FN Thomson Reuters Web of Science™ VR 1.0 PT S AU Hartley, FT Malek, CK Nguyen, S AF Hartley, FT Malek, CK Nguyen, S BE Vladimirsky, Y TI X-ray exposures of electro-deposited photoresist for conformal lithography on corrugated surfaces SO EMERGING LITHOGRAPHIC TECHNOLOGIES II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Emerging Lithographic Technologies II CY FEB 23-25, 1998 CL SANTA CLARA, CA SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, SEMATECH DE electro-deposited resist; X-ray lithography; deep depth-of-field AB Proximity printing using synchrotron X-ray lithography provides high resolution pattern transfer with large depth of field, low diffraction effects and no reflection from the substrate. Electro-plating of photo-resist allows deposition of thin, uniform films over geometrically complex and topographically diverse, electrically conductive surfaces. Two electrodeposited photoresists produced by Shipley, EAGLE 2100 ED negative tone and PEPR 2400 positive tone resist, have been tested with X-rays demonstrating micron pattern transfer over depths-of-field in fractions of millimeters. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hartley, FT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2776-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3331 BP 555 EP 558 DI 10.1117/12.309615 PG 4 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL37W UT WOS:000075329300062 ER PT J AU Miller, RS Bellan, J AF Miller, RS Bellan, J TI Numerical simulation of vortex pyrolysis reactors for condensable tar production from biomass SO ENERGY & FUELS LA English DT Article ID TURBULENCE CLOSURE; PREDICTION; MODELS; FLOWS AB A numerical study is performed in order to evaluate the performance and optimal operating conditions of vortex pyrolysis reactors used for condensable tar production from biomass. A detailed mathematical model of porous biomass particle pyrolysis is coupled with a compressible Reynolds stress transport model for the turbulent reactor swirling now. An initial evaluation of particle dimensionality effects is made through comparisons of single-(1D) and multi-dimensional particle simulations and reveals that the 1D particle model results in conservative estimates for total pyrolysis conversion times and tar collection. The observed deviations are due predominantly to geometry effects while directional effects from thermal conductivity and permeability variations are relatively small. Rapid ablative particle heating rates are attributed to a mechanical fragmentation of the biomass particles that is modeled using a critical porosity for matrix breakup. Optimal thermal conditions for tar production are observed for 900 K. Effects of biomass identity, particle size distribution, and reactor geometry and scale are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bellan, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 24 TC 17 Z9 17 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD JAN-FEB PY 1998 VL 12 IS 1 BP 25 EP 40 DI 10.1021/ef970088a PG 16 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA YR751 UT WOS:000071526600005 ER PT J AU Vassiliadis, D Kourtidis, K Poulida, G AF Vassiliadis, D Kourtidis, K Poulida, G TI The potential of statistical state space models in urban ozone forecasting SO ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH LA English DT Article DE ozone forecasts, accurate short-term predictions; state space models, ozone forecasts; urban ozone forecasts AB State space models for tropospheric urban ozone prediction are introduced and compared with linear regression models. The linear and non-linear state space models make accurate shortterm predictions of the ozone dynamics. The average prediction error one hour in advance is 7 mu g/m(3) and increases logarithmically with time until it reaches 26 mu g/m(3) after 30 days. For a given sequence of solar radiation inputs, predictions converge exponentially with a time scale of 8 hours, so that the model is insensitive to perturbations of more than 150 mu g/m(3) O-3. The slow increase of the prediction error in addition to the uniqueness of the prediction are encouraging for applications of state space models in forecasting ozone levers when coupled with a model that predicts total radiation. Since a radiation prediction model will be more accurate during cloud-free conditions, in addition to the fact that the state space models perform better during the summer months, state space models are suitable for applications in sunny environments. C1 Aristotelian Univ Salonika, Dept Phys, Lab Atmospher Phys, GR-54006 Salonika, Greece. NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Frederick Res Ctr, CY-1303 Nicosia, Cyprus. RP Kourtidis, K (reprint author), Aristotelian Univ Salonika, Dept Phys, Lab Atmospher Phys, Campus Box 149, GR-54006 Salonika, Greece. NR 14 TC 1 Z9 1 U1 0 U2 0 PU ECOMED PUBLISHERS PI LANDSBERG PA RUDOLF-DIESEL-STR 3, D-86899 LANDSBERG, GERMANY SN 0944-1344 J9 ENVIRON SCI POLLUT R JI Environ. Sci. Pollut. Res. PY 1998 VL 5 IS 1 BP 7 EP 11 DI 10.1007/BF02986367 PG 5 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZL152 UT WOS:000073404000004 PM 19002621 ER PT S AU Oliker, L Biswas, R Gabow, HN AF Oliker, L Biswas, R Gabow, HN BE Pritchard, D Reeve, J TI Performance analysis and portability of the PLUM load balancing system SO EURO-PAR '98 PARALLEL PROCESSING SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 4th International Euro-Par Conference on Parallel Processing CY SEP 01-04, 1998 CL SOUTHAMPTON, ENGLAND SP Univ Southampton, Dept Electron & Comp Sci, Concurrent Computat Grp ID ALGORITHMS AB The ability to dynamically adapt an unstructured mesh is a powerful tool for solving computational problems with evolving physical features; however, an efficient parallel implementation is rather difficult. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive numerical computations in a message-passing environment. PLUM requires that all data be globally redistributed after each mesh adaption to achieve load balance. We present an algorithm for minimizing this remapping overhead by guaranteeing an optimal processor reassignment. We also show that the data redistribution cost can be significantly reduced by applying our heuristic processor reassignment algorithm to the default mapping of the parallel partitioner. Portability is examined by comparing performance on a SP3, an Origin2000, and a T3E, Results show that PLUM can be successfully ported to different platforms without any code modifications. C1 NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, MRJ, Moffett Field, CA 94035 USA. Univ Colorado, CS Dept, Boulder, CO 80309 USA. RP Oliker, L (reprint author), NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64952-2 J9 LECT NOTES COMPUT SC PY 1998 VL 1470 BP 307 EP 317 PG 11 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BN65M UT WOS:000082482800033 ER PT S AU Chapman, B Mehrotra, P AF Chapman, B Mehrotra, P BE Pritchard, D Reeve, J TI OpenMP and HPF: Integrating two paradigms SO EURO-PAR '98 PARALLEL PROCESSING SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 4th International Euro-Par Conference on Parallel Processing CY SEP 01-04, 1998 CL SOUTHAMPTON, ENGLAND SP Univ Southampton, Dept Electron & Comp Sci, Concurrent Computat Grp AB High Performance Fortran is a portable, high-level extension of Fortran for creating data parallel applications on non-uniform memory access machines. Recently, a set of language extensions to Fortran and C based upon a fork-join model of parallel execution was proposed; called OpenMP, it aims to provide a portable shared memory programming interface for shared memory and low latency systems. Both paradigms offer useful features for programming high performance computing systems configured with a mixture of shared and distributed memory. In this paper, we consider how these programming models may be combined to write programs which exploit the full capabilities of such systems. C1 Univ Vienna, VCPC, Vienna, Austria. NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. RP Chapman, B (reprint author), Univ Vienna, VCPC, Waehringer Guertel 18, Vienna, Austria. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64952-2 J9 LECT NOTES COMPUT SC PY 1998 VL 1470 BP 650 EP 658 PG 9 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BN65M UT WOS:000082482800078 ER PT S AU Larruquert, JI Keski-Kuha, RAM AF Larruquert, JI Keski-Kuha, RAM BE Siegmund, OHW Gummin, MA TI Multilayer coatings with high reflectance in the EUV SO EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy IX CY JUL 22-24, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE multilayer coatings; extreme ultraviolet; far ultraviolet; reflectance; thin films AB Multilayer coatings with a small number of layers were designed to give an increase in normal incidence reflectance in the extreme ultraviolet over that of the available single layer coatings. Multilayer coatings based on Al, MgF2 and SiC or B4C showed higher reflectance than single layers of SiC and B4C in the spectral region from 57.9 nm to 121.6 nm H Lyman alpha line and above. The major increase in reflectance was obtained at wavelengths close to 121.6 MI. Reflectance degraded slightly over time in the same way as single layer coatings. preliminary results have recently been obtained with a second design based on a superposition of films of increasing refractive index from outermost to innermost layer, e. g. with multilayer coatings of SiC on B4C on diamond-like carbon (DLC). A combination of both designs, with multilayer coatings of the type Al/ MgF2/ DLC/ B4C/ SIC, results in further increase in the EUV reflectance, although their stability has not been determined yet. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Larruquert, JI (reprint author), NASA, Goddard Space Flight Ctr, Code 551, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2900-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3445 BP 86 EP 95 DI 10.1117/12.330330 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BM19Y UT WOS:000078010600008 ER PT S AU Lohn, JD Colombano, SP AF Lohn, JD Colombano, SP BE Sipper, M Mange, D PerezUribe, A TI Automated analog circuit synthesis using a linear representation SO EVOLVABLE SYSTEMS: FROM BIOLOGY TO HARDWARE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 2nd International Conference on Evolvable Systems - From Biology to Hardware (ICES 98) CY SEP 23-25, 1998 CL LAUSANNE, SWITZERLAND SP Int Latsis Fdn, Swiss Nat Sci Fdn, Swiss Fed Inst Technol AB We present a method of evolving analog electronic circuits using a linear representation and a simple unfolding technique. While this representation excludes a large number of circuit topologies, it is capable of constructing many of the useful topologies seen in hand-designed circuits. Our system allows circuit size, circuit topology, and device values to be evolved. Using a parallel genetic algorithm we present initial results of our system as applied to two analog filter design problems. The modest computational requirements of our system suggest that the ability to evolve complex analog circuit representations in software is becoming more approachable on a single engineering workstation. C1 NASA, Ames Res Ctr, Caelum Res Corp, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Computat Sci Div, Moffett Field, CA 94035 USA. RP Lohn, JD (reprint author), NASA, Ames Res Ctr, Caelum Res Corp, Mail Stop 269-1, Moffett Field, CA 94035 USA. NR 14 TC 31 Z9 31 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64954-9 J9 LECT NOTES COMPUT SC PY 1998 VL 1478 BP 125 EP 133 PG 9 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BN66C UT WOS:000082521300013 ER PT S AU Stoica, A Fukunaga, A Hayworth, K Salazar-Lazaro, C AF Stoica, A Fukunaga, A Hayworth, K Salazar-Lazaro, C BE Sipper, M Mange, D PerezUribe, A TI Evolvable hardware for space applications SO EVOLVABLE SYSTEMS: FROM BIOLOGY TO HARDWARE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 2nd International Conference on Evolvable Systems - From Biology to Hardware (ICES 98) CY SEP 23-25, 1998 CL LAUSANNE, SWITZERLAND SP Int Latsis Fdn, Swiss Nat Sci Fdn, Swiss Fed Inst Technol AB This paper focuses on characteristics and applications of evolvable hardware (EHW) to space systems. The motivation for looking at EHW originates in the need for more autonomous adaptive space systems. The idea of evolvable hardware becomes attractive for long missions when the hardware looses optimality, and uploading new software only partly alleviates the problem if the computing hardware becomes obsolete or the sensing hardware faces needs outside original design specifications. The pager reports the first intrinsic evolution on an analog ASIC (a custom analog neural chip), suggests evolution of dynamical systems in state-space representations, and demonstrates evolution of compression algorithms with results better than the best-known compression algorithms. C1 CALTECH, Jet Prop Lab, Ctr Integrated Space Microsyst, Pasadena, CA 91109 USA. RP Stoica, A (reprint author), CALTECH, Jet Prop Lab, Ctr Integrated Space Microsyst, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 14 TC 7 Z9 7 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64954-9 J9 LECT NOTES COMPUT SC PY 1998 VL 1478 BP 166 EP 173 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BN66C UT WOS:000082521300017 ER PT S AU Hayworth, K AF Hayworth, K BE Sipper, M Mange, D PerezUribe, A TI The "modeling clay" approach to bio-inspired electronic hardware SO EVOLVABLE SYSTEMS: FROM BIOLOGY TO HARDWARE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 2nd International Conference on Evolvable Systems - From Biology to Hardware (ICES 98) CY SEP 23-25, 1998 CL LAUSANNE, SWITZERLAND SP Int Latsis Fdn, Swiss Nat Sci Fdn, Swiss Fed Inst Technol AB The field of evolvable hardware or bio-inspired hardware holds the promise of automatically engineering complex electronic systems that remain adaptive during use. A growing number of experiments along these lines have been performed recently, mostly using off-the-shelf hardware or straightforward extensions of building blocks used by human engineers [1] [2]. In this paper we use the POE (Phylogeny Ontogeny Epigenesis) framework of bio-inspired hardware systems [3] and restrict evolutionary search and development considerations to pure hill-climbing search only, in order to develop some theory around evolution of electronic circuits. From this theory a new analog re-configurable hardware architecture is proposed for use in evolvable hardware. The hardware is a context switchable analog computer which can implement any general non-linear dynamic system on the level of the vector field representation. The optimization algorithm is a bio-inspired "molding" of the state-space description of the system. We call this novel hardware/optimization algorithm platform the "modeling clay" approach to bio-inspired electronic hardware. C1 CALTECH, Jet Prop Lab, Ctr Integrated Space Microsyst, Pasadena, CA 91109 USA. RP Hayworth, K (reprint author), CALTECH, Jet Prop Lab, Ctr Integrated Space Microsyst, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64954-9 J9 LECT NOTES COMPUT SC PY 1998 VL 1478 BP 248 EP 255 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BN66C UT WOS:000082521300025 ER PT B AU McKay, CP AF McKay, CP BE ChelaFlores, J Raulin, F TI The search for extraterrestrial biochemistry on Mars and Europa SO EXOBIOLOGY: MATTER, ENERGY, AND INFORMATION IN THE ORIGIN AND EVOLUTION OF LIFE IN THE UNIVERSE LA English DT Proceedings Paper CT 50th Trieste Conference on Chemical Evolution - an Abdus Salam Memorial CY SEP 22-26, 1997 CL TRIESTE, ITALY SP Int Ctr Theoret Phys, Int Ctr Genet Engn & Biotechnol, Commiss European Communities, European Commiss DGXII, CNR, UNESCO, European Space Agcy, NASA, Weizmann Inst Genome Project, Univ Paris VII, Univ Paris XII, Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Assicurazioni Gen, Univ Studi Trieste, Dipartimento Biol AB There is, from a biochemical perspective, only one type of life on Earth. To understand life as a general phenomenon it is essential to consider other types of biochemistry. In this context, fossils are not sufficient, because they do not retain information about the biochemistry of an organism. Based on current knowledge, two worlds in our solar system hold the prospect for finding a biochemical system different from the Earth; Mars and Europa. On Mars intact organisms may be preserved in the ancient permafrost, while on Europa organisms from a possible ocean may be present near cracks in the icy surface. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP McKay, CP (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-5172-X PY 1998 BP 219 EP 227 PG 9 WC Biology; Multidisciplinary Sciences SC Life Sciences & Biomedicine - Other Topics; Science & Technology - Other Topics GA BL92S UT WOS:000077171800030 ER PT S AU Chettri, S Murakami, Y Nagano, I Garegnani, J AF Chettri, S Murakami, Y Nagano, I Garegnani, J BE Selander, JM TI Comparing the computational complexity of the PNN, the PDM and the MMNN (M(2)N(2)) SO EXPLOITING NEW IMAGE SOURCES AND SENSORS, 26TH AIPR WORKSHOP SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 26th AIPR Workshop on Exploiting New Image Sources and Sensors CY OCT 15-17, 1997 CL WASHINGTON, D.C. SP Soc Photo Opt Instrumentat Engineers, Appl Imagery Pattern Recognit Execut Comm DE neural networks; Probabilistic Neural Networks (PNN); Polynomial Discriminant Method (PDM); mixture models; expectation-maximization algorithm; mixture model neural network ((MN2)-N-2); computational complexity AB In classification, the goal is to assign an input vector to a discrete number of output classes. Classifier design has a long history and they have been put to a large number of uses [1]. In this paper we continue the task of categorizing classifiers by their computational complexity as begun in [3]. In particular, we derive analytical formulas for the number of arithmetic operations in the probabilistic neural network (PNN) and its polynomial expansion, also known as the Polynomial Discriminant Method (PDM) and the mixture model neural network ((MN2)-N-2). In addition we perform tests of the classification accuracy of the PDM with respect to the PNN and the (MN2)-N-2 find that all three are close in accuracy. Based on this research we now have the ability to choose one or the other based on the computational complexity, the memory requirements and the size of the training set. This is a great advantage in an operational environment. We also discuss the extension of such methods to hyperspectral data and find that only the (MN2)-N-2 is suitable for application to such data. C1 NASA, Goddard Space Flight Ctr, GST, Greenbelt, MD 20771 USA. RP Chettri, S (reprint author), NASA, Goddard Space Flight Ctr, GST, Code 935, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2678-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3240 BP 126 EP 132 DI 10.1117/12.300049 PG 7 WC Engineering, Biomedical; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BK57V UT WOS:000072611900014 ER PT J AU Bergin Millar Hatchell Irvine Schutte Palumbo Black van Dishoeck Thaddeus Ehrenfreund Chakarov Trakhtenberg McCoustra Kaiser Field Smith Herbst Millar Zare Papoular Ali Speck, AK Schlemmer Roueff Yates Sarre Clary Williams Vidali Brechignac AF Bergin Millar Hatchell Irvine Schutte Palumbo Black van Dishoeck Thaddeus Ehrenfreund Chakarov Trakhtenberg McCoustra Kaiser Field Smith Herbst Millar Zare Papoular Ali Speck, AK Schlemmer Roueff Yates Sarre Clary Williams Vidali Brechignac TI General discussion SO FARADAY DISCUSSIONS LA English DT Editorial Material ID DENSE MOLECULAR CLOUDS; CARBONYL SULFIDE OCS; PROTOSTAR GL-2136; ICE ANALOGS; INTERSTELLAR; METEORITES; METHANOL; HYDROGEN; GRAINS; OXYGEN C1 Harvard Univ, Cambridge, MA 02138 USA. Univ Manchester, Manchester M60 1QD, Lancs, England. Univ Massachusetts, Amherst, MA 01003 USA. Leiden Univ, NL-2300 RA Leiden, Netherlands. Osserv Astrofis Catania, I-95125 Catania, Italy. Chalmers, Gothenburg, Sweden. Weizmann Inst Sci, IL-76100 Rehovot, Israel. Univ Nottingham, Nottingham NG7 2RD, England. Acad Sinica, Taipei, Taiwan. Univ Aarhus, DK-8000 Aarhus C, Denmark. Ohio State Univ, Columbus, OH 43210 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. UCL, London WC1E 6BT, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. Tech Univ Chemnitz, Chemnitz, Germany. Observ Paris, Paris, France. Univ Hertfordshire, Hatfield AL10 9AB, Herts, England. Univ Rennes 1, F-35014 Rennes, France. Stanford Univ, Stanford, CA 94305 USA. Syracuse Univ, Syracuse, NY 13244 USA. Univ Paris 11, Orsay, France. RP Harvard Univ, Cambridge, MA 02138 USA. OI McCoustra, Martin/0000-0002-5716-110X NR 54 TC 0 Z9 0 U1 0 U2 3 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-6640 EI 1364-5498 J9 FARADAY DISCUSS JI Faraday Discuss. PY 1998 VL 109 BP 83 EP 108 PG 26 WC Chemistry, Physical SC Chemistry GA 127MB UT WOS:000076353800007 ER PT J AU Sorokin Ubachs Sarre Glownia Schutte Maier Thaddeus Somerville Krelowski Halasinski Lynas-Gray Snow Zacs Schmidt Glinski Ehrenfreund Brechignac Heyl Irvine Herbst Takahashi Papoular Webster Ohishi Irvine Palumbo Herbst Markwick Chastaing James Sims Smith Kaiser Clary Terzieva Costes Naulin Casavecchia AF Sorokin Ubachs Sarre Glownia Schutte Maier Thaddeus Somerville Krelowski Halasinski Lynas-Gray Snow Zacs Schmidt Glinski Ehrenfreund Brechignac Heyl Irvine Herbst Takahashi Papoular Webster Ohishi Irvine Palumbo Herbst Markwick Chastaing James Sims Smith Kaiser Clary Terzieva Costes Naulin Casavecchia TI General discussion SO FARADAY DISCUSSIONS LA English DT Editorial Material ID DIFFUSE INTERSTELLAR BANDS; POLYCYCLIC AROMATIC-HYDROCARBONS; NEUTRAL-NEUTRAL REACTION; INFRARED-EMISSION BANDS; GAS-PHASE; AB-INITIO; DIPOLE-MOMENT; ATOMIC CARBON; MOLECULES; RESOLUTION C1 IBM Corp, Div Res, Armonk, NY 10504 USA. Leiden Univ, NL-2300 RA Leiden, Netherlands. UCL, London WC1E 6BT, England. Univ Colorado, Boulder, CO 80309 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Univ Nottingham, Nottingham NG7 2RD, England. Univ Manchester, Manchester M60 1QD, Lancs, England. Osserv Astrofis Catania, I-95125 Catania, Italy. Natl Astron Observ Japan, Mizusawa, Iwate, Japan. Univ Oxford, Oxford OX1 2JD, England. Torun Ctr Astron, Torun, Poland. Univ Basel, CH-4003 Basel, Switzerland. Acad Sinica, Taipei, Taiwan. Ohio State Univ, Columbus, OH 43210 USA. Harvard Univ, Cambridge, MA 02138 USA. Vrije Univ, Amsterdam, Netherlands. NASA, Ames Res Ctr, Moffett Field, CA USA. Tennessee Technol Univ, Cookeville, TN 38505 USA. Univ Paris 11, Orsay, France. Univ Gottingen, D-3400 Gottingen, Germany. Univ Massachusetts, Amherst, MA 01003 USA. Univ Bordeaux 1, F-33405 Talence, France. Univ Perugia, I-06100 Perugia, Italy. RP IBM Corp, Div Res, Armonk, NY 10504 USA. NR 95 TC 0 Z9 0 U1 1 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-6640 EI 1364-5498 J9 FARADAY DISCUSS JI Faraday Discuss. PY 1998 VL 109 BP 217 EP 256 PG 40 WC Chemistry, Physical SC Chemistry GA 127MB UT WOS:000076353800014 ER PT J AU Schwenke, DW AF Schwenke, DW TI Opacity of TiO from a coupled electronic state calculation parametrized by ab initio and experimental data SO FARADAY DISCUSSIONS LA English DT Article; Proceedings Paper CT General Discussion on Chemistry and Physics of Molecules and Grains in Space CY APR 15-17, 1998 CL UNIV NOTTINGHAM, NOTTINGHAM, ENGLAND HO UNIV NOTTINGHAM ID ROTATIONAL ANALYSIS; TITANIUM MONOXIDE; SPECTROSCOPY; BAND; RESOLUTION; SYSTEM AB We have carried out calculations of re-vibrational energy levels of the 13 lowest electronic states of TiO. The dominant couplings between the various states are included, with the coupling parameters and potential parameters optimized to match experimental energy levels. We have also performed ab initio electronic structure calculations of the spin-orbit and rotation-orbit couplings, to verify that the physical results are obtained from the optimization. Our wavefunctions were used to predict the intensities of both well characterized and unobserved forbidden bands. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Schwenke, DW (reprint author), NASA, Ames Res Ctr, M-S-230-3, Moffett Field, CA 94035 USA. RI schwenke, david/I-3564-2013 NR 21 TC 96 Z9 96 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0301-7249 J9 FARADAY DISCUSS JI Faraday Discuss. PY 1998 VL 109 BP 321 EP 334 DI 10.1039/a800070k PG 14 WC Chemistry, Physical SC Chemistry GA 127MB UT WOS:000076353800019 ER PT J AU Crovisier Aikawa Rowe Irvine Herbst Ehrenfreund Krelowski Snow Gerlich McCall Schlemmer Tennyson Millar Sarre Leach Glinski Ubachs Black Thaddeus Field Fossey Ali Sedlmayr Lobel Schutte Richards Casassus Bernath Schwenke Costes Naulin Couch Pavlenko Vidali Bernstein Papoular McCoustra Gordon Palumbo Joblin Stone Hudgins Gingell Sorokin Glownia AF Crovisier Aikawa Rowe Irvine Herbst Ehrenfreund Krelowski Snow Gerlich McCall Schlemmer Tennyson Millar Sarre Leach Glinski Ubachs Black Thaddeus Field Fossey Ali Sedlmayr Lobel Schutte Richards Casassus Bernath Schwenke Costes Naulin Couch Pavlenko Vidali Bernstein Papoular McCoustra Gordon Palumbo Joblin Stone Hudgins Gingell Sorokin Glownia TI General discussion SO FARADAY DISCUSSIONS LA English DT Editorial Material ID POLYCYCLIC AROMATIC-HYDROCARBONS; DIFFUSE INTERSTELLAR-MEDIUM; HIGH-RESOLUTION OBSERVATIONS; INFRARED-EMISSION FEATURES; DUST GRAINS; IR EMISSION; DISSOCIATIVE RECOMBINATION; HOMOGENEOUS NUCLEATION; ABSORPTION FEATURES; POTENTIAL SURFACES C1 Observ Paris, Meudon, France. Natl Astron Observ Japan, Mitaka, Tokyo, Japan. Univ Rennes 1, F-35014 Rennes, France. Univ Massachusetts, Amherst, MA 01003 USA. Ohio State Univ, Columbus, OH 43210 USA. Leiden Univ, NL-2300 RA Leiden, Netherlands. Torun Ctr Astron, Torun, Poland. Univ Colorado, Boulder, CO 80309 USA. Tech Univ Chemnitz, Chemnitz, Germany. Univ Chicago, Chicago, IL 60637 USA. UCL, London WC1E 6BT, England. Univ Manchester, Manchester M60 1QD, Lancs, England. Univ Nottingham, Nottingham NG7 2RD, England. Tennessee Technol Univ, Cookeville, TN 38505 USA. Vrije Univ Amsterdam, Amsterdam, Netherlands. Chalmers, S-41296 Gothenburg, Sweden. Harvard Univ, Cambridge, MA 02138 USA. Univ Aarhus, DK-8000 Aarhus C, Denmark. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Tech Univ Berlin, D-1000 Berlin, Germany. Armagh Observ, Armagh BT61 9DG, North Ireland. Univ Manchester, Manchester M13 9PL, Lancs, England. Univ Oxford, Oxford OX1 2JD, England. Univ Brussels, Brussels, Belgium. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Bordeaux 1, F-33405 Talence, France. Ukrainian Acad Sci, UA-252601 Kiev, Ukraine. Syracuse Univ, Syracuse, NY 13244 USA. CEA, Gif Sur Yvette, France. Louisiana State Univ, Baton Rouge, LA 70803 USA. Osserv Astrofis Catania, I-95125 Catania, Italy. CNRS, F-75700 Paris, France. IBM Corp, Div Res, Armonk, NY 10504 USA. RP Observ Paris, Meudon, France. NR 144 TC 0 Z9 0 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-6640 EI 1364-5498 J9 FARADAY DISCUSS JI Faraday Discuss. PY 1998 VL 109 BP 361 EP 401 PG 41 WC Chemistry, Physical SC Chemistry GA 127MB UT WOS:000076353800022 ER PT J AU Irvine Zare Clemett Pillinger Sedlmayr Ehrenfreund Sarre Leach Speck, AK Papoular Crovisier Vigasin van Dishoeck Bernath Owen Kaiser Palumbo Schutte Aikawa Nuth, J Gounelle van Winkel Smith Vidali Liu Herbst Stancil Millar Hatchell Thaddeus Bernstein AF Irvine Zare Clemett Pillinger Sedlmayr Ehrenfreund Sarre Leach Speck, AK Papoular Crovisier Vigasin van Dishoeck Bernath Owen Kaiser Palumbo Schutte Aikawa Nuth, J Gounelle van Winkel Smith Vidali Liu Herbst Stancil Millar Hatchell Thaddeus Bernstein TI General discussion SO FARADAY DISCUSSIONS LA English DT Editorial Material ID ASTROPHYSICAL ICE ANALOGS; MAIN-SEQUENCE STARS; INFRARED-SPECTROSCOPY; ABSORPTION FEATURES; MICRON ABSORPTION; RED RECTANGLE; DUST SHELLS; HALE-BOPP; X-RAY; SPECTRA C1 Univ Massachusetts, Amherst, MA 01003 USA. Stanford Univ, Stanford, CA 94305 USA. Open Univ, Milton Keynes MK7 6AA, Bucks, England. Tech Univ Berlin, D-1000 Berlin, Germany. Leiden Univ, NL-2300 RA Leiden, Netherlands. Observ Paris, Meudon, France. UCL, London WC1E 6BT, England. CEA, Gif Sur Yvette, France. Russian Acad Sci, Moscow 117901, Russia. Univ Brussels, Brussels, Belgium. Univ Hawaii, Honolulu, HI 96822 USA. Acad Sinica, Taipei 115, Taiwan. Osserv Astrofis Catania, I-95125 Catania, Italy. Univ Nottingham, Nottingham NG7 2RD, England. Natl Astron Observ, Mitaka, Tokyo, Japan. Univ Paris 11, Orsay, France. Katholieke Univ Leuven, Louvain, Belgium. Syracuse Univ, Syracuse, NY 13244 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Univ Illinois, Urbana, IL 61801 USA. Ohio State Univ, Columbus, OH 43210 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Univ Manchester, Manchester M60 1QD, Lancs, England. Harvard Univ, Cambridge, MA 02138 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Univ Massachusetts, Amherst, MA 01003 USA. NR 80 TC 0 Z9 0 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-6640 EI 1364-5498 J9 FARADAY DISCUSS JI Faraday Discuss. PY 1998 VL 109 BP 493 EP 516 PG 24 WC Chemistry, Physical SC Chemistry GA 127MB UT WOS:000076353800029 ER PT J AU Dausch, DE AF Dausch, DE TI Asymmetric 90 degrees domain switching in rainbow actuators SO FERROELECTRICS LA English DT Article DE rainbow actuators; piezoelectric properties; domain switching; asymmetry; internal stress AB Asymmetry in the domain switching properties of Rainbow actuators with respect to positive and negative electric field was investigated and compared with the more symmetric properties of bulk ceramic materials. The electromechanical displacement and polarization hysteresis loops were found to be asymmetric in Rainbows. Peak-to-peak displacements in Rainbows poled at +25 kV/cm increased steadily from 88 to 450 mu m with increasing fields of +/-5 to +/-24 kV/cm. Rainbows poled at -25 kV/cm possessed a local minimum in displacement of 95 mu m at 13 kV/cm (near the coercive field) indicating a change in effective slope of the displacement versus field loop. Additionally, Rainbows possessed lower +E-C (coercive field) and higher +P-R (remanent polarization). It was found through X-ray diffraction of the tetragonal peak splitting in these materials that Rainbows exhibited enhanced 90 degrees reorientation of a-domains to c-domain alignment with positive applied electric field than with negative field. Bulk ceramic properties were consistent for both positive and negative applied fields. A mechanism for 90 degrees domain switching is discussed. C1 NASA, Langley Res Ctr, Natl Res Council, Hampton, VA 23681 USA. RP Dausch, DE (reprint author), NASA, Langley Res Ctr, Natl Res Council, Hampton, VA 23681 USA. NR 8 TC 8 Z9 8 U1 0 U2 2 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 0015-0193 J9 FERROELECTRICS JI Ferroelectrics PY 1998 VL 210 IS 1-4 BP 31 EP 45 DI 10.1080/00150199808229911 PG 15 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZU173 UT WOS:000074169600003 ER PT B AU Williams, BC Millar, W AF Williams, BC Millar, W GP AMER ASSOC ARTIFICIAL INTELLIGENCE AMER ASSOC ARTIFICIAL INTELLIGENCE TI Decompositional, model-based learning and its analogy to diagnosis SO FIFTEENTH NATIONAL CONFERENCE ON ARTIFICIAL INTELLIGENCE (AAAI-98) AND TENTH CONFERENCE ON INNOVATIVE APPLICATIONS OF ARTIFICAL INTELLIGENCE (IAAI-98) - PROCEEDINGS LA English DT Proceedings Paper CT 15th National Conference on Artificial Intelligence (AAAI 98) / 10th Conference on Innovative Applications of Artificial Intelligence (IAAI 98) CY JUL 26-30, 1998 CL MADISON, WI SP Amer Assoc Artificial Intelligence, ACM, SIGART, Defense Adv Res Projects Agcy, Microsoft Corp, USN, Off Naval Res, NASA, Ames Res Ctr, Natl Sci Fdn AB A new generation of sensor rich, massively distributed autonomous system is being developed, such as smart buildings and reconfigurable factories. To achieve high performance these systems will need to accurately model themselves and their environment from sensor information. Accomplishing this on a grand scale requires automating the art of large-scale modeling. To this end we have developed decompositional, model-based learning (DML). DML takes a parameterized model and sensed variables as input, decomposes it, and synthesizes a coordinated sequence of "simplest" estimation tasks. The method exploits a rich analogy between parameter estimation and consistency-based diagnosis. Moriarty, an implementation of DML, has been applied to thermal modeling of a smart building, demonstrating a significant improvement in learning rate. C1 NASA, Ames Res Ctr, Moffett Field, CA 94305 USA. RP Williams, BC (reprint author), NASA, Ames Res Ctr, MS 269-2, Moffett Field, CA 94305 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELLIGENCE PI MENLO PK PA 445 BURGESS DR, MENLO PK, CA 94025 USA BN 0-262-51098-7 PY 1998 BP 197 EP 204 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BL71Z UT WOS:000076427500027 ER PT B AU Clancy, DJ Kuipers, BJ AF Clancy, DJ Kuipers, BJ GP AMER ASSOC ARTIFICIAL INTELLIGENCE AMER ASSOC ARTIFICIAL INTELLIGENCE TI Qualitative simulation as a temporally-extended constraint satisfaction problem SO FIFTEENTH NATIONAL CONFERENCE ON ARTIFICIAL INTELLIGENCE (AAAI-98) AND TENTH CONFERENCE ON INNOVATIVE APPLICATIONS OF ARTIFICAL INTELLIGENCE (IAAI-98) - PROCEEDINGS LA English DT Proceedings Paper CT 15th National Conference on Artificial Intelligence (AAAI 98) / 10th Conference on Innovative Applications of Artificial Intelligence (IAAI 98) CY JUL 26-30, 1998 CL MADISON, WI SP Amer Assoc Artificial Intelligence, ACM, SIGART, Defense Adv Res Projects Agcy, Microsoft Corp, USN, Off Naval Res, NASA, Ames Res Ctr, Natl Sci Fdn AB Traditionally, constraint satisfaction problems (CSPs) are characterized using a finite set of constraints expressed within a common, shared constraint language. When reasoning across time, however, it is possible to express both temporal and state-based constraints represented within multiple constraint languages. Qualitative simulation provides an instance of this class of CSP in which, traditionally, all solutions to the CSP are computed. In this paper, we formally describe this class of temporally-extended CSPs and situate qualitative simulation within this description. This is followed by a description of the DecSIM algorithm which is used to incrementally generate all possible solutions to a temporally-extended CSP. DecSIM combines problem decomposition, a tree-clustering algorithm and ideas similar to directed are-consistency to exploit structure and causality within a qualitative model resulting in an exponential speed-up in simulation time when compared to existing techniques. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Clancy, DJ (reprint author), NASA, Ames Res Ctr, MS 269-3, Moffett Field, CA 94035 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELLIGENCE PI MENLO PK PA 445 BURGESS DR, MENLO PK, CA 94025 USA BN 0-262-51098-7 PY 1998 BP 240 EP 247 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BL71Z UT WOS:000076427500033 ER PT B AU Smith, DE Weld, DS AF Smith, DE Weld, DS GP AMER ASSOC ARTIFICIAL INTELLIGENCE AMER ASSOC ARTIFICIAL INTELLIGENCE TI Conformant graphplan SO FIFTEENTH NATIONAL CONFERENCE ON ARTIFICIAL INTELLIGENCE (AAAI-98) AND TENTH CONFERENCE ON INNOVATIVE APPLICATIONS OF ARTIFICAL INTELLIGENCE (IAAI-98) - PROCEEDINGS LA English DT Proceedings Paper CT 15th National Conference on Artificial Intelligence (AAAI 98) / 10th Conference on Innovative Applications of Artificial Intelligence (IAAI 98) CY JUL 26-30, 1998 CL MADISON, WI SP Amer Assoc Artificial Intelligence, ACM, SIGART, Defense Adv Res Projects Agcy, Microsoft Corp, USN, Off Naval Res, NASA, Ames Res Ctr, Natl Sci Fdn AB Planning under uncertainty is a difficult task. If sensory information is available, it is possible to do contingency planning - that is, develop plans where certain branches are executed conditionally, based on the outcome of sensory actions. However, even without sensory information, it is often possible to develop useful plans that succeed no matter which of the allowed states the world is actually in. We refer to this type of planning as conformant planning. Few conformant planners have been built, partly because conformant planning requires the ability to reason about disjunction. In this paper we describe Conformant Graphplan (CGP), a Graphplan-based planner that develops sound (non-contingent) plans when faced with uncertainty in the initial conditions and in the outcome of actions. The basic idea is to develop separate plan graphs for each possible world. This requires some subtle changes to both the graph expansion and solution extraction phases of Graphplan. In particular, the solution extraction phase must consider the unexpected side effects of actions in other possible worlds, and must confront any undesirable effects. We show that CGP performs significantly better than two previous (probabilistic) conformant planners. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Smith, DE (reprint author), NASA, Ames Res Ctr, Mail Stop 269-2, Moffett Field, CA 94035 USA. NR 0 TC 41 Z9 48 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELLIGENCE PI MENLO PK PA 445 BURGESS DR, MENLO PK, CA 94025 USA BN 0-262-51098-7 PY 1998 BP 889 EP 896 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BL71Z UT WOS:000076427500127 ER PT B AU Freed, M AF Freed, M GP AMER ASSOC ARTIFICIAL INTELLIGENCE AMER ASSOC ARTIFICIAL INTELLIGENCE TI Managing multiple tasks in complex, dynamic environments SO FIFTEENTH NATIONAL CONFERENCE ON ARTIFICIAL INTELLIGENCE (AAAI-98) AND TENTH CONFERENCE ON INNOVATIVE APPLICATIONS OF ARTIFICAL INTELLIGENCE (IAAI-98) - PROCEEDINGS LA English DT Proceedings Paper CT 15th National Conference on Artificial Intelligence (AAAI 98) / 10th Conference on Innovative Applications of Artificial Intelligence (IAAI 98) CY JUL 26-30, 1998 CL MADISON, WI SP Amer Assoc Artificial Intelligence, ACM, SIGART, Defense Adv Res Projects Agcy, Microsoft Corp, USN, Off Naval Res, NASA, Ames Res Ctr, Natl Sci Fdn AB Sketchy planners are designed to achieve goals in realistically complex, time-pressured, and uncertain task environments. However, the ability to manage multiple potentially interacting tasks in such environments, requires extensions to the functionality these systems. typically provide. This paper identifies; a number of factors affecting how interacting tasks, should be prioritized, interrupted, and resumed, and then describes a sketchy planner called APEX that takes account of these factors when managing multiple tasks. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Freed, M (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 13 Z9 13 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELLIGENCE PI MENLO PK PA 445 BURGESS DR, MENLO PK, CA 94025 USA BN 0-262-51098-7 PY 1998 BP 921 EP 927 PG 7 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BL71Z UT WOS:000076427500131 ER PT B AU Fisher, F Chien, S Lo, E Greeley, R AF Fisher, F Chien, S Lo, E Greeley, R GP AMER ASSOC ARTIFICIAL INTELLIGENCE AMER ASSOC ARTIFICIAL INTELLIGENCE TI Using artificial intelligence planning to automate SAR image processing for scientific data analysis SO FIFTEENTH NATIONAL CONFERENCE ON ARTIFICIAL INTELLIGENCE (AAAI-98) AND TENTH CONFERENCE ON INNOVATIVE APPLICATIONS OF ARTIFICAL INTELLIGENCE (IAAI-98) - PROCEEDINGS LA English DT Proceedings Paper CT 15th National Conference on Artificial Intelligence (AAAI 98) / 10th Conference on Innovative Applications of Artificial Intelligence (IAAI 98) CY JUL 26-30, 1998 CL MADISON, WI SP Amer Assoc Artificial Intelligence, ACM, SIGART, Defense Adv Res Projects Agcy, Microsoft Corp, USN, Off Naval Res, NASA, Ames Res Ctr, Natl Sci Fdn AB In recent times, improvements in imaging technology have made available an incredible array of information in image format. While powerful and sophisticated image processing software tools are available to prepare and analyze the data, these tools are complex and cumbersome, requiring significant expertise to properly operate. Thus, in order to extract (e.g., mine or analyze) useful information from the data, a user tin our case a scientist) often must possess both significant science and image processing expertise. This paper describes the use of AI planning techniques to represent scientific, image processing, and software tool knowledge to automate elements of science data preparation and analysis of synthetic aperture radar (SAR) imagery for planetary geology. In particular, we describe the Automated SAR Image Processing system (ASIP) which is currently in use by the Dept. of Geology at ASU supporting aeolian science analysis of synthetic aperture radar images. ASIP reduces the number of manual inputs in science product generation by 10-fold, decreases the CPU time to produce images by 30%, and allows scientists to directly produce certain science products. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fisher, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 525-3660, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER ASSOC ARTIFICIAL INTELLIGENCE PI MENLO PK PA 445 BURGESS DR, MENLO PK, CA 94025 USA BN 0-262-51098-7 PY 1998 BP 1027 EP 1031 PG 5 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BL71Z UT WOS:000076427500146 ER PT B AU Schreckenghost, D Ryan, D Thronesbery, C Bonasso, P Poirot, D AF Schreckenghost, D Ryan, D Thronesbery, C Bonasso, P Poirot, D GP AMER ASSOC ARTIFICIAL INTELLIGENCE AMER ASSOC ARTIFICIAL INTELLIGENCE TI Intelligent control of life support systems for space habitats SO FIFTEENTH NATIONAL CONFERENCE ON ARTIFICIAL INTELLIGENCE (AAAI-98) AND TENTH CONFERENCE ON INNOVATIVE APPLICATIONS OF ARTIFICAL INTELLIGENCE (IAAI-98) - PROCEEDINGS LA English DT Proceedings Paper CT 15th National Conference on Artificial Intelligence (AAAI 98) / 10th Conference on Innovative Applications of Artificial Intelligence (IAAI 98) CY JUL 26-30, 1998 CL MADISON, WI SP Amer Assoc Artificial Intelligence, ACM, SIGART, Defense Adv Res Projects Agcy, Microsoft Corp, USN, Off Naval Res, NASA, Ames Res Ctr, Natl Sci Fdn AB The Interchamber Monitoring and Control (IMC) system is semi-autonomous, intelligent software that controls life support systems designed for recycling air in remote space habitats. The IMC system was developed using the 3T autonomous control architecture. This architecture integrates traditional control with reactive task sequencing and deliberative planning technology. The IMC system was used during the Phase III test of NASA's Lunar/Mars Life Support Test Program(LMLSTP). For this test, four crew members lived in a closed habitat for 91 days. The objective of using an intelligent control system was to reduce the need for crew involvement in nominal control of life support by automating control operations. Prior to this test, manually intensive traditional process control software had been used to control LMLSTP life support systems. It is impractical and inefficient for crew at a remote site to continuously monitor day-to-day operation of life support systems. Our intelligent control software autonomously handles nominal and expected anomalous situations. The crew only intervenes in exceptional or novel situations. During the Phase III test we demonstrated the viability of using intelligent control for such automation. C1 NASA, Lyndon B Johnson Space Ctr, ER, Texas Robot & Automat Ctr, Houston, TX 77058 USA. RP Schreckenghost, D (reprint author), NASA, Lyndon B Johnson Space Ctr, ER, Texas Robot & Automat Ctr, Houston, TX 77058 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELLIGENCE PI MENLO PK PA 445 BURGESS DR, MENLO PK, CA 94025 USA BN 0-262-51098-7 PY 1998 BP 1140 EP 1145 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BL71Z UT WOS:000076427500162 ER PT B AU Sterling, T AF Sterling, T BE Johnsson, L Kostuck, R Schenfeld, E Snir, M TI Opportunities for optical communications in petaflops-scale computing SO FIFTH INTERNATIONAL CONFERENCE ON MASSIVELY PARALLEL PROCESSING, PROCEEDINGS LA English DT Proceedings Paper CT 5th International Conference on Massively Parallel Processing CY JUN 15-17, 1998 CL LAS VEGAS, NV SP IEEE Comp Soc, Tech Comm Comp Architecture C1 CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91125 USA. RP Sterling, T (reprint author), CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8572-7 PY 1998 BP 64 EP 65 DI 10.1109/MPPOI.1998.682128 PG 2 WC Computer Science, Software Engineering; Computer Science, Theory & Methods; Optics SC Computer Science; Optics GA BL32Y UT WOS:000075178100009 ER PT B AU Bergman, LA Yeh, C Morookian, J AF Bergman, LA Yeh, C Morookian, J BE Johnsson, L Kostuck, R Schenfeld, E Snir, M TI Towards the realization of multi-km x gbytes/sec bit-parallel WDM single fiber computer links SO FIFTH INTERNATIONAL CONFERENCE ON MASSIVELY PARALLEL PROCESSING, PROCEEDINGS LA English DT Proceedings Paper CT 5th International Conference on Massively Parallel Processing CY JUN 15-17, 1998 CL LAS VEGAS, NV SP IEEE Comp Soc, Tech Comm Comp Architecture AB At the MPPOI '96 and '97 Conferences, a new way to dynamically control in-flight pulses by a shepherd pulse to enhance rime-alignment of co-propagating pulses in a bir-parallel WDM system for a single-mode fiber was discussed and the first experimental evidence that this pulse shepherding effect carl be observed in a commercially available DS (dispersion-shifted) fiber was also presented. Here, we shall discuss the initial results towards the realization of a multi-km x gbytes/sec bit-parallel WDM single fiber link. The distance-speed product of this single fiber link is more than several orders of magnitude higher than that of a fiber ribbon link. The design of a 12 bit-parallel channels WDM system operating at I Gbit/sec per channel rate will first be presented. Experimental results for a two channel system operating at that rate will then be given. Also, new computer simulation results on how a large amplitude shepherd pulse may induce pulse compression on all the co-propagating data pulses, thereby improving the shaping of these pulses for a WDM system, will be presented and discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bergman, LA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8572-7 PY 1998 BP 218 EP 223 DI 10.1109/MPPOI.1998.682146 PG 6 WC Computer Science, Software Engineering; Computer Science, Theory & Methods; Optics SC Computer Science; Optics GA BL32Y UT WOS:000075178100026 ER PT B AU Frumkin, M Hood, R Lopez, L AF Frumkin, M Hood, R Lopez, L GP IEEE TI Trace-driven debugging of message passing programs SO FIRST MERGED INTERNATIONAL PARALLEL PROCESSING SYMPOSIUM & SYMPOSIUM ON PARALLEL AND DISTRIBUTED PROCESSING LA English DT Proceedings Paper CT 1st Merged International Parallel Processing Symposium/Symposium on Parallel and Distributed Processing (IPPS/SPDP 1998) CY MAR 30-APR 03, 1998 CL ORLANDO, FL SP IEEE Comp Soc Tech Comm Parallel Proc, ACM SIGARCH AB In this paper we report on features added to a parallel debugger to simplify the debugging of message passing programs. These features include replay, setting consistent breakpoints based on interprocess event causality, a parallel undo operation, and communication supervision. These features all use trace information collected during the execution of the program being debugged. We used a number of different instrumentation techniques to collect traces. We also implemented trace displays using two different trace visualization systems. The implementation was tested on an SGI Power Challenge cluster and a network of SGI workstations. C1 NASA, Ames Res Ctr, NAS Syst Div, MRJ Technol Solut, Moffett Field, CA 94035 USA. RP Frumkin, M (reprint author), NASA, Ames Res Ctr, NAS Syst Div, MRJ Technol Solut, M-S T27A-1, Moffett Field, CA 94035 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8403-8 PY 1998 BP 753 EP 762 DI 10.1109/IPPS.1998.670012 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BK74S UT WOS:000073316800118 ER PT S AU Minello, TJ AF Minello, TJ BE Benaka, LR TI Nekton densities in shallow estuarine habitats of Texas and Louisiana and the identification of essential fish habitat SO FISH HABITAT: ESSENTIAL FISH HABITAT AND REHABILITATION SE AMERICAN FISHERIES SOCIETY SYMPOSIUM LA English DT Review CT Sea Grant Symposium on Fish Habitat - Essential Fish Habitat and Rehabilitation at the 1998 Annual Meeting of the American-Fisheries-Society CY AUG 26-27, 1998 CL HARTFORD, CT SP Amer Fisheries Soc ID PENAEUS-ESCULENTUS HASWELL; CRABS CALLINECTES-SAPIDUS; LOBSTERS PANULIRUS-ARGUS; DRUM SCIAENOPS-OCELLATUS; CARIBBEAN SPINY LOBSTER; JUVENILE BLUE CRABS; GULF-OF-MEXICO; BROWN SHRIMP; SALT-MARSH; DECAPOD CRUSTACEANS AB The Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens Act) of 1996 requires the identification of essential fish habitat (EFH) for fishery species under federal fishery management plans (FMPs). As defined in the Magnuson-Stevens Act, EFH includes waters and substrate necessary for spawning, breeding, feeding, or growth to maturity. Without EFH, fishery species will be unable to maintain the productivity needed to support a sustainable fishery or contribute ecologically to aquatic ecosystems. The highly productive estuaries in the northern Gulf of Mexico contain many habitat types that are potentially essential for species under FMPs such as brown shrimp Penaeus aztecus, white shrimp P. setiferus, pink shrimp P. duorarum, gulf stone crab Menippe adina, red drum Sciaenops ocellatus, gray snapper Lutjanus griseus, and bluefish Pomatomus saliatrix; these species spend their juvenile life stages in estuarine nurseries. Estuarine habitats also may be important for prey required as forage by managed species and for other fishery species not under FMPs. My objective in this paper was to summarize information on densities of juvenile fishery species and other animals (all generally <100 mm total length) in shallow-water estuarine areas of Texas and Louisiana. I attempted to identify where these species live (delineate their habitat) and to analyze density patterns within habitats that would be useful in distinguishing EFH. My analysis was restricted to data collected with enclosure sampling techniques because these techniques have been shown to provide comparable density estimates among highly diverse shallow-water areas. Habitat types evaluated included Spartina alterniflora marsh edge (SAME), mixed-vegetation marsh edge, inner marsh (>5 m from open water), submerged aquatic vegetation (SAV), oyster reefs, and shallow nonvegetated bottom (SNB). Data also were categorized by season, salinity regime, estuarine system, and year of collection. Mean densities among habitat types frequently varied in relation to salinity regime, but overall, SAME was used most by brown shrimp, white shrimp, blue crab Callinectes sapidus, spotted seatrout Cynoscion nebulosus, and southern flounder Paralichthys lethostigma. Highest densities of pink shrimp, red drum, and sand seatrout Cynoscion arenarius were found in SAV. Stone crabs had highest mean densities on oyster reefs and gulf menhaden Brevoortia patronus on SNB. Each of the six habitat types examined ranked first or second in use by at least one of these fishery species. Thus, all of these habitat types are likely essential for some fishery species. The analysis highlighted many of the challenges confronted in determining habitat-use patterns and emphasized the need for additional systematic sampling to examine geographic variability in habitat use and to examine distribution patterns within habitats. However, in addition to analyses of intrahabitat densities, the identification of EFH requires information on functional relationships between fishery species and habitat characteristics. C1 Natl Marine Fisheries Serv, Galveston SE Fisheries Sci Ctr Lab, Galveston, TX 77551 USA. RP Minello, TJ (reprint author), Natl Marine Fisheries Serv, Galveston SE Fisheries Sci Ctr Lab, 4700 Ave U, Galveston, TX 77551 USA. NR 122 TC 1 Z9 1 U1 1 U2 9 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 USA SN 0892-2284 BN 1-888569-12-3 J9 AM FISH S S PY 1998 VL 22 BP 43 EP 75 PG 33 WC Ecology; Fisheries; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Fisheries; Marine & Freshwater Biology; Oceanography GA BN55F UT WOS:000082192300007 ER PT S AU Packer, DB Hoff, T AF Packer, DB Hoff, T BE Benaka, LR TI Life history, habitat parameters, and essential habitat of mid-Atlantic summer flounder SO FISH HABITAT: ESSENTIAL FISH HABITAT AND REHABILITATION SE AMERICAN FISHERIES SOCIETY SYMPOSIUM LA English DT Proceedings Paper CT Sea Grant Symposium on Fish Habitat - Essential Fish Habitat and Rehabilitation at the 1998 Annual Meeting of the American-Fisheries-Society CY AUG 26-27, 1998 CL HARTFORD, CT SP Amer Fisheries Soc ID LOWER CHESAPEAKE BAY; SOUTHERN NEW-JERSEY; NORTH-CAROLINA ESTUARIES; SHALLOW MARSH HABITATS; CAPE FEAR RIVER; PARALICHTHYS-DENTATUS; LARVAL FISHES; BEAUFORT INLET; GROWTH; PATTERNS AB To satisfy the essential fish habitat (EFH) mandate of the reauthorized Magnuson-Stevens Fishery Conservation and Management Act, the Mid-Atlantic Fishery Management Council (MAFMC) and the National Marine Fisheries Service (NMFS) are developing objective, generic criteria to describe and identify the essential habitats for their managed species. Summer flounder or fluke Paralichthys dentatus is an important commercial and recreational species that occurs from shallow estuaries to the outer continental shelf from Nova Scotia to Florida. It is most abundant within the Middle Atlantic Eight from New England to Cape Hatteras, and this region is the focus of this paper. Summer flounder make seasonal inshore-offshore migrations; adults and juveniles normally inhabit shallow coastal and estuarine waters during the warmer months of the year and mostly move offshore with declining water temperature and day length during autumn. Adults spawn during the fall and winter migrations. The best habitat information available on summer flounder is for the estuarine-dependent transforming larvae and juveniles. They use several different estuarine habitats as nursery areas, including salt-marsh creeks, sea grass beds, mudflats, and open bay areas. In these habitats, water temperature affects the seasonal occurrence of summer flounder, drives the inshore-offshore migration, and, particularly during winter and spring, affects first-year growth and survival and thus subsequent year-class strength. The distribution of transforming larvae and juveniles within the estuaries is significantly influenced by salinity gradients and substrate. Transforming larvae and juveniles show a preference for sandy substrates in the laboratory but also have been captured on mud or mixed substrates. Juveniles are attracted to eelgrass and macroalgae habitats because of the presence of prey but remain in nearby sand to avoid predators as well as conceal themselves from the prey. The MAFMC used the life history and habitat parameter information developed by the NMFS Northeast Fisheries Science Center (NEFSC) to precisely describe the EFH of summer flounder by life stage. Because summer flounder are overexploited, the MAFMC wanted to be conservative in its EFH identification. Therefore, 90% of the areas where each life history stage has been collected from offshore surveys were identified as EFH. The MAFMC proposed that 100% of the estuaries where larvae and juveniles were identified as being present be identified as EFH because these life stages are estuarine dependent. Nursery habitats within the estuaries are essential because they provide the best conditions for growth and survival of the transforming larvae and juveniles. Submerged aquatic vegetation beds are especially vulnerable and were identified as habitat areas of particular concern. As more habitat-related density data become available from various local, state, and federal fishery-independent surveys, updated maps of distribution and abundance will be produced. C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. RP Packer, DB (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. NR 93 TC 0 Z9 0 U1 1 U2 5 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 USA SN 0892-2284 BN 1-888569-12-3 J9 AM FISH S S PY 1998 VL 22 BP 76 EP 92 PG 17 WC Ecology; Fisheries; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Fisheries; Marine & Freshwater Biology; Oceanography GA BN55F UT WOS:000082192300008 ER PT B AU Heifetz, J Quinn, TJ AF Heifetz, J Quinn, TJ BE Funk, F Quinn, TJ Heifetz, J Ianelli, JN Powers, JE Schweigert, JF Sullivan, PJ Zhang, CI TI Dynamics of a migratory fish population with applications to the management of sablefish SO FISHERY STOCK ASSESSMENT MODELS SE LOWELL WAKEFIELD FISHERIES SYMPOSIA SERIES LA English DT Proceedings Paper CT International Symposium on Fishery Stock Assessment Models for the 21st-Century CY OCT 08-11, 1997 CL ANCHORAGE, AK ID CATCH-AGE ANALYSIS; PACIFIC; MODELS; COD AB The reproduction, mortality, and migration of an age-structured fish population can be incorporated into a matrix model. The population projection matrix for such a model describes the dynamics of age classes within regions and the migration among regions. Such a model provides a flexible framework to examine the dynamics of a migratory fish population. The model can be parameterized to include regional specificity in the stock-recruitment relationship as well as larval dispersal that is decoupled from local reproduction. The subject of oriented movement, where young fish tend to migrate in the opposite direction of older fish is examined within the context of the sablefish (Anoplopoma fimbria) fishery in the northeast Pacific Ocean. We show that fishing at a common rate among regions may be appropriate for the pooled population but may be detrimental to the population in a given region. As an alternative, region-specific fishing strategies can be devised to meet fishery management objectives such as maintenance of regional spawning potential. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, NOAA, Juneau, AK 99801 USA. RP Heifetz, J (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, NOAA, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 38 TC 3 Z9 3 U1 0 U2 0 PU ALASKA SEA GRANT COLL PROGRAM PI FAIRBANKS PA UNIV ALASKA FAIRBANKS PO BOX 755040, FAIRBANKS, AK 99775-5040 USA BN 1-56612-057-8 J9 LOW WAKE FI PY 1998 VL 15 BP 219 EP 244 PG 6 WC Computer Science, Interdisciplinary Applications; Fisheries SC Computer Science; Fisheries GA BN15M UT WOS:000080877100012 ER PT B AU Pella, JJ Masuda, MM Chen, DG AF Pella, JJ Masuda, MM Chen, DG BE Funk, F Quinn, TJ Heifetz, J Ianelli, JN Powers, JE Schweigert, JF Sullivan, PJ Zhang, CI TI Forecast methods for inseason management of the Southeast Alaska chinook salmon troll fishery SO FISHERY STOCK ASSESSMENT MODELS SE LOWELL WAKEFIELD FISHERIES SYMPOSIA SERIES LA English DT Proceedings Paper CT International Symposium on Fishery Stock Assessment Models for the 21st-Century CY OCT 08-11, 1997 CL ANCHORAGE, AK AB Under an agreement among U.S, commissioners of the Pacific Salmon Commission (Allen 1996), the allowable catch of chinook salmon in Southeast Alaska for 1997 depended on abundance in the fishery. Historically, abundance has been forecast prior to the summer fishery and evaluated later, from numerous information sources, by the Chinook Technical Committee of the Pacific Salmon Commission. Here, early catch rates during the summer fishery are shown to reflect abundance and are used to update the preseason forecast for use by the commissioners in assessing the allowable catch. The Bayesian calibrative distribution for the updated abundance provides the inseason statistical description of its uncertainty arising from unknown parameter values and random variables of underlying models. Cross validation shows that the mode of the Bayesian calibrative distribution would have produced more accurate forecasts than either the preseason forecast or a maximum likelihood forecast from the early catch rates alone. C1 Natl Marine Fisheries Serv, Auke Bay Lab, NOAA, Juneau, AK 99801 USA. RP Pella, JJ (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, NOAA, 11305 Glacier Highway, Juneau, AK 99801 USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU ALASKA SEA GRANT COLL PROGRAM PI FAIRBANKS PA UNIV ALASKA FAIRBANKS PO BOX 755040, FAIRBANKS, AK 99775-5040 USA BN 1-56612-057-8 J9 LOW WAKE FI PY 1998 VL 15 BP 287 EP 314 PG 6 WC Computer Science, Interdisciplinary Applications; Fisheries SC Computer Science; Fisheries GA BN15M UT WOS:000080877100014 ER PT B AU Crone, PR Sampson, DB AF Crone, PR Sampson, DB BE Funk, F Quinn, TJ Heifetz, J Ianelli, JN Powers, JE Schweigert, JF Sullivan, PJ Zhang, CI TI Evaluation of assumed error structure in stock assessment models that use sample estimates of age composition SO FISHERY STOCK ASSESSMENT MODELS SE LOWELL WAKEFIELD FISHERIES SYMPOSIA SERIES LA English DT Proceedings Paper CT International Symposium on Fishery Stock Assessment Models for the 21st-Century CY OCT 08-11, 1997 CL ANCHORAGE, AK ID STATISTICAL CONSIDERATIONS; CATCH; ROCKFISH AB The sampling error associated with estimates of age composition for five groundfish species commercially landed at Oregon ports is used to examine the ability of age-structured stock assessment models to adequately describe the stochastic properties of actual catch-at-age data. Specifically, estimated coefficients of variation associated with samples of catch-at-age are presented graphically to evaluate a theoretical consideration involved in stock assessment models widely used in marine fishery management. Results presented here indicate that a multinomial probability error structure, included in models that are based on maximum likelihood estimation, more closely follows the variability associated with the sampled landing data than does a lognormal error structure used in models based on least squares estimation. Weighted nonlinear regression analysis is used to determine the specific multinomial distribution (sample size n) that provides the most accurate description of the actual variability associated with the sample estimates of age composition. Implications for stock assessment modeling are discussed. Finally, a linear regression model is derived that describes the relationship between multinomial sample size and the number of boat trips sampled, in efforts to provide an adequate error structure for the models without having to rely on the relatively complex and tedious sampling estimators and subsequent analytical techniques. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Hatfield Marine Sci Ctr, NOAA, Newport, OR 97365 USA. RP Crone, PR (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Hatfield Marine Sci Ctr, NOAA, 2030 SE Marine Sci Dr, Newport, OR 97365 USA. NR 35 TC 16 Z9 16 U1 0 U2 2 PU ALASKA SEA GRANT COLL PROGRAM PI FAIRBANKS PA UNIV ALASKA FAIRBANKS PO BOX 755040, FAIRBANKS, AK 99775-5040 USA BN 1-56612-057-8 J9 LOW WAKE FI PY 1998 VL 15 BP 355 EP 370 PG 4 WC Computer Science, Interdisciplinary Applications; Fisheries SC Computer Science; Fisheries GA BN15M UT WOS:000080877100017 ER PT B AU Brodziak, J Rago, P Conser, R AF Brodziak, J Rago, P Conser, R BE Funk, F Quinn, TJ Heifetz, J Ianelli, JN Powers, JE Schweigert, JF Sullivan, PJ Zhang, CI TI A general approach for making short-term stochastic projections from an age-structured fisheries assessment model SO FISHERY STOCK ASSESSMENT MODELS SE LOWELL WAKEFIELD FISHERIES SYMPOSIA SERIES LA English DT Proceedings Paper CT International Symposium on Fishery Stock Assessment Models for the 21st-Century CY OCT 08-11, 1997 CL ANCHORAGE, AK ID ASSESSMENT ADVICE; CATCH; STOCK; UNCERTAINTY AB Catch-age analysis is a powerful tool for assessing the status of fisheries resources and catch-age analyses are routinely conducted for many commercially exploited fish stocks around the world. In this paper, we illustrate a general approach for making short-term stochastic projections from the ADAPT age-structured assessment model. Our approach uses the standard statistical. techniques of bootstrapping and Monte Carlo simulation to project performance measures such as landings, discards, spawning biomass, and recruitment under alternative management policies. The key idea is to propagate variability in estimates of initial stock size forward in stochastic projections of future possibilities. We use bootstrap replicates of current population size from an age-structured ADAPT model combined with a stochastic stock-recruitment relationship to simulate population trajectories through the projection horizon. The approach is illustrated for a commercially important New England groundfish, Georges Bank yellowtail flounder, Pleuronectes ferrugineus. Although hypothetical, this illustration provides some general insight for the rebuilding of the Georges Bank yellowtail flounder stock. C1 NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA. RP Brodziak, J (reprint author), NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA. NR 41 TC 3 Z9 3 U1 0 U2 0 PU ALASKA SEA GRANT COLL PROGRAM PI FAIRBANKS PA UNIV ALASKA FAIRBANKS PO BOX 755040, FAIRBANKS, AK 99775-5040 USA BN 1-56612-057-8 J9 LOW WAKE FI PY 1998 VL 15 BP 933 EP 954 PG 6 WC Computer Science, Interdisciplinary Applications; Fisheries SC Computer Science; Fisheries GA BN15M UT WOS:000080877100052 ER PT J AU Jongen, T Machiels, L Gatski, TB AF Jongen, T Machiels, L Gatski, TB TI Predicting noninertial effects with linear and nonlinear eddy-viscosity, and algebraic stress models SO FLOW TURBULENCE AND COMBUSTION LA English DT Article; Proceedings Paper CT 11th Symposium on Turbulent Shear Flows CY SEP 08-10, 1997 CL GRENOBLE, FRANCE DE nonlinear eddy-viscosity model; algebraic stress model; noninertial effects ID TURBULENT CHANNEL FLOW; SPANWISE ROTATION; DISSIPATION AB Three types of turbulence models which account for rotational effects in noninertial frames of reference are evaluated for the case of incompressible, fully developed rotating turbulent channel how The different types of models are a Coroiolis-modified eddy-viscosity model, a realizable nonlinear eddy-viscosity model, and an algebraic stress model which accounts for dissipation rate anisotropies. A direct numerical simulation of a rotating channel Bow is used for the validation of the turbulence models. This simulation differs from previous studies in that significantly higher rotation numbers are investigated. Flows at these higher rotation numbers are characterized by a relaminarization on the cyclonic or suction side of the channel, and a linear velocity profile on the anticyclonic or pressure side of the channel. The predictive performance of the three types of models are examined in detail, and formulation deficiencies are identified which cause poor predictive performance for some of the models. Criteria are identified which allow for accurate prediction of such Bows by algebraic stress models and their corresponding Reynolds stress formulations. C1 Swiss Fed Inst Technol, Fluid Mech Lab, CH-1015 Lausanne, Switzerland. NASA, Langley Res Ctr, Aerodynam & Acoust Methods Branch, Hampton, VA 23681 USA. RP Swiss Fed Inst Technol, Fluid Mech Lab, CH-1015 Lausanne, Switzerland. NR 14 TC 11 Z9 11 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1386-6184 EI 1573-1987 J9 FLOW TURBUL COMBUST JI Flow Turbul. Combust. PY 1998 VL 60 IS 2 BP 215 EP 234 DI 10.1023/A:1009947620019 PG 20 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA 181BR UT WOS:000079421200005 ER PT B AU Trujillo, AC AF Trujillo, AC GP IEEE COMP SOC TI Pilot mental workload with predictive system status information SO FOURTH ANNUAL SYMPOSIUM ON HUMAN INTERACTION WITH COMPLEX SYSTEMS, PROCEEDINGS LA English DT Proceedings Paper CT 4th Annual Symposium on Human Interaction with Complex Systems (HICS 98) CY MAR 22-25, 1998 CL DAYTON, OH SP IEEE, Comp Soc, IEEE, Comp Soc Tech Comm Multimedia Comp, Lexis Nexis, USAF, Armstrong Lab, Wright State Univ, N Carolina A&T State Univ AB Research has shown a strong pilot preference for predictive information of aircraft system status in the flight deck. However, the mental workload associated with using this predictive information has not been ascertained. The study described here attempted to measure mental workload. In this simulator experiment, three types of predictive information (none, whether a parameter was changing abnormally, and the time for a parameter to reach an alert range) and four initial times to a parameter alert range (I minute, 5 minutes, 15 minutes, and ETA+45 minutes) were tested to determine their effects on subjects' mental workload Subjective workload ratings increased with increasing predictive information (whether a parameter was changing abnormally or the time for a parameter to reach an alert range). Subjective situation awareness decreased with more predictive information but it became greater with increasing initial times to a parameter alert range. Also, subjective focus changed depending on the type of predictive information. Lastly, skin temperature fluctuated less as the initial time to a parameter alert range increased. C1 NASA, Langley Res Ctr, Crew Vehicle Integrat Branch, Hampton, VA 23665 USA. RP Trujillo, AC (reprint author), NASA, Langley Res Ctr, Crew Vehicle Integrat Branch, Hampton, VA 23665 USA. NR 0 TC 8 Z9 8 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8341-4 PY 1998 BP 73 EP 80 DI 10.1109/HUICS.1998.659958 PG 8 WC Computer Science, Cybernetics; Computer Science, Information Systems SC Computer Science GA BK78U UT WOS:000073380600007 ER PT B AU Degani, A Kirlik, A AF Degani, A Kirlik, A GP IEEE COMP SOC TI Describing the design contributors to mode error SO FOURTH ANNUAL SYMPOSIUM ON HUMAN INTERACTION WITH COMPLEX SYSTEMS, PROCEEDINGS LA English DT Proceedings Paper CT 4th Annual Symposium on Human Interaction with Complex Systems (HICS 98) CY MAR 22-25, 1998 CL DAYTON, OH SP IEEE, Comp Soc, IEEE, Comp Soc Tech Comm Multimedia Comp, Lexis Nexis, USAF, Armstrong Lab, Wright State Univ, N Carolina A&T State Univ AB Although mode error has attracted a great deal of recent interest from those involved with complex systems, the design factors that contribute to this problems are not well understood. In this paper we provide an introduction to a modeling framework we use to describe complex, multi-modal human-machine systems. The modeling approach is based on the statechart formalism, which is an extension of the finite state machine formalism to allow representation of concurrency: hierarchy, default transitions, and broadcast of parameter information. After having used this approach to model a number of human-machine systems known to create made central problems for the operator, we have identified a number of system design features that contribute to mode error. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Degani, A (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8341-4 PY 1998 BP 112 EP 115 DI 10.1109/HUICS.1998.659964 PG 4 WC Computer Science, Cybernetics; Computer Science, Information Systems SC Computer Science GA BK78U UT WOS:000073380600011 ER PT B AU Xiong, YL Turkowski, K AF Xiong, YL Turkowski, K GP IEEE COMP SOC IEEE COMP SOC TI Registration, calibration and blending in creating high quality panoramas SO FOURTH IEEE WORKSHOP ON APPLICATIONS OF COMPUTER VISION - WACV'98, PROCEEDINGS LA English DT Proceedings Paper CT 4th IEEE Workshop on Applications of Computer Vision (WACV 98) CY OCT 19-21, 1998 CL PRINCETON, NJ SP IEEE Comp Soc, Tech Comm Pattern Anal & Machine Intelligence AB This paper presents a system for creating a full 360-degree panorama from rectilinear images captured from a single nodal position. The solution to the problem is divided into three steps. The first step registers all overlapping images projectively. A combination of a gradient-based optimization method and a correlation-based linear search is found to be robust even in cases of drastic exposure differences and small amount of parallax. The second step takes the projective matrices and their associated hessian matrices us inputs, and calibrates the internal and external parameters of every images through a global optimization. The objective is to minimize the overall image discrepancies in all overlap regions while converting projective matrices into camera parameters such as focal length, aspect ratio, image center, 3D orientation, etc. The third step re-projects all images onto a panorama by a Laplacian-pyramid-based blending. The purpose of blending is to provide a smooth transition between images and eliminate smell residues of misalignments resulting from parallax or imperfect pairwise registrations. The blending masks are generated automatically through the grassfire transform. At the end, we briefly explain the necessary human interface for initialization, feedback and manual options. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Xiong, YL (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 IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8606-5 PY 1998 BP 69 EP 74 DI 10.1109/ACV.1998.732860 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BM17J UT WOS:000077905500011 ER PT S AU Tin, P Mann, JA Meyer, WV AF Tin, P Mann, JA Meyer, WV BE Jung, CC Udd, E TI Non-invasive measurement of surface tension and viscosity with fiber optics light scattering spectrometer SO FOURTH PACIFIC NORTHWEST FIBER OPTIC SENSOR WORKSHOP SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 4th Pacific Northwest Fiber Optic Sensor Workshop CY MAY 06-07, 1998 CL TROUTDALE, OR SP Blue Road Res, SPIE DE surface light scattering; surface tension; viscosity; fiber optics heterodyning AB Traditional methods of measuring surface tension and viscosity of liquid/vapor interfaces are invasive systems making unavoidable mechanical contact with the interface that is under investigation. We have demonstrated a complete fiber optics based heterodyne sensor system that non-invasively measures the interfacial surface tension and viscosity. Measured values from this complete fiber optics system for some simple liquid vapor interfaces give consistent values with established values obtained by other invasive methods. RP Tin, P (reprint author), NASA, Lewis Res Ctr, OAI, MS 105-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 2 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2948-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3489 BP 110 EP 121 DI 10.1117/12.323423 PG 12 WC Optics SC Optics GA BL85X UT WOS:000076962400016 ER PT S AU Biswas, A Williams, G Wilson, KE Hakakha, H Steiger, R Korevaar, E AF Biswas, A Williams, G Wilson, KE Hakakha, H Steiger, R Korevaar, E BE Mecherle, GS TI Results of the STRV-2 lasercom terminal evaluation tests SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies X CY JAN 27-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE STRV-2; free space optical communications; lasercom testing and evaluation AB The STRV-2 lasercom terminal (LCT) was designed and developed by AstroTerra Corporation of San Diego, California, under funding from the Ballistic Missile Defense Organization (BMDO). Scheduled for launch in late 1998 it will be used to demonstrate, for the first time, high data rate bi-directional satellite-to-ground optical communications. Concurrently with the development of the STRV-2 lasercom NASA/JPL was assembling the lasercom test and evaluation station (LTES), a high quality test platform for pre-flight characterization of optical communications terminals. The respective development schedules allowed evaluation of the STRV-2 LCT using LTES, for a month, prior to integration of the LCT with the spacecraft palette. Final co-alignment of the transmitter lasers to within +/-20 mu rads with respect to the receive axis was achieved. This in turn allowed the specified 76 mu rad transmit beam divergence to be realized. However, subjecting the LCT to expected on-orbit temperatures revealed that the co-alignment deteriorated causing beam spreading, a finding which prompted the recommendation to operate the lasers warmed up during ground encounters. The "bent-pipe" operation bit-error rates (BER) at 155, 194 and 325 Mbps were less than or equal to 1E-10 over a similar to 20 dB range of irradiance measured at the receive telescope aperture. At 500 Mbps BER's of 1E-6 were achieved over a similar to 6 dB irradiance range, suggesting greater vulnerability to atmosphere induced fades. A pointing offset between the acquisition receivers and transmitter lasers of 1 mrad was measured. The impact of this offset will be to limit acquisition camera framing rates to 87 and 251 Hz, thus limiting the tracking loop bandwidth. Tracking performance tests of the lasercom terminal, though planned, could not be carried out because the software was not ready at the time of testing with LTES. The test results obtained for STRV-2 lasercom terminal will be used for designing the ground receiver. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Biswas, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 0 TC 3 Z9 4 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2705-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3266 BP 2 EP 13 DI 10.1117/12.308694 PG 12 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BL19T UT WOS:000074658900001 ER PT S AU Biswas, A Wilson, KE Page, NA AF Biswas, A Wilson, KE Page, NA BE Mecherle, GS TI Lasercom Test and Evaluation Station (LTES) development: an update SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies X CY JAN 27-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE lasercom terminal; free space optical communications; testbed; test and evaluation AB Pre-launch integrated system characterization of a lasercom terminal's (LCT's) communications and acquisition/tracking subsystems can provide a quantitative evaluation of the terminal and afford a better rigorous assessment of the benefits of any demonstration. The lasercom test and evaluation station developed at NASA/JPL is a high quality optical system that possesses the unique capabilities required to provide laboratory measurements of the key characteristics of lasercom terminals operating over the visible and near-infrared spectral region. Over the past year LTES has been used to provide pre-flight testing of the STRV-2 lasercom terminal developed by AstroTerra Corporation of San Diego, CA, and is currently being used for testing of the Optical Communication Demonstrator (OCD) developed by NASA/JPL. Discussions of performance validation tests carried out on LTES and its diverse capabilities are reported in this paper. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Biswas, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 3 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2705-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3266 BP 22 EP 32 DI 10.1117/12.308712 PG 11 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BL19T UT WOS:000074658900003 ER PT S AU Jeganathan, M Monacos, S AF Jeganathan, M Monacos, S BE Mecherle, GS TI Performance analysis and electronics packaging of the optical communications demonstrator SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies X CY JAN 27-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE optical communications; laser communications; beacon acquisition; tracking; free-space; LEO; GEO; OCD AB The Optical Communications Demonstrator (OCD), under development at the Jet Propulsion Laboratory (JPL), is a laboratory-based lasercomm terminal designed to validate several key technologies, primarily precision beam pointing, high bandwidth tracking, and beacon acquisition. The novelty of the instrument is that it uses a single CCD array detector for both beacon acquisition and tracking, and a fiber-coupled laser transmitter. The resulting reduction in design complexity can lead to a reduced system cost and an improved system reliability. In this paper, we describe recent progress on the development of the OCD terminal, particularly the electronics packaging and optical characterization with the Lasercom Test and Evaluation Station (LTES). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jeganathan, M (reprint author), CALTECH, Jet Prop Lab, MS 161-135,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 7 Z9 7 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2705-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3266 BP 33 EP 41 DI 10.1117/12.308715 PG 9 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BL19T UT WOS:000074658900004 ER PT S AU Jeganathan, M Mecherle, GS Lesh, JR AF Jeganathan, M Mecherle, GS Lesh, JR BE Mecherle, GS TI Development of the free-space optical communications analysis software SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies X CY JAN 27-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE optical communications; laser communications; free-space; link budget; link table; link analysis AB The Free-space Optical Communication Analysis Software (FOCAS) was developed at the Jet Propulsion Laboratory (JPL) to provide mission planners, systems engineers and communications engineers with an easy to use tool to analyze direct-detection optical communication links. The FOCAS program, implemented in Microsoft Excel, gives it all the power and flexibility built into the spreadsheet. An easy-to-use interface, developed using Visual Basic for Applications (VBA), to the spreadsheet allows easy input of data and parameters. A host of pre-defined components allow an analyst to configure a link without having to know the details of the components. FOCAS replaces the over-a-decade-old FORTRAN program called OPTI widely used previously at JPL. This paper describes the features and capabilities of the Excel-spreadsheet-based FOCAS program. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jeganathan, M (reprint author), CALTECH, Jet Prop Lab, MS 161-135,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 3 Z9 3 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2705-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3266 BP 90 EP 98 DI 10.1117/12.308697 PG 9 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BL19T UT WOS:000074658900010 ER PT S AU Sandusky, JV Lesh, JR AF Sandusky, JV Lesh, JR BE Mecherle, GS TI Planning for a long-term optical demonstration from the international space station SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies X CY JAN 27-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE optical communication; International Space Station; lasercom AB The Optical Communications Group at the Jet Propulsion Laboratory will deploy an optical communications transmitter demonstration and facility to the International Space Station in January 2002. The purpose of the demonstration is to establish a Gbps-class downlink from the International Space Station to ground and measure the flight terminal's performance. A large number of downlink passes are required to accurately measure the flight terminal's performance and the International Space Station provides such a long-term demonstration opportunity. The International Space Station simultaneously provides a payload-friendly environment. In this paper we discuss the objectives of the optical communications demonstration as well as the schedule for and issues related to the design, construction, and deployment of the flight terminal. C1 CALTECH, Jet Prop Lab, Opt Commun Grp, Pasadena, CA 91109 USA. RP Sandusky, JV (reprint author), CALTECH, Jet Prop Lab, Opt Commun Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2705-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3266 BP 128 EP 134 DI 10.1117/12.308701 PG 7 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BL19T UT WOS:000074658900014 ER PT S AU Wilson, KE Sandusky, J AF Wilson, KE Sandusky, J BE Mecherle, GS TI Development of a 1-m class telescope at TMF to support optical communications demonstrations SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies X CY JAN 27-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE optical communications; telescopes; adaptive optics; astrometry; Table Mountain Facility AB With the impetus towards high data rate communications in inter-satellite and space-to-ground links, the small size, low-mass, and low-power consumption of optical communications is seen as a viable alternative to radio frequency links. Recent NASA/JPL optical communications field demonstrations have shown some of the operational strategies needed for space-to-ground optical links. In preparation for the optical communications demonstrations planned for the tum of the century, NASA/JPL is building an Optical Communications Telescope Laboratory (OCTL) with a 1-m class telescope. The OCTL will be located at JPL's Table Mountain Facility complex in the San Bernadino mountains of Southern California and will be capable of supporting demonstrations with satellites from LEO to deep space ranges. In addition, it will support advanced optical communications research, astrometry and astronomy research. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wilson, KE (reprint author), CALTECH, Jet Prop Lab, MS 161-135,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2705-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3266 BP 146 EP 152 DI 10.1117/12.308703 PG 7 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BL19T UT WOS:000074658900016 ER PT S AU Hemmati, H Lesh, JR AF Hemmati, H Lesh, JR BE Mecherle, GS TI A combined laser-communication and imager for microspacecraft (ACLAIM) SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies X CY JAN 27-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE laser communication; optical communication; science imaging; micro-spacecraft AB ACLAIM is a multi-function instrument consisting of a laser communication terminal and an imaging camera that share a common telescope. A single APS- (Active Pixel Sensor) based focal-plane-array is used to perform both the acquisition and tracking (for laser communication) and science imaging functions. ACLAIM was designed based on all commercially available catalog items. The instrument opto-mechanical design and performance is described here. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hemmati, H (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 SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2705-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3266 BP 165 EP 170 DI 10.1117/12.308706 PG 6 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BL19T UT WOS:000074658900018 ER PT S AU Hemmati, H Lesh, JR AF Hemmati, H Lesh, JR BE Mecherle, GS TI Laser communications terminal for the X2000 series of planetary missions SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies X CY JAN 27-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE laser communications; optical communications; telescopes; science imaging; laser altimeter reception; space missions; detector arrays; APS detectors AB A new program called the Advanced Deep-Space Systems Development Program (a.k.a. X2000 Program) has been initiated to develop new cutting-edge technologies for NASA's deep-space missions in an overall flight project environment. Several technologies have been selected for development under the first delivery of the X2000 Program. Optical communications is one of those technologies. This paper provides an overview of the X2000 Program and describes the optical communications terminal that will be developed therein. The spacecraft terminal will be a multi-function instrument, capable of not only two-way communications from distances out to Europa (Jupiter), but two-way ranging, science imaging and laser altimeter reception as well. The plan for the development of the terminal is also described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hemmati, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2705-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3266 BP 171 EP 177 DI 10.1117/12.308707 PG 7 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BL19T UT WOS:000074658900019 ER PT S AU Jeganathan, M Jalali, N AF Jeganathan, M Jalali, N BE Mecherle, GS TI Analysis of data from the Atmospheric Visibility Monitoring (AVM) program SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies X CY JAN 27-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE atmospheric visibility; atmospheric transmission; atmospheric attenuation; cloud-cover statistics; freespace optical communication; laser communication; link Budget; AVM; CDF; PDF AB The Atmospheric Visibility Monitoring (AVM) program at the Jet Propulsion Laboratory has been in place for the last few years to obtain atmospheric transmission statistics data to support free-space optical communications experiments and missions. Atmospheric transmission data is collected through a set of three autonomous systems, all located in the south-western U.S., that observe selected stars throughout the year. Data from these three sites are collected and processed on a regular basis to obtain cumulative distribution functions of atmospheric attenuation for different spectral windows of interest. In this paper, we describe recent work on creation of a database using Microsoft access to analyze atmospheric transmission data collected by the AVM project. The database, which replaces time-consuming Matlab programs, offers a rapid and extremely easy way to extract and analyze AVM data. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jeganathan, M (reprint author), CALTECH, Jet Prop Lab, MS 161-135,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2705-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3266 BP 200 EP 208 DI 10.1117/12.308708 PG 9 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BL19T UT WOS:000074658900021 ER PT B AU Grillmair, CJ AF Grillmair, CJ BE Zaritsky, D TI Probing the Galactic halo with globular cluster tidal tails SO GALACTIC HALOS: A UC SANTA CRUZ WORKSHOP SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Galactic Halos - a UC Santa Cruz Workshop CY AUG 11-15, 1997 CL UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA SP Lick Observ, Natl Sci F, Astron Soc Pacific HO UNIV CALIF SANTA CRUZ AB We discuss recent observational and numerical work on tidal tails in globular clusters. Evidence of tidal tails has now been found in 16 Galactic globulars and 4 globulars in M31. Simulations indicate that mapping of these tidal tails over most of a typical cluster's orbit may be quite feasible. A relatively modest effort in this regard would yield reliable space velocities for those clusters whose tidal tails could be traced to angular separations of a few degrees or more. Mining of forthcoming databases should allow us to trace the individual orbital paths of globular clusters over large portions of the sky. This would enable us to better constrain models of the collapse of the Galaxy and to build up an accurate picture of the distribution of matter in the Galactic halo. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Grillmair, CJ (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-900,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 12 Z9 12 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-56-2 J9 ASTR SOC P PY 1998 VL 136 BP 45 EP 52 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL74E UT WOS:000076528200009 ER PT B AU Snowden, SL AF Snowden, SL BE Zaritsky, D TI X-ray halos of the Milky Way and Magellanic Clouds SO GALACTIC HALOS: A UC SANTA CRUZ WORKSHOP SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Galactic Halos - a UC Santa Cruz Workshop CY AUG 11-15, 1997 CL UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA SP Lick Observ, Natl Sci F, Astron Soc Pacific HO UNIV CALIF SANTA CRUZ AB Recent results from the analysis of ROSATPSPC data demonstrate the existence of extensive diffuse X-ray emission above the disk of the Milky Way. This includes an X-ray bulge at the center of the Galaxy with an exponential scale height of similar to 2 kpc and temperature of similar to 10(6.6) K, and emission above the disk at least near the solar location at similar to 10(6.0) K. However, the story for the Magellanic Clouds is different. While the Large Magellanic Cloud shows bright diffuse emission it is unclear how much, if any, can be considered as originating from a halo. The Small Magellanic Cloud shows much less diffuse emission and no support for any in a halo. The 1/4 keV results for the Magellanic Clouds are tempered by the fact that emission at similar to 10(6.0) K from the LMC is heavily absorbed by the foreground Galactic column density of H I while any emission from the SMC is confused by Galactic emission as well as absorption. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Snowden, SL (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. RI Snowden, Steven/D-5292-2012 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 USA BN 1-886733-56-2 J9 ASTR SOC P PY 1998 VL 136 BP 127 EP 134 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL74E UT WOS:000076528200025 ER PT B AU Loewenstein, M White, RE AF Loewenstein, M White, RE BE Zaritsky, D TI Do elliptical galaxies have dark matter? SO GALACTIC HALOS: A UC SANTA CRUZ WORKSHOP SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Galactic Halos - a UC Santa Cruz Workshop CY AUG 11-15, 1997 CL UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA SP Lick Observ, Natl Sci F, Astron Soc Pacific HO UNIV CALIF SANTA CRUZ AB We present constraints on the properties of dark matter halos in elliptical galaxies from the relationship between X-ray temperature and velocity dispersion observed in an optically complete sample. We demonstrate the ubiquity of dark matter in L > L* galaxies, present limits on the dark matter structural parameters, and discuss the scaling of dark matter with optical luminosity. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Loewenstein, M (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. 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 USA BN 1-886733-56-2 J9 ASTR SOC P PY 1998 VL 136 BP 306 EP 308 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL74E UT WOS:000076528200057 ER PT S AU Meegan, CA Paciesas, WS Pendleton, GN Briggs, MS Kouveliotou, C Koshut, TM Lestrade, JP McCollough, ML Brainerd, JJ Hakkila, J Henze, W Preece, RD Connaughton, V Kippen, RM Mallozzi, RS Fishman, GJ AF Meegan, CA Paciesas, WS Pendleton, GN Briggs, MS Kouveliotou, C Koshut, TM Lestrade, JP McCollough, ML Brainerd, JJ Hakkila, J Henze, W Preece, RD Connaughton, V Kippen, RM Mallozzi, RS Fishman, GJ BE Meegan, CA Preece, RD Koshut, TM TI The 4B BATSE gamma-ray burst catalog SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB The 4B catalog of gamma-ray bursts includes all BATSE triggered bursts from launch until 29 August 1996. The total number of bursts is 1637, including 515 bursts since the end oi the 3B catalog. The post-3B time interval includes periods when the trigger criteria were not at the nominal energy interval or intensity. Therefore, care must be exercised in deriving global properties from this catalog. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Meegan, CA (reprint author), NASA, George C Marshall Space Flight Ctr, ES84, Huntsville, AL 35812 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 3 EP 9 PG 7 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200001 ER PT S AU Barthelmy, SD Butterworth, P Cline, TL Gehrels, N Marshall, F Takeshima, T Connaughton, V Kippen, RM Kouveliotou, C Robinson, CR AF Barthelmy, SD Butterworth, P Cline, TL Gehrels, N Marshall, F Takeshima, T Connaughton, V Kippen, RM Kouveliotou, C Robinson, CR BE Meegan, CA Preece, RD Koshut, TM TI The GRB Coordinates Network (GCN): A status report SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB A review of the GRB Coordinates Network (GCN) will be given. The GCN has recently replaced the BATSE Coordinates Distribution Network (BACODINE), maintaining all of BACODINE's original capabilities and services, but also providing new sources of GRB location information. These are: (1) source locations using the MSFC LOCBURST algorithm, (2) the Rossi-XTE detections (PCA and ASM), (3) the Interplanetary Network (IPN) locations, and (4) CGRO-COMPTEL locations. These new sources of locations are available for distribution in the minutes-to-hours-to-days time delay ranges, and they also have increasingly and significantly reduced error boxes, thus providing a broad range of time delays and error box sizes to fit within the observing capabilities of a broad range of follow-up instruments in the radio, optical, and TeV gamma-ray bands. Extreme-UV transients from ALEXIS are also now distributed. For all sources of location information, all the distribution methods are available (Internet Socket, E-mail, Alpha-numeric and Numeric Pagers, and Phone/modem) and several filters. Sites can choose which sources to receive and what filters to be applied. The GCN web site has been expanded to include a globally inclusive table of locations, light-curves, and fluence information which is automatically updated in real-time. C1 NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RP Barthelmy, SD (reprint author), NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RI Barthelmy, Scott/D-2943-2012 NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 99 EP 103 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200020 ER PT S AU Barthelmy, SD AF Barthelmy, SD BE Meegan, CA Preece, RD Koshut, TM TI Observing strategies using GCN SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB Given the broad range of error box sizes available from the GRB Coordinates Network (GCN) and the range of time delays involved, there is now the opportunity for many more instruments, than could use the old BACODINE: system, to make follow-up observations to detect the GRB counterpart. We present a set of scenarios (some taken from existing GCN site operations and some from anticipated operations) to guide the potential new observer in matching his/her instrument's capabilities with the GCN burst location information and in setting up :he follow-up observing procedures. C1 NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RP Barthelmy, SD (reprint author), NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RI Barthelmy, Scott/D-2943-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 129 EP 133 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200026 ER PT S AU Barthelmy, SD Butterworth, P AF Barthelmy, SD Butterworth, P BE Meegan, CA Preece, RD Koshut, TM TI The GCN web page for real-time GRB information: Locations, intensities, fluences and light curves SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB One of the enhancements of the newly created GRB Coordinates Network (CCN) is a web page that contains ail the RA: Dec, Date. Time, and Intensity information distributed hy the GCN, plus some additional information not amenable to the other GCN distribution methods. The web page is a table with a.ll the BATSE-Original, -Final, -MAXBC, anti -LOCBURST, RXTE-PCA, RXTE-ASM, COMPTEL and IPN information, plus light-curves. The page is automatically updated by the GCN programs in real-time (within a minute after the information is distributed by GCN). This table provides the follow-up observer with a central location where he/she call see the pertinent information summarized so that he/she can make optimal decisions on whether to observe a given GRB, and, if so, then determine the details of the observation. The web page Format and contents are described and suggested uses are given. C1 NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RP Barthelmy, SD (reprint author), NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RI Barthelmy, Scott/D-2943-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 134 EP 138 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200027 ER PT S AU Barthelmy, SD Butterworth, P Cline, TL Gehrels, N AF Barthelmy, SD Butterworth, P Cline, TL Gehrels, N BE Meegan, CA Preece, RD Koshut, TM TI A summary of observations made by the GRB Coordinates Network (GCN) sites SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB We present a status report on the broad range of follow-up observations made by the various GRB Coordinates Network (GCN) operations. Because of the wide variety and complexity of the observations, only summaries for each site and each waveband will be reported: numbers of observations and range for the time delays to be on-target, error box coverage percentages, and flux measurements or upper limits. Emphasis will be given to follow-up observations within the last year. A few of the more significant sites and observations will be high-lighted and a Ij.sting of the new instruments soon to come on-line will be given. C1 NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RP Barthelmy, SD (reprint author), NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012; Barthelmy, Scott/D-2943-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 139 EP 143 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200028 ER PT S AU McCollough, ML Meegan, CA Pendleton, GN AF McCollough, ML Meegan, CA Pendleton, GN BE Meegan, CA Preece, RD Koshut, TM TI Geocenter angle distribution of the 4B catalog SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB We examine the geocenter angle distribution of the 1637 bursts contained within the 4B catalog. The distribution is modelled using an isotropic distribution of gamma-ray bursts and a sharp cutoff due to the presence of the earth. A comparison between the observed distribution and the model is made, which provides an independent assessment of the BATSE location errors. Examination of the error distribution near the earth cutoff is presented. C1 NASA, George C Marshall Space Flight Ctr, USRA, Huntsville, AL 35812 USA. RP McCollough, ML (reprint author), NASA, George C Marshall Space Flight Ctr, USRA, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 154 EP 158 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200031 ER PT S AU Norris, JP Scargle, JD Bonnell, JT Nemiroff, RJ AF Norris, JP Scargle, JD Bonnell, JT Nemiroff, RJ BE Meegan, CA Preece, RD Koshut, TM TI Is time dilation extrinsic or intrinsic? SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB Recent detections of gamma-ray burst (GRB) counterparts confirm their great distances and consequent potential use as cosmic probes. However, GRB diversity may thwart this idea. The scatter of intrinsic GRB properties could easily mask the extrinsic effect of cosmological time dilation. Current investigations examine the question of temporal self-similarity: Extrinsic time dilation must be manifest with the same factor on all GRB timescales as a function of distance. Here we show that time-reversal-independent analysis of GRB time profiles using a peak alignment methodology reveals average profiles with approximately equal rise and decay timescales, per peak-flux group, except for the dimmest group, This departure from self-similarity is consistent with a selection effect: At sufficiently low peak fluxes, the BATSE causal trigger misses dim, slowly rising bursts. Interestingly, for GRB970508, the redshift-corrected time-dilation factor inferred for its peak flux is consistent with the measured redshift, z = 0.835, if bright bursts lie at redshifts of a few tenths. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Norris, JP (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 171 EP 175 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200034 ER PT S AU Scargle, JD Norris, J Bonnell, J AF Scargle, JD Norris, J Bonnell, J BE Meegan, CA Preece, RD Koshut, TM TI Attributes of GRB pulses: Bayesian Blocks analysis of TTE data; a microburst in GRB920229 SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB Bayesian Blocks is a new time series algorithm for detecting localized structures (spikes or shots), revealing pulse shapes, and generally characterizing intensity variations. It maps raw counting data into a maximum likelihood piecewise constant representation of the underlying signal. This bin-free method imposes no lower limit on measurable time scales. Applied to BATSE TTE data, it reveals the shortest known burst structure - a spike superimposed on the main burst in GRB920229 (BATSE trigger 1453), with rise and decay timescales approximate to few 100 mu s. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Scargle, JD (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 181 EP 185 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200036 ER PT S AU Palmer, DM Cline, TL Gehrels, N Hurley, K Kurczynski, P Madden, N Pehl, R Ramaty, R Seifert, H Teegarden, BJ AF Palmer, DM Cline, TL Gehrels, N Hurley, K Kurczynski, P Madden, N Pehl, R Ramaty, R Seifert, H Teegarden, BJ BE Meegan, CA Preece, RD Koshut, TM TI Spectra of GRB970228 from the transient gamma-ray spectrometer SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB Visible afterglow counterparts have now been detected for two GRBs (970228 and 970508) but are absent, with L-opt/L gamma ratios at least two orders of magnitude lower, for other GRBs, e.g., 970828. The causes of this variation are unknown. Any correspondence which could be discovered between the gamma-ray properties of a GRB and its L-opt/L gamma would be useful, both in determining the GRB mechanisms, and in allocating resources for counterpart searches and studies. This paper presents the gamma-ray spectra of GRB970228 as measured by the Transient Gamma-Ray Spectrometer and comments on characteristics of this GRB compared to others that do and do not have observable counterparts. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Palmer, DM (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 304 EP 308 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200060 ER PT S AU Harris, MJ Share, GH AF Harris, MJ Share, GH BE Meegan, CA Preece, RD Koshut, TM TI On the relative frequency of gamma-ray bursts with peaks in nu f(nu) above similar to 1 MeV SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB Instruments such as BATSE which trigger on GRB emissions at energies around 100 keV will miss some GRBs with very hard spectra. We searched > 9 yr of data from the SMM Gamma Ray Spectrometer for such GRBs. An earlier search in the 0.35-0.8 MeV band yielded 177 GRBs, but a search st 0.8-10 MeV found only 2 new ones. A careful examination of the threshold conditions for detecting 0.8-10 MeV events allowed us to calculate the frequency of GRBs as a function of the spectral peak in vf(v) ( burst hardness Ei). The frequency distribution (relative to H = 0.5 MeV) is approximately flat up to H 5 2 MeV but falls sharply for harder bursts (by a factor greater than or equal to 5). There is no large undiscovered population of 'MeV bursts'. C1 NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RP Harris, MJ (reprint author), NASA, Goddard Space Flight Ctr, USRA, Code 661, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 314 EP 318 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200062 ER PT S AU Kurczynski, P Palmer, D Seifert, H Teegarden, BJ Gehrels, N Cline, TL Ramaty, R Hurley, K Madden, NW Pehl, RH AF Kurczynski, P Palmer, D Seifert, H Teegarden, BJ Gehrels, N Cline, TL Ramaty, R Hurley, K Madden, NW Pehl, RH BE Meegan, CA Preece, RD Koshut, TM TI A search for spectral lines in gamma-ray bursts using TGRS SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB We present the results of an ongoing search for narrow spectral lines in gamma- ray burst data. TGRS, the Transient Gamma-Ray Spectrometer aboard the Wind satellite is a high energy-resolution Ge device. Thus it is uniquely situated among the array of space-based, burst sensitive instruments to look for line features in gamma-ray burst spectra. Our search strategy adopts a two tiered approach. An automated 'quick look' scan searches spectra for statistically significant deviations from the continuum. We analyzed all possible time accumulations of spectra as well as individual spectra for each burst. Follow-up analysis of potential line candidates uses model fitting with F-test and chi(2) tests for statistical significance. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kurczynski, P (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 324 EP 328 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200064 ER PT S AU Seifert, H Cline, TL Palmer, DM Ramaty, R Teegarden, BJ Hurley, K Madden, NW Pehl, RH AF Seifert, H Cline, TL Palmer, DM Ramaty, R Teegarden, BJ Hurley, K Madden, NW Pehl, RH BE Meegan, CA Preece, RD Koshut, TM TI Spectroscopy of bright bursts with the transient gamma-ray spectrometer (TGRS) SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB The Transient Gamma-Ray Spectrometer (TGRS) on the WIND spacecraft is designed to perform spectroscopy of bright gamma-ray bursts (GRBs) in the similar to 20-8000 keV energy range, with a spectroscopic resolution which is 5-30 times better than that of earlier-generation detectors. During its first similar to 2.5 years of operation, TGRS detected similar to 90 GRBs, of which about one third are suitable for statistically interesting spectroscopy. We present preliminary comparative results for some of the brightest of those bursts, and which were also observed by CGRO/BATSE. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Seifert, H (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 339 EP 343 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200067 ER PT S AU Takeshima, T Marshall, FE Corbet, RHD Cannizzo, JK Valinia, A Swank, JH Barthelmy, SD Robinson, CR Kouveliotou, C Connaughton, V Kippen, RM Pendleton, G Murakami, T Yoshida, A Kawai, N Smith, DA Levine, AM Remillard, RA Hurley, K AF Takeshima, T Marshall, FE Corbet, RHD Cannizzo, JK Valinia, A Swank, JH Barthelmy, SD Robinson, CR Kouveliotou, C Connaughton, V Kippen, RM Pendleton, G Murakami, T Yoshida, A Kawai, N Smith, DA Levine, AM Remillard, RA Hurley, K BE Meegan, CA Preece, RD Koshut, TM TI RXTE quick response observations of afterglows from GRBs SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB In collaboration with the BATSE, ASCA, and RXTE/ASM teams, RXTE/PCA has been making quick response observations or GRB afterglows since June 1997. Two X-ray afterglows mere detected from the RXTE/PCA observations of GRB970616 and GRB970828. In this paper, we present our procedures and strategy for quick response observations and the results. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Takeshima, T (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Barthelmy, Scott/D-2943-2012 NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 414 EP 419 PG 6 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200080 ER PT S AU Strohmayer, TE Fenimore, EE Murakami, T Yoshida, A AF Strohmayer, TE Fenimore, EE Murakami, T Yoshida, A BE Meegan, CA Preece, RD Koshut, TM TI X-ray spectral properties of gamma-ray bursts SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB We summarize the spectral characteristics of a sample of 22 bright gamma-ray bursts detected with the y-ray burst sensors aboard the satellite Ginga. This instrument employed a proportional and scintillation counter to provide sensitivity to photons in the 2 - 400 keV range, providing a unique opportunity to characterize the largely unexplored X-ray properties of gamma-ray bursts. The photon spectra of the Ginga bursts are well described by a low-energy slope, a bend energy, and a high-energy slope. In the energy range where they can be compared, this result is consistent with burst spectral analyses obtained from the BATSE experiment aboard the Compton Observatory. However, below 20 keV we find evidence for a,positive spectral number index in approximately 40% of our burst sample, with some evidence for ir. strong rolloff at lower energies in a few events. We find that the distribution of spectral bend energies extends below 10 keV. The observed ratio of energy emitted in the X-rays relative to the gamma-rays can be much larger than a few percent and, in fact, is sometimes larger than unity. The average for our sample is 24%. C1 NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Strohmayer, TE (reprint author), NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 461 EP 465 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200089 ER PT S AU Baring, MG Harding, AK AF Baring, MG Harding, AK BE Meegan, CA Preece, RD Koshut, TM TI Spectral properties of gamma-ray bursts in the 1 GeV 1 TeV range SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB The properties of gamma-ray burst spectra in the 1 GeV - 1 TeV range may elucidate our understanding of these sources. If bursts are indeed at cosmological distances, it is indisputable that they possess relativistic bulk motion with large Lorentz factors. Calculations of pair production transparency in bursts usually assume an infinite power-law source spectrum for simplicity. However, photons above the EGRET range can potentially interact with sub-MeV photons in such calculations. The observed breaks and spectral curvature seen by BATSE around 1 MeV in many bursts is thus important to include in the pair opacity internal to the source. We present our recent determinations of gamma-ray burst pair opacity using such non-power law spectral forms. The comparative depletion of photons below 1 MeV can generate broad absorption troughs (corresponding to significant opacity) in the 1 GeV - 1 TeV range for sources located in the galactic halo. These distinctive signatures can differentiate between a cosmological or galactic origin of a given source. For cosmological bursts, spectral turnovers in the super-GeV range are possible, with their shape depending on source parameters, notably the distribution of photons within the source. Instruments like INTEGRAL, GLAST, Whipple and MILAGRO will play an important role in discriminating between these possibilities. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Baring, MG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Harding, Alice/D-3160-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 732 EP 736 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200139 ER PT S AU Bonnell, JT Norris, JP Dingus, BL Scargle, JD AF Bonnell, JT Norris, JP Dingus, BL Scargle, JD BE Meegan, CA Preece, RD Koshut, TM TI Simulated observations of gamma-ray bursts with GLAST SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB The Gamma-ray Large Area Space Telescope (GLAST) will incorporate high sensitivity, large field of view, and precision tracker technology, providing arc-minute localizations of gamma-rag bursts (GRBs) and exploring GRB physics up to similar to 100 GeV. We have simulated the response of GLAST to GRBs with power-law spectra extending to GeV energies to determine the detailed burst localization capability. The simulated properties of GR.Bs are based on the BATSE peak flux and duration distributions. GLAST's hodoscopic calorimeter design has sufficiently good angular resolution and discrimination power against cosmic rays that > I GeV gammas which are only detected in the calorimeter may be utilized for bright sources such as GRBs Our results indicate that GLAST will detect and image similar to 230 GRBs yr(-1) with sensitivity to similar to 100 GeV for similar to 20 bursts yr(-1) Many bright burst localizations will Le comparable in size to the current InterPlanetary Network error boxes thus probing thr cosmological burst parameter space at nearby redshifts and enabling counterpart searches at all lower energies. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bonnell, JT (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 884 EP 888 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200170 ER PT S AU Mahoney, WA Corbel, S Durouchoux, P Higdon, JC Ressler, ME Wallyn, P AF Mahoney, WA Corbel, S Durouchoux, P Higdon, JC Ressler, ME Wallyn, P BE Meegan, CA Preece, RD Koshut, TM TI Mid-infrared spectra of SGR 1806-20 and SGR 1900+14 SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB Two of the three known soft gamma repeaters, SGR 1806-20 and SGR 1900+14, have a fairly small angular separation and are visible from Mt. Palomar. During the nights of 21-23 June 1997 we observed both in the mid-infrared using SpectroCam-10 on the 5-meter Hale telescope. We obtained excellent images of the counterpart to SGR 1900+ 14 in 6 bands using narrow filters :(Delta lambda similar to 1 mu m) from approximately 8 to 13 mu m. The intensities in these 6 bands, summed over the two star-like components of the suspected counterpart, were all similar to 2-3 Jy and together yielded the first mid-infrared spectrum of this object. A spectrum of the SGR 1806-20 counterpart was also obtained, but it displayed a significantly different shape and showed a source intensity of only similar to 0.1 Jy. When combined with near-infrared and IRAS observations, the spectra imply that the counterparts of both SGRs consist of multiple components at different temperatures. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mahoney, WA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,169-327, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 931 EP 935 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200179 ER PT S AU Strohmayer, TE Ibrahim, A AF Strohmayer, TE Ibrahim, A BE Meegan, CA Preece, RD Koshut, TM TI X-ray spectroscopy of bursts from SGR1806-20 with RXTE SO GAMMA-RAY BURSTS, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Huntsville Gamma-Ray Burst Symposium CY SEP 15-20, 1997 CL HUNTSVILLE, AL SP Univ Space Res Assoc AB We report on new Rossi X-ray Timing Explorer (RXTE) X-ray spectral analysis of bursts from SGR1806-20, the most ?prolific SGR source known. Previous studies of bursts from this source noted the remarkable lack of spectral variability, both in single bursts as well as from burst to burst. Although we find that the spectrum both within and among bursts is quite uniform; we do find evidence for significant spectral changes within bursts as well as from burst to burst. We find that optically thin thermal bremsstrahlung spectra (OTTB), including photoelectric absorption, provide the best fits to most bursts, however, other models (power law, Band GRB model) can also produce statistically acceptable fits. We confirm the existence of a rolloff in the photon number spectrum below 5 keV. When modelled as photoelectric absorption and OTTB the inferred column is between 0.8 - 1.2 x 10(23) cm(-2). This value is larger than the approximate to 0.6 x 10(23) cm(-2) inferred from ASCA observations of the persistent X-ray counterpart, but less than the approximate to 10.0 x 10(23) cm(-2) indicated by ICE data. C1 NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Strohmayer, TE (reprint author), NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RI Ibrahim, Alaa/A-6250-2008 OI Ibrahim, Alaa/0000-0002-8791-7270 NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-766-9 J9 AIP CONF PROC PY 1998 IS 428 BP 947 EP 951 PG 5 WC Astronomy & Astrophysics; Remote Sensing SC Astronomy & Astrophysics; Remote Sensing GA BL28Z UT WOS:000075012200183 ER PT J AU Laymon, C Quattrochi, D Malek, E Hipps, L Boettinger, J McCurdy, G AF Laymon, C Quattrochi, D Malek, E Hipps, L Boettinger, J McCurdy, G TI Remotely-sensed regional-scale evapotranspiration of a semi-arid Great Basin desert and its relationship to geomorphology, soils, and vegetation SO GEOMORPHOLOGY LA English DT Article DE evapotranspiration; energy balance; surface flux; Landsat; thematic mapper; semi-arid desert ID SURFACE-ENERGY BALANCE; SENSIBLE HEAT-FLUX; LANDSAT THEMATIC MAPPER; THERMAL-INFRARED DATA; NET-RADIATION; EVAPO-TRANSPIRATION; METEOROLOGICAL DATA; RANGELAND BASIN; SATELLITE DATA; SPECTRAL DATA AB Landsat thematic mapper data are used to estimate instantaneous regional-scale surface water and energy fluxes in a semi-arid Great Basin desert of the western United States. Results suggest that it is possible to scale from point measurements of environmental state variables to regional estimates of water and energy exchange, This research characterizes the unifying thread in the classical climate-topography-soil-vegetation relation -the surface water and energy balance-through maps of the partitioning of energy throughout the landscape. The study was conducted in Goshute Valley of northeastern Nevada, which is characteristic of most faulted graben valleys of the Basin and Range Province of the western United States. The valley comprises a central playa and lake plain bordered by alluvial fans emanating from the surrounding mountains. The distribution of evapotranspiration (ET) is lowest in the middle reaches of the fans where the water table is deep and plants are small, resulting in low evaporation and transpiration. Highest ET occurs in the center of the valley, particularly in the playa, where limited to no vegetation occurs, but evaporation is relatively high because of a shallow water table and silty clay soil capable of large capillary movement. Intermediate values of ET are associated with large shrubs and is dominated by transpiration. (C) 1998 Elsevier Science B.V. C1 Inst Global Change Res & Educ, Global Hydrol & Climate Ctr, Huntsville, AL 35806 USA. NASA, Marshall Space Flight Ctr, Global Hydrol & Climate Ctr, Huntsville, AL 35806 USA. Utah State Univ, Dept Plants Soils & Biometeorol, Logan, UT 84322 USA. Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. RP Inst Global Change Res & Educ, Global Hydrol & Climate Ctr, 977 Explorer Blvd, Huntsville, AL 35806 USA. EM charles.laymon@msfc.nasa.gov OI Hipps, Lawrence/0000-0002-7658-8571 NR 73 TC 15 Z9 16 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X EI 1872-695X J9 GEOMORPHOLOGY JI Geomorphology PD JAN PY 1998 VL 21 IS 3-4 BP 329 EP 349 DI 10.1016/S0169-555X(97)00072-X PG 21 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA YN535 UT WOS:000071178300011 ER PT J AU McComas, DJ Bame, SJ Barraclough, BL Feldman, WC Funsten, HO Gosling, JT Riley, P Skoug, R Balogh, A Forsyth, R Goldstein, BE Neugebauer, M AF McComas, DJ Bame, SJ Barraclough, BL Feldman, WC Funsten, HO Gosling, JT Riley, P Skoug, R Balogh, A Forsyth, R Goldstein, BE Neugebauer, M TI Ulysses' return to the slow solar wind SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LATITUDES AB After ten long years of wandering the uncharted seas, Ulysses returned to his home port of Ithaca. Similarly, after its unprecedented five year odyssey through the previously uncharted regions over the poles of the Sun, the Ulysses spacecraft has returned to the slow, variable solar wind which dominates observations near the ecliptic plane. Solar wind plasma and magnetic field observations from Ulysses are used to examine this return from the fast polar solar wind through the region of solar wind variability and into a region of slow solar wind from the low latitude streamer belt. As it journeyed equatorward, Ulysses encountered a large corotating interaction region and associated rarefaction region on each solar rotation. Due to these repeated interactions, Ulysses also observed numerous shocks, all of which have tilts that are consistent with those expected for shocks generated by corotating interaction regions. Eventually, Ulysses emerged into a region of unusually steady slow solar wind, indicating that the tilt of the streamer belt with respect to the solar heliographic equator was smaller than the width of the band of slow solar wind from the streamer belt. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP McComas, DJ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Funsten, Herbert/A-5702-2015 OI Funsten, Herbert/0000-0002-6817-1039 NR 15 TC 150 Z9 153 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 1 PY 1998 VL 25 IS 1 BP 1 EP 4 DI 10.1029/97GL03444 PG 4 WC Geosciences, Multidisciplinary SC Geology GA YQ302 UT WOS:000071371700001 ER PT J AU Brinksma, EJ Meijer, YJ McDermid, IS Cageao, RP Bergwerff, JB Swart, DPJ Ubachs, W Matthews, WA Hogervorst, W Hovenier, JW AF Brinksma, EJ Meijer, YJ McDermid, IS Cageao, RP Bergwerff, JB Swart, DPJ Ubachs, W Matthews, WA Hogervorst, W Hovenier, JW TI First lidar observations of mesospheric hydroxyl SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OH; OZONE; MODEL; STATE AB Ground-based lidars have been used to detect and identify ground-state (v "=0) hydroxyl radicals (OH) in the mesosphere between about 75 and 85 km altitude. These lidars operate near 308 nm and OH is observed through laser-induced-fluorescence on the A(2) Sigma(+)-X-2 Pi(0, 0) band. The results expose a valuable global set of nighttime OH observations, since existing long-term lidar data at several NDSC sites contain the (serendipitous) OH information. Results of lidar observations are presented from two mid-latitude sites, one in each hemisphere: Table Mountain (34 degrees N), California, and Lauder (45 degrees S), New Zealand. They show observations of a geometrically thin (similar to 3 km) nocturnal layer of OH near 80 km. For the Table Mountain observations, the derived values for the OH density at 80 km typically are 2 - 4 x 10(5) cm(-3) which is in accordance with model predictions [Dodd et al., 1994]. The temporal behavior of the mesospheric OH signal, following sunset; that was found, supports previous model predictions [Alien et al., 1984] in a qualitative fashion. C1 Free Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands. CALTECH, Jet Prop Lab, Table Mt Facil, Wrightwood, CA 92397 USA. Natl Inst Publ Hlth & Environm, Air Res Lab, NL-3720 BA Bilthoven, Netherlands. Natl Inst Water & Atmospher Res Ltd, Lauder, New Zealand. RP Brinksma, EJ (reprint author), Free Univ Amsterdam, Dept Phys & Astron, De Boelelaan 1081, NL-1081 HV Amsterdam, Netherlands. RI Ubachs, Wim/F-5649-2011 OI Ubachs, Wim/0000-0001-7840-3756 NR 15 TC 10 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 1 PY 1998 VL 25 IS 1 BP 51 EP 54 DI 10.1029/97GL53561 PG 4 WC Geosciences, Multidisciplinary SC Geology GA YQ302 UT WOS:000071371700015 ER PT J AU Ho, CH Chou, MD Suarez, M Lau, KM AF Ho, CH Chou, MD Suarez, M Lau, KM TI Effect of ice cloud on GCM climate simulations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIATIVE PROPERTIES; PARAMETERIZATION; MODEL AB The effect of the interaction of SW (shortwave, solar) radiation with ice clouds on climate simulations is studied using the GEOS (Goddard Earth Observing System) climate GCM (general circulation model) coupled with an ocean mixed-layer model. Due to much larger cloud particles, the single-scattering co-albedo of ice clouds is nearly ten times larger than that of water clouds, but the asymmetry factor is generally smaller. Offline calculations with a radiative transfer model show that inclusion of the ice cloud effect increases SW absorption in the upper troposphere and decreases the SW flux at the surface. For the earth-atmosphere system, the change in the SW absorption is small due to compensation of the co-albedo and asymmetry factor effects. The effect of ice clouds tends to increase the atmospheric stability by enhancing SW heating in the upper troposphere and reducing SW heating in the lower troposphere and at the surface. The GCM experiments demonstrate that the inclusion of ice clouds produces colder surface temperature, and leads to reduction in SW heating of the earth-atmosphere system associated with changes in surface albedo and in cloud distribution. The enhanced atmospheric stability leads to decreased high cloud amount by a maximum of 80% and to increased middle cloud by a maximum of 60% over the tropics. C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland, NASA, Joint Ctr Earth Syst Sci, Dept Meteorol, College Pk, MD 20742 USA. RP Ho, CH (reprint author), NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Atmospheres Lab, Greenbelt, MD 20771 USA. RI Ho, Chang-Hoi/H-8354-2015 NR 9 TC 17 Z9 17 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 1 PY 1998 VL 25 IS 1 BP 71 EP 74 DI 10.1029/97GL03356 PG 4 WC Geosciences, Multidisciplinary SC Geology GA YQ302 UT WOS:000071371700020 ER PT J AU Pinelli, TE Barclay, RO AF Pinelli, TE Barclay, RO TI Maximizing the results of federally-funded research and development through knowledge management: A strategic imperative for improving US competitiveness SO GOVERNMENT INFORMATION QUARTERLY LA English DT Article ID TECHNOLOGY AB Federally-funded research and development (R&D) represents a significant annual investment (approximately $79 billion in fiscal year 1996) on the part of U.S. taxpayers. Based on the results of a 10-year study of knowledge diffusion in the U.S. aerospace industry, the authors take the position that U.S. competitiveness will be enhanced if knowledge management strategies, employed within a capability-enhancing U.S. technology policy framework, are applied to diffusing the results of federally-funded R&D. In making their case, the authors stress the importance of knowledge as the sourer of competitive advantage in today's global economy. Next, they offer a practice-based definition of knowledge management and discuss three current approaches to knowledge management implementation-mechanistic, "the learning organization," and systemic. The authors then examine three weaknesses in existing U.S. public policy and policy implementation-the dominance of knowledge creation, the need for diffusion-oriented technology policy, and the prevalence of a dissemination model-that affect diffusion of the results of federally-funded R&D. To address these shortcomings, they propose the development of a knowledge management framework for diffusing the results of Federally-funded R&D. The article closes with a discussion of some issues and challenges associated with implementing a knowledge management framework for diffusing the results of federally-funded R&D. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Knowledge Management Associates Inc, Portsmouth, VA 23704 USA. RP Pinelli, TE (reprint author), NASA, Langley Res Ctr, Mail Stop 400, Hampton, VA 23681 USA. NR 58 TC 3 Z9 3 U1 0 U2 3 PU JAI PRESS INC PI STAMFORD PA 100 PROSPECT ST, PO BOX 811, STAMFORD, CT 06901 USA SN 0740-624X J9 GOV INFORM Q JI Gov. Inf. Q. PY 1998 VL 15 IS 2 BP 157 EP 172 DI 10.1016/S0740-624X(98)90041-7 PG 16 WC Information Science & Library Science SC Information Science & Library Science GA ZT976 UT WOS:000074148200002 ER PT S AU Coriell, SR Murray, BT Chernov, AA McFadden, GB AF Coriell, SR Murray, BT Chernov, AA McFadden, GB BE Andrews, JB Alexander, JID TI The effect of a shear flow on the morphological stability of a vicinal face: Growth from a supersaturated solution SO GRAVITATIONAL EFFECTS IN FLUID AND MATERIALS SCIENCE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT G0 1 Symposium of COSPAR Scientific-Commission-G on Gravitational Effects in Fluid and Materials Science at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Int Council Sci Unions, Comm Space Res, UN, Off Outer Space Affairs ID KINETIC SELF-STABILIZATION; STEPPED INTERFACE; BINARY ALLOY; SOLIDIFICATION; MELT AB The effect of a parallel shear flow and anisotropic interface kinetics on the onset of instability during growth from a supersaturated solution is analyzed. The model used for anisotropy is based on the microscopic picture of step motion. A shear flow (linear Couette flow or asymptotic suction profile) parallel to the crystal-solution interface in the same direction as the step motion decreases interface stability. A shear how counter to the step motion enhances stability and for sufficiently large shear rates the interface is absolutely morphologically stable. For large wave numbers, the perturbed flow field can be neglected and a simple analytic approximation for the stability-instability demarcation is found. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Space Res Assoc, Huntsville, AL 35806 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35806 USA. RP Coriell, SR (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 17 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043472-X J9 ADV SPACE RES PY 1998 VL 22 IS 8 BP 1153 EP 1158 DI 10.1016/S0273-1177(98)00158-6 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Mechanics; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Mechanics; Meteorology & Atmospheric Sciences GA BL84P UT WOS:000076921000001 ER PT S AU Kamotani, Y Ostrach, S Pline, A AF Kamotani, Y Ostrach, S Pline, A BE Andrews, JB Alexander, JID TI Some temperature field results from the thermocapillary flow experiment aboard USML-2 spacelab SO GRAVITATIONAL EFFECTS IN FLUID AND MATERIALS SCIENCE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT G0 1 Symposium of COSPAR Scientific-Commission-G on Gravitational Effects in Fluid and Materials Science at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Int Council Sci Unions, Comm Space Res, UN, Off Outer Space Affairs ID CONVECTION EXPERIMENT; MICROGRAVITY AB Some temperature field results are reported of the thermocapillary flow experiments conducted on board the Space Shuttle. In the experiments oscillatory thermocapillary flows were investigated in cylindrical containers filled with silicone oil. Three different container diameters and two types of heating mode were used to study their effects on the oscillation phenomenon. An infrared imaging system recorded the oil surface temperature. A movable thermistor probe measured the fluid temperature. Numerical analysis was also performed to supplement the experiments. The results from those measurements and the analysis are presented and discussed herein. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 Case Western Reserve Univ, Cleveland, OH 44106 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Kamotani, Y (reprint author), Case Western Reserve Univ, Cleveland, OH 44106 USA. NR 5 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043472-X J9 ADV SPACE RES PY 1998 VL 22 IS 8 BP 1189 EP 1195 DI 10.1016/S0273-1177(98)00147-1 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Mechanics; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Mechanics; Meteorology & Atmospheric Sciences GA BL84P UT WOS:000076921000006 ER PT S AU Rogers, MJB Hrovat, K Moskowitz, M AF Rogers, MJB Hrovat, K Moskowitz, M BE Andrews, JB Alexander, JID TI Low-gravity environment of the Mir Space Station SO GRAVITATIONAL EFFECTS IN FLUID AND MATERIALS SCIENCE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT G0 1 Symposium of COSPAR Scientific-Commission-G on Gravitational Effects in Fluid and Materials Science at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Int Council Sci Unions, Comm Space Res, UN, Off Outer Space Affairs AB The NASA Lewis Research Center's Space Acceleration Measurement System is being used to record the low-gravity environment of the Mir Space Station. Approximately 220 hours of non-continuous data were collected between October 1994 and November 1995 in the Kristall and Kvant-1 modules. Acceleration data were collected on Mir during the STS-74 docking. Two data analysis techniques are introduced and the results of extensive data analyses are summarized. Transient and oscillatory accelerations recorded on Mir are generally produced by vehicle subsystem operations, experiment operations, and crew activity. In looking at oscillatory disturbances in the acceleration spectrum from about 0.01 Hz to 250 Hz, we see that crew exercise (1 to 4 Hz with broadband excitation from 10 to 40 Hz) and structural modes (0.3 to 2 Hz) contribute the most energy below 5 Hz. From 10 Hz to 100 Hz, vehicle subsystems (water pump at 24 Hz and harmonics, air circulation system at 51 Hz) and several significant unknowns, particularly in the 40 to 90 Hz range, are the principal sources of disturbance. Above 100 Hz, strong contributors (ie at 102 Hz lair circulation system harmonic), 120 Hz (water pump harmonic), and 140 Hz (unknown). Gyrodyne operation can be seen at about 166.7 Hz (10,000 rpm). The microgravity environment of Mir is similar to the NASA Space Shuttle Orbiters except that the Mir structural modes are at lower frequencies and there appear to be more subsystem vibration sources on the larger, more complex Mir structure. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Lewis Res Ctr, PIMS Tal Cut, Cleveland, OH 44135 USA. RP Rogers, MJB (reprint author), NASA, Lewis Res Ctr, PIMS Tal Cut, MS 500-216, Cleveland, OH 44135 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043472-X J9 ADV SPACE RES PY 1998 VL 22 IS 8 BP 1257 EP 1260 DI 10.1016/S0273-1177(98)00156-2 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Mechanics; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Mechanics; Meteorology & Atmospheric Sciences GA BL84P UT WOS:000076921000018 ER PT S AU Kia, T Mellstrom, J Klumpp, A Lin, HS Sanatar, P Shen, K Vaze, P Nachman, M AF Kia, T Mellstrom, J Klumpp, A Lin, HS Sanatar, P Shen, K Vaze, P Nachman, M BE Culp, RD Igli, DA TI TOPEX/POSEIDON Autonomous Maneuver Experiment (TAME) in-flight execution SO GUIDANCE AND CONTROL 1998 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT Annual American-Astronautical-Society Rocky Mountain Guidance and Control Conference CY FEB 04-08, 1998 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB Autonomous spacecraft are becoming increasingly important for future space missions. Missions will continue to become more ambitious scientifically, and will demand more autonomy to accomplish complex tasks in uncertain environments and in close proximity to celestial bodies. Affordability is now an additional primary driver. The call is for smaller missions with greatly reduced ground control and operation. Spacecraft with highly autonomous, goal-directed systems are required. We believe that autonomy, in addition to reducing mission operations costs, will enable science objectives not currently possible. Autonomous maneuver planning and implementation is a key to future missions. The TOPEX/POSEIDON Autonomous Maneuver Experiment (TAME) is an experiment to provide the necessary algorithms for planning and executing attitude maneuvers and a thrusting Orbital Maintenance Maneuver (OMM) autonomously. TAME's main module is the planner, an engine that, along with its auxiliary modules and a database, will reside on an existing satellite processor. The database contains certain satellite and orbit constants, as well as tables of mission constraints. Upon receiving an OMM command, the planner requests up-to-date propulsion data from the satellite's main On-Board Computer (OBC), and then designs an attitude maneuver that does not violate any constraint, geometric, power, or thermal. Another module, the sequence generator, incorporates the generated path into an OMM sequence that avoids violating other types of constraints, such as the timing and order of commands. The resulting command sequence, which includes commands for reconfiguring and conditioning the satellite and its components, is transmitted to the OBC for execution. This paper describes the planning and execution phases of the experiment. The paper presents results obtained from the flight experiment, and shares lessons learned, TAME was executed, in flight, for the first time November 1997. During the first flight, TAME planned a violation-free maneuver and generated an executable sequence. The second time it will, in addition, transmit the generated sequence to the OBC, but the sequence will not be executed. The third and the final time, a normal OMM will be planned, transmitted to the OBC, and executed. The remaining two flight executions are planned for the spring of 1998. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kia, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-448-6 J9 ADV ASTRONAUT SCI PY 1998 VL 98 BP 3 EP 19 PG 17 WC Engineering, Aerospace SC Engineering GA BL44R UT WOS:000075547000001 ER PT S AU Dukeman, GA Gallagher, MW AF Dukeman, GA Gallagher, MW BE Culp, RD Igli, DA TI Guidance and control concepts for the X-33 technology demonstrator SO GUIDANCE AND CONTROL 1998 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT Annual American-Astronautical-Society Rocky Mountain Guidance and Control Conference CY FEB 04-08, 1998 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB The X-33 technology demonstrator is a suborbital precursor to the Reusable Launch Vehicle (RLV) with first flight planned for summer of 1999. The flight test program will include about 15 fights originating from Edwards Air Force Base, California, each with widely varying flight profiles in order to test new thermal protection system (TPS) materials, structures, and linear aerospike engines. The first flights will be relatively short range flights with about a 370 nmi range, maximum Mach number of 10, maximum altitude of 190,000 feet, whereas the latter flights will cover about 800 nmi range, with maximum altitude of about 260,000 feet and maximum Mach of about 15. The guidance algorithms must be flexible enough to accommodate these various profiles and to adapt to severe off-nominal dispersions, such as early engine failure (partial or total) where possibly more than half the thrust is lost. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Dukeman, GA (reprint author), NASA, George C Marshall Space Flight Ctr, MS,ED13, Huntsville, AL 35812 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-448-6 J9 ADV ASTRONAUT SCI PY 1998 VL 98 BP 287 EP 306 PG 20 WC Engineering, Aerospace SC Engineering GA BL44R UT WOS:000075547000018 ER PT S AU Watzin, JG AF Watzin, JG BE Culp, RD Igli, DA TI SMEX center dot Lite: NASA's next generation Small Explorer SO GUIDANCE AND CONTROL 1998 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT Annual American-Astronautical-Society Rocky Mountain Guidance and Control Conference CY FEB 04-08, 1998 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB High space mission costs continue to be a major problem for the aerospace community. The National Aeronautics and Space Administration (NASA) Small Explorer (SMEX) Project has made great strides in reducing mission costs by implementing a building block architecture and streamlined mission operations. The project aims to substantially reduce both spacecraft and mission costs further through the introduction of advanced design tools and an advanced technology "function-sliced" architecture. Spacecraft autonomy will be extended such that classical mission operations will be eliminated altogether. This paper will describe the fundamental elements of the planned cost reduction and the "function-sliced" architecture as well as cite those elements of the original SMEX design that have proven to be beneficial. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Watzin, JG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-448-6 J9 ADV ASTRONAUT SCI PY 1998 VL 98 BP 389 EP 403 PG 15 WC Engineering, Aerospace SC Engineering GA BL44R UT WOS:000075547000025 ER PT S AU Purcell, G Kuang, D Lichten, S Wu, SC Young, L AF Purcell, G Kuang, D Lichten, S Wu, SC Young, L BE Culp, RD Igli, DA TI Autonomous formation flyer (AFF) sensor technology development SO GUIDANCE AND CONTROL 1998 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT Annual American-Astronautical-Society Rocky Mountain Guidance and Control Conference CY FEB 04-08, 1998 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB The DS-3 mission will demonstrate various elements of the technology required for space interferometry, including Autonomous Formation Flying (AFF). It will consist of three spacecraft, each having a degree of autonomy but all comprising a single instrument and constrained to move together at the vertices of an equilateral triangle with sides of 100 to 1000 m. In order to meet the mission's goals, AFF must maintain the distances between spacecraft within 1 cm and the relative orientations of the spacecraft within 1 arcminute per axis. This paper proposes an implementation of AFF that borrows technology from the Global Positioning System (GPS), using measurements of both r-f carrier phase and a ranging code. Each spacecraft wilt have at least one transmitting antenna and three receiving antennas, operating at 30 GHz with a code rate of 100 Mchips/second. To validate the proposed scheme, two sets of covariance analyses have been performed, using batch and sequential processing. Both analyses suppose measurement errors of 1 cm on the ranges and 10 mu m on the phases, but they process the data differently and make somewhat different assumptions about the nature of systematic errors. Nevertheless, the two analyses reach similar results, concluding that with careful calibration the mission requirements can be met by measurements of the specified accuracy. The paper also summarizes various aspects of the proposed implementation that have not been entirely worked out, indicating in general terms how each might be handled and what problems remain to be solved, These problems include initialization, the location and beam shape of the antennas, multipath, systematic measurement errors, and the effect of the local transmitter on received signals. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Purcell, G (reprint author), CALTECH, Jet Prop Lab, MS 238-600,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-448-6 J9 ADV ASTRONAUT SCI PY 1998 VL 98 BP 463 EP 481 PG 19 WC Engineering, Aerospace SC Engineering GA BL44R UT WOS:000075547000031 ER PT S AU Lundquist, R Sabelhaus, P Scott, SS Holmes, EB AF Lundquist, R Sabelhaus, P Scott, SS Holmes, EB BE Culp, RD Igli, DA TI The importance and difficulty of attitude control system (ACS) phase and polarity testing: Lessons learned from TOMS-EP early orbital operations SO GUIDANCE AND CONTROL 1998 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT Annual American-Astronautical-Society Rocky Mountain Guidance and Control Conference CY FEB 04-08, 1998 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB Launch and early orbital operations of the Total Ozone Mapping Spectrometer - Earth Probe (TOMS-EP) Spacecraft in July 1996 uncovered two correctable Attitude Control and Determination Subsystem (ACDS) phasing/polarity errors that were not detected during the satellite ground testing program, One of these errors was the relative location of two of the four coarse sun sensors (CSS's) on the solar arrays, These sensors are used during safe hold/safe power modes to locate and point the satellite toward the sun, The second error was polarity reversal of the three magnetic torquer assemblies (MTA's), Due to the nature of these sensors, their relationship to and use in the satellite system, their interactions with the flight software attitude control laws, and their installation and system test plans, these phasing/polarity errors were not detected until after launch, The TOMS-EP system design was robust enough to survive these phasing/polarity errors and it permitted software modifications and operational changes to correct or accommodate the phasing/polarity errors, This paper will describe the TOMS-EP phasing/polarity errors and the related system consequences, The TOMS-EP ACS design, ground test program and philosophy will be described, Lessons learned from the TOMS-EP Integration and Testing program and from the anomaly recovery during orbital operations will be discussed, In addition, system architectures and implementations will be described, which adapt to or allow for phase reversals and corrections on orbit, Lessons learned from the TOMS-EP post launch anomalies that were applied to the Landsat 7 software architecture contains certain features that would expedite recovery from similar ACS phasing/polarity anomalies. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lundquist, R (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-448-6 J9 ADV ASTRONAUT SCI PY 1998 VL 98 BP 633 EP 653 PG 21 WC Engineering, Aerospace SC Engineering GA BL44R UT WOS:000075547000042 ER PT B AU Sweigart, AV Catelan, M AF Sweigart, AV Catelan, M BE Bradley, PA Guzik, JA TI On the production of bright RR Lyrae variables in metal-rich globular clusters SO HALF CENTURY OF STELLAR PULSATION INTERPRETATIONS: A TRIBUTE TO ARTHUR N. COX SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on a Half Century of Stellar Pulsation Interpretations CY JUN 16-20, 1997 CL LOS ALAMOS, NM C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sweigart, AV (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-55-4 J9 ASTR SOC P PY 1998 VL 135 BP 39 EP 40 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK82C UT WOS:000073481200008 ER PT B AU Catelan, M Sweigart, AV Borissova, J AF Catelan, M Sweigart, AV Borissova, J BE Bradley, PA Guzik, JA TI RR Lyrae variables in globular clusters and the second-parameter phenomenon SO HALF CENTURY OF STELLAR PULSATION INTERPRETATIONS: A TRIBUTE TO ARTHUR N. COX SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on a Half Century of Stellar Pulsation Interpretations CY JUN 16-20, 1997 CL LOS ALAMOS, NM AB We propose to use RR Lyrae variables in globular clusters (GC's) to probe the origin of the second-parameter phenomenon. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Catelan, M (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 0 TC 13 Z9 13 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-55-4 J9 ASTR SOC P PY 1998 VL 135 BP 41 EP 42 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK82C UT WOS:000073481200009 ER PT S AU Ding, CHQ Lyster, PM Larson, JW Guo, J da Silva, A AF Ding, CHQ Lyster, PM Larson, JW Guo, J da Silva, A BE Sloot, P Bubak, M Hertzberger, B TI Atmospheric data assimilation on distributed-memory parallel supercomputers SO HIGH-PERFORMANCE COMPUTING AND NETWORKING SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT International Conference and Exhibition on High-Performance Computing and Networking CY APR 21-23, 1998 CL AMSTERDAM, NETHERLANDS AB Atmospheric data such as temperature, moisture, winds, etc., collected by satellites and direct measuements from upper-air instruments, ground observation stations provide only partial information about the atmosphere. They are assimilated to numerical forecasts to provide a coherent, evolving state of the global atmosphere. The data analysis system, the Physical-space Statistical Analysis System (PSAS) developed at the Data Assimilation Office at NASA's Goddard Space Flight Center, requires computing resources far beyond the capabilities of even the state-of-the-art vector supercomputers. Here we describe an efficient and scalable implementation of the PSAS on distributed-memory massively parallel supercomputers such as Intel Paragon and Gray T3E; the implementations achieves superb performance as demonstrated by detailed performance analysis of systematic runs on up to 512 processors on Paragon, T3D and T3E. Consequently, the solution time is reduced to 24.6 seconds on 512-PE T3E from 5 hours on a single head of Gray C90 for a real problem of 80,000 observations, a 740-fold reduction of turn-around time. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA 94720 USA. Univ Maryland, Interdisciplinary Ctr Earth Syst Sci, College Pk, MD 20742 USA. Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20071 USA. RP Ding, CHQ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA 94720 USA. RI da Silva, Arlindo/D-6301-2012 OI da Silva, Arlindo/0000-0002-3381-4030 NR 6 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64443-1 J9 LECT NOTES COMPUT SC PY 1998 VL 1401 BP 115 EP 124 PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods; Medical Informatics SC Computer Science; Medical Informatics GA BM08P UT WOS:000077581300013 ER PT S AU Waheed, A Yan, J AF Waheed, A Yan, J BE Sloot, P Bubak, M Hertzberger, B TI Parallelization of NAS benchmarks for shared memory multiprocessors SO HIGH-PERFORMANCE COMPUTING AND NETWORKING SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT International Conference and Exhibition on High-Performance Computing and Networking CY APR 21-23, 1998 CL AMSTERDAM, NETHERLANDS AB This paper presents our experiences of parallelizing the sequential implementation of NAS benchmarks using compiler directives on SGI Origin2000 distributed shared memory (DSM) system. Porting existing applications to new high performance parallel and distributed computing platform is a challenging task. ideally a user develops a sequential version of the application, leaving the task of porting the code to parallelization tools and compilers. Due to the simplicity of programming shared-memory multiprocessors, compiler developers have provided various facilities to allow the users to exploit parallelism. Native compilers on SGI Origin2000 support multiprocessing directives to allow users to exploit loop-level parallelism in their programs. Additionally, supporting tools can accomplish this process automatically. We experimented with these compiler directives and supporting tools by parallelizing sequential implementation of NAS benchmarks. Results reported in this paper indicate that,with minimal effort, the performance gain is comparable with the hand-parallelized, carefully optimized, message-passing implementations of the same benchmarks. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Waheed, A (reprint author), NASA, Ames Res Ctr, Mail Stop T27A-2, Moffett Field, CA 94035 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64443-1 J9 LECT NOTES COMPUT SC PY 1998 VL 1401 BP 377 EP 386 PG 10 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods; Medical Informatics SC Computer Science; Medical Informatics GA BM08P UT WOS:000077581300039 ER PT S AU Campbell, JW Taylor, CR AF Campbell, JW Taylor, CR BE Phipps, CR TI Power beaming for orbital debris removal SO HIGH-POWER LASER ABLATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on High-Power Laser Ablation CY APR 26-30, 1998 CL SANTA FE, NM SP SPIE, Univ Illinois, Fus Studies Lab, NE Sci & Technol Inc, Photon Associates Inc, F2 Associates Inc AB Orbital debris in low-Earth orbit ranging in size from 1 to 10 cm in diameter can be detected but not tracked reliably enough to be easily avoided by spacecraft. In addition, shielding protection is extremely difficult and costly to accomplish for sizes above 1-2 cm. Debris in this size regime traveling at mean velocities on the order of 20000 miles per hour may cause catastrophic damage. Using adaptive optics technologies, a ground-based pulsed laser of sufficient power ablating the debris particle's surface to produce small momentum changes may, in several hundred pulses, lower a target debris particle's perigee sufficiently for atmospheric capture. A single laser facility could remove all of the 1-10 cm debris below 1500 km in altitude in approximately three years. A technology demonstration of ground based laser removal is proposed which would pave the way for the implementation of such a debris removal system. The cost of the proposed demonstration is comparable with the estimated annual cost of spacecraft operations in the present orbital debris environment. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Campbell, JW (reprint author), NASA, George C Marshall Space Flight Ctr, PS02,MSFC, Huntsville, AL 35812 USA. NR 0 TC 5 Z9 6 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2790-X J9 P SOC PHOTO-OPT INS PY 1998 VL 3343 BP 583 EP 589 DI 10.1117/12.321604 PG 7 WC Optics SC Optics GA BL80U UT WOS:000076793000060 ER PT B AU Zhu, DM Ghosn, LJ Miller, RA AF Zhu, DM Ghosn, LJ Miller, RA BE Hou, PY McNallan, MJ Oltra, R Opila, EJ Shores, DA TI Effect of layer-graded bond coats on edge stress concentration and oxidation behavior of thermal barrier coatings SO HIGH TEMPERATURE CORROSION AND MATERIALS CHEMISTRY, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on High Temperature Corrosion and Materials Chemistry at the 193rd Meeting of the Electrochemical Society CY MAY 03-08, 1998 CL SAN DIEGO, CA SP Electrochem Soc, High Temp Mat Div & Corros Div, High Temp Mat Chem, High Temp Mat Div DE thermal barrier coatings; high temperature oxidation; laser thermal gradient cycling; edge effect; finite element method AB Thermal barrier coating (TBC) durability is closely related to design, processing and microstructure of the coating systems. Two important issues that must be considered during the design of a thermal barrier coating are thermal expansion and modulus mismatch between the substrate and the ceramic layer, and substrate oxidation. In many cases, both of these issues may be best addressed through the selection of an appropriate bond coat system. In this study, a low thermal expansion and layer-graded bond coat system, that consists of plasma-sprayed FeCoNiCrAl and FeCrAlY coatings and a high velocity oxyfuel (HVOF) sprayed FeCrAlY coating, is developed to minimize the thermal stresses and provide oxidation resistance. The thermal expansion and oxidation behavior of the coating system are also characterized, and the strain isolation effect of the bond coat system is analyzed using the finite element method (FEM). Experiments and finite element results show that the layer-graded bond coat system possesses lower interfacial stresses, better strain isolation and excellent oxidation resistance, thus significantly improving the coating performance and durability. C1 NASA, Lewis Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. RP Zhu, DM (reprint author), NASA, Lewis Res Ctr, Ohio Aerosp Inst, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-203-6 J9 ELEC SOC S PY 1998 VL 98 IS 9 BP 170 EP 189 PG 20 WC Chemistry, Applied; Electrochemistry; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Electrochemistry; Materials Science; Metallurgy & Metallurgical Engineering GA BL90W UT WOS:000077109800016 ER PT B AU Smialek, JL AF Smialek, JL BE Hou, PY McNallan, MJ Oltra, R Opila, EJ Shores, DA TI Toward optimum scale and TBC adhesion on single crystal superalloys SO HIGH TEMPERATURE CORROSION AND MATERIALS CHEMISTRY, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on High Temperature Corrosion and Materials Chemistry at the 193rd Meeting of the Electrochemical Society CY MAY 03-08, 1998 CL SAN DIEGO, CA SP Electrochem Soc, High Temp Mat Div & Corros Div, High Temp Mat Chem, High Temp Mat Div AB Single crystal superalloys exhibit excellent cyclic oxidation resistance if their sulfur content is reduced from typical impurity levels of similar to 5 ppmw to below 0.5 ppmw. Excellent alumina scale adhesion was documented for PWA 1480 and PWA 1484 without yttrium additions. Hydrogen annealing produced effective desulfurization of PWA 1480 to less than or equal to 0.2 ppmw and was also used to achieve controlled intermediate levels. The direct relationship between cyclic oxidation behavior and sulfur content was shown. An adhesion criterion was proposed based on the total amount of sulfur available for interfacial segregation, e.g., less than or equal to 0.2 ppmw S will maximize adhesion for a 1 mm thick sample. PWA 1484, melt desulfurized to 0.3 ppmw S, also exhibited excellent cyclic oxidation resistance and encouraging TBC lives (10 mils of 8YSZ, plasma sprayed without a bond coat) in 1100 degrees C cyclic oxidation tests. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Smialek, JL (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 10 Z9 10 U1 0 U2 2 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-203-6 J9 ELEC SOC S PY 1998 VL 98 IS 9 BP 211 EP 220 PG 10 WC Chemistry, Applied; Electrochemistry; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Electrochemistry; Materials Science; Metallurgy & Metallurgical Engineering GA BL90W UT WOS:000077109800019 ER PT S AU Loewenstein, M Mushotzky, RF AF Loewenstein, M Mushotzky, RF BE Koyama, K Kitamoto, S Itoh, M TI Metal abundances in the hot ISM of elliptical galaxies SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Loewenstein, M (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 53 EP 56 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500012 ER PT S AU Swank, JH AF Swank, JH BE Koyama, K Kitamoto, S Itoh, M TI Millisecond time variations of X-ray binaries SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union AB Millisecond time-scales are natural for some neutron star and black hole processes, although possibly difficult to observe. The Rossi X-Ray Timing Explorer (RXTE) has found that for the neutron stars in low-mass X-ray binaries (LMXB) there are flux oscillations at high frequencies, with large amplitudes. Z sources and bursters tend to exhibit oscillations in the range 300-1200 Hz. Persistent emission may exhibit one or both of two features. In bursts from different bursters, a nearly coherent pulsation is seen, which may be the rotation period of the neutron star. For some the frequency equals the difference between the two higher frequencies, suggesting a beat frequency model, but in others it is twice the difference. The sources span two orders of magnitude in accretion rate, yet the properties are similar. The similar maximum frequencies suggests that it corresponds to the Kepler orbit frequency at the minimum stable orbit or the neutron star surface, either of which would determine the neutron star masses, radii and equation of state. Theories of accretion onto black holes predict a quasi-periodic oscillation (QPO) related to the inner accretion disk. The two microquasar black hole candidates (BHCs) have exhibited candidates for this or related frequencies. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Swank, JH (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 9 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 107 EP 110 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500025 ER PT S AU Thompson, DJ AF Thompson, DJ BE Koyama, K Kitamoto, S Itoh, M TI X-ray and gamma-ray observations of isolated neutron stars SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 187th Symposium of the International-Astronomical-Union CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union ID PULSARS C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Thompson, DJ (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RI Thompson, David/D-2939-2012 OI Thompson, David/0000-0001-5217-9135 NR 14 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 113 EP 116 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500027 ER PT S AU Petre, R Keohane, J Hwang, U Allen, G Gotthelf, E AF Petre, R Keohane, J Hwang, U Allen, G Gotthelf, E BE Koyama, K Kitamoto, S Itoh, M TI Search for nonthermal X-rays from supernova remnant shells SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union ID CASSIOPEIA-A; ACCELERATION; ELECTRONS C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Petre, R (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 11 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 117 EP 120 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500028 ER PT S AU Fishman, GJ AF Fishman, GJ BE Koyama, K Kitamoto, S Itoh, M TI Gamma-ray burst observations with BATSE SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. RP Fishman, GJ (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Code ES-81, Huntsville, AL 35812 USA. NR 10 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 159 EP 162 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500037 ER PT S AU Kouveliotou, C AF Kouveliotou, C BE Koyama, K Kitamoto, S Itoh, M TI A review of GRB counterpart searches SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union ID GAMMA-RAY BURST; OPTICAL COUNTERPART; AFTERGLOW; RADIO C1 Univ Space Res Assoc, NASA, MSFC, Huntsville, AL 35812 USA. RP Kouveliotou, C (reprint author), Univ Space Res Assoc, NASA, MSFC, ES-84, Huntsville, AL 35812 USA. NR 33 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 167 EP 170 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500039 ER PT S AU Inoue, H Takahashi, T Ueda, Y Yamashita, A Ishisaki, Y Ogasaka, Y AF Inoue, H Takahashi, T Ueda, Y Yamashita, A Ishisaki, Y Ogasaka, Y BE Koyama, K Kitamoto, S Itoh, M TI ASCA sky survey observations and the cosmic X-ray background in 2-10 keV SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Tokyo Metropolitan Univ, Tokyo 19203, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Inoue, H (reprint author), Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. NR 12 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 197 EP 200 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500046 ER PT S AU Brown, A Osten, RA Drake, SA Jones, KL Stern, RA AF Brown, A Osten, RA Drake, SA Jones, KL Stern, RA BE Koyama, K Kitamoto, S Itoh, M TI Coronal variability and flaring of the RS CVn binaries sigma(2) CrB and HR1099 SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Univ Colorado, CASA, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, HEASARC, Greenbelt, MD 20771 USA. Univ Queensland, Dept Phys, Brisbane, Qld 4072, Australia. Lockheed Martin SAL, Palo Alto, CA 94304 USA. RP Brown, A (reprint author), Univ Colorado, CASA, Boulder, CO 80309 USA. NR 0 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 215 EP 216 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500052 ER PT S AU Singh, KP Drake, SA White, NE AF Singh, KP Drake, SA White, NE BE Koyama, K Kitamoto, S Itoh, M TI X-ray coronae from single late-type dwarf stars SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union ID EMISSION C1 Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Singh, KP (reprint author), Tata Inst Fundamental Res, Homi Bhabha Rd, Bombay 400005, Maharashtra, India. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 12 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 222 EP 223 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500056 ER PT S AU Tanaka, S Kitamoto, S Suzuki, T Torii, K Corcoran, MF Waldron, S AF Tanaka, S Kitamoto, S Suzuki, T Torii, K Corcoran, MF Waldron, S BE Koyama, K Kitamoto, S Itoh, M TI Chemical abundances of early type stars SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Osaka Univ, Dept Earth & Space Sci, Toyonaka, Osaka 560, Japan. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Appl Res Corp, Landover, MD 20785 USA. RP Tanaka, S (reprint author), Osaka Univ, Dept Earth & Space Sci, 1-1 Machikaneyama Cho, Toyonaka, Osaka 560, Japan. NR 0 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 224 EP 225 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500057 ER PT S AU Jenkins, EB Sofia, UJ Sonneborn, G AF Jenkins, EB Sofia, UJ Sonneborn, G BE Koyama, K Kitamoto, S Itoh, M TI Observations of interstellar O VI absorption at 3 km/s resolution SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Jenkins, EB (reprint author), Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. RI Jenkins, Edward/P-5684-2014 OI Jenkins, Edward/0000-0003-1892-4423 NR 3 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 271 EP 272 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500080 ER PT S AU Toneri, T Hayashida, K Loewenstein, M AF Toneri, T Hayashida, K Loewenstein, M BE Koyama, K Kitamoto, S Itoh, M TI X-ray observations of M32 with ASCA SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Osaka Univ, Dept Earth & Space Sci, Toyonaka, Osaka 560, Japan. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Toneri, T (reprint author), Osaka Univ, Dept Earth & Space Sci, 1-1 Machikaneyama Cho, Toyonaka, Osaka 560, Japan. NR 4 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 291 EP 292 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500090 ER PT S AU Matsumoto, R Valinia, A Tajima, T Mineshige, S Shibata, K AF Matsumoto, R Valinia, A Tajima, T Mineshige, S Shibata, K BE Koyama, K Kitamoto, S Itoh, M TI Magnetic field amplification and intergalactic plasma heating through magnetic twist injection from rotating galaxies SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Chiba Univ, Fac Sci, Dept Phys, Inage Ku, Chiba 263, Japan. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. Kyoto Univ, Dept Astron, Sakyo Ku, Kyoto 60601, Japan. Natl Astron Observ, Mitaka, Tokyo 181, Japan. RP Matsumoto, R (reprint author), Chiba Univ, Fac Sci, Dept Phys, Inage Ku, 1-33 Yayoi Cho, Chiba 263, Japan. 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 315 EP 316 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500103 ER PT S AU Yoshita, K Kitamoto, S Miyata, E Tsunemi, H Gendreau, KC AF Yoshita, K Kitamoto, S Miyata, E Tsunemi, H Gendreau, KC BE Koyama, K Kitamoto, S Itoh, M TI Direct measurement of the CCD with a subpixel resolution by using a new technique SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Osaka Univ, Grad Sch Sci, Toyonaka, Osaka 560, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Yoshita, K (reprint author), Osaka Univ, Grad Sch Sci, 1-1 Machikaneyama Cho, Toyonaka, Osaka 560, Japan. NR 0 TC 1 Z9 1 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 339 EP 340 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500114 ER PT S AU Maeda, Y Koyama, K Murakami, H Sakano, M Ebisawa, K Takeshima, T Yamauchi, S AF Maeda, Y Koyama, K Murakami, H Sakano, M Ebisawa, K Takeshima, T Yamauchi, S BE Koyama, K Kitamoto, S Itoh, M TI ASCA observations of the SgrA region SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union ID A1742-289 C1 Kyoto Univ, Grad Sch Sci, Dept Phys, Sakyo Ku, Kyoto 60601, Japan. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Iwate Univ, Fac Human & Social Sci, Morioka, Iwate 020, Japan. RP Maeda, Y (reprint author), Kyoto Univ, Grad Sch Sci, Dept Phys, Sakyo Ku, Kyoto 60601, Japan. NR 4 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 352 EP 353 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500120 ER PT S AU Takeshima, T AF Takeshima, T BE Koyama, K Kitamoto, S Itoh, M TI Discovery of QPO from X Persei with RXTE SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union ID MAGNETIC NEUTRON STARS; ACCRETION C1 NASA, Univ Space Res Assoc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Takeshima, T (reprint author), NASA, Univ Space Res Assoc, Goddard Space Flight Ctr, Greenbelt, MD 20771 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 368 EP 369 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500128 ER PT S AU Cui, W Zhang, SN Swank, JH Hua, XM Ebisawa, K Dotani, T AF Cui, W Zhang, SN Swank, JH Hua, XM Ebisawa, K Dotani, T BE Koyama, K Kitamoto, S Itoh, M TI Cygnus X-1: X-ray emission mechanism and geometry SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 MIT, Cambridge, MA 02139 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. RP Cui, W (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 9 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 386 EP 387 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500136 ER PT S AU Kubota, A Makishima, K Dotani, T Inoue, H Mitsuda, K Nagase, F Negoro, H Ueda, Y Ebisawa, K Kitamoto, S Tanaka, Y AF Kubota, A Makishima, K Dotani, T Inoue, H Mitsuda, K Nagase, F Negoro, H Ueda, Y Ebisawa, K Kitamoto, S Tanaka, Y BE Koyama, K Kitamoto, S Itoh, M TI X-ray determination of the black-hole mass in Cygnus X-1 SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 113, Japan. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Osaka Univ, Dept Earth & Space Sci, Toyonaka, Osaka 560, Japan. SRON, NL-3584 CA Utrecht, Netherlands. RP Kubota, A (reprint author), Univ Tokyo, Dept Phys, Bunkyo Ku, 7-3-1 Hongo, Tokyo 113, Japan. RI Mitsuda, Kazuhisa/C-2649-2008 NR 10 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 388 EP 389 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500137 ER PT S AU Ebisawa, K Takeshima, T White, NE Kotani, T Dotani, T Ueda, Y Harmon, BA Robinson, CR Zhang, SN Paciesas, WS Tavani, M Foster, R AF Ebisawa, K Takeshima, T White, NE Kotani, T Dotani, T Ueda, Y Harmon, BA Robinson, CR Zhang, SN Paciesas, WS Tavani, M Foster, R BE Koyama, K Kitamoto, S Itoh, M TI ASCA observations of the superluminal jet source GRS1915+105 SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RIKEN, Inst Phys & Chem Res, Wako, Saitama 35101, Japan. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. NASA, George Marshall Space Flight Ctr, Huntsville, AL 35806 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. USN, Res Lab, Washington, DC 20375 USA. RP Ebisawa, K (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 0 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 392 EP 393 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500139 ER PT S AU Van der Hooft, F Van Paradijs, J Van der Klis, M Kouveliotou, C Crary, DJ Finger, MH Rubin, BC Harmon, BA Fishman, GJ Lewin, WHG AF Van der Hooft, F Van Paradijs, J Van der Klis, M Kouveliotou, C Crary, DJ Finger, MH Rubin, BC Harmon, BA Fishman, GJ Lewin, WHG BE Koyama, K Kitamoto, S Itoh, M TI Rapid hard X-ray variability in GRO J0422+32 SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Univ Amsterdam, NL-1012 WX Amsterdam, Netherlands. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. MIT, Cambridge, MA 02139 USA. RP Van der Hooft, F (reprint author), Univ Amsterdam, NL-1012 WX Amsterdam, Netherlands. NR 3 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 398 EP 399 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500142 ER PT S AU Terashima, Y Kunieda, H Serlemitsos, PJ Ptak, A AF Terashima, Y Kunieda, H Serlemitsos, PJ Ptak, A BE Koyama, K Kitamoto, S Itoh, M TI X-ray properties of liners and low luminosity Seyfert galaxies observed with ASCA SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union AB We present ASCA spectra of low luminosity AGNs with X-ray luminosities of 10(40-41) ergs s(-1). Their X-ray continua are very similar to Seyfert galaxies. Although iron K emissin centered at 6.4 keV or 6.7 keV is detected from a few objects, iron K emission is weak on average. Possible reasons for variety of iron line properties are discussed. C1 Nagoya Univ, Dept Phys, Chikusa Ku, Nagoya, Aichi 464, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Terashima, Y (reprint author), Nagoya Univ, Dept Phys, Chikusa Ku, Nagoya, Aichi 464, Japan. 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 444 EP 445 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500165 ER PT S AU Ogasaka, Y Kii, T Ueda, Y Takahashi, T Inoue, H Ishisaki, Y Ohta, K Yamada, T Makishima, K Miyaji, T Hasinger, G AF Ogasaka, Y Kii, T Ueda, Y Takahashi, T Inoue, H Ishisaki, Y Ohta, K Yamada, T Makishima, K Miyaji, T Hasinger, G BE Koyama, K Kitamoto, S Itoh, M TI ASCA deep sky survey - The Log N Log S relation of faint extragalactic objects and their contribution to the Cosmic X-Ray Background SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo, Japan. Kyoto Univ, Dept Astron, Kyoto, Japan. Tohoku Univ, Astron Inst, Sendai, Miyagi 980, Japan. Univ Tokyo, Dept Phys, Tokyo, Japan. Astrophys Inst Potsdam, Potsdam, Germany. RP Ogasaka, Y (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 469 EP 470 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500176 ER PT S AU Ohta, K Akiyama, M Nakanishi, K Yamada, T Hayashida, K Kii, T Ogasaka, Y AF Ohta, K Akiyama, M Nakanishi, K Yamada, T Hayashida, K Kii, T Ogasaka, Y BE Koyama, K Kitamoto, S Itoh, M TI Optical follow-up observations of ASCA Lynx deep survey SO HOT UNIVERSE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 188th Symposium of the International-Astronomical-Union - The Hot Universe CY AUG 26-30, 1997 CL KYOTO, JAPAN SP Int Astron Union C1 Kyoto Univ, Dept Astron, Kyoto 60601, Japan. Tohoku Univ, Astron Inst, Sendai, Miyagi 98077, Japan. Osaka Univ, Dept Earth & Space Sci, Toyonaka, Osaka 560, Japan. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ohta, K (reprint author), Kyoto Univ, Dept Astron, Kyoto 60601, Japan. NR 0 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 0-7923-5058-8 J9 IAU SYMP PY 1998 IS 188 BP 471 EP 472 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM04D UT WOS:000077472500177 ER PT S AU Barth, E Zetzsche, C AF Barth, E Zetzsche, C BE Rogowitz, BE Pappas, TN TI Endstopped operators based on iterated nonlinear center-surround inhibition SO HUMAN VISION AND ELECTRONIC IMAGING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Human Vision & Electronic Imaging CY JAN 26-29, 1998 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE DE endstopping; retina; ganglion cells; lateral inhibition; feedback; corner detection; curvature; nonlinear features; topological features AB In this paper we analyze the properties of a repeated isotropic center-sunound inhibition which includes simple nonlinearities like half-wave rectification and saturation. Our simulation results show that such operations, here implemented as iterated nonlinear differences and ratios of Gaussians (INDOG and INROG), lead to endstopping. The benefits of the approach are twofold. Firstly, the INDOG can be used to design simple endstopped operators, e.g., corner detectors. Secondly, the results can explain how endstopping might arise in a neural network with purely isotropic characteristics. The iteration can be implemented as cascades by feeding the output of one NDOG to a next stage of NDOG. Alternatively, the INDOG mechanism can be activated in a feedback loop. In the latter case, the resulting spatio-temporal response properties are not separable and the response becomes spatially endstopped if the input is transient. Finally, we show that ON- and OFF-type INDOG outputs can be integrated spatially to result in quasi-topological image features like open versus closed and the number of components. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Barth, E (reprint author), NASA, Ames Res Ctr, MS 262-2, Moffett Field, CA 94035 USA. NR 0 TC 7 Z9 8 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2739-X J9 P SOC PHOTO-OPT INS PY 1998 VL 3299 BP 67 EP 78 DI 10.1117/12.320156 PG 12 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic; Optics SC Computer Science; Engineering; Optics GA BL49M UT WOS:000075700800007 ER PT S AU Beard, BL Ahumada, AJ AF Beard, BL Ahumada, AJ BE Rogowitz, BE Pappas, TN TI A technique to extract relevant image features for visual tasks SO HUMAN VISION AND ELECTRONIC IMAGING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Human Vision & Electronic Imaging CY JAN 26-29, 1998 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE DE spatial vision; stimulus classification; templates; visual noise; discrimination; vernier acuity; pattern recognition; detection AB Here we demonstrate a method for constructing stimulus classification images. These images provide information regarding the stimulus aspects the observer uses to segregate images into discrete response categories. Data are first collected on a discrimination task containing low contrast noise. The noises are then averaged separately for the stimulus-response categories. These averages are then summed with appropriate signs to obtain an overall classification image. We determine stimulus classification images for a vernier acuity task to visualize the stimulus features used to make these precise position discriminations. The resulting images reject the idea that the discrimination is performed by the single best discriminating cortical unit. The classification images show one Gabor-like filter for each line, rejecting the nearly ideal assumption of image discrimination models predicting no contribution from the fixed vernier line. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Beard, BL (reprint author), NASA, Ames Res Ctr, Mail Stop 262-2, Moffett Field, CA 94035 USA. NR 0 TC 63 Z9 63 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2739-X J9 P SOC PHOTO-OPT INS PY 1998 VL 3299 BP 79 EP 85 DI 10.1117/12.320099 PG 7 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic; Optics SC Computer Science; Engineering; Optics GA BL49M UT WOS:000075700800008 ER PT S AU Ahumada, AJ Beard, BL Eriksson, R AF Ahumada, AJ Beard, BL Eriksson, R BE Rogowitz, BE Pappas, TN TI Spatio-temporal discrimination model predicts temporal masking functions SO HUMAN VISION AND ELECTRONIC IMAGING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Human Vision & Electronic Imaging CY JAN 26-29, 1998 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE DE video; image quality; masking; vision models; target detection AB We present a simplified dual-channel discrimination model with spatio-temporal filters to represent the visual system contrast sensitivity, and masking based on local spatio-temporal contrast energy. The contrast sensitivity filter parameters of the model were based on previous work. The masking and global sensitivity parameters are calibrated to masking data using brief grating target signals masked by a 700 msec grating with the same spatial parameters. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Ahumada, AJ (reprint author), NASA, Ames Res Ctr, Mail Stop 262-2, Moffett Field, CA 94035 USA. NR 0 TC 8 Z9 8 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2739-X J9 P SOC PHOTO-OPT INS PY 1998 VL 3299 BP 120 EP 127 PG 8 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic; Optics SC Computer Science; Engineering; Optics GA BL49M UT WOS:000075700800012 ER PT S AU Watson, AB AF Watson, AB BE Rogowitz, BE Pappas, TN TI Toward a perceptual video quality metric SO HUMAN VISION AND ELECTRONIC IMAGING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Human Vision & Electronic Imaging CY JAN 26-29, 1998 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE DE vision; digital video; perception; quality; fidelity AB The advent of widespread distribution of digital video creates a need for automated methods for evaluating the visual quality of digital video. This is particularly so since most digital video is compressed using lossy methods, which involve the controlled introduction of potentially visible artifacts. Compounding the problem is the bursty nature of digital video, which requires adaptive bit allocation based on visual quality metrics, and the economic need to reduce bit-rate to the lowest level that yields acceptable quality. In previous work, we have developed visual quality metrics for evaluating, controlling, and optimizing the quality of compressed still images(1, 2, 3, 4). These metrics incorporate simplified models of human visual sensitivity to spatial and chromatic visual signals. Here I describe a new video quality metric that is an extension of these still image metrics into the time domain. Like the still image metrics, it is based on the Discrete Cosine Transform. An effort has been made to minimize the amount of memory and computation required by the metric, in order that might be applied in the widest range of applications. To calibrate the basic sensitivity of this metric to spatial and temporal signals we have made measurements of visual thresholds for temporally varying samples of DCT quantization noise. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Watson, AB (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 52 Z9 52 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2739-X J9 P SOC PHOTO-OPT INS PY 1998 VL 3299 BP 139 EP 147 DI 10.1117/12.320105 PG 9 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic; Optics SC Computer Science; Engineering; Optics GA BL49M UT WOS:000075700800014 ER PT S AU Morelli, MV Juday, RD Monroe, SE Chien, CH Li, WQ AF Morelli, MV Juday, RD Monroe, SE Chien, CH Li, WQ BE Casasent, DP Tescher, AG TI A hybrid image processing instantiation: I Optical subsystem SO HYBRID IMAGE AND SIGNAL PROCESSING VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Hybrid Image and Signal Processing VI CY APR 16, 1998 CL ORLANDO, FL SP SPIE DE optical correlation; filter theory; spatial light modulator AB We describe the optical correlator subsystem of a hybrid (digital/optical) vision system. The optical correlator has a Kopin SLIM at the input plane and a fast analog nematic Boulder Nonlinear Systems SLM at the filter plane. Filters are computed to provide identification and pose estimation for various objects. Spatial non-uniformities in the filter SLM are particularly bothersome from an operational standpoint. Methods of measuring and accommodating for the nonuniformities are described. Correlation filters produce an initially coarse identification, and later filters are intended to refine the coarse estimate of the pose of the observed object. Certain image preprocessing operations and their results are discussed; these include the cross-correlation that results when a Laplacian of Gaussian (LoG) image is used as input to the system whose filter has been computed for a Sobel edge-extracted version of the reference image. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Morelli, MV (reprint author), NASA, Lyndon B Johnson Space Ctr, MC ER5, Houston, TX 77058 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2838-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3389 BP 150 EP 157 DI 10.1117/12.316537 PG 8 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Optics SC Computer Science; Engineering; Optics GA BL57L UT WOS:000075914900017 ER PT S AU Carlson, B Gupta, V AF Carlson, B Gupta, V BE Henzinger, TA Sastry, S TI Hybrid cc with interval constraints SO HYBRID SYSTEMS: COMPUTATION AND CONTROL SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 1st International Workshop on Hybrid Systems - Computation and Control (HSCC 98) CY APR 13-15, 1998 CL BERKELEY, CALIFORNIA SP USA, Army Res Off ID SYSTEMS AB Hybrid cc is a constraint programming language suitable for modeling, controlling and simulating hybrid systems, i.e. systems with continuous and discrete state changes. The language extends the concurrent constraint programming framework with default reasoning and combinators for programming continuous behavior. The most important constraint systems used in Hybrid cc are nonlinear equations and ordinary differential equations over intervals. We describe the implementation of the Hybrid cc interpreter and constraint solvers, and evaluate the performance using some example programs. C1 Netscape Commun, Mt View, CA 94043 USA. NASA, Ames Res Ctr, Caelum Res Corp, Moffett Field, CA 94035 USA. RP Carlson, B (reprint author), Netscape Commun, 650 E Middlefield Rd,Bldg 1, Mt View, CA 94043 USA. NR 21 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64358-3 J9 LECT NOTES COMPUT SC PY 1998 VL 1386 BP 80 EP 95 PG 16 WC Automation & Control Systems; Computer Science, Theory & Methods SC Automation & Control Systems; Computer Science GA BM09B UT WOS:000077605500006 ER PT J AU Morris, RV Klingelhofer, G Korotev, RL Shelfer, TD AF Morris, RV Klingelhofer, G Korotev, RL Shelfer, TD TI Mossbauer mineralogy on the Moon: The lunar regolith SO HYPERFINE INTERACTIONS LA English DT Article; Proceedings Paper CT Mossbauer Symposium, at the 11th International Clay Conference (ICC-97) CY JUN 15-21, 1997 CL OTTAWA, CANADA ID SOILS; ROCK; HIGHLANDS; SURFACE; SITE AB A first-order requirement for spacecraft missions that land on solid planetary objects is instrumentation for mineralogical analyses. For purposes of providing diagnostic information about naturally-occurring materials, the element iron is particularly important because it is abundant and multivalent. Knowledge of the oxidation state of iron and its distribution among iron-bearing mineralogies tightly constrains the types of materials present and provides information about formation and modification (weathering) processes. Because Mossbauer spectroscopy is sensitive to both the valence of iron and its local chemical environment, the technique is unique in providing information about both the relative abundance of iron-bearing phases and oxidation state of the iron. The Mossbauer mineralogy of lunar regolith samples (primarily soils from the Apollo 16 and 17 missions to the Moon) were measured in the laboratory to demonstrate the strength of the technique for in-situ mineralogical exploration of the Moon. The regolith samples were modeled as mixtures of five iron-bearing phases: olivine, pyroxene, glass, ilmenite, and metal. Based on differences in relative proportions of iron associated with these phases, volcanic-ash regolith can be distinguished from impact-derived regolith, impact-derived soils of different geologic affinity (e.g., highlands and maria) can be distinguished on the basis of their constituent minerals, and soil maturity can be estimated. The total resonant absorption area of the Mossbauer spectrum can be used to estimate total FeO concentrations. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Darmstadt Univ Technol, D-64289 Darmstadt, Germany. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Etcetera Serv Inc, Houston, TX 77058 USA. RP Morris, RV (reprint author), NASA, Lyndon B Johnson Space Ctr, Code SN3, Houston, TX 77058 USA. NR 61 TC 14 Z9 14 U1 0 U2 6 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 0304-3843 J9 HYPERFINE INTERACT JI Hyperfine Interact. PY 1998 VL 117 IS 1-4 BP 405 EP 432 DI 10.1023/A:1012699511670 PG 28 WC Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Physics, Nuclear SC Physics GA 161VP UT WOS:000078310600018 ER PT J AU Newburn, RL AF Newburn, RL TI In memoriam - Jurgen H. Rahe (1939-1997) SO ICARUS LA English DT Biographical-Item C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Newburn, RL (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1998 VL 131 IS 1 BP 1 EP 3 DI 10.1006/icar.1997.5877 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ865 UT WOS:000072302000001 ER PT J AU Mitchell, DL Hudson, RS Ostro, SJ Rosema, KD AF Mitchell, DL Hudson, RS Ostro, SJ Rosema, KD TI Shape of asteroid 433 Eros from inversion of Goldstone radar Doppler spectra SO ICARUS LA English DT Article DE asteroid; radar; 433 Eros; shape; NEAR ID 433-EROS; IMAGES AB We use new analysis techniques to constrain the shape of 433 Eros with Goldstone radar data obtained during the asteroid's close approach in 1975, A previous analysis of these data (Ostro, Rosema, and Jurgens, 1990, Icarus 84, 334-351) used estimates of the echo's spectral edge frequencies as a function of asteroid rotation phase to constrain the convex envelope of Eros' pole-on silhouette, Our approach makes use of the echo's full Doppler-frequency distribution (effectively similar to 15 times more echo data points) and is thus capable of constraining shape characteristics, such as concavities, within this convex envelope. The radar echoes are weak and north-south ambiguous, which limits the accuracy of our models, We present two different approaches, perturbations to an ellipsoid and successive approximations, that help to quantify the model uncertainties and identify features that are likely to be real, Both approaches yield models that are tapered along their lengths, with one or more prominent concavities on one side but not the other. We do not have sufficient information to determine the exact nature of the concavities, and in particular, whether they are craters, troughs, or bends in Eros' overall shape, The pole-on silhouette of the successive approximation model is shaped like a kidney bean, which resembles a nearly pole-on optical image derived from speckle interferometry (Drummond and Hege, 1989, in Asteroids II (R. P. Binzell, T. Gehrels, and M. S. Matthews, Eds.), PD 171-191, Univ. of Arizona Press, Tucson); however, eve cannot exclude shapes, such as the perturbation model, with more than one large concavity. Variations in the pyroxene/olivine ratio over Eros' surface have been inferred from visual and infrared observations (Murchie and Pieters, 1996, J. Geophys. Res, 101, 2201-2214). Correlating these variations with our shape information, we find that the side with concavities is relatively pr-rich compared with the more rounded opposing side. (C) 1998 Academic Press. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Washington State Univ, Dept Elect Engn & Comp Sci, Pullman, WA 99164 USA. RP Mitchell, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 26 TC 21 Z9 23 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1998 VL 131 IS 1 BP 4 EP 14 DI 10.1006/icar.1997.5815 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ865 UT WOS:000072302000002 ER PT J AU Williams, KK Zuber, MT AF Williams, KK Zuber, MT TI Measurement and analysis of lunar basin depths from Clementine altimetry SO ICARUS LA English DT Review ID IMPACT CRATERS; VISCOUS RELAXATION; ACOUSTIC FLUIDIZATION; SCHEMATIC MODEL; MARE VOLCANISM; EVOLUTION; MOON; STRATIGRAPHY; TOPOGRAPHY; MECHANICS AB Altimetric profiles from the Clementine LIDAR are used to calculate the depths of 29 large craters and basins on the Moon. Plotting the depths of the best preserved structures together with values for simple and complex craters measured in pre-Clementine studies reveals an inflection in the depth/diameter (d/D) curve in addition to the one revealed by pre-Clementine data. This inflection occurs in the diameter range that corresponds to the morphologic transition from complex crater to basin. The best empirical power law fit for basin depths is log(10)(d) = 0.41 x [log(10)(D)](0.57). This relationship is characterized by a lower slope than that for complex craters, demonstrating that this morphologic transition corresponds to a further decrease in the depth of an impact structure relative to its diameter with increasing size. Qualitative consideration of possible causes for the second inflection leads to the conclusion that it is most likely a consequence of a short-term modification mechanism that influences fundamental crater morphology, such as the increasing influence of gravity with diameter. Thicknesses of maria in the major basins are calculated by assuming that their unfilled depths would follow the d/D relation. Results are compared with previous estimates and yield thicknesses that are generally greater than those determined by studies of flooded craters and less than those obtained from analysis of gravity. (C) 1998 Academic Press. C1 Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. RP Williams, KK (reprint author), Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. EM kkw@asu.edu NR 101 TC 59 Z9 64 U1 2 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1998 VL 131 IS 1 BP 107 EP 122 DI 10.1006/icar.1997.5856 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ865 UT WOS:000072302000008 ER PT J AU Anderson, JD Lau, EL Scherer, K Rosenbaum, DC Teplitz, VL AF Anderson, JD Lau, EL Scherer, K Rosenbaum, DC Teplitz, VL TI Kuiper belt constraint from Pioneer 10 SO ICARUS LA English DT Article DE comets; interplanetary dust; planetesimals; spacecraft ID NEPTUNE; CLOUD AB We extract information from the failure of small objects to cause detectable damage to Pioneer 10, which has been inside the Kuiper Belt for a decade, Belt objects too small for telescope detection and too large for IR emission visibility are addressed, This is a size range with few other potential techniques, short of a new space mission, for direct detection, Results, based on an 8-inch radius propellant tank, are bounds of about 1/10th of an Earth mass on low-mass, low-density objects, Implications of Poynting-Robertson drag and ISM erosion, and potential improvements to the bounds, are discussed. (C) 1998 Academic Press. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Max Planck Inst Aeron, D-37189 Katlenburg Lindau, Germany. So Methodist Univ, Dept Phys, Dallas, TX 75275 USA. RP Anderson, JD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM teplitz@phyvms.physics.smu.edu NR 21 TC 10 Z9 10 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1998 VL 131 IS 1 BP 167 EP 170 DI 10.1006/icar.1997.5867 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ865 UT WOS:000072302000012 ER PT J AU Friedson, AJ AF Friedson, AJ TI Formation of refractory grains in Shoemaker-Levy 9 fireballs SO ICARUS LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; COUNTERFLOW DIFFUSION FLAME; COMET SHOEMAKER-LEVY-9; MOLECULAR EQUILIBRIA; JUPITER ATMOSPHERE; INDUCED NUCLEATION; PARTICLE FORMATION; AMORPHOUS-CARBON; SILICON-CARBIDE; IMPACT PLUMES AB The composition, size, and number of the most refractory grains to condense in Shoemaker-Levy 9 fireballs are discussed. Chemical heterogeneity in the fireball may have led to the formation of two principal types of refractory particles. Small particles consisting of a mixture of Al2O3 and silicates are expected to form in those portions of the fireball where C/O < 1. In carbon-rich portions of the gas where C/O > 1, carbon may have condensed heterogeneously on preexisting SiC grains. Homogeneous formation of soot through the production and agglomeration of polycyclic aromatic hydrocarbons (PAHs) does not occur. Calculations based on kinetic models indicate that the mean particle radii would be less than 0.1 mu m for both types of chemical composition and that both types of particle would have been produced in sufficient numbers to have been visible as they rose into sunlight from behind Jupiter's limb. It is suggested that they may have provided sites for the heterogeneous nucleation of more volatile species after they came to rest in the jovian stratosphere and therefore may have comprised the cores of the dark aerosol debris particles seen suspended above the impact sites. (C) 1998 Academic Press. C1 CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. RP Friedson, AJ (reprint author), CALTECH, Jet Prop Lab, Div Earth & Space Sci, MS 169-237, Pasadena, CA 91109 USA. NR 56 TC 8 Z9 8 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1998 VL 131 IS 1 BP 179 EP 197 DI 10.1006/icar.1997.5853 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ865 UT WOS:000072302000014 ER PT J AU Hallenbeck, SL Nuth, JA Daukantas, PL AF Hallenbeck, SL Nuth, JA Daukantas, PL TI Mid-infrared spectral evolution of amorphous magnesium silicate smokes annealed in vacuum: Comparison to cometary spectra SO ICARUS LA English DT Article DE infrared observations; general; comets; dust; interplanetary dust ID INTERPLANETARY DUST; EMISSION FEATURE; GLASSES; IDENTIFICATION; SPECTROSCOPY; EXTINCTION; OLIVINE; GRAINS; HALLEY; MELTS AB Amorphous magnesium silicate smokes were prepared by vapor phase condensation and annealed in vacuum. The samples were monitored by IR spectroscopy as a function of annealing time and temperature, focusing on the development of the 10 mu m silicate feature, The IR spectrum of the initial condensate displayed a broad band at 9.3 mu m. After annealing for 10.5 h at 1027 K, a dual maximum was established at 9.8 and 11.0 mu m, Following this period of evolution no significant changes were observed in the 10 mu m silicate feature during the next 37.5 fi of annealing, Thereafter, individual features sharpened as the sample became more ordered. There appears to be a natural pause in the spectral evolution of these samples, midway between the initially chaotic condensate and the more ordered glass, The duration of the spectral stall was investigated from 1000 to 1048 It and was highly dependent on the annealing temperature, The evolving 10 mu m feature was deconvolved by fitting the observed bands with symmetric Gaussian peaks positioned at 8.35, 9.00, 9.77, 10.87, 11.30, 11.87, and 12.22 pm. Preliminary results of annealing studies on iron silicate and mixed-metal, magnesium-iron silicate smokes revealed distinctly different rates of sample evolution. The "olivine-rich" comets Halley, Bradfield, Levy, Mueller, and Hale-Bopp all display emission features with dual maxima at 9.8 and 11.2 mu m which closely resemble the magnesium silicate smoke stall spectra. (C) 1998 Academic Press. C1 NASA, Goddard Space Flight Ctr, Astrochem Branch, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20740 USA. RP Hallenbeck, SL (reprint author), NASA, Goddard Space Flight Ctr, Astrochem Branch, Code 691, Greenbelt, MD 20771 USA. EM Joseph.Nuth.@gsfc.nasa.gov RI Nuth, Joseph/E-7085-2012 NR 35 TC 123 Z9 124 U1 0 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1998 VL 131 IS 1 BP 198 EP 209 DI 10.1006/icar.1997.5854 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ865 UT WOS:000072302000015 ER PT J AU Nelson, RM Hapke, BW Smythe, WD Horn, LJ AF Nelson, RM Hapke, BW Smythe, WD Horn, LJ TI Phase curves of selected particulate materials: The contribution of coherent backscattering to the opposition surge SO ICARUS LA English DT Article ID OUTER PLANET SATELLITES; URANIAN SATELLITES; WEAK LOCALIZATION; POLARIZED-LIGHT; PARTICLES; MEDIA AB We present angular scattering measurements of a suite of particulate materials of varying particle sizes and albedos over phase angles of 1 < Theta < 70 degrees. Our results provide strong support for the hypothesis that coherent backscattering can be an important contributor to the enhanced reflectance seen in planetary regolith materials when observed at small phase angles, commonly known in the planetary science community as the opposition effect. Eight samples were each presented with both senses of linearly and circularly polarized light and the reflectance and the circular polarization ratio as a function of phase angle was measured. The reflectances of the samples varied from 3 to 99%, The circular polarization ratio was observed to increase in all the samples as the phase angle of the observation decreased near 0 degrees phase angle. The traditional explanation of the opposition surge, the shadow hiding model, predicts that the circular polarization ratio should decrease as the phase angle of the observation decreases, The more reflective materials exhibit stronger opposition surge amplitudes than the less reflective ones. We find a nonlinear relationship between the slope of the opposition curve measured at 2 degrees and the single scattering albedo of the sample which is the opposite of what is predicted by the shadow hiding model for the opposition effect. Our results are consistent with predictions of theoretical models of coherent backscattering from spherical particles and strongly suggest that coherent backscattering is the major contributor to the opposition effect. They provide an explanation of the opposition surges reported in highly reflective particulate media, and also the high albedo icy satellites of outer Solar System, both of which cannot be explained by the shadow hiding model. (C) 1998 Academic Press. C1 CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. Univ Pittsburgh, Dept Geol & Planetary Sci, Pittsburgh, PA 15260 USA. RP Nelson, RM (reprint author), CALTECH, Jet Prop Lab, Div Earth & Space Sci, 4500 Oak Grove Dr, Pasadena, CA 91109 USA. EM robert.m.nelson@jpl.nasa.gov NR 34 TC 40 Z9 40 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1998 VL 131 IS 1 BP 223 EP 230 DI 10.1006/icar.1997.5850 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ865 UT WOS:000072302000017 ER PT J AU Abrahams, MD Rivera, G Ames, CK AF Abrahams, MD Rivera, G Ames, CK TI Trials and tribulations of implementing intranet technology: The Cassini Information Access System SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB The Cassini Information Access System (LAS) was built to provide Cassini Integration and Test engineers with ready access to current technical and logistical project information. World Wide Web (www) technology was used to provide a consistent user interface to pre-existing interactive systems as well as new repositories and interactive services developed specifically for Cassini. A Web "gateway" was developed for each pre-existing data service. Each service had its unique requirements including read-only and read-and-write access to SQL databases. Other requirements called for the development of many background processes to handle the access of data produced by proprietary databases and non-database data repositories. Through the use of the www, anonymous ftp, Novell services, and unique data conversion programs, we were able to put the system into limited operation by August 1995 and full operation by March 1996. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Abrahams, MD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD JAN PY 1998 VL 13 IS 1 BP 20 EP 24 DI 10.1109/62.653792 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA YR945 UT WOS:000071547600008 ER PT B AU Borgioli, A Cwik, T AF Borgioli, A Cwik, T GP IEEE TI Numerical differentiation for adaptively refined finite element meshes SO IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM - ANTENNAS: GATEWAYS TO THE GLOBAL NETWORK, VOLS 1-4 SE IEEE AP-S INTERNATIONAL SYMPOSIUM DIGEST LA English DT Proceedings Paper CT IEEE Antennas-and-Propagation-Society International Symposium on Antennas - Gateways to the Global Network CY JUN 21-26, 1998 CL ATLANTA, GA SP IEEE, Antennas & Propagat Soc, Int Union Radio Sci, USNC, BMW Mfg Corp, Georgia Inst Technol, Georgia Tech Res Inst, Clemson Univ, Electromagnet Sci, Sci Atlanta, Spartech Associates, Millimeter Wave Technol, Wang Electro Opto Corp AB Postprocessing of point-wise data is a fundamental process in many fields of research. Numerical differentiation is a key operation in computational electromagnetics. In the case of data obtained from a finite element method with automatic mesh refinement much work needs still to be done. This paper addresses some issues in differentiating data obtained from a finite element electromagnetic code with adaptive mesh refinement, and it proposes a methodology for deriving the electric field given the magnetic field on a mesh of linear triangular elements. The procedure itself is nevertheless more general and might be extended for numerically differentiating any point-wise solution based on triangular meshes. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Borgioli, A (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4478-2 J9 IEEE AP-S PY 1998 BP 256 EP 259 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BL38W UT WOS:000075349900065 ER PT B AU Pogorzelski, RJ Maccarini, PF York, RA AF Pogorzelski, RJ Maccarini, PF York, RA GP IEEE TI The dynamics of coupled oscillator phase control SO IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM - ANTENNAS: GATEWAYS TO THE GLOBAL NETWORK, VOLS 1-4 SE IEEE AP-S INTERNATIONAL SYMPOSIUM DIGEST LA English DT Proceedings Paper CT IEEE Antennas-and-Propagation-Society International Symposium on Antennas - Gateways to the Global Network CY JUN 21-26, 1998 CL ATLANTA, GA SP IEEE, Antennas & Propagat Soc, Int Union Radio Sci, USNC, BMW Mfg Corp, Georgia Inst Technol, Georgia Tech Res Inst, Clemson Univ, Electromagnet Sci, Sci Atlanta, Spartech Associates, Millimeter Wave Technol, Wang Electro Opto Corp C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Pogorzelski, RJ (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4478-2 J9 IEEE AP-S PY 1998 BP 462 EP 465 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BL38W UT WOS:000075349900113 ER PT B AU Simons, RN Lee, RQ AF Simons, RN Lee, RQ GP IEEE TI Linearly tapered slot antenna radiation characteristics at millimeter-wave frequencies SO IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM - ANTENNAS: GATEWAYS TO THE GLOBAL NETWORK, VOLS 1-4 SE IEEE AP-S INTERNATIONAL SYMPOSIUM DIGEST LA English DT Proceedings Paper CT IEEE Antennas-and-Propagation-Society International Symposium on Antennas - Gateways to the Global Network CY JUN 21-26, 1998 CL ATLANTA, GA SP IEEE, Antennas & Propagat Soc, Int Union Radio Sci, USNC, BMW Mfg Corp, Georgia Inst Technol, Georgia Tech Res Inst, Clemson Univ, Electromagnet Sci, Sci Atlanta, Spartech Associates, Millimeter Wave Technol, Wang Electro Opto Corp C1 NASA, Nyma Grp, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Simons, RN (reprint author), NASA, Nyma Grp, Lewis Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4478-2 J9 IEEE AP-S PY 1998 BP 1168 EP 1171 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BL38W UT WOS:000075349900288 ER PT B AU Lee, RQ Simons, RN AF Lee, RQ Simons, RN GP IEEE TI Orthogonal feeding techniques for tapered slot antennas SO IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM - ANTENNAS: GATEWAYS TO THE GLOBAL NETWORK, VOLS 1-4 SE IEEE AP-S INTERNATIONAL SYMPOSIUM DIGEST LA English DT Proceedings Paper CT IEEE Antennas-and-Propagation-Society International Symposium on Antennas - Gateways to the Global Network CY JUN 21-26, 1998 CL ATLANTA, GA SP IEEE, Antennas & Propagat Soc, Int Union Radio Sci, USNC, BMW Mfg Corp, Georgia Inst Technol, Georgia Tech Res Inst, Clemson Univ, Electromagnet Sci, Sci Atlanta, Spartech Associates, Millimeter Wave Technol, Wang Electro Opto Corp C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Lee, RQ (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4478-2 J9 IEEE AP-S PY 1998 BP 1172 EP 1175 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BL38W UT WOS:000075349900289 ER PT B AU Thomas, RF Huang, J AF Thomas, RF Huang, J GP IEEE TI Ultra-wideband UHF microstrip array for GeoSAR application SO IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM - ANTENNAS: GATEWAYS TO THE GLOBAL NETWORK, VOLS 1-4 SE IEEE AP-S INTERNATIONAL SYMPOSIUM DIGEST LA English DT Proceedings Paper CT IEEE Antennas-and-Propagation-Society International Symposium on Antennas - Gateways to the Global Network CY JUN 21-26, 1998 CL ATLANTA, GA SP IEEE, Antennas & Propagat Soc, Int Union Radio Sci, USNC, BMW Mfg Corp, Georgia Inst Technol, Georgia Tech Res Inst, Clemson Univ, Electromagnet Sci, Sci Atlanta, Spartech Associates, Millimeter Wave Technol, Wang Electro Opto Corp C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Thomas, RF (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4478-2 J9 IEEE AP-S PY 1998 BP 2096 EP 2099 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BL38W UT WOS:000075349900509 ER PT B AU Huang, J Lou, M Feria, A Kim, Y AF Huang, J Lou, M Feria, A Kim, Y GP IEEE TI An inflatable L-band microstrip SAR array SO IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM - ANTENNAS: GATEWAYS TO THE GLOBAL NETWORK, VOLS 1-4 SE IEEE AP-S INTERNATIONAL SYMPOSIUM DIGEST LA English DT Proceedings Paper CT IEEE Antennas-and-Propagation-Society International Symposium on Antennas - Gateways to the Global Network CY JUN 21-26, 1998 CL ATLANTA, GA SP IEEE, Antennas & Propagat Soc, Int Union Radio Sci, USNC, BMW Mfg Corp, Georgia Inst Technol, Georgia Tech Res Inst, Clemson Univ, Electromagnet Sci, Sci Atlanta, Spartech Associates, Millimeter Wave Technol, Wang Electro Opto Corp C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Huang, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4478-2 J9 IEEE AP-S PY 1998 BP 2100 EP 2103 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BL38W UT WOS:000075349900510 ER PT S AU Nelson, ML Maly, K Shen, SNT Zubair, M AF Nelson, ML Maly, K Shen, SNT Zubair, M GP IEEE COMP SOC IEEE COMP SOC TI NCSTRL+: Adding multi-discipline and multi-genre support to the Dienst protocol using clusters and buckets SO IEEE INTERNATIONAL FORUM ON RESEARCH AND TECHNOLOGY ADVANCES IN DIGITAL LIBRARIES -ADL'98-, PROCEEDINGS SE PROCEEDINGS - IEEE INTERNATIONAL FORUM ON RESEARCH AND TECHNOLOGY ADVANCES IN DIGITAL LIBRARIES LA English DT Proceedings Paper CT IEEE International Forum on Research and Technology Advances in Digital Libraries (ADL 98) CY APR 22-24, 1998 CL SANTA BARBARA, CA SP IEEE Comp Soc, Tech Comm Digital Libs, NASA Goddard Space Flight Ctr, Natl Lib Med, Alexandria Digital Lib, Lib Congress, CESDIS, Hughes Aircraft, IBM AB We describe NCSTRL+, a unified, canonical digital library for scientific and technical information (STI). NCSTRL+ is based on the Networked Computer Science Technical Report Library (NCSTRL), a World Wide Web (WWW) accessible digital library (DL) that provides access to over 100 university departments and laboratories. NCSTRL+ implements two new technologies: cluster functionality and publishing "buckets". We have extended Dienst, the protocol underlying NCSTRL, to provide the ability to "cluster" independent collections into a logically centralized digital library based upon subject category classification, type of organization, and genres of material. The bucket construct provides a mechanism for publishing and managing logically linked entities with multiple data forms as a single object. The NCSTRL+ prototype DL contains the holdings of NCSTRL and the NASA Technical Report Server (NTRS). The prototype demonstrates the feasibility of publishing into a multi-cluster DL, searching across clusters, and storing aid presenting buckets of information. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Nelson, ML (reprint author), NASA, Langley Res Ctr, MS 158, Hampton, VA 23681 USA. OI Nelson, Michael/0000-0003-3749-8116 NR 0 TC 5 Z9 5 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1092-9959 BN 0-8186-8464-X J9 P IEEE INT FORUM RES PY 1998 BP 128 EP 136 DI 10.1109/ADL.1998.670387 PG 9 WC Computer Science, Information Systems SC Computer Science GA BK94U UT WOS:000073925000014 ER PT B AU Kortenkamp, D MacMahon, M Ryan, D Bonasso, RP Moreland, L AF Kortenkamp, D MacMahon, M Ryan, D Bonasso, RP Moreland, L GP IEEE TI Applying a layered control architecture to a free-flying space camera SO IEEE INTERNATIONAL JOINT SYMPOSIA ON INTELLIGENCE AND SYSTEMS - PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Joint Symposia on Intelligence and Systems CY MAY 21-23, 1998 CL ROCKVILLE, MD SP IEEE, Comp Soc Tech Comm Pattern Anal & Machine Intelligence AB The's paper describes a prototype robot for space applications. The robot is the first: generation of a freeflying robotic camera that will assist astronauts in constructing and maintaining the space station. The goal of the robot is to provide remote views to astronauts and ground controllers. The robot can, autonomously move to locations on an air bearing table, can track targets and can plan. paths. The robot contains a large collection of different technologies and this paper concentrates on a layered control architecture that integrates robot all functions. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Kortenkamp, D (reprint author), NASA, Lyndon B Johnson Space Ctr, ER2, Houston, TX 77058 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8548-4 PY 1998 BP 188 EP 194 DI 10.1109/IJSIS.1998.685442 PG 7 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical SC Automation & Control Systems; Computer Science; Engineering GA BL15R UT WOS:000074498700026 ER PT B AU Schreckenghost, D Bonasso, P Kortenkamp, D Ryan, D AF Schreckenghost, D Bonasso, P Kortenkamp, D Ryan, D GP IEEE TI Three tier architecture for controlling space life support systems SO IEEE INTERNATIONAL JOINT SYMPOSIA ON INTELLIGENCE AND SYSTEMS - PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Joint Symposia on Intelligence and Systems CY MAY 21-23, 1998 CL ROCKVILLE, MD SP IEEE, Comp Soc Tech Comm Pattern Anal & Machine Intelligence AB Managing life support for remote facilities requires maintaining environmental conditions beneficial to humans and plants, and managing resources like water product gases, and food. Appropriate allocation and coordination of these tasks among humans, robots, and life support systems is important for efficient operations. The need for operational flexibility and reactivity combined with the need to reduce crew workload and the high cost of failure to manage resources effectively suggests automating low level control tasks and assisting humans bl strategic planning and resource management. The three tier (3T) layered architecture is well-suited for such automated control. The planner automates task coordination across subsystems contending for resources. The separation of deliberative tasks from reactive tasks enables appropriate human intervention in autonomous operations, Ar each tier, mechanisms are provided for flexible response to novel events. We demonstrated the effectiveness of 3T to control life support systems for NASA's Lunar/Mars Life Support Test Project. C1 NASA, Lyndon B Johnson Space Ctr, Texas Robot & Automat Ctr, ER2, Houston, TX 77058 USA. RP Schreckenghost, D (reprint author), NASA, Lyndon B Johnson Space Ctr, Texas Robot & Automat Ctr, ER2, Houston, TX 77058 USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8548-4 PY 1998 BP 195 EP 201 DI 10.1109/IJSIS.1998.685444 PG 7 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical SC Automation & Control Systems; Computer Science; Engineering GA BL15R UT WOS:000074498700027 ER PT J AU Egan, A Ning, CZ Moloney, JV Indik, RA Wright, MW Bossert, DJ McInerney, JG AF Egan, A Ning, CZ Moloney, JV Indik, RA Wright, MW Bossert, DJ McInerney, JG TI Dynamic instabilities in master oscillator power amplifier semiconductor lasers SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID DIFFRACTION-LIMITED OPERATION; W CW; MOPA AB We investigate theoretically the master oscillator power amplifier using a semiconductor laser model that is fully time and space (laterally and longitudinally) resolved, We numerically examine the stability of the device and identify the nature of the different instabilities. These can arise from undamped relaxation oscillations, beating between the longitudinal modes of any of the cavities that comprise the device, or lateral filamentation. C1 Univ Arizona, Arizona Ctr Math Sci, Tucson, AZ 85721 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. USAF, Phillips Lab, Semicond Laser Branch, Kirtland AFB, NM 87117 USA. Univ Coll, Dept Phys, Cork, Ireland. RP Egan, A (reprint author), Univ Arizona, Arizona Ctr Math Sci, Tucson, AZ 85721 USA. RI Ning, C. Z./D-4699-2009 OI Ning, C. Z./0000-0003-4583-8889 NR 17 TC 46 Z9 46 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD JAN PY 1998 VL 34 IS 1 BP 166 EP 170 DI 10.1109/3.655020 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA YP054 UT WOS:000071236600021 ER PT S AU Lo, VY AF Lo, VY GP IEEE IEEE TI An enhanced spectral analysis tool (SAT) for radio frequency interference analysis and spectrum management SO IEEE MILITARY COMMUNICATIONS CONFERENCE - PROCEEDINGS, VOLS 1-3 SE IEEE Military Communications Conference LA English DT Proceedings Paper CT IEEE Military Communications Conference (MILCOM 98) CY OCT 18-21, 1998 CL BOSTON, MA SP IEEE AB A microcomputer based software for analysis of radio frequency interference is presented in this paper. The latest version 5 of the spectral analysis tool (SAT) contains numerous features essential for effective spectrum management. Included in SAT windows menu are editors of signal/interference, filters, spikes, power spectrum plots, calculators for spectral power, telecommunication link budget tables and interference analysis tables. Configuration menu for the analysis table contains options on antenna, amplifier and receiver for ground terminal characterization. The complete software package of SAT with windows installation program fits within a single 3.5 inch diskette for easy, distribution. An example on the application of SAT is also included in this paper. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lo, VY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 161-241, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2155-7578 BN 0-7803-4506-1 J9 IEEE MILIT COMMUN C PY 1998 BP 643 EP 647 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BL88F UT WOS:000077034600119 ER PT S AU Agan, MJ Olson, BH Pasqualino, CR Stevens, GL AF Agan, MJ Olson, BH Pasqualino, CR Stevens, GL GP IEEE IEEE TI A highly miniaturized, battery operated, commandable, digital wireless camera SO IEEE MILITARY COMMUNICATIONS CONFERENCE - PROCEEDINGS, VOLS 1-3 SE IEEE Military Communications Conference LA English DT Proceedings Paper CT IEEE Military Communications Conference (MILCOM 98) CY OCT 18-21, 1998 CL BOSTON, MA SP IEEE AB This paper discusses the design, development, testing, and demonstration of a highly miniaturized, battery operated digital wireless camera. The miniature wireless camera receives commands transmitted from a remote base station requesting it to take one or more frames of data, and broadcasts the digital image data to the base station receiver for display. The camera uses a complementary metal-oxide-semiconductor (CMOS) active pixel image sensor (APS) that achieves noise performance comparable to a charge-coupled device (CCD) with orders of magnitude better power consumption performance. The image sensor is integrated with a wireless communications transceiver, antennas and batteries into a stand alone miniature package. The results of a three year development effort are described. The miniature wireless camera will be delivered to the Defense Advanced Research Projects Agency (DARPA) in duly 1998. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Agan, MJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2155-7578 BN 0-7803-4506-1 J9 IEEE MILIT COMMUN C PY 1998 BP 913 EP 918 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BL88F UT WOS:000077034600172 ER PT J AU Yao, XS AF Yao, XS TI Brillouin selective sideband amplification of microwave photonic signals SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE Brillouin scattering; down-conversion; microwave photonics; microwave; optical amplification; sidebands; signal mixing; up-conversion ID TRANSMISSION AB We introduce a powerful Brillouin selective sideband amplification technique and demonstrate an important application for achieving gain in photonic signal up-and down-conversions in microwave photonic systems, We show that systems employing such a scheme is also automatically immune to the fiber dispersion effect. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yao, XS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 52 Z9 53 U1 2 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD JAN PY 1998 VL 10 IS 1 BP 138 EP 140 DI 10.1109/68.651138 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA YN129 UT WOS:000071136000046 ER PT J AU Markley, FL Bar-Itzhack, IY AF Markley, FL Bar-Itzhack, IY TI Unconstrained optimal transformation matrix SO IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS LA English DT Letter ID ATTITUDE DETERMINATION; VECTOR OBSERVATIONS AB We generalize Brock's minimization of the loss function proposed by Wahba to give a least-squares estimate of satellite attitude. We follow Brock in relaxing Wahba's requirement that the minimizing attitude matrix be orthogonal, and discuss the statistical properties of our new solution and its relation to existing attitude estimation algorithms. C1 NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Branch, Greenbelt, MD 20771 USA. Technion Israel Inst Technol, Fac Aerosp Engn, IL-32000 Haifa, Israel. RP Markley, FL (reprint author), NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Branch, Code 712, Greenbelt, MD 20771 USA. NR 12 TC 6 Z9 6 U1 3 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9251 J9 IEEE T AERO ELEC SYS JI IEEE Trans. Aerosp. Electron. Syst. PD JAN PY 1998 VL 34 IS 1 BP 338 EP 340 DI 10.1109/7.640293 PG 3 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA YQ113 UT WOS:000071349800033 ER PT J AU Liu, Y Frasier, SJ McIntosh, RE AF Liu, Y Frasier, SJ McIntosh, RE TI Measurement and classification of low-grazing-angle radar sea spikes SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE sea surface electromagnetic scattering ID AFFECTING MICROWAVE BACKSCATTER; SHORT GRAVITY-WAVES; BREAKING WAVES; BRAGG SCATTERING; OCEAN SURFACE; MODERATE; MODEL; WATER; WIND AB High-resolution dual-polarization X-band images of the ocean surface were obtained at a grazing angle of about 3 degrees, Area extensive imaging allowed us to study backscatter properties of sea spikes and to compare radar measurements with visual surface features evident from video recordings, The vertically polarized radar images consist of distributed scatter whose amplitude and Doppler velocity are modulated by larger scale gravity waves consistent with Bragg scattering and composite surface theory (CST). The horizontally polarized radar images are dominated by spatially discrete scattering centers (or sea spikes) moving at velocities comparable to the phase velocities of gravity waves beyond the spectral peak, These sea spikes also exist in the corresponding V-pol radar images, but are less prominent due to the dominant Bragg backscatter. Sea spikes are characterized by polarization ratios H/V that often exceed unity, typically by about 5 dB, Comparison of the larger spikes with simultaneous co-registered video recording of the surface indicates that approximately 30% of observed sea spikes are associated with actively breaking waves (whitecaps) while the remainder are identified with "steep" wave features, By classifying the larger sea spikes according to their corresponding surface features, we find Doppler velocities for sea spikes due to whitecaps noticeably faster (about 50%) than other sea spikes, though the distributions for both overlap significantly, We also find little measurable difference in the polarization ratios of the two classes of sea spikes as observed on the open ocean. C1 Univ Massachusetts, Microwave Remote Sensing lab, Amherst, MA 01003 USA. RP Liu, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Frasier, Stephen/H-1536-2015 OI Frasier, Stephen/0000-0003-4287-2889 NR 32 TC 41 Z9 43 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD JAN PY 1998 VL 46 IS 1 BP 27 EP 40 DI 10.1109/8.655448 PG 14 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA YR399 UT WOS:000071491300004 ER PT J AU Heymann, M Lin, F AF Heymann, M Lin, F TI Discrete-event control of nondeterministic systems SO IEEE TRANSACTIONS ON AUTOMATIC CONTROL LA English DT Article DE discrete-event systems; nondeterminism; supervisory control; trajectory model ID DECENTRALIZED SUPERVISORY CONTROL; PRIORITIZED SYNCHRONIZATION AB Nondeterminism in discrete-event systems occurs in many practical situations and often as a result of partial observability of events, For the adequate description of nondeterministic systems and nondeterministic phenomena, the trajectory-model formalism was introduced in [6] and [7]. This formalism has been used in [26] (also [14] and [15]) for obtaining various results on supervisory control of nondeterministic systems subject to language specifications. In the present paper we develop a theory of supervisory control for nondeterministic discrete-event systems subject to both language and trajectory-model specifications, We further show how well-known algorithms for supervisory control (of deterministic systems) under partial observation can be adapted for synthesis of supervisors for nondeterministic systems subject to both language and trajectory-model specifications. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Wayne State Univ, Dept Elect & Comp Engn, Detroit, MI 48202 USA. RP Heymann, M (reprint author), Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel. NR 27 TC 49 Z9 52 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9286 J9 IEEE T AUTOMAT CONTR JI IEEE Trans. Autom. Control PD JAN PY 1998 VL 43 IS 1 BP 3 EP 17 DI 10.1109/9.654883 PG 15 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA YR913 UT WOS:000071544400002 ER PT J AU Joughin, IR Kwok, R Fahnestock, MA AF Joughin, IR Kwok, R Fahnestock, MA TI Interferometric estimation of three-dimensional ice-flow using ascending and descending passes SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE interferometry; remote sensing; synthetic aperture radar (SAR) ID SATELLITE RADAR INTERFEROMETRY; SHEET MOTION; TOPOGRAPHY; DYNAMICS AB Satellite radar interferometry (SRI) provides an important new tool for determining ice-flow velocity, Interferometric measurements made from a single-track direction are sensitive only to a single component of the three-component velocity vector, Observations from along three different track directions would allow the full velocity vector to be determined, A north/south-looking synthetic aperture radar (SAR) could provide these observations over large portions of the globe, but not over large areas of the polar ice sheets, We develop and demonstrate a technique that allows the three-component velocity vector to be estimated from data acquired along two track directions (ascending and descending) under a surface-parallel how assumption, This technique requires that we have accurate estimates of the surface slope, which we also determined interferometrically, To demonstrate the technique, we estimate the three-component velocity field for the Ryder Glacier, Greenland, Our results are promising, although we do not have yet ground-truth data with which to determine the accuracy of our estimates. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Maryland, Dept Meteorol, Joint Ctr Earth Syst Sci, College Pk, MD 20742 USA. RP Joughin, IR (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RI Kwok, Ron/A-9762-2008; Joughin, Ian/A-2998-2008; Fahnestock, Mark/N-2678-2013 OI Kwok, Ron/0000-0003-4051-5896; Joughin, Ian/0000-0001-6229-679X; NR 29 TC 121 Z9 124 U1 0 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1998 VL 36 IS 1 BP 25 EP 37 DI 10.1109/36.655315 PG 13 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA YT522 UT WOS:000071615500003 ER PT J AU Le, CTC Ishimaru, A Kuga, Y Yea, JH AF Le, CTC Ishimaru, A Kuga, Y Yea, JH TI Angular memory and frequency interferometry for mean height profiling of a rough surface SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID SYNTHETIC APERTURE RADARS; WAVE AB The polarimetric angular memory effect is applied to obtain the average topographic height of a rough surface, This novel effect improves the height sensitivity while maintaining a good degree of correlation between the sensors, By using a reference hat surface, the interferometric phase is linearly related to the mean topographic height, The combination of angular memory and wideband frequency interferometry (AMFI) is realized and offers a means to design a robust interferometric system, Extension of the technique to the pulse scattering problem is studied through the two-frequency mutual coherence function, and its time-domain transform provides an equivalent way to obtain the mean topographic height by combining both spatial and temporal diversity, Millimeter-wave (MMW) experiments are conducted with rough surfaces of different statistics and scattering media of different types (gravel, sand, and rough surfaces) to prove the effectiveness of the technique. C1 Univ Washington, Dept Elect Engn, Seattle, WA 98195 USA. RP Le, CTC (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1998 VL 36 IS 1 BP 61 EP 71 DI 10.1109/36.655318 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA YT522 UT WOS:000071615500006 ER PT J AU Johnson, JT Shin, RT Kong, JA Tsang, L Pak, K AF Johnson, JT Shin, RT Kong, JA Tsang, L Pak, K TI A numerical study of the composite surface model for ocean backscattering SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID MONTE-CARLO SIMULATIONS; RANDOM ROUGH SURFACES; KIRCHHOFF APPROXIMATION; ELECTROMAGNETIC-WAVES; ACOUSTIC SCATTERING; POLARIZATION; ENHANCEMENT; VALIDITY; SPECTRUM AB A numerical study of 14-GHz backscattering from ocean-like surfaces, described by a Pierson-Moskowitz spectrum, is presented. Surfaces rough in one and two dimensions are investigated, with Monte Carlo simulations performed efficiently through the use of the canonical-grid expansion in an iterative method of moments, Backscattering cross sections are illustrated for perfectly conducting surfaces at angles from 0 to 60 degrees from normal incidence, and the efficiency of the numerical model enables the composite surface theory to be studied in the microwave frequency range for realistic one-dimensional (1-D) surface profiles at low mind speeds (3 m/s), Variations with surface spectrum low-frequency cutoff (ranging over spatial lengths from 21.9 to 4.29 cm) are investigated to obtain an assessment of composite surface model accuracy, The 1-D surface results show an increase in hh backscatter returns as surface low-frequency content is increased for incidence angles larger than 30 degrees, while upsilon upsilon returns remain relatively constant, all as predicted bg the composite surface model, Similar results are obtained for surfaces rough in two dimensions, although the increased computational complexity allows maximum surface sizes of only 1.37 m to be considered. In addition, cross-polarized cross sections are studied in the two-dimensional (2-D) surface case and again found to increase as surface low-frequency content is increased, For both 1-D and 2-D surfaces, backscattering cross sections within 20 degrees of normal incidence are found to be well matched by both Monte Carlo and analytical physical optics (PO) methods for all low-frequency cutoffs considered, and a comparison of analytical PO and geometrical optics (GO) results indicates an appropriate choice of the cutoff wavenumber in the composite wt-face model to insure an accurate slope variance for use in GO predictions. This choice of cutoff wavenumber is then applied in the composite surface theory for more realistic ocean spectra and compared with available experimental data. C1 Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. Ohio State Univ, Electrosci Lab, Columbus, OH 43210 USA. MIT, Dept Elect Engn, Cambridge, MA 02139 USA. MIT, Elect Res Lab, Cambridge, MA 02139 USA. Univ Washington, Electromagnet & Remote Sensing Lab, Dept Elect Engn, Seattle, WA 98195 USA. CALTECH, Jet Prop Lab, Radar Sci & Engn Sect, Pasadena, CA 91109 USA. RP Johnson, JT (reprint author), Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. EM johnson@ee.eng.ohio-state.edu; tsang1@ee.washington.edu NR 41 TC 59 Z9 62 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1998 VL 36 IS 1 BP 72 EP 83 DI 10.1109/36.655319 PG 12 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA YT522 UT WOS:000071615500007 ER PT J AU Nghiem, SV Kwok, R Yueh, SH Gow, AJ Perovich, DK Hsu, CC Ding, KH Kong, JA Grenfell, TC AF Nghiem, SV Kwok, R Yueh, SH Gow, AJ Perovich, DK Hsu, CC Ding, KH Kong, JA Grenfell, TC TI Diurnal thermal cycling effects on microwave signatures of thin sea ice SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE backscatter; brightness temperature; diurnal thermal cycle; sea ice ID COMPLEX-DIELECTRIC-CONSTANT; POLARIMETRIC SIGNATURES; LAYERED MEDIA; MODEL; FREQUENCIES; SCATTERERS; EXCHANGE; BRINE; SNOW AB To investigate effects of diurnal thermal cycles on C-band polarimetric backscatter and millimeter-wave emission from sea ice, we carried out a winter experiment at the outdoor Geophysical Research Facility (GRF) in the Cold Regions Research and Engineering Laboratory (CRREL), The ice sheet grew from open sea water to a thickness of 10 cm in 2.5 days, during which we took polarimetric backscatter data with a C-band scatterometer, interlaced with brightness temperature measurements at 90 GHz in conjunction with meteorological and sea ice characterizations. The initial ice growth in the late morning was slow due to high insolation. As the air temperature dropped during the night, the growth rate increased significantly, Air temperature changed drastically from about -12 to -36 degrees C between day and night, The diurnal thermal cycle repeated itself the next day and the growth rate varied in the same manner, Ice temperature profiles clearly show the diurnal response in the ice sheet with a lag of 2.5 h behind the time of the maximum short-wave incident solar radiation, The diurnal cycles are also evident in the millimeter-wave brightness temperature data, Measured sea ice backscatter revealed substantial diurnal variations up to 6 dB with repeatable cycles in synchronization with the temperature cycles and the brightness temperature modulations, The diurnal cycles in backscatter indicate that the dominant scattering mechanism related to thermodynamic processes in sea ice is reversible. A diurnal backscatter model based on sea ice electrodynamics and thermodynamics explains the observed diurnal signature. This work shows that diurnal effects are important for inversion algorithms to retrieve sea ice geophysical parameters from remote sensing data acquired with a satellite synthetic aperture radar (SAR) or scatterometer on sun-synchronous orbits. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. USA, Cold Reg Res & Engn Lab, Hanover, NH 03755 USA. MIT, Dept Elect Engn & Comp Sci & Res, Elect Lab, Cambridge, MA 02139 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. RP Nghiem, SV (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 31 TC 12 Z9 12 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1998 VL 36 IS 1 BP 111 EP 124 DI 10.1109/36.655322 PG 14 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA YT522 UT WOS:000071615500010 ER PT J AU Marshak, A Davis, A Cahalan, RF Wiscombe, W AF Marshak, A Davis, A Cahalan, RF Wiscombe, W TI Nonlocal independent pixel approximation: Direct and inverse problems SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID AVERAGED SOLAR FLUXES; BOUNDARY-LAYER CLOUDS; MARINE STRATOCUMULUS; RADIATIVE-TRANSFER; SCALE-INVARIANCE; SATELLITE; ALBEDO; PARAMETERIZATION AB The independent pixel approximation (IPA), which treats radiative properties of each pixel independently by using standard plane-parallel calculations preserves scale-invariance found in the analyses of the horizontal variability of liquid water in marine stratocumulus clouds, Several studies, however, report a violation of scale-invariance in LANDSAT cloud radiance fields that are much smoother than cloud structure on small scales, This shows a limitation of IPA on small scales: it is unable to simulate the smooth small-scale behavior that is due to the horizontal photon transport, This paper introduces a "nonlocal" independent pixel approximation (NIPA) that extends the ll)A by incorporating empirically the smoothing effects of horizontal interpixel fluxes through a convolution produce of the TPA and an approximate Green function for radiative transfer. We also address the inverse problem of cloud optical depth retrieval from satellite data, showing how NIPA can be used to overcome the limitations of current IPA-based methods at small scales. C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Marshak, A (reprint author), NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. RI Cahalan, Robert/E-3462-2012; Wiscombe, Warren/D-4665-2012; Marshak, Alexander/D-5671-2012 OI Cahalan, Robert/0000-0001-9724-1270; Wiscombe, Warren/0000-0001-6844-9849; NR 39 TC 49 Z9 50 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1998 VL 36 IS 1 BP 192 EP 205 DI 10.1109/36.655329 PG 14 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA YT522 UT WOS:000071615500017 ER PT J AU Los, SO AF Los, SO TI Estimation of the ratio of sensor degradation between NOAA AVHRR channels 1 and 2 from monthly NDVI composites SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE AVHRR; desert calibration; NDVI composites; sensor degradation ID VEGETATION INDEX; DATA SET; CALIBRATION; DESERT; OCEAN AB Vegetation monitoring, based on the normalized difference vegetation index (NDVI) calculated hom the Advanced Very High Resolution Radiometer (AVHRR) channels 1 and 2 data, requires continuous updates of calibration coefficients to correct for the sensor degradation in these channels. A method was developed to estimate calibration coefficients with monthly composited NDVI data from desert targets without recourse to the component channels 1 and 2 data, The method was tested on NDVI data from the AVHRR onboard the NOAA-7, -9, and -11 satellites for the period from 1982 until 1993. The results of the method outlined in this paper correlated high r, between 0.94 and 0.95, with the results from other studies that estimated sensor degradation for the individual AVHRR bands. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Los, SO (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. EM sietse@scirocco.gsfc.nasa.gov RI Los, Sietse/G-8985-2012; OI Los, Sietse/0000-0002-1325-3555 NR 23 TC 63 Z9 64 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1998 VL 36 IS 1 BP 206 EP 213 DI 10.1109/36.655330 PG 8 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA YT522 UT WOS:000071615500018 ER PT J AU Baldwin, DG Emery, WJ Cheeseman, PB AF Baldwin, DG Emery, WJ Cheeseman, PB TI Higher resolution earth surface features from repeat moderate resolution satellite imagery SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE algorithms; deconvolution; image analysis; image processing; modeling; satellites ID SPATIAL-RESOLUTION; AVHRR DATA AB This paper demonstrates that a high-resolution reflectivity model used in conjunction with an instrument point-spread function (PSF) can both determine georegistration parameters of coarse resolution sensors and improve the spatial resolution by compositing noncoincident repeat satellite data, To demonstrate this ability, an ideal location is selected and several first principle assumptions are made to simplify the reflectivity model, Twenty-three l-km advanced very high-resolution radiometer (AVHRR) images are composited by using a Bayesian statistical sampling technique to yield estimates of a simple terrain-based reflectivity model with 180-m resolution, The terrain values are determined from a 90-m resolution digital elevation model (DEM). The Bayesian technique uses the AVHRR data to iteratively determine the most likely values for the model spectral albedos contained within an AVHRR field of view, Model predicted radiances far the repeat AVHRR footprints are computed by integrating: model albedo values over the AVHRR PSF, As a first-order verification, simulated AVHRR reflectivities are shown to reconstruct well a smoothly varying prescribed albedo held, Comparisons of the composited real AVHRR image result with Landsat Multi Spectral Scanner (MSS) data show that the model reconstruction resolves surface features, which are not resolved in a single AVHRR image. C1 Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA. NASA, Ames Res Ctr, Artificial Intelligence Branch, Adv Comp Sci Res Inst, Moffett Field, CA 94035 USA. RP Baldwin, DG (reprint author), Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA. OI Emery, William/0000-0002-7598-9082 NR 12 TC 9 Z9 9 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1998 VL 36 IS 1 BP 244 EP 255 DI 10.1109/36.655333 PG 12 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA YT522 UT WOS:000071615500021 ER PT J AU Imel, DA AF Imel, DA TI Accuracy of the residual-delay absolute-phase algorithm SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE absolute; correlation phase; IFSAR; MSAR; interferometry; residual delay; SAR ID INTERFEROMETRY AB An absolute-phase algorithm is used in an interferometric radar mapper to determine the unknown constant number of cycles of phase difference after phase un unwrapping and,;hus. the absolute topography. Using a model and a simulation, I compute the accuracy of one such algorithm and compare it to the results for an actual system, The algorithm's accuracy for other systems is predicted. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Imel, DA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Imel, David/0000-0002-6118-7396 NR 6 TC 7 Z9 7 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1998 VL 36 IS 1 BP 322 EP 324 DI 10.1109/36.655344 PG 3 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA YT522 UT WOS:000071615500032 ER PT J AU Dorai, C Wang, G Jain, AK Mercer, C AF Dorai, C Wang, G Jain, AK Mercer, C TI Registration and integration of multiple object views for 3D model construction SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE automatic 3D object modeling; free-form objects; registration; view integration; range images; digital interferometry ID RANGE VIEWS AB Automatic 3D object model construction is important in applications ranging from manufacturing to entertainment, since CAD models of existing objects may be either unavailable or unusable. We describe a prototype system for automatically registering and integrating multiple views of objects from range data. The results can then be used to construct geometric models of the objects. New techniques for handling key problems such as robust estimation of transformations relating multiple views and seamless integration of registered data to form an unbroken surface have been proposed and implemented in the system. Experimental results on real surface data acquired using a digital interferometric sensor as well as a laser range scanner demonstrate the good performance of our system. C1 Michigan State Univ, Dept Comp Sci, E Lansing, MI 48824 USA. NASA, Lewis Res Ctr, Opt Technol Branch, Cleveland, OH 44135 USA. RP Michigan State Univ, Dept Comp Sci, E Lansing, MI 48824 USA. EM dorai@cps.msu.edu; wanggang@cps.msu.edu; jain@cps.msu.edu; cmercer@lerc.nasa.gov NR 17 TC 119 Z9 135 U1 1 U2 8 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0162-8828 EI 1939-3539 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD JAN PY 1998 VL 20 IS 1 BP 83 EP 89 DI 10.1109/34.655652 PG 7 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA YV876 UT WOS:000071872400008 ER PT J AU Easterbrook, S Lutz, R Covington, R Kelly, J Ampo, Y Hamilton, D AF Easterbrook, S Lutz, R Covington, R Kelly, J Ampo, Y Hamilton, D TI Experiences using lightweight formal methods for requirements modeling SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Article DE software requirements; formal methods; verification and validation; fault protection software; NASA AB This paper describes three case studies in the lightweight application of formal methods to requirements modeling for spacecraft fault protection systems. The case studies differ from previously reported applications of formal methods in that formal methods were applied very early in the requirements engineering process, to validate the evolving requirements. The results were fed back into the projects, to improve the informal specifications. For each case study, we describe what methods were applied, how they were applied, how much effort was involved, and what the findings were. In all three cases, formal methods enhanced the existing verification and validation processes, by testing key properties of the evolving requirements, and helping to identify weaknesses. We conclude that the benefits gained from early modeling of unstable requirements more than outweigh the effort needed to maintain multiple representations. C1 NASA, IV&V Facil, Fairmont, WV 26554 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. NEC Corp Ltd, Tokyo, Japan. Hewlett Packard Corp, San Diego, CA 92127 USA. RP Easterbrook, S (reprint author), NASA, IV&V Facil, 100 Univ Dr, Fairmont, WV 26554 USA. EM steve@atlantis.ivv.nasa.gov; rlutz@cs.iastate.edu; richard.g.covington@jpl.nasa.gov; john.c.kelly@jpl.nasa.gov; KHF00272@niftyserve.or.jp; david_hamilton@hp.com NR 27 TC 49 Z9 49 U1 0 U2 4 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0098-5589 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD JAN PY 1998 VL 24 IS 1 BP 4 EP 14 DI 10.1109/32.663994 PG 11 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA YZ353 UT WOS:000072245900003 ER PT B AU Howard, A Padgett, C Liebe, CC AF Howard, A Padgett, C Liebe, CC GP IEEE TI A multi-stage neural network for automatic target detection SO IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE LA English DT Proceedings Paper CT 2nd IEEE World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP Int Neural Network Soc, IEEE, Neural Networks Council, IEEE, Alaska Sect DE automatic target recognition; neural network; detection AB Automatic Target Recognition (ATR) involves processing two-dimensional images for detecting, classifying, and tracking targets. The first stage in ATR is the detection process. This involves discrimination between target and non-target objects in a scene. In this paper, we shall discuss a novel approach which addresses the target detection process. This method extracts relevant object features utilizing principal component analysis. These extracted features are then presented to a multi-stage neural network which allows an overall increase in detection rate, while decreasing the false positive alarm rate. We shall discuss the techniques involved and present some detection results that have been implemented on the multi-stage neural network. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Howard, A (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4860-5 PY 1998 BP 231 EP 236 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Medical Informatics; Neurosciences SC Computer Science; Engineering; Medical Informatics; Neurosciences & Neurology GA BL15D UT WOS:000074493400043 ER PT B AU Duong, TA Thomas, T Daud, T Thakoor, A Suddarth, S AF Duong, TA Thomas, T Daud, T Thakoor, A Suddarth, S GP IEEE TI The hardware results of a 64x64 analog input array for a 3-dimensional neural network processor SO IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE LA English DT Proceedings Paper CT 2nd IEEE World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP Int Neural Network Soc, IEEE, Neural Networks Council, IEEE, Alaska Sect C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Duong, TA (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4860-5 PY 1998 BP 593 EP 597 PG 5 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Medical Informatics; Neurosciences SC Computer Science; Engineering; Medical Informatics; Neurosciences & Neurology GA BL15D UT WOS:000074493400109 ER PT B AU Tawel, R Aranki, N Puskorius, GV Marko, KA Feldkamp, LA James, JV Jesion, G Feldkamp, TM AF Tawel, R Aranki, N Puskorius, GV Marko, KA Feldkamp, LA James, JV Jesion, G Feldkamp, TM GP IEEE TI Custom VLSI ASIC for automotive applications with recurrent networks SO IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE LA English DT Proceedings Paper CT 2nd IEEE World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP Int Neural Network Soc, IEEE, Neural Networks Council, IEEE, Alaska Sect AB Demands on the performance of vehicle control and diagnostic systems are steadily increasing as a consequence of stiff global competition and government mandates. Neural networks provide a means of creating control and diagnostic strategies that will help in meeting these demands efficiently and robustly. This paper describes a VLSI design that permits such networks to be executed in real time as well as the application, misfire detection, that served as a focus for the collaborative effort. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tawel, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4860-5 PY 1998 BP 598 EP 602 PG 5 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Medical Informatics; Neurosciences SC Computer Science; Engineering; Medical Informatics; Neurosciences & Neurology GA BL15D UT WOS:000074493400110 ER PT B AU Tumer, K Ghosh, J AF Tumer, K Ghosh, J GP IEEE TI Classifier combining through trimmed means and order statistics SO IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE LA English DT Proceedings Paper CT 2nd IEEE World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP Int Neural Network Soc, IEEE, Neural Networks Council, IEEE, Alaska Sect AB Combining the outputs of multiple neural networks has led to substantial improvements in several difficult pattern recognition problems. In this article, we introduce and investigate robust combiners, a family of classifiers based on order statistics. We focus our study to the analysis of the decision boundaries, and how these boundaries are affected by order statistics combiners. In particular, we show that using the ith order statistic, or a linear combination of the ordered classifier outputs is quite beneficial in the presence of outliers or uneven classifier performance. Experimental results on several public domain data sets corroborate these findings. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Tumer, K (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4860-5 PY 1998 BP 757 EP 762 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Medical Informatics; Neurosciences SC Computer Science; Engineering; Medical Informatics; Neurosciences & Neurology GA BL15D UT WOS:000074493400139 ER PT B AU Stassinopoulos, D AF Stassinopoulos, D GP IEEE TI Self-organization, scaling, and parallelism SO IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE LA English DT Proceedings Paper CT 2nd IEEE World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP Int Neural Network Soc, IEEE, Neural Networks Council, IEEE, Alaska Sect AB The problem of learning in the absence of external intelligence is discussed in the context of a simple model. The model departs from the traditional gradient-descent based approaches to learning by operating at a highly susceptible "critical" state, with low activity and sparse connections between firing neurons. Quantitative studies in the context of two simple association tasks demonstrate that the elements of the model that are essential for self-organized learning are also essential for its scaling performance and parallelism. C1 NASA, Ames Res Ctr, Computat Sci Div, Neuroengn Lab, Moffett Field, CA 94035 USA. RP Stassinopoulos, D (reprint author), NASA, Ames Res Ctr, Computat Sci Div, Neuroengn Lab, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4860-5 PY 1998 BP 2039 EP 2044 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Medical Informatics; Neurosciences SC Computer Science; Engineering; Medical Informatics; Neurosciences & Neurology GA BL15D UT WOS:000074493400372 ER PT B AU Simard, M AF Simard, M BE Stein, TI TI Extraction of information and speckle noise reduction in SAR images using the wavelet transform SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This paper presents a method for extracting information from SAR images using the wavelet transform. It is shown experimentally that the shape of the wavelet can be chosen in order to extract different features in the image. Then a new method based on the wavelet transform is used to reduce speckle noise in model SAR image. The result is compared with the more traditional wavelet shrinking method. C1 NASA, Jet Prop Lab, Pasadena, CA 91109 USA. RP Simard, M (reprint author), NASA, Jet Prop Lab, Mail Stop 300-227,4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Simard, Marc/0000-0002-9442-4562 NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 4 EP 6 DI 10.1109/IGARSS.1998.702761 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100002 ER PT B AU Meneghini, R Liao, L Iguchi, T AF Meneghini, R Liao, L Iguchi, T BE Stein, TI TI Effective dielectric constants of melting hydrometeors and their use in radar bright-band models SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Meneghini, R (reprint author), NASA, Goddard Space Flight Ctr, Code 975, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 147 EP 149 DI 10.1109/IGARSS.1998.702829 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100049 ER PT B AU Joyce, AT AF Joyce, AT BE Stein, TI TI Integration of earth observing data with biological and physical science curricula SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Educ Univ Affairs Off, Stennis Space Ctr, MS 39529 USA. RP Joyce, AT (reprint author), NASA, Educ Univ Affairs Off, Mail Code AA10, Stennis Space Ctr, MS 39529 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 244 EP 246 DI 10.1109/IGARSS.1998.702866 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100081 ER PT B AU Sullivan, NG AF Sullivan, NG BE Stein, TI TI Improving student achievement in math and science SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Educ Univ Affairs Off, Stennis Space Ctr, MS 39529 USA. RP Sullivan, NG (reprint author), NASA, Educ Univ Affairs Off, Mail Code AA10, Stennis Space Ctr, MS 39529 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 247 EP 249 DI 10.1109/IGARSS.1998.702867 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100082 ER PT B AU Williams, DL Irons, JR Barker, JL Markham, BL Pedelty, JA AF Williams, DL Irons, JR Barker, JL Markham, BL Pedelty, JA BE Stein, TI TI Landsat 7: Maintaining landsat data continuity into the 21st century SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The Land Remote Sensing Policy Act of 1992 identified Landsat data continuity as the fundamental goal of the Landsat 7 program. Furthermore, a Presidential Decision Directive in 1994 placed the development and operation of the Landsat 7 program in the domain of three Federal agencies: NASA has the responsibility to build and launch the spacecraft and instrument package; NOAA is charged with the day-to-day operational management of the mission; and the USGS EROS Data Center (EDC) will receive, archive, process and distribute Landsat 7 data products on behalf of NOAA. The Landsat 7 program, on target for a launch in early 1999, has been designed to preserve data continuity by placing the Enhanced Thematic Mapper Plus (ETM+) sensor in orbit The ETM+ is based on the heritage design of the Thematic Mapper (TM) instruments flown aboard Landsat 4/5, and it will provide: (a) repetitive, synoptic coverage of global land surfaces; (b) spectral bands in the visible, near IR, shortwave IR, and thermal IR regions; (c) spatial resolution of 15m, 30m and 60m; and (d) significantly improved absolute radiometric calibration. Significant enhancements have also been incorporated into the ground data processing system to be located at EDC. Plans call for the daily acquisition and archival of 250 scenes of data at EDC, with a goal of refreshing archival coverage of the global land mass periodically. The system is being sized to generate up to 100 systematically corrected Level 1 scene products per day, and these data will be sold for less than $600 per scene. An Image Assessment System (IAS) is also being developed to facilitate data quality assessment and to maintain up-to-date calibration of the ETM+ sensor throughout the duration of the mission. This paper will provide a very brief overview and status update on this significant component of NASA's Earth Science Program. For more information about the Landsat 7 program, please access the Landsat Gateway web sire at: http://landsat7.gsfc.nasa.gov. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Williams, DL (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. RI Irons, James/D-8535-2012; Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 0 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 256 EP 258 DI 10.1109/IGARSS.1998.702870 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100085 ER PT B AU Fishtahler, L AF Fishtahler, L BE Stein, TI TI Concept for an HDF-EOS image data construct SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB NASA's Earth Science Data and Information Systems (ESDIS) Project has promulgated a standard format for the EOS Data and Information System (EOSDIS) Standard Data Products, HDF-EOS. HDF-EOS is based on the National Center for Supercomputing Applications (NCSA) Hierarchical Data Format (HDF). At present HDF-EOS provides for "Swath," "Point," and "Grid" data constructs. This paper provides a concept for an "image" data construct. Essential components include image data, palettes, and geolocation information; in addition a number of optional components are described. This paper sets forth a number of criteria to be considered in the development of this new standard construct, and discusses the options for the approach to standardization. This paper provides sketches of an implementation (using HDF constructs) of the main features of the concepts, and references to WWW Pages that provide examples. C1 NASA, Goddard Space Flight Ctr, Comp Sci Corp, Greenbelt, MD 20771 USA. RP Fishtahler, L (reprint author), NASA, Goddard Space Flight Ctr, Comp Sci Corp, Code 922, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 307 EP 308 DI 10.1109/IGARSS.1998.702887 PG 2 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100102 ER PT B AU Le Moigne, J Xia, W Chalermwat, P El-Ghazawi, T Mareboyana, M Netanyahu, N Tilton, JC Campbell, WJ Cromp, RF AF Le Moigne, J Xia, W Chalermwat, P El-Ghazawi, T Mareboyana, M Netanyahu, N Tilton, JC Campbell, WJ Cromp, RF BE Stein, TI TI First evaluation of automatic image registration methods SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB As the need for automating registration techniques is recognized, we feel that there is a need to survey all the registration methods which may be applicable to Earth and space science problems and to evaluate their performances on a large variety of existing remote sensing data as well as on simulated data of soon-to-be-flown instruments. In this paper we present the first steps towards this quantitative evaluation: a few automatic image registration algorithms are described and first results of their evaluation are presented for three different datasets. C1 NASA, Goddard Space Flight Ctr, USRA, Ctr Excellence Space Data & Informat Sci, Greenbelt, MD 20771 USA. RP Le Moigne, J (reprint author), NASA, Goddard Space Flight Ctr, USRA, Ctr Excellence Space Data & Informat Sci, Code 930-5, Greenbelt, MD 20771 USA. NR 0 TC 4 Z9 4 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 315 EP 317 DI 10.1109/IGARSS.1998.702890 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100105 ER PT B AU Skofronick-Jackson, GM Wang, JR AF Skofronick-Jackson, GM Wang, JR BE Stein, TI TI Wideband dual-altitude TOGA-COARE observations SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 Univ Space Res Assoc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Skofronick-Jackson, GM (reprint author), Univ Space Res Assoc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 369 EP 371 DI 10.1109/IGARSS.1998.702908 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100123 ER PT B AU Imhoff, ML Lawrence, W Carson, S Johnson, P Holford, W Hyer, J May, L Harcombe, P AF Imhoff, ML Lawrence, W Carson, S Johnson, P Holford, W Hyer, J May, L Harcombe, P BE Stein, TI TI An airborne low frequency radar sensor for vegetation biomass measurement SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB A synthetic aperture radar sensor operating in the 120 to 80 MHz frequency range was developed for the purpose of measuring heavy forest biomass for carbon sequestration studies. An experiment was conducted on forest stands with different biomass densities to identify the frequency range required to separate stands with biomass densities above 100 metric tons per hectare (tons/ha) above -ground dry biomass. The results of the experiment are shown and the resulting sensor system design is explained. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Imhoff, ML (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 469 EP 471 DI 10.1109/IGARSS.1998.702942 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100154 ER PT B AU Kim, Y van Zyl, J AF Kim, Y van Zyl, J BE Stein, TI TI Ionospheric effects on polarimetric and interferometric space-borne SAR SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB In recent years, both polarimetric and interferometric SAR techniques have provided important scientific results. To be useful for science applications, these techniques require precise phase and amplitude calibration. In order to cover large areas using these techniques, it is necessary to use a space-borne SAR. Due to ionospheric disturbance, a space-borne SAR may not be able to produce data useful for science applications. In this paper, we present ionospheric effects on polarimetric and interferometric SAR images, especially at lower frequencies. First, we derive analytic equations to investigate ionospheric effects on both range and azimuth compressions. Then, using these equations, we examine important parameters such as pulse dispersion, time delay, and loss of azimuth resolution. We will also present possible correction schemes to compensate ionospheric disturbance. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kim, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 472 EP 474 DI 10.1109/IGARSS.1998.702943 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100155 ER PT B AU Siqueira, P Freeman, T AF Siqueira, P Freeman, T BE Stein, TI TI Source ambiguities for imaging and interferometric SAR SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB One of the greatest costs of any spaceborne mission is the total instrument mass. For SAR, one third of the mass is typically related to the antenna structure, whose elevation and azimuth dimensions are used to increase the signal to noise ratio as well as to reduce the presence of spurious signals. As the wavelength increases, so too does the antenna dimensions to achieve equivalent performance. Thus, the antenna for a P-band mission is likely to be several times larger than that for, say, an L-band, mission. The L-band antennas for SIR-C and JERS-1 for example are on the order of 12m in azimuth and 3/2.5 meters in elevation. An equivalent P-band antenna would be more than three times larger (but, as will be shown, not necessarily in the azimuth dimension). Understanding the tradeoffs between signal to noise ratio, ambiguous sources and the antenna dimensions is a key to producing a cost effective low frequency mission design. In this short paper, we focus on the presence of source ambiguities, or those spurious signals arising from ground targets which are imaged concurrently with the intended target. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Siqueira, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 478 EP 480 DI 10.1109/IGARSS.1998.702945 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100157 ER PT B AU Nous, AP AF Nous, AP BE Stein, TI TI The OpenDOOR project: A digital object observatory and repository on the World Wide Web SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 Univ Pittsburgh, NASA, Educator Resource Ctr, Pittsburgh, PA 15260 USA. RP Nous, AP (reprint author), Univ Pittsburgh, NASA, Educator Resource Ctr, 4K24 FQ,230 So Bouquet St, Pittsburgh, PA 15260 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 536 EP 538 DI 10.1109/IGARSS.1998.702963 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100175 ER PT B AU Dunagan, SE Hammer, PD Slye, RE Sullivan, DV Smith, WH AF Dunagan, SE Hammer, PD Slye, RE Sullivan, DV Smith, WH BE Stein, TI TI Interferometric imagery from a solar powered RPV SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This Paper describes the design, integration, and deployment of a compact, high-spectral-resolution imaging interferometer built specifically for use on the Pathfinder [1] solar powered remotely piloted aircraft (RPA) that has been developed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. Emphasis is placed on the engineering challenges associated with RPA instruments, including low power and weight constraints, extreme thermal and pressure environment, and remote operation. Sample data are presented that illustrate the strengths and weaknesses of the composite RPA/scanned interferometer remote sensing system. C1 NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. RP Dunagan, SE (reprint author), NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Mail Stop 242-4, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 645 EP 647 DI 10.1109/IGARSS.1998.699538 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100210 ER PT B AU Masuoka, E Tilmes, C Noll, C Samadi, S Ruggiero, N Englemeyer, W Schols, J AF Masuoka, E Tilmes, C Noll, C Samadi, S Ruggiero, N Englemeyer, W Schols, J BE Stein, TI TI Building a data system to produce, archive and distribute global data products from MODIS SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB An emergency backup processing system for NASA's EOSDIS was developed to produce, archive and distribute global science products from the MODerate resolution Imaging Spectroradiometer (MODIS) instrument which will be launched on the EOS AM-I satellite. This system will produce up to 400GB of MODIS products per day and distribute up to 500GB of data via the Internet and on DLT and Exabyte tapes. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Masuoka, E (reprint author), NASA, Goddard Space Flight Ctr, Code 922, Greenbelt, MD 20771 USA. RI Tilmes, Curt/D-5637-2012; Noll, Carey/D-8884-2012; OI Tilmes, Curt/0000-0002-6512-0287 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 692 EP 696 DI 10.1109/IGARSS.1998.699553 PG 5 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100225 ER PT B AU West, RD Yueh, SH AF West, RD Yueh, SH BE Stein, TI TI Case studies of airborne radiometer signals over the ocean SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This paper presents some case studies of multi-frequency multi-polarization brightness temperatures obtained in a variety of surface and atmospheric conditions. All of the channels showed the characteristic sinusoidal modulation with azimuth caused by wind stress on the ocean surface. The lowest frequency channel (10 GHz) seemed to show more modulation than other frequencies, especially in the U channel. The U channel was the least sensitive to the atmospheric conditions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP West, RD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 748 EP 750 DI 10.1109/IGARSS.1998.699571 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100243 ER PT B AU Middleton, EM Deluca, AJ Chan, SS Rusin, RJ AF Middleton, EM Deluca, AJ Chan, SS Rusin, RJ BE Stein, TI TI Relationships between leaf chlorophyll and spectral optical properties in hazelnut and aspen trees at BOREAS sites in Saskatchewan, Canada SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Leaf characteristics, including chlorophyll a content and spectral optical properties, were examined in boreal forest foliage over the growing season during the 1994 BOReal Ecosystem-Atmosphere Study (BOREAS) conducted in Saskatchewan, Canada. We present the results for two deciduous broadleaf species associated with aspen stands: aspen (Populus tremuloides) and hazelnut (Corylus cornata Marsh). C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. RP Middleton, EM (reprint author), NASA, Goddard Space Flight Ctr, Terr Phys Lab, Code 923, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 891 EP 893 DI 10.1109/IGARSS.1998.699617 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100289 ER PT B AU Montgomery, BC Grieco, J Masuoka, PM Roberts, D Rejmankova, E Alonzo, Y Andre, R Lenares, H Achee, N Pope, K Franklin, S AF Montgomery, BC Grieco, J Masuoka, PM Roberts, D Rejmankova, E Alonzo, Y Andre, R Lenares, H Achee, N Pope, K Franklin, S BE Stein, TI TI A remote sensing analysis of vector abundance and malaria risk associated with selected villages in southern Belize, CA SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB We report on an integrated methodology of remote sensing and geographic information systems (GIS) to assess the risk of malaria transmission in the villages of southern Belize. Studies were initiated in 1990 that characterized the environmental requirements of the important Anopheles mosquitoes in Belize. A data set of environmental criteria was compiled to assess relative risk for the villages. Risk was defined as the presence and abundance of vector mosquitoes for malaria transmission based on environmental criteria. An integrated GIS was employed for differentiating villages of high and low risk. The villages were ranked according to several factors, e.g., elevation, distance to major rivers or streams, and landuse. The predictions included the identification of the 10 highest and the 10 lowest "villages of risk." A field survey team was then employed to test presence/abundance of the three important vector species in each of the 20 villages. C1 Uniformed Serv Univ Hlth Sci, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Montgomery, BC (reprint author), Uniformed Serv Univ Hlth Sci, NASA, Goddard Space Flight Ctr, Code 922, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1053 EP 1054 DI 10.1109/IGARSS.1998.699670 PG 2 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100342 ER PT B AU Kim, YJ Pak, KS Hsu, CS Callahan, PS Dunbar, RS Hsiao, SV Zhang, AZ AF Kim, YJ Pak, KS Hsu, CS Callahan, PS Dunbar, RS Hsiao, SV Zhang, AZ BE Stein, TI TI Improving the sea surface wind retrieval algorithm for NASA scatterometers using atmospheric boundary layer models SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The use of an atmospheric boundary layer (ABL) model is investigated to improve wind retrieval algorithms for NASA scatterometer projects. The ambiguity in wind direction retrieved from scatterometer measurements is removed with the aid of physical directional information obtained from the ABL model. This approach is based on the observation that sea level pressure is scalar and its field is more coherent than the corresponding wind held, and also that the measurement errors of sea level pressure are small compared with those of the retrieved wind vectors. A wind field obtained from the scatterometer measurements is first used to derive a pressure field by using an ABL model. After properly filtering small-scale noise in the derived pressure field, the wind field is retrieved by using an inverted ABL model. This derived wind information is then used to remove wind vector ambiguities. It is found that the ambiguity removal skill can be improved when the new scheme is used properly in conjunction with the median filter adopted for the scatterometer wind dealiasing. Moreover, it is believed that the new methodology will mitigate the dependency of the wind processing algorithm on external inputs, i.e., products of numerical weather prediction systems, which reveal deficiencies in accurately resolving some smaller scale and/or sporadic atmospheric phenomena. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kim, YJ (reprint author), CALTECH, Jet Prop Lab, Mail Stop 300-319,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1115 EP 1117 DI 10.1109/IGARSS.1998.699690 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100362 ER PT B AU Sandmeier, SR Middleton, EM Deering, DW AF Sandmeier, SR Middleton, EM Deering, DW BE Stein, TI TI Comparing hyperspectral BRDF data of grass derived from three different laboratory- and field-goniometer systems SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The study compares hyperspectral BRDF data of grass vegetation acquired in the laboratory and field with three different goniometric systems. Reflectance measurements of relatively sparse prairie grass were comparable to measurements taken over a dense grass lawn surface only after correction for the soil influences determined by the canopy gap probability function. Nadir-normalized BRDP data consistently revealed a strong wavelength dependence. In addition, a distinctive relationship between BRDF effects and the canopy reflectance signature was observed in all three grass canopies. These phenomena are due to multiple scattering effects which occur within the grass canopy. Since the canopy structure and multiple scattering effects are ultimately related, the potential for deriving canopy architecture parameters from hyperspectral BRDF data is suggested. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Sandmeier, SR (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1225 EP 1227 DI 10.1109/IGARSS.1998.691358 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100397 ER PT B AU Qin, WH Gerstl, SAW Deering, DW AF Qin, WH Gerstl, SAW Deering, DW BE Stein, TI TI Examination of relations between NDVI and vegetation properties using simulated MISR data SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Relations between NDVI and FAI (foliage area index) and fAPAR (fraction of absorbed photosynthetically active radiation) are examined using simulated MISR data. More linear, statistically significant relationships between FN (fAPAR) and shaded (sunlit) foliage fraction are identified. The dominant role of the sunlit scene component in determining scene NDVI is physically interpreted, and a more effective (accurate) way to use NDVI (to estimate FAI aid fAPAR) is also suggested. C1 Univ Maryland, Dept Geog, NASA, GSFC, Greenbelt, MD 20771 USA. RP Qin, WH (reprint author), Univ Maryland, Dept Geog, NASA, GSFC, Code 923, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 3 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1243 EP 1245 DI 10.1109/IGARSS.1998.691364 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100403 ER PT B AU Treuhaft, RN Moghaddam, M AF Treuhaft, RN Moghaddam, M BE Stein, TI TI A unified analysis of radar interferometry and polarimetry for the estimation of forest parameters SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Treuhaft, RN (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-227, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1373 EP 1375 DI 10.1109/IGARSS.1998.691428 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100445 ER PT B AU Montgomery, DR Pichel, W Clemente-Calon, P AF Montgomery, DR Pichel, W Clemente-Calon, P BE Stein, TI TI The use of satellite-based SAR in support of fisheries enforcement applications SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Satellite-based synthetic aperture radar (SAR) may provide a unique surveillance and monitoring capability to augment existing fisheries aircraft and patrol vessel reconnaissance methods. Moreover, satellite-based SAR may prove to be an effective tool to observe the effects of manmade land disturbances to fisheries habitat. Three experiments were undertaken to assess the utility of satellite-based SAR in fisheries enforcement applications. One experiment involved the detection of fishing vessels and their wakes. Undersea acoustic measurements were made to study the effect of the blended SAR and acoustic signature data on detection and tracking of ships. A second experiment assessed the capability of SAR to detect large-scale pelagic driftnets. A third experiment involved SAR observations of sensitive salmon spawning and nursery habitat in the Pacific Northwest. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Montgomery, DR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 233-304, Pasadena, CA 91109 USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1388 EP 1390 DI 10.1109/IGARSS.1998.691438 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100450 ER PT B AU Nghiem, SV Leshkevich, GA Kwok, R AF Nghiem, SV Leshkevich, GA Kwok, R BE Stein, TI TI C-band polarimetric backscatter observations of Great Lakes ice SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Two experiments were carried out during the 1997 winter season across the Straits of Mackinac and Lake Superior. C-band radar backscatter signatures of various ice types and open water were measured from U.S. Coast Guard Ice Breaker vessels together with ground truth data. Polarimetric backscatter data were obtained at incident angles up to 60 degrees for all polarizations. Backscatter signatures of 20 ice types/conditions were collected along the Coast Guard ship tracks in February and March 1997. The backscatter data set with in-situ ice characteristic parameter measurements are to be used in the development of the ice mapping algorithms using satellite SAR, data over the Great Lakes. The results at C-band frequency for multiple incident angles and multiple polarizations are applicable to the current ERS and RADARSAT Synthetic Aperture Radars (SAR) and the future ENVISAT SAR. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nghiem, SV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-235, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1400 EP 1402 DI 10.1109/IGARSS.1998.691450 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100454 ER PT B AU Ranson, KJ Kaufman, Y Herring, D Collatz, GJ Bordi, F Tsay, SC AF Ranson, KJ Kaufman, Y Herring, D Collatz, GJ Bordi, F Tsay, SC BE Stein, TI TI Overview of EOS AM-1 platform and science SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB NASA's Earth Observing System is poised to launch the first major platform for Earth remote sensing, EOS AM-I. The platform, scheduled for launch in late 1998, will have five instruments and acquire global data for a wide variety of scientific studies of the Earth's land, oceans, and atmosphere. This paper discusses the unique technological advances incorporated into the design of the platform. The key Earth System Science observations are highlighted along with the plans for science outreach activities. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ranson, KJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Ranson, Kenneth/G-2446-2012; Tsay, Si-Chee/J-1147-2014; collatz, george/D-5381-2012 OI Ranson, Kenneth/0000-0003-3806-7270; NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1442 EP 1444 DI 10.1109/IGARSS.1998.691490 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100467 ER PT B AU Diner, DJ AF Diner, DJ BE Stein, TI TI Update on the status of the MISR and AirMISR experiments SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The Multi-angle Imaging SpectroRadiometer (MISR) instrument is scheduled for launch in 1998 aboard the Earth Observing System (EOS) AM spacecraft. MISR consists of nine pushbroom cameras, and will provide global coverage in four visible/near-infrared spectral bands. This measurement strategy provides systematic multi-angle imagery of the Earth for studies of aerosols, surface radiation, and clouds. AirMISR, an airborne MISR simulator fabricated using a spare MISR camera, has flown on NASA ER-2 aircraft during 1997 and 1998 and obtained a number of multi-angle image sets. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Diner, DJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 169-237, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1448 EP 1450 DI 10.1109/IGARSS.1998.691496 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100469 ER PT B AU Tait, A Hall, D Foster, J Chang, A AF Tait, A Hall, D Foster, J Chang, A BE Stein, TI TI High frequency passive microwave radiometry over a snow-covered surface in Alaska SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Millimeter-wave Imaging Radiometer (MIR) data (ranging in frequency from 89 GHz to 325 GHz) collected from NASA ER-2 flights over Alaska in April 1995, are used to identify clouds, vegetation type, and snow cover. The procedure used is as follows : 1.) Determine whether a purely MIR-based cloud detection scheme is possible over a snow-covered surface; 2.) Analyze the influence of changing vegetation type on the brightness temperatures; and 3.) Compare completely snow-covered scenes with partially snow-covered and snow-free regions for cloudy and clear sky periods to determine whether varying snow conditions affect the MIR data. Results show that the determination of cloudy pixels over a snow-covered surface is not possible using a simple brightness temperature threshold technique. Furthermore, it is concluded that while no statistical discrimination between specific vegetation classes can be made, statistical significance is obtained when the vegetation is grouped into two classes only, for example vegetated and barren. It is also shown that the state of the snow cover (complete coverage; melting; or patchy) has a distinct affect on these results. C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RP Tait, A (reprint author), NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Code 974, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1518 EP 1520 DI 10.1109/IGARSS.1998.691557 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100491 ER PT B AU Hall, DK Foster, JL Salomonson, VV Klein, AG Chien, JYL AF Hall, DK Foster, JL Salomonson, VV Klein, AG Chien, JYL BE Stein, TI TI Error analysis for global snow-cover mapping in the Earth Observation System (EOS) era SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Following the launch of the Earth Observing System (EOS) satellite platform, daily, global snow-cover mapping will be performed automatically at a spatial resolution of 500 m using Moderate Resolution Imaging Spectroradiometer (MODIS) data. In order to estimate the accuracy of the MODIS snow maps, the Northern Hemisphere was divided into 7 land-cover classes and water, and expected errors in mapping snow were calculated for each of the 7 classes using the average monthly snowline position. The errors are found primarily in land covers composed of forests. Maximum monthly snow-mapping errors are expected to range from 5 - 9% for North America, and from 5 - 10% for Eurasia. The largest errors are expected when snow coverage in the Boreal Forest is greatest. The maximum aggregated snow-mapping error for the Northern Hemisphere is expected to be about 7.5%. Error estimates will be refined after the first full year that MODIS data are available. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hall, DK (reprint author), NASA, Goddard Space Flight Ctr, Code 974, Greenbelt, MD 20771 USA. RI Hall, Dorothy/D-5562-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1524 EP 1526 DI 10.1109/IGARSS.1998.691562 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100493 ER PT B AU Harding, DJ AF Harding, DJ BE Stein, TI TI Airborne lidar observations of canopy structure at the BOREAS tower flux sites SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Harding, DJ (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 921, Greenbelt, MD 20771 USA. RI Harding, David/F-5913-2012 NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1550 EP 1552 DI 10.1109/IGARSS.1998.691589 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100501 ER PT B AU Nelson, R Kalshoven, J Harding, D AF Nelson, R Kalshoven, J Harding, D BE Stein, TI TI Attempts to estimate LAI using airborne flashlamps and lasers SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Two aircraft instruments, one a flashlamp/spectrometer - AVIS, and the other a ranging laser - SLICER, were used to collect data in conjunction with ground measurements of leaf area index. The second derivatives of the AVIS spectral reflectance curves, radius of curvature, distance ratios, and NDVIs were calculated and compared to Various ground LAI and canopy closure measures. All relationships between AVIS spectral reflectance curve surrogates and ground LAI measures on 30 forested stands were random. SLICER estimates of average canopy height, median height. canopy-ground power return ratios, canopy power return, and other transformations of the laser data were used to model ground-measured LAI and crown closure. Statistically significant relationships were found between four laser variables and LAI and crown closure. However R-2 value were low, 0.17 - 0.38. These linear and implicitly linear models were of little practical utility for prediction of LAI on the 24 stands considered. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Nelson, R (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. RI Harding, David/F-5913-2012 NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1562 EP 1564 DI 10.1109/IGARSS.1998.691601 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100505 ER PT B AU Wolfe, RE Roy, DP AF Wolfe, RE Roy, DP BE Stein, TI TI The MODIS land data storage methodology: Level 2 grid SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The methodology used to store a number of the Moderate Resolution Imaging Spectroradiometer (MODIS) land products is described. The approach has several advantages over conventional approaches used to store remotely sensed data sets and may be applied to any remote sensing data set where the observations are geolocated to sub-pixel accuracy. The methodology will enable new algorithms to be more accurately developed because important information about the intersection between the sensor observations and the output grid cells are preserved. The methodology will satisfy the needs of the MODIS land product generation algorithms; will allow sophisticated users to develop their own application specific MODIS land data sets; and will enable efficient processing and reprocessing of MODIS land products. C1 NASA, Goddard Space Flight Ctr, Raytheon STX, Greenbelt, MD 20771 USA. RP Wolfe, RE (reprint author), NASA, Goddard Space Flight Ctr, Raytheon STX, Code 922, Greenbelt, MD 20771 USA. RI Wolfe, Robert/E-1485-2012 OI Wolfe, Robert/0000-0002-0915-1855 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1585 EP 1589 DI 10.1109/IGARSS.1998.691629 PG 5 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100512 ER PT B AU Skofronick-Jackson, GM Gasiewski, AJ AF Skofronick-Jackson, GM Gasiewski, AJ BE Stein, TI TI A nonlinear multispectral statistical CLEAN-based precipitation parameter retrieval algorithm SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 Univ Space Res Assoc, Goddard Visiting Scientist Program, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Skofronick-Jackson, GM (reprint author), Univ Space Res Assoc, Goddard Visiting Scientist Program, Goddard Space Flight Ctr, Code 975, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1674 EP 1676 DI 10.1109/IGARSS.1998.692414 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100541 ER PT B AU Racette, P Triesky, M Jones, D AF Racette, P Triesky, M Jones, D BE Stein, TI TI A multi-channel microwave radiometer uses reference averaging for calibration: Precision approaches that of a total power radiometer SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB A seven channel microwave radiometer has recently been developed for the Department of Energy Atmospheric Radiation Measurement Unmanned Aerospace Vehicle program. The instrument is designed to measure precipitable water vapor and cloud liquid water from board a DHC-6 (Twin Otter), chase plane for a remotely piloted vehicle. Five of the seven channels are centered about the 22.235 GHz water vapor absorption line. The other two channels are centered about 36.5 GHz and 89.0 GHz. Four calibration references exist for each channel within the radiometer. A digital computer is used to synchronize the switching of the circulators to the sampling of the analog-to-digital converters, thus, the timing of the data acquisition is programmable. By shortening the duty cycle of the calibration sequence and averaging the reference samples over an extended period of time radiometric precision approaching that of a total power radiometer is achieved. The channel selection along with its novel calibration scheme make this instrument a unique research tool. C1 NASA, Goddard Space Flight Ctr, Microwave Sensors Branch, Greenbelt, MD 20770 USA. RP Racette, P (reprint author), NASA, Goddard Space Flight Ctr, Microwave Sensors Branch, Code 975, Greenbelt, MD 20770 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1695 EP 1697 DI 10.1109/IGARSS.1998.692432 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100548 ER PT B AU Tilton, JC AF Tilton, JC BE Stein, TI TI Image segmentation by region growing and spectral clustering with a natural convergence criterion SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The image segmentation approach described herein is a new hybrid of region g-rowing and spectral clustering. This approach produces a specified number of hierarchical segmentations at different levels of detail, based upon jumps in a dissimilarity criterion. A recursive implementation of this segmentation approach on a cluster of 66 Pentium Pro PCs is described, and the effectiveness of this segmentation approach on Landsat Multispectral Scanner data is discussed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Tilton, JC (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 935, Greenbelt, MD 20771 USA. NR 0 TC 19 Z9 19 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1766 EP 1768 DI 10.1109/IGARSS.1998.703645 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100571 ER PT B AU Hsu, AY O'Neill, PE Houser, PR Wood, EF Doraiswamy, P AF Hsu, AY O'Neill, PE Houser, PR Wood, EF Doraiswamy, P BE Stein, TI TI Examination of aggregation effects in watershed hydrological modeling using microwave-derived soil moisture data SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch 974, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Hsu, AY (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch 974, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RI Houser, Paul/J-9515-2013; OI Houser, Paul/0000-0002-2991-0441; Wood, Eric/0000-0001-7037-9675 NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1840 EP 1842 DI 10.1109/IGARSS.1998.703669 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100595 ER PT B AU O'Neill, PE Hsu, AY Jackson, TJ Swift, CT AF O'Neill, PE Hsu, AY Jackson, TJ Swift, CT BE Stein, TI TI Ground-based microwave radiometer measurements during the Southern Great Plains '97 experiment SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch 974, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP O'Neill, PE (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch 974, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1843 EP 1845 DI 10.1109/IGARSS.1998.703670 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100596 ER PT B AU Meneghini, R Kozu, T Jones, JA Iguchi, T Okamoto, K AF Meneghini, R Kozu, T Jones, JA Iguchi, T Okamoto, K BE Stein, TI TI Estimates of path attenuation for the TRMM radar SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Meneghini, R (reprint author), NASA, Goddard Space Flight Ctr, Code 975, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1882 EP 1884 DI 10.1109/IGARSS.1998.703683 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100609 ER PT B AU Bolvin, DT Adler, RF Huffman, GJ Nelkin, EJ AF Bolvin, DT Adler, RF Huffman, GJ Nelkin, EJ BE Stein, TI TI A first comparison of global merged precipitation analyses with tropical rainfall measuring mission (TRMM) data SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Bolvin, DT (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 912, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1892 EP 1894 DI 10.1109/IGARSS.1998.703686 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100612 ER PT B AU Chu, AH Kim, YJ van Zyl, J Tung, W O'Leary, E Lou, YL AF Chu, AH Kim, YJ van Zyl, J Tung, W O'Leary, E Lou, YL BE Stein, TI TI The NASA/JPL AIRSAR Integrated Processor SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The NASA/JPL AIRSAR Integrated Processor (AIP) is a multi-frequency polarimetric and interferometric SAR processor designed to produce data useful for better understanding of scattering from different types of Earth terrain. The processor is utilized to automatically generate co-registered multifrequency images from both polarimetric and interferomeric data collection modes. When one frequency interfermetric Digital Elevation Map (DEM) is available, all channel images of three-frequency are projected and terrain-corrected to the DEM. All AIP products are corrected geometrically, polarimetrically, and radiometrically. This paper describes the implementation of the operational AIRSAR Integrated Processor. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chu, AH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 300-243, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1908 EP 1910 DI 10.1109/IGARSS.1998.703691 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100617 ER PT B AU Drinkwater, MR Liu, X Low, D AF Drinkwater, MR Liu, X Low, D BE Stein, TI TI Interannual variability in weddell sea ice from ERS Wind Scatterometer SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB ERS-1/2 SAR and Wind Scatterometer data are analyzed together with SSM/I radiometer data to investigate interannual variability in Weddell Sea ice and summer melt signatures during the period 1992-1997. Simultaneous SAR and Scatterometer images were obtained during a February 1995 cruise of the H.M.S. Endurance and aerial photographs collected for validation of the observations. Accompanying field data are used to illustrate observed variability, and to validate the first ever observation of extensive summer melt pending in the Weddell Sea. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Drinkwater, MR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-323, Pasadena, CA 91109 USA. OI Drinkwater, Mark/0000-0002-9250-3806 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1982 EP 1984 DI 10.1109/IGARSS.1998.703715 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100640 ER PT B AU Spencer, MW Wu, CL Long, DG AF Spencer, MW Wu, CL Long, DG BE Stein, TI TI High resolution surface backscatter measurements with the SeaWinds pencil-beam scatterometer SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB A technique employed to extract higher resolution backscatter measurements from the SeaWinds pencil-beam scatterometer system is described. The unique methodology necessary to achieve very high radiometric accuracy for such measurements is discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Spencer, MW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-319, Pasadena, CA 91109 USA. OI Long, David/0000-0002-1852-3972 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 1991 EP 1993 DI 10.1109/IGARSS.1998.703718 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100643 ER PT B AU Wu, SC Romans, LJ Young, LE AF Wu, SC Romans, LJ Young, LE BE Stein, TI TI A novel GPS-based sensor for ocean altimetry SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB A technique for a novel application of GPS signals to ocean altimetry is described. The entire Earth surface is divided into a triangular grid of points nearly-uniformly spaced. The sea surface heights at the grid points are determined using the GPS signals reflected from the surrounding area. Practical grid size and data sampling rate are determined. An efficient estimation scheme is devised to solve for the thousands of parameters. A simulation analysis shows that global ocean altimetric information can be recovered to better than 10 cm with only 1 day of reflected GPS signals. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wu, SC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 238-600, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2008 EP 2010 DI 10.1109/IGARSS.1998.703723 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100648 ER PT B AU Pak, KS Kim, YJ Callahan, PS Dunbar, RS Hsiao, SV Zhang, AZ AF Pak, KS Kim, YJ Callahan, PS Dunbar, RS Hsiao, SV Zhang, AZ BE Stein, TI TI A multi-pass median filter technique to remove ambiguities in retrieved wind fields from spaceborne scatterometer data SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB An automated median filter-based ambiguity removal algorithm is used because of its simplicity and computational efficiency. The algorithm requires an initial wind field. Consequently the performance of the algorithm depends largely on the accuracy of the initial wind field compared to the true wind field. Usually, an initial wind field consisting of the highest ranked retrieved wind vectors is used. However, we found that this does not result in the best performance. In this paper we present a technique called the multi-pass median filter algorithm. The technique gives superior performance to the conventional median filter algorithm by generating a better initial wind field. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Pak, KS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 300-319, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2023 EP 2025 DI 10.1109/IGARSS.1998.703728 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100653 ER PT B AU Le, CTC Hensley, S Chapin, E AF Le, CTC Hensley, S Chapin, E BE Stein, TI TI Removal of RFI in wideband radars SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The least-mean-square (LMS) adaptive filter is applied to suppress narrow-band radio-frequency interference (RFI) in wideband synthetic aperture radar (SAR) signals. Simulation is used to show the working principles of the adaptive filter and to obtain the optimum filter's parameters. The algorithm is tested with P-band synthetic aperture radar (SAR) data collected by the NASA/JPL airborne SAR (AIRSAR) in different noisy environments. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Le, CTC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-235, Pasadena, CA 91109 USA. NR 0 TC 5 Z9 5 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2032 EP 2034 DI 10.1109/IGARSS.1998.703731 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100656 ER PT B AU Schmidlin, FJ AF Schmidlin, FJ BE Stein, TI TI Upper-atmosphere instrumentation research conducted from NASA GODDARD Space Flight Center - Wallops Island, Virginia USA SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Flight Facil, Wallops Island, VA 23337 USA. RP Schmidlin, FJ (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Flight Facil, Wallops Island, VA 23337 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2148 EP 2150 DI 10.1109/IGARSS.1998.703769 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100694 ER PT B AU Wang, JR AF Wang, JR BE Stein, TI TI Profiling of atmospheric water vapor from the SSM/T-2 radiometric measurements SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Data acquired over a period of January-March 1993 from the Special Sensor Microwave/Temperature-2 (SSM/T-2) over the region of TOGA/COARE (Tropical Ocean Global Atmosphere/Coupled Ocean Atmosphere Response Experiment) mission in the western Pacific Ocean are used to retrieve water vapor profiles under both clear and cloudy conditions. The SSM/T-2 measures millimeter-wave radiation at the frequencies of 91, 150, 183.3+/-1, 183.3+/-3, 183.3+/-7 GHz. Large-area (bounded by 30 degrees S to 30 degrees N latitudes and 120 degrees E to 180 degrees E longitudes) water vapor fields at different altitude layers were derived from the SSM/T-2 measurements. These results showed the capability of SSMT-2 in providing both temporal and spatial variations of layered precipitable water (300-500, 500-700, and 700-1000 mbar). The retrieved layered precipitable water (LPR) was found to compare favorably with that derived from a few rawsonde stations in the area. Total precipitable water (TPW) was also derived from the SSM/T-2 retrieval results and compared with that estimated from the SSM/I (Special Sensor Microwave/Imager) on board the same satellite. Generally, values of the SSM/T-2 retrieved TPW are slightly higher than those derived from the SSM/I. Factors that cause this slight bias are explored and discussed. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Wang, JR (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2175 EP 2177 DI 10.1109/IGARSS.1998.703777 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100702 ER PT B AU Kim, Y van Zyl, J AF Kim, Y van Zyl, J BE Stein, TI TI Single pass polarimetric SAR interferometry SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB During the past ten years, the NASA/JPL AIRSAR system has produced polarimetric and interferometric SAR data. SAR polarimetry is useful for characterizing scattering mechanisms while SAR interferometry yields high resolution topographic maps. For bare surfaces, the interferometric SAR topography represents true ground height. However, the radar height is biased by the volume scattering contribution from tree canopies for vegetated areas. Recently, Cloude and Papathanassiou developed a new radar technique called polarimetric SAR interferometry [1]. This technique can produce a radar topographic map corresponding to a particular scattering mechanism. Zn this way, both true ground height and tree height may be derived. The NASA/JPL AIRSAR will be upgraded to collect the C-band polarimetric SAR interferometric data in May, 1998. In this talk, the hardware modifications required for this upgrade will be presented. Since the data will be collected in the single pass interferometric mode, one can study various combinations of interferometric/polarimetric data without suffering temporal decorrelation. Both theoretical and preliminary test results will be discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kim, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2190 EP 2191 DI 10.1109/IGARSS.1998.703782 PG 2 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100707 ER PT B AU Nghiem, SV Yueh, SH Kwok, R Perovich, DK Gow, AJ Barber, DG Comiso, JC AF Nghiem, SV Yueh, SH Kwok, R Perovich, DK Gow, AJ Barber, DG Comiso, JC BE Stein, TI TI Remote sensing of sea ice surface thermal states under cloud cover SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB It is necessary to know sea ice surface thermal states under cloud cover to evaluate cloud effects in the overall climatic feedback mechanisms in polar regions. The challenge is that traditional methods using radiometers such as AVHRR for surface temperature measurements fail under cloudy conditions. We present a new method combining C-band radar data to study sea ice surface temperature change and visible/infrared radiometer data to identify clouds. From laboratory experiments, we show that C-band radar backscatter is sensitive to sea ice surface thermal states. This relationship is utilized to develop the methodology for the sea ice surface temperature study. We present an example with ERS-1 SAR data, AVHRR data, and field experiment measurements over first-year and multi-year sea ice in the Canadian Arctic Archipelago to illustrate the methodology. In this example, SAR data show an increase in sea ice surface temperature, caused by an excess in the surface heat balance under cloud cover. The method is applicable to Arctic first-year ice. For Antarctic sea ice, this method is particularly appropriate since the Antarctic ice cover consists of vast regions of first-year ice where salinity levels are generally higher than those of Arctic sea ice of similar age and structure. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nghiem, SV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-235, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2219 EP 2221 DI 10.1109/IGARSS.1998.703792 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100717 ER PT B AU Yueh, SH Kwok, R Nghiem, SV West, R AF Yueh, SH Kwok, R Nghiem, SV West, R BE Stein, TI TI Change monitoring of Antarctic sea ice using NSCAT dual-polarized backscatter measurements SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Polar sea ice characteristics and the timing of seasonal transitions are important parameters in the study of polar processes and climate changes. NSCAT Ku-band active microwave observations of the Antarctic sea ice cover are described in this article with emphasis on the monitoring of ice covers through the change of Ku-band backscatter signatures. A simple backscatter and polarization ratio threshold algorithm was used to discriminate sea ice and open water with NSCAT dual-polarized backscatter data. The estimated backscatter of classified sea ice pixels is illustrated. The new first year (FY) and pancake sea ice have a backscatter level similar to those of corresponding ice types in the Arctic, although the ice growth mechanisms are quite different. The significant changes of ice backscatter in the Weddell Sea correlates well the timing of fall freeze-up. This should provide a useful large-scale estimate of the dates of freeze-up. A more extensive validation of the potential of this dataset is definitely suggested. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yueh, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-235, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2228 EP 2230 DI 10.1109/IGARSS.1998.703795 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100720 ER PT B AU Joughin, I Fahnestock, M Thomas, B Kwok, R AF Joughin, I Fahnestock, M Thomas, B Kwok, R BE Stein, TI TI Ice flow in northeast Greenland derived using balance velocities as control SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Satellite radar interferometry provides an important new means for measuring ice motion. To make absolute velocity measurements, ground-control points typically are required to refine interferometric baseline estimates. The vast scale and remote location of the ice sheets make it difficult to obtain in situ ground-control data. Balance velocities derived from satellite altimetry digital-elevation models (DEMs) provide an alternate, though less accurate, source of control data. We demonstrate a case in which we are able to achieve an accuracy of just over 3 m/yr using this type of control. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Joughin, I (reprint author), CALTECH, Jet Prop Lab, M-S 300-235, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2246 EP 2248 DI 10.1109/IGARSS.1998.703801 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100726 ER PT B AU Drinkwater, MR Long, DG AF Drinkwater, MR Long, DG BE Stein, TI TI Seasat, ERS-1/2 and NSCAT scatterometer observed changes on the large ice sheets SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Satellite-borne wind scatterometers are effective tools for monitoing ice sheets and microwave imaging techniques enable comparison of historic and contemporary scatterometer data in climate change studies. We document scattering characteristics of the Greenland ice sheet using data from the NSCAT, ERS-1/2 and Seasat SASS instruments. C- and Ku-band data enable characterization of frequency-dependent scattering characteristics and regional melting delineation. SASS-NSCAT differences show 18 year changes in dry-snow zone extent and indicate the decadal reponse to changes in the spatial patterns of accumulation and ablation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Drinkwater, MR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-323, Pasadena, CA 91109 USA. OI Long, David/0000-0002-1852-3972; Drinkwater, Mark/0000-0002-9250-3806 NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2252 EP 2254 DI 10.1109/IGARSS.1998.703803 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100728 ER PT B AU Wilson, WJ Yueh, SH Laursen, B Dinardo, SJ Lay, R AF Wilson, WJ Yueh, SH Laursen, B Dinardo, SJ Lay, R BE Stein, TI TI Polarimetric radiometer and scatterometer measurements of hurricane ocean winds SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB In September 1997, aircraft measurements of hurricane ocean surface winds were made over hurricane ERIKA which was located east of Bermuda. The microwave instruments included three polarimetric radiometers at 17, 19 and 37 GHz and a 14 GHz scatterometer. These instruments were mounted on the NASA P-3 aircraft and were flown around several locations near hurricane ERIKA to measure the azimuthal dependence of the polarimetric wind signal versus incidence angle. Estimates of the wind speed and direction were obtained using dropsondes dropped from the aircraft. Measurements of all 4 Stokes parameters of the ocean signal were made. In area where there were high winds of 35 m/s and scattered clouds, there was a clear azimuthal signal in all the radiometric Stokes parameters, and in the scatterometer signal. Each of these signals was correlated with the wind direction. The radiometric wind signal was similar in all frequencies; however, there was significant variation with the incidence angle. At the larger incidence angles of 55 and 65 degrees, the fourth Stokes parameter, "V" had a peak to peak amplitude of similar to 1 K. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wilson, WJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 168-327, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2301 EP 2303 DI 10.1109/IGARSS.1998.702195 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100743 ER PT B AU Yueh, SH Wilson, WJ West, R AF Yueh, SH Wilson, WJ West, R BE Stein, TI TI Ocean surface wind remote sensing using microwave backscatter and brightness temperatures SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This paper illustrates an improved geophysical model function (GMF) for Ku-band ocean backscatter at high winds and a preliminary geophysical model function for polarimetric brightness temperatures acquired from aircraft measurements. The implications of the geophysical model function for ocean wind velocity measurements are assessed through the analysis of NSCAT data and the simulation of satellite wind radiometer performance. The improved GMF for NSCAT appears to provide a significant better estimate of hurricane force winds than the NSCAT-1 GMF. Performance estimates for passive microwave radiometers suggest comparable accuracies of active and passive techniques from mid through high winds. Active scatterometers appear to offer a better wind direction accuracy at low winds, while passive radiometers provide a better ambiguity selection skill. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yueh, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-235, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2321 EP 2323 DI 10.1109/IGARSS.1998.702201 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100749 ER PT B AU Le Vine, DM Jackson, TJ Swift, CT Isham, J Haken, M Hsu, A AF Le Vine, DM Jackson, TJ Swift, CT Isham, J Haken, M Hsu, A BE Stein, TI TI Passive microwave remote sensing with the synthetic aperture radiometer, ESTAR, during the Southern Great Plains experiment SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Results are presented of measurements made by the synthetic aperture radiometer, ESTAR, during the Southern Great Plains experiment in Oklahoma during the summer, 1997. The objective of the Southern Great Plains experiment (SGP97) was to study passive microwave remote sensing of soil moisture on a spatial and temporal scale representative of future observations from space. To this end, ESTAR new at high altitude (7.6 km) and mapped a swath about 50 km wide (east-to-west) and about 300 km long. The area mapped extended west from Oklahoma City to El Reno and north from the Little Washita River watershed to the Oklahoma-Kansas border. Data was collected almost daily for one month (from June 17 to July 17) and includes several examples of wetting by rainfall followed by a period of drying. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Le Vine, DM (reprint author), NASA, Goddard Space Flight Ctr, Code 975, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2606 EP 2608 DI 10.1109/IGARSS.1998.702293 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100841 ER PT B AU Eplee, RE Robinson, WD Schieber, BD McClain, CR Darzi, M AF Eplee, RE Robinson, WD Schieber, BD McClain, CR Darzi, M BE Stein, TI TI Vicarious calibration of SeaWiFS SO IGARSS '98 - 1998 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, PROCEEDINGS VOLS 1-5: SENSING AND MANAGING THE ENVIRONMENT SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT 1998 International Geoscience and Remote Sensing Symposium (IGARSS 98) on Sensing and Managing the Environment CY JUL 06-10, 1998 CL SEATTLE, WA SP IEEE, Geosci & Remote Sensing Soc, Univ Washington, NASA, NOAA, USN, Off Naval Res, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Eplee, RE (reprint author), NASA, Goddard Space Flight Ctr, Code 970-2, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4403-0 J9 INT GEOSCI REMOTE SE PY 1998 BP 2707 EP 2709 DI 10.1109/IGARSS.1998.702325 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL34S UT WOS:000075217100873 ER PT S AU Marlowe, JM Dixon, GD AF Marlowe, JM Dixon, GD GP SOC EXPT MECH INC SOC EXPT MECH INC TI TACT: A set of MSC/PATRAN & MSC/NASTRAN-based modal correlation tools SO IMAC - PROCEEDINGS OF THE 16TH INTERNATIONAL MODAL ANALYSIS CONFERENCE, VOLS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 16th International Modal Analysis Conference (IMAC) - Model Updating and Correlation CY FEB 02-05, 1998 CL SANTA BARBARA, CA SP Soc Exptl Mech AB This paper describes the functionality and demonstrates the utility of the Test Analysis Correlation Tools (TACT), a suite of MSC/PATRAN Command Language (PCL) tools which automate the process of correlating finite element models to modal survey test data. The initial release of TACT provides a basic yet complete set of tools for performing correlation totally inside the PATRAN/NASTRAN environment. Features include a step-by-step menu structure, pre-test accelerometer set evaluation and selection, analysis and test result export/import in Universal File Format, calculation of frequency percent difference and cross-orthogonality correlation results using NASTRAN, creation and manipulation of mode pairs, and five different ways of viewing synchronized animations of analysis and test modal results. For the PATRAN-based analyst, TACT eliminates the repetitive, time-consuming and error-prone steps associated with transferring finite element data to a third-party modal correlation package, which allows the analyst to spend more time on the more challenging task of model updating. The usefulness of this software is presented using a case history, the correlation for a NASA Langley Research Center (LaRC) low aspect ratio research wind tunnel model. To demonstrate the improvements that TACT offers the MSC/PATRAN- and MSC/NASTRAN-based structural analysis community, a comparison of the modal correlation process using TACT within PATRAN versus external third-party modal correlation packages is presented. C1 NASA, Langley Res Ctr, Engn Anal Branch, Hampton, VA 23681 USA. RP Marlowe, JM (reprint author), NASA, Langley Res Ctr, Engn Anal Branch, MS 431, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-59-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3243 BP 19 EP 25 PG 7 WC Engineering, Mechanical; Mechanics; Optics SC Engineering; Mechanics; Optics GA BK40H UT WOS:000072063100004 ER PT S AU Chandler, KO Anderson, JB Coleman, AD Driskill, TC AF Chandler, KO Anderson, JB Coleman, AD Driskill, TC GP SOC EXPT MECH INC SOC EXPT MECH INC TI Modal testing of the international space station resource node SO IMAC - PROCEEDINGS OF THE 16TH INTERNATIONAL MODAL ANALYSIS CONFERENCE, VOLS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 16th International Modal Analysis Conference (IMAC) - Model Updating and Correlation CY FEB 02-05, 1998 CL SANTA BARBARA, CA SP Soc Exptl Mech AB Modal survey testing of the International Space Station Resource Node was conducted by the Dynamics Test Branch of NASA's Marshall Space Flight Center (MSFC) from December 21, 1996 to January 14, 1997. The Node, manufactured by Boeing, consists of an approximately 16'-long aluminum shell with two axial ports and four radial ports. For the test, various internal support structures, built by Boeing and McDonnell Douglas, were installed inside the Node and two Pressurized Mating Adapter (PMA) mass simulators were installed at each end of the Node. The "hybrid" test configuration, which weighed approximately 23,000 pounds, was designed to provide modal data for; model correlation of two Node flight configurations. The test article was installed in a Universal Modal Test Fixture at MSFC and was supported using flexure elements at five trunnion interface locations. The flexures provided a known boundary condition resulting in modes similar to those found in a "fixed" boundary condition. The test article was instrumented with 1251 accelerometers and modal data was acquired using three exciters. Two configurations of the Node were successfully tested resulting in an experimental database for model correlation. For the primary test configuration, 45 modes were identified in the test bandwidth of 0-50 Hz. C1 NASA, George C Marshall Space Flight Ctr, Dynam Test Branch, Huntsville, AL 35812 USA. RP Chandler, KO (reprint author), NASA, George C Marshall Space Flight Ctr, Dynam Test Branch, ED73, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-59-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3243 BP 77 EP 82 PG 6 WC Engineering, Mechanical; Mechanics; Optics SC Engineering; Mechanics; Optics GA BK40H UT WOS:000072063100013 ER PT S AU Pappa, RS AF Pappa, RS GP SOC EXPT MECH INC SOC EXPT MECH INC TI Independent analysis of the space station node modal test data SO IMAC - PROCEEDINGS OF THE 16TH INTERNATIONAL MODAL ANALYSIS CONFERENCE, VOLS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 16th International Modal Analysis Conference (IMAC) - Model Updating and Correlation CY FEB 02-05, 1998 CL SANTA BARBARA, CA SP Soc Exptl Mech AB With complex structures, comparison of independently derived sets of experimental modal parameters is an excellent way to increase confidence in the results. This paper presents modal identification results using the Eigensystem Realization Algorithm (ERA) on frequency response functions from the modal test of the Space Station Resource Node. The Resource Node is the first U.S.-built structure for the International Space Station. The modal test was conducted by the NASA Marshall Space Flight Center (MSFC) in January 1997 for the Boeing Company, who designed and built the Node. The ERA-calculated parameters are compared with independent results obtained by the MSFC test team using commercial software. There was excellent correlation of mode shapes between the two sets of results for the first 21 vibration modes of the structure up to 35 Hz. From 35 to 50 Hz, about 60 percent of 25 additional modes had excellent correlation. Natural frequencies and damping factors of most modes agreed within 0.1 Hz and 0.2 percent, respectively. C1 NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. RP Pappa, RS (reprint author), NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. NR 0 TC 0 Z9 1 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-59-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3243 BP 276 EP 283 PG 8 WC Engineering, Mechanical; Mechanics; Optics SC Engineering; Mechanics; Optics GA BK40H UT WOS:000072063100041 ER PT S AU Freudinger, LC Lind, R Brenner, MJ AF Freudinger, LC Lind, R Brenner, MJ GP SOC EXPT MECH INC SOC EXPT MECH INC TI Correlation filtering of modal dynamics using the Laplace wavelet SO IMAC - PROCEEDINGS OF THE 16TH INTERNATIONAL MODAL ANALYSIS CONFERENCE, VOLS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 16th International Modal Analysis Conference (IMAC) - Model Updating and Correlation CY FEB 02-05, 1998 CL SANTA BARBARA, CA SP Soc Exptl Mech AB Wavelet analysis allows processing of transient response data commonly encountered in vibration health monitoring tasks such as aircraft flutter testing. The Laplace wavelet is formulated as an impulse response of a single mode system to be similar to data features commonly encountered in these health monitoring tasks. A correlation filtering approach is introduced using the Laplace wavelet to decompose a signal into impulse responses of single mode subsystems. Applications using responses from flutter testing of aeroelastic systems demonstrate modal parameters and stability estimates can be estimated by correlation filtering free decay data with a set of Laplace wavelets. C1 NASA, Dryden Flight Res Ctr, Edwards, CA 93523 USA. RP Freudinger, LC (reprint author), NASA, Dryden Flight Res Ctr, Edwards, CA 93523 USA. NR 0 TC 12 Z9 13 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-59-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3243 BP 868 EP 877 PG 10 WC Engineering, Mechanical; Mechanics; Optics SC Engineering; Mechanics; Optics GA BK40H UT WOS:000072063100123 ER PT S AU Levine, M Bruno, R Gutierrez, H AF Levine, M Bruno, R Gutierrez, H GP SOC EXPT MECH INC SOC EXPT MECH INC TI Interferometry program flight experiment #1: Objectives and results. SO IMAC - PROCEEDINGS OF THE 16TH INTERNATIONAL MODAL ANALYSIS CONFERENCE, VOLS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 16th International Modal Analysis Conference (IMAC) - Model Updating and Correlation CY FEB 02-05, 1998 CL SANTA BARBARA, CA SP Soc Exptl Mech AB The Interferometry Program EXperiments (IPEX) I and II are a series of flight experiments designed to characterize microdynamics of structures in space. Of particular interest is potential thermal snapping when space structures undergo rapid thermal variations, such as a sun-to-shade transition. This information is needed to characterize uncontrollable high frequency disturbances in future space interferometry missions. Both experiments are performed on the German DARA/DASA free-flying platform Astro-Spas, which is sortied out of the shuffle with the robot arm and retrieved after a 10-day mission. IPEX-I, performed during the STS-80 mission in December 1996, was a suite of 12 micro-g accelerometers which monitored the on-board dynamics of the Astro-Spas during normal operations and quiescent periods. The paper will report the results of the IPEX-I flight experiment. The paper will also describe the second flight experiment, IPEX-II, which will be performed during the STS-85 mission in August 1997, and will monitor the microdynamic behavior of an AEC-ABLE mast. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Levine, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-59-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3243 BP 1184 EP 1190 PG 7 WC Engineering, Mechanical; Mechanics; Optics SC Engineering; Mechanics; Optics GA BK40H UT WOS:000072063100169 ER PT S AU Cao, TT Zimmerman, DC James, GH AF Cao, TT Zimmerman, DC James, GH GP SOC EXPT MECH INC SOC EXPT MECH INC TI Identification of Ritz vectors from ambient test data SO IMAC - PROCEEDINGS OF THE 16TH INTERNATIONAL MODAL ANALYSIS CONFERENCE, VOLS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 16th International Modal Analysis Conference (IMAC) - Model Updating and Correlation CY FEB 02-05, 1998 CL SANTA BARBARA, CA SP Soc Exptl Mech AB Load dependent Ritz vectors have been demonstrated to offer great potential in the areas of finite element model correlation and structural damage detection. The methodology developed to experimentally extract these vectors required the measurement of the input loads and the output response. In many engineering applications, it is very difficult to measure or estimate the applied loads. In this paper, a technique is proposed to extract Ritz vectors from ambient test data. Several examples are used to demonstrate the applicability and accuracy of the proposed technique. C1 NASA, Lyndon B Johnson Space Ctr, Struct & Dynam Branch, Houston, TX 77058 USA. RP Cao, TT (reprint author), NASA, Lyndon B Johnson Space Ctr, Struct & Dynam Branch, Houston, TX 77058 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-59-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3243 BP 1609 EP 1614 PG 6 WC Engineering, Mechanical; Mechanics; Optics SC Engineering; Mechanics; Optics GA BK40H UT WOS:000072063100233 ER PT S AU Markham, B Kurz, L Seiferth, J Smid, J Volf, P AF Markham, B Kurz, L Seiferth, J Smid, J Volf, P BE Serpico, SB TI Algorithms and analysis tools for the Landsat detectors trending SO IMAGE AND SIGNAL PROCESSING FOR REMOTE SENSING IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Image and Signal Processing for Remote Sensing IV CY SEP 21-23, 1998 CL BARCELONA, SPAIN SP CNR, NASA, EOS, Commiss European Communities, SPIE Int Soc Opt Engn AB The purpose of this study is to improve mathematical modeling of calibration curves produced by the Landsat calibrators. We explain one band and one lamp modeling and then one calibration band and multiple lamps averaging. The algorithm has three parts at the present, namely one dimensional modeling that includes a change-point removal and two or more signals averaging. A demo of the algorithm and the data is available from the Internet using any Web browser. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20770 USA. RP Markham, B (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20770 USA. RI Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 7 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2959-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3500 BP 25 EP 31 DI 10.1117/12.331871 PG 5 WC Engineering, Aerospace; Computer Science, Artificial Intelligence; Remote Sensing; Optics SC Engineering; Computer Science; Remote Sensing; Optics GA BM38A UT WOS:000078535100003 ER PT S AU Campbell, JW Taylor, CR Smalley, LL Dickerson, T AF Campbell, JW Taylor, CR Smalley, LL Dickerson, T BE Johnson, CB Maclay, TD Allahdadi, FA TI Orbital debris removal and meteoroid deflection SO IMAGE INTENSIFIERS AND APPLICATIONS; AND CHARACTERISTICS AND CONSEQUENCES OF SPACE DEBRIS AND NEAR-EARTH OBJECTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Image Intensifiers and Applications; and Characteristics and Consequences of Space Debris and Near-Earth Objects CY JUL 23, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn AB Orbital debris in low-Earth orbit in the size range from 1 to 10 cm in diameter can be detected but not tracked reliably enough to be avoided by spacecraft. It can cause catastrophic damage even to a shielded spacecraft. With adaptive optics, a ground-based pulsed laser ablating the debris surface can produce enough propulsion in several hundred pulses to cause such debris to reenter the atmosphere. A single laser station could remove: all of the 1-10 cm debris in three years or less. A technology demonstration of laser space propulsion is proposed which would pave the way for the implementation of such a debris removal system. The cost of the proposed demonstration is comparable with the estimated annual cost of spacecraft operations in the present orbital debris environment. Orbital debris is not the only space junk that is deleterious to the Earth's environment. Collisions with asteroids have caused major havoc to the Earth's biosphere many times in the ancient past. Since the possibility still exists for major impacts of asteroids with the Earth, it shown that it is possible to scale up the systems to prevent these catastrophic collisions providing sufficient early warning is available from new generation space telescopes plus deep space radar tracking. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Campbell, JW (reprint author), NASA, George C Marshall Space Flight Ctr, PS01,MSFC, Huntsville, AL 35812 USA. NR 4 TC 0 Z9 0 U1 1 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2889-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3434 BP 101 EP 112 DI 10.1117/12.331226 PG 12 WC Engineering, Aerospace; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA BM32N UT WOS:000078391600011 ER PT S AU Mouroulis, P Thomas, DA AF Mouroulis, P Thomas, DA BE Descour, MR Shen, SS TI Compact, low-distortion imaging spectrometer for remote sensing SO IMAGING SPECTROMETRY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Spectrometry IV CY JUL 20-21, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn DE imaging spectrometry; hyperspectral imaging; optical design; distortion; calibration AB We describe a pushbroom imaging spectrometer having a number of attractive features for remote sensing applications, including compact and simple form, good image quality, high efficiency, and very low levels of distortion. These properties are made possible by the unique characteristics of convex gratings manufactured by electron-beam lithography. A laboratory prototype has been built and is under evaluation. It has an f-number of 2.8, covers a spectral band from 400 to 1000 nm with 3 nm spectral resolution and has 750 spatial elements across the entrance slit. Experimental results are shown that demonstrate very low distortion, on the level of 2% of a pixel. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mouroulis, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 15 Z9 15 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2893-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3438 BP 31 EP 37 DI 10.1117/12.328120 PG 7 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BL91T UT WOS:000077137900004 ER PT S AU Wlezien, RW Horner, GC McGowan, AR Padula, SL Scott, MA Silcox, RJ Simpson, JO AF Wlezien, RW Horner, GC McGowan, AR Padula, SL Scott, MA Silcox, RJ Simpson, JO BE Sater, JM TI The Aircraft Morphing program SO INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES - SMART STRUCTURES AND MATERIALS 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Materials 1998 - Industrial and Commercial Applications of Smart Structures Technologies CY MAR 03-05, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, BF Goodrich Aerosp, USAF Res Lab, Def Adv Res Projects Agcy, Ceram Soc Japan, Intelligent Mat Forum, Japan, USA Res Off DE active structures; aeroelasticity; active flow control; embedded components; smart materials; control effectors; multidisciplinary teams; multidisciplinary design optimization AB In the last decade smart technologies have become enablers that cut across traditional boundaries in materials science and engineering. Here we define smart to mean embedded actuation, sensing, and control logic in a tightly coupled feedback loop. While multiple successes have been achieved in the laboratory, we have yet to see the general applicability of smart devices to real aircraft systems. The NASA Aircraft Morphing program is an attempt to couple research across a wide range of disciplines to integrate smart technologies into high payoff aircraft applications. The program bridges research in seven individual disciplines and combines the effort into activities in three primary program thrusts. System studies are used to assess the highest-payoff program objectives, and specific research activities are defined to address the technologies required for development of smart aircraft systems. In this paper we address the overall program goals and programmatic structure, and discuss the challenges associated with bringing the technologies to fruition. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Wlezien, RW (reprint author), NASA, Langley Res Ctr, MS493, Hampton, VA 23681 USA. NR 0 TC 16 Z9 16 U1 1 U2 7 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2770-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3326 BP 176 EP 187 DI 10.1117/12.310633 PG 12 WC Engineering, Aerospace; Engineering, Mechanical; Optics; Transportation SC Engineering; Optics; Transportation GA BL31K UT WOS:000075067700017 ER PT S AU McGowan, AMR Wilkie, WK Moses, RW Lake, RC Florance, JP Wieseman, CD Reaves, MC Taleghani, BK Mirick, PH Wilbur, ML AF McGowan, AMR Wilkie, WK Moses, RW Lake, RC Florance, JP Wieseman, CD Reaves, MC Taleghani, BK Mirick, PH Wilbur, ML BE Sater, JM TI Aeroservoelastic and structural dynamics research on smart structures conducted at NASA Langley Research Center SO INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES - SMART STRUCTURES AND MATERIALS 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Materials 1998 - Industrial and Commercial Applications of Smart Structures Technologies CY MAR 03-05, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, BF Goodrich Aerosp, USAF Res Lab, Def Adv Res Projects Agcy, Ceram Soc Japan, Intelligent Mat Forum, Japan, USA Res Off DE aeroelasticity; smart structures; piezoelectric actuators; active fiber composites; rotorcraft; buffet load alleviation; individual blade control; aeroservoelasticity; shape memory alloys; damping augmentation; piezoelectric power consumption AB An overview of smart structures research currently underway at the NASA Langley Research Center in the areas of aeroservoelasticity and structural dynamics is presented. Analytical and experimental results, plans, potential technology pay-offs, and challenges are discussed. The goal of this research is to develop the enabling technologies to actively and passively control aircraft and rotorcraft vibration and loads using smart devices. These enabling technologies and related research efforts include developing experimentally-validated finite element and aeroservoelastic modeling techniques; conducting bench experimental tests to assess feasibility and understand system trade-offs; and conducting large-scale wind-tunnel tests to demonstrate system performance. The key aeroservoelastic applications of this research include: active twist control of rotor blades using interdigitated electrode piezoelectric composites and active control of flutter, and gust and buffeting responses using discrete piezoelectric patches. In addition, NASA Langley is an active participant in the DARPA/ Air Force Research Laboratory/ NASA/ Northrop Grumman Smart Wing program which is assessing aerodynamic performance benefits using smart materials. C1 NASA, Langley Res Ctr, Aeroelastic Branch, Hampton, VA 23665 USA. RP McGowan, AMR (reprint author), NASA, Langley Res Ctr, Aeroelastic Branch, Hampton, VA 23665 USA. NR 0 TC 13 Z9 13 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2770-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3326 BP 188 EP 201 DI 10.1117/12.310634 PG 14 WC Engineering, Aerospace; Engineering, Mechanical; Optics; Transportation SC Engineering; Optics; Transportation GA BL31K UT WOS:000075067700018 ER PT S AU Pack, LG Joslin, RD AF Pack, LG Joslin, RD BE Sater, JM TI Overview of Active Flow Control at NASA Langley Research Center SO INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES - SMART STRUCTURES AND MATERIALS 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Materials 1998 - Industrial and Commercial Applications of Smart Structures Technologies CY MAR 03-05, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, BF Goodrich Aerosp, USAF Res Lab, Def Adv Res Projects Agcy, Ceram Soc Japan, Intelligent Mat Forum, Japan, USA Res Off DE active flow control; separation control; MEMS; review AB The paper summarizes Active Flow Control projects currently underway at the NASA Langley Research Center. Technology development is being pursued within a multidisciplinary, cooperative approach, involving the classical disciplines of fluid mechanics, structural mechanics, material science, acoustics, and stability and control theory. Complementing the companion papers in this session, the present paper will focus on projects that have the goal of extending the state-of-the-art in the measurement, prediction, and control of unsteady, nonlinear aerodynamics. Toward this goal, innovative actuators, micro and macro sensors, and control strategies are considered for high payoff flow control applications. The target payoffs are outlined within each section below. Validation of the approaches range from bench-top experiments to wind-tunnel experiments to flight tests. Obtaining correlations for future actuator and sensor designs are implicit in the discussion. The products of the demonstration projects and design tool development from the fundamental NASA R&D level technology will then be transferred to the Applied Research components within NASA, DOD, and US Industry. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Pack, LG (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 0 TC 2 Z9 2 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2770-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3326 BP 202 EP 213 DI 10.1117/12.310635 PG 12 WC Engineering, Aerospace; Engineering, Mechanical; Optics; Transportation SC Engineering; Optics; Transportation GA BL31K UT WOS:000075067700019 ER PT S AU Gilbert, MG Horner, GC AF Gilbert, MG Horner, GC BE Sater, JM TI Actuator concepts and mechatronics SO INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES - SMART STRUCTURES AND MATERIALS 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Materials 1998 - Industrial and Commercial Applications of Smart Structures Technologies CY MAR 03-05, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, BF Goodrich Aerosp, USAF Res Lab, Def Adv Res Projects Agcy, Ceram Soc Japan, Intelligent Mat Forum, Japan, USA Res Off DE mechatronics; piezoelectric; flow control; synthetic jet; vorticity; actuator; THUNDER; smart materials; smart structures AB Mechatronic design implies the consideration of integrated mechanical, electrical, and local control characteristics in electromechanical device design. In this paper, mechatronic development of actuation device concepts for active aircraft aerodynamic flow control are presented and discussed. The devices are intended to be embedded in aircraft aerodynamic surfaces to provide zero-net- momentum jets or additional flow-vorticity to control boundary layers and flow-separation. Two synthetic jet device prototypes and one vorticity-on-demand prototype currently in development are described in the paper. The aspects of actuation materials, design approaches to generating jets and vorticity, and the integration of miniaturized electronics are stressed. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Gilbert, MG (reprint author), NASA, Langley Res Ctr, MS 230, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2770-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3326 BP 214 EP 222 DI 10.1117/12.310636 PG 9 WC Engineering, Aerospace; Engineering, Mechanical; Optics; Transportation SC Engineering; Optics; Transportation GA BL31K UT WOS:000075067700020 ER PT S AU Scott, MA Montgomery, RC Weston, RP AF Scott, MA Montgomery, RC Weston, RP BE Sater, JM TI Subsonic maneuvering effectiveness of high performance aircraft which employ quasi-static shape change devices SO INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES - SMART STRUCTURES AND MATERIALS 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Materials 1998 - Industrial and Commercial Applications of Smart Structures Technologies CY MAR 03-05, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, BF Goodrich Aerosp, USAF Res Lab, Def Adv Res Projects Agcy, Ceram Soc Japan, Intelligent Mat Forum, Japan, USA Res Off DE SMA; pulsed jets; steady jets; smart structures; aircraft flight control; panel code; innovative control effectors; quasi-static shape change; control effectiveness; LMTAS-ICE; CFD AB This paper represents an initial study on the use of quasi-static shape change devices in aircraft maneuvering. The macroscopic effects and requirements for these devices in flight control are the focus of this study. Groups of devices are postulated to replace the conventional leading-edge flap (LEF) and the all-moving wing tip (AMT) on the tailless LMTAS-ICE (Lockheed Martin Tactical Aircraft Systems - Innovative Control Effecters) configuration. The maximum quasi-static shape changes are 13.8% and 7.7% of the wing section thickness for the LEF and AMT replacement devices, respectively. A Computational Fluid Dynamics (CFD) panel code is used to determine the control effectiveness of groups of these devices. A preliminary design of a wings-leveler autopilot is presented. Initial evaluation at 0.6 Mach at 15,000 ft, altitude is made through batch simulation. Results show small disturbance stability is achieved, however, an increase in surface deflection is needed to offset five degrees of sideslip. This only applies to the specific device groups studied, encouraging future research on optimal device placement. C1 NASA, Langley Res Ctr, Dynam & Control Branch, Hampton, VA 23681 USA. RP Scott, MA (reprint author), NASA, Langley Res Ctr, Dynam & Control Branch, MS 132, Hampton, VA 23681 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2770-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3326 BP 223 EP 233 DI 10.1117/12.310637 PG 11 WC Engineering, Aerospace; Engineering, Mechanical; Optics; Transportation SC Engineering; Optics; Transportation GA BL31K UT WOS:000075067700021 ER PT S AU Belvin, K Horner, G Hardy, R Armstrong, D Rosenbaum, D AF Belvin, K Horner, G Hardy, R Armstrong, D Rosenbaum, D BE Sater, JM TI Integration issues for high-strain actuation applications SO INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES - SMART STRUCTURES AND MATERIALS 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Materials 1998 - Industrial and Commercial Applications of Smart Structures Technologies CY MAR 03-05, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, BF Goodrich Aerosp, USAF Res Lab, Def Adv Res Projects Agcy, Ceram Soc Japan, Intelligent Mat Forum, Japan, USA Res Off DE active structures; strain actuation; embedded components AB Strain actuators, used to induce a relative structural displacement, are most effective when integrally embedded into the host structure. The paper summarizes progress and challenges in the field of embedding smart materials into structures. The difficulties of embedding active elements within composite structures are described from a system design perspective. Issues associated with the application of strain actuators in primary aircraft structure are discussed. Development of new embedding technology to combat the difficulties associated with high strain applications is advocated. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Belvin, K (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2770-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3326 BP 234 EP 239 PG 6 WC Engineering, Aerospace; Engineering, Mechanical; Optics; Transportation SC Engineering; Optics; Transportation GA BL31K UT WOS:000075067700022 ER PT S AU Simpson, JO Wise, SA Bryant, RG Cano, RJ Gates, TS Hinkley, JA Rogowski, RS Whitley, KS AF Simpson, JO Wise, SA Bryant, RG Cano, RJ Gates, TS Hinkley, JA Rogowski, RS Whitley, KS BE Sater, JM TI Innovative materials for Aircraft Morphing SO INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES - SMART STRUCTURES AND MATERIALS 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Materials 1998 - Industrial and Commercial Applications of Smart Structures Technologies CY MAR 03-05, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, BF Goodrich Aerosp, USAF Res Lab, Def Adv Res Projects Agcy, Ceram Soc Japan, Intelligent Mat Forum, Japan, USA Res Off DE computational materials; piezoelectrics; ceramics; polymers; fiber optics; composite fabrication; sensors; actuators AB Reported herein is an overview of the research being conducted within the Materials Division at NASA Langley Research Center on the development of smart material technologies for advanced airframe systems. The research is a part of the Aircraft Morphing Program which is a new six-year research program to develop smart components for self-adaptive airframe systems. The fundamental areas of materials research within the program are computational materials; advanced piezoelectric materials; advanced fiber optic sensing techniques; and fabrication of integrated composite structures. This paper presents a portion of the ongoing research in each of these areas of materials research. C1 NASA, Langley Res Ctr, Div Mat, Hampton, VA 23681 USA. RP Simpson, JO (reprint author), NASA, Langley Res Ctr, Div Mat, Hampton, VA 23681 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2770-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3326 BP 240 EP 249 PG 10 WC Engineering, Aerospace; Engineering, Mechanical; Optics; Transportation SC Engineering; Optics; Transportation GA BL31K UT WOS:000075067700023 ER PT S AU Thakoor, S Kennedy, B AF Thakoor, S Kennedy, B BE Sater, JM TI Biomorphic systems based on smart actuators SO INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES - SMART STRUCTURES AND MATERIALS 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Materials 1998 - Industrial and Commercial Applications of Smart Structures Technologies CY MAR 03-05, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, BF Goodrich Aerosp, USAF Res Lab, Def Adv Res Projects Agcy, Ceram Soc Japan, Intelligent Mat Forum, Japan, USA Res Off AB A comparative review of actuation technologies is presented. Innovative mechanism ideas that combine high force and deflection are described. Flexible smart actuators are obtained utilizing real time adaptive biomorphic controls. Such flexible smart actuators constitute an enabling technology for a variety of biomorphic systems ranging from small, agile biomorphic explorers that emulate biological mobility to much larger humanoid or anthropomorphic system. Due to their potential ability to explore difficult, hard-to-reach terrain, biomorphic explorers are promising for a variety of applications in law enforcement, hazardous environment inspection, toxic waste avoidance/elimination, and search/rescue in disaster areas such as earthquake sites. The control mechanisms used for the actuators are based on biological principles. For example, a neurally inspired controller (with the Banked Stimulus-Response, BSR, control generated using a genetic algorithm) provides a mapping between the current state of the robot (measured by sense variables such as internal actuator angles, velocity, and internal periodic clocks) and a target internal configuration (configuration of internal actuator angles). Innovative foldable advanced mobility mechanisms in combination with multipod techniques inspired by peristalsis in an earthworm robot are described. Flexible actuators offer the versatility of both shape control as well as mobility attribute control. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Thakoor, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 301-490, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2770-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3326 BP 308 EP 322 DI 10.1117/12.310645 PG 15 WC Engineering, Aerospace; Engineering, Mechanical; Optics; Transportation SC Engineering; Optics; Transportation GA BL31K UT WOS:000075067700029 ER PT S AU Sengupta, DK Gunapala, SD Bandara, SV Pool, F Liu, JK McKelvey, M Luong, E Torezan, J Mumulo, J Hong, W Gill, J Stillman, GE Curtis, AP Kim, S Chou, LJ Mares, PJ Feng, M Hseih, KC Chuang, SL Bishop, SG Chang, YC Liu, HC Wang, WI AF Sengupta, DK Gunapala, SD Bandara, SV Pool, F Liu, JK McKelvey, M Luong, E Torezan, J Mumulo, J Hong, W Gill, J Stillman, GE Curtis, AP Kim, S Chou, LJ Mares, PJ Feng, M Hseih, KC Chuang, SL Bishop, SG Chang, YC Liu, HC Wang, WI BE McDaniel, DL Manasreh, MO Miles, RH Sivananthan, S TI Monolithically integrated dual-band quantum well infrared photodetector SO INFRARED APPLICATIONS OF SEMICONDUCTORS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium F on Infrared Applications of Semiconductors II, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, USAF Off Sci Res, USAF Res Lab, Semiconductor Laser Branch, USAF Res Lab, Space Sensing & Vehicle Control Branch AB A monolithic quantum well infrared photodetector (QWIP) structure has been presented that is suitable for dual bands in the two atmospheric transmission windows of 3 - 5.3 mu m and 7.5 - 14 mu m, respectively. The proposed structure employs dual stacked, strain InGaAs/AlGaAs and lattice-matched GaAs/AlGaAs quantum well infrared photodetector for mid wavelength and long wavelength detection. The response peak of the strain InGaAs/AlGaAs quantum well is at 4.9 mu m and the lattice-matched GaAs/AlGaAs is at 10.5 mu m; their peak sensitivities are in the spectral regions of 3 - 5.3 mu m and 7.5 - 14 mu m. The peak responsivity when the dual-band QWIP is biased at 5 Volts is similar to 0.065A/W at 4.9 mu m and similar to 0.006A/W at 10.5 mu m; at this voltage the dual-band QWIP is more sensitive at the shorter wavelengths due to its larger impedance thus exhibiting wavelength tunability characteristics with bias. Additionally, single colored 4.9 and 10.5 mu m QWIPs were fabricated from the dual-band QWIP structure to study the bias-dependent behavior and also to understand the effects of growing the strain layer InGaAs/AlGaAs QWIP on top of the lattice-matched GaAs/AlGaAs QWIP. In summary, two stack dual-band QWIPs using GaAs/AlGaAs and strained InGaAs/AlGaAs multiquantum wells have been demonstrated with peak spectral sensitivities in the spectral region of 3 - 5.3 mu m and 7.5 - 14 mu m. Also, the voltage tunable dual-band detection have been realized for this kind of QWIP structure. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Sengupta, DK (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-389-4 J9 MATER RES SOC SYMP P PY 1998 VL 484 BP 205 EP 214 PG 10 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Engineering; Materials Science GA BK98L UT WOS:000073983400028 ER PT S AU Stahle, CM Shi, ZQ Hu, K Barthelmy, SD Snodgrass, SJ Lehtonen, SJ Mach, KJ Barbier, L Gehrels, N Krizmanic, JF Palmer, D Parsons, AM Shu, P AF Stahle, CM Shi, ZQ Hu, K Barthelmy, SD Snodgrass, SJ Lehtonen, SJ Mach, KJ Barbier, L Gehrels, N Krizmanic, JF Palmer, D Parsons, AM Shu, P BE McDaniel, DL Manasreh, MO Miles, RH Sivananthan, S TI Fabrication of CdZnTe strip detectors for large area arrays SO INFRARED APPLICATIONS OF SEMICONDUCTORS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium F on Infrared Applications of Semiconductors II, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, USAF Off Sci Res, USAF Res Lab, Semiconductor Laser Branch, USAF Res Lab, Space Sensing & Vehicle Control Branch AB A CdZnTe strip detector large area array (similar to 60 cm(2) with 36 detectors) with capabilities for high resolution imaging and spectroscopy has been built as a prototype for a space flight gamma ray burst instrument. The detector array also has applications in nuclear medical imaging. Two dimensional orthogonal strip detectors with 100 mu m pitch have been fabricated and tested. Details for the array design, fabrication and evaluation of the detectors will be presented. C1 NASA, Goddard Space Flight Ctr, Orbital Sci Corp, Greenbelt, MD 20771 USA. RP Stahle, CM (reprint author), NASA, Goddard Space Flight Ctr, Orbital Sci Corp, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012; Barthelmy, Scott/D-2943-2012; Parsons, Ann/I-6604-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-389-4 J9 MATER RES SOC SYMP P PY 1998 VL 484 BP 285 EP 290 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Engineering; Materials Science GA BK98L UT WOS:000073983400038 ER PT S AU Ksendzov, A Cwik, TA Fernandez, S La Baw, CC Maker, PD Muller, RE AF Ksendzov, A Cwik, TA Fernandez, S La Baw, CC Maker, PD Muller, RE BE Fowler, AM TI Wedge filters for spectral imaging in the near IR using metal grids SO INFRARED ASTRONOMICAL INSTRUMENTATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Astronomical Instrumentation CY MAR 23-25, 1998 CL KONA, HI SP Int Soc Opt Engn, European So Observ DE mesh filter; wedge filter; imaging spectrometer; microlithography AB Linear Variable Filters (LVF's or "wedge filters") have found increasing applicability in spectrally selective optical instruments. They serve as moderate resolution spectral discriminators in astronomical instruments and in reconnaissance equipment. They perform extremely well as "sliding out-of-band blocking filters" when used in conjunction with grating spectrometers. Visible band LVF's fabricated using traditional interference filter technology have become available and form the basis of a number of spectral imager and imaging spectrometer designs. The desire to extend the instrumentation into the infrared region has been often stated. Additionally, commercial providers of devices using LVF's desire readily available parts and consistent specification. We have manufactured wedge filters covering the 2.5 - 5 mu m spectral range by patterning thin metal films using the electron beam lithography technique. Arrays of apertures with varying size and pitch were manufactured in a gold layer deposited on a calcium fluoride substrate. This technique can produce large area arrays (up to 1.5 cm x 1.5 cm), offers high reproducibility and allows arbitrary tailoring of the bandpass wavelength versus position profile, unlike dielectric layer interference wedge filters that offer linear grading only. The opportunity to specify a particular wavelength versus position sequence to emphasize certain spectral regions is very attractive to both commercial and government agency users. In manufacturing these filters we have relied on exact electromagnetic analysis that accounts for the grid periodicity, element shape, and material parameters. This analysis allows design of the center wavelength and bandwidth for the given application with the predicted results matching well with the measured response. We will discuss the application to astronomical instrumentation, theory of operation, the manufacturing technique, and its current limitations and possible means of improvement. The most recent theoretical and experimental results will be presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ksendzov, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2801-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3354 BP 159 EP 167 DI 10.1117/12.317258 PN 1-2 PG 9 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL60J UT WOS:000075982700018 ER PT S AU Toomey, DW Ftaclas, C Brown, RH Trilling, D AF Toomey, DW Ftaclas, C Brown, RH Trilling, D BE Fowler, AM TI CoCo: an experiment in infrared coronagraphy at the IRTF SO INFRARED ASTRONOMICAL INSTRUMENTATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Astronomical Instrumentation CY MAR 23-25, 1998 CL KONA, HI SP Int Soc Opt Engn, European So Observ AB Imaging planets, brown dwarfs and disks around nearby stars is a challenging endeavor due to the required scene contrast Success requires imaging down to m=20-25 within arcseconds of stars that are 4th -6th magnitude. Light scattered and diffracted from a variety of sources increases the background nux in the area of interest by orders of magnitude masking the target objects. As first shown by M.B.Lyot in 1939 masks can be placed in the focal plane and pupil planes of a camera to occult the bright central source making it possible to image the faint extensions around it. CoCo is an experiment in using a coronagraphic camera, for infrared observations, on a large telescope in an effort to understand how a coronagraph can help and how to properly design one for the new generation of large telescopes. Recent results with CoCo show a factor of 5-10 reduction in background levels in the area from 2 - 7 arcseconds from the central object. This paper will describe those results and summarize what has been learned towards building coronagraphic cameras for today's large telescopes. C1 Univ Hawaii, Inst Astron, NASA, Infrared Telescope Facil, Honolulu, HI 96822 USA. RP Toomey, DW (reprint author), Univ Hawaii, Inst Astron, NASA, Infrared Telescope Facil, Honolulu, HI 96822 USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2801-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3354 BP 782 EP 790 DI 10.1117/12.317214 PN 1-2 PG 9 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL60J UT WOS:000075982700087 ER PT S AU Erickson, EF AF Erickson, EF BE Fowler, AM TI Science instrument interfaces on SOFIA SO INFRARED ASTRONOMICAL INSTRUMENTATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Astronomical Instrumentation CY MAR 23-25, 1998 CL KONA, HI SP Int Soc Opt Engn, European So Observ DE airborne; infrared; instruments; SOFIA AB SOFIA (the Stratospheric Observatory for Infrared Astronomy) will permit observations not possible from ground based telescopes, while retaining a number of their major advantages for observers. These include the opportunity to change focal plane instruments frequently, and continuous access to the instrument while observing. SOFIA is being designed to maximize the benefits of these features and to assure optimum performance of the instruments, within the constraints of available resources. This paper describes the top level optical, mechanical, and electronic interface parameters and configuration issues forseen for Science Instruments on SOFIA. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Erickson, EF (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2801-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3354 BP 930 EP 939 DI 10.1117/12.317296 PN 1-2 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL60J UT WOS:000075982700103 ER PT S AU Haas, MR Erickson, EF Baltz, JA Colgan, SWJ Lynch, DH McGuire, J Pina, RK Roellig, TL Simpson, JP Telesco, CM Wolf, J Young, ET AF Haas, MR Erickson, EF Baltz, JA Colgan, SWJ Lynch, DH McGuire, J Pina, RK Roellig, TL Simpson, JP Telesco, CM Wolf, J Young, ET BE Fowler, AM TI The preliminary optical design of AIRES: an Airborne Infra-Red Echelle Spectrometer for SOFIA SO INFRARED ASTRONOMICAL INSTRUMENTATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Astronomical Instrumentation CY MAR 23-25, 1998 CL KONA, HI SP Int Soc Opt Engn, European So Observ DE airborne; anamorphic; echelle; infrared; grating; SOFIA; spectrometer AB NASA's Stratospheric Observatory For Infrared Astronomy (SOFIA.) will enable unprecedented infrared acuity at wavelengths obscured from the ground. To help open this new chapter in the exploration of the infrared universe, we are developing the Airborne Infra-Red Echelle Spectrometer (AIRES) as a facility science instrument. Full funding was awarded for a four year development in October, 1997. The instrument is scheduled to come on-line with the observatory in the fall of 2001. It will be used to investigate a broad range of phenomena that occur in the interstellar medium. AIRES will use a 1200 mm long, 76 degrees blaze angle (R4) echelle to combine high resolution spectroscopy (lambda/delta lambda similar to 70000 - 5000) with diffraction-limited imaging in the cross-dispersion direction. Its three two-dimensional detector arrays (Si:Sb Blocked Impurity Band, Ge:Sb photoconductor, and stressed Ge:Ga photoconductor) will provide good sensitivity over a decade in wavelength (17 - 210 mu m). An additional array (Si:As Blocked Impurity Band) will be used as a slit viewer for lambda less than or equal to 28 mu m to image source morphology and to verify telescope pointing. Our scientific motivation, preliminary optical design and packaging, focal plane configuration, echelle prototyping, and cryostat layout are described. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Haas, MR (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. RI Colgan, Sean/M-4742-2014 NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2801-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3354 BP 940 EP 951 DI 10.1117/12.317297 PN 1-2 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL60J UT WOS:000075982700104 ER PT S AU Mentzell, E McIntosh, M Schwenker, J Thompson, R AF Mentzell, E McIntosh, M Schwenker, J Thompson, R BE Fowler, AM TI NICMOS cold-well displacement monitor: a portable Hubble simulator SO INFRARED ASTRONOMICAL INSTRUMENTATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Astronomical Instrumentation CY MAR 23-25, 1998 CL KONA, HI SP Int Soc Opt Engn, European So Observ DE NICMOS; Hubble Space Telescope; infrared camera; instrument testing AB The anomalous motion of the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) detector arrays was originally discovered and characterized during ground optical testing in a large, high fidelity Hubble Space Telescope (HST) simulator. To monitor the state of the cryo-mechanical system, as NICMOS traveled among several testing sites, a portable stimulus was needed. The Cold-well Displacement Monitor (CDM) was quickly assembled from a very simple design. The "cheaper, better, faster" approach proved to be a winner here. Off-the-shelf optics, a simplified interface to the instrument, and a limited set of requirements were used. After calibration against the large Refractive Aberration Simulator/Hubble Opto-Mechanical Simulator (RAS/HOMS), the CDM gave results of similar accuracy to RAS/HOMS. It became the primary tool for the difficult job of managing the NICMOS cryogen system up through launch. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mentzell, E (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2801-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3354 BP 1044 EP 1052 PN 1-2 PG 9 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL60J UT WOS:000075982700114 ER PT S AU Mah, RW Wilson, E Guerrero, MC Galvagni, AE Wallace, MA Winters, JL AF Mah, RW Wilson, E Guerrero, MC Galvagni, AE Wallace, MA Winters, JL BE Fowler, AM TI Development of telescope balancing methodologies for SOFIA SO INFRARED ASTRONOMICAL INSTRUMENTATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Astronomical Instrumentation CY MAR 23-25, 1998 CL KONA, HI SP Int Soc Opt Engn, European So Observ DE SOFIA telescope; KAO telescope; telescope balancing; automated balancing; computer-aided balancing; neural network AB NASA Kuiper telescope personnel identified computer-aided telescope balancing as a needed capability which will save significant amount of time and will improve SOFIA operational effectiveness. Automated telescope balancing is considered a "critical technology need" for SOFIA. It is necessary to balance the telescope to accommodate the different science instruments. The telescope must be adequately balanced to enable the pointing and tracking system to operate properly. Inflight balancing may be necessary because the mass properties of the science instruments can change during its operation (i.e., depletion of cryogenics) and because of disturbance torques. In the past, a trial and error procedure was used to balance the Kuiper telescope, which can take up to several hours and requires a highly skilled, experienced technician to perform the task. Various approaches for balancing the telescope are reported in this paper. Potential benefits are: 1) enable balance compensation to be performed quickly (minutes instead of hours), thereby reducing operations costs, 2) enable a much wider range of balance compensation to be performed in-flight, which may increase science observation time and science return, 3) enable technicians of any skill level to balance the telescope with the aid of a computerized system, and 4) improve the performance of the telescope by increasing the precision of the balance, which may increase science return. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Mah, RW (reprint author), NASA, Ames Res Ctr, MS 269-1, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2801-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3354 BP 1130 EP 1138 DI 10.1117/12.317238 PN 1-2 PG 9 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL60J UT WOS:000075982700124 ER PT S AU Bock, JJ Kawada, M Lange, AE Matsumoto, T Uemizu, K Watabe, T Yost, SA Fazio, GG Forrest, WJ Pipher, JL Price, SD AF Bock, JJ Kawada, M Lange, AE Matsumoto, T Uemizu, K Watabe, T Yost, SA Fazio, GG Forrest, WJ Pipher, JL Price, SD BE Fowler, AM TI Rocket-borne instrument to search for infrared emission from baryonic dark matter in galactic halos SO INFRARED ASTRONOMICAL INSTRUMENTATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Astronomical Instrumentation CY MAR 23-25, 1998 CL KONA, HI SP Int Soc Opt Engn, European So Observ DE infrared astronomy; InSb; galactic halos; baryonic matter AB We describe the design and performance of the Near Infrared Telescope Experiment (NITE), a rocket-borne instrument designed to search for infrared emission from baryonic dark matter in the halos of nearby edge-on spiral galaxies. A 256 x 256 InSb array at the focus of a 16.5 cm liquid-helium-cooled telescope achieves near-background-limited sensitivity in a 3.5 - 5.5 mu m waveband where the local foreground from zodiacal emission is at a minimum. This experiment represents the first scientific application of a low-background infrared InSb array, a precursor to the InSb arrays intended for SIRTF, in a spaceborne observation. We describe the night performance of the instrument and preliminary scientific results from an observation of NGC 4565. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Bock, JJ (reprint author), Jet Prop Lab, Pasadena, CA 91109 USA. NR 0 TC 4 Z9 4 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2801-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3354 BP 1139 EP 1149 DI 10.1117/12.317239 PN 1-2 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL60J UT WOS:000075982700125 ER PT S AU Roellig, TL Houck, JR Van Cleve, J Rakowski, A Stewart, C Taudien, G Huisjen, M Bolton, M Seib, D AF Roellig, TL Houck, JR Van Cleve, J Rakowski, A Stewart, C Taudien, G Huisjen, M Bolton, M Seib, D BE Fowler, AM TI Infrared spectrograph for the space infrared telescope facility (SIRTF) SO INFRARED ASTRONOMICAL INSTRUMENTATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Astronomical Instrumentation CY MAR 23-25, 1998 CL KONA, HI SP Int Soc Opt Engn, European So Observ DE infrared astronomy; spectroscopy; infrared instrumentation AB The Infrared Spectrograph (IRS) will provide the Space Infrared Telescope Facility (SIRTF) with low and moderate-spectral resolution spectroscopic capabilities from 4 to 40 microns. The IRS is composed of four separate modules, with two of the modules providing R similar to 50 spectral resolution over 4 to 40 microns and two modules providing R similar to 600 spectral resolution over 10 to 37 microns. Each module has its own entrance slit in the focal plane and the IRS instrument has no moving parts. The low-resolution modules employ long slit designs that allow both spectral and one-dimensional spatial information to be acquired simultaneously on the same detector array. Two small imaging sub-arrays in one of the low-resolution modules will also allow infrared objects with poorly known positions to be accurately placed into any of the IRS modules' entrance slits. The high-resolution modules use a cross-dispersed echelle design that gives both spectral and limited spatial measurements on the same detector array. The one-sigma continuum sensitivity requirements for the IRS low-resolution modules are 0.11 mJy from 6 to 15 microns and 0.30 mJy from 15 to 40 microns in 500 seconds of integration. The high-resolution modules' one-sigma line sensitivity requirements are 6.0 x 10(-23) W-c(m-2) in the same integration time. Internal calibration sources allow the IRS to perform self monitoring of detector sensitivity changes. Careful thermal design allows all four modules to be powered up simultaneously and still input less than 4 mW total power into the SIRTF liquid helium bath. The optical, mechanical, thermal, and electrical design of the IRS is discussed, as is the IRS on-orbit operational concept. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Roellig, TL (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. NR 0 TC 21 Z9 21 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2801-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3354 BP 1192 EP 1203 DI 10.1117/12.317248 PN 1-2 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL60J UT WOS:000075982700132 ER PT S AU Spinhirne, JD Scott, VS Cavanaugh, J Palm, S Manizade, K Hoffman, JW Grush, RC AF Spinhirne, JD Scott, VS Cavanaugh, J Palm, S Manizade, K Hoffman, JW Grush, RC BE Dereniak, EL Sampson, RE TI Preliminary spaceflight results from the uncooled infrared spectral imaging radiometer (ISIR) on shuttle mission STS-85 SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Detectors and Focal Plane Arrays V CY APR 14-17, 1998 CL ORLANDO, FL SP SPIE DE radiometer; multispectral; imaging; infrared; uncooled; pushbroom; microbolometer; blackbody AB In August 1997 an infrared spectral imaging radiometer (ISIR) based on uncooled microbolometer array technology was flown on space shuttle mission STS-85. In this paper the design of the instrument and experimental goals are presented, and initial results from the flight mission are described. The ISIR instrument provided 1/4 km resolution imagery at four wavelengths that were selected for cloud remote sensing. A major goal of the work is development of compact and less costly cloud imagers for small satellite missions. A large data set of earth imagery and test operations was obtained from the mission. In most regards the ISIR functioned within its design parameters. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Spinhirne, JD (reprint author), NASA, Goddard Space Flight Ctr, MC912, Greenbelt, MD 20771 USA. RI Scott, Vibart/B-5086-2013 NR 0 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2828-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3379 BP 14 EP 21 DI 10.1117/12.317586 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BL57H UT WOS:000075913800002 ER PT S AU Foote, MC Jones, EW AF Foote, MC Jones, EW BE Dereniak, EL Sampson, RE TI High performance micromachined thermopile linear arrays SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Detectors and Focal Plane Arrays V CY APR 14-17, 1998 CL ORLANDO, FL SP SPIE AB Linear thermopile infrared detector arrays have been produced with D* values as high as 2.2x10(9) cmHz(1/2)/W for 83 ms response times. Typical responsivity is 1000 V/W. This result has been achieved with Bi-Te and Bi-Sb-Te thermoelectric materials on micromachined silicon nitride membranes. Results for several device geometries are described and compared to literature values for Schwartz type thermocouple detectors and for thin film thermopile detectors and arrays. Measurements of responsivity as a function of modulation frequency and wavelength are presented. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Foote, MC (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 0 TC 7 Z9 7 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2828-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3379 BP 192 EP 197 DI 10.1117/12.317587 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BL57H UT WOS:000075913800019 ER PT S AU Gunapala, SD Bandara, SV Singh, A Liu, JK Luong, EM Mumolo, JM McKelvey, MJ AF Gunapala, SD Bandara, SV Singh, A Liu, JK Luong, EM Mumolo, JM McKelvey, MJ BE Dereniak, EL Sampson, RE TI Quantum well infrared photodetectors for low background applications SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Detectors and Focal Plane Arrays V CY APR 14-17, 1998 CL ORLANDO, FL SP SPIE AB High performance long-wavelength GaAs/AlxGa1-xAs quantum well infrared photodetectors for low background applications have been demonstrated. This is the first theoretical analysis of quantum well infrared photodetectors for low background applications and the detectivity D* of 6x10(13) cm root Hz/W has been achieved at T = 40 K with 2 x 10(9) photons/cm(2)/sec background. In addition, this paper describes the demonstration of mid-wavelength/long-wavelength dualband quantum well infrared photodetectors and long-wavelength/very long-wavelength dualband quantum well infrared photodetectors in 4-26 mu m wavelength region. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Gunapala, SD (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 0 TC 20 Z9 20 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2828-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3379 BP 225 EP 234 DI 10.1117/12.317590 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BL57H UT WOS:000075913800022 ER PT S AU Gunapala, SD Bandara, SV Liu, JK Hong, W Luong, EM Mumolo, JM McKelvey, MJ Sengupta, DK Singh, A Shott, CA Carralejo, R Maker, PD Bock, JJ Ressler, ME Werner, MW Krabach, TN AF Gunapala, SD Bandara, SV Liu, JK Hong, W Luong, EM Mumolo, JM McKelvey, MJ Sengupta, DK Singh, A Shott, CA Carralejo, R Maker, PD Bock, JJ Ressler, ME Werner, MW Krabach, TN BE Dereniak, EL Sampson, RE TI Quantum well infrared photodetector research and development at jet propulsion laboratory SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Detectors and Focal Plane Arrays V CY APR 14-17, 1998 CL ORLANDO, FL SP SPIE DE quantum wells; infrared detectors; focal plane arrays; dualband detectors; broadband detectors; applications AB One of the simplest device realizations of the classic particle-in-the-box problem of basic quantum mechanics is the Quantum Well Infrared Photodetector (QWIP). In this paper we discuss the optimization of the detector design, material growth and processing that has culminated in realization of 15 micron cutoff 128x128 QWIP focal plane array camera, hand-held and palmsize 256x256 long-wavelength QWIP cameras and 648x480 long-wavelength camera, holding forth great promise for myriad applications in 6-25 micron wavelength range in science, medicine, defense and industry. In addition, we present the recent developments in broadband QWIPs, mid-wavelength/long-wavelength dualband QWIPs, long-wavelength/very long-wavelength dualband QWIPs, and high quantum efficiency QWIPs for low background applications in 4-26 mu m wavelength region for NASA and DOD applications. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Gunapala, SD (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 0 TC 21 Z9 21 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2828-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3379 BP 382 EP 395 DI 10.1117/12.317606 PG 14 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BL57H UT WOS:000075913800037 ER PT S AU Bandara, SV Gunapala, SD Liu, JK Luong, EM Mumolo, JM Hong, W Sengupta, DK McKelvey, MJ AF Bandara, SV Gunapala, SD Liu, JK Luong, EM Mumolo, JM Hong, W Sengupta, DK McKelvey, MJ BE Dereniak, EL Sampson, RE TI 10-16 mu m Broad-band quantum well infrared photodetector SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Detectors and Focal Plane Arrays V CY APR 14-17, 1998 CL ORLANDO, FL SP SPIE AB A broad-band infrared detector, sensitive over a 10- 16 mu m spectral range, based on GaAs/AlxGa1-xAs quantum wells grown by molecular beam epitaxy, has been demonstrated. Wavelength broadening of Delta lambda/lambda(p) similar to 42% is observed to be about a 400 % increase compared to a typical bound-to-quasibound quantum well infrared photodetector (QWIP). In this device structure, which is different from typical QWIP device structures, two different gain mechanisms associated with photocurrent electrons and dark current electrons were observed and explained. Even with broader response, D* similar to 1 x 10(10) cm root HZ /W at T = 55 K is comparable to regular QWIPs with similar cutoff wavelengths. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Bandara, SV (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 0 TC 10 Z9 10 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2828-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3379 BP 396 EP 401 DI 10.1117/12.317607 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BL57H UT WOS:000075913800038 ER PT S AU Pool, FS Wilson, DW Maker, PD Muller, RE Gill, JJ Sengupta, DK Liu, JK Bandara, SV Gunapala, SD AF Pool, FS Wilson, DW Maker, PD Muller, RE Gill, JJ Sengupta, DK Liu, JK Bandara, SV Gunapala, SD BE Dereniak, EL Sampson, RE TI Fabrication and performance of diffractive optics for quantum well infrared photodetectors SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Detectors and Focal Plane Arrays V CY APR 14-17, 1998 CL ORLANDO, FL SP SPIE DE diffractive optics; multi-quantum-well; GaAs; PMMA AB Diffractive optical elements (microlenses) for quantum well infrared photodetectors (QWIPs) were fabricated by two techniques: 1) standard lithography of a binary optical structure and 2) PMMA pattern transfer for an analog diffractive optic structure. The binary lenses were fabricated by sequential contact lithography and etching using two binary masks. The analog diffractive lenses were fabricated in PMMA by direct-write e-beam lithography followed by acetone development. The resulting PMMA surface relief profile was transferred into the GaAs by dry etching. Both types of lenses were etching into GaAs using an electron cyclotron resonance (ECR) microwave plasma etching system. Although the lenses were fabricated accurately, the performance of the QWIPs was not improved as much as expected due to the angle-of-incidence sensitivity of the QWIP light-coupling grating. The lenses would have likely improved the performance of detectors capable of absorbing normally incident light. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Pool, FS (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 6 Z9 7 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2828-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3379 BP 402 EP 409 DI 10.1117/12.317608 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BL57H UT WOS:000075913800039 ER PT S AU Sengupta, DK Gunapala, SD George, T Bandara, SV Chang-Chien, CN Leon, R Kayali, S Kuo, HC Fang, W Liu, HC Stillman, GE AF Sengupta, DK Gunapala, SD George, T Bandara, SV Chang-Chien, CN Leon, R Kayali, S Kuo, HC Fang, W Liu, HC Stillman, GE BE Dereniak, EL Sampson, RE TI Comparison of intersubband GaAs/AlGaAs multiple quantum well infrared photodetectors SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Detectors and Focal Plane Arrays V CY APR 14-17, 1998 CL ORLANDO, FL SP SPIE DE quantum well infrared photodetectors; dark current; spectral response; absolute response; GaAs-on-Si substrate AB We have successfully fabricated intersubband GaAs/AlGaAs quantum well infrared photodetectors grown on GaAs-on-Si substrate and evaluated their structural, electrical, and optical characteristics. We have found that the performance is comparable to a similar detector structure grown on a semi-insulating GaAs substrate. The results are promising for applications in the important 8-12 mu m atmospheric window. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sengupta, DK (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 0 TC 3 Z9 3 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2828-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3379 BP 410 EP 422 DI 10.1117/12.317609 PG 13 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BL57H UT WOS:000075913800040 ER PT S AU Yang, G Sun, C Shaw, T Wrigley, C Peddada, P Blazejewski, E Pain, B AF Yang, G Sun, C Shaw, T Wrigley, C Peddada, P Blazejewski, E Pain, B BE Pain, B Lomheim, TS TI A high dynamic-range, low-noise focal plane readout for VLWIR applications implemented with current mode background subtraction SO INFRARED READOUT ELECTRONICS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Readout Electronics IV CY APR 13, 1998 CL ORLANDO, FL SP SPIE DE large dynamic range; high background; QWIP; focal plane arrays; readout electronics; background suppression; signal handling capacity; current memory; buffered direct injection AB Design and operation of a low noise CMOS focal plane readout circuit with ultra-high charge handling capacity is presented. Designed for high-background, VLWLR detector readout, each readout unit cell uses an accurate dynamic current memory for automatic subtraction of the dark pedestal in current domain enabling measurement of small signals 85 dB below the dark level. The readout circuit operates with low-power dissipation, high linearity, and is capable of handling pedestal currents up to 300 nA. Measurements indicate an effective charge handling capacity of over 5x10(9) charges/pixel with less than 10(5) electrons of input referred noise. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yang, G (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 14 Z9 15 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2809-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3360 BP 42 EP 51 DI 10.1117/12.321761 PG 10 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85J UT WOS:000076932500004 ER PT S AU Cunningham, TJ Fitzsimmons, M AF Cunningham, TJ Fitzsimmons, M BE Pain, B Lomheim, TS TI Recent advances in GaAs JFETs for deep cryogenic focal plane readouts SO INFRARED READOUT ELECTRONICS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Readout Electronics IV CY APR 13, 1998 CL ORLANDO, FL SP SPIE DE GaAs; JFET; multiplexer; cryogenic; low temperature; infrared detectors; readout; noise AB The progress of the kt Propulsion Laboratory in developing gallium arsenide junction field-effect transistors (GaAS JFETs) for application in infrared readout electronics operating below 10 Kelvin is discussed. Results on GaAs JFETs fabricated using a highly isotropic HF-based etchant have been presented previously by our group. The isotropic etch reduced the typical input leakage current at 4 K to less than 1 fA. These JFETs had a low frequency noise of just under 1 mu V/Hz(1/2) at 1 Hz at 4 K, while dissipating less than 1 mu W of power. Building on this work, we have fabricated small-scale integrated circuits based on this GaAs JFET technology. In this paper we report on the fabrication of small-scale integrated circuit multiplexers and amplifiers. An 8x1 source-follower-per-detector multiplexer and a three-transistor differential pair have been fabricated and are fully functional at 4 K. The input-referred noise and leakage current is consistent with that for the discrete devices. A systematic study of the device size dependence of the noise has been started, but as yet is inconclusive. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Cunningham, TJ (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, MS 300-315,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2809-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3360 BP 74 EP 78 DI 10.1117/12.321754 PG 5 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85J UT WOS:000076932500007 ER PT S AU Larar, AM Cook, WB Lancaster, RS AF Larar, AM Cook, WB Lancaster, RS BE Strojnik, M Andresen, BF TI Laboratory prototype double-etalon Fabry-Perot interferometer for remotely sensing atmospheric ozone: Atmospheric measurements SO INFRARED SPACEBORNE REMOTE SENSING VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Spaceborne Remote Sensing VI CY JUL 22-24, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn DE Fabry-Perot interferometry; laboratory prototype; high-resolution spectroscopy; tropospheric ozone; global monitoring AB Space-based observations of tropospheric trace species have been identified as high-priority atmospheric science measurements to be included in Earth science missions of the 21st century. Critical to such measurements are tropospheric ozone (O-3) concentrations, which have been increasing and will continue to do so as levels of the precursor gases (oxides of nitrogen, methane and other hydrocarbons) necessary for the photochemical production of tropospheric O-3 remain rising; such a global monitoring capability is crucial to enhance scientific understanding as well as to potentially lessen the ill-health impacts associated with exposure to elevated concentrations in the lower atmosphere. An instrument concept to enable such a measurement capability for tropospheric (and total) O-3 utilizing Fabry-Perot interferometry has been developed and reported in earlier work. It involves a double-etalon series configuration Fabry-Perot interferometer (FPI) along with an ultra-narrow bandpass filter to achieve single-order operation with an overall spectral resolution of approximately .068 cm(-1), sampling a narrow spectral region within the strong 9.6 mu m ozone infrared band from a nadir-viewing satellite configuration. Current research efforts are focusing on technology development and demonstration activities to address technology drivers and other design considerations associated with this measurement concept. Most importantly, we have developed a small-scale, modular, double-etalon prototype FPI for laboratory characterization and testing. This presentation will focus on advancements made pertaining to our laboratory prototype, specifically, toward the analysis and interpretation of measured solar absorption spectra. Topics will include processing of "measured" spectra (i.e., spectral registration and drift correction) and simulation of "true" spectra (i.e., atmospheric assumptions and instrument transfer function modeling), as well as subsequent comparisons and findings. Future developments will focus on incorporating other key elements into the prototype instrument, performing relevant laboratory and atmospheric testing, and developing methods for calibration. These activities along with concurrent scientific studies and atmospheric field testing will serve to demonstrate overall feasibility and provide technique validation for this instrumentation and may lead to a future space-based implementation. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Larar, AM (reprint author), NASA, Langley Res Ctr, MS 401A, Hampton, VA 23681 USA. NR 10 TC 8 Z9 8 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2892-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3437 BP 158 EP 166 DI 10.1117/12.331298 PG 9 WC Engineering, Aerospace; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BM32P UT WOS:000078391700016 ER PT S AU Bandara, S Gunapala, S Liu, J Luong, E Mumolo, J McKelvy, M Hong, W AF Bandara, S Gunapala, S Liu, J Luong, E Mumolo, J McKelvy, M Hong, W BE Andresen, BF Strojnik, M TI Quantum well infrared photodetectors for long wavelength infrared applications SO INFRARED TECHNOLOGY AND APPLICATIONS XXIV, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Technology and Applications XXIV CY JUL, 1998 CL SAN DIEGO, CA SP SPIE AB Quantum Well Infrared Photodetectors (QWIPs) offer greater flexibility than usual extrinsically doped semiconductor IR detectors because the wavelength of the peak response and cutoff can be continuously tailored by varying layer thickness (well width), barrier composition (barrier height), and carrier density (well doping density). The GaAs/AlxGa1-xAs material system allows the quantum well parameters to be varied over a range wide enough to enable light detection at any wavelength range between 6-20 mu m [Ref 1,2]. The spectral band width of these detectors can be tuned from narrow (Delta lambda/lambda similar to 10%) to wide (Delta lambda/lambda similar to 40%), allowing various applications [Ref 3]. Also, QWIP device parameters can be optimized to achieve extremely high performance at lower operating temperatures (similar to 40 K) for low background, long-wavelength, infrared applications in the strategic arena as well as in Astronomy. Furthermore, QWIPs offer low cost per pixel and highly uniform, large format. focal plane arrays (FPAs) mainly due to mature GaAs/AlGaAs growth and processing technologies. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Bandara, S (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2891-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3436 BP 280 EP 284 DI 10.1117/12.328000 PN 1-2 PG 5 WC Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BM07M UT WOS:000077548500032 ER PT B AU Hughes, WO McNelis, AM AF Hughes, WO McNelis, AM GP IES TI Characterization of the pyroshock environment for the EOS mission SO INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY - 1998 PROCEEDINGS: DESIGN, TEST, AND EVALUATION PRODUCT RELIABILITY LA English DT Proceedings Paper CT 44th Annual Technical Meeting of the Institute-of-Environmental-Sciences-and-Technology on the 21st Century - A New Frontier in International Information Exchange CY APR 26-MAY 01, 1998 CL PHOENIX, AZ SP Inst Environm Sci & Technol DE Atlas IIAS; attenuation; EOS; pyroshock; SRS; shock; shock response; shock testing; spacecraft separation shock testing AB The Earth Observing System (EOS) spacecraft will launch on an Atlas IIAS launch vehicle on NASA's mission to planet Earth in late 1998. The new design of the spacecraft's pyroshock separation system was characterized by a series of separation test firings by the launch vehicle's contractor, Lockheed Martin Astronautics (LMA). The test data from these shock firings will be assessed in this paper, with particular emphasis on how the shock levels travels downward from the spacecraft's separation interface to the Centaur's (upper stage) equipment module and avionics components. The affect of component's weight and fidelity will be highlighted, in addition to discussing the shock attenuation with distance and across joints. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Hughes, WO (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST ENVIRONMENTAL SCIENCES PI MT PROSPECT PA 940 E NORTHWEST HIGHWAY, MT PROSPECT, IL 60056 USA BN 1-877862-63-0 PY 1998 BP 93 EP 104 PG 4 WC Acoustics; Environmental Sciences; Instruments & Instrumentation SC Acoustics; Environmental Sciences & Ecology; Instruments & Instrumentation GA BL14X UT WOS:000074492400012 ER PT B AU Gibbel, M Cornford, S Hoffman, A Gross, M AF Gibbel, M Cornford, S Hoffman, A Gross, M GP IES TI Metrics evaluations for environmental and reliability testing SO INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY - 1998 PROCEEDINGS: DESIGN, TEST, AND EVALUATION PRODUCT RELIABILITY LA English DT Proceedings Paper CT 44th Annual Technical Meeting of the Institute-of-Environmental-Sciences-and-Technology on the 21st Century - A New Frontier in International Information Exchange CY APR 26-MAY 01, 1998 CL PHOENIX, AZ SP Inst Environm Sci & Technol DE test effectiveness; environmental testing; reliability testing; test evaluations; metrics evaluations; electromagnetic compatibility; pyroshock; risk electromagnetic management AB NASA's Code QE Test Effectiveness Program is funding a series of applied research activities focused on utilizing the principles of physics and engineering of failure along with those of engineering economics to assess and improve the value added by various validation and verification activities. Presented here in are the latest metric evaluations for the effectiveness of the tests involved in one of JPL's recent space flight programs. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gibbel, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST ENVIRONMENTAL SCIENCES PI MT PROSPECT PA 940 E NORTHWEST HIGHWAY, MT PROSPECT, IL 60056 USA BN 1-877862-63-0 PY 1998 BP 224 EP 232 PG 3 WC Acoustics; Environmental Sciences; Instruments & Instrumentation SC Acoustics; Environmental Sciences & Ecology; Instruments & Instrumentation GA BL14X UT WOS:000074492400030 ER PT B AU Cornford, S Gibbel, M Larson, T AF Cornford, S Gibbel, M Larson, T GP IES TI Assessing the effectiveness of environmental test programs SO INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY - 1998 PROCEEDINGS: DESIGN, TEST, AND EVALUATION PRODUCT RELIABILITY LA English DT Proceedings Paper CT 44th Annual Technical Meeting of the Institute-of-Environmental-Sciences-and-Technology on the 21st Century - A New Frontier in International Information Exchange CY APR 26-MAY 01, 1998 CL PHOENIX, AZ SP Inst Environm Sci & Technol DE test effectiveness; environmental testing; test improvement; optimization; test tailoring; metrics evaluations; corporate culture; anomaly data AB NASA's Code QE Test Effectiveness Program is funding a series of applied research activities focused on utilizing the principles of physics and engineering of failure along with those of engineering economics to assess and improve the value added by various validation and verification activities, with the primary emphasis being on testing. Presented herein is a review of the methodology and data sources required for successful metrics evaluations and the utility to, and feasibility of implementing at, other organizations. Also covered are brief examples of test metrics which enable useful evaluations as well as a brief summary of the relevant failure modes, effectiveness of the test control parameters on screening effectiveness, and applicability of the metrics defined. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cornford, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST ENVIRONMENTAL SCIENCES PI MT PROSPECT PA 940 E NORTHWEST HIGHWAY, MT PROSPECT, IL 60056 USA BN 1-877862-63-0 PY 1998 BP 233 EP 238 PG 6 WC Acoustics; Environmental Sciences; Instruments & Instrumentation SC Acoustics; Environmental Sciences & Ecology; Instruments & Instrumentation GA BL14X UT WOS:000074492400031 ER PT S AU Westall, F Gerneke, D AF Westall, F Gerneke, D BE Hoover, RB TI Electron microscope methods in the search for the earliest life forms on Earth (in 3.5-3.3 Ga cherts from the Barberton greenstone belt, South Africa): applications for extraterrestrial life studies SO INSTRUMENTS, METHODS, AND MISSIONS FOR ASTROBIOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instruments, Methods, and Missions for Astrobiology CY JUL 20-22, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE Early Archean; fossil bacteria; fossil biofilm; extraterrestrial life; Mars; scanning electron microscopy AB A suite of previously unknown microfossils and related biogenic structures (biofilm) has been revealed in some of the oldest sediments on Earth (the 3.5-3.3 Ga Barberton greenstone belt in South Africa) using scanning electron microscopy. High resolution scanning electron microscopy of HE-etched, biolaminated cherts has brought to light a variety of small fossil coccoid (0.3-1 mu m in diameter) and rod-shaped bacteria (0.6-4 mu m in length) and associated fossil biofilms coating bedding planes. These microfossils have been completely replaced by minerals. This vastly improved Early Archean microfossil database (including bacterial biofilm) sheds new light on the diversity of life on Earth relatively soon after the cessation of heavy bolide bombardment at about 3.8 Ga. This is the critical period when life may have been able to develop on Mars and these Early Archean terrestrial microfossils will serve as valuable analogues for possible extraterrestrial life. C1 NASA, Johnson Space Ctr, Houston, TX 77058 USA. RP Westall, F (reprint author), NASA, Johnson Space Ctr, Mail Stop SN2, Houston, TX 77058 USA. NR 0 TC 7 Z9 7 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2896-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3441 BP 158 EP 169 DI 10.1117/12.319833 PG 12 WC Biology; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing SC Life Sciences & Biomedicine - Other Topics; Geology; Instruments & Instrumentation; Remote Sensing GA BM19W UT WOS:000078010100017 ER PT S AU McKay, DS Rozanov, AY Hoover, RB Westall, F AF McKay, DS Rozanov, AY Hoover, RB Westall, F BE Hoover, RB TI Phosphate biomineralization of Cambrian microorganisms SO INSTRUMENTS, METHODS, AND MISSIONS FOR ASTROBIOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instruments, Methods, and Missions for Astrobiology CY JUL 20-22, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers AB As part of a long term study of biological markers (biomarkers), we are documenting a variety of features which reflect the previous presence of living organisms. As we study meteorites and samples returned from Mars, our main clue to recognizing possible microbial material may be the presence of biomarkers rather than the organisms themselves. One class of biomarkers consists of biominerals which have either been precipitated directly by microorganisms, or whose precipitation has been influenced by the organisms. Such microbe-mediated mineral formation may include important clues to the size, shape, and environment of the microorganisms. The process of fossilization or mineralization can cause major changes in morphologies and textures of the original organisms. The study of fossilized terrestrial organisms can help provide insight into the interpretation of mineral biomarkers. This pager describes the results of investigations of microfossils in Cambrian phosphate-rich rocks (phosphorites) that were found in Khubsugul, Northern Mongolia. C1 NASA, Johnson Space Ctr, Earth Sci & Solar Syst Explorat Div, Houston, TX 77958 USA. RP McKay, DS (reprint author), NASA, Johnson Space Ctr, Earth Sci & Solar Syst Explorat Div, Mail Code SN, Houston, TX 77958 USA. NR 0 TC 10 Z9 10 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2896-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3441 BP 170 EP 176 DI 10.1117/12.319834 PG 7 WC Biology; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing SC Life Sciences & Biomedicine - Other Topics; Geology; Instruments & Instrumentation; Remote Sensing GA BM19W UT WOS:000078010100018 ER PT S AU Hoover, RB Rozanov, AY Zhmur, SI Gorlenko, VM AF Hoover, RB Rozanov, AY Zhmur, SI Gorlenko, VM BE Hoover, RB TI Further evidence of microfossils in carbonaceous chondrites SO INSTRUMENTS, METHODS, AND MISSIONS FOR ASTROBIOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instruments, Methods, and Missions for Astrobiology CY JUL 20-22, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE astrobiology; cyanobacteria; microfossils; Murchison; Orgueil; Efremovka; meteorites; phosphorites AB Scanning electron microscopy investigations carried out independently in the United States and Russia have yielded further evidence of microfossils in meteorites. Numerous complex biomorphic microstructures representing possible microfossils have been found in interior surfaces of freshly broken samples of the Murchison, Orgueil, and Efremovka carbonaceous chondrites. Similar biomorphic forms were not encountered during comparable investigations of the Nikolskoye meteorite. Energy Dispersive Spectroscopy (EDS) and Link microprobe analysis provides elemental distributions indicating many of the microstructures have a carbon enhancement that is superimposed upon composition of the meteoritic matrix. The in-situ mineralized biomorphic microstructures found embedded in freshly fractured meteoritic surfaces are not considered to be recent surface contaminants. C1 NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. RP Hoover, RB (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Lab, ES-82, Huntsville, AL 35812 USA. NR 0 TC 27 Z9 27 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2896-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3441 BP 203 EP 216 DI 10.1117/12.319839 PG 14 WC Biology; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing SC Life Sciences & Biomedicine - Other Topics; Geology; Instruments & Instrumentation; Remote Sensing GA BM19W UT WOS:000078010100023 ER PT S AU Westall, F Gobbi, P Mazzotti, G Gerneke, D Stark, RW Drobek, T Heckl, WM Gibson, E McKay, D Allen, C Steele, A Thomas-Keprta, K AF Westall, F Gobbi, P Mazzotti, G Gerneke, D Stark, RW Drobek, T Heckl, WM Gibson, E McKay, D Allen, C Steele, A Thomas-Keprta, K BE Hoover, RB TI Combined SEM (secondary electrons, backscatter, cathodoluminescence) and atomic force microscope investigation of fracture surfaces in Martian meteorite ALH84001: preliminary results SO INSTRUMENTS, METHODS, AND MISSIONS FOR ASTROBIOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instruments, Methods, and Missions for Astrobiology CY JUL 20-22, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers AB A variety of microscope techniques has been used to study surficial phenomena on the fracture surfaces of the Martian meteorite ALH84001. The aim of the investigation was to determine the most useful microscopic methods in the search for morphological signs of biogenic activity. Emphasis was placed on scanning electron microscopy (SEM) using secondary, backscatter and cathodoluminescence modes combined with observation of samples at a variety of accelerating voltages (120 KV). High resolution SEM imaging was compared with atomic force microscopy(AFM). These techniques revealed a number of structures of possible abiotic and biotic origin: (1) a large (150 x 50 mu m), fibrous-looking carbonaceous structure, (2) fine, flaky films (tens of nanometers thick) coating pyroxene surfaces, (3) finely granular calcium carbonate deposits associated with the fine film, and (4) lacy-structured, mineralised polymers on the pyroxene surface. Another sample contains further evidence of water-lain deposits in a cracked, iron oxide coat on a fracture surface. C1 Univ Bologna, DIPROVAL, I-40126 Bologna, Italy. RP Westall, F (reprint author), NASA, Lyndon B Johnson Space Ctr, SN2, Houston, TX 77058 USA. RI Gobbi, Pietro/J-2566-2012; Stark, Robert/A-2886-2008 OI Gobbi, Pietro/0000-0003-4705-0833; Stark, Robert/0000-0001-8678-8449 NR 0 TC 2 Z9 2 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2896-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3441 BP 225 EP 233 DI 10.1117/12.319841 PG 9 WC Biology; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing SC Life Sciences & Biomedicine - Other Topics; Geology; Instruments & Instrumentation; Remote Sensing GA BM19W UT WOS:000078010100025 ER PT J AU Miranda, FA Van Keuls, FW Romanofsky, RR Subramanyam, G AF Miranda, FA Van Keuls, FW Romanofsky, RR Subramanyam, G TI Tunable microwave components for Ku- and K-band satellite communications SO INTEGRATED FERROELECTRICS LA English DT Article DE ferroelectric thin films; tunable microwave components; filters; phase shifters; resonators; Ku- and K-band frequencies; satellite communications AB The use of conductor/ferroelectric/dielectric thin film multilayer structures for frequency and phase agile components at frequencies at and above the Ku-band will be discussed. Among these components are edge coupled filters, microstripline ring resonators, and phase shifters. These structures were implemented using SrTiO3 (STO) ferroelectric thin films, with gold or YBa2Cu3O7-delta (YBCO) high temperature superconducting (HTS) microstrip lines deposited by laser ablation on LaAlO3 (LAO) substrates. The performance of these structures in terms of tunability, operating temperature, frequency, and de bias will be presented. Because of their small size, light weight, and low loss, these tunable microwave components are being studied very intensely at NASA as well as by the commercial communication industry. An assessment of the progress made so far, and the issues yet to be solved for the successful integration of these components into the aforementioned communication systems will be presented. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Univ No Iowa, Cedar Falls, IA 50614 USA. RP Miranda, FA (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 18 TC 4 Z9 4 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 22 IS 1-4 BP 789 EP 798 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WX UT WOS:000076544300026 ER PT J AU van Keuls, FW Romanofsky, RR Bohman, DY Miranda, FA AF van Keuls, FW Romanofsky, RR Bohman, DY Miranda, FA TI Influence of the biasing scheme on the performance of Au/SrTiO3/LaAlO3 thin film conductor/ferroelectric tunable ring resonators SO INTEGRATED FERROELECTRICS LA English DT Article DE Tunable Ring Resonators; Ku-band frequencies; ferroelectric thin films; biasing scheme; quality factor ID MICROSTRIP LINE AB The performance of gold/SrTiO3/LaAlO3 conductor/ferroelectric/dielectric side-coupled, tunable ring resonators at Ku-band frequencies is presented. The tunability of these rings arises from the sensitivity of the relative dielectric constant (epsilon(r)) of SrTiO3 to changes in temperature and de electric fields (E). We observed that the change in epsilon(r) which takes place by biasing the ring up to 450 V alters the effective dielectric constant (epsilon(eff)) of the circuit resulting in a 3 lambda resonant frequency shift of nearly 12% at 77 K. By applying a separate de bias between the microstrip line and the ring, one can optimize their coupling to obtain high Q bandstop resonators with delta f(n)(-1) = f(o)/Delta f(3dB) as high as 12,000. The 3 lambda resonance was tuned from 15.75 to 17.41 GHz while keeping delta f(n)(-1) above 768 over this range. The relevance of these results for practical microwave components will be discussed. C1 NASA, Lewis Res Ctr, Natl Res Council, Cleveland, OH 44135 USA. RP van Keuls, FW (reprint author), NASA, Lewis Res Ctr, Natl Res Council, Cleveland, OH 44135 USA. NR 14 TC 8 Z9 8 U1 0 U2 2 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 22 IS 1-4 BP 883 EP 892 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WX UT WOS:000076544300034 ER PT J AU van Keuls, FW Romanofsky, RR Miranda, FA AF van Keuls, FW Romanofsky, RR Miranda, FA TI Several microstrip-based conductor/thin film ferroelectric phase shifter designs using (YBa2Cu3O7-delta, Au)/SrTiO3/LaAlO3 structures SO INTEGRATED FERROELECTRICS LA English DT Article DE microwave frequencies; phase shifter; ferroelectric thin films; microstrip lines; Ku-band; HTS thin films ID DEVICES AB We have designed, fabricated, and tested several novel microstrip-based YBa2Cu3O7-delta/SrTiO3/LaAlO3 (YBCO/STO/LAO) and Au/SrTiO3/LaAlO3 (Au/ STO/LAO) phase shifters. The first design consists of eight coupled microstrip phase shifters (CMPS) in series. This design using YBCO achieved a relative insertion phase shift (Delta phi) of 484 degrees with a figure of merit of 80 degrees/dB at V-dc = 375 V, 16 GHz, and 40 K. A Delta phi of 290 degrees was observed while maintaining the insertion loss below 4.5 dB. At 77 K, a Delta phi of 420 degrees was obtained for this phase shifter at the same bias and frequency. Both results correspond to an effective coupling length of 0.33 cm. A second compact design, consisting of an An meander line and a CMPS section was also tested. Of the two samples tested, the best showed a figure of merit of 43 degrees/dB with Delta phi = 290 degrees and 6.8 dB loss, at 40 K, 10 GHz and 400 V. Experimental and modeling results on these circuits will be discussed in the context of potential applications. C1 NASA, Lewis Res Ctr, Natl Res Council, Cleveland, OH 44135 USA. RP van Keuls, FW (reprint author), NASA, Lewis Res Ctr, Natl Res Council, Cleveland, OH 44135 USA. NR 8 TC 10 Z9 10 U1 0 U2 3 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 22 IS 1-4 BP 893 EP 901 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WX UT WOS:000076544300035 ER PT J AU Macleod, TC Ho, FD AF Macleod, TC Ho, FD TI Modeling of metal-ferroelectric-semiconductor field effect transistors SO INTEGRATED FERROELECTRICS LA English DT Article DE ferroelectric transistors; hysteresis modeling; ferroelectric time decay AB The characteristics for a MFS FET (metal-ferroelectric-semiconductor field effect transistor) is very different than a conventional MOSFET and must be modeled differently. The drain current has a hysteresis shape with respect to the gate voltage. The position along the hysteresis curve is dependent on the last positive or negative polling of the ferroelectric material, The drain current also has a logarithmic decay after the last polling. A model has been developed to describe the MFSFET drain current for both gate voltage on and gate voltage off conditions. This model takes into account the hysteresis nature of the MFSFET and the time dependent decay. The model is based on the shape of the Fermi-Dirac function which has been modified to describe the MFSFET's drain current. This is different from the model proposed by Chen et. al.([1]) and that by Wu([2]). C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. RP Macleod, TC (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 6 TC 7 Z9 7 U1 0 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 21 IS 1-4 BP 127 EP 143 DI 10.1080/10584589808202057 PG 17 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WV UT WOS:000076544100013 ER PT S AU Lin, SC Wilkins, R Luss, D AF Lin, SC Wilkins, R Luss, D BE Pandey, RK Witter, DE Varshney, U TI Self-propagating high-temperature synthesis of Cd-In-Ga-O powder for GaN thin film substrate SO INTEGRATED THIN FILMS AND APPLICATIONS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Integrated Thin Films and Applications, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 04-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc DE self-propagating high-temperature synthesis; Cd-In-Ga-O; GaN AB The lack of an economical lattice matched substrate is a recognized problem for GaN film growth. The crystalline of CdIn1.673Ga0.327O4, having a lattice constant of 9.04 Angstrom (2x cubic GaN), may be a good substrate for GaN thin film growth. Preliminary results are reported on the processing of the Cd-In-Ga oxide using the Self-propagating High-temperature Synthesis. This method allows very rapid production compared with the traditional solid state reaction synthesis, XRD was used to identify the crystal structure. Electron Microprobe Analysis (EMPA) was used to analyze the compositions in different phases of the powder after the combustion. TG/DTA was used to investigate the phase changes and possible reactions among reactants. Different precursor powders, pellet diameters, pellet densities were used to study their impact on the product quality. The temperature history during the combustion process was recorded. C1 Prairie View A&M Univ, NASA, Ctr Appl Radiat Res, Prairie View, TX 77446 USA. RP Lin, SC (reprint author), Prairie View A&M Univ, NASA, Ctr Appl Radiat Res, Prairie View, TX 77446 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-032-7 J9 CERAM TRANS PY 1998 VL 86 BP 73 EP 85 PG 13 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BL05W UT WOS:000074135200006 ER PT J AU Jamshidi, M AF Jamshidi, M TI Fuzzy control systems stability: Time and frequency domain criteria SO INTELLIGENT AUTOMATION AND SOFT COMPUTING LA English DT Article DE stability; fuzzy control; frequency domain; time domain; interval matrix ID NONLINEAR-SYSTEMS; LOGIC CONTROLLER; DESIGN; SISO AB Stability is the most important attribute of any system. A prerequisite for all stability criteria of control systems is the existence of a mathematical model. In contrast, fuzzy control systems are often designed based on heuristic human knowledge and without a mathematical model, hence, it has been a difficult task to determine stability of fuzzy control systems under such restrictions. This paper uses the Takagi/Sugeno type of Fuzzy rules whose consequences are analytical, and singletons are used as a basis for a number of sufficiency conditions for stability. The schemes considered here are time-domain, but a brief survey which proceeds the main results considers frequency domain as well. Both Lyapunov and interval matrix criteria are presented with some proofs and numerical examples. C1 Univ New Mexico, NASA, Ctr Autonomous Control Engn, Albuquerque, NM 87131 USA. CNRS, LAAS, F-31077 Toulouse, France. RP Jamshidi, M (reprint author), Univ New Mexico, NASA, Ctr Autonomous Control Engn, 125 EECE Bldg, Albuquerque, NM 87131 USA. EM jamshidi@unm.edu NR 45 TC 0 Z9 0 U1 0 U2 1 PU AUTOSOFT PRESS PI ALBUGUERQUE PA PO BOX 14126, ALBUGUERQUE, NM 87191-4126 USA SN 1079-8587 J9 INTELL AUTOM SOFT CO JI Intell. Autom. Soft Comput. PY 1998 VL 4 IS 2 BP 109 EP 129 PG 21 WC Automation & Control Systems; Computer Science, Artificial Intelligence SC Automation & Control Systems; Computer Science GA 135ZE UT WOS:000076832300002 ER PT B AU Hayati, S AF Hayati, S BE Salichs, MA Halme, A TI Robotic planetary surface exploration SO INTELLIGENT AUTONOMOUS VECHICLES 1998 (IAV'98) LA English DT Proceedings Paper CT 3rd IFAC Symposium on Intelligent Autonomous Vehicles 1998 (IAV 98) CY MAR 25-27, 1998 CL MADRID, SPAIN SP Int Federat Automat Control, Tech Comm Intelligent Autonomous Vehicles, IFAC Tech Comm Aerospace, IFAC Tech Comm Marine Syst, Universidad Carlos III, Madrid AB This is a brief text of speech given by the author as the opening plenary talk at the 3(rd) IFAC Symposium on Intelligent Autonomous Vehicles. After a brief introduction about JPL's past, present, and future missions, it presents Sojourner rover and its accomplishments as well as JPL's research on Long Range Science Revers. References 1, 2, and 3 provide additional information. Copyright (C) 1998 IFAC. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Hayati, S (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND BN 0-08-042929-7 PY 1998 BP 1 EP 6 PG 6 WC Automation & Control Systems; Computer Science, Interdisciplinary Applications; Instruments & Instrumentation; Transportation SC Automation & Control Systems; Computer Science; Instruments & Instrumentation; Transportation GA BM77L UT WOS:000079728100001 ER PT S AU Schenker, PS Baumgartner, ET Lindemann, RA Aghazarian, H Zhu, DQ Ganino, AJ Sword, LF Garrett, MS Kennedy, BA Hickey, GS Lai, AS Matthies, LH Hoffman, BD Huntsberger, TE AF Schenker, PS Baumgartner, ET Lindemann, RA Aghazarian, H Zhu, DQ Ganino, AJ Sword, LF Garrett, MS Kennedy, BA Hickey, GS Lai, AS Matthies, LH Hoffman, BD Huntsberger, TE BE Casasent, DP TI New planetary rovers for long range Mars science and sample return SO INTELLIGENT ROBOTS AND COMPUTER VISION XVII: ALGORITHMS, TECHNIQUES, AND ACTIVE VISION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Intelligent Robots and Computer Vision XVII - Algorithms, Techniques, and Active Vision CY NOV 02-03, 1998 CL BOSTON, MA SP SPIE Int Soc Opt Engn DE mobile robots; 3D sensing; sensor fusion; space manipulators; robotic sampling; Mars sample return planetary science AB There are significant international efforts underway to place mobile robots ("rovers") on the surface of Mars. This follows on the recent successful NASA Mars Pathfinder flight of summer 1997. In that mission, the 11+ Kg Sojourner rover explored a small 50 meter locale about its lander over a several week period. Future planned science missions of the Mars Surveyor Program are more aggressive, seeking to autonomously survey planetary climate, life and resources over multiple kilometers and many months duration. These missions will also retrieve collected sample materials back to a Mars Ascent Vehicle (MAV) for more detailed analysis an Earth. In support of these future missions we are developing and field testing new rover technology concepts. We first overview the design and initial operations of SRR-1 (Sample Return Rover), a novel 10 kg-class four wheel, hybrid composite-metal vehicle for rapid (10-30 cm/sec) autonomous location, rendezvous, and retrieval of collected samples under integrated visual and beacon guidance. SRR is a light 88x55x36 (LWH) cm(3) vehicle collapsing to less than one third its deployed field volume, and carrying a powerful, visually-servoed all-composite manipulator. We then sketch development of the FIDO rover (Field Integrated Design & Operations), a new 50+ kg, six wheel, similar to 100x80x50 (LWH) cm(3) high mobility, multi-km range science vehicle which includes mast-mounted multi-spectral stereo, bore-sighted IR point spectrometer, robot arm with attached microscope, and body-mounted rock: sampling corer. Currently in integration phase, FIDO rover will first be tested in September, 1998, "MarsYard (JPL)" operations, followed by CY99 full-scale terrestrial field simulations of a planned Mars '03 multi-kilometer roving mission (Athena-based science rover payload), demonstrating remote science selection, autonomous navigation, ia situ sample analysis, and robotic sample collection functions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Schenker, PS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 125-224, Pasadena, CA 91109 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2983-X J9 P SOC PHOTO-OPT INS PY 1998 VL 3522 BP 2 EP 15 DI 10.1117/12.325751 PG 14 WC Computer Science, Artificial Intelligence; Engineering, Industrial SC Computer Science; Engineering GA BL91X UT WOS:000077140600001 ER PT S AU McCandless, JW Ahumada, AJ AF McCandless, JW Ahumada, AJ BE Casasent, DP TI A predictive optical flow algorithm for aircraft detection SO INTELLIGENT ROBOTS AND COMPUTER VISION XVII: ALGORITHMS, TECHNIQUES, AND ACTIVE VISION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Intelligent Robots and Computer Vision XVII - Algorithms, Techniques, and Active Vision CY NOV 02-03, 1998 CL BOSTON, MA SP SPIE Int Soc Opt Engn DE gradient; optical flow; object detection; vector; computer vision; video images AB A computer vision algorithm was developed to detect moving aircraft located in video images. Using a gradient-based approach, the algorithm computes optical flow vectors in each frame of the sequence. Vectors with similar characteristics (location, magnitude, and direction) are clustered together using a spatial consistency test. Vectors that pass the spatial consistency test are extended temporally to make predictions about the optical flow locations, magnitudes, and directions in subsequent frames. The actual optical flow vectors that are consistent with the predicted vectors are labeled as vectors associated with a moving target. The algorithm was tested on images obtained with a video camera mounted below the nose of a Boeing 737. The algorithm correctly detected an aircraft from a distance of one mile in over 80% of the frames with zero false alarms. C1 NASA, Ames Res Ctr, Human Informat Proc Res Branch, Moffett Field, CA 94035 USA. RP McCandless, JW (reprint author), NASA, Ames Res Ctr, Human Informat Proc Res Branch, Mail Stop 262-2, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2983-X J9 P SOC PHOTO-OPT INS PY 1998 VL 3522 BP 193 EP 203 DI 10.1117/12.325764 PG 11 WC Computer Science, Artificial Intelligence; Engineering, Industrial SC Computer Science; Engineering GA BL91X UT WOS:000077140600020 ER PT S AU Spelt, PF Kirson, AM Scott, S AF Spelt, PF Kirson, AM Scott, S GP NRC TI New vehicle data bus architecture and in-vehicle information system evaluation platform for intelligent transportation systems modules SO INTELLIGENT TRANSPORTATION SYSTEMS, AUTOMATED HIGHWAY SYSTEMS, TRAVELER INFORMATION, AND ARTIFICIAL INTELLIGENCE SE TRANSPORTATION RESEARCH RECORD LA English DT Article; Proceedings Paper CT 77th Annual Meeting of the Transportation-Research-Board CY JAN, 1998 CL WASHINGTON, D.C. SP Transportat Res Board AB An increasing number of intelligent transportation systems-(ITS-) after-market systems present a set of in-vehicle installation and use problems relatively unique in the history of automobile use. Many automobile manufacturers would like to offer these new state-of-the-art devices to customers, but are hampered by the current design cycle of new cars. While automobile manufacturers are indeed using multiplex buses [the automotive equivalent of a computer local area network (LAN)], problems remain because manufacturers are not converging on a single bus standard. A new dual-bus architecture to address these problems is presented with an in-vehicle information system (IVIS) research platform on which the principles embodied in the ITS data bus architecture can be evaluated. The dual-bus architecture has been embodied in a proposed Society of Automotive Engineers (SAE) standard, with support from both automobile and consumer electronics manufacturers. The architecture and a reference model for the interfaces and protocols of the new bus are presented and described. The goals of the ITS data bus are to be inexpensive and easy to install, and to provide for safe and secure functioning. These high-level goals are embodied in the proposed standard. The IVIS development platform comprises a number of personal computers (PCs) linked via ethernet LAN, with a high-end PC serving as the IVIS computer. In this LAN, actual devices can be inserted in place of the original PC that emulated them. This platform will serve as the development and test bed for an ITS data bus conformity test, the SAE standard for which is also being developed. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Motorola Inc, Northbrook, IL 60062 USA. Jet Prop Lab, Washington, DC 20024 USA. RP Spelt, PF (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 6025,MS 6364, Oak Ridge, TN 37831 USA. NR 10 TC 0 Z9 0 U1 1 U2 2 PU NATL ACAD SCI PI WASHINGTON PA 2101 CONSTITUTION AVE, WASHINGTON, DC 20418 USA SN 0361-1981 BN 0-309-06523-2 J9 TRANSPORT RES REC PY 1998 IS 1651 BP 17 EP 22 PG 6 WC Engineering, Civil; Transportation SC Engineering; Transportation GA BN49C UT WOS:000082031200003 ER PT J AU Gu, JD Roman, M Esselman, T Mitchell, R AF Gu, JD Roman, M Esselman, T Mitchell, R TI The role of microbial biofilms in deterioration of space station candidate materials SO INTERNATIONAL BIODETERIORATION & BIODEGRADATION LA English DT Article; Proceedings Paper CT 10th International Biodeterioration and Biodegradation Symposium CY SEP 15-18, 1996 CL HAMBURG, GERMANY DE biofilms; degradation; microbial; polymeric materials; space station ID SULFATE-REDUCING BACTERIA; CORROSION; DEGRADATION; ENDOTOXIN; SURVIVAL; GROWTH; SYSTEM; WATER; STEEL AB Formation of microbial biofilms on surfaces of a wide range of materials being considered as candidates for use on the International Space Station was investigated. The materials included a fibre-reinforced polymeric composite, an adhesive sealant, a polyimide insulation foam, teflon cable insulation, titanium, and an aliphatic polyurethane coating. They were exposed to a natural mixed population of bacteria under controlled conditions of temperature and relative humidity (RH). Biofilms formed on the surfaces of the materials at a wide range of temperatures and RHs. The biofilm population was dominated by Pseudomonas aeruginosa, Ochrobactrum anthropi, Alcaligenes denitrificans, Xanthomonas maltophila, and Vibrio harveyi. The biocide, diiodomethyl-p-tolylsulfone, impregnated in the polyurethane coating, was ineffective against microbial colonization and growth. Degradation of the polyurethane coatings was monitored with electrochemical impedance spectroscopy (EIS). The impedance spectra indicated that microbial degradation of the coating occurred in several stages. The initial decreases in impedance were due to the transport of water and solutes into the polymeric matrices. Further decreases were a result of polymer degradation by microorganisms. Our data showed that these candidate materials for space application are susceptible to biofilm formation and subsequent degradation. Our study suggests that candidate materials for use in space missions need to be carefully evaluated for their susceptibility to microbial biofilm formation and biodegradation. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Harvard Univ, Div Appl Sci, Microbial Ecol Lab, Cambridge, MA 02138 USA. NASA, Life Support Syst Branch, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Altran Mat Engn Inc, Cambridge, MA 02139 USA. RP Mitchell, R (reprint author), Harvard Univ, Div Appl Sci, Microbial Ecol Lab, Cambridge, MA 02138 USA. NR 65 TC 47 Z9 56 U1 1 U2 14 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0964-8305 J9 INT BIODETER BIODEGR JI Int. Biodeterior. Biodegrad. PY 1998 VL 41 IS 1 BP 25 EP 33 DI 10.1016/S0964-8305(97)00070-X PG 9 WC Biotechnology & Applied Microbiology; Environmental Sciences SC Biotechnology & Applied Microbiology; Environmental Sciences & Ecology GA ZT843 UT WOS:000074133400004 PM 11541393 ER PT B AU Springer, PL AF Springer, PL BE Arabnia, HR TI Matpar: Parallel extensions for MATLAB SO INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED PROCESSING TECHNIQUES AND APPLICATIONS, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA 98) CY JUL 13-16, 1998 CL LAS VEGAS, NV SP Comp Sci Res, Educ & Applicat Tech, Natl Partnership Adv Computat Infrastruct, US DOE, Natl Supercomp Ctr Energy & Environm, N Amer Transputer Users Grp, Comp Vis Res & Applicat Tech, High Performance Comp Users Grp DE parallel; MATLAB; Matpar; client/server AB Matpar is a set of client/server software that allows a MATLAB user to fake advantage of a parallel computer for very large problems. The user can replace calls to certain built-in MATLAB functions with calls to Matpar functions. These Matpar functions are implemented as standard MATLAB external calls (MEX-files) on the client side. The MEX code in turn initiates a session on a parallel computer. The parallel code uses parallel mathematical libraries to produce a solution that is sent back to the calling program, and returned to the user in a seamless fashion. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Springer, PL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,168-522, Pasadena, CA 91109 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU C S R E A PRESS PI ATHENS PA 115 AVALON DR, ATHENS, GA 30606 USA BN 1-892512-08-4 PY 1998 BP 1191 EP 1195 PG 5 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BR81K UT WOS:000167625200159 ER PT B AU Ricks, KG Wells, BE AF Ricks, KG Wells, BE BE Arabnia, HR TI An analysis of an improved bus-based multiprocessor architecture SO INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED PROCESSING TECHNIQUES AND APPLICATIONS, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA 98) CY JUL 13-16, 1998 CL LAS VEGAS, NV SP Comp Sci Res, Educ & Applicat Tech, Natl Partnership Adv Computat Infrastruct, US DOE, Natl Supercomp Ctr Energy & Environm, N Amer Transputer Users Grp, Comp Vis Res & Applicat Tech, High Performance Comp Users Grp DE multiprocessors; parallel architectures; multicomputers; Monte Carlo analysis; static allocation AB This paper analyses the effectiveness of a hybrid multiprocessing/multicomputing architecture that is based upon a single-board-computer multiprocessor (SBCM) architecture. Based upon empirical analysis using discrete event simulations and Monte Carlo techniques, this hybrid architecture, called the enhanced single-board-computer multiprocessor (ESBCM), is shown to have improved performance and scalability characteristics over current SBCM designs. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Ricks, KG (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU C S R E A PRESS PI ATHENS PA 115 AVALON DR, ATHENS, GA 30606 USA BN 1-892512-08-4 PY 1998 BP 1447 EP 1454 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BR81K UT WOS:000167625200193 ER PT B AU Wissink, A Meakin, R AF Wissink, A Meakin, R BE Arabnia, HR TI Computational fluid dynamics with adaptive overset grids on parallel and distributed computer platforms SO INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED PROCESSING TECHNIQUES AND APPLICATIONS, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA 98) CY JUL 13-16, 1998 CL LAS VEGAS, NV SP Comp Sci Res, Educ & Applicat Tech, Natl Partnership Adv Computat Infrastruct, US DOE, Natl Supercomp Ctr Energy & Environm, N Amer Transputer Users Grp, Comp Vis Res & Applicat Tech, High Performance Comp Users Grp DE CFD; overset; parallel; MPI AB This paper explores the parallel implementation of a new Computational Fluid Dynamics (CFD) scheme based on structured overset Cartesian grids. A coarse-grain parallel implementation approach is used with MPI message passing. Performance of Navier-Stokes computations about two geometrically complex configurations is evaluated on the IBM SP multi-processor. C1 NASA, Ames Res Ctr, MCAT Inc, Moffett Field, CA 94035 USA. RP Wissink, A (reprint author), NASA, Ames Res Ctr, MCAT Inc, Moffett Field, CA 94035 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU C S R E A PRESS PI ATHENS PA 115 AVALON DR, ATHENS, GA 30606 USA BN 1-892512-08-4 PY 1998 BP 1628 EP 1634 PG 7 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BR81K UT WOS:000167625200218 ER PT B AU Lee, RAM Harter, AW Chui, TCP AF Lee, RAM Harter, AW Chui, TCP BE DewHughes, D Scurlock, RG Watson, JHP TI Doped GdCl3 high resolution thermometers for use near to the lambda point SO INTERNATIONAL CRYOGENIC ENGINEERING CONFERENCE 1998 LA English DT Proceedings Paper CT 17th International Cryogenic Engineering Conference CY JUL 14-17, 1998 CL BOURNEMOUTH, ENGLAND SP Air Prod Ltd, A S Sci Ltd, BOC Ltd, BOC Proc Plants, British Cryoengn Soc, Elsevier Sci Ltd, HPC Engn plc, Hyrolec Tech Serv Ltd, Int Cryogen Engn Comm, Int Inst Refrigerat, Oxford Instruments Ltd, Linde Cryogen Ltd, Merck Ltd, Univ Southampton, Weka AG AB The paramagnetic salt GdCl3 was doped with the diamagnetic La3+ ion, depressing its Curie temperature (T-c) from 2.2 K to 2.185 K. A paramagnetic salt thermometer was constructed using this salt and measurements were made of its sensitivity, noise and drift. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lee, RAM (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND BN 0-7503-0597-5 PY 1998 BP 817 EP 820 PG 4 WC Thermodynamics; Engineering, Mechanical; Mechanics; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Mechanics; Physics GA BM16L UT WOS:000077869200187 ER PT B AU Yang, G Yadid-Pecht, O Wrigley, C Pain, B AF Yang, G Yadid-Pecht, O Wrigley, C Pain, B GP IEEE IEEE TI A snap-shot CMOS active pixel imager for low-noise, high-speed imaging SO INTERNATIONAL ELECTRON DEVICES MEETING 1998 - TECHNICAL DIGEST LA English DT Proceedings Paper CT International Electron Devices Meeting (IEDM) CY DEC 06-09, 1998 CL SAN FRANCISCO, CA SP Electron Devices Soc IEEE ID SENSORS AB Design and performance of a 128x128 snap-shot imager implemented in a standard single-poly CMOS technology is presented. A new pixel design and clocking scheme allow the imager to provide high-quality images without notion artifacts at high shutter speeds (< 75 mu sec. exposure), with low noise (< 5 e(-)), immeasurable image lag, and excellent blooming protection. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yang, G (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 12 Z9 12 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4774-9 PY 1998 BP 45 EP 48 DI 10.1109/IEDM.1998.746243 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BM38T UT WOS:000078581800010 ER PT J AU Berenji, HR Khedkar, PS AF Berenji, HR Khedkar, PS TI Using fuzzy logic for performance evaluation in reinforcement learning SO INTERNATIONAL JOURNAL OF APPROXIMATE REASONING LA English DT Article DE reinforcement learning; fuzzy control; neural networks; action evaluation; adaptive critic; intelligent control AB A new architecture is described which uses fuzzy rules to initialize its two neural networks: a neural network for performance evaluation and another for action selection. This architecture, applied to control of dynamic systems, demonstrates that it is possible to start with an approximate prior knowledge and learn to refine it through experiments using Reinforcement Learning (RL). (C) 1998 Elsevier Science Inc. C1 NASA, Intelligent Inference Syst Corp, Computat Sci Div, Ames Res Ctr, Mt View, CA 94035 USA. GE, Res & Dev, Informat Technol Lab, Schenectady, NY 12301 USA. RP Berenji, HR (reprint author), NASA, Intelligent Inference Syst Corp, Computat Sci Div, Ames Res Ctr, Mt View, CA 94035 USA. NR 16 TC 8 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0888-613X J9 INT J APPROX REASON JI Int. J. Approx. Reasoning PD JAN-FEB PY 1998 VL 18 IS 1-2 BP 131 EP 144 DI 10.1016/S0888-613X(97)10007-X PG 14 WC Computer Science, Artificial Intelligence SC Computer Science GA ZT012 UT WOS:000074038800007 ER PT J AU Mosier, KL Skitka, LJ Heers, S Burdick, M AF Mosier, KL Skitka, LJ Heers, S Burdick, M TI Automation bias: Decision making and performance in high-tech cockpits SO INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY LA English DT Article ID ACCOUNTABILITY AB Automated aids and decision support tools are rapidly becoming indispensable tools in high-technology cockpits and are assuming increasing control of "cognitive" flight tasks, such as calculating fuel-efficient routes, navigating, or detecting and diagnosing system malfunctions and abnormalities. This study was designed to investigate automation bias, a recently documented factor in the use of automated aids and decision support systems. The term refers to omission and commission errors resulting from the use of automated cues as a heuristic replacement for vigilant information seeking and processing. Glass-cockpit pilots flew flight scenarios involving automation events or opportunities for automation-related omission and commission errors. Although experimentally manipulated accountability demands did not significantly impact performance, post hoc analyses revealed that those pilots who reported an internalized perception of "accountability" for their performance and strategies of interaction with the automation were significantly more likely to double-check automated functioning against other cues and less likely to commit errors than those who did not share this perception. Pilots were also likely to erroneously "remember" the presence of expected cues when describing their decision-making processes. C1 San Jose State Univ, Moffett Field, CA USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Illinois, Chicago, IL USA. Western Aerosp Labs, Moffett Field, CA USA. RP Mosier, KL (reprint author), San Francisco State Univ, Dept Psychol, 1600 Holloway, San Francisco, CA 94132 USA. OI Skitka, Linda/0000-0002-7078-0650 NR 24 TC 69 Z9 69 U1 4 U2 10 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 1050-8414 J9 INT J AVIAT PSYCHOL JI Int. J. Aviat. Psychol. PY 1998 VL 8 IS 1 BP 47 EP 63 DI 10.1207/s15327108ijap0801_3 PG 17 WC Psychology, Applied SC Psychology GA YT378 UT WOS:000071596400003 PM 11540946 ER PT J AU McGann, A Morrow, D Rodvold, M Mackintosh, MA AF McGann, A Morrow, D Rodvold, M Mackintosh, MA TI Mixed-media communication on the flight deck: A comparison of voice, data link, and mixed ATC environments SO INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY LA English DT Article AB A part-task simulation study compared pilots' responses to voice and data link air traffic control (ATC) messages in a single medium versus a mixed voice and data link ATC environment. Contrary to initial hypotheses, voice transaction times were longer in the mixed than in the single-medium environment, whereas data link transaction times were unaffected by the environment. The interval between ATC messages was also varied to examine the influence of time pressure in voice, data link, and mixed ATC environments. Time pressure resulting from short intervals between messages increased data link transaction times independent of environment, but message interval influenced voice communication only in the mixed environment. Closely spaced messages also increased the number of requests for clarification for voice messages and review menu use for data link messages. The findings emphasize the need to develop procedures for managing communication in mixed voice and data link environments and reinforce concerns about introducing data link into busy terminal environments with frequent communication. C1 San Jose State Univ, Ames Res Ctr, NASA, Moffett Field, CA 94035 USA. RP McGann, A (reprint author), San Jose State Univ, Ames Res Ctr, NASA, MS 262-4, Moffett Field, CA 94035 USA. OI Mackintosh, Margaret-Anne/0000-0002-2725-3177 NR 16 TC 11 Z9 12 U1 1 U2 1 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 1050-8414 J9 INT J AVIAT PSYCHOL JI Int. J. Aviat. Psychol. PY 1998 VL 8 IS 2 BP 137 EP 156 DI 10.1207/s15327108ijap0802_4 PG 20 WC Psychology, Applied SC Psychology GA ZW020 UT WOS:000074365600004 ER PT J AU Hou, LS Ravindran, SS AF Hou, LS Ravindran, SS TI Penalty methods for numerical approximations of optimal boundary flow control problems SO INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS LA English DT Article DE optimal flow control; incompressible flows; penalty methods ID NAVIER-STOKES EQUATIONS; FINITE-ELEMENT APPROXIMATION; BACKWARD-FACING STEP AB This article is concerned with penalty methods for solving optimal Dirichlet control problems governed by the steady-state and time-dependent Navier-Stokes equations. We present, in two different versions, the penalized methods for solving the steady-state Dirichlet control problems. These approaches are implemented and compared numerically. We also generalize the penalty methods to the time-dependent case, Semidiscrete and fully discrete approximations of time-dependent Dirichlet control problems are discussed and implemented. Numerical results for solving both the steady-state and the time dependent Dirichlet control problems are reported. C1 Iowa State Univ, Dept Math, Ames, IA 50011 USA. York Univ, Dept Math & Stat, N York, ON M3J 1P3, Canada. NASA, Langley Res Ctr, Flow Modeling & Control Branch, Hampton, VA 23681 USA. RP Hou, LS (reprint author), Iowa State Univ, Dept Math, Ames, IA 50011 USA. NR 14 TC 4 Z9 4 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1061-8562 J9 INT J COMPUT FLUID D JI Int. J. Comput. Fluid Dyn. PY 1998 VL 11 IS 1-2 BP 157 EP 167 PG 11 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 159BE UT WOS:000078151300009 ER PT J AU Bui, TT Mankbadi, RR AF Bui, TT Mankbadi, RR TI Numerical simulation of acoustic waves interacting with a shock wave in a quasi-1D convergent-divergent nozzle using an unstructured finite volume algorithm SO INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS LA English DT Article DE computational aeroacoustics; unstructured finite volume methods; Roe flux difference splitting; MacCormack time marching; nozzles AB Numerical simulations of a very small amplitude acoustic wave interacting with a shock wave in a quasi-1D convergent-divergent nozzle is performed using an unstructured finite volume algorithm with piece-wise linear, least square reconstruction, Roe flux difference splitting, and second-order MacCormack time marching. First, the spatial accuracy of the algorithm is evaluated for steady flows with and without the normal shock by running the simulation with a sequence of successively finer meshes. Then the accuracy of the Roe flux difference splitting near the sonic transition point is examined for different reconstruction schemes. Finally, the unsteady numerical solutions with the acoustic perturbation are presented and compared with linear theory results. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Bui, TT (reprint author), NASA, Lewis Res Ctr, MS 5-11,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 8 TC 3 Z9 3 U1 1 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1061-8562 J9 INT J COMPUT FLUID D JI Int. J. Comput. Fluid Dyn. PY 1998 VL 10 IS 4 BP 281 EP 289 DI 10.1080/10618569808961691 PG 9 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 151HE UT WOS:000077714000002 ER PT J AU Abdel-Tawab, K Rodin, GJ AF Abdel-Tawab, K Rodin, GJ TI Fracture size effects and polycrystalline inhomogeneity SO INTERNATIONAL JOURNAL OF FRACTURE LA English DT Article DE size effects; statistical effects; fracture toughness; brittle fracture; polycrystalline inhomogeneity ID SCB FRACTURE; ICE; MECHANICS; CREEP AB Fracture toughness testing is prone to exhibit various size effects that have to be understood in order to properly interpret the results. It is shown that the size effect associated with polycrystalline inhomogeneity is weak. Instead polycrystalline inhomogeneity induces statistical effects controlled by a small number of grains adjacent to the crack tip. C1 Univ Virginia, NASA, Langley Res Ctr, Ctr Adv Computat Technol, Hampton, VA 23681 USA. Univ Texas, Ctr Solids Struct & Mat, Austin, TX 78712 USA. RP Abdel-Tawab, K (reprint author), Univ Virginia, NASA, Langley Res Ctr, Ctr Adv Computat Technol, Hampton, VA 23681 USA. NR 29 TC 3 Z9 4 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0376-9429 J9 INT J FRACTURE JI Int. J. Fract. PY 1998 VL 93 IS 1-4 BP 247 EP 259 DI 10.1023/A:1007497112109 PG 13 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 235QD UT WOS:000082553300016 ER PT J AU Anicich, VG Sen, AD AF Anicich, VG Sen, AD TI Deuterium exchange in the systems of H2O+/H2O and H3O+/H2O SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE isotopic exchange; proton exchange; charge exchange; branching ratios; kinetics ID IONS AB The reactions of H2O+, H3O+, D2O+, and D3O+ with neutral H2O and D2O were studied by tandem mass spectrometry. The H2O+ and D2O+ ion reactions exhibited multiple channels, including charge transfer, proton transfer (or hydrogen atom abstraction), and isotopic exchange. The H3O+ and D3O+ ion reactions exhibited only isotope exchange. The variation in the abundances of all ions involved in the reactions was measured over a neutral pressure range from 0 to 2 x 10(-5) Ton. A reaction scheme was chosen, which consisted of a sequence of charge transfer, proton transfer, and isotopic exchange reactions, Exact solutions to two groups of simultaneous differential equations were determined; one group started with the reaction of ionized water, and the other group started with the reactions of protonated water. A nonlinear least-squares regression technique was used to determine the rate coefficients of the individual reactions in the schemes from the ion abundance data. Branching ratios and relative rate coefficients were also determined in this manner. A delta chi-squared analysis of the results of the model fitted to the experimental data indicated that the kinetic information about the primary isotopic exchange processes is statistically the most significant, The errors in the derived values of the kinetic information of subsequent channels increased rapidly, Data from previously published selected ion flow tube (SIFT) study were analyzed in the same manner, Rigorous statistical analysis showed that the statistical isotope scrambling model was unable to explain either the SIFT or the tandem mass spectrometry data. This study shows that statistical analysis can be utilized to assess the validity of possible models in explaining experimentally observed kinetic behaviors. Published by Elsevier Science B,V. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Anicich, VG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 183-301, Pasadena, CA 91109 USA. NR 17 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD JAN PY 1998 VL 172 IS 1-2 BP 1 EP 14 DI 10.1016/S0168-1176(97)00257-7 PG 14 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA ZB672 UT WOS:000072496000002 ER PT J AU Wang, RR Welsch, GE Castro-Cedeno, M AF Wang, RR Welsch, GE Castro-Cedeno, M TI Interfacial reactions of cast titanium with mold materials SO INTERNATIONAL JOURNAL OF PROSTHODONTICS LA English DT Article ID ALLOYS AB Purpose: Dental casting requires replication of complex shapes with high fidelity. To achieve this objective, the problem of scale formation on titanium dental castings must be overcome. Scaling occurs readily at high temperatures because of the high reactivity of molten titanium with investment materials. The purpose of this study was to examine the effectiveness of using stable oxide coatings on the mold surface to reduce the interfacial reactions. Materials and Methods: A traditional phosphate-bonded dental investment, a commercial titanium investment, and an experimental oxide coating were used for the molds. Pure titanium samples were cast, divested, and prepared for scanning electron microscopic and energy dispersive:ve x-ray spectroscopic analyses. Results: Layers of 7- to 10-mu m-thick scale were formed on titanium castings during reaction with traditional mold materials. Interface reaction was reduced between the molten titanium and the investment material when yttrium oxide or zirconium oxide coatings were applied to the mold before casting. Conclusion: Less titanium-mold interfacial reactions occurred when protective coatings were used as diffusion barriers for titanium casting. Y-2,O-3,-coating oxide particles applied without binder were entrapped in the cast titanium surface layer. Further study of a binder system for Y2O3 coating is needed. C1 Case Western Reserve Univ, Sch Dent, Dept Restorat Dent, Cleveland, OH 44106 USA. Case Western Reserve Univ, Sch Engn, Dept Mat Sci & Engn, Cleveland, OH 44106 USA. NASA, Lewis Res Ctr, Struct Syst Branch, Cleveland, OH 44135 USA. RP Wang, RR (reprint author), Case Western Reserve Univ, Sch Dent, Dept Restorat Dent, 10900 Euclid Ave, Cleveland, OH 44106 USA. EM rxw26@po.cwru.edu NR 25 TC 28 Z9 31 U1 0 U2 1 PU QUINTESSENCE PUBL CO INC PI CAROL STREAM PA 551 NORTH KIMBERLY DR, CAROL STREAM, IL 60188-1881 USA SN 0893-2174 J9 INT J PROSTHODONT JI Int. J. Prosthodont. PD JAN-FEB PY 1998 VL 11 IS 1 BP 33 EP 43 PG 11 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU892 UT WOS:000071766600005 PM 9588989 ER PT J AU Smith, AW Ramachandran, N AF Smith, AW Ramachandran, N TI Two-dimensional LDV measurements in the inlet and exit manifolds of a single stage oxidizer turbine SO INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES LA English DT Article AB Two-dimensional LDV measurements in the inlet and exit volute manifolds of a rocket turbine test model called the Oxidizer Technology Turbine Rig (OTTR), are discussed in this paper. It is a highly loaded single stage turbine, which uses inlet and exit volutes to provide optimum performance in a compact configuration. The system design creates high pressure and temperature gradients as well as high Mach number now. Detailed information on various aspects of LDV diagnostics such as the design and testing of a viable seeder and optical windows is provided followed by a discussion of the velocity and turbulence measurements made both in the inlet and exit volutes of the turbine. The measurements indicate that the inlet now is very uniform and with low turbulence levels. As it proceeds through the turbine, the flow turns and there is a substantial increase in the turbulence intensity. The measurements indicate that the turning characteristics of this volute/turbine configuration are more axial (tangential) dependent than radial. C1 NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. RP Smith, AW (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. NR 10 TC 0 Z9 0 U1 1 U2 1 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-0082 J9 INT J TURBO JET ENG JI Int. J. Turbo. Jet-Engines PY 1998 VL 15 IS 3 BP 175 EP 186 PG 12 WC Engineering, Aerospace SC Engineering GA 131TB UT WOS:000076590400003 ER PT J AU Dorney, DJ Sharma, OP Gundy-Burlet, KL AF Dorney, DJ Sharma, OP Gundy-Burlet, KL TI Physics of airfoil clocking in a high-speed axial compressor SO INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES LA English DT Article ID SIMULATIONS; FLOWS AB Axial compressors have inherently unsteady flow fields because of relative motion between rotor and stator airfoils. This relative motion leads to viscous and inviscid (potential) interactions between blade rows. As the number of stages increases in a turbomachine, the buildup of convected wakes can lead to progressively more complex wake/wake and wake/airfoil interactions. Variations in the relative circumferential positions of stators or rotors can change these interactions, leading to different unsteady forcing functions on airfoils and different compressor efficiencies. In addition, as the Mach number increases the interaction between blade rows can be intensified due to potential effects. In the current study an unsteady, quasi-three-dimensional Navier-Stokes analysis has been used to investigate the unsteady aerodynamics of stator clocking in a 1-1/2 stage compressor, typical of back stages used in high-pressure compressors of advanced commercial jet engines. The effects of turbulence have been modeled with both algebraic and two-equation models. The results presented include steady and unsteady surface pressures, efficiencies, boundary layer quantities and turbulence quantities. The main contribution of the current work: has been to show that airfoil clocking can produce significant performance variations at the Mach numbers associated with an engine operating environment In addition, the growth of turbulence has been quantified to aid in the development of models for the multi-stage steady analyses used in design systems. C1 GMI Engn & Management Inst, Flint, MI 48504 USA. Pratt & Whitney, E Hartford, CT USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Dorney, DJ (reprint author), GMI Engn & Management Inst, Flint, MI 48504 USA. NR 18 TC 11 Z9 13 U1 1 U2 1 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-0082 J9 INT J TURBO JET ENG JI Int. J. Turbo. Jet-Engines PY 1998 VL 15 IS 4 BP 259 EP 270 PG 12 WC Engineering, Aerospace SC Engineering GA 162YR UT WOS:000078375500003 ER PT S AU Waluschka, E AF Waluschka, E BE Gardner, LR Thompson, KP TI Polarization considerations SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1998 International Optical Design Conference CY JUN 08-12, 1998 CL KONA, HI SP OSA, Opt Soc Amer, SPIE Int Soc Opt Engn C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Waluschka, E (reprint author), NASA, Goddard Space Flight Ctr, 551, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2937-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3482 BP 140 EP 150 DI 10.1117/12.321998 PG 11 WC Optics SC Optics GA BL97D UT WOS:000077312500019 ER PT S AU Deslis, A Kurzweil, CG AF Deslis, A Kurzweil, CG BE Gardner, LR Thompson, KP TI Optical design of an imaging spectrometer utilizing an acousto-optic tunable filter as a disperser SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1998 International Optical Design Conference CY JUN 08-12, 1998 CL KONA, HI SP OSA, Opt Soc Amer, SPIE Int Soc Opt Engn AB Designing an imaging spectrometer using an AOTF can be a difficult task since there is no software that can simulate the bulk diffraction that takes place in the AOTF material. In this paper we will describe the method used to simulate the effects of the AOTF using a refractive grating halfway along the crystal. Apart from the zero order we also collect the +1 and -1 orthogonally polarized orders produced by the AOTF, gaining additional information that may be used in certain applications. The +1 and -1 order are imaged into the same focal plane, eliminating the need of a separate focal plane for each order and resulting in considerable savings in cost and mass. The whole system is achromatized from 1.2-2.4 microns using only two types of glass, one of which is BK7. The system has been designed, built, and tested. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91009 USA. RP Deslis, A (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91009 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2937-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3482 BP 170 EP 178 DI 10.1117/12.322002 PG 9 WC Optics SC Optics GA BL97D UT WOS:000077312500022 ER PT S AU Griffin, DVW AF Griffin, DVW BE Gardner, LR Thompson, KP TI Selection of optical glasses using Buchdahl's chromatic coordinate SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1998 International Optical Design Conference CY JUN 08-12, 1998 CL KONA, HI SP OSA, Opt Soc Amer, SPIE Int Soc Opt Engn C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Griffin, DVW (reprint author), NASA, Lewis Res Ctr, M-S 110-3,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2937-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3482 BP 356 EP 359 DI 10.1117/12.322023 PG 4 WC Optics SC Optics GA BL97D UT WOS:000077312500041 ER PT S AU Mouroulis, P AF Mouroulis, P BE Gardner, LR Thompson, KP TI Low-distortion imaging spectrometer designs utilizing convex gratings SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1998 International Optical Design Conference CY JUN 08-12, 1998 CL KONA, HI SP OSA, Opt Soc Amer, SPIE Int Soc Opt Engn AB Several designs are described that are based on the Offner concentric spectrometer form, with the grating formed on the convex secondary mirror. It is shown that these designs permit the reduction of spectral and spatial distortion to a small (similar to 1%) fi action of a pixel, while also providing a compact form with excellent optical correction. These designs can satisfy the needs and tight calibration requirements of imaging spectrometers for Earth remote sensing, over a broad spectral range from the ultraviolet to the thermal infrared. The practical realization of the designs owes much to the recent development of convex grating fabrication by electron-beam lithography. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mouroulis, P (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 0 TC 11 Z9 11 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2937-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3482 BP 594 EP 601 DI 10.1117/12.322062 PG 8 WC Optics SC Optics GA BL97D UT WOS:000077312500067 ER PT B AU Korsmeyer, DJ Walton, JD Aragon, C Shaykevich, A Chan, L AF Korsmeyer, DJ Walton, JD Aragon, C Shaykevich, A Chan, L BE Debnath, NC TI Experimental and computational data analysis in CHARLES and DARWIN SO INTERNATIONAL SOCIETY FOR COMPUTERS AND THEIR APPLICATIONS 13TH INTERNATIONAL CONFERENCE ON COMPUTERS AND THEIR APPLICATIONS LA English DT Proceedings Paper CT 13th International Conference on Computers and their Applications CY MAR 25-27, 1998 CL HONOLULU, HI SP Int Soc Comp & Applicat AB NASA Ames Research Center has developed several advanced distributed information systems to assist the distribution, analysis and management of data from experimental and numerical tests on aircraft wings and other aeronautical components. These systems provide immediate access to numerical aeronautics simulations and redefine the analysis operations for classic wind tunnel tests. The information systems built to make this possible are called CHARLES, enabling distributed access to computational fluid dynamic results, and DARWIN, which enables wind tunnel test results to be produced and made available to industry customers in near real time from active tests and from archival storage. This paper will provide details on data analysis with the DARWIN and CHARLES systems. C1 NASA, Ames Res Ctr, Computat Sci Div, Moffett Field, CA 94035 USA. RP Korsmeyer, DJ (reprint author), NASA, Ames Res Ctr, Computat Sci Div, MS 269-3, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INTERNATIONAL SOCIETY COMPUTER S & THEIR APPLICATIONS (ISCA) PI RALEIGH PA 8820 SIX FORKS ROAD, RALEIGH, NC 27615 USA BN 1-880843-23-4 PY 1998 BP 210 EP 213 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BK88A UT WOS:000073733700048 ER PT S AU Atkinson, CF Sager, JC Alazraki, M Loader, C AF Atkinson, CF Sager, JC Alazraki, M Loader, C BE Szmidt, RAK TI Composting in advanced life support systems SO INTERNATIONAL SYMPOSIUM ON COMPOSTING AND USE OF COMPOSTED MATERIALS FOR HORTICULTURE SE ACTA HORTICULTURAE LA English DT Proceedings Paper CT International Symposium on Composting and Use of Composted Materials for Horticulture CY APR 05-11, 1997 CL AYR, SCOTLAND SP S Ayrshire Council, Scottish Agr Coll, Scottish Off Agr, Environm and Fisheries Dept, Int Soc Hort Sci, Commiss Plant Substrates, Working Grp Composting Waste Mat, ARCO W Scotland, Bulrush Peat Co Ltd, Burns Cottage Trustees, CAB Int, Christiaens bv Horst, Cty Mushrooms, Evelyne Napias, Mkt Dept, Gannon UK Ltd, Gicom bv, Glasgow City Council, Grower Nexus Media Ltd, Int Soc Mushroom Sci, JCB Landpower Ltd, JBB plc, Marks & Spencer plc, ORCA, Universal Composting Corp Ltd, W Scotland Water, Wilkie Recycling Syst DE inedible crop residues; leachate; mineral recycling; Triticum aestivum L. cv. Apogee AB Space missions of extended duration are currently hampered by the prohibitive costs of external resupply. To reduce the need for resupply, the National Aeronautics and Space Administration (NASA) is currently testing methods to recycle solid wastes, water, and air. Composting can be an integral part of a biologically based waste treatment/recycling system. Results indicate that leachate from composted plant wastes is not inhibitory to seed germination and contains sufficient inorganic minerals to support plant growth. Other solid wastes, for example kitchen (food) wastes and human solid wastes, can be composted with inedible plant residues to safely reduce the volume of the wastes and levels of microorganisms potentially pathogenic to humans. Finished compost could serve as a medium for plant growth or mushroom production. C1 NASA, Kennedy Space Ctr, FL 32899 USA. RP Atkinson, CF (reprint author), NASA, Mail Code JJ-G, Kennedy Space Ctr, FL 32899 USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU INTERNATIONAL SOCIETY HORTICULTURAL SCIENCE PI LEUVEN 1 PA PO BOX 500, 3001 LEUVEN 1, BELGIUM SN 0567-7572 BN 90-6605-880-3 J9 ACTA HORTIC PY 1998 IS 469 BP 195 EP 201 PG 7 WC Agronomy; Horticulture SC Agriculture GA BL64V UT WOS:000076162400019 ER PT S AU Wheeler, RM Sager, JC Mackowiak, CL Stutte, GW Yorio, NC Ruffe, LM Berry, WL AF Wheeler, RM Sager, JC Mackowiak, CL Stutte, GW Yorio, NC Ruffe, LM Berry, WL BE Papadopoulos, AP TI Nutrient, acid and water budgets of hydroponically grown crops SO INTERNATIONAL SYMPOSIUM ON GROWING MEDIA AND HYDROPONICS, VOLS I AND II SE ACTA HORTICULTURAE LA English DT Proceedings Paper CT International Symposium on Growing Media and Hydroponics held with the Hydroponic-Society-of-America/American-Greenhouse-Vegetable-Growers-Asso ciation/CGVC Conference CY MAY 19-26, 1997 CL WINDSOR, CANADA SP Int Soc Hort Sci, Commiss Plant Subsrates, Working Grp Growing Media, Hydropon Soc Amer, Amer Greenhouse Vegetable Growers Assoc, Canadian Greenhouse Vegetable Crop, AAFC, Greenhouse & Proc Crops Res Ctr, Ontario Minist Agr & Food & Rural Affairs, Canadian Soc Hort Sci, Ontario Agri Food Res Fdn, Ontario Greenhouse Vegetable Producers Mkt Board, Canadian Sphagnum Peat Moss Assoc, Priva Comp Inc, Vineland Stn, Mastron, Leamington, Morse Growers Supplies, CF Ind Peod Inc, Leamington, Farm Credit Corp, Essex, Greenhouse Canada Magazine, Delhi, Royal Bank, Leamington, Colio Winery, Harrow, Canadian Imperial Bank Commerce, Performance Produce, Ruthven, Veg Gro Inc, Leamington, Victory Acres, Leamington, Seacliff Farms, Leamington, Entel Media, Amherstburg, Preney Print & Litho Inc, Windsor, Cleary Int Ctr, Windsor, Clifford Produce Co, Ruthven, Labbate Climate Control Syst Inc, Leamington, CEA Technol Int Inc, Alymer, Amco Produce, Leamington, Colassantis Trop Gardens, Ruthven, Derkach Farms, Ruthven, Doidge Business Machines, Windsor, Erie Sand & Gravel, Leamington, Erie James Ltd, Leamington, Flagship Farms Ltd, Leamington, Green Smackers Rx Farms Ltd, Kingsville, Southland Insurance, Leamington, Xerox Canada Ltd, Windsor, Growing Edge Magazine, Corvallis, Amer Vegetable Growers, Flowers Canada Inc, Ontario, Pract Hydropon & Greenhouses Magazine, Australia, Erie Shores Growers Ltd, Ruthven DE wheat; Triticum aestivum; potato; Solanum tuberosum; lettuce; Lactuca sativa; soybean; Glycine max AB Tests were conducted with wheat, soybean, potato, and lettuce to evaluate their nutrient, acid, and water requirements when grown in a recirculating hydroponic system. Crops were grown in an atmospherically closed chamber (20 m(2) area, 113 m(3) volume) using recirculating nutrient film technique (NFT). Nutrient solutions used nitrate as the sole nitrogen source and were maintained at an electrical conductivity (EC) set-point of 0.12 S m(-1). Solution pH was maintained near 5.8 with automatic additions of dilute (0.4 mol L-1) nitric acid. Depending on the species, radiation conversion efficiencies ranged from 0.4 to 0.6 g dry mass (DM) mol(-1) of applied PAR, water use efficiency ranged from 3 to 8 g DM L-1, nutrient use (total K, Ca, Mg) efficiency ranged from 0.4 to 0.6 g DM mol(-1) cations added, and acid use (for pH control) efficiency ranged from 0.8 to 1.5 g DM mol(-1) H+ added. Biomass production, nutrient uptake, and acid use for all crops (except nutrient use in potatoes when tuber yield was low and vegetative growth was high) showed linear relationships with applied PAR, suggesting that these factors should be predictable on the basis of PAR. Because water vapor pressure deficits varied between studies, water use showed no direct relationship to PAR. C1 NASA, Kennedy Space Ctr, Biomed Off, Kennedy Space Ctr, FL 32899 USA. RP Wheeler, RM (reprint author), NASA, Kennedy Space Ctr, Biomed Off, Kennedy Space Ctr, FL 32899 USA. NR 17 TC 0 Z9 0 U1 1 U2 5 PU INTERNATIONAL SOCIETY HORTICULTURAL SCIENCE PI LEUVEN 1 PA PO BOX 500, 3001 LEUVEN 1, BELGIUM SN 0567-7572 BN 90-6605-811-0 J9 ACTA HORTIC PY 1998 IS 481 BP 655 EP 661 PN 1&2 PG 7 WC Agronomy; Horticulture SC Agriculture GA BN03S UT WOS:000080469700078 ER PT B AU Bandara, S Gunapala, S Liu, J Mumolo, J Luong, E Hong, W Sengupta, D AF Bandara, S Gunapala, S Liu, J Mumolo, J Luong, E Hong, W Sengupta, D BE Li, SS Su, YK TI Quantum well infrared photodetectors: Device physics and light coupling SO INTERSUBBAND TRANSITIONS IN QUANTUM WELLS: PHYSICS AND DEVICES LA English DT Proceedings Paper CT International Workshop on Intersubband Transitions in Quantum Wells - Physics and Applications CY DEC 15-18, 1997 CL NATL CHENG KUNG UNIV, TAINAN, TAIWAN SP Natl Sci Council & Minist Educ, Off Naval Res-Asia, US Army Res Off-Far E HO NATL CHENG KUNG UNIV DE quantum well; intersubband; infrared detectors; broad-band; gratings ID DARK CURRENT; PERFORMANCE; WAVELENGTH; GRATINGS C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Bandara, S (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBLISHERS PI NORWELL PA 101 PHILIP DRIVE, ASSINIPPI PARK, NORWELL, MA 02061 USA BN 0-7923-8164-5 PY 1998 BP 43 EP 49 PG 7 WC Optics; Physics, Applied; Physics, Multidisciplinary SC Optics; Physics GA BN28B UT WOS:000081415100007 ER PT B AU Gunapala, SD Bandara, SV Liu, JK Hong, W Sundaram, M Maker, PD Muller, RE Shott, CA Carralejo, R AF Gunapala, SD Bandara, SV Liu, JK Hong, W Sundaram, M Maker, PD Muller, RE Shott, CA Carralejo, R BE Li, SS Su, YK TI 9 micron cutoff 640 x 486 GaAs/AlxGa1-xAs quantum well infrared photodetector snap-shot camera SO INTERSUBBAND TRANSITIONS IN QUANTUM WELLS: PHYSICS AND DEVICES LA English DT Proceedings Paper CT International Workshop on Intersubband Transitions in Quantum Wells - Physics and Applications CY DEC 15-18, 1997 CL NATL CHENG KUNG UNIV, TAINAN, TAIWAN SP Natl Sci Council & Minist Educ, Off Naval Res-Asia, US Army Res Off-Far E HO NATL CHENG KUNG UNIV ID FOCAL-PLANE ARRAY AB A 9 mu m cutoff 640 x 486 snap-shot quantum well infrared photodetector (QWIP) camera has been demonstrated. The performance of this QWIP camera is reported including indoor and outdoor imaging. Excellent imagery, with a noise equivalent differential temperature (NE Delta T) of 36 mK has been achieved at 300 K background. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Gunapala, SD (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 9 TC 4 Z9 4 U1 0 U2 0 PU KLUWER ACADEMIC PUBLISHERS PI NORWELL PA 101 PHILIP DRIVE, ASSINIPPI PARK, NORWELL, MA 02061 USA BN 0-7923-8164-5 PY 1998 BP 193 EP 198 PG 6 WC Optics; Physics, Applied; Physics, Multidisciplinary SC Optics; Physics GA BN28B UT WOS:000081415100029 ER PT S AU Ueno, T Ballard, RE Shuer, LM Cantrell, JH Yost, WT Hargens, AR AF Ueno, T Ballard, RE Shuer, LM Cantrell, JH Yost, WT Hargens, AR BE Marmarou, A Bullock, R Avezaat, C Baethmann, A Becker, D Brock, M Hoff, J Nagai, H Reulen, HJ Teasdale, G TI Noninvasive measurement of pulsatile intracranial pressure using ultrasound SO INTRACRANIAL PRESSURE AND NEUROMONITORING IN BRAIN INJURY SE ACTA NEUROCHIRURGICA SUPPLEMENTA LA English DT Proceedings Paper CT 10th International ICP Symposium CY MAY 25-29, 1997 CL WILLIAMSBURG, VA DE cerebrovascular circulation; intracranial pressure; noninvasive measurement AB The present study was designed to validate our noninvasive ultrasonic technique (pulse phase locked loop: PPLL) for measuring intracranial pressure (ICP) waveforms. The technique is based upon detecting skull movements which are known to occur in conjunction with altered intracranial pressure. In bench model studies, PPLL output was highly correlated with changes in the distance between a transducer and a reflecting target (R-2 = 0.977). In cadaver studies, transcranial distance was measured while pulsations of ICP (amplitudes of zero to 10 mm Hg) were generated by rhythmic injections of saline. Frequency analyses (fast Fourier transformation) clearly demonstrate the correspondence between the PPLL output and ICP pulse cycles. Although theoretically there is a slight possibility that changes in the PPLL output are caused by changes in the ultrasonic velocity of brain tissue, the decreased amplitudes of the PPLL output as the external compression of the head was increased indicates that the PPLL output represents substantial skull movement associated with altered ICP. In conclusion, the ultrasound device has sufficient sensitivity to detect transcranial pulsations which occur in association with the cardiac cycle. Our technique makes it possible to analyze ICP waveforms noninvasively and will be helpful for understanding intracranial compliance and cerebrovascular circulation. C1 NASA, Ames Res Ctr, Gravitat Res Branch 23911, Stanford, CA 94305 USA. RP Hargens, AR (reprint author), NASA, Ames Res Ctr, Gravitat Res Branch 23911, Stanford, CA 94305 USA. NR 0 TC 19 Z9 19 U1 1 U2 4 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, A-1201 VIENNA, AUSTRIA SN 0065-1419 BN 3-211-83094-4 J9 ACT NEUR S JI Acta Neurochir. Suppl. PY 1998 VL 71 BP 66 EP 69 PG 4 WC Emergency Medicine; Clinical Neurology SC Emergency Medicine; Neurosciences & Neurology GA BL58B UT WOS:000075927500021 PM 9779147 ER PT J AU Jenkins, DG Atkinson, CF Garland, JL AF Jenkins, DG Atkinson, CF Garland, JL TI A cautionary note on measuring protistan bacterivory by acid lysozyme SO INVERTEBRATE BIOLOGY LA English DT Article ID PROTOZOAN BACTERIVORY; DIGESTIVE ENZYMES; LABELED BACTERIA; FOOD WEBS; WATER; FRESH AB Protistan bacterivory is considered important in aquatic ecosystems but difficult to measure. Two recently proposed enzymatic assays of protistan bacterivory rely on lysozyme :hydrolysis of the beta(1-4) glycosidic bond between N-acetylglucosamine and the fluorogenic compound 4-methylumbelliferyl. We analyzed protists and metazoans for acid-lysozyme (L-ACID), and found that 5 of 6 protists and 20 of 21 (95%) metazoan genera had L-ACID. Protistan bacterivory estimates based on L-ACID activity may be erroneous if micrometazoans are in analyzed samples, as is likely in benthic and littoral samples and without careful sample processing. In addition, lysozymes (e.g., L-ACID, beta-N-acetylglucosaminidase) hydrolyze both peptidoglycan and chitin, meaning that bacterivory may not be distinguished from chitin digestion by lysozyme analyses. Therefore, lysozyme-based analyses of bacterivory should be applied only to samples that do not contain chitinous organisms, and perhaps predators of chitinous organisms. Finally, dissolved organic compounds interfered with fluorometric analysis of enzymatic substrate hydrolysis,: leading to an underestimate of L-ACID activity. Lysozyme-based analyses of protistan bacterivory developed for use on pelagic samples will be difficult to apply to some inland waters and benthic or littoral samples without precautions to exclude metazoans, chitinolytic enzymes in organisms, and dissolved organic compounds. C1 Univ Illinois, Dept Biol, Springfield, IL 62794 USA. NASA, Kennedy Space Ctr, FL 32899 USA. Dynamac Corp, Kennedy Space Ctr, FL 32899 USA. RP Jenkins, DG (reprint author), Univ Illinois, Dept Biol, POB 19243, Springfield, IL 62794 USA. OI Jenkins, David/0000-0002-0363-2260 NR 20 TC 1 Z9 1 U1 0 U2 2 PU AMER MICROSCOPICAL SOC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 USA SN 1077-8306 J9 INVERTEBR BIOL JI Invertebr. Biol. PY 1998 VL 117 IS 3 BP 181 EP 185 DI 10.2307/3226983 PG 5 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 115RQ UT WOS:000075679400001 ER PT B AU Cane, HV AF Cane, HV BE Potgieter, MS Raubenheimer, BC vanderWalt, DJ TI Energetic particles in the solar wind: Propagation, acceleration, and modulation SO INVITED, RAPPORTEUR, AND HIGHLIGHT PAPERS OF THE 25TH INTERNATIONAL COSMIC RAY CONFERENCE, VOL 8 LA English DT Proceedings Paper CT 25th International Cosmic Ray Conference CY JUL 30-AUG 06, 1997 CL DURBAN, SOUTH AFRICA SP Int Union Pure & Appl Phys, SA Fdn Red Dev, Potchefstroom Univ Christian Higher Educ, Dept Phys, Space Res Unit, De Beers Corp, Chairmans Fund Anglo Amer, SA Airways, Durban Metropolitan Council, SA Tourism Corp, Stellenbosch Farmers Winery AB This paper reviews the work presented at the XXV International Cosmic Ray Conference under the headings "Transport and Transient Phenomena in the Heliosphere" (SH2, SH3). Such research investigates the behaviour of solar particles and galactic cosmic rays in response to solar wind variations with timescales up to the order of days. Long term modulation forms part of SH4. The papers in the main discussed aspects of particle propagation, particle responses to corotating interaction regions and particle responses to coronal mass ejections and their associated shocks formed in the interplanetary medium. Most results referred to locations within 5 AU of the Sun. Although no dramatically new results were presented, continuous progress has been made. Topics of particular interest included 1) the role of perpendicular diffusion in explaining the Ulysses high latitude results, 2) comparisons between theory and observation in deriving diffusion coefficients and 3) the adequacy of diffusive shock acceleration to explain observations above about 10 MeV. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Cane, HV (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3324-8 PY 1998 BP 135 EP 150 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL57T UT WOS:000075923000008 ER PT B AU von Rosenvinge, TT AF von Rosenvinge, TT BE Potgieter, MS Raubenheimer, BC vanderWalt, DJ TI Low energy cosmic rays: Their composition and nuclear cross sections SO INVITED, RAPPORTEUR, AND HIGHLIGHT PAPERS OF THE 25TH INTERNATIONAL COSMIC RAY CONFERENCE, VOL 8 LA English DT Proceedings Paper CT 25th International Cosmic Ray Conference CY JUL 30-AUG 06, 1997 CL DURBAN, SOUTH AFRICA SP Int Union Pure & Appl Phys, SA Fdn Red Dev, Potchefstroom Univ Christian Higher Educ, Dept Phys, Space Res Unit, De Beers Corp, Chairmans Fund Anglo Amer, SA Airways, Durban Metropolitan Council, SA Tourism Corp, Stellenbosch Farmers Winery AB This rapporteur report provides a summary of papers primarily concerning experimental observations of low energy cosmic rays and their nuclear cross sections which were presented at the 25(th) International Cosmic Ray Conference in Durban, South Africa, 30 July - 6 August, 1997. Results are summarized for isotopic abundances as well as for electrons, positrons, and antiprotons. Accurate nuclear cross sections are vital for the correct interpretation of the cosmic ray observations, and recent progress in measuring cross sections is also presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP von Rosenvinge, TT (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3324-8 PY 1998 BP 237 EP 256 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL57T UT WOS:000075923000013 ER PT S AU Radicella, SM Bilitza, D Reinisch, BW Adeniyi, JO Gonzalez, MEM Zolesi, B Zhang, ML Zhang, SR AF Radicella, SM Bilitza, D Reinisch, BW Adeniyi, JO Gonzalez, MEM Zolesi, B Zhang, ML Zhang, SR BE Rawer, K Bradley, PA TI IRI Task Force Activity at ICTP: Proposed improvements for the IRI region below the F peak SO IRI 1997 SYMPOSIUM: NEW DEVELOPMENTS IN IONOSPHERIC MODELLING AN D PREDICTION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT IRI Symposium on New Developments in Ionospheric Modelling and Prediction CY MAY 27-30, 1997 CL KUHLUNGSBORN, GERMANY SP Comm Space Res AB The Aeronomy and Radiopropagation Laboratory of the International Center for Theoretical Physics (ICTP) in Trieste, Italy has hosted special IRI Task Force Activities (TFAs) annually since 1994. This article reviews the format and results of the 1994, 1995, and 1996 TFAs. The prime focus of these TFAs has been the Fl region and the bottomside F2 region. Each meeting has tackled a specific subset of modeling problems using morning round-table discussions and afternoon computer sessions to solve the 'problem of the day'. Data, models and related software were provided by the participants on electronic media or were retrieved over the internet. As a result of this effort several improvements have been proposed for the IRI description of the region below the F2 peak: (1) A more accurate description of the probability of the existence of the Fl layer, (2) A more realistic description of the bottomside thickness parameters, (3) A set of new anchor points to define the intermediate region between the E valley top and the bottomside F2 region. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 ICTP, Aeron & Radiopropagat Lab, I-34100 Trieste, Italy. NSSDC, Goddard Space Flight Ctr, Code 633 Hughes STX, Greenbelt, MD 20771 USA. Univ Massachusetts, Ctr Atmospher Res, Lowell, MA 01854 USA. Univ Ilorin, Dept Phys, Ilorin, Nigeria. CASLEO, San Juan, Argentina. Ist Nazl Geofis, I-00143 Rome, Italy. Acad Sinica, Wuhan Inst Phys, Wuhan 430071, Peoples R China. RP Radicella, SM (reprint author), ICTP, Aeron & Radiopropagat Lab, I-34100 Trieste, Italy. RI Zhang, Shun-Rong/G-7593-2015 OI Zhang, Shun-Rong/0000-0002-1946-3166 NR 10 TC 14 Z9 14 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043470-3 J9 ADV SPACE RES PY 1998 VL 22 IS 6 BP 731 EP 739 DI 10.1016/S0273-1177(98)00091-X PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL85H UT WOS:000076930000002 ER PT S AU Bilitza, D Koblinsky, C Williamson, R Bhardwaj, S AF Bilitza, D Koblinsky, C Williamson, R Bhardwaj, S BE Rawer, K Bradley, PA TI Improving the topside electron density model for IRI SO IRI 1997 SYMPOSIUM: NEW DEVELOPMENTS IN IONOSPHERIC MODELLING AN D PREDICTION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT IRI Symposium on New Developments in Ionospheric Modelling and Prediction CY MAY 27-30, 1997 CL KUHLUNGSBORN, GERMANY SP Comm Space Res AB We are investigating potential improvements of the IRI topside model using a large data base of topside electron density profiles (more than 100 000 profiles) obtained with the Alouette and ISIS spacecraft from 1965 to 1980. Our modeling approach is based on elements of the older BENT model and of the current IRI topside model. We divide the topside profile into 4 segments reaching up to 3500 km compared to the 3 segments and the upper limit of 1000 km used in the BENT model. Compared to the fixed segment boundaries used in BENT and IRI we use dynamic segment boundaries. In each segment we assume a linearly varying density gradient whereas the BENT model takes a constant gradient. The global and temporal variations of the segment parameters are described in terms of geomagnetic latitude, solar sunspot number and foF2 in a manner similar to the current IRI method. Comparisons with TOPEX total electron data document the dramatic improvements obtained with this new model approach. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 NSSDC, Goddard Space Flight Ctr, Code 633 HSTX, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Hughes STX, Greenbelt, MD 20770 USA. RP Bilitza, D (reprint author), NSSDC, Goddard Space Flight Ctr, Code 633 HSTX, Greenbelt, MD 20771 USA. NR 16 TC 11 Z9 11 U1 1 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043470-3 J9 ADV SPACE RES PY 1998 VL 22 IS 6 BP 777 EP 787 DI 10.1016/S0273-1177(98)00098-2 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL85H UT WOS:000076930000009 ER PT S AU Grebowsky, JM Erlandson, RE Sojka, JJ Schunk, RW Bilitza, D AF Grebowsky, JM Erlandson, RE Sojka, JJ Schunk, RW Bilitza, D BE Rawer, K Bradley, PA TI Comparison of measured high latitude F-region ion composition climatological variability with models SO IRI 1997 SYMPOSIUM: NEW DEVELOPMENTS IN IONOSPHERIC MODELLING AN D PREDICTION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT IRI Symposium on New Developments in Ionospheric Modelling and Prediction CY MAY 27-30, 1997 CL KUHLUNGSBORN, GERMANY SP Comm Space Res AB Satellite measurements of the global F-region ion composition morphology, due: to orbit-to-orbit variations in space and time, are most effectively examined statistically, taking into consideration the ranges of variability in the data. Simple averages of the measurements do not clearly delineate narrow and time varying features such as density troughs/holes, sharp ionospheric layers, or even auroral region enhancements of electron temperature/molecular ion concentrations. These in fact are the most prominent features seen along individual satellite passes and are features which have prominent climatological variations To explore how well current ionosphere models fare with reality at middle and high latitudes, the entire ensemble of available solar minimum satellite ion composition measurements (predominantly from Atmosphere Explorer C and D) are sorted into spatial, temporal and magnetic/solar activity indices bins. Ion concentrations obtained from multiple runs of the International Reference Ionosphere (IRI) and the Utah State University Time Dependent Ionosphere model (TDIM), sorted into bins similar to those used for the satellite data sets are compared to the measurements. As currently configured the IRI model does not make a good match with the middle and high latitude topside ionosphere ion composition measurements. The TDIM is a better match to the measurements but does not reproduce the deepest high latitude ionospheric troughs and auroral-cusp molecular ion enhancements. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Utah State Univ, Ctr Atmospher & Space Sci, Logan, UT 84322 USA. NASA, Goddard Space Flight Ctr, Hughes STX Corp, Greenbelt, MD 20771 USA. RP Grebowsky, JM (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RI Grebowsky, Joseph/I-7185-2013; Erlandson, Robert/G-2767-2015 NR 10 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043470-3 J9 ADV SPACE RES PY 1998 VL 22 IS 6 BP 885 EP 894 DI 10.1016/S0273-1177(98)00118-5 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL85H UT WOS:000076930000029 ER PT B AU Johnson, AE AF Johnson, AE GP IEEE IEEE TI 2-D patterns for 3-D surface matching SO ISCAS '98 - PROCEEDINGS OF THE 1998 INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1-6 LA English DT Proceedings Paper CT IEEE International Symposium on Circuits and Systems (ISCAS 98) CY MAY 31-JUN 03, 1998 CL MONTEREY, CA SP IEEE, Naval Postgraduate Sch, Monterey, Calif AB Surface matching is the process that compares the shape of two surfaces. To facilitate surface matching, we have developed a 2-D representation for comparing 3-D surfaces of arbitrary shape. Using a cylindrical mapping, a descriptive pose-invariant 2-D pattern is created for every point on the surface of an object. By comparing patterns, point correspondences between different surfaces are established. When a sufficient number of point correspondences exist between two surfaces, the surfaces match. We show that the simplicity and generality of our representation makes it widely applicable to problems in 3-D computer vision including object modeling, interior modeling and object recognition. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Johnson, AE (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4455-3 PY 1998 BP D506 EP D509 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BL35E UT WOS:000075224600717 ER PT S AU Dayton, JA AF Dayton, JA GP IEEE IEEE IEEE TI A review of the suppression of secondary electron emission from the electrodes of multistage collectors SO ISDEIV: XVIIITH INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM - PROCEEDINGS, VOLS 1 AND 2 SE PROCEEDINGS - INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM LA English DT Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL AB A review is presented of more than 20 years of research conducted at NASA Lewis Research Center on the suppression of secondary electron emission (SEE) for the enhancement of the efficiency of vacuum electron devices with multistage depressed collectors. This paper will include a description of measurement techniques, data from measurements of SEE on a variety of materials of engineering interest and methods of surface treatment for the suppression of SEE. In the course of this work the lowest secondary electron yield ever reported was achieved for ion textured graphite, and, in a parallel line of research, the highest yield was obtained for chemical vapor deposited thin diamond films. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Dayton, JA (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1093-2941 BN 0-7803-3953-3 J9 P INT SYMP DISCH EL PY 1998 VL 18 BP 9 EP 15 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA BM06E UT WOS:000077494100002 ER PT S AU Vayner, BV Ferguson, DC Galofaro, JT AF Vayner, BV Ferguson, DC Galofaro, JT GP IEEE IEEE IEEE TI The spasecraft surfaces degradation and contamination caused by arcing in low density plasmas SO ISDEIV: XVIIITH INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM - PROCEEDINGS, VOLS 1 AND 2 SE PROCEEDINGS - INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM LA English DT Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL AB Previous experience has shown that some surfaces of large spacecraft may have a high negative potential relatively the surrounding plasma. When this potential reaches a few hundred volts, electrical discharges (arcs) occur on the surface. One of the adverse consequences of arcing is the degradation of the thermal insulation and the contamination of local environment. To prevent the negative influence of these processes on the operation of spacecraft systems and scientific equipment, it seems necessary to determine the rate of degradation and plasma contamination vs. are rate, amplitude of current, and the duration of are. This report describes the results of experiments that have been done to study the rate of coating degradation, atomic composition of the material injected into the plasma, and the spatial distribution of the contaminating material. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Vayner, BV (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1093-2941 BN 0-7803-3953-3 J9 P INT SYMP DISCH EL PY 1998 VL 18 BP 824 EP 827 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA BM06E UT WOS:000077494100190 ER PT B AU Chiu, HY AF Chiu, HY BE Hsu, JP Hsu, L TI Modern cosmology SO JINGSHIN THEORETICAL PHYSICS SYMPOSIUM IN HONOR OF PROFESSOR TA-YOU WU LA English DT Proceedings Paper CT JingShin Theoretical Physics Symposium in Honor of Professor Ta-You Wu CY SEP, 1997 CL UNIV MASSACHUSETTS, DARTMOUTH, MA SP Jing Shin Res Fund, Univ Massachusetts, Dept Phys, Potz Sci Fund HO UNIV MASSACHUSETTS AB In this paper we review the current status of cosmological theory. First a brief discussion of Friedmann model and classical observations is presented. Next the events of the early Universe from a fraction of a second to the pressent are discussed from the point of view of high temperature thermodynamics. The most important phenomena in this phase are pair creation of particles and nuclear equilibrium at temperatures 10(9)K and above. When the temperature drops, nuclear equilibrium will freeze out, resulting in the synthesis of helium and some light elements. Likewise pairs of particles will annihilate at lower temperatures but some relic particles may remain intact today. So far the theory seems to be on solid ground. However, there are many unanswered questions which force one to make certain drastic assumptions, such as the existence of dark (invisible) matter. One is also forced to retrace the evolution of the Universe back in time to 10(-36) second, during which quantum effects of gravity become important. This then leads to the Inflationary Theory. This theory is still under development. Scanty data exist to support or to refute the theory. The origin of our Universe - the ultimate frontier in astrophysics and a Pandora Box - is now open for exploration. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Chiu, HY (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3372-8 PY 1998 BP 379 EP 389 PG 11 WC Physics, Atomic, Molecular & Chemical; Physics, Multidisciplinary; Physics, Condensed Matter; Physics, Particles & Fields; Physics, Mathematical SC Physics GA BL71B UT WOS:000076417900026 ER PT J AU Olivas, JD Bolin, S AF Olivas, JD Bolin, S TI Advancements in MEMS materials and processing technology SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID ACTUATORS; SYSTEMS; SENSOR AB From achievements in display imaging to air bag deployment, microelectromechanical systems are becoming more commonplace in everyday life. With an abundance of opportunities for innovative R&D in the field, the research trends are not only directed toward novel sensor and actuator development, but also toward further miniaturization, specifically achieving micro- and nanoscaled integrated systems. R&D efforts in space, military, and commercial applications are directing specific research programs focused on the area of materials science as enabling technology to be exploited by researchers and to further push the envelope of micrometer-scaled device technology. These endeavors are making significant progress in bringing this aspect of the microelectro-mechanical field to maturation through advances in materials and processing technologies. C1 CALTECH, Jet Prop Lab, Adv Interconnect & Mfg Assurance Program, Pasadena, CA 91101 USA. RP Olivas, JD (reprint author), CALTECH, Jet Prop Lab, Adv Interconnect & Mfg Assurance Program, 4800 Oak Grove Dr,Mail Stop 125-161, Pasadena, CA 91101 USA. NR 32 TC 12 Z9 12 U1 1 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD JAN PY 1998 VL 50 IS 1 BP 38 EP 43 DI 10.1007/s11837-998-0066-3 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA YR053 UT WOS:000071453000008 ER PT J AU Chamis, CC Gotsis, PK Minnetyan, L AF Chamis, CC Gotsis, PK Minnetyan, L TI Progressive fracture and damage tolerance of composite pressure vessels SO JOURNAL OF ADVANCED MATERIALS LA English DT Article AB Structural performance (integrity, durability and damage tolerance) of fiber reinforced composite pressure vessels, designed for pressured shelters for planetary exploration, is investigated via computational simulation. An integrated computer code is utilized for the simulation of damage initiation, growth, and propagation under pressure. Aramid fibers are considered in a rubbery polymer matrix for the composite system. Effects of fiber orientation and fabrication defect/accidental damages are investigated with regard to the safety and durability of the shelter Results show the viability of fiber reinforced pressure vessels as damage tolerant shelters for planetary colonization. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Clarkson Univ, Potsdam, NY USA. RP Chamis, CC (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 17 TC 2 Z9 3 U1 0 U2 0 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 1070-9789 J9 J ADV MATER JI J. Adv. Mater. PD JAN PY 1998 VL 30 IS 1 BP 22 EP 26 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 130FJ UT WOS:000076509000004 ER PT J AU Bowles, KJ McCorkle, L Ingrahm, L AF Bowles, KJ McCorkle, L Ingrahm, L TI Comparison of graphite fabric reinforced PMR-15 and Avimid N composites after long-term isothermal aging at various temperatures SO JOURNAL OF ADVANCED MATERIALS LA English DT Article ID RESIN AB Extensive effort is currently being expended to demonstrate the feasibility of using high performance, polymer matrix composites as engine structural materials over the expected operating lifetime of the aircraft, which can extend from 18,000 to 30,000 hr: To accomplish this goal, it is necessary to pursue the development of thermal and mechanical durability models for graphite fiber reinforced, polymer matrix composites. Numerous investigations have been reported regarding the thermo-oxidative stability (TOS) of the the polyimide PMR-15. It is yet to be determined if the information obtained from the PMR-15 composite tears is applicable to other polymer matrix composites. The condensation curing polymer Avimid N is another advanced composite material often considered for structural applications at high temperatures. Avimid N is reported to have better thermo-oxidative stability (TOS) than PMR-15, brit the latter is more easily processed. The purposes of the work described herein one to compare the thermal aging behavior of these two matrix polymers and to determine the reasons for and the consequences of differences in thermal durability Differences were observed in weight loss time data, microstructural changes, and compression properties after aging at temperatures of 204, 260, 288, 316, and 343 degrees C. Of special interest were the differences in surface thermal and oxidative damage, and also the extent of internal cracking. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Gilcrest Corp, Cleveland, OH USA. RP Bowles, KJ (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 13 TC 5 Z9 5 U1 1 U2 1 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 1070-9789 J9 J ADV MATER JI J. Adv. Mater. PD JAN PY 1998 VL 30 IS 1 BP 27 EP 35 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 130FJ UT WOS:000076509000005 ER PT J AU Nguyen, K AF Nguyen, K TI Active control of helicopter blade stall SO JOURNAL OF AIRCRAFT LA English DT Article ID HIGHER HARMONIC CONTROL AB This paper describes the numerical analysis of an automatic stall suppression system for helicopters, The analysis employs a finite element method and includes unsteady aerodynamic effects (dynamic stall) and a nonuniform inflow model, The stall suppression system, based on a transfer matrix approach, uses blade root actuation to suppress stall directly, The results show that stall can effectively be suppressed using higher harmonic blade root pitch at both cruise and high-speed Eight conditions. The control amplitude was small, less than 1 deg, In a high-thrust, low-speed flight condition, stall is fairly insensitive to higher harmonic inputs. In general, stall suppression does not guarantee performance improvements, The results also show the distinction between stall suppression and performance improvement with active control. When the controller aims to reduce the shaft torque, rotor performance improvement can be achieved with a small degradation in stall behavior. C1 NASA, Ames Res Ctr, Rotorcraft Aeromech Branch, Moffett Field, CA 94035 USA. RP Nguyen, K (reprint author), NASA, Ames Res Ctr, Rotorcraft Aeromech Branch, Moffett Field, CA 94035 USA. NR 17 TC 12 Z9 13 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 1998 VL 35 IS 1 BP 91 EP 98 DI 10.2514/2.2264 PG 8 WC Engineering, Aerospace SC Engineering GA YV907 UT WOS:000071876300014 ER PT J AU Tindell, RH Marconi, F Kalkhoran, I Yetter, J AF Tindell, RH Marconi, F Kalkhoran, I Yetter, J TI Deflection of turbofan exhaust streams for enhanced engine/nacelle integration SO JOURNAL OF AIRCRAFT LA English DT Article AB An analytical and experimental description of how the fan exhaust of a modern turbofan can he deflected into an annular cascade using only rare bleed flow is presented. Thrust reversing, emphasized herein, and/or vectoring is achieved without the need for fan duct blockers or other hardware devices to turn the flow, allowing lighter, less complex, and lower loss exhaust systems for more efficient up-and-away. flight. Two approaches for deflecting fan flow into an annular cascade, using two different models, are described, and test results are discussed. Results of a Euler analysis and its critical relationship with the testing are also described, Both methods use injected core now to turn the fan flow. One method uses an annular air-curtain emanating from an annular injection slot located opposite the cascade and the other uses a similar slot in the nozzle throat to force upstream flows into the cascade. Both approaches are impacted by engine core bleed limits. Injector jet arrangements to meet this requirement while providing adequate reverse thrust are described; analyses and test results are reviewed. C1 Northrop Grumman Corp, Bethpage, NY 11714 USA. Polytech Univ, Farmingdale, NY 11735 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Tindell, RH (reprint author), Northrop Grumman Corp, Bethpage, NY 11714 USA. NR 5 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 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 1998 VL 35 IS 1 BP 106 EP 112 DI 10.2514/2.2266 PG 7 WC Engineering, Aerospace SC Engineering GA YV907 UT WOS:000071876300016 ER PT J AU Dobson, JEF McClure, FD Rainosek, AP AF Dobson, JEF McClure, FD Rainosek, AP TI A precollaborative study of weight determination methods for quick frozen shrimp SO JOURNAL OF AOAC INTERNATIONAL LA English DT Article AB A precollaborative study compared the accuracy and precision of official AOAC methods with other selected methods for determining net weight of IQF-glazed shrimp and block-glazed shrimp, assessed the ruggedness of the methods with respect to changes in the levels of the factors under study, and selected candidate methods for use in a collaborative study. Methods tested for determining deglazed (frozen) net weight of IQF-glazed shrimp were (1) AOAC Method 963.18 and (2) the Water Bath Dip Method. Methods tested for determining thawed net weight of IQF-glazed shrimp were (1) AOAC Method 967.13, (2) Modified AOAC Method(mnb) 967.13, (3) Modified AOAC Method(pb) 967.13, (4) the Coder Method, (5) the Air Thaw Method, and (6) Modified AOAC Method 963.18. The same methods except Modified AOAC Method 963.18 were tested for determining thawed net weight of block-glazed shrimp. A total of 864 0.45 kg (1 lb), 0.90 kg (2 lb), and 1.35 kg (3 lb) IQF-glazed shrimp test samples and 234 2.25 kg (5 Ib) block-glazed shrimp test samples were collected. During sample preparation, test samples were subjected to either water with or without sodium tripolyphosphate (STP). During deglazing (IQF-glazed shrimp only) and/or thawing, test samples were allocated in a factorial design to assess the effects of STP presence (no STP and STP), sieve mesh sizes (2.83 and 2.38 mm; 0.11 and 0.09 in.), and sieve diameters (20 and 30 cm; 8 and 12 in.). During weighing, test samples were further allocated to a sequence of weighing procedures designed to assess the effects of using sieve weights (dry and wet) in combination with paper towel use (no and yes) and tared pan weights when calculating determined net weights. Cn the basis of the results of this precollaborative study, Modified AOAC Method(pb) 967.13 and the Air Thaw Method seem to be the best methods to determine net weight of IQF-glazed and block-glazed shrimp. Therefore, to validate method choices in the collaborative study, the authors recommend analysis of laf-glazed shrimp and block-glazed shrimp test samples, each prepared with or without STP, by Modified AOAC Method(pb) 967.13 and the Air Thaw Method. To fulfill AOAC requirements, IQF-glazed shrimp and block-glazed shrimp test samples, each prepared with or without STP, must be analyzed by official methods: AOAC: Method 963.18 (IQF-glazed shrimp only) and AOAC Method 967.13. During testing, sieve mesh size will be either 2.83 or 2.38 mm (0.11 or 0.09 in.), sieve diameter will be limited to 30 cm (12 in.), and weighing procedure will be limited to tared pan. C1 Natl Marine Fisheries Serv, US Dept Commerce, NOAA, Tech Serv Branch,Natl Stand & Specificat Sect, Gloucester, MA 01930 USA. US FDA, US Dept HHS, Ctr Food Safety & Appl Nutr, Off Sci Anal & Support,Div Math, Washington, DC 20204 USA. Univ S Alabama, Dept Math & Stat, Mobile, AL 36688 USA. Natl Marine Fisheries Serv, US Dept Commerce, NOAA, Natl Seafood Inspect Lab, Pascagoula, MS 39568 USA. RP Dobson, JEF (reprint author), Natl Marine Fisheries Serv, US Dept Commerce, NOAA, Tech Serv Branch,Natl Stand & Specificat Sect, 11-15 Parker St, Gloucester, MA 01930 USA. NR 7 TC 1 Z9 1 U1 1 U2 1 PU AOAC INTERNATIONAL PI GAITHERSBURG PA 481 NORTH FREDRICK AVE, STE 500, GAITHERSBURG, MD 20877-2504 USA SN 1060-3271 J9 J AOAC INT JI J. AOAC Int. PD JAN-FEB PY 1998 VL 81 IS 1 BP 69 EP 87 PG 19 WC Chemistry, Analytical; Food Science & Technology SC Chemistry; Food Science & Technology GA YW489 UT WOS:000071940800012 PM 9477564 ER PT J AU Tennyson, JM AF Tennyson, JM TI Seafoods SO JOURNAL OF AOAC INTERNATIONAL LA English DT Article; Proceedings Paper CT 111th AOAC INTERNATIONAL Annual Meeting CY SEP 07-11, 1997 CL SAN DIEGO, CALIFORNIA SP AOAC Int C1 Natl Marine Fisheries Serv, Natl Seafood Inspect Lab, Pascagoula, MS 39568 USA. RP Tennyson, JM (reprint author), Natl Marine Fisheries Serv, Natl Seafood Inspect Lab, 3209 Frederic St,PO Drawer 1207, Pascagoula, MS 39568 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU AOAC INTERNATIONAL PI GAITHERSBURG PA 481 NORTH FREDRICK AVE, STE 500, GAITHERSBURG, MD 20877-2504 USA SN 1060-3271 J9 J AOAC INT JI J. AOAC Int. PD JAN-FEB PY 1998 VL 81 IS 1 BP 172 EP 176 PG 5 WC Chemistry, Analytical; Food Science & Technology SC Chemistry; Food Science & Technology GA YW489 UT WOS:000071940800044 ER PT J AU Davet, J Clavel, B Datas, L Mani-Ponset, L Maurel, D Herbute, S Viso, M Hinds, W Jarvi, J Gabrion, J AF Davet, J Clavel, B Datas, L Mani-Ponset, L Maurel, D Herbute, S Viso, M Hinds, W Jarvi, J Gabrion, J TI Choroidal readaptation to gravity in rats after spaceflight and head-down tilt SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE choroid plexus; microvilli; ezrin; carbonic anhydrase II; electron microscopy; immunocytochemistry ID ATRIAL-NATRIURETIC-FACTOR; BRAIN-BARRIER; BINDING-SITES; PLEXUS; INVOLVEMENT; EPITHELIUM; EZRIN; MODEL; CELLS AB To determine when choroidal structures were restored after readaptation to Earth gravity or orthostatic position, fine structure and protein distribution were studied in rat choroid plexus dissected either 6 h [Space Life Sciences-2 (SLS-2) experiments] or 2 days [National Institutes of Health-Rodent 1 (NIH-R1) experiments] after a spaceflight, or 6 h after head-down tilt (KDT) experiments. Apical alterations were noted in choroidal cells from SLS-2 and HDT animals, confirming that weightlessness impaired choroidal structures and functions. However, the presence of small apical microvilli and kinocilia and the absence of vesicle accumulations showed that the apical organization began to be restored rapidly after landing. Very enlarged apical microvilli appeared after 2 days on Earth, suggesting increased choroidal activity. However, as distributions of ezrin and carbonic anhydrase II remained altered in both flight and suspended animals after readaptation to Earth gravity, it was concluded that choroidal structures and functions were not completely restored, even after 2 days in Earth's gravity. C1 CNRS, UMR 5539, F-34095 Montpellier, France. Univ Montpellier 2, Serv Commun Microscopie Electron, F-34095 Montpellier, France. Ctr Natl Etud Spatiales, Direct Programmes, F-75001 Paris, France. NASA, Ames Res Ctr, Moffett Field, CA 95034 USA. RP Gabrion, J (reprint author), Univ Paris 06, URA 1488 CNRS, Inst Neurosci, Boite 2,7 Quai St Bernard, F-75252 Paris 05, France. NR 30 TC 9 Z9 9 U1 0 U2 0 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD JAN PY 1998 VL 84 IS 1 BP 19 EP 29 PG 11 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA YR127 UT WOS:000071461000003 PM 9451613 ER PT J AU Bamman, MM Clarke, MSF Feeback, DL Talmadge, RJ Stevens, BR Lieberman, SA Greenisen, MC AF Bamman, MM Clarke, MSF Feeback, DL Talmadge, RJ Stevens, BR Lieberman, SA Greenisen, MC TI Impact of resistance exercise during bed rest on skeletal muscle sarcopenia and myosin isoform distribution SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE muscle atrophy; spaceflight; immunohistochemistry; strength; neural activation; unloading ID HEAVY-CHAIN COMPOSITION; STRENGTH; ADAPTATIONS; SPACEFLIGHT; ENDURANCE; COMPATIBILITY; FIBERS; SIZE; MEN; IIB AB Because resistance exercise (REx) and bed-rest unloading (BRU) are associated with opposing adaptations, our purpose was to test the efficacy of REx against the effects of 14 days of BRU on the knee-extensor muscle group. Sixteen healthy men were randomly assigned to no exercise (NoEx; n = 8) or REx (n = 8). REx performed five sets of leg press exercise with 80-85% of one repetition maximum (1 RM) every other day during BRU. Muscle samples were removed from the vastus lateralis muscle by percutaneous needle biopsy. Myofiber distribution was determined immunohistochemically with three monoclonal antibodies against myosin heavy chain (MHC) isoforms (I, IIa, IIx). MHC distribution was further assessed by quantitative gel electrophoresis. Dynamic 1-RM leg press and unilateral maximum voluntary isometric contraction (MVC) were determined. Maximal neural activation (root mean squared electromyogram) and rate of torque development (RTD) were measured during MVC. Reductions (P < 0.05) in type I (15%) and type II (17%) myofiber cross-sectional areas were found in NoEx but not in REx. Electrophoresis revealed no changes in MHC isoform distribution. The percentage of type IIx myofibers decreased (P < 0.05) in REx from 9 to 2% and did not change in NoEx. 1 RM was reduced (P < 0.05) by 9% in NoEx but was unchanged in REx. MVC fell by 15 and 13% in NoEx and REx, respectively. The agonist-to-antagonist root mean squared electromyogram ratio decreased (P < 0.05) 19% in REx. RTD slowed (P < 0.05) by 54% in NoEx only. Results indicate that REx prevented BRU-induced myofiber atrophy and also maintained training-specific strength. Unlike spaceflight, BRU did not induce shifts in myosin phenotype. The reported benefits of REx may prove useful in prescribing exercise for astronauts in microgravity. C1 Univ Alabama, Dept Human Studies, Birmingham, AL 35294 USA. NASA, Lyndon B Johnson Space Ctr, Life Sci Res Labs, Houston, TX 77058 USA. Univ Calif Los Angeles, Dept Physiol Sci, Los Angeles, CA 90095 USA. Univ Florida, Dept Physiol, Gainesville, FL 32611 USA. Univ Texas, Med Branch, Dept Internal Med, Galveston, TX 77550 USA. RP Bamman, MM (reprint author), Univ Alabama, Dept Human Studies, 901 S 13th St, Birmingham, AL 35294 USA. EM mbamman@uab.edu FU NCRR NIH HHS [M01 RR-00073] NR 37 TC 137 Z9 141 U1 2 U2 8 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD JAN PY 1998 VL 84 IS 1 BP 157 EP 163 PG 7 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA YR127 UT WOS:000071461000020 PM 9451630 ER PT J AU Osterman, GB Heelis, RA Bailey, GJ AF Osterman, GB Heelis, RA Bailey, GJ TI Effects of wind-induced ionization layers on ionospheric electrodynamics SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID INTERMEDIATE LAYERS; ARECIBO AB The electrodynamic consequences of ionization layers produced by zonal and meridional winds are examined by investigating the height integrated Pedersen conductivity, wind driven currents, and their spatial gradients, in the presence and absence of such layers. We find that a wind induced layer itself has little effect on the height integrated Pedersen conductivity when the process of layer creation involves depletion as well. as enhancement of the nominal background profile. The altitude gradients in the conductivity associated with the layer are both positive and negative and in the presence of neutral winds with long vertical wavelengths, they contribute little to the height integrated current divergence. However, short vertical wavelength meridional winds responsible for layer formation drive zonal currents with a divergence that depends on the horizontal scab of the layer itself and is likely to be small. compared to the vertical gradients. A significant contribution to the gradient in the height integrated meridional current is produced by the combined action of the layer conductivity and a short vertical wavelength zonal wind. In this case the presence of a layer can easily change this gradient by a factor of 2 and thus significantly effect the global electrodynamics. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Texas, William B Hanson Ctr Space Sci, Richardson, TX 75083 USA. RP Osterman, GB (reprint author), CALTECH, Jet Prop Lab, MS 183-301,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD JAN PY 1998 VL 60 IS 1 BP 107 EP 113 DI 10.1016/S1364-6826(97)00090-4 PG 7 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA YX888 UT WOS:000072090300011 ER PT J AU Mayr, HG Mengel, JG Chan, KL AF Mayr, HG Mengel, JG Chan, KL TI Equatorial oscillations maintained by gravity waves as described with the Doppler spread parameterization: I. Numerical experiments SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID QUASI-BIENNIAL OSCILLATION; MIDDLE ATMOSPHERE; SEMIANNUAL OSCILLATION; KELVIN WAVE; ZONAL WIND; SATURATION; MODEL; MESOSPHERE; DYNAMICS; STRATOSPHERE AB Gravity Waves (GW) as described with the Doppler Spread Parameterization (DSP) of Hines have been shown to produce significant Quasi-biennial and Semi-annual oscillations (QBO and SAO) in the zonal circulation at equatorial latitudes. To elucidate the process involved, we discuss computer experiments performed without the external, seasonal variations in solar differential heating, and the conclusions are summarized here. (1) As reported earlier, two kinds of oscillations are then generated spontaneously: one at lower altitudes in the stratosphere which has a long period approaching that of the QBO, the other one al higher altitudes in the mesosphere which has a shorter period close to that of the SAO. The amplitudes of these oscillations are weaker, however, than those generated with seasonal heating. (2) When the time independent solar healing is turned off, the oscillations continue but with significantly reduced period in the mesosphere where the vertical winds driven by solar differential heating produce Doppler shifting. The associated temperature variations are then small, consistent with the one dimensional prototype calculations discussed by Lindzen and Holton. (3) When the GW momentum source is turned off above 40 km to suppress the short-period oscillation, the long-period oscillation below continues with enhanced amplitude and period. When the source is turned off below 35 km, the amplitude of the short-period oscillation increases at higher altitudes, indicative of increased acceleration. (4) The wind oscillations change systematically and dramatically with changing eddy diffusivity/viscosity (K). The amplitudes and periods of both short- and long-period oscillations decrease (increase) with increasing (decreasing) K, and above a certain value of viscosity, both oscillations completely cease. Lowering K thus helps in generating a larger and longer period QBO at lower altitudes, but can be detrimental to the SAO when the natural oscillation period increase significantly above six months. (5) Under oscillation conditions, the height variations in the GW vertical wave numbers reveal a staircase pattern reflecting the intermittence characteristic of the wave interaction. It reveals the nonlinearity of the GW interaction to be of third (odd) order, which has the distinctive property that it can feed and maintain the fundamental harmonic of the oscillation-considered a prerequisite for sustaining the oscillations without external time dependent source. In the companion paper, an analytical model of the equatorial oscillation is presented which describes some of the trends reported here. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 NASA, Atmospher Chem & Dynam Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Space Applicat Corp, Vienna, VA USA. Hong Kong Univ Sci & Technol, Hong Kong, Peoples R China. RP Mayr, HG (reprint author), NASA, Atmospher Chem & Dynam Branch, Goddard Space Flight Ctr, Code 916,Mail Code 910-4, Greenbelt, MD 20771 USA. OI Chan, Kwing/0000-0002-6428-1812 NR 48 TC 19 Z9 19 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD JAN PY 1998 VL 60 IS 2 BP 181 EP 199 DI 10.1016/S1364-6826(97)00122-3 PG 19 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA ZF390 UT WOS:000072892700003 ER PT J AU Mayr, HG Hartle, RE Chan, KL AF Mayr, HG Hartle, RE Chan, KL TI Equatorial oscillations maintained by gravity waves as described with the Doppler spread parameterization: II. Heuristic analysis SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID QUASI-BIENNIAL OSCILLATION; SEMIANNUAL OSCILLATION; KELVIN WAVE; MODEL; STRATOSPHERE; MIDDLE AB The Doppler Spread Parameterization (DSP) for gravity waves (GW) developed by Hines is applied to the zonal momentum budget at the equator. For sufficiently large oscillation amplitudes in the background zonal winds, comparable to the GW induced wind variability, the momentum source is intermittent and as such it represents a nonlinearity of third or generally odd order. This kind of nonlinearity generates, besides higher harmonics, the fundamental harmonic itself which is retained in a simplified analytical solution that can describe self-sustained oscillations without invoking external, time dependent forcing. The formulation is discussed to provide some understanding of the numerical results presented in the companion paper. (C) 1998 Elsevier Science Ltd. C1 NASA, Atmospher Chem & Dynam Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Hong Kong Univ Sci & Technol, Hong Kong, Peoples R China. RP Mayr, HG (reprint author), NASA, Atmospher Chem & Dynam Branch, Goddard Space Flight Ctr, Code 916,Mail Code 910-4, Greenbelt, MD 20771 USA. OI Chan, Kwing/0000-0002-6428-1812 NR 18 TC 7 Z9 7 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD JAN PY 1998 VL 60 IS 2 BP 201 EP 213 DI 10.1016/S1364-6826(97)00123-5 PG 13 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA ZF390 UT WOS:000072892700004 ER PT J AU Furrow, APC Dillard, DA St Clair, TL Hinkley, J AF Furrow, APC Dillard, DA St Clair, TL Hinkley, J TI Dye penetrant induced microcracking in high performance thermoplastic polyimide composites SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article ID ORGANIC MEDIA; CRACKING AB The possibility of spurious microcracking in three high performance thermoplastic polyimide composite materials due to zinc iodine dye penetrant was studied. The material systems were IM7/LaRC(TM)-IAX, IM7/LaRC(TM)-IAX2, and IM7/LaRC(TM)-8515. Specimens from each material system were subjected to one of three immersion tests. The first immersion test involved soaking composite specimens previously prepared with different polishing techniques in dye penetrant. In the second test, specimens were soaked in the individual components of the dye penetrant. The final test involved soaking the specimens in one of six immersion liquids followed by soaking in dye penetrant. Results showed that the composite materials have sufficiently high thermal residual stresses to drive microcracking in the presence of dye penetrant without external mechanical loading. There was no evidence that the different polishing techniques had an effect on dye penetrant induced stress cracking. The individual components of the dye penetrant did not produce microcracks in the composites. Some combination of the components must be present to induce microcracking. Observations also revealed that polishing had an effect on the microcracking process of the composites that were initially soaked in immersion liquids then dye penetrant. C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Dillard, DA (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. RI Dillard, David/C-3185-2012 OI Dillard, David/0000-0002-2903-9318 NR 29 TC 4 Z9 4 U1 0 U2 2 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1998 VL 32 IS 1 BP 31 EP 48 PG 18 WC Materials Science, Composites SC Materials Science GA YV884 UT WOS:000071873500002 ER PT J AU Murthy, PLN Mital, SK Shah, AR AF Murthy, PLN Mital, SK Shah, AR TI Probabilistic micromechanics/macromechanics for ceramic matrix composites SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article AB Ceramic matrix: composites (CMCs) are known to display a considerable amount of scatter in their properties due to variations involved in fiber/matrix properties, interphase properties, interphase bonding, amount of matrix voids, and many geometric or fabrication process related parameters such as ply thickness and ply orientation. This paper summarizes the preliminary studies related to the incorporation of formal probabilistic descriptions of the material behavior and fabrication related parameters into micromechanics and macromechanics for CMCs. This process involves a synergistic coupling of two existing methodologies: namely ceramic matrix composite micro-and macromechanics analysis, and a fast probability integration (FPI) technique to obtain probabilistic composite behavior/response. Preliminary results in the form of cumulative probability distributions and information on the response probability sensitivities to primitive variables for a unidirectional SiC/RBSN ceramic matrix composite are presented. The cumulative distribution functions are computed for composite moduli, thermal expansion coefficients, thermal conductivities and longitudinal tensile strength at room temperature. Variations in the constituent properties that directly affect the above mentioned composite properties are accounted for via assumed probabilistic distributions. Collectively the results show that the present technique provides valuable information on the composite properties and sensitivity factors which are useful to the design/test engineers. Furthermore, the present methodology is computationally more efficient than a standard Monte-Carlo simulation technique and the agreement between the two is excellent as shown via select examples. C1 NASA, Lewis Res Ctr, Struct Mech Branch, Cleveland, OH 44135 USA. Univ Toledo, Toledo, OH 43606 USA. NYMA Inc, Cleveland, OH USA. RP NASA, Lewis Res Ctr, Struct Mech Branch, Mail Stop 23-3, Cleveland, OH 44135 USA. NR 8 TC 3 Z9 3 U1 0 U2 3 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0021-9983 EI 1530-793X J9 J COMPOS MATER JI J. Compos Mater. PY 1998 VL 32 IS 7 BP 679 EP 699 PG 21 WC Materials Science, Composites SC Materials Science GA ZJ680 UT WOS:000073241300005 ER PT J AU Wang, WX Takao, Y Yuan, FG Potter, BD Pater, RH AF Wang, WX Takao, Y Yuan, FG Potter, BD Pater, RH TI The interlaminar Mode I fracture of IM7/LaRC-RP46 composites at high temperatures SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE IM7/LaRC-RP46 composites; DCB test; interlaminar Mode I fracture toughness; high temperature; crack growth rate; crosshead rate ID GRAPHITE-EPOXY AB In this paper, the interlaminar Mode I fracture behavior of a IM7/LaRC-RP46 composite laminate at elevated temperatures was investigated by DCB (double cantilever beam) static fracture testing. Straight-sided DCB specimens were made from unidirectional laminates and tested at three high temperature levels of 232 degrees C (450 degrees F), 288 degrees C (550 degrees F) and 343 degrees C (650 degrees F) at five crosshead rates from 0.51 mm/min. (0.00033 in./sec) to 6.1 mm/min. (0.004 in./sec). Unlike the linear load-displacement response observed at room temperature, the load-displacement response at high temperatures behaves nonlinearly before reaching the maximum load. Two crack growth regions of slow crack extension and relatively fast crack propagation were observed and the slow crack extension caused the nonlinear load-displacement response. The initial fracture toughness, G(IC), decreased slightly, while the propagation value increased by nearly 30% to 100% with increased temperature. The materials exhibited the highest fracture toughness at 288 degrees C among the three different tested temperatures. The complex combination effects of fiber bridging and the change of matrix properties and fiber/matrix interfacial adhesion at elevated temperatures are found to be the major reason resulting in the variation of G(IC) with temperature. After the temperature increased beyond T-g (glass transition temperature), which is approximately 310 degrees C, the propagation fracture toughness decreased drastically and aging effects of the high temperature on the matrix are observed. No significant effects of crosshead rate on the G(IC) were observed in the range of the present rates. However, the crosshead rate is found to significantly influenced the crack growth rate. C1 Kyushu Univ, Appl Mech Res Inst, Fukuoka 8128580, Japan. N Carolina State Univ, Dept Mech & Aerosp Engn, Raleigh, NC 27695 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Wang, WX (reprint author), Kyushu Univ, Appl Mech Res Inst, Fukuoka 8128580, Japan. RI Kyushu, RIAM/F-4018-2015; U-ID, Kyushu/C-5291-2016 NR 13 TC 6 Z9 6 U1 2 U2 5 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1998 VL 32 IS 16 BP 1508 EP 1526 PG 19 WC Materials Science, Composites SC Materials Science GA 111TJ UT WOS:000075453400003 ER PT J AU Puh, JS Wagner, PA Little, BJ Bradley, WL AF Puh, JS Wagner, PA Little, BJ Bradley, WL TI The effect of biofouling on graphite/epoxy composites SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article; Proceedings Paper CT 1st Symposium on Non-Aerospace Applications for Composite Materials CY NOV, 1996 CL NEW ORLEANS, LOUISIANA SP Amer Soc Testing & Mat, Comm D 30 Composite Mat DE polymeric composites; microbiologically influenced corrosion; biodeterioration; mechanical testing; acoustic emission; microbial; carbon fiber; seawater ID DEGRADATION AB This research program seeks to determine if the presence of marine microorganisms and the biofouling they produce will accelerate the degradation of graphite/epoxy composite materials. Graphite/epoxy samples were conditioned for 4 months in sterilized seawater(no microorganisms), natural seawater (with microorganisms), and air. In addition, half of the tested samples were also subjected to three-point bending while conditioning. Moisture absorption data was gathered before and after immersion and correlated with tensile and acoustic emission data. Results of tensile tests showed seawater in general had a larger effect on ultimate tensile strength than microorganism effects. However, sample stress state while conditioning had negligible effect on mechanical properties. These results were most likely due to plasticization of the matrix and relief of fabrication residual stresses through moisture absorption and fiber dominated behavior of the specimens. Acoustic emission results showed that the trend for high amplitude hits for each exposure condition was consistent with the tensile test results. However, due to the effects of moisture on three different relaxation mechanisms, the low amplitude hits were not as consistent. C1 Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. RP Puh, JS (reprint author), Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. NR 16 TC 1 Z9 1 U1 1 U2 7 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD JAN PY 1998 VL 20 IS 1 BP 59 EP 67 PG 9 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA ZP544 UT WOS:000073764100008 ER PT J AU Pavlo, P Vahala, G Vahala, L Soe, M AF Pavlo, P Vahala, G Vahala, L Soe, M TI Linear stability analysis of thermo-lattice Boltzmann models SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID NAVIER-STOKES EQUATION; BGK MODELS; SIMULATION; SYSTEMS; FLOW AB The numerical stability of thermo-lattice Boltzmann (TLBE) models is presented. The TLBE algorithm is linearized and represented in matrix form. The spectral radius of the resulting matrix is obtained by the method of powers. In particular, the numerical stability of two 2-speed 13-bit TLBE models-one based on the hexagonal lattice, and the other on a square lattice-is examined. For these two TLBE models, as a function of the energy density, the achievable Reynolds number (before the onset of grid modes) is more than an order of magnitude greater for the hexagonal grid than for the square grid. (C) 1998 Academic Press. C1 Acad Sci Czech Republ, Inst Plasma Phys, Brno, Czech Republic. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. NASA, ICASE, Hampton, VA 23681 USA. Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. RP Pavlo, P (reprint author), Acad Sci Czech Republ, Inst Plasma Phys, Brno, Czech Republic. RI Pavlo, Pavol/G-4214-2014 OI Pavlo, Pavol/0000-0003-1400-1074 NR 26 TC 39 Z9 40 U1 1 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JAN 1 PY 1998 VL 139 IS 1 BP 79 EP 91 DI 10.1006/jcph.1997.5864 PG 13 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA YZ719 UT WOS:000072284000005 ER PT J AU Kim, SH Korpela, SA Chait, A AF Kim, SH Korpela, SA Chait, A TI Axial segregation in unsteady diffusion-dominated solidification of a binary alloy SO JOURNAL OF CRYSTAL GROWTH LA English DT Article AB Axial segregation in unsteady diffusion dominated directional solidification of a binary alloy with a planar solid-liquid interface profile is considered. The analysis is an extension of the work of Smith rt al. [Canadian J. Phys. 33 (1955) 723] to account for an arbitrary initial axial concentration profile, This situation is important in the experimental studies of growth of crystals in a microgravity environment in which the growth is from melts formed by remelting crystals that have a known axial impurity profile. Three situations are discussed. These are the initial transient, a resolidified crystal,and multipass solidification. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Ohio State Univ, Dept Mech Engn, Columbus, OH 43210 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Korpela, SA (reprint author), Ohio State Univ, Dept Mech Engn, 206 W 18th Ave, Columbus, OH 43210 USA. NR 5 TC 4 Z9 4 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN PY 1998 VL 183 IS 3 BP 490 EP 496 DI 10.1016/S0022-0248(97)00438-7 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA YU129 UT WOS:000071685200024 ER PT J AU Ghorayeb, SR Xue, T Lord, W AF Ghorayeb, SR Xue, T Lord, W TI A finite element study of ultrasonic wave propagation in a tooth phantom SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE finite element; ultrasonic testing; dental diagnostics ID SOLIDS; FIELDS AB Ultrasound is used extensively in industry for the detection and characterization of defects in critical engineering structures. Similar techniques could be used in dentistry if a thorough understanding of ultrasonic wave propagation in teeth were available. This paper presents a hypothesis that finite element analysis can be used to solve the hyperbolic partial differential equation which governs ultrasonic wave propagation in teeth. A three-layer tooth phantom based on the geometry of a human second molar is used to illustrate the validity of this hypothesis. Simulated wave propagation studies are described for the tooth phantom with a gold crown layer, with an amalgam restoration insertion, and containing a cavity. Results clearly show the finite element code's ability to predict and visualize ultrasonic wave propagation in complex dental structures. C1 Hofstra Univ, Dept Engn, Hempstead, NY 11549 USA. Iowa State Univ Sci & Technol, Dept Elect & Comp Engn, Ames, IA 50011 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Iowa State Univ Sci & Technol, Dept Elect & Comp Engn, Durham Ctr 391, Ames, IA 50011 USA. RP Ghorayeb, SR (reprint author), Hofstra Univ, Dept Engn, 104 Weed Hall, Hempstead, NY 11549 USA. NR 15 TC 17 Z9 17 U1 0 U2 1 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD JAN PY 1998 VL 77 IS 1 BP 39 EP 49 PG 11 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YQ665 UT WOS:000071411000008 PM 9437398 ER PT J AU Wang, RR Hwang, YH Castro-Cedeno, M AF Wang, RR Hwang, YH Castro-Cedeno, M TI Corrosion evaluation of a Ti-Co alloy for cast dental restorations. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1998 VL 77 SI A MA 159 BP 125 EP 125 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU125 UT WOS:000071684800157 ER PT J AU Colantonio, RO AF Colantonio, RO TI The applicability of jet-shear-layer mixing and effervescent atomization for Low-NOx combustors SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB An investigation has been conducted to develop appropriate technologies for a low-NOx, liquid-fueled combustor. The combustor incorporates an effervescent atomizer used to inject fuel into a premixing duct. Only a fraction of the combustion air is used in the premixing process. This fuel-rich mixture is introduced into the remaining combustion air by a rapid jet-shear-layer mixing process involving radial fuel-air jets impinging on axial air jets in the primary combustion zone. Computational modeling was used as a tool to facilitate a parametric analysis appropriate to the design of an optimum low-NOx combustor A number of combustor configurations were studied to assess the kev combustor technologies and to validate the three-dimensional modeling code. The results from the experimental testing and computational analysis indicate a low-NOx potential for the jet-shear-layer combustor. Key features found to affect NOx emissions are the primary combustion zone fuel-air ratio, the number of axial and radial jets, the aspect ratio and radial location of the axial air jets, and the radial jet inlet hole diameter. Each of these key parameters exhibits a low-NOx point from which an optimized combustor was developed Also demonstrated was the feasibility of utilizing an effervescent atomizer for combustor application. Further developments in the jet-shear-layer mixing scheme and effervescent atomizer design promise even lower NOx with high combustion efficiency. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Colantonio, RO (reprint author), NASA, Lewis Res Ctr, 21000 Brookpk Rd,Mail Stop 500-115, Cleveland, OH 44135 USA. NR 26 TC 1 Z9 2 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 17 EP 23 DI 10.1115/1.2818073 PG 7 WC Engineering, Mechanical SC Engineering GA YV243 UT WOS:000071803700003 ER PT J AU Kasarda, MEF Allaire, PE Maslen, EH Brown, GR Gillies, GT AF Kasarda, MEF Allaire, PE Maslen, EH Brown, GR Gillies, GT TI High speed rotor losses in a radial eight pole magnetic bearing: Part 1 - Experimental measurement SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 41st International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 10-13, 1996 CL BIRMINGHAM, ENGLAND AB The continual increase in the use of magnetic bearings in various capacities, including high-speed aerospace applications such as jet engine prototypes, dictates the need to quantify power losses in this type of bearing. The goal of this study is to present experimentally measured power losses during the high-speed operation of a pair of magnetic bearings. A large-scale test rotor has been designed and built to obtain unambiguous power loss measurements while varying a variety of test parameters. The test apparatus consists of a shaft supported in two radial magnetic bearings and driven by two electric motors also mounted on the shaft. The power losses of the spinning rotor are determined from the time rate of change of the kinetic energy of the rotor as its angular speed decays during free rotation. Measured results for the first set of magnetic bearings, a pair of eight-pole planar radial bearings, are presented here. Data from three different parameter studies including the effect of the bins flux density, the effect of the bearing pole configuration and the effect of the motor stator on the power loss are presented. Rundown plots of the test with the bearings in the paired pole (NNSS) versus the alternating (NSNS) pole configuration show only small differences, with losses only slightly higher when the poles are in the alternating pole (NSNS) configuration Loss data were also taken with the motor stators axially removed from the motor rotors for comparison with the case where the motor stators are kept in place. No measurable difference was observed between the two cases, indicating negligible windage and residual magnetic effects. Throughout most of the speed range, the dominant loss mechanism appears to be eddy currents. C1 Univ Virginia, Dept Mech Nucl & Aerosp Engn, Charlottesville, VA 22903 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Kasarda, MEF (reprint author), Univ Virginia, Dept Mech Nucl & Aerosp Engn, Charlottesville, VA 22903 USA. NR 9 TC 5 Z9 5 U1 1 U2 6 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 105 EP 109 DI 10.1115/1.2818059 PG 5 WC Engineering, Mechanical SC Engineering GA YV243 UT WOS:000071803700014 ER PT J AU Kasarda, MEF Allaire, PE Maslen, EH Brown, GR Gillies, GT AF Kasarda, MEF Allaire, PE Maslen, EH Brown, GR Gillies, GT TI High-speed rotor losses in a radial eight-pole magnetic bearing: Part 2 - Analytical/empirical models and calculations SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 41st International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 10-13, 1996 CL BIRMINGHAM, ENGLAND AB The continual increase in the use of magnetic bearings in various capacities, including high-speed aerospace applications such as jet engine prototypes, dictates the need to quantity power lasses in this type of bearing. The goal of the present study is to develop and experimentally verify, general power loss equations for the high-speed operation of magnetic bearings. Experimental data from a large-scale test rotor have been presented in Part I of this study. Analytical/empirical predictions are presented here for the test bearings, a pair of eight-pole planar radial bearings, for comparison to the experimental results from Part 1. Expressions for the four loss components, eddy current, alternating hysteresis, rotating hysteresis, and windage, are also presented. Analytical/empirical predictions for the rest bearings at three different bias flux levels demonstrate good correlation with corresponding experimental data. Throughout most of the speed range the dominant loss mechanism appears to be eddy currents. C1 Univ Virginia, Dept Mech Nucl & Aerosp Engn, Charlottesville, VA 22903 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Kasarda, MEF (reprint author), Univ Virginia, Dept Mech Nucl & Aerosp Engn, Charlottesville, VA 22903 USA. NR 20 TC 3 Z9 3 U1 1 U2 4 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 110 EP 114 DI 10.1115/1.2818060 PG 5 WC Engineering, Mechanical SC Engineering GA YV243 UT WOS:000071803700015 ER PT J AU Janosik, LA Duffy, SF AF Janosik, LA Duffy, SF TI A viscoplastic constitutive theory for monolithic ceramics - I SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 41st International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 10-13, 1996 CL BIRMINGHAM, ENGLAND ID PLASTICITY THEORY; DEFORMATION; METALS; LIFE AB This paper, which is the first of two in a series, provides an overview of a viscoplastic constitutive model that accounts for time-dependent material deformation (e.g., creep, stress relaxation, etc.) in monolithic ceramics. Using continuum principles of engineering mechanics, the complete theory is derived from a scalar dissipative potential function first proposed by Robinson (1978), and later utilized by Duffy (1988). Derivations based on a flow potential function provide an assurance that the inelastic boundary value problem is well posed, and solutions obtained are unique. The specific formulation used here for the threshold function (a component of the flow potential function) was originally proposed by Willam and Warnke (1975) in order to formulate constitutive equations for time-independent classical plasticity behavior observed in cement and unreinforced concrete. Here constitutive equations formulated for the flow law (strain rate) and evolutionary law employ stress invariants to define the functional dependence on the Cauchy stress and a tensorial state variable. This particular formulation of the viscoplastic model exhibits a sensitivity to hydrostatic stress, and allows different behavior in tension and compression. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Cleveland State Univ, Cleveland, OH 44115 USA. RP Janosik, LA (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 23 TC 4 Z9 5 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 155 EP 161 DI 10.1115/1.2818069 PG 7 WC Engineering, Mechanical SC Engineering GA YV243 UT WOS:000071803700022 ER PT J AU Powers, LM Jadaan, OM Gyekenyesi, JP AF Powers, LM Jadaan, OM Gyekenyesi, JP TI Creep life of ceramic components using a Finite-Element-Based Integrated Design Program (CARES/CREEP) SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 41st International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 10-13, 1996 CL BIRMINGHAM, ENGLAND ID ADVANCED SILICON-NITRIDE; STRESS RUPTURE BEHAVIOR; FATIGUE AB The desirable properties of ceramics at high temperatures have generated interest in their use for structural applications such as in advanced turbine systems. Design lives for such systems can exceed 10,000 hours. The long life requirement necessitates subjecting the components to relatively low stresses. The combination of high temperatures and low stresses typically places failure for monolithic ceramics in the creep regime. The objective of this paper is to present a design methodology for predicting the lifetimes of structural components subjected to creep rupture conditions. This methodology utilizes commercially available finite element packages and takes into account the time-varying creep strain distributions (stress relaxation). The creep life of a component is discretized into short time steps, during which the stress and strain distributions are assumed constant. The damage is calculated for each time step based on a modified Monkman-Grant creep rupture criterion. Failure is assumed to occur when the normalized accumulated damage at any point in the component is greater than or equal to unity. The corresponding time will be the creep rupture life for that component. Examples are chosen to demonstrate the CARES/CREEP (Ceramics Analysis and Reliability Evaluation of Structures/CREEP) integrated design program, which is written for the ANSYS finite element package. Depending on the component size and loading conditions, it was Sound that in real structures one of two competing failure modes (creep or slow crack growth) will dominate. Applications to benchmark problems and engine components are included. C1 Cleveland State Univ, Cleveland, OH 44115 USA. Univ Wisconsin, Platteville, WI 53818 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Powers, LM (reprint author), Cleveland State Univ, Cleveland, OH 44115 USA. NR 44 TC 2 Z9 2 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 162 EP 171 DI 10.1115/1.2818070 PG 10 WC Engineering, Mechanical SC Engineering GA YV243 UT WOS:000071803700023 ER PT J AU Moles, A Heifetz, J AF Moles, A Heifetz, J TI Effects of the brain parasite Myxobolus arcticus on sockeye salmon SO JOURNAL OF FISH BIOLOGY LA English DT Article DE Myxobolus; swimming; osmocompetence ID ONCORHYNCHUS-NERKA; SWIMMING PERFORMANCE; MYXOSPOREAN PARASITE; BRITISH-COLUMBIA; SEAWATER; SURVIVAL; KISUTCH; RIVER; WILD AB Parasitism with Myxobolus arcticus did not affect smolt size of sockeye salmon or their osmocompetence, but had a deleterious effect (P<0.001) on the swimming speed of naturally infected smolts. Parasitized fish had a mean swimming speed of 2.89 fork length s(-1) (L-F s(-1)) compared with 4.37 L-F s(-1) for unparasitized fish. The parasite probably impairs swimming ability by affecting the central nervous system, but this effect does not appear severe enough to limit the parasite's usefulness in stock separation. (C) 1998 The Fisheries Society of the British Isles. C1 Natl Marine Fisheries Serv, Auke Bay Lab, Alaska Fisheries Sci Ctr, Natl Ocean & Atmospher Adm, Juneau, AK 99801 USA. RP Moles, A (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, Alaska Fisheries Sci Ctr, Natl Ocean & Atmospher Adm, 11305 Glacier Highway, Juneau, AK 99801 USA. EM adam.moles@noaa.gov NR 20 TC 13 Z9 14 U1 2 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD JAN PY 1998 VL 52 IS 1 BP 146 EP 151 DI 10.1006/jfbi.1997.0571 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA YR647 UT WOS:000071516200013 ER PT J AU Collier, MR Hamilton, DC Gloeckler, G Ho, G Bochsler, P Bodmer, R Sheldon, R AF Collier, MR Hamilton, DC Gloeckler, G Ho, G Bochsler, P Bodmer, R Sheldon, R TI Oxygen 16 to oxygen 18 abundance ratio in the solar wind observed by Wind/MASS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HIGH-RESOLUTION; SPACECRAFT; ISOTOPES; IONS; ACCELERATION; CORONA; NUCLEI AB Measurements of the O-16 and O-18 distribution functions in the solar wind at low to average solar wind speeds from the MASS instrument on the wind spacecraft are reported. The O-16/O-18 density ratio is 450 +/- 130, a value consistent with terrestrial, solar photospheric, solar energetic particle, and galactic cosmic ray O-16/O-18 isotopic ratios. This study constitutes the first reported spacecraft measurement of the isotope O in the core solar wind and may represent the best determination of the solar O-16/O-18 density ratio to date. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Collier, MR (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RI Collier, Michael/I-4864-2013; Ho, George/G-3650-2015; OI Collier, Michael/0000-0001-9658-6605; Ho, George/0000-0003-1093-2066; Hamilton, Douglas/0000-0001-6103-8019 NR 33 TC 25 Z9 25 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 7 EP 13 DI 10.1029/97JA02245 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900002 ER PT J AU Maynard, NC Burke, WJ Weimer, DR Mozer, FS Scudder, JD Russell, CT Peterson, WK Lepping, RP AF Maynard, NC Burke, WJ Weimer, DR Mozer, FS Scudder, JD Russell, CT Peterson, WK Lepping, RP TI Polar observations of convection with northward interplanetary magnetic field at dayside high latitudes SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTRIC-FIELD; BIRKELAND CURRENTS; BOUNDARY-LAYER; PARTICLE-PRECIPITATION; ALIGNED CURRENTS; LOW ALTITUDE; MODEL; CUSP; PLASMA; IMF AB This study of dayside electrodynamics provides a first view of quasi-dc electric fields measured by Polar at middle altitudes. Three high-latitude passes chosen for analysis, occurred while Polar was in the midday sector and the interplanetary magnetic field (IMF) maintained a steady northward orientation at clock angles near 40 degrees in the Y-GSM - Z(GSM) plane. different times during the passes, Polar encountered electron and ion fluxes from the central plasma sheet (CPS), the boundary plasma sheet, the-polar rain, and various magnetospheric boundary regions. Although electric fields measured within the boundary layers were highly variable, we derived average components of plasma convection. The results compare favorably with convection characteristics of four-cell patterns observed at ionospheric altitudes with northward IMF. We show that Polar encountered lobe cells of both positive and negative polarity in the early postnoon sector. The negative potential extends well into the prenoon sector, inverse, energy-dispersed fluxes of He++ were detected in regions of sunward convection. Sunward convection extended into the region of polar rain north of the merging line's projection. The magnetic merging signatures indicate that the process is both time varying and patchy. Particle and field measurements are consistent with the afternoon, auroral convection cell closing in the low-latitude boundary layer, which extend many tens of R-E tailward of the dusk terminator. Taken in a larger context, the Polar measurements provide new insight concerning the evolution of high-latitude convection from distorted two-cell patterns at large IMF clock angles to four cells at low clock angles. C1 Mission Res Corp, Nashua, NH 03062 USA. Phillips Lab, Hanscom AFB, MA 01731 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Lockheed Martin Space Sci Lab, Palo Alto, CA 94304 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90049 USA. Univ Iowa, Dept Space Phys & Astron, Iowa City, IA 52240 USA. RP Maynard, NC (reprint author), Mission Res Corp, 1 Tara Blvd,Suite 302, Nashua, NH 03062 USA. RI Scudder, Jack/D-8417-2013; Peterson, WK/A-8706-2009; OI Scudder, Jack/0000-0001-7975-5630; Peterson, WK/0000-0002-1513-6096; Russell, Christopher/0000-0003-1639-8298 NR 43 TC 10 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 29 EP 45 DI 10.1029/97JA02295 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900004 ER PT J AU Jordanova, VK Farrugia, CJ Janoo, L Quinn, JM Torbert, RB Ogilvie, KW Lepping, RP Steinberg, JT McComas, DJ Belian, RD AF Jordanova, VK Farrugia, CJ Janoo, L Quinn, JM Torbert, RB Ogilvie, KW Lepping, RP Steinberg, JT McComas, DJ Belian, RD TI October 1995 magnetic cloud and accompanying storm activity: Ring current evolution SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; GEOMAGNETIC STORMS; MAGNETOSPHERIC MODEL; IONS; PROTON; EARTH; DISTURBANCES; PARTICLES; PASSAGE; FIELDS AB The passage at Earth of the October 1995 magnetic cloud and the high-speed corotating stream overtaking it,monitored by the Global Geospace Science (GGS) spacecraft Wind, caused two consecutive geomagnetic storms: a major one during the strong B-z < 0 nT phase of cloud passage and a moderate one during the intermittent B-z < 0 activity in the fast corotating stream. Large dynamic pressure changes were observed in the sheath region ahead of the cloud and in the cloud-stream interface region at its rear, resulting in substantial corrections to the measured Dst index. A burst of superdense plasma sheet extending over similar to 2 hours in local time was observed at geostationary orbit during the second storm. We simulate the ring current development during this storm period using our kinetic model and calculate the magnetic field perturbation caused by the ring current. The plasma inflow on the nightside is modeled throughout the investigated period using data measured at geosynchronous orbit. The modeled Dst index is compared with the observed Dst values corrected for magnetopause and telluric currents. The temporal evolution of the ring current H+ and O+ distribution functions is computed, considering losses due to charge exchange, Coulomb collisions, and ion precipitation. We find that (1) the storm time enhancement of the plasma sheet ion population contributed significantly to the ring current buildup; (2) an additional similar to 12 nT decrease in Dst is achieved when the symmetry line of the plasma convection paths is rotated eastward from the dawn-dusk direction with 3 hours during the first storm; (3) the major loss process is charge exchange, followed by Coulomb collisions and ion precipitation; (4) however, the energy losses due to ion precipitation increase monotonically during the more active periods, reaching the level of Coulomb losses at peak storm intensity. We argue that the losses due to ion precipitation considered in this study are closely related to the enhanced convection electric field, which in our model is parameterized with the planetary Kp index. Correspondingly, we find that (5) there is a very good correlation between the variations in time of this index and the magnitude of the ion precipitation losses. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. RP Jordanova, VK (reprint author), Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. EM vania.jordanova@unh.edu OI Jordanova, Vania/0000-0003-0475-8743 NR 48 TC 93 Z9 93 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 79 EP 92 DI 10.1029/97JA02367 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900008 ER PT J AU Fairfield, DH Mukai, T Lui, ATY Cattell, CA Reeves, GD Nagai, T Rostoker, G Singer, HJ Kaiser, ML Kokubun, S Lazarus, AJ Lepping, RP Nakamura, M Steinberg, JT Tsuruda, K Williams, DJ Yamamoto, T AF Fairfield, DH Mukai, T Lui, ATY Cattell, CA Reeves, GD Nagai, T Rostoker, G Singer, HJ Kaiser, ML Kokubun, S Lazarus, AJ Lepping, RP Nakamura, M Steinberg, JT Tsuruda, K Williams, DJ Yamamoto, T TI Geotail observations of substorm onset in the inner magnetotail SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NEAR-EARTH MAGNETOTAIL; PLASMA SHEET; CURRENT DISRUPTION; MAGNETIC-FIELD; MAGNETOSPHERIC SUBSTORMS; ION COMPOSITION; ELECTRIC-FIELD; GROWTH-PHASE; PARTICLE; SIGNATURES AB On April 26, 1995, while Geotail was in the near-equatorial magnetotail at 13 R-E and 2300 LT, a substorm onset occurred that was documented by ground magnetograms, auroral kilometric radiation, and magnetic field and particle data from four spacecraft at and near geosynchronous orbit. Although Geotail was initially outside a greatly thinned current sheet, plasma sheet thickening associated with the substorm dipolarization quickly caused Geotail to move into the plasma sheet where it observed field-aligned earthward moving ions with velocities of 400 km/s. During the subsequent few minutes as the magnetic field became more northward, the velocities increased with particles moving increasingly into the energy range of the energetic particle experiment. These flows culminated with 1-min worth of earthward flow of 2000 km/s that was perpendicular to the northward B field. Such how, probably the largest ever detected at 13 R-E, was confirmed by the observation of an intense de electric field of 50 m V/m (0.3 megavolts/R-E). This large field is probably inductive, caused by reconnection that occurred tailward of the spacecraft, and related to the acceleration processes associated with particle injection at geosynchronous orbit. Energy and magnetic flux conservation arguments suggest that this rapid flow has a small cross-tail dimension of the order of 1 R-E. The data appear to support a simulation of Birn and Hesse [1996] which showed rapid earthward flows from a reconnection line at 23 R-E that caused a tailward expansion of a region of dipolarized flux. Subsequent to the onset, Geotail observed plasma vortices with typical velocities of 50-100 km/s that occurred in a high-beta plasma sheet with a 15-nT northward magnetic field. The vortices were punctuated by occasional flow bursts with velocities up to 400 km/s, one of which was accompanied by a violently varying magnetic field where north/south field components were as large as 30 nT and as small as -8 nT. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Nagoya Univ, STELAB, Toyokawa 442, Japan. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Tokyo Inst Technol, Tokyo 152, Japan. Univ Tokyo, Dept Earth & Planetary Phys, Bunkyo Ku, Tokyo 113, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Alberta, Canadian Network Space Res, Edmonton, AB T6G 2J1, Canada. Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Fairfield, DH (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RI Reeves, Geoffrey/E-8101-2011; OI Reeves, Geoffrey/0000-0002-7985-8098; Cattell, Cynthia/0000-0002-3805-320X NR 60 TC 73 Z9 75 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 103 EP 117 DI 10.1029/97JA02043 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900010 ER PT J AU Slavin, JA Fairfield, DH Kuznetsova, MM Owen, CJ Lepping, RP Taguchi, S Mukai, T Saito, Y Yamamoto, T Kokubun, S Lui, ATY Reeves, GD AF Slavin, JA Fairfield, DH Kuznetsova, MM Owen, CJ Lepping, RP Taguchi, S Mukai, T Saito, Y Yamamoto, T Kokubun, S Lui, ATY Reeves, GD TI ISTP observations of plasmoid ejection: IMP 8 and Geotail SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TRAVELING COMPRESSION REGIONS; MAGNETIC-FLUX ROPES; DEEP GEOMAGNETIC TAIL; DISTANT MAGNETOTAIL; EARTHS MAGNETOTAIL; ISEE-3 OBSERVATIONS; SUBSTORM; EVOLUTION; SPACECRAFT; RECONNECTION AB IMP 8 and Geotail observations of traveling compression regions (TCRs) and plasmoids, respectively, are used to investigate plasmoid formation and ejection. One year of IMP 8 magnetometer measurements taken during the distant tail phase of the Geotail mission were searched for TCRs, which signal the release of plasmoids down the tail. A total of 10 such intervals were identified. Examination of the Geotail measurements showed that this spacecraft was in the magnetotail for only three of the events. However, in all three cases, clear plasmoid signatures were observed at Geotail. These plasmoids were observed at distances of X = -170 to -197 R-E. The in situ plasma velocities in these plasmoids are found to exceed the time-of-flight speeds between IMP 8 and Geotail suggesting that some further acceleration may have taken place following release. The inferred lengths of these plasmoids, similar to 27-40 R-E, are comparable to the downtail distance of IMP 8. This indicates that TCR at IMP 8 can be caused by plasmoids forming not only earthward but also adjacent to or just tailward of the spacecraft. The closeness of IMP 8 to the point of plasmoid formation is confirmed by the small, similar to 0-3 min, time delays between the TCR perturbation and substorm onset. In two of the plasmoid events, high-speed earthward plasma flows and streaming energetic particles were measured in the plasma sheet boundary layer surrounding the plasmoid along with large positive B-z at the leading edge of the plasmoid suggesting that the core of the plasmoid was "snow plowing" into flux tubes recently closed at an active distant neutral line. In summary, these unique two-point measurements clearly show plasmoid ejection near substorm onset, their rapid movement to the distant tail and their further evolution as they encounter preexisting X lines in the distant tail. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Nagoya Univ, Solar Terr Environm Lab, Aichi 46401, Japan. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Univ London Queen Mary & Westfield Coll, Astron Unit, London E1 4NS, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Electrocommun, Dept Elect Engn, Tokyo, Japan. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. RP Slavin, JA (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RI Owen, Christopher/C-2999-2008; Kuznetsova, Maria/F-6840-2012; Slavin, James/H-3170-2012; Reeves, Geoffrey/E-8101-2011 OI Owen, Christopher/0000-0002-5982-4667; Slavin, James/0000-0002-9206-724X; Reeves, Geoffrey/0000-0002-7985-8098 NR 56 TC 26 Z9 26 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 119 EP 133 DI 10.1029/97JA02136 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900011 ER PT J AU Winglee, RM Kokubun, S Lin, RP Lepping, RP AF Winglee, RM Kokubun, S Lin, RP Lepping, RP TI Flux rope structures in the magnetotail: Comparison between Wind/Geotail observations and global simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETIC RECONNECTION; PARTICLE SIMULATIONS; SHEET; PLASMOIDS; TAIL AB On December 11, 1994, Geotail observed several reconnection (negative Bz) events at a position 30-40 R-E down the tail over a 24 hour period. This period is also interesting because the solar wind conditions were well monitored by Wind, which was only about 20 R-E in front of the bow shock, and because IMP 8 was at nearly the same x value as Geotail, but at high latitudes. Global fluid simulations that incorporate higher-order corrections to Ohm's law are used to produce a three dimensional picture of the reconnection site in conjunction with the Geotail data. It is shown that many of the negative B-z events have appreciable core magnetic fields, which in the modeling appear to form around 20 R-E about 10 min earlier than observed by Geotail. The predicted time of the formation coincides approximately with increased ionospheric activity observed by the Canadian Auroral Network for the OPEN Program Unified Study (CANOPUS) magnetometer chain. The flux ropes also appear to be highly localized (2-4 R-E), particularly in x and z when they are first created. In addition, they have a distinctive bipolar core magnetic field, but the probability that a spacecraft observes a unidirectional or bipolar signature is highly dependent on the position of the center of the current sheet relative to the spacecraft. Bipolar signatures are predicted to be most easily seen when the spacecraft is near the center of the current sheet, while unidirectional signatures are most likely to be observed at more distant encounters. C1 Univ Washington, Geophys Program, Seattle, WA 98195 USA. Nagoya Univ, STELAB, Aichi 442, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Winglee, RM (reprint author), Univ Washington, Geophys Program, Box 351650, Seattle, WA 98195 USA. NR 27 TC 24 Z9 24 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 135 EP 150 DI 10.1029/97JA02415 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900012 ER PT J AU Kuznetsova, MM Hesse, M Winske, D AF Kuznetsova, MM Hesse, M Winske, D TI Kinetic quasi-viscous and bulk flow inertia effects in collisionless magnetotail reconnection SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID 2-DIMENSIONAL CURRENT SHEETS; THIN CURRENT SHEETS; MAGNETIC RECONNECTION; HYBRID SIMULATIONS; TEARING MODE; PARTICLE SIMULATION; ELECTRON DYNAMICS; X-LINE; PLASMA; CONFIGURATION AB Both electron inertia and nongyrotropic effects were analysed using 2 1/2-dimensional hybrid simulations of collisionless magnetic reconnection. The traditional hybrid approach which treats ions as particles and electrons as an isotropic massless fluid was modified. In the new model the electron mass dependence was introduced both in the expression for the electric field and in the evolution equation of the full electron pressure tensor. This comprehensive hybrid model includes full ion kinetics, incorporates Hall effects, describes the leading terms in electron dynamics responsible for breaking the frozen magnetic flux constraint and allows to consider arbitrary ion/electron temperature and mass ratios. We demonstrate that the kinetic quasi-viscous electron inertia associated with nongyrotropic pressure effects dominates over the electron bulk flow inertia in controlling the structure of the dissipation region around the neutral X line. The reconnection electric field based on the nongyrotropic pressure tends to reduce the current density and to relax gradients in the vicinity of the X line (similar to the localized anomalous viscosity). On the other hand, the reconnection electric field based on electron bulk flow inertia tends to require an increased current density, with gradient scales comparable with the, electron skin depth. The dependence on the ion/electron temperature ratio and on the current carrier also is discussed. An analytical analysis which supports the results of the numerical simulations is also presented. C1 NASA, Goddard Space Flight Ctr, Electrodynam Branch, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Alamos Natl Lab, Div Appl Theoret Phys, Los Alamos, NM 87545 USA. RP Kuznetsova, MM (reprint author), Hughes STX Corp, Lanham, MD 20706 USA. RI Hesse, Michael/D-2031-2012; Kuznetsova, Maria/F-6840-2012 NR 46 TC 74 Z9 74 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 199 EP 213 DI 10.1029/97JA02699 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900017 ER PT J AU Burlaga, L Fitzenreiter, R Lepping, R Ogilvie, K Szabo, A Lazarus, A Steinberg, J Gloeckler, G Howard, R Michels, D Farrugia, C Lin, RP Larson, DE AF Burlaga, L Fitzenreiter, R Lepping, R Ogilvie, K Szabo, A Lazarus, A Steinberg, J Gloeckler, G Howard, R Michels, D Farrugia, C Lin, RP Larson, DE TI A magnetic cloud containing prominence material: January 1997 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; DISAPPEARING SOLAR FILAMENTS; HELIOSPHERIC CURRENT SHEET; FLUX-ROPES; 1 AU; IONOSPHERIC CONVECTION; GEOMAGNETIC-ACTIVITY; NONLINEAR EVOLUTION; COMPOUND STREAMS; CURRENT LOOPS AB This work discusses the relations among (1) an interplanetary force-free magnetic cloud containing a plug of cold high-density material with unusual composition, (2) a coronal mass ejection (CME), (3) an eruptive prominence, and (4) a model of prominence material supported by a force-free magnetic flux rope in a coronal streamer. The magnetic cloud moved past the Wind spacecraft located in the solar wind upstream of Earth on January 10 and 11, 1997, The magnetic field configuration in the magnetic cloud was approximately a constant-cu, force-free flux rope, The (4)He(++)/H(+) abundance in the most of the magnetic cloud was similar to that of the streamer belt material, suggesting an association between the magnetic cloud and a helmet streamer. A very cold region of exceptionally high density was detected at the rear of the magnetic cloud. This dense region had an unusual composition, including (1) a relatively high (10%) (4)He(++)/He(+) abundance (indicating a source near the photosphere), and (2) (4)He(+), with an abundance relative to (4)He(++) of similar to 1%, and the unusual charge states of O(5+) and Fe(5+) (indicating a freezing-in temperature of (1.6-4.0) x 10(5) degrees K, which is unusually low, but consistent with that expected for prominence material). Thus we suggest that the high-density region might be prominence material. The CME was seen in the solar corona on January 6, 1997, by the large angle and spectrometric coronagraph (LASCO) instrument on SOHO shortly after an eruptive prominence. A helmet streamer was observed near the latitude of the eruptive prominence a quarter of a solar rotation before and after the eruptive prominence. These observations are consistent with recent models, including the conceptual model of Low and Hundhausen [1995] for a quasi-static helmet streamer containing a force-free flux rope which supports prominence material and the dynamical model of Wu et al. [1997] for CMEs produced by the disruption of such a configuration. C1 NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94708 USA. RP Burlaga, L (reprint author), NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 82 TC 194 Z9 195 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 277 EP 285 DI 10.1029/97JA02768 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900024 ER PT J AU Gopalswamy, N Kaiser, ML Lepping, RP Kahler, SW Ogilvie, K Berdichevsky, D Kondo, T Isobe, T Akioka, M AF Gopalswamy, N Kaiser, ML Lepping, RP Kahler, SW Ogilvie, K Berdichevsky, D Kondo, T Isobe, T Akioka, M TI Origin of coronal and interplanetary shocks: A new look with WIND spacecraft data SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR RADIO-BURSTS; MASS EJECTION; LIGHT OBSERVATIONS; II BURSTS; EMISSION; PARTICLES; ACCELERATION; DISTURBANCES; PROPAGATION; EVENTS AB We have investigated type II radio bursts in the solar corona using data from ground-based radio telescopes (>18 MHz) and from the Radio and Plasma Wave experiment (WAVES) on board the WIND spacecraft (<14 MHz). The wavelength range of the WAVES experiment includes the 2- to 14-MHz band, previously unobserved from space, We found that all 34 coronal type II bursts observed over a period of 18 months (November 1, 1994, to April 30, 1996), decayed within a few solar radii and did not propagate into the interplanetary medium. On the other hand, most of the accompanying type III radio bursts observed by the ground-based instruments were observed to continue into the interplanetary medium as the electron beams propagated freely along open magnetic field lines. Over the same period of time, other instruments on board the WIND spacecraft detected about 18 interplanetary shock candidates, which seem to be unrelated to the coronal type II bursts. This result confirms the idea that the coronal and interplanetary shocks are two different populations and are of independent origin. We reexamine the data and conclusions of Gosling et al. [1976], Munro et al. [1979], and Sheeley et al. [1984] and find that their data are consistent with our result that the coronal type II bursts are due to flares, We also briefly discuss the implications of our result to the modeling studies of interplanetary shocks based on input from coronal type II radio bursts. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Phillips Lab, GPSG, Hanscom AFB, MA 01731 USA. Hughes STX Corp, Greenbelt, MD USA. Kashima Space Res Ctr, Kashima, Ibaraki 314, Japan. Hiraiso Solar Terr Res Ctr, Hitachi, Ibaraki 31112, Japan. RP Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. EM gopals@astro.umd.edu RI Gopalswamy, Nat/D-3659-2012; OI Gopalswamy, Nat/0000-0001-5894-9954 NR 49 TC 132 Z9 132 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 307 EP 316 DI 10.1029/97JA02634 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900027 ER PT J AU McDonald, FB Lal, N McGuire, RE AF McDonald, FB Lal, N McGuire, RE TI Cosmic ray recovery and solar minimum phase of solar cycle 22: An interim report SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TRANSPORT-EQUATION; DRIFT SOLUTIONS; CURRENT SHEET; HELIOSPHERE; MODULATION; RADIATION; PROPAGATION; COMPONENT; MODEL; SHOCK AB Cosmic ray observations in space now cover four successive solar minima and extend to heliocentric distances beyond 65 AU. In the outer heliosphere, comparisons between the 1996 and 1987 data show a reversal in the sign of the latitudinal gradients, smaller radial intensity gradients, and the peak in the energy spectra of anomalous H and He+ is at much lower energies but accompanied by a large reduction in their intensity at higher energies. There is also a marked difference in the cosmic ray time history over successive solar minima. Qualitatively, all of these observations are consistent with the expected effects of gradient and curvature drifts on these particles. At 1 AU the H and He spectra returned to their 1977 levels in mid-1996, and the relative comparison of the four solar minima spectra clearly show the imprint of a 22-year modulation cycle. In the outer heliosphere in 1997 the galactic and anomalous cosmic ray intensities at 51 AU are well below their peak intensities in 1987 at 42 AU (except for low-energy anomalous cosmic rays), and in fact, are comparable to the Pioneer 10 intensities at 15 AU in 1977/ 1978. The data over successive solar minima suggest that the turbulence over the solar poles plays an important role in qA > 0 epochs. In qA < 0 periods the neutral current sheet provides ready access to cosmic ray ions in the outer heliosphere, but this path becomes increasingly difficult inside similar to 20 AU. At the present time, salar minimum conditions still prevail, and there may be further increases in these energetic particle populations in the outer heliosphere. C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP McDonald, FB (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NR 29 TC 24 Z9 24 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 373 EP 379 DI 10.1029/97JA02650 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900033 ER PT J AU Shuman, CA Alley, RB Fahnestock, MA Bindschadler, RA White, JWC Winterle, J McConnell, JR AF Shuman, CA Alley, RB Fahnestock, MA Bindschadler, RA White, JWC Winterle, J McConnell, JR TI Temperature history and accumulation timing for the snowpack at GISP2, central Greenland SO JOURNAL OF GLACIOLOGY LA English DT Article ID SSM/I BRIGHTNESS TEMPERATURES; ICE-SHEET; DEUTERIUM EXCESS; ISOTOPE PROFILES; DEPTH HOAR; RECORDS; CORE; SUMMIT; TRENDS; H2O2 AB Previous research has documented a close association between high-resolution snow-pit profiles of hydrogen and oxygen stable-isotope ratios and multi-year Special Sensor Microwave/Imager (SSM/I) 37 GHz brightness temperature data in central Greenland. Comparison of the SSM/I data to profiles obtained during the 1989-91 field seasons indicated that delta D and delta(18)O data from the near-surface snow at the Greenland summit are a reliable, high-resolution temperature proxy. To test this new technique further, additional stable-isotope data were obtained from a 2 m snow pit constructed during rate-June 1995 near the GISP2 site. This new profile, supported by pit stratigraphy and chemistry data, confirms the utility of comparing stable-isotope records with SSM/I brightness temperatures. The sub-annual variation of the delta D record at the GISP2 site was determined using 15 match points, from approximately December 1991 through June 1995 and was guided in part by time-constrained hear layers. The close association of these temperature proxies supports the assertion that snow accumulation occurs frequently through the year and that the isotope record initially contains temperature information from many times of the year. This is also independently confirmed by analysis of H2O2 data. The slope of the multi-year T vs delta correlation was evaluated along with the sub-annual variation in the amount, rate and timing of accumulation. These new results are consistent with those from the previous study and they also demonstrate that the snow in this area initially contains temperature and chemical records with sub-annual resolution, This encourages confident interpretation of the paleoclimatic signal variations in the GISP2 and GRIP deep cores. C1 Penn State Univ, Ctr Earth Syst Sci, University Pk, PA 16802 USA. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Univ Maryland, Dept Meteorol, Joint Ctr Earth Syst Sci, College Pk, MD 20740 USA. NASA, Oceans & Ice Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80309 USA. Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. RI White, James/A-7845-2009; Fahnestock, Mark/N-2678-2013 OI White, James/0000-0001-6041-4684; NR 55 TC 13 Z9 13 U1 0 U2 3 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 1998 VL 44 IS 146 BP 21 EP 30 PG 10 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 105NA UT WOS:000075078600003 ER PT J AU Rignot, E MacAyeal, DR AF Rignot, E MacAyeal, DR TI Ice-shelf dynamics near the front of the Filchner-Ronne Ice Shelf, Antarctica, revealed by SAR interferometry SO JOURNAL OF GLACIOLOGY LA English DT Article ID RADAR INTERFEROMETRY; STREAM AB Fifteen synthetic aperture radar (SAR), images of the Ronne Ice Shelf (also referred to as the Filchner-Ronne Ice Shelf;, Antarctica, obtained by the European remote-sensing satellites ERS-1 and -2, are used to study ice-shelf dynamics near two ends of the iceberg-calving front. Interferograms constructed from these SAR images are used to resolve the ice-shelf displacement along several directions in response to both ocean tide and long-term creep flow. Tidal motion is separated from creep flow using differential interferometry i.e. two or more interferograms in which fringe patterns common to all are predominantly associated with creep flow. Creep-flow velocities thus determined compare well with prior ice-shelf velocity surveys. Using these data, we studied the influence of large-scale rifts, ice rises and coastal separation on the ice-shelf flow. Many of the large rifts that appeal to form the boundaries where tabular icebergs may eventually detach from the ice shelf are filled with a melange of sea ice, ice-shelf debris and wind-blown snow. The interferograms show that this melange tends to deform coherently in response to the ice-shelf flow and has sufficient strength to trap large tabular ice-shelf fragments for several decades before the fragments eventually become icebergs. In man) instances, the motion of the tabular fragments is a rigid-body rotation about a vertical asis that is driven by velocity shear within the melange. The mechanical role of the rift-filling melange ma) be to bind tabular ice-shelf fragments to the main ice shelf before they calve. This suggests two possible mechanisms by which climate could influence tabular iceberg calving. First, spatial gradients in oceanic and atmospheric temperature ma) determine where the melange melts and, thus, the location of the iceberg-calving margin. Second, melting or weakening of ice melange as a consequence of climate change could trigger a sudden or widespread release of tabular icebergs and lead to rapid ice-shelf disintegration. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Rignot, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Rignot, Eric/A-4560-2014 OI Rignot, Eric/0000-0002-3366-0481 NR 27 TC 42 Z9 42 U1 2 U2 6 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 1998 VL 44 IS 147 BP 405 EP 418 PG 14 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 143RN UT WOS:000077270400021 ER PT J AU MacAyeal, DR Rignot, E Hulbe, CL AF MacAyeal, DR Rignot, E Hulbe, CL TI Ice-shelf dynamics near the front of the Filchner-Ronne Ice Shelf, Antarctica, revealed by SAR interferometry: model/interferogram comparison SO JOURNAL OF GLACIOLOGY LA English DT Article AB We compare European remote-sensing satellite (ERS) synthetic aperture radar interferograms with artificial interferograms constructed using output of a finite-element ice-shelf flow model to study the dynamics of Filchner-Ronne Ice Shelf (FRIS), Antarctica, near Hemmen Ice Rise (HIR) where the iceberg-calving front intersects Berkner Island. We find that the model must account for rifts, mechanically competent sea ice which fills rifts, and ice softening in coastal boundary layers in order to agree with the ice-deformation pattern implied by observed interferograms. Analysis of the stress field in the model experiment that best matches the observed interferograms suggests that: (1) HIR introduces weakness into the ice shelf through the generation of large-scale rifts, and (2) the melange of sea ice and ice-shelf fragments that fills the rifts stabilizes the shelf front by providing mechanical coupling between the fractured shelf front and the adjacent coast. The rift-filling melange could melt more easily than the surrounding ice shelf and thus could represent a vulnerability of the FRIS to climate warming. C1 Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP MacAyeal, DR (reprint author), Univ Chicago, Dept Geophys Sci, 5734 S Ellis Ave, Chicago, IL 60637 USA. RI Rignot, Eric/A-4560-2014; OI Rignot, Eric/0000-0002-3366-0481; MacAyeal, Douglas/0000-0003-0647-6176 NR 12 TC 27 Z9 28 U1 1 U2 5 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 1998 VL 44 IS 147 BP 419 EP 428 PG 10 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 143RN UT WOS:000077270400022 ER PT J AU Rignot, E AF Rignot, E TI Hinge-line migration of Petermann Gletscher, north Greenland, detected using satellite-radar interferometry SO JOURNAL OF GLACIOLOGY LA English DT Article ID ICE-SHEET; ENERGY-BALANCE; ABLATION; MOTION AB The synthetic-aperture radar-interferometry technique is used to detect the migration of the limit of tidal flexing, or hinge line, of the floating ice tongue of Petermann Gletscher, a major outlet glacier of north Greenland. The hinge line is detected automatically from differential interferograms using a model-fitting technique based on an elastic-beam theory. The statistical noise of the model fit is less than 3 mm, and the hinge line is mapped with a precision of 30 m. Following automatic registration of multidate image data to a precision of 5 m, hinge-line migration is subsequently detected with a precision of 40 m in the horizontal plane across the glacier width. The results show that the hinge line of Petermann Gletscher migrates back and forth with tide by +/- 70 m, in excellent agreement with the migration calculated from ocean tides predicted by a tidal model combined with the glacier surface and basal slope measured by an ice-sounding radar. Superimposed on the short-term hinge-line migration due to tide, we detect a hinge-line retreat of 270 m in 3.87 years which varies across the glacier width by +/- 120 m. The retreat suggests glacier thinning at a rate of 78 +/- 35 cm ice a(-1) Coincidentally, an analysis of ice-volume fluxes indicates that the hinge-line ice flux of Petermann Gletscher exceeds its balance flux by 0.88 +/- 1 km(3) ice a(-1), which in turn implies glacier thinning at 83 +/- 95 cm ice a(-1) in the glacier lower reaches. Both methods therefore suggest that Petermann Gletscher is currently losing mass to the ocean. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rignot, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Rignot, Eric/A-4560-2014 OI Rignot, Eric/0000-0002-3366-0481 NR 30 TC 26 Z9 26 U1 0 U2 6 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 1998 VL 44 IS 148 BP 469 EP 476 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 170JW UT WOS:000078803400005 ER PT J AU Abdalati, W Steffen, K AF Abdalati, W Steffen, K TI Accumulation and hoar effects on microwave emission in the Greenland ice-sheet dry-snow zones SO JOURNAL OF GLACIOLOGY LA English DT Article ID SATELLITE DATA; DEPTH-HOAR; PRECIPITATION; ALASKA AB The relationships between accumulation and microwave emissivity in the dry-snow regions of the Greenland ice sheet are studied with special focus on hear formation. With the use of a discrete-ordinate radiative-transfer model, the relative contributions of hear and accumulation to microwave emission are examined. The results show that the link between microwave emission and accumulation rates in the dry-snow area of the Greenland ice sheet is significant; however, the emissivity is also dependent on the extent of boar development. As a result, accumulation estimates based on passive microwave observations in the low-accumulation dry-snow areas will require successful parameterization of hear formation. Furthermore, the increasing Tb trends that were observed during the 1980s, which have been hypothesized to be related to accumulation changes, may be strongly related to variations in hoar development. Other possible explanations for these observed trends, such as slight surface melt or atmospheric conditions, are also discussed. C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Ctr Study Earth Space, Boulder, CO 80309 USA. RP Abdalati, W (reprint author), NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RI Steffen, Konrad/C-6027-2013 OI Steffen, Konrad/0000-0001-8658-1026 NR 37 TC 22 Z9 22 U1 0 U2 0 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 1998 VL 44 IS 148 BP 523 EP 531 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 170JW UT WOS:000078803400010 ER PT J AU Thomas, RH Csatho, BM Gogineni, S Jezek, FC Kuivinen, K AF Thomas, RH Csatho, BM Gogineni, S Jezek, FC Kuivinen, K TI Thickening of the western part of the Greenland ice sheet SO JOURNAL OF GLACIOLOGY LA English DT Article AB NASA's Program for Arctic Regional Climate Assessment (PARCA) includes measurements of ice velocity and ice thickness along the 2000 m clevation contour line in the western part of the ice sheet. Here we use these measurements together with published estimates of snow-accumulation rates to infer the mass balance, or rate of thickening/thinning, of the ice-sheet catchment area inland fi om the velocity traverse. Within the accuracy to which we know snow-accumulation rates, the entire area is in balance, but localized regions inland from Upernavik Isstrom and Jakobshavn Isbrae both appear to be thickening by about 10 cm a(-1). C1 NASA, Code YS, Washington, DC 20546 USA. Ohio State Univ, Byrd Polar Res Ctr, Columbus, OH 43210 USA. Univ Nebraska, Polar Ice Coring Off, Lincoln, NE 68588 USA. RP Thomas, RH (reprint author), EG&G, 900 Clopper Rd,Suite 200, Gaithersburg, MD USA. NR 14 TC 24 Z9 24 U1 0 U2 2 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 1998 VL 44 IS 148 BP 653 EP 658 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 170JW UT WOS:000078803400021 ER PT J AU Chatterji, GB Menon, PK Sridhar, B AF Chatterji, GB Menon, PK Sridhar, B TI Vision-based position and attitude determination for aircraft night landing SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article AB An image based method for the determination of aircraft position and yaw and pitch orientations with respect to the runway during night landing is described. Information derived from a model of the airport lights together with video images acquired by an onboard video camera and roil attitude angle sensed with a roll sensor are integrated in a Kalman filtering algorithm. Simulation results are presented to demonstrate the feasibility of the proposed concept. C1 Sterling Software, Moffett Field, CA 94035 USA. Optimal Synth, Palo Alto, CA 94306 USA. NASA, Ames Res Ctr, AFC Branch, Moffett Field, CA 94035 USA. Santa Clara Univ, Santa Clara, CA 95053 USA. RP Chatterji, GB (reprint author), Sterling Software, Moffett Field, CA 94035 USA. NR 19 TC 9 Z9 10 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 1998 VL 21 IS 1 BP 84 EP 92 DI 10.2514/2.4201 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA YR201 UT WOS:000071470900013 ER PT J AU Molls, T Zhao, G Molls, F AF Molls, T Zhao, G Molls, F TI Friction slope in depth-averaged flow SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article ID OPEN-CHANNEL FLOW; UNSTEADY-FLOW; MODEL; COMPUTATION AB Due to the manner in which the friction slope S-f is calculated, many two-dimensional (2D) depth-averaged models include only bottom friction. Specifically, 2D depth-averaged models that assume vertical channel sidewalls and utilize free-slip boundary conditions do not account for the friction due to the channel sidewalls. The principal intent of this paper is to inform modelers of this largely neglected issue, establish the validity of the aforementioned statement, and introduce a strategy for alleviating the problem. First, the relevant equations are presented. Based on these equations, the problem is clearly explained and interpreted. Further illustration is provided by analyzing a backwater profile in a straight rectangular channel. The one-dimensional (1D) and 2D computed results are compared with Lansford and Mitchell's experimental data. The 2D numerical solution does not coincide with the experimental data unless the 2D friction slope equation is modified to account for sidewall friction. C1 So Illinois Univ, Dept Civil Engn, Carbondale, IL 62901 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Molls, T (reprint author), So Illinois Univ, Dept Civil Engn, Carbondale, IL 62901 USA. NR 21 TC 8 Z9 8 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD JAN PY 1998 VL 124 IS 1 BP 81 EP 85 DI 10.1061/(ASCE)0733-9429(1998)124:1(81) PG 5 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA YL684 UT WOS:000070981300011 ER PT J AU Titli, A AF Titli, A TI Preface SO JOURNAL OF INTELLIGENT & FUZZY SYSTEMS LA English DT Editorial Material C1 Univ New Mexico, NASA, ACE Ctr, Albuquerque, NM 87131 USA. RP Titli, A (reprint author), Univ New Mexico, NASA, ACE Ctr, Albuquerque, NM 87131 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOS PRESS PI AMSTERDAM PA VAN DIEMENSTRAAT 94, 1013 CN AMSTERDAM, NETHERLANDS SN 1064-1246 J9 J INTELL FUZZY SYST JI J. Intell. Fuzzy Syst. PY 1998 VL 6 IS 3 BP 279 EP 279 PG 1 WC Computer Science, Artificial Intelligence SC Computer Science GA 145FP UT WOS:000077360600001 ER PT J AU Hammonds, TG Goodwin, TJ Navar, GL Goda, FO Campbell, WC Verroust, PJ Kaysen, JH AF Hammonds, TG Goodwin, TJ Navar, GL Goda, FO Campbell, WC Verroust, PJ Kaysen, JH TI Epithelial cell gene expression is shear responsive SO JOURNAL OF INVESTIGATIVE MEDICINE LA English DT Meeting Abstract C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Tulane Univ, Sch Med, VA Med Ctr, New Orleans, LA 70112 USA. INSERM U64, Paris, France. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SLACK INC PI THOROFARE PA 6900 GROVE RD, THOROFARE, NJ 08086 USA SN 1081-5589 J9 J INVEST MED JI J. Invest. Med. PD JAN PY 1998 VL 46 IS 1 BP 44A EP 44A PG 1 WC Medicine, General & Internal; Medicine, Research & Experimental SC General & Internal Medicine; Research & Experimental Medicine GA YU124 UT WOS:000071684700233 ER PT J AU Rubira, AF Rancourt, JD Taylor, LT Stoakley, DM Clair, AKS AF Rubira, AF Rancourt, JD Taylor, LT Stoakley, DM Clair, AKS TI Chemical factors that influence the production of conductive and/or reflective silver-doped polyimide films SO JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY LA English DT Article DE polyimide; silver; reflectivity; conductivity ID METAL; POLYMERS AB Doping a poly(amide acid) resin with a silver containing additive (1,5-cyclooctadiene-hexafluoroacetylacetonato)-silver(I) [Ag(COD) (HFA)I resulted, after thermal cure, in either a highly reflective or highly electrically conductive polyimide film. The combination of monomers, which render films with low T-g (similar to 210 degrees C), and contained sulfur, produced films with surface resistance in the range 10(1)-10(3) ohms. On the other hand, films with specular reflectivity (relative to a silver mirror) in the range of 65-48% were obtained using both high T-g polyimides and polyimides void of sulfur in the polyimide backbone with low T-g Our understanding regarding the structure-property relationship on these polyimide films and also the characterization of the doped-films are discussed. C1 Univ Estadual Maringa, Dept Quim, BR-87020900 Maringa, Parana, Brazil. Virginia Polytech Inst & State Univ, Dept Chem, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Div Mat, Hampton, VA 23665 USA. RP Rubira, AF (reprint author), Univ Estadual Maringa, Dept Quim, Av Colombo 5790, BR-87020900 Maringa, Parana, Brazil. NR 22 TC 27 Z9 31 U1 1 U2 2 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1060-1325 J9 J MACROMOL SCI PURE JI J. Macromol. Sci.-Pure Appl. Chem. PY 1998 VL A35 IS 4 BP 621 EP 636 DI 10.1080/10601329808002001 PG 16 WC Polymer Science SC Polymer Science GA ZG863 UT WOS:000073047600006 ER PT J AU Zhao, PQ AF Zhao, PQ TI Realization and theoretical limits of the spectral resolution in double Fourier interferometric imaging with an optical telescope array SO JOURNAL OF MODERN OPTICS LA English DT Article AB The realization and theoretical limits of the spectral resolution in double Fourier interferometric imaging (DFII) with a phase telescope array are presented. The realization and the effects of optical path difference (OPD) modulations are discussed. Two basic requirements for OPD modulations must be met in the design and operation of a double Fourier interferometer: symmetric OPD modulations about zero OPD and identical OPD modulations at all the available spatial frequencies. The Gibbs phenomenon due to OPD modulations affects the source's spectral brightness distribution, but, for a point source, not the complex visibility. Theoretically, without loss in spatial image fidelity, it is not possible to perform DFII with a telescope array when the aperture synthesis is done only by the Earth's rotation. In practice, DFII can be realized under approximation. In this case, relations between the spectral resolution, the interferometer's parameters and the observed star's parameters are derived. For a two-aperture interferometer with an east-west baseline of 100 m and telescope diameter of 8 m, the spectral resolution is limited to several thousands or less for a star having a magnitude of five, six or fainter, a field of view equal to or larger than the Airy disc of the diffraction pattern of the single telescope aperture and a signal-to-noise ratio of three in the interferogram. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Zhao, PQ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 306-388, Pasadena, CA 91125 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD JAN PY 1998 VL 45 IS 1 BP 51 EP 67 PG 17 WC Optics SC Optics GA YR883 UT WOS:000071541000008 ER PT J AU Chipot, C Pohorille, A AF Chipot, C Pohorille, A TI Conformational equilibria of terminally blocked single amino acids at the water-hexane interface. A molecular dynamics study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NEUTRAL LIPID-MEMBRANES; ALANINE DIPEPTIDE; MONTE-CARLO; FREE-ENERGY; AQUEOUS-SOLUTION; DYNORPHIN A-(1-13)-TRIDECAPEPTIDE; COMPUTER-SIMULATION; SECONDARY STRUCTURE; BILAYER INTERFACE; SIGNAL PEPTIDES AB The conformational equilibria of the acetyl and methyl amide terminally blocked L-alanine, L-leucine and L-glutamine amino acids are examined in vacuum, in bulk water, and at the water-hexane interface, using multi-nanosecond molecular dynamics simulations. The two-dimensional probability distribution functions of finding the peptides at different dihedral angles of the backbone, phi and psi, are calculated, and free energy differences between different conformational states are determined. All three peptides are interfacially active, i.e. tend to accumulate at the interface even though they are not amphiphilic. Conformational states stable in both gas phase and water are also stable in the interfacial environment. Their populations, however, cannot be simply predicted from the knowledge of conformational equilibria in the bulk phases, indicating that the interface exerts a unique effect on the peptides. Conformational preferences in the interfacial environment arise from the interplay between electrostatic and hydrophobic effects. As in an aqueous solution, electrostatic solute-solvent interactions lead to the stabilization of more polar peptide conformations. The hydrophobic effect is manifested at the interface by a tendency to segregate polar and nonpolar moieties of the solute into the aqueous and the hexane phases, respectively. For the terminally blocked glutamine, this favors conformations for which such a segregation is compatible with the formation of strong, backbone-side chain intramolecular hydrogen bonds on the hexane side of the interface. The influence of the hydrophobic effect can be also noted in the orientational preferences of the peptides at the interface. The terminally blocked leucine is oriented such that its nonpolar side chain is buried in hexane, whereas the polar side chain of glutamine is immersed in water. The free energies of rotating the peptides along the axis parallel to the interface by more than 90 degrees are substantial. This indicates that peptide folding at interfaces is strongly driven by the tendency to adopt amphiphilic structures. C1 NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. RP NASA, Ames Res Ctr, Exobiol Branch, MS 239-4, Moffett Field, CA 94035 USA. NR 68 TC 33 Z9 34 U1 3 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 1 PY 1998 VL 102 IS 1 BP 281 EP 290 DI 10.1021/jp970938n PG 10 WC Chemistry, Physical SC Chemistry GA YP851 UT WOS:000071322200040 PM 11541119 ER PT J AU Caillat, T AF Caillat, T TI Preparation and thermoelectric properties of some arsenopyrite phases based on RuSb2-2xTe2x and RuSb2-2xSe2x solid solutions SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE intermetallic compounds; semiconductors; transport properties AB The synthesis and some properties of several arsenopyrite phases based on RuSb2-2xTe2x and RuSb2. Se-2x(2x) solid solutions is reported. The existence of solid solutions with the arsenopyrite structure in the RuSb22 degrees (x over tilde)Te-2x system for 0.25 < x < 0.65 was confirmed. In the RuSb2-2xSe2x system, no series of solid solutions was found, and only the RuSbSe phase was prepared in single phase form. In an effort to assess the potential of these materials for thermoelectric applications; electrical resistivity, Seebeck coefficient, and thermal conductivity were measured between 300 and 1000 K. Low thermal conductivity values were achieved for the ternary and quaternary compositions investigated, about five times lower than those obtained for binary compounds such as IrSb2 and CoSb2 at room temperature. In these materials, scattering of the phonons by electrons transferred between mixed valence ions accounts for the low thermal conductivity observed. Despite these low values, the samples are characterized by low carrier mobility and high electrical resistivity values, resulting in thermoelectric figures of merit lower than state-of-the-art thermoelectric materials. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Caillat, T (reprint author), CALTECH, Jet Prop Lab, MS 277-207,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 1 Z9 1 U1 4 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD JAN PY 1998 VL 59 IS 1 BP 61 EP 67 DI 10.1016/S0022-3697(97)00135-2 PG 7 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA YR514 UT WOS:000071502900010 ER PT J AU Stoner, AW Smith, NP AF Stoner, AW Smith, NP TI Across-shelf transport of gastropod larvae in the central Bahamas: rapid responses to local wind conditions SO JOURNAL OF PLANKTON RESEARCH LA English DT Article ID QUEEN CONCH; VERTICAL MIGRATION; CANCER-MAGISTER; STROMBUS-GIGAS; DUNGENESS CRAB; FLORIDA KEYS; BLUE CRABS; RECRUITMENT; ABUNDANCE; OFFSHORE AB Surveys for veliger larvae of the large gastropods Strombus gigas and Strombus costatus were carried out in duplicate transects running offshore (0.26-5 km) from Lee Stocking Island, Exuma Cays, Bahamas. The across-shelf distribution of the larvae during the 1991 spawning season was highly variable over periods of 3-6 days. Larvae of both species are known to inhabit the upper few meters of the water column, and analysis of wind stress patterns over the study period showed that across-shelf distribution of the larvae was affected by wind forcing. Seaward (recruitment-unfavorable) transport near Lee Stocking Island was most highly correlated with wind stress toward the north-northwest (335-357 degrees). The resultant wind stress during the study was toward 279 degrees, suggesting that recruitment of conch to nursery grounds on the Great Bahama Bank in the Exuma Cays occurs under anomalous summer wind conditions. The correlation between the across-shelf distribution of conch veligers and wind stress was highest with extinction coefficients of 0.17-0.23 in the exponentially filtered wind stress. This indicates that larval distribution over the 5-km-long transects responded rapidly to changes in wind stress. Over 75% of the effective wind stress occurred over just 6-8 h preceding collections; therefore, short-term changes in wind stress, such as afternoon strengthening of the trade winds, may have a significant influence on across-shelf larval transport. C1 Caribbean Marine Res Ctr, Vero Beach, FL 32963 USA. Harbor Branch Oceanog Inst Inc, Ft Pierce, FL 34946 USA. RP Stoner, AW (reprint author), NOAA, NE Fisheries Sci Ctr, Natl Marine Fisheries Serv, 74 Magruder Rd, Highlands, NJ 07732 USA. NR 38 TC 11 Z9 11 U1 1 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD JAN PY 1998 VL 20 IS 1 BP 1 EP 16 DI 10.1093/plankt/20.1.1 PG 16 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA YZ282 UT WOS:000072238800001 ER PT J AU Yungster, S Radhakrishnan, K Rabinowitz, MJ AF Yungster, S Radhakrishnan, K Rabinowitz, MJ TI Reacting flow establishment in ram accelerators: A numerical study SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID PROJECTILES; COMBUSTION; GASES AB The temporal evolution of the combustion process that is established during projectile transition from the launch tube into the ram accelerator section containing an explosive hydrogen-oxygen-argon gas mixture is examined. The Navier-Stokes equations for chemically reacting flow are solved in a fully coupled manner, using an implicit, time-accurate algorithm. The solution procedure is based on a spatially second order, total variation diminishing scheme and a temporally second order, variable-step, backward differentiation formula method. The hydrogen-oxygen-argon chemistry is modeled with a nine-species, 19-step reaction mechanism. Results of the numerical simulations are presented for two representative cases. We study the temporal developments of shock-induced combustion and thrust farce. Positive thrust occurs in both ram accelerator configurations presented; however, combustion in the boundary layer enhances its separation, ultimately resulting in unstart. C1 NASA, Lewis Res Ctr, Inst Computat Mech, Cleveland, OH 44135 USA. NASA, Lewis Res Ctr, Internal Fluid Mech Div, Cleveland, OH 44135 USA. RP Yungster, S (reprint author), NASA, Lewis Res Ctr, Inst Computat Mech, Cleveland, OH 44135 USA. NR 34 TC 6 Z9 6 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1998 VL 14 IS 1 BP 10 EP 17 DI 10.2514/2.5259 PG 8 WC Engineering, Aerospace SC Engineering GA YR361 UT WOS:000071487700002 ER PT J AU Matz, E Appelbaum, J Taitel, Y AF Matz, E Appelbaum, J Taitel, Y TI Solar cell temperature on Mars SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID RADIATION AB Missions to the Martian surface will require electric power, Of the several possibilities, photovoltaic power system can offer many advantages. Photovoltaic cell performance increases with decreasing temperatures. The present paper deals with the calculation of the operating temperature of a flexible photovoltaic array needed for the determination of the electric output power from the array, The diurnal temperature variation was determined based on the solution of the heat-balance equation considering radiation, free and forced convection, and conduction. The photovoltaic array was divided into three layers (cover glass, solar cells, and substrate), for which three differential equations were obtained and solved. The solution takes into account the special atmospheric condition prevailing on Mars, considering the diurnal variation of the ambient and surface temperatures, diurnal variation of direct beam, diffuse and albedo irradiances, variation of wind speed, and variation of various Mars atmospheric parameters with temperature. C1 Tel Aviv Univ, Dept Elect Engn Syst, IL-69978 Tel Aviv, Israel. NASA, Lewis Res Ctr, Photovoltaic & Space Environm Branch, Cleveland, OH 44135 USA. RP Matz, E (reprint author), Tel Aviv Univ, Dept Elect Engn Syst, POB 39040, IL-69978 Tel Aviv, Israel. NR 15 TC 7 Z9 7 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1998 VL 14 IS 1 BP 119 EP 125 DI 10.2514/2.5257 PG 7 WC Engineering, Aerospace SC Engineering GA YR361 UT WOS:000071487700016 ER PT J AU Landis, GA AF Landis, GA TI Mars dust-removal technology SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT 32nd Intersociety Energy Conversion Engineering Conference (IECEC-97) CY JUL 27-AUG 02, 1997 CL HONOLULU, HAWAII SP Amer Inst Chem Engineers, Amer Nucl Soc, SAE Int, AIAA, ASME, IEEE AB The Mars atmosphere contains a significant load of suspended dust. Settling of atmospheric dust onto the surface of the solar array is potentially a lifetime-limiting faster for a power system on any Mars mission, For long-term operation of arrays on Mars, it may be necessary to develop techniques to remove deposited dust, Dust is expected to adhere to the array by Van der Waals adhesive forces, These forces are quite strong at the dust particle sizes expected, If the array surface is insulating, it is possible that they may also be subject to electrostatic adhesion, which may be extremely strong, Dust-removal methods must overcome this force, Dust-removal methods can be categorized briefly into four categories: natural, mechanical, electromechanical, and electrostatic. The environment of Mars is expected to be an ideal one for the use of electrostatic dust-removal techniques. C1 Ohio Aerosp Inst, Cleveland, OH 44135 USA. RP Landis, GA (reprint author), NASA, Lewis Res Ctr, M-S 302-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 19 TC 18 Z9 20 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1998 VL 14 IS 1 BP 126 EP 128 DI 10.2514/2.5258 PG 3 WC Engineering, Aerospace SC Engineering GA YR361 UT WOS:000071487700017 ER PT J AU Zhang, Z Aglan, H Faughnan, P Bryan, C AF Zhang, Z Aglan, H Faughnan, P Bryan, C TI Fracture and fatigue analysis of 15% chopped glass fiber reinforced PTFE SO JOURNAL OF REINFORCED PLASTICS AND COMPOSITES LA English DT Article ID RUBBER COMPOUNDS; PROPAGATION AB The fracture and fatigue behavior of 15% chopped glass fiber reinforced PTFE was studied. Two fracture regions were observed with the static tensile failure of this material. Torn ligament bundles, pulled out fibers and microfibrillation are the fracture surface features associated with the first region, These features were responsible for the initial slow crack observed during tensile loading, The second region was characterized by a smoother surface with little damage associated features resulting in an unstable crack propagation, The Modified Crack Layer Model was used to analyze the fatigue crack propagation behavior of the material. The fatigue fracture surface of the 15% glass fiber reinforced PTFE showed three distinct regions. These regions were comparable in location with the three stages of fatigue crack propagation (FCP) kinetics of this material. A large number of torn fracture ligaments and long fibrils were observed in the first region, which is associated with the threshold state of FCP. Extensive random fibrillation was found in the second fracture region which was associated with the second stage of FCP kinetics (stage of reduced acceleration), Undrawn matrix, very little fibrillation and a smooth surface were the fracture surface features of the third region, This region was associated with the third stage. unstable crack propagation, of FCP kinetics. C1 Tuskegee Univ, Dept Mech Engn, Tuskegee, AL 36088 USA. NASA, Kennedy Space Ctr, Kennedy Space Ctr, FL USA. RP Aglan, H (reprint author), Tuskegee Univ, Dept Mech Engn, Tuskegee, AL 36088 USA. NR 16 TC 15 Z9 24 U1 0 U2 2 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0731-6844 J9 J REINF PLAST COMP JI J. Reinf. Plast. Compos. PY 1998 VL 17 IS 8 BP 752 EP 771 PG 20 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA ZP710 UT WOS:000073780700006 ER PT J AU Breivik, NL Hyer, MW AF Breivik, NL Hyer, MW TI Buckling and postbuckling behavior of curved composite panels due to thermal and mechanical loading SO JOURNAL OF REINFORCED PLASTICS AND COMPOSITES LA English DT Article AB The buckling and postbuckling responses of unstiffened cylindrically curved composite panels are studied using the finite element code STAGS and a geometrically nonlinear Rayleigh-Ritz solution. Loading is either through axial end-shortening at a fixed spatially uniform temperature, or it is temperature-induced due to the thermal stresses that arise when the spatially uniform temperature is increased while axial end displacement is restrained to be zero. Comparisons are made between two sets of boundary conditions and three laminates. Buckling and postbuckling responses are found to be strongly dependent on material orthotropy and are substantially affected by the amount of circumferential restraint along the straight edge boundaries. C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Natl Res Council, Hampton, VA 23681 USA. RP Hyer, MW (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NR 12 TC 0 Z9 0 U1 0 U2 2 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0731-6844 J9 J REINF PLAST COMP JI J. Reinf. Plast. Compos. PY 1998 VL 17 IS 14 BP 1292 EP 1306 PG 15 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 114DZ UT WOS:000075595000004 ER PT J AU Lanzerotti, LJ Rinnert, K Carlock, D Sobeck, CK Dehmel, G AF Lanzerotti, LJ Rinnert, K Carlock, D Sobeck, CK Dehmel, G TI Spin rate of Galileo probe during descent into the atmosphere of Jupiter SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article C1 AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. Hughes Space & Commun Co, Spacecraft Engn Operat, El Segundo, CA 90009 USA. NASA, Ames Res Ctr, Space Projects Div, Moffett Field, CA 94035 USA. Tech Univ Braunschweig, D-38106 Braunschweig, Germany. RP Lanzerotti, LJ (reprint author), AT&T Bell Labs, Lucent Technol, 600 Mt Ave, Murray Hill, NJ 07974 USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 1998 VL 35 IS 1 BP 100 EP 102 PG 3 WC Engineering, Aerospace SC Engineering GA YW492 UT WOS:000071941100013 ER PT J AU Merceret, FJ AF Merceret, FJ TI Risk assessment consequences of the lognormal distribution of midtropospheric wind changes SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article C1 NASA, Kennedy Space Ctr, Appl Meteorol Unit, Kennedy Space Ctr, FL 32899 USA. RP Merceret, FJ (reprint author), NASA, Kennedy Space Ctr, Appl Meteorol Unit, PH-B3, Kennedy Space Ctr, FL 32899 USA. NR 4 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 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 1998 VL 35 IS 1 BP 111 EP 112 PG 2 WC Engineering, Aerospace SC Engineering GA YW492 UT WOS:000071941100018 ER PT J AU Desai, PN Braun, RD Powell, RW Engelund, WC Tartabini, PV AF Desai, PN Braun, RD Powell, RW Engelund, WC Tartabini, PV TI Comment on "Six-degree-of-freedom entry dispersion analysis for the METEOR recovery module" - Reply by the authors to T. McCusker SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Editorial Material C1 NASA, Langley Res Ctr, Space Syst & Concepts Div, Hampton, VA 23681 USA. RP Desai, PN (reprint author), NASA, Langley Res Ctr, Space Syst & Concepts Div, Hampton, VA 23681 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 1998 VL 35 IS 1 BP 117 EP 118 PG 2 WC Engineering, Aerospace SC Engineering GA YW492 UT WOS:000071941100022 ER PT J AU Layne, CS McDonald, PV Mulavara, AP Bloomberg, JJ AF Layne, CS McDonald, PV Mulavara, AP Bloomberg, JJ TI Adaptations in movement control after space flight SO JOURNAL OF SPORT & EXERCISE PSYCHOLOGY LA English DT Meeting Abstract C1 Univ Houston, Dept Hlth & Human Performance, Houston, TX USA. Natl Space Biomed Res Inst, Houston, TX USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HUMAN KINETICS PUBL INC PI CHAMPAIGN PA 1607 N MARKET ST, CHAMPAIGN, IL 61820-2200 USA SN 0895-2779 J9 J SPORT EXERCISE PSY JI J. Sport Exerc. Psychol. PY 1998 VL 20 SU S BP S32 EP S32 PG 1 WC Hospitality, Leisure, Sport & Tourism; Psychology, Applied; Psychology; Sport Sciences SC Social Sciences - Other Topics; Psychology; Sport Sciences GA 130WT UT WOS:000076543900064 ER PT J AU Harris, FD Scully, MP AF Harris, FD Scully, MP TI Rotorcraft cost too much SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article AB The rotorcraft industry is pricing itself right out of the commercial transportation marketplace, This is illustrated by helicopter prices that have inflated significantly faster than consumer product prices and by helicopter productivity per dollar that decreases with increased purchase price, Specifically, inflation in helicopter purchase price has significantly exceeded the U.S. consumer price index since 1980, When measured in ton-knots, productivity per 1994 purchase price dollar has diminished with increased size, cruise speed and added features. In sharp contrast, the propeller driven, fixed wing airliner industry has not followed the rotorcraft industry in this unsatisfactory trend. Purchase price analysis of 120 helicopters using linear regression statistical analysis has yielded a price estimating equation, This equation shows helicopter prices are more sensitive to installed power than to weight empty, Inclusion of 126 General Aviation aircraft and 163 airliners in the regression analysis has shown that price is linearly dependent on a size factor, This pseudo, universal size factor contains both weight empty and total engine(s) rated horsepower design parameters, At equal size factor, helicopters are priced about 50 percent higher than airplanes in the commercial marketplace, This appears to be the premium for vertical takeoff and landing capability, Preliminary price and performance data for two emerging tiltrotors show that the helicopter's low cruise speed problem has been solved. The rotorcraft industry can now expand into the airliner marketplace if it can substantially reduce the premium price for VTOL. The traditional minimum weight empty design approach results in excessive installed power due to high disc loading, The design approach has been necessary to meet military requirements such as fitting helicopters inside an Air Force C-130 and operating tiltrotors from a Navy ship, This military oriented design approach is wrong for commercial products, The price estimating relationship developed shows that designing for minimum weight empty does not equate to minimum helicopter purchase price for the commercial operator, Continuing a military oriented design approach for advanced commercial products such as civil tiltrotors is not recommended. C1 FD Harris & Associates, Fountain Hills, AZ 85268 USA. NASA, Ames Res Ctr, Aeroflightdynam Directorate, Moffett Field, CA 94035 USA. RP Harris, FD (reprint author), FD Harris & Associates, Fountain Hills, AZ 85268 USA. NR 10 TC 1 Z9 2 U1 0 U2 1 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JAN PY 1998 VL 43 IS 1 BP 3 EP 13 PG 11 WC Engineering, Aerospace SC Engineering GA YV227 UT WOS:000071802100001 ER PT J AU Schmitz, FH AF Schmitz, FH TI Reduction of blade-vortex interaction (BVI) noise through X-force control SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article ID HELICOPTER AB Momentum theory and the longitudinal force balance equations of a single rotor helicopter are used to develop simple expressions to describe tip-path-plane tilt and uniform Inflow to the rotor. The uniform inflow is adjusted to represent the inflow at certain azimuthal locations where strong Blade-Vortex Interaction (BVI) is likely to occur. This theoretical model is then used to describe the flight conditions where BVI is likely to occur and to explore those flight variables that can be used to minimize BVI noise radiation. A separate X-force control is introduced to help minimize BVI noise. Several methods of generating the X-force are presented that can be used to alter the inflow to the rotor and thus increase the likelihood of avoiding BVI during approaches to a landing. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Schmitz, FH (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 17 TC 11 Z9 12 U1 0 U2 0 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JAN PY 1998 VL 43 IS 1 BP 14 EP 24 PG 11 WC Engineering, Aerospace SC Engineering GA YV227 UT WOS:000071802100002 ER PT J AU Esler, SL Nelson, ML AF Esler, SL Nelson, ML TI Evolution of scientific and technical information distribution SO JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE LA English DT Article; Proceedings Paper CT 4th International Conference on Science and Technology Indicators CY OCT 05-07, 1995 CL ANTWERP, BELGIUM SP Minist Flemish Community, Sci Policy Programming Adm, Netherlands Minist Educ Sci & Cultural Affairs AB World Wide Web (WWW) and related information technologies are transforming the distribution of scientific and technical information (STI), We examine 11 recent, functioning digital libraries focusing on the distribution of STI publications, including journal articles, conference papers, and technical reports. We introduce 4 main categories of digital library projects: Based on the architecture (distributed vs, centralized) and the contributor (traditional publisher vs. authoring individual/organization). Many digital library prototypes merely automate existing publishing practices or focus solely on the digitization of the publishing cycle output, not sampling and capturing elements of the input. Still others do not consider for distribution the large body of "gray literature." We address these deficiencies in the current model of STI exchange by suggesting methods for expanding the scope and target of digital libraries by focusing on a greater source of technical publications and using "buckets," an object-oriented construct for grouping logically related information objects, to include holdings other than technical publications. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Esler, SL (reprint author), NASA, Langley Res Ctr, MS 158, Hampton, VA 23681 USA. OI Nelson, Michael/0000-0003-3749-8116 NR 40 TC 10 Z9 10 U1 1 U2 5 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0002-8231 J9 J AM SOC INFORM SCI JI J. Am. Soc. Inf. Sci. PD JAN PY 1998 VL 49 IS 1 BP 82 EP 91 PG 10 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA YM282 UT WOS:000071048000010 ER PT J AU Woodard, SE Nagchaudhuri, A AF Woodard, SE Nagchaudhuri, A TI Application of least mean square algorithms to spacecraft vibration compensation SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article; Proceedings Paper CT 5th Annual AAS/AIAA Space Flight Mechanics Conference CY FEB 13-16, 1995 CL ALBUQUERQUE, NEW MEXICO SP Amer Astronaut Soc, AIAA ID LMS AB This paper describes the application of the Least Mean Square (LMS) algorithm in tandem with the Filtered-X Least Mean Square algorithm for controlling a science instrument's line-of-sight pointing. Pointing error is caused by a periodic disturbance and spacecraft vibration. A least mean square algorithm is used on-orbit to produce the transfer function between the instrument's servo-mechanism and error sensor. The result is a set of adaptive transversal filter weights tuned to the transfer function. The Filtered-X LMS algorithm, which is an extension of the LMS, tunes a set of transversal filter weights to the transfer function between the disturbance source and the servo-mechanism's actuation signal. The servo-mechanism's resulting actuation counters the disturbance response and thus maintains accurate science instrumental pointing. A simulation model of the Upper Atmosphere Research Satellite is used to demonstrate the algorithms. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. Duke Univ, Durham, NC 27706 USA. RP Woodard, SE (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD JAN-MAR PY 1998 VL 46 IS 1 BP 83 EP 90 PG 8 WC Engineering, Aerospace SC Engineering GA 152BH UT WOS:000077755200005 ER PT J AU Bergen, TF Himelblau, H Kern, DL AF Bergen, TF Himelblau, H Kern, DL TI Development of acoustic test criteria for the Cassini spacecraft SO JOURNAL OF THE IEST LA English DT Article DE Cassini spacecraft; Titan IV; payload fairing; flight acoustic data; acoustic test criteria; acoustic blankets; reverberant acoustic test; vibroacoustics AB Acoustic measurements from eight Titan IV flights, and an acoustic test of a Cassini simulator and Titan payload fairing (PLF), were used to derive acoustic flight and test criteria for the Cassini spacecraft. The flight and laboratory data were used or modified to account for the following factors: (a) noise-spike contamination of flight data, (b) spatial and flight-to-flight variations of flight data, (c) application of a thicker barrier-blanket to the PLF for the Cassini mission, (d) effects of locating two Cassini assemblies, the Huygens Probe (HP), and the High Gain Antenna (HGA), near the PLF, and (e) higher thrust of upgraded Titan solid rocket motors (SRMs) for the Cassini mission. An overall sound pressure level of 145 dB was verified for the protoflight acoustic test criteria for the Cassini spacecraft. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Bergen, TF (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 23 TC 5 Z9 5 U1 0 U2 0 PU INST ENVIRONMENTAL SCI TECHNOLOGY PI MT PROSPECT PA 940 E NORTHWEST HIGHWAY, MT PROSPECT, IL 60056 USA SN 1052-2883 J9 J IEST JI J. IEST PD JAN-FEB PY 1998 VL 41 IS 1 BP 26 EP 38 PG 49 WC Engineering, Environmental; Environmental Sciences; Instruments & Instrumentation SC Engineering; Environmental Sciences & Ecology; Instruments & Instrumentation GA ZH871 UT WOS:000073155800007 ER PT J AU Barnes, NP Murray, KE Jani, MG Schunemann, PG Pollak, TM AF Barnes, NP Murray, KE Jani, MG Schunemann, PG Pollak, TM TI ZnGeP2 parametric amplifier SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID MU-M; AGGASE2; AMPLIFICATION; THRESHOLD AB A ZnGeP2 parametric amplifier was constructed, and the small-signal gain of a 3.39-mu m He-Ne laser in excess of 10 was measured. With a 2.06-mu m Ho:Tm:Er:YLF laser having a nominal 50-ns pulse length as a pump, small-signal gain was measured as a function of pump power. When compared with the predicted gain, taking into account the beam profile of both the pump and the signal, good agreement was found at low pump powers. However, the observed gain was less than predicted at higher pump powers. Pump-induced loss at 3.39 mu m, a phenomenon not observed in other nonlinear crystals such as AgGeSe2, causes the difference. Pump-induced loss was observed when the ZnGeP2 crystal was tilted away from the phase-matching angle. Pump-induced loss at 3.39 mu m was characterized and found to be directly proportional to the pump energy. (C) 1998 Optical Society of America. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sci & Technol Corp, Hampton, VA 23666 USA. Lockheed Sanders, Nashua, NH 03061 USA. RP Barnes, NP (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 18 TC 31 Z9 35 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JAN PY 1998 VL 15 IS 1 BP 232 EP 238 DI 10.1364/JOSAB.15.000232 PG 7 WC Optics SC Optics GA YT825 UT WOS:000071648800030 ER PT J AU Cunnington, GR Lee, SC White, SM AF Cunnington, GR Lee, SC White, SM TI Radiative properties of fiber-reinforced aerogel: Theory versus experiment SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article ID SILICA AEROGEL; FIBROUS MEDIA; ORIENTATION AB This paper presents a theory and its validation by experiment for the radiative properties of high-porosity silica aerogels that contain randomly oriented and uniformly dispersed fibers. The formulations for the fiber radiative properties are based on fundamental principles, for which parameters defining the material composition are the only required inputs. The predicted spectral transmittance and reflectance for collimated irradiation from the solution of the radiative transfer equation are compared with the measured values. The validity of the theoretical model is established by the good agreement between the predictions and experimental data for various specimens that contain different fiber types, fiber and aerogel solid volume fractions, and specimen thicknesses. C1 Appl Sci Lab Inc, Hacienda Hts, CA 91745 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Cunnington, GR (reprint author), Appl Sci Lab Inc, Hacienda Hts, CA 91745 USA. NR 15 TC 11 Z9 13 U1 0 U2 10 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JAN-MAR PY 1998 VL 12 IS 1 BP 17 EP 22 DI 10.2514/2.6318 PG 6 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA YU137 UT WOS:000071686000002 ER PT J AU Vijayaraghavan, D Brewe, DE AF Vijayaraghavan, D Brewe, DE TI Effect of rate of viscosity variation on the performance of journal bearings SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Variations in viscosity within the film is known to have a pronounced effect on journal bearing performance. Lubricants of the same grade with the same viscosity at a particular temperature and ambient pressure can have different viscosity values at other-temperature and pressures. The effect of rate of viscosity variation due to the changes in temperature and pressure on the performance of an axial grooved journal bearing is the focus of this investigation. Roelands' model on viscosity-temperature pressure relationship of lubricants is adopted. Cavitation modelling with regard to thermal effects and mass conservation are carefully considered. A total THD model with heat transfer within the fluid film and heat dissipation to the ambient through the journal and bush, is utilized. For different rates of viscosity variation with respect to temperature and pressure, comparison of performance parameters and typical temperature distributions are presented. C1 Univ Toledo, Dept Mech Engn, Toledo, OH 43606 USA. USA, Lewis Res Ctr, NASA, Vehicle Prop Directorate, Cleveland, OH 44135 USA. RP Vijayaraghavan, D (reprint author), USA, Lewis Res Ctr, NASA, Vehicle Prop Directorate, Cleveland, OH 44135 USA. NR 12 TC 16 Z9 17 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4787 J9 J TRIBOL-T ASME JI J. Tribol.-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 1 EP 7 DI 10.1115/1.2834181 PG 7 WC Engineering, Mechanical SC Engineering GA YV241 UT WOS:000071803500001 ER PT J AU Yuan, Q Sun, DC Brewe, DE AF Yuan, Q Sun, DC Brewe, DE TI Study of hybrid lubrication at the tooth contact of a wormgear transmission: Part 1 - Formulation and analysis SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID HYDROSTATIC POCKET; FLOW PATTERNS; ASPECT RATIO; PRESSURE; BEARING AB The paper presents a lubrication analysis for the tooth contact of a proposed wormgear transmission the information needed for the lubrication analysis has been mostly obtained from a previously published wormgear analysis. The information includes the geometry of the clearance between the meshing surfaces, the velocity of the worm surface relative to the gear surface, and the normal force acting on a gear tooth as it moves through the meshing zone. The lubrication analysis is carried out after a design of the oil supply configuration is made, that consists of a single transverse oil recess and a capillary tribe flow, restrictor. Under the predetermined normal force, the lubrication analysis is aimed at obtaining the needed supply pressure to separate the meshing surfaces by a minimum oil film thickness, which is prescribed to insure the establishment of fluid film lubrication at the contact. The lubrication analysis considers (1) the hybrid lubrication effect(combined hydrostatic action and hydrodynamic wedge and squeeze actions), (2) the temperature rise in the oil film flow and the restrictor flow, and (3) the pressure and temperature dependence of oil properties. Part I describes the formulation of the oil film flow problem (in discrete form) and the restrictor flow problem (in analytical form). The two problems are coupled through the conditions of flow continuity and energy balance in the oil recess. C1 SUNY Binghamton, Dept Mech Engn, Binghamton, NY 13902 USA. USA, Res Lab, Vehicle Prop Directorate, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Yuan, Q (reprint author), SUNY Binghamton, Dept Mech Engn, Binghamton, NY 13902 USA. NR 18 TC 1 Z9 1 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4787 J9 J TRIBOL-T ASME JI J. Tribol.-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 103 EP 111 DI 10.1115/1.2834172 PG 9 WC Engineering, Mechanical SC Engineering GA YV241 UT WOS:000071803500019 ER PT J AU Yuan, Q Sun, DC Brewe, DE AF Yuan, Q Sun, DC Brewe, DE TI Study of hybrid lubrication at the tooth contact of a wormgear transmission: Part 2 - Results and discussion SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Part 2 begins by describing the numerical solution procedures of the hybrid lubrication problem. Results of the computation are then presented that include the detailed pressure and temperature distribution in the oil film, the required supply pressure for maintaining the prescribed minimum oil film thickness, the fluid friction acting on the worm coil surface, the mass flow rate of supply oil, and the power loss associated with the restrictor flow. The feasibility of the hydrostatically lubricated wormgear transmission is discussed in light of these results. C1 SUNY Binghamton, Dept Mech Engn, Binghamton, NY 13902 USA. USA, Res Lab, Lewis Res Ctr, Vehicle Prop Directorate, Cleveland, OH 44135 USA. RP Yuan, Q (reprint author), SUNY Binghamton, Dept Mech Engn, Binghamton, NY 13902 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4787 J9 J TRIBOL-T ASME JI J. Tribol.-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 112 EP 118 DI 10.1115/1.2834173 PG 7 WC Engineering, Mechanical SC Engineering GA YV241 UT WOS:000071803500020 ER PT J AU Buffum, DH Capece, VR King, AJ El-Aini, YM AF Buffum, DH Capece, VR King, AJ El-Aini, YM TI Oscillating cascade aerodynamics at large mean incidence SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 41st International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 10-13, 1996 CL BIRMINGHAM, ENGLAND AB The aerodynamics of a cascade of airfoils oscillating in torsion about the midchord is investigated experimentally at a large mean incidence angle and, for reference, at a low mean incidence angle. The airfoil section Is representative of a modern, low-aspect-ratio, aspect-ratio, fan blade tip section. Time-dependent airfoil surface pressure measurements were made for reduced frequencies of up to 1.2 for out-of-phase oscillations at a Mach number of 0.5 and chordal incidence angles of 0 and 10 deg; the Reynolds number was 0.9 x 10(6). For the 10 deg chordal incidence angle, a separation bubble formed at the leading edge of the suction surface. The separated flow field was found to have a dramatic effect on the chordwise distribution of the unsteady pressure. bz this region, substantial deviations from the attached flow data were found, with the deviations becoming less apparent in the aft region of the airfoil for all reduced frequencies. In particular, near the lending edge the separated flow had a strong destabilizing influence while the attached flow had a strong stabilizing influence. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. Pratt & Whitney, W Palm Beach, FL 33410 USA. RP Buffum, DH (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 13 TC 10 Z9 12 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0889-504X J9 J TURBOMACH JI J. Turbomach.-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 122 EP 130 PG 9 WC Engineering, Mechanical SC Engineering GA YV220 UT WOS:000071801400017 ER PT J AU Chima, RV AF Chima, RV TI Calculation of tip clearance effects in a transonic compressor rotor SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 41st International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 10-13, 1996 CL BIRMINGHAM, ENGLAND ID NUMERICAL-ANALYSIS; FLOWS AB The flow through the tip clearance region of a transonic compressor rotor (NASA rotor 37) was computed and compared to aerodynamic probe and laser anemometer data. Tip clearance effects were modeled both by gridding the clearance gap and by using a simple periodicity model across the ungridded gap. The simple model was run with both the full gap height, and with half the gap height to simulate a vena-contracta effect. Comparisons between computed and measured performance maps and downstream profiles were used to validate the models and to assess the effects of gap height on the simple clearance model. Recommendations were made concerning the use of the simple clearance model. Detailed comparisons were made between the gridded clearance gap solution and the laser anemometer data near the tip at two operating points. The computed results agreed fairly well with the data but overpredicted the extent of the casing separation and underpredicted the wake decay rate. The computations were then used to describe the interaction of the tip vortex, the passage shock, and the casing boundary layer. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Chima, RV (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 23 TC 44 Z9 48 U1 2 U2 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0889-504X J9 J TURBOMACH JI J. Turbomach.-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 131 EP 140 PG 10 WC Engineering, Mechanical SC Engineering GA YV220 UT WOS:000071801400018 ER PT J AU Aguirre, AA Spraker, TR Balazs, GH Zimmerman, B AF Aguirre, AA Spraker, TR Balazs, GH Zimmerman, B TI Spirorchidiasis and fibropapillomatosis in green turtles from the Hawaiian Islands SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE Carettacola hawaiiensis; Chelonia mydas; fibropapillomas; green turtle; Hapalotrema dorsopora; Learedius learedi; pathology; spirorchidiasis ID CHELONIA-MYDAS; CUTANEOUS FIBROPAPILLOMAS; SPIRORCHIIDAE; INFECTIONS; AUSTRALIA; DIGENEA AB Pathologic examination of green turtles (Chelonia mydas) from the Hawaiian Islands (USA) was performed to determine the primary cause of mortality. Lesions were associated with fibropapillomatosis (FP) and/or spirorchidiasis (SP) in 16 of 17 green turtles examined. Gross lesions included moderate to severe emaciation, lobulated fibropapillomas of different size classes, serous atrophy of fat, and edema of subcutaneous tissue and muscle. Anasarca, hydropericardium and pulmonary edema were common findings. The neoplastic lesions observed in the gastrointestinal tract, lungs, liver, and kidneys of 29% of turtles examined were histologically characterized as fibromas. A generalized thickening and hardening of major vessels and thrombosis with partial or complete lumen occlusion were observed in turtles with FP and SP. Histologically, lymphoplasmocytic endarteritis was observed in vessels of turtles with both conditions. Multifocal granulomas were associated with trematode ova in the parenchyma of most organs of all turtles with FP and SP. Spirorchidiasis and FP were considered the primary causes of mortality in the turtles examined. Further studies should focus on the pathogenic interaction of both conditions and their synergism as debilitating and fatal diseases in this threatened species. C1 Univ Hawaii, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. Colorado State Univ, Coll Vet Med & Biomed Sci, Colorado Vet Diagnost Lab, Ft Collins, CO 80523 USA. NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Wildlife Pharmaceut Inc, Ft Collins, CO 80524 USA. RP Aguirre, AA (reprint author), Univ Hawaii, Joint Inst Marine & Atmospher Res, 2570 Dole St, Honolulu, HI 96822 USA. NR 27 TC 50 Z9 55 U1 0 U2 7 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 USA SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD JAN PY 1998 VL 34 IS 1 BP 91 EP 98 PG 8 WC Veterinary Sciences SC Veterinary Sciences GA YU630 UT WOS:000071737800011 PM 9476230 ER PT S AU Sahoo, NK Shapiro, AP AF Sahoo, NK Shapiro, AP BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Oxygen enriched binary composite films for high power laser applications SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE optical coatings; thin films; filters; mixed-composite-films; oxygen modulation; inhomogeneity; EDX; AFM AB In recent years, the Emergence ol: novel composite films has created considerable interest in development of complex optical coatings for high power laser applications. In the present work, oxygen pressure dependent tunabitity in optical and structural properties of a mixed-composite thin film material in solid solution has been investigated. It was observed that optical properties of mixed oxide films are greatly influenced by the chemical composition and microstructural changes under various oxygen pressure conditions. Atomic Force Microscopy (AFM) is used to study such structural and morphological changes. Energy dispersive X-ray (EDX) analysis using the features of a scanning electron microscope (SEM) made evident the correlation between the oxygen enrichment and tunability in the film refractive index. Since oxygen pressure can be dynamically varied during a deposition process,coatings constructed of suitable mixed-composite thin films can benefit from continuous modulation of the index of refraction eliminating the discrete interfaces. Electric Field distributions within several multilayer-equivalent optical coatings developed by a step modulation approach have also been analyzed. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Sahoo, NK (reprint author), NASA, George C Marshall Space Flight Ctr, Mail Code EB52, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 446 EP 457 DI 10.1117/12.307027 PG 12 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100057 ER PT S AU Stephen, MA Dallas, JL Afzal, RS AF Stephen, MA Dallas, JL Afzal, RS BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Multi-billion shot, high-fluence exposure of Cr4+: YAG passive Q-switch SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE Cr4+: YAG; passive Q-switch; optical damage; saturable absorber AB NASA's Goddard Space Flight Center is developing the Geoscience Laser Altimeter System (GLAS) employing a diode pumped, Q-switched, Nd:YAG laser operating at 40 Hz repetition rate. To meet the five-year mission lifetime goal, a single transmitter would accumulate over 6.3 billion shots. Cr4+:YAG is a promising candidate material for passively Q-switching the laser. Historically, the performance of saturable absorbers has degraded over long-duration usage.(1) To measure the multi-billion shot performance of Cr4+:YAG, a passively Q-switched GLAS-like oscillator was tested at an accelerated repetition rate of 500 Hz. The intracavity fluence was calculated to be approximately 2.5 J/cm(2). The laser was monitored autonomously for 165 days. There was no evidence of change in the material optical properties during the 7.2 billion shot test.. All observed changes in laser operation could be attributed to pump laser diode aging. This is the first demonstration of multi-billion shot exposure testing of Cr4+:YAG in this pulse energy regime(2). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Stephen, MA (reprint author), NASA, Goddard Space Flight Ctr, Code 554, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 517 EP 521 DI 10.1117/12.307020 PG 5 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100066 ER PT S AU Stephen, MA Krainak, MA Dallas, JL AF Stephen, MA Krainak, MA Dallas, JL BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Quasi-CW laser diode bar life tests SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE laser diode bar; life test AB NASA's Goddard Space Flight Center is developing technology for satellite-based, high peak power, LIDAR transmitters requiring 3-5 years of reliable operation. Semi-conductor laser diodes provide high efficiency pumping of solid state lasers with the promise of long-lived, reliable operation. 100-watt quasi-CW laser diode bars have been baselined for the next generation laser altimeters. Multi-billion shot lifetimes are required. The authors have monitored the performance of several diodes for billions of shots and investigated operational modes for improving diode lifetime. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Stephen, MA (reprint author), NASA, Goddard Space Flight Ctr, Code 554, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 598 EP 604 DI 10.1117/12.307021 PG 7 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100075 ER PT S AU Folkner, WM AF Folkner, WM CA LISA Team BE Folkner, WM TI The LISA mission design SO LASER INTERFEROMETER SPACE ANTENNA SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2nd International LISA Symposium on the Detection and Observation of Gravitational Waves in Space CY JUL, 1998 CL PASADENA, CA SP NASA Off Space Sci, Jet Propuls Lab, CA Inst Technol AB The Laser Interferometer Space Antenna (LISA) will be capable of detecting gravitational waves with frequencies from 0.1 mHz to 1 Hz by using laser interferometers to monitor changes in the distances between test masses in spacecraft separated by five million km. LISA will detect strains as low as 10(-23) With a one year observation time and a signal-to-noise ratio of five. The sensitivity will be sufficient to detect gravitational waves from sources connected with massive black holes in the centers in many galaxies, and from many binary systems within the Milky Way galaxy. Under the concept presented, LISA will be formed by three spacecraft at the vertices of an equilateral triangle. The orbits are chosen so that the triangle formation trails the Earth by 20 degrees. Each spacecraft will contain two independent payloads containing a test mass, laser and 30 cm diameter telescope for the transmission and reception of laser signals. Two independent Michelson interferometers will be formed allowing both polarizations of gravitational waves to be detected. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Folkner, WM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-848-7 J9 AIP CONF PROC PY 1998 VL 456 BP 11 EP 16 PG 6 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BM24Q UT WOS:000078166200002 ER PT S AU Boldt, E Leiter, D AF Boldt, E Leiter, D BE Folkner, WM TI Supermassive black hole quasar remnants SO LASER INTERFEROMETER SPACE ANTENNA SE AIP Conference Proceedings LA English DT Proceedings Paper CT 2nd International LISA Symposium on the Detection and Observation of Gravitational Waves in Space CY JUL, 1998 CL PASADENA, CA SP NASA Off Space Sci, Jet Propuls Lab, CA Inst Technol AB Studies of the cosmic X-ray background indicate that it arises mainly from accretion powered AGNs and that the present-epoch mass density in the form of supermassive black holes must be at least an order of magnitude more than represented by currently active Seyfert galactic nuclei. The black hole mass spectrum of these Seyfert nuclei extends up to similar to 2x10(8) solar masses. Evidence summarized here suggests that much of the local mass density of compact galactic nuclei is associated with inactive quasar remnants which are now black holes that are substantially more massive than Seyfert nuclei. It is emphasized that such quasar remnant black holes are sufficiently massive to preclude the tidal disruption of any infalling stars, solar sized as well as compact. Any Keplerian orbits about these supermassive black holes would have periods exceeding 7 hours. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-848-7 J9 AIP CONF PROC PY 1998 VL 456 BP 50 EP 52 PG 3 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BM24Q UT WOS:000078166200008 ER PT S AU Tinto, M AF Tinto, M BE Folkner, WM TI LISA as a xylophone interferometer detector of gravitational radiation SO LASER INTERFEROMETER SPACE ANTENNA SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2nd International LISA Symposium on the Detection and Observation of Gravitational Waves in Space CY JUL, 1998 CL PASADENA, CA SP NASA Off Space Sci, Jet Propuls Lab, CA Inst Technol AB A filtering technique, for reducing the frequency fluctuations of the laser entering into the two-way Doppler tracking data measured with two spacecraft, is discussed. This method takes advantage of the sinusoidal behavior of the transfer function of this noise source to the Doppler observable, which displays sharp nulls at selected Fourier components. The non-zero gravitational wave signal remaining at these frequencies makes spacecraft to spacecraft laser Doppler tracking the equivalent of a xylophone interferometer detector of gravitational radiation. The data analysis technique presented in this paper could, be implemented with the LISA mission at the Fourier frequencies where the algorithm for unequal-arm interferometers fails to work, or as a backup option in case of failure of one of the three spacecraft. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tinto, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 161-260, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-848-7 J9 AIP CONF PROC PY 1998 VL 456 BP 121 EP 127 PG 7 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BM24Q UT WOS:000078166200018 ER PT S AU Armstrong, JW AF Armstrong, JW BE Folkner, WM TI Spacecraft Doppler gravitational wave experiments SO LASER INTERFEROMETER SPACE ANTENNA SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2nd International LISA Symposium on the Detection and Observation of Gravitational Waves in Space CY JUL, 1998 CL PASADENA, CA SP NASA Off Space Sci, Jet Propuls Lab, CA Inst Technol ID RADIATION; SEARCH; TRACKING AB This paper discusses spacecraft Doppler tracking, the current-generation detection technique in the low-frequency gravitational wave band. Unlike other detectors, the similar to 1-10 AU earth-spacecraft separation makes the Doppler detector large compared with the gravitational wavelength; this has the consequence that a signal is time-resolved into three events in the Doppler time series. The principles of operation, including the transfer functions of the gravitational wave signal and the leading noise processes to the observed Doppler frequency time series, are outlined. Experiments-to-dale, and the expected performance of the very-high-sensitivity Cassini experiment (to be done in 2001-2004) are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Armstrong, JW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-848-7 J9 AIP CONF PROC PY 1998 VL 456 BP 229 EP 235 PG 7 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BM24Q UT WOS:000078166200034 ER PT S AU Tuma, ML Greer, LC Krasowski, MJ Oberle, LG Elam, KA Spina, DC AF Tuma, ML Greer, LC Krasowski, MJ Oberle, LG Elam, KA Spina, DC BE Kujawinska, M Brown, GM Takeda, M TI Real-time two-color laser speckle-shift strain measurement system SO LASER INTERFEROMETRY IX: TECHNIQUES AND ANALYSIS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Interferometry IX - Techniques and Analysis CY JUL 20-21, 1998 CL SAN DIEGO, CA SP SPIE - Soc Photo-Opt Inst Engn DE speckle strain; strain measurement; speckle pattern; hardware correlator; fiber AB A real-time two-color laser speckle-shift strain measurement system based on Yamaguchi's technique was designed, built, and tested at room temperature. This non-contact 1-D system detects surface strain in a structural fiber as it is pulled in a tensile test machine (Instron 4502). Interference or speckle patterns from the laser illuminated fiber test specimen are recorded. As the fiber is pulled, its speckle patterns shift in proportion to the strain, translation, arid rotation components of the sample deformation. Shifting speckle patterns are detected at real-time rates using 2 linear CCD arrays with image processing performed by a hardware correlator. Surface strain detected in fibers with diameters on the order of 100 mu m can be resolved to 19 microstrain (mu epsilon). This system was designed to be compact and robust and generally does not require surface preparation of the structural fibers. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Tuma, ML (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2933-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3478 BP 314 EP 321 DI 10.1117/12.312951 PG 8 WC Mechanics; Optics SC Mechanics; Optics GA BM33C UT WOS:000078398900032 ER PT J AU Barnes, NP AF Barnes, NP TI Remote sensing of planet earth challenges for solid-state lasers SO LASER PHYSICS LA English DT Article AB Global remote sensing of Planet Earth over protracted time intervals is necessary if the global community wishes to adopt reasoned responses to anthropogenically induced changes in the environment. Laser remote sensors using solid-state lasers can measure many of the Earth variables, such as the ozone levels, needed to describe the health of Planet Earth from orbit. However, the lasers are usually highly specialized devices, often requiring unusual wavelengths, tuning capability, dual pulse capability, as well as high efficiency and reliability. Laser remote sensing techniques are covered along with an example of the development being performed at NASA Langley on a specific laser system for remote sensing. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Barnes, NP (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 1 TC 3 Z9 3 U1 1 U2 1 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA SN 1054-660X J9 LASER PHYS JI Laser Phys. PD JAN-FEB PY 1998 VL 8 IS 1 BP 25 EP 28 PG 4 WC Optics; Physics, Applied SC Optics; Physics GA ZB459 UT WOS:000072474100005 ER PT S AU Kavaya, MJ Emmitt, GD AF Kavaya, MJ Emmitt, GD BE Kamerman, GW TI The space readiness coherent lidar experiment (SPARCLE) space shuttle mission SO LASER RADAR TECHNOLOGY AND APPLICATIONS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Laser Radar Technology and Applications III CY APR 14-16, 1998 CL ORLANDO, FL SP SPIE DE wind velocity; Doppler lidar; coherent detection AB For over 20 years researchers have been investigating the feasibility of profiling tropospheric vector wind velocity from space with a pulsed Doppler lidar. Efforts have included theoretical development, system and mission studies, technology development, and ground-based and airborne measurements. Now NASA plans to take the next logical step towards enabling operational global tropospheric wind profiles by demonstrating horizontal wind measurements from the Space Shuttle in early 2001 using a coherent Doppler wind lidar system. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Kavaya, MJ (reprint author), NASA, George C Marshall Space Flight Ctr, Mail Code HR20, Huntsville, AL 35812 USA. NR 0 TC 16 Z9 16 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2829-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3380 BP 2 EP 11 DI 10.1117/12.327186 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL68V UT WOS:000076320100001 ER PT S AU Singh, UN AF Singh, UN BE Kamerman, GW TI Development of high-pulse energy Ho : Tm : YLF coherent transmitters SO LASER RADAR TECHNOLOGY AND APPLICATIONS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Laser Radar Technology and Applications III CY APR 14-16, 1998 CL ORLANDO, FL SP SPIE DE lidar; solid state laser; Doppler lidar; coherent detection AB NASA Langley has developed a diode-pumped, room temperature Ho:Tm:YLF coherent pulsed transmitter for SPARCLE, a NASA approved space shuttle mission. The acronym stands for SPAce Readiness Coherent Lidar Experiment and is expected to fly in 2001. SPARCLE mission objective is to carry out first ever global wind measurement from space. The laser transmitter for SPARCLE is a Ho:Tm:YLF power oscillator operating at eye-safe wavelength of 2.05 mu m. The Q-switched output energy is 125 mi at six Hz, and it has a near-transform limited beam with a pulse width of 170 ns. The high power and high beam quality of this laser makes it well suited as a coherent wind lidar transmitter on a space platform. When the output of this power oscillator is amplified by using four diode-pumped Ho:Tm:YLF amplifiers, an output energy of 600 mi at 10 Hz has been achieved. This is the highest energy ever produced at 10 Hz, and is at least an order of magnitude greater than previously achieved for 2- mu m diode-pumped laser at room temperature. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Singh, UN (reprint author), NASA, Langley Res Ctr, MS 474, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2829-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3380 BP 70 EP 74 DI 10.1117/12.327181 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL68V UT WOS:000076320100009 ER PT S AU Hemmati, H Esproles, C Menzies, RT AF Hemmati, H Esproles, C Menzies, RT BE Kamerman, GW TI Frequency-stabilized diode-pumped Tm,Ho : YLF local oscillator with +/- 4 GHz of tuning range SO LASER RADAR TECHNOLOGY AND APPLICATIONS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Laser Radar Technology and Applications III CY APR 14-16, 1998 CL ORLANDO, FL SP SPIE DE Tm,Ho : YLF; 2-micron laser; coherent lidar; frequency-stabilization; frequency-agility AB A tunable, single-frequency, frequency-stabilized diode-pumped Tm,Ho: YLF laser is described. The laser, which demonstrates the function of a local-oscillator for coherent Doppler lidar in space, has continuous frequency tunability of more than 8 GHz. Active frequency stabilization is achieved by feedback electronics which allow for controlled tuning capability. Output power of more than 20 mW in single-transverse and -longitudinal mode operation with a short term frequency jitter of less than 100 kHz/ms is obtained. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hemmati, H (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 SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2829-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3380 BP 75 EP 79 DI 10.1117/12.327182 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL68V UT WOS:000076320100010 ER PT S AU Howard, RT Bryan, TC Book, ML AF Howard, RT Bryan, TC Book, ML BE Kamerman, GW TI Video Guidance Sensor flight experiment results SO LASER RADAR TECHNOLOGY AND APPLICATIONS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Laser Radar Technology and Applications III CY APR 14-16, 1998 CL ORLANDO, FL SP SPIE DE video; guidance; sensor; flight-experiment; automated rendezvous AB An active video sensor system for determining target range and attitude was flown on STS-87. The Video Guidance Sensor (VGS), developed at NASA's Marshall Space Flight Center (MSFC), demonstrated its capability in space and collected performance data. The VGS was designed to provide near-range sensor data as part of an automatic rendezvous and docking system. The sensor determines the relative positions and attitudes between the active sensor and the passive target. The VGS uses laser diodes to illuminate retro-reflectors in the target, a solid-state camera to detect the return from the target, and a frame grabber and digital signal processor to convert the video information into the relative positions and attitudes. The system is designed to operate with the target within a relative azimuth of +/- 9.5 degrees and a relative elevation of +/- 7.5 degrees. The system will acquire and track the target within the defined field-of-view between 1.5 meters and 110 meters range, and the VGS is designed to acquire at relative attitudes of +/- 10 degrees in pitch and yaw and at any roll angle. The sensor outputs the data at 5 Hz, and the target and sensor software and hardware have been designed to permit two independent sensors to operate simultaneously. This allows for redundant sensors. The data from the flight experiment includes raw video data from the VGS camera, relative position and attitude measurements from the VGS, solar angle data, and Remote Manipulator System (RMS) position data to correlate with the VGS data. The experiment was quite successful acid returned significant verification of the sensor's capabilities. The experience gained from the design and flight of this experiment will lead to improved video sensors in the future. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Howard, RT (reprint author), NASA, George C Marshall Space Flight Ctr, MS EB44F, Huntsville, AL 35812 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2829-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3380 BP 315 EP 326 DI 10.1117/12.327204 PG 12 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL68V UT WOS:000076320100033 ER PT S AU Mancinelli, RL White, MR Rothschild, LJ AF Mancinelli, RL White, MR Rothschild, LJ BE Horneck, G Brack, A Devincenzi, DL Fogg, MJ Banin, A Klein, HP Masson, P TI Biopan-survival I: Exposure of the osmophiles Synechococcus sp. (Nageli) and Haloarcula sp. to the space environment SO LIFE SCIENCES: EXOBIOLOGY SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F3 1, F3 3, F3 4 and F3 5 Symposia of COSPAR Scientific Commission F on Life Sciences - Exobiology at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, NASA, Russian Acad Sci, British Interplanetary Soc ID MICROORGANISMS; RADIATION; SPORES; DNA; UV AB The objective of this study was to determine the survivability of osmophilic microorganisms in space, as well as examine the DNA breakage in osmophilic cells exposed to solar UV-radiation plus vacuum and to vacuum only. The organisms used were an unidentified species of Synechococcus (Nageli) that inhabits the evaporitic gypsum-halite crusts that form along the marine intertidal, and an unidentified species of the extremely halophilic genus Haloarcula (designated as isolate G) isolated from a evaporitic NaCl crystal. Because these organisms are desiccation resistant and gypsum-halite as well as NaCl attenuate UV-radiation, we hypothesized that these organisms would survive in the space environment, better than most others. The organisms were exposed to the space environment for 2 weeks while in earth orbit aboard the Biopan facility. Ground controls were tested in a space simulation facility. All samples were compared to unexposed samples. Survivability was determined by plate counts and the most probable number technique. DNA breakage was determined by labeling breaks in the DNA with P-32 followed by translation. Results indicate that the osmophilic microbes survived the 2 week exposure. The major cause of cell death was DNA damage. The number of strand breaks in the DNA from vacuum UV exposed cells was greater than the vacuum only exposed cells. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Mancinelli, RL (reprint author), NASA, Ames Res Ctr, MS 239-12, Moffett Field, CA 94035 USA. RI Mancinelli, Rocco/L-8971-2016 NR 36 TC 60 Z9 65 U1 1 U2 4 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043467-3 J9 ADV SPACE RES PY 1998 VL 22 IS 3 BP 327 EP 334 DI 10.1016/S0273-1177(98)00189-6 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology; Meteorology & Atmospheric Sciences GA BL44X UT WOS:000075554600002 ER PT S AU Breus, TK Pimenov, KY Luhmann, JG Krymsky, A Hagfors, T Axford, WI Kliore, A AF Breus, TK Pimenov, KY Luhmann, JG Krymsky, A Hagfors, T Axford, WI Kliore, A BE Horneck, G Brack, A Devincenzi, DL Fogg, MJ Banin, A Klein, HP Masson, P TI Application of Viking radio occultation data to the future studies of the Martian ionosphere SO LIFE SCIENCES: EXOBIOLOGY SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F3 1, F3 3, F3 4 and F3 5 Symposia of COSPAR Scientific Commission F on Life Sciences - Exobiology at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, NASA, Russian Acad Sci, British Interplanetary Soc ID SOLAR-WIND INTERACTION; VENUS IONOSPHERE; MAGNETIC-FIELDS; PRESSURE AB Topside electron density profiles provide information on the solar wind interactions with the terrestrial planets, Venus and Mars. At Mars we have a picture of the topside only from two Viking Lander profiles and from radio occultation measurements. These produced somewhat ambiguous results, and so the existence of a Martian "ionopause" and of the Martian magnetic field is much-debated. Topside ionospheric sounding is a potentially powerful technique for remotely sensing global upper ionosphere structure. The Mars-96 Long Wave Radar will finally provide the opportunity to use this capability. Using examples of electron density profiles obtained by radio occultation of Vikings we illsutrate the potential of the radar technique for determining such profiles, and by implication for identifying such features as ionopauses and the magnetic field in the Martian ionosphere. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 Moscow Space Res Inst, Moscow 117810, Russia. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Rostov State Univ, Rostov On Don 344006, Russia. Max Planck Inst Aeron, Lindau, Germany. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Breus, TK (reprint author), Moscow Space Res Inst, Moscow 117810, Russia. NR 19 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043467-3 J9 ADV SPACE RES PY 1998 VL 22 IS 3 BP 463 EP 470 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology; Meteorology & Atmospheric Sciences GA BL44X UT WOS:000075554600018 ER PT S AU Mancinelli, RL AF Mancinelli, RL BE Horneck, G Brack, A Devincenzi, DL Fogg, MJ Banin, A Klein, HP Masson, P TI Prospects for the evolution of life on Mars Viking 20 years later SO LIFE SCIENCES: EXOBIOLOGY SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F3 1, F3 3, F3 4 and F3 5 Symposia of COSPAR Scientific Commission F on Life Sciences - Exobiology at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, NASA, Russian Acad Sci, British Interplanetary Soc ID MARTIAN METEORITE ALH84001; PLANETARY-ATMOSPHERES; ORIGIN; EARTH; WATER; ICE; EVAPORITES; SEARCH; SYSTEM; WARM AB During the summer of 1976 the two Viking spacecraft arrived at Mars. Their primary objective was to determine if them was life on Mars. The results of the three life detection experiments aboard the two landers, while not definitive, did not show the presence of extant life. In addition, the GC-MS analyses did not find any organic matter in the Martian regolith at either landing site. Although Viking found no life, it provided data to help explain why no extant life was found at the Martian surface: The surface of Mars is an oxidizing, desiccated environment devoid of liquid water. However, data from the chemical analyses of the regolith conducted during the Viking mission as well as recent analyses of SNC meteorites suggests that all of the chemical elements necessary for life to arise occur on Mars. Further, Mars and Earth accreted from the same interplanetary material suggesting that the early chemical and physical environments of the two planets may have been similar. If this is true then the prospects for the evolution of life on Mars rests on the degree and the duration of similarity between Earth and Mars. Data gathered to date suggests that if liquid water existed on the surface of Mars far sufficient time the probability for life to have arisen is quite reasonable. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Mancinelli, RL (reprint author), NASA, Ames Res Ctr, MS 239-12, Moffett Field, CA 94035 USA. RI Mancinelli, Rocco/L-8971-2016 NR 53 TC 5 Z9 5 U1 4 U2 7 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043467-3 J9 ADV SPACE RES PY 1998 VL 22 IS 3 BP 471 EP 477 DI 10.1016/S0273-1177(98)00088-X PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology; Meteorology & Atmospheric Sciences GA BL44X UT WOS:000075554600019 ER PT S AU Cook, ME Croxdale, JL Tibbitts, TW Goins, G Brown, CS Wheeler, RM AF Cook, ME Croxdale, JL Tibbitts, TW Goins, G Brown, CS Wheeler, RM BE MontufarSolis, D Barlow, PW Moore, D Hader, DP Ishay, JS TI Development and growth of potato tubers in microgravity SO LIFE SCIENCES: MICROGRAVITY RESEARCH SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT Symposia of the COSPAR Scientific-Commission-F on Life Sciences - Microgravity Research at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, Ctr Natl Etud Spatiales, France, Amer Inst Aeronaut & Astronaut, Inst Med Aerospatiale Servie Sante Armees, Ctr Etud & Rech Med Aerospatiale, Deut Agentur Raumfahrt Angelegenheiten GMBH, Germany ID ZEA-MAYS; SPACEFLIGHT; GRAVITY; CELLS AB A potato explant consisting of a leaf, its axillary bud, and a small segment of stem will develop a tuber in 10-14 days when grown on earth. The tubers develop from the axillary buds and accumulate starch derived from sugars produced through photosynthesis and/or mobilized from leaf tissue. Potato explants were harvested and maintained in the Astroculture(TM) unit, a plant growth chamber designed for spaceflight. The unit provides an environment with controlled temperature, humidity, CO( 2)level, light intensity, and a nutrient delivery system. The hardware was loaded onto the space shuttle Columbia 24 hours prior to the launch of the STS-73 mission. Fxplant leaf tissue appeared turgid and green for the first 11 days of flight, but then became;chlorotic and eventually necrotic by the end of the mission. The same events occurred to ground control explants with approximately the same timing. At the end of the 16-day mission, tubers were present on each explant. The size and shape of the space-grown tubers were similar to the ground-control tubers. The arrangement of cells in the tuber interior and at the exterior in the periderm was similar in both environments. Starch and protein were present in the tubers grown in space and on the ground. The range in starch grain size was similar in tubers from both environments, but the distribution of grains into size classes differed somewhat, with the space-grown tubers having more small grains than the ground control tubers. Proteinaceous crystals were found in tubers formed in each condition. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 Univ Wisconsin, Dept Bot, Madison, WI 53706 USA. Univ Wisconsin, Dept Hort, Madison, WI 53706 USA. Dynamac Corp, Kennedy Space Ctr, FL 32899 USA. NASA, Biomed Off, Kennedy Space Ctr, FL 32899 USA. RP Cook, ME (reprint author), Univ Wisconsin, Dept Bot, Madison, WI 53706 USA. NR 29 TC 6 Z9 6 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043461-4 J9 ADV SPACE RES PY 1998 VL 21 IS 8-9 SI 1998 BP 1103 EP 1110 DI 10.1016/S0273-1177(97)00197-X PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Physiology SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences; Physiology GA BL11P UT WOS:000074330200008 PM 11541357 ER PT S AU Reddy, ASN Kao, YL Mykles, DL Sadeh, WZ Wheeler, RM AF Reddy, ASN Kao, YL Mykles, DL Sadeh, WZ Wheeler, RM BE MontufarSolis, D Barlow, PW Moore, D Hader, DP Ishay, JS TI A ground-based study for a shuttle BRIC experiment on gravity effects on gene expression SO LIFE SCIENCES: MICROGRAVITY RESEARCH SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT Symposia of the COSPAR Scientific-Commission-F on Life Sciences - Microgravity Research at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, Ctr Natl Etud Spatiales, France, Amer Inst Aeronaut & Astronaut, Inst Med Aerospatiale Servie Sante Armees, Ctr Etud & Rech Med Aerospatiale, Deut Agentur Raumfahrt Angelegenheiten GMBH, Germany ID CALMODULIN-BINDING PROTEIN; ARABIDOPSIS; GRAVITROPISM; TRANSDUCTION; CALCIUM; PLANTS; RNAS AB A BRIC (Biological Research In a Canister) experiment to investigate the effects of reduced gravity at the molecular level using Arabidopsis has been initiated. In preparation for a space flight experiment, a series of ground-based studies were conducted. Results from these studies indicate that: 1) up to 20,000 seeds can be germinated on a 100 mm diameter Petri plate, 2) nylon membrane is the best surface for recovery of plant material after freezing, 3) depending on the age of the seedlings at the time of freezing, 20 to 40 g of tissue can be obtained from Petri plates that fit in a single canister; 4) tissue from one canister yields adequate amounts of RNA to perform differential display to isolate gravity-regulated genes. Our results indicate that the proposed BRIC experiment is feasible and can provide valuable information on the possible effects of microgravity on gene regulation. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 Colorado State Univ, Dept Biol, Ctr Engn Infrastruct & Sci Space, Ft Collins, CO 80523 USA. Colorado State Univ, Dept Civil Engn, Ctr Engn Infrastruct & Sci Space, Ft Collins, CO 80523 USA. NASA, Biol Res & Life Support Off, Kennedy Space Ctr, FL 32899 USA. RP Reddy, ASN (reprint author), Colorado State Univ, Dept Biol, Ctr Engn Infrastruct & Sci Space, Ft Collins, CO 80523 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043461-4 J9 ADV SPACE RES-SERIES PY 1998 VL 21 IS 8-9 SI 1998 BP 1219 EP 1224 DI 10.1016/S0273-1177(97)00638-8 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Physiology SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences; Physiology GA BL11P UT WOS:000074330200029 PM 11541375 ER PT S AU Watson, CJ Dyer, CS Truscott, PR Peerless, CL Sims, AJ Barth, JL AF Watson, CJ Dyer, CS Truscott, PR Peerless, CL Sims, AJ Barth, JL BE Heynderickx, D Smart, DF TI The low earth orbit environment observed using CREAM and CREDO SO LIFE SCIENCES: RADIATION ENVIRONMENT AND MODELLING SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 1 and F2 2 Symposia of COSPAR Scientific Commission F on Life Sciences - Radiation Environment and Modelling, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Russian Space Agcy, European Space Agcy, Jet Propuls Lab ID RADIATION ENVIRONMENT; APEX AB The Cosmic Radiation Environment and Dosimetry experiment (CREDO) has been operational on board the Advanced Photovoltaics & Electronics Experiment Spacecraft since August 1994. Extensive measurements of cosmic ray linear energy transfer spectra (using data to January 1996) and total dose (using data to November 1994) have been made, and compared with predictions of standard models. Detailed consideration of spacecraft shielding effects have been made. Predictions are shown to overestimate the measured linear energy transfer spectra. The CREAM experiment was flown on STS-63 in the SpaceHab module. Results show penetration of high energy electrons into the SpaceHab module. (C)1998 COSPAR. Published by Elsevier Science Ltd. C1 Def Res Agcy, Dept Space, Farnborough GU14 6TD, Hants, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Watson, CJ (reprint author), Def Res Agcy, Dept Space, Farnborough GU14 6TD, Hants, England. RI Sims, Andrew/B-7001-2012 OI Sims, Andrew/0000-0002-9553-7278 NR 8 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043464-9 J9 ADV SPACE RES PY 1998 VL 21 IS 12 BP 1621 EP 1624 DI 10.1016/S0273-1177(98)00004-0 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL31Y UT WOS:000075095700001 PM 11542876 ER PT S AU Fung, SF Tan, LC Bilitza, D Boscher, D Cooper, JF AF Fung, SF Tan, LC Bilitza, D Boscher, D Cooper, JF BE Heynderickx, D Smart, DF TI An investigation of the spatial variations of the energetic trapped electrons at low altitudes SO LIFE SCIENCES: RADIATION ENVIRONMENT AND MODELLING SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 1 and F2 2 Symposia of COSPAR Scientific Commission F on Life Sciences - Radiation Environment and Modelling, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Russian Space Agcy, European Space Agcy, Jet Propuls Lab ID RADIATION BELT AB We have analyzed the trapped electron data (0.19-3.2 MeV) taken by the Japanese OHZORA satellite operated at 350-850 km altitude in polar orbit during 1984-1987 near solar minimum. The electron observations reveal all the global attributes of the quiet-time electron radiation belts, such as the South Atlantic Anomaly, the electron "slot", and the outer radiation belt regions. The electron data are in general agreement with the NASA AE-8 electron model, but there are differences, particularly with respect to distinctive local-time variations in the slot region. In this paper, we present results from analyses of variations of the electron pitch angle distributions with local time, L-shell and altitude. (C)1998 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Space Phys Data Facil, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Hughes STX Corp, Greenbelt, MD 20770 USA. RP Fung, SF (reprint author), NASA, Space Phys Data Facil, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Cooper, John/D-4709-2012; Fung, Shing/F-5647-2012 NR 7 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043464-9 J9 ADV SPACE RES PY 1998 VL 21 IS 12 BP 1661 EP 1664 DI 10.1016/S0273-1177(98)00010-6 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL31Y UT WOS:000075095700007 PM 11542882 ER PT S AU Croley, DR Spitale, GC AF Croley, DR Spitale, GC BE Heynderickx, D Smart, DF TI Solar heavy ion Heinrich fluence spectrum at low earth orbit SO LIFE SCIENCES: RADIATION ENVIRONMENT AND MODELLING SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 1 and F2 2 Symposia of COSPAR Scientific Commission F on Life Sciences - Radiation Environment and Modelling, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Russian Space Agcy, European Space Agcy, Jet Propuls Lab ID ABUNDANCES; EVENTS AB Solar heavy ions from the JPL Solar Heavy Ion Model have been transported into low earth orbit using the Schulz cutoff criterion for L-shell access by ions of a specific charge to mass ratio. The NASA Brouwer orbit generator was used to get L values along the orbit at 60 second time intervals. Heavy ion fluences of ions 2 less than or equal to Z less than or equal to 92 have been determined for the LET range 1 to 130 MeV-cm(2)/mg by 60, 120 or 250 mils of aluminum over a period of 24 hours in a 425 km circular orbit inclined 51 degrees, The ion fluence is time dependent in the sense that the position of the spacecraft in the orbit at the flare onset time fixes the relationship between particle flux and spacecraft passage through high L-values where particles have access to the spacecraft, (C)1998 COSPAR. Published by Elsevier Science Ltd. C1 SYSCON Corp, Montrose, CA 91020 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Croley, DR (reprint author), SYSCON Corp, 2550 Honolulu Ave 201, Montrose, CA 91020 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043464-9 J9 ADV SPACE RES PY 1998 VL 21 IS 12 BP 1683 EP 1687 DI 10.1016/S0273-1177(98)00016-7 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL31Y UT WOS:000075095700012 PM 11542887 ER PT S AU Cucinotta, FA Wilson, JW Shinn, JL Tripathi, RK AF Cucinotta, FA Wilson, JW Shinn, JL Tripathi, RK BE Heynderickx, D Smart, DF TI Assessment and requirements of nuclear reaction databases for GCR transport in the atmosphere and structures SO LIFE SCIENCES: RADIATION ENVIRONMENT AND MODELLING SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 1 and F2 2 Symposia of COSPAR Scientific Commission F on Life Sciences - Radiation Environment and Modelling, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Russian Space Agcy, European Space Agcy, Jet Propuls Lab ID FRAGMENTATION MODEL; SPALLATION; IONS AB The transport properties of galactic cosmic rays (GCR) in the atmosphere, material structures, and human body (self-shielding) are of interest in risk assessment for supersonic and subsonic aircraft and for space travel in low-Earth orbit and on interplanetary missions. Nuclear reactions, such as knockout and fragmentation, present large modifications of particle type and energies of the galactic cosmic rays in penetrating materials. We make an assessment of the current nuclear reaction models and improvements in these model for developing required transport code data bases. A new fragmentation data base (QMSFRG) based on microscopic models is compared to the NUCFRG2 model and implications for shield assessment made using the HZETRN radiation transport code. For deep penetration problems, the build-up of light particles, such as nucleons, light clusters and mesons from nuclear reactions in conjunction with the absorption of the heavy ions, leads to the dominance of the charge Z = 0, 1, and 2 hadrons in the exposures at large penetration depths. Light particles are produced through nuclear or cluster knockout and in evaporation events with characteristically distinct spectra which play unique roles in the build-up of secondary radiation's in shielding. We describe models of light particle production in nucleon and heavy ion induced reactions and make an assessment of the importance of light particle multiplicity and spectral parameters in these exposures. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Hampton, VA 23662 USA. RP Cucinotta, FA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 22 TC 14 Z9 14 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043464-9 J9 ADV SPACE RES PY 1998 VL 21 IS 12 BP 1753 EP 1762 DI 10.1016/S0273-1177(98)00062-3 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL31Y UT WOS:000075095700020 PM 11542895 ER PT S AU Wilson, JW Cucinotta, FA Tai, H Shinn, JL Chun, SY Tripathi, RK Sihver, L AF Wilson, JW Cucinotta, FA Tai, H Shinn, JL Chun, SY Tripathi, RK Sihver, L BE Heynderickx, D Smart, DF TI Transport of light ions in matter SO LIFE SCIENCES: RADIATION ENVIRONMENT AND MODELLING SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 1 and F2 2 Symposia of COSPAR Scientific Commission F on Life Sciences - Radiation Environment and Modelling, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Russian Space Agcy, European Space Agcy, Jet Propuls Lab ID 670A MEV NE-20; HZE PROPAGATION; FRAGMENTATION; DEPTH; WATER AB A recent set of light ion experiments are analyzed using the Green's function method of solving the Boltzmann equation for ions of high charge and energy (the GRNTRN transport code) and the NUCFRG2 fragmentation database generator code. Although the NUCFRG2 code reasonably represents the fragmentation of heavy ions, the effects of light ion fragmentation requires a more detailed nuclear model including shell structure and short range correlations appearing as tightly bound clusters in the light ion nucleus. The most recent NUCFRG2 code is augmented with a quasielastic alpha knockout model and semiempirical adjustments (up to 30 percent in charge removal) in the fragmentation process allowing reasonable agreement with the experiments to be obtained. A final resolution of the appropriate cross sections must await the full development of a coupled channel reaction model in which shell structure and clustering can be accurately evaluated. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Old Dominion Univ, Norfolk, VA 23581 USA. Hampton Univ, Hampton, VA 23668 USA. GSI Darmstadt, D-6100 Darmstadt, Germany. RP Wilson, JW (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 18 TC 8 Z9 8 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043464-9 J9 ADV SPACE RES PY 1998 VL 21 IS 12 BP 1763 EP 1771 DI 10.1016/S0273-1177(98)00063-5 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL31Y UT WOS:000075095700021 PM 11542896 ER PT S AU Townsend, LW Tripathi, RK Cucinotta, FA Bagga, R AF Townsend, LW Tripathi, RK Cucinotta, FA Bagga, R BE Heynderickx, D Smart, DF TI Liquid drop model considerations in HZE particle fragmentation by hydrogen SO LIFE SCIENCES: RADIATION ENVIRONMENT AND MODELLING SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 1 and F2 2 Symposia of COSPAR Scientific Commission F on Life Sciences - Radiation Environment and Modelling, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Russian Space Agcy, European Space Agcy, Jet Propuls Lab ID HEAVY-ION FRAGMENTATION; CROSS-SECTIONS; TARGETS AB The fragmenting of high energy, heavy ions by hydrogen targets is an important physical process in several areas of space radiation protection research. Quantum mechanical, optical model methods for calculating cross sections for particle fragmentation by hydrogen have been developed from a modified abrasion-ablation collision formalism. The abrasion stage is treated as a knockout process which leaves the residual prefragment in an excited state, In the ablation stage the prefragment deexcites to produce the final fragment. The prefragment excitation energies are estimated from a combination of liquid drop model considerations and frictional-spectator interaction processes. Estimates of elemental and isotopic production cross sections are in good agreement with published cross section measurements. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA. So Illinois Univ, Dept Phys, Carbondale, IL 62901 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. RP Townsend, LW (reprint author), Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043464-9 J9 ADV SPACE RES PY 1998 VL 21 IS 12 BP 1773 EP 1776 DI 10.1016/S0273-1177(98)00064-7 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL31Y UT WOS:000075095700022 PM 11542897 ER PT S AU Badhwar, GD Dudkin, V Doke, T Atwell, W AF Badhwar, GD Dudkin, V Doke, T Atwell, W BE Reitz, G Kronenberg, A TI Radiation measurements on the flight of IML-2 SO LIFE SCIENCES: RECENT DOSIMETRY RESULTS, CHROMOSOME DAMAGE AND HERITABLE EFFECTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 6 and F2 9 Symposia of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Int Council Sci Unions, Comm Space Res ID SPECTRA AB The second flight of the International Microgravity Laboratory (IML-2) on Space Shuttle night STS-65 provided a unique opportunity for the intercomparison of a wide variety of radiation measurement techniques. Although this was not a coordinated or planned campaign, by shear chance, a number of space radiation experiments from several countries were flown on this mission. There were active radiation measuring instruments from Japan and US, and passive detectors from US, Russia, Japan, and Germany. These detectors were distributed throughout the Space Shuttle volume: payload bay, middeck, flight deck, and Spacelab. STS-65 was launched on July 8, 1994, in a 28.45 degrees x 306 km orbit for a duration of 14 d 17 hr and 55 min, The crew doses varied from 0.935 mGy to 1.235 mGy. A factor of two variation was observed between various passive detectors mounted inside the habitable Shuttle volume. There is reasonable agreement between the galactic cosmic ray dose, dose equivalent and LET spectra measured by the tissue equivalent proportional counter flown in the payload bay with model calculations. There are significant differences in the measurements of LET spectra measured by different groups. The neutron spectrum in the 1-20 MeV region was measured. Using fluence-dose conversion factors, the neutron dose and dose equivalent rates were 11+/-2.7 mu Gy/day and 95+/-23.5 mu Sv/day respectively. The average east-west asymmetry of trapped proton (>30MeV) and (>60 MeV) dose rate was 3.3 and 1.9 respectively. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Res Ctr Spacecraft Safety, Moscow 100058, Russia. Waseda Univ, Shinjuku Ku, Tokyo 169, Japan. Rockwell Int Corp, Houston, TX 77058 USA. RP Badhwar, GD (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 15 TC 1 Z9 1 U1 1 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043468-1 J9 ADV SPACE RES PY 1998 VL 22 IS 4 BP 485 EP 494 DI 10.1016/S0273-1177(98)01068-0 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Genetics & Heredity; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Genetics & Heredity; Geology; Meteorology & Atmospheric Sciences GA BL54Y UT WOS:000075849900001 PM 11542776 ER PT S AU Badhwar, GD Atwell, W Cash, B Petrov, VM Akatov, YA Tchernykh, IV Shurshakov, VA Arkhangelsky, VA AF Badhwar, GD Atwell, W Cash, B Petrov, VM Akatov, YA Tchernykh, IV Shurshakov, VA Arkhangelsky, VA BE Reitz, G Kronenberg, A TI Radiation environment on the mir orbital station during solar minimum SO LIFE SCIENCES: RECENT DOSIMETRY RESULTS, CHROMOSOME DAMAGE AND HERITABLE EFFECTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 6 and F2 9 Symposia of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Int Council Sci Unions, Comm Space Res AB The Mir station has been in a 51.65 degrees inclination orbit since March 1986. In March 1995, the first US astronaut flew on the Mir-18 mission and returned on the Space Shuttle in July 1995. Since then three additional US astronauts have stayed on orbit for up to 6 months. Since the return of the first US astronaut, both the Spektr and Priroda modules have docked with Mir station, altering the mass shielding distribution. Radiation measurements, including the direct comparison of US and Russian absorbed dose rates in the Base Block of the Mir station, were made during the Mir-18 and -19 missions. There is a significant variation of dose rates across the core module; the six locations sampled showed a variation of a factor of nearly two. A tissue equivalent proportional counter (TEPC) measured a total absorbed dose rate of 300 mu Gy/day, roughly equally divided between the rate due to trapped protons from the South Atlantic Anomaly (SAA) and galactic cosmic radiation (GCR). This dose rate is about a factor of two lower than the rate measured by the thinly shielded (0.5 g cm(-2) of Al) operational ion chamber (R-16), and about 3/2 of the rate of the more heavily shielded (3.5 g cm(-2) of Al) ion chamber. This is due to the differences in the mass shielding properties at the location of these defectors. A comparison of integral linear energy transfer (LET) spectra measured by TEPC and plastic nuclear track detectors (PNTDs) deployed side by side are in remarkable agreement in the LET region of 15 - 1000 keV/mu m, where the PNTDs are fully efficient. The average quality factor, using the ICRP-26 definition, was 2.6, which is higher than normally used. There is-excellent agreement between the measured GCR dose rate and model calculations, but this is not true for trapped protons. The measured Mir-18 crew skin dose equivalent rate was 1133 mu Sv/day. Using the skin dose rate and anatomical models, we have estimated the blood-forming organ (BFO) dose rate and the maximum stay time in orbit for International Space Station crew members. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Inst Biomed Problems, Moscow 1000027, Russia. Lockheed Martin, Houston, TX 77058 USA. Rockwell Aerosp, Houston, TX 77058 USA. RP Badhwar, GD (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 9 TC 20 Z9 20 U1 0 U2 3 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043468-1 J9 ADV SPACE RES PY 1998 VL 22 IS 4 BP 501 EP 510 DI 10.1016/S0273-1177(98)01070-9 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Genetics & Heredity; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Genetics & Heredity; Geology; Meteorology & Atmospheric Sciences GA BL54Y UT WOS:000075849900003 PM 11542778 ER PT S AU Cucinotta, FA Wilson, JW Tripathi, RK Townsend, LW AF Cucinotta, FA Wilson, JW Tripathi, RK Townsend, LW BE Reitz, G Kronenberg, A TI Microscopic fragmentation model for galactic cosmic ray studies SO LIFE SCIENCES: RECENT DOSIMETRY RESULTS, CHROMOSOME DAMAGE AND HERITABLE EFFECTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 6 and F2 9 Symposia of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Int Council Sci Unions, Comm Space Res ID CROSS-SECTIONS AB We describe theoretical considerations for developing models of heavy ion fragmentation appropriate far galactic cosmic ray studies. Previous models have been based on parametric fits to limited experimental data or models that ignored some aspects of the reaction dynamics, including nuclear cluster effects. The abrasion-ablation description of the fragmentation process is re-formulated to describe the excitation spectrum of pre-fragment nuclei, The resulting spectrum is shown to be related to the many-body response of the nuclear ground-state and excited states, and an approach to simplify this function is discussed. An analytic solution to the nuclear de-excitation process is described which includes a realistic level spectrum of the GCR nuclei (A < 60), Comparisons are made to experiments for fragmentation of Mg-24, S-32, and Fe-56 beams on several targets and results are discussed. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Hampton, VA 23662 USA. Univ Tennessee, Knoxville, TN 37996 USA. RP Cucinotta, FA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 19 TC 19 Z9 21 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043468-1 J9 ADV SPACE RES PY 1998 VL 22 IS 4 BP 533 EP 537 DI 10.1016/S0273-1177(98)01075-8 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Genetics & Heredity; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Genetics & Heredity; Geology; Meteorology & Atmospheric Sciences GA BL54Y UT WOS:000075849900008 PM 11542783 ER PT S AU Curtis, SB Vazquez, ME Wilson, JW Atwell, W Kim, M Capala, J AF Curtis, SB Vazquez, ME Wilson, JW Atwell, W Kim, M Capala, J BE Vazquez, ME TI Cosmic ray hit frequencies in critical sites in the central nervous system SO LIFE SCIENCES: SPACE FLIGHT AND THE CENTRAL NERVOUS SYSTEM: THE POTENTIAL INDEPENDENT AND SYNERGISTIC EFFECTS OF MICROGRAVITY AND RADIATION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 4 Symposium of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Deut Agentur Raum Fahrt, Angelegenheiten GmbH ID HEAVY-PARTICLE IRRADIATION; HUMAN RETINA; GANGLION-CELLS; BASAL NUCLEUS; RADIATION; SPACE; NEURONS; HIPPOCAMPUS; TRANSPORT; NUMBER AB One outstanding question to be addressed in assessing the risk of exposure to space travelers from galactic cosmic rays (GCR) outside the geomagnetosphere is to ascertain the effects of single heavy-ion hits on cells in critical regions of the central nervous system (CNS), As a first step toward this end, it is important to determine how many "hits" might be received by a neural cell in several critical CNS areas during an extended mission outside the confines of the earth's magnetic field, Critical sites in the CNS: the macula, and an interior brain point (typical of the genu, thalamus, hippocampus and nucleus basalis of Meynert) were chosen for the calculation of hit frequencies from galactic cosmic rays for a mission to Mars during solar minimum (i.e., at maximum cosmic-ray intensity), The shielding at a given position inside the body was obtained using the Computerized Anatomical Man (CAM) model, and a radiation transport code which includes nuclear fragmentation was used to calculate yearly fluences at the point of interest, Since the final Mars spacecraft shielding configuration has not yet been determined, we considered the minimum amount of aluminum required for pressure vessel-wall requirements in the living quarters of a spacecraft, and a typical duty area as a pressure vessel plus necessary equipment, The conclusions are: (1) variation of the position of the "target site" within the head plays only a small role in varying hit frequencies; (2) the average number of hits depends linearly on the cross section of the critical portion of the cell assumed in the calculation; (3) for a three-year mission to Mars at solar minimum (i.e,, assuming the 1977 spectrum of galactic cosmic rays), 2% or 13% of the "critical sites" of cells in the CNS would be directly hit at least once by iron ions, depending on whether 60 mu m(2) or 471 mu m(2) is assumed as the critical cross sectional area; and (4) roughly 6 million out of some 43 million hippocampal cells and 55 thousand out of 1.8 million thalamus cell nuclei would be directly hit by iron ions at least once on such a mission for space travelers inside a simple pressure vessel. Also, roughly 20 million out of 43 million hippocampal cells and 230 thousand out of 1.8 million thalamus cell nuclei would be directly hit by one or more particles with z greater than or equal to 15 on such a mission, (C) 1998 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Fred Hutchinson Canc Res Ctr, Seattle, WA 98104 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Aerosp Rockwell, Houston, TX 77058 USA. RP Curtis, SB (reprint author), Fred Hutchinson Canc Res Ctr, MP-665,1124 Columbia St, Seattle, WA 98104 USA. NR 54 TC 25 Z9 26 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043466-5 J9 ADV SPACE RES PY 1998 VL 22 IS 2 BP 197 EP 207 DI 10.1016/S0273-1177(98)80011-2 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Neurosciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences; Neurosciences & Neurology GA BL56Q UT WOS:000075898700003 PM 11541397 ER PT S AU D'Amelio, F Fox, RA Wu, LC Daunton, NG Corcoran, ML AF D'Amelio, F Fox, RA Wu, LC Daunton, NG Corcoran, ML BE Vazquez, ME TI Effects of microgravity on muscle and cerebral cortex: A suggested interaction SO LIFE SCIENCES: SPACE FLIGHT AND THE CENTRAL NERVOUS SYSTEM: THE POTENTIAL INDEPENDENT AND SYNERGISTIC EFFECTS OF MICROGRAVITY AND RADIATION SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT F2 4 Symposium of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Deut Agentur Raum Fahrt, Angelegenheiten GmbH ID PRIMARY SOMATOSENSORY CORTEX; GLUTAMIC-ACID DECARBOXYLASE; HINDLIMB REPRESENTATION; GABAERGIC NEURONS; SOLEUS MUSCLE; RAT; MOTOR; GABA; ORGANIZATION; AFFERENTS AB The "slow" antigravity muscle adductor longus was studied in rats after 14 days of spaceflight (SF). The techniques employed included standard methods for light microscopy, neural cell adhesion molecule (N-CAM) immunocytochemistry and electron microscopy. Light and electron microscopy revealed myofiber atrophy, segmental necrosis and regenerative myofibers. Regenerative myofibers were N-CAM immunoreactive (N-CAM-IR). The neuromuscular junctions showed axon terminals with a decrease or absence of synaptic vesicles, degenerative changes, vacant axonal spaces and changes suggestive of axonal sprouting. No alterations of muscle spindles was seen either by light or electron microscopy. These observations suggest that muscle regeneration and denervation and synaptic remodeling at the level of the neuromuscular junction may take place during spaceflight. In a separate study, GABA immunoreactivity (GABA-IR) was evaluated at the level of the hindlimb representation of the rat somatosensory cortex after 14 days of hindlimb unloading by tail suspension ("simulated" microgravity). A reduction in number of GABA-immunoreactive cells with respect to the control animals was observed in layer Va and Vb. GABA-IR terminals were also reduced in the same layers, particularly those terminals surrounding the soma and apical dendrites of pyramidal cells in layer Vb. On the basis of previous morphological and behavioral studies of the neuromuscular system after spaceflight and hindlimb suspension it is suggested that after limb unloading there are alterations of afferent signaling and feedback information from intramuscular receptors to the cerebral cortex due to modifications in the reflex organization of hindlimb muscle groups. We propose that the changes observed in GABA immunoreactivity of cells and terminals is an expression of changes in their modulatory activity to compensate for the alterations in the afferent information. (C) 1998 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 San Jose State Univ Fdn, San Jose, CA 95192 USA. San Jose State Univ, San Jose, CA 95192 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP D'Amelio, F (reprint author), San Jose State Univ Fdn, 1 Washington Sq, San Jose, CA 95192 USA. NR 44 TC 5 Z9 7 U1 1 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043466-5 J9 ADV SPACE RES-SERIES PY 1998 VL 22 IS 2 BP 235 EP 244 DI 10.1016/S0273-1177(98)80015-X PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Neurosciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences; Neurosciences & Neurology GA BL56Q UT WOS:000075898700007 PM 11541401 ER PT S AU Fox, RA Daunton, NG Corcoran, ML AF Fox, RA Daunton, NG Corcoran, ML BE Vazquez, ME TI Study of adaptation to altered gravity through systems analysis of motor control SO LIFE SCIENCES: SPACE FLIGHT AND THE CENTRAL NERVOUS SYSTEM: THE POTENTIAL INDEPENDENT AND SYNERGISTIC EFFECTS OF MICROGRAVITY AND RADIATION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 4 Symposium of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Deut Agentur Raum Fahrt, Angelegenheiten GmbH ID SUDDEN FALLS; RAT; REFLEX; RESPONSES; WEIGHTLESSNESS; RECOVERY; CATS AB Maintenance of posture and production of functional, coordinated movement demand integration of sensory feedback with spinal and supra-spinal circuitry to produce adaptive motor control in altered gravity (G). To investigate neuroplastic processes leading to optimal performance in altered G we have studied motor control in adult rats using a battery of motor function tests following chronic exposure to various treatments (hyper-G, hindlimb suspension, chemical distruction of hair cells, space flight). These treatments differentially affect muscle fibers, vestibular receptors, and behavioral compensations and, in consequence, differentially disrupt air righting, swimming, posture and gait. The time-course of recovery from these disruptions varies depending on the function tested and the duration and type of treatment. These studies, with others (e.g., D'Amelio et al. in this volume), indicate that adaptation to altered gravity involves alterations in multiple sensory-motor systems that change at different rates. We propose that the use of parallel studies under different altered G conditions will most efficiently lead to an understanding of the modifications in central (neural) and peripheral (sensory and neuromuscular) systems that underlie sensory-motor adaptation in active, intact individuals. (C) 1998 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 San Jose State Univ, Dept Psychol, San Jose, CA 95192 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Fox, RA (reprint author), San Jose State Univ, Dept Psychol, San Jose, CA 95192 USA. NR 43 TC 14 Z9 14 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043466-5 J9 ADV SPACE RES PY 1998 VL 22 IS 2 BP 245 EP 253 DI 10.1016/S0273-1177(98)80016-1 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Neurosciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences; Neurosciences & Neurology GA BL56Q UT WOS:000075898700008 PM 11541402 ER PT B AU Green, JL Fung, SF Gallagher, DL Fok, MC Wilson, GR Gladstone, GR Perez, JD Reiff, PH Burch, JL Moore, TE AF Green, JL Fung, SF Gallagher, DL Fok, MC Wilson, GR Gladstone, GR Perez, JD Reiff, PH Burch, JL Moore, TE BE Xu, RL Lui, ATY TI Global-scale imaging: New approaches in magnetospheric research SO MAGNETOSPHERIC RESEARCH WITH ADVANCED TECHNIQUES SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT 9th COSPAR Colloquium CY APR 15-19, 1996 CL BEIJING, PEOPLES R CHINA SP COSPAR, Chinese Natl Comm for COSPAR, Natl Nat Sci Fdn China AB A completely different paradigm in magnetospheric research will begin with the launch of NASA's Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) in January 2000. All the instruments on IMAGE will provide global-scale measurements of various plasma regimes in the Earth's magnetosphere. The objective of the IMAGE mission is to determine the global response of the magnetosphere to changing solar wind conditions. IMAGE will address this broad objective in unique ways by using neutral atom imaging (NAI), far ultraviolet imaging (FUV), extreme ultraviolet imaging (EUV), and radio plasma imaging (RPI). The IMAGE theory and modeling team has accomplished an extensive number of simulations in order to model the response of the IMAGE instruments. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Green, JL (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Moore, Thomas/D-4675-2012; Fung, Shing/F-5647-2012 OI Moore, Thomas/0000-0002-3150-1137; 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 0-08-043330-8 J9 COSPAR COLL PY 1998 VL 9 BP 41 EP 50 PG 10 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA BM01J UT WOS:000077416500006 ER PT S AU Finger, MH AF Finger, MH BE Buccheri, R vanParadijs, J Alpar, MA TI Long-term behavior of accretion powered pulsars - BATSE observational highlights SO MANY FACES OF NEUTRON STARS SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES C, MATHEMATICAL AND PHYSICAL SCIENCES LA English DT Proceedings Paper CT NATO Advanced Study Institute on the Many Faces of Neutron Stars CY SEP 30-OCT 11, 1996 CL LIPARI, ITALY SP NATO, Adv Study Inst Program, CNR, Area Ric Palermo,, Inst Fis Cosm & Applicazioni Informat, Sci & Tech Res Council Turkey C1 NASA, Marshall Space Flight Ctr, Univ Space Res Assoc, Space Sci Lab, Huntsville, AL 35803 USA. RP Finger, MH (reprint author), NASA, Marshall Space Flight Ctr, Univ Space Res Assoc, Space Sci Lab, Huntsville, AL 35803 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0258-2023 BN 0-7923-5194-0 J9 NATO ADV SCI I C-MAT PY 1998 VL 515 BP 369 EP 383 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL82L UT WOS:000076838700021 ER PT S AU Kouveliotou, C AF Kouveliotou, C BE Buccheri, R vanParadijs, J Alpar, MA TI GRO J1744-28: The bursting pulsar SO MANY FACES OF NEUTRON STARS SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES C, MATHEMATICAL AND PHYSICAL SCIENCES LA English DT Proceedings Paper CT NATO Advanced Study Institute on the Many Faces of Neutron Stars CY SEP 30-OCT 11, 1996 CL LIPARI, ITALY SP NATO, Adv Study Inst Program, CNR, Area Ric Palermo,, Inst Fis Cosm & Applicazioni Informat, Sci & Tech Res Council Turkey AB In December 1995, a unique source was discovered with the Burst And Transient Source Experiment (BATSE) on board the Compton Gamma-Ray Observatory (CGRO). The source was an X-ray binary pulsar that also emitted a constant rate of X-ray bursts for 5 months, a combination of phenomena that had never been observed before. The Bursting Pulsar, GRO J1744-28,has a magnetic-field strength of less than or similar to 10(11) G, placing it between type I burster sources and the majority of binary X-ray pulsars. I here summarize the properties of this system as derived from observations with BATSE and the Rossi X-Ray Timing Explorer (RXTE). C1 NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. RP Kouveliotou, C (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, ES-84, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0258-2023 BN 0-7923-5194-0 J9 NATO ADV SCI I C-MAT PY 1998 VL 515 BP 385 EP 396 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL82L UT WOS:000076838700022 ER PT J AU Ryer, CH Olla, BL AF Ryer, CH Olla, BL TI Effect of light on juvenile walleye pollock shoaling and their interaction with predators SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE schooling; spatial distribution; twilight hypothesis; predator-prey; swimming speed; illumination ID EASTERN BERING SEA; THERAGRA-CHALCOGRAMMA; FOOD DISTRIBUTION; MARINE FISHES; BEHAVIOR; INTENSITY; TWILIGHT; RISK; AVOIDANCE; PATTERNS AB Research was undertaken to examine the influence of light intensity on the shoaling behavior, activity and anti-predator behavior of juvenile walleye pollock Theragra chalcogramma. Under a 12 h light/12 h dark photoperiod, juveniles displayed a diurnal shoaling and activity pattern, characterized by fish swimming in cohesive groups during the day, with a cessation of shoaling and decreased swimming speeds at night. Prior studies of schooling fishes have demonstrated distinct light thresholds below which schooling abruptly ceases. To see if this threshold effect occurs in a predominantly shoaling species, Like juvenile walleye pollock, another experiment was undertaken in which illumination was lowered by orders of magnitude, giving fish 20 min to adapt to each light intensity. Juvenile walleye pollock were not characterized by a distinct light threshold for shoaling; groups gradually dispersed as light levels decreased and gradually recoalesced as light levels increased. At light levels below 2.8 x 10(-6) mu E s(-1) m(-2), juvenile walleye pollock were so dispersed as to no longer constitute a shoal. Exposure to simulated predation risk had differing effects upon fish behavior under light and dark conditions. Brief exposure to a model predator in the dark caused fish to swim faster, for 5 or 6 min, than fish which had been similarly startled in the Light. Chronic exposure to a living predator produced similar results: fish tended to swim slower when a predator was present in the light, but faster when a predator was present in the dark. In the Light, shoaling and/or schooling provide protection against predators. But in the dark, with fish unable to see one another, increased prey activity resulting from predator disturbance may lead to accelerated dispersal of prey shoals. Thus, perceived predation risk may have different effects upon the spatial distribution of juvenile walleye pollock under light and dark conditions. This has implications for survival, as fish which have become widely scattered during the darkness may take longer to reform shoals at dawn, resulting in greater predation risk. C1 NOAA, Natl Marine Fisheries Serv, Hatfield Marine Sci Ctr,Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Grp, Newport, OR 97365 USA. RP Ryer, CH (reprint author), NOAA, Natl Marine Fisheries Serv, Hatfield Marine Sci Ctr,Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Grp, Newport, OR 97365 USA. EM cliff.ryer@hmsc.orst.edu NR 52 TC 54 Z9 54 U1 2 U2 18 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1998 VL 167 BP 215 EP 226 DI 10.3354/meps167215 PG 12 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA ZZ007 UT WOS:000074685500020 ER PT S AU Cumpston, BH Ehrlich, JE Kuebler, SM Lipson, M Marder, SR McCord-Maughon, D Perry, JW Rockel, H Rumi, M AF Cumpston, BH Ehrlich, JE Kuebler, SM Lipson, M Marder, SR McCord-Maughon, D Perry, JW Rockel, H Rumi, M BE Friedrich, CR Vladimirsky, Y TI Three-dimensional microfabrication using two-photon polymerization SO MATERIALS AND DEVICE CHARACTERIZATION IN MICROMACHINING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Materials and Device Characterization in Micromachining CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE microfabrication; two-photon absorption; photopolymerization; micro-electromechanical systems (MEMS); photonic bandgap AB Photopolymerization initiated by the simultaneous absorption of two photons is unique in its ability to produce complex three-dimensional (3D) structures from a single, thick photopolymer film. Strong 3D confinement of the polymerization process is not possible in other polymer microfabrication techniques such as LIGA, rapid prototyping, and conventional photoresist technology. Two-photon polymerization also permits the fabrication of 3D structures and the definition of lithographic features on non-planar surfaces. We have developed a wide array of chromophores which hold great promise for 3D microfabrication, as well as other applications, such as two-photon fluorescence imaging and 3D optical data storage. These materials are based on a donor-pi-donor, donor-acceptor-donor, or acceptor-donor-acceptor structural motif. The magnitude of the two-photon absorption cross-section, delta, and the position of the two-photon absorption maximum, lambda(max)((2)), can be controlled by varying the length of the conjugated bridge and by varying the strength of the donor/acceptor groups. In this way, chromophores have been developed which exhibit strong two-photon absorption in the range of 500 - 975 nm, in some cases as high as 4400 x 10(-50) cm(4) s/photon-molecule. In the case of donor-pi-donor structures, quantum-chemical calculations show that the large absorption cross-sections arise from the symmetric re-distribution of charge from the donor end-groups to the conjugated bridge, resulting in an electronic excited-state which is more delocalized than the ground state. For many of these molecules, two-photon excitation populates a state which is sufficiently reducing that a charge transfer reaction can occur with acrylate monomers. The efficiency of these processes can be described using Marcus theory. Under suitable conditions, such reactions can induce radical polymerization of acrylate resins. Polymerization rates have been measured, and we show that these two-photon chromophores display increased sensitivity and recording speed over conventional photoinitiators. Complex 3D structures can be fabricated in acrylate films doped with these chromophores using tightly focused near-infrared femtosecond laser pulses. A 3D periodic array of polymeric columns has been produced for use in photonic bandgap applications. Tapered waveguide structures for interconnecting disparate-sized optical components have been constructed. More traditional MEMS structures, such as cantilevers, have also been produced Such structures may be useful for organic vapor sensors. The two-photon photopolymerization process can be extended to other material systems, such as metallic, ceramic, and composite materials, by templating the photopolymer structures. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Perry, JW (reprint author), Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. RI Perry, Joseph/B-7191-2011 OI Perry, Joseph/0000-0003-1101-7337 NR 0 TC 0 Z9 0 U1 1 U2 12 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2971-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3512 BP 168 EP 168 DI 10.1117/12.324052 PG 1 WC Engineering, Multidisciplinary; Microscopy; Physics, Applied SC Engineering; Microscopy; Physics GA BL77N UT WOS:000076704600016 ER PT J AU Reed, BD Biaglow, JA Schneider, SJ AF Reed, BD Biaglow, JA Schneider, SJ TI Engineering issues of iridium coated rhenium rockets SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB The key to the performance and lifetime of radiation-cooled rockets is the chamber temperature capability. Temperature limitations (1370 degrees C) of current state-of-art chamber materials force the use of film cooling, which degrades rocket performance and imposes plume contamination from unburned fuel. A material system composed of a rhenium (Re) substrate and an iridium (Ir) coating has demonstrated operation, for long lifetimes (hours), at higher temperatures (2200 degrees C). The added thermal margin afforded by iridium-coated rhenium (Ir/Re) allows the virtual elimination of film cooling, leading to higher performance and cleaner spacecraft environments. In the course of developing Ir/Re rockets for flight use, some engineering issues have arisen concerning Ir/Re rocket fabrication processes, critical Re mechanical properties, Re joining methods, and Ir/Re life-limiting mechanisms. Government- and industry-sponsored efforts are addressing these concerns. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 19 TC 8 Z9 9 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1998 VL 13 IS 5 BP 757 EP 771 DI 10.1080/10426919808935297 PG 15 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 114UP UT WOS:000075627800009 ER PT S AU Huang, CK Sakamoto, JS Smart, MC Surampudi, S Wolfenstine, J AF Huang, CK Sakamoto, JS Smart, MC Surampudi, S Wolfenstine, J BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Comparison of carbon and metal oxide anode materials for rechargeable Li-ion cells SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB The state of the art (SOA) Li-ion cells utilize carbon anodes. However, to improve specific energy, energy density, and safety of cells using carbon anodes, alternative anodes must be developed. Recently, Fuji Film Inc. has suggested the use of tin oxide based anodes in Li-ion cells. It is believed that cells containing tin oxide based anodes have the potential to meet the need for NASA's future missions. As a result, we conducted an analysis to compare the performance of cells containing carbon anodes and cells containing tin oxide anodes. The comparison between these cells involved the following: 1) reaction mechanisms between Li and carbon and reaction mechanisms between Li and tin oxide, 2) half-cell and full-cell performance characteristics, 3) interactions between the anode materials and electrolyte types and compositions, and 4) the optimization of binder composition. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Huang, CK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 2 Z9 2 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 519 EP 532 PG 14 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200072 ER PT J AU Sakamoto, JS Huang, CK Surampudi, S Smart, M Wolfenstine, J AF Sakamoto, JS Huang, CK Surampudi, S Smart, M Wolfenstine, J TI The effects of particle size on SnO electrode performance in lithium-ion cells SO MATERIALS LETTERS LA English DT Article DE SnO; electrode; particle size; reversible capacity; lithium-ion ID INTERCALATION; BATTERIES AB It was observed that by decreasing the SnO particle size, while maintaining the same grain size, the reversible and initial specific capacities increased. It is believed that as the particle size decreases the number of Li-ion insertion sites increase and Li-ion diffusion distances decrease thus, increasing both the initial and reversible capacities. A reversible specific capacity of 657 mA h/g was achieved for SnO, which is one of the highest to date for insertion anodes. (C) 1998 Elsevier Science B.V. C1 UNIV CALIF IRVINE, DEPT CHEM & BIOCHEM ENGN, IRVINE, CA 92697 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. NR 16 TC 21 Z9 24 U1 3 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X EI 1873-4979 J9 MATER LETT JI Mater. Lett. PD JAN PY 1998 VL 33 IS 5-6 BP 327 EP 329 DI 10.1016/S0167-577X(97)00126-2 PG 3 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA YL028 UT WOS:A1998YL02800017 ER PT S AU Connell, JW Smith, JG Hergenrother, PM Rommel, ML AF Connell, JW Smith, JG Hergenrother, PM Rommel, ML BE Wilson, BA Hunter, BJ May, R Clements, LL TI Neat resin, adhesive and composite properties of reactive additive PETI-5 blends SO MATERIALS-THE STAR AT CENTER STAGE SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 30th International SAMPE Technical Conference on Materials - The Star at Center Stage CY OCT 20-24, 1998 CL SAN ANTONIO, TX SP Soc Adv Mat & Proc Engn DE imides containing phenylethynyl groups; phenylethynyl containing reactive additives; PETI-5; high temperature resins; adhesives; composites AB PETI-5 (5000 g/mole) is a new adhesive and composite matrix that exhibits good processability and excellent properties. However in the fabrication of complex composite parts, better processability may offer distinct advantages. In an effort to improve the processability of PETI-5, a novel reactive additive was prepared and used to formulate blends. Due to the synthetic approach, the reactive additive is a mixture of relatively simple phenylethynyl containing imides. As such, it exhibited solubility in a variety of solvents such as N-methyl-2-pyrrolidinone, a relatively low softening temperature (similar to 185 degrees C) and a low melt viscosity (similar to 1-3 poise at 250 degrees C). Neat resin blends were prepared by physically mixing imide powders of the reactive additive and PETI-5. The resultant powders were used to perform thermal and rheological characterization. Blends were also prepared by mixing NMP solutions of PETI-5 amide acid and the reactive additive (imide form). These solutions were subsequently used to prepare adhesive film and unidirectional carbon fiber tape using unsized IM-7 fiber. The reactive additive/PETI-5 blends were used to fabricate titanium adhesive panels and composites under 0.54 MPa or less for 1 hr at 350-371 degrees C. The effect of reactive additive content on the physical, rheological, adhesive and carbon fiber laminate properties was determined. One formulation exhibited a decrease in melt viscosity (i.e. improved processability) without effecting open hole compression, compression after impact properties or microcrack behavior. The neat resin, adhesive and composite properties of these reactive additive/PETI-5 blends and their cured polymers will be presented. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Connell, JW (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 9 TC 16 Z9 17 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA SN 0892-2624 BN 0-938994-80-8 J9 INT SAMPE TECH CONF PY 1998 VL 30 BP 545 EP 556 PG 12 WC Engineering, Aerospace; Engineering, Mechanical; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Materials Science, Composites SC Engineering; Materials Science GA BM34J UT WOS:000078431400052 ER PT S AU Mital, SK Murthy, PLN AF Mital, SK Murthy, PLN BE Wilson, BA Hunter, BJ May, R Clements, LL TI Quantifying uncertainties in the thermo-mechanical properties of particulate reinforced composites SO MATERIALS-THE STAR AT CENTER STAGE SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 30th International SAMPE Technical Conference on Materials - The Star at Center Stage CY OCT 20-24, 1998 CL SAN ANTONIO, TX SP Soc Adv Mat & Proc Engn DE modulus; composite mechanics; thermal conductivity; thermal expansion coefficient; particulate reinforcement AB Recently, there has been a growing interest in the use of particulate reinforced composites in a wide variety of applications. Particle reinforced composites are candidate materials for structures where shock or impact loading is expected. The ICAN (Integrated Composites Analyzer) computer code developed at NASA-Lewis Research Center has been modified to include micromechanics equations for particle reinforced composites. In this work, the simplified micromechanics of particulate reinforced composites and a fast probability integration (FPI) technique have been used to obtain the probabilistic composite behavior of a A1/SiCp (silicon carbide particles in aluminum matrix) composite. The probability density functions for composite moduli, thermal expansion coefficient and thermal conductivities along with their sensitivity factors are computed. The effect of different assumed distributions in constituent properties and the effect of reducing scatter in input random variable on a select composite property - namely the thermal expansion coefficient are also evaluated. The variations in the constituent properties that directly effect these composite properties are accounted for by assumed probabilistic distributions. The results show that the present technique provides valuable information about the scatter in composite properties and sensitivity factors, which are useful to test or design engineers. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Mital, SK (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA SN 0892-2624 BN 0-938994-80-8 J9 INT SAMPE TECH CONF PY 1998 VL 30 BP 577 EP 588 PG 12 WC Engineering, Aerospace; Engineering, Mechanical; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Materials Science, Composites SC Engineering; Materials Science GA BM34J UT WOS:000078431400055 ER PT B AU Starks, SA Kreinovich, V AF Starks, SA Kreinovich, V BE Erickson, GJ Rychert, JT Smith, CR TI Environmentally-oriented processing of multi-spectral satellite images: New challenges for Bayesian methods SO MAXIMUM ENTROPY AND BAYESIAN METHODS SE FUNDAMENTAL THEORIES OF PHYSICS LA English DT Proceedings Paper CT 17th International Workshop on Maximum Entropy and Bayesian Methods of Statistical Analysis CY AUG 04-08, 1997 CL BOISE STATE UNIV, BOISE, ID HO BOISE STATE UNIV DE satellite imaging; multi-spectral satellite data; environmental applications; Bayes Risk AB Remotely sensed images from new generation satellites present an opportunity for scientists to investigate problems in environmental and earth science which have been previously intractable. The magnitude of data that will arise from these hyperspectral instruments create the need for innovative techniques to accomplish data reduction. This paper presents an algorithm which shows promise as a tool for reducing the dimensionality of data resulting from remote sensing. The optimality criteria for the algorithm is the Bayes Risk in the reduced dimension space. C1 Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. RP Starks, SA (reprint author), Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-5047-2 J9 FUND THEOR PY 1998 VL 98 BP 271 EP 276 PG 6 WC Mathematics, Applied; Physics, Mathematical; Statistics & Probability SC Mathematics; Physics GA BM77X UT WOS:000079747300022 ER PT J AU Yan, CH Whalen, RT Beaupre, GS Sumanaweera, TS Yen, SY Napel, S AF Yan, CH Whalen, RT Beaupre, GS Sumanaweera, TS Yen, SY Napel, S TI A new frame-based registration algorithm SO MEDICAL PHYSICS LA English DT Article DE frame registration; gold standard ID MR BRAIN IMAGES; CT; FEATURES; SURGERY; PET AB This paper presents a new algorithm for frame registration. Our algorithm requires only that the frame be comprised of straight rods, as opposed to the N structures or an accurate frame model required by existing algorithms. The algorithm utilizes the full 3D information in the frame as well as a least squares weighting scheme to achieve highly accurate registration. We use simulated CT data to assess the accuracy of our algorithm. We compare the performance of the proposed algorithm to two commonly used algorithms. Simulation results show that the proposed algorithm is comparable to the best existing techniques with knowledge of the exact mathematical frame model. For CT data corrupted with an unknown in-plane rotation or translation, the proposed technique is also comparable to the best existing techniques. However, in situations where there is a discrepancy of more than 2 mm (0.7% of the frame dimension) between the frame and the mathematical model, the proposed technique is significantly better (p less than or equal to 0.05) than the existing techniques. The proposed algorithm can be applied to any existing frame without modification. It provides better registration accuracy and is robust against model mis-match. It allows greater flexibility on the frame structure. Lastly, it reduces the frame construction cost as adherence to a concise model is not required. (C) 1998 American Association of Physicists in Medicine. C1 Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Div Life Sci, Mt View, CA 94041 USA. Rehabil Res & Dev Ctr, Palo Alto, CA 94309 USA. Acuson Corp, Mt View, CA 94039 USA. Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. Stanford Univ, Dept Radiol, Stanford, CA 94305 USA. RP Yan, CH (reprint author), Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. OI Beaupre, Gary/0000-0002-6211-7621 FU NCRR NIH HHS [P41 RR09784] NR 21 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD JAN PY 1998 VL 25 IS 1 BP 121 EP 128 DI 10.1118/1.598166 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA YT938 UT WOS:000071661600015 PM 9472834 ER PT S AU Ross, MD Montgomery, K Linton, S Cheng, R Smith, J AF Ross, MD Montgomery, K Linton, S Cheng, R Smith, J BE Westwood, JD Hoffman, HM Stredney, D Weghorst, SJ TI A national center for biocomputation: In search of a patient-specific interactive virtual surgery workbench SO MEDICINE MEETS VIRTUAL REALITY: ART, SCIENCE, TECHNOLOGY: HEALTHCARE (R)EVOLUTION TM SE STUDIES IN HEALTH TECHNOLOGY AND INFORMATICS LA English DT Proceedings Paper CT Conference on Medicine Meets Virtual Reality 6 CY JAN 28-31, 1998 CL SAN DIEGO, CA AB This report describes the three-dimensional imaging and virtual environment technologies developed in NASA's Biocomputation Center for scientific purposes that have now led to applications in the field of medicine. A major goal is to develop a virtual environment surgery workbench for planning complex craniofacial and breast reconstructive surgery, and for training surgeons. C1 NASA, Ames Res Ctr, Biocomputat Ctr, Moffett Field, CA 94035 USA. RP Ross, MD (reprint author), NASA, Ames Res Ctr, Biocomputat Ctr, MS 239-11, Moffett Field, CA 94035 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU I O S PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0926-9630 BN 90-5199-386-2 J9 ST HEAL T PY 1998 VL 50 BP 323 EP 328 PG 6 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Medical Informatics SC Computer Science; Engineering; Medical Informatics GA BK86B UT WOS:000073689000052 PM 10180561 ER PT S AU Angood, PB AF Angood, PB BE Westwood, JD Hoffman, HM Stredney, D Weghorst, SJ TI Internet-based telemedicine: A practical tool? SO MEDICINE MEETS VIRTUAL REALITY: ART, SCIENCE, TECHNOLOGY: HEALTHCARE (R)EVOLUTION TM SE STUDIES IN HEALTH TECHNOLOGY AND INFORMATICS LA English DT Proceedings Paper CT Conference on Medicine Meets Virtual Reality 6 CY JAN 28-31, 1998 CL SAN DIEGO, CA AB The Institute of Medicine (IOM) has recently defined telemedicine as "the use of electronic information and communications technologies to provide and support health care when distance separates the participants." The technology used to perform telemedicine can range from a simple telephone or fax, to satellite-based relay transfers, to state of the art computer and video-conferencing equipment. In general despite a recent national and international growth in interest for telemedicine, obstacles to its widespread use persist. The expectation, however, is that telemedicine will continue to grow and flourish as the technology options are brought to the consumer market by industry. To date, the focus has been on how to bring television quality interactions to the health care providers and their patients. As the electronic age continues to progress at a logarithmic rate, however, the dominant format of successful electronic communication technology is currently the desktop computer networked through the Internet. This dominance is showing no industry or economic signs of slowdown and, therefore, telemedicine program efforts should begin to focus on the ability to communicate through this medium because of the easy access, lower costs and ease for technology upgrades. To date, only a few programs have documented experience with Internet-based telemedicine technology. The Department of Surgery at Yale University's School of Medicine and NASA recently developed a tele medicine test-bed with the Russia Space Agency, the Spacebridge to Russia Project, using multimedia computers networked via the Internet. Clinical patient consultations were accomplished in a store-and-forward modality using a variety of electronic media, packaged as digital files, and transmitted across the Internet. These Unix-based computer systems also offered the capability of real-time audio-video conferencing between remotely located users networked through the Internet. This real-time modality was utilized for medical education conferencing and group reviews of difficult patient scenarios. Overall, the spacebridge to Russia Project was an effective test-bed to show that Internet-based telemedicine could become operational and successful. Further developments in the Internet and computer technologies (hardware and software) now make this form of telemedicine communication readily accessible and cost-affordable for many health care providers - without the requirements for expensive and cumbersome telecommunications systems or networks. The Yale University program has shifted away From the Unix-based system to the more commonly utilized Intel-based systems and is actively testing a variety of technologies in several telemedicine testbeds on a national and international basis. As more institutions and telemedicine programs become involved with these technology advancements, the spectrum of services that can be offered to patients becomes broadened. Patients will become a more intimate participant in the processes of their health care and healthcare providers will become more efficient as information managers. The physicians of the future will not rely on the telephone and facsimile communication systems of today. They will necessarily become more in the way of information managers by learning to process the information from patients' clinical problems and clinical data systems through various information resources; formulating cogent responses utilizing those resources (which will also include powerful patient databases); and then effecting a solution of the patients' issues - the solutions of which will join the medical information databases in order to serve subsequent patients through an 'artificial intelligence' process. The future physician will, in many instances, then be required to transmit the results of these processes to a remote site, either to another physician, or directly to the patient, via telemedicine technology. The physician of the future will therefore practice informatics and telemedicine, as much as clinical medicine. It remains an elusive goal, however, to integrate these telemedicine concepts and practice into the process of medical education in order to prepare future health care providers with the skills and insights to unite telemedicine with daily clinical practice. In general, utilizing currently available technologies, telemedicine can now further improve the access to high-quality medical care at an affordable cost, such that distance should theoretically never be a barrier to the best medical outcomes. Telemedicine should only be limited by the advancements in future technology and the consumer acceptance of the technology, not the cability of physicians and their patients to access and apply the technology. The potential for a global health care market exists and can be adapted easily to internet-based telemedicine, Internet-based telemedicine is therefore a tool that should become an integral segment of the health care industry. C1 Yale Univ, NASA, Commercial Space Ctr Med Informat & Technol Appli, New Haven, CT 06520 USA. RP Angood, PB (reprint author), Yale Univ, NASA, Commercial Space Ctr Med Informat & Technol Appli, New Haven, CT 06520 USA. NR 0 TC 0 Z9 0 U1 1 U2 5 PU I O S PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0926-9630 BN 90-5199-386-2 J9 ST HEAL T PY 1998 VL 50 BP 383 EP 384 PG 2 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Medical Informatics SC Computer Science; Engineering; Medical Informatics GA BK86B UT WOS:000073689000071 ER PT J AU Garg, A Raj, SV Noebe, RD Nathal, MV Darolia, R AF Garg, A Raj, SV Noebe, RD Nathal, MV Darolia, R TI Plastic instability during creep deformation of a NiAl-Hf single-crystal alloy - A case study SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID PHASE AB Tensile samples from NiAl-Hf single crystals, having the same nominal composition and heat treated and creep tested under identical conditions at 1144 K, were found to exhibit very different rupture lives and creep ductilities. A case study was conducted on two samples with creep rupture lives of 343.6 and 37.0 hours (with corresponding creep ductilities of 12.3 and 39.9 pet, respectively) in order to find the causes of such a large variation in creep properties. Detailed microstructural analyses using optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) indicated that the sample with higher rupture life and lower ductility had deformed uniformly along the length of the gage section, whereas the sample with lower rupture life and higher ductility (sample L) deformed by localized plastic deformation resulting in shear failure. This shear failure was due to a plastic instability in sample L which was caused by the presence of a high density of large Hf-rich interdendritic particles that were formed during casting of the single-crystal ingot but did not go into solution during the homogenization heat treatment. The role of these particles in causing nonuniform deformation, which led to strain localization and a premature failure in sample L, has been described in detail. C1 NASA, Lewis Res Ctr, Adv Metall Branch, Cleveland, OH 44135 USA. GE Co, Aircraft Engines, Cincinnati, OH 45215 USA. NR 16 TC 5 Z9 5 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JAN PY 1998 VL 29 IS 1 BP 179 EP 189 DI 10.1007/s11661-998-0171-5 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YU733 UT WOS:000071748800019 ER PT J AU Symes, SJK Sears, DWG Akridge, DG Huang, SX Benoit, PH AF Symes, SJK Sears, DWG Akridge, DG Huang, SX Benoit, PH TI The crystalline lunar spherules: Their formation and implications for the origin of meteoritic chondrules SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID SIZE-FREQUENCY-DISTRIBUTIONS; DYNAMIC CRYSTALLIZATION; SOLAR NEBULA; REGOLITH; IMPACT; MAC88105; CHONDRITES; PETROLOGY; GLASSES; CRATER AB Crystalline lunar spherules (CLS) from three thin sections of Apollo 14 regolith breccias (14318,6; 14318,48 and 14315,20) have been examined, The objects have been classified and their abundances, size distributions, bulk compositions, and (where possible) plagioclase compositions determined. By number, 64% consist predominantly of very fine-grained equant plagioclase grains but can also contain larger (similar to 50 mu m) feldspar crystals (type X), while 22% contain plagioclase lathes in a fine-grained mafic mesostasis (type Y). Plagioclase in both spherule types displays bright yellow cathodoluminescence that is conspicuous among the blue CL of the normal feldspar of the breccias. Type Z spherules (5%) contain feldspar with blue CL and minor amounts of olivine and pyroxene. Type Q spherules (4%) contain feldspar with yellow CL but in a luminescent mesostasis (of quartz or feldspar?). A few spherules are mixtures of type Y and type X textures. Most type X spherules, and a few type Y spherules, have fine-grained opaque rims. Compound objects were also found and consist of two or more CLS that appear to have collided while still plastic or molten. The CLS are thought to be impact spherules that crystallized in free flight, their coarse textures suggesting fairly slow cooling rates (similar to <1 degrees C/s). The abundance of the CLS resembles that of chondrules in the CM chondrite Murchison, and their cumulative size-frequency distributions are very similar to those of the chondrules in several meteorite classes. The bulk compositions of the CLS do not resemble regoliths at any of the Apollo sites, including Apollo 14, or any of the common impact glasses, but they do resemble the bulk compositions of several lunar meteorites and the impact glasses they contain. The Apollo 14 site is located on a region containing Imbrium ejecta, and we suggest that the CLS derive from the Imbrium impact. Ballistic calculations indicate that only impact events of this size on the Moon are capable of producing melt spherules with the required free flight times and slow cooling rates. Smaller impacts produce glassy spherules and agglutinates. As has been pointed out many times, the CLS have many properties in common with meteoritic chondrules. While much remains unclear, difficulties with a nebular origin and new developments in chondrule chronology, studies of asteroid surfaces and impact ejecta behavior, and the present observations indicate that meteoritic chondrules could have formed by impact. C1 Univ Arkansas, Dept Chem & Biochem, Cosmochem Grp, Fayetteville, AR 72701 USA. RP Symes, SJK (reprint author), NASA, Lyndon B Johnson Space Ctr, Planetary Sci Branch, SN4, Houston, TX 77058 USA. EM steven.j.symes1@jsc.nasa.gov NR 100 TC 39 Z9 39 U1 0 U2 6 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JAN PY 1998 VL 33 IS 1 BP 13 EP 29 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YT237 UT WOS:000071579600004 ER PT J AU Zhu, YQ Navon, IM AF Zhu, YQ Navon, IM TI FSU-GSM forecast error sensitivity to initial conditions: Application to Indian summer monsoon SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID NON-LINEAR SYSTEMS; ADJOINT; MODEL AB The full-physics adjoint of the FSU Global Spectral Model of version T42L12 is applied to carry out sensitivity analysis of the localized model forecast error to the initial conditions for a case test occurring on June 8, 1988 during the Indian summer monsoon. The results show that adjoint sensitivity based on ECMWF analysis can be used to identify regions with large analysis uncertainties. The conclusion is that more observations are required over the northern Bay of Bengal to improve the quality of analyses so as to ameliorate the model forecast skill. C1 Florida State Univ, Dept Math, Tallahassee, FL 32306 USA. Florida State Univ, Supercomp Computat Res Inst, Tallahassee, FL 32306 USA. Florida State Univ, Inst Geophys Fluid Dynam, Tallahassee, FL 32306 USA. RP Zhu, YQ (reprint author), NASA, Goddard Space Flight Ctr, Data Assimilat Off, 7501 FORBES Blvd, Seabrook, MD 20706 USA. RI Navon, Ionel/A-5173-2008 OI Navon, Ionel/0000-0001-7830-7094 NR 13 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-7971 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PY 1998 VL 68 IS 1-2 BP 35 EP 41 DI 10.1007/BF01025382 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 149BU UT WOS:000077585900004 ER PT J AU Simpson, J Halverson, JB Ferrier, BS Petersen, WA Simpson, RH Blakeslee, R Durden, SL AF Simpson, J Halverson, JB Ferrier, BS Petersen, WA Simpson, RH Blakeslee, R Durden, SL TI On the role of "hot towers" in tropical cyclone formation SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID PRECIPITATION DEVELOPMENT; LIQUID WATER; TOGA COARE; ELECTRIFICATION; THUNDERSTORMS; CUMULONIMBUS; HURRICANES; MESOSCALE; RADAR; GENESIS AB The probabilistic approach to tropical cyclogenesis is advanced here by examining the role of convection in the early stages. The development of "hot towers", that is tall cumulonimbus towers which reach or penetrate the tropopause, and their role in tropical cyclogenesis is investigated in two well-documented cases of formation, namely hurricane Daisy (1958) in the Atlantic and Tropical Cyclone Oliver (1993) in the Coral Sea. The hot towers in Daisy had been intensively studied by Malkus and Riehl three decades ago but remained mainly unpublished. The dynamics of Oliver genesis by merging mesoscale vortices has been recently reported, but much of the aircraft data remained. This paper adds the evolving contribution of cumulus-scale events and their associated electrification, which was made possible by the addition of an electric field mill, a numerical cloud model and other remote sensors. In their genesis stages, Daisy and Oliver appeared very different because Daisy resulted from a deepening tropical wave in the Atlantic and the pre-Oliver vortex emerged eastward from the Australian monsoon trough. However, the vertical profiles of theta(E) in the rain areas were nearly identical, with the characteristic concave shape showing substantial midlevel minima. Therefore, both required increasing upflux of high theta(E) subcloud air in order to accomplish the formation stage, with about two hot towers each in the nascent eyewall. In both cases, partial eyewalls developed at the edge of the convection, permitting subsidence in the forming eye, which was shown to contribute to the pressure fall. The probabilistic concept proposes that any contribution to early pressure fall raises the probability of success. When the incipient storm goes through those fragile phases more rapidly, the risk of death by the onset of unfavorable large-scale factors such as wind shear or upper-level subsidence is reduced. Daisy developed in an inactive, moist environment with light, Variable winds throughout the troposphere while in Oliver, strong divergent upper outflow apparently outweighed strong wind shear, although the latter was responsible for a slow and messy development of a closed, circular eye. In both storms, the hot towers in the major rainband were taller and stronger than those in the early eyewall. One-dimensional time-dependent model runs were used to simulate both in Oliver with two important results: 1) the taller rainband clouds permitted greater high level heating, if it could be retained; and 2) greater electrification and more lighting occurred in the rainband although the partial eyewall clouds also showed strong electrification. Airborne radar, electrification measurements and models are fitted together to understand their relationship. An important result is the clear inference that fairly deep mixed phase regions existed in both eyewall and rainband, in which the DC-X aircraft experienced liquid water at temperatures colder than -40 degrees C below freezing. These results show that the claims of no supercooled liquid water in tropical cyclones require re-examination with the proper measurements of electricification that are now feasible. C1 NASA, Goddard Space Flight Ctr, Meteorol Earth Sci Directorate, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD 20771 USA. Univ Maryland, JCET, Baltimore, MD 21250 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Simpson Weather Associates, Charlottesville, VA 22901 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Simpson, J (reprint author), NASA, Goddard Space Flight Ctr, Meteorol Earth Sci Directorate, Mail Code 912, Greenbelt, MD 20771 USA. NR 49 TC 55 Z9 59 U1 1 U2 6 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-7971 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PY 1998 VL 67 IS 1-4 BP 15 EP 35 DI 10.1007/BF01277500 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 145MD UT WOS:000077374300004 ER PT J AU Druyan, LM AF Druyan, LM TI The role of synoptic systems in the interannual variability of Sahel rainfall SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID AFRICAN WAVE DISTURBANCES; PHASE III; PARAMETERIZATION; SENSITIVITY; CLIMATE; IMPACTS; GATE AB Components of the June-September climate over the Sahel are investigated in simulations with the GCM of the NASA/Goddard Institute for Space Studies, forced by SST observed during 1987 and 1988. The study analyzes the role of the synoptic patterns in determining precipitation differences between the two seasons, with special attention given to African wave disturbances (AWD). Emphasis is placed on deducing the characteristics of individual systems which may be missed by spectral and/or composite analyses. Results are derived from time-longitude cross-sections and spatial distributions of daily and weekly averages of key climatological variables. Despite the overall rainier season, rainless AWD are more prevalent in the simulations corresponding to June-September 1988 forcing than for 1987. Daily precipitation is shown to be highly correlated with mid-tropospheric vorticity, near surface convergence and 200 mb divergence. August daily rainfall was somewhat better correlated with implied large scale vertical motion for 1988 forcing, emphasizing the dominance of broad circulation influences during that summer. While significant rainfall variability is attributed to AWD, quasistationary mechanisms cannot be ignored. In these simulations, upper tropospheric divergence modulated by changes in the Tropical Easterly Jet serves to both intensify the rainfall triggered by AWD and to sustain broader rainfall patterns during events of "massive uplift". C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY USA. RP Druyan, LM (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. NR 25 TC 10 Z9 10 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-7971 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PY 1998 VL 65 IS 1-2 BP 55 EP 75 DI 10.1007/BF01030269 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZG030 UT WOS:000072958000005 ER PT J AU Huang, LK Cebula, RP Hilsenrath, E AF Huang, LK Cebula, RP Hilsenrath, E TI Determination of deuterium lamp irradiance drift in the SSBUV laboratory SO METROLOGIA LA English DT Article; Proceedings Paper CT 6th International Conference on Radiometry (NEWRAD 97) CY OCT 27-29, 1997 CL TUCSON, ARIZONA ID SOLAR AB National Institute of Standards and Technology (NIST)-traceable deuterium are (D-2) lamps are used in the Shuttle Solar Backscatter Ultraviolet (SSBUV) programme as radiometric standards in the 200 nm to 250 nm wavelength region. These lamps are inherently less stable than the quartz-halogen tungsten filament (FEL) lamps used in the programme for calibration at longer wavelengths. In order to monitor changes in the D-2 lamp output, the SSBUV D-2 lamp irradiance measurements have been compared with FEL lamp irradiance measurements. Techniques have been developed to reduce noise in the SSBUV measurements and to analyse the stability of the FEL lamps. The D-2 lamp irradiance drifts have been found to be as large as -13% at 200 nm relative to 250 nm over a period of about seven years. These independently-derived D-2 lamp irradiance drifts agree with the NIST measurements of the SSBUV lamps, confirming the long-term stability of the NIST working standards for lamp irradiance in the 200 nm to 250 nm wavelength region. The D-2 lamp irradiances used for the SSBUV calibrations are those reported by the NIST, corrected for the lamp drift at the time of the instrument calibration. These derived D-2 lamp irradiances not only fill long-term gaps for which no updated NIST calibrations are available, but also allow any short-term changes to be traced in situ from a NIST calibration to the user's laboratory, thus improving the accuracy of the SSBUV instrument's calibration. C1 Raytheon STX Corp, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Huang, LK (reprint author), Raytheon STX Corp, Lanham, MD 20706 USA. NR 14 TC 1 Z9 2 U1 0 U2 1 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1998 VL 35 IS 4 BP 373 EP 379 DI 10.1088/0026-1394/35/4/26 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 168NL UT WOS:000078699100026 ER PT J AU Huang, LK Cebula, RP Hilsenrath, E AF Huang, LK Cebula, RP Hilsenrath, E TI New procedure for interpolating NIST FEL lamp irradiances SO METROLOGIA LA English DT Article; Proceedings Paper CT 6th International Conference on Radiometry (NEWRAD 97) CY OCT 27-29, 1997 CL TUCSON, ARIZONA AB The Shuttle Solar Backscatter Ultraviolet (SSBUV) programme uses 1000 W, quartz-halogen, tungsten coiled filament (FEL) lamps as the primacy radiometric calibration source in the 250 nm to 405 nm wavelength region. The National Institute for Standards and Technology (NIST) recommends using the product of a fifth-order polynomial and a Planck function as a fitting function for interpolating the NIST-calibrated FEL lamp irradiances to users' wavelengths. The NIST fitting procedure can result in more than a 1% overshoot in some data sets. This problem is related to the unconstrained properties of the fifth-order polynomial. Overshooting during lamp irradiance interpolation gives rise to corresponding errors in the SSBUV calibration and solar spectral irradiance measurements. Errors of this magnitude are unacceptably large for the SSBUV, and we have therefore developed a new interpolation scheme. A new fitting procedure has been developed to replace the NIST procedure in the SSBUV calibrations. Although it uses fewer fitting parameters, the new fitting function provides a better fit than the NIST fitting function does. The overshoot problems experienced with the MST procedure do not exist in the newly interpolated lamp irradiances. We have also investigated the properties of the NIST FEL lamp interpolation scheme in the visible and near-infrared ranges, finding that the overshoot problem experienced in the ultraviolet extends into these regions, with potential errors of the order of 0.5% to 1%. C1 Raytheon STX Corp, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Huang, LK (reprint author), Raytheon STX Corp, Lanham, MD 20706 USA. NR 9 TC 10 Z9 14 U1 1 U2 3 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1998 VL 35 IS 4 BP 381 EP 386 DI 10.1088/0026-1394/35/4/27 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 168NL UT WOS:000078699100027 ER PT J AU Bruegge, CJ Chrien, NL Diner, DJ Kahn, RA Martonchik, JV AF Bruegge, CJ Chrien, NL Diner, DJ Kahn, RA Martonchik, JV TI MISR radiometric uncertainty analyses and their utilization within geophysical retrievals SO METROLOGIA LA English DT Article; Proceedings Paper CT 6th International Conference on Radiometry (NEWRAD 97) CY OCT 27-29, 1997 CL TUCSON, ARIZONA AB The Multi-angle Imaging SpectroRadiometer (MISR) is to be launched with the Earth Observing System EOS-AM1 spacecraft in 1999. Demanding specifications include a requirement that the instrument be calibrated, and placed on an accurate radiometric scale, to within 3% (1 sigma) uncertainty, for incident radiances near the upper end of a camera's dynamic range. Contributing factors to the uncertainty in radiance measurements include signal-to-noise ratio, goodness of fit of the calibration data to a quadratic equation, and quality of the experimental conditions (i.e. range and number of radiometric levels used to provide the calibration). These sources, as they are identified, are flagged as contributing to the absolute, relative band-to-band, relative camera-to-camera, or relative pixel-to-pixel radiance uncertainties. This paper summarizes the products and results from the uncertainty analysis of radiometric calibrations for the MISR. It also provides an example of a geophysical product retrieval that makes use of these data. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bruegge, CJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Kahn, Ralph/D-5371-2012 OI Kahn, Ralph/0000-0002-5234-6359 NR 12 TC 10 Z9 10 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1998 VL 35 IS 4 BP 571 EP 579 DI 10.1088/0026-1394/35/4/61 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 168NL UT WOS:000078699100061 ER PT J AU Johnson, BC Barnes, PY O'Brian, TR Butler, JJ Bruegge, CJ Biggar, S Spyak, PR Pavlov, MM AF Johnson, BC Barnes, PY O'Brian, TR Butler, JJ Bruegge, CJ Biggar, S Spyak, PR Pavlov, MM TI Initial results of the bidirectional reflectance characterization round-robin in support of EOS SO METROLOGIA LA English DT Article; Proceedings Paper CT 6th International Conference on Radiometry (NEWRAD 97) CY OCT 27-29, 1997 CL TUCSON, ARIZONA AB Laboratory measurements of the bidirectional reflectance distribution function (BRDF) of diffusely reflecting samples are required to support calibration in the Earth Observing System (EOS) programme of the National Aeronautics and Space Administration (NASA). To assess the ability of the instrument calibration laboratories to perform accurate BRDF measurements, a round-robin comparison with the National Institute of Standards and Technology (NIST) as the central laboratory was initiated by the EOS Project Science Office. The comparison parameters, which include measurement wavelength, spectral bandwidth, illumination and viewing geometry, sample type and alignment, and data format, were selected in consultation with the participants. The participants were selected based on their roles as metrology laboratories with direct connections to EOS or other international Earth remote-sensing satellite programmes. This paper briefly describes the format of the comparison, the status of the first round, and some preliminary results. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NASA, Goddard Space Flight Ctr, Space Geodesy Networks & Sensor Calibrat Off, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. Univ Arizona, Ctr Opt Sci, Remote Sensing Grp, Tucson, AZ 85721 USA. Hughes Santa Barbara Remote Sensing, Goleta, CA 93117 USA. RP Johnson, BC (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. RI Butler, James/D-4188-2013 NR 16 TC 7 Z9 7 U1 0 U2 2 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1998 VL 35 IS 4 BP 609 EP 613 DI 10.1088/0026-1394/35/4/66 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 168NL UT WOS:000078699100066 ER PT J AU Jaross, G Krueger, AJ Flittner, D AF Jaross, G Krueger, AJ Flittner, D TI Multispectral calibration of remote-sensing instruments over Antarctica SO METROLOGIA LA English DT Article; Proceedings Paper CT 6th International Conference on Radiometry (NEWRAD 97) CY OCT 27-29, 1997 CL TUCSON, ARIZONA ID SOUTH-POLE; ULTRAVIOLET; REFLECTION; SURFACE; DESERT; MODEL; SNOW AB We discuss a technique for validation of instrument radiometric calibration using the surface of Antarctica. The proposed method involves comparing remotely-sensed radiances with predictions from a radiative transfer model, and is applicable to polar-orbiting instruments measuring in the wavelength range 335 nm to 650 nm. Coincident ground measurements are not necessary. We have estimated uncertainties in the method using existing ground measurements and Total Ozone Mapping Spectrometers (TOMS) data. Significant sources of uncertainty (1 sigma) include ground-measurement accuracy (1 %), seasonal and spatial surface variation (0.5 %), and radiative-transfer modelling (2 %). C1 STX Corp, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Inst Atmospher Phys, Tucson, AZ 85721 USA. RP Jaross, G (reprint author), STX Corp, 4400 Forbes Blvd, Lanham, MD 20706 USA. NR 18 TC 6 Z9 6 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1998 VL 35 IS 4 BP 625 EP 629 DI 10.1088/0026-1394/35/4/69 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 168NL UT WOS:000078699100069 ER PT J AU Thome, K Schiller, S Conel, J Arai, K Tsuchida, S AF Thome, K Schiller, S Conel, J Arai, K Tsuchida, S TI Results of the 1996 Earth Observing System vicarious calibration joint campaign at Lunar Lake Playa, Nevada (USA) SO METROLOGIA LA English DT Article; Proceedings Paper CT 6th International Conference on Radiometry (NEWRAD 97) CY OCT 27-29, 1997 CL TUCSON, ARIZONA ID RADIOMETRIC CALIBRATION AB A joint campaign was held at Lunar Lake Playa, Nevada (USA) in June 1996 to evaluate the accuracy of reflectance-based, vicarious calibrations of Earth Observing Systems (EOS), Four groups participated in the campaign and made independent measurements of surface reflectance and atmospheric transmittance on five different days. Each group predicted top-of-the-atmosphere radiance for several bands in the 400 nm to 2500 nm spectral range. Analysis of the data showed differences of the order of 5% to 10% throughout the spectral region under study. Further study revealed that the major sources of discrepancy are differences in procedures and assumptions in finding the reflectance of field references used to determine the surface reflectance of the test site. Differences caused by varying radiative transfer codes and aerosol assumptions were found to be a relatively small error source, owing to the high reflectance and low turbidity of the test site. Differences in the solar irradiance values used by separate groups were found to be significant, but can be overcome by agreeing on a standard solar irradiance data set. The results from this campaign were used to plan a follow-up campaign in June 1997 that included developing a set of laboratory measurements to characterize the field radiometers which measure surface reflectance, and obtaining a consistent set of reference-panel reflectance factors. The expectation is that disagreement in absolute radiances at the top of the atmosphere generated by these field methods will be reduced to less than 3% if further cooperative work between groups is carried out to develop approaches which will account better for reference panel calibration, the consistent use of atmospheric characterization and radiative transfer codes. C1 Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA. S Dakota State Univ, Dept Phys, Brookings, SD 57007 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Saga Univ, Dept Informat Sci, Saga 840, Japan. Geol Survey Japan, Environm Geol Dept, Tsukuba, Ibaraki 305, Japan. RP Thome, K (reprint author), Univ Arizona, Ctr Opt Sci, POB 210094, Tucson, AZ 85721 USA. RI Thome, Kurtis/D-7251-2012 NR 14 TC 25 Z9 25 U1 0 U2 4 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1998 VL 35 IS 4 BP 631 EP 638 DI 10.1088/0026-1394/35/4/70 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 168NL UT WOS:000078699100070 ER PT J AU Markham, BL Schafer, JS Wood, FM Dabney, PW Barker, JL AF Markham, BL Schafer, JS Wood, FM Dabney, PW Barker, JL TI Monitoring large-aperture spherical integrating sources with a portable radiometer during satellite instrument calibration SO METROLOGIA LA English DT Article; Proceedings Paper CT 6th International Conference on Radiometry (NEWRAD 97) CY OCT 27-29, 1997 CL TUCSON, ARIZONA AB A National Institute of Standards and Technology (NIST)-designed radiometer is being used to monitor the spherical integrating sources (SISs) used to radiometrically calibrate the Enhanced Thematic Mapper Plus (ETM+), an Earth-imaging sensor on the Landsat-7 satellite. This six-channel Landsat Transfer Radiometer (LXR) uses witness filter samples from the first four bands of the ETM+ along with two 10 nm bandpass filters centred at 441 nm and 662 nm, The ETM+ band 1 is 450 nm to 515 nm; band 2 is 525 nm to 600 nm; band 3 is 630 nm to 690 nm and band 4 is 775 nm to 900 nm. This monitor aids in characterizing the ETM+ stability with time and also provides an alternate radiometric scale for calibration. LXR measurements, which are taken off-axis while the ETM+ views the SIS on-axis, have documented changes as large as 7% in the SIS outputs in some of the ETM+ bandpasses, The ETM+ responses to the SIS have changed comparably, demonstrating ETM+ stability to within about 1%, LXR measurements have also shown that the linearity of the ETM+ response to radiance is about an order of magnitude better than that possible without the simultaneous measurements. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Raytheon ITSS, Lanham, MD 20706 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Markham, BL (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. RI Schafer, Joel/A-3978-2010; Dabney, Philip/C-9976-2013; Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 3 TC 17 Z9 19 U1 2 U2 6 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1998 VL 35 IS 4 BP 643 EP 648 DI 10.1088/0026-1394/35/4/72 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 168NL UT WOS:000078699100072 ER PT J AU Jaross, G Krueger, AJ Wellemeyer, C AF Jaross, G Krueger, AJ Wellemeyer, C TI Sensitivity of Total Ozone Mapping Spectrometer products to diffuse reflectance measurements SO METROLOGIA LA English DT Article; Proceedings Paper CT 6th International Conference on Radiometry (NEWRAD 97) CY OCT 27-29, 1997 CL TUCSON, ARIZONA ID CALIBRATION; TOMS; INSTRUMENT; DESIGN AB Total column ozone (O-3) amount and an aerosol index are among the geophysical properties currently retrieved from Total Ozone Mapping Spectrometer (TOMS) measurements. The accuracy with which each is retrieved depends in part on the characterization of diffuser plates used in the pre-launch instrument calibration. We present here the retrieval sensitivities to errors in the measured reflectance per steradian of these diffuser plates. In particular, errors in the wavelength dependence of the reflectance are much more important than absolute reflectance errors. We derive limits for the uncertainty of initial diffuser measurements based on reasonable goals for retrieval uncertainties: a relative standard uncertainty of 1% in total ozone and a standard uncertainty of 0.5 in aerosol optical depth. The maximum allowed la uncertainty in diffuser reflectance is 0.4% for ozone and 0.25% for optical depth, assuming that errors at different wavelengths are uncorrelated. We also examine TOMS diffuser measurements made at the Goddard Space Flight Center (GSFC) in an attempt to evaluate existing diffuser uncertainty components for O-3 and aerosol retrievals. C1 Raytheon STX Corp, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Jaross, G (reprint author), Raytheon STX Corp, 4400 Forbes Blvd, Lanham, MD 20706 USA. NR 18 TC 7 Z9 7 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 1998 VL 35 IS 4 BP 663 EP 668 DI 10.1088/0026-1394/35/4/75 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 168NL UT WOS:000078699100075 ER PT J AU Cebula, RP Huang, LK Hilsenrath, E AF Cebula, RP Huang, LK Hilsenrath, E TI SSBUV sensitivity drift determined using solar spectral irradiance measurements SO METROLOGIA LA English DT Article; Proceedings Paper CT 6th International Conference on Radiometry (NEWRAD 97) CY OCT 27-29, 1997 CL TUCSON, AZ ID DECLINING PHASE; OZONE DATA; CALIBRATION; SOLAR-CYCLE-22; STRATOSPHERE; VARIABILITY; FLIGHT AB The Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment flew eight Space Shuttle missions between 1989 and 1996, in order to maintain and validate the calibrations of a number of satellite-borne ozone-monitoring instruments. The SSBUV sensitivity drifted during each mission. Reversible drifts resulted from the outgassing of the optics, while non-reversible drifts were the consequence of changes induced by solar UV radiation. These changes varied from mission to mission, but were typically less than 1% near 400 nm, increasing to 5% to 10% near 200 nm. In addition to using traditional calibration data, the SSBUV solar irradiance data were used to assess radiometric sensitivity changes. In the near- and mid-UV, short-term solar irradiance variations can be accurately modelled using the Mg II index. Therefore, during the course of each relatively brief Shuttle flight, the Mg II index-corrected solar irradiance provides a "constant candle" and any changes in the observed solar irradiance result from sensitivity drift. Using the Sun as a source, SSBUV sensitivity drifts were modelled via an iterative approach as the product of linear functions of outgassing time and accumulated solar exposure time. The resulting time-dependent corrections were validated using the conventional calibration data and used in conjunction with the absolute radiometric sensitivity determined in the laboratory to process the solar irradiance data. It is shown that the application of this technique reduces the uncertainty in the SSBUV solar measurements associated with radiometric sensitivity drifts to approximately 1% at 200 nm. C1 Raytheon STX Corp, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Cebula, RP (reprint author), Raytheon STX Corp, Lanham, MD 20706 USA. NR 26 TC 5 Z9 5 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0026-1394 EI 1681-7575 J9 METROLOGIA JI Metrologia PY 1998 VL 35 IS 4 BP 677 EP 683 DI 10.1088/0026-1394/35/4/77 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 168NL UT WOS:000078699100077 ER PT B AU Eyre, B Blosiu, J Wiberg, D AF Eyre, B Blosiu, J Wiberg, D GP IEEE TI Taguchi optimization for the processing of Epon SU-8 resist SO MICRO ELECTRO MECHANICAL SYSTEMS - IEEE ELEVENTH ANNUAL INTERNATIONAL WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 11th Annual International Workshop on Micro Electro Mechanical Systems CY JAN 25-29, 1998 CL HEIDELBERG, GERMANY SP IEEE, Robot & Automat Soc, ASME, Div Dynam Syst & Control, Minist Econ Affairs Baden Wurttemberg AB Using the Taguchi technique an optimization experiment was performed to characterize the processing of Epon SU-8 negative photoresist. This photoresist has proven to be very sensitive to process variations and difficult to use. The Taguchi method reveals output sensitivity to variations in control factors. Using five processing parameters as control factors, experiments were performed and results were evaluated by comparison to ideal output characteristics, Analyzing the results, a proposed fabrication process was derived from optimizing the control factors for the best overall mean across all the outputs. The experiment was repeated for three film thicknesses: 50 mu m; 100 mu m, and 220 mu m. The desired output characteristics were straight sidewall profile, fine fine and space resolution, and adhesion to substrate. Tables shaw optimized processing parameters for these three film thicknesses. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Eyre, B (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RI Eyre, Bradley/C-2527-2013 OI Eyre, Bradley/0000-0001-5502-0680 NR 0 TC 25 Z9 30 U1 1 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4412-X PY 1998 BP 218 EP 222 DI 10.1109/MEMSYS.1998.659757 PG 3 WC Automation & Control Systems; Engineering, Biomedical; Engineering, Electrical & Electronic; Engineering, Mechanical SC Automation & Control Systems; Engineering GA BK78X UT WOS:000073380900039 ER PT J AU Su, CH Lehoczky, SL AF Su, CH Lehoczky, SL TI The influence of reduced gravity on the crystal growth of semiconductors - A review of US flight experiments SO MICROGRAVITY SCIENCE AND TECHNOLOGY LA English DT Article ID BRIDGMAN-STOCKBARGER GROWTH; CHEMICAL-VAPOR TRANSPORT; DIRECTIONAL SOLIDIFICATION; MAGNETIC-FIELDS; ZERO GRAVITY; MICROGRAVITY; SEGREGATION; ALLOYS; SYSTEM; HGCDTE AB The imperfections in the grown crystals of semiconducting materials, such as compositional non-uniformity, dopant segregation and crystalline structural defects, are detrimental to the performance of the opto-electronic devices. Some of these imperfections carl be attributed to effects caused by Earth gravity during crystal growth process and four ar eas have been identified as the uniqueness of material processing in reduced gravity environment. The significant results of early U.S. flight experiments, i.e. prior to Space Shuttle era, are briefly reviewed followed by an elaborated review on the recent flight experiments conducted on the shuttle missions, nle results are presented in the categories of two major growth methods for semiconducting materials. melt and vapor growth. Each of the significant results of the flight experiments is attributed to one of the four effects of reduced gravity and the unresolved problems on the measured mass fluxes in some of the vapor transport flight experiments are discussed. C1 NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. RP Su, CH (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. NR 36 TC 2 Z9 2 U1 0 U2 1 PU CARL HANSER VERLAG PI MUNICH PA KOLBERGERSTRASSE 22, POSTFACH 86 04 20, D-81679 MUNICH, GERMANY SN 0938-0108 J9 MICROGRAVITY SCI TEC JI Microgravity Sci. Technol. PY 1998 VL 11 IS 1 BP 17 EP 22 PG 6 WC Engineering, Aerospace; Thermodynamics; Mechanics SC Engineering; Thermodynamics; Mechanics GA 161CQ UT WOS:000078271200003 ER PT J AU Struk, PM Ackerman, M Nayagam, V Dietrich, DL AF Struk, PM Ackerman, M Nayagam, V Dietrich, DL TI On calculating burning rates during fiber supported droplet combustion SO MICROGRAVITY SCIENCE AND TECHNOLOGY LA English DT Article ID METHANOL AB A popular experimental technique in studying the combustion of fuel droplets is to suspend the droplet on a support fiber. One effect of the support fiber is to distort the shape of the fuel droplet. Various methods exist to report an equivalent lent droplet diameter for the distorted droplet. These methods include a diameter based on ellipsoidal volume, projected area, actual volume, surface area, and the diameter of the droplet at a 45 degrees angle to the fiber: This paper compares these differ ent techniques using experimental data Gfr om normal and reduced gravity experiments) and a new model which predicts droplet profiles. The model uses the Laplace-Young equation which describes the static equilbirium shape of the droplet. The results of the comparison show that different methods of completing equivalent diameter. deviate as the droplet size decreases relative to the size of the support fiber. The deduced burning rates can vary by as much as 12% for droplets approximately 1.5 mm in initial diameter on a 0.125 nm support fiber. Data from the model show that all equivalent diameters produce linear burning rate plots suggesting that the droplet shape does not play a role in the experimentally observed non-uniform burning rate. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. RP Struk, PM (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Mail Stop 110-3, Cleveland, OH 44135 USA. RI Struk, Peter/M-1651-2013 OI Struk, Peter/0000-0001-8221-8369 NR 19 TC 13 Z9 14 U1 0 U2 4 PU CARL HANSER VERLAG PI MUNICH PA KOLBERGERSTRASSE 22, POSTFACH 86 04 20, D-81679 MUNICH, GERMANY SN 0938-0108 J9 MICROGRAVITY SCI TEC JI Microgravity Sci. Technol. PY 1998 VL 11 IS 4 BP 144 EP 151 PG 8 WC Engineering, Aerospace; Thermodynamics; Mechanics SC Engineering; Thermodynamics; Mechanics GA 224NG UT WOS:000081904700002 ER PT J AU Nicolas, DP AF Nicolas, DP TI Export laws and regulations applied to scientific publications and presentations SO MICROSCOPY RESEARCH AND TECHNIQUE LA English DT Meeting Abstract C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1059-910X J9 MICROSC RES TECHNIQ JI Microsc. Res. Tech. PD JAN 1 PY 1998 VL 40 IS 1 BP 83 EP 83 PG 1 WC Anatomy & Morphology; Biology; Microscopy SC Anatomy & Morphology; Life Sciences & Biomedicine - Other Topics; Microscopy GA YP292 UT WOS:000071262300020 ER PT S AU Liao, L Meneghini, R Iguchi, T AF Liao, L Meneghini, R Iguchi, T BE Hayasaka, T Wu, DL Jin, YQ Jiang, JS TI A simulation of air/space-borne radar rain path attenuation estimation using the mirror image radar return SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment CY SEP 15-17, 1998 CL BEIJING, PEOPLES R CHINA SP SPIE Int Soc Opt Engn, Natl Ctr Atmospher Res, Atmospher Chem Div (USA), Chinese Acad Sci, Inst Atmospher Physics, CSSR Chinese Soc Space Res, COEMA DE air/space-borne radar; rain; attenuation; scattering; TRMM AB The mirror image rain echo, received through the double reflection of the radar from the surface, may provide useful information in estimating the rainfall rate from airborne and spaceborne weather radars. As the TRMM spaceborne weather radar has been successfully launched recently, issues regarding the utility of this measurement are pertinent and timely. In this study, having described a mirror image model, which yields the co- and cross-polarized components of the mirror image and bistatic returns as a function of the radar parameters and the scattering properties of the rain and surface, several algorithms to estimate the path attenuation based on the mirror image returns are constructed. These methods generally use a difference (in dB) between the direct and mirror image radar returns where the returns are taken at equally distant ranges above and 'below' the surface. In some implementations of the algorithm the return power from the surface is used as well. To test the accuracy of these algorithms, the direct, mirror image and surface return powers are generated from measured raindrop size distributions, a surface scattering model and a mirror-image scattering model. These models can be used to control the characteristics of the rain profiles (rain intensity and vertical structure) as well as the surface scattering characteristics. Comparisons between the mirror-image and the surface reference techniques are made for various rain intensities, vertical rain profiles and surface scattering characteristics. In the final part of the paper, some preliminary results of comparisons of the mirror image algorithms with the surface reference technique are given using data from the TRMM Precipitation Radar. C1 NASA, Goddard Space Flight Ctr, Caelum Res Corp, Greenbelt, MD 20771 USA. RP Liao, L (reprint author), NASA, Goddard Space Flight Ctr, Caelum Res Corp, Code 975, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2962-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3503 BP 124 EP 134 DI 10.1117/12.319500 PG 5 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BL83S UT WOS:000076894000017 ER PT S AU Prabhakara, C Iacovazzi, R Yoo, JM Dalu, G AF Prabhakara, C Iacovazzi, R Yoo, JM Dalu, G BE Hayasaka, T Wu, DL Jin, YQ Jiang, JS TI Global warming estimation from MSU SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment CY SEP 15-17, 1998 CL BEIJING, PEOPLES R CHINA SP SPIE Int Soc Opt Engn, Natl Ctr Atmospher Res, Atmospher Chem Div (USA), Chinese Acad Sci, Inst Atmospher Physics, CSSR Chinese Soc Space Res, COEMA DE global warming; microwave remote sensing; calibration errors; diurnal cycle AB In this study, we develop an independent method to derive global temperature trend from Microwave Sounding Unit (MSU) radiometer observations in Ch 2 (53.74 GHz), made from sequential, sun-synchronous, polar-orbiting NOAA operational satellites. Also, a detailed examination of the systematic errors in these data is performed with the objective to improve this method. Partitioning these data from 75 N to 75 S into global land and ocean sets, and further subdividing them into am and pm subsets with the help of the LECT, enables us to perform this examination. The systematic errors in the MSU Ch 2 data are mainly related to differences in the MSU instrument calibration and the Local Equatorial Crossing Times (LECT) of successive satellites. They can be removed from these data with the help of the overlapping observations made by successive satellites. Errors in the MSU Ch 2 data are also introduced by orbital drift, which is the progressive change in the LECT of a satellite. Changes of the AM and PM observation times due to orbital drift causes Ch 2 brightness temperatures from each satellite to be affected by the diurnal cycle. In addition, orbital drift alters satellite illumination by sun, and thereby the instrument calibration. These errors introduced by orbital drift cannot be eliminated objectively. However, in this study, the uncertainty in the global temperature trend resulting from the cumulative error generated by drifts of all the satellites is inferred with an indirect approach. Based on our method of analysis of the MSU Ch 2 data, we find a global temperature trend from 1980 to 1996 of 0.11 K decade(-1) with an uncertainty of 0.06 K decade(-1). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Prabhakara, C (reprint author), NASA, Goddard Space Flight Ctr, Code 913, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2962-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3503 BP 178 EP 184 DI 10.1117/12.319487 PG 5 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BL83S UT WOS:000076894000023 ER PT S AU Wu, DL AF Wu, DL BE Hayasaka, T Wu, DL Jin, YQ Jiang, JS TI Remote sensing of clouds and water vapor by microwave limb sounding SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment CY SEP 15-17, 1998 CL BEIJING, PEOPLES R CHINA SP SPIE Int Soc Opt Engn, Natl Ctr Atmospher Res, Atmospher Chem Div (USA), Chinese Acad Sci, Inst Atmospher Physics, CSSR Chinese Soc Space Res, COEMA DE millimeter and submillimeter-wave; remote sensing; cloud ice content; cloud scattering; cloud emission AB Passive radiometers at 100-700 GHz offer great potential for remote sensing of cirrus clouds and upper-tropospheric water vapor from space because radiation at these frequencies can penetrate and interact with cirrus clouds without being cut off at/near cloud surface. This paper focuses mostly on satellite microwave observations from UARS MLS (Upper Atmosphere Research Satellite Microwave Limb Sounder) at 186.5 and 203.2 GHz. Advantages of limb-viewing geometry include better vertical resolution and less contamination of Earth's surface conditions since the limb background radiance depends only on pointing and water vapor abundance. MLS radiance measurements show that water vapor and cloud signals are separable with frequencies of different sensitivities to water vapor. The cloud-induced radiances can be used to directly retrieve ice water content at 14-18km altitudes if the ice particles are smaller than 100 microns. Model simulations at these frequencies are also presented for various cloud types and heights. With the modified MLS radiative transfer model, we are able to simulate limb and nadir radiances at all frequencies between 10 and 1000GHz for both cloudy and clear atmospheres. Our sensitivity studies show that brightness temperature depression at the lowest MLS tangent height can be used to infer cloud height and ice content in the upper troposphere. With more channels near 122, 240, and 640 GHz, we find that the chance of separating cirrus cloud and water vapor is greatly enhanced, and these radiometers are to be flown as the future MLS on board NASA CHEM-1 spacecraft. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wu, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Wu, Dong/D-5375-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2962-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3503 BP 322 EP 331 DI 10.1117/12.319508 PG 4 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BL83S UT WOS:000076894000040 ER PT S AU Karasik, BS Skalare, A McGrath, WR Bumble, B LeDuc, HG Barner, JB Kleinsasser, AW Burke, PJ Schoelkopf, RJ Prober, DE AF Karasik, BS Skalare, A McGrath, WR Bumble, B LeDuc, HG Barner, JB Kleinsasser, AW Burke, PJ Schoelkopf, RJ Prober, DE BE Afsar, MN TI Low-noise and wideband hot-electron superconductive mixer for THz frequencies SO MILLIMETER AND SUBMILLIMETER WAVES IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 4th International Conference on Millimeter and Submillimeter Waves and Applications CY JUL 20-23, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Tufts Univ DE submillimeter; heterodyne; mixer; hot electron bolometer; terahertz; superconductor; far infrared; high-T-c ID YBA2CU3O7-DELTA THIN-FILM; TEMPERATURE-GROWN GAAS; BOLOMETRIC MIXERS; TERAHERTZ APPLICATIONS; BANDWIDTH; FABRICATION; PHOTOMIXERS; POWER AB Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range from 1.1 THz to 2.5 THz. The mixer device is a 0.15-0.3 mu m microbridge made from a 10 nm thick Nb film. This device employs diffusion as a cooling mechanism for hot electrons. The double sideband noise temperature was measured to be less than or equal to 3000 K at 2.5 THz and the mixer IF bandwidth is expected to be at least 10 GHz for a 0.1 mu m long device; The local oscillator (LO) power dissipated in the HEB microbridge was 20-100 nW. Further improvement of the mixer characteristics can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated. The HEB mixer is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies. HEB receivers are planned for use on the NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) and the ESA Ear Infrared and Submillimeter Space Telescope (FIRST). The prospects of a submicron-size YBa2Cu3O7-delta (YBCO) HEB are discussed. The expected LO power of 1-10 mu W and SSB noise temperature of approximate to 2000 K may make this mixer attractive for various remote sensing applications. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Karasik, BS (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, MS 168-314,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Burke, Peter/F-3308-2010 NR 33 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2920-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3465 BP 170 EP 179 DI 10.1117/12.331162 PG 4 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BM32U UT WOS:000078393700031 ER PT B AU Folta, D AF Folta, D BE VanDerHa, JC TI Enhanced formation flying for the new millennium and mission to planet earth programs SO MISSION DESIGN & IMPLEMENTATION OF SATELLITE CONSTELLATIONS SE SPACE TECHNOLOGY PROCEEDINGS LA English DT Proceedings Paper CT International Workshop on Mission Design and Implementation of Satellite Constellations CY NOV, 1997 CL TOULOUSE, FRANCE SP ALCATEL, Ctr natl Etudes Spatiales, Matra Marconi Space AB With scientific objectives for Earth observation programs becoming more ambitious and spacecraft becoming more autonomous, the need for innovative technical approaches on the feasibility of achieving and maintaining formations of spacecraft has come to the forefront. The trend to develop small low-cost spacecraft has led many scientists to recognize the advantage of flying several spacecraft in formation to achieve the correlated instrument measurements formerly possible only by flying many instruments on a single large platform. Yet, formation flying imposes additional complications on orbit maintenance, especially when each spacecraft has its own orbit requirements. However, advances in automation and technology proposed by the Goddard Space Flight Center (GSFC) allow more of the burden in maneuver planning and execution to be placed onboard the spacecraft, mitigating some of the associated operational concerns. The purpose of this paper is to present GSFC's Guidance, Navigation, and Control Center's (GNCC) algorithm for Enhanced Formation Flying of the low earth orbiting spacecraft that are part of the New Millennium Program (NMP). Also addressed are simulation results using this algorithm integrated in an autonomous 'fuzzy logic' control system called AutoCon(TM). This system will be implemented as a close-loop flight code onboard the NMP Earth Orbiter-1 (EO-1) spacecraft and as an open-loop ground support system for the Earth Observing System-AM1 (EOS-AM1). Results of this development can be used to determine the appropriateness of formation flying for a particular case as well as operational impacts. C1 NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Ctr, Greenbelt, MD 20771 USA. RP Folta, D (reprint author), NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Ctr, Greenbelt, MD 20771 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-5210-6 J9 SPACE TECHNOL PROC PY 1998 VL 1 BP 243 EP 254 PG 12 WC Engineering, Aerospace SC Engineering GA BM86K UT WOS:000079961300023 ER PT S AU Randolph, JE Ayon, JA Leschly, K Miyake, RN Tsurutani, BT AF Randolph, JE Ayon, JA Leschly, K Miyake, RN Tsurutani, BT BE Korendyke, CM TI Innovations on the Solar Probe mission SO MISSIONS TO THE SUN II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on the Missions to the Sun II CY JUL 22-23, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE solar probe; active pixel sensor; thermal shield; photovoltaic cells; carbon-carbon AB Both instrument and spacecraft innovations are necessary to develop a mission to four solar radii called the Solar Probe. One of the key observables is the solar wind and its characteristics. To observe the solar wind and the entire plasma distribution function near the sun, two different plasma instruments have been incorporated in the current concept. One instrument can take advantage of velocity aberration to observe the solar wind. This plasma instrument uses an innovative pixelated APS- like plasma detector to view this aberrative solar wind and to allow the sampling of a complete plasma distribution function in 10(-2) sec. Another instrument innovation is the nadir viewing plasma spectrometer which will observe solar wind species in the nadir direction that have high velocities and little or no velocity aberration relative to the spacecraft. A high temperature system of electrostatic mirrors with its own solar shield deflects the high speed species into the plasma detector within the spacecraft umbra. Remote optical instruments are another class of instrument innovations on the Solar Probe. Optical observations of the solar disc will be accomplished with filled aperture tubes which will contribute to the reduction of the 3000 suns solar flux to a few suns at the instrument aperture. The tubes will be fabricated from a carbon-carbon material similar to the primary shield material that can operate at about 2000 K. Spacecraft engineering innovations include the thermal shield/antenna and the high temperature solar arrays. The thermal shield will be fabricated from carbon-carbon material using a process that optimizes its optical properties (alpha/epsilon ratio) which reduces its temperature and its mass loss. Its parabolic shape allows the dual function of shield and antenna at the extreme perihelion temperatures of over 2000 K. The high temperature solar arrays will function near perihelion because of three characteristics: a high temperature photovoltaic material, feathering of the solar arrays to high incidence angles, and the self occultation of the solar arrays near perihelion. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Randolph, JE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2897-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3442 BP 13 EP 21 DI 10.1117/12.330253 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BM19X UT WOS:000078010300002 ER PT S AU Liewer, PC Davis, JM De Jong, EM Gary, GA Klimchuk, JA Reinert, RP AF Liewer, PC Davis, JM De Jong, EM Gary, GA Klimchuk, JA Reinert, RP BE Korendyke, CM TI Report on new mission concept study: Stereo X-ray corona imager mission SO MISSIONS TO THE SUN II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on the Missions to the Sun II CY JUL 22-23, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE corona; space weather; stereoscopy; triangulation; spacecraft; high definition television; 3D visualization AB Studies of the three-dimensional structure and dynamics of the solar corona have been severely limited by the constraint of single viewpoint observations. The Stereo X-Ray Coronal Imager (SXCI) mission will send a single instrument, an X-ray telescope, into deep space expressly to record stereoscopic images of the solar corona. The SXCI spacecraft will be inserted into a similar to 1 AU heliocentric orbit leading Earth by similar to 25 degrees at the end of nine months. The SXCI X-ray telescope forms one element of a stereo pair, the second element being an identical X-ray telescope in Earth orbit placed there as part of the NOAA GOES program. X-ray emission is a powerful diagnostic of the corona and its magnetic fields, and three dimensional information on the coronal magnetic structure would be obtained by combining the data from the two X-ray telescopes. This information can be used to address the major solar physics questions of (1) what causes explosive coronal events such as coronal mass ejections (CMEs), eruptive flares and prominence eruptions and (2) what causes the transient heating of coronal loops. Stereoscopic views of the optically thin corona will resolve some ambiguities inherent in single line-of-sight observations. Triangulation gives 3D solar coordinates of features which can be seen in the simultaneous images from both telescopes. As part of this study, tools were developed for determining the 3D geometry of coronal features using triangulation. Advanced technologies for visualization and analysis of stereo images were tested. Results of mission and spacecraft studies are also reported. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Liewer, PC (reprint author), CALTECH, Jet Prop Lab, MS 169-506, Pasadena, CA 91109 USA. RI Klimchuk, James/D-1041-2012 OI Klimchuk, James/0000-0003-2255-0305 NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2897-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3442 BP 53 EP 64 DI 10.1117/12.330264 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BM19X UT WOS:000078010300006 ER PT S AU Goldstein, BE Buffington, A Cummings, AC Fisher, R Jackson, BV Liewer, PC Mewaldt, RA Neugebauer, M AF Goldstein, BE Buffington, A Cummings, AC Fisher, R Jackson, BV Liewer, PC Mewaldt, RA Neugebauer, M BE Korendyke, CM TI A Solar Polar Sail Mission: Report of a study to put a scientific spacecraft in a circular polar orbit about the sun SO MISSIONS TO THE SUN II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on the Missions to the Sun II CY JUL 22-23, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE solar sail; sail; solar wind; spacecraft; solar polar orbit; corona AB The Solar Polar Sail Mission uses solar-sail propulsion to place a spacecraft in a circular orbit 0.48 AU from the Sun with an inclination of 90 degrees. The spacecraft's orbit around the Sun (4 months period) is in 3:1 resonance with Earth phased such that the Earth-Sun-spacecraft angle ranges from 30 degrees to 150 degrees. The polar view will further our understanding of: (1) the global structure and evolution of the corona, (2) the initiation, evolution, and propagation of coronal mass ejections; (3) the acceleration of the solar wind; (4) the interactions of rotation, magnetic fields, and convection within the Sun; (5) the acceleration and propagation of energetic particles; and (6) the rate of angular momentum loss by the Sun. Candidate imaging instruments are a coronagraph, an all-sky imager for following mass ejections and interaction regions from the Sun to 1 AU, and a disk imager. A lightweight package of fields and particle instruments (plasma spectrometer, magnetometer, energetic particle telescopes) is included. A mission using a 158 m square sail with an effective areal density of 6 g/m(2) would cost approximately $250-300M(FY97) for all mission phases, including the launch vehicle. This mission depends on the successful development and demonstration of solar-sail propulsion. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Goldstein, BE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 6 Z9 6 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2897-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3442 BP 65 EP 76 DI 10.1117/12.330265 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BM19X UT WOS:000078010300007 ER PT S AU Desai, UD Orwig, L Piquet, L Gaither, CC AF Desai, UD Orwig, L Piquet, L Gaither, CC BE Korendyke, CM TI X-ray telescope for small satellites SO MISSIONS TO THE SUN II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on the Missions to the Sun II CY JUL 22-23, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE imaging; X-ray; Fresnel; solar AB The study of high energy, transient astrophysical phenomena (solar flares, pulsars, X-ray bursters, gamma ray bursts) requires new instrumentation capable of simultaneously performing high spatial, temporal and spectral observations. Currently, there are no elements such as lenses or mirrors capable of reflecting or refracting X- and gamma rays. Shadow-casting techniques must be employed to image such sources. These techniques rely on the total absorption of X- and gamma rays to indirectly give images of the sources. We describe here a design for an X-ray telescope based on dual Fresnel Zone Plate (FZP) coders suitable for small satellites. Most shadow-casters require an image plane detector with a spatial resolution comparable to the smallest features cut into the coder for the best angular resolution. The image plane detector for a telescope based on dual FZPs does not have such a requirement because the coders measure almost the exact spatial Fourier transform of the source distribution. We present here the results of laboratory tests and simulations that demonstrate the feasibility of constructing such a telescope and its ability to produce images of X-ray sources. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Desai, UD (reprint author), NASA, Goddard Space Flight Ctr, Code 682-2, Greenbelt, MD 20771 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2897-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3442 BP 94 EP 104 DI 10.1117/12.330247 PG 11 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BM19X UT WOS:000078010300010 ER PT S AU Ruzmaikin, A Moynihan, PI Vaughan, AH Cacciani, A AF Ruzmaikin, A Moynihan, PI Vaughan, AH Cacciani, A BE Korendyke, CM TI Compact Doppler magnetograph SO MISSIONS TO THE SUN II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on the Missions to the Sun II CY JUL 22-23, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE Doppler; magnetic field; spacecraft imaging; solar instrumentation AB We designed a low-cost flight instrument that images the full solar disk through two narrowband filters at the red and blue "wings" of the solar potassium absorption line. The images are produced on a 1024x1024 charge-coupled device with a resolution of 2 arcsec per pixel. Four filtergrams taken in a very short time at both wings in the left and right states of circular polarization are used to yield a Dopplergram and a magnetogram simultaneously. The noise-equivalent velocity associated with each pixel is less than 3 m/s. The measured signal is linearly proportional to the velocity in the range +/- 4000 m/s. The range of magnetic fields is from 3 to 3000 Gauss. The optical system of the instrument is simple and easily aligned. With a pixel size of 12 mu m, the effective focal length is 126 cm. A Raleigh resolution limit of 4 arcsec is achieved with a 5-cm entrance aperture, providing an f/25 focal ratio. The foreoptic is a two-component telephoto lens serving to limit the overall optical length to 89 cm or less. The mass of the instrument is 14 kg. The power required is less than 30 Watts. The Compact Doppler Magnetograph can be used in space missions with severe mass and power requirements. It can also be effectively used for ground-based observations: Large telescope, dome or other observatory facilities are not required. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ruzmaikin, A (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 SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2897-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3442 BP 115 EP 124 DI 10.1117/12.330262 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BM19X UT WOS:000078010300012 ER PT S AU Laubach, SL Burdick, JW AF Laubach, SL Burdick, JW BE Choset, HM Gage, DW Kachroo, P Kourjanski, MA deVries, MJ TI A practical autonomous path-planner for turn-of-the-century planetary microrovers SO MOBILE ROBOTS XIII AND INTELLIGENT TRANSPORTATION SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Mobile Robots XIII and Intelligent Transportation Systems CY NOV 03-05, 1998 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers, Soc Mfg Engineers DE navigation; sensor based planning; Mars rover; gaze control AB With the success of Mars Pathfinder's Sojourner rover, a new era of planetary exploration has opened, with demand for highly capable mobile robots. These robots must be able to traverse long distances over rough, unknown terrain autonomously, under severe resource constraints. Based on the authors' firsthand experience with the Mars Pathfinder mission, this paper reviews issues which are critical for successful autonomous navigation of planetary revers. No currently proposed methodology addresses all of these issues. We next report on the "Wedgebug" algorithm, which is applicable to planetary rover navigation in SE(2). The Wedgebug algorithm is complete, correct, requires minimal memory for storage of its world model, and uses only on-board sensors, which are guided by the algorithm to efficiently sense only the data needed for motion planning. The implementation of a version of Wedgebug on the Rocky7 Mars Rover prototype at the Jet Propulsion Laboratory (JPL) is described, and experimental results from operation in simulated martian terrain are presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Laubach, SL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2986-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3525 BP 182 EP 191 PG 10 WC Automation & Control Systems; Engineering, Manufacturing; Optics; Transportation SC Automation & Control Systems; Engineering; Optics; Transportation GA BM42S UT WOS:000078690700018 ER PT B AU Ghosn, LJ Raj, SV AF Ghosn, LJ Raj, SV BE Taleff, EM Mahidhara, RK TI Modeling the mechanical reponse of a Nb-1Zr/218W composite system SO MODELING THE MECHANICAL RESPONSE OF STRUCTURAL MATERIALS LA English DT Proceedings Paper CT Symposium on Modeling the Mechanical Response of Structural Materials at the 127th Annual Meeting of the Minerals-Metals-and-Materials-Society CY FEB 15-19, 1998 CL SAN ANTONIO, TX SP Minerals Met & Mat Soc, Struct Mat Comm AB Finite element analyses were performed to model the mechanical behavior of various fiber volume fractions of a Nb-1Zr/218W composite system. Due to the lack of reliable experimental data on the 218-W fibers at the temperatures and loading rates of interest, the constituent mechanical properties were back calculated from the composite response for one fiber volume fraction. For verification, the same calibrated properties were applied to composites with other fiber volume fractions. Good agreement was observed between the predicted and measured composite stress/strain behaviors at various temperatures and loading rates. The present analyses also provided insight into the build-up of residual stresses in the matrix and fibers after cool down to room temperature from the processing temperatures, as well as the subsequent stress state resulting from heat-up to the testing temperatures. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Ghosn, LJ (reprint author), NASA, Lewis Res Ctr, 21000 Brookpark Rd, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-392-9 PY 1998 BP 45 EP 52 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA BK53N UT WOS:000072466900005 ER PT S AU Anantram, MP Han, J Govindan, TR AF Anantram, MP Han, J Govindan, TR BE Aviram, A Ratner, M TI Transport in (10,10) carbon nanotubes with defects SO MOLECULAR ELECTRONICS: SCIENCE AND TECHNOLOGY SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Molecular Electronics - Science and Technology CY DEC 14-18, 1997 CL HUMACAO, PUERTO RICO SP United Engn Trustees, Engn Fdn, New York Acad Sci, Colegio Ingen Agrimensores Puerto Rico, Defense Adv Res Project Agcy, Natl Sci Fdn, USN, Off Naval Res AB In this paper, we numerically calculate the conductance characteristics of a uniform (10,10) carbon nanotube in the presence of an applied bias. It is shown that for long tubes, the conduction mechanism involves only the four nondegenerate sub-bands when the applied bias drops slowly across the tube. The focus of our work is to calculate the transmission coefficient and low bias conductance of carbon nanotubes with defects. Our calculations show that(1) a weak uniform disorder in the tube does not cause a significant change in the zero bias conductance and (2) substitutional defects which are strong scatterers, can cause a gap in the transmission coefficient versus energy at the middle of the band resulting in a significant change in the low bias conductance. C1 NASA, Ames Res Ctr, Moffett Field, CA 94045 USA. Appl Res Lab, State Coll, PA 16804 USA. RP Anantram, MP (reprint author), NASA, Ames Res Ctr, Mail Stop T27-A, Moffett Field, CA 94045 USA. EM anant@nas.nasa.gov NR 14 TC 3 Z9 3 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-156-1 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1998 VL 852 BP 169 EP 177 DI 10.1111/j.1749-6632.1998.tb09870.x PG 9 WC Engineering, Biomedical; Engineering, Electrical & Electronic; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA BL66Q UT WOS:000076245100010 ER PT S AU Srivastava, D Saini, S Menon, M AF Srivastava, D Saini, S Menon, M BE Aviram, A Ratner, M TI Carbon nanotubes: Molecular electronic components SO MOLECULAR ELECTRONICS: SCIENCE AND TECHNOLOGY SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Molecular Electronics - Science and Technology CY DEC 14-18, 1997 CL HUMACAO, PUERTO RICO SP United Engn Trustees, Engn Fdn, New York Acad Sci, Colegio Ingen Agrimensores Puerto Rico, Defense Adv Res Project Agcy, Natl Sci Fdn, USN, Off Naval Res ID TUBULES; MICROTUBULES; FULLERENES; CLUSTERS; DEVICES; C-60 AB The carbon nanotube junctions have recently emerged as excellent candidates for use as the building blocks in the formation of nanoscale molecular electronic networks. While the simple joint of two dissimilar tubes can be generated by the introduction of a pair of heptagon-pentagon defects in an otherwise perfect hexagonal graphene sheet, more complex joints require other mechanisms. In this work we explore structural characteristics of complex 3-point junctions of carbon nanotubes using a generalized tight-binding molecular dynamics scheme. The study of pi-electron local densities of states (LDOS) of these junctions reveal many interesting features, most prominent among them being the defect-induced states in the gap. C1 NASA, Ames Res Ctr, MRJ, Moffett Field, CA 94035 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. RP Srivastava, D (reprint author), NASA, Ames Res Ctr, MRJ, Mail Stop T27-A1, Moffett Field, CA 94035 USA. NR 19 TC 10 Z9 10 U1 1 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-156-1 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1998 VL 852 BP 178 EP 187 DI 10.1111/j.1749-6632.1998.tb09871.x PG 10 WC Engineering, Biomedical; Engineering, Electrical & Electronic; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA BL66Q UT WOS:000076245100011 ER PT B AU Sobieszczanski-Sobieski, J AF Sobieszczanski-Sobieski, J GP ROYAL AERONAUT SOC ROYAL AERONAUT SOC TI Multidisciplinary design optimization (MDO) methods: Their synergy with computer technology in design process SO MULTIDISCIPLINARY DESIGN AND OPTIMISATION, PROCEEDINGS LA English DT Proceedings Paper CT Conference on Multidisciplinary Design and Optimisation CY OCT 26-27, 1998 CL LONDON, ENGLAND SP Royal Aeronaut Soc ID SENSITIVITY; DERIVATIVES; COMPLEX AB The paper identifies speed, agility, human interface, generation of sensitivity information, task decomposition, and data transmission (including storage) as important attributes for a computer environment to have in order to support engineering design effectively. It is argued that when examined in terms of these attributes the presently available environment can be shown to be inadequate. A radical improvement is needed, and it may be achieved by combining new methods that have recently emerged from multidisciplinary design optimization (MDO) with massively parallel processing computer technology. The caveat is that, for successful use of that technology in engineering computing, new paradigms for computing will have to be developed-specifically, innovative algorithms that are intrinsically parallel so that their performance scales up Linearly with the number of processors. It may be speculated that the idea of simulating a complex behavior by interaction of a large number of very simple models may be an inspiration for the above algorithms; the cellular automata are an example. Because of the long lead time needed to develop and mature new paradigms, development should begin now, even though the widespread availability of massively parallel processing is still a few years away. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Sobieszczanski-Sobieski, J (reprint author), NASA, Langley Res Ctr, MS 139, Hampton, VA 23681 USA. NR 35 TC 0 Z9 0 U1 0 U2 0 PU ROYAL AERONAUTICAL SOCIETY PI LONDON PA 4 HAMILTON PLACE, LONDON W1V 0BQ, ENGLAND BN 1-85768-074-X PY 1998 BP K1 EP K14 PG 14 WC Engineering, Aerospace SC Engineering GA BN75R UT WOS:000082822500011 ER PT S AU Domingo, V Sanchez, L Appourchaux, T AF Domingo, V Sanchez, L Appourchaux, T BE Deubner, FL ChristensenDalsgaard, J Kurtz, D TI Observations of the latitudinal variation of the solar radiance of non active regions of the Sun SO NEW EYES TO SEE INSIDE THE SUN AND STARS: PUSHING THE LIMITS OF HELIO- AND ASTEROSEISMOLOGY WITH NEW OBSERVATIONS FROM THE GROUND AND FROM SPACE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 185th Symposium of the International-Astronomical-Union on New Eyes to See Inside the Sun and Stars CY AUG 18-22, 1997 CL KYOTO, JAPAN SP Int Astron Union ID VIRGO C1 NASA, Goddard Space Flight Ctr, ESA, Greenbelt, MD 20771 USA. European Space Agcy, Estec, Dept Space Sci, NL-2200 AG Noordwijk, Netherlands. RP Domingo, V (reprint author), NASA, Goddard Space Flight Ctr, ESA, Code 682, Greenbelt, MD 20771 USA. NR 4 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 0-7923-5075-8 J9 IAU SYMP PY 1998 IS 185 BP 111 EP 112 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM51L UT WOS:000078932400021 ER PT S AU Giles, PM Duvall, TL AF Giles, PM Duvall, TL BE Deubner, FL ChristensenDalsgaard, J Kurtz, D TI Solar rotation and large-scale flows measured by time-distance helioseismology from MDI SO NEW EYES TO SEE INSIDE THE SUN AND STARS: PUSHING THE LIMITS OF HELIO- AND ASTEROSEISMOLOGY WITH NEW OBSERVATIONS FROM THE GROUND AND FROM SPACE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 185th Symposium of the International-Astronomical-Union on New Eyes to See Inside the Sun and Stars CY AUG 18-22, 1997 CL KYOTO, JAPAN SP Int Astron Union ID MOUNT-WILSON; MERIDIONAL FLOW AB The technique of time-distance helioseismology provides a new tool for examining large-scale flows beneath the sun's surface. We have used this technique to study the meridional flow and have found that the poleward flow observed at the surface appears to persist to a depth of at least 26,000 km. We have also examined the differential rotation in these uppermost layers, and find a slight asymmetry between the northern and southern hemispheres. C1 Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Giles, PM (reprint author), Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. RI Duvall, Thomas/C-9998-2012 NR 9 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 0-7923-5075-8 J9 IAU SYMP PY 1998 IS 185 BP 149 EP 152 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM51L UT WOS:000078932400031 ER PT S AU Fontaine, G Charpinet, S Brassard, P Chayer, P Rogers, FJ Iglesias, CA Dorman, B AF Fontaine, G Charpinet, S Brassard, P Chayer, P Rogers, FJ Iglesias, CA Dorman, B BE Deubner, FL ChristensenDalsgaard, J Kurtz, D TI EC14026 stars: Theoretical considerations SO NEW EYES TO SEE INSIDE THE SUN AND STARS: PUSHING THE LIMITS OF HELIO- AND ASTEROSEISMOLOGY WITH NEW OBSERVATIONS FROM THE GROUND AND FROM SPACE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 185th Symposium of the International-Astronomical-Union on New Eyes to See Inside the Sun and Stars CY AUG 18-22, 1997 CL KYOTO, JAPAN SP Int Astron Union ID SUBDWARF B-STARS; HOT C1 Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. Univ Calif Berkeley, Ctr Euv Astrophys, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Fontaine, G (reprint author), Univ Montreal, Dept Phys, CP 6128, Montreal, PQ H3C 3J7, Canada. NR 12 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-5075-8 J9 IAU SYMP PY 1998 IS 185 BP 367 EP 374 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM51L UT WOS:000078932400079 ER PT S AU Straus, T Deubner, FL Fleck, B Marmolino, C Severino, C Tarbell, T AF Straus, T Deubner, FL Fleck, B Marmolino, C Severino, C Tarbell, T BE Deubner, FL ChristensenDalsgaard, J Kurtz, D TI Phase spectra seen from space SO NEW EYES TO SEE INSIDE THE SUN AND STARS: PUSHING THE LIMITS OF HELIO- AND ASTEROSEISMOLOGY WITH NEW OBSERVATIONS FROM THE GROUND AND FROM SPACE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 185th Symposium of the International-Astronomical-Union on New Eyes to See Inside the Sun and Stars CY AUG 18-22, 1997 CL KYOTO, JAPAN SP Int Astron Union ID REFLECTION; DYNAMICS C1 Osservatorio Astron Capodimonte, I-80131 Naples, Italy. Univ Wurzburg, Inst Astron & Astrophys, D-8700 Wurzburg, Germany. NASA, Goddard Space Flight Ctr, ESA, Dept Space Sci, Greenbelt, MD 20771 USA. Univ Naples Federico II, Naples, Italy. Osservatorio Astron Capodimonte, I-80131 Naples, Italy. Lockheed Martin Adv Technol Ctr, Palo Alto, CA USA. RP Straus, T (reprint author), Osservatorio Astron Capodimonte, I-80131 Naples, Italy. RI Fleck, Bernhard/C-9520-2012; Marmolino, Ciro/H-3394-2012 OI Marmolino, Ciro/0000-0003-1367-332X NR 5 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 0-7923-5075-8 J9 IAU SYMP PY 1998 IS 185 BP 455 EP 456 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM51L UT WOS:000078932400101 ER PT S AU Beichman, CA AF Beichman, CA BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI Infrared surveys: A golden age of exploration SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV ID GALAXY; COBE; BAR C1 CALTECH, Jet Prop Lab, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. RP Beichman, CA (reprint author), CALTECH, Jet Prop Lab, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. NR 19 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 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 27 EP 40 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600004 ER PT S AU Gehrels, N AF Gehrels, N BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI Gamma ray sky surveys SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MD SP Int Astron Union HO JOHNS HOPKINS UNIV ID COMPTEL OBSERVATIONS; COS-B; EMISSION; CATALOG C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gehrels, N (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012 NR 20 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 69 EP 77 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600008 ER PT S AU Leisawitz, D Digel, SW Geitz, S AF Leisawitz, D Digel, SW Geitz, S BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI Multiwavelength Milky Way: An educational poster SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV AB The Astrophysics Data Facility at NASA Goddard Space Flight Center supports the processing, management, and dissemination of data obtained by past, current, and future NASA and international astrophysics missions, and promotes the effective use of those data by the astrophysics community, educators, and the public. Our Multiwavelength Milky Way poster was printed for broad distribution. It depicts the Galaxy at radio, infrared, optical, X-ray, and gamma-ray wavelengths. In particular, tl-ie poster contains images of the Galactic 21-cm and CO (J = 1 --> 0) line emission, and IRAS 12, 60, and 100 mu m, COBE/DIRBE 1.25, 2.2, and 3.5 mu m, Digitized Sky Survey optical wavelength, ROSAT/PSPC 0.25, 0.75, and 1.5 keV X-ray, and CGRO/EGRET E > 100 MeV gamma ray broadband emission. All of the data sets are publicly available. Captions describe the Milky Way and what can be learned about the Galaxy from measurements made in each segment of the electromagnetic spectrum. The poster is intended to be an educational tool, one that will stimulate heightened awareness by laypersons of NASA's contribution to modern astronomy. Through an interface available on the World Wide Web at http://adf.gsfc.nasa.gov/adf/adf.html one may view the images that appear on the poster, read the poster captions, and locate the archived data and references. C1 NASA, Goddard Space Flight Ctr, Astrophys Data Facil, Greenbelt, MD 20771 USA. RP Leisawitz, D (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Data Facil, Greenbelt, MD 20771 USA. NR 0 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 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 237 EP 237 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600054 ER PT S AU Gardner, JP Sharples, RM Frenk, CS Carrasco, BE AF Gardner, JP Sharples, RM Frenk, CS Carrasco, BE BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI The K-band luminosity function of galaxies SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV ID REDSHIFT SURVEY C1 NASA, GSFC, Greenbelt, MD USA. RP Gardner, JP (reprint author), Univ Durham, Dept Phys, S Rd, Durham DH1 3HP, England. RI Sharples, Ray/N-7309-2013 OI Sharples, Ray/0000-0003-3449-8583 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 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 278 EP 280 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600063 ER PT S AU Horner, D Scharf, CA Jones, LR Ebeling, H Perlman, E Malkan, M Wegner, G AF Horner, D Scharf, CA Jones, LR Ebeling, H Perlman, E Malkan, M Wegner, G BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI The WARPS X-ray Survey of galaxies, groups, and clusters SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Horner, D (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 308 EP 309 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600073 ER PT S AU Ogasaka, Y Ueda, Y Ishisaki, Y Kii, T Takahashi, T Makishima, K Inoue, H Ohta, K Yamada, T Miyaji, T Hasinger, G AF Ogasaka, Y Ueda, Y Ishisaki, Y Kii, T Takahashi, T Makishima, K Inoue, H Ohta, K Yamada, T Miyaji, T Hasinger, G BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI Results from ASCA sky surveys SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV ID N-LOG S C1 NASA, Goddard Space Flight Ctr, JEPS, Greenbelt, MD 20771 USA. RP Ogasaka, Y (reprint author), NASA, Goddard Space Flight Ctr, JEPS, Greenbelt, MD 20771 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 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 312 EP 313 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600075 ER PT S AU Williger, G Smette, A Hazard, C Baldwin, J McMahon, R AF Williger, G Smette, A Hazard, C Baldwin, J McMahon, R BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI Large scale structure in the Ly alpha forest SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV C1 MPIA, Heidelberg, Germany. RP Williger, G (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 3 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 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 329 EP 331 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600077 ER PT S AU McGlynn, T Scollick, K White, N AF McGlynn, T Scollick, K White, N BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI SkyView: The multi-wavelength sky on the Internet SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP McGlynn, T (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 0 TC 3 Z9 3 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 465 EP 466 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600117 ER PT S AU Roman, NG AF Roman, NG BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI Surveys in the ADC archive SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV C1 Goddard Space Flight Ctr, ADC, HughesSTX, Greenbelt, MD 20771 USA. RP Roman, NG (reprint author), Goddard Space Flight Ctr, ADC, HughesSTX, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 478 EP 479 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600122 ER PT S AU White, NE AF White, NE BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI Global network access and publication of survey data SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV C1 GSFC, High Energy Astrophys Lab, High Energy Astrophys Sci Arch Res Ctr, Greenbelt, MD 20771 USA. RP White, NE (reprint author), GSFC, High Energy Astrophys Lab, High Energy Astrophys Sci Arch Res Ctr, Greenbelt, MD 20771 USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 0 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 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 480 EP 486 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600123 ER PT J AU Stibbe, DT Tennyson, J AF Stibbe, Darian T. Tennyson, Jonathan TI Near-threshold electron impact dissociation of H-2 within the adiabatic nuclei approximation SO NEW JOURNAL OF PHYSICS LA English DT Article ID MOLECULAR-HYDROGEN; CROSS-SECTIONS; B3-SIGMA-U+ STATE; ROTATIONAL-EXCITATION; VARIATIONAL METHOD; SCATTERING; RESONANCES; COLLISIONS; PLASMA; H2 AB At low energies, the major pathway for the electron-impact dissociation of H-2 (e + H-2 -> H(1s) + H(1s)+ e) is through excitation to the b 3 Sigma(+)(u) dissociative state. We present ab initio calculations of the rate of dissociation as a function of initial vibrational level. The calculations employ an extension to the adiabatic nuclei approximation, balancing the energy between the electrons and the nuclei, for excitation to a dissociation continuum. We find that near-threshold rates show so strong a dependence on the initial H-2 vibrational level that the common practice of approximating the total dissociation rate to the upsilon = 0 rate is invalid in many situations. C1 [Stibbe, Darian T.; Tennyson, Jonathan] Univ London Univ Coll, Dept Phys & Astron, London WC1E 6BT, England. [Stibbe, Darian T.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Stibbe, DT (reprint author), Univ London Univ Coll, Dept Phys & Astron, Gower St, London WC1E 6BT, England. RI Tennyson, Jonathan/I-2222-2012 OI Tennyson, Jonathan/0000-0002-4994-5238 FU UK EPSRC FX We thank Nick Achilleos, Alex Dalgarno, Nigel Mason, Ismanuel Rabadan and Pete Storey for useful discussions, and the UK EPSRC for support. This work was completed while DTS held an NRC/NASA Ames Research Center Research Associateship. NR 41 TC 45 Z9 45 U1 1 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1367-2630 J9 NEW J PHYS JI New J. Phys. PY 1998 VL 1 AR 2 DI 10.1088/1367-2630/1/1/002 PG 9 WC Physics, Multidisciplinary SC Physics GA V25DT UT WOS:000208459400002 ER PT B AU Tandberg-Hanssen, E AF Tandberg-Hanssen, E BE Webb, D Rust, D Schmieder, B TI The history of solar prominence research: Historical introduction to IAU colloquium no. 167 "New perspectives on solar prominences" SO NEW PERSPECTIVES ON SOLAR PROMINENCES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT IAU Colloquium 167 on New Perspectives on Solar Prominences CY APR 28-MAY 03, 1997 CL CTR PAUL LANGEVIN, AUSSOIS, FRANCE SP Intl Astron Union, Sci Comm Solar Terr Phys, European Off Aerosp Res & Dev, CNRS, Observ Paris, CEA, Ctr Natl Etud Spat HO CTR PAUL LANGEVIN AB We trace the history of observational solar prominence research from the early period when total solar eclipses provided the only means of observation, via the introduction of photography and spectroscopy in the 1860's, to the present epoch when application of the Zeeman and the Hanle effects makes possible determination of the all-important magnetic fields in prominences. Dividing prominence models into two classes, those that treat the support of the prominence against gravity and those concerned with the physical conditions in the prominence plasma itself, we describe the progress made in both classes of models since the 1950's, when the first models were proposed. Finally, we comment on the necessity of combining aspects of the two classes of prominence models into a comprehensive picture that can account for the global nature of prominence support and stability, and where the adjacent coronal structures play an important role. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Tandberg-Hanssen, E (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 10 Z9 10 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-70-8 J9 ASTR SOC P PY 1998 VL 150 BP 11 EP 19 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL75E UT WOS:000076565100002 ER PT B AU Ofman, L Mouradian, Z Kucera, TA Poland, AI AF Ofman, L Mouradian, Z Kucera, TA Poland, AI BE Webb, D Rust, D Schmieder, B TI Observation of a prominence heating and the heating mechanism SO NEW PERSPECTIVES ON SOLAR PROMINENCES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT IAU Colloquium 167 on New Perspectives on Solar Prominences CY APR 28-MAY 03, 1997 CL CTR PAUL LANGEVIN, AUSSOIS, FRANCE SP Intl Astron Union, Sci Comm Solar Terr Phys, European Off Aerosp Res & Dev, CNRS, Observ Paris, CEA, Ctr Natl Etud Spat HO CTR PAUL LANGEVIN AB An arch-shaped prominence was observed with SUMER-SOHO spectrometer on March 31-April 1, 1996. The observations were performed at three wavelengths in the Lyman continuum. Ten successive images were obtained at 41 minute time intervals. Based on the computed models of Gouttebroze-Heinzel-Vial we have determined the temperature distribution of the prominence using the intensity ratio of 876 Angstrom and 907 Angstrom. The observed time sequence shows that the prominence disappears by heating, i.e., ionization of hydrogen: a thermal DB. We model the heat input with the linearized MHD equations using a prescribed initial density and a broad-band spectrum of Alfven waves and find a good qualitative agreement with observations. In the model the prominence is heated by the resonant absorption of Alfven waves with frequencies that match the resonant condition for a particular flux tube structure that is determined by the magnetic field topology and density. C1 NASA, Goddard Space Flight Ctr, Hughes STX, Greenbelt, MD 20771 USA. RP Ofman, L (reprint author), NASA, Goddard Space Flight Ctr, Hughes STX, Code 682, Greenbelt, MD 20771 USA. RI Kucera, Therese/C-9558-2012 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 USA BN 1-886733-70-8 J9 ASTR SOC P PY 1998 VL 150 BP 159 EP 162 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL75E UT WOS:000076565100032 ER PT B AU Martens, PCH AF Martens, PCH BE Webb, D Rust, D Schmieder, B TI MHD and plasma interpretation of a prominence eruption observed by SOHO SO NEW PERSPECTIVES ON SOLAR PROMINENCES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT IAU Colloquium 167 on New Perspectives on Solar Prominences CY APR 28-MAY 03, 1997 CL CTR PAUL LANGEVIN, AUSSOIS, FRANCE SP Intl Astron Union, Sci Comm Solar Terr Phys, European Off Aerosp Res & Dev, CNRS, Observ Paris, CEA, Ctr Natl Etud Spat HO CTR PAUL LANGEVIN AB Data on the May 1, 1996 prominence eruption, jointly observed by CDS, SUMER, and EIT, aboard SOHO, Yohkoh-SXT, and Kitt Peak and Meudon observatories are analyzed to obtain information on the plasma temperature, density, and velocities, as well as the magnetic field topology and strength. It is found that the 'standard' model of an erupting helical flux tube probably applies, although questions arise on the MHD stability of the prominence flux tube. The prominence is observed to remain relatively cool during its eruption (less than or equal to 5 x 10(5) K), while the density and velocity vary considerably on scales down to the limit of resolution. It is found that the high density, high velocity plasma blobs can be contained by the relatively weak magnetic field, as is indeed observed. C1 NASA, Goddard Space Flight Ctr, SOHO Expt Operat fac, ESA Space Sci Dept, Greenbelt, MD 20771 USA. RP Martens, PCH (reprint author), NASA, Goddard Space Flight Ctr, SOHO Expt Operat fac, ESA Space Sci Dept, Code 682-3, Greenbelt, MD 20771 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-70-8 J9 ASTR SOC P PY 1998 VL 150 BP 294 EP 301 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL75E UT WOS:000076565100059 ER PT B AU Kucera, TA Poland, AI Wiik, JE Schmieder, B Simnett, G AF Kucera, TA Poland, AI Wiik, JE Schmieder, B Simnett, G BE Webb, D Rust, D Schmieder, B TI Helical structure in an eruptive prominence related to a CME (SUMER, CDS, LASCO) SO NEW PERSPECTIVES ON SOLAR PROMINENCES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT IAU Colloquium 167 on New Perspectives on Solar Prominences CY APR 28-MAY 03, 1997 CL CTR PAUL LANGEVIN, AUSSOIS, FRANCE SP Intl Astron Union, Sci Comm Solar Terr Phys, European Off Aerosp Res & Dev, CNRS, Observ Paris, CEA, Ctr Natl Etud Spat HO CTR PAUL LANGEVIN AB SOHO (SUMER/CDS) observed an eruptive prominence on May 1, 1996, associated with a CME observed by LASCO. We investigate the physical conditions of this prominence in order to quantify velocity, temperature, and density. SUMER spectra in Si IV and O IV lines are used to obtain Doppler-shift images of the prominence. The prominence shows large-scale red and blueshifted regions, revealing a large helical structure with a global twist. In addition, fine structure analysis shows multiple components in the line profile, suggesting integration of many threads along the line-of-sight with a large dispersion of velocities (+/- 50 km s(-1)). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kucera, TA (reprint author), NASA, Goddard Space Flight Ctr, Code 682, Greenbelt, MD 20771 USA. RI Kucera, Therese/C-9558-2012 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 USA BN 1-886733-70-8 J9 ASTR SOC P PY 1998 VL 150 BP 318 EP 321 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL75E UT WOS:000076565100063 ER PT B AU Liu, WT Tang, WQ Xie, XS AF Liu, WT Tang, WQ Xie, XS GP AMER METEOROL SOC AMER METEOROL SOC TI Asian monsoons observed by the scatterometers and complementary spacebased sensors SO NINTH CONFERENCE ON INTERACTION OF THE SEA AND ATMOSPHERE LA English DT Proceedings Paper CT 9th Conference on Interaction of the Sea and Atmosphere at the 78th American-Meteorogical-Society Annual Meeting CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Liu, WT (reprint author), CALTECH, Jet Prop Lab, MS 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 36 EP 39 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80E UT WOS:000076779300009 ER PT B AU Yang, S Lau, KM Schopf, PS AF Yang, S Lau, KM Schopf, PS GP AMER METEOROL SOC AMER METEOROL SOC TI Influences of precipitation on tropical ocean structure SO NINTH CONFERENCE ON INTERACTION OF THE SEA AND ATMOSPHERE LA English DT Proceedings Paper CT 9th Conference on Interaction of the Sea and Atmosphere at the 78th American-Meteorogical-Society Annual Meeting CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Climate & Radiat Branch, Greenbelt, MD 20771 USA. RP Yang, S (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Climate & Radiat Branch, Greenbelt, MD 20771 USA. RI Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 149 EP 154 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80E UT WOS:000076779300039 ER PT B AU Nikora, AP Munson, JC AF Nikora, AP Munson, JC GP IEEE IEEE TI Determining fault insertion rates for evolving software systems SO NINTH INTERNATIONAL SYMPOSIUM ON SOFTWARE RELIABILITY ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT 9th International Symposium on Software Reliability Engineering (ISSRE 98) CY NOV 04-07, 1998 CL PADERBORN, GERMANY SP IEEE Comp Soc Tech Council Software Engn, IEEE Reliabil Soc, DVE, Siemens Nixdorf, IBM, Daimler Benz, Nortel Network, DGQ, DFG, Univ Gesamthochschule Paderborn C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Allen.P.Nikora@jpl.nasa.gov; jmunson@cs.uidaho.edu NR 20 TC 4 Z9 4 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8991-9 PY 1998 BP 306 EP 315 DI 10.1109/ISSRE.1998.730895 PG 10 WC Computer Science, Software Engineering SC Computer Science GA BM31F UT WOS:000078348800037 ER PT B AU Easterbrook, S Callahan, J Wiels, V AF Easterbrook, S Callahan, J Wiels, V GP IEEE TI V & V through inconsistency tracking and analysis SO NINTH INTERNATIONAL WORKSHOP ON SOFTWARE SPECIFICATION AND DESIGN, PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Software Specification and Design CY APR 16-18, 1998 CL ISE SHIMA, JAPAN SP IEEE, Comp Soc, Tech Council Software Engn, ACM SIGSOFT, IPSJ SIGSE, JSST AB In this paper we describe a research agenda for a study into the use of inconsistency analysis as a tool for software V&V, and in particular; the use of category theory as a basis for modeling consistency relationships between the various artifacts of software development, including specifications, design, test cases, etc. Our expectation is that inconsistency analysis is fundamental to much of the work of V&V, and that a systematic approach will have impacts across a wide range of V&V tasks. Two goals are described: an account of the contribution of inconsistency analysis to various V&V analyses, and the development of a formal framework for inconsistency analysis. Our approach to the development of the latter is through the refinement of the viewpoint framework using the language of category theory We discuss the relationship between specification morphisms, as conventionally conceived in work on composition of specifications, and inter-viewpoint consistency relationships. We conclude that inconsistency analysis has the potential to address the 'air gaps' between methods used during the various phases of the software lifecycle. C1 NASA, WVU Software Res Lab, Fairmont, WV 26554 USA. RP Easterbrook, S (reprint author), NASA, WVU Software Res Lab, 100 Univ Dr, Fairmont, WV 26554 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8439-9 PY 1998 BP 43 EP 49 DI 10.1109/IWSSD.1998.667918 PG 7 WC Computer Science, Software Engineering SC Computer Science GA BK85K UT WOS:000073665800006 ER PT B AU Townsend, WF AF Townsend, WF GP AMER METEOROL SOC AMER METEOROL SOC TI Status, progress and outlook of national aeronautics and space administration's (NASA) global change related programs SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 NASA Headquarters, Washington, DC 20546 USA. RP Townsend, WF (reprint author), NASA Headquarters, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 5 EP 6 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200002 ER PT B AU Hu, H Liu, WT AF Hu, H Liu, WT GP AMER METEOROL SOC AMER METEOROL SOC TI Extratropical influence of upper tropospheric water vapor on greenhouse warming SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. RP Hu, H (reprint author), CALTECH, Jet Prop Lab, Div Earth & Space Sci, 4800 Oak Grove Dr,MS 300-323, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 27 EP 30 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200009 ER PT B AU Jedlovec, GJ Chang, FC Suggs, RJ Guillory, AR AF Jedlovec, GJ Chang, FC Suggs, RJ Guillory, AR GP AMER METEOROL SOC AMER METEOROL SOC TI Variations in atmospheric water vapor as seen in satellite data and model reanalysis fields SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 NASA, Marshall Space Flight Ctr, Global Hydrol & Climate Ctr, Huntsville, AL 35806 USA. RP Jedlovec, GJ (reprint author), NASA, Marshall Space Flight Ctr, Global Hydrol & Climate Ctr, 977 Explorer Blvd, Huntsville, AL 35806 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 31 EP 35 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200010 ER PT B AU Huffman, GJ Adler, RF Nelkin, EJ AF Huffman, GJ Adler, RF Nelkin, EJ GP AMER METEOROL SOC AMER METEOROL SOC TI Climatological seasonal cycles as depicted in global precipitation data sets SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Huffman, GJ (reprint author), NASA, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 78 EP 79 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200022 ER PT B AU Morris, KL Olson, JO Seals, RK Dunkum, RC AF Morris, KL Olson, JO Seals, RK Dunkum, RC GP AMER METEOROL SOC AMER METEOROL SOC TI Long-term radiation budget data available from the Earth Observing System (EOS) Data and Information System (EOSDIS) Langley Distributed Active Archive Center (DAAC) SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 NASA, Langley Res Ctr, Distributed Act Arch Ctr, Hampton, VA 23681 USA. RP Morris, KL (reprint author), NASA, Langley Res Ctr, Distributed Act Arch Ctr, Mail Stop 157D, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 100 EP 102 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200030 ER PT B AU Liu, WT Xie, XS AF Liu, WT Xie, XS GP AMER METEOROL SOC AMER METEOROL SOC TI Interannual to decadal variabilities in the Pacific basin in an ocean general circulation model SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Liu, WT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-323, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 130 EP 134 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200040 ER PT B AU Anyamba, E Susskind, J AF Anyamba, E Susskind, J GP AMER METEOROL SOC AMER METEOROL SOC TI The ENSO signal in the GLA TOVS surface air temperature SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Anyamba, E (reprint author), NASA, Goddard Space Flight Ctr, Code 910-4, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 172 EP 175 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200051 ER PT B AU Marcus, SL Ghil, M AF Marcus, SL Ghil, M GP AMER METEOROL SOC AMER METEOROL SOC TI Century-scale solar variability and the instrumental temperature record SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Marcus, SL (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 AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 220 EP 224 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200064 ER PT B AU Rind, D Lean, J AF Rind, D Lean, J GP AMER METEOROL SOC AMER METEOROL SOC TI The possible effects of solar variability on climate for the last 400 years SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Rind, D (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 235 EP 236 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200068 ER PT B AU Lau, KM Weng, HY AF Lau, KM Weng, HY GP AMER METEOROL SOC AMER METEOROL SOC TI Interannual, interdecadal and global warming signals in sea surface temperature SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. RP Lau, KM (reprint author), NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Code 913, Greenbelt, MD 20771 USA. RI Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 237 EP 240 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200069 ER PT B AU Wetzel, PJ AF Wetzel, PJ GP AMER METEOROL SOC AMER METEOROL SOC TI The icehouse hypothesis: Conditional polar surface cooling caused by man SO NINTH SYMPOSIUM ON GLOBAL CHANGE STUDIES LA English DT Proceedings Paper CT 9th Symposium on Global Change Studies/Namias Symposium on Status and Prospects for Climate Prediction at the 78th American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 NASA, Goddard Space Flight Ctr, Mesoscale Atmos Proc Branch, Greenbelt, MD 20771 USA. RP Wetzel, PJ (reprint author), NASA, Goddard Space Flight Ctr, Mesoscale Atmos Proc Branch, Code 912, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 242 EP 246 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL80D UT WOS:000076779200071 ER PT S AU Bicknell-Tassius, RN Deelman, PW Grunthaner, PJ Grunthaner, FJ Bryson, CE Snyder, E Giuliani, JL Apruzes, JP Kepple, P AF Bicknell-Tassius, RN Deelman, PW Grunthaner, PJ Grunthaner, FJ Bryson, CE Snyder, E Giuliani, JL Apruzes, JP Kepple, P BE Ponce, FA DenBaars, SP Meyer, BK Nakamura, S Strite, S TI Design and characterization of a UHV arcjet nitrogen source SO NITRIDE SEMICONDUCTORS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nitride Semiconductors, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc, Aixtron Semiconductor Technol GmbH, Bede Sci Inc, EMCORE, Lake Shore Cryotron Inc, Morton Int, MMR Technol Inc, Nichia Chem Ind, Renishaw PLC, Rockwell Int, Siemens, SULA Technol, SVT Assoc Inc, Thomas Swan & Co Ltd, Toyoda Gosel Co Ltd, Xerox Palo Alto Res Ctr AB A UHV-compatible nitrogen arcjet suitable for the growth of m-nitrides by molecular beam epitaxy is described and characterized. The arcjet operates at powers between 10W and 300W (the highest power used for these studies); typical nitrogen flows range between 5sccm and 100sccm. Optical emission spectra show the presence of activated atomic (N*) and molecular (N-2*) nitrogen. A collisional radiative equilibrium model has been employed to provide insight into the excitation state of the active nitrogen. These results indicate that the arcjet is capable of supplying atomic nitrogen fluxes consistent with growth rates on the order of several monolayers per second. Langmuir probe measurements conducted near the position of the sample holder in the MBE chamber show the charged particle flux density is very low. The arcjet operates over a large power-pressure parameter space, and properties of the are can be systematically "tuned" to provide a source suitable for selected-energy-epitaxy. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bicknell-Tassius, RN (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 MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-387-8 J9 MATER RES SOC SYMP P PY 1998 VL 482 BP 325 EP 330 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Engineering; Materials Science GA BK98K UT WOS:000073983100048 ER PT B AU Prosser, WH Seale, MD Smith, BT AF Prosser, WH Seale, MD Smith, BT BE Green, RE TI Application of the pseudo Wigner-Ville distribution to the measurement of the dispersion of lamb modes in graphite/epoxy plates SO NONDESTRUCTIVE CHARACTERIZATION OF MATERIALS VIII LA English DT Proceedings Paper CT 8th International Symposium on Nondestructive Characterization of Materials CY JUN 15-20, 1997 CL BOULDER, CO SP Amer Soc Nondestructive Testing, Fed Aviat Adm, Fed Highway Adm, NASA Langley Res Ctr, Natl Inst Stand & Technol, Natl Sci Fdn, USAF, Wright Labs, USN, Naval Surface Warfare Ctr C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Prosser, WH (reprint author), NASA, Langley Res Ctr, MS 231, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-45900-0 PY 1998 BP 609 EP 614 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA BL94P UT WOS:000077254000095 ER PT B AU Roth, DJ Carney, DV AF Roth, DJ Carney, DV BE Green, RE TI Initial results of applying single transducer thickness-independent ultrasonic imaging to tubular structures SO NONDESTRUCTIVE CHARACTERIZATION OF MATERIALS VIII LA English DT Proceedings Paper CT 8th International Symposium on Nondestructive Characterization of Materials CY JUN 15-20, 1997 CL BOULDER, CO SP Amer Soc Nondestructive Testing, Fed Aviat Adm, Fed Highway Adm, NASA Langley Res Ctr, Natl Inst Stand & Technol, Natl Sci Fdn, USAF, Wright Labs, USN, Naval Surface Warfare Ctr AB A single transducer ultrasonic imaging method that eliminates the effect of thickness variation in the image, and its application to hollow tubular/cylindrical structures, are described. The method, based on the measurement of ultrasonic velocity, thus isolates ultrasonic variations due to material microstructure. Its use can result in significant cost savings because the ultrasonic image, and consequently assessment of material and manufacturing quality, can be interpreted correctly without the need for precision thickness machining during nondestructive evaluation stages of material development. Additionally, it may be applicable to net shape parts having nonuniform thickness. The method has been commercialized via a cooperative agreement between NASA Lewis Research Center and Sonix, Inc. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Roth, DJ (reprint author), NASA, Lewis Res Ctr, MS 6-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-45900-0 PY 1998 BP 725 EP 731 PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA BL94P UT WOS:000077254000114 ER PT S AU Plotnikov, YA Winfree, WP AF Plotnikov, YA Winfree, WP BE Geithman, GA Georgeson, GE TI Automation of the image analysis for thermographic inspection SO NONDESTRUCTIVE EVALUATION OF AGING AIRCRAFT, AIRPORTS, AND AEROSPACE HARDWARE II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nondestructive Evaluation of Aging Aircraft, Airports and Aerospace Hardware II CY MAR 31-APR 02, 1998 CL SAN ANTONIO, TX SP Soc Photo Opt Instrumentat Engineers, Fed Aviat Adm, Nondestruct Testing Informat Anal Ctr, Fed Highway Adm, Natl Inst Stand & Technol, Lawrence Livermore Natl Lab, Def Adv Res Projects Agcy, Soc Exptl Mech Inc, Japan Soc Mech Engineers, Japanese Soc Nondestruct Inspect, USAF Res Lab, Pressure Vessel Res Council, Gas Res Inst, Amer Soc Nondestruct Testing DE infrared thermography; image analysis; thermal contrast; inverse problem; thermal tomography AB Several data processing procedures for the pulse thermal inspection require preliminary determination of an unflawed region. Typically, an initial analysis of the thermal images is performed by an operator to determine the locations of unflawed and the defective areas. In the present work an algorithm is developed for automatically determining a reference point corresponding to an unflawed region. Results are obtained for defects which are arbitrarily located in the inspection region. A comparison is presented of the distributions of derived values with right and wrong localization of the reference point. Different algorithms of automatic determination of the reference point are compared. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Plotnikov, YA (reprint author), NASA, Langley Res Ctr, MS231, Hampton, VA 23681 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2846-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3397 BP 135 EP 140 DI 10.1117/12.305044 PG 6 WC Engineering, Aerospace; Materials Science, Characterization & Testing; Optics SC Engineering; Materials Science; Optics GA BK63P UT WOS:000072822000014 ER PT S AU Roth, DJ Carney, DV AF Roth, DJ Carney, DV BE Schilling, CH Gray, JN TI Thickness-independent ultrasonic imaging applied to ceramic materials SO NONDESTRUCTIVE EVALUATION OF CERAMICS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Nondestructive Evaluation of Ceramics, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 04-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB A single transducer ultrasonic imaging method that eliminates the effect of thickness variation in the image, and its application to plate and hollow tubular ceramic materials, are described. The method thus isolates ultrasonic variations due to material microstructure. Its use can result in significant cost savings, because the ultrasonic image, and consequently assessment of material and manufacturing quality, can be interpreted correctly without the need for precision thickness machining during nondestructive evaluation stages of material development. The thickness-independent ultrasonic imaging method is shown to provide more accurate and quantitative materials characterization as compared to that for conventional ultrasonic c-scan and apparent velocity images. The method has been commercialized via a cooperative agreement between NASA Lewis Research Center and Sonix, Inc. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Roth, DJ (reprint author), NASA, Lewis Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-037-8 J9 CERAM TRANS PY 1998 VL 89 BP 253 EP 263 PG 11 WC Materials Science, Ceramics; Materials Science, Characterization & Testing SC Materials Science GA BL07M UT WOS:000074177600021 ER PT S AU Bar-Cohen, Y Mal, A Chang, ZS AF Bar-Cohen, Y Mal, A Chang, ZS BE Doctor, SR Lebowitz, CA Baaklini, GY TI Composite material defects characterization using leaky lamb wave dispersion data SO NONDESTRUCTIVE EVALUATION OF MATERIALS AND COMPOSITES II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nondestructive Evaluation of Materials and Composites II CY MAR 31-APR 01, 1998 CL SAN ANTONIO, TX SP Soc Photo Opt Instrumentat Engineers, Fed Aviat Adm, Nondestruct Testing Informat Anal Ctr, Fed Highway Adm, Natl Inst Stand & Technol, Lawrence Livermore Natl Lab, Def Adv Res Projects Agcy, Soc Exptl Mech, Japan Soc Mech Engineers, Japanese Soc Nondestruct Inspect, USAF Res Lab, Pressure Vessel Res Council, Gas Res Inst, Amer Soc Nondestruct Testing DE NDE; LLW; leaky lamb wave; ultrasonics; defects characterization; elastic properties; composites AB Leaky Lamb wave (LLW) propagation in composite materials has been studied extensively since it was first observed in 1982. The wave is induced using a pitch-catch arrangement and the plate wave modes are detected by identifying minima in the reflected spectra to obtain the dispersion data. The wave behavior in multi-orientation laminates was well documented and corroborated experimentally with a very high accuracy. The sensitivity of the wave to the elastic constants of the material and to its boundary condition led to several studies where the elastic properties were inverted and the characteristics of bonded joint were evaluated Recently, the authors modified their experimental setup to allow measuring dispersion curves at a significantly higher speed than ever recorded. A set of 20 angles of incidence along a single polar angle of a composite laminate are acquired in about 45 seconds. The reflection spectra are acquired in real time while filtering the high frequency noise providing reliable data at amplitude levels that are significantly lower that were acquired in prior studies. This new method makes the LLW a practical quantitative tool for both inversion of the elastic properties and characterization of flaws. The emphasis of the current study is on the detection and characterization of flaws. The composite is modeled as transversely isotropic and dissipative medium and the effect of flaws is analyzed and compared to the experimental data using a C-scan mounted LLW scanner. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 4 Z9 4 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2845-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3396 BP 180 EP 186 DI 10.1117/12.301519 PG 3 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Optics SC Materials Science; Optics GA BK61L UT WOS:000072738100020 ER PT S AU Kazanas, D Hua, XM AF Kazanas, D Hua, XM BE Buchler, JR Gottesman, ST Kandrup, HE TI Modeling the time variability of black hole candidates SO NONLINEAR DYNAMICS AND CHAOS IN ASTROPHYSICS: FESTSCHRIFT IN HONOR OF GEORGE CONTOPOULOS SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT 13th Conference on Nonlinear Dynamics and Chaos in Astrophysics CY FEB 12-14, 1998 CL GAINESVILLE, FL SP Univ Florida, Coll Liberal Arts & Sci, Univ Florida, Dept Phys & Astron, Natl Sci Fdn, Univ Florida, Off Res Technol & Grad Educ ID ACTIVE GALACTIC NUCLEI; X-RAY VARIABILITY; CYGNUS X-1; COMPTONIZATION MODELS; ACCRETION DISKS; SPECTRA; RADIATION; STATE AB We present model light curves for accreting black hole candidates (BHC) based on a recently developed model of these sources. According to this model, the observed light curves and aperiodic variability of BHC are due to a series of soft photon injections at random (Poisson) intervals and the stochastic nature of the Comptonization process in converting these soft photons to the observed high energy radiation. The additional assumption of our model is that the Comptonization process takes place in an extended but nonuniform hot plasma corona surrounding the compact object. We compute the corresponding power spectral densities (PSD), autocorrelation functions, time skewness of the light curves, and time lags between the light curves of the sources at different photon energies and compare our results to observation. Our model reproduces the observed light curves well, in that it provides good fits to their overall morphology (as manifest by the autocorrelation and time skewness) and also to their PSDs and time lags, by producing most of the variability power at time scales greater than or similar to a few seconds, while at the same time allowing for shots of a few msec in duration, in accordance with observation. We suggest that refinement of this type of model along with spectral and phase lag information can be used to probe the structure of this class of high energy sources. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. NR 24 TC 0 Z9 0 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-162-6 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1998 VL 867 BP 283 EP 297 DI 10.1111/j.1749-6632.1998.tb11264.x PG 15 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BM75A UT WOS:000079684900019 PM 12088046 ER PT J AU Smith, AE Petruzzo, JJ Gregory, JC Thoburn, C Austin, RW Derrickson, JH Parnell, TA Masheder, MRW Fowler, PH AF Smith, AE Petruzzo, JJ Gregory, JC Thoburn, C Austin, RW Derrickson, JH Parnell, TA Masheder, MRW Fowler, PH TI Design and flight performance of the cosmic ray detector BUGS-4 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID ENERGY-SPECTRA; ABUNDANCES; ELEMENTS; NUCLEI AB The design features and operational performance from the test flight of the fourth generation of spherical geometry cosmic ray detectors developed at Bristol University (Bristol University Gas Scintillator 4 -BUGS-4) are presented. The flight from Ft. Summer (NM) in September 1993 was the premier flight of a large (Im radius) spherical drift chamber which also gave gas scintillation and Cherenkov signals. The combinations of this chamber with one gas and two solid Cherenkov radiators lead to a large aperture factor (4.5 m(2) sr), but low (similar to 3.5 g/cm(2)) instrument mass over the energy sensitive range 1 to several hundred GeV/a. Moreover, one simple timing measurement determined the impact parameter which provided a trajectory (path length) correction for all detector elements. This innovative and efficient design will be of interest to experimental groups engaged in studies of energetic charged particles. Although then were technical problems on the flight, which were compounded by the total destruction of BUGS-4 by fire whilst landing in Oklahoma, there was a period of stable operation during which the instrument was exposed at float altitude (similar to 125 000 ft) to high-energy cosmic rays. We present the performance of the instrument as determined from the analysis of these data and an appraisal of its novel design features. Suggestions for design improvements in a future instrument are made. C1 Univ Alabama, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. RP Smith, AE (reprint author), Univ Alabama, Huntsville, AL 35899 USA. NR 20 TC 1 Z9 1 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 JAN 1 PY 1998 VL 402 IS 1 BP 104 EP 122 DI 10.1016/S0168-9002(97)00994-7 PG 19 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YR237 UT WOS:000071474700011 ER PT J AU Petruzzo, JJ Smith, AE Gregory, JC Thoburn, C Austin, RW Parnell, TA Derrickson, JH Masheder, MRW Fowler, PH AF Petruzzo, JJ Smith, AE Gregory, JC Thoburn, C Austin, RW Parnell, TA Derrickson, JH Masheder, MRW Fowler, PH TI A 1 m radius spherical electron drift chamber for the measurement of relativistic heavy nuclei SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB The performance of the spherical drift chamber of the BUGS IV (Bristol University Gas Scintillator) cosmic ray detector is presented. The Im radius spherical chamber employed Ar-N-2 gas scintillation, gas-proportional scintillation, and electron drift timing to provide charge, energy, and pathlength correction information. The details of the scintillation and drift processes are presented and the combination of these techniques in the BUGS IV central drift chamber are discussed. The performance of a recent exposure of the BUGS IV central spherical chamber to relativistic cosmic ray iron nuclei is presented. It is shown that the chamber provided pathlength corrections to all elements of this multi-detector experiment with relative uncertainties of less than 2% for 90% of all impact parameters. The maximum uncertainty for the largest impact parameter events remained less than 5%. Model drift waveforms are derived and shown to be in excellent agreement with the observed data. C1 NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. Univ Alabama, Huntsville, AL 35899 USA. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. RP Derrickson, JH (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Lab, ES-84, Huntsville, AL 35812 USA. EM james.derrickson@msfc.nasa.gov NR 21 TC 2 Z9 2 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 JAN 1 PY 1998 VL 402 IS 1 BP 123 EP 138 DI 10.1016/S0168-9002(97)00993-5 PG 16 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YR237 UT WOS:000071474700012 ER PT J AU Singh, JJ Pater, RH Eftekhari, A AF Singh, JJ Pater, RH Eftekhari, A TI Microstructural characterization of semi-interpenetrating polymer networks by positron lifetime spectroscopy SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE semi-interpenetrating polymer networks; positron annihilation spectroscopy; free volume; electrostatic bonding; dielectric constant; density ID PRESSURE-DEPENDENCE; ANNIHILATION AB Thermoset and thermoplastic polyimides have complementary physical/mechanical properties. Whereas thermoset polyimides are brittle and generally easier to process, thermoplastic polyimides are tough but harder to process. II is expected that a combination of these two types of polyimides may help produce polymers more suitable for aerospace applications. Semi-Interpenetrating Polymer Networks (S-IPNs) of thermoset LaRC(TM)-RP46 and thermoplastic LaRC(TM)-IA polyimides were prepared in weight percent ratios ranging from 100:0 to 0:100. Positron lifetime measurements were made in these samples to correlate their free volume features with physical/mechanical properties. As expected, positronium atoms are not formed in these samples. The second life time component has been used to infer the positron trap dimensions. The "free volume" goes through a minimum at about 50:50 ratio, suggesting that S-IPN samples are not merely solid solutions of the two polymers. These data and related structural properties of the S-IPN samples have been discussed in this paper. Published by Elsevier Science B.V. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Singh, JJ (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 11 TC 4 Z9 4 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JAN PY 1998 VL 134 IS 1 BP 113 EP 120 DI 10.1016/S0168-583X(98)80040-2 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YR238 UT WOS:000071474800014 ER PT J AU Lavigne, JM Jean, P Kandel, B Borrel, V Roques, JP Lichti, G Schonfelder, V Diehl, R Georgii, R Kirchner, T Durouchoux, P Cordier, B Diallo, N Sanchez, F Payne, B Leleux, P Teegarden, B Matteson, J Slassi-Sennou, S Skinner, G Connell, P AF Lavigne, JM Jean, P Kandel, B Borrel, V Roques, JP Lichti, G Schonfelder, V Diehl, R Georgii, R Kirchner, T Durouchoux, P Cordier, B Diallo, N Sanchez, F Payne, B Leleux, P Teegarden, B Matteson, J Slassi-Sennou, S Skinner, G Connell, P TI The INTEGRAL experiment SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 15th European Cosmic Ray Symposium CY AUG 26-30, 1996 CL UNIV PERPIGNAN, PERPIGNAN, FRANCE SP Univ Perpignan, CNRS, Particle Phys Labs, Univ Paris, Univ Bordeaux, Univ Toulouse, Coll France, Ecole Polytech, CEA, Int Union Pure & Appl Phys, European Members Cosmic Ray Commiss HO UNIV PERPIGNAN DE gamma-ray astronomy; gamma-ray spectroscopy; gamma-ray telescope INTEGRAL AB The International Gamma-ray Astrophysics Laboratory (INTEGRAL) is conceived as the next logical step in gamma-ray astronomy after the US Compton Gamma-Ray Observatory (CGRO) and the French/Russian SIGMA mission. The INTEGRAL scientific payload consists of two main instruments (Imager and Spectrometer) and two monitor instruments (X-Ray Monitor and Optical Transient Camera). The INTEGRAL spectrometer "SPI" is optimized for detailed measurements of gamma-ray lines and mapping of diffuse sources. It combines a coded aperture mask with an array of large volume, high-purity germanium detectors. The detectors make precise measurements of the gamma-ray energies over the 20 keV-8 MeV energy range. This paper presents the instrument characteristics these properties have been evaluated by means of Monte Carlo calculations. With the characteristic features It will be possible to study gamma-ray emission from compact objects or line profiles with a high-energy resolution and a good angular resolution. C1 Ctr Etud Spatiale Rayonnements, F-31029 Toulouse, France. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. CEA Saclay, SAP, F-91191 Gif Sur Yvette, France. Univ Valencia, IFIC, E-46100 Burjassot, Spain. Univ Catholique Louvain, Inst Phys Nucl, B-1348 Louvain, Belgium. CNR, Ist Fis Cosm, I-20144 Milan, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif San Diego, CASS 0111, La Jolla, CA 92093 USA. Univ Calif Berkeley, SSL, Berkeley, CA 94720 USA. Univ Birmingham, Space Res Grp, Birmingham B15 2TT, W Midlands, England. RP Lavigne, JM (reprint author), Ctr Etud Spatiale Rayonnements, BP 4346, F-31029 Toulouse, France. RI Sanchez, Filomeno/D-7859-2014; OI Sanchez, Filomeno/0000-0003-0831-4744; Caraveo, Patrizia/0000-0003-2478-8018 NR 2 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JAN PY 1998 SU 60B BP 69 EP 79 DI 10.1016/S0920-5632(97)00502-1 PG 11 WC Physics, Particles & Fields SC Physics GA YN087 UT WOS:000071131800008 ER PT J AU Takahashi, Y Asakimori, K Burnett, TH Cherry, ML Chevli, K Christl, MJ Dake, S Derrickson, JH Fountain, WF Fuki, M Gregory, JC Holynski, R Iwai, J Iyono, A Jones, MV Jurak, A Kobayashi, M Lord, JJ Miyamura, O Oda, H Ogata, T Olson, ED Parnell, TA Roberts, FE Shiina, T Strausz, SC Tominaga, T Toyoda, S Watts, JW Wefel Wilczynka, B Wilczynski, H Wilkes, RJ Wolter, W Wosiek, B Yokomi, H Zager, EL AF Takahashi, Y Asakimori, K Burnett, TH Cherry, ML Chevli, K Christl, MJ Dake, S Derrickson, JH Fountain, WF Fuki, M Gregory, JC Holynski, R Iwai, J Iyono, A Jones, MV Jurak, A Kobayashi, M Lord, JJ Miyamura, O Oda, H Ogata, T Olson, ED Parnell, TA Roberts, FE Shiina, T Strausz, SC Tominaga, T Toyoda, S Watts, JW Wefel Wilczynka, B Wilczynski, H Wilkes, RJ Wolter, W Wosiek, B Yokomi, H Zager, EL CA JACEE Collaboration TI Elemental abundance of high energy cosmic rays SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 15th European Cosmic Ray Symposium CY AUG 26-30, 1996 CL UNIV PERPIGNAN, PERPIGNAN, FRANCE SP Univ Perpignan, CNRS, Particle Phys Labs, Univ Paris, Univ Bordeaux, Univ Toulouse, Coll France, Ecole Polytech, CEA, Int Union Pure & Appl Phys, European Members Cosmic Ray Commiss HO UNIV PERPIGNAN ID EMULSION CHAMBERS; SPECTRA; SHOCKS; ORIGIN AB Very high energy spectra of cosmic ray nuclei from the JACEE balloon experiments are presented. From a total of 12 balloon flights with an exposure factor of about 580 m(2) hour the energy spectra of nuclei have been obtained in the energy range from several TeV to 1,000 TeV. Proton energy spectrum, extending to several hundred TeV, can be a single-power law. Helium shows a single power law spectrum in the energy range from 2 TeV/n to 200 TeV/n. Other nuclei up to Fe indicated harder spectral indices compared with those of protons and helium. The composition at around 500 TeV is 16 +/- 5%: 29 +/- 5%: 35 +/- 5%: 9 +/- 3%: 11 +/- 4%, for the abundance of p : He : C similar to O : Ne similar to S : Z greater than or equal to 18. C1 Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. Univ Tokyo, Bunkyo Ku, Tokyo 113, Japan. Hiroshima Univ, Hiroshima 730, Japan. Kobe Univ, Kobe, Hyogo 657, Japan. Kobe Womens Coll Pharm, Higashinada Ku, Kobe, Hyogo 658, Japan. Kochi Univ, Kochi 780, Japan. Natl Lab High Energy Phys, Ibaraki, Osaka, Japan. Okayama Univ Sci, Okayama 700, Japan. Tezukayama Univ, Nara, Japan. Louisiana State Univ, Baton Rouge, LA 70803 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Washington, Seattle, WA 98195 USA. Inst Nucl Phys, Krakow, Poland. RP Takahashi, Y (reprint author), Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RI Wilkes, R.Jeffrey/E-6011-2013; Toyoda, Sakae/J-7151-2013 NR 32 TC 24 Z9 24 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JAN PY 1998 SU 60B BP 83 EP 92 DI 10.1016/S0920-5632(97)00503-3 PG 10 WC Physics, Particles & Fields SC Physics GA YN087 UT WOS:000071131800009 ER PT J AU Sidi, A Shapira, Y AF Sidi, A Shapira, Y TI Upper bounds for convergence rates of acceleration methods with initial iterations SO NUMERICAL ALGORITHMS LA English DT Article ID LINEAR-EQUATIONS; NONSYMMETRIC SYSTEMS; GMRES AB GMRES(n, k), a version of GMRES for the solution of large sparse linear systems, is introduced. A cycle of GMRES(n, k) consists of n Richardson iterations followed by k iterations of GMRES. Such cycles can be repeated until convergence is achieved. The advantage in this approach is in the opportunity to use moderate k, which results in time and memory saving. Because the number of inner products among the vectors of iteration is about k(2)/2, using a moderate k is particularly attractive on message-passing parallel architectures, where inner products require expensive global communication. The present analysis provides tight upper bounds for the convergence rates of GMRES(n, k) for problems with diagonalizable coefficient matrices whose spectra lie in an ellipse in C\{0}. The advantage of GMRES(n, k) over GMRES(k) is illustrated numerically. C1 Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel. NASA, Inst Computat Mech Prop, Lewis Res Ctr, Cleveland, OH 44135 USA. Technion Israel Inst Technol, Dept Math, IL-32000 Haifa, Israel. NR 39 TC 11 Z9 11 U1 0 U2 0 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 1017-1398 J9 NUMER ALGORITHMS JI Numer. Algorithms PY 1998 VL 18 IS 2 BP 113 EP 132 DI 10.1023/A:1019113314010 PG 20 WC Mathematics, Applied SC Mathematics GA 148NW UT WOS:000077539600001 ER PT B AU Stanley, JD AF Stanley, JD BE Wallace, JW Steinman, J Davani, D Elizandro, D TI An object oriented approach for modeling interactions of space station components in a distributed simulation environment - (or how MOM, POP, KIDS, DOC and the DOG help train the space station astronauts) SO OBJECT-ORIENTED SIMULATION CONFERENCE (OOS'98) AND THE INTERNATIONAL CONFERENCE ON SIMULATION AND MULTIMEDIA IN ENGINEERING EDUCATION (ICSEE'98), PROCEEDINGS OF LA English DT Proceedings Paper CT Object-Oriented Simulation Conference/International Conference on Simulation and Multimedia in Engineering Education at the 1998 Western MultiConference CY JAN 11-14, 1998 CL SAN DIEGO, CA SP Soc Comp Simulat Int C1 NASA, Lyndon B Johnson Space Ctr, Space Stn Training Facil, Houston, TX 77058 USA. RP Stanley, JD (reprint author), NASA, Lyndon B Johnson Space Ctr, Space Stn Training Facil, Houston, TX 77058 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC COMPUTER SIMULATION PI SAN DIEGO PA PO BOX 17900, SAN DIEGO, CA 92177 USA BN 1-56555-142-7 PY 1998 BP 129 EP 134 PG 6 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BN55E UT WOS:000082192200017 ER PT S AU Norton, CD Decyk, V Slottow, J AF Norton, CD Decyk, V Slottow, J BE Demeyer, S Bosch, J TI Applying Fortran 90 and object-oriented techniques to scientific applications SO OBJECT-ORIENTED TECHNOLOGY: ECOOP'98 WORKSHOP READER SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT ECOOP 98 Workshop on Object-Oriented Technology CY JUL 20-24, 1998 CL BRUSSELS, BELGIUM C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA USA. Univ Calif Los Angeles, Off Acad Comp, Los Angeles, CA USA. RP Norton, CD (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 2 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-65460-7 J9 LECT NOTES COMPUT SC PY 1998 VL 1543 BP 462 EP 463 PG 2 WC Computer Science, Theory & Methods SC Computer Science GA BN79M UT WOS:000082950200182 ER EF