FN Thomson Reuters Web of Science™ VR 1.0 PT S AU SKELTON, RT LING, JC RADOCINSKI, R WHEATON, WA AF SKELTON, RT LING, JC RADOCINSKI, R WHEATON, WA BE Fichtel, CE Gehrels, N Norris, JP TI STATUS OF THE BATSE ENHANCED EARTH OCCULATION ANALYSIS PACKAGE FOR STUDYING POINT SOURCES SO SECOND COMPTON SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2nd Compton Symposium CY SEP 20-22, 1993 CL UNIV MARYLAND, ADULT EDUC CTR, COLL PK, MD HO UNIV MARYLAND, ADULT EDUC CTR C1 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 1-56396-261-6 J9 AIP CONF PROC PY 1994 IS 304 BP 758 EP 760 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BA55S UT WOS:A1994BA55S00135 ER PT J AU WANG, SP MINNIS, P AF WANG, SP MINNIS, P GP AMER METEOROL SOC TI Applications of the Tiedtke's cloud scheme in a simple boundary-layer model: A comparison with satellite data SO SECOND INTERNATIONAL CONFERENCE ON AIR-SEA INTERACTION AND ON METEOROLOGY AND OCEANOGRAPHY OF THE COASTAL ZONE LA English DT Proceedings Paper CT 2nd International Conference on Air-Sea Interaction and on Meteorology and Oceanography of the Coastal Zone CY SEP 18-22, 1994 CL LISBON, PORTUGAL SP Amer Meteorol Soc, Inst Oceanog Univ Lisboa, Fundacao Fac Cien Univ Lisboa, USN, Off Naval Res, Junta Nacl Investig Cient & Tecnol, Secretaria Estado Cien & Tecnol, Fundacao Calouste Gulbenkain Mer, Camara Municipal Lisboa, Inst Francais Rech Exploitat Mer, Scient Comm Ocean Res, AMS Comm Interact Sea & Atmosphere, AMS Comm Meteorol & Oceanog Coastal Zone, AMS Comm Satellite Meteorol & Oceanog C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP 70 EP 71 PG 2 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA BD28K UT WOS:A1994BD28K00038 ER PT J AU WALSH, EJ SHAY, LK GRABER, HC GUILLAUME, A VANDEMARK, D HINES, DE SWIFT, RN SCOTT, JF AF WALSH, EJ SHAY, LK GRABER, HC GUILLAUME, A VANDEMARK, D HINES, DE SWIFT, RN SCOTT, JF GP AMER METEOROL SOC TI Wave-current interaction during SWADE .1. Observations SO SECOND INTERNATIONAL CONFERENCE ON AIR-SEA INTERACTION AND ON METEOROLOGY AND OCEANOGRAPHY OF THE COASTAL ZONE LA English DT Proceedings Paper CT 2nd International Conference on Air-Sea Interaction and on Meteorology and Oceanography of the Coastal Zone CY SEP 18-22, 1994 CL LISBON, PORTUGAL SP Amer Meteorol Soc, Inst Oceanog Univ Lisboa, Fundacao Fac Cien Univ Lisboa, USN, Off Naval Res, Junta Nacl Investig Cient & Tecnol, Secretaria Estado Cien & Tecnol, Fundacao Calouste Gulbenkain Mer, Camara Municipal Lisboa, Inst Francais Rech Exploitat Mer, Scient Comm Ocean Res, AMS Comm Interact Sea & Atmosphere, AMS Comm Meteorol & Oceanog Coastal Zone, AMS Comm Satellite Meteorol & Oceanog C1 NASA,GODDARD SPACE FLIGHT CTR,WALLOPS FLIGHT FACIL,WALLOPS ISL,VA 23337. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP 88 EP 89 PG 2 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA BD28K UT WOS:A1994BD28K00047 ER PT B AU LIU, HK AF LIU, HK BE Wang, DH Consortini, A Breckinridge, JB TI SELF-AMPLIFIED OPTICAL-PATTERN RECOGNITION SO SECOND INTERNATIONAL CONFERENCE ON OPTOELECTRONIC SCIENCE AND ENGINEERING '94 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 2nd International Conference on Optoelectronic Science and Engineering CY AUG 15-18, 1994 CL BEIJING, PEOPLES R CHINA SP CHINA ASSOC SCI & TECHNOL, INT COMMISS OPT, SOC PHOTO OPT INSTRUMENTAT ENGINEERS, JAPAN SOC APPL PHYS, D S ROZHDESTVENSKIY OPT SOC RUSSIA, CHINESE OPT SOC, PHOTON SOC CHINESE AMER, TOP COMM OPTO ELECTR TECHNOL COS CHINA, TSINGHUA UNIV CHINA, BEIJING INST TECHNOL C1 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 0-8194-1652-5 J9 P SOC PHOTO-OPT INS PY 1994 VL 2321 BP 690 EP 695 DI 10.1117/12.182101 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BB18Q UT WOS:A1994BB18Q00185 ER PT B AU HOENK, ME AF HOENK, ME BE Verly, JG Welch, SS TI SMALL INERTIAL MEASUREMENT UNITS - SOURCES OF ERROR AND LIMITATIONS ON ACCURACY SO SENSING, IMAGING, AND VISION FOR CONTROL AND GUIDANCE OF AEROSPACE VEHICLES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Sensor Systems for Control and Guidance of Aerospace Vehicles CY APR 04-05, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1524-3 J9 P SOC PHOTO-OPT INS PY 1994 VL 2220 BP 15 EP 26 DI 10.1117/12.179603 PG 12 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BB05C UT WOS:A1994BB05C00002 ER PT B AU BAUGHER, CR RAMACHANDRAN, N DELOMBARD, R AF BAUGHER, CR RAMACHANDRAN, N DELOMBARD, R BE Verly, JG Welch, SS TI AN OVERVIEW OF THE SPACE-SHUTTLE ACCELERATION ENVIRONMENT SO SENSING, IMAGING, AND VISION FOR CONTROL AND GUIDANCE OF AEROSPACE VEHICLES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Sensor Systems for Control and Guidance of Aerospace Vehicles CY APR 04-05, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. 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 0-8194-1524-3 J9 P SOC PHOTO-OPT INS PY 1994 VL 2220 BP 90 EP 101 DI 10.1117/12.179597 PG 12 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BB05C UT WOS:A1994BB05C00010 ER PT B AU SRIDHAR, B CHATTERJI, G AF SRIDHAR, B CHATTERJI, G BE Verly, JG Welch, SS TI COMPUTER-AIDED SYSTEM FOR DETECTING RUNWAY INCURSIONS SO SENSING, IMAGING, AND VISION FOR CONTROL AND GUIDANCE OF AEROSPACE VEHICLES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Sensor Systems for Control and Guidance of Aerospace Vehicles CY APR 04-05, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. 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 0-8194-1524-3 J9 P SOC PHOTO-OPT INS PY 1994 VL 2220 BP 328 EP 337 DI 10.1117/12.179617 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BB05C UT WOS:A1994BB05C00029 ER PT B AU SCHENKER, PS PETERS, SF PALJUG, ED KIM, WS AF SCHENKER, PS PETERS, SF PALJUG, ED KIM, WS BE Schenker, PS TI INTELLIGENT VIEWING CONTROL FOR ROBOTIC AND AUTOMATION SYSTEMS SO SENSOR FUSION VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Sensor Fusion VII Conference CY OCT 31-NOV 01, 1994 CL BOSTON, MA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS DE ROBOTIC SENSING; AUTOMATED MANUFACTURING WORKCELLS; VIEWING SYSTEMS; REMOTE VIEWING; TELEOPERATION; VIDEO SURVEILLANCE; AI PLANNING; 3-D GRAPHICS SIMULATION; OPERATOR DISPLAYS; GRAPHICS USER INTERFACES C1 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 0-8194-1690-8 J9 P SOC PHOTO-OPT INS PY 1994 VL 2355 BP 301 EP 313 DI 10.1117/12.189065 PG 13 WC Remote Sensing SC Remote Sensing GA BB55B UT WOS:A1994BB55B00029 ER PT J AU VANSTEENBERG, ME AF VANSTEENBERG, ME TI NASA STELLAR EXPERIMENT SO SERIALS LIBRARIAN LA English DT Article; Proceedings Paper CT 8th Annual Conference of the North-American-Serials-Interest-Group on New Scholarship: New Serials CY JUN 10-13, 1993 CL BROWN UNIV, PROVIDENCE, RI SP N AMER SERIALS INTEREST GROUP HO BROWN UNIV AB The Study of Electronic Literature for Astrophysics Research (STELAR) experiment is exploring what is required to bring the astrophysics literature online. The experiment is being conducted jointly with publishers, authors, copyright holders, libraries, and others involved in the production and dissemination of the astrophysics literature. STELAR is a pilot project designed to study the technical and practical aspects of making the refereed scientific literature available online. The primary database contains machine-readable abstractions of articles from eight journals of interest to astronomers. The current publicly accessible system contains the text of the abstracts, which are being indexed and made available using Wide Area Information Server (WAIS) and World Wide Web (WWW), providing a plain English query capability and simple document retrieval. The complete system, which includes the ability to retrieve scanned images of the pages of selected articles, is available to test subjects through selected astronomical libraries. RP VANSTEENBERG, ME (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU HAWORTH PRESS INC PI BINGHAMTON PA 10 ALICE ST, BINGHAMTON, NY 13904-1580 SN 0361-526X J9 SERIALS LIBR JI Ser. Libr. PY 1994 VL 24 IS 3-4 BP 135 EP 151 DI 10.1300/J123v24n03_17 PG 17 WC Information Science & Library Science SC Information Science & Library Science GA NG834 UT WOS:A1994NG83400017 ER PT B AU TSOU, H SHAH, B LEE, R HINEDI, S AF TSOU, H SHAH, B LEE, R HINEDI, S GP IEEE, COMMUN SOC TI A FUNCTIONAL DESCRIPTION OF THE BUFFERED TELEMETRY DEMODULATOR FOR THE GALILEO MISSION TO JUPITER SO SERVING HUMANITY THROUGH COMMUNICATIONS, VOLS 1-3: SUPERCOMM/ICC 94 LA English DT Proceedings Paper CT 1994 IEEE International Conference on Communications (SUPERCOMM/ICC 94): Serving Humanity Through Communications CY MAY 01-05, 1994 CL NEW ORLEANS, LA SP IEEE, COMMUN SOC, IEEE, NEW ORLEANS SECT, TELECOMM IND ASSOC, US TELEPHONE ASSOC C1 JET PROP LAB,PASADENA,CA 91109. 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 0-7803-1825-0 PY 1994 BP 923 EP 928 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BB15C UT WOS:A1994BB15C00173 ER PT B AU TSOU, HP SIMON, M HINEDI, S AF TSOU, HP SIMON, M HINEDI, S GP IEEE, COMMUN SOC TI CLOSED-LOOP CARRIER PHASE SYNCHRONIZATION TECHNIQUES MOTIVATED BY LIKELIHOOD FUNCTIONS SO SERVING HUMANITY THROUGH COMMUNICATIONS, VOLS 1-3: SUPERCOMM/ICC 94 LA English DT Proceedings Paper CT 1994 IEEE International Conference on Communications (SUPERCOMM/ICC 94): Serving Humanity Through Communications CY MAY 01-05, 1994 CL NEW ORLEANS, LA SP IEEE, COMMUN SOC, IEEE, NEW ORLEANS SECT, TELECOMM IND ASSOC, US TELEPHONE ASSOC C1 JET PROP LAB,PASADENA,CA 91109. 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 0-7803-1825-0 PY 1994 BP 934 EP 939 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BB15C UT WOS:A1994BB15C00175 ER PT J AU RODGERS, EB PIERCE, HF AF RODGERS, EB PIERCE, HF GP AMER METEOROL SOC TI ENVIRONMENTAL INFLUENCES ON TYPHOON-BOBBIE PRECIPITATION DISTRIBUTION SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA 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 1994 BP 14 EP 17 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00005 ER PT J AU ADLER, RF NEGRI, AJ NELKIN, EJ HUFFMAN, GJ AF ADLER, RF NEGRI, AJ NELKIN, EJ HUFFMAN, GJ GP AMER METEOROL SOC TI MICROWAVE AND INFRARED RAIN ESTIMATES DURING TOGA-COARE SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA 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 1994 BP 26 EP 29 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00008 ER PT J AU SHENK, WE HOPE, WA AF SHENK, WE HOPE, WA GP AMER METEOROL SOC TI COMPARISON STUDY OF VISIBLE STEREO VS INFRARED STEREO PHASE .2. SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA SP AMER METEOROL SOC C1 NASA,GODDARD SPACE FLIGHT CTR,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 1994 BP 63 EP 66 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00018 ER PT J AU SALANTHE, EP CHESTERS, D SUD, YC AF SALANTHE, EP CHESTERS, D SUD, YC GP AMER METEOROL SOC TI EVALUATION OF GLA-GCM UPPER-TROPOSPHERIC MOISTURE USING TOVS RADIANCE OBSERVATIONS SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA SP AMER METEOROL SOC C1 NASA,GODDARD SPACE FLIGHT CTR,GODDARD LAB ATMOSPHERES,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 1994 BP 99 EP 102 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00028 ER PT J AU JEDLOVEC, GJ CARLSON, GS AF JEDLOVEC, GJ CARLSON, GS GP AMER METEOROL SOC TI GUESS DEPENDENCE OF THE PHYSICAL SPLIT WINDOW TECHNIQUE FOR THE RETRIEVAL OF INTEGRATED WATER CONTENT SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA SP AMER METEOROL SOC C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,OBSERVING SYST BRANCH,HUNTSVILLE,AL 35812. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP 118 EP 121 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00034 ER PT J AU NEGRI, AJ ADLER, RF NELKIN, EJ HUFFMAN, GJ MASSAMBANI, O AF NEGRI, AJ ADLER, RF NELKIN, EJ HUFFMAN, GJ MASSAMBANI, O GP AMER METEOROL SOC TI DIURNAL AND INTERANNUAL VARIABILITY OF PRECIPITATION OVER AMAZONIA DERIVED FROM SSM/I DATA SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA 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 1994 BP 136 EP 139 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00039 ER PT J AU HOOD, RE SPENCER, RW LAFONTAINE, FJ SMITH, EA AF HOOD, RE SPENCER, RW LAFONTAINE, FJ SMITH, EA GP AMER METEOROL SOC TI SIMULATION OF FUTURE PASSIVE MICROWAVE SATELLITE INSTRUMENTS USING HIGH RESOLUTION AMPR AIRCRAFT DATA SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA SP AMER METEOROL SOC C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP 160 EP 163 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00045 ER PT J AU HUFFMAN, GJ ADLER, RF KEEHN, PR AF HUFFMAN, GJ ADLER, RF KEEHN, PR GP AMER METEOROL SOC TI EXPERIMENTS WITH A TECHNIQUE FOR COMBINING SATELLITE-BASED PRECIPITATION ESTIMATES WITH GAUGE AND MODEL ESTIMATES SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA 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 1994 BP 197 EP 200 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00055 ER PT J AU SHAN, KP RIND, D AF SHAN, KP RIND, D GP AMER METEOROL SOC TI THE NEW VERSUS THE FAMILIAR - MSU BRIGHTNESSES AND THE OORT RADIOSONDE CLIMATOLOGY SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA SP AMER METEOROL SOC C1 COLUMBIA UNIV,COLUMBIA GLOBAL SYST INST,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP 266 EP 269 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00071 ER PT B AU HARRISON, EF YOUNG, DF MINNIS, P WIELICKI, BA DOELLING, DR GIBSON, GG AF HARRISON, EF YOUNG, DF MINNIS, P WIELICKI, BA DOELLING, DR GIBSON, GG GP AMER METEOROL SOC TI TEMPORAL SAMPLING ANALYSIS FOR THE CLOUDS AND THE EARTHS RADIANT ENERGY SYSTEM (CERES) EXPERIMENT FOR SATELLITE MISSIONS IN THE LATE 1990S SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA SP AMER METEOROL SOC C1 NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,HAMPTON,VA 23665. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP 520 EP 523 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00139 ER PT J AU CHOU, SH ATLAS, RM SHIE, CL ARDIZZONE, J AF CHOU, SH ATLAS, RM SHIE, CL ARDIZZONE, J GP AMER METEOROL SOC TI A WESTERLY WIND BURST AND ITS IMPACT ON LATENT HEAT FLUX OBSERVED FROM SPECIAL SENSOR MICROWAVE IMAGER SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA 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 1994 BP 596 EP 599 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00161 ER PT B AU HAJJ, GA KURSINSKI, ER BERTIGER, WI ROMANS, LJ HARDY, KR AF HAJJ, GA KURSINSKI, ER BERTIGER, WI ROMANS, LJ HARDY, KR GP AMER METEOROL SOC TI ASSESSMENT OF GPS OCCULTATIONS FOR ATMOSPHERIC PROFILING SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA SP AMER METEOROL SOC C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 5 Z9 5 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP J7 EP J10 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00169 ER PT J AU JEDLOVEC, GJ GUILLORY, AR CARLSON, GS AF JEDLOVEC, GJ GUILLORY, AR CARLSON, GS GP AMER METEOROL SOC TI THE RETRIEVAL OF INTEGRATED WATER CONTENT FROM GOES .1. SO SEVENTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 7th Conference on Satellite Meteorology and Oceanography/9th Conference on Middle Atmosphere CY JUN 06-10, 1994 CL MONTEREY, CA SP AMER METEOROL SOC C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,OBSERVING SYST BRANCH,HUNTSVILLE,AL 35812. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP J3 EP J6 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BC37T UT WOS:A1994BC37T00168 ER PT B AU HARRIS, AW AF HARRIS, AW BE Kozai, Y Binzel, RP Hirayama, T TI CCD systems for searching for near-earth asteroids SO SEVENTY-FIVE YEARS OF HIRAYAMA ASTEROID FAMILIES: THE ROLE OF COLLISIONS IN THE SOLAR SYSTEM HISTORY SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT International Conference on 75-Years of Hirayama Asteroid Families - The Role of Collisions in the Solar System History CY NOV 29-DEC 03, 1993 CL INST SPACE & ASTRONAUT SCI, SAGAMIHARA, JAPAN HO INST SPACE & ASTRONAUT SCI C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 0 TC 5 Z9 5 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 BN 0-937707-82-1 J9 ASTR SOC P PY 1994 VL 63 BP 203 EP 213 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BD73X UT WOS:A1994BD73X00027 ER PT J AU FEIVESON, AH AF FEIVESON, AH TI FINDING THE BEST REGRESSION SUBSET BY REDUCTION IN NONFULL-RANK CASES SO SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS LA English DT Article DE REGRESSION; SUBSET SELECTION; RIDGE REGRESSION ID BIASED-ESTIMATION; SELECTION; VARIABLES AB The computational problem of finding the best fitting subset of independent variables in least-squares regression with a fixed subset size is addressed, especially in the context of the nonfull-rank case with more variables than observations. For the full-rank case, the most efficient widely used methods work by finding the complementary subset with minimum reduction to the total regression sum of squares; a task that can usually be accomplished with far less computation than exhaustive evaluation of all subsets. Here, a method using Cholesky-type factorizations (Algorithm 2) has been developed, which also takes advantage of the computational savings offered by the ''reduction'' approach, but which can be used in nonfull-rank cases where existing methods are not applicable. Algorithm 2 is derived by examining the asymptotic properties of a full-rank procedure (Algorithm 1) used on a ''ridge'' perturbation of the cross-product matrix. In the course of testing, it was discovered that Algorithm I, with the appropriate ridge parameter, usually selected the best subset with less computation than Algorithm 2; however, if one requires mathematical certitude, use of Algorithm 2 is indicated. Also, some new approaches are proposed for developing efficient methods of identifying the best subset directly, rather than by complement to the minimum-reduction subset. RP FEIVESON, AH (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 0895-4798 J9 SIAM J MATRIX ANAL A JI SIAM J. Matrix Anal. Appl. PD JAN PY 1994 VL 15 IS 1 BP 194 EP 204 DI 10.1137/S0895479891221721 PG 11 WC Mathematics, Applied SC Mathematics GA MV296 UT WOS:A1994MV29600016 ER PT J AU GRIMES, RG LEWIS, JG SIMON, HD AF GRIMES, RG LEWIS, JG SIMON, HD TI A SHIFTED BLOCK LANCZOS-ALGORITHM FOR SOLVING SPARSE SYMMETRICAL GENERALIZED EIGENPROBLEMS SO SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS LA English DT Article DE LANCZOS ALGORITHM; SPARSE EIGENVALUE PROBLEMS; STRUCTURAL ANALYSIS; SYMMETRICAL GENERALIZED EIGENVALUE PROBLEM; ORTHOGONALIZATION METHODS ID MATRIX; REORTHOGONALIZATION AB An ''industrial strength'' algorithm for solving sparse symmetric generalized eigenproblems is described. The algorithm has its foundations in known techniques in solving sparse symmetric eigenproblems, notably the spectral transformation of Ericsson and Ruhe and the block Lanczos algorithm. However, the combination of these two techniques is not trivial; there are many pitfalls awaiting the unwary implementor. The focus of this paper is on identifying those pitfalls and avoiding them, leading to a ''bomb-proof'' algorithm that can live as a black box eigensolver inside a large applications code. The code that results comprises a robust shift selection strategy and a block Lanczos algorithm that is a novel combination of new techniques and extensions of old techniques. C1 NASA,AMES RES CTR,DIV NUMER AERODYNAM SIMULAT SYST,MOFFETT FIELD,CA 94035. RP GRIMES, RG (reprint author), BOEING COMP SERV CO,DIV RES & TECHNOL,MATH & ENGN ANAL,MAIL STOP 7L-22,POB 24346,SEATTLE,WA 98124, USA. NR 40 TC 205 Z9 213 U1 0 U2 6 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 0895-4798 J9 SIAM J MATRIX ANAL A JI SIAM J. Matrix Anal. Appl. PD JAN PY 1994 VL 15 IS 1 BP 228 EP 272 DI 10.1137/S0895479888151111 PG 45 WC Mathematics, Applied SC Mathematics GA MV296 UT WOS:A1994MV29600020 ER PT B AU CHAKRAVARTHI, PR WEINER, DD AF CHAKRAVARTHI, PR WEINER, DD BE Drummond, OE TI LOW SIGNAL-TO-CLUTTER RATIO PROCESSING OF RADAR SIGNALS SO SIGNAL AND DATA PROCESSING OF SMALL TARGETS 1994 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Signal and Data Processing of Small Targets 1994 CY APR 05-07, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 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 0-8194-1539-1 J9 P SOC PHOTO-OPT INS PY 1994 VL 2235 BP 62 EP 70 DI 10.1117/12.179101 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BA84C UT WOS:A1994BA84C00006 ER PT S AU FATHAUER, RW GEORGE, T JONES, EW PIKE, WT SHORT, KT VASQUEZ, RP WHITE, AE WILKENS, BJ AF FATHAUER, RW GEORGE, T JONES, EW PIKE, WT SHORT, KT VASQUEZ, RP WHITE, AE WILKENS, BJ BE Fathauer, RW Mantl, S Schowalter, LJ Tu, KN TI APPLICATION OF NOVEL EPITAXY TECHNIQUES TO THE GROWTH OF CRSI2 SO SILICIDES, GERMANIDES, AND THEIR INTERFACES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Silicides, Germanides, and Their Interfaces, at the 1993 Fall Meeting of the Materials Research Society CY NOV 29-DEC 02, 1993 CL BOSTON, MA SP MAT RES SOC C1 JET PROP LAB,PASADENA,CA 91109. 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 1-55899-219-7 J9 MATER RES SOC SYMP P PY 1994 VL 320 BP 453 EP 458 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BA82H UT WOS:A1994BA82H00065 ER PT J AU CHAO, WC AF CHAO, WC GP AMER METEOROL SOC TI A critique of wave-CISK as an explanation for the 40-50 day tropical intraseasonal oscillations SO SIXTH CONFERENCE ON MESOSCALE PROCESSES LA English DT Proceedings Paper CT 6th Conference on Mesoscale Processes CY JUL 18-22, 1994 CL PORTLAND, OR SP Amer Meteor 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 1994 BP 83 EP 84 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BE02R UT WOS:A1994BE02R00023 ER PT J AU TOKAY, A SHORT, DA AF TOKAY, A SHORT, DA GP AMER METEOROL SOC TI Case studies of convective vs stratiform rain over Kapingamarangi Atoll during TOGA COARE SO SIXTH CONFERENCE ON MESOSCALE PROCESSES LA English DT Proceedings Paper CT 6th Conference on Mesoscale Processes CY JUL 18-22, 1994 CL PORTLAND, OR SP Amer Meteor Soc C1 NASA,GODDARD SPACE FLIGHT CTR,TRMM OFF,GREENBELT,MD 20771. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP 85 EP 88 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BE02R UT WOS:A1994BE02R00024 ER PT J AU GUILLORY, AR JEDLOVEC, GJ AF GUILLORY, AR JEDLOVEC, GJ GP AMER METEOROL SOC TI A mesoscale moisture analysis of a Florida sea breeze from CaPE SO SIXTH CONFERENCE ON MESOSCALE PROCESSES LA English DT Proceedings Paper CT 6th Conference on Mesoscale Processes CY JUL 18-22, 1994 CL PORTLAND, OR SP Amer Meteor Soc C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,OBSERVING SYST BRANCH,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1994 BP 238 EP 241 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BE02R UT WOS:A1994BE02R00073 ER PT J AU CHEN, C AF CHEN, C GP AMER METEOROL SOC TI Numerical simulations of gravity currents in uniform shear flows SO SIXTH CONFERENCE ON MESOSCALE PROCESSES LA English DT Proceedings Paper CT 6th Conference on Mesoscale Processes CY JUL 18-22, 1994 CL PORTLAND, OR SP Amer Meteor Soc C1 NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,MESOSCALE DYNAM & PRECIPITAT BRANCH,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 1994 BP 250 EP 253 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BE02R UT WOS:A1994BE02R00076 ER PT B AU FAUR, M FAUR, M FLOOD, DJ GORADIA, M WILT, DM AF FAUR, M FAUR, M FLOOD, DJ GORADIA, M WILT, DM GP IEEE TI ELECTROLYTE FOR EC-V PROFILING OF INP AND GAAS BASED HETEROSTRUCTURES SO SIXTH INTERNATIONAL CONFERENCE ON INDIUM PHOSPHIDE AND RELATED MATERIALS: CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 6th International Conference on Indium Phosphide and Related Materials CY MAR 27-31, 1994 CL SANTA BARBARA, CA SP IEEE, LASERS & ELECTR OPT SOC, IEEE, ELECTRON DEVICES SOC, NATL SCI FDN, ADV RES PROJ AGCY, ROME LAB C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 1 Z9 1 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-1476-X PY 1994 BP 508 EP 511 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Optics SC Engineering; Materials Science; Optics GA BA48A UT WOS:A1994BA48A00129 ER PT S AU SINGH, JJ EFTEKHARI, A STCLAIR, TL AF SINGH, JJ EFTEKHARI, A STCLAIR, TL BE Ottewitte, E Weiss, AH TI A LOW-ENERGY POSITRON FLUX GENERATOR FOR MICROSTRUCTURAL CHARACTERIZATION OF THIN POLYMER-FILMS SO SLOW POSITRON BEAM TECHNIQUES FOR SOLIDS AND SURFACES: FIFTH INTERNATIONAL WORKSHOP SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 5th International Workshop on Slow Positron Beam Techniques for Solids and Surfaces CY AUG, 1992 CL JACKSON HOLE, WY C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. 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 1-56396-267-5 J9 AIP CONF PROC PY 1994 IS 303 BP 516 EP 525 PG 10 WC Physics, Applied; Physics, Condensed Matter SC Physics GA BA55R UT WOS:A1994BA55R00057 ER PT B AU HENKEL, DP AF HENKEL, DP BE Varadan, VK TI MICROSTRUCTURAL EFFECTS OF EMBEDDING OPTICAL FIBERS IN POLYMER-MATRIX COMPOSITES SO SMART MATERIALS: SMART STRUCTURES AND MATERIALS 1994 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Materials: Smart Structures and Materials 1994 CY FEB 14-16, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS, SOC EXPTL MECH C1 NASA,LANGLEY RES CTR,ANALYT SERV & MAT INC,HAMPTON,VA 23681. 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 0-8194-1484-0 J9 P SOC PHOTO-OPT INS PY 1994 VL 2189 BP 378 EP 386 DI 10.1117/12.174073 PG 9 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BA45S UT WOS:A1994BA45S00035 ER PT S AU MADEJSKI, G DONE, C TURNER, TJ MUSHOTZKY, RF SERLEMITSOS, P FIORE, F SIKORA, M BEGELMAN, M AF MADEJSKI, G DONE, C TURNER, TJ MUSHOTZKY, RF SERLEMITSOS, P FIORE, F SIKORA, M BEGELMAN, M BE Schlegel, EM Petre, R TI SOLVING THE MYSTERY OF THE PERIODICITY IN THE SEYFERT-GALAXY NGC-6814 SO SOFT X-RAY COSMOS: ROSAT SCIENCE SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ROSAT Science Symposium/Data Analysis Workshop CY NOV 08-10, 1993 CL COLLEGE PK, MD SP AMER INST PHYS C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RI done, chris/D-4605-2016 OI done, chris/0000-0002-1065-7239 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 1-56396-327-2 J9 AIP CONF PROC PY 1994 IS 313 BP 59 EP 63 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB56K UT WOS:A1994BB56K00008 ER PT S AU REICHERT, GA MUSHOTZKY, RF FILIPPENKO, AV AF REICHERT, GA MUSHOTZKY, RF FILIPPENKO, AV BE Schlegel, EM Petre, R TI ROSAT OBSERVATIONS OF LINERS SO SOFT X-RAY COSMOS: ROSAT SCIENCE SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ROSAT Science Symposium/Data Analysis Workshop CY NOV 08-10, 1993 CL COLLEGE PK, MD SP AMER INST PHYS C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 3 Z9 3 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 1-56396-327-2 J9 AIP CONF PROC PY 1994 IS 313 BP 85 EP 94 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB56K UT WOS:A1994BB56K00012 ER PT S AU CORCORAN, MF SWANK, J RAWLEY, G PETRE, R SCHMITT, J DAY, C AF CORCORAN, MF SWANK, J RAWLEY, G PETRE, R SCHMITT, J DAY, C BE Schlegel, EM Petre, R TI THE CARINA NEBULA IN X-RAYS SO SOFT X-RAY COSMOS: ROSAT SCIENCE SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ROSAT Science Symposium/Data Analysis Workshop CY NOV 08-10, 1993 CL COLLEGE PK, MD SP AMER INST PHYS C1 NASA,GODDARD SPACE FLIGHT CTR,USRA,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 1-56396-327-2 J9 AIP CONF PROC PY 1994 IS 313 BP 159 EP 163 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB56K UT WOS:A1994BB56K00022 ER PT S AU SCHLEGEL, EM AF SCHLEGEL, EM BE Schlegel, EM Petre, R TI ROSAT OBSERVATIONS OF SUPERNOVAE SO SOFT X-RAY COSMOS: ROSAT SCIENCE SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ROSAT Science Symposium/Data Analysis Workshop CY NOV 08-10, 1993 CL COLLEGE PK, MD SP AMER INST PHYS C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 2 Z9 2 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 1-56396-327-2 J9 AIP CONF PROC PY 1994 IS 313 BP 195 EP 204 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB56K UT WOS:A1994BB56K00027 ER PT S AU LEITER, D BOLDT, E AF LEITER, D BOLDT, E BE Schlegel, EM Petre, R TI CAN AGN ALONE MAKE THE COSMIC X-RAY-BACKGROUND SO SOFT X-RAY COSMOS: ROSAT SCIENCE SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ROSAT Science Symposium/Data Analysis Workshop CY NOV 08-10, 1993 CL COLLEGE PK, MD SP AMER INST PHYS C1 NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS 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 1-56396-327-2 J9 AIP CONF PROC PY 1994 IS 313 BP 216 EP 220 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB56K UT WOS:A1994BB56K00030 ER PT S AU DRAKE, SA WHITE, NE SMALE, AP ANGELINI, L MARSHALL, FE PRAVDO, SH AF DRAKE, SA WHITE, NE SMALE, AP ANGELINI, L MARSHALL, FE PRAVDO, SH BE Schlegel, EM Petre, R TI AN X-RAY SPECTRAL STUDY OF ALGOL BINARY-SYSTEMS SO SOFT X-RAY COSMOS: ROSAT SCIENCE SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ROSAT Science Symposium/Data Analysis Workshop CY NOV 08-10, 1993 CL COLLEGE PK, MD SP AMER INST PHYS C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-327-2 J9 AIP CONF PROC PY 1994 IS 313 BP 272 EP 274 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB56K UT WOS:A1994BB56K00042 ER PT S AU RHO, JH PETRE, R HESTER, JJ AF RHO, JH PETRE, R HESTER, JJ BE Schlegel, EM Petre, R TI ROSAT OBSERVATIONS OF IC-443 SO SOFT X-RAY COSMOS: ROSAT SCIENCE SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ROSAT Science Symposium/Data Analysis Workshop CY NOV 08-10, 1993 CL COLLEGE PK, MD SP AMER INST PHYS 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 1-56396-327-2 J9 AIP CONF PROC PY 1994 IS 313 BP 318 EP & PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB56K UT WOS:A1994BB56K00054 ER PT S AU SCHLEGEL, EM AF SCHLEGEL, EM BE Schlegel, EM Petre, R TI A ROSAT OBSERVATION OF THE SPIRAL GALAXY NGC-6946 SO SOFT X-RAY COSMOS: ROSAT SCIENCE SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ROSAT Science Symposium/Data Analysis Workshop CY NOV 08-10, 1993 CL COLLEGE PK, MD SP AMER INST PHYS 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 1-56396-327-2 J9 AIP CONF PROC PY 1994 IS 313 BP 336 EP 338 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB56K UT WOS:A1994BB56K00060 ER PT S AU LOEWENSTEIN, M PETRE, R AF LOEWENSTEIN, M PETRE, R BE Schlegel, EM Petre, R TI PSPC OBSERVATIONS OF THE NGC-3607 GROUP OF GALAXIES SO SOFT X-RAY COSMOS: ROSAT SCIENCE SYMPOSIUM SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ROSAT Science Symposium/Data Analysis Workshop CY NOV 08-10, 1993 CL COLLEGE PK, MD SP AMER INST PHYS 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 1-56396-327-2 J9 AIP CONF PROC PY 1994 IS 313 BP 355 EP 357 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB56K UT WOS:A1994BB56K00066 ER PT B AU MERTZ, CW AF MERTZ, CW GP SWISS ASSOC PROMOT QUAL TI Using independent verification and validation (IV and V) to maximize the return in software development SO SOFTWARE QUALITY - CONCERN FOR PEOPLE LA English DT Proceedings Paper CT 4th European Conference on Software Quality CY OCT 17-20, 1994 CL BASEL, SWITZERLAND SP Swiss Assoc Promot Qual, European Org Qual, Software Comm C1 NASA,SOFTWARE IV&V FACIL,FAIRMONT,WV 26554. NR 0 TC 0 Z9 0 U1 0 U2 0 PU VERLAG FACHVEREINE ETH ZURICH PI ZURICH PA VOLTASTR 24, 8044 ZURICH, SWITZERLAND BN 3-7281-2153-3 PY 1994 BP 22 EP 29 PG 2 WC Computer Science, Software Engineering; Ergonomics; Psychology SC Computer Science; Engineering; Psychology GA BD65J UT WOS:A1994BD65J00002 ER PT S AU CAPO, RC AF CAPO, RC BE RingroseVoase, AJ Humphreys, GS TI MICROMORPHOLOGY OF A CAMBRIAN PALEOSOL DEVELOPED ON GRANITE - LLANO UPLIFT REGION, CENTRAL TEXAS, USA SO SOIL MICROMORPHOLOGY: STUDIES IN MANAGEMENT AND GENESIS SE DEVELOPMENTS IN SOIL SCIENCE LA English DT Proceedings Paper CT IX International Working Meeting on Soil Micromorphology - Studies in Management and Genesis CY JUL, 1992 CL TOWNSVILLE, AUSTRALIA SP INT SOC SOIL SCI, SUBCOMM SOIL MICROMORPHOL, AUSTR SOC SOIL SCI, CSIRO, DIV SOILS, AUSTR INT DEV ASISTANCE BUR, QANTAS AIRWAYS LTD, WESTPAC BANKING CORP C1 CALTECH,JET PROP LAB,PASADENA,CA 91125. NR 0 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE PUBL B V PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-0918 BN 0-444-89792-5 J9 DEV SOIL SCI PY 1994 VL 22 BP 257 EP 264 PG 8 WC Geosciences, Multidisciplinary; Soil Science SC Geology; Agriculture GA BC77X UT WOS:A1994BC77X00022 ER PT S AU CHADWICK, OA NETTLETON, WD AF CHADWICK, OA NETTLETON, WD BE RingroseVoase, AJ Humphreys, GS TI QUANTITATIVE RELATIONSHIPS BETWEEN NET VOLUME CHANGE AND FABRIC PROPERTIES DURING SOIL EVOLUTION SO SOIL MICROMORPHOLOGY: STUDIES IN MANAGEMENT AND GENESIS SE DEVELOPMENTS IN SOIL SCIENCE LA English DT Proceedings Paper CT IX International Working Meeting on Soil Micromorphology - Studies in Management and Genesis CY JUL, 1992 CL TOWNSVILLE, AUSTRALIA SP INT SOC SOIL SCI, SUBCOMM SOIL MICROMORPHOL, AUSTR SOC SOIL SCI, CSIRO, DIV SOILS, AUSTR INT DEV ASISTANCE BUR, QANTAS AIRWAYS LTD, WESTPAC BANKING CORP C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE PUBL B V PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-0918 BN 0-444-89792-5 J9 DEV SOIL SCI PY 1994 VL 22 BP 353 EP 359 PG 7 WC Geosciences, Multidisciplinary; Soil Science SC Geology; Agriculture GA BC77X UT WOS:A1994BC77X00032 ER PT B AU GARY, GA DEMOULIN, P AF GARY, GA DEMOULIN, P BE Balasubramaniam, KS Simon, GW TI Electric current systems in solar active regions SO SOLAR ACTIVE REGION EVOLUTION: COMPARING MODELS WITH OBSERVATIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 14th NSO/SP International Summer Workshop on Solar Active Region Evolution - Comparing Models with Observations CY AUG 30-SEP 03, 1993 CL NATL SOLAR OBSERV, SACRAMENTO PEAK SUNSPOT, NM SP Natl Solar Observ, Natl Opt Astron Observ, Div Atmospher Sci, Natl Sci Fdn, Space Sci Div, NASA, AFOSR, European Off Aerosp Res & Dev, AFOSR, Asian Off Sci Res & Dev HO NATL SOLAR OBSERV C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 BN 0-937707-87-2 J9 ASTR SOC P PY 1994 VL 68 BP 171 EP 179 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BD49H UT WOS:A1994BD49H00022 ER PT B AU JONES, HP AF JONES, HP BE Balasubramaniam, KS Simon, GW TI Flow patterns in active regions SO SOLAR ACTIVE REGION EVOLUTION: COMPARING MODELS WITH OBSERVATIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 14th NSO/SP International Summer Workshop on Solar Active Region Evolution - Comparing Models with Observations CY AUG 30-SEP 03, 1993 CL NATL SOLAR OBSERV, SACRAMENTO PEAK SUNSPOT, NM SP Natl Solar Observ, Natl Opt Astron Observ, Div Atmospher Sci, Natl Sci Fdn, Space Sci Div, NASA, AFOSR, European Off Aerosp Res & Dev, AFOSR, Asian Off Sci Res & Dev HO NATL SOLAR OBSERV C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & ASTROPHYS LAB,SW SOLAR STN,TUCSON,AZ 85726. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 BN 0-937707-87-2 J9 ASTR SOC P PY 1994 VL 68 BP 286 EP 293 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BD49H UT WOS:A1994BD49H00036 ER PT B AU HOLMAN, GD AF HOLMAN, GD BE Balasubramaniam, KS Simon, GW TI Coronal structures in active regions: Quantitative results from multi-wavelength observations and comparisons with models SO SOLAR ACTIVE REGION EVOLUTION: COMPARING MODELS WITH OBSERVATIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 14th NSO/SP International Summer Workshop on Solar Active Region Evolution - Comparing Models with Observations CY AUG 30-SEP 03, 1993 CL NATL SOLAR OBSERV, SACRAMENTO PEAK SUNSPOT, NM SP Natl Solar Observ, Natl Opt Astron Observ, Div Atmospher Sci, Natl Sci Fdn, Space Sci Div, NASA, AFOSR, European Off Aerosp Res & Dev, AFOSR, Asian Off Sci Res & Dev HO NATL SOLAR OBSERV C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RI Holman, Gordon/C-9548-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 BN 0-937707-87-2 J9 ASTR SOC P PY 1994 VL 68 BP 356 EP 368 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BD49H UT WOS:A1994BD49H00044 ER PT B AU JORDAN, SD AF JORDAN, SD BE Rusin, V Heinzel, P Vial, JC TI LINE FORMATION AND INTENSITY ENHANCEMENT OF THE HE-II 304 angstrom LINE IN THE SOLAR ATMOSPHERE SO SOLAR CORONAL STRUCTURES LA English DT Proceedings Paper CT 144th Colloquium of the International-Astronomical-Union on Solar Coronal Structures, on the Occasion of the 50th Anniversary of the Skalnate-Pleso-Observatory CY SEP 20-24, 1993 CL TATRANSKA LOMNICA, SLOVAKIA SP AIR TRANSPORT EUROPE, POPRAD, SLOVAKIA, AKAD VZDELAVANIA, POPRAD, SLOVAKIA, ART AGCY IPP, POPRAD, SLOVAKIA, ASTRON INST, TATRANSKA LOMNICA, SLOVAKIA, ASTRON INST, ONDREJOV, CZECH REPUBLIC, COMENIUS UNIV, DEPT ASTRON & ASTROPHYS, BRATISLAVA, SLOVAKIA, EUROPEAN SPACE AGCY, EDEN CLUB, STARA LESNA, SLOVAKIA, INT ASTRON UNION, LOCAL MUNICIPAL, STARY SMOKOVEC, SLOVAKIA, OBSERV & PLANETARIUM, PRESOV, SLOVAKIA, OTF A S, NIZNA, SLOVAKIA, PARSEK, SR O, PRAGUE, CZECH REPUBLIC, SLOVAK ASTRON SOC, SLOVAK CTR AMATEUR ASTRON, HURBANOVO, SLOVAKIA, SLOVENSKA STATNA SPORITELNA, POPRAD, SLOVAKIA, T A N A P, TATRANSKA LOMNICA, SLOVAKIA, TAKAJ, SLOVENSKE NOVE MESTO, SLOVAKIA, WHIRLPOOL TATRAMAT CO, POPRAD MATEJOVCE, SLOVAKIA DE HELIUM EMISSION; TRANSITION REGION; LINE FORMATION C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU VEDA PI BRATISLAVA PA SLOVAK ACAD SCIENCES KLEMENSOVA 19, BRATISLAVA, 81430, SLOVAK REPUBLIC BN 80-224-0090-4 PY 1994 BP 415 EP 420 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BC99K UT WOS:A1994BC99K00078 ER PT B AU GUHATHAKURTA, M AF GUHATHAKURTA, M BE Rusin, V Heinzel, P Vial, JC TI QUANTITATIVE DESCRIPTION OF THE PB AN ELECTRON DENSITY DISTRIBUTIONS AROUND THE INFERRED NEUTRAL LINE SO SOLAR CORONAL STRUCTURES LA English DT Proceedings Paper CT 144th Colloquium of the International-Astronomical-Union on Solar Coronal Structures, on the Occasion of the 50th Anniversary of the Skalnate-Pleso-Observatory CY SEP 20-24, 1993 CL TATRANSKA LOMNICA, SLOVAKIA SP AIR TRANSPORT EUROPE, POPRAD, SLOVAKIA, AKAD VZDELAVANIA, POPRAD, SLOVAKIA, ART AGCY IPP, POPRAD, SLOVAKIA, ASTRON INST, TATRANSKA LOMNICA, SLOVAKIA, ASTRON INST, ONDREJOV, CZECH REPUBLIC, COMENIUS UNIV, DEPT ASTRON & ASTROPHYS, BRATISLAVA, SLOVAKIA, EUROPEAN SPACE AGCY, EDEN CLUB, STARA LESNA, SLOVAKIA, INT ASTRON UNION, LOCAL MUNICIPAL, STARY SMOKOVEC, SLOVAKIA, OBSERV & PLANETARIUM, PRESOV, SLOVAKIA, OTF A S, NIZNA, SLOVAKIA, PARSEK, SR O, PRAGUE, CZECH REPUBLIC, SLOVAK ASTRON SOC, SLOVAK CTR AMATEUR ASTRON, HURBANOVO, SLOVAKIA, SLOVENSKA STATNA SPORITELNA, POPRAD, SLOVAKIA, T A N A P, TATRANSKA LOMNICA, SLOVAKIA, TAKAJ, SLOVENSKE NOVE MESTO, SLOVAKIA, WHIRLPOOL TATRAMAT CO, POPRAD MATEJOVCE, SLOVAKIA C1 USRA,GSFC,GREENBELT,MD 20771. NR 0 TC 1 Z9 1 U1 0 U2 0 PU VEDA PI BRATISLAVA PA SLOVAK ACAD SCIENCES KLEMENSOVA 19, BRATISLAVA, 81430, SLOVAK REPUBLIC BN 80-224-0090-4 PY 1994 BP 427 EP 430 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BC99K UT WOS:A1994BC99K00080 ER PT B AU OFMAN, L DAVILA, JM STEINOLFSON, RS AF OFMAN, L DAVILA, JM STEINOLFSON, RS BE Rusin, V Heinzel, P Vial, JC TI CORONAL HEATING BY THE RESONANT ABSORPTION OF ALFVEN WAVES SO SOLAR CORONAL STRUCTURES LA English DT Proceedings Paper CT 144th Colloquium of the International-Astronomical-Union on Solar Coronal Structures, on the Occasion of the 50th Anniversary of the Skalnate-Pleso-Observatory CY SEP 20-24, 1993 CL TATRANSKA LOMNICA, SLOVAKIA SP AIR TRANSPORT EUROPE, POPRAD, SLOVAKIA, AKAD VZDELAVANIA, POPRAD, SLOVAKIA, ART AGCY IPP, POPRAD, SLOVAKIA, ASTRON INST, TATRANSKA LOMNICA, SLOVAKIA, ASTRON INST, ONDREJOV, CZECH REPUBLIC, COMENIUS UNIV, DEPT ASTRON & ASTROPHYS, BRATISLAVA, SLOVAKIA, EUROPEAN SPACE AGCY, EDEN CLUB, STARA LESNA, SLOVAKIA, INT ASTRON UNION, LOCAL MUNICIPAL, STARY SMOKOVEC, SLOVAKIA, OBSERV & PLANETARIUM, PRESOV, SLOVAKIA, OTF A S, NIZNA, SLOVAKIA, PARSEK, SR O, PRAGUE, CZECH REPUBLIC, SLOVAK ASTRON SOC, SLOVAK CTR AMATEUR ASTRON, HURBANOVO, SLOVAKIA, SLOVENSKA STATNA SPORITELNA, POPRAD, SLOVAKIA, T A N A P, TATRANSKA LOMNICA, SLOVAKIA, TAKAJ, SLOVENSKE NOVE MESTO, SLOVAKIA, WHIRLPOOL TATRAMAT CO, POPRAD MATEJOVCE, SLOVAKIA DE SUN; MHD C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. NR 0 TC 0 Z9 0 U1 0 U2 0 PU VEDA PI BRATISLAVA PA SLOVAK ACAD SCIENCES KLEMENSOVA 19, BRATISLAVA, 81430, SLOVAK REPUBLIC BN 80-224-0090-4 PY 1994 BP 473 EP 477 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BC99K UT WOS:A1994BC99K00088 ER PT B AU KYLE, HL HOYT, DV HICKEY, JR AF KYLE, HL HOYT, DV HICKEY, JR BE Baker, DN Papitashvili, VO Teague, MJ TI THE NIMBUS-7 TOTAL SOLAR IRRADIANCE MEASUREMENTS NOVEMBER 1978 TO MAY 1992 SO SOLAR-TERRESTRIAL ENERGY PROGRAM: INITIAL RESULTS FROM STEP FACILITIES AND THEORY CAMPAIGNS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 1992 STEP Symposium/5th COSPAR Colloquium CY AUG 24-28, 1992 CL JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD SP SCI COMM SOLAR TERRESTRIAL PHYS, NASA, NATL SCI FDN, NATL OCEAN & ATMOSPHER ADM, AIR FORCE GEOPHYS LAB HO JOHNS HOPKINS UNIV, APPL PHYS LAB C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042131-8 J9 COSPAR COLL PY 1994 VL 5 BP 69 EP 72 PG 4 WC Astronomy & Astrophysics; Energy & Fuels SC Astronomy & Astrophysics; Energy & Fuels GA BB79N UT WOS:A1994BB79N00009 ER PT B AU TOBISKA, WK SCHMIDTKE, G DOLL, H WOODS, TN WORDEN, J CHAKRABARTI, S AF TOBISKA, WK SCHMIDTKE, G DOLL, H WOODS, TN WORDEN, J CHAKRABARTI, S BE Baker, DN Papitashvili, VO Teague, MJ TI COMPARISON OF SAN-MARCO ASSI SOLAR EUV AND EUV91 MODEL SO SOLAR-TERRESTRIAL ENERGY PROGRAM: INITIAL RESULTS FROM STEP FACILITIES AND THEORY CAMPAIGNS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 1992 STEP Symposium/5th COSPAR Colloquium CY AUG 24-28, 1992 CL JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD SP SCI COMM SOLAR TERRESTRIAL PHYS, NASA, NATL SCI FDN, NATL OCEAN & ATMOSPHER ADM, AIR FORCE GEOPHYS LAB HO JOHNS HOPKINS UNIV, APPL PHYS LAB C1 TELOS, JPL, PASADENA, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042131-8 J9 COSPAR COLL PY 1994 VL 5 BP 73 EP 84 PG 12 WC Astronomy & Astrophysics; Energy & Fuels SC Astronomy & Astrophysics; Energy & Fuels GA BB79N UT WOS:A1994BB79N00010 ER PT B AU MECHERIKUNNEL, A AF MECHERIKUNNEL, A BE Baker, DN Papitashvili, VO Teague, MJ TI SOLAR TOTAL IRRADIANCE DATA FROM EARTH RADIATION BUDGET EXPERIMENT SO SOLAR-TERRESTRIAL ENERGY PROGRAM: INITIAL RESULTS FROM STEP FACILITIES AND THEORY CAMPAIGNS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 1992 STEP Symposium/5th COSPAR Colloquium CY AUG 24-28, 1992 CL JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD SP SCI COMM SOLAR TERRESTRIAL PHYS, NASA, NATL SCI FDN, NATL OCEAN & ATMOSPHER ADM, AIR FORCE GEOPHYS LAB HO JOHNS HOPKINS UNIV, APPL PHYS LAB C1 NASA, GODDARD SPACE FLIGHT CTR, TERR PHYS LAB, GREENBELT, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042131-8 J9 COSPAR COLL PY 1994 VL 5 BP 155 EP 158 PG 4 WC Astronomy & Astrophysics; Energy & Fuels SC Astronomy & Astrophysics; Energy & Fuels GA BB79N UT WOS:A1994BB79N00026 ER PT B AU TSYGANENKO, NA PEREDO, M STERN, DP MALKOV, MV AF TSYGANENKO, NA PEREDO, M STERN, DP MALKOV, MV BE Baker, DN Papitashvili, VO Teague, MJ TI AN EVALUATION OF MAGNETOSPHERIC B-FIELD MODELS BASED ON IMP-HEOS AND ISEE DATASETS SO SOLAR-TERRESTRIAL ENERGY PROGRAM: INITIAL RESULTS FROM STEP FACILITIES AND THEORY CAMPAIGNS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 1992 STEP Symposium/5th COSPAR Colloquium CY AUG 24-28, 1992 CL JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD SP SCI COMM SOLAR TERRESTRIAL PHYS, NASA, NATL SCI FDN, NATL OCEAN & ATMOSPHER ADM, AIR FORCE GEOPHYS LAB HO JOHNS HOPKINS UNIV, APPL PHYS LAB C1 NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, GREENBELT, MD 20771 USA. RI Tsyganenko, Nikolai/J-7377-2012 OI Tsyganenko, Nikolai/0000-0002-5938-1579 NR 0 TC 0 Z9 0 U1 0 U2 3 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042131-8 J9 COSPAR COLL PY 1994 VL 5 BP 275 EP 278 PG 4 WC Astronomy & Astrophysics; Energy & Fuels SC Astronomy & Astrophysics; Energy & Fuels GA BB79N UT WOS:A1994BB79N00046 ER PT B AU PAPITASHVILI, VO TEAGUE, MJ FRIISCHRISTENSEN, E ALLEN, JH AF PAPITASHVILI, VO TEAGUE, MJ FRIISCHRISTENSEN, E ALLEN, JH BE Baker, DN Papitashvili, VO Teague, MJ TI A ONE-MINUTE GEOMAGNETIC DATA-BASE FOR STEP - PROJECT-6.4 SO SOLAR-TERRESTRIAL ENERGY PROGRAM: INITIAL RESULTS FROM STEP FACILITIES AND THEORY CAMPAIGNS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 1992 STEP Symposium/5th COSPAR Colloquium CY AUG 24-28, 1992 CL JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD SP SCI COMM SOLAR TERRESTRIAL PHYS, NASA, NATL SCI FDN, NATL OCEAN & ATMOSPHER ADM, AIR FORCE GEOPHYS LAB HO JOHNS HOPKINS UNIV, APPL PHYS LAB C1 NASA, GODDARD SPACE FLIGHT CTR, US STEP COORDINAT OFF, GREENBELT, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042131-8 J9 COSPAR COLL PY 1994 VL 5 BP 613 EP 622 PG 10 WC Astronomy & Astrophysics; Energy & Fuels SC Astronomy & Astrophysics; Energy & Fuels GA BB79N UT WOS:A1994BB79N00103 ER PT B AU JAMES, NL KING, JH AF JAMES, NL KING, JH BE Baker, DN Papitashvili, VO Teague, MJ TI ONLINE STEP BULLETIN BOARD AT NSSDC SO SOLAR-TERRESTRIAL ENERGY PROGRAM: INITIAL RESULTS FROM STEP FACILITIES AND THEORY CAMPAIGNS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 1992 STEP Symposium/5th COSPAR Colloquium CY AUG 24-28, 1992 CL JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD SP SCI COMM SOLAR TERRESTRIAL PHYS, NASA, NATL SCI FDN, NATL OCEAN & ATMOSPHER ADM, AIR FORCE GEOPHYS LAB HO JOHNS HOPKINS UNIV, APPL PHYS LAB C1 NASA, GODDARD SPACE FLIGHT CTR, NATL SPACE SCI DATA CTR, GREENBELT, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042131-8 J9 COSPAR COLL PY 1994 VL 5 BP 643 EP 646 PG 4 WC Astronomy & Astrophysics; Energy & Fuels SC Astronomy & Astrophysics; Energy & Fuels GA BB79N UT WOS:A1994BB79N00107 ER PT B AU BILITZA, D AF BILITZA, D BE Baker, DN Papitashvili, VO Teague, MJ TI DIRECTORY OF SOLAR-TERRESTRIAL MODELS SO SOLAR-TERRESTRIAL ENERGY PROGRAM: INITIAL RESULTS FROM STEP FACILITIES AND THEORY CAMPAIGNS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 1992 STEP Symposium/5th COSPAR Colloquium CY AUG 24-28, 1992 CL JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD SP SCI COMM SOLAR TERRESTRIAL PHYS, NASA, NATL SCI FDN, NATL OCEAN & ATMOSPHER ADM, AIR FORCE GEOPHYS LAB HO JOHNS HOPKINS UNIV, APPL PHYS LAB C1 NASA, GODDARD SPACE FLIGHT CTR, HUGHES STX, GREENBELT, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042131-8 J9 COSPAR COLL PY 1994 VL 5 BP 663 EP 665 PG 3 WC Astronomy & Astrophysics; Energy & Fuels SC Astronomy & Astrophysics; Energy & Fuels GA BB79N UT WOS:A1994BB79N00110 ER PT B AU GOUCHER, G LOVE, J LECKNER, H AF GOUCHER, G LOVE, J LECKNER, H BE Baker, DN Papitashvili, VO Teague, MJ TI A DISCIPLINE INDEPENDENT SCIENTIFIC-DATA MANAGEMENT PACKAGE - THE NATIONAL SPACE SCIENCE COMMON DATA FORMAT (CDF) SO SOLAR-TERRESTRIAL ENERGY PROGRAM: INITIAL RESULTS FROM STEP FACILITIES AND THEORY CAMPAIGNS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 1992 STEP Symposium/5th COSPAR Colloquium CY AUG 24-28, 1992 CL JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD SP SCI COMM SOLAR TERRESTRIAL PHYS, NASA, NATL SCI FDN, NATL OCEAN & ATMOSPHER ADM, AIR FORCE GEOPHYS LAB HO JOHNS HOPKINS UNIV, APPL PHYS LAB C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042131-8 J9 COSPAR COLL PY 1994 VL 5 BP 691 EP 701 PG 11 WC Astronomy & Astrophysics; Energy & Fuels SC Astronomy & Astrophysics; Energy & Fuels GA BB79N UT WOS:A1994BB79N00115 ER PT B AU RIND, D AF RIND, D BE Baker, DN Papitashvili, VO Teague, MJ TI MODELING OF MIDDLE ATMOSPHERE CLIMATE CHANGES SO SOLAR-TERRESTRIAL ENERGY PROGRAM: INITIAL RESULTS FROM STEP FACILITIES AND THEORY CAMPAIGNS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 1992 STEP Symposium/5th COSPAR Colloquium CY AUG 24-28, 1992 CL JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD SP SCI COMM SOLAR TERRESTRIAL PHYS, NASA, NATL SCI FDN, NATL OCEAN & ATMOSPHER ADM, AIR FORCE GEOPHYS LAB HO JOHNS HOPKINS UNIV, APPL PHYS LAB C1 NASA, GODDARD SPACE FLIGHT CTR, INST SPACE STUDIES, NEW YORK, NY 10025 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042131-8 J9 COSPAR COLL PY 1994 VL 5 BP 759 EP 764 PG 6 WC Astronomy & Astrophysics; Energy & Fuels SC Astronomy & Astrophysics; Energy & Fuels GA BB79N UT WOS:A1994BB79N00122 ER PT J AU ROSENFELD, D ALTEROVITZ, SA AF ROSENFELD, D ALTEROVITZ, SA TI THE EFFECT OF STRAIN ON THE BASE RESISTANCE AND TRANSIT-TIME OF UNGRADED AND COMPOSITIONAL-GRADED SIGE HBTS SO SOLID-STATE ELECTRONICS LA English DT Article ID HETEROJUNCTION BIPOLAR-TRANSISTORS; BAND-GAP; SI1-XGEX; HETEROSTRUCTURES; PERFORMANCE; TRANSPORT; ALLOYS; MODEL AB A theoretical study of the effects of the strain on the base properties of ungraded and compositional-graded n-p-n SiGe Heterojunction Bipolar Transistors is presented. The dependencies of the transverse hole mobility and longitudinal electron mobility upon strain, composition and doping, are formulated using published Monte-Carlo data and, consequently, the base resistance and transit time are modeled and calculated. The results are compared to results obtained using common formulas that ignore these dependencies. The differences between the two sets of results are shown. The paper's conclusion is that for the design, analysis and optimization of high frequency SiGe HBTs the strain effects on the base properties cannot be ignored. C1 TECHNION ISRAEL INST TECHNOL,FAC ELECT ENGN,IL-32000 HAIFA,ISRAEL. RP ROSENFELD, D (reprint author), NASA,LEWIS RES CTR,MAIL STOP 54-5,21000 BROOKPK RD,CLEVELAND,OH 44135, USA. NR 25 TC 15 Z9 24 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JAN PY 1994 VL 37 IS 1 BP 119 EP 126 DI 10.1016/0038-1101(94)90115-5 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA MQ099 UT WOS:A1994MQ09900020 ER PT B AU TUCKER, JH TAPIA, MA AF TUCKER, JH TAPIA, MA GP IEEE TI MINIMUM PARAMETER SOLUTION OF SWITCHING EQUATIONS SO SOUTHEASTCON '94 - CREATIVE TECHNOLOGY TRANSFER - A GLOBAL AFFAIR: PROCEEDINGS OF 1994 IEEE SOUTHEASTCON 94 LA English DT Proceedings Paper CT 1994 IEEE Southeastcon 94 - Creative Technology Transfer: A Global Affair CY APR 10-13, 1994 CL MIAMI, FL SP FLORIDA INT UNIV, DEPT ELECT & COMP ENGN, UNIV MIAMI, DEPT ELECT & COMP ENGIN, IEEE, MIAMI SECT, IEEE, REG 3, IEEE, FLORIDA COUNCIL C1 NASA,LANGLEY RES CTR,DIV FLIGHT ELECTR,HAMPTON,VA 23681. 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 0-7803-1797-1 PY 1994 BP 180 EP 184 PG 5 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Software Engineering; Engineering, Electrical & Electronic; Telecommunications SC Automation & Control Systems; Computer Science; Engineering; Telecommunications GA BA74C UT WOS:A1994BA74C00043 ER PT J AU KOZODEROV, VV DEERING, DW AF KOZODEROV, VV DEERING, DW TI REGIONAL STUDIES OF THE LAND-SURFACE FROM SPACE SO SOVIET JOURNAL OF REMOTE SENSING LA English DT Article AB Regional ecological studies are considered in the context of the global changes problem. The Kursk 91 international experiment is used as an example to illustrate the application of remote sensing data and databases from field experiments to estimate parameters of the state of soil and vegetation cover and subsequently to study the stability of the biosphere based on regular satellite observations. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP KOZODEROV, VV (reprint author), RUSSIAN ACAD SCI,INST COMPUTAT MATH,MOSCOW,RUSSIA. NR 37 TC 0 Z9 0 U1 1 U2 1 PU HARWOOD ACAD PUBL GMBH PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0275-911X J9 SOV J REMOT SENS+ PY 1994 VL 11 IS 2 BP 289 EP 310 PG 22 WC Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology SC Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA PG560 UT WOS:A1994PG56000009 ER PT S AU GOLDIN, DS AF GOLDIN, DS BE May, GL Kramer, SB Korn, P David, L Sprungman, B TI REDESIGN OF THE SPACE STATION - LUNCHEON ADDRESS .2. SO SPACE: A VITAL STIMULUS TO OUR NATIONAL WELL-BEING - 31ST GODDARD MEMORIAL SYMPOSIUM/WORLD SPACE PROGRAMS AND FISCAL REALITY - 30TH GODDARD MEMORIAL SYMPOSIUM SE SCIENCE AND TECHNOLOGY SERIES LA English DT Proceedings Paper CT 31st Goddard Memorial Symposium on Space - A Vital Stimulus to Our National Well-Being CY MAR 09-10, 1993 CL ARLINGTON, VA SP AMER ASTRONAUT SOC C1 NASA,WASHINGTON,DC 20546. 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 0278-4017 BN 0-87703-389-7 J9 SCI TECH PY 1994 VL 83 BP 21 EP 29 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BC20R UT WOS:A1994BC20R00006 ER PT S AU HOLLOWAY, HC AF HOLLOWAY, HC BE May, GL Kramer, SB Korn, P David, L Sprungman, B TI THE CONTRIBUTIONS OF THE SPACE SCIENCES AND ENGINEERING TO HEALTH ON EARTH SO SPACE: A VITAL STIMULUS TO OUR NATIONAL WELL-BEING - 31ST GODDARD MEMORIAL SYMPOSIUM/WORLD SPACE PROGRAMS AND FISCAL REALITY - 30TH GODDARD MEMORIAL SYMPOSIUM SE SCIENCE AND TECHNOLOGY SERIES LA English DT Proceedings Paper CT 31st Goddard Memorial Symposium on Space - A Vital Stimulus to Our National Well-Being CY MAR 09-10, 1993 CL ARLINGTON, VA SP AMER ASTRONAUT SOC C1 NASA,WASHINGTON,DC 20546. 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 0278-4017 BN 0-87703-389-7 J9 SCI TECH PY 1994 VL 83 BP 63 EP 72 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BC20R UT WOS:A1994BC20R00013 ER PT S AU PELLERIN, C AF PELLERIN, C BE May, GL Kramer, SB Korn, P David, L Sprungman, B TI A PROJECTION FOR THE FUTURE SO SPACE: A VITAL STIMULUS TO OUR NATIONAL WELL-BEING - 31ST GODDARD MEMORIAL SYMPOSIUM/WORLD SPACE PROGRAMS AND FISCAL REALITY - 30TH GODDARD MEMORIAL SYMPOSIUM SE SCIENCE AND TECHNOLOGY SERIES LA English DT Proceedings Paper CT 31st Goddard Memorial Symposium on Space - A Vital Stimulus to Our National Well-Being CY MAR 09-10, 1993 CL ARLINGTON, VA SP AMER ASTRONAUT SOC C1 NASA,WASHINGTON,DC 20546. 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 0278-4017 BN 0-87703-389-7 J9 SCI TECH PY 1994 VL 83 BP 99 EP 104 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BC20R UT WOS:A1994BC20R00017 ER PT S AU GRIFFIN, MD AF GRIFFIN, MD BE May, GL Kramer, SB Korn, P David, L Sprungman, B TI IMPLEMENTING THE SPACE EXPLORATION INITIATIVE (SEI) ON AN ANNUAL APPROPRIATION SO SPACE: A VITAL STIMULUS TO OUR NATIONAL WELL-BEING - 31ST GODDARD MEMORIAL SYMPOSIUM/WORLD SPACE PROGRAMS AND FISCAL REALITY - 30TH GODDARD MEMORIAL SYMPOSIUM SE SCIENCE AND TECHNOLOGY SERIES LA English DT Proceedings Paper CT 31st Goddard Memorial Symposium on Space - A Vital Stimulus to Our National Well-Being CY MAR 09-10, 1993 CL ARLINGTON, VA SP AMER ASTRONAUT SOC C1 NASA,WASHINGTON,DC 20546. 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 0278-4017 BN 0-87703-389-7 J9 SCI TECH PY 1994 VL 83 BP 209 EP 216 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BC20R UT WOS:A1994BC20R00030 ER PT B AU STOLARSKI, RS WESOKY, HL AF STOLARSKI, RS WESOKY, HL GP ACAD NATL AIR & ESPACE TI NASAS HIGH SPEED RESEARCH PROGRAM - A STATUS REPORT ON THE ATMOSPHERIC EFFECTS OF STRATOSPHERIC AIRCRAFT SO SPACE, AERONAUTICS AND ATMOSPHERIC ENVIRONMENT, INTERNATIONAL COLLOQUIUM LA English DT Proceedings Paper CT International Colloquium on Space, Aeronautics and Atmospheric Environment CY MAR 15-17, 1994 CL TOULOUSE, FRANCE SP ACAD NATL AIR & ESPACE, ASSOC AERONAUT & ASTRONAUT FRANCE C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RI Stolarski, Richard/B-8499-2013 OI Stolarski, Richard/0000-0001-8722-4012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU CEPADUES EDITIONS PI TOULOUSE PA 111 RUE NICOLAS VAUQUELIN, 31100 TOULOUSE, FRANCE BN 2-85428-359-7 PY 1994 BP 143 EP 153 PG 11 WC Engineering, Aerospace; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BC39R UT WOS:A1994BC39R00008 ER PT B AU BOURGEOIS, B DEKOME, K AF BOURGEOIS, B DEKOME, K BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI ORBITAL DEBRIS TRAJECTORY ERROR MODELING SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,LYNDON B JOHNSON SPACE CTR,DIV TRACKING & COMMUN,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 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 44 EP 51 DI 10.1117/12.177680 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00005 ER PT B AU BOURGEOIS, B AF BOURGEOIS, B BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI PROBABILITY OF SUCCESSFUL COMPLETION OF MICROGRAVITY EXPERIMENTS ONBOARD THE SPACE STATION SUBJECT TO RANDOM ORBITAL DEBRIS COLLISION-AVOIDANCE MANEUVERS SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,LYNDON B JOHNSON SPACE CTR,DIV TRACKING & COMMUN,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 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 52 EP 63 DI 10.1117/12.177648 PG 12 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00006 ER PT B AU ARNDT, GD BOURGEOIS, BA CARL, JR PAZ, I AF ARNDT, GD BOURGEOIS, BA CARL, JR PAZ, I BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI SIGNAL-PROCESSING REQUIREMENTS FOR A SPACE-BORNE RADAR FOR DETECTING ORBITAL DEBRIS SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,LYNDON B JOHNSON SPACE CTR,DIV TRACKING & COMMUN,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 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 102 EP 110 DI 10.1117/12.177652 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00010 ER PT B AU LAURIENTE, M DURAND, RV RUBY, JL AF LAURIENTE, M DURAND, RV RUBY, JL BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI COLLISION PREDICTION FOR ELLIPTIC ORBITS SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS 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 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 111 EP 115 DI 10.1117/12.177653 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00011 ER PT B AU CASANI, EK THOMAS, NW AF CASANI, EK THOMAS, NW BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI THE FLIGHT SYSTEM TESTBED SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 JET PROP LAB,FLIGHT PROJECTS IMPLEMENTAT DEV OFF,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 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 227 EP 236 DI 10.1117/12.177662 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00023 ER PT B AU KAVAYA, MJ SPIERS, GD LOBL, ES ROTHERMEL, J KELLER, VW AF KAVAYA, MJ SPIERS, GD LOBL, ES ROTHERMEL, J KELLER, VW BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI DIRECT GLOBAL MEASUREMENTS OF TROPOSPHERIC WINDS EMPLOYING A SIMPLIFIED COHERENT LASER-RADAR USING FULLY SCALABLE TECHNOLOGY AND TECHNIQUE SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. NR 0 TC 14 Z9 14 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 237 EP 249 DI 10.1117/12.177663 PG 13 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00024 ER PT B AU MEINEL, AB MEINEL, MP BRECKINRIDGE, JB AF MEINEL, AB MEINEL, MP BRECKINRIDGE, JB BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI DEPLOYABLE SPACE TELESCOPES FOR PLANETARY AND ASTRONOMICAL MISSIONS SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 250 EP 256 DI 10.1117/12.177664 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00025 ER PT B AU BANKSTON, CD AF BANKSTON, CD BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI SEDS, EARTH, ATMOSPHERE, AND SPACE IMAGING-SYSTEM (SEASIS) SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. 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 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 257 EP 268 DI 10.1117/12.177665 PG 12 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00026 ER PT B AU BEAUCHAMP, PM BROWN, RH BRUCE, CF CHEN, GS CHRISP, MP FRASCHETTI, GA KRABACH, TN PETRICK, SW RODGERS, DH RODRIGUEZ, J SOLL, SL VAUGHAN, AH SODERBLOM, LA SANDEL, BR YELLE, RV AF BEAUCHAMP, PM BROWN, RH BRUCE, CF CHEN, GS CHRISP, MP FRASCHETTI, GA KRABACH, TN PETRICK, SW RODGERS, DH RODRIGUEZ, J SOLL, SL VAUGHAN, AH SODERBLOM, LA SANDEL, BR YELLE, RV BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI PLUTO INTEGRATED CAMERA SPECTROMETER (PICS) INSTRUMENT SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 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 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 269 EP 277 DI 10.1117/12.177666 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00027 ER PT B AU FAWCETT, SC AF FAWCETT, SC BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI PRODUCTION OF X-RAY OPTICS BY DIAMOND TURNING AND REPLICATION TECHNIQUES SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,OPT FABRICAT BRANCH,HUNTSVILLE,AL 35812. 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 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 278 EP 285 DI 10.1117/12.177667 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00028 ER PT B AU CORDER, EL AF CORDER, EL BE Allahdadi, FA Chrisp, MP Giuliano, CR Latham, WP Shanley, JF TI DEVELOPMENT OF THE SOLAR-X-RAY IMAGER (SXI) CAMERA SO SPACE INSTRUMENTATION AND DUAL-USE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Instrumentation and Dual-Use Technologies CY APR 04-06, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,IMAGING SYST BRANCH,HUNTSVILLE,AL 35812. 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 0-8194-1518-9 J9 P SOC PHOTO-OPT INS PY 1994 VL 2214 BP 294 EP 300 DI 10.1117/12.177669 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BA83P UT WOS:A1994BA83P00030 ER PT B AU MEYER, WV TSCHARNUTER, WW MACGREGOR, AD DAUTET, H DESCHAMPS, P BOUCHER, F ZHU, J TIN, P ROGERS, RB ANSARI, RR AF MEYER, WV TSCHARNUTER, WW MACGREGOR, AD DAUTET, H DESCHAMPS, P BOUCHER, F ZHU, J TIN, P ROGERS, RB ANSARI, RR BE Dewandre, TM SchulteindenBaumen, JJ Sein, E TI LASER-LIGHT SCATTERING, FROM AN ADVANCED TECHNOLOGY DEVELOPMENT PROGRAM TO EXPERIMENTS IN A REDUCED GRAVITY ENVIRONMENT SO SPACE OPTICS 1994: SPACE INSTRUMENTATION AND SPACECRAFT OPTICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Optics 1994: Space Instrumentation and Spacecraft Optics CY APR 18-21, 1994 CL GARMISCH PARTENKIRSCHEN, GERMANY SP COMMISS EUROPEAN COMMUNITIES, DIRECTORATE GEN SCI RES & DEV, CTR NATL ETUDES SPATIALS, EUROPEAN OPT SOC, SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1514-6 J9 P SOC PHOTO-OPT INS PY 1994 VL 2210 BP 196 EP 210 PG 15 WC Engineering, Aerospace; Instruments & Instrumentation; Optics; Telecommunications SC Engineering; Instruments & Instrumentation; Optics; Telecommunications GA BB64E UT WOS:A1994BB64E00019 ER PT B AU ANSARI, RR DHADWAL, HS SUH, KI AF ANSARI, RR DHADWAL, HS SUH, KI BE Dewandre, TM SchulteindenBaumen, JJ Sein, E TI AN INTEGRATED FIBER OPTIC-SYSTEM FOR DYNAMIC LIGHT-SCATTERING MEASUREMENTS IN MICROGRAVITY SO SPACE OPTICS 1994: SPACE INSTRUMENTATION AND SPACECRAFT OPTICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Optics 1994: Space Instrumentation and Spacecraft Optics CY APR 18-21, 1994 CL GARMISCH PARTENKIRSCHEN, GERMANY SP COMMISS EUROPEAN COMMUNITIES, DIRECTORATE GEN SCI RES & DEV, CTR NATL ETUDES SPATIALS, EUROPEAN OPT SOC, SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,LEWIS RES CTR,CWRU,CLEVELAND,OH 44135. 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 0-8194-1514-6 J9 P SOC PHOTO-OPT INS PY 1994 VL 2210 BP 211 EP 222 PG 12 WC Engineering, Aerospace; Instruments & Instrumentation; Optics; Telecommunications SC Engineering; Instruments & Instrumentation; Optics; Telecommunications GA BB64E UT WOS:A1994BB64E00020 ER PT B AU MEYER, WV TIN, P MANN, JA CHEUNG, HM ROGERS, RB LADIGN, L AF MEYER, WV TIN, P MANN, JA CHEUNG, HM ROGERS, RB LADIGN, L BE Dewandre, TM SchulteindenBaumen, JJ Sein, E TI A PREVIEW OF A MODULAR SURFACE LIGHT-SCATTERING INSTRUMENT WITH AUTOTRACKING OPTICS SO SPACE OPTICS 1994: SPACE INSTRUMENTATION AND SPACECRAFT OPTICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Optics 1994: Space Instrumentation and Spacecraft Optics CY APR 18-21, 1994 CL GARMISCH PARTENKIRSCHEN, GERMANY SP COMMISS EUROPEAN COMMUNITIES, DIRECTORATE GEN SCI RES & DEV, CTR NATL ETUDES SPATIALS, EUROPEAN OPT SOC, SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,LEWIS RES CTR,OAI,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1514-6 J9 P SOC PHOTO-OPT INS PY 1994 VL 2210 BP 287 EP 297 PG 11 WC Engineering, Aerospace; Instruments & Instrumentation; Optics; Telecommunications SC Engineering; Instruments & Instrumentation; Optics; Telecommunications GA BB64E UT WOS:A1994BB64E00026 ER PT S AU BRODY, AR AF BRODY, AR BE Heath, GW TI FURTHER ANALYSIS OF EVA SELF-RESCUE DATA SO SPACE SAFETY AND RESCUE 1992: SPACE ACTIVITIES IMPACT ON ENVIRONMENT SE SCIENCE AND TECHNOLOGY SERIES LA English DT Proceedings Paper CT Symposium of the International-Academy-of-Astronautics/World Space Congress - Space Safety and Rescue 1992 CY AUG 28-SEP 05, 1992 CL WASHINGTON, DC SP INT ACAD ASTRONAUT C1 NASA,AMES RES CTR,STERLING SOFTWARE,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 0278-4017 BN 0-87703-392-7 J9 SCI TECH PY 1994 VL 84 BP 113 EP 121 PG 9 WC Engineering, Aerospace SC Engineering GA BC33Q UT WOS:A1994BC33Q00009 ER PT S AU WALTER, LS AF WALTER, LS BE Heath, GW TI THE ROLE AND FUTURE OF SPACE TECHNOLOGY IN DISASTER REDUCTION SO SPACE SAFETY AND RESCUE 1992: SPACE ACTIVITIES IMPACT ON ENVIRONMENT SE SCIENCE AND TECHNOLOGY SERIES LA English DT Proceedings Paper CT Symposium of the International-Academy-of-Astronautics/World Space Congress - Space Safety and Rescue 1992 CY AUG 28-SEP 05, 1992 CL WASHINGTON, DC SP INT ACAD ASTRONAUT C1 NASA,GODDARD SPACE FLIGHT CTR,EARTH SCI DIRECTORATE,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 0278-4017 BN 0-87703-392-7 J9 SCI TECH PY 1994 VL 84 BP 187 EP 203 PG 17 WC Engineering, Aerospace SC Engineering GA BC33Q UT WOS:A1994BC33Q00014 ER PT S AU JEMISON, MC THOMAS, JS AF JEMISON, MC THOMAS, JS BE Heath, GW TI IMPROVING REGIONAL HEALTH CARE IN WEST AFRICA USING CURRENT SPACE SYSTEMS AND TECHNOLOGY SO SPACE SAFETY AND RESCUE 1992: SPACE ACTIVITIES IMPACT ON ENVIRONMENT SE SCIENCE AND TECHNOLOGY SERIES LA English DT Proceedings Paper CT Symposium of the International-Academy-of-Astronautics/World Space Congress - Space Safety and Rescue 1992 CY AUG 28-SEP 05, 1992 CL WASHINGTON, DC SP INT ACAD ASTRONAUT C1 NASA,LYNDON B 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 0278-4017 BN 0-87703-392-7 J9 SCI TECH PY 1994 VL 84 BP 261 EP 271 PG 11 WC Engineering, Aerospace SC Engineering GA BC33Q UT WOS:A1994BC33Q00021 ER PT J AU SCHNEIDER, SJ AF SCHNEIDER, SJ TI LOW THRUST CHEMICAL ROCKET TECHNOLOGY SO SPACE TECHNOLOGY-INDUSTRIAL AND COMMERCIAL APPLICATIONS LA English DT Article; Proceedings Paper CT 43rd International-Astronautical-Federation Congress CY AUG 28-SEP 05, 1992 CL WASHINGTON, DC SP INT ASTRONAUT FEDERAT AB An on-going technology program to improve the performance of low thrust chemical rockets for spacecraft on-board propulsion applications is reviewed. Improved performance and lifetime is sought by the development of new predictive tools to understand the combustion and flow physics, introduction of high temperature materials and improved component designs to optimize performance, and use of higher performance propellants. Improved predictive technology is sought through the comparison of both local and global predictions with experimental data. Predictions are based on both the RPLUS Navier-Stokes code with finite rate kinetics and the JANNAF methodology. Data were obtained with laser-based diagnostics along with global performance measurements. Results indicate that the modeling of the injector and the combustion process needs improvement in these codes and flow visualization with a technique such as two-dimensional laser-induced fluorescence (LIF) would aid in resolving issues of flow symmetry and shear layer combustion processes. High temperature material fabrication processes are under development and small rockets are being designed, fabricated, and tested using these new materials. Rhenium coated with iridium for oxidation protection was produced by the Chemical Vapor Deposition (CVD) process and enabled an 800 K increase in rocket operating temperature. Performance gains with this material in rockets using Earth storable propellants (nitrogen tetroxide and monomethylhydrazine or hydrazine) were obtained through component redesign to eliminate fuel film cooling and its associated combustion inefficiency while managing head end thermal soakback. Material interdiffusion and oxidation characteristics indicated that the requisite lifetimes of tens of hours were available for thruster applications. Rockets were designed, fabricated, and tested with thrusts of 22, 62, 440 and 550 N. Performance improvements of 10 to 20 seconds specific impulse were demonstrated. Higher performance propellants were evaluated. These propellants, defined as space storable propellants, include liquid oxygen (LOX) as.the oxidizer with nitrogen hydrides or hydrocarbons as the fuels. Specifically, a LOX/hydrazine engine was designed, fabricated, and demonstrated to have a 95% theoretical c-star which translates into a projected vacuum specific impulse of 345 s at an area ratio of 204:1. Further performance improvement can be obtained by the use of LOX/hydrogen propellants, especially for manned spacecraft applications, and specific designs must be developed and advanced through flight qualification. RP SCHNEIDER, SJ (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 1 Z9 1 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0892-9270 J9 SPACE TECHNOL JI Space Tech.-Ind. Comm. Appl. PD JAN PY 1994 VL 14 IS 1 BP 31 EP 44 PG 14 WC Engineering, Aerospace SC Engineering GA NQ809 UT WOS:A1994NQ80900004 ER PT J AU BROPHY, JR AF BROPHY, JR TI A SEGMENTED ION ENGINE DESIGN FOR SOLAR ELECTRIC PROPULSION SYSTEMS SO SPACE TECHNOLOGY-INDUSTRIAL AND COMMERCIAL APPLICATIONS LA English DT Article; Proceedings Paper CT 43rd International-Astronautical-Federation Congress CY AUG 28-SEP 05, 1992 CL WASHINGTON, DC SP INT ASTRONAUT FEDERAT AB Solar electric xenon ion propulsion can be used to deliver a substantial quantity of science instruments (of order 100 kg) in rendezvous missions to small bodies such as comets and main belt asteroids with an Atlas IIAS launch vehicle. The performance of the ion propulsion system enables it to deliver typically more than twice the total mass (spacecraft plus science) to the destination in less than half the trip time relative to a chemical/ballistic approach using the same launch vehicle. A new ion engine design referred to as a segmented ion engine is shown to reduce the required ion source life time for these small body rendezvous missions from 18,000 h to approximately 8000 h. This breakthrough, together with the use of SAND ion optics for the engine accelerator system substantially reduces the cost of demonstrating the required engine endurance, a demonstration which has never been accomplished for primary ion propulsion. A flight test of a 5-kW xenon ion propulsion system on the ELITE spacecraft would enormously reduce the cost and risk of using ion propulsion on a planetary vehicle by addressing systems level issues associated with flying a spacecraft radically different from ''traditional'' planetary vehicles. RP BROPHY, JR (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 0 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 0892-9270 J9 SPACE TECHNOL JI Space Tech.-Ind. Comm. Appl. PD JAN PY 1994 VL 14 IS 1 BP 73 EP 80 PG 8 WC Engineering, Aerospace SC Engineering GA NQ809 UT WOS:A1994NQ80900006 ER PT J AU ESCHER, WJD AF ESCHER, WJD TI PROSPECTIVE NEW TRANSPORTATION APPLICATION INITIATIVES IN NASA EARTH-TO-ORBIT PROPULSION TECHNOLOGY PROGRAM SO SPACE TECHNOLOGY-INDUSTRIAL AND COMMERCIAL APPLICATIONS LA English DT Article; Proceedings Paper CT 43rd International-Astronautical-Federation Congress CY AUG 28-SEP 05, 1992 CL WASHINGTON, DC SP INT ASTRONAUT FEDERAT AB NASA's Earth-to-Orbit (ETO) Propulsion Technology Program, a multi-year/multi-task focused technology effort is, today, highly focused on conventional high-thrust cryogenic liquid chemical rocket engines and their envisioned future technology needs. But as highlighted in the U.S. National Ten-Year Space Launch Technology Plan, a set of less-conventional propulsion subjects, ones which offer significant promise for both, improving the state of the art and opening up new propulsion-capability possibilities, is now directed to the space propulsion planning community's attention. In conducting its forward-planning activities, it is highly appropriate that the ETO Program (and other programs as well) carefully consider integrating these ''new initiative'' subjects into the taskwork of future years. After an introductory consideration of the National Plan's propulsion-related directives, followed by a brief background overview of the ETO Program, the following specific new-initiative candidates are discussed from the standpoint of technology-program planning: operationally efficient propulsion systems; high-thrust hybrid rocket propulsion; low-cost, low-pressure expendable propulsion subsystems; advanced cryogenic in-space propulsion systems; integrated modular engine (IME) configured propulsion systems, and combined-cycle airbreathing/rocket propulsion systems. RP ESCHER, WJD (reprint author), NASA HEADQUARTERS,OFF AERONAUT & SPACE TECHNOL,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0892-9270 J9 SPACE TECHNOL JI Space Tech.-Ind. Comm. Appl. PD JAN PY 1994 VL 14 IS 1 BP 81 EP 97 PG 17 WC Engineering, Aerospace SC Engineering GA NQ809 UT WOS:A1994NQ80900007 ER PT S AU SCHEERES, DJ AF SCHEERES, DJ BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI SATELLITE DYNAMICS ABOUT ASTEROIDS SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 19 Z9 20 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 275 EP 292 PN 1&2 PG 18 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00018 ER PT S AU CROOM, CA TOLSON, RH AF CROOM, CA TOLSON, RH BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI USING MAGELLAN ATTITUDE-CONTROL DATA TO STUDY THE VENUSIAN ATMOSPHERE AND VARIOUS SPACECRAFT PROPERTIES SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 GEORGE WASHINGTON UNIV,JOINT INST ADV FLIGHT SCI,NASA LANGLEY RES CTR,HAMPTON,VA 23681. NR 0 TC 3 Z9 3 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 451 EP 467 PN 1&2 PG 17 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00029 ER PT S AU KIEDRON, K AF KIEDRON, K BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI UNIQUE ASPECTS OF THE ULYSSES MISSION SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,MISS DESIGN SECT,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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 469 EP 479 PN 1&2 PG 11 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00030 ER PT S AU WONG, SK GIORGINI, JD YOU, TH LIM, L CHADBOURNE, P AF WONG, SK GIORGINI, JD YOU, TH LIM, L CHADBOURNE, P BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI NAVIGATING THROUGH THE VENUS ATMOSPHERE SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,NAVIGAT SYST SECT,PASADENA,CA 91109. 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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 633 EP 645 PN 1&2 PG 13 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00040 ER PT S AU LYONS, DT AF LYONS, DT BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI AEROBRAKING MAGELLAN - PLAN VERSUS REALITY SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 16 Z9 16 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 663 EP 680 PN 1&2 PG 18 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00042 ER PT S AU LOMAS, JJ HANSON, JM SHRADER, MW AF LOMAS, JJ HANSON, JM SHRADER, MW BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI GUIDANCE AND TARGETING SIMULATION FOR AUTOMATED RENDEZVOUS SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & 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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 745 EP 764 PN 1&2 PG 20 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00047 ER PT S AU HANSON, JM DEATON, AW AF HANSON, JM DEATON, AW BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI GUIDANCE SCHEMES FOR AUTOMATED TERMINAL RENDEZVOUS SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,FLIGHT MECH BRANCH,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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 765 EP 784 PN 1&2 PG 20 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00048 ER PT S AU BHASKARAN, S THURMAN, SW POLLMEIER, VM AF BHASKARAN, S THURMAN, SW POLLMEIER, VM BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI DEMONSTRATION OF A PRECISION DATA REDUCTION TECHNIQUE FOR NAVIGATION OF INTERPLANETARY SPACECRAFT SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,PASADENA,CA 91109. 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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 785 EP 798 PN 1&2 PG 14 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00049 ER PT S AU SHAPIRO, BE BHAT, RS FRAUENHOLZ, RB AF SHAPIRO, BE BHAT, RS FRAUENHOLZ, RB BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI USING ANOMALOUS ALONG-TRACK FORCES TO CONTROL THE TOPEX POSEIDON GROUND TRACK SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,NAVIGAT SYST SECT,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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 799 EP 812 PN 1&2 PG 14 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00050 ER PT S AU MILLER, JK AF MILLER, JK BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI A CONTINUOUS SQUARE-ROOT INFORMATION FILTER-SMOOTHER WITH DISCRETE-DATA UPDATE SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,NAVIGAT SYST 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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 859 EP 859 PN 1&2 PG 1 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00054 ER PT S AU ANTREASIAN, PG NICHOLSON, FT KALLEMEYN, PH BHASKARAN, S HAW, RJ HALAMEK, P AF ANTREASIAN, PG NICHOLSON, FT KALLEMEYN, PH BHASKARAN, S HAW, RJ HALAMEK, P BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI GALILEO ORBIT DETERMINATION FOR THE IDA ENCOUNTER SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 3 Z9 3 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 1027 EP 1048 PN 1&2 PG 22 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00065 ER PT S AU CANGAHUALA, LA GRAAT, EJ ROTH, DC DEMCAK, SW ESPOSITO, PB MASE, RA AF CANGAHUALA, LA GRAAT, EJ ROTH, DC DEMCAK, SW ESPOSITO, PB MASE, RA BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI MARS OBSERVER INTERPLANETARY CRUISE ORBIT DETERMINATION SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,NAVIGAT SYST SECT,PASADENA,CA 91109. 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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 1049 EP 1068 PN 1&2 PG 20 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00066 ER PT S AU TAYLOR, AH IONASESCU, R VAUGHAN, RM AF TAYLOR, AH IONASESCU, R VAUGHAN, RM BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI A 1ST LOOK AT ORBIT DETERMINATION FOR THE CASSINI-MISSION .2. SATURN TOUR SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,NAVIGAT SYST 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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 1069 EP 1088 PN 1&2 PG 20 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00067 ER PT S AU GUINN, JR MCCOLL, KC WILLIAMS, BG WOLFF, PJ YUAN, DN AF GUINN, JR MCCOLL, KC WILLIAMS, BG WOLFF, PJ YUAN, DN BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI PRELIMINARY TOPEX POSEIDON SLR AND GPS STATION COORDINATE CALIBRATION SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,NAVIGAT SYST 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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 1095 EP 1106 PN 1&2 PG 12 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00069 ER PT S AU GUINN, JR LEE, JD MUNSON, TN AF GUINN, JR LEE, JD MUNSON, TN BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI TOPEX POSEIDON ORBIT DETERMINATION USING GLOBAL POSITIONING SATELLITES IN ANTI-SPOOFING MODE SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 1125 EP 1131 PN 1&2 PG 7 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00071 ER PT S AU ESTEFAN, JA BURKHART, D AF ESTEFAN, JA BURKHART, D BE Cochran, JE Edwards, CD Hoffman, SJ Holdaway, R TI SENSITIVITY ANALYSIS OF THE ENHANCED ORBIT DETERMINATION FILTER ERROR BUDGET DEVELOPMENT SO SPACEFLIGHT MECHANICS 1994, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Spaceflight Mechanics Meeting CY FEB 14-16, 1994 CL COCOA BEACH, FL SP AMER ASTRONAUT SOC, AMER ASSOC AERONAUT & ASTRONAUT C1 JET PROP LAB,NAVIGAT SYST SECT,RADIO METR SYST ANAL GRP,PASADENA,CA 91109. 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 0-87703-386-2 J9 ADV ASTRONAUT SCI PY 1994 VL 87 BP 1199 EP 1215 PN 1&2 PG 17 WC Engineering, Aerospace SC Engineering GA BB29U UT WOS:A1994BB29U00076 ER PT J AU SUAREZ, CB CHACKERIAN, C VALERO, F AF SUAREZ, CB CHACKERIAN, C VALERO, F TI HE-BROADENED HALF-WIDTHS MEASUREMENTS OF THE NU(1) AND NU(3) BANDS OF PH3 BETWEEN 2200-CM(1) AND 2400-CM(-1) SO SPECTROSCOPY LETTERS LA English DT Article DE HALF-WIDTHS; FOREIGN BROADENING; PHOSPHINE; JUPITER ID LINE-INTENSITIES; PARAMETERS; PHOSPHINE; SPECTRUM; CH3D; NU-2 AB The He-broadened half-widths of 65 lines of Phosphine in the range of 2200-2400 cm(-1) have been measured at 293 K by means of a Fourier Transform spectrometer at 0.006 cm(-1) resolution. For several experimental conditions related to PH3 and He pressures we used 2 and 5 mm path-length. The broadening coefficients derived using a non-linear fitting technique are reported. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP SUAREZ, CB (reprint author), PROGRAMA QUINOR,CC 962,RA-1900 LA PLATA,BUENOS AIRES,ARGENTINA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 0038-7010 J9 SPECTROSC LETT JI Spectr. Lett. PY 1994 VL 27 IS 8 BP 1065 EP 1072 DI 10.1080/00387019408006654 PG 8 WC Spectroscopy SC Spectroscopy GA PG121 UT WOS:A1994PG12100009 ER PT B AU DINGER, AS AF DINGER, AS BE Breault, RP TI THE SELECTION OF INFRARED BLACK(S) FOR SIRTF - A SURFACE-BY-SURFACE PERFORMANCE COMPARISON SO STRAY RADIATION IN OPTICAL SYSTEMS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Stray Radiation in Optical Systems III Conference CY JUL 26-27, 1994 CL SAN DIEGO, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS DE STRAYLIGHT; SIRTF; INFRARED BLACKS C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. 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 0-8194-1584-7 J9 P SOC PHOTO-OPT INS PY 1994 VL 2260 BP 110 EP 119 DI 10.1117/12.189213 PG 10 WC Optics SC Optics GA BB55H UT WOS:A1994BB55H00012 ER PT B AU SMITH, SM AF SMITH, SM BE Breault, RP TI UNUSUAL BRDF VARIATIONS AT SPECIFIC INFRARED WAVELENGTHS SO STRAY RADIATION IN OPTICAL SYSTEMS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Stray Radiation in Optical Systems III Conference CY JUL 26-27, 1994 CL SAN DIEGO, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS DE BRDF; INFRARED; RESTRAHLEN; ROUGHNESS; AMES24E2; BLACK; MARTIN; INFRABLACK; BERYLLIUM BLACK; REFLECTANCE MEASUREMENT C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1584-7 J9 P SOC PHOTO-OPT INS PY 1994 VL 2260 BP 204 EP 211 DI 10.1117/12.189217 PG 8 WC Optics SC Optics GA BB55H UT WOS:A1994BB55H00023 ER PT J AU NOOR, AK AF NOOR, AK BE Ferguson, NS Wolfe, HF Mei, C TI SOME RECENT ADVANCES IN NONLINEAR VIBRATION AND SENSITIVITY ANALYSIS OF NONLINEAR DYNAMIC RESPONSE SO STRUCTURAL DYNAMICS: RECENT ADVANCES - PROCEEDINGS OF THE 5TH INTERNATIONAL CONFERENCE, VOLS I AND II LA English DT Proceedings Paper CT 5th International Conference on Recent Advances in Structural Dynamics CY JUL 18-21, 1994 CL UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES, SOUTHAMPTON, ENGLAND SP USAF, EUROPEAN OFF AEROSP RES & DEV, WRIGHT PATTERSON AIR FORCE BASE, WRIGHT LABS HO UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES C1 UNIV VIRGINIA,NASA,LANGLEY RES CTR,CTR COMPUTAT STRUCT TECHNOL,HAMPTON,VA 23681. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST SOUND VIBRATION RESEARCH PI SOUTHAMPTON PA THE UNIVERSITY, SOUTHAMPTON, ENGLAND S09 5NH PY 1994 BP 1 EP 37 PG 37 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BC39K UT WOS:A1994BC39K00001 ER PT J AU KAISER, T HANSEN, RS AF KAISER, T HANSEN, RS BE Ferguson, NS Wolfe, HF Mei, C TI EXPERIMENTAL ANALYTICAL APPROACH TO UNDERSTANDING MISTUNING IN A TRANSONIC WIND TUNNEL COMPRESSOR SO STRUCTURAL DYNAMICS: RECENT ADVANCES - PROCEEDINGS OF THE 5TH INTERNATIONAL CONFERENCE, VOLS I AND II LA English DT Proceedings Paper CT 5th International Conference on Recent Advances in Structural Dynamics CY JUL 18-21, 1994 CL UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES, SOUTHAMPTON, ENGLAND SP USAF, EUROPEAN OFF AEROSP RES & DEV, WRIGHT PATTERSON AIR FORCE BASE, WRIGHT LABS HO UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST SOUND VIBRATION RESEARCH PI SOUTHAMPTON PA THE UNIVERSITY, SOUTHAMPTON, ENGLAND S09 5NH PY 1994 BP 515 EP 528 PG 14 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BC39K UT WOS:A1994BC39K00046 ER PT J AU RIZZI, SA DOYLE, JF AF RIZZI, SA DOYLE, JF BE Ferguson, NS Wolfe, HF Mei, C TI DYNAMIC FRACTURE MECHANICS ANALYSIS FOR AN EDGE DELAMINATION CRACK SO STRUCTURAL DYNAMICS: RECENT ADVANCES - PROCEEDINGS OF THE 5TH INTERNATIONAL CONFERENCE, VOLS I AND II LA English DT Proceedings Paper CT 5th International Conference on Recent Advances in Structural Dynamics CY JUL 18-21, 1994 CL UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES, SOUTHAMPTON, ENGLAND SP USAF, EUROPEAN OFF AEROSP RES & DEV, WRIGHT PATTERSON AIR FORCE BASE, WRIGHT LABS HO UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES C1 NASA,LANGLEY RES CTR,STRUCT ACOUST BRANCH,HAMPTON,VA 23681. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST SOUND VIBRATION RESEARCH PI SOUTHAMPTON PA THE UNIVERSITY, SOUTHAMPTON, ENGLAND S09 5NH PY 1994 BP 824 EP 834 PG 11 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BC39K UT WOS:A1994BC39K00075 ER PT J AU MAESTRELLO, L AF MAESTRELLO, L BE Ferguson, NS Wolfe, HF Mei, C TI CONTROL OF SOUND FROM HIGH-SPEED JETS USING AN OSCILLATING LIP AND A POROUS PLUG NOZZLE SO STRUCTURAL DYNAMICS: RECENT ADVANCES - PROCEEDINGS OF THE 5TH INTERNATIONAL CONFERENCE, VOLS I AND II LA English DT Proceedings Paper CT 5th International Conference on Recent Advances in Structural Dynamics CY JUL 18-21, 1994 CL UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES, SOUTHAMPTON, ENGLAND SP USAF, EUROPEAN OFF AEROSP RES & DEV, WRIGHT PATTERSON AIR FORCE BASE, WRIGHT LABS HO UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES C1 NASA,LANGLEY RES CTR,STRUCT ACOUST BRANCH,HAMPTON,VA 23681. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST SOUND VIBRATION RESEARCH PI SOUTHAMPTON PA THE UNIVERSITY, SOUTHAMPTON, ENGLAND S09 5NH PY 1994 BP 1045 EP 1055 PG 11 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BC39K UT WOS:A1994BC39K00095 ER PT B AU MOORE, NR EBBELER, DH SUTHARSHANA, S CREAGER, M AF MOORE, NR EBBELER, DH SUTHARSHANA, S CREAGER, M BE Schueller, GI Shinozuka, M Yao, JTP TI PROBABILISTIC FAILURE RISK ASSESSMENT FOR STRUCTURAL FATIGUE SO STRUCTURAL SAFETY & RELIABILITY, VOLS 1-3: ICOSSAR '93 LA English DT Proceedings Paper CT 6th International Conference on Structural Safety and Reliability (ICOSSAR 93) CY AUG 09-13, 1993 CL INNSBRUCK, AUSTRIA SP INT ASSOC STRUCT SAFETY & RELIABIL, AMER CONCRETE INST, AMER SOC CIVIL ENGNG, EUROPEAN SAFETY & RELIABIL ASSOC, INT ASSOC STRUCT MECH REACTOR TECHNOL, INT ASSOC WIND ENGN, OSTERREICHISCHER INGENIEUR & ARCHITEKTEN VEREIN, REUNION INT LABS ESSAIS & RECH MATERIAUX & CONSTRUCT, SOC MAT SCI, JAPAN, VEREIN DEUT INGENIEURE, VDI GEMEINSCHAFTSAUSSCHUSS IND SYSTEMTECH C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-357-4 PY 1994 BP 1107 EP 1115 PG 9 WC Engineering, Civil; Mechanics SC Engineering; Mechanics GA BA70Y UT WOS:A1994BA70Y00149 ER PT B AU LOU, MC BRENT, DN AF LOU, MC BRENT, DN BE Schueller, GI Shinozuka, M Yao, JTP TI STRUCTURAL SAFETY OF A HUBBLE-SPACE-TELESCOPE SCIENCE INSTRUMENT SO STRUCTURAL SAFETY & RELIABILITY, VOLS 1-3: ICOSSAR '93 LA English DT Proceedings Paper CT 6th International Conference on Structural Safety and Reliability (ICOSSAR 93) CY AUG 09-13, 1993 CL INNSBRUCK, AUSTRIA SP INT ASSOC STRUCT SAFETY & RELIABIL, AMER CONCRETE INST, AMER SOC CIVIL ENGNG, EUROPEAN SAFETY & RELIABIL ASSOC, INT ASSOC STRUCT MECH REACTOR TECHNOL, INT ASSOC WIND ENGN, OSTERREICHISCHER INGENIEUR & ARCHITEKTEN VEREIN, REUNION INT LABS ESSAIS & RECH MATERIAUX & CONSTRUCT, SOC MAT SCI, JAPAN, VEREIN DEUT INGENIEURE, VDI GEMEINSCHAFTSAUSSCHUSS IND SYSTEMTECH C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-357-4 PY 1994 BP 1575 EP 1582 PG 8 WC Engineering, Civil; Mechanics SC Engineering; Mechanics GA BA70Y UT WOS:A1994BA70Y00223 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 AND DAMAGE MECHANISMS IN INCONEL-718 SUPERALLOY SO SUPERALLOYS 718, 625, 706 AND VARIOUS DERIVATIVES LA English DT Proceedings Paper CT 3rd International Special Emphasis Symposium on Superalloys 718, 625, 706 and Various Derivatives CY JUN 27-29, 1994 CL PITTSBURGH, PA SP MINERALS MET & MAT SOC, ASM INT, NATL ASSOC CORROS ENGINEERS C1 NYMA INC,NASA LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 6 Z9 6 U1 0 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 BN 0-87339-235-3 PY 1994 BP 593 EP 606 PG 14 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BB85S UT WOS:A1994BB85S00052 ER PT S AU BAILEY, FR GEORGE, M KOGA, D BUNING, P DELZIO, P KULFAN, R AF BAILEY, FR GEORGE, M KOGA, D BUNING, P DELZIO, P KULFAN, R GP IEEE TI INTEGRATION OF NUMERICAL AND EXPERIMENTAL WIND TUNNELS (IOFNEWT) SO SUPERCOMPUTING '94, PROCEEDINGS SE SUPERCOMPUTING PROCEEDINGS LA English DT Meeting Abstract CT Supercomputing 94 CY NOV 14-18, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, ASSOC COMP MACHINERY, SOC IND & APPL MATH C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 1 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 1063-9535 BN 0-8186-6605-6 J9 SUPERCOMP PROC PY 1994 BP 7 EP 7 PG 1 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA BC13B UT WOS:A1994BC13B00005 ER PT S AU HAINES, M CRONK, D MEHROTRA, P AF HAINES, M CRONK, D MEHROTRA, P GP IEEE TI ON THE DESIGN OF CHANT - A TALKING THREADS PACKAGE SO SUPERCOMPUTING '94, PROCEEDINGS SE SUPERCOMPUTING PROCEEDINGS LA English DT Proceedings Paper CT Supercomputing 94 CY NOV 14-18, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, ASSOC COMP MACHINERY, SOC IND & APPL MATH C1 NASA,LANGLEY RES CTR,INST COMP APPLICAT SCI & ENGN,HAMPTON,VA 23681. NR 0 TC 4 Z9 4 U1 0 U2 1 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 1063-9535 BN 0-8186-6605-6 J9 SUPERCOMP PROC PY 1994 BP 350 EP 359 PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA BC13B UT WOS:A1994BC13B00045 ER PT S AU FATOOHI, R WEERATUNGA, S AF FATOOHI, R WEERATUNGA, S GP IEEE TI PERFORMANCE EVALUATION OF 3 DISTRIBUTED COMPUTING ENVIRONMENTS FOR SCIENTIFIC APPLICATIONS SO SUPERCOMPUTING '94, PROCEEDINGS SE SUPERCOMPUTING PROCEEDINGS LA English DT Proceedings Paper CT Supercomputing 94 CY NOV 14-18, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, ASSOC COMP MACHINERY, SOC IND & APPL MATH C1 NASA,AMES RES CTR,COMP SCI CORP,MOFFETT FIELD,CA 94035. NR 0 TC 2 Z9 3 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 1063-9535 BN 0-8186-6605-6 J9 SUPERCOMP PROC PY 1994 BP 400 EP 409 PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA BC13B UT WOS:A1994BC13B00050 ER PT S AU CASTAGNERA, K CHENG, D FATOOHI, R HOOK, E KRAMER, B MANNING, C MUSCH, J NIGGLEY, C SAPHIR, W SHEPPARD, D SMITH, M STOCKDALE, I WELCH, S WILLIAMS, R YIP, D AF CASTAGNERA, K CHENG, D FATOOHI, R HOOK, E KRAMER, B MANNING, C MUSCH, J NIGGLEY, C SAPHIR, W SHEPPARD, D SMITH, M STOCKDALE, I WELCH, S WILLIAMS, R YIP, D GP IEEE TI NAS EXPERIENCES WITH A PROTOTYPE CLUSTER OF WORKSTATIONS SO SUPERCOMPUTING '94, PROCEEDINGS SE SUPERCOMPUTING PROCEEDINGS LA English DT Proceedings Paper CT Supercomputing 94 CY NOV 14-18, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, ASSOC COMP MACHINERY, SOC IND & APPL MATH C1 NASA,AMES RES CTR,NAS SYST DIV,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 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 1063-9535 BN 0-8186-6605-6 J9 SUPERCOMP PROC PY 1994 BP 410 EP 419 PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA BC13B UT WOS:A1994BC13B00051 ER PT S AU SAINI, S SIMON, HD AF SAINI, S SIMON, HD GP IEEE TI APPLICATIONS PERFORMANCE UNDER OSF/1 AD AND SUNMOS ON INTEL PARAGON XP/S-15 SO SUPERCOMPUTING '94, PROCEEDINGS SE SUPERCOMPUTING PROCEEDINGS LA English DT Proceedings Paper CT Supercomputing 94 CY NOV 14-18, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, ASSOC COMP MACHINERY, SOC IND & APPL MATH C1 NASA,AMES RES CTR,COMP SCI CORP,MOFFETT FIELD,CA 94035. NR 0 TC 2 Z9 2 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 1063-9535 BN 0-8186-6605-6 J9 SUPERCOMP PROC PY 1994 BP 580 EP 589 PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA BC13B UT WOS:A1994BC13B00069 ER PT S AU CHENG, D HOOD, R AF CHENG, D HOOD, R GP IEEE TI A PORTABLE DEBUGGER FOR PARALLEL AND DISTRIBUTED PROGRAMS SO SUPERCOMPUTING '94, PROCEEDINGS SE SUPERCOMPUTING PROCEEDINGS LA English DT Proceedings Paper CT Supercomputing 94 CY NOV 14-18, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, ASSOC COMP MACHINERY, SOC IND & APPL MATH C1 NASA,AMES RES CTR,COMP SCI CORP,MOFFETT FIELD,CA 94035. NR 0 TC 6 Z9 6 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 1063-9535 BN 0-8186-6605-6 J9 SUPERCOMP PROC PY 1994 BP 723 EP 732 PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA BC13B UT WOS:A1994BC13B00085 ER PT B AU MUELLER, CH DICKERSON, RM STAN, MA BHASIN, KB AF MUELLER, CH DICKERSON, RM STAN, MA BHASIN, KB BE Bozovic, I TI MULTILAYERED YBCO-LAALO3-YBCO FILMS FOR MICROWAVE APPLICATIONS SO SUPERCONDUCTING SUPERLATTICES AND MULTILAYERS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Superconducting Superlattices and Multilayers CY JAN 24-25, 1994 CL LOS ANGELES, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NATL AERONAUT & SPACE ADM,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1452-2 J9 P SOC PHOTO-OPT INS PY 1994 VL 2157 BP 211 EP 219 DI 10.1117/12.179148 PG 9 WC Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA BB01Z UT WOS:A1994BB01Z00023 ER PT B AU HUNT, BD FOOTE, MC PIKE, WT BARNER, JB VASQUEZ, RP AF HUNT, BD FOOTE, MC PIKE, WT BARNER, JB VASQUEZ, RP BE Buhrman, RA Clarke, J Daly, K Koch, RH Luine, JA Simon, RW TI MULTILAYER BUFFER SYSTEM FOR FABRICATION OF HIGH-TC EDGE-GEOMETRY SNS WEAK LINKS ON SILICON-ON-SAPPHIRE SUBSTRATES SO SUPERCONDUCTIVE DEVICES AND CIRCUITS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Superconductive Devices and Circuits CY JAN 25-27, 1994 CL LOS ANGELES, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,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 0-8194-1455-7 J9 P SOC PHOTO-OPT INS PY 1994 VL 2160 BP 6 EP 15 DI 10.1117/12.180986 PG 10 WC Physics, Condensed Matter; Polymer Science SC Physics; Polymer Science GA BB27J UT WOS:A1994BB27J00001 ER PT B AU SCHENKER, PS DAS, H OHM, TR AF SCHENKER, PS DAS, H OHM, TR BE Das, H TI DEVELOPMENT OF A NEW HIGH DEXTERITY MANIPULATOR FOR ROBOT ASSISTED MICROSURGERY SO TELEMANIPULATOR AND TELEPRESENCE TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Telemanipulator and Telepresence Technologies CY OCT 31-NOV 01, 1994 CL BOSTON, MA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS, IEEE NCC, VIRTUAL REALITY TECH COMM C1 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 0-8194-1686-X J9 P SOC PHOTO-OPT INS PY 1994 VL 2351 BP 191 EP 198 PG 8 WC Automation & Control Systems; Ergonomics SC Automation & Control Systems; Engineering GA BC13Z UT WOS:A1994BC13Z00018 ER PT B AU COMPTON, MM WOLFE, S AF COMPTON, MM WOLFE, S GP IEEE TI INTELLIGENT VALIDATION AND ROUTING OF ELECTRONIC FORMS IN A DISTRIBUTED WORKFLOW ENVIRONMENT SO TENTH CONFERENCE ON ARTIFICIAL INTELLIGENCE FOR APPLICATIONS, PROCEEDINGS LA English DT Proceedings Paper CT 10th Conference on Artificial Intelligence for Applications CY MAR 01-04, 1994 CL SAN ANTONIO, TX SP IEEE, COMP SOC, TECH COMM PATTERN ANAL & MACHINE INTELLIGENCE, AMER ASSOC ARTIFICIAL INTELLIGENCE C1 NASA,AMES RES CTR,RECOM TECHNOL INC,ARTIFICIAL INTELLIGENCE RES BRANCH,MOFFETT FIELD,CA 94035. NR 0 TC 3 Z9 3 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 0-8186-5550-X PY 1994 BP 125 EP 131 DI 10.1109/CAIA.1994.323683 PG 7 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BA32Q UT WOS:A1994BA32Q00017 ER PT J AU CHAN, P MEESON, B OLSEN, L SERAFINO, G AF CHAN, P MEESON, B OLSEN, L SERAFINO, G GP AMER METEOROL SOC TI AN OVERVIEW OF THE VERSION-0 GODDARD-DISTRIBUTED-ACTIVE-ARCHIVE-CENTER SO TENTH INTERNATIONAL CONFERENCE ON INTERACTIVE INFORMATION AND PROCESSING SYSTEMS FOR METEOROLOGY, OCEANOGRAPHY, AND HYDROLOGY LA English DT Proceedings Paper CT 10th International Conference on Interactive Information and Processing Systems for Meteorology, Oceanography, and Hydrology CY JAN 23-28, 1994 CL NASHVILLE, TN SP AMER METEOROL SOC, WORLD METEOROL ORG, ASSOC AMER GEOGRAPHERS, AMER WATER RESOURCES ASSOC, JOINT OCEANOG INST C1 NASA,GODDARD SPACE FLIGHT CTR,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 1994 BP 254 EP 259 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BC28U UT WOS:A1994BC28U00057 ER PT J AU CAI, Z MUTHARASAN, R KO, F STEINETZ, BM AF CAI, Z MUTHARASAN, R KO, F STEINETZ, BM TI CHARACTERIZING THE LEAKAGE FLOW OF BRAIDED FIBER SEALS SO TEXTILE RESEARCH JOURNAL LA English DT Article ID BEDS AB A new kind of high temperature flexible braided fiber seal has been developed for advanced hypersonic engine applications. Leakage flow experimental observations show that both engine pressure and preload pressure influence leakage flow rate. Although the Reynolds number is relatively small (Re < 10), the mass flow rate comparison of air versus helium reveals that the leakage flow is not viscous dominant. The Ergun equation describing flow through porous media is applied to the flow analysis. The two constants in the Ergun equation, designated as the viscous flow constant C(L) and the inertial flow constant C(T), are determined experimentally. For the leakage flow test setup and the seal geometry, test data show that the values of C(L) and C(T) vary for different seal fiber architectures. The relative magnitude of the non-viscous flow effect can be determined using a dimensionless variable (ReC(T)/C(L)). If this variable is much less than 1, the nonviscous flow effect can be neglected. For the seals tested, the ratio of C(T)/C(L) is at the range of about 1 to 2 in most cases. Therefore the criterion for the viscous dominant flow is Re < 0.1. Predictions of seal leakage flow using the Ergun equation show good agreement with experimental data of both fluid media, air and helium. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP CAI, Z (reprint author), DREXEL UNIV,PHILADELPHIA,PA 19104, USA. RI Mutharasan, Raj/H-2676-2013 OI Mutharasan, Raj/0000-0002-3734-5438 NR 14 TC 1 Z9 1 U1 0 U2 0 PU TEXTILE RESEARCH INST PI PRINCETON PA PO BOX 625, PRINCETON, NJ 08540 SN 0040-5175 J9 TEXT RES J JI Text. Res. J. PD JAN PY 1994 VL 64 IS 1 BP 1 EP 9 DI 10.1177/004051759406400101 PG 9 WC Materials Science, Textiles SC Materials Science GA MU531 UT WOS:A1994MU53100001 ER PT J AU RUBINCAM, DP AF RUBINCAM, DP TI INSOLATION IN TERMS OF EARTH ORBITAL PARAMETERS SO THEORETICAL AND APPLIED CLIMATOLOGY LA English DT Article ID CLIMATE; CYCLES AB The solar insolation at any point on the Earth can be expressed in terms of the latitude and longitude of that point and the parameters of the Earth's orbit. The derivation of such an equation is given here. One purpose of the equation is to pin theoretical insights into how the insolation varies on the time scales of the Milankovitch cycles. The most easily attained insights are that neither the main pacemaker of the ice ages e, nor Milankovitch's precession index e sin omega appear as terms in the equation (e is the eccentricity of the Earth's orbit and omega is the argument of perihelion.) Obliquity does appear. These results are already well-known, but are easily derived when the insolation is formulated as given here. The equation also suggests expressing the Earth's albedo in the same form as the insolation. When this is done a term which looks like e sin omega can be made to appear, for example, multiplied by an albedo coefficient and lagged in phase. However, the term is small, of the order of e2. Besides theoretical insights, a second purpose of the equation is to provide a convenient formula for computing insolation when using numerical climate models. Its usefulness to this end is yet to be established. 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 20 TC 28 Z9 28 U1 1 U2 6 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 1994 VL 48 IS 4 BP 195 EP 202 DI 10.1007/BF00867049 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NA424 UT WOS:A1994NA42400003 ER PT S AU CANNIZZO, JK AF CANNIZZO, JK BE Duschl, WJ Frank, J Meyer, F MeyerHofmeister, E Tscharnuter, WM TI ON THE SEQUENCING OF LONG AND SHORT OUTBURSTS IN DWARF NOVAE SO THEORY OF ACCRETION DISKS - 2 SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES C, MATHEMATICAL AND PHYSICAL SCIENCES LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Theory of Accretion Disks - 2 CY MAR 22-26, 1993 CL MAX PLANCK INST ASTROPHYSIK, GARCHING, GERMANY SP NATO SCI COMM HO MAX PLANCK INST ASTROPHYSIK C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 0 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0258-2023 BN 0-7923-2609-1 J9 NATO ADV SCI INST SE PY 1994 VL 417 BP 125 EP 133 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BZ61H UT WOS:A1994BZ61H00009 ER PT B AU LAMBERT, J BORCHERT, M AF LAMBERT, J BORCHERT, M BE Lakowicz, JR TI INVESTIGATION OF OPTIC-NERVE DEVELOPMENT USING NEURONAL TRACING DYES SO TIME-RESOLVED LASER SPECTROSCOPY IN BIOCHEMISTRY IV, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 4th Biennial Conference on Time-Resolved Laser Spectroscopy in Biochemistry CY JAN 24-26, 1994 CL LOS ANGELES, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS, BRIMROSE CORP, COHERENT LASER GR, HAMAMATSU CORP, ISS, INC, LASER FOCUS WORLD, ICONIX, PHOTON SPECTRA, PROGRAMMED TEST SOURCES, INC, SLM INSTRUMENTS, INC, SPECTRA PHYS LASERS, SPEX IND C1 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 0-8194-1432-8 J9 P SOC PHOTO-OPT INS PY 1994 VL 2137 BP 49 EP 55 DI 10.1117/12.182752 PG 7 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA BB27F UT WOS:A1994BB27F00005 ER PT J AU SIGLER, MF AF SIGLER, MF TI AN ELECTRONIC MEASURING BOARD WITH BAR CODES SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Note ID MEASURING DEVICE AB A measuring board was devised to electronically record fish lengths during surveys at sea. The board is marked in 1-cm increments labeled with bar codes. A fish is placed on the board, and its length is recorded by stroking the bar code at the tip of the tail of the fish with a penlike bar code reader. Large numbers of fish lengths and related data can be recorded quickly and accurately with the board. Electronic data recording eliminates keying and data checking and the data are recorded in a form directly accessible to computers. The electronic measuring board with bar codes is well suited for field use because it is waterproof and has no mechanical parts that can be fouled by fish blood and slime or corroded by seawater. The system is adaptable to recording other categorical data besides length. RP SIGLER, MF (reprint author), NATL MARINE FISHERIES SERV,ALAKA FISHERIES SCI CTR,AUKE BAY LAB,11305 GLACIER HIGHWAY,JUNEAU,AK, USA. NR 6 TC 7 Z9 7 U1 0 U2 2 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD JAN PY 1994 VL 123 IS 1 BP 115 EP 117 DI 10.1577/1548-8659(1994)123<0115:AEMBWB>2.3.CO;2 PG 3 WC Fisheries SC Fisheries GA MR752 UT WOS:A1994MR75200016 ER PT J AU SCHRITZ, B JONES, WR PRAHL, J JANSEN, R AF SCHRITZ, B JONES, WR PRAHL, J JANSEN, R TI PARCHED ELASTOHYDRODYNAMIC LUBRICATION - INSTRUMENTATION AND PROCEDURE SO TRIBOLOGY TRANSACTIONS LA English DT Article DE ELASTOHYDRODYNAMICS; BEARINGS AB A counter rotating bearing rig has been designed and constructed to study transient elastohydrodynamic lubrication phenomena. This paper describes new instrumentation, and documents test procedures. Ball and race speed measurement systems and the capacitance (film thickness) measurement system were upgraded. Methods for measuring bearing torque and race temperatures were implemented. RP SCHRITZ, B (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 13 TC 0 Z9 0 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 1994 VL 37 IS 1 BP 13 EP 22 DI 10.1080/10402009408983261 PG 10 WC Engineering, Mechanical SC Engineering GA MQ622 UT WOS:A1994MQ62200002 ER PT B AU KIMBLE, R BROWN, L FOWLER, W WOODGATE, B YAGELOWICH, J BLOUKE, M DOSLUOGLU, T FERRARA, J DORN, D EBBEN, T MURATASEAWALT, D ORTIZ, R REED, R WOLFE, T AF KIMBLE, R BROWN, L FOWLER, W WOODGATE, B YAGELOWICH, J BLOUKE, M DOSLUOGLU, T FERRARA, J DORN, D EBBEN, T MURATASEAWALT, D ORTIZ, R REED, R WOLFE, T BE Huffman, RE Stergis, CG TI CCD DETECTOR FOR THE SPACE TELESCOPE IMAGING SPECTROGRAPH SO ULTRAVIOLET TECHNOLOGY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Technology V CY JUL 26-27, 1994 CL SAN DIEGO, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS DE CCDS; DETECTORS; HUBBLE SPACE TELESCOPE; SPACE INSTRUMENTATION; SPECTROGRAPHS; UV-ENHANCED CCDS 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 0-8194-1606-1 J9 P SOC PHOTO-OPT INS PY 1994 VL 2282 BP 169 EP 181 DI 10.1117/12.186626 PG 13 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BB54X UT WOS:A1994BB54X00019 ER PT B AU LU, NYY FREUDLING, W AF LU, NYY FREUDLING, W BE Balkowski, C KraanKorteweg, RC TI Large-scale structures in the highly obscured Orion-Taurus region SO UNVEILING LARGE-SCALE STRUCTURES BEHIND THE MILKY WAY SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Unveiling Large-Scale Structures Behind the Milky Way CY JAN 18-21, 1994 CL OBSERV PARIS MEUDON, MEUDON, FRANCE SP Observ Paris, Kapteyn Lab Groningen, CNRS, Univ Paris 7 HO OBSERV PARIS MEUDON C1 CALTECH,JET PROP LAB,IPAC,PASADENA,CA 91125. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 BN 0-937707-86-4 J9 ASTR SOC P PY 1994 VL 67 BP 239 EP 248 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BD49G UT WOS:A1994BD49G00029 ER PT S AU GRIMM, R LUHE, J SCHNEIDER, W AF GRIMM, R LUHE, J SCHNEIDER, W BE Medina, M Borenstein, N TI TOWARDS TRUSTWORTHY COMMUNICATION-SYSTEMS EXPERIENCES WITH THE SECURITY TOOLKIT SECUDE SO UPPER LAYER PROTOCOLS, ARCHITECTURES AND APPLICATIONS SE IFIP TRANSACTIONS C-COMMUNICATION SYSTEMS LA English DT Article; Proceedings Paper CT IFIP TC6/WG6.5 International Conference on Upper Layer Protocols, Architectures and Applications CY JUN 01-03, 1994 CL BARCELONA, SPAIN SP INT FEDERAT INFORMAT PROC, TECH COMM COMMUN SYST DE OPEN COMMUNICATION; SECURITY MODEL FOR OPEN TELECOOPERATION; SOCIAL EMBEDDING OF TECHNICAL SYSTEMS; SECURITY TOOLKIT SECUDE; CRYPTOGRAPHIC FUNCTIONS; SECURE STORAGE; COMPATIBLE SECURITY INFRASTRUCTURE; FIELD EXPERIMENTS AB According to the security model of open telecooperation presented to the last conference ULPAA'92 we identified security mechanisms required to support security services across trust boundaries. Security functions are based on asymmetric digital signatures and encryption schemes, certification infrastructures, authentication procedures due to the authentication framework of X.509, and public Directory access. We implemented the security mechanisms in a security toolkit ''SecuDE''. At application programming interfaces (APIs) the toolkit provides cryptographic functions and secure storage of sensitive data to communication services. This paper presents our experience with the toolkit on the background of our security model. We focus on the implementation of SecuDE, its integration into communication applications, the compatibility of the security functions with other products, and field experiments. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP GRIMM, R (reprint author), INST TELECOOPERAT TECHNOL,GMD,POB 100138,DOLIVOSTR 15,D-64201 DARMSTADT,GERMANY. NR 21 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE PUBL B V PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-549X BN 0-444-82047-7 J9 IFIP TRANS C PY 1994 VL 25 BP 107 EP 120 PG 14 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Theory & Methods; Telecommunications SC Computer Science; Telecommunications GA BB84V UT WOS:A1994BB84V00008 ER PT S AU JAUNCEY, DL REYNOLDS, JE TZIOUMIS, AK FERRIS, RH NORRIS, RP SINCLAIR, MW MIGENES, R GOUGH, RG WARK, RM PRESTON, RA MEIER, DL MURPHY, DW JONES, DL HOARD, DW STJOHN, ME SKJERVE, L KING, EA MCCULLOCH, PM LOVELL, JEJ HAMILTON, PA COSTA, ME BLAIR, DG EDWARDS, P CLAY, RW CAMPBELLWILSON, D AMY, SW MCADAM, WB WHITE, GL JONES, PA NICOLSON, GD AF JAUNCEY, DL REYNOLDS, JE TZIOUMIS, AK FERRIS, RH NORRIS, RP SINCLAIR, MW MIGENES, R GOUGH, RG WARK, RM PRESTON, RA MEIER, DL MURPHY, DW JONES, DL HOARD, DW STJOHN, ME SKJERVE, L KING, EA MCCULLOCH, PM LOVELL, JEJ HAMILTON, PA COSTA, ME BLAIR, DG EDWARDS, P CLAY, RW CAMPBELLWILSON, D AMY, SW MCADAM, WB WHITE, GL JONES, PA NICOLSON, GD BE Robertson, JG Tango, WJ TI THE SOUTHERN-HEMISPHERE VLBI EXPERIMENT PROGRAM, SHEVE SO VERY HIGH ANGULAR RESOLUTION IMAGING SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 158th Symposium of the International Astronomical Union CY JAN 11-15, 1993 CL UNIV SYDNEY, WOMENS COLL, SYDNEY, AUSTRALIA SP INT ASTRON UNION, INT UNION RADIO SCI, COMMONWEALTH DEPT EDUC EMPLOYMENT & TRAINING, AUSTR TELESCOPE NATL FACIL, MT STROMLO AND SIDING SPRING OBSERV, UNIV SYDNEY, SCI FDN PHYS, AUSTRON SOC AUSTR, DONOVAN TRUST HO UNIV SYDNEY, WOMENS COLL DE VLBI; ARRAY AB The Southern Hemisphere VLBI Experiment (SHEVE) program is aimed at producing high-resolution images of southern radio sources. The radio telescopes of the present SHEVE array are described below and some recent results presented. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV TASMANIA,HOBART,TAS 7001,AUSTRALIA. UNIV WESTERN AUSTRALIA,NEDLANDS,WA 6009,AUSTRALIA. UNIV ADELAIDE,ADELAIDE,SA 5001,AUSTRALIA. UNIV SYDNEY,SYDNEY,NSW 2006,AUSTRALIA. UNIV WESTERN SYDNEY NEPEAN,KINGSWOOD,NSW,AUSTRALIA. HARTEBEESTHOEK RADIO ASTRON OBSERV,KRUGERSDORP,SOUTH AFRICA. RP JAUNCEY, DL (reprint author), CSIRO,AUSTRALIA TELESCOPE NATL FACIL,CANBERRA,ACT,AUSTRALIA. RI King, Edward/A-1473-2012; Norris, Ray/A-1316-2008; Migenes, Victor/F-3157-2015 OI King, Edward/0000-0002-6898-2130; Norris, Ray/0000-0002-4597-1906; Migenes, Victor/0000-0002-7990-2191 NR 11 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-2632-6 J9 IAU SYMP PY 1994 IS 158 BP 131 EP 133 PG 3 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BA03G UT WOS:A1994BA03G00018 ER PT S AU HINES, B NEAT, G COLAVITA, MM CALVET, R SWORD, L AF HINES, B NEAT, G COLAVITA, MM CALVET, R SWORD, L BE Robertson, JG Tango, WJ TI THE MICRO-PRECISION INTERFEROMETER TESTBED INSTRUMENT DESIGN SO VERY HIGH ANGULAR RESOLUTION IMAGING SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 158th Symposium of the International Astronomical Union CY JAN 11-15, 1993 CL UNIV SYDNEY, WOMENS COLL, SYDNEY, AUSTRALIA SP INT ASTRON UNION, INT UNION RADIO SCI, COMMONWEALTH DEPT EDUC EMPLOYMENT & TRAINING, AUSTR TELESCOPE NATL FACIL, MT STROMLO AND SIDING SPRING OBSERV, UNIV SYDNEY, SCI FDN PHYS, AUSTRON SOC AUSTR, DONOVAN TRUST HO UNIV SYDNEY, WOMENS COLL DE MPI; OPTICAL INTERFEROMETRY; INTERFEROMETER TESTBED; SPACE-BASED INTERFEROMETRY AB The Micro-Precision Interferometer Testbed is essentially a space-based Michelson interferometer suspended in a ground-based laboratory. The purpose of the testbed is to serve as a proving ground for technologies needed for future space-based missions requiring low-vibration environments. A layered control architecture, utilizing isolation, structural control, and active optical control technologies, allows the system to achieve its vibration attenuation goals. This paper focuses primarily on the interferometer instrument design for the testbed and the systems-level tradeoffs between the instrument and other systems due to the fact that the interferometer is on a large, lightly damped, flexible structure rather than on the ground. The testbed is designed to be a fully functioning interferometer spacecraft and makes use of flight-like hardware where possible, including an external star simulator, an attitude control system, fringe detection and tracking systems, delay lines, pointing control, laser metrology systems, and computers and electronic subsystems. The engineering decisions that led to the current instrument configuration are presented and explained. RP HINES, B (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 7 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 0-7923-2632-6 J9 IAU SYMP PY 1994 IS 158 BP 193 EP 195 PG 3 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BA03G UT WOS:A1994BA03G00031 ER PT S AU LIVINGSTON, W KOPP, G GEZARI, D VAROSI, F AF LIVINGSTON, W KOPP, G GEZARI, D VAROSI, F BE Robertson, JG Tango, WJ TI OBSERVATIONS OF SEEING AT 0.5-MU-M AND 12.4-MU-M SO VERY HIGH ANGULAR RESOLUTION IMAGING SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 158th Symposium of the International Astronomical Union CY JAN 11-15, 1993 CL UNIV SYDNEY, WOMENS COLL, SYDNEY, AUSTRALIA SP INT ASTRON UNION, INT UNION RADIO SCI, COMMONWEALTH DEPT EDUC EMPLOYMENT & TRAINING, AUSTR TELESCOPE NATL FACIL, MT STROMLO AND SIDING SPRING OBSERV, UNIV SYDNEY, SCI FDN PHYS, AUSTRON SOC AUSTR, DONOVAN TRUST HO UNIV SYDNEY, WOMENS COLL DE SEEING; INFRARED; SOLAR AB A variety of observations have been made of solar features (sunspots, faculae, the Limb) using both array and single element scanning techniques. The telescope was the 1.6 m McMath-Pierce on Kitt Peak. Array data were acquired with a 58x62 pixel Si:Ga detector at 4.8, 7.8, 12.4, and 18 mu m, while a CCD camera recorded the same image position at 0.5 mu m. In a separate experiment, a nutating mirror device was used to generate a raster scan of solar disk areas, the output being fed to a Si PIN diode (0.5 mu m filter) and a As:Si diode (12.4 mu m filter). The scanner data yield simultaneous images at the two wavelengths and was essentially a repeat of the 1970 Turon-Lena experiment with updated equipment. Examples of images at the various wavelengths are given in the poster. Analysis of the data is incomplete at this time. We can report that the effects of seeing were encountered at all wavelengths, including 18 mu m, even though conditions were deemed good at times (for example, penumbral filaments were resolved in sunspots). We have thus been unable to verify, as yet, the conditions reported by Pester et al, in which exceptional seeing is realized in the infrared. C1 NASA,GODDARD SPACE FLIGHT CTR,INFRARED ASTROPHYS BRANCH,GREENBELT,MD 20771. RP LIVINGSTON, W (reprint author), NATL SOLAR OBSERV,POB 26732,TUCSON,AZ 85726, USA. NR 7 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 0-7923-2632-6 J9 IAU SYMP PY 1994 IS 158 BP 299 EP 301 PG 3 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BA03G UT WOS:A1994BA03G00051 ER PT S AU SHAO, M AF SHAO, M BE Robertson, JG Tango, WJ TI FRINGE VISIBILITY AND PHASE MEASUREMENTS SO VERY HIGH ANGULAR RESOLUTION IMAGING SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 158th Symposium of the International Astronomical Union CY JAN 11-15, 1993 CL UNIV SYDNEY, WOMENS COLL, SYDNEY, AUSTRALIA SP INT ASTRON UNION, INT UNION RADIO SCI, COMMONWEALTH DEPT EDUC EMPLOYMENT & TRAINING, AUSTR TELESCOPE NATL FACIL, MT STROMLO AND SIDING SPRING OBSERV, UNIV SYDNEY, SCI FDN PHYS, AUSTRON SOC AUSTR, DONOVAN TRUST HO UNIV SYDNEY, WOMENS COLL AB At optical wavelengths there are a wide variety of techniques to detect interference fringes. Because detectors in the visible/IR are energy detectors, the fringe amplitude and phase must be encoded in some manner. Two fundamentally different methods are temporal and spatial encoding. This paper briefly describes the various techniques that have been used in operational interferometers along with their advantages and disadvantages. Several fringe detectors for next-generation interferometers will also be described. These fringe detectors often combine multiple functions, such as spectroscopy and multi-beam combination. RP SHAO, M (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-2632-6 J9 IAU SYMP PY 1994 IS 158 BP 311 EP 316 PG 6 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BA03G UT WOS:A1994BA03G00055 ER PT S AU DANCHI, WC GREENHILL, L BESTER, M TOWNES, CH WOLFIRE, MG AF DANCHI, WC GREENHILL, L BESTER, M TOWNES, CH WOLFIRE, MG BE Robertson, JG Tango, WJ TI LONG-BASE-LINE INTERFEROMETRIC OBSERVATIONS OF CIRCUMSTELLAR DUST SHELLS AT 11 MICRONS SO VERY HIGH ANGULAR RESOLUTION IMAGING SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 158th Symposium of the International Astronomical Union CY JAN 11-15, 1993 CL UNIV SYDNEY, WOMENS COLL, SYDNEY, AUSTRALIA SP INT ASTRON UNION, INT UNION RADIO SCI, COMMONWEALTH DEPT EDUC EMPLOYMENT & TRAINING, AUSTR TELESCOPE NATL FACIL, MT STROMLO AND SIDING SPRING OBSERV, UNIV SYDNEY, SCI FDN PHYS, AUSTRON SOC AUSTR, DONOVAN TRUST HO UNIV SYDNEY, WOMENS COLL DE INTERFEROMETRY; DUST FORMATION; VARIABLE STARS; MASS LOSS ID OPTICAL-PROPERTIES; GRAINS AB The spatial distribution of dust around a sample of well-known late-type stars has been studied with the Infrared Spatial Interferometer (ISI) located at Mt. Wilson. Currently operating with a single baseline as a heterodyne interferometer at 11.15 mu m, the ISI has obtained visibility curves of these stars. Radiative transfer modeling of the visibility curves has yielded estimates of the inner radii of the dust shells, the optical depth at 11 mu m, and the temperature of the dust at the inner radii. For stars in which the dust is resolved, estimates of the stellar diameter and temperature can also be made. Broadly speaking two classes of stars have been found. One class has inner radii of their dust shells very close to the photospheres of the stars themselves (3-5 stellar radii) and at a higher temperature (similar to 1200 K) than previously measured. This class includes VY CMa, NML Tau, IRC +10216, and omicron Ceti. For the latter two the visibility curves change with the luminosity phase of the star and new dust appears to form at still smaller radii during minimum luminosity. The second class of stars has dust shells with substantially larger inner radii and very little dust close to the stars, and includes alpha Ori, alpha Sco, alpha Her, R Leo, and chi Cyg. This indicates sporadic production of dust and no dust formation within the last several decades. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035. RP DANCHI, WC (reprint author), UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720, USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-2632-6 J9 IAU SYMP PY 1994 IS 158 BP 383 EP 386 PG 4 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BA03G UT WOS:A1994BA03G00074 ER PT S AU PAN, XP SHAO, M COLAVITA, MM AF PAN, XP SHAO, M COLAVITA, MM BE Robertson, JG Tango, WJ TI HIGH-RESOLUTION INTERFEROMETRIC OBSERVATIONS OF ECLIPSING BINARY STARS SO VERY HIGH ANGULAR RESOLUTION IMAGING SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 158th Symposium of the International Astronomical Union CY JAN 11-15, 1993 CL UNIV SYDNEY, WOMENS COLL, SYDNEY, AUSTRALIA SP INT ASTRON UNION, INT UNION RADIO SCI, COMMONWEALTH DEPT EDUC EMPLOYMENT & TRAINING, AUSTR TELESCOPE NATL FACIL, MT STROMLO AND SIDING SPRING OBSERV, UNIV SYDNEY, SCI FDN PHYS, AUSTRON SOC AUSTR, DONOVAN TRUST HO UNIV SYDNEY, WOMENS COLL C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP PAN, XP (reprint author), CALTECH,PASADENA,CA 91125, USA. NR 2 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 0-7923-2632-6 J9 IAU SYMP PY 1994 IS 158 BP 413 EP 415 PG 3 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BA03G UT WOS:A1994BA03G00083 ER PT S AU MUHLEMAN, DO BUTLER, BJ SLADE, MA GROSSMAN, AW AF MUHLEMAN, DO BUTLER, BJ SLADE, MA GROSSMAN, AW BE Robertson, JG Tango, WJ TI RADAR IMAGING OF THE PLANETS USING THE VERY LARGE ARRAY SO VERY HIGH ANGULAR RESOLUTION IMAGING SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 158th Symposium of the International Astronomical Union CY JAN 11-15, 1993 CL UNIV SYDNEY, WOMENS COLL, SYDNEY, AUSTRALIA SP INT ASTRON UNION, INT UNION RADIO SCI, COMMONWEALTH DEPT EDUC EMPLOYMENT & TRAINING, AUSTR TELESCOPE NATL FACIL, MT STROMLO AND SIDING SPRING OBSERV, UNIV SYDNEY, SCI FDN PHYS, AUSTRON SOC AUSTR, DONOVAN TRUST HO UNIV SYDNEY, WOMENS COLL ID IMAGES C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV MARYLAND,COLL PK,MD 20742. RP MUHLEMAN, DO (reprint author), CALTECH,PASADENA,CA 91125, USA. NR 6 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 0-7923-2632-6 J9 IAU SYMP PY 1994 IS 158 BP 457 EP 468 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BA03G UT WOS:A1994BA03G00093 ER PT S AU COLAVITA, MM AF COLAVITA, MM BE Robertson, JG Tango, WJ TI LIMITATIONS TO OPTICAL IR INTERFEROMETRY FROM THE GROUND AND SPACE SO VERY HIGH ANGULAR RESOLUTION IMAGING SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 158th Symposium of the International Astronomical Union CY JAN 11-15, 1993 CL UNIV SYDNEY, WOMENS COLL, SYDNEY, AUSTRALIA SP INT ASTRON UNION, INT UNION RADIO SCI, COMMONWEALTH DEPT EDUC EMPLOYMENT & TRAINING, AUSTR TELESCOPE NATL FACIL, MT STROMLO AND SIDING SPRING OBSERV, UNIV SYDNEY, SCI FDN PHYS, AUSTRON SOC AUSTR, DONOVAN TRUST HO UNIV SYDNEY, WOMENS COLL DE LONG-BASE-LINE INTERFEROMETRY; INTERFEROMETRIC IMAGING; ASTROMETRY; ATMOSPHERIC EFFECTS ID LASER GUIDE-STAR AB The primary limitation to ground-based optical/IR interferometry is the turbulent atmosphere, which limits sensitivity by restricting the coherence volume, limits imaging accuracy by corrupting the fringe phase, and Limits astrometric accuracy by corrupting the angle of arrival. Various advanced techniques can be used to circumvent these Limits to some extent. Sensitivity can be increased with adaptive optics and laser guide stars, which should eventually be able to phase the individual apertures of an interferometer down to some cutoff wavelength, Limited by tilt sensing. However, the sky coverage for cophasing the interferometer on an arbitrary object will remain limited at short wavelengths. For imaging, closure-phase techniques, well established in radio interferometry, will be used in next-generation instruments. However, for maximum sensitivity on extended objects, redundant arrays will be needed to cophase the interferometer. For astrometry, the limits to wide-field astrometry set by the atmosphere can be reduced somewhat with two-color techniques, but otherwise do not seem reducible by the techniques now being discussed. However, over narrow fields, the astrometric performance of an interferometer can be quite good. In space, without the corruptions of the atmosphere, the fundamental limitation is photon noise. However, technical issues such as metrology accuracy and practical issues such as maximum affordable baseline length will also limit performance. RP COLAVITA, MM (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91101, USA. NR 7 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 0-7923-2632-6 J9 IAU SYMP PY 1994 IS 158 BP 469 EP 476 PG 8 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BA03G UT WOS:A1994BA03G00094 ER PT B AU SPANOS, J RAHMAN, Z AF SPANOS, J RAHMAN, Z BE Gordon, CG TI NARROW-BAND CONTROL EXPERIMENTS IN ACTIVE VIBRATION ISOLATION SO VIBRATION MONITORING AND CONTROL SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Vibration Monitoring and Control CY JUL 28-29, 1994 CL SAN DIEGO, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS DE VIBRATION ISOLATION; ADAPTIVE CONTROL; TRACKING NOTCH FILTER; SPACE STRUCTURES C1 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 0-8194-1588-X J9 P SOC PHOTO-OPT INS PY 1994 VL 2264 BP 13 EP 19 DI 10.1117/12.188862 PG 7 WC Automation & Control Systems; Engineering, Mechanical; Remote Sensing SC Automation & Control Systems; Engineering; Remote Sensing GA BB55G UT WOS:A1994BB55G00002 ER PT B AU CHILDERS, BA SNOW, WL SHORTIS, MR AF CHILDERS, BA SNOW, WL SHORTIS, MR BE ElHakim, SF TI A VIDEOMETRIC SYSTEM USING VITC FOR COMPUTER-AIDED IMAGE MANAGEMENT SO VIDEOMETRICS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Videometrics CY NOV 02-04, 1994 CL BOSTON, MA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS, INT SOC PHOTOGRAMMETRY & REMOTE SENSING C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. 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 0-8194-1685-1 J9 P SOC PHOTO-OPT INS PY 1994 VL 2350 BP 93 EP 97 DI 10.1117/12.189148 PG 5 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BB57X UT WOS:A1994BB57X00009 ER PT B AU WELCH, SS AF WELCH, SS BE ElHakim, SF TI DESIGN AND PERFORMANCE OF AN OPTICAL MEASUREMENT SYSTEM FOR POSITION MEASUREMENT AND CONTROL IN A LARGE GAP MAGNETIC SUSPENSION SYSTEM SO VIDEOMETRICS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Videometrics CY NOV 02-04, 1994 CL BOSTON, MA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS, INT SOC PHOTOGRAMMETRY & REMOTE SENSING DE POSITION MEASUREMENT; LINEAR CHARGE-COUPLED DEVICES; CLOSE-RANGE PHOTOGRAMMETRY; PARALLEL PROCESSING C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. 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 0-8194-1685-1 J9 P SOC PHOTO-OPT INS PY 1994 VL 2350 BP 115 EP 126 DI 10.1117/12.189125 PG 12 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BB57X UT WOS:A1994BB57X00012 ER PT B AU SNOW, WL CHILDERS, BA AF SNOW, WL CHILDERS, BA BE ElHakim, SF TI MODE SHAPE-ANALYSIS USING A COMMERCIALLY AVAILABLE PEAK STORE VIDEO FRAME BUFFER SO VIDEOMETRICS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Videometrics CY NOV 02-04, 1994 CL BOSTON, MA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS, INT SOC PHOTOGRAMMETRY & REMOTE SENSING DE MODAL ANALYSIS; FRAME BUFFER; CLOSE-RANGE PHOTOGRAMMETRY; CALIBRATION; MOTION ANALYSIS C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. 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 0-8194-1685-1 J9 P SOC PHOTO-OPT INS PY 1994 VL 2350 BP 128 EP 135 DI 10.1117/12.189126 PG 8 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BB57X UT WOS:A1994BB57X00013 ER PT B AU HEAP, SR AF HEAP, SR BE TenorioTagle, G TI THE STARBURST NUCLEUS OF M83 SO VIOLENT STAR FORMATION: FROM 30 DORADUS TO QSOS LA English DT Proceedings Paper CT 1st IAC-RGO Meeting on Violent Star Formation from 30 Doradus to QSOs CY NOV 08-12, 1993 CL PUERTO NAOS LA PALMA, SPAIN SP INST ASTROFIS CANARIAS, ROYAL GREENWICH OBSERVATORY C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RI heap, sara/E-2237-2012 NR 0 TC 4 Z9 4 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI CAMBRIDGE PA THE PITT BUILDING, TRUMPINGTON ST, CAMBRIDGE, CAMBS, ENGLAND CB2 1RP BN 0-521-47277-6 PY 1994 BP 303 EP 308 DI 10.1017/CBO9780511600159.054 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BD07A UT WOS:A1994BD07A00053 ER PT B AU MAJANI, E AF MAJANI, E BE Katsaggelos, AK TI BIORTHOGONAL WAVELETS FOR IMAGE COMPRESSION SO VISUAL COMMUNICATIONS AND IMAGE PROCESSING '94, PTS 1-3 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Communications and Image Processing 94 CY SEP 25-29, 1994 CL CHICAGO, IL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS, IEEE, CIRCUITS & SYST SOC, EUROPEAN ASSOC SIGNAL PROC, OPT SOC AMER DE DATA COMPRESSION; CODING GAIN; BIORTHOGONAL; LINEAR PHASE; OPTIMIZATION; MAXIMALLY REGULAR C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 6 Z9 6 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1638-X J9 P SOC PHOTO-OPT INS PY 1994 VL 2308 BP 478 EP 488 DI 10.1117/12.185990 PG 11 WC Computer Science, Software Engineering; Optics; Telecommunications SC Computer Science; Optics; Telecommunications GA BB66K UT WOS:A1994BB66K00044 ER PT B AU ASIMOV, D BUJA, A AF ASIMOV, D BUJA, A BE Moorhead, RJ Silver, DE Uselton, SP TI THE GRAND-TOUR VIA GEODESIC INTERPOLATION OF 2-FRAMES SO VISUAL DATA EXPLORATION AND ANALYSIS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Data Exploration and Analysis CY FEB 07-08, 1994 CL SAN JOSE, CA SP SOC IMAGING SCI & TECHNOL, SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,AMES RES CTR,COMP SCI CORP,MT VIEW,CA 94305. 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 0-8194-1473-5 J9 P SOC PHOTO-OPT INS PY 1994 VL 2178 BP 145 EP 153 DI 10.1117/12.172065 PG 9 WC Optics SC Optics GA BA43S UT WOS:A1994BA43S00016 ER PT B AU JUDAY, RD BARTON, RS JOHNSON, CD LOSHIN, DS AF JUDAY, RD BARTON, RS JOHNSON, CD LOSHIN, DS BE Huck, FO Juday, RD TI CONFORMAL AND OTHER IMAGE WARPINGS FOR READING WITH FIELD DEFECT SO VISUAL INFORMATION PROCESSING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing III CY APR 04-05, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,LYNDON B JOHNSON SPACE CTR,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 0-8194-1543-X J9 P SOC PHOTO-OPT INS PY 1994 VL 2239 BP 92 EP 102 DI 10.1117/12.179299 PG 11 WC Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BB06Z UT WOS:A1994BB06Z00008 ER PT B AU HUCK, FO FALES, CL JOBSON, DJ RAHMAN, ZU AF HUCK, FO FALES, CL JOBSON, DJ RAHMAN, ZU BE Huck, FO Juday, RD TI ELECTROOPTICAL DESIGN FOR EFFICIENT VISUAL COMMUNICATION SO VISUAL INFORMATION PROCESSING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing III CY APR 04-05, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. 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 0-8194-1543-X J9 P SOC PHOTO-OPT INS PY 1994 VL 2239 BP 141 EP 156 DI 10.1117/12.179277 PG 16 WC Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BB06Z UT WOS:A1994BB06Z00012 ER PT B AU JUDAY, RD KNOPP, J SOUTAR, C BARTON, RS AF JUDAY, RD KNOPP, J SOUTAR, C BARTON, RS BE Huck, FO Juday, RD TI PARTIAL ROTATION INVARIANCE IN RETINAL PATTERN-RECOGNITION SO VISUAL INFORMATION PROCESSING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing III CY APR 04-05, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. 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 0-8194-1543-X J9 P SOC PHOTO-OPT INS PY 1994 VL 2239 BP 157 EP 166 DI 10.1117/12.179281 PG 10 WC Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BB06Z UT WOS:A1994BB06Z00013 ER PT S AU MA, KL ZHENG, ZC AF MA, KL ZHENG, ZC GP IEEE TI 3D VISUALIZATION OF UNSTEADY 2D AIRPLANE WAKE VORTICES SO VISUALIZATION '94, PROCEEDINGS SE IEEE CONFERENCE ON VISUALIZATION LA English DT Proceedings Paper CT Visualization 94 Conference CY OCT 17-21, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, TECH COMM COMP GRAPH, ASSOC COMP MACHINERY, SPECIAL INTEREST GRP GRAPH C1 NASA,LANGLEY RES CTR,ICASE,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 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 0-8186-6627-7 J9 IEEE VISUAL PY 1994 BP 124 EP & PG 0 WC Computer Science, Software Engineering SC Computer Science GA BC60D UT WOS:A1994BC60D00021 ER PT S AU BANKS, DC SINGER, BA AF BANKS, DC SINGER, BA GP IEEE TI VORTEX TUBES IN TURBULENT FLOWS - IDENTIFICATION, REPRESENTATION, RECONSTRUCTION SO VISUALIZATION '94, PROCEEDINGS SE IEEE CONFERENCE ON VISUALIZATION LA English DT Proceedings Paper CT Visualization 94 Conference CY OCT 17-21, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, TECH COMM COMP GRAPH, ASSOC COMP MACHINERY, SPECIAL INTEREST GRP GRAPH C1 NASA,LANGLEY RES CTR,INST COMP APPLICAT SCI & ENGN,HAMPTON,VA 23681. NR 0 TC 5 Z9 5 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 0-8186-6627-7 J9 IEEE VISUAL PY 1994 BP 132 EP & PG 0 WC Computer Science, Software Engineering SC Computer Science GA BC60D UT WOS:A1994BC60D00022 ER PT S AU TWIDDY, R CAVALLO, J SHIRI, SM AF TWIDDY, R CAVALLO, J SHIRI, SM GP IEEE TI RESTORER - A VISUALIZATION TECHNIQUE FOR HANDLING MISSING DATA SO VISUALIZATION '94, PROCEEDINGS SE IEEE CONFERENCE ON VISUALIZATION LA English DT Proceedings Paper CT Visualization 94 Conference CY OCT 17-21, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, TECH COMM COMP GRAPH, ASSOC COMP MACHINERY, SPECIAL INTEREST GRP GRAPH C1 HUGHES STX CORP,NASA,GODDARD SPACE FLIGHT CTR,SCI VISUALIZAT STUDIO,GREENBELT,MD 20771. NR 0 TC 2 Z9 2 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 0-8186-6627-7 J9 IEEE VISUAL PY 1994 BP 212 EP & PG 0 WC Computer Science, Software Engineering SC Computer Science GA BC60D UT WOS:A1994BC60D00032 ER PT S AU LANE, DA AF LANE, DA GP IEEE TI UFAT - A PARTICLE TRACER FOR TIME-DEPENDENT FLOW FIELDS SO VISUALIZATION '94, PROCEEDINGS SE IEEE CONFERENCE ON VISUALIZATION LA English DT Proceedings Paper CT Visualization 94 Conference CY OCT 17-21, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, TECH COMM COMP GRAPH, ASSOC COMP MACHINERY, SPECIAL INTEREST GRP GRAPH C1 COMP SCI CORP,NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 3 Z9 3 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 0-8186-6627-7 J9 IEEE VISUAL PY 1994 BP 257 EP & PG 0 WC Computer Science, Software Engineering SC Computer Science GA BC60D UT WOS:A1994BC60D00038 ER PT S AU USELTON, S DORN, G FARHAT, C VANNIER, M ESBENSEN, K AF USELTON, S DORN, G FARHAT, C VANNIER, M ESBENSEN, K GP IEEE TI VALIDATION, VERIFICATION AND EVALUATION SO VISUALIZATION '94, PROCEEDINGS SE IEEE CONFERENCE ON VISUALIZATION LA English DT Proceedings Paper CT Visualization 94 Conference CY OCT 17-21, 1994 CL WASHINGTON, DC SP IEEE, COMP SOC, TECH COMM COMP GRAPH, ASSOC COMP MACHINERY, SPECIAL INTEREST GRP GRAPH C1 NASA,MOFFETT FIELD,CA. NR 0 TC 2 Z9 2 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 0-8186-6627-7 J9 IEEE VISUAL PY 1994 BP 414 EP 418 PG 5 WC Computer Science, Software Engineering SC Computer Science GA BC60D UT WOS:A1994BC60D00065 ER PT B AU ARNAUD, SB WRONSKI, TJ KOROLKOV, VI DOTSENKO, R NAVIDI, M FUNG, P AF ARNAUD, SB WRONSKI, TJ KOROLKOV, VI DOTSENKO, R NAVIDI, M FUNG, P BE Norman, AW Bouillon, R Thomasset, M TI Vitamin D status in monkey candidates for space flight SO VITAMIN D: PLURIPOTENT STEROID HORMONE: STRUCTURAL STUDIES, MOLECULAR ENDOCRINOLOGY AND CLINICAL APPLICATIONS LA English DT Proceedings Paper CT 9th Workshop on Vitamin D CY MAY 28-JUN 02, 1994 CL ORLANDO, FL SP Chugai Pharm Co Ltd, Japan, Hoffmann La Roche Ltd, Switzerland, Hoffmann La Roche Inc, US, Inst Sci Roussel, France, Lab Leo SA, France, Leo Pharm Prod Ltd A S, Denmark, Novo Nordisk A S, Denmark, Procter & Gamble Pharm, US, Solvay Duphar BV, Netherlands, Sumitomo Pharm Co Ltd, Japan, Teijin Ltd, Japan, Westwood Squibb Pharm Res Inst, US C1 NASA,AMES RES CTR,DIV LIFE SCI,MOFFETT FIELD,CA 94035. NR 0 TC 2 Z9 2 U1 0 U2 0 PU WALTER DE GRUYTER PI BERLIN 30 PA GENTHINER STRASSE 13, W-1000 BERLIN 30, GERMANY BN 3-11-014157-4 PY 1994 BP 785 EP 786 PG 2 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA BD64B UT WOS:A1994BD64B00250 ER PT B AU CHAO, TH LAU, B MICELI, WJ AF CHAO, TH LAU, B MICELI, WJ BE Szu, HH TI OPTICAL IMPLEMENTATION OF IMAGE RESPRESENTATION USING MATCHING PURSUIT SO WAVELET APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet applications CY APR 05-08, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 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 0-8194-1546-4 J9 P SOC PHOTO-OPT INS PY 1994 VL 2242 BP 382 EP 388 DI 10.1117/12.170096 PG 7 WC Optics; Physics, Mathematical SC Optics; Physics GA BA44Y UT WOS:A1994BA44Y00034 ER PT B AU LEMOIGNE, J AF LEMOIGNE, J BE Szu, HH TI PARALLEL REGISTRATION OF MULTISENSOR REMOTELY-SENSED IMAGERY USING WAVELET COEFFICIENTS SO WAVELET APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet applications CY APR 05-08, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,GODDARD SPACE FLIGHT CTR,INFORMAT SCI & TECHNOL OFF,GREENBELT,MD 20771. NR 0 TC 17 Z9 17 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1546-4 J9 P SOC PHOTO-OPT INS PY 1994 VL 2242 BP 432 EP 443 DI 10.1117/12.170045 PG 12 WC Optics; Physics, Mathematical SC Optics; Physics GA BA44Y UT WOS:A1994BA44Y00039 ER PT B AU KIANG, RK KYLE, HL TELFER, BA SZU, HH AF KIANG, RK KYLE, HL TELFER, BA SZU, HH BE Szu, HH TI ANALYSES OF LONG-TERM SOLAR IRRADIANCE DATA WITH WAVELET TRANSFORMS SO WAVELET APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet applications CY APR 05-08, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,GODDARD SPACE FLIGHT CTR,EARTH SCI DATA OPERAT FACIL,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 0-8194-1546-4 J9 P SOC PHOTO-OPT INS PY 1994 VL 2242 BP 454 EP 462 DI 10.1117/12.170047 PG 9 WC Optics; Physics, Mathematical SC Optics; Physics GA BA44Y UT WOS:A1994BA44Y00041 ER PT B AU SCARGLE, JD AF SCARGLE, JD BE Szu, HH TI DETECTION AND MODELING OF CHAOTIC DYNAMICS USING WAVELET TECHNIQUES SO WAVELET APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet applications CY APR 05-08, 1994 CL ORLANDO, FL SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,AMES RES CTR,DIV SPACE SCI,THEORET STUDIES BRANCH,MOFFETT FIELD,CA 94035. 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 0-8194-1546-4 J9 P SOC PHOTO-OPT INS PY 1994 VL 2242 BP 463 EP 471 DI 10.1117/12.170048 PG 9 WC Optics; Physics, Mathematical SC Optics; Physics GA BA44Y UT WOS:A1994BA44Y00042 ER PT B AU SHELTON, RO HULTBERG, S LINDBLAD, T AF SHELTON, RO HULTBERG, S LINDBLAD, T GP INT NEURAL NETWORK SOC TI A NEURAL-NETWORK VME-MODULE FOR RECOGNIZING AC CURRENT DEMAND SIGNATURES IN-SPACE SHUTTLE TELEMETRY DATA SO WORLD CONGRESS ON NEURAL NETWORKS-SAN DIEGO - 1994 INTERNATIONAL NEURAL NETWORK SOCIETY ANNUAL MEETING, VOL 2 LA English DT Proceedings Paper CT 1994 International-Neural-Network-Society Annual Meeting - World Congress on Neural Networks-San Diego CY JUN 05-09, 1994 CL SAN DIEGO, CA SP INT NEURAL NETWORK SOC C1 NASA,LYNDON B JOHNSON SPACE CTR,SFTWARE TECHNOL BRANCH FT4,DIV INFORMAT TECHNOL,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LAWRENCE ERLBAUM ASSOC PUBL PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430 BN 0-8058-1745-X PY 1994 BP B631 EP B640 PG 10 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Mathematics, Applied; Neurosciences SC Automation & Control Systems; Computer Science; Mathematics; Neurosciences & Neurology GA BB69E UT WOS:A1994BB69E00105 ER PT B AU BARHEN, J FIJANY, A TOOMARIAN, N AF BARHEN, J FIJANY, A TOOMARIAN, N GP INT NEURAL NETWORK SOC TI GLOBALLY OPTIMAL NEURAL LEARNING SO WORLD CONGRESS ON NEURAL NETWORKS-SAN DIEGO, - 1994 INTERNATIONAL NEURAL NETWORK SOCIETY ANNUAL MEETING, VOL 3 LA English DT Proceedings Paper CT 1994 International-Neural-Network-Society Annual Meeting - World Congress on Neural Networks-San Diego CY JUN 05-09, 1994 CL SAN DIEGO, CA SP INT NEURAL NETWORK SOC C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LAWRENCE ERLBAUM ASSOC PUBL PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430 BN 0-8058-1745-X PY 1994 BP C370 EP C375 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BB69F UT WOS:A1994BB69F00058 ER PT B AU TROUDET, T MERRILL, W AF TROUDET, T MERRILL, W GP INT NEURAL NETWORK SOC TI A NOVEL-APPROACH TO NOISE-FILTERING BASED ON A GAIN-SCHEDULING NEURAL-NETWORK ARCHITECTURE SO WORLD CONGRESS ON NEURAL NETWORKS-SAN DIEGO, - 1994 INTERNATIONAL NEURAL NETWORK SOCIETY ANNUAL MEETING, VOL 3 LA English DT Proceedings Paper CT 1994 International-Neural-Network-Society Annual Meeting - World Congress on Neural Networks-San Diego CY JUN 05-09, 1994 CL SAN DIEGO, CA SP INT NEURAL NETWORK SOC C1 NASA,LEWIS RES CTR,ADV CONTROL TECHNOL BRANCH,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LAWRENCE ERLBAUM ASSOC PUBL PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430 BN 0-8058-1745-X PY 1994 BP C38 EP C45 PG 8 WC Computer Science, Artificial Intelligence SC Computer Science GA BB69F UT WOS:A1994BB69F00006 ER PT B AU HOOVER, RB WALKER, ABC FINESCHI, S BAKER, PC ZUKIC, M KIM, JM AF HOOVER, RB WALKER, ABC FINESCHI, S BAKER, PC ZUKIC, M KIM, JM BE Fineschi, S TI FABRICATION AND TEST OF A WIDE-FIELD H-LYMAN-ALPHA CORONAGRAPH POLARIMETER SO X-RAY AND ULTRAVIOLET POLARIMETRY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-ray and Ultraviolet Polarimetry CY JUL 15-16, 1993 CL SAN DIEGO, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1259-7 J9 P SOC PHOTO-OPT INS PY 1994 VL 2010 BP 104 EP 116 DI 10.1117/12.168570 PG 13 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BZ91D UT WOS:A1994BZ91D00012 ER PT B AU AUSTIN, RA MINAMITANI, T RAMSEY, BD AF AUSTIN, RA MINAMITANI, T RAMSEY, BD BE Fineschi, S TI DEVELOPMENT OF A HARD X-RAY-IMAGING POLARIMETER SO X-RAY AND ULTRAVIOLET POLARIMETRY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-ray and Ultraviolet Polarimetry CY JUL 15-16, 1993 CL SAN DIEGO, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812. 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 0-8194-1259-7 J9 P SOC PHOTO-OPT INS PY 1994 VL 2010 BP 118 EP 125 DI 10.1117/12.168571 PG 8 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BZ91D UT WOS:A1994BZ91D00013 ER PT B AU WEISSKOPF, MC ELSNER, RF JOY, MK ODELL, SL RAMSEY, BD GARMIRE, GP MESZAROS, P SUNYAEV, R AF WEISSKOPF, MC ELSNER, RF JOY, MK ODELL, SL RAMSEY, BD GARMIRE, GP MESZAROS, P SUNYAEV, R BE Fineschi, S TI A QUICK, CHEAP, AND BEAUTIFUL X-RAY POLARIMETER SO X-RAY AND ULTRAVIOLET SPECTROSCOPY AND POLARIMETRY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-ray and Ultraviolet Spectroscopy and Polarimetry CY JUL 28-29, 1994 CL SAN DIEGO, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS DE X-RAY ASTRONOMY; X-RAY POLARIMETERS C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812. NR 0 TC 3 Z9 3 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-1607-X J9 P SOC PHOTO-OPT INS PY 1994 VL 2283 BP 70 EP 74 DI 10.1117/12.193205 PG 5 WC Astronomy & Astrophysics; Remote Sensing; Spectroscopy SC Astronomy & Astrophysics; Remote Sensing; Spectroscopy GA BB88L UT WOS:A1994BB88L00008 ER PT B AU DUTTA, PK JAKUPCA, M SALVATI, L REDDY, KSN ANSARI, RR AF DUTTA, PK JAKUPCA, M SALVATI, L REDDY, KSN ANSARI, RR BE Weitkamp, J Karge, HG Pfeifer, H Holderich, W TI REVERSE MICELLE BASED SYNTHESIS OF MICROPOROUS MATERIALS IN HYDROCARBON SOLVENTS SO ZEOLITES AND RELATED MICROPOROUS MATERIALS: STATE OF THE ART 1994 SE STUDIES IN SURFACE SCIENCE AND CATALYSIS LA English DT Article; Proceedings Paper CT 10th International Zeolite Conference CY JUL 17-22, 1994 CL GARMISCH PARTENKIR, GERMANY ID TEMPERATURE SYNTHESIS; MOLECULAR-SIEVES; ZEOLITE; MICROEMULSIONS AB This paper discusses the synthesis of zincophosphate microporous materials from reactants enclosed in reverse micelles in a hydrocarbon medium. Crystals with sodalite morphology are formed in the case of these fast nucleating zincophosphates. In the case of aluminosilicates, gravitational forces lead to settling of an amorphous aluminosilicate solid, and crystals can be formed only from the settled phase. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP DUTTA, PK (reprint author), OHIO STATE UNIV,DEPT CHEM,120 W 18TH AVE,COLUMBUS,OH 43210, USA. NR 19 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE PUBL B V PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-81847-2 J9 STUD SURF SCI CATAL PY 1994 VL 84 BP 235 EP 242 PN A-C PG 8 WC Chemistry, Physical SC Chemistry GA BD02E UT WOS:A1994BD02E00029 ER PT J AU BAUSCHLICHER, CW LANGHOFF, SR PARTRIDGE, H AF BAUSCHLICHER, CW LANGHOFF, SR PARTRIDGE, H TI THEORETICAL-STUDY OF THE ELECTRONIC STATES OF MGC SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CORE POLARIZATION POTENTIALS; MOLECULAR WAVE-FUNCTIONS; GAUSSIAN-BASIS SETS; ANO BASIS-SETS; ABINITIO CALCULATIONS; ROW ATOMS; 1ST-ROW; ALKALI AB The singlet, triplet, and quintet states of MgC below about 30000 cm(-1) are studied theoretically to facilitate spectroscopic studies of this molecule. The B (3) Sigma(-)-X(3) Sigma(-) band system in the visible appears to be the best transition to characterize the X(3) Sigma(-) ground state. Our best estimate for the bond length of the X(3) Sigma(-) state of MgC is 2.071 +/- 0.002 Angstrom A, which includes an estimate of the important core-valence correlation effects using the core polarization potential method. The MgC+ molecule is calculated to have a (4) Sigma(-) ground state and a low-lying (II)-I-2 excited state. The adiabatic ionization potential of MgC is computed to be 7.74 eV. RP BAUSCHLICHER, CW (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 21 TC 25 Z9 25 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD DEC 31 PY 1993 VL 216 IS 3-6 BP 341 EP 347 DI 10.1016/0009-2614(93)90106-B PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA MP572 UT WOS:A1993MP57200017 ER PT J AU MIELKE, SL LYNCH, GC TRUHLAR, DG SCHWENKE, DW AF MIELKE, SL LYNCH, GC TRUHLAR, DG SCHWENKE, DW TI A SEPARABLE ROTATION APPROXIMATION FOR THE CALCULATION OF CHEMICAL-REACTION RATES SO CHEMICAL PHYSICS LETTERS LA English DT Article ID RATE CONSTANTS; SCATTERING; STATES AB We present a simple, yet remarkably accurate, approximate formula for the calculation of cumulative reaction probabilities and chemical reaction rates based on a separable-rotation approximation. The method allows a calculation of the full rate constant based on results for a single value of the total angular momentum J, and a criterion for selecting an appropriate value of J is provided. The method is tested for the D + H-2 reaction by new accurate quantal calculations of the cumulative reaction probability and by comparisons employing previous accurate quantal calculations of rate constants. The rate constants predicted from results with a single value of J agree with full calculations to within 5% for reaction rates up to 1500 K. C1 UNIV MINNESOTA,INST SUPERCOMP,MINNEAPOLIS,MN 55455. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP MIELKE, SL (reprint author), UNIV MINNESOTA,DEPT CHEM,CHEM PHYS PROGRAM,MINNEAPOLIS,MN 55455, 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 30 TC 40 Z9 40 U1 0 U2 0 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 31 PY 1993 VL 216 IS 3-6 BP 441 EP 446 DI 10.1016/0009-2614(93)90124-J PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA MP572 UT WOS:A1993MP57200035 ER PT J AU VELUSAMY, K GARG, VK AF VELUSAMY, K GARG, VK TI ENTRANCE FLOW IN ELLIPTIC-DUCTS SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE ENTRANCE FLOW; ELLIPTIC DUCT ID HEAT AB A control volume-based solution of the complete set of Navier Stokes equations for the laminar, three-dimensional developing flow in elliptical cross-section ducts is described. Numerical results for velocity and pressure development, pressure defect and entrance lengths are presented for a wide range of aspect ratios from 0.1 to 0.999. The present results match very well with earlier numerical solutions for developing flow in a circular duct and the fully developed flow in elliptical ducts. A comparison with earlier numerical and experimental data for developing flow in elliptical ducts is also satisfactory for pressure development but not so good for the velocity profiles. The relative growth rate of boundary layer thickness along the major axis is slower than that along the minor axis which is contrary to the assumption used in earlier numerical analyses. The present results show no transverse recirculation contrary to the speculation based on earlier experimental data. The ratio of entry length in an elliptical duct to that in a circular duct with radius equal to the semi-major axis of the elliptical duct is nearly equal to the aspect ratio of the duct. In conformity with the previous work, the present results find the total pressure defect to be independent of the aspect ratio, with a value of 1.234. C1 NASA,LEWIS RES CTR,DIV INTERNAL FLUID MECH,CLEVELAND,OH 44135. RP VELUSAMY, K (reprint author), INDIRA GANDHI CTR ATOM RES,THERMAL HYDRAUL SECT,KALPAKKAM 603102,INDIA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD DEC 30 PY 1993 VL 17 IS 12 BP 1079 EP 1096 DI 10.1002/fld.1650171205 PG 18 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA MK392 UT WOS:A1993MK39200004 ER PT J AU KHAKOO, MA JAYAWEERA, T WANG, S TRAJMAR, S AF KHAKOO, MA JAYAWEERA, T WANG, S TRAJMAR, S TI DIFFERENTIAL ELECTRON-SCATTERING FROM ACETYLENE ELASTIC-SCATTERING AND VIBRATIONAL-EXCITATION SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID CROSS-SECTIONS; C2H2; REGION AB Absolute differential cross sections for elastic scattering of electrons from acetylene are reported. The relative flow method was applied to normalize these cross sections, using helium as a standard. The measurements were made at the incident electron energies of 5 eV, 10 eV, 15 eV, 20 eV, 30 eV, 50 eV and 100 eV for electron scattering angles in the range of 10 degrees to 125 degrees. In addition, we report differential cross sections for excitation of the upsilon(1)/upsilon(3) (unresolved); upsilon(2), upsilon(4)/upsilon(5) (unresolved) and upsilon(4) + upsilon(5) vibrational modes of acetylene at 5 eV and 10 eV incident electron energies for scattering angles in the range of 20 degrees to 120 degrees. From these results integral cross sections are derived and the present results are compared with other available experimental and theoretical cross sections. C1 OBERLIN COLL,DEPT PHYS,OBERLIN,OH 44074. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP KHAKOO, MA (reprint author), CALIF STATE UNIV FULLERTON,DEPT PHYS,FULLERTON,CA 92634, USA. NR 27 TC 29 Z9 29 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD DEC 28 PY 1993 VL 26 IS 24 BP 4845 EP 4860 DI 10.1088/0953-4075/26/24/016 PG 16 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA MQ320 UT WOS:A1993MQ32000016 ER PT J AU NASH, DB SALISBURY, JW CONEL, JE LUCEY, PG CHRISTENSEN, PR AF NASH, DB SALISBURY, JW CONEL, JE LUCEY, PG CHRISTENSEN, PR TI EVALUATION OF INFRARED-EMISSION SPECTROSCOPY FOR MAPPING THE MOONS SURFACE-COMPOSITION FROM LUNAR ORBIT SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID PARTICULATE PLANETARY SURFACES; REFLECTANCE SPECTRA; THERMAL EMISSION; MINERALS; MODEL; BANDS AB Infrared thermal emission spectroscopy is evaluated for its possible application to compositional mapping of the Moon's surface from lunar orbit. Principles of the mid-IR (similar to 4-25 mu m) technique, previous lunar ground-based observations, and laboratory studies of Moon samples are reviewed and summarized. A lunar thermal emission spectrometer experiment is described, patterned after a similar instrument on the Mars Observer spacecraft. Thermal emission spectrometry from a polar-orbiting lunar spacecraft could provide a valuable mapping tool to aid in exploration for lunar resources and help provide understanding of the origin of the Moon and history of lunar surface processes. C1 ARIZONA STATE UNIV,DEPT GEOL,TEMPE,AZ 85287. JET PROP LAB,PASADENA,CA 91109. JOHNS HOPKINS UNIV,DEPT EARTH & PLANETARY SCI,BALTIMORE,MD 21218. UNIV HAWAII,HONOLULU,HI 96822. RP NASH, DB (reprint author), SAN JUAN CAPISTRANO RES INST,31872 CAMINO CAPISTRANO,SAN JUAN CAPISTRANO,CA 92675, USA. NR 75 TC 28 Z9 28 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-PLANET JI J. Geophys. Res.-Planets PD DEC 25 PY 1993 VL 98 IS E12 BP 23535 EP 23552 DI 10.1029/93JE02604 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA MQ051 UT WOS:A1993MQ05100002 ER PT J AU LEE, TJ AF LEE, TJ TI A COUPLED-CLUSTER STUDY OF HNO2 AND FNO2 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GAUSSIAN-BASIS SETS; MOLECULAR CALCULATIONS; ATOMS; CONTRACTION; ABINITIO; ISOMERS; SPECTRA; CL2O2 AB The CCSD(T) method has been used with a TZ2P basis set to predict the structure, dipole moment, and vibrational spectrum of HNO2. The ab initio results should be of high accuracy based on comparison to the related compounds FNO2 and ClNO2. The DELTAH(f)298 for HNO2 (-10.3 +/- 1.0 kcal/mol) is determined from an isodesmic reaction involving ClNO, HNO, and ClNO2, and also by comparison to trans-HONO. Using this data, a revised DELTAH(f)298 for FNO2 (-22.1 +/- 1.0 kcal/mol) is determined, which is more accurate than the currently accepted experimental estimate. HNO2 is almost-equal-to 9 kcal/mol less stable than trans-HONO, suggesting that it is only of minor importance in atmospheric chemistry. RP LEE, TJ (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RI Lee, Timothy/K-2838-2012 NR 24 TC 13 Z9 13 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 DEC 24 PY 1993 VL 216 IS 1-2 BP 194 EP 199 DI 10.1016/0009-2614(93)E1232-6 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA MM632 UT WOS:A1993MM63200031 ER PT J AU RAMPINO, MR SELF, S AF RAMPINO, MR SELF, S TI BOTTLENECK IN HUMAN-EVOLUTION AND THE TOBA ERUPTION SO SCIENCE LA English DT Letter ID WINTER C1 NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025. UNIV HAWAII MANOA,SCH OCEAN & EARTH SCI & TECHNOL,DEPT GEOL & GEOPHYS,HONOLULU,HI 96822. RP RAMPINO, MR (reprint author), NYU,DEPT EARTH SYST SCI,NEW YORK,NY 10003, USA. NR 4 TC 26 Z9 27 U1 11 U2 41 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 24 PY 1993 VL 262 IS 5142 BP 1955 EP 1955 DI 10.1126/science.8266085 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MN108 UT WOS:A1993MN10800005 PM 8266085 ER PT J AU GOSLING, JT BAME, SJ MCCOMAS, DJ PHILLIPS, JL PIZZO, VJ GOLDSTEIN, BE NEUGEBAUER, M AF GOSLING, JT BAME, SJ MCCOMAS, DJ PHILLIPS, JL PIZZO, VJ GOLDSTEIN, BE NEUGEBAUER, M TI LATITUDINAL VARIATION OF SOLAR-WIND COROTATING STREAM INTERACTION REGIONS - ULYSSES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PIONEER-10 AB Ulysses' initial transit to high heliographic latitudes at a heliocentric distance of approximately 5 AU has revealed systematic effects in the latitudinal evolution of corotating interaction regions (CIRs). At a latitude corresponding roughly to, but slightly less than, the inferred tilt of the coronal streamer belt and embedded heliospheric current sheet, the strong forward shocks commonly associated with CIRs at lower latitudes disappeared almost entirely; however, the reverse shocks associated with these CIRs persisted to latitudes approximately 10-degrees above the streamer belt. Systematic meridional flow deflections observed in association with the forward and reverse waves bounding the CIRs demonstrate that the above effect is the result of the fact that the forward waves propagate to lower latitudes and the reverse waves to higher latitudes with increasing heliocentric distance. These observational results are in excellent agreement with the predictions of a three-dimensional model of corotating solar wind flows that originate in a tilted dipole geometry back at the Sun, C1 SAN JUAN INST,SAN JUAN,CA. NOAA,SEL,BOULDER,CO 80303. JET PROP LAB,PASADENA,CA 91109. RP GOSLING, JT (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. NR 9 TC 122 Z9 123 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 23 PY 1993 VL 20 IS 24 BP 2789 EP 2792 DI 10.1029/93GL03116 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MQ173 UT WOS:A1993MQ17300002 ER PT J AU SCHOEBERL, MR STOLARSKI, RS DOUGLASS, AR NEWMAN, PA LAIT, LR WATERS, JW FROIDEVAUX, L READY, WG AF SCHOEBERL, MR STOLARSKI, RS DOUGLASS, AR NEWMAN, PA LAIT, LR WATERS, JW FROIDEVAUX, L READY, WG TI MLS CLO OBSERVATIONS AND ARCTIC POLAR VORTEX TEMPERATURES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CHEMICAL-COMPOSITION; STRATOSPHERE; LATITUDE; WINTER AB Analysis of UARS MLS observations in early January 1992 shows a clear relationship between predicted polar stratospheric cloud formation along the back trajectory and elevated ClO amounts. These findings are in good agreement with aircraft observations. The MLS observed variation of ClO amounts within the vortex also fits the pattern of ClO change as a result of air parcel solar exposure and nitric acid photolysis. Outside the polar vortex, the occasional highly elevated ClO appear statistically consistent with MLS measurement noise. C1 JET PROP LAB,PASADENA,CA 91109. RP SCHOEBERL, MR (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 916,GREENBELT,MD 20771, USA. RI Newman, Paul/D-6208-2012; Douglass, Anne/D-4655-2012; Stolarski, Richard/B-8499-2013 OI Newman, Paul/0000-0003-1139-2508; Stolarski, Richard/0000-0001-8722-4012 NR 14 TC 18 Z9 18 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 23 PY 1993 VL 20 IS 24 BP 2861 EP 2864 DI 10.1029/93GL02954 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MQ173 UT WOS:A1993MQ17300020 ER PT J AU DICKEY, JO MARCUS, SL JOHNS, CM HIDE, R THOMPSON, SR AF DICKEY, JO MARCUS, SL JOHNS, CM HIDE, R THOMPSON, SR TI THE OCEANIC CONTRIBUTION TO THE EARTHS SEASONAL ANGULAR-MOMENTUM BUDGET SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; TRANSPORT AB Seasonal variations in the speed of the Earth's rotation manifest themselves as fluctuations in the length of the day (LOD) with an amplitude of about 1000 microseconds (mus). We know from previous work that at least 95% of these variations can be accounted for in terms of angular momentum exchanged between the atmosphere and the solid Earth. Here we examine the respective contributions of the Antarctic Circumpolar Current (ACC) and the global oceans to the Earth's seasonal angular momentum budget, using in situ data from the Drake Passage and results from both the oceanic regional model (Fine Resolution Antarctic Model-FRAM) of Webb et al. [1991] and the global oceanic model of Maier-Reimer et al. [1993] as analyzed by Brosche et al. [1990]. The estimated annual contribution of the ACC (2-4 mus) is much smaller than the total variation in the oceanic models or the existing LOD-AAM residual (both approximately 15-20 mus). The estimated semi-annual ACC contribution (3-8 mus) is offset by counter-currents further north in both oceanic models, which exhibit larger semi-annual variations in planetary angular momentum. Further refinements in the Earth's seasonal angular momentum budget, therefore, will require the full (planetary plus relative) contribution of the global oceans in addition to that of the ACC. C1 NERC,CLARENDON LAB,OCEANOG UNIT,OXFORD OX1 3PU,ENGLAND. NERC,INST OCEANOG SCI,DEACON LAB,WORMLEY GU8 5UB,SURREY,ENGLAND. RP DICKEY, JO (reprint author), JET PROP LAB,SPACE GEODET SCI & APPLICAT GRP,PASADENA,CA 91109, USA. OI Marcus, Steven/0000-0002-5763-6961 NR 13 TC 29 Z9 30 U1 1 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 23 PY 1993 VL 20 IS 24 BP 2953 EP 2956 DI 10.1029/93GL03186 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MQ173 UT WOS:A1993MQ17300043 ER PT J AU SQUYRES, SW JANES, DM SCHUBERT, G BINDSCHADLER, DL MOERSCH, JE TURCOTTE, DL STOFAN, ER AF SQUYRES, SW JANES, DM SCHUBERT, G BINDSCHADLER, DL MOERSCH, JE TURCOTTE, DL STOFAN, ER TI THE SPATIAL-DISTRIBUTION OF CORONAE AND RELATED FEATURES ON VENUS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MANTLE; CONVECTION; EVOLUTION; MODELS AB Coronae are large quasi-circular geologic features that are common on Venus. They appear to be the surface tectonic and volcanic expressions of mantle diapirs that have impinged on the underside of the venusian lithosphere. We have investigated the spatial distribution of 335 coronae and related features identified in Magellan radar data. It is more clustered than a Poisson distribution, with a statistical certainty of more than 99%. It is dominated by a single large cluster centered near the equator at about 245-degrees longitude. The features axe preferentially found at elevation and geoid values close to the planetary mean, with a paucity at both the highest and lowest levels of topography and geoid. Some coronae appear aligned in quasi-linear chains. We attribute the clustering of coronae and related features to preferential formation of these features above regions of broad-scale mantle upwelling, and suggest that a major mantle upwelling underlies the one large duster. We suggest that coronae axe rare at the lowest elevations because these may be regions of mantle downwelling. The shortage of coronae at the highest elevations may result both from obscuration by other intense tectonism there and from suppression there of their formation by an unusually thick crust. Corona chains may be produced by enhanced passive mantle uplift below failed or incipient rifts. C1 UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90024. CORNELL UNIV,DEPT GEOL SCI,ITHACA,NY 14853. JET PROP LAB,PASADENA,CA 91109. RP SQUYRES, SW (reprint author), CORNELL UNIV,CTR RADIOPHYS & SPACE RES,ITHACA,NY 14853, USA. RI Moersch, Jeffrey/F-7189-2010 NR 17 TC 11 Z9 11 U1 0 U2 3 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 23 PY 1993 VL 20 IS 24 BP 2965 EP 2968 DI 10.1029/93GL00866 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MQ173 UT WOS:A1993MQ17300046 ER PT J AU TOTH, RA AF TOTH, RA TI LINE STRENGTHS (900-3600 CM(-1)), SELF-BROADENED LINEWIDTHS, AND FREQUENCY-SHIFTS (1800-2360 CM(-1)) OF N2O SO APPLIED OPTICS LA English DT Article ID TUNABLE DIODE-LASER; REGION; BAND; SPECTROSCOPY; INTENSITIES; CM-1 AB Self-broadened linewidths and pressure-induced frequency shifts of N2O were measured from spectra obtained at high spectral resolution in the 1800-2630 cm(-1) region. From measurements of 136 Lines, the average pressure-shift coefficient was found to be -0.0015 +/- 0.0006 cm(-1)/atm. The shift coefficients were found to have a weak J dependence, in which the magnitude of the coefficients increases with increasing values of J. Line-strength measurements were derived from spectra obtained at low sample pressures, and these data were analyzed to determine vibrational band strengths, rotationless dipole-moment matrix elements, and F factor coefficients for several bands in the 900-3600 cm(-1) region. Measurements of over 15,000 selected vibration-rotation transitions, including eight N2O isotopic species, were used in the various analyses. RP TOTH, RA (reprint author), CALTECH, JET PROP LAB, MS 183-301, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 23 TC 65 Z9 64 U1 0 U2 10 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 20 PY 1993 VL 32 IS 36 BP 7326 EP 7365 PG 40 WC Optics SC Optics GA MU150 UT WOS:A1993MU15000002 PM 20861949 ER PT J AU MOBLEY, CD GENTILI, B GORDON, HR JIN, ZH KATTAWAR, GW MOREL, A REINERSMAN, P STAMNES, K STAVN, RH AF MOBLEY, CD GENTILI, B GORDON, HR JIN, ZH KATTAWAR, GW MOREL, A REINERSMAN, P STAMNES, K STAVN, RH TI COMPARISON OF NUMERICAL-MODELS FOR COMPUTING UNDERWATER LIGHT FIELDS SO APPLIED OPTICS LA English DT Article ID DISCRETE-ORDINATE-METHOD; ANISOTROPICALLY SCATTERING ATMOSPHERES; RADIATIVE-TRANSFER CALCULATIONS; DIFFUSE REFLECTANCE; OPTICAL-PROPERTIES; NATURAL-WATERS; ABSORPTION-COEFFICIENT; RADIANCE DISTRIBUTION; MULTIPLE-SCATTERING; RAMAN-SCATTERING AB Seven models for computing underwater radiances and irradiances by numerical solution of the radiative transfer equation are compared. The models are applied to the solution of several problems drawn from optical oceanography. The problems include highly absorbing and highly scattering waters, scattering by molecules and by particulates, stratified water, atmospheric effects, surface-wave effects, bottom effects, and Raman scattering. The models provide consistent output, with errors (resulting from Monte Carlo statistical fluctuations) in computed irradiances that are seldom larger, and are usually smaller, than the experimental errors made in measuring irradiances when using current oceanographic instrumentation. Computed radiances display somewhat larger errors. C1 UNIV PIERRE & MARIE CURIE, PHYS & CHIM MARINES LAB, F-06230 VILLEFRANCHE SUR MER, FRANCE. UNIV MIAMI, DEPT PHYS, CORAL GABLES, FL 33124 USA. UNIV ALASKA, INST GEOPHYS, FAIRBANKS, AK 99701 USA. TEXAS A&M UNIV, DEPT PHYS, COLL STN, TX 77843 USA. UNIV S FLORIDA, DEPT MARINE SCI, ST PETERSBURG, FL 33701 USA. UNIV N CAROLINA, DEPT BIOL, GREENSBORO, NC 27412 USA. RP MOBLEY, CD (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, MAIL STOP 300-323, PASADENA, CA 91109 USA. NR 62 TC 264 Z9 274 U1 1 U2 17 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD DEC 20 PY 1993 VL 32 IS 36 BP 7484 EP 7504 PG 21 WC Optics SC Optics GA MU150 UT WOS:A1993MU15000022 PM 20861969 ER PT J AU KHAN, MA KUZNIA, JN OLSON, DT GEORGE, T PIKE, WT AF KHAN, MA KUZNIA, JN OLSON, DT GEORGE, T PIKE, WT TI GAN/ALN DIGITAL ALLOY SHORT-PERIOD SUPERLATTICES BY SWITCHED ATOMIC LAYER METALORGANIC CHEMICAL-VAPOR-DEPOSITION SO APPLIED PHYSICS LETTERS LA English DT Article ID STIMULATED-EMISSION; ROOM-TEMPERATURE; GAN; SAPPHIRE; ULTRAVIOLET; EPITAXY; GROWTH AB In this letter we report the fabrication of GaN/AlN short-period superlattices using switched atomic layer epitaxy. Superlattice structures with GaN well thicknesses ranging from 2.6 to 20.8 angstrom (with AlN barrier thicknesses of 2.5, 7.5, and 15 angstrom) were deposited over basal plane sapphire and characterized for their structure, crystallinity, and optical properties. Cross-sectional transmission electron micrographs indicate GaN/AlN interfaces and the superlattice surfaces are atomically smooth. The structures exhibit strong room temperature photoluminescence and a sharp absorption edge indicating a high optical quality. C1 JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109. RP KHAN, MA (reprint author), ASA OPT INC,2950 NE 84TH LANE,BLAINE,MN 55434, USA. NR 15 TC 62 Z9 65 U1 0 U2 10 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 20 PY 1993 VL 63 IS 25 BP 3470 EP 3472 DI 10.1063/1.110123 PG 3 WC Physics, Applied SC Physics GA MM448 UT WOS:A1993MM44800025 ER PT J AU PARK, JS LIN, TL JONES, EW GUNAPALA, SD SOLI, GA WILSON, BA AF PARK, JS LIN, TL JONES, EW GUNAPALA, SD SOLI, GA WILSON, BA TI PROTON IRRADIATION EFFECTS ON STRAINED SI1-XGEX/SI HETEROSTRUCTURES SO APPLIED PHYSICS LETTERS LA English DT Article AB Proton irradiation effects on strained Si1-xGex/Si heterostructures have been studied. For the experiment, p+-Si1-xGex/p--Si heterojunction diodes were fabricated by molecular beam epitaxy (MBE) growth of strained p+-boron doped SiGe layers on p--Si(100) substrates. Due to the valence band discontinuity between SiGe and Si layers. and degenerate doping in the SiGe layer, the characteristics of these heterojunction diodes are similar to those of metal-semiconductor Schottky barrier diodes. The SiGe/Si heterojunction diodes are irradiated by 1 Mrad of protons at 1 and 8.5 MeV energies. The current-voltage (I-V) characteristics are measured as a function of temperature before and after irradiation. I-V characteristics show a decrease of the reverse bias leakage current after irradiation. The effective heterojunction barrier heights (PHI(b)) and Richardson constants (A**) are measured before and after irradiation using activation energy measurements. The measurements show an increase Of PHI(b) and A** after irradiation. The increase of the effective barrier height is attributed to reduction of free-holes in the SiGe layers due to proton induced displacement defects. The increase of effective barrier height suggests that the strain in the SiGe layers is conserved after 1 Mrad of proton irradiation. RP PARK, JS (reprint author), JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109, USA. NR 12 TC 2 Z9 2 U1 0 U2 0 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 20 PY 1993 VL 63 IS 25 BP 3497 EP 3499 DI 10.1063/1.110131 PG 3 WC Physics, Applied SC Physics GA MM448 UT WOS:A1993MM44800034 ER PT J AU MORRIS, SL WEYMANN, RJ DRESSLER, A MCCARTHY, PJ SMITH, BA TERRILE, RJ GIOVANELLI, R IRWIN, M AF MORRIS, SL WEYMANN, RJ DRESSLER, A MCCARTHY, PJ SMITH, BA TERRILE, RJ GIOVANELLI, R IRWIN, M TI THE ENVIRONMENT OF LYMAN-ALPHA ABSORBERS IN THE SIGHT LINE TOWARD 3C-273 SO ASTROPHYSICAL JOURNAL LA English DT Article DE INTERGALACTIC MEDIUM; QUASARS, ABSORPTION LINE; QUASARS, INDIVIDUAL (3C-273) ID DWARF GALAXIES; REDSHIFT SURVEY; VIRGO CLUSTER; SPECTRUM; CATALOG; SYSTEM; FOREST; CLOUDS AB We present new ground-based data following up on the Hubble Space Telescope discovery of low-redshift Lyalpha absorption in the sight line to the quasar 3C 273. Our goal is to investigate the relationship between the low column density absorbers and higher column density objects such as galaxies or H II regions. Narrow-band filter observations with a coronagraph show that there are no H II regions or other strong Halpha line-emitting ps within a 12 kpc radius of the line of sight to the quasar, at the velocities of three of the absorbers. Broad-band imaging in Gunn r shows that there are no dwarf galaxies at Virgo distances with absolute magnitude above MB almost-equal-to - 13.5 and within a radius of 40 kpc from the line of sight to the quasar. Finally, we present fiber spectroscopy of a complete sample of galaxies within a radius of 1-degrees, down to an apparent magnitude of B almost-equal-to 19. Analysis of this sample, combined with galaxies within 10 Mpc of the quasar line of sight taken from the literature, shows that the absorbers are definitely not distributed at random with respect to the galaxies, but also that the absorber-galaxy correlation function is not as strong as the galaxy-galaxy correlation function on large scales. We show that our data are consistent with the hypothesis that all galaxies more luminous than 0.1L* have effective cross sections [for association with absorbers whose neutral hydrogen column density (log N(HI)) is greater than 13.0] of between 0.5 and 1 Mpc. We also show a clear case of a Lyalpha absorber which has no galaxy brighter than M(B) = - 18 within a projected distance of 4.8 Mpc, and discuss the possibility that Lyalpha absorbers are destroyed in a rich galaxy environment. C1 CARNEGIE INST WASHINGTON,THE OBSERVATORIES,PASADENA,CA 91101. UNIV HAWAII,INST ASTRON,HONOLULU,HI 96822. JET PROP LAB,PASADENA,CA 91109. CORNELL UNIV,NATL ASTRON & IONOSPHERE CTR,ITHACA,NY 14853. CORNELL UNIV,DEPT ASTRON,ITHACA,NY 14853. ROYAL GREENWICH OBSERV,CAMBRIDGE CB3 0EZ,ENGLAND. RI Morris, Simon/G-7981-2011 OI Morris, Simon/0000-0003-4866-110X NR 39 TC 142 Z9 144 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 1993 VL 419 IS 2 BP 524 EP 540 DI 10.1086/173505 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML593 UT WOS:A1993ML59300010 ER PT J AU ORLANDINI, M BOLDT, E AF ORLANDINI, M BOLDT, E TI ON THE OBSERVABILITY OF MICROSECOND TEMPORAL STRUCTURE IN THE EMISSION FROM X-RAY BINARY PULSARS SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCRETION, ACCRETION DISKS; PULSARS, GENERAL; STARS, NEUTRON; X-RAYS, STARS ID MAGNETIZED NEUTRON STARS; INTERCHANGE INSTABILITY; ACCRETION; MODEL AB We discuss the possibility of detecting the microsecond granularity expected in the flux from wind-fed X-ray binary pulsars. This microsecond structure is predicted by the noisy accretion scenario; we derive the physical characteristics of such burst structure in the framework of this model. We investigate the temporal dispersion induced by the scattering of burst photons in their passage through the neutron star magnetosphere and conclude that microsecond structure could indeed be observable for energies less than the cyclotron energy. We show that the coincidence timing mode for the Proportional Counter Array on-board XTE can be used very effectively to statistically discriminate these microsecond bursts from accidental spurious detections. C1 NASA,GODDARD SPACE FLIGHT CTR,GSFC,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. RI Orlandini, Mauro/H-3114-2014 OI Orlandini, Mauro/0000-0003-0946-3151 NR 17 TC 2 Z9 2 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 1993 VL 419 IS 2 BP 776 EP 779 DI 10.1086/173529 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML593 UT WOS:A1993ML59300034 ER PT J AU RUFFERT, M CANNIZZO, JK KENYON, SJ AF RUFFERT, M CANNIZZO, JK KENYON, SJ TI THE SECONDARY OUTBURST MAXIMUM OF T-CORONAE BOREALIS - HYDRODYNAMIC SIMULATIONS OF THE BLOB AND ACCRETION DISK SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCRETION, ACCRETION DISKS; HYDRODYNAMICS; STARS, INDIVIDUAL (T-CORONAE BOREALIS) ID ACTIVE GALACTIC NUCLEI; MASSIVE BLACK-HOLE; MAIN-SEQUENCE STAR; WHITE-DWARF; SEMIDETACHED BINARIES; EVOLUTION; NOVAE; COLLISIONS; MODELS; ALPHA AB We continue the investigation of Cannizzo & Kenyon into the model proposed by Webbink to account for the eruptive behavior of the recurrent nova T CrB which occurred in 1946. In particular, we present three-dimensional hydrodynamical computations of the blob of material which is ejected from the mass-losing star in the Webbink model and find that, within several dynamical timescales, the blob should become smeared out by tidal forces and internal gas pressure into a disk-shaped body with roughly constant surface density (as projected onto the orbital plane). We then reexamine the spreading torus model employed by Cannizzo & Kenyon to account for the observed secondary maximum in the 1946 outburst using a one-dimensional accretion disk model within the context of the three-dimensional hydrodynamical results. The model presented by Cannizzo & Kenyon of an exponentially increasing viscosity parameter alpha(t) for the accretion disk is still viable, but the accretion disk flux during early times is much greater than before. In addition, during the time before peak accretion disk luminosity there are two outward-moving transition fronts-one associated with the transition between the low- and high-alpha regions of the disk, and a second associated with the interface between ionized and neutral disk material. These are roughly coincident with each other and are caused by the outward wave of increasing accretion disk viscosity which comes about when one takes a local growth rate for a dependent on the Keplerian frequency. We are able to reproduce the secondary maximum fairly well using 10(-5) and 3 for initial and final values of alpha, and a local growth timescale for alpha of 2/OMEGA. C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. RP RUFFERT, M (reprint author), MAX PLANCK INST ASTROPHYS,POSTFACH 1523,D-85740 GARCHING,GERMANY. OI Kenyon, Scott/0000-0003-0214-609X NR 22 TC 4 Z9 4 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 1993 VL 419 IS 2 BP 780 EP 792 DI 10.1086/173530 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML593 UT WOS:A1993ML59300035 ER PT J AU IMAMURA, JN MIDDLEDITCH, J SCARGLE, JD STEIMANCAMERON, TY WHITLOCK, LA WOLFF, MT WOOD, KS AF IMAMURA, JN MIDDLEDITCH, J SCARGLE, JD STEIMANCAMERON, TY WHITLOCK, LA WOLFF, MT WOOD, KS TI THE QUASI-PERIODIC OSCILLATIONS OF VV PUPPIS SO ASTROPHYSICAL JOURNAL LA English DT Article DE BINARIES, CLOSE; NOVAE, CATACLYSMIC VARIABLES; STARS, INDIVIDUAL (VV PUPPIS); STARS, OSCILLATIONS; WHITE DWARFS ID DRIVEN RADIATIVE SHOCKS; MAGNETIC WHITE-DWARFS; TIME-SERIES ANALYSIS; AM HERCULIS OBJECTS AB Four AM Her objects are known to exhibit low-amplitude, rapid quasi-periodic oscillations (QPOs) in their optical emission. Here, we present high-speed optical photometric observations of the QPO source VV Pup obtained during 1990 January. The observations were made in unfiltered light. We first confirm the results of Larsson (1989) that VV Pup is a strong source of QPOs and that the QPOs are confined to optical maximum showing that the QPOs are produced in or near the X-ray-producing shock formed as the accreting plasma merges onto the white dwarf. We then show that: (1) variations in the amplitudes of the QPOs over narrow bandwidths, deltanu approximately 0.1 Hz, around the peak of the QPOs, nu(QPO) approximately 0.6-0.7 Hz, are correlated. We also find a suggestion that the QPO powers at widely separated frequencies are also positively correlated. These results suggest that the QPOs are due to a broad-band process rather than to a narrow-band feature which wanders slowly in frequency space. (2) We isolate strong damped oscillations in several 81.92 s intervals. The pulse profiles are consistent with damped sinusoids. The strongest feature has an amplitude of several percent with frequency v approximately 0.64 Hz and quality Q approximately 21, or a coherence Of tau approximately 6.7. VV Pup is the third QPO source to show evidence of strong oscillations of moderate coherence. C1 UNIV OREGON,INST THEORET SCI,EUGENE,OR 97403. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. USRA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV CALIF SANTA CRUZ,LICK OBSERV,SANTA CRUZ,CA 95064. USN,RES LAB,WASHINGTON,DC 20375. RP IMAMURA, JN (reprint author), UNIV OREGON,DEPT PHYS,EUGENE,OR 97403, USA. NR 18 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 1993 VL 419 IS 2 BP 793 EP 802 DI 10.1086/173531 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML593 UT WOS:A1993ML59300036 ER PT J AU MACFARLANE, JJ WALDRON, WL CORCORAN, MF WOLFF, MJ WANG, P CASSINELLI, JP AF MACFARLANE, JJ WALDRON, WL CORCORAN, MF WOLFF, MJ WANG, P CASSINELLI, JP TI EFFECTS OF CORONAL AND SHOCK-PRODUCED X-RAYS ON THE IONIZATION DISTRIBUTION IN HOT STAR WINDS SO ASTROPHYSICAL JOURNAL LA English DT Article DE SHOCK WAVES; STARS, CORONAE; STARS, MASS LOSS; X-RAYS, STARS ID O-TYPE STARS; DRIVEN STELLAR WINDS; RESONANCE LINES; SUPER-GIANTS; ZETA-PUPPIS; SEI METHOD; MASS-LOSS; EMISSION; PROFILES; RECOMBINATION AB We investigate the effects of X-ray radiation on the ionization distribution in the wind of zeta Pup (O4 If). In particular, we have studied how the distribution of the ''superionization'' species 0 VI is affected by X-ray source characteristics. In our calculations, detailed statistical equilibrium and atomic physics models are used to ensure that critical processes such as photoionization out of excited states and Auger ionization are considered. For shock-produced X-ray sources, we show how the distribution of X-ray emission affects the O VI P Cygni profile and the resultant X-ray spectrum. For coronal sources, we examine the sensitivity of the X-ray spectrum and O VI profile to the mass-loss rate and attenuation by the overlying wind. Results are compared with UV data from Copernicus and X-ray spectral data from the Einstein Imaging Proportional Center and Broad-Band X-ray Telescope. We find that coronal models are not simultaneously consistent with both UV and X-ray data unless the mass-loss rate is less than or similar to 1 x 10(-6) M., yr-1, which is a factor of at least 3 to 5 lower than the values deduced from radio observations. Results from calculations using a mass-loss rate inferred from radio observations suggest that the X-ray source is distributed throughout the wind. In addition, calculations using a distributed X-ray source indicate that a significant X-ray flux must originate from regions close to the star (within 2 stellar radii) in order to produce an O VI P Cygni profile consistent with observations. C1 UNIV WISCONSIN,INST FUS TECHNOL,MADISON,WI 53706. NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. APPL RES CORP,LANDOVER,MD 20785. RP MACFARLANE, JJ (reprint author), UNIV WISCONSIN,DEPT ASTRON,MADISON,WI 53706, USA. NR 49 TC 44 Z9 44 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 1993 VL 419 IS 2 BP 813 EP 823 DI 10.1086/173533 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML593 UT WOS:A1993ML59300038 ER PT J AU FEKEL, FC BOPP, BW AF FEKEL, FC BOPP, BW TI OPTICAL SPECTROSCOPY OF THE DUSTY K5-V STAR HD-98800 SO ASTROPHYSICAL JOURNAL LA English DT Article DE CIRCUMSTELLAR MATTER; STARS, ACTIVITY; STARS, LATE-TYPE ID CHROMOSPHERICALLY ACTIVE STARS; X-RAY-EMISSION; T-TAURI STARS; DISCOVERY; LITHIUM; CATALOG; MATTER; SEARCH AB High-resolution CCD spectra of the red region of the dusty K5 V star HD 98800, which may contain a protoplanetary disk, have been obtained at Kitt Peak National Observatory. The spectra verify the dwarf spectral type and show rotationally broadened photospheric lines, Halpha emission, and a very strong Li i lambda6707 absorption line, all of which confirm the star as a very young object. The overall spectrum of HD 98800 closely resembles that of the young, chromospherically active, single BY Dra star HD 82558 (=LQ Hya). The measured Li I equivalent width of 0.39 angstrom implies an abundance log N(Li) = 2.2 and suggests an age < 10 Myr. HD 98800 should be photometrically variable with a probable rotation period of 5-10 days. The high level of chromospheric activity suggests HD 98800 may be detectable as an X-ray and radio source. C1 TENNESSEE STATE UNIV,CTR EXCELLENCE INFORMAT SYST,NASHVILLE,TN 37203. UNIV TOLEDO,RITTER OBSERV,TOLEDO,OH 43606. UNIV TOLEDO,DEPT PHYS & ASTRON,TOLEDO,OH 43606. RP FEKEL, FC (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,ES-52,HUNTSVILLE,AL 35812, USA. NR 36 TC 20 Z9 20 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 1993 VL 419 IS 2 BP L89 EP L92 DI 10.1086/187144 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML594 UT WOS:A1993ML59400012 ER PT J AU THORSETT, SE DEWEY, RJ AF THORSETT, SE DEWEY, RJ TI LIMITS ON PLANETS ORBITING MASSIVE STARS FROM RADIO PULSAR TIMING SO ASTROPHYSICAL JOURNAL LA English DT Article DE PLANETARY SYSTEMS; PULSARS, GENERAL; SUPERNOVAE, GENERAL ID BINARY PULSAR; PSR1829-10; EVOLUTION; MASSES; SYSTEM AB When a massive star collapses to a neutron star, rapidly losing over one-half its mass in a symmetric supernova explosion, any planets orbiting the star will be unbound. However, to explain the observed space velocity and binary fraction of radio pulsars, an asymmetric kick must be given to the neutron star at birth. Occasionally, this kick will prevent the resulting pulsar-planet system from unbinding. We estimate the survival probability of a Jupiter-type planet in an asymmetric supernova explosion and show that if a typical massive star has one such planet, then several known nonmillisecond pulsars should possess planetary companions in highly eccentric orbits. Conversely, if pulsar timing measurements fail to detect planets orbiting these pulsars, then the average number of such planets per star is less than about 0.5. C1 JET PROP LAB,PASADENA,CA 91109. RP THORSETT, SE (reprint author), CALTECH,OWENS VALLEY RADIO OBSERV 10524,PASADENA,CA 91125, USA. OI Thorsett, Stephen/0000-0002-2025-9613 NR 35 TC 12 Z9 12 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 1993 VL 419 IS 2 BP L65 EP L68 DI 10.1086/187138 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML594 UT WOS:A1993ML59400006 ER PT J AU RUSSELL, PB LIVINGSTON, JM DUTTON, EG PUESCHEL, RF REAGAN, JA DEFOOR, TE BOX, MA ALLEN, D PILEWSKIE, P HERMAN, BM KINNE, SA HOFMANN, DJ AF RUSSELL, PB LIVINGSTON, JM DUTTON, EG PUESCHEL, RF REAGAN, JA DEFOOR, TE BOX, MA ALLEN, D PILEWSKIE, P HERMAN, BM KINNE, SA HOFMANN, DJ TI PINATUBO AND PRE-PINATUBO OPTICAL-DEPTH SPECTRA - MAUNA-LOA MEASUREMENTS, COMPARISONS, INFERRED PARTICLE-SIZE DISTRIBUTIONS, RADIATIVE EFFECTS, AND RELATIONSHIP TO LIDAR DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EL-CHICHON; MT-PINATUBO; STRATOSPHERIC AEROSOL; ATMOSPHERIC TRANSMISSION; VOLCANIC-ERUPTION; CLOUD; EXTINCTION; OZONE; MODEL; MASS AB The Ames airborne tracking sunphotometer was operated at the National Oceanic and Atmospheric Administration (NOAA) Mauna Loa Observatory (MLO) in 1991 and 1992 along with the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) automated tracking sunphotometer and lidar. June 1991 measurements provided calibrations, optical-depth spectra, and intercomparisons under relatively clean conditions; later measurements provided spectra and comparisons for the Pinatubo cloud plus calibration checks. June 1991 results are similar to previous MLO springtime measurements, with midvisible particle optical depth tau(p)(lambda = 0.526 mum) at the near-background level of 0.012 +/- 0.006 and no significant wavelength dependence in the measured range (lambda = 0.38 to 1.06 mum). The arrival of the Pinatubo cloud in July 1991 increased midvisible particle optical depth by more than an order of magnitude and changed the spectral shape of tau(p)(lambda) to an approximate power law with an exponent of about -1.4. By early September 1991, the spectrum was broadly peaked near 0.5 mum, and by July 1992, it was peaked near 0.8 mum. Our optical-depth spectra include corrections for diffuse light which increase postvolcanic midvisible tau(p) values by 1 to 3% (i.e., 0.0015 to 0.0023). NOAA- and Ames Research Center (ARC)-measured spectra are in good agreement. Columnar size distributions inverted from the spectra show that the initial (July 1991) post-Pinatubo cloud was relatively rich in small particles (r<0.25 mum), which were progressively depleted in the August-September 1991 and July 1992 periods. Conversely, both of the later periods had more of the optically efficient medium-sized particles (0.25 25 pptv, the instruments agreed on average to about 15%. At mixing ratios < 25 pptv the agreement was about 5 pptv. For CS2 (mixing ratios < 50 pptv), two techniques agreed on average to about 4 pptv, and the third exhibited a bias (relative to the other two) that varied in the range of 3-7 pptv. CS2 mixing ratios over the ocean east of Natal as measured by the gas chromatograph-mass spectrometer technique were only a few pptv and were below the detection limits of the other two techniques. The CITE 3 data are used to estimate the current uncertainty associated with aircraft measurements of COS, H2S, and CS2 in the remote troposphere. C1 MAX PLANCK INST CHEM, ANTEILUNG BIOGEOCHEM, W-6500 MAINZ, GERMANY. DREXEL UNIV, COLL SCI, DEPT CHEM, PHILADELPHIA, PA 19104 USA. GEORGIA INST TECHNOL, SCH EARTH & ATMOSPHER SCI, ATLANTA, GA 30332 USA. NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, DIV MARINE & ATMOSPHER CHEM, MIAMI, FL 33149 USA. RP GREGORY, GL (reprint author), NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, MAIL STOP 483, HAMPTON, VA 23681 USA. RI Andreae, Meinrat/B-1068-2008 OI Andreae, Meinrat/0000-0003-1968-7925 NR 52 TC 10 Z9 10 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 1993 VL 98 IS D12 BP 23353 EP 23372 DI 10.1029/93JD00687 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MP295 UT WOS:A1993MP29500037 ER PT J AU ANDERSON, BE GREGORY, GL BARRICK, JDW COLLINS, JE SACHSE, GW BAGWELL, D SHIPHAM, MC BRADSHAW, JD SANDHOLM, ST AF ANDERSON, BE GREGORY, GL BARRICK, JDW COLLINS, JE SACHSE, GW BAGWELL, D SHIPHAM, MC BRADSHAW, JD SANDHOLM, ST TI THE IMPACT OF UNITED-STATES CONTINENTAL OUTFLOW ON OZONE AND AEROSOL DISTRIBUTIONS OVER THE WESTERN ATLANTIC SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-MONOXIDE; NORTH-AMERICA; TRANSPORT; OCEAN; EMISSIONS AB Aircraft measurements of selected trace gas species, aerosols, and meteorological parameters were performed in the lower troposphere off the U.S. east coast during August and September 1989 as part of the NASA Global Tropospheric Experiment (GTE) Chemical Instrumentation Test and Evaluation (CITE 3) expedition. In this paper, we examine these data to assess the impact of continental outflow on western Atlantic O3 and small aerosol budgets. Results show that mixed layer (ML) O3 concentrations and small aerosol number densities (Np) were enhanced by factors of 3 and 6, respectively, within airmasses of predominantly continental origin compared with clean maritime background air. These enhancements exhibited a marked altitude dependence, declining rapidly above the ML to the point where only slight to moderate differences in O3 and Np, respectively, were notable above 2.4 km. Within continentally influenced ML's, both O3 and Np were correlated with CO, exhibiting linear regression slopes averaging 0.4 ppb V(O3)/ppbv(CO) for O3 and 7.7 (particles cm-3)/ppbv(CO) for Np and indicating a primarily anthropogenic origin for the observed enhancement of these species. Comparisons between profiles in continental and background maritime air masses suggest that photochemical production below 1.4-km altitude adds over 10% to western Atlantic tropospheric column O3 abundance in continental outflow regimes. For aerosols, eastward advection of low-level continental air contributes an average net flux of 2.8 metric tons of submicron (accumulation mode) particles per kilometer of shoreline per day to the western Atlantic troposphere. C1 NASA, LANGLEY RES DIV, DIV OPERAT SUPPORT, HAMPTON, VA 23681 USA. GEORGIA INST TECHNOL, SCH EARTH & ATMOSPHER SCI, ATLANTA, GA 30332 USA. SCI & TECHNOL CORP, HAMPTON, VA 23665 USA. NASA, LANGLEY RES DIV, DIV FLIGHT ELECTR, HAMPTON, VA 23681 USA. RP ANDERSON, BE (reprint author), NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23681 USA. NR 29 TC 26 Z9 26 U1 2 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 1993 VL 98 IS D12 BP 23477 EP 23489 DI 10.1029/93JD01208 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MP295 UT WOS:A1993MP29500048 ER PT J AU ANDERSON, BE GREGORY, GL BARRICK, JDW COLLINS, JE SACHSE, GW HUDGINS, CH BRADSHAW, JD SANDHOLM, ST AF ANDERSON, BE GREGORY, GL BARRICK, JDW COLLINS, JE SACHSE, GW HUDGINS, CH BRADSHAW, JD SANDHOLM, ST TI FACTORS INFLUENCING DRY SEASON OZONE DISTRIBUTIONS OVER THE TROPICAL SOUTH-ATLANTIC SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CARBON-MONOXIDE; TROPOSPHERIC OZONE; CO AB Airborne measurements of trace gas and aerosol species were obtained in the lower troposphere (<5 km) over the western Atlantic Ocean between 13-degrees-S and 40-degrees-N during the August/September 1990 NASA Chemical Instrument Test and Evaluation (CITE 3) experiment. The largest background O3 Mixing ratios, averaging 35 and 70 ppbv within the mixed layer (ML) and free troposphere (FT; altitudes >2.4 km), respectively, were found over the tropical South Atlantic. Several competing processes were observed to regulate O3 budgets in this region. Within the ML, rapid photochemical destruction produced a diurnal O3 variation of 8 ppbv and an O3/altitude gradient between the surface and 5 km of almost 10 ppbV(O3) km-1. ML O3 concentrations were replenished by atmospheric downwelling which occurred at rates of up to and exceeding 1 cm s-1. Ozone values within the subsiding FT air were enriched both by long-range transport Of O3 produced photochemically within biomass combustion plumes and the downward propagation of dry, upper tropospheric air masses. Overall, the tropospheric O3 column below 3.3 km averaged 13.5 Dobson units (DU) over the South Atlantic region, which is 8-9 DU higher than observed during CITE 3 ferry flights over the northern tropical Atlantic Ocean or measured by ozonesondes over coastal Brazil during the wet season. An examination of simultaneous dew point and combustion tracer (e.g., CO) measurements suggests that the dry subsiding layers and biomass burning layers make approximately equal contributions to the observed O3 enhancement. C1 GEORGIA INST TECHNOL, SCH EARTH & ATMOSPHER SCI, ATLANTA, GA 30332 USA. NASA, LANGLEY RES CTR, DIV OPERAT SUPPORT, HAMPTON, VA 23681 USA. NASA, LANGLEY RES CTR, DIV FLIGHT ELECTR, HAMPTON, VA 23681 USA. SCI & TECHNOL CORP, HAMPTON, VA 23666 USA. RP ANDERSON, BE (reprint author), NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23681 USA. NR 24 TC 29 Z9 29 U1 1 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 1993 VL 98 IS D12 BP 23491 EP 23500 DI 10.1029/93JD01361 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MP295 UT WOS:A1993MP29500049 ER PT J AU DAVIS, DD CHEN, G CHAMEIDES, W BRADSHAW, J SANDHOLM, S RODGERS, M SCHENDAL, J MADRONICH, S SACHSE, G GREGORY, G ANDERSON, B BARRICK, J SHIPHAM, M COLLINS, J WADE, L BLAKE, D AF DAVIS, DD CHEN, G CHAMEIDES, W BRADSHAW, J SANDHOLM, S RODGERS, M SCHENDAL, J MADRONICH, S SACHSE, G GREGORY, G ANDERSON, B BARRICK, J SHIPHAM, M COLLINS, J WADE, L BLAKE, D TI A PHOTOSTATIONARY STATE ANALYSIS OF THE NO2-NO SYSTEM BASED ON AIRBORNE OBSERVATIONS FROM THE SUBTROPICAL TROPICAL NORTH AND SOUTH-ATLANTIC SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PHOTOCHEMISTRY EXPERIMENT; RADIOMETER MEASUREMENTS; TROPOSPHERIC CHEMISTRY; EASTERN; PACIFIC; OZONE; MODEL; HYDROCARBONS; COLORADO; RATIOS AB The Chemical Instrumentation Test and Evaluation 3 (CITE 3) NO-NO2 database has provided a unique opportunity to examine important aspects of tropospheric photochemistry as related to the rapid cycling between NO and NO2. Our results suggest that when quantitative testing of this photochemical system is based on airborne field data, extra precautions may need to be taken in the analysis. This was particularly true in the CITE 3 data analysis where different regional environments produced quite different results when evaluating the photochemical test ratio (NO2)Expt/(NO2)Calc, designated here as R(E)/R(C). The quantity (NO2)Calc was evaluated using the following photostationary state expression: [NO2]Calc = (k1[O3] + k4[HO2] + k5[CH3O2] + k6[RO2])[NO]Expt/J2. The four most prominent regional environmental data sets identified in this analysis were those labeled here as free-tropospheric northern hemisphere (FTNH), free-tropospheric tropical northern hemisphere (FTTNH), free-tropospheric southern hemisphere (FTSH), and tropical-marine boundary layer (plume) (TMBL(P)). The respective R(E)/R(C) mean and median values for these four data subsets were 1.74, 1.69; 3.00, 2.79; 1.01, 0.97; and 0.99, 0.94. Of the four data subsets listed, the two that were statistically the most robust were FTNH and FTSH; for these the respective R(E)/R(C) mean and standard deviation of the mean values were 1.74 +/- 0.07 and 1.01, +/- 0.04. The FTSH observations were in good agreement with theory, whereas those from the FTNH data set were in significant disagreement. An examination of the critical photochemical parameters O3, UV(zenith), NO, NO2, and non-methane hydrocarbons (NMHCs) for these two databases indicated that the most likely source of the R(E)/R(C) bias in the FTNH results was the presence of a systematic error in the observational data rather than a shortcoming in our understanding of fundamental photochemical processes. Although neither a chemical nor meteorological analyses of these data identified this error with complete certainty, they did point to the three most likely possibilities: (1) an NO2 interference from a yet unidentified NO(y) species; (2) the presence of unmeasured hydrocarbons, the integrated reactivity of which would be equivalent to approximately 2.7 parts per billion by volume (ppbv) of toluene; or (3) some combination of points (1) and (2). Details concerning hypotheses (1) and (2) as well as possible ways to minimize these problems in future airborne missions are discussed. C1 UNIV CALIF IRVINE, IRVINE, CA 92717 USA. GEORGIA INST TECHNOL, SCH EARTH & ATMOSPHER SCI, ATLANTA, GA 30332 USA. SCI & TECHNOL CORP, HAMPTON, VA 23665 USA. NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. PLANNING RES CORP, HAMPTON, VA 23666 USA. RP DAVIS, DD (reprint author), NASA, LANGLEY RES CTR, HAMPTON, VA 23665 USA. RI Madronich, Sasha/D-3284-2015 OI Madronich, Sasha/0000-0003-0983-1313 NR 48 TC 56 Z9 58 U1 0 U2 6 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 1993 VL 98 IS D12 BP 23501 EP 23523 DI 10.1029/93JD02412 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MP295 UT WOS:A1993MP29500050 ER PT J AU SULLIVAN, CW ARRIGO, KR MCCLAIN, CR COMISO, JC FIRESTONE, J AF SULLIVAN, CW ARRIGO, KR MCCLAIN, CR COMISO, JC FIRESTONE, J TI DISTRIBUTIONS OF PHYTOPLANKTON BLOOMS IN THE SOUTHERN-OCEAN SO SCIENCE LA English DT Article ID ANTARCTIC CIRCUMPOLAR CURRENT; ATMOSPHERIC PCO2; WEDDELL SEA; IRON; ACCUMULATION; DYNAMICS; ATLANTIC; ECOLOGY; CARBON; WATERS AB A regional pigment retrieval algorithm for the Nimbus-7 Coastal Zone Color Scanner (CZCS) has been tested for the Southern Ocean. The pigment concentrations estimated with this algorithm agree to within 5 percent with in situ values and are more than twice as high as those previously reported. The CZCS data also revealed an asymmetric distribution of enhanced pigments in the waters surrounding Antarctica; in contrast, most surface geophysical properties are symmetrically distributed. The asymmetry is coherent with circumpolar current patterns and the availability of silicic acid in surface waters. Intense blooms (> 1 milligram of pigment per cubic meter) that occur downcurrent from continental masses result from dissolved trace elements such as iron derived from shelf sediments and glacial melt. C1 UNIV SO CALIF,HANCOCK INST MARINE STUDIES,GRAD PROGRAM OCEAN SCI,LOS ANGELES,CA 90089. GEN SCI CORP,LAUREL,MD 20707. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 52 TC 253 Z9 258 U1 2 U2 19 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 17 PY 1993 VL 262 IS 5141 BP 1832 EP 1837 DI 10.1126/science.262.5141.1832 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MM511 UT WOS:A1993MM51100025 PM 17829629 ER PT J AU WALKER, D NORBY, L JONES, JH AF WALKER, D NORBY, L JONES, JH TI SUPERHEATING EFFECTS ON METAL-SILICATE PARTITIONING OF SIDEROPHILE ELEMENTS SO SCIENCE LA English DT Article ID FE-NI-S; EARTHS FORMATION; CORE; MANTLE AB Liquid metal-liquid silicate partition coefficients for several elements at 100 kilobars and temperatures up to about 3000 kelvin in carbon capsules experimentally converge on unity with increasing temperature. The sense of change of the partition coefficients with temperature resembles the extrapolation of Murthy and may partially contribute to, but by no means provide a complete resolution of, the ''excess'' siderophile problem in the Earth's mantle. Sulfur and perhaps carbon successfully compete with oxygen for sites in the metallic liquid at these temperatures and pressures. This observation casts doubt upon the hypothesis that oxygen is the light element in the Earth's core. C1 COLUMBIA UNIV,DEPT GEOL SCI,PALISADES,NY 10964. NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. RP WALKER, D (reprint author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964, USA. NR 18 TC 73 Z9 73 U1 0 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 17 PY 1993 VL 262 IS 5141 BP 1858 EP 1861 DI 10.1126/science.262.5141.1858 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MM511 UT WOS:A1993MM51100031 PM 17829633 ER PT J AU TSELIOUDIS, G LACIS, AA RIND, D ROSSOW, WB AF TSELIOUDIS, G LACIS, AA RIND, D ROSSOW, WB TI POTENTIAL EFFECTS OF CLOUD OPTICAL-THICKNESS ON CLIMATE WARMING SO NATURE LA English DT Article ID FEEDBACK; SENSITIVITY; MODEL AB CLIMATE warming can cause changes in the optical properties of low clouds, which may in turn amplify or diminish the warming1,2. But both the sign and magnitude of such feedbacks have been uncertain, largely because the observational evidence for variations in the large-scale optical properties of clouds has been very limited. Recently, analysis of data from the International Satellite Cloud Climatology Project yielded a relationship between low-cloud optical thickness and cloud temperature that implies a positive feed-back between clouds and climate3. Here we use a two-dimensional radiative-convective model to assess the effect of such a feedback on the climate change associated with a doubling of the atmospheric carbon dioxide concentration. We find that, zonally averaged, the feedback is positive in the Northern Hemisphere and is stronger at lower than at higher latitudes. The positive feedback amplifies the overall global climate sensitivity, and the latitudinal gradient in the strength of the feedback acts to eliminate the high-latitude amplification of the greenhouse warming predicted by most climate models. C1 COLUMBIA UNIV,NEW YORK,NY 10027. RP TSELIOUDIS, G (reprint author), NASA,GODDARD INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA. RI Lacis, Andrew/D-4658-2012; Rossow, William/F-3138-2015 NR 15 TC 16 Z9 17 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD DEC 16 PY 1993 VL 366 IS 6456 BP 670 EP 672 DI 10.1038/366670a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MM265 UT WOS:A1993MM26500064 ER PT J AU HOCHSTEIN, LI LAWSON, D AF HOCHSTEIN, LI LAWSON, D TI IS ATP SYNTHESIZED BY A VACUOLAR-ATPASE IN THE EXTREMELY HALOPHILIC BACTERIA SO EXPERIENTIA LA English DT Review DE HALOBACTERIAL ATPASE; ARCHAEAL ATPASES; ATP SYNTHESIS; HALOBACTERIUM; HALOARCULA; HALOFERAX ID CELL-ENVELOPE VESICLES; MEMBRANE-BOUND ATPASE; HALOBACTERIUM-SACCHAROVORUM; SULFOLOBUS-ACIDOCALDARIUS; ACIDOTHERMOPHILIC ARCHAEBACTERIUM; METHANOSARCINA-BARKERI; ALPHA-SUBUNIT; BETA-SUBUNIT; HALOBIUM; PURIFICATION AB The proton-dependent synthesis of ATP was demonstrated in representative members of the genera Halobacterium, Haloarcula, and Haloferax. In all cases, synthesis was not inhibited by nitrate or N-ethylmaleimide, inhibitors of the vacuolar-like ATPases found in Archaea, but was affected by azide, an inhibitor of F0F1-ATP synthases. These observations extend the earlier observations with Halobacterium saccharovorum and suggest that ATP synthesis in these organisms is brought about by an F0F1-ATP synthase. RP HOCHSTEIN, LI (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 32 TC 3 Z9 4 U1 0 U2 0 PU BIRKHAUSER VERLAG AG PI BASEL PA PO BOX 133 KLOSTERBERG 23, CH-4010 BASEL, SWITZERLAND SN 0014-4754 J9 EXPERIENTIA JI Experientia PD DEC 15 PY 1993 VL 49 IS 12 BP 1059 EP 1063 DI 10.1007/BF01929914 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MN837 UT WOS:A1993MN83700007 ER PT J AU DUBOVIKOV, MS AF DUBOVIKOV, MS TI DYNAMICAL MODEL OF TURBULENT EDDIES SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article ID RANDOMLY STIRRED FLUID; RENORMALIZATION-GROUP; FIELD AB Dynamical equations for the velocities and temperature fluctuations of turbulent eddies are presented. In the right side of the equation for the velocities are the external force, the turbulent force caused by interactions with larger-scale eddies, and the viscous force caused by interactions with smaller-scale eddies. The structure of the equation for the temperature fluctuations is analogous. The forces are specified on the basis of the well-known Wyld diagram technique of stochastic hydrodynamics so that the theory does not contain free parameters. The basic equations of the theory are approximately equivalent to Navier-Stokes equations and are particularly effective in the limit of very large Reynolds number. Turbulent convection is considered as an example of application of the basic equations. RP DUBOVIKOV, MS (reprint author), NASA,GODDARD INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA. NR 34 TC 1 Z9 1 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 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD DEC 15 PY 1993 VL 7 IS 27 BP 4631 EP 4645 DI 10.1142/S0217979293003796 PG 15 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA MQ222 UT WOS:A1993MQ22200005 ER PT J AU PARTRIDGE, H SCHWENKE, DW BAUSCHLICHER, CW AF PARTRIDGE, H SCHWENKE, DW BAUSCHLICHER, CW TI THEORETICAL-STUDY OF THE GROUND-STATES OF THE RARE-GAS HYDRIDES, HEH, NEH, AND ARH SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GAUSSIAN-BASIS SETS; GTO BASIS-SETS; DIPOLE POLARIZABILITIES; VANDERWAALS POTENTIALS; ELECTRON CORRELATION; TRIPLE EXCITATIONS; 2ND-ROW ATOMS; CROSS-SECTION; H-NE; SCATTERING AB Potential energy curves for HeH, NeH, and ArH are determined using large basis sets and high levels of theory. The computed potential energy curves are in excellent agreement with the experimentally determined model potentials for HeH and NeH, but differ with the model potentials deduced for ArH by Tang and Toennies. We derive a potential based on the ab initio calculations and our best estimate of the well depth; using this potential we are able to reproduce the results of the orbiting resonance experiments of Toennies and co-workers. RP PARTRIDGE, H (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. RI schwenke, david/I-3564-2013 NR 54 TC 19 Z9 19 U1 0 U2 6 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 1993 VL 99 IS 12 BP 9776 EP 9782 DI 10.1063/1.466206 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA MM413 UT WOS:A1993MM41300045 ER PT J AU LEE, TJ AF LEE, TJ TI A COUPLED-CLUSTER STUDY OF XNO (X=H,F,CL) - AN INVESTIGATION OF WEAK X-N SINGLE BONDS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GAUSSIAN-BASIS SETS; MOLECULAR CALCULATIONS; NITROSYL FLUORIDE; CONFIGURATION-INTERACTION; VIBRATIONAL FREQUENCIES; EQUILIBRIUM STRUCTURE; 2ND-ROW ATOMS; FORCE-FIELDS; ROW ATOMS; ABINITIO AB Singles and doubles coupled-cluster (CCSD) theory and the CCSD(T) method, CCSD plus a perturbational estimate of the effects of connected triple excitations, have been used to determine the equilibrium structures, dipole moment, vibrational frequencies, and infrared intensities of the HNO, FNO, and ClNO species. A double polarized triple-zeta (TZ2P) quality basis set was used. The CCSD (T) results are found to be in very good agreement with experiment, indicating that the CCSD(T) method performs well in describing the weak X-NO single bond. The experimental heats of formation of the FNO, and ClNO species are examined for internal consistency with experimental data for FNO2 and ClNO2, by using an isodesmic reaction. It is concluded that the experimental data exhibit a small inconsistency. An approach, involving in addition the use of homodesmic reactions, by which a more consistent set of thermochemical data may be obtained is proposed and discussed. RP LEE, TJ (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RI Lee, Timothy/K-2838-2012 NR 50 TC 38 Z9 38 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 1993 VL 99 IS 12 BP 9783 EP 9789 DI 10.1063/1.465460 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA MM413 UT WOS:A1993MM41300046 ER PT J AU NIILER, PP FILLOUX, J LIU, WT SAMELSON, RM PADUAN, JD PAULSON, CA AF NIILER, PP FILLOUX, J LIU, WT SAMELSON, RM PADUAN, JD PAULSON, CA TI WIND-FORCED VARIABILITY OF THE DEEP EASTERN NORTH PACIFIC - OBSERVATIONS OF SEA-FLOOR PRESSURE AND ABYSSAL CURRENTS SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID DRIVEN CURRENT FLUCTUATIONS; OCEANIC RESPONSE; STRESS CURL; ATLANTIC AB Data from an array of bottom pressure gauges and a string of current meters in the vicinity of 47-degrees-N, 139-degrees-W, are used to examine the deep-ocean variability forced by ocean surface wind stress curl from August 1987 to June 1988. Bottom geostrophic currents are computed from the pressure gauge array, and these correspond well to the long-period directly measured currents at 3000 m. The supratidal-period bottom pressure variations are coherent at 95% confidence with the wind stress curl in period bands of 3-4 days and 15-60 days but removed in distances of 400 and 700 km to the northwest and the southeast, respectively. A linear, two-layer hydrodynamic model is used to examine the theoretical forcing produced by random-phased surface wind fields for the conditions of the eastern north Pacific and the 15- to 60-day-period observed response is reproduced credibly. To model 3- to 15-day variations, more realistic models are required. C1 JET PROP LAB,PASADENA,CA 91109. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. OREGON STATE UNIV,COLL OCEAN & ATMOSPHER SCI,CORVALLIS,OR 97331. RP NIILER, PP (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. NR 21 TC 22 Z9 22 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 1993 VL 98 IS C12 BP 22589 EP 22602 DI 10.1029/93JC01288 PG 14 WC Oceanography SC Oceanography GA MU345 UT WOS:A1993MU34500007 ER PT J AU HOGE, FE SWIFT, RN YUNGEL, JK VODACEK, A AF HOGE, FE SWIFT, RN YUNGEL, JK VODACEK, A TI FLUORESCENCE OF DISSOLVED ORGANIC-MATTER - A COMPARISON OF NORTH PACIFIC AND NORTH-ATLANTIC OCEANS DURING APRIL 1991 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID OPTICAL ATTENUATION; COLOR MEASUREMENT; CHLOROPHYLL; PHYTOPLANKTON; SATELLITE; PATTERNS; PIGMENTS; RIVERS; CARBON AB Profiles of airborne-laser-induced fluorescence emission from dissolved organic matter in the upper ocean have been produced and compared for the Southern California Bight (SCB) and the Mid-Atlantic Bight (MAB). Findings were as follows. (1) The fluorescent components of dissolved organic matter (FDOM) are present in easily measurable quantities from near shore to well over 300 km offshore in the SCB and are likewise easily measurable in the coastal, shelf, slope, and Gulf Stream waters of the MAB. (2) The range of FDOM in the MAB is considerably greater than that in the SCB. (3) The lowest FDOM levels observed in the SCB were higher than those found in the Gulf Stream. (4) The onshore-to-offshore spatial gradient of the FDOM was found to be considerably lower in the SCB than in the MAB, with the highest levels of FDOM being found immediately adjacent to the coast in the MAB. This suggests that the water adjacent to the SCB shoreline is not as strongly influenced by terrestrial and estuarine sources of FDOM as the MAB is. (5) The spatial distribution of the FDOM within both the SCB and the MAB is frequently coherent with the spatial distribution of chlorophyll determined from the concurrent airborne-laser-induced phytoplankton pigment fluorescence measurements. However, distinct noncoherency is sometimes observed, especially at water mass boundaries. C1 EG&G INC,WALLOPS FLIGHT FACIL,WALLOPS ISL,VA 23337. NATL RES COUNCIL,WALLOPS FLIGHT FACIL,WALLOPS ISL,VA 23337. RP HOGE, FE (reprint author), 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 31 TC 21 Z9 21 U1 0 U2 7 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 1993 VL 98 IS C12 BP 22779 EP 22787 DI 10.1029/93JC01772 PG 9 WC Oceanography SC Oceanography GA MU345 UT WOS:A1993MU34500022 ER PT J AU HURWITZ, FI HEIMANN, P FARMER, SC HEMBREE, DM AF HURWITZ, FI HEIMANN, P FARMER, SC HEMBREE, DM TI CHARACTERIZATION OF THE PYROLYTIC CONVERSION OF POLYSILSESQUIOXANES TO SILICON OXYCARBIDES SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID POLYCARBOSILANE PRECURSOR; SIC FIBERS; GLASSES; REDISTRIBUTION; MECHANISMS; CHEMISTRY; GRAPHITE AB A series of silsesquioxane copolymers synthesized by hydrolysis and condensation of phenyl- and methyltrimethoxysilanes have been studied as preceramic polymers. The pyrolytic conversion to ceramics was characterized by thermogravimetric analysis, Si-29 and C-13 nuclear magnetic resonance and Raman spectroscopy. The pyrolysed materials were further characterized by differential thermal analysis, X-ray diffractometry and transmission electron microscopy. The ratio of phenyl to methyl groups in the copolymer was found to control polymer structure and rheology, as well as ceramic composition and char yield. On pyrolysis to 1000-degrees-C under inert conditions, silicon oxycarbides were formed, along with glassy carbon. On heating from 1200-degrees-C to 1400-degrees-C, the oxycarbide structure diminished, and the materials were comprised primarily of amorphous silica, amorphous Si-C, some small crystallite SiC and graphitic carbon. The carbon content increased, and char yield decreased, with increasing concentration of phenyl groups in the copolymer. The presence of free carbon appears to inhibit the crystallization of silica. Significant carbothermal reduction was observed only above 1500-degrees-C. Oxidation studies of the pyrolysed materials indicated the presence of at least two forms of carbon. C1 MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE Y12 PLANT,OAK RIDGE,TN 37831. RP HURWITZ, FI (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 30 TC 119 Z9 121 U1 6 U2 23 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 1993 VL 28 IS 24 BP 6622 EP 6630 DI 10.1007/BF00356406 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA MN415 UT WOS:A1993MN41500018 ER PT J AU LEWIS, DK BRANDT, B CROCKFORD, L GLENAR, DA RAUSCHER, G RODRIGUEZ, J BALDWIN, JE AF LEWIS, DK BRANDT, B CROCKFORD, L GLENAR, DA RAUSCHER, G RODRIGUEZ, J BALDWIN, JE TI CONCERTED AND NONCONCERTED PATHWAYS FOR THERMAL-CONVERSIONS OF DEUTERIUM-LABELED CYCLOHEXENES TO BUTADIENES AND ETHYLENES SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DIELS-ALDER REACTION; DIODE-LASER SPECTROSCOPY; TRANSITION-STATE; MECHANISM; ISOMERIZATION; KINETICS; BICYCLO<3.2.0>HEPT-2-ENE; BICYCLO<2.2.1>HEPT-2-ENE; STEREOCHEMISTRY; CYCLOPROPANE AB The retro Diels-Alder reactions of cyclohexene-3,3,6,6-d4 and the 4,5-cis isomers of cyclohexene-1,2,3,4,5,6-d6 have been followed using single-pulse shock tube kinetic and tunable diode laser infrared spectroscopic techniques. At temperatures above 1000 K, both labeled cyclohexenes give some products indicative of nonconcerted reaction paths: ethylene-1,1-d2 from the first and trans-ethylene-1,2-d2 from the second. Kinetic modeling calculations indicate that the most important pathway for formation of these products is a sequence of steps: cyclohexene --> vinylcyclobutane --> ethylene plus butadiene. Some relatively minor direct conversion of cyclohexene to ethylene plus butadiene through a stereochemically nonconservative pathway involving a diradical intermediate may also occur. C1 SYRACUSE UNIV,DEPT CHEM,SYRACUSE,NY 13244. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP LEWIS, DK (reprint author), COLGATE UNIV,DEPT CHEM,HAMILTON,NY 13346, USA. NR 68 TC 15 Z9 15 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD DEC 15 PY 1993 VL 115 IS 25 BP 11728 EP 11734 DI 10.1021/ja00078a011 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA MM514 UT WOS:A1993MM51400011 ER PT J AU WANG, SP AF WANG, SP TI MODELING MARINE BOUNDARY-LAYER CLOUDS WITH A 2-LAYER MODEL - A ONE-DIMENSIONAL SIMULATION SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TOP ENTRAINMENT INSTABILITY; STRATOCUMULUS CONVECTION; THERMODYNAMIC STRUCTURE; FRACTIONAL CLOUDINESS; PARAMETERIZATION; FORMULATION; BREAKUP AB A two-layer model of the marine boundary layer is described. The model is used to simulate both stratocumulus and shallow cumulus clouds in downstream simulations. Over cold sea surfaces, the model predicts a relatively uniform structure in the boundary layer with 90%-100% cloud fraction. Over warm sea surfaces, the model predicts a relatively strong decoupled and conditionally unstable structure with a cloud fraction between 30% and 60%. A strong large-scale divergence considerably limits the height of the boundary layer and decreases relative humidity in the upper part of the cloud layer; thus, a low cloud fraction results. The effects of drizzle on the boundary-layer structure and cloud fraction are also studied with downstream simulations. It is found that drizzle dries and stabilizes the cloud layer and tends to decouple the cloud from the subcloud layer. Consequently, solid stratocumulus clouds may break up and the cloud fraction may decrease because of drizzle. RP WANG, SP (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,ES-42,HUNTSVILLE,AL 35812, USA. NR 54 TC 31 Z9 31 U1 0 U2 0 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 15 PY 1993 VL 50 IS 24 BP 4001 EP 4021 DI 10.1175/1520-0469(1993)050<4001:MMBLCW>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MN439 UT WOS:A1993MN43900005 ER PT J AU WANG, SP ALBRECHT, BA MINNIS, P AF WANG, SP ALBRECHT, BA MINNIS, P TI A REGIONAL SIMULATION OF MARINE BOUNDARY-LAYER CLOUDS SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TOP ENTRAINMENT INSTABILITY; STRATOCUMULUS CLOUDS; MODEL; PARAMETERIZATION; SATELLITE; SENSITIVITY; CIRCULATION; FIRE AB A regional version of a two-layer model is used to simulate marine boundary-layer clouds over an area (20-degrees - 42-degrees-N and 117-degrees - 145-degrees-W) of the eastern North Pacific. The large-scale conditions required for the model are provided by European Centre for Medium-Range Weather Forecasts analyses and the Comprehensive Ocean-Atmosphere Data Set. The simulated cloud-top height and fractional cloudiness are compared with satellite data. The model predicts a realistic pattern of cloud-top height, although the heights appear to be overestimated in the southwest and underestimated along the eastern border of the domain. The overall simulated cloudiness is qualitatively comparable to the satellite derived, but the model predicts excessive cloudiness over cold ocean surfaces and insufficient cloudiness over an area centered at 30-degrees-N, 130-degrees-W. The possible causes for these discrepancies are discussed. Budget studies show that horizontal advection contributes substantially to the cloud-top height and cloud-layer moisture budgets. Thus, one may need to consider the effects of horizontal advection when validating steady-state solutions of a one-dimensional model. The simulated cloudiness is shown to be sensitive to large-scale subsidence, moisture above the clouds, and drizzle. An increase in the large-scale divergence by 2 x 10(-6) s-1 decreases average cloudiness for the area by 30%. An increase in the moisture at 850 mb by 2 g kg-1 increases the cloudiness by 20%. The suppression of drizzle in the model increases the cloudiness by 34% and significantly changes its pattern. C1 PENN STATE UNIV,DEPT METEOROL,UNIV PK,PA 16802. PENN STATE UNIV,CTR EARTH SCI SYST,UNIV PK,PA 16802. NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,HAMPTON,VA 23665. RP WANG, SP (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,FS-42,HUNTSVILLE,AL 35812, USA. RI Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 43 TC 23 Z9 23 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 15 PY 1993 VL 50 IS 24 BP 4022 EP 4043 DI 10.1175/1520-0469(1993)050<4022:ARSOMB>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MN439 UT WOS:A1993MN43900006 ER PT J AU SMITH, MD GIERASCH, PJ SCHINDER, PJ AF SMITH, MD GIERASCH, PJ SCHINDER, PJ TI GLOBAL-SCALE WAVES IN THE VENUS ATMOSPHERE SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID CLOUD TOP LEVEL; SEMIDIURNAL TIDE; THERMAL TIDES; ZONAL WINDS; GALILEO; MODEL; CIRCULATION; PATTERNS AB The nature of global-scale waves that can exist in the atmosphere of Venus is examined. A linear three-dimensional model atmosphere with spherical geometry is used to study large-scale forced and free waves. Solutions are obtained numerically with grid points in the vertical and a spherical harmonic expansion in the horizontal. Observations have shown a global-scale traveling wave with phase speed near the cloud-top wind velocity. Global-scale wave modes are found to exist in the model at this velocity. When a radiative-dynamic cloud feedback is added to the model, the most unstable wave mode is found to have the same phase speed as the observed wave. The horizontal structure of this wave is consistent with the observed horizontal structure of the ''Y'' feature seen in ultraviolet images of the Venus cloud top. C1 NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. RP SMITH, MD (reprint author), CORNELL UNIV,DEPT ASTRON,320 SPACE SCI BLDG,ITHACA,NY 14853, USA. RI Smith, Michael/C-8875-2012 NR 29 TC 18 Z9 18 U1 0 U2 0 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 15 PY 1993 VL 50 IS 24 BP 4080 EP 4096 DI 10.1175/1520-0469(1993)050<4080:GSWITV>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MN439 UT WOS:A1993MN43900009 ER PT J AU HARDING, AK OZERNOY, LM USOV, VV AF HARDING, AK OZERNOY, LM USOV, VV TI GEMINGA - ORIGINS OF ITS X-RAY AND GAMMA-RAY EMISSION SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE RADIATION MECHANISMS, MISCELLANEOUS; STARS, NEUTRON; PULSARS, INDIVIDUAL, GEMINGA (2GC 195+04, 1 E 0630+178); GAMMA-RAYS, OBSERVATIONS; X-RAYS, STARS ID STRONG MAGNETIC-FIELD; PULSAR POLAR CAPS; ELECTROMAGNETIC CASCADES; RADIATION; GAPS AB The ratio of X-ray to gamma-ray emission from the Geminga pulsar is explained, independently of the distance to the pulsar, by Arons' model for the production of relativistic particles near the pulsar surface at the polar caps. Polar cap heating by both reversed particles and their curvature radiation is able to explain the observed ratio of soft to hard X-ray components. This model predicts the distance to Geminga as D similar or equal to 20 pc (4 pi/Omega)(1/4), where Omega, the emission solid angle, may differ from 4 pi by a factor of 2-3 or so. C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. GEORGE MASON UNIV,INST COMPUTAT SCI & INFORMAT,FAIRFAX,VA 22030. WEIZMANN INST SCI,DEPT PHYS,IL-76100 REHOVOT,ISRAEL. RP HARDING, AK (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. RI Harding, Alice/D-3160-2012 NR 35 TC 25 Z9 25 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 1993 VL 265 IS 4 BP 921 EP 925 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MM311 UT WOS:A1993MM31100017 ER PT J AU DAVIES, JK MUMMA, MJ REUTER, DC HOBAN, S WEAVER, HA PUXLEY, PJ LUMSDEN, SL AF DAVIES, JK MUMMA, MJ REUTER, DC HOBAN, S WEAVER, HA PUXLEY, PJ LUMSDEN, SL TI THE INFRARED (3.2-3.6 MU-M) SPECTRUM OF COMET P/SWIFT-TUTTLE - DETECTION OF METHANOL AND OTHER ORGANICS SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE LINE, IDENTIFICATION; MOLECULAR DATA; COMETS, INDIVIDUAL, P/SWIFT-TUTTLE; INFRARED, SOLAR SYSTEM ID EMISSION FEATURE; P/BRORSEN-METCALF; FORMALDEHYDE; HALLEY; LEVY; IDENTIFICATION AB We present an infrared spectrum of comet P/Swift-Tuttle which exhibits broad emission features at 3.4 and 3.52 mu m with fluxes of (5.7 +/- 0.25) x10(-15) and (0.8 +/- 0.14) x10(-15) Wm(12) respectively, but has no pronounced feature near 3.28 mu m. We show that the 3.52-mu m feature and much of the 3.4-mu m emission can be attributed to fluorescence from methanol, but that some other source is required to explain residual emission centred on 3.43 mu m. The derived methanol production rate is (1.6 +/- 0.3) X10(28) molecule s(-1) which implies a ratio of methanol to water of approximately 0.05, a value more typical of dynamically new comets than of periodic comets. C1 ROYAL OBSERV, EDINBURGH EH9 3HJ, MIDLOTHIAN, SCOTLAND. NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, GREENBELT, MD 20771 USA. NASA, GODDARD SPACE FLIGHT CTR, UNIV SPACE RES ASSOC, GREENBELT, MD 20771 USA. SPACE TELESCOPE SCI INST, BALTIMORE, MD 21218 USA. ANGLO AUSTRALIAN OBSERV, EPPING, NSW, AUSTRALIA. RI mumma, michael/I-2764-2013; Weaver, Harold/D-9188-2016 NR 30 TC 15 Z9 15 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 15 PY 1993 VL 265 IS 4 BP 1022 EP 1026 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MM311 UT WOS:A1993MM31100026 ER PT J AU WALKER, KP FREED, AD JORDAN, EH AF WALKER, KP FREED, AD JORDAN, EH TI ACCURACY OF THE GENERALIZED SELF-CONSISTENT METHOD IN MODELING THE ELASTIC BEHAVIOR OF PERIODIC COMPOSITES SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article ID HETEROGENEOUS MEDIA; RANDOM SUSPENSION; UNIFORM-FIELDS; SPHERES; MODULI; CONDUCTIVITY; CONSTANTS; BODY AB Local stress and strain fields in the unit cell of an infinite, two-dimensional, periodic fibrous lattice have been determined by an integral equation approach. The effect of the fibres is assimilated to an infinite two-dimensional array of fictitious body forces in the matrix constituent phase of the unit cell. By subtracting a volume averaged strain polarization term from the integral equation we effectively embed a finite number of unit cells in a homogenized medium in which the overall stress and strain correspond to the volume averaged stress and strain of the constrained unit cell. This paper demonstrates that the zeroth term in the governing integral equation expansion, which embeds one unit cell in the homogenized medium, corresponds to the generalized self-consistent approximation By comparing the zeroth term approximation with higher order approximations to the integral equation summation, both the accuracy of the generalized self-consistent composite model and the rate of convergence of the integral summation can be assessed. Two example composites are studied. For a tungsten/copper elastic fibrous composite the generalized self-consistent model is shown to provide accurate, effective, elastic moduli and local field representations. The local elastic transverse stress field within the representative volume element of the generalized self-consistent method is shown to be in error by much larger amounts for a composite with periodically distributed voids, but homogenization leads to a cancelling of errors, and the effective transverse Young's modulus of the voided composite is shown to be in error by only 23% at a void volume fraction of 75%. C1 NASA, LEWIS RES CTR, CLEVELAND, OH 44135 USA. UNIV CONNECTICUT, STORRS, CT 06268 USA. RP ENGN SCI SOFTWARE INC, SMITHFIELD, RI 02917 USA. NR 57 TC 11 Z9 11 U1 0 U2 1 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X EI 1471-2962 J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD DEC 15 PY 1993 VL 345 IS 1677 BP 545 EP 576 DI 10.1098/rsta.1993.0144 PG 32 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MN357 UT WOS:A1993MN35700005 ER PT J AU GOOD, B BOZZOLO, G FERRANTE, J AF GOOD, B BOZZOLO, G FERRANTE, J TI SURFACE SEGREGATION IN CU-NI ALLOYS SO PHYSICAL REVIEW B LA English DT Note ID AUGER-ELECTRON SPECTROSCOPY; NICKEL-COPPER ALLOYS; EQUIVALENT-CRYSTAL THEORY; ENERGY ION-SCATTERING; ATOM-PROBE FIM; BINARY-ALLOYS; DEPTH PROFILE; QUANTITATIVE-ANALYSIS; CARBON-MONOXIDE; SOLID-SOLUTIONS AB Monte Carlo simulation is used to calculate the composition profiles of surface segregation of Cu-Ni alloys. The method of Bozzolo, Ferrante, and Smith [Phys. Rev. B 45, 493 (1992)] is used to compute the energetics of these systems as a function of temperature, crystal face, and bulk concentration. The predictions are compared with other theoretical and experimental results. C1 ANALEX CORP,BROOKPARK,OH 44142. RP GOOD, B (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 64 TC 20 Z9 20 U1 1 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1993 VL 48 IS 24 BP 18284 EP 18287 DI 10.1103/PhysRevB.48.18284 PG 4 WC Physics, Condensed Matter SC Physics GA MQ165 UT WOS:A1993MQ16500079 ER PT J AU KAISER, WJ HECHT, MH BELL, LD GRUNTHANER, FJ LIU, JK DAVIS, LC AF KAISER, WJ HECHT, MH BELL, LD GRUNTHANER, FJ LIU, JK DAVIS, LC TI BALLISTIC-ELECTRON-EMISSION MICROSCOPY OF ELECTRON-TRANSPORT THROUGH ALAS/GAAS HETEROSTRUCTURES SO PHYSICAL REVIEW B LA English DT Note ID BAND-STRUCTURE; GAAS; SEMICONDUCTORS; INTERFACES; ALAS AB BEEM spectroscopy has been used to characterize hot-carrier transport through AlAs/GaAs heterostructures. The dependence of electron transmission on AlAs thickness has been directly measured, and the position of the AlAs L(1) minima, which has been subject to some uncertainty in the past, has been determined. First-principles transmission calculations, based on a tight-binding formalism, are compared to the results of BEEM spectroscopy. C1 FORD MOTOR CO,RES STAFF,DEARBORN,MI 48121. RP KAISER, WJ (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109, USA. NR 23 TC 48 Z9 48 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 1993 VL 48 IS 24 BP 18324 EP 18327 DI 10.1103/PhysRevB.48.18324 PG 4 WC Physics, Condensed Matter SC Physics GA MQ165 UT WOS:A1993MQ16500089 ER PT J AU TURNER, MS AF TURNER, MS TI RECOVERING THE INFLATIONARY POTENTIAL SO PHYSICAL REVIEW D LA English DT Article ID DIFFERENTIAL MICROWAVE RADIOMETER; FLUCTUATION SPECTRA; EXTENDED INFLATION; COBE; ANISOTROPY; SCENARIO; MODELS AB A procedure is developed for the recovery of the inflationary potential over the interval that affects astrophysical scales (approximate to 1 Mpc to 10(4) Mpc). The amplitudes of the scalar and tenser metric perturbations and their power-spectrum indices, which in principle can be inferred from large-angle CBR anisotropy and other cosmological data, determine the value of the inflationary potential and its first two derivatives. From these, the inflationary potential can be reconstructed in a Taylor series and the consistency of the inflationary hypothesis tested. Examples are presented, and the effect of observational uncertainties is discussed. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP TURNER, MS (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637, USA. NR 37 TC 68 Z9 68 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 15 PY 1993 VL 48 IS 12 BP 5539 EP 5545 DI 10.1103/PhysRevD.48.5539 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA MP573 UT WOS:A1993MP57300012 ER PT J AU CHEN, JS KOLAWA, E NICOLET, MA POOL, FS AF CHEN, JS KOLAWA, E NICOLET, MA POOL, FS TI THERMAL-REACTION OF TA THIN-FILMS WITH POLYCRYSTALLINE DIAMOND SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 20th International Conference on Metallurgical Coatings and Thin Films CY APR 19-23, 1993 CL SAN DIEGO, CA ID CARBIDE-FORMING METAL; ELECTRICAL-PROPERTIES; OHMIC CONTACTS; SEMICONDUCTING DIAMOND; CHEMICAL NATURE; NUCLEATION; INTERFACE AB The thermal reaction of sputter-deposited Ta thin films with polycrystalline CVD-grown diamond substrates at temperatures between 700 degrees C and 1100 degrees C for 1 h is investigated by MeV He backscattering spectrometry, X-ray diffraction, and scanning electron microscopy. The product phases are polycrystalline Ta2C at 900 degrees C and TaC at 1000 degrees C with an initially 135 nm thick Ta film. The first phase formed conforms to the rule of Bene for metal-metal bilayers. No coexistence of Ta2C and TaC is observed during reaction. The second phase formed, TaC, is in thermodynamic equilibrium with carbon. C1 JET PROPULS LAB,PASADENA,CA 91109. RP CHEN, JS (reprint author), CALTECH,PASADENA,CA 91125, USA. RI Chen, Jen-Sue/A-3298-2015 NR 24 TC 11 Z9 11 U1 0 U2 2 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 15 PY 1993 VL 236 IS 1-2 BP 72 EP 76 DI 10.1016/0040-6090(93)90645-6 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA MM810 UT WOS:A1993MM81000014 ER PT J AU JAWORSKE, DA AF JAWORSKE, DA TI THERMAL MODELING OF A CALORIMETRIC TECHNIQUE FOR MEASURING THE EMITTANCE OF SURFACES AND COATINGS SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 20th International Conference on Metallurgical Coatings and Thin Films CY APR 19-23, 1993 CL SAN DIEGO, CA AB A finite element analysis model of a transient technique used to measure the emittance of surfaces and coatings was developed and used to estimate the uncertainty in emittance. The dimensions used in the model matched the dimensions used in the design of a low temperature calorimetric vacuum emissometer being built to characterize the thermal properties of space power materials in the temperature range 173-673 K. Radiant energy from a quartz halogen lamp impinged on an aluminum sample that was coated with a thermal control coating and suspended in a liquid-nitrogen-cooled vacuum chamber by narrow gauge thermocouple wires. After removing the heat source, the temperature of the sample was monitored vs, time and the temperature-time curve was used to calculate the emittance. Factors contributing to the uncertainty in the emittance included uncertainties in time, temperature, area of the sample, heat capacity of the sample and heat loss from the uncoated back side of the sample. Heat losses from the thermocouple wires were found to be negligible. The total probable error in the emittance obtained from the low temperature calorimetric vacuum emissometer design was estimated to be less than 4% for emittance values greater than 0.5 at temperatures between 173 and 673 K. RP JAWORSKE, DA (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 15 TC 8 Z9 8 U1 0 U2 2 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 15 PY 1993 VL 236 IS 1-2 BP 146 EP 152 DI 10.1016/0040-6090(93)90660-H PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA MM810 UT WOS:A1993MM81000029 ER PT J AU KOLAWA, E SUN, X REID, JS CHEN, JS NICOLET, MA RUIZ, R AF KOLAWA, E SUN, X REID, JS CHEN, JS NICOLET, MA RUIZ, R TI AMORPHOUS W40RE40B20 DIFFUSION-BARRIERS FOR [SI]/AL AND [SI]/CU METALLIZATIONS SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 20th International Conference on Metallurgical Coatings and Thin Films CY APR 19-23, 1993 CL SAN DIEGO, CA ID ALLOYS; SI; ALUMINUM; SILICON; FILMS; AL; TEMPERATURE; STABILITY AB The performance of W40Re40B20 metallic amorphous thin firm alloys as diffusion barriers between monocrystalline silicon substrates ((Si)) and aluminum or copper overlayers is reported. The films are deposited using d.c. and r.f. magnetron co-sputtering. Their crystallization temperature and resistivity are about 900 degrees C and 200 mu Omega cm, respectively. The (Si)/W40Re40B20/Al and (Si)/W40Re40B20/Cu metallizations were vacuum-annealed at different temperatures for 30 min and characterized by He-4 backscattering spectrometry, X-ray diffraction, scanning electron microscopy in combination with energy-dispersive analysis of X-rays, and electrical measurements on shallow junction diodes. The (Si)/W40Re40B20/Al structure was stable up to 500 degrees C and failed at 550 degrees C due to chemical reactions between the barrier and aluminum. A formation of cracks in the bilayer (Si)/W(40)R(40)B(20)/Cu structure is responsible for its failure at 600 degrees C. The results demonstrate that it is fruitless to raise the crystallization temperature of an amorphous metallic him if its ability to react with the adjacent materials is not suppressed as well. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP KOLAWA, E (reprint author), CALTECH,PASADENA,CA 91125, USA. RI Chen, Jen-Sue/A-3298-2015 NR 25 TC 13 Z9 13 U1 0 U2 2 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 15 PY 1993 VL 236 IS 1-2 BP 301 EP 305 DI 10.1016/0040-6090(93)90686-J PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA MM810 UT WOS:A1993MM81000055 ER PT J AU REID, JS KOLAWA, E RUIZ, RP NICOLET, MA AF REID, JS KOLAWA, E RUIZ, RP NICOLET, MA TI EVALUATION OF AMORPHOUS (MO, TA, W)-SI-N DIFFUSION-BARRIERS FOR [SI]/CU METALLIZATIONS SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 20th International Conference on Metallurgical Coatings and Thin Films CY APR 19-23, 1993 CL SAN DIEGO, CA ID TANTALUM AB Amorphous binary M(=Mo, Ta or W)-Si and ternary M-Si-N, r.f.-sputtered from M,Si, and WSi2, targets, are assessed as diffusion barriers between silicon substrates and copper overlayers. By I(V) tests of the metallizations on n(+)p shallow junction diodes, the ternary M-Si-N barriers prevent copper from reaching the silicon at 800 degrees C or higher during a 30 min heat treatment in vacuum. Failure of the metallizations correlates with the crystallization temperature of the barrier, which is presumably a prelude to fast grain-boundary diffusion. Metal-rich Mo-Si-N and W-Si-N barriers liberate nitrogen during annealing, which poses a limitation to their crystallization temperatures. No reaction products of copper with metal-rich M-Si or M-Si-N barriers are observed, which is in agreement with our recent thermodynamic modelling of the M-Si-Cu ternary systems. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP REID, JS (reprint author), CALTECH,PASADENA,CA 91125, USA. NR 17 TC 158 Z9 160 U1 1 U2 12 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 15 PY 1993 VL 236 IS 1-2 BP 319 EP 324 DI 10.1016/0040-6090(93)90689-M PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA MM810 UT WOS:A1993MM81000058 ER PT J AU HOOD, LL MCPETERS, RD MCCORMACK, JP FLYNN, LE HOLLANDSWORTH, SM GLEASON, JF AF HOOD, LL MCPETERS, RD MCCORMACK, JP FLYNN, LE HOLLANDSWORTH, SM GLEASON, JF TI ALTITUDE DEPENDENCE OF STRATOSPHERIC OZONE TRENDS BASED ON NIMBUS-7 SBUV DATA SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TOMS DATA; SAGE-I; LATITUDE AB A multiple regression statistical model is applied to estimate the altitude, latitude, and seasonal dependences of stratospheric ozone trends using 11.5 years of Nimbus 7 SBUV data for the period November 1978 to June 1990. In the upper stratosphere, the derived trends agree in both latitude dependence and approximate amplitude with published predictions from stratospheric models that consider gas-phase chemical processes together with the observed approximately 0.1 ppbV per year increase in tropospheric chlorine. The dominant contribution to column ozone trends occurs in the lower stratosphere where significant negative trends are present at latitudes >200 in both hemispheres. The observed latitude dependence is qualitatively consistent with model predictions that include the effects of heterogeneous chemical ozone losses on lower stratospheric aerosols. C1 NASA,GODDARD SPACE FLIGHT CTR,GSFC,GREENBELT,MD 20771. SCA,LANHAM,MD 20706. ARC,LANDOVER,MD 20785. UNIV ARIZONA,DEPT ATMOSPHER SCI,TUCSON,AZ 85721. RP HOOD, LL (reprint author), UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721, USA. RI Flynn, Lawrence/B-6321-2009; Gleason, James/E-1421-2012; McPeters, Richard/G-4955-2013; OI Flynn, Lawrence/0000-0001-6856-2614; McPeters, Richard/0000-0002-8926-8462; McCormack, John/0000-0002-3674-0508 NR 21 TC 36 Z9 36 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 14 PY 1993 VL 20 IS 23 BP 2667 EP 2670 DI 10.1029/93GL03087 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MP205 UT WOS:A1993MP20500023 ER PT J AU LAHOZ, WA CARR, ES FROIDEVAUX, L HARWOOD, RS KUMER, JB MERGENTHALER, JL PECKHAM, GE READ, WG RICAUD, PD ROCHE, AE WATERS, JW AF LAHOZ, WA CARR, ES FROIDEVAUX, L HARWOOD, RS KUMER, JB MERGENTHALER, JL PECKHAM, GE READ, WG RICAUD, PD ROCHE, AE WATERS, JW TI NORTHERN-HEMISPHERE MID-STRATOSPHERE VORTEX PROCESSES DIAGNOSED FROM H2O, N2O AND POTENTIAL VORTICITY SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRACER; WINTER; OZONE; MODEL AB MLS H2O, CLAES N2O and potential vorticity calculated from UK Meteorological Office data are used to study mid-stratospheric vortex processes in the northern hemisphere winter of 1991-92. Areas of moist air (at approximately 20 hPa) and N2O-poor air (at approximately 10 hPa) are well-correlated with high values of potential vorticity and there is little or no large scale mixing across the vortex edge. We find evidence for the descent of relatively dry mesospheric air to the 840 K (approximately 10 hPa) level, as well as descent of moist air from the upper stratosphere to the 655 K (approximately 20 hPa) level. A reduction in the areas of the vortex and both the moist and N2O-poor regions is observed and there is evidence of moist and N2O-poor air parcels being extruded from the vortex. C1 JET PROP LAB,PASADENA,CA 91109. HERIOT WATT UNIV,DEPT PHYS,EDINBURGH EH14 4AS,MIDLOTHIAN,SCOTLAND. LOCKHEED PALO ALTO RES LABS,PALO ALTO,CA 94304. RP LAHOZ, WA (reprint author), UNIV EDINBURGH,DEPT METEOROL,EDINBURGH EH9 3JZ,MIDLOTHIAN,SCOTLAND. NR 20 TC 16 Z9 17 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 14 PY 1993 VL 20 IS 23 BP 2671 EP 2674 DI 10.1029/93GL02475 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MP205 UT WOS:A1993MP20500024 ER PT J AU LECACHEUX, A ZARKA, P DESCH, MD EVANS, DR AF LECACHEUX, A ZARKA, P DESCH, MD EVANS, DR TI THE SIDEREAL ROTATION PERIOD OF NEPTUNE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EMISSION AB The two main, low frequency radio components discovered at Neptune by the Planetary Radio Astronomy experiment carried aboard Voyager 2 have a well defined periodicity at about 16.1 hour. By analyzing all the available data, i.e. about 60 days around the closest approach for the ''Burst'' component and 15 days for the ''Smooth'' component, we determine, for each component, die best estimate of the radio period. We conclude that the two estimates are not statistically different. While the two kinds of radio emissions have very different characteristics (in particular their frequency ranges and beaming properties), and probably correspond to different emission processes, their modulation is very likely due to the rotation of the planetary magnetic field tied to the core of the planet, as it has already been assumed for the other giant planets. The deduced estimate of the sidereal rotation period of Neptune is 16.108 +/- 0.006 (or 16h06.5m +/- 00.4m). C1 NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. RADIOPHYS INC,BOULDER,CO 80301. RP LECACHEUX, A (reprint author), OBSERV PARIS,F-92195 MEUDON,FRANCE. NR 7 TC 9 Z9 9 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 14 PY 1993 VL 20 IS 23 BP 2711 EP 2714 DI 10.1029/93GL03117 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MP205 UT WOS:A1993MP20500034 ER PT J AU THEIS, RF BRACE, LH AF THEIS, RF BRACE, LH TI SOLAR-CYCLE VARIATIONS OF ELECTRON-DENSITY AND TEMPERATURE IN THE VENUSIAN NIGHTSIDE IONOSPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAINTENANCE AB The return of periapsis to low altitudes during the Summer and Fall of 1992 provided a unique opportunity for the Pioneer Venus Orbiter (PVO) to make in situ measurements in the Venusian ionosphere at much lower levels of solar activity (F10.7 almost-equal-to 120) than existed when periapsis was at low altitudes in 1979 and 1980 (F10.7 almost-equal-to 220). We present the observations of electron density (N(e)) and temperature (T(e)) made by the Orbiter Electron Temperature Probe (OETP) during the Entry Period. Empirical models of the N(e) and T(e) height variations are presented and compared with similar models based on OETP measurements made at solar maximum. The median Ne at the ionospheric peak (approximately 140 lan) was essentially unchanged from its solar maximum value, but the ionosphere was increasingly depleted at higher altitudes, reaching a factor of 7 lower densities at 200 km. T(e) was lower by almost a factor of 2 at 140 km but was rather significantly enhanced at higher altitudes; exceeding its solar maximum values by a factor of 1.3 at 200 km and a factor of 2 at 500 km. In general these results support the earlier conclusions that the nightside upper ionosphere is depleted at lower levels of solar activity by a reduction of the nightward ion flow. The lack of Ne variation near the peak (between solar maximum and entry) suggests that nightward ion transport does not play as large a role in the peak formation as does local ion production by energetic particles. The decrease in T(e) at low altitudes suggests that the low densities of the upper ionosphere at the time of PVO entry could no longer support the conduction of heat from the dayside ionosphere, thus allowing the lower nightside ionosphere to cool by collisions with ions and neutrals, and by heat conduction to die cooler regions below. C1 UNIV MICHIGAN,SPACE PHYS RES LAB,ANN ARBOR,MI 48109. RP THEIS, RF (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,CODE 910,GREENBELT,MD 20771, USA. NR 11 TC 12 Z9 12 U1 1 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 14 PY 1993 VL 20 IS 23 BP 2719 EP 2722 DI 10.1029/93GL02485 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MP205 UT WOS:A1993MP20500036 ER PT J AU GREBOWSKY, JM HARTLE, RE KAR, J CLOUTIER, PA TAYLOR, HA BRACE, LH AF GREBOWSKY, JM HARTLE, RE KAR, J CLOUTIER, PA TAYLOR, HA BRACE, LH TI ION MEASUREMENTS DURING PIONEER VENUS REENTRY - IMPLICATIONS FOR SOLAR-CYCLE VARIATION OF ION COMPOSITION AND DYNAMICS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NIGHTSIDE IONOSPHERE; PRECIPITATION AB During the final, low solar activity phase of the Pioneer Venus mission, the Orbiter Ion Mass Spectrometer measurements found all ion species, in the midnight-dusk sector, reduced in concentration relative to that observed at solar maximum. Molecular ion species comprised a greater part of the total ion concentration as O+ and H+ had the greatest depletions. The nightside ionospheric states were strikingly similar to the isolated solar maximum ''disappearing'' ionospheres. Both are very dynamic states characterized by a rapidly drifting plasma and 30-100 eV superthermal O+ ions. C1 TAYLOR ENTERPRISES,BEAVER RIVER B5A 4A5,NS,CANADA. RICE UNIV,DEPT PHYS & ASTRON,HOUSTON,TX 77251. UNIV MICHIGAN,ANN ARBOR,MI 48109. RP GREBOWSKY, JM (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 914,GREENBELT,MD 20771, USA. RI Grebowsky, Joseph/I-7185-2013 NR 14 TC 11 Z9 11 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 14 PY 1993 VL 20 IS 23 BP 2735 EP 2738 DI 10.1029/93GL02239 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MP205 UT WOS:A1993MP20500040 ER PT J AU KASPRZAK, WT NIEMANN, HB HEDIN, AE BOUGHER, SW HUNTEN, DM AF KASPRZAK, WT NIEMANN, HB HEDIN, AE BOUGHER, SW HUNTEN, DM TI NEUTRAL COMPOSITION MEASUREMENTS BY THE PIONEER VENUS NEUTRAL MASS-SPECTROMETER DURING ORBITER REENTRY SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GENERAL-CIRCULATION; THERMOSPHERE; MODEL AB Measurements by the Pioneer Venus Orbiter Neutral Mass Spectrometer (ONMS) instrument during Orbiter re-entry have been made from 18-24 hours local solar time, above 170 km, of He, and from midnight to 4.5 hours below 200 lan of He, N, O, CO, N2, and CO2. Preliminary results indicate that in the post-midnight sector He is the dominant species above 170 km, O the dominant species from 140-170 km and CO2 the dominant species below 140 km. Estimated scale height temperatures for He, O and CO2 of about 105-120 K are similar to those observed in 1978-80 at higher solar activity. The densities at 1 am local solar time and at 150 km are within 35% of those measured earlier. The He bulge is also similar to that observed in 1978-80 confirming that thermosphere superrotation is still present. Comparison with the results of a Venus Thermosphere General Circulation Model suggests the nightside is not sensitive to changes in solar activity due to the isolation of the day and night thermospheres. Apparently, the relatively small changes in die dayside thermosphere with solar activity have little impact on the nightside thermosphere. C1 UNIV ARIZONA,DEPT PLANETARY SCI,LUNAR & PLANETARY LAB,TUCSON,AZ 85721. RP KASPRZAK, WT (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. RI Bougher, Stephen/C-1913-2013 OI Bougher, Stephen/0000-0002-4178-2729 NR 12 TC 17 Z9 17 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 14 PY 1993 VL 20 IS 23 BP 2747 EP 2750 DI 10.1029/93GL02241 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MP205 UT WOS:A1993MP20500043 ER PT J AU KEATING, GM HSU, NC AF KEATING, GM HSU, NC TI THE VENUS ATMOSPHERIC RESPONSE TO SOLAR-CYCLE VARIATIONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID THERMAL STRUCTURE; THERMOSPHERE; MESOSPHERE; TEMPERATURE AB Atmospheric drag measurements from the orbital decay of the Pioneer Venus Orbiter and Magellan spacecraft have recently been obtained of the Venus dayside and nightside atmosphere between 130 and 210 km during a period of low solar activity. These new measurements, combined with the earlier Pioneer Venus drag measurements (1978-80) obtained near the maximum of the 11-year solar cycle, have allowed the detection of the detailed response of temperature, atomic oxygen and carbon dioxide to solar variations. We have found a weak but detectable temperature response on the dayside which is in accord with the response predicted by Keating and Bougher when they assumed very strong CO2 radiative cooling resulting from atomic oxygen exciting CO2 into 15 micron emission. This same radiative process may cause strong cooling in the Earth's upper atmosphere with the doubling of CO2 in the future. With decreasing solar activity, the O/CO2 ratio in the lower thermosphere is found to decrease, apparently due to decreased photodissociation of CO2 and lower temperatures. The percent decrease in atomic oxygen with decreasing solar activity on the dayside is found to be approximately the same as the percent decreases of atomic oxygen transported to the nightside. A very weak response of nightside temperatures to solar activity variations has also been detected. C1 SCI APPLICAT INT CORP,HAMPTON,VA 23666. RP KEATING, GM (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,MAIL STOP 401B,HAMPTON,VA 23681, USA. RI Hsu, N. Christina/H-3420-2013 NR 13 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 14 PY 1993 VL 20 IS 23 BP 2751 EP 2754 DI 10.1029/93GL03010 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MP205 UT WOS:A1993MP20500044 ER PT J AU KASPRZAK, WT NIEMANN, HB HEDIN, AE BOUGHER, SW AF KASPRZAK, WT NIEMANN, HB HEDIN, AE BOUGHER, SW TI WAVE-LIKE PERTURBATIONS OBSERVED AT LOW ALTITUDES BY THE PIONEER VENUS ORBITER NEUTRAL MASS-SPECTROMETER DURING ORBITER ENTRY SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID UPPER-ATMOSPHERE; GENERAL-CIRCULATION; GRAVITY-WAVE; THERMOSPHERE; MESOSPHERE; MODEL AB Wave-like perturbations have been observed in the nightside neutral density data acquired for He, N, O, N2 and CO2 by the Pioneer Venus Orbiter Neutral Mass Spectrometer (ONMS) during entry in late 1992. The data cover an altitude range of 133-200 km from 0.5-4.5 hours local solar time and occur at medium solar activity (F10.7=120). The perturbations, with an effective wavelength along the orbit of about 100 to 600 km, have similar amplitudes for the various species and helium is out of phase with respect to the heavier mass species. The measurements are comparable to those observed in 1978-80 at solar maximum activity (F10.7=200) above 145 km. Between 133 and 160 km the rms amplitudes grow with altitude at a rate of about (1.6, 2.1, 2.7, 4.4) x 10(-3) km-1 for N, O, N2, and CO2, respectively. The average rms amplitudes above 145 km of 0.08 for N and 0 and 0.1 for N2 are comparable in magnitude to those observed in the earlier 1978-80 data of 0.06, 0.08 and 0.095 respectively. CO2 is an exception for which the entry value is 0.17 compared to 0.09 earlier. By combining the two overlapping data sets there is a suggestion that the CO2 amplitudes grow in value with altitude up to about 140-170 km and then decrease in amplitude. Like the earlier data, the entry data are consistent with die interpretation that the neutral density perturbations are due to gravity waves propagating upward from the lower thermosphere. Earlier data sampled a higher altitude region where dissipation is important in limiting and ultimately reversing the growth of gravity waves while the lower altitude entry data probed the region where growth of these waves can be observed. C1 UNIV ARIZONA,DEPT PLANETARY SCI,LUNAR & PLANETARY LAB,TUCSON,AZ 85721. RP KASPRZAK, WT (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. RI Bougher, Stephen/C-1913-2013 OI Bougher, Stephen/0000-0002-4178-2729 NR 16 TC 15 Z9 15 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 14 PY 1993 VL 20 IS 23 BP 2755 EP 2758 DI 10.1029/93GL02628 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MP205 UT WOS:A1993MP20500045 ER PT J AU INTRILLIGATOR, DS HARTLE, RE PEREZDETEJADA, H SISCOE, GL AF INTRILLIGATOR, DS HARTLE, RE PEREZDETEJADA, H SISCOE, GL TI INITIAL PVO EVIDENCE OF ELECTRON DEPLETION SIGNATURES DOWNSTREAM OF VENUS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PLASMA ANALYZER EXPERIMENT AB This first analysis of Pioneer Venus Orbiter (PVO) plasma analyzer electron measurements obtained in early 1992 during the PVO entry phase of the mission indicates the presence downstream from the terminator of a depletion or ''bite out'' of energetic ionosheath electrons similar to that observed on Mariner 10. There is more than one possible explanation for this energetic electron depletion. If it is due to atmospheric scattering, the electrons traveling along draped magnetic lux tubes that thread through the Venus neutral atmosphere would lose energy from impact ionization with oxygen. The cross-section for such electron impact ionization of oxygen has a peak near 100 eV, and it remains high above this energy, so atmospheric loss could provide a natural process for electrons at these energies to be selectively removed. In this case, our results are consistent with the Kar et al. (1994) study of PVO atmospheric entry ion mass spectrometer data, which indicates that electron impact plays a significant role in maintaining the nightside ionosphere. Although it is appealing to interpret the energetic electron depletion in terms of direct atmospheric scattering, alternatively it could result from strong draping which connects the depletion region magnetically to the weak downstream bow shock and thereby reduces the electron source strength. C1 UNIV NACL AUTONOMA MEXICO,INST GEOFIS,ENSENADA,BAJA CALIFORNIA,MEXICO. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP INTRILLIGATOR, DS (reprint author), CARMEL RES CTR,POB 1732,SANTA MONICA,CA 90406, USA. NR 7 TC 1 Z9 1 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 14 PY 1993 VL 20 IS 23 BP 2779 EP 2782 DI 10.1029/93GL02483 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MP205 UT WOS:A1993MP20500051 ER PT J AU SHIH, S JUNG, KH YAN, J KWONG, DL KOVAR, M WHITE, JM GEORGE, T KIM, S AF SHIH, S JUNG, KH YAN, J KWONG, DL KOVAR, M WHITE, JM GEORGE, T KIM, S TI PHOTOINDUCED LUMINESCENCE ENHANCEMENT FROM ANODICALLY OXIDIZED POROUS SI SO APPLIED PHYSICS LETTERS LA English DT Article ID INDUCED DEGRADATION; SILICON; PHOTOLUMINESCENCE; INTENSITY AB We have investigated the phenomenon of photoluminescence (PL) increase in anodically oxidized porous Si with increasing laser illumination time. by transmission Fourier transform infrared spectroscopy (FTIR), PL spectroscopy, and electron paramagnetic resonance. The adsorption of oxygen without hydrogen loss was observed during laser illumination by FTIR. The PL intensity increased linearly, while the dangling bond (DB) density decreased with increasing illumination time. By assuming that the decrease of DB density has a linear response to the illumination time, we identify that the change in DB density is mainly responsible for the observed PL increase after laser illumination. C1 UNIV TEXAS,DEPT CHEM & BIOCHEM,AUSTIN,TX 78712. JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109. RP SHIH, S (reprint author), UNIV TEXAS,DEPT ELECT & COMP ENGN,MICROELECTR RES CTR,AUSTIN,TX 78712, USA. NR 21 TC 29 Z9 30 U1 0 U2 2 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 13 PY 1993 VL 63 IS 24 BP 3306 EP 3308 DI 10.1063/1.110182 PG 3 WC Physics, Applied SC Physics GA MN375 UT WOS:A1993MN37500019 ER PT J AU KOGUT, A LINEWEAVER, C SMOOT, GF BENNETT, CL BANDAY, A BOGGESS, NW CHENG, ES DEAMICI, G FIXSEN, DJ HINSHAW, G JACKSON, PD JANSSEN, M KEEGSTRA, P LOEWENSTEIN, K LUBIN, P MATHER, JC TENORIO, L WEISS, R WILKINSON, DT WRIGHT, EL AF KOGUT, A LINEWEAVER, C SMOOT, GF BENNETT, CL BANDAY, A BOGGESS, NW CHENG, ES DEAMICI, G FIXSEN, DJ HINSHAW, G JACKSON, PD JANSSEN, M KEEGSTRA, P LOEWENSTEIN, K LUBIN, P MATHER, JC TENORIO, L WEISS, R WILKINSON, DT WRIGHT, EL TI DIPOLE ANISOTROPY IN THE COBE DIFFERENTIAL MICROWAVE RADIOMETERS 1ST-YEAR SKY MAPS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC MICROWAVE BACKGROUND; COSMOLOGY; OBSERVATIONS ID COSMIC BACKGROUND-RADIATION; LARGE-SCALE ANISOTROPY; LOCAL GROUP; GALAXIES; FLUCTUATIONS; UNIVERSE; DESIGN; MOTION AB We present a determination of the cosmic microwave background dipole amplitude and direction from the COBE Differential Microwave Radiometers (DMR) first year of data. Data from the six DMR channels are consistent with a Doppler-shifted Planck function of dipole amplitude DELTAT = 3.365 +/- 0.027 mK toward direction (l(II), b(II)) = (264.4-degrees +/- 0.3-degrees, 48.4-degrees +/- 0.5-degrees). The implied velocity of the Local Group with respect to the CMB rest frame is v(LG) = 627 +/- 22 km s-1 toward (l(II), b(II)) = (276-degrees +/- 3-degrees, 30-degrees +/- 3-degrees). DMR has also mapped the dipole anisotropy resulting from the Earth's orbital motion about the Solar system barycenter, yielding a measurement of the monopole CMB temperature T0 at 31.5, 53, and 90 GHz, T0 = 2.75 +/- 0.05 K. C1 NASA, GSFC, APPL RES CORP, GREENBELT, MD 20771 USA. NASA, GSFC, HUGHES STX CORP, GREENBELT, MD 20771 USA. UCSB, DEPT PHYS, SANTA BARBARA, CA 93106 USA. UNIV CALIF LOS ANGELES, DEPT ASTRON, LOS ANGELES, CA 90024 USA. PRINCETON UNIV, DEPT PHYS, PRINCETON, NJ 08544 USA. LAWRENCE BERKELEY LAB, SPACE SCI LAB, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, CTR PARTICLE ASTROPHYS, BERKELEY, CA 94720 USA. JET PROP LAB, PASADENA, CA 91109 USA. MIT, DEPT PHYS, CAMBRIDGE, MA 02139 USA. RP KOGUT, A (reprint author), NASA, GSFC, UNIV SPACE RES ASSOC, CODE 685 9, GREENBEL, MD 20771 USA. RI Kogut, Alan/D-6293-2012 NR 36 TC 249 Z9 251 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 1993 VL 419 IS 1 BP 1 EP 6 DI 10.1086/173453 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK864 UT WOS:A1993MK86400001 ER PT J AU MIYAJI, T MUSHOTZKY, RF LOEWENSTEIN, M SERLEMITSOS, PJ MARSHALL, FE PETRE, R JAHODA, KM BOLDT, EA HOLT, SS SWANK, J SZYMKOWIAK, AE KELLEY, R AF MIYAJI, T MUSHOTZKY, RF LOEWENSTEIN, M SERLEMITSOS, PJ MARSHALL, FE PETRE, R JAHODA, KM BOLDT, EA HOLT, SS SWANK, J SZYMKOWIAK, AE KELLEY, R TI SPATIALLY-RESOLVED X-RAY SPECTROSCOPY OF THE MERGING GALAXY CLUSTER-A2256 SO ASTROPHYSICAL JOURNAL LA English DT Article DE COOLING FLOWS; GALAXIES, CLUSTERS, INDIVIDUAL (A2256); GALAXIES, INTERACTIONS; INTERGALACTIC MEDIUM; X-RAYS, GALAXIES ID COOLING FLOWS; CROSS-SECTIONS; COMA CLUSTER; A2256; MORPHOLOGY; EMISSION; EINSTEIN; SPECTRUM; MATTER; MASS AB The cluster of galaxies A2256 was observed with BBXRT (Broad Band X-ray Telescope) during the Astro 1 mission with a total exposure of approximately 4000 s. Moderate resolution spectra of parts of this cluster of galaxies give information complementary to the high spatial resolution observation of the same cluster by ROSAT. ROSAT spectral images (Briel et al.) have shown evidence of a merger with the northwest clump being cooler than the main cluster body. The BBXRT spectra also show an indication of a lower temperature [kT = 4.6(+0.9, -0.7) keV, 90% confidence errors] in the same general area. The BBXRT data from other regions within 10' from the center show temperatures (T approximately 7 keV) consistent with the Ginga overall average and constrain the temperature gradient by limiting the polytropic index to gamma = 1.10 +/- 0.35 (90% confidence errors). We have detected absorption in excess of the galactic value in several regions of the cluster, similar to that seen in other clusters with the Einstein SSS. One of the observed regions shows an apparent oxygen edge absorption feature at 0.54 less than or equal to E(edge) less than or equal to 0.62 keV with an edge optical depth of the order of unity. This range of edge energy corresponds to absorption by oxygen with ionization stage between O2+ and O4+. This suggests the existence of about 10(12)-10(13) M. of warm (T approximately 0.5-5 x 10(5) K) absorbing gas. It is unlikely that this component has its origin in the hot intracluster gas, compressed by the shock waves generated in the cluster merging and subsequently cooled, because the cooling timescale of the postshock gas is too large. It may have originated from the cold ps in the subcluster cooling flow heated up by shock waves or ionized by radiation sources. Using spatially resolved temperature information and absolute fluxes from the BBXRT data, along with core radius and the beta-parameter of the modified King profile from the ROSAT PSPC data, we have obtained radial mass profiles of the X-ray emitting gas and the total gravitational mass. At r approximately 0.8 h50(-1) Mpc, the binding mass range is approximately 2.8-3.7 x 10(14) M. for a range of models consistent with the BBXRT spectral data. This gives a total mass within approximately 0.8 Mpc of about 5 times the mass of X-ray emitting gas. The total mass and gas fraction of the inner 1 Mpc of the cluster are very similar to those of the Coma Cluster. C1 UNIV SPACE RES ASSOC,GREENBELT,MD. UNIV MARYLAND,DEPT ASTRON,COLL PK,MD 20742. RP MIYAJI, T (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS,GREENBELT,MD 20771, USA. RI Swank, Jean/F-2693-2012; Kelley, Richard/K-4474-2012 NR 44 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 10 PY 1993 VL 419 IS 1 BP 66 EP 77 DI 10.1086/173459 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK864 UT WOS:A1993MK86400007 ER PT J AU TURNER, TJ NANDRA, K GEORGE, IM FABIAN, AC POUNDS, KA AF TURNER, TJ NANDRA, K GEORGE, IM FABIAN, AC POUNDS, KA TI X-RAY OBSERVATIONS OF THE WARM ABSORBER IN NGC-3783 SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES; INDIVIDUAL (NGC-3783); GALAXIES; SEYFERT; X-RAYS; GALAXIES ID SEYFERT-GALAXIES; SPECTRAL VARIABILITY; ACTIVE GALAXIES; EMISSION-LINE; COLD MATTER; NGC 3783; ABSORPTION; SENSITIVITY; MCG-6-30-15; REFLECTION AB We present a high signal-to-noise ROSAT position sensitive proportional counter (PSPC) observation of the Seyfert 1 galaxy NGC 3783. The 0.1-2.5 keV spectrum shows strong evidence for an absorption edge most likely associated with O VII-VIII. Such a feature, which has now been detected in a number of PSPC spectra (Nandra et al.; Nandra & Pounds; Turner et al.), is the signature of highly ionized material the so-called warm absorber, in the line of sight to the X-ray source. The result is strongly supported by analysis of previously unpublished Ginga data and reanalysis of a 1985 EXOSAT observation of NGC 3783. We show that the warm absorber is plausibly located at a radius less than or similar to 10(18) cm from the X-ray source, possibly in an outflowing wind. C1 UNIV SPACE RES ASSOC,GREENBELT,MD. INST ASTRON,CAMBRIDGE CB3 OHA,ENGLAND. UNIV LEICESTER,DEPT PHYS & ASTRON,LEICESTER LE1 7RH,ENGLAND. RP TURNER, TJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS,GREENBELT,MD 20771, USA. NR 35 TC 79 Z9 79 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 1993 VL 419 IS 1 BP 127 EP 135 DI 10.1086/173466 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK864 UT WOS:A1993MK86400014 ER PT J AU ADELMAN, SJ COWLEY, CR LECKRONE, DS ROBY, SW WAHLGREN, GM AF ADELMAN, SJ COWLEY, CR LECKRONE, DS ROBY, SW WAHLGREN, GM TI THE ABUNDANCES OF THE ELEMENTS IN SHARP-LINED EARLY-TYPE STARS FROM IUE HIGH-DISPERSION SPECTROGRAMS .1. CR, MN, FE, NI, AND CO SO ASTROPHYSICAL JOURNAL LA English DT Article DE STARS, ABUNDANCES; STARS, EARLY-TYPE; STARS, PECULIAR; ULTRAVIOLET, STARS ID ASTROPHYSICAL-OBSERVATORY SPECTROGRAMS; COADDED DAO SPECTROGRAMS; HERCULIS; SPECTRA; PEGASI; CANCRI AB The current study was undertaken to test the viability of IUE archives as a source of information elemental species unavailable from (ground-based) coude spectra. The first step in this endeavor is to check the consistency of abundances obtained from IUE material and those derived from the ground especially as reported in a series of papers by Adelman and coworkers. In this paper we examine the Cr, Mn, Fe, Ni, and Co abundances derived from co-added IUE high-dispersion LWP or LWR spectrograms of four HgMn stars and five normal main-sequence B and A stars. This material represents a significant improvement over that obtainable directly from the IUE archives. We also find good agreement with two independent model atmosphere and synthesis codes: Kurucz's SYNTHE and programs developed at the University of Michigan. For the iron group, we find good (approximately less-than-or-equal-to 0.2 dex) agreement between UV and optical determinations. We are optimistic that the IUE archives may be usefully exploited for abundance work, especially for elements unavailable in ground-based spectra. C1 UNIV MICHIGAN,DEPT ASTRON,ANN ARBOR,MI 48109. NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. SUNY COLL OSWEGO,DEPT EARTH SCI,OSWEGO,NY 13126. UNIV MICHIGAN,DEPT PHYS & ASTRON,ANN ARBOR,MI 48109. NASA,GODDARD SPACE FLIGHT CTR,COMP SCI CORP,ASTRON PROGRAM,GREENBELT,MD 20771. RP ADELMAN, SJ (reprint author), THE CITADEL,DEPT PHYS,CHARLESTON,SC 29409, USA. NR 22 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 10 PY 1993 VL 419 IS 1 BP 276 EP 285 DI 10.1086/173481 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK864 UT WOS:A1993MK86400029 ER PT J AU MARSHALL, FE MUSHOTZKY, RF PETRE, R SERLEMITSOS, PJ AF MARSHALL, FE MUSHOTZKY, RF PETRE, R SERLEMITSOS, PJ TI THE X-RAY-SPECTRUM OF CYGNUS X-1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCRETION, ACCRETION DISKS; STARS, INDIVIDUAL (CYGNUS-X-1); X-RAYS, STARS ID ACTIVE GALACTIC NUCLEI; COLD MATTER; HDE 226868; LINE; BINARIES; SPECTROPHOTOMETRY; FLUORESCENCE; REFLECTION; GALAXIES; DISK AB The first moderate-resolution (FWHM approximately 160 eV) X-ray spectrum of a galactic black hole candidate in the 1-11 keV band has been obtained with the BBXRT experiment aboard Astro 1. There is a broad excess of flux in the 6-7 keV band above a simple power-law continuum which is consistent with that expected from reflection of the observed continuum from a disk of neutral material surrounding the central source. The edge at 7.1 keV due to photoelectric absorption by neutral Fe is deeper than that predicted for material of solar abundances, which suggests an overabundance of Fe in the source. There is little evidence for any emission features due to Fe with the possible exception of a narrow line at 6.4 keV with an equivalent width of 13 +/- 11 eV. Previous, lower resolution observations and subsequent model calculations suggested that the excess flux in the Fe K band emission seen from Cyg X-1 is produced by fluorescence from a relativistic accretion disk around the black hole. The upper limits for representative models of this kind are about 60 eV, which is a factor of about 2 lower than predictions. Pronounced intensity dips were seen, especially at low energies, during the 1251 s observation. These events are modeled as variations in the material absorbing an unchanging continuum shape. As reported by previous observers, the flux at the lowest energies is more than that predicted by a simple model of variation in the absorbing column. Several more complicated models, including one in which the low-energy excess is caused by dust scattering in the interstellar medium, are consistent with the data. The absorption during the intervals outside the dips is 5.8 x 10(21) hydrogen atoms cm-2, which is consistent with estimates based on optical and UV measurements. RP MARSHALL, FE (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. NR 36 TC 34 Z9 34 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 1993 VL 419 IS 1 BP 301 EP 310 DI 10.1086/173484 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK864 UT WOS:A1993MK86400032 ER PT J AU CANNIZZO, JK AF CANNIZZO, JK TI THE ACCRETION DISK LIMIT-CYCLE MODEL - TOWARD AN UNDERSTANDING OF THE LONG-TERM BEHAVIOR OF SS-CYGNI SO ASTROPHYSICAL JOURNAL LA English DT Article DE ACCRETION, ACCRETION DISKS; NOVAE, CATACLYSMIC VARIABLES; STARS, INDIVIDUAL (SS-CYGNI) ID DWARF-NOVA OUTBURSTS; MAGNETIC NEUTRON STARS; ACTIVE GALACTIC NUCLEI; CATACLYSMIC VARIABLES; INSTABILITY MODEL; THERMAL-INSTABILITY; VERTICAL STRUCTURE; BINARY-SYSTEMS; VISCOUS DISKS; WHITE-DWARF AB We present detailed computations of the limit cycle model for dwarf nova outbursts with application to Cygni the best studied dwarf nova. We examine how secular changes in the input parameters of the model affect the properties associated with the outbursts. For input parameters which reproduce the observed outburst recurrence times and outburst durations for SS Cyg, our time-dependent, accretion disk instability code generates light curves in which one or more short outbursts tend to be sandwiched between two long outbursts. We find that the relative frequency of long versus short outbursts can be influenced by changes in the accretion disk viscosity and mass transfer rate. By forming moving averages taken from the long-term AAVSO light curve of SS Cyg, we find a strong correlation between the recurrence time for outbursts t(c) and the ratio of the number of long outbursts N(L) to the number of short outbursts N(S) occurring in a given time interval. This can be accounted for in the model in several ways. Changes in the radius of the inner edge of the disk produce correlated changes in t(c) and N(L)/N(S), as do slow variations in either alpha(cold) or alpha(hot) - the accretion disk viscosity parameters in quiescence and outburst. In this latter scenario, there must be a fundamental asymmetry between the two alphas in the sense that both quantities cannot be varying in step with each other-i.e., one must remain fixed while the other varies. Finally, variations in the mass transfer rate M(T) cannot directly account for the observed long-term changes in the light curve of SS Cyg as was postulated by Hempelmann & Kurths and by Cannizzo & Mattei. RP CANNIZZO, JK (reprint author), NASA,GSFC,ASTRON & SOLAR PHYS LAB,CODE 681,GREENBELT,MD 20771, USA. NR 62 TC 153 Z9 153 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 1993 VL 419 IS 1 BP 318 EP 336 DI 10.1086/173486 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK864 UT WOS:A1993MK86400034 ER PT J AU PHILLIPS, KJH HARRA, LK KEENAN, FP ZARRO, DM WILSON, M AF PHILLIPS, KJH HARRA, LK KEENAN, FP ZARRO, DM WILSON, M TI HELIUM-LIKE ARGON LINE EMISSION IN SOLAR-FLARES SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATOMIC DATA; ATOMIC PROCESSES; SUN, ABUNDANCES; SUN, FLARES; SUN, X-RAYS, GAMMA-RAYS ID DIELECTRONIC SATELLITE SPECTRA; X-RAY-SPECTRA; EXCITATION RATES; MAXIMUM-MISSION; INNER-SHELL; IONS; TRANSITIONS; ABUNDANCES; RATIOS; SUN AB Theoretical X-ray spectra of Ar XVII lines and Ar XVI satellites at approximately 4 angstrom, derived from R-matrix code and other calculations, are compared with solar-flare observations obtained with the SMM Flat Crystal Spectrometer. There is good agreement between the observed line features and those in the theoretical spectra, and the comparison leads to best-fit values of electron temperature for the observed solar flares. We present wavelengths for the Ar XVII and some Ar XVI lines, measured from the observed spectra, which have better precision than previous values. In addition, the coronal Ar/S abundance is determined from the relative intensities of Ar XVII lines to those of nearby S XV transitions, and the value of this ratio is discussed in the light of previous work. C1 NASA,GODDARD SPACE FLIGHT CTR,APPL RES CORP,GREENBELT,MD 20771. QUEENS UNIV BELFAST,DEPT PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. UNIV LONDON ROYAL HOLLOWAY & BEDFORD NEW COLL,DEPT PHYS,EGHAM TW20 0EX,SURREY,ENGLAND. RP PHILLIPS, KJH (reprint author), RUTHERFORD APPLETON LAB,DIV ASTROPHYS,DIDCOT OX11 0QX,OXON,ENGLAND. OI Harra, Louise/0000-0001-9457-6200 NR 26 TC 12 Z9 12 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 1993 VL 419 IS 1 BP 426 EP 431 DI 10.1086/173495 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK864 UT WOS:A1993MK86400043 ER PT J AU BAUSCHLICHER, CW PARTRIDGE, H AF BAUSCHLICHER, CW PARTRIDGE, H TI THE VIBRATIONAL FREQUENCIES OF CH2OH SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GAUSSIAN-BASIS SETS; ELECTRON CORRELATION; MOLECULES; ATOMS AB On the basis of the comparison of the experimental and calculated vibrational frequencies of CH3OH and CH2OH, it is concluded that the band observed by Jacox at 569 cm-1 is due to the CH2 rock in CH2OH. Calculations, using a second-order Moller-Plesset perturbation theory and a coupled-cluster singles and doubles approach including a perturbational estimate of the triple excitations, show that this mode is more sensitive to basis set than the other modes. Agreement with experiment is obtained only when very large basis sets are used. RP BAUSCHLICHER, CW (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NR 15 TC 16 Z9 16 U1 0 U2 2 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 10 PY 1993 VL 215 IS 5 BP 451 EP 454 DI 10.1016/0009-2614(93)85701-O PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA MK611 UT WOS:A1993MK61100006 ER PT J AU DONNELLAN, A HAGER, BH KING, RW HERRING, TA AF DONNELLAN, A HAGER, BH KING, RW HERRING, TA TI GEODETIC MEASUREMENT OF DEFORMATION IN THE VENTURA-BASIN-REGION, SOUTHERN CALIFORNIA SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID WESTERN TRANSVERSE RANGES; INTERFEROMETRY; EARTHQUAKES; CHANNEL; FAULT; MODEL AB We have measured the deformation in the Ventura basin region, southern California, with Global Positioning System (GPS) measurements carried out over 4.6 years between 1987 and 1992. The deformation within our network is spatially variable on scales of tens of kilometers, with strain rates reaching 0.6 +/- 1 murad/yr in the east-central basin. Blocklike rotations are observed south and northwest of the basin where the maximum shear strain rates are an order of magnitude lower (0.06 +/- 1 murad/yr to the south). We also observed clockwise rotations of 1-degrees-7-degrees/m.y. Shear strain rates determined by comparing angle changes from historical triangulation spanning several decades and GPS measurements give consistent, though less precise, results. The geodetic rates of shortening across the basin and Western Transverse Ranges are lower than those estimated from geological observations, but the patterns of deformation from the two methods agree qualitatively. C1 MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP DONNELLAN, A (reprint author), JET PROP LAB,MS 238-625,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 39 TC 54 Z9 55 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-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1993 VL 98 IS B12 BP 21727 EP 21739 DI 10.1029/93JB02766 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ML693 UT WOS:A1993ML69300004 ER PT J AU AVOUAC, JP PELTZER, G AF AVOUAC, JP PELTZER, G TI ACTIVE TECTONICS IN SOUTHERN-XINJIANG, CHINA - ANALYSIS OF TERRACE RISER AND NORMAL-FAULT SCARP DEGRADATION ALONG THE HOTAN-QIRA FAULT SYSTEM SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID TIEN-SHAN; CENOZOIC TECTONICS; GRAVITY-ANOMALIES; LARGE EARTHQUAKES; WESTERN TIBET; ASIA; AGES; PARAMETERS; SHORELINE; LANDFORMS AB The northern piedmont of the western Kunlun mountains (Xinjian-, China) is marked at its easternmost extremity, south of the Hotan-Qira oases, by a set of normal faults trending N50E for nearly 70 km. Conspicuous on Landsat and SPOT images, these faults follow the southeastern border of a deep flexural basin and may be related to the subsidence of the Tarim platform loaded by the western Kunlun northward overthrust. The Hotan-Qira normal fault system vertically offsets the piedmont slope by 70 m. Highest fault scarps reach 20 m and often display evidence for recent reactivations about 2 m high. Successive stream entrenchments in uplifted footwalls have formed inset terraces. We have leveled topographic profiles across fault scarps and transverse abandoned terrace risers. The state of degradation of each terrace edge has been characterized by a degradation coefficient tau, derived by comparison with analytical erosion models. Edges of highest abandoned terraces yield a degradation coefficient of 33+/-4 m2. Profiles of cumulative fault scarps have been analyzed in a similar way using synthetic profiles generated with a simple incremental fault scarp model. The analysis shows that (1) rate of fault slip remained essentially constant since the aggradation of the piedmont surface and (2) the occurrence of inset terraces was synchronous at all studied sites, suggesting a climate-driven terrace formation. Observation of glacial and periglacial geomorphic features along the northern front of the western Kunlun range indicates that the Qira glaciofluvial fan emplaced after the last glacial maximum, during the retreat of the Kunlun glaciers (12-22 ka). The age of the most developed inset terrace in uplifted valleys is inferred to be 10+/-3 ka, coeval with humid climate pulses of the last deglaciation. The mass diffusivity constant (k=tau/T, T being time B.P.) in the Hotan region is determined to be 3.3+/-1.4 m2/10(3) years, consistent with other estimates in similar climatic and geologic environments of western China. These results imply a minimum rate for the Tarim subsidence of 3.5+/-2 mm/yr. If Western Kunlun overthrusts the Tarim platform on a crustal ramp dipping 40-degrees-45-degrees to the south, it would absorb at least 4.5+/-3 mm/yr of convergence between western Tibet and Tarim. C1 INST PHYS GLOBE STRASBOURG, F-67084 STRASBOURG, FRANCE. JET PROP LAB, PASADENA, CA 91109 USA. OBSERV MIDI PYRENEES, TOULOUSE, FRANCE. RI Avouac, Jean-Philippe/B-5699-2015 OI Avouac, Jean-Philippe/0000-0002-3060-8442 NR 41 TC 73 Z9 77 U1 1 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1993 VL 98 IS B12 BP 21773 EP 21807 DI 10.1029/93JB02172 PG 35 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ML693 UT WOS:A1993ML69300006 ER PT J AU FREUND, F FREUND, MM BATLLO, F AF FREUND, F FREUND, MM BATLLO, F TI CRITICAL-REVIEW OF ELECTRICAL-CONDUCTIVITY MEASUREMENTS AND CHARGE-DISTRIBUTION ANALYSIS OF MAGNESIUM-OXIDE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID THERMAL-DECOMPOSITION; SINGLE-CRYSTALS; MGO; HYDROXIDE; MINERALS; TRACES; HOLES; WATER; CAO AB The electrical conductivity sigma of MgO single crystals shows a sharp increase at 500-800-degrees-C, in particular of sigma(surface), generally attributed to surface contamination. Charge Distribution Analysis (CDA), a new technique providing information on fundamental properties that was previously unavailable, allows for the determination of surface charges, their sign and associated internal electric field. Data on 99.99% purity, arc-fusion grown MgO crystals show that mobile charge carriers start to appear in the bulk of the MgO crystals between 200 and 400-degrees-C when sigma (measured by conventional techniques) is in the 10(-14) to 10(-16) OMEGA-1 cm-1 range. Above 500-degrees-C, as sigma increases to 10(-6) to 10(-7) OMEGA-1 cm-1. More charges appear giving rise to a strong positive surface charge supported by a strong internal field. This indicates that charges are generated in the bulk and diffuse to the surface by an internally controlled process. On the basis of their positive sign they are identified as holes (defect electrons). Because of the low cation content of these very pure MgO crystals, these holes cannot be associated with transition metal impurities. Instead, they are associated with the O2- sublattice, e.g. consist of O- states or positive holes. This conclusion is supported by magnetic susceptibility data showing the appearance of 1000 +/- 500 ppm paramagnetic species between 200-500-degrees-C. The magnetic data are consistent with strongly coupled, diamagnetic O- pairs below 200-500-degrees-C, chemically equivalent to peroxy anions, O-(2)2-, and probably associated with cation vacancies in the MgO matrix. The formation of O2 in arc-fusion grown MgO crystals is very unexpected because of the highly reducing growth conditions. Their presence implies an internal redox reaction involving dissolved ''water'' by which OH- pairs convert to O-(2)2- plus H2 molecules. This redox conversion is supported by mass spectroscopic measurements of the H2 release from highly OH--doped doped, finely divided MgO and by wet-chemical analysis of its oxidant concentration. C1 SWISS FED INST TECHNOL, DEPT PHYS, CH-8092 ZURICH, SWITZERLAND. NASA, AMES RES CTR, SETI INST, MOFFETT FIELD, CA 94035 USA. UNIV BOURGOGNE, REACTIVITE SOLIDES LAB, DIJON, FRANCE. RP FREUND, F (reprint author), SAN JOSE STATE UNIV, DEPT PHYS, SAN JOSE, CA 94192 USA. NR 54 TC 21 Z9 21 U1 2 U2 12 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 1993 VL 98 IS B12 BP 22209 EP 22229 DI 10.1029/93JB01327 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ML693 UT WOS:A1993ML69300036 ER PT J AU BROWN, LL CAFFALL, NM GOLOMBEK, MP AF BROWN, LL CAFFALL, NM GOLOMBEK, MP TI PALEOMAGNETISM AND TECTONIC INTERPRETATIONS OF THE TAOS-PLATEAU-VOLCANIC-FIELD, RIO-GRANDE-RIFT, NEW-MEXICO SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID WESTERN UNITED-STATES; NORTHERN NEW-MEXICO; ESPANOLA BASIN; SECULAR VARIATION; EVOLUTION; STRESS; ROTATIONS; AGES AB The tectonic response of the Taos Plateau volcanic field in the southern San Luis basin to the late stage extensional environment of the Rio Grande rift was investigated using paleomagnetic techniques. Sixty-two sites (533 samples) of Pliocene volcanic units were collected covering four major rock types with ages of 4.7 to 1.8 Ma. Twenty-two of these sites were from stratigraphic sections of the lower, middle and upper Servilleta Basalt collected in the Rio Grande gorge at two locations 19 km apart. Flows from the lower and middle members in the southern gorge record reversed polarities, while those in Garapata Canyon are normal with an excursion event in the middle of the sequence. The uppermost flows of the upper member at both sites display normal directions. Although these sections correlate chemically, they seem to represent different magnetic time periods during the Gilbert Reversed-Polarity Chron. Alternating field demagnetization, aided by principal component analysis, yields 55 sites with stable directions representing both normal and reversed polarities, and five sites indicating transitional fields. Mean direction of the normal and inverted reversed sites is I = 49.3-degrees and D = 356.7-degrees (a95 = 3.6-degrees). Angular dispersion of the virtual geomagnetic poles is 16.3-degrees, which is consistent with paleosecular variation model G, fit to data from the past 5 m.y. Comparison with the expected direction indicates no azimuthal rotation of the Taos Plateau volcanic field; inclination flattening for the southern part of the plateau is 8.3-degrees +/- 5.3-degrees. Previous paleomagnetic data indicate 10-degrees-15-degrees counterclockwise rotation of the Espanola block to the south over the past 5 m.y. The data suggest the Taos Plateau volcanic field, showing no rotation and some flattening in the south and east, has acted as a stable buttress and has been downwarped by overriding of the southeastern end of the plateau by the Picuris Mountains, which make up the northern corner of the counterclockwise rotating Espanola block. C1 JET PROP LAB,DIV EARTH & SPACE SCI,PASADENA,CA 91109. RP BROWN, LL (reprint author), UNIV MASSACHUSETTS,DEPT GEOL & GEOG,AMHERST,MA 01003, USA. NR 46 TC 2 Z9 2 U1 1 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD DEC 10 PY 1993 VL 98 IS B12 BP 22401 EP 22413 DI 10.1029/93JB01823 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ML693 UT WOS:A1993ML69300049 ER PT J AU THOM, R MOORE, L SPROUL, WD CHANG, TP AF THOM, R MOORE, L SPROUL, WD CHANG, TP TI ROLLING-CONTACT FATIGUE TESTS OF REACTIVELY SPUTTERED NITRIDE COATINGS OF TI, ZR, HF, CR, MO, TI-AL, TI-ZR AND TI-AL-V ON 440C STAINLESS-STEEL SUBSTRATES SO SURFACE & COATINGS TECHNOLOGY LA English DT Article AB Eight different nitride coatings-TiN, ZrN, HfN, CrN, Mo2N, Ti0.5Al0.5N, Ti0.5Zr0.5N and (Ti-Al-V)N (from the aircraft alloy Ti-6wt.%Al-4wt.%V)-were deposited by reactive, unbalanced magnetron sputtering onto hardened (RC 60) 440C stainless steel specimens for rolling contact fatigue (RCF) tests. Four different coating thicknesses, i.e. 0.25, 0.50, 0.75 and 1.0 mum, of each type of coating were deposited on 440C test rods 9.5 mm in diameter and 75 mm long. The RCF tests were carried out under atmospheric conditions in a lubricated three-ball-on-one-rod test machine at two different stresses of 4.0 and 5.4 GPa. Six of the eight coatings gave significant improvements in RCF life, whereas only CrN and Ti0.5Al0.5N showed little or no improvement over that of an uncoated specimen. The best improvement was for the HN coating 0.5 mum thick at both the hertzian stresses of 4.0 and 5.4 GPa, which gave an increase in RCF life of 13 and 12 times over that of an uncoated specimen respectively. The coating thickness is critical in improving the RCF life and, in general for these coatings, the optimum thickness is in the range 0.5-0.75 mum. C1 NORTHWESTERN UNIV, BIRL, 1801 MAPLE AVE, EVANSTON, IL 60201 USA. NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, HUNTSVILLE, AL 35812 USA. NR 14 TC 21 Z9 21 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 10 PY 1993 VL 62 IS 1-3 BP 423 EP 427 DI 10.1016/0257-8972(93)90278-V PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA MN812 UT WOS:A1993MN81200013 ER PT J AU BENOY, PA DELLACORTE, C AF BENOY, PA DELLACORTE, C TI TRIBOLOGICAL CHARACTERISTICS OF SPUTTERED AU/CR FILMS ON ALUMINA SUBSTRATES AT ELEVATED-TEMPERATURES SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 20th International Conference on Metallurgical Coatings and Thin Films CY APR 19-23, 1993 CL SAN DIEGO, CA ID ASSISTED DEPOSITION; SILVER FILMS; CERAMICS; WEAR; FRICTION AB This paper describes research to evaluate the tribological properties of alumina pins sliding against thin sputtered gold films on alumina disk substrates. A chromium interlayer 250 angstrom thick was first deposited on the alumina test disks to enhance the adhesion and high temperature wetting of the gold films. The Au/Cr films were tribotested in pure sliding in a pin-on-disk tribometer under a load of 4.9 N at 1 m s-1. The test atmosphere was room air at temperatures of 25, 500 and 800-degrees-C and the test duration varied from 60 to 540 min. The use of the Au/Cr films reduced the friction by about a factor of 2 compared with the unlubricated alumina sliding couple. The coatings prevented wear of the alumina substrate disks and reduced the pin wear by one to two orders of magnitude. In addition, wear lives in excess of 200 000 sliding passes (9 h) were observed during sliding at 800-degrees-C. The results suggest that these films show promise for the lubrication of many high temperature sliding components. C1 NATL AERONAUT & SPACE ADM,LEWIS RES CTR,MS 23-2,21000 BROOKPARK RD,CLEVELAND,OH 44135. ST LOUIS UNIV,PARKS COLL,CAHOKIA,IL 62206. NR 15 TC 4 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 10 PY 1993 VL 62 IS 1-3 BP 454 EP 459 DI 10.1016/0257-8972(93)90283-T PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA MN812 UT WOS:A1993MN81200018 ER PT J AU WU, RLC MIYOSHI, K KORENYIBOTH, AL GARSCADDEN, A BARNES, PN AF WU, RLC MIYOSHI, K KORENYIBOTH, AL GARSCADDEN, A BARNES, PN TI ION-IMPLANTED DIAMOND FILMS AND THEIR TRIBOLOGICAL PROPERTIES SO SURFACE & COATINGS TECHNOLOGY LA English DT Article ID FRICTION; COATINGS AB This paper reports the physical characterization and tribological evaluation of ion-implanted diamond films. Diamond films were produced by microwave plasma, chemical vapor deposition technique. Diamond films with various grain sizes (0.3 and 3 mum) and roughness (9.1 and 92.1 nm r.m.s. respectively) were implanted with C+ (m/e = 12) at an ion energy of 160 eV and a fluence of 6.72 x 10(17) ions cm-2. Unidirectional sliding friction experiments were conducted in ultrahigh vacuum (6.6 x 10(-7) Pa), dry nitrogen and humid air (40% RH) environments. The effects of C+ ion bombardment on fine and coarse-grained diamond films are as follows: the surface morphology of the diamond films did not change; the surface roughness increased (16.3 and 135.3 nm r.m.s.); the diamond structures were damaged and formed a thin layer of amorphous non-diamond carbon; the friction coefficients dramatically decreased in the ultrahigh vacuum (0.1 and 0.4); the friction coefficients decreased slightly in the dry nitrogen and humid air environments. C1 NASA, LEWIS RES CTR, CLEVELAND, OH 44135 USA. CALSPAN CORP, CLEVELAND, OH 44135 USA. WRIGHT PATTERSON AIR FORCE BASE, DAYTON, OH 45433 USA. RP UES INC, 4401 DAYTON XENIA RD, DAYTON, OH 45432 USA. NR 17 TC 10 Z9 10 U1 0 U2 1 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 10 PY 1993 VL 62 IS 1-3 BP 589 EP 594 DI 10.1016/0257-8972(93)90304-7 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA MN812 UT WOS:A1993MN81200039 ER PT J AU REDDY, CJ ITTIPIBOON, A CUHACI, M AF REDDY, CJ ITTIPIBOON, A CUHACI, M TI APERTURE-COUPLED MICROSTRIP PATCH ANTENNA FED BY NONRADIATING DIELECTRIC WAVE-GUIDE SO ELECTRONICS LETTERS LA English DT Article DE MICROSTRIP ANTENNAS; ANTENNA FEEDERS; DIELECTRIC WAVE-GUIDES AB Owing to its low loss property at millimetre-wave frequencies, the nonradiating dielectric (NRD) waveguide is very attractive for use as a feed network in planar arrays. In the Letter, the design, fabrication and testing of a microstrip patch antenna fed by NRD guide at X-band is described. Radiation patterns are measured and presented. C1 COMMUN RES CTR,OTTAWA K2H 8S2,ONTARIO,CANADA. RP REDDY, CJ (reprint author), NASA,LANGLEY RES CTR,MAILSTOP 490,HAMPTON,VA 23681, USA. NR 5 TC 2 Z9 2 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD DEC 9 PY 1993 VL 29 IS 25 BP 2157 EP 2158 DI 10.1049/el:19931447 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA MP751 UT WOS:A1993MP75100001 ER PT J AU JAFFE, RL SMITH, GD YOON, DY AF JAFFE, RL SMITH, GD YOON, DY TI CONFORMATIONS OF 1,2-DIMETHOXYETHANE FROM AB-INITIO ELECTRONIC-STRUCTURE CALCULATIONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAS-PHASE; FIELD; ENERGIES; 1,2-DIFLUOROETHANE; POLY(OXYETHYLENE); MOLECULES; ETHERS; ORIGIN; BONDS AB The conformational properties of 1,2-dimethoxyethane (DME) have been analyzed in detail using ab initio electronic structure calculations in order to better understand the influence of oxygen gauche effects on the conformation energies and populations of DME. Our calculations indicate that the energy of the gauche conformation of the O-C-C-O bond relative to the trans conformation, which reflects the strength of the oxygen gauche effect in DME, depends strongly not only on the basis set size but also on electron correlation effects. Specifically, the energy of the tgt conformation of DME relative to the ttt conformation was determined for various basis sets at both the SCF and MP2 levels. MP2 level calculations with a D95+(2dfp) basis set, a Dunning double-zeta basis set of the form (10s6p2d1f/4s1p)/[5s2p2d1f/2s1p], yield an energy of ca.0.1 kcal/mol for the gauche conformation, as compared with 0.75 kcal/mol for MP2 level calculations with the smaller D95** basis set and 1.0 kcal/mol for SCF level calculations employing the D95+(2dfp) basis set. A salient result of our investigation is the determination that the energy of the tg+/-g-/+ conformation lies only ca. 0.2 kcal/mol above that of the ttt conformation, apparently due to strong O...H attractions. Finally, we find that the conformer populations of DME obtained from conformational energies determined at the MP2 level with a D95+(2dfp) basis set are in good agreement with those derived from electron diffraction experiments and can be used to successfully reproduce experimental values of NMR vicinal coupling constants and dipole moments for DME. C1 ELORET INST, SUNNYVALE, CA 94087 USA. IBM CORP, ALMADEN RES CTR, SAN JOSE, CA 95120 USA. RP JAFFE, RL (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NR 32 TC 136 Z9 136 U1 1 U2 6 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 DEC 9 PY 1993 VL 97 IS 49 BP 12745 EP 12751 DI 10.1021/j100151a020 PG 7 WC Chemistry, Physical SC Chemistry GA ML667 UT WOS:A1993ML66700020 ER PT J AU SMITH, GD JAFFE, RL YOON, DY AF SMITH, GD JAFFE, RL YOON, DY TI A FORCE-FIELD FOR SIMULATIONS OF 1,2-DIMETHOXYETHANE AND POLY(OXYETHYLENE) BASED UPON AB-INITIO ELECTRONIC-STRUCTURE CALCULATIONS ON MODEL MOLECULES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAS-PHASE; CONFORMATION; ETHERS AB The force field parameters for simulations of 1,2-dimethoxyethane (DME) and poly(oxyethylene) were determined mainly utilizing the geometries and energies of the conformational minima and low-lying barriers in DME and diethyl ether (DEE) as determined from ab initio electronic structure calculations. A set of partial atomic charges, used to describe electrostatic interactions, was parameterized based upon the dipole moment and the partial atomic charges for DEE as determined from ab initio electronic structure calculations. The force field parameters thus determined reproduce well the experimental second virial coefficients of gas-phase DEE vs temperature. Furthermore, a stochastic dynamics simulation of DME based on our force field leads to an electron diffraction radial distribution function in good agreement with experiment. Detailed comparison of the electron diffraction radial distribution function as a function of conformer distribution with experiment corroborates the previous finding of Astrup that the order of conformer populations in DME is tg+/-g-+ > tgt > ttt. C1 IBM CORP,ALMADEN RES CTR,650 HARRY RD,SAN JOSE,CA 95120. ELORET INST,SUNNYVALE,CA 94087. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 17 TC 141 Z9 141 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 9 PY 1993 VL 97 IS 49 BP 12752 EP 12759 DI 10.1021/j100151a021 PG 8 WC Chemistry, Physical SC Chemistry GA ML667 UT WOS:A1993ML66700021 ER PT J AU CHU, LT LEU, MT KEYSER, LF AF CHU, LT LEU, MT KEYSER, LF TI HETEROGENEOUS REACTIONS OF HOCL+HCL-]CL2+H2O AND CLONO2+HCL-]CL2+HNO3 ON ICE SURFACES AT POLAR STRATOSPHERIC CONDITIONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID NITRIC-ACID TRIHYDRATE; HYDROGEN-CHLORIDE; VAPOR-PRESSURES; HCL; NITRATE; SOLUBILITY; CHEMISTRY; STICKING; CLONO2; CLOUDS AB Heterogeneous reactions of HOCl + HCl --> Cl2 + H2O (1) and ClONO2 + HCl - Cl2 + HNO3 (2) on ice surfaces at a temperature of 188 K have been investigated in a flow reactor interfaced with a differentially pumped quadrupole mass spectrometer. Partial pressures for HOCl and ClONO2 in the range of 6.5 X 10(-8)-2.0 x 10(-6) Torr, which mimic conditions in the polar stratosphere, have been used. Uptake of HCI on ice surfaces using partial pressures of HCI in the range of 1.8 X 10(-7)-8.0 x 10(-6) Torr has been measured prior to contact with HOCl or ClONO2. Pseudo-first-order decays of HOCl and ClONO2 over HCl-coated ice surfaces have been observed in all experiments under the conditions of P(HOCl) < P(HCl) and P(ClONO2) < P(HCl) used. Both the decay rates of HOCl and ClONO2 and the growth rates of Cl2 have been used to obtain reaction probabilities: gamma(g) (1) = 0.34 +/- 0.20 (1sigma) and gamma(g) (2) = 0.27 +/- 0.19 (1sigma) if we assume that the area of ice surfaces is equal to the geometric area of the flow-tube reactor. The results are in good agreement with previous measurements. By considering the morphology of ice films, we obtain true reaction probabilities gamma(t)(1) = 0.13 +/- 0.08 and gamma(t)(2) = 0.10 +/- 0.08 using a previously published model of surface reaction and pore diffusion. In addition, the true reaction probability, gamma(t) (3), for the ClONO2 + H2O --> HOCl + HNO3 (3) reaction has been measured to be greater than 0.03 on ice surfaces. Reaction mechanisms for these heterogeneous reactions 1-3 are discussed, including a possible two-step mechanism for reaction 2 in terms of reaction 3 and reaction 1. C1 JET PROP LAB,DIV EARTH & SPACE SCI,PASADENA,CA 91109. NR 32 TC 92 Z9 92 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD DEC 9 PY 1993 VL 97 IS 49 BP 12798 EP 12804 DI 10.1021/j100151a028 PG 7 WC Chemistry, Physical SC Chemistry GA ML667 UT WOS:A1993ML66700028 ER PT J AU WOO, R GAZIS, P AF WOO, R GAZIS, P TI LARGE-SCALE SOLAR-WIND STRUCTURE NEAR THE SUN DETECTED BY DOPPLER SCINTILLATION SO NATURE LA English DT Article AB STUDIES of the solar wind in the inner heliosphere (between the solar-wind source surface at approximately 0.01 AU and 0.3 AU are hampered by the lack of in situ spacecraft measurements. Radio propagation measurements-using both natural1-7 and spacecraft8-14 radio signals-have provided many insights, but information on large-scale solar-wind structure inside 0.3 AU that can be related to coronal features or direct spacecraft measurements at larger distances has nevertheless remained elusive. Here we report the detection of solar-wind structure between 0.08 and 0.53 AU, based on the response of the 13-cm radio signals from the Pioneer Venus Orbiter to electron-density fluctuations and solar-wind speed within this region. These Doppler scintillation measurements were made during the late declining phase of the most recent cycle of solar activity, when the solar wind exhibited recurrent high-speed streams. Near 0.5 AU, we find narrow regions of enhanced scintillation which appear to be associated with compressed plasma at the leading edges of these streams, consistent with previous scintillation measurements15,16. Inside 0.2 AU, however, scintillation enhancements are conspicuously absent from the fast streams, and instead occur in regions where the average solar wind is slow. They exhibit high variability, and appear to be the interplanetary manifestation of coronal mass ejections. The plasma structures giving rise to these enhanced scintillations apparently undergo significant evolution inside 0.3 AU. C1 NASA, AMES RES CTR, SAN JOSE STATE UNIV FDN, MOFFETT FIELD, CA 94035 USA. RP WOO, R (reprint author), JET PROP LAB, PASADENA, CA 91109 USA. NR 41 TC 19 Z9 19 U1 0 U2 0 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 9 PY 1993 VL 366 IS 6455 BP 543 EP 545 DI 10.1038/366543a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ML218 UT WOS:A1993ML21800062 ER PT J AU THAKOOR, S AF THAKOOR, S TI HIGH-SPEED OPTOELECTRONIC RESPONSE FROM THE EDGES OF LEAD-ZIRCONATE-TITANATE THIN-FILM CAPACITORS SO APPLIED PHYSICS LETTERS LA English DT Article AB This letter reports on a high speed (approximately 10 ns), nondestructive, polarization-dependent photoresponse from lead zirconate titanate (PZT) thin films, when illuminated with lambda = 532 nm, at approximately mW/mum2 of incident optical power. This photoresponse emerges primarily from the edges of the sandwich ferroelectric capacitors, consisting of PZT films with predominant c-axis orientation. This response, in contrast with the thermally triggered effect, is unipolar in nature and occurs at an order of magnitude lower power level, and therefore offers a greater application potential. Its dependence on the crystal orientation and remanent polarization in the PZT film, and therefore its ability to track the built-in E fields within the film, may offer such photoresponse as a high speed nondestructive evaluation tool. RP THAKOOR, S (reprint author), JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109, USA. NR 17 TC 10 Z9 10 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 6 PY 1993 VL 63 IS 23 BP 3233 EP 3235 DI 10.1063/1.110208 PG 3 WC Physics, Applied SC Physics GA ML096 UT WOS:A1993ML09600043 ER PT J AU WU, TK AF WU, TK TI LOW-COST L-BAND MOBILE TERMINAL ANTENNAS FOR HELICOPTERS SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE MOBILE COMMUNICATIONS; HELICOPTER SATELLITE COMMUNICATIONS; MOBILE COMMUNICATION ANTENNAS AB The feasibility of using a low-gain antenna (LGA) as a mobile terminal antenna for helicopers is described in this article. The objectives are (a) to select the lowest cost antenna system which can be easily mounted on a helicopter and capable of communicating with a satellite, and (b) to determine the best antenna position on the helicopter to mitigate the signal blockage due to rotor blades and the multipath effect from the ehlicopter's body. The omnidirectional low gain antenna (LGA) is selected because it is simple, reliable, and low cost. The helix antenna is selected among the many LGAs because it is the most economical and has the widest elevation beam-width. Both two- and four-arm helices are studied experimentally to determine the antenna's performance and the scattering effects from the helicopter's body. It is found that the LGA should be located near the tail section and at least 8 in. above the helicopter. (C) 1993 John Wiley & Sons, Inc. RP WU, TK (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0895-2477 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD DEC 5 PY 1993 VL 6 IS 15 BP 846 EP 850 DI 10.1002/mop.4650061507 PG 5 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA MG740 UT WOS:A1993MG74000006 ER PT J AU GOLDSTEIN, RM ENGELHARDT, H KAMB, B FROLICH, RM AF GOLDSTEIN, RM ENGELHARDT, H KAMB, B FROLICH, RM TI SATELLITE RADAR INTERFEROMETRY FOR MONITORING ICE-SHEET MOTION - APPLICATION TO AN ANTARCTIC ICE STREAM SO SCIENCE LA English DT Article ID GROUNDING LINES; VELOCITY; CURRENTS; SHELF; FIELD AB Satellite radar interferometry (SRI) provides a sensitive means of monitoring the flow velocities and grounding-line positions of ice streams, which are indicators of response of the ice sheets to climatic change or internal instability. The detection limit is about 1.5 millimeters for vertical motions and about 4 millimeters for horizontal motions in the radar beam direction. The grounding line, detected by tidal motions where the ice goes afloat, can be mapped at a resolution of approximately 0.5 kilometer. The SRI velocities and grounding line of the Rutford Ice Stream, Antarctica, agree fairly well with earlier ground-based data. The combined use of SRI and other satellite methods is expected to provide data that will enhance the understanding of ice stream mechanics and help make possible the prediction of ice sheet behavior. C1 BRITISH ANTARCTIC SURVEY,CAMBRIDGE CB3 0ET,ENGLAND. CALTECH,DIV GEOL & PLANETARY SCI,PASADENA,CA 91125. RP GOLDSTEIN, RM (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 45 TC 336 Z9 370 U1 7 U2 47 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 3 PY 1993 VL 262 IS 5139 BP 1525 EP 1530 DI 10.1126/science.262.5139.1525 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MK329 UT WOS:A1993MK32900028 PM 17829380 ER PT J AU FAHNESTOCK, M BINDSCHADLER, R KWOK, R JEZEK, K AF FAHNESTOCK, M BINDSCHADLER, R KWOK, R JEZEK, K TI GREENLAND ICE-SHEET SURFACE-PROPERTIES AND ICE DYNAMICS FROM ERS-1 SAR IMAGERY SO SCIENCE LA English DT Article AB C-band synthetic aperture radar (SAR) imagery from the European Space Agency's ERS-1 satellite reveals the basic zonation of the surface of the Greenland Ice Sheet. The zones have backscatter signatures related to the structure of the snowpack, which varies with the balance of accumulation and melt at various elevations. The boundaries of zones can be accurately located with the use of this high-resolution imagery. The images also reveal a large flow feature in northeast Greenland that is similar to ice streams in Antarctica and may play a major role in the discharge of ice from the ice sheet. C1 OHIO STATE UNIV,BYRD POLAR RES CTR,COLUMBUS,OH 43210. CALTECH,PASADENA,CA 91109. RP FAHNESTOCK, M (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. RI Kwok, Ron/A-9762-2008; Fahnestock, Mark/N-2678-2013 OI Kwok, Ron/0000-0003-4051-5896; NR 10 TC 132 Z9 133 U1 1 U2 16 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD DEC 3 PY 1993 VL 262 IS 5139 BP 1530 EP 1534 DI 10.1126/science.262.5139.1530 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MK329 UT WOS:A1993MK32900029 PM 17829381 ER PT J AU VANSNYDER, W AF VANSNYDER, W TI ALGORITHM-723 - FRESNEL INTEGRALS SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Note DE SPECIAL FUNCTIONS AB An implementation of approximations for Fresnel integrals and associated functions is described. The approximations were originally developed by W. J. Cody, but a Fortran implementation using them has not previously been published. RP VANSNYDER, W (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MAIL STOP 601-108,PASADENA,CA 91109, USA. NR 8 TC 3 Z9 3 U1 0 U2 0 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 1993 VL 19 IS 4 BP 452 EP 456 DI 10.1145/168173.168193 PG 5 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA MR970 UT WOS:A1993MR97000002 ER PT J AU HARRIS, LA RECK, GM AMBRUS, JH HEMMERLY, RA AF HARRIS, LA RECK, GM AMBRUS, JH HEMMERLY, RA TI NASA IN-SPACE TECHNOLOGY EXPERIMENTS PROGRAM - STATUS AND PLANS SO ACTA ASTRONAUTICA LA English DT Article AB Experience with the Shuttle and free-flying satellites as technology test beds has shown the feasibility and desirability of using space assets as facilities for technology development. Thus, by the time the space station era arrives, technologists will be ready for an accessible engineering facility in space. Along with the scientific and commercial space development communities, the technology development community has been participating in defining requirements for this in-space facility. As the 21st century is approached, it is expected that many flights to the Space Station Freedom will carry one or more RT&E experiments. The experiments are likely to utilize both the pressurized volume, and the external payload attachment facilities. Based on the success of instrumenting the Shuttle itself to obtain ascent and descent aerothermodynamic data a unique, but extremely important, class of experiments will use the space station itself as an experimental vehicle. RP HARRIS, LA (reprint author), NASA,OFF AERONAUT EXPLORAT & TECHNOL,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD DEC PY 1993 VL 29 IS 12 BP 931 EP 944 DI 10.1016/0094-5765(93)90013-M PG 14 WC Engineering, Aerospace SC Engineering GA MY865 UT WOS:A1993MY86500005 ER PT J AU BANKS, BA AF BANKS, BA TI MODIFY SURFACES WITH IONS AND ARCS SO ADVANCED MATERIALS & PROCESSES LA English DT Article RP BANKS, BA (reprint author), NASA,LEWIS RES CTR,ELECTROPHYS BRANCH,21000 BROOK PK RD,CLEVELAND,OH 44135, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 0026-0665 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD DEC PY 1993 VL 144 IS 6 BP 22 EP 25 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA MN004 UT WOS:A1993MN00400003 ER PT J AU NOURBAKHSH, I MORSE, S BECKER, C BALABANOVIC, M GAT, E SIMMONS, R GOODRIDGE, S POTLAPALLI, H HINKLE, D JUNG, K VANVACTOR, D AF NOURBAKHSH, I MORSE, S BECKER, C BALABANOVIC, M GAT, E SIMMONS, R GOODRIDGE, S POTLAPALLI, H HINKLE, D JUNG, K VANVACTOR, D TI THE WINNING ROBOTS FROM THE 1993 ROBOT COMPETITION SO AI MAGAZINE LA English DT Editorial Material AB The second annual Robot Competition and Exhibition sponsored by the American Association for Artificial Intelligence was held in Washington D.C. on 13-15 July 1993 in conjunction with the Eleventh National Conference on Artificial Intelligence, This article describes the robots that placed first and second in each event and com pares their strategies and their resulting successes and difficulties. C1 CALTECH,JET PROP LAB,DEPT MECH ENGN,PASADENA,CA 91125. CARNEGIE MELLON UNIV,DEPT COMP SCI,PITTSBURGH,PA 15213. CARNEGIE MELLON UNIV,INST ROBOT,PITTSBURGH,PA 15213. N CAROLINA STATE UNIV,DEPT ELECT & COMP ENGN,RALEIGH,NC 27695. LOCKHEED PALO ALTO RES LABS,CTR ARTIFICIAL INTELLIGENCE,PALO ALTO,CA. RP NOURBAKHSH, I (reprint author), STANFORD UNIV,DEPT COMP SCI,PALO ALTO,CA 94304, USA. NR 6 TC 9 Z9 9 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELL PI MENLO PK PA 445 BURGESS DRIVE, MENLO PK, CA 94025-3496 SN 0738-4602 J9 AI MAG JI AI Mag. PD WIN PY 1993 VL 14 IS 4 BP 51 EP & PG 0 WC Computer Science, Artificial Intelligence SC Computer Science GA MM529 UT WOS:A1993MM52900005 ER PT J AU LOH, CY HUI, WH AF LOH, CY HUI, WH TI LAGRANGIAN RANDOM CHOICE METHOD FOR STEADY 2-DIMENSIONAL SUPERSONIC HYPERSONIC FLOW SO AIAA JOURNAL LA English DT Article AB GLIMM'S random choice method has been successfully applied to numerically solve the two-dimensional steady Euler equations of gas dynamics based on a new Lagrangian formulation. The method is easy to program, fast to execute, yet it is very accurate and robust. It requires no grid generation, resolves slipline and shock discontinuities crisply, can handle boundary conditions most easily, and is applicable to hypersonic as well as supersonic flow. C1 HONG KONG UNIV SCI & TECHNOL,DEPT MATH,KOWLOON,HONG KONG. RP LOH, CY (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1993 VL 31 IS 12 BP 2193 EP 2194 DI 10.2514/3.11913 PG 2 WC Engineering, Aerospace SC Engineering GA MK135 UT WOS:A1993MK13500001 ER PT J AU KUSSOY, MI HORSTMAN, KC HORSTMAN, CC AF KUSSOY, MI HORSTMAN, KC HORSTMAN, CC TI HYPERSONIC CROSSING SHOCK-WAVE TURBULENT-BOUNDARY-LAYER INTERACTIONS SO AIAA JOURNAL LA English DT Article AB Experimental data for two three-dimensional intersecting shock-wave/turbulent-boundary-layer interaction flows at Mach 8.3 are presented. The test bodies, composed of two sharp fins fastened to a flat plate test bed, were designed to generate flows with varying degrees of pressure gradient, boundary-layer separation, and turning angle. The data include surface pressure and heat transfer distributions as well as mean flowfield surveys both in the undisturbed and interaction regimes. The persistence of an extensive low-pressure region throughout the flowfield demonstrates that a sidewall compression inlet is not an efficient pressure increasing device. The data have been obtained in sufficient detail to validate existing or future computational models of these hypersonic flows. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP KUSSOY, MI (reprint author), ELORET INST,PALO ALTO,CA 94303, USA. NR 6 TC 18 Z9 19 U1 0 U2 3 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 1993 VL 31 IS 12 BP 2197 EP 2203 DI 10.2514/3.11915 PG 7 WC Engineering, Aerospace SC Engineering GA MK135 UT WOS:A1993MK13500003 ER PT J AU PAULEY, WR EATON, JK CUTLER, AD AF PAULEY, WR EATON, JK CUTLER, AD TI DIVERGING BOUNDARY-LAYERS WITH ZERO STREAMWISE PRESSURE-GRADIENT AND NO WALL CURVATURE SO AIAA JOURNAL LA English DT Article ID COMPLEX TURBULENT FLOWS; DIVERGENCE; SYMMETRY; PLANES AB The effects of spanwise divergence (partial derivative W/partial derivative z) on the boundary layer forming between a pair of embedded streamwise vortices with the common flow between them directed toward the wall was studied. Measurements indicate that divergence controls the rate of development of the boundary layer and that large divergence significantly retards boundary-layer growth and enhances skin friction in agreement with previous studies. Even with divergence, however, the local similarity relationships for two-dimensional boundary layers are satisfactory and the turbulence structure is not significantly modified. Spanwise divergence did not significantly affect either the Reynolds stress or turbulent triple-product distributions. C1 STANFORD UNIV,DEPT MECH ENGN,STANFORD,CA 94305. GEORGE WASHINGTON UNIV,JIAFS,NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP PAULEY, WR (reprint author), PENN STATE UNIV,DEPT AEROSP ENGN,UNIV PK,PA 16802, USA. NR 18 TC 1 Z9 1 U1 1 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 1993 VL 31 IS 12 BP 2212 EP 2219 DI 10.2514/3.11917 PG 8 WC Engineering, Aerospace SC Engineering GA MK135 UT WOS:A1993MK13500005 ER PT J AU SHEBALIN, JV AF SHEBALIN, JV TI PSEUDOSPECTRAL SIMULATION OF SHOCK-TURBULENCE INTERACTIONS SO AIAA JOURNAL LA English DT Note ID STOKES C1 NASA,LANGLEY RES CTR,THEORET FLOW PHYS BRANCH,HAMPTON,VA 23681. RP SHEBALIN, JV (reprint author), NASA,LANGLEY RES CTR,INST COMP APPLICAT SCI & ENGN,HAMPTON,VA 23681, USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1993 VL 31 IS 12 BP 2378 EP 2380 DI 10.2514/3.11941 PG 3 WC Engineering, Aerospace SC Engineering GA MK135 UT WOS:A1993MK13500029 ER PT J AU NEMETH, NN POWERS, LM JANOSIK, LA GYEKENYESI, JP AF NEMETH, NN POWERS, LM JANOSIK, LA GYEKENYESI, JP TI DESIGNING CERAMIC COMPONENTS FOR DURABILITY SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article C1 CLEVELAND STATE UNIV,CLEVELAND,OH 44115. RP NEMETH, NN (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 13 Z9 13 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD DEC PY 1993 VL 72 IS 12 BP 59 EP & PG 0 WC Materials Science, Ceramics SC Materials Science GA ML156 UT WOS:A1993ML15600006 ER PT J AU KREBS, JM SCHNEIDER, VS LEBLANC, AD KUO, MC SPECTOR, E LANE, HW AF KREBS, JM SCHNEIDER, VS LEBLANC, AD KUO, MC SPECTOR, E LANE, HW TI ZINC AND COPPER BALANCES IN HEALTHY ADULT MALES DURING AND AFTER 17 WK OF BED REST SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Article DE ZINC; COPPER; SPACE FLIGHT; BED REST; DISUSE ATROPHY; TRACE ELEMENTS ID SPACE-FLIGHT; BONE; TRANSFORMATION; PHYTOHEMAGGLUTININ; HOMEOSTASIS; LYMPHOCYTES; DIETS; MASS; IONS AB The effects of long-term bed rest on zinc and copper balances were measured in seven healthy men. Volunteers aged 22-54 y (xBAR +/- SD, 34 +/- 12 y), 168-185 cm in height (173 +/- 5 cm), and 64-86 kg in weight (74 +/- 9 kg) remained on a metabolic ward for 29 wk. Subjects were ambulatory during weeks 1-5, remained in continuous bed rest for weeks 6-22, and were reambulated during weeks 23-29. Copper and zinc were measured in weekly urine and fecal composites. Dietary intakes provided (xBAR +/- SD) 19.2 +/- 1.2 mumol Cu (1.22 +/- 0.08 mg), 211 +/- 11 mumol Zn (13.81 +/- 0.72 mg), 25.2 +/- 1.2 mmol Ca (1011 +/- 46 mg), 1086 +/- 46 mmol N (15.21 +/- 0.65 g), and 48.1 +/- 1.4 mmol K (1489 +/- 44 mg)/d. Bed rest increased fecal zinc excretion and decreased zinc balance, whereas copper balance was unchanged. Reambulation decreased fecal zinc excretion and increased both zinc and copper balances. These results suggest that during long-term bed rest or space flight, individuals will lose total body zinc and will retain more zinc and copper when they reambulate. C1 NASA,LYNDON B JOHNSON SPACE CTR,SPACE BIOMED RES INST,HOUSTON,TX 77058. NASA,LYNDON B JOHNSON SPACE CTR,BIOMED OPERAT & RES BRANCH,HOUSTON,TX 77058. BAYLOR COLL MED,DEPT MED,HOUSTON,TX 77030. KRUG LIFE SCI,HOUSTON,TX. RP KREBS, JM (reprint author), UNIV TEXAS,MED BRANCH,DEPT HBC & G,414 GAIL BORDEN F50,GALVESTON,TX 77555, USA. FU NCRR NIH HHS [RR02558, RR00350] NR 31 TC 6 Z9 6 U1 0 U2 0 PU AMER SOC CLINICAL NUTRITION 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 DEC PY 1993 VL 58 IS 6 BP 897 EP 901 PG 5 WC Nutrition & Dietetics SC Nutrition & Dietetics GA MK466 UT WOS:A1993MK46600015 PM 8249875 ER PT J AU MUKUNDA, HS DRUMMOND, JP AF MUKUNDA, HS DRUMMOND, JP TI 2-DIMENSIONAL LINEAR-STABILITY OF PREMIXED LAMINAR FLAMES UNDER ZERO-GRAVITY SO APPLIED SCIENTIFIC RESEARCH LA English DT Article ID FRONTS AB This paper reports on the numerical study of the linear stability of laminar premixed flames under zero gravity. The study specifically addresses the dependence of stability on finite rate chemistry with low activation energy and variable thermodynamic and transport properties. The calculations show that activation energy and details of chemistry play a minor role in altering the linear neutral stability results from asymptotic analysis. Variable specific heat makes a marginal change to the stability. Variable transport properties on the other hand tend to substantially enhance the stability from critical wave number of about 0.5 to 0.20. Also, it appears that the effects of variable properties tend to nullify the effects of non-unity Lewis number. When the Lewis number of a single species is different from unity, as will happen in a hydrogen-air premixed flame, the stability results remain close to that of unity Lewis number. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP MUKUNDA, HS (reprint author), INDIAN INST SCI,DEPT AEROSP ENGN,BANGALORE 560012,KARNATAKA,INDIA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0003-6994 J9 APPL SCI RES JI Appl. Sci. Res. PD DEC PY 1993 VL 51 IS 4 BP 687 EP 711 DI 10.1007/BF00849273 PG 25 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA MB089 UT WOS:A1993MB08900004 ER PT J AU MADORE, BF FREEDMAN, WL LEE, MG AF MADORE, BF FREEDMAN, WL LEE, MG TI RESOLVED STARS IN NEARBY GALAXIES - GROUND-BASED PHOTOMETRY OF M81 SO ASTRONOMICAL JOURNAL LA English DT Article ID STELLAR CONTENT AB Using the Canada-France-Hawaii Telescope (CFHT) we have obtained three closely spaced epochs of calibrated BVRI CCD imaging of two fields in M81, each known to contain a thirty-day Cepheid. Calibrated BVRI photometry of the brightest stars in these fields is presented. The slope of the luminosity function from the brightest 3-4 mag of the main-sequence blue plume is consistent with similar determinations of the apparent luminosity function in other resolved galaxies, thereby removing the one potential deviation from universality noted by Freedman [ApJ, 299, 74 (1985)] in a photographic study of luminosity functions in nearby resolved galaxies. Under the assumption that the two Cepheids are representative, a reddening-law fit to the multiwavelength BVRI period-luminosity moduli give a true distance modulus of (m-M)0 = 27.79 mag for M81, corresponding to a linear distance of 3.6 Mpc. An error analysis shows that the derived true distance modulus has a random error of +/- 0.28 mag (due to the photometric uncertainties in the BVRI data), with a systematic uncertain ty of +/- 0.10 mag (accounting for the combined effects of unknown phasing of the data points, and the unknown positioning of these particular stars within the Cepheid instability strip). C1 CARNEGIE INST WASHINGTON,THE OBSERVATORIES,PASADENA,CA 91101. RP MADORE, BF (reprint author), NASA,CALTECH,IPAC EXTRAGALACT DATABASE,CTR INFRARED ANAL & PROC,PASADENA,CA 91125, USA. NR 13 TC 10 Z9 10 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 1993 VL 106 IS 6 BP 2243 EP 2251 DI 10.1086/116797 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK862 UT WOS:A1993MK86200005 ER PT J AU FEKEL, FC HENRY, GW BUSBY, MR EITTER, JJ AF FEKEL, FC HENRY, GW BUSBY, MR EITTER, JJ TI CHROMOSPHERICALLY ACTIVE STARS .11. GIANTS WITH COMPACT HOT COMPANIONS AND THE BARIUM STAR SCENARIO SO ASTRONOMICAL JOURNAL LA English DT Article ID PHOTOELECTRIC RADIAL-VELOCITIES; SPECTROSCOPIC BINARY ORBITS; WHITE-DWARF COMPANION; SUBGIANT CH-STARS; SPECTRAL CLASSIFICATION; AY CETI; ABUNDANCES; CATALOG; PARAMETERS; EVOLUTION AB We have determined spectroscopic orbits for three chromospherically active giants that have hot compact companions. They are HD 160538 (K0 III+wd, P=904 days), HD 165141 (Gg III+wd, P approximately 5200 days), and HD 185510 (K0 III+sdB, P=20.6619 days). By fitting an IUE spectrum with theoretical models, we find the white dwarf companion of HD 165141 has a temperature of about 35 000 K. Spectral types and rotational velocities have been determined for the three giants and distances have been estimated. These three systems and 39 Ceti are compared with the barium star mass-transfer scenario. The long-period mild barium giant HD 165141 as well as HD 185510 and 39 Ceti, which have relatively short periods and normal abundance giants, appear to be consistent with this scenario, The last binary, HD 160538, a system with apparently near solar abundances, a white dwarf companion, and orbital characteristics similar to many barium stars, demonstrates that the existence of a white dwarf companion is insufficient to produce a barium star. The paucity of systems with confirmed white dwarf companions makes abundance analyses of HD 160538 and HD 165141 of great value in examining the role of metallicity in barium star formation. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812. IOWA STATE UNIV SCI & TECHNOL,ERWIN W FICK OBSERV,AMES,IA 50011. RP FEKEL, FC (reprint author), TENNESSEE STATE UNIV,CTR EXCELLENCE INFORMAT SYST,330 10TH AVE N,NASHVILLE,TN 37203, USA. NR 74 TC 25 Z9 25 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 1993 VL 106 IS 6 BP 2370 EP 2382 DI 10.1086/116809 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK862 UT WOS:A1993MK86200017 ER PT J AU SHORE, SN SONNEBORN, G STARRFIELD, S GONZALEZRIESTRA, R AF SHORE, SN SONNEBORN, G STARRFIELD, S GONZALEZRIESTRA, R TI THE EARLY ULTRAVIOLET SPECTRAL EVOLUTION OF NOVA CYGNI-1992 SO ASTRONOMICAL JOURNAL LA English DT Article ID AUSTRINAE 1981; NEON; VULPECULAE; ABUNDANCES AB We report on the high resolution ultraviolet line profile evolution of Nova Cygni 1992 using the International Ultraviolet Explorer satellite and the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope. Our observations cover the period from discovery in 1992 February through 1993 April. The initial expansion velocity, derived from P Cyg profiles on Mg II and other resonance lines, was about 4500 km s-1. All resonance transitions displayed P Cyg profiles around the time of UV maximum. We first discuss the spectral development as the initially optically thick atomic absorption curtain became optically thin. We then present the interpretation of the nebular spectral stage. The high resolution line profiles show that the shell rapidly developed nearly symmetric knots, or filaments, of emission. The optically thin transitions show an emission weighted expansion velocity of about 1800 km s-1, consistent with the velocity inferred from the radio and infrared data. The emission lines display a symmetric set of filaments that appeared as soon as the line profiles became optically thin. The GHRS observations demonstrate that the filaments were located in the inner, slower moving, parts of the ejecta. These probably record an initial low wave number instability imposed on the ejecta at the time of outburst. We suggest that the likely cause is a Rayleigh-Taylor instability. The emission at later stages is dominated by the filaments and, since this phenomenon is seen in virtually all novae, nebular line formation codes will have to account for the density inhomogeneities in order to adequately determine abundances for nova ejecta. The derived ejecta mass exceeds 10(-4)Y-1/2 M. where Y is the helium abundance enhancement factor, consistent with the long UV rise time. No simulations of accretion onto massive ONeMg white dwarfs can eject such massive envelopes; there is a serious disagreement between the observations and current theory. C1 INDIANA UNIV S BEND,DEPT PHYS & ASTRON,S BEND,IN 46634. NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. ARIZONA STATE UNIV,DEPT PHYS & ASTRON,TEMPE,AZ 85287. EUROPEAN SPACE AGCY,IUE OBSERV,VILLAFRANCA,SPAIN. RP SHORE, SN (reprint author), NASA,GODDARD SPACE FLIGHT CTR,COMP SCI CORP,GHRS SCI TEAM,CODE 681,GREENBELT,MD 20771, USA. NR 32 TC 65 Z9 65 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 1993 VL 106 IS 6 BP 2408 EP 2428 DI 10.1086/116812 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK862 UT WOS:A1993MK86200020 ER PT J AU GILLILAND, RL BROWN, TM KJELDSEN, H MCCARTHY, JK PERI, ML BELMONTE, JA VIDAL, I CRAM, LE PALMER, J FRANDSEN, S PARTHASARATHY, M PETRO, L SCHNEIDER, H STETSON, PB WEISS, WW AF GILLILAND, RL BROWN, TM KJELDSEN, H MCCARTHY, JK PERI, ML BELMONTE, JA VIDAL, I CRAM, LE PALMER, J FRANDSEN, S PARTHASARATHY, M PETRO, L SCHNEIDER, H STETSON, PB WEISS, WW TI A SEARCH FOR SOLAR-LIKE OSCILLATIONS IN THE STARS OF M67 WITH CCD ENSEMBLE PHOTOMETRY ON A NETWORK OF 4-M TELESCOPES SO ASTRONOMICAL JOURNAL LA English DT Article ID OPEN CLUSTER M67; TIME-SERIES ANALYSIS; SPECTROSCOPIC BINARIES; ACOUSTIC-OSCILLATIONS; STELLAR PHOTOMETRY; ASTEROSEISMOLOGY; STRAGGLERS; PRECISION; SPECTRUM; MODES AB Results are presented from a large observational project directed toward the detection of solar-like oscillations in an ensemble of open cluster stars. Seven groups collaborated in 1992 January to observe twelve stars in M67 with 4 m class telescopes for a one week period. High quality time series were collected on 22 telescope nights for a total of 156 h. The technique of CCD ensemble photometry allowed precisions of about 250 mumag per minute to be reached in the best cases, and provided robust results in conditions that sometimes were far from ''photometric.'' The longitude-distributed network, coupled with generally low noise levels, provided a good window function and yielded detection thresholds of about 20 mumag (five times solar) for solar-like oscillations in the best ensemble stars. Sensitivity to solar-like oscillations over our twelve ensemble stars ranges from 30% to a factor of three better than obtained previously by any group. When our simultaneous results for 12 stars (prior most sensitive result followed from photoelectric photometry on a single star) is taken into account this project provides a (multiplexed) factor of 20 to 30 gain over previous experiments. For two stars we derive interesting upper limits for oscillation amplitudes that are near the lower range predicted by theory. Over half the stars in the ensemble show suggestive evidence for oscillations; we develop the evidence for, and the cautions against, claiming detections in these cases. Given the unique aspects of this project we describe in detail the observation planning process, data acquisition, reductions, and ensuing analyses. We argue that a more aggressive network campaign could provide a factor of two sensitivity gain with a resulting high probability of attaining unambiguous oscillation detections on most of the stars in the M67 ensemble. C1 NCAR,HIGH ALTITUDE OBSERV,BOULDER,CO 80307. EUROPEAN SO OBSERV,KARL SCHWARZSCHILDSTR 2,W-8046 GARCHING,GERMANY. CALTECH,PALOMAR OBSERV,PASADENA,CA 91125. INST ASTROFIS CANARIAS,E-38200 LA LAGUNA,SPAIN. UNIV SYDNEY,SCH PHYS,SYDNEY,NSW 2006,AUSTRALIA. AARHUS UNIV,INST PHYS & ASTRON,DK-8000 AARHUS,DENMARK. INDIAN INST ASTROPHYS,BANGALORE 560034,INDIA. UNIV STERNWARTE,W-3400 GOTTINGEN,GERMANY. NATL RES COUNCIL CANADA,DOMINION ASTROPHYS OBSERV,VICTORIA V8X 4M6,BC,CANADA. INST ASTRON,A-1180 VIENNA,AUSTRIA. NORD OPT TELESCOPE,OBSERV ROQUE MUCHACHOS,ISLA DE LA PALMA,SPAIN. MAX PLANCK INST ASTRON,GERMAN SPANISH ASTRON CTR,W-6900 HEIDELBERG,GERMANY. RP GILLILAND, RL (reprint author), AURA INC,NASA,INST SPACE TELESCOPE SCI,3700 SAN MARTIN DR,BALTIMORE,MD 21218, USA. RI Cram, Lawrence/H-4059-2012 OI Cram, Lawrence/0000-0002-8096-447X NR 55 TC 95 Z9 96 U1 1 U2 4 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 1993 VL 106 IS 6 BP 2441 EP 2476 DI 10.1086/116814 PG 36 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK862 UT WOS:A1993MK86200022 ER PT J AU BOPP, BW FEKEL, FC AUFDENBERG, JP DEMPSEY, R DADONAS, V AF BOPP, BW FEKEL, FC AUFDENBERG, JP DEMPSEY, R DADONAS, V TI EXTREMELY ACTIVE LONG-PERIOD RS CVN BINARY HD-12545 SO ASTRONOMICAL JOURNAL LA English DT Article ID H-ALPHA EMISSION; CA-II-H; CHROMOSPHERE BINARY; F-DWARFS; K-STAR; LITHIUM; LINE; SPECTRA; SINGLE; GIANT AB The active-chromosphere giant HD 12545 is noteworthy for its remarkable 1990 photometric amplitude of 0.6 mag in V, which implies that nearly half the visible hemisphere of the star was covered by cool spots. We report the results of a spectroscopic study of HD 12545, showing it to be an active-chromosphere binary with an orbital period of 23.97 days. We establish the spectral type as K0 III, and measure v sin i = 17 +/- 2 km s-1. The various indicators of activity in the optical and ultraviolet suggest that HD 12545 is one of the most active RS CVn systems yet observed. Halpha is a broad, variable emission feature, with a strength comparable to what is observed in very active RS CVn systems such as V711 Tau (HR 1099) or II Peg. The surface fluxes of chromospheric and transition-region lines in the UV range from 10 to nearly 400 times the solar values. With a moderately strong Li I lambda6707 feature and a large space motion, HD 12545 is an unusual but not unique giant, since these properties are similar to those of the single active-chromosphere giant HD 33798. C1 UNIV TOLEDO,DEPT PHYS & ASTRON,TOLEDO,OH 43606. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. VILNIUS OBSERV,ASTRON OBSERV,VILNIUS 2009,LITHUANIA. RP BOPP, BW (reprint author), UNIV TOLEDO,RITTER OBSERV,TOLEDO,OH 43606, USA. NR 36 TC 14 Z9 14 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 1993 VL 106 IS 6 BP 2502 EP 2509 DI 10.1086/116818 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK862 UT WOS:A1993MK86200026 ER PT J AU ELLIOT, JL BOSH, AS COOKE, ML BLESS, RC NELSON, MJ PERCIVAL, JW TAYLOR, MJ DOLAN, JF ROBINSON, EL VANCITTERS, GW AF ELLIOT, JL BOSH, AS COOKE, ML BLESS, RC NELSON, MJ PERCIVAL, JW TAYLOR, MJ DOLAN, JF ROBINSON, EL VANCITTERS, GW TI AN OCCULTATION BY SATURNS RINGS ON 1991 OCTOBER 2-3 OBSERVED WITH THE HUBBLE-SPACE-TELESCOPE SO ASTRONOMICAL JOURNAL LA English DT Article ID RADIO OCCULTATION; RESONANCE STRUCTURES; URANIAN RINGS; CANDIDATES; PERFORMANCE; PHOTOMETER; URANUS; PLUTO; IUE AB An occultation of the star GSC 6323-01396 (V = 11.9) by Saturn's rings was observed with the High-Speed Photometer on the Hubble Space Telescope (HST) on 1991 October 2-3. This occultation occurred when Saturn was near a stationary point, so the apparent motion of Saturn relative to the star was dominated by the HST orbital motion (8 km s-1). Data were recorded simultaneously at effective wavelengths of 3200 and 7500 angstrom, with an integration time of 0.15 s. Observations were interrupted by passages of the spacecraft behind the Earth and through the South Atlantic Anomaly. Fifteen segments of occultation data, totaling 6.8 h, were recorded in 13 successive orbits during the 20.0 h interval from UTC 1991 October 2, 19:35 until UTC 1991 October 3, 15:35. Occultations by 43 different features throughout the classical rings were unambiguously identified in the light curve, with a second occultation by 24 of them occurring due to spacecraft orbital parallax during this extremely slow event. Occultation times for features currently presumed circular were measured and employed in a geometrical model for the rings. This model, relating the observed occultation times to feature radii and longitudes, is presented here and is used in a least-squares fit for the pole direction and radius scale of Saturn's ring system. Combined fits with the HST occultation times and 28 Sgr occultation times [French et al., Icarus, 103, 163 (1993) and Hubbard et al., Icarus, 103, 215 (1993)] yield a ring-pole direction of alpha = 40.5929-degrees +/- 0.0151 and delta = 83.5348-degrees +/- 0.0053-degrees (J2000.0, at the Voyager 1 epoch of UTC 1980 Nov. 12 23:46:32). This result, independent of Voyager data and its associated trajectory errors, is compared with other recent determinations of the pole and radius scale. C1 LOWELL OBSERV,FLAGSTAFF,AZ 86001. MIT,DEPT PHYS,CAMBRIDGE,MA 02139. UNIV WISCONSIN,SPACE ASTRON LAB,MADISON,WI 53706. NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. UNIV TEXAS,DEPT ASTRON,AUSTIN,TX 78712. NATL SCI FDN,DIV ASTRON SCI,WASHINGTON,DC 20550. USN ACAD,DEPT AEROSP ENGN,ANNAPOLIS,MD 21402. RP ELLIOT, JL (reprint author), MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139, USA. NR 54 TC 24 Z9 24 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 1993 VL 106 IS 6 BP 2544 EP 2572 DI 10.1086/116824 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK862 UT WOS:A1993MK86200032 ER PT J AU LANZ, T MATHYS, G AF LANZ, T MATHYS, G TI A SEARCH FOR MAGNETIC-FIELDS IN AM STARS SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE STARS, MAGNETIC FIELDS, CHEMICALLY PECULIAR, FUNDAMENTAL PARAMETERS ID UPPER-MAIN-SEQUENCE; AP STARS; SPLIT LINES; CATALOG AB Although Am stars have been assumed to be non-magnetic stars, we found recently that the hot Am star o Peg has a magnetic field of the order of 2 kG, with a complex structure. Therefore, we reconsidered the question of magnetism among upper main sequence chemically peculiar stars. We report here new observations of a pair of magnetically sensitive Fe II lines in the red spectrum of Am stars and of HgMn stars. Two other hot Am stars, HD 29173 and HD 195479A, are likely to possess also a magnetic field of about the same strength. It is striking that 3 out of 4 hot Am stars observed up to now could be magnetic. On the other hand, this fast method is limited by blends and cannot provide a satisfactory diagnosis for classical Am stars and for HgMn stars. A multi-line approach must be the next step towards our understanding of magnetism among these chemically peculiar stars. C1 EUROPEAN SO OBSERV, SANTIAGO 19, CHILE. RP LANZ, T (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ASTRON & SOLAR PHYS LAB, CODE 681, GREENBELT, MD 20771 USA. NR 33 TC 24 Z9 25 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 DEC PY 1993 VL 280 IS 2 BP 486 EP 492 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML253 UT WOS:A1993ML25300016 ER PT J AU HABERL, F WHITE, NE AF HABERL, F WHITE, NE TI A ROSAT OBSERVATION OF DELTA-ORIONIS-A SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE STARS, ATMOSPHERES; STARS, BINARIES, ECLIPSING; STARS, EARLY TYPE; STARS, SUPERGIANTS; X-RAYS, STARS; STARS, INDIVIDUAL, DELTA-ORI-A ID X-RAY-EMISSION; EARLY-TYPE STARS; OB SUPER-GIANTS; HOT STARS; WINDS; VARIABILITY; CORONAE; SPECTRA AB Delta Orionis A was observed with ROSAT in February 1991 at ten different phases of the 5.7 day binary orbit. The soft X-ray emission shows little dependence on binary phase favouring models for the production of the soft X-rays in the outer parts of the stellar wind. The energy spectrum obtained with the PSPC shows two thermal components with temperatures of 0.1 and 0.2 keV. The temperature and absorption of the hotter component is consistent with the Einstein SSS spectrum obtained in 1979. The two temperatures suggest either two emission regions with different temperatures, or one emission region with a temperature distribution where the hotter parts are closer to the OB stars than the cooler parts as indicated by the higher absorption of the hotter spectral component. This would be in contrast to stellar wind shock models which predict shock temperatures increasing with distance to the star. C1 NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS, GREENBELT, MD 20771 USA. RP HABERL, F (reprint author), MAX PLANCK INST EXTRATERR PHYS, GIESSENBACHSTR, D-85748 GARCHING, GERMANY. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 21 TC 7 Z9 7 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 1993 VL 280 IS 2 BP 519 EP 522 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML253 UT WOS:A1993ML25300019 ER PT J AU DEBOER, KS PASCUAL, PR WAMSTEKER, W SONNEBORN, G FRANSSON, C BOMANS, DJ KIRSHNER, RP AF DEBOER, KS PASCUAL, PR WAMSTEKER, W SONNEBORN, G FRANSSON, C BOMANS, DJ KIRSHNER, RP TI INTERGALACTIC AND GALACTIC CLOUDS ON THE LINE-OF-SIGHT TO SN-1993J IN M-81 SEEN IN IUE SPECTRA SO ASTRONOMY & ASTROPHYSICS LA English DT Letter DE SUPERNOVAE, INDIVIDUAL, SN-1993J; INTERSTELLAR CLOUDS; GALACTIC HALO; GALAXIES, INDIVIDUAL, M81; INTERGALACTIC MEDIUM; ULTRAVIOLET, INTERSTELLAR ID NEUTRAL HYDROGEN; INTERSTELLAR LINES; SN-1987A; GALAXIES AB High resolution IUE spectra of SN 1993J in M81 show the existence of several clouds on the line of sight. These include local galactic gas at 0 km s-1, gas in M81 at -130 km s-1, a cloud in the halo of the Milky Way near -45 km s-1, and an intergalactic cloud near +140 km s-1. Arguments for each of these locations are given. There is little gas in M81 in front of SN 1993J and no detectable CIV at or near -130 km s-1. The gas of the halo of the Milky Way shows a large amount of CIV and SiIV. The intergalactic cloud shows a large velocity width extending from +100 km s-1 to +200 km s-1 and is very prominent in the absorption lines of AlIII, SiIV, and CIV. It may be related to energetic events in the M81 group of galaxies. C1 IUE OBSERV, ESA, VILSPA, E-28080 MADRID, SPAIN. NASA, GSFC, ASTRON & SOLAR PHYS LAB, GREENBELT, MD 20771 USA. STOCKHOLM OBSERV, S-13336 SALTSJOBADEN, SWEDEN. HARVARD UNIV, CTR ASTROPHYS, CAMBRIDGE, MA 02138 USA. RP DEBOER, KS (reprint author), UNIV BONN, HUGEL 71, D-53121 BONN, GERMANY. RI Sonneborn, George/D-5255-2012 NR 21 TC 15 Z9 15 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 1993 VL 280 IS 1 BP L15 EP L18 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK015 UT WOS:A1993MK01500005 ER PT J AU YAQOOB, T SERLEMITSOS, PJ MUSHOTZKY, RF WEAVER, KA MARSHALL, FE PETRE, R AF YAQOOB, T SERLEMITSOS, PJ MUSHOTZKY, RF WEAVER, KA MARSHALL, FE PETRE, R TI A BBXRT OBSERVATION OF THE HIGH-LUMINOSITY QUASAR H1821+643 SO ASTROPHYSICAL JOURNAL LA English DT Article DE QUASARS, INDIVIDUAL (H1821+643); X-RAYS, GALAXIES ID ACTIVE GALACTIC NUCLEI; PARAMETER-ESTIMATION; RAY; ASTRONOMY AB We present the results of an observation of the high-luminosity quasar H1821 + 643 with the Broad-Band X-Ray Telescope (BBXRT) performed in 1990 December. The 2-10 keV flux and power-law spectral index are found to be consistent with previous values obtained by EXOSAT and Ginga which indicates that the medium-energy continuum has remained steady for at least approximately 6.5 yr. Contrasting with this is the result that the Fe Kalpha line present in Ginga observations of this source (observed equivalent width 210 +/- 80 eV) is not detected by BBXRT. We estimate that a narrow iron line, if it had been present during the BBXRT observation at the same strength as it was in the Ginga observations, should have been detected with a probability of 88%. We argue against variability of the line between the BBXRT and Ginga observations and suggest the possibility that the line is broad. RP YAQOOB, T (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 18 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 1 PY 1993 VL 418 IS 2 BP 638 EP 643 DI 10.1086/173423 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MJ035 UT WOS:A1993MJ03500009 ER PT J AU PETRE, R MUSHOTZKY, RF SERLEMITSOS, PJ JAHODA, K MARSHALL, FE AF PETRE, R MUSHOTZKY, RF SERLEMITSOS, PJ JAHODA, K MARSHALL, FE TI THE BROAD-BAND X-RAY-SPECTRUM OF THE NUCLEUS OF M81 SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, INDIVIDUAL (M81); GALAXIES, NUCLEI; GALAXIES, SEYFERT; X-RAYS, GALAXIES ID ACTIVE GALACTIC NUCLEI; SEYFERT-GALAXIES; ACCRETION DISKS; EMISSION-LINES; COLD MATTER; QUASARS; REFLECTION; BINARIES; RATIO AB We report on the results of a 2000 s observation of the nearby spiral galaxy M81 using the Broad-Band X-Ray Telescope (BBXRT). The observed X-ray emission is dominated by the flux from the nucleus, classified optically as a low-ionization nuclear emission-line region (LINER) (Filippenko & Sargent 1988). The 0.5-10 keV spectrum is well fit by a simple power law of photon index 2.20 (+0.3, -0.15), distinct from the flatter index observed in Seyfert galaxies. An upper limit of 90 eV has been placed on the equivalent width of any Fe K fluorescent feature. Taken together with the nondetection in the optical and UV of any nonthermal continuum emission, this argues strongly for the absence of an accretion disk around the M81 nucleus. Given the inferred low accretion rate in M81 and the very high X-ray-to-UV-optical luminosity ratio compared with the more X-ray-luminous Seyfert galaxies, it is very likely that the X-ray production mechanism is qualitatively different. The lack of strong X-ray lines leads us to reject a starburst origin of the X-ray flux. Based on the similarity of the M81 X-ray spectrum to that of other LINERs having broad Halpha emission, such as Pic A, NGC 3998, and M87, some of these conclusions may be applicable, in general, to this type of LINER. RP PETRE, R (reprint author), NASA,GODDARD SPACE FLIGHT CTR,XRAY ASTROPHYS BRANCH,GREENBELT,MD 20771, USA. RI Jahoda, Keith/D-5616-2012 NR 54 TC 33 Z9 33 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 1993 VL 418 IS 2 BP 644 EP 652 DI 10.1086/173424 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MJ035 UT WOS:A1993MJ03500010 ER PT J AU TURNER, TJ URRY, CM MUSHOTZKY, RF AF TURNER, TJ URRY, CM MUSHOTZKY, RF TI POSITION-SENSITIVE PROPORTIONAL COUNTER SOFT-X-RAY OBSERVATIONS OF SEYFERT 2 GALAXIES SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, SEYFERT; X-RAYS, GALAXIES ID EMISSION-LINE GALAXIES; NGC-1068; SPECTROPOLARIMETRY; SPECTRUM AB We present the results from ROSAT PSPC soft X-ray (0.1-2.0 keV) observations of six Seyfert 2 galaxies, chosen from the brightest Seyfert 2's detected with the Einstein Imaging Proportional Counter. All of the targets were detected with the ROSAT PSPC. Spatial analysis shows that the source density within a few arcminutes of each Seyfert 2 galaxy is a factor of approximately 8 higher than in the rest of the inner field of view of the PSPC images. In NGC 1365 it appears that the serendipitous sources may be X-ray binary systems in the host galaxy. The proximity of the serendipitous sources, typically within a few arcminutes of the target Seyfert 2, means that previous X-ray observations of the Seyfert 2 galaxies have been significantly contaminated, and that source confusion is important on a spatial scale of approximately 1'. Some spectra, most notably Mrk 3 and NGC 1365, indicate the presence of a high equivalent width soft X-ray line blend consistent with unresolved iron L and oxygen K emission. RP TURNER, TJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. RI Urry, Claudia/G-7381-2011 OI Urry, Claudia/0000-0002-0745-9792 NR 50 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 1 PY 1993 VL 418 IS 2 BP 653 EP 667 DI 10.1086/173425 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MJ035 UT WOS:A1993MJ03500011 ER PT J AU SMITH, EP LANDSMAN, WB HILL, RS BOHLIN, RC CHENG, KP HINTZEN, P MARAN, SP OCONNELL, RW ROBERTS, MS SMITH, AM STECHER, TP AF SMITH, EP LANDSMAN, WB HILL, RS BOHLIN, RC CHENG, KP HINTZEN, P MARAN, SP OCONNELL, RW ROBERTS, MS SMITH, AM STECHER, TP TI ULTRAVIOLET MORPHOLOGIES OF GLOBULAR-CLUSTERS OBSERVED WITH THE ULTRAVIOLET IMAGING TELESCOPE SO ASTROPHYSICAL JOURNAL LA English DT Article DE GLOBULAR CLUSTER, GENERAL; STARS, HORIZONTAL-BRANCH; ULTRAVIOLET, STARS ID OMEGA-CENTAURI; COLOR GRADIENT; STARS; PHOTOMETRY; NGC-1904; CORE; M15; M3 AB We compare the ultraviolet (UV) and visible morphologies of globular clusters M3, M13, M79, and omega Cen, based on observations with the Ultraviolet Imaging Telescope (UIT) and ground-based telescopes. Global similarities (e.g., core radii) are found, along with other interesting features. These include a ring (r = 2.2') of UV-bright stars in omega Cen and a group of UV-bright objects near the center of M79. We find a color gradient in M79 but in no other cluster. The helium abundance in M79 is Y = 0.21 +/- 0.04, based on UV and visible color-magnitude diagrams. C1 ASSOC UNIV RES ASTRON INC,KITT PEAK NATL OBSERV,TUCSON,AZ. ASSOC UNIV RES ASTRON INC,CERRO TOLOLO INTER AMER OBSERV,NOAO,TUCSON,AZ. NASA,GODDARD SPACE FLIGHT CTR,HUGHES STX CORP,GREENBELT,MD 20771. SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218. CALIF STATE UNIV LONG BEACH,DEPT PHYS & ASTRON,LONG BEACH,CA 90840. UNIV VIRGINIA,DEPT ASTRON,CHARLOTTESVILLE,VA 22903. NATL RADIO ASTRON OBSERV,CHARLOTTESVILLE,VA 22903. RP SMITH, EP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,CODE 681,GREENBELT,MD 20771, USA. NR 28 TC 8 Z9 8 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 1993 VL 418 IS 2 BP 850 EP 854 DI 10.1086/173442 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MJ035 UT WOS:A1993MJ03500028 ER PT J AU MUKAI, K SHIOKAWA, K AF MUKAI, K SHIOKAWA, K TI THE EXOSAT MEDIUM-ENERGY (ME) SAMPLE OF DWARF NOVAE SO ASTROPHYSICAL JOURNAL LA English DT Article DE NOVAE, CATACLYSMIC VARIABLES; X-RAYS, STARS ID X-RAY-EMISSION; CATACLYSMIC VARIABLES; GALACTIC RIDGE; SS CYGNI; ACCRETION DISKS; OUTBURST; BINARIES AB We present our analysis of the EXOSAT medium energy (ME) archival data on dwarf novae. Many dwarf novae were observed with EXOSAT; unfortunately, a significant fraction resulted in nondetection or marginal detection with the ME instrument. Our analysis of the brightest dwarf nova, SS Cyg, shows little correlation between the count rate and the hardness ratio, contrary to an earlier report. This is likely to be the result of a slight error in background subtraction performed. The apparent lack of correlation favors a compact boundary layer between the accretion disk and the white dwarf as the hard X-ray emitting region, rather than an extended ''corona.'' According to our spectral fit, all dwarf nova data are compatible with a single-temperature (2->20 keV) bremsstrahlung continuum with an iron emission line near 6.7 keV. However, several sources show significant epoch-to-epoch variability, the origin of which is poorly understood at the moment. Better hard X-ray data are needed to advance our understanding of dwarf novae. With this knowledge, we investigate the contribution of dwarf novae to the Galactic ridge X-ray emission. They are found to be spectrally similar; using a reasonable estimate of the spatial distribution of dwarf novae, these systems appear to be a major, if not the dominant, component of the ridge emission. C1 UNIV MARYLAND,DEPT PHYS,COLL PK,MD 20742. RP MUKAI, K (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,CODE 668,GREENBELT,MD 20771, USA. NR 29 TC 51 Z9 51 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 1993 VL 418 IS 2 BP 863 EP 873 DI 10.1086/173444 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MJ035 UT WOS:A1993MJ03500030 ER PT J AU SMALE, AP MUSHOTZKY, RF SCHLEGEL, EM WEAVER, KA SERLEMITSOS, PJ MARSHALL, FE PETRE, R JAHODA, K AF SMALE, AP MUSHOTZKY, RF SCHLEGEL, EM WEAVER, KA SERLEMITSOS, PJ MARSHALL, FE PETRE, R JAHODA, K TI CYGNUS-X-3 IN AN ULTRAHIGH X-RAY STATE WITH NO DETECTED K-ALPHA LINE EMISSION SO ASTROPHYSICAL JOURNAL LA English DT Article DE BINARIES, CLOSE; STARS, INDIVIDUAL (CYGNUS X-3); X-RAYS, STARS ID LONG-TERM; RADIO OUTBURST; MODULATION; SCATTERING; DISCOVERY; EXPANSION; MODEL AB Cyg X-3 is well-known to be the brightest source of 6.7 keV iron K-line photons in the X-ray sky; this line has been unambiguously detected in data from OSO 8, Ariel 5, HEAO 1 A-2, the EXOSAT GSPC, Tenma, and Ginga, with measured physical widths (FWHM) ranging from 0.6 to 1.0 keV and equivalent widths typically from 0.5 to 1.7 keV. However, when the Shuttle-borne X-ray telescope BBXRT observed this source on 1990 December 5, the line was not detected. The BBXRT data show Cyg X-3 to be in an unusually high, soft state, with a luminosity of approximately 2 x 10(38) ergs s-1 (1-10 keV; at 10 kpc), above the Eddington limit. The continuum is well described by a blackbody with temperature kT = 1.13 +/- 0.02 keV, constituting 93% of the flux, plus an additional soft component. No iron line is seen in the spectrum, with formal 99% confidence upper limits on the equivalent width of 160 eV, 120 eV, and 75 eV for lines with FWHM = 1 keV, 600 eV, and 200 eV, respectively, for a line in the energy range 6.1-7.1 keV. Ninety percent confidence limits are typically 20 eV lower. We discuss these results in the context of the various physical models for Cyg X-3, and conclude that the high X-ray luminosity can be attributed to an increase in the blackbody component from the neutron star surface and inner accretion disk. We speculate that an increase in the mass-accretion rate may have caused the inner disk to become optically and geometrically thick, shielding the outer disk and much of the corona from the bulk of the central X-ray flux. Alternatively, a decrease in the extent of the azimuthal structure on the disk edge may have resulted in greater visibility of the central X-ray emitting region. RP SMALE, AP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. RI Jahoda, Keith/D-5616-2012 NR 30 TC 4 Z9 4 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 1993 VL 418 IS 2 BP 894 EP 898 DI 10.1086/173446 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MJ035 UT WOS:A1993MJ03500032 ER PT J AU LAROSA, TN MOORE, RL AF LAROSA, TN MOORE, RL TI A MECHANISM FOR BULK ENERGIZATION IN THE IMPULSIVE PHASE OF SOLAR-FLARES - MHD TURBULENT CASCADE SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; SUN, FLARES ID DRIVEN MAGNETIC RECONNECTION; 2-DIMENSIONAL MAGNETOHYDRODYNAMIC TURBULENCE; ENERGY-RELEASE; FILAMENT ERUPTIONS; RAY FLARES; CORONA; FRAGMENTATION; GENERATION; PHYSICS; MODEL AB We propose that the large production rate (approximately 10(36) s-1) of energetic electrons (greater than or similar to 25 keV) required to account for the impulsive-phase hard X-ray burst in large flares is achieved through MHD turbulent cascade of the bulk kinetic energy of the outflows from many separate reconnection events. Focusing on large two-ribbon eruptive flares as representative of most large flares, we envision the reconnection events to be the driven reconnection of oppositely directed elementary flux tubes pressing into the flare-length current-sheet interface that forms in the wake of the eruption of the sheared core of the preflare bipolar field configuration. We point our that, because the outflows from these driven reconnection events have speeds of order the Alfven speed and because the magnetic field reduces the shear viscosity of the plasma, it is reasonable that the outflows are unstable and turbulent, so that the kinetic energy of an outflow is rapidly dissipated through turbulent cascade. If the largest eddies in the turbulence have diameters of order the expected widths of the outflows (10(7)-10(8) cm), then the cascade dissipation of each of these eddies could produce a approximately 10(26) erg burst of energized electrons (approximately 3 x 10(33) 25 keV electrons) in approximately 0.3 s, which agrees well with hard X-ray and radio sub-bursts commonly observed during the impulsive phase. Of order 10(2) Simultaneous reconnection events with turbulent outflow would produce the observed rate of impulsive-phase plasma energization in the most powerful flares (approximately 10(36) 25 keV electrons s-1); this number of reconnection sites can easily fit within the estimated 3 x 10(9) cm span of the overall current-sheet dissipation region formed in these large flares. We therefore conclude that MHD turbulent cascade is a promising mechanism for the plasma energization observed in the impulsive phase of solar flares. RP LAROSA, TN (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812, USA. NR 63 TC 54 Z9 54 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 1993 VL 418 IS 2 BP 912 EP 918 DI 10.1086/173448 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MJ035 UT WOS:A1993MJ03500034 ER PT J AU PILEWSKIE, P VALERO, FPJ AF PILEWSKIE, P VALERO, FPJ TI OPTICAL DEPTHS AND HAZE PARTICLE SIZES DURING AGASP-III SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE AEROSOLS; OPTICAL DEPTH; PARTICLE SIZE SPECTRUM; ARCTIC HAZE ID ARCTIC HAZE; SOLAR-RADIATION; ABSORPTION; BARROW AB The optical properties of Arctic Haze were studied using a total-direct-diffuse radiometer as part of the Arctic Gas and Aerosol Sampling Project, part III (AGASP III). The radiometer was installed on the NOAA WP-3D research aircraft and measured solar downwelling irradiance in seven narrow-band channels in the visible and near-infra-red. Haze optical depths had maximum values near 0.1 in the mid-visible for AGASP flights 310 and 311. An inferred particle size spectrum from flight 311 extinction measurements showed two dominant modes near 0.1 and 0.8 mu m. A method of retrieving the angular dependence of scattered radiation is presented and suggests the presence of thin cirrus. RP PILEWSKIE, P (reprint author), NASA,AMES RES CTR,ATMOSPHER PHYS RES BRANCH,MS 245-4,MOFFETT FIELD,CA 94035, USA. NR 12 TC 5 Z9 5 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PD DEC PY 1993 VL 27 IS 17-18 BP 2895 EP 2899 DI 10.1016/0960-1686(93)90320-X PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA MP871 UT WOS:A1993MP87100019 ER PT J AU SCHUBERT, SD ROOD, RB PFAENDTNER, J AF SCHUBERT, SD ROOD, RB PFAENDTNER, J TI AN ASSIMILATED DATASET FOR EARTH-SCIENCE APPLICATIONS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID PARAMETERIZATION; ABSORPTION; EQUATIONS; MODELS AB The Data Assimilation Office at NASA's Goddard Space Flight Center is currently producing a multiyear gridded global atmospheric dataset for use in climate research, including tropospheric chemistry applications. The data, which are being made available to the scientific community, are well suited for climate research since they are produced by a fixed assimilation system designed to minimize the spin up in the hydrological cycle. By using a nonvarying system, the variability due to algorithm change is eliminated and geophysical variability can be more confidently isolated. The analysis incorporates rawinsonde reports, satellite retrievals of geopotential thickness, cloud-motion winds, and aircraft, ship, and rocketsonde reports. At the lower boundary, the assimilating atmospheric general circulation model is constrained by the observed sea surface temperature and soil moisture derived from observed surface air temperature and precipitation fields. The available output data include all prognostic variables and a large number of diagnostic quantities such as heating rates, precipitation, surface fluxes, cloud fraction, and the height of the planetary boundary layer. These variables were chosen to assure a complete budget of the energy and moisture cycles. The assimilated data should also be useful for estimating transport by cumulus processes. The analysis increments (observation minus first guess) and the estimated analysis errors are provided to help the user assess the quality of the data. All quantities are made available every 6 h at the full resolution of the assimilating general circulation model. Selected surface quantities are made available every 3 h. RP SCHUBERT, SD (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ATMOSPHER LAB, DATA ASSIMILAT OFF, GREENBELT, MD 20771 USA. RI Rood, Richard/C-5611-2008 OI Rood, Richard/0000-0002-2310-4262 NR 33 TC 418 Z9 422 U1 1 U2 11 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 1993 VL 74 IS 12 BP 2331 EP 2342 DI 10.1175/1520-0477(1993)074<2331:AADFES>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MM614 UT WOS:A1993MM61400002 ER PT J AU LIGHTFOOT, JT ROWE, SA FORTNEY, SM AF LIGHTFOOT, JT ROWE, SA FORTNEY, SM TI OCCURRENCE OF PRESYNCOPE IN SUBJECTS WITHOUT VENTRICULAR INNERVATION SO CLINICAL SCIENCE LA English DT Article DE CARDIAC TRANSPLANT; C-FIBERS; LOWER BODY NEGATIVE PRESSURE; MECHANORECEPTORS; SYNCOPE ID ORTHOTOPIC CARDIAC TRANSPLANTATION; HEART-RATE-VARIABILITY; SENSORY REINNERVATION; VASOVAGAL SYNCOPE; HEMORRHAGE; RESPONSES; EXERCISE AB 1. To determine whether activation of the left ventricular C-fibre mechanoreceptors initiates the vasodepressor reflex that often causes syncope, we exposed six orthotopic cardiac transplant patients and six matched, healthy control subjects to progressively increasing lower body negative pressure until the onset of vasodepressor responses. 2. There was no significant difference (P=0.78) between the central hypovolaemia tolerances of the cardiac transplant and the control groups. 3. The decrease in systolic blood pressure before the onset of vasodepressor reflexes was greater in the cardiac transplant group. The cardiac transplant group did not maintain diastolic blood pressure during central hypovolaemia. From baseline to the onset of vasodepression, there were no differences in leg circumference, forearm blood flow and forearm vascular resistance responses between the two groups. 4. We conclude that the left ventricular mechanoreceptors may not be the primary afferent trigger for syncope. C1 JOHNS HOPKINS MED INST,BALTIMORE,MD 21205. UNIV NEW MEXICO,CHILDRENS HOSP,DEPT PEDIAT,ALBUQUERQUE,NM 87131. NASA,LYNDON B JOHNSON SPACE CTR,SPACE BIOMED RES INST,HOUSTON,TX 77058. RP LIGHTFOOT, JT (reprint author), FLORIDA ATLANTIC UNIV,TEACHING GYMNASIUM,HUMAN PERFORMANCE LAB,BOCA RATON,FL 33431, USA. FU NHLBI NIH HHS [HL10342, HL07534] NR 32 TC 35 Z9 35 U1 1 U2 3 PU PORTLAND PRESS PI LONDON PA 59 PORTLAND PLACE, LONDON, ENGLAND W1N 3AJ SN 0143-5221 J9 CLIN SCI JI Clin. Sci. PD DEC PY 1993 VL 85 IS 6 BP 695 EP 700 PG 6 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA MM291 UT WOS:A1993MM29100005 PM 8287661 ER PT J AU LITVIN, FL CHEN, NX ZHANG, Y KRENZER, TJ HANDSCHUH, RF AF LITVIN, FL CHEN, NX ZHANG, Y KRENZER, TJ HANDSCHUH, RF TI COMPUTERIZED GENERATION OF SURFACES WITH OPTIMAL APPROXIMATION TO IDEAL SURFACES SO COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING LA English DT Article AB The authors propose a new method for generation (by grinding or cutting) of a surface (Sigma(g)) with the optimal approximation to the theoretical (ideal) surface (Sigma(p)). The method is based on the following ideas: (1) A region of space is swept out by the tool surface Sigma(t) performing certain motions with respect to Sigma(p). The surface of the tool (as grinding wheel or cutter) is a surface of revolution with a circular are in axial section, and a circular cone in particular cases. (2) The space swept out by Sigma(t) is considered as a family of surfaces Sigma(t), and the envelope to this family is surface Sigma(g) (generated surface) that must be in optimal approximation to the theoretical surface Sigma(p). (3) The continuous varied setting and orientation of Sigma(t) with respect to Sigma(p) are executed by a multi-degree-of-freedom machine, that is a computer numerical controlled (CNC) machine. The approach developed can be applied for grinding of face-gears, helical involute gears with modified topology, ruled undeveloped surfaces and others. An example of application is considered. C1 UNIV MICHIGAN,DEARBORN,MI 48128. GLEASON WORKS,ROCHESTER,NY. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP LITVIN, FL (reprint author), UNIV ILLINOIS,DEPT MECH ENGN,M-C 251,2039 ENGN RES FACIL,CHICAGO,IL 60680, USA. NR 5 TC 9 Z9 10 U1 0 U2 0 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 PY 1993 VL 110 IS 1-2 BP 39 EP 55 DI 10.1016/0045-7825(93)90018-S PG 17 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications; Mechanics SC Engineering; Mathematics; Mechanics GA MP829 UT WOS:A1993MP82900004 ER PT J AU PRICE, CC SALAMA, M AF PRICE, CC SALAMA, M TI OPTIMAL TASK ALLOCATION IN HYPERCUBE MULTIPROCESSOR ENSEMBLES SO COMPUTERS & MATHEMATICS WITH APPLICATIONS LA English DT Article DE SCHEDULING; MULTIPROCESSORS; COMPUTER SYSTEM DESIGN; TASK ALLOCATION; INTERTASK COMMUNICATION ID ALGORITHMS AB Criteria are established to determine the optimal policy for allocating a set of uniform tasks onto a multiprocessor hypercube ensemble. It is shown that the optimal policy depends on the ratio of computation to intertask communication required by the distributed program, and that based on this ratio, tasks should be placed either all on one processor or uniformly distributed over the largest possible hypercube. C1 JET PROP LAB,PASADENA,CA 91109. RP PRICE, CC (reprint author), STEPHEN F AUSTIN STATE UNIV,DEPT COMP SCI,NACOGDOCHES,TX 75962, USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0898-1221 J9 COMPUT MATH APPL JI Comput. Math. Appl. PD DEC PY 1993 VL 26 IS 12 BP 17 EP 24 DI 10.1016/0898-1221(93)90055-Z PG 8 WC Computer Science, Interdisciplinary Applications; Mathematics, Applied SC Computer Science; Mathematics GA ME323 UT WOS:A1993ME32300003 ER PT J AU SALERNO, LJ KITTEL, P SPIVAK, AL AF SALERNO, LJ KITTEL, P SPIVAK, AL TI THERMAL CONDUCTANCE OF AUGMENTED PRESSED METALLIC CONTACTS AT LIQUID-HELIUM TEMPERATURES SO CRYOGENICS LA English DT Article DE PRESSED CONTACTS; THERMAL CONDUCTANCE; LIQUID HELIUM AB The thermal conductance of uncoated OFHC copper, 6061 - T6 aluminium, free-machining brass and 304 stainless steel sample pairs which have been augmented with a gold coated 6061 - T6 aluminium washer inserted between the contact surfaces has been measured over the temperature range 1.6-6.0 K, with applied forces from 22 to 670 N. The contact surfaces of the sample pairs were prepared with a 0.8 mum lapped finish, while the finish of the aluminium washer was 0.2 mum lapped. The contribution to the overall thermal impedance of the bulk conductance of the aluminium washer was negligible. It was found that conductance increased with both force and temperature; however, addition of the washer offered no significant conductance improvement over an uncoated single contact pair, any benefits from the gold plated washer being used to counteract the addition of two more contact surfaces. Additionally, the thermal conductance of a 'combination' aluminium sample pair having one gold coated and one uncoated surface was measured and compared to the augmented aluminium pair. The ratio of the conductance of the augmented aluminium pair to half the conductance of the 'combination' sample pair was found to be constant and near unity over the temperature range of the data obtained, within the limits of experimental error. C1 TRANS BAY ELECTR,RICHMOND,CA 94084. RP SALERNO, LJ (reprint author), NASA,AMES RES CTR,MAIL STOP 244-19,MOFFETT FIELD,CA 94035, USA. NR 6 TC 7 Z9 7 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD DEC PY 1993 VL 33 IS 12 BP 1104 EP 1109 DI 10.1016/0011-2275(93)90002-6 PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA MJ211 UT WOS:A1993MJ21100002 ER PT J AU CONVERTINO, VA MATHES, KL LASLEY, ML TOMASELLI, CM FREY, MAB HOFFLER, GW AF CONVERTINO, VA MATHES, KL LASLEY, ML TOMASELLI, CM FREY, MAB HOFFLER, GW TI HEMODYNAMIC AND HORMONAL RESPONSES TO LOWER-BODY NEGATIVE-PRESSURE IN MEN WITH VARYING PROFILES OF STRENGTH AND AEROBIC POWER SO EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY LA English DT Article DE BLOOD PRESSURE CONTROL; FLUID SHIFTS; BLOOD VOLUME; CARDIAC OUTPUT; HEAD-DOWN TILT ID ORTHOSTATIC INTOLERANCE; CARDIOVASCULAR-RESPONSE; TOLERANCE; FITNESS; VASOPRESSIN; ENDURANCE; CAPACITY; HUMANS; VOLUME; STRESS AB Hemodynamic, cardiac, and hormonal responses to lower-body negative pressure (LBNP) were examined in 24 healthy men to test the hypothesis that responsiveness of reflex control of blood pressure during orthostatic challenge is associated with interactions between strength and aerobic power. Subjects underwent treadmill tests to determine peak oxygen uptake (VO2max) and isokinetic dynamometer tests to determine knee extensor strength. Based on predetermined criteria, subjects were classified into one of four fitness profiles of six subjects each, matched for age, height, and body mass: (a) low strength/average aerobic fitness, (b) low strength/high aerobic fitness, (c) high strength/average aerobic fitness, and (d) high strength/high aerobic fitness. Following 90 min of 0.11 rad (6 degrees) head-down tilt (HDT), each subject underwent graded LBNP to -6.7 kPa or presyncope, with maximal duration 15 min, while hemodynamic, cardiac, and hormonal responses were measured. All groups exhibited typical hemodynamic, hormonal, and fluid shift responses during LBNP, with no intergroup differences between high and low strength characteristics. Subjects with high aerobic power exhibited greater (P<0.05) stroke volume and lower (P<0.05) heart rate, vascular pe ripheral resistance, and mean arterial pressure during rest, HDT, and LBNP. Seven subjects, distributed among the four fitness profiles, became presyncopal. These subjects showed greatest reduction in mean arterial pressure during LBNP, had greater elevations in vasopressin, and lesser increases in heart rate and peripheral resistance. Neither VO2max nor leg strength were associated with fall in arterial pressure or with syncopal episodes. We conclude that interactions between aerobic and strength fitness characteristics do not influence responses to LBNP challenge. C1 NASA,BIOMED OPERAT & RES OFF,KENNEDY SPACE CTR,FL 32899. BIONET CORP,KENNEDY SPACE CTR,FL 32899. NR 34 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0301-5548 J9 EUR J APPL PHYSIOL O JI Eur. J. Appl. Physiol. Occup. Physiol. PD DEC PY 1993 VL 67 IS 6 BP 492 EP 498 DI 10.1007/BF00241644 PG 7 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA MP147 UT WOS:A1993MP14700003 PM 8149927 ER PT J AU CONVERTINO, VA TATRO, DL ROGAN, RB AF CONVERTINO, VA TATRO, DL ROGAN, RB TI RENAL AND CARDIOVASCULAR-RESPONSES TO WATER IMMERSION IN TRAINED RUNNERS AND SWIMMERS SO EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY LA English DT Article DE DIURESIS; NATRIURESIS; HYPOGRAVITY; EXERCISE TRAINING; RENAL FUNCTION ID INDUCED HYPERVOLEMIA; PLASMA-VOLUME; EXERCISE; VASOPRESSIN; RENIN; SUPPRESSION; OSMOLALITY; HUMANS AB The purpose of this study was to determine if fluid-electrolyte, renal, hormonal, and cardiovascular responses during and after multi-hour water immersion were associated with aerobic training. Additionally, we compared these responses in those who trained in a hypogravic versus a 1-g environment. Seventeen men comprised three similarly aged groups: six long-distance runners, five competitive swimmers, and six untrained control subjects. Each subject underwent 5 h of immersion in water [mean (SE)] 36.0 (0.5)degrees C to the neck. Immediately before and at each hour of immersion, blood and urine samples were collected and analyzed for sodium (Na), potassium, osmolality, and creatinine (Cr). Plasma antidiuretic hormone and aldosterone were also measured. Hematocrits were used to calculate relative changes in plasma volume (%Delta V-pl). Heart rate response to submaximal cycle ergometer exercise (35% peak oxygen uptake) was measured before and after water immersion. Water immersion induced significant increases in urine flow, Na clearance (C-Na), and a 3-5% decrease in V-pl. Urine flow during immersion was greater (P<0.05) in runners [2.4 (0.4) ml.min(-1)] compared to controls [1.3 (0.1) ml.min(-1)]. However, %Delta V-pl, C-Cr, C-Na and C-H2O during immersion were not different (P>0.05) between runners, swimmers, and controls. After 5h of immersion, there was an increase (P<0.05) in submaximal exercise heart rate of 9 (3) and 10 (3) beats.min(-1) in both runners and controls, respectively, but no change (P>0.05) was observed in swimmers. Since swimmers did not experience elevated exercise tachycardia following water immersion compared to runners and sedentary controls, we conclude that exercise training in a hypogravic environment attenuates the acute cardiovascular adaption to microgravity. This effect of hypogravic aerobic training was not associated with the degree of hypovolemia and associated diuresis and natriuresis. C1 NASA,BIOMED OPERAT & RES OFF,KENNEDY SPACE CTR,FL 32899. BIONET CORP,KENNEDY SPACE CTR,FL 32899. UNIV ARIZONA,EXERCISE & SPORTS SCI LAB,TUCSON,AZ 85721. NR 15 TC 14 Z9 15 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0301-5548 J9 EUR J APPL PHYSIOL O JI Eur. J. Appl. Physiol. Occup. Physiol. PD DEC PY 1993 VL 67 IS 6 BP 507 EP 512 DI 10.1007/BF00241646 PG 6 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA MP147 UT WOS:A1993MP14700005 PM 8149929 ER PT J AU KRISHER, TP AF KRISHER, TP TI A NEW TEST OF THE EQUIVALENCE PRINCIPLE - A NULL PHASE-DELAY EXPERIMENT SO GENERAL RELATIVITY AND GRAVITATION LA English DT Article ID ONE-WAY SPEED; FREQUENCY STANDARD; HYDROGEN-MASER; ISOTROPY; LIGHT AB The Einstein Equivalence Principle (EEP) provides the fundamental basis for any metric theory of gravity, such as general relativity. It implies that the only observable effects of gravitation are those mediated by the spacetime metric. Therefore, at the origin of a local freely falling frame there should be no observable effects of gravity. Null redshift tests pro-vide an interesting way to test this prediction. In this test, the frequencies of two oscillators of a different type are compared at the same location in a gravitational field as the field is varied. Any variation in the frequency would signal a violation of the EEP. Here we shall propose a new test of the EEP called a null phase-delay experiment, in which the phase-delay of a signal propagated over a coil of optical fiber is monitored as the gravitational field at the coil is varied. An interesting test of the EEP in the solar gravitational field can be performed in the laboratory under carefully controlled conditions. With presently available technology, such an experiment could provide a 0.01% test. RP KRISHER, TP (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0001-7701 J9 GEN RELAT GRAVIT JI Gen. Relativ. Gravit. PD DEC PY 1993 VL 25 IS 12 BP 1219 EP 1223 DI 10.1007/BF00759030 PG 5 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA MJ873 UT WOS:A1993MJ87300002 ER PT J AU POTTER, CS RANDERSON, JT FIELD, CB MATSON, PA VITOUSEK, PM MOONEY, HA KLOOSTER, SA AF POTTER, CS RANDERSON, JT FIELD, CB MATSON, PA VITOUSEK, PM MOONEY, HA KLOOSTER, SA TI TERRESTRIAL ECOSYSTEM PRODUCTION - A PROCESS MODEL-BASED ON GLOBAL SATELLITE AND SURFACE DATA SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID SOIL ORGANIC-MATTER; HIGH-RESOLUTION RADIOMETER; MICROBIAL BIOMASS; VEGETATION INDEX; CANOPY REFLECTANCE; CO2 CONCENTRATIONS; SOLAR-RADIATION; TROPICAL SOILS; CLIMATE CHANGE; PARTICLE-SIZE AB This paper presents a modeling approach aimed at seasonal resolution of global climatic and edaphic controls on patterns of terrestrial ecosystem production and soil microbial respiration. We use satellite imagery (Advanced Very High Resolution Radiometer and International Satellite Cloud Climatology Project solar radiation), along with historical climate (monthly temperature and precipitation) and soil attributes (texture, C and N contents) from global (1-degrees) data sets as model inputs. The Carnegie-Ames-Stanford approach (CASA) Biosphere model runs on a monthly time interval to simulate seasonal patterns in net plant carbon fixation, biomass and nutrient allocation, litterfall, soil nitrogen mineralization, and microbial CO2 production. The model estimate of global terrestrial net primary production is 48 Pg C yr-1 with a maximum light use efficiency of 0.39 g C MJ-1 PAR. Over 70% of terrestrial net production takes place between 30-degrees-N and 30-degrees-S latitude. Steady state pools of standing litter represent global storage of around 174 Pg C (94 and 80 Pg C in nonwoody and woody pools, respectively), whereas the pool of soil C in the top 0.3 m that is turning over on decadal time scales comprises 300 Pg C. Seasonal variations in atmospheric CO2 concentrations from three stations in the Geophysical Monitoring for Climate Change Flask Sampling Network correlate significantly with estimated net ecosystem production values averaged over 50-degrees-80-degrees-N, 10-degrees-30-degrees-N, and 0-degrees-10-degrees-N. C1 CARNEGIE INST WASHINGTON, DEPT PLANT BIOL, STANFORD, CA 94305 USA. STANFORD UNIV, DEPT BIOL SCI, STANFORD, CA 94305 USA. RP POTTER, CS (reprint author), NASA, AMES RES CTR, JOHNSON CONTROLS, MOFFETT FIELD, CA 94035 USA. NR 111 TC 1136 Z9 1415 U1 36 U2 308 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD DEC PY 1993 VL 7 IS 4 BP 811 EP 841 DI 10.1029/93GB02725 PG 31 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA MM234 UT WOS:A1993MM23400006 ER PT J AU DANTONI, HL AF DANTONI, HL TI PALEOTEMPERATURES OF LA MALINCHE - A PALYNOLOGICAL HYPOTHESIS SO GRANA LA English DT Article AB Paleotemperatures of the fast 10,000 years at 3.100 m elevation on La Malinche volcano (Mexico) were reconstructed by treating pollen analytic data by Ohngemach and Straka with numerical techniques. Pollen data from 104 modern and 97 fossil samples were analyzed in order to: (1) calibrate transfer functions linking modern pollen data to climate and vegetation data from available maps (and cross-validate the predictive model of temperature on modern data sets), and (2) reconstruct paleotemperature for the last 10,000 years from fossil pollen data. A paleotemperature curve was obtained, that ranges between 7 degrees C in the glacial period and 12.5 degrees C at 8,000 years BP. It matches glacial stratigraphy. Temperature is described as follows: Section S1 (from the deposit's bottom to 8,500 years BP) from 7 to 8 degrees C. S2 from 9.0 to 11 degrees C. S3 (around 8,000 years BP) 11.5-12.5 degrees C. S4 from 12 to 9 degrees C. S5 (2,700 years BP) has poor pollen concentration and estimates are unreliable. S6 from 9 to 5.5 degrees C. S7 (around 1,550 years BP) from 6.5 to 7.5 degrees C; S8(ending 1,000 years BP), from 7.5 to 9.5 degrees C and includes anthropogenic influences. S6 is given a new interpretation: open vegetation with low local pollen production and greater influence of Long distance components. RP DANTONI, HL (reprint author), NASA,AMES RES CTR,DIV EARTH SYST SCI,ECOSYST SCI & TECHNOL BRANCH,MS 2424,MOFFETT FIELD,CA 94035, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SCANDINAVIAN UNIVERSITY PRESS PI OSLO PA PO BOX 2959 TOYEN, JOURNAL DIVISION CUSTOMER SERVICE, N-0608 OSLO, NORWAY SN 0017-3134 J9 GRANA JI Grana PD DEC PY 1993 VL 32 IS 6 BP 354 EP 358 PG 5 WC Plant Sciences SC Plant Sciences GA MR466 UT WOS:A1993MR46600007 ER PT J AU BEGAULT, DR AF BEGAULT, DR TI HEAD-UP AUDITORY DISPLAYS FOR TRAFFIC COLLISION-AVOIDANCE SYSTEM ADVISORIES - A PRELIMINARY INVESTIGATION SO HUMAN FACTORS LA English DT Article AB The advantage of a head-up auditory display was evaluated in a preliminary experiment designed to measure and compare the acquisition time for capturing visual targets under two auditory conditions: standard one-earpiece presentation and two-earpiece three-dimensional (3D) audio presentation. Twelve commercial airline crews were tested under full mission simulation conditions at the NASA-Ames Man-Vehicle Systems Research Facility advanced concepts flight simulator. Scenario software generated visual targets corresponding to aircraft that would activate a traffic collision avoidance system (TCAS) aural advisory; the spatial auditory position was linked to the visual position with 3D audio presentation. Results showed that crew members using a 3D auditory display acquired targets approximately 2.2 s faster than did crew members who used one-earpiece head-sets, but there was no significant difference in the number of targets acquired. RP BEGAULT, DR (reprint author), NASA,MOFFETT FIELD,CA 94035, USA. NR 15 TC 39 Z9 39 U1 4 U2 11 PU HUMAN FACTORS SOC PI SANTA MONICA PA BOX 1369, SANTA MONICA, CA 90406 SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD DEC PY 1993 VL 35 IS 4 BP 707 EP 717 PG 11 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA NA405 UT WOS:A1993NA40500009 PM 8163283 ER PT J AU GOLDSPIEL, JM SQUYRES, SW SLADE, MA JURGENS, RF ZISK, SH AF GOLDSPIEL, JM SQUYRES, SW SLADE, MA JURGENS, RF ZISK, SH TI RADAR-DERIVED TOPOGRAPHY OF LOW SOUTHERN LATITUDES OF MARS SO ICARUS LA English DT Article ID MARTIAN TOPOGRAPHY; SURFACE PROPERTIES; IMPACT CRATERS; ORIGIN; HISTORY; PLANETS; MOON C1 NASA,JET PROP LAB,PASADENA,CA 91109. UNIV HAWAII,DEPT GEOL & GEOPHYS,HONOLULU,HI 96822. RP GOLDSPIEL, JM (reprint author), CORNELL UNIV,CTR RADIOPHYS & SPACE RES,ITHACA,NY 14853, USA. NR 36 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 1993 VL 106 IS 2 BP 346 EP 364 DI 10.1006/icar.1993.1177 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MR604 UT WOS:A1993MR60400001 ER PT J AU ROMANI, PN BISHOP, J BEZARD, B ATREYA, S AF ROMANI, PN BISHOP, J BEZARD, B ATREYA, S TI METHANE PHOTOCHEMISTRY ON NEPTUNE - ETHANE AND ACETYLENE MIXING RATIOS AND HAZE PRODUCTION SO ICARUS LA English DT Article ID GRAVITY-WAVE; ATMOSPHERE; OCCULTATION; TEMPERATURE; OBLATENESS; VOYAGER-2; HYDROGEN; PRESSURE; TRITON; SYSTEM C1 COMPUTAT PHYS INC,FAIRFAX,VA 22031. OBSERV PARIS,DEPT RECH SPATIALE,F-92195 MEUDON,FRANCE. UNIV MICHIGAN,DEPT ATMOSPHER OCEAN & SPACE SCI,ANN ARBOR,MI 48109. RP ROMANI, PN (reprint author), NASA,GODDARD SPACE FLIGHT CTR,MAIL CODE 693,GREENBELT,MD 20771, USA. RI Romani, Paul/D-2729-2012 NR 47 TC 74 Z9 74 U1 0 U2 3 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 1993 VL 106 IS 2 BP 442 EP 463 DI 10.1006/icar.1993.1184 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MR604 UT WOS:A1993MR60400008 ER PT J AU SANDFORD, SA ALLAMANDOLA, LJ AF SANDFORD, SA ALLAMANDOLA, LJ TI THE CONDENSATION AND VAPORIZATION BEHAVIOR OF ICES CONTAINING SO2, H2S, AND CO2 - IMPLICATIONS FOR LO SO ICARUS LA English DT Article ID INFRARED-SPECTROSCOPY; TENTATIVE IDENTIFICATION; SPECTRA; IO; METHANOL; CLUSTERS; ANALOGS; DIOXIDE; CLOUDS; BAND RP SANDFORD, SA (reprint author), NASA,AMES RES CTR,MAIL STOP 245-6,MOFFETT FIELD,CA 94035, USA. NR 43 TC 44 Z9 44 U1 0 U2 3 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 1993 VL 106 IS 2 BP 478 EP 488 DI 10.1006/icar.1993.1186 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MR604 UT WOS:A1993MR60400010 PM 11539120 ER PT J AU GAFFEY, MJ BELL, JF BROWN, RH BURBINE, TH PIATEK, JL REED, KL CHAKY, DA AF GAFFEY, MJ BELL, JF BROWN, RH BURBINE, TH PIATEK, JL REED, KL CHAKY, DA TI MINERALOGICAL VARIATIONS WITHIN THE S-TYPE ASTEROID CLASS SO ICARUS LA English DT Review ID ORDINARY CHONDRITES; PARENT BODIES; CARBONACEOUS CHONDRITES; REFLECTANCE SPECTRA; METEORITES; SPECTROPHOTOMETRY; ORIGIN; PLANETESIMALS; FRAGMENTS; TAXONOMY C1 UNIV HAWAII,SOEST,DEPT GEOL & GEOPHYS,DIV PLANETARY GEOSCI,HONOLULU,HI 96822. JET PROP LAB,PASADENA,CA 91109. RP GAFFEY, MJ (reprint author), RENSSELAER POLYTECH INST,DEPT EARTH & ENVIRONM SCI,WEST HALL,TROY,NY 12180, USA. RI Piatek, Jaroslaw/A-9775-2015 NR 119 TC 325 Z9 327 U1 3 U2 9 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 1993 VL 106 IS 2 BP 573 EP 602 DI 10.1006/icar.1993.1194 PG 30 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MR604 UT WOS:A1993MR60400018 ER PT J AU TONCICH, SS COLLIN, RE BHASIN, KB AF TONCICH, SS COLLIN, RE BHASIN, KB TI FULL-WAVE CHARACTERIZATION OF MICROSTRIP OPEN-END DISCONTINUITIES PATTERNED ON ANISOTROPIC SUBSTRATES USING POTENTIAL-THEORY SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article AB A technique for the full-wave characterization of microstrip discontinuities fabricated on uniaxial anisotropic substrates using a dynamic source reversal method based on potential theory is presented. The dynamic source reversal technique was introduced in 1989 by R. E. Collin and S. S. Toncich [1]. The open end discontinuity is enclosed in a cut-off waveguide of infinite extent, with the anisotropic axis aligned perpendicular to the air-dielectric interface. A full description of the sources on the microstrip line is included with proper edge conditions built in. The resulting computer program is written in compiled BASIC and is intended for execution on personal computers possessing minimal memory and/or processing resources. Extension to other discontinuities is discussed. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. CASE WESTERN RESERVE UNIV,DEPT ELECT & APPL PHYS,CLEVELAND,OH 44106. NR 10 TC 5 Z9 5 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 1993 VL 41 IS 12 BP 2067 EP 2073 DI 10.1109/22.260688 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA MW877 UT WOS:A1993MW87700004 ER PT J AU BUEHLER, MG BLAES, BR SOLI, GA TARDIO, GR AF BUEHLER, MG BLAES, BR SOLI, GA TARDIO, GR TI ON-CHIP P-MOSFET DOSIMETRY SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE 30th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 19-23, 1993 CL SNOWBIRD, UT SP IEEE, NUCL & PLASMA SCI SOC, RADIAT EFFECTS COMM, US DEPT DEF, DEF NUCL AGCY, US DEF ENERGY ENERGY, SANDIA NATL LAB, NASA, JET PROPULS LAB ID RADIATION AB On-chip p-FETs were developed to monitor the radiation dose of n-well CMOS ICs by monitoring threshold voltage shifts due to radiation induced oxide and interface charge. The design employs closed geometry FETs and a zero-biased n-well to eliminate leakage currents. The FETs are operated using a constant current chosen to greatly reduce the FET's temperature sensitivity. The dose sensitivity of these p-FETs is about -2.6 mV/krad(Si) and the off-chip instrumentation resolves about 400 rad(Si)/bit. When operated with a current at the temperature-independent point, it was discovered that the pre-irradiation output voltage is about -1.5 V which depends only on design-independent silicon material parameters. The temperature sensitivity is less than 63 mu V/degrees C over a 70 degrees C temperature range centered about the temperature insensitive point. RP BUEHLER, MG (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 9 TC 46 Z9 46 U1 0 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 1993 VL 40 IS 6 BP 1442 EP 1449 DI 10.1109/23.273520 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA MV375 UT WOS:A1993MV37500024 ER PT J AU CUMMINGS, JR CUMMINGS, AC MEWALDT, RA SELESNICK, RS STONE, EC VONROSENVINGE, TT BLAKE, JB AF CUMMINGS, JR CUMMINGS, AC MEWALDT, RA SELESNICK, RS STONE, EC VONROSENVINGE, TT BLAKE, JB TI SAMPEX MEASUREMENTS OF HEAVY-IONS TRAPPED IN THE MAGNETOSPHERE SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE 30th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 19-23, 1993 CL SNOWBIRD, UT SP IEEE, NUCL & PLASMA SCI SOC, RADIAT EFFECTS COMM, US DEPT DEF, DEF NUCL AGCY, US DEF ENERGY ENERGY, SANDIA NATL LAB, NASA, JET PROPULS LAB AB New observations of >15 MeV/nuc trapped heavy ions with Z greater than or equal to 2 have been made by the SAMPEX spacecraft in low polar orbit. The composition of these ions, which are located primarily around L = 2, is dominated by He, N, O, and Ne. The N, O, and Ne ions are apparently trapped ''anomalous cosmic rays,'' while the origin of the trapped He flux is presently uncertain. These ions can affect the rate of single-event upsets (SEUs) in spacecraft hardware. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. AEROSP CORP,LOS ANGELES,CA 90009. RP CUMMINGS, JR (reprint author), CALTECH,PASADENA,CA 91125, USA. NR 21 TC 4 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 1993 VL 40 IS 6 BP 1458 EP 1462 DI 10.1109/23.273518 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA MV375 UT WOS:A1993MV37500026 ER PT J AU LABEL, KA MARSHALL, P DALE, C CRABTREE, CM STASSINOPOULOS, EG MILLER, JT GATES, MM AF LABEL, KA MARSHALL, P DALE, C CRABTREE, CM STASSINOPOULOS, EG MILLER, JT GATES, MM TI SEDS MIL-STD-1773 FIBER OPTIC DATA BUS - PROTON IRRADIATION TEST-RESULTS AND SPACEFLIGHT SEU DATA SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE 30th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 19-23, 1993 CL SNOWBIRD, UT SP IEEE, NUCL & PLASMA SCI SOC, RADIAT EFFECTS COMM, US DEPT DEF, DEF NUCL AGCY, US DEF ENERGY ENERGY, SANDIA NATL LAB, NASA, JET PROPULS LAB AB We present proton test and space flight single event effect data for NASA's first fiber optic data bus. Bit error rate predictions based on a new proton direct ionization. model agree well with flight data for proton belt and solar flare effects. C1 NRL,SFA,WASHINGTON,DC. HUGHES ST SYST CORP,SEABROOK,MD. JACKSON & TULL,SEABROOK,MD. RP LABEL, KA (reprint author), NASA,GSFC,GREENBELT,MD 20771, USA. NR 5 TC 19 Z9 19 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 1993 VL 40 IS 6 BP 1638 EP 1644 DI 10.1109/23.273554 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA MV375 UT WOS:A1993MV37500051 ER PT J AU JOHNSTON, AH AF JOHNSTON, AH TI CHARGE GENERATION AND COLLECTION IN P-N-JUNCTIONS EXCITED WITH PULSED INFRARED-LASERS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID NONLINEAR REFRACTION; ABSORPTION; SILICON; DEVICES; GAAS; SEU AB Optical absorption processes are examined for applications of infrared lasers to simulate single-particle effects in silicon and GaAs, which require that the laser is focused to a small area on the device surface. The resulting charge generation is compared with charge generation from heavy ions. Charge funneling is reduced in silicon structures because of the lower charge density unless the LET is above a threshold value. In both materials, the effective LET of a laser is inherently non-linear because of nonlinear absorption at high intensities. These factors limit quantitative comparisons between lasers and heavy ions, and are increasingly important as devices are scaled to smaller dimensions. RP CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. NR 22 TC 47 Z9 52 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1993 VL 40 IS 6 BP 1694 EP 1702 DI 10.1109/23.273491 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA MV375 UT WOS:A1993MV37500058 ER PT J AU ROTH, DR MCNULTY, PJ ABDELKADER, WG STRAUSS, L STASSINOPOULOS, EG AF ROTH, DR MCNULTY, PJ ABDELKADER, WG STRAUSS, L STASSINOPOULOS, EG TI MONITORING SEU PARAMETERS AT REDUCED BIAS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE 30th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 19-23, 1993 CL SNOWBIRD, UT SP IEEE, NUCL & PLASMA SCI SOC, RADIAT EFFECTS COMM, US DEPT DEF, DEF NUCL AGCY, US DEF ENERGY ENERGY, SANDIA NATL LAB, NASA, JET PROPULS LAB AB SEU sensitivity of a CMOS SRAM increases with decreasing bias in such a manner that the critical charge exhibits a linear dependence on bias. This should allow proton and neutron monitoring of SEU parameters even for radiation hardened devices. The sensitivity of SEU rates to the thickness of the. sensitive volume is demonstrated and procedures for determining the SEU parameters using protons are outlined. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP ROTH, DR (reprint author), CLEMSON UNIV,DEPT PHYS & ASTRON,CLEMSON,SC 29634, USA. NR 8 TC 20 Z9 22 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 1993 VL 40 IS 6 BP 1721 EP 1724 DI 10.1109/23.273487 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA MV375 UT WOS:A1993MV37500062 ER PT J AU ZHANG, ZX GRANATSTEIN, VL DESTLER, WW BIDWELL, SW RODGERS, J CHENG, S ANTONSEN, TM LEVUSH, B RADACK, DJ AF ZHANG, ZX GRANATSTEIN, VL DESTLER, WW BIDWELL, SW RODGERS, J CHENG, S ANTONSEN, TM LEVUSH, B RADACK, DJ TI EXPERIMENTAL AND NUMERICAL-STUDIES OF SHEET ELECTRON-BEAM PROPAGATION THROUGH A PLANAR WIGGLER MAGNET SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB Detailed experimental studies on sheet relativistic electron beam propagation through a long planar wiggler are reported and compared with numerical simulations. The planar wiggler has 56 periods with a period of 9.6 mm. Typically, the wiggler field peak amplitude is 5 kG. The experimental efforts have been focused on control of the deviation of the beam toward the side edge of the planar wiggler along the wide transverse direction. It is found that a suitably tapered magnetic field configuration at the wiggler entrance can considerably reduce the rate of the deviation. The,effects of the following techniques on beam transport efficiency are also discussed: side focusing, beam transverse velocity tuning at the wiggler entrance, and beam spread limiting; High beam transport efficiency (almost 100%) of a 15 A beam has been obtained in some cases. The results are relevant to development of a free electron laser amplifier for application to stabilizing and heating of plasma in magnetic fusion research. C1 UNIV MARYLAND,DEPT ELECT ENGN,COLL PK,MD 20742. NASA,GODDARD SPACE FLIGHT CTR,HYDROSPHER PROC LAB,GREENBELT,MD 20771. RP ZHANG, ZX (reprint author), UNIV MARYLAND,PLASMA RES LAB,COLL PK,MD 20742, USA. RI Antonsen, Thomas/D-8791-2017 OI Antonsen, Thomas/0000-0002-2362-2430 NR 5 TC 18 Z9 18 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 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 1993 VL 21 IS 6 BP 760 EP 767 DI 10.1109/27.256797 PG 8 WC Physics, Fluids & Plasmas SC Physics GA MQ941 UT WOS:A1993MQ94100018 ER PT J AU MCMAHON, D AF MCMAHON, D TI MORE ON DCS IN AEROSPACE - REPLY SO INTECH LA English DT Letter RP MCMAHON, D (reprint author), NASA,LEWIS PROJECT,WICKLIFFE,OH, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INSTRUMENT SOC AMER PI RES TRIANGLE PK PA 67 ALEXANDER DRIVE, RES TRIANGLE PK, NC 27709 SN 0192-303X J9 INTECH JI Intech PD DEC PY 1993 VL 40 IS 12 BP 9 EP 9 PG 1 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA MP187 UT WOS:A1993MP18700003 ER PT J AU MIHEVIC, JA AF MIHEVIC, JA TI MORE ON DCS IN AEROSPACE SO INTECH LA English DT Letter RP MIHEVIC, JA (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INSTRUMENT SOC AMER PI RES TRIANGLE PK PA 67 ALEXANDER DRIVE, RES TRIANGLE PK, NC 27709 SN 0192-303X J9 INTECH JI Intech PD DEC PY 1993 VL 40 IS 12 BP 9 EP 9 PG 1 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA MP187 UT WOS:A1993MP18700002 ER PT J AU BOBIN, V WHITAKER, SR MAKI, GK AF BOBIN, V WHITAKER, SR MAKI, GK TI N-MODULAR REDUNDANCY USING THE THEORY OF ERROR-CORRECTING CODES SO INTERNATIONAL JOURNAL OF ELECTRONICS LA English DT Article AB Using redundancy is basic to fault-tolerant computing. N-modular redundancy (NMR) is in some ways analogous to the use of a repetition code where an information symbol is replicated as parity symbols in a codeword. Linear error-correcting codes (ECC) use linear combinations of information symbols as parity symbols to generate syndromes for error patterns. In this paper, ECC theory has been applied to derive redundant circuits that tolerate faults in both the modules and checkers. Circuits using comparators for diagnosis are derived with a non-graph-theoretic approach. Coding theoretic principles are applied directly to NMR, so that extensive diagnosis of the fault-tolerant system is achieved. C1 UNIV NEW MEXICO,NASA,SPACE ENGN RES CTR,VLSI SYST,ALBUQUERQUE,NM 87106. RP BOBIN, V (reprint author), HEWLETT PACKARD CORP,CALIF DESIGN CTR,1501 PAGE MILL RD,PALO ALTO,CA 94304, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0020-7217 J9 INT J ELECTRON JI Int. J. Electron. PD DEC PY 1993 VL 75 IS 6 BP 1071 EP 1081 DI 10.1080/00207219308907183 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA ML533 UT WOS:A1993ML53300004 ER PT J AU CHEN, JC STANTON, PH REILLY, HF AF CHEN, JC STANTON, PH REILLY, HF TI SKEW-GRID DICHROIC PLATE WITH RECTANGULAR APERTURES FOR USE ON A KA-BAND BEAM-WAVE-GUIDE ANTENNA SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article AB The first Ka-band Deep Space Network downlink demonstration was recently carried out by the Ka-Band Link Experiment (KABLE) in association with the Mars Observer spacecraft. In order to support the mission, a dichroic plate was required in the DSS-13 beam waveguide antenna to allow simultaneous X- and Ka-band dual-frequency operation. An X/Ka/KABLE dichroic plate was designed to transmit a future Ka-band downlink (31.8-32.3 GHz), future Ka-band uplink (34.2-34.7 GHz), and KABLE downlink frequency (33.6-33.8 GHz), while reflecting X-band (7.1-8.6 GHz). A computer program was developed for the analysis of a dichroic plate with rectangular apertures using the mode-matching method. The plate was then fabricated and tested. The reflection, group delay, and noise temperature in the antenna system due to the dichroic plate were measured. The experimental results show good agreement with theoretical predictions. RP CHEN, JC (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 9 TC 0 Z9 0 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 1993 VL 14 IS 12 BP 2401 EP 2422 DI 10.1007/BF02086215 PG 22 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA ML414 UT WOS:A1993ML41400002 ER PT J AU HUO, Y SCHREIBER, R AF HUO, Y SCHREIBER, R TI EFFICIENT, MASSIVELY-PARALLEL EIGENVALUE COMPUTATION SO INTERNATIONAL JOURNAL OF SUPERCOMPUTER APPLICATIONS AND HIGH PERFORMANCE COMPUTING LA English DT Article ID DISORDERED SYSTEMS; STATES AB In numerical simulations of disordered electronic systems, one of the most common approaches is to diagonalize random Hamiltonian matrices and to study the eigenvalues and eigenfunctions of a single electron in the presence of a random potential. We describe an effort to implement a matrix diagonalization routine for real symmetric dense matrices on massively parallel SIMD computers, the Maspar MP-1 and MP-2 systems. Results of numerical tests and timings are also presented. C1 NASA,AMES RES CTR,ADV COMP SCI RES INST,MOFFETT FIELD,CA 94035. RP HUO, Y (reprint author), PRINCETON UNIV,DEPT ELECT ENGN,PRINCETON,NJ 08544, USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 SN 1078-3482 J9 INT J SUPERCOMPUT AP JI Int. J. Supercomput. Appl. High Perform. Comput. PD WIN PY 1993 VL 7 IS 4 BP 292 EP 303 DI 10.1177/109434209300700402 PG 12 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications SC Computer Science GA MV971 UT WOS:A1993MV97100002 ER PT J AU MOGHADDAM, M CHEW, WC AF MOGHADDAM, M CHEW, WC TI SIMULTANEOUS INVERSION OF COMPRESSIBILITY AND DENSITY IN THE ACOUSTIC INVERSE PROBLEM SO INVERSE PROBLEMS LA English DT Article ID DIFFRACTION TOMOGRAPHY; TIME DOMAIN; PERMITTIVITY; ULTRASONICS AB The nonlinear acoustic inverse scattering problem with both variable compressibility and variable density is formulated and solved via the Born iterative method. This is equivalent to the simultaneous electromagnetic inversion of permittivity and permeability in the E(z)- or H(z)-polarized problem. The solution to the E(z)-polarized case for variable permittivity has been studied in detail previously. The results presented here for the H(z)-polarized caw and those for the simultaneous inversion (or acoustic) problem are new. Two volume integrals are used to represent the scattered field. The unknowns are found by performing Born-type iterations on the resulting integral equation. At each iteration, the unknowns are found through a double-criterion optimization. Several results are presented for both the H(z)-polarized and the simultaneous (acoustic) inverse problems. In this case, even though the resolution is subwavelength, it is found that compared to the E(z)-polarized case, the resolution is lower. C1 UNIV ILLINOIS,DEPT ELECT & COMP ENGN,ELECTROMAGNET LAB,URBANA,IL 61801. RP MOGHADDAM, M (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Chew, Weng Cho/C-1792-2009 NR 29 TC 10 Z9 10 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0266-5611 J9 INVERSE PROBL JI Inverse Probl. PD DEC PY 1993 VL 9 IS 6 BP 715 EP 730 DI 10.1088/0266-5611/9/6/008 PG 16 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA MP460 UT WOS:A1993MP46000008 ER PT J AU FIDDLER, W PENSABENE, JW GATES, RA JAHNCKE, ML HALE, MB AF FIDDLER, W PENSABENE, JW GATES, RA JAHNCKE, ML HALE, MB TI ATLANTIC MENHADEN (BREVOORTIA-TYRANNUS) MINCE AND SURIMI AS PARTIAL MEAT SUBSTITUTES IN FRANKFURTERS - EFFECT ON N-NITROSAMINE FORMATION SO JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY LA English DT Article ID FISH; DIMETHYLAMINE; VOLATILE AB Studies were conducted to determine the feasibility of using Atlantic menhaden mince and surimi as partial meat substitutes for red meats in the formulation of frankfurters. The effects of the following factors on methylamine and volatile nitrosamine content in broiled frankfurters substituted with the menhaden were evaluated: fish form (washed and unwashed mince and surimi), percent substitution (15 and 50%), storage of fresh and frozen fish preprocessing (0-6 months), and refrigerated storage of frankfurters postprocessing (0-56 days). The overall results of these studies indicate that only trace levels of N-nitrosodimethylamine, the only volatile nitrosamine detected, were found in these frankfurters. C1 NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,PASCAGOULA,MS 39568. NOAA,NATL MARINE FISHERIES SERV,CHARLESTON,SC 29412. RP FIDDLER, W (reprint author), USDA ARS,EASTERN REG RES CTR,600 E MERMAID LANE,PHILADELPHIA,PA 19118, USA. NR 29 TC 1 Z9 2 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-8561 J9 J AGR FOOD CHEM JI J. Agric. Food Chem. PD DEC PY 1993 VL 41 IS 12 BP 2238 EP 2241 DI 10.1021/jf00036a002 PG 4 WC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology SC Agriculture; Chemistry; Food Science & Technology GA MQ480 UT WOS:A1993MQ48000002 ER PT J AU GAO, BC GOETZ, AFH WESTWATER, ER CONEL, JE GREEN, RO AF GAO, BC GOETZ, AFH WESTWATER, ER CONEL, JE GREEN, RO TI POSSIBLE NEAR-IR CHANNELS FOR REMOTE-SENSING PRECIPITABLE WATER-VAPOR FROM GEOSTATIONARY SATELLITE PLATFORMS SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB Remote sensing of tropospheric water vapor profiles from current geostationary weather satellites is made using a few broadband infrared (IR) channels in the 6-13-mu m region. Uncertainties greater than 20% exist in derived water vapor values just above the surface from the IR emission measurements. In this paper, we propose three near-IR channels, one within the 0.94-mu m water vapor band absorption region, and the other two in nearby atmospheric windows, for remote sensing of precipitable water vapor over land areas, excluding lakes and rivers, during daytime from future geostationary satellite platforms. The physical principles are as follows. The reflectance of most surface targets varies approximately linearly with wavelength near 1 mu m. The solar radiation on the sun-surface-sensor ray path is attenuated by atmospheric water vapor. The ratio of the radiance from the absorption channel with the radiances from the two window channels removes the surface reflectance effects and yields approximately the mean atmospheric water vapor transmittance of the absorption channel. The integrated water vapor amount from ground to space can be obtained with a precision of better than 5% from the mean transmittance. Because surface reflectances vary slowly with time, temporal variation of precipitable water vapor can be determined reliably. High spatial resolution, precipitable water vapor images are derived from spectral data collected by the Airborne Visible-Infrared Imaging Spectrometer, which measures solar radiation reflected by the surface in the 0.4-2.5-mu m region in 10-nm channels and has a ground instantaneous field of view of 20 m from its platform on an ER-2 aircraft at 20 km. The proposed near-IR reflectance technique would complement the IR emission techniques for remote sensing of water vapor profiles from geostationary satellite platforms, especially in the boundary layer where most of the water vapor is located. C1 UNIV COLORADO,CTR STUDY EARTH SPACE,CIRES,BOULDER,CO. UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO. NOAA,ERL,WAVE PROPAGAT LAB,BOULDER,CO. JET PROPULS LAB,PASADENA,CA. NR 26 TC 20 Z9 24 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 1993 VL 32 IS 12 BP 1791 EP 1801 DI 10.1175/1520-0450(1993)032<1791:PNICFR>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ML882 UT WOS:A1993ML88200002 ER PT J AU HAKIMZADEH, R VARGASABURTO, C BAILEY, SG WILLIAMS, WS AF HAKIMZADEH, R VARGASABURTO, C BAILEY, SG WILLIAMS, WS TI EFFECT OF PROTON IRRADIATION AND ANNEALING ON THE DIFFUSION LENGTH IN INDIUM-PHOSPHIDE SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INP SOLAR-CELLS; RADIATION-RESISTANCE; INDUCED DEFECTS; DAMAGE AB We report on the measurement of the diffusion length damage coefficient (K(L)) and the annealing characteristics of the minority carrier diffusion length (L(n)) in Czochralski-grown zinc-doped indium phosphide (InP), with a carrier concentration of 1 X 10(18) cm-3. In measuring K(L), irradiations were made using 0.5 MeV protons with fluences ranging from 1 X 10(11) to 3 x 10(13) CM-2. Pre-and post-irradiation electron-beam induced current measurements allowed for the extraction of L(n), from which K(L) was determined. In studying the annealing characteristics of L(n), irradiations were made with 2 MeV protons with a fluence of 5 X 10(13) cm-2. Post-irradiation studies of L(n) with time at room temperature, and with minority carrier photoinjection and forward-bias injection were carried out. The results showed that recovery under Air Mass Zero photoinjection was complete. L(n) was also found to recover under forward-bias injection, where recovery was found to depend on the value of the injection current. However, no recovery of L(n) after proton irradiation was observed with time at room temperature, in contrast to the behavior of 1 MeV electron-irradiated InP solar cells reported previously. C1 KENT STATE UNIV,KENT,OH 44242. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. CASE WESTERN RESERVE UNIV,CLEVELAND,OH 44106. RP HAKIMZADEH, R (reprint author), SVERDRUP TECHNOL INC,BROOKPARK,OH 44142, USA. NR 27 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 1993 VL 74 IS 11 BP 6671 EP 6675 DI 10.1063/1.355110 PG 5 WC Physics, Applied SC Physics GA MJ712 UT WOS:A1993MJ71200031 ER PT J AU FATEMI, NS WEIZER, VG AF FATEMI, NS WEIZER, VG TI THE ACHIEVEMENT OF NEAR-THEORETICAL-MINIMUM CONTACT RESISTANCE TO INP SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID OHMIC CONTACT; SEMICONDUCTORS AB We have investigated the electrical and metallurgical behavior of the InP/Au/Ni contact system. We show that when a layer of Au, 100 angstrom or more in thickness, is introduced between n-InP and Ni contact metallization, specific contact resistivity R(c) values in the low 10(-8) OMEGA cm2 range are achieved after sintering. It is suggested that these ultralow values of R(c) are due to the presence, at the metal-InP interface, of a Ni3P layer combined with a stoichiometry change in the InP surface. We show, in addition, that it is possible to achieve very low R(c) values with this system without incurring device destroying sinter-induced metallurgical interdiffusion. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP FATEMI, NS (reprint author), SVERDRUP TECHNOL INC,LEWIS RES CTR GRP,21000 BROOKPARK RD,CLEVELAND,OH 44135, USA. NR 17 TC 8 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 1993 VL 74 IS 11 BP 6740 EP 6746 DI 10.1063/1.355071 PG 7 WC Physics, Applied SC Physics GA MJ712 UT WOS:A1993MJ71200041 ER PT J AU WOODMAN, CR TIPTON, CM EVANS, J LINDERMAN, JK GOSSELINK, K GRINDELAND, RE AF WOODMAN, CR TIPTON, CM EVANS, J LINDERMAN, JK GOSSELINK, K GRINDELAND, RE TI METABOLIC RESPONSES TO HEAD-DOWN SUSPENSION IN HYPOPHYSECTOMIZED RATS SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE MAXIMAL OXYGEN CONSUMPTION; CATECHOLAMINES; THYROID HORMONES; TESTOSTERONE; SPACE AND EXERCISE ID MAXIMAL OXYGEN-CONSUMPTION; HINDLIMB SUSPENSION; SIMULATED WEIGHTLESSNESS; CHEMICAL SYMPATHECTOMY; MUSCLE; CAPACITY; BEDREST AB Rats exposed to head-down suspension (HDS) exhibit reductions in maximal O-2 consumption (Vo(2max)) and atrophy of select hindlimb muscles. This study tested the hypothesis that an endocrine-deficient rat exposed to HDS would not exhibit reductions in Vo(2max) or hindlimb muscle mass. Hypophysectomized (HYPX) and sham-operated (SHAM) rats were tested for Vo(2max) before and after 28 days of HDS or cage control (CC) conditions. No significant reductions in Vo(2max) were observed in HYPX rats. In contrast, SHAM-HDS rats exhibited a significant reduction in absolute (-16%) and relative (-29%) measures of aerobic capacity. Time course experiments revealed a reduction in Vo(2max) in SHAM-HDS rats within 7 days, suggesting that cardiovascular adjustments to HDS occurred in the 1st wk. HDS was associated with atrophy of the soleus (-42%) in SHAM rats, whereas HYPX rats exhibited atrophy of the soleus (-36%) and plantaris (-13%). SHAM-HDS rats had significantly lower (-38%) soleus citrate synthase activities per gram muscle mass than SHAM-CC, but no significant differences existed between HYPX-HDS and -CC rats. HDS rats had an impaired ability to thermoregulate, as indicated by significantly greater temperature increases per unit run time, compared with their CC counterparts. Pretreatment plasma epinephrine levels were significantly lower in HYPX than in SHAM rats. Norepinephrine concentration was similar for all groups except HYPX-HDS, in which it was significantly higher. HDS had no significant effect on thyroxine or triiodothyronine. SHAM-HDS rats had significantly lower concentrations of testosterone and growth hormone. We concluded that HYPX rats could maintain aerobic capacity but not hindlimb muscle mass when exposed to HDS. C1 NASA,AMES RES CTR,DIV LIFE SCI,MOFFETT FIELD,CA 94035. RP WOODMAN, CR (reprint author), UNIV ARIZONA,DEPT EXERCISE & SPORT SCI,INA E GITTINGS BLDG,TUCSON,AZ 85721, USA. FU NHLBI NIH HHS [HL-07249] NR 32 TC 15 Z9 16 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD DEC PY 1993 VL 75 IS 6 BP 2718 EP 2726 PG 9 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA MN705 UT WOS:A1993MN70500051 PM 8125895 ER PT J AU CAVALLO, R ARNAUD, KA TRIMBLE, V AF CAVALLO, R ARNAUD, KA TRIMBLE, V TI AN UPPER LIMIT TO CORONAL X-RAYS FROM SINGLE, MAGNETIC WHITE-DWARFS SO JOURNAL OF ASTROPHYSICS AND ASTRONOMY LA English DT Article DE WHITE DWARFS; STELLAR CORONAE; X-RAY EMISSION AB Pointed ROSAT PSPC exposures of 9277 and 6992 sec, directed toward the nearby, single, cool, magnetic white dwarfs GR 290 and EG 250 yielded no counts significantly above the expected background rate. The corresponding flux limits (for an assumed source temperature of 1 keV) are 1.0 and 1.7 x 10(-14) erg cm-2s-1, within the 0.1-2.5 keV bandpass of the instrument (99% confidence limits). This is more than an order of magnitude below the tentative detection level (for GR 290) and limits (for four other similar stars) obtained from archival Einstein data in 1991. The corresponding limits on coronal electron density are comparable with those implied if cyclotron emission is not responsible for any of the features observed in the optical spectra of magnetic white dwarfs. X-ray data currently provide no evidence for the existence of coronae around these stars. A final long observation (25,000 sec of GD 356) is scheduled for later this year on ROSAT, along with coordinated EUVE observations. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV CALIF IRVINE,DEPT PHYS,IRVINE,CA 92717. RP CAVALLO, R (reprint author), UNIV MARYLAND,DEPT ASTRON,COLL PK,MD 20742, USA. NR 6 TC 7 Z9 7 U1 0 U2 0 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0250-6335 J9 J ASTROPHYS ASTRON JI J. Astrophys. Astron. PD DEC PY 1993 VL 14 IS 3-4 BP 141 EP 143 DI 10.1007/BF02702364 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MV891 UT WOS:A1993MV89100005 ER PT J AU STAYLOR, WF AF STAYLOR, WF TI STABILITY OF THE EARTH RADIATION BUDGET EXPERIMENT SCANNER RESULTS FOR THE 1ST 2 YEARS OF MULTIPLE-SATELLITE OPERATION SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Clear-sky albedos and outgoing longwave radiation (OLR) determined from Earth Radiation Budget Experiment (ERBE) scanners on board the earth radiation budget satellite and NOAA-9 spacecraft were analyzed for three target sites for the months February 1985-January 1987. The targets were oceans, deserts, and a multiscene site covering half the earth's surface. Year-to-year ratios of the monthly albedos and OLR were within the 0.98-1.02 range with a standard error of about 1%. The data indicate that ERBE scanner measurements were stable to within a few tenths of a percent for the two-year period. RP STAYLOR, WF (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,MAIL STOP 420,HAMPTON,VA 23665, USA. NR 0 TC 2 Z9 2 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 1993 VL 10 IS 6 BP 827 EP 832 PG 6 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA MJ290 UT WOS:A1993MJ29000004 ER PT J AU LUEKEN, SA ARNAUD, SB TAYLOR, AK BAYLINK, DJ AF LUEKEN, SA ARNAUD, SB TAYLOR, AK BAYLINK, DJ TI CHANGES IN MARKERS OF BONE-FORMATION AND RESORPTION IN A BED REST MODEL OF WEIGHTLESSNESS SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Article ID GLA-PROTEIN; DISUSE OSTEOPOROSIS; SERUM; PHOSPHATASE; OSTEOCALCIN; TURNOVER; COLLAGEN; ACID AB To study the mechanism of bone loss in physical unloading, we examined indices of bone formation and bone resorption in the serum and urine of eight healthy men during a 7 day -6-degrees head-down tilt bed rest. Prompt increases in markers of resorption-pyridinoline (PD), deoxypyridinoline (DPD), and hydroxyproline (Hyp)/g creatinine-during the first few days of inactivity were paralleled by tartrate-resistant acid phosphatase (TRAP) with significant increases in all these markers by day 4 of bed rest. An index of formation, skeletal alkaline phosphatase (SALP), did not change during bed rest and showed a moderate 15% increase 1 week after reambulation. In contrast to SALP, serum osteocalcin (OC) began increasing the day preceding the increase in Hyp, remained elevated for the duration of the bed rest, and returned to pre-bed rest values within 5 days of reambulation. Similarly, DPD increased significantly at the onset of bed rest, remained elevated for the duration of bed rest, and returned to pre-bed rest levels upon reambulation. On the other hand, the other three indices of resorption, Hyp, PD, and TRAP, remained elevated for 2 weeks after reambulation. The most sensitive indices,of the levels of physical activity proved to be the noncollagenous protein, OC, and the collagen crosslinker, DPD. The bed rest values of both these markers were significantly elevated compared to both the pre-bed rest values and the post-bed rest values. The sequence of changes in the circulating markers of bone metabolism indicated that increases in serum OC are the earliest responses of bone to head-down tilt bed rest. C1 JERRY L PETTIS VET ADM MED CTR,DEPT RES,11201 BENTON ST,LOMA LINDA,CA 92357. NASA,AMES RES CTR,DIV LIFE SCI,MOFFETT FIELD,CA 94035. LOMA LINDA UNIV,DEPT MED,LOMA LINDA,CA 92350. LOMA LINDA UNIV,DEPT BIOCHEM,LOMA LINDA,CA 92350. NR 29 TC 87 Z9 90 U1 0 U2 2 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD DEC PY 1993 VL 8 IS 12 BP 1433 EP 1438 PG 6 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA MH552 UT WOS:A1993MH55200003 PM 8304043 ER PT J AU MARTIN, JML TAYLOR, PR LEE, TJ AF MARTIN, JML TAYLOR, PR LEE, TJ TI ACCURATE AB-INITIO QUARTIC FORCE-FIELDS FOR THE IONS HCO+ AND HOC+ (VOL 99, PG 286, 1993) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Correction, Addition ID INFRARED-LASER SPECTROSCOPY; MOLECULAR-IONS; FUNDAMENTAL-BAND; NU-1 BAND; DCO+ C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP MARTIN, JML (reprint author), SAN DIEGO SUPERCOMP CTR,POB 85608,SAN DIEGO,CA 92186, USA. RI Lee, Timothy/K-2838-2012; Martin, Jan/A-7457-2008 OI Martin, Jan/0000-0002-0005-5074 NR 12 TC 5 Z9 5 U1 1 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 DEC 1 PY 1993 VL 99 IS 11 BP 9326 EP 9326 DI 10.1063/1.466241 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA MJ902 UT WOS:A1993MJ90200103 ER PT J AU ROSSOW, WB GARDER, LC AF ROSSOW, WB GARDER, LC TI CLOUD DETECTION USING SATELLITE MEASUREMENTS OF INFRARED AND VISIBLE RADIANCES FOR ISCCP SO JOURNAL OF CLIMATE LA English DT Article ID CLIMATE-RESEARCH; AVHRR DATA; SPATIAL-RESOLUTION; LANDSAT IMAGERY; COVER ANALYSIS; CLEAR-SKY; DATA SET; SURFACE; PARAMETERS; FIELDS AB The International Satellite Cloud Climatology Project (ISCCP) began in 1983 to collect and analyze weather satellite radiance datasets to produce a new global cloud climatology as part of the World Climate Research Programme. This paper, the first of three, describes the cloud detection part of the ISCCP analysis. Key features of the cloud detection algorithm are 1) use of space and time radiance variation tests over several different space and time domains to account for the global variety of cloudy and clear characteristics, 2) estimation of clear radiance values for every time and place, and 3) use of radiance thresholds that vary with type of surface and climate regime. Design of the detection algorithm was supported by global, multiyear surveys of the statistical behavior of satellite-measured infrared and visible radiances to determine those characteristics that differentiate cloudy and clear scenes and how these characteristics vary among climate regimes. A summary of these statistical results is presented to illustrate how the cloud detection method works in a variety of circumstances. The sensitivity of the results to changing test parameter values is determined to provide a first estimate of the uncertainty of ISCCP cloud amounts. These test results (which exclude polar regions) suggest detection uncertainties of about 10% with possible negative biases of 5% (especially at night). C1 COLUMBIA UNIV,NEW YORK,NY. RP ROSSOW, WB (reprint author), NASA,GODDARD INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA. RI Rossow, William/F-3138-2015 NR 52 TC 264 Z9 281 U1 5 U2 17 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 1993 VL 6 IS 12 BP 2341 EP 2369 DI 10.1175/1520-0442(1993)006<2341:CDUSMO>2.0.CO;2 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MQ614 UT WOS:A1993MQ61400010 ER PT J AU ROSSOW, WB GARDER, LC AF ROSSOW, WB GARDER, LC TI VALIDATION OF ISCCP CLOUD DETECTIONS SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; AVHRR DATA; CLIMATE-RESEARCH; SATELLITE DATA; COVER ANALYSIS; WATER-VAPOR; CLEAR-SKY; ABSORPTION; RESOLUTION; RADIATION AB The International Satellite Cloud Climatology Project(ISCCP) began in 1983 to collect and analyze weather satellite datasets to produce a new global cloud climatology as part of the World Climate Research Programme. The first step of the analysis is detection of the presence of clouds at each location and time by a series of tests on the space/time variations of infrared and visible radiances. This paper describes the validation of the ISCCP cloud detections by verifying the accuracy of the inferred clear-sky radiances. Comparison of retrieved surface temperatures to other measurements shows that bias errors are <2 K and random errors are about 2 K for sea surface (monthly means at 280-km scales) and that bias errors are <2 K and random errors are about 4 K for land surfaces (3 hourly at 280-km scale). Bias errors over a few persistently cloudy locations are sometimes -(2-4) K and over winter sea ice may be about +2 K. Surface reflectances are confirmed to be within 3% of other measurements and models for ocean, except for sun glint geometries, and to be within 3%-5% for land surfaces. Sufficiently accurate validation data are not available for visible reflectances of sea ice and snow-covered land, but some tests of specific cases suggest that errors are similar to 10%. These errors in clear-sky radiances suggest uncertainties in the ISCCP cloud detections of about 10% with a small ( 3%-6%) negative bias over land. Some specific regions exhibit both larger rms uncertainties and somewhat larger biases in cloud amount approaching 10%. ISCCP cloud detections are more in error over the polar regions than anywhere else. Based on comparisons with an analysis of radiances measured at other wavelengths, the ISCCP analysis appears to miss 15%-25% of the clouds in summer but only 5%-10% of the winter clouds. C1 COLUMBIA UNIV,NEW YORK,NY. RP ROSSOW, WB (reprint author), NASA,GODDARD INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA. RI Rossow, William/F-3138-2015 NR 71 TC 157 Z9 172 U1 1 U2 8 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 1993 VL 6 IS 12 BP 2370 EP 2393 DI 10.1175/1520-0442(1993)006<2370:VOICD>2.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MQ614 UT WOS:A1993MQ61400011 ER PT J AU ROSSOW, WB WALKER, AW GARDER, LC AF ROSSOW, WB WALKER, AW GARDER, LC TI COMPARISON OF ISCCP AND OTHER CLOUD AMOUNTS SO JOURNAL OF CLIMATE LA English DT Article ID RESOLUTION LANDSAT IMAGERY; SPATIAL-RESOLUTION; NORTHERN-HEMISPHERE; CLIMATE-RESEARCH; CUMULUS CLOUDS; SATELLITE DATA; AVHRR DATA; SURFACE; COVER; FIELDS AB A new 8-year global cloud climatology has been produced by the International Satellite Cloud Climatology Project (ISCCP) that provides information every 3 h at 280-km spatial resolution covering the period from July 1983 through June 1991. If cloud detection errors and differences in area sampling are neglected, individual ISCCP cloud amounts agree with individual surface observations to within 15% rms with biases of only a few percent. When measurements of small-scale, broken clouds are isolated in the comparison, the rms differences between satellite and surface cloud amounts are about 25%, similar to the rms difference between ISCCP and Landsat determinations of cloud amount. For broken clouds, the average ISCCP cloud amounts are about 5% smaller than estimated by surface observers (difference between earth cover and sky cover), but about 5% larger than estimated from very high spatial resolution satellite observations (overestimate due to low spatial resolution offset by underestimate due to finite radiance thresholds). Detection errors, caused by errors in the ISCCP clear-sky radiances or incorrect radiance threshold magnitudes, are the dominant source of error in monthly average cloud amounts. The ISCCP cloud amounts appear to be too low over land by about 10%, somewhat less in summer and somewhat more in winter, and about right (maybe slightly low) over oceans. In polar regions, ISCCP cloud amounts are probably too low by about 15%-25% in summer and 5%-10% in winter. Comparison of the ISCCP climatology to three other cloud climatologies shows excellent agreement in the geographic distribution and seasonal variation of cloud amounts; there is little agreement about day/night contrasts in cloud amount. Notable results from ISCCP are that the global annual mean cloud amount is about 63%, being about 23% higher over oceans than over land, that it varies by <1% rms from month to month, and that it has varied by about 4% on a time scale approximate to 2-4 years. The magnitude of interannual variations of local (280-km scale) monthly mean cloud amounts is about 7%-9%. Longitudinal contrasts in cloud amount are just as large as latitudinal contrasts. The largest seasonal variation of cloud amount occurs in the tropics, being larger in summer than in winter; the seasonal variation in middle latitudes has the opposite phase. Polar regions may have little seasonal variability in cloud amount. The ISCCP results show slightly more nighttime than daytime cloud amount over oceans and more daytime than nighttime cloud amount over land. C1 HUGHES STX,NEW YORK,NY. COLUMBIA UNIV,NEW YORK,NY. RP ROSSOW, WB (reprint author), NASA,GODDARD INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA. RI Rossow, William/F-3138-2015 NR 51 TC 206 Z9 238 U1 0 U2 8 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 1993 VL 6 IS 12 BP 2394 EP 2418 DI 10.1175/1520-0442(1993)006<2394:COIAOC>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MQ614 UT WOS:A1993MQ61400012 ER PT J AU OBRIEN, TK MARTIN, RH AF OBRIEN, TK MARTIN, RH TI ROUND-ROBIN TESTING FOR MODE-I INTERLAMINAR FRACTURE-TOUGHNESS OF COMPOSITE-MATERIALS SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article DE COMPOSITE MATERIALS; DOUBLE CANTILEVER BEAM (DCB); INTERLAMINAR FRACTURE TOUGHNESS; DELAMINATION; STANDARD TEST METHOD AB This report summarizes the results of several interlaboratory ''round robin'' test programs for measuring the Mode I interlaminar fracture toughness of advanced fiber-reinforced composite materials. Double cantilever beam (DCB) tests were conducted by participants in ASTM Committee D-30 on High Modulus Fibers and Their Composites and by representatives of the European Group on Fracture (EGF) and the Japanese Industrial Standards Group (JIS). DCB tests were performed on three AS4 carbon fiber-reinforced composite materials: AS4/3501-6 with a brittle epoxy matrix. AS4/BP907 with a tough epoxy matrix, and AS4/PEEK with a tough thermoplastic matrix. Difficulties encountered in manufacturing panels, as well as conducting the tests, are discussed. Critical issues that developed during the course of the testing are highlighted. Results of the round robin testing used to determine the precision of the ASTM DCB test standard are summarized. C1 ANALYT SERV & MAT INC,HAMPTON,VA 23666. RP OBRIEN, TK (reprint author), NASA,USA RES LAB,LANGLEY RES CTR,VEHICLE STRUCT DIRECTORATE,HAMPTON,VA 23681, USA. NR 14 TC 56 Z9 56 U1 1 U2 4 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD WIN PY 1993 VL 15 IS 4 BP 269 EP 281 PG 13 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA MN396 UT WOS:A1993MN39600001 ER PT J AU JACKSON, WC POE, CC AF JACKSON, WC POE, CC TI THE USE OF IMPACT FORCE AS A SCALE PARAMETER FOR THE IMPACT RESPONSE OF COMPOSITE LAMINATES SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article DE COMPOSITE MATERIAL; CARBON EPOXY; IMPACT; DELAMINATION; TRANSVERSE SHEAR FORCE AB The building block approach is currently used to design composite structures. With this approach, the data from coupon tests are scaled up to determine the design of a structure. Current standard impact tests and methods of relating test data to other structures are not generally understood and are often used improperly. A methodology is outlined for using impact force as a scale parameter for delamination damage for impacts of simple plates. Dynamic analyses were used to define ranges of plate parameters and impact parameters where quasi-static analyses are valid. These ranges include most low-velocity impacts where the mass of the impacter is large and the size of the specimen is small. For large-mass impacts of moderately thick (0.35 to 0.70 cm) laminates, the maximum extent of delamination damage increased with increasing impact force and decreasing specimen thickness. For large-mass impact tests at a given kinetic energy, impact force and hence delamination size depends on specimen size, specimen thickness, layup, boundary conditions, and indenter size and shape. If damage is reported in terms of impact force instead of kinetic energy, large-mass test results can be applied directly to other plates of the same thickness and layup. RP JACKSON, WC (reprint author), NASA,USA RES LAB,LANGLEY RES CTR,VEHICLE STRUCT DIRECTORATE,HAMPTON,VA 23681, USA. NR 17 TC 57 Z9 60 U1 0 U2 1 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD WIN PY 1993 VL 15 IS 4 BP 282 EP 289 PG 8 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA MN396 UT WOS:A1993MN39600002 ER PT J AU JOHNSON, WS MIRDAMADI, M BAHEIELDIN, YA AF JOHNSON, WS MIRDAMADI, M BAHEIELDIN, YA TI STRESS-STRAIN ANALYSIS OF A [0/90](2S) TITANIUM MATRIX LAMINATE SUBJECTED TO A GENERIC HYPERSONIC FLIGHT PROFILE SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article DE SILICON-CARBIDE FIBERS; INTERFACE; RESIDUAL STRESSES; THERMAL STRAINS; VISCOPLASTICITY THEORY AB Cross-ply laminate behavior of Ti-15V-3Cr-3Al-3Sn (Ti-15-3) matrix reinforced with continuous silicon-carbide fibers (SCS-6) subjected to a generic hypersonic flight profile was evaluated experimentally and analytically. Thermomechanical fatigue (TMF) test techniques were developed to conduct a simulation of a generic hypersonic flight profile. A micromechanical analysis was used. The analysis predicts the stress-strain response of the laminate and of the constituents in each ply during thermal and mechanical cycling by using only constituent properties as input. The fiber was modeled as elastic with transverse orthotropic and temperature-dependent properties. The matrix was modeled using a thermo-viscoplastic constitutive relation. The fiber transverse modulus was reduced in the analysis to simulate the fiber-matrix interface failure. Excellent correlation was found between measured and predicted laminate stress-strain response due to generic hypersonic flight profile when fiber debonding was modeled. C1 CAIRO UNIV,DEPT STRUCT ENGN,GIZA,EGYPT. RP JOHNSON, WS (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 16 TC 10 Z9 10 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD WIN PY 1993 VL 15 IS 4 BP 297 EP 303 PG 7 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA MN396 UT WOS:A1993MN39600004 ER PT J AU BIGELOW, CA AF BIGELOW, CA TI THERMAL RESIDUAL-STRESSES IN A SILICON-CARBIDE TITANIUM [0/90] LAMINATE SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article DE CROSS-PLY; UNIDIRECTIONAL; FINITE ELEMENT ANALYSIS; MICROMECHANICS; STRESS CONTOURS ID FIBER AB The current work formulated a micromechanical analysis of a cross-ply laminate and calculated the thermal residual stress in a very thick [0/90]ns silicon-carbide/titanium laminate. Results were also shown for a unidirectional laminate of the same material. Discrete fiber-matrix models assuming a rectangular array of fibers with a fiber volume fraction of 32.5% and a three-dimensional, finite element analysis were used. Significant differences in the trends and magnitudes for the fiber, matrix, and interface stresses were calculated for the unidirectional and [0/90] models. Larger hoop stresses calculated for the [0/90] model indicate that it may be more susceptible to radial cracking when subjected to mechanical loading than the unidirectional model. The axial stresses in the matrix were calculated to be slightly larger for the [0/90] model. The compressive axial stresses in the fiber were significantly larger in the [0/90] model. The presence of the cross-ply in the [0/90] model reduced the constraint on the fiber, producing radial interface stresses that were less compressive, which could lead to earlier failure of the fiber-matrix interface. RP BIGELOW, CA (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 8 TC 28 Z9 28 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD WIN PY 1993 VL 15 IS 4 BP 304 EP 310 PG 7 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA MN396 UT WOS:A1993MN39600005 ER PT J AU RAI, MM MOIN, P AF RAI, MM MOIN, P TI DIRECT NUMERICAL-SIMULATION OF TRANSITION AND TURBULENCE IN A SPATIALLY EVOLVING BOUNDARY-LAYER SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article C1 STANFORD UNIV,STANFORD,CA 94305. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP RAI, MM (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 20 TC 107 Z9 112 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 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD DEC PY 1993 VL 109 IS 2 BP 169 EP 192 DI 10.1006/jcph.1993.1210 PG 24 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ML314 UT WOS:A1993ML31400003 ER PT J AU BIESIADECKI, JJ SKEEL, RD AF BIESIADECKI, JJ SKEEL, RD TI DANGERS OF MULTIPLE TIME-STEP METHODS SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID HAMILTONIAN-SYSTEMS; CANONICAL METHODS C1 UNIV ILLINOIS,DEPT COMP SCI,URBANA,IL 61801. UNIV ILLINOIS,BECKMAN INST,URBANA,IL 61801. RP BIESIADECKI, JJ (reprint author), JET PROPULS LAB,4800 OAK GROVE DR,MS 301-345,PASADENA,CA 91109, USA. NR 12 TC 85 Z9 85 U1 2 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD DEC PY 1993 VL 109 IS 2 BP 318 EP 328 DI 10.1006/jcph.1993.1220 PG 11 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ML314 UT WOS:A1993ML31400013 ER PT J AU FERRARO, RD LIEWER, PC DECYK, VK AF FERRARO, RD LIEWER, PC DECYK, VK TI DYNAMIC LOAD BALANCING FOR A 2D CONCURRENT PLASMA PIC CODE SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article C1 UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. RP FERRARO, RD (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 11 TC 24 Z9 24 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 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD DEC PY 1993 VL 109 IS 2 BP 329 EP 340 DI 10.1006/jcph.1993.1221 PG 12 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ML314 UT WOS:A1993ML31400014 ER PT J AU BELL, JH MEHTA, RD AF BELL, JH MEHTA, RD TI EFFECTS OF IMPOSED SPANWISE PERTURBATIONS ON PLANE MIXING-LAYER STRUCTURE SO JOURNAL OF FLUID MECHANICS LA English DT Article ID STREAMWISE VORTICAL STRUCTURES; FREE SHEAR-LAYER; TURBULENT; EVOLUTION; INSTABILITY; GROWTH AB The origin and evolution of spatially stationary streamwise vortical structures in plane mixing layers with laminar initial boundary layers were recently examined quantitatively (Bell & Mehta 1992). When both initial boundary layers were made turbulent, such spatially-stationary streamwise structures were not measured which is indicative of the high sensitivity of these structures to initial conditions. In the present study, the effects of four different types of spanwise perturbations at the origin of the mixing layer were investigated. The wavelengths of the imposed perturbations were chosen to be comparable to the initial Kelvin-Helmholtz wavelength. For the first two perturbations, the boundary layers were otherwise left undisturbed. A serration on the splitter plate trailing edge was found to have a relatively small effect on the formation and development of the streamwise structures. The introduction of cylindrical pegs in the high-speed side boundary layer not only generated a regular array of vortex pairs, but also affected the mixing-layer growth rate and turbulence properties in the far-field region. For the other two perturbations, the initial boundary layers were tripped on the splitter plate. An array of vortex generators mounted in the high-speed boundary layer and a corrugated surface attached to the splitter plate trailing edge had essentially the same effects. Both imposed a regular array of relatively strong streamwise vortices in counter-rotating pairs upon the mixing layer. This resulted in large spanwise distortions of the mixing layer mean properties and Reynolds stresses. While the vorticity injection increased the growth rate in the near-field region as expected, the far-field growth rate was reduced by a factor of about two, together with the peak Reynolds stress levels. This result is attributed to the effect of the relatively strong streamwise vorticity in making the spanwise structures more three-dimensional and hence reducing entrainment during the pairing process. The imposed streamwise vorticity did not follow the pattern of increasing spanwise spacing seen in the 'naturally occurring' streamwise vorticity. The mean streamwise vorticity decayed with increasing streamwise distance in all cases, albeit at different rates. C1 NASA, AMES RES CTR, FLUID MECH LAB, MOFFETT FIELD, CA 94035 USA. STANFORD UNIV, DEPT AERONAUT & ASTRONAUT, STANFORD, CA 94305 USA. RP BELL, JH (reprint author), STANFORD UNIV, NASA, AMES RES CTR, CTR TURBULENCE RES, STANFORD, CA 94305 USA. NR 38 TC 26 Z9 26 U1 1 U2 5 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-1120 EI 1469-7645 J9 J FLUID MECH JI J. Fluid Mech. PD DEC PY 1993 VL 257 BP 33 EP 63 DI 10.1017/S0022112093002988 PG 31 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA MP492 UT WOS:A1993MP49200002 ER PT J AU CAMBON, C COLEMAN, GN MANSOUR, NN AF CAMBON, C COLEMAN, GN MANSOUR, NN TI RAPID DISTORTION ANALYSIS AND DIRECT SIMULATION OF COMPRESSIBLE HOMOGENEOUS TURBULENCE AT FINITE MACH NUMBER SO JOURNAL OF FLUID MECHANICS LA English DT Article ID ISOTROPIC TURBULENCE; ROTATION AB The effect of rapid mean compression on compressible turbulence at a range of turbulent Mach numbers is investigated. Rapid distortion theory (RDT) and direct numerical simulation results for the case of axial (one-dimensional) compression are used to illustrate the existence of two distinct rapid compression regimes. These regimes - the nearly solenoidal and the 'pressure-released' - are defined by a single parameter involving the timescales of the mean distortion, the turbulence, and the speed of sound. A general RDT formulation is developed and is proposed as a means of improving turbulence models for compressible flows. In contrast to the well-documented observation that 'compressibility' (measured, for example, by the turbulent Mach number) is often associated with a decrease in the growth rate of turbulent kinetic energy, we find that under rapid distortion compressibility can produce an amplification of the kinetic energy growth rate. We also find that as the compressibility increases, the magnitude of the pressure-dilation correlation increases, in absolute terms, but its relative importance decreases compared to the magnitude of the kinetic energy production. C1 STANFORD UNIV,CTR TURBULENCE RES,STANFORD,CA 94305. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP CAMBON, C (reprint author), ECOLE CENT LYON,MECAN FLUIDES & ACOUST LAB,CNRS,URA 263,F-69130 ECULLY,FRANCE. NR 30 TC 35 Z9 35 U1 2 U2 6 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 PY 1993 VL 257 BP 641 EP 665 DI 10.1017/S0022112093003258 PG 25 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA MP492 UT WOS:A1993MP49200029 ER PT J AU KAO, HC AF KAO, HC TI TURBULENT-FLOW IN 2-INLET CHANNELS SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID WALL AB The problem of turbulent flows in two-inlet channels has been studied numerically by solving the Reynolds-averaged Navier-Stokes equations with the k - epsilon model in a mapped domain. Both the high Reynolds number and the low Reynolds number form were used for this purpose. In general, the former predicts a weaker and smaller recirculation zone than the latter. Comparisons with experimental data, when applicable, were also made. The bulk of the present computations used, however, the high Reynolds number form to correlate different geometries and inflow conditions with the flow properties after turning. RP NASA, LEWIS RES CTR, CLEVELAND, OH 44135 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU ASME PI NEW YORK PA TWO PARK AVE, NEW YORK, NY 10016-5990 USA SN 0098-2202 EI 1528-901X J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD DEC PY 1993 VL 115 IS 4 BP 638 EP 645 DI 10.1115/1.2910192 PG 8 WC Engineering, Mechanical SC Engineering GA MR520 UT WOS:A1993MR52000018 ER PT J AU GLASSMEIER, KH MOTSCHMANN, U MAZELLE, C NEUBAUER, FM SAUER, K FUSELIER, SA ACUNA, MH AF GLASSMEIER, KH MOTSCHMANN, U MAZELLE, C NEUBAUER, FM SAUER, K FUSELIER, SA ACUNA, MH TI MIRROR MODES AND FAST MAGNETOACOUSTIC WAVES NEAR THE MAGNETIC PILEUP BOUNDARY OF COMET-P HALLEY SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID QUASI-PERPENDICULAR SHOCK; GIACOBINI-ZINNER; SOLAR-WIND; UP REGION; BOW SHOCK; GIOTTO; MAGNETOSHEATH; MAGNETOSPHERE; INSTABILITY; DOWNSTREAM AB Large-amplitude ultralow-frequency wave structures observed on both sides of the magnetic pileup boundary of comet P/Halley during the flyby of the Giotto spacecraft have been analyzed using suprathermal electron density and magnetic field observations. Upstream of the boundary, electron density and magnetic field magnitude variations are anticorrelated, while in the pileup region these quantities are clearly correlated. Both in front of and behind the pileup boundary the observed waves are quasi-perpendicular wave structures as a minimum variance analysis shows. A detailed comparison of our observations in the prepileup region with theoretical and numerical results shows that the mirror mode mode waves may have been generated by a mirror instability driven by the pressure anisotropy of the ring-type distributions of the heavy (water group) pickup cometary ions. A mean wavelength lambda1 = 2071 km is found, which is about 4 times the water group ion thermal gyroradius. For the fast mode wave structures in the pileup region, analysis of wave propagation on both sides of the pileup boundary shows that mode conversion from the mirror mode to fast mode type waves at the boundary is not a possible source mechanism. However, we show that the fast mode waves may be interpreted as stationary wave structures in a multifluid plasma. The wavelength lambda2 = 1141 km derived from the observations, when using the stationary wave hypothesis, is in good agreement with the theoretical expected wave length lambda(theo) = (774 +/- 506) km computed from available ion observations. C1 UNIV COLOGNE,INST GEOPHYS & METEOROL,D-54175 COLOGNE,GERMANY. MAX PLANCK INST EXTRATERR PHYS,BERLIN,GERMANY. LOCKHEED PALO ALTO RES LABS,PALO ALTO,CA 94304. NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. RP GLASSMEIER, KH (reprint author), TECH UNIV CAROLO WILHELMINA BRAUNSCHWEIG,INST GEOPHYS & METEOROL,MENDELSSOHNSTR 3,D-38106 BRAUNSCHWEIG,GERMANY. NR 34 TC 43 Z9 43 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 1993 VL 98 IS A12 BP 20955 EP 20964 DI 10.1029/93JA02582 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600006 ER PT J AU HUDDLESTON, DE COATES, AJ JOHNSTONE, AD NEUBAUER, FM AF HUDDLESTON, DE COATES, AJ JOHNSTONE, AD NEUBAUER, FM TI MASS LOADING AND VELOCITY DIFFUSION-MODELS FOR HEAVY PICKUP IONS AT COMET GRIGG-SKJELLERUP SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HALLEY BOW SHOCK; SOLAR-WIND; SPACE DIFFUSION; WATER GROUP; DISTRIBUTIONS; ACCELERATION; P/HALLEY; UPSTREAM; PLASMA; REGION AB We compare model predictions of cometary water group ion densities and the solar wind slow down with measurements made by the Giotto Johnstone plasma analyzer implanted ion sensor at the encounter with comet Grigg-Skjellerup (G-S) on July 10, 1992. The observed slope of the ion density profile on approach to the comet is unexpectedly steep. Possible explanations for this are discussed. We present also a preliminary investigation of the quasilinear velocity-space diffusion of the implanted heavy ion population at G-S using a transport equation including source, convection, adiabatic compression, and velocity diffusion terms. Resulting distributions are anisotropic, in agreement with observations. We consider theoretically the waves that may be generated by the diffusion process for the observed solar wind conditions. At initial ion injection, waves are generated at omega - OMEGA(i) the ion gyrofrequency, and lower frequencies are predicted for diffusion toward a bispherical shell. C1 UCL, MULLARD SPACE SCI LAB, DORKING RH5 6NT, SURREY, ENGLAND. UNIV COLOGNE, INST GEOPHYS & METEOROL, W-5000 COLOGNE 41, GERMANY. RP JET PROP LAB, 4800 OAK GREVE DR, MS 169-506, PASADENA, CA 91109 USA. RI Coates, Andrew/C-2396-2008 OI Coates, Andrew/0000-0002-6185-3125 NR 32 TC 20 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1993 VL 98 IS A12 BP 20995 EP 21002 DI 10.1029/93JA02531 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600010 ER PT J AU SRIVASTAVA, KM TSURUTANI, BT GOLDSTEIN, BE SHARMA, V OKADA, M AF SRIVASTAVA, KM TSURUTANI, BT GOLDSTEIN, BE SHARMA, V OKADA, M TI ACCELERATION OF COMETARY H2O GROUP PICKUP IONS BY OBLIQUELY PROPAGATING NONLINEAR MAGNETOSONIC WAVES SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID FREQUENCY ELECTROMAGNETIC-WAVES; STRONG HYDROMAGNETIC TURBULENCE; PITCH-ANGLE SCATTERING; GIACOBINI-ZINNER; SOLAR-WIND; MAGNETIC-FIELD; BOW-SHOCK; WATER GROUP; HALLEY; INSTABILITIES AB The observations made during the encounter with comet Giacobini Zinner show that the character of MHD turbulence is governed by the magnetosonic (MS) waves generated by the pickup ions via a resonant cyclotron instability. Close to the bow shock these waves are highly nonlinear, \DELTAB/B0\ approximately 1, and are propagating obliquely to the magnetic field. The interaction of cometary ions in the mass loaded solar wind with MS waves propagating away from the comet and oblique to the interplanetary magnetic field (IMF) is investigated using the test particle approach. Ion trajectories, distribution functions, widths of pitch angle scattering and energy diffusion are obtained. Because of the MS 'turbulence'', the particle velocity and acceleration are found to increase with increasing wave amplitude, inclination of the wave vector to the background magnetic field, and the range of resonant mode numbers. It is found that the interaction of water group pickup ions with MS waves propagating obliquely to the IMF gives larger pitch angle scattering and acceleration than that in the can of parallel and antiparallel propagating waves. In particular, obliquely propagating MS waves at angles greater than 40' to the ambient magnetic field are very effective at accelerating particles because of a high phase velocity along the magnetic field. In the case of monochromatic MS waves, Landau damping is found to play an important role; the particles get electromagnetically trapped in a potential well due to Landau damping. In the case of MS turbulence, the particles are stochastically heated and the temperature continues to grow linearly with time. We have also investigated the relationship between pitch angle scattering and the three parameters, namely, a, the angle between the solar wind flow direction and the ambient magnetic field, theta(Bk), the angle between the ambient magnetic field and the wave propagation vector, and the ion injection velocity. The pitch angle scattering rates are obtained using a monochrometic nonlinear MS wave as well as MS turbulence in both the quasi-parallel (0 < alpha < 60-degrees) and quasi-perpendicular (60-degrees < alpha < 90-degrees) regimes for various values of theta(Bk). In the case of a monochromatic MS wave, pitch angle scattering rates are found to change very slightly with respect to theta(Bk), a and the mode number of the MS wave due to their Landau damping. In the case of MHD turbulence the pitch angle scattering rates decrease with increasing a for theta(Bk) < 40-degrees and increase with increasing a for theta(Bk) > 40-degrees. They are found to be independent of the injection velocity. The results are in agreement with the observations. C1 DEF SCI RES ORG, INST SYST STUDIES & ANAL, DELHI, INDIA. RP JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 46 TC 3 Z9 3 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1993 VL 98 IS A12 BP 21023 EP 21037 DI 10.1029/93JA01748 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600014 ER PT J AU HUDDLESTON, DE NEUGEBAUER, M GOLDSTEIN, BE AF HUDDLESTON, DE NEUGEBAUER, M GOLDSTEIN, BE TI WATER GROUP ION DISTRIBUTIONS IN THE MIDCOMETOSHEATH OF COMET HALLEY SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID VELOCITY SPACE DIFFUSION; PICKUP IONS; MASS-SPECTROMETER; GIOTTO; PLASMA AB In the midcometosheath of comet Halley (1 X 10(5)-2 X 10(5) km from the nucleus) the center-of-mass plasma frame is approximately the bulk flow velocity of the cometary ions, and the Alfven wave speed is an appreciable fraction of the flow speed. Here, the peaks of the water group ion distributions observed by the Giotto ion mass spectrometer are at velocities consistently below the expected pickup speed. It is shown that this effect is consistent with the scattering of the new pickup ions onto a bispherical shell distribution. The model does not fit the data inside approximately 1.2 X 10(5) km, however, possibly as a result of the growing importance of collisions or the presence of other processes such as scattering on obliquely propagating magnetosonic waves. RP HUDDLESTON, DE (reprint author), JET PROP LAB,4800 OAK GROVE DR,MS 169-506,PASADENA,CA 91109, USA. NR 19 TC 5 Z9 5 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 1993 VL 98 IS A12 BP 21039 EP 21043 DI 10.1029/93JA02229 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600015 ER PT J AU SMITH, EJ WENZEL, KP AF SMITH, EJ WENZEL, KP TI INTRODUCTION TO THE ULYSSES ENCOUNTER WITH JUPITER SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID JOVIAN MAGNETOSPHERE; PLASMA TORUS; ENVIRONMENT; CONVECTION; FIELD; FLYBY; RADIO AB The Ulysses spacecraft encountered Jupiter in February 1992, passing within 6.31 radii of the planet. For approximately 8 days it was inside the Jovian magnetosphere, and for several days before and after that, Ulysses was in the interaction regions formed by the solar wind (the magnetosheath and boundary layer). The inbound trajectory was at a almost-equal-to 1000 LT and the outbound trajectory was at 1800 LT, that is, dusk, a unique feature of the flight path. Three regions interior to the magnetosphere were identified as on previous missions both inbound and outbound. In addition, the spacecraft twice penetrated a cusplike region at high latitude in the inner magnetosphere. Following closest approach, Ulysses traversed the Io plasma torus in basically a north-south direction. Although Ulysses is a heliospheric mission, the experiments were well suited to an investigation of Jupiter's magnetosphere and have returned much new information. This introduction to the accompanying articles by the Ulysses investigators provides basic information on the experiments, the spacecraft, and the trajectory. In addition, the scientific context of the encounter is reviewed on the basis of the preliminary analyses of the Ulysses observations and a rudimentary comparison with the earlier Pioneer and Voyager results. Some important scientific questions raised by the encounter, along with some tentative answers, are presented. C1 EUROPEAN SPACE AGCY,EUROPEAN SPACE RES & TECHNOL CTR,DEPT SPACE SCI,2200 AG NOORDWIJK,NETHERLANDS. RP SMITH, EJ (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 37 TC 19 Z9 19 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 1993 VL 98 IS A12 BP 21111 EP 21127 DI 10.1029/93JA02584 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600023 ER PT J AU LIN, NG KELLOGG, PJ MACDOWALL, RJ MEI, Y CORNILLEAUWEHRLIN, N CANU, P DEVILLEDARY, C REZEAU, L BALOGH, A FORSYTH, RJ AF LIN, NG KELLOGG, PJ MACDOWALL, RJ MEI, Y CORNILLEAUWEHRLIN, N CANU, P DEVILLEDARY, C REZEAU, L BALOGH, A FORSYTH, RJ TI ULF WAVES IN THE IO TORUS - ULYSSES OBSERVATIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID 1-2 MAGNETIC PULSATIONS; CYCLOTRON WAVES; PLASMA TORUS; EQUATORIAL MAGNETOSPHERE; PARTICLE INTERACTIONS; JOVIAN MAGNETOSPHERE; INSTABILITY; JUPITER; GENERATION; FREQUENCY AB Throughout the Io torus. Ulysses has observed intense ULF wave activity in both electric and magnetic components. Such ULF waves have been previously suggested as the source of ion precipitation leading to Jovian aurorae. The peaks of the wave spectra are closely related to the ion cyclotron frequencies, which is evidence of the waves being ion cyclotron waves (ICWs). Analysis of the dispersion relation using a multicomponent density model shows that at high latitudes (approximately 30-degrees), peak frequencies of the waves fall into L mode branches of guided or unguided ICWs. Near the equator, in addition to the ICWs below f(cO++), there are strong signals at approximately 10 Hs which require an unexpectedly large energetic ion temperature anisotropy to be explained by the excitation of either convective or nonconvective ion cyclotron instabilities. Their generation mechanism remains open for the future study. Evaluation of the Poynting vector and the dispersion relation analysis suggest that the waves near the equator had a small wave angle relative to the magnetic field, while those observed at high latitudes were more oblique. The polarization of the waves below f(cH+) is more random than that of the whistler mode waves, but left-hand-polarized components of the waves can still be seen. The intensity of the ICWs both near the equator and at high latitudes are strong enough to meet the requirement for producing strong pitch angle scattering of energetic ions. C1 UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,LOS ANGELES,CA 90024. CTR NATL ETUD TELECOMMUN,CTR RECH PHYS ENVIRONM,F-92131 ISSY MOULINEAUX,FRANCE. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,LONDON SW7 2AZ,ENGLAND. UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN 55455. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP LIN, NG (reprint author), UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN 55455, USA. RI MacDowall, Robert/D-2773-2012 NR 25 TC 12 Z9 12 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 1993 VL 98 IS A12 BP 21151 EP 21162 DI 10.1029/93JA02593 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600026 ER PT J AU FARRELL, WM MACDOWALL, RJ HESS, RA KAISER, ML DESCH, MD STONE, RG AF FARRELL, WM MACDOWALL, RJ HESS, RA KAISER, ML DESCH, MD STONE, RG TI AN INTERPRETATION OF THE BROAD-BAND VLF WAVES NEAR THE IO TORUS AS OBSERVED BY ULYSSES SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RADIO ASTRONOMY OBSERVATIONS; SPACELAB-2 ELECTRON-BEAM; WHISTLER-MODE RADIATION; AURORAL HISS; INNER MAGNETOSPHERE; POLAR MAGNETOSPHERE; PLASMA OBSERVATIONS; JUPITER; VOYAGER-1; ENVIRONMENT AB The requirements for the Ulysses trajectory to attain high ecliptic latitudes using a Jovian gravitational assist resulted in a fortuitous passage through the Io torus region. Specifically, the spacecraft spent many hours at latitudes just above the torus. During this time the low-frequency cutoff of an ordinary mode (O mode) emission allowed a determination of the local electron plasma frequency (i.e., electron density) along the northern flank of the torus. Also, near a Jovian System III longitude of 100-degrees, the spacecraft flew past a set of active field lines that have been previously identified to be associated with the hectometric generation region. During the passage, Ulysses observed a newly discovered O mode component and a whistler mode emission similar to that observed by Voyager 1 13 years previously. All of the broadband VLF emissions imply the presence of a particular population of electrons. We suggest that broadband VLF emissions can be used as a ''particle detector'' to qualitatively measure the electron plasma conditions in the torus region and identify active regions. C1 HUGHES STX,LANHAM,MD 20706. RP FARRELL, WM (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. RI MacDowall, Robert/D-2773-2012; Farrell, William/I-4865-2013 NR 50 TC 16 Z9 16 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 1993 VL 98 IS A12 BP 21177 EP 21188 DI 10.1029/93JA02591 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600028 ER PT J AU PHILLIPS, JL BAME, SJ THOMSEN, MF GOLDSTEIN, BE SMITH, EJ AF PHILLIPS, JL BAME, SJ THOMSEN, MF GOLDSTEIN, BE SMITH, EJ TI ULYSSES PLASMA OBSERVATIONS IN THE JOVIAN MAGNETOSHEATH SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTHS BOW SHOCK; ION DISTRIBUTIONS; DAYSIDE MAGNETOSHEATHS; JUPITER; SATURN; FLYBY AB The solar wind plasma experiment aboard the Ulysses spacecraft, including separate ion and electron instruments, measured the plasma properties of the Jovian magnetosheath during the February 1992 encounter with Jupiter. Seven separate magnetosheath intervals were observed, as well as four bow shock crossings and numerous encounters with the magnetopause and its boundary layer. We present an overview of ion and electron bulk parameters and a sampling of distribution shapes for the magnetosheath and adjacent plasma regions. Plasma flows are generally appropriate for slowing and deflection of the solar wind flow about a relatively stationary obstacle, with the notable exception of the first inbound sheath transit, when an expanding magnetosphere resulted in sunward flow just above the magnetopause. The existence of a planetary depletion layer is suggested by trends in plasma density for some magnetopause encounters. The magnetopause boundary layer is characterized by a combination of sheathlike and magnetospheric distributions of both ions and electrons. The ion population in the sheath is observed to include a significant population of suprathermal protons. Electron distributions have a distinctive shape previously observed in the terrestrial magnetosheath, with fluxes parallel to the magnetic field dominating at thermal energies and perpendicular fluxes dominating at higher energies. Trends in electron temperature near the bow shock indicate that shock motion plays an important role in heating the electrons. In general, the plasma characteristics of the Jovian magnetosheath are quite similar to those in its terrestrial counterpart, but the compressible nature of the Jovian magnetosphere accentuates the importance of boundary motions. C1 JET PROP LAB,PASADENA,CA 91109. RP PHILLIPS, JL (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 21 TC 24 Z9 24 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 1993 VL 98 IS A12 BP 21189 EP 21202 DI 10.1029/93JA02592 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600029 ER PT J AU TSURUTANI, BT SOUTHWOOD, DJ SMITH, EJ BALOGH, A AF TSURUTANI, BT SOUTHWOOD, DJ SMITH, EJ BALOGH, A TI A SURVEY OF LOW-FREQUENCY WAVES AT JUPITER - THE ULYSSES ENCOUNTER SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID JOVIAN BOW SHOCK; MAGNETOPAUSE BOUNDARY-LAYER; MAGNETOSHEATH LION ROARS; ION-CYCLOTRON WAVES; EARTHS MAGNETOSHEATH; MIRROR WAVES; HYDROMAGNETIC-WAVES; MAGNETOSONIC WAVES; PLASMA-WAVES; SOLAR-WIND AB We report the results of a survey of low-frequency (LF) plasma waves detected during the Ulysses Jupiter flyby. In the Jovian foreshock, two predominant wave periods are detected: 10(2)-s and 5-s, as measured in the spacecraft frame. The 10(2)-s waves are highly nonlinear propagate at large angles to B(o) over arrow pointing right (typically 50-degrees), are steepened, and sometimes have attached whistler packets. For the interval analyzed the 10(2)-s waves had mixed right-and left-hand polarizations. We argue that these are all consistent with being right-hand magnetosonic waves in the solar wind frame. The 10(2)-s waves with attached whistlers are similar to cometary waves. The trailing portions are linearly polarized and the whistler portions circularly polarized with amplitudes decreasing linearly with time. The emissions are generated by approximately 2-keV protons flowing from the Jovian bow shock/magnetosheath into the upstream region. The inability is the ion beam instability. Higher Z ions were considered as a source of the waves but have been ruled out because of the low sunward velocities needed for their resonance. The 5-s waves have DELTAB over arrow pointing right/ B(o) almost-equal-to 0.5, are compressive and are left-hand polarized in the spacecraft frame. Local generation by three different resonant interactions were considered and have been ruled out. One possibility is that these waves are whistler mode by-products of the steepened lower-frequency magnetosonic waves. Mirror mode structures were detected throughout the outbound magnetosheath passes. For these structures, the theta(kB) values were consistently in the range of 80-degrees to 90-degrees, exceptionally high values. Assuming 1-keV protons, the spacing between the magnetic decreases is approximately 10-20 r(p). Close to the magnetopause, small amplitudes (DELTAB over arrow pointing right/B(o) almost-equal-to 0.15), transverse waves were detected. Within the wave packet, right, left- and linear polarizations were found. These may be similar to waves detected in the Earth's plasma depletion layer. Within the Jovian low-latitude boundary layer, enhanced transverse spectral power was detected at frequencies just below the proton cyclotron frequency. A total magnetic power of 10(-1) nT2 was determined. Cross-field diffusion of approximately 1-keV protons yields a calculated boundary layer thickness of 0.15 R(J). This is in excellent agreement with previous measurements. Transverse left-hand (spacecraft frame) waves were detected within the Jovian magnetosphere. These waves have periods of 5-8 min, are elliptically to circularly polarized and propagate in a range of 10-degrees to 43-degrees relative to B(o) over arrow pointing right. It is most likely that these waves are generated by an ion beam instability. Assuming S+, we get a resonant parallel energy of 60 keV. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND. RP JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 73 TC 59 Z9 59 U1 4 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1993 VL 98 IS A12 BP 21203 EP 21216 DI 10.1029/93JA02586 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600030 ER PT J AU FAIRFIELD, DH AF FAIRFIELD, DH TI SOLAR-WIND CONTROL OF THE DISTANT MAGNETOTAIL - ISEE-3 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETIC-FIELD; GEOMAGNETIC TAIL; PLASMA; CONVECTION; AVERAGE AB During a 40-day period in 1983, ISEE 3 was located about 225R(E) behind the Earth and remained within 12 R(E) of the nominal tail axis. During this time the spacecraft spent at least 70% of its time in the magnetotail with occasional excursions into the magnetosheath. However, during five geomagnetically disturbed intervals of 1-3 days duration during this period, ISEE 3 remained within the magnetosheath for extended intervals, even when it was very near the center of an average tail. Simultaneous observations of the solar wind direction and thermal pressure suggest that nonradial solar wind flow associated with interacting solar wind streams moves a compressed tail away from the nominal position at these Limes and explains most of these observations. However, during several few-hour intervals of strongly northward interplanetary magnetic field (IMF) within these periods, the solar wind is more radial and cannot explain the residence of the spacecraft in the magnetosheath. At these times ISEE 3 seems to be moving back and forth between two regions, one a higher-density, lower-temperature magnetosheathlike region but with density somewhat lower than the normal magnetosheath, the other a lower-density, higher-temperature taillike region but with density higher than the normal tail. Both regions have large B(z) components and B(x) components that tend to vary as if the spacecraft were moving from one hemisphere of the tail to the other. It is suggested that the magnetotail at these times of northward IMF consists mostly of field lines that close Earthward of the spacecraft with a narrow remaining tail at 225 R(E) waving back and forth across the spacecraft. This suggestion is supported by recent MHD simulations of J. A. Fedder and J. G. Lyon (submitted manuscript) for northward IMF conditions that show a completely closed tail that extends only to 155 R(E). If relatively rare intervals of long-duration, very northward IMF can eliminate the extended tail, it seems likely that more common, less northward IMF might well have very important, though less drastic, effects on the tail configuration. RP FAIRFIELD, DH (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,CODE 695,GREENBELT,MD 20771, USA. NR 22 TC 50 Z9 51 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 1993 VL 98 IS A12 BP 21265 EP 21276 DI 10.1029/93JA01847 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600036 ER PT J AU WU, BH MANDT, ME LEE, LC CHAO, JK AF WU, BH MANDT, ME LEE, LC CHAO, JK TI MAGNETOSPHERIC RESPONSE TO SOLAR-WIND DYNAMIC PRESSURE VARIATIONS - INTERACTION OF INTERPLANETARY TANGENTIAL DISCONTINUITIES WITH THE BOW SHOCK SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GENERATION; VORTICES; UPSTREAM; FIELD; FLUX AB Some magnetic impulse events observed in the polar region are related to vortices associated with plasma convection in the ionosphere. Recent analyses of satellite and ground data suggest that the interaction of solar wind dynamic pressure pulses and the magnetosphere may lead to the formation of velocity vortices in the magnetopause boundary layer region. This can in turn lead to the presence of vortices in the polar ionosphere. However, before reaching the Earth's magnetopause, the interplanetary pressure pulses must interact with and pass through the bow shock. A variation of the solar wind dynamic pressure (DELTArhoV2) may be associated with shocks, magnetic holes, or tangential discontinuities (TDs) in the interplanetary medium. We study the interaction of interplanetary TDs with the Earth's bow shock (BS) using both theoretical analysis and MHD computer simulations. It is found that as a result of the collision between a TD and the BS, the jump in the solar wind dynamic pressure associated with the TD is significantly modified, the bow shock moves, and a new fast shock or fast rarefaction wave, which propagates in the downstream direction, is excited. Our theoretical analysis shows that the change in the p density across the interplanetary TD plays the most important role in the collision process. Iu the case with an enhanced dynamic pressure behind the interplanetary TD, the bow shock is intensified in strength and moves in the earthward direction. The dynamic pressure jump associated with the transmitted TD is generally reduced from the value before the interaction. A fast compressional shock is excited ahead of the transmitted TD and propagates toward the Earth's magnetosphere. For the case in which the dynamic pressure is reduced behind the interplanetary TD, the pressure jump across the transmitted TD is substantially weakened, the bow shock moves in the sunward direction, and a rarefaction wave which propagates downstream is excited. We also simulate and discuss the interaction of a pair of tangential discontinuities, which may correspond to a magnetic hole, with the BS. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RP NATL CENT UNIV, INST SPACE SCI, CHUNGLI, TAIWAN. RI Lee, Lou-Chuang/I-2588-2013 OI Lee, Lou-Chuang/0000-0003-4012-991X NR 45 TC 36 Z9 36 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1993 VL 98 IS A12 BP 21297 EP 21311 DI 10.1029/93JA01013 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600039 ER PT J AU CORONITI, FV GREENSTADT, EW MOSES, SL SMITH, EJ TSURUTANI, BT AF CORONITI, FV GREENSTADT, EW MOSES, SL SMITH, EJ TSURUTANI, BT TI PLASMA-WAVES DOWNSTREAM OF WEAK COLLISIONLESS SHOCKS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTHS BOW SHOCK; ELECTROSTATIC-WAVES; FORESHOCK REGION; SOLAR-WIND; TURBULENCE; UPSTREAM; MAGNETOSHEATH AB In September 1983 the ISEE 3/ICE spacecraft made a long traversal of the distant dawnside flank region of the Earth's magnetosphere and had many encounters with the low Mach number bow shock. These weak shocks excite plasma wave electric field turbulence with amplitudes comparable to those detected in the much stronger bow shock near the nose region. Downstream of quasi-perpendicular (quasi-parallel) shocks, the E field spectra exhibit a strong peak (plateau) at midfrequencies (1-3 kHz); the plateau shape is produced by a low-frequency (100-300 Hz) emission which is more intense behind quasi-parallel shocks. Polarization measurements made in the very steady magnetic field conditions downstream of two quasi-perpendicular shocks show that the low frequency signals are polarized parallel to the magnetic field, whereas the midfrequency emissions are unpolarized or only weakly polarized. A new high frequency (10-30 kHz) emission which is above the maximum Doppler shift frequency is clearly identified as a separate wave component. High time resolution spectra often exhibit a distinct peak at high frequencies; this peak is often blurred by the large amplitude fluctuations of the midfrequency waves. The high-frequency component is strongly polarized along the magnetic field and varies independently of the lower-frequency waves. C1 JET PROP LAB,PASADENA,CA 91109. RP CORONITI, FV (reprint author), TRW CO INC,SPACE & ELECTR GRP,REDONDO BEACH,CA 90278, USA. NR 21 TC 4 Z9 4 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 1993 VL 98 IS A12 BP 21451 EP 21462 DI 10.1029/93JA02281 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600050 ER PT J AU HANSON, WB COLEY, WR HEELIS, RA MAYNARD, NC AGGSON, TL AF HANSON, WB COLEY, WR HEELIS, RA MAYNARD, NC AGGSON, TL TI A COMPARISON OF IN-SITU MEASUREMENTS OF (E)OVER-RIGHT-ARROW AND -(V)OVER-RIGHT-ARROW X (B)OVER-RIGHT-ARROW FROM DYNAMICS EXPLORER-2 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTRIC-FIELDS; F-REGION; DE-2; IONOSPHERE; BEHAVIOR; DRIFTS AB Dynamics Explorer-2 provided the first opportunity to make a direct comparison of in situ measurements of the high-latitude convection electric field by two distinctly different techniques. The vector electric field instrument (VEFI) used antennae to measure the intrinsic electric fields and the ion drift meter (IDM) and retarding potential analyzer (RPA) measured the ion drift velocity vector, from which the convection electric field can be deduced. The data from three orbits having large electric fields at high latitude are presented, one at high, one at medium, and one at low altitudes. The general agreement between the two measurements of electric field is very good, with typical differences at high latitudes of the order of a few millivolts per meter, but there are some regions where the particle fluxes are extremely large (e.g., the cusp) and the disagreement is worse, probably because of IDM difficulties. The auroral zone potential patterns derived from the two devices are in excellent agreement for two of the cases, but not in the third, where bad attitude data may be the problem. At low latitudes there are persistent differences in the measurements of a few millivolts per meter, though these differences are quite constant from orbit to orbit. This problem seems to arise from some shortcoming in the VEFI measurements. Overall, however, these measurements confirm the concept of ''frozen-in'' plasma that drifts with velocity E over arrow pointing right x B over arrow pointing right/B2 within the measurement errors of the two techniques. C1 PHILLIPS LAB,GEOPHYS DIRECTORATE,BEDFORD,MA 01731. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP HANSON, WB (reprint author), UNIV TEXAS,CTR SPACE SCI,PHYS PROGRAM,MAIL STOP FO22,POB 830688,RICHARDSON,TX 75083, USA. NR 20 TC 15 Z9 15 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 JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1993 VL 98 IS A12 BP 21501 EP 21516 DI 10.1029/93JA01422 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK576 UT WOS:A1993MK57600055 ER PT J AU GOLIN, R KEIL, LC CHOU, L REID, IA AF GOLIN, R KEIL, LC CHOU, L REID, IA TI ACTIVATION OF RENAL R1 CHEMORECEPTORS INCREASES VASOPRESSIN CONCENTRATION IN RABBITS SO JOURNAL OF HYPERTENSION LA English DT Article; Proceedings Paper CT 6th European Meeting on Hypertension CY JUN 04-07, 1993 CL MILAN, ITALY SP UNIV MILANO, CTR FISCLIN & IPERTENS DE RENAL CHEMORECEPTORS; VASOPRESSIN; RENAL ISCHEMIA; RABBIT ID PLASMA; STIMULATION C1 UNIV CALIF SAN FRANCISCO,DEPT PHYSIOL,SAN FRANCISCO,CA 94143. AMES RES CTR,MOFFETT FIELD,CA. NR 7 TC 2 Z9 2 U1 0 U2 2 PU RAPID SCIENCE PUBLISHERS PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8NH SN 0263-6352 J9 J HYPERTENS JI J. Hypertens. PD DEC PY 1993 VL 11 SU 5 BP S182 EP S183 PG 2 WC Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA MR868 UT WOS:A1993MR86800070 PM 8158333 ER PT J AU CHOI, SR SALEM, JA AF CHOI, SR SALEM, JA TI FRACTURE-TOUGHNESS OF PMMA AS MEASURED WITH INDENTATION CRACKS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID STRENGTH; MODEL AB Fracture toughness of polymethyl methacrylate (PMMA) was evaluated with indentation cracks. The cracks were developed by indenting in a liquid acetone environment, as suggested by previous researchers. Due to the inconsistency in crack configurations with varying indentation loads and to the negligible residual stress from indentation, the application of the indentation strength method was limited in evaluating fracture toughness of PMMA. The semielliptical crack approximation, however, particularly at a low indentation load of 9.8 N, resulted in reasonable agreement with the value determined by three conventional fracture toughness testings using the compact tension (CT), double cantilever beam (DCB), and single edge notched beam (SENB) specimens. Measurements at other indentation load typically were in poor agreement with conventional methods due to poorly developed crack configurations. C1 CLEVELAND STATE UNIV,CLEVELAND,OH 44115. RP CHOI, SR (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 15 TC 10 Z9 10 U1 1 U2 4 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD DEC PY 1993 VL 8 IS 12 BP 3210 EP 3217 DI 10.1557/JMR.1993.3210 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA MK702 UT WOS:A1993MK70200028 ER PT J AU HAN, D KIM, YS NOZ, ME YEH, LW AF HAN, D KIM, YS NOZ, ME YEH, LW TI SYMMETRIES OF 2-MODE SQUEEZED STATES SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID QUANTUM AB It is known that the symmetry of two-mode squeezed states is governed by the group Sp(4) which is locally isomorphic to the O(3,2) de Sitter group. It is shown that this complicated ten-parameter group can be regarded as a product of two three-parameter Sp(2) groups. It is shown also that two coupled harmonic oscillators serve as a physical basis for the symmetry decomposition. It is shown further that the concept of entropy is needed when one of the two modes is not observed. The entropy is zero when the system is uncoupled. The system reaches thermal equilibrium when the entropy becomes maximal. C1 UNIV MARYLAND,DEPT PHYS,COLL PK,MD 20742. NYU,DEPT RADIOL,NEW YORK,NY 10016. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP HAN, D (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 902,GREENBELT,MD 20771, USA. NR 13 TC 15 Z9 15 U1 0 U2 4 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 1993 VL 34 IS 12 BP 5493 EP 5508 DI 10.1063/1.530318 PG 16 WC Physics, Mathematical SC Physics GA MJ909 UT WOS:A1993MJ90900006 ER PT J AU ADAMEC, D RIENECKER, MM VUKOVICH, JM AF ADAMEC, D RIENECKER, MM VUKOVICH, JM TI THE TIME-VARYING CHARACTERISTICS OF THE MERIDIONAL EKMAN HEAT-TRANSPORT FOR THE WORLD OCEAN SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Note ID ATMOSPHERE DATA SET; WIND STRESS; VARIABILITY; PACIFIC; ENERGY AB The time-varying meridional Ekman heat transport for the World Ocean is calculated for the 30-year period 1960-1989 using wind stress and sea surface temperature data from the Comprehensive Ocean-Atmosphere Data Set. The average monthly heat transports are dominated by poleward transport of heat in the tropical Pacific and Atlantic oceans. In the Indian Ocean, the strong monsoonal flow during summer is responsible for a large equatorward transport. If seasonal effects are removed, the tropical Pacific displays the most variance in Ekman heat transport and the Atlantic the least. Two sets of empirical orthogonal functions (EOFs) are computed to investigate the nonseasonal variability of the Ekman transport. The first set, which uses the eigenvector decomposition of the covariance matrix, emphasizes covariability in the world's tropical oceans. The time series of the EOF amplitudes contain a clear signal that can be directly related to El Nino. The El Nino signal is manifest as an increase in the equatorward transport of heat in the western Pacific followed by an increase in the poleward transport of heat in the eastern Pacific. The second set of EOFs, which highlights spatial oscillations only, shows the influence of zonal bands of wind stress and the large-scale patterns of Ekman suction/pumping. C1 NASA,GODDARD SPACE FLIGHT CTR,HYDORSPHER PROC LAB,GREENBELT,MD. UNIV MARYLAND,DEPT METEOROL,COLL PK,MD 20742. NR 20 TC 8 Z9 8 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD DEC PY 1993 VL 23 IS 12 BP 2704 EP 2716 DI 10.1175/1520-0485(1993)023<2704:TTVCOT>2.0.CO;2 PG 13 WC Oceanography SC Oceanography GA MM423 UT WOS:A1993MM42300012 ER PT J AU BROWN, CW YODER, JA AF BROWN, CW YODER, JA TI BLOOMS OF EMILIANIA-HUXLEYI (PRYMNESIOPHYCEAE) IN SURFACE WATERS OF THE NOVA-SCOTIAN SHELF AND THE GRAND BANK SO JOURNAL OF PLANKTON RESEARCH LA English DT Note ID CONTINENTAL-SHELF; MAINE; GULF AB High concentrations of the coccolithophorid Emiliania huxleyi (Lohm.) Hay et Mohler and/or its detached coccoliths occurred in or near high-reflectance patches observed in contemporaneous visible Advanced Very High Resolution Radiometer (AVHRR) imagery of the Nova Scotian Shelf and the Grand Bank. This is the first substantiated record of satellite-detected E.huxleyi blooms from these regions and extends our knowledge of their occurrence in the Western North Atlantic. The often large areal extent of these blooms, as determined previously from archived satellite imagery, suggests that they have a significant influence on the biogeochemistry and ecology of these regions. C1 UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. RP BROWN, CW (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 971,GREENBELT,MD 20771, USA. RI Brown, Christopher/B-8213-2008 OI Brown, Christopher/0000-0002-9905-6391 NR 19 TC 21 Z9 21 U1 0 U2 4 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD DEC PY 1993 VL 15 IS 12 BP 1429 EP 1438 DI 10.1093/plankt/15.12.1429 PG 10 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA MN280 UT WOS:A1993MN28000007 ER PT J AU MURRAY, M KURTZ, J AF MURRAY, M KURTZ, J TI NEAR-INFRARED ABSORPTIONS OF MONOMETHYLHYDRAZINE SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article AB The peak absorption coefficients for two near-infrared absorptions of monomethylhydrazine, CH3-N2H3, (MMH) were measured. Absorption bands located at 1.524 mum (6560 cm-1), 1.557 mum (6423 cm-1), and 1.583 mum (6316 cm-1) are assigned to the DELTAupsilon = 2 overtones of the infrared N-H stretching fundamentals at 3317, 3245 and 3177 cm-1. An absorption band located at 1.04 mum (9620 +/- 100 cm-1) is assigned to the DELTAupsilon = 3 overtone of one of these fundamentals. The peak absorption coefficients (alpha10) at 1.524 mum (6560 +/- 20 cm-1) and 1.04 mum (9620 +/- 100 cm-1) are 31 x 10(-2) and 0.97 x 10(-3) (cm atm)-1, respectively. Uncertainties in these coefficients were estimated to be less than +/-20% due primarily to uncertainties in the partial vapor pressure of MMH. C1 NASA,WHITE SANDS TEST FACIL,LOCKHEED ENGN & SCI CO,PO DRAWER MM,LAS CRUCES,NM 88004. NR 10 TC 3 Z9 3 U1 0 U2 1 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 1993 VL 50 IS 6 BP 585 EP 590 DI 10.1016/0022-4073(93)90025-D PG 6 WC Optics; Spectroscopy SC Optics; Spectroscopy GA MW489 UT WOS:A1993MW48900004 ER PT J AU SIROTA, JM REUTER, DC AF SIROTA, JM REUTER, DC TI ABSOLUTE INTENSITIES FOR THE Q-BRANCH OF THE 3-NU-2(-)NU-1 (465.161 CM-1) BAND OF NITROUS-OXIDE SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article AB The absolute intensities of four lines, Q15-Q18 in the 03(1)0-10(0)0 band, of N2O have been measured using a tunable diode laser spectrometer at temperatures between 380 and 420 K and pressures between 4 and 15 torr. Even though these transitions are weak and produced only about 2% of absorption at the line center for a pathlength of 52 m, they were measured with a signal to noise ratio of about 20 due to the high sensitivity of the instrument. The band strength derived is 1.03 x 10(-24) cm molec-1 at 296 K. RP SIROTA, JM (reprint author), NASA,GODDARD SPACE FLIGHT CTR,PLANETARY SYST BRANCH,CODE 693,GREENBELT,MD 20771, USA. NR 6 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 1993 VL 50 IS 6 BP 591 EP 594 PG 4 WC Optics; Spectroscopy SC Optics; Spectroscopy GA MW489 UT WOS:A1993MW48900005 ER PT J AU SHIPPONY, Z READ, WG AF SHIPPONY, Z READ, WG TI A HIGHLY ACCURATE VOIGT FUNCTION ALGORITHM SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID RAPID COMPUTATION AB A complex Voigt lineshape algorithm is presented whose maximum relative error over the complex plane is less than 1 x 10(-8). The algorithm consists of series, rational approximations and Gauss-Hermite integrations which makes it suitable as a general purpose software module for a wide variety of uses, including a Voigt function standard. RP SHIPPONY, Z (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 4 TC 32 Z9 34 U1 0 U2 8 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 1993 VL 50 IS 6 BP 635 EP 646 DI 10.1016/0022-4073(93)90031-C PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA MW489 UT WOS:A1993MW48900010 ER PT J AU MEARS, HC AF MEARS, HC TI OYSTER DISEASE RESEARCH (ODR) PROGRAM - ADMINISTERED BY THE NATIONAL-MARINE-FISHERIES-SERVICE, NORTHEAST REGION, 1990-1992 - PREFACE SO JOURNAL OF SHELLFISH RESEARCH LA English DT Editorial Material RP MEARS, HC (reprint author), NATL MARINE FISHERIES SERV,GLOUCESTER,MA 01930, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL SHELLFISHERIES ASSOC PI SOUTHAMPTON PA C/O DR. SANDRA E. SHUMWAY, NATURAL SCIENCE DIVISION, SOUTHAMPTON COLLEGE, SOUTHAMPTON, NY 11968 SN 0730-8000 J9 J SHELLFISH RES JI J. Shellfish Res. PD DEC PY 1993 VL 12 IS 2 BP 355 EP 357 PG 3 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA MX612 UT WOS:A1993MX61200024 ER PT J AU PIERCE, RB BLACKSHEAR, WT FAIRLIE, TD GROSE, WL TURNER, RE AF PIERCE, RB BLACKSHEAR, WT FAIRLIE, TD GROSE, WL TURNER, RE TI THE INTERACTION OF RADIATIVE AND DYNAMICAL PROCESSES DURING A SIMULATED SUDDEN STRATOSPHERIC WARMING SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION MODEL; MIDDLE ATMOSPHERE; SPECTRAL MODEL; INTEGRATIONS; MOMENTUM AB An analysis ofa spontaneous sudden stratospheric warming that occurred during a 2-year integration of the Langley Research Center Atmospheric Simulation Model is presented. The simulated warming resembles observed ''wave 1'' warmings in the Northern Hemisphere stratosphere and provides an opportunity to investigate the radiative and dynamical processes occurring during the warming event. Isentropic analysis of potential vorticity sources and sinks indicates that dynamically induced departures from radiative equilibrium play an important role in the warming event. Enhanced radiative cooling associated with a series of upper stratospheric warm pools leads to radiative dampening within the polar vortex. Within the ''surf zone'' large-scale radiative cooling leads to diabatic advection of high potential vorticity air from aloft. Lagrangian area diagnostics of the simulated warming agree well with LIMS analyses. Dynamical mixing is shown to account for the majority of the decrease in the size of the polar vortex during the simulated warming. An investigation of the nonlinear deformation of material lines that are initially coincident with diagnosed potential vorticity isopleths is conducted to clarify the relationship between the Lagrangian area diagnostics and potential vorticity advection during wave breaking events. C1 SCI & TECHNOL CORP,HAMPTON,VA. RP PIERCE, RB (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,THEORET STUDIES BRANCH,MAIL STOP 401B,HAMPTON,VA 23665, USA. RI Pierce, Robert Bradley/F-5609-2010 OI Pierce, Robert Bradley/0000-0002-2767-1643 NR 29 TC 21 Z9 21 U1 0 U2 0 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 1993 VL 50 IS 23 BP 3829 EP 3851 DI 10.1175/1520-0469(1993)050<3829:TIORAD>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ML248 UT WOS:A1993ML24800002 ER PT J AU MANNEY, GL RANDEL, WJ AF MANNEY, GL RANDEL, WJ TI INSTABILITY AT THE WINTER STRATOPAUSE - A MECHANISM FOR THE 4-DAY WAVE SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID POLAR STRATOSPHERE AB Studies using climatological fields in a three-dimensional stability model show unstable modes near the polar winter stratopause with periods near 4 days. The calculated modes exhibit equatorward momentum and heat fluxes near the stratopause, similar to characteristics of observed 4-day wave events, demonstrating that both baroclinic and barotropic processes are important for this instability. The baroclinic and barotropic components are considered separately by selectively removing either horizontal or vertical shear from the background flow. Although both situations reveal instability, growth rates are very slow; realistic growth rates occur only for climatological flows including both horizontal and vertical shears. Similar unstable, fast-moving waves are found near the polar stratopause for several winter months in both hemispheres. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. RP MANNEY, GL (reprint author), JET PROP LAB,MAIL STOP 183-701,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Randel, William/K-3267-2016 OI Randel, William/0000-0002-5999-7162 NR 13 TC 31 Z9 32 U1 0 U2 0 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 1993 VL 50 IS 23 BP 3928 EP 3938 DI 10.1175/1520-0469(1993)050<3928:IATWSA>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ML248 UT WOS:A1993ML24800008 ER PT J AU LANDIS, GA FATEMI, NS YOUNG, MJ BAILEY, SG AF LANDIS, GA FATEMI, NS YOUNG, MJ BAILEY, SG TI MASKLESS TEXTURE ETCHING OF GAAS SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Letter AB Chemical etches to produce a low-reflectance textured surface on GaAs surfaces were investigated. The Caros etch at 1.3 degrees C produced a fine (20 nm) random surface texture on GaAs. Reduced optical reflectivity was seen, with the greatest reduction occurring at short wavelength. RP LANDIS, GA (reprint author), NASA,LEWIS RES CTR,SVERDRUP TECHNOL INC,CLEVELAND,OH 44135, USA. NR 4 TC 1 Z9 1 U1 1 U2 4 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 1993 VL 140 IS 12 BP L183 EP L184 DI 10.1149/1.2221159 PG 2 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA MQ350 UT WOS:A1993MQ35000008 ER PT J AU RATNAKUMAR, BV ATTIA, AI SURAMPUDI, S HALPERT, G AF RATNAKUMAR, BV ATTIA, AI SURAMPUDI, S HALPERT, G TI A NEW REFERENCE ELECTRODE FOR NA/MCL(2) BATTERIES SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Letter ID ALCL3-NACL MELTS; SODIUM; ELECTROCHEMISTRY; CATHODES; CELL AB The use of aluminum as a reference electrode in the neutral and basic chloroaluminate molten salts poses certain problems related to the uncertainty and irreproducibility in the measured electrode potentials as well as lack of stability in tong-term studies. A new reference electrode based on an insoluble transition metal chloride, e.g., NiCl2 is proposed to address these problems. Ni/NiCl2 forms an electrode of the second kind with high exchange current density and long durability and would be an ideal choice for the electrochemical studies in neutral and basic chloroaluminate melts, including Na/NiCl2 cells. RP RATNAKUMAR, BV (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 17 TC 1 Z9 1 U1 1 U2 5 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 1993 VL 140 IS 12 BP L171 EP L172 DI 10.1149/1.2221154 PG 2 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA MQ350 UT WOS:A1993MQ35000003 ER PT J AU TAO, WK LANG, S SIMPSON, J ADLER, R AF TAO, WK LANG, S SIMPSON, J ADLER, R TI RETRIEVAL ALGORITHMS FOR ESTIMATING THE VERTICAL PROFILES OF LATENT-HEAT RELEASE - THEIR APPLICATIONS FOR TRMM SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article AB The latent heat release is a consequence of phase change (vapor, liquid and solid) of water. An algorithm has been developed (Tao et al., 1990) to estimate the latent heating of cloud systems as a function of their vertical hydrometeor profiles (termed a hydrometeor/heating algorithm). The derivation as well as the validation of the algorithm was based on results of a non-hydrostatic cloud model. The improvement of the hydrometeor/heating algorithm and its performance when tested on cloud systems which occurred in various geographic locations are discussed in this paper. Also the application of the hydrometeor/heating algorithm to incorporate surface precipitation as well as vertical hydrometeor profiles derived from multi-channel passive microwave rain retrieval algorithms is presented. The hydrometeor/heating algorithm requires information associated with the vertical profiles of various hydrometeors (ice and water). Although these vertical hydrometeor profiles can be derived from the TRMM radar directly and microwave sensors indirectly, the heating/hydrometeor algorithm needs to differentiate between large and small water/ice particles. Thus, a second retrieval algorithm (termed a convective-stratiform heating algorithm) has been developed. The inputs for this new algorithm are surface rainfall rates and amount of stratiform rain. This convective-stratiform heating algorithm also needs a look-up table which consists of latent heating profiles associated with various types of cloud systems at different geographic locations. The procedure as well as the performance of the convective-stratiform heating algorithm is discussed in this paper. RP TAO, WK (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ATMOSPHERES LAB, GREENBELT, MD 20771 USA. NR 0 TC 94 Z9 105 U1 1 U2 10 PU METEOROLOGICAL SOC JAPAN PI TOKYO PA C/O JAPAN METEOROLOGICAL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, 100-0004, JAPAN SN 0026-1165 EI 2186-9057 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD DEC PY 1993 VL 71 IS 6 BP 685 EP 700 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MU768 UT WOS:A1993MU76800004 ER PT J AU SIEBE, C ABRAMS, M SHERIDAN, MF AF SIEBE, C ABRAMS, M SHERIDAN, MF TI MAJOR HOLOCENE BLOCK-AND-ASH FAN AT THE WESTERN SLOPE OF ICE-CAPPED PICO-DE-ORIZABA VOLCANO, MEXICO - IMPLICATIONS FOR FUTURE HAZARDS SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID MOUNT-ST-HELENS; IZTACCIHUATL VOLCANO; EXPLOSIVE ERUPTIONS; PYROCLASTIC FLOWS; YOUNGER ANDESITES; RUIZ VOLCANO; MAGMA; PETROLOGY; LAHARS; AVALANCHES AB A major block-and-ash fan extends more than 14 km westward from the summit of Pico de Orizaba volcano in the eastern part of the Trans-Mexican Volcanic Belt. Radiocarbon dating of charcoal within the fan deposits yielded Holocene ages that range between 4040 +/- 80 and 4660 +/- 100 y.B.P. Stratigraphical, sedimentological, geochemical, and scanning electron microscope studies indicate that this fan originated within a relatively short time-span by multiple volcanic explosions at the summit crater. This activity produced a series of pyroclastic flows (mainly block-and-ash flows) and lahars which were channelized by a glacial cirque and connecting U-shaped valleys as they descended toward the base of the volcano. A recurrence of a similar eruption today would pose severe hazards to the population of more than 50,000 people, who live in a potentially dangerous zone. A detailed reconstruction of the sequence of events that led to the formation of the block-and-ash fan is presented to help mitigate the risk. Special attention is given to the effects of an ice-cap and the role of pre-existing glacial morphology on the distribution of products from such an eruption. C1 JET PROP LAB,PASADENA,CA 91109. SUNY BUFFALO,DEPT GEOL,BUFFALO,NY 14260. RP SIEBE, C (reprint author), NATL AUTONOMOUS UNIV MEXICO,INST GEOFIS,CIUDAD UNIV,MEXICO CITY 04510,DF,MEXICO. OI Siebe, Claus/0000-0002-3959-9028 NR 89 TC 32 Z9 32 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD DEC PY 1993 VL 59 IS 1-2 BP 1 EP 33 DI 10.1016/0377-0273(93)90075-3 PG 33 WC Geosciences, Multidisciplinary SC Geology GA MV462 UT WOS:A1993MV46200001 ER PT J AU KESZTHELYI, LP PIERI, DC AF KESZTHELYI, LP PIERI, DC TI EMPLACEMENT OF THE 75-KM-LONG CARRIZOZO LAVA FLOW-FIELD, SOUTH-CENTRAL NEW-MEXICO SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID MAGMATIC SILICATE LIQUIDS; THERMAL INFRARED IMAGES; KILAUEA VOLCANO; HAWAII; ERUPTION; AA; CRYSTALLIZATION; PAHOEHOE; LENGTHS; TOOL AB The Carrizozo Lava flow field is a young, 75-km-long, compound tube-fed pahoehoe flow field located in south-central New Mexico. Topographic channeling, unusually low viscosity, and fissure vents are ruled out as possible explanations for the length of the flow field. Effusion rates are estimated using: (1) a Bingham plastic model; (2) correlations between flow morphology and effusion rate; and (3) comparison with Hawaiian pahoehoe flows. The Bingham plastic model placed no useful restrictions on the effusion rate, while empirical and theoretical correlations gave estimates between 300 and 3 X 10(5) m3 s-1 for the effusion rate. The striking morphological similarity of the Carrizozo flow field to the compound tube-fed pahoehoe Kupaianaha flow field on Kilauea Volcano suggests an effusion rate of about 5 m3 s-1 and an eruption duration of nearly 3 decades. This long eruption duration and a long-lived lava tube system are interpreted to be the most important factors responsible for the length of the Carrizozo flow field. Furthermore, we conclude that the Bingham plastic model does not apply to tube-fed pahoehoe flow fields and that the correlation techniques grossly overestimate their effusion rates. This indicates that effusion rates may also have been overestimated for extra-terrestrial lava flows where it is has not been possible to distinguish between pahoehoe and 'a'a. C1 JET PROP LAB,DIV EARTH & SPACE SCI,PASADENA,CA 91109. RP KESZTHELYI, LP (reprint author), CALTECH,DIV GEOL & PLANETARY SCI,PASADENA,CA 91125, USA. NR 54 TC 45 Z9 45 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD DEC PY 1993 VL 59 IS 1-2 BP 59 EP 75 DI 10.1016/0377-0273(93)90078-6 PG 17 WC Geosciences, Multidisciplinary SC Geology GA MV462 UT WOS:A1993MV46200004 ER PT J AU BRILL, RW HOLTS, DB CHANG, RKC SULLIVAN, S DEWAR, H CAREY, FG AF BRILL, RW HOLTS, DB CHANG, RKC SULLIVAN, S DEWAR, H CAREY, FG TI VERTICAL AND HORIZONTAL MOVEMENTS OF STRIPED MARLIN (TETRAPTURUS-AUDAX) NEAR THE HAWAIIAN-ISLANDS, DETERMINED BY ULTRASONIC TELEMETRY, WITH SIMULTANEOUS MEASUREMENT OF OCEANIC CURRENTS SO MARINE BIOLOGY LA English DT Article ID BLUE MARLIN; MAKAIRA-NIGRICANS; TRACKING; DEPTH; FISH; DEVICES; TUNA AB We measured the vertical and horizontal movements of striped marlin (Tetrapturus audax) off the leeward coast of the Island of Hawaii between 20 November and 18 December 1992 while simultaneously gathering data on water temperature and oceanic currents. Fish movements were monitored by ultrasonic depth-sensitive transmitters, depth-temperature profiles by an expendable bathythermograph system, and oceanic current patterns by an acoustic Doppler current profiler. Like IndoPacific blue marlin (Makaira mazara), striped marlin near Hawaii spend >85% of their time in the mixed layer (i.e., above 90 m depth). The maximum depth for striped marlin appears to be limited by water temperatures 8C degrees colder than the mixed layer, rather than by an absolute lower temperature. We also found that the horizontal displacements of some striped marlin can be strongly influenced by currents. C1 NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA LAB,LA JOLLA,CA 92038. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,PHYSIOL RES LAB,LA JOLLA,CA 92093. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. RP BRILL, RW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 30 TC 89 Z9 91 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD DEC PY 1993 VL 117 IS 4 BP 567 EP 574 DI 10.1007/BF00349767 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA MM205 UT WOS:A1993MM20500005 ER PT J AU PIASCIK, RS GANGLOFF, RP AF PIASCIK, RS GANGLOFF, RP TI ENVIRONMENTAL FATIGUE OF AN AL-LI-CU ALLOY .2. MICROSCOPIC HYDROGEN CRACKING PROCESSES SO METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID ALUMINUM-ALLOYS; GROWTH; PROPAGATION; BEHAVIOR; TOUGHNESS; LONG AB Microscopic fatigue crack propagation (FCP) paths in peak-aged unrecrystallized alloy 2090 are identified as functions of intrinsic da/dN-DELTAK kinetics and environment. The FCP rates in longitudinal-transverse (LT)-oriented 2090 are accelerated by hydrogen-producing environments (pure water vapor, moist air, and aqueous NaCl), as defined in Part I. Subgrain boundary cracking (SGC) dominates for DELTAK values where the cyclic plastic zone is sufficient to envelop subgrains. At low DELTAK, when this crack tip process zone is smaller than the subgrain size, environmental FCP progresses on or near {100} or {110} planes based on etch-pit shape. For inert environments (vacuum and He) and pure O2 with crack surface oxidation, FCP produces large facets along {111} oriented slip bands. This mode does not change with DELTAK, and T1 decorated subgrain boundaries do not affect an expected da/dN-DELTAK transition for the inert environments. Rather, the complex dependence of da/dN on DELTAK is controlled by the environmental contribution to process zone microstructure-plastic strain interactions. A hydrogen embrittlement mechanism for FCP in 2090 is supported by similar brittle crack paths for low pressure water vapor and the electrolyte, the SGC and {100}/{110} crystallographic cracking modes, the influence of cyclic plastic zone volume (DELTAK), and the benignancy of O2. The SGC may be due to hydrogen production and trapping at T1 bearing sub-boundaries after process zone dislocation transport, while crystallographic cracking may be due to lattice decohesion or hydride cracking. C1 NASA,LANGLEY RES CTR,MECH MAT BRANCH,HAMPTON,VA 23681. RP PIASCIK, RS (reprint author), UNIV VIRGINIA,DEPT MAT SCI,CHARLOTTESVILLE,VA 22903, USA. NR 62 TC 26 Z9 26 U1 0 U2 6 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0360-2133 J9 METALL TRANS A PD DEC PY 1993 VL 24 IS 12 BP 2751 EP 2762 DI 10.1007/BF02666280 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA MM365 UT WOS:A1993MM36500016 ER PT J AU LEWIS, RD LOFGREN, GE FRANZEN, HF WINDOM, KE AF LEWIS, RD LOFGREN, GE FRANZEN, HF WINDOM, KE TI THE EFFECT OF NA VAPOR ON THE NA CONTENT OF CHONDRULES SO METEORITICS LA English DT Article ID DYNAMIC CRYSTALLIZATION; TEXTURES; SODIUM; MELTS AB Chondrules contain higher concentrations of volatiles (Na) than expected for melt droplets in the solar nebula. Recent studies have proposed that chondrules may have formed under non-canonical nebular conditions such as in particle/gas-rich dumps. Such chondrule formation areas may have contained significant Na vapor. To test the hypothesis of whether a Na-rich vapor would minimize Na volatilization reaction rates in a chondrule analog and maintain the Na value of the melt, experiments were designed where a Na-rich vapor could be maintained around the sample. A starting material with a melting point lower that typical chondrules was required to keep the logistics of working with Na volatilization from NaCl within the realm of feasiblity. The Knippa basalt, a MgO-rich alkali olivine basalt with a melting temperature of 1325-degrees +/- 5-degrees-C and a Na2O content of 3.05 wt%, was used as the chondrule analog. Experiments were conducted in a 1 atm, gas-mixing furnace with the fO2 controlled by a CO/CO2 gas mixture and fixed at the I-W buffer curve. To determine the extent of Na loss from the sample, initial experiments were conducted at high temperatures (1300-degrees-C - 1350-degrees-C) for duration of up to 72 h without a Na-rich vapor present. Almost all (up to 98%) Na was volatilized in runs of 72 h. Subsequent trials were conducted at 1330-degrees-C for 16 h in the presence of a Na-rich vapor, supplied by a NaCl-filled crucible placed in the bottom of the furnace. Succeeding Knudsen cell weight-loss mass-spectrometry analysis of NaCl determined the PN, for these experimental conditions to be in the 10(-6) atm range. This value is considered high for nebula conditions but is still plausible for non-canonical environments. In these trials the Na2O content of the glass was maintained or in some cases increased; Na2O values ranged from 2.62% wt to 4.37% wt. The Na content of chondrules may be controlled by the Na vapor pressure in the chondrule formation region. Most heating events capable of producing chondrules are sufficient to volatilize Na. Sodium volatilization reaction rates will be reduced to varying degrees from melt droplets, depending on the magnitude of the P(Na) generated. A combination of Na vapor during, and Na diffusion back into chondrules after, formation could maintain and/or enrich Na concentrations in chondrules. C1 NASA,JSC,HOUSTON,TX 77058. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP LEWIS, RD (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT GEOL & ATMOSPHER SCI,AMES,IA 50011, USA. NR 24 TC 31 Z9 31 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD DEC PY 1993 VL 28 IS 5 BP 622 EP 628 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ML322 UT WOS:A1993ML32200004 ER PT J AU BUCHANAN, PC ZOLENSKY, ME REID, AM AF BUCHANAN, PC ZOLENSKY, ME REID, AM TI CARBONACEOUS CHONDRITE CLASTS IN THE HOWARDITES BHOLGHATI AND EET87513 SO METEORITICS LA English DT Article ID INTERPLANETARY DUST PARTICLE; COMPOSITIONAL CLASSIFICATION; MATRIX MINERALOGY; AQUEOUS ACTIVITY; CR CHONDRITES; PARENT BODY; METEORITES; PHYLLOSILICATES; ORIGIN; PETROGRAPHY AB Twenty-two carbonaceous chondrite clasts from the two howardites Bholghati and EET87513 were analyzed. Clast N from EET7513 is a fragment classified as CM2 material on the basis of texture, bulk composition, mineralogy, and bulk O isotopic composition. Carbonaceous chondrite clasts from Bholghati, for which less data are available because of their small size, can be divided into two petrologic types: C1 and C2. C1 clasts are composed of opaque matrix with rare coarse-grained silicates as individual mineral fragments; textures resemble CI meteorites and some dark inclusions from CR meteorites. Opaque matrix is predominantly composed of flaky saponite; unlike typical CI and CR meteorites, serpentine is absent in the samples we analyzed. C2 clasts contain chondrules, aggregates, and individual fragments of coarse-grained silicates in an opaque matrix principally composed of saponite and anhydrous ferromagnesian silicates with flaky textures similar to phyllosilicates. These anhydrous ferromagnesian silicates are interpreted as the product of heating of pre-existing serpentine. The carbonaceous chondrite clasts we have studied from these two howardites are, with one notable exception (clast N from EET7513), mineralogically distinct from typical carbonaceous chondrites. However, these clasts have very close affinities to carbonaceous chondrites and have also experienced thermal metamorphism and aqueous alteration, but to different degrees. C1 NASA,LYNDON B JOHNSON SPACE CTR,DIV SOLAR SYST EXPLORAT,HOUSTON,TX 77058. RP BUCHANAN, PC (reprint author), UNIV HOUSTON,DEPT GEOSCI,HOUSTON,TX 77204, USA. NR 72 TC 39 Z9 39 U1 0 U2 4 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD DEC PY 1993 VL 28 IS 5 BP 659 EP 682 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ML322 UT WOS:A1993ML32200009 ER PT J AU MCCOY, TJ KEIL, K ASH, RD MORSE, AD PILLINGER, CT WIELER, R MAYEDA, TK CLAYTON, RN BENOIT, PH SEARS, DWG CASANOVA, I MUENOW, DW MOORE, CB LEWIS, CF WILSON, IE AF MCCOY, TJ KEIL, K ASH, RD MORSE, AD PILLINGER, CT WIELER, R MAYEDA, TK CLAYTON, RN BENOIT, PH SEARS, DWG CASANOVA, I MUENOW, DW MOORE, CB LEWIS, CF WILSON, IE TI ROOSEVELT COUNTY 075 - A PETROLOGIC, CHEMICAL AND ISOTOPIC STUDY OF THE MOST UNEQUILIBRATED KNOWN H CHONDRITE SO METEORITICS LA English DT Article ID TYPE-3 ORDINARY CHONDRITES; NOBLE-GASES; COSMOGENIC NUCLIDES; CARBON COMPONENTS; SILICON-CARBIDE; NANOMOLE LEVEL; OXYGEN ISOTOPE; METAMORPHISM; CHONDRULES; ALLENDE AB Roosevelt County (RC) 075 was recovered in 1990 as a single 258-gram stone. Classification of this meteorite is complicated by its highly unequilibrated nature and its severe terrestrial weathering, but we favor H classification. This is supported by O isotopes and estimates of the original Fe,Ni metal content. The O isotopic composition is similar to that of a number of reduced ordinary chondrites (eg., Cerro los Calvos, Willaroy), although RC 075 exhibits no evidence of reduced mineral compositions. Chondrule diameters are consistent with classification as an L chondrite, but large uncertainties in chondrule diameters of RC 075 and poorly constrained means of H, L and LL chondrites prevent use of this parameter for reliable classification. Other parameters are compromised by severe weathering (eg., siderophile element abundances) or unsuitable for discrimination between unequilibrated H, L and LL chondrites (eg., Co in kamacite, deltaC-13). Petrologic subtype 3.2 +/- 0.1 is suggested by the degree of olivine heterogeneity, the compositions of chondrule olivines, the thermoluminescence sensitivity, the abundances and types of chondrules mapped on cathodolumincscence mosaics, and the amount of presolar SiC. The meteorite is very weakly shocked (S2), with some chondrules essentially unshocked and, thus, is classified as an H3.2(S2) chondrite. Weathering is evident by a LREE enrichment due to clay contamination, reduced levels of many siderophile elements, the almost total loss of Fe,Ni metal and troilite, and the reduced concentrations of noble gases. Some components of the meteorite (eg., type IA chondrules, SiC) appear to preserve their nebular states, with little modification from thermal metamorphism. We conclude that RC 075 is the most unequilibrated H chondrite yet recovered and may provide additional insights into the origin of primitive materials in the solar nebula. C1 OPEN UNIV,DEPT EARTH SCI,PLANETARY SCI UNIT,MILTON KEYNES MK7 6AA,BUCKS,ENGLAND. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. ETH ZURICH,CH-8092 ZURICH,SWITZERLAND. UNIV ARKANSAS,DEPT CHEM & BIOCHEM,COSMOCHEM GRP,FAYETTEVILLE,AR 72701. NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. ARIZONA STATE UNIV,CTR METEORITE STUDIES,TEMPE,AZ 85287. UNIV HAWAII,DEPT CHEM,HONOLULU,HI 96822. UNIV HAWAII,HAWAII INST GEOPHYS,HONOLULU,HI 96822. RP MCCOY, TJ (reprint author), UNIV HAWAII,SCH OCEAN & EARTH SCI & TECHNOL,DEPT GEOL & GEOPHYS,HONOLULU,HI 96822, USA. RI Wieler, Rainer/A-1355-2010 OI Wieler, Rainer/0000-0001-5666-7494 NR 58 TC 10 Z9 10 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORITICS JI Meteoritics PD DEC PY 1993 VL 28 IS 5 BP 681 EP 691 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ML322 UT WOS:A1993ML32200012 ER PT J AU JONES, LR SMITH, A ANGELLINI, L AF JONES, LR SMITH, A ANGELLINI, L TI A DETAILED X-RAY AND RADIO STUDY OF THE SUPERNOVA REMNANT W44 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE ISM, INDIVIDUAL, W44; SUPERNOVA REMNANTS; RADIO CONTINUUM, INTERSTELLAR; X-RAY, INTERSTELLAR ID H-II REGIONS; NOVA REMNANTS; ABSORPTION-MEASUREMENTS; INTERSTELLAR-MEDIUM; GALACTIC PLANE; YOUNG; W28; POLARIZATION; MORPHOLOGIES; WAVELENGTH AB We analyse EXOSAT and Einstein Observatory X-ray spectra, an Einstein X-ray image and a detailed VLA radio map of the supernova remnant W44. The diffuse soft X-ray emission, which is only observed from the interior of the SNR, is shown to be largely of thermal origin. The absence of soft X-ray emission from the shell can be explained by the measured line-of-sight absorption, and provides an opportunity to study the SNR interior without confusion by bright shell emission. A deprojection of the interior X-ray surface brightness measured with the Einstein IPC is performed to derive density profiles which are relatively insensitive to the assumptions made. The density is found to decrease with radius by a factor of 3-4 between the centre and a fractional radius of 0.8. The interior density profiles are completely inconsistent with those predicted by the Sedov solution for expansion into a uniform medium, but can be largely explained in terms of expansion into a cloudy interstellar medium in which most of the mass resides in a cool dense state. Shocked and compressed clouds of gas of size almost-equal-to 0.4 to 8 pc in this state may be responsible for the numerous bright knots and filaments of radio emission revealed for the first time in our VLA map. A radio synchrotron nebula associated with the pulsar PSR 1853+01 may have been detected within the SNR. This proposed nebula is unusual because its position is offset from the pulsar, and in a direction consistent with motion of the pulsar away from the SNR centre. C1 UCL, MULLARD SPACE SCI LAB, DORKING RH5 6NT, SURREY, ENGLAND. NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA. UNIV SPACE RES ASSOCIAT, COLUMBIA, MD USA. RP JONES, LR (reprint author), UNIV SOUTHAMPTON, DEPT PHYS, SOUTHAMPTON SO9 5NH, HANTS, ENGLAND. NR 58 TC 28 Z9 28 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 1 PY 1993 VL 265 IS 3 BP 631 EP 640 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK501 UT WOS:A1993MK50100015 ER PT J AU KATZ, N QUINN, T GELB, JM AF KATZ, N QUINN, T GELB, JM TI GALAXY FORMATION AND THE PEAKS FORMALISM SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE METHODS, NUMERICAL; GALAXIES, CLUSTERING; GALAXIES, FORMATION; COSMOLOGY, THEORY; LARGE-SCALE STRUCTURE OF UNIVERSE ID COLD DARK MATTER; GAUSSIAN RANDOM-FIELDS; N-BODY SIMULATIONS; SPATIAL CORRELATIONS; REDSHIFT SURVEY; UNIVERSE; CLUSTERS; DENSITY; HALOS AB A large N-body simulation is used to compare the galaxies found by tagging peaks in the linear density field with the haloes that actually form. A variety of filters on the density field are tried in order to improve this correspondence, but none seems to do particularly well. The correlation function and velocity dispersion of the tagged peaks and the actual haloes also do not correspond very well. These comparisons bring into question the results of any study of galaxy formation that assumes that galaxies form at peaks in the initial density field, or simulations of large-scale structure that use the high-peak model to determine the galaxy distribution. C1 THEORET PHYS, OXFORD OX1 3NP, ENGLAND. NASA, CTR FERMILAB ASTROPHYS, BATAVIA, IL 60510 USA. RP MIT, DEPT PHYS, 6-214, CAMBRIDGE, MA 02139 USA. NR 27 TC 62 Z9 62 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 1 PY 1993 VL 265 IS 3 BP 689 EP 705 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MK501 UT WOS:A1993MK50100021 ER PT J AU MACHADO, LAT ROSSOW, WB AF MACHADO, LAT ROSSOW, WB TI STRUCTURAL CHARACTERISTICS AND RADIATIVE PROPERTIES OF TROPICAL CLOUD CLUSTERS SO MONTHLY WEATHER REVIEW LA English DT Article ID MESOSCALE CONVECTIVE COMPLEXES; ATLANTIC-OCEAN; VERTICAL MOTIONS; MOISTURE BUDGETS; CLIMATE-RESEARCH; NORTHERN SUMMER; MID-LATITUDE; SQUALL-LINE; LIFE-CYCLE; SYSTEMS AB By identifying individual tropical cloud clusters in eight months of the International Satellite Cloud Climatology Project data, the size distribution, average cloud properties, and their variation with system size in tropical convective systems (CS) is examined. The geographic distribution of CS shows a concentration over land areas in the summer hemisphere with little seasonal variation except for the major shift of location into the summer hemisphere. When the tropics are considered as a whole or a region is considered over a whole season, CS of all sizes (from individual convective towers at 2-20 km to the largest mesoscale systems at 200-2000 km) form a continuous size distribution where the area covered by the clouds in each size range is approximately the same. Land CS show a small excess of the smallest CS and a small deficit of the largest CS in comparison to ocean CS. Average CS cloud properties suggest two major cloud types: one with lower cloud-top pressures and much higher optical thicknesses, associated with deep convection, and one with higher cloud-top pressures and lower optical thicknessses, associated with the mesoscale stratiform anvil clouds. The anvil cloud properties show some evidence of a further division into optically thicker and thinner parts. The average properties of these clouds vary in a correlated fashion such that a larger horizontal extent of the convective system cloud is accompanied by a lower convective cloud-top pressure, larger anvil cloud size. and larger anvil cloud optical thickness. These structural properties and their diurnal variation also suggest that the smallest CS may represent a mixture of the formative and dissipating stages of CS, while the medium and large sizes are, principally, the mature stage. A radiative transfer model is used to evaluate the local radiative effects of CS with average cloud properties. The results imply that the mesoscale anvil cloud reinforces the diabatic heating of the atmosphere by the convection and may help sustain these systems at night. The radiative effects of the convective clouds, while unimportant to the total effect of the CS at the top of the atmosphere, may reinforce the diurnal variation of convection. Evaluating the radiative feedback of tropical cloudiness on climate is shown to be very difficult because of the significant diurnal and geographic variations of convective system cloud properties. C1 NASA,GODDARD SPACE FLIGHT CTR,NEW YORK,NY 10025. CTR TECN AEROESP,INST AERONAUT & ESPACO,S JOSE CAMPOS,SP,BRAZIL. RI Machado, Luiz/C-4314-2012; Rossow, William/F-3138-2015 OI Machado, Luiz/0000-0002-8243-1706; NR 78 TC 107 Z9 107 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD DEC PY 1993 VL 121 IS 12 BP 3234 EP 3260 DI 10.1175/1520-0493(1993)121<3234:SCARPO>2.0.CO;2 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ML344 UT WOS:A1993ML34400003 ER PT J AU YAO, MW DEGROH, H AF YAO, MW DEGROH, H TI 3-DIMENSIONAL FINITE-ELEMENT METHOD SIMULATION OF BRIDGMAN CRYSTAL-GROWTH AND COMPARISON WITH EXPERIMENTS SO NUMERICAL HEAT TRANSFER PART A-APPLICATIONS LA English DT Article ID NATURAL-CONVECTION AB The crystal growth of succinonitrile (SCN) in a horizontal Bridgman apparatus is studied through a three-dimensional numerical simulation. The governing equations considered include the steady state Navier-Stokes and the thermal energy equations. The temperature boundary conditions imposed at the outer surface of the glass ampoule are taken from experimental measurements. To model the phase change in SCN, we use the effective specific heat formulation of the enthalpy method and treat the SCN as a generalized Newtonian fluid. We solve the numerical model using the segregated solution approach provided by a commercial finite element code, FIDAP. The numerical results are compared with data from experiments, and very good agreement has been achieved. The advantages of applying the segregated solution approach in large-scale three-dimensional (3-D) computations are shown through detailed comparisons of efficiency and memory requirements between the segregated and the conventional fully coupled solution approaches. The significant savings of memory requirements by the segregated approach mate it possible to solve large-scale 3-D problems on work stations. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP YAO, MW (reprint author), OHIO AEROSP INST,2001 AEROSP PKWY,BROOKPARK,OH 44142, USA. NR 9 TC 16 Z9 16 U1 0 U2 3 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1040-7782 J9 NUMER HEAT TR A-APPL JI Numer. Heat Tranf. A-Appl. PD DEC PY 1993 VL 24 IS 4 BP 393 EP 412 DI 10.1080/10407789308902631 PG 20 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA MM083 UT WOS:A1993MM08300002 ER PT J AU CHAI, JC LEE, HS PATANKAR, SV AF CHAI, JC LEE, HS PATANKAR, SV TI RAY EFFECT AND FALSE SCATTERING IN THE DISCRETE ORDINATES METHOD SO NUMERICAL HEAT TRANSFER PART B-FUNDAMENTALS LA English DT Article ID RADIATIVE HEAT-TRANSFER; RECTANGULAR ENCLOSURES; ANISOTROPIC SCATTERING; CYLINDRICAL ENCLOSURES; TRANSPORT-EQUATION; MEDIA AB A discussion on the ray effect and false scattering occurring in discrete ordinates solution of the radiative transfer equation is presented in this article. Ray effect arises from the approximation of a continuously varying angular nature of radiation by a specified set of discrete angular directions. It is independent of the spatial discretization practice. False scattering, on the other hand, is a consequence of the spatial discretization practice and is independent of the angular discretization practice. In multidimensional computations, when a beam is not aligned with the grid line, false scattering smears the radiative intensity field. It reduces the appearance of unwanted bumps, but does not eliminate ray effect. An inappropriate view of false scattering is also presented. Four sample problems are used to explain these two effects. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. UNIV MINNESOTA,DEPT MECH ENGN,MINNEAPOLIS,MN 55455. RI Chai, John/A-3764-2010 NR 28 TC 187 Z9 196 U1 0 U2 12 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1040-7790 J9 NUMER HEAT TR B-FUND JI Numer Heat Tranf. B-Fundam. PD DEC PY 1993 VL 24 IS 4 BP 373 EP 389 DI 10.1080/10407799308955899 PG 17 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA MM078 UT WOS:A1993MM07800001 ER PT J AU TORR, DG TORR, MR ZUKIC, M SPANN, JF JOHNSON, RB AF TORR, DG TORR, MR ZUKIC, M SPANN, JF JOHNSON, RB TI ULTRAVIOLET IMAGER FOR THE INTERNATIONAL SOLAR-TERRESTRIAL PHYSICS MISSION SO OPTICAL ENGINEERING LA English DT Article; Proceedings Paper CT SPIE Conference on Instrumentation for Planetary and Terrestrial Atmospheric Remote Sensing CY JUL, 1992 CL SAN DIEGO, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS DE MAGNETOSPHERIC IMAGERY; ATMOSPHERIC REMOTE SENSING; EARTHS AURORA; GLOBAL COHERENT IMAGING; ENERGY FLUX ID NARROW-BAND; THIN-FILMS; FILTERS AB Imaging of the earth's auroral regions in the ultraviolet provides information on a global scale on the energy flux and characteristics of precipitating particles and on the composition of the atmosphere in which the energy is deposited. We report the design of an imager with 0.6-mrad angular resolution over an 8-deg field of view sampled with 39,500 pixels, yielding global auroral coherent imaging from above 6 R(E)(Earth radii). High-performance filters provide spectrally pure measurements of four key far-UV (FUV) features, with 5 x 10(-5) out-of-band rejection. Together with a solar blind intensified CCD detector, a net rejection of 10(-9) of all out-of-band emissions is achieved. The optical design comprises a three-mirror f/3 system that yields a noise equivalent sensitivity of 10 rayleighs (R) for a 37-s frame rate. The intrascene and interscene dynamic ranges are 1000 and 10(5), respectively. The optical surface microroughness is less than 2 nm, providing exceptionally low light scattering characteristics, allowing simultaneous observations of very weak and bright emissions. The imager should provide about two orders of magnitude improvement in performance over previous designs. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. UNIV ALABAMA,CTR APPL OPT,HUNTSVILLE,AL 35899. RP TORR, DG (reprint author), UNIV ALABAMA,CTR SPACE PLASMA & AERONOM,DEPT PHYS,HUNTSVILLE,AL 35899, USA. NR 6 TC 6 Z9 6 U1 0 U2 4 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 1993 VL 32 IS 12 BP 3060 EP 3068 DI 10.1117/12.149175 PG 9 WC Optics SC Optics GA ML621 UT WOS:A1993ML62100009 ER PT J AU ZUKIC, M TORR, DG KIM, JM SPANN, JF TORR, MR AF ZUKIC, M TORR, DG KIM, JM SPANN, JF TORR, MR TI FILTERS FOR THE INTERNATIONAL SOLAR-TERRESTRIAL PHYSICS MISSION FAR-ULTRAVIOLET IMAGER SO OPTICAL ENGINEERING LA English DT Article; Proceedings Paper CT SPIE Conference on Instrumentation for Planetary and Terrestrial Atmospheric Remote Sensing CY JUL, 1992 CL SAN DIEGO, CA SP SOC PHOTO OPT INSTRUMENTAT ENGINEERS DE MAGNETOSPHERIC IMAGERY; ATMOSPHERIC REMOTE SENSING; OPTICAL FILTERS; OPTICAL COATINGS ID VACUUM ULTRAVIOLET; NARROW-BAND; THIN-FILMS AB The far-ultraviolet (FUV) imager for the International Solar Terrestrial Physics (ISTP) Mission is designed to image four features of the aurora: O I lines at 130.4 and 135.6 nm and the N2 Lyman-Birge-Hopfield (LBH) bands between 140 and 160 nm (LBH long) and 160 and 180 nm (LBH long). We report the design and fabrication of narrowband and broadband filters for the ISTP FUV imager. Narrowband filters designed and fabricated for the O I lines have a bandwidth of less than 5 nm and a peak transmittance of 23.9 and 38.3% at 130.4 and 135.6 nm, respectively. Broadband filters designed and fabricated for LBH bands have the transmittance close to 60%. Blocking of out-of-band wavelengths for all filters is better than 5 x 10(-3)% with the transmittance at 121.6 nm of less than 10(-6)%. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP ZUKIC, M (reprint author), UNIV ALABAMA,CTR SPACE PLASMA & AERONOM RES,DEPT PHYS,OPT BLDG,SUITE 300,HUNTSVILLE,AL 35899, USA. NR 22 TC 17 Z9 17 U1 0 U2 1 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 1993 VL 32 IS 12 BP 3069 EP 3074 DI 10.1117/12.149192 PG 6 WC Optics SC Optics GA ML621 UT WOS:A1993ML62100010 ER PT J AU HESSE, M SMITH, MF HERRERO, F GHIELMETTI, AG SHELLEY, EG WURZ, P BOCHSLER, P GALLAGHER, DL MOORE, TE STEPHEN, TS AF HESSE, M SMITH, MF HERRERO, F GHIELMETTI, AG SHELLEY, EG WURZ, P BOCHSLER, P GALLAGHER, DL MOORE, TE STEPHEN, TS TI IMAGING ION OUTFLOW IN THE HIGH-LATITUDE MAGNETOSPHERE USING LOW-ENERGY NEUTRAL ATOMS SO OPTICAL ENGINEERING LA English DT Article DE MAGNETOSPHERIC IMAGERY ID SUPRATHERMAL O+ IONS; POLAR-CAP; PLASMA; ACCELERATION; SATELLITE; ESCAPE; STORM AB The measurement of neutral atom fluxes generated by charge exchange with the Earth's geocorona has recently been shown to provide the capability to image the magnetosphere. We investigate neutral oxygen fluxes produced by charge exchange from the cusp/cleft ion fountain population. Using an empirical cusp/cleft ion fountain model, an empirical variation of the geocoronal neutral hydrogen density with distance, and typical values for charge-exchange cross sections, line-of-sight integrations are performed to calculate the neutral oxygen flux at arbitrary locations in space. The resulting images are evaluated for a set of orbital positions of the proposed HI-LITE small explorer spacecraft. The resulting neutral oxygen fluxes are high enough for imaging with a low-energy neutral atom imaging instrument (ILENA) onboard the spacecraft. C1 LOCKHEED PALO ALTO RES LABS,SPACE SCI LAB,PALO ALTO,CA 94304. UNIV BERN,CH-3012 BERN,SWITZERLAND. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. UNIV DENVER,DENVER,CO 80208. RP HESSE, M (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 696,GREENBELT,MD 20771, USA. RI Hesse, Michael/D-2031-2012; Moore, Thomas/D-4675-2012 OI Moore, Thomas/0000-0002-3150-1137 NR 28 TC 7 Z9 7 U1 0 U2 1 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 1993 VL 32 IS 12 BP 3153 EP 3160 DI 10.1117/12.155256 PG 8 WC Optics SC Optics GA ML621 UT WOS:A1993ML62100023 ER PT J AU TOWNSEND, LW KHAN, F TRIPATHI, RK AF TOWNSEND, LW KHAN, F TRIPATHI, RK TI OPTICAL-MODEL ANALYSES OF 1.65 A GEV ARGON FRAGMENTATION - CROSS-SECTIONS AND MOMENTUM DISTRIBUTIONS SO PHYSICAL REVIEW C LA English DT Article ID RELATIVISTIC HEAVY-IONS; NUCLEUS-NUCLEUS COLLISIONS; ABRASION-ABLATION; PROJECTILES; ENERGIES; EMISSION; YIELDS AB An optical potential fragmentation model capable of predicting fragmentation cross sections and fragment momentum distributions is used to analyze recent measurements of 1.65 A GeV argon projectiles fragmenting in carbon and potassium-chloride targets obtained with the Heavy Ion Spectrometer System (HISS) at the Lawrence Berkeley Laboratory Bevalac. The theoretical model uses an abrasion-ablation-FSI (frictional spectator interaction) collision formalism to estimate elemental and isotopic production cross sections for comparsion with the measured values. The collision momentum transfer model is incorporated into a Goldhaber formalism to analyze measured transverse and longitudinal distributions of the projectile fragments. Good agreement between theory and experiment is obtained for all observables. C1 OLD DOMINION UNIV,NORFOLK,VA 23529. CHRISTOPHER NEWPORT UNIV,NEWPORT NEWS,VA 23606. RP TOWNSEND, LW (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 46 TC 9 Z9 9 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1993 VL 48 IS 6 BP 2912 EP 2919 DI 10.1103/PhysRevC.48.2912 PG 8 WC Physics, Nuclear SC Physics GA MM348 UT WOS:A1993MM34800042 PM 9969168 ER PT J AU ZHOU, Y VAHALA, G AF ZHOU, Y VAHALA, G TI RENORMALIZATION-GROUP ESTIMATES OF TRANSPORT-COEFFICIENTS IN THE ADVECTION OF A PASSIVE SCALAR BY INCOMPRESSIBLE TURBULENCE SO PHYSICAL REVIEW E LA English DT Article ID NAVIER-STOKES TURBULENCE; LARGE-EDDY SIMULATION; ISOTROPIC TURBULENCE; VISCOSITY; MODEL; DIFFUSION AB The advection of a passive scalar by incompressible turbulence is considered using recursive renormalization-group procedures in the differential subgrid shell thickness limit. It is shown explicitly that the higher-order nonlinearities induced by the recursive renormalization-group procedure preserve Galilean invariance. Differential equations, valid for the entire resolvable wave-number k range, are determined for the eddy viscosity and eddy diffusivity coefficients. It is shown that these higher-order nonlinearities do not contribute as k-->O, but play an essential role as k-->k(c), the cutoff wave number separating the resolvable scales from the subgrid scales. The transport coefficients and the associated eddy Prandtl number are in good agreement with the k-dependent transport coefficients derived from closure theories and experiments. C1 COLL WILLIAM & MARY,DEPT PHYS,WILLIAMSBURG,VA 23185. RP ZHOU, Y (reprint author), NASA,LANGLEY RES CTR,INST COMP APPLICAT SCI & ENGN,HAMPTON,VA 23681, USA. NR 31 TC 12 Z9 12 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD DEC PY 1993 VL 48 IS 6 BP 4387 EP 4398 DI 10.1103/PhysRevE.48.4387 PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA MQ164 UT WOS:A1993MQ16400036 ER PT J AU ERLEBACHER, G SARKAR, S AF ERLEBACHER, G SARKAR, S TI STATISTICAL-ANALYSIS OF THE RATE OF STRAIN TENSOR IN COMPRESSIBLE HOMOGENEOUS TURBULENCE SO PHYSICS OF FLUIDS A-FLUID DYNAMICS LA English DT Article ID NAVIER-STOKES TURBULENCE; 3-DIMENSIONAL TURBULENCE; ISOTROPIC TURBULENCE; VORTICITY FIELD; SCALAR GRADIENT; ALIGNMENT; FLOW; INTERMITTENCY; MODEL; FLUID AB Recent analysis of direct numerical simulations of compressible homogeneous shear flow turbulence has unraveled some of the energy transfer mechanisms responsible for the decrease of kinetic energy growth when the flow becomes more compressible. In this complementary study, attention is focused on the rate of strain tenser. A Helmholtz decomposition of the velocity field leads to a consideration of a solenoidal and an irrotational rate of strain tenser. Their eigenvalue distributions, eigenvector orientations, and the relative alignment between the eigenvectors and the vorticity and pressure gradient vectors are examined with the use of probability density functions. The irrotational rate of strain tenser is found to have a preferred structure in regions of strong dilatation. This structure depends on the mean shear, and is quite different from that of the solenoidal rate of strain tenser. Compressibility strongly affects the orientation properties of the pressure gradient vector. C1 UNIV CALIF SAN DIEGO, DEPT APPL MECH & ENGN SCI, LA JOLLA, CA 92093 USA. RP NASA, LANGLEY RES CTR, INST COMP APPLICAT SCI & ENGN, HAMPTON, VA 23665 USA. NR 35 TC 16 Z9 16 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0899-8213 J9 PHYS FLUIDS A-FLUID PD DEC PY 1993 VL 5 IS 12 BP 3240 EP 3254 DI 10.1063/1.858681 PG 15 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA MJ058 UT WOS:A1993MJ05800024 ER PT J AU GORMAN, CB MARDER, SR AF GORMAN, CB MARDER, SR TI AN INVESTIGATION OF THE INTERRELATIONSHIPS BETWEEN LINEAR AND NONLINEAR POLARIZABILITIES AND BOND-LENGTH ALTERNATION IN CONJUGATED ORGANIC-MOLECULES SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE NONLINEAR OPTICS; COMPUTATION; ELECTRIC FIELD; CYANINE; POLYENE ID OPTICAL POLARIZABILITIES; SEMIEMPIRICAL METHODS; CRYSTAL-STRUCTURE; CHEMICAL-SHIFTS; SUSCEPTIBILITY; OPTIMIZATION; PARAMETERS; SPECTRA; MODEL AB A computational method was devised to explore the relationship of charge separation, geometry, molecular dipole moment (mu), polarizability (alpha), and hyperpolarizabilities (beta, gamma) in conjugated organic molecules. We show that bond-length alternation (the average difference in length between single and double bonds in the molecule) is a key structurally observable parameter that can be correlated with hyperpolarizabilities and is thus relevant to the optimization of molecules and materials. By using this method, the relationship of bond-length alternation, mu, alpha, beta, and gamma for linear conjugated molecules is illustrated, and those molecules with maximized alpha, beta, and gamma are described. C1 CALTECH,BECKMAN INST,PASADENA,CA 91125. RP GORMAN, CB (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Gorman, Christopher/A-3463-2008 OI Gorman, Christopher/0000-0001-7367-2965 NR 36 TC 230 Z9 231 U1 4 U2 30 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 1 PY 1993 VL 90 IS 23 BP 11297 EP 11301 DI 10.1073/pnas.90.23.11297 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MK094 UT WOS:A1993MK09400085 PM 11607441 ER PT J AU WELTY, AD RAMSEY, LW IYENGAR, M NATIONS, HL BUZASI, DL AF WELTY, AD RAMSEY, LW IYENGAR, M NATIONS, HL BUZASI, DL TI A LONG-TERM STUDY OF H-ALPHA-LINE VARIATIONS IN FK COMAE BERENICES SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID BINARY; STARS AB We present observations of Halpha V/R ratio variations in FK Comae Berenices obtained during several observing seasons from 1981 to 1992. The raw Ha emission profile is always observed to be double peaked due to the stellar-absorption component. During most years the V/R ratio varies regularly with the period of the photometric light curve. The V/R periodicity is most obvious when time spans no longer than several stellar rotations are considered. We propose that the bulk of the emission component of the Halpha line arises in corotating circumstellar material that may be similar to that of a quiescent solar prominence. The lifetime of these structures appears to be on the order of weeks. A weak contribution from a circumstellar disk is evident and chromospheric emission may also be present. The appearance or disappearance of circumstellar structures over periods longer than a few weeks, or the total absence of such structures, blurs the more regular variations in Halpha seen over short time scales. Other more stochastic activity, such as flares, also clearly occurs. Phase shifts of the V/R ratio from year to year rule out the hypothesis that mass transfer in a close binary system is responsible for the V/R variations. C1 CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. COLL CHARLESTON,DEPT PHYS,CHARLESTON,SC 29424. JET PROP LAB,PASADENA,CA 91109. RP WELTY, AD (reprint author), PENN STATE UNIV,DEPT ASTRON & ASTROPHYS,UNIV PK,PA 16802, USA. NR 21 TC 8 Z9 8 U1 0 U2 1 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 1993 VL 105 IS 694 BP 1427 EP 1432 DI 10.1086/133325 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MP695 UT WOS:A1993MP69500006 ER PT J AU CARTER, GA MCCAIN, DC AF CARTER, GA MCCAIN, DC TI RELATIONSHIP OF LEAF SPECTRAL REFLECTANCE TO CHLOROPLAST WATER-CONTENT DETERMINED USING NMR MICROSCOPY SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID SHADE LEAVES; PLANT-LEAVES; SLASH PINE; INVIVO; IMAGES; VOLUME; LIGHT; SUN AB Nuclear Magnetic resonance (NMR) microscopy and reflectance spectroscopy were used to evaluate the response of leaf spectral reflectance to chloroplast relative water content (RWC). For sun and shade leaves of maple (Acer platanoides L. var Emerald Queen), NMR determined the distribution of water through the leaf thickness and changes in distribution as leaves dried from 100% RWC to approximately 70%, 50%, and 30% RWC. Chloroplast water could be resolved only in shade leaves. Leaf and chloroplast RWC were similar at leaf RWC of 80% or greater, but chloroplast RWC was as much as 12% greater than leaf RWC when leaf RWC decreased below 50%. In contrast, the RWC of nonchloroplast water compartments was as much as 12% less than leaf RWC. Reflectance responses to leaf water content were greatest in the water absorption bands near 1450 nm, 1950 nm, and 2500 nm wavelengths, and were minimal in the near-infrared from approximately 760-1300 nm. In the 400-760 nm (visible) range, reflectance sensitivity increased substantially as chloroplast RWC decreased. Peak visible reflectance sensitivity occurred near 695 nm and 670 nm for adaxial and abaxial surfaces, respectively, and was more closely related to chloroplast than to nonchloroplast or whole leaf RWC. C1 UNIV SO MISSISSIPPI,DEPT CHEM & BIOCHEM,HATTIESBURG,MS. RP CARTER, GA (reprint author), NASA,SCI & TECHNOL LAB,BAY ST LOUIS,MS 39529, USA. NR 22 TC 15 Z9 15 U1 1 U2 11 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 1993 VL 46 IS 3 BP 305 EP 310 DI 10.1016/0034-4257(93)90050-8 PG 6 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA MR044 UT WOS:A1993MR04400006 ER PT J AU WALTHALL, CL KIM, M WILLIAMS, DL MEESON, BW AGBU, PA NEWCOMER, JA LEVINE, ER AF WALTHALL, CL KIM, M WILLIAMS, DL MEESON, BW AGBU, PA NEWCOMER, JA LEVINE, ER TI DATA SETS FOR MODELING - A RETROSPECTIVE COLLECTION OF BIDIRECTIONAL REFLECTANCE AND FOREST ECOSYSTEMS DYNAMICS MULTISENSOR AIRCRAFT CAMPAIGN DATA SETS SO REMOTE SENSING OF ENVIRONMENT LA English DT Note ID FIELD EXPERIMENT FIFE AB The Biospheric Sciences Branch, within the Laboratory for Terrestrial Physics at NASA's Goddard Space Flight Center, has assembled two data sets for free dissemination to the remote sensing research community. One data set, referred to as the Retrospective Bidirectional Reflectance Distribution Function (BRDF) Data Collection, is a collection of bidirectional reflectance and supporting biophysical measurements of surfaces ranging in diversity from bare soil to heavily forested canopies. The other data collection, resulting from measurements made in association with the Forest Ecosystems Dynamics Multisensor Aircraft Campaign (FED MAC), contains data that are relevant to ecosystem process models, particularly those which have been modified to incorporate remotely sensed data. Both of these collections are being made available to the science community at large in order to facilitate model development, validation, and usage. These data collections are subsets which have been compiled and consolidated from individual researchers or from several large data set collections including: the First international Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE); FED MAC; the Superior National Forest Project (SNF); the Geologic Remote Sensing Field Experiment (GRSFE); and Agricultural Inventories through Space Applications of Remote Sensing (AgriStars). The complete, stand-alone FED MAC Data Collection contains atmospheric, vegetation, and soils data acquired during field measurement campaigns conducted at international Papers' Northern Experimental Forest located approximately 40 km north of Bangor, Maine. Reflectance measurements at the canopy, branch, and needle level are available, along with detailed canopy architectural measurements. Both the BRDF and FED MAC Data Collections are available on MS-DOS compatible 3.5-in. Floppy disks, along with detailed documentation of the instrumentation and methodology used to make the measurements, descriptions of the spatial and temporal coverage of thc data, quality assessment measures, and other description;e information required to use the data. A specialized MS-DOS software package has been developed to facilitate data archival and retrieval including graphing capability. C1 NASA,GODDARD SPACE FLIGHT CTR,TERR PHYS LAB,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,CTR GLOBAL CHANGE DATA,GREENBELT,MD. NASA,GODDARD SPACE FLIGHT CTR,HUGHES STX CORP,GREENBELT,MD. RP WALTHALL, CL (reprint author), UNIV MARYLAND,DEPT GEOG,GLOBAL REMOTE SENSING STUDIES LAB,1113 LEFRAK HALL,COLL PK,MD 20742, USA. NR 39 TC 10 Z9 11 U1 0 U2 2 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 1993 VL 46 IS 3 BP 340 EP 346 DI 10.1016/0034-4257(93)90054-2 PG 7 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA MR044 UT WOS:A1993MR04400010 ER PT J AU BARON, AE DANIELSON, JDS GOUTERMAN, M WAN, JR CALLIS, JB MCLACHLAN, B AF BARON, AE DANIELSON, JDS GOUTERMAN, M WAN, JR CALLIS, JB MCLACHLAN, B TI SUBMILLISECOND RESPONSE-TIMES OF OXYGEN-QUENCHED LUMINESCENT COATINGS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB An apparatus and data analysis methodology is described which allows determination of response time to oxygen concentration changes of luminescent oxygen sensor coatings. Utilizing a solenoid valve, a sample chamber creates a pressure jump from 0.1 to 700 Torr in 600 mus that is followed by 15 ms of ringing. An optical detection system measures the response of porphyrin-based luminescent oxygen sensors to the pressure jump. The pressure in the chamber is measured simultaneously and independently with a piezoresistive pressure transducer. Data analysis techniques using nonlinear least-squares and numerical convolution of the luminescent response to the pressure rise allow determination of response times of the oxygen sensor. The response to pressure jumps of several luminescent oxygen sensitive coatings designed for video luminescent barometry are measured with this computer-controlled instrument. Several coatings were studied with response times of approximately 2.5 s, approximately 400 ms, 11 ms, 1.5 ms, and <25 mus. Studies of the system suggest that we can determine response times down to about 10 mus. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP BARON, AE (reprint author), UNIV WASHINGTON,DEPT CHEM BG10,SEATTLE,WA 98195, USA. NR 13 TC 62 Z9 64 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD DEC PY 1993 VL 64 IS 12 BP 3394 EP 3402 DI 10.1063/1.1144310 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA MM177 UT WOS:A1993MM17700005 ER PT J AU TSO, KS BACKES, PG AF TSO, KS BACKES, PG TI A FAIL-SAFE TELE-AUTONOMOUS ROBOTIC SYSTEM FOR NUCLEAR-FACILITIES SO ROBOTICS AND COMPUTER-INTEGRATED MANUFACTURING LA English DT Article AB A fail-safe tele-autonomous robotic system is proposed for use in advanced nuclear reprocessing facilities. The design exploits the technologies developed for space telerobotics. The target system consists of a graphical user interface for an operator to execute robotic tasks, hand controllers for teleoperation, a three-dimensional graphical simulator, and robot control software to drive both the graphical simulation and dual six degree-of-freedom robots to perform tasks using autonomous, teleoperated, and shared control modes. A preliminary design for a safety monitoring system for fail-safe operations is also described. C1 SOHAR INC, 8421 WILSHIRE BLVD, SUITE 201, BEVERLY HILLS, CA USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP BACKES, PG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0736-5845 EI 1879-2537 J9 ROBOT CIM-INT MANUF JI Robot. Comput.-Integr. Manuf. PD DEC PY 1993 VL 10 IS 6 BP 423 EP 428 DI 10.1016/0736-5845(93)90005-5 PG 6 WC Computer Science, Interdisciplinary Applications; Engineering, Manufacturing; Robotics SC Computer Science; Engineering; Robotics GA NV397 UT WOS:A1993NV39700005 ER PT J AU GEHRELS, N FICHTEL, CE FISHMAN, GJ KURFESS, JD SCHONFELDER, V AF GEHRELS, N FICHTEL, CE FISHMAN, GJ KURFESS, JD SCHONFELDER, V TI THE COMPTON-GAMMA-RAY-OBSERVATORY SO SCIENTIFIC AMERICAN LA English DT Article C1 MAX PLANCK INST EXTRATERR PHYS,GAMMA RAY ASTRON GRP,GARCHING,GERMANY. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. NASA,GODDARD SPACE FLIGHT CTR,GAMMA RAY ASTROPHYS BRANCH,GREENBELT,MD 20771. USN,RES LAB,GAMMA & COSMIC RAY ASTROPHYS BRANCH,WASHINGTON,DC 20375. RP GEHRELS, N (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. RI Gehrels, Neil/D-2971-2012 NR 5 TC 22 Z9 22 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 1993 VL 269 IS 6 BP 68 EP & PG 0 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MG629 UT WOS:A1993MG62900025 ER PT J AU ADAMS, M SOLANKI, SK HAGYARD, M MOORE, RL AF ADAMS, M SOLANKI, SK HAGYARD, M MOORE, RL TI A SEARCH FOR SUNSPOT CANOPIES USING A VECTOR MAGNETOGRAPH SO SOLAR PHYSICS LA English DT Article ID MAGNETIC-FIELDS; LINES AB Using a magnetograph, we examine four sunspots for evidence of a magnetic canopy at the penumbra/photosphere boundary. The penumbral edge is determined from the photometric intensity and is defined to correspond to the value of the average intensity minus twice the standard deviation from the average. From a comparison of the location of this boundary with the location of contours of the vertical and horizontal components of the magnetic field, we conclude that the data are best represented by canopy-type fields close to all four sunspots. There is some evidence that the magnetic inclination in the canopies is 5 degrees-15 degrees with respect to the horizontal and that the canopy base height lies in the middle/upper photosphere. The observations further suggest that the magnetic canopy of a sunspot begins at its outer penumbral boundary. C1 ETH ZENTRUM,INST ASTRON,CH-8092 ZURICH,SWITZERLAND. RP ADAMS, M (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812, USA. RI Solanki, Sami/E-2487-2013 OI Solanki, Sami/0000-0002-3418-8449 NR 20 TC 11 Z9 11 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 1993 VL 148 IS 2 BP 201 EP 218 DI 10.1007/BF00645086 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML851 UT WOS:A1993ML85100003 ER PT J AU WALKER, ABC DEFOREST, CE HOOVER, RB BARBEE, TW AF WALKER, ABC DEFOREST, CE HOOVER, RB BARBEE, TW TI THERMAL AND DENSITY STRUCTURE OF POLAR PLUMES .1. ANALYSIS OF EUV OBSERVATIONS WITH A MULTILAYER CASSEGRAIN TELESCOPE SO SOLAR PHYSICS LA English DT Article ID SPECTRUM AB Normal incidence multilayer coated EUV/XUV optical systems provide a powerful technique for the study of the structure of the solar corona. Such systems permit the imaging of the full solar disk and corona with high angular resolution in narrow wavelength bands that are dominated by a single line or a line multiplet excited over a well defined range of temperatures. We have photometrically analysed, and derived temperature and density information from, images of polar plumes obtained with a multilayer Cassegrain telescope operating in the wavelength interval lambda = 171 to 175 Angstrom, which is dominated by FeIx and Fex emission. This observation was obtained in October 1987, and is the first high resolution observation of an astronomical object obtained with normal incidence multilayer optics techniques. We find that photometric data taken from this observation, applied to a simple, semi-empirical model of supersonic solar wind flow, are consistent with the idea that polar plumes are a source of the solar wind. However, we are not able to uniquely trace high speed streams to polar plumes. The temperatures that we observed are typically similar to 1500 000 K for both the plumes and the interplume regions, with the plume temperatures slightly higher than those of the surrounding atmosphere. Typical electron densities of the plume and interplume regions,respectively, are 5 x 10(9) cm(-3) and 1 x 10(8) cm(-3) at the limb of the Sun. C1 STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305. STANFORD UNIV,CTR SPACE SCI & ASTROPHYS,STANFORD,CA 94305. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NASA,MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812. RP WALKER, ABC (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. NR 26 TC 44 Z9 45 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 1993 VL 148 IS 2 BP 239 EP 252 DI 10.1007/BF00645089 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML851 UT WOS:A1993ML85100006 ER PT J AU AMBASTHA, A HAGYARD, MJ WEST, EA AF AMBASTHA, A HAGYARD, MJ WEST, EA TI EVOLUTIONARY AND FLARE-ASSOCIATED MAGNETIC SHEAR VARIATIONS OBSERVED IN A COMPLEX, FLARE-PRODUCTIVE ACTIVE-REGION SO SOLAR PHYSICS LA English DT Article ID VECTOR MAGNETOGRAMS; FIELDS; FLUX AB Evolution of nonpotential structures in a complex, flare-productive active region NOAA AR 6555 has been studied during the period March 23-26, 1991, using a quantitative description of the degree of magnetic shear at both local and regional scares. Distinct shear evolution in four subareas of AR 6555 is inferred from daily variation of their shear indices. Subareas which showed significant evolution in their overall magnetic structure are found to be most active. Ha Bare ribbons mostly formed bordering, and not within, areas of large shear and expanded over areas of lower shear. Magnetic shear changes are also detected during several flares, including a major X4.7/4B hare. Out of the 14 events for which temporally contiguous magnetograms were available, a decrease, or dip, in area-averaged shear index around flare onset time followed by an increase was observed in eight cases. There were two events with increase, three events with continuous decrease, and one event with no change in the shear index during the flare. C1 UDAIPUR SOLAR OBSERV,UDAIPUR,RAJASTHAN,INDIA. RP AMBASTHA, A (reprint author), NASA,MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,ES52,HUNTSVILLE,AL 35812, USA. OI Ambastha, Ashok/0000-0001-7592-2120 NR 26 TC 70 Z9 71 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 1993 VL 148 IS 2 BP 277 EP 299 DI 10.1007/BF00645091 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML851 UT WOS:A1993ML85100008 ER PT J AU LAU, YT AF LAU, YT TI MAGNETIC NULLS AND TOPOLOGY IN A CLASS OF SOLAR-FLARE MODELS SO SOLAR PHYSICS LA English DT Article ID 3-DIMENSIONAL KINEMATIC RECONNECTION; ELECTRIC-CURRENT SHEETS; MAGNETOHYDRODYNAMIC EQUILIBRIA; ACTIVE REGIONS; NEUTRAL LINE; RE-CONNEXION; FIELD LINES; CORONA; FLOWS AB We study the magnetic field-line topology in a class of solar flare models with four magnetic dipoles. By introducing a series of symmetry-breaking perturbations to a fully symmetric potential field model, we show that isolated magnetic nulls generally exist above the photosphere. These nuns are physically important because they determine the magnetic topology above the photosphere. In some special cases, there may be a single null above the photosphere with quasi two-dimensional properties. For such a model, a quasi null line connects the null to the photosphere. In the limit of small non-ideal effects, boundary layers and current sheets may develop along the quasi null line and the associated separatrix surfaces. Field lines can then reconect across the quasi null line, as in two-dimensional reconnection. In a more general force-free case, the field contains a pair of nulls above the photosphere, with a field line (the separator) connecting the two nulls. In the limit of small non-ideal effects, boundary layers and current sheets develop along the separator and the associated separatrix surfaces. The system exhibits three-dimensional reconnection across the separator, over which field lines exchange identity. The separatrices are related to preferable sites of energy release during solar flares. C1 NASA, GODDARD SPACE FLIGHT CTR, NATL RES COUNCIL, GREENBELT, MD 20711 USA. NR 47 TC 46 Z9 47 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 1993 VL 148 IS 2 BP 301 EP 324 DI 10.1007/BF00645092 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ML851 UT WOS:A1993ML85100009 ER PT J AU KONISHI, Y ALLEN, ST REDDY, M RODWELL, MJW SMITH, RP LIU, J AF KONISHI, Y ALLEN, ST REDDY, M RODWELL, MJW SMITH, RP LIU, J TI ALAS/GAAS SCHOTTKY-COLLECTOR RESONANT-TUNNEL-DIODES SO SOLID-STATE ELECTRONICS LA English DT Article AB The Schottky-collector resonant-tunnel-diode (SRTD) is an resonant-tunnel-diode with the normal N+ collector layer and ohmic contact replaced by direct Schottky contact to the space-charge layer, thereby eliminating the associated parasitic series resistance R(s). By scaling the Schottky collector contact to submicron dimensions, the device periphery-to-area ratio is increased, decreasing the periphery-dependent components of the parasitic resistance, and substantially increasing the device's maximum frequency of oscillation. We report measured d.c. and microwave parameters of planar SRTDs fabricated with lum-geometries in AlAs/GaAs. C1 JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109. RP KONISHI, Y (reprint author), UNIV CALIF SANTA BARBARA,ELECT & COMP ENGN,SANTA BARBARA,CA 93106, USA. NR 9 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD DEC PY 1993 VL 36 IS 12 BP 1673 EP 1676 DI 10.1016/0038-1101(93)90212-9 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ML442 UT WOS:A1993ML44200003 ER PT J AU NAGASUBRAMANIAN, G ATTIA, AI HALPERT, G PELED, E AF NAGASUBRAMANIAN, G ATTIA, AI HALPERT, G PELED, E TI COMPOSITE SOLID-ELECTROLYTE FOR LI BATTERY APPLICATIONS SO SOLID STATE IONICS LA English DT Article ID POLYMER; CONDUCTIVITY AB The electrochemical, bulk and interfacial properties of the polyethylene oxide (PEG) based composite solid electrolyte (CSE) comprising LiI, PEG, and Al2O3 have been evaluated for Li battery applications. The bulk interfacial and transport propel-ties of the CSEs seem to strongly depend on the alumina particle size. For the CSE films with 0.05 micron alumina while the bulk conductivity is around 10(-4) (mho cm(-1)) at 103 degrees C, the Li ion transport number seems to be close to unity at the same temperature. Compared to the PEO electrolyte this polymer composite electrolyte seems to exhibit robust mechanical and interfacial properties. We have studied three different films with three different alumina sizes in the range 0.01-0.3 micron. Effects of Al2O3 particle size on the electrochemical performance of polymer composite electrolyte will be discussed. With TiS2 as cathode a 10 mAh small capacity cell was charged and discharged at C/40 and C/20 rates respectively. C1 TEL AVIV UNIV,IL-69978 TEL AVIV,ISRAEL. RP NAGASUBRAMANIAN, G (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 12 TC 41 Z9 41 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD DEC PY 1993 VL 67 IS 1-2 BP 51 EP 56 DI 10.1016/0167-2738(93)90308-P PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA MR295 UT WOS:A1993MR29500008 ER PT J AU MACK, WJ SELZER, RH HODIS, HN ERICKSON, JK LIU, CR LIU, CH CRAWFORD, DW BLANKENHORN, DH AF MACK, WJ SELZER, RH HODIS, HN ERICKSON, JK LIU, CR LIU, CH CRAWFORD, DW BLANKENHORN, DH TI ONE-YEAR REDUCTION AND LONGITUDINAL ANALYSIS OF CAROTID INTIMA-MEDIA THICKNESS ASSOCIATED WITH COLESTIPOL NIACIN THERAPY SO STROKE LA English DT Article DE CARDIOVASCULAR DISEASES; CAROTID ARTERIES; CLINICAL TRIALS; LIPIDS; ULTRASONICS ID CORONARY HEART-DISEASE; ARTERY DISEASE; ATHEROSCLEROSIS; CHOLESTYRAMINE; REGRESSION; WALL; RISK; MEN AB Background and Purpose: The Cholesterol Lowering Atherosclerosis Study has reported significant reduction of coronary artery disease and of carotid arterial intima-media thickness (IMT) at 2 and 4 years with colestipol/niacin therapy. We now report on treatment effects on carotid IMT at 6 months and 1 year. Methods: One hundred eighty-eight nonsmoking men, aged 40 to 59 years, with prior coronary artery bypass graft surgery were randomized to colestipol/niacin plus diet therapy or placebo plus diet therapy. Computerized image processing of carotid ultrasound films was used to measure IMT in the right common carotid artery. Treatment group comparisons were made at 6 months and 1 year (46 and 33 subjects, respectively, with baseline and 6-month or 1-year ultrasound measures). The time course of the treatment effect on carotid IMT was estimated using the complete sample of 78 subjects with baseline and on-trial data. Results: No significant treatment group differences on carotid IMT were found at 6 months. At 1 year, the treated group showed significant reduction of carotid IMT (P=.01 between groups). The placebo group showed continuing progression of IMT during the 4-year study period (estimated progression rate, 0.018 mm/y). The treated group showed reduction of IMT during the first 3 years and a plateau during the remainder of the study. Conclusions: Reduction or carotid IMT was found with aggressive lipid-lowering therapy. Ultrasound measures of IMT offer a noninvasive and precise measure of early carotid atherosclerosis that will decrease sample size requirements, potentially decrease dropout rates, and widen the study population of antiatherosclerotic clinical trials. C1 UNIV SO CALIF,DEPT MED,ATHEROSCLEROSIS RES INST,LOS ANGELES,CA 90033. JET PROP LAB,PASADENA,CA 91109. RP MACK, WJ (reprint author), UNIV SO CALIF,DEPT PREVENT MED,1420 SAN PABLO,PMB B101,LOS ANGELES,CA 90033, USA. FU NHLBI NIH HHS [1-HL-45005] NR 22 TC 112 Z9 112 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0039-2499 J9 STROKE JI Stroke PD DEC PY 1993 VL 24 IS 12 BP 1779 EP 1783 PG 5 WC Clinical Neurology; Peripheral Vascular Disease SC Neurosciences & Neurology; Cardiovascular System & Cardiology GA MK485 UT WOS:A1993MK48500001 PM 8248954 ER PT J AU SOBIESZCZANSKISOBIESKI, J AF SOBIESZCZANSKISOBIESKI, J TI 2 ALTERNATIVE WAYS FOR SOLVING THE COORDINATION PROBLEM IN MULTILEVEL OPTIMATION SO STRUCTURAL OPTIMIZATION LA English DT Article AB The paper describes two new techniques for formulating the coupling between levels in multilevel optimization by linear decomposition, proposed as improvements over the original formulation, now several years old, that relied on explicit equality constraints which were shown by application experience as occasionally causing numerical difficulties. The two new techniques account for the coupling without using explicit equality constraints, thus avoiding the above difficulties and also reducing the computational cost of the procedure. The old and new formulations are presented in detail, illustrated by an example of a structural optimization. A generic version of the improved algorithm is also developed for applications to multidisciplinary systems not limited to structures. RP SOBIESZCZANSKISOBIESKI, J (reprint author), NASA,LANGLEY RES CTR,DIV STRUCT DYNAM,STRUCT DIRECTORATE,MS242,HAMPTON,VA 23681, USA. NR 0 TC 21 Z9 21 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0934-4373 J9 STRUCT OPTIMIZATION JI Struct. Optim. PD DEC PY 1993 VL 6 IS 4 BP 205 EP 215 DI 10.1007/BF01743377 PG 11 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics SC Computer Science; Engineering; Mechanics GA MP112 UT WOS:A1993MP11200001 ER PT J AU LONG, SR LAI, RJ HUANG, NE SPEDDING, GR AF LONG, SR LAI, RJ HUANG, NE SPEDDING, GR TI BLOCKING AND TRAPPING OF WAVES IN AN INHOMOGENEOUS FLOW SO DYNAMICS OF ATMOSPHERES AND OCEANS LA English DT Article ID DEEP-WATER; GRAVITY AB The blocking and trapping of waves and wave packets by inhomogeneous flow fields were studied in a laboratory setting. Evidence for multiple reflections and thus trapping within the current gradient zone near the blocking point are the main results obtained, and lead to the following conclusions: (1) a strong current gradient zone near the blocking point can trap wave energy, which will shift the wavenumbers into the capillary region, to match the microwave wavelength of many remote sensing instruments; (2) this mechanism provides a direct link between strong current gradient zones (bathymetric features in tidal flows, eddies, current boundaries, etc.) and the surface wave structure, which in turn allows instruments such as the Synthetic Aperture Radar (SAR) to form images of bottom features based solely on the small wave conditions; (3) an indication of direct energy transfer from the carrier waves to low-frequency waves was also observed, and resolved by wavelet analysis. The instantaneous spectra from wavelet analysis reveal that a large portion of wave energy transfers directly into the low-frequency band from the carrier waves at the trapping zone. Subharmonics may play a critical role in the energy transfer process, but details are still to be established. C1 MINERALS MANAGEMENT SERV,HERNDON,VA 22070. NASA,GODDARD SPACE FLIGHT CTR,OCEANS & ICE BRANCH,GREENBELT,MD 20771. UNIV SO CALIF,DEPT AEROSP ENGN,LOS ANGELES,CA 90089. RP LONG, SR (reprint author), NASA,GODDARD SPACE FLIGHT CTR,WALLOPS FLIGHT FACIL,OBSERVAT SCI BRANCH,CODE 972,WALLOPS ISL,VA 23337, USA. RI Spedding, Geoffrey/A-1860-2010; Long, Steven/D-7248-2012 OI Spedding, Geoffrey/0000-0003-3033-7897; NR 22 TC 16 Z9 19 U1 0 U2 3 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 NOV 30 PY 1993 VL 20 IS 1-2 BP 79 EP 106 DI 10.1016/0377-0265(93)90049-D PG 28 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA MT486 UT WOS:A1993MT48600005 ER PT J AU VATSA, VN TURKEL, E ABOLHASSANI, JS AF VATSA, VN TURKEL, E ABOLHASSANI, JS TI EXTENSION OF MULTIGRID METHODOLOGY TO SUPERSONIC/HYPERSONIC 3-D VISCOUS FLOWS SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE MULTIGRID; SUPERSONIC; HYPERSONIC; VISCOUS ID NAVIER-STOKES EQUATIONS AB A multigrid acceleration technique developed for solving the three-dimensional Navier-Stokes equations for subsonic/transonic flows has been extended to supersonic/hypersonic flows. An explicit multistage Runge-Kutta type of time-stepping scheme is used as the basic algorithm in conjunction with the multigrid scheme. Solutions have been obtained for a blunt conical frustum at Mach 6 to demonstrate the applicability of the multigrid scheme to high-speed flows. Computations have also been performed for a generic High-Speed Civil Transport configuration designed to cruise at Mach 3. These solutions demonstrate both the efficiency and accuracy of the present scheme for computing high-speed viscous flows over configurations of practical interest. C1 I CASE,TEL AVIV,ISRAEL. TEL AVIV UNIV,TEL AVIV,ISRAEL. COMP SCI CORP,HAMPTON,VA. RP VATSA, VN (reprint author), NASA,LANGLEY RES CTR,INST COMP APPLICAT SCI & ENGN,HAMPTON,VA 23665, USA. RI Turkel, Eli/F-6297-2011 OI Turkel, Eli/0000-0003-4273-0303 NR 21 TC 5 Z9 5 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD NOV 30 PY 1993 VL 17 IS 10 BP 825 EP 837 DI 10.1002/fld.1650171002 PG 13 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA MG267 UT WOS:A1993MG26700001 ER PT J AU PARRY, ML ROSENZWEIG, C AF PARRY, ML ROSENZWEIG, C TI FOOD-SUPPLY AND RISK OF HUNGER SO LANCET LA English DT Article C1 COLUMBIA UNIV,NEW YORK,NY 10027. GODDARD INST SPACE STUDIES,NEW YORK,NY 10025. RP PARRY, ML (reprint author), UNIV OXFORD,ENVIRONM CHANGE UNIT,1A MANSFIELD RD,OXFORD OX1 3TB,ENGLAND. NR 5 TC 22 Z9 23 U1 0 U2 2 PU LANCET LTD PI LONDON PA 42 BEDFORD SQUARE, LONDON, ENGLAND WC1B 3SL SN 0140-6736 J9 LANCET JI Lancet PD NOV 27 PY 1993 VL 342 IS 8883 BP 1345 EP 1347 DI 10.1016/0140-6736(93)92251-N PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA MJ039 UT WOS:A1993MJ03900014 PM 7901640 ER PT J AU BANIN, A BENSHLOMO, T MARGULIES, L BLAKE, DF MANCINELLI, RL GEHRING, AU AF BANIN, A BENSHLOMO, T MARGULIES, L BLAKE, DF MANCINELLI, RL GEHRING, AU TI THE NANOPHASE IRON MINERAL(S) IN MARS SOIL SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Review ID VIKING BIOLOGY EXPERIMENTS; FE(II)FE(III) HYDROXY-CARBONATE; GREEN RUST; MAGNETIC-PROPERTIES; BASALTIC GLASS; THERMAL-TREATMENT; MARTIAN SURFACE; FE(II) CHLORIDE; GAMMA-FEOOH; LEPIDOCROCITE AB A series of surface-modified clays containing nanophase (np) iron oxideloxyhydroxides of extremely small particle sizes, with total iron contents as high as found in Mars soil, were prepared by iron deposition on the clay surface from ferrous chloride solution. Comprehensive studies of the iron mineralogy in these ''Mars-soil analogs'' were conducted using chemical extractions, solubility analyses, pH and redox, x ray and electron diffractometry, electron microscopic imaging, specific surface area and particle size determinations, differential thermal analyses, magnetic properties characterization, spectral reflectance, and Viking biology simulation experiments. The clay matrix and the procedure used for synthesis produced nanophase iron oxides containing a certain proportion of divalent iron, which slowly converts to more stable, fully oxidized iron minerals. The clay acted as an effective matrix, both chemically and sterically, preventing the major part of the synthesized iron oxides from ripening, i.e., growing and developing larger crystals. The precipitated iron oxides appear as isodiametric or slightly elongated particles in the size range 1-10 nm, having large specific surface area. The noncrystalline nature of the iron compounds precipitated on the surface of the clay was verified by their complete extractability in oxalate. Lepidocrocite (gamma-FeOOH) was detected by selected area electron diffraction. It is formed from a double iron Fe(II)/Fe(III) hydroxy mineral such as ''green rust,'' or ferrosic hydroxide. Magnetic measurements suggested that lepidocrocite converted to the more stable maghemite (gamma-Fe2O3) by mild heat treatment and then to nanophase hematite alpha-Fe2O3) by extensive heat treatment. After mild heating, the iron-enriched clay became slightly magnetic, to the extent that it adheres to a hand-held magnet, as was observed with Mars soil. The chemical reactivity of the iron-enriched clays strongly resembles, and offers a plausible mechanism for, the somewhat puzzling observations of the Viking biology experiments. Their unique chemical reactivities are attributed to the combined catalytic effects of the iron oxide/oxyhydroxide and silicate phase surfaces. The reflectance spectrum of the clay-iron preparations in the visible range is generally similar to the reflectance curves of bright regions on Mars. This strengthens the evidence for the predominance of nanophase iron oxides/oxyhydroxides in Mars soil. The mode of formation of these nanophase iron oxides on Mars is still unknown. It is puzzling that despite the long period of time since aqueous weathering took place on Mars, they have not developed from their transitory stage to well-crystallized end-members. The possibility is suggested that these phases represent a continuously on-going, extremely slow weathering process. C1 NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035. UNIV CALIF BERKELEY,DEPT SOIL SCI,BERKELEY,CA 94720. RP BANIN, A (reprint author), HEBREW UNIV JERUSALEM,DEPT SOIL & WATER SCI,POB 12,IL-76100 REHOVOT,ISRAEL. RI Mancinelli, Rocco/L-8971-2016 NR 112 TC 44 Z9 44 U1 5 U2 22 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 1993 VL 98 IS E11 BP 20831 EP 20853 DI 10.1029/93JE02500 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA MJ713 UT WOS:A1993MJ71300003 ER PT J AU SMITH, DE LERCH, FJ NEREM, RS ZUBER, MT PATEL, GB FRICKE, SK LEMOINE, FG AF SMITH, DE LERCH, FJ NEREM, RS ZUBER, MT PATEL, GB FRICKE, SK LEMOINE, FG TI AN IMPROVED GRAVITY MODEL FOR MARS - GODDARD MARS-MODEL-1 SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID DEIMOS ASTROMETRIC OBSERVATIONS; GRAVITATIONAL MODEL; TERRESTRIAL PLANETS; LITHOSPHERIC STRESS; TRACKING; HARMONICS; TECTONICS; MARINER-9; PHOBOS; VIKING AB Doppler tracking data of three orbiting spacecraft have been reanalyzed to develop a new gravitational held model for the planet Mars, Goddard Mars Model 1 (GMM-1). This model employs nearly all available data, consisting of approximately 1100 days of S band tracking data collected by NASA's Deep Space Network from the Mariner 9 and Viking 1 and Viking 2 spacecraft, in seven different orbits, between 1971 and 1979. GMM-1 is complete to spherical harmonic degree and order 50, which corresponds to a half-wavelength spatial resolution of 700-300 km where the data permit. GMM-1 represents satellite orbits with considerably better accuracy than previous Mars gravity models and shows greater resolution of identifiable geological structures. The notable improvement in GMM-1 over previous models is a consequence of several factors: improved computational capabilities, the use of optimum weighting and least squares collocation solution techniques which stabilized the behavior of the solution at high degree and order, and the use of longer satellite arcs than employed in previous solutions that were made possible by improved force and measurement models. The inclusion of X band tracking data from the 379-km altitude, near-polar orbiting Mars Observer spacecraft should provide a significant improvement over GMM-1, particularly at high latitudes where current data poorly resolve the gravitational signature of the planet. C1 RMS TECHNOL INC,LANDOVER,MD 20785. HUGHES STX CORP,LANHAM,MD 20706. JOHNS HOPKINS UNIV,DEPT EARTH & PLANETARY SCI,BALTIMORE,MD 21218. RP SMITH, DE (reprint author), NASA,GODDARD SPACE FLIGHT CTR,TERR PHYS LAB,GREENBELT,MD 20771, USA. RI Lemoine, Frank/D-1215-2013 NR 57 TC 71 Z9 76 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-PLANET JI J. Geophys. Res.-Planets PD NOV 25 PY 1993 VL 98 IS E11 BP 20871 EP 20889 DI 10.1029/93JE01839 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA MJ713 UT WOS:A1993MJ71300005 ER PT J AU BLUTH, GJS SCHNETZLER, CC KRUEGER, AJ WALTER, LS AF BLUTH, GJS SCHNETZLER, CC KRUEGER, AJ WALTER, LS TI THE CONTRIBUTION OF EXPLOSIVE VOLCANISM TO GLOBAL ATMOSPHERIC SULFUR-DIOXIDE CONCENTRATIONS SO NATURE LA English DT Article ID SULFUR-DIOXIDE; ICE-SHEET; ERUPTIONS; CLOUDS; SO2 AB SULPHUR dioxide from volcanic eruptions may have a significant effect on the Earth's climate and atmospheric chemistry, and it is therefore important to quantify outgassing rates for all types of volcanic activity. Non-explosive volcanoes (for example, Mount Etna) outgas at relatively constant rates, providing an annual flux of about 9 million tons (Mt) SO2 (ref. 1). By contrast, the outgassing from volcanoes prone to explosive eruptions (such as Mount Pinatubo) is sporadic and much more difficult to quantify. The total annual volcanic SO2 flux is therefore poorly constrained, with ground-based estimates1-8 ranging from 1.5 to 50 Mt-up to one-quarter of the estimated current anthropogenic contribution. The Total Ozone Mapping Spectrometer aboard the NASA satellite Nimbus 7 recorded SO2 emissions from explosive eruptions from November 1978 to May 1993. We use these data to show that the annual flux from explosive volcanism is of the order of 4 Mt SO2, less than half of the non-explosive output. Thus it seems that the total volcanic emission of SO2 to the Earth's atmosphere is about 13 Mt yr-1, which is only 5-10% of the current anthropogenic flux. C1 UNIV MARYLAND,DEPT GEOG,COLL PK,MD 20742. NASA,GODDARD SPACE FLIGHT CTR,EARTH SCI DIRECTORATE,GREENBELT,MD 20771. RP BLUTH, GJS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,CODE 921,GREENBELT,MD 20771, USA. NR 18 TC 157 Z9 158 U1 2 U2 17 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD NOV 25 PY 1993 VL 366 IS 6453 BP 327 EP 329 DI 10.1038/366327a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MJ705 UT WOS:A1993MJ70500043 ER PT J AU DONNELLAN, A HAGER, BH KING, RW AF DONNELLAN, A HAGER, BH KING, RW TI DISCREPANCY BETWEEN GEOLOGICAL AND GEODETIC DEFORMATION RATES IN THE VENTURA BASIN SO NATURE LA English DT Article ID WESTERN TRANSVERSE RANGES; SOUTHERN-CALIFORNIA; EARTHQUAKES; KINEMATICS; FAULT AB SPACE geodesy provides a new tool for measuring neotectonic deformation which, when combined with geological and geophysical observations and models, can be used to infer rates and styles of deformation. In the Ventura basin region of southern California, the geodetically measured convergence rates of approximately 7-10 mm yr-1 (ref. 1) are significantly lower than the 20-25 mm yr-1 estimated from geological data2,3 . Here we investigate the possible implications of this discrepancy. It might be, for example, that temporal variations cause the short- and long-term convergence rates to differ. But if this were the case we would expect to observe the long-term rate by extending the geodetic measurements over a broader region, yet only 11+/-3 mm yr-1 of regional convergence is observed4. Our preferred explanation of the discrepancy is that the geological models require revision, and to this end we present two deformation models that satisfy both the geological and geodetic constraints. Our modelling suggests that the faults bounding the basin are locked at the surface, but are slipping at depths below approximately 2-5 km. C1 MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139. RP DONNELLAN, A (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 19 TC 46 Z9 46 U1 0 U2 5 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD NOV 25 PY 1993 VL 366 IS 6453 BP 333 EP 336 DI 10.1038/366333a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MJ705 UT WOS:A1993MJ70500045 ER PT J AU HANER, DA MENZIES, RT AF HANER, DA MENZIES, RT TI INTEGRATING SPHERE DEPOLARIZATION AT 10 MU-M FOR A NON-LAMBERTIAN WALL SURFACE - APPLICATION TO LIDAR CALIBRATION SO APPLIED OPTICS LA English DT Article ID HARD TARGET CALIBRATION AB The relative Stokes vectors at the detector exit port of a sandblasted and gold-plated integrating sphere are determined for four different polarizations incident on five unique surfaces. The results indicate in all cases that the integrating sphere is a depolarizer. These results validate assumptions used in hard-target calibration methodology for infrared lidars. C1 CALIF STATE POLYTECH UNIV POMONA, DEPT CHEM, POMONA, CA 91768 USA. RP HANER, DA (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 10 TC 5 Z9 5 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 20 PY 1993 VL 32 IS 33 BP 6804 EP 6807 PG 4 WC Optics SC Optics GA MH575 UT WOS:A1993MH57500035 PM 20856533 ER PT J AU EGAN, WG ISRAEL, S SIDRAN, M HINDMAN, EE JOHNSON, WR WHITEHEAD, VS AF EGAN, WG ISRAEL, S SIDRAN, M HINDMAN, EE JOHNSON, WR WHITEHEAD, VS TI OPTICAL-PROPERTIES OF CONTINENTAL HAZE AND CUMULUS AND OROGRAPHIC CLOUDS BASED ON SPACE-SHUTTLE POLARIMETRIC OBSERVATIONS SO APPLIED OPTICS LA English DT Article DE OPTICAL REMOTE SENSING; POLARIZATION; HAZE; CLOUDS ID PLANETARY ATMOSPHERES; POLARIZATION; LIGHT; SCATTERING; RADIATION AB Digitized Space Shuttle imagery in the red, green, and blue spectral regions (0.600, 0.540, and 0.435 mu m, respectively) is used to characterize the mean radius and the index of refraction of droplets in cumulus and orographic clouds. The clouds are shown to consist concurrently of submicrometer and supermicrometer droplets, with the percent polarization indicative of the dominant sizes. Cloud development from haze as well as inhomogeneities in the cloud decks can be traced remotely. The absorption properties of clouds can also be determined remotely. An optical depth of continental haze in the same three spectral regions as the clouds is computed from the polarimetric and photometric contributions. Both Mie and Rayleigh scattering are included in the model. C1 POLYTECH INST NEW YORK, BROOKLYN, NY 11201 USA. LOCKHEED ENGN & SCI CO, HOUSTON, TX 77258 USA. CUNY, BARUCH COLL, NEW YORK, NY 10010 USA. CUNY, CITY COLL, NEW YORK, NY 10031 USA. NASA, JOHNSON SPACE CTR, HOUSTON, TX 77258 USA. NR 30 TC 6 Z9 6 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 20 PY 1993 VL 32 IS 33 BP 6841 EP 6852 PG 12 WC Optics SC Optics GA MH575 UT WOS:A1993MH57500040 PM 20856538 ER PT J AU BARING, MG AF BARING, MG TI GAMMA-GAMMA ATTENUATION AND RELATIVISTIC BEAMING IN GAMMA-RAY BURSTS SO ASTROPHYSICAL JOURNAL LA English DT Article DE GAMMA-RAYS, BURSTS; RADIATION MECHANISMS, MISCELLANEOUS; RELATIVITY ID STRONG MAGNETIC-FIELDS; COMPTON-SCATTERING; PAIR PRODUCTION; SPECTRA; FIREBALLS; PHOTON; CASCADES; PLASMAS; MODELS AB The observation by the BATSE experiment on board the Compton Gamma-Ray Observatory (CGRO) that the gamma-ray burst population is isotropic but inhomogeneous has dramatically bolstered the premise that most bursts are cosmological. At the same time, BATSE has also observed definite spectral breaks (Schaefer et al (1992) between 400 keV and 2 MeV in some bursts, which in three cases have been corroborated by data from EGRET. The presence of these breaks in these sources suggests attenuation by the pair production mechanism gammagamma --> e+e-, which can absorb gamma rays, though it is suppressed when the radiation is highly beamed. In this paper, quantitative constraints that pair production places on radiation collimation in individual sources, due to the presence or absence of breaks in spectra, are presented. Cosmological bursts have extremely relativistic beaming, though the bulk Lorentz factors of their emission regions are reduced markedly for steep source spectra. Such beaming will blueshift the breaks to higher energies, indicating that those CGRO bursts displaying MeV spectral breaks may not be cosmological, or perhaps that their breaks are generated by mechanisms that dominate gamma-gamma attenuation at MeV energies. Alternative mechanisms for break production are discussed. RP BARING, MG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 31 TC 32 Z9 32 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 1993 VL 418 IS 1 BP 391 EP 394 DI 10.1086/173398 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MF864 UT WOS:A1993MF86400035 ER PT J AU PALLA, F STAHLER, SW AF PALLA, F STAHLER, SW TI THE PRE-MAIN-SEQUENCE EVOLUTION OF INTERMEDIATE-MASS STARS SO ASTROPHYSICAL JOURNAL LA English DT Article DE STARS, EVOLUTION; STARS, INTERIORS; STARS, PRE-MAIN-SEQUENCE ID THERMONUCLEAR REACTION-RATES; HERBIG AE-TYPE; PROTOSTARS; BIRTHLINE; DEUTERIUM AB We calculate numerically the structure and evolution of pre-main-sequence stars with masses from 1 to 6 M.. These stars are assumed to originate from protostars accreting within molecular clouds. For masses from 2 to 4 M., the stellar luminosity first increases markedly during a protracted epoch of nonhomologous contraction and thermal relaxation. Deuterium burns in a subsurface shell throughout this period. More massive objects are thermally relaxed from the start; they contract homologously, with fully radiative interiors. Stars with masses greater then 8 M. have no pre-main-sequence phase, since they are already burning hydrogen by the time protostellar accretion has ended. We summarize our results by presenting a new set of evolutionary tracks in the H-R diagram. Our calculations imply that Herbig Ae and Be stars are substantially younger than previously believed. The upper boundary to their distribution in the H-R diagram is well matched by our theoretical birthline. The presence in these stars of emission lines and strong winds is not linked to an outer convection zone, since our models show that such convection always vanishes with rising effective temperature. Finally, while residual accretion from circumstellar disks may be occurring, we argue that the associated mass transfer rates are not high enough to account for the stars' observed infrared excesses. C1 UNIV CALIF BERKELEY, DEPT ASTRON, BERKELEY, CA 94720 USA. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RP PALLA, F (reprint author), OSSERV ASTROFIS ARCETRI, LARGO E FERMI 5, I-50125 FLORENCE, ITALY. OI palla, francesco/0000-0002-3321-0456 NR 49 TC 490 Z9 492 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 1993 VL 418 IS 1 BP 414 EP + DI 10.1086/173402 PN 1 PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MF864 UT WOS:A1993MF86400039 ER PT J AU KNACKE, RF FAJARDOACOSTA, SB TELESCO, CM HACKWELL, JA LYNCH, DK RUSSELL, RW AF KNACKE, RF FAJARDOACOSTA, SB TELESCO, CM HACKWELL, JA LYNCH, DK RUSSELL, RW TI THE SILICATES IN THE DISK OF BETA-PICTORIS SO ASTROPHYSICAL JOURNAL LA English DT Article DE CIRCUMSTELLAR MATTER; DUST, EXTINCTION; INFRARED, STARS; STARS, INDIVIDUAL (BETA-PICTORIS) ID T-TAURI STARS; CIRCUMSTELLAR DISK; OPTICAL-PROPERTIES; DUST; RESOLUTION; SPECTROPHOTOMETRY; GRAPHITE; MICRONS; SPECTRA; GRAINS AB We have obtained intermediate-resolution (R almost-equal-to 50) infrared (2.6-13.5 mum) spectra Of the particles in the circumstellar disk of beta Pic. The silicate dust feature near 10 mum is broader and contains more structure than interstellar and most circumstellar emission features. The silicate feature in beta Pic is remarkably similar to those in comets Halley, Bradfield 1987s, and Levy 1990 XX which have emission features characteristic of crystalline silicates. This result supports the inference based on IRAS results that cometary bodies resupply the grains in the beta Pic disk. Detailed models of the dust disk and grains are used to derive plausible disk temperature and density gradients. We discuss implications of these results on the history and state of dust in disks and the solar system. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. AEROSP CORP,LOS ANGELES,CA 90009. UNIV HAWAII,INFRARED TELESCOPE FACIL,HONOLULU,HI 96822. SUNY STONY BROOK,DEPT EARTH & SPACE SCI,STONY BROOK,NY 11794. RP KNACKE, RF (reprint author), PENN STATE UNIV,DIV SCI,STN RD,ERIE,PA 16563, USA. NR 38 TC 166 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 20 PY 1993 VL 418 IS 1 BP 440 EP 450 DI 10.1086/173405 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MF864 UT WOS:A1993MF86400042 ER PT J AU BURROWS, A FRYXELL, BA AF BURROWS, A FRYXELL, BA TI A CONVECTIVE TRIGGER FOR SUPERNOVA EXPLOSIONS SO ASTROPHYSICAL JOURNAL LA English DT Article DE HYDRODYNAMICS; SUPERNOVAE, GENERAL; SHOCK WAVES ID 1987A; NEUTRINOS AB The shock wave that stalls within approximately 10 ms of its creation during the collapse and bounce of the core of a massive star leaves behind it unstable lepton and entropy profiles that can drive a violent Rayleigh-Taylor-like overturn. Coupling two-dimensional hydrodynamics with independent one-dimensional neutrino transport in 100 angular bins, we demonstrate the possible existence of a convective boost in the neutrino luminosities that can ignite a supernova explosion. While the shock-imposed negative entropy gradient drives the early convection, neutrino heat transfer can smooth it within 15 ms. However, the negative lepton gradient, generically created at shock break-out, is not smoothed and is reponsible for vigorous mantle overturn just interior to the early entropy spike. Within 30 ms of shock decay, a model that in two-dimensions with no transport does not explode and in one dimension with transport does not explode, does explode in two dimensions with transport. The instability dredges up heat, feeds the neutrinospheres, and accelerates the rate of energy and lepton loss in the mantle by up to a factor of 2. C1 UNIV ARIZONA,DEPT ASTRON,TUCSON,AZ 85721. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP BURROWS, A (reprint author), UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721, USA. NR 33 TC 52 Z9 52 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 1993 VL 418 IS 1 BP L33 EP L35 DI 10.1086/187109 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MF865 UT WOS:A1993MF86500009 ER PT J AU DUPREE, AK BRICKHOUSE, NS DOSCHEK, GA GREEN, JC RAYMOND, JC AF DUPREE, AK BRICKHOUSE, NS DOSCHEK, GA GREEN, JC RAYMOND, JC TI THE EXTREME-ULTRAVIOLET SPECTRUM OF ALPHA AURIGAE (CAPELLA) SO ASTROPHYSICAL JOURNAL LA English DT Article DE STARS, CHROMOSPHERES; STARS, GIANT; STARS, MASS LOSS; STARS, INDIVIDUAL (ALPHA-AURIGAE) ID CORONA; IRON; EMISSION; LINES; STARS; FE AB Extreme ultraviolet spectra (lambdalambda 70-740) of the bright spectroscopic binary system, Capella (Alpha Aurigae) obtained with the Extreme Ultraviolet Explorer satellite (EUVE), show a rich emission spectrum-dominated by iron emission lines: Fe XV-XXIV. The emission measure for the system reveals a continuous distribution of plasma temperatures between 10(5) and 10(7.8) K, with a clear minimum near 10' K and a local maximum at 6 x 10(6) K. Electron density diagnostics based on Fe XXI indicate N(e) almost-equal-to 4 x 10(11)-10(13) cm-3 at T(e) = 10(7) K. C1 UNIV COLORADO, CASA, BOULDER, CO 80304 USA. HARVARD SMITHSONIAN CTR ASTROPHYS, CAMBRIDGE, MA 02138 USA. USN, RES LAB, WASHINGTON, DC 20375 USA. RP NASA, WASHINGTON, DC 20546 USA. NR 40 TC 117 Z9 117 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 NOV 20 PY 1993 VL 418 IS 1 BP L41 EP L44 DI 10.1086/187111 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MF865 UT WOS:A1993MF86500011 ER PT J AU GEHRELS, N WILLIAMS, ED AF GEHRELS, N WILLIAMS, ED TI TEMPERATURES OF ENHANCED STABILITY IN HOT THIN PLASMAS SO ASTROPHYSICAL JOURNAL LA English DT Article DE PLASMAS; INSTABILITIES; X-RAY, STARS ID X-RAY-EMISSION; CAPELLA; CORONA; SPECTRUM; EINSTEIN; STARS AB We show that structure in the cooling curve for thin 10(6) K cosmic plasmas can affect thermal stability. There is general instability in the 10(5)-10(7) K range caused by the decrease in line cooling as increasing temperature ionizes the gas. The cooling curve is not monotonic, however, but has two local maxima with small regions of positive slope near 10(6) and 6 x 10(6) K. We point out that these are temperature ranges of enhanced stability. This may explain the concentration of late-type stellar coronal temperatures near 6 x 10(6) K. Such a correlation was pointed out by Leman et al. for three RS CVn systems. We find that it holds beautifully for a large sample of RS CVn's. The correlation can be tested by coronal spectral measurements currently being made by the Extreme Ultraviolet Explorer (EUVE) and the Advanced Satellite for Cosmology and Astrophysics (ASCA) missions. Coordinated observations of stellar coronae with these missions are strongly encouraged. C1 UNIV MARYLAND, DEPT PHYS, COLL PK, MD 20742 USA. RP NASA, GODDARD SPACE FLIGHT CTR, CODE 661, GREENBELT, MD 20771 USA. RI Gehrels, Neil/D-2971-2012 NR 33 TC 34 Z9 34 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 NOV 20 PY 1993 VL 418 IS 1 BP L25 EP + DI 10.1086/187107 PN 2 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MF865 UT WOS:A1993MF86500007 ER PT J AU SELESNICK, RS CUMMINGS, AC CUMMINGS, JR LESKE, RA MEWALDT, RA STONE, EC VONROSENVINGE, TT AF SELESNICK, RS CUMMINGS, AC CUMMINGS, JR LESKE, RA MEWALDT, RA STONE, EC VONROSENVINGE, TT TI CORONAL ABUNDANCES OF NEON AND MAGNESIUM ISOTOPES FROM SOLAR ENERGETIC PARTICLES SO ASTROPHYSICAL JOURNAL LA English DT Article ID NOBLE-GASES; NUCLEI AB The relative abundances of 22 to 70 MeV nucleon-1 Ne and Mg isotopes from two large flare-associated solar energetic particle (SEP) events in 1992 October and November, are determined from data taken by the Mass Spectrometer Telescope on the polar-orbiting SAMPEX satellite. After converting the measured abundances to coronal values, the average Ne-22/Ne-20 ratio is 0.076 +/- 0.008, consistent with the solar wind value of 0.073 but significantly less than that of previous SEP measurements, in which the abundance of Ne-22 was substantially enhanced. The average Mg-26/Mg-24 ratio is 0.152 +/- 0.012, consistent with both previous SEP and other solar system measurements. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP SELESNICK, RS (reprint author), CALTECH,PASADENA,CA 91125, USA. NR 30 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 1993 VL 418 IS 1 BP L45 EP L48 DI 10.1086/187112 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MF865 UT WOS:A1993MF86500012 ER PT J AU RINSLAND, CP GUNSON, MR ABRAMS, MC LOWES, LL ZANDER, R MAHIEU, E AF RINSLAND, CP GUNSON, MR ABRAMS, MC LOWES, LL ZANDER, R MAHIEU, E TI ATMOS ATLAS-1 MEASUREMENTS OF SULFUR-HEXAFLUORIDE (SF6) IN THE LOWER STRATOSPHERE AND UPPER TROPOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PARAMETERS; COF2 AB Vertical profiles of sulfur hexafluoride (SF6) in the lower stratosphere and upper troposphere have been retrieved from 0.01-cm-1 resolution infrared solar occultation spectra recorded by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer during the ATLAS (Atmospheric Laboratory for Applications and Science) 1 shuttle mission of March 24 to April 2, 1992. Based on measurements of the unresolved absorption by the SF6 nu3 band Q branch at 947.9 cm-1, average SF6 volume mixing ratios and 1-sigma uncertainties of 3.20 +/- 0.54 parts per trillion by volume (pptv; 10(-12) ppv) at 200 mbar (approximately 11.8 km) declining to 2.86 +/- 0.29 pptv at 100 mbar (approximately 16.2 km) and 1.95 +/- 0.50 pptv at 30 mbar (approximately 23.9 km) have been retrieved. The profiles show no obvious dependence with latitude over the range of the measurements (eight occultations spanning 28-degrees-S to 54-degrees-S). Assuming an exponential growth model and applying a correction for the interhemispheric concentration difference, an average SF6 rate of increase of 8.7 +/- 2.2% per year, 2 sigma, between 12 and 18 km has been derived by fitting the present measurements, ATMOS measurements from the April-May 1985 Spacelab 3 mission, and balloon-borne IR measurements obtained in March 1981 and June 1988. C1 JET PROP LAB, PASADENA, CA 91109 USA. UNIV LIEGE, INST ASTROPHYS, B-4000 LIEGE, BELGIUM. RP RINSLAND, CP (reprint author), NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, MAIL CODE 401A, HAMPTON, VA 23681 USA. NR 13 TC 19 Z9 19 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 NOV 20 PY 1993 VL 98 IS D11 BP 20491 EP 20494 DI 10.1029/93JD02258 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MJ298 UT WOS:A1993MJ29800013 ER PT J AU PICKETT, HM PETERSON, DB AF PICKETT, HM PETERSON, DB TI STRATOSPHERIC OH MEASUREMENTS WITH A FAR-INFRARED LIMB OBSERVING SPECTROMETER SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HO2; SPECTROSCOPY; MILLIMETER AB The Far-Infrared Limb Observing Spectrometer (FILOS) is an instrument designed to measure the hydroxyl radical (OH) and other chemical species in the upper atmosphere using limb emission in the far-infrared region of the spectrum. FILOS uses three Fabry-Perot etalons in series to obtain high spectral resolution near 101 cm-1 and 118 cm-1. The instrument concept, calibration, and atmospheric measurements are discussed. RP PICKETT, HM (reprint author), JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 15 TC 14 Z9 14 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 NOV 20 PY 1993 VL 98 IS D11 BP 20507 EP 20515 DI 10.1029/93JD02183 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MJ298 UT WOS:A1993MJ29800015 ER PT J AU STEWART, RW AF STEWART, RW TI MULTIPLE STEADY-STATES IN ATMOSPHERIC CHEMISTRY SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SYSTEMS; MODEL AB The equations describing the distributions and concentrations of trace species are nonlinear and may thus possess more than one solution. Several authors have suggested that the steady-state equations describing tropospheric and stratopsheric chemistry may have multiple solutions, but the existence of such solutions has not been completely demonstrated. This paper develops methods for searching for multiple physical solutions to chemical continuity equations and applies these to subsets of equations describing tropospheric chemistry. The calculations are carried out with a box model and use two basic strategies. The first strategy is a ''search'' method. This involves fixing model parameters at specified values, choosing a wide range of initial guesses at a solution, and using a Newton-Raphson technique to determine if different initial points converge to different solutions. The second strategy involves a set of techniques known as homotopy methods. These do not require an initial guess, are globally convergent, and are guaranteed, in principle, to find all solutions of the continuity equations. The first method is efficient but essentially ''hit or miss'' in the sense that it cannot guarantee that all solutions which may exist will be found. The second method is computationally burdensome but can, in principle, determine all the solutions of a photochemical system. Multiple solutions have been found for models that contain a basic complement of photochemical reactions involving O(x), HO(x), NO(x), and CH4. In the present calculations, transitions occur between stable branches of a multiple solution set as a control parameter is varied. These transitions are manifestations of hysteresis phenomena in the photochemical system and may be triggered by increasing the NO flux or decreasing the CH4 flux from current mean tropospheric levels. RP STEWART, RW (reprint author), NASA, GODDARD SPACE FLIGHT CTR, MAIL CODE 916, GREENBELT, MD 20771 USA. NR 22 TC 38 Z9 38 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD NOV 20 PY 1993 VL 98 IS D11 BP 20601 EP 20611 DI 10.1029/93JD02408 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MJ298 UT WOS:A1993MJ29800023 ER PT J AU KENT, GS WINKER, DM OSBORN, MT SKEENS, KM AF KENT, GS WINKER, DM OSBORN, MT SKEENS, KM TI A MODEL FOR THE SEPARATION OF CLOUD AND AEROSOL IN SAGE-II OCCULTATION DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC AEROSOL; CIRRUS CLOUDS; TROPOSPHERIC AEROSOL; SIZE DISTRIBUTION; EXTINCTION; VALIDATION; INVERSION AB The Stratospheric Aerosol and Gas Experiment (SAGE) II satellite experiment measures the extinction due to aerosols and thin cloud, at wavelengths of 0.525 and 1,02 mum, down to an altitude of 6 km. The wavelength dependence of the extinction due to aerosols differs from that of the extinction due to cloud and is used as the basis of a model for separating these two components. The model is presented and its validation using airborne lidar data, obtained coincident with SAGE II observations, is described. This comparison shows that smaller SAGE II cloud extinction values correspond to the presence of subvisible cirrus cloud in the lidar record. Examples of aerosol and cloud data products obtained using this model to interpret SAGE II upper tropospheric and lower stratospheric data are also shown. C1 NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23665 USA. SCI APPLICAT INT CORP, HAMPTON, VA 23666 USA. RP KENT, GS (reprint author), SCI & TECHNOL CORP, 101 RES DR, HAMPTON, VA 23666 USA. NR 23 TC 75 Z9 75 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 1993 VL 98 IS D11 BP 20725 EP 20735 DI 10.1029/93JD00340 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MJ298 UT WOS:A1993MJ29800033 ER PT J AU GUPTA, SK STAYLOR, WF DARNELL, WL WILBER, AC RITCHEY, NA AF GUPTA, SK STAYLOR, WF DARNELL, WL WILBER, AC RITCHEY, NA TI SEASONAL-VARIATION OF SURFACE AND ATMOSPHERIC CLOUD RADIATIVE FORCING OVER THE GLOBE DERIVED FROM SATELLITE DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; BUDGET EXPERIMENT; LONGWAVE; CLIMATE; ISCCP; VARIABILITY; ABSORPTION; PRODUCTS; BALANCE; PROJECT AB Global distributions of surface and atmospheric cloud radiative forcing parameters have been derived using parameterized radiation models with satellite meteorological data from the International Satellite Cloud Climatology Project, and directly measured top-of-atmosphere radiative fluxes from the Earth Radiation Budget Experiment. Specifically, shortwave, longwave, and total cloud forcing at the surface, and column-averaged values of longwave cloud forcing of the atmosphere were derived for the midseasonal months of April, July, and October 1985 and January 1986, covering a complete annual cycle. Seasonal variability is illustrated by comparing the results for July 1985 and January 1986, which represent the seasonal extremes. Surface shortwave cloud forcing is always negative, representing a cooling of the surface, with strongest cooling (-120 to -180 W m-2) occurring over midlatitude storm tracks of the summer hemisphere. Surface longwave cloud forcing is always positive, representing a warming of the surface, with strongest warming (60 to 75 W m-2) occurring over storm tracks of the winter hemisphere. Zonal averages show the entire summer hemisphere dominated by shortwave cooling, the middle and high latitudes of the winter hemisphere dominated by longwave warming, and a broad zone of transition in between. The globally averaged total cloud forcing amounts to a cooling throughout the year, ranging from a low of about -12 W m-2 for July 1985 to a high of about -25 W m -2 for January 1986. The longwave cloud forcing of the atmosphere shows a strong warming over deep convective regions in the tropics and a moderate cooling outside the tropics, amounting to a weak cooling (-2 to -5 W m-2)in the global average. Comparisons of the results with general circulation model simulations show broad qualitative agreement regarding the locations of prominent warming and cooling regions. Quantitative comparisons, on the other hand, show significant differences between the magnitudes of warming and cooling in these regions. Most of the larger differences can be attributed to known deficiences of the general circulation model simulations. Comparisons with satellite-derived results of other investigators show much better agreement. C1 NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23681 USA. RP GUPTA, SK (reprint author), LOCKHEED ENGN & SCI CO, LANGLEY PROGRAM OFF, 144 RES DR, HAMPTON, VA 23666 USA. RI wilber, anne/F-6270-2011 NR 51 TC 32 Z9 32 U1 1 U2 6 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 1993 VL 98 IS D11 BP 20761 EP 20778 DI 10.1029/93JD01533 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA MJ298 UT WOS:A1993MJ29800035 ER PT J AU PULKKINEN, TI BAKER, DN OWEN, CJ GOSLING, JT MURPHY, N AF PULKKINEN, TI BAKER, DN OWEN, CJ GOSLING, JT MURPHY, N TI THIN CURRENT SHEETS IN THE DEEP GEOMAGNETIC TAIL SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SUBSTORM GROWTH-PHASE; DISTANT MAGNETOTAIL; PLASMA SHEET; ISEE-C; AVERAGE AB The ISEE-3 magnetic field and plasma electron data from Jan - March 1983 have been searched to study thin current sheets in the deep tail region. 33 events were selected where the spacecraft crossed through the current sheet from lobe to lobe within 15 minutes. The average thickness of the observed current sheets was 2.45R(E), and in 24 cases the current sheet was thinner than 3.OR(E); 6 very thin current sheets (thickness lambda < 0.5R(E)) were found. The electron data show that the very thin current sheets are associated with considerable temperature anisotropy. On average, the electron gradient current was approximately 17% of the total current, whereas the current arising from the electron temperature anisotropy varied between 8 - 45% of the total current determined from the lobe field magnitude. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. JET PROP LAB,PASADENA,CA 91109. RP PULKKINEN, TI (reprint author), FINNISH METEOROL INST,POB 503,SF-00101 HELSINKI,FINLAND. RI Owen, Christopher/C-2999-2008; Pulkkinen, Tuija/D-8403-2012 OI Owen, Christopher/0000-0002-5982-4667; Pulkkinen, Tuija/0000-0002-6317-381X NR 17 TC 41 Z9 41 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 NOV 19 PY 1993 VL 20 IS 22 BP 2427 EP 2430 DI 10.1029/93GL01590 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100004 ER PT J AU GOLDBERG, RA KOPP, E WITT, G SWARTZ, WE AF GOLDBERG, RA KOPP, E WITT, G SWARTZ, WE TI AN OVERVIEW OF NLC-91 - A ROCKET RADAR STUDY OF THE POLAR SUMMER MESOSPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MIDDLE ATMOSPHERE; CHARGED AEROSOLS; MESOPAUSE; ECHOES; CLOUDS AB In late July and early August of 1991, a major suborbital scientific campaign (NLC-91) involving scientists from eight countries was conducted at ESRANGE, Kiruna, Sweden and at Heiss Island, Russia. The purpose of the program was to investigate the chemical, dynamical, and electrodynamical properties of the polar summer mesosphere. Thirty one rocket flights were coordinated with two coherent radar facilities, EISCAT and CUPRI, and with other ground-based observatories and facilities. This permitted direct comparison between the in situ measurements and those obtained by remote sensing of the mesosphere via continuous ground-based monitoring. The primary objectives of the campaign were to study noctilucent clouds (NLCs) and polar mesospheric summer echoes (PMSEs), including their possible relationship to local aerosols and/or small scale turbulence. This overview describes the scientific program, discusses the geophysical conditions during launch activities, and reviews some of the preliminary results. More detailed results can be found in the papers which follow. C1 UNIV BERN,INST PHYS,CH-3012 BERN,SWITZERLAND. UNIV STOCKHOLM,ARRHENIUS LAB,DEPT METEOROL,S-10691 STOCKHOLM,SWEDEN. CORNELL UNIV,SCH ELECT ENGN,ITHACA,NY 14853. RP GOLDBERG, RA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,CODE 690,GREENBELT,MD 20771, USA. RI Goldberg, Richard /E-1881-2012 NR 18 TC 19 Z9 19 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 NOV 19 PY 1993 VL 20 IS 22 BP 2443 EP 2446 DI 10.1029/93GL03226 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100008 ER PT J AU PITTS, MC THOMASON, LW AF PITTS, MC THOMASON, LW TI THE IMPACT OF THE ERUPTIONS OF MOUNT-PINATUBO AND CERRO HUDSON ON ANTARCTIC AEROSOL LEVELS DURING THE 1991 AUSTRAL SPRING SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERIC AEROSOL; TRANSPORT AB At the beginning of the 1991 Austral spring, volcanic aerosols from Mt. Pinatubo and Cerro Hudson were present in the polar stratosphere of the Southern Hemisphere. Satellite observations of aerosol extinction were used to identify and track the movement of these aerosols in the vicinity of the Antarctic vortex during August through November 1991. A layer of mature Mt. Pinatubo aerosols was identified near 21 km and a layer of fresh Cerro Hudson aerosols was identified near 12 km. This altitude separation of the Mt. Pinatubo and Cerro Hudson aerosols was observed throughout the period. Below 15 km, the polar stratosphere was subject to episodes of strong wave activity which transported the Cerro Hudson aerosols poleward and, after the middle of September, they became a persistent feature beneath the vortex. Above 15 km, signatures of Mt. Pinatubo aerosols were observed near the vortex boundary, but significant portions of the vortex interior remained free of any detectable intrusions of Mt. Pinatubo aerosols until the final warming in mid-November. C1 NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,HAMPTON,VA 23665. RP PITTS, MC (reprint author), SCI APPLICAT INT CORP,1 ENTERPRISE PKWY,SUITE 250,HAMPTON,VA 23666, USA. NR 11 TC 24 Z9 24 U1 2 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 NOV 19 PY 1993 VL 20 IS 22 BP 2451 EP 2454 DI 10.1029/93GL02160 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100010 ER PT J AU ANDERSON, JG TOON, OB AF ANDERSON, JG TOON, OB TI AIRBORNE ARCTIC STRATOSPHERIC EXPEDITION .2. AN OVERVIEW SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AEROSOLS AB The sudden onset of ozone depletion in the antarctic vortex set a precedent for both the time scale and the severity of global change. The Airborne Antarctic Ozone Experiment (AAOE), staged from Punta Arenas, Chile, in 1987, established that CFCs, halons, and methyl bromide, the dominant sources of chlorine and bromine radicals in the stratosphere, control the rate of ozone destruction over the Antarctic; that the vortex is depleted in reactive nitrogen and water vapor; and that diabatic cooling during the antarctic winter leads to subsidence within the vortex core, importing air from higher altitudes and lower latitudes. This last conclusion is based on observed dramatic distortion in the tracer fields, most notably N2O. In 1989, the first Airborne Arctic Stratospheric Expedition (AASE-I), staged from Stavanger, Norway, and using the same aircraft employed for AAOE (the NASA ER-2 and the NASA DC-8), discovered that while NO(x) and to some degree NO(y) were perturbed within the arctic vortex, there was little evidence for desiccation. Under these (in contrast to the antarctic) marginally perturbed conditions, however, CIO was found to be dramatically enhanced such that a large fraction of the available (inorganic) chlorine resided in the form of ClO and its dimer ClOOCl. This leaves two abiding issues for the northern hemisphere and the mission of the second Airborne Arctic Stratospheric Expedition (AASE-II): (1) Will significant ozone erosion occur within the arctic vortex in the next ten years as chlorine loading in the stratosphere exceeds four parts per billion by volume? (2) Which mechanisms are responsible for the observed ozone erosion poleward of 30-degrees-N in the winter/spring northern hemisphere reported in satellite observations? C1 NASA,AMES RES CTR,DIV EARTH SYST SCI,MOFFETT FIELD,CA 94035. HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138. RP ANDERSON, JG (reprint author), HARVARD UNIV,DEPT CHEM,12 OXFORD ST,CAMBRIDGE,MA 02138, USA. NR 10 TC 44 Z9 44 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 19 PY 1993 VL 20 IS 22 BP 2499 EP 2502 DI 10.1029/93GL03118 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100025 ER PT J AU TOON, GC BLAVIER, JF SOLARIO, JN SZETO, JT AF TOON, GC BLAVIER, JF SOLARIO, JN SZETO, JT TI AIRBORNE OBSERVATIONS OF THE COMPOSITION OF THE 1992 TROPICAL STRATOSPHERE BY FTIR SOLAR ABSORPTION SPECTROMETRY SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ARCTIC WINTER STRATOSPHERE; ERUPTION; PINATUBO; NO2; HCL; AIR AB Vertical column measurements of the gaseous composition of the tropical stratosphere were made from the NASA DC-8 aircraft early in 1992. As anticipated, the burdens of the stratospheric source gases (e.g. O3, HF, HCl, ClNO3, HNO3) were reduced from their mid-latitude values due to increased uplift and photolysis. The tracers revealed considerably more uplift near the equator than the sub-tropics. For example, the HF burdens at +/-20-degrees-latitude (0.50x10(15) molec.cm-2) were nearly double those at 5-degrees-N (0.27x10(15) molec.cm-2). This, together with results obtained from other long-lived gases (e.g. N2O, CH4, CF2Cl2) indicates that volume mixing ratios found at 22 km altitude at mid-latitudes occurred at 26 km in the sub-tropics and at 30 km in the equatorial zone. This zone of uplift was symmetrical about the equator even though the sun was overhead at 20-degrees-S. RP TOON, GC (reprint author), JET PROP LAB,MS 183-301,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 13 TC 12 Z9 12 U1 0 U2 3 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 19 PY 1993 VL 20 IS 22 BP 2503 EP 2506 DI 10.1029/93GL01962 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100026 ER PT J AU KAWA, SR FAHEY, DW WILSON, JC SCHOEBERL, MR DOUGLASS, AR STOLARSKI, RS WOODBRIDGE, EL JONSSON, H LAIT, LR NEWMAN, PA PROFFITT, MH ANDERSON, DE LOEWENSTEIN, M CHAN, KR WEBSTER, CR MAY, RD KELLY, KK AF KAWA, SR FAHEY, DW WILSON, JC SCHOEBERL, MR DOUGLASS, AR STOLARSKI, RS WOODBRIDGE, EL JONSSON, H LAIT, LR NEWMAN, PA PROFFITT, MH ANDERSON, DE LOEWENSTEIN, M CHAN, KR WEBSTER, CR MAY, RD KELLY, KK TI INTERPRETATION OF NOX/NOY OBSERVATIONS FROM AASE-II USING A MODEL OF CHEMISTRY ALONG TRAJECTORIES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AIRCRAFT; STRATOSPHERE; ALTITUDE; AEROSOLS; CLO AB In situ measurements of NO and NO(y) are used to derive the ratio NO(x)/NO(y) along the flight track of the NASA ER-2 aircraft. Data are presented for two flights at mid-latitudes in October 1991 during the Airborne Arctic Stratospheric Expedition-II (AASE-II). Aerosol particle surface area was concurrently measured. The observations are compared with a photochemical model integrated along back trajectories from the aircraft flight track. Comparison of observations with the model run along trajectories and at a fixed position clearly and quantitatively demonstrates the importance of an air parcel's dynamic history in interpretation of local chemical observations. Comparison of the data with model runs under different assumptions regarding heterogeneous chemistry further reinforces the case for occurrence of the reaction of N2O5 + H2O on sulfate aerosol surfaces in the atmosphere. Finally, comparisons for which relative changes in the model and the data are not consistent caution that our ability to resolve all the observations is not yet complete. C1 JOHNS HOPKINS UNIV,APPL RES LAB,LAUREL,MD 20707. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NOAA,AERON LAB,BOULDER,CO 80303. UNIV DENVER,DEPT ENGN,DENVER,CO 80208. JET PROP LAB,PASADENA,CA 91109. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV SPACE RES ASSOC,GREENBELT,MD. RP KAWA, SR (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 916,GREENBELT,MD 20771, USA. RI Newman, Paul/D-6208-2012; Douglass, Anne/D-4655-2012; Kawa, Stephan/E-9040-2012; Stolarski, Richard/B-8499-2013; Fahey, David/G-4499-2013 OI Newman, Paul/0000-0003-1139-2508; Stolarski, Richard/0000-0001-8722-4012; Fahey, David/0000-0003-1720-0634 NR 16 TC 34 Z9 34 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 19 PY 1993 VL 20 IS 22 BP 2507 EP 2510 DI 10.1029/93GL01692 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100027 ER PT J AU SCHOEBERL, MR DOUGLASS, AR STOLARSKI, RS NEWMAN, PA LAIT, LR TOOHEY, D AVALLONE, L ANDERSON, JG BRUNE, W FAHEY, DW KELLY, K AF SCHOEBERL, MR DOUGLASS, AR STOLARSKI, RS NEWMAN, PA LAIT, LR TOOHEY, D AVALLONE, L ANDERSON, JG BRUNE, W FAHEY, DW KELLY, K TI THE EVOLUTION OF CLO AND NO ALONG AIR PARCEL TRAJECTORIES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID REACTIVE NITROGEN; VORTEX; STRATOSPHERE; TRACER; OXIDE AB Back trajectory analysis of Arctic and Antarctic aircraft data reveals that high ClO concentrations are associated with predicted polar stratospheric cloud (PSCs) encounters. The CIO concentrations within the Arctic and Antarctic polar vortices vary widely but appear to be inversely related to parcel solar exposure since the last PSC interaction. These results imply that production of NO(x) from HNO3 photolysis and reaction with OH is the mechanism for the loss of chlorine radicals through the reformation of chlorine nitrate. Highly denitrified air-parcels show no change in ClO with solar exposure. The recovery process is quantitatively duplicated using a model of chemistry along trajectories. Although PSC processing is the primary mechanism for producing elevated ClO amounts, back trajectories apparently unperturbed by PSC's also show slightly elevated ClO levels in 1992 compared to Arctic 1989 and Antarctic 1987 measurements presumably due to the presence of Pinatubo aerosol. C1 UNIV CALIF IRVINE,DEPT GEOSCI,IRVINE,CA 92717. HARVARD UNIV,ESL,ATMOSPHER RES PROJECT,CAMBRIDGE,MA 02138. PENN STATE UNIV,DEPT METEOROL,UNIV PK,PA 16802. NOAA,AERON LAB,BOULDER,CO 80303. RP SCHOEBERL, MR (reprint author), NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,CODE 916,GREENBELT,MD 20771, USA. RI Toohey, Darin/A-4267-2008; Newman, Paul/D-6208-2012; Douglass, Anne/D-4655-2012; Stolarski, Richard/B-8499-2013; Fahey, David/G-4499-2013 OI Toohey, Darin/0000-0003-2853-1068; Newman, Paul/0000-0003-1139-2508; Stolarski, Richard/0000-0001-8722-4012; Fahey, David/0000-0003-1720-0634 NR 17 TC 25 Z9 25 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 NOV 19 PY 1993 VL 20 IS 22 BP 2511 EP 2514 DI 10.1029/93GL01690 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100028 ER PT J AU WEAVER, A LOEWENSTEIN, M PODOLSKE, JR STRAHAN, SE PROFFITT, MH AIKIN, K MARGITAN, JJ JONSSON, HH BROCK, CA WILSON, JC TOON, OB AF WEAVER, A LOEWENSTEIN, M PODOLSKE, JR STRAHAN, SE PROFFITT, MH AIKIN, K MARGITAN, JJ JONSSON, HH BROCK, CA WILSON, JC TOON, OB TI EFFECTS OF PINATUBO AEROSOL ON STRATOSPHERIC OZONE AT MIDLATITUDES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID POLAR VORTEX; HETEROGENEOUS CHEMISTRY; DEPLETION; ERUPTION; WINTER AB Mid-latitude ozone data from ER-2 aircraft measurements in 1989, 1991 and 1992 were examined to determine how sulfate aerosols from the eruption of Mt. Pinatubo had affected ozone at about 18 km. N2O was used as a tracer to help distinguish between chemical and dynamical aerosol effects. At 20-45-degrees-N in February 1992, ozone was about 10-20% lower than February 1989 and 1991, with respect to N2O. Data from Aug. 1991-Mar. 1992 showed changes in ozone with respect to N2O, but the magnitude of those changes was not correlated with the magnitude of the changes in aerosol surface area density. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. JET PROP LAB,PASADENA,CA 91109. UNIV DENVER,DEPT ENGN,DENVER,CO 80208. RP WEAVER, A (reprint author), NOAA,AERON LAB,325 S BROADWAY,BOULDER,CO 80302, USA. RI Brock, Charles/G-3406-2011; Strahan, Susan/H-1965-2012; Aikin, Kenneth/I-1973-2013 OI Brock, Charles/0000-0002-4033-4668; NR 29 TC 7 Z9 7 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 NOV 19 PY 1993 VL 20 IS 22 BP 2515 EP 2518 DI 10.1029/93GL02633 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100029 ER PT J AU AVALLONE, LM TOOHEY, DW PROFFITT, MH MARGITAN, JJ CHAN, KR ANDERSON, JG AF AVALLONE, LM TOOHEY, DW PROFFITT, MH MARGITAN, JJ CHAN, KR ANDERSON, JG TI IN-SITU MEASUREMENTS OF CLO AT MIDLATITUDES - IS THERE AN EFFECT FROM MT-PINATUBO SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HETEROGENEOUS CHEMISTRY; LOWER STRATOSPHERE; OZONE; ERUPTION; WINTER AB Observations of CIO from 20 to 60-degrees-N made before and after the eruption of Mt. Pinatubo are compared for changes which may result from increased sulfate aerosol surface area. Using ozone as a vertical coordinate and examining data at similar latitudes and seasons, elevated abundances of ClO are found at low latitudes (20 to 30-degrees-N), an effect which decreases with increasing latitude. For the flights compared, there appear to be no differences, within the uncertainty of the measurements, at latitudes poleward of 40-degrees-N. These results are consistent with the idea that the hydrolysis of N2O5 on sulfate aerosols becomes saturated at moderate aerosol loadings. C1 UNIV CALIF IRVINE,DEPT GEOSCI,IRVINE,CA 92717. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NOAA,AERON LAB,BOULDER,CO 80303. JET PROP LAB,PASADENA,CA 91109. RP AVALLONE, LM (reprint author), HARVARD UNIV,DEPT CHEM,40 OXFORD ST,CAMBRIDGE,MA 02138, USA. RI Toohey, Darin/A-4267-2008 OI Toohey, Darin/0000-0003-2853-1068 NR 22 TC 23 Z9 23 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 NOV 19 PY 1993 VL 20 IS 22 BP 2519 EP 2522 DI 10.1029/93GL02418 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100030 ER PT J AU WEBSTER, CR MAY, RD TOOHEY, DW AVALLONE, LM ANDERSON, JG SOLOMON, S AF WEBSTER, CR MAY, RD TOOHEY, DW AVALLONE, LM ANDERSON, JG SOLOMON, S TI IN-SITU MEASUREMENTS OF THE CLO/HCL RATIO - HETEROGENEOUS PROCESSING ON SULFATE AEROSOLS AND POLAR STRATOSPHERIC CLOUDS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID O3 AB Simultaneous in situ measurements of stratospheric ClO and HCl have been made for the first time, during numerous flights of the ER-2 aircraft covering latitudes 24-90-degrees-N from October 1991 through March 1992. The ClO/HCl ratio is identified as a key indicator of heterogenous processing both outside and within the Arctic polar vortex. For ClO mixing ratios below about 120 pptv, remarkably constant ClO/HCl values of about 15% characterize the lower stratosphere. The observed values are significantly higher than those derived from a 2-D model using either gas phase photochechemistry alone (2%), or including heterogeneous sulfate chemistry (5-10%). During the Arctic early spring, after conversion of HCI into reactive chlorine has taken place, the vortex edge is poorly defined by ClO levels. Loss of HCl and its slow recovery following low-temperature polar heterogeneous chemistry distinguishes HCl as a new and unique dynamical tracer of PSC-processed air. C1 UNIV CALIF IRVINE,IRVINE,CA 92717. HARVARD UNIV,CAMBRIDGE,MA 02138. NOAA,AERON LAB,BOULDER,CO 80303. RP WEBSTER, CR (reprint author), JET PROP LAB,4800 OAK GROVE DR,183-401,PASADENA,CA 91109, USA. RI Toohey, Darin/A-4267-2008 OI Toohey, Darin/0000-0003-2853-1068 NR 18 TC 14 Z9 14 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 NOV 19 PY 1993 VL 20 IS 22 BP 2523 EP 2526 DI 10.1029/93GL01963 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100031 ER PT J AU DESSLER, AE STIMPFLE, RM DAUBE, BC SALAWITCH, RJ WEINSTOCK, EM JUDAH, DM BURLEY, JD MUNGER, JW WOFSY, SC ANDERSON, JG MCCORMICK, MP CHU, WP AF DESSLER, AE STIMPFLE, RM DAUBE, BC SALAWITCH, RJ WEINSTOCK, EM JUDAH, DM BURLEY, JD MUNGER, JW WOFSY, SC ANDERSON, JG MCCORMICK, MP CHU, WP TI BALLOON-BORNE MEASUREMENTS OF CLO, NO, AND O3 IN A VOLCANIC CLOUD - AN ANALYSIS OF HETEROGENEOUS CHEMISTRY BETWEEN 20 AND 30 KM SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERE; O-3; NITROGEN AB Balloon profiles of chlorine monoxide (ClO), nitric oxide (NO), and ozone (O3) were measured on March 11, 1992 from 100 to 10 mb over Greenland (67.0-degrees-N, 50.6-degrees-W). Measurements from SAGE II indicate that the aerosol surface area in the region was enhanced by sulfur from the eruption of Mt. Pinatubo, reaching 50 times background near 20 km. Concentrations of CIO were enhanced and concentrations of NO were suppressed relative to low aerosol conditions consistent with the effects of hydrolysis of N2O5 on the surface of sulfuric acid aerosols. The data are consistent with a value of 2x10(-4) for the reaction probability of the heterogeneous hydrolysis of ClONO2, indicating a minor role for this reaction at a temperature of 220 K. At these temperatures, we find no evidence for the catastrophic loss of ozone predicted to occur under conditions of enhanced aerosol surface area. C1 HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138. HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138. HARVARD UNIV,DEPT PHYS,CAMBRIDGE,MA 02138. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP DESSLER, AE (reprint author), HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138, USA. RI Salawitch, Ross/B-4605-2009; Munger, J/H-4502-2013; Dessler, Andrew/G-8852-2012 OI Salawitch, Ross/0000-0001-8597-5832; Munger, J/0000-0002-1042-8452; Dessler, Andrew/0000-0003-3939-4820 NR 18 TC 15 Z9 15 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 NOV 19 PY 1993 VL 20 IS 22 BP 2527 EP 2530 DI 10.1029/93GL02419 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100032 ER PT J AU LOEWENSTEIN, M PODOLSKE, JR FAHEY, DW WOODBRIDGE, EL TIN, P WEAVER, A NEWMAN, PA STRAHAN, SE KAWA, SR SCHOEBERL, MR LAIT, LR AF LOEWENSTEIN, M PODOLSKE, JR FAHEY, DW WOODBRIDGE, EL TIN, P WEAVER, A NEWMAN, PA STRAHAN, SE KAWA, SR SCHOEBERL, MR LAIT, LR TI NEW OBSERVATIONS OF THE NOY/N2O CORRELATION IN THE LOWER STRATOSPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TOTAL REACTIVE NITROGEN; SPACELAB-3; TRACER; OXIDE; N2O AB During the Airborne Arctic Stratospheric Expedition II (AASE II), September 1991 through March 1992, in situ measurements of reactive nitrogen (NO(y)) and N2O were made in the Northern Hemisphere lower stratosphere. We present an analysis of this new data and compare it with results from similar data taken during AASE in the winter of 1989. In the Northern Hemisphere there is a consistent linear correlation of N2O and NO(y) which shows no interannual variation. Cases of departure from a linear correlation are examined and classified as being due to denitrification (NO(y) loss) or sampling air from a region where the photochemical lifetime of NO(y) is decreased. The latter case was observed for the first time in the winter of 1992. C1 NOAA,AERON LAB,BOULDER,CO 80303. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP LOEWENSTEIN, M (reprint author), NASA,AMES RES CTR,MS 2455,MOFFETT FIELD,CA 94035, USA. RI Newman, Paul/D-6208-2012; Kawa, Stephan/E-9040-2012; Strahan, Susan/H-1965-2012; Fahey, David/G-4499-2013 OI Newman, Paul/0000-0003-1139-2508; Fahey, David/0000-0003-1720-0634 NR 16 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 NOV 19 PY 1993 VL 20 IS 22 BP 2531 EP 2534 DI 10.1029/93GL03004 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100033 ER PT J AU PODOLSKE, JR LOEWENSTEIN, M WEAVER, A STRAHAN, SE CHAN, KR AF PODOLSKE, JR LOEWENSTEIN, M WEAVER, A STRAHAN, SE CHAN, KR TI NORTHERN-HEMISPHERE NITROUS-OXIDE MORPHOLOGY DURING THE 1989 AASE AND THE 1991-1992 AASE-II CAMPAIGNS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTIC OZONE EXPERIMENT; MIDDLE ATMOSPHERE; POLAR VORTEX; N2O; AIRCRAFT; CHLORINE; TRACER; MODEL; ER-2 AB Nitrous oxide vertical profiles and latitudinal distributions for the 1989 AASE and 1992 AASE II northern polar winters are developed from the ATLAS N2O dataset, using both potential temperature and pressure as vertical coordinates. Morphologies show strong descent occurring poleward of the polarjet. The AASE II morphology shows a mid latitude ''surf zone'', characterized by strong horizontal mixing, and a horizontal gradient south of 30-degrees-N due to the sub-tropical jet. These features are similar to those produced by two-dimensional photochemical models which include coupling between transport, radiation, and chemistry. C1 NOAA,AERON LAB,BOULDER,CO 80303. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP PODOLSKE, JR (reprint author), NASA,AMES RES CTR,MS 245-5,MOFFETT FIELD,CA 94035, USA. RI Strahan, Susan/H-1965-2012 NR 17 TC 11 Z9 11 U1 1 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 19 PY 1993 VL 20 IS 22 BP 2535 EP 2538 DI 10.1029/93GL03005 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100034 ER PT J AU ANDERSON, BE COLLINS, JE SACHSE, GW WHITING, GW BLAKE, DR ROWLAND, FS AF ANDERSON, BE COLLINS, JE SACHSE, GW WHITING, GW BLAKE, DR ROWLAND, FS TI AASE-II OBSERVATIONS OF TRACE CARBON SPECIES DISTRIBUTIONS IN THE MID TO UPPER TROPOSPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID METHANE; POLLUTION; DIOXIDE; AEROSOL; BARROW; ALASKA AB We report tropospheric (altitudes > 5 km) observations of CO2, CO, CH4, and light hydrocarbons (C2 - C4) over the latitude range from 90-degrees-N to 23-degrees-S recorded onboard the NASA DC-8 aircraft during the winter 1992 Second Airborne Arctic Stratospheric Expedition (AASE-II). Mixing ratios for these species exhibited significant north-south gradients with maximum values in subpolar and arctic regions and minima over the southern tropics. At latitudes > 40-degrees-N, the mixing ratios of most species increased significantly over the course of the 3-month measurement period. Also at high northern latitudes, the variations of all relatively long-lived reactive carbon species were linearly correlated with fluctuations-of CO2 with CO, CH4, C2H6, C2H2, C3H8, and n-C4H10 exhibiting average enhancement ratios in terms of ppbv(X)/ppmv(CO2) of 13.8, 8.4, 0.21, 0.075, 0.085, and 0.037, respectively. C1 UNIV CALIF IRVINE,DEPT CHEM,IRVINE,CA 92717. SCI & TECHNOL CORP,HAMPTON,VA. CHRISTOPHER NEWPORT UNIV,NEWPORT NEWS,VA. RP ANDERSON, BE (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 483,HAMPTON,VA 23665, USA. NR 16 TC 23 Z9 23 U1 1 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 19 PY 1993 VL 20 IS 22 BP 2539 EP 2542 DI 10.1029/93GL01693 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100035 ER PT J AU COLLINS, JE SACHSE, GW ANDERSON, BE WEINHEIMER, AJ WALEGA, JG RIDLEY, BA AF COLLINS, JE SACHSE, GW ANDERSON, BE WEINHEIMER, AJ WALEGA, JG RIDLEY, BA TI AASE-II IN-SITU TRACER CORRELATIONS OF METHANE, NITROUS-OXIDE, AND OZONE AS OBSERVED ABOARD THE DC-8 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AIRCRAFT AB We report in situ stratospheric measurements of CH4, N2O, and O3 obtained aboard the NASA DC-8 during the January-March 1992 Airborne Arctic Stratospheric Expedition Il field campaign. These data demonstrate a strong linear correlation between N2O and CH4 in the lower stratosphere thus indicating that both species are effective tracers of stratospheric air motion. Measurements of both species on constant geometric height surfaces indicate that significant subsidence of the arctic stratospheric air mass occurred at DC-8 altitudes over the course of the AASE-II expedition. In addition, a widespread reduction in O3 mixing ratios (up to 20%) relative to these conserved tracers was also observed in the lower stratosphere in March as compared to January and February results. C1 SCI & TECHNOL CORP,HAMPTON,VA. NATL CTR ATMOSPHER RES,BOULDER,CO 80307. RP COLLINS, JE (reprint author), NASA,LANGLEY RES CTR,MAILSTOP 472,HAMPTON,VA 23665, USA. NR 12 TC 24 Z9 24 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 NOV 19 PY 1993 VL 20 IS 22 BP 2543 EP 2546 DI 10.1029/93GL02624 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100036 ER PT J AU CHAN, KR PFISTER, L BUI, TP BOWEN, SW DEANDAY, J GARY, BL FAHEY, DW KELLY, KK WEBSTER, CR MAY, RD AF CHAN, KR PFISTER, L BUI, TP BOWEN, SW DEANDAY, J GARY, BL FAHEY, DW KELLY, KK WEBSTER, CR MAY, RD TI A CASE-STUDY OF MOUNTAIN LEE WAVE EVENT OF JANUARY 6, 1992 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INSITU MEASUREMENTS; POLAR; STRATOSPHERE; ATMOSPHERE; NITROGEN; N2O AB A mountain wave event, observed at the southern tip of Greenland on January 6, 1992, was corroborated by three experiments: the Meteorological Measurement System (MMS), the Microwave Temperature Profiler (MTP), and the Reactive Nitrogen Instrument (NO/NO(y)). Gravity wave signatures with classical phase relationship between wind and temperature were observed on both the outbound and inbound legs at different altitudes. The waves showed both vertically propagating and evanescent properties. Characteristics of the dominant wave mode are: wavelength almost-equal-to 35 km; vertical displacement almost-equal-to 0.8 km, and peak-to-peak vertical wind almost-equal-to 6 ms-1. With the prevailing wind at almost-equal-to 37 ms-1, the stratospheric temperature was reduced by 6K to 195.5K within 8 minutes. The implication and potential impact of mountain lee waves on the formation of polar stratospheric clouds (PSC's) are discussed. C1 SAN JOSE STATE UNIV,SAN JOSE,CA 95172. JET PROP LAB,PASADENA,CA 91109. NOAA,AERON LAB,BOULDER,CO 80303. RP CHAN, KR (reprint author), NASA,AMES RES CTR,MS 245-5,MOFFETT FIELD,CA 94035, USA. RI Fahey, David/G-4499-2013 OI Fahey, David/0000-0003-1720-0634 NR 12 TC 12 Z9 12 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 NOV 19 PY 1993 VL 20 IS 22 BP 2551 EP 2554 DI 10.1029/93GL01964 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100038 ER PT J AU BROCK, CA JONSSON, HH WILSON, JC DYE, JE BAUMGARDNER, D BORRMANN, S PITTS, MC OSBORN, MT DECOURSEY, RJ WOODS, DC AF BROCK, CA JONSSON, HH WILSON, JC DYE, JE BAUMGARDNER, D BORRMANN, S PITTS, MC OSBORN, MT DECOURSEY, RJ WOODS, DC TI RELATIONSHIPS BETWEEN OPTICAL EXTINCTION, BACKSCATTER AND AEROSOL SURFACE AND VOLUME IN THE STRATOSPHERE FOLLOWING THE ERUPTION OF MT-PINATUBO SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SULFURIC-ACID; LIDAR; MASS; HUMIDITY AB The eruption of the Mt. Pinatubo volcano in the Philippines in June 1991 has resulted in increases in the surface and mass concentrations of aerosol particles in the lower stratosphere. Airborne measurements made at midlatitudes between 15 and 21 km from August 1991 to March 1992 show that, prior to December 1991, the Pinatubo aerosol cloud varied widely in microphysical properties such as size distribution, number, surface and volume concentrations and was also spatially variable. Aerosol surface area concentration was found to be highly correlated to extinction at visible and near-infrared wavelengths throughout the measurement period. Similarly, backscatter at common lidar wavelengths was a good predictor of aerosol volume concentrations. These results support the use of satellite extinction measurements to estimate aerosol surface and of lidar measurements to estimate aerosol volume or mass if temporal changes in the relationships between the variables are considered. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. SCI APPLICAT INT CORP,HAMPTON,VA 23665. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP BROCK, CA (reprint author), UNIV DENVER,DEPT ENGN,DENVER,CO 80208, USA. RI Borrmann, Stephan/E-3868-2010; Brock, Charles/G-3406-2011 OI Brock, Charles/0000-0002-4033-4668 NR 19 TC 29 Z9 30 U1 1 U2 5 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 19 PY 1993 VL 20 IS 22 BP 2555 EP 2558 DI 10.1029/93GL01691 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100039 ER PT J AU BORRMANN, S DYE, JE BAUMGARDNER, D WILSON, JC JONSSON, HH BROCK, CA LOEWENSTEIN, M PODOLSKE, JR FERRY, GV BARR, KS AF BORRMANN, S DYE, JE BAUMGARDNER, D WILSON, JC JONSSON, HH BROCK, CA LOEWENSTEIN, M PODOLSKE, JR FERRY, GV BARR, KS TI IN-SITU MEASUREMENTS OF CHANGES IN STRATOSPHERIC AEROSOL AND THE N2O- AEROSOL RELATIONSHIP INSIDE AND OUTSIDE OF THE POLAR VORTEX SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SIZE DISTRIBUTIONS; DENITRIFICATION AB Two optical particle counters on the ER-2, together covering a particle size diameter range from 0.1 mum to 23 mum, were used to measure the aerosol bulk quantities integral number, aerosol surface and volume, as well as detailed size distributions inside and outside of the polar vortex in the lower stratosphere. While AASE I (Arctic Airborne Stratospheric Expedition, (Dec. 88-Feb. 89) was conducted in a period of relative volcanic quiescence, enhancements in aerosol number, surface and volume of factors around 10, 25 and 100 were observed during AASE Il (Aug. 91-Mar. 92) due to the eruption of Mt. Pinatubo. The changes in these bulk quantities as well as in the size distributions measured both outside and inside the the polar vortex are presented and compared with those obtained in polar stratospheric cloud events (AASE I). Except for a shift towards larger aerosol mixing ratios the general shape of correlograms between the measured N2O and particle mixing ratios remain similar before and after the eruption. Similar correlograms are used to interpret data from vertical profiles inside and outside of the polar vortex. C1 UNIV DENVER,DEPT ENGN,DENVER,CO 80208. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP BORRMANN, S (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. RI Borrmann, Stephan/E-3868-2010; Brock, Charles/G-3406-2011 OI Brock, Charles/0000-0002-4033-4668 NR 10 TC 21 Z9 21 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 19 PY 1993 VL 20 IS 22 BP 2559 EP 2562 DI 10.1029/93GL01694 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100040 ER PT J AU WEINHEIMER, AJ WALEGA, JG RIDLEY, BA SACHSE, GW ANDERSON, BE COLLINS, JE AF WEINHEIMER, AJ WALEGA, JG RIDLEY, BA SACHSE, GW ANDERSON, BE COLLINS, JE TI STRATOSPHERIC NOY MEASUREMENTS ON THE NASA DC-8 DURING AASE-II SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID WINTER POLAR STRATOSPHERES; ODD NITROGEN; OZONE; DENITRIFICATION AB We survey measurements of stratospheric NO(y) on the NASA DC-8 during AASE II in early 1992. Emphasis is on correlations with other long-lived species: O3, N2O, and CH4. No cases of extremely high NO(y)/O3 ratios were seen in 1992. This suggests that denitrification at higher altitudes was less pervasive than in 1989. Values of NO(y)/O3 in 1992 are comparable to, though perhaps lower than, those measured in 1989. The correlation of NO(y); with N2O changes over the course of the mission. Relative to the correlation for the whole season, low values of NO(y) occur in February, most notably on the 22nd. The reason for the low NO(y) is unknown. It is generally too warm at DC-8 altitudes for the presence of PSC particles, but denitrification at higher altitudes, followed by descent, might account for the low values seen on 22 February. However, this may be unlikely since the NASA ER-2, flying during the same period, saw no evidence of denitrification at higher altitudes [Loewenstein et al., 1993]. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. SCI & TECHNOL CORP,HAMPTON,VA. RP WEINHEIMER, AJ (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. NR 15 TC 42 Z9 42 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 19 PY 1993 VL 20 IS 22 BP 2563 EP 2566 DI 10.1029/93GL02627 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100041 ER PT J AU SCHAUFFLER, SM HEIDT, LE POLLOCK, WH GILPIN, TM VEDDER, JF SOLOMON, S LUEB, RA ATLAS, EL AF SCHAUFFLER, SM HEIDT, LE POLLOCK, WH GILPIN, TM VEDDER, JF SOLOMON, S LUEB, RA ATLAS, EL TI MEASUREMENTS OF HALOGENATED ORGANIC-COMPOUNDS NEAR THE TROPICAL TROPOPAUSE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRACE GASES; ATMOSPHERE; LATITUDES AB The amount of organic chlorine and bromine entering the stratosphere have a direct influence on the magnitude of chlorine and bromine catalyzed ozone losses. Twelve organic chlorine species and five organic bromine species were measured from 12 samples collected near the tropopause between 23.8-degrees-N and 25.3-degrees-N during AASE II. The average mixing ratios of total organic chlorine and total organic bromine were 3.50 +/- 0.06 ppbv and 21.1 +/- 0.8 pptv, respectively. CH3Cl represented 15.1% of the total organic chlorine, with CFC 11 (CCl3F) and CFC 12 (CCl2F2) accounting for 22.6% and 28.2%, respectively, with the remaining 34. 1 % primarily from CCl4, CH3CCl3, and CFC 113 (CCl2FCClF2). CH3Br represented 54% of the total organic bromine. The 95% confidence intervals of the mixing ratios of all but four of the individual compounds were within the range observed in low and mid-latitude mid-troposphere samples. The four compounds with significantly lower mixing ratios at the tropopause were CHCl3, CH2Cl2, CH2Br2, and CH3CC13. The lower mixing ratios may be due to entrainment of southern hemisphere air during vertical transport in the tropical region and/or to exchange of air across the tropopause between the lower stratosphere and upper troposphere. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NOAA,AERON LAB,BOULDER,CO 80303. SAN JOSE STATE UNIV,SAN JOSE,CA 95192. RP SCHAUFFLER, SM (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. RI Atlas, Elliot/J-8171-2015 NR 11 TC 114 Z9 115 U1 0 U2 10 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 19 PY 1993 VL 20 IS 22 BP 2567 EP 2570 DI 10.1029/93GL02840 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100042 ER PT J AU RUSSELL, PB LIVINGSTON, JM PUESCHEL, RF REAGAN, JA BROWELL, EV TOON, GC NEWMAN, PA SCHOEBERL, MR LAIT, LR PFISTER, L GAO, Q HERMAN, BM AF RUSSELL, PB LIVINGSTON, JM PUESCHEL, RF REAGAN, JA BROWELL, EV TOON, GC NEWMAN, PA SCHOEBERL, MR LAIT, LR PFISTER, L GAO, Q HERMAN, BM TI POST-PINATUBO OPTICAL DEPTH SPECTRA VS LATITUDE AND VORTEX STRUCTURE - AIRBORNE TRACKING SUNPHOTOMETER MEASUREMENTS IN AASE-II SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AEROSOLS; ERUPTION; OZONE AB In January and March 1992, DC-8-measured stratospheric particle optical depth spectra, tau(p)(lambda), peaked broadly at midvisible or longer wavelengths. At mid-to-high northern latitudes outside the vortex, tau(p)(526 nm) above about 11 km was as large as 0.22 in both January and March, reflecting continued Pinatubo volcanic influence. In both months, in-vortex tau(p)(lambda) above 11 km was smaller than outside-vortex values by a factor of two or more, and in January a strong anticorrelation was observed between tau(p)(lambda) and HF column content (an indicator of vortex penetration). In late January at 18-20S, near the edge of the southern subtropical jet, tau(p)(526 nm) above 12 km was only about 0.07-0.09, with a flatter spectral shape than northern mid- to high-latitude measurements in both January and March. Occasional high-latitude vertical profiles indicate 6-11-km slab optical depths, DELTAtau(p)(526 nm), of 0.05 to 0.1, which should be added to the above-11-km values to yield values above 6 km. C1 SRI INT,MENLO PK,CA 94025. UNIV ARIZONA,TUCSON,AZ 85721. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP RUSSELL, PB (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. RI Newman, Paul/D-6208-2012 OI Newman, Paul/0000-0003-1139-2508 NR 20 TC 31 Z9 31 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 NOV 19 PY 1993 VL 20 IS 22 BP 2571 EP 2574 DI 10.1029/93GL03006 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100043 ER PT J AU VALERO, FPJ PLATNICK, S KINNE, S PILEWSKIE, P BUCHOLTZ, A AF VALERO, FPJ PLATNICK, S KINNE, S PILEWSKIE, P BUCHOLTZ, A TI AIRBORNE BRIGHTNESS TEMPERATURE-MEASUREMENTS OF THE POLAR WINTER TROPOSPHERE AS PART OF THE AIRBORNE ARCTIC STRATOSPHERE EXPERIMENT-II AND THE EFFECT OF BRIGHTNESS TEMPERATURE-VARIATIONS ON THE DIABATIC HEATING IN THE LOWER STRATOSPHERE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTIC OZONE EXPERIMENT; CLOUDS AB In this paper we report radiometric measurements of tropospheric brightness temperatures obtained during the AASE II experiment. These measurements represent the first attempt to characterize effective radiative temperatures as seen from above the troposphere during the Arctic winter. The reported measurements include brightness temperatures at 6.7 and 10.5mum as seen from the NASA DC-8 aircraft flying at about 11 km altitude. We also present radiative transfer calculations to estimate the effect of tropospheric brightness temperature on the lower stratospheric heating rates. Because of the recent massive eruption of the Pinatubo volcano, we also discuss the effects of a volcanic aerosol layer. It is concluded that small particles like the volcanic aerosol or PSCs type 1 do not affect stratospheric heating rates by much; on the other hand, larger particles, PSCs types 2 and 3, may have significant effects on heating rates and consequently on dynamics of the lower stratosphere. The dynamical effects of local stratospheric temperature variations are briefly discussed. RP VALERO, FPJ (reprint author), NASA,AMES RES CTR,MS 245-4,MOFFETT FIELD,CA 94035, USA. RI Platnick, Steven/J-9982-2014 OI Platnick, Steven/0000-0003-3964-3567 NR 13 TC 2 Z9 2 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 NOV 19 PY 1993 VL 20 IS 22 BP 2575 EP 2578 DI 10.1029/93GL03003 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MJ641 UT WOS:A1993MJ64100044 ER PT J AU CESS, RD ZHANG, MH POTTER, GL BARKER, HW COLMAN, RA DAZLICH, DA DELGENIO, AD ESCH, M FRASER, JR GALIN, V GATES, WL HACK, JJ INGRAM, WJ KIEHL, JT LACIS, AA LETREUT, H LI, ZX LIANG, XZ MAHFOUF, JF MCAVANEY, BJ MELESHKO, VP MORCRETTE, JJ RANDALL, DA ROECKNER, E ROYER, JF SOKOLOV, AP SPORYSHEV, PV TAYLOR, KE WANG, WC WETHERALD, RT AF CESS, RD ZHANG, MH POTTER, GL BARKER, HW COLMAN, RA DAZLICH, DA DELGENIO, AD ESCH, M FRASER, JR GALIN, V GATES, WL HACK, JJ INGRAM, WJ KIEHL, JT LACIS, AA LETREUT, H LI, ZX LIANG, XZ MAHFOUF, JF MCAVANEY, BJ MELESHKO, VP MORCRETTE, JJ RANDALL, DA ROECKNER, E ROYER, JF SOKOLOV, AP SPORYSHEV, PV TAYLOR, KE WANG, WC WETHERALD, RT TI UNCERTAINTIES IN CARBON-DIOXIDE RADIATIVE FORCING IN ATMOSPHERIC GENERAL-CIRCULATION MODELS SO SCIENCE LA English DT Article ID SURFACE-TEMPERATURE; CLIMATE FEEDBACK; CO2 AB Global warming, caused by an increase in the concentrations of greenhouse gases, is the direct result of greenhouse gas-induced radiative forcing. When a doubling of atmospheric carbon dioxide is considered, this forcing differed substantially among 15 atmospheric general circulation models. Although there are several potential causes, the largest contributor was the carbon dioxide radiation parameterizations of the models. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. CANADIAN CLIMATE CTR,DOWNSVIEW M3H 5T4,ON,CANADA. BUR METEOROL RES CTR,MELBOURNE,VIC 3001,AUSTRALIA. COLORADO STATE UNIV,FT COLLINS,CO 80523. NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025. MAX PLANCK INST METEOROL,W-2000 HAMBURG 13,GERMANY. RUSSIAN ACAD SCI,DEPT NUMER MATH,MOSCOW 117334,RUSSIA. NATL CTR ATMOSPHER RES,BOULDER,CO 80307. METEOROL OFF,HADLEY CTR CLIMATE PREDICT & RES,BRACKNELL RG12 2SY,BERKS,ENGLAND. LAB METEOROL DYNAM,F-75231 PARIS 05,FRANCE. SUNY ALBANY,ATMOSPHER SCI RES CTR,ALBANY,NY 12205. CTR NATL RECH METEOROL,DIRECT METEOROL NATL,F-31057 TOULOUSE,FRANCE. VOEIKOV MAIN GEOPHYS OBSERV,ST PETERSBURG 194018,RUSSIA. EUROPEAN CTR MEDIUM RANGE WEATHER FORECASTS,READING RG2 9AX,BERKS,ENGLAND. PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08544. RP CESS, RD (reprint author), SUNY STONY BROOK,MARINE SCI RES CTR,INST TERR & PLANETARY ATMOSPHERES,STONY BROOK,NY 11794, USA. RI Taylor, Karl/F-7290-2011; Lacis, Andrew/D-4658-2012; Del Genio, Anthony/D-4663-2012; Randall, David/E-6113-2011; Sporyshev, Petr/P-7323-2015; OI Taylor, Karl/0000-0002-6491-2135; Del Genio, Anthony/0000-0001-7450-1359; Randall, David/0000-0001-6935-4112; Sporyshev, Petr/0000-0002-4047-8178; Li, Laurent/0000-0002-3855-3976 NR 11 TC 64 Z9 66 U1 1 U2 11 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 19 PY 1993 VL 262 IS 5137 BP 1252 EP 1255 DI 10.1126/science.262.5137.1252 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MH324 UT WOS:A1993MH32400035 PM 17772648 ER PT J AU MAITRE, P BAUSCHLICHER, CW AF MAITRE, P BAUSCHLICHER, CW TI THEORETICAL-STUDY OF THE H-2-ML(+) BINDING-ENERGIES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAUSSIAN-BASIS SETS; TRANSITION-METAL ATOMS; MOLECULAR CALCULATIONS; ELECTRON CORRELATION; PERTURBATION-THEORY; 1ST; 1ST-ROW; IONS; COMPLEXES; ORBITALS AB The cooperative ligand effects are studied in MLH(2)(+) and the results are compared to the recent experiments of Kemper et al. The bonding in these compounds is principally electrostatic in origin; however, ligand to metal and metal to ligand donations are important, especially for H-2. We show that differences arise among the vanadium, cobalt, and copper complexes which are due to 3d donation to H-2. Electron correlation is required to describe the dative interaction, and we find that second order Moller-Plesset perturbation theory (MP2) yields a good description of these systems compared with higher levels of correlation (such as the modified coupled pair functional and coupled cluster approaches) and experiment. However, obtaining quantitative results requires higher levels of theory than MP2. RP MAITRE, P (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RI Maitre, Philippe/C-1022-2013 OI Maitre, Philippe/0000-0003-2924-1054 NR 43 TC 42 Z9 42 U1 0 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 18 PY 1993 VL 97 IS 46 BP 11912 EP 11920 DI 10.1021/j100148a012 PG 9 WC Chemistry, Physical SC Chemistry GA MH563 UT WOS:A1993MH56300012 ER PT J AU ZHANG, SN FISHMAN, GJ HARMON, BA PACIESAS, WS AF ZHANG, SN FISHMAN, GJ HARMON, BA PACIESAS, WS TI IMAGING HIGH-ENERGY ASTROPHYSICAL SOURCES USING EARTH OCCULTATION SO NATURE LA English DT Article ID X-RAY; GALACTIC-CENTER; APERTURE SYNTHESIS; ASTRONOMY AB HIGH-ENERGY astrophysical sources can be difficult to image. Photons with energies above approximately 5 keV are hard to focus, so experiments usually employ coded masks1-4 or moving collimators5-9 to modulate the flux received by the detectors; the resulting signals are then deconvolved to form the images. Here we demonstrate a new approach which makes use of the large-area, non-collimated detectors of the Burst and Transient Source Experiment on the Compton Gamma-Ray Observatory. As the spacecraft moves in its orbit, the Earth itself acts as a stable occulting disk. Changes in the measured signal during a single occultation correspond to the integrated intensity of sources positioned along the arc described by the Earth's edge (limb). The low-altitude, moderately inclined orbit of the spacecraft ensures that the angle at which the limb traverses a source region varies between occultations, and thus data from a series of occultations can be transformed into an image. This imaging process is conceptually and mathematically similar to those used in fan-beam aperture-synthesis radio-astronomy10 and medical computer-assisted tomography11, and holds great promise for all-sky imaging with relatively simple (and hence inexpensive) detectors. C1 UNIV SPACE RES ASSOC,HUNTSVILLE,AL 35806. UNIV ALABAMA,HUNTSVILLE,AL 35899. RP ZHANG, SN (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,CODE ES66,HUNTSVILLE,AL 35812, USA. NR 29 TC 41 Z9 41 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD NOV 18 PY 1993 VL 366 IS 6452 BP 245 EP 247 DI 10.1038/366245a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MH325 UT WOS:A1993MH32500056 ER PT J AU NOOR, AK HADIAN, MJ ANDERSEN, CM AF NOOR, AK HADIAN, MJ ANDERSEN, CM TI HYBRID ANALYTICAL TECHNIQUE FOR EVALUATING THE SENSITIVITY OF THE NONLINEAR VIBRATIONAL RESPONSE OF BEAMS SO COMPUTERS & STRUCTURES LA English DT Article AB A three-step hybrid analytical technique is presented for evaluating the nonlinear vibrational response as well as the first-order sensitivity coefficients of thin-walled beams (derivatives of the nonlinear frequency with respect to material and geometric parameters of the beam). The first step involves the generation of various-order perturbation functions, and their derivatives with respect to the material and geometric parameters of the beam, using the Linstedt-Poincare perturbation technique. The second step consists of using the perturbation functions as coordinate (or approximation) functions and then computing the amplitudes of these functions and the nonlinear frequency via a direct variational procedure. The third step consists of using the perturbation functions, and their derivatives, as coordinate functions and computing the sensitivity coefficients of the nonlinear frequency via a second application of the direct variational procedure. The analytical formulation is based on a form of the geometrically nonlinear beam theory with the effects of in-plane inertia, rotatory inertia, transverse shear deformation, and cross-sectional warping included. The effectiveness of the proposed technique is demonstrated by means of a numerical example of thin-walled beam with a doubly symmetric I-section. C1 COLL WILLIAM & MARY,WILLIAMSBURG,VA 23185. RP NOOR, AK (reprint author), UNIV VIRGINIA,NASA,LANGLEY RES CTR,CTR COMPUTAT STRUCT TECHNOL,HAMPTON,VA 23681, USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-7949 J9 COMPUT STRUCT JI Comput. Struct. PD NOV 17 PY 1993 VL 49 IS 4 BP 569 EP 577 DI 10.1016/0045-7949(93)90061-H PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA MT915 UT WOS:A1993MT91500001 ER PT J AU REDDY, JN STARNES, JH AF REDDY, JN STARNES, JH TI GENERAL BUCKLING OF STIFFENED CIRCULAR CYLINDRICAL-SHELLS ACCORDING TO A LAYERWISE THEORY SO COMPUTERS & STRUCTURES LA English DT Article ID VIBRATION; PLATES AB Analytical solutions for buckling loads of composite cylindrical shells with axial and circumferential stiffeners are presented using a layerwise shell theory. The layerwise shell theory accounts for displacement variations through the thickness of the shell. The effect of stiffeners is averaged over the domain of the shell, and the effect of stiffener eccentricity is taken into account. The Navier solution procedure is used to develop analytical solutions for buckling of stiffened cylindrical shells. Numerical results are presented to illustrate the accuracy of the layerwise shell theory in comparison to single-layer shell theories. C1 NASA,LANGLEY RES CTR,AIRCRAFT STRUCT BRANCH,HAMPTON,VA 23665. RP REDDY, JN (reprint author), TEXAS A&M UNIV,DEPT MECH ENGN,COLL STN,TX 77843, USA. NR 51 TC 26 Z9 26 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-7949 J9 COMPUT STRUCT JI Comput. Struct. PD NOV 17 PY 1993 VL 49 IS 4 BP 605 EP 616 DI 10.1016/0045-7949(93)90065-L PG 12 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA MT915 UT WOS:A1993MT91500005 ER PT J AU LAMBRECHT, WRL SEGALL, B SUTTROP, W YOGANATHAN, M DEVATY, RP CHOYKE, WJ EDMOND, JA POWELL, JA ALOUANI, M AF LAMBRECHT, WRL SEGALL, B SUTTROP, W YOGANATHAN, M DEVATY, RP CHOYKE, WJ EDMOND, JA POWELL, JA ALOUANI, M TI OPTICAL REFLECTIVITY OF 3C AND 4H-SIC POLYTYPES - THEORY AND EXPERIMENT SO APPLIED PHYSICS LETTERS LA English DT Article ID EXCHANGE-CORRELATION POTENTIALS; BAND-STRUCTURE; SEMICONDUCTORS AB Experimental and theoretical optical reflectivity in the range 4-10 eV are reported for the 3C and 4H polytypes of SiC. The calculations used the linear muffin-tin orbital method and the local density approximation. Good agreement in peak positions and line shape is obtained except for a nearly constant shift of similar to 1.00 eV. C1 UNIV PITTSBURGH,DEPT PHYS & ASTRON,PITTSBURGH,PA 15260. CREE RES INC,DURHAM,NC 27713. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. RP LAMBRECHT, WRL (reprint author), CASE WESTERN RESERVE UNIV,DEPT PHYS,CLEVELAND,OH 44106, USA. RI Alouani, Mebarek/A-9101-2011; Lambrecht, Walter/O-1083-2016 OI Alouani, Mebarek/0000-0002-7985-5276; NR 16 TC 41 Z9 41 U1 0 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 15 PY 1993 VL 63 IS 20 BP 2747 EP 2749 DI 10.1063/1.110322 PG 3 WC Physics, Applied SC Physics GA MG674 UT WOS:A1993MG67400011 ER PT J AU VAZQUEZ, J AF VAZQUEZ, J TI OBSERVATIONS ON THE LONG-PERIOD VARIABILITY OF THE GULF-STREAM DOWNSTREAM OF CAPE-HATTERAS SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORTH-ATLANTIC; MEANDERS; GEOSAT; PROPAGATION; TRANSPORT; VORTEX; WAVES; MODEL; JETS AB To examine the long-period variability of the Gulf Stream, sea level residuals relative to a 2-year mean sea level in the Gulf Stream downstream of Cape Hatteras (between 75-degrees-W and 60-degrees-W longitude) are used. Residuals, as derived from Geosat altimetry between November 1986 and December 1988, were gridded in space and time at a temporal resolution of 10 days and spatial resolution of 1/4. Complex empirical orthogonal function (CEOF) analysis was applied to the data set to extract the spatially correlated signal with the original data subsampled to 1/2-degrees. In addition to determining the space-time scales and propagation characteristics of the different modes, wavenumber-frequency spectral techniques were used to separate the variability into propagating and stationary components. The CEOF technique applied to the data set indicated that the first four CEOF modes accounted for 60% of the variability and were found to be above the noise level 99% of the time. CEOF 1 was associated with westward propagation at 5 km/d at a wavelength of 2000 km and eastward propagation at 1-2 km/d centered at a 500-km wavelength. This first CEOF is in good agreement with thin-jet equivalent barotropic models which predict westward propagation for wavelengths greater than 1130 km. A deflection of the wavelike pattern at 65-degrees-W also indicates a possible topographic effect. A simple scaling of the effect of topography indicates that for length scales longer than the internal Rossby radius of deformation, the topographic term is at least of the same order of magnitude as the beta effect. The second CEOF was more broadbanded in wavenumber space, with eastward propagation occurring in a wavenumber-frequency band between 300 and 1400 km and 0.5 and 2.0 cycles/yr. The third CEOF is similar in structure to the first, but with less energy. CEOF 4 was clearly identifiable with higher frequencies than the first three with westward propagation at 4 km/d. The spatial location of this mode along with the westward propagation indicates possible influences from eddy-stream interactions. Thus topography, Rossby wave dynamics, and eddy-stream interactions all appear to have a significant role in determining the space-time scales and propagation properties of the long-period response of sea level in the Gulf Stream. RP VAZQUEZ, J (reprint author), JET PROP LAB,4800 OAK GROVE DR,M-S 300-323,PASADENA,CA 91109, USA. NR 43 TC 7 Z9 7 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-OCEANS JI J. Geophys. Res.-Oceans PD NOV 15 PY 1993 VL 98 IS C11 BP 20133 EP 20147 DI 10.1029/93JC02002 PG 15 WC Oceanography SC Oceanography GA MH750 UT WOS:A1993MH75000007 ER PT J AU DEVEAUX, RD GORDON, AL COMISO, JC BACHERER, NE AF DEVEAUX, RD GORDON, AL COMISO, JC BACHERER, NE TI MODELING OF TOPOGRAPHIC EFFECTS ON ANTARCTIC SEA-ICE USING MULTIVARIATE ADAPTIVE REGRESSION SPLINES SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WINTER MIXED LAYER; SOUTHERN-OCEAN; MAUD RISE; INSITU OBSERVATIONS; WEDDELL GYRE; MICROWAVE AB The role of seafloor topography in the spatial variations of the southern ocean sea ice cover as observed (every other clay) by the Nimbus 7 scanning multichannel microwave radiometer satellite in the yews 1980, 1983, and 1984 is studied. Bottom bathymetry can affect sea ice surface characteristics because of the basically barotropic circulation of the ocean south of the Antarctic Circumpolar current. The main statistical tool used to quantify this effect is a local nonparametric regression model of sea ice concentration as a function of the depth and its first two derivatives in both meridional and zonal directions. First, we model the relationship of bathymetry to sea ice concentration in two study areas, one over the Maud Rise and the other over the Ross Sea shelf region. The multiple correlation coefficient is found to average 44% in the Maud Rise study area and 62% in the Ross Sea study area over the years 1980, 1983, and 1984. Second, a strategy of dividing the entire Antarctic region into an overlapping mosaic of small areas, or windows, is considered. Keeping the windows small reduces the correlation of bathymetry with other factors such as wind, sea temperature, and distance to the continent. We find that although the form of the model varies from window to window due to the changing role of other relevant environmental variables, we are left with a spatially consistent ordering of the relative importance of the topographic predictors. For a set of three representative days in the Austral winter of 1980, the analysis shows that an average of 54% of the spatial variation in sea ice concentration over the entire ice cover can be attributed to topographic variables. The results thus support the hypothesis that there is a sea ice to bottom bathymetry link. However, this should not undermine the considerable influence of wind, current, and temperature which affect the ice distribution directly and are partly responsible for the observed bathymetric effects. C1 COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964. NASA,GODDARD SPACE FLIGHT CTR,HYDROSPHER PROC LAB,GREENBELT,MD 20771. RP DEVEAUX, RD (reprint author), PRINCETON UNIV,SCH ENGN & APPL SCI,PRINCETON,NJ 08544, USA. RI Gordon, Arnold/H-1049-2011 OI Gordon, Arnold/0000-0001-6480-6095 NR 21 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 NOV 15 PY 1993 VL 98 IS C11 BP 20307 EP 20319 DI 10.1029/93JC01503 PG 13 WC Oceanography SC Oceanography GA MH750 UT WOS:A1993MH75000019 ER PT J AU ROACH, AT AAGAARD, K CARSEY, FD AF ROACH, AT AAGAARD, K CARSEY, FD TI OBSERVATIONS OF VERTICAL CURRENTS AND CONVECTION IN THE CENTRAL GREENLAND SEA DURING THE WINTER OF 1988-1989 - COMMENT SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Note C1 JET PROP LAB,PASADENA,CA 91109. RP ROACH, AT (reprint author), UNIV WASHINGTON,APPL PHYS LAB,1013 NE 40TH ST,SEATTLE,WA 98105, USA. NR 2 TC 1 Z9 1 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 NOV 15 PY 1993 VL 98 IS C11 BP 20335 EP 20335 DI 10.1029/93JC02924 PG 1 WC Oceanography SC Oceanography GA MH750 UT WOS:A1993MH75000023 ER PT J AU WARWICK, RS SEMBAY, S YAQOOB, T MAKISHIMA, K OHASHI, T TASHIRO, M KOHMURA, Y AF WARWICK, RS SEMBAY, S YAQOOB, T MAKISHIMA, K OHASHI, T TASHIRO, M KOHMURA, Y TI X-RAY-PROPERTIES OF ACTIVE GALAXIES WITH HIGH INTRINSIC ABSORPTION SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE GALAXIES, ACTIVE; X-RAYS, GALAXIES ID EMISSION-LINE GALAXIES; SEYFERT-GALAXIES; GALACTIC NUCLEI; UNIFIED MODEL; COLD MATTER; EXOSAT; VARIABILITY; REFLECTION; SPECTRUM; SAMPLE AB We present the results of Ginga observations of three narrow emission line X-ray galaxies, NGC 7172, NGC 7582 and ESO 103-G35. In each of these galaxies the column density along the line of sight to the active nucleus is extremely high (i.e. n(H) greater-than-or-similar-to 10(23) cm-2). A comparison of the optical depth in the iron K-edge with the low-energy absorption in the X-ray spectrum indicates an apparent iron abundance in excess of the solar value in these sources. Measurements of the iron K-edge energy show that the bulk of the X-ray-absorbing gas is not strongly photoionized, with only ESO 103-G35 exhibiting an edge energy significantly above that for neutral iron. In the case of NGC7582, the line-of-sight column density may have increased by a factor of approximately 3 over an interval of about 4 yr. The implications of these results for current models of the state and distribution of gaseous material in low-luminosity active galactic nuclei are briefly discussed. C1 NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. UNIV TOKYO,DEPT PHYS,BUNKYO KU,TOKYO 113,JAPAN. RP WARWICK, RS (reprint author), UNIV LEICESTER,DEPT PHYS & ASTRON,LEICESTER LE1 7RH,ENGLAND. RI Tashiro, Makoto/J-4562-2012 NR 52 TC 46 Z9 46 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 NOV 15 PY 1993 VL 265 IS 2 BP 412 EP 420 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MF854 UT WOS:A1993MF85400017 ER PT J AU EBY, PB AF EBY, PB TI ELECTRON AND POSITRON EMISSION ANGLE DISTRIBUTIONS IN PAIR PRODUCTION BY RELATIVISTIC HEAVY-IONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID CROSS-SECTION; COLLISIONS AB The cross section for direct electron-positron pair production by relativistic heavy ions, differential in the emission angle of one of the particles, is calculated using lowest order QED theory. A general method is given for computing all the terms in the exact lowest order expression, based on previous work. Some numerical results are given for selected incident particle energies and the results are compared with the corresponding calculation using the Weizsacker-Williams method. RP EBY, PB (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812, USA. NR 17 TC 3 Z9 3 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 15 PY 1993 VL 336 IS 1-2 BP 189 EP 199 DI 10.1016/0168-9002(93)91097-7 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA MG766 UT WOS:A1993MG76600024 ER PT J AU VADAS, SL AF VADAS, SL TI NUMERICAL EVOLUTION OF GENERAL-RELATIVISTIC VOIDS SO PHYSICAL REVIEW D LA English DT Article ID BIG-BUBBLE PROBLEM; EXTENDED INFLATION; EXPANDING UNIVERSE; 1ST-ORDER INFLATION; DOMINATED UNIVERSE; THIN SHELL; EXPANSION; RADIATION AB In this paper, we study the evolution of a superhorizon-sized void embedded in a radiation-dominated Friedmann-Robertson-Walker universe. We numerically solve the spherically symmetric general relativistic equations in comoving, synchronous coordinates. Initially, the fluid inside the void is taken to be homogeneous and nonexpanding. When the fluid inside the void is relativistic, we find that radiation diffuses into the void at approximately the speed of light as a strong shock-the void collapses in general. We also find the surprising result that the cosmic collapse time (the first-crossing time) for a relativistic or nonrelativistic void is much smaller than previously thought, because it depends not only on the initial void radius, but also on the ratio of the temperature inside the void (or the particle mass if the void is nonrelativistic) to the temperature outside. Under certain conditions (e.g., if the void is empty enough), the collapse occurs in less than the Hubble time outside the void. This quick collapse time revises the current picture of superhorizon-sized void evolution after first-order inflation. In addition, it introduces the possibility that superhorizon-sized voids may thermalize and homogenize relatively quickly. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. RP VADAS, SL (reprint author), UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637, USA. NR 44 TC 8 Z9 8 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1993 VL 48 IS 10 BP 4562 EP 4594 DI 10.1103/PhysRevD.48.4562 PG 33 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA MJ061 UT WOS:A1993MJ06100009 ER PT J AU TURNER, MS WHITE, M LIDSEY, JE AF TURNER, MS WHITE, M LIDSEY, JE TI TENSOR PERTURBATIONS IN INFLATIONARY MODELS AS A PROBE OF COSMOLOGY SO PHYSICAL REVIEW D LA English DT Article ID MICROWAVE-BACKGROUND ANISOTROPY; COLD DARK MATTER; GRAVITATIONAL-WAVES; EXTENDED INFLATION; SCALE ANISOTROPIES; GRAND UNIFICATION; UNIVERSE; RADIATION; COBE; CONSTRAINTS AB In principle, the tensor metric (gravity-wave) perturbations that arise in inflationary models can, beyond probing the underlying inflationary model, provide information about the Universe: ionization history, presence of a cosmological constant, and epoch of matter-radiation equality. Because tensor perturbations give rise to the anisotropy of the cosmic background radiation (CBR) solely through the Sachs-Wolfe effect we are able to calculate analytically their contribution to the variance of the multipole moments of the CBR temperature anisotropy. In so doing, we carefully take account of the effect of tensor perturbations that entered the Hubble radius during both the matter-dominated and radiation-dominated epochs by means of a transfer function. (Previously, only those modes that entered during the matter era were properly taken into account.) The striking feature in the spectrum of multipole amplitudes is a dramatic falloff for 1 greater than or similar to square-root 1 + z(LSS), where z(LSS) is the redshift of the last-scattering surface, which depends upon the ionization history of the Universe. Finally, using our transfer function we provide a more precise formula for the energy density in stochastic gravitational waves from inflation, and, using the Cosmic Background Explorer Differential Microwave Radiometer (COBE DMR) quadrupole normalization, we express this energy density in terms of the ''tilt'' of the spectrum of tensor perturbations alone and show that it is unlikely that the stochastic background of gravity waves can be detected directly in the foreseeable future. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. RP TURNER, MS (reprint author), UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637, USA. RI White, Martin/I-3880-2015 OI White, Martin/0000-0001-9912-5070 NR 47 TC 113 Z9 113 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1993 VL 48 IS 10 BP 4613 EP 4622 DI 10.1103/PhysRevD.48.4613 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA MJ061 UT WOS:A1993MJ06100013 ER PT J AU KRISHER, TP AF KRISHER, TP TI PARAMETRIZED POST-NEWTONIAN GRAVITATIONAL REDSHIFT SO PHYSICAL REVIEW D LA English DT Article ID GRAVITY AB A derivation of the gravitational redshift effect to order c-4 is presented. The calculation is performed within the framework of the parametrized post-Newtonian formalism for analyzing metric theories of gravity, which includes corrections to second order in the Newtonian potential, gravitomagnetic contributions, and preferred-frame terms. We briefly discuss how to generalize our results to include possible violations of local Lorentz invariance or local position invariance which can arise in non-metric theories. Our results are useful for analyzing possible new redshift experiments which may be sensitive to second-order effects, such as a space mission involving a close solar flyby. RP KRISHER, TP (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 20 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1993 VL 48 IS 10 BP 4639 EP 4644 DI 10.1103/PhysRevD.48.4639 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA MJ061 UT WOS:A1993MJ06100016 ER PT J AU CALDWELL, RR AF CALDWELL, RR TI GREEN-FUNCTIONS FOR GRAVITATIONAL-WAVES IN FRW SPACETIMES SO PHYSICAL REVIEW D LA English DT Article AB A method for calculating the retarded Green's function for the gravitational wave equation in Friedmann-Robertson-Walker spacetimes within the formalism of linearized Einstein gravity is developed. Hadamard's general solution to Cauchy's problem for second-order, linear partial differential equations is applied to the FRW gravitational wave equation. The retarded Green's function may be calculated for any FRW spacetime, with curved or flat spatial sections, for which the functional form of the Ricci scalar curvature R is known. The retarded Green's function for gravitational waves propagating through a cosmological fluid composed of both radiation and dust is calculated analytically for the first time. It is also shown that for all FRW spacetimes in which the Ricci scalar curvatures does not vanish, R not-equal 0, the Green's function violates Huygens' principle; the Green's function has support inside the light cone due to the scattering of gravitational waves off the background curvature. RP CALDWELL, RR (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,POB 500,BATAVIA,IL 60510, USA. OI Caldwell, Robert/0000-0001-7490-7463 NR 27 TC 10 Z9 10 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1993 VL 48 IS 10 BP 4688 EP 4692 DI 10.1103/PhysRevD.48.4688 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA MJ061 UT WOS:A1993MJ06100022 ER PT J AU MARGEVICIUS, RW LEWANDOWSKI, JJ LOCCI, IE NOEBE, RD AF MARGEVICIUS, RW LEWANDOWSKI, JJ LOCCI, IE NOEBE, RD TI YIELD-POINT BEHAVIOR IN NIAL SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID HYDROSTATIC-PRESSURE C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP MARGEVICIUS, RW (reprint author), CASE WESTERN RESERVE UNIV,DEPT MAT SCI & ENGN,CLEVELAND,OH 44106, USA. NR 19 TC 12 Z9 12 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD NOV 15 PY 1993 VL 29 IS 10 BP 1309 EP 1312 DI 10.1016/0956-716X(93)90129-G PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA LZ594 UT WOS:A1993LZ59400010 ER PT J AU BAUSCHLICHER, CW SODUPE, M AF BAUSCHLICHER, CW SODUPE, M TI A STUDY OF THE GROUND AND LOW-LYING STATES OF MGCH4+ SO CHEMICAL PHYSICS LETTERS LA English DT Article ID MOLECULAR WAVE-FUNCTIONS; GAUSSIAN-BASIS SETS; ANO BASIS-SETS; 2ND ROW ATOMS; PHOTODISSOCIATION SPECTROSCOPY; POLARIZATION; CONTRACTION AB The geometries and vibrational frequencies have been computed for the ground and low-lying excited states of MgMH4+. While the ground state and the excited state, derived from exciting the Mg+ 3s-like electron to the 3psigma orbital, have eta3 geometries, the two excited states derived from occupying the Mg 3ppi orbital have eta2 configurations. The binding energies of these eta2 states are significantly larger than that in the ground state. C1 UNIV AUTONOMA BARCELONA, DEPT QUIM, UNITAT QUIM FIS, E-08193 BARCELONA, SPAIN. RP BAUSCHLICHER, CW (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RI Sodupe, Mariona/E-9352-2013 OI Sodupe, Mariona/0000-0003-0276-0524 NR 24 TC 30 Z9 31 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 12 PY 1993 VL 214 IS 5 BP 489 EP 494 DI 10.1016/0009-2614(93)85671-A PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA MF362 UT WOS:A1993MF36200011 ER PT J AU CONNERNEY, JEP BARON, R SATOH, T OWEN, T AF CONNERNEY, JEP BARON, R SATOH, T OWEN, T TI IMAGES OF EXCITED H3+ AT THE FOOT OF THE IO FLUX TUBE IN JUPITER ATMOSPHERE SO SCIENCE LA English DT Article ID HUBBLE SPACE TELESCOPE; WAVE CURRENT SYSTEM; MU-M; H-3+; MAGNETOSPHERE; AURORAE AB The electrodynamic interaction between Io and the Jovian magnetosphere drives currents to and from the planet's ionosphere, where H-3+ emission is excited. Direct images of this phenomenon were obtained with the ProtoCAM infrared camera at the National Aeronautics and Space Administration's 3-m Infrared Telescope Facility. The emissions are localized to the instantaneous foot of the Io flux tube, almost-equal-to 8-degrees equatorward of the more intense auroral H-3+ emission associated with higher magnetic latitudes. The foot of the Io flux tube leads that of (undisturbed) model magnetic field lines passing through Io by 15-degrees to 20-degrees in longitude and is less visible in the northern hemisphere at longitudes where the surface magnetic field strength is greatest. These data favor the unipolar inductor model of the Io interaction and provide insight into the source location and generation of Jovian decameter radio emission. C1 UNIV HAWAII,INST ASTRON,HONOLULU,HI 96822. RP CONNERNEY, JEP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771, USA. RI connerney, john/I-5127-2013; OI connerney, jack/0000-0001-7478-6462 NR 28 TC 167 Z9 167 U1 0 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 12 PY 1993 VL 262 IS 5136 BP 1035 EP 1038 DI 10.1126/science.262.5136.1035 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MG187 UT WOS:A1993MG18700029 PM 17782051 ER PT J AU MONKS, PS NESBITT, FL SCANLON, M STIEF, LJ AF MONKS, PS NESBITT, FL SCANLON, M STIEF, LJ TI HOBR KINETICS - REACTIONS OF HALOGEN ATOMS, OXYGEN-ATOMS, NITROGEN-ATOMS, AND NITRIC-OXIDE WITH HOBR SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID TEMPERATURE-DEPENDENCE; RATE-CONSTANT; SEMIEMPIRICAL METHODS; ATMOSPHERIC BROMINE; ANTARCTIC OZONE; DEPLETION; CHLORINE; BRO; OPTIMIZATION; PARAMETERS AB Relatively little is known about the role of HOBr in stratospheric chemistry. Potentially, HOBr could act as a temporary reservoir for stratospheric BrO(y) compounds. Recently, the first direct measurement of the rate coefficient for the reaction BrO + HO2 --> HOBr + O2, which is thought to be the main production channel for HOBr in the stratosphere, was found to be 6 times larger than previously suggested at (3.3 +/- 0.5) x 10(-11) cm3 molecule-1 s-1. In this work we have investigated the reactions of HOBr with F(2P), Cl(2P), O(3P), N(4S), Br(2P), and NO(2PI) using the discharge-flow kinetic technique coupled to mass spectrometric detection. The HOBr was formed in situ by the reaction sequence F + H2O --> OH + HF, OH + Br2 --> HOBr + Br. Using an excess of the atomic species or NO, the rate coefficients at T 298 K for the HOBr reactions were determined to be k(F) = (2.0 +/- 0.7) X 10(-10), k(Cl) = (1.1 +/- 0.3) x 10(-10), k(O) = (2.5 +/- 0.4) x 10(-11), k(N) < 2 X 10(-13), and k(NO) < 5 X 10(-14) (all units CM3 molecule-1 s-1). No reaction between Br + HOBr could be observed, but it was not possible to quantify this because of the large amount of interference from background Br2 on the HOBr signal. This study represents the first determination of the rate constants for these reactions. Attention is paid to possible interferences from reaction of HOBr precursors. The reactions of HOBr with Cl and 0 are markedly faster than the analogous reactions of HOCl. The atmospheric lifetime of HOBr with respect to reaction with 0 is ca. 0.03 h and with respect to reaction with Cl is ca. 9.6 h at z = 35 km (calculated maxima in [HOBr]). RP MONKS, PS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771, USA. RI Monks, Paul/H-6468-2016 OI Monks, Paul/0000-0001-9984-4390 NR 52 TC 24 Z9 24 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 11 PY 1993 VL 97 IS 45 BP 11699 EP 11705 DI 10.1021/j100147a025 PG 7 WC Chemistry, Physical SC Chemistry GA MG299 UT WOS:A1993MG29900025 ER PT J AU HAMMEL, HB NELSON, RM AF HAMMEL, HB NELSON, RM TI BRIGHT FLASH ON JUPITER IN 1983 SO NATURE LA English DT Letter C1 JET PROP LAB,PASADENA,CA 91109. RP HAMMEL, HB (reprint author), MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139, USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD NOV 11 PY 1993 VL 366 IS 6451 BP 117 EP 117 DI 10.1038/366117a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MG216 UT WOS:A1993MG21600037 ER PT J AU ZOHAR, S AF ZOHAR, S TI SPECTRAL WINDOW OF THE ACOUSTOOPTIC FOLDED SPECTRUM ANALYZER SO APPLIED OPTICS LA English DT Article DE ACOUSTOOPTIC SPECTRAL ANALYSIS; SPECTRAL WINDOW; SPECTRAL RESOLUTION AB I derive here the spectral window of the acousto-optic folded spectrum analyzer proposed by [K. Wagner and D. Psaltis, Proc. Soc. Photo-Opt. Instrum. Eng. 564,209-223(1985)]. This window function turns out to be quite informative. It clarifies important characteristics that distinguish this system from the more conventional digital spectrum analyzers, and it clarifies the relationships between various system design parameters and helps guide their selection. The spectral window of one specific implementation of a finer-resolution version of this analyzer (the super-fine-resolution variant suggested in the above reference) is also determined. Analysis shows that for certain narrow-frequency ranges this window has two main lobes separated by a large number of super-fine frequency-resolution bins. This characteristic makes it unacceptable in many applications. RP ZOHAR, S (reprint author), CALTECH, JET PROP LAB, PASADENA, CA 91125 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 10 PY 1993 VL 32 IS 32 BP 6445 EP 6455 PG 11 WC Optics SC Optics GA MG301 UT WOS:A1993MG30100004 PM 20856482 ER PT J AU SWARTZ, DA SULKANEN, ME AF SWARTZ, DA SULKANEN, ME TI HELIUM-LIKE IRON LINE TEMPERATURE DIAGNOSTICS IN CLUSTERS OF GALAXIES SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, CLUSTERING; LINE, FORMATION; X-RAYS, GALAXIES ID DIELECTRONIC SATELLITE SPECTRA; X-RAY SPECTROSCOPY; COOLING FLOWS; HOT PLASMA; IONS; EINSTEIN; EXCITATION; EMISSION; RATES; SPECTROMETER AB The emission complex around approximately 6.7 keV, arising from He-like Fe lines and their dielectronic satellites, has been observed at low resolution in a number of clusters of galaxies. With sufficient spectral resolution as in, e.g., solar flare observations, the ratio, G = (x + y + z)/w, of the intercombination (x and y) and forbidden (z) to the resonance (w) lines arising from the n = 2 level of the He-like ion, is a sensitive temperature diagnostic. We examine this role for G in the context of spatially and spectrally resolved observations of clusters of galaxies. The temperature behavior of this ratio is strongly dependent on the spectral resolution. We introduce an alternative definition for G that includes the contribution of satellite lines and improves the temperature fidelity of this diagnostic. We find that deprojection of the observed value of G along a. line of sight through the cluster can yield accurate temperature profiles for temperatures in the range 10(7)-10(8) K that do not suffer from the cluster model uncertainties inherent in deconvolution of broad-band X-ray surface brightness profiles. RP SWARTZ, DA (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,X RAY ASTRON BRANCH,ES-65,HUNTSVILLE,AL 35812, USA. NR 41 TC 7 Z9 7 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 1993 VL 417 IS 2 BP 487 EP 493 DI 10.1086/173327 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MD971 UT WOS:A1993MD97100008 ER PT J AU HOWARD, S KEEL, WC BYRD, G BURKEY, J AF HOWARD, S KEEL, WC BYRD, G BURKEY, J TI A SIMULATION ATLAS OF TIDAL FEATURES IN GALAXIES SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, INTERACTIONS; GALAXIES, KINEMATICS AND DYNAMICS; METHODS, NUMERICAL; VIDEOTAPES ID BINARY GALAXIES; DISK GALAXY; SPIRAL ARMS; M31; ENCOUNTERS; DYNAMICS AB Detailed simulations of tidally induced structure in disk galaxies have either concentrated on specific systems or consisted of a few encounters with relatively small numbers of particles and no self-gravity. Observers need a ''dictionary'' of simulations that covers many encounter parameters with fine morphological resolution and includes effects of self-gravitation. Observers can then search the dictionary for the parameters that best match a particular observed morphology. Alternatively, the dictionary can be used with observational samples for statistical studies of system parameters. To fill this need, we present a survey of model tidal encounters using a self-gravitating, 180,000 particle, two-component (''stars'' and ps'') disk. A wide variety of fascinating morphologies results. There are 86 different encounters that vary orbit tilt, perigalacticon distance, galaxy to companion mass ratio, and the amount of halo dark matter relative to the disk. For morphological comparisons, over 1700 images of the entire survey are available in video form. While there is a rich variety of tidal structure covering much of this parameter space, some general patterns may be remarked. There is a strong orbital inclination dependence of the symmetry of tidal patterns, most symmetric for planar orbits and nearly one-sided for polar encounters. Retrograde encounters produce only broad fanlike global patterns, but rich small-scale internal structure. In both kinds of encounter, our numerical resolution allows us to track internal spiral structure driven by the outer material arms, especially in the lighter halo simulations. We note also that polar encounters generate series of expanding, essentially non-rotating loops resembling shell structures in some respects. C1 NASA,MSFC,HUNTSVILLE,AL 35812. UNIV ALABAMA,DEPT PHYS & ASTRON,TUSCALOOSA,AL 35487. RP HOWARD, S (reprint author), UNIV SPACE RES ASSOC,4950 CORP DR,SUITE 100,HUNTSVILLE,AL 35806, USA. OI Keel, William/0000-0002-6131-9539 NR 41 TC 53 Z9 53 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 1993 VL 417 IS 2 BP 502 EP 514 DI 10.1086/173329 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MD971 UT WOS:A1993MD97100010 ER PT J AU LEE, MG FREEDMAN, WL MADORE, BF AF LEE, MG FREEDMAN, WL MADORE, BF TI THE TIP OF THE RED GIANT BRANCH AS A DISTANCE INDICATOR FOR RESOLVED GALAXIES SO ASTROPHYSICAL JOURNAL LA English DT Article DE CEPHEIDS; GALAXIES, DISTANCES AND REDSHIFTS; HERTZSPRUNG-RUSSELL (H-R) DIAGRAM; STARS, DISTANCES; STARS, EVOLUTION; STARS, GIANTS ID RR LYRAE STARS; LOCAL GROUP GALAXIES; DWARF ELLIPTICAL GALAXIES; STELLAR POPULATIONS; NEARBY GALAXIES; SCALE; PHOTOMETRY; IC-1613; NGC-147; HALO AB We show that the I magnitude of the tip of the first-ascent red giant branch (TRGB) of low-mass stars is a distance indicator for resolved galaxies with metal-poor ([Fe/H] < -0.7 dex) old populations, having a precision comparable to primary distance indicators such as Cepheids and RR Lyraes. A comparison of the distances to resolved galaxies based on the TRGB with those derived from Cepheids and RR Lyraes shows that they agree within +/-0.1 mag. Advantages of the TRGB method are discussed. C1 CALTECH,JET PROPULS LAB,CTR INFRARED PROC & ANAL,NASA,IPAC EXTRAGALACT DATABASE,PASADENA,CA 91101. RP LEE, MG (reprint author), CARNEGIE OBSERV,813 SANTA BARBARA ST,PASADENA,CA 91101, USA. NR 45 TC 436 Z9 439 U1 2 U2 4 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 1993 VL 417 IS 2 BP 553 EP 559 DI 10.1086/173334 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MD971 UT WOS:A1993MD97100015 ER PT J AU HILDEBRAND, RH DAVIDSON, JA DOTSON, J FIGER, DF NOVAK, G PLATT, SR TAO, L AF HILDEBRAND, RH DAVIDSON, JA DOTSON, J FIGER, DF NOVAK, G PLATT, SR TAO, L TI POLARIZATION OF THE THERMAL EMISSION FROM THE DUST RING AT THE CENTER OF THE GALAXY SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXY, CENTER; INFRARED, INTERSTELLAR, CONTINUUM; POLARIZATION ID GALACTIC-CENTER; MAGNETIC-FIELD; SAGITTARIUS-A; INFRARED OBSERVATIONS; ACCRETION DISKS; SGR-A; ENVIRONMENT; POLARIMETRY; LUMINOSITY; FILAMENTS AB We present new results on the polarization of the far-infrared emission from the dust ring at the center of the Galaxy. Previous far-infrared polarimetry of the region has been confined to the main ridge of emission. The new measurements cover the entire area of the ring. Polarization maps computed for magnetic fields with biaxial symmetry cannot be made to fit the data. Maps computed for axisymmetric fields provide much better fits, but the results show that the ring and field cannot both have ideal symmetry. The dispersion of the measured position angles about the directions computed from the self-similar model of Wardle & Konigl (1990) is comparable to the dispersion about mean values observed in the most orderly dark clouds. The observed polarization is consistent with a model which deviates from axisymmetry by a small distortion of the field or by nonuniform distribution of the emitting dust. C1 UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP HILDEBRAND, RH (reprint author), UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637, USA. NR 37 TC 43 Z9 43 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 1993 VL 417 IS 2 BP 565 EP 571 DI 10.1086/173336 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MD971 UT WOS:A1993MD97100017 ER PT J AU ASCHWANDEN, MJ BENZ, AO SCHWARTZ, RA AF ASCHWANDEN, MJ BENZ, AO SCHWARTZ, RA TI THE TIMING OF ELECTRON-BEAM SIGNATURES IN HARD X-RAY AND RADIO - SOLAR-FLARE OBSERVATIONS BY BATSE COMPTON-GAMMA-RAY-OBSERVATORY AND PHOENIX SO ASTROPHYSICAL JOURNAL LA English DT Article DE SUN, CORONA; SUN, FLARES; SUN, PARTICLE EMISSION; SUN, RADIO RADIATION; SUN, X-RAYS, GAMMA RAYS ID BURST GROUPS; III BURSTS; EMISSION; PERIODICITIES; ACCELERATION; CORONA; ENERGY AB We analyzed two solar flares of 1992 September 5 and 6, using the high time resolution (data from BATSE/CGRO, and 100-3000 MHz radio (100 ms) dynamic spectra from PHOENIX. The broadband radio data reveal a separatrix frequency (at 620 and 750 MHz in the two flares) between normal- and reverse-drifting radio bursts, indicating a compact acceleration source where electron beams are injected in both the upward and downward direction. We find a mean injection rate of 1.2 bursts s-1 in one flare and more than 0.7 bursts s-1 in the other. From 12 broad-band, reverse-drifting radio bursts we find in five cases an unambiguous one-to-one correlation between the reverse-drifting radio bursts and hard X-ray (HXR) pulses of similar duration (400 +/- 220 ms). The high significance (15 +/- 6 sigma) of the HXR pulses and the small scatter (+/- 150 ms) in the relative timing strongly supports a close causal connection. The cross-correlation between HXR and radio pulses shows that the HXR pulses are coincident (within the instrumental time resolution) with the reverse-drifting bursts at the injection frequency (880 +/- 50 MHz), and lead the radio bursts by 270 +/- 150 ms at the highest observable frequency (1240 +/- 100 MHz). The average drift time of the downward propagating radio bursts is measured to 150 ms, corresponding to a drift rate of 2350 MHz s-1. We examined various effects to model the observed timing of radio and HXR pulses (propagation delays, radio wave growth and damping, group velocity delays, radio wave scattering, radio wave ducting, light path differences, etc.). Assuming an exciter velocity of v/c = 0.2 +/- 0.1 for the reverse-drifting radio bursts, we infer an altitude difference of H = 8000 +/- 3000 km between the injection site and the HXR source. The most likely explanation for the retarded radio emission seems to be a combination of the following two effects: (1) HXR-emitting (> 25 keV) and radio-emitting electrons have different energies (the exciter velocity of the reverse-drifting radio bursts is associated with less than or similar to 5 keV electrons), and (2) a low (marginal) growth rate for plasma emission at the second harmonics. Delay effects caused by group velocity, collisional damping, wave scattering, and wave ducting are found to be minor (< 30 ms each). C1 SWISS FED INST TECHNOL,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,COLL PK,MD 20742, USA. NR 56 TC 59 Z9 61 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 1993 VL 417 IS 2 BP 790 EP 804 DI 10.1086/173359 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MD971 UT WOS:A1993MD97100040 ER PT J AU SANDFORD, SA ALLAMANDOLA, LJ AF SANDFORD, SA ALLAMANDOLA, LJ TI CONDENSATION AND VAPORIZATION STUDIES OF CH3OH AND NH3 ICES - MAJOR IMPLICATIONS FOR ASTROCHEMISTRY SO ASTROPHYSICAL JOURNAL LA English DT Article DE DUST, EXTINCTION; MOLECULAR PROCESSES ID INFRARED SPECTRAL PROPERTIES; TIME-DEPENDENT CHEMISTRY; DENSE MOLECULAR CLOUDS; INTERSTELLAR GRAINS; EMISSION FEATURE; METHANOL; GAS; CO; ANALOGS; REGION AB In an extension of previously reported work on ices containing H2O, CO, CO2, SO2, H2S, and H-2, we present measurements of the physical and infrared spectral properties of ices containing CH3OH and NH3. The condensation and sublimation behavior of these ice systems is discussed and surface binding energies are presented for all of these molecules. The surface binding energies can be used to calculate the residence times of the molecules on grain surfaces as a function of temperature. It is demonstrated that many of the molecules used to generate radio maps of and probe conditions in dense clouds, for example CO and NH3, will be significantly depleted from the gas phase by condensation onto dust grains. Attempts to derive total column densities solely from radio maps that do not take condensation effects into account may vastly underestimate the true column densities of any given species. Simple CO condensation onto and vaporization off of grains appears to be capable of explaining the observed depletion of gas phase CO in cold, dense molecular cores. This is not the case for NH3, however, where thermal considerations alone predict that all of the NH3 should be condensed onto grains. The fact that some gas phase NH3 is observed indicates that additional desorption processes must, be involved. The surface binding energies of CH3OH, in conjunction with this molecule's observed behavior during warm up in H2O-rich ices, is shown to provide an explanation of the large excess of CH3OH seen in many warm, dense molecular cores. The near-infrared spectrum and associated integrated band strengths of CH3OH-containing ice are given, as are middle infrared absorption band strengths for both CH3OH and NH3. RP NASA, AMES RES CTR, MAIL STOP 2456, MOFFETT FIELD, CA 94035 USA. NR 66 TC 187 Z9 187 U1 1 U2 17 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 1993 VL 417 IS 2 BP 815 EP 825 DI 10.1086/173362 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MD971 UT WOS:A1993MD97100043 PM 11540092 ER PT J AU MICHALITSIANOS, AG NICHOLSBOHLIN, J BRUHWEILER, FC KAZANAS, D KONDO, Y DELAPENA, M MARAN, SP MEYLAN, T PEREZ, M THOMPSON, R AF MICHALITSIANOS, AG NICHOLSBOHLIN, J BRUHWEILER, FC KAZANAS, D KONDO, Y DELAPENA, M MARAN, SP MEYLAN, T PEREZ, M THOMPSON, R TI DETECTION OF FAR-ULTRAVIOLET HIGH-EXCITATION LINE EMISSION AND LYMAN-BETA ABSORPTION IN THE GRAVITATIONAL LENS Q0957+561 SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMOLOGY, GRAVITATIONAL LENSING; QUASARS, ABSORPTION LINES; QUASARS, EMISSION LINES; QUASARS, INDIVIDUAL (0957+561) ID GALAXY AB Test runs with a new data processing software system on archival spectra obtained by the International Ultraviolet Explorer (IUE) reveal high-excitation emission lines in the gravitationally lensed binary quasar 0957+561. The lines of O VI lambdalambda1031,1037 and S VI lambdalambda933,945 are readily seen in a single 390 minute, low-dispersion IUE exposure, when calibrated with the New Spectral Image Processing System (NEWSIPS). Co-addition of 10 exposures, as processed by NEWSIPS, followed by the application of a five-point smoothing filter, allows clear detection of the additional emission of C III lambda978, N III lambda992, S IV lambdalambda1063-1073, N II lambda1084, Fe in (UVI; lambda1125), and N V lambda1238. These identifications assume rest wavelengths consistent with the z = 1.41 redshift of the lensed quasar. In addition, we find a strong absorption that can be attributed to H I Lyman-beta lambda1017 with a redshift consistent with a previously reported damped Lyman-alpha absorption system at z = 1.3911, which is probably associated with intervening gas near the quasar (Turnshek & Bohlin 1993). Another absorption feature appears to be due to Si II lambdalambda 1190,1193 in the halo of an intervening galaxy at z = 1.38. Finally, the strong discontinuity in the continuum at the Lyman limit lambda912 is appropriate to absorption that corresponds to the Lyman-alpha and, Lyman-beta absorption line system at Z = 1.3911. These first results suggest that NEWSIPS is capable of disclosing much previously unrecognized information that is contained in the nearly 100,000 ultraviolet spectra currently in the IUE Archive, especially in regions of the spectra that are under-exposed. C1 NASA,GODDARD SPACE FLIGHT CTR,COMP SCI CORP,IUE OBSERV,GREENBELT,MD 20771. CATHOLIC UNIV AMER,DEPT PHYS,WASHINGTON,DC 20064. NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. RP MICHALITSIANOS, AG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,CODE 680,GREENBELT,MD 20771, USA. NR 25 TC 7 Z9 7 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 1993 VL 417 IS 2 BP L57 EP & DI 10.1086/187093 PN 2 PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA MD972 UT WOS:A1993MD97200001 ER PT J AU OPPENHEIMER, C ROTHERY, DA PIERI, DC ABRAMS, MJ CARRERE, V AF OPPENHEIMER, C ROTHERY, DA PIERI, DC ABRAMS, MJ CARRERE, V TI ANALYSIS OF AIRBORNE VISIBLE INFRARED IMAGING SPECTROMETER (AVIRIS) DATA OF VOLCANIC HOT-SPOTS SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID LAVA FLOW AB In July 1991, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) was flown over Mount Etna and Stromboli, Italy. At the time, magma-filled vents, of subpixel dimensions, occupied the summit craters of both volcanoes. For pixels located over these hot spots, thermal radiation dominates the sensor response between about 1.4 and 2.4 mum, the latter figure being the upper limit of spectral coverage. One thermal source within the Northeast Crater of Mount Etna is evident at wavelengths as short as 1.0 mum; despite this intensity, there is no saturation of the AVIRIS sensors because of their wide dynamic range. A curve-fitting algorithm is used to match the thermal spectra with Planck radiation models, in order to derive information on temperature distributions at the subpixel scale. Difficulties arise because the sequential readout of detector elements during scanning leads to interband spatial misregistration. Although the standard preprocessing of AVIRIS data includes a linear interpolation of adjacent pairs of cross-track pixels to compensate for the readout delay, this procedure only complicates further the extraction of subpixel resolution thermal information. Only by reconfiguring AVIRIS, such that all spectral channels are recorded simultaneously, could this problem be completely overcome. Nevertheless, by examining geometrically unprocessed spectra, and selecting from them thermal measurements in a few adjacent channels, meaningful radiometric calculations are possible in some cases. In this manner, we estimate that one of the hot spots on Stromboli was at almost-equal-to 600-degrees-C and occupied almost-equal-to 15 m2 of ground. The methodologies proposed here are applicable to any hyperspectral record of thermal emission of volcanic or other origin. C1 JET PROP LAB,PASADENA,CA 91109. RP OPPENHEIMER, C (reprint author), OPEN UNIV,DEPT EARTH SCI,MILTON KEYNES MK7 6AA,BUCKS,ENGLAND. RI Oppenheimer, Clive/G-9881-2013 OI Oppenheimer, Clive/0000-0003-4506-7260 NR 25 TC 25 Z9 25 U1 2 U2 4 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 NOV 10 PY 1993 VL 14 IS 16 BP 2919 EP 2934 PG 16 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA ML556 UT WOS:A1993ML55600003 ER PT J AU SOVERS, OJ JACOBS, CS GROSS, RS AF SOVERS, OJ JACOBS, CS GROSS, RS TI MEASURING RAPID OCEAN TIDAL EARTH ORIENTATION VARIATIONS WITH VERY LONG-BASE-LINE INTERFEROMETRY SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID INNER CORE DYNAMICS; FORCED NUTATIONS; RADIO INTERFEROMETRY; PERIODIC CHANGES; ROTATION; SYSTEM; TIDES; GEODESY; VLBI AB Ocean tidal effects on universal time and polar motion (UTPM) are investigated at four nearly diurnal (K1, P1, O1, and Q1) and four nearly semidiurnal (K2, S2, M2, and N2) frequencies by analyzing very long baseline interferometry (VLBI) data extending from 1978 to 1992. We discuss limitations of comparisons between experiment and theory for the retrograde nearly diurnal polar motion components due to their degeneracy with prograde components of the nutation model. Estimating amplitudes of contributions to the modeled VLBI observables at these eight frequencies produces a statistically highly significant improvement of 7 mm to the residuals of a fit to the observed delays. Use of such an improved UTPM model also reduces the 14-30 mm scatter of baseline lengths about a time-linear model of tectonic motion by 3-14 mm, also with high significance levels. A total of 28 UTPM ocean tidal amplitudes can be unambiguously estimated from the data, with resulting UT1 and PM magnitudes as large as 21 As and 270 microarc seconds (muas) and formal uncertainties of the order of 0.3 mus and 5 muas for UTI and PM, respectively. Empirically determined UTPM amplitudes and phases are compared to values calculated theoretically by Gross from Seiler's global ocean tide model. The discrepancy between theory and experiment is larger by a factor of 3 for UT1 amplitudes (9 mus) than for prograde PM amplitudes (42 muas). The 14-year VLBI data span strongly attenuates the influence of mismodeled effects on estimated UTPM amplitudes and phases that are not coherent with the eight frequencies of interest. Magnitudes of coherent and quasi-coherent systematic errors are quantified by means of internal consistency tests. We conclude that coherent systematic effects are many times larger than the formal uncertainties and can be as large as 4 mus for UT1 and 60 muas for polar motion. On the basis of such realistic error estimates, 22 of the 31 fitted UTPM ocean tidal amplitudes differ from zero by more than 2sigma. RP SOVERS, OJ (reprint author), JET PROP LAB, PASADENA, CA 91109 USA. NR 52 TC 34 Z9 35 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-SOL EA JI J. Geophys. Res.-Solid Earth PD NOV 10 PY 1993 VL 98 IS B11 BP 19959 EP 19971 DI 10.1029/93JB02060 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA MG708 UT WOS:A1993MG70800031 ER PT J AU LEW, JS JUANG, JN LONGMAN, RW AF LEW, JS JUANG, JN LONGMAN, RW TI COMPARISON OF SEVERAL SYSTEM-IDENTIFICATION METHODS FOR FLEXIBLE STRUCTURES SO JOURNAL OF SOUND AND VIBRATION LA English DT Article C1 NASA,LANGLEY RES CTR,SPACECRAFT DYNAM BRANCH,HAMPTON,VA 23681. COLUMBIA UNIV,DEPT MECH ENGN,NEW YORK,NY 10027. RP LEW, JS (reprint author), TENNESSEE STATE UNIV,CTR EXCELLENCE INFORMAT SYST,NASHVILLE,TN 37203, USA. NR 14 TC 31 Z9 34 U1 1 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD NOV 8 PY 1993 VL 167 IS 3 BP 461 EP 480 DI 10.1006/jsvi.1993.1348 PG 20 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA MJ536 UT WOS:A1993MJ53600006 ER PT J AU KOLB, EW TKACHEV, II AF KOLB, EW TKACHEV, II TI AXION MINICLUSTERS AND BOSE STARS SO PHYSICAL REVIEW LETTERS LA English DT Article ID INFLATION AB Evolution of inhomogeneities in the axion field around the QCD epoch is studied numerically, including for the first time important nonlinear effects. It is found that perturbations on scales corresponding to causally disconnected regions at T approximately 1 GeV can lead to very dense axion clumps, with present density rho(a) greater than or similar to 10(-8) g cm-3. This is high enough for the collisional 2a --> 2a process to lead to Bose-Einstein relaxation in the gravitationally bound clumps of axions, forming Bose stars. C1 RUSSIAN ACAD SCI,INST NUCL RES,MOSCOW 117312,RUSSIA. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP KOLB, EW (reprint author), NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. NR 16 TC 74 Z9 75 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 8 PY 1993 VL 71 IS 19 BP 3051 EP 3054 DI 10.1103/PhysRevLett.71.3051 PG 4 WC Physics, Multidisciplinary SC Physics GA MF914 UT WOS:A1993MF91400003 ER PT J AU BAME, SJ GOLDSTEIN, BE GOSLING, JT HARVEY, JW MCCOMAS, DJ NEUGEBAUER, M PHILLIPS, JL AF BAME, SJ GOLDSTEIN, BE GOSLING, JT HARVEY, JW MCCOMAS, DJ NEUGEBAUER, M PHILLIPS, JL TI ULYSSES OBSERVATIONS OF A RECURRENT HIGH-SPEED SOLAR-WIND STREAM AND THE HELIOMAGNETIC STREAMER BELT SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CORONAL STREAMERS AB Near-ecliptic solar wind observations by Ulysses on its way to the polar regions of the Sun, compared with those from IMP 8 at 1 AU, showed that high-speed streams decay and broaden with heliocentric distance from IMP 8 to Ulysses, as expected. In July 1992 while travelling south at approximately 13-degrees-S and 5.3 AU, Ulysses encountered a recurrent high-speed stream, that may also have been observed at IMP 8. The stream has been observed a total of 14 times, once in each solar rotation through June 1993 at approximately 34-degrees-S. The source of the high-speed stream is an equatorward extension of the south polar coronal hole. From July 1992 through June 1993, averages of solar wind peak speed increased while density decreased with heliographic latitude. Both the stream and a low-speed, high-density flow, presumably associated with the heliomagnetic (coronal) streamer belt encircling the heliomagnetic equator, crossed Ulysses with the solar rotation period until April 1993 when the spacecraft was at approximately 29-degrees-S heliographic latitude. After this time, as the spacecraft climbed to higher latitudes, the central portion of the streamer belt with lowest speed and highest density disappeared. Therefore, at its maximum inclination, the belt was tilted at approximately 29-degrees to the heliographic equator at this point in the solar cycle. C1 NATL OPT ASTRON OBSERV,NATL SOLAR OBSERV,TUCSON,AZ 85726. JET PROP LAB,PASADENA,CA 91109. RP BAME, SJ (reprint author), LOS ALAMOS NATL LAB,DIV SPACE SCI & TECHNOL,MS D466,LOS ALAMOS,NM 87545, USA. NR 11 TC 150 Z9 150 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 5 PY 1993 VL 20 IS 21 BP 2323 EP 2326 DI 10.1029/93GL02630 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MF829 UT WOS:A1993MF82900002 ER PT J AU SMITH, EJ NEUGEBAUER, M BALOGH, A BAME, SJ ERDOS, G FORSYTH, RJ GOLDSTEIN, BE PHILLIPS, JL TSURUTANI, BT AF SMITH, EJ NEUGEBAUER, M BALOGH, A BAME, SJ ERDOS, G FORSYTH, RJ GOLDSTEIN, BE PHILLIPS, JL TSURUTANI, BT TI DISAPPEARANCE OF THE HELIOSPHERIC SECTOR STRUCTURE AT ULYSSES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CURRENT SHEET AB In May, 1993, the heliospheric current sheet (HCS) ceased to be seen by the Ulysses spacecraft at a heliocentric latitude of approximately 30-degrees-S and distance of 4.7 AU. The disappearance of the HCS coincided with the solar wind speed remaining >560 km/s and with the disappearance of one of four interaction regions previously seen on each solar rotation. The heliographic latitude of the disappearance of die HCS at Ulysses was 11-degrees equatorward of the latitude of the magnetic neutral sheet computed at the source surface at 2.5 solar radii, and it occurred a half year earlier than predicted on the basis of the persistence of the time profile of the neutral sheet tilt from one solar cycle to the next. C1 LOS ALAMOS NATL LAB,DIV SPACE SCI & TECHNOL,LOS ALAMOS,NM 87545. UNIV LONDON IMPERIAL COLL SCI & TECHNOL,BLACKETT LAB,LONDON SW7 2B7,ENGLAND. RP SMITH, EJ (reprint author), JET PROP LAB,MS 169-506,PASADENA,CA 91109, USA. NR 16 TC 104 Z9 104 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 NOV 5 PY 1993 VL 20 IS 21 BP 2327 EP 2330 DI 10.1029/93GL02632 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MF829 UT WOS:A1993MF82900003 ER PT J AU BALOGH, A ERDOS, G FORSYTH, RJ SMITH, EJ AF BALOGH, A ERDOS, G FORSYTH, RJ SMITH, EJ TI THE EVOLUTION OF THE INTERPLANETARY SECTOR STRUCTURE IN 1992 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR AB The unique vantage point of the Ulysses spacecraft throughout 1992 and the beginning of 1993, at a close to constant heliocentric distance of about 5 AU and a slowly varying heliographic latitude from 5-degrees to 30-degrees south is used to describe and discuss the evolution of the sector structure of the interplanetary magnetic field during the declining phase of the solar cycle. From the end of 1990 to the beginning of 1992 the sector structure changed from a four sector to a two sector structure, but remained constant in solar longitude. From about June-July 1992, the structure, matching the evolution in the computed coronal magnetic fields, drifted eastwards, with a recurrence period of about 28 days. This result may indicate a slower rotation rate for the dipolar component of the solar magnetic field which becomes dominant about this time in the solar cycle. C1 JET PROP LAB,PASADENA,CA 91109. RP BALOGH, A (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. NR 9 TC 41 Z9 41 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 NOV 5 PY 1993 VL 20 IS 21 BP 2331 EP 2334 DI 10.1029/93GL02621 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MF829 UT WOS:A1993MF82900004 ER PT J AU GOSLING, JT BAME, SJ FELDMAN, WC MCCOMAS, DJ PHILLIPS, JL GOLDSTEIN, BE AF GOSLING, JT BAME, SJ FELDMAN, WC MCCOMAS, DJ PHILLIPS, JL GOLDSTEIN, BE TI COUNTERSTREAMING SUPRATHERMAL ELECTRON EVENTS UPSTREAM OF COROTATING SHOCKS IN THE SOLAR-WIND BEYOND SIMILAR-TO-2AU-ULYSSES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EARTHS BOW SHOCK; FLUX; AU AB Enhanced fluxes of suprathermal electrons are commonly observed upstream of corotating forward and reverse shocks in the solar wind at heliocentric distances beyond approximately 2 AU by the Los Alamos plasma experiment on Ulysses. The average duration of these events, which are most intense immediately upstream from the shocks and which fade with increasing distance from them, is approximately 2.4 days near 5 AU. These events are caused by the leakage of shock-heated electrons into the upstream region. The upstream regions of these shocks face back toward the Sun along the interplanetary magnetic field, so these leaked electrons commonly counterstream relative to the normal solar wind electron heat flux. The observations suggest that conservation of magnetic moment and scattering typically limit the sunward propagation of these electrons as beams to field-aligned distances of approximately 15 AU. Although it seems unlikely that these shock-associated events are an important source of counterstreaming events near 1 AU, remnants of the backstreaming beams may contribute importantly to the diffuse solar wind halo electron population there. C1 JET PROP LAB,PASADENA,CA 91109. RP GOSLING, JT (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. NR 13 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 5 PY 1993 VL 20 IS 21 BP 2335 EP 2338 DI 10.1029/93GL02489 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MF829 UT WOS:A1993MF82900005 ER PT J AU KONOPLIV, AS BORDERIES, NJ CHODAS, PW CHRISTENSEN, EJ SJOGREN, WL WILLIAMS, BG BALMINO, G BARRIOT, JP AF KONOPLIV, AS BORDERIES, NJ CHODAS, PW CHRISTENSEN, EJ SJOGREN, WL WILLIAMS, BG BALMINO, G BARRIOT, JP TI VENUS GRAVITY AND TOPOGRAPHY - 60TH DEGREE AND ORDER MODEL SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HARMONIC-ANALYSIS AB We have combined die most recent Pioneer Venus Orbiter (PVO) and Magellan (MGN) data with the earlier 1978-1982 PVO data set to obtain a new 60th degree and order spherical harmonic gravity model and a 120th degree and order spherical harmonic topography model. Free-air gravity maps are shown over regions where the most marked improvement has been obtained (Ishtar-Terra, Alpha, Bell and Artemis). Gravity versus topography relationships are presented as correlations per degree and axes orientation. C1 CTR NATL ETUD SPATIALES,RECH GEODESIE SPATIAE GRP,F-31055 TOULOUSE,FRANCE. RP KONOPLIV, AS (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 17 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 NOV 5 PY 1993 VL 20 IS 21 BP 2403 EP 2406 DI 10.1029/93GL01890 PG 4 WC Geosciences, Multidisciplinary SC Geology GA MF829 UT WOS:A1993MF82900022 ER PT J AU FENIMORE, EE EPSTEIN, RI HO, C KLEBESADEL, RW LACEY, C LAROS, JG MEIER, M STROHMAYER, T PENDLETON, G FISHMAN, G KOUVELIOTOU, C MEEGAN, C AF FENIMORE, EE EPSTEIN, RI HO, C KLEBESADEL, RW LACEY, C LAROS, JG MEIER, M STROHMAYER, T PENDLETON, G FISHMAN, G KOUVELIOTOU, C MEEGAN, C TI THE INTRINSIC LUMINOSITY OF GAMMA-RAY BURSTS AND THEIR HOST GALAXIES SO NATURE LA English DT Article ID EVOLUTION; MODELS AB THE Burst and Transient Source Experiment (BATSE) on the Compton Gamma-Ray Observatory has shown that, although gamma-ray bursts are distributed isotropically on the sky, there is an apparent dearth of weak events compared to those expected from a homogeneous distribution of sources1,2. This suggests that the bursts originate either in an extended galactic halo3 (that is, locally) or at cosmological distances4,5. The intensity distribution of the bursts can be used to constrain their source properties and spatial distribution, and here we address this question by considering the BATSE data with those from the Pioneer Venus Orbiter, correcting for the different reponse of the two instruments. We show that the composite intensity distribution can after all be fitted by a simple, homogeneous model of gamma-ray burst sources with identical intrinsic luminosities where the faintest BATSE events are at a redshift of z approximately 0.80+/-0.05. We obtain an upper limit of about -18 on the absolute magnitude of the host galaxies by assigning model-derived distances to the brightest extragalactic objects found15 within the error boxes of eight well localized gamma-ray bursts. All but the faintest active galaxies are excluded as the source of the bursts. The bursts may instead be associated with normal galaxies, but only if the host-galaxy magnitudes are close to our upper limit. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP FENIMORE, EE (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 22 TC 151 Z9 152 U1 0 U2 1 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD NOV 4 PY 1993 VL 366 IS 6450 BP 40 EP 42 DI 10.1038/366040a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA MF007 UT WOS:A1993MF00700046 ER PT J AU MAYLE, R SCHRAMM, DN TURNER, MS WILSON, JR AF MAYLE, R SCHRAMM, DN TURNER, MS WILSON, JR TI CONSTRAINTS ON DIRAC NEUTRINOS FROM SN-1987A SO PHYSICS LETTERS B LA English DT Article ID SUPERNOVA 1987A; NUCLEAR-MATTER; SN1987A; CONDENSATION; MASSES; AXIONS; BURST AB The Livermore Supernova Explosion Code was used to calculate the effect of a massive Dirac neutrino on neutrino emission from SN 1987A in a self-consistent manner. Spin-flip interactions involving neutrino-nucleon, nucleon-nucleon and pion-nucleon collisions lead to the copious emission of sterile, right-handed neutrinos and cool the core faster than the observed neutrino emission time for Dirac masses exceeding about 3 keV. These limits are compared with the previous limits of Burrows et al. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP MAYLE, R (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 32 TC 17 Z9 17 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD NOV 4 PY 1993 VL 317 IS 1-2 BP 119 EP 124 DI 10.1016/0370-2693(93)91580-G PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA MF132 UT WOS:A1993MF13200021 ER PT J AU KHOT, NS POLYAK, R SCHNEUR, R BERKE, L AF KHOT, NS POLYAK, R SCHNEUR, R BERKE, L TI APPLICATION OF NEWTON MODIFIED BARRIER METHOD TO STRUCTURAL OPTIMIZATION SO COMPUTERS & STRUCTURES LA English DT Article AB This paper presents the application of the Newton modified barrier method to obtain a minimum weight structure with constraints on displacements and minimum sizes. The solution to the problem is obtained via minimizing the modified barrier function (MBF) at each step by using the Newton method and updating Lagrange multipliers. The Lagrange multipliers are updated by using the value of the constraints at the minimum of the MBF. Three truss problems with a different number of design variables are solved. The convergence to the minimum weight design was found to be monotonic and the algorithm is potentially robust for solving problems with a large number of design variables. C1 IBM CORP,THOMAS J WATSON RES CTR,DEPT MATH SCI,YORKTOWN HTS,NY 10598. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP KHOT, NS (reprint author), FIBRA,WL,FLIGHT DYNAM DIRECTORATE,DIV STRUCT,WRIGHT PATTERSON AFB,OH 45433, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-7949 J9 COMPUT STRUCT JI Comput. Struct. PD NOV 3 PY 1993 VL 49 IS 3 BP 467 EP 472 DI 10.1016/0045-7949(93)90047-H PG 6 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA MP989 UT WOS:A1993MP98900008 ER PT J AU MARDER, SR PERRY, JW AF MARDER, SR PERRY, JW TI MOLECULAR MATERIALS FOR 2ND-ORDER NONLINEAR-OPTICAL APPLICATIONS SO ADVANCED MATERIALS LA English DT Review ID CONJUGATED ORGANIC-MOLECULES; PHOTOREFRACTIVE POLYMER; SEMIEMPIRICAL METHODS; HYPERPOLARIZABILITIES; SALTS; SUSCEPTIBILITIES; MULTILAYERS; CRYSTAL; LENGTH; DESIGN AB Strategies for the optimization of molecular second-order nonlinearities have emerged over the past few years, but significant questions still remain. This review highlights recent conceptual advances in the field of nonlinear optical molecular materials, concentrating on design criteria for the molecules themselves. e.g.. the influence of resonance structures, bond length alternation, and reduced aromaticity. and the use of organometallic compounds and octupolar molecules. Factors affecting the properties of bulk materials composed of such molecules are also discussed. C1 CALTECH,BECKMAN INST,CTR MOLEC MAT RESOURCE,PASADENA,CA 91125. RP MARDER, SR (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Perry, Joseph/B-7191-2011 OI Perry, Joseph/0000-0003-1101-7337 NR 89 TC 155 Z9 156 U1 2 U2 18 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 NOV PY 1993 VL 5 IS 11 BP 804 EP 815 DI 10.1002/adma.19930051104 PG 12 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 MH430 UT WOS:A1993MH43000003 ER PT J AU JACOBS, CS SOVERS, OJ WILLIAMS, JG STANDISH, EM AF JACOBS, CS SOVERS, OJ WILLIAMS, JG STANDISH, EM TI THE EXTRAGALACTIC AND SOLAR-SYSTEM CELESTIAL FRAMES - ACCURACY, STABILITY, AND INTERCONNECTION SO ADVANCES IN SPACE RESEARCH LA English DT Article ID OPTICAL REFERENCE FRAME; RADIO-SOURCE; JPLS DE-200; POSITIONS; VLBI; EPHEMERIS; EARTH AB Reference frames determined from measurements of extragalactic and solar system objects are used in interplanetary navigation, earth orientation measurements, geodesy, and astrometry. The extragalactic frame is derived solely from Very Long Baseline Interferometric (VLBI) measurements of compact radio sources, while the solar system frame is derived from a variety of range measurements to the inner planets and the moon. We present evidence that, within the spans of presently available observations, each frame exhibits approximately one milliarcsecond (mas) internal precision and is characterized by coordinate drifts which are uncertain by < 1 mas/yr. Next we discuss the connection between these two frames, reviewing several methods that have been used to link the two frames with 5-10 mas uncertainty, and examine prospects for future improvements in interconnection accuracy. RP JACOBS, CS (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 38 TC 7 Z9 7 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 J9 ADV SPACE RES JI Adv. Space Res. PD NOV PY 1993 VL 13 IS 11 BP 161 EP 174 DI 10.1016/0273-1177(93)90219-2 PG 14 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA ML875 UT WOS:A1993ML87500025 ER PT J AU DICKEY, JO AF DICKEY, JO TI HIGH TIME RESOLUTION MEASUREMENTS OF EARTH ROTATION SO ADVANCES IN SPACE RESEARCH LA English DT Article ID GLOBAL POSITIONING SYSTEM; ANGULAR-MOMENTUM; POLE POSITION; TIDES AB High time resolution measurements of Earth rotation and atmospheric angular momentum (AAM) and their interpretation have been proposed as a major research thrust for the 1990s. An extensive campaign, SEARCH'92, is now under way to obtain these measurements utilizing all space geodetic techniques and to collect the best available complementary geophysical, oceanographic and atmospheric data. This paper discusses its motivation and scientific benefits and reviews international cooperation in several measurement campaigns with particular emphasis on SEARCH'92. Recent analysis results are highlighted. RP DICKEY, JO (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 36 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 J9 ADV SPACE RES JI Adv. Space Res. PD NOV PY 1993 VL 13 IS 11 BP 185 EP 196 DI 10.1016/0273-1177(93)90221-V PG 12 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA ML875 UT WOS:A1993ML87500027 ER PT J AU NELSON, DA AF NELSON, DA TI THE CASE FOR SHUTTLE-II SO AEROSPACE AMERICA LA English DT Article RP NELSON, DA (reprint author), NASA,WASHINGTON,DC 20546, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0740-722X J9 AEROSPACE AM JI Aerosp. Am. PD NOV PY 1993 VL 31 IS 11 BP 24 EP 27 PG 4 WC Engineering, Aerospace SC Engineering GA ME954 UT WOS:A1993ME95400006 ER PT J AU ANDERSON, JL AF ANDERSON, JL TI BACK FROM THE FUTURE SO AEROSPACE AMERICA LA English DT Article RP ANDERSON, JL (reprint author), NASA,OFF ADV CONCEPTS & TECHNOL,WASHINGTON,DC 20546, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0740-722X J9 AEROSPACE AM JI Aerosp. Am. PD NOV PY 1993 VL 31 IS 11 BP 32 EP 36 PG 5 WC Engineering, Aerospace SC Engineering GA ME954 UT WOS:A1993ME95400008 ER PT J AU FRENDI, A ROBINSON, J AF FRENDI, A ROBINSON, J TI EFFECT OF ACOUSTIC COUPLING ON RANDOM AND HARMONIC PLATE VIBRATIONS SO AIAA JOURNAL LA English DT Article ID EXCITATION; SYSTEM; CHAOS AB The effect of acoustic coupling on random and harmonic plate vibrations is studied using two numerical models. In the coupled model, the plate response is obtained by integration of the nonlinear plate equation coupled with the nonlinear Euler equations for the surrounding acoustic fluid. In the uncoupled model, the nonlinear plate equation with an equivalent linear viscous damping term is integrated to obtain the response of the plate subject to the same excitation field. For a low-level, narrow-band excitation, the two models predict the same plate response spectra. As the excitation level is increased, the response power spectrum predicted by the uncoupled model becomes broader and more shifted toward the high frequencies than that obtained by the coupled model. In addition, the difference in response between the coupled and uncoupled models at high frequencies becomes larger. When a high intensity harmonic excitation is used, causing a nonlinear plate response, both models predict the same frequency content of the response. However, the levels of the harmonics and subharmonics are higher for the uncoupled model. Comparisons to earlier experimental and numerical results show that acoustic coupling has a significant effect on the plate response at high excitation levels. Its absence in previous models may explain in part the discrepancy between predicted and measured responses. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23681. RP FRENDI, A (reprint author), ANALYT SERV & MAT INC,HAMPTON,VA 23666, USA. NR 29 TC 11 Z9 11 U1 1 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 1993 VL 31 IS 11 BP 1992 EP 1997 DI 10.2514/3.11882 PG 6 WC Engineering, Aerospace SC Engineering GA MF793 UT WOS:A1993MF79300004 ER PT J AU OTUGEN, MV ANNEN, KD SEASHOLTZ, RG AF OTUGEN, MV ANNEN, KD SEASHOLTZ, RG TI GAS TEMPERATURE-MEASUREMENTS USING A DUAL-LINE DETECTION RAYLEIGH-SCATTERING TECHNIQUE SO AIAA JOURNAL LA English DT Article ID LIGHT-SCATTERING; PREMIXED FLAMES; DENSITY; JET AB A new laser-induced Rayleigh scattering method is presented for the improved temperature diagnostics of gas flows. In the present technique, the two lines of a copper vapor laser are used to obtain spatially resolved temperature. A single set of optics is used to form the optical probe and to collect the signal simultaneously from both the 510 nm and the 578 nm lines. The dual-line detection allows for the determination and removal of surface-scattered laser light from the Rayleigh signal, thereby improving the applicability of Rayleigh scattering to near-wall flows with a high degree of glare. An optical system using the dual-line detection technique was built, calibrated, and tested in a hot air jet under various levels of background contamination. The results indicate that accurate temperature measurements are possible even when the laser-line background intensity, captured by the collecting optics, is twice that of the Rayleigh signal. C1 AERODYNE RES INC,DEPT CHEM & ENVIRONM PHYS,BILLERICA,MA 01821. NASA,LEWIS RES CTR,OPT MEASUREMENT SYST BRANCH,CLEVELAND,OH 44135. RP OTUGEN, MV (reprint author), POLYTECH INST NEW YORK,DEPT ENGN,BROOKLYN,NY 11201, USA. NR 18 TC 4 Z9 4 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 NOV PY 1993 VL 31 IS 11 BP 2098 EP 2104 DI 10.2514/3.11896 PG 7 WC Engineering, Aerospace SC Engineering GA MF793 UT WOS:A1993MF79300018 ER PT J AU ADMIRE, JR TINKER, ML IVEY, EW AF ADMIRE, JR TINKER, ML IVEY, EW TI MASS-ADDITIVE MODAL TEST METHOD FOR VERIFICATION OF CONSTRAINED STRUCTURAL MODELS SO AIAA JOURNAL LA English DT Article AB A method for deriving constrained or fixed-base modes and frequencies from free-free modes of a structure with mass-loaded boundaries is developed. Problems associated with design and development of test fixtures can be avoided with such an approach. The analytical methodology presented is used to assess applicability of the mass-additive method for three types of structures and to determine the accuracy of derived constrained modes and frequencies. Results show that mass loading of the boundaries enables local interface modes to be measured within a desired frequency bandwidth, thus allowing constrained modes to be derived with considerably fewer free-free modes than for unloaded boundaries. Good convergence was obtained for a simple beam and a truss-like Shuttle payload, both of which had well-spaced modes and stiff interface support structures. Slow convergence was obtained for a space station module prototype, a shell-like structure having high modal density. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,DIV STRUCT ANAL,PAYLOAD DYNAM & LOADS BRANCH,HUNTSVILLE,AL 35812. RP ADMIRE, JR (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,DIV STRUCT ANAL,HUNTSVILLE,AL 35812, USA. NR 9 TC 14 Z9 14 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 NOV PY 1993 VL 31 IS 11 BP 2148 EP 2153 DI 10.2514/3.11903 PG 6 WC Engineering, Aerospace SC Engineering GA MF793 UT WOS:A1993MF79300025 ER PT J AU STARLINGER, A THOMAS, DJ DUFFY, SF GYEKENYESI, JP AF STARLINGER, A THOMAS, DJ DUFFY, SF GYEKENYESI, JP TI RELIABILITY-ANALYSIS OF LAMINATED CERAMIC-MATRIX COMPOSITES USING SHELL SUBELEMENT TECHNIQUES SO AIAA JOURNAL LA English DT Note C1 SUNY BUFFALO,BUFFALO,NY 14260. CLEVELAND STATE UNIV,DEPT CIVIL ENGN,CLEVELAND,OH 44115. NASA,LEWIS RES CTR,DEPT ENGN,CLEVELAND,OH 44135. RP STARLINGER, A (reprint author), NASA,LEWIS RES CTR,MRC,CLEVELAND,OH 44135, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD NOV PY 1993 VL 31 IS 11 BP 2181 EP 2183 DI 10.2514/3.49127 PG 3 WC Engineering, Aerospace SC Engineering GA MF793 UT WOS:A1993MF79300032 ER PT J AU HUANG, PG BRADSHAW, P COAKLEY, TJ AF HUANG, PG BRADSHAW, P COAKLEY, TJ TI SKIN FRICTION AND VELOCITY PROFILE FAMILY FOR COMPRESSIBLE TURBULENT BOUNDARY-LAYERS (VOL 31, PG 1600, 1993) SO AIAA JOURNAL LA English DT Correction, Addition C1 STANFORD UNIV,STANFORD,CA 94305. NASA,AMES RES CTR,MOFFETT FIELD,CA 94305. RP HUANG, PG (reprint author), ELORET INST,PALO ALTO,CA 94303, USA. NR 1 TC 1 Z9 1 U1 1 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 1993 VL 31 IS 11 BP 2192 EP 2192 DI 10.2514/3.49132 PG 1 WC Engineering, Aerospace SC Engineering GA MF793 UT WOS:A1993MF79300036 ER PT J AU NARAYANSWAMI, N HORSTMAN, CC KNIGHT, DD AF NARAYANSWAMI, N HORSTMAN, CC KNIGHT, DD TI COMPUTATION OF CROSSING SHOCK TURBULENT BOUNDARY-LAYER INTERACTION AT MACH 8.3 (VOL 31, PG 1369, 1993) SO AIAA JOURNAL LA English DT Correction, Addition C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP NARAYANSWAMI, N (reprint author), RUTGERS UNIV,PISCATAWAY,NJ 08855, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD NOV PY 1993 VL 31 IS 11 BP 2192 EP 2192 PG 1 WC Engineering, Aerospace SC Engineering GA MF793 UT WOS:A1993MF79300035 ER PT J AU FINN, CK WAHLBERG, B YDSTIE, BE AF FINN, CK WAHLBERG, B YDSTIE, BE TI CONSTRAINED PREDICTIVE CONTROL USING ORTHOGONAL EXPANSIONS SO AICHE JOURNAL LA English DT Article ID DYNAMIC MATRIX CONTROL; IDENTIFICATION; ERROR AB In this article, we approximate bounded operators by orthogonal expansion. The rate of convergence depends on the choice of basis functions. Markov-Laguerre functions give rapid convergence for open-loop stable systems with long delay. The Markov-Kautz model can be used for lightly damped systems, and a more general orthogonal expansion is developed for modeling multivariable systems with widely scattered poles. The finite impulse response model is a special case of these models. A-priori knowledge about dominant time constants, time delay and oscillatory modes is used to reduce the model complexity and to improve conditioning of the parameter estimation algorithm. Algorithms for predictive control are developed, as well as conditions for constraint compatibility, closed-loop stability and constraint satisfaction for the ideal case. An H(infinity)-like design technique proposed guarantees robust stability in the presence of input constraints; output constraints may give ''chatter.'' A chatter-free algorithm is proposed. C1 CARNEGIE MELLON UNIV,DEPT CHEM ENGN,PITTSBURGH,PA 15213. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. ROYAL INST TECHNOL,DEPT AUTOMAT CONTROL,S-10044 STOCKHOLM 70,SWEDEN. NR 32 TC 18 Z9 19 U1 0 U2 2 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0001-1541 J9 AICHE J JI AICHE J. PD NOV PY 1993 VL 39 IS 11 BP 1810 EP 1826 DI 10.1002/aic.690391109 PG 17 WC Engineering, Chemical SC Engineering GA MD366 UT WOS:A1993MD36600008 ER PT J AU CHUNG, GY MCCOY, BJ SMITH, JM CAGLIOSTRO, DE AF CHUNG, GY MCCOY, BJ SMITH, JM CAGLIOSTRO, DE TI CHEMICAL-VAPOR INFILTRATION - DISPERSED AND GRADED DEPOSITIONS FOR CERAMIC COMPOSITES SO AICHE JOURNAL LA English DT Article ID SOLID MATRIX DEPOSITION; TITANIUM DIBORIDE AB A structured-geometry model for dispersed and graded deposits was developed for chemical vapor infiltration of multiply-woven substrates of carbon filters. A n earlier model was modified to allow for two reactants in the feed. The model predicts gas-phase concentration profiles in the voids of substrates and deposition amounts of two reactants as a function of time and location. Results are shown for feeding reactant gases simultaneously for dispersed deposition and periodically for the study of the graded deposition for a typical substrate. The variation in relative contents of reactants in the feed with time shows how the composition of the deposit varies. Porosities and changes of dimensions with time everywhere in the substrate are also predicted. This is an advantage of the structured-geometry model vs. a simplified homogeneous geometry for the substrate. Such a simplification may preclude predicting failure, such as delamination, which would require a local description of the composite structure. Sensitivity to input parameters such as temperature, pressure, and reactant feed concentration is discussed, and two substrate geometries are compared. The behavior of the system is predicted to be dominated by the times to fill gaps between filaments at the ply surfaces and the outermost space between plies. Furthermore, faster kinetics and slower reactant diffusion favor deposition of one material near the surface of a ply or the matrix and the other near the center of the ply or matrix. By manipulating feed rates of reactants, uniformity of material and overall porosity of the composites are predicted to be enhanced. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. UNIV CALIF DAVIS,DEPT CHEM ENGN,DAVIS,CA 95616. NR 21 TC 13 Z9 13 U1 0 U2 2 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0001-1541 J9 AICHE J JI AICHE J. PD NOV PY 1993 VL 39 IS 11 BP 1834 EP 1846 DI 10.1002/aic.690391111 PG 13 WC Engineering, Chemical SC Engineering GA MD366 UT WOS:A1993MD36600010 ER PT J AU LANE, HW LEBLANC, AD PUTCHA, L WHITSON, PA AF LANE, HW LEBLANC, AD PUTCHA, L WHITSON, PA TI NUTRITION AND HUMAN PHYSIOLOGICAL ADAPTATIONS TO SPACE-FLIGHT SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Article DE SPACE FLIGHT; NUTRITIONAL REQUIREMENTS; CARDIOVASCULAR SYSTEM; RENAL SYSTEM; LIVER; BONE; HEMATOLOGY ID BED REST; MUSCLE; BONE; SPACEFLIGHT; RAT AB Space flight provides a model for the study of healthy individuals undergoing unique stresses. This review focuses on how physiological adaptations to weightlessness may affect nutrient and food requirements in space. These adaptations include reductions in body water and plasma volume, which affect the renal and cardiovascular systems and thereby fluid and electrolyte requirements. Changes in muscle mass and function may affect requirements for energy, protein, and amino acids. Changes in bone mass lead to increased urinary calcium concentrations, which may increase the risk of forming renal stones. Space motion sickness may influence putative changes in gastrointestinal-hepatic function; neurosensory alterations may affect smell and taste. Some or all of these effects may be ameliorated through the use of specially designed dietary countermeasures. C1 KRUG LIFE SCI,HOUSTON,TX. RP LANE, HW (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,BIOMED OPERAT & RES BRANCH,MAIL CODE SD4,HOUSTON,TX 77058, USA. NR 34 TC 23 Z9 25 U1 0 U2 2 PU AMER SOC CLINICAL NUTRITION 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 1993 VL 58 IS 5 BP 583 EP 588 PG 6 WC Nutrition & Dietetics SC Nutrition & Dietetics GA ME259 UT WOS:A1993ME25900001 PM 8237860 ER PT J AU VIKRAM, CS WITHEROW, WK TROLINGER, JD AF VIKRAM, CS WITHEROW, WK TROLINGER, JD TI ALGORITHM FOR PHASE-DIFFERENCE MEASUREMENT IN PHASE-SHIFTING INTERFEROMETRY SO APPLIED OPTICS LA English DT Article ID FRINGES AB A phase-shifting algorithm is proposed and experimentally demonstrated for phase-difference analysis. The method involves only three steps, the original and two equal in amount but unknown phase steps for each stage. Only six frames of data are thus sufficient for the phase-difference analysis between two stages. Real-time holographic interferometry with a concentration change in a sugar-water solution in a test cell is presented for experimental verification. C1 NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, SPACE SCI LAB, HUNTSVILLE, AL 35812 USA. METROLASER, IRVINE, CA 92714 USA. RP VIKRAM, CS (reprint author), UNIV ALABAMA, CTR APPL OPT, HUNTSVILLE, AL 35899 USA. NR 18 TC 17 Z9 18 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 1993 VL 32 IS 31 BP 6250 EP 6252 PG 3 WC Optics SC Optics GA MF623 UT WOS:A1993MF62300007 PM 20856457 ER PT J AU VANTOMME, A NICOLET, MA LONG, RG MAHAN, JE POOL, FS AF VANTOMME, A NICOLET, MA LONG, RG MAHAN, JE POOL, FS TI REACTIVE DEPOSITION EPITAXY OF CRSI2 SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 5TH EUROPEAN WORKSHOP ON REFRACTORY METALS AND SILICIDES CY MAR 29-31, 1993 CL SINT MICHIELSGESTEL, NETHERLANDS SP BANDGAP, FISONS INSTRUMENTS, FDN FUNDAMENTAL RES MATTER, LEYBOLD, STICHTING PHYS ID GROWTH AB CrSi2 layers were synthesized by deposition of Cr onto a Si(111) substrate kept at 450 degrees C, allowing full reaction of the metal with silicon. In situ RHEED patterns confirmed the formation of the CrSi2 phase with matching faces CrSi2(0001)/Si(111) and of the type A azimuthal orientation CrSi2[10(1) over bar 0] parallel to Si[110]. The epitaxy of the initially textured films is enhanced by post-deposition annealing up to 1200 degrees C. With high-temperature treatment, the initially nearly continuous silicide layers break up into CrSi2 islands, the height and diameter of which increases with the annealing temperature. Backscattering spectra confirm the presence of exposed silicon, by indicating that the apparent stoichiometry of the film is Si rich CrSix (x > 2). In the best case, a minimum channeling yield lower than 30% was found in the Cr signal of the backscattering spectrum. As far as we know, this is the first evidence of channeling in CrSi2 films grown by any technique, other than ion beam synthesis. Both the areal fraction of exposed Si and the crystalline quality of the silicide islands depend strongly on the annealing temperature and the amount of Cr deposited. From perpendicular strain measurements, the critical thickness for pseudomorphic growth is estimated to be the equivalent of 20 Angstrom of deposited Cr. C1 COLORADO STATE UNIV,FT COLLINS,CO 80523. CALTECH 302306,JET PROPULS LAB,PASADENA,CA 91109. RP VANTOMME, A (reprint author), CALTECH 11681,PASADENA,CA 91125, USA. NR 10 TC 18 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD NOV PY 1993 VL 73 BP 146 EP 152 DI 10.1016/0169-4332(93)90159-9 PG 7 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA MH329 UT WOS:A1993MH32900023 ER EF