctr, Moffett Field, CA USA. EM bliagwat@merlin.arc.nasa.gov NR 12 TC 6 Z9 6 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 2007 VL 52 IS 3 BP 175 EP 188 PG 14 WC Engineering, Aerospace SC Engineering GA 194CE UT WOS:000248320700001 ER PT J AU Floros, MW Johnson, W AF Floros, Matthew W. Johnson, Wayne TI Stability and control analysis of the slowed-rotor compound helicopter configuration SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT 60th Annual Forum of the American-Helicopter-Society CY JUN 07-10, 2004 CL Baltimore, MD SP Amer Helicopter Soc AB Stability and control of rotors at high advance ratio are considered. Stability of teetering, articulated, and gimbaled hub types is considered with a simple flapping blade analysis. Rotor control in autorotation for teetering and articulated hub types is examined in more detail for a compound helicopter (rotor and fixed wing) using the comprehensive analysis CAMRAD II. Autorotation is found to be possible at two distinct trim conditions with different sharing of lift between the rotor and wing. Stability predictions obtained using the analytical rigid flapping blade analysis and a rigid blade CAMRAD II model compare favorably. For the flapping blade analysis, the teetering rotor is found to be the most stable hub type, showing no instabilities up to an advance ratio of 3 and a Lock number of 18. Analysis of the trim controls, lift, power, and blade flapping shows that for small positive collective pitch, trim can be maintained without excessive control input or flapping angles for both teetering and articulated rotors. C1 USA, Res Lab, Hampton, VA USA. NASA, Ames Res Ctr, Aeromech Branch, Moffett Field, CA 94035 USA. RP Floros, MW (reprint author), USA, Res Lab, Hampton, VA USA. EM matt.floros@us.anny.mil NR 12 TC 6 Z9 9 U1 1 U2 5 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 2007 VL 52 IS 3 BP 239 EP 253 PG 15 WC Engineering, Aerospace SC Engineering GA 194CE UT WOS:000248320700006 ER PT J AU Olsen, CA Fowler, WT AF Olsen, Carrie A. Fowler, Wallace T. TI Use of a genetic algorithm to assess relative motion in highly elliptic orbits SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article; Proceedings Paper CT AAS/AIAA 14th Space Flight Mechanics Meeting CY FEB 08-12, 2004 CL Maui, HI SP AAS, Amer Inst Aeronaut & Astronaut AB This paper examines final rendezvous between two vehicles in highly elliptic orbits. The range of eccentricities addressed is 0.6 to 0.9. Due to the varying orbital speeds of the two vehicles, the relative motion during elliptic rendezvous is highly dependent on initial conditions and differs significantly from the relative motion seen in circular rendezvous. The character of the motion has important implications for operational and safety considerations. The development of relative motion targeting and propagation procedures that output relative coordinates in a suitable curvilinear coordinate system is discussed. These procedures are subsequently combined with a genetic algorithm optimization that is used to globally characterize the solution space. Results of genetic algorithm studies are presented and a fuel-optimal family of solutions is identified for further study and characterization. C1 [Olsen, Carrie A.] Mississippi State Univ, Mississippi State, MS 39762 USA. [Olsen, Carrie A.; Fowler, Wallace T.] Univ Texas Austin, Dept Aerosp Engn & Engn Mech, Austin, TX 78712 USA. [Olsen, Carrie A.] NASA, Marchall Space Flilght Ctr, Washington, DC 20546 USA. RP Olsen, CA (reprint author), Mississippi State Univ, Mississippi State, MS 39762 USA. NR 20 TC 0 Z9 0 U1 0 U2 4 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 2007 VL 55 IS 3 BP 293 EP 309 PG 17 WC Engineering, Aerospace SC Engineering GA 297LH UT WOS:000255617700002 ER PT J AU Desai, PN Knocke, PC AF Desai, Prasun N. Knocke, Philip C. TI Mars exploration rovers entry, descent, and landing trajectory analysis SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 15-19, 2004 CL Providence, RI SP Amer Inst Aeronaut & Astronaut, AAS AB The Mars Exploration Rover mission successfully landed two rovers "Spirit" and "Opportunity" on Mars on January 4th and 25th of 2004, respectively. In this paper, the trajectory analysis performed to define the entry, descent, and landing (EDL) scenario is described. The entry requirements and constraints are presented, as well as uncertainties used in a Monte Carlo dispersion analysis to statistically assess the robustness of the entry design to off-nominal conditions. In the analysis, six-degree-of-freedom and three-degree-of-freedom trajectory results are compared to assess the entry characteristics of the capsule. Comparison of the pre-entry results to preliminary post-landing reconstruction data shows that all EDL parameters were within the requirements. In addition, the final landing locations for both Spirit and Opportunity were within 15 km from the target. C1 [Desai, Prasun N.] NASA, Langley Res Ctr, Explort Syst Engn Branch, Hampton, VA 23665 USA. RP Desai, PN (reprint author), NASA, Langley Res Ctr, Explort Syst Engn Branch, Hampton, VA 23665 USA. NR 11 TC 8 Z9 12 U1 0 U2 4 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 2007 VL 55 IS 3 BP 311 EP 323 PG 13 WC Engineering, Aerospace SC Engineering GA 297LH UT WOS:000255617700003 ER PT J AU Sassen, K Wang, L Starr, DO Comstock, JM Quante, M AF Sassen, Kenneth Wang, Likun Starr, David O'C. Comstock, Jennifer M. Quante, Markus TI A midlatitude cirrus cloud climatology from the facility for atmospheric remote sensing. part V: Cloud structural properties SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INERTIA-GRAVITY WAVES; MICROPHYSICAL PROPERTIES; RADIATIVE PROPERTIES; RADAR OBSERVATIONS; FIRE; TURBULENCE; MESOSCALE; LIDAR; AIRCRAFT; INHOMOGENEITY AB In this fifth of a series of papers describing the extended-time high cloud observation program from the University of Utah Facility for Atmospheric Remote Sensing, the structural properties of cirrus clouds over Salt Lake City, Utah, are examined. Wavelet analysis is applied to a 10-yr record of cirrus cloud ruby (0.694 mu m) lidar backscatter data as a function of cloud height in order to study the presence of periodic cloud structures, such as the signatures of Kelvin-Helmholtz instabilities, cirrus mammata, and uncinus cells (all with length scales of similar to 1-10 km), as well as mesoscale cloud organizations generally believed to be induced by gravity waves. About 8.4% of the data display structures after passing a 95% confidence level test, but an 80% confidence level, which seems better able to resolve structures spread over long periods, yields 16.4%. The amount of identified cloud structures does not change significantly with length scale from 0.2 to 200 km, although the frequency of mesoscale cloud structures tends to increase as length scales increase. The middle-to-lower portion of cirrus clouds contains the most identified cloud structures, which seems related to the mesoscale organization of fall streaks from cloud-top-generating cells. The variability of cirrus cloud optical depth tau (defined by the standard deviation over mean tau) derived from a combined lidar and infrared radiometer (LIRAD) analysis is shown to be largely independent of tau. Because visual examination of the lidar displays also indicates that few cirrus layers can be considered horizontally homogeneous over our typical 3-h lidar data collection period, the authors conclude that the clouds in their sample are inherently inhomogeneous even though most cirrus structures are not revealed as periodic by wavelet analysis. C1 Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK 99775 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sassen, K (reprint author), Univ Alaska Fairbanks, Inst Geophys, 903 Koyukuk Dr, Fairbanks, AK 99775 USA. EM ksassen@gi.alaska.edu RI Wang, Likun/B-7524-2008 OI Wang, Likun/0000-0001-5646-9746 NR 53 TC 9 Z9 9 U1 2 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD JUL PY 2007 VL 64 IS 7 BP 2483 EP 2501 DI 10.1175/JAS3949.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 194HN UT WOS:000248335400017 ER PT J AU Tao, WK AF Tao, Wei-Kuo TI Cloud resolving Modeling SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Review ID TROPICAL OCEANIC CONVECTION; 3-DIMENSIONAL NUMERICAL EXPERIMENTS; GENERAL-CIRCULATION MODEL; SUPERCOOLED LIQUID WATER; LARGE-SCALE ORGANIZATION; SEA-SURFACE TEMPERATURE; MM5 MESOSCALE MODEL; LONG-TERM BEHAVIOR; SOUTH CHINA SEA; TOGA COARE AB One of the most promising methods to test the representation of cloud processes used in climate models is to use observations together with cloud resolving models (CRMs). CRMs use more sophisticated and realistic representations of cloud microphysical processes, and they can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems (with sizes ranging from about 2-200 km). CRMs also allow for explicit interaction between clouds, outgoing longwave (cooling) and incoming solar (heating) radiation, and ocean and land surface processes. Observations are required to initialize CRMs and to validate their results. This paper provides a brief discussion and review of the main characteristics of CRMs as well as some of their major applications. These include the use of CRMs to improve our understanding of: (1) convective organization, (2) cloud temperature and water vapor budgets, and convective momentum transport, (3) diurnal variation of precipitation processes, (4) radiative-convective quasi-equilibrium states, (5) cloud-chemistry interaction, (6) aerosol-precipitation interaction, and (7) improving moist processes in large-scale models. In addition, current and future developments and applications of CRMs will be presented. C1 NASA, Goddard Space Flight Ctr, Lab Atmospher, Greenbelt, MD 20771 USA. RP Tao, WK (reprint author), NASA, Goddard Space Flight Ctr, Lab Atmospher, Code 613-1, Greenbelt, MD 20771 USA. EM tao@agnes.gsfc.nasa.gov NR 164 TC 19 Z9 20 U1 2 U2 7 PU METEOROLOGICAL SOC JPN PI TOKYO PA C/O JPN METEOROL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, 100-0004, JAPAN SN 0026-1165 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD JUL PY 2007 VL 85B BP 305 EP 330 DI 10.2151/jmsj.85B.305 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 211DR UT WOS:000249505000014 ER PT J AU Miller, SW Marotta, E AF Miller, Stephen W. Marotta, Ed TI Thermal modeling and testing of a nanosatellite's avionics board SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article; Proceedings Paper CT AIAA/ASME 9th Joint Thermophysics and Heat Transfer Conference CY JUN 05-08, 2006 CL San Francisco, CA SP AIAA, ASME AB A lumped-capacitance thermal model of an avionics board within the Miniature Autonomous Extravehicular Robotic Camera was developed to predict component temperatures. Subsequently, a thermal vacuum test was conducted to determine the board's measured thermophysical properties and validate temperature predictions. A functional prototype of the board was instrumented with 24 type-T thermocouples and placed in a thermal vacuum chamber. The board was then subjected to two power conditions while the temperature response was recorded. Analysis of the data shows that the measured values of the in-plane thermal conductivity are dominated by the dielectric material. Pretest analysis underpredicted the through-plane thermal conductivity by 63% and the in-plane thermal conductivity was overpredicted by approximately 740%. Additionally, the bulk emissivity of the board was determined using an average temperature of the thermocouples on the back side of the board. The emissivity calculated from measured temperature data, 0.95, was approximately 19% higher than the assumed emissivity used in pretest models, 0.80. Incorporation of the thermophysical properties based on measured data allows the updated model to predict temperatures of the LED board within an uncertainty of +/- 10 degrees C and to capture the transient response of the board with considerable accuracy. C1 NASA, Lyndon B Johnson Space Ctr, Thermal Design Branch, ES3, Houston, TX 77058 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Miller, SW (reprint author), NASA, Lyndon B Johnson Space Ctr, Thermal Design Branch, ES3, Houston, TX 77058 USA. EM stephen.w.miller@nasa.gov; emarotta@tamu.edu NR 6 TC 2 Z9 2 U1 2 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JUL-SEP PY 2007 VL 21 IS 3 BP 496 EP 504 DI 10.2514/1.26659 PG 9 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 193BM UT WOS:000248248400007 ER PT J AU Kandula, M Haddad, G AF Kandula, M. Haddad, G. TI Two-dimensional thermal boundary layer corrections for convective heat flux gauges SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article ID FLAT-PLATE; CALORIMETERS AB This work presents a computational fluid dynamics study of 2-D thermal boundary layer correction factors for convective heat flux gauges mounted in flat plate subjected to a surface temperature discontinuity with variable properties taken into account. A two-equation k-omega turbulence model is considered. Results are obtained for a wide range of Mach numbers (1-5), gauge radius ratio, and wall temperature discontinuity. Comparisons are made for correction factors with constant properties and variable properties. It is shown that the variable-property effects on the heat flux correction factors become significant. C1 NASA, Kennedy Space Ctr, Sierra Lobo Inc, Integrat Branch,Launch Serv Program, Kennedy Space Ctr, FL 32899 USA. RP Kandula, M (reprint author), NASA, Kennedy Space Ctr, Sierra Lobo Inc, Integrat Branch,Launch Serv Program, Kennedy Space Ctr, FL 32899 USA. NR 23 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 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JUL-SEP PY 2007 VL 21 IS 3 BP 543 EP 547 DI 10.2514/1.28840 PG 5 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 193BM UT WOS:000248248400013 ER PT J AU Suzen, YB Huang, PG Ashpis, DE Volino, RJ Corke, TC Thomas, FO Huang, J Lake, JP King, PI AF Suzen, Y. B. Huang, P. G. Ashpis, D. E. Volino, R. J. Corke, T. C. Thomas, F. O. Huang, J. Lake, J. P. King, P. I. TI A computational fluid dynamics study of transitional flows in low-pressure turbines under a wide range of operating conditions SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article ID INTERMITTENCY TRANSPORT-EQUATION; BOUNDARY-LAYERS; TURBULENCE; PREDICTIONS; SEPARATION; AIRFOIL AB A transport equation for the intermittency factor is employed to predict the transitional flows in low-pressure turbines. The intermittent behavior of the transitional flows is taken into account and incorporated into computations by modifying the eddy viscosity, mu(1), with the intermittency factor gamma. Turbulent quantities are predicted by using Menter's two-equation turbulence model (SST). The intermittency factor is obtained from a transport equation model which can produce both the experimentally observed streamwise variation of intermittency and a realistic profile in the cross stream direction. The model had been previously validated against low-pressure turbine experiments with success. In this paper the model is applied to predictions of three sets of recent low-pressure turbine experiments on the Pack B blade to further validate its predicting capabilities under various flow conditions. Comparisons of computational results with experimental data are provided. Overall, good agreement between the experimental data and computational results is obtained. The new model has been shown to have the capability of accurately predicting transitional flows under a wide range of low-pressure turbine conditions. C1 N Dakota State Univ, Dept Mech Engn & Appl Mech, Fargo, ND 58105 USA. Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. NASA, Glenn Res Ctr, ASME, Cleveland, OH 44135 USA. USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. Univ Notre Dame, Ctr Flow Phys & Control, Dept Aeronaut & Mech Engn, Notre Dame, IN 46556 USA. Air Force Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. RP Suzen, YB (reprint author), N Dakota State Univ, Dept Mech Engn & Appl Mech, Fargo, ND 58105 USA. RI Volino, Ralph/G-9293-2011; OI Ashpis, David/0000-0003-4193-6174 NR 30 TC 20 Z9 20 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0889-504X J9 J TURBOMACH JI J. Turbomach.-Trans. ASME PD JUL PY 2007 VL 129 IS 3 BP 527 EP 541 DI 10.1115/1.2218888 PG 15 WC Engineering, Mechanical SC Engineering GA 234QM UT WOS:000251178800011 ER PT J AU Tarazaga, PA Inman, DJ Wilkie, WK AF Tarazaga, Pablo A. Inman, Daniel J. Wilkie, W. Keats TI Control of a space rigidizable inflatable boom using macro-fiber composite actuators SO JOURNAL OF VIBRATION AND CONTROL LA English DT Article DE PPF; PVF; PAF; piezoelectric actuators ID SMART MATERIALS AB An experimental investigation of vibration testing and active control of a space rigidizable inflatable composite boom containing embedded piezoelectric composite actuators was conducted. Inflatable deployable space structures offer reduced mass, higher packaging efficiency, lower life cycle cost, simpler design with fewer parts, and higher deployment reliability for many large deployable spacecraft structures applications. Enhancing deployed precision and repeatability for these structures is an ongoing research area, in particular for rigidizable inflatable material systems. In this study, in situ vibration testing and active damping using piezoelectric macro-fiber composite actuators embedded within a typical space-rigidizable deployable composite boom are investigated The embedded macro-fiber composites are shown to be capable of surviving integration, packaging, deployment and thermal rigidization in vacuum, and subsequently operating at their full actuation capability. Positive position feedback controllers using accelerometer, laser vibrometer, and strain gage feedback signals are designed and experimentally evaluated. Velocity-proportional and acceleration-proportional controllers are shown to be capable of attenuating fundamental bending response significantly using only modest control authority (-23dB with 10% of available voltage). C1 Virginia Polytech Inst & State Univ, Ctr Intelligent Mat Syst & Struct, Blacksburg, VA 24061 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tarazaga, PA (reprint author), Virginia Polytech Inst & State Univ, Ctr Intelligent Mat Syst & Struct, 310 Durham Hall,MC 0261, Blacksburg, VA 24061 USA. EM ptarazag@vt.edu RI Tarazaga, Pablo/F-2461-2014 NR 24 TC 30 Z9 30 U1 0 U2 18 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1077-5463 J9 J VIB CONTROL JI J. Vib. Control PD JUL PY 2007 VL 13 IS 7 BP 935 EP 950 DI 10.1177/1077546307078757 PG 16 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 194VO UT WOS:000248372100005 ER PT J AU Moles, A Heintz, RA AF Moles, A. Heintz, R. A. TI Parasites of forage fishes in the vicinity of steller sea lion (Eumetopias Jubatus) habitat in alaska SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE Alaska; Aleutian islands; Corynosoma sp.; forage fish; parasites; Steller sea lions ID HELMINTH-PARASITES; DECIPIENS; PATHOLOGY; MAMMALS; DIET AB Fish serve as intermediate hosts for a number of larval parasites that have the potential of maturing in marine mammals such as Steller sea lions (Eumetopias jubatus). We examined the prevalence of parasites from 229 fish collected between March and July 2002 near two islands used by Steller sea lions in Southeast Alaska and island habitats in the Aleutian Islands. Sea lion populations have remained steady in Southeast Alaska but have been declining over the last 30 yr in the Aleutian Islands. Even though the fish samples near the Southeast Alaska haul-outs were composed of numerous small species of fish and the Aleutian Islands catch was dominated by juveniles of commercially harvested species, the parasite fauna was similar at all locations. Eleven of the 20 parasite taxa identified were in their larval stage in the fish hosts, several of which have been described from mammalian final hosts. Four species of parasite were more prevalent in Southeast Alaska fish samples, and seven parasite species including several larval forms capable of infecting marine mammals, were more prevalent in fish from the Aleutian Islands. Nevertheless, parasites available to Steller sea lions from common fish prey are not likely to be a major factor in the decline of this marine mammal species. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Juneau, AK 99801 USA. RP Moles, A (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, 11305 Glacier Highway, Juneau, AK 99801 USA. EM Adam.Moles@noaa.gov NR 30 TC 3 Z9 4 U1 1 U2 1 PU WILDLIFE DISEASE ASSOC, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 USA SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD JUL PY 2007 VL 43 IS 3 BP 366 EP 375 PG 10 WC Veterinary Sciences SC Veterinary Sciences GA 202RO UT WOS:000248921100005 PM 17699075 ER PT J AU Pfeiffer-Herbert, AS McManus, MA Raimondi, PT Chao, Y Chai, F AF Pfeiffer-Herbert, Anna S. McManus, Margaret A. Raimondi, Peter T. Chao, Yi Chai, Fei TI Dispersal of barnacle larvae along the central California coast: A modeling study SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID BALANUS-GLANDULA; INTERTIDAL BARNACLE; MONTEREY BAY; PACIFIC-OCEAN; RECRUITMENT; SETTLEMENT; POPULATIONS; TRANSPORT; FLOW; INVERTEBRATES AB To investigate the biological and physical mechanisms affecting larval dispersal, we embedded a model of Balanus glandula larval development and behavior into physical circulation fields of waters along the central California coast. Physical circulation fields were generated by a three- dimensional ocean circulation model with a horizontal resolution of 1.5 km and 20 topography- following layers in the vertical. The ocean circulation model was forced by air - sea fluxes derived from a mesoscale atmospheric model and assimilated temperature and salinity data from the Autonomous Ocean Sampling Network II experiment. An ecosystem model that calculated chlorophyll a ( a proxy for larval food concentration) was also coupled to the ocean circulation model. The coupled model of larval development, larval behavior, food concentration, and physical circulation was used to run simulations of larval dispersal. Simulation results predicted a greater return of larvae to the nearshore waters with relaxation circulation patterns than with upwelling. More larvae were supplied to the coast north of Monterey Bay than to the south, and larvae that successfully returned to the nearshore waters generally had limited dispersal distances. These modeling results agree with previous observations of B. glandula population dynamics in central California. C1 Univ Calif Santa Cruz, Ocean Sci Dept, Santa Cruz, CA 95064 USA. Univ Hawaii Manoa, Dept Oceanog, Honolulu, HI 96822 USA. Univ Calif Santa Cruz, Ctr Ocean Hlth, Long Marine Lab, Santa Cruz, CA 95060 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Maine, Sch Marine Sci, Orono, ME 04469 USA. RP Pfeiffer-Herbert, AS (reprint author), Univ Rhode Isl, Grad Sch Oceanog, S Ferry Rd, Narragansett, RI 02882 USA. EM annaph@gso.uri.edu NR 37 TC 20 Z9 20 U1 1 U2 12 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JUL PY 2007 VL 52 IS 4 BP 1559 EP 1569 DI 10.4319/lo.2007.52.4.1559 PG 11 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 192QB UT WOS:000248215800023 ER PT J AU Harting, AL Baker, JD Johanos, TC AF Harting, Albert L. Baker, Jason D. Johanos, Thea C. TI Reproductive patterns of the Hawaiian monk seal SO MARINE MAMMAL SCIENCE LA English DT Article DE Monachus schauinslandi; monk seal; Northwestern Hawaiian Islands; reproduction; fecundity; reproductive senescence; population modeling; sensitivity analysis ID NORTHERN FUR SEALS; MONACHUS-SCHAUINSLANDI; FOSTERING BEHAVIOR; AGE; MORTALITY; POPULATIONS; MAMMALS AB We evaluated reproductive patterns of the Hawaiian monk seal (Monachus schauinslandi) using a combination of fitted age-specific reproductive curves and analysis of reproductive patterns of individual females. We review the difficulties inherent in the acquisition and modeling of reproductive data with emphasis on the significance of reproductive senescence to populations with dissimilar age/sex compositions. Validation of the fitted reproductive parameters was accomplished by Monte Carlo sampling of parameter distributions to compare the expected number of pups with the observed production. Although the fitted reproductive functions appear to provide an acceptable fit to the raw reproductive data, we found that the fitted curves did a poor job of predicting the actual pup production in individual years because of high variability among years. To further verify, and elaborate on, the patterns in the pooled (multi-seal, and multi-year) rates, we examined attributes of the reproductive performance of individual seals. The attributes included age of primiparity, reproductive rates computed over several age ranges, and the relationship between reproductive performance and seal longevity. Analysis of individual seal patterns reinforced the conclusion that reproductive senescence is operative in monk seal populations. C1 Harting Biol Consulting, Bozeman, MT 59715 USA. NOAA, Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA. RP Harting, AL (reprint author), Harting Biol Consulting, 8898 Sandy Creek Lane, Bozeman, MT 59715 USA. EM harting@mcn.net NR 30 TC 13 Z9 15 U1 2 U2 27 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0824-0469 EI 1748-7692 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JUL PY 2007 VL 23 IS 3 BP 553 EP 573 DI 10.1111/j.1748-7692.2007.00136.x PG 21 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 178FF UT WOS:000247205900005 ER PT J AU Ushikubo, T Guan, Y Hiyagon, H Sugiura, N Leshin, LA AF Ushikubo, Takayuki Guan, Yunbin Hiyagon, Hajime Sugiura, Naoji Leshin, Laurie A. TI Cl-36, Al-26, and O isotopes in an Allende type B2CAI: Implications for multiple secondary alteration events in the early solar system SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID ALUMINUM-RICH INCLUSIONS; CARBONACEOUS CHONDRITES; REFRACTORY INCLUSIONS; EXTINCT CL-36; CA-RICH; METEORITE; CHONDRULES; CONDENSATION; NEBULA; SULFUR AB We measured Cl-36-S-36 and Al-26-Mg-26 systematics and O isotopes of secondary phases in a moderately altered type B2 CAI (CAI#2) from the Allende CV3 chondrite. CAI#2 has two distinct alteration domains: the anorthite-grossular (An-Grs) domain that mostly consists of anorthite and grossular, and the Na-rich domain that mostly consists of sodalite, anorthite, and Fe-bearing phases. Large S-36 excesses (up to similar to 400 parts per thousand) corresponding to an initial Cl-36/Cl-35 ratio of (1.4 +/- 0.3) x 10(-6) were observed in sodalite of the Na-rich domain, but no resolvable Mg-26 excesses were observed in anorthite and sodalite of the Na-rich domain (the initial Al-26/Al-27 ratio < 4.4 x 10(-7)). If we assume that the Cl-36-S-36 and the Al-26-Mg-26 systematics were closed simultaneously, the Cl-36/Cl-35 ratio would have to be on the order of similar to 10(-2) when CAIs were formed. In contrast to sodalite in Na-rich domain, significant 26Mg excesses (up to similar to 35 parts per thousand) corresponding to an initial Al-26/Al-27 ratio of (1.2 +/- 0.2) x 10(-5) were identified in anorthite of the An-Grs domain. The Al-26-Mg-26 systematics of secondary phases in CAI#2 suggest that CAIs experienced multiple alteration events. Some of the alteration processes occurred while Cl-36 (half-life is 0.3 Myr) and Al-26 (half-life is 0.72 Myr) were still alive, whereas others took place much later. Assuming that Al-26 was homogeneously distributed in the solar nebula, our study implies that alteration of CAIs occurred as early as within 1.5 Myr of CAI formation and as late as 5.7 Myr after. C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Univ Tokyo, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ushikubo, T (reprint author), Univ Wisconsin, Dept Geol & Geophys, 1215 W Dayton St, Madison, WI 53706 USA. EM ushi@geology.wisc.edu RI Sugiura, Naoji/A-1855-2009; HIYAGON, HAJIME/G-4879-2014 NR 40 TC 14 Z9 15 U1 2 U2 4 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL-AUG PY 2007 VL 42 IS 7-8 BP 1267 EP 1279 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 224UN UT WOS:000250472200015 ER PT J AU Kimura, Y Nuth, JA Chakpaborty, S Thiemens, MH AF Kimura, Yuki Nuth, Joseph A., III Chakpaborty, Subrata Thiemens, Mark H. TI Non-mass-dependent oxygen isotopic fractionation in smokes produced in an electrical discharge SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID SOLAR-SYSTEM; METEORITES; ANOMALIES; OZONE; O-2; GRAINS; NEBULA; CARBON AB We report the first production of non-mass-dependently fractionated silicate smokes from the gas phase at room temperature from a stream of silane and/or pentacarbonyl iron in a molecular hydrogen (or helium) flow mixed with molecular oxygen (or nitrous oxide). The smokes were formed at the Goddard Space Flight Center (GSFC) at total pressures of just under 100 Torr in an electrical discharge powered by a Tesla coil, were collected from the surfaces of the copper electrodes after each experiment and sent to the University of California at San Diego (UCSD) for oxygen isotopic analysis. Transmission electron microscopy studies of the smokes show that they grew in the gas phase rather than on the surfaces of the electrodes. We hypothesize at least two types of fractionation processes occurred during formation of the solids: a mass-dependent process that made isotopically lighter oxides compared to our initial oxygen gas composition followed by a mass-independent process that produced oxides enriched in (17)O and (18)O. The nnaximum Delta(17)O observed is +4.7 parts per thousand for an iron oxide produced in flowing hydrogen, using O(2) as the oxidant. More typical displacements are 1-2 parts per thousand above the equilibrium fractionation line. The chemical reaction mechanisms that yield these smokes are still under investigation. C1 NASA, Goddard Space Flight Ctr, Astrochem Lab, Greenbelt, MD 20771 USA. Univ Calif San Diego, Dept Chem & Biochem, La Jolla, CA 92093 USA. RP Nuth, JA (reprint author), Ritsumeikan Univ, Dept Phys, Lab Nano Struct Sci, 1-1-1 Nojihigashi, Shiga 5258577, Japan. EM Joseph.A.Nuth@nasa.gov RI Nuth, Joseph/E-7085-2012; Kimura, Yuki/J-9635-2014 OI Kimura, Yuki/0000-0002-9218-7663 NR 26 TC 8 Z9 8 U1 0 U2 3 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL-AUG PY 2007 VL 42 IS 7-8 BP 1429 EP 1439 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 224UN UT WOS:000250472200025 ER PT J AU Mendoza, C Seaton, MJ Buerger, P Bellorin, A Melendez, M Gonzalez, J Rodriguez, LS Delahaye, F Palacios, E Pradhan, AK Zeippen, CJ AF Mendoza, C. Seaton, M. J. Buerger, P. Bellorin, A. Melendez, M. Gonzalez, J. Rodriguez, L. S. Delahaye, F. Palacios, E. Pradhan, A. K. Zeippen, C. J. TI OPserver: interactive online computations of opacities and radiative accelerations SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE atomic processes; radiative transfer; stars : interior ID CHEMICAL-COMPOSITION; STELLAR ENVELOPES; NEUTRINO FLUXES; SOLAR; ABUNDANCES; OPAL; HELIOSEISMOLOGY; DISCREPANCY; STARS; SUN AB Codes to compute mean opacities and radiative accelerations for arbitrary chemical mixtures using the Opacity Project recently revised data have been restructured in a client-server architecture and transcribed as a subroutine library. This implementation increases efficiency in stellar modelling where element stratification due to diffusion processes is depth dependent, and thus requires repeated fast opacity re-estimates. Three user modes are provided to fit different computing environments, namely, a web browser, a local workstation and a distributed grid. C1 Catholic Univ Amer, Inst Astrophys & Computat Sci, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Explorat Univ Div, Greenbelt, MD 20771 USA. Inst Venezolano Invest Cient, Ctr Fis, Caracas 1020A, Venezuela. Univ Los Andes, Ctr Nacl Calcul Cientif, Merida 5101, Venezuela. UCL, Dept Phys & Astron, London WC1E 6BT, England. Ohio Supercomp Ctr, Columbus, OH 43212 USA. Cent Univ Venezuela, Fac Ciencias, Escuela Fis, Caracas 1020A, Venezuela. Univ Simon Bolivar, Dept Fis, Caracas 1080A, Venezuela. Univ Carabobo, Fac Ciencias & Tecnol, Escuela Computat, Valencia, Venezuela. Inst Venezolano Invest Cient, Ctr Quim, Caracas 1020A, Venezuela. Observ Paris, LUTH, F-92195 Meudon, France. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. RP Mendoza, C (reprint author), Catholic Univ Amer, Inst Astrophys & Computat Sci, Dept Phys, Washington, DC 20064 USA. EM claudio@ivic.ve NR 22 TC 23 Z9 23 U1 0 U2 2 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 JUL 1 PY 2007 VL 378 IS 3 BP 1031 EP 1035 DI 10.1111/j.1365-2966.2007.11837.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 193JN UT WOS:000248270400022 ER PT J AU Yamada, TJ Koster, RD Kanae, S Oki, T AF Yamada, Tomohito J. Koster, Randal D. Kanae, Shinjiro Oki, Taikan TI Estimation of predictability with a newly derived index to quantify similarity among ensemble members SO MONTHLY WEATHER REVIEW LA English DT Article ID ATMOSPHERE COUPLING EXPERIMENT; POTENTIAL PREDICTABILITY; GCM SIMULATIONS; LAND; PRECIPITATION; PREDICTION; FORECASTS; MODELS; GLACE; FLOW AB This study reveals the mathematical structure of a statistical index, Omega, that quantifies similarity among ensemble members in a weather forecast. Previous approaches for quantifying predictability estimate separately the phase and shape characteristics of a forecast ensemble. The diagnostic Omega, on the other hand, characterizes the similarity (across ensemble members) of both aspects together with a simple expression. The diagnostic Omega is thus more mathematically versatile than previous indices. C1 Univ Tokyo, Inst Ind Sci, Meguro Ku, Tokyo 1538505, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Res Inst Human & Nat, Kyoto, Japan. RP Yamada, TJ (reprint author), Univ Tokyo, Inst Ind Sci, Meguro Ku, 4-6-1 Komaba, Tokyo 1538505, Japan. EM tomohito@iis.u-tokyo.ac.jp RI Kanae, Shinjiro/E-5606-2010; Oki, Taikan/E-5778-2010; Koster, Randal/F-5881-2012 OI Kanae, Shinjiro/0000-0002-3176-4957; Oki, Taikan/0000-0003-4067-4678; Koster, Randal/0000-0001-6418-6383 NR 24 TC 12 Z9 12 U1 0 U2 0 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 JUL PY 2007 VL 135 IS 7 BP 2674 EP 2687 DI 10.1175/MWR3418.1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 192BL UT WOS:000248175600013 ER PT J AU Chepfer, H Chiriaco, M Vautard, R Spinhirne, J AF Chepfer, H. Chiriaco, M. Vautard, R. Spinhirne, J. TI Evaluation of MM5 optically thin clouds over Europe in fall using ICESat lidar spaceborne observations SO MONTHLY WEATHER REVIEW LA English DT Article ID RADIATION MEASUREMENT PROGRAM; CIRRUS CLOUDS; MESOSCALE MODEL; WATER-VAPOR; MICROPHYSICAL PROPERTIES; SINGLE-SCATTERING; HUMIDITY SENSORS; CRYSTAL SHAPES; CLIMATE; VALIDATION AB The description of clouds in mesoscale models has progressed significantly during recent years by improving microphysical schemes with more physical parameterizations deduced from observations. Recently, the first lidar in space, the Ice, Cloud, and Land Elevation Satellite (ICESat)/Geosciences Laser Altimeter System, has collected a valuable dataset that improves the knowledge of occurrence and macrophysical properties of clouds, and particularly high-altitude clouds, which are usually optically thin. This study evaluates the capability of the fifth-generation Pennsylvania State University-NCAR Mesoscale Model (MM5) to reproduce optically thin clouds using the ICESat October-November 2003 dataset. Initial and boundary conditions are prescribed from NCEP products and MM5 run over the European continent with a 40-km spatial resolution. Spaceborne lidar profiles are diagnosed from model outputs and compared with the observed ones at the same location and time. One month of simulations-observations comparisons shows that the model correctly reproduces cloud structures on average, but underestimates the thinnest clouds (by 0%-20%) and overestimates less thin clouds in the upper troposphere (altitude >6 km). The total low-level water cloud amount (altitude <6 km) appears fairly well reproduced, although the masking effect of higher clouds does not allow for a firm conclusion. The clouds are rarely simulated and observed simultaneously, 50% for high clouds and 20% for low clouds. The lack of high-altitude very thin clouds is possibly due to dry biases in the upper-troposphere humidity fields used to force the model. The overestimation of optically less thin cloud may be due to an overestimation of the cloud lifetime or water vapor supersaturation around ice clouds that is not taken into account in the model. When the upper troposphere and low warm clouds appear in the model at the same time and location as in the observations, they are optically too thick, likely because their water/ice content and particle concentration are overestimated simultaneously. C1 Univ Paris 06, LMD IPSL, Paris, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Chepfer, H (reprint author), Univ Paris 06, LMD IPSL, 4 Pl Jussieu, Paris, France. EM chepfer@lmd.polytechnique.fr NR 64 TC 9 Z9 9 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUL PY 2007 VL 135 IS 7 BP 2737 EP 2753 DI 10.1175/MWR3413.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 192BL UT WOS:000248175600017 ER PT J AU Bernard, C Aime, JP Marsaudon, S Levy, R Bonnot, AM Nguyen, C Mariolle, D Bertin, F Chabli, A AF Bernard, Charlotte Aime, Jean-Pierre Marsaudon, Sophie Levy, Raphael Bonnot, Anne Marie Nguyen, Cattien Mariolle, Denis Bertin, Francois Chabli, Amal TI Drying nano particles solution on an oscillating tip at an air liquid interface: what we can learn, what we can do SO NANOSCALE RESEARCH LETTERS LA English DT Review DE nanofluidics; nanoparticles; micromeniscus; nanomeniscus; dynamical mode of atomic force microcopy ID SCANNING PROBE MICROSCOPY; DROPS AB Evaporation of fluid at micro and nanometer scale may be used to self-assemble nanometre-sized particles in suspension. Evaporating process can be used to gently control flow in micro and nanofluidics, thus providing a potential mean to design a fine pattern onto a surface or to functionalize a nanoprobe tip. In this paper, we present an original experimental approach to explore this open and rather virgin domain. We use an oscillating tip at an air liquid interface with a controlled dipping depth of the tip within the range of the micrometer. Also, very small dipping depths of a few ten nanometers were achieved with multi walls carbon nanotubes glued at the tip apex. The liquid is an aqueous solution of functionalized nanoparticles diluted in water. Evaporation of water is the driving force determining the arrangement of nanoparticles on the tip. The results show various nanoparticles deposition patterns, from which the deposits can be classified in two categories. The type of deposit is shown to be strongly dependent on whether or not the triple line is pinned and of the peptide coating of the gold nanoparticle. In order to assess the classification, companion dynamical studies of nanomeniscus and related dissipation processes involved with thinning effects are presented. C1 [Bernard, Charlotte; Aime, Jean-Pierre; Marsaudon, Sophie] Univ Bordeaux 1, CPMOH, F-33405 Talence, France. [Levy, Raphael] Univ Liverpool, Ctr Nanoscale Sci, Liverpool L69 7ZB, Merseyside, England. [Levy, Raphael] Univ Liverpool, Dept Chem, Liverpool L69 7ZB, Merseyside, England. [Bonnot, Anne Marie] CNRS, Inst Neel, F-38042 Grenoble 9, France. [Nguyen, Cattien] NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. [Mariolle, Denis; Bertin, Francois; Chabli, Amal] MINATEC, CEA LETI, F-38054 Grenoble 9, France. RP Aime, JP (reprint author), Univ Bordeaux 1, CPMOH, 351 Cours Liberat, F-33405 Talence, France. EM jp.aime@cpmoh.u-bordeaux1.fr RI Levy, Raphael/D-1474-2009; Mariolle, Denis/E-5950-2010 OI Levy, Raphael/0000-0001-5728-0531; NR 21 TC 5 Z9 5 U1 1 U2 13 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1931-7573 J9 NANOSCALE RES LETT JI Nanoscale Res. Lett. PD JUL PY 2007 VL 2 IS 7 BP 309 EP 318 DI 10.1007/s11671-007-9065-5 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 269NG UT WOS:000253655200001 ER PT J AU Anderson, JD Campbell, JK Nieto, MM AF Anderson, John D. Campbell, James K. Nieto, Michael Martin TI The energy transfer process in planetary flybys SO NEW ASTRONOMY LA English DT Article DE planetary gravity assist; dynamical anomaly ID MASS ANOMALIES; GALILEO; GANYMEDE; SYSTEM AB We illustrate the energy transfer during planetary flybys as a function of time using a number of flight mission examples. The energy transfer process is rather more complicated than a monotonic increase (or decrease) of energy with time. It exhibits temporary maxima and minima with time which then partially moderate before the asymptotic condition is obtained. The energy transfer to angular momentum is exhibited by an approximate Jacobi constant for the system. We demonstrate this with flybys that have shown unexplained behaviors: (i) the possible onset of the "Pioneer anomaly" with the gravity assist of Pioneer 11 by Saturn to hyperbolic orbit (as well as the Pioneer 10 hyperbolic gravity assist by Jupiter) and (ii) the Earth flyby anomalies of small increases in energy in the geocentric system (Galileo-I, NEAR, and Rosetta, in addition discussing the Cassini and Messenger flybys). Perhaps some small, as yet unrecognized effect in the energy-transfer process can shed light oil these anomalies. (c) 2006 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Anderson, JD (reprint author), Global Aerosp Corp, 711 W Woodbury Rd Suite H, Altadena, CA 91001 USA. EM John.D.Anderson@gaerospace.com; jkcepc@yahoo.com; mmn@lanl.gov NR 33 TC 35 Z9 35 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1076 J9 NEW ASTRON JI New Astron. PD JUL PY 2007 VL 12 IS 5 BP 383 EP 397 DI 10.1016/j.newast.2006.11.004 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 152AY UT WOS:000245333800003 ER PT J AU Laird, JS Scheick, L Vizkelethy, G Mojarradi, MM Miyahira, T Chen, Y Blalock, B Greenwell, R Terry, S Doyle, B AF Laird, Jamie Stuart Scheick, Leif Vizkelethy, Gyorgy Mojarradi, Mohammad M. Miyahira, Tetsuo Chen, Yuan Blalock, Benjamin Greenwell, Robert Terry, Stephen Doyle, Barney TI Single event transient analysis of an SOI operational amplifier for use in low-temperature Martian exploration SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 10th International Conference on Nuclear Microprobe Technology and Applications held in Conjunction with the 2nd International Workshop on Proton Beam Writing CY JUL 09-14, 2006 CL Singapore, SINGAPORE DE silicon on insulator; operational amplifier; single event transient; CMOS AB The next generation of Martian rovers to be launched by Jet Propulsion Laboratory (JPL) are to examine polar regions where temperatures are extremely low and the absence of an earth-like atmosphere results in high levels of cosmic radiation at ground level. Cosmic rays lead to a plethora of radiation effects including Single Event Transients which can severely degrade microelectronic functionality. As such, a radiation-hardened, temperature compensated CMOS Single-on-insulator (SOI) Operational Amplifier has been designed for JPL by the University of Tennessee and fabricated by Honeywell using the SOI V process. SOI technology has been shown to be far less sensitive to transient effects than both bulk and epilayer Si. Broad beam heavy-ion tests at the University of Texas A&M using Kr and Xe beams of energy 25 MeV/amu were performed to ascertain the duration and severity of the SET for the op-amp configured for a low and high gain application. However, some ambiguity regarding the location of transient formation required the use of a focused MeV ion microbeam. A 36 MeV O6+ microbeam at the Sandia National Laboratory (SNL) was used to image and verify regions of particular concern. (c) 2007 Published by Elsevier B.V. C1 CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. RP Laird, JS (reprint author), CALTECH, Jet Prop Lab, NASA, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Jamie.S.Laird@jpl.nasa.gov RI Laird, Jamie/A-7683-2011 NR 7 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 2007 VL 260 IS 1 BP 281 EP 287 DI 10.1016/j.nimb.2007.02.035 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 193HK UT WOS:000248264900054 ER PT J AU Lehan, JP Hadjimichael, T Content, DA AF Lehan, John P. Hadjimichael, Theodore Content, David A. TI Simple method of aligning cylindrical air-spaced elements SO OPTICAL ENGINEERING LA English DT Article DE anamorphic optical systems; cylindrical optics; optical alignment AB simple method is found to align multielement cylindrical lenses. The method employs only equipment found in most optical shops: a precision flat mirror and a Fizeau interferometer. A combination of narrow reflection interferograms from the lens surfaces, combined with cat-eye double-pass interferograms, is employed to align the elements. (c) 2007 Society of Photo-Optical Instrumentation Engineers. C1 NASA, Goddard Space Flight Ctr, Ctr Res & Explorat Space Sci & Technol, Baltimore, MD 21250 USA. Univ Maryland, Dept Phys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Swales Aerosp, Beltsville, MD 20705 USA. RP Lehan, JP (reprint author), NASA, Goddard Space Flight Ctr, Ctr Res & Explorat Space Sci & Technol, 1000 Hilltop Circle, Baltimore, MD 21250 USA. EM Theodore.J.Hadjimichael.1@gsfc.nasa.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU SPIE-SOC PHOTOPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD JUL PY 2007 VL 46 IS 7 AR 070503 DI 10.1117/1.2750656 PG 3 WC Optics SC Optics GA 221BA UT WOS:000250200700004 ER PT J AU Potere, D Woodcock, CE Schneider, A Ozdogan, M Baccini, A AF Potere, David Woodcock, Curtis E. Schneider, Annemarie Ozdogan, Mutlu Baccini, Alessandro TI Patterns in forest clearing along the appalachian. trail corridor SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID REMOTELY-SENSED DATA; LAND-COVER DATA; UNITED-STATES; DATA SET; TM DATA; CLASSIFICATION; TRANSFORMATION; REFLECTANCE; ACCURACY; DATABASE AB Forest clearing in the vicinity of the Appalachian Trail National Park undermines the Trail's value as a wilderness retreat for millions of annual hikers. We estimate that, 75,000 hectares of forest were lost to clearing during the decade of the 1990s inside a 16 km-wide corridor centered on the Trail. This loss represents 2.45 percent of forests within 8 km of the 3,500 km-long trail, Managed forest harvests in northern New England accounted for 76.8 percent of forest clearing. The factor most closely related to forest clearing is land ownership: only 0.29 percent of protected forests were cleared, while unprotected and managed forests were cleared at rates of 2.05 percent and 4.03 percent, respectively. A combination of boosted decision tree classifiers, multitemporal Kouth-Thomas transforms and the GeoGover Landsat dataset enabled a single, un-funded analyst to rapidly map land-cover change at 28.5-meter resolution within a 3.8 million hectare study area that spanned 16 Landsat scenes. C1 Princeton Univ, Off Populat Res, Princeton, NJ 08544 USA. Boston Univ, Dept Geog & Environm, Boston, MA 02215 USA. Boston Univ, Ctr Remote Sensing, Boston, MA 02215 USA. Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Potere, D (reprint author), Princeton Univ, Off Populat Res, 207 Wallace Hall, Princeton, NJ 08544 USA. EM dpotere@princeton.edu OI Ozdogan, Mutlu/0000-0002-1707-3375 NR 33 TC 6 Z9 6 U1 0 U2 3 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 2007 VL 73 IS 7 BP 783 EP 791 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 210EA UT WOS:000249438300009 ER PT J AU Speer, KM Neudeck, PG Crimp, MA Burda, C Pirouz, P AF Speer, K. M. Neudeck, P. G. Crimp, M. A. Burda, C. Pirouz, P. TI Possible formation mechanisms for surface defects observed in heteroepitaxially grown 3C-SiC SO PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE LA English DT Article ID SILICON-CARBIDE AB p-n diodes were fabricated from 3C-SiC films heteroepitaxially grown atop on-axis, Si-face (0001) 4H-SiC mesa substrate arrays [P. G. Neudeck et al., Mater. Sci. Forum 433-436, 213 (2003); 527-529, 1335 (2006)]. Images taken by electroluminescence-based optical emission microscopy (ELOEM) and electron channelling contrast imaging (ECCI) revealed immobile linear features aligned along < 110 > directions; defects were expected on these particular devices, as the 3C films were grown on stepped 4H mesas. To explain the formation of these defects, we have used a procedure by which surface energies are calculated for terraces on a stepped 4H, Si-face surface to investigate their comparative stability; subsequently, we use energetic calculations to confirm the formation-and determine the orientation-of 3C nuclei on the more stable 4H terraces and to evaluate the nature of the coalescence of nuclei from neighbouring terraces. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. C1 Case Western Reserve Univ, Dept Mat Sci & Engn, Cleveland, OH 44106 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Michigan State Univ, Dept Chem Engn & Mat Sci, E Lansing, MI 48824 USA. Case Western Reserve Univ, Dept Chem, Cleveland, OH 44106 USA. RP Speer, KM (reprint author), Case Western Reserve Univ, Dept Mat Sci & Engn, 10900 Euclid Ave, Cleveland, OH 44106 USA. EM kms57@case.edu RI Burda, Clemens/C-5107-2008; Burda, Clemens/D-1933-2010 OI Burda, Clemens/0000-0002-7342-2840; NR 14 TC 9 Z9 9 U1 0 U2 11 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Mat. PD JUL PY 2007 VL 204 IS 7 BP 2216 EP 2221 DI 10.1002/pssa.200675446 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 193HC UT WOS:000248264100007 ER PT J AU Matsko, AB Strekalov, D Savchenkov, AA Maleki, L AF Matsko, Andrey B. Strekalov, Dmitry Savchenkov, Anatoliy A. Maleki, Lute TI Improving coherent atomic vapor optical buffers SO PHYSICAL REVIEW A LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; GROUP-VELOCITY; SLOW LIGHT; GAS; STORAGE; MEDIA AB We report on a theoretical study of the influence of incoherent optical pumping and beam profiling on slow light propagation in three-level atomic vapor. The pumping reduces the residual unwanted absorption of the signal while destroying the atomic coherence and increasing the group velocity of light. We show that the pumping enhances the resulting group delay for a certain range of parameters. We also examine changing the cross section of the beam of light along the propagation direction by, e.g., focusing the beam, for the purpose of maintaining the drive intensity to effectively counter its absorption. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Matsko, AB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Matsko, Andrey/A-1272-2007 NR 27 TC 1 Z9 1 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 2007 VL 76 IS 1 AR 013806 DI 10.1103/PhysRevA.76.013806 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 196ML UT WOS:000248486600173 ER PT J AU Malkova, N Ning, CZ AF Malkova, N. Ning, C. Z. TI Interplay between Tamm-like and Shockley-like surface states in photonic crystals SO PHYSICAL REVIEW B LA English DT Article ID WAVES; MEDIA AB The goal of this paper is to demonstrate that surface states in a defect chain embedded in a host photonic crystal can be viewed as an interplay between the Tamm-like and Shockley-like states. The defect chain with alternating strong and weak bonds is analyzed using an empirical tight-binding model and the finite difference time domain technique. We investigate how the spectrum of the structures changes with different termination of the chain. It is shown that under certain conditions the Tamm and Shockley states can coexist or can transform from one to the other. These important features allow for controlling the surface states in photonic crystals in frequency, location, and strength. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Arizona State Univ, Ctr Nanophoton, Arizona Inst NanoElect, Tempe, AZ 85287 USA. Arizona State Univ, Dept Elect Engn, Tempe, AZ 85287 USA. RP Malkova, N (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM nmalkova@hotmail.com; cning@asu.edu RI Ning, C. Z./D-4699-2009 OI Ning, C. Z./0000-0003-4583-8889 NR 22 TC 22 Z9 22 U1 0 U2 11 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 2007 VL 76 IS 4 AR 045305 DI 10.1103/PhysRevB.76.045305 PG 9 WC Physics, Condensed Matter SC Physics GA 197FM UT WOS:000248540000058 ER PT J AU Yanik, AA Klimeck, G Datta, S AF Yanik, Ahmet Ali Klimeck, Gerhard Datta, Supriyo TI Quantum transport with spin dephasing: A nonequlibrium Green's function approach SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC TUNNEL-JUNCTIONS; MAGNETORESISTANCE; INTERFACE; DEPENDENCE; SCATTERING; ELECTRODE; EQUATION; DEVICES; BARRIER; LAYER AB A quantum transport model incorporating spin scattering processes is presented using the nonequilibrium Green's function formalism within the self-consistent Born approximation. This model offers a unified approach by capturing the spin-flip scattering and the quantum effects simultaneously. A numerical implementation of the model is illustrated for magnetic tunnel junction devices with embedded magnetic impurity layers. This model seems to explain three experimentally observed features regarding the dependence of the junction magnetoresistances (JMRs) on the barrier thickness, barrier height, and number of magnetic impurities. It is shown that small variations in magnetic impurity spin states and concentrations could cause large deviations in JMRs. C1 Purdue Univ, Dept Phys, Network Computat Nanotechnol, W Lafayette, IN 47907 USA. Purdue Univ, Sch Elect & Comp Engn, Network Computat Nanotechnol, W Lafayette, IN 47907 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yanik, AA (reprint author), Purdue Univ, Dept Phys, Network Computat Nanotechnol, W Lafayette, IN 47907 USA. RI Yanik, Ahmet/F-9245-2011; Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 36 TC 21 Z9 21 U1 0 U2 3 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 2007 VL 76 IS 4 AR 045213 DI 10.1103/PhysRevB.76.045213 PG 11 WC Physics, Condensed Matter SC Physics GA 197FM UT WOS:000248540000045 ER PT J AU Abbott, B Abbott, R Adhikari, R Agresti, J Ajith, P Allen, B Amin, R Anderson, SB Anderson, WG Arain, M Araya, M Armandula, H Ashley, M Aston, S Aufmuth, P Aulbert, C Babak, S Ballmer, S Bantilan, H Barish, BC Barker, C Barker, D Barr, B Barriga, P Barton, MA Bayer, K Belczynski, K Betzwieser, J Beyersdorf, PT Bhawal, B Bilenko, IA Billingsley, G Biswas, R Black, E Blackburn, K Blackburn, L Blair, D Bland, B Bogenstahl, J Bogue, L Bork, R Boschi, V Bose, S Brady, PR Braginsky, VB Brau, JE Brinkmann, M Brooks, A Brown, DA Bullington, A Bunkowski, A Buonanno, A Burgamy, M Burmeister, O Busby, D Byer, RL Cadonati, L Cagnoli, G Camp, JB Cannizzo, J Cannon, K Cantley, CA Cao, J Cardenas, L Casey, MM Castaldi, G Cepeda, C Chalkey, E Charlton, P Chatterji, S Chelkowski, S Chen, Y Chiadini, F Chin, D Chin, E Chow, J Christensen, N Clark, J Cochrane, P Cokelaer, T Colacino, CN Coldwell, R Conte, R Cook, D Cruise, AM Cumming, A Dalrymple, J D'Ambrosio, E Danzmann, K Davies, G Debra, D Degallaix, J Degree, M Demma, T Dergachev, V Desai, S DeSalvo, R Dhurandhar, S Diaz, M Dickson, J Di Credico, A Diederichs, G Dietz, A Doomes, EE Drever, RWP Dumas, JC Dupuis, RJ Dwyer, JG Ehrens, P Espinoza, E Etzel, T Evans, M Evans, T Fairhurst, S Fan, Y Fazi, D Fejer, MM Finn, LS Fiumara, V Fotopoulos, N Franzen, A Franzen, KY Freise, A Frey, R Fricke, T Fritschel, P Frolov, VV Fyffe, M Galdi, V Garofoli, J Gholami, I Giaime, JA Giampanis, S Giardina, KD Goda, K Goetz, E Goggin, L Gonzalez, G Gossler, S Grant, A Gras, S Gray, C Gray, M Greenhalgh, J Gretarsson, AM Grosso, R Grote, H Grunewald, S Guenther, M Gustafson, R Hage, B Hamilton, WO Hammer, D Hanna, C Hanson, J Harms, J Harry, G Harstad, E Hayler, T Heefner, J Heng, IS Heptonstall, A Heurs, M Hewitson, M Hild, S Hirose, E Hoak, D Hosken, D Hough, J Howell, E Hoyland, D Huttner, SH Ingram, D Innerhofer, E Ito, M Itoh, Y Ivanov, A Jackrel, D Johnson, B Johnson, WW Jones, DI Jones, G Jones, R Ju, L Kalmus, P Kalogera, V Kasprzyk, D Katsavounidis, E Kawabe, K Kawamura, S Kawazoe, F Kells, W Keppel, DG Khalili, FY Kim, C King, P Kissel, JS Klimenko, S Kokeyama, K Kondrashov, V Kopparapu, RK Kozak, D Krishnan, B Kwee, P Lam, PK Landry, M Lantz, B Lazzarini, A Lee, B Lei, M Leiner, J Leonhardt, V Leonor, I Libbrecht, K Lindquist, P Lockerbie, NA Longo, M Lormand, M Lubinski, M Luck, H Machenschalk, B MacInnis, M Mageswaran, M Mailand, K Malec, M Mandic, V Marano, S Marka, S Markowitz, J Maros, E Martin, I Marx, JN Mason, K Matone, L Matta, V Mavalvala, N McCarthy, R McCaulley, BJ McClelland, DE McGuire, SC McHugh, M McKenzie, K McNabb, JWC McWilliams, S Meier, T Melissinos, A Mendell, G Mercer, RA Meshkov, S Messaritaki, E Messenger, CJ Meyers, D Mikhailov, E Miller, P Mitra, S Mitrofanov, VP Mitselmakher, G Mittleman, R Miyakawa, O Mohanty, S Moody, V Moreno, G Mossavi, K MowLowry, C Moylan, A Mudge, D Mueller, G Mukherjee, S Muller-Ebhardt, H Munch, J Murray, P Myers, E Myers, J Nash, T Nettles, D Newton, G Nishizawa, A Numata, K O'Reilly, B O'Shaughnessy, R Ottaway, DJ Overmier, H Owen, BJ Paik, HJ Pan, Y Papa, MA Parameshwaraiah, V Patel, P Pedraza, M Penn, S Pierro, V Pinto, IM Pitkin, M Pletsch, H Plissi, MV Postiglione, F Prix, R Quetschke, V Raab, F Rabeling, D Radkins, H Rahkola, R Rainer, N Rakhmanov, M Ramsunder, M Rawlins, K Ray-Majumder, S Re, V Rehbein, H Reid, S Reitze, DH Ribichini, L Riesen, R Riles, K Rivera, B Robertson, NA Robinson, C Robinson, EL Roddy, S Rodriguez, A Rogan, AM Rollins, J Romano, JD Romie, J Route, R Rowan, S Rudiger, A Ruet, L Russell, P Ryan, K Sakata, S Samidi, M de la Jordana, LS Sandberg, V Sannibale, V Saraf, S Sarin, P Sathyaprakash, BS Sato, S Saulson, PR Savage, R Savov, P Schediwy, S Schilling, R Schnabel, R Schofield, R Schutz, BF Schwinberg, P Scott, SM Searle, AC Sears, B Seifert, F Sellers, D Sengupta, AS Shawhan, P Shoemaker, DH Sibley, A Sidles, JA Siemens, X Sigg, D Sinha, S Sintes, AM Slagmolen, BJJ Slutsky, J Smith, JR Smith, MR Somiya, K Strain, KA Strom, DM Stuver, A Summerscales, TZ Sun, KX Sung, M Sutton, PJ Takahashi, H Tanner, DB Tarallo, M Taylor, R Taylor, R Thacker, J Thorne, KA Thorne, KS Thuring, A Tokmakov, KV Torres, C Torrie, C Traylor, G Trias, M Tyler, W Ugolini, D Ungarelli, C Urbanek, K Vahlbruch, H Vallisneri, M Van Den Broeck, C Varvella, M Vass, S Vecchio, A Veitch, J Veitch, P Villar, A Vorvick, C Vyachanin, SP Waldman, SJ Wallace, L Ward, H Ward, R Watts, K Weaver, J Webber, D Weber, A Weidner, A Weinert, M Weinstein, A Weiss, R Wen, S Wette, K Whelan, JT Whitbeck, DM Whitcomb, SE Whiting, BF Wilkinson, C Willems, PA Williams, L Willke, B Wilmut, I Winkler, W Wipf, CC Wise, S Wiseman, AG Woan, G Woods, D Wooley, R Worden, J Wu, W Yakushin, I Yamamoto, H Yan, Z Yoshida, S Yunes, N Zanolin, M Zhang, J Zhang, L Zhang, P Zhao, C Zotov, N Zucker, M zur Muhlen, H Zweizig, J AF Abbott, B. Abbott, R. Adhikari, R. Agresti, J. Ajith, P. Allen, B. Amin, R. Anderson, S. B. Anderson, W. G. Arain, M. Araya, M. Armandula, H. Ashley, M. Aston, S. Aufmuth, P. Aulbert, C. Babak, S. Ballmer, S. Bantilan, H. Barish, B. C. Barker, C. Barker, D. Barr, B. Barriga, P. Barton, M. A. Bayer, K. Belczynski, K. Betzwieser, J. Beyersdorf, P. T. Bhawal, B. Bilenko, I. A. Billingsley, G. Biswas, R. Black, E. Blackburn, K. Blackburn, L. Blair, D. Bland, B. Bogenstahl, J. Bogue, L. Bork, R. Boschi, V. Bose, S. Brady, P. R. Braginsky, V. B. Brau, J. E. Brinkmann, M. Brooks, A. Brown, D. A. Bullington, A. Bunkowski, A. Buonanno, A. Burgamy, M. Burmeister, O. Busby, D. Byer, R. L. Cadonati, L. Cagnoli, G. Camp, J. B. Cannizzo, J. Cannon, K. Cantley, C. A. Cao, J. Cardenas, L. Casey, M. M. Castaldi, G. Cepeda, C. Chalkey, E. Charlton, P. Chatterji, S. Chelkowski, S. Chen, Y. Chiadini, F. Chin, D. Chin, E. Chow, J. Christensen, N. Clark, J. Cochrane, P. Cokelaer, T. Colacino, C. N. Coldwell, R. Conte, R. Cook, D. Cruise, A. M. Cumming, A. Dalrymple, J. D'Ambrosio, E. Danzmann, K. Davies, G. DeBra, D. Degallaix, J. Degree, M. Demma, T. Dergachev, V. Desai, S. DeSalvo, R. Dhurandhar, S. Diaz, M. Dickson, J. Di Credico, A. Diederichs, G. Dietz, A. Doomes, E. E. Drever, R. W. P. Dumas, J.-C. Dupuis, R. J. Dwyer, J. G. Ehrens, P. Espinoza, E. Etzel, T. Evans, M. Evans, T. Fairhurst, S. Fan, Y. Fazi, D. Fejer, M. M. Finn, L. S. Fiumara, V. Fotopoulos, N. Franzen, A. Franzen, K. Y. Freise, A. Frey, R. Fricke, T. Fritschel, P. Frolov, V. V. Fyffe, M. Galdi, V. Garofoli, J. Gholami, I. Giaime, J. A. Giampanis, S. Giardina, K. D. Goda, K. Goetz, E. Goggin, L. Gonzalez, G. Gossler, S. Grant, A. Gras, S. Gray, C. Gray, M. Greenhalgh, J. Gretarsson, A. M. Grosso, R. Grote, H. Grunewald, S. Guenther, M. Gustafson, R. Hage, B. Hamilton, W. O. Hammer, D. Hanna, C. Hanson, J. Harms, J. Harry, G. Harstad, E. Hayler, T. Heefner, J. Heng, I. S. Heptonstall, A. Heurs, M. Hewitson, M. Hild, S. Hirose, E. Hoak, D. Hosken, D. Hough, J. Howell, E. Hoyland, D. Huttner, S. H. Ingram, D. Innerhofer, E. Ito, M. Itoh, Y. Ivanov, A. Jackrel, D. Johnson, B. Johnson, W. W. Jones, D. I. Jones, G. Jones, R. Ju, L. Kalmus, P. Kalogera, V. Kasprzyk, D. Katsavounidis, E. Kawabe, K. Kawamura, S. Kawazoe, F. Kells, W. Keppel, D. G. Khalili, F. Ya. Kim, C. King, P. Kissel, J. S. Klimenko, S. Kokeyama, K. Kondrashov, V. Kopparapu, R. K. Kozak, D. Krishnan, B. Kwee, P. Lam, P. K. Landry, M. Lantz, B. Lazzarini, A. Lee, B. Lei, M. Leiner, J. Leonhardt, V. Leonor, I. Libbrecht, K. Lindquist, P. Lockerbie, N. A. Longo, M. Lormand, M. Lubinski, M. Lueck, H. Machenschalk, B. MacInnis, M. Mageswaran, M. Mailand, K. Malec, M. Mandic, V. Marano, S. Marka, S. Markowitz, J. Maros, E. Martin, I. Marx, J. N. Mason, K. Matone, L. Matta, V. Mavalvala, N. McCarthy, R. McCaulley, B. J. McClelland, D. E. McGuire, S. C. McHugh, M. McKenzie, K. McNabb, J. W. C. McWilliams, S. Meier, T. Melissinos, A. Mendell, G. Mercer, R. A. Meshkov, S. Messaritaki, E. Messenger, C. J. Meyers, D. Mikhailov, E. Miller, P. Mitra, S. Mitrofanov, V. P. Mitselmakher, G. Mittleman, R. Miyakawa, O. Mohanty, S. Moody, V. Moreno, G. Mossavi, K. MowLowry, C. Moylan, A. Mudge, D. Mueller, G. Mukherjee, S. Mueller-Ebhardt, H. Munch, J. Murray, P. Myers, E. Myers, J. Nash, T. Nettles, D. Newton, G. Nishizawa, A. Numata, K. O'Reilly, B. O'Shaughnessy, R. Ottaway, D. J. Overmier, H. Owen, B. J. Paik, H.-J. Pan, Y. Papa, M. A. Parameshwaraiah, V. Patel, P. Pedraza, M. Penn, S. Pierro, V. Pinto, I. M. Pitkin, M. Pletsch, H. Plissi, M. V. Postiglione, F. Prix, R. Quetschke, V. Raab, F. Rabeling, D. Radkins, H. Rahkola, R. Rainer, N. Rakhmanov, M. Ramsunder, M. Rawlins, K. Ray-Majumder, S. Re, V. Rehbein, H. Reid, S. Reitze, D. H. Ribichini, L. Riesen, R. Riles, K. Rivera, B. Robertson, N. A. Robinson, C. Robinson, E. L. Roddy, S. Rodriguez, A. Rogan, A. M. Rollins, J. Romano, J. D. Romie, J. Route, R. Rowan, S. Ruediger, A. Ruet, L. Russell, P. Ryan, K. Sakata, S. Samidi, M. de la Jordana, L. Sancho Sandberg, V. Sannibale, V. Saraf, S. Sarin, P. Sathyaprakash, B. S. Sato, S. Saulson, P. R. Savage, R. Savov, P. Schediwy, S. Schilling, R. Schnabel, R. Schofield, R. Schutz, B. F. Schwinberg, P. Scott, S. M. Searle, A. C. Sears, B. Seifert, F. Sellers, D. Sengupta, A. S. Shawhan, P. Shoemaker, D. H. Sibley, A. Sidles, J. A. Siemens, X. Sigg, D. Sinha, S. Sintes, A. M. Slagmolen, B. J. J. Slutsky, J. Smith, J. R. Smith, M. R. Somiya, K. Strain, K. A. Strom, D. M. Stuver, A. Summerscales, T. Z. Sun, K.-X. Sung, M. Sutton, P. J. Takahashi, H. Tanner, D. B. Tarallo, M. Taylor, R. Taylor, R. Thacker, J. Thorne, K. A. Thorne, K. S. Thuering, A. Tokmakov, K. V. Torres, C. Torrie, C. Traylor, G. Trias, M. Tyler, W. Ugolini, D. Ungarelli, C. Urbanek, K. Vahlbruch, H. Vallisneri, M. Van Den Broeck, C. Varvella, M. Vass, S. Vecchio, A. Veitch, J. Veitch, P. Villar, A. Vorvick, C. Vyachanin, S. P. Waldman, S. J. Wallace, L. Ward, H. Ward, R. Watts, K. Weaver, J. Webber, D. Weber, A. Weidner, A. Weinert, M. Weinstein, A. Weiss, R. Wen, S. Wette, K. Whelan, J. T. Whitbeck, D. M. Whitcomb, S. E. Whiting, B. F. Wilkinson, C. Willems, P. A. Williams, L. Willke, B. Wilmut, I. Winkler, W. Wipf, C. C. Wise, S. Wiseman, A. G. Woan, G. Woods, D. Wooley, R. Worden, J. Wu, W. Yakushin, I. Yamamoto, H. Yan, Z. Yoshida, S. Yunes, N. Zanolin, M. Zhang, J. Zhang, L. Zhang, P. Zhao, C. Zotov, N. Zucker, M. zur Muehlen, H. Zweizig, J. CA LIGO Sci Collaboration ALLEGRO Collaboration TI First cross-correlation analysis of interferometric and resonant-bar gravitational-wave data for stochastic backgrounds SO PHYSICAL REVIEW D LA English DT Article ID NEUTRON-STAR FORMATION; COSMOLOGICAL DISTANCES; PHASE-TRANSITIONS; STRING COSMOLOGY; DETECTOR; RADIATION; LIGO; DEPENDENCE; SPECTRUM; SEARCH AB Data from the LIGO Livingston interferometer and the ALLEGRO resonant-bar detector, taken during LIGO's fourth science run, were examined for cross correlations indicative of a stochastic gravitational-wave background in the frequency range 850-950 Hz, with most of the sensitivity arising between 905 and 925 Hz. ALLEGRO was operated in three different orientations during the experiment to modulate the relative sign of gravitational-wave and environmental correlations. No statistically significant correlations were seen in any of the orientations, and the results were used to set a Bayesian 90% confidence level upper limit of Omega(gw)(f)<= 1.02, which corresponds to a gravitational-wave strain at 915 Hz of 1.5x10(-23) Hz(-1/2). In the traditional units of h(100)(2)Omega(gw)(f), this is a limit of 0.53, 2 orders of magnitude better than the previous direct limit at these frequencies. The method was also validated with successful extraction of simulated signals injected in hardware and software. C1 Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-30167 Hannover, Germany. Andrews Univ, Berrien Springs, MI 49104 USA. Australian Natl Univ, Canberra, ACT 0200, Australia. CALTECH, Pasadena, CA 91125 USA. CALTECH, CaRT, Pasadena, CA 91125 USA. Cardiff Univ, Cardiff CF24 3AA, S Glam, Wales. Carleton Coll, Northfield, MN 55057 USA. Charles Sturt Univ, Wagga Wagga, NSW 2678, Australia. Columbia Univ, New York, NY 10027 USA. Embry Riddle Aeronaut Univ, Prescott, AZ 86301 USA. Hobart & William Smith Coll, Geneva, NY 14456 USA. Interuniv Ctr Astron & Astrophys, Pune 411007, Maharashtra, India. CALTECH, LIGO, Pasadena, CA 91125 USA. LIGO Hanford Observ, Richland, WA 99352 USA. LIGO Livingston Observ, Livingston, LA 70754 USA. MIT, LIGO, Cambridge, MA 02139 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Loyola Univ, New Orleans, LA 70118 USA. Moscow MV Lomonosov State Univ, Moscow 119992, Russia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Astron Observ, Tokyo 1818588, Japan. Northwestern Univ, Evanston, IL 60208 USA. Rochester Inst Technol, Rochester, NY 14623 USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. San Jose State Univ, San Jose, CA 95192 USA. SE Louisiana Univ, Hammond, LA 70402 USA. So Univ, Baton Rouge, LA 70813 USA. A&M Coll, Baton Rouge, LA 70813 USA. Stanford Univ, Stanford, CA 94305 USA. Syracuse Univ, Syracuse, NY 13244 USA. Penn State Univ, University Pk, PA 16802 USA. Univ Texas, Brownsville, TX 78520 USA. Texas Southmost Coll, Brownsville, TX 78520 USA. Trinity Univ, San Antonio, TX 78212 USA. Univ Illes Balears, E-07122 Palma de Mallorca, Spain. Leibniz Univ Hannover, D-30167 Hannover, Germany. Univ Adelaide, Adelaide, SA 5005, Australia. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Univ Florida, Gainesville, FL 32611 USA. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Univ Maryland, College Pk, MD 20742 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Rochester, Rochester, NY 14627 USA. Univ Salerno, I-84084 Salerno, Italy. Univ Sannio Benevento, I-82100 Benevento, Italy. Univ Southampton, Southampton SO17 1BJ, Hants, England. Univ Strathclyde, Glasgow G1 1XQ, Lanark, Scotland. Univ Washington, Seattle, WA 98195 USA. Univ Western Australia, Crawley 6009, Australia. Univ Wisconsin, Milwaukee, WI 53201 USA. Washington State Univ, Pullman, WA 99164 USA. RP Abbott, B (reprint author), Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. RI Howell, Eric/H-5072-2014; Ward, Robert/I-8032-2014; Khalili, Farit/D-8113-2012; Chiadini, Francesco/E-1812-2015; Vecchio, Alberto/F-8310-2015; Mow-Lowry, Conor/F-8843-2015; Ottaway, David/J-5908-2015; Postiglione, Fabio/O-4744-2015; Messaritaki, Eirini/D-7393-2016; Tarallo, Marco/B-2096-2012; Sigg, Daniel/I-4308-2015; Pinto, Innocenzo/L-3520-2016; Harms, Jan/J-4359-2012; Chow, Jong/A-3183-2008; Frey, Raymond/E-2830-2016; Kawabe, Keita/G-9840-2011; Finn, Lee Samuel/A-3452-2009; Agresti, Juri/G-8168-2012; Mitrofanov, Valery/D-8501-2012; Bilenko, Igor/D-5172-2012; Allen, Bruce/K-2327-2012; Chen, Yanbei/A-2604-2013; Barker, David/A-5671-2013; Ju, Li/C-2623-2013; Pitkin, Matthew/I-3802-2013; Schutz, Bernard/B-1504-2010; Sylvestre, Julien/A-8610-2009; Vyatchanin, Sergey/J-2238-2012; Strain, Kenneth/D-5236-2011; Raab, Frederick/E-2222-2011; Lueck, Harald/F-7100-2011; Kawazoe, Fumiko/F-7700-2011; zhao, chunnong/A-1373-2008; Barriga, Pablo/A-3929-2008; Lam, Ping Koy/A-5276-2008; Galdi, Vincenzo/B-1670-2008; McClelland, David/E-6765-2010; Martin, Iain/A-2445-2010; Hild, Stefan/A-3864-2010; Casey, Morag/C-9703-2010; Rowan, Sheila/E-3032-2010; Freise, Andreas/F-8892-2011 OI Stuver, Amber/0000-0003-0324-5735; Nishizawa, Atsushi/0000-0003-3562-0990; Zweizig, John/0000-0002-1521-3397; O'Shaughnessy, Richard/0000-0001-5832-8517; Aulbert, Carsten/0000-0002-1481-8319; Howell, Eric/0000-0001-7891-2817; LONGO, Maurizio/0000-0001-8325-4003; Pierro, Vincenzo/0000-0002-6020-5521; Ward, Robert/0000-0001-5503-5241; Whelan, John/0000-0001-5710-6576; Fairhurst, Stephen/0000-0001-8480-1961; Boschi, Valerio/0000-0001-8665-2293; Pinto, Innocenzo M./0000-0002-2679-4457; Freise, Andreas/0000-0001-6586-9901; MATTA, VINCENZO/0000-0002-2046-4027; MARANO, Stefano/0000-0002-5307-0980; Whiting, Bernard F/0000-0002-8501-8669; Veitch, John/0000-0002-6508-0713; Papa, M.Alessandra/0000-0002-1007-5298; Chiadini, Francesco/0000-0002-9339-8622; Vecchio, Alberto/0000-0002-6254-1617; Postiglione, Fabio/0000-0003-0628-3796; Tarallo, Marco/0000-0001-5169-4987; Sigg, Daniel/0000-0003-4606-6526; Chow, Jong/0000-0002-2414-5402; Frey, Raymond/0000-0003-0341-2636; Finn, Lee Samuel/0000-0002-3937-0688; Agresti, Juri/0000-0001-6119-2470; Allen, Bruce/0000-0003-4285-6256; Pitkin, Matthew/0000-0003-4548-526X; Sylvestre, Julien/0000-0001-8136-4348; Strain, Kenneth/0000-0002-2066-5355; Lueck, Harald/0000-0001-9350-4846; Lam, Ping Koy/0000-0002-4421-601X; Galdi, Vincenzo/0000-0002-4796-3600; McClelland, David/0000-0001-6210-5842; NR 42 TC 34 Z9 34 U1 2 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 J9 PHYS REV D JI Phys. Rev. D PD JUL PY 2007 VL 76 IS 2 AR 022001 DI 10.1103/PhysRevD.76.022001 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 197HM UT WOS:000248545200002 ER PT J AU Ahn, EJ Bertone, G Merritt, D Zhang, PJ AF Ahn, Eun-Joo Bertone, Gianfranco Merritt, David Zhang, Pengjie TI Impact of astrophysical processes on the gamma-ray background from dark matter annihilations SO PHYSICAL REVIEW D LA English DT Article ID SUPERMASSIVE BLACK-HOLES; GALACTIC-CENTER; NEUTRALINO ANNIHILATION; CLUSTERS; GALAXIES; HALOES; EVOLUTION; DENSITY; CONSTRAINTS; LUMINOSITY AB We study the impact of astrophysical processes on the gamma-ray background produced by the annihilation of dark matter particles in cosmological halos, with particular attention to the consequences of the formation of supermassive black holes. In scenarios where these objects form adiabatically from the accretion of matter on small seeds, dark matter is first compressed into very dense "spikes," then its density progressively decreases due to annihilations and scattering off of stellar cusps. With respect to previous analyses, based on nonevolving halos, the predicted annihilation signal is higher and significantly distorted at low energies, reflecting the large contribution to the total flux from unevolved spikes at high redshifts. The peculiar spectral feature arising from the specific redshift distribution of the signal, would discriminate the proposed scenario from more conventional astrophysical explanations. We discuss how this affects the prospects for detection and demonstrate that the gamma-ray background from dark matter (DM) annihilations might be detectable even in the absence of a signal from the Galactic center. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA. NASA, Fermilab Theoret Astrophys Grp, Batavia, IL USA. Univ Delaware, Dept Phys & Astron, Bartol Res Inst, Delaware, OH USA. Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Chinese Acad Sci, Shanghai Astron Observ, Shanghai, Peoples R China. RP Ahn, EJ (reprint author), Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. RI ZHANG, PENGJIE/O-2825-2015 NR 69 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 1550-7998 J9 PHYS REV D JI Phys. Rev. D PD JUL PY 2007 VL 76 IS 2 AR 023517 DI 10.1103/PhysRevD.76.023517 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 197HM UT WOS:000248545200026 ER PT J AU Kelly, BJ Tichy, W Campanelli, M Whiting, BF AF Kelly, B. J. Tichy, W. Campanelli, M. Whiting, B. F. TI Black-hole puncture initial data with realistic gravitational wave content SO PHYSICAL REVIEW D LA English DT Article ID COMPACT BINARIES; CANONICAL FORMALISM; RADIATION; ORDER; SIMULATIONS; EVOLUTION; ADM AB We present improved post-Newtonian-inspired initial data for nonspinning black-hole binaries, suitable for numerical evolution with punctures. We revisit the work of Tichy et al. [W. Tichy, B. Brugmann, M. Campanelli, and P. Diener, Phys. Rev. D 67, 064008 (2003).], explicitly calculating the remaining integral terms. These terms improve accuracy in the far zone and, for the first time, include realistic gravitational waves in the initial data. We investigate the behavior of these data both at the center of mass and in the far zone, demonstrating agreement of the transverse-traceless parts of the new metric with quadrupole-approximation waveforms. These data can be used for numerical evolutions, enabling a direct connection between the merger waveforms and the post-Newtonian inspiral waveforms. C1 NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. Univ Texas, Ctr Gravitat Wave Astron, Dept Phys & Astron, Brownsville, TX 78520 USA. Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. Rochester Inst Technol, Sch Math Sci, Ctr Computat Relat & Gravitat, Rochester, NY 14623 USA. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. RP Kelly, BJ (reprint author), NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. RI Kelly, Bernard/G-7371-2011; OI Kelly, Bernard/0000-0002-3326-4454 NR 57 TC 34 Z9 34 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 JUL PY 2007 VL 76 IS 2 AR 024008 DI 10.1103/PhysRevD.76.024008 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 197HM UT WOS:000248545200034 ER PT J AU Akylas, E Langer, CA Kassinos, SC Demosthenous, E AF Akylas, E. Langer, C. A. Kassinos, S. C. Demosthenous, E. TI On the linear stability of turbulent plane strain flow in a rotating frame SO PHYSICS OF FLUIDS LA English DT Article ID RAPID-DISTORTION THEORY; HOMOGENEOUS TURBULENCE; SHEAR AB We apply inviscid rapid distortion theory to the limiting hyperbolic case of turbulent plain strain flow in a rotating frame and investigate the dependence of the evolution of the turbulent kinetic energy on the frame rotation rate. We derive an analytical two-dimensional solution that, unlike previous oversimplified pressureless analyses, allows for an accurate approximation of the three-dimensional initially isotropic problem. From the analytical solutions, we determine the correct stability criterion for the evolution of the turbulent kinetic energy in this flow. Also, we calculate the asymptotic states of the turbulence, in terms of the normalized Reynolds stresses and structure dimensionality tensor components, which coincide with the exact three-dimensional numerical results. (c) 2007 American Institute of Physics. C1 Univ Cyprus, Dept Mech & Mfg Engn, CY-1678 Nicosia, Cyprus. Natl Observ Athens, Inst Environm Res, Athens, Greece. RP Kassinos, SC (reprint author), Stanford Univ, Ctr Turbulence Res, NASA Ames, Stanford, CA 94305 USA. EM kassinos@ucy.ac.cy RI Kassinos, Stavros/B-6404-2016; Akylas, Evangelos/E-4418-2016 OI Kassinos, Stavros/0000-0002-3501-3851; Akylas, Evangelos/0000-0002-2731-657X NR 21 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 EI 1089-7666 J9 PHYS FLUIDS JI Phys. Fluids PD JUL PY 2007 VL 19 IS 7 AR 075108 DI 10.1063/1.2750683 PG 11 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 196MG UT WOS:000248486100038 ER PT J AU Rame, E AF Rame, Enrique TI The stagnation point in Marangoni-thickened Landau-Levich type flows SO PHYSICS OF FLUIDS LA English DT Article ID CAPILLARY; BUBBLES; MOTION AB Experiments and analyses have shown that, when Marangoni stresses are present, the thickness of the Landau-Levich drawn-out film increases compared to the Marangoni-free classic case. As the Marangoni stress increases from zero, the stagnation point moves from where the interface height is three times the film thickness to infinity in the meniscus region when the film thickness is 2(2/3) times the classic Landau-Levich value. In this Brief Communication, we examine the fate of the stagnation point as the film thickness increases past this value, and the stagnation point moves into the interior of the fluid.(c) 2007 American Institute of Physics. C1 NASA, Glenn Res Ctr, Natl Ctr Space Explorat Res Fluids & Combust, Cleveland, OH 44135 USA. RP Rame, E (reprint author), NASA, Glenn Res Ctr, Natl Ctr Space Explorat Res Fluids & Combust, Mail Stop 110-3, Cleveland, OH 44135 USA. EM enrique.rame-1@nasa.gov NR 7 TC 7 Z9 7 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 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD JUL PY 2007 VL 19 IS 7 AR 078102 DI 10.1063/1.2745728 PG 4 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 196MG UT WOS:000248486100046 ER PT J AU Rauscher, BJ Fox, O Ferruit, P Hill, RJ Waczynski, A Wen, YT Xia-Serafino, W Mott, B Alexander, D Brambora, CK Derro, R Engler, C Garrison, MB Johnson, T Manthripragada, SS Marsh, JM Marshall, C Martineau, RJ Shakoorzadeh, KB Wilson, D Roher, WD Loose, M Wong-Anglin, S Zandian, M Ellis, T Howe, B Jurado, M Lee, G Nieznanski, J Wallis, P York, J Regan, MW Hall, DNB Hodapp, KW Boker, T De Marchi, G Jakobsen, P Strada, P AF Rauscher, Bernard J. Fox, Ori Ferruit, Pierre Hill, Robert J. Waczynski, Augustyn Wen, Yiting Xia-Serafino, Wei Mott, Brent Alexander, David Brambora, Clifford K. Derro, Rebecca Engler, Chuck Garrison, Matthew B. Johnson, Thomas Manthripragada, Sridhar S. Marsh, James M. Marshall, Cheryl Martineau, Robert J. Shakoorzadeh, Kamdin B. Wilson, Donna Roher, Wayne D. Loose, Markus Wong-Anglin, Selmer Zandian, Majid Ellis, Timothy Howe, Bryan Jurado, Miriam Lee, Ginn Nieznanski, John Wallis, Peter York, James Regan, Michael W. Hall, Donald N. B. Hodapp, Klaus W. Boker, Torsten De Marchi, Guido Jakobsen, Peter Strada, Paolo TI Detectors for the James Webb space telescope near-infrared spectrograph. I. Readout mode, noise model, and calibration considerations SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID ARRAYS AB We describe how the James Webb Space Telescope (JWST) Near-Infrared Spectrograph's (NIRSpec) detectors will be read out, and present a model of how noise scales with the number of multiple nondestructive reads sampling up the ramp. We believe that this noise model, which is validated using real and simulated test data, is applicable to most astronomical near-infrared instruments. We describe some nonideal behaviors that have been observed in engineering-grade NIRSpec detectors, and demonstrate that they are unlikely to affect NIRSpec sensitivity, operations, or calibration. These include a HAWAII-2RG reset anomaly and random telegraph noise (RTN). Using real test data, we show that the reset anomaly is ( 1) very nearly noiseless and ( 2) can be easily calibrated out. Likewise, we show that large-amplitude RTN affects only a small and fixed population of pixels. It can therefore be tracked using standard pixel operability maps. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. Univ Lyon, Lyon, France. Teledyne Imaging Sensors, Camarillo, CA USA. ITT Space Syst Div, Rochester, NY USA. Space Telescope Sci Inst, Baltimore, MD USA. Inst Astron, Hilo, HI USA. ESTEC, Div Astrophys, Noordwijk, Netherlands. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Univ Lyon 1, Observ Lyon, St Genis Laval, France. Ecole Normale Super Lyon, Ctr Rech Astrophys Lyon, UMR 5574, CNRS, F-69364 Lyon, France. RP Rauscher, BJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. EM Bernard.J.Rauscher@nasa.gov NR 19 TC 45 Z9 45 U1 0 U2 7 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 2007 VL 119 IS 857 BP 768 EP 786 DI 10.1086/520887 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 197LX UT WOS:000248558200006 ER PT J AU Zupanski, D Hou, AY Zhang, SQ Zupanski, M Kummerow, CD Cheung, SH AF Zupanski, Dusanka Hou, Arthur Y. Zhang, Sara Q. Zupanski, Milija Kummerow, Christian D. Cheung, Samson H. TI Applications of information theory in ensemble data assimilation SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE ensemble data assimilation; information theory; maximum likelihood ensemble filter; Kalman filter; 3D-Var ID TRANSFORM KALMAN FILTER; ATMOSPHERIC DATA ASSIMILATION; SEQUENTIAL DATA ASSIMILATION; PART I; MOISTURE OBSERVATIONS; THEORETICAL ASPECTS; MODEL; PREDICTABILITY; OCEANOGRAPHY; FORECASTS AB We apply information theory within an ensemble-based data assimilation approach and define information matrix in ensemble subspace. The information matrix in ensemble subspace employs a flow-dependent forecast error covariance and it is of relatively small dimensions (equal to the ensemble size). The information matrix in ensemble subspace can be directly linked to the information matrix typically used in non-ensemble-based data assimilation methods, such as the Kalman Filter (KF) and the three-dimensional variational (3D-Var) methods, which provides a framework for consistent comparisons of information measures between different data assimilation methods. We evaluate information measures, such as degrees of freedom for signal, within the Maximum Likelihood Ensemble Filter (MLEF) data assimilation approach and compare them with those obtained using the KF approach and the 3D-Var approach. We assimilate model-simulated observations and use the Goddard Earth Observing System Single Column Model (GEOS-5 SCM) as a dynamical forecast model. The experimental results demonstrate that the proposed framework is useful for comparing information measures obtained in different data assimilation approaches. These comparisons indicate that using a flow-dependent forecast error covariance matrix (e.g. as in the KF and the MLEF experiments) is fundamentally important for adequately describing prior knowledge about the true model state when calculating information measures of assimilated observations. We also demonstrate that data assimilation results obtained using the KF and the MLEF approach (when ensemble size is larger than 10 ensemble members) are superior to the results of the 3D-Var approach. Copyright (C) 2007 Royal Meteorological Society. C1 Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Davis, Davis, CA 95616 USA. RP Zupanski, D (reprint author), Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. EM zupanski@cira.colostate.edu RI Hou, Arthur/D-8578-2012 NR 62 TC 22 Z9 22 U1 1 U2 5 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JUL PY 2007 VL 133 IS 627 BP 1533 EP 1545 DI 10.1002/qj.123 PN B PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 228LZ UT WOS:000250732700015 ER PT J AU Hada, M Cucinotta, FA Gonda, SR Wu, HL AF Hada, Megumi Cucinotta, Francis A. Gonda, Steve R. Wu, Honglu TI mBAND analysis of chromosomal aberrations in human epithelial cells exposed to low- and high-LET radiation SO RADIATION RESEARCH LA English DT Article ID DENSELY IONIZING-RADIATION; BLOOD-LYMPHOCYTES; ALPHA-PARTICLES; MAMMALIAN-CELLS; PAST EXPOSURE; FISH ANALYSIS; INTERPHASE; INDUCTION; GENOME; INDIVIDUALS AB Energetic heavy ions pose a potential health risk to astronauts who have participated in extended space missions. High-LET radiation is much more effective than low-LET radiation in the induction of biological effects, including cell inactivation, genetic mutations, cataracts and cancer. Most of these biological end points are closely correlated with chromosomal damage, which can be used as a biomarker for radiation damage. Multicolor banding in situ hybridization (mBAND) has proven to be highly useful for the study of intrachromosomal aberrations, which have been suggested as a biomarker of exposure to high-LET radiation. To investigate biological signatures of radiation quality and the complexity of intrachromosomal aberrations, we exposed human epithelial cells in vitro to Cs-137 gamma rays or iron ions (600 MeV/nucleon) and collected chromosomes using a premature chromosome condensation technique. Aberrations in chromosome 3 were analyzed using mBAND probes. The results of our study confirmed the observation of a higher incidence of inversions for high-LET radiation. However, detailed analysis of the inversion type revealed that both iron ions and gamma rays induced a low incidence of simple inversions. Half of the inversions observed in the low-LET-irradiated samples were accompanied by other types of intrachromosome aberrations, but few inversions were accompanied by interchromosome aberrations. In contrast, iron ions induced a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosome exchanges. (c) 2007 by Radiation Research Society. C1 NASA, Lyndon B Johnson Space Ctr, Radiat Biophys Lab, Houston, TX 77058 USA. Univ Space Res Assoc, Houston, TX 77058 USA. RP Hada, M (reprint author), NASA, Lyndon B Johnson Space Ctr, Radiat Biophys Lab, Mail Code SK,2101 NASA Pkwy, Houston, TX 77058 USA. EM megumi.hadal@jsc.nasa.gov NR 43 TC 28 Z9 32 U1 3 U2 3 PU RADIATION RESEARCH SOC PI LAWRENCE PA 810 E TENTH STREET, LAWRENCE, KS 66044 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD JUL PY 2007 VL 168 IS 1 BP 98 EP 105 DI 10.1667/RR0759.1 PG 8 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 183YI UT WOS:000247607900006 PM 17722995 ER PT J AU Salas, MD AF Salas, Manuel D. TI The curious events leading to the theory of shock waves SO SHOCK WAVES LA English DT Article; Proceedings Paper CT 17th International Shock Interaction Symposium (ISIS 17) CY SEP 04-08, 2006 CL Rome, ITALY AB We review the history of the development of the modern theory of shock waves. Several attempts at an early-theory quickly collapsed for lack of foundations in mathematics and thermodynamics. It is not until the works of Rankine and later Hugoniot that a full theory is established. Rankine is the first to show that within the shock a non-adiabatic process must occur. Hugoniot showed that in the absence of viscosity and heat conduction conservation of energy implies conservation of entropy in smooth regions and a jump in entropy across a shock. Even after the theory is fully developed, old notions continue to pervade the literature well into the early part of the twentieth century. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Salas, MD (reprint author), NASA, Langley Res Ctr, Mail Stop 499, Hampton, VA 23681 USA. EM m.d.salas@nasa.gov NR 36 TC 6 Z9 7 U1 0 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 JUL PY 2007 VL 16 IS 6 BP 477 EP 487 DI 10.1007/s00193-007-0084-z PG 11 WC Mechanics SC Mechanics GA 189HB UT WOS:000247978900007 ER PT J AU Ireland, J AF Ireland, Jack TI Simulated annealing and bayesian posterior distribution analysis applied to spectral emission line fitting SO SOLAR PHYSICS LA English DT Article ID EXTREME-ULTRAVIOLET SPECTRA; SOLAR AB Spectral-line fitting problems are extremely common in all remote-sensing disciplines, solar physics included. Spectra in solar physics are frequently parameterized by using a model for the background and the emission lines, and various computational techniques are used to find values to the parameters given the data. However, the most commonly-used techniques, such as least-squares fitting, are highly dependent on the initial parameter values used and are therefore biased. In addition, these routines occasionally fail because of ill-conditioning. Simulated annealing and Bayesian posterior distribution analysis offer different approaches to finding parameter values through a directed, but random, search of the parameter space. The algorithms proposed here easily incorporate any other available information about the emission spectrum, which is shown to improve the fit. Example algorithms are given and their performance is compared to a least-squares algorithm for test data - a single emission line, a blended line, and very low signal-to-noise-ratio data. It is found that the algorithms proposed here perform at least as well or better than standard fitting practices, particularly in the case of very low signal-to-noise ratio data. A hybrid simulated annealing and Bayesian posterior algorithm is used to analyze a Mg x line contaminated by an O IV triplet, as observed by the Coronal Diagnostic Spectrometer onboard SOHO. The benefits of these algorithms are also discussed. C1 NASA, Goddard Space Flight Ctr, ADNET Syst Inc, Greenbelt, MD 20771 USA. RP Ireland, J (reprint author), NASA, Goddard Space Flight Ctr, ADNET Syst Inc, Mail Code 612-5, Greenbelt, MD 20771 USA. EM ireland@grace.nascom.nasa.gov NR 15 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JUL PY 2007 VL 243 IS 2 BP 237 EP 252 DI 10.1007/s11207-007-0358-8 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 215JC UT WOS:000249803600011 ER PT J AU Oliveira, PHF Artaxo, P Pires, C De Lucca, S Procopio, A Holben, B Schafer, J Cardoso, LF Wofsy, SC Rocha, HR AF Oliveira, Paulo H. F. Artaxo, Paulo Pires, Carlos De Lucca, Silvia Procopio, Aline Holben, Brent Schafer, Joel Cardoso, Luiz F. Wofsy, Steven C. Rocha, Humberto R. TI The effects of biomass burning aerosols and clouds on the CO2 flux in Amazonia SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article; Proceedings Paper CT 1st International Integrated Land Ecosystem Atmosphere Processes Study Science Conference ( iLEAPS) CY JAN, 2006 CL Boulder, CO ID SINGLE SCATTERING ALBEDO; CARBON-DIOXIDE UPTAKE; TROPICAL RAIN-FOREST; BRAZILIAN AMAZON; TERRESTRIAL ECOSYSTEMS; SOUTHWEST AMAZONIA; SOLAR IRRADIANCE; WATER-VAPOR; NET CARBON; ART. AB Aerosol particles associated with biomass burning emissions affect the surface radiative budget and net ecosystem exchange (NEE) over large areas in Amazonia during the dry season. We analysed CO2 fluxes as a function of aerosol loading for two forest sites in Amazonia as part of the LBA experiment. Aerosol optical thickness (AOT) measurements were made with AERONET sun photometers, and CO2 flux measurements were determined by eddy-correlation. The enhancement of the NEE varied with different aerosol loading, as well as cloud cover, solar elevation angles and other parameters. The AOT value with the strongest effect on the NEE in the FLONA-Tapajos site was 1.7, with an enhancement of the NEE of 11% compared with clear-sky conditions. In the RBJ site, the strongest effect was for AOT of 1.6 with an enhancement of 18% in the NEE. For values of AOT lager than 2.7, strong reduction on the NEE was observed due to the reduction in the total solar radiation. The enhancement in the NEE is attributed to the increase of diffuse versus direct solar radiation. Due to the fact that aerosols from biomass burning are present in most tropical areas, its effects on the global carbon budget could also be significant. C1 Univ Sao Paulo, Inst Fis, LFA, BR-05508900 Sao Paulo, Brazil. Univ Fed Rio de Janeiro, Dept Engn Bioquim, BR-21949900 Rio De Janeiro, Brazil. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Fundacao Univ Fed Rondonia, UNIR, Ji Parana, Brazil. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Sao Paulo, IAG, Dept Ciencias Atmosfer, BR-05508900 Sao Paulo, SP, Brazil. RP Oliveira, PHF (reprint author), Univ Sao Paulo, Inst Fis, LFA, Rua Matao Travessa R,187, BR-05508900 Sao Paulo, Brazil. EM pauloh@if.usp.br RI Procopio, Aline/L-7483-2013; Artaxo, Paulo/E-8874-2010 OI Procopio, Aline/0000-0002-2326-2500; Artaxo, Paulo/0000-0001-7754-3036 NR 46 TC 63 Z9 67 U1 2 U2 22 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD JUL PY 2007 VL 59 IS 3 BP 338 EP 349 DI 10.1111/j.1600-0889.2007.00270.x PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177TB UT WOS:000247174300002 ER PT J AU Pieterse, G Bleeker, A Vermeulen, AT Wu, Y Erisman, JW AF Pieterse, G. Bleeker, A. Vermeulen, A. T. Wu, Y. Erisman, J. W. TI High resolution modelling of atmosphere-canopy exchange of acidifying and eutrophying components and carbon dioxide for European forests SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article; Proceedings Paper CT 1st International Integrated Land Ecosystem Atmosphere Processes Study Science Conference ( iLEAPS) CY JAN, 2006 CL Boulder, CO ID DRY DEPOSITION MODEL; AIR-POLLUTION MODEL; SULFUR-DIOXIDE; BOUNDARY-LAYER; STOMATAL CONDUCTANCE; ROUGHNESS LENGTHS; HEAT-FLUX; LAND; PARAMETERIZATION; LEAVES AB The Integrated Deposition Model (IDEM) was improved by incorporating a novel multilayer biochemical dry deposition module for gases. The aerosol and base cation deposition module was adopted from IDEM. For evaluation of primary and ecosystem productivity, carbon respiration schemes were included. The resulting Framework for Atmosphere- Canopy Exchange Modelling (FACEM) was then evaluated by the case studies presented here. First, results for deposition of SOx, NOy and NHx were compared with site observations, showing correlations of up to R-2 = 0.60. Applicability for grid deposition calculations for these compounds was then evaluated for Europe. The model was clearly able to reproduce the elevated deposition near the important emission areas in Europe. Next, we compared the modelled CO2 fluxes with measurements from 26 European sites. Correlations of up to R-2 = 0.81 indicate good performance. To evaluate grid performance, the 2003 European heat wave was studied in a final case study, resulting in convincing correspondence with the observed productivity anomalies. C1 Energy Res Inst Netherlands, NL-1755 ZG Petten, Netherlands. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Pieterse, G (reprint author), Energy Res Inst Netherlands, Westerduinweg 3, NL-1755 ZG Petten, Netherlands. EM g.pieterse@phys.uu.nl RI Bleeker, Albert/A-1786-2010; Erisman, Jan Willem/C-6900-2008; Vermeulen, Alex/A-2867-2015 OI Vermeulen, Alex/0000-0002-8158-8787 NR 65 TC 17 Z9 17 U1 0 U2 2 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD JUL PY 2007 VL 59 IS 3 BP 412 EP 424 DI 10.1111/j.1600-0889.2007.00266.x PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177TB UT WOS:000247174300010 ER PT J AU Antoniotti, P Carra, C Maranzana, A Tonachini, G AF Antoniotti, Paola Carra, Claudio Maranzana, Andrea Tonachini, Glauco TI Germyl mesolytic dissociations in the allylgermane and penta-2,4-dienylgermane radical anions. A theoretical study SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Article DE mesolysis; radical anions; allylgermane; pentadienylgermane; activation ID INTRAMOLECULAR ELECTRON-TRANSFER; STANDARD DIFFUSE FUNCTIONS; MOLECULAR-ORBITAL METHODS; BODY PERTURBATION-THEORY; COUPLED-CLUSTER SINGLES; C-C BONDS; ELECTROCHEMICAL REDUCTION; CARTESIAN GAUSSIANS; LEAVING GROUP; BASIS SETS AB In CH2CHCH2-GeH3- two stable structures have a trigonal bipyramidal arrangement around Ge, with the extra electron in equatorial (tbp eq) or axial (tbp ax) position. In CH2(CH)(3)CH2-GeH3- only tbp ax is found, while a second structure with a tetrahedral germyl group has the extra electron on the conjugated pi system. C-Ge bond cleavage yields allyl/pentadienyl radicals plus germide. Both dissociation reactions require 4-6 kcal mol(-1), less than the analogous C and Si systems (ca. 30 and 14 kcal mol(-1), respectively). Fragmentation is dramatically activated with respect to homolysis in the corresponding neutrals. The wave-function is dominated by one single configuration at all distances, in contrast to homolytic cleavage, in which two configurations are important. C-Ge bond dissociation is at variance also with heterolysis, due to spin recoupling of one of the C-Ge bond electrons with the originally unpaired electron. C1 Univ Turin, Dipartimento Chim Gen & Organ Applicata, I-10125 Turin, Italy. NASA JSC Space Radiat Hlth Project, Houston, TX 77058 USA. RP Tonachini, G (reprint author), Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. EM glauco.tonachini@unito.it OI TONACHINI, Glauco/0000-0001-7845-1475 NR 89 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1432-881X J9 THEOR CHEM ACC JI Theor. Chem. Acc. PD JUL PY 2007 VL 118 IS 1 BP 253 EP 264 DI 10.1007/s00214-007-0318-2 PG 12 WC Chemistry, Physical SC Chemistry GA 186OA UT WOS:000247786800027 ER PT J AU Zaretsky, EV Poplawski, JV Root, LE AF Zaretsky, Erwin V. Poplawski, Joseph V. Root, Lawrence E. TI Reexamination of ball-race conformity effects on ball bearing life SO TRIBOLOGY TRANSACTIONS LA English DT Article DE rolling-element bearings; bearing life; race conformity; bearing geometry ID FATIGUE LIFE AB G. Lundberg and A. Palmgren, in 1947, established the primary relation between rolling-element bearing geometry and bearing life. Their analysis of ball and roller bearings did not consider the life of the bearing's set of rolling elements independent of race life. The analysis in this report considers the life of the ball set as well as the respective lives of the races to reassess the effect of ball-race conformity on ball bearing life. The related changes in ball bearing life are incorporated in life factors that can be used to modify the bearing predicted life using the Lundberg-Palmgren equations and the ANSI/ABMA and ISO Standards. Two simple algebraic relationships were established to calculate life factors LFc to determine the effect of inner- and outer-race conformity combinations on bearing L-10 life for deep-groove and angular-contact ball bearings, respectively. Depending on the bearing type and series as well as conformity combinations, the calculated life for deep-groove ball bearings can be over 40 percent less than that calculated by the Lundberg-Palmgren equations. For angular-contact ball bearings, the life can vary between +16 and -39% from that calculated by the Lundberg-Palmgren equations. Comparing the two ball bearing types, the life factors LFc for the deep-groove bearings can be as much as 40% lower than that for angular-contact ball bearings. The use of a fatigue limit from either the program ASMELIFE or the proposed ISO 281:2006 standard can significantly overpredict bearing life over a range of normal operating Hertz stresses, which can result in the selection of undersized bearings for a particular application. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. JV Poplawski & Assoc, Bethlehem, PA 18018 USA. Lawrence E Root, Lebanon, NH 03766 USA. RP Zaretsky, EV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 29 TC 7 Z9 9 U1 0 U2 3 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 2007 VL 50 IS 3 BP 336 EP 349 DI 10.1080/10402000701429147 PG 14 WC Engineering, Mechanical SC Engineering GA 195GN UT WOS:000248400600006 ER PT J AU Leahy, LV Anderson, TL Eck, TF Bergstrom, RW AF Leahy, L. V. Anderson, T. L. Eck, T. F. Bergstrom, R. W. TI A synthesis of single scattering albedo of biomass burning aerosol over southern Africa during SAFARI 2000 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SKY RADIANCE MEASUREMENTS; GROUND-BASED OBSERVATIONS; OPTICAL-PROPERTIES; SIZE DISTRIBUTIONS; LIGHT-ABSORPTION; DRY SEASON; IN-SITU; AERONET; SUN; VARIABILITY AB We present a synthesis of single scattering albedo for biomass burning aerosol from the SAFARI 2000 field campaign. Values at 550 nm were derived from three methods: airborne in situ measurements of aerosol scattering and absorption; airborne flux radiometry; and ground-based sun-photometer/radiometer retrievals from AERONET. Collocated comparisons indicate that uncertainties are well understood for all three methods. The new ( Version 2) AERONET retrieval gives substantially lower single scattering albedo over bright surfaces, and the comparisons herein represent the first independent check of this retrieval. Combined in situ and AERONET data yield a regional value of 0.85 +/- 0.02 ( mean and total uncertainty), which we propose is representative of single scattering albedo for the Southern African region during the biomass burning season. This value agrees with the "highly absorbing smoke'' model used in MODIS aerosol retrievals, but indicates that many of the AeroCom models overestimate single scattering albedo for this region and season. C1 Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Bay Area Environm Res Inst, Sonoma, CA 95476 USA. RP Leahy, LV (reprint author), Univ Washington, Dept Atmospher Sci, Box 351640, Seattle, WA 98195 USA. EM lleahy@atmos.washington.edu RI ECK, THOMAS/D-7407-2012 NR 30 TC 36 Z9 36 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 30 PY 2007 VL 34 IS 12 AR L12814 DI 10.1029/2007GL029697 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 184ZW UT WOS:000247682100002 ER PT J AU Lau, KM Wu, HT AF Lau, K.-M. Wu, H.-T. TI Detecting trends in tropical rainfall characteristics, 1979-2003 SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE tropical rainfall; trend; extreme ID CLIMATE-CHANGE; PRECIPITATION; 20TH-CENTURY; CYCLE; GPCP; VARIABILITY; INTENSITY; OCEANS AB Analyses of two state-of-the-art, blended space-based and ground-based global rainfall data sets from the Global Precipitation Climatology Project (GPCP) and the Climate Prediction Center Merged Analysis Product (CMAP) reveal that there was a significant shift in the probability distribution functions of tropical rainfall during the period 1979-2003. This shift features a positive trend in the occurrence of heavy (top 10% by rain amount) and light (bottom 5%) rain events in the tropics during 1979-2003 and a negative trend in moderate (25-75%) rain events. These trends are consistent in both data sets and are in overall agreement with the Climate Research Unit's (CRU) gauge-only rainfall data over land. The relationships among the trends and the possible long-term changes in rainfall characteristics are discussed. Published in 2006 by John Wiley & Sons, Ltd. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Sci & Syst Applicat Inc, Lanham, MD USA. RP Lau, KM (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 613,Bldg 33,Rm C121, Greenbelt, MD 20771 USA. EM william.k.lau@nasa.gov RI Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 23 TC 55 Z9 59 U1 1 U2 11 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD JUN 30 PY 2007 VL 27 IS 8 BP 979 EP 988 DI 10.1002/joc.1454 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 187HL UT WOS:000247838200001 ER PT J AU Tarasick, DW Moran, MD Thompson, AM Carey-Smith, T Rochon, Y Bouchet, VS Gong, W Makar, PA Stroud, C Menard, S Crevier, LP Cousineau, S Pudykiewicz, JA Kallaur, A Moffet, R Menard, R Robichaud, A Cooper, OR Oltmans, SJ Witte, JC Forbes, G Johnson, BJ Merrill, J Moody, JL Morris, G Newchurch, MJ Schmidlin, FJ Joseph, E AF Tarasick, D. W. Moran, M. D. Thompson, A. M. Carey-Smith, T. Rochon, Y. Bouchet, V. S. Gong, W. Makar, P. A. Stroud, C. Menard, S. Crevier, L.-P. Cousineau, S. Pudykiewicz, J. A. Kallaur, A. Moffet, R. Menard, R. Robichaud, A. Cooper, O. R. Oltmans, S. J. Witte, J. C. Forbes, G. Johnson, B. J. Merrill, J. Moody, J. L. Morris, G. Newchurch, M. J. Schmidlin, F. J. Joseph, E. TI Comparison of Canadian air quality forecast models with tropospheric ozone profile measurements above midlatitude North America during the IONS/ICARTT campaign: Evidence for stratospheric input SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ORGANIC AEROSOL YIELDS; MULTISCALE GEM MODEL; BACKGROUND OZONE; UNITED-STATES; POTENTIAL VORTICITY; HIGH-LATITUDES; SURFACE AIR; TRANSPORT; BE-7; FLUX AB [1] During July and August, 2004, balloon-borne ozonesondes were released daily at 12 sites in the eastern USA and Canada, producing the largest single set of free tropospheric ozone measurements ever compiled for this region. At the same time, a number of air quality forecast models were run daily as part of a larger field experiment. In this paper, we compare these ozonesonde profiles with predicted ozone profiles from several versions of two of these forecast models, the Environment Canada CHRONOS and AURAMS models. We find that the models show considerable skill at predicting ozone in the planetary boundary layer and immediately above. Individual station biases are variable, but often small. Standard deviations of observation-forecast differences are large, however. Ozone variability in the models is somewhat higher than observed. Most strikingly, none of the model versions is able to reproduce the typical tropospheric ozone profile of increasing mixing ratio with altitude. Results from a sensitivity test suggest that the form of the ozone lateral boundary condition used by all model versions contributes significantly to the large ozone underpredictions in the middle and upper troposphere. The discrepancy could be reduced further by adding a downward flux of ozone from the model lid and by accounting for in situ production of ozone from lightning-generated NOx. C1 Environm Canada, Air Qual Res Div, Downsview, ON M3H 5T4, Canada. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Environm Canada, Meteorol Serv Canada, Air Qual Models Applicat Grp, Dorval, PQ H9P 1J3, Canada. Environm Canada, Meteorol Res Div, Dorval, PQ H9P 1J3, Canada. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Aeron Lab, Boulder, CO 80305 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. Meteorol Serv Canada, Halifax, NS B3J 2R7, Canada. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22993 USA. Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. Howard Univ, Dept Phys & Astron, Washington, DC 20059 USA. RP Tarasick, DW (reprint author), Environm Canada, Air Qual Res Div, Downsview, ON M3H 5T4, Canada. EM david.tarasick@ec.gc.ca RI Cooper, Owen/H-4875-2013; Thompson, Anne /C-3649-2014; OI Thompson, Anne /0000-0002-7829-0920; Tarasick, David/0000-0001-9869-0692 NR 70 TC 29 Z9 29 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 30 PY 2007 VL 112 IS D12 AR D12S22 DI 10.1029/2006JD007782 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 185AL UT WOS:000247683600001 ER PT J AU Brandon, EJ West, WC Smart, MC Whitcanack, LD Plett, GA AF Brandon, Erik J. West, William C. Smart, Marshall C. Whitcanack, Larry D. Plett, Gary A. TI Extending the low temperature operational limit of double-layer capacitors SO JOURNAL OF POWER SOURCES LA English DT Article DE supercapacitors; electrochemical capacitors; double-layer capacitors; low temperature energy storage AB This work describes the design and testing of organic electrolyte systems that extend the low temperature operational limit of double-layer capacitors (also known as supercapacitors) beyond that of typical commercially available components. Electrolytes were based on a tetraethylammonium tetrafluoroborate/acetonitrile system, modified with low melting co-solvents (such as formates, esters and cyclic ethers) to enable charging and discharging of test cells to as low as -75 degrees C. Cell capacitance exhibited little dependence on the electrolyte salt concentration or the nature of the co-solvent used, however, both variables strongly influenced the cell equivalent series resistance (ESR). Minimizing the increase in ESR posed the greatest design challenge, which limited realistic operation of these test cells to -55 degrees C (still improved relative to the typical rated limit of -40 degrees C for commercially available non-aqueous cells). (C) 2007 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Brandon, EJ (reprint author), CALTECH, Jet Propuls Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM erik.j.brandon@jpl.nasa.gov NR 11 TC 23 Z9 25 U1 3 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JUN 30 PY 2007 VL 170 IS 1 BP 225 EP 232 DI 10.1016/j.jpowsour.2007.04.001 PG 8 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 186QP UT WOS:000247793500030 ER PT J AU Maus, S Sazonova, T Hemant, K Fairhead, JD Ravat, D AF Maus, S. Sazonova, T. Hemant, K. Fairhead, J. D. Ravat, Dhananjay TI National Geophysical Data Center candidate for the World Digital Magnetic Anomaly Map SO GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS LA English DT Article DE geomagnetic field; crustal field; satellite geomagnetism; aeromagnetic survey; marine magnetic data; geomagnetism and paleomagnetism : spatial variations : all harmonics and anomalies; geomagnetism and paleomagnetism : satellite magnetics : main field, crustal field, external field; geomagnetism and paleomagnetism : reference fields : regional, global ID LITHOSPHERIC FIELD; GLOBAL VECTOR AB [1] Marine and airborne magnetic anomaly data have been collected for more than half a century, providing global coverage of the Earth. Furthermore, the German CHAMP satellite is providing increasingly accurate information on large-scale magnetic anomalies. The World Digital Magnetic Anomaly Map project is an international effort to integrate all available near-surface and satellite magnetic anomaly data into a global map database. Teams of researchers were invited to produce candidate maps using a common pool of data sets. Here we present the National Geophysical Data Center (NGDC) candidate. To produce a homogeneous map, the near-surface data were first line-leveled and then merged by Least Squares Collocation. Long wavelengths were found to agree surprisingly well with independent satellite information. This validates our final processing step of merging the short-wavelength part of the near-surface data with long-wavelength satellite magnetic anomalies. C1 Univ Colorado, CIRES, Boulder, CO 80305 USA. NOAA, Natl Geophys Data Ctr, Boulder, CO 80305 USA. Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. Univ Leeds, GETECH, Leeds LS2 9JT, W Yorkshire, England. So Illinois Univ, Dept Geol, Carbondale, IL 62901 USA. RP Maus, S (reprint author), Univ Colorado, CIRES, 325 Broadway, Boulder, CO 80305 USA. EM stefan.maus@noaa.gov OI Ravat, Dhananjay/0000-0003-1962-4422 NR 22 TC 73 Z9 78 U1 2 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1525-2027 J9 GEOCHEM GEOPHY GEOSY JI Geochem. Geophys. Geosyst. PD JUN 29 PY 2007 VL 8 AR Q06017 DI 10.1029/2007GC001643 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 184ZA UT WOS:000247679900002 ER PT J AU Saiz-Lopez, A Chance, K Liu, X Kurosu, TP Sander, SP AF Saiz-Lopez, Alfonso Chance, Kelly Liu, Xiong Kurosu, Thomas P. Sander, Stanley P. TI First observations of iodine oxide from space SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MARINE BOUNDARY-LAYER; STRATOSPHERIC OZONE; MOLECULAR-IODINE; IO; CHEMISTRY; EMISSIONS; SPECTRA; MODEL; PHOTOCHEMISTRY; SCIAMACHY AB We present retrievals of IO total columns from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) satellite instrument. We analyze data for October 2005 in the polar regions to demonstrate for the first time the capability to measure IO column abundances from space. During the period of analysis (i.e. Southern Hemisphere springtime), enhanced IO vertical columns over 3 x 10(13) molecules cm(-2) are observed around coastal Antarctica; by contrast during that time in the Artic region IO is consistently below the calculated instrumental detection limit for individual radiance spectra ( 2 - 4 x 10(12) molecules cm(-2) for slant columns). The levels reported here are in reasonably good agreement with previous ground-based measurements at coastal Antarctica. These results also demonstrate that IO is widespread over sea-ice covered areas in the Southern Ocean. The occurrence of elevated IO and its hitherto unrecognized spatial distribution suggest an efficient iodine activation mechanism at a synoptic scale over coastal Antarctica. C1 CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. Harvard Smithsonian Ctr Astrophys, Atom & Mol Phys Div, Cambridge, MA 02138 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Saiz-Lopez, A (reprint author), CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. EM alfonso.saiz-lopez@jpl.nasa.gov RI Saiz-Lopez, Alfonso/B-3759-2015; Liu, Xiong/P-7186-2014; OI Saiz-Lopez, Alfonso/0000-0002-0060-1581; Liu, Xiong/0000-0003-2939-574X; Chance, Kelly/0000-0002-7339-7577 NR 34 TC 48 Z9 48 U1 1 U2 9 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 29 PY 2007 VL 34 IS 12 AR L12812 DI 10.1029/2007GL030111 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 184ZT UT WOS:000247681800005 ER PT J AU Osherovich, VA Benson, RF Fainberg, J Green, JL Garcia, L Boardsen, S Tsyganenko, N Reinisch, BW AF Osherovich, Vladimir A. Benson, Robert F. Fainberg, Joseph Green, James L. Garcia, Leonard Boardsen, Scott Tsyganenko, Nikolai Reinisch, Bodo W. TI Enhanced high-altitude polar cap plasma and magnetic field values in response to the interplanetary magnetic cloud that caused the great storm of 31 March 2001: A case study for a new magnetospheric index SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WIND QUASI-INVARIANT; SOLAR-WIND; GEOMAGNETIC-ACTIVITY; WAVE OBSERVATIONS; RESONANCES; RADIO; IONOSPHERE; IMAGE; CYCLE; MAGNETOPAUSE AB The magnetospheric electron number density and the magnetic field strength near 8 RE over the polar cap increased dramatically after the arrival of an interplanetary magnetic cloud on 31 March 2001. These parameters were determined with high accuracy from the plasma resonances stimulated by the Radio Plasma Imager (RPI) on Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) near apogee during both quiet (30 March 2001) and disturbed (31 March 2001) days. The quiet day and disturbed day values were each compared with magnetospheric magnetic field and electron density models; good agreement was found with the former but not the latter. The magnetospheric response was also expressed in terms of the ratio of the electron plasma frequency f(pe) to the electron cyclotron frequency f(ce), which is proportional to the ratio of the electron gyroradius to the Debye radius. Simultaneous Wind measurements of the solar wind magnetic field strength, speed, and plasma density were used to calculate the solar wind quasi-invariant QI. This index is equivalent to the ratio of the solar wind magnetic pressure to the solar wind ram pressure or to the inverse of the magnetic Mach number squared. These nondimensional quantities, QI and f(pe)/f(ce), have fundamental meanings in the solar wind MHD regime and in the relation between electric and magnetic forces on electrons in the magnetosphere, respectively. During the large 31 March 2001 storm, IMAGE was at the right place at the right time so as to enable comparisons between RPI f(pe)/f(ce) and Wind QI determinations. Both QI and f(pe)/f(ce) formed maxima during 6-hour observing intervals during this storm that were found to be highly correlated (87%) with a magnetospheric time lag of about 3 hours for f(pe)/f(ce). These results, based on a detailed case study of this important event, suggest that the plasma parameter f(pe)/f(ce) may serve as a useful magnetospheric index. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Washington, DC 20064 USA. NASA Headquarters, Washington, DC 20546 USA. Perot Syst, Plano, TX USA. Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA. Univ Space Res Assoc, Columbia, MD USA. Univ Massachusetts, Lowell, MA USA. RP Osherovich, VA (reprint author), NASA, Goddard Space Flight Ctr, Code 695, Greenbelt, MD 20771 USA. EM vladimir.a.osherovich.1@gsfc.nasa.gov; robert.f.benson@nasa.gov; joseph.fainberg@nasa.gov; james.green@nasa.gov; leonard.n.garcia.1@gsfc.nasa.gov; scott.a.boardsen.1@gsfc.nasa.gov; nikolai.tsyganenko@gsfc.nasa.gov; bodo_reinisch@uml.edu RI Tsyganenko, Nikolai/J-7377-2012 OI Tsyganenko, Nikolai/0000-0002-5938-1579 NR 44 TC 8 Z9 8 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUN 29 PY 2007 VL 112 IS A6 AR A06247 DI 10.1029/2006JA012105 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 185EL UT WOS:000247694100001 ER PT J AU Parks, GK Lee, E Lin, N Mozer, F Wilber, M Dandouras, I Reme, H Lucek, E Fazakerley, A Goldstein, M Gurgiolo, C Canu, P Cornilleau-Wehrlin, N Decreau, P AF Parks, G. K. Lee, E. Lin, N. Mozer, F. Wilber, M. Dandouras, I. Reme, H. Lucek, E. Fazakerley, A. Goldstein, M. Gurgiolo, C. Canu, P. Cornilleau-Wehrlin, N. Decreau, P. TI Solitary electromagnetic pulses detected with super-Alfvenic flows in Earth's geomagnetic tail SO PHYSICAL REVIEW LETTERS LA English DT Article ID PLASMA SHEET; CLUSTER; WAVES; ELECTRON; FIELD AB Solitary nonlinear (delta B/B >> 1) electromagnetic pulses have been detected in Earth's geomagnetic tail accompanying plasmas flowing at super-Alfvenic speeds. The pulses in the current sheet had durations of similar to 5 s, were left-hand circularly polarized, and had phase speeds of approximately the Alfven speed in the plasma frame. These pulses were associated with a field-aligned current J(parallel to) and observed in low density (similar to 0.3 cm(-3)), high temperature (T(e)similar to T(i)similar to 3x10(7) K), and beta similar to 10 plasma that included electron and ion beams streaming along B. The wave activity was enhanced from below the ion cyclotron frequency to electron cyclotron and upper hybrid frequencies. The detailed properties suggest the pulses are nonlinearly steepened ion cyclotron or Alfven waves. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Toulouse 3, Ctr Etud Spatiale Rayonnement, F-31062 Toulouse, France. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London, England. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Bitterroot Basic Res Inc, Hamilton, MT USA. CETP, Velizy Villacoublay, France. LPCE, Orleans, France. Univ Orleans, Orleans, France. RP Parks, GK (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM parks@ssl.berkeley.edu RI Lee, Ensang/E-2356-2013; OI Dandouras, Iannis/0000-0002-7121-1118 NR 25 TC 12 Z9 12 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 29 PY 2007 VL 98 IS 26 AR 265001 DI 10.1103/PhysRevLett.98.265001 PG 4 WC Physics, Multidisciplinary SC Physics GA 184EY UT WOS:000247625100026 PM 17678094 ER PT J AU Gintert, MJ Jana, SC Miller, SG AF Gintert, Michael J. Jana, Sadhan C. Miller, Sandi G. TI A novel strategy for nanoclay exfoliation in thermoset polyimide nanocomposite systems SO POLYMER LA English DT Article DE polymer composite materials; nanocomposites; polyimide ID MECHANICAL-PROPERTIES; SILICATE NANOCOMPOSITES; EPOXY NANOCOMPOSITES; CLAY NANOCOMPOSITES; ORGANOCLAY; COMPOSITES; CHARGE AB A novel method of nanoclay exfoliation in the synthesis of nanocomposites of PMR type thermoset resins was investigated. The method involves nanoclay intercalation by lower molecular weight PMR monomer prior to dispersion in primary, higher molecular weight PMR resin and resin curing to obtain the final composites. The resultant mechanical and thermal properties were evaluated as functions of clay type, degree of clay exfoliation, and clay intercalation strategies. It was found that sonication of clay at the time of intercalation by lower molecular weight PMR resin helps to achieve higher degree of exfoliation. In addition, clays obtained from ion exchange with a 50:50 mixture of N-[4(4-amino-benzyl)phenyl]-5-norborene-2,3-dicarboximide (APND), and dodecylamine (C12) showed better exfoliation than Cloisite (R) 30B clay. The resultant nanocomposites show higher thermal stability and higher tensile modulus. (c) 2007 Elsevier Ltd. All rights reserved. C1 Univ Akron, Dept Polymer Engn, Akron, OH 44325 USA. NASA, Glenn Res Ctr, Polymers Branch, Cleveland, OH 44135 USA. RP Jana, SC (reprint author), Univ Akron, Dept Polymer Engn, Akron, OH 44325 USA. EM janas@uakron.edu OI Jana, Sadhan/0000-0001-8962-380X NR 41 TC 33 Z9 35 U1 0 U2 4 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 29 PY 2007 VL 48 IS 14 BP 4166 EP 4173 DI 10.1016/j.polymer.2007.05.053 PG 8 WC Polymer Science SC Polymer Science GA 187NQ UT WOS:000247855300032 ER PT J AU Giglio, L AF Giglio, Louis TI Characterization of the tropical diurnal fire cycle using VIRS and MODIS observations SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE fire; biomass burning; diurnal cycle; MODIS; VIRS ID ATMOSPHERIC EMISSIONS; SAVANNA FIRES; SOUTH-AMERICA; BIOMASS; RESOLUTION; IDENTIFICATION; PRECIPITATION; VARIABILITY; ALGORITHMS; CLOUDINESS AB Seven years of data from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) were used to characterize the average diurnal fire cycle in 15 regions of the tropics and sub-tropics. Bias errors in the resulting diurnal cycles were either avoided or removed through a combination of judicious region selection and the application of corrections to compensate for cloud obscuration and time-dependent "blind spots" in the fire-detection capability of the VIRS sensor. Supplementary data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA's Terra satellite aided this process. In all regions, the local time of peak burning fell between 13:00 and 18:30, with fire activity peaking distinctly earlier for the heavily forested regions. The time period of the central 50% of total daily fire activity varied from a minimum of 1.3 h in North Central Africa to a maximum of 5.5 h in Eastern Australia. In general, shorter periods of burning were associated with greater tree cover. Using the diurnal cycles obtained for each region, an analysis of the drift in the local overpass times of the NOAA-7 through NOAA-14 afternoon satellites was performed. Results show that very large, spurious trends are likely to occur in a long-term Advanced Very High Resolution Radiometer (AVHRR) fire record due to differences in diurnal sampling over time. (c) 2006 Elsevier Inc. All rights reserved. C1 Sci Syst & Applicat Inc, Lanham, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Giglio, L (reprint author), Sci Syst & Applicat Inc, Lanham, MD USA. EM louis_giglio@ssaihq.com NR 45 TC 113 Z9 115 U1 3 U2 15 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 EI 1879-0704 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JUN 29 PY 2007 VL 108 IS 4 BP 407 EP 421 DI 10.1016/j.rse.2006.11.018 PG 15 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 177BE UT WOS:000247127800006 ER PT J AU Christoffersen, P Tulaczyk, S Behar, A Carsey, F AF Christoffersen, Poul Tulaczyk, Slawek Behar, Alberto Carsey, Frank TI Reply to comment by A. W. Rempel et al. on "A quantitative framework for interpretation of basal ice facies formed by ice accretion over subglacial sediment" SO JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE LA English DT Editorial Material ID FROST HEAVE; STREAM; MODEL; CONSTRAINTS; BENEATH; SYSTEM C1 Univ Cambridge, Scott Polar Res Inst, Cambridge CB2 1ER, England. Univ Calif Santa Cruz, Dept Earth & Planetary Sci, Santa Cruz, CA 95064 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Christoffersen, P (reprint author), Univ Cambridge, Scott Polar Res Inst, Cambridge CB2 1ER, England. EM pc350@cam.ac.uk RI Christoffersen, Poul/C-7328-2013 OI Christoffersen, Poul/0000-0003-2643-8724 NR 22 TC 3 Z9 3 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-EARTH JI J. Geophys. Res.-Earth Surf. PD JUN 28 PY 2007 VL 112 IS F2 AR F02037 DI 10.1029/2006JF000732 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 185BU UT WOS:000247687100005 ER PT J AU Ziurys, LM Milam, SN Apponi, AJ Woolf, NJ AF Ziurys, L. M. Milam, S. N. Apponi, A. J. Woolf, N. J. TI Chemical complexity in the winds of the oxygen-rich supergiant star VY Canis Majoris SO NATURE LA English DT Article ID GIANT BRANCH STARS; CIRCUMSTELLAR ENVELOPES; MASS-LOSS; BEARING MOLECULES; RED GIANTS; CHEMISTRY; ABUNDANCES; EMISSION; HCN; CONVECTION AB The interstellar medium is enriched primarily by matter ejected from old, evolved stars(1,2). The outflows from these stars create spherical envelopes, which foster gas-phase chemistry(3-5). The chemical complexity in circumstellar shells was originally thought to be dominated by the elemental carbon to oxygen ratio(6). Observations have suggested that envelopes with more carbon than oxygen have a significantly greater abundance of molecules than their oxygen-rich analogues(7). Here we report observations of molecules in the oxygen-rich shell of the red supergiant star VY Canis Majoris (VY CMa). A variety of unexpected chemical compounds have been identified, including NaCl, PN, HNC and HCO+. From the spectral line profiles, the molecules can be distinguished as arising from three distinct kinematic regions: a spherical outflow, a tightly collimated, blue-shifted expansion, and a directed, red-shifted flow. Certain species (SiO, PN and NaCl) exclusively trace the spherical flow, whereas HNC and sulphur-bearing molecules (amongst others) are selectively created in the two expansions, perhaps arising from shock waves. CO, HCN, CS and HCO+ exist in all three components. Despite the oxygen-rich environment, HCN seems to be as abundant as CO. These results suggest that oxygen-rich shells may be as chemically diverse as their carbon counterparts. C1 Univ Arizona, Astrobiol Inst, NASA, Tucson, AZ 85721 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Univ Arizona, Arizona Radio Observ, Tucson, AZ 85721 USA. Univ Arizona, Dept Astron, Steward Observ, Tucson, AZ 85721 USA. RP Ziurys, LM (reprint author), Univ Arizona, Astrobiol Inst, NASA, 1306 E Univ Blvd, Tucson, AZ 85721 USA. EM lziurys@as.arizona.edu RI Milam, Stefanie/D-1092-2012 OI Milam, Stefanie/0000-0001-7694-4129 NR 30 TC 63 Z9 64 U1 4 U2 16 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 28 PY 2007 VL 447 IS 7148 BP 1094 EP 1097 DI 10.1038/nature05905 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 183HT UT WOS:000247564600033 PM 17597755 ER PT J AU Illig, S Perigaud, C AF Illig, Serena Perigaud, Claire TI Yearly impact of submonthly rain fluctuations on the Indian Ocean salinity SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANOMALIES; DYNAMICS; MODELS; LAYER AB We investigate the impact of submonthly rain fluctuations on the daily-to-interannual variations of the salinity in the tropical Indian Ocean. A three-year record of daily observed precipitation and wind are used to force an Indian Ocean model in two experiments that differ only by their rain forcing, which is either daily-(Exp_day) or monthly- (Exp_month) averaged. Results show that submonthly precipitations significantly impact the Surface Layer Salinity (SLS) in the northern and eastern Bay of Bengal during the wet season from May to November. In September when the Bay reaches its SLS minimum, the Andaman Sea is saltier by as much as 1.3 psu for Exp_day. The frequency shift between the submonthly rain forcing and the yearly salinity response is due to accumulation in time of nonlinear mechanisms: sudden rain deficits increase the SLS by entraining salty waters from below, whereas rain excesses are inefficient to decrease the salinity of the thick surface layer. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Illig, S (reprint author), CALTECH, Jet Prop Lab, MS 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM sig@pacific.jpl.nasa.gov NR 10 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 JUN 27 PY 2007 VL 34 IS 12 AR L12609 DI 10.1029/2007GL029655 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 184ZN UT WOS:000247681200002 ER PT J AU Gamblin, B Toon, OB Tolbert, MA Kondo, Y Takegawa, N Irie, H Koike, M Hudson, PK Ballenthin, JO Hunton, DE Miller, TM Viggiano, AA Anderson, BE Avery, M Sachse, GW Guenther, K Sorenson, C Mahoney, MJ AF Gamblin, B. Toon, O. B. Tolbert, M. A. Kondo, Y. Takegawa, N. Irie, H. Koike, M. Hudson, P. K. Ballenthin, J. O. Hunton, D. E. Miller, T. M. Viggiano, A. A. Anderson, B. E. Avery, M. Sachse, G. W. Guenther, K. Sorenson, C. Mahoney, M. J. TI Nitric acid condensation on ice: 2. Kinetic limitations, a possible "cloud clock'' for determining cloud parcel lifetime SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID REACTIVE NITROGEN; SULFURIC-ACID; CIRRUS CLOUDS; WATER-ICE; HNO3; TEMPERATURES; PARTICLES; STRATOSPHERE; TROPOSPHERE AB [1] Measurements of NOY condensation on cirrus particles found in stratospherically influenced air sampled during the SOLVE-I mission are analyzed and compared with data from other field studies of HNO3 or NOY condensation on ice. Each field study exhibits an order of magnitude data spread for constant HNO3 pressures and temperatures. While others assumed this distribution is due to random error, the data spread exceeds instrument precision errors and instead suggests HNO3 removal had not attained equilibrium at the time of sampling. During the SOLVE-I mission, condensation on ice was a significant sink for HNO3 despite submonolayer surface coverages; we therefore propose condensation of HNO3 on lower-stratospheric cirrus particles is controlled by kinetics and will occur at a kinetically limited rate. Furthermore, we suggest the low accommodation coefficient for HNO3 on ice combined with relatively short-lived clouds causes highly scattered, limited HNO3 uptake on cirrus particles. We couple laboratory data on the accommodation coefficient of HNO3 on ice with field surface coverage data in order to generate a "cloud clock'': a calculation to determine the age of a cloud parcel. Data from the aforementioned field studies are compared to theoretical models for equilibrium surface coverage on the basis of laboratory data extrapolated to atmospheric temperatures and HNO3 pressures. This comparison is difficult because most of the atmospheric data are probably not at equilibrium and follow a condensation time curve rather than an equilibrium surface coverage curve. Finally, we develop a simple mathematical solution for the time required for HNO3 condensation on ice. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Japan Agcy Marine Earth Sci & Technol, Frontier Res Ctr Global Change, Kanasawa Ku, Kanagawa 2360001, Japan. Univ Tokyo, Dept Earth & Planetary Phys, Tokyo, Japan. Univ Iowa, Dept Chem, Iowa City, IA 52242 USA. USAF, Res Lab, Hanscom AFB, MA 01731 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. NASA, Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gamblin, B (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. EM bgamblin@airsci.com RI Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012 NR 25 TC 1 Z9 1 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 27 PY 2007 VL 112 IS D12 AR D12209 DI 10.1029/2005JD006049 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 185AG UT WOS:000247683100001 ER PT J AU Pierce, RB Schaack, T Al-Saadi, JA Fairlie, TD Kittaka, C Lingenfelser, G Natarajan, M Olson, J Soja, A Zapotocny, T Lenzen, A Stobie, J Johnson, D Avery, MA Sachse, GW Thompson, A Cohen, R Dibb, JE Crawford, J Rault, D Martin, R Szykman, J Fishman, J AF Pierce, Robert B. Schaack, Todd Al-Saadi, Jassim A. Fairlie, T. Duncan Kittaka, Chieko Lingenfelser, Gretchen Natarajan, Murali Olson, Jennifer Soja, Amber Zapotocny, Tom Lenzen, Allen Stobie, James Johnson, Donald Avery, Melody A. Sachse, Glen W. Thompson, Anne Cohen, Ron Dibb, Jack E. Crawford, Jim Rault, Didier Martin, Randall Szykman, Jim Fishman, Jack TI Chemical data assimilation estimates of continental US ozone and nitrogen budgets during the Intercontinental Chemical Transport Experiment-North America SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INERT TRACE CONSTITUENT; FOSSIL-FUEL COMBUSTION; THETA-SIGMA MODEL; UNITED-STATES; SATELLITE MEASUREMENTS; JOINT DISTRIBUTIONS; GLOBAL ATMOSPHERE; REACTIVE NITROGEN; RATE COEFFICIENT; BOUNDARY-LAYER AB [1] Global ozone analyses, based on assimilation of stratospheric profile and ozone column measurements, and NOy predictions from the Real-time Air Quality Modeling System (RAQMS) are used to estimate the ozone and NOy budget over the continental United States during the July - August 2004 Intercontinental Chemical Transport Experiment - North America (INTEX-A). Comparison with aircraft, satellite, surface, and ozonesonde measurements collected during INTEX-A show that RAQMS captures the main features of the global and continental U. S. distribution of tropospheric ozone, carbon monoxide, and NOy with reasonable fidelity. Assimilation of stratospheric profile and column ozone measurements is shown to have a positive impact on the RAQMS upper tropospheric/lower stratosphere ozone analyses, particularly during the period when SAGE III limb scattering measurements were available. Eulerian ozone and NOy budgets during INTEX-A show that the majority of the continental U. S. export occurs in the upper troposphere/ lower stratosphere poleward of the tropopause break, a consequence of convergence of tropospheric and stratospheric air in this region. Continental U. S. photochemically produced ozone was found to be a minor component of the total ozone export, which was dominated by stratospheric ozone during INTEX-A. The unusually low photochemical ozone export is attributed to anomalously cold surface temperatures during the latter half of the INTEX-A mission, which resulted in net ozone loss during the first 2 weeks of August. Eulerian NOy budgets are shown to be very consistent with previously published estimates. The NOy export efficiency was estimated to be 24%, with NOx + PAN accounting for 54% of the total NOy export during INTEX-A. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Wisconsin, Ctr Space Sci & Engn, Madison, WI 53706 USA. Sci Applicat Int Corp, Washington, DC 20591 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ New Hampshire, Dept Earth Sci, Durham, NH 03824 USA. Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS B3H 4R2, Canada. US EPA, Raleigh, NC USA. RP Pierce, RB (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM r.b.pierce@larc.nasa.gov; todds@ssec.wisc.edu; j.a.al-saadi@nasa.gov; t.d.fairlie@larc.nasa.gov; fn.c.kittaka@larc.nasa.gov; g.s.lingenfelser@larc.nasa.gov; m.natarajan@larc.nasa.gov; j.r.olson@larc.nasa.gov; a.j.soja@larc.nasa.gov; tomz@ssec.wisc.edu; allenl@ssec.wisc.edu; james.stobie@auatac.com; donj@ssec.wisc.edu; m.a.avery@larc.nasa.gov; g.w.sachse@larc.nasa.gov; anne@met.psu.edu; cohen@cchem.berkeley.edu; jack.dibb@unh.edu; j.h.crawford@larc.nasa.gov; d.f.rault@larc.nasa.gov; randall.martin@dal.ca; j.j.szykman@larc.nasa.gov; j.fishman@larc.nasa.gov RI Martin, Randall/A-2051-2008; Cohen, Ronald/A-8842-2011; Pierce, Robert Bradley/F-5609-2010; Crawford, James/L-6632-2013; Thompson, Anne /C-3649-2014 OI Cohen, Ronald/0000-0001-6617-7691; Pierce, Robert Bradley/0000-0002-2767-1643; Crawford, James/0000-0002-6982-0934; Thompson, Anne /0000-0002-7829-0920 NR 76 TC 70 Z9 71 U1 1 U2 14 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 27 PY 2007 VL 112 IS D12 AR D12S21 DI 10.1029/2006JD007722 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 185AG UT WOS:000247683100003 ER PT J AU Spackman, JR Weinstock, EM Anderson, JG Hurst, DF Jost, HJ Schauffler, SM AF Spackman, J. R. Weinstock, E. M. Anderson, J. G. Hurst, D. F. Jost, H.-J. Schauffler, S. M. TI Aircraft observations of rapid meridional transport from the tropical tropopause layer into the lowermost stratosphere: Implications for midlatitude ozone SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID IN-SITU MEASUREMENTS; TOTAL HYDROGEN BUDGET; ROSSBY-WAVE BREAKING; NASA ER-2 AIRCRAFT; WATER-VAPOR; UPPER TROPOSPHERE; SEASONAL CYCLE; POLAR VORTEX; NITROUS-OXIDE; TRACE GASES AB [1] Meridional transport from the tropics redistributes ozone and water vapor at middle and high latitudes. In situ measurements of water vapor, CH4, and N2O, acquired aboard the NASA ER-2 aircraft during January - March 2000 in a campaign to survey the Arctic vortex, are used to examine transport into the lowermost stratosphere in the context of middle- and high-latitude ozone declines observed over the last several decades. Analysis of tracer-tracer correlations of H2O + 2* CH4 and N2O indicates that rapid, poleward isentropic transport from the lower tropical stratosphere coupled with diabatic descent between the subtropical and polar jet streams delivers very young air to the high-latitude lowermost stratosphere during winter, while descent of older air from the vortex and subsequent transport to lower latitudes is very limited. From middle to late winter, mixing ratios of H2O + 2* CH4 decrease by about 1 ppmv immediately outside the vortex, consistent with rapid transport of the winter phase of the seasonal cycle in water vapor to high latitudes from the lower tropical stratosphere. No evidence of isentropic mixing from the upper tropical troposphere survives in the high-latitude lowermost stratosphere except below 350 K, where markedly higher water vapor mixing ratios indicate mixing from the extratropical troposphere. All of these transport processes pose dynamical and chemical consequences for ozone. Transport from the lower tropical stratosphere ( 1) exports ozone-poor air to midlatitudes and the subvortex region and ( 2) distributes elevated water vapor to high latitudes, potentially enhancing halogen-catalyzed ozone destruction through heterogeneous processing in the polar vortex. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Earth Syst Res Lab, Global Monitoring Div, Boulder, CO 80305 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. RP Spackman, JR (reprint author), NOAA, Earth Syst Res Lab, Div Chem Sci, 325 Broadway R-CSD6, Boulder, CO 80305 USA. EM ryan.spackman@noaa.gov RI Hurst, Dale/D-1554-2016 OI Hurst, Dale/0000-0002-6315-2322 NR 92 TC 7 Z9 8 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 27 PY 2007 VL 112 IS D12 AR D12308 DI 10.1029/2006JD007618 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 185AG UT WOS:000247683100002 ER PT J AU Hakkinen, S Dupont, F Karcher, M Kauker, F Worthen, D Zhang, J AF Haekkinen, S. Dupont, F. Karcher, M. Kauker, F. Worthen, D. Zhang, J. TI Model simulation of Greenland Sea upper-ocean variability SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORTHERN NORTH-ATLANTIC; ARCTIC-OCEAN; NORDIC SEAS; CIRCULATION; SALINITY; ICE; EVENTS AB [1] Observations indicate that the occurrence of dense upper-ocean water masses coincides with periods of intense deep-water formation in the Greenland Sea. This paper focuses on the upper-ocean hydrography of the area and its simulation in models. We analyze properties that reside below the summer mixed layer at 200 m and carry the winter mixing signal. The analysis employs numerical simulations from four different models, all of which are forced as specified by the Arctic Ocean Model Intercomparison Project (AOMIP). The models exhibit varying degrees of success in simulating upper-ocean properties observed in the Greenland Sea, including very dense, saline water masses in the 1950s, 1960s, and 1970s. Two of the models predict the importance of salinity in determining the maximum density in the upper waters of the central gyre. The circulation pattern of Atlantic Water was captured well by two high-resolution models as measured by temperature-salinity-density relationships. The simulated temporal variability of Atlantic Water properties was less satisfactory, particularly in the case of salinity. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Laval, Quebec Ocean, Ste Foy, PQ G1K 7P4, Canada. OASys Ocean Atmosphere Syst GbR, Hamburg, Germany. Alfred Wegener Inst Polar & Marine Res, D-27515 Bremerhaven, Germany. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA. RP Hakkinen, S (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM sirpa.hakkinen@nasa.gov RI Hakkinen, Sirpa/E-1461-2012 NR 35 TC 7 Z9 7 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 27 PY 2007 VL 112 IS C6 AR C06S90 DI 10.1029/2006JC003687 PG 14 WC Oceanography SC Oceanography GA 185CO UT WOS:000247689100001 ER PT J AU Tripathi, OP Godin-Beekmann, S Lefevre, F Pazmino, A Hauchecorne, A Chipperfield, M Feng, W Millard, G Rex, M Streibel, M von der Gathen, P AF Tripathi, Om Prakash Godin-Beekmann, Sophie Lefevre, Franck Pazmino, Andrea Hauchecorne, Alain Chipperfield, Martyn Feng, Wuhu Millard, Genevieve Rex, Markus Streibel, Martin von der Gathen, Peter TI Comparison of polar ozone loss rates simulated by one-dimensional and three-dimensional models with Match observations in recent Antarctic and Arctic winters SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHEMICAL-TRANSPORT MODEL; IN-SITU MEASUREMENTS; LOWER STRATOSPHERE; LIDAR MEASUREMENTS; ADVECTION MODEL; SELF-REACTION; VORTEX; DEPLETION; CLO; CHEMISTRY AB [1] Simulations of ozone loss rates using a three-dimensional chemical transport model and a box model during recent Antarctic and Arctic winters are compared with experimental loss rates. The study focused on the Antarctic winter 2003, during which the first Antarctic Match campaign was organized, and on Arctic winters 1999/2000, 2002/2003. The maximum ozone loss rates retrieved by the Match technique for the winters and levels studied reached 6 ppbv/sunlit hour and both types of simulations could generally reproduce the observations at 2-sigma error bar level. In some cases, for example, for the Arctic winter 2002/2003 at 475 K level, an excellent agreement within 1-sigma standard deviation level was obtained. An overestimation was also found with the box model simulation at some isentropic levels for the Antarctic winter and the Arctic winter 1999/2000, indicating an overestimation of chlorine activation in the model. Loss rates in the Antarctic show signs of saturation in September, which have to be considered in the comparison. Sensitivity tests were performed with the box model in order to assess the impact of kinetic parameters of the ClO-Cl(2)O(2) catalytic cycle and total bromine content on the ozone loss rate. These tests resulted in a maximum change in ozone loss rates of 1.2 ppbv/sunlit hour, generally in high solar zenith angle conditions. In some cases, a better agreement was achieved with fastest photolysis of Cl(2)O(2) and additional source of total inorganic bromine but at the expense of overestimation of smaller ozone loss rates derived later in the winter. C1 Univ Paris 06, CNRS, IPSL, Serv Aeron, F-75252 Paris, France. Univ Leeds, Inst Atmospher Sci, Leeds LS2 9JT, W Yorkshire, England. Univ Cambridge, Dept Earth Sci, Cambridge CB2 3EQ, England. Alfred Wegener Inst Polar & Marine Res, D-14473 Potsdam, Germany. RP Tripathi, OP (reprint author), CALTECH, NASA, Jet Prop Lab, Table Mt Facil, 24490 Table Mt Rd, Wrightword, CA 92397 USA. EM ompraka@aero.jussieu.fr RI FENG, WUHU/B-8327-2008; Rex, Markus/A-6054-2009; von der Gathen, Peter/B-8515-2009; Hauchecorne, Alain/A-8489-2013; Chipperfield, Martyn/H-6359-2013; OI FENG, WUHU/0000-0002-9907-9120; Rex, Markus/0000-0001-7847-8221; von der Gathen, Peter/0000-0001-7409-1556; Chipperfield, Martyn/0000-0002-6803-4149; Hauchecorne, Alain/0000-0001-9888-6994 NR 67 TC 17 Z9 17 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-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 26 PY 2007 VL 112 IS D12 AR D12307 DI 10.1029/2006JD008370 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 185AD UT WOS:000247682800001 ER PT J AU Bansal, NP Zhu, DM AF Bansal, Narottam P. Zhu, Dongming TI Effects of doping on thermal conductivity of pyrochlore oxides for advanced thermal barrier coatings SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE pyrochlore oxides; thermal conductivity; thermal barrier coatings; doping ID LANTHANUM; SYSTEM; TBCS AB Pyrochlore oxides of general composition, A(2)B(2)O(7), where A is a 3+ cation (La to Lu) and B is a 4+ cation (Zr, Hf, Ti, etc.) have high melting point, relatively high coefficient of thermal expansion, and low thermal conductivity which make them suitable for applications as high-temperature thermal barrier coatings. The effect of doping at the A site on the thermal conductivity of a pyrochlore oxide La2Zr2O7, has been investigated. Oxide powders of various compositions La2Zr2O7, La1.7Gd0.3Zr2O7, La1.7Yb0.3Zr2O7 and La1.7Gd0.15Yb0.15Zr2O7 were synthesized by the citric acid sol-gel method. These powders were hot-pressed into discs and used for thermal conductivity measurements using a steady-state laser heat flux test technique. The rare-earth oxide doped pyrochlores La1.7Gd0.3Zr2O7, La1.7Yb0.3Zr2O7 and La1.7Gd0.15Yb0.15Zr,07 had lower thermal conductivity than the undoped La2Zr2O7. The Gd2O3 and Yb-0.3 co-doped composition showed the lowest thermal conductivity. (C) 2007 Elsevier B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Mat & Struct Div, Cleveland, OH 44135 USA. USA, Res Lab, NASA, Glenn Res Ctr,Vehicle Technol Directorate, Cleveland, OH 44135 USA. RP Bansal, NP (reprint author), NASA, Glenn Res Ctr, Mat & Struct Div, Cleveland, OH 44135 USA. EM Narottam.P.Bansal@nasa.gov NR 12 TC 55 Z9 65 U1 6 U2 63 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 25 PY 2007 VL 459 IS 1-2 BP 192 EP 195 DI 10.1016/j.msea.2007.01.069 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 171IL UT WOS:000246729300026 ER PT J AU Arimoto, M Kawai, N Suzuki, M Sato, R Pazmino, NV Shimokawabe, T Ishimura, T Kotoku, J Yoshida, A Tamagawa, T Shirasaki, Y Matsuoka, M Nakagawa, Y Ishikawa, N Kobayashi, A Sugita, S Takahashi, I Kuwahara, M Yamauchi, M Takagishi, K Hatsukade, I Atteia, JL Pelangeon, A Vanderspek, R Graziani, C Prigozhin, G Villasenor, J Jernigan, JG Crew, GB Hurley, K Sakamoto, T Ricker, GR Woosley, SE Butler, N Levine, A Doty, JP Donaghy, TQ Lamb, DQ Fenimore, EE Galassi, M Boer, M Dezalay, JP Olive, JF Braga, J Manchanda, R Pizzichini, G AF Arimoto, Makoto Kawai, Nobuyuki Suzuki, Motoko Sato, Rie Pazmino, Nicolas Vasquez Shimokawabe, Takashi Ishimura, Takuto Kotoku, Jun'ichi Yoshida, Atsumasa Tamagawa, Toru Shirasaki, Yuji Matsuoka, Masaru Nakagawa, Yujin Ishikawa, Nobuyuki Kobayashi, Akina Sugita, Satoshi Takahashi, Ichiro Kuwahara, Makoto Yamauchi, Makoto Takagishi, Kunio Hatsukade, Isamu Atteia, Jean-Luc Pelangeon, Alexandre Vanderspek, Roland Graziani, Carlo Prigozhin, Gregory Villasenor, Joel Jernigan, J. Garrett Crew, Geoffrey B. Hurley, Kevin Sakamoto, Takanori Ricker, George R. Woosley, Stanford E. Butler, Nat Levine, Al Doty, John P. Donaghy, Timothy Q. Lamb, Donald Q. Fenimore, Edward E. Galassi, Mark Boer, Michel Dezalay, Jean-Pascal Olive, Jean-Francois Braga, Joao Manchanda, Ravi Pizzichini, Graziella TI HETE-2 observations of the X-ray flash XRF 040916 SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE gamma-rays : bursts; X-rays : bursts; X-rays : individual (XRF 040916) ID BURST AFTERGLOWS; REFRESHED SHOCKS; JET; VARIABILITY; PERFORMANCE; GRB-011211; INJECTION; SPECTRA; FLARES; MODEL AB A long X-ray flash was detected and localized by instruments aboard the High Energy Transient Explorer II (HETE-2) at 00:03:30 UT on 2004 September 16. The position was reported to the GRB Coordinates Network (GCN) approximately 2 hours after the burst. This burst consisted of two peaks separated by similar to 200 s, with durations of about 110 s and 60 s. We analyzed the energy spectra of the 1st and 2nd peaks observed with the Wide Field X-Ray Monitor (WXM) and the French Gamma Telescope (FREGATE). We discuss the origin of the 2nd peak in terms of the flux variabilities and timescales. We find that it is most likely to be part of prompt emission, and is explained by a long-acting engine model. This feature is similar to some bright X-ray flares detected in the early afterglow phase of bursts observed by the Swift satellite. C1 Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. Aoyama Gakuin Univ, Dept Phys & Math, Sagamihara, Kanagawa 2298558, Japan. RIKEN, Wako, Saitama 3510198, Japan. Natl Astron Observ, Mitaka, Tokyo 1818588, Japan. JAXA, Tsuchiura, Ibaraki 3058505, Japan. Miyazaki Univ, Fac Engn, Miyazaki 8892192, Japan. Observ Midi Pyrenees, CNRS, LATT, UPS, F-31400 Toulouse, France. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Noqsi Aerospace Ltd, Pine, CO 80470 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Observ Midi Pyrenees, Ctr Etude Spatiale Rayonnements, F-31028 Toulouse, France. IASF Bologna, INAF, I-40129 Bologna, Italy. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Inst Nacl Pesquisas Espaciais, BR-12227 Sao Jose Dos Campos, Brazil. Tata Inst Fundamental Res, Dept Astron & Astrophys, Bombay 400005, Maharashtra, India. RP Arimoto, M (reprint author), Tokyo Inst Technol, Dept Phys, Meguro Ku, 2-21-1 Ookayama, Tokyo 1528551, Japan. EM arimoto@hp.phys.titech.ac.jp NR 32 TC 2 Z9 2 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD JUN 25 PY 2007 VL 59 IS 3 BP 695 EP 702 DI 10.1093/pasj/59.3.695 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 188ZV UT WOS:000247958900020 ER PT J AU Volkov, DL Larnicol, G Dorandeu, J AF Volkov, Denis L. Larnicol, Gilles Dorandeu, Joel TI Improving the quality of satellite altimetry data over continental shelves SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA-LEVEL; OCEAN CIRCULATION; MAPPING CAPABILITIES; TOPEX/POSEIDON; VARIABILITY; TIDES; MISSIONS; SIGNALS; MODEL AB Satellite altimetry has proven to be a useful tool to study oceanic processes in the deep ocean. Over continental shelves, however, the aliasing of unresolved high-frequency signals of tidal and wind-induced origin is the source of long-wavelength errors that corrupt altimetry measurements and limit their use in shallow waters. In 2005, SSALTO/DUACS performed a complete reanalysis of altimeter data to accommodate the latest tidal model (GOT2000) and a correction for the aliased high-frequency signals using a hydrodynamic model MOG2D-G. This paper examines the quality and the performance of the newly released altimetry data over the northwest European shelf. This region is known for complex tides and for frequent storm surges. The newly corrected maps of sea level anomalies were compared with a previous altimetry product. Residual tidal aliasing was analyzed, and the impact of MOG2D-G and GOT2000 models was assessed. Altimeter records were compared with tide gauge measurements. This research showed a significant reduction in the contamination of data by high-frequency aliasing achieved through the use of the aforementioned models. However, aliased shallow-water tidal constituents pose a serious problem, and it is obvious that future tidal corrections should feature local tides. Nonaliased, physical sea level variability was also studied focusing on interannual, seasonal, and intra-annual (periods from 20 days to 1 year) modes. The magnitudes and the contributions of each mode to the total variance were estimated. It was demonstrated that the newly corrected data can successfully be used to study the variability of sea level over continental shelves. C1 CLS, Space Oceanog Div, F-31520 Ramonville Saint Agne, France. RP Volkov, DL (reprint author), CALTECH, NASA, Jet Propuls Lab, Pasadena, CA 91125 USA. EM dvolkov@caltech.edu RI Volkov, Denis/A-6079-2011 OI Volkov, Denis/0000-0002-9290-0502 NR 32 TC 66 Z9 66 U1 0 U2 6 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 23 PY 2007 VL 112 IS C6 AR C06020 DI 10.1029/2006JC003765 PG 20 WC Oceanography SC Oceanography GA 182XG UT WOS:000247536700001 ER PT J AU Hulley, GC Pavlis, EC AF Hulley, G. C. Pavlis, E. C. TI A ray-tracing technique for improving Satellite Laser Ranging atmospheric delay corrections, including the effects of horizontal refractivity gradients SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID TRACKING DATA; AIR; TERRESTRIAL; INDEX AB In this paper we study the effects of horizontal refractivity gradients on the propagation of optical signals for a globally distributed set of Satellite Laser Ranging (SLR) stations. Using two-dimensional ray tracing and globally distributed satellite data from NASA's Atmospheric Infrared Sounder (AIRS), as well atmospheric fields from the National Center for Environmental Prediction (NCEP), we calculate the effects of horizontal gradients on a global set of SLR stations using 2 years of data during 2004 and 2005. We investigate in detail how seasonal and diurnal changes, latitudinal dependence, topography, and oceans affect the gradients at specific locations, as well as the application of these gradients on a set of SLR data from the LAGEOS 1 and 2 geodetic satellites. For the year 2004, AIRS ray-tracing results showed maximum north-south (NS) gradient delays of 50 mm at 10 degrees elevation angle at Herstmonceux, UK and east-west (EW) gradient delays of 35 mm at Yarragadee, Australia. Mean NS and EW gradients had delays not exceeding 5 mm for both AIRS and NCEP analysis at all stations. The standard deviations of AIRS gradients ranged from 6 to 12 mm, while NCEP gradients ranged from 3 to 9 mm, depending on location and time of year. The effects of applying AIRS and NCEP total ray-tracing results, including horizontal gradient contributions, to a set of global SLR geodetic data resulted in reduction of the solution residuals by up to 43% in variance percent difference. This is a highly significant contribution for the SLR technique's effort to reach an accuracy at the 1-mm level this decade. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Joint Ctr Earth Syst Technol, Greenbelt, MD 20771 USA. RP Hulley, GC (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, 1000 Hilltop Circle, Baltimore, MD 21228 USA. EM ghulley1@umbc.edu; epavlis@umbc.edu NR 23 TC 8 Z9 8 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 23 PY 2007 VL 112 IS B6 AR B06417 DI 10.1029/2006JB004834 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 182XX UT WOS:000247538400005 ER PT J AU Ciftcioglu, N Aho, KM Mckay, DS Kajander, EO AF Ciftcioglu, Neva Aho, Katja M. McKay, David S. Kajander, E. Olavi TI Are apatite nanoparticles safe? SO LANCET LA English DT Letter C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Kuopio, FIN-70211 Kuopio, Finland. Nanobac Pharmaceut, Tampa, FL USA. RP Ciftcioglu, N (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM neva.ciftcioglu-1@nasa.gov NR 5 TC 16 Z9 16 U1 2 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0140-6736 J9 LANCET JI Lancet PD JUN 23 PY 2007 VL 369 IS 9579 BP 2078 EP 2078 DI 10.1016/S0140-6736(07)60977-5 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA 182GM UT WOS:000247493100025 PM 17586302 ER PT J AU Halkides, DJ Han, WQ Lee, T Masumoto, Y AF Halkides, D. J. Han, Weiqing Lee, Tong Masumoto, Yukio TI Effects of sub-seasonal variability on seasonal-to-interannual Indian Ocean meridional heat transport SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC INTRASEASONAL VARIABILITY; MADDEN-JULIAN OSCILLATION; DYNAMICS; PACIFIC; RECTIFICATION; SURFACE; DIPOLE; IMPACT; CYCLE; MODEL AB Numerical experiments using the Hybrid Coordinate Ocean Model are performed to examine atmospheric intraseasonal oscillation (ISO) effects on seasonal-to-interannual meridional heat transport (Q(v)) in the tropical Indian Ocean. Analysis focuses on the equator and 14.5 degrees S, latitudes associated with the cross-equatorial and southern subtropical meridional cells. ISOs alter seasonal Q(v) anomaly (Q(v)*) at these latitudes by a-few-hundredths PW up to 2 - 3 tenths PW. On interannual timescales, heat transport anomaly (Q(v)') induced by ISOs tends to reinforce (correlates positively with) the total Q(v)' signal. ISO winds can induce interannual Q(v)' up to 0.15 PW, comparable to the maximum amplitude of the Q(v)' signal. Net effects of atmospheric ISOs can account for similar to 30% of Q(v)' in some years; in others, ISO contributions are insignificant. Wind stress ( via momentum flux) and wind speed ( via turbulent heat fluxes and vertical mixing) play notable roles in ISO effects on Q(v)* and in some years on Q(v)'. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. Japan Agcy Marine Earth Sci & Technol, Inst Observat Res Global Change, Yokosuka, Kanagawa 2370061, Japan. Univ Tokyo, Dept Earth & Planetary Sci, Tokyo, Japan. RP Halkides, DJ (reprint author), CALTECH, Jet Prop Lab, JPL Mail Stop 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM halkides@jpl.nasa.gov; whan@enso.colorado.edu RI MASUMOTO, YUKIO/G-5021-2014 NR 31 TC 9 Z9 9 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 22 PY 2007 VL 34 IS 12 AR L12605 DI 10.1029/2007GL030150 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 182VY UT WOS:000247533300006 ER PT J AU Gopalswamy, N Yashiro, S Akiyama, S AF Gopalswamy, N. Yashiro, S. Akiyama, S. TI Geoeffectiveness of halo coronal mass ejections SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ENERGETIC PARTICLE EVENTS; GEOMAGNETIC STORMS; MAGNETIC STORMS; SOLAR; SOLAR-CYCLE-23; PARAMETERS; REGIONS; CLOUDS; LASCO AB We studied the geoeffectiveness, speed, solar source, and flare association of a set of 378 halo coronal mass ejections (CMEs) of cycle 23 (1996-2005, inclusive). We compiled the minimum Dst values occurring within 1-5 days after the CME onset. We compared the distributions of such Dst values for the following subsets of halo CMEs: disk halos (within 45 deg from disk center), limb halos (beyond 45 degrees but within 90 deg from disk center), and backside halo CMEs. Defining that a halo CME is geoeffective if it is followed by Dst <= -50 nT, moderately geoeffective if -50 nT < Dst < -100 nT, and strongly geoeffective if Dst <= -100 nT, we find that the disk halos are followed by strong storms, limb halos are followed by moderate storms, and backside halos are not followed by significant storms. The Dst distribution for a random sample is nearly identical to the case of backside halos. About 71% of all frontside halos are geoeffective, supporting the high rate of geoeffectiveness of halo CMEs. A larger fraction (75%) of disk halos are geoeffective. Intense storms are generally due to disk halos and the few intense storms from limb halos occur only in the maximum and declining phases. Most intense storms occur when there are successive CMEs. The delay time between CME onset and minimum Dst value is the smallest for limb halos, suggesting that the sheath is geoeffective in these cases. The geoeffectiveness rate has prominent dips in 1999 and 2002 (the beginning and end years of the solar maximum phase). The numbers of all frontside and geoeffective frontside halos show a triple peak structure similar to the number of intense geomagnetic storms. The difference in flare sizes among geoeffective and nongeoeffective halos is not significant. The nongeoeffective CMEs are generally slower and have more easterly or limbward solar sources compared to the geoeffective ones; source location and speed are the most important parameters for geoeffectiveness. C1 NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. Catholic Univ Amer, Washington, DC 20064 USA. RP Gopalswamy, N (reprint author), NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Code 695, Greenbelt, MD 20771 USA. EM gopals@ssedmail.gsfc.nasa.gov RI Gopalswamy, Nat/D-3659-2012; OI Gopalswamy, Nat/0000-0001-5894-9954 NR 33 TC 87 Z9 90 U1 0 U2 3 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 22 PY 2007 VL 112 IS A6 AR A06112 DI 10.1029/2006JA012149 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182YC UT WOS:000247538900004 ER PT J AU Leitner, M Farrugia, CJ Mostl, C Ogilvie, KW Galvin, AB Schwenn, R Biernat, HK AF Leitner, M. Farrugia, C. J. Moestl, C. Ogilvie, K. W. Galvin, A. B. Schwenn, R. Biernat, H. K. TI Consequences of the force-free model of magnetic clouds for their heliospheric evolution SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTION; WIND QUASI-INVARIANT; SOLAR-WIND; 1 AU; DEPENDENCE; MAGNETOSPHERE; PARAMETERS; SPHEROMAK; PASSAGE; EVENTS AB We examine the implications of the widely used, force-free, constant-alpha flux rope model of interplanetary magnetic clouds for the evolution of these mesoscale (fraction 1 AU) structures in the heliosphere, with special emphasis on the inner (<= 1 AU) heliosphere. We employ primarily events observed by the Helios 1 and 2 probes between 0.3 and 1 AU in the ascending and maximum phases of solar cycle 21 and by Wind at 1 AU in a similar phase of solar activity cycle. We supplement these data by observations from other spacecraft (e. g., Voyagers 1 and 2, Pioneers 10 and 11, and others). Our data set consists of 130 events. We explore three different approaches. In the first, we work with ensemble averages, binning the results into radial segments of width 0.1 AU in the range 0.3 <= r(h) <= 1 AU. Doing this, we find that in the inner heliosphere the modeled average central axial field strength, [B(0)], varies with heliospheric distance r(h) as [B(0)] [nT] = 18.1 . r(h)(-1.64) [AU], and the average diameter increases quasi-linearly as [D] [AU] = 0.23 r(h)(1.14). The orientation of the axis of the underlying magnetic flux tube in our data set is generally found to lie along the east-west direction and in the ecliptic plane at all values of r(h), but there is considerable scatter about these average directions. In the second, we monitor the evolution of magnetic clouds in snapshot fashion, using seven spacecraft alignments. The results are in broad agreement with the statistics reported under step 1. In the final approach, we obtain the functional dependence of B0 and D predicted by an analytic expression for a freely expanding Lundquist flux tube. We find D to vary linearly with r(h), broadly similar to that obtained under approach 1. The maximum field strength scales as (--)(r)2 compared to a r(h)(-1.3) dependence obtained from statistics. We compare our findings with those of Bothmer and Schwenn (1998), who used a different methodology. The results obtained form a good background to the forthcoming Solar Terrestrial Relations Observatory (STEREO) and Sentinels missions and to multispacecraft studies of magnetic clouds. C1 Austrian Acad Sci, Inst Space Res, A-8042 Graz, Austria. Graz Univ, Inst Phys, Graz, Austria. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Max Planck Inst Solar Syst Res, D-3791 Katlenburg Lindau, Germany. RP Leitner, M (reprint author), Austrian Acad Sci, Inst Space Res, Schmiedlst 6, A-8042 Graz, Austria. EM martin.leitner@oeaw.ac.at RI Galvin, Antoinette/A-6114-2013; OI Moestl, Christian/0000-0001-6868-4152 NR 47 TC 31 Z9 31 U1 0 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 22 PY 2007 VL 112 IS A6 AR A06113 DI 10.1029/2006JA011940 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182YC UT WOS:000247538900002 ER PT J AU Baker, JG Campanelli, M Pretorius, F Zlochower, Y AF Baker, John G. Campanelli, Manuela Pretorius, Frans Zlochower, Yosef TI Comparisons of binary black hole merger waveforms SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT Interntional Meeting on New Frontiers in Numerical Ralativity CY JUL 17-21, 2006 CL Albert Einstein Inst, Potsdam, GERMANY HO Albert Einstein Inst ID INITIAL DATA; GRAVITATIONAL-WAVES AB This is a particularly exciting time for gravitational wave physics. Groundbased gravitational wave detectors are now operating at a sensitivity such that gravitational radiation may soon be directly detected, and recently several groups have independently made significant breakthroughs that have finally enabled numerical relativists to solve the Einstein field equations for coalescing black-hole binaries, a key source of gravitational radiation. The numerical relativity community is now in the position to begin providing simulated merger waveforms for use by the data analysis community, and it is therefore very important that we provide ways to validate the results produced by various numerical approaches. Here, we present a simple comparison of the waveforms produced by two very different, but equally successful approaches -the generalized harmonic gauge and the moving puncture methods. We compare waveforms of equal-mass black hole mergers with minimal or vanishing spins. The results show exceptional agreement for the final burst of radiation, with some differences attributable to small spins on the black holes in one case. C1 NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. Rochester Inst Technol, Sch Math Sci, Ctr Computat Relat & Gravitat, Rochester, NY 14623 USA. Univ Texas, Dept Phys & Astron, Ctr Gravitat Wave Astron, Brownsville, TX 78520 USA. Univ Alberta, Dept Phys, Edmonton, AB T6G 2G7, Canada. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RP Baker, JG (reprint author), NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. NR 29 TC 60 Z9 60 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 JUN 21 PY 2007 VL 24 IS 12 SI SI BP S25 EP S31 DI 10.1088/0264-9381/24/12/S03 PG 7 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 175WZ UT WOS:000247046000004 ER PT J AU Shinozuka, Y Clarke, AD Howell, SG Kapustin, VN McNaughton, CS Zhou, JC Anderson, BE AF Shinozuka, Yohei Clarke, Antony D. Howell, Steven G. Kapustin, Vladimir N. McNaughton, Cameron S. Zhou, Jingchuan Anderson, Bruce E. TI Aircraft profiles of aerosol microphysics and optical properties over North America: Aerosol optical depth and its association with PM2.5 and water uptake SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RESOLUTION IMAGING SPECTRORADIOMETER; GROUND-LEVEL PM2.5; UNITED-STATES; INTEGRATING NEPHELOMETER; SIZE DISTRIBUTION; LIGHT-ABSORPTION; REFRACTIVE-INDEX; MODIS; SCATTERING; DENSITY AB [1] Aerosol column optical depth (AOD) is related to the aerosol direct radiative effect and readily available as a satellite product. The mass of dry aerosol up to 2.5 mm aerodynamic, or PM2.5, is a common measure of surface aerosol pollution at selected regional sites. A link between these two parameters would provide a way to infer PM2.5 and its change over extensive regions observed by satellites. This requires determination of the response of aerosol dry mass to the widely variable influence of ambient humidity and its optical contribution to column AOD. During the INTEX-North America aircraft campaign, we obtained 72 profiles of visible aerosol light scattering up to 10 km and its response to water uptake. The ambient AODs determined from these measurements, and confirmed for three profiles near surface AERONET, were generally below 0.4 except in the presence of a humid boundary layer with high aerosol loading. The fraction of ambient AOD due to water uptake, Wf, was found to be 37 +/- 15% ( average and standard deviation). Boundary layer PM2.5 was estimated (PM2.5(proxy)) from low-altitude size distributions measured from the aircraft. Despite the large variety of vertical aerosol structure, the ambient AOD was found correlated with the PM2.5proxy with R-2 = 0.77, after 4% of data with AOD > 0.8 for > 90% RH were removed. Our results support the application of remote sensing to retrievals of surface PM2.5 mass. The wavelength dependence of ambient AOD was found to be less effective in stratifying the mass versus extinction relationship on the column integral basis than on a layer by layer basis. C1 Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. RP Shinozuka, Y (reprint author), Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. EM yohei@hawaii.edu NR 37 TC 37 Z9 37 U1 0 U2 17 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 2007 VL 112 IS D12 AR D12S20 DI 10.1029/2006JD007918 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 182WG UT WOS:000247534100003 ER PT J AU Hansen, CJ Paige, DA Bearman, G Furstenau, S Horn, J Mahoney, C Patrick, S Peters, G Scherbenski, J Shiraishi, L Zimmerman, W AF Hansen, Candice J. Paige, David A. Bearman, Gregory Furstenau, Steven Horn, Jennifer Mahoney, Colin Patrick, Steven Peters, Greg Scherbenski, Josh Shiraishi, Lori Zimmerman, Wayne TI SPADE: A rock-crushing and sample-handling system developed for Mars missions SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GUSEV CRATER; MERIDIANI-PLANUM; MARTIAN SURFACE; SPIRIT ROVER; BASALTIC ROCKS; SPECTROMETER; PATHFINDER; DUST; SOILS; WATER AB [1] A novel system has been developed to access and analyze the interior of rocks on Mars by crushing rocks. A miniature rock crusher has been prototyped along with a method for distribution of the fines and fragments produced by the rock crusher to inspection and analysis instruments. The science goals and advantages of this approach are substantial with respect to understanding the geologic and climate history of Mars via the investigation of its mineralogy and petrology. The system is described in detail, and results of various performance metrics are reported. Engineering considerations, constraints on functionality, fault tolerance, and its previously-planned deployment on the 2009 Mars Science Laboratory mission are described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. RP Hansen, CJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM candice.j.hansen@jpl.nasa.gov; dap@mars.ucla.edu NR 36 TC 3 Z9 3 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD JUN 21 PY 2007 VL 112 IS E6 AR E06008 DI 10.1029/2005JE002413 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 182XL UT WOS:000247537200001 ER PT J AU Sun, XH Sham, TK Rosenberg, RA Shenoy, GK AF Sun, X. H. Sham, T. K. Rosenberg, R. A. Shenoy, G. K. TI One-dimensional silicon-cadmium selenide heterostructures SO JOURNAL OF PHYSICAL CHEMISTRY C LA English DT Article ID EXCITED OPTICAL LUMINESCENCE; NANOWIRE BUILDING-BLOCKS; SEMICONDUCTOR NANOWIRES; CONTROLLED GROWTH; NANOCRYSTALS; SURFACE; NANOSTRUCTURES; MECHANISM; LOGIC; STEP AB We report the synthesis and characterization of 1D Si-CdSe heteronanostructures with different morphologies such as coaxial, biaxial, sandwiched, pattern wrapping, coiling, structures etc., via a one-step metal catalyzed thermal evaporation method. Both Si and CdSe exhibit single crystalline characteristics in the heterostructures, as revealed by scanning transmission electron microscopy. The Si nanowires formed directly from the Si substrate via the solid-liquid-solid process acts as the absorption site for CdSe deposition as well as the template for the formation of 1D Si-CdSe heterostructures. Time-resolved X-ray excited optical luminescence from the 1D Si-CdSe heteronanostructures reveals two main emission features at 530 and 637 nm with slow and fast decay lifetime, respectively. The 530 and 637 nm emission is associated with the Si and CdSe component of the heterostructures, respectively. C1 Univ Western Ontario, Dept Chem, London, ON N6A 5B7, Canada. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Sun, XH (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM xsun@arc.nasa.gov; tsham@uwo.ca RI Rosenberg, Richard/K-3442-2012; Sun, Xuhui /K-5689-2012 NR 36 TC 17 Z9 17 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1932-7447 J9 J PHYS CHEM C JI J. Phys. Chem. C PD JUN 21 PY 2007 VL 111 IS 24 BP 8475 EP 8482 DI 10.1021/jp071699z PG 8 WC Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 178IU UT WOS:000247215200014 ER PT J AU Borra, EF Seddiki, O Angel, R Eisenstein, D Hickson, P Seddon, KR Worden, SP AF Borra, Ermanno F. Seddiki, Omar Angel, Roger Eisenstein, Daniel Hickson, Paul Seddon, Kenneth R. Worden, Simon P. TI Deposition of metal films on an ionic liquid as a basis for a lunar telescope SO NATURE LA English DT Article ID MIRROR TELESCOPE; NANOPARTICLES; FRAGMENTATION; BEHAVIOR AB An optical/infrared telescope of 20 - 100 m aperture located on the Moon would be able to observe objects 100 to 1,000 times fainter than the proposed next generation of space telescopes(1). The infrared region of the spectrum is particularly important for observations of objects at redshifts z > 7. The apparent simplicity and low mass of a liquid mirror telescope, compared with a traditional pointable glass mirror, suggest that the concept should be considered further. A previously proposed liquid mirror telescope, based upon a spinning liquid metallic alloy(2), is not appropriate for infrared applications, which will require a liquid below 130 K. Here we report the successful coating of an ionic liquid with silver. The surface is smooth and the silver coating is stable on a timescale of months. The underlying ionic liquid does not evaporate in a vacuum and remains liquid down to a temperature of 175 K. Given that there are similar to 10(6) simple and similar to 10(18) ternary ionic liquids, it should be possible to synthesize liquids with even lower melting temperatures. C1 Univ Laval, Ctr Opt Photon & Laser, Dept Phys Genie Phys & Opt, Quebec City, PQ G1K 7P4, Canada. Univ Arizona, Steward Observ, Tucson, AZ USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Queens Univ Belfast, QUILL Ctr, Belfast BT9 5AG, Antrim, North Ireland. NASA, Ames Res Ctr, Off Director, Moffett Field, CA 94035 USA. RP Borra, EF (reprint author), Univ Laval, Ctr Opt Photon & Laser, Dept Phys Genie Phys & Opt, Quebec City, PQ G1K 7P4, Canada. EM borra@phy.ulaval.ca NR 27 TC 144 Z9 150 U1 6 U2 73 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 21 PY 2007 VL 447 IS 7147 BP 979 EP 981 DI 10.1038/nature05909 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 180NU UT WOS:000247373100041 PM 17581579 ER PT J AU Gliozzi, M Sambruna, RM Foschini, L AF Gliozzi, Mario Sambruna, Rita M. Foschini, Luigi TI A Chandra view of naked active galactic nuclei SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : nuclei; X-rays : galaxies ID BROAD-LINE REGIONS; SEYFERT-2 GALAXIES; ASCA OBSERVATIONS; MASS ACCRETION; XMM-NEWTON; VARIABILITY; LUMINOSITY; EMISSION; OBJECTS; ORIGIN AB We present the first X-ray observations of three sources belonging to a new AGN class: the naked AGNs. Based on optical spectroscopic studies, these sources appear as classical type 2 ( obscured) AGNs, with only narrow emission lines. However, long-term optical monitoring campaigns, carried out over more than two decades, show that the same sources are strongly variable, like type 1 ( unobscured) AGNs. Based on short Chandra observations, the sources appear to be fairly bright in the X-rays, with typical Seyfert 1 values for the photon index ( Gamma similar to 1.8) and without significant intrinsic absorption, supporting the conclusion that some bright AGNs may genuinely lack a broad-line region. Future broadband studies as well as deeper X-ray observations, probing both the spectral and the temporal properties of the naked AGNs, are crucial to shed light on the central engine of these sources, which may be representative of a large class of AGNs. C1 George Mason Univ, Fairfax, VA 22030 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. IASF Bologna, INAF, I-40129 Bologna, Italy. RP Gliozzi, M (reprint author), George Mason Univ, Fairfax, VA 22030 USA. RI Foschini, Luigi/H-3833-2012 OI Foschini, Luigi/0000-0001-8678-0324 NR 39 TC 20 Z9 20 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 2007 VL 662 IS 2 BP 878 EP 883 DI 10.1086/518024 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178UO UT WOS:000247245800008 ER PT J AU Tavecchio, F Maraschi, L Wolter, A Cheung, CC Sambruna, RM Urry, CM AF Tavecchio, F. Maraschi, L. Wolter, A. Cheung, C. C. Sambruna, R. M. Urry, C. M. TI Chandra and Hubble Space Telescope observations of gamma-ray blazars: Comparing jet emission at small and large scales SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : jets; quasars : individual (0208-512,0954+556,1229-021; 2251+158); X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; RADIO-LOUD QUASARS; SPECTRAL ENERGY-DISTRIBUTIONS; BL LACERTAE OBJECTS; X-RAY; PARTICLE-ACCELERATION; EXTRAGALACTIC JETS; KILOPARSEC SCALES; OPTICAL-EMISSION; DISK CONNECTION AB We present new Chandra and HST data for four gamma-ray blazars selected on the basis of radio morphology with the aim of revealing X-ray and optical emission from their jets at large scales. All the sources have been detected. Spectral energy distributions ( SEDs) of the large-scale jets are obtained as well as new X-ray spectra for the blazar cores. Modeling for each object the core ( subparsec scale) and large-scale ( greater than or similar to 100 kpc) jet SEDs, we derive the properties of the same jet at the two scales. The comparison of speeds and powers at different scales supports a simple scenario for the dynamics and propagation of high-power relativistic jets. C1 Osserv Astron Brera, INAF, I-23807 Merate, LC, Italy. Osserv Astron Brera, INAF, I-20121 Milan, Italy. Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Yale Univ, Yale Ctr Astron & Astrophys, New Haven, CT 06520 USA. RP Tavecchio, F (reprint author), Osserv Astron Brera, INAF, I-23807 Merate, LC, Italy. RI Urry, Claudia/G-7381-2011; OI Urry, Claudia/0000-0002-0745-9792; Wolter, Anna/0000-0001-5840-9835 NR 71 TC 30 Z9 30 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 JUN 20 PY 2007 VL 662 IS 2 BP 900 EP 908 DI 10.1086/518085 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178UO UT WOS:000247245800011 ER PT J AU Dwek, E Galliano, F Jones, AP AF Dwek, Eli Galliano, Frederic Jones, Anthony P. TI The evolution of dust in the early universe with applications to the galaxy SDSS J1148+5251 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; galaxies : evolution; galaxies : formation; galaxies : high-redshift; galaxies : individual (SDSS J114816.64+525150.3); galaxies : starburst; infrared : galaxies; infrared : general ID DENSE MOLECULAR GAS; HIGH-REDSHIFT; STAR-FORMATION; INTERSTELLAR DUST; OPTICAL-PROPERTIES; MU-M; QUASARS; EMISSION; Z-GREATER-THAN-6; SUBMILLIMETER AB Dusty hyperluminous galaxies in the early universe provide unique environments for studying the role of massive stars in the formation and destruction of dust. At redshifts above similar to 6, when the universe was less than similar to 1 Gyr old, dust could have only condensed in the explosive ejecta of Type II supernovae (SNe), since most of the progenitors of the asymptotic giant branch stars, the major alternative source of interstellar dust, did not have time to evolve off the main sequence since the onset of star formation. In this paper we present analytical models for the evolution of the gas, dust, and metals in high-redshift galaxies, with a special application to SDSS J1148+5251 ( hereafter J1148+5251), a hyperluminous quasar at z = 6.4. We find that an average SN must condense at least 1 M-circle dot of dust to account for the observed dust mass in J1148+5251. Observationally, it is in excess of the largest dust yield of less than or similar to 0.02 M-circle dot found thus far in the ejecta of any SN. If future observations find this to be a typical SN dust yield, then additional processes, such as accretion onto preexisting grains or condensation around the active galactic nucleus, will need to be invoked to account for the large amount of dust in this and similar objects. The galaxy's star formation history is still uncertain, and current observations of the gas, metal, and dust contents of J1148+5251 can be reproduced by either an intensive and short burst of star formation (psi greater than or similar to 10(3) M-circle dot yr(-1)) with a duration of less than or similar to 10(8) yr or a much lower star formation rate (psi approximate to 100 M-circle dot yr(-1)) occurring over the lifetime of the galaxy. C1 NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. Inst Astrophys Spatiale, F-91405 Orsay, France. RP Dwek, E (reprint author), NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA. EM eli.dwek@nasa.gov RI Dwek, Eli/C-3995-2012 OI Jones, Anthony/0000-0003-0577-6425; NR 45 TC 147 Z9 147 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 2007 VL 662 IS 2 BP 927 EP 939 DI 10.1086/518430 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178UO UT WOS:000247245800014 ER PT J AU Petre, R Hwang, U Holt, SS Safi-Harb, S Williams, RM AF Petre, R. Hwang, U. Holt, S. S. Safi-Harb, S. Williams, R. M. TI The X-ray structure and spectrum of the pulsar wind nebula surrounding PSR B0540-69.3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (0540-69.3); supernova remnants; X-rays : general ID LARGE-MAGELLANIC-CLOUD; SUPERNOVA REMNANT G21.5-0.9; CRAB-NEBULA; CHANDRA OBSERVATIONS; ASCA OBSERVATIONS; BRAKING INDEX; 3C 58; EMISSION; SHELL; PHASE AB We present the first spatially resolved spectral study of an extragalactic pulsar wind nebula ( PWN), that surrounding the 50 ms pulsar B0540 - 69.3 in the Large Magellanic Cloud, using the ACIS instrument on board the Chandra X-ray Observatory. The spectral properties of the PWN change at a radius of similar to 5", corresponding to a shell detected optically in [ O III]. Within this radius, the spectra are well characterized by a simple power law, whose spectral index varies strongly with radius, so that the effective size of the nebula decreases with increasing photon energy. These X-ray measurements support the idea that the [ O III] shell represents an outer skin surrounding the wind nebula, analogous to that seen in the Crab Nebula. We use the size-energy relation and radial variability of the X-ray spectral index to estimate PWN parameters, including the radial dependence of the magnetic field, and the average ratio of electromagnetic to particle flux. C1 NASA, Goddard Space Flight Ctr, X Ray Astrophys Lab, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. FW Olin Coll, Needham, MA 02492 USA. Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada. Univ Illinois, Dept Astron, Urbana, IL 61801 USA. RP Petre, R (reprint author), NASA, Goddard Space Flight Ctr, X Ray Astrophys Lab, Greenbelt, MD 20771 USA. EM rob@milkyway.gsfc.nasa.gov NR 54 TC 16 Z9 16 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 2007 VL 662 IS 2 BP 988 EP 997 DI 10.1086/518019 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178UO UT WOS:000247245800020 ER PT J AU Turner, NJ Quataert, E Yorke, HW AF Turner, N. J. Quataert, E. Yorke, H. W. TI Photon bubbles in the circumstellar envelopes of young massive stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; instabilities; MHD; radiative transfer; stars : early-type; stars : formation ID RADIATION MAGNETOHYDRODYNAMICS CODE; DENSE INTERSTELLAR CLOUDS; FLUX-LIMITED DIFFUSION; 2 SPACE DIMENSIONS; H2O MASERS; MAGNETIC-FIELDS; ASTROPHYSICAL FLOWS; ARRAY OBSERVATIONS; FORMING REGIONS; WATER MASERS AB We show that the optically thick dusty envelopes surrounding young high-mass stars are subject to the photon bubble instability. The infrared radiation passing through the envelope amplifies magnetosonic disturbances, with growth rates in our local numerical radiation MHD calculations that are consistent with a linear analysis. Modes with wavelengths comparable to the gas pressure scale height grow by more than 2 orders of magnitude in 1000 yr, reaching nonlinear amplitudes within the envelope lifetime. If the magnetic pressure in the envelope exceeds the gas pressure, the instability develops into trains of propagating shocks. Radiation escapes readily through the low-density material between the shocks, enabling accretion to continue despite the Eddington limit imposed by the dust opacity. The supersonic motions arising from the photon bubble instability can help explain the large velocity dispersions of hot molecular cores, while conditions in the shocked gas are suitable for maser emission. We conclude that the photon bubble instability may play a key role in the formation of massive stars. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. RP Turner, NJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM neal.turner@jpl.nasa.gov NR 44 TC 13 Z9 13 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 20 PY 2007 VL 662 IS 2 BP 1052 EP 1058 DI 10.1086/513179 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178UO UT WOS:000247245800026 ER PT J AU Willingale, R O'Brien, PT Osborne, JP Godet, O Page, KL Goad, MR Burrows, DN Zhang, B Rol, E Gehrels, N Chincarini, G AF Willingale, R. O'Brien, P. T. Osborne, J. P. Godet, O. Page, K. L. Goad, M. R. Burrows, D. N. Zhang, B. Rol, E. Gehrels, N. Chincarini, G. TI Testing the standard fireball model of gamma-ray bursts using late X-ray afterglows measured by Swift SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; ISM : jets and outflows; radiation mechanisms : nonthermal ID 25 APRIL 1998; UNUSUAL SUPERNOVA; LIGHT CURVES; XRF 050416A; EMISSION; GRB-030329; DISCOVERY; ENERGY; PARAMETERS; GRB-060206 AB We show that all X- ray decay curves of gamma-ray bursts ( GRBs) measured by Swift can be fitted using one or two components, both of which have exactly the same functional form comprised of an early falling exponential phase followed by a power-law decay. The first component contains the prompt gamma-ray emission and the initial X- ray decay. The second component appears later, has a much longer duration, and is present for approximate to 80% of GRBs. It most likely arises from the external shock that eventually develops into the X- ray afterglow. In the remaining approximate to 20% of GRBs the initial X- ray decay of the first component fades more slowly than the second and dominates at late times to form an afterglow. The temporal decay parameters and gamma/X-ray spectral indices derived for 107 GRBs are compared to the expectations of the standard fireball model including a search for possible "jet breaks.'' For similar to 50% of GRBs the observed afterglow is in accord with the model, but for the rest the temporal and spectral indices do not conform to the expected closure relations and are suggestive of continued, late, energy injection. We identify a few possible jet breaks, but there are many examples where such breaks are predicted but are absent. The time T(a) at which the exponential phase of the second component changes to a final power-law decay afterglow is correlated with the peak of the gamma-ray spectrum, E(peak). This is analogous to the Ghirlanda relation, indicating that this time is in some way related to optically observed break times measured for pre-Swift bursts. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Osserv Astron Brera, INAF, I-23807 Merate, LC, Italy. RP Willingale, R (reprint author), Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. RI Gehrels, Neil/D-2971-2012 NR 58 TC 182 Z9 184 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2007 VL 662 IS 2 BP 1093 EP 1110 DI 10.1086/517989 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178UO UT WOS:000247245800030 ER PT J AU Ofek, EO Cenko, SB Gal-Yam, A Fox, DB Nakar, E Rau, A Frail, DA Kulkarni, SR Price, PA Schmidt, BP Soderberg, AM Peterson, B Berger, E Sharon, K Shemmer, O Penprase, BE Chevalier, RA Brown, PJ Burrows, DN Gehrels, N Harrison, F Holland, ST Mangano, V McCarthy, PJ Moon, DS Nousek, JA Persson, SE Piran, T Sari, R AF Ofek, E. O. Cenko, S. B. Gal-Yam, A. Fox, D. B. Nakar, E. Rau, A. Frail, D. A. Kulkarni, S. R. Price, P. A. Schmidt, B. P. Soderberg, A. M. Peterson, B. Berger, E. Sharon, K. Shemmer, O. Penprase, B. E. Chevalier, R. A. Brown, P. J. Burrows, D. N. Gehrels, N. Harrison, F. Holland, S. T. Mangano, V. McCarthy, P. J. Moon, D.-S. Nousek, J. A. Persson, S. E. Piran, T. Sari, R. TI GRB 060505: A possible short-duration gamma-ray burst in a star-forming region at a redshift of 0.09 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts ID K-CORRECTIONS; HOST GALAXY; LUMINOSITY; DISTRIBUTIONS; SUPERNOVAE; AFTERGLOW; PROGENITORS; ULTRAVIOLET; GRB-050709; EVOLUTION AB On 2006 May 5, a 4 s duration, low-energy, similar to 10(49) erg, gamma-ray burst ( GRB) was observed, spatially associated with a z = 0894 galaxy. Here we report the discovery of the GRB optical afterglow and observations of its environment using Gemini South, the Hubble Space Telescope ( HST), Chandra, Swift, and the Very Large Array. The optical afterglow of this GRB is spatially associated with a prominent star-forming region in the Sc-type galaxy 2dFGRS S173Z112. Its proximity to a star-forming region suggests that the progenitor delay time, from birth to explosion, is smaller than similar to 10 Myr. Our HST deep imaging rules out the presence of a supernova brighter than an absolute magnitude of about - 11 ( or - 12.6 in the case of maximal extinction) at about 2 weeks after the burst and limits the ejected mass of radioactive (56)Ni to be less than about 2 x 10(-4) M(circle dot) ( assuming no extinction). Although it was suggested that GRB 060505 may belong to a new class of long-duration GRBs with no supernova, we argue that the simplest interpretation is that the physical mechanism responsible for this burst is the same as that for short-duration GRBs. C1 CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Mt Stromlo & Siding Spring Observ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Princeton Univ, Princeton, NJ 08544 USA. Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Tel Aviv Univ, Wise Observ, IL-69978 Tel Aviv, Israel. Pomona Coll, Dept Phys & Astron, Claremont, CA 91711 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ist Astrofis Spaziale & Fis Cosm Palermo, INAF, I-90146 Palermo, Italy. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. RP Ofek, EO (reprint author), CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. RI Gehrels, Neil/D-2971-2012; OI Schmidt, Brian/0000-0001-6589-1287; Shemmer, Ohad/0000-0003-4327-1460; Schmidt, Brian/0000-0002-8538-9195 NR 55 TC 62 Z9 64 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 JUN 20 PY 2007 VL 662 IS 2 BP 1129 EP 1135 DI 10.1086/518082 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178UO UT WOS:000247245800033 ER PT J AU Farinelli, R Titarchuk, L Frontera, F AF Farinelli, Ruben Titarchuk, Lev Frontera, Filippo TI The hard X-ray tails in neutron star low-mass X-ray binaries: BeppoSAX observations and possible theoretical explanation of the case of GX 17+2 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; stars : individual (GX 17+2); stars : neutron; X-rays : binaries ID QUASI-PERIODIC OSCILLATIONS; CONVERGING FLUID-FLOW; BROAD-BAND SPECTRUM; CIRCINUS X-1; BLACK-HOLES; COMPTONIZATION; ACCRETION; EMISSION; BRANCHES AB We report results of a new spectral analysis of two BeppoSAX observations of the Z source GX 17+2. In one of the observations, the source exhibited a power-lawYlike hard (> 30 keV) X-ray tail, which was described in a previous work with a hybrid Comptonization model. Recent high-energy observations with INTEGRAL of a sample of low-mass X-ray binaries including both Z and atoll classes have shown that dynamical ( bulk) Comptonization of soft photons is a possible alternative mechanism for producing hard X-ray tails in such systems. We start from the INTEGRAL results and exploit the broadband capability of BeppoSAX to better investigate the physical processes at work. We use GX 17+2 as a representative case. Moreover, we suggest that weakening (or disappearance) of the hard X-ray tail can be explained by increasing radiation pressure that originates at the surface of the neutron star (NS). As a result, the high radiation pressure stops the bulk inflow, and consequently, this radiation feedback from the NS surface leads to quenching of the dynamical (bulk) Comptonization. C1 Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy. George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. USN, Res Lab, High Energy Space Environm Branch, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Astroparticle Phys Lab, Greenbelt, MD 20771 USA. INAF, Ist Astrofis Spaziale & Fis Cosm Bologna, I-40129 Bologna, Italy. RP Farinelli, R (reprint author), Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy. EM farinelli@fe.infn.it; ltitarchuk@ssd5.nrl.navy.mil; frontera@fe.infn.it NR 29 TC 16 Z9 16 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 20 PY 2007 VL 662 IS 2 BP 1167 EP 1172 DI 10.1086/516707 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178UO UT WOS:000247245800037 ER PT J AU Mainzer, AK Roellig, TL Saumon, D Marley, MS Cushing, MC Sloan, GC Kirkpatrick, JD Leggett, SK Wilson, JC AF Mainzer, A. K. Roellig, Thomas L. Saumon, D. Marley, Mark S. Cushing, Michael C. Sloan, G. C. Kirkpatrick, J. Davy Leggett, S. K. Wilson, John C. TI Moderate-resolution Spitzer infrared spectrograph observations of M, L, and T dwarfs SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : stars; stars : late-type; stars : low-mass; brown dwarfs ID ALL-SKY SURVEY; BINARY BROWN DWARF; SPECTRAL TYPE-L; EPSILON-INDI-B; SPACE-TELESCOPE; SOLAR NEIGHBORHOOD; GLIESE 229B; ATMOSPHERIC CHEMISTRY; SPECTROSCOPIC SURVEY; GIANT PLANETS AB We present 10-19 mu m moderate-resolution spectra of 10 M dwarfs, one L dwarf, and two T dwarf systems obtained with the Infrared Spectrograph ( IRS) on board the Spitzer Space Telescope. The IRS allows us to examine molecular spectroscopic features/lines at moderate spectral resolution in a heretofore untapped wavelength regime. These R = lambda/Delta lambda similar to 600 spectra allow for a more detailed examination of clouds and nonequilibrium chemistry, as well as the molecular features of H2O, NH3, and other trace molecular species that are the hallmarks of these objects. A cloud-free model best fits our mid-infrared spectrum of the T1 dwarf epsilon Indi Ba, and we find that the NH3 feature in epsilon Indi Bb is best explained by a nonequilibrium abundance due to vertical transport in its atmosphere. We examined a set of objects ( mostly M dwarfs) in multiple systems to look for evidence of emission features, which might indicate an atmospheric temperature inversion, as well as trace molecular species; however, we found no evidence of either. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. Gemini Observ, Hilo, HI 96720 USA. Univ Virginia, Charlottesville, VA 22903 USA. RP Mainzer, AK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM amainzer@jpl.nasa.gov; thomas.l.roellig@nasa.gov; dsaumon@lanl.gov; mmarley@mail.arc.nasa.gov; mcushing@as.arizona.edu; sloan@isc.astro.cornell.edu; davy@ipac.caltech.edu; sleggett@gemini.edu; jcw6z@virginia.edu RI Marley, Mark/I-4704-2013; OI Leggett, Sandy/0000-0002-3681-2989 NR 64 TC 17 Z9 17 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2007 VL 662 IS 2 BP 1245 EP 1253 DI 10.1086/516561 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178UO UT WOS:000247245800046 ER PT J AU Williams, PE Hathaway, DH Cuntz, M AF Williams, P. E. Hathaway, D. H. Cuntz, M. TI Solar Rossby wave "hills" identified as supergranules SO ASTROPHYSICAL JOURNAL LA English DT Article DE convection; Sun : helioseismology; Sun : photosphere; Sun : rotation; turbulence; waves ID DIFFERENTIAL ROTATION; VELOCITY-FIELDS; OSCILLATIONS; SUN; PHOTOSPHERE; ATMOSPHERE; IMAGER; DYNAMO AB We explore the nature of "hills" observed on the solar surface that had previously been attributed to Rossby waves. We investigate the solar hills phenomenon by analyzing the output from a synthetic model based solely on the observed solar photospheric convection spectrum. We show that the characteristics of these hills can be explained by the corrugation of the surface produced by the radial flows of the convection. The hills in our simulations are dominated by supergranules, a well-known component of solar convection. Rossby waves have been predicted to exist within the Sun and may play an important role in the dynamics of the solar interior, including the Sun's differential rotation and magnetic dynamo. Our study suggests, however, that the hills observed at the solar limb do not confirm the existence of solar Rossby waves. C1 Univ Texas, Dept Phys, Arlington, TX 76019 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Williams, PE (reprint author), Univ Texas, Dept Phys, Arlington, TX 76019 USA. EM pwilliams@uta.edu; david.hathaway@nasa.gov; cuntz@uta.edu NR 26 TC 3 Z9 3 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2007 VL 662 IS 2 BP L135 EP L138 DI 10.1086/519456 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178VS UT WOS:000247248800022 ER PT J AU Weisz, E Li, J Li, JL Zhou, DK Huang, HL Goldberg, MD Yang, P AF Weisz, Elisabeth Li, Jun Li, Jinlong Zhou, Daniel K. Huang, Hung-Lung Goldberg, Mitchell D. Yang, Ping TI Cloudy sounding and cloud-top height retrieval from AIRS alone single field-of-view radiance measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MODIS; AIRS/AMSU/HSB; PARAMETERS; PRODUCTS; SURFACE AB High-spectral resolution measurements from the Atmospheric Infrared Sounder (AIRS) onboard the EOS ( Earth Observing System) Aqua satellite provide unique information about atmospheric state, surface and cloud properties. This paper presents an AIRS alone single field-of-view (SFOV) retrieval algorithm to simultaneously retrieve temperature, humidity and ozone profiles under all weather conditions, as well as cloud-top pressure (CTP) under cloudy skies. For optically thick cloud conditions the above-cloud soundings are derived, whereas for clear skies and optically thin cloud conditions the profiles are retrieved from 0.005 hPa down to the earth's surface. Initial validation has been conducted by using the operational MODIS ( Moderate Resolution Imaging Spectroradiometer) product, ECMWF ( European Centre for Medium-Range Weather Forecasts) analysis fields and radiosonde observations (RAOBs). These inter-comparisons clearly demonstrate the potential of this algorithm to process data from high-spectral infrared (IR) sounder instruments. C1 Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI 53706 USA. NASA, Langley Res Ctr, Chem & Dynam Branch, Sci Directorate, Hampton, VA 23681 USA. NOAA, NESDIS, Satellite Meteorol & Climatol Div, Off Res & Applicat, Camp Springs, MD USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. RP Weisz, E (reprint author), Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI 53706 USA. EM elisabeth.weisz@ssec.wisc.edu RI Yang, Ping/B-4590-2011; Goldberg, Mitch/F-5589-2010; Li, Jun/H-3579-2015 OI Li, Jun/0000-0001-5504-9627 NR 19 TC 34 Z9 35 U1 1 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 20 PY 2007 VL 34 IS 12 AR L12802 DI 10.1029/2007GL030219 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 182VV UT WOS:000247533000005 ER PT J AU Eastwood, JP Phan, TD Mozer, FS Shay, MA Fujimoto, M Retino, A Hesse, M Balogh, A Lucek, EA Dandouras, I AF Eastwood, J. P. Phan, T.-D. Mozer, F. S. Shay, M. A. Fujimoto, M. Retino, A. Hesse, M. Balogh, A. Lucek, E. A. Dandouras, I. TI Multi-point observations of the Hall electromagnetic field and secondary island formation during magnetic reconnection SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PLASMA SHEET; CLUSTER OBSERVATIONS; GEOTAIL OBSERVATIONS; FLUX ROPE; COLLISIONLESS RECONNECTION; EARTHS MAGNETOSPHERE; SEPARATRIX REGION; DIFFUSION REGION; ELECTRIC-FIELD; X-LINE AB A key feature of collisionless magnetic reconnection is the formation of Hall magnetic and electric field structure in the vicinity of the diffusion region. Here we present multi-point Cluster observations of a reconnection event in the near-Earth magnetotail where the diffusion region was nested by the Cluster spacecraft; we compare observations made simultaneously by different spacecraft on opposite sides of the magnetotail current sheet. This allows the spatial structure of both the electric and magnetic field to be probed. It is found that, close to the diffusion region, the magnetic field displays a symmetric quadrupole structure. The Hall electric field is symmetric, observed to be inwardly directed on both sides of the current sheet. It is large (similar to 40 mV m(-1)) on the earthward side of the diffusion region, but substantially weaker on the tailward side, suggesting a reduced reconnection rate reflected by a similar reduction in E-y. A small-scale magnetic flux rope was observed in conjunction with these observations. This flux rope, observed very close to the reconnection site and entrained in the plasma flow, may correspond to what have been termed secondary islands in computer simulations. The core magnetic field inside the flux rope is enhanced by a factor of 3, even though the lobe guide field is negligible. Observations of the electric field inside the magnetic island show extremely strong (similar to 100 mV m(-1)) fields which may play a significant role in the particle dynamics during reconnection. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. Inst Space & Astronaut Sci, Solar Terr Phys Grp, Kanagawa, Japan. Swedish Inst Space Phys, Uppsala, Sweden. NASA, Goddard Space Flight Ctr, Geospace Phys Branch, Lab Solar & Space Phys, Greenbelt, MD 20771 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London, England. UPS, CNRS, CESR, Toulouse, France. RP Eastwood, JP (reprint author), Univ Calif Berkeley, Space Sci Lab, 7 Gauss Way, Berkeley, CA 94720 USA. EM eastwood@ssl.berkeley.edu RI Hesse, Michael/D-2031-2012; Shay, Michael/G-5476-2013; NASA MMS, Science Team/J-5393-2013; OI NASA MMS, Science Team/0000-0002-9504-5214; Dandouras, Iannis/0000-0002-7121-1118; Retino, Alessandro/0000-0001-5824-2852 NR 58 TC 86 Z9 89 U1 2 U2 7 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 20 PY 2007 VL 112 IS A6 AR A06235 DI 10.1029/2006JA012158 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 182XY UT WOS:000247538500005 ER PT J AU Prigent, C Papa, F Aires, F Rossow, WB Matthews, E AF Prigent, C. Papa, F. Aires, F. Rossow, W. B. Matthews, E. TI Global inundation dynamics inferred from multiple satellite observations, 1993-2000 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MODERN METHANE EMISSIONS; WETLAND DYNAMICS; RADAR ALTIMETER; VEGETATION; CLIMATE; SCALE; EMISSIVITIES; VARIABILITY; RESOLUTION; FEEDBACK AB [1] Wetlands and surface waters are recognized to play important roles in climate, hydrologic and biogeochemical cycles, and availability of water resources. Until now, quantitative, global time series of spatial and temporal dynamics of inundation have been unavailable. This study presents the first global estimate of monthly inundated areas for 1993 - 2000. The data set is derived from a multisatellite method employing passive microwave land surface emissivities calculated from SSM/I and ISCCP observations, ERS scatterometer responses, and AVHRR visible and near-infrared reflectances. The satellite data are used to calculate inundated fractions of equal area grid cells (0.25 degrees x 0.25 degrees at the equator), taking into account the contribution of vegetation to the passive microwave signal. Global inundated area varies from a maximum of 5.86 x 10(6) km(2) ( average for 1993 - 2000) to a mean minimum of 2.12 x 10(6) km(2). These values are considered consistent with existing independent, static inventories. The new multisatellite estimates also show good agreement with regional high-resolution SAR observations over the Amazon basin. The seasonal and interannual variations in inundation have been evaluated against rain rate estimates from the Global Precipitation Climatology Project (GPCP) and water levels in wetlands, lakes, and rivers measured with satellite altimeters. The inundation data base is now being used for hydrology modeling and methane studies in GCMs. C1 CNRS, Observ Paris, Lab Etud Rayonnement & Mat Astrophys, F-75014 Paris, France. Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Univ Paris 06, CNRS, Inst Pierre Simon Laplace, Meteorol Dynam Lab, F-75252 Paris, France. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Prigent, C (reprint author), CNRS, Observ Paris, Lab Etud Rayonnement & Mat Astrophys, 61 Av Observ, F-75014 Paris, France. EM catherine.prigent@obspm.fr; fpapa@giss.nasa.gov; filipe.aires@lmd.jussieu.fr; wrossow@giss.nasa.gov; ematthews@giss.nasa.gov RI Papa, Fabrice/D-3695-2009; Rossow, William/F-3138-2015 OI Papa, Fabrice/0000-0001-6305-6253; NR 50 TC 154 Z9 158 U1 3 U2 37 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 19 PY 2007 VL 112 IS D12 AR D12107 DI 10.1029/2006JD007847 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 182WE UT WOS:000247533900003 ER PT J AU Hall, DK Riggs, GA AF Hall, Dorothy K. Riggs, George A. TI Accuracy assessment of the MODIS snow products SO HYDROLOGICAL PROCESSES LA English DT Article; Proceedings Paper CT 63rd Eastern Snow Conference CY JUN 07-09, 2006 CL Univ Delaware, Newark, DE HO Univ Delaware DE MODIS; snow covered area; snow products; Terra; Aqua ID RESOLUTION IMAGING SPECTRORADIOMETER; COVER PRODUCTS; RIVER-BASIN; VALIDATION; MODEL; ALGORITHM; AREA; STREAMFLOW; DEPLETION; SYSTEM AB A suite of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow products at various spatial and temporal resolutions from the Terra satellite has been available since February 2000. Standard products include daily and 8-day composite 500 m resolution swath and tile products (which include fractional snow cover (FSC) and snow albedo), and 0.05 degrees resolution products on a climate-modelling grid (CMG) (which also include FSC). These snow products (from Collection 4 (C4) reprocessing) are mature and most have been validated to varying degrees and are available to order through the National Snow and Ice Data Center. The overall absolute accuracy of the well-studied 500 m resolution swath (MODI0_L2) and daily tile (MOD10A1) products is similar to 93%, but varies by land-cover type and snow condition. The most frequent errors are due to snow/cloud discrimination problems, however, improvements in the MODIS cloud mask, an input product, have occurred in 'Collection 5' reprocessing. Detection of very thin snow (<1 cm thick) can also be problematic. Validation of MOD10_L2 and MOD10A1 applies to all higher-level products because all the higher-level products are all created from these products. The composited products may have larger errors due, in part, to errors propagated from daily products. Recently, new products have been developed. A fractional snow cover algorithm for the 500 m resolution products was developed, and is part of the C5 daily swath and tile products; a monthly CMG snow product at 0.05 degrees resolution and a daily 0.25 degrees resolution CMG snow product are also now available. Similar, but not identical products are also produced from the MODIS on the Aqua satellite, launched in May 2002, but the accuracy of those products has not yet been assessed in detail. Published in 2007 by John Wiley & Sons, Ltd. C1 NASA, Cryospher Sci Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Hall, DK (reprint author), NASA, Cryospher Sci Branch, Goddard Space Flight Ctr, Code 614-1, Greenbelt, MD 20771 USA. EM dorothy.k.hall@nasa.gov RI Hall, Dorothy/D-5562-2012 NR 55 TC 296 Z9 317 U1 4 U2 69 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD JUN 15 PY 2007 VL 21 IS 12 BP 1534 EP 1547 DI 10.1002/hyp.6715 PG 14 WC Water Resources SC Water Resources GA 181LN UT WOS:000247438300002 ER PT J AU Sawyer, WB Mirin, AA AF Sawyer, William B. Mirin, Arthur A. TI The implementation of the finite-volume dynamical core in the community atmosphere model SO JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS LA English DT Article; Proceedings Paper CT 1st Indo/Germany Conference on PDE, Scientific Computing and Optimization in Applications CY SEP 08-10, 2004 CL Univ Trier, Dept Math, Trier, GERMANY SP German Res Fdn, Indian Natl Sci Acad HO Univ Trier, Dept Math DE atmospheric dynamics; primitive equations; finite-volume methods; parallel computing ID PERFORMANCE AB A distributed memory message-passing parallel implementation of a finite-volume discretization of the primitive equations in the community atmosphere model (CAM) 3.0 is presented. These 3-D equations can be decoupled into a set of 2-D equations by the introduction of a floating vertical coordinate, resulting in considerable potential parallelism. Subsequent analysis of the data dependencies-in particular those arising from the polar singularity of the latitude-longitude coordinate system-suggests that two separate domain decompositions should be employed, each tailored for a different pan of the model. The implementation requires that data be periodically redistributed between these two decompositions. Furthermore, data from nearest neighbors are kept in halo regions, which are updated between iterations. These data movements are optimized through one-sided communication primitives and multithreading. The resulting algorithm is shown to scale to very large machine configurations, even for relatively coarse resolutions. (C) 2006 Elsevier B.V. All rights reserved. C1 ETH, Swiss Fed Inst Technol, Seminar Appl Math, CH-8092 Zurich, Switzerland. NASA, Goddard Space Flight Ctr, GMAO, Greenbelt, MD 20771 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sawyer, WB (reprint author), ETH, Swiss Fed Inst Technol, Seminar Appl Math, Ramistr 101, CH-8092 Zurich, Switzerland. EM sawyer@sam.math.ethz.ch NR 16 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0427 J9 J COMPUT APPL MATH JI J. Comput. Appl. Math. PD JUN 15 PY 2007 VL 203 IS 2 BP 387 EP 396 DI 10.1016/j.cam.2006.04.015 PG 10 WC Mathematics, Applied SC Mathematics GA 166XJ UT WOS:000246413800006 ER PT J AU Dye, JE Bateman, MG Christian, HJ Defer, E Grainger, CA Hall, WD Krider, EP Lewis, SA Mach, DM Merceret, FJ Willett, JC Willis, PT AF Dye, J. E. Bateman, M. G. Christian, H. J. Defer, E. Grainger, C. A. Hall, W. D. Krider, E. P. Lewis, S. A. Mach, D. M. Merceret, F. J. Willett, J. C. Willis, P. T. TI Electric fields, cloud microphysics, and reflectivity in anvils of Florida thunderstorms SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DIAGNOSTIC-ANALYSIS; NETWORK AB [1] A coordinated aircraft - radar project that investigated the electric fields, cloud microphysics, and radar reflectivity of thunderstorm anvils near Kennedy Space Center is described. Measurements from two cases illustrate the extensive nature of the microphysics and electric field observations. As the aircraft flew from the edges of anvils into the interior, electric fields very frequently increased abruptly from similar to 1 to > 10 kV m(1) even though the particle concentrations and radar reflectivity increased smoothly. The abrupt increase in field usually occurred when the aircraft entered regions with a reflectivity of 10 - 15 dBZ. We suggest that the abrupt increase in electric field was because the charge advection from the convective core did not occur across the entire breadth of the anvil and because the advection of charge was not constant in time. Also, some long-lived anvils showed enhancement of electric field and reflectivity far downwind of the convective core. Screening layers were not detected near the edges of the anvils. Comparisons of electric field magnitude with particle concentration or reflectivity for a combined data set that included all anvil measurements showed a threshold behavior. When the average reflectivity, such as in a 3-km cube, was less than approximately 5 dBZ, the electric field magnitude was < 3 kV m(1). Based on these findings, the Volume Averaged Height Integrated Radar Reflectivity (VAHIRR) is now being used by the NASA, the Air Force, the and Federal Aviation Administration in new Lightning Launch Commit Criteria as a diagnostic for high electric fields in anvils. C1 Univ Alabama, Huntsville, AL 35899 USA. Univ Space Res Assoc, Huntsville, AL USA. Observ Paris, F-75014 Paris, France. Univ N Dakota, Grand Forks, ND 58201 USA. Univ Arizona, Tucson, AZ USA. Univ Colorado, NOAA, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NASA, Kennedy Space Ctr, FL USA. NOAA, Cooperat Marine & Atmospher Sci, Miami, FL USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Dye, JE (reprint author), 3450 Mitchell Lane,FL3, Boulder, CO 80307 USA. EM dye@ucar.edu RI Willis, Paul/I-7034-2013 OI Willis, Paul/0000-0003-4506-9813 NR 37 TC 17 Z9 17 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 15 PY 2007 VL 112 IS D11 AR D11215 DI 10.1029/2006JD007550 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 180MS UT WOS:000247369500001 ER PT J AU Tsyganenko, NA Sitnov, MI AF Tsyganenko, N. A. Sitnov, M. I. TI Magnetospheric configurations from a high-resolution data-based magnetic field model SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID DAWN-DUSK ASYMMETRY; IN-FLIGHT DETERMINATION; INNER MAGNETOSPHERE; RING CURRENT; BIRKELAND CURRENTS; GEOMAGNETIC STORMS; BOUNDARY-LAYER; CURRENT SHEET; TAIL CURRENT; WIND AB [1] We present first results of the magnetospheric magnetic field modeling, based on large sets of spacecraft data and a high-resolution expansion for the field of equatorial currents. In this approach, the field is expanded into a sum of orthogonal basis functions of different scales, capable to reproduce arbitrary radial and azimuthal variations of the geomagnetic field, including its noon-midnight and dawn-dusk asymmetries. Combined with the existing method to model the global field of Birkeland currents, the new approach offers a natural way to consistently represent the field of both the tail and symmetrical/ partial ring currents. The proposed technique is particularly effective in the modeling of the inner magnetosphere, a stumbling block for the first-principle approaches. The new model has been fitted to various subsets of data from Geotail, Polar, Cluster, IMP-8, and GOES-8, GOES-9, GOES-10, and GOES-12 spacecraft, corresponding to different activity levels, solar wind IMF conditions, and storm phases. The obtained maps of the magnetic field reproduce most basic features of the magnetospheric structure, their dependence on the geomagnetic activity and interplanetary conditions, as well as characteristic changes associated with the main and recovery phases of magnetic storms. C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Space Weather Lab, Greenbelt, MD 20771 USA. Univ Maryland, Inst Res Elect & Appl Phys, College Pk, MD 20742 USA. RP Tsyganenko, NA (reprint author), NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Space Weather Lab, Code 674, Greenbelt, MD 20771 USA. EM nikolai.tsyganenko@gsfc.nasa.gov; sitnov@umd.edu RI Tsyganenko, Nikolai/J-7377-2012; Sitnov, Mikhail/H-2316-2016 OI Tsyganenko, Nikolai/0000-0002-5938-1579; NR 47 TC 63 Z9 63 U1 0 U2 6 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 15 PY 2007 VL 112 IS A6 AR A06225 DI 10.1029/2007JA012260 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 180NK UT WOS:000247371600007 ER PT J AU Hart, RC Herring, GC Balla, RJ AF Hart, Roger C. Herring, G. C. Balla, R. Jeffrey TI Pressure measurement in supersonic air flow by differential absorptive laser-induced thermal acoustics SO OPTICS LETTERS LA English DT Article ID VELOCIMETRY; TEMPERATURE; GRATINGS; THERMOMETRY; PULSE AB Nonintrusive, off-body flow barometry in Mach 2 airflow has been demonstrated in a large-scale supersonic wind tunnel using seedless laser-induced thermal acoustics (LITA). The static pressure of the gas flow is determined with a novel differential absorption measurement of the ultrasonic sound produced by the LITA pump process. Simultaneously, the streamwise velocity and static gas temperature of the same spatially resolved sample volume were measured with this nonresonant time-averaged LITA technique. Mach number, temperature, and pressure have 0.2%, 0.4%, and 4% rms agreement, respectively, in comparison with known free-stream conditions. (C) 2007 Optical Society of America C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Herring, GC (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM g.c.herring@larc.naso.gov NR 11 TC 7 Z9 7 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 15 PY 2007 VL 32 IS 12 BP 1689 EP 1691 DI 10.1364/OL.32.001689 PG 3 WC Optics SC Optics GA 191PX UT WOS:000248144600031 PM 17572748 ER PT J AU Goetz, S Steinberg, D Dubayah, R Blair, B AF Goetz, Scott Steinberg, Daniel Dubayah, Ralph Blair, Bryan TI Laser remote sensing of canopy habitat heterogeneity as a predictor of bird species richness in an eastern temperate forest, USA SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE abundance; biodiversity; diversity; general additive models; habitat; heterogeneity; lidar; regression trees; remote sensing; species richness ID LANDSCAPE OCCUPANCY; MAPPING VEGETATION; SPATIAL-PATTERNS; TROPICAL FOREST; FRAGMENTATION; BIODIVERSITY; LIDAR; ENERGY; NDVI; DISTRIBUTIONS AB Habitat heterogeneity has long been recognized as a fundamental variable indicative of species diversity, in terms of both richness and abundance. Satellite remote sensing data sets can be useful for quantifying habitat heterogeneity across a range of spatial scales. Past remote sensing analyses of species diversity have largely been limited to correlative studies based on the use of vegetation indices or derived land cover maps. A relatively new form of laser remote sensing (lidar) provides another means to acquire information on habitat heterogeneity. Here we examine the efficacy of lidar metrics of canopy structural diversity as predictors of bird species richness in the temperate forests of Maryland, USA. Canopy height, topography and the vertical distribution of canopy elements were derived from lidar imagery of the Patuxent National Wildlife Refuge and compared to bird survey data collected at referenced grid locations. The canopy vertical distribution information was consistently found to be the strongest predictor of species richness, and this was predicted best when stratified into guilds dominated by forest, scrub, suburban and wetland species. Similar lidar variables were selected as primary predictors across guilds. Generalized linear and additive models, as well as binary hierarchical regression trees produced similar results. The lidar metrics were also consistently better predictors than traditional remotely sensed variables such as canopy cover, indicating that lidar provides a valuable resource for biodiversity research applications. (C) 2006 Elsevier Inc. All rights reserved. C1 Woods Hole Res Ctr, Falmouth, MA 02540 USA. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Goetz, S (reprint author), Woods Hole Res Ctr, Falmouth, MA 02540 USA. EM sgoetz@whrc.org RI Blair, James/D-3881-2013; Goetz, Scott/A-3393-2015; Beckley, Matthew/D-4547-2013; OI Goetz, Scott/0000-0002-6326-4308; Steinberg, Daniel/0000-0003-1769-2261 NR 43 TC 146 Z9 152 U1 7 U2 74 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 15 PY 2007 VL 108 IS 3 BP 254 EP 263 DI 10.1016/j.rse.2006.11.016 PG 10 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 172RE UT WOS:000246820800004 ER PT J AU Shvedova, AA Kisin, ER Murray, AR Gorelik, O Arepalli, S Castranova, V Young, SH Gao, F Tyurina, YY Oury, TD Kagan, VE AF Shvedova, Anna A. Kisin, Elena R. Murray, Ashley R. Gorelik, Olga Arepalli, Sivaram Castranova, Vincent Young, Shih-Hong Gao, Fel Tyurina, Yulia Y. Oury, Tim D. Kagan, Valerian E. TI Vitamin E deficiency enhances pulmonary inflammatory response and oxidative stress induced by single-walled carbon nanotubes in C57BL/6 mice SO TOXICOLOGY AND APPLIED PHARMACOLOGY LA English DT Article DE carbon nanotubes; vitamin E deficiency; pulmonary inflammatory response; oxidative stress; antioxidants; inflammatory cells ID EXTRACELLULAR-SUPEROXIDE DISMUTASE; MOUSE LUNG; ALPHA-TOCOPHEROL; ANTIOXIDANT; PLASMA; SOD; INJURY; HYPEROXIA; EXPOSURE; ASBESTOS AB Exposure of mice to single-walled carbon nanotubes (SWCNTs) induces an unusually robust pulmonary inflammatory response with an early onset of fibrosis, which is accompanied by oxidative stress and antioxidant depletion. The role of specific components of the antioxidant protective system, specifically vitamin E, the major lipid-soluble antioxidant, in the SWCNT-induced reactions has not been characterized. We used C57BL/6 mice, maintained on vitamin E-sufficient or vitamin E-deficient diets, to explore and compare the pulmonary inflammatory reactions to aspired SWCNTs. The vitamin E-cleficient diet caused a 90-fold depletion of a-tocopherol in the lung tissue and resulted in a significant decline of other antioxidants (GSH, ascorbate) as well as accumulation of lipid peroxidation products. A greater decrease of pulmonary antioxidants was detected in SWCNT-treated vitamin E-deficient mice as compared to controls. Lowered levels of antioxidants in vitamin E-deficient mice were associated with a higher sensitivity to SWCNT-induced acute inflammation (total number of inflammatory cells, number of polymorphonuclear leukocytes, released LDH, total protein content and levels of pro-inflammatory cytokines, TNF-alpha and IL-6) and enhanced profibrotic responses (elevation of TGF-beta and collagen deposition). Exposure to SWCNTs markedly shifted the ratio of cleaved to full-length extracellular superoxide dist-nutase (EG-SOD). Piven that pulmonary levels of vitamin E can be manipulated through diet, its effects on SWCNT-induced inflammation may be of practical importance in optimizing protective strategies. (c) 2007 Elsevier Inc. All rights reserved. C1 NIOSH, Hlth Effect Lab Div, Morgantown, WV USA. Univ Pittsburgh, Ctr Free Rad & Antioxidant Hlth, Dept Environm & Occupat Med, Pittsburgh, PA USA. NIOSH, HELD, Pathol Physiol Res Branch, Morgantown, WV USA. GBTech Inc, Lockheed Martin Corp, NASA JSC, Mat & Proc Branch & Nanotube Team, Houston, TX USA. Univ Pittsburgh, Grad Sch Publ Hlth, Dept Pathol, Pittsburgh, PA USA. Univ Pittsburgh, Grad Sch Publ Hlth, Ctr Free Rad & Antioxidant Hlth, Pittsburgh, PA USA. RP Shvedova, AA (reprint author), NIOSH, Hlth Effect Lab Div, Morgantown, WV USA. EM atsI@cdc.gov; kagan@pitt.edu RI Arepalli, Sivaram/A-5372-2010 FU NHLBI NIH HHS [HL70755, R01 HL063700, R01 HL063700-07, R01 HL070755, R01 HL070755-04]; NIOSH CDC HHS [OH008282, R01 OH008282] NR 50 TC 98 Z9 104 U1 2 U2 9 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0041-008X EI 1096-0333 J9 TOXICOL APPL PHARM JI Toxicol. Appl. Pharmacol. PD JUN 15 PY 2007 VL 221 IS 3 BP 339 EP 348 DI 10.1016/j.taap.2007.03.018 PG 10 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 179GX UT WOS:000247278800009 PM 17482224 ER PT J AU Hu, YX AF Hu, Yongxiang TI Depolarization ratio-effective lidar ratio relation: Theoretical basis for space lidar cloud phase discrimination SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MULTIPLE-SCATTERING; WATER CLOUDS; POLARIZATION; BACKSCATTER; EXTINCTION AB This paper introduces a technique for cloud phase discrimination based on linear polarization measurements made by space-based lidar. Using CALIPSO Level 2 data products, a 3-dimensional histogram of the depolarization ratio, delta, and the effective lidar ratio, S-c,S-eff, is derived for all optically thick clouds measured during July 2006. A second histogram is derived using data from early November, 2006. By analysis of the relationship between d and Sc, eff, and an examination of their spatial correlations, water clouds, ice clouds with randomly oriented particles and ice clouds with horizontally oriented particles are clearly differentiated. For clouds having the same depolarization ratios, the effective lidar ratios of water clouds are significantly smaller than the effective lidar ratios of ice clouds comprised of randomly oriented particles. The variance of the depolarization ratios within water clouds is significantly larger than it is in ice clouds containing horizontally oriented particles. Depolarization ratios and effective lidar ratios are negatively correlated for water clouds, and positively correlated for ice clouds with horizontally-oriented particles. For the optically thick ice clouds observed by CALIPSO, approximately half contain some fraction ( up to 100%) of horizontally oriented particles. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Hu, YX (reprint author), NASA, Langley Res Ctr, MS 475, Hampton, VA 23681 USA. EM yongxiang.hu-1@nasa.gov RI Hu, Yongxiang/K-4426-2012 NR 9 TC 38 Z9 39 U1 1 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 JUN 14 PY 2007 VL 34 IS 11 AR L11812 DI 10.1029/2007GL029584 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 180ML UT WOS:000247368700003 ER PT J AU Burger, MH Sittler, EC Johnson, RE Smith, HT Tucker, OJ Shematovich, VI AF Burger, M. H. Sittler, E. C., Jr. Johnson, R. E. Smith, H. T. Tucker, O. J. Shematovich, V. I. TI Understanding the escape of water from Enceladus SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SATURNS MAGNETOSPHERE; CROSS-SECTIONS; NEUTRAL CLOUD; PLASMA; ATMOSPHERE; SPECTROMETER; MORPHOLOGY; COLLISIONS; DISCOVERY; DYNAMICS AB [1] On 14 July 2005, Cassini passed within 175 km of Enceladus' surface enabling a direct in situ measurement of water escaping from the surface by the Ion and Neutral Mass Spectrometer (INMS) and the observation of a stellar occultation by the Ultraviolet Spectrometer (UVIS). We have developed a three-dimensional, Monte Carlo neutral model to simultaneously model the INMS and UVIS measurements of water gas density and column density, respectively. The data are consistent with a two-component atmosphere; the first with a weak, distributed source on the surface which, if global, has a source rate of similar to 8 x 10(25) H2O/s, and the second with a much larger source localized at the south pole with a source rate similar to 10(28) H2O/s. This latter source is possibly coincident with the "tiger stripe'' series of fractures revealed by the Imaging Science Subsystem instrument where the ice was measured to be warmer than the surrounding regions by the Composite Infrared Spectrometer instrument. We estimate the plasma mass loading rate due to interaction between the plume and magnetospheric plasma is 2 - 3 kg/s for a plume source of 10(28) H2O/s. Pickup of water group ions in the plume slows down the plasma to similar to 10 km/s relative to Enceladus in the region of, and downstream of, the south polar plume. This is consistent with the mass loading rate inferred from magnetic field perturbations detected during the Cassini flyby and suggests an additional source may be needed to explain the plasma flow deflections detected by the Cassini Plasma Spectrometer. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Virginia, Charlottesville, VA USA. Russian Acad Sci, Dept Stellar Phys & Evolut, Inst Astron, Moscow, Russia. RP Burger, MH (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM mburger@pop600.gsfc.nasa.gov RI Shematovich, Valery/E-4670-2014; Smith, Howard/H-4662-2016 OI Smith, Howard/0000-0003-3537-3360 NR 42 TC 61 Z9 61 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 14 PY 2007 VL 112 IS A6 AR A06219 DI 10.1029/2006JA012086 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 180NJ UT WOS:000247371400003 ER PT J AU Liu, XH Penner, JE Das, BY Bergmann, D Rodriguez, JM Strahan, S Wang, MH Feng, Y AF Liu, Xiaohong Penner, Joyce E. Das, Bigyani Bergmann, Dan Rodriguez, Jose M. Strahan, Susan Wang, Minghuai Feng, Yan TI Uncertainties in global aerosol simulations: Assessment using three meteorological data sets SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID GENERAL-CIRCULATION MODEL; TROPOSPHERIC SULFUR CYCLE; CLOUD LIQUID WATER; PARTICLE-SIZE DISTRIBUTION; COMMUNITY CLIMATE MODEL; MICROWAVE IMAGER SSM/I; BLACK CARBON; MINERAL DUST; OPTICAL-THICKNESS; SULFATE AEROSOLS AB [1] Current global aerosol models use different physical and chemical schemes and parameters, different meteorological fields, and often different emission sources. Since the physical and chemical parameterization schemes are often tuned to obtain results that are consistent with observations, it is difficult to assess the true uncertainty due to meteorology alone. Under the framework of the NASA global modeling initiative (GMI), the differences and uncertainties in aerosol simulations ( for sulfate, organic carbon, black carbon, dust, and sea salt) solely due to different meteorological fields are analyzed and quantified. Three meteorological data sets available from the NASA Goddard Data Assimilation Office (DAO) general circulation model (GCM), the Goddard Institute for Space Studies (GISS) GCM, version II' and the NASA Goddard Global Modeling and Assimilation Office (GMAO), finite-volume GCM (FVGCM) are used to drive the same aerosol model. The global sulfate and mineral dust burdens with FVGCM fields are 40% and 20% less than those with DAO and GISS fields, respectively, due to its larger precipitation. Meanwhile, the sea salt burden predicted with FVGCM fields is 56% and 43% higher than those with DAO and GISS, respectively, due to its stronger convection especially over the Southern Hemispheric Ocean. Sulfate concentrations at the surface in the Northern Hemisphere extratropics and in the middle to upper troposphere differ by a factor of 3 between the three meteorological data sets. The agreement between model calculated and observed aerosol concentrations in the surface source regions is similar for all three meteorological data sets. Away from the source regions, however, the comparisons with observations differ greatly for DAO, FVGCM, and GISS, and the performance of the model using different meteorological data sets varies depending on the site and the compared species. Sensitivity simulations with the NASA GEOS-4 assimilated fields show that the interannual variability of aerosol concentrations can be higher than a factor of 2 depending on the location and season, which is generally, however, smaller than the differences due to using different meteorological data sets. Global annual average aerosol optical depth at 550 nm is 0.120 - 0.131 for the three meteorological data sets. However, the contributions from different aerosol components to this total optical depth differ significantly, which reflects differences in the aerosol spatial distributions. The global annual average anthropogenic and all-sky aerosol direct forcing at the top-of-the atmosphere is estimated to be - 0.75, - 0.35, and - 0.40 W m(-2) for DAO, FVGCM, and GISS fields, respectively. Regional differences can be much larger ( by a factor of 4 - 5) in the tropics over the ocean and in the polar regions. C1 Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. RP Liu, XH (reprint author), Pacific NW Natl Lab, Atmospher Sci & Global Change Div, 3200 Q Ave,MSIN K9-24, Richland, WA 99352 USA. EM xiaohong.liu@pnl.gov RI Strahan, Susan/H-1965-2012; Rodriguez, Jose/G-3751-2013; Penner, Joyce/J-1719-2012; Liu, Xiaohong/E-9304-2011; Das, Bigyani/P-4064-2014; Bergmann, Daniel/F-9801-2011; Wang, Minghuai/E-5390-2011 OI Rodriguez, Jose/0000-0002-1902-4649; Liu, Xiaohong/0000-0002-3994-5955; Bergmann, Daniel/0000-0003-4357-6301; Wang, Minghuai/0000-0002-9179-228X NR 131 TC 39 Z9 39 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 13 PY 2007 VL 112 IS D11 AR D11212 DI 10.1029/2006JD008216 PG 41 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 180MQ UT WOS:000247369200010 ER PT J AU Waquet, F Goloub, P Deuze, JL Leon, JF Auriol, F Verwaerde, C Balois, JY Francois, P AF Waquet, F. Goloub, P. Deuze, J.-L. Leon, J.-F. Auriol, F. Verwaerde, C. Balois, J.-Y. Francois, P. TI Aerosol retrieval over land using a multiband polarimeter and comparison with path radiance method SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OPTICAL-PROPERTIES; POLARIZED REFLECTANCE; CLAMS EXPERIMENT; SATELLITE; ALGORITHM; DEPTH; OCEAN; MODIS; TEMPERATURE; ABSORPTION AB [1] This study focuses on the development of a new approach to retrieve aerosol properties over land, based on the use of multispectral polarized measurements (0.67 - 2.2 mu m). We use the measurements of the airborne MICROPOL polarimeter during regional aircraft field experiments located in France and dedicated to the study of aerosol ( pollutant and mineral dust particles) and surface properties. We have developed a multiband polarization algorithm (MBP) and compared the retrievals with both a path radiance algorithm and Sun photometer data. It is shown that surface polarized reflectance exhibits only a small spectral variation for forward scattering geometries (3% on average, 15 - 20% for a single view and scattering angle < 110 degrees). The atmospheric contribution at 2.2 mu m is small for aerosol optical thicknesses (AOTs) up to 0.15 at 0.67 mu m and can be accounted for in the retrieval of surface properties. The 2.2 mu m channel therefore enables us to accurately derive the surface polarization in the shorter MICROPOL bands. For the observations we have made, the surface model developed for the analysis of the Polarization and Directionality of the Earth Reflectance ( POLDER) measurements overestimates surface polarization from a few to fifty percents. This leads to AOT underestimation by a factor two. For the pollutant aerosol cases (0.065 < AOT < 0.20), the MBP approach retrieves AOT with an accuracy of 0.03, over both natural and urban surfaces. However, this method remains only weakly sensitive to coarse mode particles and fails when dust particles associated with large AOTs (0.5) are considered. C1 Univ Lille 1, CNRS, UMR 8518, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. RP Waquet, F (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM fwaquet@giss.nasa.gov NR 43 TC 20 Z9 24 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 13 PY 2007 VL 112 IS D11 AR D11214 DI 10.1029/2006JD008029 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 180MQ UT WOS:000247369200007 ER PT J AU Tian, L Heymsfield, GM Li, LH Srivastava, RC AF Tian, Lin Heymsfield, Gerald M. Li, Lihua Srivastava, Ramesh C. TI Properties of light stratiform rain derived from 10- and 94-GHz airborne Doppler radars measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TRMM PRECIPITATION RADAR; SIZE DISTRIBUTION; SQUALL-LINE; VERTICAL INCIDENCE; FREQUENCY; SPECTRA; DISTRIBUTIONS; ATTENUATION; ALGORITHMS; PARAMETER AB [1] This paper presents an initial investigation of using airborne Doppler radar operating at 10 and 94 GHz to measure the light stratiform rain (<= 5 mm hr(-1)). It has been shown that the combination of 10 and 94 GHz is more sensitive to resolve the raindrop size distribution (RSD) in light rain than that of 14 and 35 GHz. A case of light stratiform rain over southern Florida is examined in detail in this study. Techniques for retrieving the profiles of a Gamma raindrop size distribution ( RSD), vertical air velocity, and attenuation by precipitation and water vapor are presented. This approach uses the difference of the Doppler velocity at two frequencies and yields both RSD and the vertical air motion. The approach is primarily applicable to rain rates less than 5 mm hr(-1). The magnitudes of the retrieved RSD are similar to those found in ground-based observations of light stratiform rain. The retrieved vertical winds with downdrafts below about 3 km and weak updraft above are similar to what has been observed in widespread stratiform rain with melting band. The sensitivities of the retrieval to Gamma shape parameter are discussed. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Tian, L (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. EM tian@agnes.gsfc.nasa.gov NR 39 TC 15 Z9 15 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-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 12 PY 2007 VL 112 IS D11 AR D11211 DI 10.1029/2006JD008144 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 180MP UT WOS:000247369100003 ER PT J AU Matsui, T Beltran-Przekurat, A Pielke, RA Niyogi, D Coughenour, MB AF Matsui, Toshihisa Beltran-Przekurat, Adriana Pielke, Roger A., Sr. Niyogi, Dev Coughenour, Michael B. TI Continental-scale multiobservation calibration and assessment of Colorado State University Unified Land Model by application of Moderate Resolution Imaging Spectroradiometer (MODIS) surface albedo SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES LA English DT Article ID LEAF-AREA INDEX; CLIMATE MODEL; PARAMETER-ESTIMATION; SPATIAL VARIABILITY; BIOSPHERE MODEL; GLOBAL CLIMATE; PRODUCTS; VEGETATION; VALIDATION; ENERGY AB [1] This study attempts to establish the first continental-scale multiobservation calibration and assessment of a land surface model (LSM) over the conterminous United States by using the Colorado State University Unified Land Model (CSU ULM) within the NASA GSFC's Land Information System and the Parameter Estimation ( PEST) model. This study aims to calibrate the vegetation and soil optical parameters in different landcover classes by comparing model-predicted surface albedo and those derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) ( including black- and white-sky albedo for visible and near-infrared band). The sum of squared deviations (Y) between model- and MODIS-derived albedo is iteratively reduced via the Gauss-Marquardt-Levenberg (GML) algorithm. The first calibration process ( 1) reduced Y by about 80% for noncalibrated as well as calibrated seasons and years, ( 2) revealed the functional biases related to diffuse-radiation upscattering parameters in two-stream canopy radiation scheme ( which was fixed before the second calibration), and ( 3) shows that the parameter related to the leaf angle distribution function could not be tuned. The second calibration was implemented from the lessons learned from the first calibration, and results in the more realistic convergence of the parameters. After calibration, the summertime surface energy budget simulated by offline ULM changed significantly over the less vegetated regions; for example, net shortwave radiation and available energy increased by more than 40 W m(-2) and radiative temperature increased by more than 1.6 K in the postcalibrated experiment. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO USA. Univ Colorado, Cooperat Inst Res Environm Sci, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. Purdue Univ, Dept Agron, W Lafayette, IN 47906 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47906 USA. Colorado State Univ, Nat Resource & Environm Lab, Ft Collins, CO 80523 USA. RP Matsui, T (reprint author), NASA, Goddard Space Flight Ctr, Code 913-1, Greenbelt, MD 20771 USA. EM matsui@agnes.gsfc.nasa.gov; adrian@cires.colordo.edu; pielkesr@cires.colorado.edu; dniyogi@purdue.edu; mikec@nrel.colostate.edu RI Pielke, Roger/A-5015-2009 NR 52 TC 14 Z9 15 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-BIOGEO JI J. Geophys. Res.-Biogeosci. PD JUN 12 PY 2007 VL 112 IS G2 AR G02028 DI 10.1029/2006JG000229 PG 19 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 180MU UT WOS:000247369700001 ER PT J AU Collado-Vega, YM Kessel, RL Shao, X Boller, RA AF Collado-Vega, Y. M. Kessel, R. L. Shao, X. Boller, R. A. TI MHD flow visualization of magnetopause boundary region vortices observed during high-speed streams SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID KELVIN-HELMHOLTZ INSTABILITY; INTERPLANETARY MAGNETIC-FIELD; GEOTAIL OBSERVATIONS; MAGNETOSPHERIC BOUNDARY; MAGNETOTAIL BOUNDARY; SIMULATION; DEPENDENCE; SUBSTORMS; VORTEX; WAVES AB [ 1] We present statistics for a total of 304 vortices found near the ecliptic plane on the magnetopause flanks, using simulated magnetohydrodynamics (MHD) data driven by real solar wind conditions. The study concentrates on 9 hours, from 29 March, 2000 UT to 30 March, 0500 UT, during the onset of a high-speed stream that existed from 29 March to 5 April 2002. Magnetopause crossings seen by the Geotail spacecraft for the 9-hour time interval were also analyzed and compared with the MHD simulation to validate our results. Vortices were classified by solar wind input provided by the Wind satellite located 60 - 80 R-E upstream from Earth. Two hundred seventy-three of the vortices were generated under northward Interplanetary Magnetic Field ( IMF), and 31 were generated under southward IMF. The vortices generated under northward IMF were more prevalent on the dawnside than on the duskside and were substantially less ordered on the dawnside than on the duskside. Most of the vortices were large in scale, up to 10 R-E, and with a rotation axis closely aligned with the Z(SM) direction. They rotated preferentially clockwise on the dawnside, and counterclockwise on the duskside. Those generated under southward IMF were less ordered, fewer in number, and also smaller in diameter. Significant vortex activity occurred on the nightside region of the magnetosphere for these southward cases in contrast to the northward IMF cases on which most of the activity was on the magnetopause flanks. The IMF is primarily northward for our time interval, and the development of these vortices with their rotation preference depending on their local time position suggest that a Kelvin-Helmholtz (KH) instability is likely present. C1 NASA, Goddard Space Flight Ctr, Heliospher Phys Lab, Greenbelt, MD 20771 USA. Univ Puerto Rico, Dept Phys, Mayaguez, PR USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Adv Data Management & Anal Branch, Greenbelt, MD 20771 USA. RP Collado-Vega, YM (reprint author), NASA, Goddard Space Flight Ctr, Heliospher Phys Lab, Code 672, Greenbelt, MD 20771 USA. EM yaireska.m.colladovega@nasa.gov; ramona.l.kessel@nasa.gov; xi.shao@nasa.gov; ryan.a.boller@nasa.gov RI Collado-Vega, Yaireska/D-4679-2012 NR 34 TC 18 Z9 20 U1 1 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 JUN 12 PY 2007 VL 112 IS A6 AR A06213 DI 10.1029/2006JA012104 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 180NH UT WOS:000247371200004 ER PT J AU Tigelaar, DM Meador, MAB Bennett, WR AF Tigelaar, Dean M. Meador, Mary Ann B. Bennett, William R. TI Composite electrolytes for lithium batteries: Ionic liquids in APTES cross-linked polymers SO MACROMOLECULES LA English DT Article ID CONDUCTIVITY AB Solvent-free polymer electrolytes were made consisting of Li+ and pyrrolidinium salts of trifluoromethanesulfonimide added to a series of hyperbranched poly(ethylene oxide)s (PEO). The polymers were connected by triazine linkages and cross-linked by a sol-gel process to provide mechanical strength. These electrolytes are more conductive than those made with high molecular weight PEO imbibed with ionic liquids at ambient temperatures, due to the amorphous nature of the polymer. The connecting PEO groups were varied to help understand the effects of polymer structure on electrolyte conductivity in the presence of ionic liquids. Polymers were also made that contain poly(dimethylsiloxane) groups, which provide increased flexibility without interacting with lithium ions. When large amounts of ionic liquid are added, there is little dependence of conductivity on the polymer structure. However, when smaller amounts of ionic liquid are added, the inherent conductivity of the polymer becomes a factor. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Tigelaar, DM (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM dean.m.tigelaar@gre.nasa.gov OI Meador, Mary Ann/0000-0003-2513-7372 NR 23 TC 50 Z9 50 U1 2 U2 42 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUN 12 PY 2007 VL 40 IS 12 BP 4159 EP 4164 DI 10.1021/ma062804q PG 6 WC Polymer Science SC Polymer Science GA 177FH UT WOS:000247138500014 ER PT J AU Odenwald, SF Green, JL AF Odenwald, Sten F. Green, James L. TI Forecasting the impact of an 1859-caliber superstorm on geosynchronous Earth-orbiting satellites: Transponder resources SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS LA English DT Article ID CARRINGTON FLARE; SOLAR; EVENTS; STORM AB [1] We calculate the economic impact on the existing geosynchronous Earth-orbiting satellite population of an 1859-caliber superstorm event were it to occur between 2008 and 2018 during the next solar activity cycle. From a detailed model for transponder capacity and leasing, we have investigated the total revenue loss over the entire solar cycle, as a function of superstorm onset year and intensity. Our Monte Carlo simulations of 1000 possible superstorms, of varying intensity and onset year, suggest that the minimum revenue loss could be of the order of $30 billion. The losses would be larger than this if more that 20 satellites are disabled, if future launch rates do not keep up with the expected rate of retirements, or if the number of spare transponders falls below similar to 30%. Consequently, revenue losses can be significantly reduced below $30 billion if the current satellite population undergoes net growth beyond 300 units during Solar Cycle 24 and a larger margin of unused transponders is maintained. C1 [Odenwald, Sten F.; Green, James L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Odenwald, Sten F.] QSS Grp Inc, Lanham, MD USA. RP Odenwald, SF (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM odenwald@astronomycafe.net NR 22 TC 7 Z9 7 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1542-7390 J9 SPACE WEATHER JI Space Weather PD JUN 12 PY 2007 VL 5 IS 6 AR S06002 DI 10.1029/2006SW000262 PG 16 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 261JE UT WOS:000253074100001 ER PT J AU Deming, D Richardson, LJ Harrington, J AF Deming, Drake Richardson, L. Jeremy Harrington, Joseph TI 3.8-mu m photometry during the secondary eclipse of the extrasolar planet HD 209458b SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE techniques : photometric; eclipses; stars : individual : HD 209458; planetary systems; infrared : general ID INFRARED ARRAY CAMERA; HOT JUPITERS; THERMAL EMISSION; SPACE-TELESCOPE; HD-209458; SPECTRA AB We report infrared photometry of the extrasolar planet HD 209458b during the time of secondary eclipse (planet passing behind the star). Observations were acquired during two secondary eclipses at the NASA Infrared Telescope Facility (IRTF) in 2003 September. We used a circular variable filter (1.5 per cent bandpass) centred at 3.8 mu m to isolate the predicted flux peak of the planet at this wavelength. Residual telluric absorption and instrument variations were removed by offsetting the telescope to nearby bright comparison stars at a high temporal cadence. Our results give a secondary eclipse depth of 0.0013 +/- 0.0011, not yet sufficient precision to detect the eclipse, whose expected depth is similar to 0.002 -0.003. We here elucidate the current observational limitations to this technique, and discuss the approach needed to achieve detections of hot Jupiter secondary eclipses at 3.8 mu m from the ground. C1 Goddard Space Flight Ctr, Planetary Syst Lab, Greenbelt, MD 20771 USA. Goddard Space Flight Ctr, Exoplanet & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. RP Deming, D (reprint author), Goddard Space Flight Ctr, Planetary Syst Lab, Code 693, Greenbelt, MD 20771 USA. EM ddeming@pop600.gsfc.nasa.gov; richardsonlj@stars.gsfc.nasa.gov; jharring@physics.ucf.edu RI Harrington, Joseph/E-6250-2011 NR 19 TC 21 Z9 21 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUN 11 PY 2007 VL 378 IS 1 BP 148 EP 152 DI 10.1111/j.1365-2966.2007.11754.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 177TN UT WOS:000247175500027 ER PT J AU Greaves, JS Fischer, DA Wyatt, MC Beichman, CA Bryden, G AF Greaves, J. S. Fischer, D. A. Wyatt, M. C. Beichman, C. A. Bryden, G. TI Predicting the frequencies of diverse exo-planetary systems SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE circumstellar matter; planetary systems : formation; planetary systems : protoplanetary discs ID MAIN-SEQUENCE STARS; T-TAURI STARS; EXTRASOLAR PLANETS; GIANT PLANETS; DEBRIS DISCS; KUIPER-BELT; HOST STARS; METALLICITY; JUPITER; SEARCH AB Extrasolar planetary systems range from hot Jupiters out to icy comet belts more distant than Pluto. We explain this diversity in a model where the mass of solids in the primordial circumstellar disc dictates the outcome. The star retains measures of the initial heavy-element (metal) abundance that can be used to map solid masses on to outcomes, and the frequencies of all classes are correctly predicted. The differing dependences on metallicity for forming massive planets and low-mass cometary bodies are also explained. By extrapolation, around two-thirds of stars have enough solids to form Earth-like planets, and a high rate is supported by the first detections of low-mass exo-planets. C1 Univ St Andrews, Scottish Univ Phys Alliance Phys & Astron, St Andrews KY16 9SS, Fife, Scotland. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Greaves, JS (reprint author), Univ St Andrews, Scottish Univ Phys Alliance Phys & Astron, N Haugh, St Andrews KY16 9SS, Fife, Scotland. EM jsg5@st-andrews.ac.uk NR 32 TC 16 Z9 16 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUN 11 PY 2007 VL 378 IS 1 BP L1 EP L5 DI 10.1111/j.1745-3933.2007.00315.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 177TN UT WOS:000247175500001 ER PT J AU Mishchenko, MI Geogdzhayev, IV AF Mishchenko, Michael I. Geogdzhayev, Igor V. TI Satellite remote sensing reveals regional tropospheric aerosol trends SO OPTICS EXPRESS LA English DT Article ID GLOBAL AEROSOL; OPTICAL DEPTH; RADIATIVE PROPERTIES; SOLAR-RADIATION; EARTHS SURFACE; RETRIEVALS; OCEAN; CLIMATE; VALIDATION; ATMOSPHERE AB The Global Aerosol Climatology Project data product based on analyses of channel 1 and 2 AVHRR radiances shows significant regional changes in the retrieved optical thickness of tropospheric aerosols which had occurred between the volcano-free periods 1988-91 and 2002-05. These trends appear to be generally plausible, are consistent with extensive sets of long-term ground-based observations throughout the world, and may increase the trustworthiness of the recently identified downward trend in the global tropospheric aerosol load. (c) 2007 Optical Society of America. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, New York, NY 10025 USA. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM mmishchenko@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 NR 55 TC 60 Z9 62 U1 2 U2 9 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 11 PY 2007 VL 15 IS 12 BP 7423 EP 7438 DI 10.1364/OE.15.007423 PG 16 WC Optics SC Optics GA 194QU UT WOS:000248359700040 PM 19547066 ER PT J AU Mishchenko, MI Liu, L Videen, G AF Mishchenko, Michael I. Liu, Li Videen, Gorden TI Conditions of applicability of the single-scattering approximation SO OPTICS EXPRESS LA English DT Article ID LIGHT-SCATTERING; PARTICLES; MATRICES; POLARIZATION AB We employ the numerically exact superposition T-matrix method to perform extensive computations of electromagnetic scattering by small volume elements filled with 8 randomly distributed wavelength-sized spherical particles. The results of these computations are used to examine quantitatively the conditions of applicability of the single-scattering approximation (SSA). We show that one may need large inter-particle distances and low packing densities in order to make the SSA sufficiently accurate. (C) 2007 Optical Society of America. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. AMSRD ARL CI EM, US Army Res Lab, Adelphi, MD 20783 USA. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM mmishchenko@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 NR 16 TC 18 Z9 19 U1 0 U2 3 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 11 PY 2007 VL 15 IS 12 BP 7522 EP 7527 DI 10.1364/OE.15.007522 PG 6 WC Optics SC Optics GA 194QU UT WOS:000248359700050 PM 19547076 ER PT J AU Bringa, EM Kucheyev, SO Loeffler, MJ Baragiola, RA Tielens, AGGM Dai, ZR Graham, G Bajt, S Bradley, JP Dukes, CA Felter, TE Torres, DF van Breugel, W AF Bringa, E. M. Kucheyev, S. O. Loeffler, M. J. Baragiola, R. A. Tielens, A. G. G. M. Dai, Z. R. Graham, G. Bajt, S. Bradley, J. P. Dukes, C. A. Felter, T. E. Torres, D. F. van Breugel, W. TI Energetic processing of interstellar silicate grains by cosmic rays SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic rays; dust; extinction ID INTERPLANETARY DUST PARTICLES; CRYSTALLINE SILICATE; EVOLVED STARS; INFRARED GALAXIES; SPACE-TELESCOPE; ION IRRADIATION; TRACK FORMATION; SPECTRA; DISKS; RECOMBINATION AB While a significant fraction of silicate dust in stellar winds has a crystalline structure, in the interstellar medium nearly all of it is amorphous. One possible explanation for this observation is the amorphization of crystalline silicates by relatively " low'' energy, heavy- ion cosmic rays. Here we present the results of multiple laboratory experiments showing that single- crystal synthetic forsterite (Mg2SiO4) amorphizes when irradiated by 10 MeV Xe ions at large enough fluences. Using modeling, we extrapolate these results to show that 0.1-5.0 GeV heavy-ion cosmic rays can rapidly (similar to 70 Myr) amorphize crystalline silicate grains ejected by stars into the interstellar medium. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Virginia, Lab Atom & Surface Phys, Charlottesville, VA 22903 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. ICREA, Inst Ciencies Espai, ES-08193 Barcelona, Spain. EM ebringa@llnl.gov RI Dai, Zurong/E-6732-2010; Bajt, Sasa/G-2228-2010; Bringa, Eduardo/F-8918-2011; Loeffler, Mark/C-9477-2012; Torres, Diego/O-9422-2016 OI Torres, Diego/0000-0002-1522-9065 NR 63 TC 45 Z9 45 U1 1 U2 11 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 10 PY 2007 VL 662 IS 1 BP 372 EP 378 DI 10.1086/517865 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176HB UT WOS:000247074400029 ER PT J AU Grupe, D Gronwall, C Wang, XY Roming, PWA Cummings, J Zhang, B Meszaros, P Trigo, MD O'Brien, PT Page, KL Beardmore, A Godet, O Berk, DE Brown, PJ Koch, S Morris, D Stroh, M Burrows, DN Nousek, JA Chester, MM Immler, S Mangano, V Romano, P Chincarini, G Osborne, J Sakamoto, T Gehrels, N AF Grupe, Dirk Gronwall, Caryl Wang, Xiang-Yu Roming, Peter W. A. Cummings, Jay Zhang, Bing Meszaros, Peter Trigo, Maria Diaz O'Brien, Paul T. Page, Kim L. Beardmore, Andy Godet, Olivier vanden Berk, Daniel E. Brown, Peter J. Koch, Scott Morris, David Stroh, Michael Burrows, David N. Nousek, John A. Chester, Margaret McMath Immler, Stefan Mangano, Vanessa Romano, Patrizia Chincarini, Guido Osborne, Julian Sakamoto, Takanori Gehrels, Neil TI Swift and XMM-Newton observations of the extraordinary gamma-ray burst 060729: More than 125 days of x-ray afterglow SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; X-rays : bursts ID BURST AFTERGLOWS; LIGHT CURVES; MICROMETEOROID DAMAGE; MILLISECOND PULSARS; ENERGY INJECTION; ENGINE ACTIVITY; H-I; FLARES; TELESCOPE; EVOLUTION AB We report the results of the Swift and XMM-Newton observations of the Swift-discovered GRB 060729 (T-90 = 115 s). The afterglow of this burst was exceptionally bright in X-rays as well as at UV/optical wavelengths, showing an unusually long slow decay phase (alpha = 0.14 +/- 0.02), suggesting a larger energy injection phase at early times than in other bursts. The X-ray light curve displays a break at about 60 ks after the burst. The X-ray decay slope after the break is alpha = 1.29 +/- 0.03. Up to 125 days after the burst we do not detect a jet break, suggesting that the jet opening angle is larger than 28 degrees. We find that the X-ray spectra of the early phase change dramatically and can all be fitted by an absorbed single-power-law models or alternatively by a blackbody plus power-law model. The power-law fits show that the X-ray spectrum becomes steeper while the absorption column density decreases. In the blackbody model the temperature decreases from kT = 0.6 to 0.1 keV between 85 and 160 s after the burst in the rest frame. The afterglow was clearly detected up to 9 days after the burst in all six UVOT filters and in UVW1 even for 31 days. A break at about 50 ks is clearly detected in all six UVOT filters from a shallow decay slope of about 0.3 and a steeper decay slope of 1.3. The XMM-Newton observations started about 12 hr after the burst and show a typical afterglow X-ray spectrum with beta(X) = 1.1 and absorption column density of 1 X 10(21) cm(-2). C1 Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Nanjing Univ, Dept Astron, Nanjing 210093, Peoples R China. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Astroparticle Phys Lab, Greenbelt, MD 20771 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. XMM Newton Sci Operat Ctr, European Space Agcy, E-28080 Madrid, Spain. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. NASA, Goddard Space Flight Ctr, Astrophys Sci Div, X Ray Astrophys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. INAF, Ist Astrofis Spaziale Fis Cosmica, I-90146 Palermo, Italy. INAF, Osservatorio Astron Brera, I-23807 Merate, Italy. EM grupe@astro.psu.edu RI Gehrels, Neil/D-2971-2012 NR 71 TC 90 Z9 90 U1 1 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2007 VL 662 IS 1 BP 443 EP 458 DI 10.1086/517868 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176HB UT WOS:000247074400035 ER PT J AU von Hippel, T Kuchner, MJ Kilic, M Mullally, F Reach, WT AF von Hippel, Ted Kuchner, Marc J. Kilic, Mukremin Mullally, Fergal Reach, William T. TI The new class of dusty DAZ white dwarfs SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion; accretion disks; circumstellar matter; white dwarfs ID EXCESS INFRARED RADIATION; BROWN DWARF; METAL ABUNDANCE; DEBRIS DISK; G29-38; COOL; ACCRETION; COMPANIONS; STARS; RICH AB Our mid-infrared survey of 124 white dwarfs with the Spitzer Space Telescope and the IRAC imager has revealed an infrared excess associated with the white dwarf WD 2115-560 naturally explained by circumstellar dust. This object is the fourth white dwarf observed to have circumstellar dust. All four are DAZ white dwarfs, i. e., they have both photospheric Balmer lines and photospheric metal lines. We discuss these four objects as a class, which we abbreviate "DAZd,'' where the "d'' stands for "dust.'' Using an optically thick, geometrically thin disk model analogous to Saturn's rings, we find that the inner disk edges are at greater than or similar to 0.1-0.2 R-circle dot and that the outer disk edges are similar to 0.3-0.6 R-circle dot. This model naturally explains the accretion rates and lifetimes of the detected WD disks and the accretion rates inferred from photospheric metal abundances. C1 Univ Texas, Dept Astron, Austin, TX 78712 USA. SW Res Inst, Boulder, CO USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. EM ted@astro.as.utexas.edu RI Reach, William/C-4710-2008; Kuchner, Marc/E-2288-2012; OI Reach, William/0000-0001-8362-4094 NR 54 TC 96 Z9 96 U1 1 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2007 VL 662 IS 1 BP 544 EP 551 DI 10.1086/518108 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176HB UT WOS:000247074400043 ER PT J AU Verdini, A Velli, M AF Verdini, Andrea Velli, Marco TI Alfven waves and turbulence in the solar atmosphere and solar wind SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; solar wind; turbulence; waves ID LOW-FREQUENCY WAVES; STELLAR ATMOSPHERES; MAGNETIC-FIELD; CROSS HELICITY; CORONAL HOLES; WHITE-LIGHT; FLUX TUBES; POLAR WIND; FLUCTUATIONS; DRIVEN AB We solve the problem of propagation and dissipation of Alfvenic turbulence in a model solar atmosphere consisting of a static photosphere and chromosphere, transition region, and open corona and solar wind using a phenomenological model for the turbulent dissipation based on wave reflection. We show that most of the dissipation for a given wave-frequency spectrum occurs in the lower corona, and the overall rms amplitude of the fluctuations evolves in a way consistent with observations. The frequency spectrum for a Kolmogorov-like slope is not found to change dramatically from the photosphere to the solar wind; however, it does preserve signatures of transmission throughout the lower atmospheric layers, namely, oscillations in the spectrum at high frequencies reminiscent of the resonances found in the linear case. These may disappear once more realistic couplings for the nonlinear terms are introduced or if time-dependent variability of the lower atmospheric layer is introduced. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. NR 48 TC 104 Z9 104 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2007 VL 662 IS 1 BP 669 EP 676 DI 10.1086/510710 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176HB UT WOS:000247074400055 ER PT J AU McAteer, RTJ Young, CA Ireland, J Gallagher, PT AF McAteer, R. T. James Young, C. Alex Ireland, Jack Gallagher, Peter T. TI The bursty nature of solar flare X-ray emission SO ASTROPHYSICAL JOURNAL LA English DT Article DE methods : statistical; Sun : activity; Sun : flares ID MULTIFRACTAL FORMALISM; WAVELET ANALYSIS; OBSERVATIONAL EVIDENCE; PARTICLE-ACCELERATION; STATISTICAL FLARE; ACTIVE REGIONS; PHASE; OSCILLATIONS; TURBULENCE; FREQUENCY AB The complex and highly varying temporal nature of emission from an X4.8 flare is studied across seven X-ray energy bands. A wavelet transform modulus maxima method is used to obtain the multifractal spectra of the temporal variation of the X-ray emission. As expected from the Neupert effect, the time series of the emission at low energies (3-6, 6-12 keV; thermal) is smooth. The peak Holder exponent, around 1.2, for this low-energy emission is indicative of a signal with a high degree of memory and suggestive of a smooth chromospheric evaporation process. The more bursty emission at higher energies (100-300, 300-800 keV; nonthermal) is described by a multifractal spectrum that peaks at a smaller Holder exponent (less than 0.5 for the largest singularities), indicative of a signal with a low degree of memory. This describes an antipersistent walk and indicates an impulsive, incoherent driving source. We suggest that this may arise from bursty reconnection, with each reconnection event producing a different and uncorrelated nonthermal particle source. The existence of a power-law scaling of wavelet coefficients across time-scales is in agreement with the creation of a fractal current sheet diffusion region. C1 Catholic Univ Amer, Inst Astron & Computat Sci, Solar Phys Grp, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Solar Phys Branch, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Adnet Syst Inc, Greenbelt, MD 20771 USA. Trinity Coll Dublin, Sch Phys, Astrophys Res Grp, Dublin 2, Ireland. EM j.mcateer@grasshopper.gsfc.nasa.gov RI McAteer, R. T. James/D-3736-2011; Gallagher, Peter/C-7717-2011 OI Gallagher, Peter/0000-0001-9745-0400 NR 54 TC 32 Z9 32 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 JUN 10 PY 2007 VL 662 IS 1 BP 691 EP 700 DI 10.1086/518086 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176HB UT WOS:000247074400057 ER PT J AU Buchlin, E Velli, M AF Buchlin, E. Velli, M. TI Shell models of rMHD turbulence and the heating of solar coronal loops SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : corona; Sun : flares; turbulence ID MEAN MAGNETIC-FIELD; AUTOMATA CA MODELS; MAGNETOHYDRODYNAMIC TURBULENCE; MHD TURBULENCE; ACTIVE REGIONS; ALFVEN WAVES; REDUCED MAGNETOHYDRODYNAMICS; SCALING LAWS; QUIET SUN; FLUCTUATIONS AB A simplified nonlinear numerical model for the development of incompressible magnetohydrodynamics in the presence of a strong magnetic field B-parallel to and stratification, nicknamed "Shell- Atm,'' is presented. In planes orthogonal to the mean field, the nonlinear incompressible dynamics is replaced by two-dimensional shell models for the complex variables u and b, allowing one to reach large Reynolds numbers while at the same time carrying out sufficiently long integrations to obtain good statistics at moderate computational cost. The shell models of different planes are coupled by Alfven waves propagating along B-parallel to. The model may be applied to open or closed magnetic field configurations where the axial field dominates and the plasma pressure is low; here we apply it to the specific case of a magnetic loop of the solar corona heated by means of turbulence driven by photospheric motions, and we use statistics for its analysis. The Alfven waves interact nonlinearly and form turbulent spectra in the directions perpendicular and, through propagation, also parallel to the mean field. A heating function is obtained and shown to be intermittent; the average heating is consistent with values required for sustaining a hot corona and is proportional to the aspect ratio of the loop to the -1.5 power, and characteristic properties of heating events are distributed as power laws. Cross-correlations show a delay of dissipation compared with energy content. C1 Univ Florence, Dipartimento Astron & Sci Spazio, I-50125 Florence, Italy. Univ London Imperial Coll Sci & Technol, Blackett Lab, Space & Atmospher Phys Grp, London SW7 2BW, England. CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. OI Buchlin, Eric/0000-0003-4290-1897 NR 50 TC 40 Z9 40 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 10 PY 2007 VL 662 IS 1 BP 701 EP 714 DI 10.1086/512765 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176HB UT WOS:000247074400058 ER PT J AU Lattanzi, V Walters, A Drouin, BJ Pearson, JC AF Lattanzi, Valerio Walters, Adam Drouin, Brian J. Pearson, John C. TI Rotational spectrum of the formyl cation, HCO+, to 1.2 THz SO ASTROPHYSICAL JOURNAL LA English DT Article DE catalogs; ISM : molecules; methods : laboratory; molecular data; solar system : formation ID INFRARED-LASER SPECTROSCOPY; NU-3 FUNDAMENTAL-BAND; MOLECULAR-SPECTROSCOPY; MILLIMETER; EMISSION; HCN; DCO+; ION; FREQUENCY; LINE AB A variety of high-quality spectroscopic studies have contributed to knowledge of the formyl cation, HCO+, and its rare isotopologues, but technical limitations have previously limited precise determinations of the far-infrared, or terahertz spectrum. This study extends the microwave, millimeter, and submillimeter spectroscopy of HCO+ into the terahertz range. The resulting measurements and predictions are of sufficient coverage to adequately address astrophysical questions about this species using the Herschel Space Observatory or the Atacama Large Millimeter Array. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Lattanzi, V (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. EM adam.walters@cesr.fr NR 43 TC 24 Z9 24 U1 0 U2 11 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 2007 VL 662 IS 1 BP 771 EP 778 DI 10.1086/517602 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176HB UT WOS:000247074400065 ER PT J AU Hicks, MD Bauer, JM AF Hicks, Michael D. Bauer, James M. TI P/2006 HR30 (siding spring): A low-activity comet in near-earth space SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; comets : individual (P/2006 HR30); Kuiper Belt; minor planets, asteroids; solar system : formation ID NARROW-BAND PHOTOMETRY; TELESCOPE; BEHAVIOR; NUCLEUS AB The low cometary activity of P/2006 HR30 (Siding Spring) allowed a unique opportunity to study the nucleus of a periodic comet while near perihelion. P/2006 HR30 was originally targeted as a potential extinct comet, and we measured spectral reflectance and dust production using long-slit CCD spectroscopy and wide-field imaging obtained at the Palomar Mountain 200 inch telescope on 2006 August 3 and 4. The dust production Af rho = 19.7 +/- 19.7 +/- 0.4 cm and mass-loss rate Q(dust = 4.1 +/- 0.1) kg s(-1) of the comet were approximately 2 orders of magnitude 19.7 +/- 0.4 Q p 4.1 +/- 0.1 dust less than 1P/Halley at similar heliocentric distance. The VRI colors derived from the spectral reflectance were compared to Kuiper Belt objects, Centaurs, and other cometary nuclei. We found that the spectrum of P/2006 HR30 was consistent with other comets. However, the outer solar system bodies have a color distribution statistically distinct from cometary nuclei. It is our conjecture that cometary activity, most likely the reaccretion of ejected cometary dust, tends to moderate and mute the visible colors of the surface of cometary nuclei. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 30 TC 5 Z9 5 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2007 VL 662 IS 1 BP L47 EP L50 DI 10.1086/519021 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 176HC UT WOS:000247074500012 ER PT J AU Hansell, RA Ou, SC Liou, KN Roskovensky, JK Tsay, SC Hsu, C Ji, Q AF Hansell, R. A. Ou, S. C. Liou, K. N. Roskovensky, J. K. Tsay, S. C. Hsu, C. Ji, Q. TI Simultaneous detection/separation of mineral dust and cirrus clouds using MODIS thermal infrared window data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AFRICAN DUST; ART.; REGIONS; STORMS AB An integrated method for the simultaneous detection/separation of mineral dust and clouds for both daytime and nighttime conditions using MODIS thermal infrared window brightness temperature data has been developed. Based on the spectral variability of dust emissivity at 3.75, 8.6, 11 and 12 mu m wavelengths, we combine three heritage approaches to identify dust and cirrus. MODIS data for three dust-laden scenes have been analyzed to demonstrate the effectiveness of this detection/separation method. The detected daytime dust and cloud coverage for the Persian Gulf case compares reasonably well to those from the "Deep Blue'' algorithm developed at NASA-GSFC. Validation of the nighttime dust and cloud detection method has been carried out by using the cases surrounding Cape Verde and Niger, West Africa, on the basis of the coincident and collocated ground-based micro-pulse lidar measurements. C1 Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hansell, RA (reprint author), Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. EM rhansell@atmos.ucla.edu RI Hsu, N. Christina/H-3420-2013; Tsay, Si-Chee/J-1147-2014; Hansell, Richard/J-2065-2014 NR 13 TC 27 Z9 27 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 JUN 9 PY 2007 VL 34 IS 11 AR L11808 DI 10.1029/2007GL029388 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 177FZ UT WOS:000247140300003 ER PT J AU Clarke, A McNaughton, C Kapustin, V Shinozuka, Y Howell, S Dibb, J Zhou, J Anderson, B Brekhovskikh, V Turner, H Pinkerton, M AF Clarke, A. McNaughton, C. Kapustin, V. Shinozuka, Y. Howell, S. Dibb, J. Zhou, J. Anderson, B. Brekhovskikh, V. Turner, H. Pinkerton, M. TI Biomass burning and pollution aerosol over North America: Organic components and their influence on spectral optical properties and humidification response SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PRIMARY PARTICLE EMISSIONS; LIGHT-ABSORPTION; INTEGRATING NEPHELOMETER; CARBONACEOUS PARTICLES; CHEMICAL-COMPOSITION; SIZE DISTRIBUTIONS; RELATIVE-HUMIDITY; DEPENDENCE; SCATTERING; CALIBRATION AB Thermal analysis of aerosol size distributions provided size resolved volatility up to temperatures of 400 degrees C during extensive flights over North America (NA) for the INTEX/ICARTT experiment in summer 2004. Biomass burning and pollution plumes identified from trace gas measurements were evaluated for their aerosol physiochemical and optical signatures. Measurements of soluble ionic mass and refractory black carbon ( BC) mass, inferred from light absorption, were combined with volatility to identify organic carbon at 400 degrees C (VolatileOC) and the residual or refractory organic carbon, RefractoryOC. This approach characterized distinct constituent mass fractions present in biomass burning and pollution plumes every 5-10 min. Biomass burning, pollution and dust aerosol could be stratified by their combined spectral scattering and absorption properties. The "nonplume'' regional aerosol exhibited properties dominated by pollution characteristics near the surface and biomass burning aloft. VolatileOC included most water-soluble organic carbon. RefractoryOC dominated enhanced shortwave absorption in plumes from Alaskan and Canadian forest fires. The mass absorption efficiency of this RefractoryOC was about 0.63 m(2) g(-1) at 470 nm and 0.09 m(2) g(-1) at 530 nm. Concurrent measurements of the humidity dependence of scattering, gamma, revealed the OC component to be only weakly hygroscopic resulting in a general decrease in gamma with increasing OC mass fractions. Under ambient humidity conditions, the systematic relations between physiochemical properties and gamma lead to a well-constrained dependency on the absorption per unit dry mass for these plume types that may be used to challenge remotely sensed and modeled optical properties. C1 Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Univ Alabama, Dept Chem Engn, Tuscaloosa, AL 35487 USA. RP Clarke, A (reprint author), Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. EM tclarke@soest.hawaii.edu; jack.dibb@unh.edu; b.e.anderson@larc.nasa.gov; hturner@eng.ua.edu NR 47 TC 95 Z9 97 U1 0 U2 38 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 9 PY 2007 VL 112 IS D12 AR D12S18 DI 10.1029/2006JD007777 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177GM UT WOS:000247141600002 ER PT J AU Jensen, EJ Ackerman, AS Smith, JA AF Jensen, E. J. Ackerman, A. S. Smith, J. A. TI Can overshooting convection dehydrate the tropical tropopause layer? SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-VAPOR; AIRCRAFT DATA; TRANSPORT; MODEL; MONSOON; DEEP; SIZE; AIR AB [1] A numerical model is used to investigate the potential for irreversible dehydration near the tropical tropopause caused by overshooting deep convection. We show that convective updrafts overshooting the cold point tropopause can generate extremely cold, dry air within the updrafts. However, the updrafts contain sufficient mass in small (<= 20 mu m radius) ice crystals that do not sediment out of the short-lived overshoots, such that when the overshoots collapse and warm back to the ambient temperature, these small crystals sublimate and rehydrate the air, resulting in no irreversible dehydration. Despite maximizing crystal size (and fall speed) by assuming low aerosol concentrations and using large ice-ice collection efficiencies, we find no evidence to support the hypothesis that overshooting convection can dehydrate the tropical tropopause layer (TTL) when it is initially ice subsaturated. Only when the TTL is initially supersaturated with respect to ice do we find that deep convection can draw down the humidity, as vapor in excess of saturation condenses on the ice crystals. The overall impact of deep convection on the TTL water vapor budget depends on the climatology of TTL relative humidity in convective regions. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. RP Jensen, EJ (reprint author), NASA, Ames Res Ctr, MS 245-4, Moffett Field, CA 94035 USA. EM eric.j.jensen@nasa.gov; andrew.ackerman@nasa.gov; jamisons@lasp.colorado.edu RI Ackerman, Andrew/D-4433-2012 OI Ackerman, Andrew/0000-0003-0254-6253 NR 34 TC 47 Z9 47 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 9 PY 2007 VL 112 IS D11 AR D11209 DI 10.1029/2006JD007943 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177GI UT WOS:000247141200004 ER PT J AU Mena-Carrasco, M Tang, Y Carmichael, GR Chai, T Thongbongchoo, N Campbell, JE Kulkarni, S Horowitz, L Vukovich, J Avery, M Brune, W Dibb, JE Emmons, L Flocke, F Sachse, GW Tan, D Shetter, R Talbot, RW Streets, DG Frost, G Blake, D AF Mena-Carrasco, Marcelo Tang, Youhua Carmichael, Gregory R. Chai, Tianfeng Thongbongchoo, Narisara Campbell, J. Elliott Kulkarni, Sarika Horowitz, Larry Vukovich, Jeffrey Avery, Melody Brune, William Dibb, Jack E. Emmons, Louisa Flocke, Frank Sachse, Glen W. Tan, David Shetter, Rick Talbot, Robert W. Streets, David G. Frost, Gregory Blake, Donald TI Improving regional ozone modeling through systematic evaluation of errors using the aircraft observations during the International Consortium for Atmospheric Research on Transport and Transformation SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GAS-AEROSOL EQUILIBRIUM; TRACE-P; PARIS AREA; ART.; AIR; POLLUTION AB During the operational phase of the ICARTT field experiment in 2004, the regional air quality model STEM showed a strong positive surface bias and a negative upper troposphere bias (compared to observed DC-8 and WP-3 observations) with respect to ozone. After updating emissions from NEI 1999 to NEI 2001 (with a 2004 large point sources inventory update), and modifying boundary conditions, low-level model bias decreases from 11.21 to 1.45 ppbv for the NASA DC-8 observations and from 8.26 to -0.34 for the NOAA WP-3. Improvements in boundary conditions provided by global models decrease the upper troposphere negative ozone bias, while accounting for biomass burning emissions improved model performance for CO. The covariances of ozone bias were highly correlated to NOz, NOy, and HNO3 biases. Interpolation of bias information through kriging showed that decreasing emissions in SE United States would reduce regional ozone model bias and improve model correlation coefficients. The spatial distribution of forecast errors was analyzed using kriging, which identified distinct features, which when compared to errors in postanalysis simulations, helped document improvements. Changes in dry deposition to crops were shown to reduce substantially high bias in the forecasts in the Midwest, while updated emissions were shown to account for decreases in bias in the eastern United States. Observed and modeled ozone production efficiencies for the DC-8 were calculated and shown to be very similar (7.8) suggesting that recurring ozone bias is due to overestimation of NOx emissions. Sensitivity studies showed that ozone formation in the United States is most sensitive to NOx emissions, followed by VOCs and CO. PAN as a reservoir of NOx can contribute to a significant amount of surface ozone through thermal decomposition. C1 Univ Iowa, Ctr Global & Reg Environm Res, Iowa City, IA 52242 USA. Penn State Univ, Dept Earth Sci, University Pk, PA 16802 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80305 USA. NOAA, Div Chem Sci, Earth Syst Res Lab, Boulder, CO 80305 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08540 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. King Mongkuts Inst Technol, Dept Chem Engn, Fac Engn, Bangkok 10520, Thailand. Univ N Carolina, Inst Environm, Chapel Hill, NC 27599 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RP Mena-Carrasco, M (reprint author), Univ Iowa, Ctr Global & Reg Environm Res, Iowa City, IA 52242 USA. RI Mena-Carrasco, Marcelo/L-9730-2016; Emmons, Louisa/R-8922-2016; Manager, CSD Publications/B-2789-2015; Campbell, Elliott/B-8025-2008; Chai, Tianfeng/E-5577-2010; Frost, Gregory/I-1958-2013; Mena-Carrasco, Marcelo/B-8483-2012; Horowitz, Larry/D-8048-2014; Tang, Youhua/D-5205-2016; OI Emmons, Louisa/0000-0003-2325-6212; Chai, Tianfeng/0000-0003-3520-2641; Horowitz, Larry/0000-0002-5886-3314; Tang, Youhua/0000-0001-7089-7915; Streets, David/0000-0002-0223-1350 NR 40 TC 8 Z9 8 U1 0 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 9 PY 2007 VL 112 IS D12 AR D12S19 DI 10.1029/2006JD007762 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177GM UT WOS:000247141600001 ER PT J AU Warner, J Comer, MM Barnet, CD McMillan, WW Wolf, W Maddy, E AF Warner, Juying Comer, M. McCourt Barnet, C. D. McMillan, W. W. Wolf, W. Maddy, E. TI A comparison of satellite tropospheric carbon monoxide measurements from AIRS and MOPITT during INTEX-A SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EMISSION SPECTROMETER; OCTOBER 1994; CO; OZONE; RETRIEVAL; POLLUTION; TES; AIRS/AMSU/HSB; INSTRUMENT; OBJECTIVES AB Satellite CO measurements from Measurements of Pollution in the Troposphere (MOPITT) and Atmospheric Infrared Sounder (AIRS) were used in the Intercontinental Chemical Transport Experiment-North America (INTEX-A) by the flight planning team to monitor local emissions and the transport of polluted air masses. Because simultaneous measurements of tropospheric CO from both AIRS and MOPITT were used by different investigators during this experiment, a cross reference and comparison are necessary to understand these two data sets and their impacts to the scientific conclusions developed from them. The global CO mixing ratios at 500 mbar, as well as the CO total column amount, are compared between the two instruments for both direct comparison and the comparison using the same a priori profile for the period from 15 June to 14 August 2004. Also presented are the comparisons of the remotely sensed profiles by AIRS, MOPITT, and the in situ profiles collected by the DACOM. In summary, both sensors agree very well on the horizontal distributions of CO represented by the high correlation coefficients (0.7-0.98), and they agree on the CO concentrations to within an average of 10-15 ppbv. Over land, the CO variability is higher, and the correlations between the two data sets are relatively lower than over ocean; however, there is no evidence of a systematic bias. Over the oceans where the CO concentration is smaller in the lower atmosphere, AIRS-MOPITT show a positive bias of 15-20 ppbv and the details are presented. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. NOAA, Ctr Satellite Applicat & Res, Camp Springs, MD 20746 USA. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. QSS Grp Inc, Lanham, MD 20706 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Warner, J (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, 5523 Res Pk, Baltimore, MD 21250 USA. EM juying@umbc.edu RI Maddy, Eric/G-3683-2010; Barnet, Christopher/F-5573-2010; Wolf, Walter/E-7935-2011 OI Maddy, Eric/0000-0003-1151-339X; Wolf, Walter/0000-0002-2102-8833 NR 32 TC 49 Z9 49 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 9 PY 2007 VL 112 IS D12 AR D12S17 DI 10.1029/2006JD007925 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177GM UT WOS:000247141600003 ER PT J AU Takahashi, H Wrasse, CM Fechine, J Pancheva, D Abdu, MA Batista, IS Lima, LM Batista, PP Clemesha, BR Schuch, NJ Shiokawa, K Gobbi, D Mlynczak, MG Russell, JM AF Takahashi, H. Wrasse, C. M. Fechine, J. Pancheva, D. Abdu, M. A. Batista, I. S. Lima, L. M. Batista, P. P. Clemesha, B. R. Schuch, N. J. Shiokawa, K. Gobbi, D. Mlynczak, M. G. Russell, J. M. TI Signatures of ultra fast Kelvin waves in the equatorial middle atmosphere and ionosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PLANETARY-WAVES; THERMOSPHERE; MESOSPHERE AB In the equatorial atmosphere, oscillations with periods of 3 to 4 days have been observed in the meteor radar zonal wind at Cariri ( 7.4 degrees S, 36.5 degrees W), in the ionospheric minimum virtual height h'F and the maximum critical frequency foF2 at Fortaleza (3.9 degrees S, 38.4 degrees W), and in the TIMED/SABER satellite temperature data in the stratosphere-mesosphere. Wavelet analyses of these time series reveal that the 3-4-day oscillation was observed for all of these data during the period from March 1 to 11, 2005. From the characteristics of the downward phase propagation ( wavelength of similar to 40 km), longitudinal and latitudinal extension, we conclude that this oscillation must be a 3.5-day Ultra Fast Kelvin (UFK) wave. This is the first report of clear evidence of propagation of a UFK wave from the stratosphere to the ionosphere. The UFK wave could have an important role in the day-to-day variability of the equatorial ionosphere evening uplift. C1 INPE, Div Aeron, BR-12201970 Sao Jose Dos Campos, Brazil. Univ Vale Paraiba, Inst Pesquisa & Desenvolvimento, BR-12244000 Sao Jose Dos Campos, Brazil. Univ Bath, Dept Elect & Elect Engn, Bath BA2 7AY, Avon, England. Univ Estadual Paraiba, Dept Fis, BR-58109790 Campina Grande, PB, Brazil. Inst Nacl Pesquisas Espaciais, Ctr Reg Sul Pesquisas Espaciais, BR-97110970 Santa Maria, RS, Brazil. Nagoya Univ, Solar Terr Environm Lab, Toyokawa, Japan. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23665 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Takahashi, H (reprint author), INPE, Div Aeron, CP 515, BR-12201970 Sao Jose Dos Campos, Brazil. EM hisaotak@laser.inpe.br RI Batista, Paulo/C-2616-2009; Batista, Inez/F-2899-2012; Mlynczak, Martin/K-3396-2012; Takahashi, Hisao/C-5299-2013; Wrasse, Cristiano/N-6556-2013; Schuch, Nelson/K-9730-2015 OI Batista, Paulo/0000-0002-5448-5803; Schuch, Nelson/0000-0002-7720-6491 NR 16 TC 39 Z9 39 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 8 PY 2007 VL 34 IS 11 AR L11108 DI 10.1029/2007GL029612 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 177FX UT WOS:000247140100004 ER PT J AU Courville, ZR Albert, MR Fahnestock, MA Cathles, LM Shuman, CA AF Courville, Z. R. Albert, M. R. Fahnestock, M. A. Cathles, L. M. Shuman, C. A. TI Impacts of an accumulation hiatus on the physical properties of firn at a low-accumulation polar site SO JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE LA English DT Article ID EAST ANTARCTIC PLATEAU; SNOW ACCUMULATION; TEMPORAL VARIABILITY; ICE-SHEET; GREENLAND; SURFACE; METAMORPHISM; PARAMETERS; VICINITY; STATION AB Recent field investigations of a megadune region of East Antarctica provide evidence that differences in grain size, thermal conductivity, and permeability across a megadune profile are due to spatial accumulation variability in the absence of significant microclimate variations. The megadunes are low-amplitude (2-8 m), long-wavelength (2-5 km) bands with perceptible but low accumulation ( less than 40 mm water equivalent (weq) yr(-1)) and accumulation hiatus within several kilometers proximity, as determined by remote sensing, surface feature classification, and ground-penetrating radar profiling. Our hypothesis that accumulation rate impacts the extent of temperature gradient-driven metamorphic growth in low accumulation rate sites is supported by measurements of various firn physical properties. Relatively small differences in accumulation rate (less than 40 mm weq yr(-1)) result in large differences in physical properties, including grain size, thermal conductivity, and permeability, which are apparent in satellite-based microwave data from both passive and active sensors. The differences in physical snow structure between low-accumulation areas and accumulation hiatus areas in the near surface are sufficiently distinct that evidence of past accumulation hiatus should be observable in the physical and chemical properties of an ice core record. C1 USA, Cold Reg Res & Engn Lab, Cyrospher & Terr Sci Div, Hanover, NH 03755 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Cryospher Sci Branch, Greenbelt, MD 20771 USA. Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA. RP Courville, ZR (reprint author), USA, Cold Reg Res & Engn Lab, Cyrospher & Terr Sci Div, 72 Lyme Rd, Hanover, NH 03755 USA. EM zoe.courville@dartmouth.edu RI Fahnestock, Mark/N-2678-2013; OI Albert, Mary/0000-0001-7842-2359 NR 42 TC 34 Z9 34 U1 1 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-EARTH JI J. Geophys. Res.-Earth Surf. PD JUN 8 PY 2007 VL 112 IS F2 AR F02030 DI 10.1029/2005JF000429 PG 11 WC Geosciences, Multidisciplinary SC Geology GA 177GO UT WOS:000247141800001 ER PT J AU Bills, BG Adams, KD Wesnousky, SG AF Bills, Bruce G. Adams, Kenneth D. Wesnousky, Steven G. TI Viscosity structure of the crust and upper mantle in western Nevada from isostatic rebound patterns of the late Pleistocene Lake Lahontan high shoreline SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review ID STATES UPPER-MANTLE; HOT-SPRINGS TEPHRA; GREAT-BASIN; RANGE PROVINCE; CARBONATE DEPOSITION; BOLIVIAN ALTIPLANO; GORGES RESERVOIR; RADIOCARBON AGES; CENTRAL MONGOLIA; NORTHERN BASIN AB [1] Large lakes can both produce and record significant crustal deformation. We present an analysis of the isostatic rebound pattern recorded in the shorelines of paleolake Lahontan, in western Nevada, using a layered Maxwell viscoelastic model. The inferred viscosity structure depends on loading history. We use three variants of a well-documented lake surface elevation model as input and recover corresponding estimates of viscosity and density structure. A simple two-layer model, with an elastic plate over an inviscid half-space, fits the observed elevation pattern quite well, with a residual variance of 32% of the data variance. Using multilayered, finite viscosity models, the residual variance is reduced to 20% of the data variance, which is very near to the noise level. In the higher-resolution models, the viscosity is below 10(18) Pa s over the depth range from 80 to 160 km. The minimum viscosity is very similar to the value that has been seen in the eastern Great Basin, from similar analyses of Lake Bonneville shorelines, but the low-viscosity zone is thinner beneath Bonneville. Making small adjustments to a seismically derived density structure allows an improved fit to the shoreline observations. Additionally, we find that small variations in proposed loading models can result in presumably spurious density inversions, and suggest that this modeling approach provides a test for loading histories. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. Univ Nevada, Ctr Neotecton Studies, Reno, NV 89557 USA. RP Bills, BG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM bbills@ucsd.edu RI Bills, Bruce/C-1156-2008 NR 107 TC 28 Z9 28 U1 2 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 8 PY 2007 VL 112 IS B6 AR B06405 DI 10.1029/2005JB003941 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 177GX UT WOS:000247142700001 ER PT J AU Narock, TW Lepping, RP AF Narock, T. W. Lepping, R. P. TI Anisotropy of magnetic field fluctuations in an average interplanetary magnetic cloud at 1 AU SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; SOLAR-WIND; ORIGIN AB A subset of magnetic clouds (MCs) identified over 8.6 years of the WIND mission are examined for a pattern of anisotropic magnetic field fluctuations within their extent at 1 AU. This subset (N=42) consists of MCs taken from a comprehensive survey of WIND Magnetic Field Investigation data. Root mean square deviations of the axial field ( RMSA) and the perpendicular field (RMS(perpendicular to); i.e., that lying in the cross-sectional plane of the MC), rendered in a magnetic cloud coordinate system, are computed on three timescales, 8, 30, and 60 min, and a fluctuation anisotropy quantity [A(t)=< RMS(A)>/< RMS(perpendicular to)>-1] is calculated for each timescale. The 42 MCs are separated by relative closest approach (Y(0)/R(0)) into two distinct regions [vertical bar Y(0)/R(0)vertical bar<0.33 (inner) and 0.33 0.25 and alpha-Angstrom < 0.8; mostly due to desert dust events), the bias increases to 15.1 +/- 0.6%. This is due to the fact that absorbing aerosols in the boundary layer are currently not adequately modeled in the operational TOMS UV algorithm. TOMS data can be corrected off-line if the absorption part of the aerosol optical thickness (AAOT) is known at the site. However, currently there are no standard methods of measuring AAOT ( or aerosol single-scattering albedo) in the UV wavelengths even from the ground. The new AAOT product from Ozone Monitoring Instrument on board of NASA EOS Aura satellite ( launched in July 2004) could be used to reduce the bias along with other improvements. This is currently a subject of ongoing research. C1 Univ Extremadura, Dept Fis, E-06071 Badajoz, Spain. Univ Valladolid, Dept Fis Teor Atom & Opt, Grp Opt Atmosfer, E-47071 Valladolid, Spain. Inst Nacl Tecn Aeroesp, ESAt Arenosillo, Huelva, Spain. NASA, Goddard Space Flight Ctr, Lab Atmosphere, Greenbelt, MD 20771 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. RP Anton, M (reprint author), Univ Extremadura, Dept Fis, E-06071 Badajoz, Spain. EM chiqui@baraja.opt.cie.uva.es RI Toledano, Carlos/J-3672-2012; Anton, Manuel/A-8477-2010; Krotkov, Nickolay/E-1541-2012; Serrano, Antonio/M-2789-2014; OI Toledano, Carlos/0000-0002-6890-6648; Krotkov, Nickolay/0000-0001-6170-6750; Serrano, Antonio/0000-0001-8881-0785; Anton, Manuel/0000-0002-0816-3758; Cachorro, Victoria/0000-0002-4627-9444; Herman, Jay/0000-0002-9146-1632 NR 42 TC 8 Z9 8 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-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 7 PY 2007 VL 112 IS D11 AR D11206 DI 10.1029/2006JD007254 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177GF UT WOS:000247140900001 ER PT J AU Kahn, RA Li, WH Moroney, C Diner, DJ Martonchik, JV Fishbein, E AF Kahn, Ralph A. Li, W.-H. Moroney, Catherine Diner, David J. Martonchik, John V. Fishbein, Evan TI Aerosol source plume physical characteristics from space-based multiangle imaging SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CLOUD-TOP HEIGHTS; FOREST-FIRE SMOKE; LARGE AREA FIRES; MISR; MODIS; TRANSPORT; RETRIEVAL; MODEL; OCEAN; DISTRIBUTIONS AB [1] Models that assess aerosol effects on regional air quality and global climate parameterize aerosol sources in terms of amount, type, and injection height. The multiangle imaging spectroradiometer (MISR) aboard NASA's Terra satellite retrieves total column aerosol optical thickness (AOT), and aerosol type over cloud-free land and water. A stereo-matching algorithm automatically retrieves reflecting-layer altitude wherever clouds or aerosol plumes have discernable spatial contrast, with about 500-m accuracy, at 1.1-km horizontal resolution. Near-source biomass burning smoke, volcanic effluent, and desert dust plumes are observed routinely, providing information about aerosol amount, particle type, and injection height useful for modeling applications. Compared to background aerosols, the plumes sampled have higher AOT, contain particles having expected differences in Angstrom exponent, size, single-scattering albedo, and for volcanic plume and dust cloud cases, particle shape. As basic thermodynamics predicts, thin aerosol plumes lifted only by regional winds or less intense heat sources are confined to the boundary layer. However, when sources have sufficient buoyancy, the representative plumes studied tend to concentrate within discrete, high-elevation layers of local stability; the aerosol is not uniformly distributed up to a peak altitude, as is sometimes assumed in modeling. MISR-derived plume heights, along with meteorological profile data from other sources, make it possible to relate radiant energy flux observed by the moderate resolution imaging spectroradiometer ( MODIS), also aboard the Terra spacecraft, to convective heat flux that plays a major role in buoyant plume dynamics. A MISR climatology of plume behavior based on these results is being developed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kahn, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ralph.kahn@jpl.nasa.gov RI Kahn, Ralph/D-5371-2012 OI Kahn, Ralph/0000-0002-5234-6359 NR 45 TC 105 Z9 107 U1 2 U2 14 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 7 PY 2007 VL 112 IS D11 AR D11205 DI 10.1029/2006JD007647 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177GF UT WOS:000247140900002 ER PT J AU Yingst, RA Haldemann, AFC Biedermann, KL Monhead, AM AF Yingst, R. Aileen Haldemann, A. F. C. Biedermann, Kimberly L. Monhead, Aimee M. TI Quantitative morphology of rocks at the Mars Pathfinder landing site SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID CHRYSE PLANITIA; SHAPE; PARTICLES; ROVER; ROUNDNESS; DEPOSITS; MISSION; CONSTRAINTS; OPERATIONS; SOJOURNER AB [1] We adapt and test a standard terrestrial technique of assessing morphology quantitatively for use with sites on Mars based on two-dimensional equations and particle outlines, whereby images of particles obtained remotely may yield dimensionless, numerical shape and roundness values consistent with previous knowledge of the lithology and sedimentary transport history. Our test site was the particle-rich Rock Garden at the Mars Pathfinder landing site, a location where the primary geologic processes and lithology have been determined by other means. A total of 575 particles were assessed in terms of size, sphericity, elongation, and roundness; qualitative roundness was determined for 460 particles. Particles are mostly pebble- to cobble-sized and have an average sphericity of 0.75, elongation of 0.63, and relative roundness of 0.083; 69% of particles are subangular or subrounded. Particle sphericity is unimodal, with a size-sphericity profile matching trends for terrestrial populations of similar lithology and elongations nearly identical to those for particles at Vikings 1 and 2. This matches the predictions for a site with the single overall lithology implied from other analyses. Roundness data indicate one or possibly two particle populations, representing the primary processes that likely affected particle roundness most strongly: impact and catastrophic flooding. Finally, we tested a hypothesis suggesting that darker, smaller, more angular particles comprise a population transported through impact cratering, while larger, less dark, more rounded particles are associated with catastrophic flood transport. The opposite result is seen: larger particles throughout the Rock Garden are more angular than smaller ones. C1 Univ Wisconsin, Green Bay, WI 54311 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yingst, RA (reprint author), Univ Wisconsin, 2420 Nicolet Dr, Green Bay, WI 54311 USA. EM yingsta@uwgb.edu NR 85 TC 14 Z9 14 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-PLANET JI J. Geophys. Res.-Planets PD JUN 7 PY 2007 VL 112 IS E6 AR E06002 DI 10.1029/2005JE002582 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 177GU UT WOS:000247142400001 ER PT J AU Harrington, J Luszcz, S Seager, S Deming, D Richardson, LJ AF Harrington, Joseph Luszcz, Statia Seager, Sara Deming, Drake Richardson, L. Jeremy TI The hottest planet SO NATURE LA English DT Article ID SPITZER-SPACE-TELESCOPE; EXTRASOLAR PLANET; HD 189733B; THERMAL EMISSION; HOT JUPITERS; ATMOSPHERES; 149026B; SPECTRUM; CORE AB Of the over 200 known extrasolar planets, just 14 pass in front of and behind their parent stars as seen from Earth. This fortuitous geometry allows direct determination of many planetary properties(1). Previous reports of planetary thermal emission(2-5) give fluxes that are roughly consistent with predictions based on thermal equilibrium with the planets' received radiation, assuming a Bond albedo of similar to 0.3. Here we report direct detection of thermal emission from the smallest known transiting planet, HD149026b, that indicates a brightness temperature ( an expression of flux) of 2,300 +/- 6200K at 8 mm. The planet's predicted temperature for uniform, spherical, blackbody emission and zero albedo ( unprecedented for planets) is 1,741 K. As models with non-zero albedo are cooler, this essentially eliminates uniform blackbody models, and may also require an albedo lower than any measured for a planet, very strong 8 mm emission, strong temporal variability, or a heat source other than stellar radiation. On the other hand, an instantaneous re-emission blackbody model, in which each patch of surface area instantly re-emits all received light, matches the data. This planet is known(6-9) to be enriched in heavy elements, which may give rise to novel atmospheric properties yet to be investigated. C1 Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, Planetary Syst Lab, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Exoplanet & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. RP Harrington, J (reprint author), Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. EM jharring@physics.ucf.edu RI Harrington, Joseph/E-6250-2011; OI Harrington, Joseph/0000-0002-8955-8531 NR 27 TC 109 Z9 109 U1 1 U2 5 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUN 7 PY 2007 VL 447 IS 7145 BP 691 EP 693 DI 10.1038/nature05863 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 175RI UT WOS:000247030700038 PM 17495928 ER PT J AU Livingston, J Schmid, B Redemann, J Russell, PB Ramirez, SA Eilers, J Gore, W Howard, S Pommier, J Fetzer, EJ Seemann, SW Borbas, E Wolfe, DE Thompson, AM AF Livingston, J. Schmid, B. Redemann, J. Russell, P. B. Ramirez, S. A. Eilers, J. Gore, W. Howard, S. Pommier, J. Fetzer, E. J. Seemann, S. W. Borbas, E. Wolfe, D. E. Thompson, A. M. TI Comparison of water vapor measurements by airborne Sun photometer and near-coincident in situ and satellite sensors during INTEX/ITCT SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RESOLUTION IMAGING SPECTRORADIOMETER; SOLAR TRANSMITTANCE MEASUREMENTS; LOWER TROPOSPHERIC AEROSOL; GROUND-BASED MEASUREMENTS; OPTICAL-DEPTH SPECTRA; COLUMN CLOSURE; ACE-ASIA; CALIBRATION; RETRIEVALS; MODIS AB We have retrieved columnar water vapor (CWV) from measurements acquired by the 14-channel NASA Ames Airborne Tracking Sun photometer (AATS-14) during 19 Jetstream 31 (J31) flights over the Gulf of Maine in summer 2004 in support of the Intercontinental Chemical Transport Experiment (INTEX)/Intercontinental Transport and Chemical Transformation (ITCT) experiments. In this paper we compare AATS-14 water vapor retrievals during aircraft vertical profiles with measurements by an onboard Vaisala HMP243 humidity sensor and by ship radiosondes and with water vapor profiles retrieved from AIRS measurements during eight Aqua overpasses. We also compare AATS CWV and MODIS infrared CWV retrievals during five Aqua and five Terra overpasses. For 35 J31 vertical profiles, mean (bias) and RMS AATS-minus-Vaisala layer-integrated water vapor (LWV) differences are -7.1% and 8.8%, respectively. For 22 aircraft profiles within 1 hour and 130 km of radiosonde soundings, AATS-minus-sonde bias and RMS LWV differences are -5.4% and 10.7%, respectively, and corresponding J31 Vaisala-minus-sonde differences are 2.3% and 8.4%, respectively. AIRS LWV retrievals within 80 km of J31 profiles yield lower bias and RMS differences compared to AATS or Vaisala retrievals than do AIRS retrievals within 150 km of the J31. In particular, for AIRS-minus-AATS LWV differences, the bias decreases from 8.8% to 5.8%, and the RMS difference decreases from 21.5% to 16.4%. Comparison of vertically resolved AIRS water vapor retrievals (LWVA) to AATS values in fixed pressure layers yields biases of -2% to +6% and RMS differences of similar to 20% below 700 hPa. Variability and magnitude of these differences increase significantly above 700 hPa. MODIS IR retrievals of CWV in 205 grid cells (5 x 5 km at nadir) are biased wet by 10.4% compared to AATS over-ocean near-surface retrievals. The MODIS-Aqua subset (79 grid cells) exhibits a wet bias of 5.1%, and the MODIS-Terra subset (126 grid cells) yields a wet bias of 13.2%. C1 SRI Int, Menlo Pk, CA 94025 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI 53706 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Bay Area Environm Res Inst, Sonoma, CA 95476 USA. RP Livingston, J (reprint author), SRI Int, 333 Ravenswood Ave, Menlo Pk, CA 94025 USA. EM john.livingston@sri.com; beat.schmid@pub.gov; jredemann@mail.arc.nasa.gov; philip.b.russell@nasa.gov; s.a.ramirez@mail.arc.nasa.gov; jeilers@mail.arc.nasa.gov; warren.j.gore@nasa.gov; howard@solat.arc.nasa.gov; jpommier@mail.arc.nasa.gov; eric.j.fetzer@jpl.nasa.gov; swetzel@ssec.wisc.edu; evab@ssec.wisc.edu; daniel.wolfe@noaa.gov; anne@met.psu.edu RI Thompson, Anne /C-3649-2014 OI Thompson, Anne /0000-0002-7829-0920 NR 51 TC 17 Z9 17 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 6 PY 2007 VL 112 IS D12 AR 2004D12S16 DI 10.1029/2006JD007733 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177GK UT WOS:000247141400001 ER PT J AU Webber, WR Cummings, AC McDonald, FB Stone, EC Heikkila, B Lal, N AF Webber, W. R. Cummings, A. C. McDonald, F. B. Stone, E. C. Heikkila, B. Lal, N. TI Temporal and spectral variations of anomalous oxygen nuclei measured by Voyager 1 and Voyager 2 in the outer heliosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TERMINATION SHOCK; SOLAR-WIND; COSMIC-RAYS; PARTICLE-ACCELERATION; HELIOSHEATH; MODULATION; COMPONENT; PROTONS; HELIUM AB We have studied the temporal and spectral variations of anomalous oxygen nuclei at the Voyager 1 (V1) and 2 (V2) spacecraft in the outer heliosphere from 1990 to the present time in 2006 when V1 is now beyond the heliospheric termination shock. During this time period, the intensities increased from their lowest values in 1990-1991 up to a maximum in 1998-1999 and then decreased rapidly in 2000-2001 in time coincidence with the change in solar magnetic polarity from positive to negative. During the time period after 2001, significant changes in intensities and spectra are observed relative to the earlier period of positive solar magnetic polarity before 2001. It is found that the intensities of O above similar to 10 MeV/nuc at V1 after similar to 2002.0 were higher relative to the same galactic cosmic ray He intensity between 150-380 MeV/nuc than in the earlier time period. As a result, by 2006 these intensities were a factor similar to 3 times those measured at the intensity maximum in 1998-1999 in the previous polarity cycle. The changes observed at V2 followed a similar pattern, but the relative intensity changes of O were a factor similar to 2 times greater than those observed at V1. Also, above similar to 10 MeV/nuc, the intensity changes at V1 and V2 were nearly energy independent, and the spectra at all times before and after the solar magnetic polarity change and at all modulation levels remained similar to E-3.0 +/- 0.2, possibly characteristic of a "source'' spectrum. When V1 crossed the termination shock, no noticeable spectral or intensity changes were observed. C1 New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. CALTECH, Downs Lab, Pasadena, CA 91125 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Webber, WR (reprint author), New Mexico State Univ, Dept Astron, MSC 45000,POB 30001,1320 Frenger St, Las Cruces, NM 88003 USA. EM bwebber@nmsu.edu NR 22 TC 2 Z9 2 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 5 PY 2007 VL 112 IS A6 AR A06105 DI 10.1029/2006JA012207 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 177GY UT WOS:000247142800006 ER PT J AU Picard, YN Twigg, ME Caldwell, JD Eddy, CR Neudeck, PG Trunek, AJ Powell, JA AF Picard, Y. N. Twigg, M. E. Caldwell, J. D. Eddy, C. R., Jr. Neudeck, P. G. Trunek, A. J. Powell, J. A. TI Electron channeling contrast imaging of atomic steps and threading dislocations in 4H-SiC SO APPLIED PHYSICS LETTERS LA English DT Article ID NITRIDE; SURFACES; GROWTH; MESAS; MICROSCOPY; EPITAXY; CRACKS; LAYERS AB Direct imaging of atomic step morphologies and individual threading dislocations in on-axis epitaxial 4H-SiC surfaces is presented. Topographically sensitive electron images of the crystalline surfaces were obtained through forescattered electron detection inside a conventional scanning electron microscope. This technique, termed electron channeling contrast imaging (ECCI), has been utilized to reveal the configuration of highly stepped, homoepitaxial 4H-SiC films grown on 4H-SiC mesa structures. Individual threading dislocations have been consistently imaged at the core of spiral atomic step morphologies located on the 4H-SiC surfaces. The ability of ECCI to image atomic steps was verified by atomic force microscopy. (c) 2007 American Institute of Physics. C1 USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. OAI, Cleveland, OH 44135 USA. Sest Inc, Cleveland, OH 44135 USA. RP Picard, YN (reprint author), USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. EM yoosuf.picard@nrl.navy.mil RI Caldwell, Joshua/B-3253-2008; OI Caldwell, Joshua/0000-0003-0374-2168; Picard, Yoosuf/0000-0002-2853-5213 NR 17 TC 36 Z9 36 U1 4 U2 15 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 4 PY 2007 VL 90 IS 23 AR 234101 DI 10.1063/1.2746075 PG 3 WC Physics, Applied SC Physics GA 177HZ UT WOS:000247145500095 ER PT J AU Tripathi, N Grandusky, JR Jindal, V Shahedipour-Sandvika, F Bell, LD AF Tripathi, N. Grandusky, J. R. Jindal, V. Shahedipour-Sandvika, F. Bell, L. D. TI AlGaN based tunable hyperspectral detector SO APPLIED PHYSICS LETTERS LA English DT Article ID LIGHT-EMITTING-DIODES; INTERNAL PHOTOEMISSION; GAN; SPECTROSCOPY; INN AB The application of III-nitrides to the development of a tunable hyperspectral detector is reported. The device consists of a triangular step barrier provided by a heterostructure of AlN/AlxGa1-xN/GaN. The structure is carefully designed to avoid relaxation of strained layers to prevent further introduction of defects and cracking due to the large tensile strain between different layers of the device. This structure is envisioned for tunable detection of ultraviolet through infrared wavelengths. The particular device structure reported here is expected to span detection energies from similar to 1 to 2 eV and from 3.4 to 5.4 eV. The adjustable height of the triangular barrier with applied bias voltage provides tunability of the detected wavelength. The results from a first generation device are reported. (c) 2007 American Institute of Physics. C1 SUNY Albany, Coll Nanoscale Sci & Engn, Albany, NY 12203 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tripathi, N (reprint author), SUNY Albany, Coll Nanoscale Sci & Engn, 1535 Western Ave, Albany, NY 12203 USA. EM sshahedipour@uamail.albany.edu NR 16 TC 6 Z9 6 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 4 PY 2007 VL 90 IS 23 AR 231103 DI 10.1063/1.2746069 PG 3 WC Physics, Applied SC Physics GA 177HZ UT WOS:000247145500003 ER PT J AU Collier, MR Lepping, RP Berdichevsky, DB AF Collier, Michael R. Lepping, Ronald P. Berdichevsky, Daniel B. TI A statistical study of interplanetary shocks and pressure pulses internal to magnetic clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; 23RD SOLAR MINIMUM; 1 AU; WIND; SPACECRAFT; FIELD AB We have examined Wind field and plasma data over the time period from November of 1994 through August of 2003 to find cases of interplanetary shocks and pressure pulses internal to magnetic clouds for which we could determine accurate shock normal directions. We have found eight cases in 82 clouds, so these shocks and pressure pulses occurred in approximately 10% of the Wind magnetic clouds. Of the eight cases, six were forward shocks and two were pressure pulses. The internal shocks and pressure pulses tend to occur in the latter half of the clouds, i.e., timewise, about two-thirds of the way through. In every case the magnetic field change is highly compressive at the shock showing little or no change (<10 degrees) in angle during or after the magnitude jump. These shocks and pressure pulses internal to magnetic clouds appear to be associated with outline asymmetric halo coronal mass ejections of greater than average speed which may imply an interaction between an earlier, slower halo CME and a later, faster, off-center CME driving a strong shock, but other interpretations are possible and they are discussed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Collier, MR (reprint author), NASA, Goddard Space Flight Ctr, Code 673,Bldg 2,Room 246, Greenbelt, MD 20771 USA. EM michael.r.collier@nasa.gov RI Collier, Michael/I-4864-2013 OI Collier, Michael/0000-0001-9658-6605 NR 19 TC 7 Z9 7 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 2 PY 2007 VL 112 IS A6 AR A06102 DI 10.1029/2006JA011714 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174OP UT WOS:000246952000001 ER PT J AU Ofman, L Vinas, AF AF Ofman, L. Vinas, A. F. TI Two-dimensional hybrid model of wave and beam heating of multi-ion solar wind plasma SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTROMAGNETIC PROTON/PROTON INSTABILITIES; ION-CYCLOTRON INSTABILITY; CORONAL HOLES; ALFVEN WAVES; HEAVY-IONS; ACCELERATION; ANISOTROPY; SIMULATIONS; PROTON; CONSTRAINTS AB We study the heating and the acceleration of protons and heavy ions by waves in the solar wind, as well as the nonlinear influence of heavy ions on the wave structure, using a two-dimensional (2-D) hybrid model. Protons and heavy ions are treated kinetically by solving their equations of motion in the self-consistent electric and magnetic fields of the waves, while electrons are treated as a neutralizing background fluid. We use the 2-D hybrid code to investigate more realistic 2-D plasma model than previous 1-D simulation and analytical studies, which allows parallel as well as obliquely propagating waves and localized driver. Using the hybrid code, we consider for the first time the heating and acceleration of protons and heavy ions by a driven-input spectrum of Alfven/cyclotron waves and by heavy ion beam in the multispecies coronal plasma in two spatial dimensions. We find that the ion beam is more efficient in generating temperature anisotropy than the driven wave spectrum in our model. We discuss the observational implication of the results to the solar wind. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Ofman, L (reprint author), NASA, Goddard Space Flight Ctr, Code 671, Greenbelt, MD 20771 USA. EM leon.ofman@gsfc.nasa.gov; adolfo.figueroa-vinas.1@gsfc.nasa.gov NR 33 TC 20 Z9 20 U1 0 U2 3 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 2 PY 2007 VL 112 IS A6 AR A06104 DI 10.1029/2006JA012187 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174OP UT WOS:000246952000009 ER PT J AU Podesta, JJ Goldstein, ML Roberts, DA AF Podesta, J. J. Goldstein, M. L. Roberts, D. A. TI Mode decomposition scheme for ideal magnetohydrodynamic plane waves in space-time coordinates SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CLUSTER; TELESCOPE; PLASMA AB Exact nonsinusoidal plane wave solutions of the linearized equations of ideal magnetohydrodynamics are used to develop a decomposition scheme for extracting the forward and backward propagating components of the fast, slow, and Alfven modes from measured data. The decomposition technique is formulated in the space-time domain for waves propagating in one direction. The different wave modes are extracted by means of projection operators that are expressed in matrix form. Because the elements of these matrices are constants, the same projection operators can be used to obtain the mode decomposition in the frequency (Fourier) domain. The projection operators are identical to those obtained by Glassmeier et al. (1995) although they are derived here by different means. In the case of wave propagation parallel or perpendicular to the background magnetic field the wave modes are degenerate and require separate treatment. These special cases are included in the present analysis so the resulting decomposition scheme encompasses all possible propagation directions. C1 NASA, Goddard Space Flight Ctr, Lab Solar & Space Phys, Greenbelt, MD 20771 USA. RP Podesta, JJ (reprint author), NASA, Goddard Space Flight Ctr, Lab Solar & Space Phys, Greenbelt, MD 20771 USA. EM jpodesta@solar.stanford.edu RI Roberts, Dana/D-4625-2012; Goldstein, Melvyn/B-1724-2008 NR 13 TC 0 Z9 0 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 2 PY 2007 VL 112 IS A6 AR A06103 DI 10.1029/2006JA012097 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174OP UT WOS:000246952000005 ER PT J AU Clement, JL Boyd, JE Kanas, N Saylor, S AF Clement, James L. Boyd, Jennifer E. Kanas, Nick Saylor, Stephanie TI Leadership challenges in ISS operations: Lessons learned from junior and senior mission control personnel SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law ID INTERNATIONAL-SPACE-STATION; SHUTTLE/MIR; TEAMS AB The International Space Station (ISS) is operated by a multi-national, multi-organizational team that is dispersed across multiple locations, time zones, and work schedules. At NASA, mission control personnel have had to find ways to address the leadership challenges inherent in,such work, but have not had systematic training on how to do so. We interviewed 12 junior controllers and 14 senior controllers to examine the major leadership challenges they face and to highlight the solutions that they have found most effective to surmount them. We compare the perspectives of the two groups. Further, we contextualize our survey results with new analyses of standardized questionnaire data from 186 mission control personnel and a contrasting group of 30 space station crewmembers. The interview data showed that respondents had substantial consensus on several leadership challenges and on key strategies for dealing with them, but junior and senior controllers' perspectives were different. The questionnaire data showed that the US mission control sample reported a level of support from their management that compared favorably to national norms. Although specific to space station personnel, our results are consistent with recent management, cultural, and aerospace research. (c) 2007 Elsevier Ltd. All rights reserved. C1 Univ Calif San Francisco, Dept Vet Affairs Med Ctr, San Francisco, CA 94143 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Boyd, JE (reprint author), Univ Calif San Francisco, Dept Vet Affairs Med Ctr, San Francisco, CA 94143 USA. EM james.l.clement@nasa.gov; jennifer.boyd@ucsf.edu; nick.kanas@ucsf.edu; stephanie.saylor@va.gov NR 20 TC 2 Z9 2 U1 2 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 JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 2 EP 7 DI 10.1016/j.actaastro.2007.01.014 PG 6 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600002 ER PT J AU Jules, K Lin, PP AF Jules, Kenol Lin, Paul P. TI Real-time on-line space research laboratory environment monitoring with off-line trend and prediction analysis SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB With the International Space Station currently operational, a significant amount of acceleration data is being down-linked, processed and analyzed daily on the ground on a continuous basis for the space station reduced gravity environment characterization, the vehicle design requirements verification and science data collection. To help understand the impact of the unique spacecraft environment on the science data, an artificial intelligence monitoring system was developed, which detects in near real time any change in the reduced gravity environment susceptible to affect the on-going experiments. Using a dynamic graphical display, the monitoring system allows science teams, at any time and any location, to see the active vibration disturbances, such as pumps, fans, compressor, crew exercise, re-boost and extra-vehicular activities that might impact the reduced gravity environment the experiments are exposed to. The monitoring system can detect both known and unknown vibratory disturbance activities. It can also perform trend analysis and prediction by analyzing past data over many increments (an increment usually lasts 6 months) collected onboard the station for selected disturbances. This feature can be used to monitor the health of onboard mechanical systems to detect and prevent potential systems failures. The monitoring system has two operating modes: online and offline. Both near real-time on-line vibratory disturbance detection and off-line detection and trend analysis are discussed in this paper. (c) 2007 Elsevier Ltd. All rights reserved. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Cleveland State Univ, Cleveland, OH 44115 USA. RP Jules, K (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code 0Z-4,2101 NASA Pkwy, Houston, TX 77058 USA. EM kenol.jules-1@nasa.gov NR 17 TC 0 Z9 1 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 JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 27 EP 36 DI 10.1016/j.actaastro.2007.01.028 PG 10 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600005 ER PT J AU Mitchell, RT AF Mitchell, Robert T. TI The Cassini Mission at Saturn SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB The Cassini Mission to Saturn, a joint undertaking by NASA, the European Space Agency, and the Italian Space Agency, is now at about the mid-point of its planned four-year tour of the Saturnian system. Close encounters with Titan and the smaller icy satellites are occurring on schedule, and observations of these bodies along with Saturn's atmosphere, its rings, and magnetosphere are being made and scientific data returned on a daily basis. The icy satellites are turning out to be more distinct and unique than had been anticipated, the dynamics of the ring particles have been shown to be even more extensive than expected, and Titan's atmosphere had surprises for both the scientists as well as the engineers. A denser than expected upper atmosphere of Titan has led to the requirement to modify the planned orbital tour about Saturn to increase the flyby altitudes for about 20 of the Titan flybys to values above the originally planned 950 kin level in order to avoid the risk of atmospherically induced torques causing the spacecraft to be unable to maintain its commanded attitude. Navigation of the spacecraft on the tour continues to go exceptionally well, with optical navigation enabling delivery accuracies to some of the satellites down to the 1 or 2 km level, and propellant consumption is running slightly below budget. Science observation sequence development and execution have been highly successful in acquiring virtually all of the originally designed observations. This paper summarizes the supporting engineering activities over the past year in support of operating the mission, as well as provides a high-level summary of the scientific results of the Cassini mission to date. (c) 2007 Published by Elsevier Ltd. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mitchell, RT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM robert.t.mitchell@jpl.nasa.gov NR 1 TC 5 Z9 5 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 JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 37 EP 43 DI 10.1016/j.actaastro.2007.01.031 PG 7 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600006 ER PT J AU Graf, JE Zurek, RW Erickson, JK Jai, B Johnston, MD de Paula, R AF Graf, James E. Zurek, Richard W. Erickson, James K. Jai, Benhan Johnston, M. D. de Paula, Ramon TI Status of Mars Reconnaissance Orbiter Mission SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB The Mars Reconnaissance Orbiter (MRO) was launched on August 12, 2005 by an Atlas V 401 expendable launch vehicle from Cape Canaveral Air Force Station, Florida, USA. After the seven-month cruise phase from Earth to Mars, the spacecraft burned its main engines for approximately 27 min and was inserted into Mars orbit on March 10, 2006. During the post-MOI period, four instruments acquired early engineering-quality data. Subsequently, the aerobraking phase was conducted for approximately five months, followed by one month of engineering and instrument checkout. The spacecraft supports 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. 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. While in this science phase, the orbiter will provide telecommunications support for Phoenix spacecraft launched to Mars in 2007. After the primary science phase is complete, the orbiter will enter into its formal relay mode and support the Mars Science Laboratory, which will be launched in the 2009 opportunity. The primary mission ends on December 31, 2010, approximately 5.5 years after launch. Published by Elsevier Ltd. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA HQ, Directorate Mission & Sci, Washington, DC 20546 USA. RP Graf, JE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jegraf@jpl.nasa.gov NR 5 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 JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 44 EP 51 DI 10.1016/j.actaastro.2007.01.032 PG 8 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600007 ER PT J AU Edberg, SJ Traub, WA Unwin, SC Marr, JC AF Edberg, Stephen J. Traub, Wesley A. Unwin, Stephen C. Marr, James C. TI The SIM PlanetQuest science program SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB SIM PlanetQuest (hereafter, just SIM) is a NASA mission to measure the angular positions of stars with unprecedented accuracy. We outline the main astrophysical science programs planned for SIM, and related opportunities for community participation. We focus especially on SIM's ability to detect exoplanets; as small as the Earth around nearby stars. The planned synergy between SIM and other planet-finding missions including Kepler and GAIA, and planet-characterizing missions including the James Webb Space Telescope (JWST), Terrestrial Planet Finder-Coronagraph (TPF-Q, and Terrestrial Planet Finder-Interferometer (TPF-1), is a key element in NASNs Navigator Program to find Earth-like planets, determine their habitability, and search for signs of life in the universe. SIM's technology development is now complete and the project is proceeding towards a launch in the next decade. (c) 2007 Elsevier Ltd. All rights reserved. C1 CALTECH, NASA, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Edberg, SJ (reprint author), CALTECH, NASA, Jet Propuls Lab, Pasadena, CA 91125 USA. EM Stephen.J.Edberg@jpl.nasa.gov; Wesley.A.Traub@jpl.nasa.gov; Stephen.C.Unwin@jpl.nasa.gov; James.C.Marr@jpl.nasa.gov NR 8 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 52 EP 62 DI 10.1016/j.actaastro.2007.01.036 PG 11 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600008 ER PT J AU Edwards, CD DePaula, R AF Edwards, C. D., Jr. DePaula, R. TI Key telecommunications technologies for increasing data return for future Mars exploration SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB NASA's plans for Mars exploration demand increasing telecommunications capabilities in the coming decades. Ambitious robotic missions will deploy high-rate instruments in Mars orbit and on the Martian surface, with increasing spatial, spectral, and temporal resolution. Orbiters will require high-performance direct-to-Earth links, while landed missions will benefit from energy-efficient communications through relay-equipped orbiters to increase data return while minimizing landed mass. The Mars Reconnaissance Orbiter and the Mars Exploration Rovers define the current state-of-the-art for Martian orbiters and landers, respectively. Even with respect to these capabilities, however, significant growth appears to be very feasible based on infusion of relatively mature technologies. Deployable spacecraft antennas, high-power traveling wave tube amplifiers, and migration to Ka-band provide a path to much higher spacecraft equivalent isotropic radiated power. When combined with proposed upgrades to the Deep Space Network, future orbiters can envision downlink rates more than two orders of magnitude beyond current capability. Similar growth can be achieved on relay links between landers and relay orbiters, based on improved relay capabilities which can be infused into the current generation of Electra software-defined relay radios, and by migration to high-frequency directional relay links. (c) 2007 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Washington, DC 20546 USA. RP Edwards, CD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM chad.edwards@jpl.nasa.gov NR 7 TC 11 Z9 13 U1 2 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 JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 131 EP 138 DI 10.1016/j.actaastro.2007.01.016 PG 8 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600016 ER PT J AU Robinson, JA Thumm, TL Thomas, DA AF Robinson, Julie A. Thumm, Tracy L. Thomas, Donald A. TI NASA utilization of the international space station and the Vision for Space Exploration SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law ID LONG-DURATION SPACEFLIGHT AB In response to the US President's Vision for Space Exploration (January 14, 2004), NASA has revised its utilization plans for International Space Station (ISS) to focus on (1) research on astronaut health and the development of countermeasures that will protect our crews from the space environment during long-duration voyages, (2) ISS as a test bed for research and technology developments that will insure vehicle systems and operational practices are ready for future exploration missions, (3) developing and validating operational practices and procedures for long-duration space missions. In addition, NASA will continue a small amount of fundamental research in life and microgravity sciences. There have been significant research accomplishments that are important for achieving the Exploration Vision. Some of these have been formal research payloads, while others have come from research based on the operation of ISS. We will review a selection of these experiments and results, as well as outline some of ongoing and upcoming research. The ISS represents the only microgravity opportunity to perform on-orbit long-duration studies of human health and performance and technologies relevant for future long-duration missions planned during the next 25 years. Even as NASA focuses on developing the Orion spacecraft and return to the moon (2015-2020), research on and operation of the ISS is fundamental to the success of NASA:s Exploration Vision. Published by Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Off ISS Program Scientist, Houston, TX 77058 USA. RP Robinson, JA (reprint author), NASA, Lyndon B Johnson Space Ctr, Off ISS Program Scientist, Houston, TX 77058 USA. EM julie.a.robinson@nasa.gov OI Robinson, Julie/0000-0002-6832-6459 NR 16 TC 7 Z9 11 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 176 EP 184 DI 10.1016/j.actaastro.2007.01.019 PG 9 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600021 ER PT J AU Johnson, NL AF Johnson, Nicholas L. TI Current characteristics and trends of the tracked satellite population in the human space flight regime SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB Since the end of the Apollo program in 1972, human space flight has been restricted to altitudes below 620km above the Earth's surface with most missions restricted to a ceiling below 400 km. An investigation of the tracked satellite population transiting and influencing the human space flight regime during the past I I years (equivalent to a full solar cycle) has recently been completed. The overall effects of satellite breakups and solar activity are typically less pronounced in the human space flight regime than other regions of low Earth orbit. As of January 2006 nearly 1500 tracked objects resided in or traversed the human space flight regime, although two-thirds of these objects were in orbits of moderate to high eccentricity. Since the beginning of the International Space Station era, the spatial density of tracked objects in the 350-400km altitude regime has demonstrated a general decline, decreasing by 40% by the beginning of 2006. On the other hand, the region immediately above 600km experienced a significant increase in its population density. This regime is important for future risk assessments, since this region represents the reservoir of debris which will influence human space flight safety in the future. The paper seeks to put into sharper perspective the risks posed to human space flight by the tracked satellite population, as well as the influences of solar activity and the effects of compliance with orbital debris mitigation guidelines on human space flight missions. Finally, the methods and successes of characterizing the population of smaller debris in human space flight regimes are addressed. Published by Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Johnson, NL (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM Nicholas.L.Johnson@nasa.gov NR 1 TC 1 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 257 EP 264 DI 10.1016/j.actaastro.2007.01.013 PG 8 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600031 ER PT J AU Bacon, J Menkin, E AF Bacon, Jack Menkin, Evgeny TI Generalized separation of an object jettisoned from the ISS SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB The International Space Station (ISS) Program faces unprecedented logistics challenges in both upmass and downmass. Some items employed on the ISS exterior present significant technical issues for a controlled de-orbit on either the shuttle or an expendable supply vehicle. Such manifest problems arise due to structural degradation, insufficient containment of hazardous pressures or contents, excessive size, or some combination of all of these factors. In addition, the mounting hardware and other flight service equipment to manifest the returned equipment must itself be launched, competing with other upmass. EVA techniques and equipment to successfully contain and secure such problematic equipment result in numerous significant risks to the spacewalking crews and cost and schedule risks to the program. The ISS Program office has therefore developed a policy that advises the jettison of the most problematic objects. Such jettisoned items join a small family of nearly co-planar orbital debris objects that threaten the ISS on several timescales, besides threatening all satellites with perigee below the ISS orbit and the general human population on the Earth. This analysis addresses the governing physics and the ensuing risks when an object is jettisoned. It is shown that there are four time domains which must be considered, each with its own inherent problems, and that a ballistic solution is usually possible that satisfies all constraints in all domains. (c) 2007 Published by Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. ARES Corp, Houston, TX USA. RP Bacon, J (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM john.bacon-1@nasa.gov; evgeny.menkin-1@nasa.gov NR 3 TC 1 Z9 1 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 JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 265 EP 276 DI 10.1016/j.actaastro.2007.01.045 PG 12 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600032 ER PT J AU Johnson, L Young, RM Montgomery, EE AF Johnson, Les Young, Roy M. Montgomery, Edward E. TI Recent advances in solar sail propulsion systems at NASA SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB Supporting NASA's Science Mission Directorate, the In-Space Propulsion Technology (ISPT) Program is developing solar sail propulsion (SSP) for use in robotic science and exploration of the solar system. SSP will provide longer on-station operation, increased scientific payload mass fraction, and access to previously inaccessible orbits for multiple potential science missions. Two different 20-m solar sail systems were produced and successfully completed functional vacuum testing last year in NASA Glenn's Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by ATK Space Systems and L:Garde, respectively. These sail systems consist of a central structure with four deployable booms that support the sails. These sail designs are robust enough for deployments in a one atmosphere, one gravity environment, and are scalable to much larger solar sails-perhaps as much as 150 m on a side. In addition, computation modeling and analytical simulations have been performed to assess the scalability of the technology to the large sizes (> 150m) required for first generation solar sail missions. Life and space environmental effects testing of sail and component materials are also nearly complete. This paper will summarize recent technology advancements in solar sails and their successful ambient and vacuum testing. Published by Elsevier Ltd. C1 NASA, George C Marshall Space Flight Ctr, Sci Programs & Projects Off, Huntsville, AL 35812 USA. NASA, George C Marshall Space Flight Ctr, Solar Sail Propuls Technol Project, Huntsville, AL 35812 USA. RP Johnson, L (reprint author), NASA, George C Marshall Space Flight Ctr, Sci Programs & Projects Off, Huntsville, AL 35812 USA. EM C.Les.Johnson@nasa.gov; roy.m.young@nasa.gov; edward.e.montgomery@nasa.gov NR 17 TC 14 Z9 17 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 JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 376 EP 382 DI 10.1016/j.actaastro.2007.01.047 PG 7 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600043 ER PT J AU Thomas, LD AF Thomas, L. Dale TI Selected systeras engineering process deficiencies and their consequences SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB The systems engineering process is well established and well understood. While this statement could be argued in the light of the many systems engineering guidelines and that have been developed, comparative review of these respective descriptions reveal that they differ primarily in the number of discrete steps or other nuances, and are at their core essentially common. Likewise, the systems engineering textbooks differ primarily in the context for application of systems engineering or in the utilization of evolved tools and techniques, not in the basic method. Thus, failures in systems engineering cannot credibly be attributed to implementation of the wrong systems engineering process among alternatives. However, numerous system failures can be attributed to deficient implementation of the systems engineering process. What may clearly be perceived as a systems engineering deficiency in retrospect can appear to be a well considered system engineering efficiency in real time-an efficiency taken to reduce cost or meet a schedule, or more often both. Typically these efficiencies are grounded on apparently solid rationale, such as reuse of heritage hardware or software. Over time, unintended consequences of a systems engineering process deficiency may begin to be realized, and unfortunately often the consequence is systems failure. This paper describes several actual cases of system failures that resulted from deficiencies in their systems engineering process implementation, including the Ariane 5 and the Hubble Space Telescope. (c) 2007 Elsevier Ltd. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Thomas, LD (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM dale.thomas@nasa.gov NR 9 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 JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 406 EP 415 DI 10.1016/j.actaastro.2007.01.005 PG 10 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600047 ER PT J AU Cockrell, CE Davis, SR Robinson, K Tuma, ML Sullivan, G AF Cockrell, Charles E. Davis, Stephan R. Robinson, Kimberly Tuma, Margaret L. Sullivan, Greg TI NASA crew launch vehicle flight test options SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 57th Congress of the International-Astronautical-Federation (IAF) CY OCT 02-06, 2006 CL Valencia, SPAIN SP Int Astronaut Federat, Int Acad Astronaut, Int Inst Space Law AB Options for development flight testing (DFT) of the Ares I crew launch vehicle (CLV) are discussed. The Ares I CLV is being developed by the US National Aeronautics and Space Administration (NASA) to launch the crew exploration vehicle (CEV) into low Earth orbit (LEO). The Ares I implements one of the components of the vision for space exploration (VSE), providing crew and cargo access to the International Space Station (ISS) after retirement of the space shuttle and, eventually, forming part of the launch capability needed for lunar exploration. The role of DFT is to demonstrate key subsystems, address key technical risks, and provide flight data to validate engineering models in representative flight environments. This is distinguished from certification flight testing, which is designed to formally validate system functionality and achieve flight readiness. Lessons learned from Saturn V, space shuttle, and other flight programs are examined along with key Ares I technical risks in order to provide insight into possible DFF strategies. A strategy for the first test flight of the Ares 1, known as Ares I-1, is presented. (c) 2007 Published by Elsevier Ltd. C1 NASA, Ares Project Implementat Off, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Flight & Integrated Test Off, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. GPS Solut Inc, Reno, NV USA. RP Cockrell, CE (reprint author), NASA, Ares Project Implementat Off, Langley Res Ctr, Mail Stop 176, Hampton, VA 23681 USA. EM Charles.E.Cockrell@nasa.gov; gpa@aol.com NR 14 TC 0 Z9 0 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 JUN-AUG PY 2007 VL 61 IS 1-6 SI SI BP 438 EP 449 DI 10.1016/j.actaastro.2007.01.051 PG 12 WC Engineering, Aerospace SC Engineering GA 177MQ UT WOS:000247157600051 ER PT J AU Balint, TS Jordan, JF AF Balint, Tibor S. Jordan, James F. TI RPS strategies to enable NASA's next decade robotic Mars missions SO ACTA ASTRONAUTICA LA English DT Article AB NASA's proposed roadmap for robotic Mars exploration over the next decade is influenced by science goals, technology needs and budgetary considerations. These requirements could introduce potential changes to the succession of missions, resulting in both technology feed forward and heritage. For long duration robotic surface missions at locations, where solar power generation is not feasible or limited, Radioisotope Power Systems (RPS) could be considered. Thus, RPSs could provide enabling power technologies for some of these missions, covering a power range from 10s of milliwatts to potentially a kilowatt or even higher. Currently, NASA and DoE with their industry partners are developing two RPSs, both generating about 110 W(e) at BOL. These systems will be made available as early as 2009. The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG)-with static power conversion-was down-selected as a potential power source for the MSL mission. Development of small-RPSs is in a planning stage by NASA and DoE; potentially targeting both the 10s of milliwatts and 10s of watts power ranges. If developed, Radioisotope Heat Unit (RHU) based systems-generating 10s to 100s of milliwatts-could power small adjunct elements on larger missions, while the GPHS module-based systems-each generating 10s of watts-could be stacked to provide the required power levels on MER class surface assets. MMRTGs and Stirling Radioisotope Generators (SRGs) could power MSL class or larger missions. Advanced Radioisotope Power Systems (ARPS) with higher specific powers and increased power conversion efficiencies could enhance or even enable missions towards the second half of the next decade. This study examines the available power system options and power selection strategies in line with the proposed mission lineup, and identifies the benefits and utility of the various options for each of the next decade launch opportunities. (c) 2007 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Balint, TS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 301-170U, Pasadena, CA 91109 USA. EM tibor.balint@jpl.nasa.gov NR 13 TC 5 Z9 5 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JUN PY 2007 VL 60 IS 12 BP 992 EP 1001 DI 10.1016/j.actaastro.2006.12.003 PG 10 WC Engineering, Aerospace SC Engineering GA 165TJ UT WOS:000246328300006 ER PT J AU Russell, MJ AF Russell, Michael J. TI The alkaline solution to the emergence of life: Energy, entropy and early evolution SO ACTA BIOTHEORETICA LA English DT Review DE acetyl phosphate; CODH/ACS; iron sulfide; hydrothermal; OEC; pyrophosphate ID BANDED IRON FORMATIONS; CITY HYDROTHERMAL FIELD; CARBON-MONOXIDE DEHYDROGENASE; CATALYZED RNA POLYMERIZATION; ANION-BINDING MOTIFS; MID-ATLANTIC RIDGE; AMINO-ACIDS; GENETIC-CODE; SEA-FLOOR; EARLY EARTH AB The Earth agglomerates and heats. Convection cells within the planetary interior expedite the cooling process. Volcanoes evolve steam, carbon dioxide, sulfur dioxide and pyrophosphate. An acidulous Hadean ocean condenses from the carbon dioxide atmosphere. Dusts and stratospheric sulfurous smogs absorb a proportion of the Sun's rays. The cooled ocean leaks into the stressed crust and also convects. High temperature acid springs, coupled to magmatic plumes and spreading centers, emit iron, manganese, zinc, cobalt and nickel ions to the ocean. Away from the spreading centers cooler alkaline spring waters emanate from the ocean floor. These bear hydrogen, formate, ammonia, hydrosulfide and minor methane thiol. The thermal potential begins to be dissipated but the chemical potential is dammed. The exhaling alkaline solutions are frustrated in their further attempt to mix thoroughly with their oceanic source by the spontaneous precipitation of biomorphic barriers of colloidal iron compounds and other minerals. It is here we surmise that organic molecules are synthesized, filtered, concentrated and adsorbed, while acetate and methane-separate products of the precursor to the reductive acetyl-coenzyme-A pathway-are exhaled as waste. Reactions in mineral compartments produce acetate, amino acids, and the components of nucleosides. Short peptides, condensed from the simple amino acids, sequester 'ready-made' iron sulfide clusters to form protoferredoxins, and also bind phosphates. Nucleotides are assembled from amino acids, simple phosphates carbon dioxide and ribose phosphate upon nanocrystalline mineral surfaces. The side chains of particular amino acids register to fitting nucleotide triplet clefts. Keyed in, the amino acids are polymerized, through acid-base catalysis, to alpha chains. Peptides, the tenuous outer-most filaments of the nanocrysts, continually peel away from bound RNA. The polymers are concentrated at cooler regions of the mineral compartments through thermophoresis. RNA is reproduced through a convective polymerase chain reaction operating between 40 and 100 degrees C. The coded peptides produce true ferredoxins, the ubiquitous proteins with the longest evolutionary pedigree. They take over the role of catalyst and electron transfer agent from the iron sulfides. Other iron-nickel sulfide clusters, sequestered now by cysteine residues as CO-dehydrogenase and acetyl-coenzyme-A synthase, promote further chemosynthesis and support the hatchery-the electrochemical reactor-from which they sprang. Reactions and interactions fall into step as further pathways are negotiated. This hydrothermal circuitry offers a continuous supply of material and chemical energy, as well as electricity and proticity at a potential appropriate for the onset of life in the dark, a rapidly emerging kinetic structure born to persist, evolve and generate entropy while the sun shines. C1 CALTECH, Jet Prop Lab, Planetary Sci & Life Detect Sect 3220, Pasadena, CA 91109 USA. RP Russell, MJ (reprint author), CALTECH, Jet Prop Lab, Planetary Sci & Life Detect Sect 3220, MS 183-601,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Michael.J.Russell@jpl.nasa.gov NR 336 TC 51 Z9 52 U1 6 U2 58 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0001-5342 EI 1572-8358 J9 ACTA BIOTHEOR JI Acta Biotheor. PD JUN PY 2007 VL 55 IS 2 BP 133 EP 179 DI 10.1007/s10441-007-9018-5 PG 47 WC Mathematical & Computational Biology SC Mathematical & Computational Biology GA 232HK UT WOS:000251009100003 PM 17704896 ER PT J AU Kuczmarski, MA Johnston, JC AF Kuczmarski, Maria A. Johnston, J. Christopher TI Improved thermal design of a compression mold SO ADVANCES IN POLYMER TECHNOLOGY LA English DT Article DE computer modeling; heat transfer; high-performance polymers; molding; polyimides; processing ID POLYIMIDES AB An analysis of the heat transfer in a tool for producing neat resin disks was conducted to determine how to bring about a better agreement between the tool temperature and the applied temperature profile. Using the commercial code FLUENT to investigate the relative effects of heat conduction into the tool and heat loss from the tool by convection, it was shown that convective heat transfer appears more important than conduction in controlling the tool performance. Decreasing the height of the tool was predicted to decrease the heat losses by convection. Redesigning of the tool based on this analysis resulted in the tool experiencing the applied temperature profile. (C) 2007 Wiley Periodicals, Inc. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Kuczmarski, MA (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM Maria.A.Kuczmarski@nasa.gov NR 8 TC 1 Z9 1 U1 1 U2 3 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0730-6679 J9 ADV POLYM TECH JI Adv. Polym. Technol. PD SUM PY 2007 VL 26 IS 2 BP 86 EP 99 DI 10.1002/adv.20091 PG 14 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 217RO UT WOS:000249965200002 ER PT J AU Bresina, JL Morris, PH AF Bresina, John L. Morris, Paul H. TI Mixed-initiative planning in space mission operations SO AI MAGAZINE LA English DT Article AB The MAPGEN system represents a successful mission infusion of mixed-initiative planning technology. MAPGEN was deployed as a mission-critical component of the ground operations system for the Mars Exploration Rover mission. Each day, the ground-planning personnel employ MAPGEN to collaboratively plan the activities of the Spirit and Opportunity rovers, with the objective of achieving as much science as possible while ensuring rover safety and keeping within the limitations of. the rovers' resources. The Mars Exploration Rover mission has now been operating for more than two years, and MAPGEN continues to be employed for activity plan generation for the Spirit and Opportunity rovers. During the multiyear deployment effort and subsequent mission operations experience, we have learned valuable lessons regarding application of mixed-initiative planning technology to mission operations. These lessons have spawned new research in mixed-initiative planning and have influenced the design of a new ground operations system, called M-SLICE, that is baselined for the Mars Science Laboratory mission. In this article, we discuss the mixed-initiative aspects of the MAPGEN system, focusing on the task, control, and awareness issues. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bresina, JL (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 15 TC 7 Z9 7 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 2007 VL 28 IS 2 BP 75 EP 88 PG 14 WC Computer Science, Artificial Intelligence SC Computer Science GA 183PH UT WOS:000247584200009 ER PT J AU Doty, MJ Henderson, BS Kinzie, KW AF Doty, Michael J. Henderson, Brenda S. Kinzie, Kevin W. TI Turbulence measurements of separate-flow nozzles with pylon interaction using particle image velocimetry SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA/CEAS 10th Aeroacoustics Conference CY MAY 10-12, 2004 CL Manchester, ENGLAND SP AIAA, CEAS AB Particle image velocimetry measurements for separate-flow nozzles with bypass ratio five have recently been obtained in the NASA Langley Jet Noise Laboratory. The six configurations tested include a baseline configuration with round core and fan nozzles, an eight-chevron core nozzle at two different clocking positions, and repeats of these configurations with a pylon included. One run condition representative of takeoff was investigated for all cases. The unsteady flowfield measurements complement recent computational, acoustic, and mean flowfield studies performed at NASA Langley for the same nozzle configurations and run condition. The baseline configuration measurements show good agreement with existing mean and turbulent flowfield data. Nonetheless, the baseline configuration turbulence profile indicates an asymmetric flowfield, despite careful attention to concentricity. The presence of the pylon increases the upper shear layer turbulence levels while simultaneously decreasing the turbulence levels in the lower shear layer. In addition, a slightly shorter potential core length is observed with the addition of the pylon. Finally, comparisons of computational results with current measurements are favorable for mean flow, slightly overpredicted for Reynolds shear stress, and underpredicted for Reynolds normal stress components. C1 NASA, Langley Res Ctr, Aeroacoust Branch, Hampton, VA 23681 USA. RP Doty, MJ (reprint author), Rolls Royce PLC, Indianapolis, IN 46206 USA. NR 15 TC 3 Z9 3 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD JUN PY 2007 VL 45 IS 6 BP 1281 EP 1289 DI 10.2514/1.20420 PG 9 WC Engineering, Aerospace SC Engineering GA 175CK UT WOS:000246990000013 ER PT J AU Nguyen, NT Bright, MM Culley, D AF Nguyen, Nhan T. Bright, Michelle M. Culley, Dennis TI Adaptive feedback optimal control of flow separation on stators by air injection SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA Guidance, Navigation and Control Conference CY AUG 15-18, 2005 CL San Francisco, CA SP AIAA ID EQUATIONS AB This paper presents an adaptive flow control approach for controlling flow separation in a stator cascade within a low-speed axial-flow compressor using an air injection technique. Flow separation usually manifests itself as an increase in a total pressure loss across a blade row. A 1-D unsteady How model based on the Euler equations incorporating a pressure loss parameter is used to design a feedback control of the total pressure at the outlet. The feedback adaptive control strategy relies on a recursive least-square parameter estimation to estimate the effectiveness of air injection. A nonlinear trajectory optimization is developed to determine an optimal air injection gain schedule. Disturbances due to variations in the inlet flow condition at the stator blade row are minimized by a quasi-steady state error-correction feedback optimal control to maintain a desired air injection value. The nonlinear optimization and quasi-steady state feedback optimal control are recently developed based on an adjoint method for the Euler equations. A numerical simulation demonstrates the effectiveness of the proposed flow control strategy. C1 NASA, Ames Res Ctr, Intelligent Syst Div, Moffett Field, CA 94035 USA. NASA, Glenn Res Ctr, Control & Dynam Technol Branch, Cleveland, OH 44135 USA. RP Nguyen, NT (reprint author), NASA, Ames Res Ctr, Intelligent Syst Div, Mail Stop 269-1, Moffett Field, CA 94035 USA. NR 18 TC 2 Z9 2 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD JUN PY 2007 VL 45 IS 6 BP 1393 EP 1405 DI 10.2514/1..18226 PG 13 WC Engineering, Aerospace SC Engineering GA 175CK UT WOS:000246990000023 ER PT J AU Xiao, X Hassan, HA Baurle, RA AF Xiao, X. Hassan, H. A. Baurle, R. A. TI Modeling scramjet flows with variable turbulent Prandtl and Schmidt numbers SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 44th Aerospace Sciences Meeting and Exhibit CY JAN 09-12, 2006 CL Reno, NV SP AIAA AB A complete turbulence model is presented in which the turbulent Prandtl and Schmidt numbers are calculated as part of the solution and in which averages involving chemical source terms are modeled. The model avoids the use of assumed or evolution probability distribution functions and thus results in a highly efficient algorithm for reacting flows. The predictions from the model are compared with two sets of experiments involving supersonic mixing and one involving supersonic combustion. Two sets of H-2/air chemical kinetic mechanisms are considered: one involving 7 species and 7 reactions, the other involving 9 species and 19 reactions, with reaction rates being dependent on both pressure and temperature. The results demonstrate the need for consideration of turbulence/chemistry interactions in supersonic combustion. In general, good agreement with the experiment is indicated. C1 N Carolina State Univ, Raleigh, NC 27695 USA. NASA, Langley Res Ctr, Hyperson Airbreathing Prop Branch, Hampton, VA 23681 USA. RP Xiao, X (reprint author), N Carolina State Univ, Raleigh, NC 27695 USA. NR 16 TC 9 Z9 9 U1 0 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD JUN PY 2007 VL 45 IS 6 BP 1415 EP 1423 DI 10.2514/1.26382 PG 9 WC Engineering, Aerospace SC Engineering GA 175CK UT WOS:000246990000025 ER PT J AU Tiwari, VS Kalluru, RR Yueh, FY Singh, JP St Cyr, W Khijwania, SK AF Tiwari, Vidhu S. Kalluru, Rajamohan R. Yueh, Fang Y. Singh, Jagdish P. St. Cyr, William Khijwania, Sunil K. TI Fiber optic Raman sensor to monitor the concentration ratio of nitrogen and oxygen in a cryogenic mixture SO APPLIED OPTICS LA English DT Article AB A spontaneous Raman scattering optical fiber sensor was developed for a specific need of the National Aeronautics and Space Administration (NASA) for long-term detection and monitoring of the purity of liquid oxygen (LO2) in the oxidizer feed line during ground testing of rocket engines. The Raman peak intensity ratios for liquid nitrogen (LN2) and LO2 with varied weight ratios (LN2/LO2) were analyzed for their applicability to impurity sensing. The study of the sensor performance with different excitation light sources has helped to design a miniaturized, cost-effective system for this application. The optimal system response time of this miniaturized sensor for LN2/LO2 measurement was found to be in the range of a few seconds. It will need to be further reduced to the millisecond range for real-time, quantitative monitoring of the quality of cryogenic fluids in a harsh envioronment. (c) 2007 Optical Society of America. C1 Mississippi State Univ, Inst Clean Energy Technol, Starkville, MS 39759 USA. Mississippi Ethanol LLC, Winona, MS 38968 USA. NASA, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Indian Inst Technol, Dept Phys, Gauhati 781039, Assam, India. RP Singh, JP (reprint author), Mississippi State Univ, Inst Clean Energy Technol, 205 Res Blvd, Starkville, MS 39759 USA. EM singh@ICET.msstate.edu RI Tiwari, Vidhu /J-9109-2016 NR 10 TC 5 Z9 5 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD JUN 1 PY 2007 VL 46 IS 16 BP 3345 EP 3351 DI 10.1364/AO.46.003345 PG 7 WC Optics SC Optics GA 172IR UT WOS:000246798000036 PM 17514292 ER PT J AU Jalbout, AF Abrell, L Adamowicz, L Polt, R Apponi, AJ Ziurys, LM AF Jalbout, Abraham F. Abrell, Leif Adamowicz, Ludwik Polt, Robin Apponi, A. J. Ziurys, L. M. TI Sugar synthesis from a gas-phase formose reaction SO ASTROBIOLOGY LA English DT Article DE astrobiology; molecular processes; laboratory methods; interstellar medium, molecules; interstellar medium, clouds ID INTERSTELLAR-MOLECULES; GLYCOLALDEHYDE; FORMALDEHYDE; MODEL; LIFE; ION AB Prebiotic possibilities for the synthesis of interstellar ribose through a protic variant of the formose reaction under gas-phase conditions were studied in the absence of any known catalyst. The ion-molecule reaction products, those and triose, were sought by mass spectrometry, and relevant masses were observed. Ab initio calculations were used to evaluate protic formose mechanism possibilities. A bilateral theoretical and experimental effort yielded a physical model for glycoaldehyde generation whereby a hydronium cation can mediate formaldehyde dimerization followed by covalent bond formation leading to those and water. These results advance the possibility that ion-molecule reactions between formaldehyde (CH2O) and H3O+ lead to formose reaction products and inform us about potential sugar formation processes in interstellar space. C1 Univ Nacl Autonoma Mexico, Dept Phys Chem, Inst Chem, Mexico City 04510, DF, Mexico. Univ Arizona, Steward Observ, Tucson, AZ USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Univ Arizona, Dept Astron, Tucson, AZ USA. Univ Arizona, NASA, Astrobiol Inst, Tucson, AZ USA. RP Jalbout, AF (reprint author), Univ Nacl Autonoma Mexico, Dept Phys Chem, Inst Chem, Col Coyoacan, Mexico City 04510, DF, Mexico. EM ajalbout@u.arizona.edu RI Polt, Robin/E-2339-2017; OI Polt, Robin/0000-0003-0756-3183; Abrell, Leif/0000-0003-2490-1180 NR 25 TC 20 Z9 20 U1 1 U2 18 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 2007 VL 7 IS 3 BP 433 EP 442 DI 10.1089/ast.2006.0083 PG 10 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900001 PM 17630839 ER PT J AU Apai, D AF Apai, Daniel TI Planets around the coolest stars in the universe SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Arizona, NASA, Astrobiol Inst, Steward Observ, Tucson, AZ 85721 USA. EM apai@as.arizona.edu NR 0 TC 0 Z9 0 U1 0 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O4 BP 477 EP 477 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900009 ER PT J AU Bonev, BP Mumma, MJ Gibb, EL DiSanti, MA Villanueva, GL Magee-Sauer, K AF Bonev, Boncho P. Mumma, Michael J. Gibb, Erika L. DiSanti, Michael A. Villanueva, Geronimo L. Magee-Sauer, Karen TI Ground-based infrared observations of cometary water - Cosmogonic and astrobiological implications SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Catholic Univ Amer, Goddard Ctr Astrobiol, NASA GSFC, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Goddard Ctr Astrobiol, Greenbelt, MD 20771 USA. Univ Missouri, Goddard Ctr Astrobiol, Dept Phys & Astron, St Louis, MO 63121 USA. EM bbonev@ssedmail.gsfc.nasa.gov RI mumma, michael/I-2764-2013; Magee-Sauer, Karen/K-6061-2015 OI Magee-Sauer, Karen/0000-0002-4979-9875 NR 0 TC 0 Z9 0 U1 0 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O6 BP 477 EP 478 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900011 ER PT J AU Cabrol, NA Minkley, EG Yu, Y Grin, EA Woosley, C Morris, R AF Cabrol, Nathalie A. Minkley, Edwin G., Jr. Yu, Youngseob Grin, Edmond A. Woosley, Clayton Morris, Robert TI Unraveling life's diversity in Earth's highest volcanic lake SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, SETI, CSC, Moffett Field, CA 94035 USA. Carnegie Mellon Univ, Dept Civil & Environm Engn, Dept Biol Sci, Pittsburgh, PA 15213 USA. EM ncabrol@mail.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA O8 BP 478 EP 478 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900013 ER PT J AU Beegle, LW Wilson, MG Schmidt, TJ Wilson, GR AF Beegle, Luther W. Wilson, Michael G. Schmidt, Troy J. Wilson, Gregory R. TI Current concept for NASA's 2016 astrobiology field laboratory SO ASTROBIOLOGY LA English DT Meeting Abstract C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. EM Luther.Beegle@jpl.nasa.gov RI Beegle, Luther/A-6354-2010 NR 0 TC 0 Z9 0 U1 0 U2 4 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O11 BP 479 EP 479 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900016 ER PT J AU Charnley, S AF Charnley, Steven TI Theoretical models of complex molecule formation on dust SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Moffett Field, CA 94035 USA. EM charnley@dusty.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA O10 BP 479 EP 479 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900015 ER PT J AU Conley, CA AF Conley, Catharine A. TI Life, gravity, and everything SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM Cassie.Conley@nasa.gov NR 0 TC 0 Z9 0 U1 1 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O12 BP 479 EP 479 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900017 ER PT J AU Cruikshank, DP AF Cruikshank, Dale P. TI Organic matter in the solar system: Meteorites, comets, planetary satellites, and Kuiper Belt objects SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM Dale.P.Cruikshank@nasa.gov NR 0 TC 0 Z9 0 U1 1 U2 4 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O13 BP 480 EP 480 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900018 ER PT J AU Marais, DJD AF Marais, David J. Des TI Mars exploration Rovers and water SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Astrobiol Inst, Athena Sci Team, Moffett Field, CA 94035 USA. EM David.J.DesMarais@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA O16 BP 481 EP 481 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900021 ER PT J AU Haghighipour, N AF Haghighipour, Nader TI Extreme habitability: Formation of habitable planets in systems with close-in giant planets and/or stellar companions SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Hawaii Manoa, NASA, Astrobiol Inst, Inst Astron, Honolulu, HI 96822 USA. EM nader@ifa.hawaii.edu NR 0 TC 0 Z9 0 U1 0 U2 1 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 2007 VL 7 IS 3 MA O25 BP 483 EP 484 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900030 ER PT J AU Hudson, RL Moore, MH Dworkin, JP Martin, MP AF Hudson, Reggie L. Moore, Marla H. Dworkin, Jason P. Martin, Mildred P. TI Enigmatic isovaline: Investigating the stability, racemization, and formation of a nonbiological meteoritic amino acid SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Eckerd Coll, Astrobiol Inst, NASA, Goddard Ctr Astrobiol, St Petersburg, FL 33711 USA. Eckerd Coll, Astrobiol Inst, NASA, Dept Chem, St Petersburg, FL USA. NASA, Astrobiol Inst, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM hudsonrl@eckerd.edu RI Hudson, Reggie/E-2335-2012; Dworkin, Jason/C-9417-2012 OI Dworkin, Jason/0000-0002-3961-8997 NR 0 TC 0 Z9 0 U1 0 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O29 BP 485 EP 485 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900034 ER PT J AU Khare, BN McKay, CP Sekine, Y Wilhite, P Cruikshank, DP Ishihara, T AF Khare, Bishun N. McKay, Christopher P. Sekine, Yasuhito Wilhite, Patrick Cruikshank, Dale P. Ishihara, Tomoko TI Do tholins act in maintaining the mixing ratio of methane in the atmosphere of titan? SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Tokyo, Japan. Santa Clara Univ, Ctr Nanostruct, Sch Engn, Santa Clara, CA 95053 USA. Santa Clara Univ, NASA, Ames Res Ctr, Div Space Sci, Santa Clara, CA 95053 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA USA. EM bkhare@mail.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA O33 BP 486 EP 486 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900038 ER PT J AU Kiang, NY Segura, A Tinetti, G Govindjee Blankenship, RE Cohen, M Siefert, J Crisp, D Meadows, VS AF Kiang, Nancy Y. Segura, Antigona Tinetti, Giovanna Govindjee Blankenship, Robert E. Cohen, Martin Siefert, Janet Crisp, David Meadows, Victoria S. TI Spectral signatures of photosynthesis: Coevolution with other stars and the atmosphere on extrasolar worlds SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Nacl Autonoma Mexico, NASA, Goddard Inst Space Studies, Mexico City 04510, DF, Mexico. Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico. Univ Illinois, Inst Astrophys Paris, European Space Agcy, Urbana, IL USA. Univ Illinois, Dept Plant Biol, Urbana, IL 61801 USA. Washington Univ, Dept Biol & Chem, St Louis, MO 63130 USA. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. Rice Univ, Dept Stat, Houston, TX 77251 USA. CALTECH, NASA, Jet Propuls Lab, Pasadena, CA 91125 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. EM nkiang@giss.nasa.gov NR 0 TC 2 Z9 2 U1 0 U2 8 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 2007 VL 7 IS 3 MA O34 BP 486 EP 487 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900039 ER PT J AU Leuko, S Walter, MR Rogoff, D Rothschild, LJ Neilan, BA AF Leuko, Stefan Walter, Malcolm R. Rogoff, D. Rothschild, L. J. Neilan, B. A. TI Modern stromatolites: What can they tell us about the evolution of life? SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Macquarie Univ, Australian Ctr Astrobiol, N Ryde, NSW, Australia. NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. Univ New S Wales, Cyanobacteria & Astrobiol Res Lab, Kensington, NSW 2033, Australia. EM sleuko@bio.mq.edu.au NR 0 TC 0 Z9 0 U1 0 U2 7 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 2007 VL 7 IS 3 MA O40 BP 489 EP 489 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900045 ER PT J AU Mandell, AM Sigurdsson, S Mumma, MJ Bonev, B Villanueva, G Blake, GA AF Mandell, Avi M. Sigurdsson, Steinn Mumma, Michael J. Bonev, Boncho Villanueva, Geronimo Blake, Geoffrey A. TI First detection of warm OH in the planet-forming regions of gas-rich circumstellar disks SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Penn State Univ, Goddard Space Flight Ctr, Goddard Ctr Astrobiol, Dept Astron & Astrophys, University Pk, PA 16802 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. CALTECH, Div Chem & Chem Engn, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. EM Avi.Mandell@gsfc.nasa.gov RI mumma, michael/I-2764-2013 NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA O42 BP 489 EP 490 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900047 ER PT J AU Ohmoto, H Watanabe, Y AF Ohmoto, Hiroshi Watanabe, Yumiko TI Geochemical evidence for the early development of modern-styled ecosystems and an oxygenated atmosphere SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Penn State Univ, NASA, Astrobiol Inst, Dept Geosci, University Pk, PA 16802 USA. EM ohmoto@geosc.psu.edu NR 0 TC 0 Z9 0 U1 3 U2 9 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O48 BP 492 EP 492 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900053 ER PT J AU Pasek, MA AF Pasek, Matthew A. TI Rethinking early Earth phosphorus geochemistry SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Arizona, NASA, Astrobiol Inst, Tucson, AZ 85721 USA. EM mpasek@lpl.arizona.edu NR 0 TC 0 Z9 0 U1 0 U2 4 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O49 BP 492 EP 492 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900054 ER PT J AU Pohorille, A Wilson, MA Wei, CY AF Pohorille, Andrew Wilson, Michael A. Wei, Chenyu TI The earliest ion channels SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA USA. EM pohorill@max.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA O50 BP 492 EP 493 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900055 ER PT J AU Sandford, SA AF Sandford, Scott A. TI Organics in the samples returned by the Stardust spacecraft from Comet 81P/Wild 2 SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Div Space Sci, Astrophys Branch, Ames, IA USA. EM ssandford@mail.arc.nasa.gov NR 0 TC 1 Z9 1 U1 0 U2 4 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O-53 BP 493 EP 494 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900058 ER PT J AU Villanueva, GL Mumma, MJ Novak, RE Hewagama, T Bonev, BP DiSanti, MA AF Villanueva, Geronimo L. Mumma, Michael J. Novak, Robert E. Hewagama, Tilak Bonev, Boncho P. DiSanti, Michael A. TI A sensitive search for life signatures in the martian atmosphere SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM villanueva@ssedmail.gsfc.nasa.gov RI Hewagama, T/C-8488-2012; mumma, michael/I-2764-2013 NR 0 TC 0 Z9 0 U1 0 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O-64 BP 497 EP 497 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900069 ER PT J AU Cowen, JP Glazer, BT Rappe, M Amend, J Giovannoni, S Kenig, F AF Cowen, James P. Glazer, Brian T. Rappe, Michael Amend, Jan Giovannoni, Stephen Kenig, Fabien TI Microbial ecology of deep subsurface ocean basement fluids: ODP borehole observatories SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Hawaii, NASA, Astrobiol Inst, Honolulu, HI 96822 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Oregon State Univ, Dept Microbiol, Corvallis, OR 97331 USA. Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60680 USA. EM jcowen@soest.hawaii.edu NR 0 TC 0 Z9 0 U1 0 U2 4 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O-71 BP 499 EP 500 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900076 ER PT J AU Gary, T Butler, J de la Rubia, LA Kirven-Brooks, M Ceballos, M Taylor, L Bell, B Coulter, G AF Gary, Todd Butler, Judy de la Rubia, Leigh Arino Kirven-Brooks, Melissa Ceballos, Michael Taylor, LaTasha Bell, Benita Coulter, Gary TI The NASA astrobiology Institute - Minority Institution Research Support Program: Strengthening the astrobiology community SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Tennessee State Univ, Inst Understanding Biol Syst, Johnson City, TN 37614 USA. NASA Ames Res Ctr, NASA Astrobiol Inst, Ames, IA USA. Univ Washington, Astrobiol Program, Seattle, WA 98195 USA. NASA Goddard Space Flight Ctr, Minority Univ Space Interdisciplinary Network, Greenbelt, MD USA. Challenger Learning Ctr, Colorado Springs, CO USA. EM tgary@coe.tsuniv.edu NR 0 TC 0 Z9 0 U1 1 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA O-70 BP 499 EP 499 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900075 ER PT J AU Glavin, DP Dworkin, JP Sandford, SA AF Glavin, Daniel P. Dworkin, Jason P. Sandford, Scott A. TI A search for cometary amines in samples returned by Stardust SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Goddard Space Flight Ctr, Goddard Ctr Astrbiol, Greenbelt, MD USA. NASA, Ames Res Ctr, Astrochem Lab, Ames, IA USA. EM daniel.p.glavin@nasa.gov RI Glavin, Daniel/D-6194-2012; Dworkin, Jason/C-9417-2012 OI Glavin, Daniel/0000-0001-7779-7765; Dworkin, Jason/0000-0002-3961-8997 NR 0 TC 0 Z9 0 U1 0 U2 6 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 2007 VL 7 IS 3 MA O-73 BP 500 EP 500 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900078 ER PT J AU de la Rubia, LA Butler, J Stockman, S Gary, T Mumma, M Pfiffner, S Davis, K Edmonds, J AF de la Rubia, Leigh Arino Butler, Judy Stockman, Stephanie Gary, Todd Mumma, Michael Pfiffner, Susan Davis, Kimberly Edmonds, Julie TI Development, evaluation, and dissemination of an astrobiology curriculum for secondary students: Establishing a successful model for increasing the use of scientific data by underrepresented students SO ASTROBIOLOGY LA English DT Meeting Abstract C1 E Tennessee State Univ, Inst Understanding Biol Sci, Johnson City, TN 37614 USA. Tennessee State Univ, Inst Understanding Biol Syst, Johnson City, TN 37614 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD USA. Univ Tennessee, Ctr Biomarker Anal, Knoxville, TN 37996 USA. Univ Tennessee, Inst Secure & Sustainable Environm, Knoxville, TN 37996 USA. Carnegie Inst Washington, Washington, DC 20005 USA. EM Leigh.Arinodelarubia@gmail.com RI mumma, michael/I-2764-2013 NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA O-2 BP 502 EP 503 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900084 ER PT J AU Peters, G Mungas, GS Bearman, GH Smith, JA Anderson, RC Beegle, LW Sun, H AF Peters, Gregory Mungas, Gregory S. Bearman, Gregory H. Smith, J. Anthony Anderson, Robert C. Beegle, Luther W. Sun, Henry TI Science investigations using a rapid active sampling package (RASP) SO ASTROBIOLOGY LA English DT Meeting Abstract C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RI Beegle, Luther/A-6354-2010 NR 0 TC 0 Z9 0 U1 0 U2 5 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 2007 VL 7 IS 3 MA P-5 BP 503 EP 504 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900087 ER PT J AU Bonaccorsi, R Stoker, C AF Bonaccorsi, Rosalba Stoker, Carol TI Searching for organics under a simulated Mars robotic drilling mission (Rio Tinto, Spain): What lies underground? SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Ames, IA USA. EM rbonaccorsi@mail.arc.nasa.gov NR 7 TC 0 Z9 0 U1 0 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA P-9 BP 504 EP 505 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900091 ER PT J AU Kisiel, Z Pszczokowski, L Biakowska-Jaworska, E Charnley, S AF Kisiel, Zbigniew Pszczokowski, Lech Biakowska-Jaworska, Ewa Charnley, Steven TI The millimeter wave spectrum of pyruvic acid SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Polish Acad Sci, Inst Phys, Warsaw, Poland. NASA, Ames Res Ctr, Space Sci & Astrbiol Div, Ames, IA USA. EM sbcharnley@comcast.net RI Kisiel, Zbigniew/K-8798-2016; Bialkowska-Jaworska, Ewa/R-9282-2016 OI Kisiel, Zbigniew/0000-0002-2570-3154; NR 0 TC 0 Z9 0 U1 0 U2 5 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 2007 VL 7 IS 3 MA P-14 BP 506 EP 506 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900096 ER PT J AU Cooper, CS Pavlov, AA AF Cooper, Curtis S. Pavlov, Alexander A. TI A new twist on planetary habitability SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Arizona, NASA, Astrobiol Inst, Tucson, AZ 85721 USA. EM curtis@lpl.arizona.edu NR 0 TC 0 Z9 0 U1 0 U2 4 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA P-16 BP 507 EP 507 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900098 ER PT J AU DiSanti, MA Mumma, MJ Bonev, BP Villanueva, GL Anderson, WM AF DiSanti, Michael A. Mumma, Michael J. Bonev, Boncho P. Villanueva, Geronimo L. Anderson, William M. TI The interesting volatile organic composition of comet C/2006 M4 (SWAN) SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Goddard Space Flight Ctr, Goddard Ctr Astrobiol, NASA, Greenbelt, MD USA. EM disanti@ssedmail.gsfc.nasa.gov RI mumma, michael/I-2764-2013 NR 0 TC 0 Z9 0 U1 0 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA P-25 BP 510 EP 510 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900107 ER PT J AU Harrington, DM Meech, KJ Kolokolova, L Kuhn, JR Whitman, K AF Harrington, David M. Meech, Karen J. Kolokolova, Ludmilla Kuhn, Jeff R. Whitman, Kathryn TI Spectropolarimetry of the deep impact comet 9P/tempel 1 SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Hawaii, NASA, Astrobiol Inst, Astron Inst, Honolulu, HI 96822 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Univ Hawaii, Astron Inst, Honolulu, HI 96822 USA. EM dmh@ifa.hawaii.edu NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA P-41 BP 515 EP 515 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900123 ER PT J AU Lazio, J Farrell, WM Clark, JW Elkins, E Gudmundsen, P Hennig, LA AF Lazio, Joseph Farrell, W. M. Clark, J. W. Elkins, Edward Gudmundsen, Peter Hennig, L. A. TI Searching for planets around "adolescent" stars SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Lazio@nrl.navy.mil RI Farrell, William/I-4865-2013 NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA P-54 BP 519 EP 520 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900136 ER PT J AU Nna-Mvondo, D Khare, BN Ishihara, T Mckay, CP AF Nna-Mvondo, Delphine Khare, Bishun N. Ishihara, Tomoko Mckay, Christopher P. TI Chemical production by pulse-laser irradiation on ices: Simulation of impact shock-induced chemistry on icy satellites SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Ctr Astrobiol CAB, Inst Nacl Tecnica Aeroespacial, Madrid, Spain. NASA, Ames Res Ctr, SETI Inst, Space Sci Div, Moffett Field, CA 94035 USA. EM nnamvondod@inta.es NR 0 TC 0 Z9 0 U1 0 U2 9 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA P-72 BP 525 EP 525 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900154 ER PT J AU Stockstill, KR Anderson, FS Hamilton, VE AF Stockstill, Karen R. Anderson, F. Scott Hamilton, Victoria E. TI Mapping the regional extent of sulfate-rich layers on mars using THEMIS thermal inertia SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Hawaii Manoa, Hawaii Inst Geophys & Planetol, NASA, Astrobiol Inst, Honolulu, HI 96822 USA. EM kstockst@higp.hawaii.edu NR 0 TC 1 Z9 1 U1 0 U2 2 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 2007 VL 7 IS 3 MA P-87 BP 530 EP 530 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900169 ER PT J AU ten Kate, IL Mahaffy, PR AF ten Kate, Inge L. Mahaffy, Paul R. TI Laboratory simulations on discharge in the Martian atmosphere SO ASTROBIOLOGY LA English DT Meeting Abstract C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM ingeloes.tenkate@ssedmail.gsfc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA P-89 BP 531 EP 531 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900171 ER PT J AU Tsapin, A Abbey, W AF Tsapin, Alexandre Abbey, William TI Application of X-ray tomography for life detection inside rocks blueberries SO ASTROBIOLOGY LA English DT Meeting Abstract C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. EM tsapin@jpl.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA P-91 BP 531 EP 531 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900173 ER PT J AU Wang, KS Kuan, YJ Huang, HC Charnley, S AF Wang, Kuo-Song Kuan, Yi-Jehng Huang, Hui-Chun Charnley, Steven TI Organic molecules in the orion KL hot molecular core SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Natl Taiwan Univ, Taipei 10764, Taiwan. Natl Taiwan Normal Univ, Dept Earth Sci, Taipei, Taiwan. Acad Sinica, Inst Astron & Astrophys, Taipei 115, Taiwan. NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Ames, IA USA. EM kswang@asiaa.sinica.edu.tw NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA P-95 BP 533 EP 533 PG 1 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900177 ER PT J AU Zheng, WJ Jewitt, D Kaiser, RI AF Zheng, Weijun Jewitt, David Kaiser, Ralf I. TI Laboratory studies of solid water and ammonia hydrate relevant to outer solar system ices SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Hawaii Manoa, Inst Astron, NASA, Astrobiol Inst,Dept Chem, Honolulu, HI 96822 USA. Univ Hawaii Manoa, Inst Astron, Honolulu, HI 96822 USA. Univ Hawaii Manoa, Dept Chem, Honolulu, HI 96822 USA. EM zhengw@hawaii.edu NR 0 TC 0 Z9 0 U1 0 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA P-101 BP 534 EP 535 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900183 ER PT J AU Czaja, AD Kudryavtsev, AB AF Czaja, Andrew D. Kudryavtsev, Anatoliy B. TI Fine-scale analysis of permineralized fossil kerogen SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Calif Los Angeles, Ctr Study Evolut & Origin Life, Inst Geophys & Planetary Phys, Dept Earth & Space Sci, Los Angeles, CA USA. Univ Calif Los Angeles, Ctr Study Evolut & Origin Life, Inst Geophys & Planetary Phys, Los Angeles, CA USA. Univ Calif Los Angeles, Ctr Astrobiol, Astrobiol Inst, NASA, Los Angeles, CA USA. EM aczaja@ess.ucla.edu NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA P-105 BP 535 EP 536 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900187 ER PT J AU Matrajt, G Ito, M Messenger, S Wirick, S Brownlee, D Joswiak, D Flynn, G Sandford, S AF Matrajt, Graciela Ito, Motoo Messenger, Scott Wirick, Sue Brownlee, Don Joswiak, Dave Flynn, George Sandford, Scott TI Carbon investigation of stardust particles: A TEM, NanoSIMS, and XANES study SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Washington, Dept Astron, Seattle, WA 98195 USA. SUNY Stony Brook, Dept Phys & Astron, New York, NY USA. SUNY Coll Plattsburgh, Dept Phys, Plattsburgh, NY 12901 USA. Ames Res Ctr, NASA, Astrophys Branch, Ames, IA USA. EM matrajt@astro.washington.edu NR 0 TC 0 Z9 0 U1 0 U2 3 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD JUN PY 2007 VL 7 IS 3 MA P-108 BP 537 EP 538 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900190 ER PT J AU Rojo, PM Harrington, J Deming, D Fortney, J AF Rojo, Patricio M. Harrington, Joseph Deming, Drake Fortney, Jonathan TI Transit spectroscopy of the extrasolar planet HD 209458b: The search for water SO ASTROBIOLOGY LA English DT Meeting Abstract C1 Univ Chile, Dept Astron, Santiago, 32816, Chile. Cornell Univ, Dept Astron, Santiago, Chile. Univ Cent Florida, Dept Phys, Orlando, FL USA. NASA, Ames Res Ctr, Ames, IA USA. EM pato@das.uchile.cl RI Harrington, Joseph/E-6250-2011; Rojo, Patricio/K-6732-2012; Rojo, Patricio/I-5765-2016 OI Rojo, Patricio/0000-0002-1607-6443; NR 0 TC 0 Z9 0 U1 0 U2 2 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 2007 VL 7 IS 3 MA P-112 BP 538 EP 539 PG 2 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 191YC UT WOS:000248166900194 ER PT J AU Reuland, M Van Breugel, W De Vries, W Dopita, MA Dey, A Miley, G Rottgering, H Venemans, B Stanford, SA Lacy, M Spinrad, H Dawson, S Stern, D Bunker, A AF Reuland, Michiel Van Breugel, Wil De Vries, Wim Dopita, Michael A. Dey, Arjun Miley, George Rottgering, Huub Venemans, Bram Stanford, S. A. Lacy, Mark Spinrad, Hy Dawson, Steve Stern, Daniel Bunker, Andrew TI Metal-enriched gaseous halos around distant radio galaxies: Clues to feedback in galaxy formation SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : formation; galaxies : high-redshift; galaxies : individual (B2 0902+34, 4C 60.07, 4C 41.17); quasars : emission lines ID EMISSION-LINE GAS; PRESSURE-DOMINATED PHOTOIONIZATION; LYMAN-ALPHA EMISSION; HIGH-REDSHIFT; STAR-FORMATION; 4C 41.17; INFRARED-SPECTROSCOPY; DEEP SPECTROSCOPY; LY-ALPHA; ECHELLE SPECTROGRAPH AB We present the results of an optical and near-IR spectroscopic study of giant nebular emission-line halos associated with three z > 3 radio galaxies, 4C 41.17, 4C 60.07, and B2 0902+34. Previous deep narrowband Ly alpha imaging revealed complex morphologies with sizes up to 100 kpc, possibly connected to outflows and AGN feedback from the central regions. The outer regions of these halos show quiet kinematics with typical velocity dispersions of a few hundred km s(-1) and velocity shears that can mostly be interpreted as being due to rotation. The inner regions show shocked cocoons of gas closely associated with the radio lobes. These display disturbed kinematics and have expansion velocities and/or velocity dispersions > 1000 km s(-1). The core region is chemically evolved, and we also find spectroscopic evidence for the ejection of enriched material in 4C 41.17 up to a distance of approximate to 60 kpc along the radio axis. The dynamical structures traced in the Ly alpha line are, in most cases, closely echoed in the carbon and oxygen lines. This shows that the Ly alpha line is produced in a highly clumped medium of small filling factor and can therefore be used as a tracer of the dynamics of high-redshift radio galaxies ( HzRGs). We conclude that these HzRGs are undergoing a final jet-induced phase of star formation with ejection of most of their interstellar medium before becoming "red and dead'' elliptical galaxies. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands. Univ Calif, Merced, CA 95344 USA. Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Natl Opt Astron Observ, Tucson, AZ 85719 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. RP Reuland, M (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. EM wil@igpp.ucllnl.org RI Dopita, Michael/P-5413-2014 OI Dopita, Michael/0000-0003-0922-4986 NR 84 TC 28 Z9 28 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 2007 VL 133 IS 6 BP 2607 EP 2623 DI 10.1086/516571 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 175BO UT WOS:000246987400014 ER PT J AU Hedman, MM Nicholson, PD Salo, H Wallis, BD Buratti, BJ Baines, KH Brown, RH Clark, RN AF Hedman, Matthew M. Nicholson, Philip D. Salo, Heikki Wallis, Bradford D. Buratti, Bonnie J. Baines, Kevin H. Brown, Robert H. Clark, Roger N. TI Self-gravity wake structures in Saturn's a ring revealed by Cassini vims SO ASTRONOMICAL JOURNAL LA English DT Article DE planets : rings ID VOYAGER OBSERVATIONS; STELLAR OCCULTATION; DISPERSION; GAP AB During the summer of 2005, the Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft observed a series of occultations of the star o Ceti ( Mira) by Saturn's rings. These observations revealed pronounced variations in the optical depth of the A ring with longitude, which can be attributed to oriented structures in the rings known as self-gravity wakes. While the wakes themselves are only tens of meters across and below the resolution of the measurements, we are able to obtain information about the orientation and shapes of these structures by comparing the observed transmission at different longitudes with predictions from a simple model. Our findings include the following: ( 1) The orientation of the wakes varies systematically with radius, trailing by between 64 degrees and 72 degrees relative to the local radial direction. ( 2) The maximum transmission peaks at roughly 8% for B = 3.45 degrees in the middle A ring ( similar to 129,000 km). ( 3) Both the wake orientation and maximum transmission vary anomalously in the vicinity of two strong density waves ( Janus 5: 4 and Mimas 5: 3). ( 4) The ratio of the wake vertical thickness H to the wake pattern wavelength lambda ( assuming infinite, straight, regularly-spaced wake structures) varies from 0.12 to 0.09 across the A ring. Gravitational instability theory predicts lambda similar to 60 m, which suggests that the wake structures in the A ring are only similar to 6 m thick. C1 Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Oulu, Astron Div, FIN-90014 Oulu, Finland. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. US Geol Survey, Fed Ctr, Denver, CO 80225 USA. RP Hedman, MM (reprint author), Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. NR 25 TC 66 Z9 66 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 JUN PY 2007 VL 133 IS 6 BP 2624 EP 2629 DI 10.1086/516828 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 175BO UT WOS:000246987400015 ER PT J AU Elbaz, D Daddi, E Le Borgne, D Dickinson, M Alexander, DM Chary, RR Starck, JL Brandt, WN Kitzbichler, M MacDonald, E Nonino, M Popesso, P Stern, D Vanzella, E AF Elbaz, D. Daddi, E. Le Borgne, D. Dickinson, M. Alexander, D. M. Chary, R.-R. Starck, J.-L. Brandt, W. N. Kitzbichler, M. MacDonald, E. Nonino, M. Popesso, P. Stern, D. Vanzella, E. TI The reversal of the star formation-density relation in the distant universe SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE cosmology : observations; Galaxy : formation; Galaxy : evolution; galaxies : starburst; infrared : galaxies; cosmology : large-scale structure of Universe ID GALAXY REDSHIFT SURVEY; HUBBLE DEEP FIELD; MULTIBAND IMAGING PHOTOMETER; SPITZER-SPACE-TELESCOPE; ACTIVE GALACTIC NUCLEI; ENVIRONMENTAL DEPENDENCE; INFRARED GALAXIES; LUMINOUS GALAXIES; FORMATION HISTORY; FORMING GALAXIES AB Aims. We study the relationship between the local environment of galaxies and their star formation rate ( SFR) in the Great Observatories Origins Deep Survey, GOODS, at z similar to 1. Methods. We use ultradeep imaging at 24 mu m with the MIPS camera onboard Spitzer to determine the contribution of obscured light to the SFR of galaxies over the redshift range 0.8=<= z <= 1.2. Accurate galaxy densities are measured thanks to the large sample of similar to 1200 spectroscopic redshifts with high (similar to 70%) spectroscopic completeness. Morphology and stellar masses are derived from deep HST-ACS imaging, supplemented by ground based imaging programs and photometry from the IRAC camera onboard Spitzer. Results. We show that the star formation-density relation observed locally was reversed at z similar to 1: the average SFR of an individual galaxy increased with local galaxy density when the universe was less than half its present age. Hierarchical galaxy formation models (simulated lightcones from the Millennium model) predicted such a reversal to occur only at earlier epochs (z>2) and at a lower level. We present a remarkable structure at z similar to 1.016, containing X-ray traced galaxy concentrations, which will eventually merge into a Virgo-like cluster. This structure illustrates how the individual SFR of galaxies increases with density and shows that it is the similar to 1-2 Mpc scale that affects most the star formation in galaxies at z similar to 1. The SFR of z similar to 1 galaxies is found to correlate with stellar mass suggesting that mass plays a role in the observed star formation-density trend. However the specific SFR (=SFR/M-star) decreases with stellar mass while it increases with galaxy density, which implies that the environment does directly affect the star formation activity of galaxies. Major mergers do not appear to be the unique or even major cause for this effect since nearly half (46%) of the luminous infrared galaxies (LIRGs) at z similar to 1 present the HST-ACS morphology of spirals, while only a third present a clear signature of major mergers. The remaining galaxies are divided into compact (9%) and irregular (14%) galaxies. Moreover, the specific SFR of major mergers is only marginally stronger than that of spirals. Conclusions. These findings constrain the influence of the growth of large-scale structures on the star formation history of galaxies. Reproducing the SFR-density relation at z similar to 1 is a new challenge for models, requiring a correct balance between mass assembly through mergers and in-situ star formation at early epochs. C1 CEA Saclay, DSM, DAPNIA, Serv Astrophys, F-91191 Gif Sur Yvette, France. Univ Paris 07, CNRS, CEA, AIM Unite Mixte Rech, F-75221 Paris 05, France. Natl Opt Astron Observ, Tucson, AZ 85719 USA. Univ Durham, Dept Phys, Durham DH1 3LE, England. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Max Planck Inst Astrophys, D-85748 Garching, Germany. Osserv Astron Trieste, INAF, I-40131 Trieste, Italy. European So Observ, D-85748 Garching, Germany. CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Elbaz, D (reprint author), CEA Saclay, DSM, DAPNIA, Serv Astrophys, F-91191 Gif Sur Yvette, France. EM delbaz@cea.fr RI Starck, Jean-Luc/D-9467-2011; Daddi, Emanuele/D-1649-2012; Brandt, William/N-2844-2015; OI Starck, Jean-Luc/0000-0003-2177-7794; Daddi, Emanuele/0000-0002-3331-9590; Brandt, William/0000-0002-0167-2453; Nonino, Mario/0000-0001-6342-9662; Vanzella, Eros/0000-0002-5057-135X; Alexander, David/0000-0002-5896-6313 NR 73 TC 708 Z9 710 U1 0 U2 4 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2007 VL 468 IS 1 BP 33 EP 48 DI 10.1051/0004-6361:20077525 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174RA UT WOS:000246959000011 ER PT J AU Giommi, P Massaro, E Padovani, P Perri, M Cavazzuti, E Turriziani, S Tosti, G Colafrancesco, S Tagliaferri, G Chincarini, G Burrows, DN Chester, MM Gehrels, N AF Giommi, P. Massaro, E. Padovani, P. Perri, M. Cavazzuti, E. Turriziani, S. Tosti, G. Colafrancesco, S. Tagliaferri, G. Chincarini, G. Burrows, D. N. Chester, M. McMath Gehrels, N. TI ROXA J081009.9+384757.0: a 10(47) erg s(-1) blazar with hard X-ray synchrotron peak or a new type of radio loud AGN? SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE radiation mechanisms : non-thermal; galaxies : active; galaxies : individual : ROXA J081009.9+384757.0; X-rays : galaxies ID SKY SURVEY; BL LACS; QUASARS; SPECTRA; CATALOG; SWIFT AB We report the discovery of ROXAJ081009.9+384757.0 = SDSS J081009.9+384757.0, a z = 3.95 blazar with a highly unusual Spectral Energy Distribution. This object was first noticed as a probable high f(x)/f(r), high-luminosity blazar within the error region of a approximate to 10(-12) erg cm(-2) s(-1) ROSAT source which, however, also included a much brighter late-type star. We describe the results of a recent Swift observation that establishes beyond doubt that the correct counterpart of the X-ray source is the flat spectrum radio quasar. With a luminosity well in excess of 10(47) erg s(-1) ROXA J081009.9+ 384757.0 is therefore one of the most luminous blazars known. We consider various possibilities for the nature of the electromagnetic emission from this source. In particular, we show that the SED is consistent with that of a blazar with synchrotron power peaking in the hard X-ray band. If this is indeed the case, the combination of high-luminosity and synchrotron peak in the hard-X-ray band contradicts the claimed anti-correlation between luminosity and position of the synchrotron peak usually referred to as the "blazar sequence". An alternative possibility is that the X-rays are not due to synchrotron emission, in this case the very peculiar SED of ROXA J081009.9+ 384757.0 would make it the first example of a new class of radio loud AGN. C1 ESRIN, ASI Sci Data Ctr, I-00044 Frascati, Italy. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. European So Observ, D-8046 Garching, Germany. Univ Roma Tor Vergata, Dip Fis, I-00133 Rome, Italy. Univ Perugia, Dipartimento Fis, I-06100 Perugia, Italy. Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. Osserv Astron Brera, INAF, I-23807 Merate, Italy. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Giommi, P (reprint author), ESRIN, ASI Sci Data Ctr, I-00044 Frascati, Italy. EM paolo.giommi@asi.it RI Gehrels, Neil/D-2971-2012; Tosti, Gino/E-9976-2013; OI giommi, paolo/0000-0002-2265-5003; Padovani, Paolo/0000-0002-4707-6841; Perri, Matteo/0000-0003-3613-4409; Tagliaferri, Gianpiero/0000-0003-0121-0723 NR 37 TC 14 Z9 14 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2007 VL 468 IS 1 BP 97 EP 101 DI 10.1051/0004-6361:20066570 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174RA UT WOS:000246959000015 ER PT J AU Goad, MR Page, KL Godet, O Beardmore, A Osborne, JP O'Brien, PT Starling, R Holland, S Band, D Falcone, A Gehrels, N Burrows, DN Nousek, JA Roming, PWA Moretti, A Perri, M AF Goad, M. R. Page, K. L. Godet, O. Beardmore, A. Osborne, J. P. O'Brien, P. T. Starling, R. Holland, S. Band, D. Falcone, A. Gehrels, N. Burrows, D. N. Nousek, J. A. Roming, P. W. A. Moretti, A. Perri, M. TI Swift multi-wavelength observations of the bright flaring burst GRB 051117A SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts; gamma rays : observations ID GAMMA-RAY-BURSTS; ALERT TELESCOPE BAT; EMISSION-LINES; ENGINE ACTIVITY; MIDEX MISSION; PEAK ENERGY; XMM-NEWTON; JET MODEL; AFTERGLOW; SPECTRA AB We report on the temporal and spectral characteristics of the early X-ray emission from the Gamma Ray Burst 051117A as observed by Swift. The superb quality of the early X-ray light-curve and spectra of this source, one of the brightest seen by the X-ray Telescope at such early times, allows an unprecedented look at the spectral and temporal evolution of the prompt and early afterglow emission for this GRB and allows us to place stringent limits on the detection of lines. GRB 051117A displays a highly complex light-curve, with an apparent initial slow decline of slope alpha = 0.77 +/- 0.07 (f(t) proportional to t(-alpha)) dominated by numerous superposed flares of varying amplitude and duration. Between orbits 2 and 3, the X-ray light-curve drops abruptly, highlighting the dominance of flaring activity at early times, and indicating that the central engine for this burst remains active for several kiloseconds after the initial explosion. The late time slope (t > 10(4) s) also decays relatively slowly with a powerlaw index of alpha = 0.66, breaking to a steeper slope of 1.1, 170 ks after the BAT trigger. The X-ray light-curve at early times is characteristic of a noise process, consisting of random shots superposed on an underlying powerlaw decay, with individual shots well-modelled by a fast-rise and exponential decay spanning a broad range in rise-times and decay rates. A temporal spectral analysis of the early light-curve shows that the photon index and source intensity are highly correlated with the spectrum being significantly harder when brighter, consistent with the movement of the peak of the Band function to lower energies following individual flares. The high quality spectrum obtained from the first orbit of WT mode data, enables us to place a 3 sigma upper limit on the strength of any emission line features of EW < 15 eV, assuming a narrow emission-line of 100 eV at the peak of the effective area. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Penn State Univ, University Pk, PA 16802 USA. Osserv Astron Brera, INAF, I-23807 Merate, LC, Italy. ASI Sci Data Ctr, I-00044 Frascati, Italy. RP Goad, MR (reprint author), Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. EM mrg@star.le.ac.uk RI Gehrels, Neil/D-2971-2012; OI moretti, alberto/0000-0002-9770-0315; Perri, Matteo/0000-0003-3613-4409 NR 74 TC 22 Z9 22 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2007 VL 468 IS 1 BP 103 EP 112 DI 10.1051/0004-6361:20066874 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174RA UT WOS:000246959000016 ER PT J AU Giommi, P Capalbi, M Cavazzuti, E Colafrancesco, S Cucchiara, A Falcone, A Kennea, J Nesci, R Perri, M Tagliaferri, G Tramacere, A Tosti, G Blustin, AJ Branduardi-Raymont, G Burrows, DN Chincarini, G Dean, AJ Gehrels, N Krimm, H Marshall, F Parsons, AM Zhang, B AF Giommi, P. Capalbi, M. Cavazzuti, E. Colafrancesco, S. Cucchiara, A. Falcone, A. Kennea, J. Nesci, R. Perri, M. Tagliaferri, G. Tramacere, A. Tosti, G. Blustin, A. J. Branduardi-Raymont, G. Burrows, D. N. Chincarini, G. Dean, A. J. Gehrels, N. Krimm, H. Marshall, F. Parsons, A. M. Zhang, B. TI Swift detection of all previously undetected blazars in a micro-wave flux-limited sample of WMAP foreground sources SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE quasars : general; cosmology : cosmic microwave background; radiation mechanisms : non-thermal ID BL-LACERTAE OBJECTS; X-RAY TELESCOPE; VARIABILITY; EMISSION; CATALOG; SYNCHROTRON; BEPPOSAX; MISSION; FLARE; MAPS AB Almost the totality of the bright foreground sources in the WMAP Cosmic Microwave Background (CMB) maps are blazars, a class of sources that show usually also X-ray emission. However, 23 objects in a flux-limited sample of 140 blazars of the WMAP catalog (first year) were never reported before as X-ray sources. We present here the results of 41 Swift observations which led to the detection of all these 23 blazars in the 0.3-10 keV band. We conclude that all micro-wave selected blazars are X-ray emitters and that the distribution of the micro-wave to X-ray spectral slope (alpha(mu x)) of LBL blazars is very narrow, confirming that the X-ray flux of most blazars is a very good estimator of their micro-wave emission. The X-ray spectral shape of all the objects that were observed long enough to allow spectral analysis is flat and consistent with inverse Compton emission within the commonly accepted view where the radiation from blazars is emitted in a Sychrotron-Inverse-Compton scenario. We predict that all blazars and most radio galaxies above the sensitivity limit of the WMAP and of the Planck CMB missions are X-ray sources detectable by the present generation of X-ray satellites. An hypothetical all-sky soft X-ray survey with sensitivity of approximately 10(-15) erg cm(-2) s(-1) would be crucial to locate and remove over 100 000 blazars from CMB temperature and polarization maps and therefore accurately clean the primordial CMB signal from the largest population of extragalactic foreground contaminants. C1 ESRIN, ASDC, ASI Sci Data Ctr, I-00044 Frascati, Italy. Agenzia Spaziale Italiana, Unita Osservaz Univ, I-00198 Rome, Italy. Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Osserv Astron Brera, INAF, I-23807 Merate, Italy. Univ Perugia, Dipartimento Fis, I-06100 Perugia, Italy. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Univ Southampton, Southampton S017 1BJ, Hants, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. RP Giommi, P (reprint author), ESRIN, ASDC, ASI Sci Data Ctr, Via G Galilei, I-00044 Frascati, Italy. EM paolo.giommi@asi.it RI Gehrels, Neil/D-2971-2012; Parsons, Ann/I-6604-2012; Tosti, Gino/E-9976-2013; OI Perri, Matteo/0000-0003-3613-4409; Tramacere, Andrea/0000-0002-8186-3793; Tagliaferri, Gianpiero/0000-0003-0121-0723; giommi, paolo/0000-0002-2265-5003 NR 34 TC 15 Z9 15 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2007 VL 468 IS 2 BP 571 EP 579 DI 10.1051/0004-6361:20054160 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174RC UT WOS:000246959200018 ER PT J AU Ali, A Nuth, JA AF Ali, A. Nuth, J. A. TI The oxygen isotope effect in the earliest processed solids in the solar system: is it a chemical mass-independent process? SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE astrochemistry; solar system : formation; stars : planetary systems : protoplanetary disks; molecular processes; Sun : abundances; ISM : evolution ID OZONE FORMATION; INTRAMOLECULAR THEORY; ORIGIN; DEPENDENCE; METEORITES; STRANGE; NEBULA; DISKS; CO AB Aims. An anomalous effect in the abundances of oxygen isotopes in the most refractory calcium-aluminum-rich inclusions (CAIs) was discovered some thirty years ago. The origin of these oxygen isotopic anomalies has hitherto remained unexplained. The origin is neither nuclear, nor has the recent photochemical self-shielding explanation been proven to be valid. We discuss a possible chemical mechanism to resolve these observed effects. Methods. By uniting the most recent laboratory observations of nanoclusters of silicates in beams and the first principles theoretical studies of their structure and properties with a major dynamical constraint recently described as the surface non-RRKM effect during SiO(2) formation on the growing grain, we show that the origin of the anomalous isotopic effect in high-temperature minerals in CAIs is chemical and strictly mass-independent. Results. We report that the surface non-RRKM effect would represent a major process in the formation of our own solar system and observable protoplanetary accretion disks, and the mass-independent isotope effects are directly associated with the formation of primary grains in the high temperature nebular environment. We expect that this chemical reaction mechanistic approach combined with future time-resolved studies on the kinetics of growth of silicates and a precise knowledge of the oxygen isotopic abundances of the sun would provide a very detailed understanding of the origins of formation of our solar system. C1 NASA, Goddard Space Flight Ctr, Astrochem Lab, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. RP Ali, A (reprint author), NASA, Goddard Space Flight Ctr, Astrochem Lab, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. EM Ashraf.Ali@gsfc.nasa.gov RI Nuth, Joseph/E-7085-2012 NR 26 TC 5 Z9 5 U1 0 U2 3 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2007 VL 467 IS 3 BP 919 EP 923 DI 10.1051/0004-6361:20066925 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 169RV UT WOS:000246610300003 ER PT J AU Curran, PA van der Horst, AJ Beardmore, AP Page, KL Rol, E Melandri, A Steele, IA Mundell, CG Gomboc, A O'Brien, PT Bersier, DF Bode, MF Carter, D Guidorzi, C Hill, JE Hurkett, CP Kobayashi, S Monfardini, A Mottram, CJ Smith, RJ Wijers, RAMJ Willingale, R AF Curran, P. A. van der Horst, A. J. Beardmore, A. P. Page, K. L. Rol, E. Melandri, A. Steele, I. A. Mundell, C. G. Gomboc, A. O'Brien, P. T. Bersier, D. F. Bode, M. F. Carter, D. Guidorzi, C. Hill, J. E. Hurkett, C. P. Kobayashi, S. Monfardini, A. Mottram, C. J. Smith, R. J. Wijers, R. A. M. J. Willingale, R. TI The prompt to late-time multiwavelength analysis of GRB060210 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts; X-rays : individuals : GRB060210; ISM : dust, extinction; radiation mechanisms : non-thermal ID RAY BURST AFTERGLOWS; TELESCOPE; EMISSION; MISSION; SYSTEM; DUST AB Aims. We present our analysis of the multiwavelength photometric & spectroscopic observations of GRB 060210 and discuss the results in the overall context of current GRB models. Methods. All available optical data underwent a simultaneous temporal fit, while X-ray and gamma-ray observations were analysed temporally & spectrally. The results were compared to each other and to possible GRB models. Results. The X-ray afterglow is best described by a smoothly broken power-law with a break at 7.4 h. The late optical afterglow has a well constrained single power-law index which has a value between the two X-ray indices, though it does agree with a single power-law fit to the X-ray. An evolution of the hardness of the high-energy emission is demonstrated and we imply a minimum host extinction from a comparison of the extrapolated X-ray flux to that measured in the optical. Conclusions. We find that the flaring gamma-ray and X-ray emission is likely due to internal shocks while the flat optical light curve at that time is due to the external shock. The late afterglow is best explained by a cooling break between the optical and X-rays and continued central engine activity up to the time of the break. The required collimation corrected energy of similar to 2 x 10(52) erg, while at the high end of the known energy distribution, is not unprecedented. C1 Univ Amsterdam, Astron Inst, NL-1098 SJ Amsterdam, Netherlands. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. Univ Ljubljana, Fac Math & Phys, Ljubljana 1000, Slovenia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Curran, PA (reprint author), Univ Amsterdam, Astron Inst, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. EM pcurran@science.uva.nl RI Curran, Peter/B-5293-2013; OI Curran, Peter/0000-0003-3003-4626; Wijers, Ralph/0000-0002-3101-1808 NR 38 TC 28 Z9 28 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2007 VL 467 IS 3 BP 1049 EP 1055 DI 10.1051/0004-6361:20077055 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 169RV UT WOS:000246610300015 ER PT J AU Macias-Perez, JF Lagache, G Maffei, B Ganga, K Bourrachot, A Ade, P Amblard, A Ansari, R Aubourg, E Aumont, J Bargot, S Bartlett, J Benoit, A Bernard, JP Bhatia, R Blanchard, A Bock, JJ Boscaleri, A Bouchet, FR Camus, P Cardoso, JF Couchot, F de Bernardis, P Delabrouille, J Desert, FX Dore, O Douspis, M Dumoulin, L Dupac, X Filliatre, P Fosalba, P Gannaway, F Gautier, B Giard, M Giraud-Heraud, Y Gispert, R Guglielmi, L Hamilton, JC Hanany, S Henrot-Versille, S Hristov, V Kaplan, J Lamarre, JM Lange, AE Madet, K Magneville, C Marrone, DP Masi, S Mayet, F Murphy, JA Naraghi, F Nati, F Patanchon, G Perdereau, O Perrin, G Plaszczynski, S Piat, M Ponthieu, N Prunet, S Puget, JL Renault, C Rosset, C Santos, D Starobinsky, A Strukov, I Sudiwala, RV Teyssier, R Tristram, M Tucker, C Vanel, JC Vibert, D Wakui, E Yvon, D AF Macias-Perez, J. F. Lagache, G. Maffei, B. Ganga, K. Bourrachot, A. Ade, P. Amblard, A. Ansari, R. Aubourg, E. Aumont, J. Bargot, S. Bartlett, J. Benoit, A. Bernard, J.-Ph. Bhatia, R. Blanchard, A. Bock, J. J. Boscaleri, A. Bouchet, F. R. Camus, P. Cardoso, J.-F. Couchot, F. de Bernardis, P. Delabrouille, J. Desert, F.-X. Dore, O. Douspis, M. Dumoulin, L. Dupac, X. Filliatre, Ph. Fosalba, P. Gannaway, F. Gautier, B. Giard, M. Giraud-Heraud, Y. Gispert, R. Guglielmi, L. Hamilton, J.-Ch. Hanany, S. Henrot-Versille, S. Hristov, V. Kaplan, J. Lamarre, J.-M. Lange, A. E. Madet, K. Magneville, Ch. Marrone, D. P. Masi, S. Mayet, F. Murphy, J. A. Naraghi, F. Nati, F. Patanchon, G. Perdereau, O. Perrin, G. Plaszczynski, S. Piat, M. Ponthieu, N. Prunet, S. Puget, J.-L. Renault, C. Rosset, C. Santos, D. Starobinsky, A. Strukov, I. Sudiwala, R. V. Teyssier, R. Tristram, M. Tucker, C. Vanel, J.-Ch. Vibert, D. Wakui, E. Yvon, D. TI Archeops in-flight performance, data processing, and map making SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE methods : data analysis; cosmic microwave background ID BACKGROUND POWER SPECTRUM; PROBE WMAP OBSERVATIONS; GALACTIC DUST EMISSION; CMB EXPERIMENTS; HIGH-RESOLUTION; MICROWAVE; ANISOTROPY; TEMPERATURE; POLARIZATION; FIRAS AB Aims. Archeops is a balloon-borne experiment inspired by the Planck satellite and its high frequency instrument ( HFI). It is designed to measure the cosmic microwave background ( CMB) temperature anisotropies at high angular resolution (similar to 12 arcmin) over a large fraction of the sky ( around 30%) at 143, 217, 353, and 545 GHz. The Archeops 353 GHz channel consists of three pairs of polarized sensitive bolometers designed to detect the polarized diffuse emission of Galactic dust. Methods. In this paper we present an update of the instrumental setup, as well as the flight performance for the last Archeops flight campaign ( February 2002 from Kiruna, Sweden). We also describe the processing and analysis of the Archeops time-ordered data for that campaign, which led to measurement of the CMB anisotropy power spectrum in the multipole range l = 10-700 and to the first measurements of both the polarized emission of dust at large angular scales and its power spectra in the multipole range l = 3-70 Results. We present maps covering approximately 30% of the sky. These maps contain Galactic emission, including the Galactic plane, in the four Archeops channels at 143, 217, 353, and 545 GHz and CMB anisotropies at 143 and 217 GHz. These are one of the first sub-degree-resolution maps in the millimeter and submillimeter ranges of the large angular-scale diffuse Galactic dust emission and CMB temperature anisotropies, respectively. C1 Univ Grenoble 1, LPSC, CNRS IN2P3, Inst Natl Polytech Grenoble, F-38026 St Martin Dheres, France. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. Univ Cardiff Wales, Dept Phys, Cardiff CF24 3YB, Wales. Coll France, APC, F-75231 Paris 5, France. Lab Accelerateur Lineaire, F-91898 Orsay, France. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. DAPNIA, CEA CE Saclay, Serv Phys Particules, F-91191 Gif Sur Yvette, France. CNRS, Ctr Rech Tres Basses Temp, BP 166, F-38042 Grenoble 9, France. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. Estec, Noordwijk, Netherlands. Lab Astrophys Tarbes Toulouse, F-31400 Toulouse, France. CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CNR, IROE, I-50127 Florence, Italy. Inst Astrophys, F-75014 Paris, France. CNRS, ENST, F-75634 Paris, France. Univ Roma La Sapienza, Grp Cosmol Sperimentale, Dipartimento Fis, I-00185 Rome, Italy. Observ Grenoble, Astrophys Lab, F-38041 Grenoble, France. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Univ Toronto, CITA, Toronto, ON M5S 3H8, Canada. CSNSM, IN2P3, F-91405 Orsay, France. DAPNIA, Serv Astrophys, CEA CE Saclay, F-91191 Gif Sur Yvette, France. Inst Ciencias Espacio, IEEC CSIC, Fac Ciencias, Cerdanyola Del Valles, Spain. Univ Paris 06, LPNHE, F-75252 Paris 05, France. Univ Paris 07, LPNHE, F-75252 Paris 05, France. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Observ Paris, LERMA, F-75014 Paris, France. Natl Univ Ireland, Maynooth, Kildare, Ireland. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V5Z 1M9, Canada. LD Landau Theoret Phys Inst, Moscow 119334, Russia. Space Res Inst, Moscow, Russia. RP Macias-Perez, JF (reprint author), Univ Grenoble 1, LPSC, CNRS IN2P3, Inst Natl Polytech Grenoble, 53 Ave Martyrs, F-38026 St Martin Dheres, France. EM reprints@archeops.org 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 Starobinsky, Alexei/0000-0002-8946-9088; amblard, alexandre/0000-0002-2212-5395; Nati, Federico/0000-0002-8307-5088; Marrone, Daniel/0000-0002-2367-1080; Masi, Silvia/0000-0001-5105-1439; de Bernardis, Paolo/0000-0001-6547-6446; Bouchet, Francois/0000-0002-8051-2924 NR 60 TC 20 Z9 21 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2007 VL 467 IS 3 BP 1313 EP 1344 DI 10.1051/0004-6361:20065258 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 169RV UT WOS:000246610300042 ER PT J AU Moiseev, AA Hartman, RC Ormes, JF Thompson, DJ Amato, MJ Johnson, TE Segal, KN Sheppard, DA AF Moiseev, A. A. Hartman, R. C. Ormes, J. F. Thompson, D. J. Amato, M. J. Johnson, T. E. Segal, K. N. Sheppard, D. A. TI The anti-coincidence detector for the GLAST large area telescope SO ASTROPARTICLE PHYSICS LA English DT Article DE gamma-ray telescope; plastic scintillating detector; particle detection efficiency ID ENGINEERING MODEL; BEAM TEST; RAY; SPECTRA; MISSION; EGRET AB This paper describes the design, fabrication and testing of the Anti-Coincidence Detector (ACD) for the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT). The ACD is LATs first-level defense against the charged cosmic ray background that outnumbers the gamma rays by 3-5 orders of magnitude. The ACD covers the top and four sides of the LAT tracking detector, requiring a total active area of similar to 8.3 m(2). The ACD detector utilizes plastic scintillator tiles with wavelength shifting fiber readout. In order to suppress self-veto by shower particles at high gamma-ray energies, the ACD is segmented into 89 tiles of different sizes. The overall ACD efficiency for detection of singly charged relativistic particles entering the tracking detector from the top or sides of the LAT exceeds the required 0.9997. (c) 2006 Elsevier B.V. All rights reserved. C1 Univ Space Res Assoc, Columbia, MD 21044 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Moiseev, AA (reprint author), Univ Space Res Assoc, Columbia, MD 21044 USA. EM Moiseev@milkyway.gsfc.nasa.gov RI Thompson, David/D-2939-2012 OI Thompson, David/0000-0001-5217-9135 NR 18 TC 23 Z9 23 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD JUN PY 2007 VL 27 IS 5 BP 339 EP 358 DI 10.1016/j.astropartphys.2006.12.003 PG 20 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 181CB UT WOS:000247413300003 ER PT J AU Uchiyama, Y Urry, CM Coppi, P Van Duyne, J Cheung, CC Sambruna, RM Takahashi, T Tavecchio, F Maraschi, L AF Uchiyama, Yasunobu Urry, C. Megan Coppi, Paolo Van Duyne, Jeffrey Cheung, C. C. Sambruna, Rita M. Takahashi, Tadayuki Tavecchio, Fabrizio Maraschi, Laura TI An infrared study of the large-scale jet in quasar PKS 1136-135 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : jets; infrared : galaxies; quasars : individual (PKS 1136-135); radiation mechanisms : nonthermal ID X-RAY-EMISSION; ACTIVE GALACTIC NUCLEI; SPITZER-SPACE-TELESCOPE; INVERSE COMPTON-SCATTERING; EXTENDED RADIO JETS; CHANDRA OBSERVATIONS; EXTRAGALACTIC JETS; RELATIVISTIC JET; ARRAY CAMERA; SYNCHROTRON AB We present Spitzer IRAC imaging of the large-scale jet in the quasar PKS 1136 - 135 at wavelengths of 3.6 and 5: 8 mu m, combined with previous VLA, HST, and Chandra observations. We clearly detect infrared emission from the jet, resulting in the most detailed multifrequency data among the jets in lobe-dominated quasars. The spectral energy distributions of the jet knots have significant variations along the jet, like the archetypal jet in 3C 273. The infrared measurements with IRAC are consistent with the previous idea that the jet has two spectral components, namely (1) the low-energy synchrotron spectrum extending from radio to infrared, and ( 2) the high-energy component responsible for the X-ray flux. The optical fluxes may be a mixture of the two components. We consider three radiation models for the high-energy component: inverse Compton scattering of cosmic microwave background (CMB) photons by radio-emitting electrons in a highly relativistic jet, synchrotron radiation by a second distinct electron population, and synchrotron radiation by ultra-high- energy protons. Each hypothesis leads to important insights into and constraints on particle acceleration in the jet, as well as the basic physical properties of the jet such as bulk velocity, transporting power, and particle contents. C1 JAXA, ISAS, Dept High Energy Astrophys, Sagamihara, Kanagawa 2298510, Japan. Yale Univ, Yale Ctr Astron & Astrophys, New Haven, CT 06520 USA. Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. Osserv Astron Brera, I-20121 Milan, Italy. RP Uchiyama, Y (reprint author), JAXA, ISAS, Dept High Energy Astrophys, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 2298510, Japan. EM uchiyama@astro.isas.jaxa.jp RI Urry, Claudia/G-7381-2011 OI Urry, Claudia/0000-0002-0745-9792 NR 55 TC 9 Z9 9 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 1 PY 2007 VL 661 IS 2 BP 719 EP 727 DI 10.1086/518089 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174MT UT WOS:000246947100009 ER PT J AU Starling, RLC Wijers, RAMJ Wiersema, K Rol, E Curran, PA Kouveliotou, C Van der Horst, AJ Heemskerk, MHM AF Starling, R. L. C. Wijers, R. A. M. J. Wiersema, K. Rol, E. Curran, P. A. Kouveliotou, C. Van der Horst, A. J. Heemskerk, M. H. M. TI Gamma-ray burst afterglows as probes of environment and blast wave physics. I. Absorption by host-galaxy gas and dust SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : ISM; gamma rays : bursts ID LARGE-MAGELLANIC-CLOUD; 14 DECEMBER 1997; TIME-DEPENDENT PHOTOIONIZATION; INFRARED EXTINCTION LAW; HIGH-REDSHIFT GALAXIES; BROAD-BAND AFTERGLOW; HIGH COLUMN DENSITY; X-RAY; STAR-FORMATION; GRB 970508 AB We use a new approach to obtain limits on the absorbing columns toward an initial sample of 10 long gamma-ray bursts observed with BeppoSAX and selected on the basis of their good optical and near-infrared (NIR) coverage, from simultaneous fits to NIR, optical, and X-ray afterglow data, in count space and including the effects of metallicity. In no cases is a Milky Way-like ( MW) extinction preferred when testing MW, LMC, and SMC extinction laws. The 2175 angstrom bump would in principle be detectable in all these afterglows, but is not present in the data. An SMC-like gas-to-dust ratio or lower value can be ruled out for four of the hosts analyzed here ( assuming SMC metallicity and extinction law), while the remainder of the sample have too large an error to discriminate. We provide a more accurate estimate of the line-of-sight extinction and improve on the uncertainties for the majority of the extinction measurements made in previous studies of this sample. We discuss this method for determining extinction values in comparison with the most commonly employed existing methods. C1 Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. NASA, Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. RP Starling, RLC (reprint author), Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. EM rlcs1@star.le.ac.uk RI Curran, Peter/B-5293-2013; OI Curran, Peter/0000-0003-3003-4626; Wijers, Ralph/0000-0002-3101-1808 NR 127 TC 61 Z9 61 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 1 PY 2007 VL 661 IS 2 BP 787 EP 800 DI 10.1086/511953 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174MT UT WOS:000246947100014 ER PT J AU Pirali, O Vervloet, M Dahl, JE Carlson, RMK Tielens, AGGM Oomens, J AF Pirali, Olivier Vervloet, Michel Dahl, Jeremy E. Carlson, Robert M. K. Tielens, A. G. G. M. Oomens, Jos TI Infrared spectroscopy of diamondoid molecules: New insights into the presence of nanodiamonds in the interstellar medium SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : ISM; ISM : individual (Elias 1, HD 97048); ISM : molecules; methods : laboratory ID 3 MICRON SPECTRA; H2O ICE BANDS; NANOCRYSTAL SURFACES; STRETCHING FEATURES; EMISSION BANDS; SIZE; HYDROCARBONS; METEORITES; HD-97048; CLOUDS AB Although they are relatively different in band shape, infrared features around 3.4 - 3.5 mu m in the emission spectra of HD 97048 and Elias 1 and in the absorption spectra of various dense clouds have both been attributed to diamondoid molecules/particles. This assignment is based mainly on infrared spectra of hydrogenated diamond thin films and of diamond nanocrystals of known average size. Here we present an analysis of the astrophysical implications of recently reported solid-state 2.5 - 12.5 mu m spectra of individual diamondoid molecules, up to the size of hexamantane (C(26)H(30)). These spectra provide the first experimental measurements of the infrared frequencies of this class of molecules. In addition, laboratory gas-phase infrared emission spectra of the three smallest members of the diamondoid family are reported, as well as theoretical spectra for some larger species. The present data set allows us to relate spectral signatures to the molecular size and structure. The spectra of tetrahedral diamondoids are found to be qualitatively different from those of lower symmetry species, which possibly explains the differences between the astrophysical emission and absorption spectra. Interestingly, the 3.53 mu m band is clearly observed in the spectra of these small molecular diamondoids, whereas previous studies on nanodiamond particles found this band only for species larger than approximate to 50 nm. Our results support the assignment of the 3.43 and 3.53 mu m emission features in HD 97048 and Elias 1 to diamondoids of a few nanometers in size as well as the suggestion that smaller diamondoid molecules contribute to the 3.47 mu m interstellar absorption band. C1 FOM, Inst Plasma Phys Rijnhuizen, NL-3439 MN Nieuwegein, Netherlands. Univ Paris 11, Lab Photophys Mol, F-91405 Orsay, France. Chevron Texaco Technol Ventures, Mol Diamond Technol, Richmond, CA 94802 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Oomens, J (reprint author), FOM, Inst Plasma Phys Rijnhuizen, Edisonbaan 14, NL-3439 MN Nieuwegein, Netherlands. EM joso@rijnhuizen.nl RI Oomens, Jos/F-9691-2015 NR 28 TC 29 Z9 29 U1 0 U2 15 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 2007 VL 661 IS 2 BP 919 EP 925 DI 10.1086/516731 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174MT UT WOS:000246947100025 ER PT J AU Falanga, M Titarchuk, L AF Falanga, Maurizio Titarchuk, Lev TI Energy-dependent similar to 100 mu s time lags as observational evidence of comptonization effects in the neutron star plasma environment SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; pulsars : individual (IGR J00291+5934, SAX J1808.4-3658, XTE J1751-305); stars : neutron; X-rays : binaries ID MILLISECOND PULSAR SAX-J1808.4-3658; X-RAY BINARIES; SAX J1808.4-3658; CYGNUS X-1; PHASE LAGS; ACCRETION; RADIATION; EMISSION; SPECTROSCOPY; SPECTRA AB We present a Comptonization model for the observed properties of the energy-dependent soft/hard time lags and pulsed fraction (amplitude) associated with the pulsed emission of a neutron star (NS). We account for the soft lags by downscattering of hard X-ray photons in the relatively cold plasma of the disk or NS surface. A fraction of the soft X-ray photons coming from the disk or NS surface upscatter off hot electrons in the accretion column. This effect leads to hard lags as a result of thermal Comptonization of the soft photons. This model reproduces the observed soft and hard lags due to the down- and upscattered radiation as a function of the electron number densities of the reflector, n(e)(ref), and the accretion column, n(e)(hot). In the case of the accretion-powered millisecond pulsars IGR J00291+5934, XTE J1751-305, and SAX J1808.4-3658, the observed time lags agree well with the model. Soft lags are observed only if n(e)(ref) << n(e)(hot). Scattering of the pulsed emission in the NS environment may account for the observed time lags as a nonmonotonic function of energy. The time lag measurements can be used as a probe of the innermost parts of the NS and accretion disk. We determine the upper and lower limits of the density variation in this region using the observed time lags. The observed energy-dependent pulsed amplitude allows us to infer a variation of the Thomson optical depth of the Compton cloud in which the accretion column is embedded. C1 CEA Saclay, CNRS, DSM, DAPNIA,Serv Astrophys,FRE 2591, F-91191 Gif Sur Yvette, France. UMR Astroparticule & Cosmol, F-75005 Paris, France. George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Ferrara, Dipartmento Fis, I-44100 Ferrara, Italy. NASA, Goddard Space Flight Ctr, Explorat Universe Div, Greenbelt, MD 20771 USA. RP Falanga, M (reprint author), CEA Saclay, CNRS, DSM, DAPNIA,Serv Astrophys,FRE 2591, F-91191 Gif Sur Yvette, France. EM mfalanga@cea.fr; ltitarchuk@ssd5.nrl.navy.mil NR 23 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 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 2007 VL 661 IS 2 BP 1084 EP 1088 DI 10.1086/514805 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174MT UT WOS:000246947100040 ER PT J AU Tan, LC Reames, DV Ng, CK AF Tan, Lun C. Reames, Donald V. Ng, Chee K. TI Bulk flow velocity and first-order anisotropy of solar energetic particles observed on the wind spacecraft: Overview of three "gradual" particle events SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; interplanetary medium; shock waves; Sun : coronal mass ejections (CMEs); Sun : particle emission ID INTERPLANETARY TRAVELING SHOCKS; HYDROMAGNETIC WAVE EXCITATION; CORONAL MASS EJECTION; MAGNETIC-FIELD; ION-ACCELERATION; HEAVY-IONS; ANGULAR-DISTRIBUTIONS; PROTON OBSERVATIONS; COSMIC RAYS; 1 AU AB We have developed techniques to calculate bulk flow velocity and first-order anisotropy of solar energetic particles (SEPs) with MeV nucleon(-1) energies as recorded on the Wind spacecraft. Using the techniques we selected and analyzed three gradual SEP events having different solar longitudes. Since upstream of interplanetary ( IP) shocks during our selected events the interplanetary magnetic field is nearly perpendicular to the solar wind, the diffusive transport of SEPs along the magnetic field line is conveniently decoupled from solar-wind streaming. We present the bulk flow velocity measurements of H, He, O, and Fe ions at different energies. In two of the three events studied, it is seen that the flow directions of heavy ions reverse in sequence, i. e., faster ions reverse their direction earlier. Several hours before the IP shock passage, the bulk flows of all heavy ions become opposite to the proton flow. Thus, in the upstream region we mainly observe shock-accelerated protons that continue to flow away from the shock, while higher rigidity heavy ions predominantly come from strong acceleration near the Sun. The reversed ion direction appears also to involve a reflecting boundary beyond 1 AU, from which higher velocity ions return earlier. The preferred geometry of the selected 2001 September 24 event also allows us to determine the propagating direction of proton-generated Alfven waves based on flow velocity measurements of heavy ions. C1 Perot Syst, Fairfax, VA 22031 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Tan, LC (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM ltan@mail630.gsfc.nasa.gov NR 54 TC 5 Z9 5 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 2007 VL 661 IS 2 BP 1297 EP 1310 DI 10.1086/516626 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174MT UT WOS:000246947100059 ER PT J AU Baines, EK Van Belle, GT Ten Brummelaar, TA McAlister, HA Swain, M Turner, NH Sturmann, L Sturmann, J AF Baines, Ellyn K. Van Belle, Gerard T. Ten Brummelaar, Theo A. McAlister, Harold A. Swain, Mark Turner, Nils H. Sturmann, Laszlo Sturmann, Judit TI Direct measurement of the radius and density of the transiting exoplanet HD 189733B with the Chara array SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : stars; stars : fundamental parameters; stars : individual (HD 189733); techniques : interferometric ID SYSTEM; INTERFEROMETER; PHOTOMETRY; HD-189733; STARS; PARAMETERS; PASSBANDS; LIBRARY; SEARCH; PLANET AB We have measured the angular diameter of the transiting extrasolar planet host star HD 189733 using the CHARA optical/IR interferometric array. Combining our new angular diameter of 0.377 +/- 0.024 mas with the Hipparcos parallax leads to a linear radius for the host star of 0.779 +/- 0.052 R circle dot and a radius for the planet of 1.19 +/- 0.08 R-Jup. Adopting the mass of the planet as derived by its discoverers, we derive a mean density of the planet of 0.91 +/- 0.18 g cm(-3). This is the first determination of the diameter of an extrasolar planet through purely direct means. C1 Georgia State Univ, Ctr High Angular Resolut Astron, Atlanta, GA 30302 USA. CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Baines, EK (reprint author), Georgia State Univ, Ctr High Angular Resolut Astron, POB 3969, Atlanta, GA 30302 USA. EM baines@chara.gsu.edu; gerard@ipac.caltech.edu; theo@chara-array.org; hal@chara.gsu.edu; mark.swain@jpl.nasa.gov; nils@chara-array.org; sturmann@chara-array.org; judit@chara-array.org NR 25 TC 31 Z9 31 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 2007 VL 661 IS 2 BP L195 EP L198 DI 10.1086/519002 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174MY UT WOS:000246947600021 ER PT J AU Ghosh, KK Punsly, B AF Ghosh, Kajal K. Punsly, Brian TI The physical nature of polar broad absorption line quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; galaxies : jets; quasars : absorption lines; quasars : general ID HOLE ACCRETION VORTICES; ACTIVE GALACTIC NUCLEI; SUBRELATIVISTIC JETS; EMISSION-LINE; CONTINUUM; OUTFLOWS; MODELS AB In a recent article of Zhou et al., it has been shown, based on radio-variability arguments, that some BALQSOs (broad absorption line quasars) are viewed along the polar axis (orthogonal to accretion disk). These arguments are based on the brightness temperature T-b exceeding 10(12) K, which leads to the well-known inverse Compton catastrophe unless the radio jet is relativistic and is viewed along its axis. In this Letter, we expand the Zhou et al. sample of polar BALQSOs to the entire SDSS DR5 (Sloan Digital Sky Survey Data Release 5). In the process, we clarify a mistake in their calculation of the brightness temperature. The expanded sample of high T-b BALQSOs has an inordinately large fraction of LoBALQSOs (low-ionization BALQSOs). We consider this an important clue to understanding the nature of the polar BALQSOs. This is expected in the polar BALQSO analytical/numerical models of Punsly, in which LoBALQSOs occur when the line of sight is very close to the polar axis, where the outflow density is the highest. C1 NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. Univ Roma La Sapienza, ICRA, I-00185 Rome, Italy. RP Ghosh, KK (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, VP62, Huntsville, AL 35812 USA. EM brian.m.punsly@L-3com.com; brian.punsly@gte.net NR 20 TC 41 Z9 41 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 1 PY 2007 VL 661 IS 2 BP L139 EP L142 DI 10.1086/518859 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174MY UT WOS:000246947600007 ER PT J AU Perets, HB Lederhendler, A Biham, O Vidali, G Li, L Swords, S Congiu, E Roser, J Manico, G Brucato, JR Pirronello, V AF Perets, H. B. Lederhendler, A. Biham, O. Vidali, G. Li, L. Swords, S. Congiu, E. Roser, J. Manico, G. Brucato, J. R. Pirronello, V. TI Molecular hydrogen formation on amorphous silicates under interstellar conditions SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; ISM : molecules; molecular processes ID WATER ICE; SURFACE-MORPHOLOGY; GRAIN SURFACES; H-2 FORMATION; RECOMBINATION; ADSORPTION; ATOMS AB Experimental results on the formation of molecular hydrogen on amorphous silicate surfaces are presented for the first time and analyzed using a rate equation model. The energy barriers for the relevant diffusion and desorption processes are obtained. They turn out to be significantly higher than those obtained earlier for polycrystalline silicates, demonstrating the importance of grain morphology. Using these barriers, we evaluate the efficiency of molecular hydrogen formation on amorphous silicate grains under interstellar conditions. It is found that unlike polycrystalline silicates, amorphous silicate grains are efficient catalysts of H-2 formation within a temperature range that is relevant to diffuse interstellar clouds. The results also indicate that the hydrogen molecules are thermalized with the surface and desorb with low kinetic energy. Thus, they are unlikely to occupy highly excited states. C1 Weizmann Inst Sci, Fac Phys, IL-76100 Rehovot, Israel. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Syracuse Univ, Dept Phys, Syracuse, NY 13244 USA. Univ Cagliari, Dipartimento Fis, Cagliari, Italy. Univ Catania, DMFCI, I-95125 Catania, Sicily, Italy. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Osserv Astron Capodimonte, INAF, I-80131 Naples, Italy. RP Perets, HB (reprint author), Weizmann Inst Sci, Fac Phys, IL-76100 Rehovot, Israel. RI Perets, Hagai/K-9605-2015; OI Perets, Hagai/0000-0002-5004-199X; Manico, Giulio/0000-0002-6428-1871; Brucato, John Robert/0000-0002-4738-5521 NR 26 TC 42 Z9 42 U1 0 U2 14 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 2007 VL 661 IS 2 BP L163 EP L166 DI 10.1086/518862 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174MY UT WOS:000246947600013 ER PT J AU Wang, TJ Sui, L Qiu, J AF Wang, Tongjiang Sui, Linhui Qiu, Jiong TI Direct observation of high-speed plasma outflows produced by magnetic reconnection in solar impulsive events SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : flares; Sun : UV radiation; Sun : X-rays, gamma rays ID CORONAL MASS EJECTION; X-RAY SOURCE; LOOP OSCILLATIONS; DOPPLER SHIFTS; FLARE; TRACE; FIELD; ARCADE; SHEET; JETS AB Spectroscopic observations of a solar limb flare recorded by SUMER on SOHO reveal for the first time hot, fast magnetic reconnection outflows in the corona. As the reconnection site rises across the SUMER spectrometer slit, significant blue- and redshift signatures are observed in sequence in the Fe XIX line, reflecting upflows and downflows of hot plasma jets, respectively. With the projection effect corrected, the measured outflow speed is between similar to 900 and 3500 km s(-1), consistent with theoretical predictions of the Alfvenic outflows in magnetic reconnection region in solar impulsive events. Based on theoretic models, the magnetic field strength near the reconnection region is estimated to be 19-37 G. C1 Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Greenbelt, MD 20771 USA. RP Wang, TJ (reprint author), Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. EM wangtj@solar.physics.montana.edu NR 21 TC 60 Z9 60 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 2007 VL 661 IS 2 BP L207 EP L210 DI 10.1086/519004 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 174MY UT WOS:000246947600024 ER PT J AU Jarosik, N Barnes, C Greason, MR Hill, RS Nolta, MR Odegard, N Weiland, JL Bean, R Bennett, CL Dore, O Halpern, M Hinshaw, G Kogut, A Komatsu, E Limon, M Meyer, SS Page, L Spergel, DN Tucker, GS Wollack, E Wright, EL AF Jarosik, N. Barnes, C. Greason, M. R. Hill, R. S. Nolta, M. R. Odegard, N. Weiland, J. L. Bean, R. Bennett, C. L. Dore, O. Halpern, M. Hinshaw, G. Kogut, A. Komatsu, E. Limon, M. Meyer, S. S. Page, L. Spergel, D. N. Tucker, G. S. Wollack, E. Wright, E. L. TI Three-year Wilkinson Microwave Anisotropy Probe (WMAP)(1) observations: Beam profiles, data processing, radiometer characterization, and systematic error limits SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE cosmic microwave background; instrumentation : detectors; space vehicles : instruments ID ANGULAR POWER SPECTRUM; WMAP OBSERVATIONS; DESIGN AB The WMAP satellite has completed 3 years of observations of the cosmic microwave background radiation. The 3 year data products include several sets of full sky maps of the Stokes I, Q, and U parameters in five frequency bands, spanning 23-94 GHz, and supporting items such as beam window functions and noise covariance matrices. The processing used to produce the current sky maps and supporting products represents a significant advancement over the first-year analysis and is described herein. Improvements to the pointing reconstruction, radiometer gain modeling, window function determination, and radiometer spectral noise parameterization are presented. A detailed description of the updated data processing that produces maximum likelihood sky map estimates is presented, along with the methods used to produce reduced resolution maps and corresponding noise covariance matrices. Finally, two methods used to evaluate the noise of the full resolution sky maps are presented along with several representative year-to-year null tests, demonstrating that sky maps produced from data from different observational epochs are consistent. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc SSAI, Lanham, MD 20706 USA. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Cornell Univ, Ithaca, NY 14853 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Chicago, Dept Astrophys & Phys, KICP, Chicago, IL 60637 USA. Univ Chicago, Dept Astrophys & Phys, EFI, Chicago, IL 60637 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. RP Jarosik, N (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. EM jarosik@princeton.edu RI Kogut, Alan/D-6293-2012; Komatsu, Eiichiro/A-4361-2011; Spergel, David/A-4410-2011; Wollack, Edward/D-4467-2012 OI Wollack, Edward/0000-0002-7567-4451 NR 27 TC 136 Z9 136 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 JUN PY 2007 VL 170 IS 2 BP 263 EP 287 DI 10.1086/513697 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178TD UT WOS:000247242100001 ER PT J AU Hinshaw, G Nolta, MR Bennett, CL Bean, R Dore, O Greason, MR Halpern, M Hill, RS Jarosik, N Kogut, A Komatsu, E Limon, M Odegard, N Meyer, SS Page, L Peiris, HV Spergel, DN Tucker, GS Verde, L Weiland, JL Wollack, E Wright, EL AF Hinshaw, G. Nolta, M. R. Bennett, C. L. Bean, R. Dore, O. Greason, M. R. Halpern, M. Hill, R. S. Jarosik, N. Kogut, A. Komatsu, E. Limon, M. Odegard, N. Meyer, S. S. Page, L. Peiris, H. V. Spergel, D. N. Tucker, G. S. Verde, L. Weiland, J. L. Wollack, E. Wright, E. L. TI Three-year Wilkinson Microwave Anisotropy Probe (WMAP(1)) observations: Temperature analysis SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE cosmic microwave background; cosmology : observations; dark matter; early universe; instrumentation : detectors; space vehicles : instruments; telescopes ID ANGULAR POWER SPECTRUM; NRAO PMN SURVEYS; FAR-INFRARED EMISSION; RADIO-CONTINUUM EMISSION; COSMIC BACKGROUND IMAGER; NORTHERN SKY SURVEY; SPIRAL GALAXIES; SOURCE CATALOG; STATISTICAL-ANALYSIS; COSMOLOGICAL PARAMETERS AB We present new full-sky temperature maps in five frequency bands from 23 to 94 GHz, based on data from the first 3 years of the WMAP sky survey. The new maps are consistent with the first-year maps and are more sensitive. The 3 year maps incorporate several improvements in data processing made possible by the additional years of data and by a more complete analysis of the polarization signal. These include several new consistency tests as well as refinements in the gain calibration and beam response models. We employ two forms of multifrequency analysis to separate astrophysical foreground signals from the CMB, each of which improves on our first-year analyses. First, we form an improved "Internal Linear Combination'' ( ILC) map, based solely on WMAP data, by adding a bias-correction step and by quantifying residual uncertainties in the resulting map. Second, we fit and subtract new spatial templates that trace Galactic emission; in particular, we now use low-frequency WMAP data to trace synchrotron emission instead of the 408 MHz sky survey. The WMAP point source catalog is updated to include 115 new sources whose detection is made possible by the improved sky map sensitivity. We derive the angular power spectrum of the temperature anisotropy using a hybrid approach that combines a maximum likelihood estimate at low l ( large angular scales) with a quadratic cross-power estimate for l > 30. The resulting multifrequency spectra are analyzed for residual point source contamination. At 94 GHz the unmasked sources contribute 128 +/- 27 mu K-2 to l( l + 1)C-l/2 pi at l = 1000. After subtracting this contribution, our best estimate of the CMB power spectrum is derived by averaging cross-power spectra from 153 statistically independent channel pairs. The combined spectrum is cosmic variance limited to l = 400, and the signal-to-noise ratio per l-mode exceeds unity up to l = 850. For bins of width Delta l/l = 3%, the signal-to-noise ratio exceeds unity up to l = 1000. The first two acoustic peaks are seen at l = 220.8 +/- 0.7 and l = 530.9 +/- 3.8, respectively, while the first two troughs are seen at l = 412.4 +/- 1.9 and l 675.2 +/- 11.1. The rise to the third peak is unambiguous; when the WMAP data are combined with higher resolution CMB measurements, the existence of a third acoustic peak is well established. Spergel et al. use the 3 year temperature and polarization data to constrain cosmological model parameters. A simple six-parameter Lambda CDM model continues to fit CMB data and other measures of large-scale structure remarkably well. The new polarization data produce a better measurement of the optical depth to reionization, tau = 0.089 +/- 0.03. This new and tighter constraint on tau helps break a degeneracy with the scalar spectral index, which is now found to be n(s) = 0.960 +/- 0.016. If additional cosmological data sets are included in the analysis, the spectral index is found to be n(s) = 0.947 +/- 0.015. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Cornell Univ, Ithaca, NY 14853 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Sci Syst & Applicat Inc SSAI, Lanham, MD 20706 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Chicago, Dept Astrophys, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. UCLA Astron, Los Angeles, CA 90095 USA. RP Hinshaw, G (reprint author), NASA, Goddard Space Flight Ctr, Code 665, Greenbelt, MD 20771 USA. EM Gary.F.Hinshaw@nasa.gov RI Kogut, Alan/D-6293-2012; Komatsu, Eiichiro/A-4361-2011; Spergel, David/A-4410-2011; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Verde, Licia/0000-0003-2601-8770 NR 167 TC 670 Z9 675 U1 2 U2 20 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 2007 VL 170 IS 2 BP 288 EP 334 DI 10.1086/513698 PG 47 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178TD UT WOS:000247242100002 ER PT J AU Page, L Hinshaw, G Komatsu, E Nolta, MR Spergel, DN Bennett, CL Barnes, C Bean, R Dore, O Dunkley, J Halpern, M Hill, RS Jarosik, N Kogut, A Limon, M Meyer, SS Odegard, N Peiris, HV Tucker, GS Verde, L Weiland, JL Wollack, E Wright, EL AF Page, L. Hinshaw, G. Komatsu, E. Nolta, M. R. Spergel, D. N. Bennett, C. L. Barnes, C. Bean, R. Dore, O. Dunkley, J. Halpern, M. Hill, R. S. Jarosik, N. Kogut, A. Limon, M. Meyer, S. S. Odegard, N. Peiris, H. V. Tucker, G. S. Verde, L. Weiland, J. L. Wollack, E. Wright, E. L. TI Three-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Polarization analysis SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE cosmic microwave background; cosmology : observations; polarization ID COSMIC BACKGROUND-RADIATION; HIGH GALACTIC LATITUDES; ANGULAR SCALE INTERFEROMETER; INTERSTELLAR-MEDIUM EMISSION; RADIO-CONTINUUM EMISSION; SYSTEMATIC-ERROR LIMITS; GRAVITATIONAL-WAVES; POWER SPECTRUM; LINEAR-POLARIZATION; MAGNETIC-FIELD AB The Wilkinson Microwave Anisotropy Probe ( WMAP) has mapped the entire sky in five frequency bands between 23 and 94 GHz with polarization-sensitive radiometers. We present 3 year full-sky maps of the polarization and analyze them for foreground emission and cosmological implications. These observations open up a new window for understanding how the universe began and help set a foundation for future observations. WMAP observes significant levels of polarized foreground emission due to both Galactic synchrotron radiation and thermal dust emission. Synchrotron radiation is the dominant signal at l < 50 and nu less than or similar to P 40 GHz, while thermal dust emission is evident at 94 GHz. The least contaminated channel is at 61 GHz. We present a model of polarized foreground emission that captures the large angular scale characteristics of the microwave sky. After applying a Galactic mask that cuts 25.7% of the sky, we show that the high Galactic latitude rms polarized foreground emission, averaged over l = 4-6, ranges from approximate to 5 mu K at 22 GHz to less than or similar to 0.6 mu K at 61 GHz. By comparison, the levels of intrinsic CMB polarization for a Lambda CDM model with an optical depth of tau = 0.09 and assumed tensor-to-scalar ratio r = 0.3 are approximate to 0.3 mu K for E-mode polarization and approximate to 0.1 mu K for B-mode polarization. To analyze the maps for CMB polarization at l < 16, we subtract a model of the foreground emission that is based primarily on a scaling WMAP's 23 GHz map. In the foreground-corrected maps, we detect l( l + 1)C-l=< 2-6 >(EE)/2 pi = 0.086 +/- 0.29 ( mu K)(2). This is interpreted as the result of rescattering of the CMB by free electrons released during reionization at z(r) = 10.9(-2.3)(+2.7) for a model with instantaneous reionization. By computing the likelihood of just the EE data as a function of tau we find tau = 0.10 +/- 0.03. When the same EE data are used in the full six-parameter fit to all WMAP data ( TT, TE, EE), we find tau = 0.09 +/- 0.03. Marginalization over the foreground subtraction affects this value by delta(tau) < 0.01. We see no evidence for B modes, limiting them to l( l + 1)C-l=< 2-6 >(BB)/2 pi = -0.04 +/- 0.03 ( mu K)(2). We perform a template fit to the E- mode and B-mode data with an approximate model for the tensor scalar ratio. We find that the limit from the polarization signals alone is r < 2.2 ( 95% CL), where r is evaluated at k = 0.002 Mpc(-1). This corresponds to a limit on the cosmic density of gravitational waves of Omega(GW)h(2) < 5 x 10(-12). From the full WMAP analysis, we find r < 0.55 ( 95% CL) corresponding to a limit of Omega(GW)h(2) < 1 x 10(-12) ( 95% CL). The limit on r is approaching the upper bound of predictions for some of the simplest models of inflation, r similar to 0.3. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Univ Chicago, Dept Phys & Astrophys, Chicago, IL 60637 USA. Univ Chicago, KICP, Chicago, IL 60637 USA. Univ Chicago, EFI, Chicago, IL 60637 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. UCLA Astron, Los Angeles, CA 90095 USA. RP Page, L (reprint author), Princeton Univ, Dept Phys, Jadwin Hall, Princeton, NJ 08544 USA. EM page@princeton.edu RI Kogut, Alan/D-6293-2012; Komatsu, Eiichiro/A-4361-2011; Spergel, David/A-4410-2011; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Verde, Licia/0000-0003-2601-8770 NR 180 TC 579 Z9 580 U1 3 U2 24 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 JUN PY 2007 VL 170 IS 2 BP 335 EP 376 DI 10.1086/513699 PG 42 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178TD UT WOS:000247242100003 ER PT J AU Spergel, DN Bean, R Dore, O Nolta, MR Bennett, CL Dunkley, J Hinshaw, G Jarosik, N Komatsu, E Page, L Peiris, HV Verde, L Halpern, M Hill, RS Kogut, A Limon, M Meyer, SS Odegard, N Tucker, GS Weiland, JL Wollack, E Wright, EL AF Spergel, D. N. Bean, R. Dore, O. Nolta, M. R. Bennett, C. L. Dunkley, J. Hinshaw, G. Jarosik, N. Komatsu, E. Page, L. Peiris, H. V. Verde, L. Halpern, M. Hill, R. S. Kogut, A. Limon, M. Meyer, S. S. Odegard, N. Tucker, G. S. Weiland, J. L. Wollack, E. Wright, E. L. TI Three-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Implications for cosmology SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE cosmic microwave background; cosmology : observations ID COSMIC BACKGROUND IMAGER; HUBBLE-SPACE-TELESCOPE; ANGULAR POWER SPECTRUM; DIGITAL SKY SURVEY; LARGE-SCALE STRUCTURE; GALAXY REDSHIFT SURVEY; EQUATION-OF-STATE; LY-ALPHA FOREST; INFLATIONARY UNIVERSE SCENARIO; POPULATION-III STARS AB A simple cosmological model with only six parameters ( matter density, Omega(m)h(2), baryon density, Omega(b)h(2), Hubble constant, H-0, amplitude of fluctuations, sigma(8), optical depth, tau, and a slope for the scalar perturbation spectrum, n(s)) fits not only the 3 year WMAP temperature and polarization data, but also small-scale CMB data, light element abundances, large-scale structure observations, and the supernova luminosity/distance relationship. Using WMAP data only, the best-fit values for cosmological parameters for the power-law flat Lambda cold dark matter ( Lambda CDM) model are ( Omega(m)h(2), Omega(b)h(2), h, n(s), tau, sigma(s)) = (0.1277(-0.0079)(+0.0080), 0.02229 +/- 0.00073, 0.732(-0.032)(+0.031), 0.958 +/- 0.016,0.089 +/- 0.030, 0.761(-0.048)(+0.049)). The 3 year data dramatically shrink the allowed volume in this six-dimensional parameter space. Assuming that the primordial fluctuations are adiabatic with a power-law spectrum, the WMAP data alone require dark matter and favor a spectral index that is significantly less than the Harrison- Zel'dovich-Peebles scale-invariant spectrum ( n(s) = 1, r = 0). Adding additional data sets improves the constraints on these components and the spectral slope. For power-law models, WMAP data alone puts an improved upper limit on the tensor-to-scalar ratio, r(0.002) < 0.65 ( 95% CL) and the combination of WMAP and the lensing-normalized SDSS galaxy survey implies r(0.002) < 0.30 ( 95% CL). Models that suppress large-scale power through a running spectral index or a large-scale cutoff in the power spectrum are a better fit to the WMAP and small-scale CMB data than the power-law Lambda CDM model; however, the improvement in the fit to the WMAP data is only Delta(2)(chi) = 3 for 1 extra degree of freedom. Models with a running-spectral index are consistent with a higher amplitude of gravity waves. In a flat universe, the combination of WMAP and the Supernova Legacy Survey ( SNLS) data yields a significant constraint on the equation of state of the dark energy, w = -0.967(-0.072)(+0.073). If we assume w = -1, then the deviations from the critical density, Omega(K), are small: the combination of WMAP and the SNLS data implies Omega(k) = -0.011 +/- 0.012. The combination of WMAP 3 year data plus the HST Key Project constraint on H-0 implies Omega(k) = -0.014 +/- 0.017 and Omega(Lambda) = 0.716 +/- 0.055. Even if we do not include the prior that the universe is flat, by combining WMAP, large-scale structure, and supernova data, we can still put a strong constraint on the dark energy equation of state, w = -1.08 +/- 0.12. For a flat universe, the combination of WMAP and other astronomical data yield a constraint on the sum of the neutrino masses, Sigma m(nu) < 0.66 eV (95%CL). Consistent with the predictions of simple inflationary theories, we detect no significant deviations from Gaussianity in the CMB maps using Minkowski functionals, the bispectrum, trispectrum, and a new statistic designed to detect large-scale anisotropies in the fluctuations. C1 Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Cerro Tololo Interamer Observ, La Serena, Chile. Cornell Univ, Ithaca, NY 14853 USA. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Chicago, Dept Astrophys, KICP, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, KICP, Chicago, IL 60637 USA. Univ Chicago, EFI, Chicago, IL 60637 USA. Univ Penn, Dept Phys, Philadelphia, PA 19104 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Sci Syst & Applicat Inc SSAI, Lanham, MD 20706 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. UCLA Astron, Los Angeles, CA 90095 USA. RP Spergel, DN (reprint author), Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. EM dns@astro.princeton.edu RI Kogut, Alan/D-6293-2012; Komatsu, Eiichiro/A-4361-2011; Spergel, David/A-4410-2011; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Verde, Licia/0000-0003-2601-8770 NR 312 TC 4258 Z9 4265 U1 28 U2 172 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 JUN PY 2007 VL 170 IS 2 BP 377 EP 408 DI 10.1086/513700 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 178TD UT WOS:000247242100004 ER PT J AU Nazarenko, L Tausnev, N Hansen, J AF Nazarenko, Larissa Tausnev, Nickolai Hansen, James TI The North Atlantic thermohaline circulation simulated by the GISS climate model during 1970-99 SO ATMOSPHERE-OCEAN LA English DT Article ID SEA-SURFACE TEMPERATURE; HEMISPHERE ANNULAR MODE; HEAT-FLUX ANOMALIES; ATMOSPHERIC CIRCULATION; INTERDECADAL VARIATIONS; WINTER TEMPERATURES; ARCTIC OSCILLATION; RECENT DECREASE; COUPLED MODEL; OCEAN AB Evidence based on numerical simulations is presented for a strong correlation between the North Atlantic Oscillation (NAO) and the North Atlantic overturning circulation. Using an ensemble of numerical experiments with a coupled ocean-atmosphere model including both natural and anthropogenic forcings, it is shown that the weakening of the thermohaline circulation (THC) could be delayed in response to a sustained upward trend in the NAO, which was observed over the last three decades of the twentieth century, 1970-99. Overall warming and enhanced horizontal transports of heat from the tropics to the subpolar North Atlantic overwhelm the NAO-induced cooling of the upper ocean layers due to enhanced fluxes of latent and sensible heat, so that the net effect of warmed surface ocean temperatures acts to increase the vertical stability of the ocean column. However, the strong westerly winds cause increased evaporation from the ocean surface, which leads to a reduced fresh water flux over the western part of the North Atlantic. Horizontal poleward transport of salinity anomalies from, the tropical Atlantic is the major contributor to the increasing salinities in the sinking regions of the North Atlantic. The effect of positive salinity anomalies on surface ocean density overrides the opposing effect of enhanced warming of the ocean surface, which causes an increase in surface density in the Labrador Sea and in the ocean area south of Greenland. The increased density of the upper ocean layer leads to deeper convection in the Labrador Sea and in the western North Atlantic. With a lag of four years, the meridional overturning circulation of the North Atlantic shows strengthening as it adjusts to positive density anomalies and enhanced vertical mixing. During the positive NAO trend, the salinity-driven density instability in the upper ocean, due to both increased northward ocean transports of salinity and decreased atmospheric freshwater fluxes, results in a strengthening overturning circulation in the North Atlantic when the surface atmospheric temperature increases by 0.3 degrees C and the ocean surface temperature warms by 0.5 degrees to 1 degrees C. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY USA. NASA, Goddard Inst Space Studies, SSP LLC, New York, NY 10025 USA. RP Nazarenko, L (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY USA. EM nazarenko@giss.nasa.gov NR 56 TC 2 Z9 2 U1 0 U2 5 PU CMOS-SCMO PI OTTAWA PA BOX 3211, STATION D, OTTAWA, ON K1P 6H7, CANADA SN 0705-5900 EI 1480-9214 J9 ATMOS OCEAN JI Atmos.-Ocean PD JUN PY 2007 VL 45 IS 2 BP 81 EP 92 DI 10.3137/ao.450202 PG 12 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 185QM UT WOS:000247725500002 ER PT J AU Bar-Cohen, Y AF Bar-Cohen, Yoseph TI Focus issue on Biomimetics Using Electroactive Polymers as Artificial Muscles SO BIOINSPIRATION & BIOMIMETICS LA English DT Editorial Material C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM yosi@jpl.nasa.gov NR 2 TC 2 Z9 2 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1748-3182 EI 1748-3190 J9 BIOINSPIR BIOMIM JI Bioinspir. Biomim. PD JUN PY 2007 VL 2 IS 2 DI 10.1088/1748-3190/2/2/E01 PG 3 WC Engineering, Multidisciplinary; Materials Science, Biomaterials; Robotics SC Engineering; Materials Science; Robotics GA V06BX UT WOS:000207170200001 ER PT J AU Marasco, RJ Goodman, D Grimes, CB Lawson, PW Punt, AE Quinn, TJ AF Marasco, Richard J. Goodman, Daniel Grimes, Churchill B. Lawson, Peter W. Punt, Andre E. Quinn, Terrance J., II TI Ecosystem-based fisheries management: some practical suggestions SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID COHO ONCORHYNCHUS-KISUTCH; POPULATION; PACIFIC; ALASKA; SEA; CLIMATE; MODELS; SALMON; SUSTAINABILITY; PREDATION AB Globally, there is increased scientific and public interest in the concept of ecosystem-based fisheries management (EBFM). This trend is fueled by a widespread perception that large-scale fishing operations are powerful forces altering the structure and function of marine ecosystems. It is acknowledged that management needs to better account for variations in ocean productivity, stock structure, and changing social values. Many countries are contemplating how to improve ocean fishery management. In the United States, fishery management bodies are experiencing pressure to undertake the daunting task of moving from their current single-species management plans to EBFM. Impediments include lack of a clear definition of EBFM, what it entails, or how to proceed. In this paper, characteristics of fishery management that are unique to EBFM are identified. The transition to EBFM needs to be evolutionary rather than revolutionary. A course of action is outlined that can be used to guide this transition. Modeling approaches and metrics useful for planning, implementing, and evaluating EBFM are discussed, with particular emphasis on management strategy evaluation. C1 Alaska Fisheries Sci Ctr, Resource Ecol & Fisheries Management Div, Woodinville, WA 98077 USA. Montana State Univ, Dept Ecol, Environm Stat Grp, Bozeman, MT 59717 USA. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fisheries Ecol Div, Santa Cruz, CA 95060 USA. Univ Washington, Sch Aquat & Fishery Sci, Seattle, WA 98195 USA. CSIRO Marine & Atmospher Res, Hobart, Tas 7001, Australia. Univ Alaska, Sch Fisheries & Ocean Sci, Juneau, AK 99801 USA. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Newport, OR 97365 USA. EM richmarasco@hotmail.com OI Punt, Andre/0000-0001-8489-2488 NR 73 TC 84 Z9 87 U1 1 U2 31 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD JUN PY 2007 VL 64 IS 6 BP 928 EP 939 DI 10.1139/F07-062 PG 12 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 197RD UT WOS:000248572900008 ER PT J AU Peddle, DR Johnson, RL Cihlar, J Leblanc, SG Chen, JM Hall, FG AF Peddle, Derek R. Johnson, Ryan L. Cihlar, Josef Leblanc, Sylvain G. Chen, Jing M. Hall, Forrest G. TI Physically based inversion modeling for unsupervised cluster labeling, independent forest classification, and LAI estimation using MFM-,5-Scale SO CANADIAN JOURNAL OF REMOTE SENSING LA English DT Article ID RESOLUTION SATELLITE DATA; MULTIPLE-FORWARD-MODE; LEAF-AREA INDEX; LAND-COVER; REFLECTANCE MODEL; DIRECTIONAL REFLECTANCE; BIOPHYSICAL STRUCTURE; BOREAL FOREST; METHODOLOGY; CANOPY AB Unsupervised clustering is important for regional- to national-scale forest inventories where supervised training data are impractical or unavailable. However, labeling clusters in terms of land-cover classes can be labour intensive and problematic, and clustering and related methods do not provide biophysical-structural information (BSI). Canopy reflectance models such as 5-Scale are powerful forest remote sensing tools; however, 5-Scale can only be run in forward mode and is not invertible to obtain the required forest information. This problem was solved using multiple-forward-mode (MFM) coupled with 5-Scale to enable MFM-5-Scale inversion of land cover and BSI using a look-up table (MFM-LUT) approach that matches satellite image reflectance values with modeled reflectance values that have associated land cover and BSI, such as density, leaf area index (LAI), and crown dimensions, as well as subpixel-scale component fractions. MFM requires no training data or a priori BSI and can optionally be stratified (generalized) by species, structural, hierarchical, mixed forest, and other class definitions. In this paper, MFM-5-Scale was used with Landsat thematic mapper (TM) imagery at the Boreal Ecosystem-Atmosphere Study (BOREAS) southern study area (SSA) modeling subarea (MSA) in Saskatchewan, Canada. MFM-5-Scale was used to label unsupervised cluster sets (n = 17 and 97) from a previous landcover classification by progressive generalization (CPG), with the best results obtained from independent, stand-alone MFM classification (87%, 76%, and 71% for the three hierarchies of 16 forest type, species, and density classes) validated against the provincial (SERM) forest inventory map and also compared with a standard maximum likelihood (ML) classification. Further, MFM-5-Scale estimated LAI at 24 BOREAS plots within +/- 0.57 LAI compared with ground-based tracing radiation and architecture of canopies (TRAC) LAI validation data. BSI is not provided by CPG clustering or ML. Based on this and other studies, we conclude that MFM provides an inversion modeling context for sophisticated forest radiative transfer models to retrieve a higher level of land cover and BSI, with detailed LUTs providing a rich set of forest information suitable for query, analysis, and follow-on simulation studies. These methods can augment existing regional- to nationalscale remote sensing based inventories by providing a robust cluster labeling and BSI capability or can provide stand-alone capabilities over a variety of applications and scales. C1 Univ Lethbridge, Dept Geog, Lethbridge, AB T1K 3M4, Canada. Canada Ctr Remote Sensing, Environm Monitoring Sect, Ottawa, ON K1A 0Y7, Canada. Univ Toronto, Dept Geog, Toronto, ON M5S 3G3, Canada. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Peddle, DR (reprint author), Univ Lethbridge, Dept Geog, 4401 Univ Dr W, Lethbridge, AB T1K 3M4, Canada. EM derek.peddle@uleth.ca NR 45 TC 16 Z9 17 U1 0 U2 6 PU CANADIAN AERONAUTICS SPACE INST PI KANATA PA 350 TERRY FOX DR, STE 104, KANATA, ON K2K 2W5, CANADA SN 0703-8992 J9 CAN J REMOTE SENS JI Can. J. Remote Sens. PD JUN PY 2007 VL 33 IS 3 BP 214 EP 225 PG 12 WC Remote Sensing SC Remote Sensing GA 196BY UT WOS:000248457900007 ER PT J AU Liu, JY Wen, JH Wang, YF Wang, WL Cathso, BM Jezek, KC AF Liu Jiying Wen Jiahong Wang Yafeng Wang Weili Cathso, Beata M. Jezek, Kenneth C. TI Development and applications of Dome A-DEM in Antairctic ice sheet SO CHINESE GEOGRAPHICAL SCIENCE LA English DT Article DE Dome A; ICESat GLAS; Cokriging; DEM; Antarctica ID MODEL AB Dome A, the highest dome of East Antarctic Ice Sheet, is being an area focused by international Antarctic community after Chinese Antarctic Expedition finally reached there in 2005, and with the ongoing International Polar Year (IPY) during August 2007. In this paper two data processing methods are used together to generate two 100-m cell size digital elevation models (DEMs) of the Dome A region (Dome A-DEM) by using Cokriging method to interpolate the ICESat GLAS data, with Ihde-DEM as a constraint. It provides fundamental data to glaciological and geophysical investigation in this area. The Dome A-DEM was applied to determining the ice-sheet surface elevations and coordinates of the south and north summits, defining boundaries of basins and ice flowlines, deducing subglacial topography, and mapping surface slope and aspect in Dome A region. The DEM shows there are two (north and south) summits in Dome A region. The coordinate and the surface elevation of the highest point (the north summit) are 80 degrees 21'29.86 '' S, 77 degrees 21'50.29 '' E and 4092.71 +/- 1.43m, respectively. The ice thickness and sub-ice bedrock elevation at north summit are 2420m and 1672m, respectively. Dome A region contains four drainage basins that meet together near the south summit. Ice flowlines, slope and aspect in detail are also derived using the DEM. C1 [Liu Jiying; Wen Jiahong; Wang Yafeng] Shanghai Normal Univ, Dept Geog, Shanghai 200234, Peoples R China. [Wang Weili] NASA, Goddard Space Flight Ctr, SGT, Greenbelt, MD 20771 USA. [Cathso, Beata M.; Jezek, Kenneth C.] Ohio State Univ, Byrd Polar Res Ctr, Columbus, OH 43210 USA. RP Wen, JH (reprint author), Shanghai Normal Univ, Dept Geog, Shanghai 200234, Peoples R China. EM jhwen@shnu.edu.cn NR 20 TC 2 Z9 3 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1002-0063 J9 CHINESE GEOGR SCI JI Chin. Geogr. Sci. PD JUN PY 2007 VL 17 IS 2 BP 160 EP 165 DI 10.1007/s11769-007-0160-4 PG 6 WC Environmental Sciences SC Environmental Sciences & Ecology GA 284LK UT WOS:000254707700008 ER PT J AU Skulan, J Bullen, T Anbar, AD Puzas, JE Shackelford, L LeBlanc, A Smith, SM AF Skulan, Joseph Bullen, Thomas Anbar, Ariel D. Puzas, J. Edward Shackelford, Linda LeBlanc, Adrian Smith, Scott M. TI Natural calcium isotopic composition of urine as a marker of bone mineral balance SO CLINICAL CHEMISTRY LA English DT Article ID OSTEOPOROSIS; METABOLISM; KINETICS; FRACTIONATION; MONITOR; CA-41 AB Background :We investigated whether changes in the natural isotopic composition of calcium in human urine track changes in net bone mineral balance, as predicted by a model of calcium isotopic behavior in vertebrates. If so, isotopic analysis of natural urine or blood calcium could be used to monitor short-term changes in bone mineral balance that cannot be detected with other techniques. Methods: Calcium isotopic compositions are expressed as delta Ca-44, or the difference in parts per thousand between the Ca-44/Ca-40 of a sample and the Ca-44/Ca-40 of a standard reference material. 644 Ca. was measured in urine samples from 10 persons who participated in a study of the effectiveness of countermeasures to bone loss in spaceflight, in which 17 weeks of bed rest was used to induce bone loss. Study participants were assigned to 1 of 3 treatment groups: controls received no treatment, one treatment group received alendronate, and another group performed resistive exercise. Measurements were made on urine samples collected before, at 2 or 3 points during, and after bed rest. Results: Urine 844 Ca values during bed rest were lower in controls than in individuals treated with alendronate (P <0.05, ANOVA) or exercise (P <0.05), and lower than the control group baseline (P <0.05, t-test). Results were consistent with the model and with biochemical and bone mineral density data. Conclusion: Results confirm the predicted relationship between bone mineral balance and calcium isotopes, suggesting that calcium isotopic analysis of urine might be refined into a clinical and research tool. (C) 2007 American Association for Clinical Chemistry. C1 Univ Wisconsin, Dept Geol & Geophys, Madison, WI 53706 USA. US Geol Survey, Branch Reg Res, Water Resources Discipline, Menlo Pk, CA 94025 USA. Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. Arizona State Univ, Sch Chem & Biochem, Tempe, AZ 85287 USA. Univ Rochester, Sch Med & Dent, Dept Orthopaed, Rochester, NY 14627 USA. NASA, Johnson Space Ctr, Human Adaptat & Countermeasures Div, Houston, TX 77058 USA. Baylor Coll Med, Dept Med, Houston, TX 77030 USA. RP Skulan, J (reprint author), Univ Wisconsin, Dept Geol & Geophys, 1215 W Dayton St, Madison, WI 53706 USA. EM jlskulan@geology.wisc.edu FU NIEHS NIH HHS [P30 ES 01247-24] NR 19 TC 38 Z9 39 U1 2 U2 14 PU AMER ASSOC CLINICAL CHEMISTRY PI WASHINGTON PA 2101 L STREET NW, SUITE 202, WASHINGTON, DC 20037-1526 USA SN 0009-9147 J9 CLIN CHEM JI Clin. Chem. PD JUN PY 2007 VL 53 IS 6 BP 1155 EP 1158 DI 10.1373/clinchem.2006.080143 PG 4 WC Medical Laboratory Technology SC Medical Laboratory Technology GA 172UP UT WOS:000246830300026 PM 17463176 ER PT J AU Tavana, M Smither, JW Anderson, RV AF Tavana, Madjid Smither, James W. Anderson, Ralph V. TI D-side: A facility and workforce planning group multi-criteria decision support system for Johnson Space Center SO COMPUTERS & OPERATIONS RESEARCH LA English DT Article DE NASA; multi-criteria decision making; decision support system; AHP; Euclidean distance; 3-D Modeling; facility planning; workforce planning ID ANALYTIC HIERARCHY PROCESS; RELIABILITY; TECHNOLOGY AB "To understand and protect our home planet, to explore the universe and search for life, and to inspire the next generation of explorers" is NASA's mission. The Systems Management Office at Johnson Space Center (JSC) is searching for methods to effectively manage the Center's resources to meet NASA's mission. D-Side is a group multi-criteria decision support system (GMDSS) developed to support facility decisions at JSC. D-Side uses a series of sequential and structured processes to plot facilities in a three-dimensional (3-D) graph on the basis of each facility's alignment with NASA's mission and goals, the extent to which other facilities are dependent on the facility, and the dollar value of capital investments that have been postponed at the facility relative to the facility's replacement value. A similarity factor rank orders facilities based on their Euclidean distance from Ideal and Nadir points. These similarity factors are then used to allocate capital improvement resources across facilities. We also present a parallel model that can be used to support decisions concerning allocation of human resources investments across workforce units. Finally, we present results from a pilot study where 12 experienced facility managers from NASA used D-Side and the organization's current approach to rank order and allocate funds for capital improvement across 20 facilities. Users evaluated D-Side favorably in terms of ease of use, the quality of the decision-making process, decision quality, and overall value-added. Their evaluations of D-Side were significantly more favorable than their evaluations of the current approach. (c) 2005 Elsevier Ltd. All rights reserved. C1 La Salle Univ, Dept Management, Philadelphia, PA 19141 USA. NASA, Lyndon B Johnson Space Ctr, Syst Management Off, Houston, TX 77058 USA. RP Tavana, M (reprint author), La Salle Univ, Dept Management, 1900 W Olney Ave, Philadelphia, PA 19141 USA. EM tavana@lasalle.edu; smither@lasalle.edu; ralph.v.anderson@nasa.gov NR 41 TC 9 Z9 9 U1 14 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0305-0548 J9 COMPUT OPER RES JI Comput. Oper. Res. PD JUN PY 2007 VL 34 IS 6 BP 1646 EP 1673 DI 10.1016/j.cor.2005.06.020 PG 28 WC Computer Science, Interdisciplinary Applications; Engineering, Industrial; Operations Research & Management Science SC Computer Science; Engineering; Operations Research & Management Science GA 122YS UT WOS:000243264100009 ER PT J AU Tischler, M Garcia, M Peters-Lidard, C Moran, MS Miller, S Thoma, D Kumar, S Geiger, J AF Tischler, M. Garcia, M. Peters-Lidard, C. Moran, M. S. Miller, S. Thoma, D. Kumar, S. Geiger, J. TI A GIS framework for surface-layer soil moisture estimation combining satellite radar measurements and land surface modeling with soil physical property estimation SO ENVIRONMENTAL MODELLING & SOFTWARE LA English DT Article DE GIS; ARMS; model integration; soil moisture; land information system; parameter estimation ID SOUTHERN GREAT-PLAINS; IMPROVED CALIBRATION; HYDROLOGIC-MODELS; MONSOON 90; MICROWAVE; INFORMATION; SYSTEM; SAR; MANAGEMENT; WATER AB A GIS framework, the Army Remote Moisture System (ARMS), has been developed to link the Land Information System (LIS), a high performance land surface modeling and data assimilation system, with remotely sensed measurements of soil moisture to provide a high resolution estimation of soil moisture in the near surface. ARMS uses available soil (soil texture, porosity, K-sat), land cover (vegetation type, LAI, Fraction of Greenness), and atmospheric data (Albedo) in standardized vector and raster GIS data formats at multiple scales, in addition to climatological forcing data and precipitation. PEST (Parameter EStimation Tool) was integrated into the process to optimize soil porosity and saturated hydraulic conductivity (A(sat)), using the remotely sensed measurements, in order to provide a more accurate estimate of the soil moisture. The modeling process is controlled by the user through a graphical interface developed as part of the ArcMap component of ESRI ArcGIS. Published by Elsevier Ltd. C1 USDA ARS, Walnut Gulch Expt Watershed, SW Watershed Res Ctr, Tucson, AZ 85719 USA. Univ Wyoming, Dept Renewable Resources, Laramie, WY 82071 USA. NASA, Goddard Space Flight Ctr, Univ Maryland Baltimore Cty, Greenbelt, MD 20771 USA. USA, Corps Engineers, Engn Res & Dev Ctr, Topog Engn Ctr, Alexandria, VA 22312 USA. RP Moran, MS (reprint author), USDA ARS, Walnut Gulch Expt Watershed, SW Watershed Res Ctr, 2000 E Allen Rd, Tucson, AZ 85719 USA. EM michael.a.tischler@erdc.usace.army.mil; smoran@tucson.ars.ag.gov RI Peters-Lidard, Christa/E-1429-2012; Garcia, Matthew/K-9286-2013; Kumar, Sujay/B-8142-2015 OI Peters-Lidard, Christa/0000-0003-1255-2876; Garcia, Matthew/0000-0002-9637-4204; NR 45 TC 16 Z9 16 U1 2 U2 18 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1364-8152 J9 ENVIRON MODELL SOFTW JI Environ. Modell. Softw. PD JUN PY 2007 VL 22 IS 6 BP 891 EP 898 DI 10.1016/j.envsoft.2006.05.022 PG 8 WC Computer Science, Interdisciplinary Applications; Engineering, Environmental; Environmental Sciences SC Computer Science; Engineering; Environmental Sciences & Ecology GA 141SJ UT WOS:000244598700012 ER PT J AU Healy, PJ Ledyard, JO Noussair, C Thronson, H Ulrich, P Varsi, G AF Healy, Paul J. Ledyard, John O. Noussair, Charles Thronson, Harley Ulrich, Peter Varsi, Giulio TI Contracting inside an organization: An experimental study SO EXPERIMENTAL ECONOMICS LA English DT Article DE mechanism design; cost sharing; moral hazard; NASA ID PRICE; INCENTIVES; ALLOCATION; COSTS AB In this paper we propose and test a contracting mechanism, Multi-Contract Cost Sharing (MCCS), for use in the management of a sequence of projects. The mechanism is intended for situations where (1) the contractor knows more about the true costs of various projects than does the contracting agency (adverse selection), and (2) unobservable effort on the part of the contractor may lead to cost reductions (moral hazard). The proposed process is evaluated in an experimental environment that includes the essential economic features of the NASA process for the acquisition of Space Science Strategy missions. The environment is complex and the optimal mechanism is unknown. The design of the MCCS mechanism is based on the optimal contract for a simpler related environment. We compare the performance of the proposed process to theoretical benchmarks and to an implementation of the current NASA 'cost cap' procurement process. The data indicate that the proposed MCCS process generates significantly higher value per dollar spent than using cost caps, because it allocates resources more efficiently among projects and provides greater incentives to engage in cost-reducing innovations. C1 Carnegie Mellon Univ, Tepper Sch Business, Pittsburgh, PA 15213 USA. CALTECH, Div Humanities & Social Sci, Pasadena, CA 91125 USA. Emory Univ, Dept Econ, Atlanta, GA 30322 USA. NASA Headquarters, Off Space Sci, Washington, DC USA. Purdue Univ, W Lafayette, IN 47907 USA. RP Healy, PJ (reprint author), Carnegie Mellon Univ, Tepper Sch Business, Pittsburgh, PA 15213 USA. EM phealy@cmu.edu; jledyard@hss.caltech.edu; cnoussa@emory.edu; hthronso@hq.nasa.gov; pjulrich@radix.net; gvarsi@hq.nasa.gov OI Healy, Paul/0000-0002-2580-7375 NR 32 TC 2 Z9 2 U1 0 U2 8 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1386-4157 J9 EXP ECON JI Exp. Econ. PD JUN PY 2007 VL 10 IS 2 BP 143 EP 167 DI 10.1007/s10683-006-9137-x PG 25 WC Economics SC Business & Economics GA 164HX UT WOS:000246225500003 ER PT J AU Joshi, R Holzmann, GJ AF Joshi, Rajeev Holzmann, Gerard J. TI A mini challenge: build a verifiable filesystem SO FORMAL ASPECTS OF COMPUTING LA English DT Article; Proceedings Paper CT Meeting on Verified Software Theories, Tools and Experiments (VSTTE) CY NOV, 2005 CL ETH, Zurich, SWITZERLAND HO ETH DE verification grand challenge; filesystem design; formal verification AB We propose tackling a "mini challenge" problem: a nontrivial verification effort that can be completed in 2-3 years, and will help establish notational standards, common formats, and libraries of benchmarks that will be essential in order for the verification community to collaborate on meeting Hoare's 15-year verification grand challenge. We believe that a suitable candidate for such a mini challenge is the development of a filesystem that is verifiably reliable and secure. The paper argues why we believe a filesystem is the right candidate for a mini challenge and describes a project in which we are building a small embedded filesystem for use with flash memory. C1 CALTECH, Jet Prop Lab, Lab Reliable Software, Pasadena, CA 91109 USA. RP Joshi, R (reprint author), CALTECH, Jet Prop Lab, Lab Reliable Software, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Rajeev.Joshi@jpl.nasa.gov; Gerard.J.Holzmann@jpl.nasa.gov NR 4 TC 24 Z9 24 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0934-5043 J9 FORM ASP COMPUT JI Form. Asp. Comput. PD JUN PY 2007 VL 19 IS 2 BP 269 EP 272 DI 10.1007/s00165-006-0022-3 PG 4 WC Computer Science, Software Engineering SC Computer Science GA 178RY UT WOS:000247239000008 ER PT J AU Hornby, GS Kumar, S Jacob, C AF Hornby, Gregory S. Kumar, Sanjeev Jacob, Christian TI Editorial introduction to the special issue on developmental systems SO GENETIC PROGRAMMING AND EVOLVABLE MACHINES LA English DT Editorial Material C1 NASA, Ames Res Ctr, Univ Affiliated Res Ctr, UC Santa Cruz, Moffett Field, CA 94035 USA. Cornell Univ, Sibley Sch Mech & Aerosp Engn, Ithaca, NY 14853 USA. Univ Calgary, Dept Comp Sci, Calgary, AB T2N 1N4, Canada. RP Hornby, GS (reprint author), NASA, Ames Res Ctr, Univ Affiliated Res Ctr, UC Santa Cruz, Mail Stop 269-3, Moffett Field, CA 94035 USA. EM hornby@email.arc.nasa.gov; sk525@cornell.edu; jacob@cpsc.ucalgary.ca NR 2 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1389-2576 J9 GENET PROGRAM EVOL M JI Genet. Program. Evol. Mach. PD JUN PY 2007 VL 8 IS 2 BP 111 EP 113 DI 10.1007/sIO710-007-9026-x PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA 211YD UT WOS:000249559100001 ER PT J AU Emanuelsson, O Nagalakshmi, U Zheng, DY Rozowsky, JS Urban, AE Du, J Lian, Z Stolc, V Weissman, S Snyder, M Gerstein, MB AF Emanuelsson, Olof Nagalakshmi, Ugrappa Zheng, Deyou Rozowsky, Joel S. Urban, Alexander E. Du, Jiang Lian, Zheng Stolc, Viktor Weissman, Sherman Snyder, Michael Gerstein, Mark B. TI Assessing the performance of different high-density tiling microarray strategies for mapping transcribed regions of the human genome SO GENOME RESEARCH LA English DT Article ID FACTOR-BINDING SITES; TRANSCRIPTIONAL ACTIVITY; OLIGONUCLEOTIDE ARRAYS; DNA MICROARRAYS; CHIP-CHIP; PLATFORMS; SEQUENCES; HUMAN-CHROMOSOME-21; CHROMOSOME-22; TECHNOLOGIES AB Genomic tiling microarrays have become a popular tool for interrogating the transcriptional activity of large regions of the genome in an unbiased fashion. There are several key parameters associated with each tiling experiment ( e. g., experimental protocols and genomic tiling density). Here, we assess the role of these parameters as they are manifest in different tiling-array platforms used for transcription mapping. First, we analyze how a number of published tiling-array experiments agree with established gene annotation on human chromosome 22. We observe that the transcription detected from high-density arrays correlates substantially better with annotation than that from other array types. Next, we analyze the transcription-mapping performance of the two main high-density oligonucleotide array platforms in the ENCODE regions of the human genome. We hybridize identical biological samples and develop several ways of scoring the arrays and segmenting the genome into transcribed and nontranscribed regions, with the aim of making the platforms most comparable to each other. Finally, we develop a platform comparison approach based on agreement with known annotation. Overall, we find that the performance improves with more data points per locus, coupled with statistical scoring approaches that properly take advantage of this, where this larger number of data points arises from higher genomic tiling density and the use of replicate arrays and mismatches. While we do find significant differences in the performance of the two high-density platforms, we also find that they complement each other to some extent. Finally, our experiments reveal a significant amount of novel transcription outside of known genes, and an appreciable sample of this was validated by independent experiments. C1 Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA. Yale Univ, Dept Mol Cellular & Dev Biol, New Haven, CT 06520 USA. Yale Univ, Sch Med, Dept Genet, New Haven, CT 06520 USA. Yale Univ, Dept Comp Sci, New Haven, CT 06520 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Snyder, M (reprint author), Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA. EM michael.snyder@yale.edu; mark.gerstein@yale.edu OI Zheng, Deyou/0000-0003-4354-5337; Rozowsky, Joel/0000-0002-3565-0762 FU NHGRI NIH HHS [1U01HG003156-01, U01 HG003156] NR 40 TC 12 Z9 16 U1 0 U2 2 PU COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT PI WOODBURY PA 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2924 USA SN 1088-9051 J9 GENOME RES JI Genome Res. PD JUN PY 2007 VL 17 IS 6 BP 886 EP 897 DI 10.1101/gr.5014606 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 178NH UT WOS:000247226900020 PM 17119069 ER PT J AU Euskirchen, GM Rozowsky, JS Wei, CL Lee, WH Zhang, ZDD Hartman, S Emanuelsson, O Stolc, V Weissman, S Gerstein, MB Ruan, YJ Snyder, M AF Euskirchen, Ghia M. Rozowsky, Joel S. Wei, Chia-Lin Lee, Wah Heng Zhang, Zhengdong D. Hartman, Stephen Emanuelsson, Olof Stolc, Viktor Weissman, Sherman Gerstein, Mark B. Ruan, Yijun Snyder, Michael TI Mapping of transcription factor binding regions in mammalian cells by ChIP: Comparison of array- and sequencing-based technologies SO GENOME RESEARCH LA English DT Article ID EMBRYONIC STEM-CELLS; CHROMATIN-IMMUNOPRECIPITATION; GENE-EXPRESSION; OLIGONUCLEOTIDE ARRAYS; MICROARRAY ANALYSIS; CDNA MICROARRAY; HUMAN GENOME; SITES; HUMAN-CHROMOSOME-22; IDENTIFICATION AB Recent progress in mapping transcription factor (TF) binding regions can largely be credited to chromatin immunoprecipitation (ChIP) technologies. We compared strategies for mapping TF binding regions in mammalian cells using two different ChIP schemes: ChIP with DNA microarray analysis (ChIP-chip) and ChIP with DNA sequencing (ChIP-PET). We first investigated parameters central to obtaining robust ChIP-chip data sets by analyzing STAT1 targets in the ENCODE regions of the human genome, and then compared ChIP-chip to ChIP-PET. We devised methods for scoring and comparing results among various tiling arrays and examined parameters such as DNA microarray format, oligonucleotide length, hybridization conditions, and the use of competitor Cot-1 DNA. The best performance was achieved with high-density oligonucleotide arrays, oligonucleotides >= 50 bases (b), the presence of competitor Cot-1 DNA and hybridizations conducted in microfluidics stations. When target identification was evaluated as a function of array number, 80% - 86% of targets were identified with three or more arrays. Comparison of ChIP-chip with ChIP-PET revealed strong agreement for the highest ranked targets with less overlap for the low ranked targets. With advantages and disadvantages unique to each approach, we found that ChIP-chip and ChIP-PET are frequently complementary in their relative abilities to detect STAT1 targets for the lower ranked targets; each method detected validated targets that were missed by the other method. The most comprehensive list of STAT1 binding regions is obtained by merging results from ChIP-chip and ChIP-sequencing. Overall, this study provides information for robust identification, scoring, and validation of TF targets using ChIP-based technologies. C1 Yale Univ, Dept Mol Cellular & Dev Biol, New Haven, CT 06520 USA. Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA. Genome Inst Singapore, Singapore 138672, Singapore. Yale Univ, Sch Med, Dept Genet, New Haven, CT 06520 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Snyder, M (reprint author), Yale Univ, Dept Mol Cellular & Dev Biol, New Haven, CT 06520 USA. EM michael.snyder@yale.edu OI Rozowsky, Joel/0000-0002-3565-0762 FU NHGRI NIH HHS [U01 HG003156, HG003156] NR 41 TC 130 Z9 133 U1 3 U2 12 PU COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT PI WOODBURY PA 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2924 USA SN 1088-9051 J9 GENOME RES JI Genome Res. PD JUN PY 2007 VL 17 IS 6 BP 898 EP 909 DI 10.1101/gr.5583007 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 178NH UT WOS:000247226900021 PM 17568005 ER PT J AU Argus, DF AF Argus, Donald F. TI Defining the translational velocity of the reference frame of Earth SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE climate; crustal deformation; geodesy; geodynamics; glacial rebound; global positioning system; plate tectonics ID TERRESTRIAL REFERENCE FRAME; BASE-LINE INTERFEROMETRY; CURRENT PLATE MOTIONS; SURFACE LOADING DATA; GEOPHYSICAL INTERPRETATION; GEOCENTER VARIATIONS; GPS MEASUREMENTS; TIME-SERIES; DEFORMATION; MODEL AB Earth's centre is fundamental to geodesy and geoscience because motions of sites on the surface are estimated relative to it. International Terrestrial Reference Frames ITRF2000 and ITRF2005 are defined by the centre of mass of Earth's system (CM), consisting of solid Earth, the ice sheets, the oceans, and the atmosphere. Satellite LAGEOS rotates about CM; satellite laser ranging (SLR) is used to estimate the velocity of CM relative to sites on the surface. However, ITRF2000 and ITRF2005 differ by 1.8 mm yr(-1), suggesting that the velocity of CM is constrained poorly by SLR. In this study, we define Earth's reference frame with the centre of mass of solid Earth (CE). Site velocities estimated using SLR, VLBI, GPS and DORIS are corrected for a postglacial rebound model and inverted for the rotational velocities of the plates and the rotational and translational velocities of the four space techniques. Because the postglacial rebound predictions are relative to CE, the velocity of CE relative to sites on the surface is estimated. Because the input SLR site velocities are relative to CM, the output SLR translational velocity is the velocity of CM relative to CE. The estimated velocity of CE does not depend strongly on the postglacial rebound model corrected for. Equal within uncertainties and having a root mean square of 0.5 mm yr(-1) are estimates of the velocity of CE determined assuming that plate interiors are deforming radially as predicted by three postglacial rebound models and an estimate of the velocity of CE determined assuming that parts of plate interiors neither beneath nor along the margins of the late Pleistocene ice sheets are not deforming laterally. The velocity of CE equals within uncertainties (probability greater than 5 per cent) the velocity of CM in ITRF2000. The velocity of CE differs significantly (0.05 per cent probability) from the velocity of CM in ITRF2005. Earth's reference frame (and, we believe, ITRF's) should be defined with the tightly constrained velocity of CE, not with the poorly constrained velocity of CM. Because CE is believed to be moving relative to CM no faster than 0.5 mm yr(-1), the velocity of CE estimated in this study is likely to be nearer the true velocity of CM than is the velocity of CM estimated using SLR. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Argus, DF (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Donald.F.Argus@jpl.nasa.gov RI Argus, Donald/F-7704-2011 NR 43 TC 54 Z9 55 U1 1 U2 6 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X EI 1365-246X J9 GEOPHYS J INT JI Geophys. J. Int. PD JUN PY 2007 VL 169 IS 3 BP 830 EP 838 DI 10.1111/j.1365-246X.2007.03344.x PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 178FA UT WOS:000247205400004 ER PT J AU Schoeberl, MR AF Schoeberl, Mark R. TI A model for the behavior of beta-hCG after evacuation of hydatidiform moles SO GYNECOLOGIC ONCOLOGY LA English DT Article DE hCG; hydatidiform moles; gestational trophoblastic disease; persistent trophoblastic disease; trophoblastic disease ID PERSISTENT TROPHOBLASTIC DISEASE; REGRESSION CURVE; DIAGNOSIS; RISK AB Objectives. The objective of this study is to develop a physical model of the behavior of beta-hCG following the complete evacuation of a hydatidiform mole. Because hCG is an excellent marker for continued tropboblastic activity, the model can be used for early detection of persistent sites. Method. The model was developed from analysis of the post surgical hCG decrease in a patient with Stage III gestational trophoblastic neoplasia. As found in previous molar pregnancy studies, hCG follows a log-linear decrease after resolution. In contrast to those studies, however, we assume that the decrease can-be explained by the dilution of the residual hCG from two different tissue reservoirs, a tissue reservoir with a half-life of similar to 4 days and a reservoir with a longer half-life, in this case similar to 18 days. Results. Simple dilution of two tissue reservoirs explains behavior of hCG following tumor removal. The model also explains the hCG decrease in a larger study of Japanese and Dutch women following the evacuation of uneventful hydatidiform moles. Conclusions. Following an initial rapid drop in hCG after resolution of the mole, the patient should experience a slower drop associated with the dilution of residual hCG in the deep tissue reservoir. This is normal. The physical model suggests that even earlier detection of chemotherapy resistant persistent trophoblastic disease is possible if the patient's decrease in hCG is slower than a log-linear fit to the patient's previous data. The results also suggest an alternative approach to processing patient statistics in analysis of carcinomas with large variations in the tumor marker concentrations. Published by Elsevier Inc. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Schoeberl, MR (reprint author), NASA, Goddard Space Flight Ctr, Code 613-3, Greenbelt, MD 20771 USA. EM mark.r.schoeberl@nasa.gov NR 9 TC 4 Z9 5 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 0090-8258 J9 GYNECOL ONCOL JI Gynecol. Oncol. PD JUN PY 2007 VL 105 IS 3 BP 776 EP 779 DI 10.1016/j.ygyno.2007.02.021 PG 4 WC Oncology; Obstetrics & Gynecology SC Oncology; Obstetrics & Gynecology GA 172PG UT WOS:000246815700035 PM 17395254 ER PT J AU Heldmann, JL Carlsson, E Johansson, H Mellon, MT Toon, OB AF Heldmann, Jennifer L. Carlsson, Ella Johansson, Henrik Mellon, Michael T. Toon, Owen B. TI Observations of martian gullies and constraints on potential formation mechanisms II. The northern hemisphere SO ICARUS LA English DT Article DE Mars; geological processes ID MARS ORBITER CAMERA; LIQUID WATER; THERMAL HISTORY; TERRESTRIAL PLANETS; GROUND ICE; EVOLUTION; CHRONOLOGY; SEEPAGE; BRINES; FLOWS AB The formation process(es) responsible for creating the observed geologically recent gully features on Mars has remained the subject of intense debate since their discovery. We present new data and analysis of northern hemisphere gullies from Mars Global Surveyor data which is used to test the various proposed mechanisms of gully formation. We located 137 Mars Orbiter Camera (MOC) images in the northern hemisphere that contain clear evidence of gully landforms and analyzed these images in combination with Mars Orbiter Laser Altimeter (MOLA) and Thermal Emission Spectrometer (TES) data to provide quantitative measurements of numerous gully characteristics. Parameters we measured include apparent source depth and distribution, vertical and horizontal dimensions, slopes, orientations, and present-day characteristics that affect local ground temperatures. Northern hemisphere gullies are clustered in Arcadia Planitia, Tempe Terra, Acidalia Planitia, and Utopia Planitia. These gullies form in craters (84%), knobby terrain (4%), valleys (3%), other/unknown terrains (9%) and are found on all slope orientations although the majority of gullies are equator-facing. Most gullies (63%) are associated with competent rock strata, 26% are not associated with strata, and 11% are ambiguous. Assuming thermal conductivities derived from TES measurements as well as modeled surface temperatures, we find that 95% of the gully alcove bases with adequate data coverage lie at depths where subsurface temperatures are greater than 273 K and 5% of the alcove bases lie within the solid water regime. The average alcove length is 470 m and the average channel length is 690 m. Based on a comparison of measured gully features with predictions from the various models of gully formation, we find that models involving carbon dioxide, melting ground ice in the upper few meters of the soil, dry landslide, and surface snowmelt are the least likely to describe the formation of the martian gullies. Although some discrepancies still exist between prediction and observation, the shallow and deep aquifer models remain as the most plausible theories. Interior processes involving subsurface fluid sources are generally favored over exogenic processes such as wind and snowfall for explaining the origin of the martian gullies. These findings gleaned from the northern hemisphere data are in general agreement with analyses of gullies in the southern hemisphere [Heldmann, JL., Mellon, M.T., 2004. Icarus 168, 285-304]. Published by Elsevier Inc. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Lulea Univ Technol, Div Phys, SE-97187 Lulea, Sweden. Swedish Inst Space Phys, SE-98128 Kiruna, Sweden. Univ Colorado, Atmospher & Space Phys Lab, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. RP Heldmann, JL (reprint author), NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. EM jheldmann@mail.arc.nasa.gov RI Mellon, Michael/C-3456-2016 NR 58 TC 60 Z9 60 U1 2 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 JUN PY 2007 VL 188 IS 2 BP 324 EP 344 DI 10.1016/j.icarus.2006.12.010 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 171AN UT WOS:000246707400005 ER PT J AU Smith, HT Johnson, RE Sittler, EC Shappirio, M Reisenfeld, D Tucker, OJ Burger, M Crary, FJ McComas, DJ Young, DT AF Smith, H. T. Johnson, R. E. Sittler, E. C. Shappirio, M. Reisenfeld, D. Tucker, O. J. Burger, M. Crary, F. J. McComas, D. J. Young, D. T. TI Enceladus: The likely dominant nitrogen source in Saturn's magnetosphere SO ICARUS LA English DT Article DE Saturn, magnetosphere; satellites; Enceladus; Titan ID CROSS-SECTIONS; PLASMA; IONS; SPECTROMETER; SATELLITE; DYNAMICS; PLUME; N2 AB The spatial distribution of N+ in Saturn's magnetosphere obtained from Cassini Plasma Spectrometer (CAPS) data can be used to determine the spatial distribution and relative importance of the nitrogen sources for Saturn's magnetosphere. We first summarize CAPS data from 15 orbits showing the spatial and energy distribution of the nitrogen component of the plasma. This analysis re-enforces our earlier discovery [Smith, HT., Shappirio, M., Sittler, E.C., Reisenfeld, D., Johnson, R.E., Baragiola, R.A., Crary, F.J., McComas, D.J., Young, D.T., 2005. Geophys. Res. Lett. 32 (14). L14S03] that Enceladus is likely the dominant nitrogen source for Saturn's inner magnetosphere. We also find a sharp enhancement in the nitrogen ion to water ion ratio near the orbit of Enceladus which, we show, is consistent with the presence of a narrow Enceladus torus as described in [Johnson, R.E., Liu, M., Sittler Jr., E.C., 2005. Geophys. Res. Lett. 32. L24201]. The CAPS data and the model described below indicate that N+ ions are a significant fraction of the plasma in this narrow torus. We then simulated the combined Enceladus and Titan nitrogen sources using the CAPS data as a constraint. This simulation is an extension of the model we employed earlier to describe the neutral tori produced by the loss of nitrogen from Titan [Smith, H.T., Johnson, R.E., Shematovich, V.I., 2004. Geophys. Res. Lett. 31 (16). L16804]. We show that Enceladus is the principal nitrogen source in the inner magnetosphere but Titan might account for a fraction of the observed nitrogen ions at the largest distances discussed. We also show that the CAPS data is consistent with Enceladus being a molecular nitrogen source with a nitrogen to water ratio roughly consistent with INMS [Waite, J.H., and 13 colleagues, 2006. Science 311 (5766), 1419-1422], but out-gassing of other nitrogen-containing species, such as ammonia, cannot be ruled out. (c) 2007 Elsevier Inc. All rights reserved. C1 SW Res Inst, Div Space Sci & Engn, San Antonio, TX 78227 USA. Univ Virginia, Charlottesville, VA 22904 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Montana, Dept Phys & Astron, Missoula, MT 59812 USA. RP Smith, HT (reprint author), SW Res Inst, Div Space Sci & Engn, 9503 W Commerce, San Antonio, TX 78227 USA. EM hts4f@virginia.edu RI Burger, Matthew/C-1310-2011; Reisenfeld, Daniel/F-7614-2015; Smith, Howard/H-4662-2016 OI Smith, Howard/0000-0003-3537-3360 NR 38 TC 32 Z9 32 U1 0 U2 5 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JUN PY 2007 VL 188 IS 2 BP 356 EP 366 DI 10.1016/j.icarus.2006.12.007 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 171AN UT WOS:000246707400007 ER PT J AU Wye, LC Zebker, HA Ostro, SJ West, RD Gim, YG Lorenz, RD AF Wye, Lauren C. Zebker, Howard A. Ostro, Steven J. West, Richard D. Gim, Yonggyu Lorenz, Ralph D. CA Cassini RADAR Team TI Electrical properties of Titan's surface from Cassini RADAR scatterometer measurements SO ICARUS LA English DT Article DE radar observations; satellites, surfaces; Saturn, satellites; Titan ID COHERENT-BACKSCATTER; DIELECTRIC-PROPERTIES; ICY SATELLITES; MOON; SCATTERING; RADIOMETER; VENUS AB We report regional-scale low-resolution backscatter images of Titan's surface acquired by the Cassini RADAR scatterometer at a wavelength of 2.18-cm. We find that the average angular dependence of the backscatter from large regions and from specific surface features is consistent with a model composed of a quasi-specular Hagfors term plus a diffuse cosine component. A Gaussian quasi-specular term also fits the data, but less well than the Hagfors term. We derive values for the mean dielectric constant and root-mean-square (rms) slope of the surface from the quasi-specular term, which we ascribe to scattering from the Surface interface only. The diffuse term accommodates contributions from volume scattering, multiple scattering, or wavelength-scale near-surface structure. The Hagfors model results imply a surface with regional mean dielectric constants between 1.9 and 3.6 and regional surface roughness that varies between 5.3 degrees and 13.4 degrees in rms-slope. Dielectric constants between 2 and 3 are expected for a surface composed of solid simple hydrocarbons, water ice, or a mixture of both. Smaller dielectric constants, between 1.6 and 1.9, are consistent with liquid hydrocarbons, while larger dielectric constants, near 4.5, may indicate the presence of water-ammonia ice [Lorenz, R.D., 1998. Icarus 136, 344-348] or organic heteropolymers [Thompson, W.R., Squyres, S.W., 1990. Icarus 86, 336-354]. We present backscatter images corrected for angular effects using the model residuals, which show strong features that correspond roughly to those in 0.94-mu m ISS images. We model the localized backscatter from specific features to estimate dielectric constant and rms slope when the angular coverage is within the quasi-specular part of the backscatter curve. Only two apparent surface features are scanned with angular coverage sufficient for accurate modeling. Data from the bright albedo feature Quivira Suggests a dielectric constant near 2.8 and rms slope near 10.1 degrees. The dark albedo feature Shangri-La is best fit by a Hagfors model with a dielectric constant close to 2.4 and an rms slope near 9.5 degrees. From the modeled backscatter curves, we find the average radar albedo in the same linear (SL) polarization to be near 0.34. We constrain the total-power albedo in order to compare the measurements with available groundbased radar results, which are typically obtained in both senses of circular polarization. We estimate an upper limit of 0.4 on the total-power albedo, a value that is significantly higher than the 0.21 total albedo value measured at 13 cm [Campbell, D., Black, G., Carter, L., Ostro, S., 2003. Science 302, 431-434]. This is consistent with a surface that has more small-scale structure and is thus more reflective at 2-cm than 13-cm. We compare results across overlapping observations and observe that the reduction and analysis are repeatable and consistent. We also confirm the strong correlations between radar and near-infrared images. (c) 2006 Elsevier Inc. All rights reserved. C1 Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Johns Hopkins Univ, Appl Phys Lab, Dept Space, Planetary Explorat Grp, Laurel, MD 20723 USA. RP Wye, LC (reprint author), Stanford Univ, Dept Elect Engn, Packard Bldg,350 Serra Mall, Stanford, CA 94305 USA. EM lcwye@stanford.edu RI Lorenz, Ralph/B-8759-2016 OI Lorenz, Ralph/0000-0001-8528-4644 NR 43 TC 34 Z9 34 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 JUN PY 2007 VL 188 IS 2 BP 367 EP 385 DI 10.1016/j.icarus.2006.12.008 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 171AN UT WOS:000246707400008 ER PT J AU Scheeres, DJ Abe, M Yoshikawa, M Nakamura, R Gaskell, RW Abell, PA AF Scheeres, D. J. Abe, M. Yoshikawa, M. Nakamura, R. Gaskell, R. W. Abell, P. A. TI The effect of YORP on Itokawa SO ICARUS LA English DT Article DE asteroids; rotational dynamics ID ASTEROID 25143-ITOKAWA; HAYABUSA; SHAPE AB The effect of solar radiation on the near-term rotation rate of Asteroid Itokawa via the YORP effect is predicted using the detailed shape model, rotation pole, mass estimate, and optical properties derived from the Hayabusa mission to Itokawa. Based on these estimates Itokawa is decelerating at a rate which will halve its rotation rate in only 50-90 thousand years, a large deceleration that should be detectable in a future appartion. The implications of such a large deceleration for Itokawa's past history are discussed and related to possible seismic shaking. (c) 2007 Elsevier Inc. All rights reserved. C1 Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058568, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lyndon B Johnson Space Ctr, Natl Aeronaut & Space Adm, Houston, TX 77058 USA. RP Scheeres, DJ (reprint author), Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. EM scheeres@umich.edu NR 19 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 JUN PY 2007 VL 188 IS 2 BP 425 EP 429 DI 10.1016/j.icarus.2006.12.014 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 171AN UT WOS:000246707400012 ER PT J AU Hicks, MD Bambery, RJ Lawrence, KJ Kollipara, P AF Hicks, Michael D. Bambery, Raymond J. Lawrence, Kenneth J. Kollipara, Priya TI Near-nucleus photometry of comets using archived NEAT data SO ICARUS LA English DT Article DE comets; photometry ID JUPITER-FAMILY COMETS; SPACE-TELESCOPE OBSERVATIONS; INNER COMA; MAGNITUDES AB Though optimized to discover and track fast moving Near-Earth Objects (NEOs), the Near-Earth Asteroid Tracking (NEAT) survey dataset can be mined to obtain information on the comet population observed serendipitously during the asteroid survey. We have completed analysis of over 400 CCD images of comets obtained during the autonomous operations of two 1.2-m telescopes: the first on the summit of Haleakala on the Hawaiian island of Maui and the second on Palomar Mountain in southern California. Photometric calibrations of each frame were derived using background catalog stars and the near-nucleus cornet photometry measured. We measured dust production and normalized magnitudes for the coma and nucleus in order to explore cometary activity and comet size-frequency distributions. Our data over an approximately two-year time frame (2001 August-2003 February) include 52 comets: 12 periodic, 19 numbered, and 21 non-periodic, obtained over a wide range of viewing geometries and helio/geocentric distances. Nuclear magnitudes were estimated for a subset of comets observed. We found that for low-activity comets (Af rho < 100 cm) our model gave reasonable estimates for nuclear size and magnitude. The slope of the cumulative luminosity function of our sample of low-activity comets was 0.33 +/- 0.04, consistent with the slope we measured for the Jupiter-farnily cometary nuclei collected by Fernandez et al. [Fernandez, J.A., Tancredi, G., Rickman, H., Licandro, J., 1999. Astron. Astrophys. 392, 327-340] of 0.38 +/- 0.02. Our slopes of the cumulative size distribution alpha = 1.50 +/- 0.08 agree well with the slopes measured by Whitman et al. [Whitman, K., Morbidelli, A., Jedicke, R., 2006. Icarus 183, 101-114], Meech et al. [Meech, K.J., Hainaut, O.R., Marsden, B.G., 2004. Icarus 170, 463-491], Lowry et al. [Lowry, S.C., Fitzsimmons, A., Collander-Brown, S., 2003. Astron. Astrophys. 397, 329-343], and Weissman and Lowry [Weissman, P.R., Lowry, S.C., 2003. Lunar Planet. Sci. 34. Abstract 34]. (c) 2007 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. RP Hicks, MD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,JPL MS 183-501, Pasadena, CA 91109 USA. EM hicksm@scn.jpl.nasa.gov NR 23 TC 6 Z9 7 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JUN PY 2007 VL 188 IS 2 BP 457 EP 467 DI 10.1016/j.icarus.2006.12.023 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 171AN UT WOS:000246707400015 ER PT J AU Dobrovolskis, AR Alvarellos, JL Lissauer, JJ AF Dobrovolskis, Anthony R. Alvarellos, Jose L. Lissauer, Jack J. TI Lifetimes of small bodies in planetocentric (or heliocentric) orbits SO ICARUS LA English DT Article DE celestial mechanics ID INNER SOLAR-SYSTEM; SHORT-PERIOD COMETS; IMPACT EJECTA; DYNAMICAL LIFETIMES; EVOLUTION; RELAXATION; OBJECTS; FATES; POPULATIONS; DELIVERY AB Stray bodies orbiting a planet or the Sun are removed by collisions with larger objects or by expulsion from the system. However, their rate of removal generally cannot be described by the simple exponential law used to describe radioactive decay, because their effective half-life lengthens with time. Previous studies of planetesimals, comets, asteroids, meteorites, and impact ejecta from planets or satellites have fit the number of survivors S vs elapsed time t using exponential, logarithmic, and power laws, but no entirely satisfactory functional form has been found yet. Herein we model the removal rates of impact ejecta from various moons Of Jupiter, Saturn, and Neptune. We find that most situations are fit best by stretched exponential decay, of the form S(t) = S(0) exp(-[t/t(0)](beta)). Here t(0) is the time when the initial population has declined by a factor of e approximate to 2.72, while the dimensionless exponent beta lies between 0 and 1 (often near 1/3). The e-folding time S[dS/dt](-1) itself grows as the [1 - beta] power of t. This behavior is suggestive of a diffusion-like process. (c) 2007 Elsevier Inc. All rights reserved. C1 Univ Calif Santa Cruz, NASA, Ames Res Ctr, Lick Observ, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Moffett Field, CA 94035 USA. RP Dobrovolskis, AR (reprint author), Univ Calif Santa Cruz, NASA, Ames Res Ctr, Lick Observ, 245-3, Moffett Field, CA 94035 USA. EM dobro@cosmic.arc.nasa.gov NR 51 TC 12 Z9 12 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 JUN PY 2007 VL 188 IS 2 BP 481 EP 505 DI 10.1016/j.icarus.2006.11.024 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 171AN UT WOS:000246707400017 ER PT J AU Curtis, S Brandt, M Bowers, G Brown, G Cheung, C Cooperider, C Desch, M Desch, N Dorband, J Gregory, K Lee, K Lunsford, A Minetto, F Truszkowski, W Wesenberg, R Vranish, J Abrahantes, M Clark, P Capon, T Weaker, M Watson, R Olivier, P Rilee, ML AF Curtis, Steven Brandt, Matthew Bowers, Greg Brown, Gary Cheung, Cynthia Cooperider, Caner Desch, Mike Desch, Noah Dorband, John Gregory, Kyle Lee, Ken Lunsford, Allan Minetto, Fred Truszkowski, Walt Wesenberg, Richard Vranish, John Abrahantes, Miguel Clark, Pamela Capon, Tom Weaker, Michael Watson, Richard Olivier, Philip Rilee, Michael L. TI Tetrahedral robotics for space exploration SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB A reconfigurable space filling robotic architecture has a wide range of possible applications. One of the more intriguing possibilities is mobility in very irregular and otherwise impassable terrain. NASA Goddard Space Flight Center is developing the third generation of its Addressable Reconfigurable Technology (ART) Tetrahedral Robotics Architecture. An ART-based variable geometry truss consisting of 12 tetrahedral elements made from 26 smart struts on a wireless network has been developed. The primary goal of this development is the demonstration of a new kind of robotic mobility that can provide access and articulation that complement existing capabilities. An initial set of gaits and other behaviors are being tested, and accommodations for payloads such as sensor and telemetry packages are being studied. Herein, we describe our experience with the ART Tetrahedral Robotics Architecture and the improvements implemented in the third generation of this technology. Applications of these robots to space exploration and the tradeoffs involved with this architecture will be discussed. C1 NASA, Goddard Space Flight Ctr, Lab Planetary Magnetospheres, Greenbelt, MD 20771 USA. Hope Coll, Dept Engn, Holland, MI 49423 USA. Catholic Univ Amer, Washington, DC 20064 USA. Mercer Univ, Sch Engn, Macon, GA 31207 USA. NASA, Goddard Space Flight Ctr, Comp Sci Corp, Natl Ctr Computat Sci, Greenbelt, MD 20771 USA. RP Curtis, S (reprint author), NASA, Goddard Space Flight Ctr, Lab Planetary Magnetospheres, Code 695, Greenbelt, MD 20771 USA. NR 9 TC 6 Z9 11 U1 2 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD JUN PY 2007 VL 22 IS 6 BP 22 EP 30 DI 10.1109/MAES.2007.384077 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 187FF UT WOS:000247832300004 ER PT J AU Ryan, RE AF Ryan, Robert E. TI Flight operations in the new millennium SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB New approaches are being studied for real-time interaction, and related supporting processes, with spacecraft and instruments in deep space. Spacecraft are evolving, improving in many ways, and generally becoming more robust. Operations is changing also, and will be more automated in the future. However, there is a challenge. Deep space missions are not all alike. The Operations phases of discovery and exploration are an extension of the research that creates the mission; they are the time of obtaining results. This examines the historical role of flight operations and its evolving processes to develop an understanding of the operational methods that will be effective in the future. It takes people, equipment, software, space, and connectivity for Operations success. A balance has to be struck between improving technology, gaining knowledge, automation, and realistic expectations. Finally, the recommended methods to gain efficiency in Operations are system-wide services and shared resources. These common processes will meet the challenge of varied missions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ryan, RE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 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 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD JUN PY 2007 VL 22 IS 6 BP 31 EP 35 DI 10.1109/MAES.2007.384078 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 187FF UT WOS:000247832300005 ER PT J AU Mei, XB Yoshida, W Deal, WR Liu, PH Lee, J Uyeda, J Dang, L Wang, J Liu, W Li, D Barsky, M Kim, YM Lange, M Chin, TP Radisic, V Gaier, T Fung, A Samoska, L Lai, R AF Mei, X. B. Yoshida, W. Deal, W. R. Liu, P. H. Lee, J. Uyeda, J. Dang, L. Wang, J. Liu, W. Li, D. Barsky, M. Kim, Y. M. Lange, M. Chin, T. P. Radisic, V. Gaier, T. Fung, A. Samoska, L. Lai, R. TI 35-nm InPHEMT SMMIC amplifier with 4.4-dB gain at 308 GHz SO IEEE ELECTRON DEVICE LETTERS LA English DT Article DE high-electron mobility transistor (HEMT); high frequency; indium phosphide (InP); submillimeter-wave monolithic microwave integrated circuit (SMMIC) amplifier ID HEMTS AB We report the first submillimeter-wave monolithic microwave integrated circuit (MMIC) amplifier with 4.4-dB measured gain at 308-GHz frequency, making it the highest frequency MMIC amplifier reported to date. In this letter, a 35-nm InP high.-electron mobility transistor process has been successfully developed with a projected maximum available gain of greater than, 7 dB at 300 GHz. The excellent de and RF performance makes it suitable for applications at frequencies well into the millimeter-wave band and, for the first time, in the submillimeter-wave band as well. C1 Northrop Grumman Corp, Redondo Beach, CA 90278 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mei, XB (reprint author), Northrop Grumman Corp, Redondo Beach, CA 90278 USA. EM gerry.mei@ngc.com NR 8 TC 29 Z9 30 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD JUN PY 2007 VL 28 IS 6 BP 470 EP 472 DI 10.1109/LED.2007.896897 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 172RP UT WOS:000246822000001 ER PT J AU Shaw, MD Schneiderman, JF Palmer, B Delsing, P Echternach, PM AF Shaw, M. D. Schneiderman, J. F. Palmer, B. Delsing, P. Echternach, P. M. TI Experimental realization of a differential charge qubit SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT Applied Superconductivity Conference CY AUG 27-SEP 01, 2006 CL Seattle, WA SP Amer Superconductor Corp, Univ Wisconsin-Madison, Appl Superconduct Ctr, Florida State Univ, Field Lab, Appl Superconduct Conf Inc, AYI WAH CHANG, Boeing Co, CCAS, Coalit Commercial Applicat Superconductors, Cryogen Ltd, Univ Cambridge, Dept Mat Sci & Metallurgy, Device Mat Grp, GE Global Res Ctr, Electromagnet & Superconduct Lab, IEEE Coucil Superconduct, Univ Cambridge, IRC Superconduct, Oxford Instruments, Superconductor Sci & Technol, Inst Phys Publ, SuperPower Inc, Univ Houston, TcSUH DE Josephson junction; quantum computation; quasiparticle; qubit; single-electron devices; superconducting devices ID SINGLE-ELECTRON-TRANSISTOR; QUANTUM-STATE; JUNCTIONS; DEVICES; NOISE AB We demonstrate the operation of a differential single Cooper-pair box, a charge qubit consisting of two aluminum islands, isolated from ground, coupled by a pair of small-area Josephson junctions. We have tested four devices, all of which show evidence of quasiparticle poisoning. The devices are characterized with microwave spectroscopy and temperature dependence studies. C1 Univ So Calif, Dept Phys & Astron, Los Angeles, CA 90089 USA. Lab Phys Sci, College Pk, MD 20740 USA. Chalmers, MC2, S-41296 Gothenburg, Sweden. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shaw, MD (reprint author), Univ So Calif, Dept Phys & Astron, Los Angeles, CA 90089 USA. EM shawm@usc.edu; jfschnei@usc.edu; bpalmer@lps.umd.edu; per.delsing@mc2.chalmers.se; pierre.m.echternach@jpl.nasa.gov RI Delsing, Per/F-7288-2010; Schneiderman, Justin/D-4508-2013 OI Delsing, Per/0000-0002-1222-3506; Schneiderman, Justin/0000-0002-4441-2360 NR 31 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 2007 VL 17 IS 2 BP 109 EP 112 DI 10.1109/TASC.2007.898653 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 195WE UT WOS:000248442200008 ER PT J AU Kaul, AB Kleinsasser, AW Bumble, B Leduc, HG Lee, KA AF Kaul, Anupama B. Kleinsasser, Alan W. Bumble, Bruce LeDuc, Henry G. Lee, Karen A. TI Ion beam nitridation of Al for tunnel barrier applications SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT Applied Superconductivity Conference CY AUG 27-SEP 01, 2006 CL Seattle, WA SP Amer Superconductor Corp, Univ Wisconsin-Madison, Appl Superconduct Ctr, Florida State Univ, Field Lab, Appl Superconduct Conf Inc, AYI WAH CHANG, Boeing Co, CCAS, Coalit Commercial Applicat Superconductors, Cryogen Ltd, Univ Cambridge, Dept Mat Sci & Metallurgy, Device Mat Grp, GE Global Res Ctr, Electromagnet & Superconduct Lab, IEEE Coucil Superconduct, Univ Cambridge, IRC Superconduct, Oxford Instruments, Superconductor Sci & Technol, Inst Phys Publ, SuperPower Inc, Univ Houston, TcSUH DE ion beam nitridation; Josephson junctions; low energy ion beams; tunnel barriers ID JUNCTIONS; ENERGY; FABRICATION; SURFACES; SILICON AB We have formed AlNx tunnel barriers in NbJosephson junctions using a nitrogen ion beam operated at low energy (< 150 eV). Independent control of ion energy and dose allowed for the exploration of a wide parameter space in which devices were fabricated with good quality and reproducibility with J(c) < 10 kA /cm(2). The junctions were stable up to temperatures of at least 200 degrees C, implying that the nitrogen atoms are strongly bound and do not desorb as gaseous molecular N-2. Large-area uniformity was also investigated where the spatial variation in ion. current density was correlated with J(c). This technique could be applied to form other metal nitrides at room temperature for device applications where a high degree of control is desired. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kaul, AB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM anu.kaul@jpl.nasa.gov NR 14 TC 1 Z9 1 U1 0 U2 1 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 2007 VL 17 IS 2 BP 198 EP 201 DI 10.1109/TASC.2007.898654 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 195WE UT WOS:000248442200029 ER PT J AU Prober, DE Teufel, JD Wilson, CM Frunzio, L Shen, M Schoelkopf, RJ Stevenson, TR Wollack, EJ AF Prober, D. E. Teufel, J. D. Wilson, C. M. Frunzio, L. Shen, M. Schoelkopf, R. J. Stevenson, T. R. Wollack, E. J. TI Ultrasensitive quantum-limited far-infrared STJ detectors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT Applied Superconductivity Conference 2006 CY AUG 27-SEP 01, 2006 CL Seattle, WA SP Amer Superconductor Corp, Univ Wisconsin-Madison, Appl Superconduct Ctr, Florida State Univ, Field Lab, Appl Superconduct Conf Inc, AYI WAH CHANG, Boeing Co, CCAS, Coalit Commercial Applicat Superconductors, Cryogen Ltd, Univ Cambridge, Dept Mat Sci & Metallurgy, Device Mat Grp, GE Global Res Ctr, Electromagnet & Superconduct Lab, IEEE Coucil Superconduct, Univ Cambridge, IRC Superconduct, Oxford Instruments, Superconductor Sci & Technol, Inst Phys Publ, SuperPower Inc, Univ Houston, TcSUH DE bolometers; submillimeter wave detectors; superconducting devices ID PHOTON COUNTER; ELECTRON AB We describe recent work at Yale on Superconducting Tunnel Junction (STJ) direct detectors that have been developed for submillimeter astronomy. To monitor the response of the detector with large readout bandwidth and excellent sensitivity, we use a novel readout based on radio frequency (RF) rellectometry, like the readout invented for the RF-SET. For calibration of the detector, we have developed an in-situ, on-chip, hot-cold photon source. This is a voltage biased gold microbridge. Noise emitted by the microbridge couples via a coplanar stripline to the detector. This provides a calibrated blackbody photon source with near unity coupling, fast chopping, and calculable output. We present recent detection results in the range 100-160 GHz. These demonstrate the expected good responsivity, high sensitivity, and fast response. This approach is easily used with a frequency-multiplexed readout, allowing economy of cold electronics. Ultimate sensitivity is in the range 1 x 10(-19) W/(Hz)(1/2). C1 Yale Univ, Dept Appl Phys, New Haven, CT 06511 USA. Yale Univ, Dept Phys, New Haven, CT 06511 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Prober, DE (reprint author), Yale Univ, Dept Appl Phys, New Haven, CT 06511 USA. EM daniel.prober@yale.edu; john.teufel@yale.edu; chris.wilson@mc2.chalmers.se; luigi.frunzio@yale.edu; minghao.shen@yale.edu; robert.schoelkopf@yale.edu; thomas.r.stevenson@nasa.gov; edwardj.wollack@nasa.gov RI Teufel, John/A-8898-2010; Schoelkopf, Robert/J-8178-2012; Wollack, Edward/D-4467-2012; OI Teufel, John/0000-0002-1873-9941; Wollack, Edward/0000-0002-7567-4451; Frunzio, Luigi/0000-0002-0272-5481 NR 20 TC 8 Z9 8 U1 0 U2 1 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 2007 VL 17 IS 2 BP 241 EP 245 DI 10.1109/TASC.2007.897397 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 195WE UT WOS:000248442200040 ER PT J AU Bell, M Antipov, A Karasik, B Sergeev, A Mitin, V Verevkin, A AF Bell, M. Antipov, A. Karasik, B. Sergeev, A. Mitin, V. Verevkin, A. TI Photon number-resolved detection with sequentially connected nanowires SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT Applied Superconductivity Conference 2006 CY AUG 27-SEP 01, 2006 CL Seattle, WA SP Amer Superconductor Corp, Univ Wiscosin-Madison, Appl Superconduct Ctr, Florida State Univ, Field Lab, Appl Superconduct Conf Inc, AYI WAH ChANG, Boeing Co, CCAS, Coalit Commercial Applicat Superconductors, Cryogen Ltd, Univ Cambridge, Dept Mat Sci & Metallurgy, Device Mat Grp, GE Global Res Ctr, Electromagnet & Superconduct Lab, IEEE Coucil Superconduct, Univ Cambridge, IRC Superconduct, Oxford Instruments, Superconductor Sci & Technol, Inst Phys Publ, SuperPower Inc, Univ Houston, TcSUH DE impedance; photon number resolving; sequentially connected nanowires; single photon detector; superconducting AB Sequentially connected superconducting nanowires, such as nanopatterned meanders, are very promising candidates for single-photon detectors capable to resolve a number of photons in the pulse. In such devices, the Photon Number-Resolved (PNR) mode is possible due to independent detection of electromagnetic quanta by different regions of the meander. Every photon creates a resistive region in the superconductive meander and the total resistance is expected to be proportional to the number of photons absorbed. While the PNR mode can be realized with available single-photon detectors based on NbN nanowires, up to now it has not been observed experimentally. Here we show that the PNR mode in NbN requires the proper impedance matching between readout circuitry and nanowire-based detector. We discuss possible design of the readout circuitry for PNR detection. Results of modeling show that a high impedance amplifier placed in close proximity to the superconducting nanostructure can provide effective readout for the NbN nanowire-based detector operating in PNR mode. C1 SUNY Buffalo, Dept Elect Engn, Buffalo, NY 14260 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Antipov, A (reprint author), SUNY Buffalo, Dept Elect Engn, Buffalo, NY 14260 USA. EM aantipov@buffalo.edu RI Karasik, Boris/C-5918-2011 NR 16 TC 8 Z9 9 U1 2 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 2007 VL 17 IS 2 BP 289 EP 292 DI 10.1109/TASC.2007.898616 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 195WE UT WOS:000248442200050 ER PT J AU Karasik, BS Olaya, D Wei, J Pereverzev, S Gershenson, ME Kawamura, JH McGrath, WR Sergeev, AV AF Karasik, Boris S. Olaya, David Wei, Jian Pereverzev, Sergey Gershenson, Michael E. Kawamura, Jonathan H. McGrath, William R. Sergeev, Andrei V. TI Record-low NEP in hot-electron titanium nanobolometers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT Applied Superconductivity Conference 2006 CY AUG 27-SEP 01, 2006 CL Seattle, WA SP Amer Superconductor Corp, Univ Wiscosin-Madison, Appl Superconduct Ctr, Florida State Univ, Field Lab, Appl Superconduct Conf Inc, AYI WAH ChANG, Boeing Co, CCAS, Coalit Commercial Applicat Superconductors, Cryogen Ltd, Univ Cambridge, Dept Mat Sci & Metallurgy, Device Mat Grp, GE Global Res Ctr, Electromagnet & Superconduct Lab, IEEE Coucil Superconduct, Univ Cambridge, IRC Superconduct, Oxford Instruments, Superconductor Sci & Technol, Inst Phys Publ, SuperPower Inc, Univ Houston, TcSUH DE bolometers; radiation detectors; submillimeter; wave detectors; superconducting devices ID SINGLE-PHOTON DETECTOR; ELECTROTHERMAL FEEDBACK; RANGE; ASTRONOMY; SENSORS; QUANTUM; COUNTER; SAFIR; FILMS AB We are developing hot-electron superconducting transition-edge sensors (TES) capable of counting THz photons and operating at T = 0.3 K. We fabricated superconducting Ti nanosensors with Nb contacts with a volume of similar to 3 x 10(-3) mu m(3) on planar Si substrates and have measured the thermal conductance in the material, G = 4 x 10(-14) W/K at 0.3 K, caused predominantly by the weak electron-phonon coupling. The corresponding phonon-noise NEP = 3 x 10(-19) W/Hz(1/2). De tection of single optical photons (1550 nm and 670 nm wavelength) has been demonstrated for larger devices and yielded the thermal time constants of 30 mu s at 145 mK and of 25 mu s at 190 mK. This Hot-Electron Direct Detector (HEDD) is expected to have a small enough energy fluctuation noise for detecting individual photons with nu > 1THz where NEP similar to 3 x 10(-20) W/Hz(1/2) is needed for spectroscopy in space. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Rutgers State Univ, Piscataway, NJ 08854 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 RI Wei, Jian/B-2137-2014; Karasik, Boris/C-5918-2011 OI Wei, Jian/0000-0002-8831-6418; NR 25 TC 25 Z9 28 U1 1 U2 8 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 2007 VL 17 IS 2 BP 293 EP 297 DI 10.1109/TASC.2007.897167 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 195WE UT WOS:000248442200051 ER PT J AU Stern, JA Farr, WH AF Stern, Jeffrey A. Farr, William H. TI Fabrication and characterization of superconducting NbN nanowire single photon detectors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT Applied Superconductivity Conference 2006 CY AUG 27-SEP 01, 2006 CL Seattle, WA SP Amer Superconductor Corp, Univ Wiscosin-Madison, Appl Superconduct Ctr, Florida State Univ, Field Lab, Appl Superconduct Conf Inc, AYI WAH ChANG, Boeing Co, CCAS, Coalit Commercial Applicat Superconductors, Cryogen Ltd, Univ Cambridge, Dept Mat Sci & Metallurgy, Device Mat Grp, GE Global Res Ctr, Electromagnet & Superconduct Lab, IEEE Coucil Superconduct, Univ Cambridge, IRC Superconduct, Oxford Instruments, Superconductor Sci & Technol, Inst Phys Publ, SuperPower Inc, Univ Houston, TcSUH DE NbN; single photon detector; SNSPD AB We report on the fabrication and characterization of high-speed, single photon detectors using superconducting NbN nanowires at a wavelength of 1064 nm. A 15 by 15 microns detector with a detector efficiency of 40% has been measured. Due to kinetic inductance, the recovery time of such large area detectors is longer than that of smaller or single wire detectors. The recovery time of our detectors (50 ns) has been characterized by measuring the inter-arrival time statistics of our detector. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Stern, JA (reprint author), Jet Prop Lab, MS 302-231, Pasadena, CA 91109 USA. EM stern@jpl.nasa.gov; william.h.farr@jpl.nasa.gov NR 7 TC 17 Z9 17 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 2007 VL 17 IS 2 BP 306 EP 309 DI 10.1109/TASC.2007.898060 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 195WE UT WOS:000248442200054 ER PT J AU Karpov, A Miller, D Rice, F Stern, JA Bumble, B LeDuc, HG Zmuidzinas, J AF Karpov, A. Miller, D. Rice, F. Stern, J. A. Bumble, B. LeDuc, H. G. Zmuidzinas, J. TI Low noise 1 THz-1.4 THz mixers using Nb/Al-A1N/NbTiN SIS junctions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT Applied Superconductivity Conference 2006 CY AUG 27-SEP 01, 2006 CL Seattle, WA SP Amer Superconductor Corp, Univ Wiscosin-Madison, Appl Superconduct Ctr, Florida State Univ, Field Lab, Appl Superconduct Conf Inc, AYI WAH ChANG, Boeing Co, CCAS, Coalit Commercial Applicat Superconductors, Cryogen Ltd, Univ Cambridge, Dept Mat Sci & Metallurgy, Device Mat Grp, GE Global Res Ctr, Electromagnet & Superconduct Lab, IEEE Coucil Superconduct, Univ Cambridge, IRC Superconduct, Oxford Instruments, Superconductor Sci & Technol, Inst Phys Publ, SuperPower Inc, Univ Houston, TcSUH DE niobium alloys; radio astronomy; satellite applications; submillimeter wave receivers; superconductor-insulator-superconductor mixers; THz technology ID ASTRONOMY; SOFIA AB We present the development of a low noise 1.2 THz and 1.4 THz SIS mixers for heterodyne spectrometry on the Stratospheric Observatory For Infrared Astronomy (SOFIA) and Herschel Space Observatory. This frequency range is above the limit for the commonly used Nb quasi particle SIS junctions, and a special type of hybrid Nb/AIN/NbTiN junctions has been developed for this project. We are using a quasi-optical mixer design with two Nb/AIN/NbTiN junctions with an area of 0.25 mu m(2). The SIS junction tuning circuit is made of Nb and gold wire layers. At 1.13 THz the minimum SIS receiver uncorrected noise temperature is 450 K. The SIS receiver noise corrected for the loss in the LO coupler and in the cryostat optics is 350-450 K across 1.1-1.25 THz band. The receiver has a uniform sensitivity in a full 4-8 GHz IF band. The 1.4 THz SIS receiver test at 1.33-1.35 THz gives promising results, although limited by the level of available LO power. Extrapolation of the data obtained with low LO power level shows a possibility to reach 500 K DSB receiver noise using already existing SIS mixer. C1 CALTECH, Dept Phys, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Karpov, A (reprint author), CALTECH, Dept Phys, Pasadena, CA 91125 USA. EM karpov@submm.caleh.edu NR 9 TC 24 Z9 24 U1 0 U2 6 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 2007 VL 17 IS 2 BP 343 EP 346 DI 10.1109/TASC.2007.898277 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 195WE UT WOS:000248442200063 ER PT J AU Tong, CYE Blundell, R Megerian, KG Stern, JA Pospieszalski, M Pan, SK AF Tong, Cheuk-Yu Edward Blundell, Raymond Megerian, Krikor G. Stern, Jeffrey A. Pospieszalski, Marian Pan, Shing-Kuo TI Gain enhancement in inductively-loaded distributed SIS junction Arrays SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT Applied Superconductivity Conference 2006 CY AUG 27-SEP 01, 2006 CL Seattle, WA SP Amer Superconductor Corp, Univ Wiscosin-Madison, Appl Superconduct Ctr, Florida State Univ, Field Lab, Appl Superconduct Conf Inc, AYI WAH ChANG, Boeing Co, CCAS, Coalit Commercial Applicat Superconductors, Cryogen Ltd, Univ Cambridge, Dept Mat Sci & Metallurgy, Device Mat Grp, GE Global Res Ctr, Electromagnet & Superconduct Lab, IEEE Coucil Superconduct, Univ Cambridge, IRC Superconduct, Oxford Instruments, Superconductor Sci & Technol, Inst Phys Publ, SuperPower Inc, Univ Houston, TcSUH DE intermediate frequency bandwidth; mixer theory; submillimeter waves; superconductor-insulator-superconductor mixers ID BANDWIDTH; RECEIVER AB Due to their very low IF output capacitance, series-connected distributed SIS junction array mixers possess very wide IF bandwidth. However, careful control of parasitic inductance in the IF network is important in order to obtain a flat IF response in this class of wideband mixer. We have studied the effect of inductive loading on the operation of these mixers, both experimentally and theoretically. It is shown that over the range of IF where the reactive part of the load impedance is large, a higher mixer conversion gain accompanied by a lower noise temperature is observed. 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; mpospies@nrao.edu; span2@nrao.edu OI Tong, Edward/0000-0002-7736-4203 NR 8 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 2007 VL 17 IS 2 BP 371 EP 374 DI 10.1109/TASC.2007.898180 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 195WE UT WOS:000248442200070 ER PT J AU Nguyen-Vu, TDB Chen, H Cassell, AM Andrews, RJ Meyyappan, M Li, J AF Nguyen-Vu, T. D. Barbara Chen, Hua Cassell, Alan M. Andrews, Russell J. Meyyappan, M. Li, Jun TI Vertically aligned carbon nanofiber architecture as a multifunctional 3-D neural electrical interface SO IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING LA English DT Article DE neural electrical interface; neural stimulation; neuromodulation; vertically aligned carbon nanofibers ID CONDUCTING-POLYMER; MAMMALIAN-CELLS; PC12 CELLS; NANOTUBE; STIMULATION; STIFFNESS; ADHESION; RELEASE; GROWTH; FILMS AB Developing biomaterial constructs that closely mimic the natural tissue microenvironment with its complex chemical and physical cues is essential for improving the function and reliability of implantable devices, especially those that require direct neural-electrical interfaces. Here we demonstrate that free-standing vertically aligned carbon nanofiber (VACNF) arrays can be used as a multifunctional 3-D brush-like nanoengineered matrix that interpenetrates the neuronal network of PC12 cells. We found that PC12 neuron cells cultured on VACNF substrates can form extended neural network upon proper chemical and biochemical modifications. The soft 3-D VACNF architecture provides a new platform to fine-tune the topographical, mechanical, chemical, and electrical cues at subcellular nanoscale. This new biomaterial platform can be used for both fundamental studies of material-cell interactions and the development of chronically stable implantable neural devices. Micropatterned multiplex VACNF arrays can be selectively controlled by electrical and electrochemical methods to provide localized stimulation with extraordinary spatiotemporal resolution. Further development of this technology may potentially result in a highly multiplex closed-loop system with multifunctions for neuromodulation and neuroprostheses. C1 NASA, Ames Res Ctr, Univ Affiliated Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. NASA, Ames Res Ctr, ELORET, Moffett Field, CA 94035 USA. RP Li, J (reprint author), NASA, Ames Res Ctr, Univ Affiliated Res Ctr, MS 229-1, Moffett Field, CA 94035 USA. EM bnguyenv@stanford.edu; hchen@mail.arc.nasa.gov; acassell@mail.arc.nasa.gov; rja@russelljandrews.org; mmeyyappan@mail.arc.nasa.gov; jh@mail.arc.nasa.gov RI Li, Jun/H-7771-2013; OI Li, Jun/0000-0002-3689-8946; Nguyen-Vu, T.D. Barbara/0000-0002-4708-1982 FU NINDS NIH HHS [R21 NS047721, 5 R21 NS047721] NR 39 TC 85 Z9 87 U1 8 U2 23 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9294 J9 IEEE T BIO-MED ENG JI IEEE Trans. Biomed. Eng. PD JUN PY 2007 VL 54 IS 6 BP 1121 EP 1128 DI 10.1109/TBME.2007.891169 PN 1 PG 8 WC Engineering, Biomedical SC Engineering GA 172RK UT WOS:000246821500017 PM 17554831 ER PT J AU Suarez, G Jimenez, M Fernandez, FO AF Suarez, George Jimenez, Manuel Fernandez, Felix O. TI Behavioral modeling methods for switched-capacitor Sigma Delta modulators SO IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS LA English DT Article DE behavioral modeling; switched-capacitor (SC) integrator; sigma-delta modulator (Sigma Delta Ms); Simulink SDM; SC integrator; VHDL-AMS SDM AB Sigma-delta Modulators (Sigma AMs) are cornerstone elements in oversampled analog-to-digital converters and digital-to-analog converters (DACs). Although transistor-level simulation is the most accurate approach known for these components, this method becomes impractical for complex systems due to its long computational time requirements. Behavioral modeling has become a viable solution to this problem. In this paper, we study styles and issues in the accurate modeling of low-power, high-speed Sigma AMs and introduce two new behavioral models for switched-capacitor (SC) integrators. The first model is based on the SC integrator transient response, including the effects of the amplifier transconductance, output conductance, and the dynamic capacitive loading effect on the settling time. The second model is based on a symbolic node admittance matrix representation of the system. Nonidealities such as jitter, thermal noise, and DAC mismatch are also addressed and included in a dual-band, GSM/WCDMA, second-order, multibit Sigma AM model with individual level averaging. VHDL-AMS and MATLAB Simulink were used as modeling languages.-Both models are validated against experimental data, showing competitive results in the signal-to-noise-plus-distortion ratio. A comparative analysis between the proposed and a traditional model is presented, with emphasis on the degrading effects due to the integrator dynamics. Moreover, a general simulation speed analysis of the proposed models is addressed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Puerto Rico, Dept Elect & Comp Engn, Mayaguez, PR 00681 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Suarez, G (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM george.suarez@nasa.gov; mjimenez@ece.uprm.edu; fofernandez@tamu.edu NR 20 TC 21 Z9 22 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1549-8328 J9 IEEE T CIRCUITS-I JI IEEE Trans. Circuits Syst. I-Regul. Pap. PD JUN PY 2007 VL 54 IS 6 BP 1236 EP 1244 DI 10.1109/TCSI.2007.897767 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 178YK UT WOS:000247256100007 ER PT J AU Chen, Y Federspiel, X Sullivan, T Tao, G Tonti, B Young, C Zafar, S AF Chen, Yuan Federspiel, Xavier Sullivan, Tim Tao, Guoqiao Tonti, Bill Young, Chadwin Zafar, Sub TI Introduction to the Special Issue on 2006 International Integrated Reliability Workshop (IIRW) SO IEEE TRANSACTIONS ON DEVICE AND MATERIALS RELIABILITY LA English DT Editorial Material C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Qimonda, D-01099 Dresden, Germany. IBM Microelect, Essex Jct, VT 05452 USA. SEMATECH, Austin, TX 78741 USA. IBM Microelect, Yorktown Hts, NY USA. RP Chen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Yuan.Chen@jpl.nasa.gov; xavier.federspiel@qimonda.com; tdsulliv@us.ibm.com; guoqiao.tao@nxp.com; wtonti@us.ibm.com; Chadwin.Young@SEMATECH.Org; szafar@us.ibm.com NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1530-4388 J9 IEEE T DEVICE MAT RE JI IEEE Trans. Device Mater. Reliab. PD JUN PY 2007 VL 7 IS 2 BP 215 EP 216 DI 10.1109/TDMR.2007.902085 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 209QW UT WOS:000249404100001 ER PT J AU Chen, KS Crawford, MM Gamba, P Smith, JS AF Chen, Kun-Shan Crawford, Melba M. Gamba, Paolo Smith, James S. TI Introduction for the special issue on remote sensing for major disaster prevention, monitoring, and assessment SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Editorial Material C1 Natl Cent Univ, Fac Ctr Space & Remote Sensing Res, Chungli 32054, Taiwan. Purdue Univ, Lab Applicat Remore Sensing, W Lafayette, IN 47907 USA. Univ Pavia, Dept Elect, I-127100 Pavia, Italy. NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA. RP Chen, KS (reprint author), Natl Cent Univ, Fac Ctr Space & Remote Sensing Res, Chungli 32054, Taiwan. RI Gamba, Paolo/G-1959-2010 OI Gamba, Paolo/0000-0002-9576-6337 NR 11 TC 3 Z9 3 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUN PY 2007 VL 45 IS 6 BP 1515 EP 1518 DI 10.1109/TGRS.2007.899144 PN 1 PG 4 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 174FB UT WOS:000246926100001 ER PT J AU Tralli, DM Blom, RG Fielding, EJ Donnellan, A Evans, DL AF Tralli, David M. Blom, Ronald G. Fielding, Eric J. Donnellan, Andrea Evans, Diane L. TI Conceptual case for assimilating interferometric synthetic aperture radar data into the HAZUS-MH earthquake module SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE HAZUS; interferometric synthetic aperture radar (InSAR); Observing System Simulation Experiment (OSSE); remote sensing; seismic hazard analysis ID LANDERS EARTHQUAKE; FIELD AB The study of the Earth as a system is being adopted widely by geoscientists. Numerical models and simulations are providing the capability to rapidly test hypotheses and make forecasts of complex geophysical behavior. International efforts are seeking to integrate existing and emerging Earth observation systems into a global network, with enhanced data distribution, models, and decision support tools. Remote sensing is poised to fulfill the increasing need for a synoptic framework. However, the desire to improve the connection between scientific research and societal benefits has not been matched with resources and tools required to bridge the gap between research and applications. Natural hazards research and disaster management are a prime example. Here, we present a conceptual case for how interferometric synthetic aperture radar (InSAR) data could make a definitive contribution to understanding earthquake processes while simultaneously supporting policy- and decision-making. InSAR measurements derived from time series of radar observations from Earth orbit uniquely can provide geographically comprehensive maps of surface deformation. Observing system simulations are suggested to evaluate the potential contributions of a future system. Simulations would adopt an open seismic hazard analysis (SHA) framework, OpenSHA, recognizing the need for more physics-based modeling and computational infrastructure. SHA is employed by the HAZUS-MH earthquake module to estimate losses. InSAR measurements of strain accumulation would provide event magnitude recurrence bounds for probabilistic SHA, while coseismic InSAR measurements would add constraints on fault rupture models for deterministic approaches. Moreover, interferograms would be incorporated graphically as proxy seismic risk maps for planning and mitigation. C1 CALTECH, Jet Prop Lab, Earth Sci & Technol Directorate, Pasadena, CA 91109 USA. RP Tralli, DM (reprint author), CALTECH, Jet Prop Lab, Earth Sci & Technol Directorate, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Fielding, Eric/A-1288-2007 OI Fielding, Eric/0000-0002-6648-8067 NR 21 TC 4 Z9 4 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUN PY 2007 VL 45 IS 6 BP 1595 EP 1604 DI 10.1109/TGRS.2007.895848 PN 1 PG 10 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 174FB UT WOS:000246926100008 ER PT J AU Pun, IF Lin, II Wu, CR Ko, DH Liu, WT AF Pun, Iam-Fei Lin, I-I Wu, Chau-Ron Ko, Dong-Han Liu, W. Timothy TI Validation and application of altimetry-derived upper ocean thermal structure in the western North Pacific Ocean for typhoon-intensity forecast SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE altimetry; typhoon; upper ocean thermal structure ID SEA-SURFACE TEMPERATURE; TROPICAL CYCLONES; HURRICANE INTENSITY; TRANSPORT; EDDY; HEAT; OPAL; ARGO AB This paper uses more than 5000 colocated and near-coincident in-situ profiles from the National Oceanic and Atmospheric Administration/Global Temperature and Salinity Profile Program database spanning over the period from 2002 to 2005 to systematically validate the satellite-altimetry-derived upper ocean thermal structure in the western North Pacific ocean as such ocean thermal structure information is critical in typhoon-intensity change. It is found that this satellite-derived information is applicable in the central and the southwestern North Pacific (covering 122-170 degrees E, 9-25 degrees N) but not in the northern part (130-170 degrees E, 25-40 degrees N). However, since > 80% of the typhoons are found to intensify in the central and southern part, this regional dependence should not pose a serious constraint in studying typhoon intensification. Further comparison with the U.S. Naval Research Laboratory's North Pacific Ocean Nowcast/Forecast System (NPACNFS) hydrodynamic ocean model shows similar regional applicability, but NPACNFS is found to have a general underestimation in the upper ocean thermal structure and causes a large underestimation of the tropical cyclone heat potential (TCHP) by up to 60 kJ/cm(2). After validation, the derived upper ocean thermal profiles are used to study the intensity change of supertyphoon Dianmu (2004). It is found that two upper ocean parameters, i.e., a typhoon's self-induced cooling and the during-typhoon TCHP, are the most sensitive parameters (with R-2 similar to 0. 7) to the 6-h intensity change of Dianmu during the study period covering Dianmu's rapid intensification to category 5 and its subsequent decay to category 4. This paper suggests the usefulness of satellite-based upper ocean thermal information in future research and operation that is related to typhoon-intensity change in the western North Pacific. C1 Natl Taiwan Univ, Dept Atmospher Sci, Taipei 106, Taiwan. Natl Taiwan Univ, Dept Earth Sci, Taipei 106, Taiwan. USN, Res Lab, Coastal & Semi Enclosed Sea Sect, Stennis Space Ctr, MS 39529 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Pun, IF (reprint author), Natl Taiwan Univ, Dept Atmospher Sci, Taipei 106, Taiwan. EM faye@webmail.as.ntu.edu.tw; iilin@webmail.as.ntu.edu.tw; ewu@cc.ntnu.edu.tw; ko@nrlssc.navy.mil; W.Timothy.Liu@jpl.nasa.gov RI Lin, I-I/J-4695-2013 OI Lin, I-I/0000-0002-8364-8106 NR 38 TC 35 Z9 35 U1 0 U2 11 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 2007 VL 45 IS 6 BP 1616 EP 1630 DI 10.1109/TGRS.2007.895950 PN 1 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 174FB UT WOS:000246926100010 ER PT J AU Hong, Y Adler, RF Huffman, G AF Hong, Yang Adler, Robert F. Huffman, George TI An experimental global prediction system for rainfall-triggered landslides using satellite remote sensing and geospatial datasets SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE landslide; landslide susceptibility (LS); natural disasters; real-time precipitation analysis; satellite remote sensing ID HAZARD ZONATION; LANTAU ISLAND; DEBRIS FLOWS; PUERTO-RICO; HONG-KONG; GIS; SUSCEPTIBILITY; PRECIPITATION; INTENSITY; MODELS AB Landslides triggered by rainfall can possibly be foreseen in real time by jointly using rainfall intensity-duration thresholds and information related to land surface susceptibility. However, no system exists at either a national or a global scale to monitor or detect rainfall conditions that may trigger landslides due to the lack of sufficient ground-based observing network in many parts of the world. Recent advances in satellite remote sensing technology and increasing availability of high-resolution geospatial products around the globe have provided an unprecedented opportunity for such a study. In this paper, a framework for developing an experimental real-time prediction system to identify where rainfall-triggered landslides will occur is proposed by combining two necessary components: surface landslide susceptibility (LS) and a real-time space-based rainfall analysis system. First, a global LS map is derived from a combination of semistatic global surface characteristics (digital elevation topography, slope, soil types, soil texture, land cover classification, etc.) using a geographic information system weighted linear combination approach. Second, an adjusted empirical relationship between rainfall intensity-duration and landslide occurrence is used to assess landslide hazards at areas with high susceptibility. A major outcome of this paper is the availability for the first time of a global assessment of landslide hazards, which is only possible because of the utilization of global satellite remote sensing products. This experimental system can be updated continuously using the new satellite remote sensing products. This proposed system, if pursued through wide interdisciplinary efforts as recommended herein, bears the promise to grow many local landslide hazard analyses into a global decision-making support system for landslide C1 Univ Maryland, Goddard Earth Sci Technol Ctr, Catonsville, MD 21228 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Hong, Y (reprint author), Univ Maryland, Goddard Earth Sci Technol Ctr, Catonsville, MD 21228 USA. EM yanghong@agnes.gsfc.nasa.gov RI Hong, Yang/D-5132-2009; Huffman, George/F-4494-2014 OI Hong, Yang/0000-0001-8720-242X; Huffman, George/0000-0003-3858-8308 NR 44 TC 39 Z9 41 U1 4 U2 32 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 2007 VL 45 IS 6 BP 1671 EP 1680 DI 10.1109/TGRS.2006.888436 PN 1 PG 10 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 174FB UT WOS:000246926100015 ER PT J AU Saatchi, S Halligan, K Despain, DG Crabtree, RL AF Saatchi, Sassan Halligan, Kerry Despain, Don G. Crabtree, Robert L. TI Estimation of forest fuel load from radar remote sensing SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE canopy bulk density; canopy fuel; forest biomass; polarimetric synthetic aperture radar (SAR); radar; wildfire; Yellowstone National Park (YNP) ID YELLOWSTONE-NATIONAL-PARK; WATER-CONTENT; BULK-DENSITY; LANDSAT TM; SAR DATA; FIRE; BIOMASS; GENERATION; MOISTURE; LIDAR AB Understanding fire behavior characteristics and planning for fire management require maps showing the distribution of wildfire fuel loads at medium to fine spatial resolution across large landscapes. Radar sensors from airborne or spaceborne platforms have the potential of providing quantitative information about the forest structure and biomass components that can be readily translated to meaningful fuel load estimates for fire management. In this paper, we used multifrequency polarimetric synthetic aperture radar (SAR) imagery acquired over a large area of the Yellowstone National Park by the Airborne SAR sensor to estimate the distribution of forest biomass and canopy fuel loads. Semiempirical algorithms were developed to estimate crown and stem biomass and three major fuel load parameters, namely: 1) canopy fuel weight; 2) canopy bulk density; and 3) foliage moisture content. These estimates, when compared directly to measurements made at plot and stand levels, provided more than 70% accuracy and, when partitioned into fuel load classes, provided more than 85% accuracy. Specifically, the radar-generated fuel parameters were in good agreement with the field-based fuel measurements, resulting in coefficients of determination of R-2 = 85 for the canopy fuel weight, R-2 = 0.84 for canopy bulk density, and R-2 = 0.78 for the foliage biomass. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 USA. Yellowstone Ecol Res Ctr, Bozeman, MT 59718 USA. US Geol Survey, Bozeman, MT 59717 USA. RP Saatchi, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM saatchi@congo.jpl.nasa.gov NR 51 TC 75 Z9 86 U1 3 U2 31 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 2007 VL 45 IS 6 BP 1726 EP 1740 DI 10.1109/TGRS.2006.887002 PN 1 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 174FB UT WOS:000246926100020 ER PT J AU Hook, SJ Vaughan, RG Tonooka, H Schladow, SG AF Hook, Simon J. Vaughan, R. Greg Tonooka, Hideyuki Schladow, S. Geoffrey TI Absolute radiometric in-flight validation of mid infrared and thermal infrared data from ASTER and MODIS on the terra spacecraft using the Lake Tahoe, CA/NV, USA, automated validation site SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE advanced spaceborne thermal emission and reflection radiometer (ASTER); infrared; moderate resolution imaging spectroradiometer (MODIS); Tahoe; thermal; validation ID TRACK SCANNING RADIOMETER; SURFACE TEMPERATURE; CALIBRATION; EMISSIVITY; CALIFORNIA; SYSTEM; EARTH AB In December 1999, the first Moderate Resolution Imaging Spectroradiometer (MODIS) instrument and an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument were launched into polar orbit on the Terra spacecraft. Both instruments measure surface radiance, which requires that they are calibrated and validated in flight. In-flight validation is essential to independently verify that instrument calibration correctly compensates for any changes in instrument response over time. In order to meet this requirement, an automated validation site was established at Lake Tahoe on the California/Nevada border in 1999 to validate the ASTER and MODIS thermal infrared (TIR, 7-13 mu m) and MODIS mid infrared (MIR, 3-n5 mu m) land-monitoring channels. Daytime and nighttime data were used to validate the TIR channels, and only nighttime data were used to validate the MIR channels to avoid any reflected solar contribution. Sixty-nine ASTER scenes and 155 MODIS-Terra scenes acquired between years 2000 and 2005 with near-nadir views were validated. The percent differences between the predicted and instrument at-sensor radiances for ASTER channels 10-14 were 0.165 +/- 0.776, 0.103 +/- 0.613, -0.305 +/- 0.613, -0.252 +/- 0.464, and -0.118 +/- 0.489, respectively. The percent differences for MODIS-Terra channels 20, 22, 23, 29, 31, and 32 were -1.375 +/- 0.973, -1.743 +/- 1.027, -0.898 +/- 0.970, 0.082 +/- 0.631, 0.044 +/- 0.541, and 0.151 +/- 0.563, respectively. The results indicate that the TIR at-sensor radiances from ASTER and MODIS-Terra have met the preflight radiometric calibration accuracy specification and provide well-catibrated data sets that are suitable for measuring absolute change. The results also show that the at-sensor radiances from the MODIS-Terra MIR channels have greater bias than expected based on the preflight radiometric calibration accuracy specification. C1 CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. Ibaraki Univ, Ctr Informat Technol, Ibaraki 3168511, Japan. Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA. Univ Calif Davis, Tahoe Environm Res Ctr, Davis, CA 95616 USA. RP Hook, SJ (reprint author), CALTECH, Jet Prop Lab, NASA, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 25 TC 76 Z9 76 U1 1 U2 17 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 2007 VL 45 IS 6 BP 1798 EP 1807 DI 10.1109/TGRS.2007.894564 PN 2 PG 10 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 174FC UT WOS:000246926200005 ER PT J AU Quweider, MK Scargle, JD Jackson, B AF Quweider, M. K. Scargle, J. D. Jackson, B. TI Grey level reduction for segmentation, thresholding and binarisation of images based on optimal partitioning on an interval SO IET IMAGE PROCESSING LA English DT Article ID ENTROPY; SELECTION; PERFORMANCE; HISTOGRAMS; COLOR AB Optimal reduction of the number of grey levels present in an image is a fundamental problem in segmentation, classification, lossy compression, quantisation, inspection and computer vision. We present a new algorithm based on dynamic programming and optimal partitioning of the image data space, or its histogram representation. The algorithm allows the reduction of the number of grey levels for an image in a fine to coarse fashion, starting with the original grey levels present in the image and all the way down to two grey levels that simply create a binarised version of the original image. The algorithm can also be used to find a reduced number of grey levels in a natural way without forcing a specific number ahead of time. Application of the algorithm is demonstrated in image segmentation, multi-level thresholding and binarisation, and is shown to give very good results compared to many of the existing methods. C1 Univ Texas, Dept CS CIS, Brownsville, TX 78520 USA. NASA, Ames Res Ctr, Dept Space, Div Sci, Moffett Field, CA 94035 USA. San Jose State Univ, Dept Math, San Jose, CA 95192 USA. RP Quweider, MK (reprint author), Univ Texas, Dept CS CIS, Brownsville, TX 78520 USA. EM mkquweider@utb.edu NR 29 TC 11 Z9 11 U1 0 U2 2 PU INST ENGINEERING TECHNOLOGY-IET PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 1751-9659 J9 IET IMAGE PROCESS JI IET Image Process. PD JUN PY 2007 VL 1 IS 2 BP 103 EP 111 DI 10.1049/iet-ipr:20050262 PG 9 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA 212FE UT WOS:000249578200001 ER PT J AU Andrews, RJ AF Andrews, Russell J. TI "Extreme CARS": nanotechniques for neurosurgery SO INTERNATIONAL JOURNAL OF COMPUTER ASSISTED RADIOLOGY AND SURGERY LA English DT Article DE Carbon nanotube; Nanoelectrode; Nanoscaffold; Nanotechnology; Neuromodulation; Quantum dot; Spinal cord injury AB Neurosurgery involves many diagnoses which are nervous system disorders at the cellular/neuronal level (e. g., brain tumors, epilepsy, movement disorders), but our techniques to date have been 'macro' (e. g., excision, ablation). We introduce nano-techniques which will in time make possible the 'sculpting' of nervous system disorders-neuron-by-neuron, if need be. These nanotechniques include nanoimaging (notably with quantum dots), nanoscaffolds for guiding nanorepair, carbon nanotube arrays for monitoring and modulating the neuronal level electrochemical environment, and micron-level cutting and splicing of damaged axons. Many of these nanotechniques have been combined in a multimodality device for understanding and enhancing axonal regeneration in spinal cord injury. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Andrews, RJ (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 1861-6410 EI 1861-6429 J9 INT J COMPUT ASS RAD JI Int. J. Comput. Assist. Radiol. Surg. PD JUN PY 2007 VL 2 SU 1 BP S442 EP S444 PG 3 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging; Surgery SC Engineering; Radiology, Nuclear Medicine & Medical Imaging; Surgery GA V32ZD UT WOS:000208988200229 ER PT J AU Kuczmarski, MA Gokoglu, SA AF Kuczmarski, Maria A. Gokoglu, Suleyman A. TI Buoyancy suppression in gases at high temperatures SO INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW LA English DT Article DE buoyancy; natural convection; numerical modeling; Benard problem ID BOUSSINESQ APPROXIMATION; DIFFUSION FLAMES; CONVECTION AB The computational fluid dynamics code FLUENT was used to study Rayleigh instability at large temperature differences in a sealed gas-filled enclosure with a cold top wall and a heated bottom wall (Benard problem). Both steady state and transient calculations were performed. Instability boundaries depending on the geometry, temperature, and pressure were defined that showed the system tended to become more unstable when the hot-wall temperature increased beyond a certain level, a result of the dampening effect of gas viscosity at higher temperatures. Results also showed that the eventual system stability depended on the final pressure reached at steady state, regardless of how fast the bottom-wall temperature was ramped up to minimize time spent in the unstable region of fluid motion. It was shown that the final system state can differ depending on whether results are obtained via a steady-state or transient calculation, demonstrating that the history of the flow structure development and corresponding temperature fields in this type of system has a profound effect on the final state. Finally, changes in the slope of the pressure-versus-time curve were found to be good indicators of flow pattern changes, and can be a convenient experimental tool for diagnosing the expected changes in flow behavior in such systems. (C) 2006 Elsevier Inc. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Kuczmarski, MA (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Maria.A.Kuczmarski@nasa.gov NR 21 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0142-727X J9 INT J HEAT FLUID FL JI Int. J. Heat Fluid Flow PD JUN PY 2007 VL 28 IS 3 BP 496 EP 511 DI 10.1016/j.ijheatfluidflow.2006.07.006 PG 16 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 172RU UT WOS:000246822500012 ER PT J AU Rothschild, L AF Rothschild, Lynn TI The living universe: NASA and the development of astrobiology. SO ISIS LA English DT Book Review C1 NASA, Ames Res Ctr, Astrobiol Strateg Anal & Support Off, Ames, IA USA. RP Rothschild, L (reprint author), NASA, Ames Res Ctr, Astrobiol Strateg Anal & Support Off, Ames, IA USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0021-1753 J9 ISIS JI Isis PD JUN PY 2007 VL 98 IS 2 BP 423 EP 424 DI 10.1086/521492 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 189IA UT WOS:000247981400066 ER PT J AU Donachie, SP Foster, JS Brown, MV AF Donachie, Stuart P. Foster, Jamie S. Brown, Mark V. TI Culture clash: challenging the dogma of microbial diversity - Commentaries SO ISME JOURNAL LA English DT Editorial Material ID 16S RIBOSOMAL-RNA; HAWAIIAN HYPERSALINE LAKE; SP-NOV.; UNCULTURED MICROORGANISMS; SEQUENCES; PCR; COMMUNITY; BACTERIA; GENES; METAGENOMICS C1 Univ Hawaii, Dept Microbiol, Honolulu, HI 96822 USA. Univ Florida, Space Life Sci Lab, Dept Microbiol & Cell Sci, Kennedy Space Ctr, FL USA. Univ Hawaii, Inst Astron, NASA, Astrobiol Inst, Honolulu, HI 96822 USA. RP Donachie, SP (reprint author), Univ Hawaii, Dept Microbiol, Honolulu, HI 96822 USA. EM donachie@hawaii.edu NR 30 TC 49 Z9 51 U1 1 U2 15 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK STREET, 9TH FLOOR, NEW YORK, NY 10013-1917 USA SN 1751-7362 J9 ISME J JI ISME J. PD JUN PY 2007 VL 1 IS 2 BP 97 EP 99 DI 10.1038/ismej.2007.22 PG 3 WC Ecology; Microbiology SC Environmental Sciences & Ecology; Microbiology GA 206XJ UT WOS:000249215900001 PM 18043618 ER PT J AU Fisher, BL AF Fisher, Brad L. TI Statistical error decomposition of regional-scale climatological precipitation estimates from the tropical rainfall measuring mission (TRMM) SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY LA English DT Article ID GROUND-VALIDATION; SAMPLING ERRORS; PROFILING ALGORITHM; STOCHASTIC-MODEL; UNITED-STATES; SATELLITE; RADAR; UNCERTAINTY; AVERAGES; VARIABILITY AB Monthly rainfall estimates inferred from the NASA Tropical Rainfall Measuring Mission (TRMM) satellite contain errors due to discrete temporal sampling and remote spaceborne rain retrievals. This paper develops a regional-scale error model that uses the rain information in the ground data to disentangle the sampling and retrieval errors in the satellite estimate statistically. The proposed method computes a mean rain rate from monthly rainfall statistics for each TRMM rain sensor by subsampling high-resolution ground-based rain data at satellite overpass times. This additional rain-subsampled parameter plays an essential role in the statistical decomposition of the total error distribution into its sampling and retrieval error components. Using the statistical formalism developed in this study, an error analysis was performed on 5 yr of monthly rain estimates produced by the TRMM Microwave Imager (TMI) and precipitation radar (PR) rain sensors aboard TRMM over a quasi 2 degrees x 2 degrees region of the TRMM ground validation (GV) site at Melbourne, Florida. Annual retrieval and sampling error statistics were computed for the TMI and PR using monthly rainfall estimates derived from two independent ground-based sensors: a regional rain gauge network and the Next-Generation Weather Radar (NEXRAD). Subsampled ground-based rainfall estimates produced for the radar and the gauges were highly correlated with the TMI and PR rainfall estimates, and both GV sensors produced relatively consistent error estimates. The PR-to-TMI sampling error ratio was equal to about 1.3, which was in close agreement with prelaunch predications, and the TMI-to-PR retrieval error ratio was about 2.0. For the TMI, a seasonally alternating rainfall bias was also observed that was negative during winter and positive during summer. C1 NASA, Goddard Space Flight Ctr, Lab Atmospher & Sci Syst & Applicat, Greenbelt, MD 20771 USA. RP Fisher, BL (reprint author), NASA, Goddard Space Flight Ctr, Lab Atmospher & Sci Syst & Applicat, Code 912-1, Greenbelt, MD 20771 USA. EM fisher@radar.gsfc.nasa.gov NR 38 TC 15 Z9 15 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1558-8424 J9 J APPL METEOROL CLIM JI J. Appl. Meteorol. Climatol. PD JUN PY 2007 VL 46 IS 6 BP 791 EP 813 DI 10.1175/JAM2497.1 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 185NT UT WOS:000247718400008 ER PT J AU Cantrell, SA Cantrell, JH Lillehei, PT AF Cantrell, Sean A. Cantrell, John H. Lillehei, Peter T. TI Nanoscale subsurface imaging via resonant difference-frequency atomic force ultrasonic microscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ACOUSTIC MICROSCOPY AB A scanning probe microscope methodology, called resonant difference-frequency atomic force ultrasonic microscopy (RDF-AFUM), has been developed. It employs an ultrasonic wave launched from the bottom of a sample while the cantilever of an atomic force microscope, driven at a frequency differing from the ultrasonic frequency by one of the contact resonance frequencies of the cantilever, engages the sample top surface. The nonlinear mixing of the oscillating cantilever and the ultrasonic wave in the region defined by the cantilever tip-sample surface interaction force generates difference-frequency oscillations at the cantilever contact resonance. The resonance-enhanced difference-frequency signals are used to create images of nanoscale near-surface and subsurface features. An analytical model is presented for assessing the RDF-AFUM phase signal resulting from near-surface variations in the sample contact stiffness and from the interaction of the bulk wave with subsurface structures. The application of the model to RDF-AFUM phase measurements of a 12.7 mu m thick film of LaRC (TM)-CP2 polyimide polymer containing a monolayer of gold nanoparticles embedded 7 mu m below the specimen surface reveals variations in the Young modulus of the material of approximately 24% over regions roughly 10-35 nm wide. The magnitude of the modulus variations suggests the occurrence of contiguous amorphous and crystalline phases within the bulk of the polymer. The RDF-AFUM micrograph indicates a preferential growth of the crystalline phase in the vicinity of the gold nanoparticles. (c) 2007 American Institute of Physics. C1 NASA, Langley Res Ctr, Res & Technol Directorate, Hampton, VA 23665 USA. RP Cantrell, SA (reprint author), Univ Virginia, Dept Phys, Charlottesville, VA 22904 USA. EM sac3k@virginia.edu; john.h.cantrell@nasa.gov; peter.t.lillehei@nasa.gov RI Lillehei, Peter/C-9196-2009 OI Lillehei, Peter/0000-0001-8183-9980 NR 19 TC 31 Z9 31 U1 0 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 2007 VL 101 IS 11 AR 114324 DI 10.1063/1.2743908 PG 8 WC Physics, Applied SC Physics GA 179QW UT WOS:000247306000142 ER PT J AU Suzuki, M Ominami, Y Ngo, Q Yang, CY Cassell, AM Li, J AF Suzuki, Makoto Ominami, Yusuke Ngo, Quoc Yang, Cary Y. Cassell, Alan M. Li, Jun TI Current-induced breakdown of carbon nanofibers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; NANOTUBES; GROWTH; INTERCONNECTS; TRANSPORT; DEVICES; ARRAYS AB We present a study of high-field transport in carbon nanofibers (CNFs) and breakdown phenomena due to current stress. In situ measurements with scanning transmission electron microscopy reveal that the failure mode of CNFs is strongly related to the morphology of graphite layers comprising CNFs. Comparison with carbon nanotube (CNT) breakdown is made, demonstrating that the current capacity of CNFs is described by a similar model as that of CNTs with a modification of the current capacity of each graphitic layer. The maximum current density is correlated with resistivity, leading to the conclusion that lower resistivity results in higher current capacity in CNFs. (c) 2007 American Institute of Physics. C1 Santa Clara Univ, Ctr Nanostruct, Santa Clara, CA 95053 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Suzuki, M (reprint author), Santa Clara Univ, Ctr Nanostruct, Santa Clara, CA 95053 USA. EM m1suzuki@scu.edu RI Li, Jun/H-7771-2013 OI Li, Jun/0000-0002-3689-8946 NR 34 TC 31 Z9 31 U1 0 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 2007 VL 101 IS 11 AR 114307 DI 10.1063/1.2743086 PG 5 WC Physics, Applied SC Physics GA 179QW UT WOS:000247306000125 ER PT J AU Lintault, LM Zakrzewska, EI Maple, RL Baer, LA Casey, TM Ronca, AE Wade, CE Plaut, K AF Lintault, Laura M. Zakrzewska, Elzbieta I. Maple, Rhonda L. Baer, Lisa A. Casey, Theresa M. Ronca, April E. Wade, Charles E. Plaut, Karen TI In a hypergravity environment neonatal survival is adversely affected by alterations in dam tissue metabolism rather than reduced food intake SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE glucose oxidation; metabolizable energy; mammary ID BODY-COMPOSITION; SKELETAL-MUSCLE; CHRONIC CENTRIFUGATION; INSULIN-RECEPTOR; ADIPOSE-TISSUE; RATS; PREGNANCY; LACTATION; ENERGY; LIVER AB Exposure of rat dams to hypergravity during pregnancy is associated with increased pup mortality, reduced food intake, and decreased rates of glucose oxidation and lipogenesis in mammary tissue. We hypothesized that increased pup mortality is due to changes in maternal metabolism and not to reduced food intake of dams. Effects of hypergravity on rate of glucose oxidation and lipogenesis in mammary, liver, and adipose tissue were measured in rat dams centrifuged at 2.0 G [hypergravity (HG)], kept at 1.0 G (control), or fed to match the intake of HG rats (pair fed) from gestation day 11(G 11) until G21 or postpartum day 3 (M). Body weight, percent body fat, metabolizable energy, and nitrogen balance were significantly less in HG dams compared with controls (P < 0.05); however, these factors were not different between HG and pair-fed dams. By P3, 100% of control and pair-fed pups survived, while only 49% of HG pups survived. At G21, rates of glucose oxidation and lipogenesis in mammary and adipose tissue were less in HG than in control and pair-fed dams (P < 0.1 and P < 0.05). In liver, at G21, the rate of lipogenesis was greater in HG than control and pair-fed dams (P < 0.01); at P3, lipogenesis was greater in control than HG and pair-fed dams (P < 0.05). Gene expression of ATP citrate lyase, acetyl-CoA carboxylase, and fatty acid synthase increased in liver from pregnancy to lactation in control and pair-fed dams but not HG dams. Thus reduced food intake and body mass due to hypergravity exposure cannot explain the dramatic decrease in HG pup survival. C1 Univ Vermont, Dept Anim Sci, Burlington, VT 05405 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Casey, TM (reprint author), Michigan State Univ, Dept Anim Sci, E Lansing, MI 48824 USA. EM ande1218@msu.edu OI Casey, Theresa/0000-0002-8835-3550 NR 39 TC 9 Z9 9 U1 0 U2 1 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 JUN PY 2007 VL 102 IS 6 BP 2186 EP 2193 DI 10.1152/japplphysiol.01015.2006 PG 8 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 195KJ UT WOS:000248410800017 PM 17317876 ER PT J AU Patel, MJ Liu, W Sykes, MC Ward, NE Risin, SA Risin, D Jo, H AF Patel, Mamta J. Liu, Wenbin Sykes, Michelle C. Ward, Nancy E. Risin, Semyon A. Risin, Diana Jo, Hanjoong TI Identification of mechanosensitive genes in osteoblasts by comparative microarray studies using the rotating wall vessel and the random positioning machine SO JOURNAL OF CELLULAR BIOCHEMISTRY LA English DT Article DE bone formation; alkaline phosphatase; RWV RPM; microgravity; osteoblasts ID SPACE-FLIGHT; MODELED MICROGRAVITY; PROTEIN-KINASE; BONE; EXPRESSION; DIFFERENTIATION; SIGNALS; CELLS; MICE; SPACEFLIGHT AB Weightlessness or microgravity of spaceflight induces bone loss due in part to decreased bone formation by unknown mechanisms. Due to difficulty in performing experiments in space, several ground-based simulators such as the Rotating Wall Vessel (RWV) and Random Positioning Machine (RPM) have become critical venues to continue studying space biology. However, these simulators have not been systematically compared to each other or to mechanical stimulating models. Here, we hypothesized that exposure to RWV inhibits differentiation and alters gene expression profiles of 2T3 cells, and a subset of these mechanosensitive genes behaves in a manner consistent to the RPM and opposite to the trends incurred by mechanical stimulation of mouse tibiae. Exposure of 2T3 preosteoblast cells to the RWV for 3 days inhibited alkaline phosphatase activity, a marker of differentiation, and downregulated 61 and upregulated 45 genes by more than twofold compared to static 1 g controls, as shown by microarray analysis. The microarray results were confirmed by real-time PCR and/or Western blots for seven separate genes and proteins including osteomodulin, runx2, and osteoglycin. Comparison of the RWV data to the RPM microarray study that we previously published showed 14 mechanosensitive genes that changed in the same direction. Further comparison of the RWV and RPM results to microarray data from mechanically loaded mouse tibiae reported by an independent group revealed that three genes including osteoglycin were upregulated by the loading and downregulated by our simulators. These mechanosensitive genes may provide novel insights into understanding the mechanisms regulating bone formation and potential targets for countermeasures against decreased bone formation during space flight and in pathologies associated with lack of bone formation. C1 Georgia Tech, Wallace H Coulter Dept Biomed Engn, Georgia Inst Technol, Atlanta, GA 30322 USA. Emory Univ, Atlanta, GA 30322 USA. NASA, Lyndon B Johnson Space Ctr, Human Adapt & Countermeasures Off, Houston, TX 77058 USA. MD Anderson Med Ctr, Dept Biostat & Appl Math, Houston, TX 77030 USA. Univ Texas, Houston Med Sch, Dept Pathol & Lab Med, Houston, TX 77030 USA. Emory Univ, Sch Med, Div Cardiol, Atlanta, GA 30322 USA. RP Jo, H (reprint author), Georgia Tech, Wallace H Coulter Dept Biomed Engn, Georgia Inst Technol, 2005 WMB, Atlanta, GA 30322 USA. EM diana.risin-1@nasa.gov; hanjoongjo@bme.gatech.edu FU NHLBI NIH HHS [HL075209, HL71014] NR 40 TC 34 Z9 45 U1 1 U2 5 PU WILEY-LISS PI HOBOKEN PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0730-2312 J9 J CELL BIOCHEM JI J. Cell. Biochem. PD JUN 1 PY 2007 VL 101 IS 3 BP 587 EP 599 DI 10.1002/jcb.21218 PG 13 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 162XS UT WOS:000246123400006 PM 17243119 ER PT J AU Gordon, AL Visbeck, M Comiso, JC AF Gordon, Arnold L. Visbeck, Martin Comiso, Josefino C. TI A possible link between the Weddell Polynya and the Southern Annular Mode SO JOURNAL OF CLIMATE LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; WINTER MIXED LAYER; SEA-ICE EXTENT; MAUD RISE; DEEP-WATER; EXTRATROPICAL CIRCULATION; SYNCHRONOUS VARIABILITY; OVERTURNING CIRCULATION; HEMISPHERE ATMOSPHERE; OCEAN AB Shortly after the advent of the first imaging passive microwave sensor on board a research satellite an anomalous climate feature was observed within the Weddell Sea. During the years 1974-1976, a 250 x 10(3) km(2) area within the seasonal sea ice cover was virtually free of winter sea ice. This feature, the Weddell Polynya, was created as sea ice formation was inhibited by ocean convection that injected relatively warm deep water into the surface layer. Though smaller, less persistent polynyas associated with topographically induced upwelling at Maud Rise frequently form in the area, there has not been a reoccurrence of the Weddell Polynya since 1976. Archived observations of the surface layer salinity within the Weddell gyre suggest that the Weddell Polynya may have been induced by a prolonged period of negative Southern Annular Mode (SAM). During negative SAM the Weddell Sea experiences colder and drier atmospheric conditions, making for a saltier surface layer with reduced pycnocline stability. This condition enables Maud Rise upwelling to trigger sustained deep-reaching convection associated with the polynya. Since the late 1970s SAM has been close to neutral or in a positive state, resulting in warmer, wetter conditions over the Weddell Sea, forestalling repeat of the Weddell Polynya. A contributing factor to the Weddell Polynya initiation may have been a La Nina condition, which is associated with increased winter sea ice formation in the polynya area. If the surface layer is made sufficiently salty due to a prolonged negative SAM period, perhaps aided by La Nina, then Maud Rise upwelling meets with positive feedback, triggering convection, and a winter persistent Weddell Polynya. C1 Lamont Doherty Earth Observ, Palisades, NY 10964 USA. IFM, GEOMAR, Leibniz Inst Marine Sci, Kiel, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gordon, AL (reprint author), Lamont Doherty Earth Observ, 61 Route 9W, Palisades, NY 10964 USA. EM agordon@ldeo.columbia.edu RI Gordon, Arnold/H-1049-2011; Visbeck, Martin/G-2461-2011; Visbeck, Martin/B-6541-2016 OI Gordon, Arnold/0000-0001-6480-6095; Visbeck, Martin/0000-0002-0844-834X; Visbeck, Martin/0000-0002-0844-834X NR 52 TC 28 Z9 29 U1 2 U2 13 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 JUN 1 PY 2007 VL 20 IS 11 BP 2558 EP 2571 DI 10.1175/JCLI4046.1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 177NH UT WOS:000247159300014 ER PT J AU Teo, BK Sun, XH AF Teo, Boon K. Sun, X. H. TI Classification and representations of low-dimensional nanomaterials: Terms and symbols SO JOURNAL OF CLUSTER SCIENCE LA English DT Article DE low-dimensional nanomaterials; terms and symbols ID WALLED CARBON NANOTUBES; PASSIVATED SILICON NANOWIRES; LARGE-SCALE SYNTHESIS; CHARGE-TRANSFER; SI(100)-(2X1) SURFACES; SONOCHEMICAL REACTIONS; ELECTRONIC-STRUCTURE; AMBIENT CONDITIONS; BIAXIAL NANOWIRES; IMINE) DENDRIMERS AB A simple scheme, with special terms and symbols useful in categorizing various nanostructures, is introduced. Using "n-D in/on m-D" composite nanomaterials where n,m <= 2 as examples, we illustrate how these terms and symbols can be used to represent various hetero nanostructures. This simple nomenclature system also allows a systematization of a wide variety of multi-dimensional nanocomposite heterostructures. C1 Univ Western Ontario, Dept Chem, London, ON, Canada. Univ Illinois, Dept Chem, Chicago, IL 60607 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Teo, BK (reprint author), Univ Western Ontario, Dept Chem, London, ON, Canada. EM boonkteo@uic.edu; xsun@arc.nasa.gov RI Sun, Xuhui /K-5689-2012 NR 50 TC 5 Z9 5 U1 4 U2 8 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1040-7278 J9 J CLUST SCI JI J. Clust. Sci. PD JUN PY 2007 VL 18 IS 2 BP 346 EP 357 DI 10.1007/s10876-007-0125-x PG 12 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 191ZW UT WOS:000248171500002 ER PT J AU Bassim, ND Twigg, ME Mastro, MA Eddy, CR Zega, TJ Henry, RL Culbertson, JC Holm, RT Neudeck, P Powell, JA Trunek, AJ AF Bassim, N. D. Twigg, M. E. Mastro, M. A. Eddy, C. R., Jr. Zega, T. J. Henry, R. L. Culbertson, J. C. Holm, R. T. Neudeck, P. Powell, J. A. Trunek, A. J. TI Dislocations in III-nitride films grown on 4H-SiC mesas with and without surface steps SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE interfaces; line defects; nucleation; metalorganic vapor phase epitaxy; nitrides; semiconducting gallium compounds ID CRITICAL THICKNESS; GAN; LAYERS; TEMPERATURE; NUCLEATION; STRESS; MISFIT; CRYSTALS; EPITAXY; STRAIN AB Using transmission electron microscopy, we have analyzed dislocations in AlN nucleation layers and GaN films deposited by metalorganic vapor phase epitaxy on the (0 0 0 1) surface of epitaxially grown 4H-SiC mesas with and without steps. For 4H-SiC substrates free of SiC surface steps, half-loop nucleation and glide parallel to the AIN/SiC interfacial plane play the dominant role in strain relief, with no mechanism for generating threading dislocations. In contrast, 4H-SiC mesa surfaces with steps give rise to regions of high stress at the heteroepitaxial interface, thereby providing an environment conducive to the nucleation and growth of threading dislocations, which act to accommodate misfit strain by the tilting of threading edge dislocations. We compare the excess stress associated with strain relief for each mechanism and find that the driving force for plastic flow is much greater for threading dislocation tilt than for half-loop propagation. (C) 2007 Elsevier B.V. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Sest Inc, Cleveland, OH 44135 USA. OAI, Cleveland, OH 44135 USA. RP Twigg, ME (reprint author), USN, Res Lab, Washington, DC 20375 USA. EM twigg@estd.nrl.navy.mil NR 27 TC 5 Z9 5 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JUN 1 PY 2007 VL 304 IS 1 BP 103 EP 107 DI 10.1016/j.jcrysgro.2007.02.007 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 178PF UT WOS:000247231900019 ER PT J AU Hullavarad, SS Pugel, DE Jones, EB Vispute, RD Venkatesan, T AF Hullavarad, S. S. Pugel, D. E. Jones, E. B. Vispute, R. D. Venkatesan, T. TI Low leakage current transport and high breakdown strength of pulsed laser deposited HfO2/SiC metal-insulator-semiconductor device structures SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE high k dielectric; passivation; pulsed laser deposition (PLD); x-ray photoelectron spectroscopy (YPS); current-voltage (I-V); capacitance-voltage (C-V) ID CHEMICAL-VAPOR-DEPOSITION; THIN-FILMS; GATE DIELECTRICS; SILICON-CARBIDE; SI; STABILITY; SUBSTRATE; HAFNIUM; ISSUES; OXIDES AB Hafnium oxide (HfO2) thin films were deposited by the pulsed laser deposition (PLD) method on SiC substrates. The bandgap of HfO2 thin films was observed to be 5.8 eV. The chemical nature and stoichiometry of the films were analyzed by x-ray photoelectron spectroscopy (XPS). Metal-insulator-semiconductor (MIS) structures with Ni as a top electrode and TiN as a bottom electrode were fabricated to study the leakage current properties. The devices exhibited leakage current density of 50 nA/cm(2). The dielectric constant of these films is estimated to be in the range 17-24 from capacitance-voltage (C-V) measurements. The frequency dependence of the interface trapped charges is studied. C1 Univ Alaska, Off Elect Miniaturizat, Fairbanks, AK 99701 USA. Univ Maryland, Ctr Supercond Res, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Detector Dev Branch, Greenbelt, MD 20770 USA. RP Hullavarad, SS (reprint author), Univ Alaska, Off Elect Miniaturizat, Fairbanks, AK 99701 USA. EM fnssh1@uaf.edu RI Venkatesan, Thirumalai/E-1667-2013 NR 29 TC 16 Z9 16 U1 1 U2 9 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD JUN PY 2007 VL 36 IS 6 BP 648 EP 653 DI 10.1007/s11664-006-0007-2 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 178BP UT WOS:000247196500005 ER PT J AU Trigwell, S Boucher, D Calle, CI AF Trigwell, Steve Boucher, Derrick Calle, Carlos I. TI Electrostatic properties of PE and PTFE subjected to atmospheric pressure plasma treatment; correlation of experimental results with atomistic modeling SO JOURNAL OF ELECTROSTATICS LA English DT Article; Proceedings Paper CT Joint Conference of the Electrostatics-Society-of-America/IEEE-Industrial-Applications-Society/I nstitute-of-Electrostatics-Japan/Societe-Francaise-of-Electrostatique CY JUN 06-09, 2006 CL Berkeley, CA SP Electrostat Soc Amer, IEEE Ind Applicat Soc, Inst Electrostat Japan, Soc Francaise Electrostat DE triboelectrification; hydrophilic; atmospheric plasma; surface treatment; atomistic modeling ID POLYMERS; HELIUM; STATES AB The use of an atmospheric pressure glow discharge (APGD) plasma was used at Kennedy Space Center (KSC) to increase the hydrophilicity of spaceport materials to enhance their surface charge dissipation and prevent possible electrostatic discharge (ESD) in spaceport operations. Significant decreases in charge decay times were observed after tribocharging the materials using the standard KSC tribocharging test. The polarity and amount of charge transferred was dependant upon the effective work function differences between the respective materials. In this study, PE and PTFE were exposed to a He + O-2 APGD. The pre and post-treatment surface chemistries were analyzed by X-ray photoelectron spectroscopy and contact angle measurements. Semi-empirical and ab initio calculations were performed to correlate the experimental results with some plausible molecular and electronic structure features of the oxidation process. For the PE. significant surface oxidation was observed, as indicated by XPS showing C-O, C=O, and O-C=O bonding, and a decrease in the surface contact angle from 98.9 degrees to 61.2 degrees. For the PTFE, no C-O bonding appeared and the surface contact angle increased indicating the APGD only succeeded in cleaning the PTFE surface without affecting the surface structure. The calculations using the Parametric Method 3 (PM3) and Density Function Theory (DFT) methods were performed on single and multiple oligomers to simulate a wide variety of oxidation scenarios. Calculated work function results suggest that regardless of oxidation mechanism, e.g. -OH, =O or a combination thereof, the experimentally observed levels of surface oxidation are unlikely to lead to a significant change in the electronic structure of PE and that its increased hydrophilic properties are the primary reason for the observed changes in its electrostatic behavior. The calculations for PTFE argue strongly against significant oxidation of that material. as confirmed by the XPS results. (C) 2006 Elsevier B.V. All rights reserved. C1 ARSC Aerosp, Electrostat & Surface Phys Lab, Kennedy Space Ctr, FL 32899 USA. Kings Coll, Dept Chem & Phys, Wilkes Barre, PA 18711 USA. NASA, Electrostat & Surface Phys Lab, Kennedy Space Ctr, FL 32899 USA. RP Trigwell, S (reprint author), ARSC Aerosp, Electrostat & Surface Phys Lab, ASRC-20, Kennedy Space Ctr, FL 32899 USA. EM steven.trigwell-1@ksc.nasa.gov NR 17 TC 7 Z9 9 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3886 EI 1873-5738 J9 J ELECTROSTAT JI J. Electrost. PD JUN PY 2007 VL 65 IS 7 BP 401 EP 407 DI 10.1016/j.elstat.2006.10.004 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA 171NX UT WOS:000246743800001 ER PT J AU Schuh, H Ma, C Nothnagel, A AF Schuh, H. Ma, C. Nothnagel, A. TI Special issue: Very long baseline interferometry (VLBI) - Preface SO JOURNAL OF GEODESY LA English DT Editorial Material C1 Vienna Univ Technol, Inst Geodesy & Geophys, A-1040 Vienna, Austria. NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. Univ Bonn, Geodatisches Inst, D-53115 Bonn, Germany. RP Schuh, H (reprint author), Vienna Univ Technol, Inst Geodesy & Geophys, Gusshausstr 27-29, A-1040 Vienna, Austria. EM harald.schuh@tuwien.ac.at; Chopo.Ma@nasa.gov; nothnagel@uni-bonn.de RI Ma, Chopo/D-4751-2012 NR 0 TC 0 Z9 0 U1 0 U2 3 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 2007 VL 81 IS 6-8 BP 377 EP 378 DI 10.1007/s00190-007-0149-x PG 2 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 182CO UT WOS:000247482900001 ER PT J AU Schluter, W Behrend, D AF Schlueter, Wolfgang Behrend, Dirk TI The International VLBI Service for Geodesy and Astrometry (IVS): Current capabilities and future prospects SO JOURNAL OF GEODESY LA English DT Article DE International VLBI Service for Geodesy and Astrometry (IVS); Very Long Baseline Interferometry (VLBI); Earth orientation parameters (EOP); Terrestrial reference frame (TRF); Celestial reference frame (CRF) AB Very Long Baseline Interferometry (VLBI) plays a unique and fundamental role in the maintenance of the global (terrestrial and celestial) reference frames, which are required for precise positioning in many research areas such as the understanding and monitoring of global changes, and for space missions. The International VLBI Service for Geodesy and Astrometry (IVS) coordinates the global VLBI components and resources on an international basis. The service is tasked by the International Association of Geodesy (IAG) and International Astronomical Union (IAU) to provide products for the realization of the Celestial Reference Frame (CRF) through the positions of quasars, to deliver products for the maintenance of the terrestrial reference frame (TRF), such as station positions and their changes with time, and to generate products describing the rotation and orientation of the Earth. In particular, VLBI uniquely provides direct observations of nutation parameters and of the time difference UT1-UTC. This paper summarizes the evolution and current status of the IVS. It points out the activities to improve further on the product quality to meet future service requirements. C1 Bundesamt Kartog & Geodasie, Fundamentalstn Wettzell, D-93444 Kotzting, Germany. NVI Inc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Schluter, W (reprint author), Bundesamt Kartog & Geodasie, Fundamentalstn Wettzell, Sackenrieder Str 25, D-93444 Kotzting, Germany. EM schlueter@fs.wettzell.de; dbb@ivscc.gsfc.nasa.gov NR 22 TC 98 Z9 101 U1 1 U2 3 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 2007 VL 81 IS 6-8 BP 379 EP 387 DI 10.1007/s00190-006-0131-z PG 9 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 182CO UT WOS:000247482900002 ER PT J AU MacMillan, DS Ma, C AF MacMillan, D. S. Ma, C. TI Radio source instability in VLBI analysis SO JOURNAL OF GEODESY LA English DT Article DE VLBI; source stability; terrestrial reference frame; earth orientation parameters ID BASE-LINE INTERFEROMETRY; CELESTIAL REFERENCE FRAME; ASTROMETRIC SUITABILITY AB The source position time-series for many of the frequently observed radio sources in the NASA geodetic very long baseline interferometry (VLBI) program show systematic linear and non-linear variations of as much as 0.5 mas (milli-arc-seconds) to 1.0 mas, due mainly to source structure changes. In standard terrestrial reference frame (TRF) geodetic solutions, it is a common practice to only estimate a global source position for each source over the entire history of VLBI observing sessions. If apparent source position variations are not modeled, they produce corresponding systematic variations in estimated Earth orientation parameters (EOPs) at the level of 0.02-0.04 mas in nutation and 0.01-0.02 mas in polar motion. We examine the stability of position time-series of the 107 radio sources in the current NASA geodetic source catalog since these sources have relatively dense observing histories from which it is possible to detect systematic variations. We consider different strategies for handling source instabilities where we (1) estimate the positions of unstable sources for each session they are observed, or (2) estimate spline parameters or rate parameters for sources chosen to fit the specific variation seen in the position-time series. We found that some strategies improve VLBI EOP accuracy by reducing the biases and weighted root mean square differences between measurements from independent VLBI networks operating simultaneously. We discuss the problem of identifying frequently observed unstable sources and how to identify new sources to replace these unstable sources in the NASA VLBI geodetic source catalog. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NVI Inc, Greenbelt, MD 20771 USA. RP MacMillan, DS (reprint author), NASA, Goddard Space Flight Ctr, Code 698, Greenbelt, MD 20771 USA. EM dsm@gemini.gsfc.nasa.gov; cma@gemini.gsfc.nasa.gov RI Ma, Chopo/D-4751-2012 NR 13 TC 10 Z9 10 U1 0 U2 0 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 2007 VL 81 IS 6-8 BP 443 EP 453 DI 10.1007/s00190-007-0136-2 PG 11 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 182CO UT WOS:000247482900008 ER PT J AU Heinkelmann, R Boehm, J Schuh, H Bolotin, S Engelhardt, G MacMillan, DS Negusini, M Skurikhina, E Tesmer, V Titov, O AF Heinkelmann, R. Boehm, J. Schuh, H. Bolotin, S. Engelhardt, G. MacMillan, D. S. Negusini, M. Skurikhina, E. Tesmer, V. Titov, O. TI Combination of long time-series of troposphere zenith delays observed by VLBI SO JOURNAL OF GEODESY LA English DT Article DE troposphere delays; intra-technique combination; VLBI ID CELESTIAL REFERENCE FRAME; BASE-LINE INTERFEROMETRY; MAPPING FUNCTIONS; WET DELAYS; GPS; RADIOMETER; GRADIENTS; WATER AB Within the International Very Long Baseline Interferometry (VLBI) Service for Geodesy and Astrometry (IVS), long time-series of zenith wet and total troposphere delays have been combined at the level of parameter estimates. The data sets were submitted by eight IVS Analysis Centers (ACs) and cover January 1984 to December 2004. In this paper, the combination method is presented and the time-series submitted by the eight IVS ACs are compared with each other. The combined zenith delays are compared with time-series provided by the International Global Navigation Satellite System (GNSS) Service (IGS), and with zenith delays derived from the European Centre for Medium-Range Weather Forecasts (ECMWF). Before the combination, outliers are eliminated from the individual time-series using the robust BIBER (bounded influence by standardized residuals) estimator. For each station and AC, relative weight factors are obtained by variance component estimation. The mean bias of the IVS ACs' time-series with respect to the IVS combined time-series is 0.89 mm and the mean root mean square is 7.67 mm. Small differences between stations and ACs can be found, which are due to the inhomogeneous analysis options, different parameterizations, and different treatment of missing in-situ pressure records. Compared to the IGS zenith total delays, the combined IVS series show small positive mean biases and different long-term trends. Zenith wet delays from the ECMWF are used to validate the IVS combined series. Inconsistencies, e.g., long-term inhomogeneity of the in-situ pressure data used for the determination of VLBI zenith delays, are identified. C1 Vienna Univ Technol, Inst Geodesy & Geophys, A-1040 Vienna, Austria. Natl Acad Sci Ukraine, Main Astron Observ, UA-03680 Kiev, Ukraine. Bundesamt Kartog & Geodasie BKG, D-04105 Leipzig, Germany. NVI Inc, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ist Nazl Astrofis INAF, Ist Radioastron, I-40129 Bologna, Italy. IAA, St Petersburg 191187, Russia. Deutsch Geodatisches Forschunginst DGFI, D-80539 Munich, Germany. Geosci Australia, Canberra, ACT 2601, Australia. RP Heinkelmann, R (reprint author), Vienna Univ Technol, Inst Geodesy & Geophys, Gusshausstr 27-29, A-1040 Vienna, Austria. EM rob@mars.hg.tuwien.ac.at; bolotin@mao.kiev.ua; gerald.engelhardt@bkg.bund.de; dsm@leo.gsfc.nasa.gov; negusini@ira.inaf.it; sea@ipa.nw.ru; tesmer@dgfi.badw.de; Oleg.Titov@ga.gov.au RI Bohm, Johannes/H-9161-2013; Negusini, Monia/N-6493-2015 OI Bohm, Johannes/0000-0002-1208-5473; Negusini, Monia/0000-0002-0064-5533 NR 49 TC 15 Z9 17 U1 0 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0949-7714 J9 J GEODESY JI J. Geodesy PD JUN PY 2007 VL 81 IS 6-8 BP 483 EP 501 DI 10.1007/s00190-007-0147-z PG 19 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 182CO UT WOS:000247482900012 ER PT J AU Glotch, TD Rogers, AD AF Glotch, Timothy D. Rogers, A. Deanne TI Evidence for aqueous deposition of hematite- and sulfate-rich light-toned layered deposits in Aureum and Iani Chaos, Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID THERMAL EMISSION SPECTROMETER; MERIDIANI-PLANUM; OPPORTUNITY ROVER; LANDING SITE; CRYSTALLINE HEMATITE; TERRA-MERIDIANI; LASER ALTIMETER; BURNS FORMATION; SPECTRAL DATA; SOILS AB Two new gray hematite-rich units have been found in Aureum and Iani Chaos, Mars, using data acquired by the Mars Global Surveyor Thermal Emission Spectrometer. These regions correspond with light-toned sulfate-rich deposits identified by the European Space Agency's OMEGA visible/near-IR spectrometer. Much of the light-toned material in Aureum and Iani Chaos is in the form of a capping unit similar to that seen in Aram Chaos. However, some light-toned material is also seen within the chaotic mounds, indicating that it was present before the formation of the chaotic terrains. The stratigraphy of the units in Iani and Aureum Chaos suggests that the capping and hematite-rich units must have been deposited after the formation of the chaotic terrains in the mid to late Hesperian, up to 1 Gyr after the formation of the light-toned outcrop in Meridiani Planum. The geologic contexts of these and other hematite- and sulfate-rich units in Aram Chaos, Valles Marineris, and Meridiani Planum indicate that they likely formed in similar environments under aqueous conditions. If this is the case, it suggests an active hydrological cycle lasting from the late Noachian to the late Hesperian. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Glotch, TD (reprint author), CALTECH, Div Geol & Planetary Sci, MC 150-21, Pasadena, CA 91125 USA. EM tglotch@gps.caltech.edu RI Glotch, Timothy/B-6829-2008; Rogers, Deanne/I-9737-2016 OI Rogers, Deanne/0000-0002-4671-2551 NR 67 TC 46 Z9 46 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD JUN 1 PY 2007 VL 112 IS E6 AR E06001 DI 10.1029/2006JE002863 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 174NT UT WOS:000246949700001 ER PT J AU Lee, MI Schubert, SD Suarez, MJ Held, IM Lau, NC Ploshay, JJ Kumar, A Kim, HK Schemm, JKE AF Lee, Myong-In Schubert, Siegfried D. Suarez, Max J. Held, Isaac M. Lau, Ngar-Cheung Ploshay, Jeffrey J. Kumar, Arun Kim, Hyun-Kyung Schemm, Jae-Kyung E. TI An analysis of the warm-season diurnal cycle over the continental united states and northern Mexico in general circulation models SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID LOW-LEVEL JET; MESOSCALE CONVECTIVE COMPLEXES; LARGE-SCALE MODELS; BOUNDARY-LAYER; GREAT-PLAINS; SEMIDIURNAL VARIATIONS; MOISTURE TRANSPORT; HYDROLOGIC-CYCLE; ARAKAWA-SCHUBERT; SOIL-MOISTURE AB The diurnal cycle of warm-season rainfall over the continental United States and northern Mexico is analyzed in three global atmospheric general circulation models (AGCMs) from NCEP, GFDL, and the NASA Global Modeling Assimilation Office (GMAO). The results for each model are based on an ensemble of five summer simulations forced with climatological sea surface temperatures. Although the overall patterns of time-mean (summer) rainfall and low-level winds are reasonably well simulated, all three models exhibit substantial regional deficiencies that appear to be related to problems with the diurnal cycle. Especially prominent are the discrepancies in the diurnal cycle of precipitation over the eastern slopes of the Rocky Mountains and adjacent Great Plains, including the failure to adequately capture the observed nocturnal peak. Moreover, the observed late afternoon-early evening eastward propagation of convection from the mountains into the Great Plains is not adequately simulated, contributing to the deficiencies in the diurnal cycle in the Great Plains. In the southeast United States, the models show a general tendency to rain in the early afternoon-several hours earlier than observed. Over the North American monsoon region in the southwest United States and northern Mexico, the phase of the broad-scale diurnal convection appears to be reasonably well simulated, though the coarse resolution of the runs precludes the simulation of key regional phenomena. All three models employ deep convection schemes that assume fundamentally the same buoyancy closure based on simplified versions of the Arakawa-Schubert scheme. Nevertheless, substantial differences between the models in the diurnal cycle of convection highlight the important differences in their implementations and interactions with the boundary layer scheme. An analysis of local diurnal variations of convective available potential energy (CAPE) shows an overall tendency for an afternoon peak-a feature well simulated by the models. The simulated diurnal cycle of rainfall is in phase with the local CAPE variation over the southeast United States and the Rocky Mountains where the local surface boundary forcing is important in regulating the diurnal cycle of convection. On the other hand, the simulated diurnal cycle of rainfall tends to be too strongly tied to CAPE over the Great Plains, where the observed precipitation and CAPE are out of phase, implying that free atmospheric large-scale forcing plays a more important role than surface heat fluxes in initiating or inhibiting convection. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. NOAA, NCEP, Climate Predict Ctr, Camp Springs, MD USA. RP Lee, MI (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM milee@gmao.gsfc.nasa.gov OI Lee, Myong-In/0000-0001-8983-8624 NR 68 TC 48 Z9 48 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PD JUN PY 2007 VL 8 IS 3 BP 344 EP 366 DI 10.1175/JHM581.1 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 184CU UT WOS:000247619500005 ER PT J AU Hong, Y Gochis, D Cheng, JT Hsu, KL Sorooshian, S AF Hong, Yang Gochis, David Cheng, Jiang-Tao Hsu, Kuo-Lin Sorooshian, Soroosh TI Evaluation of PERSIANN-CCS rainfall measurement using the NAME Event Rain Gauge Network SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID NORTH-AMERICAN MONSOON; GULF-OF-CALIFORNIA; MEXICAN MONSOON; UNITED-STATES; PRECIPITATION; SYSTEM; SURGES; ERROR AB Robust validation of the space-time structure of remotely sensed precipitation estimates is critical to improving their quality and confident application in water cycle-related research. In this work, the performance of the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS) precipitation product is evaluated against warm season precipitation observations from the North American Monsoon Experiment (NAME) Event Rain Gauge Network (NERN) in the complex terrain region of northwestern Mexico. Analyses of hourly and daily precipitation estimates show that the PERSIANN-CCS captures well active and break periods in the early and mature phases of the monsoon season. While the PERSIANN-CCS generally captures the spatial distribution and timing of diurnal convective rainfall, elevation-dependent biases exist, which are characterized by an underestimate in the occurrence of light precipitation at high elevations and an overestimate in the occurrence of precipitation at low elevations. The elevation-dependent biases contribute to a 1-2-h phase shift of the diurnal cycle of precipitation at various elevation bands. For reasons yet to be determined, the PERSIANN-CCS significantly underestimated a few active periods of precipitation during the late or "senescent" phase of the monsoon. Despite these shortcomings, the continuous domain and relatively high spatial resolution of PERSIANN-CCS quantitative precipitation estimates (QPEs) provide useful characterization of precipitation space-time structures in the North American monsoon region of northwestern Mexico, which should prove useful for hydrological applications. C1 Univ Calif Irvine, Dept Civil & Environm Engn, Ctr Hydrometeorol & Remote Sensing, Irvine, CA USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Hong, Y (reprint author), NASA, Goddard Space Flight Ctr, Mail Stop 613-1, Greenbelt, MD 20770 USA. EM yanghong@agnes.gsfc.nasa.gov RI Hong, Yang/D-5132-2009; sorooshian, soroosh/B-3753-2008; Cheng, Jiangtao/H-1136-2014; OI Hong, Yang/0000-0001-8720-242X; sorooshian, soroosh/0000-0001-7774-5113; Cheng, Jiangtao/0000-0002-0897-3937 NR 25 TC 64 Z9 67 U1 5 U2 11 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PD JUN PY 2007 VL 8 IS 3 BP 469 EP 482 DI 10.1175/JHM574.1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 184CU UT WOS:000247619500013 ER PT J AU Miller, FK Brisson, JG AF Miller, F. K. Brisson, J. G. TI Measurements of the superfluid joule-thomson refrigerator using high concentration He-3-He-4 mixtures SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article DE helium mixtures; He-3 -He-4; low temperature refrigeration; helium-3 AB The superfluid Joule-Thomson refrigerator (SJTR) uses a liquid superfluid He-3-He-4 mixture to provide cooling below 1 K. Performance measurements of the SJTR using 5% and 11% He-3 concentration mixtures are reported. High concentration operation shows higher cooling powers at high temperature. Ultimate temperatures are seen to increase with increasing concentration due to a pinching of the temperature defect in the recuperative heat exchanger. This pinching effect is due to the variation of the heat capacity of the He-3-He-4 mixture with temperature and concentration and is discussed in detail and design changes are suggested to mitigate it. C1 MIT, Dept Mech Engn, Cryogen Engn Lab, Cambridge, MA 02139 USA. RP Miller, FK (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM brisson@mit.edu RI Miller, Franklin/S-3931-2016 OI Miller, Franklin/0000-0001-5942-1991 NR 10 TC 5 Z9 5 U1 1 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD JUN PY 2007 VL 147 IS 5-6 BP 559 EP 578 DI 10.1007/s10909-007-9343-8 PG 20 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 166DI UT WOS:000246357100003 ER PT J AU Tucker, DS Lapointe, MR Jia, ZY AF Tucker, Dennis S. Lapointe, Michael R. Jia, Zhiyong TI The effects of a magnetic field on the crystallization of a fluorozirconate glass SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID INORGANIC SALTS; CRYSTAL-GROWTH; TRANSPORT; ALLOY; FLOW AB An axial magnetic field of 0.1 T was applied to ZrF4- BaF2-LaF3 AlF3NaF fibers during heating to the glass crystallization temperature. Scanning electron microscopy and x-ray diffraction were used to identify crystal phases. It was shown that fibers exposed to the magnetic field did not crystallize, while fibers not exposed to the field did crystallize. A hypothesis based on magnetic work was proposed to explain the results, and was tested by measuring the magnetic susceptibilities of the glass and crystal. C1 George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, MINT Ctr, Tuscaloosa, AL 35487 USA. RP Tucker, DS (reprint author), George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM dr.dennis.tucker@nasa.gov RI Jia, Zhiyong/B-2143-2010 OI Jia, Zhiyong/0000-0002-0116-7166 NR 21 TC 2 Z9 2 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUN PY 2007 VL 22 IS 6 BP 1431 EP 1434 DI 10.1557/JMR.2007.0209 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 175ZX UT WOS:000247053600001 ER PT J AU Ranasinghe, KS Ray, CS Day, DE Rogers, JR Hyers, RW Rathz, T AF Ranasinghe, K. S. Ray, C. S. Day, D. E. Rogers, J. R. Hyers, R. W. Rathz, T. TI Containerless processing of a lithium disilicate glass SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID CRYSTALLIZATION KINETICS; HETEROGENEOUS NUCLEATION; ELECTROSTATIC LEVITATOR; CRYSTAL NUCLEATION; THERMAL-ANALYSIS; SILICA GLASSES; PLATINUM; GROWTH; TEMPERATURE; RATES AB Glasses of Li2O center dot 2SiO(2) (LS2), and LS2 doped with 0.001 wt% platinum (LS2 + 0-001 wt% Pt) compositions were melted, cooled and reheated at controlled rates while levitated (containerless) inside an electrostatic levitator (ESL) furnace at the NASA Marshall Space Flight Center. The experiments were conducted in vacuum using spherical, 2.5-3 mm diameter, glass samples. The measured critical cooling rate for glass formation, R-c, for the LS2 and LS2 + 0.001 wt% Pt glasses processed at ESL were 14 +/- 2 degrees C/ min and 130 +/- 5 degrees C/min, respectively. The values of R-c for the same LS2 and LS2 + 0-001 wt% Pt glasses processed in a container were 62 +/- 3 degrees C/min and 162 +/- 5 degrees C/min, respectively. The effective activation energy for crystallization, E, for this LS2 glass processed without a container at ESL, was higher than that for an identical glass processed in a container. These results suggest that the glass formation tendency for a containerless LS2 melt is significantly increased compared to an identical melt in contact with a container. The absence of heterogeneous nucleation sites that are inherently present in all melts held in containers is believed to be the reason for the increased glass forming tendency of this containerless melt. C1 No Kentucky Univ, Dept Phys & Geol, Highland Hts, KY 41099 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Missouri, Grad Ctr Mat Res, Rolla, MO 65409 USA. Univ Massachusetts, Dept Mech & Ind Engn, Amherst, MA 01003 USA. Univ Alabama, Huntsville, AL 35899 USA. RP Ranasinghe, KS (reprint author), No Kentucky Univ, Dept Phys & Geol, Nunn Dr, Highland Hts, KY 41099 USA. EM ranasinghk1@nku.edu RI Hyers, Robert/G-3755-2010 NR 34 TC 5 Z9 5 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUN PY 2007 VL 42 IS 12 BP 4291 EP 4297 DI 10.1007/s10853-006-1232-z PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 180XW UT WOS:000247402300022 ER PT J AU Ma, Q Tipping, RH Boulet, C Thibault, F Bonamy, J AF Ma, Q. Tipping, R. H. Boulet, C. Thibault, F. Bonamy, J. TI Vibration-dependent trajectories and their effects on vibrational dephasing SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article; Proceedings Paper CT 19th International Conference on High Resolution Molecular Spectroscopy (PRAHA 2006) CY AUG 29-SEP 02, 2006 CL Prague, CZECH REPUBLIC DE vibrational dephasing; trajectory models; pressure broadening and shifting; H-2-He Raman widths and shifts ID LINE-SHAPE PARAMETERS; SEMICLASSICAL CALCULATIONS; QUANTUM; TEMPERATURE; RELAXATION; MIXTURES; THEOREM AB We show that the expression for S-1 (i.e., the first term in the expansion of the S matrix) that is essential in calculating vibration-rotation pressure-broadened shifts is not properly given in the usual Robert-Bonamy (RB) formalism. The problem resulted when they considered effects of the vibrational dephasing on SI; they tacitly made an assumption that the trajectories of interest are vibrationally independent. As a result, the current RB expression is an approximate one. Based on a vibration-dependent trajectory model, which is physically sound, we derive the correct expression for St. We present numerical calculations of the broadening and shifting cross sections and of the line shape parameters for the H-2-He pair and find for this molecular system, new results differ significantly from those calculated using the existing formalism. In addition, by comparing with those derived from close coupling calculations, we find that the new results are better than the old ones. Finally, we discuss how important effects from this modification could be for other molecular systems. We conclude that for certain molecular systems where the short-range collisions are the dominant source responsible for the line widths and shifts, and in addition, the isotropic potential has small depth, the present modification is a worthwhile step to be taken in order to refine the current RB formalism. Meanwhile, for other systems it may not be necessary. (C) 2007 Elsevier Inc. All rights reserved. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA. Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Univ Paris 11, Photophys Mol Lab, CNRS, UPR 3361, F-91405 Orsay, France. Univ Rennes 1, Lab Phys Atomes Laser Mol & Surfaces, CNRS, UMR 6627, F-35042 Rennes, France. Univ Franche Comte, Phys Mol Lab, CNRS, UMR 6624, F-25030 Besancon, France. RP Ma, Q (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM qma@giss.nasa.gov RI Thibault, Franck/A-8439-2008 NR 18 TC 8 Z9 8 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 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUN PY 2007 VL 243 IS 2 BP 105 EP 112 DI 10.1016/j.jms.2007.01.003 PG 8 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 197UV UT WOS:000248582900002 ER PT J AU Zhao, YH Liu, AK AF Zhao, Yunhe Liu, Antony K. TI Arctic sea-ice motion and its relation to pressure field SO JOURNAL OF OCEANOGRAPHY LA English DT Article DE Arctic sea-ice motion; wavelet analysis; multi-sensor approach; satellite data; buoy data; circulation regimes; winter-to-winter variability; relations to the pressure field and the Arctic oscillation indexes ID WAVELET ANALYSIS; SATELLITE DATA; OSCILLATION; SSM/I; DRIFT AB Daily Arctic sea-ice motion maps during the winter seasons (December-March) from December 1988 to March 2003 derived from NSCAT, QuikSCAT, SSM/I, and AMSR-E data by a wavelet analysis method have been merged with those derived from buoy data. These merged sea-ice motion data have been used to study the circulation regimes and winter-to-winter variability of Arctic sea-ice motion. The relation between sea-ice motion and the pressure field in the Arctic Ocean was also studied by applying Principal Component Analysis (PCA) to the monthly merged sea-ice motion data and the monthly pressure field data from IABP. The mean Arctic sea-ice motion map of the 15 winter seasons has two distinct features: the Beaufort Gyre and a cyclonic circulation system in the Eurasian Basin, which moves ice from the Lapte v Sea to Fram Strait. The strengths and sizes of the two features change from one winter season to another. Seasons with a strong or normal Beaufort Gyre alternate with seasons with a weak or no Beaufort Gyre every one to three seasons. The principal components of the first two modes of PCA of the monthly sea-ice motion are closely correlated with their counterparts of the monthly pressure field in the Arctic Ocean. The mode-one components of these two anomalies alternate between anticyclonic and cyclonic circulation systems. The correlation between Arctic Oscillation indexes and the principal components of the first mode of PCA of the monthly Arctic sea-ice motion is low but statistically significant. C1 Caelum Res Corp, Rockville, MD 20850 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zhao, YH (reprint author), Caelum Res Corp, Rockville, MD 20850 USA. EM yunhe.zhao@gsfc.nasa.gov NR 11 TC 12 Z9 14 U1 0 U2 5 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 2003 SANSEI JIYUGAOKA HAIMU, 5-27-19 OKUSAWA, SETAGAYA-KU, TOKYO, 158-0083, JAPAN SN 0916-8370 J9 J OCEANOGR JI J. Oceanogr. PD JUN PY 2007 VL 63 IS 3 BP 505 EP 515 DI 10.1007/s10872-007-0045-2 PG 11 WC Oceanography SC Oceanography GA 161HF UT WOS:000246004700012 ER PT J AU Smart, MC Whitacre, JF Ratnakumar, BV Amine, K AF Smart, M. C. Whitacre, J. F. Ratnakumar, B. V. Amine, K. TI Electrochemical performance and kinetics of Li1+x(Co1/3Ni1/3Mn1/3)(1-x)O-2 cathodes and graphite anodes in low-temperature electrolytes SO JOURNAL OF POWER SOURCES LA English DT Article DE lithium-ion cells; low-temperature electrolytes; performance; kinetics ID LITHIUM-ION BATTERIES; HIGH-POWER APPLICATIONS; LI(NI1/3CO1/3MN1/3)O-2; CELLS AB Lithium-ion batteries have started replacing the conventional aqueous nickel-based battery systems in space applications, such as planetary landers, rovers, orbiters and satellites. The reasons for such widespread use of these batteries are the savings in mass and volume of the power subsystems, resulting from their high gravimetric and volumetric energy densities, and their ability to operate at extreme temperatures. In our pursuit to further enhance the specific energy as well as low-temperature performance of Li-ion batteries, we have been investigating various layered lithiated metal oxides, e. g., LiCoO2, LiNi0.8Co0.2 and LiNi0.8Co0.15Al0.05O2, as well as different low-temperature electrolytes, including ternary and quaternary carbonate mixtures with various co-solvents. In this paper, we report our recent studies on Li1+x(Co1/3Ni1/3Mn1/3)(1-x)O-2 cathodes, combined with three different low-temperature electrolytes, i.e.: (1) 1.0 M LiPF6 in EC:EMC (20:80), (2) 1.2 M LiPF6 in EC:EMC (20:80) and (3) 1.2 M LiPF6 in EC:EMC (30:70). Electrical performance characteristics were determined in laboratory glass cells at different discharge rates and different temperatures. Further, individual electrode kinetics of both Li1+x(Co1/3Ni1/3Mn1/3)(1-x)O-2 cathodes and MCMB graphite anodes were determined at different temperatures, using do micropolarization, Tafel polarization and electrochemical impedance spectroscopy (EIS). Analysis of these data has led to interesting trends relative to the effects of solvent composition and salt concentration, on the electrical performance and on the kinetics of cathode and anode. Published by Elsevier B.V. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Ratnakumar, BV (reprint author), CALTECH, Jet Prop Lab, M-S 277-207,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ratnakumar.v.bugga@jpl.nasa.gov RI Amine, Khalil/K-9344-2013 NR 11 TC 34 Z9 35 U1 10 U2 67 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 2007 VL 168 IS 2 BP 501 EP 508 DI 10.1016/j.jpowsour.2006.10.106 PG 8 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 176AN UT WOS:000247055200025 ER PT J AU Zhang, ZB Yang, P Kattawar, G Huang, HLA Greenwald, T Li, J Baum, BA Zhou, DK Hu, YX AF Zhang, Zhibo Yang, Ping Kattawar, George Huang, Hung-Lung Allen Greenwald, Thomas Li, Jun Baum, Bryan A. Zhou, Daniel K. Hu, Yongxiang TI A fast infrared radiative transfer model based on the adding-doubling method for hyperspectral remote-sensing applications SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE hyperspectral; radiative transfer; clouds; adding-doubling; remote sensing; fast model ID DISCRETE-ORDINATE-METHOD; EMITTED RADIANCE INTERFEROMETER; MULTIPLE-SCATTERING; CLOUD PROPERTIES; POLARIZED-LIGHT; PART I; AVHRR CHANNELS; CIRRUS CLOUDS; WATER CLOUDS; AIRS AB A fast infrared radiative transfer (RT) model is developed on the basis of the adding-doubling principle, hereafter referred to as FIRTNI-AD, to facilitate the forward RT simulations involved in hyperspectral remote-sensing applications under cloudy-sky conditions. A pre-computed look-up table (LUT) of the bidirectional reflection and transmission functions and emissivities of ice clouds in conjunction with efficient interpolation schemes is used in FIRTM-AD to alleviate the computational burden of the doubling process. FIRTNI-AD is applicable to a variety of cloud conditions, including vertically inhomogeneous or multilayered clouds. In particular, this RT model is suitable for the computation of high-spectral-resolution radiance and brightness temperature (BT) spectra at both the top-of-atmosphere and surface, and thus is useful for satellite and ground-based hyperspectral sensors. In terms of computer CPU time, FIRTM-AD is approximately 100-250 times faster than the well-known discrete-ordinate (DISORT) RT model for the same conditions. The errors of FIRTM-AD, specified as root-mean-square (RMS) BT differences with respect to their DISORT counterparts, are generally smaller than 0.1 K. (c) 2007 Elsevier Ltd. All rights reserved. C1 Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Univ Wisconsin, CIMSS, Madison, WI USA. Univ Wisconsin, Space Sci & Engn Ctr, Madison, WI USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Yang, P (reprint author), Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. EM pyang@ariel.met.tamu.edu RI Zhang, Zhibo/D-1710-2010; Yang, Ping/B-4590-2011; Baum, Bryan/B-7670-2011; Hu, Yongxiang/K-4426-2012; Li, Jun/H-3579-2015 OI Zhang, Zhibo/0000-0001-9491-1654; Baum, Bryan/0000-0002-7193-2767; Li, Jun/0000-0001-5504-9627 NR 65 TC 12 Z9 12 U1 1 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 JUN PY 2007 VL 105 IS 2 BP 243 EP 263 DI 10.1016/j.jqsrt.2007.01.009 PG 21 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 153AD UT WOS:000245403100006 ER PT J AU Cram, TA Persing, J Montgomery, MT Braun, SA AF Cram, Thomas A. Persing, John Montgomery, Michael T. Braun, Scott A. TI A lagrangian trajectory view on transport and mixing processes between the eye, eyewall, and environment using a high-resolution simulation of Hurricane Bonnie (1998) SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID VERTICAL WIND SHEAR; TROPICAL CYCLONE INTENSITY; VORTEX ROSSBY-WAVES; AIR-SEA INTERACTION; PART I; MAXIMUM INTENSITY; VORTICES; FLOW; BUOYANCY; THERMODYNAMICS AB The transport and mixing characteristics of a large sample of air parcels within a mature and vertically sheared hurricane vortex are examined. Data from a high-resolution (2-km horizontal grid spacing) numerical simulation of real-case Hurricane Bonnie (1998) are used to calculate Lagrangian trajectories of air parcels in various subdomains of the hurricane (namely, the eye, eyewall, and near environment) to study the degree of interaction (transport and mixing) between these subdomains. It is found that 1) there is transport and mixing from the low-level eye to the eyewall that carries air possessing relatively high values of equivalent potential temperature (theta(e)), which can enhance the efficiency of the hurricane heat engine; 2) a portion of the low-level inflow of the hurricane bypasses the eyewall to enter the eye, and this air both replaces the mass of the low-level eye and lingers for a sufficient time (order 1 h) to acquire enhanced entropy characteristics through interaction with the ocean beneath the eye; 3) air in the mid- to upper-level eye is exchanged with the eyewall such that more than half the air of the eye is exchanged in 5 h in this case of a sheared hurricane; and 4) that one-fifth of the mass in the eyewall at a height of 5 km has an origin in the mid- to upper-level environment where theta(e) is much less than in the eyewall, which ventilates the ensemble average eyewall theta(e) by about 1 K. Implications of these findings for the problem of hurricane intensity forecasting are briefly discussed. C1 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. NOAA, Hurricane Res Div, Miami, FL 33149 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Montgomery, MT (reprint author), USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. EM mtmontgo@nps.edu NR 63 TC 70 Z9 73 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD JUN PY 2007 VL 64 IS 6 BP 1835 EP 1856 DI 10.1175/JAS3921.1 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 181JR UT WOS:000247433500006 ER PT J AU Matsko, AB Savchenkov, AA Yu, N Maleki, L AF Matsko, Andrey B. Savchenkov, Anatoby A. Yu, Nan Maleki, Lute TI Whispering-gallery-mode resonators as frequency references. I. Fundamental limitations SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID REFERENCE CAVITY; LASER; STABILIZATION; FLUCTUATIONS; OSCILLATOR; MICROWAVE; LEVEL AB We discuss thermodynamic as well as quantum limitations of the stability of resonance frequencies of solid-state whispering-gallery-mode resonators. We show that the relative frequency stability of a millimeter scale resonator can reach one part per 10(-12) per 1 s integration time. (C) 2007 Optical Society of America C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Matsko, AB (reprint author), CALTECH, Jet Propuls Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM andrey.matsko@jpl.nasa.gov RI Matsko, Andrey/A-1272-2007 NR 29 TC 76 Z9 76 U1 2 U2 16 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JUN PY 2007 VL 24 IS 6 BP 1324 EP 1335 DI 10.1364/JOSAB.24.001324 PG 12 WC Optics SC Optics GA 173IU UT WOS:000246867500012 ER PT J AU Fiske, TG Silverstein, LD Hodgson, S Watson, AB AF Fiske, Thomas G. Silverstein, Louis D. Hodgson, Sue Watson, Andrew B. TI Visual quality of high-contrast projection screens. Part I: Visibility of screen-based artifacts and noise SO JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY LA English DT Article DE projection screens; visual quality; noise modulation; graininess; speckle ID DISPLAYS; SPECKLE AB The investigation of visual-quality issues for high-contrast projection screens such as those used for avionics projection displays and other applications requiring a high level of ambient light rejection will be described. Visibility of artifacts and noise generated by the optical and structural properties of a variety of high-contrast projection screens was characterized by both empirical, subjective image quality evaluations and a suite of objective screen-quality metrics. At least two of these metrics were found to provide very good correlation with the subjective assessment. These metrics are applicable to any display system where spatial-noise artifacts are an issue, such as with direct-view AMLCDs with anti-glare treatments. C1 Rockwell Collins Display Syst, San Jose, CA 95134 USA. VCD Sci Inc, Scottsdale, AZ USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Fiske, TG (reprint author), Rockwell Collins Display Syst, 2701 Orchard Pkwy,MS 040, San Jose, CA 95134 USA. EM tgfiske@rockwellcollins.com NR 18 TC 2 Z9 2 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 2007 VL 15 IS 6 BP 409 EP 419 DI 10.1889/1.2749327 PG 11 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA 178VH UT WOS:000247247700010 ER PT J AU Thomas, RE Lindeberg, M Harris, PM Rice, SD AF Thomas, Robert E. Lindeberg, Mandy Harris, Patricia M. Rice, Stanley D. TI Induction of DNA strand breaks in the mussel (Mytilus trossulus) and clam (Protothaca staminea) following chronic field exposure to polycyclic aromatic hydrocarbons from the Exxon Valdez spill SO MARINE POLLUTION BULLETIN LA English DT Article DE Exxon valdez oil spill; passive samplers; comet; DNA damage ID PRINCE-WILLIAM-SOUND; DIGESTIVE GLAND-CELLS; OIL-SPILL; COMET ASSAY; CRUDE-OIL; DAMAGE; ALASKA; SEDIMENTS; ECOSYSTEM; RECOVERY AB In 2002, 13 years after the Exxon Valdez spill, mussels and clams were examined for lingering oil exposure and damage. Known oil patches were sampled at four locations, and compared to nearby reference areas (same bay), and were also compared to "hot reference" sites to verify the methods used (Cordova harbor and fresh diesel spill at Port Chalmers). Passive samplers deployed for a month at the sites, along with tissue samples, confirmed that the oiled sites were oiled (fingerprinting back to Exxon Valdez oil) and that reference sites were clean. The highest PAH loads were detected in sub-surface interstitial waters at oiled sites. Exposure at the surface was generally low level, and probably intermittent. DNA damage was assessed in blood cells using sensitive comet analyses. DNA strand breakage was detected in both mussels and clams, with the highest level of damage detected at "hot reference" sites of Cordova harbor and Port Chalmers. Bioavailability and DNA damage at the oiled sties was low, indicating there has been substantial progress in recovery from the spill 13 years before, yet low level bioavailability and damage were still detectable. Published by Elsevier Ltd. C1 NOAA, Natl Marine Fisheries Serv, Juneau, AK 99801 USA. Calif State Univ Los Angeles, Dept Biol Sci, Chico, CA 95929 USA. RP Rice, SD (reprint author), NOAA, Natl Marine Fisheries Serv, 11305 Glacier Highway, Juneau, AK 99801 USA. EM Jeep.Rice@noaa.gov NR 20 TC 22 Z9 26 U1 1 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD JUN PY 2007 VL 54 IS 6 BP 726 EP 732 DI 10.1016/j.marpolbul.2007.01.009 PG 7 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 185UT UT WOS:000247736600020 PM 17328928 ER PT J AU Bell, MS AF Bell, M. S. TI Experimental shock decomposition of siderite and the origin of magnetite in Martian meteorite ALH 84001 SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID ALLAN HILLS 84001; TRANSMISSION ELECTRON-MICROSCOPY; THERMAL-DECOMPOSITION; MINERAL NOMENCLATURE; ALH84001; CARBONATE; ALLAN-HILLS-84001; STABILITY; MAGNETOFOSSILS; TEMPERATURES AB Shock recovery experiments to determine whether magnetite could be produced by the decomposition of iron-carbonate were initiated. Naturally occurring siderite was first characterized by a variety of techniques to be sure that the starting material did not contain detectable magnetite. Samples were shocked in tungsten-alloy holders (W=90%, Ni=6%, Cu=4%) to further ensure that any iron phases in the shock products were contributed by the siderite rather than the sample holder. Each sample was shocked to a specific pressure between 30 to 49 GPa. Transformation of siderite to magnetite as characterized by TEM was found in the 49 GPa shock experiment. Compositions of most magnetites are >50% Fe+2 in the octahedral site of the inverse spinel structure. Magnetites produced in shock experiments display the same range of sizes (similar to 50-100 nm), compositions (100% magnetite to 80% magnetite-20% magnesioferrite), and morphologies (equant, elongated, euhedral to subhedral) as magnetites synthesized by Golden et al. (2001) and as the magnetites in, Martian meteorite Allan Hills (ALH) 84001. Fritz et al. (2005) previously concluded that ALH 84001 experienced similar to 32 GPa pressure and a resultant thermal pulse of similar to 100-110 degrees C. However, ALH 84001 contains evidence of local temperature excursions high enough to melt feldspar, pyroxene, and a silica-rich phase. This 49 GPa experiment demonstrates that magnetite can be produced by the shock decomposition of siderite as a result of local heating to >470 degrees C. Therefore, magnetite in the rims of carbonates in Martian meteorite ALH 84001 could be a product of shock devolatilization of siderite as well. C1 Univ Houston, Dept Geosci, Houston, TX 77204 USA. Johnson Space Ctr, Jacobs Engn, Houston, TX 77058 USA. RP Bell, MS (reprint author), Univ Houston, Dept Geosci, Houston, TX 77204 USA. EM mary.sue.bell1@jsc.nasa.gov NR 60 TC 10 Z9 11 U1 0 U2 9 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUN PY 2007 VL 42 IS 6 BP 935 EP 949 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 182CP UT WOS:000247483000003 ER PT J AU Rubin, RH Simpson, JP Colgan, SWJ Dufour, RJ Ray, KL Erickson, EF Haas, MR Pauldrach, AWA Citron, RI AF Rubin, Robert H. Simpson, Janet P. Colgan, Sean W. J. Dufour, Reginald J. Ray, Katherine L. Erickson, Edwin F. Haas, Michael R. Pauldrach, Adalbert W. A. Citron, Robert I. TI Spitzer observations of M83 and the hot star, HII region connection SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : atmospheres; ISM : abundances; HII regions; galaxies : individual : M83 ID H-II REGIONS; FINE-STRUCTURE LINES; ABUNDANCE GRADIENTS; CHEMICAL EVOLUTION; INFRARED SPECTROGRAPH; IONIZATION STRUCTURE; STELLAR POPULATIONS; HELIUM ABUNDANCE; SPACE-TELESCOPE; MASSIVE STARS AB We have undertaken a programme to observe emission lines of [S IV] 10.51, [Ne II] 12.81, [Ne III] 15.56, and [S III] 18.71 m in a number of extragalactic H II regions with the Spitzer Space Telescope. Here we report our results for the nearly face-on spiral galaxy M83. A subsequent paper will present our data and analysis for another substantially face-on spiral galaxy M33. The nebulae selected cover a wide range of galactocentric radii (RG). The observations were made with the infrared spectrograph in the short wavelength, high dispersion configuration. The above set of four lines is observed cospatially, thus permitting a reliable comparison of the fluxes. From the measured fluxes, we determine the ionic abundance ratios including Ne++/ Ne+, S3+/ S++ and S++/ Ne+ and find that there is a correlation of increasingly higher ionization with larger RG. By sampling the dominant ionization states of Ne and S for HII regions, we can approximate the Ne/S ratio by (Ne+ + Ne++)/(S++ + S3+). Our findings of ratios that significantly exceed the benchmark Orion Nebula value, as well as a decrease in this ratio with increasing RG, are more likely due to other effects than a true gradient in Ne/ S. Two effects that will tend to lower these high estimates and to flatten the gradient are first, the method does not account for the presence of S+ and second, S but not Ne is incorporated into grains. Both Ne and S are primary elements produced in alpha-chain reactions, following C and O burning in stars, making their yields depend very little on the stellar metallicity. Thus, it is expected that Ne/ S remains relatively constant throughout a galaxy. We stress that this type of observation and method of analysis does have the potential for accurate measurements of Ne/ S, particularly for HII regions that have lower metallicity and higher ionization than those here, such as those in M33. Our observations may also be used to test the predicted ionizing spectral energy distribution ( SED) of various stellar atmosphere models. We compare the ratio of fractional ionizations < Ne++>/< S++> and < Ne++ >/< S3+> versus < S3+>/< S++> with predictions made from our photoionization models using several of the state-of-the-art stellar atmosphere model grids. The overall best fit appears to be the nebular models using the supergiant stellar atmosphere models of Pauldrach, Hoffmann& Lennon and Sternberg, Hoffmann& Pauldrach. This result is not sensitive to the electron density and temperature range expected for these M83 nebulae. Considerable computational effort has gone into the comparison between data and models, although not all parameter studies have yet been performed on an ultimate level (e. g. in the present paper the stellar atmosphere model abundances have been fixed to solar values). A future paper, with the benefit of more observational data, will continue these studies to further discriminate how the ionic ratios depend on the SED and the other nebular parameters. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Orion Enterprises, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94043 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Univ Munich, D-81679 Munich, Germany. RP Rubin, RH (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM rubin@cygnus.arc.nasa.gov; simpson@cygnus.arc.nasa.gov RI Colgan, Sean/M-4742-2014 NR 53 TC 20 Z9 20 U1 0 U2 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUN 1 PY 2007 VL 377 IS 4 BP 1407 EP 1418 DI 10.1111/j.1365-2966.2007.11714.x PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 172IS UT WOS:000246798200002 ER PT J AU De Pasquale, M Oates, SR Page, MJ Burrows, DN Blustin, AJ Zane, S Mason, KO Roming, PWA Palmer, D Gehrels, N Zhang, B AF De Pasquale, Massimiliano Oates, S. R. Page, M. J. Burrows, D. N. Blustin, A. J. Zane, S. Mason, K. O. Roming, P. W. A. Palmer, D. Gehrels, N. Zhang, B. TI Early afterglow detection in the Swift observations of GRB 050801 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE gamma-rays : bursts ID GAMMA-RAY BURSTS; CONTINUOUS ENERGY INJECTION; TELESCOPE; EMISSION; LIGHT; SIGNATURE; RESERVOIR; REDSHIFT; BEPPOSAX; PROMPT AB We present results of Swift optical, ultraviolet (UV) and X-ray observations of the afterglow of GRB 050801. The source is visible over the full optical, UV and X-ray energy range of the Swift Ultraviolet and Optical Telescope and X- ray telescope instruments. Both optical and X- ray light curves exhibit a broad plateau (Delta t/t similar to 1) during the first few hundred seconds after the gamma-ray event. We investigate the multiwavelength spectral and timing properties of the afterglow, and we suggest that the behaviour at early times is compatible with an energy injection by a newly born magnetar with a period of a few tenths of a millisecond, which keeps the forward shock refreshed over this short interval by irradiation. Reverse shock emission is not observed. Its suppression might be due to GRB ejecta being permeated by high magnetic fields, as expected for outflows powered by a magnetar. Finally, the multiwavelength study allows a determination of the burst redshift, z = 1.56. C1 UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. RP De Pasquale, M (reprint author), UCL, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England. EM mdp@mssl.ucl.ac.uk RI Gehrels, Neil/D-2971-2012 NR 38 TC 26 Z9 26 U1 0 U2 1 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 1 PY 2007 VL 377 IS 4 BP 1638 EP 1646 DI 10.1111/j.1365-2966.2007.11724.x PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 172IS UT WOS:000246798200025 ER PT J AU Jacob, SD Koblinsky, CJ AF Jacob, S. Daniel Koblinsky, Chester J. TI Effects of precipitation on the upper-ocean response to a hurricane SO MONTHLY WEATHER REVIEW LA English DT Article ID MIXED-LAYER RESPONSE; TROPICAL CYCLONES; VERTICAL DIFFUSIVITIES; NUMERICAL SIMULATIONS; CLOSURE-MODEL; TURBULENCE; MOMENTUM; RAINFALL; HEAT AB The effect of precipitation on the upper-ocean response during a tropical cyclone passage is investigated using a numerical model in this paper. For realistic wind forcing and empirical rain rates based on satellite climatology, numerical simulations are performed with and without precipitation forcing to delineate the effects of freshwater forcing on the upper-ocean heat and salt budgets. Additionally, the performance of five mixing parameterizations is also examined for the two forcing conditions to understand the sensitivity of simulated ocean response. Overall, results from 15 numerical experiments are analyzed to quantify the precipitation effects on the oceanic mixed layer and the upper ocean. Simulated fields for the same mixing scheme with and without precipitation indicate a decrease in the upper-ocean cooling of about 0.2-0.5 degrees C. This is mainly due to reduced mixing of colder water from below induced by the increased stability of the added freshwater. The cooler rainwater contributes a maximum of approximately 10% to the total surface heat loss from the ocean. The rate of freshening due to precipitation exceeds the rate of mixing of the more saline water from below, leading to a change in sign of the mixed layer salinity response. As seen in earlier studies, large uncertainty exists in the simulated upper-ocean response due to the choice of mixing parameterization. Although the nature of simulated response remains similar for all the mixing schemes, the magnitude of freshening and cooling varies by as much as 0.5 psu and 1 degrees C between the schemes to the right of the storm track. While changes in the mixed layer and in the top 100 m of heat and salt budgets are strongly influenced by the choice of mixing scheme, integrated budgets in the top 200 m are seen to be affected more by advection and surface fluxes. However, since the estimated surface fluxes depend upon the simulated sea surface temperature, the choice of mixing scheme is crucial for realistic coupled predictive models. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Climate Off, Silver Spring, MD USA. RP Jacob, SD (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, 5523 Res Pk Dr,Suite 320, Baltimore, MD 21228 USA. EM jacob@umbc.edu NR 28 TC 12 Z9 12 U1 1 U2 8 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 2007 VL 135 IS 6 BP 2207 EP 2225 DI 10.1175/MWR3366.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 183FZ UT WOS:000247559400010 ER PT J AU Sun, CJ Rienecker, MM Rosati, A Harrison, M Wittenberg, A Keppenne, CL Jacob, JP Kovach, RM AF Sun, Chaojiao Rienecker, Michele M. Rosati, Anthony Harrison, Matthew Wittenberg, Andrew Keppenne, Christian L. Jacob, Jossy P. Kovach, Robin M. TI Comparison and sensitivity of ODASI ocean analyses in the Tropical Pacific SO MONTHLY WEATHER REVIEW LA English DT Article ID GENERAL-CIRCULATION MODEL; DATA ASSIMILATION SYSTEM; ENSEMBLE KALMAN FILTER; EQUATORIAL PACIFIC; EL-NINO; SURFACE CURRENTS; SEASONAL FORECASTS; INITIAL CONDITIONS; ERROR COVARIANCE; ENSO PREDICTION AB Two global ocean analyses from 1993 to 2001 have been generated by the Global Modeling and Assimilation Office (GMAO) and Geophysical Fluid Dynamics Laboratory (GFDL), as part of the Ocean Data Assimilation for Seasonal-to-Interannual Prediction (ODASI) consortium efforts. The ocean general circulation models (OGCM) and assimilation methods in the analyses are different, but the forcing and observations are the same as designed for ODASI experiments. Global expendable bathythermograph and Tropical Atmosphere Ocean (TAO) temperature profile observations are assimilated. The GMAO analysis also assimilates synthetic salinity profiles based on climatological T-S relationships from observations (denoted "TS scheme"). The quality of the two ocean analyses in the tropical Pacific is examined here. Questions such as the following are addressed: How do different assimilation methods impact the analyses, including ancillary fields such as salinity and currents? Is there a significant difference in interpretation of the variability from different analyses? How does the treatment of salinity impact the analyses? Both GMAO and GFDL analyses reproduce the time mean and variability of the temperature field compared with assimilated TAO temperature data, taking into account the natural variability and representation errors of the assimilated temperature observations. Surface zonal currents at 15 m from the two analyses generally agree with observed climatology. Zonal current profiles from the analyses capture the intensity and variability of the Equatorial Undercurrent (EUC) displayed in the independent acoustic Doppler current profiler data at three TAO moorings across the equatorial Pacific basin. Compared with independent data from TAO servicing cruises, the results show that 1) temperature errors are reduced below the thermocline in both analyses; 2) salinity errors are considerably reduced below the thermocline in the GMAO analysis; and 3) errors in zonal currents from both analyses are comparable. To discern the impact of the forcing and salinity treatment, a sensitivity study is undertaken with the GMAO assimilation system. Additional analyses are produced with a different forcing dataset, and another scheme to modify the salinity field is tested. This second scheme updates salinity at the time of temperature assimilation based on model T-S relationships (denoted "T scheme"). The results show that both assimilated field (i.e., temperature) and fields that are not directly observed (i.e., salinity and currents) are impacted. Forcing appears to have more impact near the surface (above the core of the EUC), while the salinity treatment is more important below the surface that is directly influenced by forcing. Overall, the TS scheme is more effective than the T scheme in correcting model bias in salinity and improving the current structure. Zonal currents from the GMAO control run where no data are assimilated are as good as the best analysis. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Sci Applicat Int Corp, Beltsville, MD USA. RP Sun, CJ (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM chaojiao.sun@gsfc.nasa.gov RI Sun, Chaojiao/A-9569-2011; Wittenberg, Andrew/G-9619-2013 OI Sun, Chaojiao/0000-0002-7030-0485; Wittenberg, Andrew/0000-0003-1680-8963 NR 53 TC 14 Z9 14 U1 0 U2 0 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 2007 VL 135 IS 6 BP 2242 EP 2264 DI 10.1175/MWR3405.1 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 183FZ UT WOS:000247559400012 ER PT J AU Carrier, M Zou, X Lapenta, WM AF Carrier, M. Zou, X. Lapenta, William M. TI Identifying cloud-uncontaminated AIRS spectra from cloudy FOV based on cloud-top pressure and weighting functions SO MONTHLY WEATHER REVIEW LA English DT Article ID RADIATIVE-TRANSFER; MODEL AB An effort is made to increase the number of Advanced Infrared Sounder (AIRS) cloud-uncontaminated infrared data for regional mesoscale data assimilation and short-term quantitative precipitation forecast (QPF) applications. The cloud-top pressure from Moderate Resolution Imaging Spectroradiometer (MODIS) is utilized in combination with weighting functions (WFs) to develop a channel-based cloudy-data-removal algorithm. This algorithm identifies "clear channels" for which the brightness temperature (BT) values are not cloud contaminated. A channel-dependent cutoff pressure (COP) level is first determined based on the structure of the WF of each channel. It is usually below the maximum WF level. If the cloud top (as identified by a MODIS cloud mask) is above (below) the COP level of a channel, this channel is then deemed cloudy (clear) and removed (retained). Using this algorithm, a sizable increase of cloud-uncontaminated AIRS data can be obtained. There are more usable domain points for those channels with higher COP levels. A case study is conducted. It is shown that instead of having less than 20% AIRS clear-sky observations, the algorithm finds 80% (58%) of the AIRS pixels on which there are channels whose COP levels are at or above 300 hPa (500 hPa) and the BT data in these channels at these pixels are cloud uncontaminated. Such a significant increase of the usable AIRS cloud-uncontaminated data points is especially useful for regional mesoscale data assimilation and short-term QPF applications. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. NASA, George C Marshall Space Flight Ctr, Global Hydrol & Climate Ctr, Huntsville, AL 35812 USA. RP Carrier, M (reprint author), Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. EM mcarrier@met.fsu.edu NR 18 TC 6 Z9 7 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 2007 VL 135 IS 6 BP 2278 EP 2294 DI 10.1175/MWR3384.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 183FZ UT WOS:000247559400014 ER PT J AU Lin, YJ Moore, JT Fishman, J AF Lin, Yeong-Jer Moore, James T. Fishman, Jack TI A brief summary of Dr. G. V. Rao's research interests SO NATURAL HAZARDS LA English DT Biographical-Item DE tropical cyclone; monsoon; low-level jet; peninsular Florida; mesoscale; mesoscale-model; mesocyclone; tornado AB A brief summary of Dr. G. V. Rao's research interests is presented. Many of his earlier studies were in conjunction with the summer Monsoon Experiment of 1979 (MONEX-79). These included: 1) the structure of the Somali jet based on aerial observations; 2) sea-level air trajectories over the equatorial Indian Ocean; 3) structural features of the east African low-level flow; 4) effects of Indian Ocean surface temperature anomaly patterns on the summer monsoon circulations; 5) structures of the monsoon low-level flow over the Arabian Sea; 6) characteristics and momentum-flux budgets of the Arabian Sea convective bands; and 7) evaporation and precipitation over the Arabian Sea during the monsoon seasons. Dr. Rao's research efforts in recent years had focused on case studies of mesocyclones spawned by tropical cyclones (TCs) in Florida using Doppler radar data and a mesoscale numerical model. These included: 1) research on tornadic mesocyclones spawned by TC Earl in 1998; 2) documentation of subtle differences between tornadic and non-tornadic mesocyclones in TC Floyd in 1999; and 3) numerical simulation of the tornadic environment observed in peninsular Florida during TC Earl in 1998. Preliminary findings show that the supercells' cold pools interacted with an existing boundary resulting in increased baroclinicity and horizontal vorticity, and a maximization of the tornado production potential by the updrafts. The model successfully simulated the mesoscale features of the mesocyclones and the tornadic environment observed during TC Earl. A 24 h simulation of accumulated rainfall within the inner domain agreed well with the observed precipitation pattern over the region. C1 St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA. NASA, Langley Res Ctr, Sci Directorate, Chem & Dynam Branch, Hampton, VA 23681 USA. RP Lin, YJ (reprint author), St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA. EM yeongjlin@sbcglobal.net; moore@cas.slu.edu; jack.fishman@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0921-030X J9 NAT HAZARDS JI Nat. Hazards PD JUN PY 2007 VL 41 IS 3 BP 381 EP 386 DI 10.1007/s11069-006-9059-0 PG 6 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA 169NJ UT WOS:000246598600002 ER PT J AU Sisti, M AF Sisti, M. CA MARE collaboration TI MARE: Re-187 beta spectrum analysis with bolometric techniques SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Proceedings Paper CT Neutrino Oscillation Workshop (NOW 2006) CY SEP 09-15, 2006 CL Otranto, ITALY SP INFN, Dept Phys, MUR, Univ Bari & Lecce, European Network Theoret Astroparticle Phys AB A large worldwide collaboration is growing around the project of Microcalorimeter Arrays for a Rhenium Experiment (MARE) for a direct calorimetric measurement of the neutrino mass with a sensitivity of about 0.2 eV. Many groups are joining their experiences and technical expertises in a common effort towards this challenging experiment which will use the most recent and advanced developments of the thermal detection technique. The expected impact of MARE as a complement of the KATRIN experiment will also be discussed. C1 Univ Milan, Dipartimento Fis, Ist Nazl Fis Nucl, Sez Milano Bicocca, Milan, Italy. Univ Genoa, Ist Nazl Fis Nucl, Genoa, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Heidelberg, Kirkhhof Inst Phys, Heidelberg, Germany. Univ Milano Bicocca, INFN Milano Bicocca, Milan, Italy. NIST, Boulder, CO USA. IRST, ITC, I-38050 Trento, Italy. Ist Nazl Fis Nucl, Padua, Italy. PTB, Berlin, Germany. Univ Miami, Miami, FL 33152 USA. Univ Roma La Sapienza, INFN Roma 1, Rome, Italy. SISSA, I-34014 Trieste, Italy. Univ Wisconsin, Madison, WI USA. Univ Florida, Gainesville, FL 32611 USA. Univ Maryland, College Pk, MD 20742 USA. RP Sisti, M (reprint author), Univ Milan, Dipartimento Fis, Ist Nazl Fis Nucl, Sez Milano Bicocca, Via Celoria 16, Milan, Italy. RI Sisti, Monica/B-7550-2013 OI Sisti, Monica/0000-0003-2517-1909 NR 5 TC 1 Z9 1 U1 1 U2 1 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 2007 VL 168 BP 48 EP 50 DI 10.1016/j.nuclphysbps.2007.02.004 PG 3 WC Physics, Particles & Fields SC Physics GA 182WY UT WOS:000247535900011 ER PT J AU Mouroulis, P Sellar, RG Wilson, DW Shea, JJ Green, RO AF Mouroulis, Pantazis Sellar, R. Glenn Wilson, Daniel W. Shea, James J. Green, Robert O. TI Optical design of a compact imaging spectrometer for planetary mineralogy SO OPTICAL ENGINEERING LA English DT Article DE spectrometers; optical design; space optics; imaging spectroscopy ID SPECTROSCOPY AB We present the design of a compact, wide-angle pushbroom imaging spectrometer suitable for exploration of solar system bodies from low orbit. The spectrometer is based on a single detector array with a broadband response that covers the range 400 to 3000 nm and provides a spectral sampling of 10 nm. The telescope has a 24-deg field of view with 600 spatially resolved elements (detector pixels). A specially designed convex diffraction grating permits optimization of the signal-to-noise ratio through the entire spectral band. Tolerances and design parameters permit the achievement of high uniformity of response through field and wavelength. The spectrometer performance is evaluated in terms of predicted spectral and spatial response functions and from the point of view of minimizing their variation through field and wavelength. The design serves as an example for illustrating the design principles specific to this type of system. (C) 2007 Society of Photo-Optical Instrumentation Engineers. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Alliant Techsyst, ATK, Pasadena, CA 91107 USA. RP Mouroulis, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Pantazis.mouroulis@jpl.nasa.gov NR 14 TC 23 Z9 34 U1 2 U2 8 PU SPIE-SOCIETY PHOTOPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD JUN PY 2007 VL 46 IS 6 AR 063001 DI 10.1117/1.2749499 PG 9 WC Optics SC Optics GA 186XX UT WOS:000247813000004 ER PT J AU Yang, P Evans, J Cole, M Marley, S Alameh, N Bambacus, M AF Yang, Phil Evans, John Cole, Marge Marley, Steve Alameh, Nadine Bambacus, Myra TI The emerging concepts and applications of the spatial web portal SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID GIS AB Geospatial metadata, data, and services have been widely collected, developed and deployed in recent years. This flourishing of geospatial resources also added to the problem of geospatial heterogeneity. Interoperability research and implementation are needed for advancement in potential solutions to integrate and interoperate these widely dispersed geospatial resources. We propose the Spatial Web Portal architecture to integrate and interoperate geospatial resources. The architecture leverages web-based computing, spatial web services, and web fragments to integrate geospatial metadata, data, analysis, and presentation, through distributed portlets: (1) Spatial web services ore adopted to interoperate geospatial components. (2) Web portals are adopted to integrate web pages from web fragments generated by portlets. (3) W3C recommendations are adopted to provide access to remote portlets delegating geospatial components. (4) Java community specifications are adopted to facilitate the development and distribution of portlets. NASA's Earth Science Gateway (ESG) is designed and developed as an example to test the proposed architecture in sharing earth observations, simulations, and other geospatial resources. The proposed architecture and example system provide (a) a tested mechanism for interoperating geospatial resources at different levels, (b) an environment to test new interoperable concepts, and (c) a platform to support heterogeneous-geospatial-resource based applications of national and global significance, such as the Global Earth Observing System of Systems (GEOSs) applications. C1 NASA, Goddard Space Flight Ctr, Geosci Interoperabil Off, Greenbelt, MD 20771 USA. George Mason Univ, Joint Ctr Intelligent Spatial Comp, Coll Sci, Fairfax, VA 22030 USA. Global Sci & Technol Inc, Greenbelt, MD 20770 USA. Mobilaps LLC, Silver Spring, MD 20910 USA. RP Yang, P (reprint author), NASA, Goddard Space Flight Ctr, Geosci Interoperabil Off, Greenbelt, MD 20771 USA. EM cyang3@gmu.edu RI Yang, Chaowei/A-9881-2017; OI Yang, Chaowei/0000-0001-7768-4066 NR 38 TC 22 Z9 22 U1 0 U2 3 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 JUN PY 2007 VL 73 IS 6 BP 691 EP 698 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 173KM UT WOS:000246871900010 ER PT J AU Bhatia, AK Drachman, RJ AF Bhatia, A. K. Drachman, Richard J. TI Polarizabilities of the Ps negative ion SO PHYSICAL REVIEW A LA English DT Article ID POSITRONIUM; PHOTODETACHMENT; LITHIUM AB We have calculated polarizabilities (alpha(1), beta(1), gamma(1), alpha(2), beta(2), and gamma(2)) of Ps(-) by the pseudostate method. These parameters can be used to calculate Rydberg states of Ps(-) in the presence of an external electron with high quantum numbers N and L. They are also of importance in a system containing Ps(-) bound to a proton [PsH] and also Rydberg states of Ps(2). C1 NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Greenbelt, MD 20771 USA. RP Bhatia, AK (reprint author), NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Code 661, Greenbelt, MD 20771 USA. NR 11 TC 11 Z9 11 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 JUN PY 2007 VL 75 IS 6 AR 062510 DI 10.1103/PhysRevA.75.062510 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 184EQ UT WOS:000247624300086 ER PT J AU Baker, JG McWilliams, ST van Meter, JR Centrella, J Choi, DI Kelly, BJ Koppitz, M AF Baker, John G. McWilliams, Sean T. van Meter, James R. Centrella, Joan Choi, Dae-Il Kelly, Bernard J. Koppitz, Michael TI Binary black hole late inspiral: Simulations for gravitational wave observations SO PHYSICAL REVIEW D LA English DT Article ID ADAPTIVE MESH REFINEMENT; HARMONIC DECOMPOSITION; NUMERICAL RELATIVITY; EVOLUTION; MERGER; COALESCENCES; EQUATION; SCHEME; SIGNAL AB Coalescing binary black hole mergers are expected to be the strongest gravitational wave sources for ground-based interferometers, such as the LIGO, VIRGO, and GEO600, as well as the space-based interferometer LISA. Until recently it has been impossible to reliably derive the predictions of general relativity for the final merger stage, which takes place in the strong-field regime. Recent progress in numerical relativity simulations is, however, revolutionizing our understanding of these systems. We examine here the specific case of merging equal-mass Schwarzschild black holes in detail, presenting new simulations in which the black holes start in the late-inspiral stage on orbits with very low eccentricity and evolve for similar to 1200M through similar to 7 orbits before merging. We study the accuracy and consistency of our simulations and the resulting gravitational waveforms, which encompass similar to 14 cycle before merger, and highlight the importance of using frequency (rather than time) to set the physical reference when comparing models. Matching our results to post-Newtonian (PN) calculations for the earlier parts of the inspiral provides a combined waveform with less than one cycle of accumulated phase error through the entire coalescence. Using this waveform, we calculate signal-to-noise ratios (SNRs) for iLIGO, adLIGO, and LISA, highlighting the contributions from the late-inspiral and merger-ringdown parts of the waveform, which can now be simulated numerically. Contour plots of SNR as a function of z and M show that adLIGO can achieve SNR greater than or similar to 10 for some intermediate mass binary black holes (IMBBHs) out to z similar to 1, and that LISA can see massive binary black holes (MBBHs) in the range 3x10(4)less than or similar to M/M less than or similar to 10(7) at SNR > 100 out to the earliest epochs of structure formation at z > 15. C1 NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Maryland Baltimore Cty, Ctr Space Sci & Technol, Dept Phys, Baltimore, MD 21250 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. Korea Inst Sci & Technol Informat, Taejon 305806, South Korea. Albert Einstein Inst, D-14471 Golm, Germany. RP Baker, JG (reprint author), NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. RI van meter, james/E-7893-2011; Kelly, Bernard/G-7371-2011; OI Kelly, Bernard/0000-0002-3326-4454 NR 57 TC 78 Z9 78 U1 0 U2 1 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 2007 VL 75 IS 12 AR 124024 DI 10.1103/PhysRevD.75.124024 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 184FB UT WOS:000247625400058 ER PT J AU Murphy, TW Nordtvedt, K Turyshev, SG AF Murphy, T. W., Jr. Nordtvedt, K. Turyshev, S. G. TI Gravitomagnetic influence on gyroscopes and on the lunar orbit - Reply SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material ID GRAVITY C1 Univ Calif San Diego, La Jolla, CA 92093 USA. NW Anal, Bozeman, MT 59715 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Murphy, TW (reprint author), Univ Calif San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA. EM tmurphy@physics.ucsd.edu NR 8 TC 10 Z9 10 U1 0 U2 1 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 1 PY 2007 VL 98 IS 22 AR 229002 DI 10.1103/PhysRevLett.98.229002 PG 1 WC Physics, Multidisciplinary SC Physics GA 173ZD UT WOS:000246910100066 ER PT J AU Selle, LC Bellan, J AF Selle, L. C. Bellan, J. TI Characteristics of transitional multicomponent gaseous and drop-laden mixing layers from direct numerical simulation: Composition effects SO PHYSICS OF FLUIDS LA English DT Article ID MACH-NUMBER TURBULENCE; LARGE-EDDY SIMULATION; CONTINUOUS THERMODYNAMICS; EVAPORATING DROPS; FLOW SIMULATIONS; VAPORIZATION; MIXTURES; MODEL; COMPONENTS; DISPERSION AB Transitional states are obtained by exercising a model of multicomponent-liquid (MC-liquid) drop evaporation in a three-dimensional mixing layer at larger Reynolds numbers, Re, than in a previous study. The gas phase is followed in an Eulerian frame and the multitude of drops is described in a Lagrangian frame. Complete dynamic and thermodynamic coupling between phases is included. The liquid composition, initially specified as a single-Gamma (SG) probability distribution function (PDF) depending on the molar mass, is allowed to evolve into a linear combination of two SGPDFs, called the double-Gamma PDF (DGPDF). The compositions of liquid and vapor emanating from the drops are calculated through four moments of their PDFs, which are drop-specific and location-specific, respectively. The mixing layer is initially excited to promote the double pairing of its four initial spanwise vortices, resulting into an ultimate vortex in which small scales proliferate. Simulations are performed for four liquids of different compositions, and the effects of the initial mass loading and initial free-stream gas temperature are explored. For reference, simulations are also performed for gaseous multicomponent mixing layers for which the effect of Re is investigated in the direct-numerical-simulation-accessible regime. The results encompass examination of the global layer characteristics, flow visualizations, and homogeneous-plane statistics at transition. Comparisons are performed with previous pretransitional MC-liquid simulations and with transitional single-component (SC) liquid-drop-laden mixing layer studies. Contrasting to pretransitional MC flows, the vorticity and drop organization depend on the initial gas temperature, this being due to drop/turbulence coupling. The vapor-composition mean molar mass and standard deviation distributions strongly correlate with the initial liquid-composition PDF. Unlike in pretransitional situations, regions of large composition standard deviation no longer necessarily coincide with those of large mean molar mass. The rotational and composition characteristics are all liquid-specific and the variation among liquids is amplified with increasing free-stream gas temperature. The classical energy cascade is found to be of similar strength, but the smallest scales contain orders of magnitude less energy than SC flows, which is confirmed by the larger viscous dissipation for MC flows. The kinetic energy and dissipation are liquid-specific and the variation among liquids is amplified with increasing free-stream gas temperature. The gas composition, of which the first four moments are calculated, is shown to be close to, but distinct from, a SGPDF. Eulerian and Lagrangian statistics of gas-phase quantities show that the different observation framework may affect the perception of the flow. (c) 2007 American Institute of Physics. C1 CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bellan, J (reprint author), CALTECH, Pasadena, CA 91125 USA. EM josette.bellan@jpl.nasa.gov RI Selle, Laurent/I-6369-2013 OI Selle, Laurent/0000-0002-5997-3646 NR 42 TC 5 Z9 5 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD JUN PY 2007 VL 19 IS 6 AR 063301 DI 10.1063/1.2734997 PG 33 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 184FG UT WOS:000247625900008 ER PT J AU Soller, BR Hagan, RD Shear, M Walz, JM Landry, M Anunciacion, D Orquiola, A Heard, SO AF Soller, Babs R. Hagan, R. Donald Shear, Michael Walz, J. Matthias Landry, Michelle Anunciacion, Dulce Orquiola, Alan Heard, Stephen O. TI Comparison of intramuscular and venous blood pH, PCO2 and PO2 during rhythmic handgrip exercise SO PHYSIOLOGICAL MEASUREMENT LA English DT Article DE tissue oxygenation; metabolism; acid-base; fiber optic sensors ID HUMAN SKELETAL-MUSCLE; HEMORRHAGIC-SHOCK; OXYGEN; DISSOCIATION; TRANSPORT; ACIDOSIS; SENSORS; LACTATE; PO-2; CO2 AB Oxygen and acid-base status during exercise is well established for the lungs, large arteries and veins. However, values for these parameters in exercising muscle are less frequently reported. In this study we examined the relationship between intramuscular PO2, pH, PCO2 and the comparable venous values during rhythmic isometric handgrip exercise at target levels of 15%, 30% and 45% of maximum voluntary contraction (MVC). A small fiber optic sensor was inserted into the flexor digitorum profundus (FDP) muscle for continuous measurement of intramuscular (IM) PO2, pH and PCO2. Venous blood samples were taken from the forearm every minute during each exercise bout. IM pH and PCO2 were similar to their venous counterparts at baseline, but the difference between IM and venous values increased when exercise exceeded 30% MVC. During exercise at 15% MVC and greater, venous PO2 declined from 40 to 21 Torr (similar or equal to 5.3 to 2.8 kPa). IM PO2 declined from 24 to 8 Torr with 15% MVC, and approached 0 Torr at 30% MVC and 45% MVC. IM pH declined rapidly when IM PO2 reached 10 Torr and continued to decrease with increasing exertion, despite an IM PO2 near 0 Torr. C1 Univ Massachusetts, Sch Med, Dept Anesthesiol, Worcester, MA 01605 USA. NASA, Lyndon B Johnson Space Ctr, Exercise Physiol Lab, Houston, TX 77058 USA. RP Soller, BR (reprint author), Univ Massachusetts, Sch Med, Dept Anesthesiol, Worcester, MA 01605 USA. EM babs.soller@umassmed.edu NR 23 TC 10 Z9 11 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0967-3334 J9 PHYSIOL MEAS JI Physiol. Meas. PD JUN PY 2007 VL 28 IS 6 BP 639 EP 649 DI 10.1088/0967-3334/28/6/003 PG 11 WC Biophysics; Engineering, Biomedical; Physiology SC Biophysics; Engineering; Physiology GA 176SB UT WOS:000247104100003 PM 17664618 ER PT J AU Benna, M Mahaffy, P AF Benna, Mehdi Mahaffy, Paul TI Multi-fluid model of comet 1P/Halley SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd Annual Meeting of the Asia-Oceania-Geosciences-Society CY JUN 20-24, 2005 CL Singapore, SINGAPORE DE comet; Halley; multi-fluid MHD ID EFFECTIVE COLLISION FREQUENCY; SOLAR-WIND INTERACTION; INNER COMA; MHD SIMULATIONS; ION COMPOSITION; PLASMA-FLOW; HALLEY; P/HALLEY; GAS; ELECTRONS AB A new three-dimensional magneto hydrodynamic model of the coma of a comet has been developed and applied to simulations of a Halley-class coma using the solar-wind conditions of the Giotto flyby of Halley in 1986. The code developed for high-performance parallel processing computers, combines the high spatial resolution of smaller than I km grid spacing near the nucleus, with a large computational domain that enables structures nearly 10 million km down the comet tail to be modeled. Ions, neutrals, and electrons are considered as separate interacting fluids. Significant physical processes treated by the model include both photo and electron impact ionization of neutrals, recombination of ions, charge exchange between solar-wind ions and cometary neutrals, and frictional interactions between the three fluids considered in the model. A variety of plasma structures and physical parameters that are the output of this model are compared with relevant Giotto data from the 1986 Halley flyby. (c) 2006 Elsevier Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Benna, M (reprint author), NASA, Goddard Space Flight Ctr, Code 699, Greenbelt, MD 20771 USA. EM mehdi.benna@gsfc.nasa.gov; paul.r.mahaffy@gsfc.nasa.gov RI Mahaffy, Paul/E-4609-2012; Benna, Mehdi/F-3489-2012 NR 32 TC 10 Z9 10 U1 0 U2 0 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 2007 VL 55 IS 9 SI SI BP 1031 EP 1043 DI 10.1016/j.pss.2006.11.019 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189WH UT WOS:000248018800005 ER PT J AU Gulkis, S Allen, M Backus, C Beaudin, G Biver, N Bockelee-Morvan, D Crovisier, J Despois, D Encrenaz, P Frerking, M Hofstadter, M Hartogh, P Ip, W Janssen, M Kamp, L Koch, T Lellouch, E Mann, I Muhleman, D Rauer, H Schloerb, P Spilker, T AF Gulkis, Samuel Allen, Mark Backus, Charles Beaudin, Gerard Biver, Nicolas Bockelee-Morvan, Dominique Crovisier, Jacques Despois, Didier Encrenaz, Pierre Frerking, Margaret Hofstadter, Mark Hartogh, Paul Ip, Wing Janssen, Mike Kamp, Lucas Koch, Timothy Lellouch, Emmanuel Mann, Ingrid Muhleman, Duane Rauer, Heike Schloerb, Peter Spilker, Thomas TI Remote sensing of a comet at millimeter and submillimeter wavelengths from an orbiting spacecraft SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd Annual Meeting of the Asia-Oceania-Geosciences-Society CY JUN 20-24, 2005 CL Singapore, SINGAPORE DE comets; submillimeter spectroscopy; spacecraft instruments AB The ESA Rosetta Spacecraft, launched on March 2, 2004 with the ultimate destination being Comet 67P/Churyumov-Gerasimenko, carries a relatively small and lightweight millimeter-submillimeter spectrometer instrument, the first of its kind launched into deep space. The instrument, named Microwave Instrument for the Rosetta Orbiter (MIRO), consists of a 30-cm diameter, offset parabolic reflector telescope, which couples energy in the millimeter and submillimeter bands to two heterodyne receivers. Center-band operating frequencies are near 190 GHz (1.6 mm) and 562 GHz (0.5 mm). Broadband, total power continuum measurements can be made in both bands. A 4096-channel spectrometer with 44 kHz resolution is connected to the submillimeter receiver. The spectral resolution is sufficient to observe individual, thermally broadened spectral lines (T >= 10K). The submillimeter radiometer/spectrometer is fixed tuned to measure four volatile species-CO, CH3OH, NH3 and three isotopes of water, (H2O)-O-16,(H2O)-O-17 and (H2O)-O-18. The MIRO experiment will use these species as probes of the physical conditions within the nucleus and coma. The basic quantities measured by MIRO are surface temperature, gas production rates and relative abundances, and velocity and excitation temperature of each species, along with their spatial and temporal variability. This information will be used to infer coma structure and outgassing processes, including the nature of the nucleus/coma interface. (c) 2006 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Observ Paris, F-75014 Paris, France. Observ Bordeaux, Bordeaux, France. Natl Cent Univ, Chungli, Taiwan. Univ Wilhelm, Wilhelmshaven, Germany. DLR, Inst Planetenerkundung, Berlin, Germany. Univ Massachusetts, Amherst, MA 01003 USA. RP Gulkis, S (reprint author), CALTECH, Jet Prop Lab, MS 169-506, Pasadena, CA 91109 USA. EM samuel.gulkis@jpl.nasa.gov NR 12 TC 14 Z9 15 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JUN PY 2007 VL 55 IS 9 SI SI BP 1050 EP 1057 DI 10.1016/j.pss.2006.11.011 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189WH UT WOS:000248018800007 ER PT J AU Branduardi-Raymont, G Bhardwaj, A Elsner, RF Gladstone, GR Rarnsay, G Rodriguez, P Soria, R Waite, JH Cravens, TE AF Branduardi-Raymont, G. Bhardwaj, A. Elsner, R. F. Gladstone, G. R. Rarnsay, G. Rodriguez, P. Soria, R. Waite, J. H., Jr. Cravens, T. E. TI Latest results on Jovian disk X-rays from XMM-Newton SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd Annual Meeting of the Asia-Oceania-Geosciences-Society CY JUN 20-24, 2005 CL Singapore, SINGAPORE DE planets; jupiter; X-rays ID JUPITER; EMISSION; SPECTROMETER AB We present the results of a spectral study of the soft X-ray emission (0.2-2.5 keV) from low-latitude ('disk') regions of Jupiter. The data were obtained during two observing campaigns with XMM-Newton in April and November 2003. While the level of the emission remained approximately the same between April and the first half of the November observation, the second part of the latter shows an enhancement by about 40% in the 0.2-2.5 keV flux. A very similar, and apparently correlated increase, in time and scale, was observed in the solar X-ray and EUV flux. The months of October and November 2003 saw a period of particularly intense solar activity, which appears reflected in the behavior of the soft X-rays from Jupiter's disk. The X-ray spectra, from the XMM-Newton EPIC CCD cameras, are all well fitted by a coronal model with temperatures in the range 0.4-0.5 keV, with additional line emission from Mg XI (1.35 keV) and Si XIII (1.86 keV): these are characteristic lines of solar X-ray spectra at maximum activity and during flares. The XMM-Newton observations lend further support to the theory that Jupiter's disk X-ray emission is controlled by the Sun, and may be produced in large part by scattering, elastic and fluorescent, of solar X-rays in the upper atmosphere of the planet. (c) 2006 Elsevier Ltd. All rights reserved. C1 UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Vikram Sarabhai Space Ctr, Space Phys Lab, Trivandrum 695022, Kerala, India. NASA, Marshall Space Flight Ctr, NSSTC XD12, Huntsville, AL 35805 USA. SW Res Inst, San Antonio, TX 78228 USA. XMM Newton SOC, Madrid 28080, Spain. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. RP Branduardi-Raymont, G (reprint author), UCL, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England. EM gbr@mssl.ucl.ac.uk OI Bhardwaj, Anil/0000-0003-1693-453X NR 20 TC 20 Z9 20 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JUN PY 2007 VL 55 IS 9 SI SI BP 1126 EP 1134 DI 10.1016/j.pss.2006.11.017 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189WH UT WOS:000248018800013 ER PT J AU Bhardwaj, A Elsner, RF Gladstone, GR Cravens, TE Lisse, CM Dennerl, K Branduardi-Raymont, G Wargelin, BJ Waite, JH Robertson, I Ostgaard, N Beiersdorfer, P Snowden, SL Kharchenko, V AF Bhardwaj, Anil Elsner, Ronald F. Gladstone, G. Randall Cravens, Thomas E. Lisse, Carey M. Dennerl, Konrad Branduardi-Raymont, Graziella Wargelin, Bradford J. Waite, J. Hunter, Jr. Robertson, Ina Ostgaard, Nikolai Beiersdorfer, Peter Snowden, Steven L. Kharchenko, Vasili TI X-rays from solar system objects SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd Annual Meeting of the Asia-Oceania-Geosciences-Society CY JUN 20-24, 2005 CL Singapore, SINGAPORE DE planets; minor bodies; planetary satellites; comets; X-ray emission; solar wind; heliosphere; atmosphere ID IO PLASMA TORUS; WIND CHARGE-EXCHANGE; SELECTIVE ELECTRON-CAPTURE; HUBBLE-SPACE-TELESCOPE; PARTICLE ENVIRONMENT MONITOR; EXTREME-ULTRAVIOLET EMISSION; JOVIAN AURORAL ELECTRONS; ASTEROID 433 EROS; COMET HALE-BOPP; ALL-SKY SURVEY AB During the last few years our knowledge about the X-ray emission from bodies within the solar system has significantly improved. Several new solar system objects are now known to shine in X-rays at energies below 2 keV. Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites (Moon, Io, Europa, and Ganymede), all active comets, the Io plasma torus (IPT), the rings of Saturn, the coronae (exospheres) of Earth and Mars, and the heliosphere. The advent of higher-resolution X-ray spectroscopy with the Chandra and XMM-Newton X-ray observatories has been of great benefit in advancing the field of planetary X-ray astronomy. Progress in modeling X-ray emission, laboratory studies of X-ray production, and theoretical calculations of cross-sections, have all contributed to our understanding of processes that produce X-rays from the solar system bodies. At Jupiter and Earth, both auroral and non-auroral disk X-ray emissions have been observed. X-rays have been detected from Saturn's disk, but no convincing evidence of an X-ray aurora has been observed. The first soft (0.1-2 keV) X-ray observation of Earth's aurora by Chandra shows that it is highly variable. The non-auroral X-ray emissions from Jupiter, Saturn, and Earth, those from the disk of Mars, Venus, and Moon, and from the rings of Saturn, are mainly produced by scattering of solar X-rays. The spectral characteristics of X-ray emission from comets, the heliosphere, the geocorona, and the Martian halo are quite similar, but they appear to be quite different from those of Jovian auroral X-rays. X-rays from the Galilean satellites and the IPT are mostly driven by impact of Jovian magnetospheric particles. This paper reviews studies of the soft X-ray emission from the solar system bodies, excluding the Sun. Processes of production of solar system X-rays are discussed and an overview is provided of the main source mechanisms of X-ray production at each object. A brief account on recent development in the area of laboratory studies of X-ray production is also provided. (c) 2007 Elsevier Ltd. All rights reserved. C1 Vikram Sarabhai Space Ctr, Space Phys Lab, Trivandrum 685022, Kerala, India. NASA, Marshall Space Flight Ctr, NSSTC XD12, Space Sci Branch, Huntsville, AL 35805 USA. SW Res Inst, San Antonio, TX 78228 USA. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. MPI Extraterrest Phys, D-85748 Garching, Germany. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Bergen, Dept Phys & Technol, N-5007 Bergen, Norway. Lawrence Livermore Natl Lab, Dept Phys, Livermore, CA 94550 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bhardwaj, A (reprint author), Vikram Sarabhai Space Ctr, Space Phys Lab, Trivandrum 685022, Kerala, India. EM anil_bhardwaj@vssc.gov.in; ron.elsner@msfc.nasa.gov; randy.gladstone@swri.org; cravens@ku.edu; carey.lisse@jhuapl.edu; kod@mpe.mpg.de; gbr@mssl.ucl.ac.uk; bwargelin@cfa.harvard.edu; hwaite@swri.edu; robertin@ku.edu; nikost@ift.uib.no; beiersdorfer@llnl.gov; snowden@milkyway.gsfc.nasa.gov; vkharchenko@cfa.harvard.edu RI Snowden, Steven/D-5292-2012; Lisse, Carey/B-7772-2016; OI Lisse, Carey/0000-0002-9548-1526; Bhardwaj, Anil/0000-0003-1693-453X NR 250 TC 73 Z9 73 U1 1 U2 11 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 2007 VL 55 IS 9 SI SI BP 1135 EP 1189 DI 10.1016/j.pss.2006.11.009 PG 55 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 189WH UT WOS:000248018800014 ER PT J AU Klein, DJ Topping, CC Bryant, RG AF Klein, Daniel J. Topping, Crystal C. Bryant, Robert G. TI Synthesis and characterization of polyimides derived from cyano-containing 1,4-bis(4-aminophenoxy) benzene monomers SO POLYMER BULLETIN LA English DT Article DE polyimides; glass transition; piezoelectric; cyano; mechanical properties; thermal properties; synthesis ID POLY(VINYLIDENE FLUORIDE); FERROELECTRIC BEHAVIOR; NYLON 11; DIELECTRIC-PROPERTIES; VINYLIDENE FLUORIDE; THIN-FILMS; COPOLYMER; PIEZOELECTRICITY AB A series of three new cyano-containing diamines based upon 1,4-bis( 4-aminophenoxy) benzene was synthesized and polymerized with six different dianhydrides to yield 18 different polyimides. Due to the high dipole moment of the cyano group, it was believed that these polymers would display differing degrees of electroactivity depending upon the degree and position of cyano substitution. The type of dianhydride bridging group and length are also factors that affect the electroactivity of polyimides. Polyimides based upon 1,4-bis(4-aminophenoxy) benzene were used as reference materials by which the respective cyano-containing analogs were compared. As the degree of cyano group substitution increased, the glass transition temperature increased. As cyano substitution increased, the polymer chain flexibility decreased due to hindered rotation about the phenyl-ether-phenyl linkages in the diamine portion of the polymer. The tensile moduli ranged from 2.97 to 4.57 GPa and ultimate tensile strengths from 79 to 156 MPa, which are typical values of aromatic polyimides. C1 NASA, Langley Res Ctr, Appl Technol & Testing Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. RP Klein, DJ (reprint author), Ashland Performance Mat, 5200 Blazer Pkwy, Dublin, OH 43235 USA. EM djklein@ashland.com NR 23 TC 2 Z9 2 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0170-0839 J9 POLYM BULL JI Polym. Bull. PD JUN PY 2007 VL 59 IS 1 BP 1 EP 12 DI 10.1007/s00289-007-0742-4 PG 12 WC Polymer Science SC Polymer Science GA 193WH UT WOS:000248305400001 ER PT J AU Knutson, HA Charbonneau, D Deming, D Richardson, LJ AF Knutson, Heather A. Charbonneau, David Deming, Drake Richardson, L. Jeremy TI A ground-based search for thermal emission from the exoplanet TrES-1 SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID SECONDARY ECLIPSE; EXTRASOLAR PLANET; INFRARED OBSERVATIONS; TRANSITING PLANET; HD 189733B; SPECTROSCOPY; ATMOSPHERES; PHOTOMETRY; SPECTRUM; HD-209458B AB Eclipsing planetary systems give us an important window on extrasolar planet atmospheres. By measuring the depth of the secondary eclipse, when the planet moves behind the star, we can estimate the strength of the thermal emission from the day side of the planet. Obtaining a ground-based detection of one of these eclipses has proven to be a significant challenge, as time-dependent variations in instrument throughput and atmospheric seeing and absorption overwhelm the small signal of the eclipse at infrared wavelengths. We gathered a series of simultaneous L grism spectra of the transiting planet system TrES-1 and a nearby comparison star of comparable brightness, allowing us to correct for these effects, in principle. Combining the data from two eclipses, we demonstrate a detection sensitivity of 0.15% in the eclipse depth relative to the stellar flux. This approaches the sensitivity required to detect the planetary emission, which theoretical models predict should lie between 0.05% and 0.1% of the stellar flux in our 2.9-4.3 mu m bandpass. We explore the factors that ultimately limit the precision of this technique, and discuss potential avenues for future improvements. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Planetary Syst Lab, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Exoplanet & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. RP Knutson, HA (reprint author), Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. EM hknutson@cfa.harvard.edu; dcharbonneau@cfa.harvard.edu; ddeming@pop600.gsfc.nasa.gov; richardsonlj@milkyway.gsfc.nasa.gov OI Charbonneau, David/0000-0002-9003-484X NR 27 TC 14 Z9 14 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JUN PY 2007 VL 119 IS 856 BP 616 EP 622 DI 10.1086/520098 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 183RV UT WOS:000247590800003 ER PT J AU Cucinotta, FA Durante, M Petrov, V AF Cucinotta, Francis A. Durante, Marco Petrov, Vladislav TI Fourth International Workshop on Space Radiation Research (IWSRR) SO RADIATION AND ENVIRONMENTAL BIOPHYSICS LA English DT Editorial Material C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Naples Federico II, Dept Phys, I-80126 Naples, Italy. Univ Naples Federico II, Ist Nazl Fis Nucl, I-80126 Naples, Italy. Russian Acad Sci, Inst Biomed Problems, Moscow, Russia. RP Cucinotta, FA (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM Francis.A.Cucinotta@nasa.gov RI Durante, Marco/K-1315-2014; OI Durante, Marco/0000-0002-4615-553X NR 5 TC 1 Z9 1 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0301-634X J9 RADIAT ENVIRON BIOPH JI Radiat. Environ. Biophys. PD JUN PY 2007 VL 46 IS 2 BP 89 EP 90 DI 10.1007/s00411-007-0111-6 PG 2 WC Biology; Biophysics; Environmental Sciences; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Environmental Sciences & Ecology; Radiology, Nuclear Medicine & Medical Imaging GA 166EF UT WOS:000246360000001 ER PT J AU Kim, MHY Cucinotta, FA Wilson, JW AF Kim, Myung-Hee Y. Cucinotta, Francis A. Wilson, John W. TI A temporal forecast of radiation environments for future space exploration missions SO RADIATION AND ENVIRONMENTAL BIOPHYSICS LA English DT Article; Proceedings Paper CT 4th International Workshop on Space Radiation Research/17th Annual NASA Space Radiation Health Investigators Meeting CY JUN 05-09, 2006 CL St Petersburg, RUSSIA ID GALACTIC COSMIC-RADIATION; MODEL; EVENTS; RISK AB The understanding of future space radiation environments is an important goal for space mission operations, design, and risk assessment. We have developed a solar cycle statistical model in which sunspot number is coupled to space-related quantities, such as the galactic cosmic radiation (GCR) deceleration potential (phi) and the mean occurrence frequency of solar particle events (SPEs). Future GCR fluxes were derived from a predictive model, in which the temporal dependence represented by phi was derived from GCR flux and ground-based Climax neutron monitor rate measurements over the last four decades. These results showed that the point dose equivalent inside a typical spacecraft in interplanetary space was influenced by solar modulation by up to a factor of three. It also has been shown that a strong relationship exists between large SPE occurrences and phi. For future space exploration missions, cumulative probabilities of SPEs at various integral fluence levels during short-period missions were defined using a database of proton fluences of past SPEs. Analytic energy spectra of SPEs at different ranks of the integral fluences for energies greater than 30 MeV were constructed over broad energy ranges extending out to GeV for the analysis of representative exposure levels at those fluences. Results will guide the design of protection systems for astronauts during future space exploration missions. C1 Wyle Labs, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Kim, MHY (reprint author), Wyle Labs, Wyle HAC-37A,1290 Hercules Dr, Houston, TX 77058 USA. EM myung-hee.y.kim@nasa.gov OI Kim, Myung-Hee/0000-0001-5575-6858 NR 19 TC 11 Z9 11 U1 0 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0301-634X J9 RADIAT ENVIRON BIOPH JI Radiat. Environ. Biophys. PD JUN PY 2007 VL 46 IS 2 BP 95 EP 100 DI 10.1007/s00411-006-0080-1 PG 6 WC Biology; Biophysics; Environmental Sciences; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Environmental Sciences & Ecology; Radiology, Nuclear Medicine & Medical Imaging GA 166EF UT WOS:000246360000003 PM 17165049 ER PT J AU Cucinotta, FA Kim, MH Schneider, SI Hassler, DM AF Cucinotta, Francis A. Kim, Myung-Hee Schneider, Susana I. Hassler, Donald M. TI Description of light ion production cross sections and fluxes on the Mars surface using the QMSFRG model SO RADIATION AND ENVIRONMENTAL BIOPHYSICS LA English DT Article; Proceedings Paper CT 4th International Workshop on Space Radiation Research/17th Annual NASA Space Radiation Health Investigators Meeting CY JUN 05-09, 2006 CL St Petersburg, RUSSIA ID GALACTIC COSMIC-RAYS; COLLISIONS; ATMOSPHERE; EXPOSURE; METHANE; RISKS AB The atmosphere of Mars significantly attenuates the heavy ion component of the primary galactic cosmic rays (GCR), however, increases the fluence of secondary light ions (neutrons, and hydrogen and helium isotopes) because of particle production processes. We describe results of the quantum multiple scattering fragmentation (QMSFRG) model for the production of light nuclei through the distinct mechanisms of nuclear abrasion and ablation, coalescence, and cluster knockout. The QMSFRG model is shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections. We use the QMSFRG model and the space radiation transport code, HZETRN to make predictions of the light particle environment on the Martian surface at solar minimum and near maximum. The radiation assessment detector (RAD) experiment will be launched in 2009 as part of the Mars Science Laboratory (MSL). We make predictions of the expected results for time dependent count-rates to be observed by the RAD experiment. Finally, we consider sensitivity assessments of the impact of the Martian atmospheric composition on particle fluxes at the surface. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Penn State Univ, State Coll, PA USA. SW Res Inst, Boulder, CO USA. RP Cucinotta, FA (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM francis.a.cucinotta@nasa.gov OI Kim, Myung-Hee/0000-0001-5575-6858 NR 20 TC 12 Z9 13 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0301-634X J9 RADIAT ENVIRON BIOPH JI Radiat. Environ. Biophys. PD JUN PY 2007 VL 46 IS 2 BP 101 EP 106 DI 10.1007/s00411-007-0099-y PG 6 WC Biology; Biophysics; Environmental Sciences; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Environmental Sciences & Ecology; Radiology, Nuclear Medicine & Medical Imaging GA 166EF UT WOS:000246360000004 PM 17342547 ER EF