FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Gauci, V Matthews, E Dise, N Walter, B Koch, D Granberg, G Vile, M AF Gauci, V Matthews, E Dise, N Walter, B Koch, D Granberg, G Vile, M TI Sulfur pollution suppression of the wetland methane source in the 20th and 21st centuries SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SULFATE REDUCERS; ATMOSPHERIC METHANE; NATURAL WETLANDS; EMISSIONS; SEDIMENTS; PEATLAND; CO2; METHANOGENESIS; TEMPERATURE; DEPOSITION AB Natural wetlands form the largest source of methane (CH4) to the atmosphere. Emission of this powerful greenhouse gas from wetlands is known to depend on climate, with increasing temperature and rainfall both expected to increase methane emissions. This study, combining our field and controlled environment manipulation studies in Europe and North America, reveals an additional control: an emergent pattern of increasing suppression of methane (CH4) emission from peatlands with increasing sulfate (SO42-S) 4 deposition, within the range of global acid deposition. We apply a model of this relationship to demonstrate the potential effect of changes in global sulfate deposition from 1960 to 2080 on both northern peatland and global wetland CH4 emissions. We estimate that sulfur pollution may currently counteract climate-induced growth in the wetland source, reducing CH4 emissions by approximate to15 Tg or 8% smaller than it would be in the absence of global acid deposition. Our findings suggest that by 2030 sulfur pollution may be sufficient to reduce CH4 emissions by 26 Tg or 15% of the total wetland source, a proportion as large as other components of the CH4 budget that have until now received far greater attention. We conclude that documented increases in atmospheric CH4 concentration since the late 19th century are likely due to factors other than the global warming of wetlands. C1 Open Univ, Dept Earth Sci, Milton Keynes MK7 6AA, Bucks, England. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Villanova Univ, Dept Biol, Villanova, PA 19085 USA. Swedish Univ Agr Sci, Dept Forest Ecol, S-90183 Umea, Sweden. Acad Nat Sci Philadelphia, Patrick Ctr Environm Res, Philadelphia, PA 19103 USA. RP Gauci, V (reprint author), Open Univ, Dept Earth Sci, Milton Keynes MK7 6AA, Bucks, England. EM v.gauci@open.ac.uk NR 43 TC 68 Z9 72 U1 6 U2 19 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD AUG 24 PY 2004 VL 101 IS 34 BP 12583 EP 12587 DI 10.1073/pnas.0404412101 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 850FI UT WOS:000223596200035 PM 15297612 ER PT J AU Bres, GA Brentner, KS Perez, G Jones, HE AF Bres, GA Brentner, KS Perez, G Jones, HE TI Maneuvering rotorcraft noise prediction SO JOURNAL OF SOUND AND VIBRATION LA English DT Article; Proceedings Paper CT American-Helicopter-Society-International Specialists Meeting on Aerodynamics, Acoustics and Test and Evaluation CY JAN 23-25, 2002 CL San Francisco, CA SP Amer Helicopter Soc Int AB This paper presents the unique aspects of the development of an entirely new maneuver noise prediction code called PSU-WOPWOP. The main focus of this work is development of a noise prediction methodology, which will enable the study of the aeroacoustic aspects a rotorcraft in maneuvering flight. It is assumed that the aeromechanical data (namely aircraft and blade motion, blade airloads) are provided as input data. This new noise prediction capability was developed for rotors in steady and transient maneuvering flight. Featuring an object-oriented design, the PSU-WOPWOP code allows great flexibility for complex rotor configuration and motion (including multiple rotors and full aircraft motion). The relative locations and number of hinges, flexures, and body motions can be arbitrarily specified to match any specific rotorcraft. An analysis of algorithm efficiency was performed for maneuver noise prediction along with a description of the tradeoffs made specifically for the maneuvering noise problem. Noise predictions for the mainrotor of a rotorcraft in steady descent, transient (arrested) descent, hover and a "pop-up" maneuver are demonstrated. (C) 2003 Elsevier Ltd. All rights reserved. C1 Penn State Univ, Dept Aerosp Engn, University Pk, PA 16802 USA. USA, NASA, Aeroflightdynam Directorate, Aviat & Missile Command,Langley Res Ctr,AMRDEC, Hampton, VA 23681 USA. RP Penn State Univ, Dept Aerosp Engn, University Pk, PA 16802 USA. EM ksbrentner@psu.edu NR 16 TC 9 Z9 9 U1 0 U2 1 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X EI 1095-8568 J9 J SOUND VIB JI J. Sound Vibr. PD AUG 23 PY 2004 VL 275 IS 3-5 BP 719 EP 738 DI 10.1016/j.jsv.2003.07.005 PG 20 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 837PU UT WOS:000222648500014 ER PT J AU Cody, R Pimentel, AS Payne, W Nesbitt, FL AF Cody, R Pimentel, AS Payne, W Nesbitt, FL TI Total rate constant for the CH3C2H5 reaction at low temperatures and pressures. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA. EM regina.cody@nasa.gov RI Pimentel, Andre/B-1278-2010; Cody, Regina/D-5996-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 529-PHYS BP U279 EP U279 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851VJ UT WOS:000223713801480 ER PT J AU Cohn, CA Mueller, S Wimmer, E Schoonen, M AF Cohn, CA Mueller, S Wimmer, E Schoonen, M TI Pyrite-generated radicals and the destruction of nucleic acids. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. NASA, Astrobiol Inst, Stony Brook, NY 11794 USA. EM ccohn@ic.sunysb.edu NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 049-GEOC BP U698 EP U698 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802903 ER PT J AU Dworkin, JP Moore, MH Deamer, DW AF Dworkin, JP Moore, MH Deamer, DW TI Synthesis of membranous structures from cosmic-ray bombarded interstellar ices in the laboratory. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, Goddard Space Flight Ctr, Astrochem Branch, Greenbelt, MD 20771 USA. Univ Calif Santa Cruz, Dept Chem & Biochem, Santa Cruz, CA 95064 USA. EM Jason.P.Dworkin@nasa.gov RI Dworkin, Jason/C-9417-2012 OI Dworkin, Jason/0000-0002-3961-8997 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 015-GEOC BP U692 EP U692 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802869 ER PT J AU Lee, TJ AF Lee, TJ TI Theoretical studies of atmospheric chemistry and developments in coupled-cluster theory. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, Ames Res Ctr, Computat Chem Grp, Moffett Field, CA 94035 USA. EM tjlee@mail.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 194-COMP BP U530 EP U530 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802221 ER PT J AU Lee, TJ Mejia, CN Beran, GJO Head-Gordon, M AF Lee, TJ Mejia, CN Beran, GJO Head-Gordon, M TI Search for possible stratospheric bromine reservoir species: Theoretical study of the photostability of mono-, tri-, and pentacoordinated bromine compounds. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM tjlee@mail.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 107-PHYS BP U216 EP U216 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851VJ UT WOS:000223713801066 ER PT J AU MacDougall, PJ Henze, CE AF MacDougall, PJ Henze, CE TI Conquer without dividing: Volume rendering of intact molecular charge densities effectively illustrates key concepts in bonding and reactivity. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 Middle Tennessee State Univ, Dept Chem, Murfreesboro, TN 37132 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM pmacdougall@mtsu.edu RI MacDougall, Preston/N-2515-2016 OI MacDougall, Preston/0000-0002-0403-000X NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 096-COMP BP U515 EP U515 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802123 ER PT J AU Michelsen, RR Roberts, JT AF Michelsen, RR Roberts, JT TI Uptake of 2,5-hexanedione by ultrathin sulfate films: Kinetic and surface effects. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, Dept Atmospher Chem & Dynam, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. EM rmichelsen@mail.arc.nasa.gov NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 577-PHYS BP U286 EP U286 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851VJ UT WOS:000223713801528 ER PT J AU Michelsen, RR Staton, SJR Iraci, LT AF Michelsen, RR Staton, SJR Iraci, LT TI How does chemistry affect gas uptake? Oxygenated organics and sulfuric acid. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, Ames Res Ctr, Dept Atmospher Chem & Dynam, Moffett Field, CA 94035 USA. EM rmichelsen@mail.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 285-PHYS BP U243 EP U243 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851VJ UT WOS:000223713801242 ER PT J AU Mollner, AK Nair, GP Alconcel, LS Okumura, M Sander, SP AF Mollner, AK Nair, GP Alconcel, LS Okumura, M Sander, SP TI Measuring the yield of cis-cis HOONO in the reaction OH+NO2 as a function of pressure. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91125 USA. EM mollner@caltech.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 518-PHYS BP U277 EP U277 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851VJ UT WOS:000223713801469 ER PT J AU Pohorille, A Wilson, MA AF Pohorille, A Wilson, MA TI Structure, function and origin of simple membrane proteins. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, Ames Res Ctr, Ctr Computat Astrobiol, Moffett Field, CA 94035 USA. Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. EM pohorill@raphael.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 014-GEOC BP U692 EP U692 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802868 ER PT J AU Runnegar, B Field, M Coath, CD Lyons, JR McKeegan, KD Mojzsis, SJ AF Runnegar, B Field, M Coath, CD Lyons, JR McKeegan, KD Mojzsis, SJ TI Mass-dependent and mass-independent sulfur isotope fractionations in the last 3.5 billion years of earth history. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, Ames Res Ctr, Astrobiol Inst, Moffett Field, CA 94035 USA. Univ Bristol, Dept Earth Sci, Bristol BS8 1TH, Avon, England. Univ Calif Los Angeles, IGPP, Ctr Astrobiol, Los Angeles, CA 90024 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. Univ Colorado, Dept Geol Sci, Ctr Astrobiol, Boulder, CO 80309 USA. EM bruce.runnegar@nasa.gov RI McKeegan, Kevin/A-4107-2008 OI McKeegan, Kevin/0000-0002-1827-729X NR 0 TC 0 Z9 0 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 057-GEOC BP U699 EP U699 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802911 ER PT J AU Sander, SP Alconcel, LS Christensen, LE Francisco, JS Friedl, RR Hansen, JC Okumura, M Robichaud, D AF Sander, SP Alconcel, LS Christensen, LE Francisco, JS Friedl, RR Hansen, JC Okumura, M Robichaud, D TI Reaction kinetics of atmospheric hydrogen oxide and halogen oxide radicals. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. CALTECH, Dept Chem, Pasadena, CA 91125 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. EM ssander@jpl.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 106-PHYS BP U216 EP U216 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851VJ UT WOS:000223713801065 ER PT J AU Santos, J Meador, MA AF Santos, J Meador, MA TI Synthesis and properties of fluorescent benzofuran dyes for potential biological applications. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, GRC, Ohio Aerosp Inst, Cleveland, OH 44135 USA. NASA, GRC, Div Mat, Cleveland, OH 44135 USA. EM Javier.Santos@grc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 148-BIOL BP U195 EP U195 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712800840 ER PT J AU Santos, J Meador, MA AF Santos, J Meador, MA TI Efficient cyclocondensation affording benzofurans under cyanide ion conditions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Polymer Branch, Div Mat, Cleveland, OH 44135 USA. EM Javier.Santos@grc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 665-ORGN BP U144 EP U144 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851VJ UT WOS:000223713800730 ER PT J AU Schoonen, M Smirnov, A Cohn, CA AF Schoonen, M Smirnov, A Cohn, CA TI Role of minerals in prebiotic synthesis: A perspective. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. NASA, Astrobiol Inst, Stony Brook, NY 11794 USA. EM martin.schoonen@sunysb.edu NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 042-GEOC BP U697 EP U697 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802896 ER PT J AU Smirnov, A Tosca, NJ Chidambaram, D Halada, GP Schoonen, M AF Smirnov, A Tosca, NJ Chidambaram, D Halada, GP Schoonen, M TI Ni-(Fe) alloy and sulfide formation during forsterite-fayalite dissolution at hydrothermal conditions: Importance for prebiotic synthesis. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. NASA, Astrobiol Inst, Stony Brook, NY 11794 USA. EM asmirnov@ic.sunysb.edu RI Chidambaram, Dev/B-2967-2008 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 029-GEOC BP U695 EP U695 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802883 ER PT J AU Trainer, MG Pavlov, AA Curtis, DB McKay, CP Worsnop, DR Delia, AE Toohey, DW Toon, OB Tolbert, MA AF Trainer, MG Pavlov, AA Curtis, DB McKay, CP Worsnop, DR Delia, AE Toohey, DW Toon, OB Tolbert, MA TI Haze aerosols in the atmosphere of early earth: Manna from heaven. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Div Space Sci, Ames Res Ctr, Moffett Field, CA USA. Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. Univ Colorado, Aerodyne Res, Boulder, CO 80309 USA. Univ Colorado, Dept Chem, Boulder, CO 80309 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. EM melissa.trainer@colorado.edu NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 035-GEOC BP U696 EP U696 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802889 ER PT J AU Valluvadasan, S Milligan, DB Sander, SP AF Valluvadasan, S Milligan, DB Sander, SP TI Kinetics study of the reaction OH+NO2+M: Pressure- and temperature-dependent falloff parameters. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91125 USA. EM siva@jpl.nasa.gov; ssander@jpl.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 496-PHYS BP U274 EP U274 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851VJ UT WOS:000223713801447 ER PT J AU Vander Wall, RL Ticich, TM Berger, GM AF Vander Wall, RL Ticich, TM Berger, GM TI Flame synthesis of carbon nanotubes using catalyst particles prepared by laser ablation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 228th National Meeting of the American-Chemical-Society CY AUG 22-26, 2004 CL Philadelphia, PA SP Amer Chem Soc C1 NASA, NCMR, Cleveland, OH 44135 USA. EM randy@rvander.grc.nasa.gov NR 0 TC 0 Z9 0 U1 2 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 2004 VL 228 MA 182-FUEL BP U680 EP U680 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 851UZ UT WOS:000223712802809 ER PT J AU Wang, JS Logan, JA McElroy, MB Duncan, BN Megretskaia, IA Yantosca, RM AF Wang, JS Logan, JA McElroy, MB Duncan, BN Megretskaia, IA Yantosca, RM TI A 3-D model analysis of the slowdown and interannual variability in the methane growth rate from 1988 to 1997 SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Review DE methane; interannual variability; inverse modeling; chemical transport model (CTM); hydroxyl; inventory ID 1,1,1-TRICHLOROETHANE METHYL CHLOROFORM; ATMOSPHERIC METHANE; RICE FIELDS; TROPOSPHERIC CHEMISTRY; ISOTOPIC COMPOSITION; NORTHERN-HEMISPHERE; GENERAL-CIRCULATION; EMISSIONS INVENTORY; GLOBAL DISTRIBUTION; DRAMATIC DECREASE AB [1] Methane has exhibited significant interannual variability with a slowdown in its growth rate beginning in the 1980s. We use a 3-D chemical transport model accounting for interannually varying emissions, transport, and sinks to analyze trends in CH4 from 1988 to 1997. Variations in CH4 sources were based on meteorological and country-level socioeconomic data. An inverse method was used to optimize the strengths of sources and sinks for a base year, 1994. We present a best-guess budget along with sensitivity tests. The analysis suggests that the sum of emissions from animals, fossil fuels, landfills, and wastewater estimated using Intergovernmental Panel on Climate Change default methodology is too high. Recent bottom-up estimates of the source from rice paddies appear to be too low. Previous top-down estimates of emissions from wetlands may be a factor of 2 higher than bottom-up estimates because of possible overestimates of OH. The model captures the general decrease in the CH4 growth rate observed from 1988 to 1997 and the anomalously low growth rates during 1992 - 1993. The slowdown in the growth rate is attributed to a combination of slower growth of sources and increases in OH. The economic downturn in the former Soviet Union and Eastern Europe made a significant contribution to the decrease in the growth rate of emissions. The 1992 - 1993 anomaly can be explained by fluctuations in wetland emissions and OH after the eruption of Mount Pinatubo. The results suggest that the recent slowdown of CH4 may be temporary. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. RP Environm Def, 257 Pk Ave S, New York, NY 10010 USA. EM jwang@ed.org; jal@io.harvard.edu; mbm@io.harvard.edu; duncan@hyperion.gsfc.nasa.gov; iam@io.harvard.edu; bmy@io.harvard.edu RI 欧阳, 冰洁/G-2925-2011; Duncan, Bryan/A-5962-2011; Yantosca, Robert/F-7920-2014 OI Yantosca, Robert/0000-0003-3781-1870 NR 108 TC 103 Z9 109 U1 0 U2 30 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 EI 1944-9224 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD AUG 21 PY 2004 VL 18 IS 3 AR GB3011 DI 10.1029/2003GB002180 PG 31 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 849NJ UT WOS:000223545200001 ER PT J AU Dicello, JF Christian, A Cucinotta, FA Gridley, DS Kathirithamby, R Mann, J Markham, AR Moyers, MF Novak, GR Piantadosi, S Ricart-Arbona, R Simonson, DM Strandberg, JD Vazquez, M Williams, JR Zhang, Y Zhou, H Huso, D AF Dicello, JF Christian, A Cucinotta, FA Gridley, DS Kathirithamby, R Mann, J Markham, AR Moyers, MF Novak, GR Piantadosi, S Ricart-Arbona, R Simonson, DM Strandberg, JD Vazquez, M Williams, JR Zhang, Y Zhou, H Huso, D TI In vivo mammary tumourigenesis in the Sprague-Dawley rat and microdosimetric correlates SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Article; Proceedings Paper CT World Congress on Medical Physics and Biomedical Engineering CY AUG 24-29, 2003 CL Sydney, AUSTRALIA ID RADIATION RISKS; SPACE; CARCINOGENESIS; GLAND; SUSCEPTIBILITY; INDUCTION; NEOPLASMS; BIOLOGY; PROTON; RAYS AB Standard methods for risk assessments resulting from human exposures to mixed radiation fields in Space consisting of different particle types and energies rely upon quality factors. These are generally defined as a function of linear energy transfer (LET) and are assumed to be proportional to the risk: In this approach, it is further assumed that the risks for single exposures from, each of the radiation types add linearly. Although risks of cancer from acute e exposures to photon radiations have been measured in humans, quality factors for protons and ions of heavier atomic mass are generally inferred from animal, and/or cellular data. Because only a small amount of data exists for such particles, this group has been examining tumourigenesis initiated by energetic protons and iron ions. In this study, 741 female Sprague-Dawley rats were irradiated or sham irradiated at approximately 60 days of age with 250 MeV protons, 1 GeV/nucleon iron ions or both protons and iron ions. The results suggest that the risk of mammary tumours in the rats sequentially irradiated with 1 GeV/nucleon 56 Fe ions and 250 MeV protons is less than additive. These data in conjunction with earlier results further suggest that risk assessments in terms of only mean LETs of the primary cosmic rays may be insufficient to accurately evaluate the relative risks of each type of particle in a radiation field of mixed radiation qualities. C1 Johns Hopkins Univ, Sidney Kimmel Comprehens Canc Ctr, Dept Radiat Oncol & Mol Radiat Sci, Baltimore, MD 21231 USA. Johns Hopkins Univ, Sch Med, Dept Comparat Med, Baltimore, MD 21231 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Loma Linda Univ, Sch Med, Loma Linda, CA 92350 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Dicello, JF (reprint author), Johns Hopkins Univ, Sidney Kimmel Comprehens Canc Ctr, Dept Radiat Oncol & Mol Radiat Sci, Baltimore, MD 21231 USA. EM diceljo@jhmi.edu; fcucinot@ems.jsc.nasa.gov; dgridley@dominion.llumc.edu; Vazquez@bnl.gov RI Gridley, Daila/P-7711-2015 NR 39 TC 47 Z9 47 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0031-9155 J9 PHYS MED BIOL JI Phys. Med. Biol. PD AUG 21 PY 2004 VL 49 IS 16 BP 3817 EP 3830 AR PII S0031-9155(04)79299-4 DI 10.1088/0031-9155/49/16/024 PG 14 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA 852BH UT WOS:000223729700025 PM 15446807 ER PT J AU Verner, E Bruhweiler, F Verner, D Johansson, S Kallman, T Gull, T AF Verner, E Bruhweiler, F Verner, D Johansson, S Kallman, T Gull, T TI FeII diagnostic tools for quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; line : formation; methods : numerical; quasars : emission lines ID ACTIVE GALACTIC NUCLEI; BROAD EMISSION FEATURES; HIGH-REDSHIFT QUASARS; IRON EMISSION; CHEMICAL EVOLUTION; STAR-FORMATION; QSOS; LINES; SPECTRUM; GALAXY AB The enrichment of Fe relative to alpha-elements such as O and Mg represents a potential means to determine the age of quasars and probe the galaxy formation epoch. To explore how Fe II emission in quasars is linked to physical conditions and abundance, we have constructed an 830 level Fe II model atom and investigated through photoionization calculations how Fe II emission strengths depend on nonabundance factors. We have split Fe II emission into three major wavelength bands, Fe II (UV), Fe II (Opt1), and Fe II (Opt2), and explore how the Fe II (UV)/Mg II, Fe II (UV)/Fe II (Opt1), and Fe II (UV)/Fe II (Opt2) emission ratios depend on hydrogen density and ionizing flux in the broad-line regions (BLRs) of quasars. Our calculations show that (1) similar Fe II (UV)/Mg II ratios can exist over a wide range of physical conditions, (2) the Fe II (UV)/Fe II (Opt1) and Fe II (UV)/Fe II (Opt2) ratios serve to constrain ionizing luminosity and hydrogen density, and (3) flux measurements of Fe ii bands and knowledge of the ionizing flux provide tools to derive distances to BLRs in quasars. To derive all BLR physical parameters with uncertainties, comparisons of our model with observations of a large quasar sample at low redshift (z<1) are desirable. The STIS and NICMOS instruments aboard the Hubble Space Telescope offer the best means to provide such observations. C1 Catholic Univ Amer, Dept Phys, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Lund Univ, Lund Observ, S-22100 Lund, Sweden. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Verner, E (reprint author), Catholic Univ Amer, Dept Phys, Inst Astrophys & Computat Sci, 200 Hannan Hall, Washington, DC 20064 USA. EM kverner@fe2.gsfc.nasa.gov; fredb@iacs.gsfc.nasa.gov; verner15@comcast.net; sveneric.johansson@astro.lu.se; timothy.r.kallman@nasa.gov; theodore.r.gull@nasa.gov RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 28 TC 19 Z9 19 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2004 VL 611 IS 2 BP 780 EP 785 DI 10.1086/422303 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 847NY UT WOS:000223403400013 ER PT J AU Hams, T Barbier, LM Bremerich, M Christian, ER de Nolfo, GA Geier, S Gobel, H Gupta, SK Hof, M Menn, W Mewaldt, RA Mitchell, JW Schindler, SM Simon, M Streitmatter, RE AF Hams, T Barbier, LM Bremerich, M Christian, ER de Nolfo, GA Geier, S Gobel, H Gupta, SK Hof, M Menn, W Mewaldt, RA Mitchell, JW Schindler, SM Simon, M Streitmatter, RE TI Measurement of the abundance of radioactive Be-10 and other light isotopes in cosmic radiation up to 2 GeV nucleon(-1) with the balloon-borne instrument ISOMAX SO ASTROPHYSICAL JOURNAL LA English DT Article DE balloons; cosmic rays; nuclear reactions, nucleosynthesis, abundances ID PARTIAL CROSS-SECTIONS; ATOMIC MASS UNIT; RAY NUCLEI; VOYAGER MEASUREMENTS; AGE; BORON; BERYLLIUM; GALAXY; PERFORMANCE; PROPAGATION AB The Isotope Magnet Experiment (ISOMAX), a balloon-borne superconducting magnet spectrometer, was designed to measure the isotopic composition of the light isotopes (3less than or equal toZless than or equal to8) of cosmic radiation up to 4 GeV nucleon(-1) with a mass resolution of better than 0.25 amu by using the velocity versus rigidity technique. To achieve this stringent mass resolution, ISOMAX was composed of three major detector systems: a magnetic rigidity spectrometer with a precision drift chamber tracker in conjunction with a three-layer time-of-flight system, and two silica-aerogel Cerenkov counters for velocity determination. A special emphasis of the ISOMAX program was the accurate measurement of radioactive Be-10 with respect to its stable neighbor isotope Be-9, which provides important constraints on the age of cosmic rays in the Galaxy. ISOMAX had its first balloon flight on 1998 August 4-5 from Lynn Lake, Manitoba, Canada. Thirteen hours of data were recorded during this flight at a residual atmosphere of less than 5 g cm(-2). The isotopic ratio at the top of the atmosphere for Be-10/Be-9 was measured to be 0.195+/-0.036 (statistical) +/- 0.039 (systematic) between 0.26 and 1.03 GeV nucleon(-1) and 0.317+/-0.109 (statistical) +/-0.042 (systematic) between 1.13 and 2.03 GeV nucleon(-1). This is the first measurement of its kind above 1 GeV nucleon(-1). ISOMAX results tend to be higher than predictions from current propagation models. In addition to the beryllium results, we report the isotopic ratios of neighboring lithium and boron in the energy range of the time-of-flight system (up to similar to1 GeV nucleon(-1)). The lithium and boron ratios agree well with existing data and model predictions at similar energies. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Siegen, Fachbereich Phys, D-57068 Siegen, Germany. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. Tata Inst Fundamental Res, HECR Grp, Bombay 400005, Maharashtra, India. RP Hams, T (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. EM hams@milkyway.gsfc.nasa.gov RI de Nolfo, Georgia/E-1500-2012; Christian, Eric/D-4974-2012 OI Christian, Eric/0000-0003-2134-3937 NR 52 TC 30 Z9 30 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2004 VL 611 IS 2 BP 892 EP 905 DI 10.1086/422384 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 847NY UT WOS:000223403400023 ER PT J AU Shelton, RL Kuntz, KD Petre, R AF Shelton, RL Kuntz, KD Petre, R TI Chandra observations and models of the mixed-morphology supernova remnant W44: Global trends SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : individual (W44); supernova remnants; X-rays : ISM ID OPTICALLY THIN PLASMAS; FORMED DENSE SHELL; PULSAR WIND NEBULA; X-RAY; THERMAL CONDUCTION; ASCA OBSERVATIONS; GALACTIC PLANE; HOT INTERIOR; PSR B1853+01; CYGNUS LOOP AB We report on the Chandra observations of the archetypical mixed-morphology (or thermal composite) supernova remnant W44. As with other mixed-morphology remnants, W44's projected center is bright in thermal X-rays. It has an obvious radio shell but no discernible X-ray shell. In addition, X-ray-bright knots dot W44's image. The spectral analysis of the Chandra data shows that the remnant's hot bright projected center is metal-rich and that the bright knots are regions of comparatively elevated elemental abundances. Neon is among the affected elements, suggesting that ejecta contributes to the abundance trends. Furthermore, some of the emitting iron atoms appear to be underionized with respect to the other ions, providing the first potential X-ray evidence for dust destruction in a supernova remnant. We use the Chandra data to test the following explanations for W44's X-ray-bright center: (1) entropy mixing due to bulk mixing or thermal conduction, (2) evaporation of swept-up clouds, and (3) a metallicity gradient, possibly due to dust destruction and ejecta enrichment. In these tests, we assume that the remnant has evolved beyond the adiabatic evolutionary stage, which explains the X-ray dimness of the shell. The entropy-mixed model spectrum was tested against the Chandra spectrum for the remnant's projected center and found to be a good match. The evaporating-cloud model was constrained by the finding that the ionization parameters of the bright knots are similar to those of the surrounding regions. While both the entropy-mixed and the evaporating-cloud models are known to predict centrally bright-X-ray morphologies, their predictions fall short of the observed brightness gradient. The resulting brightness gap can be largely filled in by emission from the extra metals in and near the remnant's projected center. The preponderance of evidence ( including that drawn from other studies) suggests that W44's remarkable morphology can be attributed to dust destruction and ejecta enrichment within an entropy-mixed, adiabatic-phase supernova remnant. The Chandra data prompt a new question-by what astrophysical mechanisms are the metals distributed so inhomogeneously in the supernova remnant. C1 Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. Univ Georgia, Ctr Simulat Phys, Athens, GA 30602 USA. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Shelton, RL (reprint author), Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. EM rls@hal.physast.uga.edu; kuntz@milkyway.gsfc.nasa.gov; rob@milkyway.gsfc.nasa.gov NR 50 TC 26 Z9 27 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2004 VL 611 IS 2 BP 906 EP 918 DI 10.1086/422352 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 847NY UT WOS:000223403400024 ER PT J AU van Diedenhoven, B Peeters, E Van Kerckhoven, C Hony, S Hudgins, DM Allamandola, LJ Tielens, AGGM AF van Diedenhoven, B Peeters, E Van Kerckhoven, C Hony, S Hudgins, DM Allamandola, LJ Tielens, AGGM TI The profiles of the 3-12 micron polycyclic aromatic hydrocarbon features SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrochemistry; infrared : ISM; ISM : lines and bands; ISM : molecules; line : identification ID INFRARED-EMISSION BANDS; RED RECTANGLE; PAH MOLECULES; HII-REGIONS; MU-M; SPECTROSCOPY; INTERSTELLAR; SPECTRA; ISO; MECHANISM AB We present spectra of the 3.3 mum and 11.2 mum polycyclic aromatic hydrocarbon (PAH) features of a large number of stellar sources, planetary nebulae, reflection nebulae, H II regions, and galaxies, obtained with Infrared Space Observatory Short Wavelength Spectrometer. Clear variations are present in the profiles of these features. Most of the sources show a symmetric 3.3 mum feature peaking at similar to3.290 mum, while only very few show an asymmetric 3.3 mum feature peaking at a slightly longer wavelength. The profiles of the 11.2 mum feature are distinctly asymmetric. The majority of the sources has a 11.2 mum feature peaking between 11.20 and 11.24 mum, with a very steep blue rise and a low tail-to-top ratio. A few sources show a 11.2 mum feature with a peak position of similar to11.25 mum, a less steep blue rise, and a high tail-to-top ratio. The sources are classified independently on the basis of the 3.3 and 11.2 mum feature profiles and peak positions. Correlations between these classes and those based on the 6-9 mum features (Peeters et al.) are found. In particular, sources with the most common profiles in the 6-9 mum region also show the most common 3.3 and 11.2 mum feature profiles. However, the uncommon profiles do not correlate with each other. Also, these classifications depend on the type of object. In general, H II regions, nonisolated Herbig AeBe stars and young stellar objects show the same profiles for all 3-12 mum features. Many planetary nebulae and post-asymptotic giant branch stars show uncommon feature profiles. The three galaxies in our sample show the same profiles as the H II regions for all but the 11.2 mum feature, being similar to that of evolved stars. The observed pronounced contrast in the spectral variations for the CH modes (3.3 and 11.2 mum bands) versus the CC modes (6.2, 7.7, and 8.6 mum bands) is striking: the peak wavelengths of the features attributed to CC modes vary by similar to15-80 cm(-1), while for the CH modes the variations are similar to4-6.5 cm(-1). We summarize existing laboratory data and theoretical calculations of the modes emitting in the 3-12 mum region of PAH molecules and complexes. In contrast to the 6.2 and 7.7 mum components, which are attributed to PAH cations, the 3.3 mum feature appears to originate in neutral and/or negatively charged PAHs. We attribute the variations in peak position and profile of these IR emission features to the composition of the PAH family. The variations in FWHM of the 3.3 mum feature remains an enigma, while those of the 11.2 mum can be explained by anharmonicity and molecular structure. The possible origin of the observed contrast in profile variations between the CH modes and the CC modes is highlighted. C1 Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. Univ Groningen, Natl Inst Space Res, SRON, NL-9700 AV Groningen, Netherlands. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Katholieke Univ Leuven, Inst Sterrenkunde, B-3100 Heverlee, Belgium. European Space Agcy, Estec, RSSD, NL-2200 AG Noordwijk, Netherlands. RP Univ Groningen, Kapteyn Astron Inst, POB 800, NL-9700 AV Groningen, Netherlands. EM epeeters@mail.arc.nasa.gov RI van Diedenhoven, Bastiaan/A-2002-2013; OI van Diedenhoven, Bastiaan/0000-0001-5622-8619 NR 60 TC 145 Z9 145 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 AUG 20 PY 2004 VL 611 IS 2 BP 928 EP 939 DI 10.1086/422404 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 847NY UT WOS:000223403400026 ER PT J AU Simon, T Andrews, SM Rayner, JT Drake, SA AF Simon, T Andrews, SM Rayner, JT Drake, SA TI X-ray and infrared observations of embedded young stars in L1630 SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : stars; ISM : Herbig-Haro objects; ISM : individual (L1630, HH 24, 26); stars : individual (SSV 61, SSV 63); stars : pre-main-sequence; X-rays : stars ID HERBIG-HARO OBJECTS; T-TAURI STARS; HIGH-RESOLUTION SPECTROSCOPY; RS-CANUM-VENATICORUM; EMISSION-LINE STARS; MAIN-SEQUENCE STARS; CLASS 0 PROTOSTAR; STELLAR OBJECTS; MOLECULAR CLOUD; HH 24-26 AB The HH 24-26 star-forming region in the Lynds 1630 (L1630) dark cloud in Orion contains a remarkable collection of rare Class 0 and Class I protostars, collimated molecular and ionized jets, and a luminous but spatially unresolved ASCA X-ray source. To study the X-ray properties of the embedded protostar population of that region, we have obtained a deep X-ray image with the ACIS-S camera on board the Chandra X-Ray Observatory. A number of Halpha emission-line objects were detected in the areas surrounding HH 24-26, of which the weak-line T Tauri star SSV 61 was the brightest source, at a steady luminosity of L-X(0.3-10 keV)=10(31.9) ergs s(-1). Two Class I protostars aligned with optical jets in HH 24, SSV 63E, and SSV 63W, were also detected, as was the continuum radio source SSV 63NE, which is very likely an extreme Class I or Class 0 object. We observed no X rays from the Class 0 protostars HH 24-MMS and HH 25-MMS, nor any from regions of the cloud bounded by HH 25 and HH 26, at a 2 sigma upper limit of L(X)similar to10(30.0) ergs s(-1). HH 26-IR, the Class I object thought to be the origin of the HH 26 flow, was not detected. Near-infrared spectroscopy obtained at the NASA IRTF reveals 3 mum ice bands in the spectra of SSV 59, 63E, 63W, and HH 26-IR, and 2.3 mum CO overtone absorption bands for SSV 61. SSV 60, which lies astride one end of the great arc of nebulosity forming HH 25, exhibits a deep infrared ice band and CO absorption but is not an X-ray source and is most likely a distant background giant of late spectral type. C1 NASA, Goddard Space Flight Ctr, HEASARC, Greenbelt, MD 20771 USA. RP Simon, T (reprint author), NASA, Goddard Space Flight Ctr, HEASARC, Greenbelt, MD 20771 USA. NR 93 TC 15 Z9 15 U1 0 U2 0 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 AUG 20 PY 2004 VL 611 IS 2 BP 940 EP 951 DI 10.1086/422187 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 847NY UT WOS:000223403400027 ER PT J AU Gehrels, N Chincarini, G Giommi, P Mason, KO Nousek, JA Wells, AA White, NE Barthelmy, SD Burrows, DN Cominsky, LR Hurley, KC Marshall, FE Meszaros, P Roming, PWA Angelini, L Barbier, LM Belloni, T Campana, S Caraveo, PA Chester, MM Citterio, O Cline, TL Cropper, MS Cummings, JR Dean, AJ Feigelson, ED Fenimore, EE Frail, DA Fruchter, AS Garmire, GP Gendreau, K Ghisellini, G Greiner, J Hill, JE Hunsberger, SD Krimm, HA Kulkarni, SR Kumar, P Lebrun, F Lloyd-Ronning, NM Markwardt, CB Mattson, BJ Mushotzky, RF Norris, JP Osborne, J Paczynski, B Palmer, DM Park, HS Parsons, AM Paul, J Rees, MJ Reynolds, CS Rhoads, JE Sasseen, TP Schaefer, BE Short, AT Smale, AP Smith, IA Stella, L Tagliaferri, G Takahashi, T Tashiro, M Townsley, LK Tueller, J Turner, MJL Vietri, M Voges, W Ward, MJ Willingale, R Zerbi, FM Zhang, WW AF Gehrels, N Chincarini, G Giommi, P Mason, KO Nousek, JA Wells, AA White, NE Barthelmy, SD Burrows, DN Cominsky, LR Hurley, KC Marshall, FE Meszaros, P Roming, PWA Angelini, L Barbier, LM Belloni, T Campana, S Caraveo, PA Chester, MM Citterio, O Cline, TL Cropper, MS Cummings, JR Dean, AJ Feigelson, ED Fenimore, EE Frail, DA Fruchter, AS Garmire, GP Gendreau, K Ghisellini, G Greiner, J Hill, JE Hunsberger, SD Krimm, HA Kulkarni, SR Kumar, P Lebrun, F Lloyd-Ronning, NM Markwardt, CB Mattson, BJ Mushotzky, RF Norris, JP Osborne, J Paczynski, B Palmer, DM Park, HS Parsons, AM Paul, J Rees, MJ Reynolds, CS Rhoads, JE Sasseen, TP Schaefer, BE Short, AT Smale, AP Smith, IA Stella, L Tagliaferri, G Takahashi, T Tashiro, M Townsley, LK Tueller, J Turner, MJL Vietri, M Voges, W Ward, MJ Willingale, R Zerbi, FM Zhang, WW TI The Swift gamma-ray burst mission SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; space vehicles : instruments; telescopes ID OPTICAL/UV MONITOR TELESCOPE; STAR-FORMATION HISTORY; HUBBLE DEEP FIELD; 28 FEBRUARY 1997; JET-X TELESCOPE; INTERGALACTIC MEDIUM; HOST GALAXIES; ERROR BOX; SUPERNOVA; AFTERGLOW AB The Swift mission, scheduled for launch in 2004, is a multiwavelength observatory for gamma-ray burst (GRB) astronomy. It is a first-of-its-kind autonomous rapid-slewing satellite for transient astronomy and pioneers the way for future rapid-reaction and multiwavelength missions. It will be far more powerful than any previous GRB mission, observing more than 100 bursts yr(-1) and performing detailed X-ray and UV/optical afterglow observations spanning timescales from 1 minute to several days after the burst. The objectives are to (1) determine the origin of GRBs, (2) classify GRBs and search for new types, (3) study the interaction of the ultrarelativistic outflows of GRBs with their surrounding medium, and (4) use GRBs to study the early universe out to z>10. The mission is being developed by a NASA-led international collaboration. It will carry three instruments: a new-generation wide-field gamma-ray (15-150 keV) detector that will detect bursts, calculate 1'-4' positions, and trigger autonomous spacecraft slews; a narrow-field X-ray telescope that will give 5" positions and perform spectroscopy in the 0.2-10 keV band; and a narrow-field UV/optical telescope that will operate in the 170-600 nm band and provide 0".3 positions and optical finding charts. Redshift determinations will be made for most bursts. In addition to the primary GRB science, the mission will perform a hard X-ray survey to a sensitivity of similar to1 mcrab (similar to2x10(-11) ergs cm(-2) s(-1) in the 15-150 keV band), more than an order of magnitude better than HEAO 1 A-4. A flexible data and operations system will allow rapid follow-up observations of all types of high-energy transients, with rapid data downlink and uplink available through the NASA TDRSS system. Swift transient data will be rapidly distributed to the astronomical community, and all interested observers are encouraged to participate in follow-up measurements. A Guest Investigator program for the mission will provide funding for community involvement. Innovations from the Swift program applicable to the future include (1) a large-area gamma-ray detector using the new CdZnTe detectors, (2) an autonomous rapid-slewing spacecraft, (3) a multiwavelength payload combining optical, X-ray, and gamma-ray instruments, (4) an observing program coordinated with other ground-based and space-based observatories, and (5) immediate multiwavelength data flow to the community. The mission is currently funded for 2 yr of operations, and the spacecraft will have a lifetime to orbital decay of similar to8 yr. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Osserv Astron Brera, I-20121 Milan, Italy. Univ Milano Bicocca, Dipartimento Fis, I-20133 Milan, Italy. Agenzia Spaziale Italiana, Sci Data Ctr, I-00198 Rome, Italy. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Leicester, Space Res Ctr, Leicester LE1 7RH, Leics, England. Sonoma State Univ, Dept Phys & Astron, Rohnert Pk, CA 94928 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. CNR, Ist Astrofis Spaziale & Fis Cosm, I-20133 Milan, Italy. CNR, Washington, DC 20418 USA. Univ Southampton, Dept Phys & Astron, Southampton S017 1BJ, Hants, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Max Planck Inst Extraterr Phys, D-85748 Garching, Germany. CALTECH, Pasadena, CA 91125 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. CEA, DSM, DAPNIA, SAP,Ctr Etud Saclay, F-91191 Gif Sur Yvette, France. Univ Toronto, McClennan Labs, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Commun EER L3, Chantilly, VA USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Princeton Univ Observ, Princeton, NJ 08544 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Osserv Astron Roma, I-00040 Rome, Italy. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 113, Japan. Saitama Univ, Dept Phys, Sakura, Saitama, Japan. Univ Florence, Osservatorio Astrofis Arcetri, I-50125 Florence, Italy. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI White, Nicholas/B-6428-2012; Gehrels, Neil/D-2971-2012; Tueller, Jack/D-5334-2012; Barthelmy, Scott/D-2943-2012; Parsons, Ann/I-6604-2012; Tashiro, Makoto/J-4562-2012; OI White, Nicholas/0000-0003-3853-3462; Campana, Sergio/0000-0001-6278-1576; Ghisellini, Gabriele/0000-0002-0037-1974; giommi, paolo/0000-0002-2265-5003; Zerbi, Filippo Maria/0000-0002-9996-973X; Caraveo, Patrizia/0000-0003-2478-8018; Tagliaferri, Gianpiero/0000-0003-0121-0723 NR 61 TC 1824 Z9 1836 U1 17 U2 75 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 AUG 20 PY 2004 VL 611 IS 2 BP 1005 EP 1020 DI 10.1086/422091 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 847NY UT WOS:000223403400032 ER PT J AU Desai, MI Mason, GM Wiedenbeck, ME Cohen, CMS Mazur, JE Dwyer, JR Gold, RE Krimigis, SM Hu, Q Smith, CW Skoug, RM AF Desai, MI Mason, GM Wiedenbeck, ME Cohen, CMS Mazur, JE Dwyer, JR Gold, RE Krimigis, SM Hu, Q Smith, CW Skoug, RM TI Spectral properties of heavy ions associated with the passage of interplanetary shocks at 1 AU SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; interplanetary medium; shock waves ID ENERGETIC PARTICLE EVENTS; ADVANCED COMPOSITION EXPLORER; EARTHS BOW SHOCK; COROTATING INTERACTION REGIONS; SOLAR ISOTOPE SPECTROMETER; CHARGE-STATE DISTRIBUTION; RANKINE-HUGONIOT PROBLEM; EJECTION-DRIVEN SHOCKS; TEMPORAL EVOLUTION; TRAVELING SHOCKS AB We have surveyed the energy spectra of similar to0.1-100 MeV nucleon(-1) C, O, and Fe nuclei associated with the passage of 72 interplanetary (IP) shocks observed on board the ACE spacecraft during the period 1997 October-2002 October. Our main results are as follows: (1) The spectral fit parameters are independent of the local shock properties. (2) About 7% of the events exhibit increasing Fe/O ratios with energy; the remaining events have Fe/O ratios that either remain constant or decrease with energy. (3) The Fe/O ratio in the shock-associated particles is typically similar to30% lower than in the ambient population. (4) The fractionation pattern of the elemental abundances, the O spectra, and the energy-dependence of Fe/O at the IP shocks are remarkably similar to those of the ambient interplanetary suprathermal ion population. We suggest that the IP shocks studied here reaccelerate energetic particle seed spectra composed of ions from impulsive and gradual solar energetic particle events by systematic rigidity-dependent mechanisms in which higher rigidity ions are accelerated less efficiently than lower rigidity ions. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. Aerosp Corp, El Segundo, CA 90245 USA. Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Calif Riverside, Inst Geophys & Planetary Phys, Riverside, CA 92521 USA. Univ New Hampshire, Inst Earth Oceans & Space, Durham, NH 03824 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. RP Univ Maryland, Dept Phys, College Pk, MD 20742 USA. NR 76 TC 65 Z9 67 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2004 VL 611 IS 2 BP 1156 EP 1174 DI 10.1086/422211 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 847NY UT WOS:000223403400048 ER PT J AU Cami, J Salama, F Jimenez-Vicente, J Galazutdinov, GA Krelowski, J AF Cami, J Salama, F Jimenez-Vicente, J Galazutdinov, GA Krelowski, J TI The rotational excitation temperature of the lambda 6614 diffuse interstellar band carrier SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : lines and bands; ISM : molecules ID POLYCYCLIC AROMATIC-HYDROCARBONS; HIGH-RESOLUTION PROFILES; GAS-PHASE; ABSORPTION; ANGSTROM; CLOUDS; SPECTROSCOPY; SPECTRUM; CONTOURS AB Analysis of high spectral resolution observations of the lambda6614 diffuse interstellar band (DIB) line profile shows systematic variations in the positions of the peaks in the substructure of the profile. These variations-shown here for the first time-can be understood most naturally in the framework of rotational contours of large molecules, where the variations are caused by changes in the rotational excitation temperature. We show that the rotational excitation temperature for the DIB carrier is likely significantly lower than the gas kinetic temperature-indicating that for this particular DIB carrier angular momentum buildup is not very efficient. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Granada, Fac Ciencias, Dept Fis Teor & Cosmos, E-18071 Granada, Spain. Korea Astron Observ, Opt Astron Div, Taejon 305348, South Korea. Special Astrophys Observ, Nizhnii Arkhyz 369167, Russia. Nicholas Copernicus Univ, Ctr Astron, PL-87100 Torun, Poland. RP Cami, J (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. EM jcami@mail.arc.nasa.gov; fsalama@mail.arc.nasa.gov; jjimenez@ugr.es; gala@boao.re.kr; jacek.krelowski@astri.uni.torun.pl RI Jimenez-Vicente, Jorge/K-1209-2014; Salama, Farid/A-8787-2009 OI Jimenez-Vicente, Jorge/0000-0001-7798-3453; Salama, Farid/0000-0002-6064-4401 NR 30 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 AUG 20 PY 2004 VL 611 IS 2 BP L113 EP L116 DI 10.1086/423991 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 847OA UT WOS:000223403600012 ER PT J AU Dwek, E AF Dwek, E TI Galactic center extinction: Evidence of metallic needles in the general interstellar medium SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; Galaxy : center ID MICROWAVE BACKGROUND-RADIATION; INFRARED-EMISSION; DUST; SUPERNOVAE; IRON AB The extinction curve derived from Infrared Space Observatory mid-infrared observations of the Galactic center (GC) exhibits a surprisingly flat behavior in the similar to3-8 mum region, contrary to the deep minimum expected from standard interstellar dust models consisting of bare silicate and graphite dust particles. We show that this extinction is likely caused by the presence of metallic needles in the interstellar medium (ISM) toward the GC. If the needles contribute only to the 3-8 mum extinction, they must have a long-wavelength cutoff at similar to8 mum and therefore a typical length over radius ratio of similar to600, smaller than the similar to3x10(3) aspect ratio determined for the needles in Cas A. Homogeneously distributed throughout the ISM, they comprise only a minor mass fraction of the ISM, with a needle-to-H mass ratio of similar to5x10(-6), which is equivalent to 0.14% of the silicate dust mass. Their total ISM abundance then can be readily explained by the combined production in supernovae and O-rich stellar outflows. The GC observations show that metallic needles, in spite of their low abundance or nonuniform distribution, can be the dominant source of opacity in the 3-8 mum wavelength region. However, expelled into the intergalactic medium, their abundance is too low to cause any dimming of cosmological sources, and their length is too short to make them a significant source of submillimeter emission. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Dwek, E (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 680, Greenbelt, MD 20771 USA. EM eli.dwek@nasa.gov NR 22 TC 16 Z9 16 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2004 VL 611 IS 2 BP L109 EP L112 DI 10.1086/423893 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 847OA UT WOS:000223403600011 ER PT J AU Xu, YH Sun, JJ Mathew, G Jeevarajan, AS Anderson, MM AF Xu, YH Sun, JJ Mathew, G Jeevarajan, AS Anderson, MM TI Continuous glucose monitoring and control in a rotating wall perfused bioreactor SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE glucose control; in-line glucose sensor; rotating; bioreactor; BHK-21 cells; cell culture ID CELL-CULTURES; BHK CELLS; SIMULATED MICROGRAVITY; MAMMALIAN-CELLS; SYSTEM; LACTATE; SENSOR; SERUM AB A glucose control system consisting of a single in-line glucose sensor, concentrated glucose solution, and computer hardware and software were developed. The system was applied to continuously control glucose concentrations of a perfusion medium in a rotating wall perfused vessel (RWPV) bioreactor culturing BHK-21 cells. The custom-made glucose sensor was based on a hydrogen peroxide electrode. The sensor continuously and accurately measured the glucose concentration of GTSF-2 medium in the RWPV bioreactor during cell culture. Three sets of two-point calibrations were applied to the glucose sensor during the 55-day cell culture. The system first controlled the glucose concentration in perfusing medium between 4.2 and 5.6 mM for 36 days and then at different glucose levels for 19 days. A stock solution with a high glucose concentration (266 mM) was used as the glucose injection solution. The standard error of prediction (SEP) for glucose measurement by the sensor, compared to measurement by the Beckman glucose analyzer, was +/-0.4 mM for 55 days. (C) 2004 Wiley Periodical, Inc. C1 NASA, Lyndon B Johnson Space Ctr, Biol Syst Off, Houston, TX 77058 USA. Wyle Labs Life Sci Syst & Serv, Houston, TX 77058 USA. RP Jeevarajan, AS (reprint author), NASA, Lyndon B Johnson Space Ctr, Biol Syst Off, Mail Code SJ,2101 NASA Rd 1, Houston, TX 77058 USA. EM antony.s.jeevarajan@nasa.gov NR 18 TC 7 Z9 7 U1 0 U2 6 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD AUG 20 PY 2004 VL 87 IS 4 BP 473 EP 477 DI 10.1002/bit.20141 PG 5 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 843IR UT WOS:000223072500005 PM 15286984 ER PT J AU Cargnoni, F Nishibori, E Rabiller, P Bertini, L Snyder, GJ Christensen, M Gatti, C Iversen, BB AF Cargnoni, F Nishibori, E Rabiller, P Bertini, L Snyder, GJ Christensen, M Gatti, C Iversen, BB TI Interstitial Zn atoms do the trick in thermoelectric zinc antimonide, Zn4Sb3: A combined maximum entropy method X-ray electron density and ab initio electronic structure study SO CHEMISTRY-A EUROPEAN JOURNAL LA English DT Article DE ab initio calculations; antimony; electron density topology; electronic structure; maximum entropy method; thermoelectric materials; zinc ID CHARGE-DENSITY; DIFFRACTION; METALLOFULLERENE; PHASES AB The experimental electron density of the high-performance thermoelectric material Zn4Sb3 has been determined by maximum entropy (MEM) analysis of short-wavelength synchrotron powder diffraction data. These data are found to be more accurate than conventional single-crystal data due to the reduction of common systematic errors, such as absorption, extinction and anomalous scattering. Analysis of the MEM electron density directly reveals interstitial Zn atoms and a partially occupied main Zn site. Two types of Sb atoms are observed: a free spherical ion (Sb3-) and Sb-2(4-) dimers. Analysis of the MEM electron density also reveals possible Sb disorder along the c axis. The disorder, defects and vacancies are all features that contribute to the drastic reduction of the thermal conductivity of the material. Topological analysis of the thermally smeared MEM density has been carried out. Starting with the X-ray structure ab initio computational methods have been used to deconvolute structural information from the space-time data averaging inherent to the XRD experiment. The analysis reveals how interstitial Zn atoms and vacancies affect the electronic structure and transport properties of beta-Zn4Sb3. The structure consists of an ideal A(12)Sb(10) framework in which point defects are distributed. We propose that the material is a 0.184:0.420:0.396 mixture of A(12)Sb(10), A(11)BCSb(10) and A(10)BCDSb(10) cells, in which A, B, C and D are the four Zn sites in the X-ray structure. Given the similar density of states (DOS) of the A(12)Sb(10), A(11)BCSb(10) and A(10)BCDSb(10) cells, one may electronically model the defective stoichiometry of the real system either by n-doping the 12-Zn atom cell or by p-doping the two 13-Zn atom cells. This leads to similar calculated Seebeck coefficients for the A(12)Sb(10), A(11)BCSb(10) and A(10)BCDSb(10) cells (115.0, 123.0 and 110.3 muVK(-1) at T = 670 K). The model system is therefore a p-doped semiconductor as found experimentally. The effect is dramatic if these cells are doped differently with respect to the experimental electron count. Thus, 0.33 extra electrons supplied to either kind of cell would increase the Seebeck coefficient to about 260 muVK(-1). Additional electrons would also lower sigma, so the resulting effect on the thermoelectric figure of merit of Zn4Sb3 challenges further experimental work. C1 Aarhus Univ, Dept Chem, DK-8000 Aarhus C, Denmark. Nagoya Univ, Dept Appl Phys, Nagoya, Aichi 4648603, Japan. Univ Rennes 1, CNRS, UMR 6626, F-35042 Rennes, France. Jet Prop Lab, Pasadena, CA 91109 USA. CNR, ISTM, I-20133 Milan, Italy. RP Gatti, C (reprint author), Aarhus Univ, Dept Chem, Langelandsgade 140, DK-8000 Aarhus C, Denmark. EM c.gatti@istm.cnr.it; bo@chem.au.dk RI Gatti, Carlo/B-7410-2009; Snyder, G. Jeffrey/E-4453-2011; RABILLER, Philippe/O-1623-2014; Cargnoni, Fausto/O-8933-2014; Snyder, G/I-2263-2015; OI Gatti, Carlo/0000-0002-0047-1596; Snyder, G. Jeffrey/0000-0003-1414-8682; BERTINI, LUCA/0000-0003-3402-0846 NR 33 TC 100 Z9 100 U1 4 U2 41 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0947-6539 J9 CHEM-EUR J JI Chem.-Eur. J. PD AUG 20 PY 2004 VL 10 IS 16 BP 3861 EP 3870 DI 10.1002/chem.200400327 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 850EG UT WOS:000223593400002 PM 15317052 ER PT J AU Williams, E Chan, T Boccippio, D AF Williams, E Chan, T Boccippio, D TI Islands as miniature continents: Another look at the land-ocean lightning contrast SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosols; lightning; islands ID GLOBAL DISTRIBUTION; PHYSICAL ORIGIN AB [1] Numerous observations substantiate a pronounced contrast in lightning activity between continents and oceans. The traditional explanation for continental dominance is based on a contrast in thermal properties of land and sea. A more recent idea is based on the contrast in boundary layer aerosol concentration between land and sea. This study makes use of islands as miniature continents of varying area to distinguish between these two hypotheses. Scaling law analysis is used to predict transitional island areas for the two hypotheses. NASA Tropical Rainfall Measuring Mission satellite observations provide a uniform data set on island activity. The island area dependences of lightning activity are more consistent with the thermal hypothesis than the aerosol hypothesis, but this conclusion must be tempered with the extreme simplification of the theoretical predictions. C1 MIT, Parsons Lab, Dept Civil & Environm Engn, Cambridge, MA 02139 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35805 USA. RP Williams, E (reprint author), MIT, Parsons Lab, Dept Civil & Environm Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM earlew@ll.mit.edu; twigchan@mit.edu; dennis.boccippio@msfc.nasa.gov NR 17 TC 40 Z9 42 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 2004 VL 109 IS D16 AR D16206 DI 10.1029/2003JD003833 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 849NU UT WOS:000223546300001 ER PT J AU Li, JZ Ning, CZ AF Li, JZ Ning, CZ TI Induced transparency by intersubband plasmon coupling in a quantum well SO PHYSICAL REVIEW LETTERS LA English DT Article ID COLLECTIVE EXCITATIONS; HETEROSTRUCTURES; INTRASUBBAND; DISPERSION; ELECTRONS; PHONONS; SYSTEMS AB We study coupling of two intersubband plasmons associated with dipole-allowed cascading transitions in a quantum well. We show that the coupling can lead to the disappearance of the lower-energy resonance accompanied by an anticrossing behavior. Such coupling induced anomalies are of collective and resonant nature and provide the first example of Coulomb interaction induced transparency. Our numerical results from a microscopic theory are confirmed by an analytical model. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Li, JZ (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, MAil Stop N229-1, Moffett Field, CA 94035 USA. EM jnli@mail.arc.nasa.gov; cning@mail.arc.nasa.gov RI Ning, C. Z./D-4699-2009 OI Ning, C. Z./0000-0003-4583-8889 NR 24 TC 14 Z9 15 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 20 PY 2004 VL 93 IS 8 AR 087402 DI 10.1103/PhysRevLett.93.087402 PG 4 WC Physics, Multidisciplinary SC Physics GA 848MS UT WOS:000223472400067 PM 15447224 ER PT J AU Koster, RD Dirmeyer, PA Guo, ZC Bonan, G Chan, E Cox, P Gordon, CT Kanae, S Kowalczyk, E Lawrence, D Liu, P Lu, CH Malyshev, S McAvaney, B Mitchell, K Mocko, D Oki, T Oleson, K Pitman, A Sud, YC Taylor, CM Verseghy, D Vasic, R Xue, YK Yamada, T AF Koster, RD Dirmeyer, PA Guo, ZC Bonan, G Chan, E Cox, P Gordon, CT Kanae, S Kowalczyk, E Lawrence, D Liu, P Lu, CH Malyshev, S McAvaney, B Mitchell, K Mocko, D Oki, T Oleson, K Pitman, A Sud, YC Taylor, CM Verseghy, D Vasic, R Xue, YK Yamada, T CA GLACE Team TI Regions of strong coupling between soil moisture and precipitation SO SCIENCE LA English DT Article ID CLIMATE; PREDICTABILITY; VARIABILITY; TEMPERATURE; PREDICTION; SIMULATION; RAINFALL AB Previous estimates of land-atmosphere interaction (the impact of soil moisture on precipitation) have been limited by a lack of observational data and by the model dependence of computational estimates. To counter the second limitation, a dozen climate-modeling groups have recently performed the same highly controlled numerical experiment as part of a coordinated comparison project. This allows a multimodel estimation of the regions on Earth where precipitation is affected by soil moisture anomalies during Northern Hemisphere summer. Potential bene its of this estimation may include improved seasonal rainfall forecasts. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ctr Ocean Land Atmosphere Studies, Calverton, MD 20705 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Meteorol Serv Canada, Toronto, ON M34 5T4, Canada. Hadley Ctr Climate Predict & Res, Exeter EX1 3PB, Devon, England. Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Res Inst Human & Nat, Kyoto 6020878, Japan. CSIRO Atmospher Res, Aspendale, Vic 3195, Australia. Univ Reading, Reading RG6 6BB, Berks, England. Sci Applicat Int Corp, Beltsville, MD 20705 USA. Natl Ctr Environm Predict, Camp Springs, MD 20746 USA. Princeton Univ, Princeton, NJ 08544 USA. Bur Meteorol Res Ctr, Melbourne, Vic 3001, Australia. Univ Tokyo, Tokyo 1538505, Japan. Macquarie Univ, N Ryde, NSW 2109, Australia. Ctr Ecol & Hydrol, Wallingford OX10 8BB, Oxon, England. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM randal.d.koster@nasa.gov RI Oleson, Keith/A-9328-2008; Oki, Taikan/E-5778-2010; Pitman, Andrew/A-7353-2011; Lawrence, David/C-4026-2011; Koster, Randal/F-5881-2012; Taylor, Chris/K-2319-2012; Kanae, Shinjiro/E-5606-2010; Dirmeyer, Paul/B-6553-2016; Cox, Peter/B-3299-2012 OI Oki, Taikan/0000-0003-4067-4678; Pitman, Andrew/0000-0003-0604-3274; Lawrence, David/0000-0002-2968-3023; Koster, Randal/0000-0001-6418-6383; Taylor, Chris/0000-0002-0120-3198; Kanae, Shinjiro/0000-0002-3176-4957; Dirmeyer, Paul/0000-0003-3158-1752; NR 21 TC 1058 Z9 1108 U1 25 U2 252 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD AUG 20 PY 2004 VL 305 IS 5687 BP 1138 EP 1140 DI 10.1126/science.1100217 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 849RD UT WOS:000223557400043 PM 15326351 ER PT J AU Lakew, B Brasunas, JC Aslam, S Pugel, DE AF Lakew, B Brasunas, JC Aslam, S Pugel, DE TI High-T-c, transition-edge superconducting (TES) bolometer on a monolithic sapphire membrane - construction and performance SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article DE monolithic sapphire membrane; high-T-c superconductor; TES bolometer; far infrared detection ID M THICK SAPPHIRE; FILMS AB Suspended, monolithic, 12 mum thick, low thermal mass r-plane sapphire membranes with predictable thermal isolation have been fabricated for use in the construction of TES bolometers. A thin film of YBa2Cu3O7-partial derivative (YBCO) high temperature superconductor grown epitaxially on one such membrane shows a sharp transition temperature at 90K. Early performance results of a high-T-C TES bolometer fabricated using a monolithic membrane are presented and compared to those of a previous kevlar fiber suspended TES bolometer. Merits of voltage biasing to improve noise and response time are briefly discussed. Monolithic sapphire membranes open the door for the development of 1D and 2D arrays of moderately cooled TES bolometers for far infrared exploration of the outer solar system. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Planetary Syst Branch, Greenbelt, MD 20771 USA. Raytheon Corp, Lanham, MD 20706 USA. RP Lakew, B (reprint author), NASA, Goddard Space Flight Ctr, Planetary Syst Branch, Code 693, Greenbelt, MD 20771 USA. EM brook.lakew-1@nasa.gov RI Aslam, Shahid/D-1099-2012; brasunas, john/I-2798-2013 NR 11 TC 9 Z9 9 U1 0 U2 6 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 AUG 20 PY 2004 VL 114 IS 1 BP 36 EP 40 DI 10.1016/j.sna.2004.02.039 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 845KD UT WOS:000223240400006 ER PT J AU Canuto, VM Howard, A Cheng, Y Miller, RL AF Canuto, VM Howard, A Cheng, Y Miller, RL TI Latitude-dependent vertical mixing and the tropical thermocline in a global OGCM SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OCEAN CIRCULATION; COUPLED GCM; GENERAL-CIRCULATION; INTERNAL WAVES; TURBULENCE; MODEL; HEAT; DIFFUSIVITIES; PACIFIC; ENSO AB In most ocean general circulation models (OGCM), mixing in the pycnocline is treated with a constant background diffusivity. This creates the following problem. To obtain the observed sharp equatorial thermocline, OGCMs must adopt a pycnocline diffusivity ten times smaller than observed at mid-latitudes. The conflict can only be resolved by switching to a spatially variable mixing. In this work we present the GISS mixing model supplemented by Gregg et al.' s [ 2003] finding that the rate of dissipation of internal gravity waves is latitude dependent. We use the new GISS model in a global OGCM and obtain an equatorial thermocline in both the Atlantic and Pacific oceans that is sharper than without the latitude dependence. The model results for the Pacific compare favorably with Kessler's [ 1990] data. The meridional overturning in the Atlantic and the global poleward heat transport are nearly unchanged from the values obtained without latitude dependence. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Math, New York, NY USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA USA. RP Canuto, VM (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM vcanuto@giss.nasa.gov OI Howard, Alan/0000-0002-5423-1600 NR 35 TC 8 Z9 8 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 19 PY 2004 VL 31 IS 16 AR L16305 DI 10.1029/2004GL019891 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 849MZ UT WOS:000223544200002 ER PT J AU Castro, SL Bailey, SG Raffaelle, RP Banger, KK Hepp, AF AF Castro, SL Bailey, SG Raffaelle, RP Banger, KK Hepp, AF TI Synthesis and characterization of colloidal CuInS2 nanoparticles from a molecular single-source precursor SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELEMENTAL SOLVOTHERMAL REACTION; FILM SOLAR-CELLS; THIN-FILM; QUANTUM DOTS; CDSE NANOCRYSTALLITES; CHALCOPYRITE MATERIALS; OPTICAL-PROPERTIES; ROUTE; LUMINESCENCE; NANORODS AB Thermal decomposition of the molecular single-source precursor (PPh3)(2)CuIn(SEt)(4) in the presence of hexanethiol in dioctylphthalate forms colloidal CuInS2 at 200 degreesC. The colloidal solution displays size-dependent quantum confinement behavior in the absorption and photoluminescence spectra. The average size of the nanocrystals can be increased from 2 to 4 nm by raising the reaction temperature from 200 degreesC to 250 degreesC. The nanoparticles are capped with hexanethiol ligands; these ligands can be exchanged with trioctylphosphine oxide or pyridine. The nature of the surface-capping ligands has a significant effect on the photoluminescence emission intensity. Investigation of the effect of synthesis parameters and postsynthesis treatments on the optical properties of the nanocrystals leads to the conclusion that the room-temperature emission originates in donor-acceptor defects. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Photovoltaics & Space Envirom Branch, Cleveland, OH 44135 USA. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. RP Castro, SL (reprint author), NASA, Glenn Res Ctr, Photovoltaics & Space Envirom Branch, Mail Stop 302-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM stephanie.castro@grc.nasa.gov NR 67 TC 269 Z9 276 U1 13 U2 97 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD AUG 19 PY 2004 VL 108 IS 33 BP 12429 EP 12435 DI 10.1021/jp049107p PG 7 WC Chemistry, Physical SC Chemistry GA 846BK UT WOS:000223289500024 ER PT J AU Holman, MJ Kavelaars, JJ Grav, T Gladman, BJ Fraser, WC Milisavljevic, D Nicholson, PD Burns, JA Carruba, V Petit, JM Rousselot, P Mousis, O Marsden, BG Jacobson, RA AF Holman, MJ Kavelaars, JJ Grav, T Gladman, BJ Fraser, WC Milisavljevic, D Nicholson, PD Burns, JA Carruba, V Petit, JM Rousselot, P Mousis, O Marsden, BG Jacobson, RA TI Discovery of five irregular moons of Neptune SO NATURE LA English DT Article ID ASSISTED CAPTURE; GAS-DRAG; SATELLITES; URANUS; INCLINATION; OBJECTS; JUPITER; SEARCH AB Each giant planet of the Solar System has two main types of moons. 'Regular' moons are typically larger satellites with prograde, nearly circular orbits in the equatorial plane of their host planets at distances of several to tens of planetary radii. The 'irregular' satellites (which are typically smaller) have larger orbits with significant eccentricities and inclinations. Despite these common features, Neptune's irregular satellite system, hitherto thought to consist of Triton and Nereid, has appeared unusual. Triton is as large as Pluto and is postulated to have been captured from heliocentric orbit; it traces a circular but retrograde orbit at 14 planetary radii from Neptune. Nereid, which exhibits one of the largest satellite eccentricities, is believed to have been scattered from a regular satellite orbit to its present orbit during Triton's capture(1,2). Here we report the discovery of five irregular moons of Neptune, two with prograde and three with retrograde orbits. These exceedingly faint (apparent red magnitude m(R) = 5 24.2-25.4) moons, with diameters of 30 to 50 km, were presumably captured by Neptune. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Res Council Canada, Victoria, BC V9E ZE7, Canada. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Obervatoire Besancon, F-25010 Besancon, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Holman, MJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM mholman@cfa.harvard.edu RI Carruba, Valerio/H-5529-2012 OI Carruba, Valerio/0000-0003-2786-0740 NR 30 TC 38 Z9 39 U1 1 U2 4 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 19 PY 2004 VL 430 IS 7002 BP 865 EP 867 DI 10.1038/nature02832 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 847DA UT WOS:000223369800034 PM 15318214 ER PT J AU Smith, JG Delozier, DM Connell, JW Watson, KA AF Smith, JG Delozier, DM Connell, JW Watson, KA TI Carbon nanotube-conductive additive-space durable polymer nanocomposite films for electrostatic charge dissipation SO POLYMER LA English DT Article DE low color polyimides; nanocomposites; electrostatic charge mitigation ID DISPERSION AB Thin film membranes of space environmentally stable polymeric materials possessing low color/solar absorptivity (alpha) are of interest for potential applications on Gossamer spacecraft. In addition to these properties, sufficient electrical conductivity is required in order to dissipate electrostatic charge (ESC) build-up brought about by the charged orbital environment. One approach to achieve sufficient electrical conductivity for ESC mitigation is by the incorporation of single-walled carbon nanotubes (SWNTs). However, when SWNTs are dispersed throughout the polymer matrix, the nanocomposite films tend to be significantly darker than the pristine material resulting in a higher alpha. The incorporation of conductive additives in combination with a decreased SWNT loading level is one approach for improving alpha while retaining conductivity. Taken individually, the low loading level of conductive additives and SWNTs was insufficient in achieving the percolation level necessary for electrical conductivity. When added concurrently to the film, conductivity was achieved. The chemistry, physical and mechanical properties of the nanocomposite films will be presented. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. Natl Inst Aerosp, Hampton, VA 23666 USA. RP Smith, JG (reprint author), NASA, Langley Res Ctr, Adv Mat & Proc Branch, Mail Stop 226, Hampton, VA 23681 USA. EM joseph.g.smith@nasa.gov NR 16 TC 59 Z9 59 U1 3 U2 14 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 AUG 19 PY 2004 VL 45 IS 18 BP 6133 EP 6142 DI 10.1016/j.polymer.2004.07.004 PG 10 WC Polymer Science SC Polymer Science GA 849TE UT WOS:000223562900005 ER PT J AU Kwok, R Zwally, HJ Yi, DH AF Kwok, R Zwally, HJ Yi, DH TI ICESat observations of Arctic sea ice: A first look SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID APRIL 1997; OCEAN; AREA AB Analysis of near-coincident ICESat and RADARSAT imagery shows that the retrieved elevations from the laser altimeter are sensitive to new openings ( containing thin ice or open water) in the sea ice cover as well as to surface relief of old and first-year ice. The precision of the elevation estimates, measured over relatively flat sea ice, is similar to2 cm. Using the thickness of thin-ice in recent openings to estimate sea level references, we obtain the sea-ice freeboard along the altimeter tracks. This step is necessitated by the large uncertainties in the sea surface topography compared to that required for accurate determination of freeboard. Unknown snow depth introduces the largest uncertainty in the conversion of freeboard to ice thickness. Surface roughness is also derived, for the first time, from the variability of successive elevation estimates along the altimeter track. Overall, these ICESat measurements provide an unprecedented view of the Arctic Ocean ice cover at length scales at and above the spatial dimension of the altimeter footprint of similar to70 m. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ron.kwok@jpl.nasa.gov RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 5 TC 101 Z9 107 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 AUG 18 PY 2004 VL 31 IS 16 AR L16401 DI 10.1029/2004GL020309 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 849MY UT WOS:000223544100006 ER PT J AU Holzworth, RH Goldberg, RA AF Holzworth, RH Goldberg, RA TI Electric field measurements in noctilucent clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE noctilucent cloud; electric field ID POLAR SUMMER MESOSPHERE; MIDDLE-ATMOSPHERE; PMSE; DROPPS; AEROSOLS; VICINITY; REGIONS; ECHOES; ROCKET; RADAR AB [1] Two rockets were flown through noctilucent clouds (NLC) during the Distribution and Role of Particles in the Polar Summer Mesosphere using Coordinated Rocket, Radar, and Lidar Techniques (DROPPS) rocket experiment from Andoya Rocket Range, Norway, in July 1999. Each rocket was equipped with three-axis, double-double, high-impedance Langmuir probes ( 12 probes each flight) and produced unprecedented resolution of the electric potential distribution around the rockets in and near both a weak NLC ( DROPPS1) and a very strong NLC (DROPPS2). Detailed analysis of the vehicle interaction during the weak NLC encounter, in which no large geophysical electric fields were detected [ Holzworth et al., 2001], provided a basis for understanding the strong NLC encounter by DROPPS2, where geophysical electric fields reached 3 V m(-1). The electric field orientation is shown to be vertically downward. In the case of the strong NLC encounter a layer of excess positive charge at the top of the layer reached a density of 2 pC m(-3), deduced from the sharp field gradient. The total integrated potential drop through the NLC was 2 kV. C1 Univ Washington, Seattle, WA 98195 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Holzworth, RH (reprint author), Univ Washington, 310 Condon Hall,Box 351310, Seattle, WA 98195 USA. EM bobholz@washington.edu; goldberg@pop600.gsfc.nasa.gov RI Goldberg, Richard /E-1881-2012 NR 17 TC 9 Z9 9 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 18 PY 2004 VL 109 IS D16 AR D16203 DI 10.1029/2003JD004468 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 849NR UT WOS:000223546000001 ER PT J AU Martonchik, JV Diner, DJ Kahn, R Gaitley, B Holben, BN AF Martonchik, JV Diner, DJ Kahn, R Gaitley, B Holben, BN TI Comparison of MISR and AERONET aerosol optical depths over desert sites SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RETRIEVAL; DUST AB Comparisons of the Multi-angle Imaging SpectroRadiometer (MISR) aerosol optical depths (AOD) with those of the AErosol RObotic NETwork (AERONET) were made at four desert sites, covering a two-year time period from December 2000 to November 2002. The two data sets show good correlation with no obvious systematic biases or trends, demonstrating MISR's ability to retrieve reliable visible and near infrared AOD over surfaces with relatively high reflectance. For MISR AOD obtained at 17.6 km spatial resolution, the estimated uncertainty is about 0.08. When the spatial resolution was degraded to 52.8 km, the estimated AOD uncertainty decreased to about 0.05. Year-long time-series comparisons of MISR and AERONET AOD at the four desert sites showed that MISR can quantitatively capture the temporal nature of strong dust activity in desert regions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Martonchik, JV (reprint author), CALTECH, Jet Prop Lab, Mail Stop 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM john.v.martonchik@jpl.nasa.gov RI Kahn, Ralph/D-5371-2012 OI Kahn, Ralph/0000-0002-5234-6359 NR 11 TC 115 Z9 118 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 17 PY 2004 VL 31 IS 16 AR L16102 DI 10.1029/2004GL019807 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 849MW UT WOS:000223543900003 ER PT J AU Douglass, AR Stolarski, RS Strahan, SE Connell, PS AF Douglass, AR Stolarski, RS Strahan, SE Connell, PS TI Radicals and reservoirs in the GMI chemistry and transport model: Comparison to measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone; assessment ID HALOGEN OCCULTATION EXPERIMENT; INITIATIVE ASSESSMENT MODEL; POLAR STRATOSPHERIC CLOUD; IN-SITU OBSERVATIONS; LOWERMOST STRATOSPHERE; NORTHERN-HEMISPHERE; GENERAL-CIRCULATION; REACTIVE NITROGEN; UPPER-ATMOSPHERE; UARS PLATFORM AB [1] We have used a three-dimensional chemistry and transport model (CTM), developed under the Global Modeling Initiative (GMI), to carry out two simulations of the composition of the stratosphere under changing halogen loading for 1995 through 2030. The two simulations differ only in that one uses meteorological fields from a general circulation model while the other uses meteorological fields from a data assimilation system. A single year's winds and temperatures are repeated for each 36-year simulation. We compare results from these two simulations with an extensive collection of data from satellite and ground-based measurements for 1993 - 2000. Comparisons of simulated fields with observations of radical and reservoir species for some of the major ozone-destroying compounds are of similar quality for both simulations. Differences in the upper stratosphere, caused by transport of total reactive nitrogen and methane, impact the balance among the ozone loss processes and the sensitivity of the two simulations to the change in composition. C1 NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 21250 USA. RP Douglass, AR (reprint author), NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. EM anne.r.douglass@nasa.gov RI Douglass, Anne/D-4655-2012; Strahan, Susan/H-1965-2012; Stolarski, Richard/B-8499-2013 OI Stolarski, Richard/0000-0001-8722-4012 NR 62 TC 38 Z9 38 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 AUG 17 PY 2004 VL 109 IS D16 AR D16302 DI 10.1029/2004JD004632 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 849NL UT WOS:000223545400002 ER PT J AU Walker, JP Houser, PR Willgoose, GR AF Walker, JP Houser, PR Willgoose, GR TI Active microwave remote sensing for soil moisture measurement: a field evaluation using ERS-2 SO HYDROLOGICAL PROCESSES LA English DT Article DE remote sensing; soil moisture; active microwave; synthetic aperture radar; backscattering; backscattering models; soil roughness; ERS-2 ID APERTURE RADAR DATA; BARE SOIL; SURFACE-ROUGHNESS; RADIATIVE-TRANSFER; BASIN-SCALE; C-BAND; SCATTERING; EMISSION; MODEL; BACKSCATTERING AB Active microwave remote sensing observations of backscattering, such as C-band vertically polarized synthetic aperture radar (SAR) observations from the second European remote sensing (ERS-2) satellite, have the potential to measure moisture content in a near-surface layer of soil. However, SAR backscattering observations are highly dependent on topography, soil texture, surface roughness and soil moisture, meaning that soil moisture inversion from single frequency and polarization SAR observations is difficult. In this paper, the potential for measuring near-surface soil moisture with the ERS-2 satellite is explored by comparing model estimates of backscattering with ERS-2 SAR observations. This comparison was made for two ERS-2 overpasses coincident with near-surface soil moisture measurements in a 6 ha catchment using 15-cm time domain reflectometry probes on a 20 m grid. In addition, 1-cm soil moisture data were obtained from a calibrated soil moisture model. Using state-of-the-art theoretical, semi-empirical and empirical backscattering models, it was found that using measured soil moisture and roughness data there were root mean square (RMS) errors from 3.5 to 8.5 dB and r(2) values from 0.00 to 0.25, depending on the backscattering model and degree of filtering. Using model soil moisture in place of measured soil moisture reduced RMS errors slightly (0.5 to 2 dB) but did not improve r(2) values. Likewise, using the first day of ERS-2 backscattering and soil moisture data to solve for RMS surface roughness reduced RMS errors in backscattering for the second day to between 0.9 and 2.8 dB, but did not improve r(2) values. Moreover, RMS differences were as large as 3.7 dB and r(2) values as low as 0.53 between the various backscattering models, even when using the same data as input. These results suggest that more research is required to improve the agreement between backscattering models, and that ERS-2 SAR data may be useful for estimating fields-scale average soil moisture but not variations at the hillslope scale. Copyright (C) 2004 John Wiley Sons, Ltd. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. Univ Newcastle, Dept Civil Surveying & Environm Engn, Callaghan, NSW 2308, Australia. RP Walker, JP (reprint author), Univ Melbourne, Dept Civil & Environm Engn, Parkville, Vic 3010, Australia. EM jiwalker@unimelb.edu.au RI Willgoose, Garry/A-1492-2008; Walker, Jeffrey/D-2624-2009; Houser, Paul/J-9515-2013 OI Willgoose, Garry/0000-0001-5175-4935; Houser, Paul/0000-0002-2991-0441 NR 60 TC 44 Z9 46 U1 0 U2 15 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 AUG 15 PY 2004 VL 18 IS 11 BP 1975 EP 1997 DI 10.1002/hyp.1343 PG 23 WC Water Resources SC Water Resources GA 845UW UT WOS:000223271800001 ER PT J AU Kalashnikova, OV Sokolik, IN AF Kalashnikova, OV Sokolik, IN TI Modeling the radiative properties of nonspherical soil-derived mineral aerosols SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE mineral dust; nonsphericity; scattering phase functions; discrete dipole approximation ID DISCRETE-DIPOLE APPROXIMATION; SCATTERING MATRICES; INDIVIDUAL-PARTICLE; SINGLE-SCATTERING; LIGHT-SCATTERING; DUST PARTICLES; SIZE; BACKSCATTER; FRACTION; FEATURES AB Mineral dust aerosols have complex nonspherical shapes and varying composition. This study utilizes data on morphology (size and shape) and composition of dust particles to determine the extent to which the optical properties of real particles differ from those of spheres. A method for modeling the optical properties of complex particle mixtures is proposed. The method combines dust particle composition-shape-size (CSS) distributions reconstructed from the electron microscopy data, effective medium approximations and discrete dipole approximation. The method is used to compute optical characteristics of realistic dust mixtures representative of Saharan and Asian dust. We demonstrate that considered CSS distributions result in various differences in the extinction coefficient, single scattering albedo, asymmetry parameter and the scattering phase function relative to the volume-equivalent spheres and the mixtures of the randomly oriented oblate and prolate spheroids. Implications of these differences for radiation/climate modeling and remote sensing are discussed. (C) 2003 Elsevier Ltd. All rights reserved. C1 NASA, Jet Prop Lab, US Natl Res Council, Pasadena, CA 91109 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. RP Kalashnikova, OV (reprint author), NASA, Jet Prop Lab, US Natl Res Council, MS 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM olga.v.kalashnikova@jpl.nasa.gov NR 44 TC 81 Z9 84 U1 1 U2 11 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 AUG 15 PY 2004 VL 87 IS 2 BP 137 EP 166 DI 10.1016/j.jqsrt.2003.12.026 PG 30 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 831BG UT WOS:000222167300003 ER PT J AU Choi, SR Pereira, JM Janosik, LA Bhatt, RT AF Choi, SR Pereira, JM Janosik, LA Bhatt, RT TI Foreign object damage in flexure bars of two gas-turbine grade silicon nitrides SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE foreign object damage; silicon nitrides; impact damage; mechanical testing ID IMPACT DAMAGE; STRENGTH DEGRADATION; STRUCTURAL CERAMICS; TENSILE CREEP; SURFACES; SPHERES; MODEL AB Foreign object damage (FOD) behavior of two commercial gas-turbine grade silicon nitrides, AS800 and SN282, was determined at ambient temperature through strength testing of flexure test specimens impacted by steel ball projectiles with a diameter of 1.59 mm in a velocity range from 220 to 440 m/s. AS800 silicon nitride exhibited a greater FOD resistance than SN282, primarily due to its greater value of fracture toughness (K-lc) The use of an additional equiaxed, fine-grained silicon nitride (NC132) showed that fracture toughness was a key material parameter affecting FOD resistance. The observed damages generated by projectile impact were typically in the forms of well- or ill-developed ring and cone cracks with little presence of radial cracks. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Choi, SR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM sung.r.choi@grc.nasa.gov NR 27 TC 32 Z9 33 U1 0 U2 2 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 AUG 15 PY 2004 VL 379 IS 1-2 BP 411 EP 419 DI 10.1016/j.msea.2004.03.027 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 846QG UT WOS:000223330100053 ER PT J AU Dubovikov, PM Starchenko, NV Dubovikov, MS AF Dubovikov, PM Starchenko, NV Dubovikov, MS TI Dimension of the minimal cover and fractal analysis of time series SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article DE time series; fractal analysis; scaling; multifractals; stock price; feedback ID SPECULATIVE PRICES; FINANCIAL MARKET; BEHAVIOR; VOLATILITY; TURBULENCE; DIFFUSION AB We develop a new approach to the fractal analysis of time series of various natural, technological and social processes. To compute the fractal dimension, we introduce the sequence of the minimal covers associated with a decreasing scale delta. This results in new fractal characteristics: the dimension of minimal covers D-mu, the variation index It related to D, and the new multifractal spectrum zeta(q) defined on the basis of mu. Numerical computations performed for the financial series of companies entering Dow Jones Industrial Index show that the minimal scale tau(mu), which is necessary for determining mu with an acceptable accuracy, is almost two orders smaller than an analogous scale for the Hurst index H. This allows us to consider mu as a local fractal characteristic. The presented fractal analysis of the financial series shows that mu(t) is related to the stability of underlying processes. The results are interpreted in terms of the feedback. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. INTRAST, Moscow 109004, Russia. Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. RP Dubovikov, MS (reprint author), NASA, Goddard Inst Space Studies, 280 Broadway, New York, NY 10025 USA. EM mdubovikov@giss.nasa.gov NR 40 TC 13 Z9 17 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD AUG 15 PY 2004 VL 339 IS 3-4 BP 591 EP 608 DI 10.1016/j.physa.2004.03.025 PG 18 WC Physics, Multidisciplinary SC Physics GA 833YV UT WOS:000222378500030 ER PT J AU Kotchenova, SY Song, XD Shabanova, NV Potter, CS Knyazikhin, Y Myneni, RB AF Kotchenova, SY Song, XD Shabanova, NV Potter, CS Knyazikhin, Y Myneni, RB TI Lidar remote sensing for modeling gross primary production of deciduous forests SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE photosynthesis model; vertical foliage profiles; lidar remote sensing ID CANOPY PHOTOSYNTHESIS; STOMATAL CONDUCTANCE; BROADLEAF FORESTS; LASER ALTIMETER; LEAF MODELS; WAVE-FORMS; RADIATION; EXCHANGE; LAND; TRANSPIRATION AB The influence of foliage vertical distribution on vegetation gross primary production (GPP) is investigated in this study. A new photosynthesis model has been created that combines the standard sunlit/shaded leaf separation (two-leaf) and the multiple layer approaches and uses vertical foliage profiles measured by SLICER (the Scanning Lidar Imager of Canopies by Echo Recovery). Daily gross carbon assimilation rates calculated by this model were compared with the rates calculated by two other models, the two-leaf model and the combined two-leaf multilayer model utilizing uniform foliage profiles. The comparison was made over a wide range of profiles and weather conditions for two mixed deciduous forest stands in eastern Maryland, measured by SLICER in September 1995. Incident radiation pattern, environmental parameters and total amounts of sunlit and shaded leaves were the same for all three models. The difference was in the distributions of radiation and sunlit/shaded leaves inside the canopy. For the combined models, these distributions were calculated based on the vertical foliage profiles, while for the two-leaf model, empirical equations were used to account for the average amounts of absorbed radiation. The simulations showed that: (1) the use of a uniform foliage distribution instead of the actual one results in large differences in the calculated GPP values, up to 46.4% and 50.7% for the days with partial and total cloud cover; (2) the performance of the two-leaf model is extremely sensitive to the absorbed radiation pattern, its disagreement with the proposed model becomes insignificant when the average amounts of absorbed radiation are the same; (3) days with partial cloud cover and a greater fraction of diffuse radiation are characterized by higher GPP rates. These findings highlight the importance of vertical foliage profile and separate treatments of diffuse and direct radiation for photosynthesis modeling. (C) 2004 Elsevier Inc. All rights reserved. C1 Boston Univ, Dept Geog, Boston, MA 02215 USA. NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. RP Kotchenova, SY (reprint author), Boston Univ, Dept Geog, 675 Commonwealth Ave,457, Boston, MA 02215 USA. EM skotchen@bu.edu RI Myneni, Ranga/F-5129-2012; Beckley, Matthew/D-4547-2013 NR 44 TC 36 Z9 37 U1 1 U2 10 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 AUG 15 PY 2004 VL 92 IS 2 BP 158 EP 172 DI 10.1016/j.res.2004.05.010 PG 15 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 849VC UT WOS:000223568200003 ER PT J AU Korontzi, S Roy, DP Justice, CO Ward, DE AF Korontzi, S Roy, DP Justice, CO Ward, DE TI Modeling and sensitivity analysis of fire emissions in southern Africa during SAFARI 2000 SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID RESOLUTION IMAGING SPECTRORADIOMETER; TRACE GASES; SAVANNA FIRES; CARBON EMISSIONS; BIOMASS; MODIS; ECOSYSTEMS; ATMOSPHERE; PARTICLES; IMAGERY AB This paper uses three recently generated southern African satellite burned area products for the month of September 2000 in a sensitivity study of regional biomass burning emissions for a number of trace gases and particulates. Differences in the extent and location of areas burned among products generated from Moderate Resolution Imaging Spectroradiometer (MODIS), Systeme Pour l'Observation de In Terre (SPOT-VEGETATION), and Along Track Scanning Radiometer (ATSR-2) data are significant and result in different emissions estimates for woodland and grassland land cover types. Due to the different emission profiles in woodlands and grasslands, favoring relatively more products of incomplete combustion in woodlands compared with products of complete combustion in grasslands in the late dry season, these changes are not proportional to the differences in the burned area amounts. The importance of accurate burned area information not just in terms of the total area but also in terms of its spatial distribution becomes apparent from our modeling results. This paper highlights the urgent need for satellite data producers to provide accuracy assessments associated with satellite-derived products. Preferably, these accuracy data will be spatially explicit, or defined in a way that can be applied in a spatially explicit modeling context, to enable emissions uncertainties to be defined with respect to different landscape units in support of greenhouse gas emissions reporting. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Maryland, Dept Geog, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Enviropyron LLC, White Salmon, WA 98672 USA. RP Univ Maryland, Dept Geog, 2181 LeFrak, College Pk, MD 20742 USA. EM stef@hermes.geog.umd.edu NR 45 TC 29 Z9 34 U1 2 U2 3 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 AUG 15 PY 2004 VL 92 IS 2 BP 255 EP 275 DI 10.1016/j.rse.2004.06.010 PG 21 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 849VC UT WOS:000223568200011 ER PT J AU Natarajan, M Remsberg, EE Deaver, LE Russell, JM AF Natarajan, M Remsberg, EE Deaver, LE Russell, JM TI Anomalously high levels of NOx in the polar upper stratosphere during April, 2004: Photochemical consistency of HALOE observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OCCULTATION EXPERIMENT; NITRIC-OXIDE; ATMOSPHERE; OZONE; ENHANCEMENTS; VARIABILITY; ELECTRONS; TRANSPORT; NITROGEN; MODEL AB Significant perturbations to the odd nitrogen mixing ratios in the high latitude upper stratosphere are seen in the Halogen Occultation Experiment (HALOE) data during April, 2004. Sunrise observation of 99.1 ppbv of NOx (NO + NO2) at 68N represents the largest NOx measured near 2 hPa. Examination of potential vorticity maps indicates that these high NOx mixing ratios correspond to measurements made within the polar vortex. Photochemical model results show large reductions in ozone in response to the enhancements in NOx, and HALOE ozone data are in good agreement with the model results. Probable cause of these anomalous values of NOx in the upper stratosphere is the enhanced production of NO in the high latitude upper mesosphere/thermosphere regions due to the powerful solar flares and the associated energetic particle precipitation that took place during October-November, 2003, followed by downward transport in the polar winter. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. RP Natarajan, M (reprint author), NASA, Langley Res Ctr, 21 Langley Blvd, Hampton, VA 23681 USA. EM murali.natarajan@nasa.gov; e.e.remsberg@larc.nasa.gov; l.e.deaver@larc.nasa.gov; james.russell@hamptonu.edu NR 13 TC 32 Z9 32 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 14 PY 2004 VL 31 IS 15 AR L15113 DI 10.1029/2004GL020566 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 846UO UT WOS:000223342600006 ER PT J AU Schladow, SG Palmarsson, SO Steissberg, TE Hook, SJ Prata, FE AF Schladow, SG Palmarsson, SO Steissberg, TE Hook, SJ Prata, FE TI An extraordinary upwelling event in a deep thermally stratified lake SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SURFACE SHEAR-STRESS; CALIFORNIA-NEVADA; TAHOE AB A unique combination of temporal and spatial measurements provides a description of an extraordinarily large upwelling event in Lake Tahoe, CA-NV. The 4 d event, which engulfed half of the lake's surface and had an amplitude of 500 m, was recorded with in situ and space-borne instruments. The vertical mixing that ensued, was characterized by a large transfer of heat across the thermocline, resulting in the replacement of the distinct two-layer thermal structure by a diffuse, temperature gradient. Prior to the event, mixing energy due to the cooling flux at the surface was two orders of magnitude larger than the mixing energy associated with the wind. This dominance by cooling yielded the two-layer structure. During the event, wind energy was of similar magnitude to the cooling energy. The large bottom velocities that were produced at the end of the event were sufficient to re-suspend sediment into the water column. C1 Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. CSIRO, Aspendale, Vic 3195, Australia. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Schladow, SG (reprint author), Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA. EM gschladow@ucdavis.edu NR 15 TC 8 Z9 8 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 AUG 13 PY 2004 VL 31 IS 15 AR L15504 DI 10.1029/2004GL020392 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 846UN UT WOS:000223342500004 ER PT J AU Anderson, JD Schubert, G Jacobson, RA Lau, EL Moore, WB Palguta, JL AF Anderson, JD Schubert, G Jacobson, RA Lau, EL Moore, WB Palguta, JL TI Discovery of mass anomalies on Ganymede SO SCIENCE LA English DT Article AB We present the discovery of mass anomalies on Ganymede, Jupiter's third and largest Galilean satellite. This discovery is surprising for such a large icy satellite. We used the radio Doppler data generated with the Galileo spacecraft during its second encounter with Ganymede on 6 September 1996 to model the mass anomalies. Two surface mass anomalies, one a positive mass at high latitude and the other a negative mass at low latitude, can explain the data. There are no obvious geological features that can be identified with the anomalies. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RP Anderson, JD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM john.d.anderson@jpl.nasa.gov NR 6 TC 12 Z9 12 U1 0 U2 5 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 13 PY 2004 VL 305 IS 5686 BP 989 EP 991 DI 10.1126/science.1099050 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 845ND UT WOS:000223250700043 PM 15310898 ER PT J AU Wang, O Fukumori, I Lee, T Cheng, B AF Wang, O Fukumori, I Lee, T Cheng, B TI On the cause of eastern equatorial Pacific Ocean T-S variations associated with El Nino SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SALINITY VARIABILITY; TROPICAL PACIFIC; MODEL; CIRCULATION; BOUNDARY AB The nature of observed variations in temperature-salinity (T-S) relationship between El Nino and non-El Nino years in the pycnocline of the eastern equatorial Pacific Ocean (NINO3 region, 5degreesS-5degreesN, 150degreesW-90degreesW) is investigated using an ocean general circulation model. The origin of the subject water mass is identified using the adjoint of a simulated passive tracer. The higher salinity during El Nino is attributed to larger convergence of saltier water from the Southern Hemisphere and smaller convergence of fresher water from the Northern Hemisphere. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wang, O (reprint author), CALTECH, Jet Prop Lab, MS 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM owang@pacific.jpl.nasa.gov; if@pacific.jpl.nasa.gov; tlee@pacific.jpl.nasa.gov; bcheng@pacific.jpl.nasa.gov NR 17 TC 6 Z9 6 U1 0 U2 5 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 AUG 12 PY 2004 VL 31 IS 15 AR L15309 DI 10.1029/2004GL020188 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 846UM UT WOS:000223342400001 ER PT J AU Min, QL Minnis, P Khaiyer, MM AF Min, QL Minnis, P Khaiyer, MM TI Comparison of cirrus optical depths derived from GOES 8 and surface measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE cloud optical depth; GOES; MFRSR ID CLOUD PROPERTIES; SATELLITE MEASUREMENTS; RADAR AB Ground-based passive radiometer measurements are used to validate satellite-derived cirrus optical depths over the Atmospheric Radiation Measurement Program Southern Great Plains site during March 2000. Optical depths derived from direct beam measurements by a multifilter rotating shadow band radiometer were well correlated with those determined from the Geostationary Operational Environmental Satellite, especially in relatively homogenous cloud fields. Compared to the multifilter rotating shadow band radiometer (MFRSR) results, on average, the satellite retrieval overestimated optical depth by similar to0.67 (29%), even though 75% of the GOES values were within +/-1.0 of the MFRSR results. Some of the bias is attributable to cloud inhomogeneities, mismatches in observed clouds, errors in the surface albedo, and possible errors in the ice crystal scattering phase function. The results demonstrate the potential for using MFRSR data, available over many parts of the globe, for validating satellite cloud retrievals in many different surface and atmospheric conditions. C1 SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12203 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Analyt Serv & Mat Inc, Hampton, VA 23666 USA. RP Min, QL (reprint author), SUNY Albany, Atmospher Sci Res Ctr, 251 Fuller Rd,Rm L215, Albany, NY 12203 USA. EM min@asrc.cestm.albany.edu; p.minnis@larc.nasa.gov; m.m.khaiyer@larc.nasa.gov RI Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 20 TC 21 Z9 21 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 12 PY 2004 VL 109 IS D15 AR D15207 DI 10.1029/2003JD004390 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 846UU UT WOS:000223343500002 ER PT J AU Park, RJ Jacob, DJ Field, BD Yantosca, RM Chin, M AF Park, RJ Jacob, DJ Field, BD Yantosca, RM Chin, M TI Natural and transboundary pollution influences on sulfate-nitrate-ammonium aerosols in the United States: Implications for policy SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE trans-Pacific transport; Asian pollution; aerosols ID GLOBAL 3-DIMENSIONAL MODEL; GENERAL-CIRCULATION MODEL; TRANS-PACIFIC TRANSPORT; TROPOSPHERIC OZONE; ASIAN DUST; CARBON-MONOXIDE; SURFACE OZONE; NORTH-AMERICA; APRIL 1998; TRACE-P AB We use a global three-dimensional coupled oxidant-aerosol model (GEOS-CHEM) to estimate natural and transboundary pollution influences on sulfate-nitrate-ammonium aerosol concentrations in the United States. This work is motivated in part by the Regional Haze Rule of the U.S. Environmental Protection Agency (EPA), which requires immediate action to improve visibility in U.S. wilderness areas along a linear trajectory toward an endpoint of "natural visibility conditions'' by 2064. We present full-year simulations for 1998 and 2001 and evaluate them with nationwide networks of observations in the United States and Europe (Interagency Monitoring of Protected Visual Environments (IMPROVE), Clean Air Status and Trends Network (CASTNET), National Atmospheric Deposition Program (NADP), European Monitoring and Evaluation Programme (EMEP)) and with Asian outflow observations from the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) aircraft mission. Shutting off U. S. anthropogenic emissions in the model defines "background'' aerosol concentrations representing contributions from both natural and transboundary pollution sources. We find that transboundary transport of pollution from Canada, Mexico, and Asia dominates over natural influences for both sulfate and nitrate. Trans-Pacific transport of Asian pollution accounts for 30% of background sulfate in both the western and eastern United States. Our best estimates of natural concentrations for ammonium sulfate and ammonium nitrate in the United States are either consistent with or lower than the default values recommended by EPA for natural visibility calculations. However, the large transboundary pollution influence in our calculation suggests that a natural visibility objective cannot be approached without international emission controls. C1 Harvard Univ, Dept Earth & Planetary Sci, Div Engn & Appl Sci, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Harvard Univ, Dept Earth & Planetary Sci, Div Engn & Appl Sci, 12 Oxford St, Cambridge, MA 02138 USA. EM rjp@io.harvard.edu; djj@io.harvard.edu; bdf@io.harvard.edu; bmy@io.harvard.edu; chin@rondo.gsfc.nasa.gov RI Chin, Mian/J-8354-2012; Yantosca, Robert/F-7920-2014; Chem, GEOS/C-5595-2014; Park, Rokjin/I-5055-2012; Martin, Randall/C-1205-2014 OI Yantosca, Robert/0000-0003-3781-1870; Park, Rokjin/0000-0001-8922-0234; Martin, Randall/0000-0003-2632-8402 NR 80 TC 494 Z9 504 U1 7 U2 77 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 AUG 12 PY 2004 VL 109 IS D15 AR D15204 DI 10.1029/2003JD004473 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 846UU UT WOS:000223343500003 ER PT J AU Gao, CJ Zhang, SN AF Gao, CJ Zhang, SN TI Reissner-Nordstrom metric in the Friedman-Robertson-Walker universe SO PHYSICS LETTERS B LA English DT Article AB The metric for a Reissner-Nordstrom black hole in the background of the Friedman-Robertson-Walker universe is obtained. Then we verified it and discussed the influence of the evolution of the universe on the size of the black hole. To study the problem of the orbits of a planet in the expanding universe, we rewrote the metric in the Schwarzschild coordinates system and deduced the equation of motion for a planet. (C) 2004 Elsevier B.V. All rights reserved. C1 Tsing Hua Univ, Dept Phys, Beijing 100084, Peoples R China. Tsing Hua Univ, Ctr Astrophys, Beijing 100084, Peoples R China. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. Chinese Acad Sci, Inst High Energy Phys, Lab Particle Astrophys, Beijing 100039, Peoples R China. RP Gao, CJ (reprint author), Tsing Hua Univ, Dept Phys, Beijing 100084, Peoples R China. EM gaocj@mail.tsinghua.edu.cn; zhangsn@mail.tsinghua.edu.cn NR 9 TC 24 Z9 26 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 12 PY 2004 VL 595 BP 28 EP 35 DI 10.1016/j.physletb.2004.05.076 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 844FO UT WOS:000223143300005 ER PT J AU Atteberry, JE Agosta, DS Nattrass, CE Leisure, RG Jacob, I Bowman, RC Yeheskel, O AF Atteberry, JE Agosta, DS Nattrass, CE Leisure, RG Jacob, I Bowman, RC Yeheskel, O TI Temperature dependence of the elastic moduli of polycrystalline LaAlxNi5-(x) and LaSnxNi5-x SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE hydrogen storage materials; elasticity; ultrasonics ID CONSTANTS; DEGRADATION; HYDRIDES; LATTICE; LANI5; TIN AB The elastic moduli of the polycrystalline intermetallic compounds LaAlxNi5-x (x = 0, 0.25, 0.50 and 1.00) have been measured over the temperature range 3-415 K and those of LaSnxNi5-x (x = 0.10, 0.22, 0.40 and 0.50) over the temperature range 65-400 K. The samples were prepared by a hot isostatic pressing technique and had near theoretical densities with porosities ranging from 0 to 2%. In order to compare values for different concentrations small corrections were made for porosity so that values expected for the theoretical density were found. The temperature dependence of the moduli resembles that of ordinary metals; the moduli approach zero temperature with zero slope and decrease monotonically with increasing temperature at higher temperatures. Poisson's ratio is almost temperature-independent increasing from 0.307 for LaNi5 at low temperatures to 0.313 at 415 K. The acoustic contribution to the low-temperature specific heat, calculated from the elastic moduli measured at 3 K, ranges from 2.21 x 10(-4) T3 to 2.31 x 10(-4) T-3 J/(mol K-4) for the aluminum alloys. The corresponding Debye temperatures range from 370 to 375 K. (C) 2004 Elsevier B.V. All rights reserved. C1 Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. Ben Gurion Univ Negev, Dept Nucl Engn, IL-84105 Beer Sheva, Israel. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Nucl Res Ctr Negev, IL-84190 Beer Sheva, Israel. RP Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. EM robert.leisure@colostate.edu RI Nattrass, Christine/J-6752-2016 OI Nattrass, Christine/0000-0002-8768-6468 NR 35 TC 9 Z9 11 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 EI 1873-4669 J9 J ALLOY COMPD JI J. Alloy. Compd. PD AUG 11 PY 2004 VL 376 IS 1-2 BP 139 EP 144 DI 10.1016/j.jallcom.2003.12.021 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 842SV UT WOS:000223025400026 ER PT J AU Mari, C Evans, MJ Palmer, PI Jacob, DJ Sachse, GW AF Mari, C Evans, MJ Palmer, PI Jacob, DJ Sachse, GW TI Export of Asian pollution during two cold front episodes of the TRACE-P experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE warm conveyor belt; TRACE-P; pollution ID MARINE BOUNDARY-LAYER; LONG-RANGE TRANSPORT; NORTH PACIFIC; AIR-POLLUTION; UPPER TROPOSPHERE; WESTERN PACIFIC; INTERCONTINENTAL TRANSPORT; CHEMICAL EVOLUTION; REACTIVE NITROGEN; CARBON-MONOXIDE AB Two cold front episodes were sampled during the two flights out of Yokota, Japan, during the Transport and Chemical Evolution Over the Pacific (TRACE-P) experiment during March 2001. The data from these two flights are examined using a mesoscale three-dimensional model. We show how these cyclonic systems have impacted the export of pollution out of the Asian continent. We contrast the relative role of convection and ascent in the warm conveyor belts associated with the cyclone during these two episodes. Although the necessary meteorological conditions for an efficient export of pollution are met during flight 13 (i.e., the occurrences of the warm conveyor belt near the source regions), no significant pollution is simulated in the mid-Pacific in the lower and middle troposphere. The efficient ventilation of the WCB by convection near the coast, the advection by the anticyclonical flow above 700 hPa, and the downward motion associated with the Pacific high in the remote ocean significantly prevent any long-range transport of undiluted pollution in the WCB. During flight 15 the conveyor belts have already moved to the remote ocean. The polluted plume is split by the rising air in the warm conveyor belt which transports CO-poor air northward and by the oceanic convection which transports clean air masses upward. These mechanisms lead to the dilution of Asian pollution in WCB en route to North America and add to the episodic nature of the Asian outflow by fragmenting the pollution plume. C1 Univ Toulouse 3, CNRS, UMR 5560, Lab Aerol, F-31400 Toulouse, France. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Univ Toulouse 3, CNRS, UMR 5560, Lab Aerol, F-31400 Toulouse, France. EM marc@aero.obs-mip.fr RI Palmer, Paul/F-7008-2010; Evans, Mathew/A-3886-2012 OI Evans, Mathew/0000-0003-4775-032X NR 53 TC 24 Z9 26 U1 1 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 AUG 11 PY 2004 VL 109 IS D15 AR D15S17 DI 10.1029/2003JD004307 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 846UT UT WOS:000223343300001 ER PT J AU Belsole, E Worrall, DM Hardcastle, MJ Birkinshaw, M Lawrence, CR AF Belsole, E Worrall, DM Hardcastle, MJ Birkinshaw, M Lawrence, CR TI XMM-Newton observations of three high-redshift radio galaxies SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : active; galaxies : individual : 3C 184; galaxies : individual : 3C 292; galaxies : individual : 3C 322; X-rays : galaxies; radio lines : galaxies ID X-RAY-EMISSION; MAGNETIC-FIELD STRENGTHS; CLUSTER ENVIRONMENTS; INTRACLUSTER MEDIUM; UNIFIED SCHEME; CYGNUS-A; CHANDRA; QUASARS; LOBES; Z=1.786 AB We present the results of XMM-Newton observations of three powerful high-redshift radio galaxies 3C 184, 3C 292 and 3C 322. Although none of the sources lies in as rich an X-ray-emitting environment as is seen for some powerful radio galaxies at low redshift, the environments provide sufficient pressure to confine the radio lobes. The weak gas emission is particularly interesting for 3C 184, where a gravitational arc is seen, suggesting the presence of a massive cluster. Here, Chandra data complement the XMM-Newton measurements by spatially separating X-rays from the extended atmosphere, the nucleus and the small-scale radio source. For 3C292, the X-ray-emitting gas has a temperature of similar to2 keV and a luminosity of 6.5 x 10(43) erg s(-1), characteristic of a poor cluster. In all three cases, structures where the magnetic-field strength can be estimated through combining measurements of radio synchrotron and inverse-Compton X-ray emission are consistent with being in a state of minimum total energy. 3C184 and 3C 292 (and possibly 3C 322) have a heavily absorbed component of nuclear emission of N-H similar to few times 10(23) cm(-2). C1 Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Belsole, E (reprint author), Univ Bristol, Dept Phys, Tyndall Ave, Bristol BS8 1TL, Avon, England. EM e.belsole@bristol.ac.uk RI Hardcastle, Martin/E-2264-2012 OI Hardcastle, Martin/0000-0003-4223-1117 NR 44 TC 26 Z9 26 U1 0 U2 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD AUG 11 PY 2004 VL 352 IS 3 BP 924 EP 938 DI 10.1111/j.1365-2966.2004.07983.x PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 842VH UT WOS:000223032000024 ER PT J AU Hellier, C Mukai, K AF Hellier, C Mukai, K TI On the iron K alpha complex in magnetic cataclysmic variables SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries : close; novae, cataclysmic variables; X-rays : stars ID WHITE-DWARF; AM HERCULIS; EX HYDRAE; ACCRETION; SPECTRA; DENSITY; EMISSION; REGION AB We present a compilation of spectra of the iron K region in magnetic cataclysmic variables, using data from the Chandra High-Energy Transmission Grating (HETG). The H-like, He-like and fluorescent components are clearly resolved, and there are hints of the structure within each component. The different shape of the He-like component in AM Her might be related to greater cyclotron cooling in this star. A surprising absence of Doppler shifts in the H- and He-like components implies that the X-ray emission is predominantly from the denser, lower velocity base of the accretion columns. This absence will allow Astro-E2 to resolve the structure in each component, leading to temperature diagnostics. We do not confirm the report that the H- and He-like components of AO Psc are Compton-broadened; however, we do detect a Compton-downshifted shoulder to the fluorescent line of GK Per. Further, a Doppler-shifted wing of this line arises in the high-velocity, pre-shock flow. C1 Univ Keele, Sch Chem & Phys, Keele ST5 5BG, Staffs, England. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hellier, C (reprint author), Univ Keele, Sch Chem & Phys, Keele ST5 5BG, Staffs, England. EM ch@astro.keele.ac.uk NR 19 TC 42 Z9 42 U1 0 U2 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD AUG 11 PY 2004 VL 352 IS 3 BP 1037 EP 1040 DI 10.1111/j.1365-2966.2004.07995.x PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 842VH UT WOS:000223032000034 ER PT J AU Tanvir, NR Barnard, VE Blain, AW Fruchter, AS Kouveliotou, C Natarajan, P Ramirez-Ruiz, E Rol, E Smith, IA Tilanus, RPJ Wijers, RAMJ AF Tanvir, NR Barnard, VE Blain, AW Fruchter, AS Kouveliotou, C Natarajan, P Ramirez-Ruiz, E Rol, E Smith, IA Tilanus, RPJ Wijers, RAMJ TI The submillimetre properties of gamma-ray burst host galaxies SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Review DE stars : evolution; dust, extinction; galaxies : evolution; cosmology : observations; gamma-rays : bursts; infrared : galaxies ID HUBBLE-SPACE-TELESCOPE; COSMIC STAR-FORMATION; ULTRALUMINOUS INFRARED GALAXIES; LYMAN BREAK GALAXIES; DEEP-FIELD-NORTH; 23 JANUARY 1999; OPTICAL AFTERGLOW; STARBURST GALAXIES; GRB 990123; MULTIWAVELENGTH OBSERVATIONS AB Long-duration gamma-ray bursts (GRBs) accompany the deaths of some massive stars and hence, because massive stars are short-lived, are a tracer of star formation activity. Given that GRBs are bright enough to be seen to very high redshifts and detected even in dusty environments, they should therefore provide a powerful probe of the global star formation history of the Universe. The potential of this approach can be investigated via submillimetre (submm) photometry of GRB host galaxies. Submm luminosity also correlates with star formation rate, so the distribution of host-galaxy submm fluxes should allow us to test the two methods for consistency. Here, we report new JCMT/SCUBA 850-mum measurements for 15 GRB hosts. Combining these data with results from previous studies, we construct a sample of 21 hosts with < 1.4 mJy errors. We show that the distribution of apparent 850-μm flux densities of this sample is reasonably consistent with model predictions, but there is tentative evidence of a dearth of submm-bright (>4 mJy) galaxies. Furthermore, the optical/infrared properties of the submm-brightest GRB hosts are not typical of the galaxy population selected in submm surveys, although the sample size is still small. Possible selection effects and physical mechanisms which may explain these discrepancies are discussed. C1 Univ Hertfordshire, Ctr Astrophys Res, Hatfield AL10 9AB, Herts, England. Joint Astron Ctr, Hilo, HI 96720 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. Yale Univ, Dept Astron, New Haven, CT 06250 USA. Inst Adv Study, Princeton, NJ 08540 USA. Osserv Astron Padova, I-35122 Padua, Italy. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Natl Inst Nucl & High Energy Phys, Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. RP Tanvir, NR (reprint author), Univ Hertfordshire, Ctr Astrophys Res, Coll Lane, Hatfield AL10 9AB, Herts, England. EM nrt@star.herts.ac.uk OI Wijers, Ralph/0000-0002-3101-1808 NR 107 TC 95 Z9 95 U1 1 U2 1 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD AUG 11 PY 2004 VL 352 IS 3 BP 1073 EP 1080 DI 10.1111/j.1365-2966.2004.08001.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 842VH UT WOS:000223032000038 ER PT J AU Shi, F Chanan, G Ohara, C Troy, M Redding, DC AF Shi, F Chanan, G Ohara, C Troy, M Redding, DC TI Experimental verification of dispersed fringe sensing as a segment phasing technique using the Keck telescope SO APPLIED OPTICS LA English DT Article ID MIRROR SEGMENTS; ALGORITHM AB Dispersed fringe sensing (DFS) is an efficient and robust method for coarse phasing of segmented primary mirrors (from one quarter of a wavelength to as much as the depth of focus of a single segment, typically several tens of microns). Unlike phasing techniques currently used for ground-based segmented telescopes, DFS does not require the use of edge sensors in order to sense changes in the relative heights of adjacent segments; this makes it particularly well suited for phasing of space-borne segmented telescopes, such as the James Webb Space Telescope. We validate DFS by using it to measure the piston errors of the segments of one of the Keck telescopes. The results agree with those of the Shack-Hartmann-based phasing scheme currently in use at Keck to within 2% over a range of initial piston errors of +/-16 mum. (C) 2004 Optical Society of America C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. RP Shi, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM shi@s383.jpl.nasa.gov NR 7 TC 19 Z9 24 U1 1 U2 5 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 AUG 10 PY 2004 VL 43 IS 23 BP 4474 EP 4481 DI 10.1364/AO.43.004474 PG 8 WC Optics SC Optics GA 846CE UT WOS:000223291600002 PM 15376423 ER PT J AU Rhoads, JE Xu, C Dawson, S Dey, A Malhotra, S Wang, JX Jannuzi, BT Spinrad, H Stern, D AF Rhoads, JE Xu, C Dawson, S Dey, A Malhotra, S Wang, JX Jannuzi, BT Spinrad, H Stern, D TI Luminous Ly alpha-emitting galaxy at redshift z=6.535: Discovery and spectroscopic confirmation SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; early universe; galaxies : evolution; galaxies : formation; galaxies : high-redshift ID EMISSION-LINES; O-II; STARBURST GALAXIES; PLANETARY-NEBULAE; STAR-FORMATION; REIONIZATION; EMITTERS; ABUNDANCES; UNIVERSE; SPECTRA AB We present a redshift z=6.535 galaxy discovered by its Lyalpha emission in a 9180 8Angstrom narrowband image from the Large Area Lyman Alpha survey. The Lyalpha line luminosity (1.1x10(43) ergs s(-1)) is among the largest known for star-forming galaxies at zapproximate to6.5. The line shows the distinct asymmetry that is characteristic of high-redshift Lyalpha. The 2 sigma lower bound on the observer-frame equivalent width is greater than 530 Angstrom. This is hard to reconcile with a neutral intergalactic medium (IGM) unless the Lyalpha line is intrinsically strong and is emitted from its host galaxy with an intrinsic Doppler shift of several hundred km s(-1). If the IGM is ionized, it corresponds to a rest-frame equivalent width greater than 40 Angstrom after correcting for Lyalpha forest absorption. We also present a complete spectroscopic follow-up of the remaining candidates with line flux greater than 2x10(-17) ergs cm(-2) s(-1) in our 1200 arcmin(2) narrowband image. These include another galaxy with a strong emission line at 9136 Angstrom and no detected continuum flux, which, however, is most likely an [O III] lambda5007 source at z=0.824, on the basis of a weak detection of the [O III] lambda4959 line. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Natl Opt Astron Observ, Tucson, AZ 85719 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rhoads, JE (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM rhoads@stsci.edu; chunxu@stsci.edu; sdawson@astro.berkeley.edu; adey@noao.edu; san@stsci.edu; bjannuzi@noao.edu; spinrad@astro.berkeley.edu; stern@zwolfkinder.jpl.nasa.gov NR 45 TC 91 Z9 91 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 AUG 10 PY 2004 VL 611 IS 1 BP 59 EP 67 DI 10.1086/422094 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 845IO UT WOS:000223236000007 ER PT J AU Kaspi, S Netzer, H Chelouche, D George, IM Nandra, K Turner, TJ AF Kaspi, S Netzer, H Chelouche, D George, IM Nandra, K Turner, TJ TI The properties and evolution of the highly ionized gas in MR 2251-178 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : nuclei; quasars : individual (MR 2251-178); techniques : spectroscopic; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; X-RAY-ABSORPTION; HUBBLE-SPACE-TELESCOPE; SEYFERT 1 GALAXIES; WARM ABSORBER; XMM-NEWTON; NGC 3783; ULTRAVIOLET; VARIABILITY; EMISSION AB We present the first XMM-Newton observations of the radio-quiet quasar MR 2251-178 obtained in 2000 and 2002. The EPIC pn spectra show a power-law continuum with a slope of Gamma=1.6 at high energies absorbed by at least two warm absorbers (WAs) intrinsic to the source. The underlying continuum in the earlier observation shows a "soft excess'' at low X-ray energies, which can be modeled as an additional power law with Gamma=2.9. The spectra also show a weak narrow iron Kalpha emission line. The high-resolution grating spectrum obtained in 2002 shows emission lines from N VI, O VII, O VIII, Ne IX, and Ne X, as well as absorption lines from the low-ionization ions of O III, O IV, and O V, and other confirmed and suspected weaker absorption lines. The O III-O V lines are consistent with the properties of the emission-line gas observed as extended optical [O III] emission in this source. The signal-to-noise ratio of the 2000 grating data is too low to detect any lines. We suggest a model for the high-resolution spectrum that consists of two or three WA components. The two-component model has a high-ionization WA with a column density of 10(21.5)-10(21.8) cm(-2) and a low-ionization absorber with a column density of 10(20.3) cm(-2). In the three-component model we add a lower ionization component that produces the observed iron M shell absorption lines. We investigate the spectral variations in MR 2251-178 over a period of 8.5 yr using data from ASCA, BeppoSAX, and XMM-Newton. All X-ray observations can be fitted with the above two power laws and the two absorbers. The observed luminosity variations seem to correlate with variations in the soft X-ray continuum. The 8.5 yr history of the source suggests a changing X-ray absorber due to material that enters and disappears from the line of sight on timescales of several months. We also present, for the first time, the entire Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of MR 2251-178. We detect emission from N III, C III, and O VI and at least four absorption systems in C III, H I, and O VI, one at -580 km s(-1) and at least three others that are blended together and form a wide trough covering the velocity range of 0 to -500 km s(-1). The general characteristics of the UV and X-ray absorbers are consistent with an origin in the same gas. C1 Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2AZ, England. Columbia Univ, Astrophys Grp, New York, NY 10027 USA. RP Kaspi, S (reprint author), Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. EM shai@wise.tau.ac.il NR 38 TC 32 Z9 32 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2004 VL 611 IS 1 BP 68 EP 80 DI 10.1086/422161 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 845IO UT WOS:000223236000008 ER PT J AU Ikebe, Y Bohringer, H Kitayama, T AF Ikebe, Y Bohringer, H Kitayama, T TI X-ray measurement of dark matter ''temperature'' in A1795 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; galaxies : clusters : general; X-rays : galaxies : clusters ID COOLING FLOWS; INTRACLUSTER MEDIUM; ABELL 1795; STATISTICAL PROPERTIES; CENTAURUS CLUSTER; GALAXY FORMATION; DENSITY PROFILE; PERSEUS CLUSTER; GAS-DENSITY; XMM-NEWTON AB We present a method from an X-ray observation of a galaxy cluster to measure the radial profile of the dark matter velocity dispersion, sigma(DM), and to compare the dark matter "temperature'' defined as mum(p)sigma(DM)(2)/k(B) with the gas temperature. The method is applied to the XMM-Newton observation of A1795. The ratio between the specific energy of the dark matter and that of the intracluster medium (ICM), which can be defined as beta(DM) in analogy with beta(spec), is found to be less than unity everywhere, ranging similar to0.3-0.8. In other words, the ICM temperature is higher than the dark matter "temperature,'' even in the central region where the radiative cooling time is short. A beta(DM) value smaller than unity can most naturally be explained by heating of the ICM. The excess energy of the ICM is estimated to be similar to1-3 keV per particle. C1 Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. Toho Univ, Dept Phys, Chiba 2748510, Japan. RP Ikebe, Y (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM ikebe@milkyway.gsfc.nasa.gov NR 73 TC 16 Z9 16 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2004 VL 611 IS 1 BP 175 EP 185 DI 10.1086/421986 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 845IO UT WOS:000223236000016 ER PT J AU Neff, SG Ulvestad, JS Teng, SH AF Neff, SG Ulvestad, JS Teng, SH TI A supernova factory in the merger system ARP 299 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (Arp 299, NGC 3690); galaxies : interactions; galaxies : starburst; galaxies : star clusters; radio continuum : galaxies ID LUMINOUS INFRARED GALAXIES; ACTIVE GALACTIC NUCLEI; X-RAY-EMISSION; M-CIRCLE-DOT; RADIO-EMISSION; SEYFERT-GALAXIES; ARP 299; STARBURST GALAXIES; MERGING GALAXIES; VLA OBSERVATIONS AB We have imaged the nearby galaxy merger Arp 299 at arcsecond and milliarcsecond resolution, using both the Very Large Array (VLA) and the Very Long Baseline Array. The large-scale radio emission from the merger contains five bright, compact radio sources embedded in diffuse emission, with diameters less than 200 pc. Supernova rates of 0.1-1 yr(-1) are required to produce the VLA-detected radio emission in these sources. Two of the compact VLA radio sources, designated source A and source D, have also been detected and imaged at milliarcsecond scales. Source A, which is associated with the nucleus of one of the merging galaxies, contains five milliarcsecond-scale sources, each with a radio power between 100 and 1000 times that of the Galactic supernova remnant Cassiopeia A. Four of these have flat or inverted spectra and appear to be young supernovae. Three of the VLBI-scale sources are located within 10 pc (projected) of one another, and two are separated by less than 3 pc, indicating that they all may be within the same super-star cluster or complex of such clusters. The brightest VLBI-scale source, A0, has an extremely inverted spectrum, with alphagreater than or similar to+2 at gigahertz frequencies. It seems to be the youngest supernova, having not yet broken out of its circumstellar shell. The milliarcsecond radio sources within source A appear to constitute a supernova factory, confirming the presence of an extreme starburst that peaked at least a few million years ago. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Neff, SG (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. EM neff@stars.gsfc.nasa.gov; julvesta@nrao.edu; stacyt@astro.umd.edu OI Ulvestad, James/0000-0002-9362-7237 NR 56 TC 45 Z9 45 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2004 VL 611 IS 1 BP 186 EP 199 DI 10.1086/383608 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 845IO UT WOS:000223236000017 ER PT J AU Prochaska, JX Bloom, JS Chen, HW Hurley, KC Melbourne, J Dressler, A Graham, JR Osip, DJ Vacca, WD AF Prochaska, JX Bloom, JS Chen, HW Hurley, KC Melbourne, J Dressler, A Graham, JR Osip, DJ Vacca, WD TI The host galaxy of GRB 031203: Implications of its low metallicity, low redshift, and starburst nature SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : photometry; gamma rays : bursts; stars : formation ID GAMMA-RAY BURSTS; INTERNATIONAL SPECTROSCOPIC SURVEY; 29 MARCH 2003; STAR-FORMATION; LUMINOSITY FUNCTION; LIGHT-CURVE; ABUNDANCES; EMISSION; DUST; EXTINCTION AB We present Keck/NIRSPEC near-IR images and Magellan/IMACS optical spectroscopy of the host galaxy of GRB 031203. The host is an actively star-forming galaxy at z=0.1055+/-0.0001. This is the lowest redshift GRB to date, aside from GRB 980425. From the hydrogen Balmer lines, we infer an extinction of A(V)=3.62+/-0.25 or a total reddening E-T (B-V)=1.17+/-0.1 toward the sight line to the nebular regions. After correcting for reddening, we perform an emission-line analysis and derive an ISM temperature of T =13400+/-2000 K and electron density of n(e)=300 cm(-3). These imply a metallicity [O/H]=-0.72+/-0.15 dex and a roughly solar abundance pattern for N, Ne, S, and Ar. Integrating Halpha, we infer a dust-corrected star formation rate (SFR) of more than 11 M-circle dot yr(-1). These observations have the following implications: (1) The galaxy has a low K'-band luminosity Lapproximate toL*(K)/5, typical of GRB host galaxies. (2) The low redshift indicates GRB 031203 had an isotropic-equivalent gamma-ray energy release smaller than all previous confirmed GRB events. The burst discovery raises the likelihood of identifying many additional low-z, low-flux events with Swift. (3) The large SFR, low metallicity, and inferred hard radiation field are suggestive of massive star formation, supporting the collapsar model. (4) Several lines of evidence argue against the identification of GRB 031203 as an X-ray flash event. C1 Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Soc Fellows, Cambridge, MA 02138 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Carnegie Inst Washington, Carnegie Observ, Pasadena, CA 91101 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Carnegie Observ, Campanas Observ, La Serena, Chile. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Prochaska, JX (reprint author), Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. EM xavier@ucolick.org NR 73 TC 147 Z9 149 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2004 VL 611 IS 1 BP 200 EP 207 DI 10.1086/421988 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 845IO UT WOS:000223236000018 ER PT J AU Simpson, JP Rubin, RH Colgan, SWJ Erickson, EF Haas, MR AF Simpson, JP Rubin, RH Colgan, SWJ Erickson, EF Haas, MR TI On the measurement of elemental abundance ratios in inner Galaxy H II regions SO ASTROPHYSICAL JOURNAL LA English DT Article DE Galaxy : abundances; HII regions; ISM : abundances; ISM : individual (G333.6-0.2, W43) ID RECOMBINATION RATE COEFFICIENTS; PHOTOIONIZATION CROSS-SECTIONS; GALACTIC-HII-REGIONS; FINE-STRUCTURE LINES; ELECTRON COLLISION EXCITATION; COMBINED STELLAR STRUCTURE; FAR-INFRARED LINES; ATOMIC DATA; IRON PROJECT; ORION NEBULA AB Although variations in elemental abundance ratios in the Milky Way certainly exist, details remain uncertain, particularly in the inner Galaxy, where stars and H II regions in the Galactic plane are obscured optically. In this paper we revisit two previously studied, inner Galaxy H II regions: G333.6-0.2 and W43. We observed three new positions in G333.6-0.2 with the Kuiper Airborne Observatory and reobserved the central position with the Infrared Space Observatory's Long Wavelength Spectrometer in far-infrared lines of S++, N++, N+, and O++. We also added the N+ lines at 122 and 205 mum to the suite of lines measured in W43 by Simpson and coworkers. The measured electron densities range from similar to40 to over 4000 cm(-3) in a single H II region, indicating that abundance analyses must consider density variations, since the critical densities of the observed lines range from 40 to 9000 cm(-3). We propose a method to handle density variations and make new estimates of the S/H and N/H abundance ratios. We find that our sulfur abundance estimates for G333.6-0.2 and W43 agree with the S/H abundance ratios expected for the S/H abundance gradient previously reported by Simpson and coworkers, with the S/H values revised to be smaller as a result of changes in collisional excitation cross sections. The estimated N/H, S/H, and N/S ratios are the most reliable because of their small corrections for unseen ionization states (less than or similar to10%). The estimated N/S ratios for the two sources are smaller than what would be calculated from the N/H and S/H ratios in our previous paper. We compute models of the two H II regions to estimate corrections for the other unseen ionization states. We find, with large uncertainties, that oxygen does not have a high abundance, with the result that the N/O ratio is as high (similar to0.35) as previously reported. The reasons for the uncertainty in the ionization corrections for oxygen are both the nonuniqueness of the H II region models and the sensitivity of these models to different input atomic data and stellar atmosphere models. We discuss these predictions and conclude that only a few of the latest models adequately reproduce H II region observations, including the well-known, relatively large observed Ne++/O++ ratios in low- and moderate-excitation H II regions. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Simpson, JP (reprint author), SETI Inst, Moffett Field, CA 94035 USA. EM simpson@cygnus.arc.nasa.gov; rubin@cygnus.arc.nasa.gov; sean.colgan@nasa.gov; erickson@cygnus.arc.nasa.gov; michael.r.haas@nasa.gov RI Colgan, Sean/M-4742-2014 NR 97 TC 27 Z9 27 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 AUG 10 PY 2004 VL 611 IS 1 BP 338 EP 352 DI 10.1086/422028 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 845IO UT WOS:000223236000026 ER PT J AU Adams, FC Hollenbach, D Laughlin, G Gorti, U AF Adams, FC Hollenbach, D Laughlin, G Gorti, U TI Photoevaporation of circumstellar disks due to external far-ultraviolet radiation in stellar aggregates SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary systems : protoplanetary disks; stars : formation; stars : pre-main-sequence ID GIANT-PLANET FORMATION; HERBIG AE/BE STARS; NONEQUILIBRIUM PHOTODISSOCIATION REGIONS; ORION NEBULA CLUSTER; PROTOSTELLAR DISKS; SOLAR-SYSTEM; ACCRETION DISKS; INTERSTELLAR-MEDIUM; EXTRASOLAR PLANETS; TIDAL INTERACTION AB When stars form within small groups (with N(*) approximate to 100-500 members), their circumstellar disks are exposed to relatively little extreme-ultraviolet (EUV; hv > 13: 6 eV) radiation but a great deal of far-ultraviolet (FUV; 6 eV < hv < 13.6 eV) radiation (similar to10(3) times the local interstellar FUV field) from the most massive stars in the group. This paper calculates the mass-loss rates and evaporation timescales for circumstellar disks exposed to external FUV radiation. Previous work treated large disks and/or intense radiation fields in which the disk radius r(d) exceeds the critical radius r(g) where the sound speed in the FUV heated surface layer exceeds the escape speed; it has often been assumed that photoevaporation occurs for r(d) > r(g) and is negligible for r(d) < r(g). Since rg greater than or similar to 100 AU for FUV heating, this would imply little mass loss from the planet-forming regions of a disk. In this paper we focus on systems in which photoevaporation is suppressed because r(d) < r(g) and show that significant mass loss still takes place as long as r(d)/r(g) greater than or similar to0.1-0.2. Some of the gas extends beyond the disk edge ( or above the disk surface) to larger distances where the temperature is higher, the escape speed is lower, and an outflow develops. The resulting evaporation rate is a sensitive function of the central stellar mass and disk radius, which determine the escape speed, and the external FUV flux, which determines the temperature structure of the surface layers and outflowing gas. Disks around red dwarfs, low-mass stars with M(*) less than or similar to0.5 M(circle dot), are evaporated and shrink to disk radii r(d) less than or similar to15 AU on short timescales t less than or similar to10 Myr when exposed to moderate FUV fields with G(0) = 3000 (where G(0) = 1.7 for the local interstellar FUV field). The disks around solar-type stars are more durable. For intense FUV radiation fields with G0 30; 000, however, even these disks shrink to r(d) less than or similar to15 AU on timescales t similar to 10 Myr. Such fields exist within about 0.7 pc of the center of a cluster with N(*) approximate to 4000 stars. If our solar system formed in the presence of such strong FUV radiation fields, this mechanism could explain why Neptune and Uranus in our solar system are gas-poor, whereas Jupiter and Saturn are relatively gas-rich. This mechanism for photoevaporation can also limit the production of Kuiper Belt objects and can suppress giant planet formation in sufficiently large clusters, such as the Hyades, especially for disks associated with low-mass stars. C1 Univ Michigan, Dept Phys, Michigan Ctr Theoret Phys, Randall Lab 2477, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95064 USA. RP Adams, FC (reprint author), Univ Michigan, Dept Phys, Michigan Ctr Theoret Phys, Randall Lab 2477, 500 E Univ Ave, Ann Arbor, MI 48109 USA. NR 68 TC 179 Z9 178 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2004 VL 611 IS 1 BP 360 EP 379 DI 10.1086/421989 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 845IO UT WOS:000223236000028 ER PT J AU Gary, GA Moore, RL AF Gary, GA Moore, RL TI Eruption of a multiple-turn helical magnetic flux tube in a large flare: Evidence for external and internal reconnection that fits the breakout model of solar magnetic eruptions SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : activity; Sun : corona; Sun : coronal mass ejections (CMEs); Sun : flares; Sun : magnetic fields ID CORONAL MASS EJECTIONS; TRANSITION REGION; QUIESCENT PROMINENCES; VECTOR MAGNETOGRAMS; ACTIVE-REGION; FIELD LINES; EVOLUTION; ULTRAVIOLET; TOPOLOGY; EXPLORER AB We present observations and an interpretation of a unique multiple-turn spiral flux tube eruption from active region 10030 on 2002 July 15. The TRACE C IV observations clearly show a flux tube that is helical and erupting from within a sheared magnetic field. These observations are interpreted in the context of the breakout model for magnetic field explosions. The initiation of the helix eruption, as determined by a linear backward extrapolation, starts 25 s after the peak of the flare's strongest impulsive spike of microwave gyrosynchrotron radiation early in the flare's explosive phase, implying that the sheared core field is not the site of the initial reconnection. Within the quadrupolar configuration of the active region, the external and internal reconnection sites are identified in each of two consecutive eruptive flares that produce a double coronal mass ejection (CME). The first external breakout reconnection apparently releases an underlying sheared core field and allows it to erupt, leading to internal reconnection in the wake of the erupting helix. This internal reconnection releases the helix and heats the two-ribbon flare. These events lead to the first CME and are followed by a second breakout that initiates a second and larger halo CME. The strong magnetic shear in the region is compatible with the observed rapid proper motion and evolution of the active region. The multiple-turn helix originates from above a sheared-field magnetic inversion line within a filament channel, and starts to erupt only after fast breakout reconnection has started. These observations are counter to the standard flare model and support the breakout model for eruptive flare initiation. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Gary, GA (reprint author), NASA, George C Marshall Space Flight Ctr, SD50, Huntsville, AL 35812 USA. EM allen.gary@nasa.gov; ron.moore@nasa.gov NR 48 TC 89 Z9 90 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2004 VL 611 IS 1 BP 545 EP 556 DI 10.1086/422132 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 845IO UT WOS:000223236000042 ER PT J AU Opher, M Liewer, PC Velli, M Bettarini, L Gombosi, TI Manchester, W DeZeeuw, DL Toth, G Sokolov, I AF Opher, M Liewer, PC Velli, M Bettarini, L Gombosi, TI Manchester, W DeZeeuw, DL Toth, G Sokolov, I TI Magnetic effects at the edge of the solar system: MHD instabilities, the de Laval nozzle effect, and an extended jet SO ASTROPHYSICAL JOURNAL LA English DT Article DE instabilities; interplanetary medium; ISM : kinematics and dynamics; MHD; solar wind; Sun : magnetic fields ID LOCAL INTERSTELLAR-MEDIUM; WIND INTERACTION; TERMINATION SHOCK; HELIOSPHERE; SHEET; PLASMA; FIELD; SIMULATIONS; MODEL AB To model the interaction between the solar wind and the interstellar wind, magnetic fields must be included. Recently, Opher et al. found that by including the solar magnetic field in a three-dimensional high-resolution simulation using the University of Michigan BATS-R-US code, a jet-sheet structure forms beyond the solar wind termination shock. Here we present an even higher resolution three-dimensional case in which the jet extends for 150 AU beyond the termination shock. We discuss the formation of the jet due to a de Laval nozzle effect and its subsequent large-period oscillation due to magnetohydrodynamic (MHD) instabilities. To verify the source of the instability, we also perform a simplified two-dimensional geometry MHD calculation of a plane fluid jet embedded in a neutral sheet with the profiles taken from our three-dimensional simulation. We find remarkable agreement with the full three-dimensional evolution. We compare both simulations and the temporal evolution of the jet, showing that the sinuous mode is the dominant mode that develops into a velocity-shear instability with a growth rate of 5 x 10(-9) s(-1) = 0.027 yr(-1). As a result, the outer edge of the heliosphere presents remarkable dynamics, such as turbulent flows caused by the motion of the jet. Further study, including neutrals and the tilt of the solar rotation from the magnetic axis, is required before we can definitively address how this outer boundary behaves. Already, however, we can say that the magnetic field effects are a major player in this region, changing our previous notion of how the solar system ends. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Florence, Dept Astron & Space Sci, I-50125 Florence, Italy. Dept Atmospher, Space Phys Res Lab, Ann Arbor, MI USA. RP Opher, M (reprint author), CALTECH, Jet Prop Lab, MS 169-506,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM merav.opher@jpl.nasa.gov RI De Zeeuw, Darren/F-3667-2011; Manchester, Ward/I-9422-2012; Gombosi, Tamas/G-4238-2011; Toth, Gabor/B-7977-2013; Sokolov, Igor/H-9860-2013 OI Gombosi, Tamas/0000-0001-9360-4951; Toth, Gabor/0000-0002-5654-9823; Sokolov, Igor/0000-0002-6118-0469 NR 37 TC 33 Z9 33 U1 0 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2004 VL 611 IS 1 BP 575 EP 586 DI 10.1086/422165 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 845IO UT WOS:000223236000045 ER PT J AU Farrah, D Priddey, R Wilman, R Haehnelt, M McMahon, R AF Farrah, D. Priddey, R. Wilman, R. Haehnelt, M. McMahon, R. TI THE X-RAY SPECTRUM OF THE z=6.30 QSO SDSS J1030+0524 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology: observations; galaxies: formation; galaxies: high-redshift; quasars: individual (SDSS J1030+0524); X-rays: galaxies AB We present a deep XMM-Newton observation of the z = 6.30 QSO SDSS J1030+0524, the second most distant quasar currently known. The data contain sufficient counts for spectral analysis, demonstrating the ability of XMM-Newton to measure X-ray spectral shapes of z similar to 6 QSOs with integration times greater than or similar to 100 ks. The X-ray spectrum is well fitted by a power law with index Gamma = 2.12 +/- 0.11, an optical-X-ray spectral slope of alpha(ox) = -1.80, and no absorption excess to the Galactic value, although our data are also consistent with a power-law index in the range 2.02 < Gamma < 2.5 and excess absorption in the range 0 < N-H (cm(-2)) < 8 x 10(22). There is also a H possible detection (similar to 2 sigma) of FeK alpha emission. The X-ray properties of this QSO are, overall, similar to those of lower redshift radio-quiet QSOs. This is consistent with the statement that the X-ray properties of radio-quiet QSOs show no evolution over 0 < z < 6.3. Combined with previous results, this QSO appears indistinguishable in any way from lower redshift QSOs, indicating that QSOs comparable to those seen locally existed less than 1 Gyr after the big bang. C1 [Farrah, D.] CALTECH, Jet Prop Lab, Spitzer Sci Ctr, Pasadena, CA 91125 USA. [Priddey, R.] Univ Hertfordshire, Dept Phys Astron & Math, Hatfield AL10 9AB, Herts, England. [Wilman, R.] Univ Durham, Dept Phys, Sci Labs, Durham DH1 3LE, England. [Haehnelt, M.; McMahon, R.] Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. RP Farrah, D (reprint author), CALTECH, Jet Prop Lab, Spitzer Sci Ctr, 1200 E Calif Blvd, Pasadena, CA 91125 USA. OI Haehnelt, Martin/0000-0001-8443-2393 FU ESA member states; USA (NASA) FX We thank Mark Lacy, Carol Lonsdale, Kirpal Nandra, and Mike Norman for helpful discussion and the referee for a very useful report. This Letter is based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and the USA (NASA). This research has made use of data from the High Energy Astrophysics Science Archive Research Center, provided by NASA's Goddard Space Flight Center, and from the NASA/IPAC Extragalactic Database, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. NR 41 TC 17 Z9 17 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2004 VL 611 IS 1 AR L13-L16 DI 10.1086/423669 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V24GX UT WOS:000208400000004 ER PT J AU Ilhan, F Tyson, DS Meador, MA AF Ilhan, F Tyson, DS Meador, MA TI Synthesis and chemosensory behavior of anthracene bisimide derivatives SO CHEMISTRY OF MATERIALS LA English DT Article ID ELECTRON-TRANSFER; WARFARE AGENTS; FLUORESCENCE; SIMULANTS; SENSORS; ARRAYS C1 NASA, Glenn Res Ctr, Polymers Branch, Div Mat, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. RP Meador, MA (reprint author), NASA, Glenn Res Ctr, Polymers Branch, Div Mat, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Michael.A.Meador@nasa.gov NR 22 TC 34 Z9 35 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD AUG 10 PY 2004 VL 16 IS 16 BP 2978 EP 2980 DI 10.1021/cm049508h PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 844MP UT WOS:000223162700002 ER PT J AU Irie, H Pagan, KL Tabazadeh, A Legg, MJ Sugita, T AF Irie, H Pagan, KL Tabazadeh, A Legg, MJ Sugita, T TI Investigation of polar stratospheric cloud solid particle formation mechanisms using ILAS and AVHRR observations in the Arctic SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NITRIC-ACID; DENITRIFICATION; NUCLEATION; WINTER; VORTEX AB Satellite observations of denitrification and ice clouds in the Arctic lower stratosphere in February 1997 are used with Lagrangian microphysical box model calculations to evaluate nucleation mechanisms of solid polar stratospheric cloud (PSC) particles. The occurrences of ice clouds are not correlated in time and space with the locations of back trajectories of denitrified air masses, indicating that ice particle surfaces are not always a prerequisite for the formation of solid PSCs that lead to denitrification. In contrast, the model calculations incorporating a pseudo-heterogeneous freezing process occurring at the vapor-liquid interface can quantitatively explain most of the observed denitrification when the nucleation activation free energy for nitric acid dihydrate formation is raised by only similar to10% relative to the current published values. Once nucleated, the conversion of nitric acid dihydrate to the stable trihydrate phase brings the computed levels of denitrification closer to the measurements. C1 Frontier Res Syst Global Change, Kanazawa Ku, Kanagawa 2360001, Japan. San Francisco State Univ, San Francisco, CA 94132 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Bay Area Environm Res Inst, Sonoma, CA USA. Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan. RP Irie, H (reprint author), Frontier Res Syst Global Change, Kanazawa Ku, 3173-25 Showa Machi, Kanagawa 2360001, Japan. EM irie@jamstec.go.jp OI Sugita, Takafumi/0000-0002-0508-7040 NR 17 TC 7 Z9 7 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 AUG 10 PY 2004 VL 31 IS 15 AR L15107 DI 10.1029/2004GL020246 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 846UK UT WOS:000223342200004 ER PT J AU Delo, CJ Kelso, RM Smits, AJ AF Delo, CJ Kelso, RM Smits, AJ TI Three-dimensional structure of a low-Reynolds-number turbulent boundary layer SO JOURNAL OF FLUID MECHANICS LA English DT Article ID WALL TURBULENCE; CHANNEL FLOW; SHEAR-FLOW; REGION; VISUALIZATION; PACKETS; MOTION AB A low-Reynolds-number zero-pressure-gradient incompressible turbulent boundary layer was investigated using a volumetric imaging technique. The Reynolds number based on momentum thickness was 700. The flow was tagged with a passive scalar from two spanwise dye slots to distinguish between fluid motions originating in the inner and outer portions of the boundary layer. The resulting volumetric scalar field was interrogated using a laser sheet scanner developed for this study. Two- and three-dimensional time-dependent visualizations of a 50 volume time series are presented (equivalent to 178 in length). In the outer portion of the boundary layer, scalar structures were observed to lie along lines in the (x, z)-plane, inclined to the streamwise (x-)direction in the range +/-50degrees. The ejection of brightly dyed fluid packets from the near-wall region was observed to be spatially organized, and related to the passage of the large-scale scalar structures. C1 Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. RP Delo, CJ (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RI Smits, Alexander/B-4083-2016 OI Smits, Alexander/0000-0002-3883-8648 NR 33 TC 17 Z9 18 U1 1 U2 8 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD AUG 10 PY 2004 VL 512 BP 47 EP 83 DI 10.1017/S0022112004009693 PG 37 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 849UN UT WOS:000223566600003 ER PT J AU Xiao, YP Jacob, DJ Wang, JS Logan, JA Palmer, PI Suntharalingam, P Yantosca, RM Sachse, GW Blake, DR Streets, DG AF Xiao, YP Jacob, DJ Wang, JS Logan, JA Palmer, PI Suntharalingam, P Yantosca, RM Sachse, GW Blake, DR Streets, DG TI Constraints on Asian and European sources of methane from CH4-C2H6-CO correlations in Asian outflow SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE methane; emissions; correlations ID PACIFIC TRACE-P; TRANSFORM INFRARED-SPECTROSCOPY; BIOMASS BURNING EMISSIONS; ATMOSPHERIC METHANE; CHEMICAL EVOLUTION; CARBON-MONOXIDE; AIRCRAFT OBSERVATIONS; ISOTOPIC COMPOSITION; CONTINENTAL OUTFLOW; TRANSPORT PATHWAYS AB Aircraft observations of Asian outflow from the Transport and Chemical Evolution Over the Pacific (TRACE-P) aircraft mission over the NW Pacific ( March and April 2001) show large CH4 enhancements relative to background, as well as strong CH4-C2H6-CO correlations that provide signatures of regional sources. We apply a global chemical transport model simulation of the CH4-C2H6-CO system for the TRACE-P period to interpret these observations in terms of CH4 sources and to explore in particular the unique constraints from the CH4-C2H6-CO correlations. We use as a priori a global CH4 source inventory constrained with National Oceanic and Atmospheric Administration (NOAA) Climate Monitoring and Diagnostics Laboratory (CMDL) surface observations [Wang et al., 2004]. We find that the observed CH4 concentration enhancements and CH4-C2H6-CO correlations in Asian outflow in TRACE-P are determined mainly by anthropogenic emissions from China and Eurasia (defined here as Europe and eastern Russia), with only little contribution from tropical sources (wetlands and biomass burning). The a priori inventory overestimates the observed CH4 enhancements and shows regionally variable biases for the CH4/C2H6 slope. The CH4/CO slopes are simulated without significant bias. Matching both the observed CH4 enhancements and the CH4-C2H6-CO slopes in Asian outflow requires increasing the east Asian anthropogenic source of CH4, and decreasing the Eurasian anthropogenic source, by at least 30% for both. The need to increase the east Asian source is driven by the underestimate of the CH4/C2H6 slope in boundary layer Chinese outflow. The Streets et al. [2003] anthropogenic emission inventory for east Asia fits this constraint by increasing CH4 emissions from that region by 40% relative to the a priori, largely because of higher livestock and landfill source estimates. Eurasian sources (mostly European) then need to be reduced by 30-50% from the a priori value of 68 Tg yr(-1). The decrease of European sources could result in part from recent mitigation of emissions from coal mining and landfills. C1 Harvard Univ, Dept Earth & Planetary Sci, Div Engn & Appl Sci, Cambridge, MA 02138 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Harvard Univ, Dept Earth & Planetary Sci, Div Engn & Appl Sci, 20 Oxford St, Cambridge, MA 02138 USA. EM xyp@io.harvard.edu; djj@io.harvard.edu; jwang@environmentaldefense.org; jal@io.harvard.edu; pip@io.harvard.edu; pns@io.harvard.edu; bmy@io.harvard.edu; glen.w.sachse@nasa.gov; drblake@uci.edu; dstreets@anl.gov RI Palmer, Paul/F-7008-2010; Yantosca, Robert/F-7920-2014 OI Yantosca, Robert/0000-0003-3781-1870 NR 65 TC 27 Z9 28 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 10 PY 2004 VL 109 IS D15 AR D15S16 DI 10.1029/2003JD004475 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 846US UT WOS:000223343200001 ER PT J AU Neumann, GA Zuber, MT Wieczorek, MA McGovern, PJ Lemoine, FG Smith, DE AF Neumann, GA Zuber, MT Wieczorek, MA McGovern, PJ Lemoine, FG Smith, DE TI Crustal structure of Mars from gravity and topography SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Review DE crustal dichotomy; impact basins; Martian crust ID ORBITER LASER ALTIMETER; MARTIAN HEMISPHERIC DICHOTOMY; X-RAY SPECTROMETER; NORTH POLAR-REGION; INTERNAL STRUCTURE; GLOBAL SURVEYOR; SNC METEORITES; IMPACT BASINS; INTERIOR STRUCTURE; THERMAL EVOLUTION AB Mars Orbiter Laser Altimeter (MOLA) topography and gravity models from 5 years of Mars Global Surveyor (MGS) spacecraft tracking provide a window into the structure of the Martian crust and upper mantle. We apply a finite-amplitude terrain correction assuming uniform crustal density and additional corrections for the anomalous densities of the polar caps, the major volcanos, and the hydrostatic flattening of the core. A nonlinear inversion for Moho relief yields a crustal thickness model that obeys a plausible power law and resolves features as small as 300 km wavelength. On the basis of petrological and geophysical constraints, we invoke a mantle density contrast of 600 kg m(-3); with this assumption, the Isidis and Hellas gravity anomalies constrain the global mean crustal thickness to be >45 km. The crust is characterized by a degree 1 structure that is several times larger than any higher degree harmonic component, representing the geophysical manifestation of the planet's hemispheric dichotomy. It corresponds to a distinction between modal crustal thicknesses of 32 km and 58 km in the northern and southern hemispheres, respectively. The Tharsis rise and Hellas annulus represent the strongest components in the degree 2 crustal thickness structure. A uniform highland crustal thickness suggests a single mechanism for its formation, with subsequent modification by the Hellas impact, erosion, and the volcanic construction of Tharsis. The largest surviving lowland impact, Utopia, postdated formation of the crustal dichotomy. Its crustal structure is preserved, making it unlikely that the northern crust was subsequently thinned by internal processes. C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Inst Phys Globe, Dept Geophys Spatiale & Planetaire, Paris, France. Lunar & Planetary Inst, Houston, TX 77058 USA. RP NASA, Goddard Space Flight Ctr, Terr Phys Lab, Code 926, Greenbelt, MD 20771 USA. EM neumann@tharsis.gsfc.nasa.gov RI Wieczorek, Mark/G-6427-2010; Lemoine, Frank/D-1215-2013; Neumann, Gregory/I-5591-2013; OI Wieczorek, Mark/0000-0001-7007-4222; Neumann, Gregory/0000-0003-0644-9944; McGovern, Patrick/0000-0001-9647-3096 NR 115 TC 192 Z9 197 U1 2 U2 26 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 AUG 10 PY 2004 VL 109 IS E8 AR E08002 DI 10.1029/2004JE002262 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 846VD UT WOS:000223344800001 ER PT J AU Qu, LW Lin, Y Hill, DE Zhou, B Wang, W Sun, XF Kitaygorodskiy, A Suarez, M Connell, JW Allard, LF Sun, YP AF Qu, LW Lin, Y Hill, DE Zhou, B Wang, W Sun, XF Kitaygorodskiy, A Suarez, M Connell, JW Allard, LF Sun, YP TI Polyimide-functionalized carbon nanotubes: Synthesis and dispersion in nanocomposite films SO MACROMOLECULES LA English DT Article ID TRANSFER RADICAL POLYMERIZATION; IN-SITU POLYMERIZATION; COMPOSITES; POLYSTYRENE; SOLUBILIZATION; SONICATION AB In the preparation of high-quality polymeric carbon nanocomposites, the full compatibility of carbon nanotubes as the filler with the matrix polymer is required. For such a purpose, an aminoterminated polyimide, specifically designed to be structurally identical to the matrix polymer, was synthesized and used in the functionalization of carbon nanotubes. The functionalized carbon nanotube samples were analyzed and studied by using a series of techniques, and the results are presented and discussed. These nanotube samples and the matrix polyimide are soluble in the same organic solvents, allowing their intimate mixing in solution and the subsequent fabrication of polyimide-carbon nanotube composite films via wet-casting. According to results from the spectroscopic and electron microscopic characterizations, the carbon nanotubes are homogeneously dispersed in the nanocomposite films. C1 Clemson Univ, Howard L Hunter Chem Lab, Dept Chem, Clemson, SC 29634 USA. NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Sun, YP (reprint author), Clemson Univ, Howard L Hunter Chem Lab, Dept Chem, Clemson, SC 29634 USA. NR 50 TC 161 Z9 165 U1 5 U2 47 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 10 PY 2004 VL 37 IS 16 BP 6055 EP 6060 DI 10.1021/ma0491006 PG 6 WC Polymer Science SC Polymer Science GA 844LP UT WOS:000223160000035 ER PT J AU Su, J Xu, TB Zhang, SJ Shrout, TR Zhang, QM AF Su, J Xu, TB Zhang, SJ Shrout, TR Zhang, QM TI An electroactive polymer-ceramic hybrid actuation system for enhanced electromechanical performance SO APPLIED PHYSICS LETTERS LA English DT Article ID POLY(VINYLIDENE FLUORIDE-TRIFLUOROETHYLENE) COPOLYMER; SINGLE-CRYSTALS; ELECTROSTRICTION AB A hybrid actuation system (HYBAS) utilizing advantages of a combination of electromechanical responses of an electrostrictive copolymer and an electroactive single crystal has been developed. The system employs the contributions of the actuation elements cooperatively. The theoretical modeling of the performances of the HYBAS is in good agreement with experimental observation. The consistency between the theoretical modeling and the experimental tests makes the design concept an effective route for tailoring and maximizing electrically driven displacement of the hybrid actuation system. (C) 2004 American Institute of Physics. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Natl Inst Aerosp, Hampton, VA 23666 USA. Penn State Univ, Inst Mat Res, University Pk, PA 16802 USA. RP Su, J (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM j.su@larc.nasa.gov NR 16 TC 25 Z9 27 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 9 PY 2004 VL 85 IS 6 BP 1045 EP 1047 DI 10.1063/1.1779341 PG 3 WC Physics, Applied SC Physics GA 843TM UT WOS:000223109500065 ER PT J AU Lillis, RJ Mitchell, DL Lin, RP Connerney, JEP Acuna, MH AF Lillis, RJ Mitchell, DL Lin, RP Connerney, JEP Acuna, MH TI Mapping crustal magnetic fields at Mars using electron reflectometry SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; LUNAR PROSPECTOR; IMPACT AB We present a kinetic model for the interaction of electrons precipitating along magnetic field lines into Mars' atmosphere and develop a technique for detecting crustal magnetic fields, which act as magnetic mirrors, reflecting some of the incident electrons back to spacecraft altitudes. We present an initial map covering 20% of the planet, which shows the topology of magnetic sources along the dichotomy boundary and reveals new magnetic sources in the northern lowlands, implying the existence of preserved Noachian crust beneath at least some regions of the apparently young plains. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Lillis, RJ (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM rlillis@ssl.berkeley.edu RI connerney, john/I-5127-2013; Lillis, Robert/A-3281-2008 OI Lillis, Robert/0000-0003-0578-517X NR 23 TC 27 Z9 27 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 AUG 7 PY 2004 VL 31 IS 15 AR L15702 DI 10.1029/2004GL020189 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 846SD UT WOS:000223335600003 ER PT J AU Liu, ZY Vaughan, MA Winker, DM Hostetler, CA Poole, LR Hlavka, D Hart, W McGill, M AF Liu, ZY Vaughan, MA Winker, DM Hostetler, CA Poole, LR Hlavka, D Hart, W McGill, M TI Use of probability distribution functions for discriminating between cloud and aerosol in lidar backscatter data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE scene classification; cloud and aerosol discrimination; space lidar ID ASIAN DUST; POLARIZATION LIDAR; OPTICAL-PROPERTIES; DEPOLARIZATION; EVENTS; CIRRUS; RATIO AB In this paper, we describe the algorithm that will be used during the upcoming Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission for discriminating between clouds and aerosols detected in two-wavelength backscatter lidar profiles. We first analyze single-test and multiple-test classification approaches based on one-dimensional (1-D) and multidimensional probability distribution functions (PDFs) in the context of a two-class feature identification scheme. From these studies we derive an operational algorithm. This algorithm is a 3-D approach utilizing the layer mean attenuated backscatter at 532 nm, the layer-integrated 1064-nm to 532-nm volume color ratio, and the midlayer altitude. A data set acquired by the Cloud Physics Lidar (CPL) is used to test the algorithm. Comparisons are conducted between the 3-D CALIPSO algorithm results and those derived from an existing 2-D algorithm. The results obtained show generally good agreement between the two methods. However, of a total of 228,264 layers analyzed, similar to5.7% are classified as different types by the two algorithms. This disparity is shown to be due largely to the misclassification of optically thin clouds as aerosols by the 2-D algorithm. The use of 3-D PDFs in the CALIPSO algorithm is found to significantly reduce this type of error because the separation between cloud and aerosol clusters is more complete in this 3-D space. Dust presents a special case. Because the intrinsic scattering properties of dust layers can be very similar to those of clouds, additional algorithm testing was performed using an optically dense layer of Saharan dust measured during the Lidar In-space Technology Experiment (LITE). In general, the method is shown to distinguish reliably between dust layers and clouds. The relatively few erroneous classifications that occurred most often in the analysis of the LITE data occurred in those regions of the Saharan dust layer where the optical thickness was the highest. C1 Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. Sci Applicat Int Corp, Hampton, VA USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sci Syst & Applicat Inc, Greenbelt, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Liu, ZY (reprint author), Hampton Univ, Ctr Atmospher Sci, 23 Tyler St, Hampton, VA 23668 USA. EM z.liu@larc.nasa.gov; ma.vaughan@larc.nasa.gov; d.m.winker@larc.nasa.gov; c.a.hostetler@larc.nasa.gov; l.r.poole@larc.nasa.gov; sgdlh@virl.gsfc.nasa.gov; billhart@virl.gsfc.nasa.gov; mcgill@virl.gsfc.nasa.gov RI Liu, Zhaoyan/A-9604-2009; Liu, Zhaoyan/B-1783-2010; McGill, Matthew/D-8176-2012 OI Liu, Zhaoyan/0000-0003-4996-5738; NR 30 TC 82 Z9 86 U1 3 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 7 PY 2004 VL 109 IS D15 AR D15202 DI 10.1029/2004JD004732 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 846SM UT WOS:000223336600006 ER PT J AU Santee, ML Manney, GL Livesey, NJ Read, WG AF Santee, ML Manney, GL Livesey, NJ Read, WG TI Three-dimensional structure and evolution of stratospheric HNO3 based on UARS Microwave Limb Sounder measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Microwave Limb Sounder (MLS); Upper Atmosphere Research Satellite (UARS); nitric acid (HNO3); denitrification; polar processes; stratospheric chemistry ID CRYOGENIC INFRARED SPECTROMETERS; WAVE SPECTROSCOPIC MEASUREMENTS; ATMOSPHERE RESEARCH SATELLITE; POLAR VORTEX; POAM-II; MIDDLE ATMOSPHERE; MILLIMETER-WAVE; NITRIC-ACID; SAGE-II; MODEL-CALCULATIONS AB The Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) measured the global distribution of stratospheric HNO3 through more than seven complete annual cycles in both hemispheres. Here we present an overview of the seasonal, interhemispheric, and interannual variations in the distribution of HNO3 throughout the lower and middle stratosphere from 420 to 960 K potential temperature based on the UARS MLS version 6 HNO3 measurements. The version 6 MLS data have much better precision and a larger vertical range than previous MLS HNO3 data sets and have also been corrected to account for an oversight in the retrieval algorithms that led earlier versions to overestimate HNO3 abundances by as much as 35% at some levels in the stratosphere. HNO3 exhibits little vertical, seasonal, or interannual variability in the tropics. For the first similar to1.5 years of the mission, however, a persistent enhancement is seen at low and middle latitudes that we attribute to perturbations in reactive nitrogen chemistry under conditions of high aerosol loading from the eruption of Mount Pinatubo. The signature of Pinatubo-induced HNO3 enhancement is considerably weaker at 420 and 465 K than it is at higher altitudes, and it is also considerably weaker at northern middle and high latitudes than it is in the Southern Hemisphere. HNO3 abundances increase toward the pole in both hemispheres at all levels and in all seasons, with the exception of the severely denitrified region inside the Antarctic vortex. A pronounced seasonal cycle is present at middle and high latitudes up to at least 960 K (similar to34 km), with a winter maximum and a summer minimum. Large interannual variability in the timing, magnitude, and duration of enhanced wintertime HNO3 abundances is seen in both hemispheres. Even in the coldest Arctic winters, HNO3 depletion is modest and limited in both horizontal and vertical extent. In contrast, virtually complete removal of gas-phase HNO3 occurs at the highest southern latitudes by July in every year throughout the lower stratosphere. Indications of denitrification are present up to at least 740 K, well above the highest altitude at which dehydration is observed, providing further evidence that denitrification can proceed in the absence of dehydration. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA. RP Santee, ML (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-701,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mls@mls.jpl.nasa.gov NR 81 TC 38 Z9 38 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 7 PY 2004 VL 109 IS D15 AR D15306 DI 10.1029/2004JD004578 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 846SM UT WOS:000223336600005 ER PT J AU Tsurutani, B Mannucci, A Iijima, B Abdu, MA Sobral, JHA Gonzalez, W Guarnieri, F Tsuda, T Saito, A Yumoto, K Fejer, B Fuller-Rowell, TJ Kozyra, J Foster, JC Coster, A Vasyliunas, VM AF Tsurutani, B Mannucci, A Iijima, B Abdu, MA Sobral, JHA Gonzalez, W Guarnieri, F Tsuda, T Saito, A Yumoto, K Fejer, B Fuller-Rowell, TJ Kozyra, J Foster, JC Coster, A Vasyliunas, VM TI Global dayside ionospheric uplift and enhancement associated with interplanetary electric fields SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE solar wind-ionosphere coupling; magnetosphere ionosphere coupling; magnetic storms; ionosphere ID DISTURBANCE DYNAMO; MAGNETIC STORMS; MAGNETOSPHERIC CONVECTION; EQUATORIAL IONOSPHERE; LOW LATITUDES; SUBSTORMS; SYSTEM; SECTOR; WIND; PRECIPITATION AB The interplanetary shock/electric field event of 5-6 November 2001 is analyzed using ACE interplanetary data. The consequential ionospheric effects are studied using GPS receiver data from the CHAMP and SAC-C satellites and altimeter data from the TOPEX/Poseidon satellite. Data from similar to100 ground-based GPS receivers as well as Brazilian Digisonde and Pacific sector magnetometer data are also used. The dawn-to-dusk interplanetary electric field was initially similar to33 mV/m just after the forward shock (IMF B(Z)=-48 nT) and later reached a peak value of similar to54 mV/m 1 hour and 40 min later (B(Z)=-78 nT). The electric field was similar to45 mV/m (B(Z)=-65 nT) 2 hours after the shock. This electric field generated a magnetic storm of intensity D(ST)=-275 nT. The dayside satellite GPS receiver data plus ground-based GPS data indicate that the entire equatorial and midlatitude (up to +/-50degrees magnetic latitude (MLAT)) dayside ionosphere was uplifted, significantly increasing the electron content (and densities) at altitudes greater than 430 km (CHAMP orbital altitude). This uplift peaked similar to2 1/2 hours after the shock passage. The effect of the uplift on the ionospheric total electron content (TEC) lasted for 4 to 5 hours. Our hypothesis is that the interplanetary electric field "promptly penetrated'' to the ionosphere, and the dayside plasma was convected (by E x B) to higher altitudes. Plasma upward transport/convergence led to a similar to55-60% increase in equatorial ionospheric TEC to values above similar to430 km (at 1930 LT). This transport/convergence plus photoionization of atmospheric neutrals at lower altitudes caused a 21% TEC increase in equatorial ionospheric TEC at similar to1400 LT (from ground-based measurements). During the intense electric field interval, there was a sharp plasma "shoulder'' detected at midlatitudes by the GPS receiver and altimeter satellites. This shoulder moves equatorward from -54degrees to -37degrees MLAT during the development of the main phase of the magnetic storm. We presume this to be an ionospheric signature of the plasmapause and its motion. The total TEC increase of this shoulder is similar to80%. Part of this increase may be due to a "superfountain effect.'' The dayside ionospheric TEC above similar to430 km decreased to values similar to45% lower than quiet day values 7 to 9 hours after the beginning of the electric field event. The total equatorial ionospheric TEC decrease was similar to16%. This decrease occurred both at midlatitudes and at the equator. We presume that thermospheric winds and neutral composition changes produced by the storm-time Joule heating, disturbance dynamo electric fields, and electric fields at auroral and subauroral latitudes are responsible for these decreases. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Inst Nacl Pesquisas Espaciais, BR-12245970 Sao Jose Dos Campos, Brazil. Kyoto Univ, Res Inst Sustainable Humanosphere, Kyoto 6110011, Japan. Kyoto Univ, Dept Geophys, Kyoto 6068502, Japan. Kyushu Univ, Space Environm Res Ctr, Fukuoka 8128581, Japan. Utah State Univ, Ctr Atmospher & Space Sci, Logan, UT 84322 USA. Space Environm Ctr, Boulder, CO 80305 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. MIT, Haystack Observ, Westford, MA 01886 USA. Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. RP Tsurutani, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM tim.fuller-rowell@noaa.gov; anthony.mannucci@jpl.nasa.gov; byron.iijima@jpl.nasa.gov; abdu@dae.inpe.br; sobral@dae.inpe.br; gonzalez@dge.inpe.br; guarnier@dge.inpe.br; tsuda@kurasc.kyoto-u.ac.jp; saitoua@kugi.kyoto-u.ac.jp; yumoto@serc.kyushu-u.ac.jp; bfejer@cc.usu.edu; tim.fuller-rowell@noaa.gov; jcf@haystack.mit.edu; ajc@haystack.mit.edu; vasyliunas@linmpi.mpg.de RI Mannucci, Anthony/A-1349-2007; tsuda, toshitaka/A-3035-2015; U-ID, Kyushu/C-5291-2016 OI Mannucci, Anthony/0000-0003-2391-8490; NR 44 TC 203 Z9 203 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 7 PY 2004 VL 109 IS A8 AR A08302 DI 10.1029/2003JA010342 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 846TT UT WOS:000223340100001 ER PT J AU Chiu, JYC Marshak, A Wiscombe, WJ AF Chiu, JYC Marshak, A Wiscombe, WJ TI The effect of surface heterogeneity on cloud absorption estimates SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID COLLOCATED AIRCRAFT MEASUREMENTS; SOLAR RADIATIVE-TRANSFER; DISCRETE-ORDINATE-METHOD; ATMOSPHERE; INHOMOGENEITY; ARESE AB This study presents a systematic and quantitative analysis of the effect of inhomogeneous surface albedo on shortwave cloud absorption estimates. We used 3D radiative transfer modeling over a checkerboard surface albedo to calculate cloud absorption. We have found that accounting for surface heterogeneity enhances cloud absorption. However, the enhancement is not sufficient to explain the reported difference between measured and modeled cloud absorption. C1 Univ Maryland Baltimore Cty, JCET, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. NASA, Climate & Radiat Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Chiu, JYC (reprint author), Univ Maryland Baltimore Cty, JCET, Joint Ctr Earth Syst Technol, 1000 Hilltop Circle, Baltimore, MD 21250 USA. EM cchiu@climate.gsfc.nasa.gov RI Wiscombe, Warren/D-4665-2012; Chiu, Christine/E-5649-2013; Marshak, Alexander/D-5671-2012 OI Wiscombe, Warren/0000-0001-6844-9849; Chiu, Christine/0000-0002-8951-6913; NR 17 TC 6 Z9 6 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 6 PY 2004 VL 31 IS 15 AR L15105 DI 10.1029/2004GL020104 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 846SC UT WOS:000223335500001 ER PT J AU Swingle, MR Honkanen, RE Ciszak, EM AF Swingle, MR Honkanen, RE Ciszak, EM TI Structural basis for the catalytic activity of human serine/threonine protein phosphatase-5 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID TETRATRICOPEPTIDE REPEAT DOMAIN; PURPLE ACID-PHOSPHATASE; BINUCLEAR METAL CENTER; CRYSTAL-STRUCTURE; MUTATIONAL ANALYSIS; TRANSITION-STATE; CALCINEURIN; SUBUNIT; IDENTIFICATION; PHOSPHORYL AB Serine/threonine protein phosphatase-5 (PP5) affects many signaling networks that regulate cell growth and cellular responses to stress. Here we report the crystal structure of the PP5 catalytic domain (PP5c) at a resolution of 1.6 Angstrom. From this structure we propose a mechanism for PP5-mediated hydrolysis of phosphoprotein substrates, which requires the precise positioning of two metal ions within a conserved Asp(271)-M-1: M-2-W-1-His(427)-His(304)-Asp(274) catalytic motif (where M-1 and M-2 are metals and W-1 is a water molecule). The structure of PP5c provides a structural basis for explaining the exceptional catalytic proficiency of protein phosphatases, which are among the most powerful known catalysts. Resolution of the entire C terminus revealed a novel subdomain, and the structure of the PP5c should also aid development of type-specific inhibitors. C1 NASA, George C Marshall Space Flight Ctr, Biol & Phys Space Res Lab, Huntsville, AL 35812 USA. Univ S Alabama, Coll Med, Dept Biochem & Mol Biol, Mobile, AL 36688 USA. Univ Alabama, Struct Biol Lab, Huntsville, AL 35812 USA. RP Ciszak, EM (reprint author), NASA, George C Marshall Space Flight Ctr, Biol & Phys Space Res Lab, Huntsville, AL 35812 USA. EM ewa.m.ciszak@nasa.gov FU NCI NIH HHS [CA 60750, R01 CA060750]; NHLBI NIH HHS [HL 59154] NR 70 TC 65 Z9 66 U1 1 U2 5 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD AUG 6 PY 2004 VL 279 IS 32 BP 33992 EP 33999 DI 10.1074/jbc.M402855200 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 842YD UT WOS:000223039700110 PM 15155720 ER PT J AU Yurganov, LN Blumenstock, T Grechko, EI Hase, F Hyer, EJ Kasischke, ES Koike, M Kondo, Y Kramer, I Leung, FY Mahieu, E Mellqvist, J Notholt, J Novelli, PC Rinsland, CP Scheel, HE Schulz, A Strandberg, A Sussmann, R Tanimoto, H Velazco, V Zander, R Zhao, Y AF Yurganov, LN Blumenstock, T Grechko, EI Hase, F Hyer, EJ Kasischke, ES Koike, M Kondo, Y Kramer, I Leung, FY Mahieu, E Mellqvist, J Notholt, J Novelli, PC Rinsland, CP Scheel, HE Schulz, A Strandberg, A Sussmann, R Tanimoto, H Velazco, V Zander, R Zhao, Y TI A quantitative assessment of the 1998 carbon monoxide emission anomaly in the Northern Hemisphere based on total column and surface concentration measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE carbon monoxide; forest fires; spectroscopy ID BOREAL FOREST-FIRES; FREE TROPOSPHERIC CO; SPECTROSCOPIC MEASUREMENTS; INTERANNUAL VARIABILITY; INFRARED MEASUREMENTS; HIGH-RESOLUTION; CHEMISTRY; SIBERIA; C2H6; HCN AB Carbon monoxide abundances in the atmosphere have been measured between January 1996 and December 2001 in the high Northern Hemisphere (HNH) (30degrees-90degreesN) using two different approaches: total column amounts of CO retrieved from infrared solar spectra and CO mixing ratios measured in situ at ground-based stations. The data were averaged, and anomalies of the CO HNH burden ( deviations of the total tropospheric mass between 30degreesN and 90degreesN from the mean seasonal profile, determined as the 5 year average) were analyzed. The anomalies obtained from in situ and total column data agree well and both show two maxima, by far the largest in October 1998 and a lower one in August 1996. A noticeable decrease of the positive 1998 summer anomaly with increasing height was found. A box model was applied, and anomalies in source rates were obtained under the assumption of insignificant interannual sink variations. In August 1998 the HNH emission anomaly was estimated to be 38 Tg month(-1). The annual 1998 emission positive anomaly was 96 Tg yr(-1). Nearly all excess CO may be attributed to the emissions from boreal forest fires. According to available inventories, biomass burning emits around 52 Tg yr(-1) during the "normal'' years; therefore total biomass emissions in 1998 were as large as 148 Tg yr(-1). In August 1998, CO contribution from the biomass burning was twice as large as that from fossil fuel combustion. The results were compared to available emission inventories. C1 Japan Agcy Marine Earth Sci & Technol, Frontier Res Syst Global Change, Yokohama, Kanagawa 2360001, Japan. Forschungszentrum Karlsruhe, Inst Meteorol & Climate Res, IMK ISF, D-76021 Karlsruhe, Germany. Obukhov Inst Atmospher Phys, Moscow 109017, Russia. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. Univ Tokyo, Bunkyo Ku, Tokyo 1130033, Japan. Harvard Univ, Dept Earth & Planetary Sci, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Univ Liege, Inst Astrophys & Geophys, B-4000 Liege, Belgium. Chalmers, S-41296 Gothenburg, Sweden. Alfred Wegener Inst Polar & Marine Res, D-14473 Potsdam, Germany. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. NASA, Div Atmospher Sci, Langley Res Ctr, Hampton, VA 23681 USA. Forschungszentrum Karlsruhe, Inst Meteorol & Climate Res, IMK IFU, D-82467 Garmisch Partenkirchen, Germany. Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan. Univ Bremen, D-28359 Bremen, Germany. Univ Calif Davis, Davis, CA 95616 USA. RP Japan Agcy Marine Earth Sci & Technol, Frontier Res Syst Global Change, 3173-25 Showa Machi, Yokohama, Kanagawa 2360001, Japan. RI Tanimoto, Hiroshi/E-6779-2010; Koike, Makoto/F-4366-2011; Velazco, Voltaire/H-2280-2011; Blumenstock, Thomas/K-2263-2012; Sussmann, Ralf/K-3999-2012; Hase, Frank/A-7497-2013; Garmisch-Pa, Ifu/H-9902-2014; Hyer, Edward/E-7734-2011; Notholt, Justus/P-4520-2016 OI Tanimoto, Hiroshi/0000-0002-5424-9923; Velazco, Voltaire/0000-0002-1376-438X; Hyer, Edward/0000-0001-8636-2026; Notholt, Justus/0000-0002-3324-885X NR 46 TC 50 Z9 51 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 6 PY 2004 VL 109 IS D15 AR D15305 DI 10.1029/2004JD004559 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 846SL UT WOS:000223336400002 ER PT J AU Biemont, E Derkatch, A Lundin, P Mannervik, S Norlin, LO Rostohar, D Royen, P Palmeri, P Schef, P AF Biemont, E Derkatch, A Lundin, P Mannervik, S Norlin, LO Rostohar, D Royen, P Palmeri, P Schef, P TI Importance of an M2 depopulating channel for a KrII metastable state SO PHYSICAL REVIEW LETTERS LA English DT Article ID STORED ION-BEAM; TRANSITION-PROBABILITIES; ISOELECTRONIC SEQUENCE; RADIATIVE LIFETIME; FORBIDDEN LINES; CONFIGURATION; EXCITATION AB An experimental investigation of the radiative lifetime of the metastable 4s(2)4p(4)(P-3)4d D-4(7/2) level in Kr II shows an unusual situation regarding the importance of an M2 depopulation channel. While the first order M1 and E2 channels are expected to contribute in a dominant way to the decay, the experimental result, obtained using a laser probing technique on a stored ion beam, tau=0.57+/-0.03 s, is far too short to be due to these channels according to our relativistic multiconfiguration Dirac-Fock calculation. Only if second order contributions to the decay branches (including essentially the M2 contribution) are taken into account in the calculations could the unexpected short lifetime be explained. C1 Univ Liege, IPNAS, B-4000 Liege 1, Belgium. Univ Mons, B-7000 Mons, Belgium. Univ Stockholm, Dept Phys, S-10691 Stockholm, Sweden. Royal Inst Technol, Dept Phys, S-10691 Stockholm, Sweden. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Biemont, E (reprint author), Univ Liege, IPNAS, Batiment B 15, B-4000 Liege 1, Belgium. RI Rostohar, Danijela/G-9994-2014 NR 20 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 6 PY 2004 VL 93 IS 6 AR 063003 DI 10.1103/PhysRevLett.93.063003 PG 4 WC Physics, Multidisciplinary SC Physics GA 844DS UT WOS:000223138200014 PM 15323626 ER PT J AU Squyres, SW Arvidson, RE Bell, JF Bruckner, J Cabrol, NA Calvin, W Carr, MH Christensen, PR Clark, BC Crumpler, L Des Marais, DJ d'Uston, C Economou, T Farmer, J Farrand, W Folkner, W Golombek, M Gorevan, S Grant, JA Greeley, R Grotzinger, J Haskin, L Herkenhoff, KE Hviid, S Johnson, J Klingelhofer, G Knoll, A Landis, G Lemmon, M Li, R Madsen, MB Malin, MC McLennan, SM McSween, HY Ming, DW Moersch, J Morris, RV Parker, T Rice, JW Richter, L Rieder, R Sims, M Smith, M Smith, P Soderblom, LA Sullivan, R Wanke, H Wdowiak, T Wolff, M Yen, A AF Squyres, SW Arvidson, RE Bell, JF Bruckner, J Cabrol, NA Calvin, W Carr, MH Christensen, PR Clark, BC Crumpler, L Des Marais, DJ d'Uston, C Economou, T Farmer, J Farrand, W Folkner, W Golombek, M Gorevan, S Grant, JA Greeley, R Grotzinger, J Haskin, L Herkenhoff, KE Hviid, S Johnson, J Klingelhofer, G Knoll, A Landis, G Lemmon, M Li, R Madsen, MB Malin, MC McLennan, SM McSween, HY Ming, DW Moersch, J Morris, RV Parker, T Rice, JW Richter, L Rieder, R Sims, M Smith, M Smith, P Soderblom, LA Sullivan, R Wanke, H Wdowiak, T Wolff, M Yen, A TI The Spirit Rover's Athena Science Investigation at Gusev Crater, Mars SO SCIENCE LA English DT Article ID MAGNETIC-PROPERTIES EXPERIMENTS; X-RAY SPECTROMETER; MOSSBAUER SPECTROMETER; EXPLORATION ROVERS; MICROSCOPIC IMAGER; LANDING SITES; ART.; ROCKS; MISSION; FEATURES AB The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former lake, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt, and the dominant geologic processes are impact events and eolian transport. Many rocks exhibit coatings and other characteristics that may be evidence for minor aqueous alteration. Any lacustrine sediments that may exist at this location within Gusev apparently have been buried by lavas that have undergone subsequent impact disruption. C1 Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Max Planck Inst Chem, Abt Kosmochem, D-55128 Mainz, Germany. NASA, Ames SETI Inst, Moffett Field, CA 94035 USA. Univ Nevada, Dept Geol Sci, Reno, NV 89557 USA. US Geol Survey, Menlo Pk, CA 94025 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Lockheed Martin Corp, Littleton, CO 80127 USA. New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Space Sci Inst, Boulder, CO 80301 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Honeybee Robot, New York, NY 10012 USA. Smithsonian Inst, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. Johannes Gutenberg Univ Mainz, D-55099 Mainz, Germany. Harvard Univ, Bot Museum, Cambridge, MA 02138 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA. Niels Bohr Inst, DK-2100 Copenhagen 0, Denmark. Malin Space Sci Syst, San Diego, CA 92191 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Deutsch Zentrum Luft & Raumfahrt, Inst Raumsimulat, D-51170 Cologne, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Alabama Birmingham, Dept Phys, Birmingham, AL 35294 USA. Space Sci Inst, Martinez, GA 30907 USA. RP Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. EM squyres@astro.cornell.edu RI Lemmon, Mark/E-9983-2010; Moersch, Jeffrey/F-7189-2010; Smith, Michael/C-8875-2012; Madsen, Morten/D-2082-2011 OI Lemmon, Mark/0000-0002-4504-5136; Madsen, Morten/0000-0001-8909-5111 NR 32 TC 237 Z9 241 U1 4 U2 48 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 794 EP 799 DI 10.1126/science.3050794 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900031 PM 15297657 ER PT J AU Bell, JF Squyres, SW Arvidson, RE Arneson, HM Bass, D Blaney, D Cabrol, N Calvin, W Farmer, J Farrand, WH Goetz, W Golombek, M Grant, JA Greeley, R Guinness, E Hayes, AG Hubbard, MYH Herkenhoff, KE Johnson, MJ Johnson, JR Joseph, J Kinch, KM Lemmon, MT Li, R Madsen, MB Maki, JN Malin, M McCartney, E McLennan, S McSween, HY Ming, DW Moersch, JE Morris, RV Dobrea, EZN Parker, TJ Proton, J Rice, JW Seelos, F Soderblom, J Soderblom, LA Sohl-Dickstein, JN Sullivan, RJ Wolff, MJ Wang, A AF Bell, JF Squyres, SW Arvidson, RE Arneson, HM Bass, D Blaney, D Cabrol, N Calvin, W Farmer, J Farrand, WH Goetz, W Golombek, M Grant, JA Greeley, R Guinness, E Hayes, AG Hubbard, MYH Herkenhoff, KE Johnson, MJ Johnson, JR Joseph, J Kinch, KM Lemmon, MT Li, R Madsen, MB Maki, JN Malin, M McCartney, E McLennan, S McSween, HY Ming, DW Moersch, JE Morris, RV Dobrea, EZN Parker, TJ Proton, J Rice, JW Seelos, F Soderblom, J Soderblom, LA Sohl-Dickstein, JN Sullivan, RJ Wolff, MJ Wang, A TI Pancam multispectral imaging results from the Spirit Rover at Gusev crater SO SCIENCE LA English DT Article ID PATHFINDER LANDING SITE; MARS-PATHFINDER; REFLECTANCE SPECTRA; SOLAR-SYSTEM; DUST; MINERALOGY; ABUNDANCE AB Panoramic Camera images at Gusev crater reveal a rock-strewn surface interspersed with high-to moderate-albedo fine-grained deposits occurring in part as drifts or in small circular swales or hollows. Optically thick coatings of fine-grained ferric iron-rich dust dominate most bright soil and rock surfaces. Spectra of some darker rock surfaces and rock regions exposed by brushing or grinding show near-infrared spectral signatures consistent with the presence of mafic silicates such as pyroxene or olivine. Atmospheric observations show a steady decline in dust opacity during the mission, and astronomical observations captured solar transits by the martian moons, Phobos and Deimos, as well as a view of Earth from the martian surface. C1 Cornell Univ, Ithaca, NY 14853 USA. Washington Univ, St Louis, MO 63130 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Search Extraterr Intelligence Inst, Moffett Field, CA 94035 USA. Univ Nevada, Reno, NV 89501 USA. Arizona State Univ, Tempe, AZ 85287 USA. Space Sci Inst, Boulder, CO 80301 USA. Univ Copenhagen, DK-2100 Copenhagen O, Denmark. Smithsonian Inst, Natl Air & Space Museum, Washington, DC 20560 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Aarhus Univ, DK-8000 Aarhus C, Denmark. Texas A&M Univ, College Stn, TX 77843 USA. Ohio State Univ, Columbus, OH 43210 USA. Malin Space Sci Syst Inc, San Diego, CA 92191 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Univ Tennessee, Knoxville, TN 37996 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Bell, JF (reprint author), Cornell Univ, Ithaca, NY 14853 USA. EM jfb8@cornell.edu RI Lemmon, Mark/E-9983-2010; Moersch, Jeffrey/F-7189-2010; Madsen, Morten/D-2082-2011; Hayes, Alexander/P-2024-2014; Kinch, Kjartan/C-5742-2015; Johnson, Jeffrey/F-3972-2015; Seelos, Frank/C-7875-2016; OI Lemmon, Mark/0000-0002-4504-5136; Madsen, Morten/0000-0001-8909-5111; Hayes, Alexander/0000-0001-6397-2630; Kinch, Kjartan/0000-0002-4629-8880; Seelos, Frank/0000-0001-9721-941X; Soderblom, Jason/0000-0003-3715-6407 NR 34 TC 108 Z9 108 U1 4 U2 14 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 800 EP 806 DI 10.1126/science.1100175 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900032 PM 15297658 ER PT J AU Grant, JA Arvidson, R Bell, JF Cabrol, NA Carr, MH Christensen, P Crumpler, L Des Marais, DJ Ehlmann, BL Farmer, J Golombek, M Grant, FD Greeley, R Herkenhoff, K Li, R McSween, HY Ming, DW Moersch, J Rice, JW Ruff, S Richter, L Squyres, S Sullivan, R Weitz, C AF Grant, JA Arvidson, R Bell, JF Cabrol, NA Carr, MH Christensen, P Crumpler, L Des Marais, DJ Ehlmann, BL Farmer, J Golombek, M Grant, FD Greeley, R Herkenhoff, K Li, R McSween, HY Ming, DW Moersch, J Rice, JW Ruff, S Richter, L Squyres, S Sullivan, R Weitz, C TI Surficial deposits at Gusev crater along Spirit Rover traverses SO SCIENCE LA English DT Article ID SIZE-FREQUENCY DISTRIBUTIONS; MAADIM-VALLIS; LANDING SITES; MARS; EROSION; ROCKS AB The Mars Exploration Rover Spirit has traversed a fairly flat, rock-strewn terrain whose surface is shaped primarily by impact events, although some of the landscape has been altered by eolian processes. Impacts ejected basaltic rocks that probably were part of locally formed lava flows from at least 10 meters depth. Some rocks have been textured and/or partially buried by windblown sediments less than 2 millimeters in diameter that concentrate within shallow, partially filled, circular impact depressions referred to as hollows. The terrain traversed during the 90-sol (martian solar day) nominal mission shows no evidence for an ancient lake in Gusev crater. C1 Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, SETI Inst, Div Space Sci, Moffett Field, CA 94035 USA. US Geol Survey, Menlo Pk, CA 94025 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. DLR, Inst Space Simulat, D-51170 Cologne, Germany. NASA Headquarters, Washington, DC 20560 USA. RP Grant, JA (reprint author), Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. EM grantj@nasm.si.edu RI Moersch, Jeffrey/F-7189-2010 NR 30 TC 53 Z9 53 U1 1 U2 4 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 807 EP 810 DI 10.1126/science.1099849 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900033 PM 15297659 ER PT J AU Greeley, R Squyres, SW Arvidson, RE Bartlett, P Bell, JF Blaney, D Cabrol, NA Farmer, J Farrand, B Golombek, MP Gorevan, SP Grant, JA Haldemann, AFC Herkenhoff, KE Johnson, J Landis, G Madsen, MB McLennan, SM Moersch, J Rice, JW Richter, L Ruff, S Sullivan, RJ Thompson, SD Wang, A Weitz, CM Whelley, P AF Greeley, R Squyres, SW Arvidson, RE Bartlett, P Bell, JF Blaney, D Cabrol, NA Farmer, J Farrand, B Golombek, MP Gorevan, SP Grant, JA Haldemann, AFC Herkenhoff, KE Johnson, J Landis, G Madsen, MB McLennan, SM Moersch, J Rice, JW Richter, L Ruff, S Sullivan, RJ Thompson, SD Wang, A Weitz, CM Whelley, P CA Athena Sci Team TI Wind-related processes detected by the Spirit rover at Gusev Crater, Mars SO SCIENCE LA English DT Article ID PATHFINDER LANDING SITE; SURFACES; ABRASION C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Cornell Univ, Dept Astron, Ithaca, NY USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63031 USA. Honeybee Robot, New York, NY 10012 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Colorado, Space Sci Inst, Boulder, CO 80301 USA. Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Univ Copenhagen, Niels Bohr Inst Astron Phys & Geophys, Ctr Planetary Sci, DK-2100 Copenhagen, Denmark. Univ Copenhagen, Orsted Lab, DK-2100 Copenhagen, Denmark. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. Deutsch Zentrum Luft & Raumfart, German Aerosp Ctr, Inst Space Simulat, D-51170 Cologne, Germany. NASA, Washington, DC 20546 USA. RP Greeley, R (reprint author), Arizona State Univ, Dept Geol Sci, Box 871404, Tempe, AZ 85287 USA. EM Greeley@asu.edu RI Moersch, Jeffrey/F-7189-2010; Whelley, Patrick/B-9560-2012; Madsen, Morten/D-2082-2011 OI Whelley, Patrick/0000-0003-3266-9772; Madsen, Morten/0000-0001-8909-5111 NR 33 TC 66 Z9 66 U1 0 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 810 EP + DI 10.1126/science.1100108 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900034 PM 15297660 ER PT J AU Arvidson, RE Anderson, RC Bartlett, P Bell, JF Blaney, D Christensen, PR Chu, P Crumpler, L Davis, K Ehlmann, BL Fergason, R Golombek, MP Gorevan, S Grant, JA Greeley, R Guinness, EA Haldemann, AFC Herkenhoff, K Johnson, J Landis, G Li, R Lindemann, R McSween, H Ming, DW Myrick, T Richter, L Seelos, FP Squyres, SW Sullivan, RJ Wang, A Wilson, J AF Arvidson, RE Anderson, RC Bartlett, P Bell, JF Blaney, D Christensen, PR Chu, P Crumpler, L Davis, K Ehlmann, BL Fergason, R Golombek, MP Gorevan, S Grant, JA Greeley, R Guinness, EA Haldemann, AFC Herkenhoff, K Johnson, J Landis, G Li, R Lindemann, R McSween, H Ming, DW Myrick, T Richter, L Seelos, FP Squyres, SW Sullivan, RJ Wang, A Wilson, J TI Localization and physical properties experiments conducted by Spirit at Gusev crater SO SCIENCE LA English DT Article ID PATHFINDER AB The precise location and relative elevation of Spirit during its traverses from the Columbia Memorial station to Bonneville crater were determined with bundle-adjusted retrievals from rover wheel turns, suspension and tilt angles, and overlapping images. Physical properties experiments show a decrease of 0.2% per Mars solar day in solar cell output resulting from deposition of airborne dust, cohesive soil-like deposits in plains and hollows, bright and dark rock coatings, and relatively weak volcanic rocks of basaltic composition. Volcanic, impact, aeolian, and water-related processes produced the encountered landforms and materials. C1 Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Honeybee Robot, New York, NY 10012 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA. Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. US Geol Survey, Flagstaff, AZ 86001 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Deutsch Luft & Raumfahrt Inst Raumsimulat, D-51170 Cologne, Germany. RP Arvidson, RE (reprint author), Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. RI Seelos, Frank/C-7875-2016 OI Seelos, Frank/0000-0001-9721-941X NR 10 TC 104 Z9 108 U1 1 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 821 EP 824 DI 10.1126/science.1099922 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900035 PM 15297662 ER PT J AU Herkenhoff, KE Squyres, SW Arvidson, R Bass, DS Bell, JF Bertelsen, P Cabrol, NA Gaddis, L Hayes, AG Hviid, SF Johnson, JR Kinch, KM Madsen, MB Maki, JN McLennan, SM McSween, HY Rice, JW Sims, M Smith, PH Soderblom, LA Spanovich, N Sullivan, R Wang, A AF Herkenhoff, KE Squyres, SW Arvidson, R Bass, DS Bell, JF Bertelsen, P Cabrol, NA Gaddis, L Hayes, AG Hviid, SF Johnson, JR Kinch, KM Madsen, MB Maki, JN McLennan, SM McSween, HY Rice, JW Sims, M Smith, PH Soderblom, LA Spanovich, N Sullivan, R Wang, A TI Textures of the soils and rocks at Gusev crater from Spirit's Microscopic Imager SO SCIENCE LA English DT Article ID ROVER; MARS; SPECTROMETER AB The Microscopic Imager on the Spirit rover analyzed the textures of the soil and rocks at Gusev crater on Mars at a resolution of 100 micrometers. Weakly bound agglomerates of dust are present in the soil near the Columbia Memorial Station. Some of the brushed or abraded rock surfaces show igneous textures and evidence for alteration rinds, coatings, and veins consistent with secondary mineralization. The rock textures are consistent with a volcanic origin and subsequent alteration and/or weathering by impact events, wind, and possibly water. C1 US Geol Survey, Astrogeol Team, Flagstaff, AZ 86001 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Washington Univ, Dept Earth & Space Sci, St Louis, MO 63130 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Copenhagen, Danish Space Res Inst, Ctr Planetary Sci, DK-1168 Copenhagen, Denmark. Univ Copenhagen, Niels Bohr Inst Astron Phys & Geophys, DK-1168 Copenhagen, Denmark. NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. Aarhus Univ, Inst Phys & Astron, Aarhus, Denmark. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Washington Univ, Dept Earth & Space Sci, St Louis, MO 63130 USA. Washington Univ, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. RP US Geol Survey, Astrogeol Team, Flagstaff, AZ 86001 USA. EM kherkenhoff@usgs.gov RI Madsen, Morten/D-2082-2011; Hayes, Alexander/P-2024-2014; Kinch, Kjartan/C-5742-2015; Johnson, Jeffrey/F-3972-2015 OI Madsen, Morten/0000-0001-8909-5111; Hayes, Alexander/0000-0001-6397-2630; Kinch, Kjartan/0000-0002-4629-8880; NR 19 TC 97 Z9 98 U1 3 U2 12 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 824 EP 826 DI 10.1126/science.3050824 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900036 PM 15297663 ER PT J AU Bertelsen, P Goetz, W Madsen, MB Kinch, KM Hviid, SF Knudsen, JM Gunnlaugsson, HP Merrison, J Nornberg, P Squyres, SW Bell, JF Herkenhoff, KE Gorevan, S Yen, AS Myrick, T Klingelhofer, G Rieder, R Gellert, R AF Bertelsen, P Goetz, W Madsen, MB Kinch, KM Hviid, SF Knudsen, JM Gunnlaugsson, HP Merrison, J Nornberg, P Squyres, SW Bell, JF Herkenhoff, KE Gorevan, S Yen, AS Myrick, T Klingelhofer, G Rieder, R Gellert, R TI Magnetic Properties Experiments on the Mars exploration Rover Spirit at Gusev crater SO SCIENCE LA English DT Article ID IRON-OXIDES; MOSSBAUER; SPECTROMETER; PATHFINDER; MISSION; IMAGER; ROCKS; SOILS AB The magnetic properties experiments are designed to help identify the magnetic minerals in the dust and rocks on Mars-and to determine whether liquid water was involved in the formation and alteration of these magnetic minerals. Almost all of the dust particles suspended in the martian atmosphere must contain ferrimagnetic minerals (such as maghemite or magnetite) in an amount of similar to2% by weight. The most magnetic fraction of the dust appears darker than the average dust. Magnetite was detected in the first two rocks ground by Spirit. C1 Univ Copenhagen, Danish Space Res Inst, Ctr Planetary Sci, DK-2100 Copenhagen, Denmark. Univ Copenhagen, Niels Bohr Inst Astron Phys & Geophys, DK-2100 Copenhagen, Denmark. Univ Aarhus, Dept Phys & Astron, DK-8000 Aarhus, Denmark. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. Univ Aarhus, Dept Earth Sci, DK-8000 Aarhus, Denmark. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. US Geol Survey, Branch Astrogeol, Flagstaff, AZ 86001 USA. Honeybee Robot Ltd, New York, NY 10012 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Johannes Gutenberg Univ Mainz, Inst Inorgan & Analyt Chem, D-55099 Mainz, Germany. Max Planck Inst Chem, D-55020 Mainz, Germany. RP Univ Copenhagen, Danish Space Res Inst, Ctr Planetary Sci, DK-2100 Copenhagen, Denmark. EM preben@fys.ku.dk RI Nornberg, Per/A-6228-2012; Madsen, Morten/D-2082-2011; Kinch, Kjartan/C-5742-2015; OI Madsen, Morten/0000-0001-8909-5111; Kinch, Kjartan/0000-0002-4629-8880; merrison, jonathan/0000-0003-4362-6356 NR 13 TC 57 Z9 57 U1 3 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 827 EP 829 DI 10.1126/science.1100112 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900037 PM 15297664 ER PT J AU Gellert, R Rieder, R Anderson, RC Bruckner, J Clark, BC Dreibus, G Economou, T Klingelhofer, G Lugmair, GW Ming, DW Squyres, SW d'Uston, C Wanke, H Yen, A Zipfel, J AF Gellert, R Rieder, R Anderson, RC Bruckner, J Clark, BC Dreibus, G Economou, T Klingelhofer, G Lugmair, GW Ming, DW Squyres, SW d'Uston, C Wanke, H Yen, A Zipfel, J TI Chemistry of rocks and soils in Gusev crater from the alpha particle x-ray spectrometer SO SCIENCE LA English DT Article ID CHEMICAL-COMPOSITION; PATHFINDER SITE; MARS; ROVER AB The alpha particle x-ray spectrometer on the Spirit rover determined major and minor elements of soils and rocks in Gusev crater in order to unravel the crustal evolution of planet Mars. The composition of soils is similar to those at previous landing sites, as a result of global mixing and distribution by dust storms. Rocks ( fresh surfaces exposed by the rock abrasion tool) resemble volcanic rocks of primitive basaltic composition with low intrinsic potassium contents. High abundance of bromine ( up to 170 parts per million) in rocks may indicate the alteration of surfaces formed during a past period of aqueous activity in Gusev crater. C1 Max Planck Inst Chem, D-55128 Mainz, Germany. Johannes Gutenberg Univ Mainz, Inst Anorgan & Analyt Chem, D-55128 Mainz, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lockheed Martin Corp, Littleton, CO 80127 USA. Univ Chicago, Enrico Fermi Inst, Lab Atmospher & Space Res, Chicago, IL 60637 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. RP Max Planck Inst Chem, JJ Becher Weg 27, D-55128 Mainz, Germany. EM gellert@mpch-mainz.mpg.de NR 17 TC 205 Z9 207 U1 2 U2 26 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 829 EP 832 DI 10.1126/science.1099913 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900038 PM 15297665 ER PT J AU Morris, RV Klingelhofer, G Bernhardt, B Schroder, C Rodionov, DS de Souza, PA Yen, A Gellert, R Evlanov, EN Foh, J Kankeleit, E Gutlich, P Ming, DW Renz, F Wdowiak, T Squyres, SW Arvidson, RE AF Morris, RV Klingelhofer, G Bernhardt, B Schroder, C Rodionov, DS de Souza, PA Yen, A Gellert, R Evlanov, EN Foh, J Kankeleit, E Gutlich, P Ming, DW Renz, F Wdowiak, T Squyres, SW Arvidson, RE TI Mineralogy at Gusev crater from the Mossbauer spectrometer on the Spirit rover SO SCIENCE LA English DT Article ID SNC METEORITES; MARS; SPECTROSCOPY; HEMATITE; ROCKS AB Mossbauer spectra measured on Mars by the Spirit rover during the primary mission are characterized by two ferrous iron doublets ( olivine and probably pyroxene) and a ferric iron doublet ( tentatively associated to nanophase ferric iron oxide). Two sextets resulting from nonstoichiometric magnetite are also present, except for a coating on the rock Mazatzal, where a hematite-like sextet is present. Greater proportions of ferric-bearing phases are associated with undisturbed soils and rock surfaces as compared to fresh rock surfaces exposed by grinding. The ubiquitous presence of olivine in soil suggests that physical rather than chemical weathering processes currently dominate at Gusev crater. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Mainz, Inst Anorgan & Analyt Chem, D-55128 Mainz, Germany. IKI, Space Res Inst, Moscow, Russia. CVRD Grp, Vitoria, Brazil. CALTECH, Jet Prop Lab, Pasadena, CA USA. Max Planck Inst Chem, D-55128 Mainz, Germany. TH Darmstadt, Darmstadt, Germany. Univ Alabama, Birmingham, AL USA. Cornell Univ, Ithaca, NY USA. Washington Univ, St Louis, MO USA. RP Morris, RV (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM richard.v.morris@nasa.gov RI de Souza, Paulo/B-8961-2008; Schroder, Christian/B-3870-2009 OI de Souza, Paulo/0000-0002-0091-8925; Schroder, Christian/0000-0002-7935-6039 NR 30 TC 165 Z9 168 U1 3 U2 25 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 833 EP 836 DI 10.1126/science.1100020 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900039 PM 15297666 ER PT J AU Christensen, PR Ruff, SW Fergason, RL Knudson, AT Anwar, S Arvidson, RE Bandfield, JL Blaney, DL Budney, C Calvin, WM Glotch, TD Golombek, MP Gorelick, N Graff, TG Hamilton, VE Hayes, A Johnson, JR McSween, HY Mehall, GL Mehall, LK Moersch, JE Morris, RV Rogers, AD Smith, MD Squyres, SW Wolff, MJ Wyatt, MB AF Christensen, PR Ruff, SW Fergason, RL Knudson, AT Anwar, S Arvidson, RE Bandfield, JL Blaney, DL Budney, C Calvin, WM Glotch, TD Golombek, MP Gorelick, N Graff, TG Hamilton, VE Hayes, A Johnson, JR McSween, HY Mehall, GL Mehall, LK Moersch, JE Morris, RV Rogers, AD Smith, MD Squyres, SW Wolff, MJ Wyatt, MB TI Initial results from the Mini-TES experiment in Gusev crater from the Spirit rover SO SCIENCE LA English DT Article ID THERMAL EMISSION-SPECTROSCOPY; MARS; SPECTROMETER; ROCKS; TERRESTRIAL; MINERALS; SPECTRA; DUST AB The Miniature Thermal Emission Spectrometer (Mini-TES) on Spirit has studied the mineralogy and thermophysical properties at Gusev crater. Undisturbed soil spectra show evidence for minor carbonates and bound water. Rocks are olivine-rich basalts with varying degrees of dust and other coatings. Dark-toned soils observed on disturbed surfaces may be derived from rocks and have derived mineralogy (+/- 5 to 10%) of 45% pyroxene (20% Ca-rich pyroxene and 25% pigeonite), 40% sodic to intermediate plagioclase, and 15% olivine (forsterite 45% +/- 5 to 10). Two spectrally distinct coatings are observed on rocks, a possible indicator of the interaction of water, rock, and airfall dust. Diurnal temperature data indicate particle sizes from 40 to 80 mum in hollows to similar to0.5 to 3 mm in soils. C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Nevada, Dept Geol Sci, Reno, NV 89557 USA. Univ Hawaii, Inst Geophys & Planetol, Honolulu, HI 96822 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Space Sci Inst, Martinez, GA 30907 USA. RP Christensen, PR (reprint author), Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. EM phil.christensen@asu.edu RI Glotch, Timothy/B-6829-2008; Moersch, Jeffrey/F-7189-2010; Smith, Michael/C-8875-2012; Hayes, Alexander/P-2024-2014; Johnson, Jeffrey/F-3972-2015; Rogers, Deanne/I-9737-2016 OI Hayes, Alexander/0000-0001-6397-2630; Rogers, Deanne/0000-0002-4671-2551 NR 26 TC 113 Z9 115 U1 1 U2 4 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 837 EP 842 DI 10.1126/science.1100564 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900040 PM 15297667 ER PT J AU McSween, HY Arvidson, RE Bell, JF Blaney, D Cabrol, NA Christensen, PR Clark, BC Crisp, JA Crumpler, LS Des Marais, DJ Farmer, JD Gellert, R Ghosh, A Gorevan, S Graff, T Grant, J Haskin, LA Herkenhoff, KE Johnson, JR Jolliff, BL Klingelhoefer, G Knudson, AT McLEnnan, S Milam, KA Moersch, JE Morris, RV Rieder, R Ruff, SW de Souza, PA Squyres, SW Wanke, H Wang, A Wyatt, MB Yen, A Zipfel, J AF McSween, HY Arvidson, RE Bell, JF Blaney, D Cabrol, NA Christensen, PR Clark, BC Crisp, JA Crumpler, LS Des Marais, DJ Farmer, JD Gellert, R Ghosh, A Gorevan, S Graff, T Grant, J Haskin, LA Herkenhoff, KE Johnson, JR Jolliff, BL Klingelhoefer, G Knudson, AT McLEnnan, S Milam, KA Moersch, JE Morris, RV Rieder, R Ruff, SW de Souza, PA Squyres, SW Wanke, H Wang, A Wyatt, MB Yen, A Zipfel, J TI Basaltic rocks analyzed by the Spirit rover in Gusev Crater SO SCIENCE LA English DT Article ID CHEMICAL CLASSIFICATION; PATHFINDER SITE; VOLCANIC-ROCKS; SOILS; MARS AB The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain less than or equal to25% megacrysts. Chemical analyses of rocks by the Alpha Particle X-ray Spectrometer are consistent with picritic basalts, containing normative olivine, pyroxenes, plagioclase, and accessory FeTi oxides. Mossbauer, Pancam, and Mini-TES spectra confirm the presence of olivine, magnetite, and probably pyroxene. These basalts extend the known range of rock compositions composing the martian crust. C1 Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Lockheed Martin Corp, Littleton, CO 80127 USA. New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA. Max Planck Inst Chem, D-55099 Mainz, Germany. Honeybee Robot, New York, NY 10012 USA. Smithsonian Inst, Natl Air & Space Museum, Washington, DC 20560 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Univ Mainz, Inst Anorgan & Analyt Chem, D-6500 Mainz, Germany. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Co Vale Rio Doce, BR-29090900 Vitoria, ES, Brazil. RP McSween, HY (reprint author), Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. EM mcsween@utk.edu RI de Souza, Paulo/B-8961-2008; Moersch, Jeffrey/F-7189-2010; Johnson, Jeffrey/F-3972-2015; Crisp, Joy/H-8287-2016 OI de Souza, Paulo/0000-0002-0091-8925; Crisp, Joy/0000-0002-3202-4416 NR 16 TC 187 Z9 187 U1 2 U2 27 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 6 PY 2004 VL 305 IS 5685 BP 842 EP 845 DI 10.1126/science.1099851 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 843RT UT WOS:000223104900041 PM 15297668 ER PT J AU Djikaev, YS Tabazadeh, A AF Djikaev, YS Tabazadeh, A TI Effect of adsorption on crystal nucleation in binary droplets: Implication for the formation of nitric acid hydrate particles SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AIR-WATER-INTERFACE; SULFURIC-ACID; SURFACTANT SOLUTIONS; ICE NUCLEATION; WAVE-CLOUDS; THERMODYNAMICS; CRYSTALLIZATION; CONDENSATION; DEPENDENCE; AEROSOLS AB The adsorption of surfactant molecules at the droplet-vapor interface can affect the droplet surface tension and thus alter the rate of surface-stimulated crystal nucleation. Recently, we have shown that if the condition of partial wetting holds for at least one crystal facet then the crystallization process is most likely to initiate at the droplet surface. Here, we outline an adsorption model to determine the main physical characteristics of the interior and surface layer of a binary droplet. The theoretical model is illustrated by numerical calculations for aqueous nitric acid droplets. As expected, an increase in the surfactant concentration in the droplet interior lowers the droplet surface tension, which has an impeding effect on the surface-stimulated crystallization. However, we show that an increase in the surface-to-volume ratio of a droplet favors crystal nucleation at the surface not only kinetically but also thermodynamically. This occurs because for a given droplet composition smaller droplets have a higher surface tension. Thus, the impeding effect of a soluble surfactant on the surface mode of crystal nucleation becomes weaker as the droplet size decreases. Our results also show that for a fixed overall droplet composition the excess surface coverage decreases with decreasing droplet radius. The effect of organic contaminants on crystallization in aqueous nitric acid droplets is also qualitatively studied. C1 NASA, Ames Res Ctr, NRC Res Associateship, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. RP Djikaev, YS (reprint author), Cornell Univ, Dept Chem & Chem Biol, Ithaca, NY 14853 USA. EM id45@corell.edu NR 29 TC 7 Z9 7 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD AUG 5 PY 2004 VL 108 IS 31 BP 6513 EP 6519 DI 10.1021/jp031218l PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 842KG UT WOS:000223002300009 ER PT J AU Wang, Z Whiteman, DN Demoz, BB Veselovskii, I AF Wang, Z Whiteman, DN Demoz, BB Veselovskii, I TI A new way to measure cirrus cloud ice water content by using ice Raman scatter with Raman lidar SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIATIVE PROPERTIES; CLIMATE; PARTICLES AB To improve our understanding of cirrus cloud radiative impact on the current and future climate, improved knowledge of cirrus cloud microphysical properties is needed. However, long-term studies of the problem indicate that accurate cirrus cloud measurements are challenging. This is true for both, remote sensing as well as in situ sampling. This study presents a new method to remotely sense cirrus microphysical properties utilizing the Raman scattered intensities from ice crystals using a Raman lidar. Since the intensity of Raman scattering is fundamentally proportional to the number of molecules involved, this method provides a more direct way of measuring the ice water content compared with other schemes. Case studies presented here show that this method has the potential to provide simultaneous measurements of many of the essential information of cirrus microphysical properties. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Mesoscale Atmospher Proc Branch, Greenbelt, MD 20771 USA. RP Wang, Z (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, NASA, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. EM zhien@agnes.gsfc.nasa.gov RI Wang, Zhien/F-4857-2011; Demoz, Belay/N-4130-2014 NR 12 TC 6 Z9 6 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 AUG 4 PY 2004 VL 31 IS 15 AR L15101 DI 10.1029/2004GL020004 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 846RZ UT WOS:000223335200002 ER PT J AU Buss, S Hertzog, A Hostettler, C Bui, TP Luthi, D Wernli, H AF Buss, S Hertzog, A Hostettler, C Bui, TP Luthi, D Wernli, H TI Analysis of a jet stream induced gravity wave associated with an observed stratospheric ice cloud over Greenland SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID UPPER BOUNDARY-CONDITION; CLEAR-AIR TURBULENCE; TROPOSPHERIC JET; MIDDLE ATMOSPHERE; OZONE DEPLETION; MOUNTAIN WAVES; GENERATION; MODELS; INSTABILITY; SCANDINAVIA AB A polar stratospheric ice cloud (PSC type II) was observed by airborne lidar above Greenland on 14 January 2000. It was the unique observation of an ice cloud over Greenland during the SOLVE/THESEO 2000 campaign. Mesoscale simulations with the hydrostatic HRM model are presented which, in contrast to global analyses, are capable to produce a vertically propagating gravity wave that induces the low temperatures at the level of the PSC afforded for the ice formation. The simulated minimum temperature is similar to8 K below the driving analyses and similar to4.5 K below the frost point, exactly coinciding with the location of the observed ice cloud. Despite the high elevations of the Greenland orography the simulated gravity wave is not a mountain wave. Analyses of the horizontal wind divergence, of the background wind profiles, of backward gravity wave ray-tracing trajectories, of HRM experiments with reduced Greenland topography and of several diagnostics near the tropopause level provide evidence that the wave is emitted from an intense, rapidly evolving, anticyclonically curved jet stream. The precise physical process responsible for the wave emission could not be identified definitely, but geostrophic adjustment and shear instability are likely candidates. In order to evaluate the potential frequency of such non-orographic polar stratospheric cloud events, the non-linear balance equation diagnostic is performed for the winter 1999/2000. It indicates that ice-PSCs are only occasionally generated by gravity waves emanating from spontaneous adjustment. C1 ETH, Inst Atmospher & Climat Sci, Zurich, Switzerland. Swiss Fed Off Meorol & Climatol MeteoSwiss, Zurich, Switzerland. Meteorol Dynam Lab, Palaiseau, France. NASA, Langley Res Ctr, Hampton, VA 23665 USA. NASA, Ames Res Ctr, Moffiett Field, CA USA. Univ Mainz, Inst Phys Atmosphare, D-6500 Mainz, Germany. RP Buss, S (reprint author), ETH, Inst Atmospher & Climat Sci, Zurich, Switzerland. EM sbuss@largeur.com RI Hertzog, Albert/A-2899-2012 NR 47 TC 13 Z9 14 U1 0 U2 1 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD AUG 3 PY 2004 VL 4 BP 1183 EP 1200 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 843GK UT WOS:000223066300003 ER PT J AU Considine, DB Connell, PS Bergmann, DJ Rotman, DA Strahan, SE AF Considine, DB Connell, PS Bergmann, DJ Rotman, DA Strahan, SE TI Sensitivity of Global Modeling Initiative model predictions of Antarctic ozone recovery to input meteorological fields SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone; recovery; stratosphere ID DATA ASSIMILATION; NITROUS-OXIDE; STRATOSPHERIC WINDS; INORGANIC CHLORINE; TRANSPORT; VALIDATION; AGE; INSTRUMENT; SPECTRA; SMVGEAR AB We use the Global Modeling Initiative chemistry and transport model to simulate the evolution of stratospheric ozone between 1995 and 2030, using boundary conditions consistent with the recent World Meteorological Organization ozone assessment. We compare the Antarctic ozone recovery predictions of two simulations, one driven by an annually repeated year of meteorological data from a general circulation model (GCM), the other using a year of output from a data assimilation system (DAS), to examine the sensitivity of Antarctic ozone recovery predictions to the characteristic dynamical differences between GCM- and DAS-generated meteorological data. Although the age of air in the Antarctic lower stratosphere differs by a factor of 2 between the simulations, we find little sensitivity of the 1995-2030 Antarctic ozone recovery between 350 and 650 K to the differing meteorological fields, particularly when the recovery is specified in mixing ratio units. Percent changes are smaller in the DAS-driven simulation compared to the GCM-driven simulation because of a surplus of Antarctic ozone in the DAS-driven simulation which is not consistent with observations. The peak ozone change between 1995 and 2030 in both simulations is similar to20% lower than photochemical expectations, indicating that changes in ozone transport due to changing ozone gradients at 450 K between 1995 and 2030 constitute a small negative feedback. Total winter/spring ozone loss during the base year (1995) of both simulations and the rate of ozone loss during August and September is somewhat weaker than observed. This appears to be due to underestimates of Antarctic C1(y) at the 450-K potential temperature level. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA 94550 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. RP Considine, DB (reprint author), NASA, Langley Res Ctr, Mail Stop 401B, Hampton, VA 23681 USA. EM david.b.considine@nasa.gov; connell2@llnl.gov; bergmann1@llnl.gov; rotman1@llnl.gov; strahan@code916.gsfc.nasa.gov RI Bergmann, Daniel/F-9801-2011; Strahan, Susan/H-1965-2012 OI Bergmann, Daniel/0000-0003-4357-6301; NR 34 TC 7 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 3 PY 2004 VL 109 IS D15 AR D15301 DI 10.1029/2003JD004487 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 846SG UT WOS:000223335900001 ER PT J AU Matney, MJ AF Matney, MJ TI Toward a comprehensive GEO debris measurement strategy SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 54th Congress of the Interantional-Astronautical-Federation (IAF) CY SEP 29-OCT 03, 2003 CL Bremen, GERMANY SP Int Astronaut Federat AB In recent years there has been increasing interest in the effects of orbital debris on the Geosynchronous Earth Orbit (GEO) environment. This region has great economic importance that is only expected to grow stronger in the foreseeable future. The lifetime of any debris created is very long, so that there is no effective sink to remove the debris in a timely manner. Considerable resources have been brought to bear to understand the current debris environment at GEO. A number of optical telescopes in different countries are now systematically making observations of this region specifically to understand the debris population. We are now at a stage where we can begin to answer specific questions about orbital debris in these orbits, but what are these questions? Are we asking the right questions? Are the observations we are pursuing answering the most important questions? Are there changes needed in the observation techniques to better address the most important issues? Are there changes needed in the types of instruments to answer the most important questions? This paper will outline the broad questions that GEO observations should be designed to answer. I will discuss how observations so far have begun to answer those questions and where they need to concentrate in the future. This will include discussions of the benefits and limitations of the statistical sampling methodology versus the cataloguing methodology. I hope to provide a framework for future observations that will be of benefit to all GEO users. Published by Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Matney, MJ (reprint author), Lockheed Martin Space Mission, Mail Code C104,2400 NASA Rd 1, Houston, TX 77058 USA. EM mark.matney-1@nasa.gov NR 11 TC 0 Z9 0 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 AUG-NOV PY 2004 VL 55 IS 3-9 BP 291 EP 298 DI 10.1016/j.actasstro.2004.05.054 PG 8 WC Engineering, Aerospace SC Engineering GA 849XG UT WOS:000223574300016 ER PT J AU Jules, K McPherson, K Hrovat, K Kelly, E Reckart, T AF Jules, K McPherson, K Hrovat, K Kelly, E Reckart, T TI A status report on the characterization of the microgravity environment of the International Space Station SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 54th Congress of the Interantional-Astronautical-Federation (IAF) CY SEP 29-OCT 03, 2003 CL Bremen, GERMANY SP Int Astronaut Federat AB A primary objective of the International Space Station is to provide a long-term quiescent environment for the conduct of scientific research for a variety of microgravity science disciplines. Since continuous human presence on the space station began in November 2000 through the end of Increment-6, over 1260 hours of crew time have been allocated to research. However, far more research time has been accumulated by experiments controlled on the ground. By the end of the time period covered by this paper (end of Increment-6), the total experiment hours performed on the station are well over 100 000 hours (Expedition 6 Press Kit: Station Begins Third Year of Human Occupation, Boeing/USAfNASA, October 25, 2002). This paper presents the results of the on-going effort by the Principal Investigator Microgravity Services project, at NASA Glenn Research Center, in Cleveland, Ohio, to characterize the microgravity environment of the International Space Station in order to keep the microgravity scientific community apprised of the reduced gravity environment provided by the station for the performance of space experiments. This paper focuses on the station microgravity environment for Increments 5 and 6. During that period over 580 Gbytes of acceleration data were collected, out of which over 34 790 hours were analyzed. The results presented in this paper are divided into two sections: quasi-steady and vibratory. For the quasi-steady analysis, over 7794 hours of acceleration data were analyzed, while over 27 000 hours Were analyzed for the vibratory analysis. The results of the data analysis are presented in this paper in the form of a grand summary for the period under consideration. For the quasi-steady acceleration response, results are presented in the form of a 95% confidence interval for the station during "normal microgravity mode operations" for the following three attitudes: local vertical local horizontal, X-axis perpendicular to the orbit plane and the Russian torque equilibrium attitude. The same analysis was performed for the station during "non-microgravity mode operations" to assess the station quasi-steady acceleration environment over a long period of time. The same type of analysis was performed for the vibratory, but a 95th percentile benchmark was used, which shows the overall acceleration magnitude during Increments 5 and 6. The results, for both quasi-steady and vibratory acceleration response, show that the station is not yet meeting the microgravity requirements during the microgravity mode operations. However, it should be stressed that the requirements apply only at assembly complete, whereas the results presented below apply up to the station's configuration at the end of Increment-6. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. ZIN Technol Inc, Cleveland, OH 44135 USA. RP Jules, K (reprint author), NASA, Glenn Res Ctr, Mail Stop 77-7,21000 Brookpark Rd, Cleveland, OH 44135 USA. NR 21 TC 11 Z9 11 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 AUG-NOV PY 2004 VL 55 IS 3-9 BP 335 EP 364 DI 10.1016/j.actaastro.2004.05.057 PG 30 WC Engineering, Aerospace SC Engineering GA 849XG UT WOS:000223574300020 PM 15806740 ER PT J AU Woodcock, G Suter, J Morgenthaler, G AF Woodcock, G Suter, J Morgenthaler, G TI Reusable launch architecture to support sustainable human exploration of the Solar system SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 54th Congress of the Interantional-Astronautical-Federation (IAF) CY SEP 29-OCT 03, 2003 CL Bremen, GERMANY SP Int Astronaut Federat AB A launch-assisted, horizontal takeoff, reusable Earth-to-orbit (ETO) vehicle is introduced, described, and its concept of operations, a typical trajectory, its performance, mass and cost estimates are presented. This concept enables near aircraft-like operations for a launch system, enhances safety, and reduces cost compared to vertical takeoff systems. Benefits are described. With over a 20 t payload and a payload bay 5 m x 15 m, it is compatible with the human exploration architectures presented in a companion paper, IAA.10.3.02. [1] (C) 2004 Elsevier Ltd. All rights reserved. C1 Gray Res, Huntsville, AL 35806 USA. NASA, George C Marshall Space Flight Ctr, Tech Management Explorat & Dev Off, Huntsville, AL 35812 USA. Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA. RP Woodcock, G (reprint author), Gray Res, 655 Discovery Dr,Suite 300, Huntsville, AL 35806 USA. NR 8 TC 0 Z9 0 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 AUG-NOV PY 2004 VL 55 IS 3-9 BP 365 EP 374 DI 10.1016/j.actasstro.2004.05.048 PG 10 WC Engineering, Aerospace SC Engineering GA 849XG UT WOS:000223574300021 ER PT J AU Pellis, NR North, RM AF Pellis, NR North, RM TI Recent NASA research accomplishments aboard the ISS SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 54th Congress of the Interantional-Astronautical-Federation (IAF) CY SEP 29-OCT 03, 2003 CL Bremen, GERMANY SP Int Astronaut Federat ID INTERNATIONAL-SPACE-STATION; POLYPEPTIDE (PPG)(10) ABOARD; X-RAY-DIFFRACTION; SPATIAL-RESOLUTION; APPLIED PHYSIOLOGY; GENETIC MODELS; C57BL/6 MOUSE; CRYSTALLIZATION; SPACEFLIGHT; IMMUNITY AB The activation of the US Laboratory Module "Destiny" on the International Space Station (ISS) in February 2001 launched a new era in microgravity research. Destiny provides the environment to conduct long-term microgravity research utilizing human intervention to assess, report, and modify experiments real time. As the only available pressurized space platform, ISS maximizes today's scientific resources and substantially increases the opportunity to obtain much longed-for answers on the effects of microgravity and long-term exposure to space. In addition, it evokes unexpected questions and results while experiments are still being conducted, affording time for changes and further investigation. While building and outfitting the ISS is the main priority during the current ISS assembly phase, seven different space station crews have already spent more than 2000 crew hours on approximately 80 scientific investigations, technology development activities, and educational demonstrations. Published by Elsevier Ltd. C1 NASA, ISS, OBPR, Washington, DC 20546 USA. NASA, Lyndon B Johnson Space Ctr, ISS, Off ISS Res Program Sci, Houston, TX 77058 USA. RP Pellis, NR (reprint author), NASA, ISS, OBPR, Washington, DC 20546 USA. EM neal.r.pellis-1@nasa.gov; regina.northI@jsc.nasa.gov NR 31 TC 1 Z9 3 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 AUG-NOV PY 2004 VL 55 IS 3-9 BP 589 EP 598 DI 10.1016/j.actaastro.2004.05.026 PG 10 WC Engineering, Aerospace SC Engineering GA 849XG UT WOS:000223574300042 PM 15806746 ER PT J AU Moses, PL Rausch, VL Nguyen, LT Hill, JR AF Moses, PL Rausch, VL Nguyen, LT Hill, JR TI NASA hypersonic flight demonstrators - overview, status, and future plans SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 54th Congress of the Interantional-Astronautical-Federation (IAF) CY SEP 29-OCT 03, 2003 CL Bremen, GERMANY SP Int Astronaut Federat AB NASA's Next Generation Launch Technology (NGLT) program is developing and maturing advanced propulsion and vehicle systems technologies and flight vehicle concepts to enable future development of safer and more economical launch systems. Within NGLT, NASA is developing advanced air breathing propulsion systems and demonstrating these systems in hypersonic flight vehicles. The flight demonstrations are necessary to fully validate these technologies for application to future space launch vehicles and other flight systems. NASA's Hyper-X Program (X-43A) began the effort to flight demonstrate hypersonic air breathing propulsion systems to provide technologies that will enable development of safer and more economic space access vehicles in the future. Following X-43A, NASA, in collaboration with the United States (US) Department of Defense (DoD), is developing additional, progressively more complex hypersonic X-vehicles that will demonstrate new air breathing propulsion systems, propulsion-airframe integration, and other vehicle systems technologies required for high speed flight up to Mach 15. These technologies will contribute to safer, more reliable and more economic future launch systems and hypersonic aircraft/missiles. This paper describes NASA's current hypersonic flight demonstration projects, status of the efforts, and plans for future vehicles. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Moses, PL (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 3 TC 42 Z9 55 U1 10 U2 39 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 AUG-NOV PY 2004 VL 55 IS 3-9 BP 619 EP 630 DI 10.1016/j.actaastro.2004.05.045 PG 12 WC Engineering, Aerospace SC Engineering GA 849XG UT WOS:000223574300045 ER PT J AU Mendell, WW Heydorn, RP AF Mendell, WW Heydorn, RP TI Lunar precursor missions for human exploration of Mars - III: studies of system reliability and maintenance SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 54th Congress of the Interantional-Astronautical-Federation (IAF) CY SEP 29-OCT 03, 2003 CL Bremen, GERMANY SP Int Astronaut Federat AB Discussions of future human expeditions into the solar system generally focus on whether the next explorers ought to go to the Moon or to Mars. The only mission scenario developed in any detail within NASA is an expedition to Mars with a 500-day stay at the surface. The technological capabilities and the operational experience base required for such a mission do not now exist nor has any self-consistent program plan been proposed to acquire them. In particular, the lack of an Abort-to-Earth capability implies that critical mission systems must perform reliably for 3 years or must be maintainable and repairable by the crew. As has been previously argued, a well-planned program of human exploration of the Moon would provide a context within which to develop the appropriate technologies because a lunar expedition incorporates many of the operational elements of a Mars expedition. Initial lunar expeditions can be carried out at scales consistent with the current experience base but can be expanded in any or all operational phases to produce an experience base necessary to successfully and safely conduct human exploration of Mars. Published by Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Mendell, WW (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Rd 1, Houston, TX 77058 USA. EM wendell.mendell@jsc.nasa.gov NR 5 TC 4 Z9 4 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD AUG-NOV PY 2004 VL 55 IS 3-9 BP 773 EP 780 DI 10.1016/j.actaastro.2004.05.020 PG 8 WC Engineering, Aerospace SC Engineering GA 849XG UT WOS:000223574300061 PM 15806749 ER PT J AU Johnson, NL AF Johnson, NL TI Space traffic management concepts and practices SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 54th Congress of the Interantional-Astronautical-Federation (IAF) CY SEP 29-OCT 03, 2003 CL Bremen, GERMANY SP Int Astronaut Federat AB Concepts of space traffic management have been discussed for many years with little progress to date, due both to the complexity of the issue and to a perceived lack of urgency. Although a renewed interest in the subject has arisen in some corners of the aerospace community, the challenges of space traffic management remain unchanged. Perhaps the greatest challenge is reaching a consensus on the definition of space traffic management and its objectives. In the simplest terms, space traffic management should promote physical and electromagnetic non-interference among the multitude of operational space systems. However, contrary to popular belief, air and ground traffic control concepts and techniques, offer few analogies applicable to the space environment. The value of a space traffic management system must weigh the historical and legally entrenched concept of the freedom of operation in near-Earth orbit against the potential benefits of a new regulatory regime. Most space-faring nations do not yet exert control over the selection of orbital parameters for new space systems within their own countries, much less in an international context. The prospects for such intrusive space traffic management in the foreseeable future are not bright. 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 10 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 AUG-NOV PY 2004 VL 55 IS 3-9 BP 803 EP 809 DI 10.1016/j.actaastro.2004.05.055 PG 7 WC Engineering, Aerospace SC Engineering GA 849XG UT WOS:000223574300064 ER PT J AU Walker, JP Houser, PR AF Walker, JP Houser, PR TI Requirements of a global near-surface soil moisture satellite mission: accuracy, repeat time, and spatial resolution SO ADVANCES IN WATER RESOURCES LA English DT Article DE soil moisture; remote sensing; mission requirements; data assimilation; modelling ID CATCHMENT-BASED APPROACH; DATA ASSIMILATION; PROFILE RETRIEVAL; FIELD APPLICATION; KALMAN FILTER; MODEL; PARAMETERIZATION; METHODOLOGY; WATER AB Soil moisture satellite mission accuracy, repeat time and spatial resolution requirements are addressed through a numerical twill data assimilation study. Simulated soil moisture profile retrievals were made by assimilating near-surface soil moisture observations with various accuracy (0, 1 2, 3 4, 5 and 10%v/v standard deviation) repeat time (1, 2, 3, 5, 10, 15, 20 and 30 days), and spatial resolution (0.5, 6, 12 18, 30, 60 and 120 arc-min). This study found that near-surface soil moisture observation error must be less than the model forecast error required for a specific application when used as data assimilation input, else slight model forecast degradation may result. It also found that near-surface soil moisture observations must have all accuracy better than 5%v/v to positively impact soil moisture forecasts, and that daily near-surface soil moisture observations achieved the best soil moisture and evapotranspiration forecasts for the repeat times assessed, with 1-5 day repeat times having the greatest impact. Near-surface soil moisture observations with a spatial resolution finer than the land surface model resolution (similar to30 arc-min) produced the best results, with spatial resolutions coarser than the model resolution yielding only a slight degradation. Observations at half the land surface model spatial resolution were found to be appropriate for our application. Moreover, it was found that satisfying the spatial resolution and accuracy requirements was much more important than repeat time. Published by Elsevier Ltd. C1 Univ Melbourne, Dept Civil & Environm Engn, Parkville, Vic 3010, Australia. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Walker, JP (reprint author), Univ Melbourne, Dept Civil & Environm Engn, Parkville, Vic 3010, Australia. EM j.walker@unimelb.edu.au RI Walker, Jeffrey/D-2624-2009; Houser, Paul/J-9515-2013 OI Houser, Paul/0000-0002-2991-0441 NR 35 TC 73 Z9 76 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 EI 1872-9657 J9 ADV WATER RESOUR JI Adv. Water Resour. PD AUG PY 2004 VL 27 IS 8 BP 785 EP 801 DI 10.1016/j.advwatres.2004.05.006 PG 17 WC Water Resources SC Water Resources GA 853BM UT WOS:000223801200002 ER PT J AU Mathelin, L Hussaini, MY Zang, TA Bataille, F AF Mathelin, L Hussaini, MY Zang, TA Bataille, F TI Uncertainty propagation for a turbulent, compressible nozzle flow using stochastic methods SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 16th Computational Fluid Dynamics Conference CY JUN 23-26, 2003 CL Orlando, FL SP Amer Inst Aeronaut & Astronaut ID COMPUTATIONAL FLUID-DYNAMICS; GENERALIZED POLYNOMIAL CHAOS; PROJECTION METHOD; VALIDATION; VERIFICATION AB A fully spectral, polynomial chaos method for the propagation of uncertainty in numerical simulations of compressible, turbulent How is described. The method is applied to the flow in a quasi-one-dimensional nozzle. Results demonstrate the ability of the method to propagate accurately the uncertainty throughout the entire numerical field. Comparison and validation were made with the reference Monte Carlo method. An exact method and an approximate method for the computation of inner products are also discussed in terms of efficiency and number of operations required. C1 Florida State Univ, Tallahassee, FL 32306 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Ctr Therm Lyon, F-69621 Villeurbanne, France. RP Mathelin, L (reprint author), CNRS, Sch Computat Sci & Informat Technol, Lab Informat Mecan & Sci, BP 133, F-91403 Orsay, France. NR 40 TC 21 Z9 23 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD AUG PY 2004 VL 42 IS 8 BP 1669 EP 1676 DI 10.2514/1.5674 PG 8 WC Engineering, Aerospace SC Engineering GA 844FC UT WOS:000223141900020 ER PT J AU Leiser, DB AF Leiser, DB TI Space shuttle thermal protection system SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article C1 NASA, Thermal Protect Mat & Syst Branch, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Leiser, DB (reprint author), NASA, Thermal Protect Mat & Syst Branch, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 5 Z9 5 U1 0 U2 10 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43086-6136 USA SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD AUG PY 2004 VL 83 IS 8 BP 44 EP 47 PG 4 WC Materials Science, Ceramics SC Materials Science GA 845ZY UT WOS:000223285600033 ER PT J AU Yang, P Kattawar, GW Wiscombe, WJ AF Yang, P Kattawar, GW Wiscombe, WJ TI Effect of particle asphericity on single-scattering parameters: comparison between Platonic solids and spheres SO APPLIED OPTICS LA English DT Article ID NONSPHERICAL CHEBYSHEV PARTICLES; DISCRETE-DIPOLE APPROXIMATION; ICE CRYSTAL SIZE; LIGHT-SCATTERING; T-MATRIX; RADIATIVE PROPERTIES; CIRRUS CLOUDS; EXTINCTION EFFICIENCY; ELECTROMAGNETIC-WAVES; CROSS-SECTIONS AB The single-scattering properties of the Platonic shapes, namely, the tetrahedron, hexahedron, octahedron, dodecahedron, and icosahedron, are investigated by use of the finite-difference time-domain method. These Platonic shapes have different extents of asphericity in terms of the ratios of their volumes (or surface areas) to those of their circumscribed spheres. We present the errors associated with four types of spherical equivalence that are defined on the basis of (a) the particle's geometric dimension (b) equal surface area (A), (c) equal volume (V), and (d) equal-volume-to-surface-area ratio (V/A). Numerical results show that the derivations of the scattering properties of a nonspherical particle from its spherical counterpart depend on the definition of spherical equivalence. For instance, when the Platonic and spherical particles have the same geometric dimension, the phase function for a dodecahedron is more similar than that for an icosahedron to the spherical result even though an icosahedron has more faces than a dodecahedron. However, when the nonspherical and spherical particles have the same volume, the phase function of the icosahedral particle essentially converges to the phase function of the sphere, whereas the result for the dodecahedron is quite different from its spherical counterpart. Furthermore, the present scattering calculation shows that the approximation of a Platonic solid with a sphere based on V/A leads to larger errors than the spherical equivalence based on either volume or projected area. (C) 2004 Optical Society of America. 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 Yang, P (reprint author), Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. EM pyang@ariel.met.tamu.edu RI Yang, Ping/B-4590-2011; Wiscombe, Warren/D-4665-2012 OI Wiscombe, Warren/0000-0001-6844-9849 NR 49 TC 10 Z9 10 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD AUG 1 PY 2004 VL 43 IS 22 BP 4427 EP 4435 DI 10.1364/AO.43.004427 PG 9 WC Optics SC Optics GA 841MP UT WOS:000222934800019 PM 15298417 ER PT J AU Webster, CR Flesch, GJ Mansour, K Haberle, R Bauman, J AF Webster, CR Flesch, GJ Mansour, K Haberle, R Bauman, J TI Mars laser hygrometer SO APPLIED OPTICS LA English DT Article ID WATER AB We have designed and built a miniature near-IR tunable diode laser (TDL) spectrometer for measuring in situ the water vapor mixing ratio either in the Martian atmosphere or thermally evolved from Martian soil or ice samples. The laser hygrometer uses a thermoelectrically cooled single-mode distributed-feedback TDL at 1.87 mum to scan over a selected vibration-rotation line of both H2O and CO2 near 5327.3 cm(-1). A working prototype that weighs only 230 g has been built and used to generate spectra whose analysis demonstrates precision sensitivities as fine as 1 part in 106 by volume in 1 s or 0.1 part in 10(6) in 10 s at Martian pressures and temperatures. Absolute uncertainties of similar to5% are calculated. (C) 2004 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94305 USA. RP Webster, CR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM chris.r.webster@jpl.nasa.gov NR 22 TC 20 Z9 20 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD AUG 1 PY 2004 VL 43 IS 22 BP 4436 EP 4445 DI 10.1364/AO.43.004436 PG 10 WC Optics SC Optics GA 841MP UT WOS:000222934800020 PM 15298418 ER PT J AU Ramirez, SV Rebull, L Stauffer, J Strom, S Hillenbrand, L Hearty, T Kopan, EL Pravdo, S Makidon, R Jones, B AF Ramirez, SV Rebull, L Stauffer, J Strom, S Hillenbrand, L Hearty, T Kopan, EL Pravdo, S Makidon, R Jones, B TI Chandra X-ray observations of young clusters. II. Orion flanking fields data SO ASTRONOMICAL JOURNAL LA English DT Article DE stars : activity; stars : pre-main-sequence; X-rays : stars ID MAIN-SEQUENCE STARS; T-TAURI STARS; SOLAR-TYPE STARS; LOW-MASS STARS; LATE B-TYPE; NEBULA CLUSTER; ROTATIONAL VELOCITIES; STELLAR POPULATION; TRAPEZIUM CLUSTER; MOLECULAR CLOUD AB We present results of Chandra observations of two flanking fields (FFs) in Orion, outside the Orion Nebula Cluster ( ONC). The observations were taken with the ACIS-I camera with an exposure time of about 48 ks each field. We present a catalog of 417 sources, which includes X-ray luminosity, optical and infrared photometry, and X-ray variability information. We have found 91 variable sources, 33 of which have a flarelike light curve and 11 of which have a pattern of a steady increase or decrease over a 10 hr period. The optical and infrared photometry for the stars identified as X-ray sources are consistent with most of these objects being pre-main-sequence stars with ages younger than 10 Myr. We present evidence for an age difference among the X-ray-selected samples of NGC 2264, Orion FFs, and ONC, with NGC 2264 being the oldest and ONC being the youngest. C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Kitt Peak Natl Observ, Natl Opt Astron Observ, Tucson, AZ 85726 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, IPAC, Pasadena, CA 91125 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Calif Santa Cruz, Dept Astron, Santa Cruz, CA 95064 USA. RP Ramirez, SV (reprint author), CALTECH, Spitzer Sci Ctr, Mail Stop 220-06,1200 E Calif Blvd, Pasadena, CA 91125 USA. OI Rebull, Luisa/0000-0001-6381-515X NR 71 TC 20 Z9 20 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 AUG PY 2004 VL 128 IS 2 BP 787 EP 804 DI 10.1086/422349 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 843QO UT WOS:000223099600021 ER PT J AU Pottasch, SR Bernard-Salas, J Beintema, DA Feibelman, WA AF Pottasch, SR Bernard-Salas, J Beintema, DA Feibelman, WA TI Abundances of Planetary Nebulae IC 418, IC 2165 and NGC 5882 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : abundances; ISM : planetary nebulae : individual : NGC 5882 : IC 418 : IC 2165; infrared : ISM ID NRAO PMN SURVEYS; ULTRAVIOLET-SPECTRA; EMISSION-LINES; 4.85 GHZ; CHEMICAL ABUNDANCES; SOURCE CATALOG; CENTRAL STARS; O-VI; IUE; FLUXES AB The ISO and IUE spectra of the elliptical nebulae NGC 5882, IC 418 and IC 2165 are presented. These spectra are combined with the spectra in the visual wavelength region to obtain a complete, extinction corrected, spectrum. The chemical composition of the nebulae is then calculated and compared to previous determinations. A discussion is given of: (1) the recombination line abundances; (2) the exciting stars of the nebulae; and (3) possible evolutionary effects. C1 Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. SRON Lab Space Res, NL-9700 AV Groningen, Netherlands. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14850 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Pottasch, SR (reprint author), Kapteyn Astron Inst, POB 800, NL-9700 AV Groningen, Netherlands. EM pottasch@astro.rug.nl NR 56 TC 28 Z9 28 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2004 VL 423 IS 2 BP 593 EP 605 DI 10.1051/0004-6361:20040413 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850OD UT WOS:000223621400026 ER PT J AU Masetti, N Foschini, L Palazzi, E Beckmann, V Lund, N Brandt, S Westergaard, NJ Amati, L Caroli, E Del Sordo, S Di Cocco, G Durouchoux, P Farinelli, R Frontera, F Orlandini, M Zdziarski, A AF Masetti, N Foschini, L Palazzi, E Beckmann, V Lund, N Brandt, S Westergaard, NJ Amati, L Caroli, E Del Sordo, S Di Cocco, G Durouchoux, P Farinelli, R Frontera, F Orlandini, M Zdziarski, A TI Serpens X-1 observed by INTEGRAL SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE X-rays : binaries; X-rays : individuals : Ser X-1; stars : neutron ID X-RAY BINARIES; OPTICAL COUNTERPART; SER X-1; JEM-X; BURST; CATALOG; SPECTROMETER; SOFTWARE; BEHAVIOR; BEPPOSAX AB Here we report results of an INTEGRAL-AO1 observation of the X-ray burst and atoll source Ser X-1 performed in May 2003. The object was observed for a total on-source time of 400 ks but nearly 8degrees off-axis due to its amalgamation with an observation of SS 433, the pointing target source. Ser X-1 has been clearly detected up to 30 keV with unprecedented positional accuracy for high-energy emission. The 20-30 keV light curve showed substantial variability during the observation. Comparison with previous observations indicates that the source was in its high ("banana") state and displayed a soft spectrum during the INTEGRAL pointing. A (non simultaneous) radio-to-gamma-rays broad-band spectral energy distribution is also presented for the first time and discussed. C1 CNR, Sez Bologna, Ist Astrofis Spaziale & Fis Cosm, I-40129 Bologna, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Danish Space Res Inst, DK-2100 Copenhagen O, Denmark. CNR, Sez Palermo, Ist Astrofis Spaziale & Fis Cosm, I-90146 Palermo, Italy. CEA Saclay, DSM, DAPNIA, Serv Astrophys, F-91191 Gif Sur Yvette, France. Univ Ferrara, Dept Phys, I-44100 Ferrara, Italy. Nicholas Copernicus Astron Ctr, PL-00716 Warsaw, Poland. RP Masetti, N (reprint author), CNR, Sez Bologna, Ist Astrofis Spaziale & Fis Cosm, Via Gobetti 101, I-40129 Bologna, Italy. EM masetti@bo.iasf.cnr.it RI Foschini, Luigi/H-3833-2012; Orlandini, Mauro/H-3114-2014; Caroli, Ezio/G-1427-2012; Palazzi, Eliana/N-4746-2015; Amati, Lorenzo/N-5586-2015; OI Foschini, Luigi/0000-0001-8678-0324; Orlandini, Mauro/0000-0003-0946-3151; Caroli, Ezio/0000-0001-8468-7433; Amati, Lorenzo/0000-0001-5355-7388; DEL SORDO, Stefano/0000-0002-3340-1404; Palazzi, Eliana/0000-0002-8691-7666; Masetti, Nicola/0000-0001-9487-7740 NR 42 TC 4 Z9 4 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2004 VL 423 IS 2 BP 651 EP 656 DI 10.1051/0004-6361:20040210 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850OD UT WOS:000223621400031 ER PT J AU Vrsnak, B Ruzdjak, D Sudar, D Gopalswasmy, N AF Vrsnak, B Ruzdjak, D Sudar, D Gopalswasmy, N TI Kinematics of coronal mass ejections between 2 and 30 solar radii - What can be learned about forces governing the eruption? SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE magnetohydrodynamics (MHD); Sun : corona; Sun : coronal mass ejections (CMEs); Sun : solar-terrestrial relations; Sun : solar wind; interplanetary medium ID MAGNETIC CLOUD PROPAGATION; MAGNETOHYDRODYNAMIC SIMULATIONS; INNER HELIOSPHERE; SMM OBSERVATIONS; ECLIPTIC-PLANE; NEAR-SUN; PROMINENCE; LASCO; ACCELERATION; TRANSIENTS AB Kinematics of more than 5000 coronal mass ejections (CMEs) measured in the distance range 2-30 solar radii is investigated. A distinct anticorrelation between the acceleration, a, and the velocity, v, is found. In the linear form, it can be represented as a = -k(1) (nu - nu(o)), where nu(o) = 400 km s(-1), i.e., most of CMEs faster than 400 kin s(-1) decelerate, whereas slower ones generally accelerate. After grouping CMEs into the width and mean-distance bins, it was found that the slope k(1) depends on these two parameters: k(1) is smaller for CMEs of larger width and mean-distance. Furthermore, the obtained CME subsets show distinct quadratic-form correlations, of the form a = -k(2)(nu - nu(o))\nu - nu(o)\. The value of k(2) decreases with increasing distance and width, whereas nu(o) increases with the distance and is systematically larger than the slow solar wind speed by 100-200 km s(-1). The acceleration-velocity relationship is interpreted as a consequence of the aerodynamic drag. The excess of nu(o) over the solar wind speed is explained assuming that in a certain fraction of events the propelling force is still acting in the considered distance range. In most events the inferred propelling force acceleration at 10 solar radii ranges between a(L) = 0 and 10 m s(-2), being on average smaller at larger distances. However, there are also events that show a(L) > 50 m s(-2), as well as events indicating a(L) < 0. Implications for the interplanetary motion of CMEs are discussed, emphasizing the prediction of the 1 a.u. arrival time. C1 Fac Geodesy, Hvar Observ, Zagreb 10000, Croatia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Vrsnak, B (reprint author), Fac Geodesy, Hvar Observ, Kaciceva 26, Zagreb 10000, Croatia. EM bvrsnak@geodet.geof.hr NR 49 TC 68 Z9 68 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2004 VL 423 IS 2 BP 717 EP 728 DI 10.1051/0004-6361:20047169 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850OD UT WOS:000223621400037 ER PT J AU Michalek, G Gopalswamy, N Lara, A Manoharan, PK AF Michalek, G Gopalswamy, N Lara, A Manoharan, PK TI Arrival time of halo coronal mass ejections in the vicinity of the Earth SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE Sun : coronal mass ejections (CMEs) ID INTERPLANETARY SHOCKS; EVENTS; 1-AU AB We describe an empirical model to predict the 1-AU arrival time of halo CMEs. This model is based on the effective acceleration described by Gopalswamy et a]. (2000a, Geophys. Res. Lett., 27, 145). We verify the Helios/Pioneer Venus Orbiter(PVO) estimation of the effective acceleration profile (Gopalswamy et al. 2001a, J. Geophys. Res., 106, 29207) by considering all full halo CMEs recorded by SOHO/LASCO coronagraphs until the end of 2002. In comparison with previous studies, the present work includes CMEs of a wider range of initial velocities. To improve the accuracy of prediction, we propose to introduce the effective acceleration from two groups of CMEs only, which are expected to have no acceleration cessation at any place between the Sun and Earth. In addition, we consider acceleration cessation distance dependent on initial velocities of a given event CME. For a detailed analysis of this model, we examine projected sky-plane and space speeds (Michalek et al. 2003, ApJ, 584, 472) of CMEs. We show that a correct acceleration profile is crucial for the estimation of 1 AU arrival time of halo CMEs. We estimate that the CME arrival times can be predicted with an average error of 9 and 11 for space and sky-plane initial velocities, respectively. C1 Jagiellonian Univ, Astron Observ, Krakow, Poland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Washington, DC 20064 USA. Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico. RP Michalek, G (reprint author), Jagiellonian Univ, Astron Observ, Krakow, Poland. EM michalek@oa.uj.edu.pl RI Gopalswamy, Nat/D-3659-2012; OI Lara, Alejandro/0000-0001-6336-5291; Manoharan, Periasamy K/0000-0003-4274-211X NR 22 TC 41 Z9 43 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 AUG PY 2004 VL 423 IS 2 BP 729 EP 736 DI 10.1051/0004-6361:20047184 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850OD UT WOS:000223621400038 ER PT J AU Strong, AW Moskalenko, IV Reimer, O Digel, S Diehl, R AF Strong, AW Moskalenko, IV Reimer, O Digel, S Diehl, R TI The distribution of cosmic-ray sources in the Galaxy, gamma-rays and the gradient in the CO-to-H(2) relation SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays; galactic structure; interstellar medium; cosmic rays; supernova remnants; pulsars ID ABUNDANCE GRADIENTS; RADIAL-DISTRIBUTION; GALACTIC-CENTER; MOLECULAR GAS; MILKY-WAY; EMISSION; DISK; METALLICITY; CLOUDS; H-2 AB We present a solution to the apparent discrepancy between the radial gradient in the diffuse Galactic gamma-ray emissivity and the distribution of supernova remnants, believed to be the sources of cosmic rays. Recent determinations of the pulsar distribution have made the discrepancy even more apparent. The problem is shown to be plausibly solved by a variation in the W(CO)-to-N(H(2)) scaling factor. If this factor increases by a factor of 5-10 from the inner to the outer Galaxy, as expected from the Galactic metallicity gradient, we show that the source distribution required to match the radial gradient of gamma-rays can be reconciled with the distribution of supernova remnants as traced by current studies of pulsars. 'The resulting model fits the EGRET gamma-ray profiles extremely well in longitude, and reproduces the mid-latitude inner Galaxy intensities better than previous models. C1 Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Ruhr Univ Bochum, D-44780 Bochum, Germany. Stanford Univ, WW Hansen Expt Phys Lab, Stanford, CA 94305 USA. RP Strong, AW (reprint author), Max Planck Inst Extraterr Phys, Postfach 1312, D-85741 Garching, Germany. EM aws@mpe.mpg.de RI Moskalenko, Igor/A-1301-2007; Reimer, Olaf/A-3117-2013 OI Moskalenko, Igor/0000-0001-6141-458X; Reimer, Olaf/0000-0001-6953-1385 NR 30 TC 120 Z9 120 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 AUG PY 2004 VL 422 IS 3 BP L47 EP L50 DI 10.1051/0004-6361:20040172 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 851BD UT WOS:000223659500001 ER PT J AU Habbal, SR Woo, R AF Habbal, SR Woo, R TI The solar wind and the Sun-Earth link SO ASTRONOMY & GEOPHYSICS LA English DT Article ID ULTRAVIOLET CORONAGRAPH SPECTROMETER; MAGNETIC-FIELD; ALFVEN WAVES; EMISSION-LINE; ACCELERATION; POLARIZATION; OSCILLATIONS; EVOLUTION; MINIMUM; REGION AB The solar wind fills the space between the Sun and its planets, shapes the planetary environments and the heliosphere, and comes to a screeching halt at the heliopause, the boundary with the interstellar medium. This tenuous medium is a fertile environment for exotic plasma processes, most of which are not fully understood. It also holds the intimate secrets of the mechanisms heating the corona that continue to elude us. As the only accessible space plasma laboratory, we must continue its exploration in search of the processes that impact the Earth's environment and govern the evolution of stars and their planetary systems. C1 Univ Coll Wales, Dept Phys, Aberystwyth SY23 3BZ, Dyfed, Wales. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Habbal, SR (reprint author), Univ Coll Wales, Dept Phys, Aberystwyth SY23 3BZ, Dyfed, Wales. NR 59 TC 2 Z9 2 U1 0 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1366-8781 J9 ASTRON GEOPHYS JI Astron. Geophys. PD AUG PY 2004 VL 45 IS 4 BP 38 EP 43 DI 10.1046/j.1468-4004.2003.45438.x PG 6 WC Astronomy & Astrophysics; Geochemistry & Geophysics SC Astronomy & Astrophysics; Geochemistry & Geophysics GA 841WV UT WOS:000222963600012 ER PT J AU Henriksen, MJ Hudson, DS Tittley, E AF Henriksen, MJ Hudson, DS Tittley, E TI A soft X-ray excess in the A754 cluster SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (A754); X-rays : galaxies : clusters ID EARLY-TYPE GALAXIES; TIMING-EXPLORER; NONTHERMAL EMISSION; BEPPOSAX OBSERVATION; TEMPERATURE MAP; EMITTING GAS; COMA CLUSTER; XMM-NEWTON; RADIO HALO; CHANDRA AB We have analyzed the Chandra, BeppoSAX, ASCA, and ROSAT PSPC observations of A754 and report evidence of a soft, diffuse X-ray component. A radial analysis shows that it is detected within a region that extends out to 80 from the X-ray center and that the emission is higher in the central region of the cluster. Fitting a thermal model to the combined BeppoSAX and PSPC spectra show excess emission below 1 keV in the PSPC and above 100 keV in the BeppoSAX PDS. The source, 26W20, is in the field of view of the PDS. The addition of a power law, with the spectral parameters measured by Silverman et al. in 1998 for 26W20, successfully models the hard component in the PDS. The excess soft emission can be attributed to a low-temperature, 0.77-1.21 keV, component. The soft excess is also modeled with a power law, although the 90% uncertainty for the normalization of the power law is consistent with zero. Either component added to a hot thermal component provides a statistically significant improvement over a single hot thermal component. The Chandra temperature map provides a detailed description of the thermal state of the gas on a scale of 100 kpc and larger and does not show any region cooler than 5.9 keV ( 90% confidence) within the region where the cool component was detected. Calculations of the expected emission from one or more groups randomly embedded in a hot gas component were performed that demonstrate that groups are a plausible source of similar to 1 keV emission, in that they can match the measured cool-component luminosity without violating the spatial temperature constraints provided by the temperature map. The cool component is centrally peaked in the cluster, and the gas density and temperature are relatively high, arguing against the warm hot intergalactic medium as the source of the X-ray emission. Furthermore, because the cool component is centrally peaked, the groups are likely embedded in the intracluster gas, rather than in the intercluster gas. The typical X-ray emission from early-type galaxies is not high enough to provide the total cool-component luminosity, 2.1 x 10(43) ergs s(-1). The peak of the cool component is located between the low-frequency radio halos, thus arguing against a nonthermal interpretation for the emission based on the synchrotron inverse Compton model, which requires that the nonthermal X-ray and radio emission be cospatial. Thus, we conclude that emission from embedded groups is the most likely origin of the cool component in A754. C1 Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Henriksen, MJ (reprint author), Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, 1000 Hilltop Circle, Baltimore, MD 21250 USA. NR 45 TC 3 Z9 3 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2004 VL 610 IS 2 BP 762 EP 771 DI 10.1086/420810 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840AE UT WOS:000222828600013 ER PT J AU Snowden, SL Collier, MR Kuntz, KD AF Snowden, SL Collier, MR Kuntz, KD TI XMM-Newton observation of solar wind charge exchange emission SO ASTROPHYSICAL JOURNAL LA English DT Article DE interplanetary medium; solar system : general; X-rays : general ID X-RAY-EMISSION; ROSAT SURVEY; MAPS; IONS; HELIOSPHERE; NEUTRALS; SPECTRA AB We present an XMM-Newton spectrum of diffuse X-ray emission from within the solar system. The spectrum is dominated by probable C VI lines at 0.37 and 0.46 keV, an O VII line at 0.56 keV, O VIII lines at 0.65 and similar to0.8 keV, Ne IX lines at similar to0.92 keV, and Mg XI lines at similar to1.35 keV. This spectrum is consistent with that expected from charge exchange emission between the highly ionized solar wind and either interstellar neutrals in the heliosphere or material from Earth's exosphere. The emission is clearly seen as a low-energy (E<1.5 keV) spectral enhancement in one of a series of four observations of the Hubble Deep Field-North. The X-ray enhancement is concurrent with an enhancement in the solar wind measured by Advanced Composition Explorer, Wind, and Solar and Heliospheric Observatory spacecraft. The solar wind enhancement reaches a flux level an order of magnitude more intense than typical fluxes at 1 AU and has a significantly enhanced O+7/O+6 ratio. Besides being of interest in its own right for studies of the solar system, this emission can have significant consequences for observations of cosmological objects. It can provide emission lines at zero redshift, which are of particular interest in studies of diffuse thermal emission (e.g., O VII and O VIII), and which can therefore act as contamination in the spectra of objects that cover the entire detector field of view. We propose the use of solar wind monitoring data as a diagnostic to screen for such possibilities. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Astron, Baltimore, MD 21250 USA. RP Snowden, SL (reprint author), Univ Space Res Assoc, Columbia, MD 21044 USA. EM snowden@riva.gsfc.nasa.gov RI Snowden, Steven/D-5292-2012; Collier, Michael/I-4864-2013 OI Collier, Michael/0000-0001-9658-6605 NR 30 TC 161 Z9 161 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 AUG 1 PY 2004 VL 610 IS 2 BP 1182 EP 1190 DI 10.1086/421841 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840AE UT WOS:000222828600049 ER PT J AU Arzoumanian, Z Safi-Harb, S Landecker, TL Kothes, R AF Arzoumanian, Z Safi-Harb, S Landecker, TL Kothes, R TI A central X-ray source in the nonthermal radio nebula DA 495 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (DA 495, G65.7+1.2); radiation mechanisms : nonthermal; stars : neutron; supernova remnants; X-rays : ISM ID SUPERNOVA-REMNANTS; YOUNG PULSARS AB We report the detection, in archival ROSAT and ASCA observations, of X-ray emission from the direction of DA 495 (G65.7 + 1.2), a likely supernova remnant of uncertain classification but with similarities to the Crab Nebula. An unusual feature of the radio nebula is its annular morphology, with a flux minimum at the geometrical center. In the soft X-ray band, the ROSAT data reveal a compact source near the edge of the central radio "hole"; the hard X-ray morphology, at the limit of ASCA's angular resolution, is suggestive of extended emission coincident with the ROSAT source. The X-ray flux is roughly constant with time, and its spectrum is well described by a power law with photon index similar to1.7. Taken together, this evidence suggests identification of the X-ray source with a magnetospherically active neutron star and its associated wind nebula. Timing analysis of the ASCA data yields only a weak upper bound on pulsations with periods greater than or similar to30 ms. These results reveal for the first time the high-energy engine that powers the DA 495 radio nebula and strengthen its classification as a plerionic supernova remnant, one that may represent the poorly explored late evolutionary stages of Crab-like nebulae. C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, LHEA, Greenbelt, MD 20771 USA. Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada. Natl Res Council Canada, Herzberg Inst Astrophys, Dominion Radio Astrophys Observ, Penticton, BC V2A 6J9, Canada. Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, Canada. RP Arzoumanian, Z (reprint author), NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, LHEA, Code 662, Greenbelt, MD 20771 USA. EM zaven@milkyway.gsfc.nasa.gov; safiharb@cc.umanitoba.ca; tom.landecker@nrc-cnrc.gc.ca; roland.kothes@nrc-cnrc.gc.ca NR 19 TC 3 Z9 3 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2004 VL 610 IS 2 BP L101 EP L104 DI 10.1086/423338 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840AF UT WOS:000222828700008 ER PT J AU Smith, N Morse, JA Collins, NR Gull, TR AF Smith, N Morse, JA Collins, NR Gull, TR TI The purple haze of eta Carinae: Binary-induced variability? SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; circumstellar matter; stars : individual (eta Carinae); stars : winds, outflows; ultraviolet : stars ID HOMUNCULUS NEBULA; INFRARED MORPHOLOGY; RADIO OUTBURST; ULTRAVIOLET; HYPOTHESIS; PARAMETERS; COMPANION; DISCOVERY; EVOLUTION; TORUS AB Asymmetric variability in ultraviolet images of the Homunculus obtained with the Advanced Camera for Surveys/High Resolution Camera on the Hubble Space Telescope suggests that eta Carinae is indeed a binary system. Images obtained before, during, and after the recent "spectroscopic event" in 2003.5 show alternating patterns of bright spots and shadows on opposite sides of the star before and after the event, providing a strong geometric argument for an azimuthally evolving, asymmetric UV radiation field as one might predict in some binary models. The simplest interpretation of these UV images, where excess UV escapes from the secondary star in the direction away from the primary, places the major axis of the eccentric orbit roughly perpendicular to our line of sight, sharing the same equatorial plane as the Homunculus, and with apastron for the hot secondary star oriented toward the southwest of the primary. However, other orbital orientations may be allowed with more complicated geometries. Selective UV illumination of the wind and ejecta may be partly responsible for line profile variations seen in spectra. The brightness asymmetries cannot be explained plausibly with delays due to light-travel time alone, so a single-star model would require a seriously asymmetric shell ejection. C1 Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Smith, N (reprint author), Univ Colorado, Ctr Astrophys & Space Astron, 389 UCB, Boulder, CO 80309 USA. RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 32 TC 51 Z9 51 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2004 VL 610 IS 2 BP L105 EP L108 DI 10.1086/423341 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840AF UT WOS:000222828700009 ER PT J AU Novakov, T Hansen, JE AF Novakov, T Hansen, JE TI Black carbon emissions in the United Kingdom during the past four decades: an empirical analysis SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE black carbon; black smoke; emission trends; sources; technology factor ID AEROSOLS; CHINA; DEPOSITION; SULFATE; SULFUR; HAZE AB We use data from a unique 40-year record of 150 urban and rural stations in the "Black Smoke and SO2 Network" in Great Britain to infer information about sources of atmospheric black carbon (BC). The data show a rapid decline of ambient atmospheric BC between 1962 and the early 1990s that exceeds the decline in official estimates of BC emissions based only on amount of fuel use and mostly fixed emission factors. This provides empirical confirmation of the existence and large impact of a time-dependent "technology factor" that must multiply the rate of fossil fuel use. Current ambient BC amounts in Great Britain comparable to those in western and central Europe, with diesel engines being the principal present source. From comparison of BC and SO2 data we infer that current BC emission inventories understate true emissions in the UK by about a factor of two. The results imply that there is the potential for improved technology to achieve large reduction of global ambient BC. There is a need for comparable monitoring of BC in other countries. (C) 2004 Elsevier Ltd. All rights reserved. C1 Lawrence Berkeley Lab, Environnm Energy Technol Div, Berkeley, CA 94720 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Lawrence Berkeley Lab, Environnm Energy Technol Div, MS-70-180B, Berkeley, CA 94720 USA. EM tnovakov@lbl.gov NR 27 TC 19 Z9 22 U1 0 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 EI 1873-2844 J9 ATMOS ENVIRON JI Atmos. Environ. PD AUG PY 2004 VL 38 IS 25 BP 4155 EP 4163 DI 10.1016/j.atmosenv.2004.04.031 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 838ID UT WOS:000222706000007 ER PT J AU Caceres, L Delatorre, J Gomez-Silva, B Rodriguez, V McKay, CP AF Caceres, L Delatorre, J Gomez-Silva, B Rodriguez, V McKay, CP TI Atmospheric moisture collection from a continuous air flow through a refrigerated coil tube SO ATMOSPHERIC RESEARCH LA English DT Article DE atmospheric water collection; atmospheric moisture; air quality; Atacama Desert ID CHEMICAL-COMPOSITION; FOG; AEROSOL; CLOUDS; WATER AB A controlled airflow circulating through a coil tube maintained at sub-ambient temperatures allows moisture to condense as water droplets with subsequent adhesion onto the internal tube walls. At the same time, water droplets scavenge fine particulate matter and dissolve a fraction of the gaseous pollutants. The accumulated water in the coil is amenable for collection and chemical inspection to yield information about the presence of pollutants in the air. Based on this principle, an experimental apparatus was developed to collect and analyze ambient humidity at different sites of the Atacama Desert in Northern Chile. Moisture collection experiments lasting from 3 to 24 h were carried out with condensing temperatures ranging from -20 to 0 degreesC. Under all experimental conditions, the amount of collected water was between 60% and 90% of the total removable water. Sodium was present in all collected water samples and reached values up to 4 g l(-1). Practical details, theoretical considerations and the potential use of the proposed method in characterizing specific air pollutants are discussed. (C) 2004 Elsevier B.V. All rights. reserved. C1 Univ Antofagasta, Antofagasta, Chile. Univ Arturo Prat, Ctr Invest Hombre Desierto, Iquique, Chile. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP McKay, CP (reprint author), Univ Antofagasta, Avenida Angamos 601, Antofagasta, Chile. EM cmckay@arc.nasa.gov NR 20 TC 6 Z9 7 U1 1 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 J9 ATMOS RES JI Atmos. Res. PD AUG-SEP PY 2004 VL 71 IS 3 BP 127 EP 137 DI 10.1016/j.atmoares.2004.03.008 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 854KE UT WOS:000223900700002 ER PT J AU Schmidt, LL Wood, J Lugg, DJ AF Schmidt, LL Wood, J Lugg, DJ TI Team climate at Antarctic research stations 1996-2000: Leadership matters SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE Antarctic; leadership effectiveness; social isolation; demographic diversity; group cohesion ID WORK-GROUP DIVERSITY; PERFORMANCE; GENDER; ENVIRONMENTS; PSYCHOLOGY; TIME; TASK; TOP AB Introduction: The popular assumption is that extreme environments induce a climate of hostility, incompatibility, and tension by intensifying differences and disagreements among team members. Team members' perceptions of team climate are likely to change over time in an extreme environment, and thus team climate should be considered as a dynamic outcome variable resulting from multiple factors. In order to explore team climate as a dynamic outcome, we explored whether variables at multiple levels of analysis contributed to team climate over time for teams living and working in Antarctica. Method: Data for this study were collected from volunteers involved in Australian National Antarctic Research Expeditions conducted from 1996 to 2000. Multilevel analysis was used to partition and estimate the variance in team climate and to explore factors explaining variance at the group/team, individual, and weekly levels. Results: Most of the variance in perceptions of team climate was at the individual level (57%). Team climate had less variance at the group level (16%) and at the weekly level (26%). Results indicated that perceived leadership effectiveness was significantly related to team climate. Perceived leadership effectiveness accounted for an estimated 77% of the group level variance, which equated to 14% of the overall variance in team climate. Discussion: Our results suggest that exploring the characteristics and behaviors that constitute effective leadership would contribute to a more complete and useful picture of team climate, as well as guide selection research. C1 NASA, JSC, Biobehav Lab, Houston, TX 77058 USA. NASA, HQ, Off Chief Med Officer, Washington, DC 20546 USA. Univ Houston, Dept Psychol, Houston, TX USA. RP Wood, J (reprint author), NASA, JSC, Biobehav Lab, SK3,Nasa Rd 1, Houston, TX 77058 USA. EM jwood@ems.jsc.nasa.gov NR 38 TC 8 Z9 8 U1 2 U2 9 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD AUG PY 2004 VL 75 IS 8 BP 681 EP 687 PG 7 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 842KY UT WOS:000223004200006 PM 15328785 ER PT J AU Reschke, M Somers, JT Leigh, RJ Krnavek, JM Kornilova, L Kozlovskaya, I Bloomberg, JJ Paloski, WH AF Reschke, M Somers, JT Leigh, RJ Krnavek, JM Kornilova, L Kozlovskaya, I Bloomberg, JJ Paloski, WH TI Sensorimotor recovery following Spaceflight may be due to frequent square-wave saccadic intrusions SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE adaptation; gaze-holding; astronaut; long duration; dynamic visual acuity; dynamic posture ID EYE-MOVEMENT; JERKS AB Square-wave jerks (SWJs) are small, involuntary saccades that disrupt steady fixation. We report the case of an astronaut (approximately 140 d on orbit) who showed frequent SWJs, especially postflight, but who showed no impairment of vision or decrement of postflight performance. These data support the view that SWJs do not impair vision because they are paired movements, consisting of a small saccade away from the fixation position followed, within 200 ms, by a corrective saccade that brings the eye back on target. Since many returning astronauts show a decrement of dynamic visual function during postflight locomotion, it seems possible that frequent SWJs improved this astronaut's visual function by providing postsaccadic enhancement of visual fixation, which aided postflight performance. Certainly, frequent SWJs did not impair performance in this astronaut, who had no other neurological disorder. C1 NASA, Lyndon B Johnson Space Ctr, Neurosci Labs, Houston, TX 77058 USA. Minist Hlth Russian Federat, Inst Biomed Problems, Moscow, Russia. Case Western Reserve Univ, Univ Hosp, Cleveland, OH 44106 USA. Dept Vet Affairs Med Ctr, Dept Neurol, Cleveland, OH USA. Dept Vet Affairs Med Ctr, Dept Biomed Engn, Cleveland, OH USA. Dept Vet Affairs Med Ctr, Dept Neurosci, Cleveland, OH USA. Wyle Labs, Houston, TX USA. RP Reschke, M (reprint author), NASA, Lyndon B Johnson Space Ctr, Neurosci Labs, 2101 NASA Pkwy,Mail Code SK3, Houston, TX 77058 USA. EM millard.f.reschke@nasa.gov RI Kozlovskaya, Inesa/R-9729-2016 FU NEI NIH HHS [EY06717] NR 21 TC 5 Z9 5 U1 0 U2 2 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD AUG PY 2004 VL 75 IS 8 BP 700 EP 704 PG 5 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 842KY UT WOS:000223004200010 PM 15328789 ER PT J AU Lee, JS Ray, RI Lemieux, EJ Falster, AU Little, BJ AF Lee, JS Ray, RI Lemieux, EJ Falster, AU Little, BJ TI An evaluation of carbon steel corrosion under stagnant seawater conditions SO BIOFOULING LA English DT Article DE seawater; aerobic; anaerobic; sulphate-reducing bacteria ID SULFATE-REDUCING BACTERIA; DISSOLVED-OXYGEN CONCENTRATION; UNDERNEATH AEROBIC BIOFILMS; MILD-STEEL; STAINLESS-STEEL; COPPER; SYSTEM AB Corrosion of 1020 carbon steel coupons in natural seawater over a 1-year period was more aggressive under strictly anaerobic stagnant conditions than under aerobic stagnant conditions as measured by weight loss and instantaneous corrosion rate (polarization resistance). Under oxygenated conditions, a two-tiered oxide layer of lepidocrocite/goethite formed. The inner layer was extremely tenacious and resistant to acid cleaning. Under anaerobic conditions, the corrosion product was initially a non-tenacious sulphur-rich corrosion product, mackinawite, with enmeshed bacteria. As more sulphide was produced the mackinawite was transformed to pyrrhotite. In both aerobic and anaerobic exposures, corrosion was more aggressive on horizontally oriented coupons compared to vertically oriented samples. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Naval Res Lab, Key West, FL 33040 USA. Univ New Orleans, New Orleans, LA 70148 USA. RP Lee, JS (reprint author), USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. EM jlee@nrlssc.navy.mil NR 28 TC 22 Z9 22 U1 0 U2 5 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0892-7014 J9 BIOFOULING JI Biofouling PD AUG-OCT PY 2004 VL 20 IS 4-5 BP 237 EP 247 DI 10.1080/08927010400013274 PG 11 WC Biotechnology & Applied Microbiology; Marine & Freshwater Biology SC Biotechnology & Applied Microbiology; Marine & Freshwater Biology GA 882GD UT WOS:000225926300006 PM 15621645 ER PT J AU Sigler, MF Womble, JN Vollenweider, JJ AF Sigler, MF Womble, JN Vollenweider, JJ TI Availability to Steller sea lions (Eumetopias jubatus) of a seasonal prey resource: a prespawning aggregation of eulachon (Thaleichthys pacificus) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID FORAGE FISH; ALASKA; DIET; REPRODUCTION; PREDATORS; DECLINE AB The availability of seasonally abundant energy-rich prey can be a significant factor for the survival and reproductive success of predator populations. Large numbers of Steller sea lions (Eumetopias jubatus) were attracted to a prespawning aggregation of eulachon (Thaleichthys pacificus) in Berners Bay in southeast Alaska during April-May in 2002 and 2003. Sea lion abundance increased as eulachon gathered in Berners Bay, peaked as eulachon abundance peaked, and decreased as the eulachon moved up-river. As sea lion abundance increased in Berners Bay, sea lion abundance decreased at Benjamin Island, a sea lion haulout located 22 km away. The eulachon provided an abundant, energy-rich, predictable prey source for the Steller sea lions: (i) eulachon energy density was 9.70 +/- 0.24 kJ.g(-1), much higher than that of any forage species reported in the North Pacific Ocean except northern lampfish (Stenobrachius leucopsarus); (ii) a large surplus of prey was available per sea lion while the eulachon aggregation was present; and (iii) the spawning run usually begins between late April and early May. The eulachon pulse may be critical to Steller sea lions during a period of high energetic demands. C1 Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. Univ Alaska Fairbanks, Sch Fisheries & Ocean Sci, Juneau, AK 99801 USA. RP Sigler, MF (reprint author), Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM mike.sigler@noaa.gov NR 30 TC 35 Z9 36 U1 1 U2 7 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD AUG PY 2004 VL 61 IS 8 BP 1475 EP 1484 DI 10.1139/F04-086 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 869IO UT WOS:000224976800012 ER PT J AU Teillet, PM Helder, DL Ruggles, TA Landry, R Ahern, FJ Higgs, NJ Barsi, J Chander, G Markham, BL Barker, JL Thome, KJ Schott, JR Palluconi, FD AF Teillet, PM Helder, DL Ruggles, TA Landry, R Ahern, FJ Higgs, NJ Barsi, J Chander, G Markham, BL Barker, JL Thome, KJ Schott, JR Palluconi, FD TI A definitive calibration record for the Landsat-5 thematic mapper anchored to the Landsat-7 radiometric scale SO CANADIAN JOURNAL OF REMOTE SENSING LA English DT Article ID CROSS-CALIBRATION; TM; ETM+; INSTRUMENTS; SENSORS AB A coordinated effort on the part of several agencies has led to the specification of a definitive radiometric calibration record for the Landsat-5 thematic mapper (TM) for its lifetime since launch in 1984. The time-dependent calibration record for Landsat-5 TM has been placed on the same radiometric scale as the Landsat-7 enhanced thematic mapper plus (ETM+). It has been implemented in the National Landsat Archive Production Systems (NLAPS) in use in North America. This paper documents the results of this collaborative effort and the specifications for the related calibration processing algorithms. The specifications include (i) anchoring of the Landsat-5 TM calibration record to the Landsat-7 ETM+ absolute radiometric calibration, (ii) new time-dependent calibration processing equations and procedures applicable to raw Landsat-5 TM data, and (iii) algorithms for recalibration computations applicable to some of the existing processed datasets in the North American context. The cross-calibration between Landsat-5 TM and Landsat-7 ETM+ was achieved using image pairs from the tandem-orbit configuration period that was programmed early in the Landsat-7 mission. The time-dependent calibration for Landsat-5 TM is based on a detailed trend analysis of data from the on-board internal calibrator. The new lifetime radiometric calibration record for Landsat-5 will overcome problems with earlier product generation owing to inadequate maintenance and documentation of the calibration over time and will facilitate the quantitative examination of a continuous, near-global dataset at 30-m scale that spans almost two decades. C1 Nat Reources Canada, Canada Ctr Remote Sensing, Ottawa, ON K1A 0Y7, Canada. S Dakota State Univ, Dept Elect Engn, Brookings, SD 57007 USA. TerreVista Earth Imaging, Cormac, ON J0J 1M0, Canada. MacDonald Dettwiler & Associates Ltd, Richmond, BC V6V 2J3, Canada. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. US Geol Survey, EROS Data Ctr, Sci Applicat Int Corp, Sioux Falls, SD 57198 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA. Rochester Inst Technol, Ctr Imaging Sci, Rochester, NY 14623 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. RP Teillet, PM (reprint author), Nat Reources Canada, Canada Ctr Remote Sensing, 588 Booth St, Ottawa, ON K1A 0Y7, Canada. EM Phil.Teillet@ccrs.nrcan.gc.ca RI Thome, Kurtis/D-7251-2012; Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 26 TC 25 Z9 28 U1 0 U2 3 PU CANADIAN AERONAUTICS SPACE INST PI OTTAWA PA 1685 RUSSELL RD, UNIT 1-R, OTTAWA, ON K1G 0N1, CANADA SN 0703-8992 J9 CAN J REMOTE SENS JI Can. J. Remote Sens. PD AUG PY 2004 VL 30 IS 4 BP 631 EP 643 PG 13 WC Remote Sensing SC Remote Sensing GA 858KE UT WOS:000224189900005 ER PT J AU Convertino, VA Ratliff, DA Ryan, KL Cooke, WH Doerr, DE Ludwig, DA Muniz, GW Britton, DL Clah, SD Fernald, KB Ruiz, AF Idris, A Lurie, KG AF Convertino, VA Ratliff, DA Ryan, KL Cooke, WH Doerr, DE Ludwig, DA Muniz, GW Britton, DL Clah, SD Fernald, KB Ruiz, AF Idris, A Lurie, KG TI Effects of inspiratory impedance on the carotid-cardiac baroreflex response in humans SO CLINICAL AUTONOMIC RESEARCH LA English DT Article DE heart rate; blood pressure; baroreflex function; baroreceptor resetting; respiratory resistance ID DECOMPRESSION CARDIOPULMONARY-RESUSCITATION; ORTHOSTATIC HYPOTENSION; THRESHOLD VALVE; BLOOD-PRESSURE; BARORECEPTOR REFLEX; AUTONOMIC FUNCTIONS; PULSATILE PRESSURE; VAGAL BAROREFLEX; EXERCISE; DOGS AB We were interested in a therapeutic device designed to increase carotid-cardiac baroreflex sensitivity (BRS) since high BRS is associated with a lower risk for development of hypotension in humans with experimentally-induced central hypovolemia. We hypothesized that spontaneous breathing through an impedance threshold device (ITD) designed to increase negative intrathoracic pressure during inspiration and elevate arterial blood pressure would acutely increase BRS in humans. We tested this hypothesis by measuring heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressures, and carotid-cardiac BRS in 10 female and 10 male subjects breathing through a face mask at three separate ITD conditions: (a) 6 cm H2O; (b) 12 cm H2O; and (c) a control (0 cm H2O). HR was increased (P = 0.013) from 64 +/- 3 bpm during control to 68 +/- 3 bpm at 6 cm H2O ITD and 71 +/- 4 bpm at 12 cm H2O ITD breathing conditions. During ITD breathing, BRS was not altered but responses were shifted to higher arterial pressures. However, SBP and DBP were elevated for both the 6 and 12 cm H2O conditions compared to the 0 cm H2O condition, but returned to control (sham) levels by 30 minutes after cessation of ITD breathing. There were no gender effects for BRS or any hemodynamic responses to breathing through the ITD. We conclude that breathing with inspiratory impedance at relatively low pressures can increase baseline arterial blood pressure, i.e., reset the operational point for SBP on the baroreflex stimulus-response relationship, in healthy subjects. This resetting of the cardiac baroreflex may represent a mechanism that allows blood pressure to increase without a reflex-mediated reduction in HR. C1 USA, Inst Surg Res, Ft Sam Houston, TX 78234 USA. NASA, Bionet Corp, Kennedy Space Ctr, FL 32899 USA. NASA, Biol & Chem Labs Branch, Kennedy Space Ctr, FL 32899 USA. Med Coll Georgia, Georgia Prevent Inst, Dept Pediat, Augusta, GA 30912 USA. Profess Performance Dev Grp Inc, San Antonio, TX USA. NASA, Spaceflight & Life Sci Training Program, Kennedy Space Ctr, FL 32899 USA. RP Convertino, VA (reprint author), USA, Inst Surg Res, 3400 Rawley E Chambers Ave,Bldg 3611, Ft Sam Houston, TX 78234 USA. EM victor.convertino@amedd.army.mil OI Idris, Ahamed/0000-0001-7113-6499 NR 33 TC 22 Z9 22 U1 0 U2 0 PU DR DIETRICH STEINKOPFF VERLAG PI DARMSTADT PA PO BOX 10 04 62, D-64204 DARMSTADT, GERMANY SN 0959-9851 J9 CLIN AUTON RES JI Clin. Auton. Res. PD AUG PY 2004 VL 14 IS 4 BP 240 EP 248 DI 10.1007/s10286-004-0180-4 PG 9 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA 851DM UT WOS:000223665600010 PM 15316841 ER PT J AU Ambur, DR Jaunky, N Hilburger, MW AF Ambur, DR Jaunky, N Hilburger, MW TI Progressive failure studies of stiffened panels subjected to shear loading SO COMPOSITE STRUCTURES LA English DT Article DE progressive failure; ply damage mode; buckling; postbuckling; video image correlation; stitched composites ID POSTBUCKLING RESPONSE; LAMINATED COMPOSITES; DAMAGE MODEL; PLATES; COMPRESSION; PREDICTION AB Experimental and analytical results are presented for progressive failure of stiffened composite panels with and without a notch and subjected to in-plane shear loading well into the postbuckling regime. Initial geometric imperfections are included in the finite element models. Ply damage modes such as matrix cracking, fiber-matrix shear, and fiber failure are modeled by degrading the material properties. Experimental results from the test include strain full-field data from a video image correlation system in addition to other strain and displacement measurements. Results from nonlinear finite element analyses are compared with experimental data. Good agreement between experimental data and numerical results is observed for the stitched stiffened composite panels studied. (C) 2003 Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. Natl Inst Aerosp, Hampton, VA 23666 USA. RP Ambur, DR (reprint author), NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. EM d.r.ambur@larc.nasa.gov NR 22 TC 25 Z9 30 U1 1 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0263-8223 J9 COMPOS STRUCT JI Compos. Struct. PD AUG PY 2004 VL 65 IS 2 BP 129 EP 142 DI 10.1016/S0263-8223(03)00153-3 PG 14 WC Materials Science, Composites SC Materials Science GA 844KU UT WOS:000223157800001 ER PT J AU Ambur, DR Jaunky, N Hilburger, M Davila, CG AF Ambur, DR Jaunky, N Hilburger, M Davila, CG TI Progressive failure analyses of compression-loaded composite curved panels with and without cutouts SO COMPOSITE STRUCTURES LA English DT Article ID POSTBUCKLING RESPONSE; LAMINATED COMPOSITES; DAMAGE MODEL; PLATES; PREDICTION; BEHAVIOR; SHEAR AB Progressive failure analyses results are presented for composite curved panels with and without a circular cutout and subjected to axial compression loading well into their postbuckling regime. Ply damage modes such as matrix cracking, fiber-matrix shear, and fiber failure are modeled by degrading the material properties. Results from finite element analyses are compared with experimental data. Good agreement between experimental data and numerical results are observed for most part of the loading range for the structural configurations considered. Modeling of initial geometric imperfections may be required to obtain accurate analysis results depending on the ratio of the cutout width to panel width. (C) 2003 Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Analyt & Computat Methods Branch, Hampton, VA 23681 USA. RP Ambur, DR (reprint author), NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. EM d.r.ambur@larc.nasa.gov RI Davila, Carlos/D-8559-2011 NR 23 TC 30 Z9 31 U1 0 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0263-8223 J9 COMPOS STRUCT JI Compos. Struct. PD AUG PY 2004 VL 65 IS 2 BP 143 EP 155 DI 10.1016/S0263-8223(03)00184-3 PG 13 WC Materials Science, Composites SC Materials Science GA 844KU UT WOS:000223157800002 ER PT J AU Fang, B Kelkar, AG Joshi, SM Pota, HR AF Fang, B Kelkar, AG Joshi, SM Pota, HR TI Modelling, system identification, and control of acoustic-structure dynamics in 3-D enclosures SO CONTROL ENGINEERING PRACTICE LA English DT Article DE active noise control; acoustic-structure interaction; modelling and control; broadband control; acoustic modelling ID SOUND AB This paper addresses modelling, system identification, and control of acoustic structure interaction dynamics for 3-D enclosures. The specific configuration of interest is the one in which an acoustic disturbance is created by one of the vibrating boundaries of the enclosure such as in the case of aircraft cabin noise. The modelling techniques developed in this paper can be used to obtain finitedimensional approximate models (time-domain as well as frequency-domain) suitable for control design. The mathematical modelling approach presented in this paper can be extended to model a broad class of acoustic-structure systems. The modelling methodology is demonstrated on a 3-D acoustic enclosure built in laboratory for experimental verification. The analytical model is compared with the experimental data. The transfer function and state-space models are also obtained from experimental data using system identification techniques. Differences in analytical and experimentally identified models are discussed and control design strategies along with experimental results are presented for broadband reduction of noise. (C) 2004 Elsevier Ltd. All rights reserved. C1 Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. NASA, Langley Res Ctr, Dynam & Control Branch, Hampton, VA 23681 USA. UNSW, Australian Def Force Acad, Sch Elect Engn, Canberra, ACT 2600, Australia. RP Kelkar, AG (reprint author), Iowa State Univ, Dept Mech Engn, 2018 Black, Ames, IA 50011 USA. EM bfang@iastate.edu; akelkar@iastate.edu; s.m.joshi@larc.nasa.gov; h-pota@adfa.edu.au OI Pota, Hemanshu/0000-0002-9612-714X NR 31 TC 20 Z9 21 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0661 J9 CONTROL ENG PRACT JI Control Eng. Practice PD AUG PY 2004 VL 12 IS 8 BP 989 EP 1004 DI 10.1016/j.conengprac.2003.10.003 PG 16 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA 831YD UT WOS:000222231900006 ER PT J AU Baker, JD AF Baker, JD TI Evaluation of closed capture-recapture methods to estimate abundance of Hawaiian monk seals SO ECOLOGICAL APPLICATIONS LA English DT Article DE abundance estimation; bias; capture heterogeneity; capture-recapture; Hawaiian monk seal; Monachus schauinslandi; validation studies ID ESTIMATING POPULATION-SIZE; PROBABILITIES VARY; MONACHUS-SCHAUINSLANDI; BEHAVIORAL-RESPONSE; ANIMAL POPULATIONS; ROBUST ESTIMATION; MODELS AB Numerous capture-recapture methods have been developed to estimate abundance, yet the performance of these models is only rarely judged by comparison with true abundance. This study presents a rare opportunity to assess capture-recapture estimates in a free-ranging population with known minimum abundance. Hawaiian monk seal abundance historically has been characterized using a trend index or has been estimated using simple enumeration. Here, I evaluate the applicability of various closed-population capture-recapture models to estimating Hawaiian monk seal abundance and its associated error. I analyzed 12 data sets (two years from each of six subpopulations) representing a wide variety of sampling and logistical scenarios, using models that explored the effects of animal size class (juvenile, subadult, or adult), tag status, and sighting location on initial capture and recapture probabilities. I also explored various models to account for capture heterogeneity among individuals. Size and sex effects always significantly improved model fits, and tag status and location effects were also frequently influential. In most cases, abundance estimated from capture-recapture models was substantially lower than known minimum abundance, suggesting the influence of individual capture heterogeneity. Attributes of individuals known to be alive, but not captured during systematic surveys, did not reveal patterns that explained sources of capture heterogeneity. In some cases, mixture models produced estimates that were less biased but were associated with very large confidence intervals. Among the model types examined, those available in Program CAPTURE performed best; although they are still prone to negative bias, these models nevertheless may prove useful in characterizing population trends in Hawaiian monk seals. This study demonstrates that selection of appropriate closed capture-recapture models can be substantially improved by independent validation. C1 Natl Marine Fisheries Serv, Honolulu Lab, Pacific Isl Fisheries Sci Ctr, NOAA, Honolulu, HI 96822 USA. Univ Aberdeen, Sch Biol Sci, Lighthouse Field Stn, Cromarty IV11 8YJ, Ross, Scotland. RP Baker, JD (reprint author), Natl Marine Fisheries Serv, Honolulu Lab, Pacific Isl Fisheries Sci Ctr, NOAA, 2570 Dole St, Honolulu, HI 96822 USA. EM jason.baker@noaa.gov NR 40 TC 14 Z9 19 U1 3 U2 12 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 1051-0761 EI 1939-5582 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 2004 VL 14 IS 4 BP 987 EP 998 DI 10.1890/03-5121 PG 12 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 844KI UT WOS:000223156600004 ER PT J AU Haas, HL Rose, KA Fry, B Minello, TJ Rozas, LP AF Haas, HL Rose, KA Fry, B Minello, TJ Rozas, LP TI Brown shrimp on the edge: Linking habitat to survival using an individual-based simulation model SO ECOLOGICAL APPLICATIONS LA English DT Article DE brown shrimp; Gulf of Mexico (USA) fisheries; habitat fragmentation; habitat loss; marsh-edge habitat; management; model; individual-based; simulation model; stable isotopes ID PENAEUS-AZTECUS IVES; SALT-MARSH; NEKTON USE; COASTAL LOUISIANA; PREDATION RATES; FISH PREDATION; TEXAS USA; GROWTH; SETIFERUS; PATTERNS AB In many coastal areas, natural habitats are being fragmented and lost to encroaching human development. These landscape changes can affect the production of recreationally and commercially important fisheries because many exploited species of fish and shellfish are estuarine dependent and utilize coastal marshes as nursery grounds. Brown shrimp are an example of a commercially exploited species that may be highly affected by changes in the spatial distribution of habitat types. We used a spatially explicit, individual-based simulation model to explore the role of marsh vegetation and edge habitat in brown shrimp survival. The model simulated shrimp movement, mortality, and growth of individual shrimp from arrival as postlarvae to 70-mm body length, when they emigrate offshore. Simulations were performed on 100 X 100 m spatial grid of 1-m(2) cells, with each cell labeled as "water" or "vegetation". Predation mortality was influenced by shrimp size, movement, and habitat. Simulated shrimp growth depended on temperature, habitat, and local shrimp density. We examined the relationships between shrimp survival and marsh attributes (amount of vegetation and edge habitat) by simulating a series of four habitat maps that we created from aerial photographs. Biological parameters were derived from published estimates and from field data. We corroborated the model by comparing the simulated shrimp abundance with summary statistics from long-term monitoring data, by comparing the simulated density with fine-scale patterns observed in field studies, and by comparing simulated and measured stable-isotope values. Surviving shrimp grew faster, moved less, spent more time in vegetation, and experienced slightly higher local densities than shrimp that died during the simulation. Habitat maps with more edge habitat invariably produced higher simulated shrimp survival rates. High-edge habitats increased survival by providing shrimp more direct access to vegetation without additional movement-related mortality and density-dependent growth costs associated with low-edge habitats. Model predictions were robust to higher numbers of initial postlarvae and to alterations to the movement rules. The results of this study suggest that the management of brown shrimp should be extended from protecting the spawning stock through catch regulations to also protecting the estuarine life stages through habitat conservation and restoration. C1 Louisiana State Univ, Dept Oceanog & Coastal Sci, Baton Rouge, LA 70803 USA. Louisiana State Univ, Coastal Fisheries Inst, Baton Rouge, LA 70803 USA. Louisiana State Univ, Coastal Ecol Inst, Baton Rouge, LA 70803 USA. Natl Marine Fisheries Serv, Fishery Ecol Branch, Galveston, TX 77551 USA. NOAA Fisheries, SE Fisheries Sci Ctr, Estuarine Habitats & Coastal Fisheries Ctr, Lafayette, LA 70506 USA. RP Haas, HL (reprint author), NE Fishery Sci Ctr, Protected Species Branch, 166 Water St, Woods Hole, MA 02543 USA. EM hhaas@mbl.edu NR 51 TC 36 Z9 36 U1 2 U2 17 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 2004 VL 14 IS 4 BP 1232 EP 1247 DI 10.1890/03-5101 PG 16 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 844KI UT WOS:000223156600023 ER PT J AU Guild, LS Kauffman, JB Cohen, WB Hlavka, CA Ward, DE AF Guild, LS Kauffman, JB Cohen, WB Hlavka, CA Ward, DE TI Modeling biomass burning emissions for amazon forest and pastures in Rondonia, Brazil SO ECOLOGICAL APPLICATIONS LA English DT Article DE Amazon; biomass burning; Brazil; carbon; land-cover change; land use; pasture; primary forest; regenerating forest; Rondonia; trace gas emissions ID NUTRIENT POOLS; TROPICAL DEFORESTATION; FIRE; CARBON; CONVERSION; CHEMISTRY; AEROSOLS; DYNAMICS; SAVANNA; FLUXES AB As a source of atmospheric carbon, biomass burning emissions associated with deforestation in the Amazon are globally significant. Once deforested, these lands continue to be sources of substantial burning emissions for many years due to frequent pasture burning. The objective of this research was to quantify biomass-burning emissions at a local scale. We estimated carbon emissions from three sources: fires associated with primary forest slash, regenerating forest slash, and pastures.-The study was conducted on a 94370-ha section of land surrounding Jamari, Rondonia, Brazil. In the emissions computation, we integrated site-specific, ground-based data (biomass, emission factors for flaming and smoldering combustion, and combustion factors for land-cover types) with a Landsat TM land cover change map of the study area for 1984-1992. This map was used to ascertain changes in land cover based on TM image dates during a period of early colonization and rapid deforestation in Rondonia. Emissions of CO, CO2, CH4, and other hydrocarbon trace gases were calculated. Between 1984 and 1992, we found CO, emissions generated by primary forest slash burning were 694379 Mg C (920 kg C(.)ha(-1.)yr(-1)) and regenerating forest slash burning contributed 23436 Mg C (31 kg C(.)ha(-1.)yr(-1)), whereas cumulative pasture burning produced 238 180 Mg C (316 kg C(.)ha(-1.)yr(-1)). CO and CH4 followed the same trends by land cover type. Primary forest slash burns contributed 73% of the total C emissions whereas burning regenerating forest slash and pasture. produced 2% and 25%, respectively. The major finding of this work is the identification of pasture burning as a potentially important source of pyrogenic emissions, but better data on biomass and combustion efficiency could confirm this finding. Further we demonstrated a novel method for estimating area burned that links land cover type and change to burn frequency. C1 NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. Oregon State Univ, Dept Wildlife & Fisheries, Corvallis, OR 97331 USA. Oregon State Univ, Dept Forest Sci, Corvallis, OR 97331 USA. Enviropyron, White Salmon, WA 98672 USA. RP Guild, LS (reprint author), NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, MS 242-2, Moffett Field, CA 94035 USA. EM lguild@gaia.arc.nasa.gov NR 46 TC 11 Z9 11 U1 0 U2 5 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 2004 VL 14 IS 4 SU S BP S232 EP S246 PG 15 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 845TU UT WOS:000223269000020 ER PT J AU Steininger, MK AF Steininger, MK TI Net carbon fluxes from forest clearance and regrowth in the Amazon SO ECOLOGICAL APPLICATIONS LA English DT Article DE biomass; Bolivia; Brazil; Landsat satellite; land use; regrowth; secondary forest ID TROPICAL DEFORESTATION; SECONDARY FORESTS; ABOVEGROUND BIOMASS; SATELLITE DATA; SUCCESSION; FRAGMENTATION; COLOMBIA; BOLIVIA; BRAZIL; AREA AB Estimates of net carbon exchange resulting from forest clearance and regrowth were made for three areas in the Brazilian and Bolivian Amazon. The study areas, ranging in size from 600 to 10 000 km(2) include communities that practice a range of land uses from small-scale, rotational agriculture to long-term pasture. Carbon emissions from deforestation were estimated based on rates of deforestation derived from Landsat satellite data and published estimates of mature forest biomass. Estimates of carbon uptake by secondary forest regrowth were based on area estimates from the satellite data and biomass estimates from field surveys. Estimates of carbon emissions from the clearance of secondary forest were included. The total carbon emissions were partitioned into that immediately released by biomass burning during clearance and that from subsequent decomposition and burning of felled biomass. A range of net carbon fluxes from secondary forest regrowth and clearance was estimated by extrapolating land-use patterns in each study area to the entire area of deforested landscape in Amazonian Brazil and Bolivia, and by varying average biomass accumulation rate of regrowing forest and fallow period. Over 60 km(2) of forest were cleared from 1988 to 1905 in each of the Brazilian study areas, and over 940 km(2) were cleared from 1986 to 1996 in the Bolivian study area. This resulted in 30-200 Mg C/yr emitted from biomass burning during deforestation. If the carbon that is committed to subsequent burning and decomposition of felled biomass is included, total committed emissions of 75-650 Mg C/yr resulted from deforestation in each study area. The carbon uptake by secondary forests was 33-435 Mg C/yr. However, emissions from the reclearance of secondary forests were nearly as large: 17-365 Mg C/yr. Extrapolation. of these results to the Brazilian and Bolivian Amazon suggests that, at the national level, carbon uptake by secondary forests offset less than one-fifth of the carbon emissions from deforestation. Despite differences in land-use pattern, average fallow period, and rate of biomass accumulation used in the extrapolation, net carbon uptake by secondary forests was consistently small when compared to the total emissions from deforestation. C1 NASA, Goddard Space Flight Ctr, Lab Terrestrial Phys, Greenbelt, MD 20771 USA. RP Steininger, MK (reprint author), NASA, Goddard Space Flight Ctr, Lab Terrestrial Phys, Code 923, Greenbelt, MD 20771 USA. EM marc@surutu.gsfc.nasa.gov NR 35 TC 8 Z9 9 U1 1 U2 6 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 2004 VL 14 IS 4 SU S BP S313 EP S322 PG 10 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 845TU UT WOS:000223269000025 ER PT J AU Kramer, MG Sollins, P Sletten, RS AF Kramer, MG Sollins, P Sletten, RS TI Soil carbon dynamics across a windthrow disturbance sequence in southeast Alaska SO ECOLOGY LA English DT Article DE (13)C solid-state NMR; humification; illuviation; lateral flow; mineral soil carbon; natural isotope abundance; podzolization; soil mixing; soil organic matter; temperate rain forest; tree uprooting; windthrow disturbance ID DISSOLVED ORGANIC-CARBON; SPODIC HORIZONS; NEW-ZEALAND; MATTER; FOREST; DECOMPOSITION; MECHANISMS; NITROGEN; PODZOLIZATION; ECOSYSTEMS AB Few studies have examined the influence of natural disturbances, such as windthrow, on soil organic matter formation, stabilization, and loss in soils. In shallow (< 1 m) mountain forest soils, windthrow activity may result in the redistribution and mixing of mineral and organic soil horizons down to bedrock. We studied the patterns of soil carbon, the dominant constituent of soil organic matter, in watersheds along a windthrow disturbance sequence in a mountainous temperate rain forest in southeast Alaska. Our objectives were (1) to evaluate the influence of windthrow and illuviation on the accumulation of soil organic carbon in mineral horizons and (2) to compare the forms of soil organic matter that have accumulated. Soils were described, and the thickness of the major organic and mineral horizons was measured, every 5 in along transects in three watersheds with contrasting windthrow histories. A subset of the soil description sites was randomly selected and then sampled to determine the quantity and quality of soil carbon. Mineral soil samples were physically fractionated based on particle density. Total carbon (C) and nitrogen (N), natural (15)N and (13)C abundance, micromorphologic analysis (using scanning electron microscopy), and solid-state (13)C nuclear magnetic resonance (NMR) were used to compare soil organic matter pools in the three watersheds. The Bh horizon heavy-fraction (>1.65 g/cml) C pools decreased from 25 Mg/ha in the least disturbed watershed to 3 Mg/ha in the most disturbed watershed; whereas light-fraction C pools were similar (4-6 Mg/ha) across all watersheds. Soil C stocks decreased from 216 Mg/ha in the least disturbed watershed to 157 Mg/ha in the most disturbed watersheds. Evidence was found that mobile organic carbon transported in soil water accumulated in mineral horizons principally through sorption to mineral particles. Strong association with mineral particles was greater in the thicker, presumably older, illuvial horizons. We found light amorphous material in some of these thicker illuvial horizons, suggesting that mobile organic carbon may have been immobilized through flocculation of metal-bearing organic acids. Watersheds that experienced more intense soil mixing from windthrow had lower levels of strongly humified soil organic matter, and more in a partially decomposed particulate form. C1 NASA, Ames Res Ctr, Div Earth Sci, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. Oregon State Univ, Dept Forest Sci, Corvallis, OR 97331 USA. Univ Washington, Quaternary Res Ctr Space Sci, Seattle, WA 98195 USA. RP Kramer, MG (reprint author), NASA, Ames Res Ctr, Div Earth Sci, Ecosyst Sci & Technol Branch, Mail Stop 242-4, Moffett Field, CA 94035 USA. NR 64 TC 28 Z9 30 U1 3 U2 22 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD AUG PY 2004 VL 85 IS 8 BP 2230 EP 2244 DI 10.1890/02-4098 PG 15 WC Ecology SC Environmental Sciences & Ecology GA 853JT UT WOS:000223824300018 ER PT J AU Brown, AM Seugling, RM AF Brown, AM Seugling, RM TI Using plate finite elements for modeling fillets in global response analysis SO FINITE ELEMENTS IN ANALYSIS AND DESIGN LA English DT Article DE fillets; thin-walled structures; dynamic analysis; structural analysis ID THICKNESS AB Fillets are one of the most common design features in structures. Proper finite element modeling of these fillets can frequently be problematic, though. Although the most appropriate element for modeling the structure in general may be the plate element, geometric and accurate stiffness representation of the fillets requires the use of a large number of numerically intensive solid elements. This problem is the motivation for the development of a method that uses "bridge" plate elements connecting the tangent points of the fillet to accurately represent its stiffness and mass. The methodology equates the rotational deflection at the tangent point, derived from the proposed bridge system, with an analytical solution for the fillet to generate a pseudo Young's modulus and thickness for use in the bridge plates. The method was tested on a typical filleted structure, with the bridge method yielding modal analysis results as accurate as a high-fidelity solid model when compared to modal test but with a 90% reduction in the number of degrees of freedom. Although the methodology has only been developed for perpendicular (90degrees) fillets, the approach shows promise for use in other fillet combinations as well. The application of this technique could prove extremely useful in design, dynamic and deflection analysis, stress analysis at locations away from the fillet, and optimization. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Struct Dynam & Loads Grp, Huntsville, AL 35812 USA. Natl Inst Stand, Mfg Metrol Div, Gaithersburg, MD 20899 USA. RP Brown, AM (reprint author), NASA, George C Marshall Space Flight Ctr, Struct Dynam & Loads Grp, ED21, Huntsville, AL 35812 USA. EM andrew.m.brown@nasa.gov NR 8 TC 1 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-874X J9 FINITE ELEM ANAL DES JI Finite Elem. Anal. Des. PD AUG PY 2004 VL 40 IS 13-14 BP 1963 EP 1975 DI 10.1016/j.finel.2004.01.008 PG 13 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA 843SY UT WOS:000223108000015 ER PT J AU Binzel, RP Rivkin, AS Stuart, JS Harris, AW Bus, SJ Burbine, TH AF Binzel, RP Rivkin, AS Stuart, JS Harris, AW Bus, SJ Burbine, TH TI Observed spectral properties of near-Earth objects: results for population distribution, source regions, and space weathering processes SO ICARUS LA English DT Article DE asteroids; asteroids composition; surfaces asteroids; asteroids near-earth ID ASTEROID SPECTROSCOPIC SURVEY; EXTINCT COMET CANDIDATES; S-TYPE ASTEROIDS; APPROACHING ASTEROIDS; ACHONDRITE METEORITES; ORDINARY CHONDRITES; PARENT BODY; PHASE-II; BELT; EVOLUTION AB We present new visible and near-infrared spectroscopic measurements for 252 near-Earth (NEO) and Mars-crossing (MC) objects observed from 1994 through 2002 as a complement to the Small Main-Belt Asteroid Spectroscopic Survey (SMASS, http://smass.mit.edu/). Combined with previously published SMASS results, we have an internally consistent data set of more than 400 of these objects for investigating trends related to size, orbits, and dynamical history. These data also provide the basis for producing a bias-corrected estimate for the total NEO population (Stuart and Binzel, 2004, Icarus 170, 295-311). We find 25 of the 26 Bus (1999, PhD thesis) taxonomic types are represented, with nearly 90% of the objects falling within the broad S-, Q-, X-, and C-complexes. Rare A- and E-types are more common in the MC than NEO population (about 5% compared to < 1%) and may be direct evidence of slow diffusion into MC orbits from the Flora and Hungaria regions, respectively. A possible family of MC objects (C-types) may reside at the edge of the 5:2 jovian resonance. Distinct signatures are revealed for the relative contributions of different taxonomic types to the NEO population through different source regions. E-types show an origin signature from the inner belt, C-types from the mid to outer belt, and P-types from the outer belt. S- and Q-types have effectively identical main-belt source region profiles, as would be expected if they have related origins. A lack of V-types among Mars-crossers suggests entry into NEO space via rapid transport through the v6 and 3:1 resonances from low eccentricity main-belt orbits, consistent with a Vesta origin. D-types show the strongest signature from Jupiter family cornets (JFC), with a strong JFC component also seen among the X-types. A distinct taxonomic difference is found with respect to the jovian Tisserand parameter T, where C-, D-, and X-type (most likely low albedo P-class) objects predominate for T less than or equal to 3. These objects, which may be extinct comets, comprise 4% of our observed sample, but their low albedos makes this magnitude limited fraction under-representative of the true value. With our taxonomy statistics providing a strong component to the diameter limited bias correction analysis of Stuart (2003, PhD thesis), we estimate 10-18% of the NEO population above any given diameter may be extinct comets, taking into account asteroids scattered into T < 3 orbits and comets scattered into T > 3 orbits. In terms of possible space weathering effects, we see a size-dependent transition from ordinary chondrite-like (Q-type) objects to S-type asteroids over the size range of 0.1 to 5 km, where the transition is effectively complete at 5 km. A match between the average surface age of 5 km asteroids and the rate of space weathering could constrain models for both processes. However, space weathering may proceed at a very rapid rate compared with collisional timescales. In this case, the presence or absence of a regolith may be the determining factor for whether or not an object appears "space weathered." Thus 0.1 to 5 km appears to be a critical size range for understanding the processes, timescales, and conditions under which a regolith conducive to space weathering is generated, retained, and refreshed. (C) 2004 Elsevier Inc. All rights reserved. C1 MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Space Sci Inst, La Canada Flintridge, CA 91011 USA. Inst Astron, Hilo, HI 96720 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Binzel, RP (reprint author), MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. EM rpb@init.edu RI Rivkin, Andrew/B-7744-2016 OI Rivkin, Andrew/0000-0002-9939-9976 NR 71 TC 172 Z9 172 U1 1 U2 4 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD AUG PY 2004 VL 170 IS 2 BP 259 EP 294 DI 10.1016/j.icarcus.2004.04.004 PG 36 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840EH UT WOS:000222839400001 ER PT J AU Banfield, D Conrath, BJ Gierasch, PJ Wilson, RJ Smith, MD AF Banfield, D Conrath, BJ Gierasch, PJ Wilson, RJ Smith, MD TI Traveling waves in the Martian atmosphere from MGS TES Nadir data SO ICARUS LA English DT Article DE atmospheres; dynamics; atmospheres; structure; Mars; atmosphere; meteorology ID GENERAL-CIRCULATION MODEL; MID-LATITUDE DISTURBANCES; NORTH POLAR HOOD; BAROCLINIC INSTABILITY; MARS; METEOROLOGY; DYNAMICS; SURFACE; EDDIES; VENUS AB We have characterized the annual behavior of martian atmospheric traveling waves in the MGS TES data set from the first two martian years of mapping. There is a high degree of repeatability between the two years. They are dominated by strong low zonal wavenumber waves with high amplitudes near the polar jets, strongest in late northern fall and early northern winter. The m = 1 waves have amplitudes up to about 20 K, are vertically extended, and occasionally extend even into the tropics. Periods for m = 1 range from 2.5 to 30 sols. Much weaker waves were identified in the south, with amplitudes less than about 3.5 K. Traveling waves with m = 2 and m = 3 are also seen, but their amplitudes are typically limited to less than 4 K, and are generally more confined near the surface. In the north, they are more evident in fall and spring rather than winter solstice, which is clearly dominated by m = I waves. Some evidence of storm tracks has been identified in the data, with accentuated weather-related temperature perturbations near longitudes 200degrees to 320degrees E for both the southern and northern hemispheres near latitude 650 at the surface. Some evidence was also found for a sharpening of longitudinal gradients into what may be frontal systems. EP flux divergences show the waves extracting energy from the zonal mean winds. When the m = 1 waves were strongest, decelerations of the zonal jet of order 30 m/(s sol) were measured. Above I scale height, the waves extract energy from the jet predominately through barotropic processes, but their character is overall mixed barotropic/baroclinic. Inertial instabilities may exist at altitude on the equatorward flanks of the polar jets, and marginal stability extends through to the tropics. This may explain the coordination of the tropical behavior of the waves with that centered along the polar jet, consistent with the ideas expressed in Wilson et al. (2002, Geophys. Res. Lett. 29, #1684) and similar to those in Barnes et al. (1993, J. Geophys. Res. 98, 3125-3148). Throughout the year, there exist large regions with the meridional gradient of PV less than zero, but they are strongest near winter solstice. Poleward of the winter jet, the regions of instability reach the surface, equatorward they do not. These regions, satisfying a necessary criterion for instability, likely explain the genesis of the waves, and perhaps also their bimodal character between surface (faster waves) and altitude (slow m = 1 waves). (C) 2004 Elsevier Inc. All rights reserved. C1 Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. EM banfield@astro.cornell.edu RI Smith, Michael/C-8875-2012; OI Banfield, Don/0000-0003-2664-0164 NR 34 TC 62 Z9 62 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 EI 1090-2643 J9 ICARUS JI Icarus PD AUG PY 2004 VL 170 IS 2 BP 365 EP 403 DI 10.1016/j.icarus.2004.03.015 PG 39 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840EH UT WOS:000222839400006 ER PT J AU Bullock, MA Moore, JM Mellon, MT AF Bullock, MA Moore, JM Mellon, MT TI Laboratory simulations of Mars aqueous geochemistry SO ICARUS LA English DT Article DE Mars; surface; mineralogy; regoliths ID PATHFINDER LANDING SITE; MARTIAN METEORITE; CHEMICAL-COMPOSITION; SNC METEORITES; CARBONATES; MODEL; SOIL; SURFACE; ORIGIN; WATER AB We report on laboratory experiments in which we allowed an SNC-derived mineral mix to react with pure water under a simulated Mars atmosphere for 7 months. These experiments were performed at one bar and at three different temperatures in order to simulate the subsurface conditions that most likely exist where liquid water and rock interact on Mars today. The dominant cations dissolved in the solutions we produced, which may be characterized as dilute brines, are Ca2+, Mg2+, Al3+, and Na+, while the major anions are dissolved C, F-, SO42- and Cl-. Typical solution pH was in the range of 4.2-6.0. Abundance patterns of elements in our synthetic sulfate-chloride brines are distinctly unlike those of terrestrial ocean water or continental waters, however, they are quite similar to those measured in the martian fines at the Mars Pathfinder and Viking 1 and 2 Landing sites. This suggests that salts present in the martian regolith may have formed over time as a result of the interaction of surface or subsurface liquid water with basalts in the presence of a martian atmosphere similar in composition to that of today. If most of the mobile surface layer was formed during the Noachian when erosion rates were much higher than at present, and if this layer is homogeneous in salt composition, the total amount of salt in the martian fines is approximately the same as in the Earth's oceans. The minimum quantity of circulating water necessary to deposit this amount of salt is approximately equivalent to a global layer 625 in deep. (C) 2004 Elsevier Inc. All rights reserved. C1 SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. RP SW Res Inst, Dept Space Studies, 1050 Walnut St,Suite 426, Boulder, CO 80302 USA. EM bullock@boulder.swri.edu RI Mellon, Michael/C-3456-2016 NR 55 TC 25 Z9 25 U1 0 U2 12 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 AUG PY 2004 VL 170 IS 2 BP 404 EP 423 DI 10.1016/j.icarus.2004.03.016 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840EH UT WOS:000222839400007 ER PT J AU Rannou, P Hourdin, F McKay, CP Luz, D AF Rannou, P Hourdin, F McKay, CP Luz, D TI A coupled dynamics-microphysics model of Titan's atmosphere SO ICARUS LA English DT Article DE Titan; haze; dynamics; photometry ID HUBBLE-SPACE-TELESCOPE; GENERAL-CIRCULATION; LATITUDINAL TRANSPORT; SEASONAL-VARIATIONS; BAROTROPIC WAVES; SURFACE PRESSURE; ADAPTIVE OPTICS; STRATOSPHERE; TEMPERATURE; SCATTERING AB We have developed a coupled general circulation model of Titan's atmosphere in which the aerosol haze is treated with a microphysical model and is advected by the winds. The radiative transfer accounts for the non uniform haze distribution and, in turn, drives the dynamics. We analyze the GCM results, especially focusing on the difference between a uniform haze layer and a haze layer coupled to the dynamics. In the coupled simulation the aerosols tend to accumulate at the poles, at latitudes higher than +/-60degrees. During winter, aerosols strongly radiate at thermal infrared wavelengths enhancing the cooling rate near the pole. Since this tends to increase the latitudinal gradients of temperature the direct effect of this cooling excess, in contrast to the uncoupled haze case, is to increase the strength of the meridional cells as well as the strength of the zonal winds and profile. This is a positive feedback of the haze on dynamics. The coupled model reproduces observations about the state of the atmosphere better than the uniform haze model, and in addition, the northern polar hood and the detached haze are qualitatively reproduced. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Versailles St Quentin, Serv Aeron, F-91370 Verrieres Le Buisson, France. Univ Paris 06, Meteorol Dynam Lab, F-75252 Paris 05, France. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Observ Meudon, LESIA, F-92195 Meudon, France. RP Rannou, P (reprint author), Univ Versailles St Quentin, Serv Aeron, BP 3, F-91370 Verrieres Le Buisson, France. EM pra@aero.jussieu.fr RI RANNOU, Pascal/I-9059-2012; Luz, David/J-4588-2013 OI Luz, David/0000-0002-9473-8035 NR 49 TC 83 Z9 83 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 AUG PY 2004 VL 170 IS 2 BP 443 EP 462 DI 10.1016/j.icarus.2004.03.007 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840EH UT WOS:000222839400010 ER PT J AU Matese, JJ Lissauer, JJ AF Matese, JJ Lissauer, JJ TI Perihelion evolution of observed new comets implies the dominance of the galactic tide in making Oort cloud comets discernable SO ICARUS LA English DT Article DE comets; dynamics; celestial mechanics ID MATTER AB For an Oort cloud comet to be seen as a new comet, its perihelion must be moved from a point exterior to the loss cylinder boundary to a point interior to observable limits in a single orbit. The galactic tide can do this continuously, in a non-impulsive manner. Near-parabolic comets, with specific angular momentum H proportional to rootq, will most easily be made observable. Therefore, to reduce the perihelion distance H must decrease. Since weakly perturbed cornets are, in general, more numerous than strongly perturbed comets, we can anticipate that new comets made observable by a weak tidal torque will more likely be first observed when their slowly changing perihelion distances are approaching their minimum osculating values under the action of the tide, rather than receding from their minimum values. That is, defining DeltaH(tide) as the vector change due to the galactic tidal torque during the prior orbit, and Hobs as the observed vector, the sign S equivalent to Sign(H-obs - DeltaH(tide)) will more likely be -1 than +1 if a weak galactic tidal perturbation indeed dominates in making comets observable. Using comet data of the highest quality class (I A) for new comets (a > 10, 000 AU), we find that 49 comets have S = - I and 22 have S = + 1. The binomial probability that as many or more would exhibit this characteristic if in fact S = -/+ I were equally likely is only 0.0009. This characteristic also persists in other long-period comet populations, lending support to the notion that they are dominated by comets recently arrived from the outer Oort cloud. The preponderance of S = -I also correlates with weakly perturbed (i.e., smaller semimajor axis) new comets in a statistically significant manner. This is strong evidence that the data are of sufficiently high quality and sufficiently free of observational selection effects to detect this unique imprint of the tide. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Louisiana, Dept Phys, Lafayette, LA 70504 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Matese, JJ (reprint author), Univ Louisiana, Dept Phys, Lafayette, LA 70504 USA. EM matese@louisiana.edu NR 19 TC 9 Z9 9 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 AUG PY 2004 VL 170 IS 2 BP 508 EP 513 DI 10.1016/j.icarus.2004.03.019 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840EH UT WOS:000222839400013 ER PT J AU Whittle, J Araujo, J AF Whittle, J Araujo, J TI Scenario modelling with aspects SO IEE PROCEEDINGS-SOFTWARE LA English DT Article AB There has been significant recent interest, within the aspect-oriented software development (AOSD) community, in representing crosscutting concerns at various stages of the software lifecycle. However, most of these efforts have concentrated on the design and implementation phases. The focus of this paper is on representing aspects during requirements modelling. In particular, the issue of how to model aspects as part of scenario-based modelling is addressed. The use of scenarios is common in requirements development and analysis. The authors describe how to represent and compose aspects at the scenario level. Aspectual scenarios are modelled as interaction pattern specifications (IPSs) and are composed with nonaspectual scenarios using instantiation and special composition operators. The composed collection of scenarios can then be translated automatically into a set of state machines using an existing state machine synthesis algorithm. The resulting set of state machines is an executable form of the scenarios and can be used for simulation and analysis of the requirements. C1 NASA, QSS Grp Inc, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Nova Lisboa, Fac Ciencias & Tecnol, Dept Informat, P-2829516 Caparica, Portugal. RP NASA, QSS Grp Inc, Ames Res Ctr, M-S 269-2, Moffett Field, CA 94035 USA. RI Araujo, Joao/G-2108-2011; FCTUNL, CITI/G-6714-2011; Araujo, Joao/M-3560-2013 OI Araujo, Joao/0000-0001-5914-1631 NR 36 TC 47 Z9 49 U1 0 U2 0 PU INST ENGINEERING TECHNOLOGY-IET PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 1462-5970 J9 IEE P-SOFTW JI IEE Proc-Softw PD AUG PY 2004 VL 151 IS 4 BP 157 EP 171 DI 10.1049/ip-sen:20040921 PG 15 WC Computer Science, Software Engineering SC Computer Science GA 875SL UT WOS:000225441900002 ER PT J AU de Oliveira, JC Scoglio, C Akyildiz, IF Uhl, G AF de Oliveira, JC Scoglio, C Akyildiz, IF Uhl, G TI New preemption policies for DiffServ-aware traffic engineering to minimize rerouting in MPLS networks SO IEEE-ACM TRANSACTIONS ON NETWORKING LA English DT Article; Proceedings Paper CT IEEE INFOCOM 2002 Meeting CY JUN 23-27, 2002 CL NEW YORK, NY SP IEEE DE DiffServ; MPLS networks; preemption; traffic engineering (TE) AB The preemption policy currently in use in MPLS-enabled commercial routers selects LSPs for preemption based only on their priority and holding time. This can lead to waste of resources and excessive number of rerouting decisions. In this paper, a new preemption policy is proposed and complemented with an adaptive scheme that aims to minimize rerouting. The new policy combines the three main preemption optimization criteria: number of LSPs to be preempted, priority of the LSPs, and preempted bandwidth. Weights can be configured to stress the desired criteria. The new policy is complemented by an adaptive scheme that selects lower priority LSPs that can afford to have their rate reduced. T he selected LSPs will fairly reduce their rate in order to accommodate the new high-priority LSP setup request. Performance comparisons of a nonpreemptive approach, a policy currently in use by commercial routers, and our policies are also investigated. C1 Drexel Univ, Dept Elect & Comp Engn, Philadelphia, PA 19104 USA. Georgia Inst Technol, Sch Elect & Comp Engn, Broadband & Wireless Networking Lab, Atlanta, GA 30332 USA. Swales Aerosp, Beltsville, MD 20705 USA. NASA, Goddard Space Flight Ctr, Beltsville, MD 20705 USA. RP de Oliveira, JC (reprint author), Drexel Univ, Dept Elect & Comp Engn, Philadelphia, PA 19104 USA. EM jau@ece.drexel.edu; caterma@ece.gatech.edu; ian@ee.gatech.edu; uhl@rattler.gsfc.nasa.gov RI Akyildiz, Ian/G-7136-2011 OI Akyildiz, Ian/0000-0002-8099-3529 NR 19 TC 21 Z9 21 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1063-6692 EI 1558-2566 J9 IEEE ACM T NETWORK JI IEEE-ACM Trans. Netw. PD AUG PY 2004 VL 12 IS 4 BP 733 EP 745 DI 10.1109/TNET.2004.833156 PG 13 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 851NB UT WOS:000223690700014 ER PT J AU Pogorzelski, RJ AF Pogorzelski, RJ TI Phased arrays based on oscillators coupled on triangular and hexagonal lattices (vol 52, pg 790, 2004) SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Correction C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Pogorzelski, RJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM pogp@jpl.nasa.gov NR 1 TC 1 Z9 1 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD AUG PY 2004 VL 52 IS 8 BP 2196 EP 2196 DI 10.1109/TAP.2004.832315 PG 1 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 846EV UT WOS:000223299000037 ER PT J AU Freeman, A Saatchi, SS AF Freeman, A Saatchi, SS TI On the detection of faraday rotation in linearly polarized L-band SAR backscatter signatures SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE Faraday rotation; polarimetry; synthetic aperture radar (SAR) ID FOREST BIOMASS; PROPAGATION AB The potentially measurable effects of Faraday rotation on linearly polarized backscatter measurements from space are addressed. Single-polarized, dual-polarized, and quad-polarized backscatter measurements subject to Faraday rotation are first modeled. Then, the impacts are assessed using L-band polarimetric synthetic aperture radar (SAR) data. Due to Faraday rotation, the received signal will include other polarization characteristics of the surface, which may be detectable under certain conditions. Model results are used to suggest data characteristics that will reveal the presence of Faraday rotation in a given single-polarized, dual-polarized, or quad-polarized L-band SAR dataset, provided the user can identify scatterers within the scene whose general behavior is known or can compare the data to another, similar dataset with zero Faraday rotation. The data characteristics found to be most sensitive to a small amount of Faraday rotation (i.e., a one-way rotation < 20degrees) are the cross-pol backscatter [sigmadegrees(HV)] and the like-to-cross-pol correlation [e.g., p(HHHV*)]. For a diverse, but representative, set of natural terrain, the level of distortion across a range of backscatter measures is shown to be acceptable (i.e., minimal) for one-way Faraday rotations of less than 5degrees, and 3degrees if the radiometric uncertainty in the HV backscatter is specified to be less than 0.5 dB. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Freeman, A (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. NR 23 TC 57 Z9 67 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 AUG PY 2004 VL 42 IS 8 BP 1607 EP 1616 DI 10.1109/TGRS.2004.830163 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 846DW UT WOS:000223296300001 ER PT J AU Freeman, A AF Freeman, A TI Calibration of linearly polarized polarimetric SAR data subject.to faraday rotation SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE calibration; Faraday rotation; polarimetry; synthetic aperture radar (SAR) ID FOREST BIOMASS; SCATTERING MATRIX; PROPAGATION AB A model for linearly polarized fully polarimetric backscatter measurements is used, incorporating the effects of system noise, channel amplitude, phase imbalance, crosstalk, and Faraday rotation. A step-by-step procedure is outlined for correction (or calibration) of fully polarimetric data subject to Faraday rotation, to recover the true scattering matrix. The procedure identifies steps for crosstalk removal and correction of channel imbalances that are robust in the presence of Faraday rotation. The final steps in the procedure involve a novel strategy for estimation and correction of Faraday rotation. Three approaches to estimate the (one-way) Faraday rotation angle Omega directly from linear (quad-) polarized synthetic aperture radar (SAR) backscatter data obtained by a spaceborne SAR system are described. Each approach can initially be applied to the signature of any scatterer within the scene. Sensitivity analyses are presented that show that at least one of the measures can be used to estimate 0 to within +/-3degrees to 5degrees, with reasonable levels of residual crosstalk, noise floor, channel amplitude, and phase imbalance. Ambiguities may be present in the estimates of Omega of +/-npi/2-the impact of this is discussed, and several approaches are suggested to deal with this possibility. The approach described in this paper is relevant for future L- and spaceborne SARs and removes one key obstacle to the deployment of even longer wavelength SARs (e.g., an ultrahigh frequency or P-band SAR) in earth orbit. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Freeman, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 26 TC 76 Z9 89 U1 1 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD AUG PY 2004 VL 42 IS 8 BP 1617 EP 1624 DI 10.1109/TGRS.2004.830161 PG 8 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 846DW UT WOS:000223296300002 ER PT J AU Tang, WQ Liu, WT Stiles, BW AF Tang, WQ Liu, WT Stiles, BW TI Evaluations of high-resolution ocean surface vector winds measured by QuikSCAT scatterometer in coastal regions SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE coastal ocean; scatterometer; vector wind ID ACCURACY AB The SeaWinds scatterometer onboard QuikSCAT covers approximately 90% of the global ocean tinder clear and cloudy condition in 24 h, and the standard data product has 25-km spatial resolution. Such spatial resolution is not sufficient to resolve small-scale processes, especially in coastal oceans. Based on range-compressed normalized backscatter and a modified wind retrieval algorithm, a coastal wind dataset at 12.5-km resolution was produced. Even with larger error, the high-resolution winds, in medium to high strength, would still be useful over coastal ocean. Using measurements from moored buoys from the National Buoy Data Center, the high-resolution QuikSCAT wind data are found to have similar accuracy as standard data in the open ocean. The accuracy of both high- and standard -resolution winds, particularly in wind directions, is found to degrade near shore. The increase in error is likely caused by the inadequacy of the geophysical model function/ambiguity removal scheme in addressing coastal conditions and light winds situations. The modified algorithm helps to bring the directional accuracy of the high-resolution winds to the accuracy of the standard-resolution winds in near-shore regions, particularly in the nadir and far zones across the satellite track. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tang, WQ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Wenqing.Tang@jpl.nasa.gov NR 16 TC 42 Z9 45 U1 0 U2 3 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 AUG PY 2004 VL 42 IS 8 BP 1762 EP 1769 DI 10.1109/TGRS.2004.831685 PG 8 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 846DW UT WOS:000223296300017 ER PT J AU Ersmark, T Carlson, P Daly, E Fuglesang, C Gudowska, I Lund-Jensen, B Nartallo, R Nieminen, P Pearce, M Santin, G Sobolevsky, N AF Ersmark, T Carlson, P Daly, E Fuglesang, C Gudowska, I Lund-Jensen, B Nartallo, R Nieminen, P Pearce, M Santin, G Sobolevsky, N TI Status of the DESIRE project: Geant4 physics validation studies and first results from columbus/ISS radiation simulations SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference/13th International Workshop on Room-Temperature Semiconductor X-and Gamma-Ray Dectectors/Symposium on Nuclear Power Systems CY OCT 19-25, 2003 CL Portland, OR SP IEEE DE biological effects of radiation; Monte Carlo methods; radiation effects; simulation software; space stations ID STOPPING-LENGTH TARGETS; NEUTRON YIELDS; CODE; TRANSPORT; PROTONS; SHIELD AB The Dose Estimation by Simulation of the ISS Radiation Environment (DESIRE) project aims to accurately calculate radiation fluxes and doses to astronauts inside the European Columbus module of the International Space Station using Geant4. Since Geant4 has not been previously used for this type of application it needs to be validated. This will be followed by a detailed evaluation of the incident radiation fields on ISS and culminate with the geometry modeling and full-scale flux and dose simulations for Columbus. Geant4 validation studies and comparisons to other tools are presented. These concern the angle and energy distributions of particles leaving irradiated targets and of energy depositions in the targets. Comparisons are made between simulations using different Geant4 physics models, experimental data, and other particle transport programs. Geant4 using the "Binary Cascade" model for inelastic nucleon reactions performs very well in these comparisons, but some issues with other models remain to be resolved if they are to be used for space radiation shielding applications. Results of Geant4 simulations of the transport of some relevant radiation field components through the hull of a simplified model of Columbus are also presented. C1 Royal Inst Technol, Sect Particle Phys, SE-10691 Stockholm, Sweden. ESTEC, ESA, TOS, EES,Space Environments & Effects Sect, NL-2200 AG Noordwijk, Netherlands. ESA Astronaut Ctr, D-51147 Cologne, Germany. NASA, JSC, Houston, TX 77058 USA. Karolinska Inst, Div Med Radiat Phys, S-17176 Stockholm, Sweden. Russian Acad Sci, Nucl Res Inst, Dept Neutron Res, Moscow 117312, Russia. RP Ersmark, T (reprint author), Royal Inst Technol, Sect Particle Phys, SE-10691 Stockholm, Sweden. NR 22 TC 16 Z9 16 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 2004 VL 51 IS 4 BP 1378 EP 1384 DI 10.1109/TNS.2004.832648 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 847KP UT WOS:000223391600013 ER PT J AU Fry, CD Dryer, M Sun, W Delman, TR Smith, ZK Deehr, CS Wu, CC Akasofu, S Berdichevsky, DB AF Fry, CD Dryer, M Sun, W Delman, TR Smith, ZK Deehr, CS Wu, CC Akasofu, S Berdichevsky, DB TI Solar observation-based model for a multiday predictions of interplanetary shock and CME arrivals at earth SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT NATO Advanced Research Workshop on Effects of Space Weather on Technology Infrastructure CY MAR, 2003 CL Rhodes, GREECE SP NATO DE plasmas; shock waves; space technology ID REAL-TIME; SKILL AB We present the design, implementation, present status, and preliminary use of an operational forecaster-friendly solar wind prediction system. We have tested this architecture in our real-time "fearless forecast" 'prediction study of interplanetary shock arrival time (SAT) at Earth. This study has progressed on a continuous basis since 1997, near the rise of Solar Cycle 23. Comparisons of predicted SAT with observed SAT provide a measure of model forecast skill. We present our kinematic model's forecast skill statistics as compared with several other SAT models and propose important reference metrics for evaluating this and any other interplanetary modeling system. Our prediction system is presently being extended, via a hybrid approach, to include a three-dimensional magnetohydrodynamic (MHD) model. This procedure will accommodate proxy inputs for simulating interplanetary disturbances that are associated with various forms of solar activity (flares, disappearing filaments, coronal mass ejection imagery, shocks). The objective is to provide a capability in the near term to predict, shortly after the launch of large-scale structures at the Sun, the time-dependent interplanetary magnetic field vector (including the north-south component, Bz) at Earth. This is a key requirement for predicting geomagnetic storms. C1 Explorat Phys Int Inc, Huntsville, AL 35806 USA. Natl Ocean & Atmospher Adm, Space Environm Ctr, Boulder, CO 80305 USA. Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. Univ Alabama, Ctr Space Plasmas & Aeronom Res, Huntsville, AL 35806 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20711 USA. L3 Govt Serv Inc, Largo, MD 20774 USA. RP Explorat Phys Int Inc, Huntsville, AL 35806 USA. EM gfry@expi.com; murray.dryer@noaa.gov; sun@jupiter.gi.alaska.edu; cdeehr@gi.alaska.edu; zdenka.smith@noaa.gov; wuc@cspar.uah.edu; sakasofu@iarc.uaf.edu; berdi@berdi.gsfc.nasa.gov RI xue, yansheng/A-9712-2012 NR 22 TC 15 Z9 15 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 EI 1939-9375 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 2004 VL 32 IS 4 BP 1489 EP 1497 DI 10.1109/TPS.2004.833398 PN 1 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 863EV UT WOS:000224544600012 ER PT J AU Smith, ZK Detman, TR Dryer, M Fry, CD Wu, CC Sun, W Deehr, CS AF Smith, ZK Detman, TR Dryer, M Fry, CD Wu, CC Sun, W Deehr, CS TI A verification method for space weather forecasting models using solar data to predict arrivals of interplanetary shocks at earth SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT NATO Advanced Research Workshop on Effects of Space Weather on Technology Infrastructure CY MAR, 2003 CL Rhodes, GREECE SP NATO DE space technology; space weather; verification ID CORONAL MASS EJECTIONS; TIMES AB The ability to predict the arrival of interplanetary shocks near earth is of great interest in space Weather because of their relationship to sudden impulses and geomagnetic storms. A number of models have been developed for this purpose. For models to be used in forecasting, it is important to provide verification in the operational environment using standard statistical techniques because this enables the intercomparison of different models. A verification method is described here, comparing the prediction capabilities of four models that use solar observations for input. Three of the models are based on metric Type II radio burst observations, and one uses halo/partial-halo coronal mass ejections. A method of associating solar events with interplanetary shocks is described. The predictions are compared to associated shocks observed at L1 by the Advanced Composition Explorer (ACE) spacecraft. The time period of this study is January 2002-May 2002. Although the data sample is small, the statistical intercomparison of the results of these models is presented as a demonstration of the verification method. C1 NOAA, Space Environm Ctr, Boulder, CO 80305 USA. Explorat Phys Int Inc, Huntsville, AL 35806 USA. Univ Alabama, CSPAR, Huntsville, AL 35899 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. RP NOAA, Space Environm Ctr, Boulder, CO 80305 USA. EM zdenka.smith@noaa.gov; thomas.detman@noaa.gov; murray.dryer@noaa.gov; gfry@expi.com; ccwu@lepccwu.gsfc.nasa.gov; sun@jupiter.gi.alaska.edu; cdeehr@gi.alaska.edu RI xue, yansheng/A-9712-2012 NR 15 TC 20 Z9 20 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 EI 1939-9375 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 2004 VL 32 IS 4 BP 1498 EP 1505 DI 10.1109/TPS.2004.832509 PN 1 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 863EV UT WOS:000224544600013 ER PT J AU Weigel, RS Baker, DN Rigler, EJ Vassiliadis, D AF Weigel, RS Baker, DN Rigler, EJ Vassiliadis, D TI Predictability of large geomagnetic disturbances based on solar wind conditions SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT NATO Advanced Research Workshop on Effects of Space Weather on Technology Infrastructure CY MAR, 2003 CL Rhodes, GREECE SP NATO DE decision-making; geomagnetism; geophysical measurements; geophysical signal processing; prediction methods ID FORECASTS AB We test the ability of a data-derived model of geomagnetic activity, originally optimized to have a high prediction efficiency (PE), for its ability to predict only large geomagnetic disturbances. Correlation-based metrics, such as prediction efficiency, are often used as a measure of model performance. This metric puts equal weight on prediction of both large and small measurements. However, for space weather purposes, one is often interested in knowing only if a large disturbance event will occur so less emphasis should be placed on small measurements. If only large events are of interest, then a correlation metric is not the best measure of model performance. In this work, we determine how well a data-derived model, originally optimized to have a high prediction efficiency, predicts large geornagnetic events. The ratio of the number of correct to false alarm forecasts, R-F, is used as, an. event-predictor metric. It is shown that in the electrojet regions the data-derived model that predicts the north-south component of the ground magnetic field B-x has a spatial RF profile similar to that of the prediction efficiency. Maximal values of R-F = 4 are found at 0300 MLT when an event is defined as an excursion in the hourly-averaged north south component of the ground magnetic field below -400 nT. Whereas the local time profile of PE(B-x) is similar to R-F(B-x), the profile of PE(\dB(x)/dt\) differs substantially from R-F(\dB(x)/dt\) in the noon sector. Epoch analysis shows that the poor performance in the noon sector is a result of pre-event levels of \dB(x)/dt\ not being clearly separated from post-event levels. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80301 USA. Univ Res Corp, NASA, Goddard Space Flight Ctr, Lanham, MD 20706 USA. RP Weigel, RS (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80301 USA. EM robert.weigel@lasp.colorado.edu; jrigier@colorado.edu; vassi@electra.gsfc.nasa.gov NR 8 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 2004 VL 32 IS 4 BP 1506 EP 1510 DI 10.1109/TPS.2004.830992 PN 1 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 863EV UT WOS:000224544600014 ER PT J AU Singer, BA Guo, YP AF Singer, BA Guo, YP TI Development of computational aeroacoustics tools for airframe noise calculations SO INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS LA English DT Article DE computational aeroacoustics; wave dispersion and dissipation; airframe noise; community noise; noise propagation ID FINITE-DIFFERENCE SCHEMES; JET MIXING NOISE; TRAILING-EDGE; BOUNDARY-CONDITIONS; ACOUSTIC ANALOGY; TURBULENCE; FLOW; SIMULATIONS; SLAT; LAYER AB This paper discusses the development of computational aeroacoustics (CAA) tools for airframe noise analysis and prediction. We review recent progress in this topic, but emphasize our vision for the future development of such tools. Our intention is for this vision to drive future CAA research in directions that will accelerate widespread use of CAA for airframe noise applications. We discuss the needs for accuracy, efficiency, and easy interface with other design tools and illustrate how CAA tools may help future aircraft design. We explain what appears to be achievable in a 20-year time frame, and what goals will probably take longer. Important barrier issues include the effects of numerical dispersion and dissipation, the treatment of highly curved, irregular boundary surfaces, and grid generation. Beyond these largely numerical issues, we discuss the role of physics-based modeling, including turbulence modeling in unsteady flow computations and the importance of developing sophisticated techniques for analyzing results of computations. Numerical simulations combined with the acoustic analogy methodology to predict noise are also reviewed. Finally, we discuss how to use recent advances in measurement techniques for CAA tool validation, which is an integral part of future development. C1 NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. Boeing Co, Huntington Beach, CA 92647 USA. RP Singer, BA (reprint author), NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, 18E W Taylor St,Mail Stop 128, Hampton, VA 23681 USA. EM bart.a.singer@nasa.gov; yueping.guo@boeing.com NR 75 TC 4 Z9 5 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1061-8562 EI 1029-0257 J9 INT J COMPUT FLUID D JI Int. J. Comput. Fluid Dyn. PD AUG PY 2004 VL 18 IS 6 BP 455 EP 469 DI 10.1080/10618560410001673470 PG 15 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 829XB UT WOS:000222083600002 ER PT J AU Envia, E Wilson, AG Huff, DL AF Envia, E Wilson, AG Huff, DL TI Fan noise: A challenge to CAA SO INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS LA English DT Article DE fan noise; computational aeroacoustics; broadband noise; rotor-stator interaction noise; multiple pure tones; self-noise ID ACOUSTIC RADIATION; FLOW; SIMULATION AB The objective of this paper is to expose the computational aeroacoustics (CAA) community to the current unresolved issues in modeling and predicting fan noise. The paper includes a description of the sources of fan noise and a discussion of the current status of the fan noise prediction methods and their shortcomings. The discussion is focused on the issues and includes sufficient details to help outline the scope of the fan noise problem and define the level of fidelity required for meaningful CAA simulations. C1 NASA, Glenn Res Ctr, Acoust Branch, Cleveland, OH 44135 USA. Rolls Royce PLC, Derby DE24 8BJ, England. NASA, Glenn Res Ctr, Struct & Acoust Div, Cleveland, OH 44135 USA. RP Envia, E (reprint author), NASA, Glenn Res Ctr, Acoust Branch, Mail Stop 54-3,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM edmane.envia-1@nasa.gov; alexander.g.wilson@rolls-royce.com; dennis.l.huff@nasa.gov NR 89 TC 18 Z9 19 U1 1 U2 8 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1061-8562 J9 INT J COMPUT FLUID D JI Int. J. Comput. Fluid Dyn. PD AUG PY 2004 VL 18 IS 6 BP 471 EP 480 DI 10.1080/10618560410001673489 PG 10 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 829XB UT WOS:000222083600003 ER PT J AU Parker, GG Harding, DJ Berger, ML AF Parker, GG Harding, DJ Berger, ML TI A portable LIDAR system for rapid determination of forest canopy structure SO JOURNAL OF APPLIED ECOLOGY LA English DT Article DE canopy height profile; complexity; laser rangefinder; metrics; spatial variation; visualization ID AIRBORNE LASER ALTIMETER; FOLIAGE-HEIGHT PROFILES; BROAD-LEAVED FORESTS; TREE HEIGHTS; SCANNER DATA; VEGETATION; DIVERSITY; ACCURACY; STANDS AB 1. The functional characteristics of forests are related to the organization of their canopies. However, understanding the relationship between canopy structure and function has been limited by a paucity of methods for determining structure at scales consistent with those of function measurements. 2. We describe here a portable system, assembled from commercially available components, for acquiring measurements of distances to overhead plant surfaces. These measurements can be aggregated to assess canopy structure rapidly at scales of ecological interest. Deployed from the forest floor, the system includes a narrow-beam rapidly pulsed first-return laser rangefinder coupled with a data recording system. 3. Tests in an age sequence of broad-leaved closed-canopy forests showed that the system provides results significantly more rapidly than previous methods, at spatial scales as small as 1 m in all dimensions. The estimated mean vertical canopy structure is consistent with that found from more laborious, manual approaches, such as the foliage height profile method. The system has some biases due to beam width and range averaging but, from a variety of tests, we found these have relatively little effect on the structure estimates. 4. Various field sampling schemes and methods of aggregating the measurements yield a variety of representations of structure, including mean profiles, tomographic sections, three-dimensional distributions of canopy surface density and maximum height surfaces. Derivable summary measures include canopy cover and area index, porosity, the size distribution of overhead openings and indices of structural complexity. Moreover, the approach can provide estimates of spatial variability and covariance not previously obtainable. 5. Synthesis and applications. Portable light detection and ranging (LIDAR) systems, such as the one we describe here, provide a new tool for rapid measurement of small-scale forest structure. These can contribute efficiently and relatively inexpensively to canopy research and forestry programmes, covering a range of ecological and production needs. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. NASA, Goddard Space Flight Ctr, Geodynam Branch, Greenbelt, MD 20771 USA. RP Parker, GG (reprint author), Smithsonian Environm Res Ctr, 647 Contees Wharf Rd, Edgewater, MD 21037 USA. EM parkerg@si.edu RI Harding, David/F-5913-2012; OI Parker, Geoffrey/0000-0001-7055-6491 NR 50 TC 94 Z9 97 U1 1 U2 29 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0021-8901 J9 J APPL ECOL JI J. Appl. Ecol. PD AUG PY 2004 VL 41 IS 4 BP 755 EP 767 DI 10.1111/j.0021-8901.2004.00925.x PG 13 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 838OB UT WOS:000222721600016 ER PT J AU Shige, S Takayabu, YN Tao, WK Johnson, DE AF Shige, S Takayabu, YN Tao, WK Johnson, DE TI Spectral retrieval of latent heating profiles from TRMM PR data. Part I: Development of a model-based algorithm SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID MADDEN-JULIAN OSCILLATION; LARGE-SCALE CIRCULATIONS; TROPICAL CLOUD CLUSTERS; MEASURING MISSION TRMM; TOGA COARE; VERTICAL PROFILES; MOISTURE BUDGETS; STRATIFORM PRECIPITATION; CONVECTING ATMOSPHERES; RESOLVING MODEL AB An algorithm, the spectral latent heating (SLH) algorithm, has been developed to estimate latent heating profiles for the Tropical Rainfall Measuring Mission precipitation radar with a cloud-resolving model (CRM). Heating-profile lookup tables for the three rain types-convective, shallow stratiform, and anvil rain ( deep stratiform with a melting level)-were produced with numerical simulations of tropical cloud systems in the Tropical Ocean and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment. For convective and shallow stratiform regions, the lookup table refers to the precipitation-top height (PTH). For the anvil region, on the other hand, the lookup table refers to the precipitation rate at the melting level instead of PTH. A consistency check of the SLH algorithm was also done with the CRM-simulated outputs. The first advantage of this algorithm is that differences of heating profiles between the shallow convective stage and the deep convective stage can be retrieved. This is a result of the utilization of observed information, not only on precipitation type and intensity, but also on the precipitation depth. The second advantage is that heating profiles in the decaying stage with no surface rain can also be retrieved. This comes from utilization of the precipitation rate at the melting level for anvil regions. C1 Japan Aerosp Explorat Agcy, Earth Observ Res & Applicat Ctr, Tokyo, Japan. Univ Tokyo, Ctr Climate Syst Res, Tokyo, Japan. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 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 76 TC 72 Z9 72 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 2004 VL 43 IS 8 BP 1095 EP 1113 DI 10.1175/1520-0450(2004)043<1095:SROLHP>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 847DW UT WOS:000223373900003 ER PT J AU Redder, CR Luers, JK Eskridge, RE AF Redder, CR Luers, JK Eskridge, RE TI Unexplained discontinuity in the US radiosonde temperature data. Part II: Stratosphere SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID COMPLEX QUALITY-CONTROL; ENVIRONMENTAL PREDICTION; VAISALA RADIOSONDES; DATA ASSIMILATION; NATIONAL CENTERS; ANALYSIS SYSTEM; TROPOSPHERE; HEIGHTS; VIZ AB The second part of this two-part article discusses the differences between observations taken at 0000 and 1200 UTC, particularly in the stratosphere, by the Vaisala RS80-57H radiosondes that are integrated within the National Weather Service's (NWS's) Micro-ART system. There are large maxima in the horizontal distributions of the monthly time means of the 0000/1200 UTC temperature and height differences over the central United States that are absent over Canada. These maxima are as large as 5 K and 150 m at 10 hPa. Data analysis shows that the 0000/1200 UTC differences are largely artificial, especially over the central United States. They originate in the postprocessing software at observing stations, thus confirming the findings in Part I. Special flight data from the NWS test facility at Sterling, Virginia, have been used to deduce the bias correction applied by Vaisala's postprocessing system. By analyzing the correction data, it has been shown that the inconsistencies with non-U.S. Vaisala RS80 data, as well as most of the large 0000/1200 UTC differences over the United States, can be accounted for by multiplying the reported time since radiosonde launch by a factor of 5/3, which is incorrectly applied by the Vaisala postprocessing software. After being presented with the findings in this paper, Vaisala further isolated the source of the inconsistencies to a software coding error in the radiation bias correction scheme. The error affects only the software installed at NWS stations. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Sci Applicat Int Corp, Beltsville, MD USA. Univ Dayton, Res Inst, Dayton, OH 45469 USA. Natl Climat Ctr, Asheville, NC USA. RP Redder, CR (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 900 3, Greenbelt, MD 20771 USA. EM credder@gmao.gsfc.nasa.gov NR 24 TC 10 Z9 10 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD AUG PY 2004 VL 21 IS 8 BP 1133 EP 1144 DI 10.1175/1520-0426(2004)021<1133:UDITUR>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 845DL UT WOS:000223215900001 ER PT J AU Nasiri, SL Baum, BA AF Nasiri, SL Baum, BA TI Daytime multilayered cloud detection using multispectral imager data SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID AIRBORNE SIMULATOR IMAGERY; MODIS; OVERLAP; RADAR; LIDAR AB This study reports on recent progress toward the daytime detection of multilayered clouds in satellite multispectral data, specifically for the case of optically thin cirrus overlying lower-level water clouds. The technique is applied to 200 x 200 pixel arrays of data from the Moderate Resolution Imaging Spectroradiometer ( MODIS) and is primarily based on the relationship between the near-infrared reflectance (at either 1.6 or 2.1 mum) and the 11-mum brightness temperature. Additional information used by the algorithm includes the operational MODIS cloud mask and cloud thermodynamic phase as inferred from the 8.5- and 11- m m brightness temperatures. The performance of the algorithm is evaluated for two MODIS case studies, and results are compared to coincident cloud physics lidar (CPL) data obtained from an aircraft platform. In both cases, the multilayered cloud detection algorithm results appear reasonable in comparison with the CPL data. The first case study, from 11 December 2002 during the Terra-Aqua Experiment (TX-2002), also examines the behavior of the algorithm when midlevel or mixed-phase cloud is present. The second case study, from 26 February 2003 during The Observing System Research and Predictability Experiment (THORPEX) campaign, sheds light on the sensitivity of the algorithm to optically thin cirrus. In this case, the algorithm does not detect cirrus with a visible (0.564 mum) optical thickness of less than 0.1 when it overlies a lower-level water cloud. C1 Univ Wisconsin, CIMSS, Madison, WI 53706 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Nasiri, SL (reprint author), Univ Wisconsin, CIMSS, 1225 W Dayton St, Madison, WI 53706 USA. EM shaima@ssec.wisc.edu RI Nasiri, Shaima/C-8044-2011; Baum, Bryan/B-7670-2011 OI Baum, Bryan/0000-0002-7193-2767 NR 14 TC 20 Z9 20 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD AUG PY 2004 VL 21 IS 8 BP 1145 EP 1155 DI 10.1175/1520-0426(2004)021<1145:DMCDUM>2.0.CO;2 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 845DL UT WOS:000223215900002 ER PT J AU Mitchum, GT Hancock, DW Hayne, GS Vandemark, DC AF Mitchum, GT Hancock, DW Hayne, GS Vandemark, DC TI Blooms of sigma(0) in the TOPEX radar altimeter data SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SURFACE; BACKSCATTER; SCATTEROMETER; SEA AB Data from satellite altimeters are often degraded by the occurrence of unrealistically high radar return cross sections, which indicate a breakdown of the rough surface scattering model used to interpret these measurements in terms of satellite to sea surface height ranges. The TOPEX altimetric data are examined and nearly 200 000 such events during the 7-yr period, 1993-99, inclusive, are identified. The primary purpose of this paper is to make a comprehensive description of where and when these events occur, which is important because many of the communities that make use of the TOPEX data are generally unaware of this phenomenon. It is shown that these events affect almost 6% of the over-ocean TOPEX data, but only approximately 60% of these events are rejected by the recommended TOPEX data flagging. A global description of these events is made, showing that the events are associated with regions of climatologically weak winds ( e. g., the summer hemispheres and the western Pacific warm pool region), supporting the existing hypothesis that these events are due to returns from surfaces where centimeter-scale waves are suppressed. The TOPEX results are confirmed with a comparison to anomalous returns from the NASA Scatterometer (NSCAT), and the relationship to very low wind speeds is further examined using the Tropical Ocean Global Atmosphere-Tropical Atmosphere Ocean array (TOGA-TAO) moored buoys. Finally, it is shown that there is some evidence that not all of the events can be accounted for by very low wind speeds. This suggests that future work might exploit the occurrence of these events to study other phenomena, such as surface slicks, that may lead to additional geophysical applications of the altimetric data. C1 Univ S Florida, Coll Marine Sci, St Petersburg, FL 33701 USA. NASA, Wallops Flight Facil, Wallops Isl, VA USA. RP Mitchum, GT (reprint author), Univ S Florida, Coll Marine Sci, 140 7th Ave S, St Petersburg, FL 33701 USA. EM mitchum@marine.usf.edu NR 24 TC 14 Z9 14 U1 2 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD AUG PY 2004 VL 21 IS 8 BP 1232 EP 1245 DI 10.1175/1520-0426(2004)021<1232:BOITTR>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 845DL UT WOS:000223215900009 ER PT J AU Webb, PA Essex, EA AF Webb, PA Essex, EA TI A dynamic global model of the plasmasphere SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article DE plasmasphere; electron density; modelling; TEC; GPS; ATS-6 ID TOTAL ELECTRON-CONTENT; RADIO BEACON EXPERIMENT; DENSITY DISTRIBUTION; INNER MAGNETOSPHERE; UPPER IONOSPHERE; FIELD; GPS; TEMPERATURE; PROTONOSPHERE; PLASMAPAUSE AB The three-dimensional Global Plasmasphere Ionosphere Density (GPID) model simulates the global-scale dynamics of the magnetic field-aligned ion and electron densities within the plasmasphere and plasmatrough (L less than or equal to 9) by simultaneously modeling the field-aligned plasma density distributions of several thousand magnetic flux tubes distributed uniformly about the Earth. GPID uses a dynamical diffusive equilibrium approach within each magnetic flux tube that allows it to model the temporal variations in H+ and O+ densities, the dominant ions in the topside ionosphere and plasmasphere. Using the International Reference Ionosphere (IRI) to model the ionosphere and a simple electron density profile above the ionosphere in the polar regions (L > 9), GPID is able to simulate electron densities globally from ground level to an attitude of similar to 50, 000 km. Comparisons of GPID predictions with (1) direct plasmaspheric observations obtained from Low Earth Orbit (LEO) satellites equipped with Global Position System (GPS) receivers, (2) ground-based radio beacon measurements using the Applications Technology Satellite 6 (ATS-6) satellite and (3) several empirical plasmasphere models, show good agreement. This good agreement indicates the value of the GPID model as a tool for investigating the physics of the inner magnetopshere. (C) 2004 Elsevier Ltd. All rights reserved. C1 La Trobe Univ, Cooperat Res Ctr Satellite Syst, Dept Phys, Bundoora, Vic 3086, Australia. RP NASA, GSFC, Nomad Res Inc, Extraterr Phys Lab, Code 690, Greenbelt, MD 20771 USA. EM pwebb@lepvax.gsfc.nasa.gov NR 66 TC 19 Z9 19 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 EI 1879-1824 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD AUG PY 2004 VL 66 IS 12 BP 1057 EP 1073 DI 10.1016/j.jastp.2004.04.001 PG 17 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 842MU UT WOS:000223009300006 ER PT J AU Graebe, A Schuck, EL Lensing, P Putcha, L Derendorf, H AF Graebe, A Schuck, EL Lensing, P Putcha, L Derendorf, H TI Physiological, pharmacokinetic, and pharmacodynamic changes in space SO JOURNAL OF CLINICAL PHARMACOLOGY LA English DT Review DE space flight; pharmacokinetics; microgravity environment; drug dosing; space medicine; pharmacodynamics ID HINDLIMB-SUSPENDED RATS; GRADED WATER IMMERSION; WALL VESSEL BIOREACTOR; BODY-MASS CHANGES; RED-BLOOD-CELLS; SIMULATED MICROGRAVITY; SUSTAINED MICROGRAVITY; ESCHERICHIA-COLI; HUMAN LUNG; IN-SPACE AB Medications have been taken since the first Mercury flight in 1967 and, since then, have been used for several indications such as space motion sickness, sleeplessness, headache, nausea. vomiting back pain, and congestion. As the duration of space missions get longer, it is even more likely that astronauts will encounter some of the acute illnesses that are frequently seen on Earth. Microgravity environment induces several physiological changes in the human body. These changes include cardiovascular degeneration, bone decalcification, decreased plasma volume, blood flow, lymphocyte and eosinophil levels, altered hormonal and electrolyte levels, muscle atrophy decreased blood cell mass, increased immunoglobulin A and M levels, and a decrease in the amount of microsomal P-450 and the activity of some of its dependent enzymes. These changes may be expected to have severe implications on the pharmacokinetic and pharmacodynamic properties of drug substances. C1 Univ Florida, Coll Pharm, Dept Pharmaceut, Gainesville, FL 32610 USA. Rutgers State Univ, Dept Pharm Practice & Adm, Ernest Mario Sch Pharm, Piscataway, NJ 08855 USA. DomApotheke, Essen, Germany. Lyndon B Johnson Space Ctr, Life Sci Res Pharmacol Lab, Houston, TX USA. RP Derendorf, H (reprint author), Univ Florida, Coll Pharm, Dept Pharmaceut, POB 100494, Gainesville, FL 32610 USA. RI Derendorf, Hartmut/B-4628-2012 OI Derendorf, Hartmut/0000-0003-4016-1370 NR 178 TC 36 Z9 42 U1 3 U2 20 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0091-2700 J9 J CLIN PHARMACOL JI J. Clin. Pharmacol. PD AUG PY 2004 VL 44 IS 8 BP 837 EP 853 DI 10.1177/0091270004267193 PG 17 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 840TU UT WOS:000222883600002 PM 15286087 ER PT J AU Prakash, GKS Smart, MC Wang, QJ Atti, A Pleynet, V Yang, B McGrath, K Olah, GA Narayanan, SR Chun, W Valdez, T Surampudi, S AF Prakash, GKS Smart, MC Wang, QJ Atti, A Pleynet, V Yang, B McGrath, K Olah, GA Narayanan, SR Chun, W Valdez, T Surampudi, S TI High efficiency direct methanol fuel cell based on poly(styrenesulfonic) acid (PSSA)-poly(vinylidene fluoride) (PVDF) composite membranes SO JOURNAL OF FLUORINE CHEMISTRY LA English DT Article; Proceedings Paper CT Symposium on Fluorine in Alternative Energy Sources CY SEP 07-11, 2003 CL New York, NY SP Amer Chem Soc DE fuel cells; PSSA-PVDF membrane; semi-IPN network; methanol crossover ID PROTON-EXCHANGE MEMBRANES; POLYMER-ELECTROLYTE; DOPED POLYBENZIMIDAZOLE; CROSSOVER; PERFORMANCE; TRANSPORT; ELECTROOXIDATION; POLYIMIDES AB semi-Interpenetrating polymer network (sIPN) composite membranes consisting of poly(styrenesuflonic) acid (PSSA) and poly(vinylidene fluoride) (PVDF) have been prepared and evaluated as proton exchange membrane electrolytes in direct methanol fuel cells (DMFCs). The membranes fabricated were evaluated in terms of their proton conductivity, methanol permeability, and their performance characteristics in direct methanol fuel cells (DMFCs). PSSA-PVDF membranes demonstrated decreased methanol crossover during operation of direct methanol fuel cells compared to state-of-art Nafion(R)-H membranes, yielding improved efficiency. PSSA-PVDF membranes have been demonstrated to operate efficiently in 1 in. x 1 in. and 2 in. x 2 in. direct methanol fuel cells. Fuel cells operating with PSSA-PVDF membranes were observed to have dramatically lower crossover rates compared to Nafion(R) 117 systems. Greater than 95% reduction in crossover was observed in some cases. These properties of PSSA-PVDF membranes resulted in improved fuel performance and fuel cell efficiencies for direct methanol fuel cells. It was also observed that the PSSA-PVDF membranes behave quite differently compared with Nafion(R)-based systems in terms water management characteristics at the cathode. The best performance with the new membranes was observed with very low oxygen or air flow rates at the cathode which is in contrast to Nation(R)-based systems, which generally require higher flow rates due to excessive water accumulation at the cathode, resulting in flooding. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ So Calif, Donald P & Katherine B Loker Hydrocarbon Res, Dept Chem, Los Angeles, CA 90089 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Prakash, GKS (reprint author), Univ So Calif, Donald P & Katherine B Loker Hydrocarbon Res, Dept Chem, Univ Pk,837 Bloom Walk, Los Angeles, CA 90089 USA. EM gprakash@usc.edu NR 47 TC 60 Z9 60 U1 3 U2 35 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-1139 J9 J FLUORINE CHEM JI J. Fluor. Chem. PD AUG PY 2004 VL 125 IS 8 BP 1217 EP 1230 DI 10.1016/j.jfluchem.2004.05.019 PG 14 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 851LA UT WOS:000223685400006 ER PT J AU Son, SY Allen, JS AF Son, SY Allen, JS TI Visualization of wettability effects on mcirochannel two-phase flow resistance SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. RP Son, SY (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. NR 0 TC 3 Z9 3 U1 1 U2 4 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD AUG PY 2004 VL 126 IS 4 BP 498 EP 498 DI 10.1115/1.1811717 PG 1 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 855QP UT WOS:000223989100005 ER PT J AU Turato, B Reale, O Siccardi, F AF Turato, B Reale, O Siccardi, F TI Water vapor sources of the October 2000 Piedmont flood SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID EVAPORATIVE MOISTURE SOURCES; MEDITERRANEAN REGION; NORTH AMERICA; RIVER-BASIN; PART I; PRECIPITATION; BUDGET; LEE; CYCLOGENESIS; SIMULATIONS AB Very intense mesoscale or synoptic-scale rainfall events can occasionally be observed in the Mediterranean region without any deep cyclone developing over the areas affected by precipitation. In these perplexing cases the synoptic situation can superficially look similar to cases in which very little precipitation occurs. An example is the major precipitation and flooding event that affected Piedmont, Italy, between 13 and 16 October 2000. The emphasis of this study is on the moisture origin and transport. Moisture balances are computed on different space and time scales, revealing that precipitation exceeds evaporation over an area inclusive of Piedmont and the northwestern Mediterranean region, on a time scale encompassing the event and about 2 weeks preceding it. This is suggestive of an important moisture contribution originating from outside the region. A synoptic and dynamic analysis is then performed to outline the potential mechanisms that could have contributed to the large-scale moisture transport. The central part of the work uses a quasi-isentropic water vapor back-trajectory technique. The moisture sources obtained by this technique are compared with the results of the balances and with the synoptic situation to unveil possible dynamic mechanisms and physical processes involved. It is found that moisture sources on a variety of atmospheric scales contribute to this event. First, an important contribution is caused by the extratropical remnants of former Tropical Storm Leslie. The large-scale environment related to this system allows a significant amount of moisture to be carried toward Europe. This happens on a time scale of about 5-15 days preceding the Piedmont event. Second, water vapor intrusions from the African intertropical convergence zone and evaporation from the eastern Atlantic contribute on the 2-5-day time scale. The large-scale moist dynamics appears therefore to be one important factor enabling a moderate Mediterranean cyclone to produce heavy precipitation. Finally, local evaporation from the Mediterranean, water vapor recycling, and orographically induced low-level convergence enhance and concentrate the moisture over the area where heavy precipitation occurs. This happens on a 12-72-h time scale. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Genoa, Ctr Interuniv Ric Monitoraggio Ambientale, I-16126 Genoa, Italy. Univ Maryland, Baltimore, MD 21201 USA. RP NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 910, Greenbelt, MD 20771 USA. EM Oreste.Reale.1@gsfc.nasa.gov NR 30 TC 44 Z9 44 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X EI 1525-7541 J9 J HYDROMETEOROL JI J. Hydrometeorol. PD AUG PY 2004 VL 5 IS 4 BP 693 EP 712 DI 10.1175/1525-7541(2004)005<0693:WVSOTO>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 845PP UT WOS:000223257100008 ER PT J AU Delaney, MP Knoechel, R AF Delaney, MP Knoechel, R TI Turbulence effects on cold ocean microbial communities: an enclosure study SO JOURNAL OF MARINE SYSTEMS LA English DT Article; Proceedings Paper CT Joint Meeting of the American-Society-for-Limnology-and-Oceanography/American-Geophysical-Uni on CY FEB, 2002 CL HONOLULU, HI SP Amer Soc Limnol & Oceanog, Amer Geophys Union DE cold ocean; microbial food web; small-scale turbulence ID SMALL-SCALE TURBULENCE; MARINE MICROCOSMS; FOOD-WEB; GROWTH; DINOFLAGELLATE; PLANKTON; RATES AB There have been numerous studies on turbulence effects on macro- and zooplankton during the last decade, but studies on microplankton have been fewer, sometimes contradictory, and conducted largely under temperate conditions. In the present study, an enclosure experiment was carried out with natural seawater of Logy Bay, Newfoundland to determine the effects of turbulence on heterotrophic and autotrophic growth in the presence and absence of micrograzers. The experiment was conducted in February with water temperatures at 0 degreesC. We found no difference in bacterial growth between the static and turbulence enclosures in either the presence or absence of micrograzers. Heterotrophic nanoflagellate growth, however, was found to be significantly higher in the presence of turbulence but only when micrograzers were absent. A similar pattern was found with the small autotrophic community, determined as chlorophyll a passing through a 5-mum filter, in which growth was significantly higher with turbulence but only when micrograzers were absent. Turbulence significantly enhanced growth rates of the large autotrophic community (chlorophyll a retained by a 5mum filter), which was largely composed of diatoms, both in the presence and absence of grazers. These results suggest that turbulence effects are small under cold ocean conditions, but increase with the size of the organism. It thus appears that turbulence could affect patterns of biogenic carbon export differentially, being dependent upon the conditions of the marine environment. (C) 2004 Elsevier B.V. All rights reserved. C1 Mem Univ Newfoundland, Ctr Ocean Sci, St Johns, NF A1C 5S7, Canada. Mem Univ Newfoundland, Dept Biol, St Johns, NF A1C 5S7, Canada. RP Delaney, MP (reprint author), NASA, Goddard Space Flight Ctr, GEST Ctr, Mail Code 900-1, Greenbelt, MD 20771 USA. EM mpdelane@umbc.edu NR 20 TC 2 Z9 2 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-7963 J9 J MARINE SYST JI J. Mar. Syst. PD AUG PY 2004 VL 49 IS 1-4 BP 123 EP 131 DI 10.1016/j.jmarsys.2003.10.006 PG 9 WC Geosciences, Multidisciplinary; Marine & Freshwater Biology; Oceanography SC Geology; Marine & Freshwater Biology; Oceanography GA 861CY UT WOS:000224394900010 ER PT J AU Kok, P Braunstein, SL Dowling, JP AF Kok, P Braunstein, SL Dowling, JP TI Quantum lithography, entanglement and Heisenberg-limited parameter estimation SO JOURNAL OF OPTICS B-QUANTUM AND SEMICLASSICAL OPTICS LA English DT Article; Proceedings Paper CT 1st International Symposium on Fluctuations and Noise CY JUN 01-04, 2003 CL SANTA FE, NM SP SPIE, Natl Semicond Corp, Fred Seitz Mat Res Lab, Natl High Magnet Field Lab, Natl Sci Fdn, Telecommun Task Force DE quantum imaging; quantum metrology; shot-noise; standard quantum limit ID PHASE MEASUREMENT; NOISE; DIFFRACTION; EVOLUTION; STATE AB We explore the intimate relationship between quantum lithography, Heisenberg-limited parameter estimation and the rate of dynamical evolution of quantum states. We show how both the enhanced accuracy in measurements and the increased resolution in quantum lithography follow from the use of entanglement. Mathematically, the hyper-resolution of quantum lithography appears naturally in the derivation of Heisenberg-limited parameter estimation. We also review recent experiments offering a proof of the principle of quantum lithography, and we address the question of state preparation and the fabrication of suitable photoresists. C1 Hewlett Packard Labs, Bristol BS34 8QZ, Avon, England. Univ York, York YO10 5DD, N Yorkshire, England. CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Pasadena, CA USA. RP Hewlett Packard Labs, Filton Rd,Stoke Gifford, Bristol BS34 8QZ, Avon, England. EM pieter.kok@hp.com RI Braunstein, Samuel/A-5501-2009; Kok, Pieter/B-1658-2010; DOWLING, JONATHAN/L-2749-2013 NR 26 TC 23 Z9 23 U1 1 U2 9 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1464-4266 J9 J OPT B-QUANTUM S O JI J. Opt. B-Quantum Semicl. Opt. PD AUG PY 2004 VL 6 IS 8 SI SI BP S811 EP S815 AR PII S1464-4266(04)72018-2 DI 10.1088/1464-4266/6/8/029 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA 877JO UT WOS:000225565000031 ER PT J AU Lee, H Kok, P Williams, CP Dowling, JP AF Lee, H Kok, P Williams, CP Dowling, JP TI From linear optical quantum computing to Heisenberg-limited interferometry SO JOURNAL OF OPTICS B-QUANTUM AND SEMICLASSICAL OPTICS LA English DT Article; Proceedings Paper CT 1st International Symposium on Fluctuations and Noise CY JUN 01-04, 2003 CL SANTA FE, NM SP SPIE, Natl Semicond Corp, Fred Seitz Mat Res Lab, Natl High Magnet Field Lab, Natl Sci Fdn, Telecommun Task Force DE quantum imaging; quantum metrology; shot-noise limit; Heisenberg limit; quantum computing ID PHOTON-NUMBER; SINGLE-PHOTON; PHASE-SHIFTS; STATES; NOISE; GENERATION; SU(2); GATE AB The working principles of linear optical quantum computing are based on photodetection, namely, projective measurements. The use of photodetection can provide efficient nonlinear interactions between photons at the single-photon level, which is technically problematic otherwise. We report an application of such a technique to prepare quantum correlations as an important resource for Heisenberg-limited optical interferometry, where the sensitivity of phase measurements can be improved beyond the usual shot-noise limit. Furthermore, using such nonlinearities, optical quantum non-demolition measurements can now be carried out easily at the single-photon level. C1 CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Pasadena, CA 91109 USA. Hewlett Packard Labs, Bristol BS34 8QZ, Avon, England. RP CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Sect 367,MS 126-347,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jonathan.p.dowling@jpl.nasa.gov RI Kok, Pieter/B-1658-2010; DOWLING, JONATHAN/L-2749-2013 NR 49 TC 4 Z9 4 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1464-4266 J9 J OPT B-QUANTUM S O JI J. Opt. B-Quantum Semicl. Opt. PD AUG PY 2004 VL 6 IS 8 SI SI BP S796 EP S800 AR PII S1464-4266(04)72679-8 DI 10.1088/1464-4266/6/8/026 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA 877JO UT WOS:000225565000028 ER PT J AU Kim, Y Mesbahi, M Hadaegh, FY AF Kim, Y Mesbahi, M Hadaegh, FY TI Multiple-spacecraft reconfiguration through collision avoidance, bouncing, and stalemate SO JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS LA English DT Article DE multiple-spacecraft reconfiguration; state-constrained optimal control; collision avoidance; bouncing; stalemate; heuristic algorithms ID FORMATION FLYING CONTROL; COORDINATION; CONSTRAINTS; RESOLUTION; SYSTEMS AB We consider constrained multiple-spacecraft reconfigurations outside a gravity well in deep space. As opposed to the single-spacecraft scenario, such reconfigurations involve collision avoidance constraints that can be embedded in a nonconvex, state-constrained optimal control problem. Due to the difficulties in solving this general class of optimal control problems, we adopt a heuristically motivated approach to multiple-spacecraft reconfigurations. Then, we proceed to prove the convergence properties of the proposed approach for reconfigurations involving an arbitrary number of spacecraft. C1 Univ Washington, Dept Aeronaut & Astronaut, Seattle, WA 98195 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Kim, Y (reprint author), Univ Washington, Dept Aeronaut & Astronaut, Seattle, WA 98195 USA. NR 16 TC 37 Z9 37 U1 1 U2 6 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-3239 J9 J OPTIMIZ THEORY APP JI J. Optim. Theory Appl. PD AUG PY 2004 VL 122 IS 2 BP 323 EP 343 DI 10.1023/B:JOTA.0000042524.57088.8b PG 21 WC Operations Research & Management Science; Mathematics, Applied SC Operations Research & Management Science; Mathematics GA 856ER UT WOS:000224029000005 ER PT J AU Fu, LL AF Fu, LL TI Latitudinal and frequency characteristics of the westward propagation of large-scale oceanic variability SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID BAROCLINIC ROSSBY WAVES; ZONAL EQUATORIAL CURRENTS; TROPICAL NORTH PACIFIC; SEA-SURFACE HEIGHT; PLANETARY-WAVES; TOPEX/POSEIDON; ALTIMETER; INSTABILITIES; BOUNDARIES; FLOW AB In the open ocean away from the equator, westward propagation is a ubiquitous characteristic of oceanic variability. The objectives of the study are to investigate the latitudinal dependence of the frequency of westward-propagating variability. Two-dimensional Fourier analysis in frequency and zonal wavenumber is applied to time-longitude records of sea surface height data obtained from the Ocean Topography Experiment (TOPEX)/Poseidon mission. The focus of the study is placed on spatial scales larger than the mesoscale. The frequency of westward propagation is generally lower than the critical frequency of the first-mode baroclinic Rossby waves, as expected from the conventional theory of Rossby waves in a midlatitude ocean. However, westward propagation with frequency of up to 2 times the critical frequency is also observed at most latitudes. This supercritical propagation can be explained by the effects of the vertical shear of the mean flow at midlatitudes and by the effects of the equatorial wave guide at the tropical latitudes. Westward propagation with frequency much higher than the critical frequency (by a factor of 5-10) is also observed at certain latitudes in all oceans. The most energetic cases are found along the latitudes of strong zonal jets, including the Brazil/Malvinas Confluence, the Agulhas Return Current, and the Gulf Stream Extension, with decreasing variance in the order. The high-frequency westward propagation exhibits the frequency and wavenumber characteristics of barotropic Rossby waves. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fu, LL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM llf@pacific.jpl.nasa.gov NR 37 TC 18 Z9 18 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD AUG PY 2004 VL 34 IS 8 BP 1907 EP 1921 DI 10.1175/1520-0485(2004)034<1907:LAFCOT>2.0.CO;2 PG 15 WC Oceanography SC Oceanography GA 844ED UT WOS:000223139300008 ER PT J AU Ray, RD Egbert, GD AF Ray, RD Egbert, GD TI The global S-1 tide SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID OCEAN TIDES; WORLD OCEAN; ANGULAR-MOMENTUM; NORMAL-MODES; SEMIDIURNAL VARIATIONS; ATMOSPHERIC-PRESSURE; DIURNAL CYCLE; SURFACE WIND; SEA; OSCILLATIONS AB The small S-1 ocean tide is caused primarily by diurnal atmospheric pressure loading. Its excitation is therefore unlike any other diurnal tide; in particular, pressure loading is maximum near the equator where the diurnal gravitational potential is zero. The global character of the S-1 tide is here determined by numerical modeling and by analysis of Ocean Topography Experiment (TOPEX)/Poseidon satellite altimeter data. The two approaches yield reasonably consistent results. Amplitudes exceeding 1 cm in several regions are further confirmed by comparison with coastal tide gauges. Notwithstanding their excitation differences, S-1 and other diurnal tides are found to share several common features, such as relatively large amplitudes in the Arabian Sea, the Labrador Sea, the Sea of Okhotsk, and the Gulf of Alaska. The most noticeable difference is the lack of an S-1 Antarctic Kelvin wave. These similarities and differences can be explained in terms of the coherences between near-diurnal oceanic normal modes and the underlying tidal forcings. Whereas gravitational diurnal tidal forces excite primarily a 28-h Antarctic-Pacific mode, the S-1 air tide excites several other near-diurnal modes, none of which has large amplitudes near Antarctica. C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. Oregon State Univ, Coll Oceanog & Atmospher Sci, Corvallis, OR 97331 USA. RP NASA, Goddard Space Flight Ctr, Terr Phys Lab, Code 926, Greenbelt, MD 20771 USA. EM richard.ray@gsfc.nasa.gov RI Ray, Richard/D-1034-2012; OI Egbert, Gary/0000-0003-1276-8538 NR 49 TC 30 Z9 32 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 EI 1520-0485 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD AUG PY 2004 VL 34 IS 8 BP 1922 EP 1935 DI 10.1175/1520-0485(2004)034<1922:TGST>2.0.CO;2 PG 14 WC Oceanography SC Oceanography GA 844ED UT WOS:000223139300009 ER PT J AU Lee, T Fukumori, I Tang, B AF Lee, T Fukumori, I Tang, B TI Temperature advection: Internal versus external processes SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID 1997-98 EL-NINO; EQUATORIAL PACIFIC; HEAT-BUDGET; OCEAN; MECHANISMS; MODEL AB Local advection of temperature is the inner product of vector velocity and spatial gradient of temperature. This product is often integrated spatially to infer temperature advection over a region. However, the contribution along an individual direction can be dominated by internal processes that redistribute heat within the domain but do not control the heat content of the domain. A new formulation of temperature advection is introduced to elucidate external heat source and sink that control the spatially averaged temperature. It is expressed as the advection of interfacial temperature relative to the spatially averaged temperature of the domain by inflow normal to the interface. It gives a total advection of temperature that is identical to the spatial integration of local temperature advection, yet the contributions along individual directions depict external processes. The differences between the two formulations are illustrated by analyzing zonal advection of near-surface temperature in the eastern equatorial Pacific during the 1997-98 El Nino and the subsequent La Nina by an ocean general circulation model. The new formulation highlights the advection of warmer water at the western side of the Nino-3 region into (out of) the region to create part of the warming (cooling) tendency during El Nino (La Nina). In contrast, the traditional formulation is dominated by the effect of tropical instability waves within the region that redistribute heat internally. The difference between the two formulations suggests a need for caution in discerning mechanisms controlling heat content of a region. Spatial integration of local temperature advection does not explain external processes that control a domain's heat content. The conclusion applies not only to the advection of oceanic temperature, but also to that of any property in any medium. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lee, T (reprint author), CALTECH, Jet Prop Lab, MS 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM tlee@pacific.jpl.nasa.gov NR 12 TC 31 Z9 31 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD AUG PY 2004 VL 34 IS 8 BP 1936 EP 1944 DI 10.1175/1520-0485(2004)034<1936:TAIVEP>2.0.CO;2 PG 9 WC Oceanography SC Oceanography GA 844ED UT WOS:000223139300010 ER PT J AU Hase, F Hannigan, JW Coffey, MT Goldman, A Hopfner, M Jones, NB Rinsland, CP Wood, SW AF Hase, F Hannigan, JW Coffey, MT Goldman, A Hopfner, M Jones, NB Rinsland, CP Wood, SW TI Intercomparison of retrieval codes used for the analysis of high-resolution, ground-based FTIR measurements SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE infrared spectroscopy; atmospheric trace gases; radiative transfer; retrieval algorithms ID INFRARED SPECTROSCOPIC MEASUREMENTS; CARBON-MONOXIDE; ERROR ANALYSIS; SOLAR SPECTRA; KITT PEAK; OZONE; DATABASE; EDITION; KASIMA; GASES AB A rigorous and systematic intercomparison of codes used for the retrieval of trace gas profiles from high-resolution ground-based solar absorption FTIR measurements is presented for the first time. Spectra were analyzed with the two widely used independent, retrieval codes: SFIT2 and PROFFIT9. Vertical profiles Of O(3) HNO(3), HDO, and N(2)O were derived from the same set of typical observed spectra. Analysis Of O(3) was improved by using updated line parameters. It is shown that profiles and total column amounts are in excellent agreement, when similar constraints are applied, and that the resolution kernel matrices are also consistent. Owing to the limited altitude resolution of ground-based observations, the impact of the constraints on the solution is not negligible. It is shown that the results are also compatible for independently chosen constraints. Perspectives for refined constraints are discussed. It can be concluded that the error budget introduced by the radiative transfer code and the retrieval algorithm on total columns deduced from high-resolution ground-based solar FTIR spectra is below 1%. (C) 2004 Elsevier Ltd. All rights reserved. C1 Forschungszentrum Karlsruhe, IMK, ASF, D-76021 Karlsruhe, Germany. Natl Inst Water & Atmospher Res Ltd, Central Otago, New Zealand. NASA, Langley Res Ctr, Hampton, VA USA. Univ Wollongong, Dept Chem, Wollongong, NSW 2522, Australia. Univ Denver, Dept Phys, Denver, CO 80208 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. RP Hase, F (reprint author), Forschungszentrum Karlsruhe, IMK, ASF, Postbach 3640, D-76021 Karlsruhe, Germany. EM frank.hase@imk.fzk.de; jamesw@nacr.ucar.edu; coffey@acd.ucar.edu; goldman@acd.ucar.edu; michael.hoepfner@imk.fzk.de; njones@uow.edu.au; c.p..rinsland@larc.nasa.gov; s.wood@niwa.co.nz RI Hopfner, Michael/A-7255-2013; Hase, Frank/A-7497-2013; Jones, Nicholas/G-5575-2011 OI Hopfner, Michael/0000-0002-4174-9531; Jones, Nicholas/0000-0002-0111-2368 NR 49 TC 146 Z9 149 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 AUG 1 PY 2004 VL 87 IS 1 BP 25 EP 52 DI 10.1016/j.jqsrt.2003.12.008 PG 28 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 830VI UT WOS:000222151600003 ER PT J AU Kerslake, TW AF Kerslake, TW TI Effect of voltage level on power system design for solar electric propulsion missions SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB This paper presents study results quantifying the benefits of higher voltage, electric power system designs for a typical solar electric propulsion spacecraft Earth orbiting mission. A conceptual power system architecture was defined and design points were generated for several system voltages using state-of-the-art or advanced technologies. A 300-V "direct-drive" architecture was also analyzed to assess the benefits of directly powering the electric thruster from the photovoltaic array without up-conversion. Computational models were exercised to predict the performance and size power system components to meet spacecraft mission requirements. Pertinent space environments were calculated for the mission trajectory and an electron current collection model was developed to estimate photovoltaic array losses due to natural and induced plasma environments. The secondary benefits of power system mass savings for spacecraft propulsion and attitude control systems were also quantified. Results indicate that considerable spacecraft wet mass savings were achieved by the 300-V and 300-V direct-drive architectures. C1 NASA, Glenn Res Ctr, Power & Propuls Off, Cleveland, OH USA. RP Kerslake, TW (reprint author), NASA, Glenn Res Ctr, Power & Propuls Off, 2100 Brookpk Rd, Cleveland, OH USA. EM thomas.w.kerslake@nasa.gov NR 35 TC 0 Z9 0 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD AUG PY 2004 VL 126 IS 3 BP 936 EP 944 DI 10.1115/1.1710523 PG 9 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA 845KT UT WOS:000223242200019 ER PT J AU Chandler, WS Whitlock, CH Stackhouse, PW AF Chandler, WS Whitlock, CH Stackhouse, PW TI NASA climatological data for renewable energy assessment SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID RADIATION AB This article presents the latest parameters and delivery methods that provide global solar energy and meteorological resources on the Internet. Over the past several years the number of parameters in the Surface meteorology and Solar Energy Data Set has tripled. The newest parameters include solar geometry, a suite of wind speed and wind direction data, diffuse, direct normal and tilted surface solar irradiance. Requests by users and recommendations by the renewable energy industry, have prompted the growth. C1 Sci Applicat Int Corp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Chandler, WS (reprint author), Sci Applicat Int Corp, 1 Enterprise Pkwy,Suite 300, Hampton, VA 23666 USA. EM w.s.chandler@larc.nasa.gov NR 13 TC 14 Z9 14 U1 0 U2 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD AUG PY 2004 VL 126 IS 3 BP 945 EP 949 DI 10.1115/1.1748466 PG 5 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA 845KT UT WOS:000223242200020 ER PT J AU Feuillade, C Chu, D Clay, CS AF Feuillade, C Chu, D Clay, CS TI Space-time variations of the acoustic field scattered from a penetrable isovelocity wedge SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID DENSITY CONTRAST WEDGE; IMPULSE-RESPONSE; DIFFRACTION AB The formalism of D. Chu [J. Acoust. Soc. Am. 86, 1883-1896 (1989)] is used to detail the spatial and time domain, variations of the scattered field of a penetrable isovelocity wedge. The direct, reflected, and diffracted field components, and their relationships, are investigated. Since diffractions often dominate rough surface scattering, these waves are carefully studied, with particular emphasis on the wave phenomena and transition behavior around the forward scattering shadow boundary, where the causal relationship between the direct and diffracted fields is specifically examined. The wave processes here, and above and below the geometrical shadow zone, lead to complicated temporal and azimuthal variations of the field. The phenomenon of diffractions associated with specular reflections of the source in the wedge faces is also studied., Among the conclusions reached are (i) direct/reflected impulses arrive first, followed by and separated from their associated diffractions; (ii) the direct/reflected impulse is a delta function, with arrival predicted by the source-receiver raypath travel time, and amplitude determined by spherical spreading and reflection/transmission coefficients at the wedge faces; and (iii) diffractions are causally associated with direct/reflected impulses interacting with the wedge apex, and their amplitude depends on the degree of acoustic shadowing at the apex. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Woods Hole Oceanog Inst, Dept Ocean Phys& Engn, Woods Hole, MA 02543 USA. Univ Wisconsin, Geophys & Polar Res Ctr, Madison, WI 53706 USA. RP Feuillade, C (reprint author), USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. EM cf@nrlssc.navy.mil NR 21 TC 2 Z9 2 U1 0 U2 0 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 AUG PY 2004 VL 116 IS 2 BP 777 EP 789 DI 10.1121/1.1772394 PG 13 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 845YQ UT WOS:000223281800014 ER PT J AU Verrilli, MJ Opila, EJ Calomino, A Kiser, JD AF Verrilli, MJ Opila, EJ Calomino, A Kiser, JD TI Effect of environment on the stress-rupture behavior of a carbon-fiber-reinforced silicon carbide ceramic matrix composite SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID WOVEN C/SIC COMPOSITES; WATER-VAPOR; OXIDATION; TEMPERATURE AB Stress-rupture tests were conducted in air, under vacuum, and in steam-containing environments to identify the failure modes and degradation mechanisms of a carbon-fiber-reinforced silicon carbide (C/SiC) composite at two temperatures, 600degrees and 1200degreesC. Stress-rupture lives in air and steam-containing environments (50-80% steam with argon) are similar for a stress of 69 MPa at 1200degreesC. Lives of specimens tested in a 20% steam/argon environment were about twice as long. For tests conducted at 600degreesC, composite life in 20% steam/argon was 30 times longer than life in air. Thermogravimetric analysis of the carbon fibers was conducted under conditions similar to the stress-rupture tests. The oxidation rate of the fibers in the various environments correlated with the composite stress-rupture lives. Examination of the failed specimens indicated that oxidation of the carbon fibers was the primary damage mode for specimens tested in air and steam environments at both temperatures. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Verrilli, MJ (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 19 TC 26 Z9 26 U1 2 U2 7 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43086-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD AUG PY 2004 VL 87 IS 8 BP 1536 EP 1542 PG 7 WC Materials Science, Ceramics SC Materials Science GA 850RJ UT WOS:000223629800021 ER PT J AU Jacobson, NS Liu, ZK Kaufman, L Zhang, F AF Jacobson, NS Liu, ZK Kaufman, L Zhang, F TI Thermodynamic modeling of the YO1.5-ZrO2 system SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ZRO2-Y2O3 SYSTEM; PHASE-EQUILIBRIA; ZIRCONIA; DIAGRAMS AB The YO1.5-ZrO2 system consists of five solid solutions, one liquid solution, and one intermediate compound. A thermodynamic description of this system is developed, which allows calculation of the phase diagram and thermodynamic properties. Two different solution models are used-a neutral species model with YO1.5 and ZrO2 as the components and a charged species model with Y3+, Zr4+, O2-, and vacancies as components. For each model, regular and subregular solution parameters are derived from selected phase equilibrium and thermodynamic data. The neural species and charged species modeling results are compared. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Penn State Univ, Dept Mat Sci & Engn, State Coll, PA 16803 USA. Computherm LLC, Madison, WI 53719 USA. RP Jacobson, NS (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RI Liu, Zi-Kui/A-8196-2009 OI Liu, Zi-Kui/0000-0003-3346-3696 NR 51 TC 11 Z9 12 U1 0 U2 10 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43086-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD AUG PY 2004 VL 87 IS 8 BP 1559 EP 1566 PG 8 WC Materials Science, Ceramics SC Materials Science GA 850RJ UT WOS:000223629800025 ER PT J AU Anicich, VG Wilson, P McEwan, MJ AF Anicich, VG Wilson, P McEwan, MJ TI A SIFT ion-molecule study of some reactions in Titan's atmosphere. Reactions of N+, N-2(+) and HCN+ with CH4, C2H2, and C2H4 SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID IONOSPHERE; CHEMISTRY; CLOUDS AB The results of a study of the ion-molecule reactions of N+, N-2(+), and HCN+ with methane, acetylene, and ethylene are reported. These studies were performed using the FA-SIFT at the University of Canterbury. The reactions studied here are important to understanding the ion chemistry in Titan's atmosphere. N+ and N-2(+) are the primary ions formed by photo-ionization and electron impact in Titan's ionosphere and drive Titan's ion chemistry. It is therefore very important to know how these ions react with the principal trace neutral species in Titan's atmosphere: Methane, acetylene, and ethylene. While these reactions have been studied before the product channels have been difficult to define as several potential isobaric products make a definitive answer difficult. Mass overlap causes difficulties in making unambiguous species assignments in these systems. Two discriminators have been used in this study to resolve the mass overlap problem. They are deuterium labeling and also the differences in reactivities of each isobar with various neutral reactants. Several differences have been found from the products in previous work. The HCN+ ion is important in both Titan's atmosphere and in the laboratory. (C) 2004 American Society for Mass Spectrometry. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Anicich, VG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 183-301, Pasadena, CA 91109 USA. EM Vincent.G.Anicich@jpl.nasa.gov NR 13 TC 27 Z9 27 U1 0 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD AUG PY 2004 VL 15 IS 8 BP 1148 EP 1155 DI 10.1016/j.jasms.2004.04.005 PG 8 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 843AZ UT WOS:000223048500004 PM 15276161 ER PT J AU Marshak, A Knyazikhin, Y Evans, KD Wiscombe, WJ AF Marshak, A Knyazikhin, Y Evans, KD Wiscombe, WJ TI The "RED versus NIR'' plane to retrieve broken-cloud optical depth from ground-based measurements SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SOLAR RADIOMETRIC MEASUREMENTS; RADIATIVE-TRANSFER; VEGETATION; THICKNESS; ALBEDO; INDEX; IRRADIANCE; ABSORPTION; SCATTERING; ALGORITHM AB A new method for retrieving cloud optical depth from ground-based measurements of zenith radiance in the red ( RED) and near-infrared (NIR) spectral regions is introduced. Because zenith radiance does not have a one-to-one relationship with optical depth, it is absolutely impossible to use a monochromatic retrieval. On the other side, algebraic combinations of spectral radiances, such as normalized difference cloud index (NDCI), while largely removing nonuniqueness and the radiative effects of cloud inhomogeneity, can result in poor retrievals due to its insensitivity to cloud fraction. Instead, both RED and NIR radiances as points on the "RED versus NIR'' plane are proposed to be used for retrieval. The proposed retrieval method is applied to Cimel measurements at the Atmospheric Radiation Measurements ( ARM) site in Oklahoma. Cimel, a multichannel sun photometer, is a part of the Aerosol Robotic Network (AERONET) - a ground-based network for monitoring aerosol optical properties. The results of retrieval are compared with the ones from microwave radiometer (MWR) and multifilter rotating shadowband radiometer (MFRSR) located next to Cimel at the ARM site. In addition, the performance of the retrieval method is assessed using a fractal model of cloud inhomogeneity and broken cloudiness. The preliminary results look very promising both theoretically and from measurements. C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Boston Univ, Dept Geog, Boston, MA 02215 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. RP Marshak, A (reprint author), NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Code 913, Greenbelt, MD 20771 USA. EM Alexander.Marshak@nasa.gov RI Wiscombe, Warren/D-4665-2012; Marshak, Alexander/D-5671-2012 OI Wiscombe, Warren/0000-0001-6844-9849; NR 35 TC 23 Z9 25 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD AUG PY 2004 VL 61 IS 15 BP 1911 EP 1925 DI 10.1175/1520-0469(2004)061<1911:TRVNPT>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 843JM UT WOS:000223074900005 ER PT J AU Noel, V Chepfer, H AF Noel, V Chepfer, H TI Study of ice crystal orientation in cirrus clouds based on satellite polarized radiance measurements SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INHOMOGENEOUS HEXAGONAL MONOCRYSTALS; ADEOS-POLDER MEASUREMENTS; SOLAR RADIATIVE-TRANSFER; MICROPHYSICAL PROPERTIES; MULTIPLE-SCATTERING; SINGLE-SCATTERING; LIGHT-SCATTERING; LIDAR; PARTICLES; PHASE AB goal of this paper is to retrieve information about ice particle orientation in cirrus clouds. This is achieved by comparing simulations of sunlight reflection on a cirrus cloud with measurements of polarized radiances from the spaceborne instrument Polarization and Directionality of the Earth's Reflectance (POLDER-1) on Advanced Earth Observing Satellite-1 (ADEOS-1). Results show that horizontal orientation of crystals can be spotted by the presence of a local maximum of polarized radiance in the direction of specular reflection. The angular width of the local maximum is shown to contain information on the particle maximum deviation angle, while the maximum intensity can provide information on particle shape and relative concentrations of ice crystals, horizontally and randomly oriented. The study of 31 ice cloud cases show that in 80% of them, the deviation angle is less than 38. Also, the relative concentration of horizontally oriented crystals is less than 21%, depending on the angular distribution used for crystal deviation. C1 Analyt Serv & Mat Inc, Hampton, VA 23666 USA. Ecole Polytech, Meteorol Dynam Lab, Palaiseau, France. RP NASA, Langley Res Ctr, Mail Stop 435, Hampton, VA 23681 USA. EM v.r.noel@larc.nasa.gov RI Noel, Vincent/C-3702-2013 OI Noel, Vincent/0000-0001-9494-0340 NR 37 TC 39 Z9 45 U1 1 U2 6 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 AUG PY 2004 VL 61 IS 16 BP 2073 EP 2081 DI 10.1175/1520-0469(2004)061<2073:SOICOI>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 845PM UT WOS:000223256800006 ER PT J AU Rajendran, K Krishnamurti, TN Misra, V Tao, WK AF Rajendran, K Krishnamurti, TN Misra, V Tao, WK TI An empirical cumulus parameterization scheme for a global spectral model SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article ID FREQUENCY INTRASEASONAL OSCILLATIONS; TROPICAL CLOUD CLUSTERS; LATENT-HEAT RELEASE; PHYSICAL INITIALIZATION; VERTICAL PROFILES; RAINFALL RATES; MOISTURE BUDGETS; WESTERN PACIFIC; BASIC MODES; WAVE-CISK AB Realistic vertical heating and drying profiles in a cumulus scheme is important for obtaining accurate weather forecasts. A new empirical cumulus parameterization scheme, based on a procedure to improve the vertical distribution of heating and moistening over the tropics is developed. The empirical cumulus parameterization scheme (ECPS) utilizes observed profiles of Tropical Rainfall Measuring Mission (TRMM) based apparent heat source (Q(1)) and the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis based apparent moisture sink (Q(2)). A dimension reduction technique through rotated principal component analysis (RPCA) is performed on the vertical profiles of heating and drying over the convective regions of the tropics, to obtain the dominant modes of variability. Analysis suggests that most of the variance associated with the observed profiles can be explained by retaining the first three modes. The ECPS then applies a statistical approach, in which Q(1) and Q(2) are expressed as a linear combination of the first three dominant principal components which distinctly explain variance in the troposphere as a function of the prevalent large-scale dynamics. The principal component (PC) score, which quantifies the contribution of each PC to the corresponding loading profile, is estimated through a multiple screening regression method which yields the PC score as a function of the large-scale variables. The profiles of Q(1) and Q(2) thus obtained are found to match well with the observed profiles. The impact of the ECPS is investigated in a series of short range (1-3 day) prediction experiments, using the Florida State University global spectral model (FSUGSM, T126L14). Comparisons between short range ECPS forecasts and those with the modified Kuo scheme, show a very marked improvement in the skill in ECPS forecasts. This improvement in the forecast skill with ECPS emphasizes the importance of incorporating realistic vertical distributions of heating and drying in the model cumulus scheme. This also suggests that in the absence of explicit models for convection, the proposed statistical scheme improves the modeling of the vertical distribution of heating and moistening in areas of deep convection. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Inst Global Environm & Soc Inc, Ctr Ocean Land Atmosphere Studies, Calverton, MD USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Rajendran, K (reprint author), Meteorol Res Inst, 1-1 Nagamine, Tsukuba, Ibaraki 3050052, Japan. EM rajend@mri-jma.go.jp RI Rajendran, Kavirajan/C-3334-2009 OI Rajendran, Kavirajan/0000-0002-9437-4729 NR 44 TC 5 Z9 5 U1 0 U2 1 PU METEOROLOGICAL SOC JPN PI TOKYO PA C/O JPN METEOROL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, JAPAN SN 0026-1165 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD AUG PY 2004 VL 82 IS 4 BP 989 EP 1006 DI 10.2151/jmsj.2004.989 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 862QE UT WOS:000224505000002 ER PT J AU Marshburn, TH Legome, E Sargsyan, A Li, SMJ Noble, VA Dulchavsky, SA Sims, C Robinson, D AF Marshburn, TH Legome, E Sargsyan, A Li, SMJ Noble, VA Dulchavsky, SA Sims, C Robinson, D TI Goal-directed ultrasound in the detection of long-bone fractures SO JOURNAL OF TRAUMA-INJURY INFECTION AND CRITICAL CARE LA English DT Article; Proceedings Paper CT Annual Meeting of the Aerospace-Medical-Association CY MAY 04-09, 2002 CL Montreal, CANADA SP Aerospace Med Assoc DE ultrasound; fractures; humerus; femur ID SONOGRAPHIC DETECTION; DIAGNOSIS; ULTRASONOGRAPHY; ANKLE; INJURIES AB Background New portable ultrasound (US) systems are capable of detecting fractures in the remote setting. However, the accuracy of ultrasound by physicians with minimal ultrasound training is unknown. Methods: After one hour of standardized training, physicians with minimal US experience clinically evaluated patients presenting with pain and trauma to the upper arm or leg. The investigators then performed a long-bone US evaluation, recording their impression of fracture presence or absence. Results of the examination were compared with routine plain or computer aided radiography (CT). Results: 58 patients were examined. The sensitivity and specificity of US were 92.9% and 83.3%, and of the physical examination were 78.6% and 90.0%, respectively. US provided improved sensitivity with less specificity compared with physical examination in the detection of fractures in long bones. Conclusion: Ultrasound scans by minimally trained clinicians may be used to rule out a long-bone fracture in patients with a medium to low probability of fracture. C1 NASA, Lyndon B Johnson Space Ctr, Off Space Med, Houston, TX 77058 USA. NYU Med Ctr, Bellevue Hosp, New York, NY 10016 USA. Wyle Labs, Adv Project, Houston, TX USA. Mt Auburn Hosp, Dept Emergency, Cambridge, MA USA. Massachusetts Gen Hosp, Brigham & Womens Hosp Harvard Affiliated Emergenc, Dept Emergency Med, Boston, MA 02114 USA. Hermann Hosp, Dept Emergency Med, Houston, TX USA. Massachusetts Gen Hosp, Dept Surg, Boston, MA 02114 USA. Detroit Receiving Hosp & Univ Hlth Ctr, Dept Surg, Detroit, MI USA. RP Marshburn, TH (reprint author), NASA, Lyndon B Johnson Space Ctr, Off Space Med, Mail Code SD2,2101 NASA Rd 1, Houston, TX 77058 USA. NR 23 TC 72 Z9 72 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0022-5282 J9 J TRAUMA JI J. Trauma-Injury Infect. Crit. Care PD AUG PY 2004 VL 57 IS 2 BP 329 EP 332 DI 10.1097/01.TA.0000088005.35520.CB PG 4 WC Critical Care Medicine; Surgery SC General & Internal Medicine; Surgery GA 859YG UT WOS:000224303700025 PM 15345981 ER PT J AU Sorrentino, C Roy, NK Chambers, RC Courtney, SC Wirgin, I AF Sorrentino, C Roy, NK Chambers, RC Courtney, SC Wirgin, I TI B[a]P-DNA binding in early life-stages of Atlantic tomcod: population differences and chromium modulation SO MARINE ENVIRONMENTAL RESEARCH LA English DT Article; Proceedings Paper CT 12th International Symposium on Pollutant Responses in Marine Organisms (PRIMO 12) CY MAY 09, 2002-MAY 13, 2003 CL Safety Harbor, FL SP Natl Inst Environm Hlth Sci, Int Soc Study Xenobiot, Univ Florida, Coll Pharmacy, Biosense Labs, Mol Light Technol Res, Hamilton Thorne Biosci, Elsevier Publishers, United States Geol Survey, BRD FL Integrated Sci Ctr DE resistance; genotoxicity; earl life-stages; hydrocarbons; metal-organic interactions; DNA-binding ID HUDSON RIVER; EXPRESSION; INDUCTION; EXPOSURE AB Atlantic tomcod (Microgadus tomcod) from the Hudson River (HR) are resistant at the molecular and organismic levels to the effects of exposure to dioxin-like aromatic hydrocarbon (AH) compounds, but much less so to benzo[a]pyrene (B[a]P). The aims of this study were to determine in early life-stages of tomcod exposed to B[a]P: (1) if DNA binding levels differed between fish from the HR and Miramichi River (MR), and (2) if co-exposure to chromium could modulate this genotoxic effect. After exposure to [H-3]B[a]P alone, DNA-bound radioactivity was 5-10-fold higher in embryos and larvae of MR than HR descent. Co-exposure to chromium modulated DNA binding levels in offspring of both populations. In MR embryos, co-exposure to chromium inhibited B[a]P uptake. These results demonstrated resistance to the genotoxic effects of B[a]P in early life stages of HR tomcod at an ecologically important endpoint and suggest the ability of chromium to modulate AH-induced genotoxicity. (C) 2004 Elsevier Ltd. All rights reserved. C1 NYU, Nelson Inst Environm Med, Sch Med, Tuxedo Pk, NY 10987 USA. Natl Marine Fisheries Serv, Howard Marine Sci Lab, Highlands, NJ 07732 USA. Fisheries & Oceans Canada, Gulf Fisheries Ctr, Moncton, NB E1C 9B6, Canada. RP Wirgin, I (reprint author), NYU, Nelson Inst Environm Med, Sch Med, 57 Old Forge Rd, Tuxedo Pk, NY 10987 USA. FU NIEHS NIH HHS [ES00260, ES10344] NR 9 TC 5 Z9 5 U1 1 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0141-1136 J9 MAR ENVIRON RES JI Mar. Environ. Res. PD AUG-DEC PY 2004 VL 58 IS 2-5 BP 383 EP 388 DI 10.1016/j.marenvres.2004.03.024 PG 6 WC Environmental Sciences; Marine & Freshwater Biology; Toxicology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Toxicology GA 831MS UT WOS:000222199100041 PM 15178057 ER PT J AU Wang, T Zhu, JZ Mackay, RA Chen, LQ Liu, ZK AF Wang, T Zhu, JZ Mackay, RA Chen, LQ Liu, ZK TI Modeling of lattice parameter in the Ni-Al system SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID THERMAL-EXPANSION COEFFICIENT; NICKEL-BASE SUPERALLOYS; X-RAY-DIFFRACTION; SOLID-SOLUTIONS; TEMPERATURE-DEPENDENCE; NEUTRON-DIFFRACTION; SELF-DIFFUSION; NI3AL ALLOYS; GAMMA-PHASE; ALUMINUM AB Considering the effects of temperature and composition, a phenomenological description of lattice parameters in solid states was developed. The lattice parameter of the pure element is modeled under the assumption of a linear temperature dependence of thermal expansion, while the lattice parameters of substitutional solid-solution phases are treated similar to the Gibbs-energy modeling in the CAL-PHAD (CALculation of PHAse Diagram) approach. Using this model, the lattice parameters of the gamma and gamma' phases in the Ni-Al system were analyzed and the model parameters were evaluated. The calculated lattice parameters and mismatches show good agreement with existing experimental data. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. NASA, Glenn Res Ctr, Div Mat, Cleveland, OH 44135 USA. RP Wang, T (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. EM taowang@psu.edu RI Chen, LongQing/I-7536-2012; Liu, Zi-Kui/A-8196-2009 OI Chen, LongQing/0000-0003-3359-3781; Liu, Zi-Kui/0000-0003-3346-3696 NR 77 TC 19 Z9 20 U1 1 U2 11 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD AUG PY 2004 VL 35A IS 8 BP 2313 EP 2321 DI 10.1007/s11661-006-0211-y PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 843HK UT WOS:000223069100014 ER PT J AU Schneider, JA Nunes, AC AF Schneider, JA Nunes, AC TI Characterization of plastic flow and resulting microtextures in a friction stir weld SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article ID VISUALIZATION; ALUMINUM AB In friction stir welding (FSW), a rotating threaded pin tool is inserted into a weld seam and literally stirs the edges of the seam together. The dynamically recrystallized zone (DXZ) of a polished and etched FSW cross section exhibits contrasting bands (the "onion-ring" structure), the origins of which are unclear. An orientation image mapping (OIM) study suggests that the bands may correspond, respectively, to a "straight-through" current of metal bypassing the pin tool in a single rotation or less and a "maelstrom" current rotating a number of times around the pin tool. C1 Mississippi State Univ, Dept Mech Engn, Mississippi State, MS 39762 USA. NASA, George C Marshall Space Flight Ctr, Mat Proc & Mfg Dept, Huntsville, AL 35812 USA. RP Schneider, JA (reprint author), Mississippi State Univ, Dept Mech Engn, Mississippi State, MS 39762 USA. EM schneider@me.msstate.edu NR 14 TC 119 Z9 125 U1 6 U2 33 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD AUG PY 2004 VL 35 IS 4 BP 777 EP 783 DI 10.1007/s11663-004-0018-4 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 841OH UT WOS:000222939500018 ER PT J AU Connors, M Veillet, C Brasser, R Wiegert, P Chodas, P Mikkola, S Innanen, K AF Connors, M Veillet, C Brasser, R Wiegert, P Chodas, P Mikkola, S Innanen, K TI Discovery of earth's quasi-satellite SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID ASTEROIDS AB The newly discovered asteroid 2003 YN107 is currently a quasi-satellite of the Earth, making a satellite-like orbit of high inclination with apparent period of one year. The term quasi-satellite is used since these large orbits are not completely closed, but rather perturbed portions of the asteroid's orbit around the Sun. Due to its extremely Earth-like orbit, this asteroid is influenced by Earth's gravity to remain within 0.1 AU of the Earth for approximately 10 years (1997 to 2006). Prior to this, it had been on a horseshoe orbit closely following Earth's orbit for several hundred years. It will re-enter such an orbit, and make one final libration of 123 years, after which it will have a close interaction with the Earth and transition to a circulating orbit. Chaotic effects limit our ability to determine the origin or fate of this object. C1 Athabasca Univ, Athabasca, AB T9S 3A3, Canada. Canada France Hawaii Telescope, Kamuela, HI 96743 USA. York Univ, Dept Phys & Astron, Toronto, ON M3J 1P3, Canada. Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Turku Univ Observ, FIN-21500 Piikkio, Finland. RP Connors, M (reprint author), Athabasca Univ, Athabasca, AB T9S 3A3, Canada. EM martinc@athabascau.ca NR 20 TC 24 Z9 24 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD AUG PY 2004 VL 39 IS 8 BP 1251 EP 1255 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 849WD UT WOS:000223571200001 ER PT J AU Sunshine, JM Bus, SJ McCoy, TJ Burbine, TH Corrigan, CM Binzel, RP AF Sunshine, JM Bus, SJ McCoy, TJ Burbine, TH Corrigan, CM Binzel, RP TI High-calcium pyroxene as an indicator of igneous differentiation in asteroids and meteorites SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID OUTER MAIN BELT; REFLECTANCE SPECTRA; SPECTROSCOPIC SURVEY; ORDINARY CHONDRITES; LASER IRRADIATION; ABSORPTION-BANDS; IRON-METEORITES; PARENT BODY; OLIVINE; MINERALOGY AB Our analyses of high quality spectra of several S-type asteroids (17 Thetis, 847 Agnia, 808 Merxia, and members of the Agnia and Merxia families) reveal that they include both low- and high-calcium pyroxene with minor amounts of olivine (<20%). In addition, we find that these asteroids have ratios of high-calcium pyroxene to total pyroxene of >similar to0.4. High-calcium pyroxene is a spectrally detectable and petrologically important indicator of igneous history and may prove critical in future studies aimed at understanding the history of asteroidal bodies. The silicate mineralogy inferred for Thetis and the Merxia and Agnia family members requires that these asteroids experienced igneous differentiation, producing broadly basaltic surface lithologies. Together with 4 Vesta (and its smaller "Vestoid" family members) and the main-belt asteroid 1489 Magnya, these new asteroids provide strong evidence for igneous differentiation of at least five asteroid parent bodies. Based on this analysis of a small subset of the near-infrared asteroid spectra taken to date with SpeX at the NASA IRTF, we expect that the number of known differentiated asteroids will increase, consistent with the large number of parent bodies inferred from studies of iron meteorites. C1 Sci Applicat Int Corp, Adv Technol Applicat Div, Chantilly, VA USA. Univ Hawaii, Inst Astron, Hilo, HI 96720 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. RP Sunshine, JM (reprint author), Sci Applicat Int Corp, Adv Technol Applicat Div, Chantilly, VA USA. EM sunshinej@saic.com NR 76 TC 64 Z9 64 U1 1 U2 2 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 AUG PY 2004 VL 39 IS 8 BP 1343 EP 1357 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 849WD UT WOS:000223571200007 ER PT J AU Floss, C Sandford, S Zinner, E AF Floss, C Sandford, S Zinner, E TI Robert M. Walker, 1929-2004 SO METEORITICS & PLANETARY SCIENCE LA English DT Biographical-Item C1 Washington Univ, Space Sci Lab, St Louis, MO 63130 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Floss, C (reprint author), Washington Univ, Space Sci Lab, 1 Brookings Dr, St Louis, MO 63130 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 BP 1409 EP 1411 PG 3 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 849WD UT WOS:000223571200012 ER PT J AU Burbine, TH McCoy, TJ Sunshine, JM Rivkin, AS Binzel, RP Bus, SJ AF Burbine, TH McCoy, TJ Sunshine, JM Rivkin, AS Binzel, RP Bus, SJ TI Near-infrared spectroscopy of vestoids SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc ID VESTA; METEORITES; ORIGIN C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. Sci Applicat Int Corp, Chantilly, VA 20151 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Univ Hawaii, Inst Astron, Hilo, HI 96720 USA. EM tburbine@lepvax.gsfc.nasa.gov NR 8 TC 0 Z9 0 U1 1 U2 2 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 AUG PY 2004 VL 39 IS 8 SU S BP A19 EP A19 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600022 ER PT J AU Cloutis, EA Hudon, P AF Cloutis, EA Hudon, P TI Reflectance spectra of selected carbonaceous chondrites SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc ID ASTEROIDS C1 Univ Winnipeg, Dept Geog, Winnipeg, MB R3B 2E9, Canada. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM e.cloutis@uwinnipeg.ca NR 5 TC 0 Z9 0 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD AUG PY 2004 VL 39 IS 8 SU S BP A23 EP A23 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600029 ER PT J AU Flynn, GJ Keller, LP Sutton, SR AF Flynn, GJ Keller, LP Sutton, SR TI Element hosts in anhydrous IDPS: A test of nebula condensation models SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 SUNY Coll Plattsburgh, Dept Phys, Plattsburgh, NY 12901 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Chicago, CARS, Chicago, IL 60637 USA. EM george.flynn@plattsburgh.edu NR 2 TC 0 Z9 0 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A40 EP A40 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600063 ER PT J AU Funaki, M Zolensky, M Imae, N AF Funaki, M Zolensky, M Imae, N TI The natural remanent magnetization and magnetic minerals of Tagish Lake (CI2) SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 Natl Inst Polar Res, Tokyo 173, Japan. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM funaki@nipr.ac.jp NR 3 TC 0 Z9 0 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A43 EP A43 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600069 ER PT J AU Hudon, P Mittlefehldt, DW AF Hudon, P Mittlefehldt, DW TI Ureilite geochemistry and smelting SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM pierre.hudon1@nasa.gov NR 3 TC 2 Z9 2 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A48 EP A48 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600079 ER PT J AU Keller, LP Messenger, S AF Keller, LP Messenger, S TI On the origin of GEMS II: Spectrum imaging of gems grains in interplanetary dust particles SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A52 EP A52 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600088 ER PT J AU Koizumi, E Mikouchi, T Miyamoto, M Monkawa, A Chokai, J McKay, G AF Koizumi, E Mikouchi, T Miyamoto, M Monkawa, A Chokai, J McKay, G TI Cooling rate of olivine megacryst in the Yamato-980459 olivine phyric shergottite SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 Univ Tokyo, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM koi@eps.s.u-tokyo.ac.jp NR 6 TC 1 Z9 1 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD AUG PY 2004 VL 39 IS 8 SU S BP A54 EP A54 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600092 ER PT J AU Messenger, S Keller, LP AF Messenger, S Keller, LP TI A supernova silicate from a cluster IDP SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc ID INTERPLANETARY DUST; GRAPHITE GRAINS; CHONDRITES; ORIGINS; SPINEL; STARS C1 NASA, ARES, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM scott.r.messenger@nasa.gov NR 11 TC 1 Z9 1 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A68 EP A68 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600119 ER PT J AU Mittlefehldt, DW Hudon, P AF Mittlefehldt, DW Hudon, P TI Northwest Africa 1500: Not a basaltic ureilite; Not even a ureilite SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM david.w.mittlefehldt@nasa.gov NR 5 TC 6 Z9 6 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A69 EP A69 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600122 ER PT J AU Nakamura, K Keller, LP Flynn, GJ Wirick, S AF Nakamura, K Keller, LP Flynn, GJ Wirick, S TI FTIR, XANES spectroscopy, and electron microscopic analysis of hydrated IDPs SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc ID INTERPLANETARY DUST PARTICLES; ORGANIC-MATTER C1 NASA, ARES, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. SUNY Coll Plattsburgh, Dept Phys, Plattsburgh, NY 12901 USA. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. EM keiko.nakamura1@jsc.nasa.gov NR 5 TC 0 Z9 0 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A75 EP A75 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600134 ER PT J AU Nuth, JA Ferguson, FT Johnson, NM AF Nuth, JA Ferguson, FT Johnson, NM TI Thermogravimetric measurement of the vapor pressure of silicon monoxide from 1300 K to 1773 K using an alumina effusion cell SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc ID THERMODYNAMIC PROPERTIES C1 NASA, Astrochem Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA. EM nuth@gsfc.nasa.gov RI Ferguson, Frank/C-9493-2012; Johnson, Natasha/E-3093-2012 NR 9 TC 0 Z9 0 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A80 EP A80 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600143 ER PT J AU Righter, K Campbell, AJ Humayun, M Drake, MJ AF Righter, K Campbell, AJ Humayun, M Drake, MJ TI Metal-silicate partitioning of volatile, siderophile elements: New results for Sb and As SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc ID CORE FORMATION; CONSTRAINTS; MELTS; EARTH C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. EM kevin.righter-1@nasa.gov NR 8 TC 1 Z9 1 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A89 EP A89 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600161 ER PT J AU Rodionov, D Schroder, C Klingelhofer, G Morris, RV Bernhardt, B de Souza, PA Yen, A Renz, F Wdowiak, T Squyres, SW AF Rodionov, D Schroder, C Klingelhofer, G Morris, RV Bernhardt, B de Souza, PA Yen, A Renz, F Wdowiak, T Squyres, SW CA Athena Sci Team TI Mossbauer investigation of "Bounce Rock" at Meridiani Planum on Mars - Indications for the first shergottite on Mars SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 Univ Mainz, Inst Anorgan & Analyt Chem, D-6500 Mainz, Germany. Space Res Inst IKI, Moscow, Russia. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. CVRD Grp, Vitoria, Brazil. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Alabama, Birmingham, AL USA. Cornell Univ, Ithaca, NY USA. EM klingel@mail.uni-mainz.de RI de Souza, Paulo/B-8961-2008; Schroder, Christian/B-3870-2009 OI de Souza, Paulo/0000-0002-0091-8925; Schroder, Christian/0000-0002-7935-6039 NR 3 TC 4 Z9 4 U1 0 U2 2 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 AUG PY 2004 VL 39 IS 8 SU S BP A91 EP A91 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600166 ER PT J AU Russell, SS Folco, L Grady, MM Zolensky, ME Jones, R Righter, K Zipfel, J Grossman, JN AF Russell, SS Folco, L Grady, MM Zolensky, ME Jones, R Righter, K Zipfel, J Grossman, JN TI The Meteoritical Bulletin, No. 88, 2004 July SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID ORDINARY CHONDRITES; IRON-METEORITES; CLASSIFICATION AB The Meteoritical Bulletin No. 88 lists information for 1610 newly classified meteorites, comprising 753 from Antarctica, 302 from Africa, 505 from Asia (495 of which are from Oman), 40 from North America, 5 from South America, 4 from Europe, and 1 of unknown origin. Information is provided for 9 falls (Alby sir Cheran, Al Zarnkh, Devgaon, Kamioka, Kendrapara, Maromandia, New Orleans, Sivas, and Villalbeto de la Pena). Noteworthy specimens include a eucrite fall (Alby sir Cheran), 6 martian meteorites, 13 lunar meteorites, and 12 irons including one weighing 3 metric tons (Dronino). C1 Nat Hist Museum, Dept Mineral, London SW7 5BD, England. Museo Nazl Antartide, I-53100 Siena, Italy. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ New Mexico, Inst Meteorit, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Max Planck Inst Chem, D-55020 Mainz, Germany. US Geol Survey, Reston, VA 20192 USA. RP Russell, SS (reprint author), Nat Hist Museum, Dept Mineral, Cromwell Rd, London SW7 5BD, England. EM sara.russell@nhm.ac.uk NR 12 TC 62 Z9 63 U1 5 U2 12 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 AUG PY 2004 VL 39 IS 8 SU S BP A215 EP A272 PG 58 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600234 ER PT J AU Wirick, S Flynn, GJ Keller, LP Jacobsen, C AF Wirick, S Flynn, GJ Keller, LP Jacobsen, C TI Nitrogen-mapping and nitrogen-xanes spectroscopy of interplanetary dust particles SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. SUNY Coll Plattsburgh, Dept Phys, Plattsburgh, NY 12901 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM swirick@bnl.gov RI Jacobsen, Chris/E-2827-2015 OI Jacobsen, Chris/0000-0001-8562-0353 NR 2 TC 0 Z9 0 U1 0 U2 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A114 EP A114 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600211 ER PT J AU Zipfel, J Anderson, R Bruckner, J Clark, BC Dreibus, G Economou, T Gellert, R Klingelhofer, G Lugmair, GW Ming, D Rieder, R Squyres, SW d'Uston, C Wanke, H Yen, A AF Zipfel, J Anderson, R Bruckner, J Clark, BC Dreibus, G Economou, T Gellert, R Klingelhofer, G Lugmair, GW Ming, D Rieder, R Squyres, SW d'Uston, C Wanke, H Yen, A CA Athena Sci Team TI APXS analyses of bounce rock - The first shergottite on Mars SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 MPI Chem, Mainz, Germany. JPL, Pasadena, CA USA. Lockheed Martin, Littleton, CO USA. Univ Chicago, Enrico Fermi Inst, LASR, Chicago, IL 60637 USA. Univ Mainz, D-6500 Mainz, Germany. JSC, Houston, TX USA. Cornell Univ, Ithaca, NY USA. CESR, Toulouse, France. EM zipfel@mpch-mainz.mpg.de NR 4 TC 12 Z9 12 U1 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A118 EP A118 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600219 ER PT J AU Zolensky, M Bodnar, R Tsuchiyama, A Okudaira, K Noguchi, T Uesugi, K Nakano, T AF Zolensky, M Bodnar, R Tsuchiyama, A Okudaira, K Noguchi, T Uesugi, K Nakano, T TI Fluid inclusions in chondrites SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract CT 67th Annual Meeting of the Meteoritical-Society CY AUG 02-06, 2004 CL Rio de Janeiro, BRAZIL SP Meteorit Soc C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Virginia Polytech Univ, Dept Geosci, Blacksburg, VA 24061 USA. Osaka Univ, Dept Earth & Space Sci, Toyonaka, Osaka 5600043, Japan. Ibaraki Univ, Dept Biol & Mat Sci, Ibaraki 3168511, Japan. JASRI, Spring 8, Sayo, Hyogo, Japan. Geol Survey Japan, Tsukuba, Ibaraki 3058567, Japan. EM michael.e.zolensky@nasa.gov RI Bodnar, Robert/A-1916-2009 NR 2 TC 2 Z9 2 U1 0 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 AUG PY 2004 VL 39 IS 8 SU S BP A118 EP A118 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 842GB UT WOS:000222990600220 ER PT J AU Rodgers, SD Charnley, SB AF Rodgers, SD Charnley, SB TI Interstellar diazenylium recombination and nitrogen isotopic fractionation SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE astrochemistry; molecular processes; ISM : molecules ID POLYCYCLIC AROMATIC-HYDROCARBONS; CLOUDS; CHEMISTRY; TRANSITION; MOLECULES; ORIGIN; COMETS; N2H+ AB In an earlier paper (Charnley & Rodgers), we demonstrated that gas-phase chemistry in selectively depleted interstellar cores and/or protostellar discs can lead to significant N-15 enhancements. Recent laboratory measurements of the electron dissociative recombination of N-2 H+ show that this reaction is able to break the N-N bond and so will release nitrogen atoms and NH radicals into the gas at a much faster rate than previous models have assumed. We have assessed the importance of this new result for the N-15 chemistry and find that the reaction acts to reduce the degree of N-15 enhancement. We discuss two modifications to our original model that each allow the high N-15/N-14 ratios to be recovered: N-2 H+ recombination on polycyclic aromatic hydrocarbon (PAH) molecules and a small barrier in the N + NH reaction. We find that higher N-15/N-14 ratios can be produced in this revised model. Some observational consequences of these are outlined. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Rodgers, SD (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. EM rodgers@dusty.arc.nasa.gov RI Charnley, Steven/C-9538-2012 NR 24 TC 25 Z9 25 U1 0 U2 2 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD AUG 1 PY 2004 VL 352 IS 2 BP 600 EP 604 DI 10.1111/j.1365-2966.2004.07953.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 839YY UT WOS:000222822500024 ER PT J AU Burgett, WS Vick, MM Davis, DS Colless, M De Propris, R Baldry, I Baugh, C Bland-Hawthorn, J Bridges, T Cannon, R Cole, S Collins, C Couch, W Cross, N Dalton, G Driver, S Efstathiou, G Ellis, R Frenk, CS Glazebrook, K Hawkins, E Jackson, C Lahav, O Lewis, I Lumsden, S Maddox, S Madgwick, D Norberg, P Peacock, JA Percival, W Peterson, B Sutherland, W Taylor, K AF Burgett, WS Vick, MM Davis, DS Colless, M De Propris, R Baldry, I Baugh, C Bland-Hawthorn, J Bridges, T Cannon, R Cole, S Collins, C Couch, W Cross, N Dalton, G Driver, S Efstathiou, G Ellis, R Frenk, CS Glazebrook, K Hawkins, E Jackson, C Lahav, O Lewis, I Lumsden, S Maddox, S Madgwick, D Norberg, P Peacock, JA Percival, W Peterson, B Sutherland, W Taylor, K TI Substructure analysis of selected low-richness 2dFGRS clusters of galaxies SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : clusters : general; large-scale structure of Universe ID X-RAY; REDSHIFT SURVEY; SUBCLUSTER MERGERS; OPTICAL ANALYSIS; COMA CLUSTER; CATALOG; DYNAMICS; SEGREGATION; COMPONENTS; APM AB Complementary one-, two- and three-dimensional tests for detecting the presence of substructure in clusters of galaxies are applied to recently obtained data from the 2dF Galaxy Redshift Survey. The sample of 25 clusters used in this study includes 16 clusters not previously investigated for substructure. Substructure is detected at or greater than the 99 per cent confidence level in at least one test for 21 of the 25 clusters studied here. From the results, it appears that low-richness clusters commonly contain subclusters participating in mergers. About half of the clusters have two or more components within 0.5 h(-1) Mpc of the cluster centroid, and at least three clusters (Abell 1139, Abell 1663 and Abell S333) exhibit velocity-position characteristics consistent with the presence of possible cluster rotation, shear, or infall dynamics. The geometry of certain features is consistent with influence by the host supercluster environments. In general, our results support the hypothesis that low-richness clusters relax to structureless equilibrium states on very long dynamical time-scales (if at all). C1 Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Texas, Dept Phys, Richardson, TX 75083 USA. UMBC, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Lab High Energy Astrophys, Greenbelt, MD 20771 USA. Anglo Australian Observ, Epping, NSW 2121, Australia. Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Durham, Dept Phys, Durham DH1 3LE, England. Queens Univ, Dept Phys, Kingston, ON K7L 3N6, Canada. Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead L14 1LD, Merseyside, England. Univ New S Wales, Dept Astrophys, Sydney, NSW 2052, Australia. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England. CSIRO Australia Telescope Natl Facil, Epping, NSW 1710, Australia. Univ Leeds, Dept Phys, Leeds LS2 9JT, W Yorkshire, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. ETH Honggerberg, ETHZ Inst Astron, CH-8093 Zurich, Switzerland. Univ Edinburgh, Royal Observ, Inst Astron, Edinburgh EH9 3HJ, Midlothian, Scotland. RP Burgett, WS (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. EM burgett@ifa.hawaii.edu RI Baugh, Carlton/A-8482-2012; Jackson, Carole/K-1648-2013; Driver, Simon/H-9115-2014; Glazebrook, Karl/N-3488-2015; OI Colless, Matthew/0000-0001-9552-8075; Baldry, Ivan/0000-0003-0719-9385; Baugh, Carlton/0000-0002-9935-9755; Jackson, Carole/0000-0002-7089-8827; Driver, Simon/0000-0001-9491-7327; Glazebrook, Karl/0000-0002-3254-9044; Maddox, Stephen/0000-0001-5549-195X; Hawkins, Ed/0000-0001-9477-3677 NR 52 TC 39 Z9 39 U1 0 U2 3 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD AUG 1 PY 2004 VL 352 IS 2 BP 605 EP 654 DI 10.1111/j.1365-2966.2004.07952.x PG 50 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 839YY UT WOS:000222822500025 ER PT J AU Hou, AY Zhang, SQ Reale, O AF Hou, AY Zhang, SQ Reale, O TI Variational continuous assimilation of TMI and SSM/I rain rates: Impact on GEOS-3 hurricane analyses and forecasts SO MONTHLY WEATHER REVIEW LA English DT Article ID PASSIVE MICROWAVE SENSORS; MOISTURE OBSERVATIONS; PRECIPITATION DATA; PARAMETERIZATION; PROFILES; MODELS; WATER; CLOUD AB This study describes a 1D variational continuous assimilation (VCA) algorithm for assimilating tropical rainfall data using moisture/temperature time-tendency corrections as the control variable to offset model deficiencies. For rainfall assimilation, model errors are of special concern since model-predicted precipitation is based on parameterized moist physics, which can have substantial systematic errors. The authors examine whether a VCA scheme using the forecast model as a weak constraint offers an effective pathway to precipitation assimilation. The particular scheme investigated employs a precipitation observation operator based on a 6-h integration of a column model of moist physics from the Goddard Earth Observing System (GEOS) global data assimilation system (DAS). In earlier studies, a simplified version of this scheme was tested, and improved monthly mean analyses and better short-range forecast skills were obtained. This paper describes the full implementation of the 1DVCA scheme using background and observation error statistics and examines its impact on GEOS analyses and forecasts of prominent tropical weather systems such as hurricanes. Assimilation experiments with and without rainfall data for Hurricanes Bonnie and Floyd show that assimilating 6-h Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Special Sensor Microwave Imager (SSM/I) surface rain accumulations leads to more realistic analyzed storm features and better 5-day storm track prediction and precipitation forecasts. These results demonstrate the importance of addressing model deficiencies in moisture time tendency in order to make effective use of precipitation information in data assimilation. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Sci Applicat Int Corp, Beltsville, MD USA. Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA. RP Hou, AY (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 900-3, Greenbelt, MD 20771 USA. EM arthur.y.hou@nasa.gov RI Hou, Arthur/D-8578-2012 NR 32 TC 37 Z9 39 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 AUG PY 2004 VL 132 IS 8 BP 2094 EP 2109 DI 10.1175/1520-0493(2004)132<2094:VCAOTA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 845DG UT WOS:000223215400013 ER PT J AU Haskell, RE Lee, C Hanna, DM AF Haskell, RE Lee, C Hanna, DM TI Geno-fuzzy classification trees SO PATTERN RECOGNITION LA English DT Article DE genetic; fuzzy; decision tree; classification; fuzzy weights ID DECISION TREES; CLASSIFIERS; ALGORITHM AB Making the non-terminal nodes of a binary tree classifier fuzzy can mitigate tree brittleness. Using a genetic algorithm, two optimization techniques are explored. In one case, each generation minimizes classification error by optimizing a common fuzzy percent, p(T), used to determine parameters at every node. In the other case, each generation yields a sequence of minimized node-specific parameters. The output value is determined through defuzzification after input vectors, in general, take both paths at each node with a weighting factor determined by the node membership functions. Experiments conducted using this geno-fuzzy approach yield an improvement compared with other classical algorithms. (C) 2004 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved. C1 Oakland Univ, CSE Dept, Rochester, MI 48309 USA. NASA, Ames Res Ctr, SAIC, Moffett Field, CA 94035 USA. Oakland Univ, Rochester, MI 48309 USA. RP Hanna, DM (reprint author), Oakland Univ, CSE Dept, Rochester, MI 48309 USA. EM dmhanna@oakland.edu NR 28 TC 2 Z9 2 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0031-3203 J9 PATTERN RECOGN JI Pattern Recognit. PD AUG PY 2004 VL 37 IS 8 BP 1653 EP 1659 DI 10.1016/j.patcog.2004.01.010 PG 7 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 832RO UT WOS:000222284800007 ER PT J AU Post, RB Welch, RB AF Post, RB Welch, RB TI Studies of open-loop pointing in the presence of induced SO PERCEPTION & PSYCHOPHYSICS LA English DT Article ID EYE-HAND COORDINATION; INDUCED-MOTION; VISUAL SPACE; SPATIAL LOCALIZATION; PERCEPTION; INFORMATION; ILLUSION; MOVEMENTS; ADAPTATION; POSITION AB In the present research, we examined the influence of induced motion (IM) on open-loop pointing responses and the possibility that IM alters the registration of either eye or trunk position. In two experiments, subjects tracked a dot that oscillated vertically while a rectangular stimulus oscillated horizontally. The pairing of frame and dot motion caused the dot to appear to move on a slant, due to IM. In the first experiment, the subjects made judgments of the apparent slant of the dot's motion and, on separate trials, pointed open loop at the apparent location of the dot at the endpoints of its motion. Both responses were influenced by IM, although the effect on dot localization was less than the amount predicted by the IM, as indicated by the slant responses. Results were similar immediately following IM and after a 5-sec delay. In the second experiment, the subjects pointed open loop either at the apparent location of the endpoints of the tracked dot's motion or at the apparent location of one of three other briefly flashed stationary dots. The pointing responses directed toward the fixated IM target were influenced by IM to a greater extent than the responses directed toward the stationary dots. The results of the two experiments are inconsistent with the hypothesis that the effect of IM on open-loop pointing at the IM target results completely from altered perception of either eye or trunk position, since misregistration of either would be expected to influence, in a similar fashion, pointing at both the tracked dot and the briefly flashed, stationary targets. C1 Univ Calif Davis, Dept Psychol, Davis, CA 95616 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Post, RB (reprint author), Univ Calif Davis, Dept Psychol, Davis, CA 95616 USA. EM rbpost@ucdavis.edu NR 51 TC 1 Z9 1 U1 1 U2 1 PU PSYCHONOMIC SOC INC PI AUSTIN PA 1710 FORTVIEW RD, AUSTIN, TX 78704 USA SN 0031-5117 J9 PERCEPT PSYCHOPHYS JI Percept. Psychophys. PD AUG PY 2004 VL 66 IS 6 BP 1045 EP 1055 DI 10.3758/BF03194994 PG 11 WC Psychology; Psychology, Experimental SC Psychology GA 881MJ UT WOS:000225871300012 PM 15675650 ER PT J AU Carroll, SM Duvvuri, V Trodden, M Turner, MS AF Carroll, SM Duvvuri, V Trodden, M Turner, MS TI Is cosmic speed-up due to new gravitational physics? SO PHYSICAL REVIEW D LA English DT Article ID PROBE WMAP OBSERVATIONS; ANGULAR POWER SPECTRUM; HIGHER-ORDER GRAVITY; COSMOLOGICAL CONSEQUENCES; SCALAR FIELD; SUPERNOVAE; INFLATION; UNIVERSE; MODELS; LAMBDA AB We show that cosmic acceleration can arise due to very tiny corrections to the usual gravitational action of general relativity, of the form R-n with n>0. This model eliminates the need for a nonzero cosmological constant or any other form of dark energy, attributing a purely gravitational origin to the acceleration of the universe. C1 Univ Chicago, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. Syracuse Univ, Dept Phys, Syracuse, NY 13244 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Chicago, Ctr Cosmol Phys, Chicago, IL 60637 USA. RP Univ Chicago, Enrico Fermi Inst, Dept Phys, 5640 S Ellis Ave, Chicago, IL 60637 USA. OI Trodden, Mark/0000-0001-6864-6711 NR 31 TC 1203 Z9 1207 U1 7 U2 39 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 AUG PY 2004 VL 70 IS 4 AR 043528 DI 10.1103/PhysRevD.70.043528 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 853WK UT WOS:000223859700049 ER PT J AU Kazanas, D Mohapatra, RN Nasri, S Teplitz, VL AF Kazanas, D Mohapatra, RN Nasri, S Teplitz, VL TI Neutrino mass, dark matter, and inflation SO PHYSICAL REVIEW D LA English DT Article ID BARYOGENESIS; OSCILLATIONS; CPT AB We show that spontaneous breaking of global B-L symmetry responsible for small neutrino masses via the seesaw mechanism provides a unified picture of hybrid inflation and dark matter if the scale of B-L breaking is close to the GUT scale. The Majoron, which acquires a small mass due to Planck scale breaking of B-L, is the dark matter candidate. The coupling of the Majoron field to the neutrino induces a small violation of CPT and Lorentz invariance at the present epoch. We discuss some of the phenomenological and cosmological implications of the model. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. So Methodist Univ, Dept Phys, Dallas, TX 75275 USA. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Nasri, Salah/F-4752-2013 NR 28 TC 8 Z9 8 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 AUG PY 2004 VL 70 IS 3 AR 033015 DI 10.1103/PhysRevD.70.033015 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 853WJ UT WOS:000223859600027 ER PT J AU Guo, BY Holder, DW Carter, L AF Guo, BY Holder, DW Carter, L TI Distribution of flowing fluids in a confined porous medium under microgravity conditions SO PHYSICS OF FLUIDS LA English DT Article ID PERCOLATION AB Predicting distribution of flowing fluids in confined porous media under microgravity conditions is vitally important for optimal design of packed bubble column reactors in space stations. Existing correlations have been found inaccurate when applied to microgravity conditions. On the basis of Darcy's law for two-phase flow, a simple mathematical model has been developed in this study. Sensitivity analyses with the model indicate that for a given combination of wetting and nonwetting fluid flow rates, fluid holdups are controlled by relative permeabilities. The effect of gravity on fluid holdup is influenced by the absolute permeability of the porous medium. Fluid distribution is affected by the temperature-dependent fluid properties and wall effect. (C) 2004 American Institute of Physics. C1 Univ SW Louisiana, Dept Petr Engn, Lafayette, LA 70504 USA. NASA, George C Marshall Space Flight Ctr, Flight Project Directorate FD21, Huntsville, AL 35812 USA. RP Guo, BY (reprint author), Univ SW Louisiana, Dept Petr Engn, Lafayette, LA 70504 USA. EM boyun.guo@louisiana.edu; donald.w.holder@nasa.gov NR 9 TC 2 Z9 2 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 J9 PHYS FLUIDS JI Phys. Fluids PD AUG PY 2004 VL 16 IS 8 BP 3045 EP 3050 DI 10.1063/1.1768551 PG 6 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 836AY UT WOS:000222528300027 ER PT J AU Balasubramaniam, R Subramanian, RS AF Balasubramaniam, R Subramanian, RS TI Thermocapillary convection due to a stationary bubble SO PHYSICS OF FLUIDS LA English DT Article ID VERTICAL TEMPERATURE-GRADIENT; TENSION DRIVEN FLOW; HEMISPHERICAL BUBBLE; HEATED WALL; MICROGRAVITY; MOTION; FIELDS AB We analyze the velocity and temperature fields due to thermocapillary convection around a gas bubble that is stationary in a liquid. A linear temperature field is imposed in the undisturbed liquid. Our interest is in the effect of convective transport of momentum and energy on the velocity and temperature fields. We assume that buoyant convection is negligible. The relevant Reynolds and Marangoni numbers are assumed to be small compared with unity. When the Reynolds and Marangoni numbers are set equal to zero, the steady velocity field far from the bubble decays inversely with distance from it. We show that this behavior of the velocity field, coupled with the linear variation of the imposed temperature far away from the bubble, leads to an ill-posedness in the problem for the perturbation temperature field at steady state for small Marangoni numbers, when the Reynolds number is zero. We also consider the effect of convective transport of momentum for small Reynolds number, when the Marangoni number is zero. In this case, the velocity field far away from the bubble decays inversely as the distance from the bubble even in the presence of inertia. It follows that, for a fixed Prandtl number, when both the Marangoni and Reynolds number are nonzero, the behavior of the velocity field far from the bubble continues to yield an ill-posed problem for the steady perturbation temperature field. Therefore, inertia cannot relieve the ill-posedness of the perturbation problem for the steady temperature field. In order to understand the origin of this ill-posedness, we analyze a related problem involving the unsteady development of the temperature field in the liquid from the moment that a point force is applied to it, and held constant subsequently. We show that including the effect of convective transport of energy by a perturbation expansion leads to a temperature field in the liquid that is always time dependent. The temperature field never achieves a steady state. (C) 2004 American Institute of Physics. C1 NASA, Lewis Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Cleveland, OH 44135 USA. Clarkson Univ, Potsdam, NY 13699 USA. RP Balasubramaniam, R (reprint author), NASA, Lewis Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Cleveland, OH 44135 USA. EM bala@grc.nasa.gov NR 20 TC 11 Z9 11 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD AUG PY 2004 VL 16 IS 8 BP 3131 EP 3137 DI 10.1063/1.1768091 PG 7 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 836AY UT WOS:000222528300037 ER PT J AU Comiso, JC Parkinson, CL AF Comiso, JC Parkinson, CL TI Satellite-observed changes in the Arctic SO PHYSICS TODAY LA English DT Article ID SEA-ICE COVER; VARIABILITY; TEMPERATURE; BALANCE; TRENDS C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Comiso, JC (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Parkinson, Claire/E-1747-2012 OI Parkinson, Claire/0000-0001-6730-4197 NR 20 TC 94 Z9 96 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD AUG PY 2004 VL 57 IS 8 BP 38 EP 44 DI 10.1063/1.1801866 PG 7 WC Physics, Multidisciplinary SC Physics GA 842KS UT WOS:000223003600025 ER PT J AU Rahman, AM Gedevanishvili, A Bungo, MW Vijayakumar, V Chamoun, A Birnbaum, Y Schlegel, TT AF Rahman, AM Gedevanishvili, A Bungo, MW Vijayakumar, V Chamoun, A Birnbaum, Y Schlegel, TT TI Non-invasive detection of coronary artery disease by a newly developed high-frequency QRS electrocardiogram SO PHYSIOLOGICAL MEASUREMENT LA English DT Article; Proceedings Paper CT World Congress on Medical Physics and Biomedical Engineering CY AUG, 2003 CL Sydney, AUSTRALIA DE signal-averaged electrocardiography; reduced amplitude zone; myocardial perfusion imaging; kurtosis ID SIGNAL-AVERAGED ECG; MYOCARDIAL-ISCHEMIA; COMPONENTS; STANDARD; LEADS; INFARCTION; POPULATION AB Compared to other non-invasive methods, the conventional 12-lead electrocardiogram (ECG) has low sensitivity and specificity for identifying coronary artery disease (CAD). We compared the newly developed high-frequency QRS electrocardiogram (HFQRS ECG, 150-250 Hz) with adenosine sestamibi myocardial perfusion study (MPI)-the most sensitive non-invasive study in cardiology practice. Using advanced 12-lead computer-based ECG software recently developed at NASA, criteria for a positive 12-lead HFQRS-ECG test for obstructive CAD were developed using 300 signal-averaged beats from patients undergoing elective coronary angiograms for evaluation of chest pain. These criteria, which rely strictly upon the presence or the absence of morphologic 'reduced amplitude zones' (RAZs) and not upon the 'root mean squared' (RMS) voltage amplitudes of the HFQRS complexes, were then applied prospectively to 18 patients undergoing MPI. Active CAD was considered present when reversible ischemic defects were present on MPI. Of the 18 patients, 9 had reversible defects on MPI (positive scan), whereas the other 9 had no reversible perfusion defects (negative scan). Patients with a positive nuclear study went on to coronary angiography confirming CAD, except in one patient who had nonobstructive coronary disease ( < 50% stenosis). Eight of the 18 subjects therefore had active CAD, whereas 10 were judged not to have active CAD. The 12-lead HFQRS-ECG result was consistent with nuclear scan results in 14 of 18 patients. The HFQRS-ECG and nuclear results differed in: (1) one patient who had a low score positive MPI, negative HFQRS-ECG and normal coronary angiogram; (2) one patient who had a small reversible anterior wall perfusion defect, 60% LAD lesion on angiogram but a negative HF-QRS result; and (3) two individuals who had positive HFQRS-ECG results in the face of negative nuclear scans but who did not undergo angiography. 12-lead HFQRS ECG had excellent sensitivity (87.5% based on 7/8 true positives correctly identified) and specificity (no worse than 80%, > 8/10 true negatives correctly identified) for identifying CAD. 12-lead HFQRS ECG is an easily performed, inexpensive and potentially widely available technique that utilizes the same leads and electrodes as the conventional 12-lead ECG. It had accuracy comparable to MPI in this study. Resting 12-lead HFQRS ECG appears to be a very promising non-invasive technique for identifying CAD and may represent a viable alternative to many of the more expensive and time-consuming techniques presently utilized for non-invasively identifying CAD. C1 Univ Texas, Med Branch, Galveston, TX 77555 USA. Univ Texas, Houston Med Sch, Houston, TX USA. NASA, Johnson Space Ctr, Houston, TX USA. RP Rahman, AM (reprint author), Univ Texas, Med Branch, Galveston, TX 77555 USA. EM morahman@utmb.edu NR 19 TC 2 Z9 3 U1 2 U2 4 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 AUG PY 2004 VL 25 IS 4 BP 957 EP 965 AR PII S0967-3334(04)74202-1 DI 10.1088/0967-3334/25/4/014 PG 9 WC Biophysics; Engineering, Biomedical; Physiology SC Biophysics; Engineering; Physiology GA 849QW UT WOS:000223556600015 PM 15382834 ER PT J AU Kazeminejad, B Perez-Ayucar, M Lebreton, JP Sanchez-Nogales, M Bello-Mora, M Strange, N Roth, D Popken, L Clausen, K Couzin, P AF Kazeminejad, B Perez-Ayucar, M Lebreton, JP Sanchez-Nogales, M Bello-Mora, M Strange, N Roth, D Popken, L Clausen, K Couzin, P TI Simulation and analysis of the revised Huygens probe entry and descent trajectory and radio link modelling SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Cassini/Huveens mission; Huygens probe; relay link; mission analysis; entry and descent trajectory ID TITANS UPPER-ATMOSPHERE; SYSTEM-DESIGN; OCCULTATION; TEMPERATURE; MISSION; WINDS AB The Cassini spacecraft will arrive at Saturn in 2004 carrying the Huygens probe. The beginning of the Cassini tour at Saturn has been redesigned to achieve a different relative orbiter/probe geometry in order to compensate for the probe relay receiver design flaw that was discovered during tests in February 2000. This paper presents a numerical simulation of the Huygens atmospheric entry and descent trajectory and the Cassini flyby trajectory during the probe mission. A variety of parameters that are crucial for the probe system and its scientific payload have been calculated and analyzed together with an assessment of their uncertainties. Furthermore the orbiter/probe relay link was simulated in order to assess any potential data loss on the basis of an analytical model of the actual Huygens receiver onboard the Cassini spacecraft. The redesigned Cassini/Huygens mission satisfies all science and engineering requirements and assures the best possible radio link for the entire nominal mission duration. (C) 2004 Elsevier Ltd. All rights reserved. C1 Austrian Acad Sci, Dept Extraterr Phys, Space Res Inst, IWF, A-8042 Graz, Austria. ESA, Res & Sci Support Dept, ESTEC, NL-2200 AG Noordwijk, Netherlands. Deimos Space, Tres Cantos 28760, Spain. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. ESA, Sci Projects Dept, ESTEC, NL-2200 AG Noordwijk, Netherlands. Alcatel Space, F-06322 Cannes La Bocca, France. RP Kazeminejad, B (reprint author), Austrian Acad Sci, Dept Extraterr Phys, Space Res Inst, IWF, Schmeidlstr 6, A-8042 Graz, Austria. EM Bobby.Kazeminejad@rssd.esa.int NR 35 TC 8 Z9 8 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 AUG PY 2004 VL 52 IS 9 BP 799 EP 814 DI 10.1016/j.pss.2004.03.008 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838DQ UT WOS:000222694000003 ER PT J AU Khazanov, GV Krivorutsky, EN Liemohn, MW AF Khazanov, GV Krivorutsky, EN Liemohn, MW TI Nonlinear drift-kinetic equation in the presence of a circularly polarized wave SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 27th General Meeting of the European-Geophysical-Society CY APR, 2002 CL NICE, FRANCE SP European Geophys Soc ID WARM 2-FLUID PLASMA; PONDEROMOTIVE FORCE; GYROKINETIC THEORY; ACCELERATION; MODES; FIELD; IONS AB This paper presents a theoretical description of plasma motion in the presence of a circularly polarized wave of arbitrary frequency with its wave vector directed along the ambient magnetic field. Both the equations of motion for a single particle and the nonlinear kinetic equation in the drift approximation are given. The nonstationarity and inhomogeneity of the plasma-wave system are taken into account. The distribution function is expressed with the help of initial, non-averaged variables, which is a transformation that greatly simplifies the calculation of the moments. The time-dependent part of the ponderomotive force is discussed, and it is shown that this component can be on the order of the other terms in the particle motion equation. The examples, of ion acceleration in the auroral zone and the effects of lightning discharge are discussed to show that this theoretical study has applications to near-Earth space plasmas. Published by Elsevier Ltd. C1 NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35805 USA. Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. RP Khazanov, GV (reprint author), NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. RI Liemohn, Michael/H-8703-2012 OI Liemohn, Michael/0000-0002-7039-2631 NR 26 TC 2 Z9 3 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 AUG PY 2004 VL 52 IS 10 BP 945 EP 951 DI 10.1016/j.pss.2004.02.003 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 858UK UT WOS:000224217300007 ER PT J AU Allende, M Mohan, RV Walsh, SM AF Allende, M Mohan, RV Walsh, SM TI Experimental and numerical analysis of flow behavior in the FASTRAC liquid composite manufacturing process SO POLYMER COMPOSITES LA English DT Article ID MULTILAYER FIBER REINFORCEMENTS; PERMEABILITY CHARACTERISTICS; IMPREGNATION AB The success of resin infusion during liquid composite processing depends on several factors; including the complete impregnation of the dry performs, the processing conditions. and the tooling used during processing. New process developments based on the Fast Remotely Actuated Channels (FASTRAC) process aid the infusion with the creation of preferential resin flow paths using a non-contact tooling. Experiments to understand and study the infusion behavior with the presence of the FASTRAC non-contacting tooling have been performed, and compared with vacuum-assisted processes without such tooling. Experimental studies indicate that the infusion time with FASTRAC channel configurations is significantly less despite the additional volume regions to be infused during processing. The use of a non-contacting interchangeable tool, the improved infusion behavior, and the significant reduction in the infusion time provide significant advantages for processing advanced composite systems, including the potential to use high viscosity resin systems, and process automation. The process simulation models of the experimental configurations based on the thin shell model configurations have been compared with experimental observations. Studies indicate that the process simulation models and approaches employed clearly emulate the infusion behavior seen when the channels are present, validating the modeling strategies employed. Similar simulation approaches will thus be effective to study and understand various FASTRAC tooling configurations while processing complex composite structures. (C) 2004 Society of Plastics Engineers. C1 USA, Res Lab, Weapons & Mat Res Directorate, Aberdeen Proving Ground, MD 21005 USA. Univ New Orleans, Natl Ctr Adv Mfg, Dept Mech Engn, New Orleans, LA 70148 USA. RP Allende, M (reprint author), USA, Res Lab, Weapons & Mat Res Directorate, Aberdeen Proving Ground, MD 21005 USA. NR 26 TC 12 Z9 12 U1 0 U2 1 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0272-8397 J9 POLYM COMPOSITE JI Polym. Compos. PD AUG PY 2004 VL 25 IS 4 BP 384 EP 396 DI 10.1002/pc.20032 PG 13 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 847ZN UT WOS:000223436700005 ER PT J AU Kucuk, H Parker, GG Baumgartner, ET Klymyshyn, NA AF Kucuk, H Parker, GG Baumgartner, ET Klymyshyn, NA TI Desensitization of camera-aided manipulation to target specification errors SO PRESENCE-TELEOPERATORS AND VIRTUAL ENVIRONMENTS LA English DT Article ID SPACE MANIPULATION AB Applications of vision-based remotely operated robotic systems range from planetary exploration to hazardous waste remediation. For space applications, where communication time lags are large, the target selection and robot positioning tasks may be performed sequentially, differing from conventional telerobotic maneuvers. For these point-and-move systems, the desired target must be defined in the image plane of the cameras either by an operator or through image processing software. Ambiguity of the target specification will naturally lead to end-effector positioning errors. In this paper, the target specification error covariance is shown to transform linearly to the end-effector positioning error. In addition, a methodology for optimal estimation of camera-view parameters of a vision-based robotic system based on target specification errors is presented. The proposed strategy is based on minimizing the end-effector error covariance matrix. Experimental results are presented demonstrating an increase in end-effector positioning, compared to traditional view parameter estimation by up to 32%. C1 Nigde Univ, Aksaray Muhendisik Fak, TR-68100 Konya Yolu, Aksaray, Turkey. Michigan Technol Univ, Dept Mech Engn & Engn Mech, Houghton, MI 49931 USA. CALTECH, Jet Prop Lab, Mech & Robot Technol Grp, Sci & Technol Dev Sect, Pasadena, CA 91109 USA. Battelle Mem Inst, Pacific NW Lab, Richland, WA 99352 USA. RP Nigde Univ, Aksaray Muhendisik Fak, TR-68100 Konya Yolu, Aksaray, Turkey. EM hkucuk7@hotmail.com; ggparker@mtu.edu; eric.t.baumgartner@jpl.nasa.gov; nicholas.klymyshyn@pnl.gov NR 12 TC 0 Z9 0 U1 0 U2 0 PU MIT PRESS PI CAMBRIDGE PA ONE ROGERS ST, CAMBRIDGE, MA 02142-1209 USA SN 1054-7460 EI 1531-3263 J9 PRESENCE-TELEOP VIRT JI Presence-Teleoper. Virtual Env. PD AUG PY 2004 VL 13 IS 4 BP 385 EP 394 DI 10.1162/1054746041944795 PG 10 WC Computer Science, Cybernetics; Computer Science, Software Engineering SC Computer Science GA 855LT UT WOS:000223975500001 ER PT J AU Paavola, CD Chan, SL McMillan, RA Li, Y Trent, JD AF Paavola, CD Chan, SL McMillan, RA Li, Y Trent, JD TI Circular permutation of a chaperonin protein: Biophysics and application to nanotechnology SO PROTEIN SCIENCE LA English DT Meeting Abstract CT 18th Symposium of the Protein-Society CY AUG 14-18, 2004 CL San Diego, CA SP Protein Soc, Abbott Lab Fund, Amer Peptide Soc, Amgen, Biogen Idec, DARPA, Eli Lilly & Co, Eli Lilly Res Labs, Biotechnol Discovery Res, Genencor Int, Genentech Inc, Merck Res Labs, Natl Sci Fdn, NIH, New England BioLabs, Novartis Inst Biomed Res, Pfizer Inc, Protein Soc Educ Comm, Protein Soc Young Protein Sci Comm, Roche Pharmaceut, Sunesis Pharmaceut Inc C1 NASA, Ames Res Ctr, Bioengn Branch, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT PI WOODBURY PA 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2924 USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD AUG PY 2004 VL 13 SU 1 MA 151 BP 100 EP 100 PG 1 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 866TL UT WOS:000224796100152 ER PT J AU Arunajadai, SG Uder, SJ Stone, RB Tumer, IY AF Arunajadai, SG Uder, SJ Stone, RB Tumer, IY TI Failure mode identification through clustering analysis SO QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL LA English DT Article; Proceedings Paper CT 3rd International Conference of the European-Network-of-Business-and-Industrial-Statisticians CY AUG, 2003 CL Barcelona, SPAIN SP European Network Business & Ind Statisticians DE clustering algorithm; conceptual design failure-free design; failure mode; failure modes and effects analysis; function based design; product design; statistical based design AB Research has shown that nearly 80% of the costs and problems associated with product design are created during product development, and cost and quality are essentially designed into products during the conceptual design stage. Failure identification procedures (such as failure modes and effects analysis (FMEA), failure modes, effects and criticality analysis (FMECA) and fault tree analysis (FTA)) and design of experiments are currently being used for both quality control and for the detection of potential failure modes during the design stage or post-product launch. Although all of these methods have their own advantages, they do not provide the designer with an indication of the predominant failures that should receive considerable attention while the product is being designed. The work presented here proposes a statistical clustering procedure to identify potential failures in the conceptual design stage. A functional approach, which hypothesizes that similarities exist between different failure modes based on the functionality of the product/component, is employed to identify failure modes. The various steps of the methodology are illustrated using a hypothetical design example. Copyright (C) 2004 John Wiley Sons, Ltd. C1 Univ Missouri, Dept Basic Engn, Rolla, MO 65409 USA. Univ Missouri, Dept Mech Engn, Rolla, MO 65409 USA. Univ Missouri, Dept Elect Engn, Rolla, MO 65409 USA. NASA, Ames Res Ctr, Div Comp Sci, Moffett Field, CA 94035 USA. RP Stone, RB (reprint author), Univ Missouri, Dept Basic Engn, Rolla, MO 65409 USA. EM rstone@umr.edu NR 27 TC 13 Z9 16 U1 2 U2 5 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0748-8017 J9 QUAL RELIAB ENG INT JI Qual. Reliab. Eng. Int. PD AUG PY 2004 VL 20 IS 5 BP 511 EP 526 DI 10.1002/qre.663 PG 16 WC Engineering, Multidisciplinary; Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 846HC UT WOS:000223305500012 ER PT J AU Ma, N Song, G Lee, HJ AF Ma, N Song, G Lee, HJ TI Position control of shape memory alloy actuators with internal electrical resistance feedback using neural networks SO SMART MATERIALS & STRUCTURES LA English DT Article AB The development of a position control system for a shape memory alloy (SMA) wire actuator using an electrical resistance feedback is presented in this paper. A novel control scheme is implemented to eliminate the need for a position sensor to achieve stable and accurate positioning by utilizing the actuator's electrical resistance feedback. Experiments are conducted to investigate the relationship between electrical resistance and displacement using an SMA wire test set-up. Due to the highly nonlinear behavior of the SMA actuator, a neural network is employed to model the relationship and to predict the position of the actuator using only the electrical resistance. Feedback control of the SMA is achieved by using a proportional-derivative (PD) controller. Experimental results demonstrate that the proposed position control system achieves good control performance without using a position sensor. C1 Univ Houston, Dept Mech Engn, Houston, TX 77204 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Song, G (reprint author), Univ Houston, Dept Mech Engn, Houston, TX 77204 USA. EM gsong@uh.edu NR 12 TC 94 Z9 95 U1 2 U2 13 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD AUG PY 2004 VL 13 IS 4 BP 777 EP 783 AR PII S0964-1726(04)77382-6 DI 10.1088/0964-1726/13/4/015 PG 7 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 848EV UT WOS:000223451200015 ER PT J AU Rubinstein, R Clark, TT AF Rubinstein, R Clark, TT TI A generalized Heisenberg model for turbulent spectral dynamics SO THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS LA English DT Article DE isotropic turbulence; turbulence closures; Heisenberg model ID ISOTROPIC TURBULENCE; ENERGY-TRANSFER; LOCAL INTERACTIONS; DRIVEN FLOWS; SIMULATIONS; CLOSURE AB A simplified closure model for turbulent spectral dynamics is proposed. Beginning with an analytical closure similar to the test field model, energy transfer is modeled by replacing general triad interactions by degenerate triad interactions, resulting in a pair interaction description similar to the classical Heisenberg model. This energy transfer model is coupled to a similarly simplified time scale evolution equation. These simplifications make it possible to preserve many features of much more complex analytical closures like the direct interaction approximation and the Lagrangian renormalized approximation in a computationally tractable model. The model is tested in decaying isotropic turbulence and in forced isotropic turbulence. It is found to exhibit refined properties, including energy backscatter to large scales and the bottleneck phenomenon. C1 NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23861 USA. Los Alamos Natl Lab, X Div, Grp X3, Los Alamos, NM 87545 USA. RP Rubinstein, R (reprint author), NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23861 USA. EM r.rubinstein@larc.nasa.gov NR 52 TC 10 Z9 10 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0935-4964 J9 THEOR COMP FLUID DYN JI Theor. Comput. Fluid Dyn. PD AUG PY 2004 VL 17 IS 4 BP 249 EP 272 DI 10.1007/s00162-004-0104-x PG 24 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 842NQ UT WOS:000223011500003 ER PT J AU Schunn, CD Vera, AH AF Schunn, CD Vera, AH TI Cross-cultural similarities in category structure SO THINKING & REASONING LA English DT Article ID FEATURE CENTRALITY; CONCEPTUAL COHERENCE; CAUSAL STATUS; CATEGORIZATION; COGNITION; ARTIFACTS; KINDS AB Categories, as mental structures, are more than simply sums of property frequencies. A number of recent studies have supported the view that the properties of categories may be organised along functional lines and possibly dependency structures more generally. The study presented here investigates whether earlier findings reflect something unique in the English language/North American culture or whether the functional structuring of categories is a more universal phenomenon. A population of English-speaking Americans was compared to a population of Cantonese-speaking Hong Kong Chinese. The findings clearly support the view that functional influences on category centrality are universal (or at least common to Cantonese-speaking Hong Kong Chinese and English-speaking Americans), albeit with specific cross-cultural/cross-linguistic group differences in the particular properties that are considered central to categories. C1 Univ Pittsburgh, Pittsburgh, PA 15260 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Schunn, CD (reprint author), Univ Pittsburgh, LRDC 821,3939 OHara St, Pittsburgh, PA 15260 USA. EM schunn@pitt.edu RI Schunn, Christian/H-2468-2011; OI Schunn, Christian/0000-0003-3589-297X NR 24 TC 2 Z9 2 U1 0 U2 1 PU PSYCHOLOGY PRESS PI HOVE PA 27 CHURCH RD, HOVE BN3 2FA, EAST SUSSEX, ENGLAND SN 1354-6783 J9 THINK REASONING JI Think Reasoning PD AUG PY 2004 VL 10 IS 3 BP 273 EP 287 DI 10.1080/13546780442000097 PG 15 WC Psychology, Experimental SC Psychology GA 843BA UT WOS:000223048600002 ER PT J AU DellaCorte, C AF DellaCorte, C TI There's value in these pages! SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM cdellacorte@stle.org NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 TRIBOL LUBR TECHNOL JI Tribol. Lubr. Technol. PD AUG PY 2004 VL 60 IS 8 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 841JK UT WOS:000222925900002 ER PT J AU Case, JL Manobianco, J Lane, JE Immer, CD Merceret, FJ AF Case, JL Manobianco, J Lane, JE Immer, CD Merceret, FJ TI An objective technique for verifying sea breezes in high-resolution numerical weather prediction models SO WEATHER AND FORECASTING LA English DT Article ID 29-KM ETA-MODEL; VERIFICATION; FORECASTS; FLORIDA; SYSTEM; RAMS AB An ongoing challenge in mesoscale numerical weather prediction (NWP) is to determine the ideal method for verifying the performance of high-resolution, detailed forecasts. Traditional objective techniques that evaluate NWP model performance based on point error statistics may not be positively correlated with the value of forecast information for certain applications of mesoscale NWP, and subjective evaluation techniques are often costly and time consuming. As a result, objective event-based verification methodologies are required in order to determine the added value of high-resolution NWP models. This paper presents a new objective technique to verify predictions of the sea-breeze phenomenon over east-central Florida by the Regional Atmospheric Modeling System ( RAMS) NWP model. The contour error map (CEM) technique identifies sea-breeze transition times in objectively analyzed grids of observed and forecast wind, verifies the forecast sea-breeze transition times against the observed times, and computes the mean post-sea-breeze wind direction and wind speed to compare the observed and forecast winds behind the sea-breeze front. The CEM technique improves upon traditional objective verification techniques and previously used subjective verification methodologies because it is automated, accounts for both spatial and temporal variations, correctly identifies and verifies the sea-breeze transition times, and provides verification contour maps and simple statistical parameters for easy interpretation. The CEM algorithm details are presented and validated against independent meteorological assessments of the sea-breeze transition times and results from a previously published subjective evaluation. C1 ENSCO Inc, Cocoa Beach, FL 32931 USA. ASRC Aerosp Inc, Cape Canaveral, FL USA. NASA, Kennedy Space Ctr, FL USA. RP Case, JL (reprint author), ENSCO Inc, 1980 N Atlantic Ave,Suite 230, Cocoa Beach, FL 32931 USA. EM case.jonathan@ensco.com NR 21 TC 16 Z9 16 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD AUG PY 2004 VL 19 IS 4 BP 690 EP 705 DI 10.1175/1520-0434(2004)019<0690:AOTFVS>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 845UY UT WOS:000223272000003 ER PT J AU Short, DA Sardonia, JE Lambert, WC Wheeler, MM AF Short, DA Sardonia, JE Lambert, WC Wheeler, MM TI Nowcasting thunderstorm anvil clouds over Kennedy Space Center and Cape Canaveral Air Force Station SO WEATHER AND FORECASTING LA English DT Article ID SQUALL-LINE; DOWNDRAFTS; MESOSCALE; FLORIDA; EVOLUTION AB Electrified thunderstorm anvil clouds extend the threat of natural and triggered lightning to space launch and landing operations far beyond the immediate vicinity of thunderstorm cells. The deep convective updrafts of thunderstorms transport large amounts of water vapor, supercooled water droplets, and ice crystals into the upper troposphere, forming anvil clouds, which are then carried downstream by the prevailing winds in the anvil-formation layer. Electrified anvil clouds have been observed over the space launch and landing facilities of the John F. Kennedy Space Center and Cape Canaveral Air Force Station (CCAFS), emanating from thunderstorm activity more than 200 km away. Space launch commit criteria and flight rules require launch and landing vehicles to avoid penetration of the nontransparent portion of anvil clouds. The life cycles of 163 anvil clouds over the Florida peninsula and its coastal waters were documented using Geostationary Operational Environmental Satellite (GOES)-8 visible imagery on 49 anvil-case days during the months of May - July 2001. Anvil clouds were found to propagate at the speed and direction of upper-tropospheric winds in the layer from 300 to 150 hPa, approximately 9.4 - 14 km in altitude, with an effective average transport lifetime of approximately 2 h and a standard deviation of approximately 30 min. The effective lifetime refers to the time required for the nontransparent leading edge of an anvil cloud to reach its maximum extent before beginning to dissipate. The information about propagation and lifetime was incorporated into the design, construction, and implementation of an objective short-range anvil forecast tool based on upper-air observations, for use on the Meteorological Interactive Data Display System within the Range Weather Operations facility of the 45th Weather Squadron at CCAFS and the Spaceflight Meteorology Group at Johnson Space Center. C1 ENSCO Inc, Cocoa Beach, FL 32931 USA. NASA, Appl Meteorol Unit, Kennedy Space Ctr, FL USA. USAF, Patrick AFB, FL USA. RP Short, DA (reprint author), ENSCO Inc, 1980 N Atlantic Ave,Suite 230, Cocoa Beach, FL 32931 USA. EM short.david@ensco.com NR 20 TC 6 Z9 6 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD AUG PY 2004 VL 19 IS 4 BP 706 EP 713 DI 10.1175/1520-0434(2004)019<0706:NTACOK>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 845UY UT WOS:000223272000004 ER PT J AU Cunnold, DM Yang, ES Newchurch, MJ Reinsel, GC Zawodny, JM Russell, JM AF Cunnold, DM Yang, ES Newchurch, MJ Reinsel, GC Zawodny, JM Russell, JM TI Comment on "Enhanced upper stratospheric ozone: Sign of recovery or solar cycle effect?" by W. Steinbrecht et al. SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material DE ozone recovery; stratosphere C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA. Univ Wisconsin, Dept Stat, Madison, WI 53706 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Cunnold, DM (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. EM cunnold@eas.gatech.edu; eun-su.yang@eas.gatech.edu; mike@nsstc.uah.edu; jm.zawodny@larc.nasa.gov; jmr@cas.hamptonu.edu NR 7 TC 18 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 31 PY 2004 VL 109 IS D14 AR D14305 DI 10.1029/2004JD004826 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 844VV UT WOS:000223190100002 ER PT J AU Espley, JR Cloutier, PA Brain, DA Crider, DH Acuna, MH AF Espley, JR Cloutier, PA Brain, DA Crider, DH Acuna, MH TI Observations of low-frequency magnetic oscillations in the Martian magnetosheath, magnetic pileup region, and tail SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE Mars; magnetic oscillations; magnetosheath; solar interaction; low frequency ID ELECTROMAGNETIC PLASMA-WAVES; MARS GLOBAL SURVEYOR; P GRIGG-SKJELLERUP; EARTHS MAGNETOSHEATH; UPSTREAM WAVES; SOLAR-WIND; BOW SHOCK; ANISOTROPY INSTABILITIES; FIELD FLUCTUATIONS; ION PICKUP AB Observations are presented of low-frequency magnetic oscillations in the Martian magnetosheath, magnetic pileup region, and tail as observed by the Magnetometer/Electron Reflectometer experiment on board Mars Global Surveyor. Within the dayside magnetosheath the oscillations are found to be predominantly compressional, elliptically polarized waves with wave vectors that have large angles relative to the mean field and dominant frequencies that are significantly below the local proton gyrofrequency. On the basis of these observations we identify these oscillations as mirror mode instabilities. In the nightside magnetosheath the oscillations are predominantly transverse and elliptical, and they propagate at smaller angles relative to the mean field at frequencies within a factor of 2-10 less than the local proton gyrofrequency. These characteristics lead us to associate these oscillations with ion/ion-resonant instabilities that arise from counterstreaming plasma populations such as the solar wind and pickup ions of planetary origin. Within the magnetic pileup region and tail the oscillations have considerably smaller amplitudes and are linearly polarized, obliquely propagating, ultralow-frequency oscillations which may be a mix of multiple wave modes. C1 Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20701 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Espley, JR (reprint author), Rice Univ, Dept Phys & Astron, MS-108, Houston, TX 77005 USA. EM espley@rice.edu; pac@spacibm.rice.edu; brain@ssl.berkeley.edu; dana.crider@gsfc.nasa.gov; mario.acuna@gsfc.nasa.gov RI Espley, Jared/I-5118-2013; Hurley, Dana/F-4488-2015 OI Espley, Jared/0000-0002-6371-9683; Hurley, Dana/0000-0003-1052-1494 NR 64 TC 42 Z9 42 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 31 PY 2004 VL 109 IS A7 AR A07213 DI 10.1029/2003JA010193 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 844WY UT WOS:000223193000001 ER PT J AU Reichardt, J Dornbrack, A Reichardt, S Yang, P McGgee, TJ AF Reichardt, J Dornbrack, A Reichardt, S Yang, P McGgee, TJ TI Mountain wave PSC dynamics and microphysics from ground-based lidar measurements and meteorological modeling SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID POLAR STRATOSPHERIC CLOUDS; NITRIC-ACID TRIHYDRATE; PARTICLE MICROPHYSICS; REFRACTIVE-INDEXES; OPTICAL-PROPERTIES; LIQUID PARTICLES; LIGHT-SCATTERING; ICE; TEMPERATURES; RAMAN AB The day-long observation of a polar stratospheric cloud (PSC) by two co-located ground-based lidars at the Swedish research facility Esrange (67.9degrees N, 21.1degrees E) on 16 January 1997 is analyzed in terms of PSC dynamics and microphysics. Mesoscale modeling is utilized to simulate the meteorological setting of the lidar measurements. Microphysical properties of the PSC particles are retrieved by comparing the measured particle depolarization ratio and the PSC-averaged lidar ratio with theoretical optical data derived for different particle shapes. In the morning, nitric acid trihydrate (NAT) particles and then increasingly coexisting liquid ternary aerosol (LTA) were detected as outflow from a mountain wave-induced ice PSC upwind Esrange. The NAT PSC is in good agreement with simulations for irregular-shaped particles with length-to-diameter ratios between 0.75 and 1.25, maximum dimensions from 0.7 to 0.9 mum, and a number density from 8 to 12 cm(-3) and the coexisting LTA droplets had diameters from 0.7 to 0.9 mum, a refractive index of 1.39 and a number density from 7 to 11 cm(-3). The total amount of condensed HNO3 was in the range of 8-12 ppbv. The data provide further observational evidence that NAT forms via deposition nucleation on ice particles as a number of recently published papers suggest. By early afternoon the mountain-wave ice PSC expanded above the lidar site. Its optical data indicate a decrease in minimum particle size from 3 to 1.9 mum with time. Later on, following the weakening of the mountain wave, wave-induced LTA was observed only. Our study demonstrates that ground-based lidar measurements of PSCs can be comprehensively interpreted if combined with mesoscale meteorological data. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. Deutsch Zentrum Luft & Raumfahrt DLR, Inst Phys Atmosphare, Wessling, Germany. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX USA. RP Reichardt, J (reprint author), Deutsch Wetterdienst, Meteorol Observ Lindenberg, Tauche, Germany. EM Jens.Reichardt@dwd.de RI Yang, Ping/B-4590-2011 NR 48 TC 17 Z9 17 U1 0 U2 1 PU COPERNICUS GESELLSCHAFT MBH PI GOTTINGEN PA BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY SN 1680-7316 EI 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JUL 30 PY 2004 VL 4 BP 1149 EP 1165 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 843CI UT WOS:000223052700001 ER PT J AU Weiss, BP Kim, SS Kirschvink, JL Kopp, RE Sankaran, M Kobayashi, A Komeili, A AF Weiss, BP Kim, SS Kirschvink, JL Kopp, RE Sankaran, M Kobayashi, A Komeili, A TI Ferromagnetic resonance and low-temperature magnetic tests for biogenic magnetite SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE biogenetic magnetite; Moskowitz test; ferromagnetic resonance; magnetotactic bacteria ID ELECTRON-PARAMAGNETIC RESONANCE; MAGNETOTACTIC BACTERIA; SINGLE-DOMAIN; MICROWAVE-ABSORPTION; METEORITE ALH84001; VERWEY TRANSITION; SPIN-RESONANCE; IRON; MAGNETOFOSSILS; SEDIMENTS AB Magnetite is both a common inorganic rock-forming mineral and a biogenic product formed by a diversity of organisms. Magnetotactic bacteria produce intracellular magnetites of high purity and crystallinity (magnetosomes) arranged in linear chains of crystals. Magnetosomes and their fossils (magnetofossils) have been identified using transmission electron microscopy (TEM) in sediments dating back to similar to 510-570 Ma, and possibly in 4 Ga carbonates in Martian meteorite ALH84001. We present the results from two rock magnetic analyses-the low-temperature Moskowitz test and ferromagnetic resonance (FMR)-applied to dozens of samples of magnetite and other materials. The magnetites in these samples are of diverse composition, size, shape, and origin: biologically induced (extracellular), biologically controlled (magnetosomes and chiton teeth), magnetofossil, synthetic, and natural inorganic. We confirm that the Moskowitz test is a distinctive indicator for magnetotactic bacteria and provide the first direct experimental evidence that this is accomplished via sensitivity to the magnetosome chain structure. We also demonstrate that the FMR spectra of four different strains of magnetotactic bacteria and a magnetofossil-bearing carbonate have a form distinct from all other samples measured in this study. We suggest that this signature also results from the magnetosomes' unique arrangement in chains. Because FMR can rapidly identify samples with large fractions of intact, isolated magnetosome chains, it could be a powerful tool for identifying magnetofossils in sediments. (C) 2004 Elsevier B.V. All rights reserved. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. Natl Inst AIST, Div Human Life Technol, Ikeda, Osaka 5638577, Japan. RP Weiss, BP (reprint author), CALTECH, Div Geol & Planetary Sci, 170-25, Pasadena, CA 91125 USA. EM bweiss@gps.caltech.edu; soonsam.kim@jpl.nasa.gov; kirschvink@caltech.edu; rkopp@caltech.edu; mohan@its.caltech.edu; komeili@gps.caltech.edu RI Kopp, Robert/B-8822-2008; Sankaran, R. Mohan/B-9668-2009; OI Kopp, Robert/0000-0003-4016-9428 NR 62 TC 102 Z9 102 U1 4 U2 22 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD JUL 30 PY 2004 VL 224 IS 1-2 BP 73 EP 89 DI 10.1016/j.espl.2004.04.024 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 843UW UT WOS:000223113100006 ER PT J AU Puchtel, IS Brandon, AD Humayun, M AF Puchtel, IS Brandon, AD Humayun, M TI Precise Pt-Re-Os isotope systematics of the mantle from 2.7-Ga komatiites SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Pt-Re-Os; mantle isotope systematics; highly siderophile elements; Archean romatiites; Pyke Hill; late veneer ID ABITIBI GREENSTONE-BELT; PLATINUM-GROUP ELEMENTS; BALTIC SHIELD; RE-187-OS-187 SYSTEMATICS; ARCHEAN MANTLE; OS-186-OS-187 SYSTEMATICS; CONTINENTAL-CRUST; IRON-METEORITES; MUNRO-TOWNSHIP; GORGONA ISLAND AB Precise Pt-Re-Os isotopic and highly siderophile element (HSE) data are reported for 10 drill core samples collected across a 2.7 m thick, differentiated komatiite lava flow at Pyke Hill in Ontario, Canada. The Pt-Re-Os isotopic data for five cumulate samples yield Re-Os and Pt-Os isochrons with ages of 2725+/-33 and 2956 760 Ma and initial Os-187/Os-188=0.10902+/-16 and Os-186/Os-188=0.1198318+/-18, respectively. These ages are consistent with the time of lava emplacement determined by other geochronometers. The initial (OsS)-Os-187/Os-188 isotopic composition of the Pyke Hill source is similar to the Os-187/Os-188 isotopic compositions of enstatite and ordinary chondrites and to that of PUM at 2725 Ma. Using the Pt-Os isotopic data for the Pyke Hill source, the present-day Os-186/Os-188 isotopic composition of PUM was calculated to be 0.1198387+/-18. The regression of global Os-187/Os-188 isotopic data for terrestrial materials shown to represent Os isotopic composition of the contemporary mantle indicates that the LILE-depleted mantle evolved from the solar system starting composition and, over Earth's history, was on average similar to 8% depleted in Re vs. Os relative to PUM. From the HSE composition of the emplaced Pyke Hill komatiite lava, the mantle source was inferred to contain Re (0.30 ppb), Os (3.9 ppb), Ir (3.6 ppb), Ru (5.4 ppb), Pt (6.4 ppb), and Pd (6.3 ppb) in relative proportions similar to those in average enstatite chondrites, except for Pd, which was enriched over Pt by similar to 30% in the Pyke Hill source compared to enstatite chondrites. From these data, the Pt-190/Os-188 Of PUM was calculated to be 0.00157. If the HSE abundances in the terrestrial mantle were inherited from chondritic material of a late veneer, the latter should have had the HSE composition of ordinary or enstatite chondrites. Alternatively, if the reenrichment of the mantle with HSE was the result of an open-system transport of material across the core-mantle boundary, it was likely a global event that should have occurred shortly after core formation. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Puchtel, IS (reprint author), Univ Maryland, Dept Geol, College Pk, MD 20742 USA. EM ipuchtel@mail.umd.edu OI Humayun, Munir/0000-0001-8516-9435 NR 67 TC 41 Z9 42 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD JUL 30 PY 2004 VL 224 IS 1-2 BP 157 EP 174 DI 10.1016/j.epsl.2004.04.035 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 843UW UT WOS:000223113100012 ER PT J AU Leventis, N Meador, MAB Zhang, GH Dass, A Sotiriou-Leventis, C AF Leventis, N Meador, MAB Zhang, GH Dass, A Sotiriou-Leventis, C TI Multiple substitution effects and three-dimensional Nonlinear free-energy relationships in the electrochemical reduction of the N,N ',-dibenzyl viologen and the 4-benzoyl-N-benzylpyridinium cation SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CROSS-INTERACTION CONSTANT; 4-BENZOYL-N-METHYLPYRIDINIUM CATIONS; STATISTICAL-ANALYSIS; HAMMETT EQUATION; REDOX CHEMISTRY; RESONANCE; BROMINATION; MOLECULES; SYSTEMS AB The simultaneous effect of two substituents on the redox potentials, E-1/2'S, of N, N'-di (p -substituted benzyl)viologens (1-X,Y) and of 4-(p-substituted benzoyl)-N-(p-substituted benzyl) pyridinium cations (2-X,Y), was investigated in terms of the substituent constants, sigma(p-X) and sigma(p-Y). Systems 1-X,Y and 2-X,Y were chosen because they both undergo successive outer sphere one electron (1-e) reductions, and therefore there is no ambiguity regarding the mechanism or the rate-determining step. Substituents (X and Y) were chosen among the -NO2, -Br, and -OCH3 groups in six different combinations for 1-X,Y's and nine different ones for 2-X,Y's. Response surfaces are essentially three-dimensional Hammett plots. Statistical analysis according to a quadratic model derived from the Taylor series expansion of the general extrathermodynamic relationship E-1/2 = F(sigma(p-X),sigma(p-Y)) that describes the dependence of E-1/2'S on the substituent constants shows that the substitution effect is not additive. Quite strong nonlinear terms appear when substituents can interact through resonance with a site involved in the electron-transfer process. This, for example, is the case for the second -e reduction of 2-X,Y's. Other significant nonlinear effects are attributed to stereoelectronic effects in combination with the high polarizability of pi-electrons. Our results have important implications on our ability to predict the effect of tuning of the redox potential of redox-active species through substitution. C1 NASA, Glenn Res Ctr, Div Mat, Cleveland, OH 44135 USA. Univ Missouri, Dept Chem, Rolla, MO 65409 USA. RP Leventis, N (reprint author), NASA, Glenn Res Ctr, Div Mat, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Nicholas.Leventis@nasa.gov; Maryann.Meador@nasa.gov; cslevent@umr.edu RI Dass, Amal/A-2520-2011; Dass, Amala/H-4729-2012; OI Dass, Amala/0000-0001-6942-5451; Meador, Mary Ann/0000-0003-2513-7372 NR 27 TC 4 Z9 4 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUL 29 PY 2004 VL 108 IS 30 BP 11228 EP 11235 DI 10.1021/jp049608a PG 8 WC Chemistry, Physical SC Chemistry GA 840MY UT WOS:000222864200083 ER PT J AU Haino, S Sanuki, T Abe, K Anraku, K Asaoka, Y Fuke, H Imori, M Itasaki, A Maeno, T Makida, Y Matsuda, S Matsui, N Matsumoto, H Mitchell, JW Moiseev, AA Nishimura, J Nozaki, M Orito, S Ormes, JF Sasaki, M Seo, ES Shikaze, Y Streitmatter, RE Suzuki, J Takasugi, Y Tanaka, K Tanizaki, K Yamagami, T Yamamoto, A Yamamoto, Y Yamato, K Yoshida, T Yoshimura, K AF Haino, S Sanuki, T Abe, K Anraku, K Asaoka, Y Fuke, H Imori, M Itasaki, A Maeno, T Makida, Y Matsuda, S Matsui, N Matsumoto, H Mitchell, JW Moiseev, AA Nishimura, J Nozaki, M Orito, S Ormes, JF Sasaki, M Seo, ES Shikaze, Y Streitmatter, RE Suzuki, J Takasugi, Y Tanaka, K Tanizaki, K Yamagami, T Yamamoto, A Yamamoto, Y Yamato, K Yoshida, T Yoshimura, K TI Measurements of primary and atmospheric cosmic-ray spectra with the BESS-TeV spectrometer SO PHYSICS LETTERS B LA English DT Article DE cosmic-ray proton; cosmic-ray helium; atmospheric muon; atmospheric neutrino; superconducting spectrometer ID HELIUM SPECTRA; ONBOARD BESS; SEA-LEVEL; PROTONS; MUONS; GEV/C AB Primary and atmospheric cosmic-ray spectra were precisely measured with the BESS-TeV spectrometer. The spectrometer was upgraded from BESS-98 to achieve seven times higher resolution in momentum measurement. We report absolute fluxes of primary protons and helium nuclei in the energy ranges, 1-540 GeV and 1-250 GeV/n, respectively, and absolute flux of atmospheric muons in the momentum range 0.6-400 GeV/c. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Tokyo, Bunkyo Ku, Tokyo 1130033, Japan. Kobe Univ, Kobe, Hyogo 6578501, Japan. High Energy Accelerator Res Org, KEK, Tsukuba, Ibaraki 3050801, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, College Pk, MD 20742 USA. JAXA, ISAS, Sagamihara, Kanagawa 2298510, Japan. RP Haino, S (reprint author), Univ Tokyo, Bunkyo Ku, Tokyo 1130033, Japan. EM haino@icepp.s.u-tokyo.ac.jp OI Seo, Eun-Suk/0000-0001-8682-805X NR 35 TC 162 Z9 162 U1 3 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUL 29 PY 2004 VL 594 IS 1-2 BP 35 EP 46 DI 10.1016/j.physletb.2004.05.019 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 839OY UT WOS:000222795600006 ER PT J AU Xueref, I Gerbig, C Fridlind, A Lin, JC Wofsy, SC Daube, BC Ackerman, AS Smith, JE Sayres, D Vellovic, J Baumgardner, DG Wang, D Weinstock, E Andrews, AE Gottlieb, EW Anderson, JG AF Xueref, I Gerbig, C Fridlind, A Lin, JC Wofsy, SC Daube, BC Ackerman, AS Smith, JE Sayres, D Vellovic, J Baumgardner, DG Wang, D Weinstock, E Andrews, AE Gottlieb, EW Anderson, JG TI Combining a receptor-oriented framework for tracer distributions with a cloud-resolving model to study transport in deep convective clouds: Application to the NASA CRYSTAL-FACE campaign SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID REGIONAL-SCALE FLUXES; ATMOSPHERIC OBSERVATIONS; SPATIAL VARIABILITY; CO2; CONTINENT; WATER; TOOL AB Quantitative models of deep convection play a central role to improve understanding of weather, trace gas distributions, and radiative regime of the upper troposphere. Cloud-resolving models of deep convection are useful tools to simulate relevant processes. Observations of tracers such as CO2 can provide critical constraints on mass transport within these models. However, such measurements do not span the entire four-dimensional domain in space and time. We introduce a new method to improve tracer constraints on such models, combining a Receptor-Oriented Atmospheric Modeling (ROAM) framework with airborne and ground-based CO2 data. We illustrate the application of ROAM in generating initial and boundary conditions of CO2 for cloud-resolving model simulations, for a case study in the CRYSTAL-FACE campaign. Observations and model results were compared for CO2 profiles from the surface up to 16 km, inside and outside of a deep convective cloud. ROAM generated concentration fields that agreed within 0.5 ppm (1sigma) of observations outside the cloud. When ROAM-derived initial and boundary CO2 concentrations were fed to a state-of-the-art cloud-resolving model ( DHARMA), the combined modeling system successfully reproduced observed concentration differences, 0.2 - 0.8 ppm, between in-cloud and out-of-cloud air at 9 similar to 14 km. Results suggest that similar to 25% of air at 14 km was lifted through the convective system from the PBL. This study demonstrates the potential of the receptor-oriented framework to constrain redistribution of air within convective systems using CO2, and it points to the need for better coordinated tracer measurements in future field missions. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Nacl Autonoma Mexico, Mexico City 04510, DF, Mexico. NASA, Langley Res Ctr, Hampton, VA 23681 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. RP Xueref, I (reprint author), CEA, Lab Sci Climat & Environm, Bat 711 Pte 2,Orme Merisiers, F-91191 Gif Sur Yvette, France. EM xueref@lsce.saclay.cea.fr RI Ackerman, Andrew/D-4433-2012; Fridlind, Ann/E-1495-2012; Andrews, Arlyn/K-3427-2012; Gerbig, Christoph/L-3532-2013 OI Ackerman, Andrew/0000-0003-0254-6253; Gerbig, Christoph/0000-0002-1112-8603 NR 17 TC 4 Z9 4 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 JUL 27 PY 2004 VL 31 IS 14 AR L14106 DI 10.1029/2004GL019811 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 844TQ UT WOS:000223183700001 ER PT J AU Eason, RG Pourmand, N Tongprasit, W Herman, ZS Anthony, K Jejelowo, O Davis, RW Stolc, V AF Eason, RG Pourmand, N Tongprasit, W Herman, ZS Anthony, K Jejelowo, O Davis, RW Stolc, V TI Characterization of synthetic DNA bar codes in Saccharomyces cerevisiae gene-deletion strains SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SEQUENCING METHOD; YEAST; GENOME AB Incorporation of strain-specific synthetic DNA tags into yeast Saccharomyces cerevisiae gene-deletion strains has enabled identification of gene functions by massively parallel growth rate analysis. However, it is important to confirm the sequences of these tags, because mutations introduced during construction could lead to significant errors in hybridization performance. To validate this experimental system, we sequenced 11,812 synthetic 20-mer molecular bar codes and adjacent sequences (>1.8 megabases synthetic DNA) by pyrosequencing and Sanger methods. At least 31% of the genome-integrated 20-mer tags contain differences from those originally synthesized. However, these mutations result in anomalous hybridization in only a small subset of strains, and the sequence information enables redesign of hybridization probes for arrays. The robust performance of the yeast gene-deletion dual oligonucleotide bar-code design in array hybridization validates the use of molecular bar codes in living cells for tracking their growth phenotype. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. Stanford Genome Technol Ctr, Palo Alto, CA 94304 USA. ELORET Corp, Sunnyvale, CA 94087 USA. Texas So Univ, Dept Biol, Houston, TX 77004 USA. Yale Univ, Dept Mol Cellular & Dev Biol, New Haven, CT 06520 USA. RP Stolc, V (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Mail Stop 229-3, Moffett Field, CA 94035 USA. EM vstolc@mail.arc.nasa.gov FU NHGRI NIH HHS [5PO1HG00205, P01 HG000205] NR 15 TC 48 Z9 53 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUL 27 PY 2004 VL 101 IS 30 BP 11046 EP 11051 DI 10.1073/pnas.0403672101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 842JM UT WOS:000223000200038 PM 15258289 ER PT J AU Moon, JS Chow, DH Schulman, JN Deelman, P Zinck, JJ Ting, DZY AF Moon, JS Chow, DH Schulman, JN Deelman, P Zinck, JJ Ting, DZY TI Experimental demonstration of split side-gated resonant interband tunneling devices SO APPLIED PHYSICS LETTERS LA English DT Article ID ELECTRICAL SPIN INJECTION; ROOM-TEMPERATURE; MAGNETIC SUPERLATTICES; QUANTUM-WELL; HETEROSTRUCTURES; SEMICONDUCTOR; TRANSISTORS; INAS AB We report a prototype side-gated asymmetric resonant interband tunneling device (RITD) fabricated with an AlSb/InAs/GaSb/AlSb heterostructure for Rashba spin filter applications. This device features independent control gates along the sides of an RITD mesa structure that can be used to provide an electric field orthogonal to the resonant tunneling current. The distribution of lateral wave vectors for electrons approaching the RITD active layers obtains a nonzero average through the application of the orthogonal electric field, a requirement for Rashba spin filter operation. Measured current-voltage curves show a modulation of the tunneling current with a side gate bias, demonstrating lateral electric-field projection into the resonant tunneling mesa structure. The prototype device was fabricated to submicron dimensions utilizing a conformal and scalable processing scheme. (C) 2004 American Institute of Physics. C1 HRL Labs LLC, Malibu, CA 90265 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Moon, JS (reprint author), HRL Labs LLC, Malibu, CA 90265 USA. EM jsmoon@hrl.com NR 23 TC 12 Z9 12 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 26 PY 2004 VL 85 IS 4 BP 678 EP 680 DI 10.1063/1.1769591 PG 3 WC Physics, Applied SC Physics GA 840JU UT WOS:000222855400056 ER PT J AU Guo, SP Wu, F Albin, S Tai, H Rogowski, RS AF Guo, SP Wu, F Albin, S Tai, H Rogowski, RS TI Loss and dispersion analysis of microstructured fibers by finite-difference method SO OPTICS EXPRESS LA English DT Article ID PHOTONIC CRYSTAL FIBERS; BEAM-PROPAGATION METHOD; OPTICAL WAVE-GUIDES; PERFECTLY MATCHED LAYER; FREQUENCY-DOMAIN METHOD; GALERKIN METHOD; ELEMENT-METHOD; VECTOR; MODES; PROFILE AB The dispersion and loss in microstructured fibers are studied using a full-vectorial compact-2D finite-difference method in frequency-domain. This method solves a standard eigen-value problem from the Maxwell's equations directly and obtains complex propagation constants of the modes using anisotropic perfectly matched layers. A dielectric constant averaging technique using Ampere's law across the curved media interface is presented. Both the real and the imaginary parts of the complex propagation constant can be obtained with a high accuracy and fast convergence. Material loss, dispersion and spurious modes are also discussed. (C) 2004 Optical Society of America. C1 Old Dominion Univ, Dept Elect & Comp Engn, Photon Lab, Norfolk, VA 23529 USA. NASA, Langley Res Ctr, Nondestruct Evaluat Sci Branch, Hampton, VA 23681 USA. RP Guo, SP (reprint author), Old Dominion Univ, Dept Elect & Comp Engn, Photon Lab, Norfolk, VA 23529 USA. EM sguo@odu.edu NR 50 TC 156 Z9 167 U1 0 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 JUL 26 PY 2004 VL 12 IS 15 BP 3341 EP 3352 DI 10.1364/OPEX.12.003341 PG 12 WC Optics SC Optics GA 841DG UT WOS:000222908900006 PM 19483859 ER PT J AU Brugarolas, PB Safonov, MG AF Brugarolas, PB Safonov, MG TI Learning about dynamical systems via unfalsification of hypotheses SO INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL LA English DT Article DE control; system identification; behavioural systems; adaptive control; model validation; set membership; falsification; experimental data AB This paper examines the problem of learning behaviours of a dynamical system from experimental data via unfalsification of hypotheses within the behavioural approach to system theory of Willems. Behaviours of the dynamic systems are postulated as hypotheses and then tested against experimental data. A simple and concise condition for falsification of hypotheses by experimental data in terms of a kernel is presented. The approach is applicable both to learning models for a plant and to adapting controllers to satisfy performance and robustness goals. Copyright (C) 2004 John Wiley Sons, Ltd. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ So Calif, Dept Elect Engn Syst, Los Angeles, CA 90089 USA. RP Brugarolas, PB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM paul.b.brugarolas@jpl.nasa.gov NR 25 TC 1 Z9 1 U1 0 U2 3 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1049-8923 J9 INT J ROBUST NONLIN JI Int. J. Robust Nonlinear Control PD JUL 25 PY 2004 VL 14 IS 11 BP 933 EP 943 DI 10.1002/rnc.924 PG 11 WC Automation & Control Systems; Engineering, Electrical & Electronic; Mathematics, Applied SC Automation & Control Systems; Engineering; Mathematics GA 837BQ UT WOS:000222601800002 ER PT J AU Gao, ST Ping, F Li, XF Tao, WK AF Gao, ST Ping, F Li, XF Tao, WK TI A convective vorticity vector associated with tropical convection: A two-dimensional cloud-resolving modeling study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE convective vorticity vector; tropical convection; 2-D cloud model ID MOIST POTENTIAL VORTICITY; FRONTAL RAINBANDS; EXTRATROPICAL CYCLONES; MICROSCALE STRUCTURE; PHASE-III; MESOSCALE; SYSTEMS; PRECIPITATION; PARAMETERIZATION; ORGANIZATION AB Although dry/moist potential vorticity (((xi) over right arrow).deltheta(e))/rho) is a useful physical quantity for meteorological analysis, it cannot be applied to the analysis of two-dimensional (2-D) simulations. A new vorticity vector ((xi) over right arrow )x deltheta(e))/rho (convective vorticity vector (CVV)) is introduced in this study to analyze 2-D cloud-resolving simulation data associated with 2-D tropical convection. The cloud model is forced by the vertical velocity, zonal wind, horizontal advection, and sea surface temperature obtained from the Tropical Ocean-Global Atmosphere (TOGA) Coupled Ocean-Atmosphere Response Experiment (COARE) and is integrated for a selected 10-day period. The CVV has zonal and vertical components in the 2-D x-z frame. Analysis of zonally averaged and mass-integrated quantities shows that the correlation coefficient between the vertical component of the CVV and the sum of the cloud hydrometeor mixing ratios is 0.81, whereas the correlation coefficient between the zonal component and the sum of the mixing ratios is only 0.18. This indicates that the vertical component of the CVV is closely associated with tropical convection. The tendency equation for the vertical component of the CVV is derived and the zonally averaged and mass-integrated tendency budgets are analyzed. The tendency of the vertical component of the CVV is determined by the interaction between the vorticity and the zonal gradient of cloud heating. The results demonstrate that the vertical component of the CVV is a cloud-linked parameter and can be used to study tropical convection. C1 Chinese Acad Sci, Inst Atmospher Phys, LACS, Beijing 100029, Peoples R China. Joint Ctr Satellite Data Assimilat, Camp Springs, MD USA. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Camp Springs, MD USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Chinese Acad Sci, Inst Atmospher Phys, LACS, Beijing 100029, Peoples R China. EM gst@lasg.iap.ac.cn; pingf@mail.iap.ac.cn; xiaofan.li@noaa.gov; tao@agnes.gsfc.nasa.gov RI Li, Xiaofan/F-5605-2010; Li, Xiaofan/G-2094-2014 NR 31 TC 71 Z9 102 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 24 PY 2004 VL 109 IS D14 AR D14106 DI 10.1029/2004JD004807 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 841GC UT WOS:000222916600002 ER PT J AU Soja, AJ Cofer, WR Shugart, HH Sukhinin, AI Stackhouse, PW McRae, DJ Conard, SG AF Soja, AJ Cofer, WR Shugart, HH Sukhinin, AI Stackhouse, PW McRae, DJ Conard, SG TI Estimating fire emissions and disparities in boreal Siberia (1998-2002) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review DE AVHRR; area burned; emissions; boreal Siberia ID TRANSFORM INFRARED-SPECTROSCOPY; TERRESTRIAL CARBON STORAGE; CLOUD CONDENSATION NUCLEI; FOREST-FIRES; CLIMATE-CHANGE; RUSSIAN FORESTS; BURNED AREA; JACK PINE; WILDFIRE; CANADA AB [ 1] In the biomass, soils, and peatlands of Siberia, boreal Russia holds one of the largest pools of terrestrial carbon. Because Siberia is located where some of the largest temperature increases are expected to occur under current climate change scenarios, stored carbon has the potential to be released with associated changes in fire regimes. Our concentration is on estimating a wide range of current and potential emissions from Siberia on the basis of three modeled scenarios. An area burned product of Siberia is introduced, which spans from 1998 through 2002. Emissions models are spatially explicit; therefore area burned is extracted from associated ecoregions for each year. Carbon consumption estimates are presented for 23 unique ecoregions across Siberia, which range from 3.4 to 75.4 t C ha(-1) for three classes of severity. Total direct carbon emissions range from the traditional scenario estimate of 116 Tg C in 1999 (6.9 M ha burned) to the extreme scenario estimate of 520 Tg C in 2002 (11.2 M ha burned), which are equivalent to 5 and 20%, respectively, of total global carbon emissions from forest and grassland burning. Our results suggest that disparities in the amount of carbon stored in unique ecosystems and the severity of fire events can affect total direct carbon emissions by as much as 50%. Additionally, in extreme fire years, total direct carbon emissions can be 37 - 41% greater than in normal fire years, owing to increased soil organic matter consumption. Mean standard scenario estimates of CO2 ( 555 - 1031 Tg), CO ( 43 - 80 Tg), CH4 (2.4 - 4.5 Tg), TNMHC (2.2 - 4.1 Tg), and carbonaceous aerosols (4.6 - 8.6 Tg) represent 10, 15, 19, 12 and 26%, respectively, of the global estimates from forest and grassland burning. Accounting for smoldering combustion in soils and peatlands results in increases in CO, CH4, and TNMHC and decreases in CO2 emitted from fire events. C1 Terra Syst Res Inc, Williamsburg, VA 23185 USA. US Forest Serv, USDA, Arlington, VA 22209 USA. Nat Resources Canada, Great Lakes Forestry Ctr, Sault Ste Marie, ON P6A 2E5, Canada. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. Russian Acad Sci, Sukachev Forest Inst, Krasnoyarsk 660036, Russia. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Soja, AJ (reprint author), NASA, Langley Res Ctr, 21 Langley Blvd,MS 420, Hampton, VA 23681 USA. EM a.j.soja@larc.nasa.gov RI Conard, Susan/H-8158-2013; Shugart, Herman/C-5156-2009 NR 126 TC 89 Z9 94 U1 2 U2 23 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 23 PY 2004 VL 109 IS D14 AR D14S06 DI 10.1029/2004JD004570 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 841GB UT WOS:000222916500002 ER PT J AU Campbell, BA Maxwell, TA Freeman, A AF Campbell, BA Maxwell, TA Freeman, A TI Mars orbital synthetic aperture radar: Obtaining geologic information from radar polarimetry SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Mars; radar ID SHUTTLE IMAGING RADAR; SAR DATA; BIR-SAFSAF; PENETRATION; SCATTERING; SURFACE; BACKSCATTERING; ATTENUATION; CALIBRATION; ROUGHNESS AB Radar penetration of mantling layers, and scattering from buried objects or interfaces, is a topic of current interest in both terrestrial and planetary remote sensing. We examine the behavior of surface and subsurface scattering interfaces and the types of information that may be obtained from observations in different polarizations and wavelengths. These results are applied to the design of a future Mars orbital synthetic aperture radar (SAR), for which we draw the following conclusions. (1) Mapping of buried geologic features is best accomplished using VV polarization, at an optimal wavelength determined by the competing effects of antenna gain, attenuation in the dust, and the reduction in effective surface roughness with wavelength. P band frequencies (similar to1 GHz or less) offer the best opportunity for detection of moderately rough, buried features. (2) The relative roles of surface and subsurface scattering may be determined using measurements in HH and VV polarization, with a channel gain calibration better than 0.5 dB. (3) The thickness of a mantling layer (or ice mass) cannot be directly inferred from multiwavelength observations. Layer thickness may be inferred from the interferometric correlation of backscatter measurements collected on suitably spaced orbital passes, though the required phase measurement accuracy is challenging. While additional information may be gained by collecting scattering data in more polarizations or wavelengths, we suggest that the primary science goals of a Mars-orbiting radar could be accomplished by a single-wavelength system capable of collecting VV and HH polarizations with the calibration and orbit control needed to permit interferometric analysis. C1 Smithsonian Inst, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Campbell, BA (reprint author), Smithsonian Inst, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. EM campbellb@nasm.si.edu NR 40 TC 10 Z9 11 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 JUL 23 PY 2004 VL 109 IS E7 AR E07008 DI 10.1029/2004JE002264 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 841GN UT WOS:000222917900001 ER PT J AU Gorham, PW Hebert, CL Liewer, KM Naudet, CJ Saltzberg, D Williams, D AF Gorham, PW Hebert, CL Liewer, KM Naudet, CJ Saltzberg, D Williams, D TI Experimental limit on the cosmic diffuse ultrahigh energy neutrino flux SO PHYSICAL REVIEW LETTERS LA English DT Article ID RADIATION; EMISSION; PULSES AB We report results from 120 h of live time with the Goldstone lunar ultrahigh energy neutrino experiment (GLUE). The experiment searches for less than or equal to10 ns microwave pulses from the lunar regolith, appearing in coincidence at two large radio telescopes separated by 22 km and linked by optical fiber. Such pulses would arise from subsurface electromagnetic cascades induced by interactions of greater than or equal to100 EeV (1 EeV=10(18) eV neutrinos in the lunar regolith. No candidates are yet seen, and the implied limits constrain several current models for ultrahigh energy neutrino fluxes. C1 Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90024 USA. RP Gorham, PW (reprint author), Univ Hawaii, Dept Phys & Astron, 2505 Correa Rd, Honolulu, HI 96822 USA. NR 30 TC 167 Z9 168 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 23 PY 2004 VL 93 IS 4 AR 041101 DI 10.1103/PhysRevLett.93.041101 PG 4 WC Physics, Multidisciplinary SC Physics GA 840KC UT WOS:000222856400013 PM 15323748 ER PT J AU Tapley, BD Bettadpur, S Ries, JC Thompson, PF Watkins, MM AF Tapley, BD Bettadpur, S Ries, JC Thompson, PF Watkins, MM TI GRACE measurements of mass variability in the Earth system SO SCIENCE LA English DT Article ID SOIL-MOISTURE SIMULATIONS; TIME-VARIABLE GRAVITY; SATELLITE GRAVITY; FIELD; WATER; REDISTRIBUTION; PROJECT; LAGEOS AB Monthly gravity field estimates made by the twin Gravity Recovery and Climate Experiment (GRACE) satellites have a geoid height accuracy of 2 to 3 millimeters at a spatial resolution as small as 400 kilometers. The annual cycle in the geoid variations, up to 10 millimeters in some regions, peaked predominantly in the spring and fall seasons. Geoid variations observed over South America that can be largely attributed to surface water and groundwater changes show a clear separation between the large Amazon watershed and the smaller watersheds to the north. Such observations will help hydrologists to connect processes at traditional length scales ( tens of kilometers or less) to those at regional and global scales. C1 Univ Texas, Ctr Space Res, Austin, TX 78712 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Ries, JC (reprint author), Univ Texas, Ctr Space Res, Austin, TX 78712 USA. EM ries@csr.utexas.edu RI Bettadpur, Srinivas/M-3744-2014 NR 26 TC 760 Z9 807 U1 13 U2 125 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUL 23 PY 2004 VL 305 IS 5683 BP 503 EP 505 DI 10.1126/science.1099192 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 840AH UT WOS:000222828900035 PM 15273390 ER PT J AU Bullock, MA Moore, JM AF Bullock, MA Moore, JM TI Aqueous alteration of Mars-analog rocks under an acidic atmosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MARTIAN SOIL; SPECTROMETER; COMPONENTS; VOLATILES; REGOLITH; MINERALS; DUST AB We report on laboratory experiments in which we allowed an SNC-analog mineral mixture to react with water under a simulated Mars atmosphere containing the added gases SO2, HCl and NO2. The addition of acidic gases was designed to simulate the atmospheric effects of periods of increased volcanic activity on Mars. The S/Cl ratio in our experimental brines was about 200, compared with an average value of approximately 5 measured in martian fines at the Mars Pathfinder and Viking 1 and 2 landing sites. This suggests that if salts were produced under an atmosphere higher in acidic volatiles than at present, they would have produced evaporite deposits higher in S than is presently found in the martian fines. Erosion of these high-sulfur evaporites and mixing with eroded mafic basalts could have produced the globally homogenous, salt-rich mobile fines that are present on Mars today. C1 SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. NASA, Div Space Sci, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bullock, MA (reprint author), SW Res Inst, Dept Space Studies, 1050 Walnut St,Suite 400, Boulder, CO 80302 USA. EM bullock@boulder.swri.edu NR 15 TC 11 Z9 11 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 22 PY 2004 VL 31 IS 14 AR L14701 DI 10.1029/2004GL019980 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 841FS UT WOS:000222915500002 ER PT J AU Farrell, WM Kaiser, ML Kurth, WS Desch, MD Gurnett, DA Hospodarsky, GB MacDowall, RJ AF Farrell, WM Kaiser, ML Kurth, WS Desch, MD Gurnett, DA Hospodarsky, GB MacDowall, RJ TI Remote sensing of possible plasma density bubbles in the inner Jovian dayside magnetosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE Jupiter; Io torus; radio emission; electron cyclotron harmonics; interchange instability ID EQUATORIAL SPREAD-F; O-MODE EMISSION; KILOMETRIC RADIATION; IO TORUS; JUPITERS MAGNETOSPHERE; NONTHERMAL CONTINUUM; NUMERICAL-SIMULATION; RADIO; GENERATION; ULYSSES AB During the 2001 Cassini encounter with Jupiter, the Radio and Plasma Wave Science (RPWS) instrument detected fine spectral and temporal structure with broadband kilometric radiation. Applying known electron cyclotron harmonic radiation models, this microstructure is interpreted as originating from a plasma density depletion or bubble at the edge of the Io torus. The microstructure became very complicated at the event beginning and end (formation of broadband bursty structures), and this is interpreted as originating from high-frequency (3-4 s period) density waves or fingers found at the edge of the larger density bubble. Such high-frequency structure at the edges of plasma bubbles is reminiscent of small-scale structure associated with terrestrial spread-F density irregularities. We suggest that the narrow extended fingers, observed on a convex portion of the Io torus surface, result from the interchange instability that is shredding the outer edges of the plasma bubble. A similar set of circumstances occurring on a larger scale may explain the emission of Jovian radio bull's-eye emission observed previously by Ulysses. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52240 USA. RP Farrell, WM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM william.farrell@gsfc.nasa.gov; michael.l.kaiser@gsfc.nasa.gov; william-kurth@uiowa.edu; michael.desch@gsfc.nasa.gov; donald-gurnett@uiowa.edu; gbh@space.physics.uiowa.edu; robert.macdowall@gsfc.nasa.gov RI MacDowall, Robert/D-2773-2012; Farrell, William/I-4865-2013; OI Hospodarsky, George/0000-0001-9200-9878; Kurth, William/0000-0002-5471-6202 NR 40 TC 6 Z9 6 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 22 PY 2004 VL 109 IS A9 AR A09S14 DI 10.1029/2003JA010130 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 841GT UT WOS:000222918600001 ER PT J AU Kastner, JH Richmond, M Grosso, N Weintraub, DA Simon, T Frank, A Hamaguchi, K Ozawa, H Henden, A AF Kastner, JH Richmond, M Grosso, N Weintraub, DA Simon, T Frank, A Hamaguchi, K Ozawa, H Henden, A TI An X-ray outburst from the rapidly accreting young star that illuminates McNeil's nebula SO NATURE LA English DT Article ID STELLAR OBJECTS; ORION NEBULA; EMISSION; PROTOSTARS; DISCOVERY; ROTATION; CLUSTER; SYSTEM; SCALE; JETS AB Young, low-mass stars are luminous X-ray sources(1) whose powerful X-ray flares(2-6) may exert a profound influence over the process of planet formation(7). The origin of the X-ray emission is uncertain. Although many (or perhaps most) recently formed, low-mass stars emit X-rays as a consequence of solar-like coronal activity(1,8,9), it has also been suggested that X-ray emission may be a direct result of mass accretion onto the forming star(10-12). Here we report X-ray imaging spectroscopy observations which reveal a factor similar to50 increase in the X-ray flux from a young star that is at present undergoing a spectacular optical/infrared outburst(13) (this star illuminates McNeil's nebula(14)). The outburst seems to be due to the sudden onset of a phase of rapid accretion(13,15,16). The coincidence of a surge in X-ray brightness with the optical/infrared eruption demonstrates that strongly enhanced high-energy emission from young stars can occur as a consequence of high accretion rates. We suggest that such accretion-enhanced X-ray emission from erupting young stars may be short-lived, because intense star-disk magnetospheric interactions are quenched rapidly by the subsequent flood of new material onto the star. C1 Rochester Inst Technol, Rochester, NY 14623 USA. Univ Grenoble 1, Lab Astrophys Grenoble, F-38041 Grenoble, France. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Rochester, Rochester, NY 14627 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN Observ, Flagstaff, AZ 86002 USA. RP Kastner, JH (reprint author), Rochester Inst Technol, Rochester, NY 14623 USA. EM jhk@cis.rit.edu NR 30 TC 45 Z9 45 U1 0 U2 1 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 22 PY 2004 VL 430 IS 6998 BP 429 EP 431 DI 10.1038/nature02747 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 839RD UT WOS:000222801400035 PM 15269761 ER PT J AU Park, C Ounaies, Z Wise, KE Harrison, JS AF Park, C Ounaies, Z Wise, KE Harrison, JS TI In situ poling and imidization of amorphous piezoelectric polyimides SO POLYMER LA English DT Article DE poling; polyimide; piezoelectricity ID VINYLIDENE CYANIDE; POLARIZATION; ACETATE AB An amorphous piezoelectric polyimide containing polar functional groups has been developed using a combination of experimental and molecular modeling for potential use in high temperature applications. This amorphous polyimide, (beta-CN)APB/ODPA, has exhibited good thermal stability and piezoelectric response at temperatures up to 150 degreesC. Density functional calculations predicted that a partially cured amic acid (open imide ring) possesses a dipole moment four times larger than the fully imidized closed ring. In situ poling and imidization of the partially cured (beta-CN)APB/ODPA was studied in an attempt to maximize the degree of dipolar orientation and the resultant piezoelectric response. A positive corona poling was used to minimize localized arcing during poling and to allow use of higher poling fields without dielectric breakdown. The dielectric relaxation strength, remanent polarization, and piezoelectric response were evaluated as a function of the poling profile. The partially cured, corona poled polymers exhibited higher dielectric relaxation strength (Deltaepsilon), remanent polarization (P-r) and piezoelectric strain coefficient (d(33)) than the fully cured, conventionally poled ones. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Natl Inst Aerosp, Hampton, VA 23681 USA. Virginia Commonwealth Univ, Dept Mech Engn, Richmond, VA 23284 USA. NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. RP Park, C (reprint author), NASA, Langley Res Ctr, Natl Inst Aerosp, 144 Res Dr,MS-226,6 W Taylor St, Hampton, VA 23681 USA. EM c.park@larc.nasa.gov NR 20 TC 44 Z9 45 U1 2 U2 13 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 JUL 22 PY 2004 VL 45 IS 16 BP 5417 EP 5425 DI 10.1016/j.polymer.2004.05.057 PG 9 WC Polymer Science SC Polymer Science GA 841KC UT WOS:000222927700006 ER PT J AU Hergenrother, PM Watson, KA Smith, JG Connell, JW Yokota, R AF Hergenrother, PM Watson, KA Smith, JG Connell, JW Yokota, R TI Copolyimides from 2,3,3 ',4 '-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride with 4,4 '-oxydianiline SO POLYMER LA English DT Article DE polymides; 2,3,3 ',4 '-biphenyltetracarboxylic dianhydride; structure property relationship ID POLYIMIDES AB A series of copolyimides were prepared via the polyamide acids (polyamic acids) from the reaction of 2,3,3,4'-biphenyltetracarboxylic dianhydride (a-BPDA) and pyromellitic dianhydride (PMDA) with 4,4-oxydianiline (4,4'-ODA) at dianhydride molar ratios of 9:1, 7:3, 1:1, 3:7 and 1:9. Homopolymers and a 1:1 polymer blend were also prepared. Films from the 7:3, 1:1 and 3:7 molar ratio polyamide acids reacted for 5-6 h at ambient temperature were brittle, whereas films from the same polyamide acids reacted for 24-48 h at ambient temperature were fingernail creaseable. The difference was apparently due to the initial formation of incompatible block domains that underway randomization upon longer reaction time. The differential scanning calorimetric (DSC) curves of some of the brittle films quenched after heating to 400 degreesC had two apparent glass transition temperatures (T(g)s), indicative of two block domains. The creaseable films quenched after hearing to 400 degreesC had single T(g)s. Wide-angle X-ray diffraction showed all films to be amorphous even though the initial DSC curves showed strong endothermic peaks, generally associated with crystalline melts. These strong endotherms near the T-g region were thought to be due to relaxation of regions in the highly stressed films. Films of copolyamide acids from the reaction of 1:1 molar ratios of 3,3',4,4'-oxydiphthalic anhydride/a-BPDA and 3,3',4,4'-biphenyltetracarboxylic dianhydride/a-BPDA with 4,4'-ODA reacted for 6 It were fingernail creaseable. The chemistry and the properties of the copolymers are compared with those of the homopolymers. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Natl Inst Aerosp, Hampton, VA 23666 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa, Japan. RP Hergenrother, PM (reprint author), NASA, Langley Res Ctr, MS 226, Hampton, VA 23681 USA. EM p.m.hergenrother@larc.nasa.gov; k.a.watson@larc.nasa.gov NR 8 TC 27 Z9 29 U1 1 U2 13 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 JUL 22 PY 2004 VL 45 IS 16 BP 5441 EP 5449 DI 10.1016/j.polymer.2004.06.004 PG 9 WC Polymer Science SC Polymer Science GA 841KC UT WOS:000222927700008 ER PT J AU Zijlstra, AA Bedding, TR Markwick, AJ Loidl-Gautschy, R Tabur, V Alexander, KD Jacob, AP Kiss, LL Price, A Matsuura, M Mattei, JA AF Zijlstra, AA Bedding, TR Markwick, AJ Loidl-Gautschy, R Tabur, V Alexander, KD Jacob, AP Kiss, LL Price, A Matsuura, M Mattei, JA TI Period and chemical evolution of SC stars SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : AGB and post-AGB; stars : fundamental parameters; stars : individual : BH Cru ID ASYMPTOTIC GIANT BRANCH; T-URSAE-MINORIS; HE-SHELL FLASH; SEMIREGULAR VARIABLES; MASS-LOSS; MIRA VARIABLES; ABUNDANCES; SOLAR; MULTIPERIODICITY; EQUILIBRIUM AB The SC and CS stars are thermal-pulsing asymptotic giant branch stars with a C/O ratio close to unity. Within this small group, the Mira variable BH Cru recently evolved from spectral type SC (showing ZrO bands) to CS (showing weak C-2). Wavelet analysis shows that the spectral evolution was accompanied by a dramatic period increase, from 420 to 540 d, indicating an expanding radius. The pulsation amplitude also increased. Old photographic plates are used to establish that the period before 1940 was around 490 d. Chemical models indicate that the spectral changes were caused by a decrease in stellar temperature, related to the increasing radius. There is no evidence for a change in C/O ratio. The evolution in BH Cru is unlikely to be related to an ongoing thermal pulse. Periods of the other SC and CS stars, including nine new periods, are determined. A second SC star, LX Cyg, also shows evidence for a large increase in period, and one further star shows a period inconsistent with a previous determination. Mira periods may be intrinsically unstable for C/O approximate to 1; possibly because of a feedback between the molecular opacities, pulsation amplitude, and period. LRS spectra of 6 SC stars suggest a feature at lambda > 15 mum, which resembles one recently attributed to the iron-sulphide troilite. Chemical models predict a large abundance of FeS in SC stars, in agreement with the proposed association. C1 UMIST, Dept Phys, Manchester M60 1QD, Lancs, England. Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. AAVSO, Cambridge, MA 02138 USA. RP Zijlstra, AA (reprint author), UMIST, Dept Phys, POB 88, Manchester M60 1QD, Lancs, England. EM a.zijlstra@umist.ac.uk; bedding@physics.usyd.edu.au RI Kiss, Laszlo/A-2539-2008; OI Bedding, Timothy/0000-0001-5943-1460; Bedding, Tim/0000-0001-5222-4661 NR 69 TC 22 Z9 22 U1 0 U2 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUL 21 PY 2004 VL 352 IS 1 BP 325 EP 337 DI 10.1111/j.1365-2966.2004.07927.x PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 836TI UT WOS:000222578300031 ER PT J AU Hooker, SB Zibordi, G Berthon, JF Brown, JW AF Hooker, SB Zibordi, G Berthon, JF Brown, JW TI Above-water radiometry in shallow coastal waters SO APPLIED OPTICS LA English DT Article ID OPTICAL MEASUREMENTS; OCEAN COLOR; LEAVING RADIANCES; CHLOROPHYLL; SEAWIFS; VALIDATION; ALGORITHMS; PLATFORM AB Above- and in-water radiometric data were collected from two coastal platforms: a small boat and an oceanographic tower. The above-water data were processed with and without a correction for bidirectional effects (Q02 and S95, respectively). An intercomparison of water-leaving radiances over a wide range of environmental conditions showed (a) total uncertainties across the blue-green domain were to within 4%, (b) a convergence of the Q02 method with the in-water method (average Q02 intercomparisons were to within 4%), and (c) chlorophyll a concentrations derived from Q02 reflectances and the OC4V4 (Ocean Color 4 Version 4) algorithm agreed with independent high-performance liquid-chromatography determinations to within approximately 32%. (C) 2004 Optical Society of America. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. Inst Environm & Sustainabil, Joint Res Ctr, I-21020 Ispra, Italy. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Dept Meteorol & Phys Oceanog, Miami, FL 33149 USA. RP Hooker, SB (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. EM stan@ardbeg.gsfc.nasa.gov RI Hooker, Stanford/E-2162-2012 NR 42 TC 26 Z9 26 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 JUL 20 PY 2004 VL 43 IS 21 BP 4254 EP 4268 DI 10.1364/AO.43.004254 PG 15 WC Optics SC Optics GA 840ZH UT WOS:000222898600021 PM 15291073 ER PT J AU Park, SQ Miller, JM McClintock, JE Remillard, RA Orosz, JA Shrader, CR Hunstead, RW Campbell-Wilson, D Ishwara-Chandra, CH Rao, AP Rupen, MP AF Park, SQ Miller, JM McClintock, JE Remillard, RA Orosz, JA Shrader, CR Hunstead, RW Campbell-Wilson, D Ishwara-Chandra, CH Rao, AP Rupen, MP TI Spectral and timing evolution of the black hole x-ray Nova 4U 1543-47 during its 2002 outburst SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; black hole physics; stars : individual (IL Lupi, 4U 1543-47); X-rays : stars ID TRANSIENT GRO J1655-40; ACTIVE GALACTIC NUCLEI; NOVA XTE J1550-564; 4U 1543-47; EMISSION-LINE; IRON LINES; REFLECTION; MODEL; RADIO; DISK AB We present an X-ray spectral and timing analysis of 4U 1543-47 during its 2002 outburst based on 49 pointed observations obtained using the Rossi X-Ray Timing Explorer. The outburst reached a peak intensity of 4.2 crab in the 2-12 keV band and declined by a factor of 32 throughout the month-long observation. A 21.9 +/- 0.6 mJy radio flare was detected at 1026.75 MHz two days before the X-ray maximum; the radio source was also detected late in the outburst, after the X-ray source entered the "hard" state. The X-ray light curve exhibits the classic shape of a rapid rise and an exponential decay. The spectrum is soft and dominated by emission from the accretion disk. The continuum is fitted with a multicolor disk blackbody (kT(max) 1: 04 keV) and a power law (Gamma similar to 2.7). Midway through the decay phase, a strong low-frequency quasi-periodic oscillation (v = 7.3-8.1 Hz) was present for several days. The spectra feature a broad Fe Kalpha line that is asymmetric, suggesting that the line is due to relativistic broadening rather than Comptonization. Relativistic Laor models provide much better fits to the line than nonrelativistic Gaussian models, particularly near the beginning and end of our observations. The line fits yield estimates for the inner disk radius that are within 6R(g); this result and additional evidence indicates that this black hole may have a nonzero angular momentum. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. San Diego State Univ, Dept Astron, San Diego, CA 92182 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. TIFR, Natl Ctr Radio Astrophys, Pune 411007, Maharashtra, India. Natl Radio Astron Observ, Socorro, NM 87801 USA. RP Park, SQ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM spark@cfa.harvard.edu; jmmiller@cfa.harvard.edu; jem@cfa.harvard.edu; rr@space.mit.edu; orosz@zwartgat.sdsu.edu; shrader@grossc.gsfc.nasa.gov; rwh@physics.usyd.edu.au; dcw@physics.usyd.edu.au; ishwar@ncra.tifr.res.in; pramesh@ncra.tifr.res.in; mrupen@zia.aoc.nrao.edu NR 51 TC 55 Z9 55 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2004 VL 610 IS 1 BP 378 EP 389 DI 10.1086/421511 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838FU UT WOS:000222699700036 ER PT J AU Strohmayer, TE AF Strohmayer, TE TI Chandra observations of V407 Vulpeculae: Confirmation of the spin-up SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; novae, cataclysmic variables; stars : individual (RX J1914.4+2456); white dwarfs; X-rays : binaries; X-rays : stars ID DOUBLE-DEGENERATE POLAR; SHORTEST PERIOD BINARY; ROSAT; J0806.3+1527 AB V407 Vul (RX J1914.4+2456) is a candidate double-degenerate binary with a putative 1.756 mHz (9.5 minute) orbital frequency. In a previous timing study using archival ROSAT and ASCA data, we reported evidence for an increase of this frequency at a rate consistent with expectations for gravitational radiation from a detached ultracompact binary system. Here we report the results of new Chandra timing observations, which confirm the previous indications of spin-up of the X-ray frequency and provide much tighter constraints on the frequency derivative, (v)over dot. We obtained with Chandra a total of 90 ks of exposure in two epochs separated in time by 11.5 months. The total time span of the archival ROSAT, ASCA, and new Chandra data is now approximate to10.5 yr. This more than doubles the interval spanned by the ROSAT and ASCA data alone, providing much greater sensitivity to a frequency derivative. With the addition of the Chandra data, an increasing frequency is evident, and the mean (v)over dot is (7.0 +/- 0.8) x 10(-18) Hz s(-1). Although a long-term spin-up trend is confirmed, there is excess variance in the phase timing residuals, perhaps indicating shorter timescale torque fluctuations or phase instability associated with the source of the X-ray flux. Power spectral searches for periods longward of the 9.5 minute period do not find any significant modulations; however, the sensitivity of searches in this frequency range are somewhat compromised by the dithering of the Chandra attitude. The observed spin-up is of a magnitude consistent with that expected from gravitational radiation decay; however, the factor of approximate to3 variations in flux combined with the timing noise could conceivably result from accretion-induced spin-up of a white dwarf. Continued monitoring to explore correlations of torque with X-ray flux could provide a further test of this hypothesis. C1 NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Strohmayer, TE (reprint author), NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM stroh@clarence.gsfc.nasa.gov NR 18 TC 25 Z9 25 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2004 VL 610 IS 1 BP 416 EP 421 DI 10.1086/421384 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838FU UT WOS:000222699700040 ER PT J AU Zubko, V Li, D Lim, T Feuchtgruber, H Harwit, M AF Zubko, V Li, D Lim, T Feuchtgruber, H Harwit, M TI Observations of water vapor outflow from NML Cygnus SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; stars : individual (NML Cygni, VY Canis Majoris, W Hydrae); stars : mass loss; stars : winds, outflows ID VY CANIS MAJORIS; EVOLVED STARS; W-HYDRAE; INFRARED-EMISSION; PROPER MOTIONS; DUST SHELLS; MASS-LOSS; SPECTRUM; ENVELOPE; MASERS AB We report new observations of the far-infrared and submillimeter water vapor emission of NML Cygnus based on data gathered with the Infrared Space Observatory and the Submillimeter Wave Astronomy Satellite. We compare the emission from NML Cyg to that previously published for VY CMa and W Hya in an attempt to establish the validity of recently proposed models for the outflow from evolved stars. The data obtained support the contention by Ivezic & Elitzur that the atmospheres of evolved stars obey a set of scaling laws in which the optical depth of the outflow is the single most significant scaling parameter, affecting both the radiative transfer and the dynamics of the outflow. Specifically, we provide observations comparing the water vapor emission from NML Cyg, VY CMa, and W Hya and find, to the extent permitted by the quality of our data, that the results are in reasonable agreement with a model developed by Zubko & Elitzur. Using this model we derive a mass loss based on the dust opacities, spectral line fluxes, and outflow velocities of water vapor observed in the atmospheres of these oxygen-rich giants. For VY CMa and NML Cyg, we also obtain an estimate of the stellar mass. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Cornell Univ, Ithaca, NY 14853 USA. RP Zubko, V (reprint author), NASA, Goddard Space Flight Ctr, Code 913, Greenbelt, MD 20771 USA. NR 27 TC 11 Z9 11 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2004 VL 610 IS 1 BP 427 EP 435 DI 10.1086/421700 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838FU UT WOS:000222699700042 ER PT J AU Reames, DV Ng, CK AF Reames, DV Ng, CK TI Heavy-element abundances in solar energetic particle events SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; shock waves; Sun : abundances; Sun : coronal mass ejections (CMEs); Sun : flares; Sun : particle emission ID CORONAL MASS EJECTIONS; FLARES; IONS; ACCELERATION; WAVES; HE-3; WIND; ENHANCEMENTS; POPULATION; EVOLUTION AB We survey the relative abundances of elements with 1 less than or equal to Z less than or equal to 82 in solar energetic particle (SEP) events observed at 2 - 10 MeV amu(-1) during nearly 9 years aboard the Wind spacecraft, with special emphasis on enhanced abundances of elements with Z greater than or equal to 34. Abundances of Fe/O again show a bimodal distribution with distinct contributions from impulsive and gradual SEP events, as seen in earlier solar cycles. Periods with greatly enhanced abundances of ( 50 less than or equal to Z less than or equal to 56)/O, just as those with enhanced He-3/He-4, fall prominently in the Fe-rich population of the impulsive SEP events. In a sample of the 39 largest impulsive events, 25 have measurable enhancements in (50 less than or equal to Z less than or equal to 56)/O and (76 less than or equal to Z less than or equal to 82)/O, relative to coronal values, ranging from similar to100 to 10,000. By contrast, in a sample of 45 large gradual events the corresponding enhancements vary from similar to 0.2 to 20. However, the magnitude of the heavy-element enhancements in impulsive events is less striking than their strong correlation with the Fe spectral index and flare size, with the larggest enhancements occurringg in flares with the steepest Fe spectra, the smallest Fe fluence, and the lowest X-ray intensity, as reported here for the first time. Thus, it seems that small events with low energy input can produce only steep spectra of the dominant species but accelerate rare heavy elements with great efficiency, probably by selective absorption of resonant waves in the flare plasma. With increased energy input, enhancements diminish as heavy ions are depleted, and spectra of the dominant species harden. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Reames, DV (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM reames@milkyway.gsfc.nasa.gov; cheeng@milkyway.gsfc.nasa.gov NR 41 TC 63 Z9 64 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2004 VL 610 IS 1 BP 510 EP 522 DI 10.1086/421518 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838FU UT WOS:000222699700048 ER PT J AU Terradas, J Ofman, L AF Terradas, J Ofman, L TI Loop density enhancement by nonlinear magnetohydrodynamic waves SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : corona; Sun : magnetic fields waves ID SHEAR ALFVEN WAVES; SOLAR CORONAL LOOPS; RESONANT ABSORPTION; TRANSVERSE OSCILLATIONS; TRANSITION-REGION; SCALING LAWS; SIPHON FLOWS; DRIVEN; TRACE; SIMULATIONS AB We study the possibility that waves in coronal loops can produce density enhancements at loop tops. The mechanism involved is the ponderomotive force of standing magnetohydrodynamic (MHD) waves. We study the effect of large-amplitude waves in loops by first using a simple second-order one-dimensional MHD model for which analytical expressions are available. This simple model shows how Alfven waves can excite density fluctuations on slow timescales. Next, we solve the time-dependent nonlinear 2.5-dimensional MHD equations in an arcade model, in order to study the effect of nonuniform Alfven speed along the loop on large-amplitude waves. Finally, we solve the nonlinear three-dimensional MHD equations in a flux-tube configuration. Waves are launched by an initial transverse velocity profile in the loop, with footpoints fixed in the photosphere. We find that large initial disturbances produce a pressure imbalance along the loop, which results in an upflow from its legs. The accumulation of mass at the top of the oscillating loop can produce significant density enhancements for typical coronal conditions. In a later stage, the pressure gradient becomes dominant and inhibits the concentration of mass at the loop top. We find that oscillating loops observed by the EUV telescope on board TRACE on 1998 July 14 exhibit emission measure enhancements consistent with this mechanism. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Terradas, J (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. EM jaume@hubble.uib.es; ofman@waves.gsfc.nasa.gov RI Terradas, Jaume/L-6420-2014 OI Terradas, Jaume/0000-0002-7013-1933 NR 34 TC 39 Z9 39 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2004 VL 610 IS 1 BP 523 EP 531 DI 10.1086/421514 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838FU UT WOS:000222699700049 ER PT J AU Bauer, JM Buratti, BJ Simonelli, DP Owen, WM AF Bauer, JM Buratti, BJ Simonelli, DP Owen, WM TI Recovering the rotational light curve of Phoebe SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; Kuiper Belt; minor planets, asteroids planets; and satellites : individual (Phoebe); solar system : formation ID NEAR-INFRARED SPECTROSCOPY; CENTAURS; RESOLUTION; PHOTOMETRY; IAPETUS AB We present rotational light-curve data for Saturn's satellite Phoebe taken over the observing period prior to the Cassini mission's encounter with that moon. We find a rotation period of 9.2735 +/- 0.0006 hr, a factor of 25 improvement in the rotation period's uncertainty over previously published data. This improved rotation period measurement allow s us to correlate previously observed spectral features and colors with albedo features observed by Voyager and to predict which side of Phoebe will be observed by Cassini during its 2004 June 11 encounter. The light curve, sampled at subobserver latitudes farther south than achieved by Voyager, shows evidence of surface features that cannot be explained by previously published shape models or albedo maps and that may be located in the regions in Phoebe's southern hemisphere that were unobserved by Voyager. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bauer, JM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 183-501, Pasadena, CA 91109 USA. NR 18 TC 17 Z9 17 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2004 VL 610 IS 1 BP L57 EP L60 DI 10.1086/423131 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838GM UT WOS:000222701500015 ER PT J AU Bloemhof, EE AF Bloemhof, EE TI Remnant speckles in a highly corrected coronagraph SO ASTROPHYSICAL JOURNAL LA English DT Article DE instrumentation : adaptive optics; techniques : high angular resolution; techniques : image processing; turbulence ID ADAPTIVE OPTICS; NOISE AB Searches for faint companions to stars may use coronagraphs fed by adaptive optics (AO) systems of very high correction. Sensitivity will be limited by focal plane speckles from residual, uncorrected wave-front errors, so it is important to characterize remnant coronagraphic speckles. A general analysis is presented, illustrated with the classical Lyot coronagraph and the newer four quadrant phase mask scheme. Two kinds of remnant speckles, of distinct symmetry, occur that are closely analogous to those arising in direct imaging at high correction. Properties and typical intensity estimates are presented, which are useful for estimating speckle noise and false companion detection levels and reduction strategies. For realistic parameters describing some current groundbased observations, the novel antisymmetric "pinned" speckles, usually neglected even in direct imaging, are nonnegligible in narrowband short exposures. For parameters appropriate to a space-borne coronagraph on the Hubble Space Telescope, these anomalous speckles are in fact dominant close to the star and thus a potentially significant source of false companion detections. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bloemhof, EE (reprint author), CALTECH, Jet Prop Lab, Mail Stop 171-113,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 16 Z9 16 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2004 VL 610 IS 1 BP L69 EP L72 DI 10.1086/423172 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838GM UT WOS:000222701500018 ER PT J AU Burrows, A Hubeny, I Hubbard, WB Sudarsky, D Fortney, JJ AF Burrows, A Hubeny, I Hubbard, WB Sudarsky, D Fortney, JJ TI Theoretical radii of transiting giant planets: The case of OGLE-TR-56b SO ASTROPHYSICAL JOURNAL LA English DT Article DE planetary systems; planets and satellites : general; stars : individual (OGLE-TR-56b) ID GRAVITATIONAL LENSING EXPERIMENT; LUMINOSITY OBJECT TRANSITS; B-LIKE PLANETS; BROWN DWARFS; GALACTIC DISK; PARENT STAR; HD 209458B; ATMOSPHERES; HD-209458; EVOLUTION AB We calculate radius versus age trajectories for the photometrically selected transiting extrasolar giant planet, OGLE-TR-56b, and find agreement between theory and observation, without introducing an ad hoc extra source of heat in its core. The fact that the radius of HD 209458b seems larger than the radii of the recently discovered OGLE family of extremely close-in transiting planets suggests that HD 209458b is anomalous. Nevertheless, our good fit to OGLE-TR-56b bolsters the notion that the generic dependence of transit radii on stellar irradiation, mass, and age is, to within error bars, now quantitatively understood. C1 Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Univ Arizona, Dept Planetary Sci, Lunar & Planetary Lab, Tucson, AZ 85721 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Burrows, A (reprint author), Univ Arizona, Dept Astron, 933 N Cherry Ave,Room N204, Tucson, AZ 85721 USA. EM burrows@zenith.as.arizona.edu; hubeny@noao.edu; hubbard@lpl.arizona.edu; sudarsky@as.arizona.edu; jfortney@arc.nasa.gov OI Fortney, Jonathan/0000-0002-9843-4354 NR 39 TC 46 Z9 46 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2004 VL 610 IS 1 BP L53 EP L56 DI 10.1086/423173 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838GM UT WOS:000222701500014 ER PT J AU Hollis, JM Jewell, PR Lovas, FJ Remijan, A Mollendal, H AF Hollis, JM Jewell, PR Lovas, FJ Remijan, A Mollendal, H TI Green Bank Telescope detection of new interstellar aldehydes: Propenal and propanal SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : individual (Sagittarius B2(N-LMH)); ISM : molecules; radio lines : ISM ID MICROWAVE-SPECTRUM; GALACTIC-CENTER; GLYCOLALDEHYDE; MOLECULES; SUGARS; ICES AB The new interstellar molecules propenal (CH2CHCHO) and propanal (CH3CH2CHO) have been detected largely in absorption toward the star-forming region Sagittarius B2(N) by means of rotational transitions observed with the 100 m Green Bank Telescope (GBT) operating in the range from 18 GHz (lambda similar to 1.7 cm) to 26 GHz (lambda similar to 1.2 cm). The GBT was also used to observe the previously reported interstellar aldehyde propynal (HC2CHO) 1.2 in Sagittarius B2(N), which is a known source of large molecules presumably formed on interstellar grains. The presence of these three interstellar aldehydes toward Sagittarius B2( N) strongly suggests that simple hydrogen addition on interstellar grains accounts for successively larger molecular species: from propynal to propenal and from propenal to propanal. Energy sources within Sagittarius B2( N) likely permit the hydrogen addition reactions on grain surfaces to proceed. This work demonstrates that successive hydrogen addition is probably an important chemistry route in the formation of a number of complex interstellar molecules. We also searched for but did not detect the three-carbon sugar glyceraldehyde (CH2OHCHOHCHO). C1 NASA, Goddard Space Flight Ctr, Space & Earth Data Comp Div, Greenbelt, MD 20771 USA. Natl Radio Astron Observ, Green Bank, WV 24944 USA. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ Oslo, Dept Chem, N-0315 Oslo, Norway. RP Hollis, JM (reprint author), NASA, Goddard Space Flight Ctr, Space & Earth Data Comp Div, Code 930, Greenbelt, MD 20771 USA. NR 19 TC 95 Z9 95 U1 1 U2 12 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 2004 VL 610 IS 1 BP L21 EP L24 DI 10.1086/423200 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838GM UT WOS:000222701500006 ER PT J AU Tan, LC Fung, SF Shao, X AF Tan, LC Fung, SF Shao, X TI Observation of magnetospheric relativistic electrons accelerated by Pc-5 ULF waves SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SIMULATION; FIELD AB Magnetic field, electric field and energetic electron measurements from CRRES, GOES-6 and -7 satellites are used to investigate the production of up to 2 MeV electron fluxes through a storm sudden commencement (SSC) event on August 27, 1991. Strong Pc-5 oscillations, whose electric field is mainly along the radial direction, and up to an order-of-magnitude enhancement in relativistic electron fluxes occurred simultaneously in a two-hour period. The enhanced electron fluxes are found to have a pancake-like pitch angle distribution, which is consistent with the fluxes being accelerated near the equatorial plane. The electron acceleration is shown to result from drift-resonant interactions with the toroidal-mode Pc-5 ULF waves having wave frequencies three times the electron drift frequency. In view of the L-variation of ULF wave frequencies, electron acceleration to relativistic energies becomes more effective in the geosynchronous region. C1 NASA, Space Phys Data Facil, GSFC, Greenbelt, MD 20771 USA. NASA, QSS Grp Inc, GSFC, Greenbelt, MD 20771 USA. NASA, Natl Res Council, GSFC, Greenbelt, MD 20771 USA. RP Tan, LC (reprint author), NASA, Space Phys Data Facil, GSFC, Code 632, Greenbelt, MD 20771 USA. EM ltan@pop600.gsfc.nasa.gov; fung@mail630.gsfc.nasa.gov; shao@mail630.gsfc.nasa.gov RI Fung, Shing/F-5647-2012 NR 10 TC 26 Z9 27 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 20 PY 2004 VL 31 IS 14 AR L14802 DI 10.1029/2004GL019459 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 841FQ UT WOS:000222915300001 ER PT J AU Maune, B Loncar, M Witzens, J Hochberg, M Baehr-Jones, T Psaltis, D Scherer, A Qiu, YM AF Maune, B Loncar, M Witzens, J Hochberg, M Baehr-Jones, T Psaltis, D Scherer, A Qiu, YM TI Liquid-crystal electric tuning of a photonic crystal laser SO APPLIED PHYSICS LETTERS LA English DT Article ID RADIAL NEMATIC CONFIGURATION; BAND-GAP AB An electrically tuned nematic liquid-crystal (LC) infiltrated photonic crystal (PC) laser is demonstrated. This PC laser represents an emerging class of nanoscale optical adaptive devices enabled by the convergence of nonlinear optical materials, electronics, and fluidics that promise increased functionality and utility over existing technologies. A LC cell is constructed by encasing the PC laser between two indium tin oxide glass plates, which serve as the modulating electrodes. Applying a voltage across the cell realigns the LC, modifies the laser cavity's optical path length, and blueshifts the lasing wavelength. (C) 2004 American Institute of Physics. C1 CALTECH, Dept Elect Engn & Appl Phys, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, In Situ Technol & Expt Syst Sect, Pasadena, CA 91109 USA. RP Maune, B (reprint author), CALTECH, Dept Elect Engn & Appl Phys, Pasadena, CA 91125 USA. EM bmaune@caltech.edu RI Witzens, Jeremy/I-2579-2012 OI Witzens, Jeremy/0000-0002-2896-7243 NR 18 TC 106 Z9 107 U1 2 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 JUL 19 PY 2004 VL 85 IS 3 BP 360 EP 362 DI 10.1063/1.1772869 PG 3 WC Physics, Applied SC Physics GA 837ZO UT WOS:000222680400004 ER PT J AU Chiou, EW Thomason, LW Burton, SP Michelsen, HA AF Chiou, EW Thomason, LW Burton, SP Michelsen, HA TI Assessment of the SAGE II version 6.2 water vapor data set through intercomparison with ATMOS/ATLAS-3 measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERIC AEROSOL AB Based on the intercomparisons with ATMOS/ATLAS-3 measurements, the SAGE II (Stratospheric Aerosol and Gas Experiment II) version 6.2 water vapor profiles exhibit significant improvements over earlier versions of data products. A previously reported SAGE II dry bias in the lower stratosphere relative to ATMOS version 3 data set has been effectively eliminated. In the new version, the agreement between SAGE II and ATMOS is generally within 15% with no systematic biases throughout the entire altitude range of 12 km to 40 km. The only exception is the situation for which 1020-nm aerosol extinctions exceed the recommended upper limit of 3 X 10(-4) km(-1). Based on the comparisons, the reported uncertainties for SAGE II water vapor mixing ratios appear to be over-estimated by a factor of 2 to 3 for the lower stratosphere. C1 SAIC Inc, Hampton, VA USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA USA. RP Chiou, EW (reprint author), SAIC Inc, Hampton, VA USA. EM e.chiou@larc.nasa.gov NR 6 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 17 PY 2004 VL 31 IS 14 AR L14101 DI 10.1029/2004GL020071 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 839PN UT WOS:000222797100003 ER PT J AU Huang, CS Le, G Reeves, GD AF Huang, CS Le, G Reeves, GD TI Periodic magnetospheric substorms during fluctuating interplanetary magnetic field B-z SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB We study the possible role played by sudden changes in the solar wind in triggering substorm onsets. We show that periodic substorms can occur when the IMF B-Z is small and fluctuating between southward and northward. The period of the substorms during the fluctuating IMF is similar to3 hours, nearly the same as that during strongly and continuously southward IMF. We also show that large sudden changes in the solar wind do not necessarily trigger substorm onsets. For example, a northward IMF turning with a change of 31 nT in the IMF B-Z after 1.2 hours of strongly southward IMF (between -12 and -18 nT) did not cause a substorm onset. The observations show that the period of substorms is not controlled either directly by variations in the solar wind or indirectly by the energy transferred to the magnetosphere from the solar wind. We suggest that a sudden change in the solar wind can trigger a substorm onset if and only if the magnetosphere has reached a state conducive to the generation of substorms. Substorms will occur every similar to3 hours, no matter whether the IMF is continuously southward or fluctuating between southward and northward. C1 MIT, Haystack Observ, Westford, MA 01886 USA. NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Huang, CS (reprint author), MIT, Haystack Observ, Route 40, Westford, MA 01886 USA. EM cshuang@haystack.mit.edu; guan.le@nasa.gov; reeves@lanl.gov RI Le, Guan/C-9524-2012; Reeves, Geoffrey/E-8101-2011 OI Le, Guan/0000-0002-9504-5214; Reeves, Geoffrey/0000-0002-7985-8098 NR 11 TC 16 Z9 16 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 17 PY 2004 VL 31 IS 14 AR L14801 DI 10.1029/2004GL020180 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 839PN UT WOS:000222797100004 ER PT J AU Mendes, VB Pavlis, EC AF Mendes, VB Pavlis, EC TI High-accuracy zenith delay prediction at optical wavelengths SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID REFRACTIVE-INDEX; AIR AB A major limitation in accuracy in modern satellite laser ranging is the modeling of atmospheric refraction. Recent improvements in this area include the development of mapping functions to project the atmospheric delay experienced in the zenith direction to a given elevation angle. In this paper, we derive zenith delay models from revised equations for the computation of the refractive index of the atmosphere, valid for a wide spectrum of optical wavelengths. The zenith total delay predicted with these models were tested against ray tracing through radiosonde data from a full year of data, for 180 stations distributed worldwide, and showed sub-millimeter accuracy for wavelengths ranging from 0.355 mum to 1.064 mum. C1 Univ Lisbon, Fac Ciencias, Dept Matemat, P-1749016 Lisbon, Portugal. Univ Lisbon, Fac Ciencias, Lab Tectonofis & Tecton Expt, P-1749016 Lisbon, Portugal. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mendes, VB (reprint author), Univ Lisbon, Fac Ciencias, Dept Matemat, P-1749016 Lisbon, Portugal. EM vmendes@fc.ul.pt; epavlis@jcet.umbc.edu RI Mendes, Virgilio/K-6598-2012 OI Mendes, Virgilio/0000-0002-7362-8996 NR 6 TC 50 Z9 54 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 16 PY 2004 VL 31 IS 14 AR L14602 DI 10.1029/2004GL020308 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 839PM UT WOS:000222797000002 ER PT J AU Feely, RA Wanninkhof, R McGillis, W Carr, ME Cosca, CE AF Feely, RA Wanninkhof, R McGillis, W Carr, ME Cosca, CE TI Effects of wind speed and gas exchange parameterizations on the air-sea CO2 fluxes in the equatorial Pacific Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE carbon dioxide; air-sea exchange; gas exchange ID 1997-98 EL-NINO; INTERANNUAL VARIABILITY; SURFACE TEMPERATURE; PCO2 MEASUREMENTS; PCO(2); WATER; DISTRIBUTIONS; SALINITY AB [1] During the recent GasEx-2001 cruise in the Equatorial Pacific aboard the NOAA ship Ronald H. Brown, carbon measurements were made in the region of 3 degreesS, 125 degreesW. Continuous surface water fCO(2) measurements were conducted onboard in both underway and discrete analysis modes. During the 15-day experiment, surface water fCO(2) values averaged 473 +/- 2 muatm, providing a constant condition of supersaturation and flux of CO2 from the ocean to the atmosphere. The relationship of gas transfer with wind speed developed in this study is used along with regional estimates of air-water fCO(2) differences to determine CO2 fluxes in the equatorial Pacific. The regional fCO(2) fields are estimated from algorithms developed from previous measurements collected on the Ronald H. Brown and Ka'imimoana over the past 10 years between 5 degreesN and 10 degreesS, 90 degreesW and 165 degreesE. Using the W. McGillis et al. gas transfer-wind speed relationship, we estimate an average flux of 1.5 +/- 0.4 mol C m(-2) yr(-1) for the study region, with a six-fold difference in the regional efflux of CO2 between the strong El Nino events of 1986 - 1987 and 1997 - 1998 and the La Nina events of 1996 and 1999 - 2001 (i.e., 0.1 to 0.56 Pg C yr(-1)). The combined effects of uncertainties in the gas transfer velocity and wind fields lead to average difference of 27% between the lowest and highest estimates of the CO2 flux from the region. In contrast, the uncertainties in the fCO(2)-SST relationships give an average difference of about 35% between the lowest and highest estimates of the CO2 flux. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Woods Hole Oceanog Inst, Woods Hole, MA USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Feely, RA (reprint author), NOAA, Pacific Marine Environm Lab, Bin C15700,7600 Sand Point Way NE, Seattle, WA 98115 USA. EM richard.a.feely@noaa.gov; rik.wanninkhof@noaa.gov; wrm2102@columbia.edu; mec@pacific.jpl.nasa.gov; cathy.cosca@noaa.gov NR 39 TC 26 Z9 26 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUL 16 PY 2004 VL 109 IS C8 AR C08S03 DI 10.1029/2003JC001896 PG 10 WC Oceanography SC Oceanography GA 839QC UT WOS:000222798600003 ER PT J AU Lee, GW Gangopadhyay, AK Kelton, KF Hyers, RW Rathz, TJ Rogers, JR Robinson, DS AF Lee, GW Gangopadhyay, AK Kelton, KF Hyers, RW Rathz, TJ Rogers, JR Robinson, DS TI Difference in icosahedral short-range order in early and late transition metal liquids SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOND-ORIENTATIONAL ORDER; CLUSTERS; GLASSES; MAGNETISM; SPHERES AB New short-range order data are presented for equilibrium and undercooled liquids of Ti and Ni. These were obtained from in situ synchrotron x-ray diffraction measurements of electrostatically levitated droplets. While the short-range order of liquid Ni is icosahedral, consistent with Frank's hypothesis, significantly distorted icosahedral order is observed in liquid Ti. This is the first experimental observation of distorted icosahedral short-range order in any liquid, although this has been predicted by theoretical studies on atomic clusters. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. Univ Massachusetts, Amherst, MA 01003 USA. Univ Alabama, Huntsville, AL 35801 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Lee, GW (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA. RI Hyers, Robert/G-3755-2010 NR 27 TC 114 Z9 115 U1 1 U2 18 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 16 PY 2004 VL 93 IS 3 AR 037802 DI 10.1103/PhysRevLett.93.037802 PG 4 WC Physics, Multidisciplinary SC Physics GA 838CX UT WOS:000222691900067 PM 15323872 ER PT J AU Lim, YI Chang, SC Jorgensen, SB AF Lim, YI Chang, SC Jorgensen, SB TI A novel partial differential algebraic equation (PDAE) solver: iterative space-time conservation element/solution element (CE/SE) method SO COMPUTERS & CHEMICAL ENGINEERING LA English DT Article DE numerical analysis; partial differential algebraic equations (PDAEs); space-time CE/SE method; method of lines (MOL); chromatographic adsorption problem; protein ion-exchange separation ID STERIC MASS-ACTION; ION-EXCHANGE; NUMERICAL-METHODS; EULER EQUATIONS; CHROMATOGRAPHY; EQUILIBRIA; SEPARATION; SIMULATION; SYSTEMS; MODEL AB For solving partial differential algebraic equations (PDAEs), the space-time conservation element/solution element (CE/SE) method is addressed in this study. The method of lines (MOL) using an implicit time integrator is compared with the CE/SE method in terms of computational efficiency, solution accuracy and stability. The space-time CE/SE method is successfully implemented to solve PDAE systems through combining an iteration procedure for nonlinear algebraic equations. For illustration, chromatographic adsorption problems including convection, diffusion and reaction terms with a linear or nonlinear adsorption isotherm are solved by the two methods. The CE/SE method enforces both local and global flux conservation in space and time, and uses a simple stencil structure (two points at the previous time level and one point at the present time level). Thus, accurate and computationally-efficient numerical solutions are obtained. Stable solutions are guaranteed if the Courant-Friedrichs-Lewy (CFL) condition is satisfied. Solutions to two case studies demonstrate that the CE/SE numerical solutions are comparative in accuracy to those obtained from a MOL discretized by the 5th-order weighted essentially non-oscillatory (WENO) upwinding scheme with a significantly shorter calculation time. (C) 2003 Elsevier Ltd. All rights reserved. C1 Tech Univ Denmark, Dept Chem Engn, CAPEC, Lyngby, Denmark. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Lim, YI (reprint author), Tech Univ Denmark, Dept Chem Engn, CAPEC, Lyngby, Denmark. EM lim@kt.dtu.dk RI Jorgensen, Sten /B-2730-2010 OI Jorgensen, Sten /0000-0002-3179-972X NR 28 TC 18 Z9 22 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0098-1354 J9 COMPUT CHEM ENG JI Comput. Chem. Eng. PD JUL 15 PY 2004 VL 28 IS 8 BP 1309 EP 1324 DI 10.1016/j.compchemeng.2003.09.016 PG 16 WC Computer Science, Interdisciplinary Applications; Engineering, Chemical SC Computer Science; Engineering GA 825AH UT WOS:000221727900011 ER PT J AU Petrylak, DP Tangen, C Hussain, M Lara, PN Jones, J Talpin, ME Burch, P Greene, G Small, E Crawford, ED AF Petrylak, DP Tangen, C Hussain, M Lara, PN Jones, J Talpin, ME Burch, P Greene, G Small, E Crawford, ED TI SWOG 99-16: Randomized phase III trial of docetaxel (D)/estramustine (E) versus mitoxantrone(M)/prednisone(p) in men with androgen-independent prostate cancer (AIPCA) SO JOURNAL OF CLINICAL ONCOLOGY LA English DT Meeting Abstract CT 40th Annual Meeting of the American-Society-of-Clinical-Oncology CY JUN 05-08, 2004 CL New Orleans, LA SP Amer Soc Clin Oncol C1 New York Presbyterian Hosp, New York, NY USA. Univ Washington, Seattle, WA 98195 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Calif Davis, Ctr Canc, Sacramento, CA 95817 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Dana Farber Canc Ctr, Boston, MA USA. Mayo Clin, Rochester, MN USA. Univ Arkansas, Little Rock, AR 72204 USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. Univ Colorado, Denver, CO 80202 USA. NR 0 TC 2 Z9 2 U1 0 U2 2 PU AMER SOC CLINICAL ONCOLOGY PI ALEXANDRIA PA 330 JOHN CARLYLE ST, STE 300, ALEXANDRIA, VA 22314 USA SN 0732-183X J9 J CLIN ONCOL JI J. Clin. Oncol. PD JUL 15 PY 2004 VL 22 IS 14 SU S MA 3 BP 2S EP 2S PG 1 WC Oncology SC Oncology GA 849BL UT WOS:000223512400005 ER PT J AU Ranasinghe, KS Wei, PF Kelton, KF Ray, CS Day, DE AF Ranasinghe, KS Wei, PF Kelton, KF Ray, CS Day, DE TI Verification of an analytical method for measuring crystal nucleation rates in glasses from DTA data SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID LITHIUM DISILICATE GLASS; GROWTH-RATES; NONISOTHERMAL CRYSTALLIZATION; TRANSIENT NUCLEATION; LIQUIDS AB A recently proposed analytical (DTA) method for estimating the nucleation rates in glasses has been evaluated by comparing experimental data with numerically computed nucleation rates for a model lithium disilicate glass. The time and temperature dependent nucleation rates were predicted using the model and compared with those values extracted from an analysis of numerically calculated DTA curves. The validity of the numerical approach was demonstrated earlier by a comparison with experimental data. The excellent agreement between the nucleation rates from the model calculations and the computer generated DTA data demonstrates the validity of the proposed analytical DTA method. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Missouri, Dept Phys, Rolla, MO USA. Univ Missouri, Mat Res Ctr, Rolla, MO USA. MIT, Cambridge, MA 02139 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Missouri, Grad Ctr Mat Res, Rolla, MO USA. RP Ranasinghe, KS (reprint author), Univ Missouri, Dept Phys, Rolla, MO USA. EM ksranasinghe@yahoo.com NR 17 TC 10 Z9 10 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUL 15 PY 2004 VL 337 IS 3 BP 261 EP 267 DI 10.1016/j.jnoncrysol.2004.04.010 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 840SE UT WOS:000222879100008 ER PT J AU Li, C Ly, J Lei, B Fan, W Zhang, DH Han, J Meyyappan, M Thompson, M Zhou, CW AF Li, C Ly, J Lei, B Fan, W Zhang, DH Han, J Meyyappan, M Thompson, M Zhou, CW TI Data storage studies on nanowire transistors with self-assembled porphyrin molecules SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CRYSTALLINE IN2O3 NANOWIRES; MEMORY; MONOLAYERS AB Detailed memory studies have been carried out based on In2O3 nanowires coated with self-assembled monolayers of porphyrins. Devices with redox-active Co-chelated porphyrin coatings exhibited prominent memory effects, where the bit was represented by the charge stored in the molecules and the nanowire conductance was used as the readout. These devices exhibited reliable operation with on/off ratios of similar to10(4) and were electronically programmable and erasable. Temperature-dependent retention measurements revealed a thermal activation behavior with a barrier of 264 meV. While devices with Co-porphyrin coatings showed efficient memory operation, analogous protio porphyrin coated nanowire devices exhibited no memory effects. A largely metal-centered oxidation (e.g., Co2+/3+) appears to be important for achieving a memory effect in these devices. Our results have convincingly established a direct correlation between the molecular structure and the observed memory effect, and further in-depth studies may eventually lead to systems useful for practical applications. C1 Univ So Calif, Dept Elect Engn Electrophys, Los Angeles, CA 90089 USA. Univ So Calif, Dept Chem, Los Angeles, CA 90089 USA. NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Fan, W (reprint author), Univ So Calif, Dept Elect Engn Electrophys, Los Angeles, CA 90089 USA. EM wfan@mail.arc.nasa.gov; met@usc.edu; chongwuz@usc.edu RI Zhou, Chongwu/F-7483-2010; OI Thompson, Mark/0000-0002-7764-4096 NR 11 TC 78 Z9 79 U1 1 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUL 15 PY 2004 VL 108 IS 28 BP 9646 EP 9649 DI 10.1021/jp0498421 PG 4 WC Chemistry, Physical SC Chemistry GA 837MP UT WOS:000222639900017 ER PT J AU Remsberg, EE Gordley, LL Marshall, BT Thompson, RE Burton, J Bhatt, P Harvey, VL Lingenfelser, G Natarajan, M AF Remsberg, EE Gordley, LL Marshall, BT Thompson, RE Burton, J Bhatt, P Harvey, VL Lingenfelser, G Natarajan, M TI The Nimbus 7 LIMS version 6 radiance conditioning and temperature retrieval methods and results SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE satellite; temperature; infrared limb-sounder; middle atmosphere ID INFRARED MONITOR; STRATOSPHERE; INVERSION; ALGORITHMS; VALIDATION; DATABASE; BUDGET; BAND AB The Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) experiment operated for just over 7 months in 1978/1979, as planned. Its version 5 (V5) dataset was archived for public use in 1983. Subsequently, several important improvements were realized about the LIMS instrument, its forward radiance model, and the line parameters (from HITRAN 92 or 96) for the gases that emit in its broadband spectral channels. In addition, the orbital attitude knowledge for LIMS was refined by comparing the slopes of the observed radiance profiles from its two CO2 channels within the upper stratosphere through lower mesosphere. This approach also overcomes the usual requirement for absolute radiance calibrations in flight. The band model approximations employed for CO2 and interfering 03 and based on HITRAN for the 15-mum region are adequate for accurate retrievals of temperature versus pressure profiles T(p). Consequently, a reprocessed or Version 6 (V6) profile dataset was generated using these improved radiance conditioning methods (or Level 1) and the T(p) retrieval algorithm (or Level 2), and those updates are described briefly. In particular, the approach for V6 used all the radiance data (0.375 km vertical spacing), and the V6 retrievals are based on all the measured radiance,profiles along an orbit. Precision and accuracy of the V6 T(p) data are improved over that for V5, most noticeably in the mesosphere. Profiles of geopotential height have also been generated as part of the V6 dataset from which one can analyze its horizontal gradients for the wind fields and higher dynamical quantities, rather than mapping the temperature fields first. The entire LIMS V6 profile dataset was archived at the NASA Goddard Distributed Active Archive Center (DAAC) in September 2002. The high quality of these V6 data demonstrates more fully the promise of the broadband, limb-infrared remote sensing technique for operational measurements of middle atmosphere T(p) from Earth-orbiting satellites. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Atmospher Sci Res, Hampton, VA 23681 USA. RP Remsberg, EE (reprint author), NASA, Langley Res Ctr, Atmospher Sci Res, Mail Stop 401B, Hampton, VA 23681 USA. EM e.e.remsberg@larc.nasa.gov NR 28 TC 28 Z9 28 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 15 PY 2004 VL 86 IS 4 BP 395 EP 424 DI 10.1016/j.jqsrt.2003.12.007 PG 30 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 824WA UT WOS:000221716700007 ER PT J AU Pieri, D Abrams, M AF Pieri, D Abrams, M TI ASTER watches the world's volcanoes: a new paradigm for volcanological observations from orbit SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article; Proceedings Paper CT Fall Meeting of the American-Geophysical-Union CY DEC 10-14, 2001 CL SAN FRANCISCO, CA SP Amer Geophys Union DE ASTER; volcano monitoring; infrared remote sensing ID HYDROTHERMALLY ALTERED ROCKS; REFLECTION RADIOMETER ASTER; SPACEBORNE THERMAL EMISSION; KILAUEA-VOLCANO; MOUNT-ETNA; HAWAII; EMPLACEMENT; TEMPERATURE; RETRIEVALS; RESOLUTION AB Onboard NASA Terra spacecraft is one of the most sophisticated earth observing instruments ever flown, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), created as part of a joint project between the Japanese Ministry of Economy, Trade, and Industry and NASA. This instrument consists of three independent bore-sighted telescopes with 14 channels in the visible, near-infrared, and thermal infrared regions capable of being pointed up to 22.5degrees off-nadir. In addition, there is an additional backward-looking visible channel telescope for stereo-photogrammetric observations. The spatial resolutions are 15 m/pixel in the visible, 30 rn/pixel in the near-IR, and 90 m/pixel at thermal wavelengths, and the swath width is 60 km. ASTER instrument offers unprecedented opportunities for observing volcanoes and their activity from low earth orbit. It is the purpose of this short paper to introduce ASTER to the volcanological community, highlight its capabilities, advantages and limitations, and to show some examples of ASTER data and related analyses. We will also explain how users can readily access ASTER data. (C) 2004 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Earth & Space Sci Div, Pasadena, CA 91109 USA. RP Pieri, D (reprint author), CALTECH, Jet Prop Lab, Earth & Space Sci Div, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Dave.Pieri@jpl.nasa.gov; michael.abrams@jpl.nasa.gov NR 39 TC 66 Z9 67 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL 15 PY 2004 VL 135 IS 1-2 BP 13 EP 28 DI 10.1016/j.jvoleores.2003.12.018 PG 16 WC Geosciences, Multidisciplinary SC Geology GA 836FQ UT WOS:000222541500002 ER PT J AU Watson, IM Realmuto, VJ Rose, WI Prata, AJ Bluth, GJS Gu, Y Bader, CE Yu, T AF Watson, IM Realmuto, VJ Rose, WI Prata, AJ Bluth, GJS Gu, Y Bader, CE Yu, T TI Thermal infrared remote sensing of volcanic emissions using the moderate resolution imaging spectroradiometer SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article; Proceedings Paper CT Fall Meeting of the American-Geophysical-Union CY DEC 10-14, 2001 CL SAN FRANCISCO, CA SP Amer Geophys Union DE MODIS; infrared; remote sensing; volcanic emissions ID SATELLITE-BASED TECHNIQUE; SULFUR-DIOXIDE; KILAUEA-VOLCANO; ASH CLOUDS; FAILURES; AEROSOLS; HAWAII AB The volcanological community has a powerful new tool in the spaceborne moderate resolution imaging spectroradiometer (MODIS), which, from its synoptic perspective, provides satellite imagery of every volcano on Earth every 2 days. MODIS has the spectral characteristics to be able to utilise previously developed retrievals that quantify volcanic ash, ice, sulfates and sulfur dioxide using their thermal infrared (8-12 mum) transmission signature. In this paper, we present a detailed description of the methodologies, based within the thermal infrared region, that are being applied to MODIS data. MODIS data for two eruptions, Hekla, Iceland and Cleveland, Alaska are presented to show results from the ice, ash and SO2 retrieval schemes. We look at current problems with the retrievals used to quantify volcanic emissions, detail recent developments within the field that can be applied to MODIS data, and suggest areas where improvements need to be made in the future. Published by Elsevier B.V. C1 Michigan Technol Univ, Dept Geol & Mining Engn & Sci, Houghton, MI 49931 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CSIRO, Atmospher Res, Aspendale, Vic, Australia. RP Watson, IM (reprint author), Michigan Technol Univ, Dept Geol & Mining Engn & Sci, 1400 Townsend Dr, Houghton, MI 49931 USA. EM watson@mtu.edu RI Rose, William/A-7923-2009; Watson, Matt/E-5236-2011; OI Watson, Matt/0000-0001-9198-2203; Gu, Yingxin/0000-0002-3544-1856 NR 32 TC 88 Z9 92 U1 4 U2 20 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL 15 PY 2004 VL 135 IS 1-2 BP 75 EP 89 DI 10.1016/j.jvolgeores.2003.12.017 PG 15 WC Geosciences, Multidisciplinary SC Geology GA 836FQ UT WOS:000222541500005 ER PT J AU Worby, AP Comiso, JC AF Worby, AP Comiso, JC TI Studies of the Antarctic sea ice edge and ice extent from satellite and ship observations SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE Antarctic; sea ice; ice edge; passive microwave; ASPECT ID THICKNESS DISTRIBUTION; WHALING RECORDS; SNOW COVER; OCEAN; SIMULATIONS; DECLINE AB Passive microwave-derived ice edge locations in the Antarctic are assessed against in situ observations from ships between 1989 and 2000. During the growth season (March-October), the ship data agrees with satellite data very well, with r(2) values of 0.99 and 0.97 for the Bootstrap and Team algorithms, respectively. During the melt season (November-February), the agreement is not so good with the passive microwave ice edge typically 1-2degrees of latitude south of the observations. This is due to the low concentration and saturated nature of the ice, and the r(2) values for this period are 0.92 and 0.80 for the Bootstrap and Team algorithms, respectively. Sensitivity studies show that such an offset in the summer ice edge location can cause significant errors in trend studies of the extent of sea ice cover in the Southern Ocean. The passive microwave ice concentration at the ice edge observed by ship varies greatly, averaging 14% for the Team algorithm and 19% for the Bootstrap. Comparisons between passive microwave data and SAR, Landsat and OLS data during the ice growth season show that while small-scale details in ice edge location are lost, the passive microwave data generally provide good and consistent representation of the higher resolution imagery. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Tasmania, Australian Antarctic Div, Hobart, Tas 7001, Australia. Univ Tasmania, Antarctic Climate & Ecosyst Cooperat Res Ctr, Hobart, Tas 7001, Australia. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD USA. RP Worby, AP (reprint author), Univ Tasmania, Australian Antarctic Div, Private Bag 80, Hobart, Tas 7001, Australia. EM A.Worby@utas.edu.au RI Worby, Anthony/A-2373-2012 NR 35 TC 44 Z9 51 U1 1 U2 16 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 15 PY 2004 VL 92 IS 1 BP 98 EP 111 DI 10.1016/j.rse.2004.05.007 PG 14 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 842EL UT WOS:000222985900007 ER PT J AU Muller, D Mattis, I Ansmann, A Wehner, B Althausen, D Wandinger, U Dubovik, O AF Muller, D Mattis, I Ansmann, A Wehner, B Althausen, D Wandinger, U Dubovik, O TI Closure study on optical and microphysical properties of a mixed urban and Arctic haze air mass observed with Raman lidar and Sun photometer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE particle properties; Raman lidar; Sun photometer; urban pollution; Arctic haze ID SKY RADIANCE MEASUREMENTS; TO-BACKSCATTER RATIO; SIZE DISTRIBUTIONS; TROPOSPHERIC AEROSOL; PARTICLE PARAMETERS; VERTICAL PROFILES; CENTRAL-EUROPE; ALERT CANADA; SAHARAN DUST; APRIL 1986 AB [1] We present a comprehensive optical and microphysical characterization of an intense haze event observed over Leipzig ( 51.3 degreesN, 12.4 degreesE), Germany, in April 2002. This event was characterized by unusually high optical depths. The haze consisted of a mixture of urban and Arctic haze aerosols which were advected from the Arctic regions across eastern Europe and Scandinavia. For the first time a closure study on such an event could be carried out on the basis of combined observations with Raman lidar and Sun photometer. This study also served as a performance test of the inversion algorithms that are used for retrieving microphysical particle properties from the optical data sets. A comparison of parameters derived in this study to respective quantities determined in the Arctic regions showed that Arctic-haze-like material dominated the optical and microphysical particle properties, although a significant amount of this haze must have consisted of urban aerosols. The urban aerosols from eastern Europe had properties rather similar to those characteristic for the well-aged particles of Arctic haze. The major part of the haze was confined to heights below 3 km. Optical depth was 0.4 - 0.5 at 532 nm on 8 April 2002. The particle backscatter-to-extinction ( lidar) ratio varied between 35 and 75 sr at 355 and 532 nm. The Angstrom exponent of particle extinction in the wavelength range from 355 to 532 nm was 1.8 - 2.8. The inversion of the lidar optical data resulted in particle effective radii around 0.19 +/- 0.04 mum, volume concentrations of 16 - 33 mum(3) cm(-3), surface area concentrations of 270 - 510 mum(2) cm(-3), and a single-scattering albedo around 0.97 +/- 0.06 at 532 nm. Particle size distributions showed a rather pronounced monomodal structure in the accumulation mode, which is characteristic for well-aged particles. The particle properties derived from the two instruments agreed well for intensive parameters, i.e., Angstrom exponents, lidar ratio, effective radius, and single-scattering albedo. Extensive parameters, i.e., total particle surface area and particle volume concentration, showed similar values. C1 Inst Tropospharenforsch, D-04318 Leipzig, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Muller, D (reprint author), Inst Tropospharenforsch, Permoserstr 15, D-04318 Leipzig, Germany. EM detlef@tropos.de; ina@tropos.de; albert@tropos.de; birgit@tropos.de; dietrich@tropos.de; ulla@tropos.de; dubovik@aeronet.gsfc.nasa.gov RI Dubovik, Oleg/A-8235-2009; Wandinger, Ulla/E-3348-2014; Wehner, Birgit/C-2650-2014; MUELLER, DETLEF/F-1010-2015 OI Dubovik, Oleg/0000-0003-3482-6460; MUELLER, DETLEF/0000-0002-0203-7654 NR 57 TC 23 Z9 25 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 14 PY 2004 VL 109 IS D13 AR D13206 DI 10.1029/2003JD004200 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 839PS UT WOS:000222797600002 ER PT J AU Yashiro, S Gopalswamy, N Michalek, G St Cyr, OC Plunkett, SP Rich, NB Howard, RA AF Yashiro, S Gopalswamy, N Michalek, G St Cyr, OC Plunkett, SP Rich, NB Howard, RA TI A catalog of white light coronal mass ejections observed by the SOHO spacecraft SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE Coronal Mass Ejections (CMEs) ID ENERGETIC PARTICLE EVENTS; SOLAR MAXIMUM MISSION; SPEEDS; TRANSIENTS; STORMS; LASCO AB The Solar and Heliospheric Observatory (SOHO) mission's white light coronagraphs have observed nearly 7000 coronal mass ejections (CMEs) between 1996 and 2002. We have documented the measured properties of all these CMEs in an online catalog. We describe this catalog and present a summary of the statistical properties of the CMEs. The primary measurements made on each CME are the apparent central position angle, the angular width in the sky plane, and the height ( heliocentric distance) as a function of time. The height-time measurements are then fitted to first- and second-order polynomials to derive the average apparent speed and acceleration of the CMEs. The statistical properties of CMEs are (1) the average width of normal CMEs (20degrees < width &LE; 120&DEG;) increased from 47&DEG; (1996; solar minimum) to 61&DEG; (1999; early phase of solar maximum) and then decreased to 53&DEG; (2002; late phase of solar maximum), (2) CMEs were detected around the equatorial region during solar minimum, while during solar maximum CMEs appear at all latitudes, ( 3) the average apparent speed of CMEs increases from 300 km s(-1) (solar minimum) to 500 km s(-1) (solar maximum), (4) the average apparent speed of halo CMEs (957 km s(-1)) is twice of that of normal CMEs (428 km s(-1)), and (5) most of the slow CMEs (V &LE; 250 km s(-1)) show acceleration while most of the fast CMEs (V > 900 km s(-1)) show deceleration. Solar cycle variation and statistical properties of CMEs are revealed with greater clarity in this study as compared with previous studies. Implications of our findings for CME models are discussed. C1 Catholic Univ Amer, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Jagiellonian Univ, Astron Observ, PL-30244 Krakow, Poland. USN, Solar Phys Branch, Div Space Sci, Res Lab, Washington, DC 20375 USA. RP Yashiro, S (reprint author), Catholic Univ Amer, Washington, DC 20064 USA. EM yashiro@cdaw.gsfc.nasa.gov; gopals@fugee.gsfc.nasa.gov; michalek@oa.uj.edu.pl; chris.stcyr@nasa.gov; simon.plunkett@nrl.navy.mil; nathan.rich@nrl.navy.mil; russ.howard@nrl.navy.mil RI Gopalswamy, Nat/D-3659-2012 NR 42 TC 494 Z9 498 U1 6 U2 15 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 14 PY 2004 VL 109 IS A7 AR A07105 DI 10.1029/2003JA010282 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 839QJ UT WOS:000222799300001 ER PT J AU Willis, P Heflin, MB AF Willis, P Heflin, MB TI External validation of the GRACE GGM01C gravity field using GPS and DORIS positioning results SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SYSTEM AB We have used the new gravity field model GGM01C derived from GRACE data to reanalyze DORIS data from 1993.0 to 2003.2 using the Gipsy/Oasis software and a free-network approach. We have estimated the position and velocity of each DORIS station in ITRF2000. In order to test the accuracy of these results, we have compared them to the positions and velocities of 43 collocated GPS stations using local ties and covariance information. DORIS results computed using the GGM01C gravity field instead of the EGM96 gravity field show a significantly improved external agreement with GPS. Position agreement of 12 26 mm was reduced to 10 - 13 mm and velocity agreement of 3.3 - 3.7 mm/yr was reduced to 2.4 - 3.3 mm/yr. This can be interpreted as an external test of the accuracy of the new GGM01C gravity field. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Inst Geog Natl, Direct Tech, St Mande, France. RP Willis, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 238-600, Pasadena, CA 91109 USA. EM pascal.r.willis@jpl.nasa.gov RI Willis, Pascal/A-8046-2008 OI Willis, Pascal/0000-0002-3257-0679 NR 19 TC 35 Z9 35 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 13 PY 2004 VL 31 IS 13 AR L13616 DI 10.1029/2004GL020038 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 839PJ UT WOS:000222796700004 ER PT J AU Schoeberl, MR AF Schoeberl, MR TI Extratropical stratosphere-troposphere mass exchange SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE stratosphere-troposphere exchange ID CROSS-TROPOPAUSE EXCHANGE; NORTHERN-HEMISPHERE; POTENTIAL VORTICITY; RESIDUAL CIRCULATION; GENERAL-CIRCULATION; LAGRANGIAN ESTIMATE; WATER-VAPOR; TRANSPORT; OZONE; MODEL AB [1] The net mass flux from the stratosphere to the troposphere can be computed from the heating rate along the 380 K isentropic surface and the time rate of change of the mass of the lowermost stratosphere ( the region between the tropopause and the 380 K isentrope) following Appenzeller et al. [ 1996]. Given this net mass flux and the cross-tropopause diabatic mass flux, the residual adiabatic mass flux across the tropopause can also be estimated. These fluxes have been computed using meteorological fields from a free-running general circulation model ( the finite volume general circulation model) and two assimilated data sets, finite volume data assimilation system (FVDAS), and UK Met Office (UKMO). All of the calculations agree that the annual average net mass flux for the Northern Hemisphere is about 10(10) kg/s. There is less agreement on the Southern Hemisphere flux that might be half as large. For all three data sets the adiabatic mass flux is from the upper troposphere into the lowermost stratosphere. This adiabatic flux into the lowermost stratosphere is roughly 5 times larger than the diabatic mass flux into the stratosphere across the tropical tropopause. For the FVDAS the midlatitude tropopause diabatic flux is smaller than UKMO, apparently due to a systematically colder, higher FVDAS tropopause. Both data assimilation systems have a warmer, lower midlatitude tropopause compared to radiosondes, so the mass flux estimates can be considered upper bounds. Finally, we note that the difference in the diabatic mass fluxes between the two assimilated meteorological analyses is much larger than the interannual variability in either. C1 NASA, Earth Sci Directorate, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Schoeberl, MR (reprint author), NASA, Earth Sci Directorate, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. EM schom@zephyr.gsfc.nasa.gov NR 44 TC 61 Z9 62 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 13 PY 2004 VL 109 IS D13 AR D13303 DI 10.1029/2004JD004525 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 839PR UT WOS:000222797500002 ER PT J AU Liu, QY Jiang, X Xie, SP Liu, WT AF Liu, QY Jiang, X Xie, SP Liu, WT TI A gap in the Indo-Pacific warm pool over the South China Sea in boreal winter: Seasonal development and interannual variability SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE Indo-Pacific warm pool; South China Sea; cold tongue ID SURFACE TEMPERATURE; GENERAL-CIRCULATION; OCEAN CIRCULATION; DYNAMICS; CLIMATE; ENSO; TOPEX/POSEIDON; EXTENSION; KUROSHIO; MONSOONS AB [1] The Indo-Pacific warm water pool in boreal winter shows a conspicuous gap over the South China Sea (SCS) where sea surface temperature (SST) is considerably lower than over the oceans both to the west and east. The formation mechanisms for the climatology and interannual variability of SCS SST in boreal winter are investigated using a suite of new satellite measurements. The winter SCS is divided into two parts by the axis of the maximum northeasterly monsoonal winds. The positive wind curl in the southeastern half of the ocean drives a cyclonic gyre circulation in the deep basin. As its western boundary current, an intense southward flow is found south of Vietnam on the continental slope separating the Sunda Shelf to the west and the deep SCS basin to the east. This slope current exceeds 0.5 m s(-1) in speed and advects cold water from the north. This cold advection results in a distinct cold tongue in the winter SST climatology. Both the slope current and the cold tongue are strongest in November to February. This winter cold tongue displays considerable interannual variability that is highly correlated with eastern equatorial Pacific SST. In an El Nino the winter monsoon weakens, causing the SCS ocean circulation to spin down. The reduced western boundary current and its thermal advection result in a warming in the SCS winter cold tongue. Both SST variance and its correlation with the El Nino-Southern Oscillation peak along the climatological cold tongue indicate that ocean dynamics are an important player in SCS climate variability. C1 Ocean Univ China, Phys Oceanog Lab, Qingdao 2666003, Peoples R China. Ocean Univ China, Ocean Atmosphere Interact & Climate Lab, Qingdao 2666003, Peoples R China. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Hawaii, SOEST, Int Pacific Res Ctr, Honolulu, HI 96822 USA. Univ Hawaii, Dept Meteorol, Honolulu, HI 96822 USA. RP Liu, QY (reprint author), Ocean Univ China, Phys Oceanog Lab, 5,Yushan Rd, Qingdao 2666003, Peoples R China. EM liuqy@ouc.edu.cn; xie@hawaii.edu; liu@pacific.jpl.nasa.gov RI Xie, Shang-Ping/C-1254-2009 OI Xie, Shang-Ping/0000-0002-3676-1325 NR 36 TC 98 Z9 116 U1 1 U2 16 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 JUL 13 PY 2004 VL 109 IS C7 AR C07012 DI 10.1029/2003JC002179 PG 10 WC Oceanography SC Oceanography GA 839PY UT WOS:000222798200001 ER PT J AU Glotch, TD Morris, RV Christensen, PR Sharp, TG AF Glotch, TD Morris, RV Christensen, PR Sharp, TG TI Effect of precursor mineralogy on the thermal infrared emission spectra of hematite: Application to Martian hematite mineralization SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE hematite; Mars; TES ID LEPIDOCROCITE GAMMA-FEOOH; GOETHITE ALPHA-FEOOH; PARTICLE-SIZE; CRYSTALLINE HEMATITE; SURFACE MATERIALS; TERRA-MERIDIANI; OLYMPIC DAM; MARS; SPECTROMETER; STABILITY AB [ 1] Observations from the Thermal Emission Spectrometer (TES) instrument aboard the Mars Global Surveyor (MGS) spacecraft led to the discovery of two isolated deposits of gray, crystalline hematite located in Meridiani Planum and Aram Chaos and several smaller deposits in Valles Marineris. Several pathways for formation of these hematite deposits have been proposed, involving both aqueous and nonaqueous processes. This work uses the precise shape and position of spectral features in the Martian hematite thermal emission spectrum to constrain hematite formation pathways. Thermal infrared emission spectra, X-ray powder diffraction patterns, Mossbauer spectra, and transmission electron microscope (TEM) photomicrographs were obtained for synthetic and natural hematite samples derived by ( 1) dehydroxylation of fine-grained goethite and ( 2) oxidation of magnetite. Collectively, the instrumental analyses show that the mineralogical composition and crystal morphology of precursor samples and the time and temperature conditions under which decomposition to hematite occur determine the crystallinity and crystal morphology of the hematite product. Comparison of laboratory and MGS-TES spectra shows that the Martian hematite spectra correspond closely with a synthetic hematite sample derived by pseudomorphic and topotactic dehydroxylation of goethite at 300 degreesC. Spectra of goethite-precursor samples dehydroxylated at higher temperatures provide increasingly poor fits. Spectra of hematite samples derived by high-temperature thermal oxidation of magnetite are also poorer fits to the Martian hematite spectrum. Thermal emission spectra of goethites heated at lower temperatures are characterized by the spectral signatures of both hematite and goethite and are not consistent with the Martian spectra. The characteristic that distinguishes the synthetic hematite sample with the Mars-like spectral signature from the other synthetic hematite samples is the high proportion of crystal surfaces that are crystallographic {001} faces ( c faces) for the former but not the latter. The high proportion of {001} face area results because the largest surface of the lath-shaped hematite particles is the ( 001) face, as determined by TEM. Thus a possible formation pathway for hematite in Meridiani Planum, Aram Chaos, and Valles Marineris is precipitation of goethite from aqueous solutions as lath-shaped crystals, possibly as a stain, cement, and/or massive deposit, followed by pseudomorphic and topotactic dehydroxylation to hematite at temperatures below similar to300 degreesC. C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. EM tglotch@asu.edu; richard.v.morris1@jsc.nasa.gov; phil.christensen@asu.edu; tom.sharp@asu.edu RI Glotch, Timothy/B-6829-2008 NR 52 TC 48 Z9 48 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD JUL 13 PY 2004 VL 109 IS E7 AR E07003 DI 10.1029/2003JE002224 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 839QF UT WOS:000222798900002 ER PT J AU Lefevre, F Lebonnois, S Montmessin, F Forget, F AF Lefevre, F Lebonnois, S Montmessin, F Forget, F TI Three-dimensional modeling of ozone on Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Martian atmosphere; ozone; atmospheric chemistry ID CROSS-SECTION MEASUREMENTS; HUBBLE-SPACE-TELESCOPE; THERMAL EMISSION SPECTROMETER; GENERAL-CIRCULATION MODEL; MARTIAN ATMOSPHERE; WATER-VAPOR; ULTRAVIOLET SPECTROMETER; OCCULTATION MEASUREMENTS; TEMPERATURE-DEPENDENCE; CARBON-DIOXIDE AB [ 1] We present the first three-dimensional model simulations of ozone on Mars. The model couples a state-of-the-art gas-phase photochemical package to the general circulation model developed at Laboratoire de Meteorologie Dynamique (LMD). The results do not contradict the classical picture of a global anticorrelation between the ozone (O-3) and water vapor columns. However, the quantitative approach shows significant departures from this relationship, related to substantial orbital variations in the O-3 vertical distribution. Over the period L-s = 180degrees - 330degrees, low-latitude to midlatitude O-3 is essentially confined below 20 km, has a weak diurnal cycle, and is largely modulated by topography. During the rest of the year (L-s = 330degrees - 180degrees) the model predicts the formation of an O-3 layer at 25 - 70 km altitude, characterized by nighttime densities about one order of magnitude larger than during the day. Throughout the year, high-latitude O-3 peaks near the surface and reaches maximum integrated amounts ( similar to 40 mm-atm) in the winter polar vortex, with considerable (30 to 50%) dynamically induced day-to-day variations. The most stringent comparison to date with O-3 observational data reveals contrasted results. A good quantitative agreement is found in the postperihelion period (L-s = 290degrees - 10degrees), but the model fails to reproduce O-3 columns as large as those measured near aphelion (L-s = 61degrees - 67degrees). Current uncertainties in absorption cross sections and gas-phase kinetics data do not seem to provide credible explanations to explain this discrepancy, which may suggest the existence of heterogeneous processes. C1 Inst Pierre Simon Laplace, Serv Aeron, F-75252 Paris 05, France. Inst Pierre Simon Laplace, Meteorol Dynam Lab, F-75252 Paris 05, France. NASA, Div Space Sci, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Inst Pierre Simon Laplace, Serv Aeron, 4 Pl Jussieu,Box 102, F-75252 Paris 05, France. EM franck.lefevre@aero.jussieu.fr; sebastien.lebonnois@lmd.jussieu.fr; fmontmessin@mail.arc.nasa.gov; francois.forget@lmd.jussieu.fr OI LEBONNOIS, SEBASTIEN/0000-0002-2390-8164 NR 77 TC 74 Z9 75 U1 0 U2 2 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 13 PY 2004 VL 109 IS E7 AR E07004 DI 10.1029/2004JE002268 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 839QF UT WOS:000222798900003 ER PT J AU Jain, M Karan, NK Katiyar, RS Bhalla, AS Miranda, FA Van Keuls, FW AF Jain, M Karan, NK Katiyar, RS Bhalla, AS Miranda, FA Van Keuls, FW TI Pb0.3Sr0.7TiO3 thin films for high-frequency phase shifter applications SO APPLIED PHYSICS LETTERS LA English DT Article ID CAPACITORS; DEPOSITION AB Pb0.3Sr0.7TiO3 (PST30) thin films were synthesized on platinized silicon (Pt/Si) and lanthanum aluminate (LAO) substrates using chemical solution deposition technique. The films on LAO substrate were highly (100) oriented, whereas the films on Pt/Si substrate were polycrystalline. The low dielectric loss in the PST30/LAO films makes them attractive for fabricating tunable dielectric devices. An eight-element coupled microstrip phase shifter was fabricated on PST30/LAO film and tested in the frequency range similar to15-17 GHz. The maximum figure of merit (kappa=phase shift per dB loss) of similar to56degrees/dB was obtained for PST30 film, which was better than commonly observed value in pure barium strontium titanate films: This makes PST30 a potential candidate material for further investigations for microwave applications. (C) 2004 American Institute of Physics. C1 Univ Puerto Rico, Dept Phys, San Juan, PR 00931 USA. Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. RP Jain, M (reprint author), Univ Puerto Rico, Dept Phys, San Juan, PR 00931 USA. EM rkatiyar@rrpac.upr.clu.edu OI Jain, Menka/0000-0002-2264-6895 NR 21 TC 42 Z9 43 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 12 PY 2004 VL 85 IS 2 BP 275 EP 277 DI 10.1063/1.17.71459 PG 3 WC Physics, Applied SC Physics GA 839KP UT WOS:000222784300039 ER PT J AU Pak, S Jaffe, DT Stacey, GJ Bradford, CM Klumpe, EW Keller, LD AF Pak, S Jaffe, DT Stacey, GJ Bradford, CM Klumpe, EW Keller, LD TI Near-infrared molecular hydrogen emission from the central regions of galaxies: Regulated physical conditions in the interstellar medium SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : individual (M82, NGC 253, NGC 6946, IC 342); galaxies : ISM; galaxies : spiral; galaxies : starburst; infrared : ISM; ISM : lines and bands ID STAR-FORMING GALAXIES; INNER 400 PARSECS; 158 MICRON C; PHOTODISSOCIATION REGIONS; LINE EMISSION; H-2 EMISSION; NUCLEAR STARBURST; IC 342; ULTRALUMINOUS GALAXIES; BRIGHT GALAXIES AB The central regions of many interacting and early-type spiral galaxies are actively forming stars. This process affects the physical and chemical properties of the local interstellar medium, as well as the evolution of the galaxies. We observed near-infrared H-2 emission lines: v = 1-0 S(1), 3-2 S(3), 1-0 S(0), and 2-1 S(1) from the central similar to1 kpc regions of the archetypical starburst galaxies M82 and NGC 253 and the less dramatic but still vigorously star-forming galaxies NGC 6946 and IC 342. Like the far-infrared continuum luminosity, the near-infrared H-2 emission luminosity can directly trace the amount of star formation activity because the H-2 emission lines arise from the interaction between hot and young stars and nearby neutral clouds. The observed H-2 line ratios show that both thermal excitation and nonthermal excitation are responsible for the emission lines but that the great majority of the near-infrared H-2 line emission in these galaxies arises from energy states excited by ultraviolet fluorescence. The derived physical conditions, e.g., far-ultraviolet radiation field and gas density, from [C II] and [O I] lines and far-infrared continuum observations when used as inputs to photodissociation models also explain the luminosity of the observed H-2 1-0 S(1) line. The ratio of the H-2 1-0 S(1) line to far-IR continuum luminosity is remarkably constant over a broad range of galaxy luminosities: L-H2/L-FIR similar or equal to 10(-5), in normal late-type galaxies ( including the Galactic center), in nearby starburst galaxies, and in luminous IR galaxies (LIRGs: L-FIR > 10(11) L.). Examining this constant ratio in the context of photodissociation region models, we conclude that it implies that the strength of the incident UV field on typical molecular clouds follows the gas density at the cloud surface. C1 Korea Astron Observ, Taejon 305348, South Korea. Univ Texas, Dept Astron, Austin, TX 78712 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Middle Tennessee State Univ, Dept Phys & Astron, Murfreesboro, TN 37132 USA. Ithaca Coll, Dept Phys, Ithaca, NY 14850 USA. RP Korea Astron Observ, 61-1 Whaam Dong, Taejon 305348, South Korea. EM soojong@kao.re.kr RI Pak, Soojong/E-2360-2013; OI Pak, Soojong/0000-0002-2548-238X NR 102 TC 7 Z9 7 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2004 VL 609 IS 2 BP 692 EP 709 DI 10.1086/421233 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 835BZ UT WOS:000222456200018 ER PT J AU Fynbo, JPU Sollerman, J Hjorth, J Grundahl, F Gorosabel, J Weidinger, M Moller, P Jensen, BL Vreeswijk, PM Fransson, C Ramirez-Ruiz, E Jakobsson, P Jorgensen, SF Vinter, C Andersen, MI Ceron, JMC Castro-Tirado, AJ Fruchter, AS Greiner, J Kouveliotou, C Levan, A Klose, S Masetti, N Pedersen, H Palazzi, E Pian, E Rhoads, J Rol, E Sekiguchi, T Tanvir, NR Tristram, P Postigo, AD Wijers, RAMJ van den Heuvel, E AF Fynbo, JPU Sollerman, J Hjorth, J Grundahl, F Gorosabel, J Weidinger, M Moller, P Jensen, BL Vreeswijk, PM Fransson, C Ramirez-Ruiz, E Jakobsson, P Jorgensen, SF Vinter, C Andersen, MI Ceron, JMC Castro-Tirado, AJ Fruchter, AS Greiner, J Kouveliotou, C Levan, A Klose, S Masetti, N Pedersen, H Palazzi, E Pian, E Rhoads, J Rol, E Sekiguchi, T Tanvir, NR Tristram, P Postigo, AD Wijers, RAMJ van den Heuvel, E TI On the afterglow of the X-ray flash of 2003 July 23: Photometric evidence for an off-axis gamma-ray burst with an associated supernova? SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; gamma rays : bursts; supernovae : general; X-rays : individual (XRF 030723) ID 25 APRIL 1998; LIGHT CURVES; HOST GALAXY; OPTICAL PHOTOMETRY; RELATIVISTIC JETS; DUST ECHOES; SPECTROSCOPY; SPECTRA; GRB-000926; DISCOVERY AB We present optical and near-infrared follow-up observations of the X-ray flash (XRF) of 2003 July 23. Our observations in the R band cover the temporal range from 4.2 hr to 64 days after the high-energy event. We also present the results of multicolor imaging extending to the K band on three epochs. The light curve of the R-band afterglow the first week after the burst is similar to the light curve for long-duration gamma-ray bursts (GRBs), i.e., a broken power law with a late time slope of alpha approximate to 2.0 (F(nu) proportional to t(-alpha)). Furthermore, the spectral energy distribution (SED) has a power-law (F(nu) proportional to nu(-beta)) shape with slope beta approximate to 1.0. However, the decay slope at t < 1 day is shallow, consistent with zero. This is in qualitative agreement with the prediction that XRFs are off-axis classical GRBs. After the first week there is a strong bump in the light curve, which peaks at around 16 days. The SED after the peak becomes significantly redder. We discuss the possible interpretations of this bump and conclude that an underlying supernova is the most likely explanation since no other model appears consistent with the evolution of the SED. Finally, we present deep spectroscopy of the burst both in the afterglow and in the bump phase. A firm upper limit of z = 2.3 is placed on the redshift of XRF 030723 from the lack of Ly alpha forest lines in the spectrum of the afterglow. The lack of significant absorption and emission lines in either of the two spectra excludes a spectroscopic redshift determination. C1 Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark. Univ Copenhagen, Astron Observ, Niels Bohr Inst, DK-2100 Copenhagen O, Denmark. AlbaNova, Dept Astron, Stockholm Observ, S-10691 Stockholm, Sweden. CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain. Space Telescope Sci Inst, Baltimore, MD 21218 USA. European So Observ, D-85748 Garching, Germany. European So Observ, Santiago 19, Chile. Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. NASA, Univ Res Assoc, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Leicester, Dept Phys & Astron, Xray Astron Grp, Leicester LE1 7RH, Leics, England. Thuringer Landessternwarte Tautenburg, D-07778 Tautenburg, Germany. CNR, IASF, Sez Bologna, I-40129 Bologna, Italy. Osserv Astron Trieste, INAF, I-34131 Trieste, Italy. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Nagoya Univ, Solar Terr Environm Lab, Nagoya, Aichi 4648601, Japan. Univ Hertfordshire, Dept Phys Sci, Hatfield AL10 9AB, Herts, England. Univ Canterbury, Mt John Observ, Lake Tekapo, New Zealand. RP Fynbo, JPU (reprint author), Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark. RI Hjorth, Jens/M-5787-2014; Jensen, Brian Lindgren/E-1275-2015; Jakobsson, Pall/L-9950-2015; Palazzi, Eliana/N-4746-2015; OI Hjorth, Jens/0000-0002-4571-2306; Jensen, Brian Lindgren/0000-0002-0906-9771; Jakobsson, Pall/0000-0002-9404-5650; Wijers, Ralph/0000-0002-3101-1808; Palazzi, Eliana/0000-0002-8691-7666; Castro-Tirado, A. J./0000-0003-2999-3563; Sollerman, Jesper/0000-0003-1546-6615; de Ugarte Postigo, Antonio/0000-0001-7717-5085; Masetti, Nicola/0000-0001-9487-7740; Pian, Elena/0000-0001-8646-4858 NR 90 TC 77 Z9 77 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2004 VL 609 IS 2 BP 962 EP 971 DI 10.1086/421260 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 835BZ UT WOS:000222456200037 ER PT J AU Gogus, E Finger, MH Kouveliotou, C Woods, PM Patel, SK Rupen, M Swank, JH Markwardt, CB van der Klis, M AF Gogus, E Finger, MH Kouveliotou, C Woods, PM Patel, SK Rupen, M Swank, JH Markwardt, CB van der Klis, M TI Long-term spectral and timing behavior of the black hole candidate XTE J1908+094 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; stars : individual (XTE J1908+094) ID QUASI-PERIODIC OSCILLATION; NEAR-INFRARED COUNTERPART; X-RAY VARIABILITY; XTE J1550-564; IRON EMISSION; 4U 1630-47; OUTBURST; STATES; MODEL; J1908+094 AB We present the long-term X-ray light curves and detailed spectral and timing analyses of XTE J1908+094 using the Rossi X-Ray Timing Explorer Proportional Counter Array observations covering two outbursts in 2002 and early 2003. At the onset of the first outburst, the source was found in a spectrally low/hard state lasting for similar to 40 days, followed by a 3 day long transition to the high/soft state. The source flux ( in 2 - 10 keV) reached similar to 100 mcrab on 2002 April 6, then decayed rapidly. In power spectra, we detect strong band-limited noise and varying low-frequency quasi-periodic oscillations that evolved from similar to 0.5 to similar to 5 Hz during the initial low/hard state of the source. We find that the second outburst closely resembled the spectral evolution of the first. The X-ray transient's overall outburst characteristics led us to classify XTE J1908+094 as a black hole candidate. Here we also derive precise X-ray position of the source using Chandra observations that were performed during the decay phase of the first outburst and following the second outburst. C1 Sabanci Univ, TR-34956 Istanbul, Turkey. Univ Space Res Assoc, Columbia, MD 21044 USA. Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Univ Amsterdam, CHEAF, NL-1098 SJ Amsterdam, Netherlands. RP Gogus, E (reprint author), Sabanci Univ, TR-34956 Istanbul, Turkey. EM ersing@sabanciuniv.edu RI Swank, Jean/F-2693-2012 NR 29 TC 7 Z9 7 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2004 VL 609 IS 2 BP 977 EP 987 DI 10.1086/421255 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 835BZ UT WOS:000222456200039 ER PT J AU Rosi, M Bauschlicher, CW Bakes, ELO AF Rosi, M Bauschlicher, CW Bakes, ELO TI The stability of C6H6+2 : The implication for polycyclic aromatic hydrocarbon dications SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrochemistry; ISM : molecules; molecular processes ID THEORETICAL INFRARED-SPECTRA; INTERSTELLAR-MEDIUM; BASIS-SETS; EMISSION; MOLECULES; CATIONS; PAHS; PHOTODESTRUCTION; SPECTROSCOPY; NAPHTHALENE AB The fragmentation pathways of C6H6+2 are studied using density functional theory. All of the transition states that were found, excluding the rearrangement to the C-5v structure, are significantly above the six-membered ring structure. This is consistent with the soft ionization experiments that find mostly dication production instead of fragmentation. Since the C-5v structure is probably of limited importance for multiple-ring polycyclic aromatic hydrocarbons, the computed barriers suggest that Coulomb explosion is not a significant channel under most astrophysical conditions, and therefore, the dications are long-lived and should be considered in modeling of the interstellar medium. C1 Univ Perugia, Dept Chem, CNR, ISTM, I-06100 Perugia, Italy. NASA, Ames Res Ctr, Space Technol Div, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, SETI, Moffett Field, CA 94035 USA. RP Rosi, M (reprint author), Univ Perugia, Dept Chem, CNR, ISTM, I-06100 Perugia, Italy. EM charles.w.bauschlicher@nasa.gov RI Rosi, Marzio/L-5748-2015 OI Rosi, Marzio/0000-0002-1264-3877 NR 31 TC 16 Z9 16 U1 1 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 10 PY 2004 VL 609 IS 2 BP 1192 EP 1196 DI 10.1086/421340 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 835BZ UT WOS:000222456200058 ER PT J AU Eriksen, HK Hansen, FK Banday, AJ Gorski, KM Lilje, PB AF Eriksen, HK Hansen, FK Banday, AJ Gorski, KM Lilje, PB TI Asymmetries in the cosmic microwave background anisotropy field (vol 605, pg 14, 2004) SO ASTROPHYSICAL JOURNAL LA English DT Correction C1 Univ Oslo, Inst Theoret Astrophys, N-0316 Oslo, Norway. Univ Roma Tor Vergata, Dipartimento Fis, I-00173 Rome, Italy. Max Planck Inst Astrophys, D-85741 Garching, Germany. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Eriksen, HK (reprint author), Univ Oslo, Inst Theoret Astrophys, N-0316 Oslo, Norway. RI Lilje, Per/A-2699-2012 NR 1 TC 121 Z9 121 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2004 VL 609 IS 2 BP 1198 EP 1199 DI 10.1086/421972 PN 1 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 835BZ UT WOS:000222456200060 ER PT J AU McIntosh, SW Fleck, B Tarbell, TD AF McIntosh, SW Fleck, B Tarbell, TD TI Chromospheric oscillations in an equatorial coronal hole SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : atmospheric motions; Sun : chromosphere ID SOLAR CHROMOSPHERE; TRANSITION REGION; TRACE; DYNAMICS; SOHO; SUN AB We report phase-difference and travel-time analyses of propagating chromospheric oscillations in and around an equatorial coronal hole as observed by TRACE. Our results suggest a significant change in atmospheric conditions at the base of the chromosphere inside the coronal hole relative to its boundary and quiet-Sun regions. C1 Univ Space Res Assoc, Cooperat Program Space Sci, Seabrook, MD 20706 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, European Space Agcy, Res & Sci Support Dept, Greenbelt, MD 20771 USA. Lockheed Martin, Solar & Astrophys Lab, Palo Alto, CA 94304 USA. RP Univ Space Res Assoc, Cooperat Program Space Sci, 7501 Forbes Blvd,Suite 206, Seabrook, MD 20706 USA. EM scott@grace.nascom.nasa.gov; bfleck@esa.nascom.nasa.gov; tarbell@lmsal.com RI Fleck, Bernhard/C-9520-2012 NR 17 TC 15 Z9 15 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2004 VL 609 IS 2 BP L95 EP L98 DI 10.1086/422748 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 835CA UT WOS:000222456300013 ER PT J AU Tang, YH Carmichael, GR Horowitz, LW Uno, I Woo, JH Streets, DG Dabdub, D Kurata, G Sandu, A Allan, J Atlas, E Flocke, F Huey, LG Jakoubek, RO Millet, DB Quinn, PK Roberts, JM Worsnop, DR Goldstein, A Donnelly, S Schauffler, S Stroud, V Johnson, K Avery, MA Singh, HB Apel, EC AF Tang, YH Carmichael, GR Horowitz, LW Uno, I Woo, JH Streets, DG Dabdub, D Kurata, G Sandu, A Allan, J Atlas, E Flocke, F Huey, LG Jakoubek, RO Millet, DB Quinn, PK Roberts, JM Worsnop, DR Goldstein, A Donnelly, S Schauffler, S Stroud, V Johnson, K Avery, MA Singh, HB Apel, EC TI Multiscale simulations of tropospheric chemistry in the eastern Pacific and on the US West Coast during spring 2002 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE chemical transport model; nesting simulation; atmospheric photochemistry ID TRACE-P EXPERIMENT; CHEMICAL-TRANSPORT MODEL; GAS-AEROSOL EQUILIBRIUM; NORTH-AMERICA; AIR-POLLUTION; EMISSIONS; OZONE; ASIA; BIOMASS; DISTRIBUTIONS AB [ 1] Regional modeling analysis for the Intercontinental Transport and Chemical Transformation 2002 (ITCT 2K2) experiment over the eastern Pacific and U. S. West Coast is performed using a multiscale modeling system, including the regional tracer model Chemical Weather Forecasting System (CFORS), the Sulfur Transport and Emissions Model 2003 (STEM-2K3) regional chemical transport model, and an off-line coupling with the Model of Ozone and Related Chemical Tracers ( MOZART) global chemical transport model. CO regional tracers calculated online in the CFORS model are used to identify aircraft measurement periods with Asian influences. Asian-influenced air masses measured by the National Oceanic and Atmospheric Administration (NOAA) WP-3 aircraft in this experiment are found to have lower DeltaAcetone/DeltaCO, DeltaMethanol/DeltaCO, and DeltaPropane/DeltaEthyne ratios than air masses influenced by U. S. emissions, reflecting differences in regional emission signals. The Asian air masses in the eastern Pacific are found to usually be well aged (> 5 days), to be highly diffused, and to have low NOy levels. Chemical budget analysis is performed for two flights, and the O-3 net chemical budgets are found to be negative ( net destructive) in the places dominated by Asian influences or clear sites and positive in polluted American air masses. During the trans-Pacific transport, part of gaseous HNO3 was converted to nitrate particle, and this conversion was attributed to NOy decline. Without the aerosol consideration, the model tends to overestimate HNO3 background concentration along the coast region. At the measurement site of Trinidad Head, northern California, high-concentration pollutants are usually associated with calm wind scenarios, implying that the accumulation of local pollutants leads to the high concentration. Seasonal variations are also discussed from April to May for this site. A high-resolution nesting simulation with 12-km horizontal resolution is used to study the WP-3 flight over Los Angeles and surrounding areas. This nested simulation significantly improved the predictions for emitted and secondary generated species. The difference of photochemical behavior between the coarse (60-km) and nesting simulations is discussed and compared with the observation. C1 Univ Iowa, Ctr Global & Reg Environm Rs, Iowa City, IA 52242 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. Kyushu Univ, Res Inst Appl Mech, Fukuoka, Japan. Argonne Natl Lab, Decis & Informat Sci Div, Argonne, IL USA. Univ Calif Irvine, Dept Mech & Aerosp Engn, Irvine, CA 92717 USA. Toyohashi Univ Technol, Dept Ecol Engn, Toyohashi, Aichi, Japan. Virginia Polytech Inst & State Univ, Dept Comp Sci, Blacksburg, VA 24061 USA. Univ Manchester, Inst Sci & Technol, Dept Phys, Manchester M60 1QD, Lancs, England. Natl Ctr Atmospher Res, Boulder, CO USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Aerodyne Res Inc, Billerica, MA 01821 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Univ Iowa, Ctr Global & Reg Environm Rs, 402 IATL, Iowa City, IA 52242 USA. EM ytang@cgrer.uiowa.edu; gcarmich@icaen.uiowa.edu; larry.horowitz@noaa.gov; iuno@riam.kyushu-u.ac.jp; woojh21@cgrer.uiowa.edu; dstreets@anl.gov; ddabdub@uci.edu; kurata@eco.tut.ac.jp; asandu@cs.vt.edu; james.allan@physics.org; atlas@acd.ucar.edu; ffl@acd.ucar.edu; greg.huey@eas.gatech.edu; jakoubek@al.noaa.gov; dylan@atmos.berkeley.edu; quinn@pmel.noaa.gov; jr@al.noaa.gov; worsnop@aerodyne.com; ahg@nature.berkeley.edu; donnelly@ucar.edu; sues@acd.ucar.edu; cstroud@acd.ucar.edu; kristen.johnson@colorado.edu; m.a.avery@larc.nasa.gov; hanwant.b.singh@nasa.gov; apel@acd.ucar.edu RI Roberts, James/A-1082-2009; Worsnop, Douglas/D-2817-2009; Uno, Itsushi/B-5952-2011; Goldstein, Allen/A-6857-2011; Millet, Dylan/G-5832-2012; Allan, James/B-1160-2010; Horowitz, Larry/D-8048-2014; Kyushu, RIAM/F-4018-2015; Atlas, Elliot/J-8171-2015; U-ID, Kyushu/C-5291-2016; Tang, Youhua/D-5205-2016; Quinn, Patricia/R-1493-2016 OI Roberts, James/0000-0002-8485-8172; Streets, David/0000-0002-0223-1350; Worsnop, Douglas/0000-0002-8928-8017; Goldstein, Allen/0000-0003-4014-4896; Allan, James/0000-0001-6492-4876; Horowitz, Larry/0000-0002-5886-3314; Tang, Youhua/0000-0001-7089-7915; Quinn, Patricia/0000-0003-0337-4895 NR 40 TC 20 Z9 20 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 9 PY 2004 VL 109 IS D23 AR D23S11 DI 10.1029/2004JD004513 PG 35 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 837SG UT WOS:000222655800003 ER PT J AU Brian, AW Stofan, ER Guest, JE Smrekar, SE AF Brian, AW Stofan, ER Guest, JE Smrekar, SE TI Laufey Regio: a newly discovered topographic rise on Venus SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE topographic rises; Venus; volcanism ID IMPACT CRATER DENSITIES; BETA-REGIO; GLOBAL DISTRIBUTION; CONTINENTAL LITHOSPHERE; ISOSTATIC COMPENSATION; MAGELLAN OBSERVATIONS; ELASTIC THICKNESS; MANTLE DYNAMICS; HOTSPOT SWELLS; LARGE VOLCANOS AB [1] Laufey Regio is a 0.5 km high, elongate topographic rise, measuring 1000 by 2000 km, located within northern Navka Planitia, Venus. It is dominated by two large volcanoes, Var and Atanua Montes, and numerous coronae with associated flow deposits. The area has been geologically mapped, showing that large-scale edifice formation focused at Var and Atanua Montes and overlapped in time with the formation of smaller coronae. Several coronae and volcanoes have had complex and protracted histories with multiple episodes of volcanism and tectonism, supporting a nondirectional history for this region. The broad topography of the rise is surrounded by a concentric set of wrinkle ridges interpreted to have formed after the onset of centralized volcanism. Admittance studies indicate both bottom and top loading, but lithospheric parameters are not well constrained. Top-loading models give a range of 0 - 48 km for elastic thickness (T(e)) and 35 - 115 km for crustal thickness. We interpret the T(e) range as most likely indicating isostatic compensation. Bottom-loading models yield lower bounds of 30 - 75 km for T(e) and 32 - 74 km for the apparent depth of compensation ( ADC). The combination of the large T(e) and low topography indicates that the plume is no longer active. Bottom loading and a small ADC may indicate that a layer of low-density residuum, produced by pressure release melting in the now extinct plume, is partially supporting the topography. On the basis of its broad, regional topography, abundant volcanism, and gravity signature, we interpret Laufey to be a volcano-dominated rise in a late stage of evolution. C1 UCL, Dept Earth Sci, Planetary Geol Grp, London WC1A 6BT, England. Proxemy Res, Laytonville, MD USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Brian, AW (reprint author), UCL, Dept Earth Sci, Planetary Geol Grp, Gower St, London WC1A 6BT, England. EM awb@star.ucl.ac.uk; ssmrekar@jpl.nasa.gov NR 68 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 JUL 9 PY 2004 VL 109 IS E7 AR E07002 DI 10.1029/2002JE002010 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 837SQ UT WOS:000222656800001 ER PT J AU Jacobson, T Liberati, S Mattingly, D Stecker, FW AF Jacobson, T Liberati, S Mattingly, D Stecker, FW TI New limits on Planck scale Lorentz violation in QED SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM-GRAVITY; INVARIANCE; TESTS; LIGHT; SPEED; BURST AB Constraints on possible Lorentz symmetry violation (LV) of order E/M-Planck for electrons and photons in the framework of effective field theory (EFT) are discussed. Using (i) the report of polarized MeV emission from GRB021206 and (ii) the absence of vacuum Cerenkov radiation from synchrotron electrons in the Crab Nebula, we improve previous bounds by 10(-10) and 10(-2), respectively. We also show that the LV parameters for positrons and electrons are different, discuss electron helicity decay, and investigate how prior constraints are modified by the relations between LV parameters implied by EFT. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RI Stecker, Floyd/D-3169-2012; OI Liberati, Stefano/0000-0002-7632-7443 NR 25 TC 114 Z9 114 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 9 PY 2004 VL 93 IS 2 AR 021101 DI 10.1103/PhysRevLett.93.021101 PG 4 WC Physics, Multidisciplinary SC Physics GA 836CF UT WOS:000222532100013 PM 15323893 ER PT J AU Strekalov, D Matsko, AB Yu, N Maleki, L AF Strekalov, D Matsko, AB Yu, N Maleki, L TI Observation of light dragging in a rubidium vapor cell SO PHYSICAL REVIEW LETTERS LA English DT Article ID GROUP-VELOCITY; ATOMIC GAS; SLOW; ULTRASLOW; MEDIA AB We report on the experimental demonstration of the light dragging effect due to atomic motion in a rubidium vapor cell. We find that the minimum group velocity is achieved for light redshifted from the center of the atomic resonance and that the value of this shift increases with decreasing group velocity, in agreement with the theoretical predictions by Kocharovskaya, Rostovtsev, and Scully [Phys. Rev. Lett. 86, 628 (2001)]. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Matsko, Andrey/A-1272-2007 NR 24 TC 13 Z9 13 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 9 PY 2004 VL 93 IS 2 AR 023601 DI 10.1103/PhysRevLett.93.023601 PG 4 WC Physics, Multidisciplinary SC Physics GA 836CF UT WOS:000222532100035 PM 15323915 ER PT J AU Brownlee, DE AF Brownlee, DE TI Surface of young Jupiter family comet 81 P/Wild 2: view from the Stardust spacecraft (vol 304, pg 1764, 2004) SO SCIENCE LA English DT Correction C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUL 9 PY 2004 VL 305 IS 5681 BP 180 EP 180 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 835QQ UT WOS:000222501000022 ER PT J AU Wright, TJ Parsons, B England, PC Fielding, EJ AF Wright, TJ Parsons, B England, PC Fielding, EJ TI InSAR observations of low slip rates on the major faults of western Tibet SO SCIENCE LA English DT Article ID CONTINENTAL DEFORMATION; CRUSTAL DEFORMATION; STRAIN ACCUMULATION; EASTERN TIBET; SYSTEM; CALIFORNIA; MODEL; CHINA; ASIA; EARTHQUAKE AB Two contrasting views of the active deformation of Asia dominate the debate about how continents deform: (i) The deformation is primarily localized on major faults separating crustal blocks or (ii) deformation is distributed throughout the continental lithosphere. In the first model, western Tibet is being extruded eastward between the major faults bounding the region. Surface displacement measurements across the western Tibetan plateau using satellite radar interferometry (InSAR) indicate that slip rates on the Karakoram and Altyn Tagh faults are lower than would be expected for the extrusion model and suggest a significant amount of internal deformation in Tibet. C1 Univ Oxford, Dept Earth Sci, COMET, Oxford OX1 3PR, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Cambridge, Dept Earth Sci, Cambridge CB2 1TN, England. RP Univ Oxford, Dept Earth Sci, COMET, Oxford OX1 3PR, England. EM tim.wright@earth.ox.ac.uk RI Wright, Tim/A-5892-2011; Parsons, Barry/K-4716-2012; NCEO, COMET+`/A-3443-2013; England, Philip/A-1920-2010; Fielding, Eric/A-1288-2007 OI Wright, Tim/0000-0001-8338-5935; England, Philip/0000-0002-9024-8901; Fielding, Eric/0000-0002-6648-8067 NR 32 TC 152 Z9 175 U1 3 U2 27 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD JUL 9 PY 2004 VL 305 IS 5681 BP 236 EP 239 DI 10.1126/science.1096388 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 835QQ UT WOS:000222501000050 PM 15247476 ER PT J AU Hill, CJ Wong, CM Yang, B Yang, RQ AF Hill, CJ Wong, CM Yang, B Yang, RQ TI Type-II interband cascade lasers emitting at wavelengths beyond 5.1 mu m SO ELECTRONICS LETTERS LA English DT Article ID CONTINUOUS-WAVE OPERATION; ROOM-TEMPERATURE AB Type-II interband cascade lasers have been demonstrated at emission wavelengths longer than 5.1 mum at temperatures up to 163 and 240K in continuous wave and pulsed modes, respectively. The emission wavelengths are the longest attained among III-V interband diode lasers. The threshold current density is as low as 36 A/cm(2) at 80K. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hill, CJ (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JUL 8 PY 2004 VL 40 IS 14 BP 878 EP 879 DI 10.1049/el:20040529 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 841IE UT WOS:000222922700025 ER PT J AU Moore, KG Clarke, AD Kapustin, VN McNaughton, C Anderson, BE Winstead, EL Weber, R Ma, Y Lee, YN Talbot, R Dibb, J Anderson, T Doherty, S Covert, D Rogers, D AF Moore, KG Clarke, AD Kapustin, VN McNaughton, C Anderson, BE Winstead, EL Weber, R Ma, Y Lee, YN Talbot, R Dibb, J Anderson, T Doherty, S Covert, D Rogers, D TI A comparison of similar aerosol measurements made on the NASA P3-B, DC-8, and NSFC-130 aircraft during TRACE-P and ACE-Asia SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosols; special field campaigns; instrument comparison ID OPTICAL-PROPERTIES; LIGHT-ABSORPTION; PARTICLES; POLLUTION; TRANSPORT; AIRBORNE; CARBON; SIZE; TROPOSPHERE; RADIATION AB Two major aircraft experiments occurred off the Pacific coast of Asia during spring 2001: the NASA sponsored Transport and Chemical Evolution over the Pacific (TRACE-P) and the National Science Foundation (NSF) sponsored Aerosol Characterization Experiment-Asia (ACE-Asia). Both experiments studied emissions from the Asian continent (biomass burning, urban/industrial pollution, and dust). TRACE-P focused on trace gases and aerosol during March/April and was based primarily in Hong Kong and Yokota Air Force Base, Japan, and involved two aircraft: the NASA DC-8 and the NASA P3-B. ACE-Asia focused on aerosol and radiation during April/May and was based in Iwakuni Marine Corps Air Station, Japan, and involved the NSF C-130. This paper compares aerosol measurements from these aircraft including aerosol concentrations, size distributions (and integral properties), chemistry, and optical properties. Best overall agreement (generally within RMS instrumental uncertainty) was for physical properties of the submircron aerosol, including condensation nuclei concentrations, scattering coefficients, and differential mobility analyzer and optical particle counter (OPC) accumulation mode size distributions. Larger differences (typically outside of the RMS uncertainty) were often observed for parameters related to the supermicron aerosols (total scattering and absorption coefficients, coarse mode Forward Scattering Spectrometer Probe and OPC size distributions/integral properties, and soluble chemical species usually associated with the largest particles, e.g., Na+, Cl-, Ca2+, and Mg2+), where aircraft sampling is more demanding. Some of the observed differences reflect different inlets ( e. g., low-turbulence inlet enhancement of coarse mode aerosol), differences in sampling lines, and instrument configuration and design. Means and variances of comparable measurements for horizontal legs were calculated, and regression analyses were performed for each platform and allow for an assessment of instrument performance. These results provide a basis for integrating aerosol data from these aircraft platforms for both the TRACE-P and ACE-Asia experiments. C1 Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. NASA, Chem & Dynam Branch, Div Atmospher Sci, Langley Res Ctr, Hampton, VA 23681 USA. NASA, GATS Inc, Langley Res Ctr, Hampton, VA 23681 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Natl Ctr Atmospher Res, RAF, Broomfield, CO 80021 USA. RP Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, 1000 Pope Rd, Honolulu, HI 96822 USA. EM kmoore@soest.hawaii.edu; tclarke@soest.hawaii.edu; kapustin@soest.hawaii.edu; cameronm@soest.hawaii.edu; b.e.anderson@larc.nasa.gov; e.l.winstead@larc.nasa.gov; rweber@eas.gatech.edu; yma@eas.gatech.edu; ynlee@bnl.gov; robert.talbot@unh.edu; jack.dibb@unh.edu; tadand@atmos.washington.edu; sarahd@atmos.washington.edu; dcovert@u.washington.edu; dcrogers@ucar.edu RI Doherty, Sarah/D-5592-2015; Lee, Yongjae/K-6566-2016 OI Doherty, Sarah/0000-0002-7796-6968; NR 43 TC 15 Z9 15 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 JUL 8 PY 2004 VL 109 IS D15 AR D15S15 DI 10.1029/2003JD003543 PG 35 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 837SA UT WOS:000222655100001 ER PT J AU Ofman, L AF Ofman, L TI Three-fluid model of the heating and acceleration of the fast solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE Alfven waves; coronal holes; acceleration and heating; three-fluid model ID CORONAL LOOP OSCILLATIONS; AMPLITUDE ALFVEN WAVES; MHD TURBULENCE; INNER CORONA; MINOR IONS; HOLES; TEMPERATURE; ULYSSES; PLASMA; DRIVEN AB [1] A new three-fluid, two-dimensional, wave-driven model that includes, for the first time, heat conduction, viscous, and resistive dissipation for protons and electrons in two-dimensional coronal hole is presented. The fast solar wind model includes electron, proton, and He++ or O5+ ion fluids. The heating of the solar wind plasma due to MHD waves is modeled as follows: A broadband spectrum of low-frequency Alfven waves is launched from the base of the corona. The waves deposit momentum and heat into the plasma to produce the fast solar wind. The values of the resistivity and shear viscosity coefficients required to produce the hot and fast solar wind consistent with observations are orders of magnitude larger than classical values. An empirical heating term that represents the contribution of additional heating processes, such as resonant heating by ion cyclotron waves, is included for the heavy ions and for protons in three out of four cases in the present study. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. EM leon.ofman@gsfc.nasa.gov NR 52 TC 30 Z9 30 U1 2 U2 8 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 8 PY 2004 VL 109 IS A7 AR A07102 DI 10.1029/2003JA010221 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 837SU UT WOS:000222657200003 ER PT J AU Ostgaard, N Mende, SB Frey, HU Immel, TJ Frank, LA Sigwarth, JB Stubbs, TJ AF Ostgaard, N Mende, SB Frey, HU Immel, TJ Frank, LA Sigwarth, JB Stubbs, TJ TI Interplanetary magnetic field control of the location of substorm onset and auroral features in the conjugate hemispheres SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE substorm onset; conjugate; aurora; IMF; asymmetry; nightside reconnection ID DAWN-DUSK ASYMMETRY; Y-COMPONENT; SOLAR-WIND; MAGNETOSPHERE; IMF; MODEL; POINTS; ARCS AB [1] During 2001 and 2002, when the Imager for Magnetopause-to-Aurora Global Exploration ( IMAGE) satellite had its apogee in the Northern Hemisphere and the Polar spacecraft, owing to the apsidal precession of its orbit, reached higher altitudes in the Southern Hemisphere, the two spacecraft offered a unique opportunity to study the aurora in the conjugate hemispheres simultaneously. Owing to the large fields of view of the Polar Visible Imaging System ( VIS) Earth camera and the IMAGE-FUV instruments, substorms and auroral features were imaged on a global scale in both hemispheres. We have identified five substorm onsets and several auroral features that can be unambiguously identified and compared in the two hemispheres. When mapped onto apex coordinates in the two hemispheres, we find that substorm onset locations and auroral features are usually not symmetric. The longitudinal displacement in one hemisphere compared with the other can be as much as 1.5 hours of local time ( similar to 1500 km). For southward interplanetary magnetic field ( IMF) the hemispherical asymmetry (DeltaMLT) is strongly correlated with the IMF clock angle (theta(C)) and a linear fit, DeltaMLT = - 0.017theta(C) + 3.44, gives a correlation coefficient of 0.83 with a mean deviation of 0.4DeltaMLT. These findings are interpreted as the magnetic tensions force acting on open magnetic field lines before reconnecting in the magnetotail. This can also be thought of as the IMF penetrating the magnetosphere. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. NASA, Goddard Space Flight Ctr, Lab Extraterr Phys, Greenbelt, MD 20771 USA. RP Ostgaard, N (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM nikost@ssl.berkeley.edu; mende@ssl.berkeley.edu; hfrey@ssl.berkeley.edu; immel@ssl.berkeley.edu; louis-frank@uiowa.edu; john-sigwarth@uiowa.edu; tstubbs@lepvax.gsfc.nasa.gov RI Stubbs, Timothy/I-5139-2013; OI Stubbs, Timothy/0000-0002-5524-645X; Frey, Harald/0000-0001-8955-3282 NR 29 TC 49 Z9 49 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 8 PY 2004 VL 109 IS A7 AR A07204 DI 10.1029/2003JA010370 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 837SU UT WOS:000222657200005 ER PT J AU Johnson, PV Kim, HI Beegle, LW Kanik, I AF Johnson, PV Kim, HI Beegle, LW Kanik, I TI Electrospray ionization ion mobility spectrometry of amino acids: Ion mobilities and a mass-mobility correlation SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DRIFT-GAS; MURCHISON METEORITE; HYDROCARBONS AB As part of an ongoing effort to explore the utility of high-resolution electrospray ionization ion mobility spectrometry (ESI-IMS) for the detection and identification of organic molecules on other planetary bodies, pursuant to NASA objectives, the reduced ion mobilities of 14 amino acids that have been identified in meteoritic material were determined in both N-2 and CO2 drift gases. A (12,4) hard core potential model of the ion-neutral interaction was applied to a combined data set of amino acid mobilities from the present work (abiotic) and an earlier investigation of twenty common biotic amino acids (Beegle, L. W.; Kanik, I.; Matz, L.; Hill, H. H. Anal. Chem. 2001, 73, 3028-3034). The model was used to investigate the protonated amino acid mass-mobility correlation to extract details of the ion-neutral interaction and to gain insight into the structural details of these ions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Calif State Univ Fullerton, Dept Phys, Fullerton, CA 92834 USA. RP Johnson, PV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM johnson@jpl.nasa.gov RI Beegle, Luther/A-6354-2010; Kim, Hugh/G-4476-2011; Johnson, Paul/D-4001-2009 OI Johnson, Paul/0000-0002-0186-8456 NR 24 TC 22 Z9 22 U1 0 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUL 8 PY 2004 VL 108 IS 27 BP 5785 EP 5792 DI 10.1021/jp0492117 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 835IW UT WOS:000222477200005 ER PT J AU Hitchman, MH Buker, ML Tripoli, GJ Pierce, RB Al-Saadi, JA Browell, EV Avery, MA AF Hitchman, MH Buker, ML Tripoli, GJ Pierce, RB Al-Saadi, JA Browell, EV Avery, MA TI A modeling study of an East Asian convective complex during March 2001 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone transport; stratosphere-troposphere exchange ID STRATOSPHERE-TROPOSPHERE EXCHANGE; POTENTIAL VORTICITY; CHEMICAL-TRANSPORT; TROPOPAUSE FOLDS; OZONE; SIMULATION; WAVES; CONSTITUENTS; RESOLUTION; AEROSOL AB During March-April 2001 the University of Wisconsin Nonhydrostatic Modeling System (UWNMS) was used to provide flight planning and estimation of ozone flux into the troposphere over East Asia in support of the Transport and Chemical Evolution over the Pacific (TRACE-P) mission. On 24 March a convective complex developed in eastern China and propagated eastward over the Pacific south of Japan. Aircraft and satellite observations, together with the UWNMS simulations, captured this convective event, which first entrained urban boundary layer air over Asia and then marine boundary layer air over the Pacific. The convective updraft split the subtropical westerly jet, deformed the tropopause upward, radiated gravity waves into the stratosphere, and induced a ring of stratospheric ozone to descend around its periphery into the middle troposphere. The DC-8 observations and UWNMS show a vault of moderate ozone (similar to65 ppbv) in the 8-12 km layer within the convection, with high stratospheric values (similar to100 ppbv) subsiding around the periphery into the troposphere near 6.5 km. A new two-scale method for diagnosing cross-tropopause ozone flux is compared with an annular volume estimate. During this 24 hour convective event, similar to0.8 Tg ozone entered the troposphere from the stratosphere, comparable in magnitude to ozone fluxes in midlatitude cyclones. C1 Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI 53706 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Univ Wisconsin, Dept Atmospher & Ocean Sci, 1225 W Dayton St, Madison, WI 53706 USA. EM matt@aos.wisc.edu; marcus@aos.wisc.edu; tripoli@aos.wisc.edu; r.b.pierce@larc.nasa.gov; j.a.al-saadi@larc.nasa.gov; e.v.browell@larc.nasa.gov; m.a.avery@larc.nasa.gov RI Pierce, Robert Bradley/F-5609-2010 OI Pierce, Robert Bradley/0000-0002-2767-1643 NR 36 TC 11 Z9 11 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 7 PY 2004 VL 109 IS D15 AR D15S14 DI 10.1029/2003JD004312 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 837RY UT WOS:000222654900001 ER PT J AU Renno, NO Abreu, VJ Koch, J Smith, PH Hartogensis, OK De Bruin, HAR Burose, D Delory, GT Farrell, WM Watts, CJ Garatuza, J Parker, M Carswell, A AF Renno, NO Abreu, VJ Koch, J Smith, PH Hartogensis, OK De Bruin, HAR Burose, D Delory, GT Farrell, WM Watts, CJ Garatuza, J Parker, M Carswell, A TI MATADOR 2002: A pilot field experiment on convective plumes and dust devils SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE aerosol; convection; dust devil ID MARS ORBITER CAMERA; PATHFINDER; VORTICES; AIRCRAFT; SURFACE; STORMS; LAYER AB [ 1] Recent research suggests that mineral dust plays an important role in terrestrial weather and climate, not only by altering the atmospheric radiation budget, but also by affecting cloud microphysics and optical properties. In addition, dust transport and related Aeolian processes have been substantially modifying the surface of Mars. Dusty convective plumes and dust devils are frequently observed in terrestrial deserts and are ubiquitous features of the Martian landscape. There is evidence that they are important sources of atmospheric dust on both planets. Many studies have shown that on a small scale, dust sourcing is sensitive to a large number of factors, such as soil cover, physical characteristics, composition, topography, and weather. We have been doing comparative studies of dust events on Earth and Mars in order to shed light on important physical processes of the weather and climate of both planets. Our 2002 field campaign showed that terrestrial dust devils produce heat and dust fluxes two and five orders of magnitude larger than their background values. It also showed that charge separation within terrestrial dust devils produces strong electric fields that might play a significant role in dust sourcing. Since Martian dust devils and dust storms are stronger and larger than terrestrial events, they probably produce even stronger fluxes and electric fields. C1 Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Univ Arizona, Lunar & Planetary Sci Lab, Tucson, AZ 85721 USA. Univ Wageningen & Res Ctr, Dept Environm Sci, Wageningen, Netherlands. Univ Calif Berkeley, Space Phys Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. IMADES, Hermosillo, Sonora, Mexico. ITSON, Obregon, Mexico. Rincon Res Corp, Tucson, AZ USA. Optech Corp, Toronto, ON, Canada. RP Renno, NO (reprint author), Univ Michigan, Dept Atmospher Ocean & Space Sci, 2455 Hayward St, Ann Arbor, MI 48109 USA. EM nrenno@umich.edu RI Farrell, William/I-4865-2013 NR 38 TC 77 Z9 77 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-PLANET JI J. Geophys. Res.-Planets PD JUL 7 PY 2004 VL 109 IS E7 AR E07001 DI 10.1029/JE002219 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 837SO UT WOS:000222656600001 ER PT J AU Thornburgh, RP Chattopadhyay, A Ghoshal, A AF Thornburgh, RP Chattopadhyay, A Ghoshal, A TI Transient vibration of smart structures using a coupled piezoelectric-mechanical theory SO JOURNAL OF SOUND AND VIBRATION LA English DT Article ID COMPOSITE STRUCTURES; ACTUATORS AB A smart structural model is developed to analytically determine the transient response of arbitrary structures with piezoelectric materials and attached electrical circuitry. The equations of motion are formulated using a coupled piezoelectric formulation solving for strain and electric charge. The composite host structure is modelled using a refined higher-order laminate theory and additional degrees of freedom are then added to describe any attached electrical circuitry. The developed model results in a general framework that can be useful in solving a wide variety of coupled piezoelectric-mechanical problems. A comparison is made with classical plate theory and uncoupled piezoelectric modelling techniques to illustrate the importance of proper modelling in order to accurately estimate sensor response during transient loading of adaptive structures. The model is compared with experimental results, showing the model,to be capable of capturing several effects not possible with traditional smart structures modelling techniques. (C) 2003 Elsevier Ltd. All rights reserved. C1 Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA. RP Thornburgh, RP (reprint author), NASA, Langley Res Ctr, M-S 188B, Hamptin, VA 23681 USA. EM robert.p.thornburgh@nasa.gov NR 11 TC 18 Z9 19 U1 0 U2 1 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD JUL 6 PY 2004 VL 274 IS 1-2 BP 53 EP 72 DI 10.1016/s0022-460x(30)00648-5 PG 20 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 831TT UT WOS:000222219800004 ER PT J AU Cambon, C Rubinstein, R Godeferd, FS AF Cambon, C Rubinstein, R Godeferd, FS TI Advances in wave turbulence: rapidly rotating flows SO NEW JOURNAL OF PHYSICS LA English DT Article ID HOMOGENEOUS TURBULENCE; LARGE-SCALE; ENERGY; ANISOTROPY; DYNAMICS AB At asymptotically high rotation rates, rotating turbulence can be described as a field of interacting dispersive waves by the general theory of weak wave turbulence. However, rotating turbulence has some complicating features, including the anisotropy of the wave dispersion relation and the vanishing of the wave frequency on a non-vanishing set of 'slow' modes. These features prevent straightforward application of existing theories and lead to some interesting properties, including the transfer of energy towards the slow modes. This transfer competes with, and might even replace, the transfer to small scales envisioned in standard turbulence theories. In this paper, anisotropic spectra for rotating turbulence are proposed based on weak turbulence theory; some evidence for their existence is given based on numerical calculations of the wave turbulence equations. Previous arguments based on the properties of resonant wave interactions suggest that the slow modes decouple from the others. Here, an extended wave turbulence theory with non-resonant interactions is proposed in which all modes are coupled; these interactions are possible only because of the anisotropy of the dispersion relation. Finally, the vanishing of the wave frequency on the slow modes implies that these modes cannot be described by weak turbulence theory. A more comprehensive approach to rotating turbulence is proposed to overcome this limitation. C1 Ecole Cent Lyon, LMFA, F-69130 Ecully, France. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Cambon, C (reprint author), Ecole Cent Lyon, LMFA, F-69130 Ecully, France. EM claude.cambon@ec-lyon.fr NR 34 TC 59 Z9 60 U1 3 U2 4 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 2004 VL 6 AR 73 DI 10.1088/1367-2630/6/1/073 PG 29 WC Physics, Multidisciplinary SC Physics GA 836EA UT WOS:000222537000002 ER PT J AU Numata, K Yamamoto, K Ishimoto, H Otsuka, S Kawabe, K Ando, M Tsubono, K AF Numata, K Yamamoto, K Ishimoto, H Otsuka, S Kawabe, K Ando, M Tsubono, K TI Systematic measurement of the intrinsic losses in various kinds of bulk fused silica SO PHYSICS LETTERS A LA English DT Article DE fused silica; quality factor; nodal support; thermal noise; gravitational wave detectors ID VITREOUS SILICA; MECHANICAL LOSS; BRILLOUIN-SCATTERING; LASER-INTERFEROMETER; QUALITY FACTOR; NODAL SUPPORT; ATTENUATION; DETECTORS; PENDULUM; PHONONS AB We systematically measured and compared the mechanical losses of various kinds of bulk fused silica. Their quality factors ranged widely from 7 x 10(5) to 4 x 10(7), the latter being one of the highest reported among bulk fused silica. We observed frequency-dependent losses and a decrease in the losses upon annealing. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. Univ Tokyo, Inst Solid State Phys, Kashiwa, Chiba 2778581, Japan. RP Numata, K (reprint author), NASA, Goddard Space Flight Ctr, Code 661,8800 Greenbelt Rd, Greenbelt, MD 20771 USA. EM numata@t-munu.phys.s.u-tokyo.ac.jp RI Kawabe, Keita/G-9840-2011; ANDO, MASAKI/G-4989-2014 OI ANDO, MASAKI/0000-0002-8865-9998 NR 33 TC 18 Z9 18 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JUL 5 PY 2004 VL 327 IS 4 BP 263 EP 271 DI 10.1016/j.physleta.2004.05.028 PG 9 WC Physics, Multidisciplinary SC Physics GA 834DT UT WOS:000222392500001 ER PT J AU Gibbard, SG de Pater, I Macintosh, BA Roe, HG Max, CE Young, EF McKay, CP AF Gibbard, SG de Pater, I Macintosh, BA Roe, HG Max, CE Young, EF McKay, CP TI Titan's 2 mu m surface albedo and haze optical depth in 1996-2004 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HUBBLE-SPACE-TELESCOPE; ADAPTIVE OPTICS; TROPOSPHERIC CLOUDS; TRIPLE CORRELATION; SEASONAL-CHANGE; IMAGES AB We observed Titan in 1996-2004 with high-resolution 2 mm speckle and adaptive optics imaging at the W. M. Keck Observatory. By observing in a 2 mm broadband filter we obtain images that have contributions from both Titan's surface and atmosphere. We have modeled Titan's atmosphere using a plane-parallel radiative transfer code that has been corrected to agree with 3-D Monte Carlo predictions. We find that Titan's surface albedo ranges from less than or equal to0.02 in the darkest equatorial region of the trailing hemisphere to similar or equal to0.1 in the brightest areas of the leading hemisphere. Over the past quarter of a Saturnian year haze optical depth in Titan's Southern hemisphere has decreased substantially from a value of 0.48 in 1996 down to 0.18 in 2004, while the northern haze has been increasing over the past few years. As a result of these changes, in 2004 the North/South haze asymmetry at K' band has disappeared. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Calif Santa Cruz, Ctr Adapt Opt, Santa Cruz, CA 94064 USA. SW Res Inst, Boulder, CO 80302 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gibbard, SG (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. EM sgibbard@igpp.ucllnl.org OI Max, Claire/0000-0003-0682-5436 NR 29 TC 12 Z9 12 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 3 PY 2004 VL 31 IS 17 AR L17S02 DI 10.1029/2004GL019803 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 839JK UT WOS:000222779900001 ER PT J AU Moran, TG Davila, JM AF Moran, TG Davila, JM TI Three-dimensional polarimetric imaging of coronal mass ejections SO SCIENCE LA English DT Article ID SOHO MISSION; LASCO AB We present three-dimensional reconstructions of coronal mass ejections (CMEs), which were obtained through polarization analysis of single-view images recorded with the use of the Large Angle and Spectrometric Coronagraph (LASCO) C2 coronagraph on board the Solar and Heliospheric Observatory (SOHO) spacecraft. Analysis of a loop-like CME shows a complex three-dimensional structure centered at 40degrees from the plane of the sky, moving radially at 250 kilometers/second. Reconstruction of two halo CMEs suggests that these events are expanding loop arcades. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Moran, TG (reprint author), NASA, Goddard Space Flight Ctr, Code 682-3, Greenbelt, MD 20770 USA. EM moran@morpheus.nascom.nasa.gov NR 12 TC 67 Z9 67 U1 0 U2 4 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUL 2 PY 2004 VL 305 IS 5680 BP 66 EP 70 DI 10.1126/science.1098937 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 834BG UT WOS:000222386000034 PM 15166318 ER PT J AU Mendell, WW AF Mendell, WW TI The roles of humans and robots in exploring the solar system SO ACTA ASTRONAUTICA LA English DT Article AB Historically, advocates of solar system exploration have disagreed over whether program goals could be entirely satisfied by robotic missions. Scientists tend to argue that robotic exploration is most cost-effective. However, the human space program has a great deal of support in the general public, thereby enabling the scientific element of exploration to be larger than it might be as a stand-alone activity. A comprehensive strategy of exploration needs a strong robotic component complementing and supporting human missions. Robots are needed for precursor missions, for crew support on planetary surfaces, and for probing dangerous environments. Robotic field assistants can provide mobility, access to scientific sites, data acquisition, visualization of the environment, precision operations, sample acquisition and analysis, and expertise to human explorers. As long as space exploration depends on public funds, space exploration must include an appropriate mix of human and robotic activity. Published by Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Off Human Explorat Sci SX, Houston, TX 77058 USA. RP Mendell, WW (reprint author), NASA, Lyndon B Johnson Space Ctr, Off Human Explorat Sci SX, 2101 NASA Rd 1, Houston, TX 77058 USA. EM wendell.mendell@jsc.nasa.gov NR 12 TC 1 Z9 1 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JUL PY 2004 VL 55 IS 2 BP 149 EP 155 DI 10.1016/j.actaastro.2004.01.052 PG 7 WC Engineering, Aerospace SC Engineering GA 845ZV UT WOS:000223285200007 PM 15791731 ER PT J AU Young, J AF Young, J TI "Overview by Mr John Young" (vol 54, pg 911, 2004) SO ACTA ASTRONAUTICA LA English DT Correction C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Young, J (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JUL PY 2004 VL 55 IS 2 BP 157 EP 158 DI 10.1016/j.actaastro.2004.05.001 PG 2 WC Engineering, Aerospace SC Engineering GA 845ZV UT WOS:000223285200008 ER PT J AU Cicolani, LS da Silva, JGA Duque, EPN Tischler, MB AF Cicolani, LS da Silva, JGA Duque, EPN Tischler, MB TI Unsteady aerodynamic model of a cargo container for slung-load simulation SO AERONAUTICAL JOURNAL LA English DT Article ID IDENTIFICATION; HELICOPTER AB ne problem of simulation models capable of predicting the aerodynamic instability of helicopter slung-load cargo containers and bluff bodies is addressed. Instability for these loads is known to depend on unsteady frequency-dependent aerodynamics, but simulation models that include the unsteady aerodynamics do not currently exist. This paper presents a method for generating such models using computational fluid dynamics (CFD) to generate forced-oscillation aerodynamic data and frequency domain system identification techniques to generate a frequency response from the CFD data and to identify a transfer function fit to the frequency response. The method is independent of the responsible flow phenomenon and is expected to apply to bluff-bodies generally. Preliminary results are presented for the case of the 6- by 6- by 8-ft CONEX (container express) cargo container. The present work is based on two-dimensional (2D) aerodynamic data for the CONEX side force and yaw moment generated by a forced oscillation in which frequency is varied smoothly over the range of interest. A first-order rational polynomial transfer function is found adequate to fit the aerodynamics, and this is shown to provide a good match with flight test data for the yawing motion of the CONEX. C1 NASA, Ames Res Ctr, USA NASA Rotorcraft Div, Moffett Field, CA 94035 USA. No Arizona Univ, Dept Mech Engn, Flagstaff, AZ 86011 USA. USA, Res Dev & Engn Command, Aeroflight Directorate, USA NASA Rotocraft Div, Moffett Field, CA USA. RP Cicolani, LS (reprint author), NASA, Ames Res Ctr, USA NASA Rotorcraft Div, Moffett Field, CA 94035 USA. NR 25 TC 8 Z9 9 U1 1 U2 4 PU ROYAL AERONAUTICAL SOC PI LONDON PA 4 HAMILTON PL, LONDON W1J 7BQ, ENGLAND SN 0001-9240 J9 AERONAUT J JI Aeronaut. J. PD JUL PY 2004 VL 108 IS 1085 BP 357 EP 368 PG 12 WC Engineering, Aerospace SC Engineering GA 850NI UT WOS:000223618400003 ER PT J AU Gibbs, GP Cabell, RH Juang, JN AF Gibbs, GP Cabell, RH Juang, JN TI Controller complexity for active control of turbulent boundary-layer noise from panels SO AIAA JOURNAL LA English DT Article ID STRUCTURAL ACOUSTIC CONTROL; SOUND RADIATION; PREDICTIVE CONTROL; FEEDBACK-CONTROL; MODES AB An experimental study of feedback controller complexity vs noise reduction performance for active structural acoustic control of turbulent-boundary-layer (TBL)-induced sound radiation from a panel is described. The reduction of total radiated sound power as a function of the number of actuators, sensors, and controller cost function on a mock aircraft sidewall subjected to TBL excitation are discussed. The results demonstrate total radiated sound power reductions of 15 dB at resonances and 10 dB integrated over 150-1000 Hz for a three-actuator and 15-sensor case. The controller configuration was then simplified to one actuator and four sensors (summed outputs) and was found to produce 10-15-dB reductions in sound power at resonances and 9 dB integrated over the control bandwidth. This result demonstrates the potential for achieving significant reductions in radiated sound power with a relatively simple actuator/sensor topology. C1 NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. RP Gibbs, GP (reprint author), NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. NR 23 TC 4 Z9 5 U1 1 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD JUL PY 2004 VL 42 IS 7 BP 1314 EP 1320 DI 10.2514/1.11790 PG 7 WC Engineering, Aerospace SC Engineering GA 839UW UT WOS:000222811400004 ER PT J AU Churchill, H Teng, H Hazen, RM AF Churchill, H Teng, H Hazen, RM TI Correlation of pH-dependent surface interaction forces to amino acid adsorption: Implications for the origin of life SO AMERICAN MINERALOGIST LA English DT Article ID ELECTRICAL DOUBLE-LAYER; MINERAL SURFACES; AQUEOUS-SOLUTION; MICROSCOPY; QUARTZ; CALCITE; DISSOLUTION; SPECTROSCOPY; CRYSTALS; SYSTEM AB We used an atomic force microscope (AFM) with a modified tip to measure interaction forces between a silica microsphere and surfaces of quartz, calcite, and albite over a range of pH. Minima in the magnitude of electrostatic repulsion or attraction appeared near the point of zero charge (pH(pzc)) values for quartz (approximate to 2.8), calcite (9.5), albite (2.6), and silica glass (3.5). We observed small, but significant, differences in pH(pzc) values for the (100), (101), and (011) faces of quartz. In order to correlate mineral surface charges with ionic characteristics and corresponding isoelectric points (pI) of amino acids, we immersed quartz and calcite in solutions of six amino acids. Quartz (pH(pzc) approximate to 2.8) tends to adsorb amino acids most strongly when pH(pzc) and pI differ significantly. Thus quartz adsorbs lysine (pI approximate to 9.74) more strongly than amino acids with lower pI. In contrast, calcite (pH(pzc) = 9.5) adsorbs a variety of amino acids with a range of pI. Calcite thus represents a more plausible template than quartz for prebiotic selection and organization of homochiral polypeptides. C1 Oberlin Coll, Dept Phys, Oberlin, OH 44074 USA. George Washington Univ, Dept Earth & Environm Sci, Washington, DC 20006 USA. Carnegie Inst Sci, Washington, DC 20015 USA. NASA, Astrobiol Inst, Washington, DC 20015 USA. RP Churchill, H (reprint author), Oberlin Coll, Dept Phys, Oberlin, OH 44074 USA. EM r.hazen@gl.ciw.edu RI Churchill, Hugh/F-1818-2016 OI Churchill, Hugh/0000-0002-8287-1373 NR 54 TC 65 Z9 67 U1 3 U2 32 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD JUL PY 2004 VL 89 IS 7 BP 1048 EP 1055 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 838IZ UT WOS:000222708200016 ER PT J AU Glowinski, R Shiau, L Kuo, YM Nasser, G AF Glowinski, R Shiau, L Kuo, YM Nasser, G TI The numerical simulation of friction constrained motions (I): One degree of freedom models SO APPLIED MATHEMATICS LETTERS LA English DT Article DE friction constrained motion; elasto-dynamical systems; operator-splitting; dynamical multiplier AB In a previous article [1], the authors discussed the time-discretization of those relations modeling a class of dynamical systems with friction. The main goal of this article is to address similar problems using a more sophisticated friction model giving a better description of the system behavior when the velocities are close to zero. These investigations are motivated by the need for more accurate friction models in the software simulating the motion of mechanical systems, such as the remote manipulators of the Space Shuttle or of the International Space Station. As a first step, we shall consider one degree of freedom systems. However, the methods discussed in this article can be easily generalized to higher number of degrees of freedom elasto-dynamical systems; these generalizations will be the object of another publication. The content can be summarized as follows. We first discuss several models of the constrained motions under consideration, including a rigorous formulation involving a kind of dynamical multiplier. Next, in order to treat friction, we introduce an implicit/explicit numerical scheme which is unconditionally stable, and easy to implement and generalize to more complicated systems. Indeed, the above scheme can be coupled, via operator-splitting, to schemes classically used to solve differential equations from frictionless elasto-dynamics. The above schemes are validated through numerical experiments. (C) 2004 Elsevier Ltd. All rights reserved. C1 Univ Houston, Dept Math, Houston, TX 77204 USA. Univ Houston Clear Lake, Dept Math, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Nasser Engn, Houston, TX 77058 USA. RP Glowinski, R (reprint author), Univ Houston, Dept Math, Houston, TX 77204 USA. NR 4 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 0893-9659 J9 APPL MATH LETT JI Appl. Math. Lett. PD JUL PY 2004 VL 17 IS 7 BP 801 EP 807 DI 10.1016/j.aml.2004.06.008 PG 7 WC Mathematics, Applied SC Mathematics GA 842QV UT WOS:000223020000009 ER PT J AU Jacobson, RA AF Jacobson, RA TI The orbits of the major Saturnian satellites and the gravity field of Saturn from spacecraft and earth-based observations SO ASTRONOMICAL JOURNAL LA English DT Review DE planets and satellites : general; planets and satellites : individual (Saturn); solar system : general ID CCD ASTROMETRIC OBSERVATIONS; 1ST 8 SATELLITES; OUTER PLANETS; VOYAGER OBSERVATIONS; FASTT OBSERVATIONS; TRACKING DATA; POSITIONS; SYSTEM; IAPETUS; TETHYS AB We have fitted numerically integrated orbits for the major Saturnian satellites to a large set of astrometric observations over the time interval 1966 September to 2003 December and to data obtained with the Pioneer 11, Voyager, and Cassini spacecraft. The results of the fit are new ephemerides for the satellites and a revised gravity field for the Saturnian system. We include an accuracy assessment for the ephemerides and the gravity parameters. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jacobson, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM robert.jacobson@jpl.nasa.gov NR 141 TC 33 Z9 34 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUL PY 2004 VL 128 IS 1 BP 492 EP 501 DI 10.1086/421738 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 838GZ UT WOS:000222702800039 ER PT J AU Porquet, D Reeves, JN O'Brien, P Brinkmann, W AF Porquet, D Reeves, JN O'Brien, P Brinkmann, W TI XMM-Newton EPIC observations of 21 low-redshift PG quasars SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : quasars : general X-rays : general; galaxies : nuclei; radiation mechanisms : general ID ACTIVE GALACTIC NUCLEI; SEYFERT 1 GALAXIES; X-RAY-PROPERTIES; BLACK-HOLE MASSES; OPTICALLY SELECTED QUASARS; RADIO-QUIET QUASARS; STELLAR OBJECTS; COMPLETE SAMPLE; EMISSION-LINE; SPECTRAL COMPLEXITY AB We present an X-ray spectral analysis of 21 low redshift quasars observed with XMM-Newton EPIC. All the sources are Palomar Green quasars with redshifts between 0.05 and 0.4 and have low Galactic absorption along the line-of-sight. A large majority of quasars in the sample (19/21) exhibit a significant soft excess below similar to 1-1.5 keV, whilst two objects (PG 1114+445 and IZwI) show a deficit of soft X-ray flux due to the presence of a strong warm absorber. Indeed, contrary to previous studies with ASCA and ROSAT, we find that the presence of absorption features near 0.6-1.0 keV is common in our sample. At least half of the objects appear to harbor a warm absorber, as found previously in Seyfert 1 galaxies. We find significant detections of Fe Kalpha emission lines in at least twelve objects, whilst there is evidence for some broadening of the line profile, compared to the EPIC-pn resolution, in five of these quasars. The determination of the nature of this broadening (e.g., Keplerian motion, a blend of lines, relativistic effects) is not possible with the present data and requires either higher S/N or higher resolution spectra. In seven objects the line is located between 6.7-7 keV, corresponding to highly ionized iron, whereas in the other five objects the line energy is consistent with 6.4 keV, i.e. corresponding to near neutral iron. The ionized lines tend to be found in the quasars with the steepest X-ray spectra. We also find a correlation between the continuum power law index F and the optical Hbeta width, in both the soft and hard X-ray bands, whereby the steepest X-ray spectra are found in objects with narrow Hbeta widths, which confirms previous ROSAT and ASCA results. The soft and hard band X-ray photon indices are also strongly correlated, i.e. the steepest soft X-ray spectra correspond the steepest hard X-ray spectra. We propose that a high accretion rate and a smaller black hole mass is likely to be the physical driver responsible for these trends, with the steep spectrum objects likely to have smaller black hole masses accreting near the Eddington rate. C1 Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. RP Max Planck Inst Extraterr Phys, Postfach 1312, D-85741 Garching, Germany. EM dporquet@mpe.mpg.de OI Porquet, Delphine/0000-0001-9731-0352 NR 81 TC 149 Z9 150 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 2004 VL 422 IS 1 BP 85 EP 95 DI 10.1051/0004-6361:20047108 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 844PE UT WOS:000223171300014 ER PT J AU Kaastra, JS Steenbrugge, KC Crenshaw, DM Kraemer, SB Arav, N George, IM Liedahl, DA van der Meer, RLJ Paerels, FBS Turner, TJ Yaqoob, T AF Kaastra, JS Steenbrugge, KC Crenshaw, DM Kraemer, SB Arav, N George, IM Liedahl, DA van der Meer, RLJ Paerels, FBS Turner, TJ Yaqoob, T TI Simultaneous X-ray and ultraviolet spectroscopy of the Seyfert galaxy NGC 5548 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; galaxies : Seyfert; galaxies : individual : NGC 5548; X-rays : individual : NGC 5548; X-rays : galaxies ID INTRINSIC ABSORPTION; NGC 5548; VARIABILITY; CHANDRA AB The Seyfert 1 galaxy NGC 5548 was observed for a week by Chandra using both the HETGS and LETGS spectrometers. In this paper we study the time variability of the continuum radiation. During our observation, the source showed a gradual increase in flux over four days, followed by a rapid decrease and flattening of the light curve afterwards. Superimposed upon these relatively slow variations several short duration bursts or quasi-periodic oscillations occured with a typical duration of several hours and separation between 0.6-0.9 days. The bursts show a delay of the hard X-rays with respect to the soft X-rays of a few hours. We interpret these bursts as occurring due to a rotating, fluctuating hot spot at approximately 10 gravitational radii; the time delay of the hard X-rays from the bursts agrees with the canonical picture of Inverse Compton scattering of the soft accretion disk photons on a hot medium that is relatively close to the central black hole. C1 SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands. Georgia State Univ, Dept Phys & Astron, Astron Off, Atlanta, GA 30303 USA. Catholic Univ Amer, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Colorado, CASA, Boulder, CO 80309 USA. Univ Maryland, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Lawrence Livermore Natl Lab, Dept Phys, Livermore, CA 94550 USA. Columbia Univ, Astrophys Lab, New York, NY 10027 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP Kaastra, JS (reprint author), SRON, Natl Inst Space Res, Sorbonnelaan 2, NL-3584 CA Utrecht, Netherlands. EM J.S.Kaastra@sron.nl NR 17 TC 10 Z9 10 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2004 VL 422 IS 1 BP 97 EP 102 DI 10.1051/0004-6361:20040291 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 844PE UT WOS:000223171300015 ER PT J AU Gorosabel, J Rol, E Covino, S Castro-Tirado, AJ Ceron, JMC Lazzati, D Hjorth, J Malesani, D Della Valle, M di Serego Alighieri, S Fiore, F Fruchter, AS Fynbo, JPU Ghisellini, G Goldoni, P Greiner, J Israel, GL Kaper, L Kawai, N Klose, S Kouveliotou, C Le Floc'h, E Masetti, N Mirabel, F Moller, P Ortolani, S Palazzi, E Pian, E Rhoads, J Ricker, G Saracco, P Stella, L Tagliaferri, G Tanvir, N van den Heuvel, E Vietri, M Vreeswijk, PM Wijers, RAMJ Zerbi, FM AF Gorosabel, J Rol, E Covino, S Castro-Tirado, AJ Ceron, JMC Lazzati, D Hjorth, J Malesani, D Della Valle, M di Serego Alighieri, S Fiore, F Fruchter, AS Fynbo, JPU Ghisellini, G Goldoni, P Greiner, J Israel, GL Kaper, L Kawai, N Klose, S Kouveliotou, C Le Floc'h, E Masetti, N Mirabel, F Moller, P Ortolani, S Palazzi, E Pian, E Rhoads, J Ricker, G Saracco, P Stella, L Tagliaferri, G Tanvir, N van den Heuvel, E Vietri, M Vreeswijk, PM Wijers, RAMJ Zerbi, FM TI GRB 020813: Polarization in the case of a smooth optical decay SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts; techniques : photometric; techniques : polarimetric ID GAMMA-RAY BURSTS; GRB 990510; LINEAR-POLARIZATION; LIGHT CURVES; AFTERGLOW; GRB-021004; RADIATION AB We present the results of a VLT polarimetric monitoring campaign of the GRB 020813 optical afterglow carried out in three nights, from 0.88 to 4.20 days after the gamma-ray event. The mean values of the degree of linear polarization (P) and its position angle (theta) resulting from our campaign are

= 1.18 +/- 0.10% and = 148.7degrees +/- 2.3degrees, after correcting for Galactic interstellar polarization. Our VLT data set is most naturally described by a constant degree of linear polarization and position angle, nonetheless a slow theta evolution cannot be entirely ruled out by our data. The VLT monitoring campaign did not reveal either a significant theta rotation respect to the Keck spectropolarimetric observations performed similar to0.25 days after the GRB (Barth et al. 2003). However,

is a factor of two lower than the polarization degree measured from Keck. Additionally, the VLT polarization data allowed us to construct an accurate V-band light curve. The V-band photometric data revealed a smooth light curve with a break located between the last Keck and our first VLT polarimetric measurement, 0.33 < t(break,V) < 0.88 days after the GRB. The typical magnitude fluctuations of the VLT V-band lightcurve are 0.003 mag, 0.010 mag and 0.016 mag for our three observing nights, respectively. We speculate that the stability of theta might be related to the smoothness of the light curve. C1 CSIC, Inst Astrofis Andalucia, Granada 18080, Spain. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Amsterdam, NL-1098 SJ Amsterdam, Netherlands. Osserv Astron Brera, INAF, I-23807 Merate, LC, Italy. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Copenhagen, Astron Observ, DK-2100 Copenhagen O, Denmark. ISAS, SISSA, Int Sch Adv Studies, I-34016 Trieste, Italy. Osserv Astrofis Arcetri, INAF, I-50125 Florence, Italy. Osserv Astron Roma, INAF, I-00044 Frascati, Italy. Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark. LOrme Merisiers, DAPNIA, DSM, CEA, Gif Sur Yvette, France. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. Tokyo Inst Technol, Fac Sci, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. Thuringer Landessternwarte Tautenburg, D-07778 Tautenburg, Germany. NASA, MSFC, Huntsville, AL 35812 USA. CNR, Inst Astrofis Spaziale & Fis Cosm, I-40129 Bologna, Italy. European So Observ, D-85748 Garching, Germany. Univ Padua, Dipartimento Astron, I-35122 Padua, Italy. Osserv Astron Trieste, INAF, I-34131 Trieste, Italy. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Hertfordshire, Dept Phys Sci, Hatfield AL10 9AB, Herts, England. Scuola Normale Super Pisa, I-56100 Pisa, Italy. European So Observ, Santiago 19, Chile. RP Gorosabel, J (reprint author), CSIC, Inst Astrofis Andalucia, POB 03004, Granada 18080, Spain. EM jgu@iaa.es RI di Serego Alighieri, Sperello/E-4067-2010; Hjorth, Jens/M-5787-2014; Palazzi, Eliana/N-4746-2015; OI Israel, GianLuca/0000-0001-5480-6438; di Serego Alighieri, Sperello/0000-0001-8769-2692; Hjorth, Jens/0000-0002-4571-2306; ORTOLANI, SERGIO/0000-0001-7939-5348; Ghisellini, Gabriele/0000-0002-0037-1974; Wijers, Ralph/0000-0002-3101-1808; Palazzi, Eliana/0000-0002-8691-7666; Zerbi, Filippo Maria/0000-0002-9996-973X; Castro-Tirado, A. J./0000-0003-2999-3563; Della Valle, Massimo/0000-0003-3142-5020; Covino, Stefano/0000-0001-9078-5507; Masetti, Nicola/0000-0001-9487-7740; Tagliaferri, Gianpiero/0000-0003-0121-0723; Saracco, Paolo/0000-0003-3959-2595; Pian, Elena/0000-0001-8646-4858; Fiore, Fabrizio/0000-0002-4031-4157 NR 41 TC 18 Z9 18 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2004 VL 422 IS 1 BP 113 EP 119 DI 10.1051/0004-6361:20034409 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 844PE UT WOS:000223171300017 ER PT J AU Rousselet-Perraut, K Stehle, C Lanz, T Le Bouquin, JB Boudoyen, T Kilbinger, M Kochukhov, O Jankov, S AF Rousselet-Perraut, K Stehle, C Lanz, T Le Bouquin, JB Boudoyen, T Kilbinger, M Kochukhov, O Jankov, S TI Stellar activity and magnetism studied by optical interferometry SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE techniques : interferometric; techniques : polarimetric; stars : chemically peculiar; stars : magnetic fields; stars : activity ID LINEARLY POLARIZED-LIGHT; EPSILON-URSAE-MAJORIS; POLARIMETRIC INTERFEROMETRY; AP STARS; GAMMA-CASSIOPEIAE; FIELDS; SPIN; STRATIFICATION; ATMOSPHERES; DIAGNOSIS AB By means of numerical simulations, we investigate the ability of optical interferometry, via the fringe phase observable, to address stellar activity and magnetism. To derive abundance maps and stellar rotation axes, we use color differential interferometry which couples high angular resolution to high spectral resolution. To constrain magnetic field topologies, we add to this spectro-interferometer a polarimetric mode. Two cases of well-known Chemically Peculiar (CP) stars (betaCrB and alpha(2)CVn) are simulated to derive instrumental requirements to obtain 2D-maps of abundance inhomogeneities and magnetic fields. We conclude that the near-infrared instrument AMBER of the VLTI will allow us to locate abundance inhomogeneities of CP stars larger than a fraction of milliarcsecond whereas the polarimetric mode of the French G12T/REGAIN interferometer would permit one to disentangle various magnetic field topologies on CP stars. We emphasize the crucial need for developing and validating inversion algorithms so that future instruments on optical aperture synthesis arrays can be optimally used. C1 Observ Grenoble, Astrophys Lab, F-38041 Grenoble 9, France. Observ Paris, Lab Univers & THeories, UMR 8102, F-92195 Meudon, France. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Bonn, Inst Astrophys & Extraterr Forsch, D-53121 Bonn, Germany. Uppsala Astron Observ, S-75120 Uppsala, Sweden. CNRS, UMR 6528, Dept Fresnel, Observ Cote Azur, F-06460 St Vallier De Thiey, France. RP Rousselet-Perraut, K (reprint author), Observ Grenoble, Astrophys Lab, BP 53, F-38041 Grenoble 9, France. EM karine.perraut@obs.ujf-grenoble.fr OI Kilbinger, Martin/0000-0001-9513-7138 NR 49 TC 15 Z9 15 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2004 VL 422 IS 1 BP 193 EP 203 DI 10.1051/0004-6361:20040151 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 844PE UT WOS:000223171300024 ER PT J AU Favre, P Petrucci, PO Beckmann, V Courvoisier, TJL AF Favre, P Petrucci, PO Beckmann, V Courvoisier, TJL TI BeppoSAX observations of the quasar Markarian 205 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; galaxies : quasars : individual : Mrk 205; X-rays : galaxies ID X-RAY-SPECTRA; ACTIVE GALACTIC NUCLEI; RADIO-QUIET QUASARS; ENERGY CONCENTRATOR SPECTROMETER; ACCRETION DISK MODELS; SEYFERT-GALAXIES; ASTRONOMY SATELLITE; COMPTON REFLECTION; COLD MATTER; GAMMA-RAYS AB We present the first BeppoSAX observation (0.1 to 220 keV) of the quasar Mrk 205. We have searched for the unusual Fe line profile observed in the XMM-Newton spectrum which has been widely discussed in the recent literature. We find no evidence for a broad, ionized Fe line component in our data. We detect for the first time a Compton hump in this object. When this component is included in the fit, the line strength diminishes, in agreement with a recent re-analysis of the XMM-Newton data, but with better constraints on the reflection component thanks to the PDS instrument (15-220 keV). We interpret this fact as another indication for illumination of distant, cold material rather than reprocessing in the highly ionized inner part of an accretion disk. We cannot constrain the presence of a high energy cutoff but we confirm the existence of a variable soft excess (one year time scale). C1 INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland. Observ Geneva, CH-1290 Sauverny, Switzerland. Lab Astrophys Grenoble, F-38041 Grenoble, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Joint Ctr Astrophys, Dept Phys, Baltimore, MD 21250 USA. RP Favre, P (reprint author), INTEGRAL Sci Data Ctr, 16 Ch Ecogia, CH-1290 Versoix, Switzerland. EM pascal.favre@obs.unige.ch NR 53 TC 1 Z9 1 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2004 VL 421 IS 1 BP 91 EP 101 DI 10.1051/0004-6361:20034575 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 840HD UT WOS:000222847800015 ER PT J AU Jewell, J Levin, S Anderson, CH AF Jewell, J Levin, S Anderson, CH TI Application of Monte Carlo algorithms to the Bayesian analysis of the cosmic microwave background SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; methods : data analysis; methods : statistical ID POWER SPECTRUM; SKY MAPS AB Power spectrum estimation and evaluation of associated errors in the presence of incomplete sky coverage; nonhomogeneous, correlated instrumental noise; and foreground emission are problems of central importance for the extraction of cosmological information from the cosmic microwave background (CMB). We develop a Monte Carlo approach for the maximum likelihood estimation of the power spectrum. The method is based on an identity for the Bayesian posterior as a marginalization over unknowns, and maximization of the posterior involves the computation of expectation values as a sample average from maps of the cosmic microwave background and foregrounds given some current estimate of the power spectrum or cosmological model, as well as some assumed statistical characterization of the foregrounds. Maps of the CMB and foregrounds are sampled by a linear transform of a Gaussian white-noise process, implemented numerically with conjugate gradient descent. For time series data with N-t samples and N pixels on the sphere, the method has a computational expense KO(N-2 + N-t log N-t), where K is a prefactor determined by the convergence rate of conjugate gradient descent. Preconditioners for conjugate gradient descent are given for scans close to great circle paths, and the method allows partial sky coverage for these cases by numerically marginalizing over the unobserved, or removed, region. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jewell, J (reprint author), CALTECH, Jet Prop Lab, MS 126-347,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 17 TC 79 Z9 79 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2004 VL 609 IS 1 BP 1 EP 14 DI 10.1086/383515 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832FO UT WOS:000222252900001 ER PT J AU Staguhn, JG Schinnerer, E Eckart, A Scharwachter, J AF Staguhn, JG Schinnerer, E Eckart, A Scharwachter, J TI Resolving the host galaxy of the nearby QSO I Zw 1 with subarcsecond multitransition molecular line observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : ISM; galaxies : nuclei; quasars : individual (I Zw 1); radio lines : galaxies ID ULTRALUMINOUS INFRARED GALAXIES; STAR-FORMATION; QUASARS; GAS; EMISSION; EVOLUTION; NUCLEI; VIEW AB We present the first subkiloparsec (similar to0"7 approximate to 850 pc) resolution (CO)-C-12(1-0) molecular line observations of the interstellar medium ( ISM) in the host galaxy of the QSO I Zw 1. The observations were obtained with the BIMA millimeter interferometer in its compact A configuration. The BIMA data are complemented by new observations of the (CO)-C-12(2-1) and (CO)-C-13(1-0) lines with the IRAM Plateau de Bure Interferometer (PdBI) at 0."9 and 2."1 resolution, respectively. These measurements, which are part of a multiwavelength study of the host galaxy of I Zw 1, are aimed at comparing the ISM properties of a QSO host with those of nearby galaxies, as well as to obtain constraints on galaxy formation/evolution models. Our images of the (CO)-C-12(1-0) line emission show a ringlike structure in the circumnuclear molecular gas distribution with an inner radius of about 1.2 kpc. The presence of such a molecular gas ring was predicted from earlier lower angular resolution PdBI (CO)-C-12(1-0) observations. A comparison of the BIMA data with IRAM PdBI (CO)-C-12(2-1) observations shows variations in the excitation conditions of the molecular gas in the innermost 1."5 comprising the nuclear region of I Zw 1. The observed properties of the molecular cloud complexes in the disk of the host galaxy suggest that they may be the sites of massive circumnuclear star formation and show no indications of excitation by the active galactic nucleus (AGN). This all indicates that the molecular gas in a QSO host galaxy has properties similar to the gas observed in nearby low-luminosity AGNs. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. SSAI, Lanham, MD 20706 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Cologne, Inst Phys 1, D-50923 Cologne, Germany. RP Staguhn, JG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM staguhn@stars.gsfc.nasa.gov OI Schinnerer, Eva/0000-0002-3933-7677 NR 27 TC 9 Z9 9 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2004 VL 609 IS 1 BP 85 EP 93 DI 10.1086/421039 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832FO UT WOS:000222252900009 ER PT J AU Majid, WA Lamb, RC Macomb, DJ AF Majid, WA Lamb, RC Macomb, DJ TI X-ray pulsars in the Small Magellanic Cloud SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (Small Magellanic Cloud); Magellanic Clouds; pulsars : general; stars : neutron; X-rays : stars ID WIND ACCRETION; DISCOVERY; BINARIES; SMC; STARS AB XMM-Newton archival data for the Small Magellanic Cloud have been examined for the presence of previously undetected X-ray pulsars. One such pulsar, with a period of 202 s, is detected. Its position is consistent with an early B star in the SMC, and we identify it as a high-mass X-ray binary (HMXB). In the course of this study we determined the pulse period of the possible AXP CXOU J010043.1-721134 to be 8.0 s, correcting an earlier report (Lamb et al.) of a 5.4 s period for this object. Pulse profiles and spectra for each of these objects are presented as well as for a recently discovered (Haberl & Pietsch) 263 s X-ray pulsar. Properties of an ensemble of 24 optically identified HMXB pulsars from the SMC are investigated. The locations of the pulsars and an additional 22 X-ray pulsars not yet identified as having high-mass companions are located predominately in the young (ages less than or equal to3 x 10(7) yr) star-forming regions of the SMC, as expected on the basis of binary evolution models. We find no significant difference between the distribution of spin periods for the HMXB pulsars of the SMC and that of the Milky Way. For those HMXB pulsars that have Be companions we note an inverse correlation between spin period and maximum X-ray flux density. (This anticorrelation has been previously noted for all X-ray binary pulsars by Stella, White, & Rosner) The anticorrelation for the Be binaries may be a reflection of the fact that the spin periods and orbital periods of Be HMXBs are correlated. We note a similar correlation between X-ray luminosity and spin period for the Be HMXB pulsars of the Milky Way and speculate that exploitation of the correlation could serve as a distance indicator. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. Boise State Univ, Dept Phys, Boise, ID 83725 USA. RP Majid, WA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 39 TC 36 Z9 36 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2004 VL 609 IS 1 BP 133 EP 143 DI 10.1086/420925 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832FO UT WOS:000222252900014 ER PT J AU Sakon, I Onaka, T Ishihara, D Ootsubo, T Yamamura, I Tanabe, T Roellig, TL AF Sakon, I Onaka, T Ishihara, D Ootsubo, T Yamamura, I Tanabe, T Roellig, TL TI The unidentified infrared bands in the diffuse interstellar medium across the galaxy based on the Infrared Telescope in Space mid-infrared spectrometer observation SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; infrared : ISM; ISM : lines and bands ID POLYCYCLIC AROMATIC-HYDROCARBONS; CARBONACEOUS COMPOSITE QCC; SMALL-MAGELLANIC-CLOUD; EMISSION BANDS; GALACTIC EMISSION; CIRCUMSTELLAR ENVELOPES; HII-REGIONS; ORION BAR; UIR BANDS; MILKY-WAY AB We present the results of observations of the unidentified infrared (UIR) bands in the diffuse Galactic emission across the Galaxy by the Mid-Infrared Spectrometer (MIRS) on board the Infrared Telescope in Space (IRTS). While previous studies on the UIR bands in the Milky Way were limited to the inner Galactic plane, we extend the observing area to the outer Galactic plane. In this paper we analyze the data of four areas of 8degrees; 8degrees around the Galactic plane (\b\ less than or equal to 4degrees; -12degrees less than or equal to l less than or equal to -4degrees, 44degrees less than or equal to l less than or equal to 52degrees, -136degrees less than or equal to l less than or equal to - 128degrees, and 168degrees less than or equal to l less than or equal to 176degrees) and investigate the UIR band intensity relative to the far-infrared ( FIR) intensity, as well as the variation in the band profile. Together with the good correlation between the UIR band and the FIR intensities in the four regions, we have found a systematic variation in the UIR-to-FIR ratio such that the ratio becomes larger in the outer Galactic plane than in the inner Galactic plane. In addition, the 8.6 and 11.3 mum UIR bands were found to be stronger relative to the 6.2 and 7.7 mum bands in the outer Galactic plane, which may be related to differences in the structure or physical conditions of the band carriers. We have also found small shifts ( similar to 0.1 mum) in the peak wavelength of each UIR band to shorter wavelengths from the inner Galactic plane to the outer Galactic plane. Possible interpretations of these variations are discussed. C1 Univ Tokyo, Sch Sci, Dept Astron, Bunkyo Ku, Tokyo 1130033, Japan. Natl Astron Observ, Tokyo 1818588, Japan. Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Univ Tokyo, Sch Sci, Inst Astron, Tokyo 1810015, Japan. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Sakon, I (reprint author), Univ Tokyo, Sch Sci, Dept Astron, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan. EM isakon@astron.s.u-tokyo.ac.jp; onaka@astron.s.u-tokyo.ac.jp; ishihara@astron.s.u-tokyo.ac.jp NR 72 TC 39 Z9 39 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2004 VL 609 IS 1 BP 203 EP 219 DI 10.1086/420919 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832FO UT WOS:000222252900020 ER PT J AU Ueda, Y Murakami, H Yamaoka, K Dotani, T Ebisawa, K AF Ueda, Y Murakami, H Yamaoka, K Dotani, T Ebisawa, K TI Chandra high-resolution spectroscopy of the absorption-line features in the low-mass X-ray binary GX 13+1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : individual (GX 13+1); X-rays : binaries; X-rays : stars ID TRANSMISSION GRATING SPECTROMETER; SOURCE GRO J1655-40; XMM-NEWTON; ENERGY-SPECTRA; DISCOVERY; IRON; ASCA; DISK; X-1 AB We present the results of high-resolution spectroscopy of absorption-line features of highly ionized ions in the X-ray spectra of GX 13+1 with the Chandra HETGS. We have resolved Kalpha absorption lines of hydrogen-like Fe, Mn, Cr, Ca, Ar, S, Si, and Mg ions and helium-like Fe ions. Applying the Voigt profile to these spectral features, we find that the plasma responsible for the absorption lines has a significant blueshift of 460 +/- 70 km s(-1), indicating an outflow velocity of approximate to 400 km s(-1) corrected for the proper motion, with a line-of-sight velocity dispersion of 490(-140)(+110) km s(-1). The plasma is photoionized with an ionization parameter of log xi similar or equal to 4.1-4.7. The inferred mass outflow rate is 0.7 x 10(18) g s(-1) or higher, comparable to the mass accretion rate ( 10(18) g s(-1)) estimated from the continuum spectrum. This indicates that the mass outflow plays a significant role to determine the whole dynamics of the accretion disk. We consider a simplified radiation-driven disk wind model for the origin of the outflow. Our observations are explained by the wind originating from radii of similar to 10(10) - 10(11) cm with a density greater than or similar to10(13) cm(-3). C1 Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Aoyama Gakuin Univ, Dept Phys, Kanagawa 2298558, Japan. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland. RP Ueda, Y (reprint author), Inst Space & Astronaut Sci, 3-1-1 Yoshinodai, Kanagawa 2298510, Japan. NR 26 TC 61 Z9 61 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2004 VL 609 IS 1 BP 325 EP 334 DI 10.1086/420973 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832FO UT WOS:000222252900032 ER PT J AU Burrows, A Sudarsky, D Hubeny, I AF Burrows, A Sudarsky, D Hubeny, I TI Spectra and diagnostics for the direct detection of wide-separation extrasolar giant planets SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; molecular processes; planetary systems; planets and satellites : general; radiative transfer; stars : low-mass, brown dwarfs ID BROWN DWARFS; THEORETICAL SPECTRA; KECK INTERFEROMETER; CORALIE SURVEY; HD 209458B; ATMOSPHERES; SPACE; MISSION; SOLAR; COMPANION AB We calculate as a function of orbital distance, mass, and age the theoretical spectra and orbit-averaged planet/star flux ratios for representative wide-separation extrasolar giant planets (EGPs) in the optical, near-infrared, and mid-infrared. Stellar irradiation of the planet's atmosphere and the effects of water and ammonia clouds are incorporated and handled in a consistent fashion. We include predictions for 12 specific known EGPs. In the process, we derive physical diagnostics that can inform the direct EGP detection and remote sensing programs now being planned or proposed. Furthermore, we calculate the effects of irradiation on the spectra of a representative companion brown dwarf as a function of orbital distance. C1 Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Kavli Inst Theoret Phys, Santa Barbara, CA USA. RP Burrows, A (reprint author), Univ Arizona, Dept Astron, 933 N Cherry Ave, Tucson, AZ 85721 USA. NR 62 TC 76 Z9 77 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2004 VL 609 IS 1 BP 407 EP 416 DI 10.1086/420974 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832FO UT WOS:000222252900039 ER PT J AU Ibrahim, AI Markwardt, CB Swank, JH Ransom, S Roberts, M Kaspi, V Woods, PM Safi-Harb, S Balman, S Parke, WC Kouveliotou, C Hurley, K Cline, T AF Ibrahim, AI Markwardt, CB Swank, JH Ransom, S Roberts, M Kaspi, V Woods, PM Safi-Harb, S Balman, S Parke, WC Kouveliotou, C Hurley, K Cline, T TI Discovery of a transient magnetar: XTE J1810-197 SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : general; pulsars : individual (XTE J1810-197); stars : magnetic fields; stars : neutron; X-rays : stars ID X-RAY PULSAR; APRIL BURST ACTIVATION; SOFT GAMMA-REPEATERS; NEUTRON-STARS; CYCLOTRON-RESONANCE; SGR 1900+14; FIELD; SGR1806-20 AB We report the discovery of a new X-ray pulsar, XTE J1810 - 197, that was serendipitously discovered on 2003 July 15 by the Rossi X-Ray Timing Explorer (RXTE) while observing the soft gamma repeater SGR 1806 - 20. The pulsar has a 5.54 s spin period, a soft X-ray spectrum ( with a photon index of approximate to 4), and is detectable in earlier RXTE observations back to 2003 January but not before. These show that a transient outburst began between 2002 November 17 and 2003 January 23 and that the source's persistent X-ray flux has been declining since then. The pulsar exhibits a high spin-down rate (P) over dot approximate to 10(-11) s s(-1) with no evidence of Doppler shifts due to a binary companion. The rapid spin-down rate and slow spin period imply a supercritical characteristic magnetic field B similar or equal to 3 x 10(14) G and a young age tau less than or equal to 7600 yr. Follow-up Chandra observations provided an accurate position of the source. Within its error radius, the 1.5 m Russian-Turkish Optical Telescope found a limiting magnitude R-C = 21.5. All such properties are strikingly similar to those of anomalous X-ray pulsars and soft gamma repeaters, providing strong evidence that the source is a new magnetar. However, archival ASCA and ROSAT observations found the source nearly 2 orders of magnitude fainter. This transient behavior and the observed long-term flux variability of the source in absence of an observed SGR-like burst activity make it the first confirmed transient magnetar and suggest that other neutron stars that share the properties of XTE J1810 - 197 during its inactive phase may be unidentified transient magnetars awaiting detection via a similar activity. This implies a larger population of magnetars than previously surmised and a possible evolutionary connection between magnetars and other neutron star families. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. George Washington Univ, Dept Phys, Washington, DC 20052 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. MIT, Ctr Space Res, Cambridge, MA 02139 USA. NSSTC, Univ Space Res Assoc, Huntsville, AL 35805 USA. Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada. Middle E Tech Univ, Dept Phys, TR-06531 Ankara, Turkey. NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Ibrahim, AI (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Mail Code 662, Greenbelt, MD 20771 USA. EM alaa@milkyway.gsfc.nasa.gov RI Ibrahim, Alaa/A-6250-2008; Swank, Jean/F-2693-2012; OI Ibrahim, Alaa/0000-0002-8791-7270; Roberts, Mallory/0000-0002-9396-9720; Ransom, Scott/0000-0001-5799-9714 NR 36 TC 133 Z9 135 U1 0 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2004 VL 609 IS 1 BP L21 EP L24 DI 10.1086/422636 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832FY UT WOS:000222253900006 ER PT J AU Klose, S Henden, AA Geppert, U Greiner, J Guetter, HH Hartmann, DH Kouveliotou, C Luginbuhl, CB Stecklum, B Vrba, FJ AF Klose, S Henden, AA Geppert, U Greiner, J Guetter, HH Hartmann, DH Kouveliotou, C Luginbuhl, CB Stecklum, B Vrba, FJ TI A near-infrared survey of the N49 region around the soft gamma repeater SGR 0526-66 SO ASTROPHYSICAL JOURNAL LA English DT Article DE open clusters and associations : individual (SL 463); pulsars : individual (SGR 0526-66); supernova remnants ID LARGE-MAGELLANIC-CLOUD; X-RAY PULSARS; MAGNETIZED NEUTRON-STARS; SUPERNOVA-REMNANTS; SGR 1900+14; MOLECULAR CLOUDS; CLUSTERS; ASSOCIATIONS; COUNTERPART; SGR1900+14 AB We report the results of a deep near-infrared survey with the Very Large Telescope/Infrared Spectrometer and Array Camera of the environment of the supernova remnant N49 in the Large Magellanic Cloud, which contains the soft gamma repeater SGR 0526 - 66. Two of the four confirmed SGRs are potentially associated with compact stellar clusters. We thus searched for a similar association of SGR 0526 - 66 and imaged a young stellar cluster at a projected distance of similar to 30 pc from the SGR. This constitutes the third cluster - SGR link and lends support to scenarios in which SGR progenitors originate in young dusty clusters. If confirmed, the cluster-SGR association constrains the age and thus the initial mass of SGR progenitors. C1 Thuringer Landessternwarte Tautenburg, D-07778 Tautenburg, Germany. USN Observ, Univ Space Res Assoc, Flagstaff, AZ 86001 USA. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. RP Klose, S (reprint author), Thuringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg, Germany. EM klose@tls-tautenburg.de NR 42 TC 26 Z9 26 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2004 VL 609 IS 1 BP L13 EP L16 DI 10.1086/422657 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832FY UT WOS:000222253900004 ER PT J AU Vacca, WD Cushing, MC Simon, T AF Vacca, WD Cushing, MC Simon, T TI Near-infrared spectroscopy of McNeil's Nebula Object SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : formation; stars : pre-main-sequence; stars : variables : other ID YOUNG STELLAR OBJECTS; B MOLECULAR CLOUD; T-TAURI STARS; DISK ACCRETION; FILTER SET; P-CYGNI; EX-LUPI; EMISSION; ORION; DUST AB We present 0.8 - 5.2 mum spectroscopy of the compact source at the base of a variable nebula ( McNeil's Nebula Object) in the Lynds 1630 dark cloud that went into outburst in late 2003. The spectrum of this object reveals an extremely red continuum, CO bands at 2.3 - 2.5 mum in emission, a deep 3.1 mum ice absorption feature, and a solid-state CO absorption feature at 4.7 mum. In addition, emission lines of H, Ca II, Mg I, and Na I are present. The Paschen lines exhibit P Cygni profiles, as do two lines of He I, although the emission features are very weak in the latter. The Brackett lines, however, are seen to be purely in emission. The P Cygni profiles clearly indicate that mass outflow is occurring in a wind with a velocity of similar to400 km s(-1). The H line ratios do not yield consistent estimates of the reddening, nor do they agree with the extinction estimated from the ice feature (A(V) similar to 11). We propose that these lines are optically thick and are produced in a dense, ionized wind. The near-infrared spectrum does not appear similar to any known FUor or EXor object. However, all evidence suggests that McNeil's Nebula Object is a heavily embedded low-mass Class I protostar, surrounded by a disk, whose brightening is due to a recent accretion event. C1 NASA, Ames Res Ctr, Univ Space Res Assoc, Stratospher Observ Infrared Astron, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Vacca, WD (reprint author), NASA, Ames Res Ctr, Univ Space Res Assoc, Stratospher Observ Infrared Astron, MS 144-2, Moffett Field, CA 94035 USA. EM wvacca@mail.arc.nasa.gov; mcushing@mail.arc.nasa.gov; simon@ifa.hawaii.edu NR 35 TC 20 Z9 20 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2004 VL 609 IS 1 BP L29 EP L32 DI 10.1086/422638 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832FY UT WOS:000222253900008 ER PT J AU Dovciak, M Karas, V Yaqoob, T AF Dovciak, M Karas, V Yaqoob, T TI An extended scheme for fitting X-ray data with accretion disk spectra in the strong gravity regime SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE black hole physics; galaxies : active; galaxies : individual (MCG-6-30-15); line : profiles; methods : data analysis; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; KERR BLACK-HOLE; K-ALPHA-EMISSION; RELATIVISTIC IRON LINE; DUSTY WARM ABSORBER; STABLE ORBIT; XMM-NEWTON; MCG-6-30-15; PROFILES; VARIABILITY AB Accreting black holes are believed to emit X-rays, which then mediate information about strong gravity in the vicinity of the emission region. We report on a set of new routines for the XSPEC package for analyzing X-ray spectra of black-hole accretion disks. The new computational tool significantly extends the capabilities of the currently available fitting procedures that include the effects of strong gravity and allows one to systematically explore the constraints on more model parameters than previously possible ( e. g., black-hole angular momentum). Moreover, axial symmetry of the disk intrinsic emissivity is not assumed, although it can be imposed to speed up the computations. The new routines can be used also as a stand-alone and flexible code with the capability of handling time-resolved spectra in the regime of strong gravity. We have used the new code to analyze the mean X-ray spectrum from the long XMM-Newton 2001 campaign of the Seyfert 1 galaxy MCG - 6-30-15. Consistent with previous findings, we obtained a good fit to the broad Fe K line profile for a radial line intrinsic emissivity law in the disk that is not a simple power law, and for near maximal value of black hole angular momentum. However, equally good fits can be obtained also for small values of the black hole angular momentum. The code has been developed with the aim of allowing precise modeling of relativistic effects. Although we find that current data cannot constrain the parameters of black-hole/accretion disk system well, the code allows, for a given source or situation, detailed investigations of what features of the data future studies should be focused on in order to achieve the goal of uniquely isolating the parameters of such systems. C1 Acad Sci, Inst Astron, CZ-14131 Prague, Czech Republic. Charles Univ, Fac Math & Phys, CZ-18000 Prague, Czech Republic. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Dovciak, M (reprint author), Acad Sci, Inst Astron, Bocni II, CZ-14131 Prague, Czech Republic. RI Karas, Vladimir/C-1559-2013; Dovciak, Michal/F-4258-2014 OI Karas, Vladimir/0000-0002-5760-0459; Dovciak, Michal/0000-0003-0079-1239 NR 75 TC 143 Z9 143 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUL PY 2004 VL 153 IS 1 BP 205 EP 221 DI 10.1086/421115 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832GD UT WOS:000222254400008 ER PT J AU Osten, RA Brown, A Ayres, TR Drake, SA Franciosini, E Pallavicini, R Tagliaferri, G Stewart, RT Skinner, SL Linsky, JL AF Osten, RA Brown, A Ayres, TR Drake, SA Franciosini, E Pallavicini, R Tagliaferri, G Stewart, RT Skinner, SL Linsky, JL TI A multiwavelength perspective of flares on HR 1099: 4 years of coordinated campaigns SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE radio continuum : stars; stars : activity; stars : coronae; stars : late-type; X-rays : stars ID RS-CANUM-VENATICORUM; EXTREME-ULTRAVIOLET-EXPLORER; HIGH-RESOLUTION SPECTROGRAPH; X-RAY FLARE; DIFFERENTIAL EMISSION MEASURE; SIGMA(2) CORONAE BOREALIS; HR 1099; RADIO-EMISSION; ACTIVE STARS; V711 TAURI AB We report on 4 years of multiple wavelength observations of the RS CVn system V711 Tau (HR 1099) from 1993, 1994, 1996, and 1998. This combination of radio, ultraviolet (UV), extreme ultraviolet (EUV), and X-ray observations allows us to view, in the most comprehensive manner currently possible, the coronal and upper atmospheric variability of this active binary system. We report on the changing activity state of the system as recorded in the EUV and radio across the 4 years of observations, and study the high-energy variability using an assemblage of X-ray telescopes. We find the following: 1. There is evidence for coherent emission at low radio frequencies (less than or equal to3 GHz), which appears to be both highly time variable and persistent for several hours. Such phenomena are relatively common, occurring approximate to 30% of the time HR 1099 was observed at L band. The measured polarizations of these bursts are left circularly polarized, in contrast with behavior at higher frequencies, which has the opposite helicity. The polarizations are consistent with a variable source that is 100% left circularly polarized, along with a steady level of flux and polarization, which is 0 or slightly right circularly polarized. There appears to be a low degree of correlation between bursts at 20 cm and higher frequency gyrosynchrotron flares, and also between 20 cm bursts and large EUV/soft X-ray (SXR) outbursts. 2. Higher frequency ( 5 - 8 GHz) flares show an inverse relationship between flux and polarization levels as the flare evolves; this behavior is consistent with flare emission, which is initially unpolarized. Large variations in spectral index are observed, suggesting changes in optical depths of the flaring plasma as the burst progresses. Quiescent polarization spectra show an increase of polarization with frequency, a pattern typically seen in active binary systems but still not understood. 3. EUV observations reveal several large flares, in addition to numerous smaller enhancements. The total range of variability as gleaned from light curve variations is only a factor of 7, however. Observations in different years provide evidence of a change in the quiescent, not obviously flaring, luminosity, by a factor of up to 2. From an analysis of time-resolved spectral variations, we are able to infer evidence for the creation of high-temperature plasma during flare intervals compared with quiescent intervals. Interpretation of EUV spectral variations is hindered by the lack of ability to diagnose continuum levels and activity-related abundance changes, which are known from higher energy observations. Electron densities determined by line ratios of density-sensitive emission lines are high ( 10(12) - 10(13) cm(-3)), and there is no evidence for large density enhancements during flare intervals, compared with quiescent intervals. 4. X-ray observations reveal several flares and provide evidence of energy-dependent flare evolution: harder X-ray energies show faster temporal evolution than at softer energies. Time-resolved X-ray spectral analysis shows the presence of hot plasma, T-e similar to 30 MK, during flares compared with quiescent intervals, as well as evidence for changing abundances during flares. The abundance of iron ( which is subsolar) shows an enhancement of a factor of 3 at the peak of a moderate flare seen by ASCA relative to the preflare level; abundances decrease during the flare decay. No hard (> 15 keV) emission is detected by either RXTE or BeppoSAX. 5. The luminosity ratios L-EUV/L-R in quiescence determined from several time intervals during the four campaigns are consistent with previously determined ratios from a sample of active stars and solar flares. The range of L-EUV/L-R from three EUV/radio (3.6 cm) flares is the same as the values obtained during quiescence, which points to a common mechanism for producing both flaring and not flaring emission. 6. Seventeen flares were observed in the EUV and/or SXR during the four campaigns; of the eight flares that had radio coverage, three show 3.6 cm radio flares, which are generally consistent with the Neupert effect. Five EUV/SXR flares had partial UV coverage; all show UV responses, particularly in the C IV transition. The UV flare enhancements can occur at the same time as the 3.6 cm radio flares, in two cases where radio, UV, and EUV/SXR flare coverage overlapped. 7. For SXR flares, we find that the contrast between flare emission and quiescent emission increases as expected toward higher energies, making flare detections easier at harder X-ray energies. This is due to the creation of high-temperature plasma during flares, which shows up predominantly in high-energy continuum emission. We find a discrepancy between the implied flaring rate based on EUV observations, and higher energy observations; the lower energies tend to miss many of the flares, because of the lack of sufficient contrast with quiescent emission. C1 Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, HEASARC, Greenbelt, MD 20771 USA. Osserv Astron Palermo, INAF, Palermo, Italy. Osserv Astron Brera, INAF, Merate, Italy. Australia Telescope Natl Facil, Epping, NSW 2121, Australia. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. RP Osten, RA (reprint author), Natl Radio Astron Observ, 520 Edgemont Rd, Charlottesville, VA 22903 USA. OI Tagliaferri, Gianpiero/0000-0003-0121-0723 NR 118 TC 31 Z9 31 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUL PY 2004 VL 153 IS 1 BP 317 EP 362 DI 10.1086/420770 PG 46 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832GD UT WOS:000222254400012 ER PT J AU Huntsberger, TL Trebi-Ollennu, A Aghazarian, H Schenker, PS Pirjanian, P Das Nayar, H AF Huntsberger, TL Trebi-Ollennu, A Aghazarian, H Schenker, PS Pirjanian, P Das Nayar, H TI Distributed control of multi-robot systems engaged in tightly coupled tasks SO AUTONOMOUS ROBOTS LA English DT Article DE tight coordination; distributed control architecture; multiple mobile robots ID EXPLORATION AB NASA mission concepts for the upcoming decades of this century include exploration of sites such as steep cliff faces on Mars, as well as infrastructure deployment for a sustained robotic/manned presence on planetary and/or the lunar surface. Single robotic platforms, such as the Sojourner rover successfully flown in 1997 and the Mars Exploration Rovers ( MER) which landed on Mars in January of 2004, have neither the autonomy, mobility, nor manipulation capabilities for such ambitious undertakings. One possible approach to these future missions is the fielding of cooperative multi-robot systems that have the required onboard control algorithms to more or less autonomously perform tightly coordinated tasks. These control algorithms must operate under the constrained mass, volume, processing, and communication conditions that are present on NASA planetary surface rover systems. In this paper, we describe the design and implementation of distributed control algorithms that build on our earlier development of an enabling architecture called CAMPOUT (Control Architecture for Multi-robot Planetary Outposts). We also report on some ongoing physical experiments in tightly coupled distributed control at the Jet Propulsion Lab in Pasadena, CA where in the first study two rovers acquire and carry an extended payload over uneven, natural terrain, and in the second three rovers form a team for cliff access. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Evolut Robot Inc, Pasadena, CA USA. OphirTech, Altadena, CA 91003 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Terry.Huntsberger@jpl.nasa.gov; Paolo@evolution.com; hari@ophirtech.com NR 33 TC 25 Z9 25 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0929-5593 EI 1573-7527 J9 AUTON ROBOT JI Auton. Robot. PD JUL PY 2004 VL 17 IS 1 BP 79 EP 92 DI 10.1023/B:AURO.0000032939.08597.62 PG 14 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA 832BQ UT WOS:000222242600006 ER PT J AU Arkoosh, MR Johnson, L Rossignol, PA Collier, TK AF Arkoosh, MR Johnson, L Rossignol, PA Collier, TK TI Predicting the impact of perturbations on salmon (Oncorhynchus spp.) communities: implications for monitoring SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID JUVENILE CHINOOK SALMON; ECOLOGICAL RISK ASSESSMENT; VALDEZ OIL-SPILL; POLYCHLORINATED-BIPHENYLS; MODEL-ECOSYSTEMS; FOOD-WEB; CHLORINATED HYDROCARBONS; QUALITATIVE STABILITY; ENVIRONMENTAL-STRESS; CHIRONOMUS-RIPARIUS AB Twenty-six salmon (Oncorhynchus spp.) stocks from the Pacific Northwest are listed as either threatened or endangered. A number of anthropogenic factors, likely including degradation of habitat by chemical contaminant exposure, have contributed to their decline. Techniques that can assess injury or judge the efficacy of regulatory actions on the recovery of this species are needed. We strive to understand why a population is changing by examining changes in their intrinsic birth rates, death rates, and (or) growth rates. However, salmon populations are influenced by other species in the community. To address this issue, we developed a parsimonious three-trophic-level community model consisting of prey, salmon, and parasites and examined the model's response to one anthropogenic factor (contaminant exposure) using qualitative analysis. This community model may not only provide valuable insight into salmon survival but also may broaden the approaches available to elucidate direct and indirect effects. We demonstrate analytically that some community members, possibly salmon themselves, might be ambiguous or unreliable variables to monitor. We also demonstrate that other species in the community, such as parasites, may be more sensitive than salmon in monitoring the influence of anthropogenic factors such as contaminants. C1 Natl Marine Fisheries Serv, Environm Conservat Div, NW Fisheries Sci Ctr, NOAA, Newport, OR 97365 USA. Natl Marine Fisheries Serv, Environm Conservat Div, NW Fisheries Sci Ctr, NOAA, Seattle, WA 98112 USA. Oregon State Univ, Dept Fisheries & Wildlife, Corvallis, OR 97331 USA. RP Arkoosh, MR (reprint author), Natl Marine Fisheries Serv, Environm Conservat Div, NW Fisheries Sci Ctr, NOAA, 2030 S Marine Sci Dr, Newport, OR 97365 USA. EM mary.arkoosh@noaa.gov NR 72 TC 2 Z9 3 U1 3 U2 8 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD JUL PY 2004 VL 61 IS 7 BP 1166 EP 1175 DI 10.1139/F04-068 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 861XD UT WOS:000224451000012 ER PT J AU Matsumoto, GI Nienow, JA Friedmann, EI Sekiya, E Ocampo-Friedmann, R AF Matsumoto, GI Nienow, JA Friedmann, EI Sekiya, E Ocampo-Friedmann, R TI Biogeochemical features of lipids in endolithic microbial communities in the Ross Desert (McMurdo Dry Valleys), Antarctica SO CELLULAR AND MOLECULAR BIOLOGY LA English DT Article DE biogeochemistry; endolithic microbial communities; lichen; algae; bacteria; hydrocarbons; fatty acids; Gondwanaland sediment ID FATTY-ACIDS; COLD DESERT; GEOCHEMICAL FEATURES; ORGANIC GEOCHEMISTRY; ALKANOIC ACIDS; LAKE-SEDIMENTS; ENVIRONMENT; INDICATORS; JAPAN; SOIL AB Endolithic microbial communities inhabiting porous rocks in the cold, dry mountainous regions of Antarctica have been studied extensively as examples of life's adaptations to extreme environments. Here, we examine hydrocarbons and fatty acids occurring in these communities in order to clarify their biogeochemical features with respect to source organisms, microbial activity fossilization processes and the influence of Gondwanaland sediments. Unusually, long-chain (>C-19) n-alkanes and anteiso-alkanes were often the major hydrocarbons in the samples. A suite of n-alkanoic acids (n-C-9 - n-C-32) and long-chain anteiso-alkanoic acids (a-C-20 - a-C-30) were found, along with short-chain iso- and anteiso-alkanoic acids, and n-alkenoic acids. The relationship between long-chain n-alkanoic acids (n-C-20 - n-C-32) and long-chain anteiso-alkanoic acids suggests that these compounds probably originated from the same group of microorganisms, Such as bacteria or endolithic lichens, under moderate pH conditions (pH 3-5). Relatively hiah trans/cis-C-16:1 alkenoic acid ratios suggest the presence of unfavorable environmental conditions in the endolithic microbial habitat. Normal-alkenoic/alkanoic acid ratios may be a useful marker for the fossilization of endolithic microbial communities. Thermally, matured triterpanes and steranes from fossilized associations on Mount Fleming strongly suggest the presence of Gondwanaland sediments formed during Devonian and Jurassic (400-180 million years ago). C1 Otsuma Womens Univ, Sch Social Informat Studies, Tokyo 2068540, Japan. Valdosta State Univ, Dept Biol, Valdosta, GA 31698 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Matsumoto, GI (reprint author), Otsuma Womens Univ, Sch Social Informat Studies, Tokyo 2068540, Japan. EM genki@otsuma.ac.jp NR 55 TC 5 Z9 6 U1 1 U2 5 PU CELLULAR & MOLECULAR BIOLOGY PI NOISY-LE-GRAND PA PROF R WEGMANN RESIDENCE HAUSSMANN 1 AVENUE DU PAVE NEUF, 93160 NOISY-LE-GRAND, FRANCE SN 0145-5680 J9 CELL MOL BIOL JI Cell. Mol. Biol. PD JUL PY 2004 VL 50 IS 5 BP 591 EP 604 PG 14 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 870EP UT WOS:000225037100011 PM 15559976 ER PT J AU Stone, PH Yao, MS AF Stone, PH Yao, MS TI The ice-covered Earth instability in a model of intermediate complexity SO CLIMATE DYNAMICS LA English DT Article ID NEOPROTEROZOIC SNOWBALL EARTH; STATISTICAL-DYNAMIC-MODEL; EDDY HEAT-FLUX; GENERAL-CIRCULATION; CAP INSTABILITY; ALBEDO FEEDBACK; CLIMATE MODELS; BETA-PLANE; PARAMETERIZATION; SCALE AB The ice-covered Earth instability found in energy balance models is studied with a zonal mean statistical dynamical atmospheric model coupled to a global mixed layer ocean model. The response of the model to changes in solar constant is examined in two parallel studies, one with and one without a fixed meridional heat transport (a Q-flux) being included in the ocean model. The Q-flux is derived so as to make the climate with the current value of the solar constant resemble the earth's current climate. In both cases the climate displays a hysteresis loop as the solar constant decreases and then increases, with two equilibrium states being possible for a range of values of the solar constant. In the case without a Q-flux, as in energy balance models, one state corresponds to an ice-covered Earth, and the other is partially covered. In the case with a Q-flux, because the poleward Q-flux is stronger in the Southern Hemisphere, one state corresponds to an ice-covered Northern Hemisphere, but a Southern Hemisphere that is only partially ice-covered; the other state has much reduced ice-cover in both hemispheres. In the case when the Q-flux is present, the sensitivity of the state with smaller ice-cover is about half as much, and the hysteresis loop extends over a smaller range of values of the solar constant. Also in this case there is a strong ice-covered Earth instability that sets in when the solar constant is about 13-14% below the current value. However in the case without a Q-flux the ice-covered Earth instability virtually disappears. The different behavior is attributed to the much lower efficiency of the meridional heat transport in the case with no Q-flux. The behavior in this case may be more realistic for cold climates. The results in both cases confirm the simple analytical relation between global mean surface temperature and global ice area found in energy balance models. C1 MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. NASA, Goddard Inst Space Studies, SGT, New York, NY 10025 USA. RP Stone, PH (reprint author), MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. EM phstone@mit.edu NR 28 TC 7 Z9 7 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD JUL PY 2004 VL 22 IS 8 BP 815 EP 822 DI 10.1007/s00382-004-0408-y PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 836RZ UT WOS:000222574800003 ER PT J AU Linteris, GT Katta, VR Takahashi, F AF Linteris, GT Katta, VR Takahashi, F TI Experimental and numerical evaluation of metallic compounds for suppressing cup-burner flames SO COMBUSTION AND FLAME LA English DT Article DE nanoparticles; fire suppression; flame inhibition; diffusion flames; organometallics; flame structure; cup burner; Halon replacements ID JET DIFFUSION FLAMES; PREMIXED METHANE FLAMES; IRON PENTACARBONYL; INHIBITION EFFECTIVENESS; TEMPERATURE-DEPENDENCE; REACTION KERNEL; AIR FLAMES; NITROGEN; EXTINCTION; COMBUSTION AB The first tests of supereffective flame inhibitors blended with CO2 have been performed in methane-air laminar co-flow diffusion flames stabilized on a cup burner. The CO2 volume fraction required to extinguish the flames was determined for a range of added catalytic inhibitor volume fractions. When added at low volume fraction, the agents TMT, Fe(CO)(5), and MMT were effective at reducing the volume of CO2 required to extinguish the flames, with performance relative to CF3Br of 2, 4, and 8, respectively. This performance advantage of the metallic compounds is less than that determined in premixed or counterflow diffusion flames. Further, as the volume fraction of each metallic catalytic inhibitor was increased, the effectiveness diminished rapidly. The greatly reduced marginal effectiveness is believed to be caused by loss of active gas-phase species to condensed-phase particles. Laser-scattering measurements in flames with Fe(CO)(5)/CO2 blends detected particles both inside and outside (but not coincident with) the visible flame location for measurement points above the stabilization region. For Fe(CO)(5) addition to the air stream at 450 muL/L, the peak scattering cross section for vertically polarized light was 1660 times the value for room-temperature air. The first detailed numerical modeling studies were also performed for methane-air cup-burner flames with CO2 and Fe(CO)(5) added to the oxidizer stream and are used to interpret the experimental results. The role of particles was also illustrated by the numerical results, which showed that significant levels of supersaturation exist in the flame for several of the important iron-containing intermediates. This particle formation is favored in the lower temperature stabilization region of the cup-burner flames, as compared to the higher relevant temperatures of previously described counterflow diffusion flames. The results of this study indicate that the appropriate flame configuration for evaluating the effectiveness of some fire suppression agents must be carefully considered, since in those cases, different flame configurations can switch the relative performance of an agent by an order of magnitude. (C) 2004 The Combustion Institute. Published by Elsevier Inc. All rights reserved. C1 NIST, Fire Sci Div, Gaithersburg, MD 20899 USA. Innovat Sci Solut Inc, Dayton, OH 45440 USA. NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. RP Linteris, GT (reprint author), NIST, Fire Sci Div, 100 Bur Dr,Stop 8665, Gaithersburg, MD 20899 USA. EM linteris@nist.gov NR 64 TC 52 Z9 59 U1 0 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD JUL PY 2004 VL 138 IS 1-2 BP 78 EP 96 DI 10.1016/j.combustflame.2004.04.003 PG 19 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 836KD UT WOS:000222553500007 ER PT J AU Morscher, GN AF Morscher, GN TI Stress-dependent matrix cracking in 2D woven SiC-fiber reinforced melt-infiltrated SiC matrix composites SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE ceramic matrix composites; stress-strain behavior; matrix cracking; acoustic emission ID STRAIN BEHAVIOR; SIC/SIC COMPOSITES; DAMAGE AB The matrix cracking of a variety of SiC/SiC composites has been characterized for a wide range of constituent variation. These composites were fabricated by the two-dimensional lay-up of 0/90 five-harness satin fabric consisting of Sylramic fiber tows that were then chemical vapor infiltrated (CVI) with BN, CVI with SiC, slurry infiltrated with SiC particles followed by molten infiltration of Si. The composites varied in number of plies, the number of tows per length, thickness, and the effective-size of the tows. This resulted in composites with a fiber volume fraction in the load-bearing direction that ranged from 0.12 to 0.20. Matrix cracking was monitored with modal acoustic emission in order to estimate the stress-dependent distribution of matrix cracks. It was found that the general matrix crack properties of this system could be fairly well characterized by assuming that no matrix cracks originated in the load-bearing fiber, interphase, chemical vapor infiltrated SiC tow-minicomposites, i.e., all matrix cracks originate in the 90degrees tow regions or the large unreinforced SiC-Si matrix regions. Also, it was determined that the higher fiber-count tow composites had a much narrower stress range for matrix cracking compared to the standard tow size composites. (C) 2003 Elsevier Ltd. All rights reserved. C1 Ohio Aerosp Inst, Brookpark, OH USA. RP Morscher, GN (reprint author), NASA, Glenn Res Ctr, Ohio Space Inst, Lewis Field,MS-106-5, Cleveland, OH 44135 USA. EM gregory.n.morscher@grc.nasa.gov NR 25 TC 68 Z9 72 U1 4 U2 22 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PD JUL PY 2004 VL 64 IS 9 BP 1311 EP 1319 DI 10.1016/j.compscitech.2003.10.022 PG 9 WC Materials Science, Composites SC Materials Science GA 821ZR UT WOS:000221502700021 ER PT J AU Willis, P Haines, B Berthias, JP Sengenes, P Le Mouel, JL AF Willis, P Haines, B Berthias, JP Sengenes, P Le Mouel, JL TI Behavior of the DORIS/Jason oscillator over the South Atlantic Anomaly SO COMPTES RENDUS GEOSCIENCE LA French DT Article DE satellite geodesy; orbit determination; DORIS; South Atlantic Anomaly; SAA; Jason ID TERRESTRIAL REFERENCE FRAME; DORIS; ORBIT; MISSION AB We point out an acceleration of the DORIS clock on-board the Jason satellite during passes over the South Atlantic Anomaly (SAA). When this effect is ignored in the current geodetic positioning of the DORIS stations, derived coordinates show almost linear trends in time, corresponding to anomalous horizontal and vertical velocities of the order of I m yr(-1). We propose a simple scientific explanation of this physical phenomenon that is corroborated by direct Jason/TOPEX clock comparisons with respect to the DORIS master beacons in Kourou and Toulouse. (C) 2004 Academie des sciences. Publie par Elsevier SAS. Tous droits reserves. C1 Inst Geog Natl, Direct Tech, F-94160 St Mande, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Ctr Natl Etud Spatiales, F-31401 Toulouse 4, France. Inst Phys Globe, F-75252 Paris 05, France. RP Willis, P (reprint author), Inst Geog Natl, Direct Tech, 2,Av Pasteur,BP 68, F-94160 St Mande, France. EM Pascal.R.Willis@jpl.nasa.gov RI Willis, Pascal/A-8046-2008 OI Willis, Pascal/0000-0002-3257-0679 NR 15 TC 70 Z9 70 U1 0 U2 2 PU ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS PA 23 RUE LINOIS, 75724 PARIS, FRANCE SN 1631-0713 J9 CR GEOSCI JI C. R. Geosci. PD JUL PY 2004 VL 336 IS 9 BP 839 EP 846 DI 10.1016/j.crte.2004.01.004 PG 8 WC Geosciences, Multidisciplinary SC Geology GA 839GN UT WOS:000222771700009 ER PT J AU Kim, SB AF Kim, SB TI Eliminating extrapolation using point distribution criteria in scattered data interpolation SO COMPUTER VISION AND IMAGE UNDERSTANDING LA English DT Article DE interpolation; extrapolation; image segmentation; image matching; digital elevation model; surface reconstruction ID SMOOTH INTERPOLATION; IMAGE INTERPOLATION; LARGE SETS; DEFORMATIONS AB Extrapolation off the boundaries of scattered data is an intrinsic feature of interpolation. However, extrapolation causes serious problems in stereo-vision and mapping, which has not been investigated carefully. In this paper, we present novel schemes to eliminate the extrapolation effects. We choose a sample application of the generation of a digital elevation model (DEM) to demonstrate the development of the schemes and to assess their performance. As a first step, we devise point distribution criteria, namely COG (center-of-gravity) and ECI (empty-center-index), and apply rigorous and robust elimination based on the criteria. The COG and ECI criteria exploit the characteristics of extrapolation, that scattered points are distributed unevenly or on the edge of a search disc of interpolation. Next, the hole-fill segmentation counterbalances excessive elimination by the COG and ECI elimination. Finally, the noise-remove segmentation compensates for incomplete performance of the COG and ECI elimination. The qualitative and quantitative assessments of the final DEMs reveal that extrapolation effects have been eliminated successfully. Compared with other methods, the proposed schemes are computationally fast and applicable to a wide range of interpolation techniques. (C) 2004 Elsevier Inc. All rights reserved. C1 Korea Adv Inst Sci & Technol, Satellite Technol Res Ctr, Taejon, South Korea. RP Kim, SB (reprint author), CALTECH, Jet Prop Lab, MS 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM sk@pacific.jpl.nasa.gov NR 33 TC 3 Z9 3 U1 1 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1077-3142 J9 COMPUT VIS IMAGE UND JI Comput. Vis. Image Underst. PD JUL PY 2004 VL 95 IS 1 BP 30 EP 53 DI 10.1016/j.eviu.2003.12.001 PG 24 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 833CL UT WOS:000222313900002 ER PT J AU Herwitz, SR Johnson, LF Dunagan, SE Higgins, RG Sullivan, DV Zheng, J Lobitz, BM Leung, JG Gallmeyer, BA Aoyagi, M Slye, RE Brass, JA AF Herwitz, SR Johnson, LF Dunagan, SE Higgins, RG Sullivan, DV Zheng, J Lobitz, BM Leung, JG Gallmeyer, BA Aoyagi, M Slye, RE Brass, JA TI Imaging from an unmanned aerial vehicle: agricultural surveillance and decision support SO COMPUTERS AND ELECTRONICS IN AGRICULTURE LA English DT Article DE unmanned aerial vehicle; Pathfinder-Plus UAV; multispectral imaging; local area network; ripeness monitoring; weed mapping; fertigation; coffee ID MANAGEMENT AB In September 2002, NASA's solar-powered Pathfinder-Plus unmanned aerial vehicle (UAV) was used to conduct a proof-of-concept mission in US national airspace above the 1500 ha plantation of the Kauai Coffee Company in Hawaii. While in national airspace, the transponder-equipped UAV was supervised by regional air traffic controllers and treated like a conventionally piloted aircraft. High resolution color and multispectral imaging payloads, both drawing from the aircraft's solar power system, were housed in exterior-mounted environmental pressure pods. A local area network (LAN) using unlicensed radio frequency was used for camera control and downlink of image data at rates exceeding 5 Mbit s(-1). A wide area network (WAN) allowed a project investigator stationed on the US mainland to uplink control commands during part of the mission. Images were available for enhancing, printing, and interpretation within minutes of collection. The color images were useful for mapping invasive weed outbreaks and for revealing irrigation and fertilization anomalies. Multispectral-imagery was related to mature fruit harvest from certain fields with significant fruit display on the tree canopy exterior. During 4 h "loitering" above the plantation, ground-based pilots were able to precisely navigate the UAV along pre-planned flightlines, and also perform spontaneous maneuvers under the direction of the project scientist for image collection in cloud-free zones. Despite the presence of ground-obscuring cumulus cloud cover of ca. 70% during the image collection period, the UAV's maneuvering capability ultimately enabled collection of cloud-free imagery throughout most of the plantation. The mission demonstrated the capability of a slow-flying UAV, equipped with downsized imaging systems and line-of-sight telemetry, to monitor a localized agricultural region for an extended time period. The authors suggest that evolving long-duration (weeks to months) UAVs stand to make a valuable future contribution to regional agricultural resource monitoring. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. Clark Univ, Grad Sch Geog, Worcester, MA 01610 USA. NASA, UAV Applicat Ctr, Moffett Field, CA 94035 USA. Calif State Univ, Moffett Field, CA 94035 USA. NASA, Dryden Flight Res Ctr, Technol Dev Branch, Moffett Field, CA 94035 USA. RP Herwitz, SR (reprint author), NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Mail Stop 242-2, Moffett Field, CA 94035 USA. EM sherwitz@mail.arc.nasa.gov NR 20 TC 123 Z9 129 U1 9 U2 98 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0168-1699 J9 COMPUT ELECTRON AGR JI Comput. Electron. Agric. PD JUL PY 2004 VL 44 IS 1 BP 49 EP 61 DI 10.1016/j.compag.2004.02.006 PG 13 WC Agriculture, Multidisciplinary; Computer Science, Interdisciplinary Applications SC Agriculture; Computer Science GA 836KB UT WOS:000222553300004 ER PT J AU Gorti, S Forsythe, EL Pusey, ML AF Gorti, S Forsythe, EL Pusey, ML TI Kinetic roughening and energetics of tetragonal lysozyme crystal growth SO CRYSTAL GROWTH & DESIGN LA English DT Article ID EGG-WHITE LYSOZYME; CRITICAL-BEHAVIOR; PROTEIN; RATES; FACE; CRYSTALLIZATION; NUCLEATION; MODEL; PH; TEMPERATURE AB Lysozyme crystal growth rates over 5 orders of magnitude in range can be described using a layer-by-layer model in which growth occurs by 2D nucleation on the crystal surface. Upon the basis of the 2D nucleation model of layer growth, the effective barrier for growth was determined to be gamma = 1.3 +/- 0.3 x 10(-13) erg/molecule, corresponding to a barrier of 3.2 +/- 0.7 k(B)T, at 22 degreesC. For solution supersaturation, In c/c(eq) greater than or equal to 1.9 +/- 0.2, the nucleation model would not predict or consistently estimate the highest observable crystal growth rates. As such, a kinetic roughening hypothesis in which crystal growth occurs by a continuous mode was implemented for all growth rate data obtained above In c(r)/c(eq) greater than or equal to 2. That is, independent of the solution conditions that vary with buffer pH, temperature, or precipitant concentration, crystal growth occurs by the continuous addition of molecules anywhere on the crystal surface, above a roughening solution supersaturation. The energy barrier, E-c for the continuous growth process is 6.1 +/- 0.4 x 10(-13) erg/molecule or 15 +/- 11 kBT at 22 degreesC). C1 NASA, Huntsville, AL 35812 USA. NASA, MSFC, BAE SYST, Phys & Biol Sci Lab, Huntsville, AL 35812 USA. RP Gorti, S (reprint author), NASA, Huntsville, AL 35812 USA. EM sridhar.gorti-1@nasa.gov NR 34 TC 17 Z9 17 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1528-7483 J9 CRYST GROWTH DES JI Cryst. Growth Des. PD JUL-AUG PY 2004 VL 4 IS 4 BP 691 EP 699 DI 10.1021/cg034164d PG 9 WC Chemistry, Multidisciplinary; Crystallography; Materials Science, Multidisciplinary SC Chemistry; Crystallography; Materials Science GA 836KG UT WOS:000222553800010 ER PT J AU Hornby, GS AF Hornby, GS TI Functional scalability through generative representations: the evolution of table designs SO ENVIRONMENT AND PLANNING B-PLANNING & DESIGN LA English DT Article ID CELLULAR INTERACTIONS; MATHEMATICAL MODELS; SHAPE; FILAMENTS; INPUTS AB One of the main limitations for the functional scalability of automated design systems is the representation used for encoding designs. I argue that generative representations, those which are capable of reusing elements of the encoded design in the translation to the actual artifact, are better suited for automated design because reuse of building blocks captures some design dependencies and improves the ability to make large changes in design space. To support this argument I compare a generative and a nongenerative representation on a table-design problem and find that designs evolved with the generative representation have higher fitness and a more regular structure. Additionally the generative representation was found to capture better the height dependency between table legs and also produced a wider range of table designs. C1 NASA, Ames Res Ctr, QSS Grp Inc, Moffett Field, CA 94035 USA. RP Hornby, GS (reprint author), NASA, Ames Res Ctr, QSS Grp Inc, Mail Stop 269-3, Moffett Field, CA 94035 USA. EM hornby@email.arc.nasa.gov NR 44 TC 24 Z9 24 U1 0 U2 5 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0265-8135 J9 ENVIRON PLANN B JI Environ. Plan. B-Plan. Des. PD JUL PY 2004 VL 31 IS 4 BP 569 EP 587 DI 10.1068/b3015 PG 19 WC Environmental Studies SC Environmental Sciences & Ecology GA 837AW UT WOS:000222599200007 ER PT J AU Hogrefe, C Rosenzweig, C Kinney, P Rosenthal, J Knowlton, K Lynn, B Patz, J Bell, M AF Hogrefe, C Rosenzweig, C Kinney, P Rosenthal, J Knowlton, K Lynn, B Patz, J Bell, M TI Health impacts from climate-change induced changes in ozone levels in 85 United States cities SO EPIDEMIOLOGY LA English DT Meeting Abstract CT 16th Conference of the International-Society-for-Environmental-Epidemiology CY AUG 01-04, 2004 CL New York, NY SP NYU Sch Med, UMDNJ Robert Wood Johnson Med Sch C1 SUNY Albany, Albany, NY 12222 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Columbia Univ, New York, NY 10027 USA. Johns Hopkins Bloomberg Sch Publ Hlth, Baltimore, MD USA. Yale Univ, New Haven, CT 06520 USA. RI Kinney, Patrick/H-7914-2012 NR 0 TC 2 Z9 2 U1 1 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1044-3983 J9 EPIDEMIOLOGY JI Epidemiology PD JUL PY 2004 VL 15 IS 4 BP S94 EP S95 DI 10.1097/00001648-200407000-00236 PG 2 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 834GO UT WOS:000222399800237 ER PT J AU Knowlton, K Rosenzweig, C Goldberg, R Lynn, B Gaffin, S Hogrefe, C Civerolo, K Ku, JY Solecki, W Small, C Oliveri, C Cox, J Rosenthal, J Kinney, PL AF Knowlton, K Rosenzweig, C Goldberg, R Lynn, B Gaffin, S Hogrefe, C Civerolo, K Ku, JY Solecki, W Small, C Oliveri, C Cox, J Rosenthal, J Kinney, PL TI Evaluating global climate change impacts on local health across a diverse urban region SO EPIDEMIOLOGY LA English DT Meeting Abstract CT 16th Conference of the International-Society-for-Environmental-Epidemiology CY AUG 01-04, 2004 CL New York, NY SP NYU Sch Med, UMDNJ Robert Wood Johnson Med Sch C1 Columbia Univ, Mailman Sch Publ Hlth, New York, NY 10027 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Lamont Doherty Earth Observ, Palisades, NY USA. Montclair State Univ, Montclair, NJ 07043 USA. RI Kinney, Patrick/H-7914-2012 NR 0 TC 6 Z9 7 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1044-3983 J9 EPIDEMIOLOGY JI Epidemiology PD JUL PY 2004 VL 15 IS 4 BP S100 EP S100 DI 10.1097/00001648-200407000-00251 PG 1 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 834GO UT WOS:000222399800251 ER PT J AU Patz, J Frumkin, H Klein, M Bell, M Ellis, H Hogrefe, C Rosenzweig, C Kinney, P AF Patz, J Frumkin, H Klein, M Bell, M Ellis, H Hogrefe, C Rosenzweig, C Kinney, P TI Childhood asthma projections for Atlanta under a future climate change scenario SO EPIDEMIOLOGY LA English DT Meeting Abstract CT 16th Conference of the International-Society-for-Environmental-Epidemiology CY AUG 01-04, 2004 CL New York, NY SP NYU Sch Med, UMDNJ Robert Wood Johnson Med Sch C1 Johns Hopkins Bloomberg Sch Publ Hlth, Baltimore, MD USA. Emory Univ, Rollins Sch Publ Hlth, Atlanta, GA 30322 USA. Yale Univ, Sch Forestry & Environm Studies, New Haven, CT 06520 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Mailman Sch Publ Hlth, New York, NY 10027 USA. RI Kinney, Patrick/H-7914-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1044-3983 J9 EPIDEMIOLOGY JI Epidemiology PD JUL PY 2004 VL 15 IS 4 BP S97 EP S97 DI 10.1097/00001648-200407000-00243 PG 1 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 834GO UT WOS:000222399800244 ER PT J AU Boykin, TB Klimeck, G AF Boykin, TB Klimeck, G TI The discretized Schrodinger equation and simple models for semiconductor quantum wells SO EUROPEAN JOURNAL OF PHYSICS LA English DT Article AB The discretized Schrodinger equation is one of the most commonly employed methods for solving one-dimensional quantum mechanics problems on the computer, yet many of its characteristics remain poorly understood. The differences with the continuous Schrodinger equation are generally viewed as shortcomings of the discrete model and are typically described in purely mathematical terms. This is unfortunate since the discretized equation is more productively viewed from the perspective of solid-state physics, which naturally links the discrete model to realistic semiconductor quantum wells and nanoelectronic devices. While the relationship between the discrete model and a one-dimensional tight-binding model has been known for some time, the fact that the discrete Schrodinger equation admits analytic solutions for quantum wells has gone unnoted. Here we present a solution to this new analytically solvable problem. We show that the differences between the discrete and continuous models are due to their fundamentally different bandstructures, and present evidence for our belief that the discrete model is the more physically reasonable one. C1 Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Purdue Univ, Sch Elect & Comp Engn, Network Computat Nanotechnol, W Lafayette, IN 47907 USA. RP Boykin, TB (reprint author), Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. RI Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 10 TC 21 Z9 21 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0143-0807 J9 EUR J PHYS JI Eur. J. Phys. PD JUL PY 2004 VL 25 IS 4 BP 503 EP 514 AR PII S0143-0807(04)78149-0 DI 10.1088/0143-0807/25/4/006 PG 12 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 843JY UT WOS:000223076100006 ER PT J AU Holstein, GR Martinelli, GP Boyle, R Rabbitt, RD Highstein, SM AF Holstein, GR Martinelli, GP Boyle, R Rabbitt, RD Highstein, SM TI Ultrastructural observations of efferent terminals in the crista Ampullaris of the toadfish, opsanus tau (vol 155, pg 265, 2004) SO EXPERIMENTAL BRAIN RESEARCH LA English DT Correction DE vestibular morphology; inner ear; semicircular canal; nervous system; balance ID GENE-RELATED PEPTIDE; SEMICIRCULAR CANAL AFFERENTS; TURTLE POSTERIOR-CRISTA; VESTIBULAR HAIR-CELLS; FROG LABYRINTH; HORSERADISH-PEROXIDASE; FINE-STRUCTURE; INNER-EAR; SYNAPTIC TRANSMISSION; NERVE-TERMINALS AB The present study was conducted to visualize the ultrastructural features of vestibular efferent boutons in the oyster toadfish, Opsanus tau. The crista ampullaris of the horizontal semicircular canal was processed for and examined by routine transmission electron microscopy. The results demonstrate that such boutons vary in size and shape, and contain a heterogeneous population of lucent vesicles with scattered dense core vesicles. Efferent contacts with hair cells are characterized by local vesicle accumulations in the presynaptic terminal and a subsynaptic cistern in the postsynaptic region of the hair cell. Serial efferent to hair cell to afferent synaptic arrangements are common, particularly in the central portion of the crista. However, direct contacts between efferent terminals and afferent neurites were not observed in our specimens. The existence of serial synaptic contacts, often with a row of vesicles in the efferent boutons lining the efferent-afferent membrane apposition, suggests that the efferent influence on the crista may involve both synaptic and nonsynaptic, secretory mechanisms. Further, it is suggested that differences in more subtle aspects of synaptic architecture and/or transmitter and receptor localization and interaction may render the efferent innervation of the peripheral crista less effective in influencing sensory processing. C1 Mt Sinai Sch Med, Dept Neurol, New York, NY 10029 USA. NASA, Ames BioVIS Technol Ctr, Moffett Field, CA 94035 USA. Univ Utah, Dept Bioengn, Salt Lake City, UT 84112 USA. Washington Univ, Dept Otolaryngol & Neurobiol, St Louis, MO USA. Marine Biol Lab, Woods Hole, MA 02543 USA. RP Holstein, GR (reprint author), Mt Sinai Sch Med, Dept Neurol, 1 Gustave L Levy Pl,Box 1140, New York, NY 10029 USA. EM gay.holstein@mssm.edu FU NIDCD NIH HHS [P01 DC-01837] NR 81 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0014-4819 J9 EXP BRAIN RES JI Exp. Brain Res. PD JUL PY 2004 VL 157 IS 1 BP 128 EP 136 DI 10.1007/s00221-004-1898-x PG 9 WC Neurosciences SC Neurosciences & Neurology GA 827FK UT WOS:000221884600015 PM 15318400 ER PT J AU Tebbe, PA Loyalka, SK Duval, WMB AF Tebbe, PA Loyalka, SK Duval, WMB TI Finite element modeling of asymmetric and transient flowfields during physical vapor transport SO FINITE ELEMENTS IN ANALYSIS AND DESIGN LA English DT Article DE materials processing; transient convection; physical vapor transport ID CONVECTIVE INSTABILITIES; CRYSTAL-GROWTH; AMPOULES AB We validate a finite element analysis created in FIDAP for the solution of the complex-coupled equations which describe physical vapor transport (PVT). PVT is a common method used to produce certain types of materials including semiconductors. Experimental and computational evidence suggests that the PVT growth process exhibits both asymmetric and transient oscillatory flowfield behavior. Results demonstrate various transient regimes, each with its own evolution towards an asymmetric flow structure. In addition, oscillatory flowfields which would greatly affect product quality have been numerically captured. Comparisons with theoretical and numerical results indicate that the finite element model is capable of predicting both steady-state asymmetric and transient flowfields which validates the numerical model for these complex flows. (C) 2003 Elsevier B.V. All rights reserved. C1 New Coll, Dept Engn, Ewing, NJ 08628 USA. Univ Missouri, Particulate Syst Res Ctr, Columbia, MO 65211 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Tebbe, PA (reprint author), New Coll, Dept Engn, Ewing, NJ 08628 USA. EM tebbe@tcnj.edu NR 29 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-874X J9 FINITE ELEM ANAL DES JI Finite Elem. Anal. Des. PD JUL PY 2004 VL 40 IS 11 BP 1499 EP 1519 DI 10.1016/j.finel.2003.09.003 PG 21 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA 827TS UT WOS:000221924500013 ER PT J AU Taggart, SJ O'Clair, CE Shirley, TC Mondragon, J AF Taggart, SJ O'Clair, CE Shirley, TC Mondragon, J TI Estimating dungeness crab (Cancer magister) abundance: crab pots and dive transects compared SO FISHERY BULLETIN LA English DT Article ID SOUTHEASTERN ALASKA; POPULATION BEHAVIOR; DYNAMICS; CATCHES; TRENDS; TRAPS AB Dungeness crabs (Cancer magister) were sampled with commercial pots and counted by scuba divers on benthic transects at eight sites near Glacier Bay, Alaska. Catch per unit of effort (CPUE) from pots was compared to the density estimates from dives to evaluate the bias and power of the two techniques. Yearly sampling was conducted in two seasons: April and September, from 1992 to 2000. Male CPUE estimates from pots were significantly lower in April than in the following September; a step-wise regression demonstrated that season accounted for more of the variation in male CPUE than did temperature. In both April and September, pot sampling was significantly biased against females. When females were categorized as ovigerous and nonovigerous, it was clear that ovigerous females accounted for the majority of the bias because pots were not biased against nonovigerous females. We compared the power of pots and dive transects in detecting trends in populations and found that pots had much higher power than dive transects. Despite their low power, the dive transects were very useful for detecting bias in our pot sampling and in identifying the optimal times of year to sample so that pot bias could be avoided. C1 US Geol Survey, Alaska Sci Ctr, Glacier Bay Field Stn, Juneau, AK 99801 USA. Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. Univ Alaska Fairbanks, Juneau Ctr Fisheries & Ocean Sci, Sch Fisheries & Ocean Sci, Juneau, AK 99801 USA. RP Taggart, SJ (reprint author), US Geol Survey, Alaska Sci Ctr, Glacier Bay Field Stn, 3100 Natl Pk Rd, Juneau, AK 99801 USA. EM jim_taggart@usgs.gov NR 35 TC 12 Z9 13 U1 0 U2 2 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 2004 VL 102 IS 3 BP 488 EP 497 PG 10 WC Fisheries SC Fisheries GA 842UP UT WOS:000223030100008 ER PT J AU Fielding, EJ Wright, TJ Muller, J Parsons, BE Walker, R AF Fielding, EJ Wright, TJ Muller, J Parsons, BE Walker, R TI Aseismic deformation of a fold-and-thrust belt imaged by synthetic aperture radar interferometry near Shahdad, southeast Iran SO GEOLOGY LA English DT Article DE fold-and-thrust belts; faults; synthetic aperture radar interferometry; satellite measurements; elastic modeling ID LOMA-PRIETA EARTHQUAKE; TURKEY EARTHQUAKE; FAULT SYSTEM; GOWK FAULT; CHI-CHI; SLIP; CALIFORNIA; TECTONICS; TAIWAN; RANGE AB At depth, many fold-and-thrust belts are composed of a gently dipping, basal thrust fault and steeply dipping, shallower splay faults that terminate beneath folds at the surface. Movement on these buried faults is difficult to observe, but synthetic aperture radar (SAR) interferometry has imaged slip on at least 600 km(2) of the Shahdad basal-thrust and splay-fault network in southeast Iran. Approximately 70 mm of thrust motion on the 8degrees-dipping Shahdad basal thrust occurred 8-30 kin to the east of the 14 March 1998 Fandoqa earthquake (M-w = 6.6) that involved 1.6 in of oblique (strike slip and normal slip) displacement on a steeply dipping fault. That earthquake transferred stress to the Shahdad basal thrust and associated splays, triggering slip either immediately or in the following six months. Modeling shows that, to produce the observed surface deformation, the Shahdad faults must have accommodated a nearly complete release of the shear stress increase. This could be due to either low friction on the faults or deformation throughout a wedge of material that is everywhere close to failure. The anomalously small, magnitude of displacement on the Shahdad basal thrust and splay faults compared to the area of slip suggests a slip mechanism that is likely aseismic. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Oxford, COMET, Oxford OX1 3PR, England. Univ Oxford, Dept Earth Sci, Oxford OX1 3PR, England. Stanford Univ, Dept Geog & Environm Sci, Stanford, CA 94305 USA. Univ Cambridge, COMET, Bullard Labs, Cambridge CB2 0EZ, England. Univ Cambridge, Dept Earth Sci, Bullard Labs, Cambridge CB2 0EZ, England. RP Fielding, EJ (reprint author), CALTECH, Jet Prop Lab, MS 300-233,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Eric.J.Fielding@jpl.nasa.gov RI Walker, Richard/D-9908-2011; Wright, Tim/A-5892-2011; Parsons, Barry/K-4716-2012; NCEO, COMET+`/A-3443-2013; Fielding, Eric/A-1288-2007 OI Wright, Tim/0000-0001-8338-5935; Fielding, Eric/0000-0002-6648-8067 NR 23 TC 40 Z9 40 U1 0 U2 7 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD JUL PY 2004 VL 32 IS 7 BP 577 EP 580 DI 10.1130/G20452.1 PG 4 WC Geology SC Geology GA 835NP UT WOS:000222490800009 ER PT J AU Sauber, JM Molnia, BF AF Sauber, JM Molnia, BF TI Glacier ice mass fluctuations and fault instability in tectonically active Southern Alaska SO GLOBAL AND PLANETARY CHANGE LA English DT Article DE postglacial rebound; stress fields; induced earthquakes; Alaska; subduction zones; GPS; glaciers ID RESERVOIR-INDUCED SEISMICITY; BERING GLACIER; CRUSTAL DEFORMATION; SUBDUCTION ZONE; SEA-LEVEL; SURGE; EARTHQUAKE; MODEL; GULF; USA AB Across the plate boundary zone in south central Alaska, tectonic strain rates are high in a region that includes large glaciers undergoing wastage (glacier retreat and thinning) and surges. For the coastal region between the Bering and Malaspina Glaciers, the average ice mass thickness changes between 1995 and 2000 range from 1 to 5 m/year. These ice changes caused solid Earth displacements in our study region with predicted values of - 10 to 50 mm in the vertical and predicted horizontal displacements of 0-10 mm at variable orientations. Relative to stable North America, observed horizontal rates of tectonic deformation range from 10 to 40 mm/year to the north-northwest and the predicted tectonic uplift rates range from approximately 0 mm/year near the Gulf of Alaska coast to 12 mm/year further inland. The ice mass changes between 1995 and 2000 resulted in discernible changes in the Global Positioning System (GPS) measured station positions of one site (ISLE) located adjacent to the Bagley Ice Valley and at one site, DON, located south of the Bering Glacier terminus. In addition to modifying the surface displacements rates, we evaluated the influence ice changes during the Bering glacier surge cycle had on the background seismic rate. We found an increase in the number of earthquakes (M-L greater than or equal to 2.5) and seismic rate associated with ice thinning and a decrease in the number of earthquakes and seismic rate associated with ice thickening. These results support the hypothesis that ice mass changes can modulate the background seismic rate. During the last century, wastage of the coastal glaciers in the Icy Bay and Malaspina region indicates thinning of hundreds of meters and in areas of major retreat, maximum losses of ice thickness approaching 1 km. Between the 1899 Yakataga and Yakutat earthquakes (M-w = 8.1, 8.1) and prior to the 1979 St. Elias earthquake (M-s = 7.2), the plate interface below Icy Bay was locked and tectonic strain accumulated. We used estimated ice mass change during the 1899-1979 time period to calculate the change in the fault stability margin (FSM) prior to the 1979 St. Elias earthquake. Our results suggest that a cumulative decrease in the fault stability margin at seismogenic depths, due to ice wastage over 80 years, was large, up to similar to 2 MPa. Ice wastage would promote thrust faulting in events such as the 1979 earthquake and subsequent aftershocks. Published by Elsevier B.V. C1 NASA, Goddard Space Flight Ctr, Geodynam Branch, Terr Phys Lab, Greenbelt, MD 20771 USA. US Geol Survey, Earth Surface Proc Team, Reston, VA 20192 USA. RP Sauber, JM (reprint author), NASA, Goddard Space Flight Ctr, Geodynam Branch, Terr Phys Lab, Greenbelt, MD 20771 USA. EM Jeanne.M.Sauber-Rosenberg@nasa.gov; bmolnia@usgs.gov RI Sauber, Jeanne/D-7684-2012 NR 60 TC 35 Z9 37 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 2004 VL 42 IS 1-4 BP 279 EP 293 DI 10.1016/j.gloplacha.2003.11.012 PG 15 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 845ID UT WOS:000223234800019 ER PT J AU Raymond, CA Ivins, ER Heflin, MB James, TS AF Raymond, CA Ivins, ER Heflin, MB James, TS TI Quasi-continuous global positioning system measurements of glacial isostatic deformation in the Northern Transantarctic Mountains SO GLOBAL AND PLANETARY CHANGE LA English DT Article DE global positioning system; Antarctic glacial isostasy; mantle viscosity; Transantarctic Mountains; crustal motion; autonomous observatories ID ANTARCTIC ICE-SHEET; MASS-BALANCE; GPS DATA; PREDICTIONS; MAXIMUM; MOTION AB Global positioning system (GPS) measurements have been collected quasi-continuously between November 1996 and January 2001 at two autonomous GPS stations in the Northern Transantarctic Mountains. High-quality data from the two sites at Mt. Coates in the Dry Valleys and Mt. Cocks in the Royal Society Range have resolved significant horizontal motions. The vertical rate at Mt. Coates indicates an uplift of 4.5 +/- 2.3 mm/year, most likely due to glacial isostatic motion. Uplift at Mt. Coates deviates significantly from uplift predictions based on deglaciation models ICE-3G and ICE-4G, but is consistent with a model (D91-1.5) in which deglaciation persists up to the late Holocene. Crown Copyright (C) 2004 Published by Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Geol Survey Canada, Pacific Geosci Ctr, Sidney, BC V8L 4B2, Canada. RP Raymond, CA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM carol.raymond@jpl.nasa.gov RI James, Thomas/D-9301-2013 OI James, Thomas/0000-0001-7321-047X NR 33 TC 11 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 2004 VL 42 IS 1-4 BP 295 EP 303 DI 10.1016/.jgloplacha.2003.11.013 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 845ID UT WOS:000223234800020 ER PT J AU Donnellan, A Luyendyk, BP AF Donnellan, A Luyendyk, BP TI GPS evidence for a coherent Antarctic plate and for postglacial rebound in Marie Byrd Land SO GLOBAL AND PLANETARY CHANGE LA English DT Article DE Antarctica; GPS; postglacial rebound; tectonics ID WEST ANTARCTICA; ICE-SHEET; ROSS SEA; MOTION; RIFT; DEGLACIATION; PREDICTIONS; UPLIFT AB GPS measurements collected between 1999 and 2002 in Marie Byrd Land, West Antarctica indicate no significant present motion between East and West Antarctica greater than 1-2 mm/year. Low strain rates imply that the Ross Sea rift is either inactive or active at a very low rate. This result indicates that the two subcontinents are likely joined as a single coherent lithospheric plate. They could have been joined since the end of Adare Trough spreading in Oligocene time. The volcanic activity in the Ross Sea sector at present such as at Mount Erebus is most likely related to mantle upwelling and not associated with continental rifting. GPS measurements of vertical rates indicate postglacial rebound of up to 12 4 mm/year in western Marie Byrd Land (wMBL). Errors are scaled 1sigma. The rock uplift rates are consistent with postglacial rebound models of significant ice thinning in the easter, Ross Ice Shelf in the late Holocene. (C) 2004 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Santa Barbara, Dept Geol Sci, Santa Barbara, CA 93106 USA. RP Donnellan, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 183-335, Pasadena, CA 91109 USA. EM Andrea.Donnellan@jpl.nasa.gov; luyendyk@geol.ucsb.edu NR 22 TC 19 Z9 20 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 2004 VL 42 IS 1-4 BP 305 EP 311 DI 10.1016/j.gloplacha.2004.02.006 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 845ID UT WOS:000223234800021 ER PT J AU Yorio, NC Richards, JT Edney, SL Wilkinson, JO Stutte, GW Wheeler, RM AF Yorio, Neil C. Richards, Jeff T. Edney, Sharon L. Wilkinson, Joel O. Stutte, Gary W. Wheeler, Raymond M. TI Compatibility of Radish, Lettuce, and Bunching Onions Grown Hydroponically in a Mixed-crop System SO HORTSCIENCE LA English DT Meeting Abstract C1 [Yorio, Neil C.; Richards, Jeff T.; Edney, Sharon L.; Stutte, Gary W.] Dynamac Corp, Adv Life Support, Kennedy Space Ctr, FL 32899 USA. [Wilkinson, Joel O.] Texas A&M Univ, Coll Agr & Life Sci, College Stn, TX 77843 USA. [Wheeler, Raymond M.] NASA, Biol Sci Off, Kennedy Space Ctr, FL 32899 USA. NR 0 TC 0 Z9 0 U1 0 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 2004 VL 39 IS 4 BP 793 EP 793 PG 1 WC Horticulture SC Agriculture GA V81JW UT WOS:000205501200225 ER PT J AU Brooks, SM Esposito, LW Showalter, MR Throop, HB AF Brooks, SM Esposito, LW Showalter, MR Throop, HB TI The size distribution of Jupiter's main ring from Galileo imaging and spectroscopy SO ICARUS LA English DT Article DE planetary rings, jupiter; jupiter; photometry; infrared observations ID SATURNS F-RING; NEAR-INFRARED OBSERVATIONS; JOVIAN RING; RADIO OCCULTATION; PLANE CROSSINGS; PARTICLE-SIZE; NOVEMBER 1995; SYSTEM; PERFORMANCE; CALIBRATION AB Galileo's Solid State Imaging experiment (SSI) obtained 36 visible wavelength images of Jupiter's ring system during the nominal mission (Ockert-Bell et al.. 1999. Icarus 138, 188-213) and another 21 during the extended mission. The Near Infrared Mapping Spectrometer (NIMS) recorded an observation of Jupiter's main ring during orbit C3 at wavelengths from 0.7 to 5.2 mum; a second observation was attempted during orbit E4. We analyze the high phase angle NIMS and SSI observations to constrain the size distribution of the main ring's micron-sized dust population. This portion of the population is best constrained at high phase angles, as the light scattering behavior of small dust grains dominates at these geometries and contributions from larger ring particles are negligible. High phase angle images of the main ring obtained by the Voyager spacecraft covered phase angles between 173.8degrees and 176.9degrees (Showalter et al., 1987, Icarus 69, 458-498). Galileo images extend this range up to 178.6degrees. We model the Galileo phase curve and the ring spectra from the C3 NIMS ring observation as the combination of two power law distributions. Our analysis of the main ring phase curve and the NIMS spectra suggests the size distribution of the smallest ring particles is a power law with an index of 2.0 +/- 0.3 below a size of similar to15 mum that transitions to a power law with an index of 5.0 +/- 1.5 at larger sizes. This combined power law distribution, or "broken power law" distribution, yields a better fit to the NIMS data than do the power law distributions that have previously been fit to the Voyager imaging data (Showalter et al., 1987, Icarus 69, 458-498). The broken power law distribution reconciles the results of Showalter et al. (1987, Icarus 69, 458-498) and McMuldroch et al. (2000, Icarus 146, 1-11), who also analyzed the NIMS data, and can be considered as an obvious extension of a simple power law. This more complex size distribution could indicate that ring particle production rates and/or lifetimes vary with size and may relate to the physical processes that control their evolution. The significant near arm/far arm asymmetry reported elsewhere (see Showalter et al., 1987, Icarus 69, 458-498; Ockert-Bell et al. 1999. Icarus 138. 188-213) persists in the data even after the main ring is isolated in the SSI images. However, the sense of the asymmetry seen in Galileo images differs from that seen in Voyager images. We interpret this asymmetry as a broad-scale, azimuthal brightness variation. No consistent association with the magnetic field of Jupiter has been observed. It is possible that these longitudinal variations may be similar to the random brightness fluctuations observed in Saturn's F ring by Voyager (Smith et al., 1982, Science 215, 504-537) and during the 1995 ring plane crossings (Nicholson et al., 1996, Science 272, 509-515; Bosh and Rivkin, 1996, Science 272, 518-521; Poulet et al., 2000, Icarus 144, 135-148). Stochastic events may thus play a significant role in the evolution of the jovian main ring. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Stanford Univ, Ctr Radar Astron, Stanford, CA 94305 USA. SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. RP Brooks, SM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 230-205, Pasadena, CA 91109 USA. EM shawn.m.brooks@jpl.nasa.gov NR 52 TC 11 Z9 11 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JUL PY 2004 VL 170 IS 1 BP 35 EP 57 DI 10.1016/j.icarus.2004.03.003 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 830ZK UT WOS:000222162500004 ER PT J AU Vilas, F Jarvis, KS Barker, ES Lederer, SM Kelley, MS Owen, TC AF Vilas, F Jarvis, KS Barker, ES Lederer, SM Kelley, MS Owen, TC TI Iapetus dark and bright material: giving compositional interpretation some latitude SO ICARUS LA English DT Article DE spectroscopy; surfaces, satellites; satellites of Saturn; satellites, irregular ID UBV PHOTOMETRY; ORGANIC-MATTER; SOLAR-SYSTEM; LAPETUS; SPECTROPHOTOMETRY; SIDE; HYPERION; PHOEBE; ASTEROIDS; ORIGIN AB Narrowband reflectance spectra (0.53-1.0 mum) of Iapetus' leading and trailing sides were obtained in 2000 to test the presence of an absorption feature located near 0.67 mum seen in reflectance spectra of Iapetus' dark material and Hyperion's surface material. No feature was observed. The difference in reflectance across the UV/VIS/NIR spectral region, and the dependence of the presence or absence of this absorption feature on angular separation from the apex of Iapetus in its orbit, phase angle, and heliocentric distance (affecting temperature), were examined. A trend of increased reddening, and the presence of the absorption feature, correlate with an angular separation from the apex of less than or equal to approximately 10degrees. Spectral information is lost when the contribution of the bright water ice signal to the reflectance spectrum increases sufficiently. In order to optimize compositional studies of Iapetus, we encourage future ground-based and space-based spectral observations to maximize the concentration of dark material in the instrumental field of view. (C) 2004 Elsevier Inc. All rights reserved. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Lockheed Martin Space Operat, Houston, TX 77058 USA. Univ Texas, McDonald Observ, Austin, TX 78702 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Vilas, F (reprint author), NASA, Lyndon B Johnson Space Ctr, Code SR, Houston, TX 77058 USA. EM faith.vilas-1@nasa.gov NR 24 TC 5 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 0019-1035 J9 ICARUS JI Icarus PD JUL PY 2004 VL 170 IS 1 BP 125 EP 130 DI 10.1016/j.icarus.2004.01.016 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 830ZK UT WOS:000222162500009 ER PT J AU Emery, JP Brown, RH AF Emery, JP Brown, RH TI The surface composition of Trojan asteroids: constraints set by scattering theory SO ICARUS LA English DT Article DE asteroids, composition; Kuiper belt objects; radiative transfer; spectroscopy; surface, asteroids ID BIDIRECTIONAL REFLECTANCE SPECTROSCOPY; NEAR-INFRARED SPECTROSCOPY; INTERSTELLAR SILICATE MINERALOGY; CHARGED-PARTICLE IRRADIATION; OPTICAL-CONSTANTS; SPECTRAL REFLECTANCE; SOLAR-SYSTEM; PLANETARY SURFACES; INTIMATE MIXTURES; ALBEDO AB We present the results of spectral modeling of 17 Trojan asteroids. The surface composition of this group of objects (located just beyond the main belt, trapped in Jupiter's stable Lagrange points) remains uncertain due to an absence of diagnostic absorption features in their spectra. We quantitatively analyze spectra of these objects covering the range 0.3-4.0 mum using the formulation for scattering in a particulate medium developed by Hapke. Since the widest spectral range possible is desired to provide the most robust results, recently measured near-IR spectra are combined with previously published visible and near-IR data. These composite spectra are converted to and modeled in terms of geometric albedo to provide the additional constraint of the absolute brightness of the asteroids. It is important that this modeling is performed for a large number of objects, and results are derived based on trends among best-fit models. Under this rigorous examination, we find that it is unlikely that the red spectral slope is a result of organics on the surfaces, due mainly to the lack of absorptions in the L-band. Instead, anhydrous silicates adequately describe the spectral characteristics of this group of objects. A significant fraction of carbonaceous material is also likely present, but is not responsible for the red spectral slope in these models. Also, using these models. we estimate that these surfaces contain at most a few wt% of H2O ice and no more than 10-30 wt% of hydrated silicates. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RP Emery, JP (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM jemery@mail.arc.nasa.gov NR 65 TC 47 Z9 47 U1 0 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JUL PY 2004 VL 170 IS 1 BP 131 EP 152 DI 10.1016/j.icarus.2004.02.004 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 830ZK UT WOS:000222162500010 ER PT J AU Gerakines, PA Moore, MH Hudson, RL AF Gerakines, PA Moore, MH Hudson, RL TI Ultraviolet photolysis and proton irradiation of astrophysical ice analogs containing hydrogen cyanide SO ICARUS LA English DT Article DE ices; comets; composition; radiation chemistry; photochemistry; spectroscopy ID YOUNG STELLAR OBJECTS; O1 HALE-BOPP; INFRARED-SPECTRUM; INTERSTELLAR ICES; AQUEOUS-SOLUTIONS; UV PHOTOLYSIS; HCN; BAND; SPECTROSCOPY; BOMBARDMENT AB Hydrogen cyanide (HCN) has been identified in the gas phase of the interstellar medium as well as in the comae of several comets. Terrestrially, HCN is a key component in the synthesis of biologically important molecules such as amino acids. In this paper, we report the results of low-temperature (18 K) ice energetic processing experiments involving pure HCN and mixtures of HCN with H2O and NH3. Ice films, 0.1 to several microns in thickness, were exposed to either ultraviolet photons (110-250 nm) or 0.8-MeV protons to simulate the effects of space environments. Observed products include HCNO (isocyanic acid) NH4+ (ammonium ion), CN- (cyanide ion), OCN- (cyanate ion), HCONH2 (formamide), and species spectrally similar to HCN polymers. Product formation rates and HCN destruction rates were determined where possible. Results are discussed in terms of astrophysical situations in the ISM and the Solar System where HCN would likely play an important role in prebiotic chemistry. These results imply that if HCN is present in icy mixtures representative of the ISM or in comets, it will be quickly converted into other species in energetic environments; pure HCN seems to be polymerized by incident radiation. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Alabama, Dept Phys, Astro & Solar Syst Phys Program, Birmingham, AL 35294 USA. NASA, Goddard Space Flight Ctr, Astrochem Branch, Greenbelt, MD 20771 USA. Eckerd Coll, Dept Chem, St Petersburg, FL 33733 USA. RP Gerakines, PA (reprint author), Univ Alabama, Dept Phys, Astro & Solar Syst Phys Program, 1300 Univ Blvd,CH 310, Birmingham, AL 35294 USA. EM gerak@uab.edu RI Gerakines, Perry/B-9705-2009; Hudson, Reggie/E-2335-2012; Gerakines, Perry/D-2226-2012 OI Gerakines, Perry/0000-0002-9667-5904 NR 43 TC 65 Z9 65 U1 1 U2 22 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 2004 VL 170 IS 1 BP 202 EP 213 DI 10.1016/j.icarus.2004.02.005 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 830ZK UT WOS:000222162500015 ER PT J AU Fouchet, T Orton, G Irwin, PGJ Calcutt, SB Nixon, CA AF Fouchet, T Orton, G Irwin, PGJ Calcutt, SB Nixon, CA TI Upper limits on hydrogen halides in Jupiter from Cassini/CIRS observations SO ICARUS LA English DT Article DE Jupiter, atmosphere; atmospheres, composition; abundances, atmospheres ID PROBE MASS-SPECTROMETER; OUTER PLANETS; GIANT PLANETS; SATURN; ATMOSPHERE; ABSORPTION; LINES; TEMPERATURE; PHOSPHINE; CHLORIDE AB We have determined the following upper limits for the mole fraction of hydrogen halides in Jupiter's atmosphere from Cassini/CIRS observations: [HF] < 2.7 x 10(-11), [HCl] < 2.3 x 10(-9), [HBr] < 1.0 x 10(-9). [HI] < 7.6 x 10-9. These limits are smaller than solar composition for HF and HCl, and support the halogens' condensation in ammonium salts predicted by thermochemical models for the upper jovian troposphere. (C) 2004 Published by Elsevier Inc. C1 Observ Paris, LESIA, F-92195 Meudon, France. Univ Oxford, Clarendon Lab, AOPP, Oxford OX1 3PU, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Maryland, College Pk, MD 20742 USA. RP Fouchet, T (reprint author), Observ Paris, LESIA, 5 Pl Jules Janssen, F-92195 Meudon, France. EM thierry.fouchet@obspm.fr RI Nixon, Conor/A-8531-2009; Fouchet, Thierry/C-6374-2017; OI Nixon, Conor/0000-0001-9540-9121; Fouchet, Thierry/0000-0001-9040-8285; Calcutt, Simon/0000-0002-0102-3170; Irwin, Patrick/0000-0002-6772-384X NR 27 TC 7 Z9 7 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JUL PY 2004 VL 170 IS 1 BP 237 EP 241 DI 10.1016/j.icarus.2004.03.013 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 830ZK UT WOS:000222162500019 ER PT J AU Stoica, A Zebulurn, RS Guo, X Keyrneulen, D Ferguson, MI Duong, V AF Stoica, A Zebulurn, RS Guo, X Keyrneulen, D Ferguson, MI Duong, V TI Taking evolutionary circuit design from experimentation to implementation: some useful techniques and a silicon demonstration SO IEE PROCEEDINGS-COMPUTERS AND DIGITAL TECHNIQUES LA English DT Article ID ARTIFICIAL EVOLUTION; ELECTRONICS AB Current techniques in evolutionary synthesis of analogue and digital circuits designed at transistor level have focused on achieving the desired functional response, without paying sufficient attention to issues needed for a practical implementation of the resulting solution. No silicon fabrication of circuits with topologies designed by evolution has been done before, leaving open questions on the feasibility of the evolutionary circuit design approach, as well as on how high-performance, robust, or portable such designs could be when implemented in hardware. It is argued that moving from evolutionary 'design-for experimentation' to 'design-for-implementation' requires, beyond inclusion in the fitness function of measures indicative of circuit evaluation factors such as power consumption and robustness to temperature variations, the addition of certain evaluation techniques that are not common in conventional design. Several such techniques that were found to be useful in evolving designs for implementation are presented; some are general, and some are particular to the problem domain of transistor-level logic design, used here as a target application. The example used here is a multifunction NAND/NOR logic gate circuit, for which evolution obtained a creative circuit topology more compact than what has been achieved by multiplexing a NAND and a NOR gate. The circuit was fabricated in a 0.5 mum CMOS technology and silicon tests showed good correspondence with the simulations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Chromatech, Alameda, CA 94501 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 15 TC 35 Z9 35 U1 0 U2 1 PU INST ENGINEERING TECHNOLOGY-IET PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 1350-2387 J9 IEE P-COMPUT DIG T JI IEE Proc.-Comp. Digit. Tech. PD JUL PY 2004 VL 151 IS 4 BP 295 EP 300 DI 10.1049/ip-cdt:20040503 PG 6 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA 842IL UT WOS:000222997000005 ER PT J AU Liu, ZY McGill, M Hu, YX Hostetler, C Vaughan, M Winker, D AF Liu, Zhaoyan McGill, Matthew Hu, Yongxiang Hostetler, Chris Vaughan, Mark Winker, David TI Validating Lidar Depolarization Calibration Using Solar Radiation Scattered by Ice Clouds SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS LA English DT Article DE Calibration; depolarization measurement; solar radiation; spaceborne lidar AB This letter proposes the use of solar background radiation scattered by ice clouds for validating space lidar depolarization calibration. The method takes advantage of the fact that the background light scattered by optically thick ice clouds is almost entirely unpolarized. The theory is examined with background light measurements acquired by the Cloud Physics Lidar. C1 [Liu, Zhaoyan] NASA, Ctr Atmospher Sci, Hampton Univ, Langley Res Ctr, Hampton, VA 23681 USA. [McGill, Matthew] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Vaughan, Mark] NASA, Langley Res Ctr, Sci Applicat Int Corp, Hampton, VA 23681 USA. RP Liu, ZY (reprint author), NASA, Ctr Atmospher Sci, Hampton Univ, Langley Res Ctr, Hampton, VA 23681 USA. EM z.liu@larc.nasa.gov; matthew.j.mcgill@nasa.gov; yongxiang.hu_1@nasa.gov; Chris.a.hostetler@nasa.gov; m.a.vaughan@larc.nasa.gov; David.m.winker@nasa.gov RI Liu, Zhaoyan/B-1783-2010; Hu, Yongxiang/K-4426-2012 OI Liu, Zhaoyan/0000-0003-4996-5738; FU National Aeronautics and Space Administration [23-622-43-03] FX This work was supported in part by the National Aeronautics and Space Administration Radiation Program under Grant 23-622-43-03. NR 20 TC 3 Z9 3 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1545-598X J9 IEEE GEOSCI REMOTE S JI IEEE Geosci. Remote Sens. Lett. PD JUL PY 2004 VL 1 IS 3 BP 157 EP 161 DI 10.1109/LGRS.2004.829613 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 V23EE UT WOS:000208325300003 ER PT J AU Filman, RE AF Filman, RE TI Not free, but relatively inexpensive SO IEEE INTERNET COMPUTING LA English DT Editorial Material C1 NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. RP Filman, RE (reprint author), NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. EM filman@computer.org NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1089-7801 J9 IEEE INTERNET COMPUT JI IEEE Internet Comput. PD JUL-AUG PY 2004 VL 8 IS 4 BP 4 EP 6 DI 10.1109/MIC.2004.1273478 PG 3 WC Computer Science, Software Engineering SC Computer Science GA 835SC UT WOS:000222504800001 ER PT J AU Soibel, A Capasso, F Gmachl, C Peabody, ML Sergent, AM Paiella, R Hwang, HY Sivco, DL Cho, AY Liu, HC Jirauschek, C Kartner, FX AF Soibel, A Capasso, F Gmachl, C Peabody, ML Sergent, AM Paiella, R Hwang, HY Sivco, DL Cho, AY Liu, HC Jirauschek, C Kartner, FX TI Active mode locking of broadband quantum cascade lasers SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE mode-locked lasers; pulse generation; pulsed laser; semiconductor lasers; ultrafast AB Active mode locking in broadband quantum cascade (QC) lasers with a repetition rate of about 14.3 GHz has been achieved through the modulation of the laser bias current. At low driving currents, the active mode locking in broadband QC lasers resembles the active mode locking in single-wavelength QC lasers, while at high driving currents, the mode locking properties are governed by the broad spectral gain of these lasers. At high bias currents, the active modulation excites Fabry-Perot modes across the entire gain spectrum from 6.7 to 7.4 mum, with clear evidence of mode locking. The spectral width of the optical gain in the broadband QC lasers exceeds 2 THz and indicates the potential for generating subpicosecond pulses. C1 Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. Boston Univ, Dept Elect & Comp Engn, Boston, MA 02215 USA. Univ Tokyo, Chiba 2778561, Japan. CNR, Inst Microstruct Sci, Ottawa, ON K1A R6, Canada. MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. MIT, Res Lab Elect, Cambridge, MA 02139 USA. RP Soibel, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Alexander.Soibel@jpl.nasa.gov; capasso@deas.harvard.edu RI Jirauschek, Christian/E-3039-2012; Hwang, Harold/I-6943-2012; Soibel, Alexander/A-1313-2007 NR 12 TC 15 Z9 15 U1 2 U2 13 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD JUL PY 2004 VL 40 IS 7 BP 844 EP 851 DI 10.1109/JQE.2004.830186 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 832OX UT WOS:000222277900002 ER PT J AU Schulman, JN Kolinko, V Morgan, M Martin, C Lovberg, J Thomas, S Zinck, J Boegeman, YK AF Schulman, JN Kolinko, V Morgan, M Martin, C Lovberg, J Thomas, S Zinck, J Boegeman, YK TI W-band direct detection circuit performance with Sb-heterostructure diodes SO IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS LA English DT Article DE backward diodes; millimeter-wave detectors; millimeter-wave diodes; millimeter-wave imaging ID BACKWARD DIODES AB W-band direct detection circuits have been designed and fabricated for use in a passive millimeter wave camera. The circuits are based on the recently developed Sb-heterostructure diode. We measure record voltage responsivities in test circuits, up to 8,000 mV/mW from 75 to 93 GHz, with input power from -50 to -30 dBm. Performance was similar in an actual camera frequency processor board with 128 tuned channels. 72% of detectors showed responsivity at or above 6,000 mV/mW and 3% of channels were above 10,000 mV/mW. Since tens of thousands of Sb-heterostructure diodes can be reproducibly and inexpensively fabricated, this demonstrates for the first time the feasibility of large-scale detector arrays utilizing zero bias direct detection circuitry. C1 LLC, HRL Labs, Malibu, CA 90265 USA. Trex Enterprises Corp, San Diego, CA 92121 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Schulman, JN (reprint author), LLC, HRL Labs, Malibu, CA 90265 USA. EM schulman@hrl.com NR 7 TC 18 Z9 18 U1 0 U2 3 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 2004 VL 14 IS 7 BP 316 EP 318 DI 10.1109/LMWC.2004.829259 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 835KA UT WOS:000222480400002 ER PT J AU Burke, EJ Shuttleworth, WJ Houser, PR AF Burke, EJ Shuttleworth, WJ Houser, PR TI Impact of horizontal and vertical heterogeneities on retrievals using multiangle microwave brightness temperature data SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE land surface; passive microwave; remote sensing; retrieval; soil moisture ID SOIL-MOISTURE; LAND; VARIABILITY; SIMULATION; RADIOMETRY; MODELS; WATER AB This paper investigates the impact of heterogeneity at the land surface on geophysical parameters retrieved from multiangle microwave brightness temperature data, such as would be obtained from the Soil Moisture and Ocean Salinity (SMOS) mission. Synthetic brightness temperature data were created using the Common Land (land surface) Model, coupled with a microwave emission model and set within the framework of the North American Land Data Assimilation System (NLDAS). Soil moisture, vegetation optical depth, and effective physical temperature were retrieved using a multiobjective calibration routine similar to the proposed SMOS retrieval algorithm for a typical on-axis range of look angles. The impact of heterogeneity both in the near-surface profiles of soil moisture and temperature and in the land cover on the accuracy of the retrievals was examined. There are significant errors in the retrieved parameters over regions with steep gradients in the near-surface soil moisture profile. These errors are approximately proportional to the difference in the soil water content between the top (at 0.7 cm) and second layer (at 2.7 cm) of the land surface model. The errors resulting from heterogeneity in the land cover are smaller and increase nonlinearly with increasing land-surface heterogeneity (represented by the standard deviation of the optical depth within the pixel). The most likely use of retrieved soil moisture is through assimilation into an LDAS for improved initiation of weather and climate models. Given that information on the soil moisture profile is already available within the LDAS, the error in the retrieved soil moisture as a result of the near-surface profile can be corrected for. The potential errors as a result of land-surface heterogeneity can also be assessed for use in the assimilation process. C1 Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. EM eleanor@hwr.arizona.edu RI Houser, Paul/J-9515-2013 OI Houser, Paul/0000-0002-2991-0441 NR 27 TC 5 Z9 5 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 EI 1558-0644 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JUL PY 2004 VL 42 IS 7 BP 1495 EP 1501 DI 10.1109/TGRS.2004.828922 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 838OT UT WOS:000222723400016 ER PT J AU Netanyahu, NS Le Moigne, J Masek, JG AF Netanyahu, NS Le Moigne, J Masek, JG TI Georegistration of Landsat data via robust matching of multiresolution features SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE approximation algorithms; Hausdorff distance; image registration; least median of squares estimator; point pattern matching; wavelet-based feature extraction ID IMAGE REGISTRATION; MISREGISTRATION; ALGORITHMS; ACCURACY; MODIS AB The goal of the project described in this paper is to build a prototype of an operational system, which will provide registration within subpixel accuracy of multitemporal Landsat data, acquired by either Landsat-5 or Landsat-7 Thematic Mapper instruments. Integrated within an automated mass processing system for Landsat data, the input to our registration system consists of scenes that have been geometrically and radiometrically corrected, as well as preprocessed for detection of clouds and cloud shadows. Such preprocessed scenes are then georegistered relative to a database of Landsat chips. This paper describes the entire registration process, including the use of landmark chips, feature extraction performed by an overcomplete wavelet representation, and feature matching using statistically robust techniques. Knowing the approximate longitudes and latitudes or the UTM coordinates of the four corners of each incoming scene, a subset of the chips that represent landmarks included in the scene are selected to perform the registration. For each of these selected landmark chips, a corresponding window is extracted from the incoming scene, and each chip-window pair is registered using a robust wavelet feature-matching methodology. Based on the transformations from the chip-window pairs, a global transformation is then computed for the entire scene using a variant of a robust least median of squares estimator. Empirical results of this registration process, which provided subpixel accuracy for several multitemporal scenes from different study areas, are presented and discussed. C1 Bar Ilan Univ, Dept Comp Sci, IL-52900 Ramat Gan, Israel. Univ Maryland, Ctr Automat Res, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Greenbelt, MD 20771 USA. RP Netanyahu, NS (reprint author), Bar Ilan Univ, Dept Comp Sci, IL-52900 Ramat Gan, Israel. EM nathan@cs.biu.ac.il; lemoigne@back-serv.gsfc.nasa.gov; jmasek@ltpmail.gsfc.nasa.gov RI Masek, Jeffrey/D-7673-2012 NR 43 TC 29 Z9 30 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 JUL PY 2004 VL 42 IS 7 BP 1586 EP 1600 DI 10.1109/TGRS.2004.826822 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 838OT UT WOS:000222723400025 ER PT J AU Hubona, GS Shirah, GW Jennings, DK AF Hubona, GS Shirah, GW Jennings, DK TI The effects of cast shadows and stereopsis on performing computer-generated spatial tasks SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART A-SYSTEMS AND HUMANS LA English DT Article DE computer interfaces; human factors; image size analysis; object detection; object recognition; position measurement; three-dimensional (3-D) displays; visualization ID VISUALIZATION; MOTION; GRAPHICS; DESIGN; DEPTH AB More powerful computer hardware and software has enabled the development of numerous depth-cue techniques to depict the three-dimensional (3-D) characteristics of computer-generated imagery. Particularly, the role of stereoscopic viewing in promoting the depth perception of objects in 3-D space has been widely studied. However, there has been little study of the use of cast shadows in this context, and few investigations of how computer-generated depth cues are perceptually integrated. To investigate these issues, subjects: 1) position a sphere to complete a directional vector/vector segment extending in space and 2) resize a sphere to match the perceived size of a second sphere displaced in space. Task accuracies and response times are recorded under the following conditions: 1) stereoscopic, and monoscopic, scene viewing; 2) objects casting zero, or one shadow; 3) flat, and zig-zag, background surface shapes; and 4) solid and checkerboard background surface textures. The results suggest that, of the cues considered, stereo viewing has a consistently beneficial effect on positioning and resizing spheres in depth. However, objects casting shadows improve positioning accuracy to a level afforded by stereo viewing. Finally, more complex scene backgrounds impair positioning and resizing task performances. Implications for the design of effective 3-D user interfaces are discussed. C1 Georgia State Univ, J Mack Robinson Coll Business, Dept Comp Informat Syst, Atlanta, GA 30302 USA. NASA, Goddard Space Flight Ctr, Sci Visualizat Studio, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Informat Syst, Baltimore, MD 21250 USA. RP Hubona, GS (reprint author), Georgia State Univ, J Mack Robinson Coll Business, Dept Comp Informat Syst, POB 4010, Atlanta, GA 30302 USA. EM ghubona@cis.gsu.edu; greg.shirah@gsfc.nasa.gov; djenni@umbc.edu NR 36 TC 7 Z9 7 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1083-4427 J9 IEEE T SYST MAN CY A JI IEEE Trans. Syst. Man Cybern. Paart A-Syst. Hum. PD JUL PY 2004 VL 34 IS 4 BP 483 EP 493 DI 10.1109/TSMCA.2004.826269 PG 11 WC Computer Science, Cybernetics; Computer Science, Theory & Methods SC Computer Science GA 830PS UT WOS:000222135600005 ER PT J AU Parnell, J Lee, P Cockell, CS Osinski, GR AF Parnell, J. Lee, P. Cockell, C. S. Osinski, G. R. TI Microbial colonization in impact-generated hydrothermal sulphate deposits, Haughton impact structure, and implications for sulphates on Mars SO INTERNATIONAL JOURNAL OF ASTROBIOLOGY LA English DT Article DE cyanobacteria; endoliths; gypsum; Haughton impact structure; impact craters; life on Mars; sulphates AB Hydrothermal gypsum deposits in the Haughton impact structure, Devon Island, Canada, contain microbial communities in an endolithic habitat within individual gypsum crystals. Cyanobacterial colonies occur as masses along cleavage planes, up to 5 cm from crystal margins. The crystals are transparent, so allow transmission of light for photosynthesis, while affording protection from dehydration and wind. The colonies appear to have modified their mineral host to provide additional space as they expanded. The colonies are black due to UV-screening pigments. The relative ease with which microbial colonization may be detected and identified in impact-generated sulphate deposits at Haughton suggests that analogous settings on other planets might merit future searches for biosignatures. The proven occurrence of sulphates on the Martian surface suggests that sulphate minerals should be a priority target in the search for life on Mars. Received 12 May 2004, accepted 7 July 2004 C1 [Parnell, J.] Univ Aberdeen, Dept Geol, Aberdeen AB24 3UE, Scotland. [Lee, P.] SETI Inst, Mars Inst, Moffett Field, CA 94035 USA. [Lee, P.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Cockell, C. S.] British Antarctic Survey, Cambridge CB3 0ET, England. [Osinski, G. R.] Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. RP Parnell, J (reprint author), Univ Aberdeen, Dept Geol, Aberdeen AB24 3UE, Scotland. EM J.Parnell@abdn.ac.uk FU NASA; NSERC FX We are grateful to the sponsors of the NASA Haughton-Mars Project for support of fieldwork. Anonymous reviews helped to improve the manuscript. Martin Baron is thanked for observations of fluid inclusions in the gypsum. Anne Wilkins supplied Fig. 4(d). Other essential technical support was provided by Barry Fulton and John Still. G. R. O. was funded through a NSERC grant to John Spray, University of New Brunswick. NR 53 TC 34 Z9 35 U1 0 U2 6 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 1473-5504 J9 INT J ASTROBIOL JI Int. J. Astrobiol. PD JUL PY 2004 VL 3 IS 3 BP 247 EP 256 DI 10.1017/S1473550404001995 PG 10 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA V22OI UT WOS:000208284100007 ER PT J AU Glavin, DP Dworkin, JP Lupisella, M Kminek, G Rummel, JD AF Glavin, D. P. Dworkin, J. P. Lupisella, M. Kminek, G. Rummel, J. D. TI Biological contamination studies of lunar landing sites: implications for future planetary protection and life detection on the Moon and Mars SO INTERNATIONAL JOURNAL OF ASTROBIOLOGY LA English DT Article DE Apollo; biological contamination; biomarkers; Luna; Mars; Moon; organic contamination; planetary protection; Ranger; spacecraft sterilization AB Chemical and microbiological studies of the impact of terrestrial contamination of the lunar surface during the Apollo missions could provide valuable data to help refine future Mars surface exploration plans and planetary protection requirements for a human mission to Mars. NASA and ESA have outlined new visions for solar system exploration that will include a series of lunar robotic missions to prepare for and support a human return to the Moon, and future human exploration of Mars and other destinations. Under the Committee on Space Research's (COSPAR's) current planetary protection policy for the Moon, no decontamination procedures are required for outbound lunar spacecraft. Nonetheless, future in situ investigations of a variety of locations on the Moon by highly sensitive instruments designed to search for biologically derived organic compounds would help assess the contamination of the Moon by lunar spacecraft and Apollo astronauts. These studies could also provide valuable 'ground truth' data for Mars sample return missions and help define planetary protection requirements for future Mars bound spacecraft carrying life detection experiments. Received 8 June 2004, accepted 24 June 2004 C1 [Glavin, D. P.; Dworkin, J. P.; Lupisella, M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Kminek, G.] European Space Agcy, NL-2200 AG Noordwijk, Netherlands. [Rummel, J. D.] NASA Headquarters, Sci Mission Directorate, Washington, DC 20546 USA. RP Glavin, DP (reprint author), NASA, Goddard Space Flight Ctr, Code 915,691 & 584, Greenbelt, MD 20771 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 FU NASA Astrobiology Institute FX We appreciate the helpful comments of Paul Mahaffy, Oliver Botta, Chris McKay and one anonymous reviewer. We are grateful for support from the NASA Astrobiology Institute. NR 38 TC 8 Z9 8 U1 1 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 1473-5504 J9 INT J ASTROBIOL JI Int. J. Astrobiol. PD JUL PY 2004 VL 3 IS 3 BP 265 EP 271 DI 10.1017/S1473550404001958 PG 7 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA V22OI UT WOS:000208284100009 ER PT J AU Beaubouef, T Ladner, R Petry, F AF Beaubouef, T Ladner, R Petry, F TI Rough set spatial data modeling for data mining SO INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS LA English DT Article; Proceedings Paper CT World Congress on Computational Intelligence (WCCI 2002) CY MAY, 2002 CL HONOLULU, HI AB Uncertainty management is necessary for real world applications, especially those used with data mining. The Region Connection Calculus (RCC) and egg-yolk methods have proven useful for the representation of vague regions in spatial data. Rough set theory has been shown to be an effective tool for data mining and for uncertainty management in databases. In this study we use a rough set foundation for expressing topological relationships previously defined for the RCC and egg-yolk methods and show that rough sets can improve on the representation of topological relationships and concepts defined with the other models, which leads to improved mining of spatial data. Finally, we provide an extension of spatial association rule generation that will be able to use rough set-modeled spatial data. (C) 2004 Wiley Periodicals, Inc. C1 SE Louisiana Univ, Dept Comp Sci, Hammond, LA 70402 USA. USN, Res Lab Mapping Charting & Geodesy, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. RP SE Louisiana Univ, Dept Comp Sci, Hammond, LA 70402 USA. EM tbeaubouef@selu.edu; rladner@nrlss.navy.mil; fpetry@nrlssc.navy.mil RI Petry, Frederick/F-9894-2010 NR 17 TC 22 Z9 27 U1 0 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0884-8173 EI 1098-111X J9 INT J INTELL SYST JI Int. J. Intell. Syst. PD JUL PY 2004 VL 19 IS 7 BP 567 EP 584 DI 10.1002/int.20019 PG 18 WC Computer Science, Artificial Intelligence SC Computer Science GA 831AC UT WOS:000222164300002 ER PT J AU Librescu, L Hasanyan, D Ambur, DR AF Librescu, L Hasanyan, D Ambur, DR TI Electromagnetically conducting elastic plates in a magnetic field: modeling and dynamic implications SO INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS LA English DT Article AB The basic field equations and boundary conditions necessary for the dynamic approach of electromagnetically conducting flat plates subjected to an external magnetic field are derived. Whereas the structural equations include the geometrical non-linearities of elastic isotropic plates, the electromagnetic equations are used in a linearized form that is obtained from their non-linear counterpart by applying the small disturbance concept. In this context, it was shown that the governing equations involve the bending-stretching coupling arising from both the geometrical non-linear approach of the problem and the inclusion of the Lorentz ponderomotive forces that are reduced to a 2-D plate counterpart. A number of special cases are considered, implications of the external magnetic field on non-linear/linear eigenfrequencies are highlighted, and pertinent conclusions are outlined. Published by Elsevier Ltd. C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. RP Librescu, L (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NR 16 TC 17 Z9 17 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7462 J9 INT J NONLINEAR MECH JI Int. J. Non-Linear Mech. PD JUL PY 2004 VL 39 IS 5 BP 723 EP 739 DI 10.1016/S0020-7462(03)00023-4 PG 17 WC Mechanics SC Mechanics GA 737TW UT WOS:000186248700003 ER PT J AU Zhou, G Baysal, O Kaye, J Habib, S Wang, C AF Zhou, G Baysal, O Kaye, J Habib, S Wang, C TI Concept design of future intelligent Earth observing satellites SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article AB This paper presents a concept design of an envisioned future intelligent Earth observing satellite (FIEOS) system. The proposed system is a space-based architecture for the dynamic and comprehensive on-board integration of Earth observing sensors, data processors and communication systems. The architecture and implementation strategies suggest a seamless integration of diverse components into a smart, adaptable and robust Earth observation satellite system. It is intended to enable simultaneous, global measurements and timely analyses of the Earth's environment for a variety of users. In particular, common users would directly access data in a manner similar to selecting a TV channel. We also discuss key technology problems, current technology development, amongst other things. It is concluded that (1) the proposed intelligent Earth observing satellite system is technically feasible; and (2) information technology and real-time information systems, for example multi-layer satellite networks connected with an organic system and on-board data processor capabilities, are crucial for implementation of the intelligent system. This revolutionary concept should dramatically impact on how Earth observing systems develop and conduct missions in the future. C1 Old Dominion Univ, Coll Engn & Technol, Norfolk, VA 23529 USA. NASA, Off Earth Sci, Div Res, Washington, DC 20546 USA. NASA, Goddard Space Flight Ctr, Earth Sci Directorate, Greenbelt, MD 20771 USA. Chinese Acad Sci, Inst Remote Sensing Applicat, Beijing 100101, Peoples R China. RP Zhou, G (reprint author), Old Dominion Univ, Coll Engn & Technol, Kaufman Hall,Rm 214, Norfolk, VA 23529 USA. EM gzhou@odu.edu NR 32 TC 6 Z9 7 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD JUL PY 2004 VL 25 IS 14 BP 2667 EP 2685 DI 10.1080/0143116031000101558 PG 19 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 828UU UT WOS:000221999600002 ER PT J AU Tin, P de Groh, HC AF Tin, P de Groh, HC TI Surface tension and viscosity of succinonitrile acetone alloys using surface light scattering spectrometer SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 15th Symposium on Thermophysical Properties CY JUN 22-27, 2003 CL Univ Colorado, BOULDER, CO SP Amer Soc Mech Engineers, Heat Transfer Div, Natl Inst Stand & Technol, Phys & Chem Properties Div HO Univ Colorado DE interfacial surface energy; metal analog; succinonitrile; surface light scattering spectrometer; surface tension; viscosity ID MICROGRAVITY SOLIDIFICATION; THERMOCAPILLARY CONVECTION; LIQUID SURFACE; SEGREGATION; GROWTH AB Using a surface light scattering spectroscopic technique, the surface tension and viscosity of pure succinonitrile (SCN) and SCN-acetone alloys at 0.86, 1.69, and 2.25 mol% have been determined. The surface light scattering technique, and the procedures used for making the alloys and measuring their concentrations, are presented. Analysis indicates our interfacial surface tension and viscosity measurements have an uncertainty of +/-2% and +/-10%, respectively. The surface tension and viscosity were measured at various temperatures yielding relations among surface tension, viscosity, temperature, and concentration in SCN-acetone alloys. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. RP Tin, P (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. EM padetha.tin@grc.nasa.gov NR 34 TC 4 Z9 4 U1 1 U2 4 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 2004 VL 25 IS 4 BP 1143 EP 1153 DI 10.1023/B:IJOT.0000038506.26409.7f PG 11 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 847NM UT WOS:000223402200013 ER PT J AU Hyers, RW Bradshaw, RC Rogers, JR Rathz, TJ Lee, GW Gangopadhyay, AK Kelton, KF AF Hyers, RW Bradshaw, RC Rogers, JR Rathz, TJ Lee, GW Gangopadhyay, AK Kelton, KF TI Surface tension and viscosity of quasicrystal-forming Ti-Zr-Ni alloys SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 15th Symposium on Thermophysical Properties CY JUN 22-27, 2003 CL Univ Colorado, BOULDER, CO SP Amer Soc Mech Engineers, Heat Transfer Div, Natl Inst Stand & Technol, Phys & Chem Properties Div HO Univ Colorado DE electrostatic levitation; quasicrystal; surface tension; Ti-Zr-Ni alloys; viscosity ID OSCILLATIONS; GLASSES AB Recent X-ray scattering measurements show that icosahedral short-range order in Ti-Zr-Ni alloys is responsible for a change in phase selection from the stable C14 Laves phase to the quasicrystalline icosahedral phase, and that icosahedral short-range order increases at deeper undercoolings. This change in short-range order should be reflected in changes in the thermophysical properties of the melt. The surface tension and viscosity of quasicrystal-forming Ti-Zr-Ni alloys were measured over a range of temperature, including both stable and undercooled liquids, by an electrostatic levitation (ESL) technique. ESL is a containerless technique which allows processing of samples without contact, greatly reducing contamination and increasing access to the metastable undercooled liquid. The measured viscosity is typical of glass-forming alloys of similar composition to the quasicrystal-forming alloys studied here; however, the surface tension shows an anomaly at deep undercoolings. C1 Univ Massachusetts, Dept Mech & Ind Engn, Amherst, MA 01003 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Ctr Automat & Robot, Huntsville, AL 35899 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. RP Hyers, RW (reprint author), Univ Massachusetts, Dept Mech & Ind Engn, Amherst, MA 01003 USA. EM hyers@ecs.umass.edu RI Hyers, Robert/G-3755-2010 NR 18 TC 19 Z9 19 U1 4 U2 10 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JUL PY 2004 VL 25 IS 4 BP 1155 EP 1162 DI 10.1023/B:IJOT.0000038507.99417.5b PG 8 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 847NM UT WOS:000223402200014 ER PT J AU Bansal, NP Wheeler, DR Chen, YL AF Bansal, NP Wheeler, DR Chen, YL TI Mechanical, chemical and microstructural characterization of monazite-coated Hi-Nicalon and Sylramic fibers SO JOURNAL OF ADVANCED MATERIALS LA English DT Article ID CELSIAN-MATRIX COMPOSITES; TENSILE-STRENGTH; HIGH-TEMPERATURES; WEIBULL MODULUS; LOW-OXYGEN; COATINGS; BEHAVIOR AB Tensile strengths of as-received Hi-Nicalon and Sylramic fibers and those having Monazite surface coatings, deposited by atmospheric pressure chemical vapor deposition, were measured at room temperature and the Weibull statistical parameters determined. The average tensile strengths of uncoated Hi-Nicalon and Sylramic fibers were 3.2 +/- 0.7 GPa and 2.8 +/- 0.5 GPa with a Weibull modulus of 5.4 and 5.5, respectively. The monazite-coated Hi-Nicalon and Sylramic fibers showed strength loss of similar to10 % and 15 %, respectively, compared with the as-received fibers. The elemental compositions of the fibers and the coatings were analyzed using scanning Auger microprobe and energy dispersive x-ray spectroscopy. The LaPO4 coating on Hi-Nicalon fibers was approximately stoichiometric and about 50 nm thick. The coating on the Sylramic fibers extended to a depth of about 100 - 150 nm. The coating may have been stoichiometric LaPO4 in the first 30 - 40 nm of the layer. However the surface roughness of Sylramic fiber made this profile somewhat difficult to interpret. Microstructural analyses of the fibers and the coatings were done by scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction. Hi-Nicalon fiber consists of fine beta-SiC nanocrystals ranging in size from 1 - 30 nm embedded in an amorphous matrix. Sylramic is a polycrystalline stoichiometric silicon carbide fiber consisting of submicron beta-SiC crystallites ranging from 100 - 300 nm. Small amount of TiB2 nanocrystallites (similar to50 nm) are also present. The LaPO4 coating on Hi-Nicalon fibers consisted of a chain of peanut shape particles having monazite-(La) structure. The coating on Sylramic fibers consisted of two layers. The inner layer was a chain of peanut shape particles having monazite-(La) structure. The outer layer was comprised of much smaller particles with a microcrystalline structure. C1 NASA, Glenn Res Ctr, Cleveland, OH USA. NASA, Glenn Res Ctr Grp, QSS Inc, Cleveland, OH USA. RP Bansal, NP (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. EM n.p.bansal@grc.nasa.gov NR 23 TC 1 Z9 1 U1 1 U2 5 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 1070-9789 J9 J ADV MATER-COVINA JI J. Adv. Mater. PD JUL PY 2004 VL 36 IS 3 BP 3 EP 13 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA 829VI UT WOS:000222078000002 ER PT J AU Goldberg, RK Roberts, GD AF Goldberg, RK Roberts, GD TI Analytical studies of the high strain rate tensile response of a polymer matrix composite SO JOURNAL OF ADVANCED MATERIALS LA English DT Article AB A research program is in progress to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to impact loads. Previously, strain rate dependent inelastic constitutive equations developed to model the polymer matrix were incorporated into a mechanics of materials based micromechanics method In the current work, the micromechanics method is revised such that the composite unit cell is divided into a number of slices. Micromechanics equations are then developed for each slice, with laminate theory applied to determine the elastic properties, effective stresses and effective inelastic strains for the unit cell. Verification studies are conducted using a representative polymer matrix composite system with a nonlinear strain rate dependent deformation response. Computed stress-strain curves compare well to experimentally obtained results for several laminate orientations over strain rates ranging from quasi-static to several hundred per second. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Ohio State Univ, Columbus, OH 43210 USA. RP NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM Robert.K.Goldberg@grc.nasa.gov NR 22 TC 6 Z9 6 U1 1 U2 2 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 1070-9789 J9 J ADV MATER-COVINA JI J. Adv. Mater. PD JUL PY 2004 VL 36 IS 3 BP 14 EP 24 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA 829VI UT WOS:000222078000003 ER PT J AU Theodore, CR Tischler, MB Colbourne, JD AF Theodore, CR Tischler, MB Colbourne, JD TI Rapid frequency-domain modeling methods for unmanned aerial vehicle flight control applications SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA Atmospheric Flight Mechanics Conference CY AUG, 2003 CL AUSTIN, TEXAS SP Amer Inst Aeronaut & Astronaut ID SYSTEM-IDENTIFICATION; ROTORCRAFT AB Modeling of the flight dynamics of unmanned aerial vehicles (UAVs) poses unique challenges that are not present with manned aircraft. The use of analytical modeling methods based on first principles is often difficult for UAVs because of short design cycles, reduced development costs, and many unconventional designs. Also, without the need to carry a pilot, UAVs are often much smaller and lighter than manned aircraft. The lower weights and inertias result in higher natural frequencies and quicker vehicle responses requiring high bandwidth dynamics models. Frequency-domain system identification is especially well suited to the modeling of UAVs. With the availability of flight hardware early in many UAV programs, dynamic response models of the vehicle can be identified and validated rapidly with flight data. The system identification method also allows for rapid updating of vehicle response models as physical changes are made to the vehicle configuration. The use of frequency-domain system identification in the development and operation of a number of UAV programs is discussed. The example aircraft programs include Northrop Grumman's Fire Scout vertical takeoff unmanned air vehicle demonstrator based on the Schweizer 300 helicopter; the broad-area unmanned responsive resupply operations UAV based on Kaman's twin-rotor K-MAX helicopter; AeroVironment's Pathfinder solar-powered stratospheric research aircraft; Yamaha's R-50 small-scale helicopter; and the class of small-scale ducted fan vehicles developed separately by Allied Aerospace (formerly Micro Craft) and Honeywell. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Theodore, CR (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 14 TC 17 Z9 24 U1 1 U2 10 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 2004 VL 41 IS 4 BP 735 EP 743 DI 10.2514/1.4671 PG 9 WC Engineering, Aerospace SC Engineering GA 844RZ UT WOS:000223178700007 ER PT J AU Chandrasekhara, MS Martin, PB Tung, C AF Chandrasekhara, MS Martin, PB Tung, C TI Compressible dynamic stall control using a variable droop leading edge airfoil SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA 41st Aerospace Sciences Meeting CY JAN 06-09, 2003 CL RENO, NV SP Amer Inst Aeronaut & Astronaut AB The control of compressible dynamic stall using a variable droop leading edge airfoil is described. The leading 25% of a VR-12 airfoil is drooped as it executes sinusoidal pitch oscillations such that the leading portion of the airfoil is always at a low effective incidence to the flow. Airfoil performance data determined for freestream Mach numbers ranging from 0.2 to 0.4, at reduced frequencies from 0 to 0.1, and using unsteady pressure transducer measurements, show that droop reduces the tendency of the airfoil to enter the dynamic stall state. Even when it does, the strength of the dynamic stall vortex is significantly reduced, which is reflected in the 40 to 50% smaller negative peak pitching-moment values, with positive damping of the airfoil. Also, the airfoil drag when the droop is dynamically varied is reduced by up to 75% relative to a nondrooped airfoil, making a strong case for the use of this concept for dynamic stall control. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Chandrasekhara, MS (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 7 TC 17 Z9 19 U1 0 U2 1 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 2004 VL 41 IS 4 BP 862 EP 869 DI 10.2514/1.472 PG 8 WC Engineering, Aerospace SC Engineering GA 844RZ UT WOS:000223178700020 ER PT J AU Murman, SM Aftosmis, MJ Berger, MJ AF Murman, SM Aftosmis, MJ Berger, MJ TI Simulations of store separation from an F/A-18 with a Cartesian method SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA 41st Aerospace Sciences Meeting CY JAN 06-09, 2003 CL RENO, NV SP Amer Inst Aeronaut & Astronaut AB Coupled computational fluid dynamics with six-degree-of-freedom trajectory predictions using an automated Cartesian method are demonstrated by simulating a GBU-31/Joint Direct Attack Munition store separating from an F/A-18C aircraft. Numerical simulations are performed at two Mach numbers near the sonic speed and compared with flight-test telemetry and photographic-derived data. For both Mach numbers, simulation results using a sequential-static series of flow solutions are contrasted with results using a time-dependent approach. Both numerical approaches show good agreement with the flight-test data through the first 0.25 s of the trajectory. At later times the sequential-static and time-dependent methods diverge, after the store produces peak angular rates; however, both remain close to the flight-test trajectory. C1 ELORET, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Courant Inst New York, New York, NY 10012 USA. RP Murman, SM (reprint author), ELORET, Moffett Field, CA 94035 USA. EM smurman@nas.nasa.gov NR 22 TC 7 Z9 7 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JUL-AUG PY 2004 VL 41 IS 4 BP 870 EP 878 DI 10.2514/1.473 PG 9 WC Engineering, Aerospace SC Engineering GA 844RZ UT WOS:000223178700021 ER PT J AU Librescu, L Marzocca, P Silva, WA AF Librescu, L Marzocca, P Silva, WA TI Linear/nonlinear supersonic panel flutter in a high-temperature field SO JOURNAL OF AIRCRAFT LA English DT Article ID NONLINEAR FLUTTER; CURVED PLATES; PISTON THEORY; BOUNDARY AB An analysis of the flutter and postflutter behavior of infinitely long flat panels in a supersonic/hypersonic flowfield exposed to a high-temperature field is presented. In the approach to the problem, the thermal degradation of thermoelastic characteristics of the material is considered. A third-order piston theory aerodynamic model in conjunction with the von Karman nonlinear plate theory is used to obtain the pertinent aerothermoelastic governing equations. The implications of temperature, thermal degradation, and of structural and aerodynamic nonlinearities on the character of the flutter instability boundary are analyzed. As a by product, the implications of the temperature on the linearized flutter instability of the system are discussed. The behavior of the structural system in the vicinity of the flutter boundary is studied via the use of an encompassing methodology based on the Lyapunov First Quantity. Numerical illustrations, supplying pertinent information on the implications of the temperature field and of the thermal degradation are presented, and pertinent conclusions are outlined. C1 Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Clarkson Univ, Potsdam, NY 13699 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Librescu, L (reprint author), Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. EM librescu@vt.edu; piermz@vt.edu; w.a.silva@larc.nasa.gov NR 23 TC 22 Z9 25 U1 2 U2 8 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 2004 VL 41 IS 4 BP 918 EP 924 DI 10.2514/1.679 PG 7 WC Engineering, Aerospace SC Engineering GA 844RZ UT WOS:000223178700026 ER PT J AU Mukhopadhyay, V Sobieszczanski-Sobieski, J Kosaka, I Quinn, G Vanderplaats, GN AF Mukhopadhyay, V Sobieszczanski-Sobieski, J Kosaka, I Quinn, G Vanderplaats, GN TI Analysis, design, and optimization of noncylindrical fuselage for blended-wing-body vehicle SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA/ISSMO 9th Symposium on Multidisciplinary Analysis and Optimization CY SEP 04-06, 2002 CL ATLANTA, GA SP Amer Inst Aeronaut & Astronaut, ISSMO AB A study toward finding an efficient noncylindrical fuselage configuration for a conceptual blended-wing-body flight vehicle is presented. A simplified two-dimensional beam-column analysis and optimization was used to demonstrate the problem of containing cabin pressure in such flight vehicles. Then a set of detailed finite element models of deep sandwich panel and ribbed shell construction concepts were analyzed and optimized. Generally these constructions with high bending stiffness but without curvature were found to be structurally efficient to a certain extent to withstand internal pressure and resultant compressive loads simultaneously. To attain additional structural efficiency, a set of multibubble fuselage configurations was developed for balancing internal cabin pressure load efficiently, through membrane stress in inner-stiffened shell and intercabin walls. An outer-ribbed shell was designed to prevent buckling due to external resultant compressive loads. Initial results from finite element analysis of a representative fuselage segment, using this stress separation concept, appear to be promising. This concept has some additional advantages. Distortion of aerodynamic surface due to cabin pressure is minimal. Availability of duct space above and below the main fuselage can be used for direct ventilation; these also provide structural redundancy in the event of a pressure leak as well as for improved crashworthiness. These concepts should be developed further to exploit their inherent structural efficiency. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Vanderplaats R&D Inc, Colorado Springs, CO 80906 USA. RP Mukhopadhyay, V (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM v.mukhopadhyay-1@nasa.gov; j.sobieski@larc.nasa.gov; ikosaka@vrand.com; quinng@vrand.com; vanderplaats@vrand.com NR 13 TC 5 Z9 5 U1 0 U2 7 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 2004 VL 41 IS 4 BP 925 EP 930 DI 10.2514/1.417 PG 6 WC Engineering, Aerospace SC Engineering GA 844RZ UT WOS:000223178700027 ER PT J AU Karkehabadi, R AF Karkehabadi, R TI Thick wings in steady and unsteady flows SO JOURNAL OF AIRCRAFT LA English DT Article C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Karkehabadi, R (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 6 TC 2 Z9 2 U1 1 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 2004 VL 41 IS 4 BP 964 EP 967 DI 10.2514/1.4589 PG 4 WC Engineering, Aerospace SC Engineering GA 844RZ UT WOS:000223178700037 ER PT J AU Dobson, CC Hrbud, I AF Dobson, CC Hrbud, I TI Electron density and two-channel neutron emission measurements in steady-state spherical inertial-electrostatically confined plasmas, with review of the one-dimensional kinetic model SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CONVERGENT ION FOCUS; POTENTIAL WELL; FUSION; DEVICE; STABILITY; GEOMETRY AB Electron density measurements have been made in steady-state plasmas in a spherical inertial electrostatic confinement (IEC) discharge using microwave interferometry. Plasma cores interior to two cathodes, having diameters of 15 and 23 cm, respectively, were probed over a transverse range of 10 cm with a spatial resolution of about 1.4 cm for buffer gas pressures from 0.2 to 6 Pa in argon and deuterium. The transverse profiles are generally flat, in some cases with eccentric symmetric minima, and give mean densities of from approximate to0.4 to 7x10(10) cm(-3), the density generally increasing with the neutral gas pressure. Numerical solutions of the one-dimensional Poisson equation for IEC plasmas are reviewed and energy distribution functions are identified which give flat transverse profiles. These functions are used with the plasma approximation to obtain solutions which also give densities consistent with the measurements, and a double potential well solution is obtained which has minima qualitatively similar to those observed. Explicit consideration is given to the compatibility of the solutions interior and exterior to the cathode, and to grid transparency. Deuterium fusion neutron emission rates were also measured and found to be isotropic, to within the measurement error, over two simultaneous directions. Anisotropy was observed in residual emissions during operation with nonfusing hydrogen-1. The deuterium rates are consistent with predictions from the model. (C) 2004 American Institute of Physics. C1 NASA, George C Marshall Space Flight Ctr, Prop Res Ctr, Huntsville, AL 35812 USA. Purdue Univ, Sch Aeronaut & Astronaut Engn, W Lafayette, IN 47906 USA. RP Dobson, CC (reprint author), NASA, George C Marshall Space Flight Ctr, Prop Res Ctr, Huntsville, AL 35812 USA. EM christopher.c.dobson@nasa.gov NR 46 TC 6 Z9 6 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 2004 VL 96 IS 1 BP 94 EP 108 DI 10.1063/1.1755854 PG 15 WC Physics, Applied SC Physics GA 830AF UT WOS:000222093300014 ER PT J AU Shackelford, LC LeBlanc, AD Driscoll, TB Evans, HJ Rianon, NJ Smith, SM Spector, E Feeback, DL Lai, D AF Shackelford, LC LeBlanc, AD Driscoll, TB Evans, HJ Rianon, NJ Smith, SM Spector, E Feeback, DL Lai, D TI Resistance exercise as a countermeasure to disuse-induced bone loss SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE microgravity; bed rest; bone resorption; bone formation; strength training ID BED-REST; CALCIUM-ABSORPTION; MINERAL DENSITY; BIOCHEMICAL MARKERS; BODY SCANS; TURNOVER; STRENGTH; MASS; WEIGHTLESSNESS; SPACEFLIGHT AB During spaceflight, skeletal unloading results in loss of bone mineral density (BMD). This occurs primarily in the spine and lower body regions. This loss of skeletal mass could prove hazardous to astronauts on flights of long duration. In this study, intense resistance exercise was use to test whether a training regimen would prevent the loss of BMD that companies disuse. Nine subjects (5 men, 4 women) participated in a supine maximal resistance exercise training program during 17 wk of horizontal bed rest. These subjects were compared with 18 control subjects (13 men, 5 women) who followed the same bed rest protocol without exercise. Determination of treatment effect was based on measures of BMD, bone metabolism markers, and calcium balance obtained before, during, and after bed rest. Exercisers and controls had significantly (P < 0.05) different means, represented by the respective following percent changes: lumbar spine BMD, +3% vs. -1%; total hip BMD, +1% vs. -3%; calcaneus BMD, +1% vs. -9%; pelvis BMD, -0.5% vs. -3%; total body BNID, 0% vs. -1%; bone-specific alkaline phosphatase, +64% vs. 0%; alkaline phosphatase, +31% vs. +5%; osteocalcin, +43% vs. +10%; 1,25 dihydroxyvitamin D, +12% vs. -15%; parathyroid hormone intact molecule, +18% vs. -25%; and serum and ionized calcium, -1% vs. +1%. The difference in net calcium balance was also significant (+21 mg/day vs. -199 mg/day, exercise vs. control). The gastrocnemius and soleus muscle volumes decreased significantly in the exercise group, but the loss was significantly less than observed in the control group. The results indicate that resistance exercise had a positive treatment effect and thus might be useful as a countermeasure to prevent the deleterious skeletal changes associated with long-duration spaceflight. C1 Baylor Coll Med, Dept Med, Houston, TX 77030 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Space Res Assoc, Div Space Life Sci, Houston, TX 77058 USA. Wyle Labs Life Sci Syst & Serv, Houston, TX 77058 USA. Univ Texas, Sch Publ Hlth, Houston, TX 77030 USA. RP LeBlanc, AD (reprint author), Baylor Coll Med, Dept Med, 6550 Fannin St,Ste 1260, Houston, TX 77030 USA. FU NCRR NIH HHS [M01 RR-00188] NR 36 TC 167 Z9 175 U1 3 U2 11 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD JUL PY 2004 VL 97 IS 1 BP 119 EP 129 DI 10.1152/japplphysiol.00741.2003 PG 11 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 833BF UT WOS:000222310700016 PM 15220316 ER PT J AU White, WB Gloersen, P Simmonds, I AF White, WB Gloersen, P Simmonds, I TI Tropospheric response in the Antarctic circumpolar wave along the sea ice edge around Antarctica SO JOURNAL OF CLIMATE LA English DT Article ID NINO-SOUTHERN OSCILLATION; TELECONNECTIONS; TEMPERATURE; OCEAN; REANALYSIS; PACIFIC AB The Antarctic circumpolar wave (ACW) signal of a 3.7-yr period occurs along the sea ice edge forming around Antarctic each fall - winter - spring from 1982 to 2001. It was larger during the first decade than the second and has retracted sea ice extent (SIE) anomalies coinciding with warmer sea surface temperature, greater upward latent heat flux, and higher precipitation, driving deep convection in the troposphere associated with low-level convergence and upper-level divergence. Lower sea level pressure is displaced; 908 of phase to the west of retracted SIE anomalies, coinciding with increased extratropical cyclone density and intensity. The authors diagnose tropospheric thermal and potential vorticity budgets of this ACW signal using NCEP-NCAR reanalysis datasets, which show retracted SIE anomalies driving upper-level diabatic heating and low-level cooling, the former ( latter) balanced mainly by vertical heat advection (poleward heat advection). This explains the anomalous poleward surface winds and deep convection observed over retracted SIE anomalies in this ACW signal. Thus, the vertical gradient of diabatic heating is balanced mainly by horizontal vortex tube advection at the low level and horizontal absolute vorticity advection at the upper level, together yielding the anomalous equivalently barotropic poleward wind response to the retracted SIE anomaly. Anomalous SIE-induced deep convection at the sea ice edge drives anomalous zonal (Walker-like) cells that teleconnect opposite phases in the ACW signal. It also drives anomalous Ferrell cells that teleconnect the ACW signal along the sea ice edge to that along the Subtropical Front near 35degreesS. C1 Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. NASA, Oceans & Ice Branch, Lab Hydrosphere Sci, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Melbourne, Sch Earth Sci, Parkville, Vic 3052, Australia. RP White, WB (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. EM wbwhite@ucsd.edu OI Simmonds, Ian/0000-0002-4479-3255 NR 29 TC 18 Z9 19 U1 2 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JUL PY 2004 VL 17 IS 14 BP 2765 EP 2779 DI 10.1175/1520-0442(2004)017<2765:TRITAC>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 839NF UT WOS:000222791100004 ER PT J AU Cervini-Silva, J AF Cervini-Silva, J TI Alteration of the surface charge of aluminum goethites by a sulfonic acid buffer SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE aluminum goethite; isomorphic substitution; 2-[N-morpholino]ethanesulfonic acid; charge reversal ID AL-SUBSTITUTED GOETHITE; DISSOLUTION AB Four samples of synthetic low-substitution Al-goethites (mol% Al < 10) were incubated with 10 mM NaClO4 and 5 mM MES buffer (MES buffer (2-[N-morpholino]ethanesulfonic acid) at pH 5. It was found that MES buffer, although commonly used to control pH, profoundly affected the results of our electrophoretic mobility measurements. The presence of MES buffer caused a large decrease in EM values for unsubstituted goethite, from 5.7 +/- 0.7 to 1.8 +/- 0.4 x 10(-8) m(2) v(-1) s(-1), while increases in Al substitution in goethite led to a progressive increase in EM values. The charge reversal following addition of MES buffer to suspension containing Al-goethites was explained by specific sorption that, at pH 5, is thought to occur via cation surface complexation because of (i) sulfonate induced-dipole or (ii) N and O lone-pair dipole-dipole interactions with structural Fe. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Calif Berkeley, Dept Earth & Planetary Sci, Ctr Integrat Planetary Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, NASA, Astrobiol Inst, Berkeley, CA 94720 USA. RP Cervini-Silva, J (reprint author), Univ Calif Berkeley, Dept Earth & Planetary Sci, Ctr Integrat Planetary Sci, Hilgard Hall 3110, Berkeley, CA 94720 USA. EM javiera@cps.berkeley.edu NR 10 TC 4 Z9 4 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 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD JUL 1 PY 2004 VL 275 IS 1 BP 79 EP 81 DI 10.1016/j.jcis.2004.01.017 PG 3 WC Chemistry, Physical SC Chemistry GA 824QA UT WOS:000221699900011 PM 15158383 ER PT J AU Branets, VN Clubb, J Knutov, AS Mikrin, EA Chertok, BE Sherrill, J AF Branets, VN Clubb, J Knutov, AS Mikrin, EA Chertok, BE Sherrill, J TI Development of computer systems supported by artificial intelligence elements applied to spacecraft control systems SO JOURNAL OF COMPUTER AND SYSTEMS SCIENCES INTERNATIONAL LA English DT Article AB A survey of the main stages of the development of computer aids applicable to control systems of manned spacecrafts (both Russian and American) is presented. The peculiarities and technical specifications of onboard computer systems are given. The most important problems arising in control systems of widely known spacecrafts are listed. Also, the main stages of the methodology and technology of software development are outlined. The spacecraft control systems developed are compared with current intelligent systems. C1 RSC Energiya, Moscow, Russia. NASA, Houston, TX USA. RP Branets, VN (reprint author), RSC Energiya, Moscow, Russia. NR 0 TC 0 Z9 0 U1 0 U2 2 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA SN 1064-2307 J9 J COMPUT SYS SC INT+ JI J. Comput. Syst. Sci. Int. PD JUL-AUG PY 2004 VL 43 IS 4 BP 633 EP 636 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Theory & Methods SC Computer Science GA 849GJ UT WOS:000223526400016 ER PT J AU Palosz, W AF Palosz, W TI Residual gas in closed systems - I: development of gas in fused silica ampoules SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE degassing; residual gas; silica glass ID VITREOUS SILICA; GLASS AMPOULES; HYDROGEN; GROWTH; DIFFUSION; QUARTZ; WATER AB The amounts and composition of residual gases formed in empty sealed silica glass ampoules were investigated. The effect of the silica brand, outgassing and annealing conditions, system geometry, and presence of graphite were determined and discussed. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, BAE Syst, Huntsville, AL 35812 USA. RP Palosz, W (reprint author), NASA, George C Marshall Space Flight Ctr, BAE Syst, SD46,AS, Huntsville, AL 35812 USA. EM witold.palosz@msfc.nasa.gov NR 25 TC 10 Z9 10 U1 0 U2 3 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 JUL 1 PY 2004 VL 267 IS 3-4 BP 475 EP 483 DI 10.1016/j.jcrysgro.2004.04.046 PG 9 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 835LJ UT WOS:000222484400012 ER PT J AU Palosz, W AF Palosz, W TI Residual gas in closed systems - II: generation and reduction of the gas from the source materials SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE impurities; purification; residual gas ID PHYSICAL VAPOR TRANSPORT; TELLURIDE; AMPOULES AB The amounts and compositions of residual gases formed in scaled ampoules loaded with different sources (elements and 11 VI and IV-VI compounds) were investigated. A given source was subjected to a series of heat treatments, with intermediate measurements and removal of the gas accumulated in the system. The results of these experiments are discussed in terms of the underlying thermochemical and kinetic phenomena and practical limitations to reducing the amount of residual gases in sealed ampoules. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, BAE Syst, Huntsville, AL 35812 USA. RP Palosz, W (reprint author), NASA, George C Marshall Space Flight Ctr, BAE Syst, AS,SD46, Huntsville, AL 35812 USA. EM witold.palosz@msfc.nasa.gov NR 12 TC 4 Z9 4 U1 1 U2 1 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 JUL 1 PY 2004 VL 267 IS 3-4 BP 484 EP 497 DI 10.1016/j.jcrysgro.2004.04.047 PG 14 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 835LJ UT WOS:000222484400013 ER PT J AU Calle, CI Mantovani, JG Buhler, CR Groop, EE Buehler, MG Nowicki, AW AF Calle, CI Mantovani, JG Buhler, CR Groop, EE Buehler, MG Nowicki, AW TI Embedded electrostatic sensors for Mars exploration missions SO JOURNAL OF ELECTROSTATICS LA English DT Article; Proceedings Paper CT Joint Meeting of the Electrostatistics-Society-of-America/IEEE-Industry-Applications-Society- Electrostatic-Processes-Committee CY JUN 24-27, 2003 CL Little Rock, AK SP Electostatist Soc Amer, IEEE, Ind Applicat Soc Electrstat Processes Comm DE electrostatic sensors; charged dust; charge measurement; electrostatic properties of Mars ID DUST; PATHFINDER; SOIL AB Instrumentation on NASA's Mars landers have shown that winds airlift dust-size grains of iron-rich clays which are the weathering products of the abundant iron- and magnesium-rich volcanic rocks commonly found on the Martian surface. Experiments conducted at Arizona State University and at NASA Ames Research Center, as well as similar experiments in our laboratory, suggest that when these dust particles are transported by the wind, they collide and develop electrostatic charges, It has been suggested that sand-size particles on the surface could be aggregates of dust particles bound to each other by electrostatic forces. This paper describes the design of electrostatic sensors embedded in different materials commonly used in planetary spacecraft and their possible use in future exploration missions to the planet. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Electrostat & Surface Phys Lab, Kennedy Space Ctr, FL 32899 USA. Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. ASRC Aerosp, Kennedy Space Ctr, FL 32899 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Calle, CI (reprint author), NASA, Electrostat & Surface Phys Lab, Kennedy Space Ctr, FL 32899 USA. EM carlos.i.calle@nasa.gov NR 24 TC 12 Z9 13 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3886 J9 J ELECTROSTAT JI J. Electrost. PD JUL PY 2004 VL 61 IS 3-4 BP 245 EP 257 DI 10.1016/j.elstat.2004.03.001 PG 13 WC Engineering, Electrical & Electronic SC Engineering GA 830CZ UT WOS:000222100500008 ER PT J AU Hogue, MD Buhler, CR Calle, CI Matsuyama, T Luo, W Groop, EE AF Hogue, MD Buhler, CR Calle, CI Matsuyama, T Luo, W Groop, EE TI Insulator-insulator contact charging and its relationship to atmospheric pressure SO JOURNAL OF ELECTROSTATICS LA English DT Article; Proceedings Paper CT Joint Meeting of the Electrostatistics-Society-of-America/IEEE-Industry-Applications-Society- Electrostatic-Processes-Committee CY JUN 24-27, 2003 CL Little Rock, AK SP Electostatist Soc Amer, IEEE, Ind Applicat Soc Electrstat Processes Comm DE contact charging; insulator; triboelectrification; pressure ID ELECTRIFICATION; POLYMERS AB Metal-metal and metal-insulator contact charging are well-known phenomena with good theoretical understanding. However, insulator-insulator charging is not as well understood. Surface ion exchange is suspected of being the mechanism of insulator-insulator triboelectric charging. Experiments have shown that the amount of charge exchange is highly dependent on the atmospheric pressure of the gas. We present a two-phase model based on an ideal gas of singly-charged ions in equilibrium with a submonolayer adsorbed film. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Electrostat & Mat Phys Lab, Kennedy Space Ctr, FL 32899 USA. NASA, Kennedy Space Ctr, Electostat & Mat Phys Lab, Merritt Isl, FL 32953 USA. Soka Univ, Fac Engn, Tokyo 1928577, Japan. Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. RP Hogue, MD (reprint author), NASA, Electrostat & Mat Phys Lab, Mailcode YA-C2-T, Kennedy Space Ctr, FL 32899 USA. EM michael.d.hogue@nasa.gov RI Matsuyama, Tatsushi/A-3536-2010 NR 27 TC 31 Z9 31 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3886 J9 J ELECTROSTAT JI J. Electrost. PD JUL PY 2004 VL 61 IS 3-4 BP 259 EP 268 DI 10.1016/j.elstat.2004.03.002 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA 830CZ UT WOS:000222100500009 ER PT J AU Silva, WA Bartels, RE AF Silva, WA Bartels, RE TI Development of reduced-order models for aeroelastic analysis and flutter prediction using the CFL3Dv6.0 code SO JOURNAL OF FLUIDS AND STRUCTURES LA English DT Article ID IDENTIFICATION AB A reduced-order model (ROM) is developed for aeroelastic analysis using the CFL3D version 6.0 computational fluid dynamics (CFD) code, recently developed at the NASA Langley Research Center. This latest version of the flow solver includes a deforming mesh capability, a modal structural definition for nonlinear aeroelastic analyses, and a parallelization capability that provides a significant increase in computational efficiency. Flutter results for the AGARD 445.6 Wing computed using CFL3D v6.0 are presented, including discussion of associated computational costs. Modal impulse responses of the unsteady aerodynamic system are then computed using the CFL3Dv6 code and transformed into state-space form. Important numerical issues associated with the computation of the impulse responses are presented. The unsteady aerodynamic state-space ROM is then combined with a state-space model of the structure to create an aeroelastic simulation using the MATLAB/SIMULINK environment. The MATLAB/ SIMULINK ROM is used to rapidly compute aeroelastic transients including flutter. The ROM shows excellent agreement with the aeroelastic analyses computed using the CFL3Dv6.0 code directly. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Aeroelast Branch, Hampton, VA 23681 USA. RP Silva, WA (reprint author), NASA, Langley Res Ctr, Aeroelast Branch, Hampton, VA 23681 USA. EM walter.a.silva@nasa.gov NR 36 TC 54 Z9 59 U1 0 U2 8 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0889-9746 J9 J FLUID STRUCT JI J. Fluids Struct. PD JUL PY 2004 VL 19 IS 6 BP 729 EP 745 DI 10.1016/j.jfluidstructs.2004.03.004 PG 17 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 841CQ UT WOS:000222907300001 ER PT J AU Kondo, Y Morino, Y Takegawa, N Koike, M Kita, K Miyazaki, Y Sachse, GW Vay, SA Avery, MA Flocke, F Weinheimer, AJ Eisele, FL Zondlo, MA Weber, RJ Singh, HB Chen, G Crawford, J Blake, DR Fuelberg, HE Clarke, AD Talbot, RW Sandholm, ST Browell, EV Streets, DG Liley, B AF Kondo, Y Morino, Y Takegawa, N Koike, M Kita, K Miyazaki, Y Sachse, GW Vay, SA Avery, MA Flocke, F Weinheimer, AJ Eisele, FL Zondlo, MA Weber, RJ Singh, HB Chen, G Crawford, J Blake, DR Fuelberg, HE Clarke, AD Talbot, RW Sandholm, ST Browell, EV Streets, DG Liley, B TI Impacts of biomass burning in Southeast Asia on ozone and reactive nitrogen over the western Pacific in spring SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE biomass burning; ozone; NOy ID TROPICAL TROPOSPHERIC OZONE; BOUNDARY-LAYER EXPERIMENT; CARBON-MONOXIDE; PEM-WEST; CONTINENTAL OUTFLOW; CHEMICAL EVOLUTION; NORTHERN AUSTRALIA; ATMOSPHERIC CHEMISTRY; TRANSPORT PATHWAYS; FIELD EXPERIMENT AB [1] Aircraft measurements of ozone (O-3) and its precursors ( reactive nitrogen, CO, nonmethane hydrocarbons) were made over the western Pacific during the Transport and Chemical Evolution Over the Pacific (TRACE-P) campaign, which was conducted during February - April 2001. Biomass burning activity was high over Southeast Asia ( SEA) during this period ( dry season), and convective activity over SEA frequently transported air from the boundary layer to the free troposphere, followed by eastward transport to the sampling region over the western Pacific south of 30 degreesN. This data set allows for systematic investigations of the chemical and physical processes in the outflow from SEA. Methyl chloride (CH3Cl) and CO are chosen as primary and secondary tracers, respectively, to gauge the degree of the impact of emissions of trace species from biomass burning. Biomass burning is found to be a major source of reactive nitrogen (NOx, PAN, HNO3, and nitrate) and O-3 in this region from correlations of these species with the tracers. Changes in the abundance of reactive nitrogen during upward transport are quantified from the altitude change of the slopes of the correlations of these species with CO. NOx decreased with altitude due to its oxidation to HNO3. On the other hand, PAN was conserved during transport from the lower to the middle troposphere, consistent with its low water solubility and chemical stability at low temperatures. Large losses of HNO3 and nitrate, which are highly water soluble, occurred in the free troposphere, most likely due to wet removal by precipitation. This has been shown to be the major pathway of NOy loss in the middle troposphere. Increases in the mixing ratios of O-3 and its precursors due to biomass burning in SEA are estimated using the tracers. Enhancements of CO and total reactive nitrogen ( NOy), which are directly emitted from biomass burning, were largest at 2 - 4 km. At this altitude the increases in NOy and O-3 were 810 parts per trillion by volume ( pptv) and 26 parts per billion by volume (ppbv) above their background values of 240 pptv and 31 ppbv, respectively. The slope of the O-3-CO correlation in biomass burning plumes was similar to those observed in fire plumes in northern Australia, Africa, and Canada. The O-3 production efficiency ( OPE) derived from the O-3-CO slope and NOx/CO emission ratio ( ER) is shown to be positively correlated with the C2H4/NOx ER, indicating that the C2H4/NOx ER is a critical parameter in determining the OPE. Comparison of the net O-3 flux across the western Pacific region and total O-3 production due to biomass burning in SEA suggests that about 70% of O-3 produced was transported to the western Pacific. C1 Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. Ibaraki Univ, Dept Environm Sci, Mito, Ibaraki 3108512, Japan. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. SW Sci Inc, Santa Fe, NM USA. Georgia Inst Technol, Dept Earth & Atmospher Sci, Atlanta, GA 30332 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Natl Inst Water & Atmospher Res, Lauder, New Zealand. RP Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, 4-6-1 Komaba, Tokyo 1538904, Japan. EM kondo@atmos.rcast.u-tokyo.ac.jp; morino@atmos.rcast.u-tokyo.ac.jp; takegawa@atmos.rcast.u-tokyo.ac.jp; koike@eps.s.u-tokyo.ac.jp; kita@env.sci.ibaraki.ac.jp; yuzom@atmos.rcast.u-tokyo.ac.jp; g.w.sachse@larc.nasa.gov; s.a.vay@larc.nasa.gov; m.a.avery@larc.nasa.gov; ffl@acd.ucar.edu; wein@ucar.edu; eisele@ucar.edu; mzondlo@swsciences.com; rweber@eas.gatech.edu; hsingh@mail.arc.nasa.gov; g.chen@larc.nasa.gov; j.h.crawford@larc.nasa.gov; drblake@uci.edu; fuelberg@met.fsu.edu; tclarke@soest.hawaii.edu; robert.talbot@unh.edu; scott.sandholm@eas.gatech.edu; edward.v.browell@nasa.gov; dstreets@anl.gov; b.liley@niwa.co.nz RI Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012; Miyazaki, Yuzo/C-6920-2010; Crawford, James/L-6632-2013; Zondlo, Mark/R-6173-2016; OI Crawford, James/0000-0002-6982-0934; Zondlo, Mark/0000-0003-2302-9554; Liley, Ben/0000-0002-8844-7928; Streets, David/0000-0002-0223-1350 NR 70 TC 43 Z9 44 U1 4 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 JUL 1 PY 2004 VL 109 IS D15 AR D15S12 DI 10.1029/2003JD004203 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 839JQ UT WOS:000222780600002 ER PT J AU O'Sullivan, DW Heikes, BG Snow, J Burrow, P Avery, M Blake, DR Sachse, GW Talbot, RW Thornton, DC Bandy, AR AF O'Sullivan, DW Heikes, BG Snow, J Burrow, P Avery, M Blake, DR Sachse, GW Talbot, RW Thornton, DC Bandy, AR TI Long-term and seasonal variations in the levels of hydrogen peroxide, methylhydroperoxide, and selected compounds over the Pacific Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE peroxides; distributions; troposphere ID PEM-WEST-B; ASIAN CONTINENTAL OUTFLOW; AIR-MASS CHARACTERISTICS; EXPLORATORY MISSION; GAS-PHASE; NORTH PACIFIC; CHEMICAL EVOLUTION; ORGANIC HYDROPEROXIDES; TROPOSPHERIC METHANE; SOUTH-PACIFIC AB [1] The National Aeronautics and Space Administration's Global Tropospheric Experiment program has conducted five sampling programs examining the Pacific troposphere from 1991 to 2001. Flights on two aircraft, a P3-B and DC-8, sampled the Pacific troposphere at altitudes from 0.5 km to 13 km and from 130 degreesE to 115 degreesW and from 65 degreesN to 70 degreesS. Long-term trends in the observed species mixing ratios in different geographic regions are presented. Changes in species mixing ratios are discussed with respect to changes in source, transport, and photochemical production and loss processes over the decade study period. CH4 and CO2 exhibited average annual mixing ratio increases of 6.39 ppbv yr(-1) and 1.92 ppmv yr(-1), respectively. O-3, CO, and NO all exhibit significantly higher mixing ratios in the north Pacific troposphere in the spring than in the fall. However, there is no clear annual trend for these species. H2O2 mixing ratios were 38 +/- 16% higher (Delta(fall - spring) 258 +/- 34 pptv), and CH3OOH was 61 +/- 15% higher (Delta343 +/- 76 pptv) throughout the Pacific troposphere in the fall than in the spring. During 2001, SO2 loading in the North Pacific is 2 - 3 times larger than during earlier years. Anthropogenic tracer gases, C2H6, C3H8, C2H2, and C2Cl4, do not exhibit comparable increases in their average mixing ratios during the decade study period. CH3I, a tracer for oceanic emission, also does not exhibit an increase in 2001. Sulfur loading characterized by SO2 also does not exhibit a clear annual trend. The enhanced sulfur loading during 2001 appears to have resulted in a suppression of H2O2 mixing ratios in the lower troposphere throughout the midlatitude North Pacific. C1 USN Acad, Dept Chem, Annapolis, MD 21402 USA. Univ Rhode Isl, Grad Sch Oceanog, Ctr Atmospher Chem Studies, Narragansett, RI 02882 USA. NASA, Div Atmospher Sci, Langley Res Ctr, Hampton, VA 23665 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92717 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. RP USN Acad, Dept Chem, Annapolis, MD 21402 USA. EM osulliva@usna.edu OI O'Sullivan, Daniel/0000-0001-9104-5703 NR 61 TC 12 Z9 12 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUL 1 PY 2004 VL 109 IS D15 AR D15S13 DI 10.1029/2003JD003689 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 839JQ UT WOS:000222780600001 ER PT J AU Ho, DT Zappa, CJ McGillis, WR Bliven, LF Ward, B Dacey, JWH Schlosser, P Hendricks, MB AF Ho, DT Zappa, CJ McGillis, WR Bliven, LF Ward, B Dacey, JWH Schlosser, P Hendricks, MB TI Influence of rain on air-sea gas exchange: Lessons from a model ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE gas exchange; rain; SF6; turbulence; stratification ID MICROSCALE WAVE BREAKING; THERMAL-BOUNDARY LAYER; TOTAL HEAT FLOW; SURFACE TEMPERATURE; WIND-SPEED; CAPILLARY WAVES; WATER; LAKE; SKIN; DISSIPATION AB Rain has been shown to significantly enhance the rate of air-water gas exchange in fresh water environments, and the mechanism behind this enhancement has been studied in laboratory experiments. In the ocean, the effects of rain are complicated by the potential influence of density stratification at the water surface. Since it is difficult to perform controlled rain-induced gas exchange experiments in the open ocean, an SF6 evasion experiment was conducted in the artificial ocean at Biosphere 2. The measurements show a rapid depletion of SF6 in the surface layer due to rain enhancement of air-sea gas exchange, and the gas transfer velocity was similar to that predicted from the relationship established from freshwater laboratory experiments. However, because vertical mixing is reduced by stratification, the overall gas flux is lower than that found during freshwater experiments. Physical measurements of various properties of the ocean during the rain events further elucidate the mechanisms behind the observed response. The findings suggest that short, intense rain events accelerate gas exchange in oceanic environments. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. Columbia Univ, Dept Earth & Environm Sci, New York, NY USA. Woods Hole Oceanog Inst, Dept Appl Ocean Phys & Engn, Woods Hole, MA 02543 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Isl, VA 23337 USA. Woods Hole Oceanog Inst, Dept Biol, Woods Hole, MA 02543 USA. Columbia Univ, Dept Earth & Environm Engn, New York, NY USA. Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. RP Ho, DT (reprint author), Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. EM david@ldeo.columbia.edu; zappa@ldeo.columbia.edu; mcgillis@ldeo.columbia.edu; francis.l.bliven@nasa.gov; bward@whoi.edu; jdacey@whoi.edu; schlosser@ldeo.columbia.edu RI Ho, David/A-3154-2011; Schlosser, Peter/C-6416-2012; bliven, francis/E-1450-2012 OI Ho, David/0000-0002-0944-6952; Schlosser, Peter/0000-0002-6514-4203; NR 61 TC 23 Z9 23 U1 0 U2 14 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 JUL 1 PY 2004 VL 109 IS C8 AR C08S18 DI 10.1029/2003JC001806 PG 15 WC Oceanography SC Oceanography GA 839JY UT WOS:000222781400001 ER PT J AU Bryant, RG Effinger, RT Aranda, I Copeland, BM Covington, EW Hogge, JM AF Bryant, RG Effinger, RT Aranda, I Copeland, BM Covington, EW Hogge, JM TI Radial field piezoelectric diaphragms SO JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES LA English DT Article DE piezoelectric actuators; piezoelectric diaphragms; active materials; radial field diaphragms; NASA RFD AB A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "IRE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezo-ceramic along the Z-axis (perpendicular to the applied electric field). Unlike piezoelectric bender actuators, the Radial Field Diaphragm (RFD) strains concentrically yet affords high displacements without any appreciable XY-strain beyond its perimeter, as both the radial and tangential strain field approach zero at the boundary independent of actuator movement. The result is a Z-axis deflection that has a conical profile. This article covers the fabrication and characterization of these RFDs as a function of poling field strength, ceramic thickness and geometry, electrode type, line spacing, surface topography, the resulting localized strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs are the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging and a highly repeatable fabrication process that uses commodity materials. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Texas A&M, Dept Mech Engn, College Stn, TX 77840 USA. Texas A&M, Dept Mech Engn, Kingsville, TX 78363 USA. RP Bryant, RG (reprint author), NASA, Langley Res Ctr, MS 226, Hampton, VA 23681 USA. EM Robert.G.Bryant@nasa.gov NR 11 TC 9 Z9 9 U1 0 U2 0 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1045-389X J9 J INTEL MAT SYST STR JI J. Intell. Mater. Syst. Struct. PD JUL PY 2004 VL 15 IS 7 BP 527 EP 538 DI 10.1177/1045389X04041646 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 840TW UT WOS:000222883800003 ER PT J AU Hall, TM Haine, TWN AF Hall, TM Haine, TWN TI Tracer age symmetry in advective-diffusive flows SO JOURNAL OF MARINE SYSTEMS LA English DT Article; Proceedings Paper CT 34th International Liege Colloquium on Ocean Dynamics CY MAY 06-10, 2002 CL Liege, BELGIUM DE tracers; age; ocean transport; advection-diffusion ID TRANSPORT; MODEL; WATER AB The "age" of a trace constituent is a common diagnostic of its transport in a geophysical flow. Deleersnijder et al. (Bull. Soc. R. Sci. Liege 70 (2001a) 5) and Beckers et al. (SIAM J. Appl. Math. 61 (2001) 1526) analyzed tracers released from point sources in unbounded advective-diffusive flows with uniform coefficients and noted a surprising feature: the "mean tracer age" (the averaged elapsed time since tracer was injected) is symmetric about the source, despite the directionality of the flow. Although the majority of tracer is swept downstream, the small fraction that diffuses upstream does so at the same average rate. We explore this symmetry physically by examining the random walk trajectories that underlie the advective-diffusive description of transport. Using physical arguments, we show that symmetry in the tracer age field is a natural consequence of symmetry in the velocity and diffusivity fields. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Johns Hopkins Univ, Baltimore, MD USA. RP Hall, TM (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM thall@giss.nasa.gov; Thomas.Haine@jhu.edu NR 12 TC 7 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-7963 J9 J MARINE SYST JI J. Mar. Syst. PD JUL PY 2004 VL 48 IS 1-4 BP 51 EP 59 DI 10.1016/j.jmarsys.2003.01.001 PG 9 WC Geosciences, Multidisciplinary; Marine & Freshwater Biology; Oceanography SC Geology; Marine & Freshwater Biology; Oceanography GA 837GP UT WOS:000222617000005 ER PT J AU Dickinson, DN La Duc, MT Satomi, M Winefordner, JD Powell, DH Venkateswaran, K AF Dickinson, DN La Duc, MT Satomi, M Winefordner, JD Powell, DH Venkateswaran, K TI MALDI-TOFMS compared with other polyphasic taxonomy approaches for the identification and classification of Bacillus pumilus spores SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE Bacillus; spores; mass spectrometry; protein profiling ID FLIGHT MASS-SPECTROMETRY; BACTERIAL SYSTEMATICS; WHOLE CELLS; STRAINS; RESISTANCE; SPACECRAFT AB To verify the efficacy of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) protein profiling for identifying and differentiating bacterial species, several strains of Bacillus pumilus were examined in a thorough taxonomic study incorporating a polyphasic approach. Sixteen isolates of putative B. pumilus isolated from spacecraft assembly facilities, the Mars Odyssey spacecraft, and the International Space Station, were characterized for their biochemical and molecular profiles using the Biolog system, DNA techniques, and MALDI-TOFMS protein profiling. MALDI-TOFMS protein profiling was more accurate than Biolog metabolic profiling, more discriminating than 16S rDNA sequence analysis, and complemented the results of gyrB sequence analysis and DNA-DNA hybridization for the identification of the B. pumilus spores. This is the first report whereby MALDI-TOFMS generated protein profiles from a set of microbes is compared directly with DNA-DNA hybridization yielding a positive correlation. Unique, cluster-specific biomarker peaks have been identified in the spores of the B. pumilus examined in this study. MALDI-TOFMS protein profiling is a rapid and simple analysis and has been demonstrated as a useful taxonomic tool for differentiating spores of the genus Bacillus. For practical purposes, it would be ideal (and necessary) to have a publicly available, standardized MALDI profile database, to facilitate the use of the technique as a diagnostic method to differentiate bacterial species. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Florida, Dept Chem, Gainesville, FL 32611 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Inst Fisheries Japan, Kanagawa, Japan. RP Dickinson, DN (reprint author), Univ Florida, Dept Chem, POB 117200, Gainesville, FL 32611 USA. EM danielled@chem.ufl.edu NR 33 TC 24 Z9 28 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD JUL PY 2004 VL 58 IS 1 BP 1 EP 12 DI 10.1016/j.mimet.2004.02.011 PG 12 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 830VK UT WOS:000222151900001 PM 15177898 ER PT J AU Phinney, LM Lin, G Wellman, J Garcia, A AF Phinney, LM Lin, G Wellman, J Garcia, A TI Surface roughness measurements of micromachined polycrystalline silicon films SO JOURNAL OF MICROMECHANICS AND MICROENGINEERING LA English DT Article ID POLYSILICON FILMS; MEMS; FRICTION; STICTION AB The characteristics of the materials and surfaces in microelectromechanical systems (MEMS) and microsystems technology (MST) profoundly affect the performance, reliability, and wear of MEMS and MST devices. It is critical to measure the properties of surfaces that are in contact during microstructure movement, such as the underside of a MEMS gear and the underlying substrate. However, contacting surfaces are usually inaccessible unless the MEMS device is broken and removed from the substrate. This paper presents a nondestructive method for characterizing commercially fabricated surface micromachined polycrystalline silicon (polysilicon) devices. Microhinged flaps were designed that enable access to the upper surface, the part of a structural layer deposited last; the lower surface, the part of a structural layer deposited first; and the underlying substrate. Due to the susceptibility of surface-micromachined MEMS to adhesion failures, the surface roughness is a key parameter for predicting device behavior. Using the microhinged flaps, the RMS surface roughness for polycrystalline surfaces was measured and indicated that the upper surfaces were 3.5-6.4 times rougher than the lower surfaces. The difference in the surface roughness for the upper surface, which is easily accessed and the one most commonly characterized, and that for the lower surface reveals the importance of characterizing contacting surfaces in MEMS and MST devices. C1 Univ Illinois, Dept Mech & Ind Engn, Urbana, IL 61801 USA. Univ Calif Irvine, Dept Biomed Engn, Irvine, CA 92697 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Phinney, LM (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 19 TC 12 Z9 12 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0960-1317 J9 J MICROMECH MICROENG JI J. Micromech. Microeng. PD JUL PY 2004 VL 14 IS 7 BP 927 EP 931 AR PII S0960-1317(04)65675-5 DI 10.1088/0960-1317/14/7/012 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation; Physics, Applied SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation; Physics GA 843NG UT WOS:000223090000012 ER PT J AU Smith, SM Davis-Street, JE Fesperman, JV Smith, MD Rice, BL Zwart, SR AF Smith, SM Davis-Street, JE Fesperman, JV Smith, MD Rice, BL Zwart, SR TI Nutritional status changes in humans during a 14-day saturation dive: The NASA Extreme Environment Mission Operations V project SO JOURNAL OF NUTRITION LA English DT Article; Proceedings Paper CT Experimental Biology 2004 Meeting CY APR 17-21, 2004 CL Washington, DC DE saturation diving; hyperbaric; nutrition; spaceflight analog ID RED-CELL MASS; SPACE-FLIGHT; SERUM FERRITIN; BED REST; NEOCYTOLYSIS; SPACEFLIGHT; HYPEROXIA; MECHANISM; RESPONSES; EXERCISE AB Ground-based analogs of spaceflight are an important means of studying physiologic and nutritional changes associated with space travel, and the NASA Extreme Environment Mission Operations V (NEEMO) is such an analog. To determine whether saturation diving has nutrition-related effects similar to those of spaceflight, we conducted a clinical nutritional assessment of the NEEMO crew (4 men, 2 women) before, during, and after their 14-d saturation dive. Blood and urine samples were collected before, during, and after the dive. The foods consumed by the crew were typical of the spaceflight food system. A number of physiologic changes were observed, during and after the dive, that are also commonly observed during spaceflight. Hemoglobin and hematocrit were lower (P < 0.05) after the dive. Transferrin receptors were significantly lower immediately after the dive. Serum ferritin increased significantly during the dive. There was also evidence indicating that oxidative damage and stress increased during the dive. Glutathione peroxidase and superoxide dismutase decreased during and after the dive (P < 0.05). Decreased leptin during the dive (P < 0.05) may have been related to the increased stress. Subjects had decreased energy intake and weight loss during the dive, similar to what is observed during spaceflight. Together, these similarities to spaceflight provide a model to use in further defining the physiologic effects of spaceflight and investigating potential countermeasures. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Enterprise Advisory Serv Inc, Houston, TX 77058 USA. RP Smith, SM (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM scott.m.smith@nasa.gov NR 33 TC 23 Z9 26 U1 1 U2 6 PU AMER INST NUTRITION PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0022-3166 J9 J NUTR JI J. Nutr. PD JUL PY 2004 VL 134 IS 7 BP 1765 EP 1771 PG 7 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 836UP UT WOS:000222581600016 PM 15226467 ER PT J AU Glazman, RE Golubev, YN AF Glazman, RE Golubev, YN TI Validation of the theoretical spectrum of baroclinic inertia-gravity waves SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID INTERNAL WAVES; SURFACE MANIFESTATION; SHALLOW-WATER; DEEP-OCEAN; TURBULENCE; THERMOCLINE; DISSIPATION; MODELS; TIDES; FIELD AB Assuming nonlinear dynamics of baroclinic inertia-gravity ( BIG) waves to be dominated by resonant four-wave interactions, recent studies yielded simple analytical expressions for the energy spectra. The only parameter remaining unknown is a nondimensional constant of proportionality alpha, referred to as a "Kolmogorov constant'' in wave turbulence theory. The goals of the present study are 1) to validate the theoretical spectrum of the kinetic wave energy by comparing it with observed frequency spectra of horizontal velocities and 2) to obtain the first empirical estimate of alpha for this model. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Glazman, RE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM reg@pacific.jpl.nasa.gov NR 31 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD JUL PY 2004 VL 34 IS 7 BP 1506 EP 1514 DI 10.1175/1520-0485(2004)034<1506:VOTTSO>2.0.CO;2 PG 9 WC Oceanography SC Oceanography GA 839NC UT WOS:000222790800003 ER PT J AU Oyama, A Liou, MS Obayashi, S AF Oyama, A Liou, MS Obayashi, S TI Transonic axial-flow blade optimization: Evolutionary algorithms/three-dimensional Navier-Stokes solver SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA/ISSMO 9th Symposium on Multidisciplinary Analysis and Optimization CY SEP 04-06, 2002 CL ATLANTA, GA SP Amer Inst Aeronaut & Astronaut, ISSMO ID DESIGN AB The development of a high-fidelity aerodynamic design optimization tool based on evolutionary algorithms for turbomachinery is attempted. A three-dimensional Navier-Stokes solver was used for aerodynamic analysis, so that flowfields would be represented accurately and so that realistic and reliable designs would be produced. For efficient and robust design optimization, the real-coded adaptive range genetic algorithm was adopted, and the computation was parallelized and performed on an SGI Origin 2000 cluster to reduce turnaround time. The aerodynamic redesign of the NASA rotor 67 blade demonstrated the superiority of the present method over the conventional design approach, increasing adiabatic efficiency by 2% over the original design. This increase is achieved not only at the design condition, but over the entire operating range. This design optimization method has proven to be suitable for parallel computing. This promising tool is shown to help turbomachinery designers to design higher-performance machines while shortening the design cycle and reducing design costs. C1 NASA, Glenn Res Ctr, Turbomachinery & Propuls Syst Div, Cleveland, OH 44135 USA. Tohoku Univ, Inst Fluid Sci, Sendai, Miyagi 9808577, Japan. RP Oyama, A (reprint author), Japan Aerospace Explorat Agcy, Inst Space & Astronaut Sci, Div Space Transportat Engn, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 2298510, Japan. EM oyama@flab.eng.isas.jaxa.jp; meng-sing.liou-1@nasa.gov; obayashi@ieee.org NR 32 TC 49 Z9 58 U1 1 U2 7 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 2004 VL 20 IS 4 BP 612 EP 619 DI 10.2514/1.2290 PG 8 WC Engineering, Aerospace SC Engineering GA 840DC UT WOS:000222836200004 ER PT J AU De Zilwa, S Zilliac, G Reinath, M Karabeyoglu, A AF De Zilwa, S Zilliac, G Reinath, M Karabeyoglu, A TI Time-resolved fuel-grain port diameter measurement in hybrid rockets SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA/ASME/SAE/ASEE 39th Joint Propulsion Conference CY JUL 20, 2003 CL Huntsville, AL SP AIAA, ASME, SAE, ASEE ID REGRESSION RATES AB A novel technique is presented for determining the instantaneous spatially averaged port diameter of solid-fuel grains in hybrid rocket motors. This technique requires measurement of the frequency of the Helmholtz oscillation of the motor and is based on the principle that this frequency is inversely proportional to the square root of the chamber volume. This technique was applied to a hybrid rocket motor burning paraffin wax with gaseous oxygen. The calculated variation of port diameter agreed well with the correlation for average regression rate, determined from mass loss during operation. A major advantage is that the only instrumentation required for implementing this technique is a high-speed pressure transducer or a photomultiplier tube. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Stanford Univ, Dept Aeronaut & Astronaut, Stanford, CA 94305 USA. RP De Zilwa, S (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA USA. NR 15 TC 6 Z9 6 U1 0 U2 3 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 2004 VL 20 IS 4 BP 684 EP 689 DI 10.2514/1.2188 PG 6 WC Engineering, Aerospace SC Engineering GA 840DC UT WOS:000222836200011 ER PT J AU Vaidyanathan, R Tucker, PK Papila, N Shyy, W AF Vaidyanathan, R Tucker, PK Papila, N Shyy, W TI Computational-fluid-dynamics-based design optimization for single-element rocket injector SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID PREDICTION AB A computational-fluid-dynamics-based design optimization approach, utilizing the response surface method, has been proposed for a single-element rocket injector. The overall goal of the effort is to demonstrate the integration of a set of computational and optimization tools to enable the injector designer to objectively determine the trades between performance and life during the design cycle. Using design of experiment techniques, 54 cases are selected, and computational solutions based on the Navier-Stokes equations, finite rate chemistry, and the k-epsilon turbulence closure are obtained. The response surface methodology is employed as the optimization tool. Four independent design variables are selected, namely, H-2 flow angle, H-2 and O-2 flow areas with fixed flow rates, and O-2 posttip thickness. Design optimization is guided by four design objectives. The maximum temperature on the injector element oxidizer posttip, the maximum temperature on the injector face, and a combustion chamber wall temperature are chosen as life indicators. The length of the combustion zone is selected as an indicator of mixing and performance. In the context of this effort, the design optimization tools performed efficiently and reliably. In addition to establishing optimum designs by varying emphasis on the individual objectives, better insight into the interplay between design variables and their impact on the design objectives is gained. The need to include environmental design objectives early in the design phase is clearly established. C1 Univ Florida, Dept Mech & Aerosp Engn, Gainesville, FL 32611 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Vaidyanathan, R (reprint author), Univ Florida, Dept Mech & Aerosp Engn, Gainesville, FL 32611 USA. NR 23 TC 12 Z9 20 U1 0 U2 3 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 2004 VL 20 IS 4 BP 705 EP 717 DI 10.2514/1.11464 PG 13 WC Engineering, Aerospace SC Engineering GA 840DC UT WOS:000222836200014 ER PT J AU Litchford, RJ AF Litchford, RJ TI Performance theory of diagonal conducting wall magnetohydrodynamic accelerators SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA 34th Plasmadynamics and Laser Conference CY JUN 23, 2003 CL ORLANDO, FL SP Amer Inst Aeronaut & Astronaut ID PLASMA AB The theoretical performance of diagonal conducting wall crossed field accelerators is examined on the basis of an infinite segmentation assumption using a cross-plane averaged generalized Ohm's law for a partially ionized gas, including ion slip. The desired accelerator performance relationships are derived from the cross-plane averaged Ohm's law by the imposition of appropriate configuration and power-connection constraints. A current dependent effective voltage drop model is also incorporated to account for cold-wall boundary-layer effects, including gasdynamic variations, discharge constriction, and electrode falls. Definition of dimensionless electric fields and current densities lead to the construction of graphical performance diagrams, which further illuminate the rudimentary behavior of crossed field accelerator operation. C1 NASA, George C Marshall Space Flight Ctr, Prop Res Lab, Energet Res Grp, Huntsville, AL 35812 USA. RP Litchford, RJ (reprint author), NASA, George C Marshall Space Flight Ctr, Prop Res Lab, Energet Res Grp, TD40, Huntsville, AL 35812 USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JUL-AUG PY 2004 VL 20 IS 4 BP 742 EP 750 DI 10.2514/1.3698 PG 9 WC Engineering, Aerospace SC Engineering GA 840DC UT WOS:000222836200018 ER PT J AU Exton, RJ Balla, RJ AF Exton, RJ Balla, RJ TI ArF laser excitation, collisional transfer, and quench-free fluorescence in I-2/foreign gas mixtures SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE fluorescence; iodine; rate coefficients; quenching ID MOLECULAR-IODINE; ION-PAIR; I-2; STATE; I2; TRANSITIONS; SIMULATIONS; BANDS; ARGON AB Fluorescence of I? excited by an ArF excimer laser at 193 nm has been studied in the presence of 10 buffer gases (He, Ne, Ar, Kr, Xe, N-2, O-2, air, CF4, and SF6) over the pressure range from 0 to 700 Torr. At low pressure, the fluorescence is dominated by the bound-bound and bound-free (McLennan band) emission for D(1)Z(u)(divided by) --> X(1)Sigma(g)(divided by). With increasing pressure, significant fractions of the D state population are collisionally transferred to the D' state; this results in strong D'(3) Pi(2g) --> A'(3) Pi(2u) band flourescence at 340 nm. A simple four-level model is developed to describe these processes. Quenching and transfer rate coefficients are measured for the 10 gases. With the exception of Xe, O-2, and air, which exhibit reactive quenching in addition to collisional quenching, the 340-nm-band fluorescence is resistant to quenching. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Adv Measurement & Diagnost Branch, Hampton, VA 23681 USA. RP Exton, RJ (reprint author), NASA, Langley Res Ctr, Adv Measurement & Diagnost Branch, Hampton, VA 23681 USA. EM r.j.exton@larc.nasa.gov NR 26 TC 12 Z9 12 U1 0 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 1 PY 2004 VL 86 IS 3 BP 267 EP 283 DI 10.1016/j.jqsrt.2003.08.006 PG 17 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 820WT UT WOS:000221421100003 ER PT J AU Erlandson, RE Meng, CI Swaminathan, PK Kumar, CK Dogra, VK Stoyanov, BJ Gavrilov, BG Kiselev, Y Zetzer, JI Stenbaek-Nielsen, HC Lynch, KA Pfaff, RF Delamere, PA Bounds, S Gatsonis, NA AF Erlandson, RE Meng, CI Swaminathan, PK Kumar, CK Dogra, VK Stoyanov, BJ Gavrilov, BG Kiselev, Y Zetzer, JI Stenbaek-Nielsen, HC Lynch, KA Pfaff, RF Delamere, PA Bounds, S Gatsonis, NA TI North star plasma-Jet space experiment SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID ION-BEAM; IONOSPHERE AB The objective of the Active Plasma Experiment North Star mission was to study the interaction of artificially produced aluminum ion plasma jets with the space environment. Two separate plasma jets were injected almost perpendicular to the local magnetic field during the North Star experiment. The jets were created using an explosive-type generator designed to produce a high-speed (7-42-km/s) aluminum ion plasma,jet with plasma densities exceeding 10(9) cm(-3) at a distance 170 m from the plasma-jet source. The first plasma-jet injection occurred at an altitude of 360 km and was preceded by the release of an artificial air cloud. The second injection occurred at an altitude of 280 km and did not include the air cloud. Interactions of the plasma jet with the local space environment and artificial air cloud were monitored using instrumentation on three diagnostic payloads, ground-based optical sensors, and space-based optical sensors. An overview is provided of the experiment, along with a summary of the principal results from the mission. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Inst Dynam Geospheres, Moscow 117979, Russia. Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. Dartmouth Coll, Hanover, NH 03755 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Colorado, Boulder, CO 80309 USA. Univ Iowa, Iowa City, IA 52242 USA. Worcester Polytech Inst, Worcester, MA 01609 USA. RP Erlandson, RE (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. RI Swaminathan, Pazhayannur/I-3609-2012; Pfaff, Robert/F-5703-2012; Erlandson, Robert/G-2767-2015 OI Swaminathan, Pazhayannur/0000-0003-1272-9694; Pfaff, Robert/0000-0002-4881-9715; NR 20 TC 6 Z9 6 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JUL-AUG PY 2004 VL 41 IS 4 BP 483 EP 489 DI 10.2514/1.11943 PG 7 WC Engineering, Aerospace SC Engineering GA 844WC UT WOS:000223190800002 ER PT J AU Gavrilov, BG Podgorny, IM Sobyanin, DB Zetzer, JI Erlandson, RE Meng, CI Pfaff, RF Lynch, KA AF Gavrilov, BG Podgorny, IM Sobyanin, DB Zetzer, JI Erlandson, RE Meng, CI Pfaff, RF Lynch, KA TI North star plasma-jet experiment particles and electric and magnetic field measurements SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID GEOMAGNETIC-FIELD; SIMULATION; FLUXUS-1 AB The results of measurements of magnetic and electric fields, plasma ions energy, and plasma density during the Russian-American North Star active experiment are presented. The experiment was carried out in the auroral ionosphere on 22 January 1999. A Black Brant XII rocket, having two explosive aluminum plasma generators plus scientific payloads onboard, was launched at 13:57:03 UT from Poker Flat, Alaska. Two plasma-jet injections across the magnetic field were made at the altitudes 280 and 360 km, respectively. Before injection 1, an air cloud was released to increase jet ionization. At injection 1, the maximum plasma density exceeded the density at injection 2 by two orders of magnitude. This can be explained by charge stripping of aluminum atoms when the jet propagated through the dense air cloud. Only at injection 1 was complete expelling of the magnetic field by the plasma jet observed. A weak plasma deceleration was indicated by magnetic field compression before the jet front. At injection 2, the magnetic field was weakened only by 1%. A polarization electric field E = -V x B generated field-aligned currents, which involved the ionospheric plasma in motion, and the plasma jet efficiently decelerated. C1 Russian Acad Sci, Moscow 117334, Russia. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ New Hampshire, Durham, NH 03824 USA. RP Gavrilov, BG (reprint author), Russian Acad Sci, Moscow 117334, Russia. EM gavrilov@idg.chph.ras.ru; sobyanin@idg.chph.ras.ru; zertzer@idg.chph.ras.ru; erlandson@jhuapl.edu; ching.meng@jhuapl.edu; rob.pfaff@gsfc.nasa.gov; lynch@birkeland.Dartmouth.edu RI Pfaff, Robert/F-5703-2012; Erlandson, Robert/G-2767-2015 OI Pfaff, Robert/0000-0002-4881-9715; NR 12 TC 6 Z9 6 U1 0 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 2004 VL 41 IS 4 BP 490 EP 495 DI 10.2514/1.11948 PG 6 WC Engineering, Aerospace SC Engineering GA 844WC UT WOS:000223190800003 ER PT J AU Delamere, EA Stenbaek-Nielsen, HC Pfaff, RF Erlandson, RE Meng, CI Zetzer, JI Kiselev, Y Gavrilov, BG AF Delamere, EA Stenbaek-Nielsen, HC Pfaff, RF Erlandson, RE Meng, CI Zetzer, JI Kiselev, Y Gavrilov, BG TI Dynamics of the active plasma experiment north star artificial plasma jet SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID RADIATION EFFECTS SATELLITE; HYBRID CODE; COMBINED RELEASE; SIMULATION; IO; MAGNETOSPHERE AB Active Plasma Experiment North Star was launched from Poker Flat Research Range, Alaska, on 22 January 1999 at 13:57:03 UT, with two explosive-type generators that produced an artificial aluminum plasma jet. The purpose of this experiment was to study the interaction of the artificial plasma jet with the ambient plasma. The first release occurred at 363 km, and a similar to90% reduction of the geomagnetic field was observed on three separate daughter payloads. The diamagnetic signatures suggest that the plasma cloud was highly localized (i.e., cloud dimensions similar toAl(+) gyroradius) traveling with a velocity of roughly 25 km/s perpendicular to the geomagnetic field. A hybrid code simulation provided an estimate of the plasma distribution and a qualitative description of the evolution of the plasma cloud. The simulation showed that the plasma cloud polarized and E x B drifted while transferring momentum to the ambient plasma via an Alfvenic disturbance. The model results are in good qualitative agreement with data from the plasma diagnostics payload. C1 Univ Colorado, Boulder, CO 80309 USA. Univ Alaska Fairbanks, Fairbanks, AK 99775 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Inst Dynam Geospheres, Moscow 117979, Russia. RP Delamere, EA (reprint author), Univ Colorado, Boulder, CO 80309 USA. RI Pfaff, Robert/F-5703-2012; Erlandson, Robert/G-2767-2015 OI Pfaff, Robert/0000-0002-4881-9715; NR 14 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 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JUL-AUG PY 2004 VL 41 IS 4 BP 503 EP 508 PG 6 WC Engineering, Aerospace SC Engineering GA 844WC UT WOS:000223190800005 ER PT J AU Pfaff, RF Freudenreich, HT Bounds, SR Delamere, PA Erlandson, RE Meng, CI Zetzer, JI Gavrilov, BG AF Pfaff, RF Freudenreich, HT Bounds, SR Delamere, PA Erlandson, RE Meng, CI Zetzer, JI Gavrilov, BG TI Electric field, magnetic field, and density measurements on the active plasma experiment SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID VELOCITY EXPERIMENT; IONIZATION; WAVES AB High-resolution, in situ measurements of do and wave electric fields, magnetic fields, and plasma number density have been gathered by instruments on a diagnostic payload at which a high-velocity, overdense aluminum ion beam was directed from a separate payload spaced 468 m away. The experiment, called the Active Plasma Physics Experiment, was carried out in the Earth's high-latitude ionosphere at 360-km altitude using a sounding rocket. The experimental data clearly show a large diamagnetic cavity with a 93% depletion of the Earth's magnetic field within a narrowly confined (<500-m) ion beam whose number density exceeded 10(9) cm(-3). Associated with the release, do electric fields with amplitudes >1.5 V/m perpendicular to the magnetic field were observed that represented both the E x B bulk plasma velocity and a magnetosonic wave, which preceded the arrival of the beam that was also evident in the DeltaB magnetometer data. The electric field data also show the presence of electric fields parallel to the magnetic field, including a bipolar electric field signature presumably set up to ensure current continuity. Other plasma waves associated with the release include Alfven perturbations, intense broadband turbulence extending to frequencies beyond 1 MHz, whistler-mode electromagnetic emissions at the ambient O+ lower hybrid frequency, and ion acoustic turbulence. The measurements provide a self-consistent picture of the electrodynamics surrounding a high-velocity, overdense ion beam released in the high-latitude ionosphere. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Colorado, Boulder, CO 80309 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Inst Geosphere Dynam, Moscow 117334, Russia. RP Pfaff, RF (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Pfaff, Robert/F-5703-2012; Erlandson, Robert/G-2767-2015 OI Pfaff, Robert/0000-0002-4881-9715; NR 14 TC 8 Z9 8 U1 0 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JUL-AUG PY 2004 VL 41 IS 4 BP 521 EP 532 DI 10.2514/1.11945 PG 12 WC Engineering, Aerospace SC Engineering GA 844WC UT WOS:000223190800007 ER PT J AU Fang, HF Lou, M Huang, J Hsia, LM Kerdanyan, G AF Fang, HF Lou, M Huang, J Hsia, LM Kerdanyan, G TI Inflatable structure for a three-meter reflectarray antenna SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC/SDM 43rd Structures, Structural Dynamics, and Materials Conference CY APR 22-25, 2002 CL DENVER, CO SP AIAA, ASME, ASCE, AHS, ASC AB The application of inflatable/rigidizable structures technology has become feasible for near-term large space antennas. The development of one of such application of a 3-m Ka-band reflectarray antenna is discussed. This antenna employs the beam scanning and circular polarization technology that allows the use of a flat surface instead of a parabolic antenna surface. Structurally, a flat surface is comparatively easier to fabricate, package, and maintain than a curved parabolic surface. The development of this antenna was also supported by an innovative inflatable/self-rigidizable boom technology, namely spring tape reinforced aluminum laminate boom. A spring tape reinforced aluminum laminate boom automatically rigidizes after it is deployed by inflation pressure. The rigidization of this boom requires no space power, curing agent, or other added-on rigidization devices. Small damage caused by micrometeoroid impacts will not affect structural performance of the boom, and inflation air is no longer needed after the boom is deployed. Detailed mechanical design, dynamic analysis, and deployment demonstration of the antenna are discussed. C1 CALTECH, Jet Prop Lab, Mech Syst Engn & Res Div, Pasadena, CA 91109 USA. Calif State Univ Los Angeles, Telecommun Sci & Engn Div, Los Angeles, CA 90032 USA. RP Fang, HF (reprint author), CALTECH, Jet Prop Lab, Mech Syst Engn & Res Div, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 3 Z9 4 U1 1 U2 7 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 2004 VL 41 IS 4 BP 543 EP 550 DI 10.2514/1.11942 PG 8 WC Engineering, Aerospace SC Engineering GA 844WC UT WOS:000223190800010 ER PT J AU McConaghy, TT Longuski, JA Byrnes, DV AF McConaghy, TT Longuski, JA Byrnes, DV TI Analysis of a class of Earth-Mars cycler trajectories SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID RESTRICTED 3-BODY PROBLEM; PERIODIC-ORBITS; STABILITY; FAMILIES; FLIGHT; MOON; MASS AB Sun-orbiting spacecraft trajectories that repeatedly encounter Earth and Mars may play a central role in a future Earth-Mars transportation system. Such orbits are known as Earth-Mars cycler trajectories (cyclers). By using gravity-assist maneuvers at Earth or Mars, many cyclers can avoid using large amounts of propellant. The known cyclers were found using heuristics or numerical searches. We describe a new, systematic method for constructing and evaluating cyclers. Our method reveals that previously known cyclers, such as the Aldrin cycler and the Versatile International Station for Interplanetary Transport cyclers, belong to a larger family of cyclers. Our cycler construction method also reveals some previously unknown cyclers. For example, we identify a new cycler that repeats every two synodic periods and has a low V-infinity at Earth and Mars (5.65 and 3.05 km/s, respectively). C1 Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. CALTECH, Jet Prop Lab, Navigat & Mission Design Sect, Pasadena, CA 91109 USA. RP McConaghy, TT (reprint author), Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. NR 36 TC 12 Z9 14 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JUL-AUG PY 2004 VL 41 IS 4 BP 622 EP 628 DI 10.2514/1.11939 PG 7 WC Engineering, Aerospace SC Engineering GA 844WC UT WOS:000223190800019 ER PT J AU Duren, RM AF Duren, RM TI Validation and verification of deep-space missions SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID MODEL AB The growing technical complexity of and increased cost pressure on deep-space science missions poses challenges for the system engineering discipline of mission validation and verification (V&V). In the wake of several recent mission failures, the aerospace community is still searching for a stable middle ground between the highly reliable yet cost-prohibitive approaches of the past and cheaper but excessively risky methods of project implementation. The key components of a robust mission level V&V program are presented, with attention on the guiding principles and considerations. The concept that a V&V program should be "three dimensional" is discussed, for example, the end-to-end aspect or width, the top-to-bottom aspect or depth, and the project life-cycle aspect or time. Distinctions are made between definition-phase requirements validation and implementation-phase system validation and verification. The role of modeling and simulation relative to system testing and the necessity of model validation are described. Validation of system robustness using techniques such as performance sensitivity analysis, system fault tree analysis, probabilistic risk analysis, and stress testing is explored. Finally, a summary V&V checklist is provided. C1 CALTECH, Jet Prop Lab, Mission & Syst Architecture Sect, Pasadena, CA 91109 USA. RP Duren, RM (reprint author), CALTECH, Jet Prop Lab, Mission & Syst Architecture Sect, 4800 Oak Grove Dr,Mail Stop 301-450, Pasadena, CA 91109 USA. NR 15 TC 3 Z9 3 U1 1 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JUL-AUG PY 2004 VL 41 IS 4 BP 651 EP 658 DI 10.2514/1.1641 PG 8 WC Engineering, Aerospace SC Engineering GA 844WC UT WOS:000223190800023 ER PT J AU Yeo, H Bousman, WG Johnson, W AF Yeo, H Bousman, WG Johnson, W TI Performance analysis of a utility helicopter with standard and advanced rotors SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT American-Helicopter-Society-Aerodynamics-Acoustics-and Test and Evaluation Technical Specialists Meeting CY JAN 23-25, 2002 CL SAN FRANCISCO, CA SP Amer Helicopter Soc Aerodynam Acoust AB Flight test measurements of the performance of the UH-60 Black Hawk helicopter with both standard and advanced rotors are compared with calculations obtained using the comprehensive helicopter analysis CAMRAD II. In general, the calculated power coefficient shows good agreement with the flight test data. However, the accuracy of the calculation degrades at high gross weight for all of the configurations. The analysis shows fair to good correlation for collective and longitudinal cyclic angles and pitch attitude, and poor to fair correlation for the lateral trim quantities (lateral cyclic angle and roll attitude). The increased solidity of the wide chord blade appears to be a dominant factor in the performance improvement at high gross weight by reducing blade loading and thus delaying stall. C1 NASA, Ames Res Ctr, Raytheon ITSS, Moffett Field, CA 94035 USA. USA, Rotorcraft Div, Aeroflightdynam Directorate, AMRDEC,Aviat & Missile Command,Ames Res Ctr, Moffett Field, CA USA. RP Yeo, H (reprint author), NASA, Ames Res Ctr, Raytheon ITSS, Moffett Field, CA 94035 USA. NR 11 TC 30 Z9 31 U1 0 U2 2 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JUL PY 2004 VL 49 IS 3 BP 250 EP 270 PG 21 WC Engineering, Aerospace SC Engineering GA 844EJ UT WOS:000223139900003 ER PT J AU Corfeld, KJ Strawn, RC Long, LN AF Corfeld, KJ Strawn, RC Long, LN TI Computational aerodynamics analysis of a martian rotorcraft SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article AB This paper presents Reynolds-averaged Navier-Stokes calculations for a prototype Martian rotorcraft. These computational simulations present a new and challenging problem, since rotors that operate on Mars will experience a unique low Reynolds number and high Mach number environment. Computed results for the three-dimensional (3-D) rotor differ substantially from two-dimensional (2-D) sectional computations in that the 3-D results exhibit a stall delay phenomenon caused by rotational forces and 3-D effects along the blade span. Computational results have yet to be compared to experimental data, but computed performance predictions match the experimental design goals fairly well and are compared to 2-D results. In addition, the computed results provide a high level of detail in the rotor wake and blade surface aerodynamics. C1 Penn State Univ, Dept Aerosp Engn, University Pk, PA 16802 USA. USA, Rotorcraft Div, Aviat & Missile Command, Ames Res Ctr, Moffett Field, CA USA. Penn State Univ, Dept Aerosp Engn, University Pk, PA 16802 USA. RP Corfeld, KJ (reprint author), Penn State Univ, Dept Aerosp Engn, University Pk, PA 16802 USA. NR 20 TC 0 Z9 0 U1 1 U2 2 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JUL PY 2004 VL 49 IS 3 BP 350 EP 356 PG 7 WC Engineering, Aerospace SC Engineering GA 844EJ UT WOS:000223139900010 ER PT J AU Cheng, AN Xu, KM Golaz, JC AF Cheng, AN Xu, KM Golaz, JC TI The liquid water oscillation in Modeling boundary layer cumuli with third-order turbulence closure models SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID PDF-BASED MODEL; EXPLICIT SIMULATION; PART I; CLOUDS; ENSEMBLES; PARAMETERIZATION; CONVECTION AB A hierarchy of third-order turbulence closure models are used to simulate boundary layer cumuli in this study. An unrealistically strong liquid water oscillation (LWO) is found in the fully prognostic model, which predicts all third moments. The LWO propagates from cloud base to cloud top with a speed of 1 m s(-1). The period of the oscillation is about 1000 s. Liquid water buoyancy (LWB) terms in the third-moment equations contribute to the LWO. The LWO mainly affects the vertical profiles of cloud fraction, mean liquid water mixing ratio, and the fluxes of liquid water potential temperature and total water, but has less impact on the vertical profiles of other second and third moments. In order to minimize the LWO, a moderately large diffusion coefficient and a large turbulent dissipation at its originating level are needed. However, this approach distorts the vertical distributions of cloud fraction and liquid water mixing ratio. A better approach is to parameterize LWB more reasonably. A minimally prognostic model, which diagnoses all third moments except for the vertical velocity, is shown to produce better results, compared to a fully prognostic model. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. USN, Res Lab, Natl Res Council, Monterey, CA USA. RP Cheng, AN (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. EM a.cheng@larc.nasa.gov RI Xu, Kuan-Man/B-7557-2013; Golaz, Jean-Christophe/D-5007-2014 OI Xu, Kuan-Man/0000-0001-7851-2629; Golaz, Jean-Christophe/0000-0003-1616-5435 NR 21 TC 15 Z9 16 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD JUL PY 2004 VL 61 IS 13 BP 1621 EP 1629 DI 10.1175/1520-0469(2004)061<1621:TLWOIM>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 835CV UT WOS:000222458500011 ER PT J AU Alterovitz, SA Mueller, CH Croke, ET AF Alterovitz, SA Mueller, CH Croke, ET TI High mobility SiGe/Si transistor structures on sapphire substrates using ion implantation SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID SILICON-ON-SAPPHIRE; ELECTRON-MOBILITY; STRAINED-SI; N-MODFET; HETEROSTRUCTURES; TECHNOLOGY; MODEL; INDUCTORS; SI/SIGE; ALLOYS AB We report the fabrication of high mobility n-type SiGe/Si transistor structures on sapphire substrates by ion implanting phosphorus ions into strained 10-nm-thick silicon channels. The strained Si channels were sandwiched between Si0.7Ge0.3 layers, which, in turn, were deposited on Si0.7Ge0.3 virtual substrates and graded SiGe buffer layers. After the molecular beam epitaxy film growth process was completed, donors were introduced and activated using ion implantation and postannealing processes. Microstructural characterization of the buffer layer, virtual substrate, and electron conduction structure using high resolution x-ray diffraction, cross-sectional transmission electron microscopy, atomic force microscopy, and secondary ion mass spectroscopy are reported. Room temperature electron mobilities up to 900 cm(2)/V s at a carrier density of 1.3 x 10(12) cm(-2) were measured. Electron concentration appears to be the key factor that determines mobility, with the highest mobility observed for electron densities in the 1 - 2 x 10(12) cm(-2) range. (C) 2004 American Vacuum Society. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Analex Corp, Cleveland, OH 44135 USA. HRL Labs LLC, Malibu, CA USA. RP Alterovitz, SA (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM samuel.a.alterovitz@nasa.gov NR 31 TC 3 Z9 3 U1 0 U2 1 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 2004 VL 22 IS 4 BP 1776 EP 1783 DI 10.1116/1.1763891 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 854TD UT WOS:000223925300028 ER PT J AU Fitzgerald, W Sylwester, AW Grivel, JC Lifson, JD Margolis, LB AF Fitzgerald, W Sylwester, AW Grivel, JC Lifson, JD Margolis, LB TI Noninfectious X4 but not R5 human immunodeficiency virus type 1 virions inhibit humoral immune responses in human lymphoid tissue ex vivo SO JOURNAL OF VIROLOGY LA English DT Article ID HIV-INFECTED INDIVIDUALS; B-CELL ACTIVATION; ACQUIRED-IMMUNODEFICIENCY; DENDRITIC CELLS; T-CELLS; HOMOSEXUAL MEN; ANTIRETROVIRAL THERAPY; ENVELOPE GLYCOPROTEINS; BIOLOGICAL PHENOTYPE; ANTIBODY-RESPONSES AB Ex vivo human immunodeficiency virus type 1 (HIV-1) infection of human lymphoid tissue recapitulates some aspects of in vivo HIV-1 infection, including a severe depletion of CD4(+) T cells and suppression of humoral immune responses to recall antigens or to polyclonal stimuli. These effects are induced by infection with X4 HIV-1 variants, whereas infection with R5 variants results in only mild depletion of CD4(+) T cells and no suppression of immune responses. To study the mechanisms of suppression of immune responses in this ex vivo system, we used aldrithiol-2 (AT-2)-inactivated virions that have functional envelope glycoproteins but are not infectious and do not deplete CD4(+) T cells in human lymphoid tissues ex vivo. Nevertheless, AT-2-inactivated X4 (but not R5) HIV-1 virions, even with only a brief exposure, inhibit antibody responses in human lymphoid tissue ex vivo, similarly to infectious virus. This phenomenon is mediated by soluble immunosuppressive factor(s) secreted by tissue exposed to virus. C1 NICHHD, Lab Cellular & Mol Biophys, NIH, Bethesda, MD 20892 USA. NICHHD, NASA, Ctr 3 Dimens Tissue Culture, NIH, Bethesda, MD 20892 USA. SAIC Frederick Inc, AIDS Vaccine Program, Natl Canc Inst, Frederick, MD 21702 USA. RP Lifson, JD (reprint author), NICHHD, Lab Cellular & Mol Biophys, NIH, Bldg 10,Room 10D14,10 Ctr Dr, Bethesda, MD 20892 USA. EM lifson@ncifcrf.gov FU NCI NIH HHS [N01-CO-12400, N01CO12400] NR 57 TC 6 Z9 6 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0022-538X J9 J VIROL JI J. Virol. PD JUL PY 2004 VL 78 IS 13 BP 7061 EP 7068 DI 10.1128/JVI.78.13.7061-7068.2004 PG 8 WC Virology SC Virology GA 830WC UT WOS:000222153800038 PM 15194782 ER PT J AU Stothers, RB AF Stothers, RB TI Density of fallen ash after the eruption of Tambora in 1815 SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE volcanic eruption; volcanic ash; Tambora AB A reassessment of the ash density associated with the eruption of the volcano Tambora, Indonesia, in 1815 is presented by examining contemporary reports. This eruption produced the largest known ashfall in historical times. The density of the fallen ash at Makassar, about 380 km north of Tambora, can be safely stated to be 636 kg m(-3). Published by Elsevier B.V. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Stothers, RB (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM rstothers@giss.nasa.gov NR 12 TC 2 Z9 2 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL 1 PY 2004 VL 134 IS 4 BP 343 EP 345 DI 10.1016/j.jvolgeores.2003.03.010 PG 3 WC Geosciences, Multidisciplinary SC Geology GA 831LO UT WOS:000222196100005 ER PT J AU Tzou, HS Lee, HJ Arnold, SM AF Tzou, HS Lee, HJ Arnold, SM TI Smart materials, precision sensors/actuators, smart structures, and structronic systems SO MECHANICS OF ADVANCED MATERIALS AND STRUCTURES LA English DT Review ID PIEZOELECTRIC SHELL ACTUATORS; NONLINEAR PIEZOTHERMOELASTICITY; ELECTRORHEOLOGICAL FLUID; MULTIFIELD ACTUATIONS; SIGNAL ANALYSIS; CONICAL SHELLS; MODAL VOLTAGES; SENSOR; VIBRATIONS; COMPOSITE AB Many electroactive functional materials have been used in small- and microscale transducers and precision mechatronic control systems for years. It was not until the mid-1980s that scientists started integrating electroactive materials with large-scale structures as in situ sensors and/or actuators, thus introducing the concept of smart materials, smart structures, and structronic systems. This paper provides an overview of present smart materials and their sensor/actuator/structure applications. Fundamental multifield optomagnetopiezoelectric-thermoelastic behaviors and novel transducer technologies applied to complex multifield problems involving elastic, electric, temperature, magnetic, light, and other interactions are emphasized. Material histories, characteristics, material varieties, limitations, sensor/actuator/structure applications, and so forth of piezoelectrics, shape-memory materials, electro- and magnetostrictive materials, electro- and magnetorheological fluids, polyelectrolyte gels, superconductors, pyroelectrics, photostrictive materials, photoferroelectrics, magneto-optical materials, and so forth are thoroughly reviewed. C1 Univ Kentucky, Dept Mech Engn, Lexington, KY 40506 USA. NASA, Glenn Res Ctr, Struct Mech & Dynam Branch, Cleveland, OH USA. NASA, Glenn Res Ctr, Life Predict Branch, Cleveland, OH USA. RP Univ Kentucky, Dept Mech Engn, Lexington, KY 40506 USA. EM hstzou@engr.uky.edu NR 149 TC 65 Z9 66 U1 7 U2 69 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 1537-6494 EI 1537-6532 J9 MECH ADV MATER STRUC JI Mech. Adv. Mater. Struct. PD JUL-OCT PY 2004 VL 11 IS 4-5 BP 367 EP 393 DI 10.1080/15376490490451552 PG 27 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science; Mechanics GA 828AM UT WOS:000221944800004 ER PT J AU Saha, S Pachon, M Ghoshal, A Schulz, MJ AF Saha, S Pachon, M Ghoshal, A Schulz, MJ TI Finite element modeling and optimization to prevent wire breakage in electro-discharge machining SO MECHANICS RESEARCH COMMUNICATIONS LA English DT Article DE WEDM; thermomechanical; FEM model; optimization AB One of the most important problems in wire electrical discharge machining is related to wire breakage. This research develops a simple finite element model and a new approach to predict the thermal distribution in the wire fairly accurately. The model can be used to optimize the different parameters of the system to prevent wire breakage. At any instant of time, the spatial heat distribution profile of the wire can be mapped on the transient analysis of any point on the wire traversing through all the heat zones from the top spool to the bottom end. Based on this principle, the finite element model and optimization algorithm are used to determine that the heat generated is the critical variable responsible for wire breakage. The model successfully predicts the thermal distribution profile accurately for various wire materials, for increased wire velocity and for reduction in heat transfer coefficient. This simple model is a precursor of development for 3-D finite element models that can describe the cross-sectional wire erosion as the workpiece cutting progresses. The modeling may lead to the development of a smart electro-discharge machining system with a sensor and feedback control to increase the cutting speed and minimize breakage. (C) 2003 Elsevier Ltd. All rights reserved. C1 Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA. Lucent Corp, Miramar, FL 33027 USA. NASA, Langley Res Ctr, NRC, Nondestruct Evaluat Sci Branch, Hampton, VA 23665 USA. Univ Cincinnati, Dept Mech Engn, Cincinnati, OH 45221 USA. RP Ghoshal, A (reprint author), 9131 Town Ridge, Middletown, CT 06457 USA. EM sanjoy.saha@asu.edu; mpachon@lucent.com; anindo_ghoshal@yahoo.com; m.j.schulz@uc.edu NR 10 TC 10 Z9 12 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0093-6413 J9 MECH RES COMMUN JI Mech. Res. Commun. PD JUL-AUG PY 2004 VL 31 IS 4 BP 451 EP 463 DI 10.1016/j.mechrescom.2003.09.006 PG 13 WC Mechanics SC Mechanics GA 823AM UT WOS:000221582100009 ER PT J AU Zdziarski, AA Gierlinski, M Mikolajewska, J Wardzinski, G Smith, DM Harmon, BA Kitamoto, S AF Zdziarski, AA Gierlinski, M Mikolajewska, J Wardzinski, G Smith, DM Harmon, BA Kitamoto, S TI GX 339-4: the distance, state transitions, hysteresis and spectral correlations SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries : general; stars : individual : GX 339-4; X-rays : binaries; X-rays : stars ID X-RAY BINARIES; ADVECTION-DOMINATED ACCRETION; TRANSIENT SOURCE EXPERIMENT; BLACK-HOLE CANDIDATES; BROAD-BAND SPECTRUM; GX 339-4; CYGNUS X-1; GAMMA-RAY; THERMAL PLASMAS; LOW/HARD STATE AB We study the X-ray variability and distance of GX 339-4. We derive the distance of greater than or similar to7 kpc, based on a recent determination of the binary parameters. We study data from the All-Sky Monitor (ASM) aboard Ginga, the Burst and Transient Source Experiment aboard the Compton Gamma Ray Observatory, and the ASM, Proportional Counter Array and High-Energy Transient X-ray Experiment aboard the Rossi X-ray Timing Explorer (RXTE). From 1987 to 2004, GX 339 4 underwent similar to15 outbursts and went through all known states of black hole binaries. For the first time, we present the PCA data from the initial hard state of the outburst of 2004. We then study colour-colour and colour-flux correlations. In the hard state, there is a strong anticorrelation between the 1.5-5 and 3-12 keV spectral slopes, which we explain by thermal Comptonization of disc photons. There is also a softening of the spectrum above 3 keV with the increasing flux that becomes stronger with increasing energy up to similar to200 keV. This indicates an anticorrelation between the electron temperature and luminosity, explained by hot accretion models. In addition, we see a variable broad-band slope with a pivot at similar to200 keV. In the soft state, there is a high-energy tail with varying amplitude beyond a strong and variable blackbody component. We confirm the presence of pronounced hysteresis, with the hard-to-soft state transitions occurring at much higher (and variable) luminosities than the soft-to-hard transitions. We fitted the RXTE/ASM data with a model consisting of an outer accretion disc and a hot inner flow. State transitions are associated then with variations in the disc truncation radius, which we fitted as similar to6GM/c(2) in the soft state and several times that in the hard state. The disappearance of the inner disc takes place at a lower accretion rate than its initial appearance owing to the dependence of the transitions on the source history. We provide further evidence against the X-ray emission in the hard state being non-thermal synchrotron, and explain the observed radio-X-ray correlation by the jet power being correlated with the accretion power. C1 Centrum Astronm M Kopernika, PL-00716 Warsaw, Poland. Univ Durham, Dept Phys, Durham DH1 3LE, England. Jagiellonian Univ, Astron Observ, PL-30244 Krakow, Poland. Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Rikkyo Univ, Coll Sci, Dept Phys, Toshima Ku, Tokyo 1718501, Japan. RP Zdziarski, AA (reprint author), Centrum Astronm M Kopernika, Bartycka 18, PL-00716 Warsaw, Poland. EM aaz@camk.edu.pl OI Gierlinski, Marek/0000-0001-9149-3514 NR 75 TC 177 Z9 180 U1 0 U2 1 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUL 1 PY 2004 VL 351 IS 3 BP 791 EP 807 DI 10.1111/j.1365-2966.2004.07830.x PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 832IS UT WOS:000222261500011 ER PT J AU Chiriaco, M Chepfer, H Noel, V Delaval, A Haeffelin, M Dubuisson, P Yang, P AF Chiriaco, M Chepfer, H Noel, V Delaval, A Haeffelin, M Dubuisson, P Yang, P TI Improving retrievals of cirrus cloud particle size coupling lidar and three-channel radiometric techniques SO MONTHLY WEATHER REVIEW LA English DT Article ID AIRBORNE SIMULATOR IMAGERY; SOLAR RADIATIVE-TRANSFER; HEXAGONAL ICE CRYSTALS; MULTIPLE-SCATTERING; SINGLE-SCATTERING; MICROPHYSICAL PROPERTIES; OPTICAL-PROPERTIES; SUCCESS; PHASE; MODIS AB This study is intended to illustrate the potential advantage of combining lidar measurements and the split-window technique based on the infrared spectral information contained at the 8.65-, 11.15-, and 12.05-mum bands for inferring the microphysical properties of cirrus clouds. The lidar returns are employed to detect cirrus clouds. The optical properties of nonspherical ice crystals computed from the state-of-the-art scattering computational methods are used for the present forward radiative transfer simulation that fully accounts for both gaseous absorption and multiple scattering processes in the atmosphere. A combination of the radiances at the three infrared (IR) bands with lidar backscatter returns cannot uniquely specify the effective size of ice crystals because of its dependence on the particle aspect ratios. To avoid the shortcoming associated with a potential multivalued retrieval, lidar depolarization observation is used to constrain the specification of the particle aspect ratio in the retrieval implementation based on a precalculated lookup library. The present methodology for inferring the microphysical properties of cirrus clouds is implemented for nine cases by using the measurements from a 532-nm lidar located at the Palaiseau, France, ground-based site and the infrared spectral bands from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra platform. It is shown that the three IR wavelengths are quite complementary in constraining the retrieval of the particle size, leading to a significant advance in comparison with two-channel techniques, whereas the aspect ratio constraint due to lidar depolarization reduces the uncertainty of retrieved particle size by more than 20% for 70% of the cases and more than 65% for 40% of the cloud cases. C1 IPSL, Meteorol Dynam Lab, Palaiseau, France. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Elico, Wimereux, France. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX USA. RP Chiriaco, M (reprint author), Ecole Polytech, LMD, F-91128 Palaiseau, France. EM chiriaco@lmd.polytechnique.fr RI Yang, Ping/B-4590-2011; Noel, Vincent/C-3702-2013 OI Noel, Vincent/0000-0001-9494-0340 NR 52 TC 24 Z9 24 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 JUL PY 2004 VL 132 IS 7 BP 1684 EP 1700 DI 10.1175/1520-0493(2004)132<1684:IROCCP>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 837CA UT WOS:000222602900009 ER PT J AU McCaul, EW Buechler, DE Goodman, SJ Cammarata, M AF McCaul, EW Buechler, DE Goodman, SJ Cammarata, M TI Doppler radar and lightning network observations of a severe outbreak of tropical cyclone tornadoes SO MONTHLY WEATHER REVIEW LA English DT Article ID STORMS; ENVIRONMENTS; BOUNDARY; BUOYANCY AB Data from a single Weather Surveillance Radar-1988 Doppler (WSR-88D) and the National Lightning Detection Network are used to examine the characteristics of the convective storms that produced a severe tornado outbreak, including three tornadoes that reached F3 intensity, within Tropical Storm Beryl's remnants on 16 August 1994. Comparison of the radar data with reports of tornadoes suggests that only 13 cells produced the 29 tornadoes that were documented in Georgia and the Carolinas on that date. Six of these cells spawned multiple tornadoes, and the radar data confirm the presence of miniature supercells. One of the cells was identifiable on radar for 11 h, spawning tornadoes over a time period spanning approximately 6.5 h. Several other tornadic cells also exhibited great longevity, with cell lifetimes longer than ever previously documented in a landfalling tropical cyclone (TC) tornado event. This event is easily the most intense TC tornado outbreak yet documented with WSR-88Ds. Time-height analyses of the three strongest tornadic supercells are presented in order to document storm kinematic structure and to show how these storms appear at different ranges from a WSR-88D. In addition, cloud-to-ground (CG) lightning data are examined in Beryl's remnants. Although the tornadic cells were responsible for most of Beryl's CG lightning, their flash rates were only weak to moderate, and in all the tornadic storms the lightning flashes were almost entirely negative in polarity. A few of the single-tornado storms produced no detectable CG lightning at all. There is evidence that CG lightning rates decreased during the tornadoes, compared to 30-min periods before the tornadoes. A number of the storms spawned tornadoes just after producing their final CG lightning flashes. Contrary to the findings for flash rates, both peak currents and positive flash percentages were larger in Beryl's nontornadic storms than in the tornadic ones. C1 Univ Space Res Assoc, Huntsville, AL 35806 USA. Univ Alabama, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Natl Weather Serv, Columbia, SC USA. RP McCaul, EW (reprint author), Univ Space Res Assoc, 6700 Odyssey Dr,Suite 203, Huntsville, AL 35806 USA. EM mccaul@space.hsv.usra.edu NR 41 TC 21 Z9 21 U1 2 U2 4 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 2004 VL 132 IS 7 BP 1747 EP 1763 DI 10.1175/1520-0493(2004)132<1747:DRALNO>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 837CA UT WOS:000222602900012 ER PT J AU Ng, HT Han, J Yamada, T Nguyen, P Chen, YP Meyyappan, M AF Ng, HT Han, J Yamada, T Nguyen, P Chen, YP Meyyappan, M TI Single crystal nanowire vertical surround-gate field-effect transistor SO NANO LETTERS LA English DT Article ID THIN-FILM-TRANSISTOR; CARBON NANOTUBE; OXIDE NANOWIRE; GROWTH; ARRAYS AB Harnessing the potential of single crystal inorganic nanowires for practical advanced nanoscale applications requires not only reproducible synthesis of highly regular one-dimensional (1D) nanowire arrays directly on device platforms but also elegant device integration which retains structural integrity of the nanowires while significantly reducing or eliminating complex critical processing steps. Here we demonstrate a unique, direct, and bottom-up integration of a semiconductor 1D nanowire, using zinc oxide (ZnO) as an example, to obtain a vertical surround-gate field-effect transistor (VSG-FET). The vertical device structure and bottom-up integration reduce process complexity, compared to conventional top-down approaches. More significantly, scaling of the vertical channel length is lithographically independent and decoupled from the device packing density. A bottom electrical contact to the nanowire is uniquely provided by a heavily doped underlying lattice-match substrate. Based on the nanowire-integrated platform, both n- and p-channel VSG-FETs are fabricated. The vertical device architecture has the potential for use in tera-level ultrahigh-density nanoscale memory and logic devices. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Ng, HT (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM hng@mail.arc.nasa.gov RI 李, 府中/H-4357-2011; Yamada, Toshishige/E-7834-2012 OI Yamada, Toshishige/0000-0001-7145-9212 NR 25 TC 493 Z9 499 U1 20 U2 209 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 EI 1530-6992 J9 NANO LETT JI Nano Lett. PD JUL PY 2004 VL 4 IS 7 BP 1247 EP 1252 DI 10.1021/nl049461z PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 839CX UT WOS:000222762000015 ER PT J AU Ye, Q Cassell, AM Liu, HB Chao, KJ Han, J Meyyappan, M AF Ye, Q Cassell, AM Liu, HB Chao, KJ Han, J Meyyappan, M TI Large-scale fabrication of carbon nanotube probe tips for atomic force microscopy critical dimension Imaging applications SO NANO LETTERS LA English DT Article ID SCANNING PROBE; LATERAL RESOLUTION; DIRECT GROWTH; DEVICES AB We report an innovative approach that combines nanopatterning and nanomaterials synthesis with traditional silicon micromachining technologies for large-scale fabrication of carbon nanotube (CNT) probe tips for atomic force microscopy imaging applications. Our batch fabrication process has produced 244 CNT probe tips per 4-in. wafer with control over the CNT location, diameter, length, orientation, and crystalline morphology. CNT probe tips with diameters ranging between 40 and 80 nm and lengths between 2 and 6 pm are found to be functional probe tips with no need for shortening. This reliable and true bottom-up wafer scale integration and fabrication process provides a new class of high performance nanoprobes. Preliminary AFM imaging results show that the CNT probe tips are strong, wear-resistant, and capable of high-resolution and critical-dimension imaging. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Integrated Nanosyst Inc, Moffett Field, CA 94035 USA. Charles Evans & Associates, Sunnyvale, CA 94086 USA. RP Ye, Q (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM qye@mail.arc.nasa.gov NR 27 TC 83 Z9 85 U1 3 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD JUL PY 2004 VL 4 IS 7 BP 1301 EP 1308 DI 10.1021/nl049341r PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 839CX UT WOS:000222762000025 ER PT J AU Myung, NV Lim, J Fleurial, JP Yun, M West, W Choi, D AF Myung, NV Lim, J Fleurial, JP Yun, M West, W Choi, D TI Alumina nanotemplate fabrication on silicon substrate SO NANOTECHNOLOGY LA English DT Article ID ANODIC ALUMINA; NANOHOLE ARRAY; POROUS ALUMINA; TEMPLATE; OXIDE AB Alumina nanotemplates integrated on silicon substrate with pore diameters of 12-100 nm were prepared by galvanostatic (constant current) anodization. High current density (e.g. 100 mA cm(-2)) promoted a highly ordered hexagonal pore structure with fast formation rate independent of anodizing solution. Alumina formation rates of 2000 and 1000 nm min(-1) were achieved at current densities of 100 and 50 mA cm(-2), respectively. These rates were approximately two orders of magnitude greater than other reports in the literature. Different electrolytes of sulfuric acid (1.8-7.2 M), oxalic acid (0.3 M) and mixed solutions of sulfuric and oxalic acids were evaluated as anodizing solutions. At fixed current density, sulfuric acid promoted smaller pore diameter with lower porosity than mixed acids and oxalic acid. The I-V characteristics of aluminium anodization show the measured voltages at given current densities strongly depend on solution composition, operating temperature, and bath agitation. The pore diameter of the silicon-integrated alumina nanotemplate varied linearly with measured voltage with a slope of 2.1 nm V-1, which is slightly smaller than reported data. C1 Univ Calif Riverside, Dept Environm Chem & Engn, Riverside, CA 92521 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Myung, NV (reprint author), Univ Calif Riverside, Dept Environm Chem & Engn, Bourns Hall B353,900 Univ Ave, Riverside, CA 92521 USA. EM myung@engr.ucr.edu RI Choi, Daniel/A-8181-2017 NR 18 TC 40 Z9 40 U1 1 U2 15 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD JUL PY 2004 VL 15 IS 7 BP 833 EP 838 AR PII s0957-4484(04)70268-8 DI 10.1088/0957-4484/15/7/021 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 842TA UT WOS:000223025900030 ER PT J AU Snyder, GJ Christensen, M Nishibori, E Caillat, T Iversen, BB AF Snyder, GJ Christensen, M Nishibori, E Caillat, T Iversen, BB TI Disordered zinc in Zn4Sb3 with phonon-glass and electron-crystal thermoelectric properties SO NATURE MATERIALS LA English DT Article ID CHARGE-DENSITY; PHASES AB By converting waste heat into electricity, thermoelectric generators could be an important part of the solution to today's energy challenges. The compound Zn4Sb3 is one of the most efficient thermoelectric materials known. Its high efficiency results from an extraordinarily low thermal conductivity in conjunction with the electronic structure of a heavily doped semiconductor. Previous structural studies have been unable to explain this unusual combination of properties. Here, we show through a comprehensive structural analysis using single-crystal X-ray and powder-synchrotron-radiation diffraction methods, that both the electronic and thermal properties of Zn4Sb3 can be understood in terms of unique structural features that have been previously overlooked. The identification of Sb3- ions and Sb-2(4-) dimers reveals that Zn4Sb3 is a valence semiconductor with the ideal stoichiometry Zn13Sb10. In addition, the structure contains significant disorder, with zinc atoms distributed over multiple positions. The discovery of glass-like interstitial sites uncovers a highly effective mechanism for reducing thermal conductivity. Thus Zn4Sb3 is in many ways an ideal 'phonon glass, electron crystal' thermoelectric material. C1 CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Aarhus Univ, Dept Chem, DK-8000 Aarhus, Denmark. Nagoya Univ, Dept Appl Phys, Nagoya, Aichi 4648603, Japan. RP Snyder, GJ (reprint author), CALTECH, 1200 E Calif Blvd, Pasadena, CA 91125 USA. EM jsnyder@caltech.edu RI Snyder, G. Jeffrey/E-4453-2011; Snyder, G/I-2263-2015 OI Snyder, G. Jeffrey/0000-0003-1414-8682; NR 26 TC 408 Z9 417 U1 28 U2 217 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1476-1122 J9 NAT MATER JI Nat. Mater. PD JUL PY 2004 VL 3 IS 7 BP 458 EP 463 DI 10.1038/nmat1154 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 834CL UT WOS:000222389100014 PM 15220913 ER PT J AU Dyson, RW Hixon, R Nallasamy, M Sawyer, S AF Dyson, RW Hixon, R Nallasamy, M Sawyer, S TI Simulating nonlinear stator noise for active control SO NOISE CONTROL ENGINEERING JOURNAL LA English DT Article ID BOUNDARY-CONDITIONS; SOUND; CASCADE AB The intent of this work is to demonstrate that nonlinear effects on realistic geometries can be a tool for fan noise reduction. Noise produced from a rotating blade row's convected vortical gusts impinging upon a stationary blade row (stator) was simulated using novel high order numerical techniques. Results from this simulation indicate nonlinear resonance in a blade passage may be used to reduce turbofan engine noise by exciting high-frequency destructive modes with a more easily controlled low-frequency on-blade actuator. This technique of noise reduction is particularly attractive in a duct when cut-off modes are chosen as the base actuator frequency. A combination of large amplitude actuator produced cut-off modes with their corresponding nonlinear harmonic destructive interference patterns is a potential new area of active noise control research. (C) 2004 Institute of Noise Control Engineering. C1 NASA Glenn Res Ctr, Cleveland, OH USA. Univ Toledo, Toledo, OH 43606 USA. Univ Akron, Akron, OH 44325 USA. RP Dyson, RW (reprint author), NASA Glenn Res Ctr, Cleveland, OH USA. EM Rodger.W.Dyson@nasa.gov; dhixon@eng.utoledo.edu; Nallasamy@nasa.gov; ssawyer@uakron.edu NR 28 TC 0 Z9 0 U1 0 U2 0 PU INST NOISE CONTROL ENGINEERING PI AMES PA IOWA STATE UNIV, COLLEGE ENGINEERING, 212 MARSTON HALL, AMES, IA 50011-2152 USA SN 0736-2501 J9 NOISE CONTROL ENG J JI Noise Control Eng. J. PD JUL-AUG PY 2004 VL 52 IS 4 BP 164 EP 168 DI 10.3397/1.2839746 PG 5 WC Acoustics; Engineering, Multidisciplinary SC Acoustics; Engineering GA 876SS UT WOS:000225518400002 ER PT J AU Refaat, TF Abedin, MN Sulima, OV Ismail, S Singh, UN AF Refaat, TF Abedin, MN Sulima, OV Ismail, S Singh, UN TI AlGaAsSb/InGaAsSb phototransistors for 2-mu m remote sensing applications SO OPTICAL ENGINEERING LA English DT Article DE phototransistor; 2 mu m detector; CO2 profiling; atmospheric sensing; lidar; differential absorption lidar AB Two-micron detectors are critical for atmospheric CO., profiling using the lidar technique. InGaAs and HgCdTe detectors are commercially available for this wavelength but they lack sufficient gain, which limits their detectivity. The characterization results of a novel AlGaAsSb/InGaAsSb phototransistor for 2-mum application are reported. The device was developed by AstroPower, Inc. for NASA Langley Research Center. Spectral response measurements showed the highest responsivity in a 1.9- to 2.1-mum region with a maximum value of 2650 A/W at 2 mum. A 2-mum cletectivity of 3.9 X 10(11) cm Hz(1/2)/W was obtained, which corresponds to noise equivalent power of 4.6 x 10(-14) W/Hz(1/2) (C) 2004 Society of Photo-Optical Instrumentation Engineers. C1 NASA, Langley Res Ctr, Sci & Technol Corp, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Laser & Electroopt Branch, Hampton, VA 23681 USA. Astropower Inc, Newark, DE 19716 USA. NASA, Langley Res Ctr, Chem & Dynam Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Syst Engn Competency, Hampton, VA 23681 USA. RP Refaat, TF (reprint author), NASA, Langley Res Ctr, Sci & Technol Corp, 5 Dryden St,MS 468, Hampton, VA 23681 USA. EM fn.t.f.refaat@larc.nasa.gov NR 7 TC 21 Z9 21 U1 0 U2 3 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD JUL PY 2004 VL 43 IS 7 BP 1647 EP 1650 DI 10.1117/1.1760085 PG 4 WC Optics SC Optics GA 837NC UT WOS:000222641200024 ER PT J AU Gabriel, AK AF Gabriel, AK TI Unification of radar phenomena as spacetime curvature: prediction and observation of an affine-phase effect SO OPTICS LETTERS LA English DT Article ID INTERFEROMETRY AB The many properties of radar echoes and other radiative systems were recently described by Gabriel W. Opt. Soc. Am. A 19, 946 (2002)] as lower-dimensional projections of simple forms in special relativity. A broader treatment including coherent phenomena is summarized, in which the phase properties of radar images and interferograms are also shown to have a simple unified structure. Their apparent complexity is a result of projection onto the lower dimension(s) of the observation. A predicted now property, locally scalable (affine) phase, is observed in a radar interferogram. (C) 2004 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gabriel, AK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM agabriel@socal.rr.com NR 8 TC 1 Z9 1 U1 0 U2 0 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 JUL 1 PY 2004 VL 29 IS 13 BP 1533 EP 1535 DI 10.1364/OL.29.001533 PG 3 WC Optics SC Optics GA 830OV UT WOS:000222133100033 PM 15259737 ER PT J AU Chen, XS Di Bartolo, B Barnes, NP Walsh, BM AF Chen, XS Di Bartolo, B Barnes, NP Walsh, BM TI Thermal tuning and broadening of the spectral lines of trivalent neodymium in laser crystals SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article AB This work reports a large number of experimental investigations of the effects of temperature on the sharp spectral lines of the trivalent neodymium ion in laser-type crystals. The available theory that explains these effects in simple luminescence systems is applied to the cases examined when possible. Some general conclusions regarding the thermal effects on the systems examined are presented. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. C1 Wheaton Coll, Dept Phys, Norton, MA 02766 USA. Boston Coll, Dept Phys, Chestnut Hill, MA 02167 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Chen, XS (reprint author), Wheaton Coll, Dept Phys, Norton, MA 02766 USA. EM xchen@wheatonma.edu NR 12 TC 9 Z9 9 U1 0 U2 2 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD JUL PY 2004 VL 241 IS 8 BP 1957 EP 1976 DI 10.1002/pssb.200302021 PG 20 WC Physics, Condensed Matter SC Physics GA 837HB UT WOS:000222618200024 ER PT J AU Krolak, A Tinto, M Vallisneri, M AF Krolak, A Tinto, M Vallisneri, M TI Optimal filtering of the LISA data SO PHYSICAL REVIEW D LA English DT Article ID TIME-DELAY INTERFEROMETRY; GRAVITATIONAL-WAVES; BINARIES; ANTENNA AB The LISA time-delay-interferometry responses to a gravitational wave signal are rewritten in a form that accounts for the motion of the LISA constellation around the Sun; the responses are given in closed analytic forms valid for any frequency in the band accessible to LISA. We then present a complete procedure, based on the principle of maximum likelihood, to search for stellar-mass binary systems in the LISA data. We define the required optimal filters, the amplitude-maximized detection statistic (analogous to the F statistic used in pulsar searches with ground-based interferometers), and discuss the false-alarm and detection probabilities. We then test the procedure in numerical simulations of gravitational-wave detection. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Polish Acad Sci, Inst Math, Warsaw, Poland. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM A.krolak@impan.gov.pl; Massimo.Tinto@jpl.nasa.gov; Michele.Vallisneri@jpl.nasa.gov NR 37 TC 49 Z9 49 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUL PY 2004 VL 70 IS 2 AR 022003 DI 10.1103/PhysRevD.70.022003 PG 24 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 845HQ UT WOS:000223233400003 ER PT J AU Bakunov, MI Bodrov, SB Maslov, AV Sergeev, AM AF Bakunov, MI Bodrov, SB Maslov, AV Sergeev, AM TI Two-dimensional theory of Cherenkov radiation from short laser pulses in a magnetized plasma SO PHYSICAL REVIEW E LA English DT Article ID OPTICAL PULSES; WAKES AB The Cherenkov wakes excited by intense laser drivers in a perpendicularly magnetized plasma are a potential source of high-power terahertz radiation. We present a two-dimensional (2D) theory of the emission of magnetized wakes excited by a short laser pulse. The 2D model reveals the important role of the transverse size of the laser pulse missed in previous simple one-dimensional estimations of the radiation. We derived expressions for the radiated fields and for the angular/frequency distribution of the radiated energy. Beats in the radiation pattern behind the moving pulse are predicted and explained. For the interpretation of existing experimental results, the time dependence of the energy flux parallel and perpendicular to the laser path is examined. C1 Univ Nizhny Novgorod, Dept Radiophys, Nizhnii Novgorod 603950, Russia. RAS, Inst Appl Phys, Nizhnii Novgorod 603950, Russia. NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. RP Bakunov, MI (reprint author), Univ Nizhny Novgorod, Dept Radiophys, Nizhnii Novgorod 603950, Russia. RI Maslov, Alexey/E-5158-2011; Bodrov, Sergey/D-1962-2012; Bakunov, Michael/E-2875-2017; Sergeev, Alexander/F-3027-2017 OI Maslov, Alexey/0000-0002-7835-2474; Bakunov, Michael/0000-0002-4209-1372; NR 18 TC 20 Z9 22 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD JUL PY 2004 VL 70 IS 1 AR 016401 DI 10.1103/PhysRevE.70.016401 PN 2 PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 844CV UT WOS:000223135800063 PM 15324172 ER PT J AU Shebalin, JV AF Shebalin, JV TI Stormer regions for axisymmetric magnetic multipole fields SO PHYSICS OF PLASMAS LA English DT Article ID CHARGED-PARTICLE AB The motion of a single charged particle in the space outside of a compact region of steady currents is investigated. The charged particle is assumed to produce negligible electromagnetic radiation, so that its energy is conserved. The source of the magnetic field is represented as a point multipole. After a general description, attention is focused on magnetic fields with axial symmetry. Lagrangian dynamical theory is utilized to identify constants of the motion as well as the equations of motion themselves. In particular, the energy and the canonical angular momentum conjugate to the azimuthal angle are conserved for axial symmetry. Following the precedent of some authors, and for brevity, the constant canonical angular momentum conjugate to the azimuthal angle will be called Stormer's integral. In the present work, the magnetic vector potential equivalent to a given spherical harmonic scalar potential is also found. The qualitative method of Stormer is then used to examine charged particle motion in axisymmetric multipole fields of all orders, and while the treatment is fully relativistic, it also encompasses nonrelativistic motion. This qualitative method divides the configuration space of the charged particle into sets in which motion is either forbidden or allowed, i.e., it permits a topological examination of dynamical motion. The results obtained here allow for the determination of trapped-particle regions around those astrophysical objects and spacecraft plasma propulsion systems that have an associated axisymmetric magnetic field described by a multipole of given order. (C) 2004 American Institute of Physics. C1 NASA, Adv Space Prop Lab, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Shebalin, JV (reprint author), NASA, Adv Space Prop Lab, Lyndon B Johnson Space Ctr, Mail Code ASPL, Houston, TX 77058 USA. NR 13 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 2004 VL 11 IS 7 BP 3472 EP 3482 DI 10.1063/1.1752931 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 830AR UT WOS:000222094500018 ER PT J AU Korth, H Anderson, BJ Acuna, MH Slavin, JA Tsyganenko, NA Solomon, SC McNutt, RL AF Korth, H Anderson, BJ Acuna, MH Slavin, JA Tsyganenko, NA Solomon, SC McNutt, RL TI Determination of the properties of Mercury's magnetic field by the MESSENGER mission SO PLANETARY AND SPACE SCIENCE LA English DT Article DE mercury; MESSENGER mission; magnetic field; multiple inversion ID THERMOELECTRIC DYNAMO; CRUSTAL REMANENCE; MAGNETOSPHERE; MAGNETOPAUSE; DISTANCE; CURRENTS; MOMENT; SHELL AB The MESSENGER mission to Mercury, to be launched in 2004. will provide an opportunity to characterize Mercury's internal magnetic field during an orbital phase lasting one Earth year. To test the ability to determine the planetary dipole and higher-order moments from measurements by the spacecraft's fluxgate magnetometer, We simulate the observations along the spacecraft trajectory and recover the internal field characteristics from the stimulated observations. The magnetic field inside Mercury's magnetosphere is assumed to consist of an intrinsic multipole component and an external contribution due to magnetospheric current systems described by a modified Tsyganenko 96 model. Under the axis-centered-dipole approximation without correction for the external field the moment strength is overestimated by similar to4% for a simulated dipole moment of 300 nTR(M)(3), and the error depends strongly on the magnitude of the simulated moment. rising as the moment decreases. Correcting for the external field contributions can reduce the error in the dipole term to a lower limit of similar to1-2% without a solar wind monitor. Dipole and quadrupole terms, although highly correlated, are then distinguishable at the level equivalent to ail error in the position of an offset dipole of a few tens of kilometers. Knowledge of the external magnetic field is therefore the primary limiting factor in extracting reliable knowledge of the structure of Mercury's magnetic field from the MESSENGER observations. (C) 2004 Elsevier Ltd. All rights reserved. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. RP Korth, H (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. EM haje.korth@jhuapl.edu RI Anderson, Brian/I-8615-2012; Tsyganenko, Nikolai/J-7377-2012; Slavin, James/H-3170-2012; McNutt, Ralph/E-8006-2010 OI Tsyganenko, Nikolai/0000-0002-5938-1579; Slavin, James/0000-0002-9206-724X; McNutt, Ralph/0000-0002-4722-9166 NR 41 TC 42 Z9 42 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JUL PY 2004 VL 52 IS 8 BP 733 EP 746 DI 10.1016/j.pss.2003.12.008 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 822RJ UT WOS:000221557300008 ER PT J AU Hinkley, JA Dezern, JF Feuz, L Klinedinst, D AF Hinkley, JA Dezern, JF Feuz, L Klinedinst, D TI Uniaxial stretching of poly(keto-ether-imide) films SO POLYMER ENGINEERING AND SCIENCE LA English DT Article ID THERMOPLASTIC POLYIMIDE; LARC-CPI; CRYSTALLIZATION; POLYMER; BEHAVIOR; ETHER AB Narrow strips of various fully imidized polyimide films were stretched under constant load either isothermally or during a temperature ramp. The effects of process variables (load and temperature) on modulus, failure strain, and tensile strength of the stretched films were characterized and room temperature moduli of up to 16 GPa were documented. Several materials that undergo strain-induced crystallization were identified as candidates for further property optimization. (C) 2004 Society of Plastics Engineers. C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. Swiss Fed Inst Technol, DMATL, CH-8952 Schlieren, Switzerland. Norfolk State Univ, Norfolk, VA 23504 USA. RP Hinkley, JA (reprint author), NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. NR 30 TC 5 Z9 5 U1 1 U2 6 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0032-3888 J9 POLYM ENG SCI JI Polym. Eng. Sci. PD JUL PY 2004 VL 44 IS 7 BP 1360 EP 1367 DI 10.1002/pen.20131 PG 8 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 845OJ UT WOS:000223253900019 ER PT J AU Lyster, PM Cohn, SE Zhang, BL Chang, LP Menard, R Olson, K Renka, R AF Lyster, PM Cohn, SE Zhang, BL Chang, LP Menard, R Olson, K Renka, R TI A Lagrangian trajectory filter for constituent data assimilation SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE characteristics; estimation theory; Kalman filter ID ATMOSPHERIC DATA ASSIMILATION; KALMAN FILTER; DYNAMICS; SPHERE; ERROR; TRANSPORT; ADVECTION; SURFACE; SURGERY; SCHEME AB We have developed a new numerical algorithm, the Lagrangian filter, for solving the Kalman filter equations for assimilation of constituent observations directly on trajectories that propagate with the flow. This is a finite-dimensional approximation of the solution of the state estimation problem by characteristics, and may be thought of as an extension of methods such as trajectory mapping. The Lagrangian filter provides a natural framework for the study and solution of the constituent data assimilation problem because of the conservative properties of the state and its estimation-error variance and covariance along trajectories. Considerable insight into the behaviour of the filter is gained as a result of these properties. The Lagrangian filter also requires significantly fewer floating point operations than the Eulerian Kalman filter because of its simple error covariance propagation step. We implemented it for two-dimensional flow on isentropes in the stratosphere and assimilated methane observations from the Upper Atmosphere Research Satellite. Results are validated against those of the Eulerian filter. C1 NASA, Goddard Space Flight Ctr, GMAO, Greenbelt, MD 20771 USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. Sci Applicat Int Corp, Calverton, MD USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Univ N Texas, Dept Comp Sci & Engn, Denton, TX 76203 USA. RP Lyster, PM (reprint author), NASA, Goddard Space Flight Ctr, GMAO, Code 900-3, Greenbelt, MD 20771 USA. EM lysterp@mail.nih.gov RI Cohn, Stephen/K-1954-2012 OI Cohn, Stephen/0000-0001-8506-9354 NR 26 TC 3 Z9 3 U1 0 U2 0 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JUL PY 2004 VL 130 IS 601 BP 2315 EP 2334 DI 10.1256/qj.02.234 PN B PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 860HD UT WOS:000224332200018 ER PT J AU Otvos, EG Giardino, MJ AF Otvos, EG Giardino, MJ TI Interlinked barrier chain and delta lobe development, northern Gulf of Mexico SO SEDIMENTARY GEOLOGY LA English DT Article DE barrier islands; shoal platform; barrier stranding; hydrocarbon reservoirs; luminescence dating; delta growth and recession; Mississippi delta; Gulf coast AB A wealth of new data provides a well-constrained chronology of mid- to late Holocene coastal development in the Louisiana-Mississippi borderland that may also be utilized in a globally applicable sedimentation model. Barrier sand and deltaic mud sequences illustrate a process by which potential ground water and hydrocarbon reservoir rocks accumulated unusually rapidly and were preserved. Set against decelerating Holocene sea-level rise and locally variable subsidence rates, the study provides an example of the interplay between an emerging, prograding, and partially stranded barrier island chain, a sizable estuary, and several extensive delta lobes. Utilizing microfossil fauna-based depositional facies information and archaeological data, absolute dates helped to reconstruct the history of the Alabama-Louisiana barrier chain and deltas between ca. 5.7 and ca. 1.5 C-14 ka BP. Protected by the substantial dune cover that prevented island submersion, the regional eustastic transgression paradoxically was synchronous with significant progradational barrier and deltaic regression. The earliest barrier islands emerged ca. 4.6-4.4 C-14 ka BP (ca. 5.7-5.0 cal years) when sea level stood at ca. - 1.0 to - 1.5 m. These islands isolated Mississippi Sound from the greater Gulf of Mexico. The absence of a lagoonal-inshore sediment interval beneath the islands and the 3-15 m thick basal nearshore marine muddy-sandy unit that blankets the Pleistocene surface refutes the transgressive history of barrier initiation. The islands aggraded on a 3.0-16.5 m thick fine sandy shallow-marine regressive platform lithosome that, in turn, overlies a transgressive muddy-sandy nearshore marine lower sediment interval. Avulsion of the Mississippi River had abruptly reduced nearshore salinities by ca. 3.9-3.7 ka C-14 BP. Renewed Mississippi delta growth induced rapid aggradation and progradation on the opposite Pearl River delta-mainland shore as well. Gulf influences have rapidly diminished in areas so affected. A new absolute chronology of the Mississippi-St. Bernard delta lobes constrains these events. Delta growth and mainland progradation first isolated, then severely constricted the Lake Borgne embayment. Accompanied by ongoing subsidence, the western barriers were stranded, then buried. Shoaling, related to St. Bernard delta progradation, interfered with westward littoral drift to maintain Cat Island. Archaeology provided important supplementary data for dating environmental changes. Refuting earlier suggestions that Native colonization rapidly followed delta complex formation, the earliest known Indian sites postdated the start of the associated St. Bernard delta lobe by 1.9-3.1 C-14 ka. (C) 2004 Published by Elsevier B.V. C1 Univ So Mississippi, Dept Coastal Sci, Ocean Springs, MS 39566 USA. NASA, Commercial Appl Directorate Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. RP Otvos, EG (reprint author), Univ So Mississippi, Dept Coastal Sci, 703 E Beach Blvd, Ocean Springs, MS 39566 USA. EM ervin.otvos@usm.edu NR 42 TC 27 Z9 27 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0037-0738 J9 SEDIMENT GEOL JI Sediment. Geol. PD JUL 1 PY 2004 VL 169 IS 1-2 BP 47 EP 73 DI 10.1016/j.sedgeo.2004.04.008 PG 27 WC Geology SC Geology GA 842QW UT WOS:000223020100004 ER PT J AU Malanushenko, OV Jones, HP AF Malanushenko, OV Jones, HP TI Analysis of He I 1083 nm imaging spectroscopy using a spectral standard SO SOLAR PHYSICS LA English DT Article ID POLAR CORONAL HOLES; TRANSITION REGION; SOLAR CORONA; HELIUM; LINES AB We develop a technique for the analysis of He I 1083 nm spectra which addresses several difficulties through determination of a continuum background by comparison with a well-calibrated standard and through removal of nearby solar and telluric blends by differential comparison to an average spectrum. The method is compared with earlier analysis of imaging spectroscopy obtained at the National Solar Observatory/Kitt Peak Vacuum Telescope (NSO/KPVT) with the NASA/NSO Spectromagnetograph (SPM). We examine distributions of Doppler velocity and line width as a function of central intensity for an active region, filament, quiet Sun, and coronal hole. For our example, we find that line widths and central intensity are oppositely correlated in a coronal hole and quiet Sun. Line widths are comparable to the quiet Sun in the active region, are systematically lower in the filament, and extend to higher values in the coronal hole. Outward velocities of approximate to 2-4 km s(-1) are typically observed in the coronal hole. The sensitivity of these results to analysis technique is discussed. C1 Natl Solar Observ, Tucson, AZ 85726 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Malanushenko, OV (reprint author), Natl Solar Observ, POB 26732, Tucson, AZ 85726 USA. EM elena@noao.edu NR 26 TC 7 Z9 7 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JUL PY 2004 VL 222 IS 1 BP 43 EP 60 DI 10.1023/B:SOLA.0000036873.75777.33 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 843OP UT WOS:000223093800004 ER PT J AU Mitrofanov, IG Litvak, ML Kozyrev, AS Sanin, AB Tret'yakov, VI Grin'kov, VY Boynton, WV Shinohara, C Hamara, D Saunders, RS AF Mitrofanov, IG Litvak, ML Kozyrev, AS Sanin, AB Tret'yakov, VI Grin'kov, VY Boynton, WV Shinohara, C Hamara, D Saunders, RS TI Soil water content on Mars as estimated from neutron measurements by the HEND instrument onboard the 2001 Mars Odyssey spacecraft SO SOLAR SYSTEM RESEARCH LA English DT Article ID RESIDUAL CO2 FROST; SUMMER TEMPERATURES; MARTIAN SOIL; NEAR-SURFACE; ICE; DETECTOR; HYDROGEN; SEARCH AB We present the results of 20 months of observations of Mars by the Russian HEND instrument onboard the NASA 2001 Mars Odyssey spacecraft. We show that there are two extended subpolar regions with a soil water content of several tens of percent in the northern and southern hemispheres of Mars. The southern subpolar region is well described by a two-layer model, according to which a soil with a water content of up to 55% by mass lies under a relatively dry soil with a water mass fraction of 2% and a thickness of 15-20 g/cm(2). The distribution of water in Martian regolith northern subpolar region is in good agreement with the homogeneous model and does not require invoking the more complex two-layer soil model. The water-ice content in the subsurface layer of the northern subpolar region reaches 53% by mass. We show that there are two regions with a relatively high water content near the Martian equator. These are Arabia Terra and the Medusae Fossae formation region southwest of Olympus Mons. In these regions, a lower layer with 9-10% of water by mass may underlie the upper layer of relatively dry material similar to30 g/cm(2) in thickness. The "moistest" spot near the equator is at about 30degrees E and 10degrees N. Its lower-layer soil may contain more than 16% of water by mass. C1 Russian Acad Sci, Inst Space Res, Moscow 117810, Russia. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. NASA Headquarters, Washington, DC 20514 USA. RP Mitrofanov, IG (reprint author), Russian Acad Sci, Inst Space Res, Profsoyuznaya Ul 84-32,GSP-7, Moscow 117810, Russia. NR 20 TC 44 Z9 44 U1 0 U2 3 PU MAIK NAUKA/INTERPERIODICA PI NEW YORK PA C/O KLUWER ACADEMIC-PLENUM PUBLISHERS, 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0038-0946 J9 SOLAR SYST RES+ JI Solar Syst. Res. PD JUL-AUG PY 2004 VL 38 IS 4 BP 253 EP 265 DI 10.1023/B:SOLS.0000037461.70809.45 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 849VW UT WOS:000223570500001 ER PT J AU Gelzer, C AF Gelzer, C TI Like sex with Gods: An unorthodox history of flying. SO TECHNOLOGY AND CULTURE LA English DT Book Review C1 NASA, Dryden Flight Res Ctr, Edwards AFB, CA USA. RP Gelzer, C (reprint author), NASA, Dryden Flight Res Ctr, Edwards AFB, CA USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4363 USA SN 0040-165X J9 TECHNOL CULT JI Technol. Cult. PD JUL PY 2004 VL 45 IS 3 BP 624 EP 625 DI 10.1353/tech.2004.0126 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 856YT UT WOS:000224082700011 ER PT J AU Bugos, GE AF Bugos, GE TI Chasing the silver bullet: US Air Force weapons development from Vietnam to desert storm. SO TECHNOLOGY AND CULTURE LA English DT Book Review C1 NASA, Prologue Grp, Moffett Field, CA USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bugos, GE (reprint author), NASA, Prologue Grp, Moffett Field, CA USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4363 USA SN 0040-165X J9 TECHNOL CULT JI Technol. Cult. PD JUL PY 2004 VL 45 IS 3 BP 630 EP 631 DI 10.1353/tech.2004.0113 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 856YT UT WOS:000224082700015 ER PT J AU Carls, MG Rice, SD Marty, GD Naydan, DK AF Carls, MG Rice, SD Marty, GD Naydan, DK TI Pink salmon spawning habitat is recovering a decade after the Exxon Valdez oil spill SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID PRINCE-WILLIAM-SOUND; WEATHERED CRUDE-OIL; ONCORHYNCHUS-GORBUSCHA; LIFE-HISTORY; FISH EMBRYOS; DAMAGE; SENSITIVITY; MORTALITY; INDUCTION; EXPOSURE AB Intertidal sediment surrounding many spawning streams for pink salmon Oncorhynchus gorbuscha in western Prince William Sound, Alaska, was contaminated by the Exxon Valdez oil spill in 1989. Biochemical and egg-dig evidence suggested that oil reduced the survival of pink salmon embryos for several years. Previous research also demonstrated that dissolved oil can be transferred to developing embryos from surrounding oiled sediment via drainage of interstitial water as a result of tidal cycling and hydraulic gradients. In this study, completed a decade after the spill, we sampled stream water for the presence of oil using passive membrane sampling devices, collected sediment and pink salmon eggs for hydrocarbon analysis, and examined alevins for induction of cytochrome P4501A (CYP1A). Polynuclear aromatic hydrocarbons (PAHs) consistent with Exxon Valdez oil were present in the water of one of six heavily impacted streams; total PAH concentrations in the stream were greatest in the lower intertidal zone. Similarly distributed total PAHs in a second stream suggested possible contamination. Oil was not detected in the remaining four streams. Induction of CYPIA in pink salmon alevins from the two contaminated streams was lowest in water above mean high tide and increased downstream. Because our samples were all selected from heavily oiled streams, we infer that most pink salmon spawning habitat either has recovered or is recovering. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. Univ Calif Davis, Sch Vet Med, Dept Anat Physiol & Cell Biol, Davis, CA 95616 USA. RP Carls, MG (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM mark.carls@noaa.gov NR 27 TC 9 Z9 9 U1 0 U2 21 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD JUL PY 2004 VL 133 IS 4 BP 834 EP 844 DI 10.1577/T03-125.1 PG 11 WC Fisheries SC Fisheries GA 838IY UT WOS:000222708100002 ER PT J AU DellaCorte, C AF DellaCorte, C TI Have you found your replacement yet? SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH USA. RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. EM cdellacorte@stle.org NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 TRIBOL LUBR TECHNOL JI Tribol. Lubr. Technol. PD JUL PY 2004 VL 60 IS 7 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 832XO UT WOS:000222301200002 ER PT J AU Cioc, S Keith, TG Dimofte, F Fleming, DP AF Cioc, S Keith, TG Dimofte, F Fleming, DP TI Calculation of the flow in high-speed gas bearings including inertia effects using the CE/SE method SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 58th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY APR 28-MAY 01, 2003 CL NEW YORK, NEW YORK SP Soc Tribologists & Lubricat Engineers DE hydrodynamic lubrication; inertia effects; gas lubrication ID TIME CONSERVATION ELEMENT; PLANE SLIDER BEARINGS; FLUID INERTIA; OPERATING CHARACTERISTICS; JOURNAL BEARINGS; EQUATIONS; FINITE AB In the classical Reynolds equation, inertia effects are neglected. Gas bearings working at very high speeds may encounter flow discontinuities (shock waves), which require the inclusion of inertia terms within the momentum equations. In order to solve the resulting system of equations, a numerical method capable of capturing flow discontinuities is necessary, and the space-time conservation element/solution element (CE/SE) is such a method. In addition, it does not incorporate any other assumptions or special numerical treatment. Results obtained using this method are compared with experimental data and theoretical results, as well as with results obtained by neglecting inertia effects. C1 Univ Toledo, Dept Mech Ind & Mfg Engn, Toledo, OH 43606 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Cioc, S (reprint author), Univ Toledo, Dept Mech Ind & Mfg Engn, 2801 W Bancroft St, Toledo, OH 43606 USA. NR 22 TC 2 Z9 2 U1 1 U2 2 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD JUL-SEP PY 2004 VL 47 IS 3 BP 402 EP 412 PG 11 WC Engineering, Mechanical SC Engineering GA 844MH UT WOS:000223161900012 ER PT J AU Li, L Warren, WH AF Li, L Warren, WH TI Path perception during rotation: influence of instructions, depth range, and dot density SO VISION RESEARCH LA English DT Article DE eye movement; heading; optic flow; self-motion ID EYE-MOVEMENTS; SELF-MOTION; OPTIC FLOW; RETINAL FLOW; INFORMATION; SUFFICIENCY; JUDGMENTS AB How do observers perceive their direction of self-motion when traveling on a straight path while their eyes are rotating? Our previous findings suggest that information from retinal flow and extra-retinal information about eye movements are each Sufficient to solve this problem for both perception and active control of self-motion [Vision Res. 40 (2000) 3873; Psych. Sci. 13 (2002) 485]. In this paper. using displays depicting translation with simulated eye rotation, we investigated how task variables Such as instructions, depth range. and dot density influenced the Visual system's reliance on retinal vs. extra-retinal information for path perception during, rotation. We found that path errors were small when observers expected to travel on a straight path or with neutral instructions. but errors increased markedly when observers expected to travel on a Curved path. Increasing depth range or dot density did not improve path judgments. We conclude that the expectation of the shape of ail upcoming path can influence the interpretation of the ambiguous retinal flow. A large depth range and dense motion parallax are not essential for accurate path perception during rotation, but reference objects and a large field of view appear to improve path judgments. (C) 2004 Elsevier Ltd. All rights reserved. C1 Brown Univ, Dept Cognit & Linguist Sci, Providence, RI 02912 USA. RP Li, L (reprint author), NASA, Ames Res Ctr, MS 262-2, Moffett Field, CA 94035 USA. EM lli@mail.arc.nasa.gov FU NEI NIH HHS [EY10923, R01 EY010923]; NIMH NIH HHS [K02 MH01353, K02 MH001353] NR 27 TC 23 Z9 23 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0042-6989 J9 VISION RES JI Vision Res. PD JUL PY 2004 VL 44 IS 16 BP 1879 EP 1889 DI 10.1016/j.visres.2004.03.008 PG 11 WC Neurosciences; Ophthalmology SC Neurosciences & Neurology; Ophthalmology GA 826WF UT WOS:000221859500005 PM 15145682 ER PT J AU Prina, M Bowman, RC Kulleck, JG AF Prina, M Bowman, RC Kulleck, JG TI Degradation study of ZrNiH1.5 for use as actuators in gas gap heat switches SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE hydrogen storage materials; X-ray diffraction; thermal analysis ID HYDRIDE PHASE GROWTH; INTERMETALLIC COMPOUNDS; HYDROGEN ABSORPTION; THERMODYNAMIC CHARACTERIZATION; DIFFUSION; SYSTEMS; GETTERS; STORAGE; ZRCO; ZRNI-H-2 AB ZrNi hydride has been assessed as reversible hydrogen storage material in actuators of gas gap heat switches for various applications including hydride compressors in closed-cycle Joule-Thomson (J-T) sorption cryocoolers. Three ZrNiH1.5 samples have been cycled between 280 and 450 K for more than 24,000 cycles to evaluate phase stability and durability of this hydride for conditions simulating device operation. Changes in the hydrogen absorption and desorption were evaluated by measuring the pressure and temperature dynamic relationship during each cycle and by powder X-ray diffraction (XRD) of the material. No significant evidence for degradation was observed although disproportionation had been seen previously when ZrNiHx was heated above 675 K. The resistance of the present samples to degradation is primarily attributed to the lower desorption temperature during cycling. (C) 2003 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Prina, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mauro.prina@jpl.nasa.gov NR 41 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 30 PY 2004 VL 373 IS 1-2 BP 104 EP 114 DI 10.1016/j.jallcom.2003.10.053 PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 826VR UT WOS:000221858100018 ER PT J AU Nakamura, Y Bowman, RC Akiba, E AF Nakamura, Y Bowman, RC Akiba, E TI Strain formation and lattice parameter change in LaN4.75Sn0.25-H system during the initial activation process SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE hydrogen storage; in situ XRD; Rietveld method; lattice strain; lattice parameter ID X-RAY-DIFFRACTION; HYDROGEN ABSORPTION; INTERMETALLIC COMPOUNDS; SORPTION CRYOCOOLERS; LANI5-BASED ALLOYS; SPACE APPLICATIONS; LANI5; DEGRADATION; DESORPTION; STABILITY AB Hydriding-dehydriding behavior of LaNi4.75Sn0.25 was investigated by means of in situ X-ray diffraction (XRD). Lattice strain formed only in the hydride phase during dehydriding in the two-phase region. Isotropic strain increased up to 1.7% with decreasing fraction of hydride phase accompanied with anisotropic strain of similar to0.7%. Significant lattice parameter change was observed in the hydride phase both in the single-phase and two-phase regions only in dehydriding but not in hydriding. Both lattice parameters a and c for the hydride phase decreased by about 0.005 nm over the two-phase region. The behavior of LaNi4.75Sn0.25 in lattice parameter change and lattice strain formation during hydriding-dehydriding are quite different from those observed in LaNi5 but are similar to those seen in LaNi4.75Al0.25. (C) 2003 Elsevier B.V. All rights reserved. C1 Natl Inst Adv Ind Sci & Technol, AIST, Hydrogen Energy Grp, Tsukuba, Ibaraki 3058565, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nakamura, Y (reprint author), Natl Inst Adv Ind Sci & Technol, AIST, Hydrogen Energy Grp, AIST Cent 5,1-1-1 Higashi, Tsukuba, Ibaraki 3058565, Japan. EM yumiko.nakamura@aist.gp.jp NR 28 TC 26 Z9 27 U1 0 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 30 PY 2004 VL 373 IS 1-2 BP 183 EP 193 DI 10.1016/j.jallcom.2003.10.049 PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 826VR UT WOS:000221858100031 ER PT J AU Manderson, JP Pessutti, J Hilbert, JG Juanes, F AF Manderson, JP Pessutti, J Hilbert, JG Juanes, F TI Shallow water predation risk for a juvenile flatfish (winter flounder; Pseudopleuronectes americanus, Walbaum) in a northwest Atlantic estuary SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE predation refuge; nursery habitat quality; tethering; juvenile fish mortality ID PLAICE PLEURONECTES-PLATESSA; SHRIMP CRANGON-SEPTEMSPINOSA; NEW-JERSEY ESTUARY; CORAL-REEF FISH; HABITAT USE; INTERTIDAL ZONE; CHESAPEAKE-BAY; BLUE CRABS; LABORATORY EXPERIMENTS; PARALICHTHYS-DENTATUS AB Many small fish, including several juvenile Atlantic flatfish, are most abundant in shallow areas presumable because these habitats enhance survivorship and/or growth. In this study, we investigated size-dependent depth distributions and the role of shallow habitats as predator refuges for age-0 winter flounder (Pseudopleuronectes americanus) in a northwest Atlantic estuarine nursery. Analysis of trawl surveys performed during the larval settlement period throughout the Navesink River and Sandy Hook Bay, New Jersey, showed that as fish increased in size, depth of occurrence gradually decreased, so that individuals >35 mm standard length (SL) were concentrated in habitats similar to 1 m deep. Tethering in structurally simple and adjacent shallow and deep habitats showed that predation risk for flounder (30-50 mm SL) was low in shallow water (< 1 m) and increased rapidly with depth. Summer flounder (Paralychthys dentatits), which were more abundant in trammel nets in deep habitats and included winter flounder in their diets, appeared to be important consumers of tethered fish. Our results indicate that following larval settlement, winter flounder emigrate from or suffer high mortality in deeper water to become concentrated in shallow habitats that can serve as predator refuges even when they lack complex physical structures. These results highlight the potential for functional habitat loss when natural and/or anthropogenic factors make shallow habitats unavailable to young fish. Published by Elsevier B.V. C1 NOAA, Natl Marine Fisheries Serv, Dept Commerce, Behav Ecol Branch,James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. Univ Massachusetts, Dept Nat Resources Conservat, Amherst, MA 01003 USA. RP Manderson, JP (reprint author), NOAA, Natl Marine Fisheries Serv, Dept Commerce, Behav Ecol Branch,James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. EM john.manderson@noaa.gov NR 82 TC 42 Z9 45 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD JUN 30 PY 2004 VL 304 IS 2 BP 137 EP 157 DI 10.1016/j.jembe.2003.12.004 PG 21 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 822WX UT WOS:000221572400001 ER PT J AU Mishra, AP Balasubramanian, TK Tipping, RH Ma, Q AF Mishra, AP Balasubramanian, TK Tipping, RH Ma, Q TI Absorption spectroscopy in solid hydrogen: challenges to experimentalists and theorists SO JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE solid hydrogen; zero-phonon transitions; single and double transitions; multipole-moment matrix elements; phonon renormalization ID ROVIBRATIONAL MATRIX-ELEMENTS; FOURIER-TRANSFORM SPECTROSCOPY; ZERO-PHONON TRANSITIONS; MULTIPOLE MOMENTS; INFRARED-SPECTRUM; OVERTONE REGION; RAMAN SPECTRA; DIATOMIC HYDROGEN; H-2 MOLECULE; PARAHYDROGEN AB Hydrogen is the most abundant molecule in the universe, and over the years has provided a fundamental testing ground for both theory and experiment. By symmetry, isolated H, molecules do not have allowed dipole rotational or vibration-rotational spectra. However, when they interact in the gas, liquid, or solid, there are induced dipoles that can interact with radiation. In the solid because of the large lattice constant, these dipoles arise primarily from the long-range induction by multipole moments of one molecule with the polarizability in its neighbors. By analyzing the intensities, one is able to obtain experimental values for not only the quadrupole moment, but also for higher-order moments as well. In the present paper, we review only a very limited part of the extensive research that has been carried out; namely, that of solid H,, although extensive experimental and theoretical results for other phases and for other isotopes exist. Solid H, is a quantum crystal, in which the individual molecules undergo almost free rotation and vibration in the hcp lattice. This simplifies the identification of the observed transitions based on their frequencies calculated from well-known gaseous spectroscopic constants. Although high-resolution studies have revealed subtle effects such as crystal-field splittings, interferences between the allowed and induced dipoles in HD, structure of the phonon density of states, triple transitions, etc. we limit ourselves to only the zero-phonon single and double transitions in para-hydrogen, or for an isolated ortho-hydrogen molecule in a para-hydrogen environment. We review the extensive literature over the last four decades, and present comparisons between theory and experiment. From this analysis, we can draw a number of conclusions about the accuracy and consistency of the experimental data and the need for improvements in theory. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Bhabha Atom Res Ctr, Div Spect, Modular Labs, Bombay 400085, Maharashtra, India. Columbia Univ, Dept Appl Phys, New York, NY 10025 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Tipping, RH (reprint author), Univ Alabama, Dept Phys & Astron, 206 Gallalee,Box 870324, Tuscaloosa, AL 35487 USA. EM rtipping@bama.ua.edu NR 64 TC 12 Z9 12 U1 2 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2860 J9 J MOL STRUCT JI J. Mol. Struct. PD JUN 30 PY 2004 VL 695 SI SI BP 103 EP 109 DI 10.1016/j.molstruc.2003.10.050 PG 7 WC Chemistry, Physical SC Chemistry GA 827SV UT WOS:000221922000010 ER PT J AU Brown, LR Nikitin, A Benner, DC Devi, VM Smith, MAH Fejard, L Champion, JP Tyuterev, VG Sams, RL AF Brown, LR Nikitin, A Benner, DC Devi, VM Smith, MAH Fejard, L Champion, JP Tyuterev, VG Sams, RL TI Line intensities of CH3D in the Triad region: 6-10 mu m SO JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE monodeuterated methane; CH3D Triad; fundamentals; hotbands; intensities ID PERTURBATION-ALLOWED TRANSITIONS; DIODE-LASER MEASUREMENTS; INFRARED-SPECTRUM; ABSORPTION INTENSITIES; POLYATOMIC-MOLECULES; ROTATIONAL ANALYSIS; GROUND-STATE; HALF-WIDTHS; (CH3D)-C-12; METHANE AB Line intensities of the three lowest fundamentals of the (CH3D)-C-12 Triad are modeled with an RMS of 3.2% using over 2 100 observed values retrieved by multispectrurn fitting of enriched sample spectra recorded with two Fourier transform spectrometers. The band strengths of the Triad in units of 10(-18) cm(-1)/(molecule cm(-2)) at 296 K are, respectively, 2.33 for v(6) (E) at 1161 cm(-1), 1.75 for v(3) (A(1)) at 1307 cm(-1) and 0.571 for v(5) (E) at 1472 cm(-1). The total calculated absorption arising from (CH3D)-C-12 Triad fundamentals is 4.65 x 10(-18) cm(-1)/(molecule cm-2) at 296 K. In addition. some 740 intensities of nine hotbands are fitted to 8.1%; most of the hotband measurements belong to 2v(6) - v(6) and v(3) + v(6) - v(3) near 1160 cm(-1) 2(v)3 - v(3) near 1290 cm(-1) and v(3) + v(6) - v(6) near 1304 cm(-1). The other observed hotbands are v(5) + v(6) - v(6), 2v(5) - v(5), v(5) + v(6) - v(5), v(3) + v(5) - v(3), and v(3) + v(5) - v(5). (C) 2004 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Russian Acad Sci, Inst Atmospher Opt, Lab Theoret Spect, Tomsk 634055, Russia. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Bourgogne, CNRS, Phys Lab, F-21078 Dijon, France. Fac Sci, UMR CNRS 6089, Grp Spectrometrie Mol & Atmospher, F-56187 Reims 2, France. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Brown, LR (reprint author), CALTECH, Jet Prop Lab, MS 183-601,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM linda.brown@jpl.nasa.gov RI Champion, Jean-Paul/C-3963-2009; Nikitin, Andrei/K-2624-2013 OI Nikitin, Andrei/0000-0002-4280-4096 NR 38 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2860 J9 J MOL STRUCT JI J. Mol. Struct. PD JUN 30 PY 2004 VL 695 SI SI BP 181 EP 188 DI 10.1016/j.molstruc.2003.12.041 PG 8 WC Chemistry, Physical SC Chemistry GA 827SV UT WOS:000221922000017 ER PT J AU Petkie, DT Butler, RAH Helminger, P De Lucia, FC AF Petkie, DT Butler, RAH Helminger, P De Lucia, FC TI Molecular structure, spectral constants, and fermi resonances in chlorine nitrate SO JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE chlorine nitrate; fermi resonances; anharmonic resonances; rotational constants; vibration-rotation constants ID MILLIMETER-WAVE SPECTRUM; EXPERIMENTAL ROTATIONAL-CONSTANTS; HARMONIC FORCE-FIELD; EQUILIBRIUM STRUCTURES; SPECTROSCOPY; CLONO2; HNO3; DYAD AB Chlorine nitrate has two low-lying vibrational modes that lead to a series of Fermi resonances in the 9(v9)7(v7) family of levels that include the 9(2) double left right arrow 7(1) and 9(3) double left right arrow 7(1)9(1) dyads and the 9(4) double left right arrow 9(2)7(1) double left right arrow 7(2) and 9(5) double left right arrow 9(3)7(1) double left right arrow 9(1)7(2) triads. These states, along with the ground and 9(1) vibrational states, have been previously analyzed with millimeter and submillimeter wave spectroscopy and provide a substantial body of data for the investigation of these resonances and their impact on calculated spectroscopic constants and structural parameters. Due to fitting indeterminacies, these previous analyses did not include the main Fermi resonance interaction term. Consequently, the fitted rotational constants are linear combinations of the unmixed rotational constants of the basis vibrational states. In this paper, we have calculated the contributions of the Fermi resonances to the observed rotational constants in a model that determines the vibrational-rotational constants, the Fermi term and the mixing between interacting vibrational states, the cubic potential constant (phi(997)) that connects interacting levels through a Fermi resonance, and the inertial defects. These results agree with predictions from ab initio and harmonic force field calculations and provide further experimental information for the determination of the fundamental molecular properties of chlorine nitrate. (C) 2003 Elsevier B.V. All rights reserved. C1 Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ S Alabama, Dept Phys, Mobile, AL 36688 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Wright State Univ, Dept Phys, Dayton, OH 45435 USA. RP De Lucia, FC (reprint author), Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA. EM fcd@mps.ohio-state.edu NR 26 TC 3 Z9 4 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2860 J9 J MOL STRUCT JI J. Mol. Struct. PD JUN 30 PY 2004 VL 695 SI SI BP 287 EP 293 DI 10.1016/j.molstruc.2003.12.007 PG 7 WC Chemistry, Physical SC Chemistry GA 827SV UT WOS:000221922000028 ER PT J AU Li, C Fan, W Straus, DA Lei, B Asano, S Zhang, DH Han, J Meyyappan, M Zhou, CW AF Li, C Fan, W Straus, DA Lei, B Asano, S Zhang, DH Han, J Meyyappan, M Zhou, CW TI Charge storage behavior of nanowire transistors functionalized with bis(terpyridine)-Fe(II) molecules: Dependence on molecular structure SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; CRYSTALLINE IN2O3 NANOWIRES; COMPLEXES; MEMORY; RUTHENIUM(II); OPERATION; ARRAYS C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. Univ So Calif, Dept Elect Engn Electrophys, Los Angeles, CA 90089 USA. San Jose State Univ, Dept Chem, San Jose, CA 95192 USA. RP Zhou, CW (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM wfan@mail.arc.nasa.gov; chongwuz@usc.edu RI Zhou, Chongwu/F-7483-2010 NR 21 TC 41 Z9 42 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUN 30 PY 2004 VL 126 IS 25 BP 7750 EP 7751 DI 10.1021/ja049368c PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 831SY UT WOS:000222217600010 PM 15212502 ER PT J AU Wu, DL AF Wu, DL TI Mesoscale gravity wave variances from AMSU-A radiances SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MIDDLE ATMOSPHERE; SATELLITE-OBSERVATIONS; MOUNTAIN WAVES; STRATOSPHERE; VARIABILITY; CLIMATOLOGY AB A variance analysis technique is developed here to extract gravity wave (GW) induced temperature fluctuations from NOAA AMSU-A (Advanced Microwave Sounding Unit-A) radiance measurements. By carefully removing the instrument/measurement noise, the algorithm can produce reliable GW variances with the minimum detectable value as small as 0.1 K-2. Preliminary analyses with AMSU-A data show GW variance maps in the stratosphere have very similar distributions to those found with the UARS MLS (Upper Atmosphere Research Satellite Microwave Limb Sounder). However, the AMSU-A offers better horizontal and temporal resolution for observing regional GW variability, such as activity over sub-Antarctic islands. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wu, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM dwu@mls.jpl.nasa.gov RI Wu, Dong/D-5375-2012 NR 18 TC 46 Z9 46 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 29 PY 2004 VL 31 IS 12 AR L12114 DI 10.1029/2004GL019562 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 839JF UT WOS:000222779400002 ER PT J AU Hospodarsky, GB Kurth, WS Cecconi, B Gurnett, DA Kaiser, ML Desch, MD Zarka, P AF Hospodarsky, GB Kurth, WS Cecconi, B Gurnett, DA Kaiser, ML Desch, MD Zarka, P TI Simultaneous observations of Jovian quasi-periodic radio emissions by the Galileo and Cassini spacecraft SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE Jovian low-frequency radio bursts; quasi-periodic radio bursts; Jupiter radio emissions ID JUPITERS MAGNETOSPHERE; ESCAPE PATHS; BURSTS; RAY AB [1] The gravity-assist flyby by Cassini of Jupiter on 30 December 2000 and the extended Galileo orbital mission provided a unique opportunity to obtain simultaneous measurements with two spacecraft of many Jovian plasma wave and radio emissions. One of these emissions is Jovian type III radio emissions, also known as Jovian quasi- periodic (QP) emissions. The simultaneous observations of the QP emissions show very similar characteristics, even when the two spacecraft are separated by large distances and located at very different local times (LT). These similarities suggest that this emission is beamed in a strobe light like manner (over a large angular range) and not like a search light rotating with Jupiter's magnetic field, as many other Jovian radio emissions are. The initial source of the QP bursts is likely located near Jupiter. As the emissions propagate through the magnetosphere, the QP bursts appear as enhancements of the trapped continuum. At the magnetosheath the higher density plasma disperses the lower frequency component of the bursts, producing the characteristic "type III like'' spectral shape. C1 Univ Iowa, Dept Phys & Astron, Iowa City, IA 52232 USA. Observ Paris, Lab Etud Spatiales & Instrumentat Astrophys, F-92190 Meudon, France. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Hospodarsky, GB (reprint author), Univ Iowa, Dept Phys & Astron, Iowa City, IA 52232 USA. EM george-hospodarsky@uiowa.edu; william-kurth@uiowa.edu; baptiste.cecconi@obspm.fr; donald-gurnett@uiowa.edu; michael.kaiser@nasa.gov; michael.desch@nasa.gov; phillipe.zarka@obspm.fr OI Hospodarsky, George/0000-0001-9200-9878; Kurth, William/0000-0002-5471-6202 NR 28 TC 12 Z9 12 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 29 PY 2004 VL 109 IS A9 AR A09S07 DI 10.1029/2003JA010263 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 839NZ UT WOS:000222793100006 ER PT J AU Kaiser, ML Farrell, WM Kurth, WS Hospodarsky, GB Gurnett, DA AF Kaiser, ML Farrell, WM Kurth, WS Hospodarsky, GB Gurnett, DA TI New observations from Cassini and Ulysses of Jovian VLF radio emissions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE Jupiter; radio; VLF ID ESCAPE PATHS; JUPITER; BURSTS; CONTINUUM; BEHAVIOR AB [ 1] Simultaneous observations of Jupiter's so-called reradiated VLF radio emission by the Cassini and Ulysses spacecraft confirm that the emission is radiated into all directions in a pulse or strobe light-like fashion. These observations rule out a source that corotates with the planet. Observations of the same VLF emission component during the Cassini distant flyby of Jupiter in early 2001 strongly suggest that the emission, which originates fairly close to the planet, is modified by the magnetosheath so that the magnetosheath acts as a leaky wave guide of VLF radiation. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Kaiser, ML (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM michael.kaiser@nasa.gov; farrell@faltraz.gsfc.nasa.gov; william-kurth@uiowa.edu; gbh@space.physics.uiowa.edu; donald-gurnett@uiowa.edu RI Farrell, William/I-4865-2013; OI Hospodarsky, George/0000-0001-9200-9878; Kurth, William/0000-0002-5471-6202 NR 15 TC 6 Z9 6 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 29 PY 2004 VL 109 IS A9 AR A09S08 DI 10.1029/2003JA010233 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 839NZ UT WOS:000222793100003 ER PT J AU Zhou, LM Dickinson, RE Tian, YH Fang, JY Li, QX Kaufmann, RK Tucker, CJ Myneni, RB AF Zhou, LM Dickinson, RE Tian, YH Fang, JY Li, QX Kaufmann, RK Tucker, CJ Myneni, RB TI Evidence for a significant urbanization effect on climate in China SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID LAND-USE CHANGE; URBAN HEAT-ISLAND; MINIMUM TEMPERATURE; UNITED-STATES; TRENDS; REANALYSIS; MAXIMUM; IMPACT AB China has experienced rapid urbanization and dramatic economic growth since its reform process started in late 1978. In this article, we present evidence for a significant urbanization effect on climate based on analysis of impacts of land-use changes on surface temperature in southeast China, where rapid urbanization has occurred. Our estimated warming of mean surface temperature of 0.05degreesC per decade attributable to urbanization is much larger than previous estimates for other periods and locations. The spatial pattern and magnitude of our estimate are consistent with those of urbanization characterized by changes in the percentage of urban population and in satellite-measured greenness. C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Boston Univ, Dept Geog, Boston, MA 02215 USA. China Meteorol Adm, Natl Meteorol Ctr, Beijing 100081, Peoples R China. Peking Univ, Minist Educ, Key Lab Earth Surface Proc, Beijing 100871, Peoples R China. Peking Univ, Dept Urban & Environm Sci, Beijing 100871, Peoples R China. RP Zhou, LM (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, 311 Ferst Dr, Atlanta, GA 30332 USA. EM lmzhou@eas.gatech.edu RI Fang, Jingyun/A-4282-2009; Zhou, Liming/A-2688-2012; Myneni, Ranga/F-5129-2012 NR 31 TC 294 Z9 376 U1 26 U2 204 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUN 29 PY 2004 VL 101 IS 26 BP 9540 EP 9544 DI 10.1073/pnas.0400357101 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 834IU UT WOS:000222405600006 PM 15205480 ER PT J AU Stewart, RW AF Stewart, RW TI The annual cycle of hydrogen peroxide: an indicator of chemical instability? SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID ATMOSPHERIC CHEMISTRY; TROPOSPHERIC PHOTOCHEMISTRY; DYNAMIC INSTABILITY; LOS-ANGELES; OZONE; MODEL; NOX; TRANSITION; STATES; SYSTEM AB A box model has been used to study the annual cycle in hydrogen peroxide concentrations with the objective of determining whether the observed difference in summer and winter values reflects instability in the underlying photochemistry. The model is run in both steady-state and time-dependent modes. The steady-state calculations show that, for some range of NOx background levels, two stable solutions to the continuity equations exist for a period of days in spring and fall. The corresponding time-dependent model indicates that, for sufficiently high background NOx concentrations, the spring and fall changes in H2O2 concentration may be interpreted as a forced transition between the two underlying stable regimes. The spring transition is more rapid than that in fall, an asymmetry that becomes more marked as background NOx increases. This asymmetry is related to the different time scales involved in chemical production and loss of H2O2. Observations of the spring increase in H2O2 concentration may therefore provide a better measure of the change in the underlying chemical regime than does the fall decrease. The model results developed in this paper will be compared with two sets of observations that cover annual variations of peroxide concentrations under different background pollution conditions. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Stewart, RW (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Richard.W.Stewart@nasa.gov NR 46 TC 2 Z9 2 U1 0 U2 5 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JUN 25 PY 2004 VL 4 BP 933 EP 946 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 832KX UT WOS:000222267500001 ER PT J AU Bamber, J Krabill, W Raper, V Dowdeswell, J AF Bamber, J Krabill, W Raper, V Dowdeswell, J TI Anomalous recent growth of part of a large Arctic ice cap: Austfonna, Svalbard SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MASS-BALANCE; GLACIERS; SHEET; NORDAUSTLANDET; ACCUMULATION; EXTENT; LAYERS; COVER AB Observations from repeat-pass airborne laser altimetry, acquired in 1996 and 2002, indicate an anomalous positive ice-surface elevation change for the central accumulation area of the largest ice cap in the Eurasian Arctic; Austfonna, eastern Svalbard. The increase is equivalent to 35% of the long-term annual accumulation rate and coincides with the loss of perennial sea ice in the adjacent Barents Sea, which we conclude is the most likely explanation for the increase. Extrapolation of the observed trends in sea ice decline, over the next 50 years, suggests large perturbations in the mass-balance of other Arctic ice masses may be expected. C1 Univ Bristol, Sch Geog Sci, Bristol Glaciol Ctr, Bristol BS8 1SS, Avon, England. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. Univ Cambridge, Scott Polar Res Inst, Cambridge CB2 1ET, England. RP Bamber, J (reprint author), Univ Bristol, Sch Geog Sci, Bristol Glaciol Ctr, Univ Rd, Bristol BS8 1SS, Avon, England. EM j.bamber@bris.ac.uk; krabill@osb1.wff.nasa.gov; jd16@cam.ac.uk RI Bamber, Jonathan/C-7608-2011 OI Bamber, Jonathan/0000-0002-2280-2819 NR 20 TC 41 Z9 42 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 25 PY 2004 VL 31 IS 12 AR L12402 DI 10.1029/2004GL019667 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 839HN UT WOS:000222774700003 ER PT J AU Kittaka, C Pierce, RB Crawford, JH Hitchman, MH Johnson, DR Tripoli, GJ Chin, M Bandy, AR Weber, RJ Talbot, RW Anderson, BE AF Kittaka, C Pierce, RB Crawford, JH Hitchman, MH Johnson, DR Tripoli, GJ Chin, M Bandy, AR Weber, RJ Talbot, RW Anderson, BE TI A three-dimensional regional modeling study of the impact of clouds on sulfate distributions during TRACE-P SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE TRACE-P; in-cloud processing ID CHEMICAL-TRANSPORT MODELS; AEROSOL; ASIA; PACIFIC; CONVECTION; GOCART; OZONE; CYCLE; CO; TROPOSPHERE AB The University of Wisconsin Nonhydrostatic Modeling System (UWNMS) is combined with an aqueous sulfur chemistry module to simulate the sulfate transport in east Asia during the Transport and Chemical Evolution Over the Pacific (TRACE-P) period. The simulated results are compared with in situ and satellite measurements collected during the TRACE-P period. The comparisons showed overestimates of sulfate mixing ratios by 20% between 1 and 6 km and underestimates by 30% near the surface and by 50% above 6 km. The comparisons of the sulfate mixing ratios between the simulation and the measurements for a case study of a convective system showed an excellent agreement in the background sulfate mixing ratios. The simulated sulfate mixing ratios in cloudy regions, however, were underestimated by a factor of 2. Volume-integrated sulfate mass in the model domain is calculated. Significant amounts of sulfate (volume-integrated mass 1.5 x 10(6) to 7.5 x 10(6) kg) are released into air after being produced in clouds through the oxidation of sulfur dioxide by hydrogen peroxide. Instantaneous sulfate mass within clouds varies from 0.2 x 10(6) to 3.5 x 10(6) kg. Sulfate mass removed through precipitation is in the ranges between 0.01 x 10(6) and 1.8 x 10(6) kg. Sulfate mass in ice clouds was 2 orders of magnitude smaller than that in liquid clouds. This study shows that the sulfate input to the atmosphere exceeds the sulfate removed from the atmosphere through precipitation in the east Asian region during the TRACE-P. Consequently, east Asia in spring can be an important source region of sulfate and thus can offset the sulfate loss through precipitation scavenging in other regions of the globe. C1 NASA, Sci Applicat Int Corp, Langley Res Ctr, Hampton, VA 23681 USA. Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI 53706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, EOS, Durham, NH 03824 USA. RP NASA, Sci Applicat Int Corp, Langley Res Ctr, Mail Stop 401B, Hampton, VA 23681 USA. EM fn.c.kittaka@larc.nasa.gov; robert.b.pierce@nasa.gov; james.h.crawford@nasa.gov; matt@aos.wisc.edu; donj@ssec.wisc.edu; tripoli@aos.wisc.edu; mian.chin@nasa.gov; bandyar@drexel.edu; rweber@eas.gatech.edu; robert.talbot@unh.edu; bruce.e.anderson@nasa.gov RI Pierce, Robert Bradley/F-5609-2010; Chin, Mian/J-8354-2012; Crawford, James/L-6632-2013 OI Pierce, Robert Bradley/0000-0002-2767-1643; Crawford, James/0000-0002-6982-0934 NR 42 TC 5 Z9 6 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 25 PY 2004 VL 109 IS D15 AR D15S11 DI 10.1029/2003JD004353 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 839ID UT WOS:000222776400001 ER PT J AU Kojima, T Buseck, PR Wilson, JC Reeves, JM Mahoney, MJ AF Kojima, T Buseck, PR Wilson, JC Reeves, JM Mahoney, MJ TI Aerosol particles from tropical convective systems: Cloud tops and cirrus anvils SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE transmission electron microscopy; cirrus clouds; ice nucleation; lower stratosphere; upper troposphere; sulfuric acid ID HOMOGENEOUS ICE NUCLEATION; LOWER STRATOSPHERE; UPPER TROPOSPHERE; SNOW CRYSTALS; CARBONACEOUS PARTICLES; SULFATE PARTICLES; SOUTHERN AFRICA; SULFURIC-ACID; UNITED-STATES; AIRCRAFT AB Aerosol particles from the upper troposphere (UT) and lower stratosphere (LS) were collected during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) and studied by transmission electron microscopy (TEM). Samples were classified into three categories: (1) UT in-cloud, (2) UT out-of-cloud, and (3) LS. Sulfate particles, including former H2SO4 droplets, are dominant in samples from all categories. The morphology of H2SO4 droplets indicates that they had been ammoniated to some extent at the time of collection. They are internally mixed with organic materials, metal sulfates, and solid particles of various compositions. K- and S-bearing organic particles and Si-Al-rich particles are common to the three kinds of samples. In-cloud samples contain abundant Zn-rich particles. Their origin is unclear, but it seems likely that they are contaminants that originated through impact by ice cloud particles on the aircraft or sampling system. Ammoniation and internal mixing of H2SO4 in the UT aerosols may result in freezing at higher temperature than in pure H2SO4 aerosols. The relatively high extent of ammoniation in the UT in-cloud samples may have resulted from vertical transport of ammonia by strong convection. Abundances of nonsulfate particles decrease with increasing altitudes. The nonsulfate particles originated from the lower troposphere and were transported to the UT and LS. C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Denver, Dept Engn, Denver, CO 80208 USA. RP Kojima, T (reprint author), Kumamoto Univ, Fac Sci, Kumamoto 8608555, Japan. EM tkojima@sci.kumamoto-u.ac.jp; pbuseck@asu.edu; jwilson@du.edu; jreeves@du.edu; michael.j.mahoney@jpl.nasa.gov NR 45 TC 26 Z9 27 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 25 PY 2004 VL 109 IS D12 AR D12201 DI 10.1029/2003JD004504 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 839HY UT WOS:000222775900002 ER PT J AU Ohno, M Fukazawa, Y Iyomoto, N AF Ohno, M Fukazawa, Y Iyomoto, N TI Reflection component in the hard X-ray emission from the Seyfert 2 Galaxy Mrk 1210 SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE galaxies : active; galaxies : nuclei; galaxies : Seyfert; X-rays : galaxies ID ENERGY CONCENTRATOR SPECTROMETER; ASTRONOMY SATELLITE; ON-BOARD; VARIABILITY; NUCLEUS; AGN AB The Seyfert 2 galaxy Mrk 1210 was found to exhibit a flat hard X-ray component by ASCA, although ASCA could not distinguish whether it is an absorbed direct component or a reflected one. We then observed Mrk 1210 with BeppoSAX, and found that the X-ray spectral properties are quite different from those of ASCA, as have been confirmed with XMM-Newton; the flux is significantly higher than that in the ASCA observation, and a clear absorption cut-off appears below 5 keV. A bright hard X-ray emission is detected up to 100 keV. The reflection component is necessary to describe the BeppoSAX PDS spectrum, and represents the ASCA hard component very well. Therefore, the hard component in the ASCA spectrum is a reflected one, whose intensity is almost constant over 6 yr. This indicates that a dramatic spectral variability is attributed to a large change of the absorption column density by a factor of > 5, rather than the variability of the nuclear emission. The change in the absorption column density means that the torus is not homogeneous, but has a blobby structure with a typical blob size of < 0.001 pc. C1 Hiroshima Univ, Sch Sci, Dept Phys Sci, Higashihiroshima, Hiroshima 7398526, Japan. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Hiroshima Univ, Sch Sci, Dept Phys Sci, 1-3-1 Kagamiyama, Higashihiroshima, Hiroshima 7398526, Japan. EM ohno@hirax7.hepl.hiroshima-u.ac.jp NR 18 TC 11 Z9 11 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 2004 VL 56 IS 3 BP 425 EP 429 DI 10.1093/pasj/56.3.425 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 834IL UT WOS:000222404700004 ER PT J AU Nesterov, VV Antipin, MY Nesterov, VN Moore, CE Cardelino, BH Timofeeva, TV AF Nesterov, VV Antipin, MY Nesterov, VN Moore, CE Cardelino, BH Timofeeva, TV TI Thermally stable heterocyclic imines as new potential nonlinear optical materials SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MOLECULAR HYPERPOLARIZABILITIES; HYDRAZONE DERIVATIVES; CRYSTAL-STRUCTURES; ORGANIC-MOLECULES; X-RAY; POLARIZABILITIES; DESIGN; DICYANOVINYLBENZENE; STILBENES AB In the course of a search for new thermostable acentric nonlinear optical crystalline materials, several heterocyclic imine derivatives were designed, with the general structure D-pi-A(D'). Introduction of a donor amino group (U) into the acceptor moiety was expected to bring H-bonds into their crystal structures, and so to elevate their melting points and assist in an acentric molecular packing. Six heterocycle-containing compounds of this type were prepared, single crystals were grown for five of them, and these crystals were characterized by X-ray analysis. A significant melting temperature elevation was found for all of the synthesized compounds. Three of the compounds were also found to crystallize in acentric space groups. One of the acentric compounds is built as a three-dimensional H-bonded molecular network. In the other two compounds, with very similar molecular structure, the molecules form one-dimensional H-bonded head-to-head associates (chains). These chains are parallel in two different crystallographic directions and form very unusual interpenetrating chain patterns in an acentric crystal. Two of the compounds crystallized with centrosymmetric molecular packing. C1 New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA. Russian Acad Sci, Inst Organoelement Cpds, Moscow, Russia. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. Spelman Coll, Dept Chem, Atlanta, GA 30314 USA. RP Timofeeva, TV (reprint author), New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA. EM tvtiniofeeva@nmhu.edu NR 29 TC 12 Z9 12 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 24 PY 2004 VL 108 IS 25 BP 8531 EP 8539 DI 10.1021/jp0367528 PG 9 WC Chemistry, Physical SC Chemistry GA 830MI UT WOS:000222125900005 ER PT J AU Hu, ZY Fort, A Barzoukas, M Jen, AKY Barlow, S Marder, SR AF Hu, ZY Fort, A Barzoukas, M Jen, AKY Barlow, S Marder, SR TI Trends in optical nonlinearity and thermal stability in electrooptic chromophores based upon the 3-(dicyanomethylene)-2,3-dihydrobenzothiopene-1, 1-dioxide acceptor SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID BOND-LENGTH ALTERNATION; PUSH-PULL POLYENES; BETA-KETO SULFONES; PHOTOREFRACTIVE POLYMERS; HETEROCYCLIC ACCEPTORS; HIGHLY EFFICIENT; DIPOLE-MOMENT; DYES; HYPERPOLARIZABILITIES; MOLECULES AB A series of new thiophene-bridged chromophores based on the powerful heterocyclic acceptor 3-(dicyanomethylene)-2,3-dihydrobenzothiophene-1,1-dioxide has been synthesized; the dependence of the linear and second-order nonlinear optical properties and thermal stability of these species upon the donor group and the bridging group have been studied. In addition, the synthesis of a related new acceptor, not containing the fused benzene ring, is described and a chromophore based upon this acceptor is studied. C1 CALTECH, Beckman Inst, Pasadena, CA 91125 USA. CNRS, UM 046, Inst Phys & Chem Mat Strasbourg, F-67037 Strasbourg, France. ROI Technol, Opt Mat Div, Monmouth Jct, NJ 08852 USA. Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. Univ Washington, Dept Mat Sci & Engn, Seattle, WA 98195 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Beckman Inst, Pasadena, CA 91125 USA. EM seth.marder@chemistry.gatech.edu RI Jen, Alex/E-5957-2012; Barlow, Stephen/E-9754-2010 NR 70 TC 42 Z9 43 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 24 PY 2004 VL 108 IS 25 BP 8626 EP 8630 DI 10.1021/jp036728u PG 5 WC Chemistry, Physical SC Chemistry GA 830MI UT WOS:000222125900019 ER PT J AU Imhoff, ML Bounoua, L Ricketts, T Loucks, C Harriss, R Lawrence, WT AF Imhoff, ML Bounoua, L Ricketts, T Loucks, C Harriss, R Lawrence, WT TI Global patterns in human consumption of net primary production SO NATURE LA English DT Article ID HUMAN APPROPRIATION; ECOLOGICAL FOOTPRINT; PHOTOSYNTHESIS; ECOSYSTEMS; MODEL AB The human population and its consumption profoundly affect the Earth's ecosystems(1,2). A particularly compelling measure of humanity's cumulative impact is the fraction of the planet's net primary production that we appropriate for our own use(3,4). Net primary production-the net amount of solar energy converted to plant organic matter through photosynthesis-can be measured in units of elemental carbon and represents the primary food energy source for the world's ecosystems. Human appropriation of net primary production, apart from leaving less for other species to use, alters the composition of the atmosphere(5), levels of biodiversity(6), energy flows within food webs(7) and the provision of important ecosystem services(8). Here we present a global map showing the amount of net primary production required by humans and compare it to the total amount generated on the landscape. We then derive a spatial balance sheet of net primary production 'supply' and 'demand' for the world. We show that human appropriation of net primary production varies spatially from almost zero to many times the local primary production. These analyses reveal the uneven footprint of human consumption and related environmental impacts, indicate the degree to which human populations depend on net primary production 'imports' and suggest policy options for slowing future growth of human appropriation of net primary production. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. World Wildlife Fund, Washington, DC 20037 USA. Stanford Univ, Dept Biol Sci, Stanford, CA 94305 USA. Natl Ctr Atmospher Res, Foothills Lab, Environm & Societal Impacts Grp, Boulder, CO 80307 USA. Bowie State Univ, Dept Nat Sci, Bowie, MD 20715 USA. RP Imhoff, ML (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. EM Marc.L.Imhoff@nasa.gov NR 29 TC 271 Z9 283 U1 19 U2 173 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 24 PY 2004 VL 429 IS 6994 BP 870 EP 873 DI 10.1038/nature02619 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 831RE UT WOS:000222213000041 PM 15215863 ER PT J AU Pan, FF Peters-Lidard, CD Sale, MJ King, AW AF Pan, FF Peters-Lidard, CD Sale, MJ King, AW TI A comparison of geographical information systems-based algorithms for computing the TOPMODEL topographic index SO WATER RESOURCES RESEARCH LA English DT Article DE GIS; TOPMODEL; topographic index; single flow direction algorithm; biflow direction algorithm; multiple flow direction algorithm ID DIGITAL ELEVATION DATA; SPATIALLY-VARIABLE WATER; ENERGY-BALANCE PROCESSES; MODELS; EXTRACTION; NETWORKS; SLOPE; AREAS; DEMS AB [1] The performance of six geographical information systems (GIS)-based topographic index algorithms is evaluated by computing root-mean-square errors of the computed and the theoretical topographic indices of three idealized hillslopes: planar, convergent, and divergent. In addition to these three idealized cases, two divergent hillslopes with varying slopes, i.e., concave ( slopes decrease from top to bottom) and convex ( slopes increase from top to bottom) are also tested. The six GIS-based topographic index algorithms are combinations of flow direction and slope algorithms: i.e., single flow direction (SFD), biflow direction (BFD), and multiple flow direction (MFD) plus methods that determine slope values in flat areas, e. g., W-M method [Wolock and McCabe, 1995] and tracking flow direction (TFD) method. Two combinations of horizontal resolution and vertical resolution of the idealized terrain data are used to evaluate those methods. Among those algorithms the MFD algorithm is the most accurate followed by the BFD algorithm and the SFD algorithm. As the vertical resolution increases, the errors in the computed topographic index for all algorithms decrease. We found that the orientation of the contour lines of planar hillslopes significantly influences the SFD's computed topographic index. If the contour lines are not parallel to one of eight possible flow directions, the errors in the SFD's computed topographic index are significant. If mean slope is small, TFD becomes more accurate because slope values in flat areas are better estimated. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20071 USA. RP Pan, FF (reprint author), Oak Ridge Natl Lab, Div Environm Sci, MS 6335, Oak Ridge, TN 37831 USA. EM panf@ornl.gov RI Pan, Feifei/D-3370-2015; Peters-Lidard, Christa/E-1429-2012 OI Pan, Feifei/0000-0003-4373-7566; Peters-Lidard, Christa/0000-0003-1255-2876 NR 23 TC 24 Z9 24 U1 3 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUN 24 PY 2004 VL 40 IS 6 AR W06303 DI 10.1029/2004WR003069 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 839JA UT WOS:000222778700005 ER PT J AU Anderson, CM Chanover, NJ McKay, CP Rannou, P Glenar, DA Hillman, JJ AF Anderson, CM Chanover, NJ McKay, CP Rannou, P Glenar, DA Hillman, JJ TI Titan's haze structure in 1999 from spatially-resolved narrowband imaging surrounding the 0.94 mu m methane window SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERE; AEROSOLS; HST AB We use narrowband images of Titan obtained in November 1999 to explore the haze vertical structure in Titan's lower atmosphere. The images were taken with the Mount Wilson 2.54 m telescope using the NASA/GSFC-built Acousto-Optic Imaging Spectrometer. These images were recorded at five wavelengths surrounding the 0.94 mum methane window and are sensitive to a range of altitudes in Titan's lower atmosphere. We characterize Titan's limb darkening by fitting the Minnaert function limb darkening coefficient k to our data at 0degrees latitude and compare our observed limb darkening to that predicted from three radiative transfer models. The vertical haze profiles suggest a gap in haze below 75 km, with an increase in haze abundance near the surface. C1 New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. NASA, Div Space Sci, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ St Quentin, IPSL, Serv Aeron, F-91370 Verrieres Le Buisson, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Anderson, CM (reprint author), New Mexico State Univ, Dept Astron, Box 30001,Dept 4500, Las Cruces, NM 88003 USA. EM carrande@nmsu.edu RI Anderson, Carrie/C-8097-2012; RANNOU, Pascal/I-9059-2012 NR 15 TC 3 Z9 3 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 23 PY 2004 VL 31 IS 17 AR L17S06 DI 10.1029/2004GL019857 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 839HR UT WOS:000222775100001 ER PT J AU Olson, JR Crawford, JH Chen, G Fried, A Evans, MJ Jordan, CE Sandholm, ST Davis, DD Anderson, BE Avery, MA Barrick, JD Blake, DR Brune, WH Eisele, FL Flocke, F Harder, H Jacob, DJ Kondo, Y Lefer, BL Martinez, M Mauldin, RL Sachse, GW Shetter, RE Singh, HB Talbot, RW Tan, D AF Olson, JR Crawford, JH Chen, G Fried, A Evans, MJ Jordan, CE Sandholm, ST Davis, DD Anderson, BE Avery, MA Barrick, JD Blake, DR Brune, WH Eisele, FL Flocke, F Harder, H Jacob, DJ Kondo, Y Lefer, BL Martinez, M Mauldin, RL Sachse, GW Shetter, RE Singh, HB Talbot, RW Tan, D TI Testing fast photochemical theory during TRACE-P based on measurements of OH, HO2, and CH2O SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE TRACE-P; photochemistry; tropospheric chemistry ID DIODE-LASER MEASUREMENTS; MARINE BOUNDARY-LAYER; PEM-TROPICS-B; UPPER TROPOSPHERE; MODEL COMPARISONS; NORTH-ATLANTIC; CHEMICAL EVOLUTION; HYDROGEN RADICALS; IR PHOTOLYSIS; ODD-HYDROGEN AB Measurements of several short-lived photochemical species (e.g., OH, HO2, and CH2O) were obtained from the DC-8 and P3-B aircraft during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) campaign. To assess fast photochemical theory over the east Asian coast and western Pacific, these measurements are compared to predictions using a photochemical time-dependent box model constrained by coincident measurements of long-lived tracers and physical parameters. Both OH and HO2 are generally overpredicted by the model throughout the troposphere, which is a different result from previous field campaigns. The calculated-to-observed ratio of OH shows an altitude trend, with OH overpredicted by 80% in the upper troposphere and by 40-60% in the middle troposphere. Boundary layer and lower tropospheric OH ratios decrease from middle tropospheric values to 1.07 for the DC-8 and to 0.70 for the P3-B. HO2 measured on the DC-8 is overpredicted by a median of 23% and shows no trend in the agreement with altitude. Three subsets of data which compose 12% of the HO2 measurements represent outliers with respect to calculated-to-observed ratios: stratospherically influenced air, upper tropospheric data with NO > 135 pptv, and data from within clouds. Pronounced underpredictions of both HO2 and OH were found for stratospherically influenced air, which is in contrast to previous studies showing good agreement of predicted and observed HOx in the stratosphere. Observational evidence of heterogeneous uptake of HO2 within low and middle tropospheric clouds is presented, though there is no indication of significant HO2 uptake within higher-altitude clouds. Model predictions of CH2O are in good agreement with observations in the median for background concentrations, but a large scatter exists. Factors contributing to this scatter are examined, including the limited availability of some important constraining measurements, particularly CH3OOH. Some high concentrations of CH2O near the coast are underpredicted by the box model as a result of the inherent neglect of transport effects of CH2O and its precursors via the steady state assumption; however, these occurrences are limited to similar to1% of the data. For the vast majority of the atmosphere, transport is unimportant in the budget of CH2O, which may be considered to be in steady state. C1 NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Nagoya Univ, Solar Terr Environm Lab, Aichi 4228507, Japan. NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. Univ New Hampshire, Climate Change Res Ctr, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. RP Olson, JR (reprint author), NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. EM j.r.olson@larc.nasa.gov; james.h.crawford@nasa.gov; g.chen@larc.nasa.gov; fried@acd.ucar.edu; mje@io.harvard.edu; c.e.jordan@larc.nasa.gov; scott.sandholm@eas.gatech.edu; douglas.davis@eas.gatech.edu; b.e.anderson@larc.nasa.gov; m.a.avery@larc.nasa.gov; j.d.barrick@larc.nasa.gov; drblake@uci.edu; brune@essc.psu.edu; eisele@ncar.ucar.edu; ffl@acd.ucar.edu; harder@mpch-mainz.mpg.de; djj@io.harvard.edu; kondo@stelab.nagoya-u.ac.jp; lefer@ucar.edu; martinez@mpch-mainz.mpg.de; mauldin@ucar.edu; g.w.sachse@larc.nasa.gov; shetter@ucar.edu; hanwant.b.singh@nasa.gov; robert.talbot@unh.edu; dtan@eas.gatech.edu RI Kondo, Yutaka/D-1459-2012; Evans, Mathew/A-3886-2012; Crawford, James/L-6632-2013; Harder, Hartwig/L-2511-2014; Lefer, Barry/B-5417-2012 OI Evans, Mathew/0000-0003-4775-032X; Crawford, James/0000-0002-6982-0934; Harder, Hartwig/0000-0002-6868-714X; Lefer, Barry/0000-0001-9520-5495 NR 49 TC 36 Z9 36 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 22 PY 2004 VL 109 IS D15 AR D15S10 DI 10.1029/2003JD004278 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 839IC UT WOS:000222776300001 ER PT J AU Liou, K Newell, PT Meng, CI Wu, CC Lepping, RP AF Liou, K Newell, PT Meng, CI Wu, CC Lepping, RP TI On the relationship between shock-induced polar magnetic bays and solar wind parameters SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetic bays; substorms; storm sudden commencements; compression bays ID CAP INDEX; SUBSTORMS; AURORA AB There has been an impression for more than half a century that reductions in the north-south component of the Earth's magnetic field in the polar region (often called "negative magnetic bays'' or "polar magnetic bays'') may occur immediately after compression of the magnetosphere by interplanetary (IP) shock impacts, in particular when the magnetosphere is "preconditioned'' by southward interplanetary magnetic field ( IMF). A literature search suggests that this view has not been rigorously verified nor disproved. This paper reports a study of 43 IP shock events to illustrate the effect of IP shock-magnetosphere coupling on the high-latitude auroral electrojets. Specifically, we correlate the strength of magnetic bays ( inferred from minimum values of the AL index within a 30-min window after shock impact) with solar wind parameters and their combinations within the same time window. It is surprisingly found that the strength of magnetic bays correlates much better with solar wind parameters downstream of a shock (correlation coefficient, r, up to 0.86) than solar wind parameters upstream of a shock (r up to 0.6). Therefore whether or not an interplanetary shock can "induce'' a magnetic bay depends on the concurrent solar wind and IMF conditions. This strongly suggests that enhancements of the westward auroral electrojet during magnetosphere compression are primarily associated with a directly driven process. It is also found that the solar wind dynamic pressure, which is traditionally considered a secondary effect, contributes equally with IMF B-z to the westward auroral electrojet. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Liou, K (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM kan.liou@jhuapl.edu; patrick.newell@jhuapl.edu; ching.meng@jhuapl.edu; wuc@cspar.uah.edu; rpl@lepvax.gsfc.nasa.gov RI Liou, Kan/C-2089-2016 OI Liou, Kan/0000-0001-5277-7688 NR 27 TC 18 Z9 22 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUN 22 PY 2004 VL 109 IS A6 AR A06306 DI 10.1029/2004JA010400 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 839IT UT WOS:000222778000005 ER PT J AU Manoharan, PK Gopalswamy, N Yashiro, S Lara, A Michalek, G Howard, RA AF Manoharan, PK Gopalswamy, N Yashiro, S Lara, A Michalek, G Howard, RA TI Influence of coronal mass ejection interaction on propagation of interplanetary shocks SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE shock waves; interplanetary shocks; coronal mass ejections ID EARTH; STORMS; SPEED; EVENT; WIND; 1-AU AB We studied 91 interplanetary (IP) shocks associated with coronal mass ejections (CMEs) originating within about +/-30degrees in longitude and latitude from the center of the Sun during 1997-2002. These CMEs cover a wide range of initial speeds of about 120 to 2400 kms(-1) and they also include a special population of 25 interacting CMEs. This study provides the characteristics of propagation effects of more number of high-speed CMEs (V-CME > 1500 kms(-1)) than the data used in earlier studies. It enables to extend the shock-arrival prediction model to high-speed CMEs. The results on comparison of IP shock speed and transit time at 1 AU suggest that the shock transit time is not controlled by its final speed but is primarily determined by the initial speed of the CME and effects encountered by it during the propagation. It is found that the CME interaction tends to slow the shock and associated CME. The deviations of shock arrival times from the empirical model are considerably large for slow (V-CME < 300 kms(-1)) and fast (V-CME > 800 kms(-1)) CMEs. Results show that the slow and fast CMEs experience stronger effective acceleration. C1 Catholic Univ Amer, Ctr Solar Phys & Space Weather, Washington, DC 20017 USA. Tata Inst Fundamental Res, Radio Astron Ctr, Ooty, Udhagamandalam, India. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico. Jagiellonian Univ, Astron Observ, Krakow, Poland. USN, Div Space Sci, Res Lab, Washington, DC 20375 USA. RP Manoharan, PK (reprint author), Catholic Univ Amer, Ctr Solar Phys & Space Weather, Washington, DC 20017 USA. EM mano@cspsw3.gsfc.nasa.gov; gopals@fugee.gsfc.nasa.gov RI Gopalswamy, Nat/D-3659-2012; OI Lara, Alejandro/0000-0001-6336-5291; Manoharan, Periasamy K/0000-0003-4274-211X NR 21 TC 74 Z9 81 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 2004 VL 109 IS A6 AR A06109 DI 10.1029/2003JA010300 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 839IT UT WOS:000222778000003 ER PT J AU Bassim, ND Twigg, ME Eddy, CR Henry, RL Holm, RT Culbertson, JC Stahlbush, RE Neudeck, PG Trunek, AJ Powell, JA AF Bassim, ND Twigg, ME Eddy, CR Henry, RL Holm, RT Culbertson, JC Stahlbush, RE Neudeck, PG Trunek, AJ Powell, JA TI Microstructure of heteroepitaxial GaN grown on mesa-patterned 4H-SiC substrates SO APPLIED PHYSICS LETTERS LA English DT Article ID SURFACES AB Cross-sectional transmission electron microscopy and atomic force microscopy have been used to study the microstructure of a thin heteroeptiaxial GaN film grown on (0001) 4H-SiC mesa surfaces with and without atomic scale steps. Analysis of a mesa that was completely free of atomic-scale surface steps prior to III-N film deposition showed that these GaN layers had a wide variation in island height (1-3 mum) and included the presence of pit-like defects on the film surface. This sample had a low dislocation density (5x10(8)/cm(2)) as compared to conventionally grown samples on unpatterned (0001) on-axis 4H-SiC (2x10(9)/cm(2)), coupled with a 3-5 times increase in grain size. A comparison of a GaN film on the step-free 4H-SiC mesa region with a GaN film on a stepped 4H-SiC mesa region on the same substrate showed that the presence of surface steps reduced the overall grain size of the film from 7-10 mum to a grain size of about 2-3 mum. Since the GaN films grow via a Volmer-Weber mechanism, a decrease in the number of heterogeneous nucleation sites may allow the growth of large GaN islands before coalescence, thus reducing the number of threading dislocations. These results are promising for the further development of unique, low-dislocation density active regions for GaN device structures on 4H-SiC. 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 Bassim, ND (reprint author), USN, Res Lab, Elect Sci & Technol Div, Washington, DC 20375 USA. EM nbass@estd.nrl.navy.mil NR 9 TC 10 Z9 10 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 21 PY 2004 VL 84 IS 25 BP 5216 EP 5218 DI 10.1063/1.1765213 PG 3 WC Physics, Applied SC Physics GA 830HD UT WOS:000222111800050 ER PT J AU Wise, KE Park, C Siochi, EJ Harrison, JS AF Wise, KE Park, C Siochi, EJ Harrison, JS TI Stable dispersion of single wall carbon nanotubes in polyimide: the role of noncovalent interactions SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; ABSORPTION-SPECTROSCOPY; ELECTRONIC-PROPERTIES; RAMAN-SCATTERING; ELECTRONEGATIVITY; MOLECULES; PRISTINE; BUNDLES; STATES; FILMS AB Single wall carbon nanotubes (SWNTs) have been dispersed in a nitrile functionalized polyimide matrix and the resulting composite shows excellent stability with respect to reaggregation of the nanotubes. This contrasts with the behaviour of structurally similar polyimides in which the dispersion is only stable for short periods of time. Shifts in certain characteristic FTIR and Raman peaks which indicate a charge transfer interaction between the nanotubes and polymer matrix are observed. A simple model for charge transfer stabilization is presented and shown to be consistent with the experimental observations. (C) 2004 Elsevier B.V. All rights reserved. C1 Natl Inst Aerosp, Hampton, VA USA. NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23665 USA. RP Wise, KE (reprint author), Natl Inst Aerosp, Hampton, VA USA. EM k.e.wise@larc.nasa.gov NR 31 TC 126 Z9 127 U1 2 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 21 PY 2004 VL 391 IS 4-6 BP 207 EP 211 DI 10.1016/j.cplett.2004.04.096 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 831WU UT WOS:000222228000002 ER PT J AU Lu, YJ Li, J Han, J Ng, HT Binder, C Partridge, C Meyyappan, M AF Lu, YJ Li, J Han, J Ng, HT Binder, C Partridge, C Meyyappan, M TI Room temperature methane detection using palladium loaded single-walled carbon nanotube sensors SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GAS; ADSORPTION AB Single-walled carbon nanotubes (SWNTs) loaded with palladium (Pd) nanoparticles are used for detection of methane ranging from 6 to 100 ppm in air at room temperature. The Pd-SWNT nanosensors show advantages over conventional catalytic beads and metal oxide sensors for methane detection in terms of reduced size and power consumption by a factor of 100 and sensitivity by a factor of 10. A charge transfer sensing mechanism in which Pd attracts electrons from SWNTs to form a weakly bound complex Pddelta+(CH4)(delta-) is discussed. In addition, the elevated temperature and ultraviolet light effects on the sensor characteristics are also studied. (C) 2004 Published by Elsevier B.V. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Li, J (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, MS 299-1, Moffett Field, CA 94035 USA. EM jingli@mail.arc.nasa.gov NR 16 TC 196 Z9 200 U1 4 U2 64 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 21 PY 2004 VL 391 IS 4-6 BP 344 EP 348 DI 10.1016/j.cplett.2004.05.029 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 831WU UT WOS:000222228000027 ER PT J AU Turyshev, SG Shao, M Nordtvedt, K AF Turyshev, SG Shao, M Nordtvedt, K TI The laser astrometric test of a relativity mission SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID SOLAR GRAVITATIONAL DEFLECTION; POST-NEWTONIAN FORMALISM; ANGULAR POWER SPECTRUM; TENSOR-SCALAR THEORIES; GENERAL-RELATIVITY; EQUIVALENCE PRINCIPLE; MASSIVE BODIES; 2ND-ORDER CONTRIBUTIONS; GRAVITY; LIGHT AB This paper discusses the motivation and general design elements of a new fundamental physics experiment that will test relativistic gravity at the accuracy better than the effects of the second order in the gravitational field strength, alphaG(2). The laser astrometric test of relativity (LATOR) mission uses laser interferometry between two micro-spacecraft whose lines of sight pass close by the Sun to accurately measure deflection of light in the solar gravity. The key element of the experimental design is a redundant geometry optical truss provided by a long-baseline (100 m) multi-channel stellar optical interferometer placed on the International Space Station (ISS). The spatial interferometer is used for measuring the angles between the two spacecraft and for orbit determination purposes. In Euclidean geometry, determination of a triangle's three sides determines any angle therein; with gravity changing the optical lengths of sides passing close by the Sun and deflecting the light, the Euclidean relationships are overthrown. The geometric redundancy enables LATOR to measure the departure from Euclidean geometry caused by the solar gravity field to a very high accuracy. LATOR will not only improve the value of the parametrized post-Newtonian (PPN) parameter gamma to unprecedented levels of accuracy of 1 part in 108, it will also reach the ability to measure effects of the next post-Newtonian order (alphaG(2)) of light deflection resulting from gravity's intrinsic nonlinearity. The solar quadrupole moment parameter, J(2), will be measured with high precision, as well as a variety of other relativistic effects including Lense-Thirring precession. LATOR will lead to very robust advances in the tests of fundamental physics: this mission could discover a violation or extension of general relativity, or reveal the presence of an additional long range interaction in the physical law. There are no analogues to the LATOR experiment; it is unique and is a natural culmination of solar system gravity experiments. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NW Anal, Bozeman, MT 59715 USA. RP Turyshev, SG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM turyshev@jpl.nasa.gov NR 81 TC 63 Z9 64 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 EI 1361-6382 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD JUN 21 PY 2004 VL 21 IS 12 BP 2773 EP 2799 AR PII S0264-9381(04)71628-7 DI 10.1088/0264-9381/21/12/001 PG 27 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 832CT UT WOS:000222245500002 ER PT J AU Korb, CL Weng, CY AF Korb, CL Weng, CY TI Effective frequency technique for finite spectral bandwidth effects SO APPLIED OPTICS LA English DT Article ID ABSORPTION LIDAR TECHNIQUE AB A technique that uses a single effective frequency to represent the effects of finite spectral bandwidth for 4 active and passive measurements centered on an absorption line, a trough region, or a slowly varying 4 spectral feature is described. For Gaussian and rectangular instrumental line shapes, the effective frequency is shown to have a simple form that depends only on the instrumental line shape and bandwidth and not on the absorption line profile. The technique is applicable to a large class of active and passive measurements and simulations in both the laboratory and the atmosphere. Simulations show that the technique yields accuracies better than 0.1% for bandwidths less than 0.2 times the atmospheric linewidth for a rectangular line shape or better than 0.2% for a Gaussian. (C) 2004 Optical Society of America. C1 NASA, Goddard Space Flight Ctr, Lab Atmospheres, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Seabrook, MD 20706 USA. RP NASA, Goddard Space Flight Ctr, Lab Atmospheres, Code 912, Greenbelt, MD 20771 USA. EM korb@agnes.gsfc.nasa.gov NR 10 TC 2 Z9 2 U1 0 U2 8 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD JUN 20 PY 2004 VL 43 IS 18 BP 3747 EP 3751 DI 10.1364/AO.43.003747 PG 5 WC Optics SC Optics GA 829RV UT WOS:000222068300022 PM 15218617 ER PT J AU Chen, A Reyes, LC Ritz, S AF Chen, A Reyes, LC Ritz, S TI Detecting the attenuation of blazar gamma-ray emission by extragalactic background light with the gamma-ray large area space telescope SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; gamma rays : observations; instrumentation : detectors; intergalactic medium ID EGRET OBSERVATIONS; GALAXY FORMATION; 1ST DETECTIONS; 8000 ANGSTROM; ABSORPTION; SCIENCE AB Gamma rays with energy above 10 GeV interact with optical-UV photons, resulting in pair production. Therefore, a large sample of high-redshift sources of these gamma rays can be used to probe the extragalactic background starlight (EBL) by examining the redshift dependence of the attenuation of the flux above 10 GeV. The Gamma-Ray Large Area Space Telescope (GLAST), the next-generation high-energy gamma-ray telescope, will have the unique capability to detect thousands of gamma-ray blazars to redshifts of at least z = 4, with sufficient angular resolution to allow identification of a large fraction of their optical counterparts. By combining established models of the gamma-ray blazar luminosity function, two different calculations of the high-energy gamma-ray opacity due to EBL absorption, and the expected GLAST instrument performance to produce simulated fluxes and redshifts for the blazars. that GLAST would detect, we demonstrate that these gamma-ray blazars have the potential to be a highly effective probe of the optical-UV EBL. C1 Consorzio Interuniv Fis Spaziale, I-10133 Turin, Italy. Ist Astrofis Spaziale & Fis Cosm, Sez Milano, I-20133 Milan, Italy. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, College Pk, MD 20742 USA. RP Chen, A (reprint author), Consorzio Interuniv Fis Spaziale, I-10133 Turin, Italy. EM chen@mi.iasf.cnr.it NR 18 TC 27 Z9 28 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2004 VL 608 IS 2 BP 686 EP 691 DI 10.1086/383456 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 831HA UT WOS:000222184300007 ER PT J AU Beckmann, V Favre, P Tavecchio, F Bussien, T Fliri, J Wolter, A AF Beckmann, V Favre, P Tavecchio, F Bussien, T Fliri, J Wolter, A TI The gamma-ray bright BL Lacertae object RX J1211+2242 SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : general; BL Lacertae objects : individual (RX J1211+2242); gamma rays : observations ID ACTIVE GALACTIC NUCLEI; X-RAY; LAC OBJECTS; INTRADAY VARIABILITY; ASTRONOMY MISSION; EGRET CATALOG; SKY SURVEY; BLAZARS; ABSORPTION; BEPPOSAX AB RX J1211+2242 is an optically faint (B similar or equal to 19.2 mag) but X-ray bright (f(2-10) (keV) = 5 x 10(-12) ergs cm(-2) s(-1)) active galactic nucleus (AGN) that has been shown to be a BL Lac object at redshift z = 0.455. The ROSAT X-ray, Calar Alto optical, and NRAO VLA Sky Survey (NVSS) radio data suggest that the peak of the synchrotron emission of this object is at energies as high as several keV. BeppoSAX observations have been carried out simultaneously with optical observations in order to extend the coverage to higher energies. The new data indeed indicate a turnover in the 2-10 keV energy region. We propose that RX J1211+2242 is the counterpart of the unidentified EGRET source 3EG J1212+2304, making it a gamma-ray emitter with properties similar to, e.g., Mrk 501 in its bright state, although at a much larger distance. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland. Observ Geneva, CH-1290 Sauverny, Switzerland. Osserv Astron Brera, I-22807 Merate, Italy. Ecole Polytech Fed Lausanne, CH-1015 Lausanne, Switzerland. Univ Sternwarte, D-81679 Munich, Germany. Osserv Astron Brera, I-20121 Milan, Italy. RP Beckmann, V (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM beckmann@milkyway.gsfc.nasa.gov OI Wolter, Anna/0000-0001-5840-9835 NR 41 TC 1 Z9 1 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2004 VL 608 IS 2 BP 692 EP 697 DI 10.1086/420815 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 831HA UT WOS:000222184300008 ER PT J AU Grego, L Vrtilek, JM Van Speybroeck, L David, LP Forman, W Carlstrom, JE Reese, ED Joy, MK AF Grego, L Vrtilek, JM Van Speybroeck, L David, LP Forman, W Carlstrom, JE Reese, ED Joy, MK TI A deep Chandra observation of the distant galaxy cluster MS 1137.5+6625 SO ASTROPHYSICAL JOURNAL LA English DT Article ID MEDIUM-SENSITIVITY SURVEY; X-RAY-CLUSTERS; MICROWAVE BACKGROUND ANISOTROPY; COLD DARK-MATTER; HIGH-REDSHIFT CLUSTERS; GAS MASS FRACTIONS; HUBBLE CONSTANT; COSMOLOGICAL PARAMETERS; INTRACLUSTER MEDIUM; CL 0016+16 AB We present results from a deep Chandra observation of MS 1137.5+66, a distant (z = 0.783) and massive cluster of galaxies. Only a few similarly massive clusters are currently known at such high redshifts; accordingly, this observation provides much needed information on the dynamical state of these rare systems. The cluster appears both regular and symmetric in the X-ray image. However, our analysis of the spectral and spatial X-ray data in conjunction with interferometric Sunyaev-Zel'dovich effect data and published deep optical imaging suggests that the cluster has a fairly complex structure. The angular diameter distance we calculate from the Chandra and Sunyaev-Zei'dovich effect data assuming an isothermal, spherically symmetric cluster implies a low value for the Hubble constant for which we explore possible explanations. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. RP Grego, L (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM lgrego@cfa.harvard.edu; ldavid@cfa.harvard.edu; wforman@cfa.harvard.edu; rcese@efpa.bcrkeley.edu; marshall.joy@msfc.nasa.gov OI Forman, William/0000-0002-9478-1682 NR 68 TC 4 Z9 4 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2004 VL 608 IS 2 BP 731 EP 741 DI 10.1086/420687 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 831HA UT WOS:000222184300011 ER PT J AU Grady, CA Woodgate, B Torres, CAO Apai, THD Rodmann, J Wang, HC Stecklum, B Linz, H Williger, GM Brown, A Wilkinson, E Harper, GM Herczeg, GJ Danks, A Vieira, GL Malumuth, E Collins, NR Hill, RS AF Grady, CA Woodgate, B Torres, CAO Apai, THD Rodmann, J Wang, HC Stecklum, B Linz, H Williger, GM Brown, A Wilkinson, E Harper, GM Herczeg, GJ Danks, A Vieira, GL Malumuth, E Collins, NR Hill, RS TI The environment of the optically brightest Herbig Ae star, HD 104237 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; ISM : Herbig-Haro objects; ISM : individual (HH 669); ISM : jets and outflows; planetary systems : protoplanetary disks; stars : individual (HD 104237); stars : pre-main-sequence ID TELESCOPE IMAGING SPECTROGRAPH; INTERMEDIATE-MASS STARS; T-TAURI-STARS; HUBBLE-SPACE-TELESCOPE; ETA-CHAMAELEONTIS CLUSTER; EMISSION-LINE GALAXIES; AE/BE STARS; BETA-PICTORIS; HIGH-RESOLUTION; CIRCUMSTELLAR DISKS AB We investigate the environment of the nearest Herbig Ae star, HD 104237, with a multiwavelength combination of optical coronagraphic, near-IR, and mid-IR imaging supported by optical, UV, and far-ultraviolet spectroscopy. We confirm the presence of T Tauri stars associated with the Herbig Ae star HD 104237, noted by Feigelson et al. We find that two of the stars within 15" of HD 104237 have IR excesses, potentially indicating the presence of circumstellar disks, in addition to the Herbig Ae star itself. We derive a new spectral type of A7.5Ve-A8Ve for HD 104237 and find log (L/L-circle dot,) = 1.39. With these data, HD 104237 has an age of t approximate to 5 Myr, in agreement with the estimates for the other members of the association. HD 104237 is still actively accreting, with a conspicuous UV/far-UV excess seen down to 1040 A, and is driving a bipolar microjet termed HH 669. This makes it the second, older Herbig Ae star now known to have a microjet. The presence of the microjet enables us to constrain the circumstellar disk to r less than or equal to 0."6 (70 AU) with an inclination angle of i = 18degrees(-11)(+14) from pole-on. The absence of a spatially extended continuum and fluorescent H-2 emission near Lyalpha. is in agreement with the prediction of shadowed disk models for the IR spectral energy distribution. With the high spatial density of disks in this group of stars, proximity, and minimal reddening, HD 104237 and its companions should serve as ideal laboratories for probing the comparative evolution of planetary systems. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. MCT, Lab Nacl Astrofis, BR-37504364 Itajuba, Brazil. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Acad Sinica, Purple Mt Observ, Nanjing 210008, Peoples R China. EM cgrady@echelle.gsfc.nasa.gov; beto@lna.br NR 92 TC 62 Z9 62 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2004 VL 608 IS 2 BP 809 EP 830 DI 10.1086/420763 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 831HA UT WOS:000222184300018 ER PT J AU Kouveliotou, C Woosley, SE Patel, SK Levan, A Blandford, R Ramirez-Ruiz, E Wijers, RAMJ Weisskopf, MC Tennant, A Pian, E Giommi, P AF Kouveliotou, C Woosley, SE Patel, SK Levan, A Blandford, R Ramirez-Ruiz, E Wijers, RAMJ Weisskopf, MC Tennant, A Pian, E Giommi, P TI Chandra observations of the X-ray environs of SN 1998bw/GRB 980425 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; supernovae : individual (SN 1998bw); X-rays : individual (GRB 980425) ID 25 APRIL 1998; SUPERNOVA SN 1998BW; SPLIT-PIXEL EVENTS; BURST AFTERGLOWS; RADIO-EMISSION; GRB 980425; SPATIAL-RESOLUTION; BEAMED AFTERGLOW; ENERGY RESERVOIR; NORMAL GALAXIES AB We report X-ray studies of the environs of SN 1998bw and GRB 980425 using the Chandra X-Ray Observatory 1281 days after the gamma-ray burst (GRB). Eight X-ray point sources were localized, three and five each in the original error boxes, S1 and S2, assigned for variable X-ray counterparts to the GRB by BeppoSAX. The sum of the discrete X-ray sources plus continuous emission in S2 observed by Chandra on day 1281 is within a factor of 1.5 of the maximum and the upper limits seen by BeppoSAX. We conclude that S2 is the sum of several variable sources that have not disappeared and therefore is not associated with the GRB. Within S1, clear evidence is seen for a decline of approximately a factor of 12 between day 200 and day 1281. One of the sources in S 1, S I a, is coincident with the well-determined radio location of SN 1998bw and is certainly the remnant of that explosion. The nature of the other sources is also discussed. Combining our observation of the supernova with others of the GRB afterglow, a smooth X-ray light curve, spanning similar to1400 days, is obtained by assuming that the burst and supernova were coincident at 35.6 Mpc. When this X-ray light curve is compared with those of the X-ray "afterglows" of ordinary GRBs, X-ray flashes, and ordinary supernovae, evidence emerges for at least two classes of light curves, perhaps bounding a continuum. By 3-10 yr, all these phenomena seem to converge on a common X-ray luminosity, possibly indicative of the supernova underlying them all. This convergence strengthens the conclusion that SN 1998bw and GRB 980425 took place in the same object. One possible explanation for the two classes is that a (nearly) standard GRB was observed at different angles, in which case X-ray afterglows with intermediate luminosities should eventually be discovered. Finally, we comment on the contribution of GRB afterglows to the ultraluminous X-ray source population. C1 NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Univ Space Res Assoc, NSSTC, Huntsville, AL 35805 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA. Inst Adv Study, Princeton, NJ 08540 USA. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Univ Amsterdam, Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. Osserv Astron Trieste, INAF, I-34131 Trieste, Italy. ESRIN, ASI Sci Data Ctr, I-00044 Frascati, Italy. RP Kouveliotou, C (reprint author), NASA, George C Marshall Space Flight Ctr, NSSTC, SD-50,320 Sparkman Dr, Huntsville, AL 35805 USA. EM chryssa.kouveliotou@nasa.gov OI giommi, paolo/0000-0002-2265-5003; Wijers, Ralph/0000-0002-3101-1808; Pian, Elena/0000-0001-8646-4858 NR 76 TC 59 Z9 60 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2004 VL 608 IS 2 BP 872 EP 882 DI 10.1086/420878 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 831HA UT WOS:000222184300022 ER PT J AU Kosack, K Badran, HM Bond, IH Boyle, PJ Bradbury, SM Buckley, JH Carter-Lewis, DA Celik, O Connaughton, V Cui, W Daniel, M D'Vall, M Perez, IDL Duke, C Falcone, A Fegan, DJ Fegan, SJ Finley, JP Fortson, LF Gaidos, JA Gammell, S Gibbs, K Gillanders, GH Grube, J Gutierrez, K Hall, J Hall, TA Hanna, D Hillas, AM Holder, J Horan, D Jarvis, A Jordan, M Kenny, GE Kertzman, M Kieda, D Kildea, J Knapp, J Krawczynski, H Krennrich, F Lang, MJ Le Bohec, S Linton, E Lloyd-Evans, J Milovanovic, A McEnery, J Moriarty, R Muller, D Nagai, T Nolan, S Ong, RA Pallassini, R Petry, D Power-Mooney, B Quinn, J Quinn, M Ragan, K Rebillot, P Reynolds, PT Rose, HJ Schroedter, M Sembroski, GH Swordy, SP Syson, A Vassiliev, VV Wakely, SP Walker, G Weekes, TC Zweerink, J AF Kosack, K Badran, HM Bond, IH Boyle, PJ Bradbury, SM Buckley, JH Carter-Lewis, DA Celik, O Connaughton, V Cui, W Daniel, M D'Vall, M Perez, IDL Duke, C Falcone, A Fegan, DJ Fegan, SJ Finley, JP Fortson, LF Gaidos, JA Gammell, S Gibbs, K Gillanders, GH Grube, J Gutierrez, K Hall, J Hall, TA Hanna, D Hillas, AM Holder, J Horan, D Jarvis, A Jordan, M Kenny, GE Kertzman, M Kieda, D Kildea, J Knapp, J Krawczynski, H Krennrich, F Lang, MJ Le Bohec, S Linton, E Lloyd-Evans, J Milovanovic, A McEnery, J Moriarty, R Muller, D Nagai, T Nolan, S Ong, RA Pallassini, R Petry, D Power-Mooney, B Quinn, J Quinn, M Ragan, K Rebillot, P Reynolds, PT Rose, HJ Schroedter, M Sembroski, GH Swordy, SP Syson, A Vassiliev, VV Wakely, SP Walker, G Weekes, TC Zweerink, J TI Tev Gamma-ray observations of the galactic center SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; Galaxy : center; Galaxy : nucleus; gamma rays : observations ID SUPERMASSIVE BLACK-HOLE; SAGITTARIUS-A-ASTERISK; DARK-MATTER HALOS; MILKY-WAY; ANNIHILATION; EMISSION; DIRECTION; SPECTRA; FLARE; EAST AB We report a possible detection of TeV gamma rays from the Galactic center by the Whipple 10 m gamma-ray telescope. Twenty-six hours of data were taken over an extended period from 1995 through 2003 resulting in a total significance of 3.7 sigma. The measured excess corresponds to an integral flux of 1.6 x 10(-8) +/- 0.5 x 10(-8) (stat) +/- 0.3 x 10(-8) (sys) photons m(-2) s(-1) above an energy of 2.8 TeV, roughly 40% of the flux from the Crab Nebula at this energy. The 95% confidence region has an angular extent of about 15' and includes the position of Sgr A*. The detection is consistent with a point source and shows no evidence of variability. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. Tanta Univ, Dept Phys, Tanta, Egypt. Univ Leeds, Dept Phys, Leeds LS2 9JT, W Yorkshire, England. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Gamma Ray Astrophys Grp Natl Space Sci, Huntsville, AL USA. Ctr Technol, Huntsville, AL USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Grinnell Coll, Dept Phys, Grinnell, IA 50112 USA. Natl Univ Ireland Univ Coll Dublin, Dept Expt Phys, Dublin 4, Ireland. Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Adler Planetarium, Dept Astron, Chicago, IL 60605 USA. Astron Museum, Chicago, IL 60605 USA. Natl Univ Ireland Univ Coll Galway, Dept Phys, Galway, Ireland. Univ Utah, High Energy Astrophys Inst, Salt Lake City, UT 84112 USA. Univ Arkansas, Dept Phys & Astron, Little Rock, AR 72204 USA. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. Depauw Univ, Dept Phys & Astron, Greencastle, IN 46135 USA. Univ Maryland Baltimore Cty, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Mayo Inst Technol, Sch Sci, Galway, Ireland. Cork Inst Technol, Dept Appl Phys & Instrumentat, Cork, Ireland. RP Kosack, K (reprint author), Washington Univ, Dept Phys, Campus Box 1105, St Louis, MO 63130 USA. EM buckley@wuphys.wustl.edu RI McEnery, Julie/D-6612-2012; Hall, Jeter/F-6108-2013; Hall, Jeter/E-9294-2015; Daniel, Michael/A-2903-2010; OI Daniel, Michael/0000-0002-8053-7910; Cui, Wei/0000-0002-6324-5772; Knapp, Johannes/0000-0003-1519-1383; Lang, Mark/0000-0003-4641-4201 NR 30 TC 147 Z9 147 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 2004 VL 608 IS 2 BP L97 EP L100 DI 10.1086/422469 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 831HB UT WOS:000222184400006 ER PT J AU Verner, EM Peterson, BA AF Verner, EM Peterson, BA TI Elucidating the correlation of the quasar FeII/MgII ratio with redshift SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; line : formation; methods : numerical; quasars : emission lines ID FE-II EMISSION; IRON EMISSION; STAR-FORMATION; QSOS; EVOLUTION; SPECTRA; NUCLEI; Z=3.62; LINES; ATLAS AB Interpretation of the Fe II(UV)/Mg II emission ratios from quasars has a major cosmological motivation. Both Fe and Mg are produced by short-lived massive stars. In addition, Fe is produced by accreting white dwarf supernovae somewhat after star formation begins. Therefore, we expect that the Fe/Mg ratio will gradually decrease with redshift. We have used data from the Sloan Digital Sky Survey to explore the dependence of the Fe II(UV)/ Mg II ratio on redshift and on luminosity in the redshift range of 0.75 < z < 2.20, and we have used predictions from our 830-level model for the Fe II atom in photoionization calculations to interpret our findings. We have split the quasars into several groups based on the value of their Fe ii(UV)/Mg ii emission ratios and then checked to see how the fraction of quasars in each group varies with the increase, of redshift. We next examined the luminosity dependence of the Fe II(UV)/Mg II ratio, and we found that beyond a threshold of Fe II(UV)/Mg II = 5, and M-2500 < -25 mag, the Fe II(UV)/Mg II ratio increases with luminosity, as predicted by our model. We interpret our observed variation of the Fe ii(UV)/Mg it ratio with redshift as a result of the correlation of redshift with luminosity in a magnitude-limited quasar sample. C1 Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia. RP Verner, EM (reprint author), Catholic Univ Amer, Inst Astrophys & Computat Sci, 200 Hannan Hall, Washington, DC 20064 USA. EM kverner@fe2.gsfc.nasa.gov; peterson@mso.anu.edu.au NR 23 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 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2004 VL 608 IS 2 BP L85 EP L88 DI 10.1086/422389 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 831HB UT WOS:000222184400003 ER PT J AU Whiteman, DN Demoz, B Wang, Z AF Whiteman, DN Demoz, B Wang, Z TI Subtropical cirrus cloud extinction to backscatter ratios measured by Raman Lidar during CAMEX-3 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPICAL CIRRUS; OPTICAL-PROPERTIES; WATER-VAPOR; RADIATIVE IMPACTS; COLD CIRRUS; MIDLATITUDE; RETURNS; DEPOLARIZATION; CLIMATOLOGY; PARTICLES AB The NASA/GSFC Scanning Raman Lidar was stationed on Andros Island, Bahamas for the third Convection and Moisture Experiment (CAMEX 3) held in August September, 1998 and acquired an extensive set of cirrus cloud measurements [Whiteman et al., 2001]. Distinct differences in the optical properties of the clouds are found when the cirrus are hurricane-induced versus non-hurricane-induced. Hurricane-induced cirrus clouds are found to generally possess lower values of extinction-to-backscatter ratio (S) than non-hurricane-induced clouds. Comparison of the S measurements made here with those of other studies reveal at times large differences. Given that S is often a required parameter for space-based retrievals of cloud optical depth using backscatter lidar, these large differences in S measurements imply difficulties in developing a parameterization of S for use in space-based lidar retrievals. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Baltimore, MD 21201 USA. RP NASA, Goddard Space Flight Ctr, Code 913, Greenbelt, MD 20771 USA. EM david.whiteman@gsfc.nasa.gov RI Wang, Zhien/F-4857-2011; Demoz, Belay/N-4130-2014 NR 29 TC 21 Z9 21 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 19 PY 2004 VL 31 IS 12 AR L12105 DI 10.1029/2004GL020003 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 854FJ UT WOS:000223886500007 ER PT J AU Smith, NV Saatchi, SS Randerson, JT AF Smith, NV Saatchi, SS Randerson, JT TI Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE remote sensing; soil freeze-thaw; northern latitudes ID SPECIAL SENSOR MICROWAVE/IMAGER; VEGETATION INDEX DATA; SEA-ICE PARAMETERS; INTERANNUAL VARIABILITY; SPATIAL-RESOLUTION; ATMOSPHERIC CO2; CARBON-DIOXIDE; SEASONAL CYCLE; TIME-SERIES; SNOW COVER AB [1] In boreal and tundra ecosystems the freeze state of soils limits rates of photosynthesis and respiration. Here we develop a technique to identify the timing of freeze and thaw transitions of high northern latitude land areas using satellite data from the Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I). Our results indicate that in Eurasia there was a trend toward earlier thaw dates in tundra ( - 3.3 +/- 1.8 days/decade) and larch biomes ( - 4.5 +/- 1.8 days/ decade) over the period 1988 - 2002. In North America there was a trend toward later freeze dates in evergreen conifer forests by 3.1 +/- 1.2 days/ decade that led, in part, to a lengthening of the growing season by 5.1 +/- 2.9 days/ decade. The growing season length in North American tundra increased by 5.4 +/- 3.1 days/ decade. Despite the trend toward earlier thaw dates in Eurasian larch forests, the growing season length did not increase because of parallel changes in timing of the fall freeze ( - 5.4 +/- 2.1 days/ decade), which led to a forward shift of the growing season. Thaw timing was negatively correlated with surface air temperatures in the spring, whereas freeze timing was positively correlated with surface air temperatures in the fall, suggesting that surface air temperature is one of several factors that determines the timing of soil thaw and freeze. The high spatial resolution, frequent temporal coverage, and duration of the SMMR and SSM/I satellite records makes them suitable for rigorous time series analysis and change detection in northern terrestrial ecosystems. C1 CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. RP Smith, NV (reprint author), CALTECH, MS 100-23, Pasadena, CA 91125 USA. EM nicolev@gps.caltech.edu NR 56 TC 64 Z9 67 U1 2 U2 28 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 19 PY 2004 VL 109 IS D12 AR D12101 DI 10.1029/2003JD004472 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 854FL UT WOS:000223886700003 ER PT J AU Brownlee, DE Horz, F Newburn, RL Zolensky, M Duxbury, TC Sandford, S Sekanina, Z Tsou, P Hanner, MS Clark, BC Green, SF Kissel, J AF Brownlee, DE Horz, F Newburn, RL Zolensky, M Duxbury, TC Sandford, S Sekanina, Z Tsou, P Hanner, MS Clark, BC Green, SF Kissel, J TI Surface of young Jupiter family comet 81 P/Wild 2: View from the Stardust spacecraft SO SCIENCE LA English DT Article ID NUCLEUS; MORPHOLOGY AB Images taken by the Stardust mission during its flyby of 81P/Wild 2 show the comet to be a 5-kilometer oblate body covered with remarkable topographic features, including unusual circular features that appear to be impact craters. The presence of high-angle slopes shows that the surface is cohesive and self-supporting. The comet does not appear to be a rubble pile, and its rounded shape is not directly consistent with the comet being a fragment of a larger body. The surface is active and yet it retains ancient terrain. Wild 2 appears to be in the early stages of its degradation phase as a small volatile-rich body in the inner solar system. C1 Univ Washington, Dept Astron, Seattle, WA 98195 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Massachusetts, Amherst, MA 01003 USA. Lockheed Martin Astronaut, Denver, CO 80201 USA. Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. RP Brownlee, DE (reprint author), Univ Washington, Dept Astron, Seattle, WA 98195 USA. EM brownlee@astro.washington.edu RI Green, Simon/C-7408-2009 NR 20 TC 202 Z9 204 U1 1 U2 5 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 18 PY 2004 VL 304 IS 5678 BP 1764 EP 1769 DI 10.1126/science.1097899 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 829YU UT WOS:000222089500035 PM 15205524 ER PT J AU Sekanina, Z Brownlee, DE Economou, TE Tuzzolino, AJ Green, SF AF Sekanina, Z Brownlee, DE Economou, TE Tuzzolino, AJ Green, SF TI Modeling the nucleus and jets of comet 81 P/Wild 2 based on the Stardust encounter data SO SCIENCE LA English DT Article ID ROTATION; COMA AB We interpret the nucleus properties and jet activity from the Stardust spacecraft imaging and the onboard dust monitoring system data. Triangulation of 20 jets shows that 2 emanate from the nucleus dark side and 16 emanate from sources that are on slopes where the Sun's elevation is greater than predicted from the fitted triaxial ellipsoid. Seven sources, including five in the Mayo depression, coincide with relatively bright surface spots. Fitting the imaged jets, the spikelike temporal distribution of dust impacts indicates that the spacecraft crossed thin, densely populated sheets of particulate ejecta extending from small sources on the rotating nucleus, consistent with an emission cone model. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Chicago, Enrico Fermi Inst, Lab Astrophys & Space Res, Chicago, IL 60637 USA. Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. RP Sekanina, Z (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM zs@sek.jpl.nasa.gov RI Green, Simon/C-7408-2009 NR 16 TC 77 Z9 77 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 18 PY 2004 VL 304 IS 5678 BP 1769 EP 1774 DI 10.1126/science.1098388 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 829YU UT WOS:000222089500036 PM 15205525 ER PT J AU Tuzzolino, AJ Economou, TE Clark, BC Tsou, P Brownlee, DE Green, SF McDonnell, JAM McBride, N Colwell, MTSH AF Tuzzolino, AJ Economou, TE Clark, BC Tsou, P Brownlee, DE Green, SF McDonnell, JAM McBride, N Colwell, MTSH TI Dust measurements in the coma of comet 81P/Wild 2 by the Dust Flux Monitor Instrument SO SCIENCE LA English DT Article ID P/HALLEY; SPACECRAFT; 1P/HALLEY AB We present measurements of the dust particle flux and mass distribution from the Stardust Dust Flux Monitor Instrument (DFMI) throughout the flyby of comet 81P/Wild 2. In the particle mass regime from 10(-14) to 10(-7) kilograms, the spacecraft encountered regions of intense swarms of particles, together with bursts of activity corresponding to clouds of particles only a few hundred meters across. This fine-scale structure can be explained by particle fragmentation. We estimate that 2800+/-500 particles of diameter 15 micrometers or larger impacted the aerogel collectors, the largest being similar to6x10(-7) kilograms, which dominates the total collected mass. C1 Univ Chicago, Enrico Fermi Inst, Lab Astrophys & Space Res, Chicago, IL 60637 USA. Lockheed Martin Astronaut, Denver, CO 80201 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Washington, Dept Astron & Astrophys, Seattle, WA 98195 USA. Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. RP Economou, TE (reprint author), Univ Chicago, Enrico Fermi Inst, Lab Astrophys & Space Res, 9333 E 56th St, Chicago, IL 60637 USA. EM tecon@tecon.uchicago.edu RI Green, Simon/C-7408-2009 NR 20 TC 105 Z9 106 U1 1 U2 8 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 18 PY 2004 VL 304 IS 5678 BP 1776 EP 1780 DI 10.1126/science.1098759 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 829YU UT WOS:000222089500038 PM 15205527 ER PT J AU Khare, BN Wilhite, P Quinn, RC Chen, B Schingler, RH Tran, B Imanaka, H So, CR Bauschlicher, CW Meyyappan, M AF Khare, BN Wilhite, P Quinn, RC Chen, B Schingler, RH Tran, B Imanaka, H So, CR Bauschlicher, CW Meyyappan, M TI Functionalization of carbon nanotubes by ammonia glow-discharge: Experiments and modeling SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article AB We successfully functionalized single-walled carbon nanotubes (SWNTs) through a microwave discharge of ammonia. Evidence is supplied through Fourier transform infrared (FTIR) spectroscopy with band assignment aided by computational modeling. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy results also provide supporting evidence of functional groups attached to the surfaces of SWNTs from ammonia plasma. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Khare, BN (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM charles.w.bauschlicher@nasa.gov RI Imanaka, Hiroshi/E-7816-2012; OI So, Christopher/0000-0001-7572-778X NR 19 TC 76 Z9 77 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 17 PY 2004 VL 108 IS 24 BP 8166 EP 8172 DI 10.1021/jp049359q PG 7 WC Chemistry, Physical SC Chemistry GA 828HW UT WOS:000221965400014 ER PT J AU Ruzmaikin, A Feynman, J Jiang, X Noone, DC Waple, AM Yung, YL AF Ruzmaikin, A Feynman, J Jiang, X Noone, DC Waple, AM Yung, YL TI The pattern of northern hemisphere surface air temperature during prolonged periods of low solar output SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE-CHANGE; ARCTIC OSCILLATION; VARIABILITY; RECONSTRUCTIONS; IRRADIANCE; MODEL AB We show that the reconstructed sensitivity of the sea level temperature to long term solar forcing in the Northern Hemisphere is in very good agreement with the empirical temperature pattern corresponding to changes of the North Annular Mode (NAM). This implies that long-term variations of solar output affect climate predominantly through the NAM that extends throughout the stratosphere and troposphere. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Dept Geol & Planetary Sci, Pasadena, CA 91125 USA. STG Inc, Natl Climat Data Ctr, Asheville, NC 28801 USA. RP Ruzmaikin, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM aruzmaik@pop.jpl.nasa.gov; joan.feynman@jpl.nasa.gov; xun@gps.caltech.edu; dcn@gps.caltech.edu; anne.waple@noaa.gov; yly@gps.caltech.edu NR 18 TC 19 Z9 19 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 16 PY 2004 VL 31 IS 12 AR L12201 DI 10.1029/2004GL019955 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 833GL UT WOS:000222324800004 ER PT J AU Potter, C AF Potter, C TI Predicting climate change effects on vegetation, soil thermal dynamics, and carbon cycling in ecosystems of interior Alaska SO ECOLOGICAL MODELLING LA English DT Article DE vegetation dynamics; carbon cycle; boreal forest; tundra; ecosystem modeling ID SPRUCE/MOSS BOREAL FOREST; TANANA RIVER FLOODPLAIN; PLANT FUNCTIONAL TYPES; NET PRIMARY PRODUCTION; SOLAR-RADIATION; TEMPORAL VARIABILITY; ARCTIC VEGETATION; SIMULATION-MODEL; AIR-TEMPERATURE; HIGH-LATITUDES AB A dynamic vegetation model has been used to predict patterns of recent past and potential future change in taiga forest ecosystems of interior Alaska. The model, called CASA (Carnegie Ames Stanford Approach), is a process-based ecosystem depiction of plant and soil processes, including all major cycles of water and carbon. CASA's dynamic vegetation component is intended to facilitate coupling to general circulation models of the atmosphere, which require mechanistic fluxes and feedbacks from terrestrial vegetation. Simulation results for selected Alaska sites of Denali National Park suggest that the past 50-year climate trends of warming temperatures may shift the taiga ecosystem from dominance by evergreen needleleaf trees to a more mixed broadleaf-needleleaf tree composition. For other (higher elevation) areas of Denali, our model predicts that a difference of only about 3 degreesC in mean annual air temperatures appears to differentiate the permanent presence of tundra vegetation forms over taiga forest. The model predicts that over the 1950-1999 climate record at Denali station, the changing taiga ecosystems were net sinks for atmospheric CO2 of about 1.3 kg C m(-2). During the warm 1990s, these forests were predicted to be net carbon sinks of more than 15 g C m(-2) per year in 8 out of 10 years. Predicted NPP for the forest continues to increase with a projected warming trend for the next 25 years at a mean rate of about + 1.2 g C m(-2) per year. On the basis of these model results, a series of crucial field site measurements can be identified for inclusion in subsequent long-term ecological studies of the changing taiga forest. (C) 2003 Elsevier B.V. All rights reserved. C1 NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. RP Potter, C (reprint author), NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. EM cpotter@gaia.arc.nasa.gov NR 82 TC 33 Z9 43 U1 4 U2 31 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD JUN 15 PY 2004 VL 175 IS 1 BP 1 EP 24 DI 10.1016/j.ecolmodel.2003.05.004 PG 24 WC Ecology SC Environmental Sciences & Ecology GA 823CL UT WOS:000221587200001 ER PT J AU Liu, JP Yuan, XJ Martinson, DG Rind, D AF Liu, JP Yuan, XJ Martinson, DG Rind, D TI Re-evaluating Antarctic sea-ice variability and its teleconnections in a GISS global climate model with improved sea ice and ocean processes SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE Antarctic sea-ice variability; coupled global climate model; improved GISS/CGCM; teleconnections ID CIRCULATION MODELS; THERMODYNAMICS; SENSITIVITY; RESOLUTION; THICKNESS; DYNAMICS; EXTENT AB This study re-evaluated simulated Antarctic sea-ice variability and its teleconnections in a NASA Goddard Institute for Space Studies (GISS) coupled global climate model (CGCM) with improved sea-ice and ocean processes. With the improvements to the parameterizations of sea-ice dynamics and thermodynamics and of sub-grid-scale ocean processes, the new version of the GISS/CGCM does indeed do a better job in the representations of the local/regional ice-ocean interactions with regard to (1) the seasonal distributions of the Antarctic sea-ice edges (SIE), and (2) the vertical temperature and salinity structure in the upper Southern Ocean and surface air temperature (SAT) climatology in the southern high latitudes compared with the control version. However, these encouraging local/regional improvements do not extend to the simulations of the polar and extrapolar climate teleconnections. There is no obvious change to the simulations of the dominant spatial covarying patterns of the SAT variability on either the regional (southern high latitudes) or global scales. The simulated teleconnections between Antarctic SIE and global SAT still show the weak El Nino-southern oscillation like correlation pattern in the eastern tropical Pacific, though the new version generates a stronger tropical Indian component. Some dominant observed teleconnection patterns in the western extreme of the tropical Pacific and over the tropical continents (in-phase relationship between tropical South America and Africa) are still not well represented or are missed in the Antarctic SIE and global SAT lead/lag correlation maps and the empirical orthogonal function analysis on those correlation maps. The possible causes of the weak teleconnections in the improved GISS/CGCM are briefly discussed. Copyright (C) 2004 Royal Meteorological Society. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Earth & Environm Sci, Palisades, NY 10964 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RP Liu, JP (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, 311 Ferst Dr, Atlanta, GA 30332 USA. EM jliu@eas.gatech.edu RI LIU, JIPING/N-6696-2016 NR 24 TC 1 Z9 1 U1 0 U2 2 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 15 PY 2004 VL 24 IS 7 BP 841 EP 852 DI 10.1002/joc.1040 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 830FC UT WOS:000222106100004 ER EF