FN Thomson Reuters Web of Science™ VR 1.0 PT J AU PALMER, LC LABORDE, E STERN, A SOHN, PY AF PALMER, LC LABORDE, E STERN, A SOHN, PY TI A PERSONAL COMMUNICATIONS NETWORK USING A KA-BAND SATELLITE SO IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS LA English DT Article AB The feasibility of a personal communications network using portable terminals that can provide 4.8 Kb/s voice communications to a hub station via a Ka-band geosynchronous satellite has been investigated. Tradeoffs are examined so that the combined system of hub and gateway earth stations, the satellite, and the personal terminals can provide a competitive service in terms of cost, availability, and quality. A baseline system that uses a spacecraft with approximately 140 spot beams to cover CONUS and 5 W power amplifiers in each beam is described. Satellite access in both the forward and return directions uses frequency division multiple access/code division multiple access (FDMA/CDMA) with a chip rate of 2.5 Mchip/s. The development of such a system at Ka-band can follow only after technological developments in the areas of critical RF elements including antennas and high-power amplifiers (HPA's) at 30 GHz and experiments to demonstrate some of the features of the portable terminal concept. C1 GE,DIV ASTRO SPACE,DEPT COMMUN SYST DESIGN,PRINCETON,NJ 08543. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP PALMER, LC (reprint author), HUGHES NETWORK SYST INC,SYST GRP,GERMANTOWN,MD 20876, USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0733-8716 J9 IEEE J SEL AREA COMM JI IEEE J. Sel. Areas Commun. PD FEB PY 1992 VL 10 IS 2 BP 401 EP 417 DI 10.1109/49.126991 PG 17 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA HE822 UT WOS:A1992HE82200011 ER PT J AU REINHART, EE TAYLOR, RM HEYWARD, AO MILLER, J AF REINHART, EE TAYLOR, RM HEYWARD, AO MILLER, J TI WARCS LAST ACT SO IEEE SPECTRUM LA English DT Article C1 NASA,OFF SPACE OPERAT,WASHINGTON,DC 20546. NASA,OFF COMMERCIAL PROGRAMS,WASHINGTON,DC 20546. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD FEB PY 1992 VL 29 IS 2 BP 20 EP 23 DI 10.1109/6.119600 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA HC315 UT WOS:A1992HC31500008 ER PT J AU TAYLOR, RM AF TAYLOR, RM TI SPACE COMMUNICATIONS SO IEEE SPECTRUM LA English DT Article RP TAYLOR, RM (reprint author), NASA,OFF SPACE OPERAT,WASHINGTON,DC 20546, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD FEB PY 1992 VL 29 IS 2 BP 30 EP 33 DI 10.1109/6.119606 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA HC315 UT WOS:A1992HC31500013 ER PT J AU HEYWARD, AO AF HEYWARD, AO TI A BEACON FOR UPLINK POWER-CONTROL SO IEEE SPECTRUM LA English DT Article RP HEYWARD, AO (reprint author), NASA,OFF COMMERCIAL PROGRAMS,WASHINGTON,DC 20546, 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 SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD FEB PY 1992 VL 29 IS 2 BP 32 EP 32 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA HC315 UT WOS:A1992HC31500014 ER PT J AU HEYWARD, AO AF HEYWARD, AO TI MULTIPURPOSE SATELLITE ALLOCATIONS SO IEEE SPECTRUM LA English DT Article RP HEYWARD, AO (reprint author), NASA,OFF COMMERCIAL PROGRAMS,WASHINGTON,DC 20546, 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 SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD FEB PY 1992 VL 29 IS 2 BP 33 EP 33 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA HC315 UT WOS:A1992HC31500015 ER PT J AU WEN, JT KREUTZDELGADO, K BAYARD, DS AF WEN, JT KREUTZDELGADO, K BAYARD, DS TI LYAPUNOV FUNCTION-BASED CONTROL LAWS FOR REVOLUTE ROBOT ARMS - TRACKING CONTROL, ROBUSTNESS, AND ADAPTIVE-CONTROL SO IEEE TRANSACTIONS ON AUTOMATIC CONTROL LA English DT Note ID MANIPULATORS AB A new class of joint level control laws for all-revolute robot arms is introduced in this note. The analysis is similar to the recently proposed energy-like Lyapunov function approach of [1], [2], except that the closed-loop potential function is shaped in accordance with the underlying joint space topology. This approach gives way to a much simpler analysis and leads to a new class of control designs which guarantee both global asymptotic stability and local exponential stability. When Coulomb and viscous friction, and parameter uncertainty are present as model perturbations, a sliding mode-like modification of the control law results in a robustness enhancing outer loop. Adaptive control is formulated within the same framework. A linear-in-the-parameters formulation is adopted and globally asymptotically stable adaptive control laws are derived by simply replacing unknown model parameters by their estimates (i.e., certainty equivalence adaptation). C1 UNIV CALIF SAN DIEGO,DEPT ELECT & COMP ENGN,LA JOLLA,CA 92093. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP WEN, JT (reprint author), RENSSELAER POLYTECH INST,DEPT ELECT COMP & SYST ENGN,TROY,NY 12181, USA. RI Wen, John/B-4474-2008 OI Wen, John/0000-0002-5123-5411 NR 16 TC 25 Z9 25 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9286 J9 IEEE T AUTOMAT CONTR JI IEEE Trans. Autom. Control PD FEB PY 1992 VL 37 IS 2 BP 231 EP 237 DI 10.1109/9.121624 PG 7 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA HB665 UT WOS:A1992HB66500008 ER PT J AU SIMON, MK DIVSALAR, D AF SIMON, MK DIVSALAR, D TI ON THE IMPLEMENTATION AND PERFORMANCE OF SINGLE AND DOUBLE DIFFERENTIAL DETECTION SCHEMES SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article AB It is well known that classical differential detection of MPSK signals, wherein the information is encoded as a first order phase difference, is a simple and robust form of communication in environments not subject to frequency variation. For channels that introduce into the carrier a random frequency shift, e.g., those associated with moving vehicles, classical differential detection as above may yield poor performance, particularly if the frequency shift is an appreciable fraction of the data rate. In such situations, one must resort to a form of differential detection that encodes the information as a higher order (second-order for constant frequency offset) phase difference process. The subject of this paper is the implementation and performance of such double differential detection systems and a comparison with the more well-known classical (single differential detection) systems. Also discussed is the application of the notion of multiple symbol detection, recently introduced in the literature by the authors, to such double differential detection schemes. RP SIMON, MK (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 17 TC 65 Z9 66 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD FEB PY 1992 VL 40 IS 2 BP 278 EP 291 DI 10.1109/26.129190 PG 14 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA HP271 UT WOS:A1992HP27100007 ER PT J AU VIRA, N TUNSTEL, E AF VIRA, N TUNSTEL, E TI USE OF SYMBOLIC COMPUTATION IN ROBOTICS EDUCATION SO IEEE TRANSACTIONS ON EDUCATION LA English DT Article AB This paper describes an application of symbolic computation in robotics education. A software package is presented which combines generality, user interaction, and user-friendliness with the systematic usage of symbolic computation and artificial intelligence techniques. The software utilizes MACSYMA, a LISP-based symbolic algebra language, to generate automatically closed-form expressions representing forward and inverse kinematics solutions, the Jacobian transformation matrices, robot pose error compensation models equations, and Lagrange dynamics formulation for N degree-of-freedom, open chain robotic manipulators. The goal of such a package is to aid faculty and students in the robotics course by removing burdensome tasks of mathematical manipulations. The software package has been successfully tested for its accuracy using commercially available robots. C1 JET PROP LAB,ROBOT INTELLIGENCE GRP,TECH STAFF,PASADENA,CA 91109. RP VIRA, N (reprint author), HOWARD UNIV,DEPT MECH ENGN,WASHINGTON,DC 20059, USA. NR 26 TC 15 Z9 15 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9359 J9 IEEE T EDUC JI IEEE Trans. Educ. PD FEB PY 1992 VL 35 IS 1 BP 18 EP 30 DI 10.1109/13.123413 PG 13 WC Education, Scientific Disciplines; Engineering, Electrical & Electronic SC Education & Educational Research; Engineering GA HH953 UT WOS:A1992HH95300003 ER PT J AU FORMAN, R LESNY, G AF FORMAN, R LESNY, G TI SURFACE STUDIES ON SCANDATE CATHODES AND SYNTHESIZED SCANDATES - REPLY SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Letter C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP FORMAN, R (reprint author), ANALEX CORP,BROOK PK,OH, USA. NR 8 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD FEB PY 1992 VL 39 IS 2 BP 456 EP 457 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA GZ714 UT WOS:A1992GZ71400034 ER PT J AU RODRIGUEZ, G KREUTZDELGADO, K AF RODRIGUEZ, G KREUTZDELGADO, K TI SPATIAL OPERATOR FACTORIZATION AND INVERSION OF THE MANIPULATOR MASS MATRIX SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Article ID ROBOT DYNAMICS; SIMULATION AB Two new recursive factorizations are developed of the mass matrix for fixed-base and mobile-base manipulators. First, the mass matrix M is shown to have the factorization M = H-phi-M-phi*H*. This is referred to here as the Newton-Euler factorization because it is closely related to the recursive Newton-Euler equations of motion. This factorization may be the simplest way to show the equivalence of recursive Newton-Euler and Lagrangian manipulator dynamics. Second, the mass matrix is shown to have a related innovations factorization M = (I + H-PHI-G)D(I + H-PHI-G)*. This leads to an immediate inversion M-1 = (I - H-PSI-G)* D-1 (I - H-PSI-G), where H and PHI are given by known link geometric parameters, and G, PSI and D are obtained by a discrete-step Riccati equation driven by the link masses. The factors (I + H-PHI-G) and (I - H-PSI-G) are lower triangular matrices that are inverses of each other, and D is a diagonal matrix. Efficient order N inverse and forward dynamics algorithms are embedded in the two factorizations. Moreover, the factorizations provide a high-level architectural understanding of the mass matrix and its inverse, which is not available readily from the detailed algorithms. The two factorizations are model-based in the sense that the manipulator model itself determines the sequence of computations. This makes the two factorizations quite distinct from more traditional Cholesky-like numerical factorizations of positive definite matrices. Because the manipulator model is used, every computational step has a corresponding physical interpretation. This adds a substantial amount of robustness, and numerical errors can be detected by physical intuition. Development of the factorizations is made simple by the use of spatial operators, such as phi, PHI and PSI, which govern the propagation of forces, velocities, and accelerations from link to link along the span of the manipulator. C1 UNIV CALIF SAN DIEGO,DEPT ELECT & COMP ENGN,LA JOLLA,CA 92130. RP RODRIGUEZ, G (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 34 TC 41 Z9 46 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD FEB PY 1992 VL 8 IS 1 BP 65 EP 76 DI 10.1109/70.127240 PG 12 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA HE430 UT WOS:A1992HE43000007 ER PT J AU GODDARD, RE ZHENG, YF HEMAMI, H AF GODDARD, RE ZHENG, YF HEMAMI, H TI DYNAMIC HYBRID VELOCITY FORCE CONTROL OF ROBOT COMPLIANT MOTION OVER GLOBALLY UNKNOWN OBJECTS SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Note ID FUNDAMENTAL-CONCEPTS; COMPLAINT MOTION; MANIPULATORS AB The application of robotic manipulators to complex tasks such as assembly or insertion often requires position/force control of the end-effector, and this has been widely studied. A related task is robot compliant motion over unknown objects. The goal is to move the effector, while maintaining contact, about the object. For this application a dynamic hybrid velocity/force controller is studied. The constraints are characterized in the manner proposed by Mason. A nominal velocity trajectory is computed, and nominal hybrid joint commands are explicitly given in terms of the sensed joint coordinates and sensed local contact information. For robustness, servoing is added, and an example design is given. Finally, the step response of the controller is simulated for the case of rolling the effector about an unknown object. C1 OHIO STATE UNIV, DEPT ELECT ENGN, COLUMBUS, OH 43210 USA. RP CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. NR 22 TC 6 Z9 6 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD FEB PY 1992 VL 8 IS 1 BP 132 EP 138 DI 10.1109/70.127248 PG 7 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA HE430 UT WOS:A1992HE43000015 ER PT J AU KELLY, JC SHERIF, YS AF KELLY, JC SHERIF, YS TI COMPARISON OF 4 DESIGN METHODS FOR REAL-TIME SOFTWARE-DEVELOPMENT SO INFORMATION AND SOFTWARE TECHNOLOGY LA English DT Article DE DESIGN METHODS; SOFTWARE DEVELOPMENT; REAL-TIME SOFTWARE DEVELOPMENT ID EXTENSION; SYSTEMS AB Four design methods that are of current interest in real-time software development are compared. The comparison presents the relative strengths and weaknesses of each method, with additional information on graphic notation and the recommended sequence of steps involved in the use of each method. The methods selected for comparison are Structured Design for Real-Time Systems, object-oriented design, PAMELA (Process Abstraction Method for Embedded Large Applications), and SCR (Software Cost Reduction project from the Naval Research Laboratory). C1 CALIF STATE UNIV FULLERTON,FULLERTON,CA 92634. RP KELLY, JC (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 36 TC 4 Z9 4 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0950-5849 J9 INFORM SOFTWARE TECH JI Inf. Softw. Technol. PD FEB PY 1992 VL 34 IS 2 BP 74 EP 82 DI 10.1016/0950-5849(92)90107-Z PG 9 WC Computer Science, Information Systems; Computer Science, Software Engineering SC Computer Science GA HC935 UT WOS:A1992HC93500001 ER PT J AU LOTFI, AW VORPERIAN, V LEE, FC AF LOTFI, AW VORPERIAN, V LEE, FC TI LARGE-SIGNAL, POWER MOSFET SWITCHING TIMES IN PWM, ZERO-CURRENT-SWITCHED AND ZERO-VOLTAGE-SWITCHED DC DC CONVERTERS SO INTERNATIONAL JOURNAL OF ELECTRONICS LA English DT Article AB The large signal switching times of MOSFETs in pulse-width modulated (PWM), zero-current-switched and zero-voltage-switched DC/DC converters contribute to higher losses at increased frequencies of operation. These switching times determine the high frequency limits of the converters. Simple and analytical expressions for these switching times are obtained and the results are verified against SPICE simulations. The important effect of the non-linear drain-to-source capacitance is accounted for. The expressions derived are design oriented, providing the switching times directly from the parameters of the device and its application. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP LOTFI, AW (reprint author), VIRGINIA POLYTECH INST & STATE UNIV,VIRGINIA POWER ELECTR CTR,BRADLEY DEPT ELECT ENGN,BLACKSBURG,VA 24061, USA. NR 12 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0020-7217 J9 INT J ELECTRON JI Int. J. Electron. PD FEB PY 1992 VL 72 IS 2 BP 305 EP 328 DI 10.1080/00207219208925575 PG 24 WC Engineering, Electrical & Electronic SC Engineering GA HF687 UT WOS:A1992HF68700008 ER PT J AU Macaraeg, MG AF Macaraeg, M. G. TI STABILITY OF NON-SIMILAR SHEAR LAYERS SO INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW LA English DT Article DE Mach number; Scramjet engine design; Spatial simulations AB The present study is concerned with the stability and transition of a spatially evolving wake emanating from a splitter plate. Temporal linear stability calculations at different streamwise locations indicate significantly higher growth rates for mean flow profiles which occur near the trailing edge. Spatial simulations using these near wake mean flows exhibit non-linear roll-up for a case with Mach numbers of 2.76 and 1.87 on either side of the wake. If a similarity shear layer mean flow profile with these conditions is utilized in the simulation, no roll-up is obtained. C1 NASA, Langley Res Ctr, Theoret Flow Phys Branch, Hampton, VA 23665 USA. RP Macaraeg, MG (reprint author), NASA, Langley Res Ctr, Theoret Flow Phys Branch, MS156, Hampton, VA 23665 USA. NR 14 TC 1 Z9 1 U1 0 U2 1 PU EMERALD GROUP PUBLISHING LIMITED PI BINGLEY PA HOWARD HOUSE, WAGON LANE, BINGLEY BD16 1WA, W YORKSHIRE, ENGLAND SN 0961-5539 J9 INT J NUMER METHOD H JI Int. J. Numer. Methods Heat Fluid Flow PD FEB PY 1992 VL 2 IS 1 BP 79 EP 86 DI 10.1108/eb017481 PG 8 WC Thermodynamics; Mathematics, Interdisciplinary Applications; Mechanics SC Thermodynamics; Mathematics; Mechanics GA V29HK UT WOS:000208739300006 ER PT J AU Garg, VK AF Garg, Vijay K. TI NATURAL CONVECTION WITHIN A SIMPLIFIED MODEL OF THE HUMAN EYE SO INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW LA English DT Article DE Human eye; Natural convection flow; Temperature distribution AB A finite difference solution for steady natural convective flow within the human eye, modelled as a sphere with a specified temperature distribution over its surface, has been obtained. The stream function-vorticity formulation of the equations of motion for the unsteady axisymmetric flow is used; interest lying in the final steady solution. Forward differences are used for the time derivatives and second-order central differences for the space derivatives. The alternating direction implicit method is used for solution of the discretization equations. Local one-dimensional grid adaptation is used to resolve the steep gradients in some regions of the flow at large Rayleigh numbers. The break-up into multi-cellular flow is found at high Rayleigh numbers. Results identify regions of stagnant fluid in locations similar to those of blind spots in the eye. C1 [Garg, Vijay K.] Univ Pittsburgh, Dept Mech Engn, Pittsburgh, PA 15261 USA. RP Garg, VK (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 18 TC 0 Z9 0 U1 0 U2 2 PU EMERALD GROUP PUBLISHING LIMITED PI BINGLEY PA HOWARD HOUSE, WAGON LANE, BINGLEY BD16 1WA, W YORKSHIRE, ENGLAND SN 0961-5539 J9 INT J NUMER METHOD H JI Int. J. Numer. Methods Heat Fluid Flow PD FEB PY 1992 VL 2 IS 1 BP 227 EP 234 DI 10.1108/eb017491 PG 8 WC Thermodynamics; Mathematics, Interdisciplinary Applications; Mechanics SC Thermodynamics; Mathematics; Mechanics GA V29HK UT WOS:000208739300016 ER PT J AU Leonard, BP Mokhtari, S AF Leonard, B. P. Mokhtari, Simin TI ULTRA-SHARP SOLUTION OF THE SMITH-HUTTON PROBLEM SO INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW LA English DT Article DE Smith-Hutton problem; Highly convective flow; ULTRA-SHARP; QUICK; Non-oscillatory convection; Sharp monotonic simulation; Higher-order convection AB In 1982, Smith and Hutton published comparative results of several different convection diffusion schemes applied to a specially devised test problem involving near-discontinuities and strong streamline curvature. First-order methods showed significant artificial diffusion, whereas higher-order methods gave less smearing. but had a tendency to overshoot and oscillate. Perhaps because unphysical oscillations are more obvious than unphysical smearing, the intervening period has seen a rise in popularity of low-order artificially diffusive schemes, especially in the numerical heat-transfer industry. This paper presents an alternative strategy of using non-artificially diffusive higher-order methods, while maintaining strictly monotonic transitions through the use of simple flux-limiter constraints. Limited third-order upwinding is usually found to be the most cost-effective basic convection scheme. Tighter resolution of discontinuities can be obtained at little additional cost by using automatic adaptive stencil expansion to higher order in local regions, as needed. C1 [Leonard, B. P.] Univ Akron, Ctr Computat Mech, Akron, OH 44325 USA. [Mokhtari, Simin] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Leonard, BP (reprint author), Univ Akron, Ctr Computat Mech, Akron, OH 44325 USA. FU National Science Foundation [ECS-8904595]; Institute for Computational Mechanics in Propulsion (ICOMP) at the NASA Lewis Research Center [C-99066-G] FX Portions of this work were supported by the National Science Foundation under contract ECS-8904595. The first author's research was also partially supported by the Institute for Computational Mechanics in Propulsion (ICOMP) at the NASA Lewis Research Center under Space Act Agreement C-99066-G. NR 34 TC 8 Z9 9 U1 1 U2 3 PU EMERALD GROUP PUBLISHING LIMITED PI BINGLEY PA HOWARD HOUSE, WAGON LANE, BINGLEY BD16 1WA, W YORKSHIRE, ENGLAND SN 0961-5539 J9 INT J NUMER METHOD H JI Int. J. Numer. Methods Heat Fluid Flow PD FEB PY 1992 VL 2 IS 1 BP 407 EP 427 DI 10.1108/eb017502 PG 21 WC Thermodynamics; Mathematics, Interdisciplinary Applications; Mechanics SC Thermodynamics; Mathematics; Mechanics GA V29HK UT WOS:000208739300027 ER PT J AU Garg, VK Szeri, AZ AF Garg, V. K. Szeri, A. Z. TI NATURAL CONVECTION IN A HORIZONTAL CONCENTRIC CYLINDRICAL ANNULUS SO INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW LA English DT Article DE Natural convection; Galerkin-spline formulation; Cylindrical annulus AB This numerical study of natural convection flow in a horizontal cylindrical annulus is aimed at establishing the utility of the Galerkin-spline formulation for natural convection problems. The annulus has isothermal walls and the fluid is of constant material properties except for its density; density variation is incorporated via the Boussinesq approximation. Two formulations are employed, the velocity formulation and the streamfunction formulation. We are able to demonstrate the usefulness of the Galerkin-spline formulation for the problem and in comparison with published data, show that it leads to greater accuracy than the finite difference method. We also show the streamfunction formulation to be superior computationally to the velocity formulation. We find no bifurcation from the basic state up to 60,000 in Grashof number, even without a priori assumption of symmetry about the vertical plane. This last finding is in sharp contrast to results obtained when porous material fills the annulus. C1 [Garg, V. K.; Szeri, A. Z.] Univ Pittsburgh, Dept Mech Engn, Pittsburgh, PA 15261 USA. RP Garg, VK (reprint author), NASA, Lewis Res Ctr, Mail Stop 5-11, Cleveland, OH 44135 USA. FU NSF [MSM-8619048] FX A.Z.S. was partially supported by NSF under Grant No. MSM-8619048, during this project. Computing was made possible through a grant by the Pittsburgh Supercomputing Center for use of its CRAY Y-MP/832. Both of these supports are gratefully acknowledged. NR 28 TC 1 Z9 1 U1 0 U2 0 PU EMERALD GROUP PUBLISHING LIMITED PI BINGLEY PA HOWARD HOUSE, WAGON LANE, BINGLEY BD16 1WA, W YORKSHIRE, ENGLAND SN 0961-5539 J9 INT J NUMER METHOD H JI Int. J. Numer. Methods Heat Fluid Flow PD FEB PY 1992 VL 2 IS 1 BP 455 EP 467 DI 10.1108/eb017505 PG 13 WC Thermodynamics; Mathematics, Interdisciplinary Applications; Mechanics SC Thermodynamics; Mathematics; Mechanics GA V29HK UT WOS:000208739300030 ER PT J AU Ramakrishnan, R Wieting, AR Thornton, EA AF Ramakrishnan, R. Wieting, Allan R. Thornton, Earl A. TI A TRANSIENT FINITE ELEMENT ADAPTATION SCHEME FOR THERMAL PROBLEMS WITH STEEP GRADIENTS SO INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW LA English DT Article DE Aerodynamic heating; Mesh adaptation; Finite element scheme AB An adaptive mesh refinement procedure that uses nodeless variables and quadratic interpolation functions is presented for analysing transient thermal problems. A temperature based finite element scheme with Crank-Nicolson time marching is used to obtain the thermal solution. The strategies used for mesh adaptation, computing refinement indicators, and time marching are described. Examples in one and two dimensions are presented and comparisons are made with exact solutions. The effectiveness of this procedure for transient thermal analysis is reflected in good solution accuracy, reduction in number of elements used, and computational efficiency. C1 [Ramakrishnan, R.] NASA, Langley Res Ctr, Analyt Serv & Mat Inc, Hampton, VA 23665 USA. [Wieting, Allan R.] NASA, Langley Res Ctr, Hampton, VA 23665 USA. [Thornton, Earl A.] Univ Virginia, Charlottesville, VA USA. RP Ramakrishnan, R (reprint author), NASA, Langley Res Ctr, Analyt Serv & Mat Inc, MS 156, Hampton, VA 23665 USA. FU Aerothermal Loads Branch at NASA Langley Research Center [NSG-1321] FX The research of R. Ramakrishnan and E.A. Thornton was supported by research grant NSG-1321 through the Aerothermal Loads Branch at NASA Langley Research Center. NR 15 TC 0 Z9 0 U1 0 U2 0 PU EMERALD GROUP PUBLISHING LIMITED PI BINGLEY PA HOWARD HOUSE, WAGON LANE, BINGLEY BD16 1WA, W YORKSHIRE, ENGLAND SN 0961-5539 J9 INT J NUMER METHOD H JI Int. J. Numer. Methods Heat Fluid Flow PD FEB PY 1992 VL 2 IS 1 BP 517 EP 535 DI 10.1108/eb017509 PG 19 WC Thermodynamics; Mathematics, Interdisciplinary Applications; Mechanics SC Thermodynamics; Mathematics; Mechanics GA V29HK UT WOS:000208739300034 ER PT J AU FRASER, RS FERRARE, RA KAUFMAN, YJ MARKHAM, BL MATTOO, S AF FRASER, RS FERRARE, RA KAUFMAN, YJ MARKHAM, BL MATTOO, S TI ALGORITHM FOR ATMOSPHERIC CORRECTIONS OF AIRCRAFT AND SATELLITE IMAGERY SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID SCALE AIR-POLLUTION; SCATTERING AB An algorithm is described for making fast atmospheric corrections. The required radiation parameters are stored in a lookup table. The procedure is to enter the lookup table with the measured radiance, wavelength, view and illumination directions, heights of observation and surface, and the aerosol and gaseous absorption optical thicknesses. The surface radiance, the irradiance incident on a surface, and surface reflectance are computed then. Alternately, the program will compute the upward radiances at specific altitudes for a given surface reflectance, view and illumination directions, and aerosol and gaseous absorption optical thicknesses. C1 NASA,GODDARD SPACE FLIGHT CTR,TERR PHYS LAB,GREENBELT,MD 20771. APPL RES CORP,LANDOVER,MD 20785. RP FRASER, RS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHER LAB,GREENBELT,MD 20771, USA. RI Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 27 TC 76 Z9 85 U1 0 U2 5 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD FEB PY 1992 VL 13 IS 3 BP 541 EP 557 PG 17 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA HF722 UT WOS:A1992HF72200012 ER PT J AU JACKSON, TJ SCHMUGGE, TJ PARRY, R KUSTAS, WP RITCHIE, JC SHUTKO, AM HALDIN, A REUTOV, E NOVICHIKHIN, E LIBERMAN, B SHIUE, JC DAVIS, MR GOODRICH, DC AMER, SB BACH, LB AF JACKSON, TJ SCHMUGGE, TJ PARRY, R KUSTAS, WP RITCHIE, JC SHUTKO, AM HALDIN, A REUTOV, E NOVICHIKHIN, E LIBERMAN, B SHIUE, JC DAVIS, MR GOODRICH, DC AMER, SB BACH, LB TI MULTIFREQUENCY PASSIVE MICROWAVE OBSERVATIONS OF SOIL-MOISTURE IN AN ARID RANGELAND ENVIRONMENT SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article AB A cooperative experiment was conducted by teams from the U.S. and U.S.S.R. to evaluate passive microwave instruments and algorithms used to estimate surface soil moisture. Experiments were conducted as part of an interdisciplinary experiment in an arid rangeland watershed located in the southwest United States. Soviet microwave radiometers operating at wavelengths of 2.25, 21 and 27 cm were flown on a U.S. aircraft. Radio frequency interference limited usable data to the 2.25 and 21 cm systems. Data have been calibrated and compared to ground observations of soil moisture. These analyses showed that the 21 cm system could produce reliable and useful soil moisture information and that the 2.25 cm system was of no value for soil moisture estimation in this experiment. C1 ACAD SCI USSR,INST RADIOENGN & ELECTR,MOSCOW V-71,USSR. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. USDA ARS,ARIDLAND WATERSHED MANAGEMENT RES UNIT,TUCSON,AZ. RP JACKSON, TJ (reprint author), USDA ARS,BELTSVILLE AGR RES CTR,HYDROL LAB,BELTSVILLE,MD 20705, USA. RI Goodrich, David/B-1763-2009 OI Goodrich, David/0000-0001-7735-1448 NR 7 TC 9 Z9 9 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD FEB PY 1992 VL 13 IS 3 BP 573 EP 580 PG 8 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA HF722 UT WOS:A1992HF72200014 ER PT J AU ZAK, M AF ZAK, M TI THE PROBLEM OF IRREVERSIBILITY IN NEWTONIAN DYNAMICS SO INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS LA English DT Article AB A new type of dissipation function which does not satisfy the Lipschitz condition at equilibrium states is proposed. It is shown that Newtonian dynamics supplemented by this dissipation function becomes irreversible, i.e., it is not invariant with respect to time inversion. Some effects associated with the approaching of equilibria in infinite time are eliminated. New meanings of chaos and turbulence are discussed. RP ZAK, M (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109, USA. NR 7 TC 8 Z9 8 U1 1 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0020-7748 J9 INT J THEOR PHYS JI Int. J. Theor. Phys. PD FEB PY 1992 VL 31 IS 2 BP 333 EP 342 DI 10.1007/BF00673265 PG 10 WC Physics, Multidisciplinary SC Physics GA HG222 UT WOS:A1992HG22200015 ER PT J AU ALBIN, S SATIRA, JD LIVINGSTON, DL SHULL, TA AF ALBIN, S SATIRA, JD LIVINGSTON, DL SHULL, TA TI STIMULATED ELECTRONIC-TRANSITION CONCEPT FOR AN ERASABLE OPTICAL MEMORY SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article; Proceedings Paper CT 1991 INTERNATIONAL SYMP ON OPTICAL MEMORY ( ISOM 91 ) CY OCT 04, 1991 CL SAPPORO, JAPAN SP JAPAN SOC APPL PHYS, INST ELECTR, INFORMAT & COMMUN ENGINEERS, MAGNET SOC JAPAN, OPTOELECTR IND & TECHNOL DEV ASSOC DE OPTICAL MEMORY; PHOTOLUMINESCENCE; STIMULATED EMISSION; STORAGE TIME; CHARGE DECAY; TUNNELING; NEURAL NETWORK ID MGS; PHOSPHORS; IONS AB A new concept for an erasable optical memory is demonstrated using stimulated electronic transition (SET). Large bandgap semiconductors are suitable materials for the SET medium. We have investigated the properties of MgS:Eu, Sm and SrS:Eu, Sm as possible media for the SET process. Quantum storage is achieved in the form of charges in deep levels in the medium and stimulated radiative recombination is used as the reading process. Unlike magneto-optic (M-O) and phase change (PC) processes, optical writing, reading and erasing are achieved without localized heating. The SET process will have an inherently faster data transfer rate and a higher storage density, and the medium will be more durable than the M-O and PC media. A possible application of the SET process in neural networks is also discussed. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP ALBIN, S (reprint author), OLD DOMINION UNIV,DEPT ELECT & COMP ENGN,NORFOLK,VA 23529, USA. NR 13 TC 20 Z9 20 U1 0 U2 1 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Short Notes Rev. Pap. PD FEB PY 1992 VL 31 IS 2B BP 715 EP 719 DI 10.1143/JJAP.31.715 PG 5 WC Physics, Applied SC Physics GA HL578 UT WOS:A1992HL57800064 ER PT J AU ARGENTINI, S WETZEL, PJ KARYAMPUDI, VM AF ARGENTINI, S WETZEL, PJ KARYAMPUDI, VM TI TESTING A DETAILED BIOPHYSICAL PARAMETERIZATION FOR LAND AIR EXCHANGE IN A HIGH-RESOLUTION BOUNDARY-LAYER MODEL SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID GROUND SURFACE-TEMPERATURE; MESOSCALE CIRCULATIONS; NUMERICAL SIMULATIONS; MIXED-LAYER; SOIL; EVAPOTRANSPIRATION; VEGETATION; MOISTURE; PREDICTION; IMPACT AB In order to properly model the influence of land surface properties on mesoscale atmospheric phenomena, it is important to include physically realistic parameterizations of major biophysical processes involved. The primary influence of the surface on the atmosphere occurs via its control of the surface energy budget and the consequent turbulent exchange with the planetary boundary layer (PBL). The physical parameterization of the complex surface processes may not be confidently incorporated into a three-dimensional model without first undergoing testing in a simpler, more controlled setting. It has been accepted practice to first validate the parameterization in a one-dimensional version of the intended parent model. The purposes of this paper are to present the results of such a validation and to provide deeper insight into a key aspect of the parameterization by presenting some sensitivity tests involving the leaf stomatal control of water vapor flux. The performance of the new parameterization in the parent model is compared to three different observational datasets characterized by widely different surface and vegetation conditions; the individual fluxes from the new model are found to simulate the observations well and to be a significant improvement compared to the predicted fluxes from the original model. Last, the values of latent heat flux, obtained using two independent stomatal resistance formulations, are compared. For the three experimental datasets studied, the difference in predicted latent heat flux between the two formulations is less than 10 W m-2 at all times. Although sensitivity tests showed greater differences under certain circumstances, it is concluded that most of the biophysical controls that enter into the stomatal resistance formulation, but defy simple field measurements, do not need to be specified with great accuracy in order to produce a prediction of latent heat flux that falls within the envelope of usual observational error. C1 NASA,GODDARD SPACE FLIGHT CTR,SEVERE STORMS BRANCH,ATMOSPHERES LAB,CODE 912,GREENBELT,MD 20771. CNR,IST FIS ATMOSFERA,I-00044 FRASCATI,ITALY. UNIV SPACE RES ASSOC,GREENBELT,MD 20771. OI ARGENTINI, STEFANIA/0000-0002-7939-0309 NR 38 TC 8 Z9 8 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD FEB PY 1992 VL 31 IS 2 BP 142 EP 156 DI 10.1175/1520-0450(1992)031<0142:TADBPF>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HE943 UT WOS:A1992HE94300002 ER PT J AU GIBSON, BC WILLIAMS, JR FROMHOLD, AT BOZACK, MJ NEELY, WC WHITAKER, AF AF GIBSON, BC WILLIAMS, JR FROMHOLD, AT BOZACK, MJ NEELY, WC WHITAKER, AF TI THE INTERACTION OF ATOMIC OXYGEN WITH THIN COPPER-FILMS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID OXIDATION; PLASMA; OXIDE AB A source of thermal, ground-state atomic oxygen has been used to expose thin copper films at a flux of 1.4 x 10(17) atoms/cm2 s for times up to 50 min for each of five temperatures between 140 and 200-degrees-C. Rutherford backscattering spectroscopy was used to characterize the oxide formed during exposure. The observations are consistent with the oxide phase Cu2O. The time dependence and the temperature dependence of the oxide layer thickness can be described using oxide film growth theory based on rate limitation by diffusion. Within the time and temperature ranges of this study, the growth of the oxide layers is well described by the equation L(T,t) = 3.6 x 10(8) exp(- 1.1/2k(B)T)t1/2, where L, T, and t are measured in angstroms, degrees Kelvin, and minutes, respectively. The deduced activation energy is 1.10 +/- 0.15 eV, with the attendant oxidation rate being greater than that for the corresponding reaction in molecular oxygen. C1 AUBURN UNIV, DEPT PHYS, AUBURN, AL 36849 USA. AUBURN UNIV, DEPT CHEM, AUBURN, AL 36849 USA. NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, DIV ENGN PHYS, HUNTSVILLE, AL 35812 USA. NR 28 TC 6 Z9 7 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 1 PY 1992 VL 96 IS 3 BP 2318 EP 2323 DI 10.1063/1.462028 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HC610 UT WOS:A1992HC61000071 ER PT J AU LAU, KM PENG, L AF LAU, KM PENG, L TI DYNAMICS OF ATMOSPHERIC TELECONNECTIONS DURING THE NORTHERN SUMMER SO JOURNAL OF CLIMATE LA English DT Article ID CIRCULATION; PROPAGATION; PACIFIC; CLIMATE; MODELS AB In this paper, the mechanisms of northern summertime teleconnections are investigated using a barotropic model. In a series of numerical experiments we study the atmospheric response over the eastern Pacific-North America to an idealized local divergence source corresponding to the northward displacement of the ITCZ in the eastern Pacific. It is found that the response is much stronger in June than in May and is strongest when the forcing is located north of about 10-degrees-N. This can be explained in terms of the refractive properties of the climatological summertime subtropical jet stream over North America. In another series of experiments we examine the global response as a function of the longitudinal location of the tropical forcing. A wave train emanating from the subtropics of the western Pacific near the Philippines, arching across the Aleutians and the Gulf of Alaska, and terminating with a high anomaly over the continental United States appears over a wide longitudinal range of local forcing, suggesting the existence of a normal mode for the northern summertime climatological flow. The normal-mode concept is supported by further experiments using extratropical forcings as well as free-mode integrations. The upstream anomalous low over the Gulf of Alaska is found to be essential for the development of the anomalous high over the continental United States. These results indicate that an above-normal high over the continent may occur when the anomalous forcing (both tropical and extratropical) acts to amplify the normal-mode structure. The caveats and implications of the present results to the possible linkage between tropical forcing and United States droughts are also discussed. C1 NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. RP LAU, KM (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,CODE 913,GREENBELT,MD 20771, USA. RI Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 16 TC 48 Z9 52 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD FEB PY 1992 VL 5 IS 2 BP 140 EP 158 DI 10.1175/1520-0442(1992)005<0140:DOATDT>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HP485 UT WOS:A1992HP48500003 ER PT J AU CHEUNG, BSK MONEY, KE KOHL, RL KINTER, LB AF CHEUNG, BSK MONEY, KE KOHL, RL KINTER, LB TI INVESTIGATION OF ANTI-MOTION SICKNESS DRUGS IN THE SQUIRREL-MONKEY SO JOURNAL OF CLINICAL PHARMACOLOGY LA English DT Article ID CINNARIZINE; REFLEX AB Early attempts to develop an animal model for anti-motion sickness drugs, using dogs and cats, were unsuccessful. Dogs did not show a beneficial effect of scopolamine (probably the best single anti-motion sickness drug for humans thus far) and the findings in cats were not definitive. The authors have developed an animal model using the squirrel monkey (Saimiri sciureus) of the Bolivian phenotype. Unrestrained monkeys in a small lucite cage were tested in an apparatus that induces motion sickness by combining vertical oscillation and horizontal rotation in a visually unrestricted laboratory environment. Signs of motion sickness were scored using a rating scale. Ten susceptible monkeys (weighing 800-1000 g) were given a total of five tests each, to establish the baseline susceptibility level. Based on the anticholinergic activity of scopolamine, the sensitivity of squirrel monkey to scopolamine was investigated, and the appropriate dose of scopolamine for this species was determined. Then various anti-motion sickness preparations were administered in subsequent tests: 100 ug scopolamine per monkey; 140 ug dexedrine; 50 ug scopolamine plus 70 ug dexedrine; 100 ug scopolamine plus 140 ug dexedrine; 3 mg promethazine; 3 mg promethazine plus 3 mg ephedrine. All these preparations were significantly effective in preventing motion sickness in the monkeys. Ephedrine, by itself, which is marginally effective in humans, was ineffective in the monkeys at the doses tried (0.3-6.0 mg). The squirrel monkey appears to be a good animal model for antimotion sickness drugs. Peripherally acting antihistamines such as astemizole and terfenadine were found to be ineffective, whereas flunarizine, and an arginine vasopressin V1 antagonist, showed significant activity in preventing motion sickness. C1 NASA,LYNDON B JOHNSON SPACE CTR,SPACE BIOMED RES INST,HOUSTON,TX 77058. SMITHKLINE BEECHAM LABS,DEPT INVEST TOXICOL,KING OF PRUSSIA,PA. RP CHEUNG, BSK (reprint author), DEF & CIVIL INST ENVIRONM MED,POB 2000,TORONTO M3M 3B9,ONTARIO,CANADA. NR 29 TC 14 Z9 16 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0091-2700 J9 J CLIN PHARMACOL JI J. Clin. Pharmacol. PD FEB PY 1992 VL 32 IS 2 BP 163 EP 175 PG 13 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA HC997 UT WOS:A1992HC99700010 PM 1613127 ER PT J AU NOOR, AK PETERS, JM AF NOOR, AK PETERS, JM TI THERMOMECHANICAL BUCKLING OF MULTILAYERED COMPOSITE PLATES SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article AB A study is made of the thermomechanical buckling of composite plates subjected to combined thermal and axial loadings. The plates considered consist of a number of perfectly bonded layers and have symmetric lamination with respect to the middle plane. The material properties are assumed to be independent of temperature. The analysis is based on a first-order shear deformation theory. A mixed formulation is used, with the fundamental unknowns consisting of the generalized displacements and the stress resultants of the plate. An efficient multiple-parameter reduction method is used, in conjunction with mixed finite-element models, for determining the stability boundary of the plate. Sensitivity derivatives are evaluated and used to study the sensitivity of the buckling response to variations in different lamination and material parameters of the plate. Numerical results are presented that show the effectiveness of the reduction method, as well as the effects of variations in the material characteristics and fiber orientation of individual layers on the stability boundary of the plate. RP NOOR, AK (reprint author), UNIV VIRGINIA,NASA LANGLEY RES CTR,CTR COMP STRUCT TECH,HAMPTON,VA 23665, USA. NR 17 TC 22 Z9 24 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD FEB PY 1992 VL 118 IS 2 BP 351 EP 366 DI 10.1061/(ASCE)0733-9399(1992)118:2(351) PG 16 WC Engineering, Mechanical SC Engineering GA HA491 UT WOS:A1992HA49100008 ER PT J AU MAEKAWA, H MANSOUR, NN BUELL, JC AF MAEKAWA, H MANSOUR, NN BUELL, JC TI INSTABILITY MODE INTERACTIONS IN A SPATIALLY DEVELOPING PLANE WAKE SO JOURNAL OF FLUID MECHANICS LA English DT Article ID 2-DIMENSIONAL WAKE; FLOWS; TRANSITION; EVOLUTION; STABILITY AB The transition mechanism in a spatially developing two-dimensional wake is studied by means of direct numerical simulations. Five different types of forcing of the inlet are investigated: fundamental mode, fundamental and one or two subharmonics, fundamental mode and random noise, and random noise only. The effects of the amplitude levels of the perturbations on the development of the layer are also investigated. Statistical analyses are performed and some numerical results are compared with experimental measurements. When only a fundamental mode is forced, the energy spectra show amplification of the fundamental frequency and its higher harmonics, and the development of a stable vortex street. When the inlet flow is forced by a fundamental mode and two subharmonics, a vortex street also appears downstream, but the shape of the vortices is distorted. The amplitude of the subharmonic grows only after the saturation of the fundamental. Amplification of modes close to the fundamental mode is observed when random noise of large amplitude is added to the fundamental mode. The phase jitter around the fundamental frequency plays a critical role in generating vortices of random shape and spacing. Large- and small-scale distortions of the flow structure are observed. Pairing of vortices of the same sign is observed, as well as coupling of vortices of opposite sign. When the inlet profile is forced by random noise of amplitude 10(-5) times the free-stream velocity, one frequency close to the most unstable one is amplified more than the others. The energy spectrum is otherwise full. When the same low amplitude (10(-5)) is used to force the fundamental mode and its two subharmonics, bands of energy develop around the forced modes and their harmonics. Finally, we find that large-deficit wakes are globally unstable when the size of the absolutely unstable region is greater than about three times the half-width of the wake C1 KAGOSHIMA UNIV,DEPT MECH ENGN,KAGOSHIMA 890,JAPAN. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 24 TC 13 Z9 13 U1 0 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD FEB PY 1992 VL 235 BP 223 EP 254 DI 10.1017/S0022112092001095 PG 32 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA HF765 UT WOS:A1992HF76500010 ER PT J AU BATCHELOR, GK CANUTO, VM CHASNOV, JR AF BATCHELOR, GK CANUTO, VM CHASNOV, JR TI HOMOGENEOUS BUOYANCY-GENERATED TURBULENCE SO JOURNAL OF FLUID MECHANICS LA English DT Article ID ISOTROPIC TURBULENCE AB We consider the statistically homogeneous motion that is generated by buoyancy forces after the creation of homogeneous random fluctuations in the density of infinite fluid at an initial instant. The mean density is uniform, and density fluctuations are smoothed by molecular diffusion. This turbulent flow system has interesting properties, and shows how self-generated motion contributes to the rate of mixing of an 'active' scalar contaminant. If nonlinear terms in the governing equations are negligible, there is an exact solution which shows that the history of the motion depends crucially on the form of the buoyancy spectrum near zero wavenumber magnitude (kappa). According to this solution the Reynolds number of the motion increases indefinitely, so the linear equations do not remain valid. There are indications of similar behaviour when the nonlinear terms are retained. The value of the three-dimensional buoyancy spectrum function at kappa = 0 is shown to be independent of time, and this points to the existence of a similarity state of turbulence with decreasing mean-square velocity but increasing Reynolds number at large times. We have made a numerical simulation of the flow field and have obtained the mean-square velocity and density fluctuations and the associated spectra as functions of time for various initial conditions. An estimate of the time required for the mean-square density fluctuation to fall to a specified small value is found. The expected similarity state at large times is confirmed by the numerical simulation, and there are indications of a second similarity state which develops asymptotically when the buoyancy spectrum is zero at kappa = 0. The analytical and numerical results together give a comprehensive description of the birth, life and lingering death of buoyancy-generated turbulence. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP BATCHELOR, GK (reprint author), UNIV CAMBRIDGE,DEPT APPL MATH & THEORET PHYS,SILVER ST,CAMBRIDGE CB3 9EW,ENGLAND. NR 11 TC 45 Z9 45 U1 1 U2 4 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD FEB PY 1992 VL 235 BP 349 EP & DI 10.1017/S0022112092001149 PG 0 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA HF765 UT WOS:A1992HF76500015 ER PT J AU CARPENTER, DL SMITH, AJ GILES, BL CHAPPELL, CR DECREAU, PME AF CARPENTER, DL SMITH, AJ GILES, BL CHAPPELL, CR DECREAU, PME TI A CASE-STUDY OF PLASMA STRUCTURE IN THE DUSK SECTOR ASSOCIATED WITH ENHANCED MAGNETOSPHERIC CONVECTION SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT WORKSHOP ON PLASMASPHERE REFILLING CY OCT 15-16, 1990 CL UNIV ALABAMA, HUNTSVILLE, AL HO UNIV ALABAMA ID ELECTRIC-FIELD; WHISTLERS; DYNAMICS; DENSITY; GEOS-2 AB In a case study from June 8-9, 1982, data from ground whistler stations Siple and Halley, Antaretica, located at L approximately 4.3 and spaced by approximately 2 hours in MLT, and from satellites DE 1 and GEOS 2, have provided confirming evidence that the bulge region of the magnetosphere can exhibit an abrupt westward "edge," as reported earlier from whistlers. The present data and previous MHD modeling work suggest that this distinctive feature develops during periods of steady or declining substorm activity, when dense plasma previously carried sunward under the influence of enhanced convection activity begins to rotate with the Harth at angular velocities that decrease with increasing L value and becomes spirallike in form. For the first time, whistler data have been used to identify a narrow dense plasma feature, separated from the main plasmasphere and extending sunward into the late afternoon sector at L values near the outer observed limits of the main plasmaphere bulge. The westward edge of the main bulge, found by both whistler stations to be at approximately 1800 MLT, appeared to be quasi-stationary in Sun-Earth coordinates during the prevailing conditions of gradually declining geomagnetic agitation. It is possible that outlying dense plasma features such as the one observed develop as part of the process leading to the occurrence of the more readily detectable abrupt westward edge of the bulge. It was not possible in this case to determine the extent to which the outlying feature was smoothly attached to or isolated from the main bulge region. C1 NERC,BRITISH ANTARCTIC SURV,CAMBRIDGE CB3 0ET,ENGLAND. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812. LAB PHYS & CHIM ENVIRONM,CNRS,F-45071 ORLEANS 02,FRANCE. RP CARPENTER, DL (reprint author), STANFORD UNIV,DEPT ELECT ENGN,STAR LAB,STANFORD,CA 94305, USA. NR 46 TC 26 Z9 26 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1992 VL 97 IS A2 BP 1157 EP 1166 DI 10.1029/91JA01546 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB870 UT WOS:A1992HB87000009 ER PT J AU SOJKA, JJ BOWLINE, M SCHUNK, RW CRAVEN, JD FRANK, LA SHARBER, JR WINNINGHAM, JD BRACE, LH AF SOJKA, JJ BOWLINE, M SCHUNK, RW CRAVEN, JD FRANK, LA SHARBER, JR WINNINGHAM, JD BRACE, LH TI IONOSPHERIC SIMULATION COMPARED WITH DYNAMICS EXPLORER OBSERVATIONS FOR NOVEMBER 22, 1981 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT WORKSHOP ON PLASMASPHERE REFILLING CY OCT 15-16, 1990 CL UNIV ALABAMA, HUNTSVILLE, AL HO UNIV ALABAMA ID MAGNETOSPHERIC STORM INPUTS; MILLSTONE HILL OBSERVATIONS; CONVECTION ELECTRIC-FIELD; LOW MAGNETIC ACTIVITY; F-REGION; POLAR-CAP; MODEL; DENSITIES; THERMOSPHERE; PATCHES AB Dynamics Explorer (DE) 2 electric field and particle data have been used to constrain the inputs of a time-dependent ionospheric model (TDIM) for a simulation of the ionosphere on November 22, 1981. The simulated densities have then been critically compared with the DE 2 electron density observations. This comparison uncovers a model-data disagreement in the moming sector trough, generally good agreement of the background density in the polar cap and evening sector trough, and a difficulty in modelling the observed polar F layer patches. From this comparison, the consequences of structure in the electric field and precipitation inputs can be seen. This is further highlighted during a substorm period for which DE 1 auroral images were available. Using these images, a revised dynamic particle precipitation pattern was used in the ionospheric model; the resulting densities were different from the original simulation. With this revised dynamic precipitation model, improved density agreement is obtained in the auroral/polar regions where the plasma convection is not stagnant. However, the dynamic study also reveals a difficulty of matching dynamic auroral patterns with static empirical convection patterns. In this case, the matching of the models produced intense auroral precipitation in a stagnation region, which, in turn, led to exceedingly large TDIM densities. C1 UNIV IOWA,DEPT PHYS & ASTRON,IOWA CITY,IA 52242. SW RES INST,SAN ANTONIO,TX 78184. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP SOJKA, JJ (reprint author), UTAH STATE UNIV,CTR ATMOSPHER & SPACE SCI,LOGAN,UT 84322, USA. NR 37 TC 4 Z9 4 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1992 VL 97 IS A2 BP 1245 EP 1256 DI 10.1029/91JA02215 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB870 UT WOS:A1992HB87000015 ER PT J AU GARBE, GP ARNOLDY, RL MOORE, TE KINTNER, PM VAGO, JL AF GARBE, GP ARNOLDY, RL MOORE, TE KINTNER, PM VAGO, JL TI OBSERVATIONS OF TRANSVERSE ION-ACCELERATION IN THE TOPSIDE AURORAL IONOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT WORKSHOP ON PLASMASPHERE REFILLING CY OCT 15-16, 1990 CL UNIV ALABAMA, HUNTSVILLE, AL HO UNIV ALABAMA ID OBLIQUE DOUBLE-LAYERS; FIELD LINES; CYCLOTRON RESONANCE; SUPRAURORAL REGION; BEAM INSTABILITIES; PLASMA-WAVES; HEAVY-IONS; CONICS; ZONE AB Data obtained from a sounding rocket flight which reached an apogee of 927 km and passed through several auroral arcs are reported. Thermal/superthermal ions were sampled by charged particle analyzers which allowed for a rapid (almost-equal-to 1 s) sampling of their distribution function. During portions of the flight when the rocket was not in an energetic auroral structure, the ion data are fit to a Maxwellian function which yields the plasma parameters. Throughout the middle portion of the flight when above 700 km altitude, ion distributions having a superthermal tail were measured. These ion distributions generally coexisted with a cold thermal core distribution and peaked at pitch angles slightly greater than 90-degrees, which identifies them as conic distributions. These ions can be modeled using a bi-Maxwellian distribution function with a perpendicular (to B) temperature about 10 times greater than the parallel temperature of 0.15 eV. When the rocket was immersed in energetic auroral electron precipitation, two other ion distributions were observed. Transversely accelerated ions which represented bulk heating of the ambient population were observed continuously in these arcs. The characteristic perpendicular energy of the transversely bulk heated ions reached as high as 3 eV compared to typically less than 0.4 eV during nonauroral times. Cold ions flowing down the magnetic field were also continuously observed when the rocket was immersed in auroral electron precipitation and had downward speeds between 3 and 5 km/s. If one balances electric and collisional forces, these speeds translate to an electric field pointing into the atmosphere of magnitude 0.01 mV/m. A close correlation between auroral electron precipitation, measured electrostatic oxygen cyclotron waves, cold downflowing ions and transversely bulk heated ions will be shown. In addition, the ion distributions with a superthermal tail are seen to have a loose correlation with the aurora and measured H+ gyroharmonic wave structures. These observations are discussed in terms of some current theories of transverse ion energization. C1 UNIV NEW HAMPSHIRE,INST STUDY EARTH OCEAN & SPACE,DURHAM,NH 03824. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812. CORNELL UNIV,SCH ELECT ENGN,ITHACA,NY 14853. RI Moore, Thomas/D-4675-2012 OI Moore, Thomas/0000-0002-3150-1137 NR 39 TC 18 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1992 VL 97 IS A2 BP 1257 EP 1269 DI 10.1029/91JA02127 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB870 UT WOS:A1992HB87000016 ER PT J AU FAIRFIELD, DH AF FAIRFIELD, DH TI ON THE STRUCTURE OF THE DISTANT MAGNETOTAIL - ISEE-3 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT WORKSHOP ON PLASMASPHERE REFILLING CY OCT 15-16, 1990 CL UNIV ALABAMA, HUNTSVILLE, AL HO UNIV ALABAMA ID GEOMAGNETIC TAIL; LUNAR DISTANCE; AVERAGE; PLASMA AB ISEE 3 magnetic field and electron plasma data have been used to determine the relative frequency of observation of the magnetoschcath and magnetotail in the region where a nominal magnetotail is expected. These observations have been compared with how frequently a tail of a given radius would be expected to be seen, assuming typical variations in the direction of the solar wind flow relative to the radial. Observations match expectations if the average radius of the distant magnetotail is 24 R(E). This relatively small radius is consistent with an open magnetotail where field lines are lost both through the magnetopause and also by closing across the equatorial current sheet. Further evidence suggests that the distant tail is seen somewhat less frequently during geomagnetically quiet periods which may mean that the radius is smaller during such conditions. The average solar magnetospheric B(x) component of the field in the distant plasma sheet is 0.6 nT during quiet times but zero during disturbed times. The observation suggests that when the polar cap becomes smaller during quiet times, many of the field lines that previously formed the distant tail lobes are converted into closed field lines that cross the equatorial plane earthward of 240 R(E). Further indications are that the east-west dimension may exceed the north-south dimension. The lobe is observed 4.5 times as often as the plasma sheet, implying an average half thickness of the distant plasma sheet of 3.4 R(E). RP FAIRFIELD, DH (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771, USA. NR 19 TC 37 Z9 37 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1992 VL 97 IS A2 BP 1403 EP 1410 DI 10.1029/91JA02388 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB870 UT WOS:A1992HB87000030 ER PT J AU HUANG, TS BIRMINGHAM, TJ AF HUANG, TS BIRMINGHAM, TJ TI THE POLARIZATION ELECTRIC-FIELD AND ITS EFFECTS IN AN ANISOTROPIC ROTATING MAGNETOSPHERIC PLASMA SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SATURNS MAGNETOSPHERE; VOYAGER; TORUS; IONS AB Spatial variations of density and temperature along a magnetic field line are evaluated for a plasma undergoing adiabatic motion in a rotating magnetosphere. The effects of centrifugal and gravitational forces are accounted for, as is anisotropy in the pitch angle distribution functions of individual species. A polarization electric field is invoked to eliminate the net electric charge density resulting from the aforementioned mass dependent forces and different anisotropies. The position of maximum density in a two-component, electron-ion plasma is determined both in the absence and in the presence of the polarization effect and compared. A scale height, generalized to include anisotropies, is derived for the density fall-off. The polarization electric field is also included in the parallel guiding center equation; equilibrium points are determined and compared in both individual and average senses with the position of density maximum. Finally a transverse (to magnetic field lines) electric component is deduced as a consequence of dissimilar charge neutralization on adjacent field lines. The E x B velocity resultant from such a "fringing" electric field is calculated and compared with the magnitude of other drifts. RP HUANG, TS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771, USA. NR 12 TC 34 Z9 34 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1992 VL 97 IS A2 BP 1511 EP 1519 DI 10.1029/91JA02611 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB870 UT WOS:A1992HB87000038 ER PT J AU MCDONALD, FB MORAAL, H REINECKE, JPL LAL, N MCGUIRE, RE AF MCDONALD, FB MORAAL, H REINECKE, JPL LAL, N MCGUIRE, RE TI THE COSMIC-RADIATION IN THE HELIOSPHERE AT SUCCESSIVE SOLAR MINIMA SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID OUTER HELIOSPHERE; CURRENT SHEET; ANOMALOUS HELIUM; SECTOR STRUCTURE; RAY MODULATION; GRADIENTS; CYCLE; DRIFT; TRANSPORT; SHOCK AB Comparative cosmic ray studies at the time of successive solar minima are of special importance in establishing the relative role of large-scale drift effects in the modulation process and in estimating the size of the modulation region and the local interstellar spectra of low- and medium-energy cosmic rays. In this paper the 1 AU cosmic ray observations are compared for the last three solar minimum periods along with the 1977/1978 and 1987 Pioneer 10 and Voyager 1 and 2 data from the outer heliosphere. There is good agreement between the 1965 and 1987 galactic cosmic ray H and He spectra at 1 AU. However, there are significant and complex differences between the 1977/1978 and 1987 measurements of the galactic and anomalous cosmic ray components at 1 and 15 AU. In the outer heliosphere there are large negative latitudinal gradients that reach their maximum magnitude when the inclination of the outer heliosphere current sheet is at a minimum. The radial gradients decrease with heliocentric distance as approximately 1/r0.7 and do not differ significantly at the successive solar minima. While these effects, along with the shift in the intensity maximum of anomalous helium (He+), are in the direction expected from large-scale gradient and curvature drifts in the heliosphere, they are about an order of magnitude smaller than those calculated using the standard Parker model of the interplanetary magnetic field. The measured radial and latitudinal gradients are used to estimate the particle transport parameters in the outer heliosphere. The slope of the H spectra measured at Pioneer 10 for both solar minimum periods is given by gamma(II) approximately 0.5 down to energies of 40 McV. Using the local interstellar He spectrum of Webber et al. (1987), it is estimated that the modulation boundary is of the order of 160 AU. C1 NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,NATL SPACE SCIENCE DATA CTR,GREENBELT,MD 20771. POTCHEFSTROOM UNIV CHRISTIAN HIGHER EDUC,DEPT PHYS,POTCHEFSTROOM 2520,SOUTH AFRICA. RP MCDONALD, FB (reprint author), UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742, USA. NR 51 TC 86 Z9 87 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1992 VL 97 IS A2 BP 1557 EP 1570 DI 10.1029/91JA02389 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB870 UT WOS:A1992HB87000043 ER PT J AU OWEN, CJ COWLEY, SWH AF OWEN, CJ COWLEY, SWH TI COMMENT ON OWEN AND COWLEY ANALYSIS OF IMPULSIVE PLASMA TRANSPORT THROUGH THE MAGNETOPAUSE - COMMENT SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Note C1 UNIV LONDON IMPERIAL COLL SCI & TECHNOL,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. RP OWEN, CJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,CODE 696,GREENBELT,MD 20771, USA. RI Owen, Christopher/C-2999-2008 OI Owen, Christopher/0000-0002-5982-4667 NR 5 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1992 VL 97 IS A2 BP 1641 EP 1643 DI 10.1029/91JA02442 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HB870 UT WOS:A1992HB87000051 ER PT J AU TAYLOR, GR JANNEY, RP AF TAYLOR, GR JANNEY, RP TI INVIVO TESTING CONFIRMS A BLUNTING OF THE HUMAN CELL-MEDIATED IMMUNE MECHANISM DURING SPACE-FLIGHT SO JOURNAL OF LEUKOCYTE BIOLOGY LA English DT Article DE DELAYED-TYPE HYPERSENSITIVITY; MULTITEST CMI; IMMUNOSUPPRESSION; SKIN TESTING; SPACE FLIGHT ID DELAYED CUTANEOUS HYPERSENSITIVITY; MULTITEST CMI; NORMAL VALUES; SPACEFLIGHT; INTERFERON; VOLUNTEERS; ANTIGENS; SHUTTLE; ADULTS AB The cell-mediated immune (CMI) mechanism was evaluated in 10 space shuttle astronauts by measuring their delayed-type hypersensitivity response to seven common recall antigens. The Multitest CMI test system was used to administer antigens of tetanus, diphtheria, Streptococcus, Proteus, old tuberculin, Candida, and Trichophyton to the forearm 46 h before nominal mission termination; readings were conducted 2 h after landing. The mean number of reactions was reduced from 4.5 preflight to 3.0 inflight, and the mean reaction score was reduced from 21.4 to 13.7 mm inflight. The data presented suggest that the CMI system is still being degraded by space flight conditions on day 4 and that between day 5 and day 10, the depression maximizes and the system begins to adjust to the new conditions. The relation of these in vivo findings to previously reported in vitro results is discussed. C1 KRUG LIFE SCI,LB JOHNSON SPACE CTR,SPACE BIOMED RES INST,HOUSTON,TX. KRUG LIFE SCI,SPACE STN SCI OFF,HOUSTON,TX. NR 25 TC 93 Z9 95 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0741-5400 J9 J LEUKOCYTE BIOL JI J. Leukoc. Biol. PD FEB PY 1992 VL 51 IS 2 BP 129 EP 132 PG 4 WC Cell Biology; Hematology; Immunology SC Cell Biology; Hematology; Immunology GA JQ362 UT WOS:A1992JQ36200006 PM 1431548 ER PT J AU PRESTAGE, JD TJOELKER, RL DICK, GJ MALEKI, L AF PRESTAGE, JD TJOELKER, RL DICK, GJ MALEKI, L TI ULTRA-STABLE HG+ TRAPPED ION FREQUENCY STANDARD SO JOURNAL OF MODERN OPTICS LA English DT Article ID CLOCK AB We report the development of a fieldable frequency standard based on Hg-199+ ions confined in a hybrid r.f./dc linear ion trap. This trap permits storage of large numbers of ions with reduced susceptibility to the second-order Doppler effect caused by the r.f. confining fields. A 160 mHz wide atomic resonance line for the 40.5 GHz clock transition is used to steer the output of a 5 MHz crystal oscillator to obtain a stability of 2 x 10(-15) for 24 000 s averaging times. For longer averaging intervals, measurements are limited by instabilities in available hydrogen maser frequency standards. Measurements with 37 mHz linewidth for the Hg+ clock transition demonstrate that the inherent stability for this frequency standard is at least as good as 1 x 10(-15). RP PRESTAGE, JD (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,BLDG 298,PASADENA,CA 91109, USA. NR 19 TC 28 Z9 29 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD FEB PY 1992 VL 39 IS 2 BP 221 EP 232 DI 10.1080/09500349214550231 PG 12 WC Optics SC Optics GA HJ044 UT WOS:A1992HJ04400002 ER PT J AU MEADOR, MAB MALARIK, DC OLSHAVSKY, MA AF MEADOR, MAB MALARIK, DC OLSHAVSKY, MA TI PROCESSING STUDIES AND THERMAL-STABILITY OF ADDITION POLYMERS FROM 1,4,5,8-TETRAHYDRO-1,4-5,8-DIEPOXYANTHRACENE AND BIS-DIENES SO JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY LA English DT Article DE HIGH TEMPERATURE POLYMERS; ADDITION POLYMERS; THERMAL STABILITY; POLYMER MATRIX COMPOSITES; POLYIMIDES ID POLYIMIDE AB 1,4,5,8-Tetrahydro-1,4;5,8-diepoxyanthracene reacts with various anthracene end-capped polyimide oligomers to form Diels-Alder cycloaddition copolymers. The polymers are soluble in common organic solvents, and dehydrate thermally at temperatures of 300-350-degrees-C to give thermal oxidatively stable pentiptycene units along the polymer backbone. Because of their high softening points and good thermal oxidative stability, the polymers are candidates for matrix resins for high temperature composite applications. To assess their usefulness for such applications, several parameters have been studied affecting the properties of the final polymer. These parameters include varying the formulated molecular weight of the end-capped prepolymers, and use of meta-substituted aromatic diamine in place of some of the para-substituted diamine. Processability of the resins was studied using rheometric spectrometry, and a processing scheme was devised. Finally, several formulations of neat resins were compression molded into coupons, and evaluated for long-term stability in air at 315 and 371-degrees-C. The best combination of good processability and thermal oxidative stability was obtained from polymers synthesized with small amounts of meta-diamine substitution and higher formulated molecular weight prepolymers. C1 CASE WESTERN RESERVE UNIV,CLEVELAND,OH 44106. RP MEADOR, MAB (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. OI Meador, Mary Ann/0000-0003-2513-7372 NR 10 TC 3 Z9 3 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-624X J9 J POLYM SCI POL CHEM JI J. Polym. Sci. Pol. Chem. PD FEB PY 1992 VL 30 IS 2 BP 305 EP 312 DI 10.1002/pola.1992.080300215 PG 8 WC Polymer Science SC Polymer Science GA HA098 UT WOS:A1992HA09800015 ER PT J AU SLANINA, Z FOX, K KIM, SJ AF SLANINA, Z FOX, K KIM, SJ TI APPLICATION OF THE STOGRYN-HIRSCHFELDER TREATMENT OF WEAK DIMERS TO PLANETARY-ATMOSPHERES SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID CARBON-DIOXIDE; CLUSTERS AB The thermodynamics of carbon dioxide dimerization is treated as an example of the evaluation of weak dimer populations in planetary atmospheres (e.g., Mars and Venus). Two approaches considered are the Stogryn-Hirschfelder treatment using the Lennard-Jones interaction and calculations based on recent quantum chemical data. Several improvements of these treatments are developed. It is indicated that carbon dioxide dimers may be less or more abundant at the surfaces of Mars or Venus, respectively, than is suggested by previous calculations. C1 MAX PLANCK INST CHEM,SAARSTR 23,POSTFACH 3060,W-6500 MAINZ,GERMANY. UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742. NASA,GODDARD SPACE FLIGHT CTR,CTR WORLD DATA,GREENBELT,MD 20771. CZECHOSLOVAK ACAD SCI,J HEYROVSKY INST PHYS CHEM & ELECTROCHEM,CS-18223 PRAGUE 8,CZECHOSLOVAKIA. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. RI Kim, Sang Joon/E-2383-2013 NR 21 TC 10 Z9 10 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD FEB PY 1992 VL 47 IS 2 BP 91 EP 94 DI 10.1016/0022-4073(92)90066-D PG 4 WC Optics; Spectroscopy SC Optics; Spectroscopy GA HD750 UT WOS:A1992HD75000002 ER PT J AU KELLY, JC SHERIF, JS HOPS, J AF KELLY, JC SHERIF, JS HOPS, J TI AN ANALYSIS OF DEFECT DENSITIES FOUND DURING SOFTWARE INSPECTIONS SO JOURNAL OF SYSTEMS AND SOFTWARE LA English DT Article AB Software inspection is a technical evaluation process for finding and removing defects in requirements, design, code, and tests. The Jet Propulsion Laboratory (JPL), California Institute of Technology, tailored Fagan's original process of software inspections to conform to its software development environment in 1987. Detailed data collected from 203 inspections during the first three years of experience at JPL included averages of staff time expended, pages covered, major and minor defects found, and inspection team size. The data were tested for homogeneity. Randomized samples belonging to the various phases or treatments were analyzed using the completely randomized block design analysis of variance (alpha = 0.05). The results showed a significantly higher density of defects during requirements inspections. The number of defect densities decreased exponentially as the work products approached the coding phase because defects were fixed when detected and did not migrate to subsequent phases. This resulted in a relatively flat profile for cost to fix. Increasing the pace of the inspection meeting decreased the density of defects found. This relationship held for major and minor defect densities, although it was more pronounced for minor defects. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. CALIF STATE UNIV FULLERTON,FULLERTON,CA 92634. NR 5 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0164-1212 J9 J SYST SOFTWARE JI J. Syst. Softw. PD FEB PY 1992 VL 17 IS 2 BP 111 EP 117 DI 10.1016/0164-1212(92)90089-3 PG 7 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA HG562 UT WOS:A1992HG56200002 ER PT J AU BHATT, H DONALDSON, KY HASSELMAN, DPH AF BHATT, H DONALDSON, KY HASSELMAN, DPH TI ROLE OF INTERFACIAL CARBON LAYER IN THE THERMAL-DIFFUSIVITY CONDUCTIVITY OF SILICON-CARBIDE FIBER-REINFORCED REACTION-BONDED SILICON-NITRIDE MATRIX COMPOSITES SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PYROLYTIC-GRAPHITE; BARRIER RESISTANCE; BOUNDS AB The role of an interfacial carbon coating in the heat conduction behavior of a uniaxial silicon carbide fiber-reinforced reaction-bonded silicon nitride was investigated. For such a composite without an interfacial carbon coating the values for the thermal conductivity transverse to the fiber direction agreed very well with the values calculated from composite theory using experimental data parallel to the fiber direction, regardless of the ambient atmosphere. However, for a composite made with carbon-coated fibers the experimental values for the thermal conductivity transverse to the fiber direction under vacuum at room temperature were about a factor of 2 lower than those calculated from composite theory assuming perfect interfacial thermal contact. This discrepancy was attributed to the formation of an interfacial gap, resulting from the thermal expansion mismatch between the fibers and the matrix in combination with the low adhesive strength of the carbon coating. In nitrogen or helium the thermal conductivity was found to be higher because of the contribution of gaseous conduction across the interfacial gap. On switching from vacuum to nitrogen a transient effect in the thermal diffusivity was observed, attributed to the diffusion-limited entry of the gas phase into the interfacial gap. These effects decreased with increasing temperature, due to gap closure, to be virtually absent at 1000-degrees-C. C1 NASA,LEWIS RES CTR,CERAM BRANCH,CLEVELAND,OH 44135. RP BHATT, H (reprint author), VIRGINIA POLYTECH INST & STATE UNIV,DEPT MAT ENGN,BLACKSBURG,VA 24061, USA. NR 33 TC 33 Z9 34 U1 3 U2 14 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD FEB PY 1992 VL 75 IS 2 BP 334 EP 340 DI 10.1111/j.1151-2916.1992.tb08183.x PG 7 WC Materials Science, Ceramics SC Materials Science GA HE103 UT WOS:A1992HE10300009 ER PT J AU RAJ, SV PHARR, GM AF RAJ, SV PHARR, GM TI EFFECT OF TEMPERATURE ON THE FORMATION OF CREEP SUBSTRUCTURE IN SODIUM-CHLORIDE SINGLE-CRYSTALS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID 316 STAINLESS-STEEL; DISLOCATION-STRUCTURE; STRESS DEPENDENCE; INTERNAL STRESS; ALUMINUM; METALS; IRON AB The effect of temperature on the formation of creep substructure in sodium chloride single crystals was studied in the temperature range 573 to 873 K. Microstructural observations conducted on polished specimens deformed under a constant value of normalized stress, sigma/G almost-equal-to 4 x 10(-4), where sigma is the applied stress and G is the shear modulus, showed different types of substructural features such as a high density of dislocation etch pits, cells, and subgrains. Detailed measurements of the sizes of the cells and subgrains revealed that the cell size was essentially independent of temperature while the subgrain size increased only by about a factor of 2 for a 300 K increase in temperature. Although the cell and subgrain sizes were not significantly dependent on temperature in comparison to the effect of stress, there was a qualitative change in the substructure morphology with a variation in temperature; i.e., the cells and subgrains were better defined at higher temperatures. The volume fraction of the cell boundaries decreased with increasing temperature, thereby indicating a refinement of the microstructure at the higher temperatures. These observations suggest that while temperature does not change the final dimensions of the substructure significantly, it appears to influence the kinetics of substructure formation by influencing the recovery rate. As a result, the stresses acting on the cell boundaries increase considerably with increasing temperature to values several times the applied stress. C1 RICE UNIV,DEPT MAT SCI,HOUSTON,TX 77251. RP RAJ, SV (reprint author), NASA,LEWIS RES CTR,MS 49-1,CLEVELAND,OH 44135, USA. NR 28 TC 3 Z9 3 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD FEB PY 1992 VL 75 IS 2 BP 347 EP 352 DI 10.1111/j.1151-2916.1992.tb08185.x PG 6 WC Materials Science, Ceramics SC Materials Science GA HE103 UT WOS:A1992HE10300011 ER PT J AU BHATT, RT AF BHATT, RT TI OXIDATION EFFECTS ON THE MECHANICAL-PROPERTIES OF A SIC-FIBER-REINFORCED REACTION-BONDED SI3N4 MATRIX COMPOSITE SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID STRENGTH AB The room-temperature mechanical properties of a SiC-fiber-reinforced reaction-bonded silicon nitride composite were measured after 100 h treatment in nitrogen and oxygen environments to 1400-degrees-C. The composite heat-treated in nitrogen to 1400-degrees-C showed no appreciable loss in properties. In contrast, composites heat-treated in oxygen from 600-degrees to 1000-degrees-C retained approximately 65% and 35% of the matrix fracture and ultimate strength, respectively, of the as-fabricated composites, and those heat-treated from 1200-degrees to 1400-degrees-C retained greater than 90% and 65% of the matrix fracture and ultimate strength, respectively, of the as-fabricated composites. For all nitrogen and oxygen treatments, the composite displayed strain capability beyond the matrix fracture strength. Oxidation of the fiber surface coating, which caused degradation of bond between the fiber and matrix and reduction in fiber strength, appears to be the dominant mechanism for property degradation of the composites oxidized from 600-degrees to 1000-degrees-C. Formation of a protective silica coating at external surfaces of the composites at and above 1200-degrees-C reduced oxidation of the fiber coating and hence degrading effects of oxidation on their properties. RP USA, AVIAT RES & TECHNOL ACTIV, AVSCOM, PROPULS LAB, LEWIS RES CTR, CLEVELAND, OH 44135 USA. NR 17 TC 23 Z9 23 U1 0 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD FEB PY 1992 VL 75 IS 2 BP 406 EP 412 DI 10.1111/j.1151-2916.1992.tb08194.x PG 7 WC Materials Science, Ceramics SC Materials Science GA HE103 UT WOS:A1992HE10300020 ER PT J AU SCHUBERT, SD SUAREZ, MJ SCHEMM, JK AF SCHUBERT, SD SUAREZ, MJ SCHEMM, JK TI PERSISTENCE AND PREDICTABILITY IN A PERFECT MODEL SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID FORECASTING FORECAST SKILL; ATMOSPHERIC PREDICTABILITY; DYNAMICAL PREDICTABILITY AB The relationship between predictability and persistence is examined using a realistic two-level general circulation model (GCM). Predictability is measured by the average divergence of ensembles of solutions starting from perturbed initial conditions. Persistence is defined in terms of the autocorrelation function based on a single long-term model integration. The average skill of the dynamical forecasts is compared with the skill of simple persistence-based statistical forecasts. For initial errors comparable in magnitude to present-day analysis errors, the statistical forecast loses all skill after about one week, reflecting the lifetime of the lowest frequency fluctuations in the model. On the other hand, large ensemble mean dynamical forecasts would be expected to remain skillful for about three weeks. The disparity between the skill of the statistical and dynamical forecasts is greatest for the higher frequency modes, which have little memory beyond 1 day, yet remain predictable for about two weeks. For small ensembles, the error of the untempered dynamical forecasts must exceed that of the statistical forecasts for sufficiently long predictions. It is noteworthy, however, that for the low-frequency modes this is found to occur at a time when the GCM error is significantly less than would be obtained by forecasting climatology. These results are analyzed in terms of two characteristic time scales. A dynamical time scale (T(d)) is defined as the limiting decay time of a pseudoanomaly correlation and is taken as the measure of predictability. This is compared to the usual statistical time scale (T(s)), which is the integrated autocorrelation function and measures the typical time scale of fluctuations. For the dominant low-frequency (T(s) greater-than-or-equal-to 10 days) modes of fluctuation, the dynamical time scale is between two and three times the statistical time scale. For shorter time scales, the ratio T(d)/T(s) is even greater, reaching six for the shortest time scales considered. This is in contrast to a class of first-order Markov processes with forced-dissipative dynamics for which the two time scales, as defined, are identical. C1 NASA,GODDARD SPACE FLIGHT CTR,GEN SCI CORP,LAUREL,MD. RP SCHUBERT, SD (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GLOBAL MODELING & SIMULAT BRANCH,ATMOSPHERES LAB,CODE 911,GREENBELT,MD 20771, USA. NR 20 TC 15 Z9 15 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD FEB 1 PY 1992 VL 49 IS 3 BP 256 EP 269 DI 10.1175/1520-0469(1992)049<0256:PAPIAP>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HE665 UT WOS:A1992HE66500005 ER PT J AU LAU, KM AF LAU, KM TI EAST-ASIAN SUMMER MONSOON RAINFALL VARIABILITY AND CLIMATE TELECONNECTION SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article AB In this paper, recent progress in the study of the East Asian summer Monsoon (EAM) and its impact on global climate fluctuations are reviewed. The review is focused on the climatology and variability of the EAM rainfall and its relationship with regional and global scale circulation systems. Climatologically, the EAM rainfall is dominated by convective activities associated with the northward advance of the Mei-Yu trough from southern China during April-May to central China during mid-June. After staying in the same position for one to two weeks, the Mei- Yu trough disappears abruptly and a new rainfall zone is developed over northern China. This is followed by a quasi-20 days oscillatory rainfall regime which develops over central China. Subsequently, the maximum rainfall zone returns to the coastal region of south and southeast China. Regional features unique to the EAM include the extraordinary length of the extended monsoon season (April to late August), the extent of the northward penetration of the major precipitation. the multiple onset and interspersed propagation and stationary nature of the rainfall Planetary scale features that directly influence the EAM include the western Pacific Subtropical High, the Tibetan High, the local Hadley and the equatorial Walker circulations. It is stressed that the EAM rainfall is only a small part of global scale precipitation system which migrates northward from the equatorial Indian Ocean and the Western Pacific to the EAM region and Indian subcontinent during the boreal summer. The EAM possesses a wide range of spatial and temporal scales of variabilities including the seasonal cycle, intraseasonal oscillations, subseasonal scale inter-monsoon interactions, sub-synoptic scale variability and supercluster organization in the western Pacific. These variabilities are in turn linked to interannual variations associated with the biennial oscillation and the El Nino/Southern oscillation. Also discussed is evidence showing the presence of an atmospheric teleconnection pattern connecting eastern Asia and North America (ANA) via the North Pacific. The ANA has profound impact on the climate of eastern Asia including Japan. Dynamically, it may be associated with a marginally unstable barotropic mode in the mean northern hemisphere summertime circulation. This mode is also related to latent heating in the western Pacific near Philippines as well as the Indian Ocean region. While there are some successes in the general circulation model (GCM) simulation of the planetary scale features of the EAM, most GCMs still have problems obtaining realistic regional rainfall over East Asia and India. The intraseasonal and interannual variability of the EAM are generally not very well-simulated in GCMs. Much work is needed to improve modeling of the variability of the EAM. RP LAU, KM (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ATMOSPHERES LAB, GREENBELT, MD 20771 USA. RI Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 0 TC 99 Z9 114 U1 3 U2 21 PU METEOROLOGICAL SOC JAPAN PI TOKYO PA C/O JAPAN METEOROLOGICAL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, 100-0004, JAPAN SN 0026-1165 EI 2186-9057 J9 J METEOROL SOC JPN JI J. Meteorol. Soc. Jpn. PD FEB PY 1992 VL 70 IS 1B BP 211 EP 242 PG 32 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HQ621 UT WOS:A1992HQ62100005 ER PT J AU PERRONE, JA AF PERRONE, JA TI MODEL FOR THE COMPUTATION OF SELF-MOTION IN BIOLOGICAL-SYSTEMS SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID TEMPORAL VISUAL AREA; POSTERIOR PARIETAL CORTEX; PURSUIT EYE-MOVEMENTS; OPTICAL-FLOW; MACAQUE MONKEY; EXPANSION CONTRACTION; FUNCTIONAL-PROPERTIES; RESPONSE PROPERTIES; PARALLAX FIELD; ROTATION CELLS AB I present a method by which direction- and speed-tuned cells, such as those commonly found in the middle temporal area of the primate brain, can be used to analyze the patterns of retinal image motion that are generated during observer movement through the environment. For pure translation, the retinal image motion is radial in nature and expands out from a point that corresponds to the direction of heading. This heading direction can be found by the use of translation detectors that act as templates for the radial image motion. Each translation detector sums the outputs of direction- and speed-tuned motion sensors arranged such that their preferred direction of motion lies along the radial direction out from the detector center. The most active detector signifies the heading direction. Rotation detectors can be constructed in a similar fashion to detect areas of uniform image speed and direction in the motion field produced by observer rotation. A model consisting of both detector types can determine the heading direction independently of any rotational motion of the observer. The model can achieve this from the outputs of the two-dimensional motion sensors directly and does not assume the existence of accurate estimates of image speed and direction. It is robust to the aperture problem and is biologically realistic. The basic elements of the model have been shown to exist in the primate visual cortex. C1 STANFORD UNIV,DEPT PSYCHOL,STANFORD,CA 94305. RP PERRONE, JA (reprint author), NASA,AMES RES CTR,HUMAN INTERFACE RES BRANCH,VIS GRP,MS 2622,MOFFETT FIELD,CA 94035, USA. NR 96 TC 111 Z9 111 U1 9 U2 11 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD FEB PY 1992 VL 9 IS 2 BP 177 EP 194 DI 10.1364/JOSAA.9.000177 PG 18 WC Optics SC Optics GA HA800 UT WOS:A1992HA80000001 PM 1542059 ER PT J AU BANSAL, NP AF BANSAL, NP TI HIGH-TC OF UNDOPED AND FLUORINE-DOPED YBA2CU3OY FILMS ON CERAMIC SUBSTRATES BY SCREEN PRINTING SO MATERIALS LETTERS LA English DT Article ID TRANSITION-TEMPERATURE AB Thick films of undoped and fluorine-doped YBa2Cu3Oy were screen printed on highly polished alumina, magnesia spinel, strontium titanate, and yttria-stabilized zirconia (YSZ) substrates. They were annealed at 1000-degrees-C and soaked in oxygen at 450-degrees-C followed by slow cooling to room temperature. The films were characterized by electrical resistivity measurements as a function of temperature and by X-ray diffraction. The films on YSZ showed the best characteristics with a T(c)(onset) of 91 K, T(c)(R = 0) of 88.2 K, and a transition width, DELTA-T(c)(10-90%), of almost-equal-to 1.7 K. The film adhesion, probably controlled by interdiffusion of cations between the film and the substrate, was good in all cases except on strontium titanate where the film completely detached from the substrate. RP BANSAL, NP (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 15 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD FEB PY 1992 VL 13 IS 1 BP 7 EP 11 DI 10.1016/0167-577X(92)90168-J PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA HH577 UT WOS:A1992HH57700002 ER PT J AU MINER, RV CASTELLI, MG AF MINER, RV CASTELLI, MG TI HARDENING MECHANISMS IN A DYNAMIC STRAIN AGING ALLOY, HASTELLOY-X, DURING ISOTHERMAL AND THERMOMECHANICAL CYCLIC DEFORMATION SO METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article AB Isothermal cyclic deformation tests were conducted on HASTELLOY X with a total strain range of +/- 0.3 pct at several temperatures and strain rates. Cyclic hardening exhibited a broad peak between about 200-degrees-C and 700-degrees-C, with a maximum near 500-degrees-C of about 80 pct increase in stress amplitude, DELTA-sigma/2, at failure. The present work examines the mechanisms contributing to this marked cyclic hardening. Cr23C6 precipitation on dislocations contributed to hardening, but only with sufficient time above about 500-degrees-C. The substantial hardening rate at lower temperatures or shorter times was attributed to solute drag. The contribution of solute drag was evidenced in tests at both 400-degrees-C and 600-degrees-C by a continually decreasing strain rate sensitivity of the DELTA-sigma/2. Solute drag alone produced very considerable cyclic hardening. The increase in DELTA-sigma/2 after 1000 cycles at 427-degrees-C was 75 pct of the maximum observed at higher temperatures where carbides did precipitate. Additionally, thermomechanical tests were conducted between various temperature limits, but with the same +/- 0.3 pct mechanical strain range. Hardening was bounded by isothermal behavior at the temperature limits of the thermomechanical cycles, except for tests between 400-degrees-C and 600-degrees-C which exhibited extreme hardening. However, microstructural examination did not suggest a cause. Specimens subjected to thermomechanical cycles appeared similar to those isothermally cycled at the maximum temperature of the thermomechanical cycle, including those from the 400-degrees-C to 600-degrees-C tests. C1 NASA,LEWIS RES CTR,SVERDRUP TECHNOL CORP,CLEVELAND,OH 44135. RP MINER, RV (reprint author), NASA,LEWIS RES CTR,DIV MAT,ADV METALL BRANCH,CLEVELAND,OH 44135, USA. NR 25 TC 34 Z9 34 U1 0 U2 6 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0360-2133 J9 METALL TRANS A PD FEB PY 1992 VL 23 IS 2 BP 551 EP 561 DI 10.1007/BF02801173 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA HD764 UT WOS:A1992HD76400017 ER PT J AU WU, TK AF WU, TK TI SINGLE-SCREEN TRIBAND FSS WITH DOUBLE-SQUARE-LOOP ELEMENTS SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE FREQUENCY SELECTIVE SURFACE; INTEGRATED CIRCUITS; POLARIZATIONS; FILTERS AB A single-screen double-square-loop (DSL) frequency selective surface (FSS) has been developed and tested for triband applications (i.e., to reflect the X-band and to pass the S- and Ku-band waves). Good agreement between predicted and measured transmission performance is obtained for the DSL FSS on a 0.001-in.-thick Kapton with/without a flat Kevlar honeycomb sandwich panel. It is found that this single-screen DSL FSS with/without the Kevlar honeycomb has a resonant frequency near 8.4 GHz for incident angle steered from normal to 45-degrees and for both TE and TM polarizations. RP WU, TK (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 0 TC 14 Z9 16 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0895-2477 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD FEB PY 1992 VL 5 IS 2 BP 56 EP 59 DI 10.1002/mop.4650050203 PG 4 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA HA598 UT WOS:A1992HA59800002 ER PT J AU SIMONS, RN LEE, RQ LINDAMOOD, GR AF SIMONS, RN LEE, RQ LINDAMOOD, GR TI ELECTROMAGNETIC COUPLING BETWEEN COPLANAR WAVE-GUIDE AND MICROSTRIP ANTENNAS SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE COPLANAR WAVE-GUIDE; APERTURE-COUPLED MICROSTRIP PATCH ANTENNAS; PROXIMITY-COUPLED MICROSTRIP PATCH ANTENNAS AB Electromagnetic coupling between coplanar waveguides (CPW) and microstrip patch antennas has been investigated for two feed configurations: (1) direct aperture-coupled feeding of a patch antenna by a CPW feed, and (2) proximity-coupled feeding of a patch antenna by a microstrip line which is aperture coupled to a CPW feed. Results indicate that both feeding approaches are feasible and yield high coupling efficiency. RP SIMONS, RN (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0895-2477 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD FEB PY 1992 VL 5 IS 2 BP 60 EP 62 DI 10.1002/mop.4650050204 PG 3 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA HA598 UT WOS:A1992HA59800003 ER PT J AU ILA, D JENKINS, GM HOLLAND, LR THOMPSON, J EVELYN, L HODGES, A ZIMMERMAN, RL DALINS, I AF ILA, D JENKINS, GM HOLLAND, LR THOMPSON, J EVELYN, L HODGES, A ZIMMERMAN, RL DALINS, I TI MEASUREMENT OF ACCUMULATED CONTAMINANTS IN GLASSY-CARBON BY RBS, ERD AND NRA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 10TH INTERNATIONAL CONF ON ION BEAM ANALYSIS CY JUL 01-05, 1991 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP EINDHOVEN UNIV TECHNOL, CANBERRA IND, APTEC EUROPE, BALZERS PERKIN ELMER PHYS ELECTR, CHARLES EVANS & ASSOC, DUTCH VACUUM SOC, ELSEVIER SCI PUBL, FISONS INSTRUMENTS, FDN FUNDAMENTAL RES MATTER, FDN PHYSICA HO EINDHOVEN UNIV TECHNOL AB It is important to remove water and other gaseous products of carbonization to produce good quality glassy (polymeric) carbon from resin precursors by pyrolysis. In this work, we have used Rutherford backscattering spectroscopy (RBS) and nuclear reaction analysis (NRA) to detect impurity elements in glassy carbon specimens fabricated in our carbon processing laboratory. Elastic recoil detection (ERD) was used to measure hydrogen content. Resonance reactions such as (p,p') and (alpha,alpha') were used to enhance the detectability of various light elements. The results obtained are in agreement with those obtained by electron spectroscopy for chemical analysis (ESCA), thermogravimetric analysis (TGA), and residual gas analysis (RGA). C1 UNIV SAO PAULO,CTR INSTRUMENTAT DOSIMETRY & RADIAT,RIBEIRAO PRETO,BRAZIL. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP ILA, D (reprint author), ALABAMA A&M UNIV,CTR IRRADIAT MAT,HUNTSVILLE,AL 35762, USA. NR 13 TC 1 Z9 1 U1 0 U2 2 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 FEB PY 1992 VL 64 IS 1-4 BP 439 EP 442 DI 10.1016/0168-583X(92)95511-O PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA HK526 UT WOS:A1992HK52600081 ER PT J AU EGALON, CO ROGOWSKI, RS AF EGALON, CO ROGOWSKI, RS TI THEORETICAL-MODEL FOR A THIN CYLINDRICAL FILM OPTICAL FIBER FLUOROSENSOR SO OPTICAL ENGINEERING LA English DT Article DE CYLINDRICAL OPTICAL FIBER; OPTICAL FLUOROSENSOR; ELECTROMAGNETIC THEORY; THIN-FILM SOURCE; EVANESCENT WAVE; OPTICAL FIBER CHEMICAL SENSOR; STEP-INDEX PROFILE FIBER ID FLUORESCENCE; ABSORPTION; EXCITATION AB The behavior of the power efficiency, P(eff), of an optical fiber with a thin-film source distributed in the core/cladding interface is analyzed. The expressions derived make use of the exact filed solution of a cylindrical fiber, whereas previous work has made use of the weakly guiding approximation. Although more complicated and harder to interpret, the formulas presented allow the analysis of the power injection efficiency of fibers with arbitrary differences in indices of refraction. The results obtained are relevant to the design of more efficient optical fiber fluorosensors. In this work, some results using the weakly guiding approximation were confirmed. However, in contrast to the weakly guiding work, we have found that P(eff) does not always increase with the V number. It was found that P(eff) always increases with the difference in the indices of refraction, n(core)-N(clad), and varies only slightly with the wavelength, lambda, and the fiber core radius, a. Finally, by varying a and lambda in such a way as to make their ratio, a/lambda, constant, it was found that P(eff) is also constant. This indicates that a/lambda is a new independent variable. RP EGALON, CO (reprint author), NASA,LANGLEY RES CTR,NONDESTRUCT MEASUREMENT SCI BRANCH,HAMPTON,VA 23665, USA. NR 17 TC 12 Z9 12 U1 0 U2 0 PU SOC PHOTO-OPT INSTRUM ENG PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD FEB PY 1992 VL 31 IS 2 BP 237 EP 244 DI 10.1117/12.56079 PG 8 WC Optics SC Optics GA HD795 UT WOS:A1992HD79500006 ER PT J AU GOORJIAN, PM TAFLOVE, A AF GOORJIAN, PM TAFLOVE, A TI DIRECT TIME INTEGRATION OF MAXWELLS EQUATIONS IN NONLINEAR DISPERSIVE MEDIA FOR PROPAGATION AND SCATTERING OF FEMTOSECOND ELECTROMAGNETIC SOLITONS SO OPTICS LETTERS LA English DT Article AB We report the initial results for femtosecond electromagnetic soliton propagation and collision obtained from first principles, i.e., by a direct time integration of Maxwell's equations. The time integration efficiently implements linear and nonlinear convolutions for the electric polarization and can take into account such quantum effects as Kerr and Raman interactions. The present approach is robust and should permit the modeling of two- and three-dimensional optical soliton propagation, scattering, and switching from the full-vector Maxwell's equations. C1 NORTHWESTERN UNIV,MCCORMICK SCH ENGN,DEPT ELECT ENGN & COMP SCI,EVANSTON,IL 60208. RP GOORJIAN, PM (reprint author), NASA,AMES RES CTR,MAIL STOP 258-1,MOFFETT FIELD,CA 94036, USA. RI Taflove, Allen/B-7275-2009 NR 6 TC 109 Z9 110 U1 1 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD FEB 1 PY 1992 VL 17 IS 3 BP 180 EP 182 DI 10.1364/OL.17.000180 PG 3 WC Optics SC Optics GA HB715 UT WOS:A1992HB71500007 PM 19784268 ER PT J AU CHUNG, KT BHATIA, AK AF CHUNG, KT BHATIA, AK TI IMPORTANCE OF PARAMETRIZING CONSTRAINTS IN QUANTUM-MECHANICAL VARIATIONAL CALCULATIONS SO PHYSICAL REVIEW A LA English DT Article ID COMPLEX-COORDINATE METHOD; I ISOELECTRONIC SERIES; S2 GROUND-STATES; AUTOIONIZATION STATES; SCATTERING REGION; RESONANCES; HE; OPERATORS; MEMBERS; SPECTRA AB In variational calculations of quantum mechanics, constraints are sometimes imposed explicitly on the wave function. These constraints, which are deduced by physical arguments, are often not uniquely defined. In this work, we will point out the advantage of parametrizing constraints and letting the variational principle determine the best possible constraint for the problem. Examples are carried out to show the surprising effectiveness of the variational method if constraints are parametrized. It is also shown that misleading results may be obtained if a constraint is not parametrized. C1 ACAD SINICA,INST ATOM & MOLEC SCI,TAIPEI 115,TAIWAN. NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. NR 34 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB 1 PY 1992 VL 45 IS 3 BP 1449 EP 1453 DI 10.1103/PhysRevA.45.1449 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HC995 UT WOS:A1992HC99500023 ER PT J AU TAI, H AF TAI, H TI GENERATION OF A 2-CENTER OVERLAP INTEGRAL OVER SLATER ORBITALS OF HIGHER PRINCIPAL QUANTUM NUMBERS SO PHYSICAL REVIEW A LA English DT Article ID INFINITE-SERIES REPRESENTATIONS; EXPONENTIAL-TYPE ORBITALS; MOLECULAR INTEGRALS; COULOMB INTEGRALS; B-FUNCTIONS; NUCLEAR ATTRACTION; FORMULAS AB The expressions for two-center overlap integrals between angular s, p, and d Slater orbitals of arbitrary, higher principal quantum number are explicitly listed. The expressions obtained are extremely compact and independent of the coordinate system. It is further shown that the numerical values of the integrals obtained in this way are free from any numerical instability. RP TAI, H (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 37 TC 14 Z9 14 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB 1 PY 1992 VL 45 IS 3 BP 1454 EP 1464 DI 10.1103/PhysRevA.45.1454 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HC995 UT WOS:A1992HC99500024 ER PT J AU CARTWRIGHT, DC CSANAK, G TRAJMAR, S REGISTER, DF AF CARTWRIGHT, DC CSANAK, G TRAJMAR, S REGISTER, DF TI ELECTRON-IMPACT EXCITATION OF THE N 1P LEVELS OF HELIUM - THEORY AND EXPERIMENT SO PHYSICAL REVIEW A LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; ANGULAR-CORRELATION PARAMETERS; MANY-BODY THEORY; EXPERIMENTAL-THEORETICAL COMPARISONS; DISTORTED-WAVE APPROXIMATION; GROUND-STATE; POLARIZATION FRACTIONS; INTERMEDIATE ENERGIES; SCATTERING; ATOMS AB New experimental electron-energy-loss data have been used to extract differential and integral cross sections for excitation of the 2(1)P level, and for the overlapping (3(1)P,3(1)D,3(3)D) levels of helium, at 30-, 50-, and 100-eV incident electron energies. First-order many-body theory (FOMBT) has been used to calculate the differential and integral cross sections for excitation of the n 1P (n = 2,...,6) levels of helium by electron impact, for incident electron energies from threshold to 500 eV. Detailed comparisons between these two new sets of data are made as well as comparisons with appropriate published experimental and theoretical results. A simple scaling relationship is derived from the FOMBT results for n = 2,...,6 that provides differential and integral cross sections for all symmetry final levels of helium with n greater-than-or-equal-to 6. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP CARTWRIGHT, DC (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 66 TC 68 Z9 68 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB 1 PY 1992 VL 45 IS 3 BP 1602 EP 1624 DI 10.1103/PhysRevA.45.1602 PG 23 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HC995 UT WOS:A1992HC99500044 ER PT J AU CSANAK, G CARTWRIGHT, DC TRAJMAR, S AF CSANAK, G CARTWRIGHT, DC TRAJMAR, S TI MAGNETIC-SUBLEVEL CROSS-SECTIONS FOR EXCITATION OF THE N 1P LEVELS OF HELIUM BY ELECTRON-IMPACT SO PHYSICAL REVIEW A LA English DT Article ID PHOTON ANGULAR-CORRELATIONS; EXPERIMENTAL-THEORETICAL COMPARISONS; 21P STATE; ATOMIC ORIENTATION; COLLISIONS; SCATTERING; ALIGNMENT; AMPLITUDES; COINCIDENCE; HE AB First-order many-body theory has been used to calculate collision-frame magnetic-sublevel differential cross sections for electron-impact excitation of the n 1P (n = 2,3,4,5,6) levels of helium for electrons with incident energy in the 25-500-eV range. By combining results from electron-impact differential-cross-section measurements and electron-photon coincidence measurements, experimental magnetic-sublevel cross sections have also been derived for the excitation of the 2 1P and 3 1P levels. The theory predicts a pronounced minimum for the M = O magnetic-sublevel differential cross section for incident electron energies around 30 eV. Our theoretical results are compared to the experimental data and some other theoretical results. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP CSANAK, G (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545, USA. NR 41 TC 15 Z9 15 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB 1 PY 1992 VL 45 IS 3 BP 1625 EP 1643 DI 10.1103/PhysRevA.45.1625 PG 19 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA HC995 UT WOS:A1992HC99500045 ER PT J AU WALEFFE, F AF WALEFFE, F TI THE NATURE OF TRIAD INTERACTIONS IN HOMOGENEOUS TURBULENCE SO PHYSICS OF FLUIDS A-FLUID DYNAMICS LA English DT Article ID 3-DIMENSIONAL INSTABILITY; ISOTROPIC TURBULENCE; ENERGY-TRANSFER AB Nonlinear interactions in homogeneous turbulence are investigated using a decomposition of the velocity field in terms of helical modes. There are two helical modes per wave vector and thus eight fundamental triad interactions. These eight elementary interactions fit in only two classes, "R" (for "reverse") and "F" (for "forward"), depending on whether the small-scale helical modes have helicities of the same or of the opposite sign. In a single-triad interaction, the large scale is unstable when the small-scale helical modes have helicities of opposite signs (class "F"), and the medium scale is unstable otherwise (class "R"). It is proposed that, on average, the triple correlations in a turbulent flow correspond to these unstable states. In the limit of nonlocal triads, where one leg is much smaller than the other two, the triadic interscale energy transfer is largest for interactions of class "R". In that case, most of the energy flows locally in wave number, from the medium scale to the smallest, with a comparatively small feedback on the large scale. However, integrating over all scales in an inertial range, the net effect of nonlocal interactions of class "R" is a reverse energy cascade from small to large scales. All other interactions transfer energy upward in wave number. In local triads, this upward energy transfer occurs primarily between modes with helicities of the same sign, through catalytic interactions with a mode whose helicity has the opposite sign. The class "F" interactions transfer energy to the small scales and exist only in three dimensions. The physical processes associated to both classes of interactions are discussed. It is shown that the large local transfers due to nonlocal "R" interactions appear in pairs of opposite signs that nearly cancel each other and the net effect corresponds to an advection in wave space. RP WALEFFE, F (reprint author), STANFORD UNIV,NASA AMES,CTR TURBULENCE RES,BLDG 500,STANFORD,CA 94305, USA. NR 20 TC 151 Z9 151 U1 1 U2 15 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8213 J9 PHYS FLUIDS A-FLUID PD FEB PY 1992 VL 4 IS 2 BP 350 EP 363 DI 10.1063/1.858309 PG 14 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA HA083 UT WOS:A1992HA08300016 ER PT J AU STALLCOP, JR PARTRIDGE, H LEVIN, E AF STALLCOP, JR PARTRIDGE, H LEVIN, E TI COLLISION INTEGRALS FOR THE INTERACTION OF THE IONS OF NITROGEN AND OXYGEN IN A PLASMA AT HIGH-TEMPERATURES AND PRESSURES SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID IONIZED-GASES; STATE AB The corrections to the transport cross sections and collision integrals for Coulomb interactions arising from the application of realistic interaction energies of the ions of nitrogen and oxygen have been investigated. Accurate potential energy curves from an ab initio electronic structure calculation and a semiclassical description of the scattering are used to determine the difference between the cross sections for the real interaction forces and a Coulomb force for large values of the Debye shielding parameter. Graphs of the correction to the diffusion and viscosity collision integrals are presented for temperatures from about 10 000 K to 150 000 K. This correction can be combined with tabulations of the collision integrals for shielded Coulomb potentials to determine the contribution of N+ -N+, N+ -O+, and O+ -O+ interactions to the transport properties of high-temperature air. Analytical forms have been fitted to the calculated results to assist this application. C1 NASA,AMES RES CTR,ADV COMP SCI RES INST,MOFFETT FIELD,CA 94035. RP STALLCOP, JR (reprint author), NASA,AMES RES CTR,DIV THERMOSCI,COMPUTAT CHEM BRANCH,MOFFETT FIELD,CA 94035, USA. NR 21 TC 7 Z9 7 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD FEB PY 1992 VL 4 IS 2 BP 386 EP 391 DI 10.1063/1.860288 PG 6 WC Physics, Fluids & Plasmas SC Physics GA HC432 UT WOS:A1992HC43200015 ER PT J AU LANGEL, RA AF LANGEL, RA TI INTERNATIONAL GEOMAGNETIC REFERENCE FIELD, 1991 REVISION - INTERNATIONAL-ASSOCIATION-OF-GEOMAGNETISM-AND-AERONOMY (IAGA) DIVISION-V, WORKING GROUP-8 - ANALYSIS OF THE MAIN FIELD AND SECULAR VARIATION SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article ID GENERATION RP LANGEL, RA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,CODE 921,GREENBELT,MD 20771, USA. NR 12 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD FEB PY 1992 VL 70 IS 1-2 BP 1 EP 6 DI 10.1016/0031-9201(92)90155-O PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HE338 UT WOS:A1992HE33800001 ER PT J AU AIKIN, AC AF AIKIN, AC TI STRATOSPHERIC EVIDENCE OF RELATIVISTIC ELECTRON-PRECIPITATION SO PLANETARY AND SPACE SCIENCE LA English DT Article ID MIDDLE ATMOSPHERE; OZONE; MESOSPHERE; EVENT AB The hypothesis that relativistic electron precipitation is modifying the high-latitude southern hemisphere ozone distribution is tested by examining simultaneous electron density data as measured with a ground-based partial reflections sounder and ozone mixing ratios data in the 40 to 50 km region obtained from the satellite-borne SBUV instrument. Electrons with energies in the 1 to 3 MeV range are stopped in this altitude region creating ionization, which can be observed as an enhancement in electron density. The resulting nitric oxide should destroy ozone. Ionization enhancement events at 50 km are observed at least 20% of the time by the partial reflections sounder at Scott Base, Antarctica. On January 15, 1984, the electron density at 50 km was 800 cm-3 (von Biel, 1989, 1991). Since the ion-pair production function requited to produce this amount of ionization was 300 cm-3 s-1 and acted over a day, the corresponding reduction in ozone is expected to be more than 40%. Examination of ozone mixing ratio data from the SBUV instrument on Nimbus 7 shows no corresponding ozone decrease in the January 15 to 17, 1984 period. Possible explanations for this failure to observe an ozone decrease include another mechanism for producing the electron density enhancement or relativistic electron precipitation in a very limited area. The relativistic electron fluxes in the 1 to 3 MeV range required to produce the partial reflection electron density profiles are the same as observed by geosynchronously orbiting spacecraft. In addition to finding no ozone decrease there are two difficulties with assuming that the partial reflection electron densities are caused by the electrons observed in orbit. The L value of die field lines containing the electrons are L = 3 to 8, while Scott Base is located at L = 33. The electron density profiles observed at Scott Base are not enhanced above 70 km indicating a lack of precipitating electron with energies less than 1 MeV. It is suggested that a more complete study be undertaken, including many events, corresponding in-orbit electron flux changes and ground-based riometer data in addition to ozone and partial reflection data. RP AIKIN, AC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771, USA. NR 34 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD FEB-MAR PY 1992 VL 40 IS 2-3 BP 413 EP 431 DI 10.1016/0032-0633(92)90072-V PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HL073 UT WOS:A1992HL07300018 ER PT J AU LAM, NSN QUATTROCHI, DA AF LAM, NSN QUATTROCHI, DA TI ON THE ISSUES OF SCALE, RESOLUTION, AND FRACTAL ANALYSIS IN THE MAPPING SCIENCES SO PROFESSIONAL GEOGRAPHER LA English DT Article AB Scale and resolution have long been key issues in geography. The rapid development of analytical cartography, GIS, and remote sensing (the mapping sciences) in the last decade has forced the issues of scale and resolution to be treated formally and better defined. This paper addresses the problem of scale and resolution in geographical studies, with special reference to the mapping sciences. The fractal concept is introduced, and its use in identifying the scale and resolution problem is discussed. The implications of the scale and resolution problem on studies of global change and modeling are also explored. C1 NASA,SCI & TECHNOL LAB,BAY ST LOUIS,MS 39529. RP LAM, NSN (reprint author), LOUISIANA STATE UNIV,GEOG,BATON ROUGE,LA 70803, USA. NR 49 TC 138 Z9 169 U1 3 U2 32 PU BLACKWELL PUBLISHERS PI CAMBRIDGE PA 350 MAIN STREET, STE 6, CAMBRIDGE, MA 02148-5023 SN 0033-0124 J9 PROF GEOGR JI Prof. Geogr. PD FEB PY 1992 VL 44 IS 1 BP 88 EP 98 DI 10.1111/j.0033-0124.1992.00088.x PG 11 WC Geography SC Geography GA HG503 UT WOS:A1992HG50300015 ER PT J AU KIMES, DS DEERING, DW AF KIMES, DS DEERING, DW TI REMOTE-SENSING OF SURFACE HEMISPHERICAL REFLECTANCE (ALBEDO) USING POINTABLE MULTISPECTRAL IMAGING SPECTRORADIOMETERS SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID FACTOR DISTRIBUTIONS; VEGETATION CANOPIES; RADIOMETER; RADIANCE; NADIR AB Several techniques that use multiple off-nadir view angles taken in a single azimuth plane (called a string of data) to estimate hemispherical reflectance have been developed. The range of view angles that is required in order to obtain accurate inferences of hemispherical reflectance using string techniques was studied as applicable to the Moderate Resolution Imaging Spectroradiometer (MODIS) and the High Resolution Imaging Spectroradiometer (HIRIS). Full and half strings out to 60-degrees, 45-degrees, 30-degrees, and 15-degrees were tested on ground data of a wide range of cover types and sun angles. Both a visible and near infrared band (AVHRR Bands 1 and 2) were tested using a knowledge-based system called VEG. Using string techniques that calculate a single coefficient from an internal spectral data base, the results showed small errors for the full string +/- 60-degrees (less than 4% error), HIRIS like data (less than 5% error), and MODIS like data (less than 7% error). Much larger errors occur in those cases where long extrapolations must be calculated (e.g., strings to only 15-degrees and 30-degrees). Systems that view fore and aft out to 60-degrees would be desirable to minimize errors, assuming atmospheric corrections could be made at these angles. HIRIS (views 60-degrees in forward and 30-degrees in aft directions) is a good compromise by viewing out to 60-degrees in only one direction and increases the error by approximately 2% or less. MODIS (full string +/- 45-degrees) still has a relatively small error of approximately 5% or less. Sensor systems capable of only viewing in the fore or aft directions (half strings) as opposed to both directions (full strings) greatly increase the error. RP KIMES, DS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,BIOSPHER SCI BRANCH,CODE 923,GREENBELT,MD 20771, USA. NR 21 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD FEB PY 1992 VL 39 IS 2 BP 85 EP 94 DI 10.1016/0034-4257(92)90128-7 PG 10 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA HE859 UT WOS:A1992HE85900001 ER PT J AU CURRAN, PJ DUNGAN, JL MACLER, BA PLUMMER, SE PETERSON, DL AF CURRAN, PJ DUNGAN, JL MACLER, BA PLUMMER, SE PETERSON, DL TI REFLECTANCE SPECTROSCOPY OF FRESH WHOLE LEAVES FOR THE ESTIMATION OF CHEMICAL CONCENTRATION SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID CANOPY CHEMISTRY; FOREST CANOPY; SPECTROMETRY AB In an effort to further develop the methods needed to remotely sense the biochemical content of plant canopies, we report the results of an experiment to relate the concentrations of chlorophyll, protein, starch, sugar, amaranthin, and water in fresh whole leaves to their reflectance at wavelengths throughout the visible and near infrared. This is an analysis of laboratory data from a previously reported experiment (Curran et al., 1991) in which 163 freshly excised leaves of the plant Amaranthus tricolor were measured for reflectance and biochemical content. Stepwise regression was used to generate an equation for the estimation of chemical concentration from derivative reflectance in selected wavelengths. The reduction of instrument noise through Fourier filtering and a sample control procedure to minimize spectral overlap had little effect on the correlation between derivative reflectance in selected wavelengths and chemical concentration but did enable absorption features attributable to sugar and protein to be detected. However, the minimization of spectral overlap did increase the number of wavelengths attributable to known absorption features that were selected by stepwise procedures. Using only derivative reflectance in wavelengths that were attributable to absorption by the chemical of interest, the coefficients of determination (R2) between estimated and measured concentrations of chlorophyll, amaranthin, starch, and water were 0.82 or above, with root-mean square errors that were 12.5% of the median or less. C1 TGS TECHNOL INC,MOFFETT FIELD,CA. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. US EPA,DRINKING WATER BRANCH W-6-1,WASHINGTON,DC 20460. BRITISH NATL SPACE CTR,REMOTE SENSING APPL DEV UNIT,HUNTINGDON,CAMBS,ENGLAND. RP CURRAN, PJ (reprint author), UNIV COLL SWANSEA,DEPT GEOG,SINGLETON PK,SWANSEA SA2 8PP,W GLAM,WALES. RI Dungan, Jennifer/G-9921-2016 OI Dungan, Jennifer/0000-0002-4863-1616 NR 36 TC 150 Z9 166 U1 6 U2 33 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD FEB PY 1992 VL 39 IS 2 BP 153 EP 166 DI 10.1016/0034-4257(92)90133-5 PG 14 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA HE859 UT WOS:A1992HE85900006 ER PT J AU BARNES, A AF BARNES, A TI ACCELERATION OF THE SOLAR-WIND SO REVIEWS OF GEOPHYSICS LA English DT Review ID POLAR CORONAL HOLE; ALFVEN WAVES; HELIOGRAPHIC LATITUDES; GLOBAL PROCESSES; ENERGY-FLOW; INSTABILITIES; ELECTRONS; PIONEER; MODEL; SUN AB Stellar winds are thought to be the primary mass loss process for most stars and to play a particularly important role in mass and angular momentum transfer in newly forming stars. The physical processes that account for the acceleration of such winds are therefore of fundamental importance in astrophysics but are at present poorly understood, even for the case of the Sun. The question of just how the solar wind is accelerated to hypersonic speeds has been one of the most fundamental questions of space science since the beginning of the space age and is still far from a definitive solution. In this present review I give a general overview of some of the problems associated with trying to understand the physics of solar wind acceleration, how these problems have been approached, and the kinds of observational and theoretical efforts needed to facilitate closure between theory and observation. RP BARNES, A (reprint author), NASA,AMES RES CTR,MS 245-3,MOFFETT FIELD,CA 94035, USA. NR 99 TC 24 Z9 25 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD FEB PY 1992 VL 30 IS 1 BP 43 EP 55 DI 10.1029/91RG02816 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HK888 UT WOS:A1992HK88800003 ER PT J AU MOLINE, ML POLLAK, CP MONK, TH LESTER, LS WAGNER, DR ZENDELL, SM GRAEBER, RC SALTER, CA HIRSCH, E AF MOLINE, ML POLLAK, CP MONK, TH LESTER, LS WAGNER, DR ZENDELL, SM GRAEBER, RC SALTER, CA HIRSCH, E TI AGE-RELATED DIFFERENCES IN RECOVERY FROM SIMULATED JET-LAG SO SLEEP LA English DT Article DE JET LAG; SLEEP; CIRCADIAN RHYTHMS; AGING ID SLOW-WAVE SLEEP; INDIVIDUAL-DIFFERENCES; CIRCADIAN-RHYTHM; SHIFT-WORK; REM-SLEEP; PERFORMANCE; TEMPERATURE; DEPRIVATION; INSOMNIACS; CYCLE AB Six healthy young men and eight early middle-aged men were isolated from environmental time cues for 15 days. For the first 6-7 days (one or two nights adaptation, four nights baseline), their sleep and meals were scheduled to approximate their habitual patterns. Their daily routines were then shifted 6 hours earlier by terminating the sixth or seventh sleep episode 6 hours early. The new schedules were followed for the next 8 or 9 days. Important age-related differences in adjustment to this single 6-hour schedule shift were found. For the first 4-day interval after the shift, middle-aged subjects had larger increases of waking time during the sleep period and earlier termination of sleep than young subjects. They also reported larger decreases in alertness and well-being and larger increases in sleepiness, weariness and effort required to perform daily functions. The rate of adjustment of the circadian core temperature rhythm to the new schedule did not differ between groups. These results suggest that the symptoms reported by the middle-aged subjects may be due mainly to difficulty maintaining sleep at early times of the circadian day. The compensatory response to sleep deprivation may also be less robust in middle-aged individuals traveling eastbound. C1 WESTERN PSYCHIAT INST & CLIN,PITTSBURGH,PA 15261. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. USA,NATICK RD&E CTR,NATICK,MA 01760. RP MOLINE, ML (reprint author), NEW YORK HOSP,CORNELL MED CTR,INST CHRONOBIOL,21 BLOOMINGDALE RD,WHITE PLAINS,NY 10605, USA. NR 46 TC 54 Z9 55 U1 0 U2 2 PU AMER SLEEP DISORDERS ASSOC PI ROCHESTER PA 1610 14TH STREET NW SUITE 300, ROCHESTER, MN 55806 SN 0161-8105 J9 SLEEP JI Sleep PD FEB PY 1992 VL 15 IS 1 BP 28 EP 40 PG 13 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA HF940 UT WOS:A1992HF94000004 PM 1557592 ER PT J AU AGBU, PA OLSON, KR AF AGBU, PA OLSON, KR TI MODEL TO PREDICT SOIL PARENT MATERIAL UNDERLYING A LOESS MANTLE IN ILLINOIS FROM SATELLITE DATA SO SOIL SCIENCE LA English DT Article ID ORGANIC-MATTER; DIGITAL DATA; REFLECTANCE; TM AB Low accuracy of soil spectral classes within areas with thin surficial mantles is often due to confusion caused by differences in the underlying parent materials in large imageries. This study was conducted to determine whether satellite digital data could be used to predict underlying soil parent material at specific locations in a glaciated landscape with a thin loess mantle. Soils were sampled on two regular grids, each covering an area of 3,108 ha, in Ford County, Illinois. The soils developed in thin loess over both loamy and clayey glacial till, outwash, and lacustrine sediments of the Wisconsinan glaciation. Satellite spectral data obtained over parent materials underlying a thin loess mantle and from an undulating site were statistically analyzed by multiple-regression procedure to develop a model (linear equation) to predict underlying soil parent material with a thin loess mantle. Correlations between underlying parent material and the red band, green band, and brightness index were significant (0.212, 0.267, and 0.176, respectively) at the 0.01 level. The absence of loess mantle at some of the undulating reference sites due to erosion and the presence of a new parent material underlying the loess mantle at the test site contributed to the differences between predicted and observed underlying parent materials. For these reasons correlations presented only accounted for a small amount of the variation. Model-predicted underlying parent materials of the nearly level test area showed a significant correlation of 0.148 with actual values. The possibility for reasonable subdivision of an image suggests a potential for improving spectral soil maps by separation of large survey areas with thin loess mantles by underlying parent materials prior to computer classification. C1 UNIV ILLINOIS,DEPT AGRON,URBANA,IL 61801. RP AGBU, PA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 25 TC 3 Z9 3 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0038-075X J9 SOIL SCI JI Soil Sci. PD FEB PY 1992 VL 153 IS 2 BP 142 EP 148 DI 10.1097/00010694-199202000-00008 PG 7 WC Soil Science SC Agriculture GA HF840 UT WOS:A1992HF84000008 ER PT J AU ESHER, RJ MARX, DH URSIC, SJ BAKER, RL BROWN, LR COLEMAN, DC AF ESHER, RJ MARX, DH URSIC, SJ BAKER, RL BROWN, LR COLEMAN, DC TI SIMULATED ACID-RAIN EFFECTS ON FINE ROOTS, ECTOMYCORRHIZAE, MICROORGANISMS, AND INVERTEBRATES IN PINE FORESTS OF THE SOUTHERN UNITED-STATES SO WATER AIR AND SOIL POLLUTION LA English DT Article ID MYCORRHIZAL INFECTION; SEEDLINGS; EXTRACTS; DECLINE; SPRUCE; OZONE; SOILS AB A 2-yr study evaluated the effects of acid precipitation on the forest floor community. Throughfall was collected at weekly intervals, acidified to pH 4.3 and 3.6, and applied to throughfall excluded 1 m2 plots in a stand of loblolly pine (Pinus taeda L.) in south Mississippi, and in a longleaf pine (P. palustris Mill.) plantation in east Texas. Control plots received ambient throughfall which ranged from pH 3.7 to 6.2 in Mississippi and pH 3.8 to 6.7 in Texas. Five plots of each treatment at each location were destructively sampled after 1 yr and the 5 remaining plots were sampled after 2 yr. Chemical analyses were conducted for all collections of throughfall and litter leachate, and for the fermentation layer, rhizosphere, and mineral soil. After 2 yr, comparisons of the pH 3.6 plots with the controls indicated significant decreases in the number, length and biomass of lateral roots, and the percent and number of ectomycorrhizae. Decreases in these root characteristics for plots subjected to applications of throughfall acidified to near-ambient pH 4.3 were also significant or bordered on significance. Numbers of herbivorous mites increased significantly with decreasing pH, but the predaceous mites appeared insensitive. Treated plots had fewer numbers of some groups of the larger invertebrates, especially earthworms, but variation was generally too great to show significance. The acid treatments had little effect on numbers of nematodes, saprophytic fungi or endomycorrhizal fungi. C1 UNIV GEORGIA,DEPT ENTOMOL,ATHENS,GA 30601. US FOREST SERV,INST TREE ROOT BIOL,ATHENS,GA 30601. US FOREST SERV,FOREST HYDROL LAB,OXFORD,MS 38655. MISSISSIPPI STATE UNIV,DEPT BIOL SCI,MISSISSIPPI STATE,MS 39762. RP ESHER, RJ (reprint author), MISSISSIPPI STATE UNIV,STENNIS SPACE CTR,RES CTR,MISSISSIPPI STATE,MS 39529, USA. NR 33 TC 17 Z9 20 U1 2 U2 14 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD FEB PY 1992 VL 61 IS 3-4 BP 269 EP 278 DI 10.1007/BF00482610 PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA HC634 UT WOS:A1992HC63400007 ER PT J AU BELTON, MJS HEAD, JW PIETERS, CM GREELEY, R MCEWEN, AS NEUKUM, G KLAASEN, KP ANGER, CD CARR, MH CHAPMAN, CR DAVIES, ME FANALE, FP GIERASCH, PJ GREENBERG, R INGERSOLL, AP JOHNSON, T PACZKOWSKI, B PILCHER, CB VEVERKA, J AF BELTON, MJS HEAD, JW PIETERS, CM GREELEY, R MCEWEN, AS NEUKUM, G KLAASEN, KP ANGER, CD CARR, MH CHAPMAN, CR DAVIES, ME FANALE, FP GIERASCH, PJ GREENBERG, R INGERSOLL, AP JOHNSON, T PACZKOWSKI, B PILCHER, CB VEVERKA, J TI LUNAR IMPACT BASINS AND CRUSTAL HETEROGENEITY - NEW WESTERN LIMB AND FAR SIDE DATA FROM GALILEO SO SCIENCE LA English DT Article ID ORIENTALE; DEPOSITS AB Multispectral images Of the lunar western limb and far side obtained from Galileo reveal the compositional nature of several prominent lunar features and provide new information on lunar evolution. The data reveal that the ejecta from the Orientale impact basin (900 kilometers in diameter) lying outside the Cordillera Mountains was excavated from the crust, not the mantle, and covers pre-Orientale terrain that consisted of both highland materials and relatively large expanses of ancient mare basalts. The inside of the far side South Pole - Aitken basin (> 2000 kilometers in diameter) has low albedo, red color, and a relatively high abundance of iron- and magnesium-rich materials. These features suggest that the impact may have penetrated into the deep crust or lunar mantle or that the basin contains ancient mare basalts that were later covered by highlands ejecta. C1 CALTECH,PASADENA,CA 91125. ITRES RES LTD,CALGARY T2E 7H7,ALBERTA,CANADA. NASA HEADQUARTERS,WASHINGTON,DC 20546. BROWN UNIV,PROVIDENCE,RI 02912. ARIZONA STATE UNIV,TEMPE,AZ 85287. US GEOL SURVEY,FLAGSTAFF,AZ 86001. DFVLR,W-8031 OBERPFAFFENHOFEN,GERMANY. CALTECH,JET PROP LAB,PASADENA,CA 91109. US GEOL SURVEY,MENLO PK,CA 94025. SCI APPLICAT INT CORP,INST PLANETARY SCI,TUCSON,AZ 85719. RAND CORP,SANTA MONICA,CA 90406. UNIV HAWAII,HONOLULU,HI 96822. CORNELL UNIV,ITHACA,NY 14853. UNIV ARIZONA,TUCSON,AZ 85721. RP BELTON, MJS (reprint author), NATL OPT ASTRON OBSERV,TUCSON,AZ 85719, USA. NR 37 TC 62 Z9 63 U1 1 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 31 PY 1992 VL 255 IS 5044 BP 570 EP 576 DI 10.1126/science.255.5044.570 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HB531 UT WOS:A1992HB53100036 PM 17792379 ER PT J AU GROPP, WD KEYES, DE AF GROPP, WD KEYES, DE TI DOMAIN DECOMPOSITION METHODS IN COMPUTATIONAL FLUID-DYNAMICS SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE DOMAIN DECOMPOSITION; COMPUTATIONAL FLUID DYNAMICS; PRECONDITIONED KRYLOV ITERATION; NEWTON METHOD; LOCALLY UNIFORM MESH REFINEMENT ID FLOW; STEP AB The divide-and-conquer paradigm of iterative domain decomposition or substructuring has become a practical tool in computational fluid dynamics applications because of its flexibility in accommodating adaptive refinement through locally uniform (or quasi-uniform) grids, its ability to exploit multiple discretizations of the operator equations, and the modular pathway it provides towards parallelism. We illustrate these features on the classic model problem of flow over a backstep using Newton's method as the non-linear iteration. Multiple discretizations (second-order in the operator and first-order in the pre-conditioner) and locally uniform mesh refinement pay dividends separately and can be combined synergistically. We include sample performance results from an Intel iPSC/860 hypercube implementation. C1 NASA,LANGLEY RES CTR,INST COMP APPLICAT SCI & ENGN,HAMPTON,VA 23665. YALE UNIV,DEPT MECH ENGN,NEW HAVEN,CT 06520. RP GROPP, WD (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439, USA. OI Gropp, William/0000-0003-2905-3029 NR 29 TC 16 Z9 16 U1 1 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD JAN 30 PY 1992 VL 14 IS 2 BP 147 EP 165 DI 10.1002/fld.1650140203 PG 19 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA HA198 UT WOS:A1992HA19800002 ER PT J AU CHOI, SR SALEM, JA AF CHOI, SR SALEM, JA TI SLOW CRACK-GROWTH OF INDENT CRACKS IN GLASS WITH AND WITHOUT APPLIED STRESS SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article ID DYNAMIC FATIGUE; FAILURE; FLAWS AB The slow crack growth behavior occurring in dynamic fatigue and post-indentation fatigue with no applied stress was compared for indented soda-lime glass specimens in six different environments at room temperature. A significant difference between the fatigue behaviors in the two methods was found, indicating that the post-indentation fatigue (slow crack growth) is unique but that such an approach is not appropriate to evaluate fatigue parameters for use in life prediction. The exsitence of a plateau region in the post-indentation crack growth-time data was attributed to a fatigue limit for each test environment, as verified by the aging strength data. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP CHOI, SR (reprint author), CLEVELAND STATE UNIV,CLEVELAND,OH 44115, USA. NR 12 TC 14 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 30 PY 1992 VL 149 IS 2 BP 259 EP 264 DI 10.1016/0921-5093(92)90387-G PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA HF231 UT WOS:A1992HF23100013 ER PT J AU CINTALA, MJ AF CINTALA, MJ TI IMPACT-INDUCED THERMAL EFFECTS IN THE LUNAR AND MERCURIAN REGOLITHS SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Review ID REFLECTANCE SPECTRA; PLANET MERCURY; SURFACE; SODIUM; MOON; ATMOSPHERE; POTASSIUM; DEPENDENCE; PETROLOGY; DISCOVERY AB While the Moon and Mercury are similar objects in a geomorphologic sense, they also possess important differences, particularly in the context of small-scale impact phenomena. Not only is the surface of Mercury notably hotter than that of the Moon, but the impact flux is also more intense at Mercury due to higher impact velocities and a greater spatial density of micrometeoroids. By extrapolating the terrestrial micrometeoroid flux to the Moon and Mercury, it is found that the impact rate at Mercury is 5.5 times greater and the mean impact velocity more than 60 percent higher than at the Moon. A model of impact melding and vaporization applied to the lunar and mercurian environments indicates that almost 14 times more impact melt and over 20 times more vapor are generated per unit time in the mercurian regolith. Although the surface temperature plays a role in determining the melt and vapor volumes, the difference in impact velocity appears to be markedly more important. ''Average'' craters formed by identical projectiles under the two velocity distributions on the two planets should be very similar in size, because differences in the kinetic energy of the ''average'' impactors will be offset by the differences in gravitational acceleration. As a result, variations in regolith mixing should depend more on the actual impact rates than on disparities in excavated volumes. Each ''average'' impact on Mercury, however, will produce more than twice as much impact melt as its lunar counterpart, introducing more glass into the mercurian regolith. Although substantial quantities of impact vapor are produced on both planets, mixing of the regolith should occur quickly enough in each case to spread the deposited vapor over large surface areas; the resulting vapor coatings should be negligibly small for most purposes. A much larger agglutinate population should exist on Mercury, and individual agglutinates should be similar to those of the lunar highlands. Reflectance spectra and visual albedos indicate that the mercurian crust possesses relatively small quantities of Fe2+ perhaps similar to those of Apollo 16 light- and dark-matrix breccias. Laboratory studies have demonstrated that, as the magnetic fractions (which are correlated with agglutinate abundances) of soils derived from these breccias increase, the differences in 0.565-mm (visible light) reflectivity between the soils diminish. Should the regional variations in Fe-content of the mercurian crust be similar to those of these Apollo 16 samples, then the intense agglutination environment could account for the lack of optical contrast across the mercurian surface. At the same time, the very large fraction of impact glass in the regolith would imply that most pyroxenes have been fused and incorporated into these glasses, seriously attenuating the Fe2+ crystal-field absorption near 0.9-mm. Supporting this picture are the most recently published spectral observations of Mercury, which provide little or no evidence of such an absorption feature. C1 NASA,LYNDON B JOHNSON SPACE CTR,DIV SOLAR SYST EXPLORAT,HOUSTON,TX 77058. NR 138 TC 216 Z9 218 U1 1 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD JAN 25 PY 1992 VL 97 IS E1 BP 947 EP 973 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA KU045 UT WOS:A1992KU04500001 ER PT J AU FULLER, D AF FULLER, D TI DIGGING OUT THE PAST BY SATELLITE .1. SO NEW SCIENTIST LA English DT Editorial Material C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP FULLER, D (reprint author), UNIV MARYLAND,COLLEGE PK,MD 20742, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NEW SCIENTIST PUBL EXPEDITING INC PI ELMONT PA 200 MEACHAM AVE, ELMONT, NY 11003 SN 0262-4079 J9 NEW SCI JI New Sci. PD JAN 25 PY 1992 VL 133 IS 1805 BP 43 EP 43 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HB441 UT WOS:A1992HB44100036 ER PT J AU SCHWENKE, DW AF SCHWENKE, DW TI THE CHOICE OF COORDINATES FOR DESCRIBING VIBRATIONS IN H2O SO CHEMICAL PHYSICS LETTERS LA English DT Article ID TRIATOMIC-MOLECULES; WATER MOLECULE AB We consider several different coordinate systems for calculating vibrational energy levels of the water molecule. The relative effectiveness of the various coordinate systems is judged by comparing the error in predicting the ground vibrational level energy using a self-consistent wave function. Radau coordinates are found to be the system of choice, since while they are not the optimum coordinates, they are only slightly worse than an optimized, nonorthogonal, set of coordinates. RP SCHWENKE, DW (reprint author), NASA,AMES RES CTR,MS 230-3,MOFFETT FIELD,CA 94035, USA. RI schwenke, david/I-3564-2013 NR 15 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JAN 24 PY 1992 VL 189 IS 1 BP 91 EP 94 DI 10.1016/0009-2614(92)85158-7 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HD867 UT WOS:A1992HD86700016 ER PT J AU BOECK, WL VAUGHAN, OH BLAKESLEE, R VONNEGUT, B BROOK, M AF BOECK, WL VAUGHAN, OH BLAKESLEE, R VONNEGUT, B BROOK, M TI LIGHTNING INDUCED BRIGHTENING IN THE AIRGLOW LAYER SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB This report describes a transient luminosity observed at the altitude of the airglow layer (about 95 km) in coincidence with a lightning flash in a tropical oceanic thunderstorm directly beneath it. This event provides new evidence of direct coupling between lightning and ionospheric events. This luminous event in the ionosphere was the only one of its kind observed during an examination of several thousand images of lightning recorded under suitable viewing conditions with Space Shuttle cameras. Several possible mechanisms and interpretations are discussed briefly. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. SUNY ALBANY,ALBANY,NY 12222. NEW MEXICO INST MIN & TECHNOL,SOCORRO,NM 87801. RP BOECK, WL (reprint author), NIAGARA UNIV,DEPT CIS,NEW YORK,NY 14109, USA. NR 6 TC 81 Z9 84 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 99 EP 102 DI 10.1029/91GL03168 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700006 ER PT J AU HEFLIN, M BERTIGER, W BLEWITT, G FREEDMAN, A HURST, K LICHTEN, S LINDQWISTER, U VIGUE, Y WEBB, F YUNCK, T ZUMBERGE, J AF HEFLIN, M BERTIGER, W BLEWITT, G FREEDMAN, A HURST, K LICHTEN, S LINDQWISTER, U VIGUE, Y WEBB, F YUNCK, T ZUMBERGE, J TI GLOBAL GEODESY USING GPS WITHOUT FIDUCIAL SITES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Baseline lengths and geocentric radii have been determined from GPS data without the use of fiducial sites. Data from the first GPS experiment for the IERS and Geodynamics (GIG '91) have been analyzed with a no-fiducial strategy. A baseline length daily repeatability of 2 mm + 4 parts per billion was obtained for baselines in the northern hemisphere. Comparison of baseline lengths from GPS and the global VLBI solution GLB659 (Caprette et al. 1990) show rms agreement of 2.1 parts per billion. The geocentric radius mean daily repeatability for all sites was 15 cm. Comparison of geocentric radii from GPS and SV5 (Murray et al. 1990) show rms agreement of 3.8 cm. Given n globally distributed stations, the n(n - 1)/2 baseline lengths and n geocentric radii uniquely define a rigid closed polyhedron with a well-defined center of mass. Geodetic information can be obtained by examining the structure of the polyhedron and its change with time. RP HEFLIN, M (reprint author), CALTECH,JET PROP LAB,MS 238-625,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 13 TC 97 Z9 105 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 131 EP 134 DI 10.1029/91GL02933 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700014 ER PT J AU MCCORMICK, MP AF MCCORMICK, MP TI INITIAL ASSESSMENT OF THE STRATOSPHERIC AND CLIMATIC IMPACT OF THE 1991 MOUNT-PINATUBO ERUPTION - PROLOGUE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article RP MCCORMICK, MP (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,MAIL STOP 475,HAMPTON,VA 23665, USA. NR 0 TC 28 Z9 28 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 149 EP 149 DI 10.1029/91GL00075 PG 1 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700019 ER PT J AU BLUTH, GJS DOIRON, SD SCHNETZLER, CC KRUEGER, AJ WALTER, LS AF BLUTH, GJS DOIRON, SD SCHNETZLER, CC KRUEGER, AJ WALTER, LS TI GLOBAL TRACKING OF THE SO2 CLOUDS FROM THE JUNE, 1991 MOUNT-PINATUBO ERUPTIONS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DEL-RUIZ VOLCANO; PYROCLASTIC DEPOSITS; COLOMBIA AB The explosive June 1991 eruptions of Mount Pinatubo produced the largest sulfur dioxide cloud detected by the Total Ozone Mapping Spectrometer (TOMS) during its 13 years of operation: approximately 20 million tons of SO2, predominantly from the cataclysmic June 15th eruption. The SO2 cloud observed by the TOMS encircled the Earth in about 22 days (approximately 21 m/s); however, during the first three days the leading edge of the SO2 cloud moved with a speed that averaged approximately 35 m/s. Compared to the 1982 El Chichon eruptions, Pinatubo outgassed nearly three times the amount of SO2 during its explosive phases. The main cloud straddled the equator within the first two weeks of eruption, whereas the El Chichon cloud remained primarily in the northern hemisphere. Our measurements indicate that Mount Pinatubo has produced a much larger and perhaps longer-lasting SO2 cloud; thus, climatic responses to the Pinatubo eruption may exceed those of El Chichon. C1 NASA,GODDARD SPACE FLIGHT CTR,HUGHES STX CORP,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,EARTH SCI DIRECTORATE,GREENBELT,MD 20771. RP BLUTH, GJS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,CODE 921,GREENBELT,MD 20771, USA. NR 19 TC 371 Z9 379 U1 6 U2 39 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 151 EP 154 DI 10.1029/91GL02792 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700020 ER PT J AU MCCORMICK, MP VEIGA, RE AF MCCORMICK, MP VEIGA, RE TI SAGE-II MEASUREMENTS OF EARLY PINATUBO AEROSOLS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERIC AEROSOL AB SAGE II satellite measurements of the Mt. Pinatubo eruption cloud in the stratosphere during June, July, and early August 1991 show that aerosols in the tropics reached as high as 29 km altitude with most of the cloud between 20 and 25 km. The most optically thick portions of the cloud covered latitudes from 10-degrees-S to 30-degrees-N during the early part of this period. By late July, high stratospheric optical depths were observed to at least 70-degrees-N, with the high values north of about 30-degrees-N from layers below 20 km. High pressure systems in both hemispheres were observed to be correlated with the movement of volcanic material at 21 km into the westerly jet stream at high southern latitudes and similarly to high northern latitudes at 16 km. By August, the entire Southern Hemisphere had experienced a 10-fold increase in optical depth relative to early July due to layers above 20 km. Initial mass calculations using SAGE II data place the aerosol produced from this eruption at 20 to 30 megatonnes, well above the 12 megatonnes produced by El Chichon. C1 HUGHES STX CORP,HAMPTON,VA 23666. RP MCCORMICK, MP (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,MAIL STOP 475,HAMPTON,VA 23665, USA. NR 15 TC 292 Z9 301 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 155 EP 158 DI 10.1029/91GL02790 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700021 ER PT J AU VALERO, FPJ PILEWSKIE, P AF VALERO, FPJ PILEWSKIE, P TI LATITUDINAL SURVEY OF SPECTRAL OPTICAL DEPTHS OF THE PINATUBO VOLCANIC CLOUD - DERIVED PARTICLE SIZES, COLUMNAR MASS LOADINGS, AND EFFECTS ON PLANETARY ALBEDO SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EL-CHICHON AB We have made airborne measurements of spectral optical depths, radiative fluxes, and scattered radiation fields during the NASA Caribbean mission (July 7-14, 1991) to characterize the Pinatubo volcanic cloud. In this paper we report the latitudinal and spectral dependence of the volcanic cloud's optical depth. From these measurements we determine moments of the particle size distribution. The change in planetary albedo induced by the volcanic cloud is calculated for the range of measured optical depths with the objective of assessing the impact on the solar radiation budget. Mid-visible optical depths higher than 0.4 were observed, placing the Pinatubo stratospheric cloud among the thickest ever measured. The latitudinal distribution of extinction shows that by July 7, 1991 the volcanic cloud had extended to 30-degrees-N. The effective particle radius was determined to be between 0.18-mu-m and 0.35-mu-m with a corresponding columnar mass loading between 35 and 80 mg.m-2. RP VALERO, FPJ (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 12 TC 57 Z9 57 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 163 EP 166 DI 10.1029/92GL00074 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700023 ER PT J AU WINKER, DM OSBORN, MT AF WINKER, DM OSBORN, MT TI AIRBORNE LIDAR OBSERVATIONS OF THE PINATUBO VOLCANIC PLUME SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB A dual-polarization lidar aboard the NASA Electra aircraft was used in July 1991 to survey the stratospheric plume from the recent Mt. Pinatubo eruption. Many distinct layers were observed, ranging from 17 to 26 km in altitude. Peak scattering ratios of as high as 80 at 532 nm were recorded. Total particle mass of the plume 27 days after the eruption is estimated from these measurements to be on the order of 8 megatonnes, with perhaps half the original SO2 converted to aerosol at that point. C1 HUGHES STX CORP,HAMPTON,VA 23666. RP WINKER, DM (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,MAIL STOP 475,HAMPTON,VA 23665, USA. NR 9 TC 51 Z9 51 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 167 EP 170 DI 10.1029/91GL02867 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700024 ER PT J AU WINKER, DM OSBORN, MT AF WINKER, DM OSBORN, MT TI PRELIMINARY-ANALYSIS OF OBSERVATIONS OF THE PINATUBO VOLCANIC PLUME WITH A POLARIZATION-SENSITIVE LIDAR SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DEPOLARIZATION; PARTICLES AB A dual-polarization lidar aboard the NASA Electra aircraft was used in July 1991 to survey the stratospheric plume from the recent Mt. Pinatubo eruption. Both depolarizing and non-depolarizing volcanic layers were observed, ranging from 17 to 26 km in altitude. Differences in the depolarization signatures of the layers indicates differences in the composition or physical state of the particles in the layers. C1 HUGHES STX CORP,HAMPTON,VA 23666. RP WINKER, DM (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,MAIL STOP 475,HAMPTON,VA 23665, USA. NR 13 TC 35 Z9 35 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 171 EP 174 DI 10.1029/91GL02866 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700025 ER PT J AU GOLDMAN, A MURCRAY, FJ RINSLAND, CP BLATHERWICK, RD DAVID, SJ MURCRAY, FH MURCRAY, DG AF GOLDMAN, A MURCRAY, FJ RINSLAND, CP BLATHERWICK, RD DAVID, SJ MURCRAY, FH MURCRAY, DG TI MT-PINATUBO SO2 COLUMN MEASUREMENTS FROM MAUNA-LOA SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LINE PARAMETERS; BANDS AB Absorption features of the nu-1 band of SO2 have been identified in high resolution infrared solar absorption spectra recorded from Mauna Loa, Hawaii, on July 9 and 12, 1991, shortly after the arrival of the first eruption plume from the Mt. Pinatubo volcano in the Phillipines. A total SO2 vertical column amount of (5.1 +/- 0.5) x 10(16) molecules cm-2 on July 9 has been retrieved based on nonlinear least-squares spectral fittings of 9 selected SO2 absorption features with an updated set Of SO2 Spectral parameters. A SO2 total column upper limit of 0.9 x 10(16) molecules cm-2 deduced from measurements on September 20-24, 1991, is consistent with the dispersion of the SO2 cloud and the rapid conversion of the SO2 vapor into volcanic aerosol particles. C1 NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,HAMPTON,VA 23665. RP GOLDMAN, A (reprint author), UNIV DENVER,DEPT PHYS,DENVER,CO 80208, USA. NR 22 TC 24 Z9 24 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 183 EP 186 DI 10.1029/92GL00073 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700028 ER PT J AU LABITZKE, K MCCORMICK, MP AF LABITZKE, K MCCORMICK, MP TI STRATOSPHERIC TEMPERATURE INCREASES DUE TO PINATUBO AEROSOLS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EL-CHICHON; ERUPTION; MEXICO AB Northern hemisphere stratospheric temperatures at 30 and 50 mb beginning in June 1991 are compared with 20-year (1965-1984) and 26-year (1964-1989) monthly means. Significant temperature increases are shown in July, August, September, and October for latitudes from approximately 30-degrees-N to the equator. In September and October, +2-sigma to +3-sigma deviations are observed for large areas between the equator and 30-degrees-N, with temperature increases as high as +3.5-degrees-C occurring at some locations. The monthly averaged zonal mean 30-mb temperatures at 20-degrees-N in September and October were approximately 2.5-degrees-C higher than the 26-year mean, with some daily zonal mean increases of almost 3-degrees-C. Higher values occurred equatorward of 20-degrees-N. We believe these warmings are due to absorption of radiation by the new aerosols produced from the June eruptions of the volcano Pinatubo (15.1-degrees-N, 120.4-degrees-E) in the Philippines. We also expect stratospheric warmings to be occurring simultaneously at southern latitudes, especially from the equator to about 20-degrees-S, based on satellite and lidar measurements of the locations of the new aerosol layers. These localized temperature increases should decrease in magnitude and become more global as the cloud disperses globally and spreads in altitude. C1 NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,HAMPTON,VA 23665. RP LABITZKE, K (reprint author), FREE UNIV BERLIN,INST METEOROL,W-1000 BERLIN 33,GERMANY. NR 13 TC 151 Z9 156 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 207 EP 210 DI 10.1029/91GL02940 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700034 ER PT J AU HANSEN, J LACIS, A RUEDY, R SATO, M AF HANSEN, J LACIS, A RUEDY, R SATO, M TI POTENTIAL CLIMATE IMPACT OF MOUNT-PINATUBO ERUPTION SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EL-CHICHON; TEMPERATURES; AGUNG; DUST AB We use the GISS global climate model to make a preliminary estimate of Mount Pinatubo's climate impact. Assuming the aerosol optical depth is nearly twice as great as for the 1982 El Chichon eruption, the model forecasts a dramatic but temporary break in recent global warming trends. The simulations indicate that Pinatubo occurred too late in the year to prevent 1991 from becoming one of the warmest years in instrumental records, but intense aerosol cooling is predicted to begin late in 1991 and to maximize late in 1992. The predicted cooling is sufficiently large that by mid 1992 it should even overwhelm global warming associated with an El Nino that appears to be developing, but the El Nino could shift the time of minimum global temperature into 1993. The model predicts a return to record warm levels in the later 1990s. We estimate the effect of the predicted global cooling on such practical matters as the severity of the coming Soviet winter and the dates of cherry blossoming next spring, and discuss caveats which must accompany these preliminary simulations. RP HANSEN, J (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GODDARD INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA. RI Lacis, Andrew/D-4658-2012 NR 20 TC 248 Z9 253 U1 4 U2 29 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 24 PY 1992 VL 19 IS 2 BP 215 EP 218 DI 10.1029/91GL02788 PG 4 WC Geosciences, Multidisciplinary SC Geology GA HC057 UT WOS:A1992HC05700036 ER PT J AU VANESSEN, DC ANDERSON, CH FELLEMAN, DJ AF VANESSEN, DC ANDERSON, CH FELLEMAN, DJ TI INFORMATION-PROCESSING IN THE PRIMATE VISUAL-SYSTEM - AN INTEGRATED SYSTEMS PERSPECTIVE SO SCIENCE LA English DT Article ID LATERAL GENICULATE-NUCLEUS; SUPERIOR TEMPORAL SULCUS; MACAQUE MONKEY; CORTICAL CONNECTIONS; EXTRASTRIATE CORTEX; RESPONSE PROPERTIES; RHESUS-MONKEY; AREA MT; CELLS; COLOR AB The primate visual system contains dozens of distinct areas in the cerebral cortex and several major subcortical structures. These subdivisions are extensively interconnected in a distributed hierarchical network that contains several intertwined processing streams. A number of strategies are used for efficient information processing within this hierarchy. These include linear and nonlinear filtering, passage through information bottlenecks, and coordinated use of multiple types of information. In addition, dynamic regulation of information flow within and between visual areas may provide the computational flexibility needed for the visual system to perform a broad spectrum of tasks accurately and at high resolution. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. UNIV TEXAS, SCH MED, DEPT NEUROBIOL & ANAT, HOUSTON, TX 77030 USA. RP VANESSEN, DC (reprint author), CALTECH, DIV BIOL, PASADENA, CA 91125 USA. NR 62 TC 638 Z9 647 U1 7 U2 45 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JAN 24 PY 1992 VL 255 IS 5043 BP 419 EP 423 DI 10.1126/science.1734518 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HA590 UT WOS:A1992HA59000028 PM 1734518 ER PT J AU CHARLSON, RJ SCHWARTZ, SE HALES, JM CESS, RD COAKLEY, JA HANSEN, JE HOFMANN, DJ AF CHARLSON, RJ SCHWARTZ, SE HALES, JM CESS, RD COAKLEY, JA HANSEN, JE HOFMANN, DJ TI CLIMATE FORCING BY ANTHROPOGENIC AEROSOLS SO SCIENCE LA English DT Article ID GLOBAL CLOUD ALBEDO; SOUTH-AMERICAN CONTINENT; EARTHS RADIATION BUDGET; ICE-CORE RECORD; ATMOSPHERIC SULFUR; UNITED-STATES; ANTARCTIC PRECIPITATION; MARINE-PHYTOPLANKTON; IMPURITY SOURCES; WATER CLOUDS AB Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol in particular has imposed a major perturbation to this forcing. Both the direct scattering of short-wavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be - 1 to - 2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes. C1 UNIV WASHINGTON, INST ENVIRONM STUDIES, SEATTLE, WA 98195 USA. BROOKHAVEN NATL LAB, DIV ENVIRONM CHEM, UPTON, NY 11973 USA. PACIFIC NW LAB, DEPT ATMOSPHER SCI, RICHLAND, WA 99352 USA. SUNY STONY BROOK, INST TERR & PLANETARY ATMOSPHERES, STONY BROOK, NY 11794 USA. OREGON STATE UNIV, DEPT ATMOSPHER SCI, CORVALLIS, OR 97331 USA. NASA, GODDARD INST SPACE STUDIES, NEW YORK, NY 10025 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP CHARLSON, RJ (reprint author), UNIV WASHINGTON, DEPT ATMOSPHER SCI, SEATTLE, WA 98195 USA. RI Schwartz, Stephen/C-2729-2008 OI Schwartz, Stephen/0000-0001-6288-310X NR 83 TC 2116 Z9 2206 U1 99 U2 653 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 24 PY 1992 VL 255 IS 5043 BP 423 EP 430 DI 10.1126/science.255.5043.423 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA HA590 UT WOS:A1992HA59000029 PM 17842894 ER PT J AU LEE, TJ RICE, JE AF LEE, TJ RICE, JE TI ABINITIO STUDY OF THE MOLECULAR-STRUCTURE AND VIBRATIONAL-SPECTRUM OF NITRIC-ACID AND ITS PROTONATED FORMS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GAUSSIAN BASIS FUNCTIONS; ATOMIC BASIS SETS; FIRST-ROW ATOMS; GAS-PHASE; DIPOLE-MOMENT; CONTRACTION; FREQUENCIES; BANDS; WATER; HNO3 AB The equilibrium structure and infrared spectrum of HNO3 (nitric acid) and its protonated forms have been determined using double-zeta plus polarization and triple-zeta plus double polarization basis sets in conjunction with several ab initio electronic structure methods. Namely, the self-consistent field (SCF), second order Moller-Plesset perturbation theory (MP2), and the single and double excitation coupled-cluster (CCSD) methods have been used. Results using the CCSD(T) method, which includes a perturbational estimate of the effects of connected triple excitations, are also presented. Accurate energy differences have been determined by computing CCSD(T) energies using large atomic natural orbital basis sets. Four different isomers of H2NO3(4) have been investigated, and it is found that the lowest energy form of protonated nitric acid corresponds to a complex between H2O and NO2+, consistent with earlier theoretical and experimental studies. There are two isomers of the complex, differing by rotation of H2O relative to NO2+, that are very close energetically (DELTA-E < 0.5 kcal/mol), although only the planar form is found to be a minimum on the potential energy surface. The other two isomers of H2NO3+ that have been investigated both correspond to local minima on the potential energy surface and are very close in energy. These two isomers are about 20 kcal/mol less stable than the complex. The proton affinity of nitric acid is computed to be 182.5 +/- 4.0 kcal/mol, which is somewhat larger than the recent experimental estimate of Cacace et al. (168 +/- 3 kcal/mol). The binding energy of the complex is determined to be 17.3 +/- 2.0 kcal/mol. C1 IBM CORP,DIV RES,ALMADEN RES CTR,SAN JOSE,CA 95120. RP LEE, TJ (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. RI Rice, Julia/K-4928-2012; Lee, Timothy/K-2838-2012 OI Rice, Julia/0000-0001-5059-5127; NR 47 TC 71 Z9 71 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JAN 23 PY 1992 VL 96 IS 2 BP 650 EP 657 DI 10.1021/j100181a026 PG 8 WC Chemistry, Physical SC Chemistry GA HB392 UT WOS:A1992HB39200026 ER PT J AU LISK, RC AF LISK, RC TI NASA PREFERRED RELIABILITY-PRACTICES FOR DESIGN AND TEST SO PROCEEDINGS ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article; Proceedings Paper CT 1992 ANNUAL SYMP ON RELIABILITY AND MAINTAINABILITY CY JAN 21-23, 1992 CL LAS VEGAS, NV SP IEEE, INST IND ENGINEERS, AMER SOC QUAL CONTROL, SYSTEM SAFETY SOC, SOC RELIAB ENGINEERS, SOC LOGIST ENGINEERS DE MAINTAINABILITY; SYSTEMS ENGINEERING; ASSURANCE; ANALYSIS; TEST AB The diversity and relative autonomy of the NASA Field Centers fosters a situation where unnecessary repetition of design effort and the danger of loss of design techniques used for high reliability hardware is Possible. Intercenter communication of technical approaches that have contributed to mission success reduces the chance for duplication of technical effort, provides a mechanism for retaining NASA's corporate knowledge in reliability, and promotes closer teamwork between the engineering and assurance communities. NASA HQ established the NASA R & M Steering Committee (R & MSC) comprised of membership from each NASA Field Center. The primary charter of the R & MSC is to obtain, record, and share the best design practices that NASA has applied to successful space flight programs and current design considerations (guidelines) that should enhance flight reliability on emerging programs. The practices and guidelines are being assembled in a living document for distribution to NASA Centers and the aerospace community. The document will be updated annually with additional practices and guidelines as contributions from the Centers are reviewed and approved by the R&MSC. Practices and guidelines are not requirements but rather a means of sharing procedures and techniques that a given Center and the R & MSC together feel have strong technical merit and application to the design of space-related equipment. Many of these practices and guidelines also will have application to ground-based equipment, but the primary thrust is for space flight applications. RP LISK, RC (reprint author), NASA HEADQUARTERS,CODE QR,600 INDEPENDENCE AVE SW,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0149-144X J9 P ANNU REL MAINT SYM JI Proc. Annu. Reliab. Maintainab. Symp. PD JAN 21 PY 1992 IS SYM BP 7 EP 11 DI 10.1109/ARMS.1992.187793 PG 5 WC Engineering, Multidisciplinary; Engineering, Industrial SC Engineering GA HQ114 UT WOS:A1992HQ11400003 ER PT J AU WHITE, AL AF WHITE, AL TI RELIABILITY PREDICTION FOR A CLASS OF HIGHLY RELIABLE DIGITAL-SYSTEMS SO PROCEEDINGS ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article; Proceedings Paper CT 1992 ANNUAL SYMP ON RELIABILITY AND MAINTAINABILITY CY JAN 21-23, 1992 CL LAS VEGAS, NV SP IEEE, INST IND ENGINEERS, AMER SOC QUAL CONTROL, SYSTEM SAFETY SOC, SOC RELIAB ENGINEERS, SOC LOGIST ENGINEERS DE RELIABILITY PREDICTION; RECONFIGURABLE SYSTEMS; SEMI-MARKOV MODELS; MODEL REDUCTION; ERROR BOUNDS AB Semi-Markov processes have proved to be an effective and convenient tool to construct models of systems that achieve reliability by redundancy and reconfiguration. These models are able to depict complex system architectures and to capture the dynamics of fault arrival and system recovery. A disadvantage of this approach is that the models can be extremely large, which poses both a model construction and a computational problem. Results are needed that permit a reduction in model size. Because these systems are used in critical applications where failure can be expensive, there must be analytically derived bounds for the error produced by the model reduction techniques. This paper presents three theorems which show that the reliability of a popular class of systems can be computed using small and simple models. These theorems give error bounds for three model reduction and simplification techniques. The error bounds are given in terms of readily available system parameters. RP WHITE, AL (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, 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 SN 0149-144X J9 P ANNU REL MAINT SYM JI Proc. Annu. Reliab. Maintainab. Symp. PD JAN 21 PY 1992 IS SYM BP 12 EP 18 DI 10.1109/ARMS.1992.187794 PG 7 WC Engineering, Multidisciplinary; Engineering, Industrial SC Engineering GA HQ114 UT WOS:A1992HQ11400004 ER PT J AU FOSTER, WM AF FOSTER, WM TI THERMAL VERIFICATION TESTING OF COMMERCIAL PRINTED-CIRCUIT BOARDS FOR SPACEFLIGHT SO PROCEEDINGS ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article; Proceedings Paper CT 1992 ANNUAL SYMP ON RELIABILITY AND MAINTAINABILITY CY JAN 21-23, 1992 CL LAS VEGAS, NV SP IEEE, INST IND ENGINEERS, AMER SOC QUAL CONTROL, SYSTEM SAFETY SOC, SOC RELIAB ENGINEERS, SOC LOGIST ENGINEERS DE INFRARED SCANNERS; THERMAL VACUUM TESTS; THERMAL CYCLING TESTS; BURN-IN AB This paper discusses a method developed to verify commercial printed-circuit boards for a shuttle orbital flight. The Space Acceleration Measurement System (SAMS) Project used this method first with great success. The test sequence is based on early fault detection, desire to test the final assembly, and integration with other verification testing. A component thermal screening test is performed first to force flaws in design, workmanship, parts, processes, and materials into observable failures. Then temperature definition tests are performed that consist of infrared scanning, thermal vacuum testing, and preliminary thermal operational testing. Only the engineering unit is used for temperature definition testing, but the preliminary thermal operational testing is performed on the flight unit after the temperature range has been defined. In the sequence of testing, vibration testing is performed next, but most vibration failures cannot be detected without subsequent temperature cycling. Finally, final assembly testing is performed to simulate a shuttle flight. An abbreviated thermal screening test is performed as a check after the vibration test, and then a complete thermal operational test is performed. The final assembly test finishes up with a burn-in of 100 hours of trouble-free operation. Verification is successful when all the components and final assemblies have passed each test satisfactorily. This method has been very successful in verifying that commercial printed-circuit boards will survive in the shuttle environment. RP FOSTER, WM (reprint author), NASA,LEWIS RES CTR,21000 BROOKPARK RD,CLEVELAND,OH 44135, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0149-144X J9 P ANNU REL MAINT SYM JI Proc. Annu. Reliab. Maintainab. Symp. PD JAN 21 PY 1992 IS SYM BP 189 EP 195 DI 10.1109/ARMS.1992.187821 PG 7 WC Engineering, Multidisciplinary; Engineering, Industrial SC Engineering GA HQ114 UT WOS:A1992HQ11400031 ER PT J AU RODNEY, GA AF RODNEY, GA TI FUTURE-ROLE OF NASA R-AND-M ASSURANCE IN SPACE-FLIGHT EXPLORATION SO PROCEEDINGS ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article; Proceedings Paper CT 1992 ANNUAL SYMP ON RELIABILITY AND MAINTAINABILITY CY JAN 21-23, 1992 CL LAS VEGAS, NV SP IEEE, INST IND ENGINEERS, AMER SOC QUAL CONTROL, SYSTEM SAFETY SOC, SOC RELIAB ENGINEERS, SOC LOGIST ENGINEERS DE DEEP-SPACE; NONDESTRUCTIVE EVALUATION; INTERFACE ANALYSIS; MAINTAINABILITY RP RODNEY, GA (reprint author), NASA,OFF SAFETY & MISSION QUAL,600 INDEPENDENCE AVE SW,WASHINGTON,DC 20546, 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 SN 0149-144X J9 P ANNU REL MAINT SYM JI Proc. Annu. Reliab. Maintainab. Symp. PD JAN 21 PY 1992 IS SYM BP 239 EP 240 DI 10.1109/ARMS.1992.187828 PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial SC Engineering GA HQ114 UT WOS:A1992HQ11400038 ER PT J AU IVERSON, DL AF IVERSON, DL TI AUTOMATIC TRANSLATION OF DIGRAPH TO FAULT-TREE MODELS SO PROCEEDINGS ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article; Proceedings Paper CT 1992 ANNUAL SYMP ON RELIABILITY AND MAINTAINABILITY CY JAN 21-23, 1992 CL LAS VEGAS, NV SP IEEE, INST IND ENGINEERS, AMER SOC QUAL CONTROL, SYSTEM SAFETY SOC, SOC RELIAB ENGINEERS, SOC LOGIST ENGINEERS DE DIGRAPH; FAULT-TREE; TRANSLATION; CUT SET; DIAGNOSIS AB This paper presents a technique for converting digraph models, including those models containing cycles, to a fault-tree format. A computer program has been developed which automatically performs this translation using an object-oriented representation of the models. The fault-trees resulting from translations can be used for fault-tree analysis and diagnosis. Programs to calculate fault-tree and digraph cut sets and perform diagnosis with fault-tree models have also been developed. The digraph to fault-tree translation system has been successfully tested on several digraphs of varying size and complexity. Details of some representative translation problems are presented later in this paper. Most of the computation performed by the program is dedicated to finding minimal cut sets for digraph nodes in order to break cycles in the digraph. Fault-trees produced by the translator have been successfully used with NASA's Fault-Tree Diagnosis System (FTDS) to produce automated diagnostic systems. RP IVERSON, DL (reprint author), NASA,AMES RES CTR,MAIL STOP 244-4,MOFFETT FIELD,CA 94035, USA. NR 0 TC 8 Z9 8 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0149-144X J9 P ANNU REL MAINT SYM JI Proc. Annu. Reliab. Maintainab. Symp. PD JAN 21 PY 1992 IS SYM BP 354 EP 362 DI 10.1109/ARMS.1992.187848 PG 9 WC Engineering, Multidisciplinary; Engineering, Industrial SC Engineering GA HQ114 UT WOS:A1992HQ11400058 ER PT J AU PATTERSONHINE, FA DUGAN, JB AF PATTERSONHINE, FA DUGAN, JB TI MODULAR TECHNIQUES FOR DYNAMIC FAULT-TREE ANALYSIS SO PROCEEDINGS ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article; Proceedings Paper CT 1992 ANNUAL SYMP ON RELIABILITY AND MAINTAINABILITY CY JAN 21-23, 1992 CL LAS VEGAS, NV SP IEEE, INST IND ENGINEERS, AMER SOC QUAL CONTROL, SYSTEM SAFETY SOC, SOC RELIAB ENGINEERS, SOC LOGIST ENGINEERS DE FAULT TREE; FAULT TOLERANT SYSTEM; SEQUENCE DEPENDENCIES; OBJECT-ORIENTED PROGRAMMING; FTPP (FAULT TOLERANT PARALLEL PROCESSOR) AB Current approaches used to assess the dependability of complex systems such as Space Station Freedom and the Air Traffic Control System are incapable of handling the size and complexity of these highly integrated designs. A new technique for modeling such systems is described which is built upon current techniques in Markov theory and combinatorial analysis. It enables the development of a hierarchical representation of system behavior which is more flexible than either technique alone. A solution strategy is also described which is based on an object-oriented approach to model representation and evaluation. The technique is virtually transparent to the user since the fault tree models can be built graphically and the objects defined automatically. The tree modularization procedure allows the two model types, Markov and combinatoric, to coexist and does not require that the entire fault tree be translated to a Markov chain for evaluation. This effectively reduces the size of the Markov chain required and enables solutions with less truncation, making analysis of longer mission times possible. Using the FTPP (Fault Tolerant Parallel Processor) as an example, a model is built and solved for a specific mission scenario and the solution approach is illustrated in detail. RP PATTERSONHINE, FA (reprint author), NASA,AMES RES CTR,MS 244-4,MOFFETT FIELD,CA 94035, USA. NR 0 TC 3 Z9 7 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0149-144X J9 P ANNU REL MAINT SYM JI Proc. Annu. Reliab. Maintainab. Symp. PD JAN 21 PY 1992 IS SYM BP 363 EP 369 DI 10.1109/ARMS.1992.187849 PG 7 WC Engineering, Multidisciplinary; Engineering, Industrial SC Engineering GA HQ114 UT WOS:A1992HQ11400059 ER PT J AU BAVUSO, SJ DUGAN, JB AF BAVUSO, SJ DUGAN, JB TI HIREL - RELIABILITY AVAILABILITY INTEGRATED WORKSTATION TOOL SO PROCEEDINGS ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article; Proceedings Paper CT 1992 ANNUAL SYMP ON RELIABILITY AND MAINTAINABILITY CY JAN 21-23, 1992 CL LAS VEGAS, NV SP IEEE, INST IND ENGINEERS, AMER SOC QUAL CONTROL, SYSTEM SAFETY SOC, SOC RELIAB ENGINEERS, SOC LOGIST ENGINEERS DE HIREL; HARP; AVAILABILITY; FAULT-TOLERANCE; GRAPHICS AB The HiRel software tool is described and demonstrated by application to the mission avionics subsystem of the Advanced System Integration Demonstrations (ASID) system that utilizes the PAVE PILLAR approach. HiRel marks another accomplishment toward the goal of producing a totally integrated computer-aided design (CAD) workstation design capability. Since a reliability engineer generally represents a reliability model graphically before he can solve it, the use of a graphical input description language increases productivity and decreases the incidence of error. The graphical postprocessor module, HARPO, makes it possible for reliability engineers to quickly analyze huge amounts of reliability/availability data to observe trends due to exploratory design changes. The addition of several powerful HARP modeling engines provide the user with a reliability/availability modeling capability for a wide range of system applications all integrated under a common interactive graphical input/output capability. RP BAVUSO, SJ (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 478,HAMPTON,VA 23665, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0149-144X J9 P ANNU REL MAINT SYM JI Proc. Annu. Reliab. Maintainab. Symp. PD JAN 21 PY 1992 IS SYM BP 491 EP 500 DI 10.1109/ARMS.1992.187870 PG 10 WC Engineering, Multidisciplinary; Engineering, Industrial SC Engineering GA HQ114 UT WOS:A1992HQ11400080 ER PT J AU WEBSTER, KL SUNG, CC AF WEBSTER, KL SUNG, CC TI MODE-MEDIUM INSTABILITY AND ITS CORRECTION WITH A GAUSSIAN-REFLECTIVITY MIRROR SO APPLIED OPTICS LA English DT Article DE MODE-MEDIUM INSTABILITY; GAUSSIAN-REFLECTIVITY MIRROR; RESONATOR; FAST FOURIER TRANSFORM ID CANCELING EDGE WAVES; UNSTABLE RESONATORS; LASER; LIMP AB A high-power CO2 laser beam is known to deteriorate after a few microseconds because of a mode-medium instability (MMI) that results from an intensity-dependent heating rate that is related to the vibrational-to-translational decay of the upper and lower CO2 lasing levels. An iterative numerical technique has been developed to model the time evolution of the beam as it is affected by the MMI. The technique is used to study the MMI in an unstable CO2 resonator with a hard-edge output mirror for different parameters, e.g., the Fresnel number and the gas density. The results show that the mode of the hard-edge unstable resonator deteriorates because of the diffraction ripples in the mode. We use a Gaussian-reflectivity mirror to correct the MMI. This mirror produces a smoother intensity profile, which significantly reduces the effects of the MMI. Quantitative results on the peak density variation and beam quality are presented. RP WEBSTER, KL (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812, USA. NR 26 TC 2 Z9 2 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JAN 20 PY 1992 VL 31 IS 3 BP 319 EP 328 PG 10 WC Optics SC Optics GA HB063 UT WOS:A1992HB06300004 PM 20717409 ER PT J AU LIN, TL GEORGE, T JONES, EW KSENDZOV, A HUBERMAN, ML AF LIN, TL GEORGE, T JONES, EW KSENDZOV, A HUBERMAN, ML TI ELEMENTAL BORON-DOPED P+-SIGE LAYERS GROWN BY MOLECULAR-BEAM EPITAXY FOR INFRARED DETECTOR APPLICATIONS SO APPLIED PHYSICS LETTERS LA English DT Article AB SiGe/Si heterojunction internal photoemission (HIP) detectors have been fabricated utilizing molecular beam epitaxy of p+-SiGe layers on p--Si substrates. Elemental boron from a high-temperature effusion cell was used as the dopant source during molecular beam epitaxy (MBE) growth, and high doping concentrations (> 5 x 10(20) cm-3) have been achieved. Strong infrared absorption, mainly by free-carrier absorption, was observed for the degenerately doped SiGe layers. The use of elemental boron as the dopant source allows a low MBE growth temperature (350-degree-C), resulting in improved crystalline quality and smooth surface morphology of the Si0.7Ge0.3 layers. Nearly ideal thermionic emission dark current characteristics have been obtained. Photoresponse of the HIP detectors in the long-wavelength infrared regime has been demonstrated. RP LIN, TL (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECTR,PASADENA,CA 91109, USA. NR 9 TC 27 Z9 28 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 20 PY 1992 VL 60 IS 3 BP 380 EP 383 DI 10.1063/1.106663 PG 4 WC Physics, Applied SC Physics GA HA036 UT WOS:A1992HA03600040 ER PT J AU KEENAN, FP HARRA, LK AGGARWAL, KM FEIBELMAN, WA AF KEENAN, FP HARRA, LK AGGARWAL, KM FEIBELMAN, WA TI AL-II EMISSION-LINE STRENGTHS IN LOW-DENSITY ASTROPHYSICAL PLASMAS SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATOMIC PROCESSES; PLANETARY NEBULAE, INDIVIDUAL (NGC 7027); STARS, INDIVIDUAL (RR-TELESCOPII) ID ELECTRON-IMPACT EXCITATION; OSCILLATOR-STRENGTHS; TRANSITIONS; INTERCOMBINATION; FORBIDDEN; PROGRAM AB Theoretical Al II emission line ratios, determined using electron impact excitation rates calculated with the R-matrix code, are presented for R = I(3s21S-3s3p3P2)/I(3s21S-3s3p3P1) = I(2660 angstrom)/I(2669 angstrom). This ratio is a useful electron density diagnostic for N(e) greater-than-or-equal-to 10(2) cm-3, its use being illustrated for the planetary nebula NGC 7027 and the symbiotic star RR Tel. C1 QUEENS UNIV BELFAST,DEPT APPL MATH & THEORET PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. UNIV DELHI,DEPT PHYS & ASTROPHYS,DELHI 110007,INDIA. RP KEENAN, FP (reprint author), QUEENS UNIV BELFAST,DEPT PURE & APPL PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. OI Harra, Louise/0000-0001-9457-6200 NR 14 TC 9 Z9 9 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 20 PY 1992 VL 385 IS 1 BP 375 EP 377 DI 10.1086/170946 PN 1 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GZ903 UT WOS:A1992GZ90300037 ER PT J AU HARTMAN, RC BERTSCH, DL FICHTEL, CE HUNTER, SD KANBACH, G KNIFFEN, DA KWOK, PW LIN, YC MATTOX, JR MAYERHASSELWANDER, HA MICHELSON, PF VONMONTIGNY, C NEL, HI NOLAN, PL PINKAU, K ROTHERMEL, H SCHNEID, E SOMMER, M SREEKUMAR, P THOMPSON, DJ AF HARTMAN, RC BERTSCH, DL FICHTEL, CE HUNTER, SD KANBACH, G KNIFFEN, DA KWOK, PW LIN, YC MATTOX, JR MAYERHASSELWANDER, HA MICHELSON, PF VONMONTIGNY, C NEL, HI NOLAN, PL PINKAU, K ROTHERMEL, H SCHNEID, E SOMMER, M SREEKUMAR, P THOMPSON, DJ TI DETECTION OF HIGH-ENERGY GAMMA-RADIATION FROM QUASAR 3C-279 BY THE EGRET TELESCOPE ON THE COMPTON-GAMMA-RAY-OBSERVATORY SO ASTROPHYSICAL JOURNAL LA English DT Article DE GAMMA-RAYS, OBSERVATIONS; QUASARS, INDIVIDUAL, 3C-279 ID ACTIVE GALACTIC NUCLEI; ASTRONOMY; CONTINUUM; EMISSION; OUTBURST; RADIO AB Intense gamma radiation has been observed from the direction of the quasar 3C 279 throughout the energy range from 30 MeV to over 5 GeV by the Energetic Gamma Ray Experiment Telescope (EGRET) during the period 1991 June 15-28. Its spectrum is well represented by a photon differential power-law exponent of 2.0 +/- 0.1, with a photon intensity above 100 MeV of (2.8 +/- 0.4) x 10(-6) cm-2 s-1. 3C 279 was not detected by either of the earlier high-energy gamma-ray telescopes SAS 2 or COS B. For E > 100 MeV, the 2-sigma upper limits were 1.0 x 10(-6) cm-2 s-1 in 1973 from the SAS 2 observations and 0.3 x 10(-6) cm-2 s-1 for the combined 1976, 1978, and 1980 COS B observations. Hence, there has been a large increase in high-energy gamma-ray intensity relative to the earlier times, as there has been in the radio, infrared, optical, and X-ray ranges. This source is the most distant and by far the most luminous gamma-ray source yet detected. C1 MAX PLANCK INST EXTRATERRESTR PHYS,W-8046 GARCHING,GERMANY. STANFORD UNIV,HANSEN EXPTL PHYS LAB,STANFORD,CA 94305. NASA,GODDARD SPACE FLIGHT CTR,COMP SCI CORP,GRO SCI SUPPORT CTR,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. GRUMMAN AEROSP CORP,BETHPAGE,NY 11714. HAMPDEN SYDNEY COLL,HAMPDEN SYDNEY,VA 23943. RP HARTMAN, RC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 662,GREENBELT,MD 20771, USA. RI Nolan, Patrick/A-5582-2009; Hunter, Stanley/D-2942-2012; Thompson, David/D-2939-2012 OI Thompson, David/0000-0001-5217-9135 NR 49 TC 201 Z9 202 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 20 PY 1992 VL 385 IS 1 BP L1 EP L4 DI 10.1086/186263 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GZ906 UT WOS:A1992GZ90600001 ER PT J AU MORROW, BA HOLT, MR STARCEVIC, VP KEIL, LC SEVERS, WB AF MORROW, BA HOLT, MR STARCEVIC, VP KEIL, LC SEVERS, WB TI MECHANISM OF DELAYED INTRACRANIAL HYPERTENSION AFTER CEREBROVENTRICULAR INFUSIONS IN CONSCIOUS RATS SO BRAIN RESEARCH LA English DT Article DE INTRACRANIAL PRESSURE; CEREBROSPINAL FLUID PRESSURE; ANIMAL MODEL; CEREBROSPINAL FLUID DYNAMICS; ACETAZOLAMIDE; OUABAIN ID CEREBROSPINAL-FLUID PRESSURE; ANGIOTENSIN; RESISTANCE; ABSORPTION AB Prior studies showed that cerebroventricular infusions of artificial cerebrospinal fluid, 8-mu-l/min for 10 min, followed by a 10 min rest and a 24 h infusion of 0.5-mu-l/min, raised cerebrospinal fluid pressure (CSFp) of conscious, unrestrained rats after about 2 h. Here, we report that the 10 min infusion alone evoked a delayed, prolonged rise in CSFp. Pressure during the infusion itself rose and recovered quickly, as is usually reported. Pressure/volume tests, used to calculate resistance to outflow (R(o)) and compliance (C), revealed that infusions increased R(o) and decreased C, after a delay (P < 0.05). The rise in CSFp after infusion was blocked by pretreatment with acetazolamide + ouabain (P < 0.05), but the delayed changes in R(o) and C were unaffected. We suggest that the 10 min infusion of a sterile, balanced salt solution has a primary effect that increases R(o); as CSF synthesis continues, C is exhausted and the delayed rise in CSFp ensues. This non-traumatic method of raising CSFp may be a useful method to study intracranial fluid dynamics. C1 PENN STATE UNIV,MILTON S HERSHEY MED CTR,COLL MED,DEPT PHARMACOL,HERSHEY,PA 17033. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. FU FIC NIH HHS [TW03743] NR 25 TC 8 Z9 8 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-8993 J9 BRAIN RES JI Brain Res. PD JAN 20 PY 1992 VL 570 IS 1-2 BP 218 EP 224 DI 10.1016/0006-8993(92)90584-V PG 7 WC Neurosciences SC Neurosciences & Neurology GA HB005 UT WOS:A1992HB00500029 PM 1617414 ER PT J AU TUCKER, CJ AF TUCKER, CJ TI RELATING SMMR 37 GHZ POLARIZATION DIFFERENCE TO PRECIPITATION AND ATMOSPHERIC CARBON-DIOXIDE CONCENTRATION - A REAPPRAISAL SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID VEGETATION INDEX; AVHRR DATA; COMPARING SMMR; SAHEL; PRODUCTIVITY; CO2; RAINFALL; DESERT; AFRICA AB The relations of Scanning Multi-channel Microwave Radiometer (SMMR) 37 GHz polarization difference to precipitation and atmospheric carbon dioxide (CO2) concentrations are reviewed. Annual precipitation data, a surrogate for green leaf vegetation density, are compared with the coincident SMMR 37 GHz polarization difference from arid and semi-arid West Africa for 1982-85. The SMMR 37 GHz polarization difference was found to be poorly correlated with precipitation in arid and semi-arid zones, contrary to previous reports. Coincident SMMR 37 GHz polarization difference and atmospheric CO2 concentration data from July 1981 to June 1983 are also reviewed. Previously suggested relations of the SMMR 37 GHz polarization difference to atmospheric CO2 concentrations were found to be heavily biased by winter conditions in the Northern Hemisphere. The use of the SMMR 37 GHz polarization difference for determining green leaf vegetation density, net primary production, atmospheric CO2 draw-down and related processes is questioned. RP TUCKER, CJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,TERR PHYS LAB,CODE 923,GREENBELT,MD 20771, USA. NR 32 TC 9 Z9 9 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD JAN 20 PY 1992 VL 13 IS 2 BP 177 EP 191 PG 15 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA HD268 UT WOS:A1992HD26800003 ER PT J AU BREST, CL ROSSOW, WB AF BREST, CL ROSSOW, WB TI RADIOMETRIC CALIBRATION AND MONITORING OF NOAA AVHRR DATA FOR ISCCP SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID DATA SET; SATELLITE-OBSERVATIONS; SURFACE REFLECTANCE; CLIMATE-RESEARCH; SOLAR-RADIATION; VEGETATION; ALBEDO; METEOSAT; VARIABILITY; SPACECRAFT AB This paper describes the methodology developed to monitor the radiometric calibration of NOAA AVHRR data and to normalize succeeding polar orbiters for the International Satellite Cloud Climatology Project (ISCCP). Results are presented for NOAA-7, -8, and -9 Channel 1 (visible) data and briefly for Channel 4 (thermal infrared) in an appendix. The successful normalization of NOAA-8 and NOAA-9 to NOAA-7 allows the ISCCP calibration standard to be maintained over time. A correction for the degradation of NOAA-9 data and an absolute calibration for the entire ISCCP dataset are presented. RP BREST, CL (reprint author), NASA,GODDARD SPACE FLIGHT CTR,INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA. RI Rossow, William/F-3138-2015 NR 45 TC 90 Z9 91 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD JAN 20 PY 1992 VL 13 IS 2 BP 235 EP 273 PG 39 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA HD268 UT WOS:A1992HD26800006 ER PT J AU KIMES, DS HOLBEN, BN AF KIMES, DS HOLBEN, BN TI EXTRACTING SPECTRAL ALBEDO FROM NOAA-9 AVHRR MULTIPLE VIEW DATA USING AN ATMOSPHERIC CORRECTION PROCEDURE AND AN EXPERT SYSTEM SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID REFLECTANCE FACTOR DISTRIBUTIONS; HEMISPHERICAL REFLECTANCE; COVER TYPES; SAHEL; NADIR AB A 100 km x 200 km region of the Sahelian zone of Africa was chosen as the place to demonstrate a new method of extracting hemispherical reflectance (albedo) from directional satellite data. Five NOAA-9 AVHRR daytime scenes in band 1 (0.58-0.68-mu-m) were corrected for atmospheric variations to give the directional reflectances at the ground level. Using a stratification of the Gao region of Mali (Hiernaux 1989) based on soil texture, satellite data for homogeneous areas were selected. The number of view directions and the orientation of these varied because of the variable cloud cover and the changing orientation of the scanning radiometer with each overpass. These data were used in a knowledge-based expert system called VEG. This system is designed to handle a wide variety of kinds of input data. It contains an array of different techniques for inferring hemispherical reflectance. VEG accepted the spectral directional reflectance data, determined the best techniques for inferring spectral hemispherical reflectance, applied these to the selected sites and provided a rigorous estimate of the accuracy of the inference. VEG made all decisions and inferences using the input reflectance data and internal knowledge bases. The calculated directional reflectance factors at ground level were very similar to ground measurements reported in the literature. Furthermore, it was clear that a single nadir observation technique was always less accurate for estimating hemispherical reflectance than VEG using multiple view angles. The mean errors of the hemispherical reflectance of the entire region using VEG with multiple view angles and the direct nadir technique were 3 and 10 per cent, respectively, where the errors of the individual homogeneous areas were weighted by their relative sizes. RP KIMES, DS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,BIOSPHER SCI BRANCH,GREENBELT,MD 20771, USA. NR 26 TC 13 Z9 13 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD JAN 20 PY 1992 VL 13 IS 2 BP 275 EP 289 PG 15 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA HD268 UT WOS:A1992HD26800007 ER PT J AU ORMSBY, JP AF ORMSBY, JP TI EVALUATION OF NATURAL AND MAN-MADE FEATURES USING LANDSAT TM DATA SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID THEMATIC MAPPER AB Landsat-5 Thematic Mapper (TM) data of a subscene of Washington, D.C., were used to distinguish natural and man-made surfaces through analysis of their spectral response. Such information is needed to create and update geographical data bases at the national, regional and local levels. A quantitative measure of the separability and thus the ability to separate various surface features was calculated using the quantity known as divergence (D), a measure of the dissimilarity between two distributions. A general grouping of surface classes (nine) and a more specific set of classes (21), derived from the nine general classes, were studied. Discrimination between class pairs which were derived from a common class (such as, grass, mixed woods, pine woods, deciduous woods from the vegetation class) were surprisingly good. The asphalt and residential classes were the most difficult to separate/discriminate. The thermal band, TM band 6 (10.4-12.5-mu-m) was found to improve the separability when replacing a visible band, but decreased the separability when included with the middle-infrared bands. RP ORMSBY, JP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HYDROSPHER PROC LAB,HYDROL SCI BRANCH,GREENBELT,MD 20771, USA. NR 21 TC 9 Z9 9 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD JAN 20 PY 1992 VL 13 IS 2 BP 303 EP 318 PG 16 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA HD268 UT WOS:A1992HD26800009 ER PT J AU WANG, PH MCCORMICK, MP CHU, WP LENOBLE, J NAGATANI, RM CHANIN, ML BARNES, RA SCHMIDLIN, F ROWLAND, M AF WANG, PH MCCORMICK, MP CHU, WP LENOBLE, J NAGATANI, RM CHANIN, ML BARNES, RA SCHMIDLIN, F ROWLAND, M TI SAGE-II STRATOSPHERIC DENSITY AND TEMPERATURE RETRIEVAL EXPERIMENT SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OZONE MEASUREMENTS; INVERSION; AEROSOL; EXTINCTION; ALGORITHM; PROFILES; REGION AB This paper describes a stratospheric density and temperature retrieval experiment based on the solar occultation measurement of the Stratospheric Aerosol and Gas Experiment (SAGE II). The entire retrieval analysis involves two inversion steps: the vertical structure inversion, which derives the profile of local atmospheric extinction from SAGE II limb optical depth data, and the species inversion, which inverts the concentration of air molecules, aerosols, ozone, and nitrogen dioxide from the derived atmospheric extinction at five SAGE II short wavelengths (0.385, 0.448, 0.453, 0.525, and 0.600-mu-m). The inversion schemes for these steps are Twomey's (1975) modification of Chahine's nonlinear inversion algorithm and the Levenberg-Marquardt nonlinear least squares method, respectively. The derived density profile is then used to infer the temperature distribution, assuming that the atmosphere is in hydrostatic equilibrium and obeys the ideal gas law. The retrieval analysis is illustrated in detail by using a SAGE II measurement event that occurred on September 15, 1987 (43.6-degrees-N, 4.1-degrees-W). An estimate of the error associated with the retrieved molecular density and temperature profiles based on the propagation of the instrument measurement error, the reference altitude error, and an assigned 10% error to the pressure at the top measurement level is also provided. The temperature profiles retrieved from the SAGE II observations are compared with near-coincident. in both time and space, French Rayleigh lidar and NASA Wallops Flight Facility rocket datasonde soundings as well as the National Meteorological Center (NMC) data analyses. The results indicate that the mean SAGE II temperature agrees with the mean lidar measurement to within 2-degrees-C at altitudes from 30.5 to 52.5 km. The SAGE II and datasonde observations agree to within about 4-degrees-C in approximately the same altitude region. The mean temperature difference between the SAGE II and NMC analyses are, on average, about 1-degrees, 4-degrees, 2-degrees, and 3-degrees-C at the standard pressure levels of 10, 5, 2, and 1 mbar, respectively. C1 CHEMAL INC, POB 44, WALLOPS ISL, VA 23337 USA. SCI & TECHNOL CORP, HAMPTON, VA USA. UNIV SCI & TECH LILLE, OPT ATMOSPHER LAB, LILLE, FRANCE. ST SYST CORP STX, HAMPTON, VA USA. NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23665 USA. NOAA, NATL WEATHER SERV, NATL METEOROL CTR, WASHINGTON, DC 20233 USA. CNRS, SERV AERON, F-91370 VERRIERES BUISSON, FRANCE. NASA, GODDARD SPACE FLIGHT CTR, WALLOPS FLIGHT FACIL, WALLOPS ISL, VA USA. NR 37 TC 18 Z9 19 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JAN 20 PY 1992 VL 97 IS D1 BP 843 EP 863 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HA087 UT WOS:A1992HA08700002 ER PT J AU MICHELANGELI, DV ALLEN, M YUNG, YL SHIA, RL CRISP, D ELUSZKIEWICZ, J AF MICHELANGELI, DV ALLEN, M YUNG, YL SHIA, RL CRISP, D ELUSZKIEWICZ, J TI ENHANCEMENT OF ATMOSPHERIC RADIATION BY AN AEROSOL LAYER SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DISCRETE-ORDINATE METHOD; EL-CHICHON; SCATTERING; ERUPTION; CLOUD AB The presence of a stratospheric haze layer may produce increases in both the actinic flux and the irradiance below this layer. Such haze layers result from the injection of aerosol-forming material into the stratosphere by volcanic eruptions. Simple heuristic arguments show that the increase in flux below the haze layer, relative to a clear sky case, is a consequence of "photon trapping." We explore the magnitude of these flux perturbations, as a function of aerosol properties and illumination conditions, with a new radiative transfer model that can accurately compute fluxes in an inhomogeneous atmosphere with nonconservative scatterers having arbitrary phase function. One calculated consequence of the El Chichon volcanic eruption is an increase in the midday surface actinic flux at 20-degrees-N latitude, summer, by as much as 45% at 2900 angstrom. This increase in flux in the UV-B wavelength range was caused entirely by aerosol scattering, without any reduction in the overhead ozone column. C1 CALTECH, JET PROP LAB, DIV EARTH & SPACE SCI, PASADENA, CA 91109 USA. NR 27 TC 44 Z9 44 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JAN 20 PY 1992 VL 97 IS D1 BP 865 EP 874 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HA087 UT WOS:A1992HA08700003 PM 11538387 ER PT J AU ENGLAND, MN FERRARE, RA MELFI, SH WHITEMAN, DN CLARK, TA AF ENGLAND, MN FERRARE, RA MELFI, SH WHITEMAN, DN CLARK, TA TI ATMOSPHERIC WATER-VAPOR MEASUREMENTS - COMPARISON OF MICROWAVE RADIOMETRY AND LIDAR SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RAMAN LIDAR; PATH-DELAY; GEODESY; LIQUID AB The NASA/GSFC Crustal Dynamics Project microwave water vapor radiometer (J03) is evaluated in terms of measurements of the integrated precipitable water vapor content of a particular column of the troposphere. The measurements were taken during the Atmospheric Moisture Intercomparison Study (ATMIS) held at Wallops Island, Virginia, during April 1989. Various water vapor sensing instruments were used during ATMIS, including radiometers, radiosondes, and the NASA/GSFC Raman lidar. Comparisons between water vapor measurements by the radiometer and the lidar yielded a correlation coefficient of 0.998 and rms differences for three nights of -0.2 +/- 0.2 mm (April 11-12, 1989), -0.8 +/- 0.5 mm (April 16-17, 1989), and -0.4 +/- 0.3 mm (April 17-18, 1989). The integrated precipitable water vapor measurements for these three nights were approximately 5, 10, and 21 mm, respectively. The first two periods bad clear meteorological conditions, while clouds were present during the third period. The lidar results during the third period are augmented with radiosonde measurements above the cloud base. This study shows that the radiometer provides accurate, continuous measurements of the water vapor integrated through the depth of the atmosphere. C1 INTERFEROMETR INC, VIENNA, VA USA. UNIV SPACE RES ASSOC, WASHINGTON, DC USA. NASA, GODDARD SPACE FLIGHT CTR, ATMOSPHERES LAB, GREENBELT, MD 20771 USA. NASA, GODDARD SPACE FLIGHT CTR, TERR PHYS LAB, GREENBELT, MD 20771 USA. NR 35 TC 23 Z9 26 U1 2 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JAN 20 PY 1992 VL 97 IS D1 BP 899 EP 916 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HA087 UT WOS:A1992HA08700006 ER PT J AU PROFFITT, MH SOLOMON, S LOEWENSTEIN, M AF PROFFITT, MH SOLOMON, S LOEWENSTEIN, M TI COMPARISON OF 2-D MODEL SIMULATIONS OF OZONE AND NITROUS-OXIDE AT HIGH-LATITUDES WITH STRATOSPHERIC MEASUREMENTS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Note ID ANTARCTIC STRATOSPHERE; MIDDLE ATMOSPHERE; NUMERICAL-MODEL; WINTER; TRANSPORT; HOLE; CH4; N2O AB A linear reference relationship between O3 and N2O has been used to estimate polar winter O3 loss from aircraft data taken in the lower stratosphere; Here we evaluate this relationship at high latitudes by comparing it with a two-dimensional (2-D) model simulation and with NIMBUS 7 satellite measurements. Although comparisons with satellite measurements are limited to January through May, the model simulations are compared during other seasons. The model simulations and the satellite data are found to be consistent with the winter O3 loss analysis, It is shown that such analyses are likely to be inappropriate during other seasons. C1 NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RP PROFFITT, MH (reprint author), NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. NR 20 TC 35 Z9 35 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JAN 20 PY 1992 VL 97 IS D1 BP 939 EP 944 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HA087 UT WOS:A1992HA08700009 ER PT J AU PANIGOT, MJ WATERS, JF VARDE, U SUTTER, JK SUKENIK, CN AF PANIGOT, MJ WATERS, JF VARDE, U SUTTER, JK SUKENIK, CN TI BENZONORBORNADIENE END CAPS FOR PMR RESINS SO MACROMOLECULES LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; DI-ARYNE EQUIVALENTS; CAPPED POLYIMIDES; N-PHENYLNADIMIDE; POLYMERIZATION; PHOTOREARRANGEMENT; REGIOSELECTIVITY; SUBSTITUENTS; IPTYCENES; ARENES AB Several ortho-disubstituted benzonorbornadiene derivatives are described. These molecules contain acid, ester, or anhydride functionality permitting their use as end caps in PMR (polymerization of monomer reactants) polyimide systems. The replacement of the currently used norbornenyl end caps with benzonorbornadienyl end caps affords resins of increased aromatic content. It also allows evaluation of some mechanistic aspects of PMR cross-linking. Initial testing of N-phenylimide model compounds and of actual resin formulations using the benzonorbornadienyl end cap reveals that they undergo efficient thermal cross-linking to give oligomers with physical properties and thermal stability comparable to commercial norbornene-end-capped PMR systems. C1 CASE WESTERN RESERVE UNIV,DEPT CHEM,CLEVELAND,OH 44106. NASA,LEWIS RES CTR,POLYMER SCI BRANCH,CLEVELAND,OH 44135. NR 30 TC 8 Z9 9 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 20 PY 1992 VL 25 IS 2 BP 530 EP 534 DI 10.1021/ma00028a006 PG 5 WC Polymer Science SC Polymer Science GA HB418 UT WOS:A1992HB41800006 ER PT J AU CRAIG, H WHARTON, RA MCKAY, CP AF CRAIG, H WHARTON, RA MCKAY, CP TI OXYGEN SUPERSATURATION IN ICE-COVERED ANTARCTIC LAKES - BIOLOGICAL VERSUS PHYSICAL CONTRIBUTIONS SO SCIENCE LA English DT Article AB Freezing in ice-covered lakes causes dissolved gases to become supersaturated while at the same time removing gases trapped in the ablating ice cover. Analysis of N2, O2, and Ar in bubbles from Lake Hoare ice shows that, white O2 is approximately 2.4 times supersaturated in the water below the ice, only 11% of the O2 input to this lake is due to biological activity: 89% of the O2 is derived from meltwater inflow. Trapped bubbles in a subliming ice cover provide a natural "fluxmeter" for gas exchange: in Lake Hoare as much as 70% of the total gas loss may occur by advection through the ice cover, including approximately 75% of the N2, approximately 59% of the O2, and approximately 57% of the Ar losses. The remaining gas fractions are removed by respiration at the lower boundary (O2) and by molecular exchange with the atmosphere in the peripheral summer moat around the ice. C1 UNIV NEVADA SYST,DESERT RES INST,RENO,NV 89506. NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035. RP CRAIG, H (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,ISOTOPE LAB,LA JOLLA,CA 92093, USA. FU NCCDPHP CDC HHS [DP84-16340] NR 8 TC 55 Z9 55 U1 2 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 17 PY 1992 VL 255 IS 5042 BP 318 EP 321 DI 10.1126/science.11539819 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GZ695 UT WOS:A1992GZ69500038 PM 11539819 ER PT J AU DICKEY, JO MARCUS, SL STEPPE, JA HIDE, R AF DICKEY, JO MARCUS, SL STEPPE, JA HIDE, R TI THE EARTHS ANGULAR-MOMENTUM BUDGET ON SUBSEASONAL TIME SCALES SO SCIENCE LA English DT Article ID ROTATION; LENGTH AB Irregular length of day (LOD) fluctuations on time scales of less than a few years are largely produced by atmospheric torques on the underlying planet. Significant coherence is found between the respective time series of LOD and atmospheric angular momentum (AAM) determinations at periods down to 8 days, with lack of coherence at shorter periods caused by the declining signal-to-measurement noise ratios of both data types. Refinements to the currently accepted model of tidal Earth rotation variations are required, incorporating in particular the nonequilibrium effect of the oceans. The remaining discrepancies between LOD and AAM in the 100- to 10-day period range may be due to either a common error in the AAM data sets from different meteorological centers, or another component of the angular momentum budget. C1 UNIV OXFORD,CLARENDON LAB,ROBERT HOOKE INST,OXFORD,ENGLAND. RP DICKEY, JO (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. OI Marcus, Steven/0000-0002-5763-6961 NR 21 TC 46 Z9 48 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 17 PY 1992 VL 255 IS 5042 BP 321 EP 325 DI 10.1126/science.255.5042.321 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GZ695 UT WOS:A1992GZ69500039 PM 17779582 ER PT J AU DEAN, EJ GLOWINSKI, R KUO, YM NASSER, G AF DEAN, EJ GLOWINSKI, R KUO, YM NASSER, G TI MULTIPLIER TECHNIQUES FOR SOME DYNAMIC-SYSTEMS WITH DRY FRICTION SO COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE I-MATHEMATIQUE LA English DT Article AB In this Note, we discuss the numerical simulation of the behavior of dynamical systems with dry friction. The systems that we consider are from elasto-dynamics and are related to real life applications such as the real time simulation of remote manipulator systems when friction is taking place at the joints linking their various components. The numerical methods discussed here combine finite differenes for the time discretization and the systematic use of vector multipliers modelling the friction forces. We also discuss a regularization procedure which dramatically improves the convergence properties of the discrete friction multipliers to their continuous analogues. To conclude this Note, we present the results of numerical experiments which in our opinion fully validate the numerical methodology discussed here. C1 UNIV PARIS 06,F-75252 PARIS 05,FRANCE. DEPT MATH,HOUSTON,TX 77004. NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. LOCKHEED ENGN & SCI CO,HOUSTON,TX 77058. RP DEAN, EJ (reprint author), UNIV HOUSTON,DEPT MATH,HOUSTON,TX 77004, USA. NR 6 TC 4 Z9 4 U1 0 U2 0 PU GAUTHIER-VILLARS PI PARIS PA S P E S-JOURNAL DEPT, 120 BD ST GERMAIN, F-75006 PARIS, FRANCE SN 0764-4442 J9 CR ACAD SCI I-MATH JI Comptes Rendus Acad. Sci. Ser. I-Math. PD JAN 16 PY 1992 VL 314 IS 2 BP 153 EP 159 PG 7 WC Mathematics SC Mathematics GA HE108 UT WOS:A1992HE10800013 ER PT J AU AMINPOUR, MA AF AMINPOUR, MA TI AN ASSUMED-STRESS HYBRID 4-NODE SHELL ELEMENT WITH DRILLING DEGREES OF FREEDOM SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article ID FINITE-ELEMENTS AB An assumed-stress hybrid/mixed 4-node quadrilateral shell element is introduced that alleviates most of the deficiencies associated with such elements. The formulation of the element is based on the assumed-stress hybrid/mixed method using the Hellinger-Reissner variational principle. The membrane part of the element has 12 degrees of freedom including rotational or 'drilling' degrees of freedom at the nodes. The bending part of the element also has 12 degrees of freedom. The bending part of the element uses the Reissner-Mindlin plate theory which takes into account the transverse shear contributions. The element formulation is derived from an 8-node isoparametric element by expressing the midside displacement degrees of freedom in terms of displacement and rotational degrees of freedom at corner nodes. The element passes the patch test, is nearly insensitive to mesh distortion, does not 'lock', possesses the desirable invariance properties, has no hidden spurious modes, and for the majority of test cases used in this paper produces more accurate results than the other elements employed herein for comparison. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP AMINPOUR, MA (reprint author), ANALYT SERV & MAT INC,107 RES DR,HAMPTON,VA 23666, USA. NR 28 TC 31 Z9 32 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD JAN 15 PY 1992 VL 33 IS 1 BP 19 EP 38 DI 10.1002/nme.1620330103 PG 20 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA GX342 UT WOS:A1992GX34200002 ER PT J AU MURTHY, DV AF MURTHY, DV TI SOLUTION AND SENSITIVITY ANALYSIS OF A COMPLEX TRANSCENDENTAL EIGENPROBLEM WITH PAIRS OF REAL EIGENVALUES SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article ID DERIVATIVES AB This paper considers complex transcendental eigenvalue problems where one is interested in pairs of eigenvalues that are restricted to take real values only. Such eigenvalue problems arise in dynamic stability analysis of non-conservative physical systems-flutter analysis of aeroelastic systems, to name one example. Some available solution methods are discussed and a new method is presented. Two computational approaches are described for analytical evaluation of the sensitivities of these eigenvalues when they are dependent on other parameters. The algorithms presented are illustrated through examples. C1 NASA, LEWIS RES CTR, CLEVELAND, OH 44135 USA. RP UNIV TOLEDO, TOLEDO, OH 43606 USA. NR 22 TC 3 Z9 3 U1 1 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0029-5981 EI 1097-0207 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD JAN 15 PY 1992 VL 33 IS 1 BP 115 EP 129 DI 10.1002/nme.1620330108 PG 15 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA GX342 UT WOS:A1992GX34200007 ER PT J AU BAUSCHLICHER, CW LANGHOFF, SR PARTRIDGE, H AF BAUSCHLICHER, CW LANGHOFF, SR PARTRIDGE, H TI THEORETICAL-STUDY OF THE BELI, BENA, MGLI, MGNA, AND ALBE MOLECULES AND THEIR NEGATIVE-IONS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORE VALENCE CORRELATION; GAUSSIAN-BASIS SETS; GTO BASIS-SETS; ELECTRONIC-STRUCTURE; 2ND-ROW ATOMS; ABINITIO; CLUSTERS; ALKALI; ENERGY; AFFINITIES AB The alkaline earth-alkali diatomics are found to have weak bonds, because the diffuse alkali valence s orbitals cannot form a bond of sufficient strength to pay the promotion energy of the alkaline-earth atoms. This leads to van der Waals bonding in the neutrals as well as the negative ions. In fact, the negative ions have larger binding energies than the neutrals as a result of the much larger polarizability of the negative ion. The binding energy of AlBe is significantly larger than the Be-alkali molecules, due to a covalent contribution to the bonding. The binding energy in AlBe- is considerably larger than AlBe; the binding energy of the X (3)SIGMA- state of AlBe- is computed to be 1.36 eV, as compared with 0.57 eV for the X (2)PI state of AlBe. RP BAUSCHLICHER, CW (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 27 TC 38 Z9 38 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1992 VL 96 IS 2 BP 1240 EP 1247 DI 10.1063/1.462160 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GZ913 UT WOS:A1992GZ91300043 ER PT J AU STEGMANN, PM LEWIS, MR DAVIS, CO CULLEN, JJ AF STEGMANN, PM LEWIS, MR DAVIS, CO CULLEN, JJ TI PRIMARY PRODUCTION ESTIMATES FROM RECORDINGS OF SOLAR STIMULATED FLUORESCENCE IN THE EQUATORIAL PACIFIC AT 150-DEGREES-W SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NATURAL PHYTOPLANKTON POPULATIONS; QUANTUM EFFICIENCY; CHLOROPHYLL-A; PHOTOSYNTHESIS; OCEAN; YIELD; ABSORPTION; WATERS; SEA AB Biological, optical, and hydrographical data were collected on the WEC88 cruise along 150-degrees-W and during a 6-day time series station on the equator during February/March 1988. This area was characterized by a subsurface chlorophyll maximum (SCM), located at 50-70 m depth at the equator and descending down to 120-125 m at the north and south end of the transect. Highest primary production rates were near-surface and confined to the equatorial region and stations between 7-degrees and 11-degrees-N. To determine the relationship between solar-stimulated fluorescence (centered at 683 nm wavelength) and primary production, a production-fluorescence model based on phytoplankton physiology and marine optics is described. Results of model calculations predict that there is a linear relation between production and fluorescence. A comparison between morning and midday measurements of the production-fluorescence relation showed that there was some difference between the two, whereas evening measurements, on the other hand, were distinctly different from the morning/midday ones. This seems to suggest that diurnal variations contribute significantly to variability in the quantum yield of photochemical processes. The ratio of the quantum yield of photosynthesis to the quantum yield of fluorescence (PHI(c)/PHI(f)), the parameter which will determine how well production can be estimated from optical recordings, ranged between 0.24 and 0.44 molC Ein-1 (an Einstein equals a mole of photons) for all stations. The highest value for this ratio occurred at the equatorial stations, indicating that interstation (i.e., latitudinal) variability could have an effect on the production-fluorescence relation. Measured (with C-14 incubations) and predicted production compared quite well, although high measured production rates for near-surface samples were underestimated in most cases. Since both production and fluorescence were nonlinear at high irradiance intensities, we recommend in the future that a nonlinear component be incorporated into our model to take this effect into account and thus allow us to refine our estimates of nonlinear data. C1 DALHOUSIE UNIV,DEPT OCEANOG,HALIFAX B3H 4J1,NS,CANADA. CALTECH,JET PROP LAB,PASADENA,CA 91109. BIGELOW LAB OCEAN SCI,BOOTHBAY HARBOR,ME 04575. RI Cullen, John/B-6105-2008 OI Cullen, John/0000-0002-7740-0999 NR 41 TC 23 Z9 23 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JAN 15 PY 1992 VL 97 IS C1 BP 627 EP 638 DI 10.1029/91JC02014 PG 12 WC Oceanography SC Oceanography GA GZ123 UT WOS:A1992GZ12300003 ER PT J AU CULLEN, JJ LEWIS, MR DAVIS, CO BARBER, RT AF CULLEN, JJ LEWIS, MR DAVIS, CO BARBER, RT TI PHOTOSYNTHETIC CHARACTERISTICS AND ESTIMATED GROWTH-RATES INDICATE GRAZING IS THE PROXIMATE CONTROL OF PRIMARY PRODUCTION IN THE EQUATORIAL PACIFIC SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID MARINE-PHYTOPLANKTON; NATURAL ASSEMBLAGES; OLIGOTROPHIC OCEAN; OPTICAL-PROPERTIES; CHLOROPHYLL-A; LIGHT; IRRADIANCE; IRON; PHOTOINHIBITION; LIMITATION AB Macronutrients persist in the surface layer of the equatorial Pacific Ocean because the production of phytoplankton is limited; the nature of this limitation has yet to be resolved. Measurements of photosynthesis as a function of irradiance (P-I) provide information on the control of primary productivity, a question of great biogeochemical importance. Accordingly, P-I was measured in the equatorial Pacific along 150-degrees-W, during February-March 1988. Diel variability of P-I showed a pattern consistent with nocturnal vertical mixing in the upper 20 m followed by diurnal stratification, causing photoinhibition near the surface at midday. Otherwise, the distribution of photosynthetic parameters with depth and the stability of P-I during simulated in situ incubations over 2 days demonstrated that photoadaptation was nearly complete at the time of sampling: photoadaptation had not been effectively countered by upwelling or vertical mixing. Measurements of P-I and chlorophyll during manipulations of trace elements showed that simple precautions to minimize contamination were sufficient to obtain valid rate measurements and that the specific growth rates of phytoplankton were fairly high in situ, a minimum of 0.6 d-1. Diel variability of beam attenuation also indicated high specific growth rates of phytoplankton and a strong coupling of production with grazing. It appears that grazing is the proximate control on the standing crop of phytoplankton. Nonetheless, the supply of a trace nutrient such as iron might ultimately regulate productivity by influencing species composition and food-web structure. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. BIGELOW LAB OCEAN SCI,BOOTHBAY HARBOR,ME 04575. DUKE UNIV,MARINE LAB,BEAUFORT,NC 28516. RI Cullen, John/B-6105-2008 OI Cullen, John/0000-0002-7740-0999 NR 82 TC 159 Z9 161 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JAN 15 PY 1992 VL 97 IS C1 BP 639 EP 654 DI 10.1029/91JC01320 PG 16 WC Oceanography SC Oceanography GA GZ123 UT WOS:A1992GZ12300004 ER PT J AU BROCK, JC MCCLAIN, CR AF BROCK, JC MCCLAIN, CR TI INTERANNUAL VARIABILITY IN PHYTOPLANKTON BLOOMS OBSERVED IN THE NORTHWESTERN ARABIAN SEA DURING THE SOUTHWEST MONSOON SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WESTERN INDIAN-OCEAN; ZONE COLOR SCANNER; EASTERN EQUATORIAL PACIFIC; SURFACE THERMAL STRUCTURE; EURASIAN SNOW COVER; SUMMER MONSOON; PIGMENT CONCENTRATIONS; APPARENT RELATIONSHIP; ATLANTIC BIGHT; SOMALI CURRENT AB Interannual changes in the strength and seasonal evolution of the 1979 through 1982 surface level southwest monsoon winds have been related to variations in the summer phytoplankton bloom of the northwestern Arabian Sea by synthesis of satellite ocean color remote sensing with analysis of in situ hydrographic and meteorological data sets. The 1979-1981 southwest monsoon phytoplankton blooms in the northwest Arabian Sea peaked during August-September, extended from the Omani coast to about 65-degrees-E, and appeared to lag the development of open-sea upwelling by at least 1 month. In all 3 years the bloom was driven by spatially distinct upward nutrient fluxes to the euphotic zone forced by the physical processes of coastal upwelling and offshore Ekman pumping. Coastal upwelling was evident from May through September, yielded the most extreme concentrations of phytoplankton biomass, and along the Omani coast was limited in its impact on upper ocean biological variability to the continental shelf. Ekman pumping stimulated the development of a broad open-ocean component of the southwest monsoon phytoplankton bloom oceanward of the Omani shelf. Phytoplankton biomass on the Omani continental shelf was increased during both the early and late phases of the 1980 southwest monsoon due to stronger coastal upwelling under the most intense southwesterly winds of the four summers investigated. Diminished coastal upwelling during the early phase of the weak 1982 southwest monsoon resulted in a coastal bloom that reached a mean phytoplankton pigment concentration that was 28% of that seen in 1980. The lack of a strong regional northwestern Arabian Sea bloom in late summer 1982 is attributed to the development of persistent, shallow temperature stratification that rendered Ekman pumping less effective in driving upward nutrient fluxes. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NASA,GODDARD SPACE FLIGHT CTR,OCEANS & ICE BRANCH,GREENBELT,MD 20771. NR 92 TC 120 Z9 123 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JAN 15 PY 1992 VL 97 IS C1 BP 733 EP 750 DI 10.1029/91JC02225 PG 18 WC Oceanography SC Oceanography GA GZ123 UT WOS:A1992GZ12300012 ER PT J AU ANDRAS, MT DURAJ, SA HEPP, AF FANWICK, PE BODNAR, MM AF ANDRAS, MT DURAJ, SA HEPP, AF FANWICK, PE BODNAR, MM TI SYNTHESIS AND CHARACTERIZATION OF THE 1ST MAIN GROUP OXO-CENTERED TRINUCLEAR CARBOXYLATE SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID VIBRATIONAL-SPECTRA; METAL-COMPLEXES; COBALT(III) C1 CLEVELAND STATE UNIV, DEPT CHEM, CLEVELAND, OH 44115 USA. NASA, LEWIS RES CTR, PHOTOVOLTAIC BRANCH, CLEVELAND, OH 44135 USA. PURDUE UNIV, DEPT CHEM, W LAFAYETTE, IN 47907 USA. NR 15 TC 22 Z9 22 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 15 PY 1992 VL 114 IS 2 BP 786 EP 787 DI 10.1021/ja00028a070 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA GZ441 UT WOS:A1992GZ44100070 ER PT J AU ELIZALDE, E GAZTANAGA, E AF ELIZALDE, E GAZTANAGA, E TI VOID PROBABILITY AS A FUNCTION OF THE VOIDS SHAPE AND SCALE-INVARIANT MODELS SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article ID POINT CORRELATION-FUNCTIONS; GALAXY DISTRIBUTION; STATISTICAL-ANALYSIS; MATTER DISTRIBUTION; REDSHIFT SURVEY; UNIVERSE; HIERARCHY; CATALOGS; CLUSTERS; 2-POINT AB Counts in cells, the probabilities P(i) to have i galaxies inside a randomly chosen cell of volume V, and in particular the void probability P0, are related to higher order correlation functions and have received increasing attention as a tool to study 3D redshift catalogues, and to compare them with simulations or theoretical predictions. The dependence of counts in cells on the shape of the cell is studied here. A very concrete prediction is made concerning the void distribution for scale-invariant models, namely that the shape dependence can be obtained from the volume dependence by an appropriate scaling. This prediction is tested on a sample of the CfA catalogue, and good agreement is found. It is observed that the probability of voids is bigger for spherical cells than for elongated ones, whereas the probability of a cell to be occupied has a maximum for some elongated cells. A phenomenological scale-invariant model for the observed distribution of the counts in cells - an extension of the negative binomial distribution - is exhibited in order to illustrate how this dependence can be quantitatively determined. An original, intuitive derivation of the model is presented. C1 FERMI NATL ACCELERATOR LAB,NASA,CTR ASTROPHYS,BATAVIA,IL 60510. RP ELIZALDE, E (reprint author), UNIV BARCELONA,FAC PHYS,DEPT ECM,DIAGONAL 647,E-08028 BARCELONA,SPAIN. NR 42 TC 16 Z9 16 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN 15 PY 1992 VL 254 IS 2 BP 247 EP 256 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GZ103 UT WOS:A1992GZ10300006 ER PT J AU GUPTA, AK HILL, CT HOLMAN, R KOLB, EW AF GUPTA, AK HILL, CT HOLMAN, R KOLB, EW TI STATISTICAL-MECHANICS OF SOFT-BOSON PHASE-TRANSITIONS SO PHYSICAL REVIEW D LA English DT Article ID PSEUDO-GOLDSTONE BOSONS; LARGE-SCALE STRUCTURE; BROKEN LEPTON NUMBER; INFLATIONARY UNIVERSE; DOMAIN-WALLS; DENSITY PERTURBATIONS; SYMMETRY-BREAKING; DARK MATTER; GENERATION; EVOLUTION AB The existence of structures on large (say, 100 Mpc) scales and limits to anisotropies in the cosmic microwave background radiation (CMBR) have imperiled models of structure formation based solely upon the standard cold-dark-matter scenario. Novel scenarios, which may be compatible with large-scale structure and small CMBR anisotropies, invoke nonlinear fluctuations in the density appearing after recombination, accomplished via the use of late-time phase transitions involving ultralow-mass scalar bosons. Here, we study the statistical mechanics of such phase transitions in several models involving naturally ultralow-mass pseudo Nambu-Goldstone bosons (PNGB's). These models can exhibit several interesting effects at high temperature, which we argue are the most general possibilities for PNGB's. C1 FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP GUPTA, AK (reprint author), CARNEGIE MELLON UNIV,DEPT PHYS,PITTSBURGH,PA 15213, USA. NR 50 TC 30 Z9 30 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JAN 15 PY 1992 VL 45 IS 2 BP 441 EP 454 DI 10.1103/PhysRevD.45.441 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA HB215 UT WOS:A1992HB21500008 ER PT J AU SARKAR, B LISAGOR, WB AF SARKAR, B LISAGOR, WB TI FRACTURE-RESISTANCE AND FATIGUE CRACK-GROWTH CHARACTERISTICS OF 2 AL-CU-MG-ZR ALLOYS SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP SARKAR, B (reprint author), LOCKHEED ENGN & SCI,HAMPTON,VA, USA. NR 12 TC 1 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD JAN 15 PY 1992 VL 26 IS 2 BP 169 EP 174 DI 10.1016/0956-716X(92)90167-D PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA GZ158 UT WOS:A1992GZ15800002 ER PT J AU LOEWENSTEIN, M AF LOEWENSTEIN, M TI DARK MATTER IN NGC-4472 SO ASTROPHYSICAL JOURNAL LA English DT Article DE DARK MATTER; GALAXIES, INDIVIDUAL (NGC-4472); GALAXIES, STRUCTURE; X-RAYS, GALAXIES ID EARLY-TYPE GALAXIES; ELLIPTICAL GALAXIES; GLOBULAR-CLUSTERS; SPIRAL GALAXIES; MASS; KINEMATICS; SPECTROSCOPY; PHOTOMETRY; EVOLUTION; FLOWS AB I attempt to constrain the total mass distribution of the well-observed giant elliptical galaxy NGC 4472 by constructing simultaneous equilibrium models for the gas and stars using all available relevant optical and X-ray data. The value of , the emission-weighted average value of kT, derived from the Ginga spectrum- = 1.9 +/- 0.2 keV (Awaki et al.)-can be reproduced only in hydrostatic models where nonluminous matter comprises at least 90% of the total mass. However, in general, these mass models are not consistent with observed projected stellar and globular cluster velocity dispersions at moderate radii (0'.5-4'.0). Mass models with hydrostatic gas distributions that have = 1.5 keV are marginally consistent with the stellar velocity dispersion data; and I discuss how contributions to the X-ray spectrum from additional high-temperature components such as supernova bubbles, X-ray binaries, and encroaching intracluster gas may cause simple one-component analysis of X-ray spectra to systematically overestimate the true hydrostatic gas temperature. These effects, however, cannot be important enough to reduce the required amount of dark matter below 70% of the total mass; models without dark matter have < 0.8 keV. If the true value of is 1.5 keV or greater, the range of dark matter distributions consistent with both X-ray and optical spectra is very small, essentially consisting of a line in the halo scale length-total mass plane, and the inferred minimum mass-to-light ratio is 40h50 in solar units where h50 is the Hubble constant in units of 50 km s-1 Mpc-1. C1 UNIV SPACE RES ASSOC,WASHINGTON,DC. RP LOEWENSTEIN, M (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,CODE 666,GREENBELT,MD 20771, USA. NR 28 TC 11 Z9 11 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 10 PY 1992 VL 384 IS 2 BP 474 EP 481 DI 10.1086/170889 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GY758 UT WOS:A1992GY75800009 ER PT J AU BRAINERD, JJ AF BRAINERD, JJ TI MULTIPLE RESONANT SCATTERING IN THE COMPTON UPSCATTER MODEL OF GAMMA-RAY BURSTS SO ASTROPHYSICAL JOURNAL LA English DT Article DE GAMMA-RAYS, BURSTS; RADIATION MECHANISMS, COMPTON AND INVERSE COMPTON; RADIATIVE TRANSFER; STARS, MAGNETIC; STARS, NEUTRON ID STRONG MAGNETIC-FIELDS; SPECTRA; ELECTRONS; EMISSION; RADIATION; PHOTON; LINES AB Resonant Compton scattering, an increasingly popular mechanism for suppressing X-rays and producing gamma rays, must be treated as a multiple-scattering process for conditions thought characteristic of gamma-ray bursts. Photons that multiply scatter with a beamed power-law electron distribution in a uniform magnetic field produce a flat spectrum between the cyclotron frequency and an optical-depth-dependent critical energy; this critical energy ranges between several hundred keV and several MeV. Above this critical energy, the gamma-ray spectrum has a shape determined by the electron distribution and described by a single-scattering model. Only electron distributions that are nearly proportional to the electron momentum are able to simultaneously suppress X-rays and produce a single-scattering spectrum. As the Thomson optical depth approaches unity, photons that experience multiple scatterings often spawn additional photons at a rate that makes the model unphysical. RP BRAINERD, JJ (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,ES-65,HUNTSVILLE,AL 35812, USA. NR 26 TC 3 Z9 3 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 10 PY 1992 VL 384 IS 2 BP 545 EP 559 DI 10.1086/170897 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GY758 UT WOS:A1992GY75800017 ER PT J AU PAN, XP SHAO, M COLAVITA, MM ARMSTRONG, JT MOZURKEWICH, D VIVEKANAND, M DENISON, CS SIMON, RS JOHNSTON, KJ AF PAN, XP SHAO, M COLAVITA, MM ARMSTRONG, JT MOZURKEWICH, D VIVEKANAND, M DENISON, CS SIMON, RS JOHNSTON, KJ TI DETERMINATION OF THE VISUAL ORBIT OF THE SPECTROSCOPIC BINARY ALPHA ANDROMEDAE WITH SUBMILLIARCSECOND PRECISION SO ASTROPHYSICAL JOURNAL LA English DT Article DE BINARIES, VISUAL; INSTRUMENTATION, INTERFEROMETERS; STARS, INDIVIDUAL (ALPHA-ANDROMEDAE) ID III STELLAR INTERFEROMETER; OPTICAL ASTROMETRY; AP STARS AB The visual orbit of the spectroscopic binary alpha-And has been determined independently of spectroscopic data using the Mark III Stellar Interferometer. Observations of alpha-And in 1988 and 1989 clearly demonstrate submilliarcsecond measurement precision at optical wavelengths. All of the orbital elements of alpha-And have been calculated utilizing observations from the Mark III Stellar Interferometer only and are in excellent agreement with the spectroscopic results. However, three of these elements, i.e., a'', i, and OMEGA, can only be obtained from interferometric data. Using both interferometric and spectroscopic observations, the definitive orbital elements are determined as follows: angular semimajor axis a'' = 0.02415'' +/- 0.00013'', inclination i = 105.66-degrees +/- 0.22-degrees, position angle of ascending node OMEGA = 104.16-degrees +/- 0.25-degrees, longitude of periastron-omega = 77.31-degrees +/-0.32-degrees, period P = 96.6960d +/- 0.0013d, eccentricity e = 0.527 +/- 0.004, and epoch of periastron passage T = JD 2,447,374.77 +/- 0.15. In addition, the magnitude difference between the two components has been measured, yielding DELTA-m = 1.82 +/- 0.04 mag at 800 nm and DELTA-m = 1.99 +/- 0.04 mag at 550 nm. Incorporating photometric observations, the color indices between 550 nm and 800 nm for the primary and the companion are determined as -0.11 +/- 0.03 mag and +0.07 +/- 0.05 mag, respectively. C1 CALTECH,JET PROP LAB,OPT SCI & APPLICAT SECT,PASADENA,CA 91109. USN OBSERV,NAVAL RES LAB,OPT INTERFEROMETER PROJECT,WASHINGTON,DC 20392. RP PAN, XP (reprint author), CALTECH,DEPT ASTRON,PASADENA,CA 91125, USA. NR 38 TC 31 Z9 32 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 10 PY 1992 VL 384 IS 2 BP 624 EP 633 DI 10.1086/170904 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GY758 UT WOS:A1992GY75800024 ER PT J AU LEDLOW, MJ BURNS, JO GISLER, GR ZHAO, JH ZEILIK, M BAKER, DN AF LEDLOW, MJ BURNS, JO GISLER, GR ZHAO, JH ZEILIK, M BAKER, DN TI SUBSURFACE EMISSIONS FROM MERCURY - VLA RADIO OBSERVATIONS AT 2 AND 6 CENTIMETERS SO ASTROPHYSICAL JOURNAL LA English DT Article DE PLANETS AND SATELLITES, INDIVIDUAL (MERCURY); RADIO CONTINUUM, SOLAR SYSTEM ID TEMPERATURES; WAVELENGTHS; SURFACE AB We present radio observations of Mercury made with the VLA; once in 1986, and on two dates in February of 1988. These observations are the first to spatially map both hot regions associated with the theoretical "hot poles." These "hot poles" are separated by 180-degrees and are a result of the unusual diurnal heating from Mercury's 3/2 spin-orbit resonance and eccentric orbit. Our highest resolution data maps areas of the planet as small as 330 km. We include maps of total intensity, brightness temperature, polarized intensity, fractional polarization, depolarization, and spectral index. We find that the subsurface thermal emissions from Mercury are characteristic of blackbody reradiation from the solar insolation over a diurnal cycle. We use these observations to produce full-disk thermophysical models. We have solved the one-dimensional, time-dependent heat-diffusion equation for all observed disk elements at each epoch in order to constrain thermophysical parameters and properties of the subsurface material. Using typical lunar values for several of the parameters, we are able to reproduce the temperature morphology and most of the observed temperature values. We do, however, find that the best-fit models require a substantial contribution of the heat transport in the subsurface to be radiative in nature. The primary difficulty in our models is in predicting the observed temperature differences as a function of frequency. C1 NEW MEXICO STATE UNIV,DEPT ASTRON,LAS CRUCES,NM 88003. UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP LEDLOW, MJ (reprint author), UNIV NEW MEXICO,DEPT PHYS & ASTRON,ALBUQUERQUE,NM 87131, USA. NR 37 TC 21 Z9 21 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 10 PY 1992 VL 384 IS 2 BP 640 EP 655 DI 10.1086/170906 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GY758 UT WOS:A1992GY75800026 ER PT J AU MIELKE, SL FRIEDMAN, RS TRUHLAR, DG SCHWENKE, DW AF MIELKE, SL FRIEDMAN, RS TRUHLAR, DG SCHWENKE, DW TI HIGH-ENERGY STATE-TO-STATE QUANTUM DYNAMICS FOR D+H2(UPSILON = J = 1)-]HD(UPSILON' = 1, J') + H SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; ROTATIONAL-EXCITATION; MOLECULAR-COLLISIONS; VARIATIONAL-METHODS; D+H2->HD+H AB The state-to-state cross sections for D + H-2 (upsilon = j = 1) --> HD(upsilon' --> 1, j' = 0-13) + H at total energy 1.8164 eV have been calculated by accurate quantum dynamics, using larger basis sets and more stringent convergence criteria than in previous work. The cross sections differ from previous calculations by up to 10%, but they still differ from recent experiments by Kliner, Adelman and Zare by significantly more than the experimental error bars. C1 UNIV MINNESOTA, INST SUPERCOMP, MINNEAPOLIS, MN 55455 USA. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RP MIELKE, SL (reprint author), UNIV MINNESOTA, DEPT CHEM, PROGRAM CHEM PHYS, MINNEAPOLIS, MN 55455 USA. RI Mielke, Steven/B-7533-2008; schwenke, david/I-3564-2013; Truhlar, Donald/G-7076-2015 OI Mielke, Steven/0000-0002-1938-7503; Truhlar, Donald/0000-0002-7742-7294 NR 21 TC 42 Z9 42 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JAN 10 PY 1992 VL 188 IS 3-4 BP 359 EP 367 DI 10.1016/0009-2614(92)90037-N PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HB670 UT WOS:A1992HB67000037 ER PT J AU CARSEY, F AF CARSEY, F TI REMOTE-SENSING OF ICE AND SNOW - REVIEW AND STATUS SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article; Proceedings Paper CT 5TH SCIENTIFIC ASSEMBLY OF THE INTERNATIONAL ASSOC OF METEOROLOGY AND ATMOSPHERIC PHYSICS CY AUG 08, 1989 CL UNIV READING, READING, ENGLAND SP INT ASSOC METEOROL & ATMOSPHER PHYS HO UNIV READING ID SEA-ICE; ALASKA; NORTH; AREA AB The status of obtaining geophysically useful observations of ice and snow through the interpretation of satellite data is discussed. Over the last decade, the examination of satellite data for information on ice and snow has developed rapidly; datasets of results have been generated; the connections between ice and snow microscopic properties and their electromagnetic behaviour are now better understood; and a good deal of accurate satellite-derived information on ice and snow can now be obtained. RP CARSEY, F (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 30 TC 10 Z9 10 U1 7 U2 10 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD JAN 10 PY 1992 VL 13 IS 1 BP 5 EP 11 PG 7 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA GZ503 UT WOS:A1992GZ50300002 ER PT J AU TAO, W KLEMM, RB NESBITT, FL STIEF, LJ AF TAO, W KLEMM, RB NESBITT, FL STIEF, LJ TI A DISCHARGE FLOW-PHOTOIONIZATION MASS-SPECTROMETRIC STUDY OF HYDROXYMETHYL RADICALS (H2COH AND H2COD) - PHOTOIONIZATION SPECTRUM AND IONIZATION-ENERGY SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ABSOLUTE RATE-CONSTANT; GAS-PHASE; PHOTOELECTRON-SPECTROSCOPY; IONS; CH3O; DISSOCIATION; CATIONS; CH2OH; TEMPERATURE; HEATS AB The photoionization spectrum of H2COH was measured over the wavelength range 140-170 nm by using a discharge flow-photoionization mass spectrometer apparatus with synchrotron radiation. Hydroxymethyl radicals (H2COH and H2COD) were generated in a flow tube by the reaction of F atoms with CH3OH(D). Ionization energies (IE) were determined directly from photoion thresholds. The IE values, 7.56 +/- 0.02 and 7.55 +/- 0.02 eV for H2COH and H2COD, respectively, are consistent with previous measurements. Also, the dissociative ionization process, presumed to be H3CO* --> HCO+ + H-2, was observed with a threshold at 8.61 +/- 0.06 eV. C1 BROOKHAVEN NATL LAB,BLDG 815,UPTON,NY 11973. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,EXTRATERR PHYS LAB,HUNTSVILLE,AL 35812. NR 49 TC 42 Z9 44 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JAN 9 PY 1992 VL 96 IS 1 BP 104 EP 107 DI 10.1021/j100180a023 PG 4 WC Chemistry, Physical SC Chemistry GA GZ697 UT WOS:A1992GZ69700023 ER PT J AU MEEGAN, CA FISHMAN, GJ WILSON, RB PACIESAS, WS PENDLETON, GN HORACK, JM BROCK, MN KOUVELIOTOU, C AF MEEGAN, CA FISHMAN, GJ WILSON, RB PACIESAS, WS PENDLETON, GN HORACK, JM BROCK, MN KOUVELIOTOU, C TI SPATIAL-DISTRIBUTION OF GAMMA-RAY BURSTS OBSERVED BY BATSE SO NATURE LA English DT Article AB The nature of the sources of cosmic-gamma-ray bursts is a long-standing problem in astrophysics. Lack of knowledge of their true spatial distribution and of their intrinsic brightness has hampered theoretical understanding, of these enigmatic events. The Burst and Transient Source Experiment in the Compton-Gamma-Ray Observatory has been detecting bursts at the rate of about one a day, and we report here an analysis of 153 events. The number versus intensity distribution does not follow the -3/2 power law expected for a spatially extended homogeneous distribution of sources, but at the same time the angular distribution is isotropic within statistical limits. Taken together, these results are inconsistent with the spatial distribution of any known population of galactic objects, but may be consistent with the bursts being at cosmological distances. C1 UNIV ALABAMA,DEPT PHYS,HUNTSVILLE,AL 35899. UNIV SPACE RES ASSOC,COLUMBIA,MD. RP MEEGAN, CA (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812, USA. RI Horack, John/J-6670-2016 NR 18 TC 570 Z9 578 U1 1 U2 9 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 9 PY 1992 VL 355 IS 6356 BP 143 EP 145 DI 10.1038/355143a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GY629 UT WOS:A1992GY62900050 ER PT J AU LEE, TJ AF LEE, TJ TI BOND DISTANCE AND VIBRATIONAL-SPECTRUM OF THE MOLECULAR CATION NO2+ SO CHEMICAL PHYSICS LETTERS LA English DT Article AB The equilibrium bond distance, vibrational frequencies, infrared intensities, and potential energy force constants (through quartic force constants) have been determined for the molecular cation NO2+. Very large atomic natural orbital (ANO) one-particle basis sets have been used in conjunction with the singles and doubles coupled-cluster (CCSD) and CCSD(T) electron correlation methods in this study. The ANO basis sets include up through g-type functions. At the highest level of theory the equilibrium N-O bond distance is computed to be 1.122 angstrom, and the uncertainty in this value is conservatively estimated to be +/- 0.003 angstrom. The fundamental vibrational frequencies are predicted to occur at 1384, 625 and 2344 cm-1 for nu-1 (sigma(g)), nu-2(pi(u)) and nu-3 (sigma(u)), respectively. RP LEE, TJ (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RI Lee, Timothy/K-2838-2012 NR 17 TC 25 Z9 25 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JAN 3 PY 1992 VL 188 IS 1-2 BP 154 EP 158 DI 10.1016/0009-2614(92)85106-K PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA HA584 UT WOS:A1992HA58400029 ER PT J AU WEBSTER, CR MAY, RD AF WEBSTER, CR MAY, RD TI INSITU STRATOSPHERIC MEASUREMENTS OF CH4, (CH4)-C-13, N2O, AND (OCO)-O-18 USING THE BLISS TUNABLE DIODE-LASER SPECTROMETER SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC METHANE; DIURNAL-VARIATIONS; O-3; HNO3; H2O; NO2 AB Simultaneous in situ measurements of stratospheric CH4, (CH4)-C-13 N2O, (OCO)-O-18, pressure, and temperature have been made from Palestine, Texas (32-degrees-N) in September 1998 with the JPL Balloon-borne Laser In Situ Sensor (BLISS). Measurements of CH4 and N2O in the altitude range 30-35 km agree well with other measurements, except for an anomalously high value for the N2O at 31 km. Measurements of CH4 support earlier observations of a fold in the vertical profile. A ratio for stratospheric (CH4)-C-13/CH4 of 0.0105 +/- 0.0010 implies an enrichment of delta-C-13 = -45 +/- 92 parts per thousand over the PDB value, in agreement with previous measurements in the troposphere. A large mixing ratio of 1.9 +/- 0.2 ppmv for (OCO)-O-18 is measured, corresponding to an enrichment of delta-O-18 = 280 +/- 50 parts per thousand for the O-18 isotopic species over the SMOW-value. RP WEBSTER, CR (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 34 TC 15 Z9 15 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 3 PY 1992 VL 19 IS 1 BP 45 EP 48 DI 10.1029/91GL02782 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GZ810 UT WOS:A1992GZ81000012 ER PT J AU TSURUTANI, BT GONZALEZ, WD TANG, F LEE, YT AF TSURUTANI, BT GONZALEZ, WD TANG, F LEE, YT TI GREAT MAGNETIC STORMS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GEOMAGNETIC STORMS; SOLAR-CYCLE; WAVES; CLOUDS; WIND AB The five largest magnetic storms that occurred between 1971 to 1986 are studied to determine their solar and interplanetary causes. All of the events are found to be associated with high speed solar wind streams led by collisionless shocks. The high speed streams are clearly related to identifiable solar flares. It is found that: 1) it is the extreme values of the southward interplanetary magnetic fields rather than solar wind speeds that are the primary causes of great magnetic storms, 2) shocked and draped sheath fields preceding the driver gas (magnetic cloud) are at least as effective in causing the onset of great magnetic storms (3 of 5 events) as the strong fields within the driver gas itself, and 3) precursor southward fields ahead of the high speed streams allow the shock compression mechanism (item 2) to be particularly geoeffective. C1 INST NACL PESQUISAS ESPACIAIS,SAO JOSE CAMPOS,SP,BRAZIL. CALTECH,PASADENA,CA 91125. RP TSURUTANI, BT (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 20 TC 184 Z9 187 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 3 PY 1992 VL 19 IS 1 BP 73 EP 76 DI 10.1029/91GL02783 PG 4 WC Geosciences, Multidisciplinary SC Geology GA GZ810 UT WOS:A1992GZ81000019 ER PT J AU SIMONS, RN LEE, RQ AF SIMONS, RN LEE, RQ TI COPLANAR WAVE-GUIDE APERTURE COUPLED PATCH ANTENNAS WITH GROUND PLANE SUBSTRATE OF FINITE EXTENT SO ELECTRONICS LETTERS LA English DT Article DE ANTENNAS; MICROSTRIP; APERTURE COUPLED ANTENNAS AB Coplanar waveguide (CPW)/aperture coupled microstrip patch antennas constructed with ground coplanar waveguide (GCPW), finite coplanar waveguide (FCPW) and channelised coplanar waveguide (CCPW) are demonstrated. The measured characteristics show that the CCPW/aperture coupled microstrip patch antenna has the largest bandwidth, whereas the GCPW/aperture coupled microstrip patch antenna has the best front-to-back ratio. RP SIMONS, RN (reprint author), NASA,LEWIS RES CTR,MAIL STOP 54-5,21000 BROOKPARK RD,CLEVELAND,OH 44135, USA. NR 4 TC 11 Z9 11 U1 1 U2 2 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JAN 2 PY 1992 VL 28 IS 1 BP 75 EP 76 DI 10.1049/el:19920046 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA HA184 UT WOS:A1992HA18400046 ER PT J AU MCGLYNN, TA AF MCGLYNN, TA TI METEORITES - STARDUST AND PLANET DUST SO NATURE LA English DT Editorial Material ID OORT CLOUD; SEARCH; MASS RP MCGLYNN, TA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,COMP SCI CORP,GREENBELT,MD 20771, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 2 PY 1992 VL 355 IS 6355 BP 20 EP 21 DI 10.1038/355020a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA GY228 UT WOS:A1992GY22800024 ER PT J AU YOST, WT CANTRELL, JH AF YOST, WT CANTRELL, JH BE Liizi, PZ TI CONSTANT FREQUENCY ACOUSTIC PULSE PHASE-LOCKED LOOP METHOD FOR MEASURING MATERIAL NONLINEARITY SO 14TH INTERNATIONAL CONGRESS ON ACOUSTICS, PROCEEDINGS, VOLS 1-4 LA English DT Proceedings Paper CT 14th International Congress on Acoustics (ICA 14) CY SEP 03-10, 1992 CL BEIJING, PEOPLES R CHINA SP INT UNION PURE & APPL PHYS, ACOUST SOC CHINA, ACADEMIA SINICA, INST ACOUST C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIA SINICA INST ACOUSTICS PI BEIJING 100080 PA PROFESSOR WU WEI-FANG, BEIJING 100080, PEOPLES R CHINA PY 1992 BP 63 EP 64 PG 2 WC Acoustics; Architecture; Language & Linguistics; Mechanics; Music SC Acoustics; Architecture; Linguistics; Mechanics; Music GA BC62T UT WOS:A1992BC62T00011 ER PT J AU WENZEL, EM AF WENZEL, EM BE Liizi, PZ TI VIRTUAL ACOUSTIC DISPLAYS - LOCALIZATION IN SYNTHETIC ACOUSTIC ENVIRONMENTS SO 14TH INTERNATIONAL CONGRESS ON ACOUSTICS, PROCEEDINGS, VOLS 1-4 LA English DT Proceedings Paper CT 14th International Congress on Acoustics (ICA 14) CY SEP 03-10, 1992 CL BEIJING, PEOPLES R CHINA SP INT UNION PURE & APPL PHYS, ACOUST SOC CHINA, ACADEMIA SINICA, INST ACOUST C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIA SINICA INST ACOUSTICS PI BEIJING 100080 PA PROFESSOR WU WEI-FANG, BEIJING 100080, PEOPLES R CHINA PY 1992 BP 1491 EP 1492 PG 2 WC Acoustics; Architecture; Language & Linguistics; Mechanics; Music SC Acoustics; Architecture; Linguistics; Mechanics; Music GA BC62T UT WOS:A1992BC62T00725 ER PT J AU GOLDSTEIN, ME AF GOLDSTEIN, ME BE Liizi, PZ TI NOISE FROM TURBULENT SHEAR FLOWS SO 14TH INTERNATIONAL CONGRESS ON ACOUSTICS, PROCEEDINGS, VOLS 1-4 LA English DT Proceedings Paper CT 14th International Congress on Acoustics (ICA 14) CY SEP 03-10, 1992 CL BEIJING, PEOPLES R CHINA SP INT UNION PURE & APPL PHYS, ACOUST SOC CHINA, ACADEMIA SINICA, INST ACOUST C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIA SINICA INST ACOUSTICS PI BEIJING 100080 PA PROFESSOR WU WEI-FANG, BEIJING 100080, PEOPLES R CHINA PY 1992 BP 1711 EP 1716 PG 6 WC Acoustics; Architecture; Language & Linguistics; Mechanics; Music SC Acoustics; Architecture; Linguistics; Mechanics; Music GA BC62T UT WOS:A1992BC62T00824 ER PT J AU POLANSKY, M WITCHEY, D AF POLANSKY, M WITCHEY, D GP SOC EXPTL TEST PILOTS TI THE GBU-28 - CONCEPT TO COMBAT SO 1992 REPORT TO THE AEROSPACE PROFESSION, SETP 36TH SYMPOSIUM SE SYMPOSIUM PROCEEDINGS - SOCIETY OF EXPERIMENTAL TEST PILOTS LA English DT Proceedings Paper CT 36th Symposium of the Society-of-Experimental-Test-Pilots CY SEP, 1992 CL BEVERLY HILLS, CA SP SOC EXPTL TEST PILOTS C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL TEST PILOTS PI LANCASTER PA PO BOX 986, LANCASTER, CA 93534 SN 0742-3705 J9 SYMP P SOC EXP T PIL PY 1992 BP 122 EP 138 PG 17 WC Engineering, Aerospace SC Engineering GA BA57A UT WOS:A1992BA57A00008 ER PT J AU BONTING, SL AF BONTING, SL TI NEEDS FOR BIOSENSORS IN SPACE-BIOLOGY RESEARCH SO ACS SYMPOSIUM SERIES LA English DT Review AB Considerable advantages are expected from the use of biosensors in space biology research. They provide (near) real time monitoring of many important bioanalytes. Ideally, it is possible even to achieve continuous monitoring. Their use can save a considerable amount of crew time, which is always in short supply. The sensor output can without much difficulty be made available to the ground by telemetry. Desirable types of bioanalytical sensors for space biology research and monitoring of the quality of recycled water during long-term missions are discussed. RP BONTING, SL (reprint author), NASA,AMES RES CTR,SETI INST,MOFFETT FIELD,CA 94035, USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0097-6156 J9 ACS SYM SER PY 1992 VL 511 BP 174 EP 183 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA KG218 UT WOS:A1992KG21800014 ER PT J AU KAYE, JA AF KAYE, JA TI ISOTOPE EFFECTS IN GAS-PHASE CHEMICAL-REACTIONS AND PHOTODISSOCIATION PROCESSES - OVERVIEW SO ACS SYMPOSIUM SERIES LA English DT Editorial Material ID TEMPERATURE-DEPENDENCE; REACTION-KINETICS; RATE CONSTANTS; OH; CARBON; FRACTIONATION; DISSOCIATION; EXCHANGE; SPECTRA; OXYGEN AB The origins of isotope effects in equilibrium and non-equilibrium chemical processes are reviewed. In non-equilibrium processes, attention is given to isotope effects in simple bimolecular reactions, termolecular and complex forming bimolecular reactions, symmetry-related reactions, and photodissociation processes. Recent examples of isotope effects in these areas are reviewed. Some indication of other scientific areas for which measurements and/or calculations of isotope effects are used is also given. Examples presented focus on neutral molecule chemistry and in many cases complement examples considered in greater detail in the other chapters of this volume. RP KAYE, JA (reprint author), NASA HEADQUARTERS, DIV EARTH SCI & APPLICAT, WASHINGTON, DC 20546 USA. NR 52 TC 0 Z9 0 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0097-6156 J9 ACS SYM SER JI ACS Symp. Ser. PY 1992 VL 502 BP 1 EP 14 PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA JY550 UT WOS:A1992JY55000001 ER PT J AU MIYOSHI, K AF MIYOSHI, K TI TRIBOLOGICAL EVALUATION AND ANALYSIS OF COATING MATERIALS SO ACS SYMPOSIUM SERIES LA English DT Review ID HYDROGENATED CARBON-FILMS; SILICON-NITRIDE FILMS; AMORPHOUS-CARBON; ION-BEAM; DIAMONDLIKE CARBON; PLASMA DEPOSITION; BUTANE PLASMA; THIN-FILMS; WEAR; FRICTION C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 25 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0097-6156 J9 ACS SYM SER PY 1992 VL 485 BP 58 EP 71 PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA HT789 UT WOS:A1992HT78900005 ER PT J AU POST, WM CHAVEZ, F MULHOLLAND, PJ PASTOR, J PENG, TH PRENTICE, K WEBB, T AF POST, WM CHAVEZ, F MULHOLLAND, PJ PASTOR, J PENG, TH PRENTICE, K WEBB, T TI CLIMATIC FEEDBACKS IN THE GLOBAL CARBON-CYCLE SO ACS SYMPOSIUM SERIES LA English DT Review ID ATMOSPHERIC CO2 VARIATIONS; OXYGEN UTILIZATION RATES; SUB-TROPICAL GYRE; PAST 2 CENTURIES; NORTH-ATLANTIC; DEEP-OCEAN; OLIGOTROPHIC SYSTEMS; EQUATORIAL PACIFIC; DIOXIDE LEVELS; NITROGEN AB Increasing atmospheric CO2 is likely to produce chronic changes in global climate, as it may have done in the geologic past. Future CO2-induced changes in temperature and precipitation distribution changes could equal or exceed the changes which have occurred over the past 160,000 years and have affected the global carbon cycle. We consider ocean and terrestrial processes that could involve large changes in carbon fluxes (> 2 Pg C.yr-1) or changes in storage in large carbon pools (> 200 Pg C) resulting from CO2-induced climate changes. These include (1) air-sea exchange of CO2 in response to changes in temperature and salinity; (2) climate-induced changes in ocean circulation; (3) changes in oceanic new production and regeneration of organic debris caused directly by climate change; (4) altered oceanic nutrient supply needed to support new production due to climate-induced alteration of ocean circulation and river discharge; (5) CaCO3 compensation in sea water; (6) altered river nutrient flux and effects on coastal organic matter production and sediment accumulation; (7) seasonal balance between GPP and decomposition-respiration in terrestrial ecosystems in response to changes in temperature and precipitation; (8) successional processes in terrestrial ecosystems and formation of new plant associations in response to climatic change; (9) effects on soil nutrient availability, which amplifies ecosystem responses to climate change; (10) and responses of northern forests, tundra, and peatlands which have, until recently, been a sink for CO2. The potential effect of these processes on the rate of atmospheric CO2 concentration changes are estimated where possible, but not much quantitative information at a global scale is known, so uncertainty in these estimates is high. Each of these secondary feedbacks, however, has the potential of changing atmospheric CO2 concentration in magnitude similar to the effects of the direct human processes (fossil fuel burning and land clearing) responsible for the concern about global warming in the first place. It is therefore urgent that these uncertainties be resolved. Lines of research to accomplish this are suggested. C1 MONTEREY BAY AQUARIUM RES INST, PACIFIC GROVE, CA 93950 USA. UNIV MINNESOTA, NAT RESOURCES RES INST, DULUTH, MN 55811 USA. NASA, GODDARD SPACE FLIGHT CTR, INST SPACE STUDIES, NEW YORK, NY 10025 USA. BROWN UNIV, DEPT GEOL SCI, PROVIDENCE, RI 02912 USA. RP POST, WM (reprint author), OAK RIDGE NATL LAB, DIV ENVIRONM SCI, POB 2008, OAK RIDGE, TN 37831 USA. RI Pastor, John/F-6241-2011; Mulholland, Patrick/C-3142-2012; Post, Wilfred/B-8959-2012 NR 81 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0097-6156 J9 ACS SYM SER JI ACS Symp. Ser. PY 1992 VL 483 BP 392 EP 412 PG 21 WC Chemistry, Multidisciplinary SC Chemistry GA HG426 UT WOS:A1992HG42600027 ER PT J AU MENDELL, WW AF MENDELL, WW TI A STRATEGY FOR INVESTMENT IN SPACE RESOURCE UTILIZATION SO ACTA ASTRONAUTICA LA English DT Article AB During the first quarter of the next Century, space transportation systems will be capable of routine flights of humans and cargo to the Moon. The general acceptance of permanent human presence in space, as exemplified by at least two manned stations in LEO at that time, will lead to one or more staffed outposts on the Moon. Whether such outposts evolve into sustained, growing settlements will depend, in part, on whether the economic context attracts substantial private investment. A planetary surface provides a material and gravitational environment distinct from that of an orbiting space station and thus provides a setting familiar to non-aerospace sectors of terrestrial industry. Examination of current trends in terms of historical processes which operate on new frontiers suggests that the limited markets and unfamiliar technologies associated with space commercialization today may change dramatically in 20 years when lunar resources are accessible. However, the uncertainty and vagueness of such projections discourages investment at a useful scale unless a strategy for technology development can be implemented which provides tangible and marketable benefits in the intermediate term. At the present time technologies can be identified (a) that will be required (and therefore valuable) at the time of lunar settlement and (b) whose development can be planned to yield marketable intermediate products on Earth. Formation of pre-competitive, collaborative research consortia in the industrial sector could reduce technical and economic risk in the early stages and could promote a favorable political environment for the future growth of space activities. RP MENDELL, WW (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,DIV SOLAR SYST EXPLORAT,HOUSTON,TX 77058, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JAN PY 1992 VL 26 IS 1 BP 3 EP 10 DI 10.1016/0094-5765(92)90136-7 PG 8 WC Engineering, Aerospace SC Engineering GA HM477 UT WOS:A1992HM47700002 ER PT J AU BURKE, JD AF BURKE, JD TI LUNAR RESOURCES - EVALUATION AND DEVELOPMENT FOR USE IN A LUNAR BASE PROGRAM SO ACTA ASTRONAUTICA LA English DT Article AB Studies made to date on the use of solar system resources point strongly to the conclusion that all early uses will be within space programs, making them more efficient and fast-growing, as distinct from the later possibility of external outputs to the world economy. This paper examines several lunar resource utilization possibilities, going beyond the ones already documented (such as the use of regolith for shielding), in the context of an assumed international program for the human settlement of the Moon. RP BURKE, JD (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JAN PY 1992 VL 26 IS 1 BP 11 EP 13 DI 10.1016/0094-5765(92)90137-8 PG 3 WC Engineering, Aerospace SC Engineering GA HM477 UT WOS:A1992HM47700003 ER PT J AU KLEIN, KE WHITE, RJ AF KLEIN, KE WHITE, RJ TI HEAD-DOWN TILT BEDREST - HDT88 - AN INTERNATIONAL COLLABORATIVE EFFORT IN INTEGRATED SYSTEMS PHYSIOLOGY - FOREWORD SO ACTA PHYSIOLOGICA SCANDINAVICA LA English DT Editorial Material C1 NASA,DIV LIFE SCI,WASHINGTON,DC 20546. RP KLEIN, KE (reprint author), GERMAN AEROSP RES ESTAB,INST AEROSP MED,COLOGNE,GERMANY. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0001-6772 J9 ACTA PHYSIOL SCAND JI Acta Physiol. Scand. PY 1992 VL 144 SU 604 BP R1 EP R1 PG 1 WC Physiology SC Physiology GA HP723 UT WOS:A1992HP72300001 ER PT S AU RAINES, G AF RAINES, G BE Vankatwijk, J TI REAL-TIME ADA IN THE INTERNATIONAL SPACE STATION FREEDOM SO ADA : MOVING TOWARDS 2000 SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Proceedings Paper CT 11TH ADA / EUROPE INTERNATIONAL CONF : MOVING TOWARDS 2000 CY JUN 01-05, 1992 CL ZANDVOORT, NETHERLANDS RP RAINES, G (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA BERLIN SN 0302-9743 BN 3-540-55585-4 J9 LECT NOTES COMPUT SC PY 1992 VL 603 BP 9 EP 19 PG 11 GA BY26T UT WOS:A1992BY26T00003 ER PT J AU CONNELL, JW AF CONNELL, JW BE Boerio, FJ TI CHEMISTRY AND ADHESIVE PROPERTIES OF BLENDS OF ACETYLENE-TERMINATED MATERIALS SO ADHESION SOCIETY PROCEEDINGS OF THE FIFTEENTH ANNUAL MEETING LA English DT Proceedings Paper CT 15th Annual Meeting of the Adhesion-Society CY FEB 16-19, 1992 CL HILTON HEAD ISL, SC SP ADHES SOC C1 NASA,LANGLEY RES CTR,DIV MAT,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ADHESION SOCIETY PI BALTIMORE PA MARTIN MARIETTA LABORATORIES 1450 S ROLLING RD, BALTIMORE, MD 21227 PY 1992 BP 48 EP 50 PG 3 WC Materials Science, Coatings & Films SC Materials Science GA BA23L UT WOS:A1992BA23L00017 ER PT J AU PROGAR, DJ STCLAIR, TL AF PROGAR, DJ STCLAIR, TL BE Boerio, FJ TI POLYIMIDE BLENDS AS ADHESIVES SO ADHESION SOCIETY PROCEEDINGS OF THE FIFTEENTH ANNUAL MEETING LA English DT Proceedings Paper CT 15th Annual Meeting of the Adhesion-Society CY FEB 16-19, 1992 CL HILTON HEAD ISL, SC SP ADHES SOC C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ADHESION SOCIETY PI BALTIMORE PA MARTIN MARIETTA LABORATORIES 1450 S ROLLING RD, BALTIMORE, MD 21227 PY 1992 BP 103 EP 105 PG 3 WC Materials Science, Coatings & Films SC Materials Science GA BA23L UT WOS:A1992BA23L00040 ER PT J AU JENSEN, BJ AF JENSEN, BJ BE Boerio, FJ TI CONTROLLED MOLECULAR-WEIGHT IMIDE ARYLENE ETHER COPOLYMER ADHESIVES SO ADHESION SOCIETY PROCEEDINGS OF THE FIFTEENTH ANNUAL MEETING LA English DT Proceedings Paper CT 15th Annual Meeting of the Adhesion-Society CY FEB 16-19, 1992 CL HILTON HEAD ISL, SC SP ADHES SOC C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ADHESION SOCIETY PI BALTIMORE PA MARTIN MARIETTA LABORATORIES 1450 S ROLLING RD, BALTIMORE, MD 21227 PY 1992 BP 159 EP 161 PG 3 WC Materials Science, Coatings & Films SC Materials Science GA BA23L UT WOS:A1992BA23L00059 ER PT S AU LESH, JR AF LESH, JR BE Hagenauer, J TI THE NASA PROGRAM FOR OPTICAL DEEP-SPACE COMMUNICATIONS AT JPL SO ADVANCED METHODS FOR SATELLITE AND DEEP SPACE COMMUNICATIONS SE LECTURE NOTES IN CONTROL AND INFORMATION SCIENCES LA English DT Proceedings Paper CT INTERNATIONAL SEMINAR ON ADVANCED METHODS FOR SATELLITE AND DEEP SPACE COMMUNICATIONS CY SEP, 1992 CL BONN, GERMANY SP DEUT FORSCHUNGSANSTALT LUFTFAHRT & RAUMFAHRT RP LESH, JR (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA BERLIN SN 0170-8643 BN 3-540-55851-9 J9 LECT NOTES CONTR INF PY 1992 VL 182 BP 159 EP 179 PG 21 WC Engineering, Aerospace; Telecommunications SC Engineering; Telecommunications GA BY29C UT WOS:A1992BY29C00010 ER PT J AU TRAJMAR, S NICKEL, JC AF TRAJMAR, S NICKEL, JC TI CROSS-SECTION MEASUREMENTS FOR ELECTRON-IMPACT ON EXCITED ATOMIC SPECIES SO ADVANCES IN ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Review ID RARE-GAS ATOMS; LASER-INDUCED FLUORESCENCE; METASTABLE HELIUM-ATOMS; LOW-ENERGY ELECTRONS; MULTIMODE DYE-LASER; HIGH-INTENSITY BEAM; SODIUM ATOMS; COHERENCE PARAMETERS; EXCITATION-FUNCTIONS; VELOCITY DEPENDENCE C1 JET PROP LAB,PASADENA,CA 91109. RP TRAJMAR, S (reprint author), UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521, USA. NR 173 TC 27 Z9 27 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0065-2199 J9 ADV ATOM MOL OPT PHY JI Adv. At. Mol. Opt. Phys. PY 1992 VL 30 BP 45 EP 103 DI 10.1016/S1049-250X(08)60173-1 PG 59 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA MG072 UT WOS:A1992MG07200002 ER PT J AU HESSENIUS, KA RICHARDSON, PF AF HESSENIUS, KA RICHARDSON, PF TI NASA AND CFD - MAKING INVESTMENTS FOR THE FUTURE SO AEROSPACE AMERICA LA English DT Article RP HESSENIUS, KA (reprint author), NASA,DIV AERODYNAM,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0740-722X J9 AEROSPACE AM JI Aerosp. Am. PD JAN PY 1992 VL 30 IS 1 BP 28 EP & PG 0 WC Engineering, Aerospace SC Engineering GA GZ225 UT WOS:A1992GZ22500007 ER PT J AU KILGORE, EC AF KILGORE, EC TI UNITED-STATES COMMERCIAL COMPETITIVENESS SO AEROSPACE AMERICA LA English DT Article C1 NASA,WASHINGTON,DC 20546. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0740-722X J9 AEROSPACE AM JI Aerosp. Am. PD JAN PY 1992 VL 30 IS 1 BP B48 EP B48 PG 1 WC Engineering, Aerospace SC Engineering GA GZ225 UT WOS:A1992GZ22500013 ER PT J AU WOOD, DH WESTPHAL, RV AF WOOD, DH WESTPHAL, RV TI MEASUREMENTS OF THE FLOW AROUND A LIFTING-WING BODY JUNCTION SO AIAA JOURNAL LA English DT Article ID TURBULENT BOUNDARY-LAYER; VORTEX; VORTICES AB Detailed measurements of all three mean velocity components and rive of the six Reynolds stresses have been made around a model of a lifting-wing/body junction. The body was the flat working section floor of a small blower wind tunnel. Measurements of the surface pressure distribution on the NACA 0012 wing showed that the lift coefficient at the body surface was reduced by only 16% from the freestream value. It is shown that the near constancy of the bound vorticity requires the formation of axial vorticity within the body boundary layer. This vorticity was concentrated in the two legs of the necklace vortex formed near the leading edge of the wing. The magnitude of the vorticity was always greater in the leg that developed on the suction surface. By four chord lengths downstream of the trailing edge, the turbulence structure of the suction leg was qualitatively similar to that of a single vortex imbedded in a turbulent boundary layer. RP WOOD, DH (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 25 TC 8 Z9 8 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1992 VL 30 IS 1 BP 6 EP 12 DI 10.2514/3.10875 PG 7 WC Engineering, Aerospace SC Engineering GA GZ915 UT WOS:A1992GZ91500001 ER PT J AU MEADOWS, KR HARDIN, JC AF MEADOWS, KR HARDIN, JC TI REMOVAL OF SPURIOUS REFLECTIONS FROM COMPUTATIONAL FLUID DYNAMIC SOLUTIONS WITH THE COMPLEX CEPSTRUM SO AIAA JOURNAL LA English DT Article AB The complex cepstrum is shown to remove spurious reflections from artificial boundaries in computational fluid dynamic (CFD) solutions. First, the complex cepstrum theory is presented. A time sequence consisting of a direct signal and reflections is analyzed theoretically with the complex cepstrum, and it is shown that the direct signal uncontaminated by reflections may be recovered in the time domain. Next, the complex cepstrum is applied to one- and three-dimensional CFD solutions, and spurious reflections from the boundary conditions are removed. By eliminating spurious reflections introduced by artificial boundary conditions, the applicability of CFD methods to aeroacoustic problems is enhanced greatly. RP MEADOWS, KR (reprint author), NASA,AEROACOUST BRANCH,DIV ACOUST,MAIL STOP 461,HAMPTON,VA 23665, USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1992 VL 30 IS 1 BP 29 EP 34 DI 10.2514/3.10878 PG 6 WC Engineering, Aerospace SC Engineering GA GZ915 UT WOS:A1992GZ91500004 ER PT J AU FRINK, NT AF FRINK, NT TI UPWIND SCHEME FOR SOLVING THE EULER EQUATIONS ON UNSTRUCTURED TETRAHEDRAL MESHES SO AIAA JOURNAL LA English DT Article ID MULTIGRID SOLUTION AB An upwind scheme is presented for solving the three-dimensional Euler equations on unstructured tetrahedral meshes. Spatial discretization is accomplished by a cell-centered finite-volume formulation using flux-difference splitting. Higher-order differences are formed by a multidimensional linear reconstruction process. The solution gradients required for the higher-order differences are computed by a novel approach that yields highly resolved solutions in regions of smooth flow while avoiding oscillations across shocks without explicitly applying a limiter. Solutions are advanced in time by a three-stage Runge-Kutta time-stepping scheme with convergence accelerated to steady state by local time stepping and implicit residual smoothing. Transonic solutions are presented for two meshes around the ONERA M6 wing and demonstrate substantial accuracy and insensitivity to mesh size. RP FRINK, NT (reprint author), NASA,LANGLEY RES CTR,DIV APPL AERODYNAM,TRANSON AERODYNAM BRANCH,HAMPTON,VA 23665, USA. NR 19 TC 61 Z9 64 U1 1 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1992 VL 30 IS 1 BP 70 EP 77 DI 10.2514/3.10884 PG 8 WC Engineering, Aerospace SC Engineering GA GZ915 UT WOS:A1992GZ91500010 ER PT J AU DEGANI, D AF DEGANI, D TI INSTABILITIES OF FLOWS OVER BODIES AT LARGE INCIDENCE SO AIAA JOURNAL LA English DT Article ID CIRCULAR-CYLINDER; OGIVE-CYLINDER; DIFFERENCE AB The phenomena of the flow about an ogive-cylinder placed at incidence to an oncoming stream were numerically investigated for angles of attack of 60 and 80 deg. It was found that the flow around the cylindrical part of the body became unsteady, and vortex shedding was observed. For the 80-deg case, the corresponding Strouhal frequency was about 0.2, which is in agreement with the average value of the Strouhal frequency for flow around a two-dimensional cylinder. For both angles of attack, a small temporal disturbance of finite duration was sufficient to trigger the unsteadiness, which evolved to a finite amplitude fluctuation in the wake. Therefore, it seems possible that the origin of flow unsteadiness and vortex shedding in the wake is an absolute-type instability of the originally steady flow. When a permanent disturbance was also added near the tip of the body in the case of 60-deg angle of attack, a pair of steady, asymmetric vortices emerged from the vicinity of the body nose. These vortices could be the result of a convective-type instability of the originally symmetric now. It appears that both types of instability may coexist. RP DEGANI, D (reprint author), NASA,AMES RES CTR,FAC MECH ENGN,MOFFETT FIELD,CA 94035, USA. NR 34 TC 15 Z9 15 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1992 VL 30 IS 1 BP 94 EP 100 DI 10.2514/3.10887 PG 7 WC Engineering, Aerospace SC Engineering GA GZ915 UT WOS:A1992GZ91500013 ER PT J AU CONCUS, P FINN, R WEISLOGEL, M AF CONCUS, P FINN, R WEISLOGEL, M TI DROP-TOWER EXPERIMENTS FOR CAPILLARY SURFACES IN AN EXOTIC CONTAINER SO AIAA JOURNAL LA English DT Article AB Low-gravity drop-tower experiments were carried out for an "exotic" rotationally symmetric container, which admits an entire continuum of distinct equilibrium symmetric capillary free surfaces. It was found that an initial equilibrium planar interface, a member of the continuum, can reorient toward a nonsymmetric interface, as predicted by recent mathematical theory. C1 UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720. STANFORD UNIV,DEPT MATH,STANFORD,CA 94305. NASA,LEWIS RES CTR,DIV SPACE EXPT,CLEVELAND,OH 44135. RP CONCUS, P (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 8 TC 5 Z9 5 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1992 VL 30 IS 1 BP 134 EP 137 DI 10.2514/3.10892 PG 4 WC Engineering, Aerospace SC Engineering GA GZ915 UT WOS:A1992GZ91500018 ER PT J AU JEGLEY, DC LOPEZ, OF AF JEGLEY, DC LOPEZ, OF TI EFFECT OF COMPOSITE FABRICATION METHOD ON STRUCTURAL RESPONSE AND IMPACT DAMAGE SO AIAA JOURNAL LA English DT Article ID COMPRESSION AB Experimentally determined axial compressive failure loads, strains, and failure modes of composite flat panels and cylinders are presented. A comparison of two types of filament-wound flat graphite-epoxy panels indicates that the winding pattern can influence structural response. A comparison of hand laid-up tape and filament-wound composite cylinders indicates that fabrication method may not significantly influence the failure mode or average failure strain of thick-walled (radius-to-thickness ratio less than 15) graphite-epoxy cylinders. The interaction of manufacturing-induced features (fiber crossovers) and low-speed impact damage for graphite-epoxy specimens is also presented. Filament-wound flat panels with many fiber crossovers exhibited lower failure strains than did filament-wound panels without fiber crossovers for all impact speeds examined. Graphite-thermoplastic cylinders exhibited a significantly different failure mode from graphite-epoxy cylinders. C1 FAA,ATLANTA AIRCRAFT CERTIFICAT OFF,SMALL AIRPLANE DIRECTORATE,ATLANTA,GA 30349. RP JEGLEY, DC (reprint author), NASA,LANGLEY RES CTR,DIV STRUCT MECH,AIRCRAFT STRUCT BRANCH,HAMPTON,VA 23665, USA. NR 6 TC 1 Z9 1 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1992 VL 30 IS 1 BP 205 EP 213 DI 10.2514/3.10901 PG 9 WC Engineering, Aerospace SC Engineering GA GZ915 UT WOS:A1992GZ91500027 ER PT J AU GLASER, RJ KUO, CP WADA, BK AF GLASER, RJ KUO, CP WADA, BK TI IMPROVEMENT OF STRUCTURAL MODELS USING COVARIANCE ANALYSIS AND NONLINEAR GENERALIZED LEAST-SQUARES SO AIAA JOURNAL LA English DT Article AB The next generation of large, flexible space structures will be too light to support their own weight, requiring a system of structural supports for ground testing. The authors have proposed multiple boundary-condition testing (MBCT), using more than one support condition to reduce uncertainties associated with the supports. MBCT would revise the mass and stiffness matrix, analytically qualifying the structure for operation in space. The same procedure is applicable to other common test conditions, such as empty/loaded tanks and subsystem/system level tests. This paper examines three techniques for constructing the covariance matrix required by nonlinear generalized least squares (NGLS) to update structural models based on modal test data. The methods range from a complicated approach used to generate the simulation data (i.e., the correct answer) to a diagonal matrix based on only two constants. The results show that NGLS is very insensitive to assumptions about the covariance matrix, suggesting that a workable NGLS procedure is possible. The examples also indicate that the multiple boundary condition procedure more accurately reduces errors than individual boundary condition tests alone. RP GLASER, RJ (reprint author), CALTECH,JET PROP LAB,TECH STAFF,APPL TECHNOL SECT 354,PASADENA,CA 91109, USA. NR 8 TC 2 Z9 2 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1992 VL 30 IS 1 BP 226 EP 233 DI 10.2514/3.10903 PG 8 WC Engineering, Aerospace SC Engineering GA GZ915 UT WOS:A1992GZ91500029 ER PT J AU DEGANI, D TOBAK, M ZILLIAC, GG AF DEGANI, D TOBAK, M ZILLIAC, GG TI SURFACE FLOW PATTERNS ON AN OGIVE-CYLINDER AT INCIDENCE SO AIAA JOURNAL LA English DT Note RP DEGANI, D (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 9 TC 4 Z9 7 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1992 VL 30 IS 1 BP 272 EP 274 DI 10.2514/3.10911 PG 3 WC Engineering, Aerospace SC Engineering GA GZ915 UT WOS:A1992GZ91500037 ER PT B AU HENKEL, DP WOOD, JD AF HENKEL, DP WOOD, JD BE Peters, M Winkler, PJ TI A STUDY OF ALUMINUM-LITHIUM ALLOY SOLIDIFICATION USING ACOUSTIC-EMISSION TECHNIQUES SO ALUMINIUM-LITHIUM, VOLS 1 AND 2 LA English DT Proceedings Paper CT 6TH INTERNATIONAL ALUMINIUM-LITHIUM CONF CY OCT 07-11, 1991 CL GARMISCH PARTENKIRCHEN, GERMANY C1 NASA, LANGLEY RES CTR, ANALYT SERV & MAT INC, HAMPTON, VA 23665 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU DGM METALLURGY INFORMATION PI NEW YORK PA 150 E 27TH ST, #1A, NEW YORK, NY 10016-9049 USA BN 3-88355-180-5 PY 1992 BP 857 EP 862 PG 6 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BY20C UT WOS:A1992BY20C00135 ER PT J AU ODONNELL, CP KEIL, LC THRASHER, TN AF ODONNELL, CP KEIL, LC THRASHER, TN TI VASOPRESSIN RESPONSES TO UNLOADING ARTERIAL BARORECEPTORS DURING CARDIAC NERVE BLOCKADE IN CONSCIOUS DOGS SO AMERICAN JOURNAL OF PHYSIOLOGY LA English DT Article DE CAROTID SINUS RECEPTORS; CARDIAC RECEPTORS; PLASMA RENIN ACTIVITY; BLOOD PRESSURE; ADRENOCORTICOTROPIC HORMONE; CORTISOL; ARGININE VASOPRESSIN; ANTIDIURETIC HORMONE ID PLASMA VASOPRESSIN; CARDIOPULMONARY REGION; ARGININE VASOPRESSIN; VAGAL AFFERENTS; RELEASE; RECEPTORS; RENIN; HEMORRHAGE; INHIBITION; PRESSURE AB We examined the relative contributions of afferent input from the heart and from arterial baroreceptors in the stimulation of arginine vasopressin (AVP) secretion in response to hypotension caused by thoracic inferior vena caval constriction (TIVCC). Afferent input from cardiac receptors was reversibly blocked by infusing 2% procaine into the pericardial space to anesthetize the cardiac nerves. Acute cardiac nerve blockade (CNB) alone caused a rise in mean arterial pressure (MAP) of 24 +/- 3 mmHg but no change in plasma AVP. If the rise in MAP was prevented by TIVCC, plasma AVP increased by 39 +/- 15 pg/ml, and if MAP was allowed to increase and then was forced back to control by TIVCC, plasma AVP increased by 34 +/- 15 pg/ml. Thus the rise in MAP during CNB stimulated arterial baroreceptors, which in turn compensated for the loss of inhibitory input from cardiac receptors on AVP secretion. These results indicate that the maximum secretory response resulting from complete unloading of cardiac receptors at a normal MAP results in a mean increase in plasma AVP of 39 pg/ml in this group of dogs. When MAP was reduced 25% below control levels (from 95 +/- 5 to 69 +/- 3 mmHg) by TIVCC during pericardial saline infusion, plasma AVP increased by 79 +/- 42 pg/ml. However, the same degree of hypotension during CNB (MAP was reduced from 120 +/- 5 to 71 +/- 3 mmHg) led to a greater (P < 0.05) increase in plasma AVP of 130 +/- 33 pg/ml. Because completely unloading cardiac receptors can account for an increase of only 39 pg/ml on average in this group of dogs, the remainder of the increase in plasma AVP must be due to other sources of stimulation. We suggest that the principal stimulus to AVP secretion after acute CNB in these studies arises from unloading the arterial baroreceptors. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP ODONNELL, CP (reprint author), UNIV CALIF SAN FRANCISCO,SCH MED,DEPT PHYSIOL,SAN FRANCISCO,CA 94143, USA. FU NHLBI NIH HHS [HL-41313] NR 24 TC 15 Z9 15 U1 0 U2 0 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0002-9513 J9 AM J PHYSIOL JI Am. J. Physiol. PD JAN PY 1992 VL 262 IS 1 BP R51 EP R60 PN 2 PG 10 WC Physiology SC Physiology GA HA743 UT WOS:A1992HA74300052 PM 1733340 ER PT J AU REBEIZ, GM RUTLEDGE, DB AF REBEIZ, GM RUTLEDGE, DB TI INTEGRATED HORN ANTENNAS FOR MILLIMETER-WAVE APPLICATIONS SO ANNALES DES TELECOMMUNICATIONS-ANNALS OF TELECOMMUNICATIONS LA English DT Article DE HORN ANTENNA; MICROWAVE ANTENNA; MILLIMETRIC WAVE; ANTENNA ARRAY; PLANE ANTENNA; ORTHOGONAL POLARIZATION ID SLOT ANTENNAS AB This paper reviews the development of integrated horn antennas since their introduction in 1987. The integrated horn is fabricated by suspending a dipole antenna on a thin dielectric membrane in a pyramidal cavity etched in silicon. Recent progress resulted in optimized low and high-gain designs with single and double-polarizations for remote-sensing and communication applications. A fullwave analysis technique have resulted in an integrated antenna with performance comparable to that of waveguide-fed corrugated horn antennas. The integrated horn design can be easily extended to large arrays for imaging and phased array applications while still leaving plenty of room for the RF and IF processing circuitry. Theoretical and experimental results at microwave frequencies and at 90, 240 and 802 GHz will be presented. C1 CALTECH,DIV ENGN & APPL SCI,PASADENA,CA 91125. RP REBEIZ, GM (reprint author), UNIV MICHIGAN,DEPT ELECT ENGN & COMP SCI,NASA,CTR SPACE TERAHERTZ TECHNOL,ANN ARBOR,MI 48109, USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU PRESSES POLYTECHNIQUES ET UNIVERSITAIRES ROMANDES PI LAUSANNE PA EPFL-ECUBLENS, CENTRE MIDI, CH-1015 LAUSANNE, SWITZERLAND SN 0003-4347 J9 ANN TELECOMMUN JI Ann. Telecommun.-Ann Telecommun. PD JAN-FEB PY 1992 VL 47 IS 1-2 BP 38 EP 48 PG 11 WC Telecommunications SC Telecommunications GA HR408 UT WOS:A1992HR40800003 ER PT J AU DWEK, E ARENDT, RG AF DWEK, E ARENDT, RG TI DUST-GAS INTERACTIONS AND THE INFRARED-EMISSION FROM HOT ASTROPHYSICAL PLASMAS SO ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS LA English DT Review DE INTERSTELLAR DUST; SUPERNOVA REMNANTS; GALAXIES; GALAXY CLUSTERS ID SUPER-NOVA REMNANT; INTER-STELLAR SPACE; HEAVY ELEMENT DEPLETION; RAY LUMINOUS CLUSTERS; SHOCK-HEATED DUST; H-I SHELLS; INTERSTELLAR GRAINS; CASSIOPEIA-A; TEMPERATURE-FLUCTUATIONS; CRAB-NEBULA RP DWEK, E (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. NR 221 TC 96 Z9 96 U1 0 U2 1 PU ANNUAL REVIEWS INC PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 SN 0066-4146 J9 ANNU REV ASTRON ASTR JI Annu. Rev. Astron. Astrophys. PY 1992 VL 30 BP 11 EP 50 PG 40 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JN532 UT WOS:A1992JN53200002 ER PT J AU ELITZUR, M AF ELITZUR, M TI ASTRONOMICAL MASERS SO ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS LA English DT Review DE LATE-TYPE STARS; STAR-FORMING REGIONS; SHOCK WAVES; INTERSTELLAR MOLECULES; MAGNETIC FIELDS ID H-II REGIONS; STAR-FORMING REGIONS; MILLIMETER RECOMBINATION LINES; VLBI SYNTHESIS OBSERVATIONS; SUBMILLIMETER WATER MASERS; STRONG MAGNETIC-FIELDS; STRONG METHANOL MASERS; MASS-LOSS RATES; OH-IR SOURCES; SIO MASERS C1 NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RP UNIV KENTUCKY, DEPT PHYS & ASTRON, LEXINGTON, KY 40506 USA. NR 165 TC 104 Z9 106 U1 2 U2 7 PU ANNUAL REVIEWS PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 USA SN 0066-4146 J9 ANNU REV ASTRON ASTR JI Annu. Rev. Astron. Astrophys. PY 1992 VL 30 BP 75 EP 112 PG 38 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JN532 UT WOS:A1992JN53200004 ER PT J AU SHAO, M COLAVITA, MM AF SHAO, M COLAVITA, MM TI LONG-BASE-LINE OPTICAL AND INFRARED STELLAR INTERFEROMETRY SO ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS LA English DT Review DE ASTROMETRY; HIGH RESOLUTION IMAGING; ADAPTIVE OPTICS ID ANGULAR DIAMETER MEASUREMENTS; MICRON SPATIAL INTERFEROMETRY; LASER GUIDE STARS; MICHELSON INTERFEROMETRY; ADAPTIVE OPTICS; SPECKLE INTERFEROMETRY; APERTURE SYNTHESIS; SYNTHESIS IMAGES; LARGE TELESCOPE; ALPHA-ORIONIS RP SHAO, M (reprint author), JET PROP LAB,OPT SCI & APPLICAT SECT,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 173 TC 127 Z9 130 U1 1 U2 2 PU ANNUAL REVIEWS INC PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 SN 0066-4146 J9 ANNU REV ASTRON ASTR JI Annu. Rev. Astron. Astrophys. PY 1992 VL 30 BP 457 EP 498 PG 42 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JN532 UT WOS:A1992JN53200014 ER PT J AU ONUCHIC, JN BERATAN, DN WINKLER, JR GRAY, HB AF ONUCHIC, JN BERATAN, DN WINKLER, JR GRAY, HB TI PATHWAY ANALYSIS OF PROTEIN ELECTRON-TRANSFER REACTIONS SO ANNUAL REVIEW OF BIOPHYSICS AND BIOMOLECULAR STRUCTURE LA English DT Review DE ELECTRON-TUNNELING PATHWAYS; ELECTRON COUPLING; RUTHENIUM-MODIFIED PROTEINS; CYTOCHROME-C; MYOGLOBIN ID MODIFIED CYTOCHROME-C; FREE-ENERGY DEPENDENCE; TUNNELING PATHWAYS; TRANSFER KINETICS; MATRIX-ELEMENTS; MODIFIED MYOGLOBIN; REACTION DYNAMICS; REACTION CENTERS; QUANTUM; HEME C1 JET PROP LAB,PASADENA,CA 91109. CALTECH,BECKMAN INST,PASADENA,CA 91125. UNIV SAO PAULO,INST FIS & QUIM SAO CARLOS,BR-13560 SAO CARLOS,SP,BRAZIL. RP ONUCHIC, JN (reprint author), UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093, USA. RI Beratan, David/C-5098-2011 NR 81 TC 338 Z9 339 U1 6 U2 32 PU ANNUAL REVIEWS INC PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 SN 1056-8700 J9 ANNU REV BIOPH BIOM JI Annu. Rev. Biophys. Biomolec. Struct. PY 1992 VL 21 BP 349 EP 377 DI 10.1146/annurev.biophys.21.1.349 PG 29 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA JD039 UT WOS:A1992JD03900015 PM 1326356 ER PT J AU FIELD, CB CHAPIN, FS MATSON, PA MOONEY, HA AF FIELD, CB CHAPIN, FS MATSON, PA MOONEY, HA TI RESPONSES OF TERRESTRIAL ECOSYSTEMS TO THE CHANGING ATMOSPHERE - A RESOURCE-BASED APPROACH SO ANNUAL REVIEW OF ECOLOGY AND SYSTEMATICS LA English DT Review DE GLOBAL CHANGE; BIOGEOCHEMISTRY; TERRESTRIAL BIOSPHERE; CARBON CYCLE; NITROGEN CYCLE ID NITROGEN-USE EFFICIENCY; TEMPERATE FOREST ECOSYSTEMS; ELEVATED CO2 CONCENTRATIONS; CARBON NUTRIENT BALANCE; ALASKAN TUSSOCK TUNDRA; SOURCE-SINK RELATIONS; HARDWOOD LEAF LITTER; WATER-USE EFFICIENCY; ALPINE LIFE ZONE; L KARST STANDS C1 UNIV CALIF BERKELEY, DEPT INTEGRAT BIOL, BERKELEY, CA 94720 USA. NASA, AMES RES CTR, DIV EARTH SYST SCI, MOFFETT FIELD, CA 94035 USA. STANFORD UNIV, DEPT BIOL SCI, STANFORD, CA 94305 USA. RP FIELD, CB (reprint author), CARNEGIE INST WASHINGTON, DEPT PLANT BIOL, STANFORD, CA 94305 USA. OI Chapin III, F Stuart/0000-0002-2558-9910 NR 255 TC 277 Z9 297 U1 5 U2 63 PU ANNUAL REVIEWS PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 USA SN 0066-4162 J9 ANNU REV ECOL SYST JI Annu. Rev. Ecol. Syst. PY 1992 VL 23 BP 201 EP 235 DI 10.1146/annurev.es.23.110192.001221 PG 35 WC Ecology; Evolutionary Biology SC Environmental Sciences & Ecology; Evolutionary Biology GA JZ281 UT WOS:A1992JZ28100009 ER PT J AU SHARIFF, K LEONARD, A AF SHARIFF, K LEONARD, A TI VORTEX RINGS SO ANNUAL REVIEW OF FLUID MECHANICS LA English DT Article DE VORTICITY DYNAMICS; VISCOUS FLOWS; INCOMPRESSIBLE AND INVISCID FLOWS; STARTING VORTICES; TURBULENT VORTICES; VORTEX SOUND ID CONTROLLED EXCITATION; TURBULENT-FLOW; AXIAL-FLOW; VORTICES; STEADY; INSTABILITY; SURFACE; MOTION; STABILITY; DYNAMICS C1 CALTECH, GRAD AERONAUT LABS, PASADENA, CA 91125 USA. RP NASA, AMES RES CTR, COMP FLUID DYNAM BRANCH, MOFFETT FIELD, CA 94035 USA. NR 142 TC 148 Z9 148 U1 10 U2 29 PU ANNUAL REVIEWS PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 USA SN 0066-4189 J9 ANNU REV FLUID MECH JI Annu. Rev. Fluid Mech. PY 1992 VL 24 BP U235 EP U279 PG 45 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA GY973 UT WOS:A1992GY97300011 ER PT J AU LANE, HW SCHULZ, LO AF LANE, HW SCHULZ, LO TI NUTRITIONAL QUESTIONS RELEVANT TO SPACE-FLIGHT SO ANNUAL REVIEW OF NUTRITION LA English DT Review DE BODY COMPOSITION; ENERGY REQUIREMENTS; NUTRIENT REQUIREMENTS ID AMINO-ACIDS; BED-REST; METABOLISM; RESPONSIVENESS; SPACEFLIGHT; PROTEIN C1 UNIV WISCONSIN,DEPT HLTH SCI,MILWAUKEE,WI 53201. RP LANE, HW (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,BIOMED OPERAT & RES BRANCH,HOUSTON,TX 77058, USA. NR 52 TC 17 Z9 17 U1 0 U2 0 PU ANNUAL REVIEWS INC PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 SN 0199-9885 J9 ANNU REV NUTR JI Annu. Rev. Nutr. PY 1992 VL 12 BP 257 EP 278 DI 10.1146/annurev.nu.12.070192.001353 PG 22 WC Nutrition & Dietetics SC Nutrition & Dietetics GA JG467 UT WOS:A1992JG46700013 PM 1503806 ER PT J AU RAMAKRISHNAN, R WATSON, WR AF RAMAKRISHNAN, R WATSON, WR TI DESIGN CURVES FOR RECTANGULAR SPLITTER SILENCERS SO APPLIED ACOUSTICS LA English DT Article AB Passive silencers with acoustic fill such as glass fiber, rock wool or foam are commonly used in conventional heating, ventilation and air conditioning systems. Acoustic performance can be estimated for a few basic silencers through the use of design curves available in the literature. Recently, a large microcomputer data base using design curves generated to cover the entire range of manufactured rectangular silencers was made available. Details of the design curves and the mathematical model are presented. Insertion loss of the silencers is estimated from attenuation rates calculated from a finite element method. Unlike existing models, the present method considers multimodal acoustic propagation and can be extended to account for the effects of shearing airflows in the airway. The sound-absorbing material is considered to be bulk reacting. Wave propagation in the material is thus included. Design curves are grouped by using three nondimensional parameters, therby covering the entire line of conventional rectangular duct silencers. Results from the model are compared to least attenuated mode predictions and to actual test data. The results show that the present model gives better predictions than least attenuated mode models. Good comparison between the current model and the test data was also observed. Development of a computer program for a quick estimation of the insertion loss is also described. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 9 Z9 9 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0003-682X J9 APPL ACOUST JI Appl. Acoust. PY 1992 VL 35 IS 1 BP 1 EP 24 DI 10.1016/0003-682X(92)90033-O PG 24 WC Acoustics SC Acoustics GA HF548 UT WOS:A1992HF54800001 ER PT J AU STEINBERG, NA BLUM, JS HOCHSTEIN, L OREMLAND, RS AF STEINBERG, NA BLUM, JS HOCHSTEIN, L OREMLAND, RS TI NITRATE IS A PREFERRED ELECTRON-ACCEPTOR FOR GROWTH OF FRESH-WATER SELENATE-RESPIRING BACTERIA SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Note ID SELENIUM; REDUCTION; SEDIMENTS; RESPIRATION; ACETYLENE; CULTURE AB An anaerobic, freshwater enrichment grew with either nitrate or selenate as an electron acceptor. With both ions present, nitrate reduction preceded selenate reduction. An isolate from the enrichment grew on either ion, but the presence of nitrate precluded the reduction of selenate. Stock cultures of denitrifiers grew anaerobically on nitrate but not on selenate. C1 US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 22 TC 40 Z9 40 U1 1 U2 6 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JAN PY 1992 VL 58 IS 1 BP 426 EP 428 PG 3 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA GY253 UT WOS:A1992GY25300067 PM 16348638 ER PT J AU CASNER, SM AF CASNER, SM TI ENVISIONING INFORMATION - TUFTE,ER SO APPLIED COGNITIVE PSYCHOLOGY LA English DT Book Review RP CASNER, SM (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0888-4080 J9 APPL COGNITIVE PSYCH JI Appl. Cogn. Psychol. PD JAN-FEB PY 1992 VL 6 IS 1 BP 91 EP 92 DI 10.1002/acp.2350060106 PG 2 WC Psychology, Experimental SC Psychology GA HD715 UT WOS:A1992HD71500005 ER PT J AU SHU, CW ZANG, TA ERLEBACHER, G WHITAKER, D OSHER, S AF SHU, CW ZANG, TA ERLEBACHER, G WHITAKER, D OSHER, S TI HIGH-ORDER ENO SCHEMES APPLIED TO 2-DIMENSIONAL AND 3-DIMENSIONAL COMPRESSIBLE FLOW SO APPLIED NUMERICAL MATHEMATICS LA English DT Article ID SHOCK-CAPTURING SCHEMES; EFFICIENT IMPLEMENTATION AB High-order essentially non-oscillatory (ENO) finite-difference schemes are applied to the two- and three-dimensional compressible Euler and Navier-Stokes equations. Practical issues, such as vectorization, efficiency of coding, cost comparison with other numerical methods and accuracy degeneracy effects, are discussed. Numerical examples are provided which are representative of computational problems of current interest in transition and turbulence physics. These require both non-oscillatory shock capturing and high resolution for detailed structures in the smooth regions and demonstrate the advantage of ENO schemes. C1 NASA, LANGLEY RES CTR, THEORET FLOW PHYS BRANCH, HAMPTON, VA 23665 USA. NASA, LANGLEY RES CTR, INST COMP APPLICAT SCI & ENGN, HAMPTON, VA 23665 USA. NASA, LANGLEY RES CTR, COMPUTAT AERODYNAM BRANCH, HAMPTON, VA 23665 USA. UNIV CALIF LOS ANGELES, DEPT MATH, LOS ANGELES, CA 90024 USA. RP SHU, CW (reprint author), BROWN UNIV, DEPT APPL MATH, PROVIDENCE, RI 02912 USA. RI Shu, Chi-Wang/A-3216-2013 OI Shu, Chi-Wang/0000-0001-7720-9564 NR 27 TC 50 Z9 57 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9274 EI 1873-5460 J9 APPL NUMER MATH JI Appl. Numer. Math. PD JAN PY 1992 VL 9 IS 1 BP 45 EP 71 DI 10.1016/0168-9274(92)90066-M PG 27 WC Mathematics, Applied SC Mathematics GA HC241 UT WOS:A1992HC24100004 ER PT J AU PAGE, LA CHENG, ES MEYER, SS AF PAGE, LA CHENG, ES MEYER, SS TI RESONANT CRYOGENIC CHOPPER SO APPLIED OPTICS LA English DT Article AB We describe the design, construction, and performance of a resonant cryogenic chopper that operates at 4.2 K. The chopper is mechanically and thermally robust; it can occult a 2.54-cm aperture at 4.5 Hz while dissipating approximately 1 mW. Both the stator and rotor magnetic fields are controllable to allow for performance optimization and to help in measuring any possible interference effects. Data on long-term amplitude stability are presented. C1 PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP PAGE, LA (reprint author), MIT,DEPT PHYS,ROOM 20F-001,CAMBRIDGE,MA 02139, USA. OI Page, Lyman/0000-0002-9828-3525 NR 5 TC 3 Z9 3 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JAN 1 PY 1992 VL 31 IS 1 BP 95 EP 100 PG 6 WC Optics SC Optics GA HA509 UT WOS:A1992HA50900013 PM 20717376 ER PT J AU HERZIG, H FLEETWOOD, CM TOFT, AR AF HERZIG, H FLEETWOOD, CM TOFT, AR TI VARIABILITY IN THE VACUUM-ULTRAVIOLET TRANSMITTANCE OF MAGNESIUM FLUORIDE WINDOWS SO APPLIED OPTICS LA English DT Article DE TRANSMITTANCE; MAGNESIUM FLUORIDE; WINDOWS; VACUUM ULTRAVIOLET AB In the course of the development of a domed magnesium fluoride detector window for the Space Telescope Imaging Spectrograph, slated to be a second-generation instrument aboard the Hubble Space Telescope, sample window materials from various commercial sources displayed a wide variability in vacuum ultraviolet transmittance. As a result a test program was undertaken in cooperation with the supplier of a prototype domed window to maximize transmittance. Results of the program have provided clues to the causes of the variations experienced, and they Point to careful selection of raw materials and strict process control to achieve optimization. RP HERZIG, H (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 6 TC 3 Z9 3 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JAN 1 PY 1992 VL 31 IS 1 BP 110 EP 114 PG 5 WC Optics SC Optics GA HA509 UT WOS:A1992HA50900016 PM 20717379 ER PT J AU WEI, TH HAGAN, DJ SENCE, MJ VANSTRYLAND, EW PERRY, JW COULTER, DR AF WEI, TH HAGAN, DJ SENCE, MJ VANSTRYLAND, EW PERRY, JW COULTER, DR TI DIRECT MEASUREMENTS OF NONLINEAR ABSORPTION AND REFRACTION IN SOLUTIONS OF PHTHALOCYANINES SO APPLIED PHYSICS B-PHOTOPHYSICS AND LASER CHEMISTRY LA English DT Article ID OPTICAL NONLINEARITIES; SINGLE-BEAM AB We report direct measurements of the excited singlet state absorption cross section and the associated nonlinear refractive cross section using picosecond pulses at 532 nm in solutions of phthalocyanine and naphthalocyanine dyes. By monitoring the transmittance and far field spatial beam distortion for different pulsewidths in the picosecond regime, we determine that both the nonlinear absorption and refraction are fluence (energy per unit area) rather than irradiance dependent. Thus, excited state absorption (ESA) is the dominant nonlinear absorption process, and the observed nonlinear refraction is also due to real population excitation. C1 UNIV CENT FLORIDA,DEPT PHYS,ORLANDO,FL 32816. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP WEI, TH (reprint author), UNIV CENT FLORIDA,CTR RES ELECTROOPT & LASERS,ORLANDO,FL 32816, USA. RI Hagan, David/H-2204-2011; Perry, Joseph/B-7191-2011 OI Hagan, David/0000-0003-2713-1767; Perry, Joseph/0000-0003-1101-7337 NR 23 TC 273 Z9 286 U1 0 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0721-7269 J9 APPL PHYS B-PHOTO PD JAN PY 1992 VL 54 IS 1 BP 46 EP 51 DI 10.1007/BF00331733 PG 6 WC Physics, Applied SC Physics GA HB490 UT WOS:A1992HB49000006 ER PT B AU ALLAMANDOLA, LJ AF ALLAMANDOLA, LJ BE SINGH, PD TI ISO AND LABORATORY ASTROPHYSICS SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP ALLAMANDOLA, LJ (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 15 EP 16 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00004 ER PT B AU SALAMA, F ALLAMANDOLA, LJ AF SALAMA, F ALLAMANDOLA, LJ BE SINGH, PD TI UV-VISIBLE AND NEAR IR ABSORPTION CHARACTERISTICS OF INTERSTELLAR PAHS .1. C10H8+ SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP SALAMA, F (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MS 245-6,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 25 EP 26 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00009 ER PT B AU HUDGINS, DM SANDFORD, SA TIELENS, AGGM ALLAMANDOLA, LJ AF HUDGINS, DM SANDFORD, SA TIELENS, AGGM ALLAMANDOLA, LJ BE SINGH, PD TI INFRARED-SPECTROSCOPY OF INTERSTELLAR AND SOLAR-SYSTEM ICE ANALOGS - MEASUREMENT OF OPTICAL-CONSTANTS SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP HUDGINS, DM (reprint author), NASA,AMES RES CTR,MS 245-6,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 27 EP 28 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00010 ER PT B AU SCHUTTE, WA ALLAMANDOLA, LJ SANDFORD, SA AF SCHUTTE, WA ALLAMANDOLA, LJ SANDFORD, SA BE SINGH, PD TI FORMATION OF ORGANIC-MOLECULES BY FORMALDEHYDE REACTIONS IN ASTROPHYSICAL ICES AT VERY LOW-TEMPERATURES SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP SCHUTTE, WA (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MS 245-6,MOFFETT FIELD,CA 94035, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 29 EP 30 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00011 ER PT B AU NUTH, JA AF NUTH, JA BE SINGH, PD TI METAMORPHISM OF COSMIC DUST - DIAGNOSTIC INFRARED SIGNATURES SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP NUTH, JA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTROCHEM BRANCH,CODE 691,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 39 EP 40 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00013 ER PT B AU ALLAMANDOLA, LJ AF ALLAMANDOLA, LJ BE SINGH, PD TI GRAIN SPECTROSCOPY SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP ALLAMANDOLA, LJ (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 65 EP 72 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00017 ER PT B AU TIELENS, AGGM AF TIELENS, AGGM BE SINGH, PD TI THE D/H RATIO IN MOLECULAR CLOUDS SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP TIELENS, AGGM (reprint author), NASA,AMES RES CTR,MS 245-3,MOFFETT FIELD,CA 94035, USA. NR 0 TC 10 Z9 10 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 91 EP 95 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00021 ER PT B AU SANDFORD, SA ALLAMANDOLA, LJ TIELENS, AGGM SELLGREN, K TAPIA, M PENDLETON, Y AF SANDFORD, SA ALLAMANDOLA, LJ TIELENS, AGGM SELLGREN, K TAPIA, M PENDLETON, Y BE SINGH, PD TI THE INTERSTELLAR C-H STRETCHING BAND NEAR 3.4-MU-M - CONSTRAINTS ON THE COMPOSITION OF ORGANIC MATERIAL IN THE DIFFUSE ISM SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP SANDFORD, SA (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 KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 133 EP 134 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00029 ER PT B AU SCHUTTE, WA TIELENS, AGGM ALLAMANDOLA, LJ AF SCHUTTE, WA TIELENS, AGGM ALLAMANDOLA, LJ BE SINGH, PD TI THEORETICAL MODELING OF THE INFRARED FLUORESCENCE BY INTERSTELLAR POLYCYCLIC AROMATIC-HYDROCARBONS SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP SCHUTTE, WA (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MS 245-6,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 137 EP 138 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00031 ER PT B AU CHARNLEY, SB ROBERGE, WG AF CHARNLEY, SB ROBERGE, WG BE SINGH, PD TI CHEMICAL EFFECTS OF SHEAR ALFVEN WAVES IN MOLECULAR CLOUDS SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP CHARNLEY, SB (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 155 EP 156 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00035 ER PT B AU BUTNER, HM AF BUTNER, HM BE SINGH, PD TI ABUNDANCE OF DCO+ IN NEARBY MOLECULAR CLOUDS SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP BUTNER, HM (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 169 EP 170 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00038 ER PT B AU LANGER, WD AF LANGER, WD BE SINGH, PD TI CARBON ISOTOPIC CHEMISTRY SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP LANGER, WD (reprint author), JET PROP LAB,MS 169-506,PASADENA,CA 91109, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 193 EP 197 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00045 ER PT B AU CHARNLEY, SB AF CHARNLEY, SB BE SINGH, PD TI CHEMICAL-MODELS OF ACTIVE REGIONS SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP CHARNLEY, SB (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 199 EP 203 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00046 ER PT B AU RUBIN, RH ERICKSON, EF HAAS, MR COLGAN, SWJ SIMPSON, JP DUFOUR, RJ AF RUBIN, RH ERICKSON, EF HAAS, MR COLGAN, SWJ SIMPSON, JP DUFOUR, RJ BE SINGH, PD TI ABUNDANCES OF REFRACTORY ELEMENTS IN THE ORION NEBULA SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP RUBIN, RH (reprint author), NASA,AMES RES CTR,MS 245-6,MOFFETT FIELD,CA 94035, USA. RI Colgan, Sean/M-4742-2014 NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 281 EP 283 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00063 ER PT B AU CHARNLEY, SB TIELENS, AGGM AF CHARNLEY, SB TIELENS, AGGM BE SINGH, PD TI HOT CORE CHEMISTRY - GAS-PHASE MOLECULE FORMATION INSITU SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP CHARNLEY, SB (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 317 EP 318 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00069 ER PT B AU SALAMA, F SANDFORD, SA ALLAMANDOLA, LJ AF SALAMA, F SANDFORD, SA ALLAMANDOLA, LJ BE SINGH, PD TI LABORATORY STUDIES OF PLANETARY MOLECULES AND ICES - THE CASE OF IO SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP SALAMA, F (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MS 245-6,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 435 EP 436 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00105 ER PT B AU BLAKE, DF ALLAMANDOLA, L FREUND, F SANDFORD, S HUDGINS, D AF BLAKE, DF ALLAMANDOLA, L FREUND, F SANDFORD, S HUDGINS, D BE SINGH, PD TI TYPE-II CLATHRATE HYDRATE FORMATION IN COMETARY ICE ANALOGS IN VACUO SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP BLAKE, DF (reprint author), NASA,AMES RES CTR,MS 239-4,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 437 EP 438 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00106 ER PT B AU NUTH, JA AF NUTH, JA BE SINGH, PD TI A DIAGNOSTIC SPECTRAL INDICATOR OF THE EXPOSURE AGE OF AN ASTEROIDAL SURFACE SO ASTROCHEMISTRY OF COSMIC PHENOMENA SE IAU SYMPOSIA LA English DT Proceedings Paper CT 150TH SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : ASTROCHEMISTRY OF COSMIC PHENOMENA CY AUG 05-09, 1991 CL SAO PAULO, BRAZIL SP INT ASTRON UNION RP NUTH, JA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTROCHEM BRANCH,CODE 691,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1825-0 J9 IAU SYMP PY 1992 VL 150 BP 461 EP 462 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW54C UT WOS:A1992BW54C00114 ER PT J AU HARVEY, BR JAUNCEY, DL WHITE, GL NOTHNAGEL, A NICOLSON, GD REYNOLDS, JE MORABITO, DD BARTEL, N AF HARVEY, BR JAUNCEY, DL WHITE, GL NOTHNAGEL, A NICOLSON, GD REYNOLDS, JE MORABITO, DD BARTEL, N TI ACCURATE RADIO AND OPTICAL POSITIONS FOR SOUTHERN RADIO-SOURCES SO ASTRONOMICAL JOURNAL LA English DT Article ID APPARENT PLACE COMPUTATIONS; IAU SYSTEM; TRANSFORMATION; CATALOG AB Accurate radio positions with a precision of about 0.01 arcsec are reported for eight compact extragalactic radio sources south of -45-degrees declination. The radio positions were determined using Very Long Baseline Interferometry (VLBI) at 8.4 GHz on the 9589 km Tidbinbilla (Australia) to Hartebeesthoek (South Africa) baseline. The sources were selected from the Parkes Catalogue to be strong, flat-spectrum radio sources with bright optical QSO counterparts. Optical positions of the QSOs were also measured from the ESO B Sky Survey plates with respect to stars from the Perth 70 Catalogue, to an accuracy of about 0.19 arcsec rms. These radio and optical positions are as precise as any presently available in the far southern sky. A comparison of the radio and optical positions confirms the estimated optical position errors and shows that there is overall agreement at the 0.1 arcsec level between the radio and Perth 70 optical reference frames in the far south. C1 CSIRO,AUSTRALIA TELESCOPE NATL FACIL,EPPING,NSW 2121,AUSTRALIA. HARTEBEESTHOEK RADIO ASTRON OBSERV,KRUGERSDORP 1740,SOUTH AFRICA. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,CANBERRA,ACT 2601,AUSTRALIA. CALTECH,JET PROP LAB,PASADENA,CA 91109. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. NR 15 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD JAN PY 1992 VL 103 IS 1 BP 229 EP 233 DI 10.1086/116055 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GX221 UT WOS:A1992GX22100020 ER PT J AU OLSON, EC SCHAEFER, BE LINES, R LINES, H FRIED, RE AF OLSON, EC SCHAEFER, BE LINES, R LINES, H FRIED, RE TI A NEW INVESTIGATION OF PHOTOMETRIC CHANGES IN RW PERSEI SO ASTRONOMICAL JOURNAL LA English DT Article ID LIGHT AB We have obtained new photoelectric observations of RW Per, and carried out photometric solutions for these data, for earlier photoelectric observations, and for archival photographic observations. We conclude that no third light exists in this binary, and that the original nodal variation explanation for historical changes in the depth of primary eclipse is therefore incorrect. We suggest a revised nodal variation hypothesis. We also note that these changes could have been produced by a gradual increase in the polar radius of the hot star, perhaps related to a change in that star's rotational velocity. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. BRAESIDE OBSERV,FLAGSTAFF,AZ 86002. RP OLSON, EC (reprint author), UNIV ILLINOIS,DEPT ASTRON,URBANA,IL 61801, USA. NR 12 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD JAN PY 1992 VL 103 IS 1 BP 256 EP 262 DI 10.1086/116058 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GX221 UT WOS:A1992GX22100023 ER PT J AU YEOMANS, DK CHODAS, PW KEESEY, MS OSTRO, SJ CHANDLER, JF SHAPIRO, II AF YEOMANS, DK CHODAS, PW KEESEY, MS OSTRO, SJ CHANDLER, JF SHAPIRO, II TI ASTEROID AND COMET ORBITS USING RADAR DATA SO ASTRONOMICAL JOURNAL LA English DT Article ID ARAKI-ALCOCK 1983D; IMAGES AB For the 30 asteroids and 4 comets for which radar astrometric data were given by Ostro [AJ, 102, 1490 (1991b)], orbits have been computed using both the radar and the existing optical measurements. The techniques required to process radar data in orbit determination solutions are outlined and future radar observation opportunities for asteroids and comets are identified. For asteroids and comets that have only short intervals of optical astrometric data, the additional use of only a few radar observations allows a far more accurate extrapolation of their future motions. The use of radar data can often ensure an object's successful recovery at future Earth returns and greatly assist efforts in monitoring the motions of the rapidly growing population of known near-Earth objects, including their future close-Earth approaches. C1 HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. RP YEOMANS, DK (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 31 TC 38 Z9 43 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD JAN PY 1992 VL 103 IS 1 BP 303 EP 317 DI 10.1086/116062 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GX221 UT WOS:A1992GX22100027 ER PT J AU MASNOU, JL WILKES, BJ ELVIS, M MCDOWELL, JC ARNAUD, KA AF MASNOU, JL WILKES, BJ ELVIS, M MCDOWELL, JC ARNAUD, KA TI THE SOFT-X-RAY EXCESS IN EINSTEIN QUASAR SPECTRA SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE QUASARS; X-RAYS, SPECTROSCOPY; X-RAYS, GENERAL ID ACTIVE GALACTIC NUCLEI; SEYFERT-GALAXIES; BIG BUMP; CONTINUUM; EMISSION; CLUSTER AB We study the low-energy excess above a high-energy power law in the X-ray spectra for a signal-to-noise limited, subsample of 14 quasars from the Wilkes & Elvis (1987) sample. Detailed analysis of the Einstein imaging proportional counter (IPC) data, combined with monitor proportional counter (MPC) data where possible, and the use of accurate Galactic N(H) values allow us to estimate the flux of any detected excess and improve constraints on the spectral parameters at higher (> 0.6 keV) X-ray energies. We find a significant excess in 8 of the 14 objects, confined in all but one case to below 0.6 keV. The excess is typically strong, dominating the less-than-or-similar-to 0.3 keV X-ray flux and being 1-6 times as strong as the high-energy component at 0.2 keV. In 3C273, multiple observations show that the excess is variable. The lack of spectral information, uncertainty in the intrinsic line-of-sight absorption and the possibility of variation prevents the detection of any relation with the optical/ultraviolet blue bump. Comparison with an existing accretion disk model for the blue bump suggests that, for this model to explain both the blue bump and the soft X-ray excess, a range of disk parameters are required to explain the whole sample. C1 OBSERV PARIS, DARC, UPR 176, F-92195 MEUDON, FRANCE. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NR 45 TC 51 Z9 51 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JAN PY 1992 VL 253 IS 1 BP 35 EP 48 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GY754 UT WOS:A1992GY75400008 ER PT J AU WENZEL, KP MARSDEN, RG PAGE, DE SMITH, EJ AF WENZEL, KP MARSDEN, RG PAGE, DE SMITH, EJ TI THE ULYSSES MISSION SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE INTERPLANETARY MEDIUM; SOLAR SYSTEM, GENERAL; SPACE VEHICLES; SUN (THE), GENERAL AB The Ulysses mission is unique in the history of the exploration of our solar system by spacecraft. the path followed by Ulysses will enable us, for the first time, to explore the heliosphere within a few astronomical units of the Sun over the full range of heliographic latitudes, thereby providing the first characterisation of the uncharted third heliospheric dimension. Advanced scientific instrumentation carried on board the spacecraft is designed to measure the properties of the heliospheric magnetic field, the solar wind, the Sun/wind interface, solar radio bursts and plasma waves, solar energetic particles and galactic cosmic rays, solar X-rays, and interplanetary/interstellar neutral gas and dust. Ulysses will also be used to detect cosmic gamma-ray bursts and search for gravitational waves. The mission, a collaboration between ESA and NASA, was launched in October 1990 and employs a Jupiter gravity-assist to achieve the trajectory extending to high solar latitudes. Ulysses will spend a total of 234 days, equivalent to about 8 solar rotations, at latitudes in excess of 70-degrees. The purpose of this paper is to describe the characteristics of the Ulysses mission in order to establish a framework within which to better understand the objectives and goals of the scientific investigations which are described in subsequent papers. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP WENZEL, KP (reprint author), EUROPEAN SPACE TECHNOL CTR,EUROPEAN SPACY AGCY,DEPT SPACE SCI,POB 299,2200 AG NOORDWIJK,NETHERLANDS. NR 20 TC 116 Z9 120 U1 1 U2 4 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 207 EP 219 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700001 ER PT J AU BALOGH, A BEEK, TJ FORSYTH, RJ HEDGECOCK, PC MARQUEDANT, RJ SMITH, EJ SOUTHWOOD, DJ TSURUTANI, BT AF BALOGH, A BEEK, TJ FORSYTH, RJ HEDGECOCK, PC MARQUEDANT, RJ SMITH, EJ SOUTHWOOD, DJ TSURUTANI, BT TI THE MAGNETIC-FIELD INVESTIGATION ON THE ULYSSES MISSION - INSTRUMENTATION AND PRELIMINARY SCIENTIFIC RESULTS SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE INTERPLANETARY MEDIUM, MAGNETIC FIELD ID 1-AU AB A fundamental feature of the heliosphere is the three dimensional structure of the interplanetary magnetic field. The magnetic field investigation on Ulysses, the first space probe to explore the out-of-ecliptic and polar heliosphere, aims at determining the large scale features and gradients of the field, as well as the heliolatitude dependence of interplanetary phenomena so far only observed near the ecliptic plane. The Ulysses magnetometer uses two sensors, one a Vector Helium Magnetometer, the other a Fluxgate Magnetometer. Onboard data processing yields measurements of the magnetic field vector with a time resolution up to 2 vectors/second and a sensitivity of about 10 pT. Since the switch-on of the instrument in flight on 25 October 1990, a steady stream of observations have been made, indicating that at this phase of the solar cycle the field is generally disturbed: several shock waves and a large number of discontinuities have been observed, as well as several periods with apparently intense wave activity. The paper gives a brief summary of the scientific objectives of the investigation, followed by a detailed description of the instrument and its characteristics. Examples of wave bursts, interplanetary shocks and crossings of the heliospheric current sheet are given to illustrate the observations made with the instrument. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP BALOGH, A (reprint author), UNIV LONDON IMPERIAL COLL SCI & TECHNOL,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. NR 17 TC 349 Z9 349 U1 0 U2 5 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 221 EP 236 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700002 ER PT J AU BAME, SJ MCCOMAS, DJ BARRACLOUGH, BL PHILLIPS, JL SOFALY, KJ CHAVEZ, JC GOLDSTEIN, BE SAKURAI, RK AF BAME, SJ MCCOMAS, DJ BARRACLOUGH, BL PHILLIPS, JL SOFALY, KJ CHAVEZ, JC GOLDSTEIN, BE SAKURAI, RK TI THE ULYSSES SOLAR-WIND PLASMA-EXPERIMENT SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE SUN, SOLAR POLES; SOLAR WIND, LATITUDINAL VARIATION; INTERPLANETARY HELIOSPHERIC MEDIUM AB The Solar Wind Plasma Experiment on Ulysses is accurately characterizing the bulk flow and internal state conditions of the interplanetary plasma in three dimensions on the way out to Jupiter. These observations will continue over the full range of heliocentric distances and heliographic latitudes reached by the probe after its encounter with Jupiter and consequent deflection out of the ecliptic plane. Solar wind electrons and ions are measured simultaneously with independent curved-plate electrostatic analyzers equipped with multiple Channel Electron Multipliers (CEMs). The CEMs are arranged to detect particles at chosen polar angles from the spacecraft spin axis; resolution in spacecraft azimuth is obtained by timing measurements with the spacecraft Sun clock as the spacecraft spins. Electrons with central energies extending from 0.86 eV to 814 eV are detected at seven polar angles and various combinations of azimuth angle to cover the unit sphere comprehensively, so as to enable computation of the pertinent electron velocity distribution parameters. As the average electron flux level changes with heliocentric distance, command control of the CEM counting intervals is used to extend the dynamic range. Ions are detected between 255 eV/q and 34.4 keV/q using appropriate subsets of 16 CEMs at spin angles designed to provide matrices of counts as a function of energy per charge, azimuth angle, and polar angle centered on the average direction of solar-wind flow. Data matrices are obtained every 4 min when the spacecraft is actively transmitting and every 8 min during data store periods. These matrices contain sufficient energy and angle resolution to permit a detailed characterization of the ion velocity distributions, from which ion bulk parameters are derived. As the average ion flux intensity changes with heliocentric distance, the entrance aperture size is periodically optimized by command selection from a set of seven apertures on a disk driven by a stepping motor. Changes in the average solar wind flow direction relative to the Earth-pointing spacecraft spin axis are accommodated by command selection of the proper measurement matrix from a set of 11 matrices. In a separate mode of operation and under favorable conditions, heavy ions of oxygen, silicon, and iron at various charge levels are resolved. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP BAME, SJ (reprint author), UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87544, USA. NR 0 TC 377 Z9 377 U1 1 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 237 EP 265 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700003 ER PT J AU GLOECKLER, G GEISS, J BALSIGER, H BEDINI, P CAIN, JC FISCHER, J FISK, LA GALVIN, AB GLIEM, F HAMILTON, DC HOLLWEG, JV IPAVICH, FM JOOS, R LIVI, S LUNDGREN, R MALL, U MCKENZIE, JF OGILVIE, KW OTTENS, F RIECK, W TUMS, EO VONSTEIGER, R WEISS, W WILKEN, B AF GLOECKLER, G GEISS, J BALSIGER, H BEDINI, P CAIN, JC FISCHER, J FISK, LA GALVIN, AB GLIEM, F HAMILTON, DC HOLLWEG, JV IPAVICH, FM JOOS, R LIVI, S LUNDGREN, R MALL, U MCKENZIE, JF OGILVIE, KW OTTENS, F RIECK, W TUMS, EO VONSTEIGER, R WEISS, W WILKEN, B TI THE SOLAR-WIND ION COMPOSITION SPECTROMETER SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE INTERPLANETARY MEDIUM; JUPITER; ARTIFICIAL SATELLITES SPACE PROBES; SUN, SOLAR WIND ID EARTHS BOW SHOCK; VOYAGER-2; UPSTREAM; PLASMA; ORIGIN AB The Solar Wind Ion Composition Spectrometer (SWICS) on Ulysses is designed to determine uniquely the elemental and ionic-charge composition, and the temperatures and mean speeds of all major solar-wind ions, from H through Fe, at solar wind speeds ranging from 175 km/s (protons) to 1280 km/s (Fe8+). The instrument, which covers an energy per charge range from 0.16 to 59.6 keV/e in approximately 13 min, combines an electrostatic analyzer with post-acceleration, followed by a time-of-flight and energy measurement. The measurements made by SWICS will have an impact on many areas of solar and heliospheric physics, in particular providing essential and unique information on: (i) conditions and processes in the region of the corona where the solar wind is accelerated; (ii) the location of the source regions of the solar wind in the corona; (iii) coronal heating processes; (iv) the extent and causes of variations in the composition of the solar atmosphere; (v) plasma processes in the solar wind; (vi) the acceleration of energetic particles in the solar wind; (vii) the thermalization and acceleration of interstellar ions in the solar wind, and their composition; and (viii) the composition, charge states and behavior of the plasma in various regions of the Jovian magnetosphere. C1 UNIV BERN,INST PHYS,CH-3000 BERN,SWITZERLAND. UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. TECH UNIV BRAUNSCHWEIG,INST DATENVERARBEITENDE ANLAGEN,W-3300 BRAUNSCHWEIG,GERMANY. UNIV NEW HAMPSHIRE,DEPT PHYS,DURHAM,NH 03824. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NASA,OFF SPACE SCI & APPLICAT,WASHINGTON,DC 20546. MAX PLANCK INST AERON,W-3411 KATLENBURG DUHM,GERMANY. RP GLOECKLER, G (reprint author), UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742, USA. RI Von Steiger, Rudolf/F-6822-2011; Galvin, Antoinette/A-6114-2013 OI Von Steiger, Rudolf/0000-0002-3350-0023; NR 23 TC 258 Z9 258 U1 0 U2 6 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 267 EP 289 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700004 ER PT J AU STONE, RG BOUGERET, JL CALDWELL, J CANU, P DECONCHY, Y CORNILLEAUWEHRLIN, N DESCH, MD FAINBERG, J GOETZ, K GOLDSTEIN, ML HARVEY, CC HOANG, S HOWARD, R KAISER, ML KELLOGG, PJ KLEIN, B KNOLL, R LECACHEUX, A LENGYELFREY, D MACDOWALL, RJ MANNING, R MEETRE, CA MEYER, A MONGE, N MONSON, S NICOL, G REINER, MJ STEINBERG, JL TORRES, E DEVILLEDARY, C WOUTERS, F ZARKA, P AF STONE, RG BOUGERET, JL CALDWELL, J CANU, P DECONCHY, Y CORNILLEAUWEHRLIN, N DESCH, MD FAINBERG, J GOETZ, K GOLDSTEIN, ML HARVEY, CC HOANG, S HOWARD, R KAISER, ML KELLOGG, PJ KLEIN, B KNOLL, R LECACHEUX, A LENGYELFREY, D MACDOWALL, RJ MANNING, R MEETRE, CA MEYER, A MONGE, N MONSON, S NICOL, G REINER, MJ STEINBERG, JL TORRES, E DEVILLEDARY, C WOUTERS, F ZARKA, P TI THE UNIFIED RADIO AND PLASMA-WAVE INVESTIGATION SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE SPACE VEHICLES; RADIO EMISSIONS FROM THE SUN; SOLAR WIND; INTERPLANETARY MEDIUM; MAGNETOSPHERE OF JUPITER; PLASMAS ID SOLAR-WIND SPEED; THERMAL NOISE; ELECTRONS; BURSTS; TORUS; VOYAGER-1; EMISSION; JUPITER; ISEE-3; SHOCK AB The scientific objectives of the Ulysses Unifiewd Radio and Plasma wave (URAP) experiment are twofold: 1) the determination of the direction, angular size, and polarization of radio sources for remote sensing of the heliosphere and the Jovian magnetosphere and 2) the detailed study of local wave phenomena, which determine the transport coefficients of the ambient plasma. The tracking of solar radio bursts, for example, can provide three dimensional "snapshots" of the large scale magnetic field configuration along which the solar exciter particles propagate. URAP observations of Jovian radio emissions should greatly improve the determination of source locations and consequently our understanding of the generation mechanism(s) of planetary radio emissions. The study of observed wave-particle interactions will improve our understanding of the processes that occur in the solar wind and at Jupiter and of radio wave generation. A brief discussion of the scientific goals of the experiment is followed by a comprehensive description of the instrument. The URAP sensors consist of a 72.5 m electric field antenna in the spin plane, a 7.5-m electric field monopole along the spin axis and a pair of orthogonal search coil magnetic antennas. The various receivers, designed to encompass specific needs of the investigation, cover the frequency range from DC to 1 MHz. A relaxation sounder provides very accurate electron density measurements. Radio and plasma wave observations are shown to demonstrate the capabilities and limitations of the URAP instruments: radio observations include solar bursts, auroral kilometric radiation, and Jovian bursts; plasma waves include Langmuir waves, ion acoustic-like noise, and whistlers. C1 OBSERV PARIS,F-92190 MEUDON,FRANCE. CTR NATL ETUD TELECOMMUN,CNRS,CTR RECH PHYS ENVIRONM TERRESTRE & PLANETAIRE,F-92131 ISSY MOULINEAUX,FRANCE. UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN 55455. RP STONE, RG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. RI MacDowall, Robert/D-2773-2012; Goldstein, Melvyn/B-1724-2008 NR 41 TC 192 Z9 192 U1 0 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 291 EP 316 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700005 ER PT J AU SIMPSON, JA ANGLIN, JD BALOGH, A BERCOVITCH, M BOUMAN, JM BUDZINSKI, EE BURROWS, JR CARVELL, R CONNELL, JJ DUCROS, R FERRANDO, P FIRTH, J GARCIAMUNOZ, M HENRION, J HYNDS, RJ IWERS, B JACQUET, R KUNOW, H LENTZ, G MARSDEN, RG MCKIBBEN, RB MUELLERMELLIN, R PAGE, DE PERKINS, M RAVIART, A SANDERSON, TR SIERKS, H TREGUER, L TUZZOLINO, AJ WENZEL, KP WIBBERENZ, G AF SIMPSON, JA ANGLIN, JD BALOGH, A BERCOVITCH, M BOUMAN, JM BUDZINSKI, EE BURROWS, JR CARVELL, R CONNELL, JJ DUCROS, R FERRANDO, P FIRTH, J GARCIAMUNOZ, M HENRION, J HYNDS, RJ IWERS, B JACQUET, R KUNOW, H LENTZ, G MARSDEN, RG MCKIBBEN, RB MUELLERMELLIN, R PAGE, DE PERKINS, M RAVIART, A SANDERSON, TR SIERKS, H TREGUER, L TUZZOLINO, AJ WENZEL, KP WIBBERENZ, G TI THE ULYSSES COSMIC-RAY AND SOLAR PARTICLE INVESTIGATION SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE COSMIC RAYS; SOLAR PARTICLES; HELIOSPHERE ID JOVIAN ELECTRONS AB The Ulysses spacecraft, launched on 6 October 1990, is the first to undertake measurements in the heliosphere far from the ecliptic plane and over the polar regions of the Sun. The instrumentation carried by the spacecraft includes a group of six charged particle telescopes to measure the energy, composition, intensity and anisotropy of nucleons in the energy range from approximately 0.5 MeV/nucleon to approximately 600 MeV/nucleon for elements in the range H to Ni. Isotopic abundances for nuclei H to Ni are obtained over a more limited energy range. Electron measurements extend from 2.5 to 6000 MeV. One set of telescopes will measure the three-dimensional anisotropies of protons and helium at low energies. A special high flux telescope provides measurements of protons and heavier particles approximately 0.2 to approximately 36 MeV with high azimuthal resolution. These instruments were prepared by an international consortium to address a wide range of scientific objectives made possible by a mission to investigate the Sun and the heliosphere in three dimensions. Our program is called "Cosmic Ray and Solar Particle Investigation" or COSPIN. Examples of the COSPIN scientific goals include: (i) For energetic charged particles of solar origin, to determine the role of coronal magnetic fields in their acceleration and propagation and to search for the origin of the enrichment of He-3 and Fe nuclei observed in some solar particle events; (ii) Using galactic cosmic radiation measurements, to explore the likely reduction or elimination of solar modulation in polar regions relative to the equator, to search for the origin of the anomalous nuclear component, and to determine the nucleosynthetic origins of nuclei at lowest measurable energies; (iii) For energetic nuclei and electrons of interplanetary origin, to study the three-dimensional character of traveling shocks, CIRs and their associated charged particle acceleration, and; (iv) As a secondary scientific objective at Jupiter encounter (closest approach 8 Feb., 1992), to characterize the energetic charged particle populations during the first traversal of the dusk side of the Jovian magnetosphere and to search for the mechanism producing the approximately 10 hour "clock" variation of Jovian electrons in the interplanetary medium. In this publication we give a detailed description of the instruments, their pre-launch performance and a sampling of preliminary results based on the data so far available, extending from turn-on on day 296, 1990 through the early days of 1991. During this period a solar flare provided nuclei in the energy range approximately 0.5 to 200 MeV/nucleon which made possible the first intercalibration of the instruments over a flux range approximately 10(7). Observations of six solar flare energetic charged particle events are shown for nuclei. Three of these events also accelerated electrons. An observation of a He-3-rich solar particle event and the measured anisotropy of protons from a flare is reported. From observations of heavy ions in the data so far available, the effectiveness of employing position-sensing semi-conductor detectors for obtaining enhanced elemental and isotopic resolution is demonstrated, even at this early stage of analysis. These preliminary results confirm that the instruments are functioning properly, and that their design has achieved both the wide dynamic range required to encompass the unexpected phenomena likely to be encountered on this exploratory and discovery mission, and the precision required to make definitive measurements on this, the only mission presently planned to explore the high latitude regions of the heliosphere. C1 EUROPEAN SPACE TECHNOL CTR,EUROPEAN SPACE AGCY,DEPT SPACE SCI,2200 AG NOORDWIJK,NETHERLANDS. NATL RES COUNCIL CANADA,HERZBERG INST ASTROPHYS,OTTAWA K1A 0R6,ONTARIO,CANADA. UNIV KIEL,INST REINE & ANGEW KERNPHYS,W-2300 KIEL 1,GERMANY. CALTECH,JET PROP LAB,EUROPEAN SPACE AGCY,PASADENA,CA 91109. UNIV LONDON IMPERIAL COLL SCI & TECHNOL,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. CENS,SERV ASTROPHYS,F-91191 GIF SUR YVETTE,FRANCE. UNIV OXFORD,CLARENDON LAB,OXFORD,ENGLAND. RP SIMPSON, JA (reprint author), UNIV CHICAGO,ASTROPHYS & SPACE RES LAB,CHICAGO,IL 60637, USA. NR 11 TC 197 Z9 197 U1 1 U2 4 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 365 EP 399 PG 35 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700009 ER PT J AU HURLEY, K SOMMER, M ATTEIA, JL BOER, M CLINE, T COTIN, F HENOUX, JC KANE, S LOWES, P NIEL, M VANROOIJEN, J VEDRENNE, G AF HURLEY, K SOMMER, M ATTEIA, JL BOER, M CLINE, T COTIN, F HENOUX, JC KANE, S LOWES, P NIEL, M VANROOIJEN, J VEDRENNE, G TI THE SOLAR-X-RAY COSMIC GAMMA-RAY BURST EXPERIMENT ABOARD ULYSSES SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE GAMMA-RAYS, BURSTS, SUN, X-RAYS, INSTRUMENTS ID FLARES; DIRECTIVITY AB We describe the scientific objectives of the Ulysses solar X-ray/cosmic gamma-ray burst experiment, and the unique features of the Ulysses mission which will help to achieve them. After a discussion of the special design constraints imposed by the mission, we describe the sensor systems, consisting of two CsI scintillators and two Si surface barrier detectors covering the energy range 5 keV-150 keV. Their operating modes and inflight performance are also given. C1 MAX PLANCK INST EXTRATERRESTR PHYS, W-8046 GARCHING, GERMANY. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. CTR ETUD SPATIALE RAYONNEMENTS, F-31029 TOULOUSE, FRANCE. SRON, LAB SPACE RES UTRECHT, 3584 CA UTRECHT, NETHERLANDS. OBSERV MEUDON, DASOP, F-92195 MEUDON, FRANCE. RP HURLEY, K (reprint author), UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. NR 17 TC 69 Z9 69 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 401 EP 410 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700010 ER PT J AU GRUN, E FECHTIG, H GIESE, RH KISSEL, J LINKERT, D MAAS, D MCDONNELL, JAM MORFILL, GE SCHWEHM, G ZOOK, HA AF GRUN, E FECHTIG, H GIESE, RH KISSEL, J LINKERT, D MAAS, D MCDONNELL, JAM MORFILL, GE SCHWEHM, G ZOOK, HA TI THE ULYSSES DUST EXPERIMENT SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE ARTIFICIAL SATELLITES, SPACE PROBES; INSTRUMENTATION INTERPLANETARY MEDIUM ID INTER-PLANETARY; SOLAR-SYSTEM; PARTICLES; INTERPLANETARY AB The Ulysses dust experiment is intended to provide direct observations of dust grains with masses between 10(-16) g and 10(-6) g in interplanetary space, to investigate their physical and dynamical properties as functions of heliocentric distance and ecliptic latitude. Of special interest is the question of what portion is provided by comets, asteroids and interstellar particles. The investigation is performed with an instrument that measures the mass, speed, flight direction and electric charge of individual dust particles. It is a multicoincidence detector with a mass sensitivity 10(6) times higher than that of previous in-situ experiments which measured dust in the outer solar system. The instrument weighs 3.8 kg, consumes 2.2 W, and has a normal data transmission rate of 8 bits/s in nominal spacecraft tracking mode. On 27th October 1990 the instrument was switched-on. The instrument was configured to flight conditions and science data collection started immediately. In the period to 13th January 1991 at least 44 dust impacts have been recorded. Flux values are given covering the heliocentric distance range from 1.04 to 1.7 AU. C1 RUHR UNIV BOCHUM,W-4630 BOCHUM,GERMANY. KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH,W-7500 KARLSRUHE 1,GERMANY. UNIV KENT,CANTERBURY CT2 7NZ,KENT,ENGLAND. EUROPEAN SPACE TECHNOL CTR,EUROPEAN SPACE AGCY,NOORDWIJK,NETHERLANDS. MAX PLANCK INST EXTRATERRESTR PHYS,GARCHING,GERMANY. NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. RP GRUN, E (reprint author), MAX PLANCK INST NUCL PHYS,W-6900 HEIDELBERG 1,GERMANY. NR 44 TC 113 Z9 113 U1 0 U2 5 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 411 EP 423 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700011 ER PT J AU BIRD, MK ASMAR, SW BRENKLE, JP EDENHOFER, P PATZOLD, M VOLLAND, H AF BIRD, MK ASMAR, SW BRENKLE, JP EDENHOFER, P PATZOLD, M VOLLAND, H TI THE CORONAL-SOUNDING EXPERIMENT SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE INTERPLANETARY MEDIUM, SOLAR CORONA ID SOLAR-WIND; ELECTRON-DENSITIES; TORUS; IO AB The main science objective of the Ulysses Solar Corona Experiment is to derive the plasma parameters of the solar atmosphere using established coronal-sounding techniques. Applying appropriate model assumptions, the 3-D electron density distribution will be determined from dual-frequency ranging and Doppler measurements recorded at the NASA Deep Space Network during the solar conjunctions. Multi-station observations will be used to derive the plasma bulk velocity at solar distances where the solar wind is expected to undergo its greatest acceleration. As a secondary objective profiting from the favorable geometry during Jupiter encounter, radio-sounding measurements will yield a unique cross-scan of the electron density in the Io Plasma Torus. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RUHR UNIV BOCHUM,INST HOCHFREQUENZTECH,W-4630 BOCHUM,GERMANY. DLR OBERPFAFFENHOFEN,INST HOCHFREQUENZTECH,W-8031 WESSELING,GERMANY. RP BIRD, MK (reprint author), UNIV BONN,INST RADIOASTRON,HUGEL 71,W-5300 BONN,GERMANY. NR 17 TC 13 Z9 13 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 425 EP 430 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700012 ER PT J AU BERTOTTI, B AMBROSINI, R ASMAR, SW BRENKLE, JP COMORETTO, G GIAMPIERI, G IESS, L MESSERI, A WAHLQUIST, HD AF BERTOTTI, B AMBROSINI, R ASMAR, SW BRENKLE, JP COMORETTO, G GIAMPIERI, G IESS, L MESSERI, A WAHLQUIST, HD TI THE GRAVITATIONAL-WAVE EXPERIMENT SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE GRAVITATIONAL WAVES; SOLAR WIND; DOPPLER MEASUREMENTS ID SPACECRAFT; RADIATION; TRACKING AB Since the optimum size of a gravitational wave detector is the wave length, interplanetary dimensions are needed for the mHz band of interest. Doppler tracking of Ulysses will provide the most sensitive attempt to date at the detection of gravitational waves in the low frequency band. The driving noise source is the fluctuations in the refractive index of interplanetary plasma. This dictates the timing of the experiment to be near solar opposition and sets the target accuracy for the fractional frequency change at 3.0 x 10(-14) for integration times of the order of 1000 sec. The instrumentation utilized by the experiment is distributed between the radio systems on the spacecraft and the seven participating ground stations of the Deep Space Network and Medicina. Preliminary analysis is available of the measurements taken during the Ulysses first opposition test. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV PAVIA,DIPARTIMENTO FIS NUCL & TEOR,I-27100 PAVIA,ITALY. IST RADIOSTRON,BOLOGNA,ITALY. OSSERV ASTROFOS ARCETRI,FLORENCE,ITALY. IST FIS SPAZIO INTERPLANETARIO,FRASCATI,ITALY. RI Comoretto, Giovanni/F-6854-2010; IESS, Luciano/F-4902-2011 OI IESS, Luciano/0000-0002-6230-5825 NR 13 TC 12 Z9 12 U1 0 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD JAN PY 1992 VL 92 IS 2 BP 431 EP 440 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HA437 UT WOS:A1992HA43700013 ER PT S AU WARD, WR AF WARD, WR BE Dermott, SF Hunter, JH Wilson, RE TI DISK PROTOPLANET INTERACTIONS - TORQUES FROM THE COORBITAL ZONE SO ASTROPHYSICAL DISKS SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Proceedings Paper CT 7TH FLORIDA WORKSHOP ON NONLINEAR ASTRONOMY CY SEP 26-28, 1991 CL UNIV FLORIDA, REITZ UNION BLDG, GAINESVILLE, FL SP NEW YORK ACAD SCI, UNIV FLORIDA, COLL LIBERAL ARTS & SCI, UNIV FLORIDA, DIV SPONSORED RES HO UNIV FLORIDA, REITZ UNION BLDG RP WARD, WR (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU NEW YORK ACAD SCIENCES PI NEW YORK PA NEW YORK SN 0077-8923 BN 0-89766-740-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1992 VL 675 BP 314 EP 323 DI 10.1111/j.1749-6632.1992.tb56814.x PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX86R UT WOS:A1992BX86R00031 ER PT J AU DOLAN, JF AF DOLAN, JF TI A REANALYSIS OF THE ORBITAL INCLINATION OF CYGNUS XR-1 DETERMINED POLARIMETRICALLY SO ASTROPHYSICAL JOURNAL LA English DT Article DE BLACK HOLE PHYSICS; POLARIZATION; STARS, INDIVIDUAL (CYGNUS-XR-1); X-RAYS, STARS ID X-RAY BINARIES; NEUTRON-STARS; MAXIMUM MASS; BLACK-HOLE; POLARIZATION; SCATTERING AB The orbital inclincation of the Cyg XR-1/HDE 226868 system was determined in 1989 by Dolan and Tapia to be 62-degrees (+ 5-degrees, -37-degrees) from polarimetric observations. Together with the spectroscopic mass function of the binary, this corresponds to a mass of 6.3 M. for the X-ray source. The observations were not corrected for any component of the polarization caused by tidal deformation of the primary. Numerical simulations show that there is no straightforward way of removing tidal deformation polarization (TDP) from polarimetric observations of close binaries. A reanalysis of the data shows that the existence of TDP in the Stokes parameter light curves observed from Cyg XR-1 does not significantly bias the mass derived to larger values. The mass of Cyg XR-1 must be significantly larger than 5 M.. This fact alone does not require Cyg XR-1 to be a black hole, however. Recent theoretical investigations of possible equations of state of matter at nuclear density show that the maximum mass of a compact object which is not a black hole may be much greater than 5 M.. C1 STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. STANFORD UNIV,CTR SPACE SCI & ASTROPHYS,STANFORD,CA 94305. RP DOLAN, JF (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. NR 31 TC 35 Z9 35 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 1992 VL 384 IS 1 BP 249 EP 254 DI 10.1086/170867 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GW612 UT WOS:A1992GW61200023 ER PT J AU WULSER, JP ZARRO, DM CANFIELD, RC AF WULSER, JP ZARRO, DM CANFIELD, RC TI ENERGETICS AND DYNAMICS IN A LARGE SOLAR-FLARE OF 1989 MARCH SO ASTROPHYSICAL JOURNAL LA English DT Article DE LINE, PROFILES; SUN, CHROMOSPHERE; SUN, CORONA; SUN, FLARES; SUN, X-RAYS, GAMMA-RAYS ID X-RAY BURSTS; ELECTRONS; TEMPERATURE; EMISSION AB For the first time in a large (X1.2) solar flare, we have combined Solar Maximum Mission X-ray observations and National Solar Observatory/Sacramento Peak H-alpha spectra to test predictions of chromospheric heating and evaporation by nonthermal thick-target electrons. We demonstrate that the ratio of H-alpha flare energy flux to the energy flux deposited by thick-target electrons obeys a power-law dependence on electron heating flux, with a slope that is consistent with that predicted by a thick-target electron transport and heating model in a one-dimensional hydrostatic atmosphere. Comparison of the observed H-alpha emission with that predicted by the thick-target model implies a constant electron precipitation area of A(p) = (2.2 +/- 0.7) x 10(17) cm2 during the impulsive phase. The electron precipitation area deduced for this X-flare is consistent with the mean value of approximately 10(17) cm2 obtained from a similar thick-target analysis of H-alpha and extreme ultraviolet observations in weaker solar flares. The constancy of the precipitation area between flares ranging orders of magnitude in X-ray intensity reinforces the concept of a universally invariant kernel area for impulsive flare bursts. We find that upflowing coronal material (as seen in blueshifted Ca XIX soft X-rays) and downflowing chromospheric material (as seen in redshifted H-alpha) appear simultaneously at the beginning of impulsive hard X-ray emission, with the total momenta of oppositely directed plasmas being equal to within the observational uncertainties. The observed momentum balance is consistent with the chromospheric evaporation interpretation for soft X-ray blueshifts and H-alpha redshifts. For a low-energy cutoff in the electron energy distribution of between 15 and 20 keV, the initial energy content of thick-target electrons is sufficient to drive the observed initial chromospheric downflow velocity of upsilon-d approximately 50 km s-1. We conclude that the thick-target model satisfactorily accounts for the observed magnitude of chromospheric H-alpha emission, and the timing and amplitudes of oppositely directed plasma motions during the impulsive phase of this X flare, as well as the other weaker flares which we have studied earlier. C1 NASA,GODDARD SPACE FLIGHT CTR,APPL RES CORP,LANDOVER,MD 20785. LOCKHEED PALO ALTO RES LABS,PALO ALTO,CA 94304. RP WULSER, JP (reprint author), UNIV HAWAII,INST ASTRON,2680 WOODLAWN DR,HONOLULU,HI 96822, USA. NR 29 TC 17 Z9 17 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 1992 VL 384 IS 1 BP 341 EP 347 DI 10.1086/170877 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GW612 UT WOS:A1992GW61200033 ER PT J AU HOYT, DV SCHATTEN, KH AF HOYT, DV SCHATTEN, KH TI NEW INFORMATION ON SOLAR-ACTIVITY, 1779-1818, FROM HERSCHEL,WILLIAM UNPUBLISHED NOTEBOOKS SO ASTROPHYSICAL JOURNAL LA English DT Article DE SUN, ACTIVITY; SUNSPOTS ID CLIMATE; SUN AB Sir William Herschel observed the Sun from 1779 to 1818 with most of these solar observations made from 1799 to 1806. Wolf in reconstructing the long-term history of solar activity did not have Herschel's notebooks for analysis and thus was limited to scattered observations for the period 1801-1807. According to Wolf, the Wolf sunspot numbers for these years are very uncertain. Thus, by analyzing Herschel's notebooks, a better reconstruction of solar activity during cycle 5 is feasible. From Herschel's observations we find that the peak sunspot number occurred in 1801-1803 time period rather than 1805 as Wolf deduced. Instead of a solar cycle of 17 yr in length, we find a cycle length of 14 yr. Second, we find that the peak yearly mean sunspot number is only about 38 rather than 45 as Wolf deduced. Thus, this solar cycle was the weakest cycle since the Maunder Minimum and has been called the Dalton or Modern Minimum. Be-10, C-14, aurora records, and magnetic declination observations all tend to support these conclusions. In the course of this study, a technique for making early solar observations homogeneous with modern sunspot observations is developed and discussed. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP HOYT, DV (reprint author), RES & DATA SYST CORP,GREENBELT,MD 20770, USA. NR 25 TC 14 Z9 14 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 1992 VL 384 IS 1 BP 361 EP & DI 10.1086/170879 PN 1 PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GW612 UT WOS:A1992GW61200035 ER PT J AU GRIGSBY, JA MORRISON, ND ANDERSON, LS AF GRIGSBY, JA MORRISON, ND ANDERSON, LS TI NON-LTE, LINE-BLANKETED MODEL ATMOSPHERES FOR LATE O-TYPE AND EARLY B-TYPE STARS SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE RADIATIVE; STARS, ABUNDANCES; STARS, ATMOSPHERES; STARS, EARLY-TYPE ID LOCAL THERMODYNAMIC-EQUILIBRIUM; HOT STARS; EFFECTIVE TEMPERATURES; STELLAR ATMOSPHERE; HE-I; CARBON; PROFILES; PHOTOSPHERES; STRENGTHS; HYDROGEN AB This paper reports the first use of non-LTE, line-blanketed model atmospheres to analyze the spectra of hot stars. The stars analyzed are members of clusters and associations, have spectral types in the range O9-B2 and luminosity classes in the range III-V, have slow to moderate rotation, and are photometrically constant. The model-atmosphere code, PAM, has been described by Anderson in 1985 and 1987. In the present study, sampled line opacities of iron-group elements were incorporated into the radiative transfer solution. Solar abundances were assumed. Synthetic line profiles of H-alpha, H-beta, H-gamma, and He I lambda-lambda-4471 and 4922 were fitted to the stellar spectra in order to choose T(eff), log g, and v sin i for each star. In most of the program stars, we obtained good to excellent agreement between the computed profiles and essentially all the line profiles used to fix the model, and we derived reliable stellar parameters. With other lines, however, the models demonstrate less success in reproducing observed line strengths, probably due to inadequate model ions for He II, N II, and C II. The synthetic Mg II lambda-4481 equivalent widths agree well with the observed ones at the low end of the temperature range studied, but, above 25,000 K, the synthetic line is generally stronger than the observed line. In H-alpha, the fit to the inner line wings is improved over what was achieved in previous studies, but the present study finds that the synthetic line cores are systematically too deep. The cause of this discrepancy is unknown. For most stars in common with previous studies, there are no disagreements in the derived stellar parameters that can be attributed to the physics included in the model atmosphere. In 10 Lacertae, a disagreement with the effective temperature of Schonberner et al. can be attributed to the choice of lines to which the model was fitted. The sample of stars includes delta-Scorpii, for which the angular diameter has been measured. In common with other model-atmosphere investigations, we find an effective temperature slightly lower than that implied by the angular diameter. We did not use the models to compute color indices, but we constructed the relation between the observed Stromgren c0 index and our derived values of T(eff). The result is a useful temperature calibration for c0. The behavior of the observed equivalent widths of N ii, N III, C II, and C III lines as a function of T(eff) was studied. Most of the lines show much scatter, with no consistent trend that could indicate abundance differences from star to star. Even the claimed N star, HD 12323, does not show a consistent enhancement in the strengths of the N lines, although the data do support a C deficiency in this star. The predicted behavior of He I lambda-5876 does not conform to its observed behavior, which can therefore be presumed to be dominated either by abundance differences from star to star or by some physical process that is not included in the model atmosphere. The predicted behavior of He II lambda-4686 is qualitatively as observed, but the observations show a great deal of scatter at a given T(eff). Since the line is strongly temperature sensitive, however, most of the scatter may be due to temperature errors. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV TOLEDO,RITTER ASTROPHYS RES CTR,TOLEDO,OH 43606. UNIV TOLEDO,DEPT PHYS & ASTRON,TOLEDO,OH 43606. NR 77 TC 39 Z9 39 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JAN PY 1992 VL 78 IS 1 BP 205 EP 237 DI 10.1086/191625 PG 33 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GZ639 UT WOS:A1992GZ63900006 ER PT J AU HOYT, DV SCHATTEN, KH AF HOYT, DV SCHATTEN, KH TI HERSCHEL,WILLIAM NOTEBOOKS - ABSTRACTS OF SOLAR OBSERVATIONS SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE SUN, ACTIVITY; SUNSPOTS ID FACULAE; MODEL AB Sir William Herschel observed the Sun from 1779 to 1818 with most of his observations made between 1799 and 1806. These observations are interesting both because other solar observers at this time were not very active and because solar behavior was quite unusual. Solar activity was nearly dormant and sunspot periods were very long. In this paper we provide an introduction to the background of Herschel's notebooks and the historical context within which his observations were made. The observations have relevance in reconstructing solar behavior, as discussed in a separate analysis paper by Hoyt and Schatten, and in understanding active features on the Sun such as faculae. The text of Herschel's notebooks with modem terms used throughout forms the body of this paper. The complete text has not previously been published and is not easily accessible to scholars. Herschel used different words for solar features than we now use, and thus, for clarity, we changed his terminology on two occasions. A glossary explains the terminology changed. In the text of the notebooks, several contemporaries are mentioned; we provide a brief description of Herschel's colleagues. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP HOYT, DV (reprint author), RES & DATA SYST CORP,GREENBELT,MD 20770, USA. NR 25 TC 6 Z9 7 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JAN PY 1992 VL 78 IS 1 BP 301 EP 340 DI 10.1086/191629 PG 40 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GZ639 UT WOS:A1992GZ63900010 ER PT J AU REYNARD, W AF REYNARD, W GP FLIGHT SAFETY FDN TI THE ANALYSIS AND DEIDENTIFICATION OF INFORMATION OBTAINED THROUGH PERFORMANCE MONITORING SO AVIATION SAFETY CHALLENGES IN THE 1990S SE INTERNATIONAL AIR SAFETY SEMINAR PROCEEDINGS LA English DT Proceedings Paper CT 44th International Air Safety Seminar - Aviation Safety Challenges in the 1990s CY NOV 11-14, 1991 CL SINGAPORE, SINGAPORE SP FLIGHT SAFETY FDN C1 NASA,AMES RES CTR,AVIAT SAFETY REPORTING SYST,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FLIGHT SAFETY FOUNDATION PI ALEXANDRIA PA 601 MADISON STREET STE 300, ALEXANDRIA, VA 22314 SN 0270-5176 J9 INT AIR SAF SEM P PY 1992 BP 70 EP 74 PG 5 WC Engineering, Aerospace; Engineering, Industrial; Ergonomics; Instruments & Instrumentation; Psychology SC Engineering; Instruments & Instrumentation; Psychology GA BC53E UT WOS:A1992BC53E00014 ER PT J AU ARNAUD, SB SHERRARD, DJ MALONEY, N WHALEN, RT FUNG, P AF ARNAUD, SB SHERRARD, DJ MALONEY, N WHALEN, RT FUNG, P TI EFFECTS OF 1-WEEK HEAD-DOWN TILT BED REST ON BONE-FORMATION AND THE CALCIUM ENDOCRINE SYSTEM SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article ID RENAL-FAILURE; PHOSPHATE; ALUMINUM; DISEASE AB To understand the potential early responses of human bone and the calcium endocrine system to spaceflight, we studied 8 healthy men, aged 35-44 years before, during, and after bed rest in a -6-degrees head-down tilt model for microgravity. Based on a novel single-dose labeling schedule, average rates of bone formation in the iliac crest were reduced in 6, unchanged in 1, and increased in 1 following the bed rest period. The decrease was greatest for subjects whose daily walking miles were highest (r = -0.762, p < 0.05, n = 7). Before a measurable increase in ionized serum calcium the sixth bed rest day, there was increased excretion of urinary calcium and sodium, evident the first 2 bed-rest days and parallel for the entire week (r = 0.92, p < 0.001). Reduced excretion of phosphorus and 3', 5' cyclic adenosine monophosphate on the first and second bed rest days was followed by an increase in serum phosphorus by the sixth bed rest day. Depressed serum concentrations of parathyroid hormone and 1,25-dihydroxyvitamin D were manifest by the sixth and seventh bed rest days. The similarity of the response of bone and the calcium endocrine system of healthy men after only 7 days to results of longer term bed rest studies emphasizes the responsiveness of the adult human skeleton to biomechanical stimuli induced by changes in activity and/or position. C1 UNIV WASHINGTON,SEATTLE,WA 98195. VET ADM MED CTR,SEATTLE,WA 98108. RP ARNAUD, SB (reprint author), NASA,AMES RES CTR,DIV LIFE SCI,SL239-11,MOFFETT FIELD,CA 94035, USA. NR 29 TC 70 Z9 71 U1 0 U2 2 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JAN PY 1992 VL 63 IS 1 BP 14 EP 20 PG 7 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA GY245 UT WOS:A1992GY24500003 PM 1550528 ER PT J AU NORFLEET, WT DEGIOANNI, JJ CALKINS, DS RESCHKE, MF BUNGO, MW KUTYNA, FA HOMICK, JL AF NORFLEET, WT DEGIOANNI, JJ CALKINS, DS RESCHKE, MF BUNGO, MW KUTYNA, FA HOMICK, JL TI TREATMENT OF MOTION SICKNESS IN PARABOLIC FLIGHT WITH BUCCAL SCOPOLAMINE SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article ID NITROGLYCERIN AB Treatment of acute motion sickness induced by parabolic flight with a preparation of scopolamine placed in the buccal pouch was investigated. Twenty-one subjects flew aboard a KC-135 aircraft operated by the National Aeronautics and Space Administration (NASA) which performed parabolic maneuvers resulting in periods of O-g, 1-g, and 1.8-g. Each subject flew once with a tablet containing scopolamine and once with a placebo in a random order, crossover design. Signs and symptoms of motion sickness were systematically recorded during each parabola by an investigator who was blind to the content of the tablet. Compared with flights using placebo, flights with buccal scopolamine resulted in significantly lower scores for nausea (31%-35% reduction) and vomiting (50% reduction in number of parabolas with vomiting). Side effects of the drug during flight were negligible. We conclude that buccal scopolamine is more effective than a placebo in treating ongoing motion sickness. C1 KRUG LIFE SCI,HOUSTON,TX. VIRGINIA MASON HOSP,DEPT ANESTHESIOL,SEATTLE,WA 98101. RP NORFLEET, WT (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,CODE SD51,HOUSTON,TX 77058, USA. NR 12 TC 15 Z9 15 U1 1 U2 3 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JAN PY 1992 VL 63 IS 1 BP 46 EP 51 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA GY245 UT WOS:A1992GY24500008 PM 1550533 ER PT J AU RAMON, C POWELL, MR AF RAMON, C POWELL, MR TI MODIFICATION OF CARDIAC CONTRACTION RATE BY PULSED MAGNETIC-FIELDS SO BIOELECTROMAGNETICS LA English DT Article DE ELF MAGNETIC FIELD; ECG; CARDIAC TISSUE; BEAT FREQUENCY ID HEART; MODEL AB Isolated rat hearts and excised canine cardiac tissues were subjected to pulsed magnetic fields. The fields excited in coils by tandem pairings of sinusoidal pulses were presented at various inter-pair delays and repetition rates. The waveform of the magnetic field was a single or multiple sinusoid followed after a variable delay by another single or multiple sinusoid. Small but reliable increases in the beating rate of rat heart were observed. Similar increases occurred in contraction rates of canine tissues. Both preparations exhibited a contraction-rate dependency on the repetition rate of the paired magnetic pulses: 4.5-6 rep/s for canine tissue, and 20-25 and 40-55 reps/s for rat heart. Flux-density thresholds for both preparations approximated 10 mT (100 gauss) rms. C1 UNIV WASHINGTON,CTR IMAGING SYST OPTIMIZAT,SEATTLE,WA 98195. NASA,LYNDON B JOHNSON SPACE CTR,SPACE BIOMED RES INST,HOUSTON,TX 77058. INST APPL PHYSIOL & MED,SEATTLE,WA 98122. RP RAMON, C (reprint author), UNIV WASHINGTON,CTR BIOENGN FT10,SEATTLE,WA 98195, USA. NR 17 TC 5 Z9 7 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0197-8462 J9 BIOELECTROMAGNETICS JI Bioelectromagnetics PY 1992 VL 13 IS 4 BP 303 EP 311 DI 10.1002/bem.2250130405 PG 9 WC Biology; Biophysics SC Life Sciences & Biomedicine - Other Topics; Biophysics GA JF337 UT WOS:A1992JF33700004 PM 1510738 ER PT J AU MATSON, PA GOWER, ST VOLKMANN, C BILLOW, C GRIER, CC AF MATSON, PA GOWER, ST VOLKMANN, C BILLOW, C GRIER, CC TI SOIL-NITROGEN CYCLING AND NITROUS-OXIDE FLUX IN A ROCKY-MOUNTAIN DOUGLAS-FIR FOREST - EFFECTS OF FERTILIZATION, IRRIGATION AND CARBON ADDITION SO BIOGEOCHEMISTRY LA English DT Article DE DOUGLAS-FIR FORESTS; FOREST FERTILIZATION; MICROBIAL IMMOBILIZATION; INSITU INCUBATIONS; N-15; NITROUS OXIDE; NITRIFICATION; NITROGEN MINERALIZATION ID NORTHEASTERN UNITED-STATES; PINE PLANTATION; TRANSFORMATIONS; COMBUSTION AB Nitrous oxide fluxes and soil nitrogen transformations were measured in experimentally-treated high elevation Douglas-fir forests in northwestern New Mexico, USA. On an annual basis, forests that were fertilized with 200 kg N/ha emitted an average of 0.66 kg/ha of N2O-N, with highest fluxes occurring in July and August when soils were both warm and wet. Control, irrigated, and woodchip treated plots were not different from each other, and annual average fluxes ranged from 0.03 to 0.23 kg/ha. Annual net nitrogen mineralization and nitrate production were estimated in soil and forest floor using in situ incubations; fertilized soil mineralized 277 kg ha-1 y-1 in contrast to 18 kg ha-1 y-1 in control plots. Relative recovery of (NH4)-N-15 applied to soil in laboratory incubations was principally in the form of NO3-N in the fertilized soils, while recovery was mostly in microbial biomass-N in the other treatments. Fertilization apparently added nitrogen that exceeded the heterotrophic microbial demand, resulting in higher rates of nitrate production and higher nitrous oxide fluxes. Despite the elevated nitrous oxide emission resulting from fertilization, we estimate that global inputs of nitrogen into forests are not currently contributing significantly to the increasing concentrations of nitrous oxide in the atmosphere. C1 UNIV WISCONSIN,DEPT FORESTRY,MADISON,WI 53706. UTAH STATE UNIV,DEPT FOREST RESOURCES,LOGAN,UT 84322. RP MATSON, PA (reprint author), NASA,AMES RES CTR,ECOSYST SCI & TECHNOL BRANCH,MOFFETT FIELD,CA 94035, USA. NR 39 TC 47 Z9 53 U1 1 U2 16 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PY 1992 VL 18 IS 2 BP 101 EP 117 DI 10.1007/BF00002705 PG 17 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA KT580 UT WOS:A1992KT58000003 ER PT J AU CASTRO, MS STEUDLER, PA MELILLO, JM ABER, JD MILLHAM, S AF CASTRO, MS STEUDLER, PA MELILLO, JM ABER, JD MILLHAM, S TI EXCHANGE OF N2O AND CH4 BETWEEN THE ATMOSPHERE AND SOILS IN SPRUCE-FIR FORESTS IN THE NORTHEASTERN UNITED-STATES SO BIOGEOCHEMISTRY LA English DT Article DE N2O; CH4; RED SPRUCE; BALSAM FIR; SPRUCE-FIR; FORESTS; NITROGEN; DEPOSITION; NITRIFICATION; MINERALIZATION; DENITRIFICATION ID NITROUS-OXIDE FLUXES; METHANE; EMISSIONS; ECOSYSTEM; MINERALIZATION; FERTILIZATION; DEPOSITION; FIELD; RATES AB We measured the exchange of N2O and CH4 between the atmosphere and soils in 5 spruce-fir stands located along a transect from New York to Maine. Nitrous oxide emissions averaged over the 1990 growing season (May-September) ranged from 2.1 ug N2O-N/m2-hr in New York to 0.4 ug N2O-N/m2-hr in Maine. The westernmost sites, Whiteface Mtn., New York and Mt. Mansfield, Vermont, had the highest nitrogen-deposition, net nitrification and N2O emissions. Soils at all sites were net sinks for atmospheric CH4. Methane uptake averaged over the 1990 growing season ranged from 0.02 mg CH4-C/m2-hr in Maine to 0.05 mg CH4-C/m2-hr in Vermont. Regional differences in CH4 uptake could not be explained by differences in nitrogen-deposition, soil nitrogen dynamics, soil moisture or soil temperature. We estimate that soils in spruce-fir forests at our study sites released ca. 0.02 to 0.08 kg N2O-N/ha and consumed ca. 0.74 to 1.85 kg CH4-C/ha in the 1990 growing season. C1 UNIV NEW HAMPSHIRE,INST STUDY EARTH OCEANS & SPACE,DURHAM,NH 03824. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP CASTRO, MS (reprint author), MARINE BIOL LAB,CTR ECOSYST,WOODS HOLE,MA 02543, USA. RI Castro, Mark/J-6529-2015 OI Castro, Mark/0000-0002-4279-8204 NR 35 TC 20 Z9 23 U1 0 U2 9 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PY 1992 VL 18 IS 3 BP 119 EP 135 DI 10.1007/BF00003273 PG 17 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA LC239 UT WOS:A1992LC23900001 ER PT S AU BONTING, SL AF BONTING, SL BE Mathewson, PR Finley, JW TI NEEDS FOR BIOSENSORS IN SPACE-BIOLOGY RESEARCH SO BIOSENSOR DESIGN AND APPLICATION SE ACS SYMPOSIUM SERIES LA English DT Review CT SYMP ON BIOSENSOR DESIGN AND APPLICATION, AT THE 201ST NATIONAL MEETING OF THE AMERICAN CHEMICAL SOC CY APR 14-19, 1991 CL ATLANTA, GA SP AMER CHEM SOC, DIV AGR & FOOD CHEM, AMER CHEM SOC, DIV AGROCHEM BIOCHEM TECHNOL, AMER CHEM SOC, DIV SMALL CHEM BUSINESS RP BONTING, SL (reprint author), NASA,AMES RES CTR,SETI INST,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA WASHINGTON SN 0097-6156 BN 0-8412-2494-3 J9 ACS SYM SER PY 1992 VL 511 BP 174 EP 183 PG 10 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Food Science & Technology; Toxicology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Food Science & Technology; Toxicology GA BX24H UT WOS:A1992BX24H00014 ER PT J AU BONTING, SL AF BONTING, SL TI UTILIZATION OF BIOSENSORS AND CHEMICAL SENSORS FOR SPACE APPLICATIONS SO BIOSENSORS & BIOELECTRONICS LA English DT Article ID FLOW-INJECTION ANALYSIS AB There will be a need for a wide array of chemical sensors for biomedical experimentation and for the monitoring of water and air recycling processes on Space Station Freedom. The infrequent logistics flights of the Space Shuttle will necessitate onboard analysis. The advantages of biosensors and chemical sensors over conventional analysis onboard spacecraft are manifold. They require less crew time, space, and power. Sample treatment is not needed. Real time or near-real time monitoring is possible, in some cases on a continuous basis. Sensor signals in digitized form can be transmitted to the ground. Types and requirements for chemical sensors to be used in biomedical experimentation and monitoring of water recycling during long-term space missions are discussed. RP BONTING, SL (reprint author), NASA,AMES RES CTR,SETI INST,1006 & EVELYN AVE,SUNNYVALE,CA 94086, USA. NR 24 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0956-5663 J9 BIOSENS BIOELECTRON JI Biosens. Bioelectron. PY 1992 VL 7 IS 8 BP 535 EP 548 DI 10.1016/0956-5663(92)85005-U PG 14 WC Biophysics; Biotechnology & Applied Microbiology; Chemistry, Analytical; Electrochemistry; Nanoscience & Nanotechnology SC Biophysics; Biotechnology & Applied Microbiology; Chemistry; Electrochemistry; Science & Technology - Other Topics GA JY889 UT WOS:A1992JY88900001 PM 1457091 ER PT J AU Myers, R AF Myers, R BE Covel, J TI Reaching the global village: Guidelines for developing lifelong environmental education programs SO BRIDGES TO UNDERSTANDING LA English DT Proceedings Paper CT 1992 National Interpreters Workshop on Bridges to Understanding - Spanning the Gap Between Talk and Action CY NOV 05-10, 1992 CL SANTA CLARA, CA SP Natl Assoc Interpretat DE awareness; action; global issues; environmental education; lifelong; multi-age; program planning C1 NASA,AMES RES CTR,EARTH SYST SCI DIV,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATIONAL ASSOCIATION INTERPRETATION PI FT COLLINS PA PO BOX 1892, FT COLLINS, CO 80522 PY 1992 BP 260 EP 264 PG 5 WC Education & Educational Research SC Education & Educational Research GA BE83V UT WOS:A1992BE83V00087 ER PT J AU RIUS, A ZARRAOA, N SARDON, E MA, CP AF RIUS, A ZARRAOA, N SARDON, E MA, CP TI CENTIMETER REPEATABILITY OF THE VLBI ESTIMATES OF EUROPEAN BASE-LINES SO BULLETIN GEODESIQUE LA English DT Article ID BASE-LINE INTERFEROMETRY; RADIO INTERFEROMETRY; GEODESY AB In the last three years, the European Geodetic Very Long Baseline Interferometry (VLBI) Network has grown to a total of six fixed antennas placed in Germany, Italy, Spain and Sweden, all equipped with the standard geodetic VLBI instrumentation and data recording systems. During this period of time, several experiments have been carried out using this interferometer providing data of very high quality due to the excellent sensitivity and performance of the European stations. The purpose of this paper is to study the consistency of the VLBI geodetic results on the European baselines with respect to the different degrees of freedom in the analysis procedure. In order to complete this study we have made use of both real and simulated data sets, two different software packages (OCCAM 3.0 and CALC 7.4/SOLVE) and a variety of strategies in the data analysis. The results we have obtained show that the repeatability of the VLBI estimates of the baseline lengths in the European network is better than one centimeter, independent of the different analysis methods, and is consistent with the formal error levels expected from the data analysis. This consistency should be enough to produce geophysically significant information in Europe from VLBI data within a relatively short time span. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP RIUS, A (reprint author), UNIV COMPLUTENSE MADRID,FAC CIENCIAS MATEMAT,CSIC,INST ASTRON & GEODESIA,E-28040 MADRID,SPAIN. RI Ma, Chopo/D-4751-2012; Antonio, Rius/A-4873-2012 OI Antonio, Rius/0000-0002-5947-2649 NR 8 TC 4 Z9 4 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0007-4632 J9 B GEOD JI Bull. Geod. PY 1992 VL 66 IS 1 BP 21 EP 26 DI 10.1007/BF00806807 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA HT070 UT WOS:A1992HT07000003 ER PT J AU SHERIDAN, PF AF SHERIDAN, PF TI COMPARATIVE HABITAT UTILIZATION BY ESTUARINE MACROFAUNA WITHIN THE MANGROVE ECOSYSTEM OF ROOKERY BAY, FLORIDA SO BULLETIN OF MARINE SCIENCE LA English DT Article ID JUVENILE BROWN SHRIMP; PENAEUS-AZTECUS; SPECIES COMPOSITION; SEAGRASS MEADOWS; NORTHWESTERN AUSTRALIA; SEASONAL FLUCTUATIONS; NEARSHORE HABITATS; TROPICAL AUSTRALIA; SALT-MARSH; COMMUNITIES AB Abundance and biomass of juvenile and adult decapods and fishes in adjacent intertidal mangrove, seagrass, and open water habitats were compared using a quantitative drop sampler. Replicate samples were taken in each habitat in July, September and December 1988 and April 1989. Over all samples, fish densities were higher in non-vegetated, open waters (74% of the total caught) than in flooded red mangrove (Rhizophora mangle) prop roots or mixed seagrass beds (13% each). Spotfin mojarra (Eucinostomus argenteus) was the dominant fish collected among prop roots, yellowfin menhaden (Brevoortia smithi), scaled sardine (Harengula jaguana), and striped anchovy (Anchoa hepsetus) were most abundant in open waters, and bay anchovy (A. mitchilli) dominated the catch over seagrasses, although there were seasonal changes in dominant species. Shrimp densities were higher in seagrass habitats (74% of the total captured) than in open waters (22%) or among mangrove prop roots (4%). Habitat dominants were longtail grass shrimp (Periclimenes longicaudatus) and pink shrimp (Penaeus duorarum) in seagrasses, American grass shrimp (P. americanus) in open waters, and Florida grass shrimp (Palaemon floridanus) among mangrove prop roots. Over all samples, crab densities were higher in seagrass habitats (47% of those collected) than in open waters (33%) or mangroves (20%). Habitat dominants were blue crab (Callinectes sapidus), iridescent swimming crab (Portunus gibbesii), and redhair swimming crab (Portunus ordwayi) among seagrasses, green porcelain crab (Petrolisthes armatus) and flatback mud crab (Eurypanopeus depressus) in open waters, and broadback mud crab (Eurytium limosum) in flooded mangroves. On a monthly basis, among-habitat differences in density or biomass of major taxa did not exhibit any patterns, with the exception of shrimp which were always significantly more numerous in seagrasses than in one or both alternate habitats. Flooded red mangroves were, at times, utilized by both resident and transient fishes and crabs (but not by shrimps) at densities similar to those in seagrasses and open waters. RP SHERIDAN, PF (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES CTR,4700 AVE U,GALVESTON,TX 77551, USA. NR 56 TC 68 Z9 71 U1 0 U2 18 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD JAN PY 1992 VL 50 IS 1 BP 21 EP 39 PG 19 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA HP379 UT WOS:A1992HP37900002 ER PT J AU HABIB, S AF HABIB, S BE Cook, ME Hiscock, SA Morrow, H Volpe, RA TI AEROSPACE APPLICATIONS OF NICKEL-CADMIUM BATTERIES SO CADMIUM 92 - EDITED PROCEEDINGS, SEVENTH INTERNATIONAL CADMIUM CONFERENCE, NEW ORLEANS LA English DT Proceedings Paper CT 7th International Cadmium Conference CY APR 06-08, 1992 CL NEW ORLEANS, LA SP CADMIUM ASSOC, LONDON, CADMIUM COUNCIL INC, RESTON, INT LEAD ZINC RES ORG INC, RES TRIANGLE PK C1 NASA HEADQUARTERS,WASHINGTON,DC. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CADMIUM ASSOC PI LONDON PA 42 WEYMOUTH ST, LONDON, ENGLAND W1N 3LQ PY 1992 BP 30 EP 33 PG 4 WC Public, Environmental & Occupational Health; Toxicology SC Public, Environmental & Occupational Health; Toxicology GA BZ85F UT WOS:A1992BZ85F00009 ER PT J AU FAIRBRIDGE, RW AF FAIRBRIDGE, RW TI SHOULD THE PLEISTOCENE - HOLOCENE BOUNDARY BE PLACED AT TERMINATION 1A SO CANADIAN JOURNAL OF EARTH SCIENCES LA English DT Letter RP FAIRBRIDGE, RW (reprint author), GODDARD INST SPACE STUDIES, 2880 BROADWAY AVE, NEW YORK, NY 10025 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0008-4077 EI 1480-3313 J9 CAN J EARTH SCI JI Can. J. Earth Sci. PD JAN PY 1992 VL 29 IS 1 BP 1 EP 2 DI 10.1139/e92-001 PG 2 WC Geosciences, Multidisciplinary SC Geology GA HL571 UT WOS:A1992HL57100002 ER PT J AU NORBURY, JW KAHANA, DE MAUNG, KM AF NORBURY, JW KAHANA, DE MAUNG, KM TI CONFINING POTENTIAL IN MOMENTUM SPACE SO CANADIAN JOURNAL OF PHYSICS LA English DT Article ID INTEGRAL-EQUATIONS; CHARMONIUM; MODEL AB A method is presented for the solution in momentum space of the bound-state problem with a linear potential in r space. The potential is unbounded at large r leading to a singularity at small q. The singularity is integrable, when regulated by exponentially screening the r-space potential, and is removed by a subtraction technique. The limit of zero screening is taken analytically, and the numerical solution of the subtracted integral equation gives eigenvalues and wave functions in good agreement with position space calculations. C1 CONTINUOUS ELECTRON BEAM ACCELERATOR FACIL,NEWPORT NEWS,VA 23606. HAMPTON UNIV,DEPT PHYS,HAMPTON,VA 23668. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP NORBURY, JW (reprint author), RIDER COLL,DEPT PHYS,LAWRENCEVILLE,NJ 08648, USA. OI Kahana, David Ewan/0000-0003-1266-9089 NR 13 TC 19 Z9 20 U1 0 U2 0 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4204 J9 CAN J PHYS JI Can. J. Phys. PD JAN PY 1992 VL 70 IS 1 BP 86 EP 89 PG 4 WC Physics, Multidisciplinary SC Physics GA HM024 UT WOS:A1992HM02400009 ER PT J AU GAIER, JR LAKE, ML MOINUDDIN, A MARABITO, M AF GAIER, JR LAKE, ML MOINUDDIN, A MARABITO, M TI PROPERTIES OF HYBRID CVD/PAN GRAPHITE FIBERS AND THEIR BROMINE INTERCALATION COMPOUNDS SO CARBON LA English DT Article DE CARBON FIBERS; CVD; INTERCALATION; BROMINE ID CARBON-FIBERS; TEMPERATURE AB A hybrid fiber with a PAN core surrounded by a vapor-grown carbon-fiber (VGCF) sheath has been fabricated using a proprietary process. The density, ultimate tensile strength, Young's modulus, and resistivity of pristine and bromine-intercalated fibers made by this technique, having diameters varying from 5 to 50-mu-m, were compared with the values predicted from the rule-of-mixtures model. For both the pristine and intercalated fibers, the density, ultimate tensile strength, and Young's modulus of the fibers were lower than predicted, but resistivity was measured to be consistent with predictions. Intercalation had little, if any, effect on ultimate tensile strength and Young's modulus, but raised the density by about 11 percent, and lowered resistivity by an order of magnitude. The diameter dependence of the resistivity showed evidence of a depletion layer of the type found in VGCF. C1 APPL SCI INC,YELLOW SPRINGS,OH 45387. CLEVELAND STATE UNIV,CLEVELAND,OH 44115. RP GAIER, JR (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 15 TC 3 Z9 3 U1 2 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0008-6223 J9 CARBON JI Carbon PY 1992 VL 30 IS 3 BP 345 EP 349 DI 10.1016/0008-6223(92)90029-V PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA HP921 UT WOS:A1992HP92100006 ER PT B AU BORDERIES, N AF BORDERIES, N BE FERRAZMELLO, S TI LOOKING FOR CHANGES IN THE SATURNIAN SYSTEM BETWEEN VOYAGER AND CASSINI SO CHAOS, RESONANCE AND COLLECTIVE DYNAMICAL PHENOMENA IN THE SOLAR SYSTEM SE IAU SYMPOSIA LA English DT Proceedings Paper CT 152ND SYMP OF THE INTERNATIONAL ASTRONOMICAL UNION : CHAOS, RESONANCE AND COLLECTIVE DYNAMICAL PHENOMENA IN THE SOLAR SYSTEM CY JUL 15-19, 1991 CL ANGRA DOS REIS, BRAZIL SP INT ASTRON UNION, COMMISS CELESTIAL MECH, INT ASTRON UNION, COMMISS PHYS STUDY PLANET & SATELLITES, INT ASTRON UNION, COMMISS POSIT & MOT MINOR PLANETS COMETS & SATELLITES, NATL COUNCIL SCI DEV BRAZIL, STATE SAO PAULO, RES FDN, UNIV SAO PAULO, OBSERV NACL DE PLANETARY RINGS DYNAMICS RP BORDERIES, N (reprint author), JET PROPULS LAB 301-150,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA DORDRECHT BN 0-7923-1782-3 J9 IAU SYMP PY 1992 VL 152 BP 53 EP 64 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW26V UT WOS:A1992BW26V00009 ER PT J AU LARKIN, DJ INTERRANTE, LV AF LARKIN, DJ INTERRANTE, LV TI CHEMICAL VAPOR-DEPOSITION OF SILICON-CARBIDE FROM 1,3-DISILACYCLOBUTANE SO CHEMISTRY OF MATERIALS LA English DT Note ID GAS-PHASE; PYROLYSIS; MECHANISM; KINETICS C1 RENSSELAER POLYTECH INST,DEPT CHEM,TROY,NY 12180. RP LARKIN, DJ (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 18 TC 33 Z9 33 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JAN-FEB PY 1992 VL 4 IS 1 BP 22 EP 24 DI 10.1021/cm00019a009 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA HC558 UT WOS:A1992HC55800010 ER PT J AU NOOR, AK TENEK, LH AF NOOR, AK TENEK, LH TI STIFFNESS AND THERMOELASTIC COEFFICIENTS FOR COMPOSITE LAMINATES SO COMPOSITE STRUCTURES LA English DT Article AB Simple analytic expressions are presented for the stiffness and thermoelastic coefficients of composite laminates in terms of the material properties of the individual layers. Expressions for the derivatives of the various coefficients with respect to each of the material properties and fiber orientation angles are also included. For typical high-performance composites, numerical values are given showing the effects of the stacking sequence and the fiber orientation angle of quasi-isotropic and angle-ply laminates on the values of the various coefficients and their sensitivity derivatives. The expressions for the thermoelastic cocfficients and the sensitivity derivatives are given herein for the first time. RP NOOR, AK (reprint author), UNIV VIRGINIA,NASA,LANGLEY RES CTR,CTR COMPUTAT STRUCT TECHNOL,HAMPTON,VA, USA. NR 15 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0263-8223 J9 COMPOS STRUCT JI Compos. Struct. PY 1992 VL 21 IS 1 BP 57 EP 66 DI 10.1016/0263-8223(92)90080-V PG 10 WC Materials Science, Composites SC Materials Science GA HT215 UT WOS:A1992HT21500007 ER PT J AU ESPINOSA, PS GROEPLER, DR AF ESPINOSA, PS GROEPLER, DR TI TILTROTOR RESEARCH AIRCRAFT COMPOSITE BLADE REPAIRS - LESSONS LEARNED SO COMPOSITES ENGINEERING LA English DT Article AB The XV-15, N703NA Tiltrotor Research Aircraft located at the NASA Ames Research Center, Moffett Field, California, currently uses a set of composite rotor blades of complex shape known as the advanced technology blades (ATBs). The main structural element of the blades is a D-spar constructed of unidirectional, angled fiberglass/graphite, with the aft-fairing portion of the blades constructed of a fiberglass cross-ply skin bonded to a Nomex honeycomb core. The blade tip is a removable laminate shell that fits over the outboard section of the spar structure, which contains a cavity to retain balance weights. Two types of tip shells are used for research. One is highly twisted (more than a conventional helicopter blade) and has a hollow core constructed of a thin Nomex-honeycomb-and-fiberglass-skin sandwich; the other is untwisted with a solid Nomex honeycomb core and a fiberglass cross-ply skin. During initial flight testing of the blades, a number of problems in the composite structure were encountered. These problems included debonding between the fiberglass skin and the honeycomb core, failure of the honeycomb core, failures in fiberglass splices, cracks in fiberglass blocks, misalignment of mated composite parts, and failures of retention of metal fasteners. Substantial time was spent in identifying and solving these problems. This paper discusses the types of problems encountered, the inspection procedures used to identify each problem, the repairs performed on the damaged or flawed areas, the level of criticality of the problems, and the subsequent monitoring of repaired areas. It is hoped that this discussion will help designers, analysts and experimenters in the future as the use of composites becomes more prevalent. RP ESPINOSA, PS (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 4 TC 0 Z9 0 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0961-9526 J9 COMPOS ENG JI Compos. Eng. PY 1992 VL 2 IS 5-7 BP 477 EP 495 DI 10.1016/0961-9526(92)90038-8 PG 19 WC Engineering, Multidisciplinary; Materials Science, Composites SC Engineering; Materials Science GA HZ762 UT WOS:A1992HZ76200012 ER PT J AU KULKARNI, D KUTULAKOS, K ROBINSON, P AF KULKARNI, D KUTULAKOS, K ROBINSON, P TI DATA-ANALYSIS USING SCALE-SPACE FILTERING AND BAYESIAN PROBABILISTIC REASONING SO COMPUTERS & CHEMISTRY LA English DT Article ID RECOGNITION; EDGES AB This paper describes a program for the analysis of output curves from a differential thermal analyzer (DTA). The program first extracts probabilistic qualitative features from a DTA curve of a soil sample, and then uses Bayesian probabilistic reasoning to infer what minerals are present in the soil. It consists of a qualifier module and a classifier module. The qualifier employs a simple and efficient extension of scale-space filtering DTA data. Ordinarily when filtering operations are not highly accurate, points can vanish from contours in the scale-space image. To handle the problem of vanishing points, our algorithm uses perceptual organization heuristics to group the points into lines. It then groups these lines into contours by using additional heuristics. Probabilities are associated with these contours using domain-specific correlations. A Bayes tree classifier processes probabilistic features to infer the presence of different minerals in the soil. We show experimentally that using domain-specific correlations to infer qualitative features, this algorithm outperforms a domain-independent algorithm that does not. C1 UNIV WISCONSIN,DEPT COMP SCI,MADISON,WI 53706. RP KULKARNI, D (reprint author), NASA,AMES RES CTR,AI RES BRANCH,MAIL STOP 244-17,MOFFETT FIELD,CA 94035, USA. NR 12 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0097-8485 J9 COMPUT CHEM JI Comput. Chem. PD JAN PY 1992 VL 16 IS 1 BP 15 EP 23 DI 10.1016/0097-8485(92)85003-H PG 9 WC Chemistry, Multidisciplinary; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA HH767 UT WOS:A1992HH76700003 ER PT J AU KHAN, HJ RHEE, M FIGUEROA, O AF KHAN, HJ RHEE, M FIGUEROA, O TI CHARACTERIZATION OF GASEOUS HELIUM JET DISPERSION TO ATMOSPHERE SO CRYOGENICS LA English DT Article DE HELIUM; SHOOT; SPACE CRYOGENICS AB A major ground based experiment to be performed for the Superfluid Helium On Orbit Transfer (SHOOT) programme is the accidental loss of the vacuum guard of the super-insulated dewar. The design of the dewar vent path requires adequate mass removal after a preset pressure is reached due to external heat transfer. The exiting helium creates a turbulent buoyant jet, expanding in air with entrainment of the jet interface to the surrounding. Transient analysis is performed for axial and radial jet temperature prediction using the self-similarity assumption applied to mass, momentum and the energy balance equations of helium. The predicted jet temperature profiles with vertical and radial expansion up to 1.6 and 1.0 m, respectively, demonstrate the low temperature core established by gaseous helium. For all time steps, the axial and radial temperature predictions are observed to be within 8 and 20%, respectively. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP KHAN, HJ (reprint author), UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 1 BP 20 EP 27 DI 10.1016/0011-2275(92)90339-C PG 8 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HN073 UT WOS:A1992HN07300003 ER PT J AU ARIF, H AF ARIF, H TI 10TH SPACE CRYOGENICS WORKSHOP SO CRYOGENICS LA English DT Editorial Material RP ARIF, H (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 75 EP 76 DI 10.1016/0011-2275(92)90246-7 PG 2 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200001 ER PT J AU VOLZ, SM DIPIRRO, MJ AF VOLZ, SM DIPIRRO, MJ TI ANOMALOUS ON-ORBIT BEHAVIOR OF THE NASA COSMIC BACKGROUND EXPLORER (COBE) DEWAR SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE SPACE CRYOGENICS; LIQUID HELIUM; ON-ORBIT BEHAVIOR AB The cryogenic operation of NASA's Cosmic Background Explorer (COBE) ended on September 21, 1990, with the depletion of the liquid helium cryogen, after COBE had completed more than 10 months of successful Dewar and instrument operation. In this report we provide a brief summary of the nominal cryogenic performance of the Dewar (for more detail consult Reference 1). We present in detail several aspects of the helium and spacecraft dynamical behaviour. We discuss the occurrence of temperature and pressure oscillations in the Dewar porous plug. We review the impact of internal instrument malfunctions and of external radiation sources on the performance of the Dewar and of the instruments. From measurements of the COBE spacecraft spin rate we are able to monitor the spin coupling of the liquid helium to the walls of the Dewar. We analyse the spin measurements and present a model for the coupling. Finally, we review a number of helium Dewar 'lessons learned' from the COBE mission, and remark on the applicability of these lessons to future missions involving cryogenic payloads. RP VOLZ, SM (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 713,GREENBELT,MD 20771, USA. NR 8 TC 5 Z9 5 U1 1 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 77 EP 84 DI 10.1016/0011-2275(92)90247-8 PG 8 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200002 ER PT J AU DIPIRRO, MJ SHIRRON, PJ AF DIPIRRO, MJ SHIRRON, PJ TI THE SHOOT ORBITAL OPERATIONS SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE SPACE CRYOGENICS; SHOOT; SUPERFLUID HELIUM AB The Superfluid Helium On Orbit Transfer (SHOOT) flight demonstration programme will provide the technology necessary to resupply liquid helium in space. If used in a tanker the components in SHOOT will be full scale except for tank size. The SHOOT attached shuttle payload orbital operations are divided roughly into two categories: an experiment and a demonstration. The experiment involves qualitative and quantitative measurements of the behaviour of various liquid management devices such as liquid acquisition devices, phase separators and liquid/vapour discriminators. Total system performance will also be measured in terms of transfer rates, losses, and residual quantities of helium. Parameters such as low level acceleration, temperature and pumping speed will be varied to obtain data needed to verify concepts and theoretical predictions. The demonstration involves combining data from early in the flight with an on board expert system to perform a transfer autonomously from the shuttle, thus simulating an actual superfluid resupply mission. The paper describes the SHOOT on orbit operations, the reasons for the methods used to obtain the experimental data, and the expected results. RP DIPIRRO, MJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 713,GREENBELT,MD 20771, USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 85 EP 90 DI 10.1016/0011-2275(92)90248-9 PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200003 ER PT J AU MASON, PV PETRAC, D PETRICK, SW STRAYER, DM AF MASON, PV PETRAC, D PETRICK, SW STRAYER, DM TI SPACE INFRARED TELESCOPE FACILITY MISSION AND CRYOGENIC DESIGN SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE INFRARED ASTRONOMY; SPACE CRYOGENICS; SUPERFLUID HELIUM AB The Space Infrared Telescope Facility (SIRTF) is the last of the Great Observatory missions. It is presently scheduled for launch in 2001. The mission will study the infrared spectrum from 2 to 1200-mu-m with three imaging and spectral instruments. The observatory will have a 5 year lifetime and will be placed in a 100 000 km earth orbit. The cryogenic system is based on a 4000 I superfluid helium cryostat. The mission and the cryogenic system are described, and the cryogenic technology issues are discussed. RP MASON, PV (reprint author), NASA,JET PROPULS LAB,PASADENA,CA, USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 107 EP 110 DI 10.1016/0011-2275(92)90251-5 PG 4 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200006 ER PT J AU HOPKINS, RA NIECZKOSKI, SJ PAYNE, DA SIEBERT, JF BREON, SR AF HOPKINS, RA NIECZKOSKI, SJ PAYNE, DA SIEBERT, JF BREON, SR TI MECHANICAL COOLER-TO-DEWAR INTERFACING IN A LONG-LIFETIME, HYBRID STORED CRYOGEN SYSTEM SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE SUPERFLUID HELIUM DEWAR; MECHANICAL COOLERS; HYBRID CRYOGENIC SYSTEM AB The cryogenic subsystem for the Advanced X-Ray Astrophysics Facility (AXAF) X-Ray Spectrometer (XRS) represents a new breed of long-lifetime, hybrid stored cryogen system. The design achieves a predicted lifetime of 5 years with only 480 I of superfluid helium by using mechanical coolers to limit the parasitic heating into the Dewar. The system uses two momentum-compensated pairs of split, Stirling-cycle coolers to cool the Dewar outer vapour-cooled shield. Use of the 80 K coolers can reduce the helium loss rate by about a factor of 3. This paper primarily addresses the means for making efficient use of the coolers. Thermal efficiency is achieved by minimizing the parasitic heating and thermal impedance of the cooler-to-Dewar interface within the mechanical constraints. The important issues related to compatibility with the instrument system are also briefly discussed. Parasitic heating from the non-operating (reserved or failed) cooler pair can be reduced with an active thermal switch that isolates the cooler cold tips from the cold finger. Analysis was performed to determine optimal switch operating characteristics for this application. Requirements associated with use of the coolers, analyses performed and the interface design concept are discussed. Component development is continuing. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP HOPKINS, RA (reprint author), BALL ELECTROOPT,DIV CRYOGEN,POB 1062,BOULDER,CO 80306, USA. NR 7 TC 1 Z9 1 U1 1 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 111 EP 116 DI 10.1016/0011-2275(92)90252-6 PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200007 ER PT J AU SERLEMITSOS, AT SANSEBASTIAN, M KUNES, E AF SERLEMITSOS, AT SANSEBASTIAN, M KUNES, E TI DESIGN OF A SPACEWORTHY ADIABATIC DEMAGNETIZATION REFRIGERATOR SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE SPACE CRYOGENICS; REFRIGERATORS; ADIABATIC DEMAGNETIZATION ID RAY AB Goddard Space Flight Center (GSFC) is presently developing an X-ray spectrometer (XRS) to be flown aboard the Advanced X-ray Astrophysics Facility (AXAF). XRS uses an array of 32 microcalorimeters, capable of detecting X-rays in the energy range of 0.3 - 10 keV with a resolution of 12 eV. In order to accomplish this the detectors must be operated at a temperature of 0.065 K. In space, an adiabatic demagnetization refrigerator (ADR) must be used to cool the detectors to that temperature. A spaceworthy ADR has been under development at GSFC for almost a decade. When XRS because a viable AXAF candidate, the development effort intensified. A baseline model heat switch has been tested extensively with an on/off ratio of approximately 10 000 and a parasitic heat leak of 10-mu-W. In the same time period various salt pills have been built employing different methods of thermal contact and of crystal growth. We are presently in the process of building the engineering model of the ADR. Using the data obtained from the breadboard models we have designed an ADR with improved structural integrity while, at the same time, improving on its efficiency and performance. The new ADR design will be reported in detail. RP SERLEMITSOS, AT (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 713,GREENBELT,MD 20771, USA. NR 6 TC 21 Z9 21 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 117 EP 121 DI 10.1016/0011-2275(92)90253-7 PG 5 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200008 ER PT J AU SHIRRON, PJ DIPIRRO, MJ AF SHIRRON, PJ DIPIRRO, MJ TI LOW GRAVITY THERMAL STRATIFICATION OF LIQUID-HELIUM ON SHOOT SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE SPACE CRYOGENICS; SHOOT; THERMAL STRATIFICATION AB The Superfluid Helium On-Orbit Transfer (SHOOT) Flight Demonstration is a Shuttle attached payload designed to demonstrate the technology needed to transfer superfluid helium in space. It is a unique liquid helium payload in that it will launch with normal helium which will be pumped to superfluid temperatures after orbit insertion by means of a liquid/vapour phase separator capable of operating with both He-I and He-II at its inlet. Tests of this phase separator in one gravity have shown that when the phase separator provides cooling to the bottom of the Dewar (minimizing convection) the bulk liquid thermally stratifies. The stratification can be so pronounced that a distinct phase boundary appears between He-I at 4.2 K above He-II just at T(lambda) which exhibits behaviour characteristic of a liquid/vapour boundary or that between two liquids. In the very low gravity environment of space it is expected that such an interface will occur and, once established, will persist due to the difference in surface tension between He-I and He-II and the poor thermal conductivity of He-I. For SHOOT, thermal stratification is a benefit both during ground hold on the launch pad and after launch. When stratification occurs during ground hold parasitic heat inputs are more efficiently removed. After launch, the pressure inside the Dewars will be enhanced if the liquid stratifies, resulting in higher mass flow rates through the phase separator and consequently shorter pumpdown times. Estimates of the extent and impact of thermal stratification will be presented as well as predictions of the behaviour of the He-I/He-II boundary. RP SHIRRON, PJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 713,GREENBELT,MD 20771, USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 159 EP 166 DI 10.1016/0011-2275(92)90260-H PG 8 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200015 ER PT J AU JURNS, JM JACOBS, RE SAIYED, NH AF JURNS, JM JACOBS, RE SAIYED, NH TI DESCRIPTION OF LIQUID-NITROGEN EXPERIMENTAL TEST FACILITY SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE NITROGEN; TEST TANK; CRYOGENIC LIQUIDS AB The Liquid Nitrogen Experimental Test Facility is a unique test facility for ground-based liquid nitrogen experimentation. The test rig consists of an insulated tank of approximately 354 dm3 in volume, which is supplied with liquid nitrogen from a 1135 dm3 dewar via a vacuum jacketed piping system. The test tank is fitted with pressure and temperature measuring instrumentation and with two view ports, which allow visual observation of test conditions. To demonstrate the capabilities of the facility, the initial test programme is briefly described. The objective of the test programme is to measure the condensation rate by injecting liquid nitrogen as a subcooled spray into the ullage of a tank 50% full of liquid nitrogen at saturated conditions. The condensation rate of the nitrogen vapour on the subcooled spray can be analytically modelled, and results validated and corrected by experimentally measuring the vapour condensation on liquid sprays. C1 ANALEX CORP,NASA LEWIS RES CTR GRP,CLEVELAND,OH. NASA,CLEVELAND,OH 44135. RP JURNS, JM (reprint author), SVERDRUP TECHNOL INC,NASA,LEWIS RES CTR GRP,CLEVELAND,OH, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 173 EP 178 DI 10.1016/0011-2275(92)90262-9 PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200017 ER PT J AU BIRUR, GC TSUYUKI, GT AF BIRUR, GC TSUYUKI, GT TI A SIMPLIFIED GENERIC CRYOSTAT THERMAL-MODEL FOR PREDICTING CRYOGEN MASS AND LIFETIME SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE CRYOSTATS; CRYOGENS; THERMAL PROPERTIES AB A simple generic cryostat thermal model has been developed for the purpose of predicting cryogen mass and lifetime of cryogenic space telescopes. The model was created for use with the Martin Marietta thermal analyser, mini-MITAS, on microcomputers. The model is based on a lumped parameter representation of eight nodes and over 35 conductors. The major telescope dewar components represented as nodes are the main cryogen tank, the three vapour-cooled shields, the outer shell, barrel baffle and the barrel baffle heat exchanger. The input to the model consists of the vapour-cooled shield, support straps and instrument cable geometry and the cryostat heat loads from the instrument and through the aperture. The outer shell and superfluid helium temperatures are assumed to be known. The predictions from the model were compared with those from the more detailed models of IRAS, COBE and SIRTF. Correlation of the helium flow rates of the IRAS and COBE Dewars was 12% above the actual flight or ground test data and for SIRTF it was less than 2% of the prediction from the detailed model. Currently, this model is being used for the conceptual design studies of the Submillimetre Imager and Line Survey (SMILS) telescope. RP BIRUR, GC (reprint author), CALTECH,JET PROP LAB,APPL TECHNOL SECT,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 11 TC 0 Z9 0 U1 1 U2 4 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 185 EP 190 DI 10.1016/0011-2275(92)90264-B PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200019 ER PT J AU INGEBO, RD AF INGEBO, RD TI EFFECT OF GAS MASS FLUX ON CRYOGENIC LIQUID JET BREAKUP SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE CRYOGENIC LIQUIDS; SPRAYS; LIGHT-SCATTERING INSTRUMENT ID DROP-SIZE AB A scattered-light scanning instrument developed at NASA Lewis Research Center was used to measure the characteristic drop size of clouds of liquid nitrogen droplets. The instrument was calibrated with suspensions of monosized polystyrene spheres. In this investigation of the mechanism of liquid nitrogen jet disintegration in a high-velocity gas flow, the Sauter mean diameter, D32, was found to vary inversely with the nitrogen gas mass flux raised to the power 1.33. Values of D32 varied from 5 to 25-mu-m and the mass flux exponent of 1.33 agrees well with theory for liquid jet breakup in high-velocity gas flows. The loss of very small droplets due to the high vaporization rate of liquid nitrogen was avoided by sampling the spray very close to the atomizer, i.e. 1.3 cm downstream of the nozzle orifice. The presence of high velocity and thermal gradients in the gas phase also made sampling of the particles difficult. As a result, it was necessary to correct the measurements for background noise produced by both highly turbulent gas flows and thermally induced density gradients in the gas pase. RP INGEBO, RD (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 11 TC 4 Z9 4 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 191 EP 193 DI 10.1016/0011-2275(92)90265-C PG 3 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200020 ER PT J AU TAYLOR, WJ CHATO, DJ MORAN, MM NYLAND, TW AF TAYLOR, WJ CHATO, DJ MORAN, MM NYLAND, TW TI ON-ORBIT CRYOGENIC FLUID TRANSFER RESEARCH AT NASA-LEWIS-RESEARCH-CENTER SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE CRYOGENIC LIQUIDS; FLUID TRANSFER; NO-VENT FILLING AB Cryogenic fluid transfer operations in the low-gravity environment of Earth orbit are necessary for many NASA mission concepts. Fluid transfer brings several benefits to the performance of space missions. Spacecraft already on orbit can be resupplied with cryogenic propellants, coolant fluids and other liquids. Lighter weight spacecraft can be built, since as they are launched dry and supplied on orbit they are not required to support the weight of cryogens during the 3-6g launch environment. The filling of cryogenic tanks in low gravity poses an operational challenge. Among the difficulties encountered are vapour generation due to the energy stored in the tank walls and the uncertainty of liquid and vapour distributions in a tank in a low-gravity environment. Increased support for technological research in recent years has enabled NASA Lewis Research Center (LeRC) personnel to make significant advances in the state of the art of cryogenic fluid transfer operations via the no-vent fill method. This paper presents a summary of the results obtained to date in the ongoing programme at LeRC. The LeRC programme has two purposes, emphasizing an extensive ground test programme which is augmented by the development of analytical models for the no-vent fill transfer operation processes. Additionally, planning for the future development of this technology is continuing. This ongoing research effort should, in the near future, permit the design of space systems and spacecraft that benefit from the reusability and weight savings accrued through the use of cryogenic fluid transfer operations in a low-gravity environment. RP TAYLOR, WJ (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. RI Chato, David/B-2698-2013 OI Chato, David/0000-0003-2990-0646 NR 7 TC 5 Z9 7 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 199 EP 204 DI 10.1016/0011-2275(92)90267-E PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200022 ER PT J AU BELL, RS VENTO, DM HANNA, GJ AF BELL, RS VENTO, DM HANNA, GJ TI CONE - AN STS-BASED CRYOGENIC FLUID MANAGEMENT EXPERIMENT SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE CRYOGENIC LIQUIDS; NITROGEN; SPACE TRANSPORT SYSTEM AB The Cryogenic Orbital Nitrogen Experiment (CONE) is an STS-based liquid nitrogen system, designed to investigate many of the enabling technologies identified as critical elements by the Cryogenic Fluids Technology Office (CFTO) of NASA/Lewis Research Center. These technologies will support a number of projected NASA and DOD missions which would require low-gravity cryogenic fluid management. CONE will provide much of the data required to understand and design the hardware to complete these missions. A refined conceptual design has been completed which maximizes the experimental return within the operational constraints of the Space Transportation System (STS). This overview of the CONE programme includes definition of the technology addressed by CONE and a baseline experiment set, a description of the experimental and support subsystems, interface requirements between the STS and the experiment carrier (Hitchhiker-M) and the reusability and expansion capacity for additional experiment flights. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. HANNA TECHNOL RESOURCES,BOULDER,CO. RP BELL, RS (reprint author), BALL ELECTROOPT,DIV CRYOGEN,POB 1062,BOULDER,CO 80306, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 215 EP 220 DI 10.1016/0011-2275(92)90270-K PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200025 ER PT J AU BAILEY, WJ ARIF, H AF BAILEY, WJ ARIF, H TI CRYOGENIC FLUID MANAGEMENT INVESTIGATIONS USING THE CONE FLIGHT EXPERIMENT SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE CRYOGENIC LIQUIDS; SUBCRITICAL STORAGE; NITROGEN AB The Cryogenic Orbital Nitrogen Experiment (CONE) is a liquid nitrogen cryogenic storage and supply system demonstration placed in orbit by the National Space Transportation System (NSTS) Orbiter and operated as an in-bay payload whose objective is to demonstrate needed critical components and technologies. A conceptual approach has been developed by Martin Marietta under contract with the NASA Lewis Research Center and an overview of the CONE program is described which includes a definition of the background and scope of the technology objectives being investigated, a description of the payload design and operation, major features and rationale for the experiments being conducted and the justification for CONE relating to potential near-term benefits and risk mitigation for future systems. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP BAILEY, WJ (reprint author), MARTIN MARIETTA ASTRONAUT GRP,CIVIL SPACE & COMMUN,DENVER,CO 80201, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 221 EP 229 DI 10.1016/0011-2275(92)90271-B PG 9 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200026 ER PT J AU FISHER, MF SCHMIDT, GR MARTIN, JJ AF FISHER, MF SCHMIDT, GR MARTIN, JJ TI ANALYSIS OF CRYOGENIC PROPELLANT BEHAVIOR IN MICROGRAVITY AND LOW THRUST ENVIRONMENTS SO CRYOGENICS LA English DT Article; Proceedings Paper CT 10TH SPACE CRYOGENICS WORKSHOP CY JUN 18-20, 1991 CL NASA LEWIS RES CTR, CLEVELAND, OH SP NASA, HEADQUARTERS OFF AERONAUT EXPLORAT & TECHNOL HO NASA LEWIS RES CTR DE SPACE CRYOGENICS; PROPELLANTS; MICROGRAVITY AB Understanding the behaviour and response of cryogenic propellants during spacecraft flight operations (e.g., engine restart and fluid transfer) is an extremely important aspect of vehicle design. Accurate predictions of fluid motion and slosh amplification are needed to ensure proper settling prior to engine burn and effective vehicle control throughout all phases of the mission. To augment analyses of this type, Marshall Space Flight Center (MSFC) recently acquired FLOW-3D, a CFD package developed by Flow Sciences Inc. This paper describes a recent validation in which FLOW-3D model predictions were compared with MSFC drop tower test data. Although the tests were originally conducted in the 1960s to support design and performance assessments of the Saturn S-IVB stage liquid hydrogen (LH2), tank, the data have proven useful for verifying the accuracy of the FLOW3D model. RP FISHER, MF (reprint author), NASA,MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35824, USA. NR 3 TC 2 Z9 3 U1 0 U2 4 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 2 BP 230 EP 235 DI 10.1016/0011-2275(92)90272-C PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HC122 UT WOS:A1992HC12200027 ER PT J AU KHAN, HJ ZHANG, QQ RHEE, M FIGUEROA, O AF KHAN, HJ ZHANG, QQ RHEE, M FIGUEROA, O TI BLOW-DOWN ANALYSIS OF HELIUM FROM A CRYOGENIC DEWAR SO CRYOGENICS LA English DT Article DE DEWARS; BLOW-DOWN; HELIUM AB NASA is currently developing space shuttle-based refilling of helium using superfluid helium on-orbit transfer (SHOOT). All the critical components of SHOOT need to be developed through ground-based tests. The helium Dewar is one of these components. The Dewar consists of a vacuum vessel enclosing a superinsulated tank. The space between the vacuum vessel and the liquid tank is considered a common vacuum space. In the event that the vacuum is lost, the heat transfers to the Dewar and the pressure inside the Dewar increases rapidly, resulting in rupture of the Dewar due to excessive pressure. Therefore, an emergency vent line is required for release of helium to prevent the Dewar from rupturing. The study describes a numerical model for blow-down analysis in an emergency. This qualifies the design of the emergency vent line to be adequate for the assumed heat loads to the helium Dewar. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP KHAN, HJ (reprint author), UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742, USA. NR 9 TC 1 Z9 1 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 4 BP 388 EP 398 DI 10.1016/0011-2275(92)90059-J PG 11 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA HJ741 UT WOS:A1992HJ74100008 ER PT J AU KITTEL, P AF KITTEL, P TI IDEAL ORIFICE PULSE TUBE REFRIGERATOR PERFORMANCE SO CRYOGENICS LA English DT Note DE PULSE TUBES; REFRIGERATORS; EFFICIENCY AB Using an analogy to the Stirling cycle refrigerator, the efficiency (cooling power per unit input power) of an ideal orifice pulse tube refrigerator is shown to be T1/T0, the ratio of the cold temperature to the hot temperature. RP KITTEL, P (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 2 TC 37 Z9 38 U1 1 U2 6 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PY 1992 VL 32 IS 9 BP 843 EP 844 DI 10.1016/0011-2275(92)90320-A PG 2 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA JK989 UT WOS:A1992JK98900014 ER PT B AU GURUSWAMY, GP AF GURUSWAMY, GP BE Davis, MR Walker, GJ TI VORTICAL FLOW COMPUTATIONS ON A FLEXIBLE BLENDED WING-BODY COMBINATION SO ELEVENTH AUSTRALASIAN FLUID MECHANICS CONFERENCE, VOLS 1 AND 2 LA English DT Proceedings Paper CT 11th Australasian Fluid Mechanics Conference CY DEC 14-18, 1992 CL UNIV TASMANIA, HOBART, AUSTRALIA HO UNIV TASMANIA C1 NASA,AMES RES CTR,COMPUTAT AEROSCI BRANCH,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVERSITY TASMANIA PI HOBART PA GPOB 252C TASMANIA, HOBART 7001, AUSTRALIA BN 0-85901-519-X PY 1992 BP 211 EP 214 PG 4 WC Engineering, Mechanical SC Engineering GA BB94T UT WOS:A1992BB94T00051 ER PT B AU KHORRAMI, MR AF KHORRAMI, MR BE Davis, MR Walker, GJ TI THE EFFECT OF SWIRL ON THE STABILITY OF A COMPRESSIBLE AXISYMMETRIC JET SO ELEVENTH AUSTRALASIAN FLUID MECHANICS CONFERENCE, VOLS 1 AND 2 LA English DT Proceedings Paper CT 11th Australasian Fluid Mechanics Conference CY DEC 14-18, 1992 CL UNIV TASMANIA, HOBART, AUSTRALIA HO UNIV TASMANIA C1 NASA,LANGLEY RES CTR,HIGH TECHNOL CORP,HAMPTON,VA 23665. NR 0 TC 1 Z9 1 U1 0 U2 1 PU UNIVERSITY TASMANIA PI HOBART PA GPOB 252C TASMANIA, HOBART 7001, AUSTRALIA BN 0-85901-519-X PY 1992 BP 1101 EP 1104 PG 4 WC Engineering, Mechanical SC Engineering GA BB94T UT WOS:A1992BB94T00267 ER PT B AU ATWOODCA VANDALSEM, WR AF ATWOODCA VANDALSEM, WR BE Davis, MR Walker, GJ TI A NUMERICAL STUDY OF COMPLEX CAVITY FLOWS VIA THE NAVIER-STOKES EQUATIONS SO ELEVENTH AUSTRALASIAN FLUID MECHANICS CONFERENCE, VOLS 1 AND 2 LA English DT Proceedings Paper CT 11th Australasian Fluid Mechanics Conference CY DEC 14-18, 1992 CL UNIV TASMANIA, HOBART, AUSTRALIA HO UNIV TASMANIA C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVERSITY TASMANIA PI HOBART PA GPOB 252C TASMANIA, HOBART 7001, AUSTRALIA BN 0-85901-519-X PY 1992 BP 1233 EP 1236 PG 4 WC Engineering, Mechanical SC Engineering GA BB94T UT WOS:A1992BB94T00300 ER PT J AU BEDDINGFIELD, ST AF BEDDINGFIELD, ST TI A NEW ENDEAVOR SO ENDEAVOUR LA English DT Article AB The American Space Shuttle Program is adding a new orbiter to its fleet. Like this journal, the new orbiter - serial number OV-105 - is named Endeavour after the ship used by Captain James Cook on his first trip to explore the Pacific Ocean. It is similar to the other three orbiters already in the fleet but has some new features that reflect state-of-the-art improvements and satisfaction of new requirements. C1 NASA,KENNEDY SPACE CTR,SPACE SHUTTLE PROJECTS MANAGEMENT,CAPE CANAVERAL,FL. NR 15 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0160-9327 J9 ENDEAVOUR JI Endeavour PY 1992 VL 16 IS 1 BP 8 EP 13 DI 10.1016/0160-9327(92)90110-B PG 6 WC History & Philosophy Of Science; Multidisciplinary Sciences SC History & Philosophy of Science; Science & Technology - Other Topics GA HT542 UT WOS:A1992HT54200003 ER PT J AU BIDDIS, GT CORNETT, KG FRIMOUT, DD RICHARDS, ML AF BIDDIS, GT CORNETT, KG FRIMOUT, DD RICHARDS, ML TI A STEP TOWARDS SPACE-STATION USER OPERATIONS - AN OPERATIONAL TEST-BED SO ESA JOURNAL-EUROPEAN SPACE AGENCY LA English DT Article AB Within the framework of the Spacelab ATLAS-1 mission, the European Space Agency and the National Aeronautics and Space Administration have undertaken the definition and implementation of a basic remote-user-centre capability. This centre, located within the Columbus Crew Workstation facility, at ESTEC in Noordwijk (NL), should demonstrate the ability to monitor real-time payload operations remotely and allow some commanding and control functions through the Marshall Space Flight Center (MSFC) Payload Operations Control Center (POCC) in the USA. This paper provides an introduction to the project, and an account of some of the activities, as well as pitfalls, that have been experienced during its development. A follow-up article describing the mission operations will be published shortly after the ATLAS-1 mission. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,MISSION OPERAT LAB,HUNTSVILLE,AL 35812. EUROPEAN SPACE TECHNOL CTR,EUROPEAN SPACE AGCY,DEPT MICROGRAV & COLUMBUS UTILISAT,NOORDWIJK,NETHERLANDS. NEW TECHNOL INC,HUNTSVILLE,AL. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI NOORDWIJK PA ESTEC, PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-2285 J9 ESA J-EUR SPACE AGEN PY 1992 VL 16 IS 1 BP 35 EP 41 PG 7 WC Engineering, Aerospace SC Engineering GA HR630 UT WOS:A1992HR63000004 ER PT J AU FU, Y HALL, P AF FU, Y HALL, P TI NONLINEAR DEVELOPMENT AND SECONDARY INSTABILITY OF LARGE-AMPLITUDE GORTLER VORTICES IN HYPERSONIC BOUNDARY-LAYERS SO EUROPEAN JOURNAL OF MECHANICS B-FLUIDS LA English DT Article ID TIME-DEPENDENCE; 3-DIMENSIONALITY; BREAKDOWN; GROWTH; ONSET AB In a hypersonic boundary layer over a wall of variable curvature, the region most susceptible to Gortler vortices is the temperature adjustment layer over which the basic state temperature decreases monotonically to its free stream value [Hall & Fu, 19891; [Fu, Hall & Blackaby, 1992]. Except for a special wall curvature distribution, the evolution of Gortler vortices trapped in the temperature adjustment layer will in general be strongly affected by boundary layer growth. However, as the local wavenumber is increased, the latter effects will become increasingly less important. In this paper, we are concerned with Gortler vortices trapped in the temperature adjustment layer which have so large local wavenumbers that their downstream evolution are not affected by boundary layer growth within the order of approximation considered. We first present a weakly nonlinear theory in which the initial nonlinear development of Gortler vortices in the neighbourhood of the neutral position is investigated and two coupled evolution equations are derived. From these two evolution equations we can determine whether the vortices are decaying or growing depending on the sign of a constant which is related to the wall curvature and the basic state temperature. In the latter case, it is found that the mean flow correction becomes as large as the basic state at distances O (1) downstream of the neutral position. Next, we present a fully nonlinear theory concerning the further downstream development of these large-amplitude Gortler vortices. It is shown that the vortices spread out across the boundary layer. The upper and lower boundaries of the region of vortex activity are determined by a free-boundary problem involving the boundary layer equations, which is then solved numerically for a number of wall curvature cases and wall conditions. In particular, it is shown that wall cooling and gas dissociation may both considerably narrow the region of vortex activity. Finally, the secondary instability of the flow in the transition layers located at the upper and lower edges of the region of vortex activity is considered. The superimposed wavy vortex perturbations are spanwise periodic travelling waves which are pi/2 radians out of phase with the fundamental. The dispersion relation is found to be determined by solving two coupled differential equations and it is shown that an infinite number of neutrally stable modes may exist. C1 NASA,LANGLEY RES CTR,INST COMP APPLICAT SCI & ENGN,HAMPTON,VA 23665. RP FU, Y (reprint author), UNIV MANCHESTER,DEPT MATH,MANCHESTER M13 9PL,LANCS,ENGLAND. NR 18 TC 4 Z9 4 U1 0 U2 4 PU GAUTHIER-VILLARS PI PARIS PA S P E S-JOURNAL DEPT, 120 BD ST GERMAIN, F-75006 PARIS, FRANCE SN 0997-7546 J9 EUR J MECH B-FLUID JI Eur. J. Mech. B-Fluids PY 1992 VL 11 IS 4 BP 465 EP 510 PG 46 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA JH040 UT WOS:A1992JH04000006 ER PT J AU MCLEAN, DR PAGE, BJ TUCHMAN, A KISPERT, AV YEN, WL POTTER, WJ AF MCLEAN, DR PAGE, BJ TUCHMAN, A KISPERT, AV YEN, WL POTTER, WJ TI EMPHASIZING CONFLICT-RESOLUTION VERSUS CONFLICT AVOIDANCE DURING SCHEDULE GENERATION SO EXPERT SYSTEMS WITH APPLICATIONS LA English DT Article; Proceedings Paper CT 1ST WORLD CONGRESS ON EXPERT SYSTEMS CY DEC 16-19, 1991 CL ORLANDO, FL AB Classical planning systems attempt lo solve a planning problem by avoiding possible conflicts before the actions are put on a timeline. This is computationally very expensive and the search for all possible future conflicts may be prohibitive. A conflict revolution approach can check for immediate conflicts and try conflict resolution strategies as each activity is put on a timeline without regard for possible future conflicts. A more practical approach is to use a combination of conflict avoidance and conflict resolution based upon heuristics which limit the amount of search required when either is used. Because humans are not good at solving problems which require complex lookahead, this combined approach, with emphasis on conflict resolution, is what human schedulers actually use when they develop schedules. A system which simulates this human approach to scheduling has been developed at NASA's Goddard Space Flight Center for scheduling satellite activities. This system, which includes the Planning And Resource Reasoning (PARR) shell, allows expert schedulers to specify conflict resolution strategies as well as conflict avoidance strategies to be used during the scheduling process. PARR has been used since May 1987 to schedule the Tracking and Data Relay Satellite System services for the Earth Radiation Budget Satellite. PARR will also be used to schedule platform resources on the Explorer Platform, scheduled for launch in early 1992. This paper describes the advantages of using a combined conflict avoidance and resolution approach in a satellite scheduling system. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP MCLEAN, DR (reprint author), BENDIX FIELD ENGN CORP,10210 GREENBELT RD,SUITE 500,SEABROOK,MD 20706, USA. NR 12 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0957-4174 J9 EXPERT SYST APPL JI Expert Syst. Appl. PY 1992 VL 5 IS 3-4 BP 441 EP 446 DI 10.1016/0957-4174(92)90028-Q PG 6 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Operations Research & Management Science SC Computer Science; Engineering; Operations Research & Management Science GA JL894 UT WOS:A1992JL89400028 ER PT J AU DUKE, EL BRUMBAUGH, RW HEWETT, MD TARTT, DM AF DUKE, EL BRUMBAUGH, RW HEWETT, MD TARTT, DM TI FROM AN AUTOMATED FLIGHT-TEST MANAGEMENT-SYSTEM TO A FLIGHT-TEST ENGINEERS WORKSTATION SO EXPERT SYSTEMS WITH APPLICATIONS LA English DT Software Review RP DUKE, EL (reprint author), NATL AERONAUT & SPACE ADM,EDWARDS,CA, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0957-4174 J9 EXPERT SYST APPL JI Expert Syst. Appl. PY 1992 VL 4 IS 2 BP 267 EP 267 PG 1 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Operations Research & Management Science SC Computer Science; Engineering; Operations Research & Management Science GA HG384 UT WOS:A1992HG38400014 ER PT J AU STADLER, HL AF STADLER, HL TI FERROELECTRIC POLARIZATION REVERSAL IN SINGLE-CRYSTALS SO FERROELECTRICS LA English DT Article ID DOMAIN-STRUCTURE; TGS AB It is fitting that the present article should be part of a festschrift to Prof. Terutaro Nakamura. In 1965-66 when he hosted my stay in his lab at the University of Tokyo, he persuaded me to write a review which forms much of the present text. Prof. Nakamura translated it into Japanese for publication in the Proceedings of the Physical Society of Japan and it was never published in English until now. I have brought it up to date, adding recent references and some comments, but I have not tried to cover polarization reversal in ceramics or the new deposited ferroelectrics used in modern ferroelectric memories. It is a pleasure to acknowledge my many debts to Prof. Nakamura. RP STADLER, HL (reprint author), JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109, USA. NR 89 TC 9 Z9 9 U1 1 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0015-0193 J9 FERROELECTRICS PY 1992 VL 137 IS 1-4 BP 373 EP 387 DI 10.1080/00150199208015967 PG 15 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA KV311 UT WOS:A1992KV31100043 ER PT J AU THAKOOR, S AF THAKOOR, S TI HIGH-SPEED OPTOELECTRONIC NONDESTRUCTIVE READOUT FROM FERROELECTRIC THIN-FILM CAPACITORS SO FERROELECTRICS LA English DT Article; Proceedings Paper CT 2ND EUROPEAN CONF ON THE APPLICATION OF POLAR DIELECTRICS / 1ST INTERNATIONAL WORKSHOP ON INTEGRATED FERROELECTRICS CY APR 12-15, 1992 CL LONDON, ENGLAND SP DEF ADV RES PROJECTS AGCY, GORDON & BREACH SCI PUBL, DIELECT SOC, COOKSONS, GEC MARCONI MAT TECHNOL GRP AB Polarization dependent photoresponse from ferroelectric lead zirconate titanate (PbZr0.53Ti0.4703) thin films sandwiched between metal electrodes in a capacitor configuration is reported. This phenomenon has potential application as a non-destructive readout(NDRO) of nonvolatile polarization state of thin film ferroelectric memories. High speed readout using laser pulses with full width at half maximum of approximately 10ns, at 532 nm wavelength is demonstrated. The polarization direction of the ferroelectric capacitor is reflected in the direction of the photocurrent response. The rise time of the photocurrent response is as fast as 25 ns and the relaxation time is fraction of a microsecond. The readout signal from individual polarized elements is repeated over a million times with no detectable degradation in the photoresponse or the remanent polarization as verified independently by the conventional destructive readout technique. In principle, both electronic as well as thermal mechanisms could be triggered by such photon exposure of ferroelectric thin films. Comparison of the photoresponses from a device with a semitransparent top electrode and an opaque top electrode respectively suggests that the observed NDRO signal is predominantly due to thermally triggered mechanisms. RP THAKOOR, S (reprint author), JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109, USA. NR 20 TC 3 Z9 3 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0015-0193 J9 FERROELECTRICS PY 1992 VL 134 IS 1-4 BP 355 EP 363 DI 10.1080/00150199208015612 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA KG158 UT WOS:A1992KG15800058 ER PT B AU EGALON, CO ROGOWSKI, RS AF EGALON, CO ROGOWSKI, RS BE Claus, RO TI AXIAL STRAIN EFFECTS IN THE PHASE-SHIFT OF TE AND TM MODES OF AN OPTICAL-FIBER (EXACT SOLUTION) SO FIBER OPTIC SENSOR-BASED SMART MATERIALS AND STRUCTURES SE SMART MATERIALS AND STRUCTURES SERIES LA English DT Proceedings Paper CT 5th Annual Smart Materials and Structures Workshop CY APR 15-16, 1992 CL VIRGINIA TECH, FIBER & ELECTRO OPT RES CTR, BLACKSBURG, VA HO VIRGINIA TECH, FIBER & ELECTRO OPT RES CTR C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX BN 0-7503-0248-8 J9 SMAR MAT ST PY 1992 BP 73 EP 78 PG 6 WC Computer Science, Artificial Intelligence; Materials Science, Characterization & Testing; Optics SC Computer Science; Materials Science; Optics GA BA62T UT WOS:A1992BA62T00013 ER PT S AU HEIRTZLER, JR AF HEIRTZLER, JR BE Mendell, RB Mincer, AI TI FRONTIERS IN GEOMAGNETISM SO FRONTIERS IN COSMIC PHYSICS: SYMPOSIUM IN MEMORY OF SERGE ALEXANDER KORFF SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Proceedings Paper CT SYMP ON FRONTIERS IN COSMIC PHYSICS, IN MEMORY OF SERGE ALEXANDER KORFF CY SEP 13, 1990 CL NEW YORK, NY SP NYU, PHYS DEPT RP HEIRTZLER, JR (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NEW YORK ACAD SCIENCES PI NEW YORK PA NEW YORK SN 0077-8923 BN 0-89766-721-2 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1992 VL 655 BP 77 EP 85 DI 10.1111/j.1749-6632.1992.tb17066.x PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW52W UT WOS:A1992BW52W00015 ER PT S AU HOLT, SS AF HOLT, SS BE Mendell, RB Mincer, AI TI NEW FRONTIERS IN X-RAY ASTRONOMICAL SPECTROSCOPY SO FRONTIERS IN COSMIC PHYSICS: SYMPOSIUM IN MEMORY OF SERGE ALEXANDER KORFF SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Proceedings Paper CT SYMP ON FRONTIERS IN COSMIC PHYSICS, IN MEMORY OF SERGE ALEXANDER KORFF CY SEP 13, 1990 CL NEW YORK, NY SP NYU, PHYS DEPT RP HOLT, SS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,DIV SPACE SCI,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NEW YORK ACAD SCIENCES PI NEW YORK PA NEW YORK SN 0077-8923 BN 0-89766-721-2 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1992 VL 655 BP 263 EP 277 DI 10.1111/j.1749-6632.1992.tb17076.x PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW52W UT WOS:A1992BW52W00025 ER PT S AU FISHMAN, GJ AF FISHMAN, GJ BE Mendell, RB Mincer, AI TI GAMMA-RAY OBSERVATIONS OF THE CRAB PULSAR - PAST, PRESENT, FUTURE SO FRONTIERS IN COSMIC PHYSICS: SYMPOSIUM IN MEMORY OF SERGE ALEXANDER KORFF SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Editorial Material CT SYMP ON FRONTIERS IN COSMIC PHYSICS, IN MEMORY OF SERGE ALEXANDER KORFF CY SEP 13, 1990 CL NEW YORK, NY SP NYU, PHYS DEPT RP FISHMAN, GJ (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU NEW YORK ACAD SCIENCES PI NEW YORK PA NEW YORK SN 0077-8923 BN 0-89766-721-2 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1992 VL 655 BP 309 EP 318 DI 10.1111/j.1749-6632.1992.tb17079.x PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW52W UT WOS:A1992BW52W00028 ER PT S AU RAMATY, R LINGENFELTER, RE AF RAMATY, R LINGENFELTER, RE BE Mendell, RB Mincer, AI TI GALACTIC POSITRON-ANNIHILATION RADIATION SO FRONTIERS IN COSMIC PHYSICS: SYMPOSIUM IN MEMORY OF SERGE ALEXANDER KORFF SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Proceedings Paper CT SYMP ON FRONTIERS IN COSMIC PHYSICS, IN MEMORY OF SERGE ALEXANDER KORFF CY SEP 13, 1990 CL NEW YORK, NY SP NYU, PHYS DEPT RP RAMATY, R (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 NEW YORK ACAD SCIENCES PI NEW YORK PA NEW YORK SN 0077-8923 BN 0-89766-721-2 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1992 VL 655 BP 319 EP 325 DI 10.1111/j.1749-6632.1992.tb17080.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW52W UT WOS:A1992BW52W00029 ER PT B AU CHYBA, CF AF CHYBA, CF BE TranThanhVan, J TranThanhVan, K Mounolou, JC Schneider, J McKay, C TI THE VIOLENT ENVIRONMENT OF THE ORIGIN OF LIFE SO FRONTIERS OF LIFE LA English DT Proceedings Paper CT 3rd Blois Rencontre: Frontiers of Life CY OCT 14-19, 1991 CL CHATEAU DE BLOIS, FRANCE SP CNRS, MINIST RECH & TECHNOL FRANCE, CEA, NASA, INST ADV STUDIES BIOL, AGENCE SPATIALE EUROPEENNE, OBSERV PARIS MEUDON, CONSEIL REG REG CTR, CONSEIL GEN LOIR ET CHER, VILLE BLOIS C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 3 Z9 3 U1 0 U2 0 PU EDITIONS FRONTIERES PI DREUX PA 7 AVENUE KENNEDY, 28100 DREUX, FRANCE BN 2-86332-125-0 PY 1992 BP 97 EP 104 PG 8 WC Biology SC Life Sciences & Biomedicine - Other Topics GA BA82Z UT WOS:A1992BA82Z00007 ER PT B AU MCKAY, CP AF MCKAY, CP BE TranThanhVan, J TranThanhVan, K Mounolou, JC Schneider, J McKay, C TI LIFE IN THE SOLAR-SYSTEM SO FRONTIERS OF LIFE LA English DT Proceedings Paper CT 3rd Blois Rencontre: Frontiers of Life CY OCT 14-19, 1991 CL CHATEAU DE BLOIS, FRANCE SP CNRS, MINIST RECH & TECHNOL FRANCE, CEA, NASA, INST ADV STUDIES BIOL, AGENCE SPATIALE EUROPEENNE, OBSERV PARIS MEUDON, CONSEIL REG REG CTR, CONSEIL GEN LOIR ET CHER, VILLE BLOIS C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDITIONS FRONTIERES PI DREUX PA 7 AVENUE KENNEDY, 28100 DREUX, FRANCE BN 2-86332-125-0 PY 1992 BP 317 EP 325 PG 9 WC Biology SC Life Sciences & Biomedicine - Other Topics GA BA82Z UT WOS:A1992BA82Z00022 ER PT J AU TURNER, MS AF TURNER, MS TI THE TILTED UNIVERSE SO GENERAL RELATIVITY AND GRAVITATION LA English DT Article ID COSMIC BACKGROUND-RADIATION; LARGE-SCALE ANISOTROPY; ELLIPTICAL GALAXIES; SUPERGALACTIC CENTER; SPECTROSCOPY; PHOTOMETRY; MOTION; FLOW AB The simplest interpretation of the CMBR dipole anisotropy is that it arises due to our motion with respect to the cosmic rest frame. However, the existence of a superhorizon-sized isocurvature perturbation can give rise to a dipole anisotropy intrinsic to the CMBR. In this case the cosmic rest frame and the CMBR rest frame do not coincide, and when viewed from the CMBR rest frame the universe appears "tilted": matter streams uniformly from one side of the universe to the other. The intrinsic dipole model provides an explanation for the puzzling observation that most of the matter within a 100h-1 Mpc cube centered on our galaxy has a large velocity (of order 600 km s-1) with respect to the CMBR rest frame. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS & ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP TURNER, MS (reprint author), NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. NR 29 TC 4 Z9 4 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0001-7701 J9 GEN RELAT GRAVIT JI Gen. Relativ. Gravit. PD JAN PY 1992 VL 24 IS 1 BP 1 EP 7 DI 10.1007/BF00756869 PG 7 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA HA114 UT WOS:A1992HA11400001 ER PT J AU CABOT, W POLLACK, JB AF CABOT, W POLLACK, JB TI DIRECT NUMERICAL SIMULATIONS OF TURBULENT CONVECTION .2. VARIABLE GRAVITY AND DIFFERENTIAL ROTATION SO GEOPHYSICAL AND ASTROPHYSICAL FLUID DYNAMICS LA English DT Article DE CONVECTION; TURBULENCE; DIFFERENTIAL ROTATION; NUMERICAL INTEGRATION; SOLAR NEBULA ID PRIMORDIAL SOLAR NEBULA; ISOTROPIC TURBULENCE; FLOW; STABILITY; EVOLUTION C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP CABOT, W (reprint author), STANFORD UNIV,CTR TURBULENCE RES,STANFORD,CA 94305, USA. NR 22 TC 31 Z9 31 U1 0 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0309-1929 J9 GEOPHYS ASTRO FLUID JI Geophys. Astrophys. Fluid Dyn. PY 1992 VL 64 IS 1-4 BP 97 EP 133 DI 10.1080/03091929208228086 PG 37 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Mechanics SC Astronomy & Astrophysics; Geochemistry & Geophysics; Mechanics GA HY879 UT WOS:A1992HY87900004 ER PT J AU PREISIG, JR AF PREISIG, JR TI POLAR MOTION, ATMOSPHERIC ANGULAR-MOMENTUM EXCITATION AND EARTHQUAKES - CORRELATIONS AND SIGNIFICANCE SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE ATMOSPHERIC ANGULAR MOMENTUM; CHANDLER WOBBLE; EARTHQUAKES; KALMAN FILTERING; POLAR MOTION; VERY LONG BASE-LINE INTERFEROMETRY ID CHANDLER-WOBBLE; EARTHS WOBBLE; TIDE; DYNAMICS; LENGTH; OCEANS AB Equatorial atmospheric angular momentum (AAM) excitation functions and polar motion excitation functions (derived by Kalman filtering Very Long Baseline Interferometry polar motion estimates) are compared with the times of 1984-mid-1988 large earthquakes (magnitude greater than or equal to 7.5). There is a moderate correlation between times of large earthquakes and peaks in polar motion excitation. A strong correlation exists between the times of large earthquakes and large peaks in equatorial AAM amplitude; such a correlation is evident for six out of the eight large earthquakes occurring over the studied time interval. The AAM results indicate potential for the temporal prediction of large/great earthquakes. C1 NASA,GODDARD SPACE FLIGHT CTR,SPACE GEODESY BRANCH,TERR PHYS LAB,GREENBELT,MD 20771. NR 42 TC 10 Z9 10 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD JAN PY 1992 VL 108 IS 1 BP 161 EP 178 DI 10.1111/j.1365-246X.1992.tb00847.x PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA GX547 UT WOS:A1992GX54700013 ER PT B AU LEVINE, JS AF LEVINE, JS BE FIRTH, P FISHER, SG TI GLOBAL CLIMATE CHANGE SO GLOBAL CLIMATE CHANGE AND FRESHWATER ECOSYSTEMS LA English DT Proceedings Paper CT SYMP ON GLOBAL CLIMATE CHANGE AND FRESHWATER ECOSYSTEMS CY MAY 22, 1990 CL BLACKSBURG, VA SP NASA, US EPA, N AMER BENTHOL SOC RP LEVINE, JS (reprint author), NASA,LANGLEY RES CTR,DIV ATMOSPHER SCI,HAMPTON,VA 23665, USA. NR 0 TC 6 Z9 6 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA NEW YORK BN 0-387-97640-X PY 1992 BP 1 EP 25 PG 25 WC Ecology; Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA BV88N UT WOS:A1992BV88N00001 ER PT J AU LAUNIUS, RD AF LAUNIUS, RD TI WORLDWIDE SCIENCE AND TECHNOLOGY ADVICE TO THE HIGHEST LEVELS OF GOVERNMENTS - GOLDEN,WT SO GOVERNMENT PUBLICATIONS REVIEW LA English DT Book Review RP LAUNIUS, RD (reprint author), NASA HEADQUARTERS,DIV HIST ADA-2,WASHINGTON,DC 20546, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0277-9390 J9 GOV PUBL REV PD JAN-FEB PY 1992 VL 19 IS 1 BP 90 EP 91 DI 10.1016/0277-9390(92)90117-T PG 2 WC Information Science & Library Science SC Information Science & Library Science GA HF480 UT WOS:A1992HF48000012 ER PT J AU AGRESTI, DG MORRIS, RV WILLS, EL SHELFER, TD PIMPERL, MM SHEN, MH CLARK, BC RAMSEY, BD AF AGRESTI, DG MORRIS, RV WILLS, EL SHELFER, TD PIMPERL, MM SHEN, MH CLARK, BC RAMSEY, BD TI EXTRATERRESTRIAL MOSSBAUER SPECTROMETRY SO HYPERFINE INTERACTIONS LA English DT Article; Proceedings Paper CT INTERNATIONAL WORKSHOP ON NUCLEAR ZEEMAN EFFECT AND RECENT ADVANCES IN MOSSBAUER SPECTROSCOPY, IN HONOR OF PROFESSOR STANLEY S. HANNA CY MAR 15, 1991 CL STANFORD UNIV, STANFORD, CA SP DUPONT MERCK, AMERSHAM, APD CRYOGENICS, CANBERRA IND HO STANFORD UNIV ID MAGNETIC-PROPERTIES; MARS; MINERALOGY; EVOLUTION; RELEVANCE; HEMATITE; SOILS AB We describe a combined backscatter Mossbauer spectrometer and X-ray fluorescence analyzer (BaMS/XRF) instrument suitable for planetary missions to the surfaces of Mars (MESUR Program), the Moon, asteroids, or other solid solar-system objects. The BaMS/XRF instrument is designed to be capable of concurrent analysis of a sample for its elemental abundances (XRF) and for the mineralogy of its iron-bearing phases (BaMS) without any sample preparation. C1 MARTIN MARIETTA AEROSP CO,DENVER,CO 80201. NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP AGRESTI, DG (reprint author), UNIV ALABAMA,DEPT PHYS,BIRMINGHAM,AL 35294, USA. NR 34 TC 10 Z9 10 U1 0 U2 1 PU BALTZER SCI PUBL BV PI AMSTERDAM PA ASTERWEG 1A, 1031 HL AMSTERDAM, NETHERLANDS SN 0304-3843 J9 HYPERFINE INTERACT JI Hyperfine Interact. PY 1992 VL 72 IS 1-3 BP 285 EP 298 PG 14 WC Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Physics, Nuclear SC Physics GA JA840 UT WOS:A1992JA84000023 ER PT J AU ALLAMANDOLA, LJ AF ALLAMANDOLA, LJ TI ISO AND LABORATORY ASTROPHYSICS SO IAU SYMPOSIA LA English DT Article RP ALLAMANDOLA, LJ (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 15 EP 16 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800004 ER PT J AU SALAMA, F ALLAMANDOLA, LJ AF SALAMA, F ALLAMANDOLA, LJ TI UV-VISIBLE AND NEAR IR ABSORPTION CHARACTERISTICS OF INTERSTELLAR PAHS .1. C10H8+ SO IAU SYMPOSIA LA English DT Article AB We have initiated a systematic and detailed study of the spectroscopy of neutral and ionized Polycyclic Aromatic Hydrocarbons (PAHs). We report here, the results obtained for the smallest PAH (C10H8) [1] and discuss their astrophysical applications. RP SALAMA, F (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MS 245-6, MOFFETT FIELD, CA 94035 USA. RI Salama, Farid/A-8787-2009 OI Salama, Farid/0000-0002-6064-4401 NR 2 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 25 EP 26 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800009 ER PT J AU HUDGINS, DM SANDFORD, SA TIELENS, AGGM ALLAMANDOLA, LJ AF HUDGINS, DM SANDFORD, SA TIELENS, AGGM ALLAMANDOLA, LJ TI INFRARED-SPECTROSCOPY OF INTERSTELLAR AND SOLAR-SYSTEM ICE ANALOGS - MEASUREMENT OF OPTICAL-CONSTANTS SO IAU SYMPOSIA LA English DT Article AB Laboratory spectra through the mid-infrared have been used to calculate the optical constants (n and k) for a variety of pure and mixed molecular ices. The ices studied were H2O, CH3OH, CO2, OCS, CH4, CO2+CH4, CO2+OCS, CO+CH4, CO+OCS, O2+CH4, O2+OCS, N2+CH4, N2+OCS, H2O+CH4, H2O+OCS, and H2O+CH3OH+CO+NH3. RP HUDGINS, DM (reprint author), NASA, AMES RES CTR, MS 245-6, MOFFETT FIELD, CA 94035 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 27 EP 28 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800010 ER PT J AU SCHUTTE, WA ALLAMANDOLA, LJ SANDFORD, SA AF SCHUTTE, WA ALLAMANDOLA, LJ SANDFORD, SA TI FORMATION OF ORGANIC-MOLECULES BY FORMALDEHYDE REACTIONS IN ASTROPHYSICAL ICES AT VERY LOW-TEMPERATURES SO IAU SYMPOSIA LA English DT Article AB Warm-up of astrophysical ice analogues containing formaldehyde produced organic residues in large abundances. It is argued that formaldehyde reactions at very low temperatures could be an important source of interstellar and cometary organic molecules. RP SCHUTTE, WA (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MS 245-6, MOFFETT FIELD, CA 94035 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 29 EP 30 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800011 ER PT J AU NUTH, JA AF NUTH, JA TI METAMORPHISM OF COSMIC DUST - DIAGNOSTIC INFRARED SIGNATURES SO IAU SYMPOSIA LA English DT Article RP NUTH, JA (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ASTROCHEM BRANCH, CODE 691, GREENBELT, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 39 EP 40 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800013 ER PT J AU CARPENTER, KG AF CARPENTER, KG TI ZETA-AURIGAE TYPE BINARIES SO IAU SYMPOSIA LA English DT Article DE STARS-ECLIPSING BINARIES; STARS-CHROMOSPHERES; STARS-LATE-TYPE; STARS-WINDS ID VV CEPHEI SYSTEMS; ULTRAVIOLET-SPECTRA; UV SPECTRA; OPTICAL-SPECTRA; LINE FORMATION; MASS-LOSS; WIND; ECLIPSE; CHROMOSPHERE; SUPERGIANTS AB Recent progress in the study of zeta-Aur and VV Cep systems is reviewed, with an emphasis on what has been learned about the extended atmospheres and winds around the cooler components. C1 NASA, GODDARD SPACE FLIGHT CTR, ASTRON & SOLAR PHYS LAB, GREENBELT, MD 20771 USA. NR 38 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 151 BP 51 EP 59 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JJ251 UT WOS:A1992JJ25100006 ER PT J AU BORDERIES, N AF BORDERIES, N TI LOOKING FOR CHANGES IN THE SATURNIAN SYSTEM BETWEEN VOYAGER AND CASSINI SO IAU SYMPOSIA LA English DT Article DE PLANETARY RINGS DYNAMICS ID SPIRAL DENSITY WAVES; PLANETARY RINGS; URANIAN RINGS; ENCKE GAP; SHARP EDGES; SATELLITES; OCCULTATION; ECCENTRICITIES; IDENTIFICATION; PRECESSION AB This paper reviews a number of time-dependent phenomens that are relevant to our understanding of the dynamics of planetary rings and that will be investigated using Voyager and Cassini data. A long time baseline may help us decipher the physics of the spokes, understand better the morphology of the F ring and the rigid precession of non-circular ringlets, measure more precisely than has been done so far the satellites' torques and the viscosity of the A ring, and discover small satellites in the Saturnian ring system. Two exciting possibilities are those of determining the recession rates of the small satellites that border the rings, and of observing changes due to viscous diffusion in the irregular structures of the B ring. RP BORDERIES, N (reprint author), JET PROPULS LAB 301-150,PASADENA,CA 91109, USA. NR 58 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 152 BP 53 EP 64 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JJ252 UT WOS:A1992JJ25200009 ER PT J AU ALLAMANDOLA, LJ AF ALLAMANDOLA, LJ TI GRAIN SPECTROSCOPY SO IAU SYMPOSIA LA English DT Article ID ABSORPTION FEATURES; GALACTIC-CENTER; MICRON ABSORPTION; INFRARED-EMISSION; MOLECULAR CLOUDS; DUST; ICE; CO; SPECTROPOLARIMETRY; PROTOSTARS RP ALLAMANDOLA, LJ (reprint author), NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NR 59 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 65 EP 72 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800017 ER PT J AU TIELENS, AGGM AF TIELENS, AGGM TI THE D/H RATIO IN MOLECULAR CLOUDS SO IAU SYMPOSIA LA English DT Article ID DEUTERIUM FRACTIONATION; INTERSTELLAR CLOUDS AB This paper summarizes our understanding of the dominant D-reservoirs in molecular clouds and suggests possible direct determinations of die D-abundance. It is concluded that rotational HD lines from shock regions provide the best way to determine the gas phase D-abundance. In cold dense cores, die dominant gas phase D-reservoir is likely to be atomic D, because of expected inefficient HD formation on grain surfaces. The gas phase D-abundance derived from observations of dense cores is almost-equal-to 5x10(-6)/n4 (with n4 the total density in units of 10(4) cm-3). A large fraction of the D (almost-equal-to 50%) may be locked up in deuterated molecules in grain mantles. A small fraction (almost-equal-to 2%) may be locked up in the photolyzed residues of such grain mantles. PAHs will also be deuterated (PADs), containing almost-equal-to 1 % of the D. Finally, it is likely that all of these processes have contributed to the D-enrichment observed in solar system materials. RP TIELENS, AGGM (reprint author), NASA, AMES RES CTR, MS 245-3, MOFFETT FIELD, CA 94035 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 91 EP 95 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800021 ER PT J AU SANDFORD, SA ALLAMANDOLA, LJ TIELENS, AGGM SELLGREN, K TAPIA, M PENDLETON, Y AF SANDFORD, SA ALLAMANDOLA, LJ TIELENS, AGGM SELLGREN, K TAPIA, M PENDLETON, Y TI THE INTERSTELLAR C-H STRETCHING BAND NEAR 3.4-MU-M - CONSTRAINTS ON THE COMPOSITION OF ORGANIC MATERIAL IN THE DIFFUSE ISM SO IAU SYMPOSIA LA English DT Article AB The spectra of objects suffering extinction by diffuse interstellar dust contain a broad feature centered at approximately 3300 cm-1 (approximately 3.0 mum), attributed to O-H stretching vibrations, and/or a feature near 2950 cm-1 (3.4 mum) attributed to C-H stretching vibrations. The 2950 cm-1 feature can be attributed to C-H stretching vibrations in the -CH2- and -CH3 groups of a fairly complex carbonaceous material containing aliphatic functional groups. C1 UNIV NACL AUTONOMA MEXICO, INST ASTRON, ENSENADA, MEXICO. OHIO STATE UNIV, DEPT ASTRON, COLUMBUS, OH 43210 USA. RP SANDFORD, SA (reprint author), NASA, AMES RES CTR, MS 245-6, MOFFETT FIELD, CA 94035 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 133 EP 134 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800029 ER PT J AU SCHUTTE, WA TIELENS, AGGM ALLAMANDOLA, LJ AF SCHUTTE, WA TIELENS, AGGM ALLAMANDOLA, LJ TI THEORETICAL MODELING OF THE INFRARED FLUORESCENCE BY INTERSTELLAR POLYCYCLIC AROMATIC-HYDROCARBONS SO IAU SYMPOSIA LA English DT Article AB We modelled the IR emission of interstellar PAHs. Substantial differences between the IR properties of interstellar and laboratory PAHs are found, possibly resulting from ionization. The various IR features being dominated by distinctly different size PAHs, their observed relative intensities are sensitive indicators of the size distribution. A number of applications of our model related to future ISO and SIRTF IR data are pointed out. RP SCHUTTE, WA (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MS 245-6, MOFFETT FIELD, CA 94035 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 137 EP 138 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800031 ER PT J AU CHARNLEY, SB ROBERGE, WG AF CHARNLEY, SB ROBERGE, WG TI CHEMICAL EFFECTS OF SHEAR ALFVEN WAVES IN MOLECULAR CLOUDS SO IAU SYMPOSIA LA English DT Article ID INTERSTELLAR CLOUDS; FRACTIONATION; IONIZATION; DEUTERIUM AB We consider the propagation of low-amplitude MHD waves in partially-ionised plasmas. Ion-neutral drift (ambipolar diffusion) can lead to significant variations in the deuterium fractionation ratios of several molecules (e.g. HCO+ and N2H+) on spatial scales of between a few hundredths and a few tenths of a parsec, depending upon the fractional ionisation of the plasma. It is possible that interstellar Alfven waves could be detected by molecular spectroscopy and that these waves may produce other small-scale abundance gradients in molecular clouds. C1 RENSSELAER POLYTECH INST, DEPT PHYS, TROY, NY 12180 USA. RP CHARNLEY, SB (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MOFFETT FIELD, CA 94035 USA. RI Charnley, Steven/C-9538-2012 NR 10 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 155 EP 156 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800035 ER PT J AU BUTNER, HM AF BUTNER, HM TI ABUNDANCE OF DCO+ IN NEARBY MOLECULAR CLOUDS SO IAU SYMPOSIA LA English DT Article ID DENSE INTERSTELLAR CLOUDS; INTER-STELLAR CLOUDS; DEUTERIUM FRACTIONATION; NH3 OBSERVATIONS; DARK CLOUDS; TEMPERATURE; CORES AB DCO+ is one of the most common deuterated molecules in cold (T(K) approximately 10 K) molecular cloud cores such as TMC-1. We report the results of a survey for DCO+ and (HCO+)-C-13 emission regions among a sample of low mass cloud cores. We compare the derived DCO+/HCO+ ratio (0.046 +/- 0.014) with current chemistry models for deuterium fractionation RP BUTNER, HM (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MOFFETT FIELD, CA 94035 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 169 EP 170 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800038 ER PT J AU SNYDER, LE HOLLIS, JM ZIURYS, LM KUAN, YJ AF SNYDER, LE HOLLIS, JM ZIURYS, LM KUAN, YJ TI OBSERVATIONS OF HNO SO IAU SYMPOSIA LA English DT Article AB Interferometric observations of the HNO 3.68 mm line in Sgr B2 show clumping and some distribution similarities with HNCO. A search for the HNO 1.23 mm line with the NRAO 12-m telescope was unsuccessful. C1 NASA, GODDARD SPACE FLIGHT CTR, DIV SPACE DATA & COMP, GREENBELT, MD 20771 USA. ARIZONA STATE UNIV, DEPT CHEM, TEMPE, AZ 85287 USA. RP SNYDER, LE (reprint author), UNIV ILLINOIS, DEPT ASTRON, CHAMPAIGN, IL 61820 USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 187 EP 188 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800042 ER PT J AU LANGER, WD AF LANGER, WD TI CARBON ISOTOPIC CHEMISTRY SO IAU SYMPOSIA LA English DT Article ID DENSE INTERSTELLAR CLOUDS; ZETA-OPHIUCHI; RATIO AB Isotopic molecular abundances are used to interpret Galactic chemical evolution and the properties of interstellar clouds. The isotopic chemistry of carbon plays an important role in the interpretation of these measurements. This paper reviews the recent measurements of the carbon twelve to thirteen ratio across the Galaxy and the isotopic chemistry. RP LANGER, WD (reprint author), JET PROP LAB, MS 169-506, PASADENA, CA 91109 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 193 EP 197 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800045 ER PT J AU CHARNLEY, SB AF CHARNLEY, SB TI CHEMICAL-MODELS OF ACTIVE REGIONS SO IAU SYMPOSIA LA English DT Article ID DENSE INTERSTELLAR CLOUDS; MOLECULAR CLOUDS; ASTRONOMICAL FLOWS; STAR FORMATION; SHOCK-WAVES; DARK CLOUD; CHEMISTRY; BARNARD-5; ANATOMY; TMC-1 AB Theoretical models of the chemistry in regions of low-mass star formation are reviewed. RP CHARNLEY, SB (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MOFFETT FIELD, CA 94035 USA. RI Charnley, Steven/C-9538-2012 NR 31 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 199 EP 203 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800046 ER PT J AU EGGLETON, PP KOCH, RH KONDO, Y POPPER, DM SMAK, JI WOOD, FB AF EGGLETON, PP KOCH, RH KONDO, Y POPPER, DM SMAK, JI WOOD, FB TI UNSOLVED MAJOR PROBLEMS OF INTERACTING BINARIES - A PANEL DISCUSSION SO IAU SYMPOSIA LA English DT Discussion C1 UNIV PENN, DEPT ASTRON & ASTROPHYS, PHILADELPHIA, PA 19003 USA. NICHOLAS COPERNICUS ASTRON CTR, PL-00716 WARSAW, POLAND. UNIV CALIF LOS ANGELES, DEPT ASTRON, LOS ANGELES, CA 90024 USA. NASA, GODDARD SPACE FLIGHT CTR, ASTRON & SOLAR PHYS LAB, GREENBELT, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 151 BP 255 EP 264 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JJ251 UT WOS:A1992JJ25100026 ER PT J AU RUBIN, RH ERICKSON, EF HAAS, MR COLGAN, SWJ SIMPSON, JP DUFOUR, RJ AF RUBIN, RH ERICKSON, EF HAAS, MR COLGAN, SWJ SIMPSON, JP DUFOUR, RJ TI ABUNDANCES OF REFRACTORY ELEMENTS IN THE ORION NEBULA SO IAU SYMPOSIA LA English DT Article ID SILICON; IRON; GAS; IUE AB We assess the gas-phase abundances of Si, C, and Fe from our recent measurements of Si++, C++, and Fe++ in the Orion Nebula by expanding on our earlier "blister" models. The Fe++ 22.9 mum line measured with the KAO yields Fe/H approximately 3 x 10(-6) - considerably larger than in the diffuse ISM, where relative to solar, Fe/H is down by approximately 100. However, in Orion, Fe/H is still lower than solar by a factor approximately 10. The C and Si abundances are derived from new IUE high dispersion spectra of the C++ 1907, 1909 angstrom and Si++ 1883, 1892 angstrom lines. Gas-phase Si/C = 0.016 in the Orion ionized volume and is particularly insensitive to uncertainties in extinction and temperature structure. The solar value is 0.098. Gas-phase C/H = 3 x 10(-4) and Si/H = 4.8 x 10(-6). Compared to solar, Si is depleted by 0.135 in the ionized region, while C is essentially undepleted. This suggests that most Si and Fe resides in dust grains even in the ionized volume. C1 RICE UNIV, DEPT SPACE PHYS & ASTRON, HOUSTON, TX 77251 USA. RP RUBIN, RH (reprint author), NASA, AMES RES CTR, MS 245-6, MOFFETT FIELD, CA 94035 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 281 EP 283 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800063 ER PT J AU VANDISHOECK, EF GLASSGOLD, AE GUELIN, M JAFFE, DT NEUFELD, DA TIELENS, AGGM WALMSLEY, CM AF VANDISHOECK, EF GLASSGOLD, AE GUELIN, M JAFFE, DT NEUFELD, DA TIELENS, AGGM WALMSLEY, CM TI PANEL DISCUSSION - THE CO/H2 ABUNDANCE RATIO SO IAU SYMPOSIA LA English DT Article ID INTERSTELLAR ABSORPTION-LINES; INFRARED-EMISSION; MOLECULAR CLOUDS; PHOTODISSOCIATION REGIONS; CARBON-MONOXIDE; EVOLVED STARS; CO; SPECTRUM; GALAXY; SHOCKS AB The observational and theoretical information on the CO/H-2 abundance in a variety of astrophysical regions including diffuse clouds, dense star-forming regions, shocked gas and circumstellar envelopes is discussed and reviewed. C1 NYU, DEPT PHYS, NEW YORK, NY 10003 USA. UNIV GRENOBLE, IRAM, F-38406 ST MARTIN DHERES, FRANCE. UNIV TEXAS, DEPT ASTRON, AUSTIN, TX 78712 USA. MPI RADIOASTRON, W-5300 BONN 1, GERMANY. JOHNS HOPKINS UNIV, DEPT ASTRON, BALTIMORE, MD 21218 USA. NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. RP VANDISHOECK, EF (reprint author), LEIDEN UNIV, POB 9513, 2300 RA LEIDEN, NETHERLANDS. NR 64 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 285 EP 295 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800064 ER PT J AU CHARNLEY, SB TIELENS, AGGM AF CHARNLEY, SB TIELENS, AGGM TI HOT CORE CHEMISTRY - GAS-PHASE MOLECULE FORMATION INSITU SO IAU SYMPOSIA LA English DT Article ID CLOUDS AB The possibility that the observed abundances of several molecules in the Orion Hot Core are due to gas phase neutral chemistry has been examined. RP CHARNLEY, SB (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MOFFETT FIELD, CA 94035 USA. RI Charnley, Steven/C-9538-2012 NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 317 EP 318 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800069 ER PT J AU SAHADE, J BARBA, R KONDO, Y AF SAHADE, J BARBA, R KONDO, Y TI THE ORBITAL PARAMETERS AND THE IUE SPECTRUM OF THE SINGLE-LINED SPECTROSCOPIC BINARY HD-698 SO IAU SYMPOSIA LA English DT Meeting Abstract C1 OBSERV ASTRON, RA-1900 LA PLATA, ARGENTINA. INST ARGENTINO RADIOASTRON, RA-1894 VILLA ELISA, ARGENTINA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 151 BP 319 EP 319 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JJ251 UT WOS:A1992JJ25100038 ER PT J AU POLIDAN, RS WADE, RA AF POLIDAN, RS WADE, RA TI OBSERVATIONS OF CNO PROCESSED MATTER IN MASSIVE INTERACTING BINARY-SYSTEMS SO IAU SYMPOSIA LA English DT Article AB Ultraviolet observations for nine massive Algol systems (DH Her, TU Mon, AU Mon, Z Ori, RY Per, IZ Per, V356 Sgr, RZ Sct and ET Tau) obtained during their primary eclipses with the IUE spacecraft are discussed. Four systems, AU Mon, Z Ori, IZ Per, and RZ Sct, yielded no useful data on the presence of UV emission lines. Four binary systems DH Her, TU Mon, RY Per, and V356 Sgr, displayed a prominent emission spectrum with the notable exception of carbon lines; only one of the studied systems, ET Tau, showed carbon emission. Analysis of these data strongly supports the suggestion that the lack of carbon emission lines in these systems is the product of an inherent carbon deficiency in the transferred material and not due to any ionization effects in the gas. This carbon deficiency is the result of the CNO processed layers of the secondary being exposed as a result of mass transfer. The IUE data on TU Mon also indicates that this system undergoes a total, rather than partial, eclipse. C1 NASA, GODDARD SPACE FLIGHT CTR, ASTRON & SOLAR PHYS LAB, GREENBELT, MD 20771 USA. PENN STATE UNIV, DEPT ASTRON & ASTROPHYS, DAVEY LAB 525, UNIV PK, PA 16802 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 151 BP 351 EP 354 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JJ251 UT WOS:A1992JJ25100046 ER PT J AU SHORE, SN CORCORAN, MJ AF SHORE, SN CORCORAN, MJ TI COLLIDING STELLAR WINDS IN CLOSE BINARY-SYSTEMS SO IAU SYMPOSIA LA English DT Article DE STELLAR WINDS; HYDRODYNAMICS; ULTRAVIOLET SPECTROSCOPY ID COLLISION AB We describe some of the observational phenomena associated with colliding stellar winds, focussing especially on close WR+O binaries. In particular, we report some new ultraviolet observations of CQ Cep and V444 Cyg. We also discuss some of the general theory of such wind collisions. C1 NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTRON LAB, GREENBELT, MD 20771 USA. NASA, GODDARD SPACE FLIGHT CTR, GHRS SCI TEAM, CSC, GREENBELT, MD 20771 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 151 BP 359 EP 362 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JJ251 UT WOS:A1992JJ25100048 ER PT J AU HUENEMOERDER, DP RAMSEY, LW BUZASI, DL NATIONS, HL AF HUENEMOERDER, DP RAMSEY, LW BUZASI, DL NATIONS, HL TI FK-COMAE AND THE EVOLUTION OF CLOSE BINARIES SO IAU SYMPOSIA LA English DT Article ID GIANT AB FK Com is an enigma among active cool stars. A rotationally driven magnetic dynamo is an explanation for activity. Youth and binarity are two causes of rapid rotation, but FK Com is old, single, and rotating new breakup. Much studied optical and ultraviolet data have not revealed the cause of its unusual activity. It is an important object in a more complete understanding of close binary star evolution and of the dynamo theory of magnetic activity. In 1989, we executed a coordinated ultraviolet and intensive optical spectroscopic and photometric campaign to better elucidate its characteristics. Data relevant to its evolutionary status, namely its radial velocity variations, will be discussed here, while an in depth study of the chromospheric activity will be deferred to a more detailed publication. C1 JET PROP LAB, PASADENA, CA 91109 USA. PENN STATE UNIV, UNIV PK, PA 16802 USA. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. FRANKLIN & MARSHALL COLL, LANCASTER, PA 17604 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 151 BP 403 EP 406 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JJ251 UT WOS:A1992JJ25100057 ER PT J AU SALAMA, F SANDFORD, SA ALLAMANDOLA, LJ AF SALAMA, F SANDFORD, SA ALLAMANDOLA, LJ TI LABORATORY STUDIES OF PLANETARY MOLECULES AND ICES - THE CASE OF IO SO IAU SYMPOSIA LA English DT Article ID SPECTRUM AB The techniques of low temperature spectroscopy are applied here to analyze infrared observational data of Io in the 2.0-5.0 mum range. The presence of solid H2S and traces of H2O in the SO2-dominant surface ices are derived from this analysis and it is suggested that CO2 clusters may as well be present near the surface of Io. RP SALAMA, F (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MS 245-6, MOFFETT FIELD, CA 94035 USA. RI Salama, Farid/A-8787-2009 OI Salama, Farid/0000-0002-6064-4401 NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 435 EP 436 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800105 ER PT J AU BLAKE, DF ALLAMANDOLA, L FREUND, F SANDFORD, S HUDGINS, D AF BLAKE, DF ALLAMANDOLA, L FREUND, F SANDFORD, S HUDGINS, D TI TYPE-II CLATHRATE HYDRATE FORMATION IN COMETARY ICE ANALOGS IN VACUO SO IAU SYMPOSIA LA English DT Article ID PHYSICO-CHEMICAL PHENOMENA; OXIRANE; SNOWS AB Clathrate Hydrates can be formed under high vacuum conditions by annealing vapor-deposited amorphous ices of the appropriate composition. When astrophysically significant H2O:CH3OH ices are deposited and annealed, Type II Clathrate Hydrates are formed which can hold up to 6 mole % large guest molecules such as methanol and 12 mole % small guest molecules such as CO2 and CO. The solid state transformation of amorphous mixed molecular ice into crystalline clathrate hydrate and its sublimation at higher temperatures may serve to explain heretofore anomalous mechanical and gas release properties observed in cometary ices and laboratory ice analog experiments. C1 SAN JOSE STATE UNIV, DEPT PHYS, SAN JOSE, CA 95192 USA. RP BLAKE, DF (reprint author), NASA, AMES RES CTR, MS 239-4, MOFFETT FIELD, CA 94035 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 437 EP 438 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800106 ER PT J AU NUTH, JA AF NUTH, JA TI A DIAGNOSTIC SPECTRAL INDICATOR OF THE EXPOSURE AGE OF AN ASTEROIDAL SURFACE SO IAU SYMPOSIA LA English DT Article RP NUTH, JA (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ASTROCHEM BRANCH, CODE 691, GREENBELT, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1992 IS 150 BP 461 EP 462 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA JQ128 UT WOS:A1992JQ12800114 ER PT J AU ZAHNLE, K POLLACK, JB GRINSPOON, D DONES, L AF ZAHNLE, K POLLACK, JB GRINSPOON, D DONES, L TI IMPACT-GENERATED ATMOSPHERES OVER TITAN, GANYMEDE, AND CALLISTO SO ICARUS LA English DT Article ID SHORT-PERIOD COMETS; SOLAR-SYSTEM; EROSION; BOMBARDMENT; DELIVERY; ORIGIN; RATIO C1 CANADIAN INST THEORET ASTROPHYS,TORONTO,ONTARIO,CANADA. RP ZAHNLE, K (reprint author), NASA,AMES RES CTR,MS 245 3,MOFFETT FIELD,CA 94035, USA. NR 45 TC 57 Z9 57 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1992 VL 95 IS 1 BP 1 EP 23 DI 10.1016/0019-1035(92)90187-C PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HF734 UT WOS:A1992HF73400001 PM 11538396 ER PT J AU TOON, OB MCKAY, CP GRIFFITH, CA TURCO, RP AF TOON, OB MCKAY, CP GRIFFITH, CA TURCO, RP TI A PHYSICAL MODEL OF TITANS AEROSOLS SO ICARUS LA English DT Article ID INFRARED OBSERVATIONS; VERTICAL-DISTRIBUTION; OPTICAL-PROPERTIES; ATMOSPHERE; SCATTERING; PHOTOCHEMISTRY; NEPTUNE; URANUS; VOYAGER-1 C1 SUNY STONY BROOK,DEPT EARTH & SPACE SCI,STONY BROOK,NY 11794. UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,LOS ANGELES,CA 90024. RP TOON, OB (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 41 TC 125 Z9 125 U1 0 U2 8 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1992 VL 95 IS 1 BP 24 EP 53 DI 10.1016/0019-1035(92)90188-D PG 30 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HF734 UT WOS:A1992HF73400002 PM 11538397 ER PT J AU KLAVETTER, JJ HOBAN, S AF KLAVETTER, JJ HOBAN, S TI IMAGING THE 3.4-MU-M FEATURE IN COMET LEVY (1990C) SO ICARUS LA English DT Article ID IKS-VEGA EXPERIMENT; ORGANIC GRAINS; MU-M; HALLEY; P/HALLEY; SPECTROSCOPY; CALIBRATION; DISCOVERY; SPECTRUM; WILSON C1 NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,PLANETARY SYST BRANCH,GREENBELT,MD 20771. RP KLAVETTER, JJ (reprint author), UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742, USA. NR 20 TC 4 Z9 4 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1992 VL 95 IS 1 BP 60 EP 64 DI 10.1016/0019-1035(92)90190-I PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HF734 UT WOS:A1992HF73400004 ER PT J AU HARRIS, AW YOUNG, JW DOCKWEILER, T GIBSON, J POUTANEN, M BOWELL, E AF HARRIS, AW YOUNG, JW DOCKWEILER, T GIBSON, J POUTANEN, M BOWELL, E TI ASTEROID LIGHTCURVE OBSERVATIONS FROM 1981 SO ICARUS LA English DT Article ID MAIN-BELT ASTEROIDS; PHOTOELECTRIC PHOTOMETRY; GEODESY; ROTATION C1 LOWELL OBSERV,FLAGSTAFF,AZ 86001. RP HARRIS, AW (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. RI Dockweiler, Thor/H-4866-2016 OI Dockweiler, Thor/0000-0001-5431-0029 NR 38 TC 47 Z9 47 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD JAN PY 1992 VL 95 IS 1 BP 115 EP 147 DI 10.1016/0019-1035(92)90195-D PG 33 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HF734 UT WOS:A1992HF73400009 ER PT B AU BAILEY, FR DWOYER, DL NICHOLS, LD AF BAILEY, FR DWOYER, DL NICHOLS, LD GP INT COUNCIL AERONAUT SCI TI THE NEW CHALLENGE OF COMPUTATIONAL AEROSCIENCE SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 83 EP 96 PG 14 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00018 ER PT B AU SOBIESZCZANSKISOBIESKI, J AF SOBIESZCZANSKISOBIESKI, J GP INT COUNCIL AERONAUT SCI TI AIRCRAFT OPTIMIZATION BY A SYSTEM APPROACH - ACHIEVEMENTS AND TRENDS SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 394 EP 407 PG 14 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00056 ER PT B AU WILSON, JW NEALY, JE AF WILSON, JW NEALY, JE GP INT COUNCIL AERONAUT SCI TI RADIATION SAFETY IN AIRCRAFT OPERATIONS SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,LANGLEY RES CTR,DIV SPACE SYST,HAMPTON,VA 23665. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 541 EP 552 PG 12 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00072 ER PT B AU ABEL, I AF ABEL, I GP INT COUNCIL AERONAUT SCI TI RESEARCH AND APPLICATIONS IN STRUCTURAL DYNAMICS AND AEROELASTICITY SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 557 EP 570 PG 14 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00074 ER PT B AU EXTON, RJ AF EXTON, RJ GP INT COUNCIL AERONAUT SCI TI NONINTRUSIVE SPECTROSCOPIC TECHNIQUES FOR SUPERSONIC HYPERSONIC AERODYNAMICS AND COMBUSTION DIAGNOSTICS SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,LANGLEY RES CTR,DIV INSTRUMENT RES,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 722 EP 727 PG 6 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00096 ER PT B AU NEWMAN, JC WU, XR SWAIN, MH ZHAO, W PHILLIPS, EP DING, CF AF NEWMAN, JC WU, XR SWAIN, MH ZHAO, W PHILLIPS, EP DING, CF GP INT COUNCIL AERONAUT SCI TI SMALL-CRACK GROWTH-BEHAVIOR IN HIGH-STRENGTH ALUMINUM-ALLOYS - A NASA/CAE COOPERATIVE PROGRAM SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 799 EP 820 PG 22 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00106 ER PT B AU GRAY, CE MEI, C AF GRAY, CE MEI, C GP INT COUNCIL AERONAUT SCI TI LARGE-AMPLITUDE FINITE-ELEMENT FLUTTER ANALYSIS OF COMPOSITE PANELS N HYPERSONIC FLOW SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 1281 EP 1294 PG 14 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00166 ER PT B AU YIP, LP VIJGEN, PMHW HARDIN, JD AF YIP, LP VIJGEN, PMHW HARDIN, JD GP INT COUNCIL AERONAUT SCI TI IN-FLIGHT SURFACE-FLOW MEASUREMENTS ON A SUBSONIC TRANSPORT HIGH-LIFT FLAP SYSTEM SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 1392 EP 1406 PG 15 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00180 ER PT B AU CONWAY, BA AF CONWAY, BA GP INT COUNCIL AERONAUT SCI TI AEROSPACE MEASUREMENTS - CHALLENGES AND OPPORTUNITIES SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 1407 EP 1416 PG 10 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00181 ER PT B AU STEWART, JF BURCHAM, FW GATLIN, DH AF STEWART, JF BURCHAM, FW GATLIN, DH GP INT COUNCIL AERONAUT SCI TI FLIGHT-DETERMINED BENEFITS OF INTEGRATED FLIGHT-PROPULSION CONTROL-SYSTEMS SO ICAS PROCEEDINGS 1992, VOLS 1 AND 2: 18TH CONGRESS OF THE INTERNATIONAL COUNCIL OF THE AERONAUTICAL SCIENCES LA English DT Proceedings Paper CT 18th Congress of the International-Council-of-the-Aeronautical-Sciences CY SEP 20-25, 1992 CL BEIJING, PEOPLES R CHINA SP INT COUNCIL AERONAUT SCI C1 NASA,DRYDEN FLIGHT RES FACIL,EDWARDS AFB,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUTICS & ASTRONAUTICS PI WASHINGTON PA 370 L'ENFANT PROMENADE SW, WASHINGTON, DC 20024-2518 BN 1-56347-046-2 PY 1992 BP 1756 EP 1777 PG 22 WC Engineering, Aerospace SC Engineering GA BA84L UT WOS:A1992BA84L00223 ER PT J AU KLEIN, JD AF KLEIN, JD TI CALIBRATION OF COMPLEX POLARIMETRIC SAR IMAGERY USING BACKSCATTER CORRELATIONS SO IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS LA English DT Article ID RADAR AB A new technique for calibration of multipolarization synthetic aperture radar (SAR) imagery is described. If scatterer reciprocity and lack of correlation between co- and cross-polarized radar echoes (for azimuthally symmetric distributed targets) is assumed, the effects of signal leakage between the radar data channels can be removed without the use of known ground targets. If known targets are available, all data channels may be calibrated relative to one another and radiometrically as well The method is verified with simulations and application to airborne SAR data. RP KLEIN, JD (reprint author), CALTECH,JET PROP LAB,MS 300-235,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 13 TC 31 Z9 34 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9251 J9 IEEE T AERO ELEC SYS JI IEEE Trans. Aerosp. Electron. Syst. PD JAN PY 1992 VL 28 IS 1 BP 183 EP 194 DI 10.1109/7.135444 PG 12 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA HP654 UT WOS:A1992HP65400017 ER PT J AU SUN, XL DAVIDSON, FM BOUTSIKARIS, L ABSHIRE, JB AF SUN, XL DAVIDSON, FM BOUTSIKARIS, L ABSHIRE, JB TI RECEIVER CHARACTERISTICS OF LASER ALTIMETERS WITH AVALANCHE PHOTODIODES SO IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS LA English DT Article ID OPTICAL RECEIVERS AB The receiver characteristics of a laser altimeter system containing an avalanche photodiode photodetector are analyzed using the Gaussian approximation, the saddle-point approximation, and a nearly exact analysis. The last two methods are shown to yield very similar results except when the background noise is extremely low and the probability of false alarm is high. However, the Gaussian approximation method is shown to cause significant errors even under relatively high levels of background noise and received signal energy C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP SUN, XL (reprint author), JOHNS HOPKINS UNIV,DEPT ELECT & COMP ENGN,BALTIMORE,MD 21218, USA. RI Davidson, Frederic /A-3273-2010; Sun, Xiaoli/B-5120-2013; Abshire, James/I-2800-2013 NR 19 TC 3 Z9 5 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9251 J9 IEEE T AERO ELEC SYS JI IEEE Trans. Aerosp. Electron. Syst. PD JAN PY 1992 VL 28 IS 1 BP 268 EP 275 DI 10.1109/7.135452 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA HP654 UT WOS:A1992HP65400025 ER PT J AU HEILIGMAN, GM PURDY, RJ AF HEILIGMAN, GM PURDY, RJ TI GRACEFUL DEGRADATION OF AN ADAPTIVE BEAMFORMING PROCESSOR SO IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS LA English DT Article AB The phase and amplitude weights of each element in an adaptive, digitally beamformed array antenna can be calculated by a systolic parallel processor. We propose that the entire weight calculation (both QR decomposition, previously discussed by Gentleman and Kung, and the back-substitutions, which we present here for the first time) be performed in a triangular array of processors. This has the highly desirable property of graceful degradation: the loss of one or more component processors does not cause the computed weights to degrade catastrophically. The loss of a processor in the systolic array merely reduces the number of available degrees of freedom. Moreover, the processing array does not need to be globally reconfigured, the functions of all the remaining processors are unaffected and their interconnections are undisturbed. We describe the processing flow in the systolic array, show how its degradation is inherently graceful and present a realistic example of graceful degradation. The specific example demonstrates full null depth even when one processing element in the array is totally nonfunctional This property is extensible to array processors with more than one failed element; null depth is preserved at the expense of degrees of freedom in shaping the main beam. C1 LINCOLN LAB,LEXINGTON,MA 02173. RP HEILIGMAN, GM (reprint author), STERLING FED SYST,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9251 J9 IEEE T AERO ELEC SYS JI IEEE Trans. Aerosp. Electron. Syst. PD JAN PY 1992 VL 28 IS 1 BP 305 EP 315 DI 10.1109/7.135455 PG 11 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA HP654 UT WOS:A1992HP65400028 ER PT J AU NGUYEN, TM AF NGUYEN, TM TI THE BEHAVIOR OF A COSTAS LOOP IN THE PRESENCE OF SPACE TELEMETRY SIGNALS SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article AB When the Costas loop is operated in the presence of a residual carrier space telemetry signal, the loop reconstructs its carrier reference from an input signal whose carrier component is not completely suppressed. The telemetry signal investigated in this paper is generated by phase shift-keying the data onto a subcarrier and then phase modulating onto the sinusoidal carrier. The telemetry modulation index, telemetry bit rate, subcarrier waveform, and subcarrier frequency are shown to be the key system parameters that contribute to the performance degradation of a Costas loop. Furthermore, the effect of Doppler shift on the loop is also investigated in this paper. RP NGUYEN, TM (reprint author), JET PROP LAB,COMMUN SYST RES SECT,DIGITAL SIGNAL PROC RES GRP,PASADENA,CA 91190, USA. NR 4 TC 1 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD JAN PY 1992 VL 40 IS 1 BP 190 EP 198 DI 10.1109/26.126720 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA HL201 UT WOS:A1992HL20100021 ER PT J AU KING, MD KAUFMAN, YJ MENZEL, WP TANRE, D AF KING, MD KAUFMAN, YJ MENZEL, WP TANRE, D TI REMOTE-SENSING OF CLOUD, AEROSOL, AND WATER-VAPOR PROPERTIES FROM THE MODERATE RESOLUTION IMAGING SPECTROMETER (MODIS) SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID SOLAR-RADIATION MEASUREMENTS; MARINE STRATOCUMULUS CLOUDS; OPTICAL-THICKNESS; SATELLITE MEASUREMENTS; PATTERN-RECOGNITION; LIGHT-SCATTERING; SOUNDER DATA; AVHRR DATA; CLEAR-SKY; CLIMATE AB The Moderate Resolution Imaging Spectrometer (MODIS) is an earth-viewing sensor being developed as a facility instrument for the Earth Observing System (EOS) to be launched in the late 1990's. MODIS consists of two separate instruments that scan a swath width sufficient to provide nearly complete global coverage every 2 days from a polar-orbiting, sun-synchronous, platform at an altitude of 705 km. MODIS-N (nadir) will provide images in 36 spectral bands between 0.415 and 14.235-nu-m with spatial resolutions of 250 m (2 bands), 500 m (5 bands), and 1000 m (29 bands). These bands have been carefully selected to enable advanced studies of land, ocean, and atmospheric processes. In this paper we describe the status of MODIS-N and its companion instrument MODIS-T (tilt), a tiltable cross-track scanning spectrometer with 32 uniformly spaced channels between 0.410 and 0.875-nu-m. In addition, we review the various methods being developed for the remote sensing of atmospheric properties using MODIS, placing primary emphasis on the principal atmospheric applications of determining the optical, microphysical, and physical properties of clouds and aerosol particles from spectral reflection and thermal emission measurements. In addition to cloud and aerosol properties, MODIS-N will be used for determining the total precipitable water vapour and atmospheric stability. The physical principles behind the determination of each of these atmospheric products will be described herein, together with an example of their application to aircraft and/or satellite measurements. Extensions of these and related methods to MODIS observations pose an extraordinary challenge as well as a unique opportunity to enhance our understanding of the earth-atmosphere-ocean system. C1 UNIV LILLE 1,OPT ATMOSPHER LAB,F-59655 VILLENEUVE DASCQ,FRANCE. NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ADV SATELLITE PROD PROJECT,MADISON,WI 53706. RP KING, MD (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771, USA. RI Menzel, W. Paul/B-8306-2011; King, Michael/C-7153-2011 OI Menzel, W. Paul/0000-0001-5690-1201; King, Michael/0000-0003-2645-7298 NR 106 TC 530 Z9 569 U1 12 U2 73 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1992 VL 30 IS 1 BP 2 EP 27 DI 10.1109/36.124212 PG 26 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA HC422 UT WOS:A1992HC42200001 ER PT J AU MILLER, KW MORELL, LJ NOONAN, RE PARK, SK NICOL, DM MURRILL, BW VOAS, JM AF MILLER, KW MORELL, LJ NOONAN, RE PARK, SK NICOL, DM MURRILL, BW VOAS, JM TI ESTIMATING THE PROBABILITY OF FAILURE WHEN TESTING REVEALS NO FAILURES SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Article DE BAYESIAN ESTIMATION; INPUT DISTRIBUTIONS; PROBABILITY OF FAILURE; REUSABLE SOFTWARE; SOFTWARE RELIABILITY; SOFTWARE TESTING ID SOFTWARE-RELIABILITY; MODEL AB In this paper we introduce formulae for estimating the probability of failure when testing reveals no errors. These formulae incorporate random testing results, information about the input distribution, and prior assumptions about the probability of failure of the software. The formulae are not restricted to equally-likely input distributions, and the probability of failure estimate can be adjusted when assumptions about the input distribution change. The formulae are based on a discrete sample space statistical model of software and include Bayesian prior assumptions. Reusable software and software in life-critical applications are particularly appropriate candidates for this type of analysis. C1 COLL WILLIAM & MARY,DEPT COMP SCI,WILLIAMSBURG,VA 23185. HAMPTON UNIV,COMP SCI,HAMPTON,VA 23368. VIRGINIA COMMONWEALTH UNIV,DEPT MATH SCI,RICHMOND,VA 23284. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 25 TC 87 Z9 102 U1 0 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0098-5589 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD JAN PY 1992 VL 18 IS 1 BP 33 EP 43 DI 10.1109/32.120314 PG 11 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA HA797 UT WOS:A1992HA79700004 ER PT J AU MILLER, RE PAUL, S AF MILLER, RE PAUL, S TI GENERATING CONFORMANCE TEST SEQUENCES FOR COMBINED CONTROL AND DATA-FLOW OF COMMUNICATION PROTOCOLS SO IFIP TRANSACTIONS C-COMMUNICATION SYSTEMS LA English DT Article AB Using a limited version of Estelle, from which a specification can be represented in terms of an Extended Finite State Machine (EFSM), we develop a technique to generate conformance tests which test both the data flow as well as the control flow. From the EFSM, we generate a Finite State Machine (FSM) with several transitions corresponding to a single transition of the EFSM. Moreover, the input and output parameters are also modified so that an ''equivalent'' FSM is obtained. The data flow graph (DFG) is constructed directly from the ''equivalent'' FSM. Test segments axe obtained from the data flow graph as well as from the control flow graph and are combined ''carefully'' to generate an executable test sequence. Test data for the above sequence is chosen using a mutation technique to guarantee detection of specific kinds of faults in the data flow. Control flow is tested in the conventional way. C1 NASA,GODDARD SPACE FLIGHT CTR,CTR EXCELLENCE SPACE DATA & INFORMAT SCI,GREENBELT,MD 20771. UNIV MARYLAND,DEPT ELECT ENGN,COLL PK,MD 20742. RP MILLER, RE (reprint author), UNIV MARYLAND,DEPT COMP SCI,COLL PK,MD 20742, USA. NR 18 TC 6 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-549X J9 IFIP TRANS C JI IFIP Trans. C-Commun. Syst. PY 1992 VL 8 BP 13 EP 27 PG 15 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA LG019 UT WOS:A1992LG01900003 ER PT J AU GOODWIN, TJ JESSUP, JM WOLF, DA AF GOODWIN, TJ JESSUP, JM WOLF, DA TI MORPHOLOGICAL-DIFFERENTIATION OF COLON-CARCINOMA CELL-LINES HT-29 AND HT-29KM IN ROTATING-WALL VESSELS SO IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY-ANIMAL LA English DT Article DE ROTATING-WALL VESSELS; TISSUE MODELING; MICROCARRIER; 3-DIMENSIONAL; DIFFERENTIATION; COLON CANCER ID EPIDERMAL GROWTH-FACTOR; EPITHELIAL-MESENCHYMAL INTERACTIONS; ENTEROCYTIC DIFFERENTIATION; COLORECTAL CARCINOMAS; EXTRACELLULAR-MATRIX; GOBLET CELLS; CANCER-CELLS; CULTURE; INVITRO; EXPRESSION AB A new low shear stress microcarrier culture system has been developed at NASA's Johnson Space Center that permits three-dimensional tissue culture. Two established human colon adenocarcinoma cell lines, HT-29, an undifferentiated, and HT-29KM, a stable, moderately differentiated subline of HT-29, were grown in new tissue culture bioreactors Rotating-Wall Vessels (RWVs). RWVs are used in conjunction with multicellular cocultivation to develop a unique in vitro tissue modeling system. Cells were cultivated on Cytodex-3 microcarrier beads, with and without mixed normal human colonic fibroblasts, which served as the mesenchymal layer. Culture of the tumor tines in the absence of fibroblasts produced spheroidlike growth and minimal differentiation. In contrast, when tumor lines were co-cultivated with normal colonic fibroblasts, initial growth was confined to the fibroblast population until the microcarriers were covered. The tumor cells then commenced proliferation at an accelerated rate, organizing themselves into three-dimensional tissue masses that achieved 1.0- to 1.5-cm diameters. The masses displayed glandular structures, apical and internal glandular microvilli. tight intercellular junctions, desmosomes, cellular polarity. sinusoid development, internalized mucin, and structural organization akin to normal colon crypt development. Differentiated samples were subjected to transmission and scanning electron microscopy and histologic analysis, revealing embryoniclike mesenchymal cells lining the areas around the growth matrices. Necrosis was minimal throughout the tissue masses. These data suggest that the RWV affords a new model for investigation and isolation of growth, regulatory, and structural processes within neoplastic and normal tissue. C1 NASA,LYNDON B JOHNSON SPACE CTR,KRUG LIFE SCI,HOUSTON,TX 77058. NEW ENGLAND DEACONESS HOSP,BOSTON,MA 02215. RP GOODWIN, TJ (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,BIOMED OPERAT & RES BRANCH,SD4,1290 HERCULES DR,HOUSTON,TX 77058, USA. NR 45 TC 75 Z9 75 U1 0 U2 1 PU SOC IN VITRO BIOLOGY PI COLUMBIA PA 8815 CENTRE PARK DR,STE 210, COLUMBIA, MD 21045 SN 1071-2690 J9 IN VITRO CELL DEV-AN JI In Vitro Cell. Dev. Biol.-Anim. PD JAN PY 1992 VL 28A IS 1 BP 47 EP 60 PG 14 WC Cell Biology; Developmental Biology SC Cell Biology; Developmental Biology GA HH818 UT WOS:A1992HH81800010 PM 1730571 ER PT B AU SCHWUTTKE, UM QUAN, AG ANGELINO, R CHILDS, CL VEREGGE, JR YEUNG, RY RIVERA, MB AF SCHWUTTKE, UM QUAN, AG ANGELINO, R CHILDS, CL VEREGGE, JR YEUNG, RY RIVERA, MB BE Scott, AC Klahr, P TI MARVEL - A DISTRIBUTED REAL-TIME MONITORING AND ANALYSIS APPLICATION SO INNOVATIVE APPLICATIONS OF ARTIFICIAL INTELLIGENCE 4 LA English DT Proceedings Paper CT Conf on Innovative Applications of Artificial Intelligence 4 (IAAI-92) CY JUL 13-16, 1992 CL SAN JOSE, CA C1 JET PROP LAB,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELLIGENCE PI MENLO PK PA 445 BURGESS DR, MENLO PK, CA 94025 BN 0-262-69155-8 PY 1992 BP 89 EP 106 PG 18 WC Computer Science, Artificial Intelligence SC Computer Science GA BZ49J UT WOS:A1992BZ49J00006 ER PT J AU BEAVER, EA BAITY, WA BRANDT, JC EBBETS, DC GARNER, H HEAP, SR LINDLER, DJ LINSKY, JB LYONS, RW ROSENBLATT, EI AF BEAVER, EA BAITY, WA BRANDT, JC EBBETS, DC GARNER, H HEAP, SR LINDLER, DJ LINSKY, JB LYONS, RW ROSENBLATT, EI TI ORBITAL PERFORMANCE OF THE GODDARD HIGH-RESOLUTION SPECTROGRAPH DIGICON DETECTORS ON THE HUBBLE SPACE TELESCOPE SO INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article AB The design and specification of space-based detectors generally requires considerable analysis together with experimental simulation to characterize and minimize the influence of the dynamic space environment on the detector performance. We present the results of an extensive investigation of the in-orbit performance of the Digicon detectors in the Goddard High Resolution Spectrograph (GHRS), conducted as part of the commissioning phase of the Hubble Space Telescope (HST). This paper includes results on the background noise, sensor stability, orbital management of detector activities, and relevant GHRS astronomy applications. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. UNIV COLORADO, BOULDER, CO 80309 USA. BALL AEROSP SYST GRP, BOULDER, CO 80306 USA. ADV COMP CONCEPTS INC, POTOMAC, MD 20854 USA. RP BEAVER, EA (reprint author), UNIV CALIF SAN DIEGO, CTR ASTROPHYS & SPACE SCI, LA JOLLA, CA 92093 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0951-3248 J9 INST PHYS CONF SER JI Inst. Phys. Conf. Ser. PY 1992 IS 121 BP 65 EP 74 PG 10 WC Physics, Multidisciplinary SC Physics GA HV057 UT WOS:A1992HV05700009 ER PT J AU Klima, EF AF Klima, EF GP SE FISHERIES ASSOC TI Shrimp bycatch - Hopes and fears SO INTERNATIONAL CONFERENCE ON SHRIMP BYCATCH LA English DT Proceedings Paper CT International Conference on Shrimp Bycatch CY MAY 24-27, 1992 CL LAKE BUENA VISTA, FL SP SE Fisheries Assoc C1 US DEPT COMMERCE,NATL MARINE FISHERIES SERV,GALVESTON,TX 77551. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOUTHEASTERN FISHERIES ASSOCIATION PI TALLAHASSEE PA 312 E GEORGIA STREET, TALLAHASSEE, FL 32310 PY 1992 BP 5 EP 12 PG 8 WC Fisheries SC Fisheries GA BF41E UT WOS:A1992BF41E00001 ER PT J AU Seidel, WR AF Seidel, WR GP SE FISHERIES ASSOC TI Federal perspective of bycatch in the United States SO INTERNATIONAL CONFERENCE ON SHRIMP BYCATCH LA English DT Proceedings Paper CT International Conference on Shrimp Bycatch CY MAY 24-27, 1992 CL LAKE BUENA VISTA, FL SP SE Fisheries Assoc C1 NATL MARINE FISHERIES SERV,US DEPT COMMERCE,SE FISHERIES SCI CTR,PASCAGOULA,MS. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOUTHEASTERN FISHERIES ASSOCIATION PI TALLAHASSEE PA 312 E GEORGIA STREET, TALLAHASSEE, FL 32310 PY 1992 BP 21 EP 27 PG 7 WC Fisheries SC Fisheries GA BF41E UT WOS:A1992BF41E00003 ER PT J AU Watson, JW AF Watson, JW GP SE FISHERIES ASSOC TI Status of knowledge in the United States relating fish behavior to the reduction of bycatch SO INTERNATIONAL CONFERENCE ON SHRIMP BYCATCH LA English DT Proceedings Paper CT International Conference on Shrimp Bycatch CY MAY 24-27, 1992 CL LAKE BUENA VISTA, FL SP SE Fisheries Assoc C1 NATL MARINE FISHERIES SERV,US DEPT COMMERCE,SE FISHERIES SCI CTR,MISSISSIPPI LABS,PASCAGOULA,MS. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SOUTHEASTERN FISHERIES ASSOCIATION PI TALLAHASSEE PA 312 E GEORGIA STREET, TALLAHASSEE, FL 32310 PY 1992 BP 185 EP 195 PG 11 WC Fisheries SC Fisheries GA BF41E UT WOS:A1992BF41E00018 ER PT J AU HEEGER, DJ JEPSON, AD AF HEEGER, DJ JEPSON, AD TI SUBSPACE METHODS FOR RECOVERING RIGID MOTION .1. ALGORITHM AND IMPLEMENTATION SO INTERNATIONAL JOURNAL OF COMPUTER VISION LA English DT Article ID RELATIVE DEPTH MAP; OPTICAL-FLOW; 3-DIMENSIONAL MOTION; VISUAL-MOTION; IMAGE FLOW; PARALLAX FIELD; EGO-MOTION; MOVEMENT; OBJECTS; PLANE AB As an observer moves and explores the environment, the visual stimulation in his/her eye is constantly changing. Somehow he/she is able to perceive the spatial layout of the scene, and to discern his/her movement through space. Computational vision researchers have been trying to solve this problem for a number of years with only limited success. It is a difficult problem to solve because the optical flow field is nonlinearly related to the 3D motion and depth parameters. Here, we show that the nonlinear equation describing the optical flow field can be split by an exact algebraic manipulation to form three sets of equations. The first set relates the flow field to only the translational component of 3D motion. Thus, depth and rotation need not be known or estimated prior to solving for translation. Once the translation has been recovered, the second set of equations can be used to solve for rotation. Finally, depth can be estimated with the third set of equations, given the recovered translation and rotation. The algorithm applies to the general case of arbitrary motion with respect to an arbitrary scene. It is simple to compute, and it is plausible biologically. The results reported in this article demonstrate the potential of our new approach, and show that it performs favorably when compared with two other well-known algorithms. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. STANFORD UNIV,DEPT PSYCHOL,STANFORD,CA 94305. UNIV TORONTO,DEPT COMP SCI,TORONTO M5S 1A4,ONTARIO,CANADA. NR 73 TC 222 Z9 226 U1 5 U2 14 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0920-5691 J9 INT J COMPUT VISION JI Int. J. Comput. Vis. PD JAN PY 1992 VL 7 IS 2 BP 95 EP 117 DI 10.1007/BF00128130 PG 23 WC Computer Science, Artificial Intelligence SC Computer Science GA HK110 UT WOS:A1992HK11000001 ER PT J AU TISCHLER, MB AF TISCHLER, MB TI SPECIAL ISSUE ON AIRCRAFT FLIGHT CONTROL SO INTERNATIONAL JOURNAL OF CONTROL LA English DT Editorial Material RP TISCHLER, MB (reprint author), NASA,AMES RES CTR,MAIL STOP N211-2,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0020-7179 J9 INT J CONTROL JI Int. J. Control PD JAN PY 1992 VL 55 IS 1 BP 1 EP 1 PG 1 WC Automation & Control Systems SC Automation & Control Systems GA GY114 UT WOS:A1992GY11400001 ER PT J AU GAYDA, J GABB, TP AF GAYDA, J GABB, TP TI ISOTHERMAL FATIGUE BEHAVIOR OF A [90-DEGREES]8 SIC/TI-15-3 COMPOSITE AT 426-DEGREES-C SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article AB The transverse fatigue behaviour of a unidirectional, SiC/Ti-15-3 composite (35 v/o SiC, [90-degrees]8) was evaluated at 426-degrees-C. The fatigue behaviour of the composite along the fibre direction ([0-degrees]8) and of unreinforced Ti-15-3 alloy were also studied for purposes of comparison. The [90-degrees]8 composite fatigue life was much shorter than the [0-degrees]8 life. Furthermore, the [90-degrees]8 fatigue life was also found to be far lower than that of the unreinforced Ti-15-3 alloy. A simple, one-dimensional model for [90-degrees]8 fatigue behaviour indicated that the short life of the composite in this orientation resulted, in large part, from weak fibre-matrix bond strength. This conclusion was supported by fractographic evidence showing numerous fatigue initiation sites along the fibre-matrix interfaces. RP GAYDA, J (reprint author), NASA,RES CTR,21000 BROOKPK RD,CLEVELAND,OH 44135, USA. NR 9 TC 11 Z9 11 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD JAN PY 1992 VL 14 IS 1 BP 14 EP 20 DI 10.1016/0142-1123(92)90148-6 PG 7 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA HA967 UT WOS:A1992HA96700002 ER PT J AU SARKER, JC PURVIANCE, JE AF SARKER, JC PURVIANCE, JE TI YIELD SENSITIVITY STUDY OF A1GAAS/GAAS HIGH ELECTRON-MOBILITY TRANSISTOR SO INTERNATIONAL JOURNAL OF MICROWAVE AND MILLIMETER-WAVE COMPUTER-AIDED ENGINEERING LA English DT Article AB A simple graphical statistical method is presented and is used to study the statistical sensitivity of the AlGaAs/GaAs High Electron Mobility Transistor (HEMT) small-signal performances to physical model parameters. Using an analytical model and applying numerical techniques, the small-signal performances, transconductance, gate-to-source capacitance, current gain cut-off frequency, and the optimum cut-off frequency are calculated for four different HEMTs. These are then used as the device specifications in the Monte Carlo-based sensitivity analysis. Based on the model, a device simulator is developed in which the gate length, the gate width, and the carrier mobility are statistically varied simultaneously about their nominal values. The yield factor histograms for each small-signal parameter and its sensitivity to the process parameter variations are determined. In this work, we report that the current gain cut-off frequency increases as the carrier mobility increases, but it is almost independent of the gate width. We observe that the gate-to-source capacitance is independent of the carrier mobility, but it is strongly dependent on the transistor dimension. All the performance yields analyzed here go down as the gate length increases. C1 UNIV IDAHO,NASA,CTR SPACE ENGN RES CTR,MOSCOW,ID 83843. RP SARKER, JC (reprint author), UNIV IDAHO,DEPT ELECT ENGN,MOSCOW,ID 83843, USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 1050-1827 J9 INT J MICROWAVE MILL JI Int. J. Microw. Millimeter-Wave Comput.-Aided Eng. PD JAN PY 1992 VL 2 IS 1 BP 12 EP 27 DI 10.1002/mmce.4570020104 PG 16 WC Computer Science, Interdisciplinary Applications; Engineering, Electrical & Electronic SC Computer Science; Engineering GA GV382 UT WOS:A1992GV38200003 ER PT B AU KAYE, JA AF KAYE, JA BE KAYE, JA TI ISOTOPE EFFECTS IN GAS-PHASE CHEMICAL-REACTIONS AND PHOTODISSOCIATION PROCESSES - OVERVIEW SO ISOTOPE EFFECTS IN GAS-PHASE CHEMISTRY SE ACS SYMPOSIUM SERIES LA English DT Editorial Material CT SYMP ON ISOTOPE EFFECTS IN GAS-PHASE CHEMISTRY, AT THE 201ST NATIONAL MEETING OF THE AMERICAN CHEMICAL SOC CY APR 14-19, 1991 CL ATLANTA, GA SP AMER CHEM SOC, DIV PHYS CHEM RP KAYE, JA (reprint author), NASA HEADQUARTERS,DIV EARTH SCI & APPLICAT,WASHINGTON,DC 20546, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA WASHINGTON BN 0-8412-2471-4 J9 ACS SYM SER PY 1992 VL 502 BP 1 EP 14 PG 14 WC Chemistry, Physical; Geosciences, Multidisciplinary; Physics, Atomic, Molecular & Chemical SC Chemistry; Geology; Physics GA BW92N UT WOS:A1992BW92N00001 ER PT J AU BOWEN, JM KNAUSS, WG AF BOWEN, JM KNAUSS, WG TI THE CHARACTERIZATION OF THE ENERGY OF FRACTURE AT OR NEAR INTERFACES BETWEEN VISCOELASTIC SOLIDS SO JOURNAL OF ADHESION LA English DT Article DE BIMATERIAL INTERFACE; INTERFACE CRACK; TIME-DEPENDENT FAILURE; VISCOELASTIC ADHESIVE BONDING; FAILURE STRENGTH INTERFACE STRENGTH ID CRACK INITIATION; GROWTH; MEDIA AB The problem of separating two viscoelastic solids of different properties in a time dependent manner is considered. This work is part of a wider study concerned with the time dependent failure of viscoelastic adhesive bonds at and/or near the interface, including propagation of a crack away from the interface. Inasmuch as such a study requires sufficient bond strength to control the orientation of crack propagation, this paper deals with the characterization of interface strength. Following earlier analysis of crack propagation in homogeneous and bimaterial viscoelastic solids, experimental studies concerned with rate dependent fracture at the interface are evaluated in terms of the viscoelastic functions associated with homogeneous fracture of the adherends and a separate interface-intrinsic strength which is determined by the chemistry at the interface. This interface strength multiplies a viscoelastic function, which, for the interface problem, is a combination of the properties of the homogeneous solids. Interface strength on the same order as those of the adherends is achieved. C1 CALTECH,GRAD AERONAUT LABS,PASADENA,CA 91125. JET PROP LAB,PASADENA,CA 91109. NR 16 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, BERKS, ENGLAND RG1 8JL SN 0021-8464 J9 J ADHESION JI J. Adhes. PY 1992 VL 39 IS 1 BP 43 EP 59 DI 10.1080/00218469208026537 PG 17 WC Engineering, Chemical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA JW079 UT WOS:A1992JW07900004 ER PT J AU HARRIS, RV AF HARRIS, RV TI ON THE THRESHOLD - THE OUTLOOK FOR SUPERSONIC AND HYPERSONIC AIRCRAFT SO JOURNAL OF AIRCRAFT LA English DT Article RP HARRIS, RV (reprint author), NASA,LANGLEY RES CTR,AERONAUT,HAMPTON,VA 23665, USA. NR 0 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 SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 1992 VL 29 IS 1 BP 10 EP 19 DI 10.2514/3.46119 PG 10 WC Engineering, Aerospace SC Engineering GA HC691 UT WOS:A1992HC69100002 ER PT J AU ADDY, HE KEITH, TG AF ADDY, HE KEITH, TG TI INVESTIGATION OF THE DIFFUSER FLOW QUALITY IN AN ICING RESEARCH WIND-TUNNEL SO JOURNAL OF AIRCRAFT LA English DT Article AB In this paper, the flow in the diffuser section of the Icing Research Tunnel at the NASA Lewis Research Center is both numerically and experimentally investigated. To accomplish the numerical portion of the work, an existing computer code is utilized. The code, known as PARC3D, is based on the Beam-Warming algorithm applied to the strong conservation law form of the complete Navier-Stokes equations. Following a brief description of the diffuser geometry, the measured flow characteristics are described. A brief discussion of the code work is also provided. The flow measurements show a highly nonuniform velocity profile across the diffuser exit with boundary-layer growth more prevalent near the centers of the walls rather than in the corners of the diffuser. Predicted velocity profiles at the centerline are similar to those measured; however, the code did not accurately predict the boundary-layer behavior near the corners. RP ADDY, HE (reprint author), NASA,LEWIS RES CTR,DIV PROPUCS SYST,ICING & CRYOGEN TECHNOL BRANCH,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 1992 VL 29 IS 1 BP 47 EP 51 DI 10.2514/3.46123 PG 5 WC Engineering, Aerospace SC Engineering GA HC691 UT WOS:A1992HC69100006 ER PT J AU HINTON, DA AF HINTON, DA TI FORWARD-LOOK WIND-SHEAR DETECTION FOR MICROBURST RECOVERY SO JOURNAL OF AIRCRAFT LA English DT Article AB An effort is in progress by NASA, the Federal Aviation Administration, and the industry to reduce the threat Of convective microburst wind-shear phenomena to aircraft. This paper describes an effort to quantify the benefits of forward-look sensing and to develop and test a candidate set of strategies for recovery from inadvertent microburst encounters during the landing approach. Initial development of recovery strategies was performed in batch simulation prior to piloted simulation evaluation using a full dynamic airplane model. The results of this effort indicate that the factor that most strongly effects a microburst recovery is the time at which the recovery is initiated. Improving the alert time by 5 s generally provided a greater recovery performance increase than could be achieved by changing the recovery strategy. Forward-look alerts given 10 s prior to microburst entry permitted recoveries to be made with negligible altitude loss. RP HINTON, DA (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 0 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 SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 1992 VL 29 IS 1 BP 63 EP 66 DI 10.2514/3.46125 PG 4 WC Engineering, Aerospace SC Engineering GA HC691 UT WOS:A1992HC69100008 ER PT J AU BONHAUS, DL WORNOM, SF AF BONHAUS, DL WORNOM, SF TI COMPARISON OF 2 NAVIER-STOKES CODES FOR ATTACHED TRANSONIC WING FLOWS SO JOURNAL OF AIRCRAFT LA English DT Article AB In the present study, two codes that solve the three-dimensional thin-layer Navier-Stokes (TLNS) equations are used to compute the steady-state flow for two test cases representing typical finite wings at transonic conditions. The first code, CFL3D, uses an implicit upwind-biased scheme, while the second, TLNS3D, uses an explicit central-difference scheme. Comparisons of computed surface pressure distributions with experimental data and analysis of global aerodynamic coefficient data indicate that for a given grid, CFL3D is more accurate, while TLNS3D is more efficient. To achieve the same level of accuracy, TLNS3D requires more grid points than CFL3D, but converges using slightly less computer time. RP BONHAUS, DL (reprint author), NASA,LANGLEY RES CTR,DIV FLUID MECH,COMPUTAT AERODYNAM BRANCH,HAMPTON,VA 23665, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 1992 VL 29 IS 1 BP 101 EP 107 DI 10.2514/3.46131 PG 7 WC Engineering, Aerospace SC Engineering GA HC691 UT WOS:A1992HC69100014 ER PT J AU SAGAWA, S MIKI, K TAJIMA, F TANAKA, H CHOI, JK KEIL, LC SHIRAKI, K GREENLEAF, JE AF SAGAWA, S MIKI, K TAJIMA, F TANAKA, H CHOI, JK KEIL, LC SHIRAKI, K GREENLEAF, JE TI EFFECT OF DEHYDRATION ON THIRST AND DRINKING DURING IMMERSION IN MEN SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE PLASMA VOLUME; PLASMA OSMOLALITY; PLASMA SODIUM; PLASMA ARGININE VASOPRESSIN; PLASMA ATRIAL NATRIURETIC PEPTIDES; PLASMA RENIN ACTIVITY ID IMPEDANCE CARDIOGRAPHY; WATER IMMERSION; VASOPRESSIN; VOLUME; STRESS; HUMANS; RATS AB The mechanism for reduced voluntary water intake during water immersion was studied in eight men (19-25 yr of age) immersed to the neck while sitting for 3 h at 34.5-degrees-C or in air at 28-degrees-C when euhydrated (Eu-H2O and Eu-air, respectively) and hypohydrated (Hypo-H2O and Hypo-air) by 3.6% body weight loss. Thirst sensations (degree of thirst, mouth dryness and taste, drinking desirability, and stomach fullness) were similar at the beginning of Hypo-air and Hypo-H2O test periods. Initial drinking of tap water (15-degrees-C) was 216 +/- 30 ml/7 min (P < 0.05) with Hypo-air, decreased to 108 +/- 28 ml/7 min (P < 0.05) with Hypo-H2O and was 10-50 ml/10-30 min thereafter. Intake was < 10 ml/10-30 min in Eu-air, and there was no drinking in Eu-H2O. Within the first 10 min of immersion, compared with Hypo-air findings, the significant reduction in drinking in the Hypo-H2O experiment was associated with unchanged plasma Na+, plasma osmolality, heart rates, and mean arterial pressures; the different responses were increased cardiac output, plasma volume, and atrial natriuretic peptides and decreased plasma renin activity and arginine vasopressin. Thus the extracellular pathway, as opposed to the osmotic pathway, appears to be the major mechanism for immersion-induced suppression of drinking. C1 NASA,AMES RES CTR,DIV LIFE SCI,MOFFETT FIELD,CA 94035. RP SHIRAKI, K (reprint author), UNIV OCCUPAT & ENVIRONM HLTH,SCH MED,DEPT PHYSIOL,1-1 ISEIGAOKA,YAHATANISHI KU,KITAKYUSHU,FUKUOKA 807,JAPAN. NR 25 TC 27 Z9 27 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD JAN PY 1992 VL 72 IS 1 BP 128 EP 134 PG 7 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA HA815 UT WOS:A1992HA81500019 PM 1531647 ER PT J AU BAUSCHLICHER, CW LANGHOFF, SR WALCH, SP AF BAUSCHLICHER, CW LANGHOFF, SR WALCH, SP TI THEORETICAL-STUDY OF THE BOND-DISSOCIATION ENERGIES OF METHANOL SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID BASIS SETS; CONTRACTION; CI(SD); ATOMS; CH3O AB We present a theoretical study of the bond dissociation energies (D0) for H2O and CH3OH. The C-H and O-H bond energies are computed accurately with the modified coupled-pair functional (MCPF) method using a large basis set. For these bonds, an accuracy of +/- 2 kcal/mol is achieved, which is consistent with the C-H and C-C single bond energies of other molecules. The C-O bond is much more difficult to compute accurately because it requires higher levels of correlation treatment and more extensive one-particle basis sets. C1 ELORET INST,SUNNYVALE,CA 94087. RP BAUSCHLICHER, CW (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 27 TC 44 Z9 44 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1992 VL 96 IS 1 BP 450 EP 454 DI 10.1063/1.462480 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA GY249 UT WOS:A1992GY24900047 ER PT J AU FARLEY, GL JONES, RM AF FARLEY, GL JONES, RM TI CRUSHING CHARACTERISTICS OF CONTINUOUS FIBER-REINFORCED COMPOSITE TUBES SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE COMPOSITE MATERIALS; ENERGY ABSORPTION; CRUSHING; MODES; MECHANISMS; TRANSVERSE SHEARING; LAMINA BENDING; LOCAL BUCKLING; BRITTLE FRACTURE ID CRASHWORTHY AB Composite tubes can be reinforced with continuous fibers. When such tubes are subjected to crushing loads, the response is complex and depends on interaction between the different mechanisms that control the crushing process. The modes of crushing and their controlling mechanisms are described. Also, the resulting crushing process and its efficiency are addressed. C1 VIRGINIA POLYTECH INST & STATE UNIV,DEPT ENGN SCI & MECH,BLACKSBURG,VA 24061. RP FARLEY, GL (reprint author), NASA,LANGLEY RES CTR,USA,AVSCOM AEROSTRUCT DIRECTORATE,HAMPTON,VA 23665, USA. NR 14 TC 159 Z9 165 U1 5 U2 12 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 1 BP 37 EP 50 DI 10.1177/002199839202600103 PG 14 WC Materials Science, Composites SC Materials Science GA HC678 UT WOS:A1992HC67800003 ER PT J AU FARLEY, GL JONES, RM AF FARLEY, GL JONES, RM TI ANALOGY FOR THE EFFECT OF MATERIAL AND GEOMETRICAL VARIABLES ON ENERGY-ABSORPTION CAPABILITY OF COMPOSITE TUBES SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article AB Simplified procedures for determining the qualitative effect a variable has on structural response of a composite tube are very useful in both preliminary design as well as in providing insight into the general response. An analysis procedure is presented that can be used to determine the qualitative change in the sustained crushing load due to a change in specimen material properties or geometry. The analysis procedure is similar in form to the equation for the buckling load of a column on an elastic foundation. C1 VIRGINIA POLYTECH INST & STATE UNIV,DEPT ENGN SCI & MECH,BLACKSBURG,VA 24061. RP FARLEY, GL (reprint author), NASA,LANGLEY RES CTR,USA,AVSCOM AEROSTRUCT DIRECTORATE,HAMPTON,VA 23665, USA. NR 3 TC 44 Z9 48 U1 2 U2 5 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 1 BP 78 EP 89 DI 10.1177/002199839202600105 PG 12 WC Materials Science, Composites SC Materials Science GA HC678 UT WOS:A1992HC67800005 ER PT J AU FARLEY, GL JONES, RM AF FARLEY, GL JONES, RM TI PREDICTION OF THE ENERGY-ABSORPTION CAPABILITY OF COMPOSITE TUBES SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article AB A method of predicting the crash-related energy-absorption capability of composite tubes is presented. The method is based upon a phenomenological model of the crushing process exhibited by continuous-fiber-reinforced tubes. A finite element method is used to model the crushing process. The analysis is compared with experiments on Kevlar-epoxy and graphite-epoxy tubes. Reasonable agreement is obtained between the analysis and experiment. C1 VIRGINIA POLYTECH INST & STATE UNIV,DEPT ENGN SCI & MECH,BLACKSBURG,VA 24061. RP FARLEY, GL (reprint author), USA,AVSCOM,AEROSTRUCT DIRECTORATE,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 30 TC 55 Z9 56 U1 1 U2 7 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 3 BP 388 EP 404 DI 10.1177/002199839202600304 PG 17 WC Materials Science, Composites SC Materials Science GA HG531 UT WOS:A1992HG53100004 ER PT J AU MORTON, J HO, H TSAI, MY FARLEY, GL AF MORTON, J HO, H TSAI, MY FARLEY, GL TI AN EVALUATION OF THE IOSIPESCU SPECIMEN FOR COMPOSITE-MATERIALS SHEAR PROPERTY MEASUREMENT SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article ID UNIDIRECTIONAL COMPOSITES; MOIRE INTERFEROMETRY; STRESS-ANALYSIS AB A detailed evaluation of the suitability of the Iosipescu specimen tested in the modified Wyoming fixture is presented. A linear finite element model of the specimen is used to assess the uniformity of the shear stress field in the vicinity of the notch, and demonstrate the effect of the nonuniform stress field upon strain gage measurements used for the determination of composite shear moduli. Based upon test results from graphite-epoxy laminates, the proximity of the load introduction point to the test section and the material orthotropy greatly influence the individual gage readings, however, shear modulus determination is not significantly affected by the lack of pure shear. Correction factors are needed to allow for the nonuniformity of the strain field and the use of the average shear stress in the shear modulus evaluation. The correction factors are determined for the region occupied by the strain gage rosette. A comparison of the strain gage readings from one surface of a specimen with corresponding data from moire interferometry on the opposite face documented an extreme sensitivity of some fiber orientations to eccentric loading which induced twisting and spurious shear stress-strain curves. The discovery of specimen twisting explains the apparently inconsistent shear property data found in the literature. Recommendations for improving the reliability and accuracy of the shear modulus values are made, and the implications for shear strength measurement discussed. C1 NASA,LANGLEY RES CTR,USA,AEROSTRUCT DIRECTORATE,HAMPTON,VA 23665. RP MORTON, J (reprint author), VIRGINIA POLYTECH INST & STATE UNIV,DEPT ENGN SCI & MECH,BLACKSBURG,VA 24061, USA. NR 29 TC 67 Z9 67 U1 1 U2 9 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 5 BP 708 EP 750 DI 10.1177/002199839202600505 PG 43 WC Materials Science, Composites SC Materials Science GA HN547 UT WOS:A1992HN54700005 ER PT J AU ARNOLD, SM ARYA, VK MELIS, ME AF ARNOLD, SM ARYA, VK MELIS, ME TI REDUCTION OF THERMAL RESIDUAL-STRESSES IN ADVANCED METALLIC COMPOSITES BASED UPON A COMPENSATING COMPLIANT LAYER CONCEPT SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article AB High residual stresses within metal and intermetallic matrix composite systems can develop upon cooling from the processing temperature to room temperature due to the coefficient of thermal expansion (CTE) mismatch between the fiber and matrix. As a result, within certain composite systems, radial, circumferential, and/or longitudinal cracks have been observed to form at the fiber-matrix interface region. The compliant layer concept (insertion of a compensating interface material between the fiber and matrix) has been proposed to reduce or eliminate the residual stress buildup during cooling, and thus minimize cracking. The present study investigates elastic-plastically the viability of the proposed compliant layer concept. A detailed parametric study was conducted utilizing a unit cell model consisting of three concentric cylinders to determine the required character (i.e., thickness and mechanical properties) of the compliant layer as well as its applicability. The unknown compliant layer mechanical properties were expressed as ratios of the corresponding temperature dependent Ti-24Al-11Nb (a/o) matrix properties. The fiber properties taken were those corresponding to SCS-6 (SiC). Results indicated that the compliant layer can be used to reduce, if not eliminate, radial and circumferential residual stresses within the fiber and matrix and therefore also reduce or eliminate the radial cracking. However, with this decrease in in-plane stresses, one obtains an increase in longitudinal stress, thus potentially initiating longitudinal cracking. Guidelines are given for the selection of a specific compensating/compliant material, given a perfectly bonded system. C1 UNIV TOLEDO,TOLEDO,OH 43606. RP ARNOLD, SM (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 14 TC 27 Z9 31 U1 0 U2 0 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 9 BP 1287 EP 1309 DI 10.1177/002199839202600904 PG 23 WC Materials Science, Composites SC Materials Science GA JD059 UT WOS:A1992JD05900004 ER PT J AU BOWLES, KJ FRIMPONG, S AF BOWLES, KJ FRIMPONG, S TI VOID EFFECTS ON THE INTERLAMINAR SHEAR-STRENGTH OF UNIDIRECTIONAL GRAPHITE-FIBER-REINFORCED COMPOSITES SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE COMPOSITES; POLYMERS; FIBERS; MECHANICAL PROPERTIES; INTERLAMINAR SHEAR STRENGTH; VOID EFFECTS; DENSITY ID CFRP AB A study was conducted to evaluate the effect of voids on the interlaminar shear strength (ILSS) of a polyimide matrix composite system. The graphite/PMR-15 composite was chosen for study because of the extensive amount of experience that has been amassed in the processing of this material. Composite densities and fiber contents of more than 30 different laminates were measured along with interlaminar shear strengths. Void contents were calculated and the void geometry and distribution were noted using microscope techniques such as those used in metallography. A good empirical correlation between ILSS and composite density was found. However, the most acceptable relationship between the ILSS and density was found to be a power equation that closely resembles theoretically derived expressions. As the void content increased, an increase in scatter in the strength data was observed. In laminates with low void content, the voids appeared to be more segregated in one area of the laminate. We found that void-free composites could be processed in matched metal die molds at pressures greater than 1.4 MPa and less than 6.9 MPa. RP BOWLES, KJ (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 13 TC 117 Z9 131 U1 4 U2 35 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 10 BP 1487 EP 1509 DI 10.1177/002199839202601006 PG 23 WC Materials Science, Composites SC Materials Science GA JG971 UT WOS:A1992JG97100006 ER PT J AU FARLEY, GL JONES, RM AF FARLEY, GL JONES, RM TI CRUSHING CHARACTERISTICS OF COMPOSITE TUBES WITH NEAR-ELLIPTIC CROSS-SECTIONS SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article ID ENERGY-ABSORPTION AB An experimental investigation was conducted to determine whether the energy-absorption capability of near-elliptical cross-section composite tubular specimens is a function of included angle. Each half of the near-elliptical cross-section tube is a segment of a circle. The included angle is the angle created by radial lines extending from the center of the circular segment to the ends of the circular segment. Graphite- and Kevlar-reinforced epoxy material was used to fabricate specimens. Tube plv orientation was [+/- 45]N where the number of +/- 45 pairs was 2, 4, 6, and 12. Tube internal diameters were 2.54, 3.81, and 7.62 cm, and included angles were 180, 160, 135, 115, and 90 degrees. Based upon the test results from these tubes, energy-absorption capability increased between 10 and 30 percent as included angle decreased between 180 and 90 degrees for the materials evaluated. Energy-absorption capability was a decreasing nonlinear function of the ratio of tube internal diameter to wall thickness. C1 VIRGINIA POLYTECH INST & STATE UNIV,DEPT ENGN SCI & MECH,BLACKSBURG,VA 24061. RP FARLEY, GL (reprint author), USA,AVSCOM,AEROSTRUCT DIRECTORATE,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 15 TC 31 Z9 33 U1 1 U2 3 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 12 BP 1741 EP 1751 DI 10.1177/002199839202601203 PG 11 WC Materials Science, Composites SC Materials Science GA JM054 UT WOS:A1992JM05400003 ER PT J AU FARLEY, GL AF FARLEY, GL TI A MECHANISM RESPONSIBLE FOR REDUCING COMPRESSION STRENGTH OF THROUGH-THE-THICKNESS REINFORCED COMPOSITE-MATERIAL SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article AB A study was conducted to identify one of the mechanisms that contributes to the reduced compression strength of composite materials with through-the-thickness (TTT) reinforcements. In this study a series of thick [0/90] laminates with stitched and integrally woven TTT reinforcements were fabricated and statically tested. In both the stitching and weaving process a surface loop of TTT reinforcement yarn is created between successive TTT penetrations. It was shown that the surface loop of the TTT reinforcement "kinked" the in-plane fibers in such a manner that they were made ineffective in carrying compressive load. The improvement in strength by removal of the surface loop and "kinked" in-plane fibers was between 7 and 35 percent. RP FARLEY, GL (reprint author), USA,AVSCOM,AEROSTRUCT DIRECTORATE,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 13 TC 16 Z9 17 U1 1 U2 4 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 12 BP 1784 EP 1795 DI 10.1177/002199839202601206 PG 12 WC Materials Science, Composites SC Materials Science GA JM054 UT WOS:A1992JM05400006 ER PT J AU PROSSER, WH DORIGHI, J GORMAN, MR AF PROSSER, WH DORIGHI, J GORMAN, MR TI EXTENSIONAL AND FLEXURAL WAVES IN A THIN-WALLED GRAPHITE EPOXY TUBE SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE ACOUSTIC EMISSION; COMPOSITE CYLINDER; PLATE WAVES; LAMINATED PLATE THEORY ID PROPAGATION; COMPOSITE; PLATES AB Simulated acoustic emission signals were induced in a thin-walled graphite/epoxy tube by means of lead breaks (Hsu-Neilsen source). The tube is of similar material and layup to be used by NASA in fabricating the struts of Space Station Freedom. The resulting waveforms were detected by broad band ultrasonic transducers and digitized. Measurements of the velocities of the extensional and flexural modes were made for propagation directions along the tube axis (0 degrees), around the tube circumference (90 degrees) and at an angle of 45 degrees. These velocities were found to be in agreement with classical plate theory. C1 USN,SCH POSTGRAD,MONTEREY,CA 93940. RP PROSSER, WH (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 16 TC 11 Z9 11 U1 0 U2 1 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 14 BP 2016 EP 2027 DI 10.1177/002199839202601401 PG 12 WC Materials Science, Composites SC Materials Science GA JR989 UT WOS:A1992JR98900001 ER PT J AU JACKSON, KE KELLAS, S MORTON, J AF JACKSON, KE KELLAS, S MORTON, J TI SCALE EFFECTS IN THE RESPONSE AND FAILURE OF FIBER REINFORCED COMPOSITE LAMINATES LOADED IN TENSION AND IN FLEXURE SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article ID STRENGTH; EPOXY; CRACKING AB The feasibility of using scale model testing for predicting the full-scale behavior of flat composite coupons loaded in tension and beam-columns loaded in flexure is examined. Classical laws of similitude are applied to fabricate and test replica model specimens to identify scaling effects in the load response, strength, and mode of failure. Experiments were performed on graphite-epoxy composite specimens having different laminate stacking sequences and a range of scaled sizes. From the experiments it was deduced that the elastic response of scaled composite specimens was independent of size. However, a significant scale effect in strength was observed. In addition, a transition in failure mode was observed among scaled specimens of, certain laminate stacking sequences. A Weibull statistical model and a fracture mechanics based model were applied to predict the strength scale effect since standard failure criteria cannot account for the influence of absolute specimen size on strength. C1 LOCKHEED ENGN & SCI CO,HAMPTON,VA 23666. VIRGINIA POLYTECH INST & STATE UNIV,DEPT ENGN SCI & MECH,BLACKSBURG,VA 24061. RP JACKSON, KE (reprint author), USA,AEROSTRUCTURES DIRECTORATE,AVSCOM,NASA,LANGLEY RES CTR,MAIL STOP 495,HAMPTON,VA 23681, USA. NR 36 TC 35 Z9 35 U1 6 U2 9 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1992 VL 26 IS 18 BP 2674 EP 2705 DI 10.1177/002199839202601803 PG 32 WC Materials Science, Composites SC Materials Science GA KG871 UT WOS:A1992KG87100003 ER PT J AU CHEN, SK LEFEBVRE, AH ROLLBUHLER, J AF CHEN, SK LEFEBVRE, AH ROLLBUHLER, J TI FACTORS INFLUENCING THE EFFECTIVE SPRAY CONE ANGLE OF PRESSURE-SWIRL ATOMIZERS SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB The spray cone angles produced by several simplex pressure-swirl nozzles are examined using three liquids whose viscosities range from 0.001 to 0.012 kg/ms (1 to 12 cp). Measurements of both the visible spray cone angle and the effective spray cone angle are carried out over wide ranges of injection pressure and for five different values of the discharge orifice length/diameter ratio. The influence of the number of swirl chamber feed slots on spray cone angle is also examined. The results show that the spray cone angle widens with increase in injection pressure but is reduced by increases in liquid viscosity and/or discharge orifice length/diameter ratio. Variation in the number of swirl chamber feed slots between one and three has little effect on the effective spray cone angle. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP CHEN, SK (reprint author), PURDUE UNIV,CTR THERMAL SCI & PROP,W LAFAYETTE,IN 47907, USA. NR 12 TC 30 Z9 32 U1 0 U2 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1992 VL 114 IS 1 BP 97 EP 103 DI 10.1115/1.2906313 PG 7 WC Engineering, Mechanical SC Engineering GA HP743 UT WOS:A1992HP74300014 ER PT J AU FREED, AD RAJ, SV WALKER, KP AF FREED, AD RAJ, SV WALKER, KP TI STRESS VERSUS TEMPERATURE-DEPENDENCE OF ACTIVATION-ENERGIES FOR CREEP SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID DEFORMATION; COPPER AB The activation energy for creep at low stresses and elevated temperatures is associated with lattice diffusion, where the rate controlling mechanism for deformation is dislocation climb. At higher stresses and intermediate temperatures, the rate controlling mechanism changes from dislocation climb to obstacle-controlled dislocation glide. Along with this change in deformation mechanism occurs a change in the activation energy. When the rate controlling mechanism for deformation is obstacle-controlled dislocation glide, it is shown that a temperature-dependent Gibbs free energy does better than a stress-dependent Gibbs free energy in correlating steady-state creep data for both copper and LiF-22mol percent CaF2 hypereutectic salt. C1 ENGN SCI SOFTWARE INC,SMITHFIELD,RI. RP FREED, AD (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. OI Freed, Alan/0000-0002-3492-0628 NR 24 TC 13 Z9 13 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD JAN PY 1992 VL 114 IS 1 BP 46 EP 50 DI 10.1115/1.2904139 PG 5 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA HC693 UT WOS:A1992HC69300008 ER PT J AU NOUAILHAS, D FREED, AD AF NOUAILHAS, D FREED, AD TI A VISCOPLASTIC THEORY FOR ANISOTROPIC MATERIALS SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID CONSTITUTIVE-EQUATIONS; PLASTICITY AB The purpose of this work is the development of a unified, cyclic, viscoplastic model for anisotropic materials. The first part of the paper presents the foundations of the model in the framework of thermodynamics with internal variables. The second part considers the particular case of cubic symmetry, and addresses the cyclic behavior of a nickel-base single-crystal superalloy, CMSX-2, at high temperature (950-degrees-C). C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP NOUAILHAS, D (reprint author), OFF NATL ETUD & RECH AEROSP,F-92322 CHATILLON,FRANCE. NR 38 TC 20 Z9 20 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD JAN PY 1992 VL 114 IS 1 BP 97 EP 104 DI 10.1115/1.2904149 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA HC693 UT WOS:A1992HC69300017 ER PT J AU NOEVER, DA MATSOS, HC LOOGER, LL AF NOEVER, DA MATSOS, HC LOOGER, LL TI BIOCONVECTIVE INDICATORS IN TETRAHYMENA - NICKEL AND COPPER PROTECTION FROM CADMIUM POISONING SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-ENVIRONMENTAL SCIENCE AND ENGINEERING & TOXIC AND HAZARDOUS SUBSTANCE CONTROL LA English DT Article DE CADMIUM; BIOASSAY; NICKEL; COPPER; BIOCONVECTION; TETRAHYMENA-PYRIFORMIS ID PYRIFORMIS; TOXICITY; GROWTH; THERMOPHILA; BIOASSAY AB As a biological detector for cadmium toxicity, an assay using the motile response of the protozoa species, Tetrahymena pyriformis, has been described. The assay relies on macroscopic bioconvective patterns to score the toxic response, giving a sensitivity better than 1-mu-M and a toxicity threshold to 7-mu-M for Cd+2. Using pattern formation as the toxicity monitor, nickel and copper are investigated individually for toxic effects at low dosages without cadmium and for poison protection directly against cadmium. Both 0.01 mM Ni and 0.05 mM Cu show protective competition with cadmium and enhance pattern formation capabilities for 3-mu-M Cd+2. RP NOEVER, DA (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,BIOPHYS BRANCH,ES-76,HUNTSVILLE,AL 35812, USA. NR 26 TC 1 Z9 1 U1 1 U2 3 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1077-1204 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Environ. Sci. Eng. Toxic Hazard. Subst. Control PY 1992 VL A27 IS 2 BP 403 EP 417 PG 15 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA HG004 UT WOS:A1992HG00400006 ER PT J AU STABENAU, EK LANDRY, AM CAILLOUET, CW AF STABENAU, EK LANDRY, AM CAILLOUET, CW TI SWIMMING PERFORMANCE OF CAPTIVE-REARED KEMP RIDLEY SEA-TURTLES LEPIDOCHELYS-KEMPI (GARMAN) SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE LEPIDOCHELYS-KEMPI; LIMB AND VENTILATORY FREQUENCY; SEA TURTLE; SWIMMING CAPACITY ID CARETTA-CARETTA L; OFFSHORE MIGRATION; ORIENTATION AB Swimming performance of Kemp's ridley sea turtles Lepidochelys kempi (Garman) was evaluated over a 6-month period to determine whether an exercise regime increased swimming capacity in captive reared turtles. Three experimental treatments included: (1) turtles exercised twice weekly and exposed to a weekly stamina test; (2) turtles subjected only to a weekly stamina test; and (3) non-exercised controls exposed to a single stamina test at the end of the study. No statistically significant difference in swimming capacity was detected between treatments 1 and 2, although treatment 1 turtles achieved higher performance levels than those from treatment 2. However, treatment 1 turtles exhibited fewer breaths/min (BRM) and foreflipper strokes/min (FSM) during stamina tests than did treatment 2 turtles. In contrast, control turtles (treatment 3) were unable to achieve the minimum swimming performance level. These results indicate that the swimming performances of exercised turtles significantly improved during captive rearing. The possible effects of an exercise regime on post-release survival potential are discussed. C1 TEXAS A&M UNIV SYST,DEPT WILDLIFE & FISHERIES SCI,COLL STN,TX 77843. NOAA,NATL MARINE FISHERIES SERV,GALVESTON LAB,GALVESTON,TX 77550. NR 25 TC 3 Z9 3 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PY 1992 VL 161 IS 2 BP 213 EP 222 DI 10.1016/0022-0981(92)90098-U PG 10 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA JW892 UT WOS:A1992JW89200005 ER PT J AU KRZYNOWEK, J ULJUA, DS PANUNZIO, LJ MANEY, RS AF KRZYNOWEK, J ULJUA, DS PANUNZIO, LJ MANEY, RS TI FACTORS AFFECTING FAT, CHOLESTEROL, AND OMEGA-3-FATTY-ACIDS IN MAINE SARDINES SO JOURNAL OF FOOD SCIENCE LA English DT Article DE FISH; SARDINES; FAT; CHOLESTEROL; UNSATURATION ID FLESH AB Maine sardines harvested June, July, October, and November were analyzed for moisture, ash, fat, cholesterol, and fatty acids either as whole fish, raw dressed, steam precooked, and after canning in soy oil, menhaden oil, or in the liquid exuded after steam precooking (cookout liquid). Fat content ranged from 5% for juvenile herring sampled June and October to 11% in maturing herring harvested prior to the spawning season in July. All canning liquids contributed to elevated fat content in the finished product. Herring packed in soy oil or cookout liquid had about 90 mg cholesterol/100g samples. Herring packed in menhaden oil had 100-115 mg cholesterol/100g. Herring packed in either of the two fish oil solutions contained significantly more omega-3 fatty acids and had a greater ratio of omega-3:omega-6 than those packed in soy oil. RP KRZYNOWEK, J (reprint author), NATL MARINE FISHERIES SERV,LIPID ANALYT CHEM UNIT,GLOUCESTER LAB,30 EMERSON AVE,GLOUCESTER,MA 01930, USA. NR 18 TC 10 Z9 10 U1 0 U2 0 PU INST FOOD TECHNOLOGISTS PI CHICAGO PA SUITE 300 221 N LASALLE ST, CHICAGO, IL 60601-1291 SN 0022-1147 J9 J FOOD SCI JI J. Food Sci. PD JAN-FEB PY 1992 VL 57 IS 1 BP 63 EP & DI 10.1111/j.1365-2621.1992.tb05425.x PG 0 WC Food Science & Technology SC Food Science & Technology GA HD555 UT WOS:A1992HD55500016 ER PT J AU LANGEL, RA AF LANGEL, RA TI INTERNATIONAL GEOMAGNETIC REFERENCE FIELD - THE 6TH GENERATION SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article; Proceedings Paper CT 1991 ( 5TH ) REVISION OF THE INTERNATIONAL GEOMAGNETIC REFERENCE FIELD, AT THE 20TH GENERAL ASSEMBLY OF THE INTERNATIONAL UNION OF GEODESY AND GEOPHYSICS CY AUG, 1991 CL VIENNA, AUSTRIA SP INT UNION GEODESY & GEOPHYS ID MODELS AB In August 1991 the International Association of Geomagnetism and Aeronomy revised the International Geomagnetic Reference Field (IGRF) for the fifth time. This Sixth Generation IGRF now consists of 10 spherical harmonic models of the main geomagnetic field at five year intervals from 1945 through 1990 and a secular variation model extending the main field model of 1990 through 1995. For the interval 1945-1985 the models are definitive (DGRFs), in that it is unlikely that the underlying data sets will be significantly improved so there is no plan for future revision of the models. The present revision consists of adoption of a definitive main field model for 1985, DGRF 1985, a main field model for 1990 with secular variation coefficients for 1990-1995, IGRF 1990, and a provisional model, PGRF 1985, for 1985-1990 defined as the linear interpolation between DGRF 1985 and IGRF 1990. All main field models are of degree and order 10. The secular variation model is of degree and order 8. The models were derived from five candidate main field models at 1985, five at 1990, and three candidate secular variation models at epoch 1992.5. Weighted averages of the candidate models were specified to arrive at the final models. A brief description of the development of the IGRF is given, useful formulae are reviewed, and contour maps of the geomagnetic elements D, I, H, X, Y, Z, and F at 1990 are included. The nature of and philosophy behind the IGRF are discussed and a new procedure for deriving the IGRF is proposed. RP LANGEL, RA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,GREENBELT,MD 20771, USA. NR 47 TC 67 Z9 70 U1 0 U2 0 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 2003 SANSEI JIYUGAOKA HAIMU, 5-27-19 OKUSAWA, SETAGAYA-KU, TOKYO 158, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1992 VL 44 IS 9 BP 679 EP 707 PG 29 WC Geosciences, Multidisciplinary SC Geology GA KD182 UT WOS:A1992KD18200002 ER PT J AU LANGEL, RA SABAKA, TJ BALDWIN, RT AF LANGEL, RA SABAKA, TJ BALDWIN, RT TI THE GEOMAGNETIC-FIELD - 1970-1990 AND THE NASA CANDIDATE MODELS FOR DGRF1985 AND IGRF1990 SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article; Proceedings Paper CT 1991 ( 5TH ) REVISION OF THE INTERNATIONAL GEOMAGNETIC REFERENCE FIELD, AT THE 20TH GENERAL ASSEMBLY OF THE INTERNATIONAL UNION OF GEODESY AND GEOPHYSICS CY AUG, 1991 CL VIENNA, AUSTRIA SP INT UNION GEODESY & GEOPHYS ID SECULAR VARIATION; MAGNETIC-FIELD AB All available magnetic data from observatories, satellites, repeat station measurements, and aeromagnetic, shipborne and land surveys are used to derive spherical harmonic models of the geomagnetic field from 1970 to 1990. Two models are derived, one using data from the DE-2 satellite the other not, since the quality of that data is unknown. These models are designated GSFC(11/90)D and GSFC(11/90) respectively. Main field coefficients are determined up to degree 13 and temporal variation, represented by B-splines, up to degree 10. Bias values at the fixed observatories were included as part of the solution. The secular variation models are smoothed by use of norm minimization. Both models fit the data very well. The resulting secular variation shows a jerk-like trend change in several coefficients near 1979. Candidate DGRF 1985 and IGRF 1990 models are extracted from the more general models by projecting to the desired epoch and using a truncated version of the main field spherical harmonic coefficients at those epochs. C1 HUGHES STX CORP,LANHAM,MD 20706. RP LANGEL, RA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,GREENBELT,MD 20771, USA. RI Sabaka, Terence/D-5618-2012 NR 17 TC 6 Z9 6 U1 0 U2 0 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 2003 SANSEI JIYUGAOKA HAIMU, 5-27-19 OKUSAWA, SETAGAYA-KU, TOKYO 158, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1992 VL 44 IS 9 BP 745 EP 767 PG 23 WC Geosciences, Multidisciplinary SC Geology GA KD182 UT WOS:A1992KD18200006 ER PT J AU LANGEL, RA BALDWIN, RT AF LANGEL, RA BALDWIN, RT TI COMPARISON OF CANDIDATE MODELS FOR DGRF85 AND IGRF90 SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article; Proceedings Paper CT 1991 ( 5TH ) REVISION OF THE INTERNATIONAL GEOMAGNETIC REFERENCE FIELD, AT THE 20TH GENERAL ASSEMBLY OF THE INTERNATIONAL UNION OF GEODESY AND GEOPHYSICS CY AUG, 1991 CL VIENNA, AUSTRIA SP INT UNION GEODESY & GEOPHYS ID FIELD; MAGSAT AB Candidate models were submitted to IAGA Working group V-8 for DGRF 1985 and IGRF 1990. Main field candidates were of degree 10 for each epoch and the 1990 models included secular variation models of degree 8. Two main field candidates for each epoch were submitted by NASA's Goddard Space Flight Center (GSFC), one with and one without DE-2 satellite data. One candidate model for each epoch was submitted by the U.S. Geological Survey (USGS), one by the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Moscow (IZMIRAN), and one jointly by the British Geological Survey (BGS) and the U.S. Naval Oceanographic Office (NOO). All 1990 models except those from GSFC included a secular variation model for 1990-1995. All models used data from Magsat and from the magnetic observatories. These were the only data used in the IZMIRAN model. All other models used Project Magnet data, but only the GSFC and USGS models incorporated it into their secular variation models. Only the GSFC models made use of the ground survey and marine survey data sets. The GSFC models also incorporated a small amount of Project Magnet data from 1988-89 which was not used in the other models. Each candidate was compared against available data from magnetic observatories, repeat, and the various surveys. The results are comparable for all the models, no model is dramatically better or worse in its representation of the data. When comparing the models to one another, the two GSFC models are very similar. Of the others, the USGS and GSFC models are more "alike" than other pairs of models and the IZMIRAN models are the most "different". For any pair of models the largest differences are located where the data are most sparse, i.e. the southern hemisphere and the oceanic regions. The trends of the coefficients and the implied secular variation are nearly identical between the models and the secular variation is consistent with the secular variation trend of the past 15 years. C1 HUGHES STX CORP,LANHAM,MD 20706. RP LANGEL, RA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,GREENBELT,MD 20771, USA. NR 21 TC 2 Z9 2 U1 0 U2 0 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 2003 SANSEI JIYUGAOKA HAIMU, 5-27-19 OKUSAWA, SETAGAYA-KU, TOKYO 158, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1992 VL 44 IS 9 BP 805 EP 842 PG 38 WC Geosciences, Multidisciplinary SC Geology GA KD182 UT WOS:A1992KD18200009 ER PT J AU MURAYAMA, Y OYAMA, KI TSUDA, T KANZAWA, H SCHMIDLIN, FJ BITTNER, M NAKAMURA, T YAMANAKA, MD FUKAO, S KATO, S AF MURAYAMA, Y OYAMA, KI TSUDA, T KANZAWA, H SCHMIDLIN, FJ BITTNER, M NAKAMURA, T YAMANAKA, MD FUKAO, S KATO, S TI ROCKETSONDE OBSERVATIONS OF THE MIDDLE ATMOSPHERE DYNAMICS AT UCHINOURA (31-DEGREES-N, 131-DEGREES-E) DURING THE DYANA CAMPAIGN .1. OUTLINE OF EXPERIMENTS AND BACKGROUND CONDITIONS SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article ID RADAR AB We describe in this paper preliminary results on the characteristics of the wind velocity and temperature profiles obtained through rocketsonde measurements during the DYANA campaign. The wind velocity profiles in the height region of 20-90 km, obtained with the rocketsondes, were compared with the results simultaneously observed with the MU (middle and upper atmosphere) radar at 60-100 km. The profiles were consistent with each other up to 80 km, when they were smoothed out for a height range of 8 km. While for wind velocity fluctuations with vertical scales of a few km, the rocketsonde results showed significantly larger amplitudes than those obtained with the MU radar above 60 km. Consideration of the vertical wavenumber spectra of the wind velocity fluctuations suggested that the maximum height range of the rocketsonde profile, by which the gravity wave characteristics can be delineated, seemed to be limited only up to about 60 km. The background zonal winds were westward in the stratosphere, but they exhibited large time variations, coinciding with a minor stratospheric sudden warming. The temperature profiles also indicated great variability near the stratopause and in the mesosphere, probably due to the effect of the enhanced activity of planetary waves. C1 INST SPACE & ASTRONAUT SCI,SAGAMIHARA,KANAGAWA 229,JAPAN. NATL INST POLAR RES,ITABASHI KU,TOKYO 173,JAPAN. UNIV GESAMTHSCH WUPPERTAL,DEPT PHYS,W-5600 WUPPERTAL 1,GERMANY. NASA,GODDARD SPACE FLIGHT CTR,WALLOPS FLIGHT FACIL,GREENBELT,MD 20771. RP MURAYAMA, Y (reprint author), KYOTO UNIV,CTR RADIO ATMOSPHER SCI,UJI,KYOTO 611,JAPAN. RI Yamanaka, Manabu/E-5671-2011; tsuda, toshitaka/A-3035-2015; OI Murayama, Yasuhiro/0000-0003-1129-334X NR 15 TC 7 Z9 8 U1 0 U2 1 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 302 JIYUGAOKA-KOMATSU BLDG 24-17 MIDORIGAOKA 2-CHOME, TOKYO TOKYO 152, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1992 VL 44 IS 11 BP 995 EP 1007 PG 13 WC Geosciences, Multidisciplinary SC Geology GA KH060 UT WOS:A1992KH06000003 ER PT J AU TSUDA, T MURAYAMA, Y OYAMA, KI SCHMIDLIN, FJ BITTNER, M KANZAWA, H NAKAMURA, T YAMANAKA, MD FUKAO, S KATO, S AF TSUDA, T MURAYAMA, Y OYAMA, KI SCHMIDLIN, FJ BITTNER, M KANZAWA, H NAKAMURA, T YAMANAKA, MD FUKAO, S KATO, S TI ROCKETSONDE OBSERVATIONS OF THE MIDDLE ATMOSPHERE DYNAMICS AT UCHINOURA (31-DEGREES-N, 131-DEGREES-E) DURING THE DYANA CAMPAIGN .2. CHARACTERISTICS OF GRAVITY-WAVES SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article ID UNIVERSAL SPECTRUM; LOWER STRATOSPHERE; RAYLEIGH LIDAR; SATURATION; MESOSPHERE; CLIMATOLOGY; PROFILES; RADAR AB We describe in this paper the height variations of the gravity wave characteristics in the middle atmosphere, using the profiles of wind velocity and temperature collected at 20-90 km altitude by means of a series of rocketsonde experiments and the MU (middle and upper atmosphere) radar during the DYANA campaign. The dominant vertical scales of the wind velocity fluctuations generally increased with altitude from 2-3 km in the lower stratosphere to 10-15 km in the mesosphere. The vertical wavenumber spectra of the wind velocity fluctuations, constructed in five altitude regions, showed height variations in the spectral shape, which was fairly consistent with the model spectrum based upon the saturation of gravity waves. The wind velocity variance due to gravity waves generally increased in the stratosphere, diminished just above the stratopause, greatly increased again in the lower mesosphere, and finally became nearly constant in the upper mesosphere above about 65 km. The gravity waves with relatively small vertical scales were significantly weakened just above the stratopause, suggesting the important effect of the vertical structure of the static stability on the propagation characteristics of gravity waves. C1 INST SPACE & ASTRONAUT SCI,SAGAMIHARA,KANAGAWA 229,JAPAN. NATL INST POLAR RES,ITABASHI KU,TOKYO 173,JAPAN. NASA,GODDARD SPACE FLIGHT CTR,WALLOPS FLIGHT FACIL,GREENBELT,MD 20771. UNIV GESAMTHSCH WUPPERTAL,DEPT PHYS,W-5600 WUPPERTAL 1,GERMANY. RP TSUDA, T (reprint author), KYOTO UNIV,CTR RADIO ATMOSPHER SCI,UJI,KYOTO 611,JAPAN. RI Yamanaka, Manabu/E-5671-2011; tsuda, toshitaka/A-3035-2015 NR 22 TC 17 Z9 17 U1 0 U2 5 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 302 JIYUGAOKA-KOMATSU BLDG 24-17 MIDORIGAOKA 2-CHOME, TOKYO TOKYO 152, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1992 VL 44 IS 11 BP 1009 EP 1023 PG 15 WC Geosciences, Multidisciplinary SC Geology GA KH060 UT WOS:A1992KH06000004 ER PT J AU STERN, DP AF STERN, DP TI THE LINKAGE BETWEEN THE IONOSPHERE AND THE PLASMA SHEET SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article ID FIELD-ALIGNED CURRENTS; ELECTRIC-FIELD; CONVECTION; MAGNETOSPHERE; MOTION; TRIAD; MODEL AB The mapping of field lines by the Tsyganenko 1987 model suggests that the footpoints of field lines from the plasma sheet lie along the auroral oval: midnight maps to midnight in the oval, and as one progresses towards the flanks of the tail the footpoints advance towards the cusps. The oval also matches or parallels regions of Birkeland currents, the major electrodynamic link between the magnetosphere and the ionosphere. Region 2 currents are due to the interaction of the electric field E and trapped plasma, and are fairly well understood, but the primary system is that of region 1 and its theory is still incomplete. Near noon region 1 currents may extend to the solar wind or to boundary layers adjoining the magnetopause, but at night they map to the plasma sheet. A simple mechanism accounts for the latter currents: if the sheet contains a dawn-to-dusk E, it will try to impose its potentials on the ionosphere, a process which requires currents. The removal of such currents from the tail, however, must leave charge neutrality intact, and must also satisfy the Vasyliunas equation. The latter requires the pressure p2 in the midnight sector of the plasma sheet to be less than the pressure p1 near the flanks. A mechanism for establishing such a pressure profile is discussed. but the problem is essentially still unsolved. RP STERN, DP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,CODE 695,GREENBELT,MD 20771, USA. NR 29 TC 8 Z9 8 U1 0 U2 2 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 302 JIYUGAOKA-KOMATSU BLDG 24-17 MIDORIGAOKA 2-CHOME, TOKYO TOKYO 152, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1992 VL 44 IS 12 BP 1109 EP 1120 PG 12 WC Geosciences, Multidisciplinary SC Geology GA KR076 UT WOS:A1992KR07600001 ER PT J AU SHARBER, JR HONES, EW HEELIS, RA CRAVEN, JD FRANK, LA MAYNARD, NC SLAVIN, JA BIRN, J AF SHARBER, JR HONES, EW HEELIS, RA CRAVEN, JD FRANK, LA MAYNARD, NC SLAVIN, JA BIRN, J TI DYNAMICS EXPLORER MEASUREMENTS OF PARTICLES, FIELDS, AND PLASMA DRIFTS OVER A HORSE-COLLAR AURORAL PATTERN SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; POLAR-CAP; CONVECTION PATTERNS; THETA-AURORA; NORTHWARD; MODEL; ARCS; IMF; MAGNETOSPHERE; CURRENTS AB As shown from ground-based measurements and satellite-borne imagers, one type of global auroral pattern characteristic of quiet (usually northward IMF) intervals is that of a contracted but thickened emission region in which the dawn and dusk portions can spread poleward to very high latitudes. Because of its shape, such a pattern has been referred to as a ''horse-collar'' aurora (HONEs et al., 1989). In this report we use the Dynamics Explorer data set to examine a case in which this ''horse-collar'' pattern was observed by the DE-1 auroral imager while at the same time DE-2, at lower altitude, measured precipitating particles, electric and magnetic fields, and plasma drifts. Our analysis shows that in general there is close agreement between the optical signatures and the particle precipitation patterns. In many instances, over scales ranging from tens to a few hundred kilometers, electron precipitation features and upward field-aligned currents are observed at locations where the plasma flow gradients indicate negative del.E. The particle, plasma, and field measurements made along the satellite track and the 2-D perspective of the imager provide a means of determining the configuration of convective flows in the high-latitude ionosphere during this interval of northward IMF. Recent mapping studies are used to relate the low-altitude observations to possible magnetospheric source regions. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV TEXAS,RICHARDSON,TX 75083. UNIV ALASKA,FAIRBANKS,AK 99775. UNIV IOWA,IOWA CITY,IA 52242. PHILLIPS LAB,BEDFORD,MA 01731. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP SHARBER, JR (reprint author), SOUTHWEST RES INST,SAN ANTONIO,TX 78228, USA. RI Slavin, James/H-3170-2012 OI Slavin, James/0000-0002-9206-724X NR 21 TC 3 Z9 3 U1 0 U2 3 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 302 JIYUGAOKA-KOMATSU BLDG 24-17 MIDORIGAOKA 2-CHOME, TOKYO TOKYO 152, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1992 VL 44 IS 12 BP 1225 EP 1237 PG 13 WC Geosciences, Multidisciplinary SC Geology GA KR076 UT WOS:A1992KR07600009 ER PT J AU NAKAMURA, R YAMAMOTO, T AF NAKAMURA, R YAMAMOTO, T TI SUBSTORM-ASSOCIATED CHANGES IN THE PARTICLE-PRECIPITATION PATTERN SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article ID ION PRECIPITATION; CURRENT SHEET; MLT SECTOR; MAGNETOTAIL; DIVERSION; AURORAS; GROWTH; TAIL AB Relationships between average characteristics of particle precipitation and substorm activity are investigated in the low latitude region as well as in the high latitude region within the dusk-to-midnight sector. ''Low latitude'' is defined here as the region below the equatorward boundary of the most equatorward electron BPS, while ''high latitude'' is defined as the region higher than that boundary. DMSP particle data are divided according to the phase of the substorm and according to the longitude with respect to the onset region by referring to ground-based magnetograms and DMSP auroral images. At high latitude, not only electron precipitation but also ion precipitation significantly intensifies in accordance with substorm activity. The energization of these particles presumably takes place in the near-tail region where an unstable tail current develops and locally diverges associated with substorm onset. At low latitude, temporal and spatial changes of energetic precipitation would be caused by injected, drifting particles from the substorm onset regions, particularly in the case of electrons. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. INST SPACE & ASTR SCI,SAGAMIHARA,KANAGAWA 229,JAPAN. RP NAKAMURA, R (reprint author), NATL INST POLAR RES,ITABASHI KU,TOKYO 173,JAPAN. RI Nakamura, Rumi/I-7712-2013 OI Nakamura, Rumi/0000-0002-2620-9211 NR 22 TC 1 Z9 1 U1 0 U2 1 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 302 JIYUGAOKA-KOMATSU BLDG 24-17 MIDORIGAOKA 2-CHOME, TOKYO TOKYO 152, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1992 VL 44 IS 12 BP 1239 EP 1249 PG 11 WC Geosciences, Multidisciplinary SC Geology GA KR076 UT WOS:A1992KR07600010 ER PT J AU HOYT, DV KYLE, HL HICKEY, JR MASCHHOFF, RH AF HOYT, DV KYLE, HL HICKEY, JR MASCHHOFF, RH TI THE NIMBUS 7 SOLAR TOTAL IRRADIANCE - A NEW ALGORITHM FOR ITS DERIVATION SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTH AB The Nimbus 7 satellite has measured the solar total irradiance from November 1978 to July 1991 (153 months). These measurements are important both in solar physics and for climate change. To insure that the Nimbus 7 measurements are capturing the true behavior of the Sun, it is essential that the properties of the radiometer and its changes over time be understood. The calibration of the radiometer can be viewed as a process of removing instrumental influences from the raw measurements, leaving the experimenter with an estimate of solar variability. In this paper the changing radiometer pointing, the zero offsets. the stability of the gain, the temperature sensitivity, and the influences of other platform instruments are all examined and their effects on the measurements considered. Only the question of relative accuracy (not absolute) is examined. The resulting derived solar irradiances are compared to previous analyses of the Nimbus 7 radiometer and to the Solar Maximum Mission (SMM) measurements. Compared to previous analyses, the newly derived values are higher and somewhat less variable than the older values. Removal of the off-axis pointing errors and a new treatment of the zero offsets are the major reasons for the changes. Compared to the SMM measurements, both agree quite well so long as any solar activity is present. When the Sun becomes quiet, so its irradiance variability is less than the Nimbus 7 radiometer resolution, the comparison to the SMM results breaks down. Between 1980 and 1988 the correlation of the daily values is 0.83, compared to 0.62 using previously published values from both satellites. The monthly means have a correlation of 0.90, indicating that about 80% of the longer-term variance is in common. In 1980 when both satellites were operating without problems. Nimbus 7 was 0.3155% higher on average. For May 1984 to December 1988, Nimbus 7 was 0.3255% higher. Therefore if the Nimbus 7 satellite continues to operate properly until a period of about 1 year after the launch of UARS with its active cavity radiometer irradiance monitor (ACRIM), it appears that the differences between Nimbus 7, SMM ACRIM, and UARS ACRIM can be measured to within a few hundredths of a percent. A self-consistent set of solar irradiance measurements from several satellites over nearly two solar cycles appears feasible. C1 EPPLEY LAB INC,NEWPORT,RI 02840. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. GULTON IND,DIV DATA SYST,ALBUQUERQUE,NM 87190. RP HOYT, DV (reprint author), RES & DATA SYST CORP,7855 WALKER DR,SUITE 460,GREENBELT,MD 20770, USA. NR 11 TC 99 Z9 100 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1992 VL 97 IS A1 BP 51 EP 63 DI 10.1029/91JA02488 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GY568 UT WOS:A1992GY56800005 ER PT J AU WILLETT, JB MAHONEY, WA AF WILLETT, JB MAHONEY, WA TI HIGH SPECTRAL RESOLUTION MEASUREMENT OF GAMMA-RAY LINES FROM THE EARTHS ATMOSPHERE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GERMANIUM DETECTORS; SPECTROMETER; RADIATION AB A search for gamma ray line features from the Earth's atmosphere has been conducted using data from the third High Energy Astronomy Observatory (HEAO 3) high spectral resolution gamma ray spectrometer. In addition to the strong line at 0.511 MeV, other intrinsically broadened line features have been observed at 1.63, 2.31, 3.67, 4.43, 5.09, and 6.13 MeV. Since the spectral resolution of the instrument is much finer than the width of the observed line features, the intrinsic width as well as the energy and intensity of each of these lines are reported. Several other predicted lines have also been observed. The characteristics of the lines seen by HEAO 3 are generally consistent with theoretical predictions as well as with previous measurements. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP WILLETT, JB (reprint author), NASA,SPACE PHYS CODE SS,600 INDEPENDENCE AVE SW,WASHINGTON,DC 20546, USA. NR 22 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1992 VL 97 IS A1 BP 131 EP 139 DI 10.1029/91JA02434 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GY568 UT WOS:A1992GY56800012 ER PT J AU ZHAO, XM SHIEH, LS SUNKEL, JW YUAN, ZZ AF ZHAO, XM SHIEH, LS SUNKEL, JW YUAN, ZZ TI SELF-TUNING CONTROL OF ATTITUDE AND MOMENTUM MANAGEMENT FOR THE SPACE STATION SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID ADAPTIVE-CONTROL; SYSTEMS; REGULATORS AB This paper presents a hybrid state-space self-tuning design methodology using dual-rate sampling for suboptimal digital adaptive control of attitude and momentum management for the Space Station. This new hybrid adaptive control scheme combines an on-line recursive estimation algorithm for indirectly identifying the parameters of a continuous-time system from the available fast-rate sampled data of the inputs and states and a controller synthesis algorithm for indirectly finding the slow-rate suboptimal digital controller from the designed optimal analog controller. The proposed method enables the development of digitally implementable control algorithms for the robust control of Space Station Freedom with unknown environmental disturbances and slowly time-varying dynamics C1 NASA,LYNDON B JOHNSON SPACE CTR,DIV NAVIGAT CONTROL & AERONAUT,HOUSTON,TX 77058. UNIV NANKAI,DEPT COMP & SYST SCI,TIANJIN 300071,PEOPLES R CHINA. RP ZHAO, XM (reprint author), UNIV HOUSTON,DEPT ELECT ENGN,HOUSTON,TX 77204, USA. NR 16 TC 7 Z9 7 U1 1 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 1992 VL 15 IS 1 BP 17 EP 27 PG 11 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA GZ897 UT WOS:A1992GZ89700002 ER PT J AU LIM, KB AF LIM, KB TI METHOD FOR OPTIMAL ACTUATOR AND SENSOR PLACEMENT FOR LARGE FLEXIBLE STRUCTURES SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID LINEAR-SYSTEMS; CONTROLLABILITY; OBSERVABILITY AB A method of finding the optimal sensor and actuator locations for the control of flexible structures is presented. The method is based on the orthogonal projection of structural modes into the intersection subspace of the controllable and observable subspaces corresponding to an actuator/sensor pair. The controllability and observability grammians are then used to weight the projections to reflect the degrees of controllability and observability. This method produces a three-dimensional design space wherein sets of optimal actuators and sensors may be selected. A novel parameter is introduced that is potentially useful for studying the problem of the number of actuators and sensors, in addition to their optimal locations. RP LIM, KB (reprint author), NASA,LANGLEY RES CTR,SPACECRAFT CONTROLS BRANCH,DIV GUIDANCE & CONTROL,MAIL STOP 230,HAMPTON,VA 23665, USA. NR 9 TC 96 Z9 103 U1 1 U2 9 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 1992 VL 15 IS 1 BP 49 EP 57 DI 10.2514/3.20800 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA GZ897 UT WOS:A1992GZ89700006 ER PT J AU CHEN, CW HUANG, JK PHAN, M JUANG, JN AF CHEN, CW HUANG, JK PHAN, M JUANG, JN TI INTEGRATED SYSTEM-IDENTIFICATION AND STATE ESTIMATION FOR CONTROL OF FLEXIBLE SPACE STRUCTURES SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article AB A novel approach is developed for identification of a state-space model and a Kalman filter gain from input and output data. There are four steps involved in this approach. First, the relation between a stochastic state-space model of a dynamical system and the coefficients of its autoregressive model with exogeneous input is derived. Second, an adaptive least-squares transversal predictor is used to estimate the coefficients of the model. Third, a state-space model and a steady-state Kalman filter gain of the dynamical system are then identified from the coefficients of the model by using the eigensystem realization algorithm. Fourth, a modal state estimator is constructed using the modal parameters of the identified model. On-line implementation of this algorithm can continually improve the modal parameters and the filter gain. It can also gradually update the system model when the system characteristics are slowly changing. Numerical examples are used to illustrate the feasibility of the new approach. C1 NASA,LANGLEY RES CTR,SPACECRAFT DYNAM BRANCH,HAMPTON,VA 23665. RP CHEN, CW (reprint author), OLD DOMINION UNIV,DEPT MECH ENGN & MECH,NORFOLK,VA 23529, USA. NR 19 TC 38 Z9 38 U1 1 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 1992 VL 15 IS 1 BP 88 EP 95 DI 10.2514/3.20805 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA GZ897 UT WOS:A1992GZ89700011 ER PT J AU SULLA, JL JUANG, JN HORTA, LG AF SULLA, JL JUANG, JN HORTA, LG TI USE OF A VELOCITY COMMAND MOTOR AS A REACTION MASS ACTUATOR SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article AB This paper presents results of a test application of a commercially available linear step motor as a reaction mass actuator. The system equations with velocity command actuator dynamics are derived. Differences between a velocity command actuator and a force command actuator are discussed. A beam structure and the NASA Mini-Mast were used for vibration suppression experiments. Simulation results and analysis including filter dynamics are given to verify the experimental performance in terms of transient responses and augmented damping level. C1 NASA,LANGLEY RES CTR,SPACECRAFT DYNAM BRANCH,HAMPTON,VA 23665. RP SULLA, JL (reprint author), LOCKHEED ENGN & SCI CO,HAMPTON,VA 23665, USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 1992 VL 15 IS 1 BP 159 EP 164 DI 10.2514/3.20814 PG 6 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA GZ897 UT WOS:A1992GZ89700020 ER PT J AU FRIESEN, LJ JACKSON, AA ZOOK, HA KESSLER, DJ AF FRIESEN, LJ JACKSON, AA ZOOK, HA KESSLER, DJ TI RESULTS IN ORBITAL EVOLUTION OF OBJECTS IN THE GEOSYNCHRONOUS REGION SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID GEOSTATIONARY AB The orbital evolution of objects at or near geosynchronous orbit (GEO) has been simulated to investigate possible hazards to working geosynchronous satellites. Both large satellites and small particles have been simulated, subject to perturbations by nonspherical geopotential terms, lunar and solar gravity, and solar radiation pressure. Large satellites in initially circular orbits show an expected cycle of inclination change driven by lunar and solar gravity but very little altitude change. They have little chance of colliding with objects at other altitudes, provided that the initial eccentricities of their orbits are small. However, if such a satellite is disrupted, debris can reach thousands of kilometers above or below the initial satellite altitude. Small particles in GEO experience two cycles driven by solar radiation: an expected eccentricity cycle and an unexpected inclination cycle. This inclination cycle results from a precession of the orbit plane driven by asymmetric torque effects of the radiation pressure on an eccentric orbit. Particles generated by GEO insertion stage solid rocket motors typically hit the Earth or escape promptly; a small fraction remain in orbits that persist longer than 10 years. C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. RP FRIESEN, LJ (reprint author), LOCKHEED ENGN & SCI CO,MAIL CODE B12,2400 NASA RD 1,HOUSTON,TX 77058, USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 1992 VL 15 IS 1 BP 263 EP 267 DI 10.2514/3.20827 PG 5 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA GZ897 UT WOS:A1992GZ89700033 ER PT J AU GWALTNEY, DA GREENE, ME AF GWALTNEY, DA GREENE, ME TI GROUND-BASED IMPLEMENTATION AND VERIFICATION OF CONTROL LAWS FOR TETHERED SATELLITES SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Note C1 AUBURN UNIV,DEPT ELECT ENGN,AUBURN,AL 36849. RP GWALTNEY, DA (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 7 TC 3 Z9 3 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 1992 VL 15 IS 1 BP 271 EP 273 DI 10.2514/3.20829 PG 3 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA GZ897 UT WOS:A1992GZ89700035 ER PT J AU GREGORY, JC PETERS, PN AF GREGORY, JC PETERS, PN TI MEASUREMENT OF THE PASSIVE ATTITUDE-CONTROL PERFORMANCE OF A RECOVERED SPACECRAFT SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Note C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812. RP GREGORY, JC (reprint author), UNIV ALABAMA,DEPT CHEM,HUNTSVILLE,AL 35899, USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 1992 VL 15 IS 1 BP 282 EP 284 DI 10.2514/3.20834 PG 3 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA GZ897 UT WOS:A1992GZ89700040 ER PT J AU NOEVER, DA AF NOEVER, DA TI STATISTICS OF EXPANDING GEL SURFACE PATTERNS SO JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS LA English DT Article ID PHASE-TRANSITION; MONOLAYERS; CELLS; SOAP RP NOEVER, DA (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,ES-76,HUNTSVILLE,AL 35812, USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 0022-2348 J9 J MACROMOL SCI PHYS JI J. Macromol. Sci.-Phys. PY 1992 VL B31 IS 3 BP 357 EP 364 DI 10.1080/00222349208215521 PG 8 WC Polymer Science SC Polymer Science GA JC597 UT WOS:A1992JC59700006 ER PT J AU WAHLQUIST, HD AF WAHLQUIST, HD TI THE PROBLEM OF EXACT INTERIOR SOLUTIONS FOR ROTATING RIGID BODIES IN GENERAL-RELATIVITY SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID PERFECT FLUID; SPACE-TIMES; STATIONARY; TRANSFORMATIONS; EQUATIONS AB The (3 + 1) dyadic formalism for timelike congruences is applied to derive interior solutions for stationary, axisymmetric, rigidly rotating bodies. In this approach the mathematics is formulated in terms of three-space-covariant, first-order, vector-dyadic, differential equations for a and OMEGA, the acceleration and angular velocity three-vectors of the rigid body; for T, the stress dyadic of the matter; and for A and B, the "electric" and "magnetic" Weyl curvature dyadics which describe the gravitational field. In the paper it is shown how an appropriate ansatz for the forms of these dyadics can be used to discover exact rotating interior solutions such as the perfect fluid solution first published in 1968. By incorporating anisotropic stresses, a generalization is found of that previous solution and, in addition, a very simple new solution that can only exist in toroidal configurations. RP WAHLQUIST, HD (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 48 TC 17 Z9 17 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD JAN PY 1992 VL 33 IS 1 BP 304 EP 335 DI 10.1063/1.529965 PG 32 WC Physics, Mathematical SC Physics GA GW248 UT WOS:A1992GW24800036 ER PT J AU MISHRA, SK AJELLO, L AHEARN, DG BURGE, HA KURUP, VP PIERSON, DL PRICE, DL SAMSON, RA SANDHU, RS SHELTON, B SIMMONS, RB SWITZER, KF AF MISHRA, SK AJELLO, L AHEARN, DG BURGE, HA KURUP, VP PIERSON, DL PRICE, DL SAMSON, RA SANDHU, RS SHELTON, B SIMMONS, RB SWITZER, KF TI ENVIRONMENTAL MYCOLOGY AND ITS IMPORTANCE TO PUBLIC-HEALTH SO JOURNAL OF MEDICAL AND VETERINARY MYCOLOGY LA English DT Article; Proceedings Paper CT 11TH CONGRESS OF THE INTERNATIONAL SOC FOR HUMAN AND ANIMAL MYCOLOGY CY JUN 24-28, 1991 CL MONTREAL, CANADA SP INT SOC HUMAN & ANIM MYCOL ID INDOOR AIR-POLLUTION; BIPOLARIS-HAWAIIENSIS; HYPERSENSITIVITY PNEUMONITIS; DRECHSLERA-HAWAIIENSIS; AIRBORNE PENICILLIUM; BIOLOGICAL AEROSOLS; FUNGAL SINUSITIS; XEROPHILIC FUNGI; PHAEOHYPHOMYCOSIS; ENUMERATION C1 CENT BUR SCHIMMELCULTURES,BAARN,NETHERLANDS. GURU NANAK DEV ENGN COLL,AMRITSAR 143005,PUNJAB,INDIA. PATHOL LABS,NORCROSS,GA. MED COLL WISCONSIN,MILWAUKEE,WI 53226. VET ADM MED CTR,MILWAUKEE,WI. INTERFACE RES CORP,KENNESAW,CA. EMORY UNIV,ATLANTA,GA 30322. GEORGIA STATE UNIV,ATLANTA,GA 30303. UNIV MICHIGAN,ANN ARBOR,MI 48109. RP MISHRA, SK (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,KRUG,MICROBIOL LABS,BIOMED OPERAT & RES BRANCH,SD-4,HOUSTON,TX 77058, USA. NR 97 TC 40 Z9 42 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0268-1218 J9 J MED VET MYCOL JI J. Med. Vet. Mycol. PY 1992 VL 30 SU 1 BP 287 EP 305 PG 19 WC Mycology SC Mycology GA KC681 UT WOS:A1992KC68100029 PM 1474454 ER PT J AU MOLINA, TC MISHRA, SK PIERSON, DL AF MOLINA, TC MISHRA, SK PIERSON, DL TI A MICROFERMENTATION TEST FOR THE RAPID IDENTIFICATION OF YEASTS SO JOURNAL OF MEDICAL AND VETERINARY MYCOLOGY LA English DT Note AB The accuracy and speed of a microfermentation test (MFT), developed as a supplementary aid to other yeast identification systems, were compared with the conventional fermentation method in identifying 15 yeast species. The MFT significantly reduced the incubation period required to obtain a definitive identification. The method is easy to perform and the media and space requirements are minimal. C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. RP MOLINA, TC (reprint author), KRUG LIFE SCI,MICROBIOL LAB,BIOMED OPERAT & RES BRANCH,1290 HERCULES DR,SUITE 120,HOUSTON,TX 77058, USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0268-1218 J9 J MED VET MYCOL JI J. Med. Vet. Mycol. PY 1992 VL 30 IS 4 BP 323 EP 326 PG 4 WC Mycology SC Mycology GA JT474 UT WOS:A1992JT47400008 PM 1432492 ER PT J AU SASADA, H ENDO, Y HIROTA, E POYNTER, RL MARGOLIS, JS AF SASADA, H ENDO, Y HIROTA, E POYNTER, RL MARGOLIS, JS TI MICROWAVE AND FOURIER-TRANSFORM INFRARED-SPECTROSCOPY OF THE NU-4=1 AND NU-2=2S STATES OF NH3 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID SUBMILLIMETER-WAVE SPECTRUM; LASER-STARK SPECTROSCOPY; FORBIDDEN TRANSITIONS; ENERGY-LEVELS; CO LASER; (NH3)-N-14; CORIOLIS; BAND; NU-4-BAND; MOLECULES C1 INST MOLEC SCI,OKAZAKI,AICHI 444,JAPAN. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP SASADA, H (reprint author), KEIO UNIV,FAC SCI & TECHNOL,DEPT PHYS,14-1 HIYOSHI 3-CHOME,KOHOKU KU,YOKOHAMA,KANAGAWA 223,JAPAN. NR 21 TC 39 Z9 38 U1 0 U2 6 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JAN PY 1992 VL 151 IS 1 BP 33 EP 53 DI 10.1016/0022-2852(92)90005-9 PG 21 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA GV793 UT WOS:A1992GV79300004 ER PT J AU LANE, HW AF LANE, HW TI ENERGY-REQUIREMENTS FOR SPACE-FLIGHT SO JOURNAL OF NUTRITION LA English DT Review DE SPACE; HUMANS; ENERGY UTILIZATION; RESPIRATORY QUOTIENT; LEAN BODY MASS AB Both the United States and the Soviet Union perform human space research. This paper reviews data available on energy metabolism in the microgravity of space flight. The level of energy utilization in space seems to be similar to that on Earth, as does energy availability. However, despite adequate intake of energy and protein and in-flight exercise, lean body mass was catabolized, as indicated by negative nitrogen balance. Metabolic studies during simulated microgravity (bed rest) and true microgravity in flight have shown changes in blood glucose, fatty acids and insulin concentrations, suggesting that energy metabolism may be altered during space flight. Future research should focus on the interactions of lean body mass, diet and exercise in space, and their roles in energy metabolism during space flight. RP LANE, HW (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,BIOMED OPERAT & RES BRANCH,HOUSTON,TX 77058, USA. NR 31 TC 36 Z9 37 U1 1 U2 1 PU AMER INST NUTRITION PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0022-3166 J9 J NUTR JI J. Nutr. PD JAN PY 1992 VL 122 IS 1 BP 13 EP 18 PG 6 WC Nutrition & Dietetics SC Nutrition & Dietetics GA GZ446 UT WOS:A1992GZ44600001 PM 1729462 ER PT J AU DINAN, FJ SCHWARTZ, WT WOLFE, RA HOJNICKI, DS STCLAIR, T PRATT, JR AF DINAN, FJ SCHWARTZ, WT WOLFE, RA HOJNICKI, DS STCLAIR, T PRATT, JR TI SOLID-STATE C-13-NMR SPECTRAL EVIDENCE FOR CHARGE-TRANSFER COMPLEX-FORMATION IN AROMATIC DIIMIDES AND DIANHYDRIDES SO JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY LA English DT Article DE SOLID STATE C-13-NMR; C-13-NMR; CHARGE TRANSFER COMPLEX; DIIMIDES; DIANHYDRIDES; 4,4'-ISOPHTHALOYLDIPHTHALIC ANHYDRIDE; 4,4'-TEREPHTHALOYLDIPHTHALIC ANHYDRIDE ID NMR AB Solution and solid-state proton decoupled C-13-NMR spectra were determined on two diimides derived from 4,4'-oxydiphthalic anhydride. Comparison of the individual diimide spectra to that of a mixture of the two diimides indicates that ordering of these materials occurs in the solid state via charge transfer complex formation. A similar study was conducted using two isomeric dianhydrides, 4,4'-isophthaloyldiphthalic anhydride (IDPA) and 4,4'-terephthaloyldiphthalic anhydride (TDPA). The solution spectra of these compounds are similar and are those which would be expected for these compounds. However, their solid state spectra differ from each other. The solid-state spectrum of TDPA resembles its solution spectrum, whereas, that of IDPA differs greatly from its solution spectrum and indicates charge transfer complex formation occurs with this molecule. This difference is explained in terms of the stereochemistry of the two isomeric dianhydrides. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. OCCIDENTAL CHEM CORP,GRAND ISL,NY 14072. AMOCO PERFORMANCE PROD,ALPHARETTA,GA 30202. RP DINAN, FJ (reprint author), CANISIUS COLL,DEPT CHEM,BUFFALO,NY 14208, USA. NR 21 TC 29 Z9 29 U1 1 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-624X J9 J POLYM SCI POL CHEM JI J. Polym. Sci. Pol. Chem. PD JAN PY 1992 VL 30 IS 1 BP 111 EP 118 DI 10.1002/pola.1992.080300114 PG 8 WC Polymer Science SC Polymer Science GA GV809 UT WOS:A1992GV80900014 ER PT J AU GAUTREAUX, CR PRATT, JR STCLAIR, TL AF GAUTREAUX, CR PRATT, JR STCLAIR, TL TI A STUDY OF CRYSTALLINE TRANSITIONS IN A THERMOPLASTIC POLYIMIDE SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE POLYIMIDE, THERMOPLASTIC, CRYSTALLINE TRANSITIONS IN; CRYSTAL MORPHOLOGY OF THERMOPLASTIC POLYIMIDE DERIVED FROM IDPA AND 1,3,-BABB; DIFFERENTIAL SCANNING CALORIMETRY (DSC) OF SEMICRYSTALLINE THERMOPLASTIC POLYIMIDE AB A new polyimide derived from 4,4'-isophthaloyldiphthalic anhydride (IDPA) and 1,3-bis(4-aminophenoxy-4'-benzoyl) benzene (1,3-BABB) having semicrystalline behavior was prepared at NASA Langley Research Center in 1987. The crystalline transitions of this thermoplastic polyimide have been studied. The differential scanning calorimetry (DSC) pattern of partially imidized film exhibited two distinct crystalline melt endotherms. For this study each crystalline phase was isolated and enhanced by controlled thermal treatment. A film containing approximately 50% of both phases and an amorphous film were also prepared. Evaluations of these films were performed by DSC, wide-angle x-ray scattering (WAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Three distinct crystalline morphologies; ellipsoid, cubic, and needlelike embedded in an amorphous matrix were observed as a function of various cure conditions by SEM. C1 LOCKHEED ENGN & SCI CO,HAMPTON,VA 23665. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP GAUTREAUX, CR (reprint author), ANALYT SERV & MAT INC,HAMPTON,VA 23665, USA. NR 9 TC 14 Z9 14 U1 0 U2 5 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD JAN PY 1992 VL 30 IS 1 BP 71 EP 82 DI 10.1002/polb.1992.090300107 PG 12 WC Polymer Science SC Polymer Science GA GV818 UT WOS:A1992GV81800007 ER PT J AU BUCKMANN, PS SHRIMP, NR VITERI, F PROCTOR, M AF BUCKMANN, PS SHRIMP, NR VITERI, F PROCTOR, M TI DESIGN AND TEST OF AN OXYGEN TURBOPUMP FOR A DUAL EXPANDER CYCLE ROCKET ENGINE SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT 25TH JOINT PROPULSION CONF CY JUL 10-12, 1989 CL MONTEREY, CA SP AMER INST AERONAUT & ASTRONAUT, AMER SOC MECH ENGINEERS, SOC AUTOMOT ENGINEERS, AMER SOC ENGN EDUC AB A liquid oxygen (LOX) turbopump with an 860-degrees-R gaseous oxygen (GOX) turbine drive was designed for a 3750-lb thrust dual expander cycle rocket engine. This turbopump, which requires no interpropellant seals or system purges, features a 156-hp, single-stage, full admission, impulse turbine; an axial flow inducer; a two-stage centrifugal pump with unshrouded impellers; long-life, LOX-lubricated, self-aligning, hydrostatic bearings; and a subcritical rotor design. It is constructed of Monel, a nickel-copper alloy, which has low ignition potential in oxygen. The pump was designed to deliver 34.7 gpm of 4655 psia LOX at a shaft speed of 75,000 rpm. The dual expander cycle rocket engine and the performance it requires of the LOX turbopump will be discussed as well as the design of the pump, turbine, bearings, and the turbopump rotordynamics. The test program and preliminary test results will also be presented. C1 NASA,LEWIS RES CTR,ORBIT TRANSFER ROCKET ENGINE TECHNOL PROGRAM,CLEVELAND,OH 44135. RP BUCKMANN, PS (reprint author), AEROJET TECHSYST CO,ROTATING MACHINERY,SACRAMENTO,CA 95813, USA. NR 4 TC 0 Z9 0 U1 1 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1992 VL 8 IS 1 BP 80 EP 86 DI 10.2514/3.23445 PG 7 WC Engineering, Aerospace SC Engineering GA GZ467 UT WOS:A1992GZ46700012 ER PT J AU THOMAS, DA AF THOMAS, DA TI LONG-LIFE ASSESSMENT OF GRAPHITE EPOXY MATERIALS FOR SPACE STATION FREEDOM PRESSURE-VESSELS SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID CREEP-RUPTURE; STATISTICS AB Graphite/epoxy composite overwrapped pressure vessels are being considered for use on Space Station Freedom because of their light weight and high efficiency. These composite pressure vessels weigh roughly one-third of comparable all-metal aluminum pressure vessels, and could result in a 15,000-lb weight saving for the propulsion and fluid management and distribution systems. These vessels must resist failures under sustained pressure loads for crew safety considerations and adequate protection of the space structure during their 30-yr life. As 30-yr stress-rupture test data are not available, Weibull statistical analysis techniques have been applied and a model developed for predicting long-term stress-rupture behavior based on published short-term test data on composite strands and pressure vessels. Graphite/epoxy materials are calculated to have a 99.99% probability of surviving stress rupture for 30 yr under a sustained load of 50% ultimate failure strength. Stress-rupture life-times are predicted to increase as the size of the pressure vessels increases in support of the viscoelastic load-transfer mechanism proposed for stress rupture of fiber/epoxy composite materials. RP THOMAS, DA (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,DIV STRUCT & MECH,MAT BRANCH,MAIL CODE ES5,HOUSTON,TX 77058, USA. NR 15 TC 3 Z9 3 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1992 VL 8 IS 1 BP 87 EP 92 DI 10.2514/3.23446 PG 6 WC Engineering, Aerospace SC Engineering GA GZ467 UT WOS:A1992GZ46700013 ER PT J AU NALLASAMY, M GROENEWEG, JF AF NALLASAMY, M GROENEWEG, JF TI UNSTEADY EULER ANALYSIS OF THE FLOWFIELD OF A PROPFAN AT AN ANGLE OF ATTACK SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB The paper examines the effects of angle of attack of a propfan on the blade loading and details of the flowfield by solving the unsteady three-dimensional Euler equations. The configuration considered is the SR7L propeller at cruise condition and the inflow angles considered are 4.6, 1.6, and - 0.4 deg. The results indicate that the blade response is nearly sinusoidal at low inflow angles (1.6 and - 0.4 deg) and significant deviations from sinusoidal behavior occur at an inflow angle of 4.6 deg due to the presence of strong shocks on both suction and pressure surfaces of the blade. The detailed flow in the blade passages shows that a shock formed on the suction surface during the highly loaded portion of the revolution extends across the passage to the pressure surface. An increase in inflow angle results in an increase in blade loading on the down-going side and a decrease in loading on the up-going side. C1 SVERDRUP TECHNOL INC,BROOK PK,OH 44142. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 12 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1992 VL 8 IS 1 BP 136 EP 143 DI 10.2514/3.23453 PG 8 WC Engineering, Aerospace SC Engineering GA GZ467 UT WOS:A1992GZ46700020 ER PT J AU HOLDEMAN, JD SRINIVASAN, R REYNOLDS, RS WHITE, CD AF HOLDEMAN, JD SRINIVASAN, R REYNOLDS, RS WHITE, CD TI STUDIES OF THE EFFECTS OF CURVATURE ON DILUTION JET MIXING SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID CROSS-FLOW AB An analytical program was conducted using both three-dimensional numerical and empirical models to investigate the effects of transition liner curvature on the mixing of jets injected into a confined crossflow. The numerical code is of the TEACH type with hybrid numerics; it uses the power-law and SIMPLER algorithms, an orthogonal curvilinear coordinate system, and an algebraic Reynolds stress turbulence model. From the results of the numerical calculations, an existing empirical model for the temperature field downstream of single and multiple rows of jets injected into a straight rectangular duct was extended to model the effects of curvature. Temperature distributions, calculated with both the numerical and empirical models, are presented to show the effects of radius of curvature and inner and outer wall injection for single and opposed rows of cool dilution jets injected into a hot mainstream flow. C1 ALLIED SIGNAL AEROSP CO,GARRETT ENGINE DIV,COMBUST ENGN SCI,PHOENIX,AZ 85010. ALLIED SIGNAL AEROSP CO,GARRETT ENGINE DIV,ADV TECHNOL,PHOENIX,AZ 85010. RP HOLDEMAN, JD (reprint author), NASA,LEWIS RES CTR,DIV INTERNAL FLUID MECH,CLEVELAND,OH 44135, USA. NR 38 TC 3 Z9 3 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1992 VL 8 IS 1 BP 209 EP 218 DI 10.2514/3.23462 PG 10 WC Engineering, Aerospace SC Engineering GA GZ467 UT WOS:A1992GZ46700029 ER PT J AU BOYCE, L CHAMIS, CC AF BOYCE, L CHAMIS, CC TI PROBABILISTIC CONSTITUTIVE RELATIONSHIPS FOR CYCLIC MATERIAL STRENGTH MODELS SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB A methodology is developed that provides a probabilistic treatment for the lifetime of structural components of aerospace propulsion systems subjected to fatigue. Material strength degradation models include both a heuristic fatigue strength reduction model and a fatigue crack growth model. Probabilistic analysis is based on simulation, and both maximum entropy and maximum penalized likelihood methods are used for the generation of probability density functions. The resulting constitutive relationships are included in several computer programs. The programs determine the random time for a nickel-base superalloy engine component to reach a given fatigue strength or a given crack size. Results are presented in the form of probability density functions and cumulative distribution functions of the log of mechanical fatigue cycles. C1 NASA,LEWIS RES CTR,DIV STRUCT,CLEVELAND,OH 44135. RP BOYCE, L (reprint author), UNIV TEXAS,DIV ENGN,SAN ANTONIO,TX 78249, USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1992 VL 8 IS 1 BP 227 EP 232 DI 10.2514/3.23464 PG 6 WC Engineering, Aerospace SC Engineering GA GZ467 UT WOS:A1992GZ46700031 ER PT J AU MEYER, D WEBER, K SCOTT, W AF MEYER, D WEBER, K SCOTT, W TI ELECTRIC AUXILIARY POWER UNIT FOR SHUTTLE EVOLUTION SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT 25TH JOINT PROPULSION CONF CY JUL 10-12, 1989 CL MONTEREY, CA SP AMER INST AERONAUT & ASTRONAUT, AMER SOC MECH ENGINEERS, SOC AUTOMOT ENGINEERS, AMER SOC ENGN EDUC AB The Space Shuttle Orbiter currently uses three hydrazine-fueled auxiliary power units (APUs) to provide hydraulic power for the vehicle aerodynamic surface controls, main engine thrust vector control, landing gear, steering, and brakes. Electric APUs have been proposed as possible replacements to the hydrazine APUs. Along with the potential advantages, this paper describes an electric APU configuration and addresses the technical issues and risks associated with the subsystem components. In addition, characteristics of an electric APU compared with the existing APU and the direction of future study with respect to the electric APU are suggested. C1 NASA,LYNDON B JOHNSON SPACE CTR,APU SUBSYST PROGRAM,HOUSTON,TX 77058. SUNDSTRAND AEROSP,DEPT 741F6,ROCKFORD,IL 61125. RP MEYER, D (reprint author), SUNDSTRAND AEROSP,DEPT 710E6,4747 HARRISON AVE,ROCKFORD,IL 61125, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1992 VL 8 IS 1 BP 233 EP 239 DI 10.2514/3.23465 PG 7 WC Engineering, Aerospace SC Engineering GA GZ467 UT WOS:A1992GZ46700032 ER PT J AU ZUBE, DM MYERS, RM AF ZUBE, DM MYERS, RM TI TECHNIQUES FOR SPECTROSCOPIC MEASUREMENTS IN AN ARCJET NOZZLE SO JOURNAL OF PROPULSION AND POWER LA English DT Note C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 10 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 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 1992 VL 8 IS 1 BP 254 EP 256 DI 10.2514/3.23470 PG 3 WC Engineering, Aerospace SC Engineering GA GZ467 UT WOS:A1992GZ46700037 ER PT J AU LOCKMAN, WK LAWRENCE, SL CLEARY, JW AF LOCKMAN, WK LAWRENCE, SL CLEARY, JW TI FLOW OVER AN ALL-BODY HYPERSONIC AIRCRAFT - EXPERIMENT AND COMPUTATION SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB The objective of the present investigation is to establish a benchmark experimental data base for a generic hypersonic vehicle shape for validation and/or calibration of advanced computational fluid dynamics computer codes. This paper includes results from the comprehensive lest program conducted in the NASA Ames 3.5-ft Hypersonic Wind Tunnel for a generic all-body hypersonic aircraft model. Experimental and computational results on flow visualization, surface pressures, surface convective heat transfer, and pitot-pressure flowfield surveys are presented. Comparisons of the experimental results with computational results from an upwind parabolized Navier-Stokes code developed at NASA Ames demonstrate the capabilities of this code. C1 NASA,AMES RES CTR,APPL COMPUTAT FLUIDS BRANCH,MOFFETT FIELD,CA 94035. ELORET INST,SUNNYVALE,CA 94087. RP LOCKMAN, WK (reprint author), NASA,AMES RES CTR,AEROTHERMODYNAM BRANCH,MOFFETT FIELD,CA 94035, USA. NR 19 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 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 1992 VL 29 IS 1 BP 7 EP 15 DI 10.2514/3.26308 PG 9 WC Engineering, Aerospace SC Engineering GA HD174 UT WOS:A1992HD17400001 ER PT J AU THOMPSON, RA GNOFFO, PA AF THOMPSON, RA GNOFFO, PA TI APPLICATION OF THE LAURA CODE FOR SLENDER-VEHICLE AEROTHERMODYNAMICS SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB Application of a three-dimensional thin-layer Navier-Stokes code (LAURA) to compute the laminar and turbulent perfect gas aerothermodynamics of slender vehicles is demonstrated in this paper. Comparison of solutions with experimental data enabled an assessment of the code's aerodynamic heating prediction capabilities. The results show radial grid refinement to a wall cell Reynolds number of 2 to be accurate for predicting aerodynamic heating to a slender cone. Additional comparisons for an 80-deg slab-delta wing, a generic aero-space plane vehicle, and an all-body configuration show the method to be generally accurate using this radial cell spacing. Discrepancies between the predicted and measured heating in a region of crossflow separation on the generic aero-space plane geometry are noted, which indicates the need for further study. Although additional applications and comparisons are required to fully test the LAURA program, the results of this study demonstrate the current level of confidence and the engineering utility of this particular code for slender-vehicle applications. RP THOMPSON, RA (reprint author), NASA,LANGLEY RES CTR,DIV SPACE SYST,AEROTHERMODYNAM BRANCH,HAMPTON,VA 23665, USA. NR 23 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 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 1992 VL 29 IS 1 BP 16 EP 23 DI 10.2514/3.26309 PG 8 WC Engineering, Aerospace SC Engineering GA HD174 UT WOS:A1992HD17400002 ER PT J AU AHMADJIAN, M JENNINGS, DE MUMMA, MJ GREEN, BD DIX, BD RUSSELL, RW AF AHMADJIAN, M JENNINGS, DE MUMMA, MJ GREEN, BD DIX, BD RUSSELL, RW TI SKIRT SPACE-SHUTTLE GLOW EXPERIMENT SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID SATELLITE AB This paper describes a spectrometer/radiometer experiment to obtain infrared, visible, and ultraviolet measurements of Space Shuttle glow. The payload, Spacecraft Kinetic Infrared Test (SKIRT), is a cryogenic circular variable filter infrared spectrometer with a number of infrared, visible, and ultraviolet radiometers covering the spectral range of 0.2-5.4-mu-m and 9.9-10.3-mu-m. It will measure Shuttle glow as a function of mission elapsed time, Orbiter attitude, temperature, and Orbiter events such as thruster firings. The measured data should have sufficient spectral resolution and sensitivity to identify molecular species contributing to Shuttle glow emissions. SKIRT is manifested on STS-39. C1 NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. PHYS SCI INC,ANDOVER,MA 01810. SPACE SYST ENGN,LOGAN,UT 84321. AEROSPACE CORP,CTR SPACE & ENVIRONM TECHNOL,LOS ANGELES,CA 90009. RP AHMADJIAN, M (reprint author), USAF,SYST COMMAND,PHILLIPS LAB,GEOPHYS DIRECTORATE,DIV OPT ENVIRONM,BEDFORD,MA 01731, USA. RI Jennings, Donald/D-7978-2012; mumma, michael/I-2764-2013 NR 11 TC 4 Z9 4 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 1992 VL 29 IS 1 BP 102 EP 107 DI 10.2514/3.26320 PG 6 WC Engineering, Aerospace SC Engineering GA HD174 UT WOS:A1992HD17400013 ER PT J AU BUSH, LB LENTZ, CA ROBINSON, JC MACCONOCHIE, IO AF BUSH, LB LENTZ, CA ROBINSON, JC MACCONOCHIE, IO TI STRUCTURAL DESIGN CONSIDERATIONS FOR A PERSONNEL LAUNCH SYSTEM SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB A vehicle capable of performing the transfer of eight people to and from the Space Station Freedom is currently in the conceptual/preliminary design stages at the NASA Langley Research Center. Structural definition of this personnel launch system and the considerations leading to it are described. Issues such as cost, technology level, human factors, and maintainability are used as guidelines for the structural definition. A synergistic design technique involving aerodynamics, performance, mission, packaging, and weights and sizing analyses is utilized to evaluate the structural design. A closed-loop design is achieved when the mission requirements are met by each previously mentioned analysis for a particular vehicle weight. Although satisfactory, the structural concept presented herein is not to be treated as a final answer, but one promising solution. An examination of alternative designs and more detailed analyses can be undertaken in order to identify design inadequacies and more efficient approaches. C1 OLD DOMINION UNIV,RES FDN,NORFOLK,VA 23508. LOCKHEED ENGN & SCI CO,HAMPTON,VA 23665. RP BUSH, LB (reprint author), NASA,LANGLEY RES CTR,DIV SPACE SYST,HAMPTON,VA 23665, USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 1992 VL 29 IS 1 BP 138 EP 149 DI 10.2514/3.26325 PG 12 WC Engineering, Aerospace SC Engineering GA HD174 UT WOS:A1992HD17400018 ER PT J AU STIEGMAN, AE BRINZA, DE LAUE, EG ANDERSON, MS LIANG, RH AF STIEGMAN, AE BRINZA, DE LAUE, EG ANDERSON, MS LIANG, RH TI VACUUM ULTRAVIOLET-RADIATION - ATOMIC OXYGEN SYNERGISM IN FLUORINATED ETHYLENE PROPYLENE TEFLON EROSION SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Note C1 CALTECH,JET PROP LAB,INSTRUMENT RES GRP,PASADENA,CA 91109. CALTECH,JET PROP LAB,ANALYT CHEM GRP,PASADENA,CA 91109. RP STIEGMAN, AE (reprint author), CALTECH,JET PROP LAB,SPACE ENVIRONM EFFECTS GRP,MS 67-201,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 9 TC 11 Z9 13 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 1992 VL 29 IS 1 BP 150 EP 151 DI 10.2514/3.26326 PG 2 WC Engineering, Aerospace SC Engineering GA HD174 UT WOS:A1992HD17400019 ER PT J AU FULLER, CR SILCOX, RJ AF FULLER, CR SILCOX, RJ TI ACTIVE STRUCTURAL ACOUSTIC CONTROL SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Note ID VIBRATION C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP FULLER, CR (reprint author), VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061, USA. NR 13 TC 19 Z9 23 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JAN PY 1992 VL 91 IS 1 BP 519 EP 519 DI 10.1121/1.402743 PG 1 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA HE385 UT WOS:A1992HE38500054 ER PT J AU GRANT, WB KAGANN, RH MCCLENNY, WA AF GRANT, WB KAGANN, RH MCCLENNY, WA TI OPTICAL REMOTE MEASUREMENT OF TOXIC GASES SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Review AB Enactment of the Clean Air Act Amendments (CAAA) of 1990 has resulted in increased ambient air monitoring needs for industry, some of which may be met efficiently using open-path optical remote sensing techniques. These techniques include Fourier transform spectroscopy, differential optical absorption spectroscopy, laser long-path absorption, differential absorption lidar, and gas cell correlation spectroscopy. With this regulatory impetus, it is an opportune time to consider applying these technologies to the remote and/or path-averaged measurement and monitoring of toxic gases covered by the CAAA. This article reviews the optical remote sensing technology and literature for that application. C1 MDA SCI,NORCROSS,GA 30071. US EPA,ATMOSPHER RES & EXPOSURE ASSESSMENT LAB,RES TRIANGLE PK,NC 27711. RP GRANT, WB (reprint author), NASA,LANGLEY RES CTR,MS 401A,HAMPTON,VA 23665, USA. RI Grant, William/B-8311-2009 OI Grant, William/0000-0002-1439-3285 NR 0 TC 60 Z9 64 U1 0 U2 5 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA PO BOX 2861, PITTSBURGH, PA 15230 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD JAN PY 1992 VL 42 IS 1 BP 18 EP 30 PG 13 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA HC612 UT WOS:A1992HC61200007 PM 1575966 ER PT J AU MORSCHER, GN DICARLO, JA AF MORSCHER, GN DICARLO, JA TI A SIMPLE TEST FOR THERMOMECHANICAL EVALUATION OF CERAMIC FIBERS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE TESTING; FIBERS; CREEP; BENDING; STRESS RELAXATION ID CREEP AB A simple bend stress relaxation (BSR) test has been developed to measure the creep-related deformation properties of ceramic fibers and whiskers. The test was applied to a variety of commercial and developmental Si-based fibers to demonstrate test capabilities and to qualitatively evaluate the relative creep resistance of the fibers at 1200-degrees and 1400-degrees-C. The implications of these results and the advantages of the BSR test over typical tensile creep tests are discussed. RP MORSCHER, GN (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 13 TC 59 Z9 59 U1 0 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 1992 VL 75 IS 1 BP 136 EP 140 DI 10.1111/j.1151-2916.1992.tb05455.x PG 5 WC Materials Science, Ceramics SC Materials Science GA HF198 UT WOS:A1992HF19800024 ER PT J AU CALOMINO, AM BREWER, DN AF CALOMINO, AM BREWER, DN TI CONTROLLED CRACK-GROWTH SPECIMEN FOR BRITTLE SYSTEMS SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE CRACK GROWTH; FRACTURE; BRITTLE MATERIALS; TOUGHNESS; TESTING ID FRACTURE-TOUGHNESS AB A pure Mode I fracture specimen and test procedure has been developed which provides extended, stable, through-thickness crack growth in ceramics and other brittle, nonmetallic materials. Fixed displacement loading, applied at the crack mouth, promotes stable crack extension by reducing the stored elastic strain energy. Extremely fine control of applied displacements is achieved by utilizing the Poisson expansion of a compressively loaded cylindrical pin. Stable cracks have been successfully grown in soda-lime glass and monolithic Al2O3 for lengths in excess of 20 mm without uncontrollable catastrophic failure. RP CALOMINO, AM (reprint author), NASA,LEWIS RES CTR,USA,AVIAT RES & TECHNOL ACTIV,PROPULS DIRECTORATE,CLEVELAND,OH 44135, USA. NR 7 TC 7 Z9 7 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 1992 VL 75 IS 1 BP 206 EP 208 DI 10.1111/j.1151-2916.1992.tb05467.x PG 3 WC Materials Science, Ceramics SC Materials Science GA HF198 UT WOS:A1992HF19800036 ER PT J AU RODRIGUEZ, G JAIN, A KREUTZDELGADO, K AF RODRIGUEZ, G JAIN, A KREUTZDELGADO, K TI SPATIAL OPERATOR ALGEBRA FOR MULTIBODY SYSTEM DYNAMICS SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article AB This paper describes a new spatial operator algebra for the dynamics of general-topology rigid multibody systems. Spatial operators allow a concise and systematic formulation of the dynamical equations of motion of multibody systems and the development of efficient computational algorithms. Equations of motion are developed for progressively more complex systems: serial chains, topological trees, and closed-loop systems. New operator factorizations and expressions for the mass matrix and its inverse are derived and used to obtain efficient, spatially recursive computational algorithms. The algorithms can be easily reconfigured in response to changes in the constraints and the topology of constituent bodies. Thus, they are particularly suited for time-varying multibody systems. References are provided for extensions to flexible multibody systems. Spatially recursive algorithms, based on the sequential filtering and smoothing methods encountered in optimal estimation theory, provide the computational infrastructure to mechanize the spatial operators. C1 UNIV CALIF SAN DIEGO,DEPT AMES,LA JOLLA,CA 92093. RP RODRIGUEZ, G (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 17 TC 61 Z9 66 U1 0 U2 5 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD JAN-MAR PY 1992 VL 40 IS 1 BP 27 EP 50 PG 24 WC Engineering, Aerospace SC Engineering GA HP051 UT WOS:A1992HP05100003 ER PT J AU BOLTZ, FW AF BOLTZ, FW TI ANALYTIC SOLUTION FOR HORIZONTAL LAUNCH INTO ORBIT SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article AB An approximate analytic solution is presented for the motion, heating, and mass loss of lifting spacecraft launched horizontally for ascending flight through the atmosphere into Earth orbit. The solution is based on Chapman's Z-function transformation of the equations of motion with the assumption of an exponential atmosphere. The transformed equations have been modified to include the effects of thrusting with mass loss and with the thrust angle equal to the angle of attack. In the analytic solution presented it is assumed that flight through the atmosphere takes place in two phases. The first phase is that using air-breathing propulsion and variable lift-to-drag ratio during acceleration to hypersonic speed with the thrust-to-drag and drag-to-weight ratios considered fixed. It is found that the fuel mass fraction for this phase of flight is reduced by increasing the thrust-to-drag ratio and, thereby, steepening the ascent flight path. The second phase is that using rocket propulsion with maximum lift and thrust while leaving the lower atmosphere to achieve a nearly-optimum flight path for minimizing the aerodynamic heating and required thrust level during acceleration to orbital speed. Numerical results from the analytic solution are presented for two hypothetical vehicles similar to the British HOTOL with air-breathing propulsion to Mach 5 and the American NASP (X-30) with air-breathing propulsion to Mach 10. The estimated fuel/propellant mass fractions required at takeoff for these single-stage-to-orbit vehicles are found to be about 0.89 and 0.82, respectively. When the changeover to rocket propulsion is extended to orbital speed, the fuel/propellant mass fraction at takeoff is only improved to about 0.75 which virtually precludes single stage to orbit as a viable concept. C1 NATL AERONAUT & SPACE ADM,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 13 TC 1 Z9 1 U1 1 U2 1 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD JAN-MAR PY 1992 VL 40 IS 1 BP 51 EP 89 PG 39 WC Engineering, Aerospace SC Engineering GA HP051 UT WOS:A1992HP05100004 ER PT J AU MCNAMEE, JB KRONSCHNABL, GR WONG, SK EKELUND, JE AF MCNAMEE, JB KRONSCHNABL, GR WONG, SK EKELUND, JE TI A GRAVITY-FIELD TO SUPPORT MAGELLAN NAVIGATION AND SCIENCE AT VENUS SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article AB The Magellan spacecraft was inserted into orbit around Venus on August 10, 1990, and began the systematic mapping of the planet surface using a synthetic aperture radar (SAR) in imaging and altimetric modes on September 15, 1990. The primary Magellan science objective of obtaining high resolution SAR and altimetry data of the Venus surface topography requires the prediction and reconstruction of accurate spacecraft ephemerides. The orbit prediction and knowledge requirements for Magellan are the most stringent of any planetary orbiter to date. Pre-encounter covariance and simulation studies indicated that mismodeling of the Venus gravitational field would account for in excess of 90% of the Magellan orbit determination and prediction errors. Members of the Magellan Navigation Team processed Doppler tracking data from the Pioneer Venus Orbiter (PVO) spacecraft to produce a new Venus harmonic gravity field complete to degree and order 21 in order to improve Magellan orbit determination and prediction accuracies. Information arrays were produced from multiple revolution fits to PVO tracking data and combined to form the 21 x 21 Venus gravity field designated JPL Venus Gravity Model 1A (JPL-VGM1A). A second iteration version of this model which also incorporated additional data to fill in gaps in longitudinal coverage is designated JPL-VGM1B. The VGM1B harmonic field produced significant improvements in the Doppler residual statistics obtained from field validation fits to both PVO and Magellan tracking data in comparison with alternative representations of Venus gravity. In addition, both PVO and Magellan trajectory errors were reduced substantially through the use of the VGM1B field in place of previous solutions for the Venus gravitational potential. RP MCNAMEE, JB (reprint author), CALTECH,JET PROP LAB,MAGELLAN NAVIGAT TEAM,PASADENA,CA 91109, USA. NR 22 TC 9 Z9 9 U1 1 U2 2 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD JAN-MAR PY 1992 VL 40 IS 1 BP 107 EP 134 PG 28 WC Engineering, Aerospace SC Engineering GA HP051 UT WOS:A1992HP05100006 ER PT J AU SHARMA, SP HUO, WM PARK, C AF SHARMA, SP HUO, WM PARK, C TI RATE PARAMETERS FOR COUPLED VIBRATION-DISSOCIATION IN A GENERALIZED SSH APPROXIMATION SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article AB We report a theoretical study of vibrational excitations and dissociations of nitrogen undergoing a nonequilibrium relaxation process upon heating and cooling. The rate coefficients for collisional induced vibrational transitions and transitions from a bound vibrational state into a dissociative state have been calculated using an extension of the theory originally proposed by Schwartz, Slawsky, and Herzfeld (SSH). High-lying vibrational states and dissociative states were explicitly included, but rotational energy transfer was neglected. The transition probabilities calculated from the SSH theory were fed into the master equation, which was integrated numerically to determine the population distribution of the vibrational states, as well as bulk thermodynamic properties. Our results show that 1) the transition rates have a minimum near the middle of the bound vibrational levels, causing a bottleneck in the vibrational relaxation and dissociation rates, 2) high vibrational states are always in equilibrium with the dissociative state, 3) for the heating case, only the low vibrational states relax, according to Landau-Teller theory, 4) for the cooling case, vibrational relaxation cannot be described by a rate equation, and 5) the average vibrational energy removed in dissociation is about 30% of the dissociation energy. C1 NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. NR 31 TC 24 Z9 24 U1 2 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JAN-MAR PY 1992 VL 6 IS 1 BP 9 EP 21 DI 10.2514/3.312 PG 13 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA HX492 UT WOS:A1992HX49200002 ER PT J AU OLYNICK, DP MOSS, JN HASSAN, HA AF OLYNICK, DP MOSS, JN HASSAN, HA TI MONTE-CARLO SIMULATION OF VIBRATIONAL-RELAXATION IN NITROGEN SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article AB Monte Carlo simulation of nonequilibrium vibrational relaxation of (rotationless) N2 using transition probabilities from an extended SSH theory is presented. A heating case is examined. For the range of temperatures considered, 4000-8000 K, the vibrational levels were found to be reasonably close to an equilibrium distribution at an average vibrational temperature based on the vibrational energy of the gas. As a result, they do not show any statistically significant evidence of the bottleneck observed in earlier studies of N2. Based on this finding, it appears that, for the temperature range considered, dissociation commences after all vibrational levels equilibrate at the translational temperature. These results are a consequence of the fact that the transition probability, p(v, v + 1), which is a function of energy but not temperature, is an increasing function of the vibrational level v. Therefore, a behavior similar to that of a harmonic oscillator should be expected. C1 N CAROLINA STATE UNIV, MECH & AEROSP ENGN, RALEIGH, NC 27695 USA. NASA, LANGLEY RES CTR, DIV SPACE SYST, AEROTHERMODYNAM BRANCH, HAMPTON, VA 23665 USA. NR 17 TC 5 Z9 5 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JAN-MAR PY 1992 VL 6 IS 1 BP 22 EP 26 DI 10.2514/3.313 PG 5 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA HX492 UT WOS:A1992HX49200003 ER PT J AU POLESKY, SP DECHAUMPHAI, P GLASS, CE AF POLESKY, SP DECHAUMPHAI, P GLASS, CE TI 3-DIMENSIONAL THERMAL STRUCTURAL-ANALYSIS OF A SWEPT COWL LEADING-EDGE SUBJECTED TO SKEWED SHOCK-SHOCK INTERFERENCE HEATING SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article AB A three-dimensional flux-based thermal analysis method has been developed and its capability is demonstrated by predicting the transient nonlinear temperature response of a swept cowl leading edge subjected to intense three-dimensional aerodynamic heating. The predicted temperature response from the transient thermal analysis is used in a linear elastic structural analysis to determine thermal stresses. Predicted thermal stresses are compared with those obtained from a two-dimensional analysis which represents conditions along the chord where maximum heating occurs. Results indicate that a three-dimensional analysis could be required to predict accurately the leading edge thermal stress response. C1 NASA, LANGLEY RES CTR, AIRCRAFT STRUCT BRANCH, HAMPTON, VA 23665 USA. NASA, LANGLEY RES CTR, AEROTHERMAL LOADS BRANCH, HAMPTON, VA 23665 USA. LOCKHEED ENGN & SCI CO, HAMPTON, VA 23665 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JAN-MAR PY 1992 VL 6 IS 1 BP 48 EP 54 DI 10.2514/3.317 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA HX492 UT WOS:A1992HX49200007 ER PT J AU SIEGEL, R AF SIEGEL, R TI FINITE-DIFFERENCE SOLUTION FOR TRANSIENT COOLING OF A RADIATING-CONDUCTING SEMITRANSPARENT LAYER SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article AB Transient solutions were obtained for cooling a semitransparent material by radiation and conduction. The layer is in a vacuum environment so the only means for heat dissipation is by radiation from within the medium leaving through the boundaries. Heat conduction serves only to partially equalize temperatures across the layer. As the optical thickness is increased, steep temperature gradients exist near the boundaries when conduction is relatively small. A solution procedure is required that will provide accurate temperature distributions adjacent to the boundaries, or radiative heat losses will be in error. The approach utilized numerical Gaussian integration to obtain the local radiative source term, and a finite difference procedure with variable space and time increments to solve the transient energy equation. C1 NASA, LEWIS RES CTR, OFF CHIEF SCIENTIST, CLEVELAND, OH 44135 USA. NR 8 TC 17 Z9 19 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JAN-MAR PY 1992 VL 6 IS 1 BP 77 EP 83 DI 10.2514/3.321 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA HX492 UT WOS:A1992HX49200011 ER PT J AU VIJAYARAGHAVAN, D BREWE, DE AF VIJAYARAGHAVAN, D BREWE, DE TI FREQUENCY-EFFECTS ON THE STABILITY OF A JOURNAL BEARING FOR PERIODIC LOADING SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID CAVITATION ALGORITHM AB In this paper, stability of a journal bearing is numerically predicted when an unidirectional periodic external load is applied. The analysis is performed using a cavitation algorithm, which mimics the JFO theory by accounting for the mass balance through the complete bearing. Hence, the history of the film is taken into consideration. The loading pattern is taken to be sinusoidal and the frequency of the load cycle is varied. The results are compared with the predictions using Reynolds boundary conditions for both film rupture and reformation. With such comparisons, the need for accurately predicting the cavitation regions for complex loading patterns is clearly demonstrated. For a particular frequency of loading, the effects of mass, amplitude of load vibration and frequency of journal speed are also investigated. The journal trajectories, transient variations in fluid film forces, net surface velocity and minimum film thickness and pressure profiles are also presented. RP VIJAYARAGHAVAN, D (reprint author), NASA,LEWIS RES CTR,USA AVIAT RES & TECHNOL ACTIV,CLEVELAND,OH 44135, USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4787 J9 J TRIBOL-T ASME JI J. Tribol.-Trans. ASME PD JAN PY 1992 VL 114 IS 1 BP 107 EP 115 DI 10.1115/1.2920848 PG 9 WC Engineering, Mechanical SC Engineering GA HA908 UT WOS:A1992HA90800016 ER PT J AU ROWE, GL BRANTLEY, SL FERNANDEZ, M FERNANDEZ, JF BORGIA, A BARQUERO, J AF ROWE, GL BRANTLEY, SL FERNANDEZ, M FERNANDEZ, JF BORGIA, A BARQUERO, J TI FLUID-VOLCANO INTERACTION IN AN ACTIVE STRATOVOLCANO - THE CRATER LAKE SYSTEM OF POAS VOLCANO, COSTA-RICA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID HYDROTHERMAL SYSTEMS; WATER BODIES; ERUPTION; GEOCHEMISTRY; EVAPORATION; TREMOR AB Seismic and geochemical data collected at Poas volcano, Costa Rica, since 1978 suggest that temperature and chemical variations recorded in subaerial fumaroles and the crater lake are related to episodic release of heat and volatiles associated with hydrofracturing of the upper margin of the shallow magma body. Power outputs associated with these events approach 600 MW and are superimposed on a baseline energy flux of approximately 200 MW. The baseline heat flux suggests a magma solidification rate of 0.012 km3/yr and background volatile release rates of 1000 t/d H2O, 66 t/d, S, 13 t/d Cl, and 0.5 t/d F. These fluxes are comparable to fluxes of F, Cl and S exiting the magmatic/hydrothermal system through acidic flank springs and are about a factor of five less than estimated volatile fluxes through summit fumaroles during the high-temperature event of 1981-1983. Mass balance considerations suggest that heat released at the lake surface is primarily supplied by the ascent of heated brines supplemented by condensation of fumarolic steam. Calculated average seepage rates out of the lake (almost-equal-to 450 kg/s) indicate rapid convection of acidic lake brine through underlying lake sediments and pyroclastic deposits. Circulation of the extremely corrosive lake brine through the volcanoclastic material beneath the lake may enhance subsurface permeabilities. Fluxes of rock-forming elements observed in the Rio Agrio basin on the northwest flank of Poas suggest that dissolution and removal of volcano-clastic material occurs at a rate of approximately 1650 m3/yr. However, estimated sulfur fluxes from the cooling magma body suggest that porosity created by this dissolution could quickly be filled by the deposition of native sulfur. Finally, analysis of heat and water budgets for the crater lake over the period 1978-1989 indicates that the recent decline and disapperance of the lake was caused by variations in summit rainfall combined with an increase in subsurface heat flow to the lake in 1987-1988. The increase in heat flow is related to continued degassing of high-temperature volatiles following a hydrofracturing/magma ascent episode that occurred in 1986. C1 PENN STATE UNIV,DEPT GEOSCI,UNIV PK,PA 16802. SECC LAB QUIM,DEPT ESTUDIOS BASICOS,INST COSTARRICENSE ELECT,SAN JOSE,COSTA RICA. UNIV NACL HEREDIA,OBSERV VULCANOL & SISMOL COSTA RICA,HEREDIA,COSTA RICA. CALTECH,JET PROP LAB,MS 183501,PASADENA,CA 91109. UNIV COSTA RICA,CTR INVEST GEOFIS,RED SISMOL NACL,ICE,SAN JOSE,COSTA RICA. NR 94 TC 98 Z9 99 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JAN PY 1992 VL 49 IS 1-2 BP 23 EP 51 DI 10.1016/0377-0273(92)90003-V PG 29 WC Geosciences, Multidisciplinary SC Geology GA HF702 UT WOS:A1992HF70200002 ER PT J AU ELGAR, S GUZA, RT FREILICH, MH BRIGGS, MJ AF ELGAR, S GUZA, RT FREILICH, MH BRIGGS, MJ TI LABORATORY SIMULATIONS OF DIRECTIONALLY SPREAD SHOALING WAVES SO JOURNAL OF WATERWAY PORT COASTAL AND OCEAN ENGINEERING-ASCE LA English DT Article ID SURFACE GRAVITY-WAVES; NONLINEAR REFRACTION DIFFRACTION; SHALLOW-WATER; MODEL; BISPECTRA; BEACH AB Field observations of a shoaling, nonbreaking, directionally spread wave field are simulated in a laboratory basin to determine whether laboratory artifacts cause significant distortions of the shoaling process. The laboratory wave field is measured with scaled arrays of surface-elevation sensors similar to the arrays used for the field observations. However, differences in the laboratory and field beach slopes (0.033 and 0.025, respectively) do not allow precise replication of the field conditions in the laboratory. Therefore, a nonlinear wave propagation model with no adjustable parameters (previously successfully compared to a wide range of field data) is used to show that differences between the laboratory and field data sets are caused primarily by the different beach slopes. The observations demonstrate, in agreement with the model, that it is possible to compensate partially for differences in beach slope by altering the initial conditions. With such compensation, the evolution of surface-elevation power spectra, bispectra, and skewness and asymmetry are remarkably similar in the laboratory and field. Frequency-directional spectra measured just outside the surf zone also show similar nonlinear effects in both field and laboratory data. Based on this case study, the laboratory directional wave basin appears to be useful for investigating the linear and nonlinear evolution of random, two-dimensional waves on beaches. C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,CTR COASTAL STUDIES,LA JOLLA,CA 92093. CALTECH,JET PROP LAB,PASADENA,CA 91109. WATERWAYS EXPT STN,COASTAL ENGN RES CTR,VICKSBURG,MS 39180. RP ELGAR, S (reprint author), WASHINGTON STATE UNIV,ELECT & COMP ENGN,PULLMAN,WA 99164, USA. NR 19 TC 5 Z9 5 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-950X J9 J WATERW PORT C-ASCE JI J. Waterw. Port Coast. Ocean Eng.-ASCE PD JAN-FEB PY 1992 VL 118 IS 1 BP 87 EP 103 DI 10.1061/(ASCE)0733-950X(1992)118:1(87) PG 17 WC Engineering, Civil; Engineering, Ocean; Water Resources SC Engineering; Water Resources GA GW546 UT WOS:A1992GW54600007 ER PT J AU RAINES, G AF RAINES, G TI REAL-TIME ADA IN THE INTERNATIONAL SPACE STATION FREEDOM SO LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article AB This paper describes the Space Station Freedom, its Data Management System architecture, the on-board systems using this architecture, the design of the real time distributed Ada software, and methods of integration of the real time components. Problems encountered that are unique to the Ada programming language and their solutions will be addressed. RP RAINES, G (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0302-9743 J9 LECT NOTES COMPUT SC JI Lect. Notes Comput. Sci. PY 1992 VL 603 BP 9 EP 19 PG 11 WC Computer Science, Theory & Methods SC Computer Science GA LF684 UT WOS:A1992LF68400003 ER PT J AU LESH, JR AF LESH, JR TI THE NASA PROGRAM FOR OPTICAL DEEP-SPACE COMMUNICATIONS AT JPL SO LECTURE NOTES IN CONTROL AND INFORMATION SCIENCES LA English DT Article ID PHOTON AB As deep-space missions to the planets and other heavenly bodies acquire larger amounts of more sophisticated data, the demand for greater data return link communications capacity continues to increase. Past and current missions have stretched the capabilities of radio frequency systems close to their fundamental limits. For these reasons, NASA has been supporting the development of technologies and systems designs that will allow future missions to use optical beams for communications. such systems will permit dramatic increases in return link capacity with substantially smaller and less massive communications subsystems on board the spacecraft. The history and past accomplishments of the JPL deep-space optical communications program will be described, along with the plans for the future development, demonstration, and eventual deployment of this important technology. RP LESH, JR (reprint author), JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 20 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-8643 J9 LECT NOTES CONTR INF JI Lect. Notes Control Inf. Sci. PY 1992 VL 182 BP 159 EP 179 PG 21 WC Automation & Control Systems; Computer Science, Information Systems SC Automation & Control Systems; Computer Science GA LF998 UT WOS:A1992LF99800010 ER PT J AU ARDEMA, MD BOWLES, JV WHITTAKER, T AF ARDEMA, MD BOWLES, JV WHITTAKER, T TI OPTIMAL TRAJECTORIES FOR HYPERSONIC LAUNCH VEHICLES SO LECTURE NOTES IN CONTROL AND INFORMATION SCIENCES LA English DT Article; Proceedings Paper CT 4TH WORKSHOP ON CONTROL MECHANICS CY JAN 21-23, 1991 CL UNIV SO CALIF LOS ANGELES, LOS ANGELES, CA HO UNIV SO CALIF LOS ANGELES AB In this paper, we derive a near-optimal guidance law for the ascent trajectory from Earth surface to Earth orbit of a hypersonic, dual-mode propulsion, lifting vehicle. Of interest are both the optimal flight path and the optimal operation of the propulsion system. The guidance law is developed from the energy-state approximation of the equations of motion. The performance objective is a weighted sum of fuel mass and volume, with the weighting factor selected to give minimum gross take-off weight for a specific payload mass and volume. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NR 13 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-8643 J9 LECT NOTES CONTR INF JI Lect. Notes Control Inf. Sci. PY 1992 VL 170 BP 18 EP 28 PG 11 WC Automation & Control Systems; Computer Science, Information Systems SC Automation & Control Systems; Computer Science GA LF408 UT WOS:A1992LF40800002 ER PT J AU GAWRONSKI, W AF GAWRONSKI, W TI PREDICTIVE CONTROLLER AND ESTIMATOR FOR NASA DEEP SPACE NETWORK ANTENNAS SO LECTURE NOTES IN CONTROL AND INFORMATION SCIENCES LA English DT Article; Proceedings Paper CT 4TH WORKSHOP ON CONTROL MECHANICS CY JAN 21-23, 1991 CL UNIV SO CALIF LOS ANGELES, LOS ANGELES, CA HO UNIV SO CALIF LOS ANGELES C1 JET PROP LAB,PASADENA,CA 91109. NR 22 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-8643 J9 LECT NOTES CONTR INF JI Lect. Notes Control Inf. Sci. PY 1992 VL 170 BP 72 EP 105 PG 34 WC Automation & Control Systems; Computer Science, Information Systems SC Automation & Control Systems; Computer Science GA LF408 UT WOS:A1992LF40800006 ER PT J AU GOLUB, MA AF GOLUB, MA TI REACTIONS OF ATOMIC OXYGEN [O(P-3)] WITH POLYMER-FILMS SO MAKROMOLEKULARE CHEMIE-MACROMOLECULAR SYMPOSIA LA English DT Article; Proceedings Paper CT INTERNATIONAL SYMP ON POLYMER MATERIALS - PREPARATION, CHARACTERIZATION AND PROPERTIES ( POLYMER 91 ) CY FEB 10-15, 1991 CL MELBOURNE, AUSTRALIA SP INT UNION PURE & APPL CHEM, MACROMOLEC DIV, AUSTR ACAD SCI, AUSTR ACAD TECHNOL SCI & ENGN, ROYAL AUSTR CHEM INST, POLYM DIV ID LOW EARTH ORBIT; PLASMA; OXIDATION; COATINGS; ESCA; TETRAFLUOROETHYLENE; DOWNSTREAM; AFTERGLOW; KAPTON; O(3P) AB The reactions of polymer films with oxygen atoms are reviewed. Emphasis is on work from this laboratory on polybutadienes having different amounts of 1,4 or 1,2 double bonds and their polyalkenamer homologues, on a polyimide (Kapton), and on a series of polyolefins with increasing fluorine content ranging from polyethylene (PE) to polytetrafluoroethylene (PTFE). Interest in this topic stems from a need to understand the mechanism(s) of surface erosion, or etching, that occurs in organic polymers when exposed to the low Earth orbital (LEO) environment, where ground-state atomic oxygen [O(3P)] is the most abundant constituent. The major findings for O atom reactions with the polyalkenamers were: (1) etch rates increase with decrease in -CH = CH-unsaturation, starting with 1,4-polybutadiene and reaching the maximum rate with PE or ethylene-propylene rubber; (2) in polybutadienes having both 1,4 and 1,2 double bonds, the rate of O(3P)-induced etching is lower the higher the 1,2 content; and (3) the reactions are confined to the polymer surface. Relative etch rates for various commercial polymer films (e.g., Kapton, Teflon, PE) exposed to O(3P) downstream from a low-pressure, radio-frequency O2 plasma were compared with corresponding literature data for films exposed to O(3P) either during a Space Shuttle flight or in the plasma glow (where many species besides O(3P) are present). The use of O2 discharge reactors -- whether exposures are conducted "out of the glow" or "in the glow" -- cannot serve as a routine, ground-based simulation of exposures of a polymer to the LEO environment. ESCA analysis of the surfaces of Kapton and other polymers, before and after reaction with O(3P), showed that there is a steady-state competition between surface recession and oxidation. In a series of fluorine-containing polyolefins exposed to O(3P), the maximum oxygen uptake increased regularly with decrease in fluorine content, ranging from a minimum in PTFE to a maximum in PE. RP GOLUB, MA (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 42 TC 11 Z9 11 U1 1 U2 6 PU HUTHIG & WEPF VERLAG PI BASEL PA AUF DEM WOLF 4, CH-4052 BASEL, SWITZERLAND SN 0258-0322 J9 MAKROMOL CHEM-M SYMP PD JAN PY 1992 VL 53 BP 379 EP 391 DI 10.1002/masy.19920530134 PG 13 WC Polymer Science SC Polymer Science GA HF397 UT WOS:A1992HF39700033 ER PT B AU SIGLER, MF FUJIOKA, JT AF SIGLER, MF FUJIOKA, JT BE Kruse, G Eggers, DM Marasco, RJ Pautzke, C Quinn, TJ TI A COMPARISON OF POLICIES FOR HARVESTING SABLEFISH, ANOPLOPOMA-FIMBRIA, IN THE GULF OF ALASKA SO MANAGEMENT STRATEGIES FOR EXPLOITED FISH POPULATIONS SE LOWELL WAKEFIELD FISHERIES SYMPOSIA SERIES LA English DT Proceedings Paper CT International Symposium on Management Strategies for Exploited Fish Populations CY OCT 21-24, 1992 CL ANCHORAGE, AK SP ALASKA DEPT FISH & GAME, NATL MARINE FISHERIES SERV, N PACIFIC FISHERY MANAGEMENT COUNCIL, UNIV ALASKA SEA GRANT COLL PROGRAM C1 NATL MARINE FISHERIES SERV,AUKE BAY LAB,JUNEAU,AK. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ALASKA SEA GRANT COLL PROGRAM PI FAIRBANKS PA UNIV ALASKA FAIRBANKS, 138 IRVING 11, FAIRBANKS, AK 99775-5040 BN 1-56612-021-7 J9 LOW WAKE FI PY 1992 VL 10 BP 7 EP 19 PG 13 WC Fisheries SC Fisheries GA BB18D UT WOS:A1992BB18D00002 ER PT B AU PELLA, JJ AF PELLA, JJ BE Kruse, G Eggers, DM Marasco, RJ Pautzke, C Quinn, TJ TI UTILITY OF STRUCTURAL TIME-SERIES MODELS AND THE KALMAN FILTER FOR PREDICTING CONSEQUENCES OF FISHERIES ACTIONS SO MANAGEMENT STRATEGIES FOR EXPLOITED FISH POPULATIONS SE LOWELL WAKEFIELD FISHERIES SYMPOSIA SERIES LA English DT Proceedings Paper CT International Symposium on Management Strategies for Exploited Fish Populations CY OCT 21-24, 1992 CL ANCHORAGE, AK SP ALASKA DEPT FISH & GAME, NATL MARINE FISHERIES SERV, N PACIFIC FISHERY MANAGEMENT COUNCIL, UNIV ALASKA SEA GRANT COLL PROGRAM C1 NATL MARINE FISHERIES SERV,AUKE BAY LAB,JUNEAU,AK. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ALASKA SEA GRANT COLL PROGRAM PI FAIRBANKS PA UNIV ALASKA FAIRBANKS, 138 IRVING 11, FAIRBANKS, AK 99775-5040 BN 1-56612-021-7 J9 LOW WAKE FI PY 1992 VL 10 BP 571 EP 593 PG 23 WC Fisheries SC Fisheries GA BB18D UT WOS:A1992BB18D00026 ER PT B AU KRISHEN, K AF KRISHEN, K GP IEEE TI ROLE OF STRATEGIC PLANNING IN ENGINEERING MANAGEMENT SO MANAGING PROJECTS IN A BORDERLESS WORLD: INTERNATIONAL ENGINEERING MANAGEMENT CONFERENCE, PRE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT International Engineering Management Conference - Managing Projects in a Borderless World CY DEC 17-18, 1993 CL DELHI, INDIA SP IEEE, REG 10, IEEE, INDIA COUNCIL, IEEE, DELHI SECT, ABB, ABL, ALLEN BRADLEY, BHEL, BPL, BIRLA KENT TAYLOR, CEA, CEGELEC INDIA, CADEN CORP, CMC, CHLORO CONTROL, OECF, DULMISON, THAILAND, ESPL, GEC ALSTHOM, MARUBENI, MITSUBISHI, NTPC, SIEMENS, MATHER & PLATT, NRDC, POWERGRID, TCS, VIJAY FIRE, WORTHINGTON, VYSYA BANK C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-1763-7 PY 1992 BP 1 EP 6 PG 6 WC Engineering, Industrial SC Engineering GA BB79K UT WOS:A1992BB79K00001 ER PT J AU WHITTENBERGER, JD RAY, R LEE, DS AF WHITTENBERGER, JD RAY, R LEE, DS TI 1000 TO 1100-K DEFORMATION-BEHAVIOR OF 3 TIAL-BASED PARTICULATE COMPOSITES SO MATERIALS LETTERS LA English DT Article ID FLOW AB The 1000 to 1100 K strength properties have been determined as a function of strain rate for three particulate composites based on 1.45 wt.% B, 3.0 wt.% B and 10 wt.% HfB2 additions to Ti-48Al-2Mn-2Nb. Based on these measurements none of the composites offers an improvement in elevated temperature strength over existing TiAl-based materials. C1 MARKO MAT INC,N BILLERICA,MA 01862. MAT LAB,WRIGHT PATTERSON AFB,OH 45433. RP WHITTENBERGER, JD (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 13 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD JAN PY 1992 VL 12 IS 6 BP 453 EP 458 DI 10.1016/0167-577X(92)90213-4 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA HF326 UT WOS:A1992HF32600014 ER PT S AU CHEN, AB SHER, A YOST, WT AF CHEN, AB SHER, A YOST, WT BE Faber, KT Malloy, KJ TI ELASTIC-CONSTANTS AND RELATED PROPERTIES OF SEMICONDUCTOR COMPOUNDS AND THEIR ALLOYS SO MECHANICAL PROPERTIES OF SEMICONDUCTORS SE Semiconductors and Semimetals LA English DT Review ID ABSORPTION FINE-STRUCTURE; TRANSITION-METAL ALLOYS; RANDOM SOLID-SOLUTIONS; TIGHT-BINDING THEORY; VAPOR-PHASE EPITAXY; LONG-RANGE ORDER; 1ST-PRINCIPLES CALCULATION; ELECTRONIC-STRUCTURE; PSEUDOBINARY ALLOYS; ATOMIC-STRUCTURE C1 SRI INT, PHYS ELECTR LAB, MENLO PK, CA 94025 USA. NASA, LANGLEY RES CTR, HAMPTON, VA 23665 USA. RP AUBURN UNIV, DEPT PHYS, AUBURN, AL 36849 USA. NR 175 TC 11 Z9 11 U1 1 U2 3 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0080-8784 BN 0-12-752137-2 J9 SEMICONDUCT SEMIMET JI Semicond. Sdemimet. PY 1992 VL 37 BP 1 EP 77 PG 77 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA BZ72W UT WOS:A1992BZ72W00001 ER PT J AU SCHIANO, DJ TVERSKY, B AF SCHIANO, DJ TVERSKY, B TI STRUCTURE AND STRATEGY IN ENCODING SIMPLIFIED GRAPHS SO MEMORY & COGNITION LA English DT Article ID COGNITIVE REFERENCE POINTS; VISUAL TILT ILLUSIONS; ORIENTATION ILLUSIONS; POGGENDORFF ILLUSION; MEMORY; RECALL; MAPS; DISTORTIONS; PERCEPTION; MAGNITUDE AB Tversky and Schiano (1989) found a systematic bias toward the 45-degrees line in memory for the slopes of identical lines when embedded in graphs, but not in maps, suggesting the use of a cognitive reference frame specifically for encoding meaningful graphs. The present experiments explore this issue further using the linear configurations alone as stimuli. Experiments 1 and 2 demonstrate that perception and immediate memory for the slope of a test line within orthogonal "axes" are predictable from purely structural considerations. In Experiments 3 and 4, subjects were instructed to use a diagonal-reference strategy in viewing the stimuli, which were described as "graphs" only in Experiment 3. Results for both studies showed the diagonal bias previously found only for graphs. This pattern provides converging evidence for the diagonal as a cognitive reference frame in encoding linear graphs, and demonstrates that even in highly simplified displays, strategic factors can produce encoding biases not predictable solely from stimulus structure alone. RP SCHIANO, DJ (reprint author), NASA,AMES RES CTR,NRC,MS-262-3,MOFFETT FIELD,CA 94035, USA. NR 59 TC 41 Z9 42 U1 2 U2 3 PU PSYCHONOMIC SOC INC PI AUSTIN PA 1710 FORTVIEW RD, AUSTIN, TX 78704 SN 0090-502X J9 MEM COGNITION JI Mem. Cogn. PD JAN PY 1992 VL 20 IS 1 BP 12 EP 20 DI 10.3758/BF03208249 PG 9 WC Psychology, Experimental SC Psychology GA HH594 UT WOS:A1992HH59400002 PM 1549061 ER PT J AU PROCTOR, FH BOWLES, RL AF PROCTOR, FH BOWLES, RL TI 3-DIMENSIONAL SIMULATION OF THE DENVER 11 JULY 1988 MICROBURST-PRODUCING STORM SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID NUMERICAL SIMULATIONS; DOPPLER RADAR AB Near Denver on July 11 1988, a moderate-reflectivity thunder-storm produced a microburst of unusual intensity during the test operation of the Terminal Doppler Weather Radar (TDWR) system. This microburst-producing storm, unlike those previously investigated, contained a complex updraft structure and an intense microburst downstream from the main precipitation shaft. Of special significance is that several successive airliners inadvertently encountered the microburst during final approach to Stapleton Airport. This paper focuses on the numerical investigation of this storm - via simulation with the Terminal Area Simulation System (TASS). Evolution and structure of the storm, including hazard indices based on F-factor, are presented and compared with "observed" data, including that measured by Doppler radar and aircraft flight data recorders. Model results show that multiple low- to moderate-reflectivity microbursts formed downshear of the main precipitation shaft. The most intense of the modeled microbursts contained a velocity differential exceeding 40 m/s, strong downdrafts, and hazardous windshear with F-factors approaching 0.2. Outflow from this microburst was roughly symmetric at ground level during peak intensity, but became more asymmetric with time and altitude above the ground. The intense microburst, not unlike the real microburst that was encountered by the aircraft, originated from light precipitation that was swept downwind of the primary source. In contrast to the intense microburst, downdrafts and outflows associated with the simulated storm's main precipitation shaft were less vigorous by comparison, even though accompanied by higher magnitudes of radar reflectivity. Additional simulations with the axisymmetric version of TASS configured from the 3-D simulation, suggest that the intense microburst was driven by cooling primarily from sublimating snow. C1 NASA,LANGLEY RES CTR,WIND SHEAR PROGRAM OFF,HAMPTON,VA 23681. RP PROCTOR, FH (reprint author), NASA,LANGLEY RES CTR,DIV FLIGHT MANAGEMENT,HAMPTON,VA 23681, USA. NR 19 TC 10 Z9 12 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 1992 VL 49 IS 1-4 BP 107 EP 124 DI 10.1007/BF01025403 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA KB664 UT WOS:A1992KB66400007 ER PT J AU KAPLAN, ML KARYAMPUDI, VM AF KAPLAN, ML KARYAMPUDI, VM TI MESO-BETA SCALE NUMERICAL SIMULATIONS OF TERRAIN DRAG-INDUCED ALONG-STREAM CIRCULATIONS .1. MIDTROPOSPHERIC FRONTOGENESIS SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID MESOSCALE CONVECTIVE SYSTEM; DIAGNOSIS; EVOLUTION; DYNAMICS AB The problem of along-stream ageostrophic frontogenesis is studied by employing a numerical model at meso-alpha and meso-beta scales in simulations of the downstream circulations over the Front Range of the Rocky Mountains. Three-dimensional real data simulations at these two scales of motion are used to diagnose the transition from semi-geostrophic cross-stream frontogenesis accompanying a propagating baroclinic upper-level jet streak to midtropospheric along-stream ageostrophic frontogenesis. This along-stream ageostrophic frontogenesis results from the perturbation of the jet streak by the Rocky Mountain range. The case study represents an example of internal wave dynamics which are forced by the drag of the Rocky Mountains on a strong jet streak in the presence of a low-level inversion. The simulation results indicate that, unlike semi-geostrophic frontogenesis, a front (which is alligned perpendicular to the axis of the jet stream) may form when significant adiabatic heating occurs within a stratified shear flow over horizontal length scales shorter than the Rossby radius of deformation. The mechanism responsible for the frontogenesis is the growth of the divergent along-stream wind velocity component which becomes coupled to the front's along-stream pressure gradient force. This nonlinear interaction produces hydrostatic mesoscale frontogenesis as follows: 1) vertical wind shear in the along-stream plane strengthens resulting in the increasingly nonuniform vertical variation of horizontal temperature advection as the ageostrophic wind component grows in magnitude downstream of the meso-scale terrain-induced adiabatic heating, 2) increasing along-stream differential vertical motions (i.e., along-stream thermally indirect circulation with warm air sinking to the west and cold air rising to the east) tilt the vertical gradient of isentropes into the horizontal as the vertical temperature gradient increases due to the previous process in proximity to horizontal gradients in the along-stream component of the ageostrophic wind, 3) as tilting motions act to increase the along-stream horizontal temperature gradient, the along-stream confluence acts to nonuniformly increase the along-stream frontal temperature gradient which increases the along-stream pressure gradient force resulting in further accelerations, ageostrophy, and frontal steepening as part of a scale contraction process. The evolution of the aforementioned processes results in the three-dimensional hydrostatic frontogenesis accompanying the overturning of isentropic surfaces. These adjustments act to turn air parcels to the right of the southwesterly geostrophic wind vector at successively lower atmospheric levels as the scale contraction continues. This simulated along-stream front is verified from diagnostic analysis of the profiler-derived temperature and wind fields. C1 NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. RP KAPLAN, ML (reprint author), N CAROLINA STATE UNIV,DEPT MARINE EARTH & ATMOSPHER SCI,RALEIGH,NC 27695, USA. NR 24 TC 16 Z9 16 U1 0 U2 2 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 1992 VL 49 IS 1-4 BP 133 EP 156 DI 10.1007/BF01025405 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA KB664 UT WOS:A1992KB66400009 ER PT J AU KAPLAN, ML KARYAMPUDI, VM AF KAPLAN, ML KARYAMPUDI, VM TI MESO-BETA SCALE NUMERICAL SIMULATIONS OF TERRAIN DRAG-INDUCED ALONG-STREAM CIRCULATIONS .2. CONCENTRATION OF POTENTIAL VORTICITY WITHIN DRYLINE BULGES SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID SYSTEMS AB Hydrostatic and nonhydrostatic simulation models are employed to study the intensification of a terrain drag-induced dryline. The study develops a multi-stage theory for the evolution of the dryline including the concentration of potential vorticity accompanying meso-gamma scale dryline "bulges". The numerical simulations indicate three fundamental stages of dryline intensification all of which are either directly or indirectly a result of the terrain-drag on the mid/upper-tropospheric jet stream by the Front Range of the Colorado Rocky Mountains. The first stage involves the downward momentum flux accompanying a large amplitude hydrostatic mountain wave which induces a downslope windstorm along the lee slopes. The surge of momentum (i.e., the dry, warm air associated with the downslope windstorm) propagates down the leeslope and modifies an existing weak dryline boundary. As the downslope windstorm initiates an undular bore along the lee slopes, the high momentum gradient which propagates downstream accompanying the bore, as well as the strong lower tropospheric sinking motions ahead of the bore, contract the scale of the surface moisture boundary between the dry air from above the leeslope and the moist air over the High Plains. This process further strengthens the dryline. The second stage involves the coupling of the terrain drag-induced along-stream ageostrophic front within the midtroposphere to the boundary layer through a thermally-indirect circulation. As the along-stream ageostrophic circulation intensifies within the middle troposphere down-stream from the mountain wave, sinking air parcels originating above 40 kPa descend to below 60 kPa over the High Plains where surface pressures are only approximately 85 kPa. These descending air parcels within the upstream branch of the along-stream ageostrophic thermally-indirect circulation contain high values of momentum and very low dewpoint values. As the planetary boundary layer (PBL) deepens due to surface warming during the morning hours, momentum and dry air from the midtropospheric along-stream ageostrophic front arc entrained into the PBL. This process amplifies the bore-induced hydrostatic dryline bulge via low-level ageostrophic confluence. Finally, regions of low Richardson number (arising from strong vertical shears) within the amplifying midtropospheric along-stream ageostrophic thermally-indirect circulation become preferred regions for the development of non-hydrostatic evanescent internal gravity waves. These waves are embedded within the hydrostatic along-stream front above the low-level dryline and are accomapanied by very significant values of vertical momentum flux which act to focus the meso-gamma scale structure of the dryline into smaller scale bulges where low-level winds and vorticities are very high. This meso-gamma scale process follows the hydrostatic tilting and vortex tube stretching which creates meso-beta scale maxima of mid-lower tropospheric vorticity. The turbulent momentum fluxes accompanying wavebreaking within the nonhydrostatic dryline bulge create very large (i.e., stratospheric values of) potential vorticity near 70 kPa due to the nonconservation of potential vorticity on isentropic surfaces. C1 NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,ATMOSPHERES LAB,GREENBELT,MD 20771. RP KAPLAN, ML (reprint author), N CAROLINA STATE UNIV,DEPT MARINE EARTH & ATMOSPHER SCI,RALEIGH,NC 27695, USA. NR 17 TC 15 Z9 15 U1 0 U2 2 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 1992 VL 49 IS 1-4 BP 157 EP 185 DI 10.1007/BF01025406 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA KB664 UT WOS:A1992KB66400010 ER PT J AU PRABHAKARA, C DALU, G SUHASINI, R NUCCIARONE, JJ LIBERTI, GL AF PRABHAKARA, C DALU, G SUHASINI, R NUCCIARONE, JJ LIBERTI, GL TI RAINFALL OVER OCEANS - REMOTE-SENSING FROM SATELLITE MICROWAVE RADIOMETERS SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID ATMOSPHERIC WATER-VAPOR; PRECIPITATING CLOUD; NIMBUS-7 SMMR; CONVECTIVE RAINFALL; RADIATIVE-TRANSFER; LIQUID WATER; WIND-SPEED; EL NINO; RATES; SPACE AB Microwave radiometer brightness temperature (T(b)) measurements obtained from satellites over the oceans in dual polarization, at frequencies ranging from 6.6 to 85 GHz, reveal information about the rain and precipitation sized ice. These multifrequency measurements are composited from observations made by the Scanning Multichannel Microwave Radiometer (SMMR) and the Special Sensor Microwave/Imager (SSM/I). The T(b) measurements at 37 GHz, having a field of view (fov) of about 30 km, show relatively strong emissions due to rain, reaching values as large as 260 K over the tropical and mid-latitude rainbelts. Only marginal effects due to scattering by ice above the rain clouds are revealed. At frequencies below 37 GHz, where the fov is much larger than 30 km and the extinction is weaker, T(b) is significantly smaller than 260 K. Additional information content about rain, at these low frequencies, is not appreciable. On the other hand, at 85 GHz (fov congruent-to 15 km), where the extinction is very strong, the sea surface below the clouds is often masked and scattering due to ice above the rain clouds is vividly noticed. However, these high frequency measurements do not yield direct information about rain below the clouds. Recognizing the above merits inherent in the 37 GHz observations the SMMR and SSM/I data at this frequency are utilized to develop an empirical method to retrieve rain rate over oceans. In this method it is assumed that over an oceanic area, the statistics of the observed T(b) must be derivable from the statistics of the corresponding rain rates. Furthermore, the underestimation of rain rate, arising from the inability of the radiometer to respond sensitively to rain above a given threshold is empirically rectified with the help of two parameters that depend on the total water vapor content in the atmosphere. Rain rates deduced over the oceans around Japan using the SSM/I data, when compared with those measured by radars that are calibrated against rain gauges, show a good correlation; there is, however, a systematic overestimation. Seasonal mean maps of the rainfall over the global oceans based on SMMR data compare favorably with climatological rain maps over the Atlantic and Pacific Oceans developed by Dorman and Bourke (1979, 1981). C1 IST FIS ATMOSFERA,ROME,ITALY. NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. RP PRABHAKARA, C (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 913,GREENBELT,MD 20771, USA. RI Liberti, Gian Luigi/C-3331-2013; OI Liberti, Gian Luigi/0000-0002-1906-5248; LIBERTI, GIANLUIGI/0000-0003-0091-8607 NR 48 TC 13 Z9 13 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 1992 VL 47 IS 2-4 BP 177 EP 199 DI 10.1007/BF01025616 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA JF254 UT WOS:A1992JF25400008 ER PT J AU ROTTMAN, JW EINAUDI, F KOCH, SE CLARK, WL AF ROTTMAN, JW EINAUDI, F KOCH, SE CLARK, WL TI A CASE-STUDY OF PENETRATIVE CONVECTION AND GRAVITY-WAVES OVER THE PROFS MESONETWORK ON 23 JULY 1983 SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID MULTISCALE STATISTICAL-ANALYSIS; MESOSCALE; DISTURBANCES; COLORADO; CCOPE; FLOW AB This paper describes the evolution of two thunderstorms which developed over northeastern Colorado on 23 July 1983, and more significantly discusses the possible causal relationship between them. In particular, a disturbance apparently created by the first thunderstorm, which developed over the eastern slopes of the Rocky mountains, seems to have triggered the second thunderstorm, which developed further east over the high plains. We present evidence that suggests that the disturbance is a rapidly propagating gravity wave (possibly a solitary wave of depression) that occupied most of the troposphere and was generated by the explosive convective development of the first thunderstorm. Detailed observations of the interactions between these two storms were possible because both storms developed over a dense network of automated weather stations that provided high temporal and spatial resolution surface measurements of pressure, temperature, precipitation, and horizontal wind velocity. Also located within this mesonetwork was a high power 915 MHz wind profiler that provided radial velocities throughout most of the troposphere. These measurements were supplemented with GOES visible and infrared satellite imagery and operational data from National Weather Service rawinsondes and weather radars. C1 NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771. NOAA,AERON LAB,BOULDER,CO 80303. RP ROTTMAN, JW (reprint author), NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,GREENBELT,MD 20771, USA. NR 25 TC 4 Z9 4 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 1992 VL 47 IS 2-4 BP 205 EP 227 DI 10.1007/BF01025618 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA JF254 UT WOS:A1992JF25400010 ER PT J AU ANDERSSON, BG WANNIER, PG LEWIS, BM AF ANDERSSON, BG WANNIER, PG LEWIS, BM TI AN UPPER LIMIT TO THE HYDROXYL ABUNDANCE IN THE CIRCUMSTELLAR ENVELOPE OF IRC + 10216 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article ID IRC+10216; MODELS; OH AB We have searched for thermal OH emission from IRC + 10216 in the 1665- and 1667-MHz lines. No emission was detected, yielding an upper limit for the OH abundance in the envelope. Within the photodissociation region where OH is expected to occur, [OH]/[CO] < 2.7 x 10(-3). C1 ARECIBO OBSERV,ARECIBO,PR 00613. CHALMERS UNIV TECHNOL UNIV GOTEBORG,S-41296 GOTHENBURG,SWEDEN. RP ANDERSSON, BG (reprint author), CALTECH,JET PROP LAB,MAIL STOP 169-506,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN 1 PY 1992 VL 254 IS 1 BP 7 EP 8 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA GW807 UT WOS:A1992GW80700002 ER PT J AU LAPENTA, WM SEAMAN, NL AF LAPENTA, WM SEAMAN, NL TI A NUMERICAL INVESTIGATION OF EAST-COAST CYCLOGENESIS DURING THE COLD-AIR DAMMING EVENT OF 27-28 FEBRUARY 1982 .2. IMPORTANCE OF PHYSICAL-MECHANISMS SO MONTHLY WEATHER REVIEW LA English DT Article ID SIMULATIONS; CIRCULATION; GALE-IOP-2; STORM; JET AB On 27-28 February 1982 cyclogenesis occurred along a Carolina coastal front. Despite the relatively weak low pressure center typical of many coastal storms, this case produced widespread hazardous conditions-within 12 h up to 30 cm of snow fell in the mountains of western Virginia and moderate icing persisted throughout 27 February in the Carolinas. The event contained many mesoscale and synoptic-scale phenomena such as cold-air damming, coastal frontogenesis, upper- and lower-tropospheric jet streaks, a thermally direct vertical-transverse ageostrophic circulation, and heavy mixed precipitation. A nested version of the PSU-NCAR three-dimensional mesoscale model with 35-km resolution successfully reproduced most principal synoptic and mesoscale features associated with the event. This study presents a series of numerical experiments designed to examine the role of several physical processes on the evolution of and interaction between atmospheric phenomena having differing scales, each of which contributed to the development of the storm. In particular, the physical processes studied include: 1) the role of diabatic heating associated with convective and grid-scale precipitation, 2) the role of a thermally direct transverse circulation about the entrance region of a strong polar jet streak, and 3) modification of the marine planetary boundary layer by fluxes of heat and moisture over the Gulf Stream. Of the three mechanisms investigated, the diabatic heating associated with precipitation is found to have the most significant impact on storm development. Without latent heating, cyclogenesis does not occur along the Carolina coastal front despite the presence of strong low-level baroclinicity and cyclonic vorticity. A less dramatic but still important relationship is found between storm formation and the other two physical mechanisms. The experiments indicate that the timing of storm development is delayed and the intensity weakened by reducing the strength of both the polar jet streak and fluxes over the Gulf Stream. In particular, weakening these processes disrupts the positive phase relationship between upper- and lower-tropospheric forcing in the last 12 h of the study. The three basic mechanisms are shown to affect the cyclogenesis by altering many of the important mesoscale features and processes that contribute to storm development, including the intensity of the vertical-transverse circulation around the jet streak, the location of the upward branch of the circulation, precipitation intensity, buoyancy of parcels advected over the coastal front, low-level and upper-level height falls associated with latent heating, and the southeasterly low-level jet over the coastal front. C1 PENN STATE UNIV,DEPT METEOROL,UNIV PK,PA 16802. RP LAPENTA, WM (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,DIV EARTH SCI & APPLICAT,ES242,HUNTSVILLE,AL 35812, USA. NR 19 TC 20 Z9 21 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JAN PY 1992 VL 120 IS 1 BP 52 EP 76 DI 10.1175/1520-0493(1992)120<0052:ANIOEC>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HB424 UT WOS:A1992HB42400004 ER PT J AU STEENROD, SD ROOD, RB LAMICH, DJ ROSENFIELD, JE GOVINDARAJU, RC AF STEENROD, SD ROOD, RB LAMICH, DJ ROSENFIELD, JE GOVINDARAJU, RC TI THE MINOR STRATOSPHERIC WARMING OF JANUARY 1989 - RESULTS FROM STRATAN, A STRATOSPHERIC TROPOSPHERIC DATA ASSIMILATION SYSTEM SO MONTHLY WEATHER REVIEW LA English DT Note ID TEMPERATURES AB Using a stratospheric-tropospheric data assimilation system, referred to as STRATAN, a minor sudden stratospheric warming that occurred in January 1989 is investigated. The event had a maximum influence on the stratospheric circulation near 2 hPa. The zonal mean circulation reversed briefly in the polar region as the temperature increased 34 K in 3 days. The cause of the warming is shown to be the rapid development and subsequent movement of a warm anomaly, which initially developed in the midlatitudes. The development of the warm anomaly is caused by adiabatic descent, and the dissipation by radiative cooling. A brief comparison with the NMC analysis and temperature sounding data is also presented. C1 NASA,GODDARD SPACE FLIGHT CTR,APPL CHEM & DYNAM BRANCH,GREENBELT,MD 20771. APPL RES CORP,LANDOVER,MD. GEN SCI CORP,LAUREL,MD. NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771. RI Steenrod, Stephen/H-2218-2012; Rood, Richard/C-5611-2008 OI Rood, Richard/0000-0002-2310-4262 NR 13 TC 3 Z9 3 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JAN PY 1992 VL 120 IS 1 BP 221 EP 229 DI 10.1175/1520-0493(1992)120<0221:TMSWOJ>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HB424 UT WOS:A1992HB42400015 ER PT B AU WATSON, JW WORKMAN, IK HATAWAY, BD AF WATSON, JW WORKMAN, IK HATAWAY, BD GP MAROME TECHNOL SOC TI THE BEHAVIOR OF FISH AND SHRIMP ENCOUNTERING TRAWLS IN THE SOUTHEASTERN UNITED-STATES PENAEID SHRIMP FISHERY SO MTS '92 - GLOBAL OCEAN PARTNERSHIP, PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1992 Marine-Technology-Society Conference on Global Ocean Partnership CY OCT 19-21, 1992 CL WASHINGTON, DC SP MARINE TECHNOL SOC C1 US DEPT COMMERCE,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MISSISSIPPI LABS,PASCAGOULA,MS 39568. NR 0 TC 4 Z9 4 U1 0 U2 1 PU MARINE TECHNOLOGY SOC PI WASHINGTON PA 1828 L ST NW, 9TH FL, WASHINGTON, DC 20036 BN 0-933957-11-4 PY 1992 BP 336 EP 341 PG 6 WC Engineering, Environmental; Engineering, Marine; Environmental Sciences; Oceanography SC Engineering; Environmental Sciences & Ecology; Oceanography GA BC83X UT WOS:A1992BC83X00050 ER PT J AU TOOMARIAN, NB BARHEN, J AF TOOMARIAN, NB BARHEN, J TI LEARNING A TRAJECTORY USING ADJOINT FUNCTIONS AND TEACHER FORCING SO NEURAL NETWORKS LA English DT Article DE TEMPORAL LEARNING; TRAJECTORY LEARNING; ADJOINT OPERATORS; TEACHER FORCING; RECURRENT NETWORKS ID NEURAL NETWORKS AB A new methodology for faster supervised temporal learning in nonlinear neural networks is presented. It builds upon the concept of adjoint operators, to enable a fast computation of the gradients of an error functional with respect to all parameters of the neural architecture, and exploits the concept of teacher forcing to incorporate information regarding the desired output into the activation dynamics. The importance of the initial or final time conditions for the adjoint equations (i.e., the error propagation equations) is discussed. A new algorithm is presented, in which the adjoint equations are solved simultaneously (i.e., forward in time) with the activation dynamics of the neural network. We also indicate how teacher forcing can be modulated in time as learning proceeds. The algorithm is illustrated by examples. The results show that the learning time is reduced by one to two orders of magnitude with respect to previously published results, while trajectory tracking is significantly improved. The proposed methodology makes hardware implementation of temporal learning attractive for real-time applications. C1 JET PROP LAB,DIV ENGN & APPL SCI,PASADENA,CA 91109. RP TOOMARIAN, NB (reprint author), JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109, USA. NR 21 TC 30 Z9 30 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0893-6080 J9 NEURAL NETWORKS JI Neural Netw. PY 1992 VL 5 IS 3 BP 473 EP 484 PG 12 WC Computer Science, Artificial Intelligence SC Computer Science GA HY508 UT WOS:A1992HY50800009 ER PT J AU CHANG, ATC TSANG, L AF CHANG, ATC TSANG, L TI A NEURAL NETWORK APPROACH TO INVERSION OF SNOW WATER EQUIVALENT FROM PASSIVE MICROWAVE MEASUREMENTS SO NORDIC HYDROLOGY LA English DT Article AB The inversion of snow water equivalent, SWE, from passive microwave remote sensing measurements may be accomplished by using a neural network trained with a dense media multiple scattering model. Brightness temperatures from 19 GHz vertical and horizontal polarizations, 22 GHz vertical polarization and 37 GHz vertical and horizontal polarizations which are available from the SSM/I sensors, are used as input to the neural network. The percentage error for estimated SWE varies from 9 % to 57 % for different snow conditions. RP CHANG, ATC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HYDROL SCI BRANCH,GREENBELT,MD 20771, USA. NR 0 TC 20 Z9 23 U1 0 U2 0 PU NORDISK ASSN HYDROLOGY PI DK LYNGBY PA TECHNICAL UNIV DENMARK BUILDING 115, 2800 DK LYNGBY, DENMARK SN 0029-1277 J9 NORD HYDROL JI Nord. Hydrol. PY 1992 VL 23 IS 3 BP 173 EP 182 PG 10 WC Water Resources SC Water Resources GA JQ285 UT WOS:A1992JQ28500003 ER PT J AU TRAJMAR, S AF TRAJMAR, S TI ELECTRON COLLISION PROCESSES WITH PLASMA EDGE NEUTRALS SO NUCLEAR FUSION LA English DT Review ID EXCITATION CROSS-SECTIONS; INTERMEDIATE-ENERGY REGION; IMPACT-EXCITATION; ATOMIC OXYGEN; VIBRATIONAL-EXCITATION; ELASTIC-SCATTERING; INCIDENT ENERGIES; METASTABLE STATES; LYMAN-ALPHA; MOLECULES AB Experimental techniques for measuring electron-atom (molecule) collision cross-sections, which are needed in studies of fusion edge plasmas, are briefly described. A survey of available data is given and gaps in the required database are pointed out. A few remarks on the present status of the theory for calculating electron collision cross-sections are made and it is emphasized that a joint experimental and theoretical effort is required for substantial progress in satisfying the data needs. RP TRAJMAR, S (reprint author), JET PROP LAB,PASADENA,CA 91109, USA. NR 107 TC 1 Z9 1 U1 0 U2 0 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PY 1992 VL 2 SU S BP 15 EP 23 PG 9 WC Physics, Fluids & Plasmas SC Physics GA JM108 UT WOS:A1992JM10800002 ER PT J AU DAR, A RAMATY, R AF DAR, A RAMATY, R TI NEUTRINOS FROM OPTICALLY QUIET BIRTHS OF NEUTRON-STARS SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2ND INTERNATIONAL WORKSHOP ON THEORETICAL AND PHENOMENOLOGICAL ASPECTS OF UNDERGROUND PHYSICS ( TAUP 91 ) CY SEP 09-13, 1991 CL TOLEDO, SPAIN SP UNIV ZARAGOZA, SPANISH COMM SCI & TECHNOL, MINIST SCI & EDUC SPAIN, AUTONOMOUS GOVT ARAGON, RES ADVISORY COMM, UNIV VALENCIA, UNIV CASTILLA LAMANCHA ID GAMMA-RAY BURSTS; STELLAR-CORE COLLAPSE; ANNIHILATION; SUPERNOVAE; GALAXIES; PULSARS AB Accretion of matter onto the surface of a white dwarf in a binary system can push it over the Chandrasekhar mass limit and may cause it to collapse into a naked or nearly naked neutron star without detectable optical emission1-3. Such optically quiet neutron star births should be accompanied by neutrino bursts which could be detected with underground neutrino detectors if the collapse took place in our own Galaxy or in very close nearby galaxies4. However, the frequency of such collapses is not known. It has been shown that the neutrino burst from gravitational core collapse produces, through neutrino-antineutrino annihilation outside the neutron star, an enormous burst of electron-positron pairs and gamma rays5,6. Here we show that if the mass surrounding the newly formed neutron star is less than about 3 x 10(-4) M., the resultant gamma ray burst can be observed out to distances of at least 300 Mpc, and, consequently, that the observed rate of gamma ray bursts7 limits the birthrate of such nearly naked neutron stars to about 1 per 10(3) years in galaxies similar to ours. Additional limits are set by the observed flux of 0.511 MeV Galactic annihilation radiation8 and by the cosmic ray data. These rates are too small to contribute significantly to the birthrate of pulsars. They also imply that it is very unlikely that a neutrino burst unaccompanied by optical emission will be detected in the near future by underground detectors. RP DAR, A (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. NR 27 TC 0 Z9 0 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 PY 1992 SU 28A BP 401 EP 404 DI 10.1016/0920-5632(92)90203-5 PG 4 WC Physics, Particles & Fields SC Physics GA JZ403 UT WOS:A1992JZ40300064 ER PT J AU ROBBINS, DE AF ROBBINS, DE TI SPACE RADIATION - EDITORIAL SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Editorial Material RP ROBBINS, DE (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 3 EP 3 PG 1 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000002 ER PT J AU BADHWAR, GD KONRADI, A HARDY, A BRABY, LA AF BADHWAR, GD KONRADI, A HARDY, A BRABY, LA TI ACTIVE DOSIMETRIC MEASUREMENTS ON SHUTTLE FLIGHTS SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article AB A tissue-equivalent proportional counter spectrometer capable of measuring the absorbed dose and dose distribution as a function of linear energy transfer (LET) and time, for all penetrating radiation in space, is described. This instrument weighs about 0.7 kg and was flown on the STS-31 (28.5-degrees x 620 km) flight of the Space Shuttle, 24-29 April 1990. The measured total dose is in excellent agreement with the calculations based on the AP8MAX model of the trapped radiation belt protons. The observed LET frequency distribution is also in excellent agreement with calculations based on this model. Active instruments can provide more detailed dosimetry for crew risk assessment than the thermoluminescent detectors or a plastic track detector system. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP BADHWAR, GD (reprint author), NASA, LYNDON B JOHNSON SPACE CTR, NATL AERONAUT & SPACE ADM, HOUSTON, TX 77058 USA. NR 12 TC 27 Z9 27 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 13 EP 20 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000004 ER PT J AU KEITH, JE BADHWAR, GD LINDSTROM, DJ AF KEITH, JE BADHWAR, GD LINDSTROM, DJ TI NEUTRON-SPECTRUM AND DOSE-EQUIVALENT IN SHUTTLE FLIGHTS DURING SOLAR MAXIMUM SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article AB This paper presents unambiguous measurements of the spectrum of neutrons found in spacecraft during spaceflight. The neutron spectrum was measured from thermal energies to about 10 MeV using a completely passive system of metal foils as neutron detectors. These foils were exposed to the neutron flux bare, covered by thermal neutron absorbers (Gd) and inside moderators (Bonner spheres). This set of detectors was flown on three U.S. Space Shuttle flights, STS-28, STS-36 and STS-31, during the solar maximum. We show that the measurements of the radioactivity of these foils lead to a differential neutron energy spectrum in all three flights that can be represented by a power law, J(E) congruent-to E-0.765 neutrons cm-2 day-1 MeV-1. We also show that the measurements are even better represented by a linear combination of the terrestrial neutron albedo and a spectrum of neutrons locally produced in aluminum by protons, computed from the HETC code. We use both approximations to the neutron spectrum to produce a worst case and most probable case for the neutron spectra and the resulting dose-equivalents, computed using ICRP-51 neutron fluence-dose conversion tables. We compare these to the skin dose-equivalents due to charged particles during the same flights. RP KEITH, JE (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 24 TC 23 Z9 23 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 41 EP 47 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000009 ER PT J AU KONRADI, A ATWELL, W BADHWAR, GD CASH, BL HARDY, KA AF KONRADI, A ATWELL, W BADHWAR, GD CASH, BL HARDY, KA TI LOW EARTH ORBIT RADIATION-DOSE DISTRIBUTION IN A PHANTOM HEAD SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article AB In order to compare analytical methods with data obtained during exposure to space radiation, a phantom head instrumented with a large number of radiation detectors was flown on the Space Shuttle on three occasions: 8 August 1989 (STS-28), 28 February 1990 (STS-36), and 24 April 1990 (STS-31). The objective of this experiment was to obtain a measurement of the inhomogeneity in the dose distribution within a phantom head volume. The orbits of these missions were complementary-STS-28 and STS-36 had high inclination and low altitude, while STS-31 had a low inclination and high altitude. In the cases of STS-28 and STS-36, the main contribution to the radiation dose comes from galactic cosmic rays (GCR) with a minor to negligible part supplied by the inner belt through the South Atlantic Anomaly (SAA), and for STS-28 an even smaller one from a proton enhancement during a solar flare-associated proton event. For STS-31, the inner belt protons dominate and the GCR contribution is almost negligible. The internal dose distribution is consistent with the mass distribution of the orbiter and the self-shielding and physical location of the phantom head. C1 ROCKWELL INT CORP,HOUSTON,TX 77058. LOCKHEED,EMSC,HOUSTON,TX 77058. USAF,SCH AEROSP MED,BROOKS AFB,TX 78235. RP KONRADI, A (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 7 TC 21 Z9 22 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 49 EP 54 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000010 ER PT J AU TOWNSEND, LW WILSON, JW CUCINOTTA, FA SHINN, JL AF TOWNSEND, LW WILSON, JW CUCINOTTA, FA SHINN, JL TI GALACTIC COSMIC-RAY TRANSPORT METHODS AND RADIATION QUALITY ISSUES SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article ID HEAVY-ION FRAGMENTATION; CROSS-SECTIONS; MODEL AB An overview of galactic cosmic ray (GCR) interaction and transport methods, as implemented in the Langley Research Center GCR transport code, is presented. Representative results for solar minimum, exo-magnetospheric GCR dose equivalents in water are presented on a component by component basis for various thicknesses of aluminum shielding. The impact of proposed changes to the currently used quality factors on exposure estimates and shielding requirements are quantified. Using the cellular track model of Katz, estimates of relative biological effectiveness (RBE) for the mixed GCR radiation fields are also made. RP TOWNSEND, LW (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 493,HAMPTON,VA 23665, USA. NR 29 TC 8 Z9 8 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 65 EP 72 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000013 ER PT J AU BENTON, EV HEINRICH, W PARNELL, TA ARMSTRONG, TW DERRICKSON, JH FISHMAN, GJ FRANK, AL WATTS, JW WIEGEL, B AF BENTON, EV HEINRICH, W PARNELL, TA ARMSTRONG, TW DERRICKSON, JH FISHMAN, GJ FRANK, AL WATTS, JW WIEGEL, B TI IONIZING-RADIATION EXPOSURE OF LDEF - (PRE-RECOVERY ESTIMATES) SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article ID SPECTRA; SOLAR AB The long duration exposure facility (LDEF), launched into a 258 nautical mile orbit with an inclination of 28.5-degrees, remained in space for nearly 6 yr. The 21,500 lb NASA satellite was one of the largest payloads ever deployed by the Space Shuttle. LDEF completed 32,422 orbits and carried 57 major experiments representing more than 200 investigators from 33 private companies, 21 universities and nine countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, material, structures and power and propulsion. A number of the experiments were specifically designed to measure the radiation environment. These experiments are of specific interest, since the LDEF orbit is essentially the same as that of the Space Station Freedom. Consequently, the radiation measurments on LDEF will play a significant role in the design of radiation shielding of the space station. The contributions of the various authors presented here attempt to predict the major aspects of the radiation exposure received by the various LDEF experiments and therefore should be helpful to investigators who are in the process of analyzing experiments which may have been affected by exposure to ionizing radiation. The paper discusses the various types and sources of ionizing radiation including cosmic rays, trapped particles (both protons and electrons) and secondary particles (including neutrons, spallation products and high-LET recoils), as well as doses and LET spectra as a function of shielding. Projections of the induced radioactivity of LDEF are also discussed. C1 UNIV SIEGEN,DEPT PHYS,W-5900 SIEGEN,GERMANY. SAIC,PROSPECT,TN 38477. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP BENTON, EV (reprint author), UNIV SAN FRANCISCO,DEPT PHYS,SAN FRANCISCO,CA 94117, USA. NR 64 TC 15 Z9 15 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 75 EP 100 PG 26 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000014 ER PT J AU HARMON, BA FISHMAN, GJ PARNELL, TA BENTON, EV FRANK, AL AF HARMON, BA FISHMAN, GJ PARNELL, TA BENTON, EV FRANK, AL TI LDEF RADIATION MEASUREMENTS - PRELIMINARY-RESULTS SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article AB The Long Duration Exposure Facility (LDEF), retrieved by the Space Shuttle mission STS-32 after nearly 6 yr in orbit, is the focus of a broad-based study of the radiation environment in low Earth orbit (LEO) and its effects on materials. A combination of passive techniques has been used to study this environment via detectors which were contained in experiments aboard the LDEF spacecraft and through analysis of induced radioactivities. Preliminary results for absorbed dose measurements and for induced activities in various materials are presented. A number of effects have been observed which reflect the anisotropy of the charged particle flux in low Earth orbit. Quantitative results from these measurements should provide an accurate means of confirming environmental flux models and techniques for predicting radiation encountered in future LEO missions, particularly those of extended duration. C1 UNIV SAN FRANCISCO,DEPT PHYS,SAN FRANCISCO,CA 94117. RP HARMON, BA (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,E562,HUNTSVILLE,AL 35812, USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 131 EP 136 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000016 ER PT J AU DUDKIN, VE KARPOV, ON POTAPOV, YV AKOPOVA, AB MAGRADZE, NV MOISEENKO, AA BENTON, EV FRANK, AL WATTS, JW AF DUDKIN, VE KARPOV, ON POTAPOV, YV AKOPOVA, AB MAGRADZE, NV MOISEENKO, AA BENTON, EV FRANK, AL WATTS, JW TI EXPERIMENTAL AND CALCULATED LET DISTRIBUTIONS IN THE COSMOS-2044 BIOSATELLITE ORBIT SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article AB During the flight of the Cosmos-2044 biosatellite, joint U.S.S.R.-U.S.A. investigations of different characteristics of cosmic radiation (CR) in the near-Earth environment were carried out. The U.S. dielectric track detectors CR-39 and Soviet BYa- and BR-type nuclear photo-emulsions were used as detectors. The present work shows some results of experimental measurements of linear energy transfer (LET) spectra of CR particles obtained with the use of these detectors, which were placed both inside and outside the satellite. The LET spectra measurement with plastic detectors is composed of two parts: the measurement of galactic cosmic rays (GCR) particles, and of short-range particles. The contributions of these components to the total LET distribution at various thicknesses of the shielding were analyzed and the results of these studies are presented. Calculated LET spectra in the Cosmos-2044 orbit were compared with experimental data. On the basis of experimental and calculated values of the LET spectra, absorbed and equivalent CR doses were calculated. In the shielding range of 1-1.5 g cm-2, outside the spacecraft, the photo-emulsions yielded 10.3 mrad d-1 and 27.5 mrem d-1 (LET greater-than-or-equal-to 2 MeV cm-1) while the CR-39 yielded averages of 1.43 mrad d-1 and 13.4 mrem d-1 (LET greater-than-or-equal-to 40 MeV cm-1). Inside the spacecraft (greater-than-or-equal-to 10 g cm-2) the photo-emulsions yielded 8.9 mrad d-1 and 14.5 mrem d-1. C1 YEREVAN INST PHYS,YEREVAN,USSR. UNIV SAN FRANCISCO,SAN FRANCISCO,CA 94117. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP DUDKIN, VE (reprint author), MINIST PUBL HLTH USSR,SPACE CRAFT RADIAT SAFETY RES CTR,MOSCOW 123182,USSR. NR 6 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 143 EP 147 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000018 ER PT J AU DUDKIN, VE KOVALEV, EE POTAPOV, YV BENTON, EV FRANK, AL BENTON, ER WATTS, JW PARNELL, TA SCHOPPER, E BAICAN, B REITZ, G BUCKER, H FACIUS, R BEAUJEAN, R HEILMANN, C AF DUDKIN, VE KOVALEV, EE POTAPOV, YV BENTON, EV FRANK, AL BENTON, ER WATTS, JW PARNELL, TA SCHOPPER, E BAICAN, B REITZ, G BUCKER, H FACIUS, R BEAUJEAN, R HEILMANN, C TI COSMIC-RAY LET SPECTRA AND DOSES ON BOARD COSMOS-2044 BIOSATELLITE SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article ID LINEAR ENERGY-TRANSFER; RADIATION; ABOARD; NUCLEI; SPACE AB Results of the experiments on board Cosmos-2044 (Biosatellite 9) are presented. Various nuclear track detectors (NTD) (dielectric, AgCl-based, nuclear emulsions) were used to obtain the LET spectra inside and outside the statellite. The spectra from the different NTDs have proved to be in general agreement. The results of LET spectra calculations using two different models are also presented. The resultant LET distributions are used to calculate the absorbed and equivalent doses and the orbit-averaged quality factors (QF) of the cosmic rays (CR). Absorbed dose rates inside (approximately 20 g cm-2 shielding) and outside (1 g cm-2) the spacecraft, omitting electrons, were found to be 4.8 and 8.6 mrad d-1, respectively, while the corresponding equivalent doses were 8.8 and 19.7 mrem d-1. The effects of the flight parameters on the total fluence of, and on the dose from, the CR particles are analyzed. Integral dose distributions of the detected particles are also determined. The LET values which separate absorbed and equivalent doses into 50% intervals are estimated. The CR-39 dielectric NTD is shown to detect 20-30% of the absorbed dose and 60-70% of the equivalent dose in the Cosmos-2044 orbit. The influence of solar activity phase on the magnitude of CR flux is discussed. C1 DLR INST AEROSP MED,COLOGNE,GERMANY. UNIV SAN FRANCISCO,SAN FRANCISCO,CA 94117. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. UNIV KIEL,W-2300 KIEL 1,GERMANY. CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. RP DUDKIN, VE (reprint author), MINIST PUBL HLTH USSR,SPACE FLIGHT RADIAT SAFETY RES CTR,MOSCOW 123182,USSR. NR 23 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 149 EP 155 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000019 ER PT J AU CUCINOTTA, FA WILSON, JW TOWNSEND, LW SHINN, JL KATZ, R AF CUCINOTTA, FA WILSON, JW TOWNSEND, LW SHINN, JL KATZ, R TI TRACK STRUCTURE MODEL FOR DAMAGE TO MAMMALIAN-CELL CULTURES DURING SOLAR PROTON EVENTS SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article AB Solar proton events (SPEs) occur infrequently and unpredictably, thus representing a potential hazard to interplanetary space missions. Biological damage from SPEs will be produced principally through secondary electron production in tissue, including important contributions due to delta rays from nuclear reaction products. We review methods for estimating the biological effectiveness of SPEs using a high energy proton model and the parametric cellular track model. Results of the model are presented for several of the historically largest flares using typical levels and body shielding. C1 UNIV NEBRASKA,LINCOLN,NE 68588. RP CUCINOTTA, FA (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 493,HAMPTON,VA 23665, USA. NR 32 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 177 EP 184 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000024 ER PT J AU NELSON, GA SCHUBERT, WW MARSHALL, TM AF NELSON, GA SCHUBERT, WW MARSHALL, TM TI RADIOBIOLOGICAL STUDIES WITH THE NEMATODE CAENORHABDITIS-ELEGANS - GENETIC AND DEVELOPMENTAL EFFECTS OF HIGH LET RADIATION SO NUCLEAR TRACKS AND RADIATION MEASUREMENTS LA English DT Article ID MUTAGENESIS; MUTANTS AB The biological effects of heavy charged particle (HZE) radiation are of particular interest to travellers and planners for long-duration space flights where exposure levels represent a potential health hazard. The unique feature of HZE radiation is the structured pattern of its energy deposition in targets. There are many consequences of this feature to biological endpoints when compared with effects of ionizing photons. Dose vs response and dose-rate kinetics may be modified, DNA and cellular repair systems may be altered in their abilities to cope with damage, and the qualitative features of damage may be unique for different ions. The nematode Caenorhabditis elegans is being used to address these and related questions associated with exposure to radiation. HZE-induced mutation, chromosome aberration, cell inactivation and altered organogenesis are discussed along with plans for radiobiological experiments in space. RP NELSON, GA (reprint author), CALTECH,JET PROP LAB,SPACE BIOL SCI GRP,PASADENA,CA 91109, USA. NR 18 TC 8 Z9 8 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-245X J9 NUCL TRACKS RAD MEAS PD JAN PY 1992 VL 20 IS 1 BP 227 EP 232 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA HD670 UT WOS:A1992HD67000028 ER PT J AU KERKHOVEN, T SAAD, Y AF KERKHOVEN, T SAAD, Y TI ON ACCELERATION METHODS FOR COUPLED NONLINEAR ELLIPTIC-SYSTEMS SO NUMERISCHE MATHEMATIK LA English DT Article ID CONVERGENCE; ALGORITHM; SIMULATION; EQUATIONS; ITERATION; MATRICES AB We compare both numerically and theoretically three techniques for accelerating the convergence of a nonlinear fixed point iteration u -> T(u), arising from a coupled elliptic system: Chebyshev acceleration, a second order stationary method, and a nonlinear version of the Generalized Minimal Residual Algorithm (GMRES) which we call NLGMR. All three approaches are implemented in 'Jacobian-free' mode, i.e., only a subroutine which returns T(u) as a function of u is required. We present a set of numerical comparisons for the drift-diffusion semiconductor model. For the mapping T which corresponds to the nonlinear block Gauss-Seidel algorithm for the solution of this nonlinear elliptic system, NLGMR is found to be superior to the second order stationary method and the Chebychev acceleration. We analyze the local convergence of the nonlinear iterations in terms of the spectrum sigma[T(u)(u(*))] of the derivative T(u) at the solution u(*). The convergence of the original iteration is governed by the spectral radius rho[T(U)(u(*))]. In contrast, the convergence of the two second order accelerations are related to the convex hull of sigma[T(u)(u(*))], while the convergence of the GMRES-based approach is related to the local clustering in sigma[I - T(u)(u(*))]. The spectrum sigma[I - T(u)(u(*))] clusters only at 1 due to the successive inversions of elliptic partial differential equations in T. We explain the observed superiority of GMRES over the second order acceleration by its ability to take advantage of this clustering feature, which is shared by similar coupled nonlinear elliptic systems. C1 NASA,AMES RES CTR,ADV COMP SCI RES INST,MOFFETT FIELD,CA 94035. RP KERKHOVEN, T (reprint author), UNIV ILLINOIS,DEPT COMP SCI,1304 W SPRINGFIELD AVE,URBANA,IL 61801, USA. NR 48 TC 31 Z9 31 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0029-599X J9 NUMER MATH JI Numer. Math. PD JAN PY 1992 VL 60 IS 4 BP 525 EP 548 PG 24 WC Mathematics, Applied SC Mathematics GA HA227 UT WOS:A1992HA22700006 ER PT J AU LANE, HW AF LANE, HW TI NUTRITION IN SPACE - EVIDENCE FROM THE UNITED-STATES AND THE USSR SO NUTRITION REVIEWS LA English DT Review ID SPACEFLIGHT AB Space flight exposes humans to a hostile, stressful environment as well as to the weightlessness associated with microgravity. The stresses of space travel affect nutritional balance, as evidenced by interrelated changes in body composition, energy utilization, and endocrine function. The limited data gathered thus far suggest that space flight incurs acute decreases in fluid mass and chronic, ongoing changes in muscle and bone mass. Concurrent with these changes is an increase in energy used per unit body mass. Other preliminary data suggest that bed rest and space flight may incur increased sensitivity to insulin. Further research is needed to determine the human energy and protein requirements for space, as well as a means of quantifying changes in body composition during extended-duration space flight. RP LANE, HW (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,BIOMED OPERAT & RES BRANCH,MAIL CODE SD4,HOUSTON,TX 77058, USA. NR 17 TC 6 Z9 6 U1 1 U2 1 PU INT LIFE SCIENCES INST PI LAWRENCE PA 810 EAST 10TH ST SUBSCRIPTION OFFICE, LAWRENCE, KS 66044 SN 0029-6643 J9 NUTR REV JI Nutr. Rev. PD JAN PY 1992 VL 50 IS 1 BP 3 EP 6 PG 4 WC Nutrition & Dietetics SC Nutrition & Dietetics GA HA894 UT WOS:A1992HA89400001 PM 1579269 ER PT J AU ORLIC, M GACIC, M LAVIOLETTE, PE AF ORLIC, M GACIC, M LAVIOLETTE, PE TI THE CURRENTS AND CIRCULATION OF THE ADRIATIC SEA SO OCEANOLOGICA ACTA LA English DT Article ID DENSE WATER; FIELD OBSERVATIONS; BOTTOM; WINTER; WIND; SHELF; VARIABILITY; GIBRALTAR; MEDALPEX; PATTERNS AB This paper reviews the present state of knowledge of the Adriatic general circulation and its higher-frequency current variability. All studies show that the surface circulation consists of a large-scale cyclonic meander with several smaller cells embedded in it, and that the circulation system is modulated seasonally. Water mass analyses and direct current measurements indicate that the cyclonic meander also occurs in the intermediate layer, dominated by the current that inflows along the eastern coast. In the bottom layer, an outflowing current pressed against the western coast prevails. The circulation patterns are constantly perturbed by the higher-frequency current variations. Tidal currents modify the mean, residual flow rather weakly. On the other hand, winds have recently emerged as an important driving force, causing transient currents which may surpass in order of magnitude all the other contributions to the Adriatic current field. It has been found that the wind-driven currents are controlled by vorticity of the wind field, and that under the summer, stratified conditions, wind pulses may trigger oscillations of the inertia period. The physical processes occurring along the two opposing coasts of the Adriatic Sea differ markedly in their characteristics. Water exchange between the semienclosed basins of the eastern coast and the open sea is mainly forced by the local wind. Conversely, the shelf area along the western coast is dominated by the Po River outflow, which in winter mostly remains confined to a coastal boundary layer, whereas in summer it spreads to the open sea as well. Critical gaps in the present knowledge are identified, and ways of approaching them are suggested. Future work must specifically address the question of the relative importance of different forcing mechanisms in driving the Adriatic general circulation. Special attention must be paid to the exchange of water through the Otranto Strait and its relation to the rate of dense water formation in the Adriatic. The relative contribution of different water masses to the formation of the outflowing Adriatic water should be assessed. Combined modelling efforts, satellite data analysis and in situ measurements are suggested to study the rather poorly known mesoscale features and processes. C1 INST OCEANOG & FISHERIES,YU-58000 CROATIA,YUGOSLAVIA. MISSISSIPPI STATE UNIV,STENNIS SPACE CTR,RES CTR,MISSISSIPPI STATE,MS 39529. RP ORLIC, M (reprint author), UNIV ZAGREB,DIV SCI,ANDRIJA MOHOROVICIC GEOPHYS INST,POB 224,YU-41000 ZAGREB,YUGOSLAVIA. RI Orlic, Mirko/J-3861-2012 OI Orlic, Mirko/0000-0002-1978-7208 NR 110 TC 229 Z9 233 U1 0 U2 9 PU GAUTHIER-VILLARS PI PARIS PA S P E S-JOURNAL DEPT, 120 BD ST GERMAIN, F-75006 PARIS, FRANCE SN 0399-1784 J9 OCEANOL ACTA JI Oceanol. Acta PY 1992 VL 15 IS 2 BP 109 EP 124 PG 16 WC Oceanography SC Oceanography GA JE815 UT WOS:A1992JE81500001 ER PT J AU SANCHEZ, BV RAY, RD CARTWRIGHT, DE AF SANCHEZ, BV RAY, RD CARTWRIGHT, DE TI A PROUDMAN-FUNCTION EXPANSION OF THE M2 TIDE IN THE MEDITERRANEAN-SEA FROM SATELLITE ALTIMETRY AND COASTAL GAUGES SO OCEANOLOGICA ACTA LA English DT Article ID GEOSAT ALTIMETRY; OCEANIC TIDES; STRAIT; LEVEL AB An empirical model has been derived for the semidiurnal principal lunar tide M2 in the Mediterranean Sea, excluding the Aegean Sea. The work is primarily an exercise in combining satellite altimeter data with tide-gauge data, through the use of specially constructed spatial basis functions. The tide-gauge data consist of M2 harmonic constants previously derived at 43 chosen coastal locations. The altimeter data consist of approximately two years of Geosat data in the form of collinear differences of sea-surface heights, corrected for orbit error by adjusting long sequences of global data. The tide is expressed as an expansion in Proudman functions - numerically constructed, orthogonal eigenfunctions of the velocity potential. The most important mode is found to be one of period 11.2 hours, presumably owing to its closeness to the tidal excitation frequency. The resulting M2 model is shown to be superior to a previous altimeter-based model that had been derived without benefit of spatial basis functions. C1 STX,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP SANCHEZ, BV (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 926,GREENBELT,MD 20771, USA. RI Ray, Richard/D-1034-2012; Sanchez, Braulio/I-5952-2013 NR 37 TC 16 Z9 16 U1 0 U2 2 PU GAUTHIER-VILLARS PI PARIS PA S P E S-JOURNAL DEPT, 120 BD ST GERMAIN, F-75006 PARIS, FRANCE SN 0399-1784 J9 OCEANOL ACTA JI Oceanol. Acta PY 1992 VL 15 IS 4 BP 325 EP 337 PG 13 WC Oceanography SC Oceanography GA JU566 UT WOS:A1992JU56600001 ER PT J AU ARNAULT, S PERIGAUD, C AF ARNAULT, S PERIGAUD, C TI ALTIMETRY AND MODELS IN THE TROPICAL OCEANS - A REVIEW SO OCEANOLOGICA ACTA LA English DT Review ID GENERAL-CIRCULATION MODEL; SEA-SURFACE TEMPERATURE; NORTH EQUATORIAL COUNTERCURRENT; PACIFIC-OCEAN; ATLANTIC-OCEAN; SOUTHERN OSCILLATION; DATA ASSIMILATION; SEASONAL VARIABILITY; INDIAN-OCEAN; EL-NINO AB Tropical oceans play a key role in climatic variations. Ocean-atmosphere interactions induce large-scale and low-frequency variations which, due to the specificity of tropical ocean dynamics, are very difficult to observe with traditional in situ measurements. During the past twenty years, a variety of numerical models of diverse complexity have contributed much to the description, understanding and prediction of ocean variability in the tropics. However, the capacity of these models to simulate adequately the ocean variability heavily depends on the accuracy of the atmospheric forcings and that of initial conditions. Satellite altimetry provides a unique opportunity to avoid the problem of scarce and non-synoptic in situ data coverage for the large-scale low-frequency monitoring of the tropical oceans. Preliminary results have been obtained with Geos 3 and Seasat altimeter data acquired in the late 1970s. The most recent demonstration of such a capacity is the multi-year Geosat mission of the late 1980s. However the use.of the sea level variations monitored by Geosat for ocean description is severely limited by the lack of accuracy of the mission dedicated to geodesy. Such a limitation will no longer exist after the launch in 1992 of the Topex-Poseidon satellite which is dedicated to oceanography. Nonetheless these future satellite observations will not alone be sufficient to determine, for example, the oceanic transport of heat involved in climatic variations: it is in the combination of numerical models and altimetry that answers to such a question may lie. Data assimilation into numerical models is a fairly new adventure for oceanographers, the few examples of assimilation of actual altimetric data in the tropics being of very recent date. Different methods have been applied in these examples with different objectives of assimilation, indicating a variety of directions for future research in what is a promising field. C1 JET PROP LAB, PASADENA, CA 91109 USA. RP ARNAULT, S (reprint author), UNIV PARIS 06, ORSTOM, OCEANOG DYNAM & CLIMATOL LAB, CASE 100, 4 PL JUSSIEU, F-75252 PARIS 05, FRANCE. NR 125 TC 11 Z9 11 U1 0 U2 2 PU GAUTHIER-VILLARS/EDITIONS ELSEVIER PI PARIS PA 23 RUE LINOIS, 75015 PARIS, FRANCE SN 0399-1784 J9 OCEANOL ACTA JI Oceanol. Acta PY 1992 VL 15 IS 5 BP 411 EP 430 PG 20 WC Oceanography SC Oceanography GA KH980 UT WOS:A1992KH98000003 ER PT J AU PERIGAUD, C ZLOTNICKI, V AF PERIGAUD, C ZLOTNICKI, V TI IMPORTANCE OF GEOSAT ORBIT AND TIDAL ERRORS IN THE ESTIMATION OF LARGE-SCALE INDIAN-OCEAN VARIATIONS SO OCEANOLOGICA ACTA LA English DT Article ID ALTIMETER OBSERVATIONS; WAVES AB Geosat ERM data concerning the Indian Ocean over a period of 26 months were processed with two different techniques of orbit error reduction in order to improve the accuracy of estimates of large-scale meridional sea-level variations. The first technique removes an along-track polynomial of degree 1 over approximately 5,000 km; the second removes an along-track once-per-revolution sine wave (approximately 40,000 km). Averaged over the Indian Ocean, the difference between the two estimates represents 43 % of the total variance and 31 % of the annual variance. This difference contains both oceanic and error signals. Sea-level variations from both techniques show an error with a spectral peak at 7-degrees-6 zonal wavelength, 317-day period, propagating westward at 2.6 km/day. This error is caused by the M2 tidal signal being inaccurately corrected and then aliased by Geosat's sampling characteristics into low-frequency apparent sea-level variations. We remove the tidal error by filtering out the spectral peak in the frequency-zonal wave number and re-analyze the estimated sea level. The polynomial technique produces stronger attenuation of both the tidal error and the large-scale oceanic signal. The annual variance retained by the filter contains 9 and 14 % of the respective annual variances of the two techniques before filtering. After filtering, the residual difference between the two methods represents 44 % of the total variance and 23 % of the annual variance. The sine-wave method yields a larger estimate of annual and interrannual meridional variations. Driven by the monsoon, the difference in sea level between the northern and southern basins (over 10-degrees-20-degrees-S) decreases from May to November. This sea-level change is estimated at 19.6 cm and 15.6 cm by the two techniques. Similarly, in 1988 the sea level averaged from July to December is higher than in 1987 over the band from the equator to 10-degrees-N. This sea-level change is estimated at 3.0 and 1.0 cm by the two techniques. RP PERIGAUD, C (reprint author), JET PROP LAB,MS 300-323,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 28 TC 12 Z9 12 U1 0 U2 0 PU GAUTHIER-VILLARS PI PARIS PA S P E S-JOURNAL DEPT, 120 BD ST GERMAIN, F-75006 PARIS, FRANCE SN 0399-1784 J9 OCEANOL ACTA JI Oceanol. Acta PY 1992 VL 15 IS 5 BP 491 EP 505 PG 15 WC Oceanography SC Oceanography GA KH980 UT WOS:A1992KH98000009 ER PT J AU COX, DE AF COX, DE TI ACTIVE VIBRATION CONTROL USING A MODAL-DOMAIN FIBER OPTIC SENSOR SO OPTICAL ENGINEERING LA English DT Article DE SMART MATERIALS AND STRUCTURES; FIBER OPTIC SENSORS; PIEZOELECTRIC ACTUATORS; VIBRATION SUPPRESSION; FLEXIBLE STRUCTURES AB A closed-loop control experiment is described in which vibrations of a cantilevered beam are suppressed using measurements from a modal-domain fiber optic sensor. Modal-domain sensors use interference between the modes of a few-mode optical waveguide to detect strain. The fiber is bonded along the length of the beam and provides a measurement related to the strain distribution on the surface of the beam. A model for the fiber optic sensor is derived, and this model is integrated with the dynamic model of the beam. A piezoelectric actuator is also bonded to the beam and used to provide control forces. Control forces are obtained through dynamic compensation of the signal from the fiber optic sensor. The compensator is implemented with a real-time digital controller. Analytical models are verified by comparing simulations to experimental results for both open-loop and closed-loop configurations. RP COX, DE (reprint author), NASA,LANGLEY RES CTR,SPACECRAFT CONTROLS BRANCH,HAMPTON,VA 23665, USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU SOC PHOTO-OPT INSTRUM ENG PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD JAN PY 1992 VL 31 IS 1 BP 8 EP 12 DI 10.1117/12.56054 PG 5 WC Optics SC Optics GA GZ789 UT WOS:A1992GZ78900002 ER PT J AU KOPIA, LP LEE, RB AF KOPIA, LP LEE, RB TI THERMISTOR BOLOMETER SCANNING RADIOMETER - APPLICATIONS AND FLIGHT EXPERIENCE SO OPTICAL ENGINEERING LA English DT Article DE RADIOMETRY; THERMISTOR BOLOMETER; REMOTE SENSING; CALIBRATION ID RADIATION BUDGET EXPERIMENT; INSTRUMENT AB Orbital measurements of the Earth's long-wave emitted radiation, and the Sun's radiation reflected by the Earth have been made by scanning radiometers on three spacecraft platforms in both high-altitude Sun-synchronous polar (833 km) and low-altitude (600 km) equatorial orbits. The Earth Radiation Budget Satellite (ERBE) instruments have been designed to measure the radiance from the Earth with an absolute radiometric error of less than 1%. The scanner instruments consist of three broadband radiometer channels: short wave, 0.25 to 3.5-mu-m; long wave, 5.0 to 50-mu-m; and total, 0.25 to > 50-mu-m, and use thermistor bolometers as sensing elements. These radiometers repetitively scan the Earth from limb to limb every 4 s producing contiguous pixels on the Earth's surface. Each scan contains views of cold space and of an internal calibration source, to obtain a radiometric reference and a calibration check, respectively. The design and operation of the ERBE scanner are described, and an overview of the ground calibration approach and inflight calibration stability is given along with an analysis of on-orbit anomalous behavior. RP KOPIA, LP (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 13 TC 5 Z9 5 U1 0 U2 2 PU SOC PHOTO-OPT INSTRUM ENG PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD JAN PY 1992 VL 31 IS 1 BP 156 EP 165 DI 10.1117/12.56045 PG 10 WC Optics SC Optics GA GZ789 UT WOS:A1992GZ78900024 ER PT J AU CARR, LW YU, YH AF CARR, LW YU, YH TI THE USE OF INTERFEROMETRY IN THE STUDY OF ROTORCRAFT AERODYNAMICS SO OPTICS AND LASERS IN ENGINEERING LA English DT Article ID DYNAMIC STALL; AIRFOIL AB The application of interferometry techniques to analysis of aerodynamic flows on rotorcraft is reviewed, with emphasis on those studies which give insight into the character of the complex flows on helicopter rotor blades. In particular, blade-vortex interaction, dynamic stall, and transonic flow on rotor blades are reviewed, showing how interferometry offers new insight into the basic flow characteristics of these flows and presenting some of the correlations that have been made with the results of computational analysis. RP CARR, LW (reprint author), USA,ATCOM,NASA AMES RES CTR,AEROFLIGHTDYNAM DIRECTORATE,DIV FLUID MECH,MOFFETT FIELD,CA 94035, USA. NR 14 TC 2 Z9 2 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0143-8166 J9 OPT LASER ENG JI Opt. Lasers Eng. PY 1992 VL 17 IS 3-5 BP 121 EP 146 DI 10.1016/0143-8166(92)90032-3 PG 26 WC Optics SC Optics GA KB036 UT WOS:A1992KB03600002 ER PT J AU OBERBECK, VR AGGARWAL, H AF OBERBECK, VR AGGARWAL, H TI COMET IMPACTS AND CHEMICAL EVOLUTION ON THE BOMBARDED EARTH SO ORIGINS OF LIFE AND EVOLUTION OF THE BIOSPHERE LA English DT Article ID CRETACEOUS TERTIARY BOUNDARY; AMINO-ACIDS; ORGANIC-MOLECULES; LIFE; CONDENSATION; ORIGIN; POND; PRECURSORS; ATMOSPHERE; CHEMISTRY AB Amino acids yields for previously published shock tube experiments are used with minimum Cretaceous-Tertiary (K/T) impactor mass and comet composition to predict AIB amino acid K/T boundary sediment column density. The inferred initial concentration of all amino acids in the K/T sea and in similar primordial seas just after 10 km comet impacts would have been at least 10(-7) M. However, sinks for amino acids must also be considered in calculating amino acid concentrations after comet impacts and in assessing the contribution of comets to the origin of life. The changing concentration of cometary amino acids due to ultraviolet light is compared with the equilibrium concentration of amino acids produced in the sea from corona discharge in the atmosphere, deposition in water, and degradation by ultraviolet light. Comets could have been more important than endogenous agents for initial evolution of amino acids. Sites favorable for chemical evolution of amino acids are examined and it is concluded that chemical evolution could have occurred at or above the surface even during periods of intense bombardment of Earth before 3.8 billion years ago. C1 ELORET INST,SUNNYVALE,CA 94087. RP OBERBECK, VR (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 43 TC 18 Z9 19 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0169-6149 J9 ORIGINS LIFE EVOL B JI Orig. Life Evol. Biosph. PY 1992 VL 21 IS 5-6 BP 317 EP 338 PG 22 WC Biology SC Life Sciences & Biomedicine - Other Topics GA JV866 UT WOS:A1992JV86600005 ER PT J AU TOOMARIAN, N AF TOOMARIAN, N TI PATTERN-CLASSIFICATION USING THE PHASE-VELOCITY FIELD APPROACH SO PATTERN RECOGNITION LETTERS LA English DT Article AB A new concept for unsupervised learning based upon examples introduced to the neural network is proposed. Each example is considered as an interpolation node of the velocity field in the phase space. The velocities at these nodes are selected such that all the streamlines converge to an attracting set embedded in the subspace occupied by the cluster of examples. The unknown parameters are found from a learning procedure using the selected phase velocity field as an input. The theory is further ilucidated by an example. RP TOOMARIAN, N (reprint author), CALTECH,JET PROP LAB,CTR MICROELECTR TECHNOL,PASADENA,CA 91109, USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8655 J9 PATTERN RECOGN LETT JI Pattern Recognit. Lett. PD JAN PY 1992 VL 13 IS 1 BP 13 EP 17 DI 10.1016/0167-8655(92)90109-D PG 5 WC Computer Science, Artificial Intelligence SC Computer Science GA HG864 UT WOS:A1992HG86400002 ER PT J AU VEYSSIERE, P NOEBE, R AF VEYSSIERE, P NOEBE, R TI WEAK-BEAM STUDY OF [111] SUPERLATTICE DISLOCATIONS IN NIAL SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID SINGLE-CRYSTALS AB Superlattice dislocations with <111> Burgers vectors, introduced in NiAl single crystals by compression at room temperature, along the [001] crystal axis, are studied by weak-beam transmission electron microscopy. It is found that slip in the <111> direction occurs in a {112} plane. Dissociation, if any, does not exceed 1.5 nm, thus establishing a lower limit for the antiphase boundary energy on {011} and {112} planes at approximately 500 and 750 mJ m-2, respectively. Double images may arise under weak-beam conditions, due to double diffraction at the core of <111> superlattice dislocations. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP VEYSSIERE, P (reprint author), OFF NATL ETUD & RECH AEROSP,CNRS,LEM,BP 72,F-92322 CHATILLON,FRANCE. NR 20 TC 42 Z9 42 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD JAN PY 1992 VL 65 IS 1 BP 1 EP 13 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA GY509 UT WOS:A1992GY50900001 ER PT J AU VASQUEZ, RP HUNT, BD FOOTE, MC BAJUK, LJ OLSON, WL AF VASQUEZ, RP HUNT, BD FOOTE, MC BAJUK, LJ OLSON, WL TI X-RAY PHOTOELECTRON-SPECTROSCOPY STUDY OF INEQUIVALENT OXYGEN SITES IN HIGH-TEMPERATURE SUPERCONDUCTORS SO PHYSICA C LA English DT Article ID CA-CU-O; SINGLE-CRYSTALS; PHOTOEMISSION; YBA2CU3O7-X; BI2SR2CACU2O8; SPECTRA AB Differentiation of O is spectra from variable angle X-ray photoemission measurements on high temperature superconductors is used to distinguish oxygen signals from inequivalent lattice sites. Features which are apparent only as a shoulder or as asymmetry on the main O is peak in the measured spectra can be clearly resolved in the second derivatives. In addition to the signals from Cu-O planes and chains, the O is spectrum from YBa2Cu3O7-x exhibits an additional peak at higher binding energy which variable angle measurements show is surface-related and which is assigned as reconstruction of the surface-terminated Cu-O planes. The O is spectrum from Tl2Ba2CaCu2O8+x is resolvable into two components which variable angle measurements show are associated with Cu-O planes and with Tl-O bonding, with the surface being terminated in Tl-O bonds. C1 SUPERCOND TECHNOL INC,SANTA BARBARA,CA 93111. RP VASQUEZ, RP (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECTR TECHNOL,PASADENA,CA 91109, USA. NR 26 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JAN 1 PY 1992 VL 190 IS 3 BP 249 EP 254 DI 10.1016/0921-4534(92)90602-9 PG 6 WC Physics, Applied SC Physics GA HC669 UT WOS:A1992HC66900008 ER PT J AU BOZZOLO, G FERRANTE, J SMITH, JR AF BOZZOLO, G FERRANTE, J SMITH, JR TI METHOD FOR CALCULATING ALLOY ENERGETICS SO PHYSICAL REVIEW B LA English DT Note ID EMBEDDED-ATOM-METHOD; ELECTRONIC THEORY; PHASE-STABILITY; METAL ALLOYS; CU-AU; AG-AU; PD; NI AB A semiempirical method for the computation of alloy energies is introduced. It is based on the equivalent-crystal theory of defect-formation energies in elemental solids. The method is both simple and accurate. Heats of formation as a function of composition are computed for some binary alloys of Cu, Ni, Al, Ag, Pd, Pt, and Au using the heats of solution in the dilute limit as experimental input. The separation of heats into strain and chemical components helps in understanding the energetics. In addition, lattice-parameter contractions seen in solid solutions of Ag and Au are accurately predicted. Good agreement with experiment is obtained in all cases. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. GM CORP,RES LABS,DEPT PHYS,WARREN,MI 48090. RP BOZZOLO, G (reprint author), ANALEX CORP,3001 AEROSP PKWY,BROOK PK,OH 44142, USA. NR 16 TC 66 Z9 66 U1 2 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 1 PY 1992 VL 45 IS 1 BP 493 EP 496 DI 10.1103/PhysRevB.45.493 PG 4 WC Physics, Condensed Matter SC Physics GA GY516 UT WOS:A1992GY51600068 ER PT J AU ZANG, TA DAHLBURG, RB DAHLBURG, JP AF ZANG, TA DAHLBURG, RB DAHLBURG, JP TI DIRECT AND LARGE-EDDY SIMULATIONS OF 3-DIMENSIONAL COMPRESSIBLE NAVIER-STOKES TURBULENCE SO PHYSICS OF FLUIDS A-FLUID DYNAMICS LA English DT Article ID NUMERICAL-SIMULATION; SHEAR FLOWS AB This paper reports results from the numerical implementation and testing of the compressible large-eddy simulation (LES) model described by Speziale et al. [Phys. Fluids 31, 940 (1988)] and Erlebacher et al. (to appear in J. Fluid Mech.). Relevant quantities from 32(3) "coarse grid" LES solutions are compared with results generated from 96(3) direct numerical simulations (DNS) of three-dimensional compressible turbulence. It is found that the 32(3) LES results overall agree well with their 96(3) DNS counterparts. Moreover, the new DNS results confirm several recent conclusions about compressible turbulence that have been based primarily on two-dimensional simulations. C1 USN, RES LAB, COMPUTAT PHYS & FLUID DYNAM LAB, WASHINGTON, DC 20375 USA. RP ZANG, TA (reprint author), NASA, LANGLEY RES CTR, THEORET FLOW PHYS BRANCH, HAMPTON, VA 23665 USA. NR 28 TC 53 Z9 56 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0899-8213 J9 PHYS FLUIDS A-FLUID PD JAN PY 1992 VL 4 IS 1 BP 127 EP 140 DI 10.1063/1.858491 PG 14 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA GX510 UT WOS:A1992GX51000014 ER PT J AU GHOSH, S MATTHAEUS, WH AF GHOSH, S MATTHAEUS, WH TI LOW MACH NUMBER 2-DIMENSIONAL HYDRODYNAMIC TURBULENCE - ENERGY BUDGETS AND DENSITY-FLUCTUATIONS IN A POLYTROPIC FLUID SO PHYSICS OF FLUIDS A-FLUID DYNAMICS LA English DT Article ID MAGNETOHYDRODYNAMIC TURBULENCE; RELAXATION PROCESSES; MAGNETOFLUID; SPECTRA; FLOWS AB Theory suggests that three distinct types of turbulence can occur in the low Mach number limit of polytropic flow: nearly incompressible flows dominated by vorticity, nearly pure acoustic turbulence dominated by compression, and flows characterized by near statistical equipartition of vorticity and compressions. Distinctions between these kinds of turbulence are investigated here by direct numerical simulation of two-dimensional compressible hydrodynamic turbulence. Dynamical scalings of density fluctuations, examination of the ratio of transverse to longitudinal velocity fluctuations, and spectral decomposition of the fluctuations are employed to distinguish the nature of these low Mach number solutions. A strong dependence on the initial data is observed, as well as a tendency for enhanced effects of compressibility at later times and at higher wave numbers, as suggested by theories of nearly incompressible flows. C1 UNIV DELAWARE,BARTOL RES INST,NEWARK,DE 19716. RP GHOSH, S (reprint author), NASA,GODDARD SPACE FLIGHT CTR,USRA,GREENBELT,MD 20771, USA. NR 36 TC 23 Z9 23 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8213 J9 PHYS FLUIDS A-FLUID PD JAN PY 1992 VL 4 IS 1 BP 148 EP 164 DI 10.1063/1.858492 PG 17 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA GX510 UT WOS:A1992GX51000016 ER PT J AU BOYD, ID AF BOYD, ID TI ANALYSIS OF VIBRATION-DISSOCIATION-RECOMBINATION PROCESSES BEHIND STRONG SHOCK-WAVES OF NITROGEN SO PHYSICS OF FLUIDS A-FLUID DYNAMICS LA English DT Article ID NONEQUILIBRIUM; SIMULATION AB Computations are presented for the relaxation zone behind strong, one-dimensional shock waves of nitrogen. The numerical results are compared with existing experimental data. It is indicated that the derivation of chemical rate coefficients must account for the degree of vibrational nonequilibrium in the flow. A nonequilibrium chemistry model is employed together with equilibrium rate data to compute successfully the flow in several different nitrogen shock waves. The analysis is performed with the direct simulation Monte Carlo method (DSMC). The DSMC code is vectorized for efficient use on a supercomputer. The code simulates translational, rotational, and vibrational energy exchange, and dissociative and recombinative chemical reactions. A new model is proposed for the treatment of three-body recombinative collisions in the DSMC technique, which usually simulates binary collision events. The new formulation represents improvement over previous models in that it can be employed with a wide range of chemical rate data, does not introduce into the flow field troublesome pairs of atoms that may recombine upon further collision (pseudoparticles), and is compatible with the vectorized code. C1 NASA,AMES RES CTR,MS 230-2,MOFFETT FIELD,CA 94035. RP BOYD, ID (reprint author), ELORET INST,PALO ALTO,CA 94303, USA. NR 20 TC 30 Z9 30 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8213 J9 PHYS FLUIDS A-FLUID PD JAN PY 1992 VL 4 IS 1 BP 178 EP 185 DI 10.1063/1.858495 PG 8 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA GX510 UT WOS:A1992GX51000018 ER PT J AU MUSIELAK, ZE FONTENLA, JM MOORE, RL AF MUSIELAK, ZE FONTENLA, JM MOORE, RL TI KLEIN-GORDON EQUATION AND REFLECTION OF ALFVEN WAVES IN NONUNIFORM MEDIA SO PHYSICS OF FLUIDS B-PLASMA PHYSICS LA English DT Article ID MAGNETIC-FIELD; ISOTHERMAL ATMOSPHERE; MODES AB A new analytical approach is presented for assessing the reflection of linear Alfven waves in smoothly nonuniform media. The general one-dimensional case in Cartesian coordinates is treated. It is shown that the wave equations, upon transformation into the form of the Klein-Gordon equation, display a local critical frequency (OMEGA(c)) for reflection: At any location in the medium, reflection becomes strong as the wave frequency descends past this characteristic frequency set by the local nonuniformity of the medium. This critical frequency is given by the transformation as an explicit function of the Alfven velocity (V(A)), and its first (V(A)') and second (V(A)'') derivatives, and hence as an explicit spatial function. The transformation thus directly yields, without solution of the wave equations, the location in the medium at which an Alfven wave of any given frequency becomes strongly reflected and has its propagation practically cut off. The local critical frequency is the square root of the larger coefficient of the zeroth-order term in the two transformed wave equations; which equation has the larger coefficient is determined by the local nonuniformity. Hence, the critical frequency can switch from one equation to the other as the nonuniformity changes. Consequently, it is necessary to transform both wave equations to deduce that the critical frequency is OMEGA(c) = square-root (V(A)')2 + \2V(A) V(A)''\/2. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,ES 52,HUNTSVILLE,AL 35812. UNIV ALABAMA,DEPT MECH ENGN,HUNTSVILLE,AL 35899. RP MUSIELAK, ZE (reprint author), UNIV ALABAMA,CTR SPACE PLASMA & AERONOM,HUNTSVILLE,AL 35899, USA. NR 17 TC 50 Z9 50 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0899-8221 J9 PHYS FLUIDS B-PLASMA PD JAN PY 1992 VL 4 IS 1 BP 13 EP 18 DI 10.1063/1.860452 PG 6 WC Physics, Fluids & Plasmas SC Physics GA GX513 UT WOS:A1992GX51300004 ER PT B AU MADORE, BF AF MADORE, BF BE Thuan, TX Balkowski, C Van, JTT TI BOLOMETRIC HUBBLE TYPES FOR GALAXIES SO PHYSICS OF NEARBY GALAXIES: NATURE OR NURTURE? SE MORIOND ASTROPHYSICS MEETINGS LA English DT Proceedings Paper CT XXVIIth Moriond Meeting/XIIth Moriond Astrophysics Meeting - Physics of Nearby Galaxies: Nature or Nurture CY MAR 15-22, 1992 CL LES ARCS, FRANCE C1 JET PROP LAB,NASA,IPAC EXTRAGALACT DATABASE,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDITIONS FRONTIERES PI DREUX PA 7 AVENUE KENNEDY, 28100 DREUX, FRANCE BN 2-86332-124-2 J9 MORIOND AST PY 1992 BP 19 EP 24 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB01S UT WOS:A1992BB01S00002 ER PT B AU MADORE, BF AF MADORE, BF BE Thuan, TX Balkowski, C Van, JTT TI NASA IPAC EXTRAGALACTIC DATABASE SO PHYSICS OF NEARBY GALAXIES: NATURE OR NURTURE? SE MORIOND ASTROPHYSICS MEETINGS LA English DT Proceedings Paper CT XXVIIth Moriond Meeting/XIIth Moriond Astrophysics Meeting - Physics of Nearby Galaxies: Nature or Nurture CY MAR 15-22, 1992 CL LES ARCS, FRANCE C1 JET PROP LAB,NASA,IPAC EXTRAGALACT DATABASE,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDITIONS FRONTIERES PI DREUX PA 7 AVENUE KENNEDY, 28100 DREUX, FRANCE BN 2-86332-124-2 J9 MORIOND AST PY 1992 BP 25 EP 28 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BB01S UT WOS:A1992BB01S00003 ER PT J AU AIKIN, AC AF AIKIN, AC TI SPRING POLAR OZONE BEHAVIOR SO PLANETARY AND SPACE SCIENCE LA English DT Article ID ANTARCTIC OZONE; NITRIC-OXIDE; STRATOSPHERIC CLOUDS; HYDROGEN-CHLORIDE; MCMURDO STATION; SAGE-II; HOLE; DEPLETION; VORTEX; CHEMISTRY AB It has been recognized since the commencement of Antarctic ozone measurements during the IGY that spring southern polar total ozone amount is less than spring northern polar total ozone amount. More importantly, since 1980 there has been a decline in the minimum spring total ozone value. from 250 DU in 1980 to 125 DU in 1987 and below 120 in 1991. This decline occurs within the winter polar vortex, which acts as a containment vessel preventing polar ozone from escaping to lower latitudes and excluding ozone-rich air from the polar region. Ozone decrease can be explained in terms of heterogeneous reactions of chlorine and nitrogen reservoir molecules on polar stratospheric clouds. These clouds form in the lower polar stratosphere during winter when temperatures in the Antarctic are sufficiently low to create water ice clouds. Clouds involving nitric acid form at higher temperatures. Chlorine reservoirs such as HCl are converted to Cl2, which is photodissociated in the presence of sunlight. The resulting Cl reacts with O3 to form ClO. Measurements of ClO and other species give agreement of theory and experiment within the uncertainties of the measurement. Heterogeneous chemistry accounts for most of the ozone hole. A small amount of ozone loss is also observed above the polar stratospheric cloud level, implying another mechanism, either chemical or dynamical. Above 25 km, formation of ozone-destroying odd nitrogen in the upper stratosphere by energetic electrons and the existence of any trend is still an open question. There is much less ozone depletion in the Arctic. This is the result of a less stable polar vortex and warmer temperatures, which reduce polar stratospheric cloud formation. There is strong evidence that tropospheric forcing within or just outside the vortex leads to adiabatic cooling with resulting cloud formation. During such events ozone-poor tropospheric air is transported into the stratosphere. In the Arctic this can result in the transport of long-lived hydrocarbons. Subsequent reactions lead to the formation of HCl, reducing the effect of Cl. There is also production of HO2, which accelerates ozone loss due to chlorine. There are also small areas of large and rapid ozone depletion termed miniholes. Ozone-poor air from these regions can propagate to lower latitudes. as can the air from within the vortex. when it disintegrates in late spring. Data from the BUV ozone-measuring instrument on the Nimbus 4 satellite indicate the existence of October 1970 Antarctic ozone of only 250 DU. This is evidence of the existence of ozone loss with only CH3Cl and low concentrations of CFCs as chlorine sources. RP AIKIN, AC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,CODE 916,GREENBELT,MD 20771, USA. NR 95 TC 5 Z9 5 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 1992 VL 40 IS 1 BP 7 EP 26 DI 10.1016/0032-0633(92)90146-F PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HC563 UT WOS:A1992HC56300002 ER PT J AU KASPRZAK, WT NIEMANN, HB AF KASPRZAK, WT NIEMANN, HB TI EVIDENCE FOR ENHANCED DYNAMIC FLOW IN IONOSPHERIC HOLES FROM THE PIONEER VENUS ORBITER NEUTRAL MASS-SPECTROMETER SO PLANETARY AND SPACE SCIENCE LA English DT Article ID ENERGETIC IONS; NIGHTSIDE; PLASMA AB The Pioneer Venus Orbiter Neutral Mass Spectrometer (ONMS) was operated in ion mode during the third nightside cycle of the Orbiter around Venus. Data have been acquired for the outbound ionospheric holes on orbit numbers 530 and 531. Holes are observed as deep troughs in the electron and ion density in the antisolar ionosphere of Venus, primarily between 23 and 2 hours local solar time, usually in north south pairs and in conjunction with enhanced sunward or antisunward magnetic fields. Several models based on Orbiter data suggest that the holes are also regions of enhanced ion flow speeds. Spin modulated ion data acquired from the ONMS lor species He+, C+, N+ and O+, were reduced to obtain relative ion composition. The time of the maximum in the apparent ion flow observed in the spacecraft reference frame relative to that predicted by the spacecraft velocity is a measure of one component of the ion drift in the ecliptic plane. Although it is difficult to determine this component in the hole region due to the steep density gradients and low particle densities (< 10 cm(-3)), its minimum magnitude in the holes is of the order of 3 km s-1 for O+. This is larger than that observed in the ionosphere immediately surrounding the hole. The minimum ion drift speeds in the hole regions are largest for O+ and smallest for He+ with C+ and N+ intermediate. The concentrations of light ion species are enhanced relative to heavier species inside the hole as is evidenced by the increase in the He+/O+ ratio. The measurements of ion drift in the holes support the suggestion that they are regions of enhanced dynamic flow. Dynamic flows have also been measured in orbit 500 which has no outbound hole. An increase in the minimum flow speed to about 1 km s-1 is observed as the ionopause is approached from the ionosphere side. The implication is that ions are being accelerated out of the ionosphere by the electric and magnetic fields present in the ionosheath region. The direction of the ion flow cannot be determined but it can be bounded in the ecliptic plane. Ion flow directions for O+ inferred in this manner from the data are consistent with downward (toward Venus) flow within the outbound holes of orbits 530-531 and upward flow near the ionopause for orbit 500 without a hole. However, horizontal flow with a downward or upward component. respectively, cannot be excluded by the measurements. RP KASPRZAK, WT (reprint author), NASA,GODDARD SPACE FLIGHT CTR,PLANETARY ATMOSPHERES LAB,GREENBELT,MD 20771, USA. NR 25 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 1992 VL 40 IS 1 BP 33 EP 45 DI 10.1016/0032-0633(92)90148-H PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HC563 UT WOS:A1992HC56300004 ER PT J AU SEMENOV, VS KUBYSHKIN, IV LEBEDEVA, VV RIJNBEEK, RP HEYN, MF BIERNAT, HK FARRUGIA, CJ AF SEMENOV, VS KUBYSHKIN, IV LEBEDEVA, VV RIJNBEEK, RP HEYN, MF BIERNAT, HK FARRUGIA, CJ TI A COMPARISON AND REVIEW OF STEADY-STATE AND TIME-VARYING RECONNECTION SO PLANETARY AND SPACE SCIENCE LA English DT Article ID FLUX-TRANSFER EVENTS; MAGNETIC-FIELD RECONNECTION; DAYSIDE MAGNETOPAUSE; EARTHS MAGNETOPAUSE; ISEE OBSERVATIONS; SOLAR-WIND; PLASMA; MODELS; DISTRIBUTIONS; MAGNETOSPHERE AB Reconnection is a ubiquitous energy conversion process operating in current sheets. It appears in a variety of applications and is, for example. the dominant coupling process at the Earth's magnetopause. the current sheet which separates the solar wind and the terrestrial magnetosphere. Reconnection at the magnetopause is investigated theoretically and experimentally, and in both areas a division exists between so-called steady-state and time-dependent reconnection. In theoretical research the former is associated with the time-invariant analysis of Petschek and coworkers, and this is often put into contrast with an intrinsically time-varying process such as tearing. In experimental research, manifestations of reconnection have been classified either as large scale and (quasi) steady-state. or time dependent, with the former corresponding to accelerated plasma flows along the magnetopause, and the latter to the flux transfer event signature. This division is a source of confusion, in particular since it is unlikely that a true steady-state is ever achieved in nature. To clarify the relationship between steady-state and time-dependent reconnection we discuss here an extension of Petschek's analysis to include time variations in the reconnection rate. In this generalized analysis the reconnection electric field is imposed as an initial-boundary condition which can be specified as an arbitrary function of space and time. Different types of reconnection behaviour can therefore be investigated and we take advantage of this to compare steady-state and time-varying reconnection. We show that the former is just a special case of the latter and that there are no jumps in conceptual understanding required from one to the other. Furthermore. the time-dependent analysis is easily understood and gives a framework which unifies the interpretation of reconnection phenomena observed at the magnetopause. In particular, the theoretical results indicate that the same reconnection rate can give rise to both accelerated plasma flows and the flux transfer event signature; thus there is no physical reason to make a distinction in the underlying process giving rise to different reconnection phenomena. C1 UNIV ST ANDREWS,DEPT MATH SCI,FIFE KY16 9SS,SCOTLAND. AUSTRIAN ACAD SCI,INST SPACE RES,A-8010 GRAZ,AUSTRIA. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP SEMENOV, VS (reprint author), LENINGRAD STATE UNIV,DEPT PHYS,LENINGRAD 198904,USSR. RI Semenov, Vladimir/A-5530-2013; Kubyshkin, Igor/F-6243-2013; Lebedeva, Valentina/J-8618-2013 OI Semenov, Vladimir/0000-0001-6592-056X; Kubyshkin, Igor/0000-0001-9887-108X; NR 89 TC 43 Z9 43 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 1992 VL 40 IS 1 BP 63 EP 87 DI 10.1016/0032-0633(92)90150-M PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HC563 UT WOS:A1992HC56300006 ER PT J AU SMITH, JG CONNELL, JW HERGENROTHER, PM AF SMITH, JG CONNELL, JW HERGENROTHER, PM TI CHEMISTRY AND PROPERTIES OF POLY(ARYLENE ETHER BENZOXAZOLE)S SO POLYMER LA English DT Article DE AROMATIC POLYMER; POLY(ARYLENE ETHER BENZOXAZOLE); CHEMISTRY AB Novel poly(arylene ether benzoxazole)s were prepared by the aromatic nucleophilic displacement reaction of two new bis(hydroxyphenyl benzoxazole)s with activated aromatic difluorides. The bis(hydroxyphenyl benzoxazole)s were prepared from either 3,3'-dihydroxy-4,4'-diaminobiphenyl or 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and phenyl-4-hydroxybenzoate. The polymerizations were carried out in either N,N-dimethylacetamide or diphenylsulphone, depending on the bis(hydroxyphenyl benzoxazole). The polymers had glass transition temperatures ranging from 204 to 275-degrees-C and inherent viscosities from 0.25 to 1.04 dl g-1. Several of the polymers prepared from the 3,3'-dihydroxy-4,4'-diaminobiphenyl-derived bis(hydroxyphenyl benzoxazole) were semi-crystalline. Thermogravimetric analysis showed a 5% weight loss occurring at almost-equal-to 450-500-degrees-C in air and almost-equal-to 475-530-degrees-C in nitrogen. Thin films of the hexafluoroisopropylidene-containing polymers exhibited 23-degrees-C tensile strengths and moduli of 83-103 MPa and 1.9-2.4 GPa respectively, and high elongations. The chemistry and the physical and mechanical properties of these polymers are discussed. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 22 TC 29 Z9 29 U1 5 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0032-3861 J9 POLYMER JI Polymer PY 1992 VL 33 IS 8 BP 1742 EP 1747 DI 10.1016/0032-3861(92)91076-E PG 6 WC Polymer Science SC Polymer Science GA HW189 UT WOS:A1992HW18900026 ER PT J AU CONNELL, JW HERGENROTHER, PM WOLF, P AF CONNELL, JW HERGENROTHER, PM WOLF, P TI CHEMISTRY AND PROPERTIES OF POLY(ARYLENE ETHER 1,3,4-OXADIAZOLE)S AND POLY(ARYLENE ETHER 1,2,4-TRIAZOLE)S SO POLYMER LA English DT Article DE POLY(ARYLENE ETHER); POLYOXADIAZOLES; POLYTRIAZOLES; HIGH TEMPERATURE POLYMERS; ADHESIVES; FILMS AB Poly(arylene ether)s containing 1,3,4-oxadiazole and 1,2,4-triazole units were prepared by the aromatic nucleophilic displacement reaction of bisphenol oxadiazole and bisphenol triazole compounds with activated aromatic dihalides. The polymers exhibited glass transition temperatures (T(g)s) ranging from 182 to 242-degrees-C and several polymers exhibited melting transitions (T(m)s) ranging from 265 to 390-degrees-C. Inherent viscosities ranged from 1.02 to 3.40 dl g-1 indicating relatively high molecular weights. Thin films exhibited tensile strengths, moduli and elongations at 23-degrees-C of 90-110 MPa, 2.7-3.6 GPa and 4-7%, respectively. Titanium-to-titanium tensile shear specimens of a poly(arylene ether 1,3,4-oxadiazole) exhibited tensile shear strengths at 23 and 150-degrees-C of 22.1 and 17.9 MPa, respectively. C1 BASF AG,KUNSTSTOFFLAB,W-6700 LUDWIGSHAFEN,GERMANY. RP CONNELL, JW (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 23 TC 48 Z9 48 U1 4 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0032-3861 J9 POLYMER JI Polymer PY 1992 VL 33 IS 16 BP 3507 EP 3511 DI 10.1016/0032-3861(92)91111-E PG 5 WC Polymer Science SC Polymer Science GA JJ081 UT WOS:A1992JJ08100023 ER PT J AU CONNELL, JW HERGENROTHER, PM AF CONNELL, JW HERGENROTHER, PM TI SYNTHESIS OF POLY(ARYLENE ETHER)S CONTAINING QUINOXALINE UNITS SO POLYMER LA English DT Article DE POLY(ARYLENE ETHER)S; POLYQUINOXALINE; HIGH TEMPERATURE POLYMERS; FILMS AB Poly (arylene ether)s containing quinoxaline units were prepared by the aromatic nucleophilic displacement reaction of novel bis(phenolquinoxaline) compounds with activated aromatic difluoro compounds. Polymers prepared from bis(phenolquinoxaline)s that had configurational isomers were amorphous with inherent viscosity (eta(inh) from 0.34 to 1.30 dl g-1 and glass transition temperature (T(g)) from 213 to 283-degrees-C. Several polymers prepared from bis(phenolquinoxaline)s that did not contain configurational isomers were semicrystalline with eta(inh) from 0.24 to 0.83 dl g-1, T(g)s from 179 to 240-degrees-C and T(m)s from 365 to 388. The molecular weights of the semicrystalline polymers were limited by their solubility in the reaction media. RP CONNELL, JW (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 29 TC 23 Z9 23 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0032-3861 J9 POLYMER JI Polymer PY 1992 VL 33 IS 17 BP 3739 EP 3743 DI 10.1016/0032-3861(92)90665-J PG 5 WC Polymer Science SC Polymer Science GA JL836 UT WOS:A1992JL83600032 ER PT B AU MINTON, S DRUMMOND, M BRESINA, JL PHILIPS, AB AF MINTON, S DRUMMOND, M BRESINA, JL PHILIPS, AB BE Nebel, B Rich, C Swartout, W TI TOTAL ORDER VS PARTIAL ORDER PLANNING - FACTORS INFLUENCING PERFORMANCE SO PRINCIPLES OF KNOWLEDGE REPRESENTATION AND REASONING: PROCEEDINGS OF THE THIRD INTERNATIONAL CONFERENCE (KR 92) LA English DT Proceedings Paper CT 3rd International Conference on Principles of Knowledge Representation and Reasoning (KR 92) CY OCT 25-29, 1992 CL CAMBRIDGE, MA C1 NASA,AMES RES CTR,STERLING SOFTWARE INC,FED SYST GRP,MOFFETT FIELD,CA 94035. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MORGAN KAUFMANN PUB INC PI SAN MATEO PA 2929 CAMPUS DRIVE, SAN MATEO, CA 94403 BN 1-55860-262-3 PY 1992 BP 83 EP 92 PG 10 WC Computer Science, Artificial Intelligence SC Computer Science GA BA10M UT WOS:A1992BA10M00008 ER PT J AU PENG, RS WHITEOAK, JB REYNOLDS, JE KUIPER, TBH PETERS, WL AF PENG, RS WHITEOAK, JB REYNOLDS, JE KUIPER, TBH PETERS, WL TI OBSERVATIONS OF THE 18.3-GHZ TRANSITION OF C3H2 TOWARDS SGR B2 SO PROCEEDINGS ASTRONOMICAL SOCIETY OF AUSTRALIA LA English DT Article ID DARK CLOUDS; CYCLOPROPENYLIDENE; ABSORPTION; GALAXY AB We have mapped the molecular clouds of Sgr B2 in the 1(10) --> 1(01), ortho-transition of C3H2 at 18.3 GHz, using the 70-m NASA telescope at Tidbinbilla (beamwidth 55 arcsec). Three clouds show absorption against the Sgr B2 continuum emission at radial velocities of 50, 65 and 80 km s-1. The 65-km s-1 cloud covers most of the observed area (4 X 6 arcmin in right ascension and declination), has a peak optical depth of 2.7 and a corresponding C3H2 column density of 7.6 X 10(15) cm-2. The C3H2 fractional abundance relative to H-2 is 1.5 X 10(-9). The 80-km s-1 cloud, located north of the Sgr B2 continuum peak, has a peak optical depth of 0.9 and a C3H2 column density of 1.9 X 10(15) cm-2. The 50-km s-1 cloud is centred 2 arcmin south of the continuum peak; here the minimum optical depth of 0.5 yields a column density of 5.3 X 10(14) cm-2. C1 JET PROP LAB,PASADENA,CA 91109. UNIV ARIZONA,STEWARD OBSERV,TUCSON,AZ 85724. RP PENG, RS (reprint author), UNIV NSW,SCH PHYS,POB 1,KENSINGTON,NSW 2033,AUSTRALIA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU C S I R O PUBLICATIONS PI COLLINGWOOD PA 150 OXFORD ST, PO BOX 1139, COLLINGWOOD VICTORIA 3066, AUSTRALIA SN 0066-9997 J9 P ASTRON SOC AUST JI Proc. Astron. Soc. Aust. PY 1992 VL 10 IS 2 BP 113 EP 117 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KR780 UT WOS:A1992KR78000007 ER PT J AU FEGLEY, B TREIMAN, AH SHARPTON, VL AF FEGLEY, B TREIMAN, AH SHARPTON, VL TI VENUS SURFACE MINERALOGY - OBSERVATIONAL AND THEORETICAL CONSTRAINTS SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Review ID + CARBON-DIOXIDE; RADAR REFLECTIVITY; INITIAL ANALYSIS; MAGELLAN; WOLLASTONITE; CALCITE; QUARTZ; ATMOSPHERE; OXIDATION; VOLCANISM AB We utilize Earth-based, Earth-orbital, and spacecraft observations of the atmosphere and surface of Venus, thermodynamic models of atmosphere-lithosphere interactions, and where available kinetic data on relevant gas-solid reactions to place constraints on the mineralogy of the surface of Venus. We discuss which minerals and mineral assemblages are stable on the surface of Venus and which, if any, of these minerals are involved in controlling the abundances of reactive gases in the atmosphere of Venus. We conclude by identifying key issues facing us today about the mineralogy and geochemistry of the surface of Venus and suggest experimental, observational, and theoretical studies that can improve our knowledge of these important questions. C1 WASHINGTON UNIV,MCDONNELL CTR SPACE SCI,ST LOUIS,MO 63130. NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. LUNAR & PLANETARY INST,HOUSTON,TX 77058. RP FEGLEY, B (reprint author), WASHINGTON UNIV,DEPT EARTH & PLANETARY SCI,ST LOUIS,MO 63130, USA. NR 113 TC 27 Z9 27 U1 1 U2 4 PU LUNAR AND PLANETARY INST PI HOUSTON PA 3600 BAY AREA BLVD, HOUSTON, TX 77058 SN 0270-9511 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 3 EP 19 PG 17 WC Geosciences, Multidisciplinary SC Geology GA MG416 UT WOS:A1992MG41600001 ER PT J AU TROMBKA, JI EVANS, LG STARR, R FLOYD, SR SQUYRES, SW WHELAN, JT BAMFORD, GJ COLDWELL, RL RESTER, AC SURKOV, YA MOSKALEVA, LP KHARYUKOVA, VP MANVELYAN, OS ZAITSEVA, SY SMIRNOV, GG AF TROMBKA, JI EVANS, LG STARR, R FLOYD, SR SQUYRES, SW WHELAN, JT BAMFORD, GJ COLDWELL, RL RESTER, AC SURKOV, YA MOSKALEVA, LP KHARYUKOVA, VP MANVELYAN, OS ZAITSEVA, SY SMIRNOV, GG TI ANALYSIS OF PHOBOS MISSION GAMMA-RAY SPECTRA FROM MARS SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Article ID ROCKS AB The determination of the elemental composition of the surface of a planetary body can be achieved, in many cases, by remote-sensing gamma ray spectroscopy. A gamma ray spectrometer was carried on the Soviet spacecraft Phobos-2, and obtained data while in an elliptical orbit around Mars. Here we report on the results of two independent approaches to data analysis, one by the Soviet group and one by an American group. The results for five elements are given for two different orbits of Mars. Major geologic units that contribute to the signal for each orbit have been identified. The results from the two techniques are in general agreement and there appear to be no geologically significant differences between the results for each orbit. C1 COMP SCI CORP,SCI PROGRAMS,LANHAM,MD 20706. UNIV FLORIDA,INST ASTROPHYS & PLANETARY EXPLORAT,GAINESVILLE,FL 32615. CORNELL UNIV,CTR RADIOPHYS & SPACE RES,ITHACA,NY 14853. VI VERNADSKY GEOCHEM & ANALYT CHEM INST,MOSCOW,RUSSIA. CATHOLIC UNIV AMER,DEPT PHYS,WASHINGTON,DC 20064. RP TROMBKA, JI (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. NR 16 TC 12 Z9 12 U1 1 U2 1 PU LUNAR AND PLANETARY INST PI HOUSTON PA 3600 BAY AREA BLVD, HOUSTON, TX 77058 SN 0270-9511 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 23 EP 29 PG 7 WC Geosciences, Multidisciplinary SC Geology GA MG416 UT WOS:A1992MG41600002 ER PT J AU KELLER, LP MCKAY, DS AF KELLER, LP MCKAY, DS TI MICROMETER-SIZED GLASS SPHERES IN APOLLO-16 SOIL-61181 - IMPLICATIONS FOR IMPACT VOLATILIZATION AND CONDENSATION SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Article AB Micrometer-sized glass spheres from a mature highland lunar soil (61181) were analyzed for major elements with a transmission electron microscope. The majority of the glasses analyzed (50%) have refractory, high-alumina, silica-poor (HASP) compositions. Most of the HASP glasses are derived from the bulk soil by impact vaporization of silica, Fe, and volatile elements, Two HASP trends (a highland- and a mare-type) occur in the soil. A group of volatile-rich alumina-poor (VRAP) glasses were identified with compositions that are complementary to the HASP glasses. These VRAP glasses result from the condensation of impact-produced vapors. RP KELLER, LP (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,MAIL CODE SN14,HOUSTON,TX 77058, USA. NR 17 TC 19 Z9 19 U1 0 U2 1 PU LUNAR AND PLANETARY INST PI HOUSTON PA 3600 BAY AREA BLVD, HOUSTON, TX 77058 SN 0270-9511 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 137 EP 141 PG 5 WC Geosciences, Multidisciplinary SC Geology GA MG416 UT WOS:A1992MG41600012 ER PT J AU WIENS, RC BURNETT, DS NEUGEBAUER, M PEPIN, RO AF WIENS, RC BURNETT, DS NEUGEBAUER, M PEPIN, RO TI A COMPARISON OF SOLAR-WIND AND ESTIMATED SOLAR-SYSTEM XENON ABUNDANCES - A TEST FOR SOLID-GAS FRACTIONATION IN THE SOLAR NEBULA SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Article ID PARTICLES; CARBON; STARS AB Significant fractionation of dust/gas from the original interstellar cloud during the formation of the solar system is a distinct possibility. Identification of such an effect would provide important clues to nebular processes. Fractionation of volatiles is not constrained by CI abundances and only for the most abundant ones by photospheric observations. The solar Xe elemental abundance is determined here via solar wind measurements from lunar ilmenites and normalized to Si by spacecraft data. The results are compared vadi estimated abundances assuming no fractionation, which are relatively well constrained for Xe by s-process calculations, odd-mass abundance interpolations, and odd-even abundance systematics. When corrected for solar wind/photospheric fractionation, the Xe-130 abundance given by surface layer oxidation of ilmenite from soil 71501, exposed within the last approximately 200 m.y., is 0.24 +/- 0.09 normalized to Si = 10(6). This is indistinguishable from the estimates made assuming no solid/gas fractionation. A similar result was obtained for Kr by Wiens et al. (1991). Results from breccia 79035 ilmenite, exposed at least approximately 1 Gy ago, indicate that the solar wind Xe flux may have been significantly higher relative to other noble gases, perhaps due to more efficient Xe ionization. If this is true, fluxes of C and S, which have similar first ionization potentials to Xe, should also be higher in the ancient solar wind from the same time period, though such variations have not been observed. C1 JET PROP LAB, PASADENA, CA 91109 USA. UNIV MINNESOTA, SCH PHYS & ASTRON, MINNEAPOLIS, MN 55455 USA. RP WIENS, RC (reprint author), CALTECH, DIV GEOL & PLANETARY SCI, PASADENA, CA 91125 USA. NR 28 TC 2 Z9 2 U1 1 U2 4 PU LUNAR AND PLANETARY INST PI HOUSTON PA 3600 BAY AREA BLVD, HOUSTON, TX 77058 USA SN 0270-9511 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 153 EP 159 PG 7 WC Geosciences, Multidisciplinary SC Geology GA MG416 UT WOS:A1992MG41600014 ER PT J AU ZOLENSKY, ME LINDSTROM, DJ AF ZOLENSKY, ME LINDSTROM, DJ TI MINERALOGY OF 12 LARGE CHONDRITIC INTERPLANETARY DUST PARTICLES SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Article ID CARBONACEOUS CHONDRITE; AQUEOUS ALTERATION; MATRIX MINERALOGY; SEMARKONA; SMECTITE; ORIGIN AB We report here mineralogical analyses of 12 large ''chondritic'' interplanetary dust particles (IDPs). We find that nine of these particles belong to the smectite class of IDPs, and the remainder to the pyroxene class. In comparing our results to previous studies of generally smaller IDPs, we find a significantly higher percentage of smectite-class IDPs, which may therefore be a size-related phenomenon. We discuss the probable origin of these large IDPs, comparing hydrous to anhydrous particles. On the basis of mineralogical and compositional similarities we suggest that the bulk (at least) of pyroxene- and smectite-class IDPs have experienced similar or identical parent body processes, and are possibly derived from the same parent bodies. We note that it is commonly difficult to classify certain IDPs by the current scheme because of the presence of abundant amorphous materials and coexistence of both hydrous and anhydrous silicates. We suggest that the degree of compositional heterogeneity exhibited by anhydrous silicates could form the basis of an alternate IDP classification scheme. RP ZOLENSKY, ME (reprint author), NASA, PLANETARY SCI BRANCH, HOUSTON, TX 77058 USA. NR 28 TC 14 Z9 14 U1 1 U2 2 PU LUNAR AND PLANETARY INST PI HOUSTON PA 3600 BAY AREA BLVD, HOUSTON, TX 77058 SN 0270-9511 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 161 EP 169 PG 9 WC Geosciences, Multidisciplinary SC Geology GA MG416 UT WOS:A1992MG41600015 ER PT J AU BARRETT, RA ZOLENSKY, ME HORZ, F LINDSTROM, DJ GIBSON, EK AF BARRETT, RA ZOLENSKY, ME HORZ, F LINDSTROM, DJ GIBSON, EK TI SUITABILITY OF SILICA AEROGEL AS A CAPTURE MEDIUM FOR INTERPLANETARY DUST SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Article AB We report on a series of efforts to evaluate the suitability of silica aerogel as a capture medium for interplanetary dust particles on the space station Cosmic Dust Collection Facility. The structure of silica aerogel is such that even micrometer-sized hypervelocity particles will sense it as a target of very low density; consequently shock stresses and temperatures due to impact will be minimized. Silica aerogel can also contain inorganic contaminants at concentration levels below those of concern to the analysis of inorganic constituents of interplanetary dust. However, the measured concentrations of organic contaminants seem to limit its use for study of biogenic contaminants; future aerogel development must aim at reducing the concentration of organic contaminants. We also performed impact experiments in a light-gas gun that employed projectiles manufactured from forsterite, pyrrhotite, and calcite. From these experiments, we have developed techniques that will permit the successful extrication of interplanetary dust particles from aerogel. We note a rough correlation between increasing particle track lengths and decreasing aerogel density, and there is a poor correlation of track lengths with impact velocity at laboratory attainable velocities of 5-7 km/s. We conclude that aerogel track length should not be used as (crude) velocity indicators. Transmission electron microscope studies show that the recovered particulate residues are encased in melted silica aerogel, which possibly protects die residue from some impact damage. Individual minerals within interplanetary dust are expected to exhibit differential survival, and may be vaporized, melted, dehydrated, or structurally reordered. However, some mineral grains should successfully be captured unmelted at encounter velocities <8 km/s. C1 NASA,LYNDON B JOHNSON SPACE CTR,PLANETARY SCI BRANCH,HOUSTON,TX 77058. RP BARRETT, RA (reprint author), LOCKHEED ENGN & SCI CO,HOUSTON,TX 77058, USA. NR 14 TC 39 Z9 39 U1 0 U2 3 PU LUNAR AND PLANETARY INST PI HOUSTON PA 3600 BAY AREA BLVD, HOUSTON, TX 77058 SN 0270-9511 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 203 EP 212 PG 10 WC Geosciences, Multidisciplinary SC Geology GA MG416 UT WOS:A1992MG41600019 ER PT J AU COOMBS, CR HAWKE, BR AF COOMBS, CR HAWKE, BR TI PYROCLASTIC DEPOSITS ON THE WESTERN LIMB OF THE MOON SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Article ID REFLECTANCE AB Localized pyroclastic deposits are more common on the western limb of the Moon than once thought. We have conducted geologic and remote-sensing studies of 26 individual localized dark-mantle deposits in an elongated zone on the western limb. Seventeen of these deposits had not been previously identified. These deposits range in age from Imbrian to Eratosthenian and vary in size and thickness. We have separated the western limb deposits into three different ''zones'' of occurrence as a function of their position relative to the Orientale Basin impact structure: proximal zone, medial zone, and distal zone. Earth-based spectral reflectance data indicate that three distinct compositional groups are represented among the western limb pyroclastic deposits. Some of the pyroclastic material studied belongs to the Group 1 spectral class, and is rich in highland debris. Other mare-like deposits are part of the Group 2 spectral class, and the Cruger (Group 3) deposits are rich in olivine and pyroxene. The localized pyroclastic deposits on the western limb appear to be preserved in various stages of a formational sequence. An initial explosive phase was followed by varying amounts of mare flooding. In this scenario, both the pyroclastic and mare materials associated with individual volcanic complexes are products of the same parent magma and may have very similar compositions. This hypothesis can be tested with spectral data yet to be acquired for many of these western limb pyroclastic deposits. C1 UNIV HAWAII,SCH OCEAN & EARTH SCI & TECHNOL,DEPT GEOL & GEOPHYS,HONOLULU,HI 96822. NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. NR 33 TC 7 Z9 7 U1 0 U2 0 PU LUNAR AND PLANETARY INST PI HOUSTON PA 3600 BAY AREA BLVD, HOUSTON, TX 77058 SN 0270-9511 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 303 EP 312 PG 10 WC Geosciences, Multidisciplinary SC Geology GA MG416 UT WOS:A1992MG41600026 ER PT J AU WRIGHT, IP RUSSELL, SS BOYD, SR MEYER, C PILLINGER, CT AF WRIGHT, IP RUSSELL, SS BOYD, SR MEYER, C PILLINGER, CT TI XYLAN - A POTENTIAL CONTAMINANT FOR LUNAR-SAMPLES AND ANTARCTIC METEORITES SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Article ID NITROGEN; CARBON AB A proprietary lubricant paint, known as Xylan, has in the past been used to coat screw threads in the dry-N, sample-processing cabinets at the Planetary Materials Branch, NASA Johnson space Center (JSC). Xylan is a fluorinated polyimide-amide resin that polymerizes upon curing, the standard procedure used following its application. Unfortunately, Xylan that is either prepared or applied incorrectly does not adhere well to threaded components and consequently can become dislodged. This material therefore has to be considered a potential contaminant for those lunar samples and Antarctic meteorites that have been processed at JSC. Flakes of cured Xylan have been analyzed and found to contain 45 wt% C and 4 wt% N. A disturbing aspect of Xylan is that it is not fully removed during stepped combustion until temperatures in excess of 600-degrees-C are attained. Thus, during the investigation of elements such as C and N, interpretation of data obtained from lunar samples and meteorites at temperatures less than 600-degrees-C should be treated with some caution. Notwithstanding this, it is argued that the unexpectedly high concentration of organic materials found in EET A79001 are not due to Xylan contamination. Furthermore, it is considered unlikely that previous C and N analyses of lunar samples have been affected by the introduction of Xylan. Because of the identification of Xylan as a possible contaminant for light-element analyses, strenuous efforts have been expended at JSC in order to ensure its complete removal from the dry-N cabinets. C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. RP WRIGHT, IP (reprint author), OPEN UNIV,DEPT EARTH SCI,PLANETARY SCI UNIT,WALTON HALL,MILTON KEYNES MK7 6AA,BUCKS,ENGLAND. NR 16 TC 2 Z9 2 U1 0 U2 0 PU LUNAR AND PLANETARY INST PI HOUSTON PA 3600 BAY AREA BLVD, HOUSTON, TX 77058 SN 0270-9511 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 449 EP 458 PG 10 WC Geosciences, Multidisciplinary SC Geology GA MG416 UT WOS:A1992MG41600038 ER PT S AU TROMBKA, JI EVANS, LG STARR, R FLOYD, SR SQUYRES, SW WHELAN, JT BAMFORD, GJ COLDWELL, RL RESTER, AC SURKOV, YA MOSKALEVA, LP KHARYUKOVA, VP MANVELYAN, OS ZAITSEVA, SY SMIRNOV, GG AF TROMBKA, JI EVANS, LG STARR, R FLOYD, SR SQUYRES, SW WHELAN, JT BAMFORD, GJ COLDWELL, RL RESTER, AC SURKOV, YA MOSKALEVA, LP KHARYUKOVA, VP MANVELYAN, OS ZAITSEVA, SY SMIRNOV, GG BE Ryder, G Sharpton, VL TI ANALYSIS OF PHOBOS MISSION GAMMA-RAY SPECTRA FROM MARS SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE, VOL 22 SE PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Proceedings Paper CT 22ND ANNUAL LUNAR AND PLANETARY CONF CY MAR 18-22, 1991 CL HOUSTON, TX SP LUNAR & PLANETARY INST, NASA, JOHNSON SPACE CTR, AMER ASSOC PETR GEOLOGISTS, AMER GEOPHY UNION, AMER ASTRON SOC, DIV PLANETARY SCI, GEOL SOC AMER, INT UNION GEOL SCI, METEORIT SOC RP TROMBKA, JI (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. NR 0 TC 12 Z9 12 U1 1 U2 1 PU LUNAR & PLANETARY INST PI HOUSTON PA HOUSTON SN 0270-9511 BN 0-942862-06-6 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 23 EP 29 PG 7 WC Geosciences, Multidisciplinary SC Geology GA BZ04N UT WOS:A1992BZ04N00002 ER PT S AU KELLER, LP MCKAY, DS AF KELLER, LP MCKAY, DS BE Ryder, G Sharpton, VL TI MICROMETER-SIZED GLASS SPHERES IN APOLLO-16 SOIL-61181 - IMPLICATIONS FOR IMPACT VOLATILIZATION AND CONDENSATION SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE, VOL 22 SE PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Proceedings Paper CT 22ND ANNUAL LUNAR AND PLANETARY CONF CY MAR 18-22, 1991 CL HOUSTON, TX SP LUNAR & PLANETARY INST, NASA, JOHNSON SPACE CTR, AMER ASSOC PETR GEOLOGISTS, AMER GEOPHY UNION, AMER ASTRON SOC, DIV PLANETARY SCI, GEOL SOC AMER, INT UNION GEOL SCI, METEORIT SOC RP KELLER, LP (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,MAIL CODE SN14,HOUSTON,TX 77058, USA. NR 0 TC 19 Z9 19 U1 0 U2 1 PU LUNAR & PLANETARY INST PI HOUSTON PA HOUSTON SN 0270-9511 BN 0-942862-06-6 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 137 EP 141 PG 5 WC Geosciences, Multidisciplinary SC Geology GA BZ04N UT WOS:A1992BZ04N00012 ER PT S AU ZOLENSKY, ME LINDSTROM, DJ AF ZOLENSKY, ME LINDSTROM, DJ BE Ryder, G Sharpton, VL TI MINERALOGY OF 12 LARGE CHONDRITIC INTERPLANETARY DUST PARTICLES SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE, VOL 22 SE PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Proceedings Paper CT 22ND ANNUAL LUNAR AND PLANETARY CONF CY MAR 18-22, 1991 CL HOUSTON, TX SP LUNAR & PLANETARY INST, NASA, JOHNSON SPACE CTR, AMER ASSOC PETR GEOLOGISTS, AMER GEOPHY UNION, AMER ASTRON SOC, DIV PLANETARY SCI, GEOL SOC AMER, INT UNION GEOL SCI, METEORIT SOC RP ZOLENSKY, ME (reprint author), NASA,PLANETARY SCI BRANCH,HOUSTON,TX 77058, USA. NR 0 TC 14 Z9 14 U1 1 U2 2 PU LUNAR & PLANETARY INST PI HOUSTON PA HOUSTON SN 0270-9511 BN 0-942862-06-6 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 161 EP 169 PG 9 WC Geosciences, Multidisciplinary SC Geology GA BZ04N UT WOS:A1992BZ04N00015 ER PT S AU HIROI, T PIETERS, CM AF HIROI, T PIETERS, CM BE Ryder, G Sharpton, VL TI EFFECTS OF GRAIN-SIZE AND SHAPE IN MODELING REFLECTANCE SPECTRA OF MINERAL MIXTURES SO PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE, VOL 22 SE PROCEEDINGS OF LUNAR AND PLANETARY SCIENCE LA English DT Proceedings Paper CT 22ND ANNUAL LUNAR AND PLANETARY CONF CY MAR 18-22, 1991 CL HOUSTON, TX SP LUNAR & PLANETARY INST, NASA, JOHNSON SPACE CTR, AMER ASSOC PETR GEOLOGISTS, AMER GEOPHY UNION, AMER ASTRON SOC, DIV PLANETARY SCI, GEOL SOC AMER, INT UNION GEOL SCI, METEORIT SOC RP HIROI, T (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,MAIL CODE SN3,HOUSTON,TX 77058, USA. NR 0 TC 23 Z9 23 U1 0 U2 2 PU LUNAR & PLANETARY INST PI HOUSTON PA HOUSTON SN 0270-9511 BN 0-942862-06-6 J9 P LUNAR PLANET SCI PY 1992 VL 22 BP 313 EP 325 PG 13 WC Geosciences, Multidisciplinary SC Geology GA BZ04N UT WOS:A1992BZ04N00027 ER PT B AU SMITHRICK, JJ HALL, SW AF SMITHRICK, JJ HALL, SW GP CALIF STATE UNIV TI EFFECT OF KOH CONCENTRATION ON LEO CYCLE LIFE OF IPV NICKEL-HYDROGEN FLIGHT CELLS-UPDATE .2. SO PROCEEDINGS OF THE SEVENTH ANNUAL BATTERY CONFERENCE ON APPLICATIONS AND ADVANCES LA English DT Proceedings Paper CT 7th Annual Battery Conference on Applications and Advances CY JAN 21-23, 1992 CL LONG BEACH, CA SP CALIF STATE UNIV LONG BEACH, DEPT ELECT ENGN C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NR 0 TC 0 Z9 0 U1 0 U2 1 PU CALIFORNIA STATE UNIV CONSORTIUM PI LONG BEACH PA 1250 BELLFLOWER BLVD, LONG BEACH, CA 90840 PY 1992 BP 207 EP 215 DI 10.1017/CBO9780511523083.012 PG 9 WC Electrochemistry; Engineering, Electrical & Electronic SC Electrochemistry; Engineering GA BZ58H UT WOS:A1992BZ58H00020 ER PT J AU MORROW, BA KEIL, LC SEVERS, WB AF MORROW, BA KEIL, LC SEVERS, WB TI RESISTANCE TO OUTFLOW OF CEREBROSPINAL-FLUID AFTER CENTRAL INFUSIONS OF ANGIOTENSIN SO PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE LA English DT Article ID INTRACRANIAL HYPERTENSION; CONSCIOUS RATS; PRESSURE; VASOPRESSIN AB Infusions of artificial cerebrospinal fluid (CSF) into the cerebroventricles of conscious rats can raise CSF pressure (CSFp). This response can be modified by some neuropeptides. One of these, angiotensin, facilitates the rise in CSFp. We measured CSFp in conscious rats with a computerized system and evaluated resistance to CSF outflow during infusion of artificial CSF, with or without angiotensin, from the decay kinetics of superimposed bolus injections. Angiotensin (10 ng/min) raised CSFp (P < 0.05) compared with solvent, but the resistance to CSF outflow of the two groups was similar (P > 0.05). Because CSFp was increased by angiotensin without an increase in the outflow resistance, a change in some volume compartment is likely. Angiotensin may raise CSFp by increasing CSF synthesis; this possibility is supported, since the choroid plexuses contain an intrinsic isorenin-angiotensin system. Alternatively, angiotensin may dilate pial arteries, leading to an increased intracranial blood volume. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. PENN STATE UNIV,MILTON S HERSHEY MED CTR,COLL MED,HERSHEY MED CTR,DEPT PHARMACOL,HERSHEY,PA 17033. NR 22 TC 2 Z9 2 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 SN 0037-9727 J9 P SOC EXP BIOL MED JI Proc. Soc. Exp. Biol. Med. PD JAN PY 1992 VL 199 IS 1 BP 34 EP 37 PG 4 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA GW106 UT WOS:A1992GW10600004 PM 1728035 ER PT J AU FRENKLACH, M WANG, H RABINOWITZ, MJ AF FRENKLACH, M WANG, H RABINOWITZ, MJ TI OPTIMIZATION AND ANALYSIS OF LARGE CHEMICAL KINETIC MECHANISMS USING THE SOLUTION MAPPING METHOD - COMBUSTION OF METHANE SO PROGRESS IN ENERGY AND COMBUSTION SCIENCE LA English DT Review ID HIGH-TEMPERATURE REACTIONS; HOMOGENEOUS THERMAL-OXIDATION; RATE-CONSTANT MEASUREMENTS; NON-ARRHENIUS BEHAVIOR; OXYGEN-ARGON MIXTURES; SHOCK-TUBE TECHNIQUE; GAS-PHASE REACTIONS; SENSITIVITY ANALYSIS; HYDROCARBON COMBUSTION; PARAMETER-ESTIMATION AB A method of systematic optimization, solution mapping, as applied to a large-scale dynamic model is presented. The basis of the technique is parameterization of model responses in terms of model parameters by simple algebraic expressions. These expressions are obtained by computer experiments arranged in a factorial design. The developed parametrized responses are then used in a joint multi-parameter multi-data-set optimization. A brief review of the mathematical background of the technique is given. The concept of active parameters is discussed. The technique is applied to determine an optimum set of parameters for a methane combustion mechanism. Five independent responses-comprising ignition delay times, pre-ignition methyl radical concentration profiles, and laminar premixed flame velocities-were optimized with respect to thirteen reaction rate parameters. The numerical predictions of the optimized model are compared to those computed with several recent literature mechanisms. The utility of the solution mapping technique in situations where the optimum is not unique is also demonstrated. C1 NASA,LEWIS RES CTR,DIV INTERNAL FLUID MECH,CLEVELAND,OH 44135. RP FRENKLACH, M (reprint author), PENN STATE UNIV,DEPT MAT SCI & ENGN,FUEL SCI PROGRAM,UNIV PK,PA 16802, USA. RI Wang, Hai/A-1292-2009 OI Wang, Hai/0000-0001-6507-5503 NR 186 TC 216 Z9 218 U1 8 U2 45 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-1285 J9 PROG ENERG COMBUST JI Prog. Energy Combust. Sci. PY 1992 VL 18 IS 1 BP 47 EP 73 DI 10.1016/0360-1285(92)90032-V PG 27 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA GY560 UT WOS:A1992GY56000003 ER PT J AU KENNELLY, EJ YANG, S WALKER, GAH HUBENY, I AF KENNELLY, EJ YANG, S WALKER, GAH HUBENY, I TI DETECTION OF HIGH-DEGREE NONRADIAL PULSATIONS IN GAMMA-BOOTIS SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID LINE-PROFILE VARIATIONS; DELTA-SCUTI STARS; OSCILLATIONS AB The line-profile variations of the rapidly rotating delta-Scuti star gamma-Bootis can be explained by high-degree (\m\ congruent-to 10) nonradial pulsations (NRPs) with an apparent period of DELTA-t congruent-to 0.047 days. This same period was derived from two data sets taken three months apart wherein the amplitude increased by 30%. Such high-degree NRP cannot explain the apparent reversals previously observed by Auvergne et al. for this star in the cores of the hydrogen Balmer lines and Ca II K line. Our radial-velocity variations can be reconciled with their 0.25 day spectroscopic period if an amplitude of approximately 1 km s-1 is adopted, an order of magnitude less than previous measurements. We demonstrate that the presence of line-profile variations from high-degree modes probably limits the accuracy of radial-velocity measurements and may appear as bumps in the radial-velocity curve. C1 UNIV BRITISH COLUMBIA,DEPT GEOPHYS & ASTRON,VANCOUVER V6T 1W5,BC,CANADA. UNIV VICTORIA,DEPT PHYS,VICTORIA V8W 2Y2,BC,CANADA. NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,GREENBELT,MD 20771. NR 18 TC 14 Z9 14 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JAN PY 1992 VL 104 IS 671 BP 15 EP 22 DI 10.1086/132952 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HC834 UT WOS:A1992HC83400002 ER PT J AU HUTCHINGS, JB NEFF, SG GOWER, AC AF HUTCHINGS, JB NEFF, SG GOWER, AC TI THE STRUCTURE OF THE BAL QSO-1700+518 SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID ABSORPTION-LINE QSO; LOW-REDSHIFT; QUASAR AB We present 0.5 arcsec resolution optical images of the low-redshift, bright, broad-absorption-line (BAL) QSO 1700 + 518. We find a bright arc 2 arcsec to the NE of the nucleus which is redder than the surrounding host galaxy. There is also a faint radial structure to the SE, which is aligned with the core radio structure. The principal radio structure is a slightly resolved component coincident with the optical nucleus and an unresolved lobe 1 arcsec to the W which has no corresponding optical structure. We discuss the morphological and other properties of the QSO. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV VICTORIA,DEPT PHYS & ASTRON,VICTORIA V8W 2Y2,BC,CANADA. RP HUTCHINGS, JB (reprint author), NATL RES COUNCIL CANADA,DOMINION ASTROPHYS OBSERV,5071 W SAANICH RD,VICTORIA V8X 4M6,BC,CANADA. NR 12 TC 18 Z9 18 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JAN PY 1992 VL 104 IS 671 BP 62 EP 65 DI 10.1086/132958 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HC834 UT WOS:A1992HC83400008 ER PT J AU HUTCHINGS, JB CRABTREE, D NEFF, SG GOWER, AC AF HUTCHINGS, JB CRABTREE, D NEFF, SG GOWER, AC TI HIGH-RESOLUTION IMAGING OF QSO-2305+187 (=4C 18.68) SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID QUASI-STELLAR OBJECTS; 4C 18.68; OPTICAL CATALOG; QSO AB We present optical imaging of QSO 2305 + 187 with resolution ranging from 0.1 to 1.0 arcsec, in continuum and line emission. The data are from FOCAM and the HR Cam of the Canada-France-Hawaii Telescope, and the Wide Field Camera of the Hubble Space Telescope. These are compared with previously published optical and radio images. The QSO host galaxy has the basic properties of an elliptical, but has significant irregularities, and tidal tails which indicate an ongoing gravitational interaction with a close companion. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. UNIV VICTORIA,DEPT PHYS & ASTRON,VICTORIA V8W 2Y2,BC,CANADA. RP HUTCHINGS, JB (reprint author), NATL RES COUNCIL CANADA,DOMINION ASTROPHYS OBSERV,5071 W SAANICH RD,VICTORIA V8X 4M6,BC,CANADA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JAN PY 1992 VL 104 IS 671 BP 66 EP 70 DI 10.1086/132959 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HC834 UT WOS:A1992HC83400009 ER PT J AU KUNG, EC MIN, W SUSSKIND, J PARK, CK AF KUNG, EC MIN, W SUSSKIND, J PARK, CK TI AN ANALYSIS OF SIMULATED SUMMER BLOCKING EPISODES SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article ID RANGE AB Using the high-resolution 2 x 2.5 degree version of the Goddard Laboratory for Atmospheres general circulation model, experiments were performed for a 46-day summer period from 1 July to 15 August 1979. During the simulation, sea-surface-temperature (s.s.t.) anomalies were updated daily with observed s.s.t.s to provide a realistic surface heating field. A parallel control run used climatology s.s.t.s. in lieu of observed s.s.t.s. Both the s.s.t. updating experiment and control run were able to simulate the persistent blocking patterns in Eurasia and the eastern Pacific during July. However, only the s.s.t. updating experiment was able to generate the realistic blocking episodes in the last 10-day period during the 46-day simulation. Forecast skill was examined in terms of 500 mb anomaly correlation and error kinetic energy. When the blocking patterns develop or become reinforced, a high forecast skill is apparent in nearly half of the northern hemisphere including the area of blocking and its downstream region. Unlike the major winter blockings, which may be treated as the manifestation of wave number one and two, the summer blockings are localized, and have a smaller scale than that of winter blockings. However, summer blockings treated in this study are persistent, and possess a considerable predictability. C1 NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771. RP KUNG, EC (reprint author), UNIV MISSOURI,DEPT ATMOSPHER SCI,COLUMBIA,MO 65211, USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING, BERKS, ENGLAND RG1 7LJ SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JAN PY 1992 VL 118 IS 504 BP 351 EP 363 DI 10.1002/qj.49711850408 PN B PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA HR735 UT WOS:A1992HR73500007 ER PT J AU TOWNSEND, LW CUCINOTTA, FA WILSON, JW AF TOWNSEND, LW CUCINOTTA, FA WILSON, JW TI INTERPLANETARY CREW EXPOSURE ESTIMATES FOR GALACTIC COSMIC-RAYS SO RADIATION RESEARCH LA English DT Article RP TOWNSEND, LW (reprint author), NASA,LANGLEY RES CTR,DIV SPACE SYST,MAIL STOP 493,HAMPTON,VA 23665, USA. NR 16 TC 43 Z9 44 U1 1 U2 4 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD JAN PY 1992 VL 129 IS 1 BP 48 EP 52 DI 10.2307/3577902 PG 5 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA GY320 UT WOS:A1992GY32000006 PM 1728057 ER PT J AU RODRIGUEZ, E KIM, YJ AF RODRIGUEZ, E KIM, YJ TI A UNIFIED PERTURBATION EXPANSION FOR SURFACE SCATTERING SO RADIO SCIENCE LA English DT Article ID RANDOMLY ROUGH SURFACES; WAVES AB Starting with the extinction theorem, we present a perturbation expansion which, to first and second orders, converges over a wider domain than the small perturbation expansion and the momentum transfer expansion. We show that, in the appropriate limits, both of these theories, as well as the two-scale expansion, are recovered. There is no adjustable parameter, such as a spectral split, in the theory. We apply this theory to random rough surfaces and derive analytic expressions for the coherent field and the bistatic cross section. Finally, we present a numerical test of the theory against method of moments results for Gaussian random rough surfaces with a power law spectrum. These results show that the expansion is remarkably accurate over a large range of surface heights and slopes for both horizontal and vertical polarization. RP RODRIGUEZ, E (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 25 TC 38 Z9 38 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD JAN-FEB PY 1992 VL 27 IS 1 BP 79 EP 93 DI 10.1029/91RS02638 PG 15 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA HF796 UT WOS:A1992HF79600008 ER PT J AU CURRAN, PJ DUNGAN, JL GHOLZ, HL AF CURRAN, PJ DUNGAN, JL GHOLZ, HL TI SEASONAL LAI IN SLASH PINE ESTIMATED WITH LANDSAT TM SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID LEAF-AREA-INDEX; TEMPERATE CONIFEROUS FORESTS; ELLIOTTII PLANTATIONS; AVHRR DATA; HRV DATA; VEGETATION; DYNAMICS; SCATTERING; SIMULATION; BIOMASS AB The leaf area index (LAI, total area of leaves per unit area of ground) of most forest canopies varies throughout the year, yet for logistical reasons it is difficult to estimate anything more detailed than an annual average LAI. To determine if remotely sensed data can be used to estimate LAI at times throughout the year (herein termed seasonal LAI), field measurements of LAI were compared to normalized difference vegetation index (NDVI) values, derived using Landsat Thematic Mapper (TM) data, for 16 fertilized and control slash pine plots on three dates. Linear relationships existed between NDVI and LAI with R2 values of 0.35, 0.75, and 0.86 for February 1988, September 1988, and March 1989, respectively. Predictive relationships based on data from eight of the plots were used to estimate the LAI of the other eight plots with a root-mean-square error of 0.74 LAI, which is 15.6% of the mean LAI. This demonstrates the potential use of Landsat TM data for studying seasonal dynamics in forest canopies. C1 UNIV FLORIDA,DEPT FORESTRY,GAINESVILLE,FL 32611. TGS TECHNOL INC,NASA,AMES RES CTR,MOFFETT FIELD,CA. RP CURRAN, PJ (reprint author), UNIV COLL SWANSEA,DEPT GEOG,SINGLETON PK,SWANSEA SA2 8PP,W GLAM,WALES. RI Dungan, Jennifer/G-9921-2016 OI Dungan, Jennifer/0000-0002-4863-1616 NR 38 TC 101 Z9 113 U1 3 U2 14 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JAN PY 1992 VL 39 IS 1 BP 3 EP 13 DI 10.1016/0034-4257(92)90136-8 PG 11 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA HD070 UT WOS:A1992HD07000001 ER PT J AU KNYAZIKHIN, YV MARSHAK, AL MYNENI, RB AF KNYAZIKHIN, YV MARSHAK, AL MYNENI, RB TI INTERACTION OF PHOTONS IN A CANOPY OF FINITE-DIMENSIONAL LEAVES SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID TRANSPORT-EQUATION; PLANT CANOPIES; REFLECTANCE AB The physics of neutral particle interaction for photons traveling in media consisting of finite-dimensional scattering centers that cross-shade mutually is investigated. A leaf canopy is a typical example of such media. The leaf canopy is idealized example of such media. The leaf canopy is idealized as a binary medium consisting of gaps (voids) and regions with phytoelements (turbid phytomedium). Gaps through which photons travel unimpededly are assumed to be randomly distributed. The mathematical approach for characterizing the structure of the host medium is considered in detail. In this approach, the leaf canopy is represented by a combination of all possible open oriented spheres. With rigorous definitions and notations, dependence of the extinction coefficient on the phase-space coordinates of the previous interaction center is shown to be a logical consequence. Specifically, the extinction coefficient at any phase-space location in a leaf canopy is the product of the extinction coefficient in the turbid phytomedium and the probability of absence gaps at that location. Using a similar approach, an expression for the differential scattering coefficient is derived. Numerical results are presented to illustrate the influence of canopy parameters and direction of photon travel on the extinction coefficient. C1 UNIV GOTTINGEN,INST BIOKLIMATOL,BUSGENWEG 1,W-3400 GOTTINGEN,GERMANY. NASA,GODDARD SPACE FLIGHT CTR,HYDROL SCI BRANCH,GREENBELT,MD 20771. RI Marshak, Alexander/D-5671-2012; Myneni, Ranga/F-5129-2012 NR 19 TC 26 Z9 28 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JAN PY 1992 VL 39 IS 1 BP 61 EP 74 DI 10.1016/0034-4257(92)90140-F PG 14 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA HD070 UT WOS:A1992HD07000005 ER PT J AU PARMAR, DS SINGH, JJ EFTEKHARI, A AF PARMAR, DS SINGH, JJ EFTEKHARI, A TI A SHEAR SENSITIVE MONOMER-POLYMER LIQUID-CRYSTAL SYSTEM FOR WIND-TUNNEL APPLICATIONS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID HEAT-TRANSFER MEASUREMENTS; COMPOSITE; ELEMENT AB Characteristics of a liquid crystal system, comprised of a shear sensitive cholesteric monomer liquid crystal thin-film coated on a liquid crystal polymer substrate, are described. The system provides stable Grandjean texture, a desirable feature for shear stress measurements using selective reflection from the monomer liquid crystal helix structure. Impingement of gas or air flow on the monomer liquid crystal free surface changes the wavelength of the selective reflection for an incident white light from red towards blue with increase in the rate of gas flow. The contrast of the selectively reflected light improves considerably by providing a thin (approximately 5-mu-m) black coating at the monomer-polymer interface. The coating thickness is such that the steric interactions are still sufficiently strong to maintain Grandjean texture. For a small angle of incidence (approximately 15-degrees) of a monochromatic light, the measurement of the reflected light intensity normal to the monomer-polymer liquid crystal interface enables us to determine the wavelength (lambda(s)) for selective reflection as a function of the gas flow differential pressure (DELTA-p) applied in the plane of the interface. In the range of the DELTA-p (0-100 mmHg) used in the present studies, the variation of lambda(s) with DELTA-p is linear with a slope approximately 2 nm/mmHg. Furthermore, the shear stress effects are reversible unlike for monomer liquid crystal-metal systems used so far for flow visualization on wind-tunnel model surfaces. Thus the present system offers a suitable method for direct on-line measurement of shear stress field from measurement of lambda(s) for an incident white light. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NR 16 TC 8 Z9 8 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 1992 VL 63 IS 1 BP 225 EP 229 DI 10.1063/1.1142963 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GZ625 UT WOS:A1992GZ62500035 ER PT J AU COOK, JD LONG, KJ HEINEN, VO STANKIEWICZ, N AF COOK, JD LONG, KJ HEINEN, VO STANKIEWICZ, N TI THE INTRODUCTION OF SPURIOUS MODES IN A HOLE-COUPLED FABRY-PEROT OPEN RESONATOR SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A hemispherical open resonator has previously been used to make relative comparisons of the surface resistivity of metallic thin-film samples in the submillimeter wavelength region. This resonator is fed from a far-infrared laser via a small coupling hole in the center of the concave spherical mirror. The experimental arrangement, while desirable as a coupling geometry for monitoring weak emissions from the cavity, can lead to the introduction of spurious modes into the cavity. Sources of these modes are identified, and a simple alteration of the experimental apparatus to eliminate such modes is suggested. C1 NASA,LEWIS RES CTR,DIV SPACE ELECTR,CLEVELAND,OH 44135. RP COOK, JD (reprint author), EASTERN KENTUCKY UNIV,DEPT PHYS & ASTRON,RICHMOND,KY 40475, USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 1992 VL 63 IS 1 BP 267 EP 268 DI 10.1063/1.1142971 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA GZ625 UT WOS:A1992GZ62500043 ER PT J AU GRADY, JE LERCH, BA AF GRADY, JE LERCH, BA TI EFFECT OF HEAT-TREATMENT ON STIFFNESS AND DAMPING OF SIC/TI-15-3 SO SAMPE QUARTERLY-SOCIETY FOR THE ADVANCEMENT OF MATERIAL AND PROCESS ENGINEERING LA English DT Article AB The effect of heat treatment on material properties of Sic\Ti-15-3 was measured by vibration tests. Heat treatment changes the microstructure, which stiffens the matrix and reduces its damping capacity. Test results illustrate how the changes in matrix material affect the stiffness and damping properties of the composite. Damping was found to be more sensitive than stiffness to microstructural changes in the matrix. Effects of heat treatment temperature and exposure time are presented. RP GRADY, JE (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 SN 0036-0821 J9 SAMPE QUART PD JAN PY 1992 VL 23 IS 2 BP 11 EP 16 PG 6 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA HC459 UT WOS:A1992HC45900002 ER EF