FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Stecker, FW Salamon, MH AF Stecker, FW Salamon, MH TI High energy neutrinos from quasars SO SPACE SCIENCE REVIEWS LA English DT Review ID ACTIVE GALACTIC NUCLEI; X-RAY VARIABILITY; RELATIVISTIC PROTONS; TIME VARIABILITY; ACCRETION DISKS; GAMMA-RAYS; EMISSION; GALAXIES; RADIATION; INJECTION AB We review and clarify the assumptions of our basic model for neutrino production in the cores of quasars, as well as those modifications to the model made subsequently by other workers. We also present a revised estimate of the neutrino background flux and spectrum obtained using more recent empirical studies of quasars and their evolution. We compare our results with other theoretical calculations and experimental upper limits on the AGN neutrino background flux. We also estimate possible neutrino fluxes from the jets of blazars detected recently by the EGRET experiment on the Compton Gamma Ray Observatory. We discuss the theoretical implications of these estimates. RP NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA. RI Stecker, Floyd/D-3169-2012 NR 66 TC 128 Z9 130 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PD JAN PY 1996 VL 75 IS 1-2 BP 341 EP 355 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UB063 UT WOS:A1996UB06300026 ER PT J AU Stecker, FW DeJager, OC AF Stecker, FW DeJager, OC TI Absorption of high energy gamma-rays by low energy intergalactic photons SO SPACE SCIENCE REVIEWS LA English DT Review ID LACERTAE OBJECT MARKARIAN-421; BACKGROUND-EXPLORER COBE; INFRARED RADIATION; EGRET TELESCOPE; EVOLUTION; EMISSION; BLAZARS; 3C-279; ORIGIN AB Following our previously proposed technique, we have used the recent gamma-ray observations of Mkr421 to place theoretically significant constraints on the magnitude of the intergalactic infrared radiation field (IIRF). Our 2 sigma upper limits are consistent with normal IR production by stars and dust in galaxies. They rule out exotic mechanisms proposed to produce a larger IIRF. Although they are still subject to revision and are unconfirmed, the data on the spectrum of Mkr421 hint at a possible absorption cutoff which could be produced by an IIRF of the magnitude expected from stellar emission and reprocessing in galaxies. Using models for the low energy intergalactic photon spectrum from microwave to ultraviolet energies, we calculate the opacity of intergalactic space to gamma-rays as a function of energy and redshift. These calculations indicate that the GeV gamma-ray burst recently observed by the CGRO EGRET detector originates at a redshift less than similar to 1.5. C1 POTCHEFSTROOM UNIV CHRISTIAN HIGHER EDUC, DEPT PHYS, POTCHEFSTROOM 2520, SOUTH AFRICA. RP NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA. RI Stecker, Floyd/D-3169-2012 NR 50 TC 12 Z9 12 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PD JAN PY 1996 VL 75 IS 1-2 BP 401 EP 412 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UB063 UT WOS:A1996UB06300030 ER PT B AU Seery, BD Cramer, DB Stevens, C Lencioni, D AF Seery, BD Cramer, DB Stevens, C Lencioni, D BE Casani, EK VanderDoes, MA TI EO-1: NASA's first New Millennium Earth orbiting mission SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE Hyperspectral Imaging; Multispectral Imaging; New Millennium; Earth orbiting; silicon carbide optics; array detectors; infrared and visible detectors; phased array antenna C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 4 EP 10 DI 10.1117/12.255149 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00001 ER PT B AU Rodgers, DH Alkalai, L Beauchamp, PM Chen, GS Crisp, MP Brown, RH Davidson, JM Huxtable, D Penzo, PA Petrick, SW Soderblom, LA Stewart, A Vane, G Yelle, RV AF Rodgers, DH Alkalai, L Beauchamp, PM Chen, GS Crisp, MP Brown, RH Davidson, JM Huxtable, D Penzo, PA Petrick, SW Soderblom, LA Stewart, A Vane, G Yelle, RV BE Casani, EK VanderDoes, MA TI The Kuiper express: A sciencecraft SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 11 EP 21 DI 10.1117/12.255126 PG 11 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00002 ER PT B AU Bhaskaran, S Riedel, JE Synnott, SP AF Bhaskaran, S Riedel, JE Synnott, SP BE Casani, EK VanderDoes, MA TI Autonomous optical navigation for interplanetary missions SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE optical navigation; autonomy; image processing C1 CALTECH,JET PROP LAB,NAVIGAT & FLIGHT MECH SECT,PASADENA,CA 91125. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 32 EP 43 DI 10.1117/12.255151 PG 12 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00004 ER PT B AU Pell, B Bernard, DE Chien, SA Gat, E Muscettola, N Nayak, PP Wagner, MD Williams, BC AF Pell, B Bernard, DE Chien, SA Gat, E Muscettola, N Nayak, PP Wagner, MD Williams, BC BE Casani, EK VanderDoes, MA TI A remote agent prototype for spacecraft autonomy SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE autonomous robots; agent architectures; action selection and planning; diagnosis; integration and coordination of multiple activities; fault protection; operations; real-time systems; modeling C1 NASA,AMES RES CTR,RECOM TECHNOL,MOFFETT FIELD,CA 94035. NR 0 TC 1 Z9 2 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 74 EP 90 DI 10.1117/12.255150 PG 17 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00008 ER PT B AU Riley, L Grimm, M Antsos, D Grigorian, E Kayalar, S Kermode, A Mittskus, A Neal, J Olson, E AF Riley, L Grimm, M Antsos, D Grigorian, E Kayalar, S Kermode, A Mittskus, A Neal, J Olson, E BE Casani, EK VanderDoes, MA TI Ka-band tiny transmitter for the new Millemium program SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE telecommunications; transponder; microwave systems; microwave monolithic integrated circuit; multi-chip module; digital C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 92 EP 100 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00009 ER PT B AU Tang, TK Gutierrez, RC Wilcox, JZ Stell, C Vorperian, V Dickerson, M Goldstein, B Savino, JL Li, WJ Calvet, R Charkaborty, I Bartman, R Kaiser, WJ AF Tang, TK Gutierrez, RC Wilcox, JZ Stell, C Vorperian, V Dickerson, M Goldstein, B Savino, JL Li, WJ Calvet, R Charkaborty, I Bartman, R Kaiser, WJ BE Casani, EK VanderDoes, MA TI Silicon bulk micromachined vibratory gyroscope for microspacecraft SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE microgyroscope; gyroscope; rotation rate sensor; vibratory gyroscope; navigation; silicon micromachining C1 CALTECH,JET PROP LAB,MICRODEVICES LAB,PASADENA,CA 91109. RI Li, Wen Jung/M-9995-2013 OI Li, Wen Jung/0000-0001-9616-6213 NR 0 TC 12 Z9 12 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 101 EP 115 DI 10.1117/12.255129 PG 15 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00010 ER PT B AU Clark, C YadidPecht, O Fossum, E Salomon, P Dennison, E AF Clark, C YadidPecht, O Fossum, E Salomon, P Dennison, E BE Casani, EK VanderDoes, MA TI Application of APS arrays to star and feature tracking systems SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE active pixel sensors; trackers; regional shutter C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 6 Z9 7 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 116 EP 120 DI 10.1117/12.255130 PG 5 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00011 ER PT B AU Salomon, P Fossum, E Clark, C Dennison, E AF Salomon, P Fossum, E Clark, C Dennison, E BE Casani, EK VanderDoes, MA TI Active pixel sensors for autonomous spacecraft applications SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS C1 CALTECH,JET PROP LAB,PASADENA,CA 91125. NR 0 TC 2 Z9 3 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 166 EP 175 DI 10.1117/12.255137 PG 10 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00016 ER PT B AU Kia, T Hanover, G AF Kia, T Hanover, G BE Casani, EK VanderDoes, MA TI On-orbit performance of TOPEX/POSIEDON star trackers SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE performance; on-orbit; CCD tracker; radiation C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 201 EP 212 DI 10.1117/12.255142 PG 12 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00019 ER PT B AU Eisenman, A Liebe, CC Jorgensen, JL AF Eisenman, A Liebe, CC Jorgensen, JL BE Casani, EK VanderDoes, MA TI Astronomical performance of the engineering model Orsted Advanced Stellar Compass SO SPACE SCIENCECRAFT CONTROL AND TRACKING IN THE NEW MILLENNIUM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Sciencecraft Control and Tracking in the New Millennium CY AUG 06-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE autonomy; Advanced Stellar Compass; CCD imaging; spacecraft star trackers; Oersted mission C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2198-7 J9 P SOC PHOTO-OPT INS PY 1996 VL 2810 BP 252 EP 264 DI 10.1117/12.255147 PG 13 WC Engineering, Aerospace; Instruments & Instrumentation; Remote Sensing; Optics SC Engineering; Instruments & Instrumentation; Remote Sensing; Optics GA BG61U UT WOS:A1996BG61U00024 ER PT S AU Brezovic, JL AF Brezovic, JL BE ElGenk, MS TI Space Station Laboratory SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,LYNDON B JOHNSON SPACE CTR,RES MANAGEMENT OFF,SCI APPLICAT INT CORP,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 9 EP 15 PG 7 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00002 ER PT S AU Eppler, D Amsbury, D Bates, J Scott, K AF Eppler, D Amsbury, D Bates, J Scott, K BE ElGenk, MS TI Space Station nadir pointing research window: Planned characteristics and management challenges SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,LYNDON B JOHNSON SPACE CTR,SAIC INT SPACE STN RES MANAGEMENT OFF,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 21 EP 28 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00004 ER PT S AU Lawson, PD AF Lawson, PD BE ElGenk, MS TI Research management office SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,LYNDON B JOHNSON SPACE CTR,RES MANAGEMENT OFF,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 29 EP 34 PG 6 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00005 ER PT S AU Hamaker, JW AF Hamaker, JW BE ElGenk, MS TI Single-stage-to-orbit versus two-stage-two-orbit: A cost perspective SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,ENGN COST OFF,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 59 EP 67 PG 9 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00010 ER PT S AU Whitten, RP Crawford, JL AF Whitten, RP Crawford, JL BE ElGenk, MS TI Roadmaps - A new tool for commercial space processing SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA HEADQUARTERS,OFF SPACE ACCESS & TECHNOL,SPACE PROC DIV,WASHINGTON,DC 20546. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 109 EP 116 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00017 ER PT S AU Ansari, RR Suh, KI Dubin, S DellaVecchia, MA AF Ansari, RR Suh, KI Dubin, S DellaVecchia, MA BE ElGenk, MS TI A compact fiber optic eye diagnostic system SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 149 EP 154 PG 6 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00024 ER PT S AU Abtahi, A Barmatz, M AF Abtahi, A Barmatz, M BE ElGenk, MS TI New polaradiometric method for non-contact temperature measurement SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 303 EP 307 PG 5 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00051 ER PT S AU Craft, HG Sheehan, W Johnson, A AF Craft, HG Sheehan, W Johnson, A BE ElGenk, MS TI NASA's southeast technology transfer alliance: A cooperative technology assistance initiative SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,TECHNOL TRANSFER OFF,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 309 EP 314 PG 6 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00052 ER PT S AU Heyward, AO AF Heyward, AO BE ElGenk, MS TI Lewis Research Center: Commercialization success stories SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,LEWIS RES CTR,OFF INTERAGCY & IND PROGRAMS,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 321 EP 326 PG 6 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00054 ER PT S AU Barquinero, K Cannon, D AF Barquinero, K Cannon, D BE ElGenk, MS TI TechTracs: NASA's Commercial Technology Management System SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,OFF SPACE ACCESS & TECHNOL,COMMERCIAL TECHNOL DIV,WASHINGTON,DC 20546. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 327 EP 331 PG 5 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00055 ER PT S AU Brannon, DP AF Brannon, DP BE ElGenk, MS TI Criteria for successful government industry academic partnerships SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,BAY ST LOUIS,MS 39529. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 375 EP 379 PG 5 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00065 ER PT S AU Plecity, MS Strickler, WM Bauer, RA AF Plecity, MS Strickler, WM Bauer, RA BE ElGenk, MS TI Commercialization of advanced communications technology satellite(ACTS)technology SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 421 EP 428 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00072 ER PT S AU Tucker, DS Workman, GL Smith, GA AF Tucker, DS Workman, GL Smith, GA BE ElGenk, MS TI Use of space to commercially produce ZBLAN optical fibers SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,EH34,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 439 EP 443 PG 5 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00075 ER PT S AU Smith, DD Frazier, DO Witherow, WK Paley, MS Abdeldayem, H AF Smith, DD Frazier, DO Witherow, WK Paley, MS Abdeldayem, H BE ElGenk, MS TI Potential photonic switching technologies derived from space processed organic thin films SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,ES 76,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 445 EP 450 PG 6 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00076 ER PT S AU Sibille, L Cronise, RJ Noever, DA Hunt, AJ AF Sibille, L Cronise, RJ Noever, DA Hunt, AJ BE ElGenk, MS TI Toward a benchmark material in aerogel development SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,HUNTSVILLE,AL 35812. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 451 EP 454 PG 4 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00077 ER PT S AU Chambers, KH Koschmeder, LA Hollansworth, JE ONeill, J Jones, RE Gibbons, RC AF Chambers, KH Koschmeder, LA Hollansworth, JE ONeill, J Jones, RE Gibbons, RC BE ElGenk, MS TI The NASA mobile satellite communications experiment opportunity SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,WASHINGTON,DC 20546. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 485 EP 493 PG 9 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00084 ER PT S AU Swanson, TD Buchko, MT Bello, M Brennan, P Stoyanof, MM AF Swanson, TD Buchko, MT Bello, M Brennan, P Stoyanof, MM BE ElGenk, MS TI Summary of test results for the cryogenic two-phase flight experiment SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 765 EP 771 PG 7 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00127 ER PT S AU Sugimura, R Russo, SC Gilman, DC AF Sugimura, R Russo, SC Gilman, DC BE ElGenk, MS TI Lessons learned from the flight of the NASA in-step Cryo System Experiment SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 CALTECH,JET PROPULS LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 773 EP 779 PG 7 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00128 ER PT S AU Thomson, S Chen, P Triolo, J Carosso, N AF Thomson, S Chen, P Triolo, J Carosso, N BE ElGenk, MS TI The use of molecular adsorbers for spacecraft contamination control SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 815 EP 823 PG 9 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00132 ER PT S AU Straka, S Chen, P Thomson, S Bettini, R Triolo, J Carosso, N AF Straka, S Chen, P Thomson, S Bettini, R Triolo, J Carosso, N BE ElGenk, MS TI TRMM project contamination control using molecular adsorbers SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 825 EP 831 PG 7 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00133 ER PT S AU Jackson, ME Shtessel, YB AF Jackson, ME Shtessel, YB BE ElGenk, MS TI Decoupled thermal control for Space Station Furnace Facility using sliding mode techniques SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 903 EP 910 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00147 ER PT S AU Williams, CH Borowski, SK AF Williams, CH Borowski, SK BE ElGenk, MS TI Commercially-driven human interplanetary propulsion systems: Rationale, concept, technology, and performance requirements SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 1057 EP 1064 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00169 ER PT S AU Mondt, JF Zubrin, RM AF Mondt, JF Zubrin, RM BE ElGenk, MS TI Nuclear bimodal new vision solar system missions SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 1071 EP 1076 PG 6 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00171 ER PT S AU Borowski, SK AF Borowski, SK BE ElGenk, MS TI Options for human ''return to the moon'' using tomorrow's SSTO, ISRU and LOX-augmented NTR technologies SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 1083 EP 1093 PG 11 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00173 ER PT S AU Caillat, T Allevato, CE Fleurial, JP Borshchevsky, A AF Caillat, T Allevato, CE Fleurial, JP Borshchevsky, A BE ElGenk, MS TI Preparation and some properties of N-type IrxCo1-xSb3 solid solutions SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 1315 EP 1320 PG 6 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00205 ER PT S AU Kim, YJ Edelstein, W Caro, E AF Kim, YJ Edelstein, W Caro, E BE ElGenk, MS TI Design of dual frequency interferometric SAR SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 1535 EP 1540 PG 6 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00237 ER PT S AU Wheeler, K Renick, P AF Wheeler, K Renick, P BE ElGenk, MS TI Cassini radar hardware technologies SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 1541 EP 1545 PG 5 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00238 ER PT S AU Brody, S Kaplan, D McKay, C Rapp, D AF Brody, S Kaplan, D McKay, C Rapp, D BE ElGenk, MS TI Exploring Mars using local resources SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 NASA HEADQUARTERS,WASHINGTON,DC 20546. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 1551 EP 1552 PG 2 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00241 ER PT S AU Casani, EK Wilson, B Ridenoure, R AF Casani, EK Wilson, B Ridenoure, R BE ElGenk, MS TI The New Millennium Program: Positioning NASA for ambitious space and Earth science missions for the 21st century SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 1553 EP 1557 PG 5 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00242 ER PT S AU Randolph, JE Miyake, RN Nesmith, BJ Howard, RJ Dirling, RB AF Randolph, JE Miyake, RN Nesmith, BJ Howard, RJ Dirling, RB BE ElGenk, MS TI Solar probe technology challenges SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-96), PTS 1-3: 1ST CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; 1ST CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 2ND SPACECRAFT THERMAL CONTROL SYMPOSIUM; 13TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION - FUTURE SPACE AND EARTH SCIENCE MISSIONS - SPECIAL TOPIC; REMOTE SENSING FOR COMMERCIAL, CIVIL AND SCIENCE APPLICATIONS - SPECIAL TOPIC SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF -96) CY JAN 07-11, 1996 CL ALBUQUERQUE, NM SP Univ New Mexico, Inst Space & Cucl Power Studies, Def Nucl Agcy, NASA, US DOE, USAF, Amer Inst Aeronaut & Astronaut, Natl Sect, Amer Inst Aeronaut & Astronaut, Local Sect, Amer Inst Chem Engineers, Heat Transfer & Energy Convers Div, Amer Nucl Soc, Trinity Sect, Amer Soc Mech Engineers, Nucl Engn Div, Amer Soc Mech Engineers, Heat Transfer Div, ASTM, Comm E 10 Nucl Technol & Appl, Int Astronaut Federat, IEEE, Microwave Theory & Tech Soc, IEEE, Nucl & Plasma Sci Soc, New Mexico Acad Sci, New Mexico Space Grant Consortium, Profess Aerosp Contractors Assoc C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-562-3 J9 AIP CONF PROC PY 1996 IS 361 BP 1559 EP 1566 PG 8 WC Engineering, Aerospace; Physics, Applied SC Engineering; Physics GA BE99C UT WOS:A1996BE99C00243 ER PT B AU Wade, LA Lilienthal, GW Terebey, S Kadogawa, H Hawarden, TG Rourke, K VanBuren, D AF Wade, LA Lilienthal, GW Terebey, S Kadogawa, H Hawarden, TG Rourke, K VanBuren, D BE Bely, PY Breckinridge, JB TI Mid-infraRed optimized resolution spacecraft (MIRORS) SO SPACE TELESCOPES AND INSTRUMENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instruments IV CY AUG 06-07, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE infrared telescope; partially filled aperture; image reconstruction; infrared astronomy; passively cooled telescope C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2195-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2807 BP 20 EP 31 DI 10.1117/12.255108 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BG61H UT WOS:A1996BG61H00003 ER PT B AU Colavita, MM McGuire, JP Bartman, RK Blackwood, GH Laskin, RA Lau, KH Shao, M Yu, JW AF Colavita, MM McGuire, JP Bartman, RK Blackwood, GH Laskin, RA Lau, KH Shao, M Yu, JW BE Bely, PY Breckinridge, JB TI Separated spacecraft interferometer concept for the New Millennium Program SO SPACE TELESCOPES AND INSTRUMENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instruments IV CY AUG 06-07, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE optical interferometry; space telescopes; spacecraft constellations; separated-spacecraft interferometry; New Millennium Program; formation flying; kilometric optical gyro C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 3 Z9 3 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2195-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2807 BP 51 EP 58 DI 10.1117/12.255122 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BG61H UT WOS:A1996BG61H00005 ER PT B AU Martin, N Amato, M Buchko, M Farley, R Frigaard, M Generie, J McGinnis, M Kristensen, R Polny, J Dame, R AF Martin, N Amato, M Buchko, M Farley, R Frigaard, M Generie, J McGinnis, M Kristensen, R Polny, J Dame, R BE Bely, PY Breckinridge, JB TI The TopHat series of top mounted balloon-borne telescopes SO SPACE TELESCOPES AND INSTRUMENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instruments IV CY AUG 06-07, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE CMBR anisotropy; infra-red telescopes; telescopes; balloon experiments C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2195-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2807 BP 86 EP 97 DI 10.1117/12.255125 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BG61H UT WOS:A1996BG61H00008 ER PT B AU Mather, JC Seery, BD Bely, PY AF Mather, JC Seery, BD Bely, PY BE Bely, PY Breckinridge, JB TI The Next Generation Space Telescope (NGST) SO SPACE TELESCOPES AND INSTRUMENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instruments IV CY AUG 06-07, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE space telescopes; space astronomical instruments C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 5 Z9 5 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2195-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2807 BP 98 EP 105 DI 10.1117/12.255119 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BG61H UT WOS:A1996BG61H00009 ER PT B AU Gursel, Y AF Gursel, Y BE Bely, PY Breckinridge, JB TI Metrology for spatial interferometry .3. SO SPACE TELESCOPES AND INSTRUMENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instruments IV CY AUG 06-07, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 9 Z9 9 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2195-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2807 BP 148 EP 161 DI 10.1117/12.255096 PG 14 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BG61H UT WOS:A1996BG61H00014 ER PT B AU Morgan, R Shaklan, S Yu, J AF Morgan, R Shaklan, S Yu, J BE Bely, PY Breckinridge, JB TI Two-laser heterodyne metrology for a separated spacecraft interferometer SO SPACE TELESCOPES AND INSTRUMENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instruments IV CY AUG 06-07, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE heterodyne interferometry; metrology; spaceborne interferometer C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2195-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2807 BP 162 EP 169 DI 10.1117/12.255097 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BG61H UT WOS:A1996BG61H00015 ER PT B AU Content, DA Boucarut, RA Bowers, CW Madison, TJ Wright, GA Lindler, DJ Huang, LK Puc, BP Standley, C Norton, TA AF Content, DA Boucarut, RA Bowers, CW Madison, TJ Wright, GA Lindler, DJ Huang, LK Puc, BP Standley, C Norton, TA BE Bely, PY Breckinridge, JB TI Development and testing of diffraction gratings for the space telescope imaging spectrograph SO SPACE TELESCOPES AND INSTRUMENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Telescopes and Instruments IV CY AUG 06-07, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, NARSIA, ASPRS DE diffraction gratings; Hubble space telescope; space telescope imaging spectrograph; echelle C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 9 Z9 9 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2195-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2807 BP 267 EP 278 DI 10.1117/12.255105 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BG61H UT WOS:A1996BG61H00024 ER PT S AU Folta, DC Knapp, CT AF Folta, DC Knapp, CT BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI Trajectory state estimation for a translunar and weakly bound spacecraft in the Earth-Moon-Sun system SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 NASA,GODDARD SPACE FLIGHT CTR,FLIGHT DYNAM DIV,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 33 EP 52 PG 20 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00003 ER PT S AU Folta, DC Sharer, PJ AF Folta, DC Sharer, PJ BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI Multiple lunar flyby targeting for the wind mission SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 NASA,GODDARD SPACE FLIGHT CTR,FLIGHT DYNAM DIV,GREENBELT,MD 20771. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 53 EP 67 PG 15 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00004 ER PT S AU Wagner, LA Wilks, NA AF Wagner, LA Wilks, NA BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI CLL lunar trajectory design SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 NASA,JOHNSON SPACE CTR,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 69 EP 82 PG 14 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00005 ER PT S AU Dagen, JD AF Dagen, JD BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI Structural integration of the Space Shuttle and the Mir Space Station SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 NASA,JOHNSON SPACE CTR,HOUSTON,TX 77058. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 461 EP 471 PG 11 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00029 ER PT S AU Jacobson, RA AF Jacobson, RA BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI The orbital motion of the Martian satellites: An application of artificial satellite theory SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 633 EP 652 PG 20 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00039 ER PT S AU Williams, CH AF Williams, CH BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI An analytic approximation to very high specific impulse & specific power interplanetary space mission analysis SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 801 EP 818 PG 18 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00049 ER PT S AU Burkhart, PD Bishop, RH AF Burkhart, PD Bishop, RH BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI Adaptive orbit determination for interplanetary spacecraft SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 CALTECH,JET PROP LAB,NAV & FLIGHT MECH SECT,TECH STAFF,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 819 EP 837 PG 19 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00050 ER PT S AU Lee, W Sidney, W AF Lee, W Sidney, W BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI Mission plan for Mars global surveyor SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 CALTECH,JET PROP LAB,SYST DIV,TECH STAFF,PASADENA,CA 91109. NR 0 TC 4 Z9 4 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 839 EP 858 PG 20 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00051 ER PT S AU Wagner, LA Munk, MM AF Wagner, LA Munk, MM BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI MISR interplanetary trajectory design SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. NR 0 TC 4 Z9 4 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 859 EP 876 PG 18 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00052 ER PT S AU Ih, CHC Hilbert, KB McMahon, EH Bahrami, KA AF Ih, CHC Hilbert, KB McMahon, EH Bahrami, KA BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI On improving the Galileo scan platform cone controller performance in cruise mode remote sensing SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 1 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 1073 EP 1092 PG 20 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00065 ER PT S AU Carpenter, JR Bishop, RH AF Carpenter, JR Bishop, RH BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI Flight data results of estimate fusion for spacecraft rendezvous navigation from shuttle mission STS-69 SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 NASA,LYNDON B JOHNSON SPACE CTR,AEROSCI & FLIGHT MECH DIV,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 1257 EP 1276 PG 20 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00077 ER PT S AU Guinn, JR Munson, TN Vincent, MA AF Guinn, JR Munson, TN Vincent, MA BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI Spacecraft autonomous navigation for Earth ground track repeat orbits using GPS SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 CALTECH,JET PROP LAB,NAVIGAT & FLIGHT MECH SECT,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 1313 EP 1329 PG 17 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00080 ER PT S AU WoodsVedeler, JA Horta, LG AF WoodsVedeler, JA Horta, LG BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI On-orbit application of H-infinity to the Middeck Active Controls Experiment: Overview of results SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 NASA,LANGLEY RES CTR,STRUCT DYNAM BRANCH,HAMPTON,VA 23681. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 1403 EP 1419 PG 17 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00085 ER PT S AU Evans, SW AF Evans, SW BE Powell, GE Bishop, RH Lundberg, JB Smith, RH TI Post deployment recontact issues for the SEDS/SEDSAT mission SO SPACEFLIGHT MECHANICS 1996, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Conference CY FEB 12-15, 1996 CL AUSTIN, TX SP AAS, AIAA C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-414-1 J9 ADV ASTRONAUT SCI PY 1996 VL 93 BP 1589 EP 1604 PG 16 WC Engineering, Aerospace SC Engineering GA BG27W UT WOS:A1996BG27W00099 ER PT B AU Paquin, RA Coulter, DR Norris, DD Augason, GC Stier, MT Cayrel, M Parsonage, T AF Paquin, RA Coulter, DR Norris, DD Augason, GC Stier, MT Cayrel, M Parsonage, T BE Gee, AE Houee, JF TI New fabrication processes for dimensionally stable beryllium mirrors SO SPECIFICATION, PRODUCTION, AND TESTING OF OPTICAL COMPONENTS AND SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Specification, Production, and Testing of Optical Components and Systems CY MAY 13-16, 1996 CL GLASGOW, SCOTLAND SP Corning France, Essilor Int, Glasgow Dev Agcy, Pilkington Optron, Scottish Enterprise, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev, Inst Phys C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2160-X J9 P SOC PHOTO-OPT INS PY 1996 VL 2775 BP 480 EP 490 DI 10.1117/12.246778 PG 11 WC Optics SC Optics GA BG32V UT WOS:A1996BG32V00047 ER PT B AU Jacoby, RH Adelstein, BD Ellis, SR AF Jacoby, RH Adelstein, BD Ellis, SR BE Bolas, MT Fisher, SS Merritt, JO TI Improved temporal response in virtual environments through system hardware and software reorganization SO STEREOSCOPIC DISPLAYS AND VIRTUAL REALITY SYSTEMS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Stereoscopic Displays and Applications VII/Complementary Conference - The Engineering Reality of Virtual Reality 1996 CY JAN 30-FEB 02, 1996 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers DE virtual environments; virtual reality; latency; delay; update rate; real time; trackers C1 UNIV CALIF BERKELEY,NASA,AMES RES CTR,STERLING SOFTWARE,BERKELEY,CA. NR 0 TC 8 Z9 8 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2027-1 J9 P SOC PHOTO-OPT INS PY 1996 VL 2653 BP 271 EP 284 DI 10.1117/12.237447 PG 14 WC Computer Science, Cybernetics; Optics SC Computer Science; Optics GA BF46U UT WOS:A1996BF46U00032 ER PT B AU Jones, SP Jansen, R Fusaro, R AF Jones, SP Jansen, R Fusaro, R GP SOC TRIBOLOGISTS & LUBRICAT ENGINEERS TI Neural networks to predict tribological properties SO STLE 1996 ANNUAL MEETING, TECHNICAL PREPRINTS LA English DT Proceedings Paper CT Society-of-Tribologists-and-Lubrication-Engineers 51st Annual Meeting CY MAY 19-23, 1996 CL CINCINNATI, OH SP Soc Tribologists & Lubricat Engineers DE computers in tribology; neural networks; accelerated testing; wear; wear mechanisms; life testing methods; tribology C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068-2376 PY 1996 BP 81 EP 91 PG 11 WC Engineering, Mechanical SC Engineering GA BF60F UT WOS:A1996BF60F00010 ER PT S AU Huntress, WT AF Huntress, WT BE Bainum, PM May, GL Ohkami, Y Uesugi, K Faren, Q Furong, L TI NASA's space science program: Our outlook for the new millennium SO STRENGTHENING COOPERATION IN THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 6th International Space Conference of Pacific Basin Societies on Strengthening Cooperation in the 21st-Century CY DEC 06-08, 1995 CL MARINA DEL REY, CA SP Amer Astronaut Soc, Japanese Rocket Soc, Chinese Soc Astronaut C1 NASA HEADQUATERS,WASHINGTON,DC 20546. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-409-5 J9 ADV ASTRONAUT SCI PY 1996 VL 91 BP 3 EP 30 PG 28 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BF73F UT WOS:A1996BF73F00001 ER PT S AU EricssonJackson, AJ AF EricssonJackson, AJ BE Bainum, PM May, GL Ohkami, Y Uesugi, K Faren, Q Furong, L TI Model development for digitally controlled large orbiting platforms with go-located actuators and sensors SO STRENGTHENING COOPERATION IN THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 6th International Space Conference of Pacific Basin Societies on Strengthening Cooperation in the 21st-Century CY DEC 06-08, 1995 CL MARINA DEL REY, CA SP Amer Astronaut Soc, Japanese Rocket Soc, Chinese Soc Astronaut C1 HOWARD UNIV,NASA,CTR STUDY EXTRATERR & TERR ATMOSPHERES,WASHINGTON,DC. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-409-5 J9 ADV ASTRONAUT SCI PY 1996 VL 91 BP 107 EP 126 PG 20 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BF73F UT WOS:A1996BF73F00009 ER PT S AU Agan, MJ AF Agan, MJ BE Bainum, PM May, GL Ohkami, Y Uesugi, K Faren, Q Furong, L TI A broadband aeronautical communications experiment SO STRENGTHENING COOPERATION IN THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 6th International Space Conference of Pacific Basin Societies on Strengthening Cooperation in the 21st-Century CY DEC 06-08, 1995 CL MARINA DEL REY, CA SP Amer Astronaut Soc, Japanese Rocket Soc, Chinese Soc Astronaut C1 CALTECH,JET PROP LAB,SATELLITE COMMUN GRP,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-409-5 J9 ADV ASTRONAUT SCI PY 1996 VL 91 BP 181 EP 190 PG 10 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BF73F UT WOS:A1996BF73F00015 ER PT S AU Su, CH Gillies, DC Szofran, FR Watring, DA Lehoczky, SL AF Su, CH Gillies, DC Szofran, FR Watring, DA Lehoczky, SL BE Bainum, PM May, GL Ohkami, Y Uesugi, K Faren, Q Furong, L TI The influence of reduced gravity on the crystal growth of electronic materials SO STRENGTHENING COOPERATION IN THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 6th International Space Conference of Pacific Basin Societies on Strengthening Cooperation in the 21st-Century CY DEC 06-08, 1995 CL MARINA DEL REY, CA SP Amer Astronaut Soc, Japanese Rocket Soc, Chinese Soc Astronaut C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-409-5 J9 ADV ASTRONAUT SCI PY 1996 VL 91 BP 351 EP 363 PG 13 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BF73F UT WOS:A1996BF73F00033 ER PT S AU Jacobs, DV AF Jacobs, DV BE Bainum, PM May, GL Ohkami, Y Uesugi, K Faren, Q Furong, L TI The international space station: Background and current status SO STRENGTHENING COOPERATION IN THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 6th International Space Conference of Pacific Basin Societies on Strengthening Cooperation in the 21st-Century CY DEC 06-08, 1995 CL MARINA DEL REY, CA SP Amer Astronaut Soc, Japanese Rocket Soc, Chinese Soc Astronaut C1 NASA,LYNDON B JOHNSON SPACE CTR,INT SPACE STN PROGRAM OFF,RUSSIAN INTEGRAT OFF,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-409-5 J9 ADV ASTRONAUT SCI PY 1996 VL 91 BP 613 EP 629 PG 17 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BF73F UT WOS:A1996BF73F00055 ER PT S AU Spencer, R AF Spencer, R BE Bainum, PM May, GL Ohkami, Y Uesugi, K Faren, Q Furong, L TI International Space Station assembly sequence SO STRENGTHENING COOPERATION IN THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 6th International Space Conference of Pacific Basin Societies on Strengthening Cooperation in the 21st-Century CY DEC 06-08, 1995 CL MARINA DEL REY, CA SP Amer Astronaut Soc, Japanese Rocket Soc, Chinese Soc Astronaut C1 NASA,LYNDON B JOHNSON SPACE CTR,SPACE STN PROGRAM OFF,HOUSTON,TX 77058. NASA,LYNDON B JOHNSON SPACE CTR,SPACE STN PROGRAM OFF,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-409-5 J9 ADV ASTRONAUT SCI PY 1996 VL 91 BP 631 EP 648 PG 18 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BF73F UT WOS:A1996BF73F00056 ER PT S AU Nakagawa, RY Berry, SR AF Nakagawa, RY Berry, SR BE Bainum, PM May, GL Ohkami, Y Uesugi, K Faren, Q Furong, L TI Multinational team dynamics within the International Space Station Program Office SO STRENGTHENING COOPERATION IN THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 6th International Space Conference of Pacific Basin Societies on Strengthening Cooperation in the 21st-Century CY DEC 06-08, 1995 CL MARINA DEL REY, CA SP Amer Astronaut Soc, Japanese Rocket Soc, Chinese Soc Astronaut C1 NASA,LYNDON B JOHNSON SPACE CTR,INT SPACE STN PROGRAM OFF,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-409-5 J9 ADV ASTRONAUT SCI PY 1996 VL 91 BP 675 EP 691 PG 17 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BF73F UT WOS:A1996BF73F00059 ER PT S AU OHandley, DA Arno, R AF OHandley, DA Arno, R BE Bainum, PM May, GL Ohkami, Y Uesugi, K Faren, Q Furong, L TI Moon and Mars robotic missions - Path to human presence? SO STRENGTHENING COOPERATION IN THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 6th International Space Conference of Pacific Basin Societies on Strengthening Cooperation in the 21st-Century CY DEC 06-08, 1995 CL MARINA DEL REY, CA SP Amer Astronaut Soc, Japanese Rocket Soc, Chinese Soc Astronaut C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-409-5 J9 ADV ASTRONAUT SCI PY 1996 VL 91 BP 693 EP 698 PG 6 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BF73F UT WOS:A1996BF73F00060 ER PT S AU Shapiro, BE AF Shapiro, BE BE Bainum, PM May, GL Ohkami, Y Uesugi, K Faren, Q Furong, L TI Phase plane analysis and observed frozen orbit for the TOPEX/Poseidon mission SO STRENGTHENING COOPERATION IN THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 6th International Space Conference of Pacific Basin Societies on Strengthening Cooperation in the 21st-Century CY DEC 06-08, 1995 CL MARINA DEL REY, CA SP Amer Astronaut Soc, Japanese Rocket Soc, Chinese Soc Astronaut C1 CALTECH,JET PROP LAB,TECH STAFF,PASADENA,CA 91109. NR 0 TC 2 Z9 2 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-409-5 J9 ADV ASTRONAUT SCI PY 1996 VL 91 BP 853 EP 872 PG 20 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BF73F UT WOS:A1996BF73F00074 ER PT B AU Noebe, RD Walston, WS AF Noebe, RD Walston, WS BE Nathal, MV Darolia, R Liu, CT Martin, PL Miracle, DB Wagner, R Yamaguchi, M TI Prospects for the development of structural NiAl alloys SO STRUCTURAL INTERMETALLICS 1997 LA English DT Proceedings Paper CT 2nd International Symposium on Structural Intermetallics (ISSI) CY SEP 21-25, 1997 CL SEVEN SPRING MT RESORT, CHAMPION, PA SP Minerals Met & Mat Soc, Struct Mat Div, High Temp Alloys & Titanium Comm, NASA Lewis Res Ctr, Oak Ridge Natl Lab, USAF Off Sci Res, Commonwealth Sci & Ind Res Org, Austr, Rockwell Sci Ctr, ABB Power Generat, Allison Engine Co, Allison Adv Dev, GE, Allied Signal, Plansee Aktiengesell, R & D Inst Met & Composites Future Ind, Tokyo, Japan HO SEVEN SPRING MT RESORT AB NiAl alloys continue to loom on the technological horizon as a potential high temperature replacement for Ni-base superalloys. To be competitive with superalloys, a balance of properties including reasonable fracture resistance, excellent creep strength, high thermal conductivity, and environmental durability is required. While conventional polycrystalline alloys do not meet these requirements and fiber reinforced composites have not lived up to their initial expectations for lack of a compatible fiber, there are still several classes of NiAl-based materials that have received significant attention. These are precipitation strengthened NiAl single crystals, directionally solidified NiAl-based eutectics, and dispersion strengthened NiAl alloys. The latest advancements, remaining problems, and lessons learned during the development of these systems will be discussed along with an assessment for the potential commercialization of NiAl and the most likely market niches. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Noebe, RD (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-375-9 PY 1996 BP 573 EP 584 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Composites SC Materials Science; Metallurgy & Metallurgical Engineering GA BK32R UT WOS:000071821900062 ER PT B AU Whittenberger, JD Garg, A Noebe, RD Walston, WS DArolia, R AF Whittenberger, JD Garg, A Noebe, RD Walston, WS DArolia, R BE Nathal, MV Darolia, R Liu, CT Martin, PL Miracle, DB Wagner, R Yamaguchi, M TI Effect of chemistry, microstructure and orientation on 1100-1400 K plastic flow properties of Hf-doped NiAl single crystals SO STRUCTURAL INTERMETALLICS 1997 LA English DT Proceedings Paper CT 2nd International Symposium on Structural Intermetallics (ISSI) CY SEP 21-25, 1997 CL SEVEN SPRING MT RESORT, CHAMPION, PA SP Minerals Met & Mat Soc, Struct Mat Div, High Temp Alloys & Titanium Comm, NASA Lewis Res Ctr, Oak Ridge Natl Lab, USAF Off Sci Res, Commonwealth Sci & Ind Res Org, Austr, Rockwell Sci Ctr, ABB Power Generat, Allison Engine Co, Allison Adv Dev, GE, Allied Signal, Plansee Aktiengesell, R & D Inst Met & Composites Future Ind, Tokyo, Japan HO SEVEN SPRING MT RESORT AB A study of the 1100-1400 K elevated temperature deformation properties of three NiAl-0.5Hf single crystal alloys containing differing amounts of Si and Ti has been conducted This work indicates that higher Si contents in combination with a snail amount of Ti leads to the precipitation of a high density of fine and coherent G-phase precipitates which maximize strength properties to at least 1300 K. Although prior thermal exposure can dissolve the G-phase precipitates in low Si-content alloys, such heat treatments only somewhat weaken the high temperature strength under faster deformation conditions. The < 001 > orientation appears to maintain a slight strength advantage over the < 110 > orientation under slower strain rate conditions. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Whittenberger, JD (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-375-9 PY 1996 BP 631 EP 640 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Composites SC Materials Science; Metallurgy & Metallurgical Engineering GA BK32R UT WOS:000071821900068 ER PT B AU Gabb, TP Gayda, J Chatterjee, A Ress, R AF Gabb, TP Gayda, J Chatterjee, A Ress, R BE Nathal, MV Darolia, R Liu, CT Martin, PL Miracle, DB Wagner, R Yamaguchi, M TI Mission cycle behavior of orthorhombic titanium matrix composite SO STRUCTURAL INTERMETALLICS 1997 LA English DT Proceedings Paper CT 2nd International Symposium on Structural Intermetallics (ISSI) CY SEP 21-25, 1997 CL SEVEN SPRING MT RESORT, CHAMPION, PA SP Minerals Met & Mat Soc, Struct Mat Div, High Temp Alloys & Titanium Comm, NASA Lewis Res Ctr, Oak Ridge Natl Lab, USAF Off Sci Res, Commonwealth Sci & Ind Res Org, Austr, Rockwell Sci Ctr, ABB Power Generat, Allison Engine Co, Allison Adv Dev, GE, Allied Signal, Plansee Aktiengesell, R & D Inst Met & Composites Future Ind, Tokyo, Japan HO SEVEN SPRING MT RESORT AB The objective of this study was to evaluate the fatigue behavior of a unidirectional orthorhombic titanium aluminide matrix composite in realistic compressor conditions. Isothermal fatigue, thermomechanical fatigue, and mission profile fatigue tests were performed at compressor application temperatures and applied stresses. The effects of varying temperature and applied stress on fatigue cyclic response, life, and failure mechanisms were evaluated. The effects of different components of mission cycles were then systematically investigated. It was found that the mission cycles were more damaging than isothermal and classic thermomechanical fatigue tests for a given maximum temperature and maximum applied stress. The thermal and mechanical excursions associated with engine startup and shutdown in the mission cycles combined with the dwell at maximum temperature and stress were found to reduce life. This deficit appeared to be associated with stress relaxation of the matrix and subsequent load shedding to the fibers. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Gabb, TP (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-375-9 PY 1996 BP 913 EP 922 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Composites SC Materials Science; Metallurgy & Metallurgical Engineering GA BK32R UT WOS:000071821900100 ER PT B AU Hebsur, MG Nathal, MV AF Hebsur, MG Nathal, MV BE Nathal, MV Darolia, R Liu, CT Martin, PL Miracle, DB Wagner, R Yamaguchi, M TI Strong, tough, and pest resistant MoSi2-base hybrid composite for structural applications SO STRUCTURAL INTERMETALLICS 1997 LA English DT Proceedings Paper CT 2nd International Symposium on Structural Intermetallics (ISSI) CY SEP 21-25, 1997 CL SEVEN SPRING MT RESORT, CHAMPION, PA SP Minerals Met & Mat Soc, Struct Mat Div, High Temp Alloys & Titanium Comm, NASA Lewis Res Ctr, Oak Ridge Natl Lab, USAF Off Sci Res, Commonwealth Sci & Ind Res Org, Austr, Rockwell Sci Ctr, ABB Power Generat, Allison Engine Co, Allison Adv Dev, GE, Allied Signal, Plansee Aktiengesell, R & D Inst Met & Composites Future Ind, Tokyo, Japan HO SEVEN SPRING MT RESORT AB Addition of about 30 to 50 vol % of Si3N4 particulate to MoSi2 improved resistance to low temperature accelerated oxidation by forming a Si2ON2 protective scale and thereby eliminating catastrophic 'pest failure'. The Si3N4 addition also improved the high temperature creep strength by nearly five orders of magnitude, doubled the room temperature toughness and significantly lowered the CTE of the MoSi2 and eliminated matrix cracking in SCS-6 reinforced composites even after thermal cycling. The SCS-6 fiber reinforcement improved the room temperature fracture toughness by seven times and impact resistance by five times. The composite exhibited excellent strength and toughness improvement up to 1400 degrees C. More recently, tape casting was adopted as the preferred processing of MoSi2-base composites for improved fiber spacing, ability to use small diameter fibers, and for lower cost. Good strength and toughness values were also obtained with fine diameter Hi-Nicalon tow fibers. This hybrid composite remains competitive with ceramic matrix composites as a replacement for Ni-base superalloys in aircraft engine applications. C1 NASA, LERC Grp, NYMA Inc, Brookpark, OH 44142 USA. RP Hebsur, MG (reprint author), NASA, LERC Grp, NYMA Inc, Brookpark, OH 44142 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-375-9 PY 1996 BP 949 EP 958 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Composites SC Materials Science; Metallurgy & Metallurgical Engineering GA BK32R UT WOS:000071821900104 ER PT B AU Chavez, DJ AF Chavez, DJ BE Jones, N Brebbia, CA Watson, AJ TI Response of RCS cone subjected to an MMH nitrate detonation SO STRUCTURES UNDER SHOCK AND IMPACT IV LA English DT Proceedings Paper CT 4th International Conference on Structures Under Shock and Impact (SUSI 96) CY JUL, 1996 CL UDINE, ITALY SP Wessex Inst Technol, UK C1 NASA,JOHNSON SPACE CTR WHITE SANDS TEST FACIL,ALLIEDSIGNAL TECH SERV CORP TEAM,LAS CRUCES,NM. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPUTATIONAL MECHANICS PUBLICATIONS LTD PI SOUTHAMPTON PA ASHURST LODGE, SOUTHAMPTON, HANTS, ENGLAND S04 2AA BN 1-85312-400-1 PY 1996 BP 211 EP 220 PG 10 WC Acoustics; Construction & Building Technology; Engineering, Civil; Mechanics SC Acoustics; Construction & Building Technology; Engineering; Mechanics GA BG15Q UT WOS:A1996BG15Q00019 ER PT B AU Dreshfield, RL AF Dreshfield, RL BE Kissinger, RD Deye, DJ Anton, DL Cetel, AD Nathal, MV Pollock, TM Woodford, DA TI Long time creep rupture of Haynes (TM) Alloy 188 SO SUPERALLOYS 1996 LA English DT Proceedings Paper CT 8th International Symposium on Superalloys CY SEP 22-26, 1996 CL CHAMPION, PA SP 7 Springs Int Symp Comm, Minerals Met & Mat Soc, Minerals Met & Mat Soc, High Temperature Alloys Comm, ASM Int ID VACUUM; 1093-K; AIR AB The creep of Haynes Alloy 188 sheet in air was studied at temperatures of 790 degrees, 845 degrees and 900 degrees C for times in excess of 30,000 h as part of a program to assure that Haynes Alloy 188 could be used in critical components of a solar dynamic power conversion system for Space Station Freedom. The rupture life and time to 0.5 and 1.0 percent creep strain of creep rupture specimens which had lives from about 6,000 to nearly 59,000 h are reported. Both welded and as-received specimens were tested. The welded specimen had essentially the same lives as the as-received specimens. Comparison of this data with previously published results suggests that this material was similar in behavior to that previously studied by Haynes except at 790 degrees C where the current sheet is somewhat stronger in stress rupture. Therefore the previously published data for Haynes Alloy 188 may be used in conjunction with this data to estimate the lives of components for a long life solar dynamic power system. Three creep rupture tests were discontinued after 16,500 to 23,200 h and tensile tested at room temperature or 480 degrees C. The elongation of all three specimens was substantially reduced compared to the as-received condition or as aged (without applied stress) for 22,500 h at 820 degrees C. The reduction in elongation is thought to be caused by the presence oxidized pores found across the thickness of the interrupted creep specimens. The implications of the severe loss of ductility observed in tensile rests after prolonged creep test needs further study. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Dreshfield, RL (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 8 TC 0 Z9 0 U1 0 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-352-X PY 1996 BP 383 EP 389 PG 7 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BM48H UT WOS:000078874000044 ER PT B AU Kalluri, S Rao, KBS Halford, GR McGaw, MA AF Kalluri, S Rao, KBS Halford, GR McGaw, MA BE Loria, EA TI Deformation mechanisms and fatigue behavior of prestrained Inconel 718 superalloy SO SUPERALLOYS 718, 625, 706 AND VARIOUS DERIVATIVES LA English DT Proceedings Paper CT International Symposium on Superalloys 718, 625, 706 and Various Derivatives CY JUN 15-18, 1997 CL PITTSBURGH, PA SP Minerals Met & Mat Soc, ASM Int, Natl Assoc Corros Engineers, Nickel Dev Inst AB The deformation mechanisms and fatigue behavior of prestrained Inconel 718 superalloy under fully-reversed fatigue were investigated at room temperature. Uniform gage section specimens were monotonically strained initially in either tension or compression up to 2% strain. Fully-reversed fatigue tests were subsequently conducted both on as-machined (no prestrain) and monotonically prestrained specimens in total strain control at a strain range of 0.8%. All tests were conducted in a computer-controlled servohydraulic test system at room temperature. Evolution of stress ranges and mean stresses observed during the fatigue tests on as-machined and prestrained specimens are reported. The specimens were sectioned and examined in a transmission electron microscope to reveal the deformation mechanisms under different types of loading. Results of the investigation and comparisons of the mechanisms of deformation observed under monotonic tensile strain, monotonic compressive strain, fully-reversed fatigue, tensile strain followed by fully-reversed fatigue, and compressive strain followed by fully-reversed fatigue are reported. Fatigue lives of the prestrained specimens are compared with life predictions by two different methods. C1 NASA, Lewis Res Ctr, NYMA Inc, Cleveland, OH 44135 USA. RP Kalluri, S (reprint author), NASA, Lewis Res Ctr, NYMA Inc, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-376-7 PY 1996 BP 595 EP 606 PG 12 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BK32V UT WOS:000071823100062 ER PT B AU Wooden, DH AF Wooden, DH BE McCray, R Wang, Z TI Spectrophotometry of SN 1987A from the Kuiper airborne observatory SO SUPERNOVAE AND SUPERNOVA REMNANTS SE IAU COLLOQUIUM LA English DT Proceedings Paper CT International-Astronomical-Union Colloquium 145 on Supernovae and Supernova Remnants CY MAY 24-29, 1993 CL XIAN, PEOPLES R CHINA SP Int Astron Union, State Sci & Technol Commiss China, Basic Res Div, Chinese Acad Sci, Dept Math & Phys, Natl Nat Sci Fdn China, State Educ Commiss China, Chinese Astron Soc, Nanjing Univ, European So Observatory, Max Planck Fdn Germany, US NASA, Amer Astron Soc, US Natl Sci Fdn, Int Sci Fdn C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI CAMBRIDGE PA THE PITT BUILDING, TRUMPINGTON ST, CAMBRIDGE, CAMBS, ENGLAND CB2 1RP BN 0-521-46080-8 J9 IAU COLLOQ PY 1996 VL 145 BP 183 EP 191 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BF21C UT WOS:A1996BF21C00021 ER PT B AU Petre, R AF Petre, R BE McCray, R Wang, Z TI X-ray spectroscopy of supernova remnants SO SUPERNOVAE AND SUPERNOVA REMNANTS SE IAU COLLOQUIUM LA English DT Proceedings Paper CT International-Astronomical-Union Colloquium 145 on Supernovae and Supernova Remnants CY MAY 24-29, 1993 CL XIAN, PEOPLES R CHINA SP Int Astron Union, State Sci & Technol Commiss China, Basic Res Div, Chinese Acad Sci, Dept Math & Phys, Natl Nat Sci Fdn China, State Educ Commiss China, Chinese Astron Soc, Nanjing Univ, European So Observatory, Max Planck Fdn Germany, US NASA, Amer Astron Soc, US Natl Sci Fdn, Int Sci Fdn C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI CAMBRIDGE PA THE PITT BUILDING, TRUMPINGTON ST, CAMBRIDGE, CAMBS, ENGLAND CB2 1RP BN 0-521-46080-8 J9 IAU COLLOQ PY 1996 VL 145 BP 357 EP 368 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BF21C UT WOS:A1996BF21C00037 ER PT S AU McDaniel, PR StClair, TL AF McDaniel, PR StClair, TL BE Prokes, SM Cammarata, RC Wang, KL Christou, A TI Thermal and mechanical characteristics of polyimide based ceramers SO SURFACE/INTERFACE AND STRESS EFFECTS IN ELECTRONIC MATERIALS NANOSTRUCTURES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Surface/Interface and Stress Effects in Electronic Material Nanostructures, at the 1995 MRS Fall Meeting CY NOV 27-DEC 01, 1995 CL BOSTON, MA SP Mat Res Soc C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOC PI PITTSBURGH PA 9800 MCKNIGHT RD, SUITE 327, PITTSBURGH, PA 15237 SN 0272-9172 BN 1-55899-308-8 J9 MATER RES SOC SYMP P PY 1996 VL 405 BP 535 EP 539 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Physics, Applied SC Materials Science; Physics GA BG31L UT WOS:A1996BG31L00075 ER PT J AU Susskind, J AF Susskind, J GP AMER METEOROL SOC TI Preliminary examination of HIRS2/MSU data on upper, mid, and lower tropospheric temperatures SO SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT Symposium on Environmental Applications CY JAN 28-FEB 02, 1996 CL ATLANTA, GA SP Amer Meteorol Soc C1 NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1996 BP 201 EP 208 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BF41P UT WOS:A1996BF41P00051 ER PT J AU Hunley, JD AF Hunley, JD TI Science, technology and national socialism - Renneberg,M, Walker,M SO TECHNOLOGY AND CULTURE LA English DT Book Review RP Hunley, JD (reprint author), NASA,HIST PROGRAM,WASHINGTON,DC 20546, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0040-165X J9 TECHNOL CULT JI Technol. Cult. PD JAN PY 1996 VL 37 IS 1 BP 196 EP 197 DI 10.2307/3107224 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA UX906 UT WOS:A1996UX90600026 ER PT S AU Connell, JW Smith, JG Hergenrother, PM Rommel, M AF Connell, JW Smith, JG Hergenrother, PM Rommel, M BE Hoggatt, JT Falcone, A Nelson, KM Hill, SG TI Composite properties of cured phenylethynyl containing imide oligomers SO TECHNOLOGY TRANSFER IN A GLOBAL COMMUNITY SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 28th International SAMPE Technical Conference on Technology Transfer in a Global Community CY NOV 04-07, 1996 CL SEATTLE, WA SP Soc Adv Mat & Proc Engn DE high temperature polymers; polyimides; phenylethynyl containing imides; adhesives; carbon fiber composites; oligomeric thermosetting imides AB As part of a program to develop high performance/high temperature structural resins for aeronautical applications, imide oligomers with calculated number average molecular weights of similar to 5000 g/mole containing terminal phenylethynyl groups, pendent phenylethynyl groups and pendent and terminal phenylethynyl groups were prepared, characterized, thermally cured and the cured resins evaluated as adhesives and composite matrix resins. The objective of this work was to develop a resin system that is processable using conventional equipment into void free laminates, exhibits high mechanical properties with long term durability at ambient and elevated temperatures, and is unaffected by exposure to moisture and common aircraft fluids. The imide oligomers containing phenylethynyl groups were fabricated into titanium adhesive specimens, and composite specimens using IM-7 fiber under 1.4 MPa for 1 hr at 350-371 degrees C. The mechanical properties measured at room and elevated temperature varied depending on the phenylethynyl content. The neat resin and composite properties of these oligomers and their cured polymers will be presented. RP Connell, JW (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 843 W GLENTANA ST, PO BOX 2459, COVINA, CA 91722 SN 0892-2624 BN 0-938994-76-X J9 INT SAMPE TECH CONF PY 1996 VL 28 BP 14 EP 28 PG 3 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH03N UT WOS:A1996BH03N00002 ER PT S AU Pater, RH Ray, AK AF Pater, RH Ray, AK BE Hoggatt, JT Falcone, A Nelson, KM Hill, SG TI Thermal characterization of new high performance semi-interpenetrating polymer networks SO TECHNOLOGY TRANSFER IN A GLOBAL COMMUNITY SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 28th International SAMPE Technical Conference on Technology Transfer in a Global Community CY NOV 04-07, 1996 CL SEATTLE, WA SP Soc Adv Mat & Proc Engn DE high performance semi-interpenetrating polymer networks; LARC(TM)-RP 46; LARC(TM)-IA AB Thermosetting and thermoplastic polyimides have complementary physical/mechanical properties. While thermosetting polyimides are generally easier to process but more brittle, thermoplastic polyimides are harder to process but tougher. A combination of these two types of polyimides may help produce polymers more suitable for aerospace and other non-aerospace applications that require both easy processing and good toughness. Semi-interpenetrating polymer networks (semi-IPN's) of thermoset LARC(TM)-RP 46 and thermoplastic LARC(TM)-IA polyimides were prepared in weight percent ratios ranging from 100:0 to 0:100. Thermal analysis and dynamic mechanical analysis were made on these samples to correlate their chemical composition with physical/mechanical/morphological properties. As expected, the glass transition temperature increases with an increase in thermoset concentrations. The opposite is true for the thermo-oxidative stability. All the semi-IPN's showed unusually good phase-mixing. The resin density goes through a maximum at about 50:50 weight ratio, suggesting that the semi-IPN samples are not merely a solid solution of the two polymeric components. This non-linear behavior may be interpreted in terms of the existence of an electrostatic interaction between the two constituent polymers. RP Pater, RH (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 843 W GLENTANA ST, PO BOX 2459, COVINA, CA 91722 SN 0892-2624 BN 0-938994-76-X J9 INT SAMPE TECH CONF PY 1996 VL 28 BP 198 EP 206 PG 3 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH03N UT WOS:A1996BH03N00018 ER PT S AU Poe, CC AF Poe, CC BE Hoggatt, JT Falcone, A Nelson, KM Hill, SG TI Mechanics methodology for textile preform composite materials SO TECHNOLOGY TRANSFER IN A GLOBAL COMMUNITY SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 28th International SAMPE Technical Conference on Technology Transfer in a Global Community CY NOV 04-07, 1996 CL SEATTLE, WA SP Soc Adv Mat & Proc Engn DE textile composites; mechanical properties; test methods; analysis; data Base AB NASA and its contractors have completed a program to develop a basic mechanics underpinning for textile composites. Three major deliverables were produced by the program: 1. a set of test methods for measuring material properties and design allowables 2. mechanics models to predict the effects of the Fiber preform architecture and constituent properties on engineering moduli, strength, damage resistance, and fatigue life 3. an electronic data base of coupon type test data This report describes these three deliverables. RP Poe, CC (reprint author), NASA,LANGLEY RES CTR,MS 188E,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 843 W GLENTANA ST, PO BOX 2459, COVINA, CA 91722 SN 0892-2624 BN 0-938994-76-X J9 INT SAMPE TECH CONF PY 1996 VL 28 BP 324 EP 338 PG 3 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH03N UT WOS:A1996BH03N00030 ER PT S AU Dexter, HB AF Dexter, HB BE Hoggatt, JT Falcone, A Nelson, KM Hill, SG TI Innovative textile reinforced composite materials for aircraft structures SO TECHNOLOGY TRANSFER IN A GLOBAL COMMUNITY SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 28th International SAMPE Technical Conference on Technology Transfer in a Global Community CY NOV 04-07, 1996 CL SEATTLE, WA SP Soc Adv Mat & Proc Engn DE textile reinforced composites; braiding; knitting; stitching; resin film infusion; process modeling AB During the past 15 years NASA has taken the lead role in exploiting the benefits of textile reinforced composites for aircraft applications. Interim research results indicate that textile reinforced composites can save considerable cost and weight in wing and fuselage structural elements. Continued development and verification of this technology in full-scale wing and fuselage structures could lead to significant applications in next generation commercial transports. This paper discusses advanced material forms that have been developed, innovative machine concepts, and key technology advancements required for future application of textile reinforced composites in commercial transport aircraft. Multiaxial warp knitting, triaxial braiding, and through-the-thickness stitching are the three textile processes that have surfaced as the most promising for further development. Textile reinforced composite structural elements that have been developed in the NASA Advanced Composites Technology(ACT) Program are discussed. Included are braided fuselage frames and window-belt reinforcements, woven/stitched lower fuselage side panels, stitched multiaxial warp knit wing skins, and braided wing stiffeners. Analytical models to predict resin flow and cure in textile preforms are also discussed. Selected test results for braided and knitted/stitched materials are discussed. RP Dexter, HB (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 843 W GLENTANA ST, PO BOX 2459, COVINA, CA 91722 SN 0892-2624 BN 0-938994-76-X J9 INT SAMPE TECH CONF PY 1996 VL 28 BP 404 EP 416 PG 3 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH03N UT WOS:A1996BH03N00037 ER PT S AU Freeman, WT Siddiqi, S Edlow, R AF Freeman, WT Siddiqi, S Edlow, R BE Hoggatt, JT Falcone, A Nelson, KM Hill, SG TI COINS - COmposite INformation System multimedia database SO TECHNOLOGY TRANSFER IN A GLOBAL COMMUNITY SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 28th International SAMPE Technical Conference on Technology Transfer in a Global Community CY NOV 04-07, 1996 CL SEATTLE, WA SP Soc Adv Mat & Proc Engn AB COINS provides a set of modem, easily accessible electronic databases for preliminary/conceptual design integrated product teams. COINS databases emphasize the application of high performance composites to airframe structures. Extensive data including aircraft prices and technical details, material properties for state of the art and developmental materials, multimedia examples of machines and fabrication methods, and collections of lessons learned from 2 decades of composite applications are being included. COINS provides the convenience of Internet or modem access from any computer with Microsoft Office. RP Freeman, WT (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 843 W GLENTANA ST, PO BOX 2459, COVINA, CA 91722 SN 0892-2624 BN 0-938994-76-X J9 INT SAMPE TECH CONF PY 1996 VL 28 BP 427 EP 439 PG 3 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH03N UT WOS:A1996BH03N00039 ER PT S AU Jaworske, DA AF Jaworske, DA BE Hoggatt, JT Falcone, A Nelson, KM Hill, SG TI Emittance of thermal control materials between 100 and 400 K SO TECHNOLOGY TRANSFER IN A GLOBAL COMMUNITY SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 28th International SAMPE Technical Conference on Technology Transfer in a Global Community CY NOV 04-07, 1996 CL SEATTLE, WA SP Soc Adv Mat & Proc Engn DE thermal management; optical testing AB The hemispherical total emittances of several common thermal control tapes were evaluated calorimetrically over a wide temperature range. The calorimetric technique used here to evaluate thermal control materials allows a thermally isolated sample to cool solely through radiant heat transfer to a liquid nitrogen cooled cold wall. The mechanism of cooling is similar to that found in space, providing a functional evaluation of hemispherical total emittance. The five samples that were evaluated included several first and second surface mirrored Kapton tapes, one carbon-filled Kapton tape, and one black film. These tapes were adhesively bonded to an aluminum substrate, which provided the sensible heat for the calorimetric calculation. Temperature-time data were collected as heat flowed from the aluminum, through the adhesive layer, through the thermal control tape, and ultimately through the surface to the surroundings. Hemispherical total emittances were calculated over the temperature range of 100 to 400 K. RP Jaworske, DA (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 843 W GLENTANA ST, PO BOX 2459, COVINA, CA 91722 SN 0892-2624 BN 0-938994-76-X J9 INT SAMPE TECH CONF PY 1996 VL 28 BP 1080 EP 1084 PG 3 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH03N UT WOS:A1996BH03N00100 ER PT S AU Finckenor, MM Kamenetzky, RR Vaughn, JA Mell, R Sims, J Thompson, R LeMaster, P AF Finckenor, MM Kamenetzky, RR Vaughn, JA Mell, R Sims, J Thompson, R LeMaster, P BE Hoggatt, JT Falcone, A Nelson, KM Hill, SG TI Investigations of space environment effects on electrically conductive thermal control coatings at MSFC SO TECHNOLOGY TRANSFER IN A GLOBAL COMMUNITY SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 28th International SAMPE Technical Conference on Technology Transfer in a Global Community CY NOV 04-07, 1996 CL SEATTLE, WA SP Soc Adv Mat & Proc Engn DE space environment; thermal control; conductive coatings AB Electrically conductive thermal control coatings must maintain their electrical and optical properties in the space environment to ensure mission success. This paper details the investigations of electrically conductive coatings developed by AZ Technology for MSFC under contract NAS8-40557. Also included are the results of the RM400 coating development at MSFC for the Tethered Satellite System. Results from laboratory exposures of RM400 to atomic oxygen, ultraviolet radiation, thermal cycling, and other flight qualification data for both TSS-1 and TSS-1R missions are presented. Also included are post-flight analyses from the TSS-1 fight in August 1992 during the STS-46 mission. Emphasis of the program is on maintaining electrical conductivity, especially in vacuum, and the optical properties of solar absorptance and infrared emittance. Data from simulated space environment exposures at MSFC is presented for International Space Station candidate coatings. Also presented are results of pre-flight testing of a white and a black conductive coating selected for flight on the Passive Optical Sample Assembly-I experiment. RP Finckenor, MM (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 843 W GLENTANA ST, PO BOX 2459, COVINA, CA 91722 SN 0892-2624 BN 0-938994-76-X J9 INT SAMPE TECH CONF PY 1996 VL 28 BP 1085 EP 1094 PG 4 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH03N UT WOS:A1996BH03N00101 ER PT S AU Gaier, JR Davidson, ML Shively, RK AF Gaier, JR Davidson, ML Shively, RK BE Hoggatt, JT Falcone, A Nelson, KM Hill, SG TI Durability of intercalated graphite epoxy composites in low earth orbit SO TECHNOLOGY TRANSFER IN A GLOBAL COMMUNITY SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 28th International SAMPE Technical Conference on Technology Transfer in a Global Community CY NOV 04-07, 1996 CL SEATTLE, WA SP Soc Adv Mat & Proc Engn AB The electrical conductivity of graphite epoxy composites can be substantially increased by intercalating (inserting guest atoms or molecules between the graphene planes) the graphite fibers before composite formation. The resulting high strength, low density, electrically conducting composites have been proposed for EMI shielding in spacecraft. Questions have been raised, however, about their durability in the space environment, especially with respect to outgassing of the intercalates, which are corrosive species such as bromine. To answer those concerns, six samples of bromine intercalated graphite epoxy composites were included in the third Evaluation of Oxygen Interaction with Materials (EOIM-3) experiment flown on the Space Shuttle Discovery (STS-46). Changes in electrical conductivity, optical reflectance, surface texture, and mass loss for SiO2 protected and unprotected samples were measured after being exposed to the LEO environment for 42 hr. SiO2 protected samples showed no degradation, verifying conventional protection strategies are applicable to bromine intercalated composites. The unprotected samples showed that bromine intercalation does not alter the degradation of graphite-epoxy composites. No bromine was detected to have been released by the fibers, allaying fears that outgassing could be disruptive to the sensitive electronics the EMI shield is meant to protect. RP Gaier, JR (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 6 Z9 6 U1 0 U2 4 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 843 W GLENTANA ST, PO BOX 2459, COVINA, CA 91722 SN 0892-2624 BN 0-938994-76-X J9 INT SAMPE TECH CONF PY 1996 VL 28 BP 1136 EP 1147 PG 2 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH03N UT WOS:A1996BH03N00106 ER PT S AU Belvin, HL Cano, RJ Grenoble, RW Marchello, JM Claus, SJ AF Belvin, HL Cano, RJ Grenoble, RW Marchello, JM Claus, SJ BE Hoggatt, JT Falcone, A Nelson, KM Hill, SG TI Fabrication of composite tape from thermoplastic powder-impregnated tows SO TECHNOLOGY TRANSFER IN A GLOBAL COMMUNITY SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 28th International SAMPE Technical Conference on Technology Transfer in a Global Community CY NOV 04-07, 1996 CL SEATTLE, WA SP Soc Adv Mat & Proc Engn DE tape fabrication; thermoplastic; automated placement AB Recent automated manufacture of thermoplastic matrix composites has focused on the use of multi-tow heated head placement machines employing narrow consolidated ribbon. Use of narrow ribbon allows small turning radii and less edge scrap when cutting and adding individual tows. However, in applications where only moderate curvatures exist, such as aircraft wings and fuselages, narrow ribbon placement is inefficient Placement of wide tape is one way to achieve the high lay-down quantities per hour needed for commercial applications. Benefits also include fewer gaps and laps between sequentially placed material and correspondingly better quality. As part of ongoing composite materials forms research at NASA Langley Research Center, a previously developed process for making narrow thermoplastic ribbon was modified and extended to make a 7.6 cm (3 in)-wide tape. Improvements were made in tow heating, design of the holder for the stationary bars, and design of the contoured nip-rollers. A processing window for producing high quality well-consolidated tape was established. Tape samples were hand laid and compression molded into laminates that exhibited good mechanical properties. RP Belvin, HL (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 226,HAMPTON,VA 23681, USA. NR 0 TC 4 Z9 4 U1 1 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 843 W GLENTANA ST, PO BOX 2459, COVINA, CA 91722 SN 0892-2624 BN 0-938994-76-X J9 INT SAMPE TECH CONF PY 1996 VL 28 BP 1309 EP 1316 PG 4 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH03N UT WOS:A1996BH03N00123 ER PT B AU Parrish, JC AF Parrish, JC BE Stein, MR TI The Ranger Telerobotic Flight Experiment: A teleservicing system for on-orbit spacecraft SO TELEMANIPULATOR AND TELEPRESENCE TECHNOLOGIES III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Telemanipulator and Telepresence Technologies CY NOV 18-19, 1996 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers DE telerobotics; spacecraft servicing; neutral buoyancy; manipulator; impedance control; inverse kinematics; virtual reality AB The Ranger Telerobotic Flight Experiment is planned for launch into low Earth orbit an the Space Shuttle in 1998. During its mission, the Ranger space telerobot will demonstrate a wide variety of spacecraft servicing capabilities, and will set the stage for future telerobotic spacecraft servicing missions in Earth orbit. With four highly advanced robot manipulators and the capability for free flight in the space environment, the Ranger spacecraft will be able to perform on-orbit servicing tasks previously accomplishable only by astronauts. An underwater analog to the Ranger spacecraft has already been developed and is collecting data for comparison against the flight experiment data. It is anticipated that the results of the Ranger mission will lead to a new class of dexterous extravehicular telerobots for use in on-orbit spacecraft servicing operations. RP Parrish, JC (reprint author), NASA,WASHINGTON,DC 20546, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2303-3 J9 P SOC PHOTO-OPT INS PY 1996 VL 2901 BP 177 EP 185 DI 10.1117/12.263007 PG 9 WC Automation & Control Systems; Computer Science, Cybernetics; Optics SC Automation & Control Systems; Computer Science; Optics GA BG93Y UT WOS:A1996BG93Y00018 ER PT J AU Chen, TC Yen, MC Pfaendtner, J Sud, YC AF Chen, TC Yen, MC Pfaendtner, J Sud, YC TI Annual variation of the global precipitable water and its maintenance: Observation and climate-simulation SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article ID VAPOR FLUX AB The annual variation of the global-mean precipitable water [W] and the associated hydrological cycle were analyzed with the upper-air data generated by the Global Data Assimilation System of the National Meteorological Center for 1981-1991 and the European Centre for Medium Range Weather Forecasts from 1983-1991. It was found that the annual variation of [W] coincides with that of the Northern Hemisphere precipitable water [UT](NH). The hemispheric-mean ([])water budget analysis shows that water vapor is transported from the winter to the summer hemisphere across the equator by the Hadley circulation, and that the annual variations in the water vapor sink [P - E] for both hemispheres also follow the same seasonal march. The amplitudes of the annual variations in these two hydrological processes are comparable in both hemispheres. Thus, the annual variations of [W](NH) and [W](SH), are the result of slight imbalances between the cross-equator wafer vapor transport and the water vapor sink, particularly in the spring and fall. The climatological hemispheric-mean water budgets reveal that the Southern Hemisphere is a water vapor source and the Northern Hemisphere is a water vapor sink. The cross-equator water vapor transport constitutes a major source acting to maintain [W](NH), and in turn [W]. The hydrological mechanism maintaining the observed [W] annual variation is consistent with that obtained from the hydrological cycle in a 10-year (1979-1988) climate simulation done at the Goddard Laboratory for Atmospheres as part of their participation in the Atmospheric Model Intercomparison Project (AMIP). C1 NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771. RP Chen, TC (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT GEOL & ATMOSPHER SCI,AMES,IA 50011, USA. NR 16 TC 14 Z9 14 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6495 J9 TELLUS A JI Tellus Ser. A-Dyn. Meteorol. Oceanol. PD JAN PY 1996 VL 48 IS 1 BP 1 EP 16 DI 10.1034/j.1600-0870.1996.00001.x PG 16 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA TY523 UT WOS:A1996TY52300001 ER PT B AU Wilson, LF Nicol, DM AF Wilson, LF Nicol, DM GP IEEE TI Experiments in automated load balancing SO TENTH WORKSHOP ON PARALLEL AND DISTRIBUTED SIMULATION - PADS 96, PROCEEDINGS LA English DT Proceedings Paper CT 10th ACM/IEEE/SCS Workshop on Parallel and Distributed Simulation (PADS 96), at the Federated Computing Research Conference CY MAY 21-24, 1996 CL PHILADELPHIA, PA SP IEEE, Comp Soc, Tech Comm Simulat, Assoc Comp Machinery, Special Interest Grp Simulat, Soc Comp Simulat C1 NASA,LANGLEY RES CTR,INST COMP APPLICAT SCI & ENGN,HAMPTON,VA 23666. NR 0 TC 8 Z9 8 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 BN 0-8186-7539-X PY 1996 BP 4 EP 11 DI 10.1109/PADS.1996.761557 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BF75Q UT WOS:A1996BF75Q00001 ER PT J AU Heath, MJ Doyle, LR AF Heath, MJ Doyle, LR TI Planetary habitability studies go underground SO TERRA NOVA LA English DT Editorial Material ID OBLIQUITY C1 NASA,AMES RES CTR,SETI INST,MOFFETT FIELD,CA 94035. RP Heath, MJ (reprint author), GREENWICH COMMUNITY COLL,BIOSPHERES PROJECT,CORELLI RD,LONDON SE3 8EP,ENGLAND. NR 10 TC 1 Z9 1 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0954-4879 J9 TERRA NOVA JI Terr. Nova PY 1996 VL 8 IS 3 BP 301 EP 302 DI 10.1111/j.1365-3121.1996.tb00762.x PG 2 WC Geosciences, Multidisciplinary SC Geology GA UY300 UT WOS:A1996UY30000012 ER PT B AU Karasik, BS Skalare, A Wyss, RA McGrath, WR Bumble, B LeDuc, HG Barner, JB Kleinsasser, AW AF Karasik, BS Skalare, A Wyss, RA McGrath, WR Bumble, B LeDuc, HG Barner, JB Kleinsasser, AW BE Harrison, P TI Low-noise and wideband hot-electron superconductive mixers for THz frequencies SO THE NINETY EIGHT - 1998 IEEE SIXTH INTERNATIONAL CONFERENCE ON TERAHERTZ ELECTRONICS PROCEEDINGS LA English DT Proceedings Paper CT 6th IEEE International Conference on Terahertz Electronics CY SEP 03-04, 1998 CL UNIV LEEDS, LEEDS, ENGLAND SP IEEE, Univ Leeds HO UNIV LEEDS AB Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range from 1.1 THz to 2.5 THz The mixer device is a 0.15-0.3 mu m microbridge made from a 10 nm thick Nb film. This device employs diffusion as a cooling mechanism for hot electrons. The double sideband noise temperature was measured to be less than or equal to 3000 K at 2.5 THz and the mixer IF bandwidth is similar to 9-10 GHz for a 0.1 mu m long device. The local oscillator (LO) power dissipated In the HEB microbridge was 20-100 nW. Further improvement of the mixer characteristics can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated. The HEB mixer is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies. HEB receivers are planned for nse on the NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) and the ESA Far Infrared and Submillimeter Space Telescope (FIRST). The prospects of a submicron-size YBa2Cu3O7-delta (YBCO) HEB are also discussed. The expected LO power of 1-10 mu W and SSB noise temperature of similar to 2000 K may make this mixer attractive for various remote sensing applications. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Karasik, BS (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, 4800 Oak Grove Dr,M-S 168-314, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4903-2 PY 1996 BP 1 EP 4 PG 4 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BM17R UT WOS:000077911300001 ER PT B AU Gaidis, MC Pickett, HM Siegel, PH Smith, CD Smith, RP Martin, SC AF Gaidis, MC Pickett, HM Siegel, PH Smith, CD Smith, RP Martin, SC BE Harrison, P TI A 2.5 THz receiver front-end for spaceborne applications SO THE NINETY EIGHT - 1998 IEEE SIXTH INTERNATIONAL CONFERENCE ON TERAHERTZ ELECTRONICS PROCEEDINGS LA English DT Proceedings Paper CT 6th IEEE International Conference on Terahertz Electronics CY SEP 03-04, 1998 CL UNIV LEEDS, LEEDS, ENGLAND SP IEEE, Univ Leeds HO UNIV LEEDS AB The OH radical is an important player in known ozone depletion cycles; however, due to its location in the atmosphere, it must be studied from either a balloon or spaceborne platform. For long-term mapping over large portions of the earth, a spaceborne platform is the most desirable. NASA's Earth Observing System Microwave Limb Sounder instrument is slated to house a 2.5 THz Schottky-diode receiver for such measurements. Here we describe the design, fabrication, and testing of the engineering model receiver front end. This is the precursor to the first terahertz heterodyne receiver to be flown in space. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gaidis, MC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Gaidis, Michael/D-3327-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4903-2 PY 1996 BP 13 EP 17 PG 5 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BM17R UT WOS:000077911300004 ER PT J AU Weng, HY Lau, KM AF Weng, HY Lau, KM TI Low-frequency time-space regimes in tropical convection SO THEORETICAL AND APPLIED CLIMATOLOGY LA English DT Article; Proceedings Paper CT International Symposium on Global Change in Asia and Pacific Regions CY AUG 08-10, 1994 CL BEIJING, PEOPLES R CHINA SP Int Geosphere Biosphere Program, Chinese Natl Comm, Pacific Sci Assoc, Chinese Natl Comm, World Climate Res Program, Chinese Natl Comm ID OSCILLATION; VARIABILITY; PACIFIC AB The multi-scale time-space regimes of the low-frequency convective activity over the maritime continent and tropical western Pacific are investigated using the monthly infrared radiance black body temperature (IRTBB) over a latitude band of 5S-9S, 80E-160W for the time period of 1980-1993. The complex Morlet wavelet transform and the complex empirical orthogonal function (CEOF) analysis are used. The zonal mean of the monthly IRTBB is dominated by the annual cycle which is influenced by a monsoon regime. An interannual signal around the time scale of 4.8-year and a decadal signal are obvious. In the zonal deviation, each CEOF represents a particular spatial regime; its corresponding principal component exhibits different multi-scale temporal behavior. The first leading component represents the variability due to large scale land-ocean distribution (the maritime continent, the Indian Ocean and the western Pacific) related to monsoon, with a dominant annual time scale. The second leading component represents the fluctuation of Walker circulation, associated with the El Nino-Southern Oscillation (ENSO) events having a main time scale around 4.8-year and the quasi-biennial oscillation (QBO) around 2.4-year. The third leading component represents the variability due to small-scale land-ocean distribution (Java, New Guinea and the surrounding seas), with a dominant annual lime scale. The main time scales in all the components seem to be modulated by longer time scales in either amplitude or frequency or both. Different time scales, as well as their in-phase interference, may play different roles in developing an individual ENSO event. The 1982/1983 event is dominated by an enhanced QBO. The 1986/1987 event is dominated by an enhanced 4.8-year oscillation. The 1991 and 1993 events may have resulted from an in-phase interference among several interannual time scales, abnormal annual cycles, and also high-frequency variability. RP Weng, HY (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771, USA. RI Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 7 TC 2 Z9 4 U1 0 U2 1 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-798X J9 THEOR APPL CLIMATOL JI Theor. Appl. Climatol. PY 1996 VL 55 IS 1-4 BP 89 EP 98 DI 10.1007/BF00864704 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WA755 UT WOS:A1996WA75500007 ER PT J AU Daughtry, CST McMurtrey, JE Chappelle, EW Hunter, WJ Steiner, JL AF Daughtry, CST McMurtrey, JE Chappelle, EW Hunter, WJ Steiner, JL TI Measuring crop residue cover using remote sensing techniques SO THEORETICAL AND APPLIED CLIMATOLOGY LA English DT Article ID INDUCED FLUORESCENCE LIF; REFLECTANCE; SOILS; DECOMPOSITION; RATES AB Crop residues are managed under conservation tillage programs to leave as much as possible on the surface for minimization soil erosion and for improving water quality. Because current methods for measuring crop residue cover are tediuous and somewhat subjective, there is a need for new methods to measure residue cover that are rapid, accurate, and objective. We discuss the potential for discriminating crop residues from soils using reflectance and fluorescence techniques and examine experimentally the changes in wheat residue fluorescence during weathering. The fluorescence of crop residue was a board band phenomenon with emissions extending from 420 to 600 nm for excitation of 350-420 nm. Soils had low intensity broad band emissions over the 400-690 nm region for excitations of 300-600 nm. We found that the fluorescence intensities for the crop residues were much greater than the fluorescence of the soils, but as the crop residues decompose, their blue-green fluorescence intensities approach the fluorescence of the soils. We conclude that fluorescence techniques are less ambiguous and better suited for discriminating crop residues from soils than the reflectance methods. However, the potential problems, that must be addressed to implement the fluorescence technique, are (i) adequate excitation energy must be supplied to induce fluorescence and (ii) the fluorescence signal is small relative to normal, ambient sunlight. Nevertheless, if properly implemented, we believe that the fluorescence techniques can be used to quantify crop residue cover in field. C1 NASA,GODDARD SPACE FLIGHT CTR,TERR PHYS LAB,GREENBELT,MD 20771. ARS,USDA,SOIL PLANT NUTRIENT RES LAB,FT COLLINS,CO 80522. ARS,USDA,SO PIEDMONT CONSERVAT RES CTR,WATKINSVILLE,GA 30677. RP Daughtry, CST (reprint author), ARS,USDA,REMOTE SENSING & MODELING LAB,BLDG 7 BARC W,10300 BALTIMORE AVE,BELTSVILLE,MD 20705, USA. NR 37 TC 31 Z9 34 U1 0 U2 5 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-798X J9 THEOR APPL CLIMATOL JI Theor. Appl. Climatol. PY 1996 VL 54 IS 1-2 BP 17 EP 26 DI 10.1007/BF00863555 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UY038 UT WOS:A1996UY03800003 ER PT J AU Rubincam, DP AF Rubincam, DP TI Insolation in terms of Earth's orbital parameters - Reply SO THEORETICAL AND APPLIED CLIMATOLOGY LA English DT Article RP Rubincam, DP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,TERR PHYS LAB,GEODYNAM BRANCH,CODE 921,GREENBELT,MD 20771, USA. RI Rubincam, David/D-2918-2012 NR 1 TC 5 Z9 5 U1 0 U2 1 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-798X J9 THEOR APPL CLIMATOL JI Theor. Appl. Climatol. PY 1996 VL 53 IS 4 BP 257 EP 258 DI 10.1007/BF00871742 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UU556 UT WOS:A1996UU55600007 ER PT S AU Bune, AV Gillies, DC Lehoczky, SL AF Bune, AV Gillies, DC Lehoczky, SL BE Im, JS Park, B Greer, AL Stephenson, GB TI Optimization of bulk HgCdTe growth in a directional solidification furnace by numerical simulation SO THERMODYNAMICS AND KINETICS OF PHASE TRANSFORMATIONS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium C on Thermodynamics and Kinetics of Phase Transformations, at the 1995 MRS Fall Meeting CY NOV 27-DEC 01, 1995 CL BOSTON, MA SP Mat Res Soc C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RI Greer, Alan Lindsay/G-1977-2011 NR 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOC PI PITTSBURGH PA 9800 MCKNIGHT RD, SUITE 327, PITTSBURGH, PA 15237 SN 0272-9172 BN 1-55899-301-0 J9 MATER RES SOC SYMP P PY 1996 VL 398 BP 139 EP 144 PG 6 WC Thermodynamics; Materials Science, Multidisciplinary SC Thermodynamics; Materials Science GA BG31K UT WOS:A1996BG31K00020 ER PT B AU Cramer, KE Winfree, WP AF Cramer, KE Winfree, WP BE Burleigh, DD Spicer, JWM TI Thermal characterization of defects in aircraft structures via spatially controlled heat application SO THERMOSENSE XVIII: AN INTERNATIONAL CONFERENCE ON THERMAL SENSING AND IMAGING DIAGNOSTIC APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT International Conference on Thermal Sensing and Imaging Diagnostic Applications - Thermosense XVIII CY APR 10-12, 1996 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE thermography; infrared imaging; corrosion; aging aircraft; nondestructive inspection C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. NR 0 TC 4 Z9 4 U1 1 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2147-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2766 BP 202 EP 209 DI 10.1117/12.235376 PG 8 WC Construction & Building Technology; Engineering, Multidisciplinary; Instruments & Instrumentation; Optics SC Construction & Building Technology; Engineering; Instruments & Instrumentation; Optics GA BF31V UT WOS:A1996BF31V00022 ER PT B AU Winfree, WP Cramer, KE AF Winfree, WP Cramer, KE BE Burleigh, DD Spicer, JWM TI Computational pulse shaping for thermographic inspections SO THERMOSENSE XVIII: AN INTERNATIONAL CONFERENCE ON THERMAL SENSING AND IMAGING DIAGNOSTIC APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT International Conference on Thermal Sensing and Imaging Diagnostic Applications - Thermosense XVIII CY APR 10-12, 1996 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE nondestructive evaluation; nondestructive testing; thermographic inspections; laminated structures C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23861. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2147-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2766 BP 228 EP 235 DI 10.1117/12.235379 PG 8 WC Construction & Building Technology; Engineering, Multidisciplinary; Instruments & Instrumentation; Optics SC Construction & Building Technology; Engineering; Instruments & Instrumentation; Optics GA BF31V UT WOS:A1996BF31V00025 ER PT B AU Siebes, G Johnson, K McAffee, D AF Siebes, G Johnson, K McAffee, D BE Burleigh, DD Spicer, JWM TI Experience with an imaging infrared radiometer in a simulated space environment SO THERMOSENSE XVIII: AN INTERNATIONAL CONFERENCE ON THERMAL SENSING AND IMAGING DIAGNOSTIC APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT International Conference on Thermal Sensing and Imaging Diagnostic Applications - Thermosense XVIII CY APR 10-12, 1996 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE infrared imaging; space environment; testing; performance; applications C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2147-2 J9 P SOC PHOTO-OPT INS PY 1996 VL 2766 BP 316 EP 322 DI 10.1117/12.235387 PG 7 WC Construction & Building Technology; Engineering, Multidisciplinary; Instruments & Instrumentation; Optics SC Construction & Building Technology; Engineering; Instruments & Instrumentation; Optics GA BF31V UT WOS:A1996BF31V00035 ER PT S AU Tobiska, WK AF Tobiska, WK BE Rottger, J Wickwar, VB TI Current status of solar EUV measurements and modeling SO THERMOSPHERE-IONOSPHERE-MIDDLE ATMOSPHERE COUPLING AND DYNAMICS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT C1.2 Symposium of COSPAR Scientific Commission C on Thermosphere-Ionosphere-Middle Atmosphere Coupling and Dynamics, at the 30th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP COSPAR ID REFERENCE SPECTRUM; FLUX MODEL; IRRADIANCE AB EUV measurements, modeling, and prediction are a part of the body of information needed for detailing our grasp of what anthropogenic changes are now occurring to the upper atmosphere and ionosphere. Since the next set of full spectrum EUV measurements will likely not occur until the late 1990's, several empirical solar EUV models will help bridge the data gap. These models provide solar EUV flux estimates beyond the low, moderate, or high solar activity levels that are given by reference spectra. Each of the models provides important advantages for certain types of calculations and each model contains inherent weaknesses. An overview is presented of 3 of the primary reference spectra and the 5 principal models in use. Model reliability issues, a graphical comparison between models and rocket data, a description of the proxies used by each model, and examples of studies where EUV model fluxes are compared with ionospheric data are discussed. RP Tobiska, WK (reprint author), CALTECH, JET PROP LAB,NYMA,TELOS,4800 OAK GROVE DR, MS 264-765, PASADENA, CA 91109 USA. NR 23 TC 9 Z9 9 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042667-0 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 3 BP 3 EP 10 DI 10.1016/0273-1177(95)00827-2 PG 8 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Geology; Meteorology & Atmospheric Sciences GA BE40X UT WOS:A1995BE40X00001 ER PT J AU Mezin, A Lepage, J Abel, PB AF Mezin, A Lepage, J Abel, PB TI An analytical solution for non-steady-state diffusion through thin films SO THIN SOLID FILMS LA English DT Article DE diffusion; coatings; hydrogen; molybdenum ID HYDROGEN PERMEATION AB We present an analytical solution for non-steady-state diffusion in coated materials which assumes a constant gradient in the coating. The application domain and degree of validity are determined as a function of two appropriate parameters. Possible surface and interface effects are taken into account, as far as is consistent with boundary conditions of the first kind. The solution applies generally to thin films in which the diffusion equation prevails, whether to describe diffusion of a species or heat transfer by conduction. For example, this solution provides an easy tool for studying diffusion processes in multilayer materials in situ which is well adapted to the case of protective coatings. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP Mezin, A (reprint author), UNIV NANCY 1,INPL,LAB SCI & GENIE SURFACES,CNRS,URA 1402,ECOLE MINES,PARC SAURUPT,F-54042 NANCY,FRANCE. NR 12 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 1 PY 1996 VL 272 IS 1 BP 124 EP 131 DI 10.1016/0040-6090(95)06969-0 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA UE867 UT WOS:A1996UE86700024 ER PT J AU Mezin, A Lepage, J Abel, PB AF Mezin, A Lepage, J Abel, PB TI Hydrogen permeation properties of molybdenum coatings from absorption-desorption experiments SO THIN SOLID FILMS LA English DT Article DE hydrogen; molybdenum; coatings; diffusion AB The permeation properties of molybdenum coatings deposited as hydrogen diffusion barriers are studied. Absorption-desorption experiments with molybdenum-coated nickel substrates (previously published) are quantitatively interpreted using a non-steady-state analytical solution, developed in detail in a companion paper. Given the known solubility and diffusion coefficient of hydrogen in nickel, the effective permeation constant of the molybdenum coating is measured to be (8.4+/-2.5)X10(-16) and (37+/-13)X10(-16) m(2) s(-1) at at(-1) at 350 and 450 degrees C, respectively. Surface and interface effects are evident. While performing rather well as hydrogen diffusion barriers, the coatings exhibit about 9 (at 450 degrees C) or 17 (at 350 degrees C) times less protection than expected from literature diffusion data for bulk molybdenum. The relatively low efficacy of the molybdenum coating is attributed to material microdamage resulting from high internal stress. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP Mezin, A (reprint author), UNIV NANCY 1,INPL,LAB SCI & GENIE SURFACES,CNRS,URA 1402,ECOLE MINES,PARC SAURUPT,F-54042 NANCY,FRANCE. NR 15 TC 3 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 1 PY 1996 VL 272 IS 1 BP 132 EP 136 DI 10.1016/0040-6090(95)06970-4 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA UE867 UT WOS:A1996UE86700025 ER PT B AU Huber, E AF Huber, E GP IEEE COMP SOC TI 3-D real-time gesture recognition using proximity spaces SO THIRD IEEE WORKSHOP ON APPLICATIONS OF COMPUTER VISION - WACV '96, PROCEEDINGS LA English DT Proceedings Paper CT 3rd IEEE Workshop on Applications of Computer Vision (WACV 96) CY DEC 02-04, 1996 CL SARASOTA, FL SP IEEE Comp Soc Tech Comm Pattern Anal & Machine Intelligence AB A 3-D segment tracking approach to recognition of human pose and gestures is presented. In the past we have developed and refined a stereo based method called the Proximity Space method, for acquiring and maintaining track of object surfaces in 3-space. This method uses LoG filtered images and relies solely on stereo measurements to spatially distinguish between objects in 3D. The objective of this work is to obtain useful state information about the shape, size, and pose of natural (unadorned) objects in their naturally cluttered environments. Thus, our system does not require nor benefit from special markers, colors, or other tailored artifacts. Recently toe hate extended this method in order to track multiple regions and segments of complex objects. This paper describes techniques for applying the Prozimity Space method to a particularly interesting system: the human. Specifically, we discuss the use of simple models for constraining Prozimity Space behavior in order to track gestures as a person mettles through a cluttered environment. It is demonstrated that by observing the behavior of the model, used to track the human's pose through time, different gestures can be easily recognized. The approach is illustrated through a discussion of gestures used to provide logical and spatial commands to a mobile robot. RP Huber, E (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,METRICA INC ROBOT & AUTOMAT GRP,ER4,HOUSTON,TX 77058, USA. NR 0 TC 7 Z9 8 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 BN 0-8186-7620-5 PY 1996 BP 136 EP 141 DI 10.1109/ACV.1996.572020 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BG88X UT WOS:A1996BG88X00022 ER PT S AU Sauvaud, JA Jacquey, C Beutier, T Lepping, RP Russell, CT Belian, RJ Lui, ATY AF Sauvaud, JA Jacquey, C Beutier, T Lepping, RP Russell, CT Belian, RJ Lui, ATY BE Buchner, J TI Dynamics of the magnetospheric mid-tail induced by substorms; A multisatellite study SO THREE-DIMENSIONAL MAGNETOSPHERE SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D3 1 Symposium of COSPAR Scientific Commission D on the 3-Dimensional Magnetosphere, at the 30th COSPAR Scientific Assembly CY JUL 11-12, 1994 CL HAMBURG, GERMANY SP Comm Space Res, Int Assoc Geomagnetism & Aeron, Int Union Radio Sci, Inst Space & Astronaut Sci, Deut Agentur Fuer Raumfahrt Angelegenheiten ID NEAR-EARTH MAGNETOTAIL; CURRENT DISRUPTION; CURRENT SHEET; EXPANSION; INSTABILITY AB The dynamics of the mid-tail region during substorms is examined using multi-satellite measurements. This study shows that partial cross-tail current disruptions detected at radial distances of the order of 20 to 30 earth radii in the anti-solar direction, linked with a gross-scale decrease of the magnetic field of the tail, correspond to substorm onsets. The period which preceedes the onset is associated with a lobe magnetic field increase which is either due to an enhanced reconnection, as evidenced by concurrent southward turnings of the interplanetary magnetic field, or/and to an increase of the solar wind pressure. These two effects are shown to act together to the thinning of the plasma sheet which leads to substorm onset. It is also shown that multiple substorms can occur during an overall increase sequence of the magnetic field of the tail, which can be interpreted in the context of the control of the lobe magnetic field by the solar wind properties. C1 GSFC, GREENBELT, MD USA. UNIV CALIF LOS ANGELES, LOS ANGELES, CA USA. LANL, LOS ALAMOS, NM USA. JHU, APL, LAUREL, MD USA. RP Sauvaud, JA (reprint author), CTR ETUD SPATIALE RAYONNEMENTS, 9-11 AVE COL ROCHE, F-31400 TOULOUSE, FRANCE. OI Russell, Christopher/0000-0003-1639-8298 NR 13 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042674-3 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 8 BP 35 EP 43 DI 10.1016/0273-1177(95)00992-2 PG 9 WC Engineering, Aerospace; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Meteorology & Atmospheric Sciences; Remote Sensing GA BE73F UT WOS:A1995BE73F00005 ER PT S AU Vagina, LI Sergeev, VA Baker, DN Singer, HJ AF Vagina, LI Sergeev, VA Baker, DN Singer, HJ BE Buchner, J TI Use of mid-latitude magnetic data for modelling and diagnostics of magnetospheric substorms SO THREE-DIMENSIONAL MAGNETOSPHERE SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D3 1 Symposium of COSPAR Scientific Commission D on the 3-Dimensional Magnetosphere, at the 30th COSPAR Scientific Assembly CY JUL 11-12, 1994 CL HAMBURG, GERMANY SP Comm Space Res, Int Assoc Geomagnetism & Aeron, Int Union Radio Sci, Inst Space & Astronaut Sci, Deut Agentur Fuer Raumfahrt Angelegenheiten ID FIELD AB An inversion algorithm based on mid-latitude magnetic data has been developed for estimation of the intensity and longitudinal distribution of the substorm current wedge (SCW), partial ring current (DRP) and symmetric Ring Current (DR) during substorms. Here we summarize some past results of testing this algorithm and show how the longitudinal range of the SCW corresponds to the dipolarizations and particle injections observed at geostationary orbit. We conclude that in its present form the inversion algorithm is capable of obtaining the intensity as well as the longitudinal boundaries of the substorm current wedge (in the latter case with an accuracy better than 0.5 h MLT). C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NOAA, RSE, SPACE ENVIRONM LAB, BOULDER, CO 80303 USA. RP Vagina, LI (reprint author), ST PETERSBURG STATE UNIV, INST PHYS, ST PETERSBURG 198904, RUSSIA. RI Sergeev, Victor/H-1173-2013 OI Sergeev, Victor/0000-0002-4569-9631 NR 11 TC 6 Z9 6 U1 0 U2 3 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042674-3 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 8 BP 229 EP 232 DI 10.1016/0273-1177(95)00987-6 PG 4 WC Engineering, Aerospace; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Meteorology & Atmospheric Sciences; Remote Sensing GA BE73F UT WOS:A1995BE73F00033 ER PT B AU Ovryn, B Andrews, JH Eppell, SJ AF Ovryn, B Andrews, JH Eppell, SJ BE Cogswell, CJ Kino, GS Wilson, T TI Phase-measuring laser feedback interferometry: Applications to microscopy SO THREE-DIMENSIONAL MICROSCOPY: IMAGE ACQUISITION AND PROCESSING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Three-Dimensional Microscopy - Image Acquisition and Processing III CY JAN 30-FEB 01, 1996 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers C1 NASA,LEWIS RES CTR,NYMA INC,NASA LEWIS GRP,CLEVELAND,OH 44135. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2029-8 J9 P SOC PHOTO-OPT INS PY 1996 VL 2655 BP 153 EP 162 DI 10.1117/12.237491 PG 10 WC Instruments & Instrumentation; Microscopy; Optics SC Instruments & Instrumentation; Microscopy; Optics GA BF46V UT WOS:A1996BF46V00021 ER PT B AU Montgomery, K Ross, M AF Montgomery, K Ross, M BE Cogswell, CJ Kino, GS Wilson, T TI Non-fiducial, shape-based registration of biological tissue SO THREE-DIMENSIONAL MICROSCOPY: IMAGE ACQUISITION AND PROCESSING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Three-Dimensional Microscopy - Image Acquisition and Processing III CY JAN 30-FEB 01, 1996 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers DE registration; 3-D reconstruction; microscopy C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2029-8 J9 P SOC PHOTO-OPT INS PY 1996 VL 2655 BP 224 EP 232 DI 10.1117/12.237481 PG 9 WC Instruments & Instrumentation; Microscopy; Optics SC Instruments & Instrumentation; Microscopy; Optics GA BF46V UT WOS:A1996BF46V00028 ER PT J AU Yuan, Q Sun, DC Brewe, DE AF Yuan, Q Sun, DC Brewe, DE TI Effect of worm gear geometry on its contact properties SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 50th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 14-19, 1995 CL CHICAGO, IL SP Soc Tribologists & Lubricat Engineers DE gear lubrication; hydrodynamic lubrication; hydrostatic lubrication; contact mechanics; worm gears AB The research is aimed at implementing fluid film lubrication at the tooth contact of a worm gear transmission. As a prerequisite to the lubrication analysis, this paper is devoted to the study of worm gear geometry. A general methodology, the method of enveloping, is used to produce the worm gear geometry. Contact properties, particularly those which are needed in the lubrication analysis, are obtained. The influence of two geometrical parameters, i.e., the pressure angle and the apex angle, on the contact properties are discussed in detail. C1 NASA,LEWIS RES CTR,ARMY RES LAB,VEHICLE PROP DIRECTORATE,CLEVELAND,OH 44135. RP Yuan, Q (reprint author), SUNY BINGHAMTON,DEPT MECH ENGN,BINGHAMTON,NY 13902, USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 838 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0569-8197 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 1996 VL 39 IS 1 BP 139 EP 147 DI 10.1080/10402009608983513 PG 9 WC Engineering, Mechanical SC Engineering GA TQ202 UT WOS:A1996TQ20200018 ER PT J AU Morales, W AF Morales, W TI The decomposition of a commercial perfluoropolyalkylether on alpha and gamma catalytic aluminas SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 50th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 14-19, 1995 CL CHICAGO, IL SP Soc Tribologists & Lubricat Engineers DE aerospace tribology ID ELECTRON-BEAM; DEGRADATION; IRRADIATION AB The decomposition of a commercial perfluoropolyalkylether liquid lubricant (PFPE Z) was studied using a thermal gravimetric and differential scanning calorimetry unit. Small porous alumina pellets (alpha and gamma forms) were charged with approximately 5 mg of PFPE Z, and the charged pellets were then placed inside the thermal units where decomposition started to occur over the narrow temperature range of 198 degrees to 210 degrees C under a nitrogen atmosphere. At the end of a test, 1,1,2-trichlorotrifluoroethane solvent was used to extract PFPE Z and decomposition products from the pellets. This extract was analyzed using high-pressure liquid chromatography in the size exclusion mode. The alumina pellets were examined using X-ray photoelectron spectroscopy data support evidence that there are two different decomposition mechanisms for PFPE Z. The data indicated that active surface sites, other than Lewis acid sites, were responsible for PFPE Z decomposition. RP Morales, W (reprint author), NASA, LEWIS RES CTR, CLEVELAND, OH 44135 USA. NR 19 TC 16 Z9 16 U1 1 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 1996 VL 39 IS 1 BP 148 EP 156 DI 10.1080/10402009608983514 PG 9 WC Engineering, Mechanical SC Engineering GA TQ202 UT WOS:A1996TQ20200019 ER PT J AU Fellenstein, JA DellaCorte, C AF Fellenstein, JA DellaCorte, C TI A new tribological test for candidate brush seal materials evaluation SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 50th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 14-19, 1995 CL CHICAGO, IL SP Soc Tribologists & Lubricat Engineers DE seals; brush seals; gas turbine; wear test AB A new tribological test for candidate brush seal materials evaluation has been developed. The sliding contact between the brush seal wires and their mating counterface journal is simulated by testing a small tuft of wire against the outside diameter of a high speed rotating shaft. The test configuration is similar to standard block on ring geometry. The new tester provides the capability to measure both the friction and wear of candidate wire and counterface materials under controlled loading conditions in the gram to kilogram range. A wide range of test condition speeds (1 to 27 m/s), temperatures (25 degrees to 700 degrees C), and loads (0.5 to 10 N) enables the simulation of many of the important tribological parameters encountered by turbine engine brush seals. This paper describes the new test rig and specimen configuration and presents initial data for candidate seal materials comparing tuft test results and wear surface morphology to field tested seal components. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP Fellenstein, JA (reprint author), OHIO AEROSP INST,CLEVELAND,OH 44142, USA. NR 9 TC 8 Z9 8 U1 1 U2 3 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 838 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0569-8197 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 1996 VL 39 IS 1 BP 173 EP 179 DI 10.1080/10402009608983517 PG 7 WC Engineering, Mechanical SC Engineering GA TQ202 UT WOS:A1996TQ20200022 ER PT B AU Dietrich, DL Haggard, JB Dryer, FL Nayagam, V Shaw, BD Williams, FA AF Dietrich, DL Haggard, JB Dryer, FL Nayagam, V Shaw, BD Williams, FA BE Burgess, AR Dryer, FL TI Droplet combustion experiments in spacelab SO TWENTY-SIXTH SYMPOSIUM (INTERNATIONAL) ON COMBUSTION, VOLS 1 AND 2 LA English DT Proceedings Paper CT 26th International Symposium on Combustion CY JUL 28-AUG 02, 1996 CL NAPLES, ITALY SP Combust Inst, ALCOA Tech Ctr, Arthur D Little Inc, Chevron Res & Technol Co, Chevron Chem Co, CONSOL Inc, E I du Pont de Nemours & Co, Elect Power Res Inst, Engn Managements Consultants, EXXON Res & Engn Co, Factory Mutual Res Corp, Ford Motor Co, GE Corp Res & Dev Ctr, Owens, Brockway, Phillip Morris USA, Res Industries, Sawyer Associates, S Coast Air Quality Management Dist, SS Energy & Environm Int, United Technol Res Ctr, Ansaldo, Camera Commercio, Industria Artigianato, Consiglio Nazl Ricerche, ENEL CRT, ENI, Elsevier Sci Inc, FIAT CFR, Gordon & Breach Publicat Inc, Riello, Univ Federico II, Bric a Brac Napoi, Comune Napoli, ELASIS, Hewlett Packard Italian, Perkin Elmer Italia spa, Reg Campania ID METHANOL; EXTINCTION AB Individual droplets with diameters ranging from about 2 mm to 5 mm were burned under microgravity conditions in air at 1 bar with an ambient temperature of 300 K. Each droplet was tethered by a silicon carbide fiber of 80 mu m or 150 mu m diameter to keep it in view of video recording, and, in some tests, a forced air flow was applied in a direction parallel to the fiber axis. Methanol, two methanol-water mixtures, two methanol-dodecanol mixtures, and two heptane-hexadecane mixtures were the fuels. Droplet diameters were measured as functions of time, and they are compared here with existing theoretical predictions. The prediction that methanol droplets extinguish at diameters that increase with increasing initial droplet diameter is verified by these experiments. In addition, the quasi-steady burning-rate constant of the heptane-hexadecane mixtures appears to decrease with increasing droplet diameter; obscuration consistent with very heavy sooting, but without the formation of soot shells, is observed for the largest of these droplets. Forced convective dow around methanol droplets was found to increase the burning rate and to produce a ratio of downstream to upstream flame radius that remained constant as the droplet size decreased, a trend in agreement with earlier results obtained at higher convective velocities for smaller droplets having larger flame standoff ratios. Implications of the experimental results regarding droplet-combustion theory are discussed. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Dietrich, DL (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 22 TC 18 Z9 19 U1 0 U2 2 PU COMBUSTION INSTITUTE PI PITTSBURGH PA 5001 BAUM BLVD, SUITE 635, PITTSBURGH, PA 15213-1851 USA PY 1996 BP 1201 EP 1207 PG 7 WC Thermodynamics; Chemistry, Applied; Engineering, Multidisciplinary SC Thermodynamics; Chemistry; Engineering GA BN87U UT WOS:000083308500142 ER PT B AU King, MK AF King, MK BE Burgess, AR Dryer, FL TI An unsteady-state analysis of porous sphere and droplet fuel combustion under microgravity conditions SO TWENTY-SIXTH SYMPOSIUM (INTERNATIONAL) ON COMBUSTION, VOLS 1 AND 2 LA English DT Proceedings Paper CT 26th International Symposium on Combustion CY JUL 28-AUG 02, 1996 CL NAPLES, ITALY SP Combust Inst, ALCOA Tech Ctr, Arthur D Little Inc, Chevron Res & Technol Co, Chevron Chem Co, CONSOL Inc, E I du Pont de Nemours & Co, Elect Power Res Inst, Engn Managements Consultants, EXXON Res & Engn Co, Factory Mutual Res Corp, Ford Motor Co, GE Corp Res & Dev Ctr, Owens, Brockway, Phillip Morris USA, Res Industries, Sawyer Associates, S Coast Air Quality Management Dist, SS Energy & Environm Int, United Technol Res Ctr, Ansaldo, Camera Commercio, Industria Artigianato, Consiglio Nazl Ricerche, ENEL CRT, ENI, Elsevier Sci Inc, FIAT CFR, Gordon & Breach Publicat Inc, Riello, Univ Federico II, Bric a Brac Napoi, Comune Napoli, ELASIS, Hewlett Packard Italian, Perkin Elmer Italia spa, Reg Campania ID COEFFICIENTS AB Past experimental work has indicated that fuel droplets commonly burn in accordance with a law: derived from a quasi-steady-stare gas-phase (QS) model, that states that the square of the diameter of the burning droplet decreases linearly with time. However; the QS modeling approach also predicts that the ratio of flame radius to droplet radius will be constant during burning, inconsistent with experimental observation that the flame radius first increases and then decreases with time, with the ratio of flame radius to droplet radius increasing monotonically with time. In this paper a numerical analysis procedure has been used to relax the quasi-steady assumption while maintaining other assumptions and approximations of the QS model. It is found from these calculations that the gas behavior is very nearly quasi-steady at the droplet surface but deviates significantly from quasi-steady behavior out at the flame location, resulting in predictions in qualitative agreement with experimental observations. In addition, this modeling approach has been applied to analysis of combustion of liquid heptane fuel injected through a porous sphere at a rate equal to the rate at which it evaporates (no surface accumulation of liquid); these calculations also indicate rapid approach to quasi-steady behavior immediately adjacent to the porous sphere (leading to nearly steady fuel vaporization rate) but a much slower approach to quasi-steady behavior in the flame region (and thus slow approach to an asymptotic flame radius value). C1 NASA, Micrograv Sci & Applicat Div, Washington, DC 20546 USA. RP King, MK (reprint author), NASA, Micrograv Sci & Applicat Div, Code UG,300 E St SW, Washington, DC 20546 USA. NR 17 TC 7 Z9 8 U1 0 U2 0 PU COMBUSTION INSTITUTE PI PITTSBURGH PA 5001 BAUM BLVD, SUITE 635, PITTSBURGH, PA 15213-1851 USA PY 1996 BP 1227 EP 1234 PG 8 WC Thermodynamics; Chemistry, Applied; Engineering, Multidisciplinary SC Thermodynamics; Chemistry; Engineering GA BN87U UT WOS:000083308500145 ER PT B AU Ross, HD Miller, FJ AF Ross, HD Miller, FJ BE Burgess, AR Dryer, FL TI Detailed experiments of flame spread across deep butanol pools SO TWENTY-SIXTH SYMPOSIUM (INTERNATIONAL) ON COMBUSTION, VOLS 1 AND 2 LA English DT Proceedings Paper CT 26th International Symposium on Combustion CY JUL 28-AUG 02, 1996 CL NAPLES, ITALY SP Combust Inst, ALCOA Tech Ctr, Arthur D Little Inc, Chevron Res & Technol Co, Chevron Chem Co, CONSOL Inc, E I du Pont de Nemours & Co, Elect Power Res Inst, Engn Managements Consultants, EXXON Res & Engn Co, Factory Mutual Res Corp, Ford Motor Co, GE Corp Res & Dev Ctr, Owens, Brockway, Phillip Morris USA, Res Industries, Sawyer Associates, S Coast Air Quality Management Dist, SS Energy & Environm Int, United Technol Res Ctr, Ansaldo, Camera Commercio, Industria Artigianato, Consiglio Nazl Ricerche, ENEL CRT, ENI, Elsevier Sci Inc, FIAT CFR, Gordon & Breach Publicat Inc, Riello, Univ Federico II, Bric a Brac Napoi, Comune Napoli, ELASIS, Hewlett Packard Italian, Perkin Elmer Italia spa, Reg Campania ID LIQUID AB Experiments using simultaneous rainbow schlieren deflectometry, particle image velocimetry (PIV), infrared (IR) thermography, standard dame imaging, and thermocouples are conducted to reveal detailed physics of low-speed, forced-opposed-flow flame spread over Liquid pools. Our effort concentrates on the effects of gravity and air how speed on the flame-spread behavior across a deep, rectangular tray filled with 1-butanol. The microgravity (mu g) part of the experiment is the first combustion experiment conducted aboard a sounding rocket. Several novel observations are made: Even with forced-air velocities of the same order of magnitude as that induced naturally by buoyancy in normal gravity, the mu g dame behavior is completely different. Whereas the normal gravity (1 g) flames we studied are soot-producing, and pulsate and spread rapidly, the mg flames are free of soot and spread steadily and very slowly The rainbow schlieren measurements show that heat penetrates far deeper into the pool in mu g, suggesting that the major effect of liquid-phase buoyancy is its stratification of the temperature field in 1 g; its absence in mu g may lead to a very different liquid-phase surface temperature, how field, and flame-spread character. The IR thermography reveals heretofore unobserved liquid surface temperature and side-how phenomena in both 1 g and mg. PIV has been used for the first time to obtain quantitative, full-field, liquid-phase velocity fields ahead of the flame, revealing significantly more surface how in mg than in 1 g. A state-of-the-art model's predictions are qualitatively confirmed in regard to gravitational effects on dame shape, flame extinction in mu g when there is no opposed air flow and fuel consumption rate. Disagreement is found in the flame spread character in mu g, unless hat gas expansion is artificially set to zero. C1 NASA, Lewis Res Ctr, Micrograv Combust Branch, Cleveland, OH 44135 USA. RP Ross, HD (reprint author), NASA, Lewis Res Ctr, Micrograv Combust Branch, MS 500-115, Cleveland, OH 44135 USA. NR 19 TC 12 Z9 17 U1 0 U2 0 PU COMBUSTION INSTITUTE PI PITTSBURGH PA 5001 BAUM BLVD, SUITE 635, PITTSBURGH, PA 15213-1851 USA PY 1996 BP 1327 EP 1334 PG 8 WC Thermodynamics; Chemistry, Applied; Engineering, Multidisciplinary SC Thermodynamics; Chemistry; Engineering GA BN87U UT WOS:000083308500157 ER PT B AU Stocker, DP Olson, SL Urban, DL Torero, JL Walther, DC Fernandez-Pello, AC AF Stocker, DP Olson, SL Urban, DL Torero, JL Walther, DC Fernandez-Pello, AC BE Burgess, AR Dryer, FL TI Small-scale smoldering combustion experiments in microgravity SO TWENTY-SIXTH SYMPOSIUM (INTERNATIONAL) ON COMBUSTION, VOLS 1 AND 2 LA English DT Proceedings Paper CT 26th International Symposium on Combustion CY JUL 28-AUG 02, 1996 CL NAPLES, ITALY SP Combust Inst, ALCOA Tech Ctr, Arthur D Little Inc, Chevron Res & Technol Co, Chevron Chem Co, CONSOL Inc, E I du Pont de Nemours & Co, Elect Power Res Inst, Engn Managements Consultants, EXXON Res & Engn Co, Factory Mutual Res Corp, Ford Motor Co, GE Corp Res & Dev Ctr, Owens, Brockway, Phillip Morris USA, Res Industries, Sawyer Associates, S Coast Air Quality Management Dist, SS Energy & Environm Int, United Technol Res Ctr, Ansaldo, Camera Commercio, Industria Artigianato, Consiglio Nazl Ricerche, ENEL CRT, ENI, Elsevier Sci Inc, FIAT CFR, Gordon & Breach Publicat Inc, Riello, Univ Federico II, Bric a Brac Napoi, Comune Napoli, ELASIS, Hewlett Packard Italian, Perkin Elmer Italia spa, Reg Campania AB Results from small-scale experiments of the smolder characteristics of a porous combustible material (flexible polyurethane foam) in microgravity and normal gravity are presented. The microgravity experiments were conducted in the Spacelab Glovebox on the USML-1 mission of the Space Shuttle Columbia, June/July 1992, and represent the first smolder experiments ever conducted under extended periods of microgravity. The use of the Glovebox limited the size of the fuel sample that could be tested and the power available for ignition but provided the opportunity to conduct such experiments in space. Four tests were conducted, varying the igniter geometry (axial and plate) and the convective environment (quiescent and forced). A series of comparative tests was also conducted in normal gravity measurements conducted included temperature histories at several locations along the fuel sample, video recording of the progress of the smolder and postcombustion char and gas composition analyses. The results of the tests showed that smolder did not propagate without the assistance of the igniter, primarily because of heat lasses from the reaction to the surrounding environment. In microgravity, the reduced heat losses caused by the absence of natural convection resulted in only slightly higher temperatures in the quiescent microgravity test than in normal gravity but a dramatically larger production of combustion products in all microgravity tests. Particularly significant is the proportionately larger amount of carbon monoxide and light organic compounds produced in microgravity, despite comparable temperatures and similar char patterns. This excessive production of fuel-rich combustion products may be a generic characteristic of smoldering polyurethane in microgravity, with an associated increase in the toxic hazard of smolder in spacecraft. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Stocker, DP (reprint author), NASA, Lewis Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 10 TC 4 Z9 4 U1 1 U2 1 PU COMBUSTION INSTITUTE PI PITTSBURGH PA 5001 BAUM BLVD, SUITE 635, PITTSBURGH, PA 15213-1851 USA PY 1996 BP 1361 EP 1368 PG 8 WC Thermodynamics; Chemistry, Applied; Engineering, Multidisciplinary SC Thermodynamics; Chemistry; Engineering GA BN87U UT WOS:000083308500161 ER PT B AU Bellan, J Harstad, K AF Bellan, J Harstad, K BE Burgess, AR Dryer, FL TI Electrostatic dispersion and evaporation of clusters of drops of high-energy fuel for soot control SO TWENTY-SIXTH SYMPOSIUM (INTERNATIONAL) ON COMBUSTION, VOLS 1 AND 2 LA English DT Proceedings Paper CT 26th International Symposium on Combustion CY JUL 28-AUG 02, 1996 CL NAPLES, ITALY SP Combust Inst, ALCOA Tech Ctr, Arthur D Little Inc, Chevron Res & Technol Co, Chevron Chem Co, CONSOL Inc, E I du Pont de Nemours & Co, Elect Power Res Inst, Engn Managements Consultants, EXXON Res & Engn Co, Factory Mutual Res Corp, Ford Motor Co, GE Corp Res & Dev Ctr, Owens, Brockway, Phillip Morris USA, Res Industries, Sawyer Associates, S Coast Air Quality Management Dist, SS Energy & Environm Int, United Technol Res Ctr, Ansaldo, Camera Commercio, Industria Artigianato, Consiglio Nazl Ricerche, ENEL CRT, ENI, Elsevier Sci Inc, FIAT CFR, Gordon & Breach Publicat Inc, Riello, Univ Federico II, Bric a Brac Napoi, Comune Napoli, ELASIS, Hewlett Packard Italian, Perkin Elmer Italia spa, Reg Campania AB A model is presented for the electrostatic dispersion of a polydisperse cluster of evaporating drops embedded into an inviscid vortex. Results from this model obtained for dense clusters of drops show that electrostatic dispersion decreases the mass fraction of the evaporating compound as well as the gas density inside the cluster Since the sooting tendency of a fuel (through coagulation) is an increasing function of the partial density of the fuel vapor, it is inferred that electrostatic charging decreases the sooting tendency. Results indicate that the sooting tendency is a monotonically decreasing function of the charge. By using this model for different fuels, it is shown that the sooting tendency of a fuel is associated with two competing characteristic times: that of drop dispersion and that of drop evaporation. It is also shown that the drop evaporation time is directly related to the latent heat of the fuel, thereby providing a simple way to relate sooting propensity to fuel-specific properties. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bellan, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 21 TC 2 Z9 2 U1 0 U2 0 PU COMBUSTION INSTITUTE PI PITTSBURGH PA 5001 BAUM BLVD, SUITE 635, PITTSBURGH, PA 15213-1851 USA PY 1996 BP 1713 EP 1722 PG 10 WC Thermodynamics; Chemistry, Applied; Engineering, Multidisciplinary SC Thermodynamics; Chemistry; Engineering GA BN87U UT WOS:000083308500202 ER PT B AU Vander Wal, RL AF Vander Wal, RL BE Burgess, AR Dryer, FL TI Soot precursor material: Visualization via simultaneous LIF-LII and characterization via TEM SO TWENTY-SIXTH SYMPOSIUM (INTERNATIONAL) ON COMBUSTION, VOLS 1 AND 2 LA English DT Proceedings Paper CT 26th International Symposium on Combustion CY JUL 28-AUG 02, 1996 CL NAPLES, ITALY SP Combust Inst, ALCOA Tech Ctr, Arthur D Little Inc, Chevron Res & Technol Co, Chevron Chem Co, CONSOL Inc, E I du Pont de Nemours & Co, Elect Power Res Inst, Engn Managements Consultants, EXXON Res & Engn Co, Factory Mutual Res Corp, Ford Motor Co, GE Corp Res & Dev Ctr, Owens, Brockway, Phillip Morris USA, Res Industries, Sawyer Associates, S Coast Air Quality Management Dist, SS Energy & Environm Int, United Technol Res Ctr, Ansaldo, Camera Commercio, Industria Artigianato, Consiglio Nazl Ricerche, ENEL CRT, ENI, Elsevier Sci Inc, FIAT CFR, Gordon & Breach Publicat Inc, Riello, Univ Federico II, Bric a Brac Napoi, Comune Napoli, ELASIS, Hewlett Packard Italian, Perkin Elmer Italia spa, Reg Campania ID LASER-INDUCED INCANDESCENCE; AROMATIC-HYDROCARBONS; DIFFUSION FLAMES; VOLUME FRACTION; FLUORESCENCE; DIAGNOSTICS; PYROLYSIS AB Simultaneous combined laser-induced fluorescence and laser-induced incandescence (LIF-LII) images are presented for both a normal and inverse diffusion flame. The excitation wavelength dependence distinguishes the LIF and LII signals in images from the normal diffusion flame while the temporal decay distinguishes the signals in images of the inverse diffusion flame. Each flame presents a minimum in the combined LIF-LII intensity in a region separating the fuel pyrolysis and soot containing regions. Opacity, geometric definition, and extent of crystallinity measured through bath bright and dark field transmission electron microscopy (TEM) characterizes the thermophoretically sampled material from within this minimal LIF-LII intensity region. TEM analysis reveals rather different soot processes occurring within the normal and inverse diffusion flame. In the normal diffusion flame, rapid chemical and physical coalescence of PAHs results in initial formation of soot precursor particles that are highly crystalline and evolve toward fully formed soot. In the inverse diffusion flame, rapid coalescence of pyrolysis products occurs, producing tarlike, globular structures equivalent in size to fully formed soot aggregates but with markedly less crystallinity than normal-appearing soot. These different material properties are interpreted as reflecting different relative rates of chemical and physical coalescence of fuel pyrolysis products versus carbonization. Significantly, these TEM images support qualitative photophysical arguments suggesting that, in general, this "dark" region observed in the LIF-LII images demarcates a transitional region in which a fundamental change in the material chemical/physical properties occurs between solid carbonaceous soot and condensed or gaseous molecular growth material. C1 NASA Lewis, Cleveland, OH 44135 USA. RP Vander Wal, RL (reprint author), NASA Lewis, Cleveland, OH 44135 USA. NR 38 TC 10 Z9 10 U1 0 U2 2 PU COMBUSTION INSTITUTE PI PITTSBURGH PA 5001 BAUM BLVD, SUITE 635, PITTSBURGH, PA 15213-1851 USA PY 1996 BP 2269 EP 2275 PG 7 WC Thermodynamics; Chemistry, Applied; Engineering, Multidisciplinary SC Thermodynamics; Chemistry; Engineering GA BN87U UT WOS:000083308500266 ER PT S AU Cucinotta, FA Katz, R Wilson, JW Dubey, RR AF Cucinotta, FA Katz, R Wilson, JW Dubey, RR BE Gay, TJ Starace, AF TI Radial dose distributions in the delta-ray theory of track structure SO TWO-CENTER EFFECTS IN ION-ATOM COLLISIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium in Honor of M Eugene Rudd on 2-Center Effects in Ion-Atom Collisions CY MAY 13-14, 1994 CL LINCOLN, NE C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-342-6 J9 AIP CONF PROC PY 1996 IS 362 BP 245 EP 265 PG 21 WC Physics, Atomic, Molecular & Chemical SC Physics GA BF24V UT WOS:A1996BF24V00021 ER PT B AU Joiner, J Bhartia, PK Hilsenrath, E AF Joiner, J Bhartia, PK Hilsenrath, E BE Huffman, RE Stergis, CG TI Remote sensing applications of continuous spectral backscatter ultraviolet measurements SO ULTRAVIOLET ATMOSPHERIC AND SPACE REMOTE SENSING: METHODS AND INSTRUMENTATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Atmospheric and Space Remote Sensing - Methods and Instrumentation CY AUG 07-08, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, N Amer Remote Sensing Ind Assoc, Amer Soc Photogrammetry & Remote Sensing DE ultraviolet; satellite remote sensing; rotational-Raman scattering; ozone; calibration; clouds AB We discuss several new uses of backscatter ultraviolet (UV) measurements in atmospheric remote sensing. Radiances in the UV from 310-340 nm are primarily sensitive to total ozone and the effects of clouds and the Earth's surface. We have modeled UV radiances in this spectral range to an accuracy of approximately 0.5% with an efficient radiative transfer model. We have retrieved accurate values of total ozone using continuous spectral scan mode data from the Nimbus 7 Satellite Backscatter Ultraviolet (SBUV) spectrometer. Systematic effects resulting from calibration and algorithmic errors have been removed. The continuous scan mode total ozone measurements serve as independent validation of total ozone measurements and trends derived from TOMS and SBUV discrete mode, both of which have better temporal and spatial coverage than SBUV continuous scan mode but fewer channels. At wavelengths between 340 and 400 nm, radiances are sensitive to several properties of clouds and aerosols. We have used rotational-Raman scattering signatures near 360 nm and at the 394 nm calcium solar Fraunhofer line to determine effective UV cloud pressures with both TOMS and SBUV in continuous scan mode. At 280 nm, resonance scattering from magnesium ions has been detected. Spatial and temporal variations in magnesium ion column abundances, including increases with increased solar activity, have been derived from SEW continuous scan measurements. RP Joiner, J (reprint author), GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771, USA. RI Joiner, Joanna/D-6264-2012 NR 0 TC 0 Z9 0 U1 1 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2219-3 J9 P SOC PHOTO-OPT INS PY 1996 VL 2831 BP 94 EP 103 DI 10.1117/12.257188 PG 10 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BG73K UT WOS:A1996BG73K00007 ER PT S AU Dwek, E AF Dwek, E BE Blitz, L Teuben, P TI Morphology of the galactic bulge from COBE DIRBE observations SO UNSOLVED PROBLEMS OF THE MILKY WAY SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 169th Symposium of the International-Astronomical-Union on Unsolved Problems of the Milky Way CY AUG 23-29, 1994 CL THE HAGUE, NETHERLANDS SP Int Astron Union ID STELLAR BARS; MILKY-WAY; GALAXY; MODELS; IRAS; GAS RP Dwek, E (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CODE 685, GREENBELT, MD 20771 USA. NR 30 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4039-6 J9 IAU SYMP PY 1996 IS 169 BP 61 EP 69 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BG01P UT WOS:A1996BG01P00009 ER PT S AU Ozernoy, LM Genzel, R AF Ozernoy, LM Genzel, R BE Blitz, L Teuben, P TI IS SGR A* underfed, underefficient, or underdone? Why the Milky Way galaxy is not a Seyfert galaxy? SO UNSOLVED PROBLEMS OF THE MILKY WAY SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 169th Symposium of the International-Astronomical-Union on Unsolved Problems of the Milky Way CY AUG 23-29, 1994 CL THE HAGUE, NETHERLANDS SP Int Astron Union ID ACCRETION AB We argue that the wind from IRS 16 and He I stars in the central 1 pc of the Galaxy is responsible for the peculiar features of accretion onto a putative black hole at the Galactic center. What makes Sgr A(star) unique is not that it is just underfed but, in addition, it has a much lower efficiency of accretion and possibly a lower mass, compared to the AGN case. C1 GEORGE MASON UNIV, DEPT PHYS, FAIRFAX, VA 22030 USA. NASA, GODDARD SPACE FLIGHT CTR, ASTRON & SOLAR PHYS LAB, GREENBELT, MD 20771 USA. MAX PLANCK INST EXTRATERR PHYS, D-37075 GARCHING, GERMANY. RP Ozernoy, LM (reprint author), GEORGE MASON UNIV, INST COMPUTAT SCI & INFORMAT, FAIRFAX, VA 22030 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4039-6 J9 IAU SYMP PY 1996 IS 169 BP 181 EP 187 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BG01P UT WOS:A1996BG01P00022 ER PT S AU Ozernoy, LM AF Ozernoy, LM BE Blitz, L Teuben, P TI Recurrent starbursts or intermittent starburst/AGN phenomena at the Galactic center? SO UNSOLVED PROBLEMS OF THE MILKY WAY SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 169th Symposium of the International-Astronomical-Union on Unsolved Problems of the Milky Way CY AUG 23-29, 1994 CL THE HAGUE, NETHERLANDS SP Int Astron Union ID GALAXY AB Recently, I summarized arguments, both old and new that the Galactic center has experienced a starburst in a recent past (Ozernoy 1994a). Here I propose a likely mechanism - collisions between giant molecular clouds - that might induce (recurrent) starbursts. Taken together, these two approaches seem to indicate that the history of the central part of our Galaxy can be described as recurrent starbursts or intermittent Seyfert activities/starbursts. C1 GEORGE MASON UNIV, DEPT PHYS, FAIRFAX, VA 22030 USA. NASA, GODDARD SPACE FLIGHT CTR, ASTRON & SOLAR PHYS LAB, GREENBELT, MD 20771 USA. RP Ozernoy, LM (reprint author), GEORGE MASON UNIV, INST COMPUTAT SCI & INFORMAT, FAIRFAX, VA 22030 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4039-6 J9 IAU SYMP PY 1996 IS 169 BP 189 EP 192 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BG01P UT WOS:A1996BG01P00023 ER PT S AU Gezari, D Dwek, E Varosi, F AF Gezari, D Dwek, E Varosi, F BE Blitz, L Teuben, P TI Mid-infrared (4.8-12.4 and 20.0 mu m) imaging of the Galactic Center: Modeling the dust emission and energetics of the central parsec SO UNSOLVED PROBLEMS OF THE MILKY WAY SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 169th Symposium of the International-Astronomical-Union on Unsolved Problems of the Milky Way CY AUG 23-29, 1994 CL THE HAGUE, NETHERLANDS SP Int Astron Union ID SAGITTARIUS-A; ARRAY CAMERA; LUMINOSITY AB We have modeled the mid-infrared emission from the Galactic Center using our array camera images at eight wavelengths. The results suggest that the high infrared luminosity of the region is provided by a cluster of luminous stars. There is no direct indication in the new model resuits of a very luminous object or ''central engine'' near Sgr A*. RP Gezari, D (reprint author), NASA, GODDARD SPACE FLIGHT CTR, INFRARED ASTROPHYS BRANCH, CODE 685, GREENBELT, MD 20771 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4039-6 J9 IAU SYMP PY 1996 IS 169 BP 231 EP + PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BG01P UT WOS:A1996BG01P00029 ER PT S AU Reach, WT AF Reach, WT BE Blitz, L Teuben, P TI Far-infrared spectral observations of the galaxy by the far-infrared absolute spectrophotometer SO UNSOLVED PROBLEMS OF THE MILKY WAY SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 169th Symposium of the International-Astronomical-Union on Unsolved Problems of the Milky Way CY AUG 23-29, 1994 CL THE HAGUE, NETHERLANDS SP Int Astron Union ID COBE AB The Galactic continuum spectrum from 5-96 cm(-1) is derived from COBE(1) /FIRAS observations. The spectra are dominated by warm dust emission, which may be fit with a single temperature along each line of sight in the range 16-21 K. A widespread, very cold component (4-7 K) with optical depth that is spatially correlated with the warm component is also detected. The nature of the cold component and its implications for the amount of very cold material in the Milky Way are discussed. RP Reach, WT (reprint author), NASA, GODDARD SPACE FLIGHT CTR, UNIV SPACE RES CORP, CODE 685, GREENBELT, MD 20771 USA. RI Reach, William/C-4710-2008 NR 9 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4039-6 J9 IAU SYMP PY 1996 IS 169 BP 567 EP 573 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BG01P UT WOS:A1996BG01P00090 ER PT S AU Petuchowski, SJ Bennett, CL AF Petuchowski, SJ Bennett, CL BE Blitz, L Teuben, P TI Neutral gas contributions to [S II] Galactic background emission SO UNSOLVED PROBLEMS OF THE MILKY WAY SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 169th Symposium of the International-Astronomical-Union on Unsolved Problems of the Milky Way CY AUG 23-29, 1994 CL THE HAGUE, NETHERLANDS SP Int Astron Union ID REMNANTS RP Petuchowski, SJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4039-6 J9 IAU SYMP PY 1996 IS 169 BP 613 EP 614 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BG01P UT WOS:A1996BG01P00099 ER PT S AU Rubin, RH Ferland, GJ Dufour, RJ Walter, DK ODell, CR Baldwin, JA Hester, JJ Martin, PG AF Rubin, RH Ferland, GJ Dufour, RJ Walter, DK ODell, CR Baldwin, JA Hester, JJ Martin, PG BE Blitz, L Teuben, P TI HST spectroscopy of the Orion Nebula SO UNSOLVED PROBLEMS OF THE MILKY WAY SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 169th Symposium of the International-Astronomical-Union on Unsolved Problems of the Milky Way CY AUG 23-29, 1994 CL THE HAGUE, NETHERLANDS SP Int Astron Union ID COLLISION STRENGTHS; ULTRAVIOLET; GAS AB From our recent Faint Object Spectrograph (FOS) observations of the Orion Nebula obtained with the Hubble Space Telescope, we present preliminary results that address the nitrogen abundance, The List of detected lines and their identifications included the first measurement of the N II] 2142 Angstrom line in an H II region, This measurement in conjunction with [O II] 2471 Angstrom permits a new assessment of the important N/O ratio in Orion, Unfortunately, the measurements of the N III] 1747-54 Angstrom multiplet and the O III] 1660-66 Angstrom multiplet have poor signal-to-noise, precluding another independent derivation of N/O. C1 UNIV KENTUCKY,LEXINGTON,KY 40506. RICE UNIV,HOUSTON,TX 77251. ARIZONA STATE UNIV,TEMPE,AZ 85287. UNIV TORONTO,TORONTO,ON,CANADA. RP Rubin, RH (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. OI Ferland, Gary/0000-0003-4503-6333 NR 12 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4039-6 J9 IAU SYMP PY 1996 IS 169 BP 629 EP 632 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BG01P UT WOS:A1996BG01P00107 ER PT S AU Hauser, MG AF Hauser, MG BE Dwek, E TI Searching for the cosmic infrared background SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 11 EP 21 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00003 ER PT S AU Reach, WT Franz, BA Kelsall, T Weiland, JL AF Reach, WT Franz, BA Kelsall, T Weiland, JL BE Dwek, E TI DIRBE observations of the zodiacal light SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GSFC,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. NR 0 TC 5 Z9 5 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 37 EP 46 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00005 ER PT S AU Weiland, JL Arendt, RG Sodroski, TJ AF Weiland, JL Arendt, RG Sodroski, TJ BE Dwek, E TI The interstellar dust contribution to the diffuse infrared sky brightness SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,GEN SCI CORP,GREENBELT,MD 20771. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 74 EP 80 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00009 ER PT S AU Veeraraghavan, S AF Veeraraghavan, S BE Dwek, E TI Near infrared background correlations SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 122 EP 126 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00015 ER PT S AU Stecker, FW AF Stecker, FW BE Dwek, E TI On the determination of the IR background from extragalactic TeV gamma-ray absorption SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. RI Stecker, Floyd/D-3169-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 181 EP 190 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00023 ER PT S AU Dwek, E Varosi, F AF Dwek, E Varosi, F BE Dwek, E TI The effects of dust and metallicity evolution on the cosmic infrared background SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 237 EP 248 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00030 ER PT S AU Mather, JC Beichman, CA AF Mather, JC Beichman, CA BE Dwek, E TI Egbirt and desire: Measuring the CIBR at 3 AU SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 271 EP 277 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00033 ER PT S AU Leisawitz, D AF Leisawitz, D BE Dwek, E TI An overview of the DIRBE and FIRAS data products SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 287 EP 291 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00035 ER PT S AU Berriman, GB Weiland, JL Lisse, CM Reach, WT Hauser, MG Kelsall, T AF Berriman, GB Weiland, JL Lisse, CM Reach, WT Hauser, MG Kelsall, T BE Dwek, E TI The near-infrared scattering properties of interplanetary dust SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,GEN SCI CORP,GREENBELT,MD 20771. RI Lisse, Carey/B-7772-2016 OI Lisse, Carey/0000-0002-9548-1526 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 292 EP 295 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00036 ER PT S AU Franz, BA Reach, WT Kelsall, T Weiland, JL AF Franz, BA Reach, WT Kelsall, T Weiland, JL BE Dwek, E TI Inversion of the DIRBE photometry to derive the three dimensional distribution of the interplanetary dust SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,APPL RES CORP,GREENBELT,MD 20771. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 296 EP 300 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00037 ER PT S AU Mitchell, KJ Berriman, GB Kelsall, T Richardson, D Skard, JA Stemwedel, SW AF Mitchell, KJ Berriman, GB Kelsall, T Richardson, D Skard, JA Stemwedel, SW BE Dwek, E TI Infrared point source photometry with DIRBE: Instrument gain stabilization and variable star monitoring SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,GEN SCI CORP,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 301 EP 304 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00038 ER PT S AU Arendt, RG Freudenreich, HT Dwek, E AF Arendt, RG Freudenreich, HT Dwek, E BE Dwek, E TI Subtraction of galactic stellar emission from COBE/DIRBE observations SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,APPL RES CORP,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 305 EP 308 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00039 ER PT S AU Sodroski, TJ Arendt, RG Odegard, N Weiland, JL Dwek, E Hauser, MG Kelsall, T AF Sodroski, TJ Arendt, RG Odegard, N Weiland, JL Dwek, E Hauser, MG Kelsall, T BE Dwek, E TI A three-dimensional decomposition of the infrared emission from dust in the milky way SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,APPL RES CORP,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 309 EP 313 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00040 ER PT S AU Odenwald, S Newmark, J Smoot, G AF Odenwald, S Newmark, J Smoot, G BE Dwek, E TI DIRBE 12-240 micron survey for external galaxies SO UNVEILING THE COSMIC INFRARED BACKGROUND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT COBE Workshop on Unveiling the Cosmic Infrared Background CY APR 23-25, 1995 CL COLLEGE PK, MD SP NASA Cosmic Background Explorer COBE Project C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-508-9 J9 AIP CONF PROC PY 1996 IS 348 BP 318 EP 320 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BE91M UT WOS:A1996BE91M00042 ER PT B AU Wada, BK AF Wada, BK BE Inoue, K Shen, SIY Taya, M TI Precision actuators for space application SO US-JAPAN WORKSHOP ON SMART MATERIALS AND STRUCTURES LA English DT Proceedings Paper CT 1st US-Japan Workshop on Smart Materials and Structures CY DEC 03-04, 1995 CL UNIV WASHINGTON, SEATTLE, WA SP Natl Sci Fdn, Inst Mech & Mat, New Energy Dev Org, R&D Inst Met & Composites Future Ind, Mineral Met & Mat Soc (TMS), Univ Washington, Coll Engn HO UNIV WASHINGTON AB The paper presents a brief overview of the requirements and the development of actuators at the Jet Propulsion Laboratory (JPL) for space application. For precision space applications, the actuator materials at JPL are either piezoelectric, electrostrictive, magnetic, or magnetostrictive; generally the actuators sacrifices stroke for precision. The emphasis is on a recent development of a long stroke precision piezoelectric actuator that offers additional features such as compactness and redundancy. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wada, BK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-333-3 PY 1996 BP 181 EP 186 PG 4 WC Materials Science, Composites SC Materials Science GA BM47S UT WOS:000078856600021 ER PT B AU Cleghorn, TF Jaggi, S AF Cleghorn, TF Jaggi, S BE Juday, RD Park, SK TI Fractal dimension estimation in images: Applications and comparisons SO VISUAL INFORMATION PROCESSING V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing V CY APR 09, 1996 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE fractal; fractal dimension; chaos theory; image analysis C1 NASA,LYNDON B JOHNSON SPACE CTR,AUTOMAT ROBOT & SIMULAT DIV,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2134-0 J9 P SOC PHOTO-OPT INS PY 1996 VL 2753 BP 28 EP 37 DI 10.1117/12.235339 PG 10 WC Optics SC Optics GA BG12D UT WOS:A1996BG12D00004 ER PT S AU Interrante, V Fuchs, H Pizer, S AF Interrante, V Fuchs, H Pizer, S GP IEEE COMP SOC TI Illustrating transparent surfaces with curvature-directed strokes SO VISUALIZATION '96, PROCEEDINGS SE IEEE CONFERENCE ON VISUALIZATION LA English DT Proceedings Paper CT 7th Annual IEEE Conference on Visualization (Visualization 96) CY OCT 27-NOV 01, 1996 CL SAN FRANCISCO, CA SP IEEE Comp Soc Tech Comm Comp Graph, ACM SIGGRAPH AB Transparency can be a useful device for simultaneously depicting multiple superimposed layers of information in a single image. However, in computer-generated pictures - as in photographs and in directly viewed actual objects - it can often be difficult to adequately perceive the three-dimensional shape of a layered transparent surface or its relative depth distance from underlying structures. Inspired by artists' use of line to show shape, we have explored methods for automatically defining a distributed set of opaque surface markings that intend to portray the three-dimensional shape and relative depth of a smoothly curving layered transparent surface in an intuitively meaningful (and minimally occluding) way. This paper describes the perceptual motivation, artistic inspiration and practical implementation of an algorithm for ''texturing'' a transparent surface with uniformly distributed opaque short strokes, locally oriented in the direction of greatest normal curvature, and of length proportional to the magnitude of the surface curvature in the stroke direction. The driving application for this work is the visualization of layered surfaces in radiation therapy treatment planning data, and the technique is illustrated on transparent isointensity surfaces of radiation dose. RP Interrante, V (reprint author), NASA,LANGLEY RES CTR,ICASE,HAMPTON,VA 23665, USA. NR 0 TC 21 Z9 21 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 1070-2385 BN 0-89791-864-9 J9 IEEE VISUAL PY 1996 BP 211 EP + DI 10.1109/VISUAL.1996.568110 PG 5 WC Computer Science, Software Engineering SC Computer Science GA BG87S UT WOS:A1996BG87S00029 ER PT S AU Bryson, S Kenwright, D GeraldYamasaki, M AF Bryson, S Kenwright, D GeraldYamasaki, M GP IEEE COMP SOC TI FEL: The field encapsulation library SO VISUALIZATION '96, PROCEEDINGS SE IEEE CONFERENCE ON VISUALIZATION LA English DT Proceedings Paper CT 7th Annual IEEE Conference on Visualization (Visualization 96) CY OCT 27-NOV 01, 1996 CL SAN FRANCISCO, CA SP IEEE Comp Soc Tech Comm Comp Graph, ACM SIGGRAPH AB This paper describes the Field Encapsulation Library (FEL), which provides a grid-independent application programmer's interface to gridded three-dimensional field data. The C++ implementation of FEL is described, stressing the way in which the class hierarchy hides the underlying grid structure in a way that allows visualization algorithms to be written in a completely grid-independent manner: Appropriately defined coordinate classes play an important role in providing this grid independence. High-performance point location routines for data access are described and performance rimes are provided. RP Bryson, S (reprint author), NASA,AMES RES CTR,MRJ INC,MAIL STOP T27A-1,MOFFETT FIELD,CA 94035, USA. NR 0 TC 8 Z9 8 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 1070-2385 BN 0-89791-864-9 J9 IEEE VISUAL PY 1996 BP 241 EP 247 DI 10.1109/VISUAL.1996.568115 PG 3 WC Computer Science, Software Engineering SC Computer Science GA BG87S UT WOS:A1996BG87S00033 ER PT S AU Bryson, S Johan, S AF Bryson, S Johan, S GP IEEE COMP SOC TI Time management, simultaneity and time-critical computation in interactive unsteady visualization environments SO VISUALIZATION '96, PROCEEDINGS SE IEEE CONFERENCE ON VISUALIZATION LA English DT Proceedings Paper CT 7th Annual IEEE Conference on Visualization (Visualization 96) CY OCT 27-NOV 01, 1996 CL SAN FRANCISCO, CA SP IEEE Comp Soc Tech Comm Comp Graph, ACM SIGGRAPH AB This paper describes time management and time critical computing for a near-real-time interactive unsteady visualization environment. Subtle issues regarding the flow of time are described, formalized and addressed. The resulting system correctly reflects rime behavior while allowing the user to control the flow of time. The problem of time-critical computation is discussed, and a solution is presented. These time-critical algorithms provide control over the frame rate of a visualization system, allowing interactive exploration. RP Bryson, S (reprint author), NASA,AMES RES CTR,MRJ INC,MS T27A-1,MOFFETT FIELD,CA 94035, USA. NR 0 TC 16 Z9 16 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 1070-2385 BN 0-89791-864-9 J9 IEEE VISUAL PY 1996 BP 255 EP + DI 10.1109/VISUAL.1996.568117 PG 4 WC Computer Science, Software Engineering SC Computer Science GA BG87S UT WOS:A1996BG87S00035 ER PT S AU Garvin, JB AF Garvin, JB BE McGuire, WJ Jones, AP Neuberg, J TI Topographic characterization and monitoring of volcanoes via airborne laser altimetry SO VOLCANO INSTABILITY ON THE EARTH AND OTHER PLANETS SE GEOLOGICAL SOCIETY SPECIAL PUBLICATION LA English DT Proceedings Paper CT Conference on Volcano Instability on the Earth and Other Planets CY MAY, 1994 CL LONDON, ENGLAND SP Geol Soc, Volcan Studies Grp, Joint Assoc Geophys Geol & Royal Astron Soc C1 NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,GREENBELT,MD 20771. RI Jones, Adrian/D-4896-2013 OI Jones, Adrian/0000-0001-5137-5783 NR 0 TC 3 Z9 3 U1 0 U2 0 PU GEOLOGICAL SOC PUBLISHING HOUSE PI BATH PA UNIT 7, BRASSMILL ENTERPRISE CTR, BRASSMILL LANE, BATH, AVON, ENGLAND BA1 3JN SN 0305-8719 BN 1-897799-60-8 J9 GEOL SOC SP PY 1996 IS 110 BP 137 EP 152 PG 16 WC Geology; Geosciences, Multidisciplinary SC Geology GA BF94B UT WOS:A1996BF94B00011 ER PT J AU Hollenbeck, KJ Schmugge, TJ Hornberger, GM Wang, JR AF Hollenbeck, KJ Schmugge, TJ Hornberger, GM Wang, JR TI Identifying soil hydraulic heterogeneity by detection of relative change in passive microwave remote sensing observations SO WATER RESOURCES RESEARCH LA English DT Article ID UNSATURATED FLOW; MOISTURE AB The ability of passive microwave remote sensing (PMRS) to assess soil moisture has been amply demonstrated. Building on the expertise, this research is a first attempt at obtaining near-surface soil hydraulic characteristics from PMRS. We show that relative change in surface soil moisture can de determined accurately from PMRS measurements of brightness temperature, given the commonly observed linear relationship between the two variables. Relative, rather than absolute, change within a series of PMRS images, obtained during a period of drying, is also a very useful statistic for filtering out the drydown heterogeneity caused by spatial variability in initial wetness rather than soil heterogeneity. We develop a test of soil heterogeneity based on the detection of deviations of relative change from the average rate in a series of images by more than the instrument error. With the test the existence of soil heterogeneity for a pair of images showing a drydown during the 1992 Hydrologic Atmospheric Pilot Experiment (HAPEX-Sahel) experiment can be proven. Areas of relatively fast or slow drying can be mapped. These areas coincide with geomorphological features and soil-type patterns that are expected to show the observed moisture dynamics. The variogram of relative change in the HAPEX images differs from those of brightness temperature, corroborating the rejection of the soil homogeneity hypothesis. Furthermore, the variogram indicates the existence of an effective correlation length much larger than that commonly observed in ground-based soil surveys. These findings encourage the use of PMRS for assessing soil hydraulic characteristics that are valid at a scale appropriate for hydrometeorological models. C1 USDA,HYDROL LAB,BELTSVILLE,MD 20705. NASA,GODDARD SPACE FLIGHT CTR,MICROWAVE SENSORS BRANCH,GREENBELT,MD 20771. RP Hollenbeck, KJ (reprint author), UNIV VIRGINIA,DEPT ENVIRONM SCI,CLARK HALL,CHARLOTTESVILLE,VA 22903, USA. NR 27 TC 37 Z9 37 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JAN PY 1996 VL 32 IS 1 BP 139 EP 148 DI 10.1029/95WR02916 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TN961 UT WOS:A1996TN96100014 ER PT B AU Davis, L Mazed, M Keo, S Singletary, J Vang, T Forouhar, S AF Davis, L Mazed, M Keo, S Singletary, J Vang, T Forouhar, S BE Lome, LS TI InP-based ridge waveguide lasers for wavelength division multiplexing applications SO WAVELENGTH DIVISION MULTIPLEXING COMPONENTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelength Division Multiplexing Components CY JAN 29-31, 1996 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Adv Res Projects Agcy DE wavelength division multiplexing; ridge waveguide laser; buried heterostructure laser; semiconductor laser array; distributed feedback laser C1 CALTECH,JET PROP LAB,CTR SPACE MICROELECTR,PASADENA,CA 91109. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2064-6 J9 P SOC PHOTO-OPT INS PY 1996 VL 2690 BP 304 EP 312 DI 10.1117/12.238927 PG 9 WC Optics SC Optics GA BF60T UT WOS:A1996BF60T00032 ER PT B AU Chettri, S Ishiwaka, Y Kimura, H Nagano, I AF Chettri, S Ishiwaka, Y Kimura, H Nagano, I BE Szu, HH TI Harmonic wavelets, constant Q transforms and the cone kernel TFD SO WAVELET APPLICATIONS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Wavelet Applications III Conference CY APR 08-12, 1996 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE musical wavelets; constant Q transforms; bilinear time-frequency distributions; cone kernel tfd's; analysis of musical signals C1 NASA,GODDARD SPACE FLIGHT CTR,GST,GREENBELT,MD 20771. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2143-X J9 P SOC PHOTO-OPT INS PY 1996 VL 2762 BP 446 EP 451 DI 10.1117/12.236016 PG 6 WC Computer Science, Artificial Intelligence; Engineering, Biomedical; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Computer Science; Engineering; Remote Sensing; Optics GA BF34Y UT WOS:A1996BF34Y00044 ER PT B AU LeMoigne, J Cromp, RF AF LeMoigne, J Cromp, RF BE Szu, HH TI The use of wavelets for remote sensing image registration and fusion SO WAVELET APPLICATIONS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Wavelet Applications III Conference CY APR 08-12, 1996 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE wavelets; image registration; image fusion; remote sensing data analysis C1 NASA,GODDARD SPACE FLIGHT CTR,CODE 9035,GREENBELT,MD 20771. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2143-X J9 P SOC PHOTO-OPT INS PY 1996 VL 2762 BP 535 EP 544 DI 10.1117/12.236025 PG 10 WC Computer Science, Artificial Intelligence; Engineering, Biomedical; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Computer Science; Engineering; Remote Sensing; Optics GA BF34Y UT WOS:A1996BF34Y00052 ER PT B AU Hornstein, RS Hei, DJ CuretonSnead, IE AF Hornstein, RS Hei, DJ CuretonSnead, IE GP IEEE TI Fundamental reusables for enterprise deployment - A radical look at Customer Service SO WESCON - 96, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Wescon 96 Conference CY OCT 22-24, 1996 CL ANAHEIM, CA SP IEEE, Los Angeles Bay Area Council, IEEE, San Francisco Bay Area Council, ERA, So Calif Chapter, ERA, No Calif Chapter RP Hornstein, RS (reprint author), NASA,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3275-X PY 1996 BP 22 EP 27 DI 10.1109/WESCON.1996.553959 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BG78Y UT WOS:A1996BG78Y00005 ER PT B AU Garrett, HB Whittlesey, AC AF Garrett, HB Whittlesey, AC GP IEEE TI Spacecraft charging, an update SO WESCON - 96, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Wescon 96 Conference CY OCT 22-24, 1996 CL ANAHEIM, CA SP IEEE, Los Angeles Bay Area Council, IEEE, San Francisco Bay Area Council, ERA, So Calif Chapter, ERA, No Calif Chapter AB Nearly twenty years after the landmark SCATHA program, spacecraft charging and its associated plasma interactions continue to be major issues for Earth-orbiting spacecraft. Although typically thought of as a surface effect on geosynchronous spacecraft, internal charging and low-altitude phenomena are increasingly causing concern. Since the time of SCATHA, spacecraft charging investigation efforts were focused on surface effects and spacecraft design issues. Today a growing proportion of spacecraft anomalies are believed to be caused by internal charging effects (charging and ESD events inside the spacecraft Faraday cage). This review will, following a brief summary of the state of the art in surface charging, concentrate an the problems introduced by penetrating electrons (''internal charging'') and related processes (buried charge and deep dielectric charging) and on the issues tied to the dense, low altitude plasma environment and the auroral zone. Likewise, with the advent of tethered spacecraft and the deployment of the international Space Station (shortly), low altitude charging has taken on a new significance and urgency. RP Garrett, HB (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3275-X PY 1996 BP 260 EP 267 DI 10.1109/WESCON.1996.553998 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BG78Y UT WOS:A1996BG78Y00044 ER PT B AU Cornford, SL Man, KF AF Cornford, SL Man, KF GP IEEE TI Risk/Requirements Trade-off Guidelines for low cost satellite systems SO WESCON - 96, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Wescon 96 Conference CY OCT 22-24, 1996 CL ANAHEIM, CA SP IEEE, Los Angeles Bay Area Council, IEEE, San Francisco Bay Area Council, ERA, So Calif Chapter, ERA, No Calif Chapter AB The accelerating trend toward Faster, Better, Cheaper (FBC) missions places increasing emphasis on the trade-offs between requirements and risk to reduce cost and development times, while still improving quality and reliability. The Risk/Requirements Trade-off Guidelines discussed in this paper are part of an integrated approach tc,address the main issues by focusing on the sum of prevention, analysis, control or test (PACT) processes. This approach maps weighted risk (or failure modes) against detection or prevention options to provide a mechanism for performing risk/resource tradeoffs, The population of this matrix can be done a ''row at a time'' by examining the value added elf each requirement or PACT, in terms of risk reduction. This row by raw development is the principle focus of the guidelines described herein. Cost drivers in the performance of these specific areas are identified for potential trade-off studies. Parametric trade-offs that would be cost effective are indicated and effective substitutes for specific requirements are discussed. RP Cornford, SL (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3275-X PY 1996 BP 274 EP 279 DI 10.1109/WESCON.1996.554000 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BG78Y UT WOS:A1996BG78Y00046 ER PT B AU Harvey, DG Jones, SG AF Harvey, DG Jones, SG GP IEEE TI Implementation of the ISO 9001 quality standard at the Jet Propulsion Laboratory SO WESCON - 96, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Wescon 96 Conference CY OCT 22-24, 1996 CL ANAHEIM, CA SP IEEE, Los Angeles Bay Area Council, IEEE, San Francisco Bay Area Council, ERA, So Calif Chapter, ERA, No Calif Chapter RP Harvey, DG (reprint author), CALTECH,JET PROP LAB,QUAL MANAGEMENT SYST PROGRAM OFF,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3275-X PY 1996 BP 412 EP 417 DI 10.1109/WESCON.1996.554022 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BG78Y UT WOS:A1996BG78Y00068 ER PT B AU Hale, JP AF Hale, JP GP IEEE TI Applied virtual reality in aerospace SO WESCON - 96, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Wescon 96 Conference CY OCT 22-24, 1996 CL ANAHEIM, CA SP IEEE, Los Angeles Bay Area Council, IEEE, San Francisco Bay Area Council, ERA, So Calif Chapter, ERA, No Calif Chapter RP Hale, JP (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,CREW SYST TEAM EO66,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3275-X PY 1996 BP 547 EP 550 DI 10.1109/WESCON.1996.554573 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BG78Y UT WOS:A1996BG78Y00091 ER PT B AU Cornford, SL Gibbel, M AF Cornford, SL Gibbel, M GP IEEE TI Methodology for physics & engineering of reliable products SO WESCON - 96, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Wescon 96 Conference CY OCT 22-24, 1996 CL ANAHEIM, CA SP IEEE, Los Angeles Bay Area Council, IEEE, San Francisco Bay Area Council, ERA, So Calif Chapter, ERA, No Calif Chapter AB Physics of failurer approach have gained wide spread acceptance by most within the Electronic Reliability Community. These methodologies involve identifying root cause failure mechanisms, developing associated models, and utilizing these models to improve time to market, lower development and build costs and higher reliability. The methodology outlined herein sets forth a process, based on integration of both physics and engineering principles, for achieving the same goals. The proposed methodology is consistent with a ''pure'' physics of failure methodology, but it has the distinct advantage of not being ''dead-in-the-water'' if failure physics models do not exist. It also goes a long way to overcoming the age old axiom that ''typically the things that fail are not the things that were analyzed, evaluated, etc, but rather the things that were assumed to not to be a problem''. It outlines a methodology for integrating all available data, at various data quality levels, to make the best possible decisions. The key components are: 1) existing physics and engineering models, 2) utilizing a problem/failure reporting system and other data sources to identify ''tall poles'' and their root cause for current designs and process and 3) new technology evaluations based on failure physics assessments. RP Cornford, SL (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3275-X PY 1996 BP 618 EP 624 DI 10.1109/WESCON.1996.554597 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA BG78Y UT WOS:A1996BG78Y00101 ER PT J AU Kondo, Y AF Kondo, Y BE Niemela, V Morell, N TI Mass flow in and out of close binaries SO WORKSHOP ON COLLIDING WINDS IN BINARY STARS TO HONOR JORGE SAHADE SE REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, SERIE DE CONFERENCIAS LA English DT Proceedings Paper CT Workshop on Colliding Winds in Binary Stars, Celebrating the Prof Dr Jorge Sahades 80th Birthday CY NOV 21-24, 1995 CL UNIV NACL LA PLATA, FAC CIEN ASTRON & GEOFIS, LA PLATA, ARGENTINA SP Argentine Astron Assoc, Univ La Plata, Fac Cien Astron & Geofis, Consejo Nacl Investigac Cient & Tecn Republica Argentina, UNESCO, Org Estados Americanos HO UNIV NACL LA PLATA, FAC CIEN ASTRON & GEOFIS DE binaries, close; stars, mass loss AB Mass flow in interacting binary stars, including those with collapsed objects, is discussed in terms of both observational data and theoretical basis. The notion of wholly conservative mass flow arises from the so-called ''Roche lobe'' overflow model, in which the mass lost from one component is accreted by its companion star. This conjecture can be shown to be invalid when the restricted three-body problem is examined critically. Actual observations made in a number of binaries in several wavelengths, including the ultraviolet region, show complex gas dynamics, involving gas streams within and out of the binary, putative accretion disks in some systems, and accretion to the companion. RP Kondo, Y (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA PI MEXICO CITY PA APARTADO POSTAL 70-264, MEXICO CITY 04510, MEXICO SN 1405-2059 J9 REV MEX AST ASTR PY 1996 VL 5 BP 5 EP 8 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH25G UT WOS:A1996BH25G00002 ER PT S AU Corcoran, MF AF Corcoran, MF BE Niemela, V Morell, N TI X-ray emission from colliding wind binaries SO WORKSHOP ON COLLIDING WINDS IN BINARY STARS TO HONOR JORGE SAHADE SE REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, SERIE DE CONFERENCIAS LA English DT Proceedings Paper CT Workshop on Colliding Winds in Binary Stars, Celebrating the Prof Dr Jorge Sahades 80th Birthday CY NOV 21-24, 1995 CL UNIV NACL LA PLATA, FAC CIEN ASTRON & GEOFIS, LA PLATA, ARGENTINA SP Argentine Astron Assoc, Univ La Plata, Fac Cien Astron & Geofis, Consejo Nacl Investigac Cient & Tecn Republica Argentina, UNESCO, Org Estados Americanos HO UNIV NACL LA PLATA, FAC CIEN ASTRON & GEOFIS DE binaries, close; stars, early-type; stars, Wolf-Rayet; X-rays, stars AB I present new evidence of X-ray production by wind collisions in early-type binary systems by looking for phase-dependent changes in the observed X-ray emission. Newly derived X-ray lightcurves for 18 O-type binaries indicate that variability is far more common for O-type binaries than for single O stars. Four of the 18 systems studied show clear evidence of phase-dependent variability, suggesting that a large fraction of the X-ray emission is produced in a localized wind collision region. I examine 3 important WR + O systems, WR140, gamma(2) Velorum and V444 Cygni, and show that the observed X-ray variations are consistent with the predictions of modern colliding wind models. RP Corcoran, MF (reprint author), NASA,GODDARD SPACE FLIGHT CTR,LHEA,USRA,GREENBELT,MD 20771, USA. NR 0 TC 36 Z9 36 U1 0 U2 0 PU UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA PI MEXICO CITY PA APARTADO POSTAL 70-264, MEXICO CITY 04510, MEXICO SN 1405-2059 J9 REV MEX AST ASTR PY 1996 VL 5 BP 54 EP 60 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH25G UT WOS:A1996BH25G00010 ER PT J AU Keyes, DE Venkatakrishnan, V AF Keyes, DE Venkatakrishnan, V TI Newton-Krylov-Schwarz methods: Interfacing sparse linear solvers with nonlinear applications SO ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK LA English DT Article; Proceedings Paper CT 3rd International Congress on Industrial and Applied Mathematics (ICIAM 95) CY JUL 03-07, 1995 CL HAMBURG, GERMANY SP Gesell Angew Math & Mech ID EQUATIONS AB Parallel implicit solution methods are increasingly important in large-scale applications, since reliable lour-residual solutions to individual steady-state analyses are often needed repeatedly in multidisciplinary analysis and optimization. We review a class of linear implicit methods called Krylov-Schwarz and a class of nonlinear implicit methods called Newton-Krylov. Newton-Krylov methods are suited for problems in which it is unreasonable to compute or store a true Jacobian, given a strong enough preconditioner for the inner linear system that needs to be solved for each Newton correction. Schwarz-type domain decomposition preconditioning provides good data locality for parallel implementations over a range of granularities. Their composition forms a class of methods called Newton-Krylov-Schwarz with strong potential for parallel implicit solution, as illustrated on an aerodynamics application. C1 NASA,LANGLEY RES CTR,ICASE,HAMPTON,VA 23681. RP Keyes, DE (reprint author), OLD DOMINION UNIV,DEPT COMP SCI,NORFOLK,VA 23529, USA. NR 8 TC 7 Z9 7 U1 0 U2 0 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0044-2267 J9 Z ANGEW MATH MECH JI Z. Angew. Math. Mech. PY 1996 VL 76 SU 1 BP 147 EP 150 PG 4 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA VG254 UT WOS:A1996VG25400039 ER PT J AU Knoll, DA McHugh, PR Keyes, DE AF Knoll, DA McHugh, PR Keyes, DE TI Domain decomposition methods applied to a system of convection-diffusion-reaction equations SO ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK LA English DT Article; Proceedings Paper CT 3rd International Congress on Industrial and Applied Mathematics (ICIAM 95) CY JUL 03-07, 1995 CL HAMBURG, GERMANY SP Gesell Angew Math & Mech ID ITERATIVE SOLUTION; LINEAR-SYSTEMS; MATRIX AB Obtaining efficient and robust solutions to realistic fluid flow problems with chemical reactions is a challenging computational task. This is due to the potential wide disparity in lime and space scales and the severe nonlinearities. However, there is significant industrial application for such a capability in areas such as energy production, propulsion, and materials processing. These applications are often characterized by regions of low Mach number flow. This study investigates Newton-Krylov algorithms with domain-based preconditioning for the solution of these types of problems. Domain-based preconditioners may offer improvements in robustness and parallelism over more standard ILU type preconditioners. Results are presented comparing additive and multiplicative Schwarz preconditioners to more standard global ILU preconditioners on a low Mach number combustion problem. C1 NASA,LANGLEY RES CTR,ICASE,HAMPTON,VA 23681. OLD DOMINION UNIV,DEPT COMP SCI,NORFOLK,VA 23529. RP Knoll, DA (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0044-2267 J9 Z ANGEW MATH MECH JI Z. Angew. Math. Mech. PY 1996 VL 76 SU 1 BP 235 EP 238 PG 4 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA VG254 UT WOS:A1996VG25400061 ER PT J AU Melvin, RG Young, DP Keyes, DE Ashcraft, CC Bieterman, MB Hilmes, CL Huffman, WP Johnson, FT AF Melvin, RG Young, DP Keyes, DE Ashcraft, CC Bieterman, MB Hilmes, CL Huffman, WP Johnson, FT TI A two-level acceleration scheme applied to full potential flow computations SO ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK LA English DT Article; Proceedings Paper CT 3rd International Congress on Industrial and Applied Mathematics (ICIAM 95) CY JUL 03-07, 1995 CL HAMBURG, GERMANY SP Gesell Angew Math & Mech AB The TRANAIR aerodynamics code is used as a testbed for developing advanced iterative methods that lend themselves to parallel or distributed computing. In the case of aerodynamics design optimization, a significant part of the computational cost is in the solution of large sparse nonsymmetric linear systems. We have implemented a two-level method for solving such linear systems and present preliminary computational results for problems in two space dimensions. We observe a lime-space trade-off mediated by parameters that govern the amount of fill-in in incomplete factorizations on each level. In both subsonic and transonic flow regimes, parameter choices exist that lead to substantial improvements in runtime for comparable memory requirements, relative to a single grid method. C1 OLD DOMINION UNIV,DEPT COMP SCI,NORFOLK,VA 23529. NASA,LANGLEY RES CTR,ICASE,HAMPTON,VA 23681. RP Melvin, RG (reprint author), BOEING CO,M-S 7L-2L,POB 3707,SEATTLE,WA 98124, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0044-2267 J9 Z ANGEW MATH MECH JI Z. Angew. Math. Mech. PY 1996 VL 76 SU 1 BP 243 EP 246 PG 4 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA VG254 UT WOS:A1996VG25400063 ER PT J AU Sterling, T Merkey, P Savarese, D AF Sterling, T Merkey, P Savarese, D TI HPC architecture requirements for Earth and space science applications SO ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK LA English DT Article; Proceedings Paper CT 3rd International Congress on Industrial and Applied Mathematics / Annual Conference of the Gesellschaft-fur-Angewandte-Mathematik-und-Mechanik e V (ICIAM/GAMM 95) - Applied Analysis CY JUL 03-07, 1995 CL HAMBURG, GERMANY SP Gesell Angew Math & Mech AB Scalable high performance computer architecture brings substantial processing, memory, and communications resources to large scientific and engineering applications while leveraging industrial investment and rapid growth in VLSI microprocessor technology. These processor architectures, while approaching supercomputer performance, were developed to support the workstation market and incorporate policies consistent with the needs of that user community. Large parallel computers differ from workstations in that they exhibit high diameter and experience extremes in memory access latency. These architectures employ sophisticated cache structures to minimize average latency and achieve high apparent memory bandwidth. Unfortunately, many large scientific codes do not exhibit memory access patterns with the necessary locality of reference on which effective use of cache mechanisms relies. This presentation examines the memory access patterns of applications from the Earth and space sciences community and considers their implications for cache based architecture. RP Sterling, T (reprint author), NASA,GODDARD SPACE FLIGHT CTR,USRA CESDIS,CODE 9305,GREENBELT,MD 20771, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0044-2267 J9 Z ANGEW MATH MECH JI Z. Angew. Math. Mech. PY 1996 VL 76 SU 2 BP 445 EP 448 PG 4 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA VK359 UT WOS:A1996VK35900113 ER PT J AU Sweby, PK Yee, HC AF Sweby, PK Yee, HC TI On the dynamics of some discretisations of convection-diffusion equations SO ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK LA English DT Article; Proceedings Paper CT 3rd International Congress on Industrial and Applied Mathematics (ICIAM 95) CY JUL 03-07, 1995 CL HAMBURG, GERMANY SP Gesell Angew Math & Mech AB Numerical discretisations of differential equations which model physical processes can possess dynamics guile different from that of dhe equations themselves (see [3] and references therein). Recently the emphasis of study has been on the the dynamics of numerical discretisations for Ordinary Differential Equations (ODEs). For Partial Differential Equations (PDEs) using a method of lines approach the situation is more complex. First, dhe spatial discretisation may introduce dynamics not present in the original equations; second, the solution of the resulting system of ODEs is open to the modified dynamics of the ODE solver used. These two effects may interact in a complex manner. In this short paper we summarise some results of our recent work on the dynamics of discretisations of convection-diffusion equations using Total Variation Diminishing (TVD) schemes and adaptive grid techniques. Results using classical spatial differencing (non-TVD) are presented in [1]. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP Sweby, PK (reprint author), UNIV READING,DEPT MATH,WHITEKNIGHTS PO BOX 220,READING RG6 6AF,BERKS,ENGLAND. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0044-2267 J9 Z ANGEW MATH MECH JI Z. Angew. Math. Mech. PY 1996 VL 76 SU 1 BP 553 EP 554 PG 2 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA VG254 UT WOS:A1996VG25400196 ER PT S AU Wheeler, RM Mackowiak, CL Sager, JC Knott, WM Berry, WL AF Wheeler, RM Mackowiak, CL Sager, JC Knott, WM Berry, WL BE MacElroy, RD Kreuzberg, K Nielsen, S Tibbits, TW TI Proximate composition of celss crops grown in NASA's biomass production chamber SO NATURAL AND ARTIFICIAL ECOSYSTEMS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT F4.1, F4.2, F4.5, F4.7, F4.8 and F4.10 Meetings of COSPAR Scientific Commission F on Natural and Artificial Ecosystems, at the 30th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP COSPAR ID WHEAT AB Edible biomass from four crops of wheat (Triticum aestivum L.), four crops of lettuce (Lactuca sativa L.), four crops of potato (Solanum tuberosum L.), and three crops of soybean (Glycine max (L.) Merr.) grown in NASA's CELSS Biomass Production Chamber were analyzed for proximate composition. All plants were grown using recirculating nutrient (hydroponic) film culture with pH and electrical conductivity automatically controlled. Temperature and humidity were controlled to near optimal levels for each species and atmospheric carbon dioxide partial pressures were maintatined near 100 Pa during the light cycles. Soybean seed contained the highest percentage of protein and fat, potato tubers and wheat seed contained the highest levels of carbohydrate, and lettuce leaves contained the highest level of ash. Analyses showed values close to data published for field-grown plants with several exceptions: In comparison with field-grown plants, wheat seed had higher protein levels; soybean seed had higher ash and crude fiber levels; and potato tubers and lettuce leaves had higher protein and ash levels. The higher ash and protein levels may have been a result of the continuous supply of nutrients (e.g., potassium and nitrogen) to the plants by the recirculating hydroponic culture. C1 NASA, BIONET CORP, KENNEDY SPACE CTR, FL 32899 USA. RP Wheeler, RM (reprint author), NASA, BIOL RES & LIFE SUPPORT OFF, MAIL CODE MD-RES, KENNEDY SPACE CTR, FL 32899 USA. NR 14 TC 15 Z9 21 U1 1 U2 4 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042668-9 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 4/5 BP 43 EP 47 DI 10.1016/0273-1177(95)00860-H PG 5 WC Engineering, Aerospace; Agronomy; Ecology; Food Science & Technology; Horticulture; Nutrition & Dietetics SC Engineering; Agriculture; Environmental Sciences & Ecology; Food Science & Technology; Nutrition & Dietetics GA BE47C UT WOS:A1995BE47C00004 PM 11538813 ER PT S AU McKeehen, JD Mitchell, CA Wheeler, RM Bugbee, B Nielsen, SS AF McKeehen, JD Mitchell, CA Wheeler, RM Bugbee, B Nielsen, SS BE MacElroy, RD Kreuzberg, K Nielsen, S Tibbits, TW TI Excess nutrients in hydroponic solutions alter nutrient content of rice, wheat, and potato SO NATURAL AND ARTIFICIAL ECOSYSTEMS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT F4.1, F4.2, F4.5, F4.7, F4.8 and F4.10 Meetings of COSPAR Scientific Commission F on Natural and Artificial Ecosystems, at the 30th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP COSPAR ID NITRATE; NITRITE; GROWTH AB Environment has significant effects on the nutrient content of field-grown crop plants. Little is known, however, about compositional changes caused by controlled environments in which plants receive only artificial radiation and soilless, hydroponic culture. This knowledge is essential for developing a safe, nutritious diet in a Controlled Ecological Life-Support System (CELSS). Three crops that are candidates for inclusion in a CELSS (rice, wheat, and white potato) were grown both in the field and in controlled environments where the hydroponic nutrient solution, photosynthetic photon flux (PPF), and CO2 level were manipulated to achieve rapid growth rates. Plants were harvested at maturity, separated into discrete parts, and dried prior to analysis. Plant materials were analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate, minerals, and amino-acid composition. The effect of environment on nutrient content varied by crop and plant part. Total N and nonprotein N (NPN) contents of plant biomass generally increased under controlled-environment conditions compared to field conditions, especially for leafy plant parts and roots. Nitrate levels were increased in hydroponically-grown vegetative tissues, but nitrate was excluded from grains and tubers. Mineral content changes in plant tissue included increased phosphorus and decreased levels of certain micronutrient elements under controlled-environment conditions. These findings suggest that cultivar selection, genetic manipulation, and environmental control could be important to obtain highly nutritious biomass in a CELSS. C1 NASA, BIOL RES & LIFE SUPPORT OFF, KENNEDY SPACE CTR, FL 32899 USA. UTAH STATE UNIV, DEPT PLANTS SOILS & BIOMETEOROL, LOGAN, UT 84322 USA. RP McKeehen, JD (reprint author), PURDUE UNIV, NASA, SPECIALIZED CTR RES & TRAINING, W LAFAYETTE, IN 47907 USA. RI bugbee, bruce/I-5008-2012 NR 30 TC 13 Z9 13 U1 0 U2 12 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042668-9 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 4/5 BP 73 EP 83 DI 10.1016/0273-1177(95)00863-A PG 11 WC Engineering, Aerospace; Agronomy; Ecology; Food Science & Technology; Horticulture; Nutrition & Dietetics SC Engineering; Agriculture; Environmental Sciences & Ecology; Food Science & Technology; Nutrition & Dietetics GA BE47C UT WOS:A1995BE47C00007 PM 11538817 ER PT S AU McKeehen, JD Smart, DJ Mackowiak, CL Wheeler, RM Nielsen, SS AF McKeehen, JD Smart, DJ Mackowiak, CL Wheeler, RM Nielsen, SS BE MacElroy, RD Kreuzberg, K Nielsen, S Tibbits, TW TI Effect of CO2 levels on nutrient content of lettuce and radish SO NATURAL AND ARTIFICIAL ECOSYSTEMS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT F4.1, F4.2, F4.5, F4.7, F4.8 and F4.10 Meetings of COSPAR Scientific Commission F on Natural and Artificial Ecosystems, at the 30th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP COSPAR ID NITRATE; CARBOHYDRATE; NITRITE; GROWTH AB Atmospheric carbon-dioxide enrichment is known to affect the yield of lettuce and radish grown in controlled environments, but little is known about CO2 enrichment effects on the chemical composition of lettuce and radish. These crops are useful model systems for a Controlled Ecological Life-Support System (CELSS), largely because of their relatively short production cycles. Lettuce (Lactuca sativa L.) cultivar 'Waldmann's Green' and radish (Raphanus sativus L.) cultivar 'Giant White Globe' were grown both in the field and in controlled environments, where hydroponic nutrient solution, light, and temperature were regulated, and where CO2 levels were controlled at 400, 1000, 5000, or 10,000 ppm. Plants were harvested at maturity, dried, and analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate N, free sugars, starch, total dietary fiber, and minerals. Total N, protein N, nonprotein N (NPN), and nitrate N generally increased for radish roots and lettuce leaves when grown under growth chamber conditions compared to field conditions. The nitrate-N level of lettuce leaves, as a percentage of total NPN, decreased with increasing levels of CO2 enrichment. The ash content of radish roots and of radish and lettuce leaves decreased with increasing levels of CO2 enrichment. The levels of certain minerals differed between field- and chamber-grown materials, including changes in the calcium (Ca) and phosphorus (P) contents of radish roots and lettuce leaves, resulting in reduced Ca/P ratio for chamber-grown materials. The free-sugar contents were similar between the field and chamber-grown lettuce leaves, but total dietary fiber content was much higher in the field-grown plant material. The starch content of growth-chamber lettuce increased with CO2 level. C1 NASA, BIOL RES & LIFE SUPPORT OFF, KENNEDY SPACE CTR, FL 32899 USA. RP McKeehen, JD (reprint author), PURDUE UNIV, NASA, SPECIALIZED CTR RES & TRAINING, W LAFAYETTE, IN 47907 USA. NR 28 TC 14 Z9 15 U1 2 U2 20 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042668-9 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 4/5 BP 85 EP 92 DI 10.1016/0273-1177(95)00864-B PG 8 WC Engineering, Aerospace; Agronomy; Ecology; Food Science & Technology; Horticulture; Nutrition & Dietetics SC Engineering; Agriculture; Environmental Sciences & Ecology; Food Science & Technology; Nutrition & Dietetics GA BE47C UT WOS:A1995BE47C00008 PM 11538818 ER PT S AU Johnson, CF Dreschel, TW Brown, CS Wheeler, RM AF Johnson, CF Dreschel, TW Brown, CS Wheeler, RM BE MacElroy, RD Kreuzberg, K Nielsen, S Tibbits, TW TI Optimization of moisture content for wheat seedling germination in a cellulose acetate medium for a space flight experiment SO NATURAL AND ARTIFICIAL ECOSYSTEMS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT F4.1, F4.2, F4.5, F4.7, F4.8 and F4.10 Meetings of COSPAR Scientific Commission F on Natural and Artificial Ecosystems, at the 30th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP COSPAR AB The Porous Tube Plant Nutrient Delivery System (PTPNDS), a hydrophilic, microporous ceramic tube hydroponic system designed for microgravity, will be tested in a middeck locker of the Space Shuttle. The flight experiment will focus on hardware operation and assess its ability to support seed germination and early seedling growth in microgravity. The water controlling system of the PTPNDS hardware has been successfully tested during the parabolic flight of the KC-135. One challenge to the development of the space flight experiment was to devise a method of holding seeds to the cylindrical porous tube. The seed-holder must provide water and air to the seed, absorb water from the porous tube, withstand sterilization, provide a clear path for shoots and roots to emerge, and be composed of flight qualified materials. In preparation for the flight experiment, a wheat seed-holder has been designed that utilizes a cellulose acetate plug to facilitate imbibition and to hold the wheat seeds in contact with the porous tube in the correct orientation during the vibration of launch and the microgravity environment of orbit. Germination and growth studies with wheat at a range of temperatures showed that optimal moisture was 78% (by weight) in the cellulose acetate seed holders. These and other design considerations are discussed. C1 NASA, KENNEDY SPACE CTR, FL 32899 USA. RP Johnson, CF (reprint author), DYNAMAC CORP, CODE DYN-3, KENNEDY SPACE CTR, FL 32899 USA. OI Dreschel, Thomas/0000-0003-2211-5733 NR 10 TC 2 Z9 2 U1 1 U2 3 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042668-9 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 4/5 BP 239 EP 242 DI 10.1016/0273-1177(95)00883-G PG 4 WC Engineering, Aerospace; Agronomy; Ecology; Food Science & Technology; Horticulture; Nutrition & Dietetics SC Engineering; Agriculture; Environmental Sciences & Ecology; Food Science & Technology; Nutrition & Dietetics GA BE47C UT WOS:A1995BE47C00027 PM 11538804 ER PT S AU DURANTE, M GROSSI, GF YANG, TC AF DURANTE, M GROSSI, GF YANG, TC BE Kraft, G Carr, KE Goodwin, EH Ting, KC Finn, CK Tsai, KC Volk, T Henninger, DL Mitchell, CA MacElroy, RD Stabekis, P TI RADIATION-INDUCED CHROMOSOMAL INSTABILITY IN HUMAN MAMMARY EPITHELIAL-CELLS SO PHYSICAL, CHEMICAL, BIOCHEMICAL AND BIOLOGICAL TECHNIQUES AND PROCESSES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT F2.2, F2.3, F2.5, F4.3, F4.4, F4.9, F4.10 Meetings of COSPAR Scientific Commission F, at the 13th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP Comm Space Res ID DELAYED REPRODUCTIVE DEATH; C3H 10T1/2 CELLS; GENOMIC INSTABILITY; ALPHA-PARTICLES; GAMMA-RAYS; TRANSFORMATION; IRRADIATION; PROGRESSION; FIBROBLASTS; MUTATIONS AB Karyotypes of human cells surviving X- and alpha-irradiation have been studied. Human mammary epithelial cells of the immortal, non-tumorigenic cell line H184B5 F5-1 M/10 were irradiated and surviving clones isolated and expanded in culture. Cytogenetic analysis was performed using dedicated software with an image analyzer. We have found that both high- and low-LET radiation induced chromosomal instability in long-term cultures, but with different characteristics. Complex chromosomal rearrangements were observed after X-rays, while chromosome loss predominated after alpha-particles. Deletions were observed in both cases. In clones derived from cells exposed to alpha-particles, some cells showed extensive chromosome breaking and double minutes. Genomic instability was correlated to delayed reproductive death and neoplastic transformation. These results indicate that chromosomal instability is a radiation-quality-dependent effect which could determine late genetic effects, and should therefore be carefully considered in the evaluation of risk for space missions. C1 NASA, LYNDON B JOHNSON SPACE CTR, HOUSTON, TX 77058 USA. RP DURANTE, M (reprint author), UNIV NAPLES FEDERICO II, DIPARTIMENTO SCI FISICHE, MOSTRA OLTREMARE PAD 20, I-80125 NAPLES, ITALY. RI Durante, Marco/K-1315-2014; OI Durante, Marco/0000-0002-4615-553X NR 23 TC 33 Z9 33 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042664-6 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 1/2 BP 99 EP 108 DI 10.1016/0273-1177(95)00796-H PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Chemistry, Multidisciplinary SC Engineering; Astronomy & Astrophysics; Chemistry GA BE07T UT WOS:A1995BE07T00013 PM 11538994 ER PT S AU ERICKSON, JD ECKELKAMP, RE BARTA, DJ DRAGG, J AF ERICKSON, JD ECKELKAMP, RE BARTA, DJ DRAGG, J BE Kraft, G Carr, KE Goodwin, EH Ting, KC Finn, CK Tsai, KC Volk, T Henninger, DL Mitchell, CA MacElroy, RD Stabekis, P TI MISSION SIMULATION AS AN APPROACH TO DEVELOP REQUIREMENTS FOR AUTOMATION IN ADVANCED LIFE-SUPPORT-SYSTEMS SO PHYSICAL, CHEMICAL, BIOCHEMICAL AND BIOLOGICAL TECHNIQUES AND PROCESSES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT F2.2, F2.3, F2.5, F4.3, F4.4, F4.9, F4.10 Meetings of COSPAR Scientific Commission F, at the 13th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP Comm Space Res AB This paper examines mission simulation as an approach to develop requirements for automation and robotics for Advanced Life Support Systems (ALSS). The focus is on requirements and applications for command and control, control and monitoring, situation assessment and response, diagnosis and recovery, adaptive planning and scheduling, and other automation applications in addition to mechanized equipment and robotics applications to reduce the excessive human labor requirements to operate and maintain an ALSS. Based on principles of systems engineering, an approach is proposed to assess requirements for automation and robotics using mission simulation tools. First, the story of a simulated mission is defined in terms of processes with attendant types of resources needed, including options for use of automation and robotic systems. Next, systems dynamics models are used in simulation to reveal the implications for selected resource allocation schemes in terms of resources required to complete operational tasks. The simulations not only help establish ALSS design criteria, but also may offer guidance to ALSS research efforts by identifying gaps in knowledge about procedures and/or biophysical processes. Simulations of a planned one-year mission with 4 crewmembers in a Human Rated Test Facility are presented as an approach to evaluation of mission feasibility and definition of automation and robotics requirements. C1 LOCKHEED ENGN & SCI CO, HOUSTON, TX 77058 USA. RP ERICKSON, JD (reprint author), NASA, LYNDON B JOHNSON SPACE CTR, HOUSTON, TX 77058 USA. NR 15 TC 0 Z9 0 U1 1 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042664-6 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 1/2 BP 191 EP 196 DI 10.1016/0273-1177(95)00808-R PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Chemistry, Multidisciplinary SC Engineering; Astronomy & Astrophysics; Chemistry GA BE07T UT WOS:A1995BE07T00025 PM 11538963 ER PT S AU TROTMAN, AA ALMAZAN, AM ALEXANDER, AD LORETAN, PA ZHOU, X LU, JY AF TROTMAN, AA ALMAZAN, AM ALEXANDER, AD LORETAN, PA ZHOU, X LU, JY BE Kraft, G Carr, KE Goodwin, EH Ting, KC Finn, CK Tsai, KC Volk, T Henninger, DL Mitchell, CA MacElroy, RD Stabekis, P TI BIOLOGICAL DEGRADATION AND COMPOSITION OF INEDIBLE SWEET-POTATO BIOMASS SO PHYSICAL, CHEMICAL, BIOCHEMICAL AND BIOLOGICAL TECHNIQUES AND PROCESSES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT F2.2, F2.3, F2.5, F4.3, F4.4, F4.9, F4.10 Meetings of COSPAR Scientific Commission F, at the 13th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP Comm Space Res AB Many challenges are presented by biological degradation in a bioregenerative Controlled Ecological Life Support System (CELSS) as envisioned by the U.S. National Aeronautics and Space Administration (NASA). In the studies conducted with biodegradative microorganism indigenous to sweetpotato fields, it was determined that a particle size of 75 microns and incubation temperature of 30 degrees C were optimal for degradation The composition of the inedible biomass and characterization of plant nutrient solution indicated the presence of potential energy sources to drive microbial transformations of plant waste. Selected indigenous soil isolates with ligno-cellulolytic or sufate-reducing ability were: utilized in biological studies and demonstrated diversity in ability to reduce sulfate in solution and to utilize alternative carbon sources: a lignin analog-4-hydroxy, 3-methoxy cinnamic acid, cellulose, arabinose, glucose, sucrose, mannitol, galactose, ascorbic acid. RP TROTMAN, AA (reprint author), TUSKEGEE UNIV, NASA, CTR CELSS, TUSKEGEE, AL 36088 USA. FU CSAP SAMHSA HHS [ALX-SP-1] NR 11 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042664-6 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 1/2 BP 267 EP 279 DI 10.1016/0273-1177(95)00816-W PG 13 WC Engineering, Aerospace; Astronomy & Astrophysics; Chemistry, Multidisciplinary SC Engineering; Astronomy & Astrophysics; Chemistry GA BE07T UT WOS:A1995BE07T00033 PM 11538971 ER PT S AU Spicer, DS Zalesak, ST Lohner, R Curtis, S AF Spicer, DS Zalesak, ST Lohner, R Curtis, S BE Buchner, J TI Simulation of the magnetosphere with a new three dimensional MHD code and adaptive mesh refinement: Preliminary results SO THREE-DIMENSIONAL MAGNETOSPHERE SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D3 1 Symposium of COSPAR Scientific Commission D on the 3-Dimensional Magnetosphere, at the 30th COSPAR Scientific Assembly CY JUL 11-12, 1994 CL HAMBURG, GERMANY SP Comm Space Res, Int Assoc Geomagnetism & Aeron, Int Union Radio Sci, Inst Space & Astronaut Sci, Deut Agentur Fuer Raumfahrt Angelegenheiten ID INTERPLANETARY MAGNETIC-FIELD; HYBRID-DRIFT INSTABILITY; MAGNETOTAIL RECONNECTION; EARTHS MAGNETOSPHERE; SOLAR-WIND; GLOBAL SIMULATION; COMETARY PLASMAS; SOUTHWARD; COMPUTER; RESISTIVITY AB We present the first results from a new unstructured mesh three dimensional finite element MHD code which uses dynamic solution-adaptive mesh refinement in a manner similar to our two dimensional finite element MHD code /31/. The problem being considered here is the interaction of the solar wind with the earth's magnetosphere, using a three-dimensional Cartesian approximation. Our results strongly indicate that such adaptive mesh techniques have the ability to resolve structures in the three dimensional MHD flow field that would otherwise be possible only with orders of magnitude greater cost and that are most likely beyond the capability of present supercomputers. C1 GEORGE MASON UNIV, INST COMPUTAT SCI & INFORMAT, FAIRFAX, VA 22030 USA. NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, GREENBELT, MD 20771 USA. RP Spicer, DS (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CTR COMPUTAT SCI, GREENBELT, MD 20771 USA. NR 43 TC 6 Z9 6 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-042674-3 J9 ADV SPACE RES-SERIES PY 1996 VL 18 IS 8 BP 253 EP 262 DI 10.1016/0273-1177(95)00990-6 PG 10 WC Engineering, Aerospace; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Meteorology & Atmospheric Sciences; Remote Sensing GA BE73F UT WOS:A1995BE73F00038 ER PT J AU Thummel, HT Partridge, H Huo, WM AF Thummel, HT Partridge, H Huo, WM TI The theoretical transition probabilities between the B (3)Pi(g) and the A (3)Sigma(+)(u), W (3)Delta(u), B' (3)Sigma(-)(u) states of N-2 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID INFRARED-EMISSION SPECTRUM; RESOLUTION FOURIER SPECTROMETRY; EXTENSIVE ANALYSIS; BASIS-SETS; N2; N-14(2); SYSTEM AB The electronic transition moment functions between the B-3 Pi(g) state and the A (3) Sigma(u)(+), W-3 Delta(u), B'(3) Sigma(u)(-)A3 Sigma u+, W3 Delta u, B'3 Sigma u- states of N-2 are studied using the internally contracted multireference configuration interaction method based upon complete active space SCF reference wavefunctions. The dependence of the moments on both the one and n-particle basis sets has been investigated in detail. The calculated radiative lifetimes for the vibrational levels of the B-3 Pi(g) state are in excellent agreement with the most recent data published for nu' = 5 to 12, measured by laser induced fluorescence, and for nu' = 0, measured by electron impact induced fluorescence. RP Thummel, HT (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 25 TC 3 Z9 3 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD DEC 29 PY 1995 VL 247 IS 4-6 BP 366 EP 372 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TN291 UT WOS:A1995TN29100009 ER PT J AU Coleman, GN Kim, J Moser, RD AF Coleman, GN Kim, J Moser, RD TI A numerical study of turbulent supersonic isothermal-wall channel flow SO JOURNAL OF FLUID MECHANICS LA English DT Article ID BOUNDARY-LAYER; MIXING LAYERS AB A study of compressible supersonic turbulent flow in a plane channel with isothermal walls has been performed using direct numerical simulation. Mach numbers, based on the bulk velocity and sound speed at the walls, of 1.5 and 3 are considered; Reynolds numbers, defined in terms of the centreline velocity and channel half-width, are of the order of 3000. Because of the relatively low Reynolds number, all of the relevant scales of motion can be captured, and no subgrid-scale or turbulence model is needed. The isothermal boundary conditions give rise to a flow that is strongly influenced by wall-normal gradients of mean density and temperature. These gradients are found to cause an enhanced streamwise coherence of the near-wall streaks, but not to seriously invalidate Morkovin's hypothesis: the magnitude of fluctuations of total temperature and especially pressure are much less than their mean values, and consequently the dominant compressibility effect is that due to mean property variations. The Van Driest transformation is found to be very successful at both Mach numbers, and when properly scaled, statistics are found to agree well with data from incompressible channel flow results. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP Coleman, GN (reprint author), UNIV CALIF LOS ANGELES,DEPT MECH AEROSP & NUCL ENGN,48-121 ENGR IV,BOX 951597,LOS ANGELES,CA 90095, USA. OI Kim, John/0000-0002-6369-9264 NR 36 TC 152 Z9 156 U1 0 U2 13 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD DEC 25 PY 1995 VL 305 BP 159 EP 183 DI 10.1017/S0022112095004587 PG 25 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA TR011 UT WOS:A1995TR01100008 ER PT J AU Bills, BG Lemoine, FG AF Bills, BG Lemoine, FG TI Gravitational and topographic isotropy of the Earth, Moon, Mars, and Venus SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID HARMONIC-ANALYSIS; TERRESTRIAL PLANETS; GEOID ANOMALIES; GRAVITY-FIELD; MODEL; SPECTRA; PLATE AB The internal structures and surface shapes of the terrestrial planets are expected to be dominantly isotropic. We attempt to test this hypothesis by developing a criterion for recognizing statistical isotropy of spherical scalar fields and applying that test to the nonhydrostatic components of the gravitational and topographic fields of the Earth, Moon, Mars, and Venus. The criterion for topographic or geoidal surfaces is that the directional variance should be independent of azimuth. That is, the mean square east-west slopes should be equal to the mean square north-south slopes. All four planets generally pass the criteria, with a few minor exceptions. Most of the exceptions are likely to be artifacts of the current generation of planetary gravity and topography models rather than real features of the planets. Of the several broad-band departures from isotropy which we found, the only one likely to be real is the tendency for the Earth's gravity and topography to have only 80% as much variance in a north-south direction as in an east-west direction. C1 JOHNS HOPKINS UNIV,DEPT EARTH & PLANETARY SCI,BALTIMORE,MD 21218. NASA,GODDARD SPACE FLIGHT CTR,SPACE GEODESY BRANCH,GREENBELT,MD 20771. RP Bills, BG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,CODE 921,GREENBELT,MD 20771, USA. RI Bills, Bruce/C-1156-2008; Lemoine, Frank/D-1215-2013 NR 51 TC 16 Z9 16 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 25 PY 1995 VL 100 IS E12 BP 26275 EP 26295 DI 10.1029/95JE02982 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP057 UT WOS:A1995TP05700001 ER PT J AU Bills, BG AF Bills, BG TI Discrepant estimates of moments of inertia of the Moon SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article AB The moments of inertia of the Moon can be computed using various subsets of the degree two harmonics of the gravity field and the librational parameters. Recent estimates of these parameters allow four different solutions for the three principal moments of inertia. The solutions disagree by about 15 times the formal errors in the solutions. A possible resolution of these discrepancies involves nonrigid librational motion, either in the form of an elastic toroidal strain or with a fluid core which is only partially coupled to the rigid mantle. For this explanation to be viable, it must involve preferential strain in association with the longitudinal librations. Both gravitational and viscous coupling between a fluid core and a solid mantle are expected to have that behavior. C1 JOHNS HOPKINS UNIV,DEPT EARTH & PLANETARY SCI,BALTIMORE,MD 21218. RP Bills, BG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,CODE 921,GREENBELT,MD 20771, USA. RI Bills, Bruce/C-1156-2008 NR 24 TC 13 Z9 13 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 25 PY 1995 VL 100 IS E12 BP 26297 EP 26303 DI 10.1029/95JE03100 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP057 UT WOS:A1995TP05700002 ER PT J AU Bills, BG Rubincam, DP AF Bills, BG Rubincam, DP TI Constraints on density models from radial moments: Applications to Earth, Moon, and Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID HARMONIC-ANALYSIS; GRAVITY MODEL; INERTIA; TERRESTRIAL; TOPOGRAPHY; SATELLITES; TRACKING; VENUS AB Few objective constraints exist on radial density variations in planetary interiors. Even if the mean density and mean moment of inertia were known with perfect accuracy, they would only provide integral constraints on the density models. However, among the family of monotonic radial density models with a given mean density and mean moment of inertia, the simple two-layer piecewise constant models have useful extremal properties. The model has only three parameters, an inner density, an outer density, and a transition radius. Once the radial moment constraints are applied, there is only one remaining degree of freedom. If the outer region density is somehow specified, then the inner region density of the two-layer model provides a firm lower bound on central density of monotonic models. Likewise, if an upper bound on central density call be provided, then the two-layer model provides a lower bound on outer region density. An envelope of acceptable density models can be generated by scanning the transition depth from the center to the surface. Any monotonic model with specified mean density and mean inertial moment must lie within that envelope. Resulting extremal density envelopes for the Earth, Moon, and Mars are compared to published radial density profiles. For the Moon, the moment constraints are quite restrictive. For the Earth, which is more centrally condensed, the allowed envelope of density profiles is rather broad. Mars is an intermediate case. Present geodetic and astrometric observations only constrain the Martian mean moment of inertia to lie somewhere in the range 0.325 less than or equal to I/MR(2) < 0.365. However, our analysis shows that any value within that range can be accommodated without invoking geochemically implausible density minima or maxima. C1 JOHNS HOPKINS UNIV,BALTIMORE,MD. RP Bills, BG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,CODE 921,GREENBELT,MD 20771, USA. RI Bills, Bruce/C-1156-2008; Rubincam, David/D-2918-2012 NR 49 TC 23 Z9 23 U1 3 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 25 PY 1995 VL 100 IS E12 BP 26305 EP 26315 DI 10.1029/95JE02776 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP057 UT WOS:A1995TP05700003 ER PT J AU Bills, BG Nerem, RS AF Bills, BG Nerem, RS TI A harmonic analysis of Martian topography SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MARS; INERTIA; VENUS; SPECTRA; MOMENT; EARTH AB The topography of Mars is represented by a spherical harmonic model complete to degree and order 50. The data source is a recently revised U.S. Geological Survey compilation which encompasses a diverse array of spacecraft measurements and Earth-based radar ranges. Because of the disparate nature of the original data sources, it is difficult to obtain reliable estimates of the likely errors in Martian topography. However, the variance spectrum has a shape similar to that found for other terrestrial planets, and the topography correlates well with recent estimates of the gravitational field of Mars. Both of these considerations suggest that the existing data provide a reasonable approximation to the true topography of Mars. Nevertheless, a detailed topographic mapping of the planet, such as will be provided by the Mars Global Surveyor, will be required before significant advances are made in understanding the relationship between topography and gravity on Mars. C1 JOHNS HOPKINS UNIV,DEPT EARTH & PLANETARY SCI,BALTIMORE,MD 21218. NASA,GODDARD SPACE FLIGHT CTR,SPACE GEODESY BRANCH,GREENBELT,MD 20771. RP Bills, BG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,GREENBELT,MD 20771, USA. RI Bills, Bruce/C-1156-2008 NR 22 TC 9 Z9 9 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 25 PY 1995 VL 100 IS E12 BP 26317 EP 26326 DI 10.1029/95JE03101 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP057 UT WOS:A1995TP05700004 ER PT J AU Murphy, JR Pollack, JB Haberle, RM Leovy, CB Toon, OB Schaeffer, J AF Murphy, JR Pollack, JB Haberle, RM Leovy, CB Toon, OB Schaeffer, J TI Three-dimensional numerical simulation of Martian global dust storms SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GENERAL-CIRCULATION MODEL; MARS ATMOSPHERIC DYNAMICS; INTERANNUAL VARIABILITY; INFRARED SPECTROSCOPY; MARINER-9; TRANSPORT; OPACITY; TIDES AB We present results from the first numerical simulations of simultaneously evolving three-dimensional thermal, dynamical, and radiatively active suspended dust fields in the Martian atmosphere. Simulations of southern summer dust storms (arising from a prescribed southern subtropical surface dust source) conducted with a Mars general circulation model (GCM) illustrate the important role of dust transport by atmospheric eddies. Both traveling and stationary eddies contribute to dust transport to high latitudes in both hemispheres. These hemispheric differences arise from seasonal and topographic effects. Transport into the south polar regions is accomplished primarily by thermally and topographically forced standing eddies. Both traveling and stationary eddies transport dust to middle and high northern (winter) latitudes. Atmospheric wave motions are affected by the developing storms. Thermal tidal amplitudes increase at storm onset, with the calculated pressure response at a model grid point corresponding to the location of the Viking Lander 1 site in good agreement with observations. In qualitative agreement with observations, winter hemisphere baroclinic waves weaken during the early stages of the storm, but as the storm wanes, amplitudes of these waves increase. A slowly westward propagating (9 degrees of longitude per sol) zonal wavenumber one feature in the temperature and geopotential fields at middle northern latitudes amplifies rapidly during the initial sols (Martian solar days) of the simulated storms. This feature is suggestive of the observed north polar warming which occurred during the 1977B global dust storm, but the simulations produce a much weaker polar warming (similar to 10 K at 0.5 mbar) than was observed (40-50 K). The globally integrated CO2 condensation rate decreases by 15-20% during the simulated dust storm onset and would likely be decreased more if a stronger polar warming were produced. During the initial stages of the simulated storms, surface stress values in the southern subtropics intensify due primarily to the intensification of the Hadley circulation and thermally driven tides. This supports the hypothesis that these components of the general circulation contribute strong positive feedbacks to the developing storms. C1 NASA,AMES RES CTR,NATL RES COUNCIL,MOFFETT FIELD,CA 94035. WASHINGTON UNIV,DEPT ATMOSPHER SCI,SEATTLE,WA 98195. STERLING SOFTWARE INC,PALO ALTO,CA 94303. NR 58 TC 52 Z9 52 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 25 PY 1995 VL 100 IS E12 BP 26357 EP 26376 DI 10.1029/95JE02984 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP057 UT WOS:A1995TP05700008 ER PT J AU Ajello, JM Kanik, I Ahmed, SM Clarke, JT AF Ajello, JM Kanik, I Ahmed, SM Clarke, JT TI Line profile of H Lyman alpha from dissociative excitation of H-2 with application to Jupiter SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID TRANSLATIONAL ENERGY-DISTRIBUTION; ULTRAVIOLET SPECTROMETER OBSERVATIONS; ELECTRON-IMPACT DISSOCIATION; VACUUM ULTRAVIOLET; E-H-2 COLLISIONS; DOPPLER PROFILE; HYDROGEN; EMISSIONS; URANUS; AURORA AB Observations of the H Lyman alpha (Ly alpha) emission from Jupiter have shown pronounced emissions, exceeding solar fluorescence, in the polar aurora and equatorial ''bulge'' regions. The H Ly alpha line profiles from these regions are broader than expected, indicating high-energy processes producing fast atoms as determined from the observed Doppler broadening. Toward understanding that process a high-resolution ultraviolet (UV) spectrometer was employed for the first measurement of the H Ly alpha emission Doppler profile from dissociative excitation of H-2 by electron impact. Analysis of the deconvolved line profile reveals the existence of a narrow central peak of 40 +/- 4 m Angstrom full width at half maximum and a broad pedestal base about 240 m Angstrom wide. Two distinct dissociation mechanisms account for this Doppler structure. Slow H(2p) atoms characterized by a distribution function with peak energy near 80 meV produce the peak profile, which is nearly independent of the electron impact energy. Slow H(2p) atoms arise from direct dissociation and predissociation of singly excited states which have a dissociation limit of 14.68 eV. The wings of H Ly alpha arise from dissociative excitation of a series of doubly excited states which cross the Franck-Condon region between 23 and 40 eV. The profile of the wings is dependent on the electron impact energy, and the distribution function of fast H(2p) atoms is therefore dependent on the electron impact energy. The fast atom kinetic energy distribution at 100 eV electron impact energy spans the energy range from 1 to 10 eV with a peak near 4 eV. For impact energies above 23 eV the fast atoms contribute to a slightly asymmetric structure of the line profile. The absolute cross sections of the H Ly alpha line peak and wings were measured over the range from 0 to 200 eV. Analytic model coefficients are given for the measured cross sections which can be applied to planetary atmosphere auroral and dayglow calculations. The dissociative excitation process, while one contributing process, appears insufficient by itself to explain the line broadening observed at Jupiter. C1 UNIV MICHIGAN,DEPT ATMOSPHER OCEAN & SPACE SCI,ANN ARBOR,MI 48109. RP Ajello, JM (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. RI Clarke, John/C-8644-2013 NR 31 TC 26 Z9 26 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 25 PY 1995 VL 100 IS E12 BP 26411 EP 26420 DI 10.1029/95JE02360 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP057 UT WOS:A1995TP05700012 ER PT J AU Rao, MVVS Iga, I Srivastava, SK AF Rao, MVVS Iga, I Srivastava, SK TI Ionization cross-sections for the production of positive ions from H2O by electron impact SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID DISSOCIATIVE IONIZATION; NH3; WATER; GAS AB Cross-section values for the direct and dissociative ionization of H2O by electron impact have been measured and compared with previously published data. The present measurements have been carried out from thresholds to 1 keV by utilizing a crossed electron beam and molecular beam collision geometry and an improved ion extraction technique. To the best of our knowledge, the present results for the double ionization of H2O are the first measurements. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RI Iga, Ione/C-1273-2015 NR 14 TC 43 Z9 43 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 25 PY 1995 VL 100 IS E12 BP 26421 EP 26425 DI 10.1029/95JE02314 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP057 UT WOS:A1995TP05700013 ER PT J AU Partridge, H Bauschlicher, CW AF Partridge, H Bauschlicher, CW TI The dissociation energies of CH4 and C2H2 revisited SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GAUSSIAN-BASIS SETS; CONFIGURATION-INTERACTION CALCULATIONS; CORRELATED MOLECULAR CALCULATIONS; ANHARMONIC-FORCE FIELD; ATOMIC BASIS SETS; FIRST-ROW ATOMS; ELECTRON CORRELATION; MOLLER-PLESSET; WAVE-FUNCTIONS; ACETYLENE AB The bond dissociation energies of CH4, C2H2, and their fragments are investigated using basis set extrapolations and high levels of correlation. The computed bond dissociation energies (D-e) are accurate to within 0.2 kcal/mol. The agreement with the experimental (D-O) values is excellent if we assume that the zero-point energy of C2H is 9.18 kcal/mol. The effect of core (carbon Is) correlation on the bond dissociation energies of C-H bonds is shown to vary from 0.2 to 0.7 kcal/mol and that for C-C bonds it varies from 0.4 to 2.2 kcal/mol. RP NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NR 64 TC 31 Z9 31 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 22 PY 1995 VL 103 IS 24 BP 10589 EP 10596 DI 10.1063/1.469843 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TL517 UT WOS:A1995TL51700021 ER PT J AU SIGL, G LEE, S SCHRAMM, DN BHATTACHARJEE, P AF SIGL, G LEE, S SCHRAMM, DN BHATTACHARJEE, P TI A GAP IN THE HIGHEST ENERGY COSMIC-RAY SPECTRUM AS A SIGNATURE OF UNIFICATION SCALE PHYSICS SO SCIENCE LA English DT Article ID TOPOLOGICAL DEFECTS; ORIGIN AB Recent experimental data seem to indicate that there is significant structure in the cosmic ray spectrum above 10(18) electron volts (eV). Besides a dip at similar to 5 x 10(18) eV, two events above 2 10(20) eV have been observed. The implications for the existence of the Greisen-Zatsepin-Kuzmin cutoff, a long-lasting and still open question in cosmic ray physics, are discussed. This cutoff at a few times 10(19) eV, caused by energy losses in the cosmic microwave background, has been predicted to occur in most acceleration models involving extragalactic sources. An acceleration origin of particles above 10(20) eV within a few megaparsecs cannot be ruled out yet. However, persistence of the apparent gap in the existing data at a quadrupled total exposure would rule out many acceleration models at the 99 percent Confidence level for any source distance. Particles above 10(20) eV might then be directly produced by decay from some higher energy scale in contrast to acceleration of charged particles. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. INDIAN INST ASTROPHYS,BANGALORE 560034,KARNATAKA,INDIA. RP SIGL, G (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637, USA. OI Sigl, Guenter/0000-0002-4396-645X NR 36 TC 38 Z9 38 U1 0 U2 1 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 22 PY 1995 VL 270 IS 5244 BP 1977 EP 1980 DI 10.1126/science.270.5244.1977 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TL420 UT WOS:A1995TL42000037 ER PT J AU Ahmad, Z Bhartia, PK AF Ahmad, Z Bhartia, PK TI Effect of molecular anisotropy on backscattered ultraviolet radiance SO APPLIED OPTICS LA English DT Article AB The effect of molecular anisotropy on backscattered UV (BUV) radiances is computed by accounting for it in both Rayleigh optical thickness and the scattering-phase matrix. If the effect of molecular anisotropy is included only in the optical thickness and not in the phase matrix, then for high sun (theta(0) similar to 0 degrees), the nadir radiance (I-0) leaving the top of the atmosphere is approximately 1.8% higher than the radiance (I-op) computed with the effect included in the phase matrix. For very low sun (theta(0) > 80 degrees), I-0 is approximately 2.3% lower than I-op. For off-nadir radiances the relative increase (decrease) depends on both the local zenith angle as well as the azimuth angle. Also, an increase in the surface reflectivity decreases the effect of molecular anisotropy on the upwelling radiances. Exclusion of the anisotropy factor in the Rayleigh-phase matrix has very little effect (<1%) on ozone retrieval from the BUV-type instruments. This is because of the ratio technique used in the retrieval algorithm, which practically cancels out the anisotropy effect. (C) 1995 Optical Society of America C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Ahmad, Z (reprint author), SCI & DATA SYST INC,16509 COPPERSTRIP LANE,SILVER SPRING,MD 20906, USA. RI Bhartia, Pawan/A-4209-2016 OI Bhartia, Pawan/0000-0001-8307-9137 NR 21 TC 5 Z9 5 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 20 PY 1995 VL 34 IS 36 BP 8309 EP 8314 DI 10.1364/AO.34.008309 PG 6 WC Optics SC Optics GA TP714 UT WOS:A1995TP71400011 PM 21068951 ER PT J AU Pogorzelski, RJ AF Pogorzelski, RJ TI Provision of exact formulations for the ''forward scattering of a Gaussian beam by a nonabsorbing sphere'': Comment SO APPLIED OPTICS LA English DT Article DE generalized Lorenz-Mie theory; Gaussian beam; diffraction AB The purpose of an earlier publication [Appl. Opt. 34, 2120 (1995)], to provide an exact formulation of the scattering of beamlike radiation fields from spheres, is clarified and its relation to the treatment of this subject in two more recent publications is described. Also, an error in the reference list in the earlier publication is rectified. (C) 1995 Optical Society of America RP Pogorzelski, RJ (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 6 TC 2 Z9 2 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 20 PY 1995 VL 34 IS 36 BP 8474 EP 8474 DI 10.1364/AO.34.008474 PG 1 WC Optics SC Optics GA TP714 UT WOS:A1995TP71400028 PM 21068968 ER PT J AU SINGH, KP BARRETT, P WHITE, NE GIOMMI, P ANGELINI, L AF SINGH, KP BARRETT, P WHITE, NE GIOMMI, P ANGELINI, L TI THE SOFTEST X-RAY SOURCES IN THE ROSAT POINTED CATALOG - WGACAT SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, ACTIVE; NOVAE, CATACLYSMIC VARIABLES; WHITE DWARFS; X-RAYS ID PLANETARY-NEBULAE AB We present a selection of X-ray sources with the softest observed spectral characteristics and discuss their nature. These ''ultrasoft'' sources were detected in 3 years of pointings with the ROSAT. These sources are predominantly found to be white dwarfs, magnetic cataclysmic variables, nearby late-type stars, and very X-ray soft active galactic nuclei. The broadband colors of the unidentified ultrasoft sources suggest that a number of them may have at least two components in their spectrum, as for example, is found in most cataclysmic variables. Some of these objects may represent the extreme of their respective populations, for example, unusual galaxies, ''supersoft'' sources with steep low-energy spectrum and high X-ray luminosity (similar to 10(38) ergs s(-1)), active galactic nuclei, stars, etc. Follow-up studies in the optical and other wavebands are needed. C1 ESRIN,ESA,DIV INFORMAT SYST,EUROPEAN SPACE INFORMAT SYST,I-00044 FRASCATI,ITALY. RP SINGH, KP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. RI White, Nicholas/B-6428-2012; OI White, Nicholas/0000-0003-3853-3462; giommi, paolo/0000-0002-2265-5003 NR 30 TC 15 Z9 15 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 456 EP 467 DI 10.1086/176595 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500010 ER PT J AU BARCONS, X FRANCESCHINI, A DEZOTTI, G DANESE, L MIYAJI, T AF BARCONS, X FRANCESCHINI, A DEZOTTI, G DANESE, L MIYAJI, T TI HARD X-RAY-EMISSION FROM EXTRAGALACTIC IRAS 12-MICRON SOURCES - CONSTRAINTS ON THE UNIFIED ACTIVE GALACTIC NUCLEUS MODEL AND THE SYNTHESIS OF THE X-RAY-BACKGROUND SO ASTROPHYSICAL JOURNAL LA English DT Article DE DIFFUSE RADIATION; GALAXIES, ACTIVE; GALAXIES, SEYFERT; INFRARED, GALAXIES X-RAYS, GALAXIES ID N-LOG S; NEARBY GALAXIES; SAMPLE; LUMINOSITY; SPECTRUM AB We analyze the 2-10 keV X-ray emission of recently compiled complete samples of active galactic nuclei (AGNs) and galaxies selected at 12 mu m. The content in active galaxies of the 12 mu m sample is indeed much larger and less biased against low-luminosity and ''hidden'' active nuclei than samples selected at other wavelengths. As a necessary complement, we also study the IR emissivity of the largest sample of hard-X-ray-selected AGNs. Our purposes are to probe the unified scheme of active nuclei and to evaluate the local X-ray volume emissivity of low-luminosity and ''hidden'' AGNs. Two methods are used in our analysis to search for X-ray emission in the HEAO I A-2 all-sky maps from the extragalactic sources contained in the extended 12 mu m sample: an X-ray intensity distribution analysis around the known positions of the sources and a cross-correlation function analysis between galaxy densities and X-ray intensities in the high Galactic latitude sky (\b\ > 25 degrees), where the catalog is more than 98% complete. The joint analysis of the X-ray-selected and 12 mu m-selected samples enables us to define the relationship between the X-ray and the mid-IR emissions of Seyfert nuclei. In particular, we find congruence between the hard X-ray and mid-IR Seyfert 1 nuclear-luminosity functions when a nonlinear relation L(12 mu m) proportional to L(5 keV)(0.8) is with appropriate dispersion, Although this result is easily explained by circumnuclear reradiation as the main source of the mid-IR emission, it nonetheless argues against the simplest version of the unified model for active nuclei. We confirm that X-ray emission is basically restricted to AGNs, finding Seyfert 1's to be much more powerful emitters than Seyfert 2's. We find no signal of X-ray emission for the remaining galaxies selected at 12 mu m, not even for those having a flat far-IR spectrum, which are prime candidates to host hidden AGNs. Our result on the local volume emissivity of the Seyfert 1's is fully consistent with those that we derive from studies of the hard X-ray luminosity function, The 95% upper limits to the local emissivity that we derive for the Seyfert 2 class and for the most likely ''hidden'' AGN candidates are consistent with models of the X-ray background recently proposed based on the unified Seyfert scheme. We also find that less than similar to 20% of Seyfert 1-like AGNs and less than similar to 50% of Seyfert 2-like AGNs can be ''hidden'' in the non-Seyfert-galaxy samples, assuming that the X-ray-to-12 mu m flux ratios measured in the 12 mu m-selected samples can be considered typical for these classes of objects. In this case, the number ratio of Seyfert 2 to Seyfert 1 galaxies ranges from 1 to 2. C1 OSSERV ASTRON PADOVA,I-35122 PADUA,ITALY. SCUOLA INT SUPER STUDI AVANZATI,SCH ADV INT STUDIES,I-34014 TRIESTE,ITALY. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742. RP BARCONS, X (reprint author), UNIV CANTABRIA,CSIC,INST FIS CANTABRIA,E-39005 SANTANDER,SPAIN. RI Barcons, Xavier/L-3335-2014 OI Barcons, Xavier/0000-0003-1081-8861 NR 35 TC 37 Z9 37 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 480 EP 491 DI 10.1086/176597 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500012 ER PT J AU YAQOOB, T SERLEMITSOS, PJ PTAK, A MUSHOTZKY, R KUNIEDA, H TERASHIMA, Y AF YAQOOB, T SERLEMITSOS, PJ PTAK, A MUSHOTZKY, R KUNIEDA, H TERASHIMA, Y TI THE HARD X-RAY-EMISSION OF NGC-3628 AND THE CONTRIBUTION OF LOW-LUMINOSITY SPIRAL GALAXIES TO THE COSMIC X-RAY-BACKGROUND SO ASTROPHYSICAL JOURNAL LA English DT Article DE DIFFUSE RADIATION; GALAXIES, INDIVIDUAL (NGC 3628); GALAXIES, SPIRIAL; GALAXIES, STARBURST; X-RAYS, GALAXIES ID ACTIVE GALACTIC NUCLEI; SPECTRUM; GINGA; HOLE AB We discuss the results of ASCA and ROSAT observations of the spiral galaxy NGC 3628, which has been previously classified as a starburst. However, X-ray variability establishes the origin of the nuclear emission in a single, compact source, but the luminosity of similar to 3.4 x 10(40) ergs s(-1) is similar to 270 times too large for sub-Eddington accretion onto a 1 M. stellar object. Although the ASCA spectrum can be described by a flat power law with a photon index Gamma similar to 1.2, the low statistical quality of the data may conceal a more complex spectrum. However, the observed spectrum appears to be much flatter than those of prototypical starburst galaxies, such as NGC 253. The spectrum is harder than Galactic low-mass X-ray binary or black-hole candidate spectra but compatible with high-mass X-ray binary spectra. If the nuclear source is a low-luminosity active galactic nucleus (AGN), the X-ray properties have more in common with Seyfert 1-1.5 galaxies with moderate absorption (similar to 10(22) cm(-2)) than with heavily obscured Seyfert 2 galaxies. We also present the first X-ray spectral measurements of the off-nuclear source in NGC 3628 and find it has a steeper spectrum, with Gamma > 2.0 and an ASCA luminosity of about half that of the nuclear source. In the light of this and other new ASCA observations, we revisit the general problem of the contribution of low-luminosity spiral galaxies to the cosmic X-ray background (CXB) and assess their effect on the parameters of unified AGN models of the CXB as a function of their local luminosity density and X-ray spectral shape. C1 UNIV SPACE RES ASSOC,WASHINGTON,DC. UNIV MARYLAND,COLLEGE PK,MD 20742. NAGOYA UNIV,DEPT ASTROPHYS,CHIKUSA KU,NAGOYA,AICHI 46401,JAPAN. RP YAQOOB, T (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. NR 50 TC 27 Z9 27 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 508 EP 515 DI 10.1086/176600 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500015 ER PT J AU KALLMAN, TR AF KALLMAN, TR TI THE IRON L/K EMISSION-LINE RATIO IN PHOTOIONIZED GASES SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATOMIC PROCESSES; BINARIES, CLOSE; GALAXIES, ACTIVE ID COMPTON HEATED WINDS; ACCRETION DISKS; K LINE; CORONAE; IONIZATION AB We present models for the emission spectra of photoionized gases in the intermediate energy (0.5-10 keV) X-ray region. We discuss the general properties of iron K and L shell emission features-line strengths and recombination continuum emission-and compare the strengths of these features with iron K shell emission and with the spectral features produced by other elements in the same energy range. We show that there is effectively an upper bound to the L/K ratio, and we compare this with the strengths of the features observed from medium-resolution spectra of X-ray binaries and active galaxies. RP KALLMAN, TR (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. NR 24 TC 19 Z9 19 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 603 EP 613 DI 10.1086/176608 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500023 ER PT J AU CHAKRABARTI, SK TITARCHUK, LG AF CHAKRABARTI, SK TITARCHUK, LG TI SPECTRAL PROPERTIES OF ACCRETION DISKS AROUND GALACTIC AND EXTRAGALACTIC BLACK-HOLES SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCRETION, ACCRETION DISKS; BLACK HOLE PHYSICS; RADIATION MECHANISMS, NONTHERMAL SHOCK WAVES; STARS, NEUTRON ID X-RAY-EMISSION; SEYFERT-1 GALAXIES; STANDING SHOCKS; LINE REGION; NUCLEI; RADIATION; QUASARS; COMPTONIZATION; VARIABILITY; MODELS AB We study the spectral properties of a very general class of accretion disks which can be decomposed into three distinct components apart from a shock at r = r(s): (1) An optically thick Keplerian disk on the equatorial plane (r > r(s)); (2) a sub-Keplerian optically thin halo above and below this disk r > r(s); and (3) a hot, optically slim tau similar to 1 postshock region r < r(s) similar to 5-10r(g) where r(g) is the Schwarzschild radius. The postshock halo intercepts soft photons from the Keplerian component and reradiates them as hard X-rays and gamma rays after Comptonization. We solve two-temperature equations in the postshock region with Coulomb energy exchange between protons and electrons, and incorporating radiative processes such as bremsstrahlung and Comptonization. We also present the exact prescription to compute the reflection of the hard X-rays from the cool disk. We produce radiated spectra from both the disk components as functions of the accretion rates and compare them with the spectra of Galactic and extragalactic black hole candidates. We find that the transition from hard state to soft state is smoothly initiated by a single parameter, namely the mass accretion rate of the disk. In the soft state, when the postshock region is very optically thick and cooled down, bulk motion of the converging flow determines the spectral index to be about 1.5 in agreement with observations. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. GEORGE MASON UNIV,GREENBELT,MD 20771. NR 84 TC 324 Z9 327 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 623 EP 639 DI 10.1086/176610 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500025 ER PT J AU VRTILEK, JM HAUSER, MG AF VRTILEK, JM HAUSER, MG TI IRAS MEASUREMENTS OF DIFFUSE SOLAR-SYSTEM RADIATION - ANNUAL SKY BRIGHTNESS VARIATION AND GEOMETRY OF THE INTERPLANETARY DUST CLOUD SO ASTROPHYSICAL JOURNAL LA English DT Article DE DIFFUSE RADIATION; INFRARED, SOLAR SYSTEM; INTERPLANETARY MEDIUM ID ZODIACAL EMISSION; INFRARED-EMISSION; PHYSICAL MODEL; BANDS; MISSION; ORIGIN AB We present an overview based on IRAS data of the properties of infrared emission from the large-scale component of the interplanetary dust cloud. To assist in separating the smooth component of the interplanetary emission from Galactic emission, discrete sources, and the zodiacal emission bands, and to characterize the properties of the interplanetary emission in compact form, we introduce an empirical function whose adjustable parameters have simple geometrical interpretations. This function is fitted in a lower envelope sense to IRAS scan data; the function represents the data well, with rms residuals at 25 mu m of only similar to 0.3 MJy sr(-1) less than 1/2% of the peak emission. We use the parameters thus obtained at 12, 25, and 60 mu m to produce a simple analytical prescription for the interplanetary dust emission near a solar elongation angle of 90 degrees at any time of year. The nearly 1 yr duration of the IRAS observations permits the study of time variation of the infrared sky brightness due to the Earth's motion, and of the geometry of the interplanetary dust cloud. We employ our representation of the interplanetary dust emission to examine by several methods the location of a possible surface of symmetry of the interplanetary dust cloud. Discrepancies between these methods, generally consistent with results from other analysis approaches and sometimes other collections of data, indicate that such a surface must have substantial deviations from a plane. C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. NR 30 TC 18 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 677 EP 692 DI 10.1086/176615 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500030 ER PT J AU ASCHWANDEN, MJ SCHWARTZ, RA AF ASCHWANDEN, MJ SCHWARTZ, RA TI ACCURACY, UNCERTAINTIES, AND DELAY DISTRIBUTION OF ELECTRON TIME-OF-FLIGHT MEASUREMENTS IN SOLAR-FLARES SO ASTROPHYSICAL JOURNAL LA English DT Article DE RADIATION MECHANISMS, NONTHERMAL; SUN, CORONA; SUN, FLARES; SUN, PARTICLE EMISSION; SUN, X-RAYS, GAMMA RAYS; PARTICLE ACCELERATION ID HARD X-RAY; BURSTS; TARGET; BREMSSTRAHLUNG; ACCELERATION; PARTICLES; MODELS; BEAM AB A systematic time lag of approximate to 20 ms between the 25-50 keV and 50-100 keV hard X-ray (HXR) emission has been recently discovered in solar flares. This was interpreted in terms of electron time-of-flight differences (Aschwanden, Schwartz, & Alt 1995c). Here we attempt to determine the accuracy and uncertainties of such energy-dependent time delay measurements using burst-trigger data from DISCSC/BATSE on the CGRO spacecraft, recorded with a time resolution of 64 ms. We evaluate the time delays by cross-correlating entire flare time profiles at different energies and evaluate the statistical uncertainty of a delay measurement with a Monte Carlo method, in which random noise is added to the raw data. We examine also uncertainties resulting from aliasing, incomplete sampling, and pulse pileup. We measure the time delays tau = t(25 keV) - t(50 keV) in 622 flares, with a statistical uncertainty of u less than or equal to 32 ms in 29% of the events, or u less than or equal to 64 ms in 65% of the events. The distribution f(tau) of the time delays from all flares can be characterized with three components: (1) a Gaussian peak at tau = 23.2 +/- 1.2 ms with a standard deviation of sigma(t) = 25.5 ms, (2) a power-law tail with a slope of -2.0 for large positive delays (tau = 0.1-4 s), and (3) a power-law tail with a slope of -1.3 for large negative delays (\-tau\ = 0.1-7.7 s). The percentages of flares in these three regimes are 15%, 69%, and 16%. Flares with short delays (\tau\ less than or equal to 0.1 s) exhibit rapid fluctuations with subsecond pulses. Such rapid fluctuations are almost absent in flares with longer delays. We find also a systematic trend of softer spectra in flares with large positive delays. We develop a simple physical model that combines electron time-of-flight differences in the thin-target and thick-target model. We are able to reproduce the observed time delay distribution in the range of \tau\ less than or similar to 0.1 s, requiring a distribution of electron densities in the range of n(e) < 3.0 x 10(12) cm(-3) and flare loop heights in the range of h less than or equal to 35,000 km. Large negative delays (tau greater than or similar to -0.1 s) can be produced in low-density loops with efficient magnetic trapping. Large positive delays (tau greater than or similar to 0.1 s) occur in flares with a strong thermal component due to the convolution of the injection profile with the heating and cooling function. This study demonstrates that energy-dependent HXR time delays can be used as a diagnostic and discriminator of flare models. C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. HUGHES STX,GREENBELT,MD 20771. RP ASCHWANDEN, MJ (reprint author), UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742, USA. NR 32 TC 19 Z9 19 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 699 EP 714 DI 10.1086/176617 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500032 ER PT J AU GOPALSWAMY, N RAULIN, JP KUNDU, MR NITTA, N LEMEN, JR HERRMANN, R ZARRO, D KOSUGI, T AF GOPALSWAMY, N RAULIN, JP KUNDU, MR NITTA, N LEMEN, JR HERRMANN, R ZARRO, D KOSUGI, T TI VLA AND YOHKOH OBSERVATIONS OF AN M1.5 FLARE SO ASTROPHYSICAL JOURNAL LA English DT Article DE SUN, FLARES; SUN, MAGNETIC FIELDS; SUN, RADIO RADIATION; SUN, X-RAYS, GAMMA RAYS ID 20 CM WAVELENGTH; X-RAY TELESCOPE; SOLAR-A MISSION; RADIO-BURSTS; EMISSION AB A major solar flare (X-ray importance M1.5 and optical importance SB) was fully observed by the Very Large Array and the Yohkoh mission on 1993 April 22. Both thermal and nonthermal emissions were observed in radio. In soft X-rays, the flare was confined to a compact region in an arcade. In hard X-rays, there were two prominent footpoints, coincident in projection with the soft X-ray footpoints and located on either side of the magnetic neutral line inferred from photospheric magnetograms. The Yohkoh Bent Crystal Spectrometer (BCS) data provided important context information which was helpful in cross-checking the quantitative agreement between the radio and X-ray data. The microwave spectrum peaked around 10 GHz and showed Razin suppression in the beginning. Later on, the low-frequency spectral index dropped to a value of 2, suggesting thermal emission. The VLA images of the flare at 1.5 GHz show that the flare emission started as a single source above one footpoint; later on, the emission centroid moved toward the soft X-ray structure to finally become cospatial with the latter. The two locations of the 20 cm source corresponded to nonthermal (footpoint source) and thermal (source cospatial with the soft X-ray structure) emissions. We performed temperature and emission measure analysis of the X-ray data (SXT, BCS, and HXT) and used them as input to determine the expected radio emission. While there is morphological agreement between the radio and soft X-ray structures in the thermal phase, the 20 cm brightness temperature shows quantitative agreement with temperature derived from the BCS data. We were able to identify three emission mechanisms contributing to the 20 cm radio emission at different times without any ad hoc assumption regarding emission mechanisms. Razin-suppressed nonthermal gyroresonance emission, plasma emission, and thermal free-free emission seem to be operating and are found to be consistent with the plasma parameters derived from the X-ray data. The magnetic field structure in the flaring region showed differences before and after the flare as traced by soft X-ray structures in the flaring region and confirmed by 20 cm radio images. The superhot component with a temperature of 32 MK was observed in hard X-ray images and in light curves during the impulsive phase of the flare with possible radio signatures at 20 cm wavelength. We derived the physical parameters of the flaring plasma, the magnetic field, and the characteristics of nonthermal particles in the flaring region. C1 LOCKHEED PALO ALTO RES LABS,PALO ALTO,CA 94304. APPL RES CORP,LANDOVER,MD 20785. UNIV BERN,INST APPL PHYS,CH-3012 BERN,SWITZERLAND. NASA,GODDARD SPACE FLIGHT CTR,APPL RES CORP,GREENBELT,MD 20771. NATL ASTRON OBSERV,MITAKA,TOKYO 181,JAPAN. RP GOPALSWAMY, N (reprint author), UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742, USA. RI Gopalswamy, Nat/D-3659-2012; OI Gopalswamy, Nat/0000-0001-5894-9954 NR 22 TC 24 Z9 25 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 715 EP 732 DI 10.1086/176618 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500033 ER PT J AU FLEMING, J BRAGE, T BELL, KL VAECK, N HIBBERT, A GODEFROID, MR FISCHER, CF AF FLEMING, J BRAGE, T BELL, KL VAECK, N HIBBERT, A GODEFROID, MR FISCHER, CF TI SYSTEMATIC STUDIES OF N-IV TRANSITIONS OF ASTROPHYSICAL IMPORTANCE SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATOMIC DATA; ATOMIC PROCESSES ID OSCILLATOR-STRENGTHS; GENERAL PROGRAM; PROBABILITIES; SEQUENCE; IONS; LINE; POLARIZABILITIES; STATES AB E1, M2, M1 and E2 rates of transitions between n = 2 levels of N IV have been calculated using the tw independent codes CIV3 and MCHF. Convergence of each of the approaches has been studied and comparisons made as the complexity of the calculations increases to include valence, core-valence and core-core correlation. The agreement between the two methods is sufficiently good to allow us to set quite narrow uncertainty bars. For the S-1-P-1 degrees resonance line, our recommended f-value is 0.609 with an estimated uncertainty of 0.002, while our recommended A-value for the S-1(0)-P-3(1) degrees intercombination line is 580 s(-1) with an estimated uncertainty of 10 s(-1). C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NATL RES COUNCIL,GREENBELT,MD 20771. FREE UNIV BRUSSELS,CHIM PHYS MOLEC LAB,B-1050 BRUSSELS,BELGIUM. VANDERBILT UNIV,DEPT COMP SCI,NASHVILLE,TN 37235. RP FLEMING, J (reprint author), QUEENS UNIV BELFAST,DEPT APPL MATH & THEORET PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. OI Brage, Tomas/0000-0003-3985-767X NR 30 TC 36 Z9 36 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 758 EP 768 DI 10.1086/176621 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500036 ER PT J AU JAMES, GK KANIK, I AJELLO, JM AF JAMES, GK KANIK, I AJELLO, JM TI FAR-ULTRAVIOLET EMISSION CROSS-SECTIONS OF NE-II AND NE-III EXCITED BY ELECTRON-IMPACT SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATOMIC DATA; ATOMIC PROCESSES; METHODS, LABORATORY ID CLOUD PLANETARY-NEBULAE; EXTREME-ULTRAVIOLET; VACUUM ULTRAVIOLET; EXCITATION; SPECTRUM; IONIZATION; HELIUM; NOVA AB We have measured the electron-impact-induced fluorescence spectrum of neon in the wavelength range 120-270 nm at a spectral resolution of 0.43 nm (FWHM). The strongest lines observed in the far-ultraviolet (FUV) spectrum of neon are assigned to terms of the doublet system of Ne II (2s(2)2p(4)nl) and the triplet system of Ne III (2s(2)2p(3)3l). Our FUV spectral data, obtained at 300 eV electron-impact energy, provide absolute emission cross sections of these Ne II and Ne III lines, and are compared to previous measurements where available. In addition, the excitation function of the strongest Ne II line observed at 191.6 nm was measured from threshold to 1000 eV electron-impact energy. RP JAMES, GK (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 46 TC 6 Z9 6 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP 769 EP 777 DI 10.1086/176622 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK125 UT WOS:A1995TK12500037 ER PT J AU COPI, CJ SCHRAMM, DN TURNER, MS AF COPI, CJ SCHRAMM, DN TURNER, MS TI BIG-BANG NUCLEOSYNTHESIS AND A NEW APPROACH TO GALACTIC CHEMICAL EVOLUTION SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMOLOGY, THEORY; GALAXY, ABUNDANCES; GALAXY, EVOLUTION; ISM, ABUNDANCES; NUCLEAR REACTIONS, NUCLEOSYNTHESIS, ABUNDANCES ID PRIMORDIAL NUCLEOSYNTHESIS; LIGHT ELEMENTS; DEUTERIUM; ORIGIN; STARS; RATIO AB Big bang production of deuterium is the best indicator of the baryon density; however, only the present abundance of D is known (and only locally) and its chemical evolution is intertwined with that of He-3. Because Galactic abundances are spatially heterogeneous, mean chemical-evolution models are not well suited for extrapolating the pre-solar D and He-3 abundances to their primeval values. We introduce a new approach which explicitly addresses heterogeneity by statistically tracing the history of the pre-solar material back to its primeval beginning. We show that the decade-old concordance interval eta approximate to (2-8)x10(-10) based on D and He-3 is well founded. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP COPI, CJ (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637, USA. NR 30 TC 37 Z9 37 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP L95 EP L98 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK126 UT WOS:A1995TK12600001 ER PT J AU RAMATY, R MANDZHAVIDZE, N KOZLOVSKY, B MURPHY, RJ AF RAMATY, R MANDZHAVIDZE, N KOZLOVSKY, B MURPHY, RJ TI SOLAR ATMOSPHERIC ABUNDANCES AND ENERGY CONTENT IN FLARE-ACCELERATED IONS FROM GAMMA-RAY SPECTROSCOPY SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCELERATION OF PARTICLES; NUCLEAR REACTIONS, NUCLEOSYNTHESIS, ABUNDANCES; SUN, ABUNDANCES; SUN, FLARES; SUN, X-RAYS, GAMMA RAYS AB We used SMM gamma-ray data from 19 solar flares to study ambient elemental abundances in the solar atmosphere. We found that the abundance ratios of low FIP (first ionization potential) to high FIP elements are enhanced relative to photospheric abundances, but that the variability of these ratios from flare to flare is limited to a narrower range than that inferred from EUV and X-ray observations. The mean of the gamma-ray derived Mg/O (a low FIP to high FIP element abundance ratio) is coronal and the individual values are always higher than the photospheric Mg/O. The value of Ne/O (similar to 0.25) is higher than the coronal value of 0.15 obtained from solar energetic particle data, but not inconsistent with some EUV and X-ray determinations. To avoid Ne/O higher than 0.3 a steep accelerated particle energy spectrum extending down to about 1 MeV per nucleon is needed. This implies that a large fraction of the available flare energy is contained in accelerated ions. C1 TEL AVIV UNIV,SCH PHYS & ASTRON,RAMAT AVIV,ISRAEL. USN,RES LAB,EO HULBURT CTR ASTROPHYS,WASHINGTON,DC 20375. RP RAMATY, R (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. NR 14 TC 119 Z9 119 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP L193 EP L196 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK126 UT WOS:A1995TK12600024 ER PT J AU RUIZ, MT BERGERON, P LEGGETT, SK ANGUITA, C AF RUIZ, MT BERGERON, P LEGGETT, SK ANGUITA, C TI THE EXTREMELY LOW-LUMINOSITY WHITE-DWARF ESO-439-26 SO ASTROPHYSICAL JOURNAL LA English DT Article DE STARS, EVOLUTION; STARS, INDIVIDUAL (ESO 439-26); WHITE DWARFS ID AGE AB We present a detailed analysis of the extremely low luminosity white dwarf ESO 439-26. The measured trigonometric parallax of pi = 0 ''.0237 +/- 0 ''.0030, together with the observed V magnitude of 20.52, yields an absolute visual magnitude of M(V) = 17.4 +/- 0.3. ESO 439-26 thus lies more than 1 mag faintward of the observed cutoff of the white-dwarf luminosity function in the Galactic disk and could therefore be the coolest and hence oldest white dwarf ever detected. However, we show from a detailed analysis of the optical energy distribution that the intrinsic low luminosity of ESO 439-26 is the result of its small radius, or large mass. Our best solution is reached with T-eff = 4560 +/- 100 K, log g = 9.04 +/- 0.14, and a pure-helium atmospheric composition. Evolutionary models are used to derive a mass of M = 1.21 +/- 0.07 M(.) and a cooling age of 6.4 +/- 0.3 Gyr, a value that is smaller than the current estimates of the age of the Galactic disk. C1 UNIV MONTREAL,DEPT PHYS,MONTREAL,PQ H3C 3J7,CANADA. NASA,INFRARED TELESCOPE FACIL,HILO,HI 96720. AURA INC,NATL OPT ASTRON OBSERV,CERRO TOLOLO INTERAMER OBSERV,WASHINGTON,DC. RP RUIZ, MT (reprint author), UNIV CHILE,DEPT ASTRON,CASILLA 36-D,SANTIAGO,CHILE. RI Ruiz, Maria Teresa/I-5770-2016; OI Ruiz, Maria Teresa/0000-0002-6799-1537; Leggett, Sandy/0000-0002-3681-2989 NR 13 TC 27 Z9 27 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 1995 VL 455 IS 2 BP L159 EP L162 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK126 UT WOS:A1995TK12600016 ER PT J AU Hall, FG Sellers, PJ AF Hall, FG Sellers, PJ TI First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) in 1995 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material ID VEGETATION INDEXES; PHOTOSYNTHESIS; CONDUCTANCE; REFLECTANCE; EXCHANGE; BUDGET; CO2 AB The history and goals of FIFE are briefly reviewed. The papers in this special issue are summarized under the headings of ''Remote Sensing Science'' and ''Modeling.'' The significant contributions of FIFE to Earth System Science are itemized and discussed. RP Hall, FG (reprint author), NASA, GODDARD SPACE FLIGHT CTR, MC 923, GREENBELT, MD 20777 USA. NR 53 TC 30 Z9 30 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1995 VL 100 IS D12 BP 25383 EP 25395 DI 10.1029/95JD03300 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100001 ER PT J AU Goetz, SJ Halthore, RN Hall, FG Markham, BL AF Goetz, SJ Halthore, RN Hall, FG Markham, BL TI Surface temperature retrieval in a temperate grassland with multiresolution sensors SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID THERMAL-INFRARED DATA; RADIOMETRIC CALIBRATION; ATMOSPHERIC CORRECTION; CANOPY TEMPERATURES; SATELLITE; FIFE AB Radiometric surface temperatures retrieved at various spatial resolutions from aircraft and satellite measurements at the FIFE site in eastern Kansas were compared with near-surface temperature measurements to determine the accuracy of the retrieval techniques and consistency between the various sensors. Atmospheric characterizations based on local radiosonde profiles of temperature, pressure, and water vapor were used with the LOWTRAN-7 and MODTRAN atmospheric radiance models to correct measured thermal radiances of water and grassland targets for atmospheric attenuation. Comparison of retrieved surface temperatures from a helicopter-mounted modular multispectral radiometer (MMR);(similar to 5-m ''pixel''), C-130 mounted thematic mapper simulator (TMS) (NS001, similar to 20-m pixel), and the Landsat 5 thematic mapper (TM) (120-m pixel) was done. Differences between atmospherically corrected radiative temperatures and near-surface measurements ranged from less than 1 degrees C to more than 8 degrees C. Corrected temperatures from helicopter-MMR and NS001-TMS were in general agreement with near-surface infrared radiative thermometer (IRT) measurements collected from automated meteorological stations, with mean differences of 3.2 degrees C and 1.7 degrees C for grassland targets. Much better agreement (within 1 degrees C) was found between the retrieved aircraft surface temperatures and near-surface measurements acquired with a hand-held mast equipped with a MMR and IRT. The NS001-TMS was also in good agreement with nearsurface temperatures acquired over water targets. In contrast, the Landsat 5 TM systematically overestimated surface temperature in all cases. This result has been noted previously but not consistently. On the basis of the results reported here, surface measurements were used to provide a calibration of the TM thermal channel. Further evaluation of the in-flight radiometric calibration of the TM thermal channel is recommended. C1 HUGHES STX CORP, GREENBELT, MD USA. RP Goetz, SJ (reprint author), NASA, GODDARD SPACE FLIGHT CTR, BIOSPHER SCI BRANCH, CODE 923, GREENBELT, MD 20771 USA. RI Markham, Brian/M-4842-2013; Goetz, Scott/A-3393-2015 OI Markham, Brian/0000-0002-9612-8169; Goetz, Scott/0000-0002-6326-4308 NR 35 TC 49 Z9 52 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1995 VL 100 IS D12 BP 25397 EP 25410 DI 10.1029/94JD02684 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100002 ER PT J AU Cooper, HJ Smith, EA Crosson, WL AF Cooper, HJ Smith, EA Crosson, WL TI Limitations in estimating surface sensible heat fluxes from surface and satellite radiometric skin temperatures SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PRAIRIE GRASSLAND; MOISTURE FLUXES; MESOSCALE CIRCULATIONS; SOIL-MOISTURE; CANOPY TEMPERATURE; BIOSPHERE MODEL; ENERGY-BALANCE; INFRARED DATA; VEGETATION; FIFE AB The objective of this study is to demonstrate that by use of simple physical techniques it is possible to obtain useful skill in retrieving sensible heat fluxes by the radiometric method but only on a site-specific basis. Sensible heat fluxes measured by Bowen ratio systems at two sites during the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) 1987 and FIFE 1989 are compared to sensible heat fluxes estimated from radiometric measurements of skin temperature taken by pyrgeometers mounted 1.75 m above the surface. An experimental version of the biosphere-atmosphere transfer scheme (Ex-BATS), capable of reproducing statistically reliable estimates of the measured heat fluxes, is used to show that good agreement can be obtained between the model-diagnosed surface temperatures and the skin temperatures obtained from the pyrgeometers. However, because of biases in the radiometer values which are small in an absolute sense but large in terms of the differential temperatures between surface and atmosphere, use of such temperatures in modified bulk formula expressions gives rise to significant biases in the sensible heat fluxes. By reconciling radiometric estimates of the sensible heat fluxes and the fluxes measured by the Bowen ratio systems, a mean effective emissivity considered in the form of a site-specific calibration constant can be calculated for each of the two sites. Using the new emissivities, corrected radiometric surface temperatures are obtained that remove the biases at each site, demonstrating that the radiometric method is feasible but only on a site-specific basis. The corrected skin temperatures are then compared to the advanced very high resolution radiometer (AVHRR)-derived split window estimates of skin temperature obtained on 30 clear-sky days during the 1987 experimental period. The two data sets are found to be well-correlated but also with an underlying bias. Differences between the satellite estimated temperatures and the corrected skin temperatures are attributed to imperfections in the coefficients used in the split window equation and residual cloud contamination, as well as considerable differences in the scenes viewed by the pyrgeometers and satellite. These differences lead to significant errors in retrieving heat fluxes from the raw satellite skin temperature estimates. The estimates can be improved after applying a regression between the corrected radiometric skin temperatures obtained for the radiometers and the satellite-derived temperatures, although because of the residual cloud effects and scene mismatch, the final RMS error is of the order of 65 W m(-2). An independent application of the regression fit between the radiometer temperatures and the AVHRR-derived temperatures derived from the 1987 data to sensible heat flux calculations for four clear-sky days in 1989 indicates poor skill, reinforcing the notion that for satellite applications the radiometric approach is also only feasible on a site-specific basis. C1 FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, UNIV SPACE RES ASSOC, HUNTSVILLE, AL 35812 USA. RP Cooper, HJ (reprint author), FLORIDA STATE UNIV, DEPT METEOROL, TALLAHASSEE, FL 32306 USA. NR 28 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 DEC 20 PY 1995 VL 100 IS D12 BP 25419 EP 25427 DI 10.1029/95JD01644 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100004 ER PT J AU Wang, JR AF Wang, JR TI Some features observed by the L-band push broom microwave radiometer over the Konza Prairie during 1985-1989 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SURFACE SOIL-MOISTURE; VEGETATION; EMISSION; MODEL; FIFE; HAPEX AB Airborne L-band radiometric measurements were conducted over the Konza Prairie near Manhattan, Kansas, in the summers of 1985, 1987, 1988, and 1989 to study the relationship among surface microwave emission, soil moisture, and vegetation cover. The annual surface treatments that were applied to the watersheds in the experimental area appeared to show a significant impact on the surface microwave emission. A watershed that was burned every year showed a better sensitivity to soil moisture variation than those burned less frequently. This feature persisted even though the radiometric measurements were made over those watersheds that were burned in the same year. It was concluded that the burning process might not completely remove a thatch layer of efficient microwave absorption, which was developed through years of accumulation of senescent vegetation. Results from the analysis of these radiometric data sets also suggest the need of an adequate estimation of vegetation biomass in order to obtain a reliable retrieval of surface soil moisture from L-band radiometric measurements. On the basis of the data acquired from the 1987 and 1989 field campaigns, the push broom microwave radiometer (PBMR) measurements are likely to give errors of the order of +/-0.065 g/cm(3) in surface soil moisture estimation if there are no measurements of vegetation biomass. Measurements of vegetation biomass to an accuracy of +/-0.46 kg/m(2) improve the corresponding PBMR estimation of surface soil moisture to an accuracy of +/-0.032 g/cm(3). RP Wang, JR (reprint author), NASA, GODDARD SPACE FLIGHT CTR, HYDROSPHER PROC LAB, CODE 975, GREENBELT, MD 20771 USA. NR 20 TC 3 Z9 3 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 DEC 20 PY 1995 VL 100 IS D12 BP 25469 EP 25479 DI 10.1029/95JD00722 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100010 ER PT J AU Saatchi, SS vanZyl, JJ Asrar, G AF Saatchi, SS vanZyl, JJ Asrar, G TI Estimation of canopy water content in Konza Prairie grasslands using synthetic aperture radar measurements during FIFE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SCATTERING; VEGETATION; MODEL; BACKSCATTERING AB This paper presents the development of an algorithm to retrieve the canopy water content of natural grasslands and pasture from synthetic aperture radar (SAR) measurements. The development of this algorithm involves three interrelated steps: (1) calibration of SAR data for ground topographic variations, (2) development and validation of backscatter model for grass canopies, and (3) estimation of canopy water content by inverting a backscattered model for cross-polarized ratio. The polarimetric radar data acquired by the Jet Propulsion Laboratory AIRSAR system during the 1989 First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) are used for this study. The SAR data have been calibrated and corrected for the topographical effects by using the digital elevation map of the study area. The backscattering coefficients obtained from the SAR data for each pixel are related to the canopy and soil parameters by employing a discrete random media model for vegetation The model simulations indicate that biomass variations and surface treatments (burned and unburned) of grass canopies affect the C-band backscatter signal but does not influence the L-band signal. This model is then validated and adjusted over training areas where ground measurements were collected. An inversion technique is proposed to estimate the canopy water content by using the cross-polarized and copolarized ratios of the SAR data at C band. The result of the inversion algorithm shows a good agreement with the grass biomass data collected during FIFE 1989 intensive field campaign. C1 NASA, WASHINGTON, DC 20546 USA. RP Saatchi, SS (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 26 TC 10 Z9 10 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1995 VL 100 IS D12 BP 25481 EP 25496 DI 10.1029/95JD00852 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100011 ER PT J AU Privette, JL Myneni, RB Emery, WJ Pinty, B AF Privette, JL Myneni, RB Emery, WJ Pinty, B TI Inversion of a soil bidirectional reflectance model for use with vegetation reflectance models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CANOPY REFLECTANCE; FACTOR DISTRIBUTIONS; SAIL MODEL; FIFE SITE; BARE SOIL; SURFACES AB The need for anisotropic soil reflectance in canopy reflectance modeling is assessed for different sampling and canopy conditions. Based on the results for grasslands, a soil model is inverted with ground-based radiometer data from the First international Satellite Land Surface Climatology Project (ISLSCP) Field Experiment(FIFE). A general solution applicable over different spectral bands, solar angles, and soil moisture levels is determined using a diverse data set. With this solution, the model can be used as a lower boundary condition in FIFE canopy modeling. Despite the previously reported independence of retrieved model parameters to data sampling conditions, solutions determined with more limited data sets vary significantly. Moreover, the semiphysically based model may not accurately predict reflectance in angular regions where data are absent in the inversion process. These findings are important for the Earth Observing System multiangle imaging spectroradiometer (MISR), which will gather data in essentially one azimuthal plane per pass like the instrument used in this study did. C1 NASA, GODDARD SPACE FLIGHT CTR, BIOSPHER SCI BRANCH, GREENBELT, MD 20771 USA. UNIV CLERMONT FERRAND, METEOROL PHYS LAB, CNRS, URA 267, F-63177 CLERMONT FERRAND, FRANCE. RP Privette, JL (reprint author), UNIV COLORADO, DEPT AEROSP ENGN SCI, CB 431, BOULDER, CO 80309 USA. RI Privette, Jeffrey/G-7807-2011; Myneni, Ranga/F-5129-2012 OI Privette, Jeffrey/0000-0001-8267-9894; NR 33 TC 22 Z9 23 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1995 VL 100 IS D12 BP 25497 EP 25508 DI 10.1029/95JD00851 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100012 ER PT J AU Russell, CA Walthall, CL Irons, JR deColstoun, ECB AF Russell, CA Walthall, CL Irons, JR deColstoun, ECB TI Comparison of airborne and surface spectral bidirectional reflectance factors, spectral hemispherical reflectance and spectral vegetation indices SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID FIFE SITE; ALBEDO; SATELLITE; NADIR; CANOPIES AB Six sets of airborne advanced solid-state array spectroradiometer (ASAS) and ground modular multiband radiometer (MMR) remotely sensed bidirectional measurements acquired over one First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment site in 1987 and 1989 were compared for the following parameters: bidirectional spectral reflectance factor, spectral hemispherical reflectance, simple ratio, and normalized difference vegetation index. ASAS at-sensor radiances were atmospherically corrected and converted to surface reflectance factors. Selected MMR bands were simulated with ASAS data, and hemispherical reflectance for both ground and airborne data sets was estimated using data collected only in or close to the solar principal plane. The shapes of the reflectance factor response curves (as a function of view zenith angle) were strongly affected by solar zenith angle and compared well between instruments. Off-nadir anisotropy in reflectance factors was comparable between sensors, while actual values of reflectance factors differed 2-35% relative between instruments in the green channel and 0-38% relative in the red channel. For the data set giving the overall closest agreement, ASAS reflectance factors differed from MMR values by 5-17% relative (0.3-1.8% absolute) in the green and 5-10% relative (0.2-0.5% absolute) in the red. These differences showed no correlation with solar zenith angle. Some of the differences were arbitrarily introduced by the 5 degrees offset in view zenith angles (except nadir) between the two instruments. Other differences were caused by the discrepancy in solar zenith angle for some of the sets, variable deviations from the solar principal plane, hotspot and associated shadowing effects not consistently recorded by both instruments, and sampled ground area variations. Estimates of hemispherical reflectance compared very well between sensors, with differences of only 3-14% relative (0.3-1.6% absolute) in the green and 11-27% relative (0.8-2.4% absolute) in the red. For the ASAS data, using atmospherically corrected reflectance factors (instead of at-sensor radiances) significantly increased the values of the spectral vegetation indices (SVIs). Off-nadir anisotropy for the SVIs derived from both sensors' data sets was less than that observed for the bidirectional reflectance factors, and NDVI off-nadir deviations were much less than those of the simple ratio (SR). Large differences in the values of SR and NDVI between sensors indicate SVIs calculated from broadband (MMR) versus narrowband (ASAS) data are not comparable. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. USDA ARS, BELTSVILLE AGR RES CTR, REMOTE SENSING RES LAB, BELTSVILLE, MD 20705 USA. UNIV SPACE RES ASSOC, SEABROOK, MD USA. RP Russell, CA (reprint author), UNIV MARYLAND, DEPT GEOG, GLOBAL REMOTE SENSING STUDIES LAB, COLLEGE PK, MD 20742 USA. RI Irons, James/D-8535-2012 NR 30 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1995 VL 100 IS D12 BP 25509 EP 25522 DI 10.1029/95JD01643 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100013 ER PT J AU deColstoun, ECB Walthall, CL Russell, CA Irons, JR AF deColstoun, ECB Walthall, CL Russell, CA Irons, JR TI Estimating the fraction of absorbed photosynthetically active radiation (fAPAR) at FIFE with airborne bidirectional spectral reflectance data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID FIELD EXPERIMENT FIFE; HEMISPHERICAL REFLECTANCE; VEGETATION INDEX; IMAGING SPECTRORADIOMETER; SURFACE REFLECTANCE; LIGHT INTERCEPTION; CANOPY REFLECTANCE; SENEGALESE SAHEL; CORN CANOPIES; WINTER-WHEAT AB The relationship between the fraction of absorbed photosynthetically active radiation (f(APAR)) and spectral vegetation indices (SVIs) is affected by various factors, including background effects and the view zenith angle of the sensor. This study investigated the effects of estimating f(APAR) from multiple off-nadir airborne measurements acquired by the advanced solid-state array spectroradiometer (ASAS) during the First International Satellite Land Surface Climatology Project Field Experiment. Using atmospherically corrected data, f(APAR) was estimated with both directional SVIs (normalized difference vegetation index (NDVI) and simple ratio (SR)) and PAR hemispherical reflectance (R(PAR)) calculated from PAR bidirectional reflectance factors for the seven viewing angles of ASAS. Very weak linear relationships were found between the ground-measured total f(APAR) values and ASAS measurements, assumed to be due to the presence of varying amounts of senescent plant materials in the canopy. Exclusion of data collected in October when the canopy was fully senescent somewhat improved these relationships. However, correction of total f(APAR) values by the fraction of green vegetation present (green f(APAR)) provided substantial improvement. For both SVIs the highest coefficients of determination (r(2) = 0.839 for NDVI; r(2) = 0.890 for SR) were found at 15 degrees in the backscattering direction decreasing to minimum values at +/-45 degrees, a trend thought to be associated with the effect of canopy structure on the SVIs. Although R(PAR) was not strongly correlated with either the total or the green f(APAR), it was related to the independently measured PAR flux reflected from the canopy indicating a potential for deriving PAR hemispherical reflectance from directional measurements for natural cover types such as grasslands. C1 NASA, GODDARD SPACE FLIGHT CTR, BIOSPHER SCI BRANCH, GREENBELT, MD 20771 USA. NASA, GODDARD SPACE FLIGHT CTR, UNIV SPACE RES ASSOC, GREENBELT, MD 20771 USA. USDA ARS, REMOTE SENSING RES LAB, BELTSVILLE, MD 20705 USA. RP deColstoun, ECB (reprint author), UNIV MARYLAND, DEPT GEOG, GLOBAL REMOTE SENSING STUDIES LAB, 1113 LEFRAK HALL, COLLEGE PK, MD 20742 USA. RI Irons, James/D-8535-2012 NR 67 TC 5 Z9 5 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 DEC 20 PY 1995 VL 100 IS D12 BP 25523 EP 25535 DI 10.1029/95JD01045 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100014 ER PT J AU Sellers, PJ Heiser, MD Hall, FG Goetz, SJ Strebel, DE Verma, SB Desjardins, RL Schuepp, PM MacPherson, JI AF Sellers, PJ Heiser, MD Hall, FG Goetz, SJ Strebel, DE Verma, SB Desjardins, RL Schuepp, PM MacPherson, JI TI Effects of spatial variability in topography, vegetation cover and soil moisture on area-averaged surface fluxes: A case study using the FIFE 1989 data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CANOPY REFLECTANCE; TALLGRASS PRAIRIE; CARBON-DIOXIDE; SATELLITE; AIRCRAFT; PHOTOSYNTHESIS; CONDUCTANCE; RADIATION; TRANSPIRATION; ALGORITHM AB A modified version of the simple biosphere model (SiB) of Sellers et al. (1986) was used to investigate the impact of spatial variability in the fields of topography, vegetation cover, and soil moisture on the area-averaged fluxes of sensible and latent heat for an area of 2 x 15 km (the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) testbed area) located within the FIFE area. This work builds on a previous study of Sellers et al. (1992a) but makes use of a superior data set (FIFE 1989 rather than FIFE 1987) and has a sharper focus on the nonlinear effects of soil wetness on evapotranspiration. The 2 x 15 km testbed area was divided into 68 x 501 pixels of 30 x 30 m spatial resolution, each of which could be assigned topographic, vegetation condition, and soil moisture parameters from satellite and in situ observations gathered in FIFE-89. One or more of these surface fields was area averaged in a series of simulation runs to determine the impact of using large-area means of these initial/boundary conditions on the area-integrated (aggregated) surface fluxes. Prior to these simulations some validation work was done with the model. The results of the study can be summarized as follows: (1) SiB was initialized with satellite and airborne remotely sensed data for vegetation condition and soil wetness, respectively. The surface fluxes calculated by SiB compared well with surface-based and airborne flux observations. (2) Analyses and some of the simulations indicated that the relationships describing the effects of moderate topography on the surface radiation budget are near linear and thus largely scale invariant. The relationships linking the simple ratio (SR) vegetation index, the canopy conductance parameter V-F, and the canopy transpiration flux are also near linear and similarly scale invariant to first order (see also Sellers et al., 1992a). Because of this it appears that simple area-averaging operations can be applied to these fields with relatively little impact on the calculated surface heat fluxes. (3) The relationships linking surface and root-zone soil wetness to the soil surface and canopy transpiration rates are nonlinear. However, simulation results and observations indicate that soil moisture variability decreases significantly as the study area dries out, which partially cancels out the effects of these nonlinear functions. (4) The near-infrared surface reflectance rho(N) estimated from atmospherically corrected satellite data may be a better predictor of vegetation condition than a two-band vegetation index, such as the SR, at least for the grasslands represented in the FIFE area. These results support the use of simple averages of topographic and vegetation parameters to calculate surface energy and heat fluxes over a wide range of spatial scales, from a few meters up to many kilometers. Although the relationships between soil moisture and evapotranspiration are nonlinear for intermediate soil wetnesses, the dynamics of soil drying act to progressively reduce soil moisture variability and thus the impacts of these nonlinearities on the area-averaged surface fluxes. These findings indicate that we can use mean values of topography, vegetation condition, and soil moisture to calculate the surface-atmosphere fluxes of energy, heat, and moisture at larger length scales to within an acceptable accuracy for climate-modeling work. C1 UNIV MARYLAND, DEPT METEOROL, COLLEGE PK, MD 20742 USA. HUGHES STX, GREENBELT, MD 20771 USA. AGR CANADA, CTR LAND & BIOL RESOURCE RES, OTTAWA, ON K1A 0C6, CANADA. VERSAR, COLUMBIA, MD 21045 USA. UNIV NEBRASKA, DEPT AGR METEOROL, LINCOLN, NE 68583 USA. MCGILL UNIV, DEPT RENEWABLE RESOURCES, ST ANNE DE BELLEVUE, PQ H9X 1C0, CANADA. NATL RES COUNCIL CANADA, OTTAWA, ON K1A 0R6, CANADA. RP Sellers, PJ (reprint author), NASA, GODDARD SPACE FLIGHT CTR, MAIL CODE 923, GREENBELT, MD 20771 USA. RI Goetz, Scott/A-3393-2015 OI Goetz, Scott/0000-0002-6326-4308 NR 34 TC 53 Z9 57 U1 1 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1995 VL 100 IS D12 BP 25607 EP 25629 DI 10.1029/95JD02205 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100022 ER PT J AU Heiser, MD Sellers, PJ AF Heiser, MD Sellers, PJ TI Production of a filtered and standardized surface flux data set for FIFE 1987 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HEAT AB A filtered and standardized surface heat flux data set, which includes net radiation (R(n)), latent heat flux; (XE), sensible heat flux (H), and ground heat flux (G), was produced from an analysis of field measurements taken by a network of 16 Bowen ratio and 6 eddy correlation instruments deployed during the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment in 1987 (FIFE 1987). The objective was to produce time series of flux data that could be used for studies involving surface-vegetation-atmosphere-transfer (SVAT) models operating in the inverse mode (see Sellers et al. 1992b). To be useful for this work, erroneous flux data had to be identified and systematic instrument-related differences between the net radiation values reported by flux stations had to be accounted for. The following procedures were carried out on the original data sets as contributed by individual FIFE scientists: (1) A flag (IDATA) was assigned to unreliable flux data as defined by the presence of anomalies (''spikes'') in the sensible and latent heat flux time series, discontinuities generated when the temperature and humidity profiles crossed over at dawn and dusk, and data points isolated by the erasure of neighboring unreliable data. In addition, Bowen ratio data were also considered to be unreliable whenever the surface energy budget was reported as nonzero (R(n) + lambda E + H + G not equal 0). (2) A simple procedure was used to adjust the net radiation values reported by two of the Bowen ratio stations to appear as if they were using the same type of net radiometer as most of the other Bowen ratio stations deployed in FIFE 1987. Corresponding changes were made to the associated sensible and latent heat fluxes for these two stations; the ground heat fluxes were left unchanged. At one eddy correlation site (site 26), the sensible and latent heat fluxes were suspected to be systematically underestimated; these were proportionately increased to match the site net radiation flux minus a FIFE-area-average ground heat flux. (3) An additional flag (IDF) was assigned to data based on modeling results obtained from the simple biosphere (SiB) model (see Sellers et al., 1992b). Nonzero values of IDF denote periods when the flux data time series diverge significantly from a set of calibrated model results, suggesting a bias in the data or indicating that SiB could not reproduce the observed latent and sensible heat Aux time series using a reasonable set of surface parameters. An IDF flag was assigned to each flux station for each intensive field campaign (IFC). (4) Using the IDATA and IDF flags to identify and exclude questionable data points, a site-averaged surface heat flux data set was computed for each IFC from the remaining data. This is compared to a similar ''hand-filtered'' data set produced by Betts and Ball as published by Strebel et al. (1994). C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RP Heiser, MD (reprint author), UNIV MARYLAND, DEPT METEOROL, COLLEGE PK, MD 20742 USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1995 VL 100 IS D12 BP 25631 EP 25643 DI 10.1029/95JD02137 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100023 ER PT J AU Schoeberl, MR Newman, PA AF Schoeberl, MR Newman, PA TI A multiple-level trajectory analysis of vortex filaments SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC POLAR VORTEX; TRANSPORT CHARACTERISTICS; GENERAL-CIRCULATION; AIR; DISTURBANCES; WARMINGS; DYNAMICS; BREAKING; WAVES; MODEL AB Simultaneous, multiple-level contour advection and reverse domain-filling simulations of the polar vortex are performed to examine the three-dimensional structure of filaments. The evolution of a contour near the vortex edge over three northern hemisphere winters is examined. The results show that filaments forming at the edge have a fairly coherent vertical structure often over the whole stratosphere. The filaments linked together form vertically aligned material sheets which tend to tilt outward with height. Three specific examples of vortex edge evolution over 10-day periods are shown; two of these examples appear to be somewhat similar to the ''remote'' and ''local'' wave-breaking cases studied by Dritschel and Savaranan [1994]. The third example, a final warming, is a combination of the two other cases. Using the change in the vortex edge contour length to compute the Liapunov coefficient, we show the variation in that quantity, the geopotential height variance, and the eddy diffusion coefficient K-yy for the three winters. The changes in Liapunov coefficient roughly correlate with the changes in the other two quantities. RP Schoeberl, MR (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ATMOSPHER CHEM & DYNAM BRANCH, CODE 916, GREENBELT, MD 20771 USA. RI Newman, Paul/D-6208-2012 OI Newman, Paul/0000-0003-1139-2508 NR 43 TC 80 Z9 80 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 DEC 20 PY 1995 VL 100 IS D12 BP 25801 EP 25815 DI 10.1029/95JD02414 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100038 ER PT J AU Marshak, A Davis, A Wiscombe, W Cahalan, R AF Marshak, A Davis, A Wiscombe, W Cahalan, R TI Radiative smoothing in fractal clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID FULLY-DEVELOPED TURBULENCE; MODEL AB Spectral and structure function analyses are used to study the smoothness properties of the radiation fields for stratiform clouds whose horizontally fluctuating extinction fields are modeled with multiplicative cascades. Models of this type are ''scale invariant,'' meaning that their two-point statistics obey power laws in the scale parameter. The independent pixel approximation (IPA) treats each pixel as a plane-parallel layer and yields scale-invariant albedo and radiance fields with the same exponents as the associated optical depth field. This is not the case with exact Monte Carlo (MC) results for which we confirm the existence of a characteristic ''radiative smoothing'' scale eta. For scales larger than eta, IPA and MC reflectance fields fluctuate together, and the IPA can be invoked to infer optical depths from measured radiances. We use a multifractal characterization of structure functions to assess the performance of such retrievals. For scales smaller than eta, MC fields are much smoother than their IPA counterparts, and IPA-based retrievals of the underlying optical depth field are unreliable. The scale break location eta has been found to he closely related to the characteristic size [rho] of the ''spot'' of multiply scattered light excited by illumination with a narrow beam, the random variable rho being the horizontal distance between photon entry and exit points. New analytical arguments are presented for thick homogeneous media showing that [rho] approximate to h[(1-g)tau](-1/2), given the cloud's optical (tau) and geometrical (h) thicknesses (g is the asymmetry factor); this result is shown to hold numerically for fractal cloud models too. An improved ''nonlocal'' IPA is defined as the convolution product of the IPA field with a gamma-type smoothing kernel dependent on [rho]. C1 SCI SYST & APPLICAT INC, LANHAM, MD USA. RP Marshak, A (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CLIMATE & RADIAT BRANCH, MC 913, GREENBELT, MD 20771 USA. RI Cahalan, Robert/E-3462-2012; Wiscombe, Warren/D-4665-2012; Marshak, Alexander/D-5671-2012 OI Cahalan, Robert/0000-0001-9724-1270; Wiscombe, Warren/0000-0001-6844-9849; NR 31 TC 130 Z9 132 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1995 VL 100 IS D12 BP 26247 EP 26261 DI 10.1029/95JD02895 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN051 UT WOS:A1995TN05100067 ER PT J AU Yang, JW Kuznia, JN Chen, QC Khan, MA George, T DeGraef, M Mahajan, S AF Yang, JW Kuznia, JN Chen, QC Khan, MA George, T DeGraef, M Mahajan, S TI Temperature-mediated phase selection during growth of GaN on (111)A and ((1)over-bar(1)over-bar(1)over-bar)B GaAs substrates SO APPLIED PHYSICS LETTERS LA English DT Article AB GaN layers having the zinc blende and wurtzite structures can be selectively deposited on (111)A and ((111) over bar)B GaAs substrates by varying the growth temperature. Using the growth temperature as a variable, layers having the two structures have been sequentially deposited. The as-grown structures have been examined by cross-sectional high resolution electron microscopy. Results indicate that the two phases once formed are structurally stable in the temperature range examined. Furthermore, the transition from GaN (zinc blende) to GaN (wurtzite) is sharp, whereas a faulted region is observed during the reverse transition. Arguments have been developed to rationalize these observations. (C) 1995 American Institute of Physics. C1 CALTECH,JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109. CARNEGIE MELLON UNIV,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15213. RP Yang, JW (reprint author), APA OPT INC,2950 NE 84TH LANE,BLAINE,MN 55449, USA. RI DeGraef, Marc/G-5827-2010 OI DeGraef, Marc/0000-0002-4721-6226 NR 9 TC 43 Z9 43 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 18 PY 1995 VL 67 IS 25 BP 3759 EP 3761 DI 10.1063/1.115374 PG 3 WC Physics, Applied SC Physics GA TK759 UT WOS:A1995TK75900030 ER PT J AU Chao, BF AF Chao, BF TI Anthropogenic impact on global geodynamics due to reservoir water impoundment SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EARTHS AB Water impounded in artificial reservoirs since similar to 1950 is by far the largest anthropogenic hydrological change in terms of the mass involved. This mass redistribution contributes to geodynamic changes in the Earth's rotation and gravitational field that have been closely monitored by modern space geodetic techniques. We compute the effect of 88 major reservoirs on length-of-day, polar motion, and low-degree gravitational coefficients. On an individual basis much smaller than geophysical signals in scale and magnitude, these anthropogenic effects prove to be non-negligible cumulatively, especially when considering the fact that our results represent underestimates of the reality. In particular, reservoir water has contributed a significant fraction in the total observed polar drift over the last 40 years. RP Chao, BF (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,GREENBELT,MD 20771, USA. RI Chao, Benjamin Fong/N-6156-2013 NR 13 TC 37 Z9 40 U1 2 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 1995 VL 22 IS 24 BP 3529 EP 3532 DI 10.1029/95GL02664 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TM728 UT WOS:A1995TM72800025 ER PT J AU Hide, R AF Hide, R TI The topographic torque on a bounding surface of a rotating gravitating fluid and the excitation by core motions of decadal fluctuations in the Earth's rotation - Reply SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article C1 CALTECH,JET PROP LAB,SPACE GEODET SCI & APPLICAT GRP,PASADENA,CA 91109. NR 8 TC 4 Z9 4 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 15 PY 1995 VL 22 IS 24 BP 3563 EP 3565 DI 10.1029/95GL03678 PG 3 WC Geosciences, Multidisciplinary SC Geology GA TM728 UT WOS:A1995TM72800034 ER PT J AU Luo, S Luo, W Clewley, JD Flanagan, TB Wade, LA AF Luo, S Luo, W Clewley, JD Flanagan, TB Wade, LA TI Thermodynamic studies of the LaNi5-xSnx-H system from x=O to 0.5 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal-Hydrogen Systems - Fundamentals and Applications CY NOV 06-11, 1994 CL FUJIYOSHIDA SHI, JAPAN DE LaNi5-xSnx-H system; intermetallic-hydrogen system; thermodynamics; gas solid system ID ABSORPTION; HYDROGEN; LANI5 AB Hydrogen isotherms have been measured for the ternary intermetallic system LaNi5-xSnx-H with x = 0, 0.10, 0.20, 0.25, 0.32, 0.40 and 0.50 at a series of temperatures from 300 to 423 K. The plateau pressures decrease with increase in x. The magnitudes of the enthalpy for the plateau reaction, as determined from the van't Hoff plots, increase steadily with x while the corresponding entropies are nearly constant. Thus the observed decrease in the plateau pressures can be attributed to the changes in Delta H-plat with x. The extent of the two-phase plateau regions decrease with x and hysteresis also decreases, nearly vanishing at x = 0.5. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Luo, S (reprint author), UNIV VERMONT,DEPT CHEM,BURLINGTON,VT 05405, USA. NR 15 TC 50 Z9 50 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD DEC 15 PY 1995 VL 231 IS 1-2 BP 467 EP 472 DI 10.1016/0925-8388(95)01871-9 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA TQ536 UT WOS:A1995TQ53600086 ER PT J AU Cantrell, JS Bowman, RC Wade, LA Luo, S Clewley, JD Flanagan, TB AF Cantrell, JS Bowman, RC Wade, LA Luo, S Clewley, JD Flanagan, TB TI Thermodynamic properties and the degradation of ZrNiHx at elevated temperatures SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal-Hydrogen Systems - Fundamentals and Applications CY NOV 06-11, 1994 CL FUJIYOSHIDA SHI, JAPAN DE thermodynamic properties; degradation; ZrNiHx ID HYDROGEN ISOTOPES; HYDRIDES; ALLOYS AB The hydrogen absorption and desorption behavior of ZrNi was measured over the temperature range from 525 K to 700 K. The isotherms demonstrate that the (beta + gamma) two-phase region extends to these temperatures, in contrast to a recently published phase diagram. The hysteresis ratio of the absorption to desorption plateau pressures decreases with temperature and approaches unity just above 700 K. The pressure-composition data were reproducible, even at temperatures greater than 680 K, provided the isotherm measurements were completed within a few hours. If the hydrided ZrNiHx sample was held above 680 K for more extended periods? significant changes in the pressure and isotherms were observed, The extent of these changes is dependent on both the temperature and hydrogen content. Only minor changes were seen after 24 h at 700 K for x < 1.3, but the degradation as reflected by the isotherms was substantial above 680 K for x > 1.5. X-ray diffraction studies of several ZrNiHx samples revealed that the degradation in the isotherms can be attributed to the formation of ZrHx and Ni via disproportionation. C1 AEROJET ELECTR SYST,AZUSA,CA 91702. CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV VERMONT,DEPT CHEM,BURLINGTON,VT 05405. RP Cantrell, JS (reprint author), MIAMI UNIV,DEPT CHEM,OXFORD,OH 45056, USA. OI Bowman, Robert/0000-0002-2114-1713 NR 20 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD DEC 15 PY 1995 VL 231 IS 1-2 BP 518 EP 523 DI 10.1016/0925-8388(95)01861-1 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA TQ536 UT WOS:A1995TQ53600096 ER PT J AU ZULIANI, P DELZOPPO, M CASTIGLIONI, C ZERBI, G MARDER, SR PERRY, JW AF ZULIANI, P DELZOPPO, M CASTIGLIONI, C ZERBI, G MARDER, SR PERRY, JW TI SOLVENT EFFECTS ON FIRST-ORDER MOLECULAR HYPERPOLARIZABILITY - A STUDY BASED ON VIBRATIONAL OBSERVABLES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONJUGATED ORGANIC-MOLECULES; BOND-LENGTH ALTERNATION; ELECTRONIC HYPERPOLARIZABILITY; INTENSITIES; FIELDS AB Using a recently developed method, we show here that solvent effects on the first molecular hyperpolarizabilities of push-pull polyenes can be predicted by evaluation of the relaxation contribution beta(r) to the hyperpolarizability from vibrational infrared and Raman intensities and vibrational frequencies. The molecules studied in this work are a few organic polymethine dyes with different donor and acceptor groups. The analysis of their vibrational spectra confirms the key role played by the structural parameters of the polyene chain in determining the nonlinear optical response. (C) 1995 American Institute of Physics. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. CALTECH,BECKMAN INST,PASADENA,CA 91125. RP ZULIANI, P (reprint author), POLITECN MILAN,DIPARTIMENTO CHIM IND & INGN CHIM,PL DA VINCI 32,I-20133 MILAN,ITALY. RI Perry, Joseph/B-7191-2011; Del Zoppo, Mirella/B-3686-2014; OI Perry, Joseph/0000-0003-1101-7337; Del Zoppo, Mirella/0000-0003-3639-2176; CASTIGLIONI, CHIARA/0000-0002-6945-9157 NR 28 TC 74 Z9 74 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1995 VL 103 IS 23 BP 9935 EP 9940 DI 10.1063/1.469882 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TK564 UT WOS:A1995TK56400005 ER PT J AU Hooker, SB Brown, JW Kirwan, AD Lindemann, GJ Mied, RP AF Hooker, SB Brown, JW Kirwan, AD Lindemann, GJ Mied, RP TI Kinematics of a warm-core dipole ring SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID COASTAL TRANSITION ZONE; WESTERN GULF; GEOSTROPHIC VORTICES; EDDY INTERACTION; OCEAN JET; EVOLUTION; EDDIES; VORTEX; MEXICO; INSTABILITY AB The remote sensing and in situ data used by Hooker and Brown [1994] to establish the dipole identity of warm core ring (WCR) 82-B is reexamined. It is found that a rotating barotropic modon [Mied er al., 1992] can be constructed with the same dipole rotation rate, center-to-center vortex separation distance, and peak anticyclonic vorticity as those of WCR 82-B. The model-derived velocity field is used to deform an array of material lines during a rotation period when the dipole is evident in the imagery and agreement between the model and the imagery is good. Specifically, it is observed that at the end of the imaging period, the surface tracer assumes a skewed dipole appearance, in which the line of centers is not perpendicular to the separatrix. Moreover, the separatrix morphology is qualitatively reproduced. Finally, the cyclone assumes an axisymmetric form. An attempt to derive qualitatively similar signatures using only monopole forcing yields results dissimilar from both the advanced very high resolution radiometer imagery and those obtained with the dipole, further confirming the underlying dipole character of WCR 82-B. C1 UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, MIAMI, FL 33149 USA. OLD DOMINION UNIV, NORFOLK, VA 23508 USA. USN, RES LAB, DIV REMOTE SENSING, WASHINGTON, DC 20375 USA. RP NASA, GODDARD SPACE FLIGHT CTR, HYDROSPHER PROC LAB, OCEANS & ICE BRANCH, CODE 971, GREENBELT, MD 20771 USA. RI Hooker, Stanford/E-2162-2012 NR 48 TC 17 Z9 17 U1 1 U2 3 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 DEC 15 PY 1995 VL 100 IS C12 BP 24797 EP 24809 DI 10.1029/95JC02900 PG 13 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100008 ER PT J AU Hoge, FE Williams, ME Swift, RN Yungel, JK Vodacek, A AF Hoge, FE Williams, ME Swift, RN Yungel, JK Vodacek, A TI Satellite retrieval of the absorption coefficient of chromophoric dissolved organic matter in continental margins SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID PASSIVE CORRELATION SPECTROSCOPY; OCEAN COLOR MEASUREMENT; WARM CORE RING; PHYTOPLANKTON; MODEL; WATERS; PIGMENTS; SEA AB The absorption coefficient of chromophoric dissolved organic matter at 443 nm, alpha(CDOM)(443), has been retrieved from coastal zone color scanner (CZCS) normalized water-leaving radiances. For a wintertime, low-chlorophyll condition in the Middle Atlantic Eight the alpha(CDOM)(443) is computed by mathematical inversion of an oceanic spectral radiance model, The CZCS alpha(CDOM)(443) retrieval is validated by a recent ship-aircraft alpha(CDOM)(443) retrieval experiment within the same oceanographic region. C1 UNIV MARYLAND, DEPT CHEM & BIOCHEM, COLLEGE PK, MD 20742 USA. EG&G IDAHO INC, WALLOPS FLIGHT FACIL, WALLOPS ISL, VA 23337 USA. RP NASA, GODDARD SPACE FLIGHT CTR, WALLOPS FLIGHT FACIL, BLDG N-159, WALLOPS ISL, VA 23337 USA. RI Vodacek, Anthony/F-1585-2011 OI Vodacek, Anthony/0000-0001-9196-0928 NR 29 TC 31 Z9 34 U1 1 U2 2 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 DEC 15 PY 1995 VL 100 IS C12 BP 24847 EP 24854 DI 10.1029/95JC02561 PG 8 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100013 ER PT J AU Fu, LL Davidson, RA AF Fu, LL Davidson, RA TI A note on the barotropic response of sea level to time-dependent wind forcing SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID DRIVEN CURRENT FLUCTUATIONS; DEEP OCEAN CURRENTS; ROSSBY WAVES; NORTH-ATLANTIC; ALTIMETER DATA; PACIFIC AB This study examines the extent to which sea level variations at periods between 30 days and 1 year and spatial scales greater than 1000 km can be described by the wind-driven linear barotropic vorticity dynamics. The TOPEX/POSEIDON altimetric observations of sea level and the wind products of the National Meteorological Center are used as the database for the study. Each term of the linear barotropic vorticity equation was evaluated by averaging over regions of 10 degrees x 10 degrees. In most of the open ocean the result of the analysis suggests that the sea level variabilities at the scales considered cannot be fully described by the equation; the apparent net vorticity change is more than what can be explained by the local wind stress curl. In the few regions where the wind stress curl is strong enough to balance the vorticity budget, predominantly in the northeast Pacific and the southeast Pacific, the balance is basically achieved in terms of the time-dependent topographic Sverdrup relation, namely, the balance between the advection of the planetary vorticity plus the topography-induced vorticity and the forcing by the wind stress curl. RP Fu, LL (reprint author), CALTECH,JET PROP LAB,MAIL STOP 300-323,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 33 TC 50 Z9 50 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1995 VL 100 IS C12 BP 24955 EP 24963 DI 10.1029/95JC02259 PG 9 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100023 ER PT J AU Chao, Y Fu, LL AF Chao, Y Fu, LL TI A comparison between the TOPEX/POSEIDON data and a global ocean general circulation model during 1992-1993 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SURFACE HEIGHT VARIABILITY; SEA-LEVEL; TROPICAL PACIFIC; GEOSAT ALTIMETRY; NORTH PACIFIC; INDIAN-OCEAN; WIND-STRESS; OSCILLATIONS; ATLANTIC; TIDES AB The TOPEX/POSEIDON altimetric sea level observation during 1992-1993 was used to validate the simulation made by a global ocean general circulation model (OGCM) forced by the daily wind stress and heat flux derived from the National Meteorological Center operational analysis. The OGCM is a version of the modular ocean model with a horizontal resolution of 2 degrees longitude and 1 degrees latitude and 22 levels in the vertical. The model simulation is compared to the observation at spatial scales of the order of 500 km and larger. Only the temporal variations are examined. The variability is composed primarily of the annual cycle and intraseasonal fluctuations (periods shorter than 100 days). The basic features of the annual cycle are simulated well by the model. Major discrepancies are found in the eastern tropical Pacific, as well as the eastern North Pacific and most of the interior of the North Atlantic. The culprit is suspected to be the inadequate heat forcing and mixing parameterizations of the model. Significant intraseasonal variability is found in the central North Pacific and the Southern Ocean. The simulation is highly correlated with the observation at periods from 20 to 100 days. The spatial scales are larger than 1000 km in many places. These variabilities are apparently the barotropic response of the ocean to wind forcing. The results of the study provide a basis for future assimilation of the data into the OGCM for improved description of the large-scale ocean variabilities. RP Chao, Y (reprint author), CALTECH,JET PROP LAB,MS 300-323,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 41 TC 57 Z9 60 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1995 VL 100 IS C12 BP 24965 EP 24976 DI 10.1029/95JC02260 PG 12 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100024 ER PT J AU Fukumori, I AF Fukumori, I TI Assimilation of TOPEX sea level measurements with a reduced-gravity, shallow water model of the tropical Pacific Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID EL-NINO; GEOSAT; TIDES AB Sea surface height variability measured by TOPEX is analyzed in the tropical Pacific Ocean by way of assimilation into a wind-driven, reduced-gravity, shallow water model using an approximate Kalman filter and smoother. The analysis results in an optimal fit of the dynamic model to the observations, providing a dynamically consistent interpolation of sea level and estimation of the circulation. Nearly 80% of the expected signal variance is accounted for by the model within 20 degrees of the equator, and estimation uncertainty is substantially reduced by the voluminous observation. Notable features resolved by the analysis include seasonal changes associated with the North Equatorial Countercurrent and equatorial Kelvin and Rossby waves. Significant discrepancies are also found between the estimate and TOPEX measurements, especially near the eastern boundary. Improvements in the estimate made by the assimilation are validated by comparisons with independent tide gauge and current meter observations. The employed filter and smoother are based on approximately computed estimation error covariance matrices, utilizing a spatial transformation and an asymptotic approximation. The analysis demonstrates the practical utility of a quasi-optimal filter and smoother. RP Fukumori, I (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 300-323,PASADENA,CA 91109, USA. NR 22 TC 51 Z9 53 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1995 VL 100 IS C12 BP 25027 EP 25039 DI 10.1029/95JC02083 PG 13 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100029 ER PT J AU Boulanger, JP Menkes, C AF Boulanger, JP Menkes, C TI Propagation and reflection of long equatorial waves in the Pacific Ocean during the 1992-1993 El Nino SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SURFACE-CURRENT ANOMALIES; TROPICAL PACIFIC; GLOBAL CLIMATE; ROSSBY WAVES; SEA-LEVEL; SOUTHERN OSCILLATION; ENSO; ATMOSPHERE; MODEL; WIND AB The TOPES/POSEIDON satellite, together with the Tropical Ocean and Global Atmosphere-Tropical Atmosphere Ocean (TOGA-TAO) array, provides oceanographic and atmospheric observations which allow a detailed study of the equatorial Pacific variability. During the November 1992 to December 1993 El Nino period, sea level, dynamic height, wind stress, sea surface temperature, and surface zonal current data derived from TOPEX/POSEIDON and TOGA-TAO measurements were used to describe the Pacific ocean-atmosphere system and to understand the role played by long equatorial waves. A potentially important mechanism of the El Nino-Southern Oscillation (ENSO), commonly referred to as the delayed action oscillator, involves Kelvin and long Rossby waves and their reflections at the Pacific western boundary. In order to investigate if this process was at work during the period under study, a method for projecting TOPEX sea level, TOGA-TAO dynamic height, and zonal wind stress onto meridional wave structures was designed both in unbounded and bounded regions, The Kelvin and first three Rossby waves of the first baroclinic mode are propagating at theoretical wave speeds in all data sets, Zonal wind stress projections show that oceanic propagating wave features are strongly linked to wind variability. Reflections are then examined at both boundaries. At the eastern boundary most of the signal reflected from incoming Kelvin waves is either counteracted by unfavorable wind forcing or strongly reinforced and therefore does not Seem to play a significant role for generating the major Rossby wave signals during the period under study, In the western Pacific, wind forcing, rather than western boundary reflections, appears to be the main trigger for returning Kelvin waves from the western Pacific to the eastern Pacific. Simultaneously with the weakening of the extended 1991-1993 ENSO event, an upwelling Kelvin wave is observed propagating from the western Pacific in September 1993 to the eastern Pacific in November 1993. This scenario is consistent with some features of the delayed action oscillator mechanism, where an upwelling Kelvin wave is systematically seen returning from the western boundary to the east at the end of warm events. However, here, contrary to the delayed action oscillator, most of this returning Kelvin wave seems to be forced by a strong easterly anomaly located in the western Pacific, rather than by reflection of an upwelling first Rossby wave at the western boundary. C1 ORSTOM,SURTROPAC GRP,NOUMEA,NEW CALEDONIA. UNIV SPACE RES ASSOC,GODDARD SPACE FLIGHT CTR,HYDORSPHER PROC LAB,GREENBELT,MD. RP Boulanger, JP (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 300-323,PASADENA,CA 91109, USA. RI menkes, christophe/H-9085-2016 OI menkes, christophe/0000-0002-1457-9696 NR 47 TC 90 Z9 91 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1995 VL 100 IS C12 BP 25041 EP 25059 DI 10.1029/95JC02956 PG 19 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100030 ER PT J AU Menkes, C Boulanger, JP Busalacchi, AJ AF Menkes, C Boulanger, JP Busalacchi, AJ TI Evaluation of TOPEX and basin-wide tropical ocean and global atmosphere-tropical atmosphere ocean sea surface topographies and derived geostrophic currents SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ZONAL CURRENTS; PACIFIC; TRANSPORTS; EQUATOR; GEOSAT AB Fields of TOPEX-derived sea level anomalies are validated against and compared with fields of Tropical Ocean and Global Atmosphere-Tropical Atmosphere Ocean (TOGA-TAO) dynamic height anomalies for the first 470 days of the TOPEX/POSEIDON mission. At periods longer than 35 days, TOPEX sea level anomalies compare extremely well with TOGA-TAO dynamic height anomalies throughout the whole basin, with a mean correlation of 0.79 and mean rms differences of 2.6 cm. Zonal geostrophic current anomalies are then derived from both data sets and validated against in situ current meter measurements at the equator. TOPEX-derived geostrophic current anomalies at the equator are in good agreement with in situ currents at 0 degrees-165 degrees E, 0 degrees-170 degrees W, 0 degrees-140 degrees W, and 0 degrees-170 degrees W. TOGA-TAO-derived current anomalies compare well with in situ currents at 0 degrees-110 degrees W, 0 degrees-140 degrees W, and 0 degrees-170 degrees W, but poor comparisons at 0 degrees-165 degrees E are thought to be linked to the absence of instantaneous salinity measurements in the dynamic height calculation. Despite localized discrepancies, basin-wide TOGA-TAO geostrophic currents compare reasonably well with TOPEX-derived geostrophic currents. The discrepancies in the comparison between TOPEX and TAO are shown to be mostly associated with gaps in TOGA-TAO space-time sampling and subsequent gridding procedures. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NASA,GODDARD SPACE FLIGHT CTR,HYDROSPHER PROC LAB,GREENBELT,MD 20771. UNIV PARIS 06,OCEAN DYNAM & CLIMATOL LAB,ORSTOM,CNRS,UNITE MIXTE RECH,PARIS,FRANCE. RI menkes, christophe/H-9085-2016 OI menkes, christophe/0000-0002-1457-9696 NR 24 TC 27 Z9 27 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1995 VL 100 IS C12 BP 25087 EP 25099 DI 10.1029/95JC03026 PG 13 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100033 ER PT J AU Katz, EJ Busalacchi, A Bushnell, M Gonzalez, F Gourdeau, L McPhaden, M Picaut, J AF Katz, EJ Busalacchi, A Bushnell, M Gonzalez, F Gourdeau, L McPhaden, M Picaut, J TI A comparison of coincidental time series of the ocean surface height by satellite altimeter, mooring, and inverted echo sounder SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ATLANTIC; GEOSAT AB Altimetric measurements of sea surface height at two locations in the western tropical Pacific Ocean are compared to estimates of the dynamic sea surface height computed from cotemporal surface-to-bottom temperature/salinity measurements on moorings and acoustic travel time measured by bottom-moored inverted echo sounders. The results show statistically high correlation between the in situ measurements at periods greater than 5 days and between the altimeter and in situ measurements at periods greater than 20 days. The rms difference between any two modes of observation is consistently between 2 and 3 cm. C1 NASA,GODDARD SPACE FLIGHT CTR,HYDROSPHER PROC LAB,GREENBELT,MD 20771. NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. ORSTOM,SURTROPAC GRP,NOUMEA,NEW CALEDONIA. RP Katz, EJ (reprint author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,POB 1000,PALISADES,NY 10964, USA. RI McPhaden, Michael/D-9799-2016 NR 11 TC 18 Z9 18 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1995 VL 100 IS C12 BP 25101 EP 25108 DI 10.1029/95JC01959 PG 8 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100034 ER PT J AU Picaut, J Busalacchi, AJ McPhaden, MJ Gourdeau, L Gonzalez, FI Hackert, EC AF Picaut, J Busalacchi, AJ McPhaden, MJ Gourdeau, L Gonzalez, FI Hackert, EC TI Open-ocean validation of TOPEX/POSEIDON sea level in the western equatorial Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID TROPICAL PACIFIC; ZONAL CURRENTS; ROSSBY WAVES; TIDES; KELVIN; MODEL; WIND AB During the verification phase of the TOPEX/POSEIDON radar altimeter mission a rigorous open-ocean validation experiment was conducted in the western equatorial Pacific Ocean. From August-September 1992 to February-March 1993, two Tropical Ocean and Global Atmosphere (TOGA) Tropical Atmosphere Ocean moorings at 2 degrees S-156 degrees E (1739 m depth) and 2 degrees S-164.4 degrees E (4400 m depth) were outfitted with additional temperature, salinity, and pressure sensors to measure precisely the dynamic height from the surface to the bottom at 5-min intervals directly beneath two TOPEX/POSEIDON crossovers. Bottom pressure gauges and inverted echo sounders were deployed as well. A predeployment design study using full depth conductivity-temperature-depth casts, subsequently confirmed by postdeployment analyses, indicated this suite of instruments was capable of measuring sea surface height fluctuations to within 1-2 cm. The validation experiment also benefited from the comprehensive set of ocean-atmosphere measurements that were made in the region during the TOGA Coupled Ocean-Atmosphere Response Experiment intensive observation period of November 1992 to February 1993. The surface relative to bottom dynamic height fluctuations observed in situ during the 6-7 month experiment had a standard deviation of 5 cm with excursions of order +/- 15 cm. Energetic steric sea level variability was found to exist on short timescales of order hours to a few days, most notably, the quasi-permanence of strong semidiurnal internal tides. Such internal tides were noted to induce changes in surface dynamic height with a standard deviation of 2 dynamic centimeters. At the shallower of the two sites, 2 degrees S-156 degrees E, a possible nonlinear rectification of the internal tide was observed occasionally to change the dynamic height by as much as 30 cm over less than an hour. On timescales longer than the 10-day repeat of the TOPEX/POSEIDON satellite, the low-frequency fluctuations of dynamic height were related to interannual variations corresponding to the 1991-1993 El Nino-Southern Oscillation, to the seasonal cycle, and to intraseasonal variations associated with the 40- to 60-day oscillations of the equatorial zonal wind field. Instantaneous comparisons between the 1-s TOPEX/POSEIDON altimeter retrievals and the 5-min dynamic height were performed with regard to several tide models, the barotropic tide measured in situ, European Centre for Medium-Range Weather Forecasts surface air pressure, and the surface air pressure measured in situ. Depending on the choice of altimeter and of the environmental corrections applied to the altimeter data, the rms differences between the satellite and the in situ measurements of sea level were as low as 3.3 cm at 2 degrees S-156 degrees E and 3.7 cm at 2 degrees S-164.4 degrees E. When additional satellite data in the general vicinity of the mooring are included and after the use of a 30-day low-pass filter, the satellite and in situ data were found to be highly correlated, with correlation coefficients of about 0.95 and rms differences around 1.8 cm. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. HUGHES STX CORP,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,HYDROSPHER PROC LAB,GREENBELT,MD 20771. RP Picaut, J (reprint author), ORSTOM,SURTROPAC GRP,BP 5,NOUMEA,NEW CALEDONIA. RI Hackert, Eric/A-9915-2011; McPhaden, Michael/D-9799-2016 NR 43 TC 32 Z9 32 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1995 VL 100 IS C12 BP 25109 EP 25127 DI 10.1029/95JC02128 PG 19 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100035 ER PT J AU Nerem, RS AF Nerem, RS TI Measuring global mean sea level variations using TOPEX/POSEIDON altimeter data SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID GREENLAND ICE-SHEET; OCEAN; RISE; VARIABILITY AB The variations of global mean sea level are an important indicator of global climate change, and their measurement can provide important information for determining the socioeconomic impact of sea level change on coastal land use. The analysis of historical tide gauge records generally indicates that sea level has risen at a rate of about 2 mm/yr during the last 100 years; however, this estimate is somewhat uncertain due to the effects of regional crustal motion, lack of uniform temporal coverage, and the limited spatial sampling of tide gauges. The prospect of measuring variations in global mean sea level has been assessed using approximately 2.5 years of satellite altimeter data from the TOPEX/POSEIDON (T/P) mission, where synoptic mapping of the geocentric height of the ocean surface is routinely achieved with a point-to-point accuracy of better than 5 cm. The global mean sea level variations measured by T/P every 10 days have an rms of 6 mm (4 mm after detrending), some of which is shown to be correlated with sea surface temperature variations. The rate of change of global mean sea level derived from 2.5 years of data is +5.8 mm/yr with a scatter of 0.7 mm/yr. Currently, it is impossible to accurately estimate the error in the measured rate of sea level rise, since little is known about the long-term behavior of the measurement errors at the millimeter level. In addition, there is evidence from the sea surface temperature record that the measured rate of sea level rise is associated with a relatively short-term (interannual) variation unrelated to the long-term signal expected from global warming. Nevertheless, these results suggest that T/P is achieving the necessary repeatability to measure global sea level variations caused by climate change, and a longer time series will significantly improve the sea level rise estimate by averaging measurement error and real sea level variations. A longer time series will also reduce the errors in estimates of the altimeter calibration, providing an important constraint on any long-term instrument drift. Future research will focus on establishing a realistic error budget for these measurements of global mean sea level, so that they can be put in the proper context with other observations of global climate change. RP NASA, GODDARD SPACE FLIGHT CTR, SPACE GEODESY BRANCH, CODE 926, GREENBELT, MD 20771 USA. NR 79 TC 50 Z9 58 U1 2 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 DEC 15 PY 1995 VL 100 IS C12 BP 25135 EP 25151 DI 10.1029/95JC02303 PG 17 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100037 ER PT J AU Sanchez, BV Pavlis, NK AF Sanchez, BV Pavlis, NK TI Estimation of main tidal constituents from TOPEX altimetry using a Proudman function expansion SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID GLOBAL OCEAN TIDES; GEOSAT ALTIMETRY; SEA AB Tidal models for the main diurnal and semidiurnal constituents have been computed from TOPEX altimeter data and a set of Proudman functions computed numerically in the space defined by the ocean basins. The accurate modeling of the ocean tides is necessary in order to interpret the height measurements of the ocean surface obtained from satellite altimeters. It is also an interesting dynamical problem in its own right. The surface height field due to any tidal constituent can be expanded in terms of the eigenfunctions of the velocity potential (Proudman functions) with coefficients estimated in a least squares sense from a field of discrete data points obtained from altimetry, tide gauges, bottom pressure sensors, etc. The Proudman functions constitute a mass conserving orthogonal basis; their computation does not require any assumption concerning friction or energy dissipation, only a numerical grid expressing the shape of coastline and the bathymetry of the ocean basins. They have the space structure of standing waves and can be identified as the zero-rotation gravitational normal modes. They have to be evaluated numerically only once for each particular grid resolution. In this investigation the Proudman functions were computed by means of finite differences in spherical coordinates over a 2 degrees x2 degrees grid covering most of the world's oceans for a total of 8608 degrees of freedom. The data field used in this study consists of approximately 15 months of TOPEX altimetry in the form of collinear differences. Results for the major semidiurnal and diurnal constituents (M(2), S-2, N-2, K-2, K-1, O-1, P-1, and Q(1)) have been obtained in terms of corrections to a priori values obtained by fitting Schwiderski's (1980) models. The new models (Goddard Space Flight Center (GSFC94A)) are tested at a set of ''ground truth'' data points. These tests indicate substantial improvement for most of the constituents as compared with Schwiderski's solutions. Use of GSFC94A results in a 7.8-cm reduction in the rms overlap difference of 15.5 cm. The GSFC94A model yielded a mean rms sea surface variability of 7.9 cm, compared with the 9.4 cm obtained when using Schwiderski's model. C1 HUGHES STX CORP,GREENBELT,MD 20770. RP Sanchez, BV (reprint author), NASA,GODDARD SPACE FLIGHT CTR,SPACE GEODESY BRANCH,CODE 926,GREENBELT,MD 20771, USA. RI Sanchez, Braulio/I-5952-2013 NR 32 TC 10 Z9 11 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1995 VL 100 IS C12 BP 25229 EP 25248 DI 10.1029/95JC02082 PG 20 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100042 ER PT J AU Marshall, JA Zelensky, NP Klosko, SM Chinn, DS Luthcke, SB Rachlin, KE Williamson, RG AF Marshall, JA Zelensky, NP Klosko, SM Chinn, DS Luthcke, SB Rachlin, KE Williamson, RG TI The temporal and spatial characteristics of TOPEX/POSEIDON radial orbit error SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID GLOBAL POSITIONING SYSTEM; SEASAT ALTIMETER DATA; GRAVITATIONAL MODEL; EARTH; PERTURBATIONS; SATELLITES; TRACKING AB Satellite orbit error has long been the bane of oceanographers who analyze altimetry data. However, radial orbit error on TOPEX/POSEIDON (T/P) has been reduced to the 3 to 4-cm root-mean-square (rms) level over a 10-day repeat cycle, which represents an order of magnitude improvement over earlier altimetry missions such as Geosat. Consequently, oceanographers are now able to directly evaluate the absolute ocean topography to unprecedented accuracy levels. While significantly reduced, the T/P orbit error still requires quantification. This study examines the spatial and temporal characteristics of the T/P radial orbit error, as assessed through the analysis of laser tracking residuals and orbit comparisons with independently generated trajectories. Spectral analyses of the orbit differences between the orbits determined from satellite laser ranging and Doppler Orbitography and Radiopositioning Integrated by Satellite data and the independently determined reduced dynamic Global Positioning System (GPS) ephemerides indicate that the predominant power is at the once-per-orbital revolution frequency with 2- to 3-cm peaks. When the orbit differences are colinearly aligned to a fixed geographic grid and spectral analysis is performed at each geographic grid point, a nearly 60-day period is found with maximum amplitudes in the 2- to 4-cm range. The contribution of both conservative and nonconservative force and measurement mismodeling to this error signal are assessed. We demonstrate that the similar to 60-day error period seen at fixed geographic locations arises from weaknesses in the dynamic ocean tidal models used in the orbit calculations. New tidal models have been developed which significantly reduce this error. Second-generation orbits incorporating many model improvements have been computed and demonstrate a significant reduction in the radial orbit error signals. Some orbit error still exists, and methods for further model improvements and the possibility of achieving 1-cm radial rms orbit accuracy in T/P are discussed. C1 HUGHES STX CORP,GREENBELT,MD 20770. RP Marshall, JA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,SPACE GEODESY BRANCH,CODE 926,GREENBELT,MD 20771, USA. RI Luthcke, Scott/D-6283-2012 NR 54 TC 68 Z9 69 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 15 PY 1995 VL 100 IS C12 BP 25331 EP 25352 DI 10.1029/95JC01845 PG 22 WC Oceanography SC Oceanography GA TL341 UT WOS:A1995TL34100048 ER PT J AU Whittenberger, JD Kumar, KS Dipietro, MS Brown, SA AF Whittenberger, JD Kumar, KS Dipietro, MS Brown, SA TI Elevated temperature deformation of several quaternary L1(2)Al(3)Ti based alloys reinforced with TiB2 particles SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID COMPRESSION BEHAVIOR; AL66TI25MN9; COMPOSITES; TRIALUMINIDES; AL67TI25CR8 AB Concurrent with an investigation of quaternary cast and forged L1(2) modified Al-3 Ti's containing 9 at% Cr, Fe and/or Mn, a similar series of four alloys was produced via XD(TM) technology, whereby 20 vol% of similar to 0.5 mu m TiB2 particles was incorporated as a reinforcement. Following densification by hot pressing and slow isothermal forging, small diameter compression test samples were machined from each compact and tested. The 0.2% yield strength measurements revealed a strength advantage for the particulate reinforced materials over the unreinforced ingot metallurgy matrices to about 1175 K. Furthermore, 900 and 1100 K constant velocity testing indicated that the TiB2 containing materials were stronger than the ingot metallurgy matrices down to strain rates of similar to 10(-7)s(-1). None of the quaternary L1(2) alloys + 20 TiB2 consistently displayed a strength advantage over others. However, extrapolation of the present mechanical property data into slower strain regimes indicated that the composites will not possess any strength advantage over the unreinforced versions. Such losses in strength appeared to be caused by small grains in the particulate reinforced alloys, which promoted grain boundary weakening mechanisms. C1 MARTIN MARIETTA CORP LABS,BALTIMORE,MD 21227. RP Whittenberger, JD (reprint author), NASA,LEWIS RES CTR,21000 BROOKPARK RD,CLEVELAND,OH 44135, USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD DEC 15 PY 1995 VL 30 IS 24 BP 6309 EP 6315 DI 10.1007/BF00369682 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA TM964 UT WOS:A1995TM96400025 ER PT J AU Stompor, R Gorski, KM Banday, AJ AF Stompor, R Gorski, KM Banday, AJ TI COBE-DMR normalization for inflationary flat dark matter models SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE cosmic microwave background; dark matter; cosmology, observations; large-scale structure of Universe ID DIFFERENTIAL MICROWAVE RADIOMETER; LARGE-SCALE STRUCTURE; COSMOLOGICAL CONSTANT; POWER SPECTRUM; REDSHIFT SPACE; GALAXIES; UNIVERSE; ANISOTROPY; GAS AB The two-year COBE-DMR 53- and 90-GHz sky maps, in both galactic and ecliptic coordinates, are used to determine the normalization of inflationary universe models with a flat global geometry and adiabatic density perturbations. The appropriately normalized cold dark matter (CDM) and mixed dark matter (MDM) models and cosmological-constant-dominated CDM models, computed for a range of values of Omega(b) and h, are then compared to various measures of structure in the universe. Critical density CDM models appear to be irreconcilable with observations on both large and small scales simultaneously, whereas MDM models provide a somewhat better fit to the data. Although the COBE-DMR data alone prefer a nearly critical value for the total density, low-density cosmological constant models with Omega(0) greater than or equal to 0.15 cannot be rejected at a confidence level exceeding 95 per cent. Such models may also provide a significantly better fit to the matter distribution data than critical density CDM. C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. UNIV WARSAW OBSERV,PL-00478 WARSAW,POLAND. HUGHES STX CORP,LANHAM,MD 20706. RP Stompor, R (reprint author), COPENICUS ASTRON CTR,BARTYCKA 18,PL-00716 WARSAW,POLAND. NR 53 TC 50 Z9 50 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 15 PY 1995 VL 277 IS 4 BP 1225 EP 1234 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TL361 UT WOS:A1995TL36100004 ER PT J AU Sigl, G Jedamzik, K Schramm, DN Berezinsky, VS AF Sigl, G Jedamzik, K Schramm, DN Berezinsky, VS TI Helium photodisintegration and nucleosynthesis: Implications for topological defects, high energy cosmic rays, and massive black holes SO PHYSICAL REVIEW D LA English DT Article ID STRING EVOLUTION; PRIMORDIAL NUCLEOSYNTHESIS; SUPERCONDUCTING STRINGS; BACKGROUND-RADIATION; PARTICLES; ORIGIN; ANNIHILATION; UNIVERSE; EMISSION; MEV/C AB We consider the production of He-3 and H-2 by He-4 photodisintegration initiated by nonthermal energy releases during early cosmic epochs. We find that this process cannot be the predominant source of primordial H-2 since it would result in anomalously high He-3/D ratios in conflict with standard chemical evolution assumptions. We apply this fact to constrain topological defect models of highest energy cosmic ray (HECR) production. Such models have been proposed as possible sources of ultrahigh energy particles and gamma rays with energies above 10(20) eV. The constraints on these models derived from He-4 photodisintegration are compared to corresponding limits from spectral distortions of the cosmic microwave background radiation and from the observed diffuse gamma-ray background. It is shown that for reasonable primary particle injection spectra and within the models considered previously superconducting cosmic strings, unlike ordinary strings or annihilating monopoles, cannot produce the HECR flux at the present epoch without violating at least the He-4-photodisintegration bound. The constraint from the diffuse gamma-ray background rules out the dominant production of HECR by the decay of grand unification particles in models with cosmological evolution assuming standard fragmentation functions. Constraints on massive black hole induced photodisintegration are also discussed. C1 FERMILAB NATL ACCELERATOR LAB, NASA, FERMILAB ASTROPHYS CTR, BATAVIA, IL 60510 USA. UNIV CHICAGO, ENRICO FERMI INST, DEPT PHYS, CHICAGO, IL 60637 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. IST NAZL FIS NUCL, LAB NAZL GRAN SASSO, I-67010 ASSERGI, AQUILA, ITALY. RP UNIV CHICAGO, ENRICO FERMI INST, DEPT ASTRON & ASTROPHYS, CHICAGO, IL 60637 USA. NR 78 TC 76 Z9 76 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC 15 PY 1995 VL 52 IS 12 BP 6682 EP 6693 DI 10.1103/PhysRevD.52.6682 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA TN613 UT WOS:A1995TN61300006 ER PT J AU WEISSMAN, PR AF WEISSMAN, PR TI IMPACT JUPITER - THE CRASH OF COMET SHOEMAKER-LEVY-9 - LEVY,DH SO SCIENCE LA English DT Book Review RP WEISSMAN, PR (reprint author), CALTECH,JET PROP LAB,DIV EARTH & SPACE SCI,PASADENA,CA 91109, USA. NR 1 TC 0 Z9 0 U1 0 U2 3 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 15 PY 1995 VL 270 IS 5243 BP 1857 EP 1858 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TK476 UT WOS:A1995TK47600060 ER PT J AU WEISSMAN, PR AF WEISSMAN, PR TI THE GREAT COMET CRASH - THE IMPACT OF COMET SHOEMAKER-LEVY-9 ON JUPITER - SPENCER,JR, MITTON,J SO SCIENCE LA English DT Book Review RP WEISSMAN, PR (reprint author), CALTECH,JET PROP LAB,DIV EARTH & SPACE SCI,PASADENA,CA 91109, USA. NR 1 TC 0 Z9 0 U1 0 U2 3 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 15 PY 1995 VL 270 IS 5243 BP 1857 EP 1858 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TK476 UT WOS:A1995TK47600061 ER PT J AU BOZZOLO, G AMADOR, C FENANTE, J NOEBE, RD AF BOZZOLO, G AMADOR, C FENANTE, J NOEBE, RD TI MODELING OF THE DEFECT STRUCTURE OF BETA-NIAL SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID UNIVERSAL FEATURES; BINARY-ALLOYS; PARAMETERS; METALS C1 NATL AUTONOMOUS UNIV MEXICO, FAC QUIM, MEXICO CITY 04510, DF, MEXICO. NASA, LEWIS RES CTR, CLEVELAND, OH 44135 USA. RP ANALEX CORP, 3001 AEROSP PKWY, BROOKPARK, OH 44142 USA. RI Amador-Bedolla, Carlos/E-7448-2010 OI Amador-Bedolla, Carlos/0000-0001-9590-2645 NR 26 TC 25 Z9 25 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD DEC 15 PY 1995 VL 33 IS 12 BP 1907 EP 1913 DI 10.1016/0956-716X(95)00474-A PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA TE964 UT WOS:A1995TE96400005 ER PT J AU HOLLENBACH, D NATTA, A AF HOLLENBACH, D NATTA, A TI TIME-DEPENDENT PHOTODISSOCIATION REGIONS SO ASTROPHYSICAL JOURNAL LA English DT Article DE INFRARED, ISM, LINES AND BANDS; ISM, CLOUDS; ISM, MOLECULES; PLANETARY NEBULAE, GENERAL; ULTRAVIOLET, ISM ID MOLECULAR-HYDROGEN GAS; H-II REGIONS; PLANETARY-NEBULAE; ULTRAVIOLET-RADIATION; INFRARED-EMISSION; CLOUDS; SHOCKS AB We present theoretical models of the time-dependent thermal and chemical structure of molecular gas suddenly exposed to far-ultraviolet (FUV) (6 eV < hv < 13.6 eV) radiation fields and the consequent time-dependent infrared emission of the gas. We focus on the response of molecular hydrogen for cloud densities ranging from n = 10(3) to 10(6) cm(-3) and FUV fluxes G(0) = 10(3)-10(6) times the local FUV interstellar flux. For G(0)/n > 10(-2) cm(3), the emergent H-2 vibrational line intensities are initially larger than the final equilibrium values. The H-2 lines are excited by FUV fluorescence and by collisional excitation in warm gas. Most of the H-2 intensity is generated at a characteristic hydrogen column density of N similar to 10(21) cm(-2), which corresponds to an FUV optical depth of unity caused by dust opacity. The time dependence of the H-2 intensities arises because the initial abundances of H-2 at these depths is much higher than the equilibrium values, so that H-2 initially competes more effectively with dust in absorbing FUV photons. Considerable column densities of warm (T similar to 1000) K H-2 gas can be produced by the FUV pumping of H-2 vibrational levels followed by collisional de-excitation, which transfers the energy to heat. In dense (n greater than or similar to 10(5) cm(-3)) gas exposed to high (G(0) greater than or similar to 10(4)) fluxes, this warm gas produces a 2-1 S(1)/1-0 S(1) H-2 line ratio of similar to 0.1, which mimics the ratio found in shocked gas. In lower density regions, the FUV pumping produces a pure-fluorescent ratio of similar to 0.5. We also present calculations of the time dependence of the atomic hydrogen column densities and of the intensities of O I 6300 Angstrom, S II 6730 Angstrom, Fe II 1.64 mu m, and rotational OH and H2O emission. Potential applications include star-forming regions, clouds near active galactic nuclei, and planetary nebulae. We apply our models to five planetary nebulae and conclude that only BD +30 degrees 3639 shows evidence of enhanced H-2 emission due to (high) nonequilibrium H-2 abundances. C1 OSSERV ASTROFIS ARCETRI, I-50125 FLORENCE, ITALY. RP HOLLENBACH, D (reprint author), NASA, AMES RES CTR, MS 245-3, MOFFETT FIELD, CA 94035 USA. NR 30 TC 46 Z9 46 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1995 VL 455 IS 1 BP 133 EP 144 DI 10.1086/176562 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TG830 UT WOS:A1995TG83000014 ER PT J AU MORIARTYSCHIEVEN, GH WANNIER, PG MANGUM, JG TAMURA, M OLMSTED, VK AF MORIARTYSCHIEVEN, GH WANNIER, PG MANGUM, JG TAMURA, M OLMSTED, VK TI CIRCUM-PROTOSTELLAR ENVIRONMENTS .3. GAS DENSITIES AND KINETIC TEMPERATURES SO ASTROPHYSICAL JOURNAL LA English DT Article DE CIRCUMSTELLAR MATTER; ISM, JETS AND OUTFLOWS; ISM, KINEMATICS AND DYNAMICS; ISM, MOLECULES; STARS, PRE-MAIN SEQUENCE ID MOLECULAR CLOUDS; STAR FORMATION; DARK CLOUDS; ORION-KL; FORMALDEHYDE; CS; OUTFLOWS; COLLAPSE; TAURUS; B335 AB We have surveyed a complete, flux-limited, IRAS-selected sample of protostars in Taurus whose infrared through millimeter-wave properties indicate them to be younger than T Tauri stars. We have observed CS J = 3-2, 5-4, and 7-6, and H2CO J(K-1K+1) = 3(03)-2(02) and 3(22)-2(21), toward the central positions of all 25 objects. CS traces the dense gas in the circumstellar envelope, while H2CO probes the kinetic temperature of the dense gas. Only three of the sources were detected in both transitions of H2CO, making it of limited use as a temperature probe of these objects. Combining the CS- and H2CO-derived properties with those previously derived from dust continuum emission, we have placed limits on the temperatures of the envelopes, typically 20 K less than or similar to T-K less than or similar to 50 K. Derived envelope gas densities and CS column densities were typically a few x 10(6) cm(-3) and a few x 10(12) cm(-2), respectively. Where CS 5-4 was detected (roughly half of the observed sources), the derived envelope masses were consistent with those derived from dust emission (assuming a CS/H-2 abundance of 10(-8)). Since most of the embedded (i.e., not optically visible) sources were detected in CS 5-4, and most of the visible sources were not, this may mean either that the CS-emitting envelope has dissipated in the more evolved objects (confirming Ohashi et al. 1991), or CS has become depleted. L1551NE may have an asymmetric, double-peaked line profile like that of B335, suggestive of a collapsing envelope. L1551NE may be in transition from the much younger ''class 0'' protostar stage to the somewhat more evolved ''class I'' protostar stage. Several of the sources have broad CS line wings probably originating from dense gas in a molecular outflow. In at least one case, the kinetic temperature of the outflowing gas may be greater than that in the envelope. C1 JET PROP LAB,PASADENA,CA 91109. UNIV ARIZONA,STEWARD OBSERV,SUBMILLIMETER TELESCOPE OBSERV,TUCSON,AZ 85721. NATL ASTRON OBSERV,MITAKA,TOKYO 181,JAPAN. RP MORIARTYSCHIEVEN, GH (reprint author), NATL RES COUNCIL CANADA,DOMINION RADIO ASTROPHYS OBSERV,BOX 248,PENTICTON,BC V2A 6K3,CANADA. NR 32 TC 31 Z9 31 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1995 VL 455 IS 1 BP 190 EP 201 DI 10.1086/176567 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TG830 UT WOS:A1995TG83000019 ER PT J AU ASCHWANDEN, MJ BENZ, AO DENNIS, BR SCHWARTZ, RA AF ASCHWANDEN, MJ BENZ, AO DENNIS, BR SCHWARTZ, RA TI SOLAR ELECTRON-BEAMS DETECTED IN HARD X-RAYS AND RADIO-WAVES SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCELERATION OF PARTICLES; SUN, FLARES; SUN, PARTICLE EMISSION; SUN, RADIO RADIATION; SUN, X-RAYS, GAMMA RAYS ID ENERGETIC ELECTRONS; FLARE PARAMETERS; IMPULSIVE PHASE; BURSTS; SPECTROMETER; ACCELERATION; EMISSION AB We present a statistical survey of electron beam signatures that are detected simultaneously at hard X-ray (HXR) and radio wavelengths during solar flares. For the identification of a simultaneous event we require a type III (normal-drifting or reverse-slope-drifting) radio burst that coincides (within +/-1 s) with a significant (greater than or equal to 3 sigma) HXR pulse of similar duration (less than or equal to 1 s). Our survey covers all HXRBS/SMM and BATSE/CGRO flares that were simultaneously observed with the 0.1-1 GHz spectrometer Ikarus or the 0.1-3 GHz spectrometer Phoenix of ETH Zurich during 1980-1993. The major results and conclusions are as follows: 1. We identified 233 HXR pulses (out of 882) to be correlated with type III-like radio bursts: 77% with normal-drifting type III bursts, 34% with reverse-slope (RS)-drifting bursts, and 13% with oppositely drifting (III+RS) burst pairs. The majority of these cases provide evidence for acceleration of bidirectional electron beams. 2. The detailed correlation with type III-like radio bursts suggests that most of the subsecond fluctuations detectable in greater than or equal to 25 keV HXR emission are related to discrete electron injections. This is also supported by the proportionality of the HXR pulse duration with the radio burst duration. The distribution of HXR pulse durations w(x) is found to have an exponential distribution, i.e., N(w(x)) proportional to exp (-w(x)/0.25 s) in the measured range of w(x) approximate to 0.5-1.5 s. 3. From oppositely drifting radio burst pairs we infer electron densities of n(e) = 10(9)-10(10) cm(-3) at the acceleration site. From the absence of a frequency gap between the simultaneous start frequencies of upward and downward drifting radio bursts, we infer an upper limit of L less than or equal to 2000 km for the extent of the acceleration site and an acceleration time of At Delta t less than or equal to 3 ms for the (greater than or equal to 25 keV) radio-emitting electrons (in the case of parallel electric fields). 4. The relative timing between HXR pulses and radio bursts is best at the start frequency (of earliest radio detection), with a coincidence of less than or equal to 0.1 s in the statistical average, while the radio bursts are delayed at all other frequencies (in the statistical average). The timing is consistent with the scenario of electron injection at a mean coronal height of h approximate to 10(4) km. The radio-emitting electrons are found to have lower energies (greater than or equal to 5 keV) than the greater than or equal to 25 keV HXR-emitting electrons. 5. The modulated HXR flux that correlates with electron beam signatures in radio amounts to 2%-6% of the total HXR count rate (for BATSE flares). The associated kinetic energy in electrons is estimated to be E = 4 x 10(22)-10(27) ergs per beam, or N-e = 4 x 10(28)-10(33) electrons per beam, considering the spread from the smallest to the largest flare detected by HXRBS. 6. The average drift rate of propagating electron beams is found here to be \dv/dt\ = 0.10v(1.4) MHz s(-1) in the frequency range of v = 200-3000 MHg which is lower than expected from the Alvarez & Haddock relation for frequencies less than or equal to 550 MHz. 7. The frequency distributions of HXR fluxes (F-x) and radio type III burst fluxes (F-R), which both can be characterized by a power law, are found to have a significantly different slope, i.e., N(F-x) proportional to F-x(-1.87) versus N(F-R) proportional to F-R(-1.28). The difference in the slope is attributed to the fundamental difference between incoherent and coherent emission processes. In summary, these findings suggest a flare scenario in which bidirectional streams of electrons are accelerated during solar flares at heights of approximate to 10(4) km above the photosphere in rather compact regions (L less than or equal to 2000 km). The acceleration site is likely to be located near the top of flare loops (defined by HXR double footpoints) or in the cusp above, where electrons have also access to open field lines or larger arches. The observed bidirectionality of electron beams favors acceleration mechanisms with oppositely directed electric fields or stochastic acceleration in an X-type reconnection geometry. C1 ETH ZURICH,INST ASTRON,CH-8092 ZURICH,SWITZERLAND. NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. RP ASCHWANDEN, MJ (reprint author), UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742, USA. RI Dennis, Brian/C-9511-2012 NR 50 TC 98 Z9 103 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1995 VL 455 IS 1 BP 347 EP 365 DI 10.1086/176582 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TG830 UT WOS:A1995TG83000034 ER PT J AU HUBENY, I LITES, BW AF HUBENY, I LITES, BW TI PARTIAL REDISTRIBUTION IN MULTILEVEL ATOMS .1. METHOD AND APPLICATION TO THE SOLAR HYDROGEN LINE FORMATION SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATOMIC PROCESSES; LINE, FORMATION; RADIATIVE TRANSFER; SUN, CHROMOSPHERE ID RADIATIVE-TRANSFER; LYMAN-ALPHA; PROFILE COEFFICIENTS; CHROMOSPHERE; EMISSION; MODELS; DIAGNOSTICS; FORMULATION; COLLISIONS; ABSORPTION AB We present a robust method for solution of multilevel non-LTE line transfer problems including the effects of partial frequency redistribution (PRD). This method allows the self-consistent solution for redistribution of scattered line photons simultaneously in multiple transitions of a model atom, including the effects of resonant Raman scattering (''cross-redistribution'') among lines sharing common upper levels. The method is incorporated into the framework of the widely used non-LTE complete redistribution code MULTI. We have applied this method to the problem of transfer in hydrogen lines in a plane-parallel solar model atmosphere, including cross-redistribution between the H alpha and L beta, using general redistribution functions for the L alpha and L beta lines which are not restricted by the impact approximation. The convergence properties of this method are demonstrated to be comparable to that of the equivalent complete redistribution problem. In this solar model, PRD in the L alpha line produces the dominant influence on the level populations. It changes considerably the populations of the excited states of hydrogen, as well as the proton number density, in the middle and upper chromosphere, owing to modification of the L alpha wing radiation. The population of the hydrogen ground state undergoes only modest changes, however. The influence of cross-redistribution and PRD in L beta has a much smaller influence on the level populations but a considerable influence on the wing intensity of the L beta line. C1 NATL CTR ATMOSPHER RES, HIGH ALTITUDE OBSERV, BOULDER, CO 80307 USA. RP NASA, GODDARD SPACE FLIGHT CTR, UNIV SPACE RES ASSOC, CODE 681, GREENBELT, MD 20771 USA. NR 42 TC 26 Z9 26 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1995 VL 455 IS 1 BP 376 EP 388 DI 10.1086/176584 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TG830 UT WOS:A1995TG83000036 ER PT J AU JENNISKENS, P BLAKE, DF WILSON, MA POHORILLE, A AF JENNISKENS, P BLAKE, DF WILSON, MA POHORILLE, A TI HIGH-DENSITY AMORPHOUS ICE, THE FROST ON INTERSTELLAR GRAINS SO ASTROPHYSICAL JOURNAL LA English DT Article DE DUST, EXTINCTION; INFRARED, ISM, LINES AND BANDS; ISM, MOLECULES; LINE, PROFILES; METHODS, LABORATORY; MOLECULAR DATA ID OH STRETCHING REGION; PRESSURE-INDUCED AMORPHIZATION; INFRARED SPECTRAL PROPERTIES; SOLID WATER; ASTROPHYSICAL IMPLICATIONS; ABSORPTION FEATURES; MOLECULAR CLOUDS; LIQUID WATER; LIGHT-IONS; H2O ICE AB Most water ice in the universe is in a form which does not occur naturally on Earth and of which only minimal amounts have been made in the laboratory. We have encountered this ''high-density amorphous ice'' in electron diffraction experiments of low-temperature (T < 30 K) vapor-deposited water and have subsequently modeled its structure using molecular dynamics simulations. The characteristic feature of high-density amorphous ice is the presence of ''interstitiaI'' oxygen pair distances between 3 and 4 Angstrom. However, we find that the structure is best described as a collapsed lattice of the more familiar low-density amorphous form. These distortions are frozen in at temperatures below 38 K because, we propose, it requires the breaking of one hydrogen bond, on average, per molecule to relieve the strain and to restructure the lattice to that of low-density amorphous ice. Several features of astrophysical ice analogs studied in laboratory experiments are readily explained by the structural transition from high-density amorphous ice into low-density amorphous ice. Changes in the shape of the 3.07 mu m water band, trapping efficiency of CO, CO loss, changes in the CO band structure, and the recombination of radicals induced by low-temperature UV photolysis all covary with structural changes that occur in the ice during this amorphous to amorphous transition. While the 3.07 mu m ice band in various astronomical environments can be modeled with spectra of simple mixtures of amorphous and crystalline forms, the contribution of the high-density amorphous form nearly always dominates. RP JENNISKENS, P (reprint author), NASA,AMES RES CTR,PLANETARY BIOL BRANCH,DIV SPACE SCI,MAIL STOP 239-4,MOFFETT FIELD,CA 94035, USA. NR 87 TC 144 Z9 144 U1 2 U2 23 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1995 VL 455 IS 1 BP 389 EP 401 DI 10.1086/176585 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TG830 UT WOS:A1995TG83000037 ER PT J AU LEE, SJ OLINTO, AV SIGL, G AF LEE, SJ OLINTO, AV SIGL, G TI EXTRAGALACTIC MAGNETIC-FIELD AND THE HIGHEST ENERGY COSMIC-RAYS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC RAYS; GAMMA RAYS, THEORY; MAGNETIC FIELDS ID SPECTRUM AB The strength and spectrum of the extragalactic magnetic field (EGMF) are still unknown. Its measurement would help answer the question of whether galactic fields are purely a primordial relic or whether they were dynamically enhanced from a much smaller cosmological seed field. In this Letter, we show that the composition, spectrum, and directional distribution of extragalactic ultra-high-energy cosmic rays, with energies above similar or equal to 10(18) eV, can probe the large-scale component of the EGMF below the present observational upper limit of 10(-9) G. Cosmic-ray detectors under construction or currently in the proposal stage should be able to test the existence of the EGMFs on scales of a few to tens of megaparsecs and strengths in the range similar or equal to 10(-10) to 10(-9) G. C1 FERMILAB NATL ACCELERATOR LAB, NASA, FERMILAB ASTROPHYS CTR, BATAVIA, IL 60510 USA. RP UNIV CHICAGO, ENRICO FERMI INST, DEPT ASTRON & ASTROPHYS, CHICAGO, IL 60637 USA. NR 24 TC 37 Z9 37 U1 2 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1995 VL 455 IS 1 BP L21 EP L24 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TG831 UT WOS:A1995TG83100006 ER PT J AU MATHUR, S ELVIS, M SINGH, KP AF MATHUR, S ELVIS, M SINGH, KP TI STRONG X-RAY-ABSORPTION IN A BROAD ABSORPTION-LINE QUASAR - PHL-5200 SO ASTROPHYSICAL JOURNAL LA English DT Article DE QUASARS, ABSORPTION LINES; QUASARS, INDIVIDUAL (PHL 5200); X-RAYS, GALAXIES ID EMISSION; QSOS AB We present ASCA observations of the z = 1.98 prototype broad absorption line quasar (BALQSO): PHL 5200. The source was detected in both SIS and GIS. A power-law spectrum(alpha(E) = 0.6(-0.6)(+0.9)) with large intrinsic absorption (N-H = 1.3(-1.1)(+2.3) x 10(23) cm(-2)) best describes the spectrum. Excess column density over the local Galactic value is required at the 99% confidence level. This detection suggests that, although BALQSOs are X-ray-quiet, it is strong absorption in the BAL region that makes them appear faint to low-energy X-ray experiments. The required intrinsic absorbing column density is 2-3 orders of magnitude larger than earlier estimates of column densities in BALQSOs. This implies that the BAL systems are much more highly ionized than was previously thought. C1 NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. RP MATHUR, S (reprint author), HARVARD SMITHSONIAN CTR ASTROPHYS,60 GARDEN ST,CAMBRIDGE,MA 02138, USA. NR 30 TC 50 Z9 50 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1995 VL 455 IS 1 BP L9 EP L12 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TG831 UT WOS:A1995TG83100003 ER PT J AU SZKODY, P SILBER, A HOARD, DW FIERCE, E SINGH, KP BARRETT, P SCHLEGEL, E PIIROLA, V AF SZKODY, P SILBER, A HOARD, DW FIERCE, E SINGH, KP BARRETT, P SCHLEGEL, E PIIROLA, V TI IDENTIFICATION OF THE SOFT-X-RAY SOURCE WGA J1802.1+1804 WITH A NEW MAGNETIC CATACLYSMIC VARIABLE SO ASTROPHYSICAL JOURNAL LA English DT Article DE BINARIES, SPECTROSCOPIC; NOVAE, CATACLYSMIC VARIABLES; STARS, INDIVIDUAL (WGA J1802.1+1804); X-RAYS, STARS ID LONG-PERIOD AM AB We have discovered a bright (V similar to 14.5) cataclysmic variable during observations of the soft X-ray sources in the list of Singh et al. The optical source, which is coincident with the X-ray position of WGA J1802.1+1804, shows all the characteristics of a magnetic AM Herculis-type system: circular polarization, He II strength greater than H beta, multiple line components, and a consistent photometric, polarimetric, spectroscopic, and X-ray period of 113 minutes. The X-ray spectrum shows a dominant soft blackbody (kT = 20-45 eV) and a weaker bremsstrahlung component (kT > 1 keV), while the circular polarization is relatively low (4% in the red). C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. TUORLA OBSERV,SF-21500 PUKKIO,FINLAND. RP SZKODY, P (reprint author), UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195, USA. NR 15 TC 13 Z9 13 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1995 VL 455 IS 1 BP L43 EP & PN 2 PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TG831 UT WOS:A1995TG83100011 ER PT J AU Baloga, S Spudis, PD Guest, JE AF Baloga, S Spudis, PD Guest, JE TI The dynamics of rapidly emplaced terrestrial lava flows and implications for planetary volcanism SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ERUPTIONS; MARS AB The Kaupulehu 1800-1801 lava flow of Hualalai volcano and the 1823 Keaiwa flow from the Great Crack of the Kilauea southwest rift zone had certain unusual and possibly unique properties for terrestrial basaltic lava flows. Both flows apparently had very low viscosities, high effusion rates, and uncommonly rapid rates of advance. Ultramafic xenolith nodules in the 1801 flow form stacks of cobbles with lava rinds of only millimeter thicknesses. The velocity of the lava stream in the 1801 flow was extremely high, at least 10 m s(-1) (more than 40 km h(-1)). Observations and geological evidence suggest similarly high velocities for the 1823 flow. The unusual eruption conditions that produced these lava flows suggest a floodlike mode of emplacement unlike that of most other present-day flows. Although considerable effort has gone into understanding the viscous fluid dynamics and thermal processes that often occur in basaltic flows, the unusual conditions prevalent for the Kaupulehu and Keaiwa flows necessitate different modeling considerations. We propose an elementary flood model for this type of lava emplacement and show that it produces consistent agreement with the overall dimensions of the flow, channel sizes, and other supporting field evidence. The reconstructed dynamics of these rapidly emplaced terrestrial lava flows provide significant insights about the nature of these eruptions and their analogs in planetary volcanism. C1 UNIV LONDON OBSERV, LONDON NW7 4SD, ENGLAND. LUNAR & PLANETARY INST, HOUSTON, TX 77058 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RP PROXEMY RES INC, 20528 FARCROFT LANE, LAYTONSVILLE, MD 20882 USA. NR 33 TC 42 Z9 42 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1995 VL 100 IS B12 BP 24509 EP 24519 DI 10.1029/95JB02844 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TK614 UT WOS:A1995TK61400030 ER PT J AU KIM, JT WANG, H TSAI, CC BAHNS, JT STWALLEY, WC JONG, G LYYRA, AM AF KIM, JT WANG, H TSAI, CC BAHNS, JT STWALLEY, WC JONG, G LYYRA, AM TI OBSERVATION OF THE 4-(3)SIGMA(+)(G), 3-(3)PI(G), 2-(3)DELTA(G), AND B-(3)PI(U), STATES OF K-39(2) BY PERTURBATION FACILITATED OPTICAL-OPTICAL DOUBLE-RESONANCE SPECTROSCOPY (VOL 102, PG 6646, 1995) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Correction, Addition C1 UNIV CONNECTICUT,INST MAT SCI,STORRS,CT 06269. CALTECH,JET PROP LAB,PASADENA,CA 91109. TEMPLE UNIV,DEPT PHYS,PHILADELPHIA,PA 19122. RP KIM, JT (reprint author), UNIV CONNECTICUT,DEPT PHYS,STORRS,CT 06269, USA. NR 1 TC 12 Z9 13 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 8 PY 1995 VL 103 IS 22 BP 9891 EP 9891 DI 10.1063/1.469902 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TH657 UT WOS:A1995TH65700049 ER PT J AU BROCK, CA HAMILL, P WILSON, JC JONSSON, HH CHAN, KR AF BROCK, CA HAMILL, P WILSON, JC JONSSON, HH CHAN, KR TI PARTICLE FORMATION IN THE UPPER TROPICAL TROPOSPHERE - A SOURCE OF NUCLEI FOR THE STRATOSPHERIC AEROSOL SO SCIENCE LA English DT Article ID ANTARCTIC OZONE EXPERIMENT; CONDENSATION NUCLEI; DEHYDRATION; NUCLEATION; CHEMISTRY; LAYER AB Atmospheric measurements and numerical calculations described here indicate that binary homogeneous nucleation of H2SO4-H2O particles occurs in the upper tropical troposphere. Particle concentrations decrease with increasing altitude above the tropical tropopause as a result of coagulation during the upward air transport produced by stratospheric circulations. During the extended periods of time that volcanic eruptions do not strongly influence stratospheric particle number concentrations, particles formed in the upper tropical troposphere provide nuclei upon which oxidized sulfur gases condense in the stratosphere. This particle source, coupled with aerosol microphysical properties and atmospheric transport, governs the number concentration of particles in the lower tropical and mid-latitude stratosphere. C1 SAN JOSE STATE UNIV,DEPT PHYS,SAN JOSE,CA 95192. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP BROCK, CA (reprint author), UNIV DENVER,DEPT ENGN,DENVER,CO 80208, USA. RI Brock, Charles/G-3406-2011 OI Brock, Charles/0000-0002-4033-4668 NR 55 TC 136 Z9 136 U1 0 U2 13 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 8 PY 1995 VL 270 IS 5242 BP 1650 EP 1653 DI 10.1126/science.270.5242.1650 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TJ293 UT WOS:A1995TJ29300044 ER PT J AU KEMP, P AF KEMP, P TI CIRCUIT EXPANDS 8-PIN 68HC11 PORT TO 64 PINS SO EDN LA English DT Note RP KEMP, P (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAHNERS-DENVER PUBLISHING CO PI HIGHLANDS RANCH PA 8773 S RIDGELINE BLVD, HIGHLANDS RANCH, CO 80126-2329 SN 0012-7515 J9 EDN JI EDN PD DEC 7 PY 1995 VL 40 IS 25 BP 124 EP & PG 0 WC Engineering, Electrical & Electronic SC Engineering GA TJ245 UT WOS:A1995TJ24500028 ER PT J AU HILL, DJT RASOUL, FA FORSYTHE, JS ODONNELL, JH POMERY, PJ GEORGE, GA YOUNG, PR CONNELL, JW AF HILL, DJT RASOUL, FA FORSYTHE, JS ODONNELL, JH POMERY, PJ GEORGE, GA YOUNG, PR CONNELL, JW TI EFFECT OF SIMULATED LOW-EARTH-ORBIT RADIATION ON POLYIMIDES (UV DEGRADATION STUDY) SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article ID PHOTODEGRADATION; RESONANCE; MECHANISM AB UV degradation of polyimide films in air and vacuum were studied using UV-visible, ESR, FTIR, and XPS spectroscopies. The UV-visible spectra of polyimide films showed a blue shift in the absorption compared to Kapton. This behavior was attributed to the presence of bulky groups and kinks along the polymer chains which disrupt the formation of a charge-transfer complex. The UV-visible spectra showed also that UV irradiation of polyimides result extensively in surface degradation, leaving the bulk of the polymer intact. ESR spectra of polyimides irradiated in vacuum revealed the formation of stable carbon-centered radicals which give a singlet ESR spectrum, while polyimides irradiated in air produced an asymmetric signal shifted to a lower magnetic field, with a higher g value and line width. This signal was attributed to oxygen-centered radicals of peroxy and/or alkoxy type. The rate of radical formation in air was twofold higher than for vacuum irradiation and reached a plateau after a short time. This suggests a continuous depletion of radicals on the surface via an ablative degradation process. FTIR, XPS, and weight loss studies supported this postulate. An XPS study of the surface indicated a substantial increase in the surface oxidation after irradiation in air. The sharp increase in the C-O binding energy peak relative to the C-C peak was believed to be associated with an aromatic ring-opening reaction. (C) 1995 John Wiley & Sons, Inc. C1 NASA,LANGLEY RES CTR,POLMER MAT BRANCH,HAMPTON,VA 23665. RP HILL, DJT (reprint author), UNIV QUEENSLAND,POLYMER MAT & RADIAT GRP,ST LUCIA,QLD 4072,AUSTRALIA. OI Forsythe, John/0000-0003-2849-229X NR 23 TC 26 Z9 28 U1 2 U2 8 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD DEC 5 PY 1995 VL 58 IS 10 BP 1847 EP 1856 DI 10.1002/app.1995.070581023 PG 10 WC Polymer Science SC Polymer Science GA TE638 UT WOS:A1995TE63800023 ER PT J AU RASOUL, FA HILL, DJT FORSYTHE, JS ODONNELL, JH GEORGE, GA POMERY, PJ YOUNG, PR CONNELL, JW AF RASOUL, FA HILL, DJT FORSYTHE, JS ODONNELL, JH GEORGE, GA POMERY, PJ YOUNG, PR CONNELL, JW TI SURFACE-PROPERTIES OF FLUORINATED POLYIMIDES EXPOSED TO VUV AND ATOMIC OXYGEN SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article AB The effect of atomic oxygen flux and VUV radiation alone and in combination on the surface of fluorinated polyimide films was studied using XPS spectroscopy. Exposure of fluorinated polyimides to VUV radiation alone caused no observable damage to the polymer surface, while an atomic oxygen flux resulted in substantial oxidation of the surface. On the other hand, exposure to VUV radiation and atomic oxygen in combination caused extensive oxidation of the polymer surface after only 2 min of exposure. The amount of oxidized carbon on the polymer surface indicated that there is aromatic ring-opening oxidation. The changes in the O1s/C1s, N1s/C1s, and F1s/C1s ratios suggested that an ablative degradation process is highly favorable. A synergistic effect of VUV radiation in the presence of atomic oxygen is clearly evidenced from the XPS study. The atomic oxygen could be considered as the main factor in the degradation process of fluorinated polyimide films exposed to a low earth orbit environment. (C) 1995 John Wiley & Sons, Inc. C1 UNIV QUEENSLAND,POLYMER MAT & RADIAT GRP,ST LUCIA,QLD 4072,AUSTRALIA. NASA,LANGLEY RES CTR,POLYMER MAT BRANCH,HAMPTON,VA 23665. OI Forsythe, John/0000-0003-2849-229X NR 14 TC 27 Z9 30 U1 0 U2 7 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD DEC 5 PY 1995 VL 58 IS 10 BP 1857 EP 1864 DI 10.1002/app.1995.070581024 PG 8 WC Polymer Science SC Polymer Science GA TE638 UT WOS:A1995TE63800024 ER PT J AU JAUNCEY, DL TINGAY, SJ PRESTON, RA REYNOLDS, JE LOVELL, JEJ MCCULLOCH, PM TZIOUMIS, AK COSTA, ME MURPHY, DW MEIER, DL JONES, DL AMY, SW BIGGS, JD BLAIR, DG CLAY, RW EDWARDS, PG ELLINGSEN, SP FERRIS, RH GOUGH, RG HARBISON, P JONES, PA KING, EA KEMBALL, AJ MIGENES, V NICOLSON, GD SINCLAIR, MW VANOMMEN, T WARK, RM WHITE, GL AF JAUNCEY, DL TINGAY, SJ PRESTON, RA REYNOLDS, JE LOVELL, JEJ MCCULLOCH, PM TZIOUMIS, AK COSTA, ME MURPHY, DW MEIER, DL JONES, DL AMY, SW BIGGS, JD BLAIR, DG CLAY, RW EDWARDS, PG ELLINGSEN, SP FERRIS, RH GOUGH, RG HARBISON, P JONES, PA KING, EA KEMBALL, AJ MIGENES, V NICOLSON, GD SINCLAIR, MW VANOMMEN, T WARK, RM WHITE, GL TI SUBPARSEC-SCALE STRUCTURE AND EVOLUTION OF CENTAURUS-A (NGC5128) SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article; Proceedings Paper CT Colloquium on Quasars and Active Galactic Nuclei - High Resolution Radio Imaging CY MAR 24-25, 1995 CL NATL ACD SCI, BECKMAN CTR, IRVINE, CA HO NATL ACD SCI, BECKMAN CTR ID NGC-5128; NUCLEUS; SYSTEM; JET AB We present a series of 8.4-GHz very-long-baseline radio interferometry images of the nucleus of Centaurus A (NGC5128) made with a Southern Hemisphere array, representing a 3.3-year monitoring effort. The nuclear radio jet is approximate to 50 milliarcseconds in extent, or at the 3.5-megaparsec distance of NGC5128, approximate to 1 parsec in length. Subluminal motion is seen and structural changes are observed on time scales shorter than 4 months. High-resolution observations at 4.8 and 8.4 GHz made in November 1992 reveal a complex morphology and allow us to unambiguously identify the self-absorbed core located at the southwestern end of the jet. C1 MT STROMLO & SIDING SPRING OBSERV,CANBERRA,ACT 2611,AUSTRALIA. CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV TASMANIA,HOBART,TAS 7001,AUSTRALIA. UNIV WESTERN AUSTRALIA,NEDLANDS,WA 6009,AUSTRALIA. UNIV SYDNEY,SYDNEY,NSW 2006,AUSTRALIA. CURTIN UNIV TECHNOL,PERTH,WA 6001,AUSTRALIA. UNIV ADELAIDE,ADELAIDE,SA 5001,AUSTRALIA. BRITISH AEROSP PLC,CANBERRA,ACT 2601,AUSTRALIA. UNIV WESTERN SYDNEY NEPEAN,KINGSWOOD,NSW 2747,AUSTRALIA. HARTEBEESTHOEK RADIO ASTRON OBSERV,KRUGERSDORP 1740,SOUTH AFRICA. RP JAUNCEY, DL (reprint author), AUSTRALIA TELESCOPE NATL FACIL,EPPING,NSW 2121,AUSTRALIA. RI Tingay, Steven/B-5271-2013; van Ommen, Tas/B-5020-2012; King, Edward/A-1473-2012; Ellingsen, Simon/J-7754-2014; Migenes, Victor/F-3157-2015 OI van Ommen, Tas/0000-0002-2463-1718; King, Edward/0000-0002-6898-2130; Ellingsen, Simon/0000-0002-1363-5457; Migenes, Victor/0000-0002-7990-2191 NR 20 TC 5 Z9 5 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 5 PY 1995 VL 92 IS 25 BP 11368 EP 11370 DI 10.1073/pnas.92.25.11368 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TJ222 UT WOS:A1995TJ22200010 PM 11607599 ER PT J AU ZYPMAN, F FERRANTE, J AF ZYPMAN, F FERRANTE, J TI TIGHT-BINDING SURFACE CORRECTION TO THE EMBEDDED-ATOM METHOD EMBEDDING FUNCTION SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID 4D TRANSITION-METALS; FCC METALS; ENERGIES; HYDROGEN; ALLOYS; MODEL; NI; CU AB The embedded-atom method (EAM) has been highly successful in predicting many properties of fee metals. However, it is known to underestimate surface energies by as much as 40 to 50%. This suggests that it would be interesting to explore the possibility of obtaining a surface correction to the embedding energy. In this paper, the functional form for a surface embedding function, F-surface, for the embedded-atom method (EAM) is proposed. The existence of a different F for surface atoms than for bulk atoms stems from the fact that the presence of a surface modifies the energy band structure of the solid. In order to study this change, we used the tight-binding method, that provides the ingredients needed to obtain an explicit expression for the relevant quantities. By comparing the energies of the EAM and tight binding for a surface-terminated bulk, we obtain a correction to the EAM embedding function and the EAM energy for the system. In order to quantify our result we apply it to the lower-index surface planes of Ag and Pd by adjusting our tight-binding parameters with known, available first-principles results for the (111) plane. We then predict the surface energies for the (100) and (110) planes with our method and show an improvement over using the bulk embedding function as compared with first-principles values. C1 UNIV REPUBLICA TRISTAN NARVAJA,FAC CIENCIAS,INST FIS,MONTEVIDEO 11200,URUGUAY. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP ZYPMAN, F (reprint author), UNIV PUERTO RICO,DEPT PHYS,HUMACAO,PR 00791, USA. NR 17 TC 2 Z9 2 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD DEC 4 PY 1995 VL 7 IS 49 BP 9433 EP 9438 DI 10.1088/0953-8984/7/49/008 PG 6 WC Physics, Condensed Matter SC Physics GA TJ569 UT WOS:A1995TJ56900008 ER PT J AU Bailey, DH AF Bailey, DH TI A Fortran 90-based multiprecision system SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Article DE languages; performance; arithmetic; Fortran 90; multiprecision AB A new version of a Fortran multiprecision computation system, based on the Fortran 90 language, is described. With this new approach, a translator program is not required-translation of Fortran code for multiprecision is accomplished by merely utilizing advanced features of Fortran 90, such as derived data types and operator extensions. This approach results in more-reliable translation and permits programmers of multiprecision applications to utilize the full power of Fortran 90. Three multiprecision data types are supported in this system: multiprecision integer, real, and complex. All the usual Fortran conventions for mixed-mode operations are supported, and many of the Fortran intrinsics, such as SIN, EXP, and MOD, are supported with multiprecision arguments. An interesting application of this software, wherein new number-theoretic identities have been discovered by means of multiprecision computations, is included also. RP Bailey, DH (reprint author), NASA,AMES RES CTR,NAS SCI COMPUTAT BRANCH,MAIL STOP T27A-1,MOFFETT FIELD,CA 94035, USA. NR 7 TC 117 Z9 120 U1 0 U2 2 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0098-3500 J9 ACM T MATH SOFTWARE JI ACM Trans. Math. Softw. PD DEC PY 1995 VL 21 IS 4 BP 379 EP 387 DI 10.1145/212066.212075 PG 9 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA TL693 UT WOS:A1995TL69300003 ER PT J AU Chen, CT Marder, SR AF Chen, CT Marder, SR TI Synthesis and linear optical spectroscopy of thioflavylium near-infrared absorbing dyes SO ADVANCED MATERIALS LA English DT Article ID SUSCEPTIBILITIES; THIOPHENES AB Communication: Near-infrared adsorbing dyes have potential applications in optical recording and printing technology which employs inexpensive semiconductor lasers that emit light around 800 nm. A convenient and high yield synthesis of thioflavylium chromophores is presented, materials which are found to act as a powerful acceptor for creating such near-IR absorbing dyes. C1 CALTECH,BECKMAN INST,MOLEC MAT RESOURCE CTR,PASADENA,CA 91125. CALTECH,JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109. RI Chen, Chin-Ti/E-5341-2015 NR 25 TC 19 Z9 19 U1 0 U2 3 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD DEC PY 1995 VL 7 IS 12 BP 1030 EP & DI 10.1002/adma.19950071214 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA TL756 UT WOS:A1995TL75600013 ER PT J AU JONES, LE CARDEN, HD AF JONES, LE CARDEN, HD TI COMPOSITE AIRCRAFT CRASH TESTING SO AEROSPACE ENGINEERING LA English DT Article RP JONES, LE (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC AUTOMOTIVE ENG INC PI WARRENDALE PA 400 COMMONWEALTH DRIVE, WARRENDALE, PA 15096 SN 0736-2536 J9 AEROSPACE ENG JI Aerosp. Eng. PD DEC PY 1995 VL 15 IS 12 BP 15 EP 19 PG 5 WC Engineering, Aerospace SC Engineering GA TK278 UT WOS:A1995TK27800012 ER PT J AU LYLE, KH SILCOX, RJ AF LYLE, KH SILCOX, RJ TI ACTIVE TRIM PANELS FOR AIRCRAFT INTERIOR NOISE-REDUCTION SO AEROSPACE ENGINEERING LA English DT Article C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP LYLE, KH (reprint author), USA,RES LAB,VEHICLE STRUCT DIRECTORATE,WASHINGTON,DC 20310, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SOC AUTOMOTIVE ENG INC PI WARRENDALE PA 400 COMMONWEALTH DRIVE, WARRENDALE, PA 15096 SN 0736-2536 J9 AEROSPACE ENG JI Aerosp. Eng. PD DEC PY 1995 VL 15 IS 12 BP 21 EP 25 PG 5 WC Engineering, Aerospace SC Engineering GA TK278 UT WOS:A1995TK27800013 ER PT J AU HAYDER, ME TURKEL, E AF HAYDER, ME TURKEL, E TI NONREFLECTING BOUNDARY-CONDITIONS FOR JET FLOW COMPUTATIONS SO AIAA JOURNAL LA English DT Article ID WAVES AB In this study, we examine the effect of boundary conditions, both inflow and outflow, on the predicted flow fluctuations in a supersonic Set entering into a subsonic outer flow. Various boundary conditions are used to compute the flowfield of a laminar axisymmetric jet excited at the inflow by a disturbance given by the corresponding eigenfunction of the linearized stability equations. Our goal is to determine the suitability of these conditions for computations of time-dependent flows. We solve the full time-dependent Navier-Stokes equations by a high-order numerical scheme. For very small excitations, the computed growth of the modes closely corresponds to that predicted by the linear theory. We then vary the excitation level and examine the effect of the boundary conditions in the nonlinear flow regime. RP HAYDER, ME (reprint author), NASA,LEWIS RES CTR,INST COMPUTAT MECH PROPULS,CLEVELAND,OH 44135, USA. RI Turkel, Eli/F-6297-2011 OI Turkel, Eli/0000-0003-4273-0303 NR 24 TC 23 Z9 23 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1995 VL 33 IS 12 BP 2264 EP 2270 DI 10.2514/3.12978 PG 7 WC Engineering, Aerospace SC Engineering GA TJ059 UT WOS:A1995TJ05900004 ER PT J AU COON, MD TOBAK, M AF COON, MD TOBAK, M TI EXPERIMENTAL-STUDY OF SADDLE-POINT OF ATTACHMENT IN LAMINAR JUNCTURE FLOW SO AIAA JOURNAL LA English DT Article ID HORSESHOE VORTEX; TURBULENT JUNCTION AB An experimental study of laminar horseshoe vortex flows upstream of a cylinder/flat plate juncture has been conducted to verify the existence of saddle-point-of-attachment topologies, In the classical depiction of this flowfield, a saddle point of separation exists on the flat plate upstream of the cylinder, and the boundary layer separates from the surface, Recent computations have indicated that the topology may actually involve a saddle point of attachment on the surface and additional singular points in the how, Laser light sheet flow visualizations have been performed on the symmetry plane and crossflow planes to identify the saddle-point-of-attachment flowfields. The visualizations reveal that saddle-point-of-attachment topologies occur over a range of Reynolds number in both single and multiple vortex regimes, An analysis of the flow topologies is presented that describes the existence and evolution of the singular points in the flowfield. RP COON, MD (reprint author), NASA,AMES RES CTR,MS 260-1,MOFFETT FIELD,CA 94035, USA. NR 27 TC 9 Z9 10 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1995 VL 33 IS 12 BP 2288 EP 2292 DI 10.2514/3.12981 PG 5 WC Engineering, Aerospace SC Engineering GA TJ059 UT WOS:A1995TJ05900007 ER PT J AU ROBINSON, DF HARRIS, JE HASSAN, HA AF ROBINSON, DF HARRIS, JE HASSAN, HA TI UNIFIED TURBULENCE CLOSURE-MODEL FOR AXISYMMETRICAL AND PLANAR FREE SHEAR FLOWS SO AIAA JOURNAL LA English DT Article ID RADIAL JETS AB A new two-equation turbulence model based on the exact turbulent kinetic energy and the variance of vorticity or enstrophy equations is developed and used to calculate planar and axisymmetric free shear flows. It is shown that one set of model constants reproduces available growth rates and similarity profiles of velocity and shear stress. In general, agreement is well within the scatter of experimental data. C1 NASA,LANGLEY RES CTR,FLOW MODELING & CONTROL BRANCH,HAMPTON,VA 23681. RP ROBINSON, DF (reprint author), N CAROLINA STATE UNIV,RALEIGH,NC 27695, USA. NR 25 TC 12 Z9 13 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1995 VL 33 IS 12 BP 2325 EP 2331 DI 10.2514/3.12987 PG 7 WC Engineering, Aerospace SC Engineering GA TJ059 UT WOS:A1995TJ05900013 ER PT J AU JAUNKY, N KNIGHT, NF AF JAUNKY, N KNIGHT, NF TI BUCKLING ANALYSIS OF GENERAL TRIANGULAR ANISOTROPIC PLATES USING POLYNOMIALS SO AIAA JOURNAL LA English DT Article ID FLEXURAL VIBRATION AB The problem of buckling of general triangular anisotropic plates with different boundary conditions subjected to combined in-plane loads is considered. Solutions for plate buckling are obtained by using a Rayleigh-Ritz method combined with a variational formulation. The Ritz functions consist of polynomials that include circulation functions that are used to impose various boundary conditions. Both classical laminated-plate theory and first-order shear-deformation theory are used. Numerical buckling results obtained for isotropic and anisotropic triangular plates are compared with results from existing series solutions. C1 NASA,LANGLEY RES CTR,STRUCT MECH BRANCH,HAMPTON,VA 23681. RP JAUNKY, N (reprint author), OLD DOMINION UNIV,DEPT AEROSP ENGN,NORFOLK,VA 23529, USA. NR 19 TC 8 Z9 11 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1995 VL 33 IS 12 BP 2414 EP 2417 DI 10.2514/3.13000 PG 4 WC Engineering, Aerospace SC Engineering GA TJ059 UT WOS:A1995TJ05900026 ER PT J AU HUANG, PG AF HUANG, PG TI COMMENT ON APPLICATION OF WALL FUNCTIONS TO GENERALIZED NONORTHOGONAL CURVILINEAR COORDINATE SYSTEMS SO AIAA JOURNAL LA English DT Letter RP HUANG, PG (reprint author), NASA,AMES RES CTR,MCAT INST,MS 229-1,MOFFETT FIELD,CA 94035, USA. NR 2 TC 1 Z9 4 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1995 VL 33 IS 12 BP 2445 EP 2446 DI 10.2514/3.13013 PG 2 WC Engineering, Aerospace SC Engineering GA TJ059 UT WOS:A1995TJ05900039 ER PT J AU POMRANING, GC GANAPOL, BD AF POMRANING, GC GANAPOL, BD TI ASYMPTOTICALLY CONSISTENT REFLECTION BOUNDARY-CONDITIONS FOR DIFFUSION-THEORY SO ANNALS OF NUCLEAR ENERGY LA English DT Article ID TRANSPORT PROBLEMS; EQUATION AB It is well known that the classic diffusion equation is an asymptotic limit of the one-speed linear transport equation. In this paper, we carry out the analysis required to obtain an asymptotically consistent boundary condition for this diffusion equation in the case of partial surface reflection. The specification of this boundary condition requires the transport theory solution to a purely scattering halfspace problem. A variational treatment is used to obtain explicit results for this halfspace problem in the general case. In the special case of purely diffuse reflection, simple considerations give exact halfspace results, and a more involved exact halfspace analysis is presented in the case of specular reflection. These exact results are used to assess the accuracy of the variational treatment. C1 NASA,AMES RES CTR,ECOSYST SCI & TECHNOL BRANCH,MOFFETT FIELD,CA 94035. UNIV ARIZONA,DEPT NUCL & ENERGY ENGN,TUCSON,AZ 85721. RP POMRANING, GC (reprint author), UNIV CALIF LOS ANGELES,SCH ENGN & APPL SCI,LOS ANGELES,CA 90024, USA. NR 24 TC 8 Z9 8 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD DEC PY 1995 VL 22 IS 12 BP 787 EP 817 DI 10.1016/0306-4549(94)00097-X PG 31 WC Nuclear Science & Technology SC Nuclear Science & Technology GA RR586 UT WOS:A1995RR58600004 ER PT J AU TORR, MR TORR, DG AF TORR, MR TORR, DG TI COMPACT IMAGING SPECTROGRAPH FOR BROAD-BAND SPECTRAL SIMULTANEITY SO APPLIED OPTICS LA English DT Article ID ATLAS-1 AB We report on the design of a small spectrograph that is capable of imaging several thousand angstroms simultaneously at a moderate spectral resolution. The prototype instrument included a number of developmental items that were used to assess their utility in this and other applications. Some we would recommend using again, some we would not. In the configuration that was built and tested, the instantaneous wavelength range was chosen to be 3700-11,700 Angstrom. However, the wavelength range could be selected for a lower wavelength, as low as similar to 1200 Angstrom. The spectral imaging was achieved with an intensified-CCD focal-plane detector. The broad wavelength coverage was achieved with a matrix of four diffraction gratings and a custom-designed photocathode system. The photocathode was specially built to provide a response over the chosen broad wavelength range by use of a single image intensifier. The theoretical spectral resolution of the instrument varied from 12 to 20 Angstrom depending on wavelength segment. A higher spectral resolution can be selected at the expense of total wavelength coverage. The optical system was designed to be moderately fast (f/6) when considered at the level of each of the four optical subchannels and suitable for use on relatively weak airglow signals. The instrument was designed to be readily portable, weighing 15 kg, with an envelope of 37 cm x 37 cm x 48 cm. The advantages and weaknesses of such an instrument are discussed, and improvements are suggested for specific applications. This study represents a stepping stone in the evolution of electronic spectrographs and leads to later designs that are currently being evaluated. C1 UNIV ALABAMA,OPT AERON LAB,HUNTSVILLE,AL 35899. RP TORR, MR (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,PAYLOAD PROJECTS OFF,HUNTSVILLE,AL 35812, USA. NR 17 TC 6 Z9 7 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 1 PY 1995 VL 34 IS 34 BP 7888 EP 7898 PG 11 WC Optics SC Optics GA TH295 UT WOS:A1995TH29500013 PM 21068883 ER PT J AU Guirado, JC Marcaide, JM Alberdi, A Elosegui, P Ratner, MI Shapiro, II Kilger, R Mantovani, F Venturi, T Rius, A Ros, E Trigilio, C Whitney, AR AF Guirado, JC Marcaide, JM Alberdi, A Elosegui, P Ratner, MI Shapiro, II Kilger, R Mantovani, F Venturi, T Rius, A Ros, E Trigilio, C Whitney, AR TI Proper motion of components in 4C 39.25 SO ASTRONOMICAL JOURNAL LA English DT Article ID COMPACT RADIO-SOURCES; VLBI OBSERVATIONS; INTERFEROMETRY; 4C-39.25; GEODESY; 4C39.25; SYSTEM AB From a series of simultaneous 8.4 and 2.3 GHz VLBI observations of the quasar 4C 39.25 phase referenced to the radio source 0920 + 390, carried out in 1990-1992, we have measured the proper motion of component b in 4C 39.25: mu(alpha) = 90 +/- 43 mu as/yr, mu(delta) = 7 +/- 68 mu as/yr, where the quoted uncertainties account for the contribution of the statistical standard deviation and the errors assumed for the parameters related to the geometry of the interferometric array, the atmosphere, and the source structure. This proper motion is consistent with earlier interpretations of VLBI hybrid mapping results, which showed an internal motion of this component with respect to other structural components, Our differential astrometry analyses show component b to be the one in motion, Our results thus further constrain models of this quasar. (C) 1995 American Astronomical Society. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV VALENCIA,DEPT ASTRON,E-46100 BURJASSOT,SPAIN. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. INTA,ASTRON ESPACIAL & FIS FUNDAMENTAL LAB,E-28080 MADRID,SPAIN. SATELLITENBEOBACHTUNGSSTN WETTZELL,D-93444 KOETZTING,GERMANY. CNR,IST RADIOASTRON,I-40129 BOLOGNA,ITALY. CSIC,CTR ESTUDIOS AVANZADOS,E-17300 BARCELONA,SPAIN. CNR,IST RADIOASTRON,I-96017 NOTO,ITALY. NEROC,HAYSTACK OBSERV,WESTFORD,MA 01886. RP Guirado, JC (reprint author), CSIC,INST ASTROFIS ANDALUCIA,E-18080 GRANADA,SPAIN. RI Antonio, Rius/A-4873-2012; OI Antonio, Rius/0000-0002-5947-2649; Venturi, Tiziana/0000-0002-8476-6307 NR 44 TC 27 Z9 28 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 1995 VL 110 IS 6 BP 2586 EP 2596 DI 10.1086/117715 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TL326 UT WOS:A1995TL32600007 ER PT J AU Hickman, MA Sloan, GC Canterna, R AF Hickman, MA Sloan, GC Canterna, R TI An infrared color-magnitude relationship SO ASTRONOMICAL JOURNAL LA English DT Article ID MAGELLANIC CLOUDS; NEARBY GALAXIES; MIRA VARIABLES; LUMINOUS STARS; SUPER-GIANTS; PERIOD; SUPERGIANTS; SHELLS; DUST AB We have investigated a sample of dusty supergiants and Mira variables and have found a roughly linear relationship between the absolute magnitude at 12 mu m and the [12]-[25] color. Both samples follow the same infrared color-magnitude relationship, which may serve as a distance indicator and a means of better understanding the mass-loss and dust-formation mechanisms of evolved stars. (C) 1995 American Astronomical Society. C1 UNIV WYOMING,DEPT PHYS & ASTRON,LARAMIE,WY 82071. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 23 TC 11 Z9 11 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 1995 VL 110 IS 6 BP 2910 EP 2913 DI 10.1086/117738 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TL326 UT WOS:A1995TL32600030 ER PT J AU VanBuren, D NoriegaCrespo, A Dgani, R AF VanBuren, D NoriegaCrespo, A Dgani, R TI An IRAS/ISSA survey of bow shocks around runaway stars SO ASTRONOMICAL JOURNAL LA English DT Article ID H-II REGIONS; NEBULA AB We searched the IRAS data for bow shock-like objects like those known around zeta Oph and alpha Cam near the positions of 188 runaway stars. Based primarily on the presence and morphology of excess 60 mu m emission we identify 58 candidate bow shocks, for which we determine photometric and morphological parameters. Previously only a dozen of so were known. Well-resolved structures are present around 25 stars. A comparison of the distribution of symmetry axes of the infrared nebulae with the proper motions of the stars indicate the two directions are very significantly aligned. The observed alignment strongly suggests that the structures we see arise from the interaction of stellar winds with the interstellar medium, justifying the identification of these far-infrared objects as stellar wind bow shocks. (C) 1995 American Astronomical Society. C1 JET PROPULS LAB,PASADENA,CA 91125. RP VanBuren, D (reprint author), CALTECH,CTR INFRARED PROC & ANAL,PASADENA,CA 91125, USA. NR 16 TC 70 Z9 70 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 1995 VL 110 IS 6 BP 2914 EP 2925 DI 10.1086/117739 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TL326 UT WOS:A1995TL32600031 ER PT J AU LESTRADE, JF JONES, DL PRESTON, RA PHILLIPS, RB TITUS, MA KOVALEVSKY, J LINDEGREN, L HERING, R FROESCHLE, M FALIN, JL MIGNARD, F JACOBS, CS SOVERS, OJ EUBANKS, M GABUZDA, D AF LESTRADE, JF JONES, DL PRESTON, RA PHILLIPS, RB TITUS, MA KOVALEVSKY, J LINDEGREN, L HERING, R FROESCHLE, M FALIN, JL MIGNARD, F JACOBS, CS SOVERS, OJ EUBANKS, M GABUZDA, D TI PRELIMINARY LINK OF THE HIPPARCOS AND VLBI REFERENCE FRAMES SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ASTROMETRY; REFERENCE SYSTEMS; TECHNIQUES, INTERFEROMETRIC ID OPTICAL POSITIONS; RADIO STARS; CATALOG AB We present a comparison of VLBI and Hipparcos astrometric parameters of several optically bright radio-emitting stars. The systematic discrepancies found in these preliminary data can be removed by performing a single global rotation between the extragalactic and Hipparcos reference frames. Two estimates of this rotation and its time derivative have been made by using seven and six link stars from the two Hipparcos reduction consortia FAST and NDAC, respectively. The three angles and annual rates of rotation between the two frames are determined at better than the milli-arcsec level. The angles of rotation found are relative to a VLBI extragalactic reference frame that is defined by the IERS VLBI coordinates of the extragalactic reference sources used for the differential VLBI measurement of the link stars. The post-fit residuals of the star coordinates and proper motion components after the adjustment of the global rotation indicate that the consistency between the Hipparcos and VLBI astrometric techniques is at the milli-arcsec level. This is the first cross-check between these two astrometric techniques of comparable precision. The level of agreement found is consistent with the expected accuracy of the technique, even though the astrometric parameters used are from preliminary reductions of the data for both techniques. The Hipparcos reference frame has been aligned with a quasi-FK5 frame in the process of its construction. The magnitudes of the rotation angles found are consistent with the degree of alignment known between the VLBI and FK5 frames. This VLBI link of the Hipparcos catalog is preliminary and we describe various improvements that will be implemented before the release of the Hipparcos catalog in 1996. Comparison of the VLBI and Hipparcos trigonometric parallaxes are also discussed. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. MIT, HAYSTACK OBSERV, WESTFORD, MA 01886 USA. CTR ETUD & RECH GEODYNAM & ASTRON, F-06130 GRASSE, FRANCE. LUND OBSERV, S-22100 LUND, SWEDEN. ASTRON RECH INST, D-69120 HEIDELBERG, GERMANY. USN OBSERV, CODE TSEO, WASHINGTON, DC 20392 USA. UNIV CALGARY, DEPT PHYS & ASTRON, CALGARY, AB T2N 1N4, CANADA. RP LESTRADE, JF (reprint author), OBSERV PARIS, CNRS, ARPEGES URA 1757, F-92195 MEUDON, FRANCE. OI Eubanks, Thomas Marshall/0000-0001-9543-0414 NR 23 TC 36 Z9 36 U1 0 U2 2 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC 1 PY 1995 VL 304 IS 1 BP 182 EP 188 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH307 UT WOS:A1995TH30700028 ER PT J AU SEKANINA, Z AF SEKANINA, Z TI EVIDENCE ON SIZES AND FRAGMENTATION OF THE NUCLEI OF COMET SHOEMAKER-LEVY-9 FROM HUBBLE-SPACE-TELESCOPE IMAGES SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE COMET SHOEMAKER-LEVY 9; NUCLEAR SIZE; FRAGMENTATION; HUBBLE SPACE TELESCOPE; IMAGE ANALYSIS AB Digital maps of the central regions of 13 nuclear condensations of Comet Shoemaker-Levy 9, obtained with the Wide Field Planetary Camera-2 of the Hubble Space Telescope on January 24-25, March 28-30, and July 4, 1994, were analyzed with the aim to identify the presence of distinct, major fragments in each condensation, to deconvolve their contributions to the signal that also includes the contribution from a surrounding cloud of dust (modeled as an extended source, using two different laws), to estimate the dimensions of the fragments and to study their temporal variations, and to determine the spatial distributions of the fragments as projected onto the plane of the sky. The deconvolution method applied is described, an extensive analysis of the errors involved is presented, and the results are summarized. They include the finding that sizable fragments did survive until the time of atmospheric entry. This result does not contradict evidence of the comet's continuing, apparently spontaneous fragmentation, which still went on long after the extremely close approach to Jupiter in July 1992 and which, because of the Jovian tidal effects, may even have intensified in the final days before the crash on Jupiter. On plausible assumptions regarding the geometric albedo and the phase coefficient, the largest fragments are found to have had effective diameters of similar to 4 km as late as March and even early July 1994. In most condensations, several sizable companions (similar to 1 km or more across) have been detected within similar to 1000 km of the projected location of the brightest fragment, and the surrounding dust cloud has been found to be centered on a point that is shifted in the general direction of the tail, most probably due to effects of solar radiation pressure. RP SEKANINA, Z (reprint author), CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. NR 17 TC 16 Z9 16 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 DEC 1 PY 1995 VL 304 IS 1 BP 296 EP 316 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH307 UT WOS:A1995TH30700038 ER PT J AU SCHARF, CA JAHODA, K BOLDT, E AF SCHARF, CA JAHODA, K BOLDT, E TI ON THE MEASUREMENT OF A COSMOLOGICAL DIPOLE IN THE PHOTON NUMBER COUNTS OF GAMMA-RAY BURSTS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMOLOGY, OBSERVATIONS; GAMMA RAYS, BURSTS; LARGE-SCALE STRUCTURE OF UNIVERSE ID LOCAL GROUP; ACCELERATION; ISOTROPY AB If gamma-ray bursts are cosmological or in a halo distribution their properties are expected to be isotropic (at least to first order). However, our motion with respect to the burst parent population (whose proper frame is expected to be that of the cosmic microwave background [CMB], or that of a static halo) will cause a dipole effect in the distribution of bursts and in their photon number counts (together termed a Compton-Getting effect). We argue that the photon number count information is necessary to distinguish a genuine Compton-Getting effect from some other anisotropy and to fully test the proper-frame isotropy of the bursts. Using Monte Carlo simulations we obtain probability distributions for the statistics of dipole alignment, angular power, and dipole aligned component. We demonstrate the agreement expected between number distribution and photon count distribution dipoles in the presence of noise. It is estimated that of the order of 10(4) bursts would be necessary to constrain a dipole effect of 1%. However, we can test the consistency of number and photon count distributions for a catalog of any size. Using the 2B catalog (Meegan et al. 1994, available in electronic form via ftp from grossc.gsfc.nasa.gov, user name gronews) of bursts observed with the COMPTON/BATSE instrument (Fishman et al. 1989) (in the energy band 20-50 keV), and the dipole determined from the CMB, we find the surprising result that although the number-weighted distribution is consistent with isotropy, the fluence-weighted dipole has a correlation with the CMB dipole that has a probability of occurring only 10% of the time for an isotropic photon distribution. Furthermore, the photon and number dipoles are inconsistent under the hypothesis of isotropy, at the 2 sigma level. Taken together this could be an indication that a nonnegligible fraction of gamma-ray bursts originate in the local, anisotropic universe. These results suggest that future analyses of the angular distribution of gamma-ray bursts should include both photon count and number weighting and that larger catalogs should be used to test the robustness of the apparent inconsistency with isotropy found here. RP SCHARF, CA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 666,GREENBELT,MD 20771, USA. RI Jahoda, Keith/D-5616-2012 NR 17 TC 5 Z9 5 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1995 VL 454 IS 2 BP 573 EP 579 DI 10.1086/176510 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF088 UT WOS:A1995TF08800004 ER PT J AU MALLOZZI, RS PACIESAS, WS PENDLETON, GN BRIGGS, MS PREECE, RD MEEGAN, CA FISHMAN, GJ AF MALLOZZI, RS PACIESAS, WS PENDLETON, GN BRIGGS, MS PREECE, RD MEEGAN, CA FISHMAN, GJ TI THE NU-F-NU PEAK ENERGY-DISTRIBUTIONS OF GAMMA-RAY BURSTS OBSERVED BY BATSE SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMOLOGY, OBSERVATIONS; GAMMA RAYS, BURSTS ID ORIGIN AB The majority of gamma-ray bursts exhibit a peak in their nu F-nu photon energy spectra at an energy E(p) that is in the range of similar to 20-2000 keV available to the Large Area Detectors of the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. If gamma-ray burst sources are at cosmological distances (d greater than or similar to 1 Gpc), then the spectra of dim bursts should be redshifted to lower energies relative to those of bright bursts. The magnitude of the shift is a function of the cosmological redshifts z of both the dim and bright burst sources and hence yields the range of redshift available to the bursts; this range is further constrained by considering cosmological model fits to the burst number-intensity distribution. We have produced photon energy spectra for similar to 400 bursts using data from BATSE to investigate if this expected shift in the nu F-nu peak is observed. We find that the mean peak energies of the burst spectra are correlated with intensity: lower intensity groups of burst spectra exhibit a lower average peak energy, although the distributions of E(p) are quite wide. Denoting the redshift of an event with an observed peak photon flux P (photons cm(-2) s(-1)) by z(P), we find that the maximum range consistent with the bursts of our sample is (1 + z(1))/(1 + z(100)) = 1.86(+0.24)(+0.36). C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP MALLOZZI, RS (reprint author), UNIV ALABAMA,DEPT PHYS,HUNTSVILLE,AL 35899, USA. NR 28 TC 137 Z9 137 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1995 VL 454 IS 2 BP 597 EP 603 DI 10.1086/176513 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF088 UT WOS:A1995TF08800007 ER PT J AU VENTURI, T CASTALDINI, C COTTON, WD FERETTI, L GIOVANNINI, G LARA, L MARCAIDE, JM WEHRLE, AE AF VENTURI, T CASTALDINI, C COTTON, WD FERETTI, L GIOVANNINI, G LARA, L MARCAIDE, JM WEHRLE, AE TI VLBI OBSERVATIONS OF A COMPLETE SAMPLE OF RADIO GALAXIES .6. THE 2 FR-I RADIO GALAXIES B2-0836+29 AND 3C-465 SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, INDIVIDUAL (B2 0836+29, 3C 465); GALAXIES, JETS; GALAXIES, STRUCTURE; RADIO CONTINUUM, GALAXIES; TECHNIQUES, INTERFEROMETRIC ID VLA OBSERVATIONS; ABELL CLUSTERS; NUCLEI; 3C-465 AB We present 5 GHz global VLBI observations of the two Fanaroff-Riley type I radio galaxies B2 0836 + 29 and 3C 465 (2335 + 26). For 3C 465 we present also 1.7 GHz and 8.4 GHz global VLBI data. In addition VLA observations were used to obtain arcsecond-resolution continuum and polarization maps at 5 GHz. Both sources are very asymmetric on the parsec scale, with a core and a one-sided jet, aligned with the main arcsecond-scale jet. We place a limit on the milliarcsecond jet-to-counterjet brightness ratio B-jet/B-ejet greater than or similar to 20 and greater than or similar to 30 for B2 0836 + 29 and 3C 465, respectively. For 3C 465 the strong asymmetry holds to the kiloparsec scale. The brightness asymmetry and the ratio between the core radio power and total radio power allow us to constrain the jet velocity close to the core and the orientation of the radio structure with respect to the line of sight. The results suggest that the plasma speed is relativistic on the parsec scale for both sources, i.e., v(jet) greater than or similar to 0.75c for B2 0836 + 29 and v(jet) greater than or similar to 0.6c for 3C 465. While v(jet) decreases from the parsec to the kiloparsec scale in B2 0836 + 29, in 3C 465 the very high v(jet) holds all the way to the kiloparsec bright spot. Our results are in agreement with the unification scheme suggestion that FR I radio galaxies are the unbeamed population of BL Lac objects. Furthermore, they reinforce the idea that the central engine in FR I and FR II radio galaxies must be qualitatively similar. The different radio morphology could then be due either to an intrinsically different nuclear power, which affects the torus geometry, or to different conditions in the region beyond the parsec scale, where a significant deceleration in the FR I jets occurs. C1 UNIV BOLOGNA,DIPARTMENTO ASTRON,I-40133 BOLOGNA,ITALY. NATL RADIO ASTRON OBSERV,CHARLOTTESVILLE,VA 22903. CSIS,INST ASTROFIS ANDALUCIA,E-18080 GRANADA,SPAIN. UNIV VALENCIA,DEPT ASTRON,E-46100 BURJASSOT,SPAIN. CALTECH,JET PROP LAB,CTR INFRARED PROC & ANAL,PASADENA,CA 91125. RP VENTURI, T (reprint author), CNR,IST RADIOASTRON,VIA GOBERTI 101,I-40129 BOLOGNA,ITALY. OI Feretti, Luigina/0000-0003-0312-6285; Venturi, Tiziana/0000-0002-8476-6307 NR 37 TC 29 Z9 29 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1995 VL 454 IS 2 BP 735 EP 744 DI 10.1086/176525 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF088 UT WOS:A1995TF08800019 ER PT J AU OMONT, A MOSELEY, SH COX, P GLACCUM, W CASEY, S FORVEILLE, T CHAN, KW SZCZERBA, R LOEWENSTEIN, RF HARVEY, PM KWOK, S AF OMONT, A MOSELEY, SH COX, P GLACCUM, W CASEY, S FORVEILLE, T CHAN, KW SZCZERBA, R LOEWENSTEIN, RF HARVEY, PM KWOK, S TI THE 30 MICRON EMISSION BAND IN CARBON-RICH PREPLANETARY NEBULAE SO ASTROPHYSICAL JOURNAL LA English DT Article DE CIRCUMSTELLAR MATTER; DUST, EXTINCTION; INFRARED, STARS; PLANETARY NEBULAE, GENERAL STARS, AGB AND POST-AGB; STARS, CARBON ID CIRCUMSTELLAR SHELLS; OPTICAL-PROPERTIES; INFRARED-SPECTRA; DUST; FEATURES; STARS AB The 16-48 mu m spectra of five carbon-rich post-AGE objects (pre-planetary nebulae, PPNs) known to have an unidentified 21 mu m emission feature in their IRAS LRS spectra have been obtained using the Kuiper Airborne Observatory. A broad emission band extending from 24 to similar to 45 mu m is present in the spectra of these objects. Peaking at similar to 30 mu m, the intensity of the band is variable from source to source, accounting in one case (IRAS 22272 + 5435) for similar to 20% of its bolometric luminosity. However, its strength is not correlated with that of the 21 mu m feature. The 30 mu m band is similar to the feature previously found in other carbon-rich AGB stars and planetary nebulae. It is thus seen in a wide variety of objects, while the 21 mu m band is seen only in a subset of PPNs. It was suggested for AGE stars that the 30 mu m band could be carried by solid MgS particles. The observed 30 mu m emission is modeled combining distributions of carbon grains and MgS grains. The required MgS abundance with respect to H nuclei is roughly estimated to be less than similar to 7 x 10(-6) i.e., representing about 50% and 25% of the total abundances of S and Mg, respectively. Despite the relatively good fit with MgS, the possibility of alternative models especially with carbon-related compounds should still be addressed. C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. OBSERV MARSEILLE,F-13248 MARSEILLE 04,FRANCE. MAX PLANCK INST RADIOASTRON,W-5300 BONN,GERMANY. APPL RES CORP,LANDOVER,MD 20785. UNIV GRENOBLE 1,OBSERV GRENOBLE,F-38041 GRENOBLE,FRANCE. CNRS,F-38041 GRENOBLE,FRANCE. UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742. UNIV CALGARY,DEPT PHYS & ASTRON,CALGARY,AB T2N 1N4,CANADA. INST ASTROPHYS PARIS,PARIS,FRANCE. UNIV CHICAGO,YERKES OBSERV,WILLIAMS BAY,WI 53191. UNIV TEXAS,DEPT ASTRON,AUSTIN,TX 78712. RP OMONT, A (reprint author), CNRS,INST ASTROPHYS PARIS,98 BIS BD ARAGO,F-75014 PARIS,FRANCE. RI Kwok, Sun/D-3080-2009; Moseley, Harvey/D-5069-2012 OI Kwok, Sun/0000-0001-7708-081X; NR 43 TC 74 Z9 75 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1995 VL 454 IS 2 BP 819 EP 825 DI 10.1086/176534 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF088 UT WOS:A1995TF08800028 ER PT J AU PRAVDO, SH DAY, CSR ANGELINI, L HARMON, BA YOSHIDA, A SARASWAT, P AF PRAVDO, SH DAY, CSR ANGELINI, L HARMON, BA YOSHIDA, A SARASWAT, P TI ASCA AND GRO OBSERVATIONS OF GX-301-2 SO ASTROPHYSICAL JOURNAL LA English DT Article DE GAMMA RAYS, OBSERVATIONS; PULSARS, INDIVIDUAL (GX 301 - 2); X-RAYS, STARS ID X-RAY SOURCES; STELLAR WIND; H-ALPHA; ACCRETION; GX301-2; PERIOD; STARS; BINARIES; GX-301-2; EMISSION AB We observed the X-ray binary pulsar GX 301-2 with ASCA (Astro-D) on 1994 February 13-14 at orbital phase similar to 0.3, when the X-ray emission is in a nonflaring state. We also obtained BATSE/GRO observations of the total high-energy flux concurrent with the ASCA observation, as well as before and after. The BATSE data cover 7.5 orbital periods from 1993 September 20 to 1994 July 28. We folded these data over the orbital period and found that the preperiastron (PP) flare is asymmetric-it rises more slowly than it falls. We also detected a periodic near-apastron (NA) flare. Both the asymmetry of the PP flare and the existence of the NA flare can be explained by an equatorially enhanced stellar wind or a circumstellar disk around the optical companion WRA 977 that GX 301-2 crosses twice per orbit. We measured the GX 301-2 pulse period to be 675.7 +/- 0.1 s, the lowest value observed to date. This demonstrates that the spin-up that started in 1984 continues and is the longest lasting secular spin-up of the known pulsars. The secular spin-up indicates that an accretion disk has formed. The appearance of the NA flare may be related to the secular spin-up if the circumstellar disk also provides a steady source of angular momentum to the neutron star. The ASCA Gas Imaging Spectrometer (GIS) and Solid-state Imaging Spectrometer (SIS) images indicate the presence of two previously unknown soft X-ray sources 3' and 8' from GX 301-2. The brighter source at 8' we identify as a dMe star. Both sources have contributed to prior observations of the low-energy GX 301-2 spectrum. We have combined the nearly simultaneous spectral data from ASCA and BATSE to determine the pulse-phase-averaged 4-60 keV spectrum of GX 301-2. It fits a power-law model with low energy absorption, a narrow iron emission line, an iron absorption edge, and a high-energy cutoff. We measured the SIS0/ASCA iron line energy to be 6.41 +/- 0.02 keV, the energy for neutral iron or with an ionization state no higher than Fe XVII. The iron line equivalent width is 230 +/- 30 eV, with 43 eV < intrinsic width <74 eV (90% confidence). The iron edge is at 7.19 +/- 0.03 keV. The line and edge energies are consistent with the same iron ionization state if the state is no higher than Fe V. C1 NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. INST PHYS & CHEM RES,WAKO,SAITAMA 35101,JAPAN. RP PRAVDO, SH (reprint author), CALTECH,JET PROP LAB,MSIL STOP 306-431,PASADENA,CA 91109, USA. NR 40 TC 37 Z9 37 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1995 VL 454 IS 2 BP 872 EP 879 DI 10.1086/176540 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF088 UT WOS:A1995TF08800034 ER PT J AU CANNIZZO, JK CHEN, W LIVIO, M AF CANNIZZO, JK CHEN, W LIVIO, M TI THE ACCRETION DISK LIMIT-CYCLE INSTABILITY IN BLACK-HOLE X-RAY BINARIES SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCRETION, ACCRETION DISKS; BLACK HOLE PHYSICS; X-RAYS, STARS ID DWARF NOVAE; CATACLYSMIC VARIABLES; THERMAL-INSTABILITY; TRANSITION FRONTS; GALACTIC NUCLEI; MODEL; EVOLUTION; OUTBURSTS; TRANSIENTS; A0620-00 AB We investigate the operation of the limit cycle mechanism in accretion disks around similar to 10 M. black holes. We explore a regime of parameter space relevant to these systems, and delineate a range of possible behaviors by testing the response of our one-dimensional, time-dependent, hydrodynamic model to variations in each of the control parameters in the theory. These parameters are the number of radial grid points N, the accretor mass M(1), the inner disk radius r(inner), the outer disk radius r(outer), the mass transfer rate into the outer disk from the secondary star M(T), and the accretion disk viscosity parameter alpha-parameterized in separate computations both in terms of radius (including a step function between low and high states) and in terms of local aspect ratio h/r. For the class of models in which alpha is taken to vary in a step function between the two stable branches of accretion, we find a tendency for the outbursts to exhibit faster-than-exponential decays, in contrast to the observations. This behavior cannot be substantially affected by taking alpha to vary with radius-alpha proportional to r(epsilon)-as in previous works, nor is it affected by the numerical resolution. Models in which alpha is a function of the local aspect ratio h/r can produce robustly exponential decays as observed if alpha proportional to (h/r)(n), where n = 1.5. This critical value for n is independent of the primary mass, unlike the critical epsilon value in the r(epsilon) scaling. Numerically, we find that the transition front width is equal to the geometric average of h and r. (It is this fact that leads to the critical value n = 1.5 for exponential decay.) Previous studies have lacked the numerical resolution to make this determination, and in fact the specific results presented in earlier papers were probably severely compromised by grid spacing limitations. Finally, for models in which the decay is produced by accretion onto the central object rather than by the action of a cooling front, we require n = -2 for exponential decays. C1 SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218. RP CANNIZZO, JK (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,CODE 666,GREENBELT,MD 20771, USA. NR 76 TC 85 Z9 85 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1995 VL 454 IS 2 BP 880 EP 894 DI 10.1086/176541 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF088 UT WOS:A1995TF08800035 ER PT J AU VESTRAND, WT STACY, JG SREEKUMAR, P AF VESTRAND, WT STACY, JG SREEKUMAR, P TI HIGH-ENERGY GAMMA-RAYS FROM THE BL-LACERTAE OBJECT PKS-2155-304 SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL LACERTAE OBJECTS, INDIVIDUAL (PKS 2155-304); GAMMA RAYS, OBSERVATIONS ID X-RAY; SPECTRAL VARIABILITY; PKS-2155-304 AB We present the first detection of gamma-ray emission from the extragalactic source PKS 2155-304, which is often considered to be a prototype of X-ray-selected BL Lacertae objects. The 30 MeV-10 GeV photon spectrum derived from measurements taken with EGRET on the Compton Observatory during 1994 November 15-29 indicates a very hard spectrum with a power-law spectral index of 1.71 +/- 0.24. This spectral hardness when combined with the proximity of the source (z = 0.116) makes it an excellent candidate for detection at TeV gamma-ray energies. We briefly discuss the implications of these gamma-ray measurements for models of BL Lac objects. C1 NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,USRA,GREENBELT,MD 20771. RP VESTRAND, WT (reprint author), UNIV NEW HAMPSHIRE,CTR SPACE SCI,DURHAM,NH 03824, USA. NR 26 TC 55 Z9 55 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1995 VL 454 IS 2 BP L93 EP L96 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF089 UT WOS:A1995TF08900006 ER PT J AU WAGNER, SJ MATTOX, JR HOPP, U BOCK, H HEIDT, J BERTSCH, DL DINGUS, BL FICHTEL, CE HARTMAN, RC HUNTER, SD KANBACH, G KNIFFEN, DA LIN, YC MAYERHASSELWANDER, HA MICHELSON, PF VONMONTIGNY, C NOLAN, PL SREEKUMAR, P THOMPSON, DJ AF WAGNER, SJ MATTOX, JR HOPP, U BOCK, H HEIDT, J BERTSCH, DL DINGUS, BL FICHTEL, CE HARTMAN, RC HUNTER, SD KANBACH, G KNIFFEN, DA LIN, YC MAYERHASSELWANDER, HA MICHELSON, PF VONMONTIGNY, C NOLAN, PL SREEKUMAR, P THOMPSON, DJ TI HIGH-ENERGY GAMMA-RAYS FROM PKS-1406-076 AND THE OBSERVATION OF CORRELATED GAMMA-RAY AND OPTICAL-EMISSION SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, ACTIVE; GALAXIES, JETS; GAMMA RAYS, OBSERVATIONS; GAMMA RAYS, THEORY; QUASARS, INDIVIDUAL (PKS 1406 -076); RADIATION MECHANISMS, NONTHERMAL ID EXTRAGALACTIC RADIO-SOURCES; JET AB We report simultaneous observations of the optically violent variable (OVV) quasar PKS 1406-076 in the optical and gamma-ray regime. Gamma-ray emission is detected with very high significance. Both the gamma-ray and optical properties of PKS 1406-076 are typical for the group of gamma-bright active galactic nuclei detected by EGRET. During 1993 January the source was unusually bright in both frequency ranges. During this period we observed a rapid, symmetrical flare in the optical wavelength range which lasted for about 4 days. EGRET detected a similar rapid flare peaking about 22 hr after the optical outburst. Because such rapid flares are rare events, it is likely that the outbursts in the two frequency regimes are correlated. Correlated outbursts with similar profiles and a lag between the optical and gamma-ray maxima of 22 hr are inconsistent with simple versions of models suggested for the emission of high-energy radiation from blazars. C1 UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV SPACE RES ASSOC,ASTROPHYS PROGRAM,WASHINGTON,DC. MAX PLANCK INST ASTRON,D-69117 HEIDELBERG,GERMANY. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. MPE,D-85740 GARCHING,GERMANY. HAMPDEN SYDNEY COLL,HAMPDEN SYDNEY,VA 23943. STANFORD UNIV,WW HANSEN EXPTL PHYS LAB,STANFORD,CA 94305. RP WAGNER, SJ (reprint author), LANDESSTERNWARTE HEIDELBERG KONIGSTUHL,D-69117 HEIDELBERG,GERMANY. RI Nolan, Patrick/A-5582-2009; Hunter, Stanley/D-2942-2012; Thompson, David/D-2939-2012 OI Thompson, David/0000-0001-5217-9135 NR 22 TC 47 Z9 47 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 1995 VL 454 IS 2 BP L97 EP L100 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF089 UT WOS:A1995TF08900007 ER PT J AU THOMPSON, DJ BERTSCH, DL DINGUS, BL ESPOSITO, JA ETIENNE, A FICHTEL, CE FRIEDLANDER, DP HARTMAN, RC HUNTER, SD KENDIG, DJ MATTOX, JR MCDONALD, LM VONMONTIGNY, C MUKHERJEE, R RAMANAMURTHY, PV SREEKUMAR, P FIERRO, JM LIN, YC MICHELSON, PF NOLAN, PL SHRIVER, SK WILLIS, TD KANBACH, G MAYERHASSELWANDER, HA MERCK, M RADECKE, HD KNIFFEN, DA SCHNEID, EJ AF THOMPSON, DJ BERTSCH, DL DINGUS, BL ESPOSITO, JA ETIENNE, A FICHTEL, CE FRIEDLANDER, DP HARTMAN, RC HUNTER, SD KENDIG, DJ MATTOX, JR MCDONALD, LM VONMONTIGNY, C MUKHERJEE, R RAMANAMURTHY, PV SREEKUMAR, P FIERRO, JM LIN, YC MICHELSON, PF NOLAN, PL SHRIVER, SK WILLIS, TD KANBACH, G MAYERHASSELWANDER, HA MERCK, M RADECKE, HD KNIFFEN, DA SCHNEID, EJ TI THE 2ND EGRET CATALOG OF HIGH-ENERGY GAMMA-RAY SOURCES SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE CATALOGS; DIFFUSE RADIATION; GAMMA RAYS, OBSERVATIONS; METHODS, DATA ANALYSIS ID LARGE MAGELLANIC CLOUD; COSMIC-RAY; MILKY-WAY; TELESCOPE; COMPTON; RADIATION; EMISSION; 3C-279; PULSAR; GRO AB The second catalog of high-energy gamma-ray observations from the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory, includes data from phase 1 (1991 April-1992 November) and phase 2 (1992 November-1993 September) of the mission. In addition to including more data than the first EGRET catalog, this catalog uses an improved model of the diffuse Galactic gamma radiation. The 129 sources in the catalog include one solar flare bright enough to be detected as a source, the Large Magellanic Cloud, five pulsars, 40 high-confidence identifications of active galactic nuclei (AGNs), II AGN identifications with lower confidence, and 71 sources not yet identified with known objects. Also included are approximate upper limits for gamma-ray sources at any point in the sky and information about sources listed in the first EGRET catalog but not appearing in this one. C1 STANFORD UNIV,WW HANSEN EXPTL PHYS LAB,STANFORD,CA 94305. STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. MAX PLANCK INST EXTRATERR PHYS,D-85748 GARCHING,GERMANY. HAMPDEN SYDNEY COLL,DEPT PHYS,HAMPDEN SYDNEY,VA 23943. GRUMMAN AEROSP CORP,BETHPAGE,NY 11714. RP THOMPSON, DJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 662,GREENBELT,MD 20771, USA. RI Nolan, Patrick/A-5582-2009; Hunter, Stanley/D-2942-2012; Thompson, David/D-2939-2012; OI Thompson, David/0000-0001-5217-9135; Dingus, Brenda/0000-0001-8451-7450 NR 58 TC 413 Z9 421 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 1995 VL 101 IS 2 BP 259 EP 286 DI 10.1086/192240 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF256 UT WOS:A1995TF25600002 ER PT J AU LIU, XM AHMED, SM MULTARI, RA JAMES, GK AJELLO, JM AF LIU, XM AHMED, SM MULTARI, RA JAMES, GK AJELLO, JM TI HIGH-RESOLUTION ELECTRON-IMPACT STUDY OF THE FAR-ULTRAVIOLET EMISSION-SPECTRUM OF MOLECULAR-HYDROGEN SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE METHODS, LABORATORY; MOLECULAR PROCESSES; ULTRAVIOLET, ISM ID EXTREME-ULTRAVIOLET; H-2 MOLECULE; BAND SYSTEMS; WERNER BANDS; RYDBERG SERIES; CROSS-SECTION; LYMAN; STATES; H2; TRANSITION AB The emission spectrum of molecular hydrogen produced by electron-impact excitation at 100 eV has been measured in the wavelength range 1140-1690 Angstrom. High-resolution, optically thin spectra (Delta lambda = 0.136 Angstrom) of the far-ultraviolet( FUV) Lyman and Werner band systems have been obtained with a newly constructed 3 m spectrometer. Synthetic spectral intensities based on the transition probabilities calculated by Abgrall et al. are in very good agreement with experimentally observed intensities. Previous modeling that utilized Allison & Dalgarno band transition probabilities with Honl-London factors breaks down when the transition moment has significant J dependence or when re-vibrational coupling is significant. Ro-vibrational perturbation between v = 14 of the B (1) Sigma(u)(+) state and v = 3 of the C (1) Pi(u), state and the rotational dependence of the transition moment in the (6, 12) and (7, 13) bands of the Lyman system are examined. Complete high-resolution experimental reference FUV spectra, together with the model synthetic spectra based on the Abgrall transition probabilities, are presented. An improved calibration standard is obtained, and an accurate calibration of the 3 m spectrometer has been achieved. RP LIU, XM (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 49 TC 63 Z9 63 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 1995 VL 101 IS 2 BP 375 EP 399 DI 10.1086/192246 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TF256 UT WOS:A1995TF25600008 ER PT J AU Russell, GL Miller, JR Rind, D AF Russell, GL Miller, JR Rind, D TI A coupled atmosphere-ocean model for transient climate change studies SO ATMOSPHERE-OCEAN LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; GENERAL-CIRCULATION MODELS; GRADUAL CHANGES; WORLD OCEAN; SEA ICE; TRANSPORT; VARIABILITY; CO2; WATER; IRRADIANCE AB A new coupled atmosphere-ocean model has been developed for climate predictions at decade to century scales. The atmospheric model is similar to that of Hansen et al. (1983) except that the atmospheric dynamic equations for mass and momentum are solved using Arakawa and Lamb's (1977) C grid scheme and the advection of potential enthalpy and water vapour uses the linear upstream scheme (Russell and Lerner, 1981). The new global ocean model conserves mass, allows for divergent flow, has a free surface and uses the linear upstream scheme for the advection of potential enthalpy and salt Both models run at 4 degrees x 5 degrees resolution, with 9 vertical layers for the atmosphere and 13 layers for the ocean. Twelve straits are included allowing for subgrid-scale water flow Runoff from land is routed into appropriate ocean basins. Atmospheric and oceanic surface fluxes are of opposite sign and are applied synchronously. Flux adjustments are not used. Except for partial strength alternating binomial filters (Shapiro, 1970), which are applied to the momentum components in the atmosphere and oceans, there is no explicit horizontal diffusion. A 120-year simulation of the coupled model starting from the oceanic initial conditions of Levitus (1982) is discussed. The model dynamics stabilize after several decades. The maximum northward ocean heat flux is 1.4 x 10(15) W at 16 degrees N. The model appears to maintain the vertical gradients characterizing the separation between the upper and deep ocean spheres. Inadequacies in the coupled model simulation lead to decreasing temperature and salinity in the high latitude North Atlantic and to a poor simulation of the northern North Atlantic thermohaline circulation. The mass transport of the Gulf Stream is about half of observed values, while the transports of the Kuroshio and Antarctic Circumpolar Currents are similar to observations. Additional deficiencies include a climate drift in the surface air temperature of 0.006 degrees C year(-1) due to a radiation imbalance of 7.4 Wm(-2) at the top of the atmosphere and too warm temperatures in the eastern portions of tropical oceans. The coupled model should be useful for delineating modelling capabilities without the use of flux adjustments and should serve as a benchmark for future model improvements. RP Russell, GL (reprint author), NASA,GODDARD SPACE FLIGHT CTR,INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA. NR 67 TC 227 Z9 231 U1 1 U2 11 PU CANADIAN METEOROLOGICAL OCEANOGRAPHIC SOC PI OTTAWA PA 150 LOUIS PASTEUR PVT., STE 112, MCDONALD BUILDING, OTTAWA ON K1N 6N5, CANADA SN 0705-5900 J9 ATMOS OCEAN JI Atmos.-Ocean PD DEC PY 1995 VL 33 IS 4 BP 683 EP 730 PG 48 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA UH174 UT WOS:A1995UH17400003 ER PT J AU LEBLANC, A ROWE, R SCHNEIDER, V EVANS, H HEDRICK, T AF LEBLANC, A ROWE, R SCHNEIDER, V EVANS, H HEDRICK, T TI REGIONAL MUSCLE LOSS AFTER SHORT-DURATION SPACEFLIGHT SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article ID BED REST; SUSPENSION; ATROPHY; RAT AB Background: Muscle strength and limb girth measurements during Skylab and Apollo missions suggested that loss of muscle mass may occur as a result of spaceflight. Extended duration spaceflight is important for the economical and practical use of space. The loss of muscle mass during spaceflight is a medical concern for long duration flights to the planets or extended stays aboard space stations. Understanding the extent and temporal relationships of muscle loss is important for the development of effective spaceflight countermeasures. Hypothesis: We hypothesized that significant and measurable changes in muscle volume would occur in Shuttle crewmembers following 8 d of weightlessness. Methods: MRI was used to obtain the muscle volumes of the calf, thigh and lower back before and after the STS-47 Shuttle mission. Results: Statistical analyses demonstrated that the soleus-gastrocnemius (-6.3%), anterior calf (-3.9%), hamstrings (-8.3%), quadriceps (-6.0%) and intrinsic back (-10.3%) muscles were decreased, p < 0.05, compared to baseline, 24 h after landing. At 2 weeks post recovery, the hamstrings and intrinsic lower back muscles were still below baseline, p < 0.05. Conclusions: These results demonstrate that even short duration spaceflight can result in significant muscle atrophy. C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. KRUG LIFE SCI,HOUSTON,TX. RP LEBLANC, A (reprint author), BAYLOR COLL MED,6501 FANNIN ST,SUITE NB1-004,HOUSTON,TX 77030, USA. NR 25 TC 140 Z9 144 U1 0 U2 7 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD DEC PY 1995 VL 66 IS 12 BP 1151 EP 1154 PG 4 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA TG912 UT WOS:A1995TG91200004 PM 8747608 ER PT J AU GREENLEAF, JE KRUK, B NAZAR, K FALECKAWIECZOREK, I KACIUBAUSCILKO, H AF GREENLEAF, JE KRUK, B NAZAR, K FALECKAWIECZOREK, I KACIUBAUSCILKO, H TI GLUCOSE-INFUSION INTO EXERCISING DOGS AFTER CONFINEMENT - RECTAL AND ACTIVE MUSCLE TEMPERATURES SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article AB Background: Intravenous glucose infusion into ambulatory dogs results in attenuation of exercise-induced increase of both rectal and thigh muscle temperatures. Hypothesis: That glucose (Glu) infusion attenuates excessive increase in body temperature from restricted activity during confinement deconditioning. Methods: Rectal (Tre) and quadriceps femoris muscle (Tmu) temperatures, metabolic rate, and blood samples were taken before and after 90 min of moderate treadmill exercise ((X) over bar = 3.1 +/- SE 0.2 W . kg(-1)) at Tdb = 21 +/- 1 degrees C and 45-60% rh from 7 male mongrel dogs (19.6 +/- SD 3.0 kg) with i.v. infusion of 40% Glu in 0.9% NaCl (0.07 ml . kg(-1). min(-1)) or 0.9% NaCl (0.07 mg . g(-1). min(-1)) both before and after a weeks of cage confinement. Results: Mean (+/- SE) Delta Tre (90-0 min) were: NaCl . after = 1.8 +/- 0.4 degrees C vs. 1.4 +/- 0.3 degrees C (NS) before confinement; Glu . after = 1.3 +/- 0.2 degrees C vs. 0.9 +/- 0.3 degrees C (p < 0.02) before confinement. Comparable Delta Tmu (90-0 min) data were: NaCl . after = 2.5 +/- 0.4 degrees C vs. 1.9 +/- 0.4 degrees C (NS) before; Glu . after = 1.6 +/- 0.2 degrees C vs. 1.4 +/- 0.4 degrees C (NS) before. Glucose infusion significantly attenuated the rise of Tmu (1.9 degrees vs. 1.4 degrees C) only before confinement, but attenuated the rise of Tre both before (1.4 degrees vs. 0.9 degrees C) and after (1.8 degrees vs. 1.3 degrees C) confinement. Body temperature attenuation was not related to change in plasma volume, osmolality, [Glu], [lactate], [cortisol], or heat production with constant VO(2). Conclusion: Intravenous glucose infusion attenuates the rise in exercise core temperature in deconditioned dogs by a yet undefined mechanism. C1 POLISH ACAD SCI, MED RES CTR, DEPT APPL PHYSIOL, WARSAW, POLAND. RP GREENLEAF, JE (reprint author), NASA, AMES RES CTR, DIV LIFE SCI 23911, HUMAN ENVIRONM PHYSIOL LAB, MOFFETT FIELD, CA 94035 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD DEC PY 1995 VL 66 IS 12 BP 1169 EP 1174 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA TG912 UT WOS:A1995TG91200007 PM 8747611 ER PT J AU Read, WG Waters, JW Flower, DA Froidevaux, L Jarnot, RF Hartmann, DL Harwood, RS Rood, RB AF Read, WG Waters, JW Flower, DA Froidevaux, L Jarnot, RF Hartmann, DL Harwood, RS Rood, RB TI Upper-tropospheric water vapor from UARS MLS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID ATMOSPHERE RESEARCH SATELLITE; MICROWAVE LIMB SOUNDER; RELATIVE-HUMIDITY; TEMPERATURES; CLIMATOLOGY; ABSORPTION; FEEDBACK; SPECTRUM; MODELS; CLOUDS AB Initial results of upper-tropospheric water vapor obtained from the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) are presented. MLS is less affected by clouds than infrared or visible techniques, and the UARS orbit provides daily humidity monitoring for approximately two-thirds of the earth. Best results are currently obtained when water vapor abundances are approximately 100-300 ppmv, corresponding to approximately 12-km height in the Tropics and 7 km at high latitudes. The observed latitude variation of water vapor at 215 hPa is in good agreement with the U.K. Universities's Global Atmospheric Modelling Project model. The ability to observe synoptic-scale features associated with tropopause height variations is clearly illustrated by comparison with the National Aeronautics and Space Administration Goddard Space Flight Center assimilation model. Humidity detrainment streams extending from tropical convective regions are also observed. C1 UNIV WASHINGTON, SEATTLE, WA 98195 USA. UNIV EDINBURGH, EDINBURGH EH8 9YL, MIDLOTHIAN, SCOTLAND. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RP Read, WG (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, MAIL STOP 183-701, PASADENA, CA 91109 USA. RI Rood, Richard/C-5611-2008 OI Rood, Richard/0000-0002-2310-4262 NR 37 TC 64 Z9 64 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 EI 1520-0477 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1995 VL 76 IS 12 BP 2381 EP 2389 DI 10.1175/1520-0477(1995)076<2381:UTWVFM>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TM241 UT WOS:A1995TM24100001 ER PT J AU Lau, KM Weng, H AF Lau, KM Weng, H TI Climate signal detection using wavelet transform: How to make a time series sing SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID OSCILLATIONS; EVOLUTION; LENGTH AB In this paper, the application of the wavelet transform (WT) to climate time series analyses is introduced. A tutorial description of the basic concept of WT, compared with similar concepts used in music, is also provided. Using an analogy between WT representation of a time series and a music score, the authors illustrate the importance of local versus global information in the time-frequency localization of climate signals. Examples of WT applied to climate data analysis are demonstrated using analytic signals as well as real climate time series. Results of WT applied to two climate time series-that is, a proxy paleoclimate time series with a 2.5-Myr deep-sea sediment record of delta(18)O and a 140-yr monthly record of Northern Hemisphere surface temperature-are presented. The former shows the presence of a 40-kyr and a 100-kyr oscillation and an abrupt transition in the oscillation regime at 0.7 Myr before the present, consistent with previous studies. The latter possesses a myriad of oscillatory modes from interannual (2-5 yr), interdecadal (10-12 yr, 20-25 yr, and 40-60 yr), and century (similar to 180 yr) scales at different periods of the data record. In spite of the large difference in timescales, common features in time-frequency characteristics of these two time series have been identified. These features suggest that the variations of the earth's climate; are consistent with those exhibited by a nonlinear dynamical system under external forcings. RP Lau, KM (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ATMOSPHERES LAB, CODE 913, GREENBELT, MD 20771 USA. RI Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 32 TC 389 Z9 421 U1 4 U2 44 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 1995 VL 76 IS 12 BP 2391 EP 2402 DI 10.1175/1520-0477(1995)076<2391:CSDUWT>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TM241 UT WOS:A1995TM24100002 ER PT J AU Bigelow, KA Jones, JT DiNardo, GT AF Bigelow, KA Jones, JT DiNardo, GT TI Growth of the Pacific pomfret, Brama japonica: A comparison between otolith and length-frequency (MULTIFAN) analysis SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID PARAMETERS AB Age and growth of the Pacific pomfret, Brama japonica, were independently estimated with presumed daily increments within otolith microstructure and MULTIFAN analysis of length-frequency distributions obtained from drift net fisheries. Likelihood ratio tests detected significant differences between sexes and geographic areas in von Bertalanffy parameter estimates from otolith analysis. Otolith interpretations indicated that the species is short lived (age 3+), fast growing (growth coefficient (K) > 1.1), and fully recruited to the North Pacific squid drift net fishery at <1 yr old. Back-calculated hatching dates indicate a protracted spawning period. MULTIFAN models fit the length-frequency data with an assumption of both annual and biannual recruitment. Growth parameter estimates were asymptotic fork length (FL,) = 49.9 cm, K = 0.57 for an annual cohort model, and FL(infinity) = 49.4 cm, K = 1.0 for a biannual cohort model. The growth model derived from otolith increment counts is closer to the MULTIFAN model that assumes biannual length-frequency modes, rather than annual modes. RP Bigelow, KA (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 29 TC 6 Z9 6 U1 0 U2 3 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD DEC PY 1995 VL 52 IS 12 BP 2747 EP 2756 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA UA096 UT WOS:A1995UA09600021 ER PT J AU Hansen, J Rossow, W Carlson, B Lacis, A Travis, L DelGenio, A Fung, I Cairns, B Mishchenko, M Sato, M AF Hansen, J Rossow, W Carlson, B Lacis, A Travis, L DelGenio, A Fung, I Cairns, B Mishchenko, M Sato, M TI Low-cost long-term monitoring of global climate forgings and feedbacks SO CLIMATIC CHANGE LA English DT Article; Proceedings Paper CT International Meeting of Experts on Long-Term Climate Monitoring by the Global Climate Observing System CY JAN 09-11, 1995 CL ASHEVILLE, NC SP WMO, UNESCO, Intergovt Oceanogr Commiss, UNEP, Int Council Sci Union ID GENERAL-CIRCULATION MODELS; MOUNT-PINATUBO ERUPTION; TOTAL OZONE; VOLCANIC AEROSOLS; RADIATION BUDGET; SOLAR-CYCLE; CARBON-DIOXIDE; SATELLITE DATA; TRACE GASES; WATER-VAPOR AB We describe the rationale for long-term monitoring of global climate forcings and radiative feedbacks as a contribution to interpretation of long-term global temperature change. Our discussion is based on a more detailed study and workshop report (Hansen et al., 1993b). We focus on the potential contribution of a proposed series of inexpensive small satellites, but we discuss also the need for complementary climate process studies and ground-based measurements. Some of these measurements could be made inexpensively by students, providing both valuable climate data and science educational experience. RP NASA, GODDARD INST SPACE STUDIES, NEW YORK, NY 10025 USA. RI Lacis, Andrew/D-4658-2012; Carlson, Barbara/D-8319-2012; Del Genio, Anthony/D-4663-2012; Rossow, William/F-3138-2015; Mishchenko, Michael/D-4426-2012; OI Del Genio, Anthony/0000-0001-7450-1359; Cairns, Brian/0000-0002-1980-1022 NR 94 TC 40 Z9 41 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0165-0009 EI 1573-1480 J9 CLIMATIC CHANGE JI Clim. Change PD DEC PY 1995 VL 31 IS 2-4 BP 247 EP 271 DI 10.1007/BF01095149 PG 25 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA TP565 UT WOS:A1995TP56500010 ER PT J AU Rossow, WB Cairns, B AF Rossow, WB Cairns, B TI Monitoring changes of clouds SO CLIMATIC CHANGE LA English DT Article; Proceedings Paper CT International Meeting of Experts on Long-Term Climate Monitoring by the Global Climate Observing System CY JAN 09-11, 1995 CL ASHEVILLE, NC SP WMO, UNESCO, Intergovt Oceanogr Commiss, UNEP, Int Council Sci Union ID RESOLUTION LANDSAT IMAGERY; TIME STOCHASTIC-MODEL; SPATIAL-RESOLUTION; STRUCTURAL CHARACTERISTICS; SATELLITE DATA; CONVECTIVE SYSTEMS; SAMPLING ERRORS; CUMULUS CLOUDS; ATLANTIC-OCEAN; ISCCP AB An analysis of the spatial and temporal scales of cloud variability and their coupling provided by the results from existing cloud observing systems allows us to reach the following conclusions about the necessary attributes of a cloud monitoring system. (1) Complete global coverage with uniform density is necessary to obtain an unbiased estimate of cloud change and an estimate of the reliability with which that change can be determined. (2) A spatial sampling interval of less than 50 km is required so that cloud cover distributions will generally be homogeneous, or statistically homogeneous, within a sample. (3) A sampling frequency of at least six times a day ensures not only that the diurnal and semi-diurnal cycles are not aliased into long term mean values, but also that changes in them can be monitored. (4) Since estimated climate changes are only evident on a decadal time-scale, unless cloud monitoring is continuous with a record length greater than 10 years and has very high precision (approximate to 1%) instrument calibration with overlapping observations between each pair of instruments, it will not be possible either to detect or to diagnose the effects of cloud changes on the climate. C1 COLUMBIA UNIV,NEW YORK,NY 10027. RP Rossow, WB (reprint author), NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025, USA. RI Rossow, William/F-3138-2015; OI Cairns, Brian/0000-0002-1980-1022 NR 76 TC 27 Z9 29 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD DEC PY 1995 VL 31 IS 2-4 BP 305 EP 347 DI 10.1007/BF01095151 PG 43 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA TP565 UT WOS:A1995TP56500012 ER PT J AU Gornitz, V AF Gornitz, V TI Monitoring sea level changes SO CLIMATIC CHANGE LA English DT Article; Proceedings Paper CT International Meeting of Experts on Long-Term Climate Monitoring by the Global Climate Observing System CY JAN 09-11, 1995 CL ASHEVILLE, NC SP WMO, UNESCO, Intergovt Oceanogr Commiss, UNEP, Int Council Sci Union ID VERTICAL CRUSTAL MOVEMENTS; GREENLAND ICE-SHEET; NORTH-ATLANTIC; CLIMATE-CHANGE; SATELLITE ALTIMETRY; THERMAL-EXPANSION; LATE HOLOCENE; RISE; PRESSURE; AMERICA AB Future sea level rise arouses concern because of potentially deleterious impacts to coastal regions. These will stem not only from the loss of land through inundation and erosion, but also from increased frequency of storm floods, with a rising base level, even with no change in storm climatology, and from saltwater intrusion and greater amounts of waterlogging. Current sea level trends are important in formulating an accurate baseline for future projections. Sea level, furthermore, is an important parameter which integrates a number of oceanic and atmospheric processes. The ocean surface demonstrates considerable variability on diurnal, seasonal, and interannual time scales, induced by winds, storm waves, coastal upwelling, and geostrophic currents. Secular trends in sea level arise from changes in global mean temperature and also from crustal deformation on local to regional scales. The challenge facing researchers is how best to extract the climate signal from this noise. This paper re-examines recent estimates of sea level rise, discusses causes of variability in the sea level records, and describes methods employed to filter out some of these contaminating signals. Evidence for trends in long-term sea level records and in extreme events is investigated. Application of satellite geodesy to sea level research is briefly reviewed. C1 NASA, GODDARD SPACE FLIGHT CTR, INST SPACE STUDIES, NEW YORK, NY 10025 USA. RP COLUMBIA UNIV, CTR CLIMATE SYST RES, 2880 BROADWAY, NEW YORK, NY 10025 USA. NR 130 TC 30 Z9 32 U1 1 U2 18 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0165-0009 EI 1573-1480 J9 CLIMATIC CHANGE JI Clim. Change PD DEC PY 1995 VL 31 IS 2-4 BP 515 EP 544 DI 10.1007/BF01095160 PG 30 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA TP565 UT WOS:A1995TP56500021 ER PT J AU Karaoglan, L Noor, AK AF Karaoglan, L Noor, AK TI Dynamic sensitivity analysis of frictional contact impact response of axisymmetric composite structures SO COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING LA English DT Article ID ELEMENT; CONSTRAINTS; FORMULATION AB A computational procedure is presented for evaluating the sensitivity coefficients of the dynamic frictional contact/impact response of axisymmetric composite structures. The structures are assumed to consist of an arbitrary number of perfectly bonded homogeneous anisotropic layers. The material of each layer is assumed to be hyperelastic, and the effect of geometric non-linearity is included. The sensitivity coefficients measure the sensitivity of the response to variations in different material, lamination and geometric parameters of the structure. A displacement finite element model is used for the discretization. The normal contact conditions are incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the nodal displacements, and the Lagrange multipliers associated with the contact conditions. The Lagrange multipliers are allowed to be discontinuous at interelement boundaries. Tangential contact conditions are incorporated by using a penalty method in conjunction with the classical Coulomb's friction model. Temporal integration is performed by using the Newmark method. The Newton-Raphson iterative scheme is used for the solution of the resulting non-linear algebraic equations, and for the determination of the contact region, contact conditions (sliding or sticking) and the contact pressures. The sensitivity coefficients are evaluated by using a direct differentiation approach. Numerical results are presented for the frictional contact/impact response of a composite spherical cap impacting on a rigid plate. RP Karaoglan, L (reprint author), UNIV VIRGINIA,NASA,LANGLEY RES CTR,CTR COMPUTAT STRUCT TECHNOL,HAMPTON,VA 23681, USA. NR 36 TC 7 Z9 7 U1 2 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0045-7825 J9 COMPUT METHOD APPL M JI Comput. Meth. Appl. Mech. Eng. PD DEC 1 PY 1995 VL 128 IS 1-2 BP 169 EP 190 DI 10.1016/0045-7825(95)00853-X PG 22 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications; Mechanics SC Engineering; Mathematics; Mechanics GA TK504 UT WOS:A1995TK50400009 ER PT J AU MEYER, T SURESH, R ILG, D MOXON, B AF MEYER, T SURESH, R ILG, D MOXON, B TI MOSAIC, HDF AND EOSDIS - PROVIDING ACCESS TO EARTH-SCIENCES DATA SO COMPUTER NETWORKS AND ISDN SYSTEMS LA English DT Article; Proceedings Paper CT 2nd International World-Wide Web Conference - Mosaic and the Web CY OCT 17-20, 1994 CL CHICAGO, IL DE EARTH SCIENCE DATA; INTERNET; WWW; EOS; NASA AB The National Aeronautics and Space Administration is developing the Earth Observing System Data and Information System (EOSDIS) to receive, process, and distribute Earth and environmental science data from the EOS series of sensors to be launched beginning in 1997 as a part of the Mission to Planet Earth program. This paper describes how Mosaic, HDF, and NCSA's Collage can support access and sharing of Earth science data by users of this system. Additionally, the paper presents the relationship of WWW and EOSDIS development. ''The U.S. Global Change Research Program requires massive quantities of highly diverse data and information to improve our understanding of global change processes.'' C1 HUGHES STX,GREENBELT,MD 20720. NASA,GODDARD SPACE FLIGHT CTR,EARTH SCI DATA & INFORMAT SYST PROJECT,GREENBELT,MD 20771. HUGHES APPL INFORMAT SYST,LANDOVER,MD 20785. NR 0 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7552 J9 COMPUT NETWORKS ISDN JI Comput. Netw. ISDN Syst. PD DEC PY 1995 VL 28 IS 1-2 BP 221 EP 229 DI 10.1016/0169-7552(95)00108-5 PG 9 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA TK326 UT WOS:A1995TK32600024 ER PT J AU Pruett, CD Zang, TA AF Pruett, CD Zang, TA TI On simulation and analysis of instability and transition in high-speed boundary-layer flows SO COMPUTING SYSTEMS IN ENGINEERING LA English DT Article AB The simulation of instabilities and laminar-trubulent transition in high-speed boundary-layer flows represents one of the major computational challenges of the decade. By taking advantage of recent advances in computational science and instability theory for compressible flows, we have formulated an approach to this problem that combines parabolized stability equation (PSE) methodology with spatial direct numerical simulation (DNS). The relatively inexpensive PSE method is used to explore the parameter space, to compute the early (weakly and moderately nonlinear) stages of laminar breakdown, and to provide inflow conditions for the spatial DNS, which is then used to compute the highly nonlinear laminar-breakdown stage. The approach is made feasible by an accurate and efficient DNS algorithm, which has been implemented in parallel on a GRAY C90 supercomputer. The design of the DNS algorithm is discussed in detail, with emphasis on factors that affect both accuracy and efficiency. The method is applied to the investigation of the laminar breakdown of the boundary layer on an axisymmetric sharp cone in Mach 8 flow. Techniques for analysis of the resulting data are also addressed, including novel computational flow imaging procedures. C1 NASA,LANGLEY RES CTR,MULTIDISCIPLINARY DESIGN OPTIMIZAT BRANCH,HAMPTON,VA 23681. RP Pruett, CD (reprint author), COLL WILLIAM & MARY,PROGRAM APPL SCI,WILLIAMSBURG,VA 23187, USA. NR 32 TC 5 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-0521 J9 COMPUT SYST ENG JI Comput. Syst. Eng. PD DEC PY 1995 VL 6 IS 6 BP 563 EP 575 PG 13 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary SC Computer Science; Engineering GA TZ004 UT WOS:A1995TZ00400007 ER PT J AU Hadian, J Mirvis, Y NourOmid, B Murthy, P Nakazawa, S AF Hadian, J Mirvis, Y NourOmid, B Murthy, P Nakazawa, S TI Prediction of high temperature metal matrix structural material failure using a massively parallel computer SO COMPUTING SYSTEMS IN ENGINEERING LA English DT Article AB Large scale high speed design and analysis of next generation aerospace systems is achieved by focusing on the computational integration and synchronization of probabilistic mathematics, structural/material mechanics, and parallel computing. Design costs have been driven upward by mathematical models that require multiple levels of interactive analysis and utilize time consuming convergence criteria that further drive computing and design costs upward. To reduce CPU time and memory limitations, an effective real time parallelization (RTP) of the solution is introduced. Recursive internal Partitioning (RIP) is used to partition the entire domain into subdomains with one or more subdomains being assigned to each independent processor. The Alpha STAR multifrontal algorithm (AMF) is implemented to assemble, condense, and solve for the unknowns at all finite element nodes. A multi level optimization technique is utilized to speed up the simulation processing time of the diversified field of specialized analysis techniques and mathematical models. These models require hierarchical multiple levels of interactive analysis utilizing time consuming convergence. The generic high speed civil transport (hsct) model is used to demonstrate the large scale computing capability. Results of multicriteria optimization indicate an order of magnitude reduction in computing time. Numerical solutions as well as physical phenomena are discussed and recommendations are provided for future solutions. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. FINITE ELEMENT FACTORY,SUNNYVALE,CA. RP Hadian, J (reprint author), ALPHA STAR CORP,LOS ANGELES,CA, USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-0521 J9 COMPUT SYST ENG JI Comput. Syst. Eng. PD DEC PY 1995 VL 6 IS 6 BP 577 EP 586 DI 10.1016/0956-0521(95)00020-8 PG 10 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary SC Computer Science; Engineering GA TZ004 UT WOS:A1995TZ00400008 ER PT J AU Breininger, DR Larson, VL Duncan, BW Smith, RB Oddy, DM Goodchild, MF AF Breininger, DR Larson, VL Duncan, BW Smith, RB Oddy, DM Goodchild, MF TI Landscape patterns of Florida Scrub Jay habitat use and demographic success SO CONSERVATION BIOLOGY LA English DT Article ID POPULATION-DYNAMICS; COMPLEX LANDSCAPES; TERRITORY SIZE; COMMUNITY; BIRDS; SINKS; FIRE AB Remote sensing and geographical information systems are used to analyze landscapes important to species of conservation concern. The accuracy of the methods depends on how closely habitat mapping classes are linked to population demography Habitat use by Florida Scrub Jays (Aphelocoma c. coerulescens) was quantified using circular plots. Habitat variation was mapped using high-resolution aerial photography on a site where all Florida Scrub Jays were color-banded. Nest site selection, nest success, yearling production, and breeder survival were measured within Florida Scrub Jay territories. Habitat use was lowest in areas without scrub oaks or areas within 136 m from forests. Open oak, dominated by scrub oaks and open sandy areas, had the highest use and nest success among habitats. Open oak occurred as narrow patches (<20 m wine) in landscapes dominated by matrix habitat (palmetto-lyonia and swale marshes). Most wide patches (>50 m) of open oak were potential population sources, where reproduction exceeded mortality. Areas with patches of open oak of less than 1 ha were usually population sinks. Open oak occurred as less flammable patches in a landscape subject to frequent fires. Population sources varied temporally and spatially with fires and sire potential to support scrub oaks (soils). Analyses of landscape patterns and dynamics indicated that habitat mapping should not only include patches of currently optimal habitat but should also include landscapes associated with open oak. The influences of landscape patterns on habitat use, reproductive success, survival, and territory size can be quantified at different scales starting with attributes associated with habitat patches, nest sites, and territories. Potential mapping errors occur, however, when habitats are used to quantify the areal extent of sources and sinks and similar population attributes important for species persistence. C1 UNIV CALIF SANTA BARBARA, NATL CTR GEOG INFORMAT & ANAL, SANTA BARBARA, CA 93106 USA. RP Breininger, DR (reprint author), NASA, BIOMED OPERAT & RES OFF, DYNAMAC CORP, DYN-2, KENNEDY SPACE CTR, FL 32899 USA. NR 48 TC 38 Z9 39 U1 2 U2 14 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0888-8892 EI 1523-1739 J9 CONSERV BIOL JI Conserv. Biol. PD DEC PY 1995 VL 9 IS 6 BP 1442 EP 1453 DI 10.1046/j.1523-1739.1995.09061442.x PG 12 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA TL672 UT WOS:A1995TL67200013 ER PT J AU Wang, LP AF Wang, LP TI Dynamic effect of open latitude on wind-driven circulation in a zonal beta-plane channel SO DYNAMICS OF ATMOSPHERES AND OCEANS LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; QUASI-GEOSTROPHIC MODEL; IDEALIZED MODEL; TOPOGRAPHY; OCEAN; FLOW AB We confirmed the hypothesis originally proposed by Stommel (Deep-Sea Res., 4: 149-184, 1957) that to have a finite through-channel transport in a circumpolar ocean, open latitude is not necessary. In a homogeneous model, inclusion of open latitude does not fundamentally affect the circulation structure and composition of the through-channel transport, though the transport dependence on the model parameters is affected. However, in a stratified model, open latitude has a fundamental impact on both the composition of the through-channel transport and the baroclinic structure of the wind-driven circulation. RP Wang, LP (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CODE 971, GREENBELT, MD 20771 USA. NR 31 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0265 J9 DYNAM ATMOS OCEANS JI Dyn. Atmos. Oceans PD DEC PY 1995 VL 22 IS 4 BP 179 EP 198 DI 10.1016/0377-0265(95)00461-0 PG 20 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA TM675 UT WOS:A1995TM67500001 ER PT J AU LERDAU, M MATSON, P FALL, R MONSON, R AF LERDAU, M MATSON, P FALL, R MONSON, R TI ECOLOGICAL CONTROLS OVER MONOTERPENE EMISSIONS FROM DOUGLAS-FIR (PSEUDOTSUGA-MENZIESII) SO ECOLOGY LA English DT Article DE ATMOSPHERIC CHEMISTRY; CARBON-NUTRIENT BALANCE HYPOTHESIS; CHEMICAL DEFENSE; DOUGLAS-FIR; GROWTH-DIFFERENTIATION BALANCE HYPOTHESIS; MONOTERPENE CONCENTRATION; MONOTERPENE EMISSION; NITROGEN AVAILABILITY; PHENOLOGY; PSEUDOTSUGA MENZIESII ID CARBON NUTRIENT BALANCE; NITROGEN-FERTILIZATION; HETEROTHECA-SUBAXILLARIS; ISOPRENE EMISSION; RATE VARIABILITY; UNITED-STATES; PINE; FOREST; MODEL; ECOSYSTEMS AB The roles of nitrogen availability and seasonality in controlling monoterpene concentration in and emission from Douglas-fir (Pseudotsuga menziesii) were examined in a greenhouse study. Plants were maintained at three nitrogen levels, and foliar nitrogen concentration, photosynthetic rate, monoterpene concentration, and monoterpene emission rate were measured over an entire phenological cycle, from before bud break in the spring through winter dormancy. Both nitrogen fertilization level and phenological stage affected the concentration of monoterpenes in the foliage. There was also a consistent linear relationship between monoterpene concentration and monoterpene emission. Out of the nitrogen-phenology-concentration and the concentration-emission relationships comes a predictable relationship between nitrogen, phenology and monoterpene emission, This relationship allows linkage between atmospheric chemical processes, such as ozone production, and ecological ones, such as leaf expansion. The results also demonstrate that theories on allocation to defense need to consider the phenological stage of the plant as well as the availability of resources. C1 STANFORD UNIV,STANFORD,CA 94305. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. UNIV COLORADO,BOULDER,CO 80309. RI Lerdau, Manuel/E-7320-2011 OI Lerdau, Manuel/0000-0003-1864-0834 NR 50 TC 83 Z9 89 U1 4 U2 20 PU ECOLOGICAL SOC AMER PI TEMPE PA ARIZONA STATE UNIV CENTER ENVIRONMENTAL STUDIES, TEMPE, AZ 85287 SN 0012-9658 J9 ECOLOGY JI Ecology PD DEC PY 1995 VL 76 IS 8 BP 2640 EP 2647 DI 10.2307/2265834 PG 8 WC Ecology SC Environmental Sciences & Ecology GA TJ312 UT WOS:A1995TJ31200023 ER PT J AU Davis, MW Olla, BL AF Davis, MW Olla, BL TI Formation and maintenance of aggregations in walleye pollock, Theragra chalcogramma, larvae under laboratory conditions: Role of visual and chemical stimuli SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE behavior; chemosensory; distribution; fish larvae; orientation; olfaction; patches; vision ID CLUPEA-HARENGUS; FEEDING-BEHAVIOR; HERRING LARVAE; PLANKTON; GROWTH; LIGHT; PATCH; FOOD; PREY; FISH AB Although planktonic marine fish larvae are often distributed in aggregations, the role of behavioral responses to environmental factors in these aggregations is not well understood. This work examines, under laboratory conditions, the influence of visual and chemical stimuli in the formation and maintenance of aggregations in walleye pollock, Theragra chalcogramma, larvae. Larvae were exposed to a horizontal gradient of light (visual stimulus), prey scent (chemical stimuli: squid/copepod and rotifer) or prey density (visual & chemical stimuli: rotifers). While larvae did not respond to prey scent, they did respond to a gradient of light or prey, which resulted in the formation and maintenance of aggregations. Larvae moved into and remained in a zone of higher light intensity (0.56 versus 0.01 mu mol photons m(-2) s(-1)). Once encountering a patch of prey, larvae remained aggregated within the patch to feed. In nature, movement of walleye pollock larvae in response to selected environmental factors (e.g., gravity, light, temperature, turbulence) may serendipitously bring them into contact with prey patches, where they then could remain to feed as long as light intensity remained at or above levels necessary for feeding. RP Davis, MW (reprint author), OREGON STATE UNIV,HATFIELD MARINE SCI CTR,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NEWPORT,OR 97365, USA. NR 39 TC 13 Z9 13 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD DEC PY 1995 VL 44 IS 4 BP 385 EP 392 DI 10.1007/BF00008253 PG 8 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA TQ925 UT WOS:A1995TQ92500010 ER PT J AU ROZAS, LP AF ROZAS, LP TI HYDROPERIOD AND ITS INFLUENCE ON NEKTON USE OF THE SALT-MARSH - A PULSING ECOSYSTEM SO ESTUARIES LA English DT Article; Proceedings Paper CT Symposium on Pulsed Ecosystems - A New Paradigm/Estuarine-Research-Federation Meeting CY NOV, 1993 CL HILTON HEAD ISL, SC SP Estuarine Res Federat ID CORDGRASS SPARTINA-ALTERNIFLORA; FUNDULUS-HETEROCLITUS; PENAEUS-AZTECUS; SEA-LEVEL; POPULATION-DYNAMICS; RIBBED MUSSELS; BRACKISH MARSH; NORTH-CAROLINA; BROWN SHRIMP; TIDAL MARSH AB The salt marsh surface is not a homogeneous environment. Rather, it contains a mix of different micro-habitats, which vary in elevation, microtopography, and location within the estuarine system. These attributes act in concert with astronomical tides and meteorological and climatological events and result in pulses of tidal flooding. Marsh hydroperiod, the pattern of flooding events, not only controls nekton access to marsh surface habitats directly but may also mediate habitat exploitation through its influence on other factors, such as prey abundance or vegetation stem density. The relative importance of factors affecting marsh hydroperiod differ between the southeast Atlantic and northern Gulf of Mexico coasts. Astronomical tidal forcing is the primary determinant of hydroperiod in Atlantic Coast marshes, whereas predictable tides are often overridden by meteorological events in Gulf Coast marshes. In addition, other factors influencing coastal water levels have a proportionately greater effect on the Gulf Coast. The relatively unpredictable timing of marsh flooding along the Gulf Coast does not seem to limit habitat utilization. Some of the highest densities of nekton reported from salt marshes are from Gulf Coast marshes that are undergoing gradual submergence and fragmentation caused by an accelerated rise in relative sea level. Additional studies of habitat utilization are needed, especially on the Pacific and Atlantic coasts. Investigations should include regional comparisons of similar microhabitats using identical quantitative sampling methods. Controlled field experiments are also needed to elucidate the mechanisms that affect the habitat function of salt marshes. RP ROZAS, LP (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,4700 AVE U,GALVESTON,TX 77551, USA. NR 104 TC 97 Z9 99 U1 1 U2 11 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD DEC PY 1995 VL 18 IS 4 BP 579 EP 590 DI 10.2307/1352378 PG 12 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA TA813 UT WOS:A1995TA81300005 ER PT J AU CHANDRASEKHARA, MS SQUIRES, DD WILDER, MC CARR, LW AF CHANDRASEKHARA, MS SQUIRES, DD WILDER, MC CARR, LW TI A PHASE-LOCKED HIGH-SPEED REAL-TIME INTERFEROMETRY SYSTEM FOR LARGE-AMPLITUDE UNSTEADY FLOWS SO EXPERIMENTS IN FLUIDS LA English DT Article AB A high-speed phase-locked interferometry system has been designed and developed for real-time measurements of dynamic stall flow over a pitching airfoil. Point diffraction interferograms of incipient flow separation over a sinusoidally oscillating airfoil have been obtained at framing rates of up to 20 kHz and for free stream Mach numbers of 0.3 and 0.45. The images were recorded on 35 mm ASA 125 and ASA 400 films using a drum camera. Special electronic timing and synchronizing circuits were developed to trigger the laser light source from the camera and to initiate acquisition of the interferogram sequence from any desired phase angle of oscillation. The airfoil instantaneous angle of attack data provided by an optical encoder was recorded via a FIFO data buffer into a microcomputer. The interferograms have been analyzed using software developed in-house to get quantitative flow density and pressure distributions. C1 USN,NASA,POSTGRAD SCH,JOINT INST AERONAUT,DEPT AERONAUT & ASTRONAUT,MONTEREY,CA 93943. SVERDRUP TECHNOL INC,MOFFETT FIELD,CA 94035. USN,NASA,INST MCAT,SAN JOSE,CA 95127. USA ATCOM,UNSTEADY VISCOUS FLOWS AEROFLIGHTDYNAM DIRECTORAT,MOFFETT FIELD,CA 94035. NASA,AMES RES CTR,FLUID DYNAM RES BRANCH,MOFFETT FIELD,CA 94035. NR 6 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0723-4864 J9 EXP FLUIDS JI Exp. Fluids PD DEC PY 1995 VL 20 IS 2 BP 61 EP 67 DI 10.1007/BF01061583 PG 7 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA TJ764 UT WOS:A1995TJ76400001 ER PT J AU CARLOTTI, M ADE, PAR CARLI, B CIARPALLINI, P CORTESI, U GRIFFIN, MJ LEPRI, G MENCARAGLIA, F MURRAY, AG NOLT, IG PARK, JH RADOSTITZ, JV AF CARLOTTI, M ADE, PAR CARLI, B CIARPALLINI, P CORTESI, U GRIFFIN, MJ LEPRI, G MENCARAGLIA, F MURRAY, AG NOLT, IG PARK, JH RADOSTITZ, JV TI MEASUREMENT OF STRATOSPHERIC HBR USING HIGH-RESOLUTION FAR-INFRARED SPECTROSCOPY SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SUBMILLIMETER AB Far infrared spectral features of HBr have been observed in the stratospheric emission spectrum using a balloon borne high resolution Fourier transform spectrometer equipped with a high sensitivity detector specially designed for this purpose, The value of 1.6 +/- 0.6 parts per trillion in volume for the HBr mixing ratio has been retrieved, from the global-fit analysis of 121 spectra, in the 25 - 36.5 km altitude range. The result is briefly compared with models and previous assessinents. C1 QUEEN MARY & WESTFIELD COLL,LONDON,ENGLAND. CNR NELLO CARRARO,IST RIC ONDE ELETTROMAGNET,FLORENCE,ITALY. UNIV FLORENCE,DIPARTIMENTO ASTRON & SCI SPAZIO,I-50144 FLORENCE,ITALY. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP CARLOTTI, M (reprint author), UNIV BOLOGNA,DIPARTIMENTO CHIM FIS & INORGAN,VIALE RISORGIMENTO 4,I-40136 BOLOGNA,ITALY. NR 14 TC 20 Z9 20 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3207 EP 3210 DI 10.1029/95GL03264 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100026 ER PT J AU HERMAN, JR NEWMAN, PA LARKO, D AF HERMAN, JR NEWMAN, PA LARKO, D TI METEOR-3/TOMS OBSERVATIONS OF THE 1994 OZONE HOLE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTIC OZONE; TOMS OBSERVATIONS; DEPLETION AB The development of the 1994 springtime (September - November) Antarctic ozone hole was observed by the Meteor-3/TOMS (Total Ozone Mapping Spectrometer) to result in a very low minimum ozone value, 90+/-5 DU (Dobson Units) on September 28, 1994. During late September and early October, the region of extremely low ozone values was centered on the geographical pole between 85 degrees S and 90 degrees S. The geographical extent of the ozone hole region, the area within the 220 DU contour, reached a maximum during the first week in October with an elliptical area covering 24 x 10(6) km(2), reaching to the southern tip of South America. This approximately matched previous area records. After the maximum area was reached in early October, the 1994 ozone hole region was very similar to. the 1993 ozone hole throughout the remainder of the month. The area of low temperatures (<196 K), where polar stratospheric clouds (PSCs) can form and heterogeneous chemistry is significant, has not increased over the past 16 years. During this period, the large trends in-the area and minimum ozone amounts of the Antarctic ozone hole do not appear to be related to atmospheric temperature trends. C1 HUGHES STX CORP,GREENBELT,MD 20771. RP HERMAN, JR (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,CODE 916,GREENBELT,MD 20771, USA. RI Newman, Paul/D-6208-2012; OI Newman, Paul/0000-0003-1139-2508; Herman, Jay/0000-0002-9146-1632 NR 20 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3227 EP 3229 DI 10.1029/95GL02850 PG 3 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100031 ER PT J AU POTTER, AE AF POTTER, AE TI CHEMICAL SPUTTERING COULD PRODUCE SODIUM VAPOR AND ICE ON MERCURY SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LUNAR ATMOSPHERE; DIFFUSION; POTASSIUM; SURFACE; MOON AB It is suggested that chemical sputtering of surface rocks by protons from the Mercury magnetosphere can yield sodium vapor more efficiently than physical sputtering, thus lowering the required sodium concentration in surface rocks. Chemical sputtering can also yield sodium vapor having a relatively low kinetic temperature, in agreement with observation. Water vapor is produced in addition to sodium vapor. It could be produced in sufficient amounts to explain the observation of ice in Mercury polar craters. RP POTTER, AE (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,SN3,HOUSTON,TX 77058, USA. NR 29 TC 55 Z9 56 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3289 EP 3292 DI 10.1029/95GL03181 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100047 ER PT J AU JOHNSON, TV MATSON, DL BLANEY, DL VEEDER, GJ DAVIES, A AF JOHNSON, TV MATSON, DL BLANEY, DL VEEDER, GJ DAVIES, A TI STEALTH PLUMES ON IO SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VOYAGER-1; VOLCANISM; SYSTEM; SO2 AB We suggest that Io's eruptive activity may include a class of previously undetected SO2 geysers. The thermodynamic models for the eruptive plumes discovered by Voyager involve low to moderate entropy SO2 eruptions. The resulting plumes are a mixture of solid and gas which emerge from the vent and follow essentially ballistic trajectories. We show that intrusion; of silicate magma into buried SO2 deposits can create the required conditions for high entropy eruptions which proceed entirely in the vapor phase. These purely gaseous plumes would have been invisible to Voyager's instruments. Hence, we call them ''stealth'' plumes. Such eruptions could explain the ''patchy'' SO2 atmosphere inferred from recent UV and microwave spectral observations. The magma intrusion rate required to support the required gas production for these plumes is a negligible fraction of estimated global magma intrusion rates. RP JOHNSON, TV (reprint author), CALTECH,JET PROP LAB,MS 183-501,PASADENA,CA 91109, USA. NR 30 TC 40 Z9 40 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3293 EP 3296 DI 10.1029/95GL03084 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100048 ER PT J AU SMITH, EJ MARSDEN, RG AF SMITH, EJ MARSDEN, RG TI ULYSSES OBSERVATIONS FROM POLE-TO-POLE - AN INTRODUCTION SO GEOPHYSICAL RESEARCH LETTERS LA English DT Editorial Material AB Recent results from the Ulysses spacecraft as it observed particles and fields above the Sun's south polar cap, returned rapidly across the equator and traversed the northern solar hemisphere are presented in subsequent articles. This introduction provides a brief description of the spacecraft, the experiments, the unique trajectory and highlights of some of the principal scientific results. C1 EUROPEAN SPACE AGCY,DEPT SPACE SCI,2200 AG NOORDWIJK,NETHERLANDS. RP SMITH, EJ (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 25 TC 29 Z9 30 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3297 EP 3300 DI 10.1029/95GL03556 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100049 ER PT J AU PHILLIPS, JL BAME, SJ BARNES, A BARRACLOUGH, BL FELDMAN, WC GOLDSTEIN, BE GOSLING, JT HOOGEVEEN, GW MCCOMAS, DJ NEUGEBAUER, M SUESS, ST AF PHILLIPS, JL BAME, SJ BARNES, A BARRACLOUGH, BL FELDMAN, WC GOLDSTEIN, BE GOSLING, JT HOOGEVEEN, GW MCCOMAS, DJ NEUGEBAUER, M SUESS, ST TI ULYSSES SOLAR-WIND PLASMA OBSERVATIONS FROM POLE TO POLE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INFERENCES AB We present Ulysses solar wind plasma data from the peak southerly latitude of -80.2 degrees on 12 September 1994 through the corresponding northerly latitude on 31 July 1995. Ulysses encountered fast wind throughout this time except far a 43 degrees band centered on the solar equator. Median mass flux was nearly constant with latitude, while speed and density had positive and negative poleward gradients, respectively. Solar wind momentum flux was highest at high latitudes, suggesting a latitudinal asymmetry in the heliopause cross section. Solar wind energy flux density was also highest at high latitudes. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. CALTECH,JET PROP LAB,PASADENA,CA 91109. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP PHILLIPS, JL (reprint author), LOS ALAMOS NATL LAB,MAIL STOP D466,LOS ALAMOS,NM 87545, USA. NR 17 TC 266 Z9 269 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3301 EP 3304 DI 10.1029/95GL03094 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100050 ER PT J AU PHILLIPS, JL GOLDSTEIN, BE GOSLING, JT HAMMOND, CM HOEKSEMA, JT MCCOMAS, DJ AF PHILLIPS, JL GOLDSTEIN, BE GOSLING, JT HAMMOND, CM HOEKSEMA, JT MCCOMAS, DJ TI SOURCES OF SHOCKS AND COMPRESSIONS IN THE HIGH-LATITUDE SOLAR-WIND - ULYSSES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EVOLUTION AB During its southern transit Ulysses sampled the solar wind to -80.2 degrees latitude. Slow streamer belt wind was seen only equatorward of -35 degrees, but its influence extended to much higher latitudes. Reverse shocks bounding the equatorial CIR were seen as far south as -58.2 degrees. High-latitude compressional waves showed no clear correlation with that CIR. Speed and density patterns show that solar rotational modulation persisted up to 25 degrees poleward of the slow wind. Compressional structures at highest latitudes were probably driven by spatial or temporal variations within the southern coronal hole. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. SRI INT,APPL ELECTROMAGNET & OPT LAB,MENLO PK,CA 94025. STANFORD UNIV,STANFORD,CA 94305. RP PHILLIPS, JL (reprint author), LOS ALAMOS NATL LAB,MAIL STOP D466,LOS ALAMOS,NM 87545, USA. NR 14 TC 18 Z9 19 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3305 EP 3308 DI 10.1029/95GL02228 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100051 ER PT J AU BARNES, A GAZIS, PR PHILLIPS, JL AF BARNES, A GAZIS, PR PHILLIPS, JL TI CONSTRAINTS ON SOLAR-WIND ACCELERATION MECHANISMS FROM ULYSSES PLASMA OBSERVATIONS - THE FIRST POLAR PASS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HELIOGRAPHIC LATITUDES; CORONAL HOLE; PIONEER AB The mass flux density and velocity of the solar wind at polar latitudes can provide strong constraints on solar wind acceleration mechanisms. We use plasma observations from the first polar passage of the Ulysses spacecraft to investigate this question. We find that the mass flux density and velocity are too high to reconcile with acceleration of the solar wind by classical thermal conduction alone. Therefore acceleration of the high-speed wind must involve extended deposition of energy by some other mechanism, either as heat or as a direct effective pressure, due possibly to waves and/or turbulence, or completely non-classical heat transport. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. NASA, AMES RES CTR, SJSU FDN, MOFFETT FIELD, CA 94035 USA. RP BARNES, A (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MOFFETT FIELD, CA 94035 USA. NR 18 TC 23 Z9 26 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 DEC 1 PY 1995 VL 22 IS 23 BP 3309 EP 3311 DI 10.1029/95GL03532 PG 3 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100052 ER PT J AU PATZOLD, M BIRD, MK EDENHOFER, P ASMAR, SW MCELRATH, TP AF PATZOLD, M BIRD, MK EDENHOFER, P ASMAR, SW MCELRATH, TP TI DUAL-FREQUENCY RADIO SOUNDING OF THE SOLAR CORONA DURING THE 1995 CONJUNCTION OF THE ULYSSES SPACECRAFT SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CYCLE; WIND AB The Ulysses Solar Corona Experiment was performed during the spacecraft's superior solar conjunction from 22 February to 14 March 1995, shortly before perihelion and the transit through the ecliptic plane. The high inclination of the Ulysses orbit resulted in an unusual occultation geometry for coronal radio sounding with the spacecraft's dual-frequency downlink signals. Viewed from Earth, the virtual position of Ulysses on the plane of the sky moved diagonally through the southwest quadrant of the corona from the solar South Pole to the heliographic equator. The ima pact parameter of the ray path (solar offset) varied from 32 solar radii (R. at the beginning and end of the experiment down to a minimum of 21.4 R. at 45 degrees S. The total electron content of the inner heliosphere, computed from measurements of the dual-frequency ranging propagation delays, is presented as a function of latitude and solar offset. The observations are compared with the coronal structure inferred from synoptic magnetic source surface maps. An increase in electron content by a factor of two is recorded from the center of the southern coronal hole at the pole to the equator the northernmost extension of the hole at the time oi the observation. A streamer belt, identified by an abrupt rise in electron content, rotated into the radio ray path at southern heliographic latitudes between 16 degrees and 21 degrees. C1 UNIV BONN,INST RADIOASTRON,D-53121 BONN,GERMANY. RUHR UNIV BOCHUM,INST HOCHFREQUENZTECH,D-44780 BOCHUM,GERMANY. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP PATZOLD, M (reprint author), UNIV COLOGNE,INST GEOPHYS & METEOROL,ALBERTUS MAGNUS PL,D-50923 COLOGNE,GERMANY. NR 14 TC 15 Z9 16 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3313 EP 3316 DI 10.1029/95GL03184 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100053 ER PT J AU SMITH, EJ BALOGH, A AF SMITH, EJ BALOGH, A TI ULYSSES OBSERVATIONS OF THE RADIAL MAGNETIC-FIELD SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRENGTH AB The radial component of the magnetic field in the southern hemisphere has been measured at Ulysses as it traveled from the equator to -80.2 degrees latitude and returned. The radial component multiplied by the square of the radial distance, i.e., B(R)r(2), averaged over 77 day intervals (three solar rotations) is approximately constant at -3.5 nT and shows no evidence of a dependence on heliographic latitude. To discriminate against possible time variations, the measurements have been compared with simultaneous observations in the ecliptic by IMP-8. The two sets of observations agree very well confirming the absence of a significant latitude gradient. Since the sun's dipolar magnetic field component is strong at this phase of the sunspot cycle, it is inferred that magnetic flux from the polar cap is transported to lower latitudes in the solar wind source region to produce a uniform radial field. Such a configuration would be expected if magnetic stresses are influencing the solar wind flow near the sun and are contributing to a non-radial deflection. Estimates of the flux of open field lines (3x10(14) webers), of the nonradial solar wind expansion (similar to 3) and the polar cap magnetic field strength (similar to 5 Gauss) are derived. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND. RP SMITH, EJ (reprint author), CALTECH, JET PROP LAB, M-S 169-506, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 16 TC 118 Z9 120 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 DEC 1 PY 1995 VL 22 IS 23 BP 3317 EP 3320 DI 10.1029/95GL02826 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100054 ER PT J AU FORSYTH, RJ BALOGH, A SMITH, EJ MURPHY, N MCCOMAS, DJ AF FORSYTH, RJ BALOGH, A SMITH, EJ MURPHY, N MCCOMAS, DJ TI THE UNDERLYING MAGNETIC-FIELD DIRECTION IN ULYSSES OBSERVATIONS OF THE SOUTHERN POLAR HELIOSPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Between April and November 1994 the Ulysses spacecraft explored heliographic latitudes above 60 degrees S in the southern polar heliosphere and had returned to 20 degrees S by February 1995. We have used hourly averages of the magnetic field measurements made by Ulysses to study the underlying heliospheric field direction. In contrast to data previously reported from lower latitudes, we find that above 60 degrees S neither the mean nor the most probable azimuthal angle of the magnetic field agree with that predicted by the Parker model, the most probable angle being of the order of 24 degrees more tightly wound than expected. The distribution of azimuth angles retains the high degree of asymmetry previously found at lower latitudes causing the mean angle to remain slightly less tightly wound than the prediction. In this high latitude region, the distribution of the meridional (north-south) angle is found to be symmetric with mean and most probable values close to the Parker prediction. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP FORSYTH, RJ (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,PRINCE CONSORT RD,LONDON SW7 2BZ,ENGLAND. NR 11 TC 37 Z9 38 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3321 EP 3324 DI 10.1029/95GL02646 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100055 ER PT J AU SMITH, EJ BALOGH, A BURTON, ME ERDOS, G FORSYTH, RJ AF SMITH, EJ BALOGH, A BURTON, ME ERDOS, G FORSYTH, RJ TI RESULTS OF THE ULYSSES FAST LATITUDE SCAN - MAGNETIC-FIELD OBSERVATIONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SECTOR AB The rapid crossing of the solar equatorial region by Ulysses as it returned from the south pole resulted in 7 crossings of the heliospheric current sheet between 10 degrees S and 20 degrees N and 10 distinct solar wind interaction regions between 18 degrees S and 22 degrees N. Both the extent of the current sheet and the latitude interval containing the interaction regions are a factor of approximate to 2 less than were observed by Ulysses when it left the equatorial region in 1993. A map of the current sheet in heliographic latitude and Carrington longitude reveals two folds corresponding to 4 magnetic sectors. The coronal holes associated with the sectors, the interaction regions and highspeed streams have been identified. Two sectors were associated with a pair of asymmetrically-placed polar coronal holes whereas the other two sectors coincided with a pair of near-equatorial coronal holes on opposite sides of the equator. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. HUNGARIAN ACAD SCI,KFKI,INST NUCL & PARTICLE PHYS,H-1525 BUDAPEST,HUNGARY. NR 8 TC 47 Z9 47 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3325 EP 3328 DI 10.1029/95GL03088 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100056 ER PT J AU GOSLING, JT BAME, SJ FELDMAN, WC MCCOMAS, DJ PHILLIPS, JL GOLDSTEIN, B NEUGEBAUER, M BURKEPILE, J HUNDHAUSEN, AJ ACTON, L AF GOSLING, JT BAME, SJ FELDMAN, WC MCCOMAS, DJ PHILLIPS, JL GOLDSTEIN, B NEUGEBAUER, M BURKEPILE, J HUNDHAUSEN, AJ ACTON, L TI THE BAND OF SOLAR-WIND VARIABILITY AT LOW HELIOGRAPHIC LATITUDES NEAR SOLAR-ACTIVITY MINIMUM - PLASMA RESULTS FROM THE ULYSSES RAPID LATITUDE SCAN SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Near solar activity minimum large variations in the quiescent solar wind now are confined to a narrow latitude band centered near the heliographic equator. During Ulysses' recent rapid latitude scan this band was similar to 43 degrees wide. Flow parameters poleward of the band in the opposite solar hemispheres were nearly the same. Main entry into the band of variable solar wind was via a shock disturbance most likely associated with over-expansion of a coronal mass ejection event. Wind variability within the band was associated primarily with longitudinal structure in the solar corona and solar rotation; high-speed streams observed there were associated with locations where the polar coronal holes extended equatorward toward the Ulysses orbit. Observations indicate that the polar coronal holes at this time occupied only similar to 13% of the low Corona, yet a nearly uniform high-speed wind (average speed similar to 750 km s(-1)) filled similar to 63% of the heliosphere. This indicates the holes expanded by a factor of similar to 4.8 from the low corona to interplanetary space. Much of this lateral expansion occurred beyond 1.74 solar radii from Sun center. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NATL CTR ATMOSPHER RES,HIGH ALTITUDE OBSERV,BOULDER,CO 80307. MONTANA STATE UNIV,BOZEMAN,MT 59717. RP GOSLING, JT (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. NR 13 TC 66 Z9 66 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3329 EP 3332 DI 10.1029/95GL02163 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100057 ER PT J AU SANDERSON, TR BOTHMER, V MARSDEN, RG TRATTNER, KJ WENZEL, KP BALOGH, A FORSYTH, RJ GOLDSTEIN, BE AF SANDERSON, TR BOTHMER, V MARSDEN, RG TRATTNER, KJ WENZEL, KP BALOGH, A FORSYTH, RJ GOLDSTEIN, BE TI THE ULYSSES SOUTH POLAR PASS - ENERGETIC ION OBSERVATIONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SECTOR STRUCTURE; SOLAR AB We present here a preliminary analysis of observations of energetic ions during the first polar pass of the Ulysses spacecraft, concentrating mainly on the region where the spacecraft was continually immersed in high speed flow from the polar coronal hole. During the ascent to high latitudes, a single recurrent peak was observed once per solar rotation. From 70 degrees S during ascent to 43 degrees S during descent no major peaks were observed. Thereafter, two peaks per solar rotation were observed. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND. CALTECH, JET PROP LAB, PASADENA, CA USA. RP SANDERSON, TR (reprint author), ESA, ESTEC, DEPT SPACE SCI, NOORDWIJK, NETHERLANDS. NR 14 TC 39 Z9 39 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3357 EP 3360 DI 10.1029/95GL03089 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100063 ER PT J AU BOTHMER, V MARSDEN, RG SANDERSON, TR TRATTNER, KJ WENZEL, KP BALOGH, A FORSYTH, RJ GOLDSTEIN, BE AF BOTHMER, V MARSDEN, RG SANDERSON, TR TRATTNER, KJ WENZEL, KP BALOGH, A FORSYTH, RJ GOLDSTEIN, BE TI THE ULYSSES SOUTH POLAR PASS - TRANSIENT FLUXES OF ENERGETIC IONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR AB Using Ulysses low energy telescope (LET) measurements of protons and alpha particles with energies of similar to 1-5 MeV/n, we present first observations of transient energetic particle events in the high latitude heliosphere. Three transient particle events with gradual onsets and time durations of several days have been identified in the LET data at heliographic latitudes as high as similar to 60 degrees S, at radial distances from the Sun between 3.3-3.6 AU. No transient increases were observed polewards of 60 degrees S. All three of the events were associated with passage of a coronal mass ejection (CME) over Ulysses, and two were associated with the newly identified type of forward/reverse shock pairs in the solar wind caused by over-expanding CMEs. The largest of the three transient events has also been observed at Earth's orbit, i.e. in the ecliptic. The observations show that energetic particles can be convected into the high latitude heliosphere through CMEs. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. CALTECH,JET PROP LAB,PASADENA,CA. RP BOTHMER, V (reprint author), EUROPEAN SPACE AGCY,ESTEC,DEPT SPACE SCI,POSTBUS 299,2200 AG NOORDWIJK,NETHERLANDS. NR 19 TC 26 Z9 26 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3369 EP 3372 DI 10.1029/95GL02620 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100066 ER PT J AU SMITH, EJ BALOGH, A NEUGEBAUER, M MCCOMAS, D AF SMITH, EJ BALOGH, A NEUGEBAUER, M MCCOMAS, D TI ULYSSES OBSERVATIONS OF ALFVEN WAVES IN THE SOUTHERN AND NORTHERN SOLAR HEMISPHERES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIAL EVOLUTION; WIND; ACCELERATION; FLUCTUATIONS; TURBULENCE AB Alfven waves with periods from < 1 to > 10 hours are shown to be continuously present in the sun's south and north polar regions. Below approximate to 30 degrees latitude, as revealed by the rapid traversal of the equatorial region by Ulysses, the wave power averaged over a solar rotation decreases abruptly. The correlations between magnetic field and solar wind velocity fluctuations, upon which the wave identification is based, indicate outward propagation in both hemispheres. The Ulysses observations are consistent with many of the properties of Alfven waves seen in the ecliptic in association with high speed streams. Some implications of the waves in the polar regions are explored. Because of the long wavelengths, which reach approximate to 0.3AU, the waves resonate with 10-10(3)MeV/nucIeon galactic cosmic rays and oppose their entry into the polar caps. The wave amplitudes imply a contribution to the acceleration of the high latitude wind due to momentum transfer of only a few percent. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. CALTECH,JET PROP LAB,PASADENA,CA 91109. LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,LOS ALAMOS,NM 87545. RP SMITH, EJ (reprint author), CALTECH,JET PROP LAB,M-S 169-506,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 24 TC 118 Z9 118 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3381 EP 3384 DI 10.1029/95GL03268 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100069 ER PT J AU JOKIPII, JR KOTA, J GIACALONE, J HORBURY, TS SMITH, EJ AF JOKIPII, JR KOTA, J GIACALONE, J HORBURY, TS SMITH, EJ TI INTERPRETATION AND CONSEQUENCES OF LARGE-SCALE MAGNETIC VARIANCES OBSERVED AT HIGH HELIOGRAPHIC LATITUDE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; COSMIC-RAYS; FIELD AB We consider recent Ulysses Observations of the large-scale variances in the transverse components of the interplanetary magnetic field. A previously-suggested theory is shown to provide a good fit to the observed spatial variation and level of the fluctuations. The transport of cosmic rays in the heliosphere will be significantly affected by these fluctuations. In addition to impeding the inward, radial diffusive and drift, access of cosmic rays over the poles, the magnetic fluctuations imply a large latitudinal diffusion, caused primarily by the field-line mixing, or random walk. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. CALTECH,JET PROP LAB,PASADENA,CA. RP JOKIPII, JR (reprint author), UNIV ARIZONA,DEPT PLANETARY SCI,TUCSON,AZ 85721, USA. NR 22 TC 79 Z9 79 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3385 EP 3388 DI 10.1029/95GL03458 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100070 ER PT J AU GOLDSTEIN, BE NEUGEBAUER, M SMITH, EJ AF GOLDSTEIN, BE NEUGEBAUER, M SMITH, EJ TI ALFVEN WAVES, ALPHA-PARTICLES, AND PICKUP IONS IN THE SOLAR-WIND SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HYDROGEN; HELIUM AB Past studies of the properties of Alfven waves in the solar wind have indicated that (1) the amplitude of the velocity fluctuations is almost always smaller than expected on the basis of the amplitude of the field fluctuations, even when the anisotropy of the plasma is taken into account, and (2) the alpha particles often do not participate in the wave motions because they ''surf'' on the waves carried by the proton fluid. Ulysses data are used to demonstrate that (1) the discrepancy between the velocity and field fluctuations is greater at high heliographic latitudes than in the ecliptic plane, and (2) the alphas do participate in the waves, being either in phase or out of phase with the proton motions depending on whether the differential flow speed between the alphas and protons is greater than or less than the ''observed'' wave speed, V-wave = delta V B-0/delta B, as determined from the ratio of amplitudes of velocity and magnetic fluctuations. The possibility that the modification of Alfven wave propagation speed is due to pressure anisotropies resulting from pickup ion distributions is investigated. RP GOLDSTEIN, BE (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 13 TC 37 Z9 38 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3389 EP 3392 DI 10.1029/95GL03182 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100071 ER PT J AU GOLDSTEIN, BE SMITH, EJ BALOGH, A HORBURY, TS GOLDSTEIN, ML ROBERTS, DA AF GOLDSTEIN, BE SMITH, EJ BALOGH, A HORBURY, TS GOLDSTEIN, ML ROBERTS, DA TI PROPERTIES OF MAGNETOHYDRODYNAMIC TURBULENCE IN THE SOLAR-WIND AS OBSERVED BY ULYSSES AT HIGH HELIOGRAPHIC LATITUDES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STREAM STRUCTURE; ALFVEN WAVES; FLUCTUATIONS; EVOLUTION AB The Ulysses mission provides an opportunity to study the evolution of magnetohydrodynamic (MHD) turbulence in pure highspeed solar wind streams. The absence at high heliocentric latitudes of the strong shears in solar wind velocity generally present near the heliocentric current sheet allows investigation of how fluctuations in the magnetic field and plasma relax and evolve in the radially expanding solar wind. We report results of an analysis of the radial and latitudinal variation of the turbulence properties of the fluctuations, especially various plasma-field correlations, in high latitude regions. The results constrain current theories of the evolution of MHD turbulence in the solar wind. Compared to similar observations at 0.3 AU by Hellos, we find spectra that are similar in having a large frequency band with an f(1) power spectrum in the outward traveling component of the waves, followed at higher frequencies by a steeper spectrum. Ulysses observations establish that at high latitudes the turbulence is less evolved (i.e., has a smaller inertial range) than it is in the ecliptic at the same heliocentric distance, apparently due to the absence of strong velocity shear. Once Ulysses is in the polar coronal hole, properties of the turbulence appear to be determined by the heliocentric distance of the spacecraft rather than by its helio-latitude. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,LONDON,ENGLAND. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP GOLDSTEIN, BE (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91125, USA. RI Roberts, Dana/D-4625-2012; Goldstein, Melvyn/B-1724-2008 NR 31 TC 110 Z9 110 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3393 EP 3396 DI 10.1029/95GL03183 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100072 ER PT J AU TSURUTANI, BT HO, CM ARBALLO, JK GOLDSTEIN, BE BALOGH, A AF TSURUTANI, BT HO, CM ARBALLO, JK GOLDSTEIN, BE BALOGH, A TI LARGE-AMPLITUDE IMF FLUCTUATIONS IN COROTATING INTERACTION REGIONS - ULYSSES AT MIDLATITUDES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LION ROARS; MAGNETOSHEATH; WAVES AB Corotating Interaction Regions (CIRs), formed by high-speed corotating streams interacting with slow speed streams, have been examined from -20 degrees to -36 degrees heliolatitudes. The high-speed streams emanate from a polar coronal hole that Ulysses eventually becomes fully embedded in as it travels towards the south pole. We find that the trailing portion of the CIR, from the interface surface (IF) to the reverse shock (RS), contains both large amplitude transverse fluctuations and magnitude fluctuations. Similar fluctuations have been previously noted to exist within CIRs detected in the ecliptic plane, but their existence has not been explained. The normalized magnetic field component variances within this portion of the CIR and in the trailing high-speed stream are approximately the same, indicating that the fluctuations in the CIR are compressed Alfven waves. Mirror mode structures with lower intensities are also observed in the trailing portion of the CIR, presumably generated from a local instability driven by free energy associated with compression of the high-speed solar wind plasma. The mixture of these two modes (compressed Alfven waves and mirror modes) plus other modes generated by three wave processes (wave-shock interactions) lead to a lower Alfvenicity within the trailing portion of the CIR than in the high-speed stream proper. The results presented in this paper suggest a mechanism for generation of large amplitude B-z fluctuations within CIRs. Such phenomena have been noted to be responsible for the generation of moderate geomagnetic storms during the declining phase of the solar cycle. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. RP TSURUTANI, BT (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 10 TC 53 Z9 53 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3397 EP 3400 DI 10.1029/95GL03179 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100073 ER PT J AU HORBURY, TS BALOGH, A FORSYTH, RJ SMITH, EJ AF HORBURY, TS BALOGH, A FORSYTH, RJ SMITH, EJ TI OBSERVATIONS OF EVOLVING TURBULENCE IN THE POLAR SOLAR-WIND SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; ALFVENIC TURBULENCE; RADIAL EVOLUTION; MHD TURBULENCE; CASCADE MODEL; INTERMITTENCY; FLUCTUATIONS AB The Ulysses magnetic field experiment has measured the heliospheric magnetic field in solar wind flows from the Sun's Southern polar coronal hole over a wide range of heliolatitudes and distances. We present an analysis of more than one year of data, covering a latitude range of 40 degrees to 80 degrees S and a distance range of 4.0 to 1.7 AU. We extend an earlier analysis of Ulysses magnetic field data and, by calculating structure functions, demonstrate that the spectrum of fluctuations in the magnetic field changed along the orbit of Ulysses within polar flows and that this change is a result of the variation in Ulysses' distance from the Sun, rather than its latitude. We interpret this change as being due to the development of turbulence in the polar solar wind. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. RP HORBURY, TS (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, PRINCE CONSORT RD, LONDON SW7 2BZ, ENGLAND. NR 27 TC 40 Z9 41 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 DEC 1 PY 1995 VL 22 IS 23 BP 3401 EP 3404 DI 10.1029/95GL03550 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100074 ER PT J AU HORBURY, TS BALOGH, A FORSYTH, RJ SMITH, EJ AF HORBURY, TS BALOGH, A FORSYTH, RJ SMITH, EJ TI ANISOTROPY OF INERTIAL RANGE TURBULENCE IN THE POLAR HELIOSPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MINIMUM-VARIANCE; SOLAR-WIND; FLUCTUATIONS AB A variance analysis of high frequency, inertial range fluctuations in the polar magnetic field as recorded by the Ulysses spacecraft indicates that they are largely transverse to the ambient magnetic field direction and highly anisotropic. Despite large changes in the mean field direction caused by the presence of large amplitude Alfven waves, alignment of minimum variance vectors of 5 minute intervals of linearly detrended data with the mean field direction was good, with around 75% of minimum variance vectors lying within 26 degrees of the mean field direction during a typical 5 day interval. Such fluctuations transverse to the mean field have anisotropies - the ratio of power transverse to the field to that parallel - of around 30. We find a small tendency for the field-transverse fluctuations to become more isotropic with distance. Intervals whose minimum variance directions are not field-aligned appear to be indicative of a significantly different: type of fluctuations, with higher total variances and lower anisotropy. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP HORBURY, TS (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,PRINCE CONSORT RD,LONDON SW7 2BZ,ENGLAND. NR 20 TC 29 Z9 29 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3405 EP 3408 DI 10.1029/95GL03012 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100075 ER PT J AU HO, CM TSURUTANI, BT GOLDSTEIN, BE PHILLIPS, JL BALOGH, A AF HO, CM TSURUTANI, BT GOLDSTEIN, BE PHILLIPS, JL BALOGH, A TI TANGENTIAL DISCONTINUITIES AT HIGH HELIOGRAPHIC LATITUDES (SIMILAR-TO-80-DEGREES) SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND AB In this study, tangential discontinuities (TDs) near -80 degrees heliographic latitude have been studied. Based on our quantitative definitions, we find that the TDs may generally be divided into two clear types. There is a distinct population of TDs small (< 40 degrees) directional changes. About 19% of all high-latitude TDs are in this category. These types of TDs are found at the edges of mirror mode structures. The latter are presumed to be locally generated by ion anisotropies, based on examination of the mirror mode instability criteria. Another 50% of high latitude TDs are associated with large field directional changes (> 60 degrees). These TDs typically are found at the boundary between two streams. The discontinuities have large normals in the plane perpendicular to the background field, as might be expected for features generated by currents flowing along the field. These discontinuities usually have larger current intensities than those of the mirror-mode related TDs. The remainder of the discontinuities have angular changes which lie in between the mirror-mode-associated and the current-sheet-associated TDs. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. RP HO, CM (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 14 TC 18 Z9 19 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3409 EP 3412 DI 10.1029/95GL02981 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100076 ER PT J AU GOLDSTEIN, ML ROBERTS, DA GHOSH, S AF GOLDSTEIN, ML ROBERTS, DA GHOSH, S TI NUMERICAL SIMULATIONS OF LARGE-SCALE SOLAR-WIND FLUCTUATIONS OBSERVED BY ULYSSES AT HIGH HELIOGRAPHIC LATITUDES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ALFVEN WAVES; TURBULENCE; EVOLUTION; ORIGIN AB An analysis of Ulysses plasma and magnetic field data from the high southern latitude pass revealed that at large spatial scales corresponding to wave frequencies below 10(-5) Hz in the spacecraft frame, there is a transition from highly Alfvenic turbulence in all three spatial components of the fields to fluctuations which are Alfvenic only in field components transverse to the radial direction with uncorrelated radial magnetic and velocity fields. We find that the general properties of the turbulence can be simulated using a spectral method solution of the magnetohydrodynamic (MHD) equations only when certain types of initial conditions are employed. These simulations place constraints on conditions in the solar atmosphere that can generate the observed fluctuations. C1 APPL RES CORP,LANDOVER,MD 20785. RP GOLDSTEIN, ML (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 692,GREENBELT,MD 20771, USA. RI Roberts, Dana/D-4625-2012; Goldstein, Melvyn/B-1724-2008 NR 20 TC 3 Z9 3 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3413 EP 3416 DI 10.1029/95GL03412 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100077 ER PT J AU LIN, NG KELLOGG, PJ MACDOWALL, RJ BALOGH, A FORSYTH, RJ PHILLIPS, JL BUTTIGHOFFER, A PICK, M AF LIN, NG KELLOGG, PJ MACDOWALL, RJ BALOGH, A FORSYTH, RJ PHILLIPS, JL BUTTIGHOFFER, A PICK, M TI OBSERVATIONS OF PLASMA-WAVES IN MAGNETIC HOLES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; RADIO AB We report the first observations of Langmuir waves excited within magnetic holes, which are characterized by a depression of magnetic field strength. This phenomenon is very common in the solar wind. In addition to Langmuir waves, waves at a few kHz, which are typical of Doppler-shifted ion acoustic frequencies in the solar wind, and low frequency electromagnetic waves (below the electron cyclotron frequency) are sometimes observed simultaneously within the holes. In the holes with directional discontinuities at the boundary, the above plasma waves may occur at the edges of the holes. Possible physical mechanisms of the wave excitation are discussed. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,LONDON,ENGLAND. OBSERV MEUDON,F-92195 MEUDON,FRANCE. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP LIN, NG (reprint author), UNIV MINNESOTA,SCH PHYS & ASTRON,116 CHURCH ST SE,MINNEAPOLIS,MN 55455, USA. RI MacDowall, Robert/D-2773-2012 NR 14 TC 28 Z9 30 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3417 EP 3420 DI 10.1029/95GL03266 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100078 ER PT J AU THEJAPPA, G WENTZEL, DG MACDOWALL, RJ STONE, RG AF THEJAPPA, G WENTZEL, DG MACDOWALL, RJ STONE, RG TI UNUSUAL WAVE PHENOMENA NEAR INTERPLANETARY SHOCKS AT HIGH-LATITUDES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; PLASMA AB We report on several interplanetary shocks that are unusual because waves at about 10 Hz are highly electrostatic in the upstream region yet highly electromagnetic in the downstream region. These shocks, detected by the Unified Radio and Plasma Wave Experiment (URAP) on Ulysses are supercritical reverse shocks, which occurred predominantly at high heliographic latitudes. The level of wave activity is observed to be independent of the angle between the magnetic field and the shock normal, the Mach number, and the change in the ratio of ion thermal pressure to magnetic pressure from upstream to downstream regions. Since the energy in the upstream electrostatic waves is small compared to the downstream electromagnetic waves, mode conversion from electrostatic to electromagnetic at the shock is not a viable mechanism. The upstream and downstream waves are likely to be generated by separate mechanisms, with lower hybrid waves being the most probable candidates for the upstream waves and electromagnetic lower hybrid or whistlers for the downstream waves. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP THEJAPPA, G (reprint author), UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742, USA. RI MacDowall, Robert/D-2773-2012 NR 13 TC 6 Z9 6 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 1995 VL 22 IS 23 BP 3421 EP 3424 DI 10.1029/95GL03368 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TK191 UT WOS:A1995TK19100079 ER PT J AU MELILLO, JM BORCHERS, J CHANEY, J FISHER, H FOX, S HAXELTINE, A JANETOS, A KICKLIGHTER, DW KITTEL, TGF MCGUIRE, AD MCKEOWN, R NEILSON, R NEMANI, R OJIMA, DS PAINTER, T PAN, Y PARTON, WJ PIERCE, L PITELKA, L PRENTICE, C RIZZO, B ROSENBLOOM, NA RUNNING, S SCHIMEL, DS SITCH, S SMITH, T WOODWARD, I AF MELILLO, JM BORCHERS, J CHANEY, J FISHER, H FOX, S HAXELTINE, A JANETOS, A KICKLIGHTER, DW KITTEL, TGF MCGUIRE, AD MCKEOWN, R NEILSON, R NEMANI, R OJIMA, DS PAINTER, T PAN, Y PARTON, WJ PIERCE, L PITELKA, L PRENTICE, C RIZZO, B ROSENBLOOM, NA RUNNING, S SCHIMEL, DS SITCH, S SMITH, T WOODWARD, I TI VEGETATION ECOSYSTEM MODELING AND ANALYSIS PROJECT - COMPARING BIOGEOGRAPHY AND BIOGEOCHEMISTRY MODELS IN A CONTINENTAL-SCALE STUDY OF TERRESTRIAL ECOSYSTEM RESPONSES TO CLIMATE-CHANGE AND CO2 DOUBLING SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID ORGANIC-MATTER DYNAMICS; REGIONAL APPLICATIONS; GENERAL-MODEL; FOREST; PRODUCTIVITY; TEMPERATURE; BALANCE; PHOTOSYNTHESIS; SENSITIVITY; EXCHANGE AB We compare the simulations of three biogeography models (BIOME2, Dynamic Global Phytogeography Model (DOLY), and Mapped Atmosphere-Plant Soil System (MAPSS)) and three biogeochemistry models (BIOME-BGC (BioGeochemistry Cycles), CENTURY, and Terrestrial Ecosystem Model (TEM)) for the conterminous United States under contemporary conditions of atmospheric CO2 and climate. We also compare the simulations of these models under doubled CO2 and a range of climate scenarios. For contemporary conditions, the biogeography models successfully simulate the geographic distribution of major vegetation types and have similar estimates of area for forests (42 to 46% of the conterminous United States), grasslands (17 to 27%), savannas (15 to 25%), and shrublands (14 to 18%). The biogeochemistry models estimate similar continental-scale net primary production (NPP; 3125 to 3772 x 10(12) gC yr(-1)) and total carbon storage (108 to 118 x 10(15) gC) for contemporary conditions. Among the scenarios of doubled CO2 and associated equilibrium climates produced by the three general circulation models (Oregon State University (OSU), Geophysical Fluid Dynamics Laboratory (GFDL), and United Kingdom Meteorological Office (UKMO)), all three biogeography models show both gains and losses of total forest area depending on the scenario (between 38 and 53% of conterminous United States area). The only consistent gains in forest area with all three models (BIOME2, DOLY, and MAPSS) were under the GFDL scenario due to large increases in precipitation. MAPSS lost forest area under UKMO, DOLY under OSU, and BIOME2 under both UKMO and OSU, The variability in forest area estimates occurs because the hydrologic cycles of the biogeography models have different sensitivities to increases in temperature and CO2. However, in general, the biogeography models produced broadly similar results when incorporating both climate change and elevated CO2 concentrations. For these scenarios, the NPP estimated by the biogeochemistry models increases between 2% (BIOME-BGC with UKMO climate) and 35% (TEM with UKMO climate). Changes in total carbon storage range from losses of 33% (BIOME-BGC with UKMO climate) to gains of 16% (TEM with OSU climate). The CENTURY responses of NPP and carbon storage are positive and intermediate to the responses of BIOME-BGC and TEM. The variability in carbon cycle responses occurs because the hydrologic and nitrogen cycles of the biogeochemistry models have different sensitivities to increases in temperature and CO2. When the biogeochemistry models are run with the vegetation distributions of the biogeography models, NPP ranges from no response (BIOME-BGCwith all three biogeography model vegetations for UKMO climate) to increases of 40% (TEM with MAPSS vegetation for OSU climate). The total carbon storage response ranges from a decrease of 39% (BIOME-BGC with MAPSS vegetation for UKMO climate) to an increase of 32% (TEM with MAPSS vegetation for OSU and GFDL climates). The UKMO responses of BIOME-BGC with MAPSS vegetation are primarily caused by decreases in forested area and temperature-induced water stress, The OSU and GFDL responses of TEM with MAPSS vegetations are primarily caused by forest expansion and temperature-enhanced nitrogen cycling. C1 OREGON STATE UNIV,US FOREST SERV,CORVALLIS,OR 97333. US FOREST SERV,RALEIGH,NC 27606. LUND UNIV,S-22361 LUND,SWEDEN. NASA,WASHINGTON,DC 20546. UNIV ALASKA FAIRBANKS,ALASKA COOPERAT FISH & WILDLIFE RES UNIT,FAIRBANKS,AK 99775. COLORADO STATE UNIV,NAT RESOURCE ECOL LAB,FT COLLINS,CO 80523. UNIV MONTANA,MISSOULA,MT 59812. UNIV CALIF SANTA BARBARA,CTR REMOTE SENSING & ENVIRONM OPT,SANTA BARBARA,CA 93106. STANFORD UNIV,DEPT BIOL SCI,STANFORD,CA 94305. ELECT POWER RES INST,PALO ALTO,CA 94303. UNIV VIRGINIA,DEPT ENVIRONM SCI,CHARLOTTESVILLE,VA 22903. UNIV SHEFFIELD,DEPT ANIM & PLANT SCI,SHEFFIELD S10 2UQ,S YORKSHIRE,ENGLAND. UNIV CORP ATMOSPHER RES,BOULDER,CO 80307. UNIV COLORADO,INST ARCTIC & ALPINE RES,DEPT GEOL,BOULDER,CO 80309. RP MELILLO, JM (reprint author), MARINE BIOL LAB,CTR ECOSYST,WOODS HOLE,MA 02543, USA. RI Kittel, Timothy/F-2792-2011; Painter, Thomas/B-7806-2016; Ojima, Dennis/C-5272-2016; Woodward, Ian/B-7762-2008; Pan, Yude/F-6145-2015; Sitch, Stephen/F-8034-2015 OI Kittel, Timothy/0000-0002-4153-1006; Sitch, Stephen/0000-0003-1821-8561 NR 87 TC 252 Z9 263 U1 3 U2 68 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD DEC PY 1995 VL 9 IS 4 BP 407 EP 437 PG 31 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA TG011 UT WOS:A1995TG01100001 ER PT J AU FRIEDLINGSTEIN, P FUNG, I HOLLAND, E JOHN, J BRASSEUR, G ERICKSON, D SCHIMEL, D AF FRIEDLINGSTEIN, P FUNG, I HOLLAND, E JOHN, J BRASSEUR, G ERICKSON, D SCHIMEL, D TI ON THE CONTRIBUTION OF CO2 FERTILIZATION TO THE MISSING BIOSPHERIC SINK SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID ATMOSPHERIC CARBON-DIOXIDE; TROPICAL DEFORESTATION; DECOMPOSITION DYNAMICS; ELEVATED CO2; NITROGEN; CLIMATE; ECOSYSTEMS; SIMULATION; RESPONSES; MODEL AB A gridded biospheric carbon model is used to investigate the impact of the atmospheric CO2 increase on terrestrial carbon storage. The analysis shows that the calculated CO2 fertilization sink is dependent not just on the mathematical formulation of the ''beta factor'' but also on the relative controls of net primary productivity (NPP), carbon residence times, and resource availability. The modeled evolution of the biosphere for the period 1850-1990 shows an increasing lag between NPP and the heterotrophic respiration. The time evolution of the modeled biospheric sink (i.e., difference between enhanced NPP and enhanced respiration) does not match that obtained by deconvolution of the ice core CO2 time series. Agreement between the two is reasonable for the first half of the period, but during the recent decades the deconvoluted CO2 increase is much too fast to be explained by the CO2 fertilization effect only. Therefore other mechanisms than CO2 fertilization should also contribute to the missing sink. Our results suggest that about two thirds to three fourths of the 1850-1990 integrated missing sink is due to the CO2 greening of the biosphere. The remainder may be due to the increased level of nitrogen deposition starting around 1950. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. NASA,GODDARD INST SPACE SCI,NEW YORK,NY. RI John, Jasmin/F-8194-2012; Friedlingstein, Pierre/H-2700-2014 OI John, Jasmin/0000-0003-2696-277X; NR 76 TC 151 Z9 156 U1 2 U2 20 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD DEC PY 1995 VL 9 IS 4 BP 541 EP 556 DI 10.1029/95GB02381 PG 16 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA TG011 UT WOS:A1995TG01100010 ER PT J AU Michalowski, T Velichko, FP DiMartino, M Krugly, YN Kalashnikov, VG Shevchenko, VG Birch, PV Sears, WD Denchev, P Kwiatkowski, T AF Michalowski, T Velichko, FP DiMartino, M Krugly, YN Kalashnikov, VG Shevchenko, VG Birch, PV Sears, WD Denchev, P Kwiatkowski, T TI Models of four asteroids: 17 Thetis, 52 Europa, 532 Herculina, and 704 Interamnia SO ICARUS LA English DT Article ID STANDARD STARS; LIGHTCURVES; 532-HERCULINA; AXES AB New photoelectric observations for 17 Thetis (1985, 1993, 1994-95), 52 Europa (1992, 1994), 532 Herculina (1982, 1988, 1992), and 704 Interamnia (1993) carried out at seven observatories, are presented. Using all available lightcurves, the spin vectors, senses of rotation, and shapes of these asteroids have been determined or refined. (C) 1995 Academic Press, Inc. C1 ADAM MICKIEWICZ UNIV POZNAN,ASTRON OBSERV,PL-60286 POZNAN,POLAND. KHARKOV AM GORKII STATE UNIV,ASTRON OBSERV,KHARKOV 310022,UKRAINE. OSSERV ASTRON TORINO,I-10025 PINO TORINESE,ITALY. PERTH OBSERV,BICKLEY,WA 6076,AUSTRALIA. NATL ASTRON OBSERV,BU-4700 SMOLYAN,BULGARIA. RP Michalowski, T (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Shevchenko, Vasilij/H-1366-2011 OI Shevchenko, Vasilij/0000-0003-1000-223X NR 34 TC 8 Z9 8 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 1995 VL 118 IS 2 BP 292 EP 301 DI 10.1006/icar.1995.1192 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TQ863 UT WOS:A1995TQ86300003 ER PT J AU Rannou, P Cabane, M Chassefiere, E Botet, R McKay, CP Courtin, R AF Rannou, P Cabane, M Chassefiere, E Botet, R McKay, CP Courtin, R TI Titan's geometric albedo: Role of the fractal structure of the aerosols SO ICARUS LA English DT Article ID OPTICAL-PROPERTIES; AGGREGATE PARTICLES; HEATING RATES; ATMOSPHERE; MODELS; PHOTOLYSIS; CLUSTERS; GROWTH AB The collisional mechanisms of Titan's aerosols may lead to a fractal structure in which the aerosols are built by the aggregation of spherical submicrometer particles (monomers). In this initial study of the problem, the optical behavior of these aggregates is modeled assuming that each monomer radiates a dipole field in response to the incident radiation including the radiated fields of all the other elements in the aggregate. This dipole approximation, valid if the monomer radius is smaller than the wavelength, is used to calculate the scattering and extinction efficiencies of such aerosol particles, which are assumed to be composed of tholins. By applying the two-stream approximation for radiative transfer to the vertical distribution of aerosols obtained by microphysical modeling, we compute the geometric albedo of Titan. Computed values and observational values of the albedo are compared for wavelengths from 0.22 to 1.0 mu m, and the effects of parameters, such as the fractal dimension of aerosols, their formation altitude or mass production rate, and, in addition, the methane abundance, are investigated. The hypothesized fractal structure of particles can explain both the visible and the UV albedos. In previous models these measurements could only be matched simultaneously under the assumption of a bimodal population. For a fractal dimension D-f approximate to 2 in the settling region, corresponding to a growth governed by cluster-cluster aggregation, the computed albedo in the near-UV range matches the observations. A good fit between measurement and calculated albedo is obtained, for a formation altitude z(0) = 535 km, over the whole wavelength range by adjusting the absorption coefficient of the particles within a factor of two from that of tholins and a production rate between 0.2 and 1.5 times 3.5 x 10(-13) kg m(-2) sec(-1). Lower formation altitudes,like our preferred case, z(0) = 385 km, cannot be investigated in the UV range due to limitations of the dipolar approximation, but we expect this case to give the same behavior. (C) 1995 Academic Press, Inc. C1 CNRS,SERV AERON,F-91371 VERRIERES BUISSON,FRANCE. UNIV PARIS 11,LAB PHYS SOLIDES,F-91405 ORSAY,FRANCE. NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035. OBSERV PARIS,CNRS,LAB RECH SPATIALE,F-92195 MEUDON,FRANCE. RP Rannou, P (reprint author), UNIV PARIS 06,SERV AERON,TOUR 15,B102,PL JUSSIEU,F-75005 PARIS,FRANCE. RI RANNOU, Pascal/I-9059-2012 NR 27 TC 93 Z9 93 U1 0 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 1995 VL 118 IS 2 BP 355 EP 372 DI 10.1006/icar.1995.1196 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TQ863 UT WOS:A1995TQ86300007 ER PT J AU Goldreich, P Rappaport, N Sicardy, B AF Goldreich, P Rappaport, N Sicardy, B TI Single-sided shepherding SO ICARUS LA English DT Article ID PLANETARY RINGS; DENSITY WAVES; SHARP EDGES; DYNAMICS AB Narrow ringlets are observed to form at isolated Lindblad resonances in recent simulations (J. Hanninen and H. Sale, Icarus 108, 325-346 (1994) and 117, 435-438 (1995)), Our remarks are directed toward the interpretation of this phenomenon, Ringlet formation is a consequence of the negative angular momentum luminosity promoted by satellite perturbations of the streamlines of particle flow, Contraction halts once the surface density reaches a value such that the angular momentum luminosity vanishes, Our estimate for the formation time, t(f) similar to (M(p)/M(s))(1/2)Omega(-1), for low order resonances in optically thin rings is consistent with the results of the simulations, Ringlets drift across the width of resonance, W similar to (M(s)/M(p))(1/2)a, as a result of the unbalanced satellite torque, This occurs on the much longer timescale t(d) similar to (M(p)/M(s))Omega(-1) and cannot be observed in current simulations. (C) 1995 Academic Press, Inc. C1 JET PROP LAB,PASADENA,CA 91109. INST UNIV FRANCE,OBSERV PARIS,F-92195 MEUDON,FRANCE. RP Goldreich, P (reprint author), CALTECH,PASADENA,CA 91125, USA. NR 15 TC 20 Z9 20 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 1995 VL 118 IS 2 BP 414 EP 417 DI 10.1006/icar.1995.1200 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TQ863 UT WOS:A1995TQ86300011 ER PT J AU Buratti, BJ Mosher, JA Terrile, RJ AF Buratti, BJ Mosher, JA Terrile, RJ TI First observational evidence for condensation of Io's SO2 atmosphere on the nightside SO ICARUS LA English DT Article ID GLOBAL DISTRIBUTION; SOLID SULFUR; SATELLITE IO; METEOROLOGY; REFLECTANCE; PHOTOMETRY; STABILITY; PRESSURE; ECLIPSE; LO AB xIn this note we search for the condensation of Io's tenuous SO2 atmosphere on the night- (Jupiter-illuminated) side of the satellite by observing color changes on Voyager 2 images. We find that the nightside of Io is consistently bluer than the same regions viewed under solar illumination. The most likely explanation for this color change is the condensation of SO2 frost. This measurement is the first observational evidence for such condensation. (C) 1995 Academic Press, Inc. RP Buratti, BJ (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR 183-501,PASADENA,CA 91109, USA. NR 31 TC 10 Z9 10 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 1995 VL 118 IS 2 BP 418 EP 422 DI 10.1006/icar.1995.1201 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TQ863 UT WOS:A1995TQ86300012 ER PT J AU ELBULUK, ME KANKAM, MD AF ELBULUK, ME KANKAM, MD TI MOTOR DRIVE TECHNOLOGIES FOR THE POWER-BY-WIRE (PEW) PROGRAM - OPTIONS, TRENDS AND TRADEOFFS .2. POWER ELECTRONIC CONVERTERS AND DEVICES SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB This is the second of two papers on the motor drive technology options for the Power-By-Wire (PEW). The organization of this paper is based on the four components of the electrical actuator (EA) system and the options available to suit the PEW program as given in the PEW studies. The first paper [1] discussed the options available for the motor and the controller parts of a drive. This paper discusses the power electronic converter and device options. The power converter options are divided into hard-, snubbered- and soft-switching converters. The power device options are the MOSFET, the Insulated Gate Transistor (IGT), the gate turn-off thyristor (GTO) and the MOS Controlled Thyristor (MCT). C1 NASA,LEWIS RES CTR,DIV POWER TECHNOL,CLEVELAND,OH 44135. RP ELBULUK, ME (reprint author), UNIV AKRON,DEPT ELECT ENGN,AKRON,OH 44325, USA. NR 25 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD DEC PY 1995 VL 10 IS 12 BP 31 EP 36 DI 10.1109/62.480829 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA TJ029 UT WOS:A1995TJ02900007 ER PT J AU Noor, AK AF Noor, AK TI UVA Center for Computational Structures Technology SO IEEE COMPUTATIONAL SCIENCE & ENGINEERING LA English DT Editorial Material RP Noor, AK (reprint author), NASA,LANGLEY RES CTR,CTR COMPUTAT STRUCT TECHNOL,MAIL STOP 369,HAMPTON,VA 23681, USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 1070-9924 J9 IEEE COMPUT SCI ENG JI IEEE Comput. Sci. Eng. PD WIN PY 1995 VL 2 IS 4 BP 10 EP 14 DI 10.1109/99.476361 PG 5 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Mathematics, Applied SC Computer Science; Engineering; Mathematics GA TK502 UT WOS:A1995TK50200005 ER PT J AU MASON, C MATWIN, S AF MASON, C MATWIN, S TI ENVIRONMENTAL APPLICATIONS OF AL SO IEEE EXPERT-INTELLIGENT SYSTEMS & THEIR APPLICATIONS LA English DT Editorial Material C1 UNIV OTTAWA,DEPT COMP SCI,OTTAWA,ON K1N 6N5,CANADA. RP MASON, C (reprint author), NASA,AMES RES CTR,DIV INFORMAT SCI 2692,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0885-9000 J9 IEEE EXPERT JI IEEE Expert-Intell. Syst. Appl. PD DEC PY 1995 VL 10 IS 6 BP 12 EP 13 DI 10.1109/MEX.1995.483007 PG 2 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA TG278 UT WOS:A1995TG27800004 ER PT J AU STOKER, CR BARCH, DR HINE, BP BARRY, J AF STOKER, CR BARCH, DR HINE, BP BARRY, J TI ANTARCTIC UNDERSEA EXPLORATION USING OR ROBOTIC SUBMARINE WITH TELEPRESENCE USER-INTERFACE SO IEEE EXPERT-INTELLIGENT SYSTEMS & THEIR APPLICATIONS LA English DT Article ID MCMURDO SOUND; COMMUNITIES; PATTERNS C1 MONTEREY BAY AQUARIUM RES INST,MONTEREY,CA 93940. RP STOKER, CR (reprint author), NASA,AMES RES CTR,MS 235-3,MOFFETT FIELD,CA 94035, USA. NR 14 TC 13 Z9 13 U1 0 U2 3 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0885-9000 J9 IEEE EXPERT JI IEEE Expert-Intell. Syst. Appl. PD DEC PY 1995 VL 10 IS 6 BP 14 EP 23 DI 10.1109/64.483008 PG 10 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA TG278 UT WOS:A1995TG27800005 ER PT J AU SHORT, NM CROMP, RF CAMPBELL, WJ TILTON, JC LEMOIGNE, JJ FEKETE, G NETANYAHU, NS WICHMANN, K LIGON, WB AF SHORT, NM CROMP, RF CAMPBELL, WJ TILTON, JC LEMOIGNE, JJ FEKETE, G NETANYAHU, NS WICHMANN, K LIGON, WB TI MISSION TO PLANET EARTH - AL VIEWS THE WORLD SO IEEE EXPERT-INTELLIGENT SYSTEMS & THEIR APPLICATIONS LA English DT Article C1 CLEMSON UNIV,CLEMSON,SC 29631. RP SHORT, NM (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 935,GREENBELT,MD 20771, USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0885-9000 J9 IEEE EXPERT JI IEEE Expert-Intell. Syst. Appl. PD DEC PY 1995 VL 10 IS 6 BP 24 EP 34 DI 10.1109/64.483009 PG 11 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA TG278 UT WOS:A1995TG27800006 ER PT J AU MASON, CL AF MASON, CL TI AN INTELLIGENT ASSISTANT FOR NUCLEAR TEST BAN TREATY VERIFICATION SO IEEE EXPERT-INTELLIGENT SYSTEMS & THEIR APPLICATIONS LA English DT Article RP MASON, CL (reprint author), NASA,AMES RES CTR,DIV INFORMAT SCI 2692,MOFFETT FIELD,CA 94035, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0885-9000 J9 IEEE EXPERT JI IEEE Expert-Intell. Syst. Appl. PD DEC PY 1995 VL 10 IS 6 BP 42 EP 49 DI 10.1109/64.483116 PG 8 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA TG278 UT WOS:A1995TG27800008 ER PT J AU PANCAKE, CM SIMMONS, ML YAN, JC AF PANCAKE, CM SIMMONS, ML YAN, JC TI PERFORMANCE EVALUATION TOOLS FOR PARALLEL AND DISTRIBUTED SYSTEMS SO IEEE PARALLEL & DISTRIBUTED TECHNOLOGY LA English DT Editorial Material C1 LOS ALAMOS NATL LAB,COMP RES & APPLICAT GRP,LOS ALAMOS,NM 87544. NASA,AMES RES CTR,DIV NUMER AERODYNAM SIMULAT SYST,MOFFETT FIELD,CA 94035. RP PANCAKE, CM (reprint author), OREGON STATE UNIV,CORVALLIS,OR 97331, USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 1063-6552 J9 IEEE PARALL DISTRIB JI IEEE Parallel Distrib. Technol. PD WIN PY 1995 VL 3 IS 4 BP 14 EP & PG 0 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA TE024 UT WOS:A1995TE02400004 ER PT J AU SARUKKAI, SR MEHRA, P BLOCK, RJ AF SARUKKAI, SR MEHRA, P BLOCK, RJ TI AUTOMATED SCALABILITY ANALYSIS OF MESSAGE-PASSING PARALLEL PROGRAMS SO IEEE PARALLEL & DISTRIBUTED TECHNOLOGY LA English DT Article AB To characterize large-scale performance, this scalability analysis toolkit constructs augmented parse trees. APTs combine two key data structures: annotated parse trees and communication phase graphs. By parsing the APT, the toolkit supports simulation, abstract interpretation, and complexity analysis. C1 UNIV ILLINOIS,DEPT COMP SCI,CHICAGO,IL 61801. RP SARUKKAI, SR (reprint author), NASA,AMES RES CTR,RECOM TECHNOL,MS 269-3,MOFFETT FIELD,CA 94035, USA. NR 14 TC 6 Z9 6 U1 1 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 1063-6552 J9 IEEE PARALL DISTRIB JI IEEE Parallel Distrib. Technol. PD WIN PY 1995 VL 3 IS 4 BP 21 EP 32 DI 10.1109/88.473611 PG 12 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA TE024 UT WOS:A1995TE02400005 ER PT J AU OBERG, J AF OBERG, J TI RUSSIA SPACE PROGRAM SO IEEE SPECTRUM LA English DT Article RP OBERG, J (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 9 TC 1 Z9 1 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD DEC PY 1995 VL 32 IS 12 BP 18 EP 35 DI 10.1109/6.477446 PG 18 WC Engineering, Electrical & Electronic SC Engineering GA TH237 UT WOS:A1995TH23700011 ER PT J AU Fijany, A Jensen, MA RahmatSamii, Y Barhen, J AF Fijany, A Jensen, MA RahmatSamii, Y Barhen, J TI A massively parallel computation strategy for FDTD: Time and space parallelism applied to electromagnetics problems SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article ID PARTIAL-DIFFERENTIAL EQUATIONS; SCATTERING; ALGORITHMS AB In this paper, we present a novel strategy for incorporating massive parallelism into the solution of Maxwell's equations using finite-difference time-domain methods. In a departure from previous techniques wherein spatial parallelism is used, our approach exploits massive temporal parallelism by computing all of the time steps in parallel. Furthermore, in contrast to other methods which appear to concentrate on explicit schemes such as Yee's algorithm, our strategy uses the implicit Crank-Nicolson technique which provides superior numerical properties. We show that the use of temporal parallelism results in algorithms which offer a massive degree of coarse grain parallelism with minimum communication and synchronization requirements. Due to these features, the time-parallel algorithms are particularly suitable for implementation on emerging massively parallel multiple instruction-multiple data (MIMD) architectures. The methodology is applied to a circular cylindrical configuration, which serves as a testbed problem for the approach, to demonstrate the massive parallelism that can be exploited. We also discuss the generalization of the methodology for more complex problems. C1 BRIGHAM YOUNG UNIV, DEPT ELECT & COMP ENGN, PROVO, UT 84602 USA. UNIV CALIF LOS ANGELES, DEPT ELECT ENGN, LOS ANGELES, CA 90024 USA. RP Fijany, A (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 31 TC 12 Z9 12 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD DEC PY 1995 VL 43 IS 12 BP 1441 EP 1449 DI 10.1109/8.475935 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA TK500 UT WOS:A1995TK50000014 ER PT J AU Raab, FH Joughin, IR AF Raab, FH Joughin, IR TI Signal processing for through-the-earth radio communication SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article AB Through-the-earth (TE) propagation subjects a radio signal to considerable attenuation. The uplink signal must, however, be detected in the presence of full-strength atmospheric noise. Consequently, through-the-earth communication systems are generally restricted to relatively low data rates. The electromagnetic characteristics of the TE signal differ from those of the surface-propagating noise. In addition, much of the energy in low-frequency noise is contained in discrete impulses. This paper describes an integrated combination of adaptive noise cancellation (ANC), maximum-likelihood detection (MLD), nonlinear processing (NLP), and decision-aided feedback (DAFB) that can be used to combat atmospheric noise in TEC systems. Tests with real VLF noise demonstrate a 10-to-24 dB improvement in SNR. The reduced effective noise level allows higher data rates, greater depth of operation, smaller transmitters, and/or smaller antennas. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Raab, FH (reprint author), GREEN MT RADIO RES CO,COLCHESTER,VT 05446, USA. RI Joughin, Ian/A-2998-2008 OI Joughin, Ian/0000-0001-6229-679X NR 25 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD DEC PY 1995 VL 43 IS 12 BP 2995 EP 3003 DI 10.1109/26.477502 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA TL840 UT WOS:A1995TL84000027 ER PT J AU GAWRONSKI, WK RACHO, CS MELLSTROM, JA AF GAWRONSKI, WK RACHO, CS MELLSTROM, JA TI APPLICATION OF THE LQG AND FEEDFORWARD CONTROLLERS TO THE DEEP SPACE NETWORK ANTENNAS SO IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY LA English DT Note AB The controller development and the tracking performance evaluation for NASA's Deep Space Network antennas are presented, A command preprocessor, LQG (linear quadratic Gaussian) controller, feedforward controller, and their combination are designed, built, analyzed, and tested. The antenna exhibits nonlinear behavior when the input to the antenna and/or the derivative of this input exceeds the imposed limits; for slewing and acquisition commands, these limits are typically violated. A command preprocessor was designed to insure that the antenna behaves linearly, just to prevent nonlinear limit cycling. The estimator model for the LQG controller was identified from the data obtained from the field test, Based on an LQG balanced representation, a reduced-order LQG controller was obtained. The feedforward controller and the combination of the LQG and feedforward controller were also investigated, The performance of the controllers was evaluated with the tracking errors (due to following a command) and the disturbance errors (due to the disturbances acting on the antenna), The LQG controller has good disturbance rejection properties and satisfactory tracking errors, The feedforward controller has small tracking error but poor disturbance rejection properties. The combined LQG and feedforward controller exhibits small tracking errors, as well as good disturbance rejection properties. The cost of this performance, however, is found in the complexity of the controller. RP GAWRONSKI, WK (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 10 TC 14 Z9 19 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1063-6536 J9 IEEE T CONTR SYST T JI IEEE Trans. Control Syst. Technol. PD DEC PY 1995 VL 3 IS 4 BP 417 EP 421 DI 10.1109/87.481966 PG 5 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA TG967 UT WOS:A1995TG96700006 ER PT J AU Dib, NI Simons, RN Katehi, LPB AF Dib, NI Simons, RN Katehi, LPB TI New uniplanar transitions for circuit and antenna applications SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article; Proceedings Paper CT 1995 International Microwave Symposium (IMS)/Millimeter-Wave Monolithic Circuits Symposium (MMWMCS) CY MAY 14-19, 1995 CL ORLANDO, FL AB New uniplanar microstrip-to-slotline, microstrip-to-coplanar strips (CPS) and microstrip-to-coplanar waveguide (CPW) transitions for MIC/MMIC and slotline antennas for phased array applications are described. Such transitions are compact and suitable to be used in an open environment or inside a package or a multichip module. The transitions share the concept of using a balun which consists of two microstrip lines connected to a slotline through a pair of coupled microstrips. In this paper, the transitions are studied theoretically using the Finite Difference Time Domain (FDTD) technique and measured experimentally using an HP8510C Network Analyzer. For a back-to-back microstrip-to-slotline transition, an insertion loss of less than 1.3 dB per transition is achieved over a 49% bandwidth with a minimum of 0.6 dB around the design frequency. C1 UNIV MICHIGAN,RADIAT LAB,ANN ARBOR,MI 48109. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RI Dib, Nihad/M-4918-2015; OI Dib, Nihad/0000-0002-2263-5512 NR 15 TC 39 Z9 40 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD DEC PY 1995 VL 43 IS 12 BP 2868 EP 2873 DI 10.1109/22.475648 PN 2 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA TN476 UT WOS:A1995TN47600023 ER PT J AU Johnston, AH Rax, BG Lee, CI AF Johnston, AH Rax, BG Lee, CI TI Enhanced damage in linear bipolar integrated circuits at low dose rate SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE ID HOLE TRANSPORT; TRANSISTORS AB Enhanced damage at low dose rates was investigated for several different types of linear integrated circuits that were fabricated with conventional junction isolation. Although both npn and pnp transistors exhibit increased damage at low dose rate, the effect is far greater for substrate and lateral pnp transistors from these technologies. The saturation level of damage at high doses was also found to be far greater under low dose rate conditions than at high dose rates. A model for this behavior was developed that is consistent with earlier studies of MOS field oxides under low-field conditions, and accounts for the increased enhanced damage in pnp The transistors. RP Johnston, AH (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 17 TC 86 Z9 95 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 1650 EP 1659 DI 10.1109/23.488762 PN 1 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000017 ER PT J AU Shaw, DC Swift, GM Johnston, AH AF Shaw, DC Swift, GM Johnston, AH TI Radiation evaluation of an advanced 64Mb 3.3V DRAM and insights into the effects of scaling on radiation hardness SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE ID INTEGRATED-CIRCUITS; TRANSISTORS AB In this paper, total ionizing dose radiation evaluations of the Micron 64 Mb 3.3 V, fast page mode DRAM and the IBM LUNA-ES 16 Mb DRAM are presented. The effects of scaling on total ionizing dose radiation hardness are studied utilizing test structures and a series of 16 Mb DRAMs with different feature sizes from the same manufacturing line. General agreement was found between the threshold voltage shifts of 16 Mb DRAM test structures and the threshold voltage measured on complete circuits using retention time measurements. Retention time measurement data from early radiation doses are shown that allow internal failure modes to be distinguished. RP Shaw, DC (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 1674 EP 1680 DI 10.1109/23.488765 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000020 ER PT J AU Lee, CI Rax, BG Johnston, AH AF Lee, CI Rax, BG Johnston, AH TI Hardness assurance and testing techniques for high resolution (12- to 16-bit) analog-to-digital converters SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE ID A/D CONVERTERS; RADIATION AB This paper discusses hardness assurance and testing techniques to test and evaluate total dose radiation degradation of high resolution A/D converters. A 16-bit converter with internal calibration is compared with older designs (12-/14-bit) that use more conventional architectures. The results show that measurements of de parameters and static linearity at major code transitions should be adequate for hardness assurance testing, with considerable cost savings compared to full dynamic or all-codes testing. The failure level of CMOS and BiCMOS converters depends on dose rate in a complicated way that is not adequately addressed by high-temperature annealing. Tests at low dose rates -below 0.01 rad(Si)/s- are recommended for space applications of these technologies. RP Lee, CI (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 8 TC 8 Z9 14 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 1681 EP 1688 DI 10.1109/23.488766 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000021 ER PT J AU Smith, EC Stassinopoulos, EG LaBel, K Brucker, G Seidlick, CM AF Smith, EC Stassinopoulos, EG LaBel, K Brucker, G Seidlick, CM TI Application of a diffusion model to SEE cross sections of modern devices SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE ID CHARGE AB A diffusion model, based on extensions of the analysis by Kirkpatrick (1979), appears to explain a number of ''anomalous'' features of the cross section measured as a function of the LET of the incident ions in some modern devices. In contrast, heuristic corrections are needed to fit the data with models based on drift of charge to and in a rectangular parallepiped. In particular the following features of the accelerator measurements are explained. (1) Cross sections at normal incidence much larger than the dimensions of depletion regions. (2) As the LET of the ion is increased above the onset threshold, the cross section increases gradually; it is not a step function. The cross section does not approach an asymptote, even at normal incidence. (3) There are discontinuities in the cross section versus effective LET when ion species are changed. (4) Cross section curves are approximated with Weibull distributions. The model is applicable when cross sections at large LET values are small (similar to 10 mu m(2)). A procedure for calculating upset rates is developed, although it is not implemented at this time. The model is preliminary. The ultimate limits of applicability and the transition to the standard rectangular parallepiped (RPP) model have yet to be established. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20770. HUGHES ST SYST,GREENBELT,MD 20770. NR 12 TC 24 Z9 24 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 1772 EP 1779 DI 10.1109/23.488778 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000033 ER PT J AU Dussault, H Howard, JW Block, RC Stapor, WJ Knudson, AR McDonald, PT Pinto, MR AF Dussault, H Howard, JW Block, RC Stapor, WJ Knudson, AR McDonald, PT Pinto, MR TI High-energy heavy-ion-induced charge transport across multiple junctions SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE ID COLLECTION; SIMULATION AB High-energy heavy ion experiments and numerical simulations show that two or more junctions bridged by an ion track respond in a coupled manner. The potential difference across the structure strongly affects the amount of charge collected at each of the junctions. Experiments with 1.7 GeV Au-197 ions indicate that, for emitter biases less than or equal to 0.0 volts and potential differences of 5 or more volts, more charge may be collected at a junction than was initially deposited by the ion. Simulations show that, when an ion track intersects multiple junctions of a device, the responses of the individual junctions cannot be modeled independently of each other. Simulation and experimental results indicate that charge transport in a multiple junction structure cannot be modeled using simple geometry or funneling assumptions. C1 ROME LAB,RL ERDA,GRIFFISS AFB,NY 13441. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,MSFC EL54,HUNTSVILLE,AL 35812. USN,RES LAB,WASHINGTON,DC 20375. SACHS FREEMAN ASSOCIATES INC,LANDOVER,MD 20785. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP Dussault, H (reprint author), RENSSELAER POLYTECH INST,TROY,NY 12180, USA. NR 10 TC 3 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 1780 EP 1788 DI 10.1109/23.488779 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000034 ER PT J AU Marshall, PW Dale, CJ Weatherford, TR LaMacchia, M Label, KA AF Marshall, PW Dale, CJ Weatherford, TR LaMacchia, M Label, KA TI Particle-induced mitigation of SEU sensitivity in high data rate GaAs HIGFET technologies SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE AB Proton and heavy ion data on two GaAs HIGFET logic families, one source coupled (SCFL) and the other complementary (C-HIGFET), show the importance of dynamic testing and develop a new technique for mitigating SEU sensitivity by minimizing charge enhancement effects. C1 SFA INC,LANDOVER,MD 20785. MOTOROLA INC,PHOENIX,AZ. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Marshall, PW (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 13 TC 15 Z9 17 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 1844 EP 1849 DI 10.1109/23.489225 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000043 ER PT J AU LaBel, KA Barry, RK Castell, K Kim, HS Seidleck, CM AF LaBel, KA Barry, RK Castell, K Kim, HS Seidleck, CM TI Implications of single event effect characterization of hybrid DC-DC converters and a solid state power controller SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE AB As part of National Aeronautics and Space Administration (NASA)/Goddard Space Flight Center's (GSFC) efforts in supporting spaceflight qualification for multiple programs, single event effect (SEE) characterization of various DC-DC power converters as well as a solid-state power controller (SSPC) was undertaken. The implications of these test results are further discussed. C1 HUGHES ST SYST CORP,GREENBELT,MD. RP LaBel, KA (reprint author), NASA,GSFC,CODE 735-1,GREENBELT,MD 20771, USA. NR 6 TC 6 Z9 7 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 1957 EP 1963 DI 10.1109/23.489240 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000058 ER PT J AU Adolphsen, J Barth, JL Stassinopoulos, EG Gruner, T Wennersten, M LaBel, KA Seidleck, CM AF Adolphsen, J Barth, JL Stassinopoulos, EG Gruner, T Wennersten, M LaBel, KA Seidleck, CM TI Single event upset rates on 1 Mbit and 256 Kbit memories: CRUX experiment on APEX SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE ID PROTON AB This paper presents the results from the CRUX experiment on the Air Force APEX satellite. The experiment monitors single event upsets on screened commercial 256 Kbit and 1 Mbit SRAMs. It is shown that trapped protons dominate the single event upset rates, as evidenced by correlation with measured proton flux peaks and with flux contours calculated with the AP8 model. Pitfalls of using generic ground test data are made clearly evident. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. HUGHES ST SYST CORP,GREENBELT,MD 20706. RP Adolphsen, J (reprint author), UNISYS,LANHAM,MD 20706, USA. NR 28 TC 11 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 1964 EP 1974 DI 10.1109/23.489241 PN 1 PG 11 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000059 ER PT J AU Shinn, JL Cucinotta, FA Wilson, JW Badhwar, GD ONeill, PM Badavi, FF AF Shinn, JL Cucinotta, FA Wilson, JW Badhwar, GD ONeill, PM Badavi, FF TI Effects of target fragmentation on evaluation of LET spectra from space radiation in low-earth orbit (LEO) environment: Impact on SEU predictions SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE ID MODEL AB Recent improvements in the radiation transport code HZETRN/BRYNTRN and galactic cosmic ray environmental model have provided an opportunity to investigate the effects of target fragmentation on estimates of single event upset (SEU) rates for spacecraft memory devices. Since target fragments are mostly of very low energy, an SEU prediction model has been derived in terms of particle energy rather than linear energy transfer (LET) to account for nonlinear relationship between range and energy. Predictions are made for SEU rates observed on two Shuttle flights, each at low and high inclination orbit. Corrections due to track structure effects are made for both high energy ions with track structure larger than device sensitive volume and for low energy ions with dense track where charge recombination is important. Results indicate contributions from target fragments are relatively important at large shield depths (or any thick structure material) and at low inclination orbit. Consequently, a more consistent set of predictions for upset rates observed in these two flights is reached when compared to an earlier analysis with CREME model. It is also observed that the errors produced by assuming linear relationship in range and energy in the earlier analysis have fortuitously canceled out the errors for not considering target fragmentation and track structure effects. C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. CHRISTOPHER NEWPORT UNIV,NEWPORT NEWS,VA 23606. RP Shinn, JL (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 28 TC 9 Z9 9 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 2017 EP 2025 DI 10.1109/23.489248 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000066 PM 11541192 ER PT J AU Bogorad, A Bowman, C Dennis, A Beck, J Lang, D Herschitz, R Buehler, M Blaes, B Martin, D AF Bogorad, A Bowman, C Dennis, A Beck, J Lang, D Herschitz, R Buehler, M Blaes, B Martin, D TI Integrated environmental monitoring system for spacecraft SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 32nd Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 17-21, 1995 CL MADISON, WI SP IEEE AB This paper describes an integrated space environmental monitoring system for geosynchronous satellites. The system provides measurements of surface charging, internal charging, and total dose radiation from the space environment. It is installed on seven of Martin Marietta's commercial communications spacecraft, which are scheduled for launch in the near future. There are two components: an internal charge monitor, and a surface charge detector. Total weight is less than one pound; power consumption, about 0.5 watt. Charging flux information from these detectors will permit evaluation of the effects of internal charging on electronic PC boards and will lead to the development of reliable, low-weight methods to detect on-orbit spacecraft charging events and to control charging and discharging. C1 CALTECH,JET PROPULS LAB,PASADENA,CA 91109. HALCYON MICROELECTR INC,IRWINDALE,CA 91706. RP Bogorad, A (reprint author), LOCKHEED MARTIN ASTRO SPACE,POB 800,PRINCETON,NJ 08543, USA. NR 13 TC 25 Z9 31 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 2051 EP 2057 DI 10.1109/23.489252 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN390 UT WOS:A1995TN39000070 ER PT J AU Stassinopoulos, EG Brucker, GJ Stauffer, CA Meulenberg, A AF Stassinopoulos, EG Brucker, GJ Stauffer, CA Meulenberg, A TI Chronology of generation, variation, and disappearance of a second proton belt as determined by effects in electronic devices SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID RADIATION AB This paper presents an analysis of SEU data obtained from memory devices on the CRRES (Combined Release and Radiation Effects Satellite) spacecraft, It provides a dynamic picture of the newly identified second peak of the trapped proton belt in the equatorial region between approximately 2.0-2.8 Earth radii, In previous work, it was stated that injection of solar flare protons from the major flare of March 1991 generated this secondary belt which appears to have survived at least up to the demise of CRRES (October 12, 1991), The results of this study show that the radiation responsible for the observed effects existed intermittently in that region of space from the very beginning of the mission, that is July 27, 1990, during a period when there was no significant high energy Rare activity (about 4.5 months), and then disappeared for three months until it reappeared again with the March 1991 flare. C1 SES,GREENBELT,MD. COMSAT LABS,CLARKSBURG,MD 20871. RP Stassinopoulos, EG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. RI Meulenberg, Andrew/K-4194-2012 OI Meulenberg, Andrew/0000-0003-3570-4705 NR 22 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1995 VL 42 IS 6 BP 2229 EP 2235 DI 10.1109/23.489419 PN 2 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA TN392 UT WOS:A1995TN39200009 ER PT J AU HUANG, Y PALANIAPPAN, K ZHUANG, XH CAVANAUGH, JE AF HUANG, Y PALANIAPPAN, K ZHUANG, XH CAVANAUGH, JE TI OPTIC FLOW-FIELD SEGMENTATION AND MOTION ESTIMATION USING A ROBUST GENETIC PARTITIONING ALGORITHM SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE MOTION ESTIMATION; OPTIC FLOW FIELD SEGMENTATION; LINEAR REGRESSION; ROBUST ESTIMATION; GENETIC ALGORITHM ID RECOVERING 3-D MOTION; 3-DIMENSIONAL MOTION; SMOOTHNESS CONSTRAINTS; INHERENT AMBIGUITIES; COMPUTER VISION; OBJECTS; IMAGES; RECONSTRUCTION; SEQUENCES; SCENE AB Optic flow motion analysis represents an important family of visual information processing techniques In computer vision, Segmenting an optic now field into coherent motion groups and estimating each underlying motion is a very challenging task when the optic flow field is projected from a scene of several independently moving objects, The problem is further complicated if the optic flow data are noisy and partially incorrect, In this paper, we present a novel framework for determining such optic flow fields by combining the conventional robust estimation with a modified, genetic algorithm. The baseline model used in the development is a linear optic flow motion algorithm [38] due to its computational simplicity, The statistical properties of the generalized linear regression (GLR) model are thoroughly explored and the sensitivity of the motion estimates toward data noise is quantitatively established. Conventional robust estimators are then incorporated into the linear regression model to suppress a small percentage of gross data errors or outliers. However, segmenting an optic flow field consisting of a large portion of incorrect data or multiple motion groups requires a very high robustness that is unattainable by the conventional robust estimators, To solve this problem, we propose a genetic partitioning algorithm that elegantly combines the robust estimation with the genetic algorithm by a bridging genetic operator called self-adaptation. C1 NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. UNIV MISSOURI,DEPT ELECT & COMP ENGN,COLUMBIA,MO 65211. UNIV MISSOURI,DEPT STAT,COLUMBIA,MO 65211. RP HUANG, Y (reprint author), AT&T BELL LABS,MIDDLETOWN,NJ 07748, USA. RI Palaniappan, Kannappan/A-3231-2008 NR 41 TC 41 Z9 43 U1 0 U2 3 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0162-8828 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD DEC PY 1995 VL 17 IS 12 BP 1177 EP 1190 DI 10.1109/34.476510 PG 14 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA TJ275 UT WOS:A1995TJ27500005 ER PT J AU Iguchi, T Atlas, D Okamoto, K Sumi, A AF Iguchi, T Atlas, D Okamoto, K Sumi, A TI Footprints of storms on the sea in the JERS-1 SAR image SO IEICE TRANSACTIONS ON COMMUNICATIONS LA English DT Article DE measurement and metrology; electronic and radio applications ID RADAR SCATTERING; RAIN; WAVES AB SEASAT synthetic aperture radar (SAR) echoes from the sea show beautiful images of storms over the ocean. However, the mechanisms by which such storm images are created have not yet been revealed very well. The core of these images is usually an echo-free hole which is attributed to the damping of the radar-detectable short gravity waves by the intense rain in the storm core. The bright area surrounding the core is believed to be caused by strong winds diverging from the downdraft which is collocated with the intense rain. The outer boundary of the bright area has been found to be associated with the classical gust front. During the Tropical Ocean Global Atmosphere/Coupled Ocean-Atmosphere Response Experiment (TOGA/COARE), continuous observations of rain by shipborne radars were carried out. One image of JERS-1 SAR taken in this period contains storms that were within the observation area of a shipborne radar. The SAR image and the rain-radar image are compared. Even though the signal-to-noise ratio of the SAR image is very low, there is good correspondence between heavy rain areas and some of the dark areas in the SAR image. The boundary of a rain-induced dark area is found to correspond approximately to the radar reflectivity factor (Z-factor) of 35 dBZ or 5.5 mm/h of rain. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. UNIV TOKYO, CTR CLIMATE SYST RES, TOKYO 153, JAPAN. RP Iguchi, T (reprint author), COMMUN RES LABS, KOGANEI, TOKYO 184, JAPAN. NR 13 TC 3 Z9 3 U1 0 U2 0 PU IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG PI TOKYO PA KIKAI-SHINKO-KAIKAN BLDG, 3-5-8, SHIBA-KOEN, MINATO-KU, TOKYO, 105-0011, JAPAN SN 0916-8516 EI 1745-1345 J9 IEICE T COMMUN JI IEICE Trans. Commun. PD DEC PY 1995 VL E78B IS 12 BP 1580 EP 1584 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA TM345 UT WOS:A1995TM34500004 ER PT J AU Sun, XH Joslin, RD AF Sun, XH Joslin, RD TI A parallel prefix algorithm for almost Toeplitz tridiagonal systems SO INTERNATIONAL JOURNAL OF HIGH SPEED COMPUTING LA English DT Article DE high performance computing; parallel numerical algorithm; tridiagonal system; Toeplitz tridiagonal system; compact finite-difference scheme ID FINITE-DIFFERENCE SCHEMES; EQUATIONS; SOLVERS AB highly accurate solutions. However, the resulting systems from compact schemes are tridiagonal systems that are difficult to solve efficiently on parallel computers. Considering the almost symmetric Toeplitz; structure, a parallel algorithm, simple parallel prefix (SPP), is proposed. The SPP algorithm requires less memory than the conventional LU decomposition and is efficient on parallel machines. It consists of a prefix communication pattern and AXPY operations. Both the computation and the communication can be truncated without degrading the accuracy when the system is diagonally dominant. A formal accuracy study has been conducted to provide a simple truncation formula. Experimental results have been measured on a MasPar MP-1 SIMD machine and on a Gray 2 vector machine. Experimental results show that the simple parallel prefix algorithm is a good algorithm for symmetric, almost symmetric Toeplitz tridiagonal systems and for the compact scheme on high-performance computers. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. RP Sun, XH (reprint author), LOUISIANA STATE UNIV,DEPT COMP SCI,BATON ROUGE,LA 70803, USA. NR 27 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0129-0533 J9 INT J HIGH SPEED COM JI Int. J. High Speed Comput. PD DEC PY 1995 VL 7 IS 4 BP 547 EP 576 DI 10.1142/S0129053395000300 PG 30 WC Computer Science, Theory & Methods SC Computer Science GA TN573 UT WOS:A1995TN57300005 ER PT J AU Blass, WE Mahan, SL Chin, G AF Blass, WE Mahan, SL Chin, G TI Convolution connection paradigm neural network enables linear system theory-based image enhancement SO INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY LA English DT Article AB A new type of robust numeric solution of one form of the Fredholm integral equations of the first kind has been discovered. This discovery has its most immediate and important applications in the deconvolution or deblurring of data acquired using scientific instruments. A solution of this integral equation has very general applications. For example, investigator-controlled mapping of the instrumental point-spread function to a more useful form is made feasible. The solution of the linear systems imaging model integral equation results from operations performed on the instrumental kernel, response, or point-spread function with the direct result being the production of a robust, effective inverse kernel. The effective inverse is robust even in the presence of noise. The generation of tile inverse kernel in no way depends on the observational data. Therefore, the image enhancement produced by this method contrasts with other numeric schemes that operate only on the observed data. This is an important distinction. This technique, which uses simple numeric operations, offers the possibility of attaining real-time data enhancements for observational instruments. The concept of taking control of the instrument kernel or point-spread function forms the basis of the work presented. Investigations of the application of artificial neural networks to resolution enhancement of Hubble Space Telescope imagery have led to a novel extended instrument paradigm that permits reliable and robust resolution enhancement. In addition to resolution enhancement, the fruits of this investigation have provided a powerful data mapping tool that permits nontrivial, numeric apodization of observed data. The applications of the novel convolution connection paradigm neural network has a great potential for multidisciplinary applications such as resolution enhancement of image and spectral data. (C) 1995 John Wiley & Sons, Inc. C1 NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. RP Blass, WE (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. RI Blass, William/A-2792-2008; Chin, Gordon/E-1520-2012 NR 20 TC 4 Z9 4 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0899-9457 J9 INT J IMAG SYST TECH JI Int. J. Imaging Syst. Technol. PD WIN PY 1995 VL 6 IS 4 BP 350 EP 357 DI 10.1002/ima.1850060408 PG 8 WC Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA TM157 UT WOS:A1995TM15700007 ER PT J AU KOOI, JW CHAN, M BUMBLE, B LEDUC, HG SCHAFFER, P PHILLIPS, TG AF KOOI, JW CHAN, M BUMBLE, B LEDUC, HG SCHAFFER, P PHILLIPS, TG TI 230 AND 492 GHZ LOW-NOISE SIS WAVE-GUIDE RECEIVERS EMPLOYING TUNED NB/ALOX/NB TUNNEL-JUNCTIONS SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article ID MODEL MEASUREMENTS; MIXER; PERFORMANCE; GAIN AB We report results on two full height waveguide receivers that cover the 200-290 GHz and 380-510 GHz atmospheric windows. The receivers are part of the facility instrumentation at the Caltech Submillimeter Observatory on Mauna Kea in Hawaii. We have measured receiver noise temperatures in the range of 20K-35K DSB in the 200-290 GHz band, and 65-90K DSB in the 390-510 GHz atmospheric band. In both instances low mixer noise temperatures and very high quantum efficiency have been achieved. Conversion gain (3 dB) is possible with the 230 GHz receiver, however lowest noise and most stable operation is achieved with unity conversion gain. A 40% operating bandwidth is achieved by using a RF compensated junction mounted in a two-tuner full height waveguide mixer block. The tuned Nb/AlOx/Nb tunnel junctions incorporate an ''end-loaded'' tuning stub with two quarter-wave transformer sections to tune out the large junction capacitance. Both 230 and 492 GHz SIS junctions are 0.49 mu m(2) in size and have current densities of 8 and 10 kA/cm(2) respectively. Fourier Transform Spectrometer (FTS) measurements of the 230 and 492 GHz tuned junctions show good agreement with the measured heterodyne waveguide response. C1 JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA. RP KOOI, JW (reprint author), CALTECH,DIV PHYS MATH & ASTRON,SUBMILLIMETER OBSERV,PASADENA,CA 91125, USA. NR 34 TC 21 Z9 21 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD DEC PY 1995 VL 16 IS 12 BP 2049 EP 2068 DI 10.1007/BF02073409 PG 20 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA TK350 UT WOS:A1995TK35000001 ER PT J AU Chauhan, NS AF Chauhan, NS TI Microwave inversion of root mean square height from vegetated fields: A dual frequency technique SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID ELECTROMAGNETIC BACKSCATTERING; SCATTERING; SOIL; DISKS AB An iterative, physically model based inversion algorithm has been used to estimate root mean square (r.m.s.) surface roughness height from radar data, collected over vegetated areas. The model is based on a discrete scatterer random media technique, and employs the distorted Born approximation to model the backscatter coefficients for a given scene. In the model, the Fresnel reflectivity (a measure of soil moisture) and surface roughness appear together in the vegetation-ground interaction term. An approach is followed that utilizes differences in their frequency response to separate the two. Sensitivity analysis shows that the change in surface reflectivity owing to the change in frequency from the L- to C-band is dominated by surface r.m.s. height. The Fresnel reflectivity stays almost constant over this frequency interval. The inversion algorithm based on these sensitivity differences is applied to the backscatter model data from a plant canopy of soybean. Calculations show that the technique gives accurate results from a model backscatter data set that is corrupted with random noise. The inversion algorithm is also applied to Synthetic Aperture Radar (SAR) data collected over corn fields during the MACHYDRO'90 experiment in Pennsylvania, USA, There is an excellent agreement between the measured and the estimated r.m.s. surface height. RP Chauhan, NS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GWU,HYDROL SCI BRANCH,GREENBELT,MD 20771, USA. NR 23 TC 2 Z9 2 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD DEC PY 1995 VL 16 IS 18 BP 3555 EP 3567 PG 13 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA TK879 UT WOS:A1995TK87900004 ER PT J AU Rao, KS Rao, YS Wang, JR AF Rao, KS Rao, YS Wang, JR TI Frequency dependence of polarization phase difference SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID SURFACE-ROUGHNESS; SOIL-MOISTURE; VEGETATION AB Polarimetric AIRSAR data of 13 July 1990 acquired over Mahantango watershed area were processed for the identification of cornfields and forested areas. Polarization Phase Difference (PPD) values were computed for the cornfields at P-, L- and C- bands and studied as a function of frequency. The results compare well with the model calculations at 24 degrees incidence angle, whereas the locations of cornfields were computed to be at 35 degrees incidence angle. The discrepancy is attributed to a lack of accurate ground truth and the undulating topography of the cornfields. Another study reported here deals with the usefulness of the Polarization Index (PI) for the study of vegetation. PI was found to be dependent on the frequency for the cornfields, whereas for forest trees no such dependence was noticed. PIHH,HV is a more useful parameter than PIHH,VV even for the study of cornfields. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Rao, KS (reprint author), INDIAN INST TECHNOL,CSRE,BOMBAY 400076,MAHARASHTRA,INDIA. NR 19 TC 3 Z9 4 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD DEC PY 1995 VL 16 IS 18 BP 3605 EP 3617 PG 13 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA TK879 UT WOS:A1995TK87900008 ER PT J AU VOLPE, R KHOSLA, P AF VOLPE, R KHOSLA, P TI THE EQUIVALENCE OF 2ND-ORDER IMPEDANCE CONTROL AND PROPORTIONAL GAIN EXPLICIT FORCE CONTROL SO INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH LA English DT Article ID MANIPULATORS AB This article discusses the essential equivalence of second-order impedance control with force feedback and proportional gain explicit force control with force feedforward. This is first done analytically by reviewing each control method and showing how they mathematically correspond for constrained manipulator control. For stiff environments the correspondence is exact. However even for softer environments, a similar response of the system is indicated. Next, the results of an implementation of these control schemes on the CMU DD Am II are presented, confirming the predictions of the analysis. These results experimentally demonstrate that proportional gain force control and impedance control, with and without dynamics compensation, have equivalent response to commanded force trajectories. C1 CARNEGIE MELLON UNIV,INST ROBOT,DEPT ELECT & COMP ENGN,PITTSBURGH,PA 15213. RP VOLPE, R (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 29 TC 9 Z9 10 U1 0 U2 2 PU MIT PRESS PI CAMBRIDGE PA 55 HAYWARD ST JOURNALS DEPT, CAMBRIDGE, MA 02142 SN 0278-3649 J9 INT J ROBOT RES JI Int. J. Robot Res. PD DEC PY 1995 VL 14 IS 6 BP 574 EP 589 DI 10.1177/027836499501400604 PG 16 WC Robotics SC Robotics GA TH943 UT WOS:A1995TH94300004 ER PT J AU Taylor, PT Ravat, D AF Taylor, PT Ravat, D TI An interpretation of the Magsat anomalies of central Europe SO JOURNAL OF APPLIED GEOPHYSICS LA English DT Article ID GRAVITY; POLAND; MODEL; ZONE AB Magsat studies of central Europe have revealed correspondence between tectonic elements/geological structures and long-wavelength satellite-altitude anomalies. The most striking correlation is the two Magsat anomalies (one positive and the other negative) associated with either side of the Tornquist-Teisseyre Zone (TTZ). The TTZ, which extends from the Black Sea to the Baltic Sea, represents the structural boundary (suture) between the younger, thinner, and hotter crust of the Hercynide or Paleozoic block (negative anomaly) and the older, thicker, and colder crust of the East European Precambrian Platform (positive anomaly). This produces a gradient of approximately 18 nT (peak-to-trough) and a half-wavelength of 720 km along a Magsat orbit at 325 km altitude. This anomaly pair is the result of the juxtaposition of these two significantly different crustal blocks. To model this field, two irregular three-dimensional bodies were used to represent the Precambrian and Paleozoic crust. The former was modeled with a normal magnetization vector while the latter was modeled with a reverse vector. Aeromagnetic anomalies in western Germany and rock magnetic measurements from Germany and Scandinavia support a model in which reversely magnetic geologic units, extending from upper-crustal metasediments to mid-crustal sources produce this negative anomaly. C1 SO ILLINOIS UNIV,DEPT GEOL,CARBONDALE,IL 62901. RP Taylor, PT (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,GREENBELT,MD 20771, USA. RI Taylor, Patrick/D-4707-2012; OI Taylor, Patrick/0000-0002-1212-9384; Ravat, Dhananjay/0000-0003-1962-4422 NR 37 TC 17 Z9 17 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-9851 J9 J APPL GEOPHYS JI J. Appl. Geophys. PD DEC PY 1995 VL 34 IS 2 BP 83 EP 91 DI 10.1016/0926-9851(95)00015-1 PG 9 WC Geosciences, Multidisciplinary; Mining & Mineral Processing SC Geology; Mining & Mineral Processing GA TM778 UT WOS:A1995TM77800001 ER PT J AU RODGERS, EB PIERCE, HF AF RODGERS, EB PIERCE, HF TI A SATELLITE OBSERVATIONAL STUDY OF PRECIPITATION CHARACTERISTICS IN WESTERN NORTH PACIFIC TROPICAL CYCLONES SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID NUMERICAL-SIMULATION; DIURNAL-VARIATION; MODEL; INTENSIFICATION; INTENSITY; EVOLUTION; HEAT AB Special Sensor Microwave/Imager(SSM/I) observations were used to examine spatial and temporal changes in the precipitation characteristics for western North Pacific tropical cyclones that reached storm stage or greater during 1987-92. The second version of the Goddard scattering algorithm, that employed the 85-GHz brightness temperatures to measure rain rate, provided an analysis of the tropical cyclone precipitation distribution in greater detail, while the numerous SSM/I observations helped to better define the relationship between the tropical cyclones' spatial and temporal distribution of precipitation and the systems intensity, intensity change, radiational forcing, and mean monthly sea surface temperatures (SSTs). The two SSM/Is flown since 1992 also helped to provide a more detailed analysis of the evolution of the tropical cyclone inner-core diabatic heating. Similar to the SSM/I-observed 1987-89 western North Atlantic tropical cyclones, the SSM/I observations of the western North Pacific tropical cyclones revealed that the more intense systems had higher rain rates and greater areal distribution of rain. In addition, the heaviest rain rates were found nearer to the center of all the tropical cyclones. However, western North Pacific typhoons were found to have heavier azimuthally averaged rain rates and a greater contribution from the heavier rain within the inner core (i.e., within ill km of the center) than the western North Atlantic hurricanes. The SSM/I observations of the western North Pacific tropical cyclones also suggested the following: 1) there appears to be a diurnal variation in the tropical cyclone precipitation (i.e., morning maximum and an evening minimum) except in the inner-core regions of systems that are at storm stage and greater; 2) the maximum rain rate that a tropical cyclone can produce in the inner-core region is dictated by SSTs with maximum rain rates occurring at SSTs greater than 29 degrees C; 3) the large changes in the tropical cyclone inner-core rain rate (latent heat release) help to initiate and maintain periods of tropical cyclone intensification; and 4) the intensity of these tropical cyclones become more responsive to rain-rate changes as the tropical cyclones become more intense. C1 SCI SYST & APPLICAT INC,LANHAM,MD. RP RODGERS, EB (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,MESOSCALE DYNAM & PRECIPITAT BRANCH,CODE 912,GREENBELT,MD 20771, USA. NR 45 TC 18 Z9 22 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD DEC PY 1995 VL 34 IS 12 BP 2587 EP 2599 DI 10.1175/1520-0450(1995)034<2587:ASOSOP>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TJ417 UT WOS:A1995TJ41700002 ER PT J AU HADDAD, ZS IM, E DURDEN, SL AF HADDAD, ZS IM, E DURDEN, SL TI INTRINSIC AMBIGUITIES IN THE RETRIEVAL OF RAIN RATES FROM RADAR RETURNS AT ATTENUATING WAVELENGTHS SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID PATH-INTEGRATED ATTENUATION; DUAL-FREQUENCY RADAR; ALGORITHM AB It is well known that there are significant deterministic ambiguities inherent in trying to determine the particular rain-rate profile that produced some given sequence of air- or spaceborne radar echo powers at a single attenuating frequency. For different combinations of radar data, formulas for the mutually ambiguous solutions are derived and the resulting ambiguities are quantified mathematically. When the given data consist of a single radiometer measurement together with a single-frequency set of range-gated echo powers, it is shown that several substantially different rain profiles can still realistically be considered solutions. On the other hand, if the data consist of a two-frequency set of echo powers, it is proven that the inversion problem generically has a unique solution. RP HADDAD, ZS (reprint author), CALTECH,JET PROP LAB,300-227,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 16 TC 16 Z9 16 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD DEC PY 1995 VL 34 IS 12 BP 2667 EP 2679 DI 10.1175/1520-0450(1995)034<2667:IAITRO>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TJ417 UT WOS:A1995TJ41700008 ER PT J AU HADDAD, ZS JAMESON, AR IM, E DURDEN, SL AF HADDAD, ZS JAMESON, AR IM, E DURDEN, SL TI IMPROVED COUPLED Z-R AND K-R RELATIONS AND THE RESULTING AMBIGUITIES IN THE DETERMINATION OF THE VERTICAL-DISTRIBUTION OF RAIN FROM THE RADAR BACKSCATTER AND THE INTEGRATED ATTENUATION SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB Several algorithms to calculate a rain-rate profile from a single-frequency air- or spaceborne radar backscatter profile and a given path-integrated attenuation have been proposed. The accuracy of any such algorithm is limited by the ambiguities between the (multiple) exact solutions, which depend on the variability of the parameters in the Z-R and k-R relations used. In this study, coupled Z-R and k-R relations are derived based on the drop size distribution. It is then shown that, because of the coupling, the relative difference between the multiple mutually ambiguous rain-rate profiles solving the problem must remain acceptably low, provided the available path-integrated attenuation value is known to within 0.5 dB. C1 APPL RES CORP,LANDOVER,MD 20785. CALTECH,JET PROP LAB,PASADENA,CA. RP HADDAD, ZS (reprint author), CALTECH,JET PROP LAB,300-227,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 11 TC 4 Z9 4 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD DEC PY 1995 VL 34 IS 12 BP 2680 EP 2688 DI 10.1175/1520-0450(1995)034<2680:ICARAT>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TJ417 UT WOS:A1995TJ41700009 ER PT J AU MENA, RA SCHACHAM, SE HAUGLAND, EJ ALTEROVITZ, SA YOUNG, PG BIBYK, SB RINGEL, SA AF MENA, RA SCHACHAM, SE HAUGLAND, EJ ALTEROVITZ, SA YOUNG, PG BIBYK, SB RINGEL, SA TI CHARACTERIZATION OF THE TRANSPORT-PROPERTIES OF CHANNEL DELTA-DOPED STRUCTURES BY LIGHT-MODULATED SHUBNIKOV-DE HAAS MEASUREMENTS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID 2-DIMENSIONAL ELECTRON-GAS; DEHAAS OSCILLATIONS; SCATTERING TIME; GAAS; HETEROSTRUCTURES; HETEROJUNCTIONS; ENHANCEMENT; MOBILITIES AB The transport properties of channel delta-doped quantum-well structures were characterized by conventional Hall effect and light-modulated Shubnikov-de Haas (SdH) effect measurements. The large number of carriers that become available due to the delta doping of the channel, leads to an apparent degeneracy in the well. As a result of this degeneracy, the carrier mobility remains constant as a function of temperature from 300 down to 1.4 K. The large amount of impurity scattering, associated with the overlap of the charge carriers and the dopants, resulted in low carrier mobilities and restricted the observation of the oscillatory magnetoresistance used to characterize the two-dimensional electron gas by conventional SdH measurements. By light modulating the carriers, we were able to observe the SdH oscillation at low magnetic fields, below 1.4 T, and derive a value for the quantum scattering time. Our results for the ratio of the transport and quantum scattering times are lower than those previously measured for similar structures using much higher magnetic fields. (C) 1995 American Institute of Physics. C1 OHIO STATE UNIV, DEPT ELECT ENGN, COLUMBUS, OH 43210 USA. RP NASA, LEWIS RES CTR, CLEVELAND, OH 44135 USA. NR 31 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 1995 VL 78 IS 11 BP 6626 EP 6632 DI 10.1063/1.360484 PG 7 WC Physics, Applied SC Physics GA TH851 UT WOS:A1995TH85100039 ER PT J AU KYLE, HL HUCEK, R ARDANUY, P PENN, L HICKEY, J GROVEMAN, B AF KYLE, HL HUCEK, R ARDANUY, P PENN, L HICKEY, J GROVEMAN, B TI IN-FLIGHT CALIBRATION OF THE NIMBUS-7 EARTH RADIATION BUDGET (ERB) SENSORS .1. A THERMAL-MODEL FOR THE SHORTWAVE CHANNELS SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SOLAR TOTAL IRRADIANCE; WIDE FIELD; EL-NINO AB Much of the early record of spectrally broadband earth radiation budget (ERB) measurements was taken by the ERB instrument launched on the Nimbus-7 spacecraft in October 1978. The wide-field-of-view (WFOV) sensors measured the emitted and reflected radiation from November 1978 through January 1993, and the first nine years have been processed into a stable, long-term dataset. However, heating and cooling of the ERB experiment introduced thermal perturbations in the original measurements that were only significant in the shortwave (SW) channels. These sensors were covered by spherical filter domes to absorb incident longwave (LW) radiation. In this paper, a thermal regression model-the thermal calibration adjustment table (CAT)-is developed to track and remove these thermal signals from the SW data. The model relies on instrument temperatures within and near the surface of the ERB instrument, and the observed nonzero nighttime sensor readings represent the thermal signals. Confidence that the model is stable for daytime applications was gained by smoothing the solution using ridge regression and noting the effect on the solution coefficient vector. The bias signal produced by the thermal CAT portrays the balance of instrument heating and cooling within the Nimbus-7 variable external radiation environment. Cooling occurs over about two-thirds of an orbit including satellite night. During the nighttime, the sensor bias change is about 17 W m(-2) (compare with mean daytime SW flux of about 200 W m(-2)) with little seasonal or annual fluctuation. Strong warming takes place during morning and evening twilight when direct solar radiation illuminates the WFOV sensors. This warming effectively compensates for nighttime cooling when the opposite thermal signature is found. Additional daytime warming occurs for satellite positions near the solar declination when the effects of combined LW and SW terrestrial fluxes exceed thermal cooling to space. However, this heating is influenced by the terrestrial scene and so it varies seasonally. The thermal CAT was one of two semi-independent procedures, each of equal mean accuracy, developed to validate and correct for thermally induced sensor signals. The other, called the global CAT, is described in the second paper in this series. Although the thermal CAT was considered heuristically superior, the global CAT was chosen for the basic calibration work since it was thought to be potentially more stable for the production of a consistent long-term ERB dataset. C1 RES & DATA SYST CORP,GREENBELT,MD. EPPLEY LAB INC,NEWPORT,RI. RP KYLE, HL (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 9023,GREENBELT,MD 20771, USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD DEC PY 1995 VL 12 IS 6 BP 1137 EP 1149 DI 10.1175/1520-0426(1995)012<1137:IFCOTE>2.0.CO;2 PG 13 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA TE756 UT WOS:A1995TE75600001 ER PT J AU KYLE, HL HUCEK, R ARDANUY, P PENN, L GROVEMAN, B HICKEY, J MASCHOFF, R AF KYLE, HL HUCEK, R ARDANUY, P PENN, L GROVEMAN, B HICKEY, J MASCHOFF, R TI IN-FLIGHT CALIBRATION OF THE NIMBUS-7 EARTH RADIATION BUDGET (ERB) SENSORS .2. SHORT-TERM PERTURBATIONS SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB This paper describes the production calibration adjustment algorithms used to remove thermal perturbation and stray light noise signals from the Nimbus-7 earth radiation budget (ERB) measurements. Sunlight, both direct and scattered from the sensor baffles, contaminated the ERB measurements at satellite sunrise and sunset. The problem covered subsatellite solar zenith angles from 90 degrees to 120 degrees and reduced the usefulness of the longwave spectral radiation measurements. Scattered light corrections are made from 90 degrees to 99 degrees while orbit-by-orbit interpolation is used from 99 degrees to 121 degrees. Tests indicate that in the mean the midpoint interpolation error is less than 1 W m(-2) with a standard deviation of about 5 W m(-2). Thermal perturbations on the total channel 12 (0.2-50 mu m) appeared to be always less than 0.3%. However, the Suprasil-W domes on the otherwise similar shortwave channels 13 and 14 in some way helped produce thermal perturbations of up to 6% or more in channel 13 (0.2-3.8 mu m) and up to 3% or more in channel 14 (0.7-2.8 mu m). These perturbations arose from variations in external radiant heating during the day, night, sunrise, and sunset. In addition, the on/off cycles of the ERB and neighboring experiments produced day-to-day variations. The algorithms described here helped produce a stable 9-year-long measurement set. No thermal corrections were made in channel 12 and the obvious thermal perturbations in channels 13 and 14 were corrected, The absolute accuracy of the calibrated measurements is difficult to determine. The remaining uncertainty depends on the perturbing functions that were greater at high latitudes, near satellite sunrise and sunset, than in the Tropics. In June and July, the corrections for the daytime thermal perturbations near the North Pole may be too large by 3-5 W m(-2). In general, the Nimbus-7 ERB products show good agreement with the follow-on Earth Radiation Budget Experiment (ERBE) products. C1 RES & DATA SYST CORP,GREENBELT,MD. EPPLEY LAB INC,NEWPORT,RI. GULTON IND INC,ALBUQUERQUE,NM. RP KYLE, HL (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 9023,GREENBELT,MD 20771, USA. NR 11 TC 6 Z9 6 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD DEC PY 1995 VL 12 IS 6 BP 1150 EP 1162 DI 10.1175/1520-0426(1995)012<1150:IFCOTE>2.0.CO;2 PG 13 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA TE756 UT WOS:A1995TE75600002 ER PT J AU KYLE, HL HUCEK, R ARDANUY, P PENN, L GROVEMAN, B AF KYLE, HL HUCEK, R ARDANUY, P PENN, L GROVEMAN, B TI IN-FLIGHT CALIBRATION OF THE NIMBUS-7 EARTH RADIATION BUDGET(ERB) SENSORS .3. LONG-TERM CHANGES SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ERB EXPERIMENT; WIDE-FIELD; IRRADIANCE AB Sensitivity changes in the four wide-field-of-view (WFOV) Nimbus-7 earth radiation budget (ERB) sensors were monitored over a 9-yr period (November 1978-0ctober 1987) by use of a number of reference sources. The sun was the primary reference and was used to check the shortwave (SW; about 0.2-4 mu m) sensitivities on the twin total channels 11 and 12. The longwave (LW; greater than 4 mu m) sensitivity in channel 12 was checked by a time series analysis of the nighttime mean global terrestrial signal, but the method could not be usefully applied to channel 11 because it was shuttered too much of the time. The accuracy of this type of analysis was verified by comparing a similar shortwave time series analysis with the solar calibration results. It was also checked by comparing channel 12 nighttime measurements with those from the companion scanner. The scanner had a built-in blackbody for calibration, but the scanner failed after 20 months. As a result of this comparison, a bias adjustment of 12.6 W m(-2) was made in the channel 12 measurements. In addition, channels 11 and 12 were compared to each other. The shortwave channels 13 (0.2-4 mu m) and 14 (0.7-2.8 mu m) were covered by Suprasil-W domes that blocked radiation greater than 4 mu m. A piece of red glass in channel 14 further restricted its spectral range to the near infrared. After launch, these domes fogged asymmetrically. For this reason, the effective sensitivity changes in these channels were monitored by comparison with channel 12 using the whole earth as a transfer target. The shortwave range mentioned above for channels 11 and 12 really refers to channel 13 and not to channels 11 and 12. By October 1987, the following sensitivity decreases had occurred: channel 11 (no observable change), channel 12 (LW 2.5%, SW 1.5%), channel 13 (13.3%), and channel 14 (6%). Corrections for these changes kept the calibrated signals stable to better than 0.5% over the 9-yr period. Year-to-year annual global mean longwave shifts of 0.1%-0.4% have been related to climate perturbations and appear real. C1 RES & DATA SYST CORP,GREENBELT,MD. RP KYLE, HL (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 9023,GREENBELT,MD 20771, USA. NR 27 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD DEC PY 1995 VL 12 IS 6 BP 1163 EP 1176 DI 10.1175/1520-0426(1995)012<1163:IFCOTE>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA TE756 UT WOS:A1995TE75600003 ER PT J AU FERRARE, RA MELFI, SH WHITEMAN, DN EVANS, KD SCHMIDLIN, FJ STARR, DO AF FERRARE, RA MELFI, SH WHITEMAN, DN EVANS, KD SCHMIDLIN, FJ STARR, DO TI A COMPARISON OF WATER-VAPOR MEASUREMENTS MADE BY RAMAN LIDAR AND RADIOSONDES SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SPECTRAL RESOLUTION LIDAR; STRATOSPHERIC AEROSOL; MOISTURE MEASUREMENTS; EXTINCTION; CLIMATE; CLOUDS; SYSTEM; OZONE AB This paper examines the calibration characteristics of the NASA/GSFC Raman water vapor lidar during three field experiments that occurred between 1991 and 1993. The lidar water vapor profiles are calibrated using relative humidity profiles measured by AIR and Vaisala radiosondes. The lidar calibration computed using the AIR radiosonde, which uses a carbon hygristor to measure relative humidity, was 3%-5% higher than that computed using the Vaisala radiosonde, which uses a thin film capacitive element These systematic differences were obtained for relative humidities above 30% and so cannot be explained by the known poor low relative humidity measurements associated with the carbon hygristor. The lidar calibration coefficient was found to vary by less than 1% over this period when determined using the Vaisala humidity data and by less than 5% when using the AIR humidity data. The differences between the lidar relative humidity profiles and those measured by these radiosondes are also examined. These lidar-radiosonde comparisons are used in combination with a numerical model of the lidar system to assess the altitude range of the GSFC lidar. The model results as well as the radiosonde comparisons indicate that for a lidar located at sea level measuring a typical midlatitude; water vapor profile, the absolute error in relative humidity for a 10-min, 75-m resolution profile is less than 10% for altitudes below 8.5 km. Model results show that this maximum altitude can be extended to 10 km by increasing the averaging time and/or reducing the range resolution. RP FERRARE, RA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 912,GREENBELT,MD 20771, USA. NR 54 TC 73 Z9 76 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD DEC PY 1995 VL 12 IS 6 BP 1177 EP 1195 DI 10.1175/1520-0426(1995)012<1177:ACOWVM>2.0.CO;2 PG 19 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA TE756 UT WOS:A1995TE75600004 ER PT J AU DUARTE, D LEWIS, A HOFFMAN, EJ CROSSMAN, D AF DUARTE, D LEWIS, A HOFFMAN, EJ CROSSMAN, D TI A CAREER-DEVELOPMENT MODEL FOR PROJECT-MANAGEMENT WORKFORCES SO JOURNAL OF CAREER DEVELOPMENT LA English DT Article C1 NASA,WASHINGTON,DC 20546. NR 28 TC 1 Z9 1 U1 1 U2 1 PU HUMAN SCI PRESS INC PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 SN 0894-8453 J9 J CAREER DEV JI J. Career Dev. PD WIN PY 1995 VL 22 IS 2 BP 149 EP 164 PG 16 WC Psychology, Applied SC Psychology GA TA838 UT WOS:A1995TA83800009 ER PT J AU Yamanouchi, T Charlock, TP AF Yamanouchi, T Charlock, TP TI Comparison of radiation budget at the TOA and surface in the Antarctic from ERBE and ground surface measurements SO JOURNAL OF CLIMATE LA English DT Article AB Radiative fluxes at the top of the atmosphere (TOA) and the surface were compared at two Antarctic stations, Syowa and the South Pole, using Earth Radiation Budget Experiment (ERBE) data and surface observations. Fluxes at both sites were plotted against cloud amounts derived from surface synoptic observations. Throughout the year over the snow- and ice-covered Antarctic, cloud radiation was found to heat the surface and cool the atmosphere; cloud longwave (LW) effects were greater than cloud shortwave (SW) effects. Clouds have a negligible effect on the absorption of SW by the atmosphere in the interior and clouds slightly increase the absorption of SW by the atmosphere along the coast. At the TOA, the LW cloud effect was heating along the coast in summer and winter, heating in the interior during summer, and slight cooling in the interior during winter. This unique TOA cloud LW cooling was due to the extremely low surface temperature in the interior during winter. At the TOA, clouds induced SW cooling in the interior and along the coast; sorting of pixel-scale ERBE data and surface cloud observations was needed to demonstrate this. The monthly averaged fluxes at the surface and TOA were compared, and the net radiative fluxes for the atmospheric column were estimated. The atmospheric column loses net radiant energy throughout the year with an asymmetrical seasonal variation. The loss of net radiant energy by the atmosphere is much larger than the loss by the surface. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP Yamanouchi, T (reprint author), NATL INST POLAR RES,ITABASHI KU,9-10 KAGA,1 CHOME,TOKYO 173,JAPAN. RI Yamanouchi, Takashi/P-2041-2015 NR 24 TC 10 Z9 10 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD DEC PY 1995 VL 8 IS 12 BP 3109 EP 3120 DI 10.1175/1520-0442(1995)008<3109:CORBAT>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TN511 UT WOS:A1995TN51100015 ER PT J AU Schraeder, PL Lathers, CM AF Schraeder, PL Lathers, CM TI Clinical pharmacology of antiepileptic drug use: ''Clinical pearls about the perils of Patty'' SO JOURNAL OF CLINICAL PHARMACOLOGY LA English DT Article ID INDUCED TERATOGENESIS AB This Clinical Pharmacology Problem Solving (CPPS) Unit is for use with fourth- or fifth-year pharmacy students and third- or fourth-year medical students during conferences held when they are taking either a rotation in Neurology or Clinical Pharmacology. It may also be used for house staff teaching of residents in Neurology, Pediatrics, Internal Medicine, and Family Practice and fellows in Clinical Pharmacology. This material was prepared for a Teaching Clinic in Clinical Pharmacology taught by Claire M. Lathers, PhD, FCP, Hugh J. Burford, PhD, FCP, and Cedric M. Smith, MD, FCP, and sponsored by the American College of Clinical Pharmacology, September 19-20, 1992, Washington, DC. This workbook includes: (1) an introduction to the Clinical Pharmacology Problem Solving (CPPS) Unit; (2) the learning objectives of the clinical simulation; (3) a pretest; (4) four clinical episodes occurring over many years in the life of a patient; (5) answers to the pretest; (6) a posttest; (7) answers to the posttest. C1 UNIV MED & DENT NEW JERSEY,ROBERT WOOD JOHNSON MED SCH,DIV NEUROL,CAMDEN,NJ 08103. US FDA,CARDIO RENAL DIV,ROCKVILLE,MD 20857. NASA,SPACE BIOMED RES INST,CARDIOVASC LAB,HOUSTON,TX 77058. UNIFORMED SERV UNIV HLTH SCI,DEPT PHARMACOL,BETHESDA,MD 20814. NR 9 TC 6 Z9 6 U1 0 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0091-2700 J9 J CLIN PHARMACOL JI J. Clin. Pharmacol. PD DEC PY 1995 VL 35 IS 12 BP 1120 EP 1135 PG 16 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA TN805 UT WOS:A1995TN80500002 PM 8750362 ER PT J AU JACKSON, FC JENSEN, RE AF JACKSON, FC JENSEN, RE TI WAVE-FIELD RESPONSE TO FRONTAL PASSAGES DURING SWADE SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE COLD FRONT; RADAR; FETCH; SEA STATE; WIND WAVES; DATA BUOY ID OCEAN WAVES; RADAR; DIRECTION; SPECTRUM; WINDS AB The response of a wave field to turning winds following the passage of two cold fronts off the U. S. East Coast around St. Valentine's Day, 1991 is studied using data collected as a part of the Surface WAve Dynamics Experiment (SWADE). The data include hourly wind and directional wave observations from National Data Buoy Center (NDBC) buoys, wide-area coverage airborne radar estimates of wind speed and directional wave spectra, and wind and surface current analysis fields from numerical models. The data permit the wave field evolution to he tracked over a three day period and over a large area with both fine temporal and spatial resolution. Initially fully developed under similar to 12 m/s southerly winds, the wave field evolves through a state of mixed wind, sea and swell under westerly winds to a final, purely fetch-limited state under similar to 14 m/s northwesterly winds. Analysis of the directional response of the wave field is complicated by a spell of low and variable winds between the two cold fronts. However, by making use of both spatial and temporal data, we arrive at credible estimates of the directional relaxation parameter as a function of frequency. The inferred relaxation rates, although faster than observed by HASSELMANN et al. (1980), are consistent with the numerical results of YOUNG et al. (1987). The observed fetch-limited growth rates agree with those of WALSH et al. (1989). The remotely sensed winds agree well with the in situ data. The radar spectra agree with the buoy data in higher sea states but exhibit poor response in low sea states. C1 USA,CORPS ENGINEERS,COASTAL ENGN RES CTR,WATERWAYS EXPT STN,VICKSBURG,MS 39180. RP JACKSON, FC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HYDROSPHER PROC LAB,GREENBELT,MD 20771, USA. NR 29 TC 3 Z9 3 U1 0 U2 0 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD WIN PY 1995 VL 11 IS 1 BP 34 EP 67 PG 34 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA QG342 UT WOS:A1995QG34200002 ER PT J AU Kaiser, MK Montegut, MJ AF Kaiser, MK Montegut, MJ TI Rotational and translational components of motion parallax: Observers' sensitivity and implications for three-dimensional computer graphics SO JOURNAL OF EXPERIMENTAL PSYCHOLOGY-APPLIED LA English DT Article ID ANGULAR VELOCITY; DEPTH AB The motion of objects during motion parallax can be decomposed into 2 observer-relative components: translation and rotation. The depth ratio of objects in the visual field is specified by the inverse ratio of their angular displacement (from translation) or equivalently by the inverse ratio of their rotations. Despite the equal mathematical status of these 2 information sources, it was predicted that observers would be far more sensitive to the translational than rotational component. Such a differential sensitivity is implicitly assumed by the computer graphics technique billboarding, in which 3-dimensional (3-D) objects are drawn as planar forms (i.e., billboards) maintained normal to the line of sight. In 3 experiments, observers were found to be consistently less sensitive to rotational anomalies. The implications of these findings for kinetic depth effect displays and billboarding techniques are discussed. C1 UNIV VIRGINIA,DEPT PSYCHOL,CHARLOTTESVILLE,VA 22903. RP Kaiser, MK (reprint author), NASA,AMES RES CTR,MAIL STOP 262-2,MOFFETT FIELD,CA 94035, USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU AMER PSYCHOLOGICAL ASSOC PI WASHINGTON PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 SN 1076-898X J9 J EXP PSYCHOL-APPL JI J. Exp. Psychol.-Appl. PD DEC PY 1995 VL 1 IS 4 BP 321 EP 331 PG 11 WC Psychology, Applied SC Psychology GA UQ441 UT WOS:A1995UQ44100004 PM 11540630 ER PT J AU NEUGEBAUER, M GOLDSTEIN, BE MCCOMAS, DJ SUESS, ST BALOGH, A AF NEUGEBAUER, M GOLDSTEIN, BE MCCOMAS, DJ SUESS, ST BALOGH, A TI ULYSSES OBSERVATIONS OF MICROSTREAMS IN THE SOLAR-WIND FROM CORONAL HOLES SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID STREAMS; SPEED AB During its south polar passage in 1994, the Ulysses spacecraft continuously sampled the properties of the solar wind emanating from the south polar coronal hole. At latitudes poleward of similar to-60 degrees, the solar wind speed had an average value of 764 km/s and a range of 700-833 km/s. The principal variations in the vector velocity were associated with either outward propagating Alfven waves with periods up to about half a day or with longer-period high- or low-speed ''microstreams.'' The microstreams had an amplitude of similar to 40 km/s and a mean half width of 0.4 days, and they recurred on timescales of 2-3 days (power spectral peaks at 1.9 and 3.3 days). The density and temperature profiles showed the expected evidence of pileup and compression on the leading edges of high-speed microstreams, although no forward or reverse shocks were observed. The particle fluxes were nearly the same for both the fast and slow microstreams. The higher-speed microstreams had higher proton temperatures and higher alpha-particle abundances than did the slower microstreams. The absence of latitude variations in the thickness or the recurrence rate suggests that the microstreams are caused by temporal rather than long lived (> a few days) spatial variations in the source region at the Sun, Some speculations are made about the possible cause of the microstreams. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, HUNTSVILLE, AL 35812 USA. UNIV LONDON IMPERIAL COLL SCI & TECHNOL, BLACKETT LAB, LONDON, ENGLAND. RP CALTECH, JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91125 USA. NR 24 TC 81 Z9 81 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1995 VL 100 IS A12 BP 23389 EP 23395 DI 10.1029/95JA02723 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH672 UT WOS:A1995TH67200003 ER PT J AU OFMAN, L DAVILA, JM AF OFMAN, L DAVILA, JM TI ALFVEN-WAVE HEATING OF CORONAL HOLES AND THE RELATION TO THE HIGH-SPEED SOLAR-WIND SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOHYDRODYNAMIC SURFACE-WAVES; RESONANT ABSORPTION; ACCELERATION; DISSIPATION; ATMOSPHERE; LEAKY; MODE; FLOW AB Coronal hole regions are well-known sources of high-speed solar wind; however, to account for the observed properties of the solar wind, a source of energy must be included in addition to heat conduction. Alfven waves were suggested as the possible source of heating that accelerates the solar wind. We investigate the heating and propagation of the fast and shear Alfven waves in coronal holes via numerical solution of the time-dependent, linearized, resistive, low-beta, two-dimensional MHD equations in slab geometry. The waves are driven at the lower boundary of the coronal hole and propagate into the corona. We find that fast waves are partially reflected at the coronal hole boundary and significant part of the wave energy leaks out of the coronal hole. We compare the calculated wavelengths and the attenuation rate of the fast waves in the leaky waveguide formed by the coronal hole with the analytical ideal MHD solutions for k(y) = 0, where k(y) is the perpendicular wavenumber, and find an excellent agreement. When k(y) not equal 0 the fast waves couple to the shear Alfven waves and transfer energy across field lines. Resonance heating layers are found to occur when shear Alfven waves are driven and a continuous density profile is assumed for the coronal hole. When resonance absorption is considered, the leakage is small compared to the heating rate. The heating is enhanced by phase mixing when coronal hole inhomogeneities (i.e., plumes) are included. We investigate the dependence of the heating rate on the driver frequency and the Lundquist number S and find a good agreement with the analytical S-1/3 scaling of the dissipation length. We find that when S = 10(4) the low-frequency Alfven waves can be a significant source of heating of coronal holes at several solar radii. At larger values of S, nonlinear effects might reduce the effective dissipation length. We discuss the relation of our results to the observed properties of high-speed solar wind and coronal holes. C1 HUGHES STX CORP,GREENBELT,MD. RP OFMAN, L (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. NR 40 TC 46 Z9 46 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1995 VL 100 IS A12 BP 23413 EP 23425 DI 10.1029/95JA02222 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH672 UT WOS:A1995TH67200005 ER PT J AU OFMAN, L DAVILA, JM AF OFMAN, L DAVILA, JM TI NONLINEAR RESONANT ABSORPTION OF ALFVEN WAVES IN 3 DIMENSIONS, SCALING LAWS, AND CORONAL HEATING SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID KELVIN-HELMHOLTZ INSTABILITY; FIELD LINE RESONANCES; EARTHS MAGNETOSPHERE; SURFACE-WAVES; SOLAR CORONA AB The nonlinear evolution of the resonant absorption of standing and propagating Alfven waves in an inhomogeneous plasma is studied via solution of the time-dependent, three-dimensional, low-beta resistive MHD equations over a wide parameter range, When the nonlinear effects become important, the velocities at the dissipation layer were found to be lower than the linear scaling of S-1/3 would predict, where S is the Lundquist number. Highly sheared velocities that are subject to the Kelvin-Helmholtz-like instability were found at the narrow dissipation layers, Three-dimensional Kelvin-Helmholtz-like vortices appear at and near the dissipation layers and propagate along the slab of plasma when traveling Alfven wave solution are considered. The narrow resonant heating layers are deformed by the self-consistent shear flow, In the solar active regions where the resonant absorption of Alfven waves is believed to occur, the instability may lead to turbulent enhancement of the dissipation parameters and account for the observed turbulent velocities inferred from the nonthermal broadening of x-ray and EUV emission lines, The self consistent J x B force changes significantly the density structure of the loop that leads to a shift in the global mode frequency response of the loop and a subsequent drop in the heating rate, In the solar corona the density evolution of the loop is likely to be dominated by evaporation of material from the transition region. C1 HUGHES STX CORP,GREENBELT,MD. RP OFMAN, L (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. NR 29 TC 68 Z9 68 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1995 VL 100 IS A12 BP 23427 EP 23441 DI 10.1029/95JA01907 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH672 UT WOS:A1995TH67200006 ER PT J AU GOLDEN, RL STEPHENS, SA STOCHAJ, SJ WEBBER, WR BRUNETTI, MT CODINO, A GRIMANI, C MENICHELLI, M SALVATORI, I DEPASCALE, MP MORSELLI, A PICOZZA, P BASINI, G BONGIORNO, F BRANCACCIO, FM RICCI, M ORMES, JF STREITMATTER, RE PAPINI, P PICCARDI, S SPILLANTINI, P AF GOLDEN, RL STEPHENS, SA STOCHAJ, SJ WEBBER, WR BRUNETTI, MT CODINO, A GRIMANI, C MENICHELLI, M SALVATORI, I DEPASCALE, MP MORSELLI, A PICOZZA, P BASINI, G BONGIORNO, F BRANCACCIO, FM RICCI, M ORMES, JF STREITMATTER, RE PAPINI, P PICCARDI, S SPILLANTINI, P TI MEASUREMENT OF THE ENERGY-SPECTRA OF COSMIC-RAY ELECTRON COMPONENT AND PROTONS AT GROUND-LEVEL SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CHARGE RATIO; SEA-LEVEL; MUONS AB Using a superconducting magnet spectrometer, we have measured the energy spectra of electrons, positrons, and protons at ground level at an atmospheric depth of 945 g/cm(2). The differential energy spectrum of the electron component has been determined in the momentum interval between 0.1 and 2.0 GeV/c. This spectrum can be described by two power laws, one below 600 MeV with a spectral index of -1.8 +/- 0.1 and the other above this energy with an index of -2.9 +/- 0.2. The absolute flux values measured here are not in agreement with the earlier results. The fraction of positrons varies from a value of 0.45 at 200 MeV to about 0.5 above 1 GeV, which is consistent with the theoretical expectation. The momentum dependence of the e/mu ratio in the region between 0.25 and 2.0 GeV/c is proportional to p(-2.2), and it appears that the soft component of the ionizing radiation might dominate at ground level at kinetic energies below about 70 MeV. The proton energy spectrum has been determined as a power law in kinetic energy between 2.9 and 19.1 GeV with a spectral index of -2.66 +/- 0.26. The p/mu ratio obtained from this experiment seems to have a steeper momentum dependence than from previous experiments. C1 TATA INST FUNDAMENTAL RES,BOMBAY 400005,MAHARASHTRA,INDIA. UNIV PERUGIA,DIPARTIMENTO FIS,I-06100 PERUGIA,ITALY. IST NAZL FIS NUCL,I-06100 PERUGIA,ITALY. UNIV ROMA TOR VERGATA,DIPARTIMENTO FIS,I-00173 ROME,ITALY. UNIV ROMA TOR VERGATA,IST NAZL FIS NUCL,I-00173 ROME,ITALY. IST NAZL FIS NUCL,NAZL FRASCATI LAB,I-00044 FRASCATI,ITALY. UNIV ROMA 3,DIPARTIMENTO ELECTR,ROME,ITALY. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV FLORENCE,DIPARTIMENTO FIS,I-50144 FLORENCE,ITALY. IST NAZL FIS NUCL,I-50125 FLORENCE,ITALY. RP GOLDEN, RL (reprint author), NEW MEXICO STATE UNIV,PARTICLE ASTROPHYS LAB,LAS CRUCES,NM 88003, USA. RI Morselli, Aldo/G-6769-2011 OI Morselli, Aldo/0000-0002-7704-9553 NR 14 TC 10 Z9 10 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1995 VL 100 IS A12 BP 23515 EP 23522 DI 10.1029/95JA02449 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH672 UT WOS:A1995TH67200013 ER PT J AU GALLAGHER, DL CRAVEN, PD COMFORT, RH MOORE, TE AF GALLAGHER, DL CRAVEN, PD COMFORT, RH MOORE, TE TI ON THE AZIMUTHAL VARIATION OF CORE PLASMA IN THE EQUATORIAL MAGNETOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTRON-DENSITY; OUTER PLASMASPHERE; WHISTLER EVIDENCE; DUSKSIDE BULGE; CONVECTION; MODEL; REGION; MORPHOLOGY; BEHAVIOR; RECOVERY AB Previous results of plasmapause position surveys have been synthesized into a description of the underlying global distribution of plasmasphere-like or core plasma densities unique to a steady state magnetosphere. Under these steady conditions, the boundary between high- and low-density regions is taken to represent the boundary between diurnal near-corotation and large-scale circulation streamlines that traverse the entire magnetosphere. Results indicate a boundary that has a pronounced bulge in the dusk sector that is rotated westward and markedly reduced in size at increased levels of geomagnetic activity (and presumably magnetospheric convection). The derived profile is empirical confirmation of an underlying distribution of core plasma, which is valid only for prolonged steady conditions and is somewhat different from that associated with the simple superposition of sunward flow and corotation, both in its detailed shape and in its varying orientation. Variation away from the tear drop profile suggests that magnetospheric circulation departs from a uniform flow field, having a radial dependence with respect to the Earth that is qualitatively consistent with electrostatic shielding of the convection electric field and which is rotated westward at increased levels of geophysical activity. C1 UNIV ALABAMA,CTR SPACE PLASMA & AERON RES,HUNTSVILLE,AL 35899. RP GALLAGHER, DL (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812, USA. RI Moore, Thomas/D-4675-2012 OI Moore, Thomas/0000-0002-3150-1137 NR 42 TC 34 Z9 34 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1995 VL 100 IS A12 BP 23597 EP 23605 DI 10.1029/95JA02100 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH672 UT WOS:A1995TH67200020 ER PT J AU NEMZEK, RJ NAKAMURA, R BAKER, DN BELIAN, RD MCCOMAS, DJ THOMSEN, MF YAMAMOTO, T AF NEMZEK, RJ NAKAMURA, R BAKER, DN BELIAN, RD MCCOMAS, DJ THOMSEN, MF YAMAMOTO, T TI THE RELATIONSHIP BETWEEN PULSATING AURORAS OBSERVED FROM THE GROUND AND ENERGETIC ELECTRONS AND PLASMA-DENSITY MEASURED AT GEOSYNCHRONOUS ORBIT SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WAVE-PARTICLE INTERACTIONS; PITCH ANGLE DIFFUSION; NONLINEAR MODEL; MAGNETOSPHERE; PREDICTIONS; ANALYZER AB We present comparisons of ground-based all-sky video recordings of pulsating auroral events and magnetically conjugate geosynchronous orbit measurements of high-energy electrons and low-energy plasma. The large-scale pulsation events were found to be closely tied to substorm electron injections. For most events, only upper limits were available for the plasma density, which was less than or equal to 1-2 cm(-3). We were unable to find any clear dependence between the plasma density and the pulsations. There were, however, small, rapid fluctuations in the density which had apparent spatial scales similar to those of individual pulsating auroral patches. These simultaneous measurements of the electron flux, plasma density, and pulsation period should be of use in constraining theoretical treatments of the pulsating aurora problem. We find that the conditions for minimum plasma density and plasma density gradient predicted by Demekhov and Trakhtengerts (1994) may not be supported by the geosynchronous data but that their prediction for minimum energetic electron density is supported. Predictions by Davidson and Chiu (1987) of the minimum change in plasma density and electron flux also seem to be supported, The data indicate that the principal factor controlling the onset of pulsations over a particular area may be the arrival of substorm-injected electrons at the conjugate equator. This conclusion could provide the basis for a visible magnetic mapping of the substorm injection region through observations of the pulsating aurora. C1 SOLAR TERR ENVIRONM LAB,TOYOKAWA,JAPAN. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV COLORADO,ATMOSPHER & SPACE PHYS LAB,BOULDER,CO 80309. INST SPACE & ASTRONAUT SCI,SAGAMIHARA,KANAGAWA 229,JAPAN. RP NEMZEK, RJ (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87544, USA. RI Nakamura, Rumi/I-7712-2013 OI Nakamura, Rumi/0000-0002-2620-9211 NR 32 TC 26 Z9 26 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1995 VL 100 IS A12 BP 23935 EP 23944 DI 10.1029/95JA01756 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH672 UT WOS:A1995TH67200050 ER PT J AU GHOSH, S MAHAJAN, KK GREBOWSKY, JM NATH, N AF GHOSH, S MAHAJAN, KK GREBOWSKY, JM NATH, N TI MORPHOLOGY OF O++ IONS AND THEIR MAINTENANCE IN THE NIGHTSIDE VENUS IONOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR EUV; PLASMASPHERE; MODEL; THERMOSPHERE; TRANSPORT; FLOW AB In this paper, measurements made by the Pioneer Venus orbiter ion mass spectrometer are used to study the temporal and spatial distribution of O++ ion concentrations in the Venus ionosphere. The diurnal analysis shows an enhancement of O++ around midnight. On the nightside the O++ densities are highly variable but show a positive correlation with variations in the O+ densities, Model calculations of O++ concentrations in the nightside are made assuming that impact ionization by precipitating electrons and transport of ions from the dayside were the sources for O++ ions. We find that in situ ionization by precipitating electrons contributes very little, whereas a downward O++ flux in the range of 10(5) to 10(6) cm(-2) s(-1) can account for the measured values of O++ densities near midnight, The high abundance of O++ near midnight is related to the special characteristics of multiply charged ions. Because of the double charge, thermal diffusion and the polarization electric field are particularly found to be significant factors in the momentum equations for O++, and therefore the downward velocity for O++ is small compared with that of other ions. High O++ densities are observed to occur under low solar wind dynamic pressure conditions, consistent with the transterminator transport mechanism as the source of O++ ions in the antisolar region. C1 NASA, GODDARD SPACE FLIGHT CTR, ATMOSPHERES LAB, GREENBELT, MD 20771 USA. UNIV DELHI, DEPT PHYS & ASTROPHYS, DELHI 110007, INDIA. RP GHOSH, S (reprint author), NATL PHYS LAB, DR KS KRISHNAN RD, NEW DELHI 110012, INDIA. RI Grebowsky, Joseph/I-7185-2013 NR 26 TC 2 Z9 2 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1995 VL 100 IS A12 BP 23983 EP 23991 DI 10.1029/95JA01581 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH672 UT WOS:A1995TH67200055 ER PT J AU JOHNSON, FS HANSON, WB HODGES, RR COLEY, WR CARIGNAN, GR SPENCER, NW AF JOHNSON, FS HANSON, WB HODGES, RR COLEY, WR CARIGNAN, GR SPENCER, NW TI GRAVITY-WAVES NEAR 300 KM OVER THE POLAR CAPS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Note AB Distinctive wave forms in the distributions of vertical velocity and temperature of both neutral particles and ions are frequently observed from Dynamics Explorer 2 at altitudes above 250 bm over the polar caps. These are interpreted as being due to internal gravity waves propagating in the neutral atmosphere. The disturbances are characterized by vertical velocity perturbations of the order of 100 m/s and horizontal wave lengths along the satellite path of about 500 lan. They often extend across the entire polar cap. The associated temperature perturbations indicate that the horizontal phase progression is from the nightside to the dayside. Vertical displacements are inferred to be of the order of 10 bm and the periods to be of the order of 10(3) s. The waves must propagate in the neutral atmosphere, but they usually are most clearly recognizable in the observations of ion vertical velocity and ion temperature. By combining the neutral pressure calculated from the observed neutral concentration and temperature with the vertical component of the neutral velocity, an upward energy flux of the order of 0.04 erg/cm(2)-s at 250 lan has been calculated, which is about equal to the maximum total solar ultraviolet heat input above that altitude. Upward energy fluxes calculated from observations on orbital passes at altitudes from 250 to 560 lan indicate relatively little attenuation with altitude. C1 UNIV MICHIGAN,ANN ARBOR,MI 48109. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP JOHNSON, FS (reprint author), UNIV TEXAS,CTR SPACE SCI,BOX 830688,RICHARDSON,TX 75083, USA. NR 12 TC 33 Z9 33 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1995 VL 100 IS A12 BP 23993 EP 24002 DI 10.1029/95JA02858 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TH672 UT WOS:A1995TH67200056 ER PT J AU Whittenberger, JD AF Whittenberger, JD TI Tensile properties and structure of several superalloys after long-term exposure to LIF and vacuum at 1173 K SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE chemical compatibility; Hastelloy B-2; Haynes alloy 188; Haynes alloy 230; microstructure; superalloys; tensile properties; thermal energy storage ID 1093-K; LIF-22CAF2; AIR AB The use of the solid-to-liquid phase transformation of LiF to store thermal energy is under consideration for a space-based solar dynamic system. Although advantageous in terms of its energy density, the melting point of this salt (1121 K) is beyond the commonly accepted upper-use temperature of 1100 K for chromium-bearing superalloys in vacuum. However, one commercially available nickel-base superalloy (Hastelloy B-2) is chromium free; unfortunately, because of its high molybdenum content, this alloy can form phases that cause high-temperature embrittlement. To test the suitability of Hastelloy B-2, it has been exposed to molten LiF, its vapor and vacuum at 1173 K for 2500, 5000, and 10(4) h. For control, the chromium-containing cobalt-base Haynes alloy 188 and nickel-base Haynes alloy 230 were also exposed to LiF and vacuum at 1173 K for 5000 h. Neither LiF nor vacuum exposures had any significant effect on Hastelloy B-2 in terms of microstructural surface damage or weight change. Measurement of the post exposure tensile properties of Hastelloy B-2, nevertheless, revealed low tensile ductility at 1050 K. Such embrittlement and low strength at elevated temperatures appear to preclude the use of Hastelloy B-2 as a containment material for LiF. Little evidence of significant attack by LiF was seen in either of the chromium-containing superalloys; however, considerable weight loss and near-surface microstructural damage occurred in both alloys exposed to vacuum. Although measurement of the post exposure room-temperature tensile properties of Haynes alloys 188 and 230 revealed no significant loss of strength or ductility, the severe degree of microstructural damage found in unshielded alloys exposed to vacuum indicates that chromium-bearing superalloys might also be unsuitable for prolonged containment of LiF in space above 1100 K. RP Whittenberger, JD (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 20 TC 1 Z9 1 U1 1 U2 5 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD DEC PY 1995 VL 4 IS 6 BP 657 EP 673 DI 10.1007/BF02646442 PG 17 WC Materials Science, Multidisciplinary SC Materials Science GA TL960 UT WOS:A1995TL96000003 ER PT J AU ZANNIAS, T AF ZANNIAS, T TI BLACK-HOLES CANNOT SUPPORT CONFORMAL SCALAR HAIR SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID PROOF; MASS; UNIQUENESS; EQUATIONS; HORIZONS; FIELDS AB It is shown that the only static asymptotically flat nonextrema black hole solution of the Einstein-conformally invariant scalar field equations having the scalar field bounded on the horizon is the Schwarzschild solution. (C) 1995 American Institute of Physics. RP ZANNIAS, T (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. NR 31 TC 32 Z9 32 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD DEC PY 1995 VL 36 IS 12 BP 6970 EP 6980 DI 10.1063/1.531201 PG 11 WC Physics, Mathematical SC Physics GA TH605 UT WOS:A1995TH60500033 ER PT J AU Melen, F Sauval, AJ Grevesse, N Farmer, CB Servais, C Delbouille, L Roland, G AF Melen, F Sauval, AJ Grevesse, N Farmer, CB Servais, C Delbouille, L Roland, G TI A new analysis of the OH radical spectrum from solar infrared observations SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID BEAM ELECTRIC RESONANCE; LABORATORY MEASUREMENT; ROTATIONAL SPECTRUM; EMISSION-SPECTRUM; LINES; SPECTROSCOPY; STATES; OD; CO AB The solar spectrum offered the opportunity to discover OH lines with high rotational quantum numbers, which do not appear on laboratory spectra. On solar absorption spectra, we have identified about 580 lines, among which about 400 were observed for the first time. They belong to pure rotational transitions in the ground state (upsilon = 0 --> 3; J(max)'' = 48.5), as well as to the (1-0), (2-1), and (3-2) vibration-rotation bands (J(max)'' = 32.5). Previous pure rotation, vibration-rotation, and Lambda-doubling data sets related to the upsilon = 0 up to 3 levels were fitted simultaneously together with this new set of data in order to obtain a very complete and accurate set of molecular constants for the X(2) Pi ground state. (C)1995 Academic Press, Inc. C1 OBSERV ROYAL BELGIQUE,B-1180 BRUSSELS,BELGIUM. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Melen, F (reprint author), UNIV LIEGE,INST ASTROPHYS,5 AVE COINTE,B-4000 LIEGE,BELGIUM. NR 49 TC 42 Z9 42 U1 1 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 1995 VL 174 IS 2 BP 490 EP 509 DI 10.1006/jmsp.1995.0018 PG 20 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA TN850 UT WOS:A1995TN85000018 ER PT J AU REUTER, DC SIROTA, JM AF REUTER, DC SIROTA, JM TI TEMPERATURE-DEPENDENT FOREIGN GAS BROADENING COEFFICIENTS OF THE R(42) AND P(13) LINES IN THE NU(1) BAND OF N2O SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article AB Foreign gas broadening coefficients of the R(42) and P(13) transitions in the nu(1) band of N2O near 1285 cm(-1) have been measured at a spectral resolution of similar to 5 x 10(-4) cm(-1) using tunable diode laser spectrometry. Ar, He, N-2, and O-2 were used as the broadening gases. In order to determine the temperature dependence of the broadening coefficients, data were obtained at temperatures ranging from 154 to 294 K. C1 NASA,GODDARD SPACE FLIGHT CTR,PLANETARY SYST BRANCH,GREENBELT,MD 20771. NR 4 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD DEC PY 1995 VL 54 IS 6 BP 957 EP 960 DI 10.1016/0022-4073(95)00127-7 PG 4 WC Optics; Spectroscopy SC Optics; Spectroscopy GA TH123 UT WOS:A1995TH12300005 ER PT J AU TAHMASEBI, F TSAI, LW AF TAHMASEBI, F TSAI, LW TI ON THE STIFFNESS OF A NOVEL 6-DEGREE-OF-FREEDOM PARALLEL MINIMANIPULATOR SO JOURNAL OF ROBOTIC SYSTEMS LA English DT Article ID DESIGN AB The dimensionally uniform Jacobian matrix of a novel three-limbed, six degree-of-freedom (DOF) minimanipulator is used to derive its dimensionally uniform stiffness matrix. The minimanipulator limbs are inextensible and its actuators are base-mounted. The lower ends of the limbs are connected to bidirectional linear stepper motors that are constrained to move on a base plane. The minimanipulator is capable of providing high positional resolution and high stiffness. It is shown that, at a central configuration, the stiffness matrix of the minimanipulator can be decoupled (diagonalized), if proper design parameters are chosen. It is also shown that the stiffness of the minimanipulator is higher than that of the Stewart platform. Guidelines for obtaining large minimanipulator stiffness values are established. (C) 1995 John Wiley & Sons, Inc. C1 UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742. UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742. UNIV MARYLAND,SYST RES INST,COLLEGE PK,MD 20742. RP TAHMASEBI, F (reprint author), NASA,GODDARD SPACE FLIGHT CTR,SYST ANAL BRANCH,CODE 661,GREENBELT,MD 20771, USA. NR 14 TC 25 Z9 26 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0741-2223 J9 J ROBOTIC SYST JI J. Robot. Syst. PD DEC PY 1995 VL 12 IS 12 BP 845 EP 856 DI 10.1002/rob.4620121208 PG 12 WC Robotics SC Robotics GA TE750 UT WOS:A1995TE75000007 ER PT J AU Rosekind, MR Smith, RM Miller, DL Co, EL Gregory, KB Webbon, LL Gander, PH Lebacqz, JV AF Rosekind, MR Smith, RM Miller, DL Co, EL Gregory, KB Webbon, LL Gander, PH Lebacqz, JV TI Alertness management: Strategic naps in operational settings SO JOURNAL OF SLEEP RESEARCH LA English DT Article; Proceedings Paper CT Meeting on Work Hours, Sleepiness and Accidents CY SEP, 1994 CL STOCKHOLM, SWEDEN SP Natl Inst Psychosocial Factors & Hlth, Karolinska Inst, Dept Clin Neurosci, Swedish Work Environm Fund, Swedish Nucl Inspectorate, European Sleep Res Soc DE alertness management; sleep inertia; strategic naps ID PERFORMANCE; WAKEFULNESS; SLEEP; EEG AB Managing fatigue in complex operational settings requires attention to multiple factors, including hours of service, scheduling, education and training, counter-measures, technology, and research. Alertness-management strategies can be used to promote safety, performance, and productivity in operational settings. These strategies can involve both preventive (used prior to duty/shift) and operational (used during duty/shift) approaches. Studies have demonstrated the effectiveness of naps to improve subsequent performance and alertness. Strategic naps can be used effectively to promote performance and alertness in operational settings. Two potential negative effects of naps, sleep inertia and effects on subsequent sleep periods, are discussed. Sleep inertia can involve sleepiness and decreased performance immediately upon awakening from a nap. It should be a consideration prior to implementing nap strategies in work environments. A study of planned rest periods in long-haul flight operations demonstrated the effectiveness of in-fight naps to promote performance and alertness during subsequent critical phases of flight (descent and landing). Empirical evaluation of alertness-management strategies during regular operations will be critical to their implementation. Combining strategies may be the most effective approach to managing fatigue engendered by 24-h operational demands. Other considerations prior to implementing alertness-management strategies in operational environments are discussed. C1 SAN JOSE STATE UNIV FDN,SAN JOSE,CA. STERLING SOFTWARE,PALO ALTO,CA. RP Rosekind, MR (reprint author), NASA,AMES RES CTR,MS 262-4,MOFFETT FIELD,CA 94035, USA. NR 28 TC 66 Z9 67 U1 2 U2 6 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0962-1105 J9 J SLEEP RES JI J. Sleep Res. PD DEC PY 1995 VL 4 SU 2 BP 62 EP 66 PG 5 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA TQ499 UT WOS:A1995TQ49900011 ER PT J AU Gultepe, I Starr, DO Heymsfield, AJ Uttal, T Ackerman, TP Westphal, DL AF Gultepe, I Starr, DO Heymsfield, AJ Uttal, T Ackerman, TP Westphal, DL TI Dynamical characteristics of cirrus clouds from aircraft and radar observations in micro and meso-gamma scales SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID FIRE; EVOLUTION AB Cirrus clouds that formed on 26 November and 6 December 1991 during the First International Satellite Cloud Climatology Project Regional Experiment (FIRE) II, which took place over the Kansas region, are studied because of significant dynamic activity in the micro (< 1 km) and meso gamma (< 25 km) scales within the cloud. Observations are obtained from the NCAR King Air, NOAA Doppler, and PSU conventional radar. For this reason coherent structures (e.g., cells, vortex) that transfer significant heat, moisture, and turbulence are analyzed using aircraft and radar observations. Aircraft data is collected at 20 Hz, and calculations are made at two different scales. Scale separation is chosen at about 1 km. A coherence analysis technique is used to specify the correlation between temperature and vertical velocity w fluctuations. A swirling coefficient, indicating spirality, is calculated to better understand cloud dynamics. Sensible heat, latent heat, and radiative fluxes are compared with each other in two scales. Results showed that dynamic activity, including w about +/- 1.5 m s(-1), and mean sensible heat fluxes (SHFs) and latent heat fluxes (LHFs) similar to 10 W m(-2), is estimated to be much larger for the 26 November case compared to the 6 December case. The swirling coefficient is estimated to be larger in upper and lower levels compared to those in middle levels for both days. Individual values of SHFs and LHFs are also found to be comparable with those of FIRE I. The size of coherent structures is estimated from aircraft and radar measurements to be about 0.5 and 3.5 km. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NCAR,BOULDER,CO. NOAA,ETL,BOULDER,CO. PENN STATE UNIV,UNIVERSITY PK,PA 16802. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP Gultepe, I (reprint author), AES,ARMP,DIV CLOUD PHYS RES,4905 DUFFERIN ST,DOWNSVIEW,ON M3H 5T4,CANADA. RI Heymsfield, Andrew/E-7340-2011 NR 41 TC 19 Z9 19 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1995 VL 52 IS 23 BP 4060 EP 4078 DI 10.1175/1520-0469(1995)052<4060:DCOCCF>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TL538 UT WOS:A1995TL53800003 ER PT J AU Mace, GG Starr, DO Ackerman, TP Minnis, P AF Mace, GG Starr, DO Ackerman, TP Minnis, P TI Examination of coupling between an upper-tropospheric cloud system and synoptic-scale dynamics diagnosed from wind profiler and radiosonde data SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID FRONTAL ZONE SYSTEMS; CIRRUS CLOUDS; MODEL; PARAMETERIZATION; CIRCULATIONS; DIVERGENCE; MESOSCALE; SCHEME AB The evolution of synoptic-scale dynamics associated with a middle and upper tropospheric cloud event that occurred on 26 November 1991 is examined. The case under consideration occurred during the FIRE Cirrus-II Intensive Field Observing Period held in Coffeyville, Kansas, during November-December 1991. Using data from the wind profiler demonstration network and a temporally and spatially augmented radiosonde array, emphasis is given to explaining the evolution of the kinematically derived ageostrophic vertical circulations and correlating the circulation with the forcing of an extensively sampled cloud field. This is facilitated by decomposing the horizontal divergence into its component parts through a natural coordinate representation of the flow. Ageostrophic vertical circulations are inferred and compared to the circulation forcing arising from geostrophic confluence and shearing deformation derived from the Sawyer-Eliassen equation. It is found that a thermodynamically indirect vertical circulation existed in association with a jet streak exit region. The circulation was displaced to the cyclonic side of the jet axis due to the orientation of the jet exit between a deepening diffluent trough and a building ridge. The cloud line formed in the ascending branch of the vertical circulation, with the most concentrated cloud development occurring in conjunction with the maximum large-scale vertical motion. The relationship between the large-scale dynamics and the parameterization of middle and upper tropospheric clouds in large-scale models is discussed, and an example of ice water contents derived from a parameterization forced by the diagnosed vertical motions and observed water vapor contents is presented. C1 NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771. PENN STATE UNIV,DEPT METEOROL,UNIVERSITY PK,PA 16802. NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,HAMPTON,VA 23665. RP Mace, GG (reprint author), PENN STATE UNIV,COLL EARTH & MINERAL SCI,DEPT METEOROL,503 WALKER BLDG,UNIVERSITY PK,PA 16802, USA. RI Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 42 TC 23 Z9 23 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1995 VL 52 IS 23 BP 4094 EP 4127 DI 10.1175/1520-0469(1995)052<4094:EOCBAU>2.0.CO;2 PG 34 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TL538 UT WOS:A1995TL53800005 ER PT J AU Ou, SC Liou, KN Takano, Y Rao, NX Fu, Q Heymsfield, AJ Miloshevich, LM Baum, B Kinne, SA AF Ou, SC Liou, KN Takano, Y Rao, NX Fu, Q Heymsfield, AJ Miloshevich, LM Baum, B Kinne, SA TI Remote sounding of cirrus cloud optical depths and ice crystal sizes from AVHRR data: Verification using FIRE II IFO measurements SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SOLAR RADIATIVE-TRANSFER; SATELLITE DATA; PARAMETERIZATION; SCATTERING; CHANNELS AB Using the data obtained from the Advanced Very High Resolution Radiometer (AVHRR) 3.7-mu m and 10.9-mu m channels, a retrieval scheme has been developed to simultaneously infer cirrus cloud optical depth and mean effective ice crystal size based on the theory of radiative transfer and parameterizations. A numerical scheme is further developed to remove the solar component in the 3.7-mu m radiance for applications to daytime satellite data. This scheme is based on the correlation between the 3.7-mu m (solar) and 0.63-mu m reflectances. Validation of the algorithm has been performed by using various datasets that were collected during the FIRE-II IFO (Nov-Dec 1991) at Coffeyville, Kansas. We have focused on the 26 November and 5 December cases. The retrieval analysis over a 0.5 degrees x 1.0 degrees area is performed around Coffeyville for each case based on AVHRR-HRPT data. For validation the authors analyze the photomicrograph data collected by the balloonborne replicator, determine the microphysical and optical properties of the sampled cirrus clouds, and derive their position at the satellite overpass based on sounding data. It is demonstrated that the retrieved cirrus cloud temperature, mean effective ice crystal size, and optical depth closely match the observed values. Further, the retrieved cirrus cloud properties are applied to the computation of surface radiative fluxes using a radiative transfer program that involves a consistent representation of cirrus cloud fields. The computed values are compared with the data measured from ground-based radiometers, and it is shown that the computed downward surface IR and solar fluxes are within 5 and 10 W m(-2) of the measured values, respectively, near the time of satellite overpass. C1 NCAR,BOULDER,CO. NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,HAMPTON,VA 23665. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP Ou, SC (reprint author), UNIV UTAH,DEPT METEOROL,CARSS,809 WILLIAM C BROWNING BLDG,SALT LAKE CITY,UT 84112, USA. RI Baum, Bryan/B-7670-2011; Heymsfield, Andrew/E-7340-2011 OI Baum, Bryan/0000-0002-7193-2767; NR 26 TC 47 Z9 49 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1995 VL 52 IS 23 BP 4143 EP 4158 DI 10.1175/1520-0469(1995)052<4143:RSOCCO>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TL538 UT WOS:A1995TL53800007 ER PT J AU Gultepe, I Starr, DO AF Gultepe, I Starr, DO TI Dynamical structure and turbulence in cirrus clouds: Aircraft observations during FIRE SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID OCTOBER 1986 FIRE; GENERAL-CIRCULATION MODEL; MICROSCALE STRUCTURE; RADIATIVE PROCESSES; BOUNDARY-LAYER; GRAVITY-WAVES; ATMOSPHERE; MESOSCALE; LIDAR; PRECIPITATION AB Aircraft data collected during the First International Satellite Cloud Climatology Project Regional Experiment (FIRE)I are used to examine dynamical processes operating in cirrus cloud systems observed on 19 and 28 October 1986. Measurements from Lagrangian spiral soundings and constant-altitude Eight legs are analyzed. Comparisons are made with observations in clear air. Each cirrus case contained a statically stable layer, a conditionally unstable or neutrally stratified layer (ice pseudoadiabatic)in which convection was prevalent, and a neutral layer in which convection was intermittent; The analysis indicates that a mixture of phenomena occurred including small-scale convective cells, gravity waves (lambda approximate to 2-9 km), quasi-two-dimensional waves (lambda approximate to 10-20 km), and larger two-dimensional mesoscale waves (lambda approximate to 100 km). The intermediate-scale waves, observed both in clear air and in the cloud systems, likely played an important role in the development of the cloud systems given the magnitude of the associated vertical air velocity. The spectra of perturbations of wind components for layers where convection was prevalent were characterized by a kappa(-5/3) power law dependence, while a kappa(-2/4) dependence was found at other levels in the cloud systems. A steeper spectral slope (kappa(-3)) was found in the more stable cloud-base layer on 19 October. Samples in clear air also showed a (kappa(-2.4)) dependence. Flight-leg-averaged eddy potential heat fluxes (H = +/- 8 W m(-2)) were comparable to observations in marine stratocumulus clouds. Calculated turbulence dissipation rates agree with previously published studies, which indicate a general enhancement within cloud systems (10(-6) to 10(-3) m(2) s(-3) in cloud versus values less than 0.5 x 10(-6) m(2) s(-3) in clear air). C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 70 TC 58 Z9 59 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1995 VL 52 IS 23 BP 4159 EP 4182 DI 10.1175/1520-0469(1995)052<4159:DSATIC>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TL538 UT WOS:A1995TL53800008 ER PT J AU Han, Q Rossow, W Welch, R White, A Chou, J AF Han, Q Rossow, W Welch, R White, A Chou, J TI Validation of satellite retrievals of cloud microphysics and liquid water path using observations from FIRE SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID PLANETARY ATMOSPHERES; STRATOCUMULUS CLOUDS; MULTIPLE-SCATTERING; OPTICAL-THICKNESS; SOLAR-RADIATION; RADIOMETER; ALBEDO; LIGHT; ISCCP AB Cloud effective radii (r(e)) and cloud liquid water path (LWP) are derived from ISCCP spatially sampled satellite data and validated with ground-based pyranometer and microwave radiometer measurements taken on San Nicolas Island during the 1987 FIRE IFO. Values of r(e) derived from the ISCCP data are also compared to values retrieved by a hybrid method that uses the combination of LWP derived from microwave measurement and optical thickness derived from GOES data. The results show that there is significant variability in cloud properties over a 100 km x 80 km area and that the values at San Nicolas Island are not necessarily representative of the surrounding cloud field. On the other hand, even though there were large spatial variations in optical depth, the r(e) values remained relatively constant (with sigma less than or equal to 2-3 mu m in most cases) in the marine stratocumulus. Furthermore, values of r(e) derived from the upper portion of the cloud generally are representative of the entire stratiform cloud. When LWP values are less than 100 g m(-2), then LWP values derived from ISCCP data agree well with those values estimated from ground-based microwave measurements. In most cases LWP differences were less than 20 g m(-2). However, when LWP values become large (e.g., greater than or equal to 200 g m(-2)), then relative differences may be as large as 50%-100%. There are two reasons for this discrepancy in the large LWP clouds: 1) larger vertical inhomogeneities in precipitating clouds and 2) sampling errors on days of high spatial variability of cloud optical thicknesses. Variations of r(e) in stratiform clouds may indicate drizzle: clouds with droplet sizes larger than 15 mu m appear to be associated with drizzling, while those less than 10 mu m are indicative of nonprecipitating clouds. Differences in r(e) values between the GOES and ISCCP datasets are found to be 0.16 +/- 0.98 mu m. C1 NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025. NOAA,ERL,ETL,BOULDER,CO 80303. RP Han, Q (reprint author), S DAKOTA SCH MINES & TECHNOL,INST ATMOSPHER SCI,501 E ST JOSEPH ST,RAPID CITY,SD 57701, USA. RI Rossow, William/F-3138-2015 NR 30 TC 56 Z9 59 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1995 VL 52 IS 23 BP 4183 EP 4195 DI 10.1175/1520-0469(1995)052<4183:VOSROC>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TL538 UT WOS:A1995TL53800009 ER PT J AU Baum, BA Uttal, T Poellot, M Ackerman, TP Alvarez, JM Intrieri, J Starr, DO Titlow, J Tovinkere, V Clothiaux, E AF Baum, BA Uttal, T Poellot, M Ackerman, TP Alvarez, JM Intrieri, J Starr, DO Titlow, J Tovinkere, V Clothiaux, E TI Satellite remote sensing of multiple cloud layers SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID OCTOBER 1986 FIRE; SPATIAL-RESOLUTION; CIRRUS CLOUD; LIDAR; SOUNDER; COVER AB The goals of the current study are threefold: 1) to present a multispectral, multiresolution (MSMR) methodology for analysis of scenes containing multiple cloud layers; 2) to apply the MSMR method to two multilevel cloud scenes recorded by the NOAA Advanced Very High Resolution Radiometer (AVHRR) and the High Resolution Infrared Radiometer Sounder (HIRS/2) instruments during the First International Satellite Cloud Climatology Program (ISCCP) Regional Experiment (FIRE) on 28 November 1991; and 3) to validate the cloud-top height results from the case study analyses through comparison with lidar, radar, aircraft, and rawinsonde data; The measurements available from FIRE Cirrus II enable detailed examination of two complex cloud scenes in which cirrus and stratus appear simultaneously. A ''fuzzy logic'' classification system is developed to determine whether a 32 x 32 array of AVHRR data contains clear sky, low-level cloud, midlevel cloud, high-level cloud, or multiple cloud layers. With the addition of the fuzzy logic cloud classification system, it is possible for the first time to End evidence of more than one cloud layer within each HIRS field of view. Low cloud heights are determined through application of the spatial coherence method to the AVHRR data, while mid- to high-level cloud heights are calculated from the HIRS/2 15-mu m CO2 band radiometric data that are collocated with the AVHRR data. Cirrus cloud heights retrieved from HIRS 15-mu m CO2 band data are improved for optically thin cirrus through the use of the upper-tropospheric humidity profile. The MSMR-derived cloud heights are consistent with coincident lidar, radar, and aircraft data. Cirrus and stratus cloud-top heights and cirrus effective emittances are retrieved for data within an ISCCP 2.5 degrees grid cell that encompasses the FIRE experimental region. C1 NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO. UNIV N DAKOTA,GRAND FORKS,ND 58201. PENN STATE UNIV,UNIVERSITY PK,PA 16802. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. LOCKHEED ENGN & SCI CO,HAMPTON,VA 23666. RP Baum, BA (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,MS 420,HAMPTON,VA 23681, USA. RI Baum, Bryan/B-7670-2011; Intrieri, Janet/D-5608-2015 OI Baum, Bryan/0000-0002-7193-2767; NR 40 TC 40 Z9 41 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1995 VL 52 IS 23 BP 4210 EP 4230 DI 10.1175/1520-0469(1995)052<4210:SRSOMC>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TL538 UT WOS:A1995TL53800011 ER PT J AU Gao, BC Kaufman, YJ AF Gao, BC Kaufman, YJ TI Selection of the 1.375-mu m MODIS channel for remote sensing of cirrus clouds and stratospheric aerosols from space SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID WATER-VAPOR; RADIOMETER; ALGORITHM; EARTH; LAYER AB Using spectral imaging data acquired with the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) from an ER-2 aircraft at 20-km altitude during the NASA FIRE Phase II Cirrus field program, it was found that narrow channels near the center of the strong 1.38-mu m water vapor band are very effective in detecting thin cirrus clouds. The mechanisms for the cirrus detection are straightforward. In the absence of cirrus clouds, AVIRIS channels near 1.38 mu m receive little scattered solar radiance by the surface and the low-level water clouds because of the total absorption of solar radiation by atmospheric water vapor located above them. When cirrus clouds are present, however, these channels receive solar radiance scattered by the cirrus clouds that contrasts well on the black background. A near-IR channel centered at 1.375 mu m with a width of 30 nm has been selected for the Moderate Resolution Imaging Spectrometer (MODIS) for remote sensing of cirrus clouds from space. MODIS is one of the sensors on the Earth Observing System, planned to be launched in 1998. The sensitivity of the new channel for detecting thin cirrus clouds during the daytime is expected to be one to two orders of magnitude better than the infrared emission techniques. This channel can also complement measurements of stratospheric aerosols with solar occultation techniques when the stratospheric aerosol optical depths at 0.55 mu m are 0.01 or larger. C1 NASA,GODDARD SPACE FLIGHT CTR,CLIMATE & RADIAT BRANCH,GREENBELT,MD 20771. RP Gao, BC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,CODE 913,GREENBELT,MD 20771, USA. NR 31 TC 66 Z9 67 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD DEC 1 PY 1995 VL 52 IS 23 BP 4231 EP 4237 DI 10.1175/1520-0469(1995)052<4231:SOTMCF>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TL538 UT WOS:A1995TL53800012 ER PT J AU Williams, RM Kisor, A Ryan, MA AF Williams, RM Kisor, A Ryan, MA TI Time dependence of the high temperature conductivity of sodium and potassium beta''-alumina ceramics in alkali metal vapor SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID BETA-ALUMINA; INTERFACIAL IMPEDANCE; IONIC-CONDUCTIVITY; AMTEC ELECTRODES; TRANSPORT; KINETICS; BETA-''-ALUMINA; CONVERSION; EXCHANGE AB The conductivities of sodium beta ''-alumina ceramic in low pressure sodium vapor and potassium beta ''-alumina ceramic in low pressure potassium vapor have been characterized in the four-probe configuration by ac and de measurements. Porous Rh/W films deposited by a photolytic process on Na beta ''-alumina and sputtered Mo films on K beta ''-alumina were used as electrodes. Alkali vapor pressures from 0.1 to 3.0 Pa and ac signal amplitudes from 2 to 25 mV were used, with ohmic behavior observed under these conditions. Periodic interruptions of the high temperature stand were made to characterize conductivity of the solid electrolyte sample over several hundred kelvin. Conductivities dropped slightly for sodium beta ''-alumina ceramic and similar to 30% for potassium beta ''-alumina ceramic during the first 100 h of test; the conductivities were then stable over 1550 h at 1130 K for the Na beta ''-alumina ceramic and rose slightly 495 h at 1200 K for the K beta ''-alumina ceramic. The high temperature conductivities vs. temperature were characterized for the equilibrated ceramics from below 900 K to above 1200 K; both ceramics showed good fits to an Arrhenius equation obeying the Nernst-Einstein relation between resistivity and diffusion over 400 K, with activation energies of 0.07 eV for sodium beta ''-alumina ceramic and 0.27 eV for potassium beta ''-alumina ceramic. RP Williams, RM (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 49 TC 6 Z9 6 U1 1 U2 9 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD DEC PY 1995 VL 142 IS 12 BP 4246 EP 4251 DI 10.1149/1.2048491 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA TL120 UT WOS:A1995TL12000046 ER PT J AU Ryan, MA JeffriesNakamura, B Williams, RM Underwood, ML OConnor, D Kikkert, S AF Ryan, MA JeffriesNakamura, B Williams, RM Underwood, ML OConnor, D Kikkert, S TI Directly deposited current collecting grids for alkali metal thermal-to-electric converter electrodes SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID THERMOELECTRIC CONVERTER; INTERFACIAL IMPEDANCE; AMTEC ELECTRODES; TRANSPORT; KINETICS; ALUMINA AB Current collection in porous thin film electrodes on solid electrolytes has been improved by using thick film grids to decrease sheet and contact resistance in RhW and PtW electrodes. The grids are directly deposited on the solid electrolyte either by sputter- or photodeposition, and the electrode deposited over the grid. Comparison of the performance of electrodes having such underlying grids with that of electrodes without such grids has shown performance, as measured by current or power produced, to be improved by 10-30% in electrodes with grids. RP Ryan, MA (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 20 TC 7 Z9 7 U1 0 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD DEC PY 1995 VL 142 IS 12 BP 4252 EP 4256 DI 10.1149/1.2048492 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA TL120 UT WOS:A1995TL12000047 ER PT J AU Andrews, JH Khaydarov, JDV Singer, KD Hull, DL Chuang, KC AF Andrews, JH Khaydarov, JDV Singer, KD Hull, DL Chuang, KC TI Characterization of excited states of centrosymmetric and noncentrosymmetric squaraines by third-harmonic spectral dispersion SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID BOND-LENGTH ALTERNATION; DONOR-ACCEPTOR POLYENES; DOPED POLYMER SYSTEMS; OPTICAL SUSCEPTIBILITY; DYE; GENERATION AB We measured the third-harmonic spectrum for each of four squaraine dyes in chloroform. By fitting the experimental dispersion of the third-order susceptibility, gamma, to a four-level sum-over-states model, we determine the strength and the location of the lowest-lying two-photon-like transition. In each case, we find that the lowest two-photon-like state appears just above the dominant linear absorption peak in energy and that the transition moment to that state makes a significant contribution to the nonlinearity, as do transition moments to one or more higher-lying two-photon-like states in the ultraviolet. The spectra of two of these dyes contain additional features, evidencing a nonzero dipole moment difference between the ground and the first excited-state dipole moments that we attribute to asymmetry in their structures. From our measurements, we also predict the dispersion of the real and the imaginary optical Kerr susceptibilities in the near infrared for two of these dyes. (C) 1995 Optical Society of America C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP Andrews, JH (reprint author), CASE WESTERN RESERVE UNIV,DEPT PHYS,CLEVELAND,OH 44106, USA. RI Singer, Kenneth/G-6553-2011 NR 37 TC 25 Z9 25 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD DEC PY 1995 VL 12 IS 12 BP 2360 EP 2371 DI 10.1364/JOSAB.12.002360 PG 12 WC Optics SC Optics GA TK401 UT WOS:A1995TK40100005 ER PT J AU Maa, JPY Lee, CH Chen, FJ AF Maa, JPY Lee, CH Chen, FJ TI Bed shear stress measurements for VIMS Sea Carousel SO MARINE GEOLOGY LA English DT Article ID ANNULAR FLUME AB The results of bed shear stress measurements for VIMS Sea Carousel under clear-water and flat-bed conditions are presented. The measurements were made using a flush mounted hot film shear stress sensor mounted on the bottom of a laboratory version of the VIMS Sea Carousel. The experimental results confirm the relationship between the spatial-average bed shear stress, tau (Pascal), and the ring rotation speed, Omega (rpm), from a previous numerical study: tau=0.0114 Omega(1.69). The measurements show a maximum of 15% difference with that given by the equation. We also found the side wall effects extend outward less than 2.5 cm for all ring speeds and the bed shear stress distributions are reasonably uniform. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. RP Maa, JPY (reprint author), COLL WILLIAM & MARY,SCH MARINE SCI,VIRGINIA INST MARINE SCI,GLOUCESTER POINT,VA 23062, USA. NR 16 TC 11 Z9 13 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-3227 J9 MAR GEOL JI Mar. Geol. PD DEC PY 1995 VL 129 IS 1-2 BP 129 EP 136 DI 10.1016/0025-3227(95)00102-6 PG 8 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA TM826 UT WOS:A1995TM82600008 ER PT J AU Karunasiri, G Chua, SJ Park, JS Wang, KL AF Karunasiri, G Chua, SJ Park, JS Wang, KL TI Doping dependence of intersubband transitions in Si1-xGex/Si multiple quantum wells SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 1st International Conference on Low Dimensional Structures and Devices CY MAY 08-10, 1995 CL SINGAPORE, SINGAPORE DE epitaxial silicon; quantum well; doping effects; infrared spectroscopy ID ABSORPTION; LAYERS AB Effect of doping on the intersubband transition of p-type SiGe/Si multiple quantum wells has been studied. Three Si0.6Ge0.4/Si multiple quantum well structures (10 periods each) with doping concentrations from 1 x 10(19) cm(-3) to 4 x 10(20) cm(-3) grown by Si molecular beam epitaxy were used in the experiment. It was found that as the doping in the quantum well is increased the peak position of the transition moves to a higher energy. This behavior is due to the formation of delta-like potential well inside the quantum well and the collective nature of the intersubband transitions. In order to assess the experimental data, transition energies for different doping concentrations are calculated using a self-consistent scheme. The experimental data are in good agreement with the calculation if the many-body effects are incorporated. This work demonstrates the importance of doping effects in the design of quantum well IR detectors. C1 CALTECH,JET PROP LAB,MICRODEVICES SECT,PASADENA,CA 91109. UNIV CALIF LOS ANGELES,DEPT ELECT ENGN,LOS ANGELES,CA 90024. RP Karunasiri, G (reprint author), NATL UNIV SINGAPORE,DEPT ELECT ENGN,CTR OPTOELECTR,SINGAPORE 0511,SINGAPORE. NR 14 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD DEC PY 1995 VL 35 IS 1-3 BP 463 EP 466 DI 10.1016/0921-5107(95)01399-7 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA TM630 UT WOS:A1995TM63000093 ER PT J AU Yao, M Chait, A Fripp, AL Debnam, WJ AF Yao, M Chait, A Fripp, AL Debnam, WJ TI Numerical simulation of Bridgman crystal growth of PbSnTe in microgravity SO MICROGRAVITY SCIENCE AND TECHNOLOGY LA English DT Article ID FINITE-ELEMENT METHOD; DIRECTIONAL SOLIDIFICATION; SEGREGATION; CONVECTION; MELT; FLOW AB The space growth of a non-dilute pseudo binary, lead-tin-telluride, in a Bridgman crystal growth system is studied through numerical simulation. The two-dimensional pseudo-steady--state finite element model considers fully-coupled fluid motion, heat transport, solute segregation and solid/liquid phase change. The measured temperature profile is used to impose the thermal boundary conditions and the interface position is simultaneously solved by the front tracking approach. Numerical solutions based on a representative microgravity experiment are presented for both vertical and horizontal growth configurations. It is found that the interaction between thermal and solutal buoyancy forces has quite different impacts in the two growth configurations. For vertical Bridgman growth, the interaction between thermal and solutal buoyancy forces tends to significantly change the flow pattern and increase the convection strength in the melt, which results in a move complete mixing. For horizontal growth, however, the interaction between thermal and solutal buoyancy forces does not enhance the convective flow in the melt and the solutal buoyancy force contributes only to the low level of mixing near the interface. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP Yao, M (reprint author), OHIO AEROSP INST,22800 CEDAR POINT RD,BROOKPARK,OH 44142, USA. NR 31 TC 2 Z9 2 U1 1 U2 1 PU CARL HANSER VERLAG PI MUNICH PA KOLBERGERSTRASSE 22, POSTFACH 860420, W-8163 MUNICH, GERMANY SN 0938-0108 J9 MICROGRAVITY SCI TEC JI Microgravity Sci. Technol. PD DEC PY 1995 VL 8 IS 4 BP 214 EP 225 PG 12 WC Engineering, Aerospace; Thermodynamics; Mechanics SC Engineering; Thermodynamics; Mechanics GA UQ802 UT WOS:A1995UQ80200002 ER PT J AU LAUNIUS, RD AF LAUNIUS, RD TI FRONTIER FAITHS - CHURCH, TEMPLE, AND SYNAGOGUE IN LOS-ANGELES, 1846-1888 - ENGH,ME SO MONTANA-THE MAGAZINE OF WESTERN HISTORY LA English DT Book Review RP LAUNIUS, RD (reprint author), NASA,WASHINGTON,DC 20546, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MONTANA HISTORICAL SOC PI HELENA PA 225 N ROBERTS ST, HELENA, MT 59601 SN 0026-9891 J9 MONTANA JI Mont.-Mag. West. Hist. PD WIN PY 1995 VL 45 IS 1 BP 72 EP 72 PG 1 WC History SC History GA QM051 UT WOS:A1995QM05100017 ER PT J AU Espenak, F Anderson, J AF Espenak, F Anderson, J TI New NASA bulletin for the total solar eclipse of 1997 March 9 SO OBSERVATORY LA English DT Letter C1 ENVIRONM CANADA,WINNIPEG,MB R3C 3V4,CANADA. RP Espenak, F (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,PLANETARY SYST BRANCH,CODE 693,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU OBSERVATORY PI OXFORDSHIRE PA RUTHERFORD APPLETON LAB, CHILTON DIDCOT, OXFORDSHIRE, ENGLAND OX11 OQX SN 0029-7704 J9 OBSERVATORY JI Observatory PD DEC PY 1995 VL 115 IS 1129 BP 328 EP 329 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TL263 UT WOS:A1995TL26300008 ER PT J AU Drueding, TW Fawcett, SC Wilson, SR Bifano, TG AF Drueding, TW Fawcett, SC Wilson, SR Bifano, TG TI Ion beam figuring of small optical components SO OPTICAL ENGINEERING LA English DT Article DE ion figuring; optical fabrication AB Ion beam figuring provides a highly deterministic method for the final precision figuring of optical components with advantages over conventional methods, The process involves bombarding a component with a stable beam of accelerated particles that selectively removes material from the surface. Figure corrections are achieved by rastering the fixed-current beam across the workpiece at appropriate, time-varying velocities, Unlike conventional methods, ion figuring is a noncontact technique and thus avoids such problems as edge rolloff effects, tool wear, and force loading of the workpiece. This work is directed toward the development of the precision ion machining system at NASA's Marshall Space Flight Center, This system is designed for processing small (approximate to 10-cm diam) optical components. Initial experiments were successful in figuring 8-cm-diam fused silica and chemical-vapor-deposited SIC samples. The experiments, procedures, and results of figuring the sample workpieces to shallow spherical, parabolic (concave and convex), and non-axially-symmetric shapes are discussed. Several difficulties and limitations encountered with the current system are discussed, The use of a l-cm aperture for making finer corrections on optical components is also reported. C1 SANDIA SYST INC,ALBUQUERQUE,NM 87107. NASA,OPT FABRICAT BRANCH,MARSHALL SPACE FLIGHT CTR,AL 35812. RP Drueding, TW (reprint author), BOSTON UNIV,COLL ENGN,DEPT AEROSP & MECH ENGN,BOSTON,MA 02215, USA. RI Bifano, Thomas/E-6412-2013 OI Bifano, Thomas/0000-0003-4952-2515 NR 13 TC 40 Z9 41 U1 1 U2 7 PU SOC PHOTO-OPT INSTRUM ENG PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD DEC PY 1995 VL 34 IS 12 BP 3565 EP 3571 DI 10.1117/12.215648 PG 7 WC Optics SC Optics GA TK812 UT WOS:A1995TK81200030 ER PT J AU OPILA, EJ JACOBSON, NS AF OPILA, EJ JACOBSON, NS TI SIO(G) FORMATION FROM SIC IN MIXED OXIDIZING-REDUCING GASES SO OXIDATION OF METALS LA English DT Article DE SIC; SIO; ACTIVE OXIDATION; OXIDATION-REDUCTION; KINETIC MODELING ID DEPOSITED SILICON-CARBIDE; TEMPERATURE ACTIVE OXIDATION; PASSIVE TRANSITION; ATMOSPHERE; ENVIRONMENTS; CERAMICS; KINETICS; OXYGEN AB The formation of SiO(g) from SiC by either active oxidation or an oxidation-reduction process is discussed. The Wagner criterion for the transition from active to passive oxidation is generalized for any oxidant. Kinetic modeling of both active oxidation and oxidation-reduction is described. C1 CLEVELAND STATE UNIV,CLEVELAND,OH 44115. RP OPILA, EJ (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. RI Jacobson, Nathan/A-9411-2009 NR 26 TC 28 Z9 28 U1 0 U2 5 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0030-770X J9 OXID MET JI Oxid. Met. PD DEC PY 1995 VL 44 IS 5-6 BP 527 EP 544 DI 10.1007/BF01051042 PG 18 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA TE770 UT WOS:A1995TE77000004 ER PT J AU KWOK, R BALTZER, T AF KWOK, R BALTZER, T TI THE GEOPHYSICAL PROCESSOR SYSTEM AT THE ALASKA-SAR-FACILITY SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article AB The Geophysical Processor System (GPS), installed at the Alaska SAR Facility, is utilized for the routine conversion of SAR image data to geophysical data products. It is currently processing data acquired by the European ERS-1 (ERS-1) and Japanese ERS-1 (JERS-1) Synthetic Aperture Radars (SAR). The system is capable of extracting sea ice motion vectors, estimating the fraction of several ice types, and detecting ocean waves in SAR data. It was designed for automated operation, an important requirement of such systems dedicated to the routine conversion of imagery from high data rate sensors into geophysical products. Here, we give an overview of the system and discuss the features which were implemented to provide an integrated capability for supporting automated geophysical analysis of SAR image data. C1 VEXCEL CORP,BOULDER,CO 80301. RP KWOK, R (reprint author), CALTECH,JET PROP LAB,MS 300-235,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 7 TC 3 Z9 3 U1 0 U2 2 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD DEC PY 1995 VL 61 IS 12 BP 1445 EP 1453 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA TH678 UT WOS:A1995TH67800002 ER PT J AU JOSLIN, RD GROSCH, CE AF JOSLIN, RD GROSCH, CE TI GROWTH-CHARACTERISTICS DOWNSTREAM OF A SHALLOW BUMP - COMPUTATION AND EXPERIMENT SO PHYSICS OF FLUIDS LA English DT Article ID SIMULATION AB Measurements of the velocity field created by a shallow bump on a wall revealed that an energy peak in the spanwise spectrum associated with the driver decays and an initially small-amplitude secondary mode rapidly grows with distance downstream of the bump. Linear theories could not provide an explanation for this growing mode. The present Navier-Stokes simulation replicates and confirms the experimental results. Insight into the structure of the flow was obtained from a study of the results of the calculations and is presented. (C) 1995 American Institute of Physics. C1 OLD DOMINION UNIV,NORFOLK,VA 23529. RP JOSLIN, RD (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 9 TC 22 Z9 22 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD DEC PY 1995 VL 7 IS 12 BP 3042 EP 3047 DI 10.1063/1.868680 PG 6 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA TG810 UT WOS:A1995TG81000013 ER PT J AU Encrenaz, T Bezard, B Crovisier, J Coustenis, A Lellouch, E Gulkis, S Atreya, SK AF Encrenaz, T Bezard, B Crovisier, J Coustenis, A Lellouch, E Gulkis, S Atreya, SK TI Detectability of molecular species in planetary and satellite atmospheres from their rotational transitions SO PLANETARY AND SPACE SCIENCE LA English DT Article ID CARBON-MONOXIDE; HELIUM ABUNDANCE; VOYAGER MEASUREMENTS; INFRARED-SPECTRA; GLOBAL DISTRIBUTION; MICROWAVE DETECTION; MARTIAN ATMOSPHERE; MARS ATMOSPHERE; IOS ATMOSPHERE; VENUS AB High-resolution spectroscopy in the millimeter and submillimeter range has made significant contributions to the study of chemical composition and thermal structure of planetary and satellite atmospheres. This field of research is expected to make considerable progress in the future, from both ground-based and space experiments, with the availability of heterodyne receivers at frequencies up to 1 THz, and with the development of space missions devoted to the exploration of the far-infrared and submillimeter range. A compilation of guidelines for searching molecular species in planetary atmospheres through their rotational transitions, from the millimeter to the fara infrared range (100 mu m) is presented. These transitions are specified, and the corresponding synthetic spectra shown, or detectability limits are estimated. Several observational scenarios are considered, (1) ground-based heterodyne observations (such as those with IRAM, CSO, JCMT); (2) space heterodyne observations with a 3 m antenna (such as that on the European FIRST space mission); (3) Fabry-Perot spectroscopic observations from the ground and from space (such as the ISO and FIRST space missions). All planets (except Mercury) and the three satellites surrounded by an atmosphere, Titan, Triton and Io, are considered. The main results of this compilation can be summarized as follows. In addition to previously detected molecules, several species appear as promising candidates for detection in the far-infrared to millimeter spectral range. For ground-based heterodyne observations, they include : HCl, O-3 and SO on Venus; HCl, O-3, H2O2 and NO on Mars; HCl in the giant planets; SO on Io. For space observations, they are: O-2 on Venus and Mars (provided Venus is observable with FIRST), H2O in Saturn and Titan (with ISO and FIRST); HD, HCl and other halides in the giant planets (ISO). In the case of heterodyne observations, detectability limits are also indicated. They typically correspond to mixing ratios in the range 10(-8)-10(-10), depending upon the strength of the observed transition. It should be noted that a 30 m antenna operating at 230 GHz remains very competitive, especially for small objects (e.g. Io) with large dilution factors. Heterodyne observations of Triton and Pluto appear beyond the limit of detection. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. RP Encrenaz, T (reprint author), OBSERV PARIS, F-92195 MEUDON, FRANCE. NR 92 TC 21 Z9 21 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 1995 VL 43 IS 12 BP 1485 EP 1516 DI 10.1016/0032-0633(95)00064-X PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TQ127 UT WOS:A1995TQ12700001 ER PT J AU Mottola, S Sears, WD Erikson, A Harris, AW Young, JW Hahn, G Dahlgren, M Mueller, BEA Owen, B GilHutton, R Licandro, J Barucci, MA Angeli, C Neukum, G Lagerkvist, CI Lahulla, JF AF Mottola, S Sears, WD Erikson, A Harris, AW Young, JW Hahn, G Dahlgren, M Mueller, BEA Owen, B GilHutton, R Licandro, J Barucci, MA Angeli, C Neukum, G Lagerkvist, CI Lahulla, JF TI The slow rotation of 253 Mathilde SO PLANETARY AND SPACE SCIENCE LA English DT Article ID GALILEO PHYSICAL MODEL AB CCD photometry of the NEAR mission fly-by target 253 Mathilde is presented. Measurements taken during 52 nights of observations, from February to June 1995, allow a rotation period of 17.406 +/- 0.010 days and a lightcurve amplitude of 0.45 +/- 0.02 mag to be determined. A B-V color index of 0.67 +/- 0.02 and V-R of 0.35 +/- 0.02 are measured, which are compatible with C-type membership. The determination of the phase relation results in H = 10.28 +/- 0.03 and G = 0.12 +/- 0.06. Indications that the lightcurve is not strictly singly-periodic are found. A power-spectrum analysis detects a secondary frequency f(2) = 0.0322 +/- 0.0010 d(-1), which is interpreted as evidence for a complex rotation state. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. ASTRON OBSERV,S-75120 UPPSALA,SWEDEN. NATL OPT ASTRON OBSERV,TUCSON,AZ 85719. OBSERV PARIS,F-92195 MEUDON,FRANCE. YALE SO OBS,RA-5407 MARQUESADO,SAN JUAN,ARGENTINA. OBSERV ASTR FELIX AGUILAR,RA-5407 MARQUESADO,SAN JUAN,ARGENTINA. FAC CIENCIAS,DEPT ASTRON,MONTEVIDEO 11200,URUGUAY. OBSERV ASTRON ALFONSO XII,E-28014 MADRID,SPAIN. RP Mottola, S (reprint author), DLR,INST PLANETARY EXPLORAT,RUDOWER CHAUSSEE 5,D-12489 BERLIN,GERMANY. NR 14 TC 40 Z9 40 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 1995 VL 43 IS 12 BP 1609 EP 1613 DI 10.1016/0032-0633(95)00127-1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TQ127 UT WOS:A1995TQ12700010 ER PT J AU KRAEMER, SK AF KRAEMER, SK TI HISTORY OF ROCKETRY AND ASTRONAUTICS - CORNETT,LH SO PUBLIC HISTORIAN LA English DT Book Review RP KRAEMER, SK (reprint author), NASA,WASHINGTON,DC 20546, USA. NR 1 TC 0 Z9 0 U1 2 U2 2 PU UNIV CALIF PRESS PI BERKELEY PA JOURNALS DEPT 2120 BERKELEY WAY, BERKELEY, CA 94720 SN 0272-3433 J9 PUBL HISTORIAN JI Public Hist. PD WIN PY 1995 VL 17 IS 1 BP 111 EP 113 PG 3 WC History SC History GA QH060 UT WOS:A1995QH06000026 ER PT J AU KRAEMER, SK AF KRAEMER, SK TI HISTORY OF ROCKETRY AND ASTRONAUTICS - CROUCH,TD, SPENCER,AM SO PUBLIC HISTORIAN LA English DT Book Review RP KRAEMER, SK (reprint author), NASA,WASHINGTON,DC 20546, USA. NR 1 TC 0 Z9 0 U1 2 U2 2 PU UNIV CALIF PRESS PI BERKELEY PA JOURNALS DEPT 2120 BERKELEY WAY, BERKELEY, CA 94720 SN 0272-3433 J9 PUBL HISTORIAN JI Public Hist. PD WIN PY 1995 VL 17 IS 1 BP 111 EP 113 PG 3 WC History SC History GA QH060 UT WOS:A1995QH06000025 ER PT J AU Nemiroff, RJ AF Nemiroff, RJ TI The 75th anniversary astronomical debate on the distance scale to gamma-ray bursts: An introduction SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Editorial Material AB Seventy-five years ago, in April 1920, two of the leading astronomers of the first half of the twentieth century argued over the Scale of the Universe. In April 1995, in the same auditorium, two of the leading astronomers of the second half of the twentieth century argued over the Distance Scale to Gamma Ray Bursts. The text of the presented lectures and arguments are recreated in the following papers. It is hoped that these papers will stand as educational tools for those wishing to know the logic behind the arguments of the great gamma-ray burst controversy. These papers may also provide a clue as to how scientists think. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Nemiroff, RJ (reprint author), GEORGE MASON UNIV,INST CSI,FAIRFAX,VA 22030, USA. NR 1 TC 6 Z9 6 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD DEC PY 1995 VL 107 IS 718 BP 1131 EP 1132 DI 10.1086/133670 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK685 UT WOS:A1995TK68500001 ER PT J AU Fishman, GJ AF Fishman, GJ TI Gamma-ray bursts: An overview SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article AB A history and overview of the observed properties of gamma-ray bursts are presented. The phenomenon of gamma-ray bursts is without precedent in astronomy, having no observed property that would be a direct indicator of their distance and no counterpart object in another wavelength region. Their brief, random appearance only in the gamma-ray region has made their study difficult. The observed time profiles, spectral properties, and durations of gamma-ray bursts cover a wide range. All proposed models for their origin must be considered speculative. It is humbling to think that even after 25 years since their discovery, the distance scale of gamma-ray bursts is still very much debatable. RP Fishman, GJ (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,CODE ES-81,HUNTSVILLE,AL 35812, USA. NR 27 TC 20 Z9 20 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD DEC PY 1995 VL 107 IS 718 BP 1145 EP 1151 DI 10.1086/133672 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TK685 UT WOS:A1995TK68500003 ER PT J AU Pang, KD Yau, K Chou, HH AF Pang, KD Yau, K Chou, HH TI The earth's palaeorotation, postglacial rebound and lower mantle viscosity from analysis of ancient Chinese eclipse records SO PURE AND APPLIED GEOPHYSICS LA English DT Article; Proceedings Paper CT IUTAM/IASPEI Symposium on Mechanics Problems in Geodynamics CY SEP 05-09, 1994 CL BEIJING, PEOPLES R CHINA SP IUTAM, IASPEI ID ROTATION; LAGEOS; CONSTRAINTS AB Of the forces changing the Earth's rotation, tidal braking and postglacial rebound predominate at a timescale greater than or equal to 10(2)yr (HIDE and DICKEY, 1991; DICKEY, 1992). Analysis of ancient eclipse records has given values for the clock error BT and the time derivative of the Earth's dynamic oblateness J(2) for the past 3,300 yr. Since Delta T = AT - UT = ct(2), where AT is Atomic (cesium clock) Time, UT is Universal (Earth rotation) Time, and t is the number of centuries before 1800, the oldest data have the most weight. Sunrise and sunset eclipses are especially valuable, as they can be retrospectively timed. The Bamboo Annals, entombed in 299 B.C. and unearthed in A.D. 281, states that ''in the first year of King Yi of the Western Zhou dynasty. the day dawned twice at Zheng (34.5 degrees N, 109.8 degrees E).'' Kaiyuan zhanjing (Siddhartha, A.D. 724) cites this passage and adds that ''in the 2nd (actually 12th) year of Sheng Ping reign period of King Shang (actually King Xi) the day began twice at Zheng.'' Matching these records with the April 21, 899 B.C. and April 4, A.D. 368 sunrise eclipses (Oppolzer eclipse Nos. 732 and 3747) gave Delta T values of 5.8 +/- 0.15 and 1.7 +/- 0.1 hr, respectively. The recurrence of a central solar eclipse at the same site under almost identical circumstances accurately links up an ancient Delta T value with a more precise medieval one, and makes the statistics of such early data more robust. The brightness changes for the magnitudes 0.95-0.97 and 0.991-0.998 eclipses were greater than those for the January 4, 1992 ''double sunset'' over Southern California, U.S.A. (magnitude 0.91-0.92). David H. Levy noted that ''...as annularity ended. Sunset had come and gone, but the sky began to brighten not darken. For almost 15 minutes it continued to brighten until the onrushing shadow of Earth took over and darkness fell again...'' (Sky Telesc. 83, 694). We have analyzed even earlier records from the Shang dynasty. Six solar eclipse records have been identified among 160,000 oracle bones unearthed from the Shang dynasty capital Anyang (36.1 degrees N, 114.3 degrees E). Four of the 12th-century-B.C. inscriptions have cyclic days of 18, 42, 17 and 25. The Chinese 60-day cycle is like our week in design, and has been in continuous use from time immemorial. These records have been uniquely matched to the sunrise eclipses of June 7, 1172 B.C. and October 31, 1161 B.C., and sunset eclipses of October 21, 1198 B.C. and June 27, 1163 B.C., respectively. Using visibility constraints on the rising and setting eclipsed Sun from Anyang we have derived upper or lower limits on Delta T. Three of them duster around 7 hr 10 min, consistent with a Delta T of 7 hr 20 min, from the analysis of a record of the June 5, 1302 B.C. total solar eclipse, which states that ''three flames ate the Sun, big stars were seen.'' Analysis of our data gave an equation of best-fit of Delta T=(30 +/- 2.5)t(2), for the secular lunar acceleration rate n(moon) = -26 ''/cen(2) (WILLIAMS ei al., 1992). From this we derived an omega/omega of -(19 +/- 1.6) x 10(-11)/yr, where omega is the angular velocity of the Earth's rotation. Subtracting a tidal omega/omega of -27.8 x 10(-11)/yr(LAMBECK, 1980) gave a nontidal omega/omega of (9 +/- 1.6) x 10(-11)/yr, which is equivalent to a J(2) of -(4.5 +/- 0.8) x 10(-11)/yr. The average J(2) for the past 3,300 yr is larger than the present J(2) from satellite laser ranging, -3 x 10(-11)/yr (CHENG et al., 1989), as expected. Both J(2) values are consistent with postglacial rebound from an upper mantle of viscosity 10(21) Pa s, and a lower mantle of viscosity (2-4) x 10(21) Pa s, deformed by Pleistocene ice sheet loading (PELTIER, 1985). Our mantle viscosity values are consistent with those from the analyses of free air gravity anomalies and relative sea-level variations (MITROVICA and PELTIER, 1991, 1992). Accurate values of the mantle viscosity are critical to our understanding of thermal convection patterns, that are responsible for plate tectonics (PELTIER, 1986). Finally, the bounceback to its less oblate interglacial shape makes the Earth spin faster, overcoming a third of the tidal braking by the Moon and Sun. The net effect has been lengthening the day by 1.64 +/- 0.14 msec/cen. C1 UNIV CALIF LOS ANGELES,DEPT E ASIAN LANGUAGES & CULTURES,LOS ANGELES,CA 90024. RP Pang, KD (reprint author), CALTECH,JET PROP LAB,M-S 230-101,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 82 TC 6 Z9 7 U1 1 U2 1 PU BIRKHAUSER VERLAG AG PI BASEL PA PO BOX 133 KLOSTERBERG 23, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD DEC PY 1995 VL 145 IS 3-4 BP 459 EP 485 DI 10.1007/BF00879584 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TT006 UT WOS:A1995TT00600005 ER PT J AU Choudhury, BJ DiGirolamo, NE AF Choudhury, BJ DiGirolamo, NE TI Quantifying the effect of emissivity on the relations between AVHRR split window temperature difference and atmospheric precipitable water over land surfaces SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID HIGH-RESOLUTION RADIOMETER; VAPOR AB The effect emissivity on the relations between the NOAA-9 AVHRR infrared split window temperature difference (Delta T = difference of brightness of temperatures for 10.1-11.5 mu m and 11.2-12.6 Delta m bands) and atmospheric precipitable water (W), namely, Delta T = alpha + beta W and W = alpha' + beta' Delta T, is quantified in terms of red reflectance (0.55-0.72 mu m) observed by the AVHRR. Two years (1987 and 1988) of AVHRR and radiosonde observations at 44 globally distributed land surface locations have been used in the analysis. Predictions of a radiative transfer model are tested using these observations, which indicate possible discrepancies between the predicted and the observed results. Estimates of 10.1-11.5 mu m band emissivity have been made by interpreting the intercept of Delta T-W regression according to the theoretical predictions, and these emissivities were found to be linearly related to the red reflectance. Precipitable water estimated from the observed Delta T and red reflectance (by the AVHRR) for the two years at 11 locations over South America and Europe when compared with the observed precipitable water (from radiosonde) gave a mean absolute error of 5 mm and a bias of 4 mm, with the explained variance of 79%. Some inherent uncertainties in the data used in the present analysis have been noted. RP Choudhury, BJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HYDROL SCI BRANCH,LAB HYDROSPHER PROC,CODE 974,GREENBELT,MD 20771, USA. NR 31 TC 10 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD DEC PY 1995 VL 54 IS 3 BP 313 EP 323 DI 10.1016/0034-4257(95)00172-7 PG 11 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA TN587 UT WOS:A1995TN58700013 ER PT J AU MARCAIDE, JM ALBERDI, A ROS, E DIAMOND, P SHAPIRO, II GUIRADO, JC JONES, DL KRICHBAUM, TP MANTOVANI, F PRESTON, RA RIUS, A SCHILIZZI, RT TRIGILIO, C WHITNEY, AR WITZEL, A AF MARCAIDE, JM ALBERDI, A ROS, E DIAMOND, P SHAPIRO, II GUIRADO, JC JONES, DL KRICHBAUM, TP MANTOVANI, F PRESTON, RA RIUS, A SCHILIZZI, RT TRIGILIO, C WHITNEY, AR WITZEL, A TI EXPANSION OF SN 1993J SO SCIENCE LA English DT Article ID RADIO; SUPERNOVA; MODEL; EMISSION; SYSTEM AB A sequence of images from very long baseline interferometry shows that the young radio supernova SN 1993J is expanding with circular symmetry. However, the circularly symmetric images show emission asymmetries. A scenario in which freely expanding supernova ejecta shock mostly isotropic circumstellar material is strongly favored. The sequence of images constitutes the first ''movie'' of a radio supernova. C1 INTA,ASTROFIS ESPACIAL & FIS FUNDAMENTAL,E-28080 MADRID,SPAIN. CSIC,INST ASTROFIS ANDALUCIA,E-18080 GRANADA,SPAIN. NATL RADIO ASTRON OBSERV,SOCORRO,NM 87801. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. CALTECH,JET PROP LAB,PASADENA,CA 91109. MAX PLANCK INST RADIOASTRON,D-50131 BONN,GERMANY. CNR,IST RADIOASTRON,I-40129 BOLOGNA,ITALY. CSIC,CTR ESTUDIOS AVANCATS,E-17300 BLANES,SPAIN. JOINT INST VLBI EUROPE,7990 AA DWINGELOO,NETHERLANDS. LEIDEN OBSERV,2300 RA LEIDEN,NETHERLANDS. CNR,IST RADIOASTRON,NOTO,ITALY. MIT,HAYSTACK OBSERV,WESTFORD,MA 01886. RP MARCAIDE, JM (reprint author), UNIV VALENCIA,DEPT ASTRON,E-46100 BURJASSOT,SPAIN. OI Ros, Eduardo/0000-0001-9503-4892 NR 34 TC 46 Z9 46 U1 0 U2 4 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 1 PY 1995 VL 270 IS 5241 BP 1475 EP 1478 DI 10.1126/science.270.5241.1475 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TH375 UT WOS:A1995TH37500032 ER PT J AU JOHNSON, TV AF JOHNSON, TV TI THE GALILEO MISSION SO SCIENTIFIC AMERICAN LA English DT Article RP JOHNSON, TV (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91125, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 SN 0036-8733 J9 SCI AM JI Sci.Am. PD DEC PY 1995 VL 273 IS 6 BP 44 EP 51 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TF384 UT WOS:A1995TF38400030 ER PT J AU Brumback, RA Feeback, DL Leech, RW AF Brumback, RA Feeback, DL Leech, RW TI Rhabdomyolysis following electrical injury SO SEMINARS IN NEUROLOGY LA English DT Article ID SKELETAL-MUSCLE; EXERCISE; MYOGLOBINURIA; DEFICIENCY; MECHANISMS; MEMBRANES C1 UNIV OKLAHOMA,HLTH SCI CTR,DEPT NEUROL,OKLAHOMA CITY,OK 73190. UNIV OKLAHOMA,HLTH SCI CTR,DEPT PEDIAT,OKLAHOMA CITY,OK 73190. UNIV OKLAHOMA,HLTH SCI CTR,DEPT PSYCHIAT & BEHAV SCI,OKLAHOMA CITY,OK 73190. UNIV OKLAHOMA,HLTH SCI CTR,NEUROPATHOL SECT,OKLAHOMA CITY,OK 73190. VET AFFAIRS MED CTR,OKLAHOMA CITY,OK 73104. NASA,JOHNSON SPACE CTR,DIV MED SCI,MED OPERAT & RES BRANCH,MUSCLE RES LAB,HOUSTON,TX. RP Brumback, RA (reprint author), UNIV OKLAHOMA,HLTH SCI CTR,DEPT PATHOL,BMSB 451,940 STANTON L YOUNG BLVD,BOX 26901,OKLAHOMA CITY,OK 73190, USA. RI Brumback, Roger/A-2404-2008 NR 22 TC 17 Z9 17 U1 0 U2 0 PU THIEME MEDICAL PUBL INC PI NEW YORK PA 381 PARK AVE SOUTH, NEW YORK, NY 10016 SN 0271-8235 J9 SEMIN NEUROL JI Semin. Neurol. PD DEC PY 1995 VL 15 IS 4 BP 329 EP 334 DI 10.1055/s-2008-1041040 PG 6 WC Clinical Neurology SC Neurosciences & Neurology GA TK986 UT WOS:A1995TK98600002 PM 8848649 ER PT J AU Domingo, V Fleck, B Poland, AI AF Domingo, V Fleck, B Poland, AI TI The SOHO mission: An overview SO SOLAR PHYSICS LA English DT Article DE SOHO; solar interior; solar corona; solar wind ID 5-MINUTE OSCILLATION AB The Solar and Heliospheric Observatory (SOHO) is a space mission that forms part of the Solar-Terrestrial Science Program (STSP), developed in a collaborative effort by the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA). The STSP constitutes the first ''cornerstone'' of ESA's long-term programme known as ''Space Science - Horizon 2000''. The principal scientific objectives of the SOHO mission are a) to reach a better understanding of the structure and dynamics of the solar interior using techniques of helioseismology, and b) to gain better insight into the physical processes that form and heat the Sun's corona, maintain it and give rise to its acceleration into the solar wind. To achieve these goals, SOHO carries a payload consisting of 12 sets of complementary instruments. SOHO is a three-axis stabilized spacecraft with a total mass of 1850 kg; 1150 W of power will be provided by the solar panels. The payload weighs about 640 kg and will consume 450 W in orbit. SOHO will be launched by an ATLAS II-AS and will be placed in a halo orbit around the Sun-Earth L1 Lagrangian point where it will be continuously pointing to Sun centre with an accuracy of 10 arcsec. Pointing stability will be better than 1 arcsec over 15 min intervals. The SOHO payload produces a continuous science data stream of 40 kbits/s which will be increased by 160 kbits/s whenever the solar oscillations imaging instrument is operated in its high-rate mode. Telemetry will be received by NASA's Deep Space Network (DSN). Planning, coordination and operation of the spacecraft and the scientific payload will be conducted from the Experiment Operations Facility (EOF) at NASA's Goddard Space Flight Center (GSFC). C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. RP Domingo, V (reprint author), EUROPEAN SPACE AGCY,ESTEC,DEPT SPACE SCI,POB 299,2200 AG NOORDWIJK,NETHERLANDS. RI Fleck, Bernhard/C-9520-2012 NR 23 TC 624 Z9 631 U1 11 U2 41 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1995 VL 162 IS 1-2 BP 1 EP 37 DI 10.1007/BF00733425 PG 37 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TM503 UT WOS:A1995TM50300003 ER PT J AU StCyr, OC SanchezDuarte, L Martens, PCH Gurman, JB Larduinat, E AF StCyr, OC SanchezDuarte, L Martens, PCH Gurman, JB Larduinat, E TI SOHO ground segment, science operations, and data products SO SOLAR PHYSICS LA English DT Article AB We describe the ground segment, pre-launch operations concepts, and data products supporting the SOHO mission. Our goal is threefold: first, we provide a historical view of the design and development of the systems described here, as a background perspective to those who will use the system and those who may build such systems for future missions. Second, because we hope that many researchers from the solar and space physics communities will visit these facilities during the mission, we provide an overview for the benefit of the end-user. We anticipate that visitors to GSFC may plan observations for one or more of SOHO's complement of instruments, and such researchers may use the facilities to analyze data gathered by the SOHO instruments. Third, we present the working plan for investigators with groundbased or other spacebased instruments to collaborate with SOHO. C1 ESA,DEPT SPACE SCI,SOLAR SYST DIV,ALBUQUERQUE,NM. RP StCyr, OC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ALLIEDSIGNAL TECH SERV CORP,ASTRON & SOLAR PHYS LAB,WASHINGTON,DC, USA. NR 7 TC 6 Z9 6 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1995 VL 162 IS 1-2 BP 39 EP 59 DI 10.1007/BF00733426 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TM503 UT WOS:A1995TM50300004 ER PT J AU Frohlich, C Romero, J Roth, H Wehrli, C Andersen, BN Appourchaux, T Domingo, V Telljohann, U Berthomieu, G Delache, P Provost, J Toutain, T Crommelynck, DA Chevalier, A Fichot, A Dappen, W Gough, D Hoeksema, T Jimenez, A Gomez, MF Herreros, JM Cortes, TR Jones, AR Pap, JM Willson, RC AF Frohlich, C Romero, J Roth, H Wehrli, C Andersen, BN Appourchaux, T Domingo, V Telljohann, U Berthomieu, G Delache, P Provost, J Toutain, T Crommelynck, DA Chevalier, A Fichot, A Dappen, W Gough, D Hoeksema, T Jimenez, A Gomez, MF Herreros, JM Cortes, TR Jones, AR Pap, JM Willson, RC TI VIRGO: Experiment for helioseismology and solar irradiance monitoring SO SOLAR PHYSICS LA English DT Article DE helioseismology; total solar irradiance; spectral solar irradiance; low resolution solar radiance; SOHO mission ID MODES; OSCILLATIONS; LUMINOSITY; SCALE AB The scientific objective of the VIRGO experiment (Variability of solar IRradiance and Gravity Oscillations) is to determine the characteristics of pressure and internal gravity oscillations by observing irradiance and radiance variations, to measure the solar total and spectral irradiance and to quantify their variability over periods of days to the duration of the mission. With these data helioseismological methods can be used to probe the solar interior. Certain characteristics of convection and its interaction with magnetic fields, related to, for example, activity, will be studied from the results of the irradiance monitoring and from the comparison of amplitudes and phases of the oscillations as manifest in brightness from VIRGO, in velocity from GOLF, and in both velocity and continuum intensity from SOI/MDI. The VIRGO experiment contains two different active-cavity radiometers for monitoring the solar 'constant', two three-channel sunphotometers (SPM) for the measurement of the spectral irradiance at 402, 500 and 862 nm, and a low-resolution imager (LOI) with 12 pixels, for the measurement of the radiance distribution over the solar disk at 500 nm. In this paper the scientific objectives of VIRGO are presented, the instruments and the data acquisition and control system are described in detail, and their measured performance is given. C1 NORWEGIAN SPACE CTR, N-0309 OSLO 3, NORWAY. ESTEC, DEPT SPACE SCI, 2200 AG NOORDWIJK, NETHERLANDS. OBSERV COTE AZUR, DEPT CASSINI, URA CNRS 1362, F-06304 NICE 4, FRANCE. INST ROYAL METEOROL BELGIQUE, B-1180 BRUSSELS, BELGIUM. UNIV SO CALIF, DEPT ASTRON, LOS ANGELES, CA 90089 USA. UNIV CAMBRIDGE, INST ASTRON, CAMBRIDGE CB3 0HA, ENGLAND. UNIV CAMBRIDGE, DEPT APPL MATH & THEORET PHYS, CAMBRIDGE CB3 0HA, ENGLAND. STANFORD UNIV, CTR SPACE SCI & ASTROPHYS, STANFORD, CA 94305 USA. UNIV LA LAGUNA, INST ASTROFIS CANARIAS, E-38071 LA LAGUNA, SPAIN. NATL OPT ASTRON OBSERV, TUCSON, AZ 85726 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. RP Frohlich, C (reprint author), WORLD RADIAT CTR, PHYS METEOROL OBSERV DAVOS, CH-7260 DAVOS, SWITZERLAND. NR 36 TC 191 Z9 192 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1995 VL 162 IS 1-2 BP 101 EP 128 DI 10.1007/BF00733428 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TM503 UT WOS:A1995TM50300006 ER PT J AU Wilhelm, K Curdt, W Marsch, E Schuhle, U Lemaire, P Gabriel, A Vial, JC Grewing, M Huber, MCE Jordan, SD Poland, AI Thomas, RJ Kuhne, M Timothy, JG Hassler, DM Siegmund, OHW AF Wilhelm, K Curdt, W Marsch, E Schuhle, U Lemaire, P Gabriel, A Vial, JC Grewing, M Huber, MCE Jordan, SD Poland, AI Thomas, RJ Kuhne, M Timothy, JG Hassler, DM Siegmund, OHW TI SUMER - Solar ultraviolet measurements of emitted radiation SO SOLAR PHYSICS LA English DT Article DE solar EUV emission lines; coronal heating; solar wind acceleration; EUV spectrometer ID MICROCHANNEL PLATES; WIND AB The instrument SUMER - Solar Ultraviolet Measurements of Emitted Radiation is designed to investigate structures and associated dynamical processes occurring in the solar atmosphere, from the chromosphere through the transition region to the inner corona, over a temperature range from 10(4) to 2 x 10(6) K and above. These observations will permit detailed spectroscopic diagnostics of plasma densities and temperatures in many solar features, and will support penetrating studies of underlying physical processes, including plasma flows, turbulence and wave motions, diffusion transport processes, events associated with solar magnetic activity, atmospheric heating, and solar wind acceleration in the inner corona. Specifically, SUMER will measure profiles and intensities of EUV lines; determine Doppler shifts and line broadenings with high accuracy; provide stigmatic images of the Sun in the EUV with high spatial, spectral, and temporal resolution; and obtain monochromatic maps of the full Sun and the inner corona or selected areas thereof. SUMER will be flown on the Solar and Heliospheric Observatory (SOHO), scheduled for launch in November, 1995. This paper has been written to familiarize solar physicists with SUMER and to demonstrate some command procedures for achieving certain scientific observations. C1 UNIV PARIS 11, INST ASTROPHYS SPATIALE, UNITE MIXTE CNRS, F-91405 ORSAY, FRANCE. ASTRON INST, D-72076 TUBINGEN, GERMANY. EUROPEAN SPACE AGCY, ESTEC, DEPT SPACE SCI, 2200 AG NOORDWIJK, NETHERLANDS. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD USA. PHYS TECH BUNDESANSTALT, D-10587 BERLIN, GERMANY. UNIV NEW BRUNSWICK, FREDERICTON, NB, CANADA. NCAR, HIGH ALTITUDE OBSERV, BOULDER, CO USA. UNIV CALIF BERKELEY, SSL, BERKELEY, CA USA. RP Wilhelm, K (reprint author), MAX PLANCK INST AERON, D-37189 KATLENBURG DUHM, GERMANY. NR 19 TC 701 Z9 709 U1 2 U2 21 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1995 VL 162 IS 1-2 BP 189 EP 231 DI 10.1007/BF00733430 PG 43 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TM503 UT WOS:A1995TM50300008 ER PT J AU Harrison, RA Sawyer, EC Carter, MK Cruise, AM Cutler, RM Fludra, A Hayes, RW Kent, BJ Lang, J Parker, DJ Payne, J Pike, CD Peskett, SC Richards, AG Culhane, JL Norman, K Breeveld, AA Breeveld, ER ALJanabi, KF Mccalden, AJ Parkinson, JH Self, DG Thomas, PD Poland, AI Thomas, RJ Thompson, WT KjeldsethMoe, O Brekke, P Karud, J Maltby, P Aschenbach, B Brauninger, H Kuhne, M Hollandt, J Siegmund, OHW Huber, MCE Gabriel, AH Mason, HE Bromage, BJI AF Harrison, RA Sawyer, EC Carter, MK Cruise, AM Cutler, RM Fludra, A Hayes, RW Kent, BJ Lang, J Parker, DJ Payne, J Pike, CD Peskett, SC Richards, AG Culhane, JL Norman, K Breeveld, AA Breeveld, ER ALJanabi, KF Mccalden, AJ Parkinson, JH Self, DG Thomas, PD Poland, AI Thomas, RJ Thompson, WT KjeldsethMoe, O Brekke, P Karud, J Maltby, P Aschenbach, B Brauninger, H Kuhne, M Hollandt, J Siegmund, OHW Huber, MCE Gabriel, AH Mason, HE Bromage, BJI TI The coronal diagnostic spectrometer for the solar and heliospheric observatory SO SOLAR PHYSICS LA English DT Article DE solar atmosphere; extreme UV spectroscopy ID RADIANT POWER MEASUREMENTS; STORAGE RING BESSY; LINE RATIOS; WAVELENGTH RANGE; ULTRAVIOLET; IONS; SUN; NM AB The Coronal Diagnostic Spectrometer is designed to probe the solar atmosphere through the detection of spectral emission lines in the extreme ultraviolet wavelength range 150-800 Angstrom. By observing the intensities of selected lines and line profiles, we may derive temperature, density, flow and abundance information for the plasmas in the solar atmosphere. Spatial and temporal resolutions of down to a few arcseconds and seconds, respectively, allow such studies to be made within the fine-scale structure of the solar corona. Furthermore, coverage of large wavelength bands provides the capability for simultaneously observing the properties of plasmas across the wide temperature ranges of the solar atmosphere. C1 UCL, MULLARD SPACE SCI LAB, DORKING RH5 6NT, SURREY, ENGLAND. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. UNIV OSLO, INST THEORET ASTROPHYS, N-0315 OSLO, NORWAY. MAX PLANCK INST EXTRATERR PHYS, D-85748 GARCHING, GERMANY. INST BERLIN, PHYS TECH BUNDESANSTALT, W-1000 BERLIN 10, GERMANY. UNIV CALIF BERKELEY, SPACE SCI LAB, EXPTL ASTROPHYS GRP, BERKELEY, CA 94720 USA. EUROPEAN SPACE AGCY, ESTEC, DEPT SPACE SCI, 2200 AG NOORDWIJK, NETHERLANDS. UNIV PARIS 11, INST ASTROPHYS SPATIALE, F-91405 ORSAY, FRANCE. UNIV CAMBRIDGE, DEPT APPL MATH & THEORET PHYS, CAMBRIDGE CB3 9EW, ENGLAND. UNIV CENT LANCASHIRE, DEPT PHYS & ASTRON, PRESTON PR1 2HE, LANCS, ENGLAND. RP Harrison, RA (reprint author), RUTHERFORD APPLETON LAB, DEPT SPACE SCI, DIDCOT OX11 0QX, OXON, ENGLAND. RI Thompson, William/D-7376-2012; Hollandt, Jorg/A-2124-2014 NR 41 TC 565 Z9 571 U1 3 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1995 VL 162 IS 1-2 BP 233 EP 290 DI 10.1007/BF00733431 PG 58 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TM503 UT WOS:A1995TM50300009 ER PT J AU Delaboudiniere, JP Artzner, GE Brunaud, J Gabriel, AH Hochedez, JF Millier, F Song, XY Au, B Dere, KP Howard, RA Kreplin, R Michels, DJ Moses, JD Defise, JM Jamar, C Rochus, P Chauvineau, JP Marioge, JP Catura, RC Lemen, JR Shing, L Stern, RA Gurman, JB Neupert, WM Maucherat, A Clette, F Cugnon, P VanDessel, EL AF Delaboudiniere, JP Artzner, GE Brunaud, J Gabriel, AH Hochedez, JF Millier, F Song, XY Au, B Dere, KP Howard, RA Kreplin, R Michels, DJ Moses, JD Defise, JM Jamar, C Rochus, P Chauvineau, JP Marioge, JP Catura, RC Lemen, JR Shing, L Stern, RA Gurman, JB Neupert, WM Maucherat, A Clette, F Cugnon, P VanDessel, EL TI EIT: Extreme-ultraviolet imaging telescope for the SOHO mission SO SOLAR PHYSICS LA English DT Article DE solar X-rays; solar EUV; multilayer telescope ID OPTICAL-CONSTANTS; THIN-FILMS; 1216-A; 24-A AB The Extreme-ultraviolet Imaging Telescope (EIT) will provide wide-field images of the corona and transition region on the solar disc and up to 1.5 R. above the solar limb. Its normal incidence multilayer-coated optics will select spectral emission lines from Fe IX (171 Angstrom), Fe XII (195 Angstrom), Fe XV (284 Angstrom), and He II (304 Angstrom) to provide sensitive temperature diagnostics in the range from 6 x 10(4) K to 3 x 10(6) K. The telescope has a 45 x 45 arcmin field of view and 2.6 arcsec pixels which will provide approximately 5-arcsec spatial resolution. The EIT will probe the coronal plasma on a global scale, as well as the underlying cooler and turbulent atmosphere, providing the basis for comparative analyses with observations from both the ground and other SOHO instruments. This paper presents details of the EIT instrumentation, its performance and operating modes. C1 USN,RES LAB,WASHINGTON,DC 20375. CTR SPATIAL LIEGE,LIEGE,BELGIUM. INST OPT THEOR & APPL,F-91403 ORSAY,FRANCE. LOCKHEED PALO ALTO RES LABS,PALO ALTO,CA 94304. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. ASTRON SPATIALE LAB,MARSEILLE,FRANCE. OBSERV ROYAL BELGIQUE,B-1180 BRUSSELS,BELGIUM. RP Delaboudiniere, JP (reprint author), UNIV PARIS 11,INST ASTROPHYS SPATIALE,F-91405 ORSAY,FRANCE. NR 21 TC 1385 Z9 1415 U1 3 U2 22 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1995 VL 162 IS 1-2 BP 291 EP 312 DI 10.1007/BF00733432 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TM503 UT WOS:A1995TM50300010 ER PT J AU Kohl, JL Esser, R Gardner, LD Habbal, S Daigneau, PS Dennis, EF Nystrom, GU Panasyuk, A Raymond, JC Smith, PL Strachan, L VanBallegooijen, AA Noci, G Fineschi, S Romoli, M Ciaravella, A Modigliani, A Huber, MCE Antonucci, E Benna, C Giordano, S Tondello, G Nicolosi, P Naletto, G Pernechele, C Spadaro, D Poletto, G Livi, S VonderLuhe, O Geiss, J Timothy, JG Gloeckler, G Allegra, A Basile, G Brusa, R Wood, B Siegmund, OHW Fowler, W Fisher, R Jhabvala, M AF Kohl, JL Esser, R Gardner, LD Habbal, S Daigneau, PS Dennis, EF Nystrom, GU Panasyuk, A Raymond, JC Smith, PL Strachan, L VanBallegooijen, AA Noci, G Fineschi, S Romoli, M Ciaravella, A Modigliani, A Huber, MCE Antonucci, E Benna, C Giordano, S Tondello, G Nicolosi, P Naletto, G Pernechele, C Spadaro, D Poletto, G Livi, S VonderLuhe, O Geiss, J Timothy, JG Gloeckler, G Allegra, A Basile, G Brusa, R Wood, B Siegmund, OHW Fowler, W Fisher, R Jhabvala, M TI The ultraviolet coronagraph spectrometer for the solar and heliospheric observatory SO SOLAR PHYSICS LA English DT Article DE sun; solar; corona; solar wind; UV spectroscopy; UV coronagraph ID MICROCHANNEL PLATES; POLAR-REGION; TEMPERATURES; RADII; SUN AB The SOHO Ultraviolet Coronagraph Spectrometer (UVCS/SOHO) is composed of three reflecting telescopes with external and internal occultation and a spectrometer assembly consisting of two toric grating spectrometers and a visible light polarimeter. The purpose of the UVCS instrument is to provide a body of data that can be used to address a broad range of scientific questions regarding the nature of the solar corona and the generation of the solar wind. The primary scientific goals are the following: to locate and characterize the coronal source regions of the solar wind, to identify and understand the dominant physical processes that accelerate the solar wind, to understand how the coronal plasma is heated in solar wind acceleration regions, and to increase the knowledge of coronal phenomena that control the physical properties of the solar wind as determined by in situ measurements. To progress toward these goals, the UVCS will perform ultraviolet spectroscopy and visible polarimetry to be combined with plasma diagnostic analysis techniques to provide detailed empirical descriptions of the extended solar corona from the coronal base to a heliocentric height of 12 solar radii. C1 UNIV FLORENCE,I-50125 FLORENCE,ITALY. EUROPEAN SPACE AGCY,ESTEC,DEPT SPACE SCI,2200 AG NOORDWIJK,NETHERLANDS. UNIV TURIN,I-10125 TURIN,ITALY. UNIV PADUA,I-35131 PADUA,ITALY. OSSERV ASTROFIS CATANIA,I-95125 CATANIA,ITALY. OSSERV ASTROFIS ARCETRI,I-50125 FLORENCE,ITALY. MAX PLANCK INST AERON,D-37189 KATLENBURG LINDAU,GERMANY. EUROPEAN SO OBSERV,D-85748 GARCHING,GERMANY. INT SPACE SCI INST,CH-3012 BERN,SWITZERLAND. UNIV NEW BRUNSWICK,NEW BRUNSWICK,NB E3B 5A3,CANADA. UNIV MARYLAND,COLLEGE PARK,MD 20742. ALENIA SPAZIO,I-10146 TURIN,ITALY. OFFICINE GALILEO,DIV OTT & SPAZIO,I-50013 FLORENCE,ITALY. BRUSAG,CH-8712 STAFA,SWITZERLAND. OERLIKON CONTRAVES,SPACE DIV,CH-8052 ZURICH,SWITZERLAND. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. BALL CORP,ELECTROOPT & CRYOGEN DIV,BOULDER,CO 80306. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. OSSERVATORIO ASTRON PALERMO,PALERMO,ITALY. RP Kohl, JL (reprint author), HARVARD SMITHSONIAN CTR ASTROPHYS,60 GARDEN ST,CAMBRIDGE,MA 02138, USA. RI Romoli, Marco/H-6859-2012; Naletto, Giampiero/S-6329-2016; OI Naletto, Giampiero/0000-0003-2007-3138; Giordano, Silvio/0000-0002-3468-8566; pernechele, claudio/0000-0002-7752-6268 NR 31 TC 360 Z9 363 U1 1 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1995 VL 162 IS 1-2 BP 313 EP 356 DI 10.1007/BF00733433 PG 44 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TM503 UT WOS:A1995TM50300011 ER PT J AU Hovestadt, D Hilchenbach, M Burgi, A Klecker, B Laeverenz, P Scholer, M Grunwaldt, H Axford, WI Livi, S Marsch, E Wilken, B Winterhoff, HP Ipavich, FM Bedini, P Coplan, MA Galvin, AB Gloeckler, G Bochsler, P Balsiger, H Fischer, J Geiss, J Kallenbach, R Wurz, P Reiche, KU Gliem, F Judge, DL Ogawa, HS Hsieh, KC Mobius, E Lee, MA Managadze, GG Verigin, MI Neugebauer, M AF Hovestadt, D Hilchenbach, M Burgi, A Klecker, B Laeverenz, P Scholer, M Grunwaldt, H Axford, WI Livi, S Marsch, E Wilken, B Winterhoff, HP Ipavich, FM Bedini, P Coplan, MA Galvin, AB Gloeckler, G Bochsler, P Balsiger, H Fischer, J Geiss, J Kallenbach, R Wurz, P Reiche, KU Gliem, F Judge, DL Ogawa, HS Hsieh, KC Mobius, E Lee, MA Managadze, GG Verigin, MI Neugebauer, M TI CELIAS - Charge, element and isotope analysis system for SOHO SO SOLAR PHYSICS LA English DT Article DE SOHO; solar wind; solar energetic particles; composition measurements; time-of-flight spectrometer ID ABUNDANCES AB The CELIAS experiment on SOHO is designed to measure the mass, ionic charge and energy of the low and high speed solar wind, of suprathermal ions, and of low energy flare particles. Through analysis of the elemental and isotopic abundances, the ionic charge state, and the velocity distributions of ions originating in the solar atmosphere, the investigation focuses on the plasma processes on various temporal and spatial scales in the solar chromosphere, transition zone, and corona. CELIAS includes 3 mass- and charge-discriminating sensors based on the time-of-flight technique: CTOF for the elemental, charge and velocity distribution of the solar wind, MTOF for the elemental and isotopic composition of the solar wind, and STOF for the mass, charge and energy distribution of suprathermal ions. The instrument will provide detailed in situ diagnostics of the solar wind and of accelerated particles, which will complement the optical and spectroscopic investigations of the solar atmosphere on SOHO. CELIAS also contains a Solar Extreme Ultraviolet Monitor, SEM, which continuously measures the EUV flux in a wide band of 17-170 nm,and a narrow band around the 30.4 nm He II line. C1 MAX PLANCK INST AERON,D-37189 KATLENBURG DUHM,GERMANY. UNIV MARYLAND,DEPT PHYS & ASTRON,COLLEGE PK,MD 20742. UNIV MARYLAND,IPST,COLLEGE PK,MD 20742. UNIV BERN,INST PHYS,CH-3012 BERN,SWITZERLAND. TECH UNIV CAROLO WILHELMINA BRAUNSCHWEIG,INST DATENVERARBEITUNGSANLAGEN,D-38023 BRAUNSCHWEIG,GERMANY. UNIV SO CALIF,CTR SPACE SCI,LOS ANGELES,CA 90089. UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721. UNIV NEW HAMPSHIRE,EOS,DURHAM,NH 03824. INST SPACE PHYS,MOSCOW,RUSSIA. JET PROPULS LAB,PASADENA,CA 91103. RP Hovestadt, D (reprint author), MAX PLANCK INST EXTRATERR PHYS,D-85740 GARCHING,GERMANY. RI Galvin, Antoinette/A-6114-2013; OI Moebius, Eberhard/0000-0002-2745-6978 NR 14 TC 221 Z9 225 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1995 VL 162 IS 1-2 BP 441 EP 481 DI 10.1007/BF00733436 PG 41 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TM503 UT WOS:A1995TM50300014 ER PT J AU Fleck, B Domingo, V Poland, A AF Fleck, B Domingo, V Poland, A TI Preface SO SOLAR PHYSICS LA English DT Editorial Material C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. RP Fleck, B (reprint author), EUROPEAN SPACE AGCY,ESTEC,DEPT SPACE SCI,POB 299,2200 AG NOORDWIJK,NETHERLANDS. RI Fleck, Bernhard/C-9520-2012 NR 0 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 1995 VL 162 IS 1-2 BP R9 EP R9 DI 10.1007/BF00733423 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TM503 UT WOS:A1995TM50300001 ER PT J AU CONLEY, MS MEYER, RA BLOOMBERG, JJ FEEBACK, DL DUDLEY, GA AF CONLEY, MS MEYER, RA BLOOMBERG, JJ FEEBACK, DL DUDLEY, GA TI NONINVASIVE ANALYSIS OF HUMAN NECK MUSCLE FUNCTION SO SPINE LA English DT Article DE CERVICAL MUSCLES; FUNCTIONAL MAGNETIC RESONANCE IMAGING; RECRUITMENT AB Study Design. Muscle use evoked by exercise was determined by quantifying shifts in signal relaxation times of T2-weighted magnetic resonance images. Images were collected at rest and after exercise at each of two intensities (moderate and intense) for each of four head movements: 1) extension, 2) flexion, 3) rotation, and 4) lateral flexion. Objective. This study examined the intensity and pattern of neck muscle use evoked by various movements of the head. The results will help elucidate the pathophysiology, and thus methods for treating disorders of the cervical musculoskeletal system. Summary of Background Data. Exercise-induced contract shift in T2 has been shown to indicate muscle use during the activity. The noninvasive nature of magnetic resonance imaging appears to make it an ideal approach for studying the function of the complex neuromuscular system of the neck. Methods. The extent of T2 increase was examined to gauge how intensely nine different neck muscles or muscle pairs were used in seven subjects. The absolute and relative cross-sectional area of muscle showing a shift in signal relaxation was assessed to infer the pattern of use among and within individual neck muscles or muscle pairs. Results. Signal relaxation increased with exercise intensity for each hade movement. The absolute and relative cross-sectional areas of muscle showing a shift in signal relaxation also increased with exercise load. Neck muscles or muscle paors extensively used to perform each head movement were: extension-semispinalis capitis and cervicis and splenius capitis; flexion-rotation-splenius capitis, levator scapulae, scalenus, semispinalis capitis ipsilateral to the rotation, and sternocleidomastoid contralateral; and lateral flexion-sternocleidomastoid. Conclusion. The results of this study, in part, agree with the purported functions of neck muscles derived from anatomic location. This also was true for the few selected muscles that have been examined in human electromyographic studies. Neck muscle function and morphology can be studied at a detailed level using exercise-induced shifts in magnetic resonance images. C1 MICHIGAN STATE UNIV,DEPT PHYSIOL,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT RADIOL,E LANSING,MI 48824. NASA,LYNDON B JOHNSON SPACE CTR,DIV MED SCI,HOUSTON,TX 77058. RP CONLEY, MS (reprint author), UNIV GEORGIA,DEPT EXERCISE SCI,300 RIVER RD,ATHENS,GA 30602, USA. NR 0 TC 108 Z9 114 U1 0 U2 10 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQUARE, PHILADELPHIA, PA 19106 SN 0362-2436 J9 SPINE JI SPINE PD DEC 1 PY 1995 VL 20 IS 23 BP 2505 EP 2512 DI 10.1097/00007632-199512000-00009 PG 8 WC Clinical Neurology; Orthopedics SC Neurosciences & Neurology; Orthopedics GA TJ493 UT WOS:A1995TJ49300009 PM 8610245 ER PT J AU Sliney, HE Loomis, WR DellaCorte, C AF Sliney, HE Loomis, WR DellaCorte, C TI Evaluation of PS 212 coatings under boundary lubrication conditions with an ester-based oil to 300 degrees C SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 22nd International Conference on Metallurgical Coatings and Thin Films (ICMCTF 1995) CY APR 25-29, 1995 CL SAN DIEGO, CA SP Amer Vacuum Soc, Vacuum Met & Thin Films Div DE coatings; lubrication ID COMPOSITE AB High friction and wear of turbine engine components occur during high temperature excursions above the oxidation threshold of the liquid lubricant. This paper reports on research to study the use of a high temperature self lubricating coating, PS 212 for back-up lubrication in the event of failure of the liquid lubricant. Pin on disk tests were performed under dry and boundary-lubricated conditions at disk temperatures up to 300 degrees C. The liquid lubricant was a formulated polyol ester qualified under MIL L-23699. At test temperatures above the oil's thermal degradation level, the use of PS212 reduced wear, providing a back-up lubricant effect. C1 NASA, LEWIS RES CTR, CLEVELAND, OH 44135 USA. AEROSP DESIGN & FABRICAT INC, BROOKPARK, OH 44142 USA. NR 12 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC PY 1995 VL 76-77 IS 1-3 BP 407 EP 414 DI 10.1016/0257-8972(95)02565-0 PN 2 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA TM180 UT WOS:A1995TM18000005 ER PT J AU Heyd, AR Alterovitz, SA Croke, ET Wang, KL Lee, CH AF Heyd, AR Alterovitz, SA Croke, ET Wang, KL Lee, CH TI Applications of variable angle spectroscopic ellipsometry to strained SiGe alloy heterostructures SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 22nd International Conference on Metallurgical Coatings and Thin Films (ICMCTF 1995) CY APR 24-29, 1995 CL SAN DIEGO, CA SP Amer Vacuum Soc, Vacuum Met & Thin Films Div DE ellipsometry; alloys; heterostructures; silicon; germanium ID DIELECTRIC FUNCTION; TEMPERATURE-DEPENDENCE; LAYER SUPERLATTICES; GERMANIUM; SILICON AB Variable angle spectroscopic ellipsometry (VASE) has been used to characterize several SixGel-x/Ge heterostructures. First, SixGel-x/ Ge superlattice (SL) structures were characterized in terms of the layer thicknesses, composition, x, of the SixGel-x layer, and oxide thickness. High-resolution X-ray diffraction results are also presented for the SixGex-l/Ge SL structures and are shown to be in close agreement with the VASE results once strain effects are taken into account. VASE has also been used to study thick, Ge-rich SixGel-x/Ge heterostructures that have been grown on Si substrates. A stepped buffer has been deposited first in order to minimize the strain in the SixGel-x/Ge layers, VASE can be used to give a qualitative determination of the residual strain along with the thickness of all layers within the optical penetration depth from the surface. C1 HUGHES RES LABS,MALIBU,CA 90265. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. RP Heyd, AR (reprint author), NASA,LEWIS RES CTR,21000 BROOKPK RD,MS 54-5,CLEVELAND,OH 44135, USA. NR 18 TC 2 Z9 2 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD DEC 1 PY 1995 VL 270 IS 1-2 BP 91 EP 96 DI 10.1016/0040-6090(95)06848-1 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA TM187 UT WOS:A1995TM18700019 ER PT J AU Heagle, AS Miller, JE Chevone, BI Dreschel, TW Manning, WJ Cool, PMM Morrison, CL Neely, GE Rebbeck, J AF Heagle, AS Miller, JE Chevone, BI Dreschel, TW Manning, WJ Cool, PMM Morrison, CL Neely, GE Rebbeck, J TI Response of a white clover indicator system to tropospheric ozone at eight locations in the United States SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT 5th International Conference on Acidic Deposition - Science and Policy: Acid Reign 95 CY JUN 26-30, 1995 CL GOTHENBURG, SWEDEN SP Swedish Environm Protect Agcy, Swedish Environm Res Inst, Provincial Govt Goteborg, Provincial Govt Bohus Ian DE tropospheric ozone; white clover; air pollution; biomonitor ID TALL FESCUE PASTURE AB A white clover (Trifolium repens L.) system using measured biomass to indicate effective concentrations of tropospheric ozone (O-3) has been developed. The system utilizes the relative response of an O-3-sensitive clone (NC-S) and an O-3-resistant clone (NC-R) grown in 15-liter pots. Forage (leaves, stems and flowers) is cut, dried, and weighed at 28-day intervals. Forage dry weight ratios (NC-S/NC-R) for individual or multiple harvests indicate O-3 concentrations during growth. In, 3 years of testing in open-top field chambers at Raleigh. North Carolina, O-3 always decreased growth of NC-S more than that of NC-R and the NC-S/NC-R ratio routinely decreased as the O-3 concentration increased. A national field test was performed in 1993 and 1994 to determine if the clover system can account for effects of climatic variables on clover growth per-se, and if climatic variables affect the relative response of the two clones to O-3. Eight locations (Corvallis, Oregon; Kennedy Space Center, Florida; Delaware, Ohio; Amherst, Massachusetts; Blacksburg, Virginia; Raleigh, North Carolina; Riverside, California; San Bernardino mountains. California) provided large differences in O-3 concentrations and climate. The NC-SINC-R forage ratios for three consecutive 28-day manuscript. Ratios were generally highest where mean O-3 concentrations were lowest (Oregon and Florida), lowest where mean O-3 concentrations were highest (both California locations), and intermediate at other locations. C1 VIRGINIA TECH,BLACKSBURG,VA. NASA,KENNEDY SPACE CTR,FL. UNIV MASSACHUSETTS,AMHERST,MA 01003. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. US EPA,CORVALLIS,OR. USDA,FOREST SERV,DELAWARE,OH. RP Heagle, AS (reprint author), USDA,ARS,RALEIGH,NC, USA. OI Dreschel, Thomas/0000-0003-2211-5733 NR 15 TC 33 Z9 34 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD DEC PY 1995 VL 85 IS 3 BP 1373 EP 1378 DI 10.1007/BF00477173 PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA UD335 UT WOS:A1995UD33500056 ER PT J AU BEY, KS PATRA, A ODEN, JT AF BEY, KS PATRA, A ODEN, JT TI HP-VERSION DISCONTINUOUS GALERKIN METHODS FOR HYPERBOLIC CONSERVATION-LAWS - A PARALLEL ADAPTIVE STRATEGY SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE HP-METHODS; PARALLEL COMPUTING; HYPERBOLIC EQUATIONS; ADAPTIVE METHODS ID ELEMENT AB This paper describes a parallel algorithm based on discontinuous hp-finite element approximations of linear, scalar, hyperbolic conservation laws. The paper focuses on the development of an effective parallel adaptive strategy for such problems. Numerical experiments suggest that these techniques are highly parallelizable and exponentially convergent, thereby yielding efficiency many times superior to conventional schemes for hyperbolic problems. C1 UNIV TEXAS,TEXAS INST COMPUTAT & APPL MECH,AUSTIN,TX 78712. RP BEY, KS (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 396,HAMPTON,VA 23681, USA. RI Patra, Abani/F-8262-2016 NR 17 TC 32 Z9 32 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD NOV 30 PY 1995 VL 38 IS 22 BP 3889 EP 3908 DI 10.1002/nme.1620382209 PG 20 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA TE470 UT WOS:A1995TE47000008 ER PT J AU COPI, CJ SCHRAMM, DN TURNER, MS AF COPI, CJ SCHRAMM, DN TURNER, MS TI ASSESSING BIG-BANG NUCLEOSYNTHESIS SO PHYSICAL REVIEW LETTERS LA English DT Article ID PRIMORDIAL NUCLEOSYNTHESIS; DEUTERIUM; ORIGIN AB Systematic uncertainties in the light-element abundances and their evolution complicate a rigorous statistical assessment. However, using Bayesian methods we show that the following statement is robust: The predicted and measured abundances are consistent with 95% credibility only if the baryon-to-photon ratio is between 2 X 10(-10) and 6.5 X 10(-10) and the number of light neutrino species is less than 3.9. Our analysis suggests that the He-4 abundance may have been systematically underestimated. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP COPI, CJ (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637, USA. NR 25 TC 114 Z9 114 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 NOV 27 PY 1995 VL 75 IS 22 BP 3981 EP 3984 DI 10.1103/PhysRevLett.75.3981 PG 4 WC Physics, Multidisciplinary SC Physics GA TF684 UT WOS:A1995TF68400004 ER PT J AU STOFAN, ER SMREKAR, SE BINDSCHADLER, DL SENSKE, DA AF STOFAN, ER SMREKAR, SE BINDSCHADLER, DL SENSKE, DA TI LARGE TOPOGRAPHIC RISES ON VENUS - IMPLICATIONS FOR MANTLE UPWELLING SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID BETA-REGIO; GLOBAL DISTRIBUTION; LAVINIA-PLANITIA; FLOOD BASALTS; MAGELLAN DATA; EISTLA REGIO; VOLCANISM; GEOLOGY; TECTONICS; CORONAE AB Topographic rises on Venus have been identified that are interpreted to be the surface manifestation of mantle upwellings. These features are classified into groups based on their dominant morphology. Atla and Beta Regiones are classified as rift-dominated, Dione, western Eistla, Bell, and Imdr Regiones as volcano-dominated, and Themis, eastern Eistla, and central Eistla Regiones as corona-dominated. At several topographic rises, geologic indicators were identified that may provide evidence of uplifted topography (e.g., volcanic flow features trending upslope). We assessed the minimum contribution of volcanic construction to the topography of each rise, which in general represents less than 5% of the volume of the rise, similar to the volumes of edifices at terrestrial hotspot swells. The total melt volume at each rise is approximated to be 10(4)-10(6) km(3). The variations in morphology, topography, and gravity signatures at topographic rises are not interpreted to indicate variations in stage of evolution of a mantle upwelling. Instead, the morphologic variations between the three classes of topographic rises are interpreted to indicate the varying influences of lithospheric structure, plume characteristics, and regional tectonic environment. Within each class, variations in topography, gravity, and amount of volcanism may be indicative of differing stages of evolution. The similarity between swell and volcanic volumes for terrestrial and Venusian hotspots implies comparable time-integrated plume strengths for individual upwellings on the two planets. C1 UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90024. RP STOFAN, ER (reprint author), CALTECH,JET PROP LAB,MS 183-501,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 65 TC 48 Z9 49 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 25 PY 1995 VL 100 IS E11 BP 23317 EP 23327 DI 10.1029/95JE01834 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TH091 UT WOS:A1995TH09100006 ER PT J AU BENEDETTO, S DIVSALAR, D MONTORSI, G POLLARA, F AF BENEDETTO, S DIVSALAR, D MONTORSI, G POLLARA, F TI BANDWIDTH EFFICIENT PARALLEL CONCATENATED CODING SCHEMES SO ELECTRONICS LETTERS LA English DT Article DE DIGITAL COMMUNICATION SYSTEMS; CONVOLUTIONAL CODES AB The authors propose a solution to the parallel concatenation of trellis codes with multilevel amplitude/phase modulations and a suitable iterative decoding structure. Examples are given for throughputs 2bit/s/Hz with 8PSK and 16QAM signal constellations. For parallel concatenated trellis codes in the examples, rate 2/3 and 4/5, 16-state binary convolutional codes with Gray code mapping are used. The performances of these codes are within 1dB of the Shannon limit at a bit error probability of 10(-6) for a given throughput. This outperforms all codes reported in the past for the same throughput. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. RP BENEDETTO, S (reprint author), POLITECN TORINO, DIPARTIMENTO ELETTR, C DUCA ABRUZSI 24, I-10129 TURIN, ITALY. RI Montorsi, Guido/D-4867-2012; OI benedetto, sergio/0000-0002-7648-5396 NR 5 TC 35 Z9 37 U1 0 U2 0 PU INST ENGINEERING TECHNOLOGY-IET PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD NOV 23 PY 1995 VL 31 IS 24 BP 2067 EP 2069 DI 10.1049/el:19951447 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA TJ614 UT WOS:A1995TJ61400008 ER PT J AU MONKS, PS NESBITT, FL PAYNE, WA SCANLON, M STIEF, LJ SHALLCROSS, DE AF MONKS, PS NESBITT, FL PAYNE, WA SCANLON, M STIEF, LJ SHALLCROSS, DE TI ABSOLUTE RATE-CONSTANT AND PRODUCT BRANCHING RATIOS FOR THE REACTION BETWEEN H AND C2H3 AT T=213 AND 298 K SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID THERMAL UNIMOLECULAR REACTIONS; DENSE INTERSTELLAR CLOUDS; COLLISION RATE CONSTANTS; VINYL RADICALS; TEMPERATURE-DEPENDENCE; MOLECULAR-OXYGEN; FLUORINE-ATOMS; KINETIC DATA; ACETYLENE; CHEMISTRY AB The discharge-flow kinetic technique coupled to mass-spectrometric detection has been used to determine the variable-temperature dependence of the rate constant and product branching ratios for the reaction between H and C2H3 at 1 Torr nominal pressure (He). Atomic hydrogen was produced from the reaction between F(P-2) and H-2 while the vinyl radical was produced simultaneously from the reaction between F(P-2) and ethylene, which gives both C2H3 and H. The reaction was studied at T = 213 and 298 K by monitoring the decay of C2H3 in the presence of a large excess of H. The rate constants were determined to be k(H + C2H3)(298 K) = (1.1 +/- 0.3) x 10(-10) and k(H+C2H3)(213 K) = (1.0 +/- 0.3) x 10(-10) both in the units cm(3) molecule(-1) s(-1); the quoted uncertainty represents total errors. The activation energy for the reaction between H and C2H3 is therefore near zero over the temperature range studied. Further, the fractional product yields for the channels H + C2D3 --> C2D3H (a) and H + C2D3 --> C2D2 + HD (b) were determined by quantitatively measuring the yields of both C2D3H and HD independently. The derived fractional product yields were Gamma(a)(298 K) = 0.33 +/- 0.13, Gamma(b)(298 K) = 0.67 +/- 0.18, Gamma(a)(213 K) = 0.24 +/- 0.09, and Gamma(b)(213 K) = 0.76 +/- 0.16, where the quoted uncertainty represents total errors. Quantum RRK (QRRK) calculations have been undertaken to investigate the relationship between the observed kinetics, products, and possible mechanisms. With the available data and the QRRK calculations, a mechanism of the form H + C2H3 + M <-> [H-C2H3]* --> C2H4 + M (a) and H + C2H3 --> H-2 + C2H2 (b) is shown to be most likely. Further, Tree calculations have been undertaken in order to suggest values for the limiting low-pressure rate coefficients. A brief comparison is made between the results of the Tree and QRRK analyses. The implications for the conversion of C2H2 to C2H6 in the relatively low temperature conditions of planetary atmospheres are briefly discussed. C1 NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. UNIV CAMBRIDGE,DEPT CHEM,CTR ATMOSPHER SCI,CAMBRIDGE CB2 1EW,ENGLAND. RI Monks, Paul/H-6468-2016 OI Monks, Paul/0000-0001-9984-4390 NR 62 TC 35 Z9 35 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 23 PY 1995 VL 99 IS 47 BP 17151 EP 17159 DI 10.1021/j100047a018 PG 9 WC Chemistry, Physical SC Chemistry GA TF811 UT WOS:A1995TF81100018 ER PT J AU LEE, TJ DATEO, CE AF LEE, TJ DATEO, CE TI THE HEAT OF FORMATION OF HNO SO JOURNAL OF CHEMICAL PHYSICS LA English DT Note RP LEE, TJ (reprint author), NASA,AMES RES CTR,INST THERMOSCI,MS 230-3,MOFFETT FIELD,CA 94035, USA. RI Lee, Timothy/K-2838-2012 NR 20 TC 24 Z9 24 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 22 PY 1995 VL 103 IS 20 BP 9110 EP 9111 DI 10.1063/1.470022 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TF298 UT WOS:A1995TF29800035 ER PT J AU HAKKILA, J MEEGAN, CA PENDLETON, GN HORACK, JM BRIGGS, MS PACIESAS, WS EMSLIE, AG AF HAKKILA, J MEEGAN, CA PENDLETON, GN HORACK, JM BRIGGS, MS PACIESAS, WS EMSLIE, AG TI GALACTIC GAMMA-RAY BURST MODELS - CONSTRAINTS ON THE INTRINSIC LUMINOSITY FUNCTION SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXY, HALO; GAMMA RAYS, BURSTS; METHODS, DATA ANALYSIS ID HALO MODELS; DISK; BATSE AB Constraints are found on the intrinsic luminosity function of Galactic gamma-ray bursts from analysis of the BATSE/PVO combined intensity distribution, assuming burst origins in an extended halo with a radial source density decreasing beyond an homogeneous core, and assuming that the intrinsic luminosity function can be modeled as a truncated power law. Initially a spherical heliocentric extended halo is assumed as a first-order approximation. Analysis of the model log (N > F-p) versus log F-p curves allows the interaction between the intrinsic luminosity function and space distribution to be studied, from which it is found that most of the observed bursts (the ''observed luminosity function'') are selected from a narrow luminosity range favoring one or both ends of the intrinsic luminosity function. Subsequent testing of Galactocentric halo models for consistency with the observational limits on anisotropies yields the strongest constraints on Galactic gamma-ray burst luminosity functions. These constraints require that the intrinsic luminosities span less than a factor of 5 for reasonable luminosity power-law indices. A radially dependent Galactic luminosity distribution or an evolution of sources can slightly relax these constraints. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. UNIV ALABAMA,DEPT PHYS,HUNTSVILLE,AL 35899. RP HAKKILA, J (reprint author), MANKATO STATE UNIV,DEPT PHYS & ASTRON,MANKATO,MN 56002, USA. RI Horack, John/J-6670-2016 NR 40 TC 19 Z9 19 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 1995 VL 454 IS 1 BP 134 EP 143 DI 10.1086/176472 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TD743 UT WOS:A1995TD74300014 ER PT J AU BORKOWSKI, KJ DWEK, E AF BORKOWSKI, KJ DWEK, E TI THE FRAGMENTATION AND VAPORIZATION OF DUST IN GRAIN-GRAIN COLLISIONS SO ASTROPHYSICAL JOURNAL LA English DT Article DE DUST, EXTINCTION ID INTER-STELLAR SPACE; HEAVY ELEMENT DEPLETION; INTERSTELLAR GRAINS; INFRARED-EMISSION; HOT GAS; TEMPERATURE-FLUCTUATIONS; DESTRUCTION; SHOCKS; GROWTH; MOLECULES AB We present a detailed analysis of the evolution of the size distribution of fast-moving interstellar dust particles decelerating in a dusty plasma. The physical processes considered in this paper include sputtering by gas-grain collisions, and partial and complete evaporation, fragmentation, and cratering by grain-grain collisions. We find that the final distribution of grains, initially characterized by a power-law distribution in grain sizes, exhibits an excess of small-to-large particles, compared to the initial distribution. This excess depends on the initial grain velocity and should be detectable by infrared observations of low- and intermediate-velocity clouds with the Infrared Space Observatory scheduled for launch around 1996. C1 NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. UNIV MARYLAND,DEPT AGRON,COLLEGE PK,MD 20742. NR 48 TC 35 Z9 35 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 1995 VL 454 IS 1 BP 254 EP 276 DI 10.1086/176480 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TD743 UT WOS:A1995TD74300022 ER PT J AU BERNSTEIN, MP SANDFORD, SA ALLAMANDOLA, LJ CHANG, S SCHARBERG, MA AF BERNSTEIN, MP SANDFORD, SA ALLAMANDOLA, LJ CHANG, S SCHARBERG, MA TI ORGANIC-COMPOUNDS PRODUCED BY PHOTOLYSIS OF REALISTIC INTERSTELLAR AND COMETARY ICE ANALOGS CONTAINING METHANOL SO ASTROPHYSICAL JOURNAL LA English DT Article DE DUST, EXTINCTION; INFRARED, ISM, LINES AND BANDS; ISM, MOLECULES; MOLECULAR PROCESSES ID TIME-DEPENDENT CHEMISTRY; DENSE MOLECULAR CLOUDS; INFRARED-SPECTROSCOPY; ASTROPHYSICAL ICES; MICRON ABSORPTION; GRAIN MANTLES; HALLEY; CO; SPECTRUM; POLYOXYMETHYLENE AB The infrared CIR) spectra of ultraviolet (UV) and thermally processed, methanol-containing interstellar/cometary ice analogs at temperatures from 12 to 300 K are presented. Infrared spectroscopy, H-1 and C-13 nuclear magnetic resonance (NMR) spectroscopy, and gas chromatography-mass spectrometry indicate that CO (carbon monoxide), CO2 (carbon dioxide), CH4 (methane), HCO (the formyl radical), H2CO (formaldehyde), CH3CH2OH (ethanol), HC(=O)NH2 (formamide), CH3C(=O)NH2 (acetamide), and R-C=N (nitriles) are formed. In addition, the organic materials remaining after photolyzed ice analogs have been warmed to room temperature contain (in rough order of decreasing abundance), (1) hexamethylenetetramine (HMT, C6H12N4), (2) ethers, alcohols, and compounds related to polyoxymethylene {POM, (-CH2O-)(n)}, and (3) ketones {R-C(=O)-R'} and amides {H2NC(=O)-R}. Most of the carbon in these residues is thought to come from the methanol in the original ice. Deuterium and C-13 isotopic labeling demonstrates that methanol is definitely the source of carbon in HMT. High concentrations of HMT in interstellar and cometary ices could have important astrophysical consequences. The ultraviolet photolysis of HMT frozen in H2O ice readily produces the ''XCN'' band observed in the spectra of protostellar objects and laboratory ices, as well as other nitriles. Thus, HMT may be a precursor of XCN and a source of CN in comets and the interstellar medium. Also, HMT is known to hydrolyze under acidic conditions to yield ammonia, formaldehyde, and amino acids. Thus, HMT may be a significant source of prebiogenic compounds on asteroidal parent bodies. A potential mechanism for the radiative formation of HMT in cosmic ices is outlined. C1 SAN JOSE STATE UNIV,DEPT CHEM,SAN JOSE,CA 95192. RP BERNSTEIN, MP (reprint author), NASA,AMES RES CTR,MAIL STOP 245-6,MOFFETT FIELD,CA 94035, USA. NR 73 TC 305 Z9 308 U1 4 U2 57 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 1995 VL 454 IS 1 BP 327 EP 344 DI 10.1086/176485 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TD743 UT WOS:A1995TD74300027 ER PT J AU ASKER, JR AF ASKER, JR TI ATLANTIS PASSES FIRST STATION ASSEMBLY TEST SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Article RP ASKER, JR (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 SN 0005-2175 J9 AVIAT WEEK SPACE TEC JI Aviat. Week Space Technol. PD NOV 20 PY 1995 VL 143 IS 21 BP 90 EP 91 PG 2 WC Engineering, Aerospace SC Engineering GA TF121 UT WOS:A1995TF12100042 ER PT J AU DRINKWATER, MR AF DRINKWATER, MR TI DR VIEHOFF,THOMAS - 26 JUNE 1957-5 DECEMBER 1994 SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Item About an Individual RP DRINKWATER, MR (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD LONDON PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD NOV 20 PY 1995 VL 16 IS 17 BP 3221 EP 3221 PG 1 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA TH689 UT WOS:A1995TH68900001 ER PT J AU GUDMANDSEN, P DRINKWATER, MR AF GUDMANDSEN, P DRINKWATER, MR TI PROGRAM FOR INTERNATIONAL POLAR OCEANS RESEARCH - PREFACE SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Editorial Material C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP GUDMANDSEN, P (reprint author), TECH UNIV DENMARK,DK-2800 LYNGBY,DENMARK. NR 0 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD LONDON PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD NOV 20 PY 1995 VL 16 IS 17 BP 3223 EP 3224 PG 2 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA TH689 UT WOS:A1995TH68900002 ER PT J AU DRINKWATER, MR AF DRINKWATER, MR TI PROGRAM FOR INTERNATIONAL POLAR OCEANS RESEARCH SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Editorial Material RP DRINKWATER, MR (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. OI Drinkwater, Mark/0000-0002-9250-3806 NR 0 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD LONDON PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD NOV 20 PY 1995 VL 16 IS 17 BP 3225 EP 3225 PG 1 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA TH689 UT WOS:A1995TH68900003 ER PT J AU DRINKWATER, MR HOSSEINMOSTAFA, R GOGINENI, P AF DRINKWATER, MR HOSSEINMOSTAFA, R GOGINENI, P TI C-BAND BACKSCATTER MEASUREMENTS OF WINTER SEA-ICE IN THE WEDDELL-SEA, ANTARCTICA SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article AB During the 1992 Winter Weddell Gyre Study, a C-band scatterometer was used from the German ice-breaker R/V Polarstern to obtain detailed shipborne measurement scans of Antarctic sea-ice. The frequency-modulated continuous-wave (FM-CW) radar operated at 4.3 GHz and acquired like- (VV) and cross-polarization (HV) data at a variety of incidence angles (10-75 degrees). Calibrated backscatter data were recorded for several ice types as the icebreaker crossed the Weddell Sea and detailed measurements were made of corresponding snow and sea-ice characteristics at each measurement site, together with meteorological information, radiation budget and oceanographic data. The primary scattering contributions under cold winter conditions arise from the air/snow and snow/ice interfaces. Observations indicate some similarities with Arctic sea-ice scattering signatures, although the main difference is generally lower mean backscattering coefficients in the Weddell Sea. This is due to the younger mean ice age and thickness, and correspondingly higher mean salinities. In particular, smooth white ice found in 1992 in divergent areas within the Weddell Gyre ice pack was generally extremely smooth and undeformed. Comparisons of held scatterometer data with calibrated 20-26 degrees incidence ERS-1 radar image data show close correspondence, and indicate that rough Antarctic first-year and older second-year ice forms do not produce as distinctively different scattering signatures as observed in the Arctic. Thick deformed first-year and second-year ice on the other hand are clearly discriminated from younger undeformed ice, thereby allowing successful separation of thick and thin ice. Time-series data also indicate that C-band is sensitive to changes in snow and ice conditions resulting from atmospheric and oceanographic forcing and the local heat flux environment. Variations of several dB in 45 degrees incidence backscatter occur in response to a combination of thermally-regulated parameters including sea-ice brine volume, snow and ice complex dielectric properties, and snow physical properties. C1 UNIV KANSAS,CTR RES INC,RADAR SYST & REMOTE SENSING LAB,LAWRENCE,KS 66045. CALTECH,JET PROP LAB,PASADENA,CA 91109. OI Drinkwater, Mark/0000-0002-9250-3806 NR 20 TC 14 Z9 14 U1 0 U2 2 PU TAYLOR & FRANCIS LTD LONDON PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD NOV 20 PY 1995 VL 16 IS 17 BP 3365 EP 3389 PG 25 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA TH689 UT WOS:A1995TH68900011 ER PT J AU JOINER, J BHARTIA, PK AF JOINER, J BHARTIA, PK TI THE DETERMINATION OF CLOUD PRESSURES FROM ROTATIONAL RAMAN-SCATTERING IN SATELLITE BACKSCATTER ULTRAVIOLET MEASUREMENTS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB We have retrieved cloud pressures with the Nimbus 7 solar backscatter ultraviolet spectrometer and total ozone mapping spectrometer by utilizing properties of rotational Raman scattering. The retrieved cloud pressures are compared with coincident cloud pressures derived from the temperature humidity infrared sounder, as well as climatological cloud pressures from the International Satellite Cloud Climatology Project. Results show good agreement between cloud pressures measured using ultraviolet and infrared techniques, although a small bias is present. The bias in cloud pressures is likely due in part to different radiative properties of clouds at ultraviolet and infrared wavelengths. The ultraviolet measurements described here are sensitive to cloud optical thickness, while infrared measurements are sensitive to cloud top temperature. Ultraviolet cloud pressure measurements combined with measurements from other spectral regions may therefore provide information about cloud type. Cloud pressures measured by means of ultraviolet scattering properties will be more appropriate for use in satellite backscatter ultraviolet ozone retrieval algorithms. We suggest ways in which future ultraviolet remote sounding instruments may be designed to more optimally measure cloud pressure. C1 HUGHES STX CORP, GREENBELT, MD USA. RP JOINER, J (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ATMOSPHERES LAB, CODE 9103, GREENBELT, MD 20771 USA. RI Joiner, Joanna/D-6264-2012; Bhartia, Pawan/A-4209-2016 OI Bhartia, Pawan/0000-0001-8307-9137 NR 15 TC 50 Z9 51 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1995 VL 100 IS D11 BP 23019 EP 23026 DI 10.1029/95JD02675 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TF791 UT WOS:A1995TF79100022 ER PT J AU DESSLER, AE HINTSA, EJ WEINSTOCK, EM ANDERSON, JG CHAN, KR AF DESSLER, AE HINTSA, EJ WEINSTOCK, EM ANDERSON, JG CHAN, KR TI MECHANISMS CONTROLLING WATER-VAPOR IN THE LOWER STRATOSPHERE - A TALE OF 2 STRATOSPHERES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AIRCRAFT AB We present an analysis of the mechanisms controlling stratospheric water vapor based on in situ profiles made at 37.4 degrees N and at altitudes up to 20 km. The stratosphere can be conveniently divided into two air masses: the overworld (potential temperature theta > 380 K) and the lowermost stratosphere (theta < 380). Our data support the canonical theory that air primarily enters the overworld by passing through the tropical tropopause. The low water vapor mixing ratios in the overworld, a few parts per million by volume (ppmv), are determined by the low temperatures encountered at the tropical tropopause, as well as oxidation of methane and molecular hydrogen. Air enters the lowermost stratosphere both by diabatically descending from the overworld across the 380-K potential temperature surface and by passing through the extratropical tropopause. Air parcels crossing the extratropical tropopause experience higher temperatures than air crossing the tropical tropopause, allowing higher water vapor in the lowermost stratosphere (tens of ppmv) than in the overworld. Our data are consistent with the pathway for air crossing the extratropical tropopause being isentropic advection from lower latitudes, although we cannot exclude contributions from other paths. C1 HARVARD UNIV, ATMOSPHER RES PROJECT, CAMBRIDGE, MA 02138 USA. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RP DESSLER, AE (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CODE 916, GREENBELT, MD 20771 USA. RI Dessler, Andrew/G-8852-2012 OI Dessler, Andrew/0000-0003-3939-4820 NR 25 TC 78 Z9 79 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1995 VL 100 IS D11 BP 23167 EP 23172 DI 10.1029/95JD02455 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TF791 UT WOS:A1995TF79100036 ER PT J AU REISINGER, AR JONES, NB MATTHEWS, WA RINSLAND, CP AF REISINGER, AR JONES, NB MATTHEWS, WA RINSLAND, CP TI SOUTHERN-HEMISPHERE MIDLATITUDE GROUND-BASED MEASUREMENTS OF CLONO2 - METHOD OF ANALYSIS, SEASONAL CYCLE AND LONG-TERM TREND SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHLORINE NITRATE CLONO2; ARCTIC WINTER; Q-BRANCH; SPECTRA; SPECTROSCOPY; STRATOSPHERE; PHOTOLYSIS; BANDS; HCL AB We report the first long-term analysis of the total column of ClONO2 from ground-based infrared solar absorption measurements recorded at Lauder, New Zealand (45 degrees S, 170 degrees E, 370 m above sea level (asl)). Between September 1990 and August 1994 the ClONO2, total column averaged 1.22(+/-0.4)x10(15) cm(-2) (1 sigma standard deviation), in good agreement with previous airborne and spaceborne measurements at southern hemisphere midlatitudes. The monthly mean ClONO2 column over Lauder shows a clear seasonal cycle with a peak amplitude of 22(+/-3)% of the yearly mean (lo standard error) with the seasonal maximum occurring in early September. This is the first measured seasonal variation of ClONO2. Within the error limits, the derived September 1990 to August 1994 total column increase rate of 1.3(+/-2)% per year (1 sigma standard error) is consistent with determinations of the recent growth rate of atmospheric chlorine. C1 NASA, LANGLEY RES CTR, HAMPTON, VA 23665 USA. UNIV CANTERBURY, CHRISTCHURCH 1, NEW ZEALAND. RP REISINGER, AR (reprint author), NATL INST WATER & ATMOSPHER RES, PRIVATE BAG 50061, CENT OTAGO, LAUDER, NEW ZEALAND. RI Jones, Nicholas/G-5575-2011 OI Jones, Nicholas/0000-0002-0111-2368 NR 28 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1995 VL 100 IS D11 BP 23183 EP 23193 DI 10.1029/95JD02529 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA TF791 UT WOS:A1995TF79100038 ER PT J AU YOSHIMURA, K ORITO, S UEDA, I ANRAKU, K GOLDEN, R IMORI, M INABA, S KIMBELL, B KIMURA, N MAKIDA, Y MATSUMOTO, H MATSUNAGA, H MITCHELL, J MOTOKI, M NISHIMURA, J NOZAKI, M ORMES, J SAEKI, T STREITMATTER, R SUZUKI, J TANAKA, K YAJIMA, N YAMAGAMI, T YAMAMOTO, A YOSHIDA, T AF YOSHIMURA, K ORITO, S UEDA, I ANRAKU, K GOLDEN, R IMORI, M INABA, S KIMBELL, B KIMURA, N MAKIDA, Y MATSUMOTO, H MATSUNAGA, H MITCHELL, J MOTOKI, M NISHIMURA, J NOZAKI, M ORMES, J SAEKI, T STREITMATTER, R SUZUKI, J TANAKA, K YAJIMA, N YAMAGAMI, T YAMAMOTO, A YOSHIDA, T TI OBSERVATION OF COSMIC-RAY ANTIPROTONS AT ENERGIES BELOW 500 MEV SO PHYSICAL REVIEW LETTERS LA English DT Article ID PRIMORDIAL BLACK-HOLES; ANTI-PROTONS; DARK MATTER; RADIATION; RATIO AB A search for cosmic-ray antiprotons was performed using a balloon-borne experiment with a superconducting magnetic rigidity spectrometer (BESS). We have detected four antiprotons in the kinetic energy range between 300 and 500 MeV, the first antiprotons to be identified by a direct mass measurement. The corresponding (p) over bar/p flux ratio at the top of the atmosphere is found to be 1.2(-0.65)(+1.0) X 10(-5). No antiprotons were observed in the range between 175 and 300 MeV, resulting in a 90% C.L. upper limit on the flux ratio of 2.9 X 10(-5). C1 NATL LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI,JAPAN. NEW MEXICO STATE UNIV,LAS CRUCES,NM 88003. KOBE UNIV,KOBE,HYOGO,JAPAN. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. INST SPACE & ASTRONAUT SCI,SAGAMIHARA,KANAGAWA 229,JAPAN. RP YOSHIMURA, K (reprint author), UNIV TOKYO,BUNKYO KU,TOKYO 113,JAPAN. RI MOTOKI, Masakazu/B-4212-2009 NR 29 TC 71 Z9 71 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 NOV 20 PY 1995 VL 75 IS 21 BP 3792 EP 3795 DI 10.1103/PhysRevLett.75.3792 PG 4 WC Physics, Multidisciplinary SC Physics GA TF246 UT WOS:A1995TF24600003 ER PT J AU PARTRIDGE, H BAUSCHLICHER, CW VISSCHER, L AF PARTRIDGE, H BAUSCHLICHER, CW VISSCHER, L TI THE DISSOCIATION-ENERGIES OF ALH2 AND ALAR SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; ATOMS; SPECTROSCOPY; ARGON AB The D-0 values for AlH2 and AlAr are computed using the coupled cluster approach in conjunction with large basis sets. Basis set superposition and spin-orbit effects are accounted for, as they are significant due to the small binding energy. The computed dissociation energy (D-0) for AlAr is 114 cm(-1), which is 93% of the experimental value (122.4 cm(-1)). Our best estimate for the Al-H-2 binding energy is 38+/-26 cm(-1). C1 UNIV GRONINGEN, PHYS CHEM LAB, 9747 AG GRONINGEN, NETHERLANDS. RP PARTRIDGE, H (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RI Visscher, Lucas/A-3523-2010 OI Visscher, Lucas/0000-0002-7748-6243 NR 24 TC 23 Z9 24 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 17 PY 1995 VL 246 IS 1-2 BP 33 EP 39 DI 10.1016/0009-2614(95)01079-O PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TE595 UT WOS:A1995TE59500006 ER PT J AU BAUSCHLICHER, CW AF BAUSCHLICHER, CW TI A COMPARISON OF THE ACCURACY OF DIFFERENT FUNCTIONALS SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DENSITY; ENERGIES; APPROXIMATION; DYNAMICS; EXCHANGE; GAS AB The errors in the computed geometries, zero-point energies, and atomization energies of molecules containing only first and second row atoms are compared for several levels of theory, including Hartree-Fock, second-order Moller-Plesset perturbation theory (MP2), and density functional theory (DFT) using five different functionals, including two hybrid functionals. The 6-31G* and 6-311 + G(3df, 2p) basis sets are used. Overall, the B3LYP hybrid functional yields the best results. RP BAUSCHLICHER, CW (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NR 28 TC 362 Z9 362 U1 2 U2 27 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 NOV 17 PY 1995 VL 246 IS 1-2 BP 40 EP 44 DI 10.1016/0009-2614(95)01089-R PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TE595 UT WOS:A1995TE59500007 ER PT J AU KOYAMA, K PETRE, R GOTTHELF, EV HWANG, U MATSUURA, M OZAKI, M HOLT, SS AF KOYAMA, K PETRE, R GOTTHELF, EV HWANG, U MATSUURA, M OZAKI, M HOLT, SS TI EVIDENCE FOR SHOCK ACCELERATION OF HIGH-ENERGY ELECTRONS IN THE SUPERNOVA REMNANT SN1006 SO NATURE LA English DT Article ID X-RAY-SPECTRUM; MAXIMUM ENERGY; NOVA REMNANT; CRAB-LIKE; SN-1006; EMISSION; MODELS AB High-energy cosmic rays (relativistic heavy nuclei) play an important role in heating interstellar matter in the Milky Way(1,2), and they affect chemical abundances through collisions with atoms in the interstellar gas(2). Although it has long been thought that these cosmic rays arise from supernovae(3,4), direct evidence for such an association has been lacking. Here we report X-ray observations of the remnant of supernova 1006, made by the ASCA satellite, which indicate that emission from the edges of the remnant shell is dominated by radiation from electrons accelerated to energies of similar to 100 TeV within the shock front. Ions in the shell are likely to have been accelerated to similar energies, thus giving rise to very-high-energy cosmic rays. C1 NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. UNIV SPACE RES ASSOC,SEABROOK,MD 20706. RP KOYAMA, K (reprint author), KYOTO UNIV,DEPT PHYS,SAKYO KU,KYOTO 66601,JAPAN. RI Ozaki, Masanobu/K-1165-2013 NR 37 TC 619 Z9 622 U1 0 U2 7 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 16 PY 1995 VL 378 IS 6554 BP 255 EP 258 DI 10.1038/378255a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TE858 UT WOS:A1995TE85800040 ER PT J AU RICCA, A BAUSCHLICHER, CW AF RICCA, A BAUSCHLICHER, CW TI THE LOW-LYING ELECTRONIC STATES OF YCU SO CHEMICAL PHYSICS LA English DT Article ID COUPLED-CLUSTER THEORY; GAUSSIAN-BASIS SETS; MOLECULAR CALCULATIONS; WAVE-FUNCTIONS; HARTREE-FOCK; ATOMS; ORBITALS AB The spectroscopic constants for the singlet and triplet stares of YCu below about 15 000 cm(-1) are determined using an internally contracted multireference configuration-interaction approach. These calculations are calibrated by studies of fewer states using higher levels of correlation treatment and/or larger basis sets. The computed T-c values and radiative lifetimes are in reasonable agreement with experiment. The calculations confirm the previous experimental assignment for all but one state, where theory helps resolve between two possible assignments. RP RICCA, A (reprint author), NASA,AMES RES CTR,STC 230-3,MOFFETT FIELD,CA 94035, USA. NR 23 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD NOV 15 PY 1995 VL 200 IS 3 BP 337 EP 345 DI 10.1016/0301-0104(95)00231-6 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TF321 UT WOS:A1995TF32100006 ER PT J AU MENGEL, JG MAYR, HG CHAN, KL HINES, CO REDDY, CA ARNOLD, NF PORTER, HS AF MENGEL, JG MAYR, HG CHAN, KL HINES, CO REDDY, CA ARNOLD, NF PORTER, HS TI EQUATORIAL OSCILLATIONS IN THE MIDDLE ATMOSPHERE GENERATED BY SMALL-SCALE GRAVITY-WAVES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SEMIANNUAL OSCILLATION; ZONAL WIND; SATURATION; MESOSPHERE; DYNAMICS; PARAMETERIZATION; STRATOSPHERE; MODEL AB A realistic parameterization scheme for the deposition of gravity-wave momentum in the middle atmosphere has been incorporated into the 2D version of a global-scale Numerical Spectral Model of the Earth's middle atmosphere. Here we present early results, obtained with only the simplest assumptions for the incident gravity-wave spectrum - that it is azimuthally isotropic (i, e., identical flux in the four cardinal directions), globally uniform, and unchanging with season - and with essentially ''untuned'' values of tunable parameters. This model reproduces reasonably well the observed anomalous latitudinal temperature distribution and the zonal circulation of the upper mesosphere during solstice, just as other models do. It also produces relatively large oscillations in the mean zonal circulation of the middle atmosphere at low latitudes, descending in altitude with time. In the mesosphere and upper stratosphere, the dominant period is semi-annual and the maximum amplitude is about 20 mis near a height of 50 km. At lower levels, the dominant period is about 20 months and the maximum amplitude is about 8 m/s near 25 km. These values resemble those associated with the observed Semi-Annual Oscillation and Quasi-Biennial Oscillation, respectively, leading us to conclude that small scale gravity waves may contribute significantly to both. C1 GODDARD SPACE FLIGHT CTR,GREENBELT,MD. HONG KONG UNIV SCI & TECHNOL,HONG KONG,HONG KONG. UNIV SPACE RES ASSOC,SEABROOK,MD. FURMAN UNIV,GREENVILLE,SC 29613. RP MENGEL, JG (reprint author), APPL RES CORP,LANDOVER,MD 20785, USA. NR 35 TC 64 Z9 64 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 15 PY 1995 VL 22 IS 22 BP 3027 EP 3030 DI 10.1029/95GL03059 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TF972 UT WOS:A1995TF97200005 ER PT J AU YU, ST JIANG, BN LIU, NS WU, J AF YU, ST JIANG, BN LIU, NS WU, J TI THE LEAST-SQUARES FINITE-ELEMENT METHOD FOR LOW-MACH-NUMBER COMPRESSIBLE VISCOUS FLOWS SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE LOW-MACH-NUMBER FLOWS; LSFEM ID FLUID-DYNAMICS; FORMULATION; CONVECTION AB The present paper reports the development of the Least-Squares Finite Element Method (LSFEM) for simulating compressible viscous flows at low Mach numbers in which the incompressible hows pose as an extreme. The conventional approach requires special treatments for low-speed hows calculations: finite difference and finite volume methods are based on the use of the staggered grid or the preconditioning technique, and finite element methods rely on the mixed method and the operator-splitting method. In this paper, however, we show that such a difficulty does not exist for the LSFEM and no special treatment is needed. The LSFEM always leads to a symmetric, positive-definite matrix through which the compressible flow equations can be effectively solved. Two numerical examples are included to demonstrate the method: driven cavity flows at various Reynolds numbers and buoyancy-driven flows with significant density variation. Both examples are calculated by using full compressible flow equations. C1 NASA,LEWIS RES CTR,OAI,INST COMPUTAT MECH & PROP,CLEVELAND,OH 44135. RP YU, ST (reprint author), NASA,LEWIS RES CTR,NYMA SETAR TEAM,BROOKPARK,OH 44142, USA. NR 26 TC 14 Z9 14 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD NOV 15 PY 1995 VL 38 IS 21 BP 3591 EP 3610 DI 10.1002/nme.1620382104 PG 20 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA TC970 UT WOS:A1995TC97000003 ER PT J AU AMINPOUR, MA RANSOM, JB MCCLEARY, SL AF AMINPOUR, MA RANSOM, JB MCCLEARY, SL TI A COUPLED ANALYSIS METHOD FOR STRUCTURES WITH INDEPENDENTLY MODELED FINITE-ELEMENT SUBDOMAINS SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE PLATES; SHELLS; SUBDOMAIN COUPLING; FINITE ELEMENT; GLOBAL LOCAL AB A new method for analysing plate and shell structures with two or more independently modelled finite element subdomains is presented, assessed, and demonstrated. This method provides a means of coupling local and global finite element models whose nodes do not coincide along their common interface. In general, the method provides a means of coupling structural components (e.g., wing and fuselage) which may have been modelled by different analysts. In both cases, the need for transition modelling, which is often tedious and complicated, is eliminated. The coupling is accomplished through an interface for which three formulations are considered and presented. These formulations are: collocation, discrete least-squares, and hybrid variational. Several benchmark problems are analysed and it is shown that the hybrid variational formulation provides the most accurate solutions. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. LOCKHEED ENGN & SCI CO,HAMPTON,VA 23666. RP AMINPOUR, MA (reprint author), OLD DOMINION UNIV,DEPT AEROSP ENGN,NORFOLK,VA 23529, USA. NR 24 TC 60 Z9 61 U1 2 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD NOV 15 PY 1995 VL 38 IS 21 BP 3695 EP 3718 DI 10.1002/nme.1620382109 PG 24 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA TC970 UT WOS:A1995TC97000008 ER PT J AU MILLAR, TJ ROUEFF, E CHARNLEY, SB RODGERS, SD AF MILLAR, TJ ROUEFF, E CHARNLEY, SB RODGERS, SD TI THE CHEMISTRY OF COMPLEX-MOLECULES IN INTERSTELLAR CLOUDS SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE DEUTERIUM; HOT MOLECULAR CORES; INTERSTELLAR CLOUDS; POLYCYCLIC AROMATIC HYDROCARBONS ID POLYCYCLIC AROMATIC-HYDROCARBONS; DIFFUSE; BANDS; ULTRAVIOLET; EXTINCTION; PAH AB This paper is concerned with the chemical evolution of large molecules in interstellar clouds. We consider the chemistry and ionisation balance of large polycyclic aromatic hydrocarbon (PAH) type molecules in diffuse clouds and show that certain PAH molecules can be doubly ionised by the interstellar ultraviolet radiation field. If recombination of the dications so produced with electrons is dissociative rather than radiative, then PAHs are rapidly destroyed. PAHs which can only be singly ionised have much smaller recombination energies and can be long lasting in these regions. This type of property may be very important in selecting the PAH species which can populate the general interstellar medium and account for certain of the diffuse bands observed in optical spectra. Destruction of PAH molecules via formation of dications may be responsible for the weakening of the diffuse bands observed in regions of high UV flux. We also discuss the chemistry of large, saturated molecules in hot molecular cores in star-forming regions. Here it appears that gas phase abundances are determined by surface chemistry on the cold ice mantles of interstellar grains. We present the preliminary results of a study of deuterium chemistry in these hot cores with the aim of probing both the detailed surface processes by which complex molecules are synthesised and the gas phase reactions which destroy them. C1 OBSERV PARIS, MEUDON, FRANCE. UNIV CALIF BERKELEY, DEPT ASTRON, BERKELEY, CA 94720 USA. NASA, AMES RES CTR, DIV SPACE SCI, MOFFETT FIELD, CA 94035 USA. RP UNIV MANCHESTER, INST SCI & TECHNOL, DEPT PHYS, POB 88, MANCHESTER M60 1QD, LANCS, ENGLAND. RI Charnley, Steven/C-9538-2012; OI Millar, Tom/0000-0001-5178-3656 NR 35 TC 11 Z9 11 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 EI 1873-2798 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD NOV 15 PY 1995 VL 149 BP 389 EP 402 DI 10.1016/0168-1176(95)04270-U PG 14 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA TG497 UT WOS:A1995TG49700035 ER PT J AU WALCH, SP AF WALCH, SP TI CHARACTERIZATION OF THE MINIMUM ENERGY PATHS FOR THE RING-CLOSURE REACTIONS OF C4H3 WITH ACETYLENE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS AB The ring closure reaction of C4H3 with acetylene to give phenyl radical is one proposed mechanism for the formation of the first aromatic ring in hydrocarbon combustion. There are two low-lying isomers of C4H3; 1-dehydro-buta-1-ene-3-yne (n-C4H3) and 2-dehydro-buta-1-ene-3-yne (iso-C4H3). It has been proposed that only n-C4H3 reacts with acetylene to give phenyl radical, and since iso-C4H3 is more stable than n-C4H3, formation of phenyl radical by this mechanism is unlikely. We report restricted Hartree-Fock (RHF) plus singles and doubles configuration interaction calculations with a Davidson's correction (RHF+1+2+Q) using the Dunning correlation consistent Polarized valence double zeta basis set (cc-pVDZ) for stationary point structures along the reaction pathway for the reactions of n-C4H3 and iso-C4H3 With acetylene. n-C4H3 plus acetylene (9.4) has a small entrance channel barrier (17.7) (all energetics in parentheses are in kcal/mol with respect to iso-C4H3 plus acetylene) and the subsequent closure steps leading to phenyl radical (-91.9) are downhill with respect to the entrance channel barrier. Iso-C4H3 plus acetylene also has an entrance channel barrier (14.9) and there is a downhill pathway to l-dehydro-fulvene (-55.0). 1-dehydro-fulvene can rearrange to 6-dehydro-fulvene (-60.3) by a 1.3-hydrogen shift over a barrier (4.0), which is still below the entrance channel barrier,from which rearrangement to phenyl radical can occur by a downhill pathway. Thus, both n-C4H3 and iso-C4H3 can react with acetylene to give phenyl radical with small barriers. (C) 1995 American Institute of Physics. RP WALCH, SP (reprint author), NASA,AMES RES CTR,INST THERMOSCI,MOFFETT FIELD,CA 94035, USA. NR 11 TC 36 Z9 38 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 15 PY 1995 VL 103 IS 19 BP 8544 EP 8547 DI 10.1063/1.470164 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA TE364 UT WOS:A1995TE36400022 ER PT J AU HAKKINEN, S AF HAKKINEN, S TI SEASONAL SIMULATION OF THE SOUTHERN-OCEAN COUPLED ICE-OCEAN SYSTEM SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; SEA-ICE; WEDDELL SEA; BOTTOM WATER; MIXED LAYER; FRESH-WATER; THICKNESS DISTRIBUTION; NUMERICAL-MODEL; LARGE-SCALE; HEAT AB The Southern Ocean ice-ocean system is investigated using a coupled model developed at Princeton University. The ocean model uses the primitive equations and solves the second-moment closure for turbulent mixing; the snow-ice model uses a three-level thermodynamic scheme resembling Semtner's (1976) model. The focus here is to study the seasonal variability of the ice covered areas and water mass formation. The model simulates reasonably well the seasonal cycle of the ice cover in the Southern Ocean. The annual rapid advance of the ice extent is tied to the ice advection away from the coast toward the Antarctic Circumpolar Current (ACC), where it melts rapidly with the increase of radiative fluxes in the austral spring. The European Center for Medium-Range Weather Forecasts climatology tends to produce too little ice in the Pacific sector, for which the primary cause is a weak meridional wind stress. The oceanic heat fluxes are up to 100 W m(-2) in open water areas and along the coastal areas except in the Weddell and Ross Seas, which are occupied by a year-round sea ice cover and have average heat flux of 20 W m(-2) or less. However, there is a small region in the Ross Sea with high heat loss suggesting deep convection. The meridional and zonal heat fluxes are in reasonable agreement with observational estimates. The Atlantic meridional heat flux is zero at 34 degrees S (northern boundary of the model), which is an inadequacy in the model. In the Indian Ocean sector the flux is southward, while in the Pacific sector it is weak and equatorward. From the water mass balance we can deduce that the Antarctic Bottom Water (AABW) (sigma(t) > 27.85) annual production is 12 Sv in the Atlantic sector and 5 Sv in the Ross Sea. The total production of 17 Sv is in excellent agreement with the observational estimates of 10-20 Sv. Intermediate water types are produced in the Indian Ocean sector, where some of the AABW is lost during that conversion. In the Atlantic sector, 6 Sv of the annually formed AABW is advected north across the ACC. In the Pacific sector the northward AABW flow is 7.5 Sv, which is in excess of the Ross Sea production, suggesting that a considerable portion of the AABW formed in the Weddell Sea is contributing to that flux. RP HAKKINEN, S (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HYDROSPHER PROC LAB,CODE 971,GREENBELT,MD 20771, USA. RI Hakkinen, Sirpa/E-1461-2012 NR 59 TC 26 Z9 27 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD NOV 15 PY 1995 VL 100 IS C11 BP 22733 EP 22748 DI 10.1029/95JC02441 PG 16 WC Oceanography SC Oceanography GA TF782 UT WOS:A1995TF78200013 ER PT J AU Sanders, JH Chen, PS Gentz, SJ Parr, RA AF Sanders, JH Chen, PS Gentz, SJ Parr, RA TI Microstructural investigation of the effects of oxygen exposure on NARloy-Z SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE oxygen exposure; high temperatures ID MONTE-CARLO; SEMICOHERENT AB NARloy-Z is a Cu-base alloy used to fabricate the liner of the main combustion chamber (MCC) for the space shuttle main engine (SSME). This study was undertaken to assess the effects of unusual or transient conditions (i.e., high temperature and exposure to high levels of oxygen) on the robustness of the MCC design, providing a data base to better quantify environmental conditions. The results indicated that, upon exposure to severe environmental conditions, wrought NARloy-Z develops extensive microstructural variations which will reduce the service life of an MCC. Oxygen diffusion into the material closely followed predictions based on theoretical considerations. Above 760 degrees C, the presence of oxygen dissociates Cu/AgZr) intermetallics, forms ZrO2, and embrittles the alloy. Above 593 degrees C, Ag precipitates coarsen in the matrix, becoming incoherent and degrading material strength. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,MAT & PROC LAB,MET & FAILURE ANAL BRANCH,HUNTSVILLE,AL 35812. RP Sanders, JH (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,IIT RES INST,MET RES FACIL,HUNTSVILLE,AL 35812, USA. NR 13 TC 5 Z9 5 U1 2 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD NOV 15 PY 1995 VL 203 IS 1-2 BP 246 EP 255 DI 10.1016/0921-5093(95)09822-4 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA TM628 UT WOS:A1995TM62800027 ER PT J AU BEAVIS, D BENNETT, MJ CARROLL, JB CHIBA, J CHIKANIAN, A CRAWFORD, H CRONQVIST, M DARDENNE, Y DEBBE, R DOKE, T ENGELAGE, J GREINER, L HALLMAN, TJ HAYANO, RS HECKMAN, HH KASHIWAGI, T KIKUCHI, J KUMAR, S KUO, C LINDSTROM, PJ MITCHELL, JW NAGAMIYA, S NAGLE, JL POPE, JK STANKUS, P TANAKA, KH WELSH, RC ZHAN, W AF BEAVIS, D BENNETT, MJ CARROLL, JB CHIBA, J CHIKANIAN, A CRAWFORD, H CRONQVIST, M DARDENNE, Y DEBBE, R DOKE, T ENGELAGE, J GREINER, L HALLMAN, TJ HAYANO, RS HECKMAN, HH KASHIWAGI, T KIKUCHI, J KUMAR, S KUO, C LINDSTROM, PJ MITCHELL, JW NAGAMIYA, S NAGLE, JL POPE, JK STANKUS, P TANAKA, KH WELSH, RC ZHAN, W TI CENTRALITY DEPENDENCE OF ANTIPROTON PRODUCTION IN AU+AU COLLISIONS SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS COLLISIONS; PARTICLES; GEV/C; SI AB We have measured the yields of antiprotons in Au + Au interactions in the rapidity range 1.2 < y < 2.8 as a function of centrality using a beam line spectrometer. The shapes of the invariant multiplicity distributions at p(t) = 0 are used to explore the dynamics of antiproton production and annihilation. C1 YALE UNIV,AW WRIGHT NUCL STRUCT LAB,NEW HAVEN,CT 06511. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. NATL LAB HIGH ENERGY PHYS,KEK,TSUKUBA,IBARAKI 305,JAPAN. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. WASEDA UNIV,TOKYO 160,JAPAN. UNIV TOKYO,TOKYO 113,JAPAN. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE SCI RES ASSOC,GREENBELT,MD 20771. COLUMBIA UNIV,NEVIS LAB,IRVINGTON,NY. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. RP BEAVIS, D (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Hayano, Ryugo/F-7889-2012; Kuo, Chaincy/H-9475-2016 OI Hayano, Ryugo/0000-0002-1214-7806; Kuo, Chaincy/0000-0001-7958-8764 NR 28 TC 23 Z9 23 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 NOV 13 PY 1995 VL 75 IS 20 BP 3633 EP 3636 DI 10.1103/PhysRevLett.75.3633 PG 4 WC Physics, Multidisciplinary SC Physics GA TE363 UT WOS:A1995TE36300011 ER PT J AU DOKE, T HAYASHI, T KIKUCHI, J HASEBE, N NAGAOKA, S KATO, M BADHWAR, GD AF DOKE, T HAYASHI, T KIKUCHI, J HASEBE, N NAGAOKA, S KATO, M BADHWAR, GD TI REAL-TIME MEASUREMENT OF LET DISTRIBUTION IN THE IML-2 SPACE-LAB(STS-65) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID DETECTOR; RESOLUTION AB The real time monitoring of environmental radiation in the Space-Lab of STS-65 (IML-2: inclination 28.5 degrees, altitude 300 km) has been achieved successfully through the flight by a new silicon detector telescope called ''Real time Radiation Monitoring Device'' (RRMD). It consists of two 2-dimensional position sensitive silicon detectors and six diode type silicon detectors. In this monitoring, the temporal variation of rates of particle flux, together with the dose equivalent and the LET distribution at three locations in the Space-Lab, were reasonably given in real time. The LET distribution obtained by the RRMD and CR-39 track detectors measured at the same location is in good agreement except at the highest LET region >200 keV/mu m and the lowest LET region <5 keV/mu m. C1 EHIME UNIV,MATSUYAMA,EHIME 790,JAPAN. NASDA,TSUKUBA SPACE CTR,TSUKUBA,IBARAKI 305,JAPAN. NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. RP DOKE, T (reprint author), WASEDA UNIV,ADV RES CTR SCI & ENGN,SHINJUKU KU,OKUBO 3-4-1,TOKYO 169,JAPAN. NR 14 TC 23 Z9 23 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 11 PY 1995 VL 365 IS 2-3 BP 524 EP 532 DI 10.1016/0168-9002(95)00523-4 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA TF304 UT WOS:A1995TF30400030 ER PT J AU WOLFIRE, MG MCKEE, CF HOLLENBACH, D TIELENS, AGGM AF WOLFIRE, MG MCKEE, CF HOLLENBACH, D TIELENS, AGGM TI THE MULTIPHASE STRUCTURE OF THE GALACTIC HALO - HIGH-VELOCITY CLOUDS IN A HOT CORONA SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXY, HALO; ISM, CLOUDS; ISM, STRUCTURE ID INTER-STELLAR GAS; CA-II ABSORPTION; H-I; MAGELLANIC CLOUDS; INTERSTELLAR-MEDIUM; HEAVY-ELEMENTS; GALAXY; ABUNDANCES; DISK; HYDROGEN AB Observations indicate that some high-velocity clouds (HVCs) have a two-phase structure consisting of cold cores and warm envelopes. We calculate the thermal equilibrium gas temperature and investigate the thermal stability of neutral gas in the Galactic halo. Phase diagrams (thermal pressure P vs. gas density n) are presented for gas at a range of heights z above the Galactic plane. Our method accounts for the photoelectric heating from small grains and PAHs and includes a detailed treatment of the ionization rates and heating due to the soft X-ray background and due to cosmic rays. We find that stable two-phase gas exists over a range of heights, but only within a narrow range of pressures at each height. Using a realistic Galactic gravitational potential and using halo parameters consistent with observed properties of the soft X-ray background, we show that a hot (T similar to 1-2 x 10(6) K) Galactic corona can provide the necessary pressure for two-phase HVCs. We find that for an isothermal T = 10(6) K halo, the observed X-ray emission measure (EM(h) = 2.5 x 10(-3) pc cm(-6)) yields a thermal pressure in the Galactic midplane of similar or equal to 2000-3000 K cm(-3), similar to observed pressures. In addition, we find that the electrons in the hot halo make a nonnegligible contribution to the dispersion measure of pulsars far from the Galactic plane. A method is presented for estimating HVC distances from X-ray shadowing measurements. We demonstrate that the two-phase nature of HVCs can be used to constrain the distance to the clouds and their metallicity or origin. A primordial origin (extremely low metallicities) can be ruled out since two phases exist only for z < 2 kpc, contrary to most distance lower limits to HVCs. An extragalactic origin for some clouds, a result of gas stripped from the LMC, is supported by our calculated range of distances over which two-phase clouds exist in a hot corona, the observed dust and metal content, and the high velocities observed for a few HVCs. We predict that no cold cores are expected to be found in a T = 10(6) K halo at distances greater than similar to 20 kpc, which is consistent with the lack of cold cores seen in the Magellanic Stream. However, the mass infall rate to the Galactic plane, and the general velocity distribution of halo clouds is consistent with an origin from gas injected into the halo by a Galactic fountain. For this case, two-phase models require that the abundance of very small grains and PAHs in the fountain clouds must be similar to the standard abundances in the disk. C1 UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 80 TC 167 Z9 168 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 1995 VL 453 IS 2 BP 673 EP 684 DI 10.1086/176429 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TC992 UT WOS:A1995TC99200015 ER PT J AU APRILE, E CHUPP, EL BOLOTNIKOV, A DUNPHY, PP AF APRILE, E CHUPP, EL BOLOTNIKOV, A DUNPHY, PP TI DETERMINATION OF THE GALACTIC AL-26 SOURCE DISTRIBUTION WITH A NOVEL IMAGING TELESCOPE SO ASTROPHYSICAL JOURNAL LA English DT Article DE GAMMA RAYS, OBSERVATIONS; INSTRUMENTATION, DETECTORS; TELESCOPES ID GAMMA-RAY LINE; CODED-APERTURE TELESCOPE; LIQUID XENON TPC; INTERSTELLAR-MEDIUM; ANGULAR-DISTRIBUTION; IONIZATION-CHAMBER; RADIOACTIVE AL-26; MASSIVE STARS; CENTER REGION; X-RAY AB An instrument is described which will provide a direct image of gamma-ray line or continuum sources in the energy range 300 keV-10 MeV. We illustrate the use of this instrument to study the celestial distribution of the Al-26 isotope by observing the 1.809 MeV de-excitation gamma-ray line. The source location accuracy is 2' or better. The imaging telescope is a liquid xenon time projection chamber coupled with a coded aperture mask (LXeCAT). This instrument will confirm and extend the COMPTEL observations from the Compton Gamma Ray Observatory (CGRO) with an improved capability for identifying the actual Galactic source or sources of Al-26, which are currently not known with certainty. Sources currently under consideration include red giants on the asymptotic giant branch, novae, Type Ib or Type II supernovae, Wolf-Rayet stars, and cosmic rays interacting in molecular clouds. The instrument could also identify a local source of the celestial 1.809 MeV gamma-ray line, such as a recent nearby supernova. C1 COLUMBIA UNIV,COLUMBIA ASTROPHYS LAB,NEW YORK,NY 10027. UNIV NEW HAMPSHIRE,DEPT PHYS,DURHAM,NH 03824. UNIV NEW HAMPSHIRE,INST STUDY EARTH OCEANS & SPACE,DURHAM,NH 03824. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP APRILE, E (reprint author), COLUMBIA UNIV,DEPT PHYS,538 W 120TH ST,NEW YORK,NY 10027, USA. NR 76 TC 5 Z9 5 U1 1 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 1995 VL 453 IS 2 BP 685 EP 696 DI 10.1086/176430 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TC992 UT WOS:A1995TC99200016 ER PT J AU ELLISON, DC BARING, MG JONES, FC AF ELLISON, DC BARING, MG JONES, FC TI ACCELERATION RATES AND INJECTION EFFICIENCIES IN OBLIQUE SHOCKS SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCELERATION OF PARTICLES; COSMIC RAYS; SHOCK WAVES; TURBULENCE ID QUASI-PARALLEL SHOCKS; ENERGY COSMIC-RAYS; PARTICLE-ACCELERATION; MAGNETIC-FIELD; ASTROPHYSICAL SHOCKS; MAXIMUM ENERGY; RE-FORMATION; BOW SHOCK; SIMULATIONS; WAVES AB The rate at which particles are accelerated by the first-order Fermi mechanism in shocks depends on the angle, Theta(Bn1), that the upstream magnetic field makes with the shock normal. The greater the obliquity, the greater the rate, and in quasi-perpendicular shocks (i.e., Theta(Bn1) --> 90 degrees), rates can be hundreds of times higher than those seen in parallel shocks. In many circumstances pertaining to evolving shocks (e.g., supernova blast waves and interplanetary traveling shocks) or where acceleration competes with losses (e.g., through synchrotron cooling), high acceleration rates imply high maximum particle energies, and obliquity effects may have important astrophysical consequences. However, as is demonstrated in this paper, the efficiency for injecting thermal particles into the acceleration mechanism also depends strongly on obliquity and, in general, varies inversely with Theta(Bn1); shocks which accelerate particles most rapidly are least capable of injecting thermal particles into the acceleration process. In addition, the degree of turbulence and the resulting cross-field diffusion strongly influences both injection efficiency and acceleration rates. The test particle Monte Carlo simulation of shock acceleration used here assumes large-angle scattering, computes particle orbits exactly in shocked, laminar, nonrelativistic flows (in contrast to our previous simulations of oblique shocks, which assumed magnetic moment conservation), and calculates the injection efficiency as a function of obliquity, Mach number, and degree of turbulence. We find that turbulence must be quite strong for high Mach number, highly oblique shocks to inject significant numbers of thermal particles and that only modest gains in acceleration rates can be expected for strong oblique shocks over parallel ones if the only source of seed particles is the thermal background. C1 NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20711. RP ELLISON, DC (reprint author), N CAROLINA STATE UNIV,DEPT PHYS,BOX 8202,RALEIGH,NC 27695, USA. NR 47 TC 120 Z9 120 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 1995 VL 453 IS 2 BP 873 EP 882 DI 10.1086/176447 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TC992 UT WOS:A1995TC99200033 ER PT J AU NG, CK REAMES, DV AF NG, CK REAMES, DV TI PITCH-ANGLE DIFFUSION-COEFFICIENT IN AN EXTENDED QUASI-LINEAR THEORY SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCELERATION OF PARTICLES; DIFFUSION; INTERPLANETARY MEDIUM; MHD; SUN, PARTICLE EMISSION ID RANDOM MAGNETIC-FIELDS; COSMIC-RAY TRANSPORT; GYRORESONANT ELECTRON ACCELERATION; CHARGED-PARTICLE TRANSPORT; LOW-BETA PLASMA; ENERGETIC PARTICLES; SOLAR-WIND; SCATTERING; WAVES; FLUCTUATIONS AB Using an extended quasi-linear theory that takes account of the distribution of medium-scale background interplanetary magnetic field, we calculate the pitch angle diffusion coefficients of interplanetary energetic ions, for a slab turbulence model consisting of a superposition of parallel and antiparallel transverse R and L waves. Our results show that the background variation broadens the resonance function significantly at pitch angles near 90 degrees, so that protons down to approximate to 25 keV interact with hydromagnetic waves at all pitch angles, and the steepening of the magnetic field power spectrum in the dissipation range does not result in a resonance gap or infinite scattering mean free path. RP NG, CK (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,CODE 661,GREENBELT,MD 20771, USA. NR 44 TC 28 Z9 28 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 1995 VL 453 IS 2 BP 890 EP 905 DI 10.1086/176449 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TC992 UT WOS:A1995TC99200035 ER PT J AU SINGH, KP SZKODY, P BARRETT, P WHITE, NE FIERCE, E SILBER, A HOARD, DW HAKALA, PJ PIIROLA, V SOHL, K AF SINGH, KP SZKODY, P BARRETT, P WHITE, NE FIERCE, E SILBER, A HOARD, DW HAKALA, PJ PIIROLA, V SOHL, K TI A NEW MAGNETIC CATACLYSMIC VARIABLE - WGA J1047.1+6335 SO ASTROPHYSICAL JOURNAL LA English DT Article DE NOVAE, CATACLYSMIC VARIABLES; STARS, INDIVIDUAL (WGA J1047.1+6335); STARS, VARIABLES, OTHER; X-RAYS, STARS ID INTERSTELLAR AB A new ultrasoft X-ray source, WGA J1047.1+6335, was discovered during a search of the ROSAT PSPC pointed observations, data from which are publicly available (White, Giommi, & Angelini; Singh et al.). We identify the X-ray source with an optical object of V similar or equal to 19.4 mag in the error circle of the X-ray source position. Optical and X-ray photometry has revealed the presence of an similar to 40 minute period. Strong emission lines of H and He have been detected in its optical spectrum. The X-ray spectrum of WGA J1047.1+6335 is best fitted with a blackbody (kT similar or equal to 40-50 eV) with negligible interstellar absorption and no X-rays with energies greater than 0.5 keV. Polarimetry shows a high amplitude (20% circular polarization) variation on an 80 minute timescale. These properties all suggest a polar with an 80 minute orbital period and either beaming/self-eclipsing effects from one pole or nearly equal emission from two poles. C1 UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. UNIV OXFORD,ASTROPHYS & NUCL PHYS LAB,OXFORD OX1 3RH,ENGLAND. TUORLA OBSERV,SF-21500 PIIKKIO,FINLAND. UNIV LEICESTER,DEPT PHYS,XRAY ASTRON GRP,LEICESTER LE1 7RH,LEICS,ENGLAND. RP SINGH, KP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,LHEA,CODE 668,GREENBELT,MD 20771, USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 11 TC 6 Z9 6 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 1995 VL 453 IS 2 BP L95 EP L98 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TC993 UT WOS:A1995TC99300011 ER PT J AU YAQOOB, T EDELSON, R WEAVER, KA WARWICK, RS MUSHOTZKY, RF SERLEMITSOS, PJ HOLT, SS AF YAQOOB, T EDELSON, R WEAVER, KA WARWICK, RS MUSHOTZKY, RF SERLEMITSOS, PJ HOLT, SS TI THE IRON K-ALPHA LINE-PROFILE IN NGC-4151 SO ASTROPHYSICAL JOURNAL LA English DT Article DE BLACK HOLE PHYSICS; GALAXIES, ACTIVE; GALAXIES, INDIVIDUAL (NGC 4151); LINE, PROFILES; X-RAYS, GALAXIES ID X-RAY REFLECTION; COLD MATTER; NGC-4151; GALAXIES; NUCLEI; DISK AB We present the first measurements of the Fe K alpha line profile in NGC 4151 from ASCA observations performed in 1993 May, November, and December. The apparent line profile is asymmetric, consisting of a peak at similar to 6.3-6.4 keV, a sharp drop on the blue side below similar to 7 keV, and a broad red wing extending to similar to 4-5 keV. This first clear indication of complex structure confirms earlier tentative measurements of the Fe-K region with the Broad Band X-Ray Telescope (BBXRT). The line intensity, equivalent width, and detailed shape are model dependent. Interpretation of the profile in terms of emission from a disk rotating around a central black hole strongly constrains the putative disk to be face on, but this contradicts the current body of knowledge of the geometry of this source. If the apparent red wing is not in fact part of a peculiar continuum, then a face-on disk may be allowed only if the collimated structure observed at the parsec scale is misaligned with respect to the disk normal by at least 20 degrees and iron is overabundant by a factor of similar to 2, with some additional caveats. Alternatively, a different geometry of line-emitting material may be required. In contrast to clear variability in the soft X-ray line emission below similar to 1 keV between the observations, these data show no significant variability of the Fe K alpha overall line shape, intensity, or equivalent width. C1 PENN STATE UNIV,DEPT ASTRON & ASTROPHYS,DAVEY LAB 525,UNIVERSITY PK,PA 16802. UNIV LEICESTER,DEPT PHYS & ASTRON,LEICESTER LE1 7RH,LEICS,ENGLAND. RP YAQOOB, T (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. NR 26 TC 18 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 1995 VL 453 IS 2 BP L81 EP L85 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TC993 UT WOS:A1995TC99300008 ER PT J AU LUNDGREN, P SAUCIER, F PALMER, R LANGON, M AF LUNDGREN, P SAUCIER, F PALMER, R LANGON, M TI ALASKA CRUSTAL DEFORMATION - FINITE-ELEMENT MODELING CONSTRAINED BY GEOLOGIC AND VERY LONG-BASE-LINE INTERFEROMETRY DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID YAKATAGA SEISMIC GAP; STRAIN ACCUMULATION; SOUTHERN ALASKA; FAULT SYSTEM; DENALI-FAULT; PACIFIC; MOTION; FAIRWEATHER; CALIFORNIA; TECTONICS AB We compute crustal motions in,Alaska by calculating the finite element solution for an elastic spherical shell problem. The method we use allows the finite element mesh to include faults and very long baseline interferometry (VLBI) baseline rates df change. Boundary conditions include Pacific-North American (PA-NA) plate motions. The solutionis constrained by the oblique orientation of the Fairweather-Queen Charlotte strike-slip faults relative to the PA-NA relative motion direction and the oblique orientation from normal convergence of the eastern Aleutian trench fault systems, as well as strike-slip motion along the Denali and Totschunda fault systems. We explore the effects that a range of fault slip constraints and weighting of VLBI rates of change has on the solution. This allows us to test the motion on faults, such as the Denali fault where there are conflicting reports on its present-day slip rate. We find a pattern of displacements which produce fault motions generally consistent with geologic observations. The motion of the continuum has the general pattern of radial movement of crust to the NE away from the Fairweather-Queen Charlotte fault systems in SE Alaska and Canada. This pattern of crustal motion is absorbed across the Mackenzie Mountains in NW Canada, with strike-slip motion constrained along the Denali and Tintina fault systems. In south central Alaska and the Alaska forearc oblique convergence at the eastern Aleutian trench and the strike-slip motion of the Denali fault system produce a counterclockwise pattern of motion which is partially absorbed along the Contact and related fault systems in southern Alaska and is partially extruded into the Bering Sea and into the forearc parallel the Aleutian trench from the Alaska Peninsula westward. Rates of motion and fault slip are small in western and northern Alaska, but the motions we compute are consistent with the senses of strike-slip motion inferred geologically along the Kaltag, Kobuk Trench, and Thompson Creek faults and with the normal faulting observed in NW Alaska near Nome. The nonrigid behavior of our finite element solution produces patterns of motion that would not have been expected from rigid block models: strike-slip faults can exist in a continuum that has motion mostly perpendicular to their strikes, and faults can exhibit along-strike differences in magnitudes and directions. C1 UNIV OREGON, DEPT GEOL SCI, EUGENE, OR 97403 USA. INST MAURICE LAMONTAGNE, MONT JOLI, PQ G5H 3Z4, CANADA. RP LUNDGREN, P (reprint author), CALTECH, JET PROPULS LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 35 TC 25 Z9 25 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD NOV 10 PY 1995 VL 100 IS B11 BP 22033 EP 22045 DI 10.1029/95JB00237 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TE225 UT WOS:A1995TE22500003 ER PT J AU CANDE, SC RAYMOND, CA STOCK, J HAXBY, WF AF CANDE, SC RAYMOND, CA STOCK, J HAXBY, WF TI GEOPHYSICS OF THE PITMAN FRACTURE-ZONE AND PACIFIC-ANTARCTIC PLATE MOTIONS DURING THE CENOZOIC SO SCIENCE LA English DT Article ID RELATIVE MOTIONS; SOUTH-PACIFIC; HOTSPOT TRACKS; INDIAN-OCEAN; ATLANTIC; UNCERTAINTIES; EVOLUTION; HISTORY; TECTONICS; AUSTRALIA AB Multibeam bathymetry and magnetometer data from the Pitman fracture zone (FZ) permit construction of a plate motion history for the South Pacific over the past 65 million years. Reconstructions show that motion between the Antarctic and Bellingshausen plates was smaller than previously hypothesized and ended earlier, at chron C27 (61 million years ago). The fixed hot-spot hypothesis and published paleomagnetic data require additional motion elsewhere during the early Tertiary, either between East Antarctica and West Antarctica or between the North and South Pacific. A plate reorganization at chron C27 initiated the Pitman FZ and may have been responsible for the other right-stepping fracture zones along the ridge. An abrupt (8 degrees) clockwise rotation in the abyssal hill fabric along the Pitman flowline near the young end of chron C3a (5.9 million years ago) dates the major change in Pacific-Antarctic relative motion in the late Neogene. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. CALTECH,SEISMOL LAB,PASADENA,CA 91125. LAMONT DOHERTY EARTH OBSERV,PALISADES,NY 10964. RP CANDE, SC (reprint author), SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. OI Stock, Joann Miriam/0000-0003-4816-7865 NR 58 TC 172 Z9 172 U1 1 U2 9 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 10 PY 1995 VL 270 IS 5238 BP 947 EP 953 DI 10.1126/science.270.5238.947 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TD878 UT WOS:A1995TD87800037 ER PT J AU MONKS, PS STIEF, LJ TARDY, DC LIEBMAN, JF ZHANG, ZY KUO, SC KLEMM, RB AF MONKS, PS STIEF, LJ TARDY, DC LIEBMAN, JF ZHANG, ZY KUO, SC KLEMM, RB TI DISCHARGE FLOW-PHOTOIONIZATION MASS-SPECTROMETRIC STUDY OF HOI - PHOTOIONIZATION EFFICIENCY SPECTRUM AND IONIZATION-ENERGY SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PHOTOELECTRON-SPECTROSCOPY; EXCITED MOLECULES; KINETICS; OH; RADICALS; RELAXATION; IODINE; 298-K; I-2 AB Photoionization efficiency (PIE) spectra of HOI were measured over the wavelength range lambda = 115-130 nm and in the ionization threshold region, lambda = 123-129 nm, using a discharge flow-photoionization mass spectrometer apparatus coupled to a synchrotron radiation source. HOI was generated, in situ but in varying amounts, by three separate reactions: OH + I-2; OH + CF3I; O(P-3) + C2H5I. The PIE spectra displayed steplike behavior near threshold, and the HO-I stretching frequency in the cation was determined to be 702 +/- 60 cm(-1). A value of (9.81(1) +/- 0.02(0)) eV was obtained for the adiabatic ionization energy (IE) of HOI from photoion thresholds, corresponding to the HOI+(X(2)A '') <-- HOI(X(l)A') transition. Even though the present result appears to be the first reported determination of IE(HOI), the experimental value is compared to an estimated value previously derived via a trend analysis and it is considered in terms of trends in the series IE(HOX), where X = F, Cl, Br, and I. The branching ratio for [HOI]/[IO] in the O(P-3) + C2H5I reaction was estimated to be about 8/1 at T = 298 K if we assume that the photoionization efficiencies for HOI and IO are the same at 10.3 eV (lambda = 120 nm). Also, based on the value for IE(HOI) derived in the present study, a value for IE(IO) approximate to 9.66 +/- 0.10 eV has been predicted. C1 NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. UNIV IOWA,DEPT CHEM,IOWA CITY,IA 52242. UNIV MARYLAND,DEPT CHEM & BIOCHEM,BALTIMORE,MD 21228. BROOKHAVEN NATL LAB,UPTON,NY 11973. RI Monks, Paul/H-6468-2016 OI Monks, Paul/0000-0001-9984-4390 NR 43 TC 32 Z9 32 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA PO BOX 57136, WASHINGTON, DC 20037-0136 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 9 PY 1995 VL 99 IS 45 BP 16566 EP 16570 DI 10.1021/j100045a013 PG 5 WC Chemistry, Physical SC Chemistry GA TD900 UT WOS:A1995TD90000013 ER PT J AU YEOMANS, D AF YEOMANS, D TI IMPACT JUPITER - THE CRASH OF COMET SHOEMAKER-LEVY-9 - LEVY,DH SO NATURE LA English DT Book Review RP YEOMANS, D (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 1 TC 1 Z9 1 U1 0 U2 2 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 9 PY 1995 VL 378 IS 6553 BP 142 EP 142 DI 10.1038/378142a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TD759 UT WOS:A1995TD75900039 ER PT J AU YEOMANS, D AF YEOMANS, D TI THE GREAT COMET CRASH - THE COLLISION OF COMET SHOEMAKER-LEVY-9 AND JUPITER - SPENCER,JR, MITTON,J SO NATURE LA English DT Book Review RP YEOMANS, D (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 1 TC 1 Z9 1 U1 0 U2 2 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 9 PY 1995 VL 378 IS 6553 BP 142 EP 142 DI 10.1038/378142a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TD759 UT WOS:A1995TD75900040 ER PT J AU HUANG, ZC GOLDBERG, R CHEN, JC ZHENG, YD MOTT, DB SHU, P AF HUANG, ZC GOLDBERG, R CHEN, JC ZHENG, YD MOTT, DB SHU, P TI DIRECT OBSERVATION OF TRANSFERRED-ELECTRON EFFECT IN GAN SO APPLIED PHYSICS LETTERS LA English DT Article ID GALLIUM NITRIDE AB We report the direct observation of transferred-electron effect in unintentionally doped GaN epilayers grown by metalorganic chemical vapor deposition. The negative differential resistivity (NDR) was observed from the current-electric field characteristics in GaN using a metal-semiconductor-metal (M-S-M) system. The threshold field for the onset of NDR was independent of the spacing of M-S-M fingers, and was measured to be 1.91 x 10(5) V/cm for GaN with an n-type carrier concentration of 10(14) cm(-3). This value is very close to the value obtained with an n-type carrier concentration of 10(14) cm from theoretical simulation. This observation is an experimental evidence of transferred-electron effects in GaN, which is important in understanding GaN energy band structure and in the application of Gunn-effect devices using GaN materials. (C) 1995 American Institute of Physics. C1 UNIV MARYLAND,DEPT ELECT ENGN,CATONSVILLE,MD 21228. HUGHES STX CORP,GREENBELT,MD 20770. NANJING UNIV,DEPT PHYS,NANJING 210008,PEOPLES R CHINA. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 8 TC 34 Z9 34 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 6 PY 1995 VL 67 IS 19 BP 2825 EP 2826 DI 10.1063/1.114797 PG 2 WC Physics, Applied SC Physics GA TC985 UT WOS:A1995TC98500025 ER PT J AU HEIM, KR HEMBREE, GG SCHMIDT, KE SCHEINFEIN, MR AF HEIM, KR HEMBREE, GG SCHMIDT, KE SCHEINFEIN, MR TI ENHANCED SUPERPARAMAGNETISM IN 2-DIMENSIONAL ARRAYS OF NANOMETER-SIZED FE ISLANDS SO APPLIED PHYSICS LETTERS LA English DT Article ID CAF2/SI(111); PARTICLES AB Iron grown on room-temperature CaF2/Si(111) substrates form two-dimensional arrays of nanometer-sized superparamagnetic islands. Deposition of Ag on the Fe/CaF2/Si(111) produced a superparamagnetic response where the effective moment was proportional to the number of Fe islands covered by an average-sized Ag island. The nonmagnetic Ag overlayer mediates a long-range exchange between neighboring Fe islands within an individual Ag island. Monte Carlo methods are used to examine ordering in two dimensions and to set minimum interisland coupling strengths. (C) 1995 American Institute of Physics. C1 ARIZONA STATE UNIV,DEPT PHYS & ASTRON,TEMPE,AZ 85287. RP HEIM, KR (reprint author), CALTECH,JET PROP LAB,M-S 300-329,PASADENA,CA 91109, USA. NR 17 TC 14 Z9 14 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 6 PY 1995 VL 67 IS 19 BP 2878 EP 2880 DI 10.1063/1.114815 PG 3 WC Physics, Applied SC Physics GA TC985 UT WOS:A1995TC98500043 ER PT J AU MUMMA, MJ AF MUMMA, MJ TI SPACE LASER SO SCIENCE LA English DT Letter ID HETERODYNE SPECTROSCOPY; NATURAL LASER; VENUS; THERMOSPHERE; MARS RP MUMMA, MJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771, USA. RI mumma, michael/I-2764-2013 NR 15 TC 0 Z9 0 U1 0 U2 3 PU AMER ASSOC ADVAN SCIENCE PI WASHINGTON PA 1333 H ST NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 3 PY 1995 VL 270 IS 5237 BP 717 EP 717 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TC712 UT WOS:A1995TC71200002 ER PT J AU MIELKE, SL TRUHLAR, DG SCHWENKE, DW AF MIELKE, SL TRUHLAR, DG SCHWENKE, DW TI QUANTUM PHOTOCHEMISTRY - THE COMPETITION BETWEEN ELECTRONICALLY NONADIABATIC REACTION AND ELECTRONIC-TO-VIBRATIONAL, ROTATIONAL, TRANSLATIONAL ENERGY-TRANSFER IN BR-ASTERISK COLLISIONS WITH H-2 SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID STATE TRANSITION-PROBABILITIES; CHEMICAL-REACTIONS; SCATTERING-THEORY; REPRESENTATIONS; ACCURATE; DYNAMICS; SURFACES; SYSTEM; F(P-2); MODEL AB Electronic-to-vibrational energy transfer and nonadiabatic chemical reaction from an electronically excited reagent are studied by accurate quantum dynamics calculations for Br* + H-2 --> HBr + H or Br + H-2, where an asterisk denotes electronic excitation, and the lack of an asterisk denotes the electronic ground state. We present details of the formalism for calculating the scattering matrix in a diabatic representation in which the coupling between potential energy surfaces does not vanish asymptotically. The inelastic results are discussed in terms of the translational energy gap, which is often assumed to be a dominant factor in electronic-to-vibrational-rotational energy transfer. The quenching of Br* by H-2 produces principally H-2 with one quantum of vibrational excitation; this process satisfies a near-resonance condition for electronic-to-vibrational energy transfer. Reaction to produce HBr is the next most likely branching pathway, followed by rotational translational energy transfer. Examination of the rotational distributions of each final vibrational level shows that the rotational states nearest to resonance are not the most heavily populated; i.e., the resonance condition is more important for vibration than for rotation. The reactive results are discussed in terms of the relative efficiencies of various forms of reagent energy in overcoming the endoergicity and intrinsic barrier to reaction. C1 UNIV MINNESOTA, DEPT CHEM, CHEM PHYS PROGRAM, MINNEAPOLIS, MN 55455 USA. UNIV MINNESOTA, INST SUPERCOMP, MINNEAPOLIS, MN 55455 USA. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RI Mielke, Steven/B-7533-2008; schwenke, david/I-3564-2013; Truhlar, Donald/G-7076-2015 OI Mielke, Steven/0000-0002-1938-7503; Truhlar, Donald/0000-0002-7742-7294 NR 61 TC 47 Z9 47 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 2 PY 1995 VL 99 IS 44 BP 16210 EP 16216 DI 10.1021/j100044a003 PG 7 WC Chemistry, Physical SC Chemistry GA TD478 UT WOS:A1995TD47800003 ER PT J AU SINGH, HB KANAKIDOU, M CRUTZEN, PJ JACOB, DJ AF SINGH, HB KANAKIDOU, M CRUTZEN, PJ JACOB, DJ TI HIGH-CONCENTRATIONS AND PHOTOCHEMICAL FATE OF OXYGENATED HYDROCARBONS IN THE GLOBAL TROPOSPHERE SO NATURE LA English DT Article ID ORGANIC-COMPOUNDS; ATMOSPHERE; CHEMISTRY; EMISSIONS AB OXYGENATED species in the atmosphere are important sources of free radicals and are intricately linked with the fate of nitrogen oxides (NOx), which are themsel es necessary for tropospheric ozone formation(1,2). With the exception of formaldehyde, oxygenated hydrocarbons have rarely been measured in the free troposphere. Here we report airborne measurements indicating the presence of high concentrations (compared to those of routinely measured C-2-C-6 tropospheric hydrocarbons(3,4)) of acetone and methanol. We use a three-dimensional model to show that acetone photochemistry provides a quantitatively significant (up to 50%) pathway for sequestering NOx in the form of peroxyacetylnitrate, a relatively unreactive temporary reservoir of NOx. Furthermore, in the dry regions of the upper troposphere, acetone can provide a large primary source of HOx (OH + HO2) radicals, resulting in increased ozone production. This surprisingly significant contribution of such oxygenated hydrocarbons to tropospheric NOx, HOx and ozone cycling is likely to be affected by their changing natural and anthropogenic emissions due to land-use change, biomass burning and alcohol-based biofuel use. C1 CEA,CNRS,CTR FAIBLES RADIOACTIV,F-91198 GIF SUR YVETTE,FRANCE. MAX PLANCK INST CHEM,D-55020 MAINZ,GERMANY. HARVARD UNIV,CAMBRIDGE,MA 02138. RP SINGH, HB (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. RI Kanakidou, Maria/D-7882-2012; Crutzen, Paul/F-6044-2012 OI Kanakidou, Maria/0000-0002-1724-9692; NR 26 TC 426 Z9 435 U1 4 U2 42 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 2 PY 1995 VL 378 IS 6552 BP 50 EP 54 DI 10.1038/378050a0 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TC469 UT WOS:A1995TC46900045 ER PT J AU Yip, LP vanDam, CP Whitehead, JH Hardin, JD Miley, SJ Potter, RC Bertelrud, A Edge, DC Willard, PE AF Yip, LP vanDam, CP Whitehead, JH Hardin, JD Miley, SJ Potter, RC Bertelrud, A Edge, DC Willard, PE TI The NASA B737-100 high-lift flight research programme - Measurements and computations SO AERONAUTICAL JOURNAL LA English DT Article AB The aerodynamic performance of a multi-element high-lift system has a critical influence oil the direct operating cost of a subsonic civil transport aircraft, A thorough understanding of the aerodynamic characteristics of these multi-element aerofoils and wings allows aircraft companies to design and build more competitive aircraft with high-lift systems that are less complex and lighter for given high-lift performance or that have improved lift and drag characteristics for given system complexity and weight. Flight experiments on NASA Langley's B737-100 aircraft have been conducted to further enhance the understanding of the complex Bows about multielement high-lift systems at full-scale flight conditions. In this paper, an overview of the flight program is provided, followed by highlights of experimental results and computational analysis. Measurements included surface pressures on the slats, main element and flap elements using flush pressure ports and pressure belts, surface shear stresses using Preston tubes, off-surface velocity distributions using boundary layer/wake rakes, aeroelastic deformations of the flap elements using an optical positioning system, and boundary layer transition detection using hot-film anemometers and an infrared imaging system. Boundary layer transition measurements on the slat using hot-film sensors are correlated with the flow visualisation results from an infrared imaging technique. Extensive application of several computational techniques and comparisons with flight measurements are shown for a limited number of cases. This program has generated an extensive set of data, much of which are still being analysed. RP Yip, LP (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 0 TC 5 Z9 5 U1 1 U2 2 PU ROYAL AERONAUTICAL SOC PI LONDON PA 4 HAMILTON PL, LONDON, ENGLAND W1V OBQ SN 0001-9240 J9 AERONAUT J JI Aeronaut. J. PD NOV PY 1995 VL 99 IS 989 BP 372 EP 386 PG 15 WC Engineering, Aerospace SC Engineering GA TK738 UT WOS:A1995TK73800003 ER PT J AU Allen, ER Ming, DW Hossner, LR Henninger, DL Galindo, C AF Allen, ER Ming, DW Hossner, LR Henninger, DL Galindo, C TI Growth and nutrient uptake of wheat in clinoptilolite-phosphate rock substrates SO AGRONOMY JOURNAL LA English DT Article ID EXCHANGE; MIXTURES AB Mixtures of zeolite and phosphate rock react to release cations and anions into soil solution through dissolution and ion exchange. These mixtures have the potential to serve as slow-release sources of nutrients in synthetic soils. The term zeoponics has been used to describe such systems. Research was conducted to monitor dry matter production and nutrient uptake of wheat (Triticum aestivum L.) in a zeoponic system containing phosphate rock and NH4- and K-saturated zeolite. The objective was to evaluate the ability of zeolite and phosphate rock to provide a balanced supply of N, P, K, and Ca for plant growth. Two zeolite samples (San Miguel and Wyoming clinoptilolite) and two phosphate rock samples (North Carolina and Tennessee phosphate rock) were combined factorially to form four zeoponic mixtures. A series of synthetic soils was formed by combining selected rates of each zeoponic mixture with acid-washed quartz sand. Zeoponic rates (ZR) were 1, 5, 10, 25, 50, 75, and 100% (v/v) of the synthetic soil. Pots were placed in a growth chamber after planting, and plants were harvested every 45 d for a 225-d period. Foliar spray supplied essential nutrients other than N, P, K, and Ca. High yields of wheat dry matter were produced through several cuttings when at least 25% of the synthetic soil was comprised of the zeoponic mixture and when the zeoponic mixture contained a high-reactivity phosphate rock (North Carolina). Tissue analyses suggested that K, and to a lesser extent N, limited wheat growth when ZR less than or equal to 10%. Calcium limited wheat growth at ZR > 10% when a low-reactivity phosphate rock (Tennessee) was used, but not when a high-reactivity phosphate rock (North Carolina) was used. Properly formulated zeoponic mixtures of San Miguel or wyoming clinoptilolite and North Carolina phosphate rock are capable of supplying sufficient levels of N, P, K, and Ca for intensive growth of wheat. C1 OKLAHOMA STATE UNIV,DEPT AGRON,STILLWATER,OK 74078. TEXAS A&M UNIV,DEPT SOIL & CROP SCI,COLLEGE STN,TX 77840. NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. LOCKHEED ENGN & SCI CO,HOUSTON,TX 77058. NR 28 TC 29 Z9 31 U1 0 U2 0 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0002-1962 J9 AGRON J JI Agron. J. PD NOV-DEC PY 1995 VL 87 IS 6 BP 1052 EP 1059 PG 8 WC Agronomy SC Agriculture GA TL690 UT WOS:A1995TL69000004 ER PT J AU HIXON, R SHIH, SH MANKBADI, RR AF HIXON, R SHIH, SH MANKBADI, RR TI EVALUATION OF BOUNDARY-CONDITIONS FOR COMPUTATIONAL AEROACOUSTICS SO AIAA JOURNAL LA English DT Article ID HYPERBOLIC SYSTEMS AB The performance of three acoustic boundary condition formulations is investigated by computing a test problem with a known analytic solution. By using a fixed grid and time step, all variations in the solution are due solely to the boundary condition. The effect of implementation differences on the performance of a given boundary condition is also studied. Details of all implementations are given. Results are shown for the acoustic field of a monopole in a uniform freestream. RP HIXON, R (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 12 TC 37 Z9 37 U1 0 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD NOV PY 1995 VL 33 IS 11 BP 2006 EP 2012 DI 10.2514/3.12940 PG 7 WC Engineering, Aerospace SC Engineering GA TD729 UT WOS:A1995TD72900002 ER PT J AU ABID, R RUMSEY, C GATSKI, T AF ABID, R RUMSEY, C GATSKI, T TI PREDICTION OF NONEQUILIBRIUM TURBULENT FLOWS WITH EXPLICIT ALGEBRAIC STRESS MODELS SO AIAA JOURNAL LA English DT Article ID REYNOLDS; CLOSURES AB An explicit algebraic stress equation, developed by Gatski and Speziale, is used in the framework of the K-omega and K-epsilon formulations to predict two-dimensional separated turbulent hows. The nonequilibrium effects are modeled through coefficients that depend nonlinearly on both rotational and irrotational strains. The proposed models were implemented in the Courant-Friedrichs-Lewy three-dimensional Navier-Stokes code. Comparisons with the experimental data are presented, which clearly demonstrate that explicit algebraic stress models improve the response of standard two-equation models to nonequilibrium effects. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. RP ABID, R (reprint author), HIGH TECHNOL CORP,HAMPTON,VA 23666, USA. NR 19 TC 43 Z9 44 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD NOV PY 1995 VL 33 IS 11 BP 2026 EP 2031 DI 10.2514/3.12943 PG 6 WC Engineering, Aerospace SC Engineering GA TD729 UT WOS:A1995TD72900005 ER PT J AU CATTAFESTA, LN IYER, V MASAD, JA KING, RA DAGENHART, JR AF CATTAFESTA, LN IYER, V MASAD, JA KING, RA DAGENHART, JR TI 3-DIMENSIONAL BOUNDARY-LAYER-TRANSITION ON A SWEPT WING AT MACH-3.5 SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 25th Fluid Dynamics Conference CY JUN 20-23, 1994 CL COLORADO SPRINGS, CO SP Amer Inst Aeronaut & Astronaut ID CURVATURE AB Transition on a swept-wing leading-edge model at Mach 3.5 is investigated. Surface pressure and temperature measurements are obtained in the NASA Langley Research Center Supersonic Low-Disturbance Tunnel. For one case, temperature-sensitive paint and a sublimating chemical are used to visualize surface flow features such as transition location, The experimental data are compared with 1) mean-flow results computed as solutions to the thin-layer Navier-Stokes equations and 2) N-factors obtained using the envelope e(N) method. The experimental and computational results compare favorably in most cases. In particular, N congruent to 13 correlates best with the observed transition location over a range of freestream unit Reynolds numbers and angles of attack. Computed traveling crossflow disturbances with frequencies of 40-60 kHz have the largest N factors, and the surface flow visualizations reveal smooth transition fronts with only faint evidence of stationary crossflow vortices. These results suggest that transition is probably dominated by traveling, rather than stationary, crossflow disturbances for the present model. C1 VIGYAN INC,HAMPTON,VA 23666. NASA,LANGLEY RES CTR,DIV FLUID MECH & ACOUST,FLOW MODELING & CONTROL BRANCH,HAMPTON,VA 23681. RP CATTAFESTA, LN (reprint author), HIGH TECHNOL CORP,28 RES DR,POB 7262,HAMPTON,VA 23666, USA. RI Cattafesta, Louis/A-9545-2015 OI Cattafesta, Louis/0000-0002-5767-3383 NR 34 TC 23 Z9 23 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD NOV PY 1995 VL 33 IS 11 BP 2032 EP 2037 DI 10.2514/3.12944 PG 6 WC Engineering, Aerospace SC Engineering GA TD729 UT WOS:A1995TD72900006 ER PT J AU ROGERS, SE AF ROGERS, SE TI COMPARISON OF IMPLICIT SCHEMES FOR THE INCOMPRESSIBLE NAVIER-STOKES EQUATIONS SO AIAA JOURNAL LA English DT Article ID UPWIND DIFFERENCING SCHEME; FLOW; SOLVERS AB For a computational flow simulation tool to be useful in a design environment, it must be very robust and efficient. To develop such a tool for incompressible flow applications, a number of different implicit schemes are compared for several two-dimensional flow problems in the current study. The schemes include Point-Jacobi relaxation, Gauss-Seidel line relaxation, incomplete lower-upper decomposition, and the generalized minimum residual method preconditioned with each of the three other schemes. The efficiency of the schemes is measured in terms of the computing time required to obtain a steady-state solution for the laminar Bow over a backward-facing step, the Bow over a NACA 4412 airfoil, and the flow over a three-element airfoil using overset grids. The flow solver used in the study is the INS2D code that solves the incompressible Navier-Stokes equations using the method of artificial compressibility and upwind differencing of the convective terms. The results show that the generalized minimum residual method preconditioned with the incomplete lower-upper factorization outperforms all other methods by at least a factor of 2. RP ROGERS, SE (reprint author), NASA,AMES RES CTR,DIV AERONAUT TECHNOL,DESIGN CYCLE TECHNOL BRANCH,MAIL STOP T27B-1,MOFFETT FIELD,CA 94035, USA. NR 22 TC 18 Z9 19 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD NOV PY 1995 VL 33 IS 11 BP 2066 EP 2072 DI 10.2514/3.12948 PG 7 WC Engineering, Aerospace SC Engineering GA TD729 UT WOS:A1995TD72900010 ER PT J AU COBURN, SP THAMPY, KG LANE, HW CONN, PS ZIEGLER, PJ COSTILL, DL MAHUREN, JD FINK, WJ PEARSON, DR SCHALTENBRAND, WE PAULY, TA TOWNSEND, DW LEBLANC, AD SMITH, SM AF COBURN, SP THAMPY, KG LANE, HW CONN, PS ZIEGLER, PJ COSTILL, DL MAHUREN, JD FINK, WJ PEARSON, DR SCHALTENBRAND, WE PAULY, TA TOWNSEND, DW LEBLANC, AD SMITH, SM TI PYRIDOXIC ACID EXCRETION DURING LOW VITAMIN-B-6 INTAKE, TOTAL FASTING, AND BED REST SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Article DE VITAMIN-B-6; FASTING; MICROGRAVITY; HUMANS; 4-PYRIDOXIC ACID ID PLASMA PYRIDOXAL; MUSCLE; 5'-PHOSPHATE; METABOLISM; PHOSPHORYLASE; RUN AB Vitamin B-6 metabolism in 10 volunteers during 21 d of total fasting was compared with results from 10 men consuming a diet low only in vitamin B-6 (1.76 mu mol/d) and with men consuming a normal diet during bed rest. At the end of the fast mean plasma concentrations of vitamin B-6 metabolites and urinary excretion of 4-pyridoxic acid tended to be higher in the fasting subjects than in the low-vitamin B-6 group. The fasting subjects lost approximate to 10% of their total vitamin B-6 pool and approximate to 13% of their body weight. The low-vitamin B-6 group lost only approximate to 4% of their vitamin B-6 pool. Compared with baseline, urinary excretion of pyridoxic acid was significantly increased during 17 wk of bed rest. There was no increase in pyridoxic acid excretion during a second 15-d bed rest study. These data suggest the possibility of complex interactions between diet and muscle metabolism that may influence indexes that are frequently used to assess vitamin B-6 status. C1 NASA,LYNDON B JOHNSON SPACE CTR,BIOMED OPERAT & RES BRANCH,HOUSTON,TX 77058. FT WAYNE STATE DEV CTR,DEPT BIOCHEM,FT WAYNE,IN. BALL STATE UNIV,DEPT NUTR,MUNCIE,IN 47306. BALL STATE UNIV,HUMAN PERFORMANCE LAB,MUNCIE,IN 47306. INDIANA UNIV PURDUE UNIV,DEPT MATH SCI,FT WAYNE,IN 46805. BAYLOR COLL MED,DEPT MED,HOUSTON,TX 77030. NR 24 TC 9 Z9 9 U1 0 U2 1 PU AMER SOC CLIN NUTRITION INC PI BETHESDA PA 9650 ROCKVILLE PIKE SUBSCRIPTIONS, RM L-2310, BETHESDA, MD 20814-3998 SN 0002-9165 J9 AM J CLIN NUTR JI Am. J. Clin. Nutr. PD NOV PY 1995 VL 62 IS 5 BP 979 EP 983 PG 5 WC Nutrition & Dietetics SC Nutrition & Dietetics GA TC135 UT WOS:A1995TC13500014 PM 7572745 ER PT J AU MORELLI, JP BUNTING, RJ COWLEY, SWH FARRUGIA, CJ FREEMAN, MP FRIISCHRISTENSEN, E JONES, GOL LESTER, M LEWIS, RV LUBR, H ORR, D PINNOCK, M REEVES, GD WILLIAMS, PJS YEOMAN, TK AF MORELLI, JP BUNTING, RJ COWLEY, SWH FARRUGIA, CJ FREEMAN, MP FRIISCHRISTENSEN, E JONES, GOL LESTER, M LEWIS, RV LUBR, H ORR, D PINNOCK, M REEVES, GD WILLIAMS, PJS YEOMAN, TK TI RADAR OBSERVATIONS OF AURORAL-ZONE FLOWS DURING A MULTIPLE-ONSET SUBSTORM SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article ID WESTWARD TRAVELING SURGE; TWO-DIMENSIONAL OBSERVATIONS; GROUND-BASED OBSERVATIONS; HIGH-LATITUDE IONOSPHERE; SOLAR-WIND CONTROL; ELECTRIC-FIELDS; MAGNETOSPHERIC SUBSTORMS; MAGNETIC OBSERVATIONS; GEOMAGNETIC-ACTIVITY; CURRENT SYSTEMS AB We present an analysis of ground magnetic field, ionospheric flow, geosynchronous particle, and interplanetary data during a multiple-onset substorm on 12 April 1988. Our principal results concern the modulations of the ionospheric flow which occur during the impulsive electrojet activations associated with each onset. During the first hour of the disturbance these take place every similar to 12.5 min and involve the formation of a new intense westward current filament in the premidnight sector, just poleward of the preexisting extended current system driven by the large-scale flow. These filaments are similar to 1 h MLT wide (similar to 600 km), and initially expand poleward to a width of similar to 300 km before contracting equatorward and coalescing with the preexisting current, generally leaving the latter enhanced in magnitude and/or expanded in latitude. Within the impulsive electrojets the flow is found to be suppressed to values 50-100 m s(-1) or less during the first few minutes, before surging equatorward at 0.5-1.0 km s (-1) during the phase of rapid coalescence. The implication is that the precipitation-induced Hall conductivity within the impulsive electrojet initially rises to exceed similar to 100 mho, before decaying over a few minutes. This value compares with Hall conductivities of similar to 20 mho in the quasi-steady current regions, and a few mho or less in the regions poleward of the electrojets and in the preonset ionosphere. Preliminary evidence has also been found that the flow surges propagate from midnight to the morning sector where they are associated with arrested equatorward motion or poleward contractions of the current system. These observations are discussed in terms of present theoretical paradigms of the global behaviour of fields and flows which occur during substorms. C1 UNIV LONDON IMPERIAL COLL SCI & TECHNOL,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. UNIV YORK,DEPT PHYS,YORK YO1 5DD,N YORKSHIRE,ENGLAND. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. BRITISH ANTARCTIC SURVEY,CAMBRIDGE CB3 0ET,ENGLAND. DANISH METEOROL INST,DK-2100 COPENHAGEN,DENMARK. UNIV LEICESTER,DEPT PHYS,LEICESTER LE1 7RH,LEICS,ENGLAND. UNIV COLL WALES,DEPT PHYS,ABERYSTWYTH SY23 3BZ,DYFED,WALES. TECH UNIV CAROLO WILHELMINA BRAUNSCHWEIG,D-38106 BRAUNSCHWEIG,GERMANY. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RI Yeoman, Timothy/L-9105-2014; Reeves, Geoffrey/E-8101-2011 OI Yeoman, Timothy/0000-0002-8434-4825; Reeves, Geoffrey/0000-0002-7985-8098 NR 63 TC 37 Z9 37 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0992-7689 J9 ANN GEOPHYS JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD NOV PY 1995 VL 13 IS 11 BP 1144 EP 1163 DI 10.1007/s005850050255 PG 20 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA TG061 UT WOS:A1995TG06100003 ER PT J AU Frainier, R Groleau, N Hazelton, L Colombano, S AF Frainier, R Groleau, N Hazelton, L Colombano, S TI Automated advisors for remote science experimentation SO APPLIED ARTIFICIAL INTELLIGENCE LA English DT Article AB This article details flight results from the Principal Investigator (PI)-in-a-Box project. The project is an attempt to understand the issues involved in building automated real-time advisory systems to improve the conduct of science in remote laboratory settings. This ir an important problem, as examples of these situations can be found throughout aerospace. A knowledge-bared approach is used to facilitate real-time reactions to experiment data as they are collected by a competent, but not expert, operator The system was flown on the Space Shuttle in October 1993. The PI-in-a-Box system was able to outperform humans in a variety of science-related tasks; including data integrity assurance, data analysis, and scientific model validation. C1 RECOM TECHNOL INC,SAN JOSE,CA. MIT,MAN VEHICLE LAB,BOSTON,MA. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP Frainier, R (reprint author), RED PEPPER SOFTWARE CO,1810 GATEWAY DR,SUITE 150,SAN MATEO,CA 94404, USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0883-9514 J9 APPL ARTIF INTELL JI Appl. Artif. Intell. PD NOV-DEC PY 1995 VL 9 IS 6 BP 645 EP 675 DI 10.1080/08839519508945493 PG 31 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA TK593 UT WOS:A1995TK59300005 ER PT J AU Rosi, IS AF Rosi, IS TI On pragmatism and politics in Thailand - Major General Chamlong Srimuang SO ASIAN SURVEY LA English DT Article RP Rosi, IS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU UNIV CALIF PRESS PI BERKELEY PA JOURNALS DEPT 2120 BERKELEY WAY, BERKELEY, CA 94720 SN 0004-4687 J9 ASIAN SURV JI Asian Surv. PD NOV PY 1995 VL 35 IS 11 BP 1042 EP 1054 DI 10.1525/as.1995.35.11.01p00715 PG 13 WC Area Studies SC Area Studies GA TP964 UT WOS:A1995TP96400006 ER PT J AU SCHOMBERT, JM PILDIS, RA EDER, JA OEMLER, A AF SCHOMBERT, JM PILDIS, RA EDER, JA OEMLER, A TI DWARF SPIRALS SO ASTRONOMICAL JOURNAL LA English DT Article ID VIRGO CLUSTER; SURFACE BRIGHTNESS; GALAXIES; CATALOG; LUMINOSITY; ATLAS AB We report the discovery of a new class of galaxies, dwarf spirals, that serve as a morphological extension to the Hubble sequence for dwarf galaxies. Although they have a similar morphology to their giant counterparts, the dwarf spirals (dS) are characterized by faint total luminosities (M(B)>-17), small diameters (R(26)<5 kpc), low central surface brightnesses mu(0)>24 B mag arcsec(-2)), and low HI masses (M(HI)less than or equal to 10(9) M.) Most of these dwarf spirals have flocculent or multiple arm spiral patterns, but some have smooth disks, similar in appearance to a dwarf SO's, yet are rich in neutral gas. The combination of small angular size and low surface brightness explains why this class of galaxies was missed in previous cluster catalogs and field surveys. Since cluster catalogs are complete to much fainter surface brightness and smaller angular limits than most galaxy catalogs, yet contain no dS galaxies, we conclude that dwarf spirals are only found in the held. (C) 1995 American Astronomical Society. C1 CALTECH,JET PROP LAB,CTR INFRARED PROC & ANAL,PASADENA,CA 91109. UNIV MICHIGAN,DEPT ASTRON,ANN ARBOR,MI 48109. NATL ASTRON & IONOSPHERE CTR,ARECIBO OBSERV,ARECIBO,PR 00613. YALE UNIV,DEPT ASTRON,NEW HAVEN,CT 06511. NR 27 TC 41 Z9 41 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD NOV PY 1995 VL 110 IS 5 BP 2067 EP 2074 DI 10.1086/117669 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TB502 UT WOS:A1995TB50200007 ER PT J AU DESERT, FX JENNISKENS, P DENNEFELD, M AF DESERT, FX JENNISKENS, P DENNEFELD, M TI DIFFUSE INTERSTELLAR BANDS AND UV EXTINCTION CURVES - THE MISSING LINK SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE DUST, EXTINCTION; ISM, MOLECULES; ISM, ABUNDANCES ID POLYCYCLIC AROMATIC-HYDROCARBONS; ULTRAVIOLET EXTINCTION; FAR-ULTRAVIOLET; FEATURES; EMISSION; SHAPES; ABSORPTION; GRAINS; CARRIERS; 4430-A AB The connection between diffuse interstellar bands and components of the interstellar ultraviolet extinction curve, decomposed according to the Fitzpatrick & Massa scheme, is analysed from new observations of several DIBs in the line of sight to 28 stars measured by IUE. We find that the strength of the 217.5 nm bump positively correlates with DIB strength, whereas correlations with a negative slope exist with the FUV non-linear rise and the width of the bump. There is no correlation with linear rise. The relation of bump height versus DIB strength does not pass through zero. The results are interpreted within the polycyclic aromatic hydrocarbon (PAH) framework. They strengthen the hypothesis that the FUV non-linear rise is produced by neutral PAHs, whereas DIB carriers are found among some ionised or radical PAHs. C1 HUYGENS LAB, ASTROPHYS LAB, 2300 RA LEIDEN, NETHERLANDS. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. INST ASTROPHYS PARIS, F-75014 PARIS, FRANCE. RP DESERT, FX (reprint author), UNIV PARIS 11, INST ASTROPHYS SPATIALE, BAT 121, F-91405 ORSAY, FRANCE. NR 57 TC 18 Z9 18 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 1995 VL 303 IS 1 BP 223 EP 232 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TE383 UT WOS:A1995TE38300025 ER PT J AU BIRD, CM MUSHOTZKY, RF METZLER, CA AF BIRD, CM MUSHOTZKY, RF METZLER, CA TI THE VELOCITY DISPERSION-TEMPERATURE CORRELATION FROM A LIMITED CLUSTER SAMPLE SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, CLUSTERS, GENERAL; GALAXIES, KINEMATICS AND DYNAMICS; X-RAYS, GALAXIES ID X-RAY; INTRACLUSTER GAS; DARK MATTER; GALAXIES; COMA AB Most studies of correlations between X-ray and optical properties of galaxy clusters have used the largest samples of data available, regardless of the morphological types of clusters included. Given the increasing evidence that morphology is related to a cluster's degree of dynamical evolution, we approach the study of X-ray and optical correlations differently. We evaluate the relationship between velocity dispersion and temperature for a limited set of galaxy clusters taken from Bird (1994) which all possess dominant central galaxies and which have been explicitly corrected for the presence of substructure. We find that sigma, proportional to T-0.61+/-0.13. We use a Monte Carlo computer routine to estimate the significance of this deviation from the sigma(r) proportional to T-0.5 relationship predicted by the virial theorem. We find that the simulated correlation is steeper than the observed value only 4% of the time, which suggests that the deviation is significant. The combination of protogalactic winds and dynamical friction reproduces nearly exactly the observed relationship between sigma(r) and T. C1 NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA. UNIV MICHIGAN, DEPT PHYS, ANN ARBOR, MI 48109 USA. RP BIRD, CM (reprint author), UNIV KANSAS, DEPT PHYS & ASTRON, LAWRENCE, KS 66045 USA. NR 48 TC 46 Z9 46 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 1995 VL 453 IS 1 BP 40 EP 47 DI 10.1086/176368 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TB033 UT WOS:A1995TB03300006 ER PT J AU SCHNEID, EJ BERTSCH, DL DINGUS, BL FICHTEL, CE HARTMAN, RC HUNTER, SD KANBACH, G KNIFFEN, DA LIN, YC MATTOX, JR MAYERHASSELWANDER, HA MICHELSON, PF VONMONTIGNY, C NOLAN, PL SREEKUMAR, P THOMPSON, DJ AF SCHNEID, EJ BERTSCH, DL DINGUS, BL FICHTEL, CE HARTMAN, RC HUNTER, SD KANBACH, G KNIFFEN, DA LIN, YC MATTOX, JR MAYERHASSELWANDER, HA MICHELSON, PF VONMONTIGNY, C NOLAN, PL SREEKUMAR, P THOMPSON, DJ TI EGRET MEASUREMENTS OF ENERGETIC GAMMA-RAYS FROM THE GAMMA-RAY BURSTS OF 1992 JUNE 22 AND 1994 MARCH 1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE GAMMA RAYS, BURSTS AB Energetic gamma-ray emissions from the gamma-ray bursts on 1992 June 22 (GRB 920622) and on 1994 March 1 (GRB 940301) were detected by the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO). Spectral data for both bursts were measured by EGRET's large NaI detector. Gamma rays up to 160 MeV were observed for GRB 940301 with its spark chamber telescope. Time-integrated, high-energy spectra for both bursts were fitted by single-power-law models having spectral indexes of 3.0 and 2.5 for GRB 920622 and GRB 940301, respectively. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. MAX PLANCK INST EXTRATERR PHYS,D-85748 GARCHING,GERMANY. HAMPDEN SYDNEY COLL,HAMPDEN SYDNEY,VA 23943. STANFORD UNIV,WW HANSEN EXPTL PHYS LAB,STANFORD,CA 94305. ASTRON PROGRAM,COMP SCI CORP,COMPTON OBSERV,CTR SCI SUPPORT,GREENBELT,MD 20771. ASTRON PROGRAM,COMP SCI CORP,COMPTON OBSERV,CTR SCI SUPPORT,GREENBELT,MD 20771. RP SCHNEID, EJ (reprint author), NORTHROP GRUMMAN CORP,CTR RES & DEV,MS A01-26,BETHPAGE,NY 11714, USA. RI Nolan, Patrick/A-5582-2009; Hunter, Stanley/D-2942-2012; Thompson, David/D-2939-2012; OI Thompson, David/0000-0001-5217-9135; Dingus, Brenda/0000-0001-8451-7450 NR 13 TC 29 Z9 29 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 1995 VL 453 IS 1 BP 95 EP 99 DI 10.1086/176373 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TB033 UT WOS:A1995TB03300011 ER PT J AU GUO, Z BURROWS, DN SANDERS, WT SNOWDEN, SL PENPRASE, BE AF GUO, Z BURROWS, DN SANDERS, WT SNOWDEN, SL PENPRASE, BE TI X-RAY MORPHOLOGY, KINEMATICS, AND GEOMETRY OF THE ERIDANUS SOFT-X-RAY ENHANCEMENT SO ASTROPHYSICAL JOURNAL LA English DT Article DE INFRARED, ISM, CONTINUUM; ISM, CLOUDS; X-RAYS, ISM ID ROSAT PSPC; DIFFUSE AB We present mosaics of X-ray intensity maps and spectral fit results for selected regions of the Eridanus soft X-ray enhancement (EXE), as well as kinematics of the X-ray-absorbing clouds in the EXE region and geometrical properties of this X-ray-emitting bubble. The work is based on pointed observations with the ROSAT Position Sensitive Proportional Counter, 21 cm observations with the NRAO 140 foot telescope at Green Bank and interstellar Na D line observations with the NOAO Coude Feed telescope at Kitt Peak. The ROSAT pointed observations examine two regions of the EXE. The first is an X-ray absorption lane produced by an IR filament which is located at galactic coordinates of about (200 degrees, -47 degrees). The second is in the vicinity of the northern (galactic) boundary of the 1/4 keV EXE, at galactic coordinates of about (202 degrees, -25 degrees). Both our spatial and spectral analysis suggest that variations in emission measure and N-H are primarily responsible for the observed variations of the X-ray intensity. Using 100 mu m intensities obtained from IRAS maps and N-H column densities obtained from our X-ray spectral fits, we find 100 mu m/N-H ratios across the IR filament that are compatible with typical high-latitude values. Maps of the X-ray-absorbing clouds in the EXE region at 21 cm reveal that these clouds may belong to two different expanding systems, with one possibly associated with our Local Bubble and the other with the boundary of the EXE. Based on 21 cm data and Na D observations in the direction (l, b) similar to (200 degrees, -47 degrees), our best estimate of the distance to the near side of the Orion-Eridanus bubble is 159 +/- 16 pc. We estimate the center of the bubble in this direction to be about 226 pc away, with much larger uncertainty. The density and the thermal pressure found for this X-ray-emitting superbubble are 0.015 cm(-3) and 4.9 x 10(4) cm(-3) K. C1 UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. POMONA COLL,DEPT PHYS & ASTRON,CLAREMONT,CA 91711. RP GUO, Z (reprint author), PENN STATE UNIV,DEPT ASTRON & ASTROPHYS,525 DAVEY LAB,UNIVERSITY PK,PA 16802, USA. RI Snowden, Steven/D-5292-2012 NR 33 TC 28 Z9 29 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 1995 VL 453 IS 1 BP 256 EP & DI 10.1086/176384 PN 1 PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TB033 UT WOS:A1995TB03300022 ER EF